client/tailscale, cmd/tailscale/cli: plumb --socket through

Without this, `tailscale status` ignores the --socket flag on macOS and
always talks to the IPNExtension, even if you wanted it to inspect a
userspace tailscaled.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>

.github/workflows/coverage.yml

@@ -0,0 +1,48 @@
+name: Code Coverage
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+
+    steps:
+
+    - name: Set up Go
+      uses: actions/setup-go@v1
+      with:
+        go-version: 1.16
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v1
+
+      # https://markphelps.me/2019/11/speed-up-your-go-builds-with-actions-cache/
+    - name: Restore Cache
+      uses: actions/cache@preview
+      id: cache
+      with:
+        path: ~/go/pkg/mod
+        key: ${{ runner.os }}-${{ hashFiles('**/go.sum') }}
+
+    - name: Basic build
+      run: go build ./cmd/...
+
+    - name: Run tests on linux with coverage data
+      run: go test -race -coverprofile=coverage.txt -bench=. -benchtime=1x ./...
+
+    - name: coveralls.io
+      uses: shogo82148/actions-goveralls@v1
+      env:
+        COVERALLS_TOKEN: ${{ secrets.COVERALLS_TOKEN }}
+        GITHUB_TOKEN: ${{ secrets.COVERALLS_BOT_PUBLIC_REPO_TOKEN }}
+      with:
+        path-to-profile: ./coverage.txt

.github/workflows/cross-darwin.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/cross-freebsd.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/cross-openbsd.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/cross-windows.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/depaware.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
 
     - name: Check out code
       uses: actions/checkout@v1

.github/workflows/license.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
 
     - name: Check out code
       uses: actions/checkout@v1

.github/workflows/linux.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/linux32.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
       id: go
 
     - name: Check out code into the Go module directory

.github/workflows/staticcheck.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
 
     - name: Check out code
       uses: actions/checkout@v1

.github/workflows/windows.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Install Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.15.x
+        go-version: 1.16.x
 
     - name: Checkout code
       uses: actions/checkout@v2

.gitignore

@@ -1,12 +1,11 @@
 # Binaries for programs and plugins
 *~
+*.tmp
 *.exe
 *.dll
 *.so
 *.dylib
 
-cmd/relaynode/relaynode
-cmd/taillogin/taillogin
 cmd/tailscale/tailscale
 cmd/tailscaled/tailscaled
 
@@ -18,3 +17,7 @@ cmd/tailscaled/tailscaled
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
+
+# direnv config, this may be different for other people so it's probably safer
+# to make this nonspecific.
+.envrc

Dockerfile

@@ -2,6 +2,23 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
+############################################################################
+#
+# WARNING: Tailscale is not yet officially supported in Docker,
+# Kubernetes, etc.
+#
+# It might work, but we don't regularly test it, and it's not as polished as
+# our currently supported platforms. This is provided for people who know
+# how Tailscale works and what they're doing.
+#
+# Our tracking bug for officially support container use cases is:
+#    https://github.com/tailscale/tailscale/issues/504
+#
+# Also, see the various bugs tagged "containers":
+#    https://github.com/tailscale/tailscale/labels/containers
+#
+############################################################################
+
 # This Dockerfile includes all the tailscale binaries.
 #
 # To build the Dockerfile:
@@ -21,7 +38,7 @@
 #     $ docker exec tailscaled tailscale status
 
 
-FROM golang:1.14-alpine AS build-env
+FROM golang:1.16-alpine AS build-env
 
 WORKDIR /go/src/tailscale
 
@@ -31,7 +48,19 @@ RUN go mod download
 
 COPY . .
 
-RUN go install -v ./cmd/...
+# see build_docker.sh
+ARG VERSION_LONG=""
+ENV VERSION_LONG=$VERSION_LONG
+ARG VERSION_SHORT=""
+ENV VERSION_SHORT=$VERSION_SHORT
+ARG VERSION_GIT_HASH=""
+ENV VERSION_GIT_HASH=$VERSION_GIT_HASH
+
+RUN go install -tags=xversion -ldflags="\
+      -X tailscale.com/version.Long=$VERSION_LONG \
+      -X tailscale.com/version.Short=$VERSION_SHORT \
+      -X tailscale.com/version.GitCommit=$VERSION_GIT_HASH" \
+      -v ./cmd/...
 
 FROM alpine:3.11
 RUN apk add --no-cache ca-certificates iptables iproute2

LICENSE

@@ -1,27 +1,29 @@
-Copyright (c) 2020 Tailscale & AUTHORS. All rights reserved.
+BSD 3-Clause License
+
+Copyright (c) 2020 Tailscale & AUTHORS.
+All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
+modification, are permitted provided that the following conditions are met:
 
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Tailscale Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
 
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Makefile

@@ -12,7 +12,13 @@ depaware:
 	go run github.com/tailscale/depaware --check tailscale.com/cmd/tailscaled
 	go run github.com/tailscale/depaware --check tailscale.com/cmd/tailscale
 
-check: staticcheck vet depaware
+buildwindows:
+	GOOS=windows GOARCH=amd64 go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
+
+build386:
+	GOOS=linux GOARCH=386 go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
+
+check: staticcheck vet depaware buildwindows build386
 
 staticcheck:
 	go run honnef.co/go/tools/cmd/staticcheck -- $$(go list ./... | grep -v tempfork)

README.md

@@ -43,7 +43,7 @@ If your distro has conventions that preclude the use of
 distro's way, so that bug reports contain useful version information.
 
 We only guarantee to support the latest Go release and any Go beta or
-release candidate builds (currently Go 1.15) in module mode. It might
+release candidate builds (currently Go 1.16) in module mode. It might
 work in earlier Go versions or in GOPATH mode, but we're making no
 effort to keep those working.
 
@@ -63,8 +63,13 @@ Origin](https://en.wikipedia.org/wiki/Developer_Certificate_of_Origin)
 
 ## About Us
 
-We are apenwarr, bradfitz, crawshaw, danderson, dfcarney, josharian
-from Tailscale Inc.
-You can learn more about us from [our website](https://tailscale.com).
+[Tailscale](https://tailscale.com/) is primarily developed by the
+people at https://github.com/orgs/tailscale/people. For other contributors,
+see:
+
+* https://github.com/tailscale/tailscale/graphs/contributors
+* https://github.com/tailscale/tailscale-android/graphs/contributors
+
+## Legal
 
 WireGuard is a registered trademark of Jason A. Donenfeld.

VERSION.txt

@@ -1 +1 @@
-1.1.0 f81233524fddeec450940af8dc1a0dd8841bf28c
+1.7.0

api.md

@@ -0,0 +1,774 @@
+# Tailscale API
+
+The Tailscale API is a (mostly) RESTful API. Typically, POST bodies should be JSON encoded and responses will be JSON encoded.
+
+# Authentication
+Currently based on {some authentication method}. Visit the [admin panel](https://api.tailscale.com/admin) and navigate to the `Keys` page. Generate an API Key and keep it safe. Provide the key as the user key in basic auth when making calls to Tailscale API endpoints.
+
+# APIs
+
+* **[Devices](#device)**
+  - [GET device](#device-get)
+  - [DELETE device](#device-delete)
+  - Routes
+    - [GET device routes](#device-routes-get)
+    - [POST device routes](#device-routes-post)
+* **[Tailnets](#tailnet)**
+  - ACLs
+    - [GET tailnet ACL](#tailnet-acl-get)
+    - [POST tailnet ACL](#tailnet-acl-post): set ACL for a tailnet
+    - [POST tailnet ACL preview](#tailnet-acl-preview-post): preview rule matches on an ACL for a resource
+  - [Devices](#tailnet-devices)
+    - [GET tailnet devices](#tailnet-devices-get)
+  - [DNS](#tailnet-dns)
+    - [GET tailnet DNS nameservers](#tailnet-dns-nameservers-get)
+    - [POST tailnet DNS nameservers](#tailnet-dns-nameservers-post)
+    - [GET tailnet DNS preferences](#tailnet-dns-preferences-get)
+    - [POST tailnet DNS preferences](#tailnet-dns-preferences-post)
+    - [GET tailnet DNS searchpaths](#tailnet-dns-searchpaths-get)
+    - [POST tailnet DNS searchpaths](#tailnet-dns-searchpaths-post)
+
+## Device
+<!-- TODO: description about what devices are -->
+Each Tailscale-connected device has a globally-unique identifier number which we refer as the "deviceID" or sometimes, just "id". 
+You can use the deviceID to specify operations on a specific device, like retrieving its subnet routes.
+
+To find the deviceID of a particular device, you can use the ["GET /devices"](#getdevices) API call and generate a list of devices on your network. 
+Find the device you're looking for and get the "id" field.
+This is your deviceID. 
+
+<a name=device-get></div>
+
+#### `GET /api/v2/device/:deviceid` - lists the details for a device
+Returns the details for the specified device.
+Supply the device of interest in the path using its ID.
+Use the `fields` query parameter to explicitly indicate which fields are returned.
+
+
+##### Parameters
+##### Query Parameters
+`fields` - Controls which fields will be included in the returned response.
+Currently, supported options are: 
+* `all`: returns all fields in the response.
+* `default`: return all fields except:
+  * `enabledRoutes`
+  * `advertisedRoutes`
+  * `clientConnectivity` (which contains the following fields: `mappingVariesByDestIP`, `derp`, `endpoints`, `latency`, and `clientSupports`)
+
+Use commas to separate multiple options.
+If more than one option is indicated, then the union is used.
+For example, for `fields=default,all`, all fields are returned.
+If the `fields` parameter is not provided, then the default option is used.
+
+##### Example 
+```
+GET /api/v2/device/12345
+curl 'https://api.tailscale.com/api/v2/device/12345?fields=all' \
+  -u "tskey-yourapikey123:"
+```
+
+Response
+```
+{
+  "addresses":[
+    "100.105.58.116"
+  ],
+  "id":"12345",
+  "user":"user1@example.com",
+  "name":"user1-device.example.com",
+  "hostname":"User1-Device",
+  "clientVersion":"date.20201107",
+  "updateAvailable":false,
+  "os":"macOS",
+  "created":"2020-11-20T20:56:49Z",
+  "lastSeen":"2020-11-20T16:15:55-05:00",
+  "keyExpiryDisabled":false,
+  "expires":"2021-05-19T20:56:49Z",
+  "authorized":true,
+  "isExternal":false,
+  "machineKey":"mkey:user1-machine-key",
+  "nodeKey":"nodekey:user1-node-key",
+  "blocksIncomingConnections":false,
+  "enabledRoutes":[
+    
+  ],
+  "advertisedRoutes":[
+    
+  ],
+  "clientConnectivity": {
+    "endpoints":[
+      "209.195.87.231:59128",
+      "192.168.0.173:59128"
+    ],
+    "derp":"",
+    "mappingVariesByDestIP":false,
+    "latency":{
+      "Dallas":{
+        "latencyMs":60.463043
+      },
+      "New York City":{
+        "preferred":true,
+        "latencyMs":31.323811
+      },
+      "San Francisco":{
+        "latencyMs":81.313389
+      }
+    },
+    "clientSupports":{
+      "hairPinning":false,
+      "ipv6":false,
+      "pcp":false,
+      "pmp":false,
+      "udp":true,
+      "upnp":false
+    }
+  }
+}
+```
+
+<a name=device-delete></div>
+
+#### `DELETE /api/v2/device/:deviceID` - deletes the device from its tailnet
+Deletes the provided device from its tailnet. 
+The device must belong to the user's tailnet.
+Deleting shared/external devices is not supported.
+Supply the device of interest in the path using its ID.
+
+
+##### Parameters
+No parameters.
+
+##### Example
+```
+DELETE /api/v2/device/12345
+curl -X DELETE 'https://api.tailscale.com/api/v2/device/12345' \
+  -u "tskey-yourapikey123:" -v
+```
+
+Response
+
+If successful, the response should be empty: 
+```
+< HTTP/1.1 200 OK
+...
+* Connection #0 to host left intact
+* Closing connection 0
+```
+
+If the device is not owned by your tailnet: 
+```
+< HTTP/1.1 501 Not Implemented
+...
+{"message":"cannot delete devices outside of your tailnet"}
+```
+
+
+<a name=device-routes-get></div>
+
+#### `GET /api/v2/device/:deviceID/routes` - fetch subnet routes that are advertised and enabled for a device
+
+Retrieves the list of subnet routes that a device is advertising, as well as those that are enabled for it. Enabled routes are not necessarily advertised (e.g. for pre-enabling), and likewise, advertised routes are not necessarily enabled.
+
+##### Parameters
+
+No parameters.
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/device/11055/routes' \
+-u "tskey-yourapikey123:"
+```
+
+Response
+```
+{
+   "advertisedRoutes" : [
+      "10.0.1.0/24",
+      "1.2.0.0/16",
+      "2.0.0.0/24"
+   ],
+   "enabledRoutes" : []
+}
+```
+
+<a name=device-routes-post></div>
+
+#### `POST /api/v2/device/:deviceID/routes` - set the subnet routes that are enabled for a device
+
+Sets which subnet routes are enabled to be routed by a device by replacing the existing list of subnet routes with the supplied parameters. Routes can be enabled without a device advertising them (e.g. for preauth). Returns a list of enabled subnet routes and a list of advertised subnet routes for a device.
+
+##### Parameters
+
+###### POST Body
+`routes` - The new list of enabled subnet routes in JSON.
+```
+{
+  "routes": ["10.0.1.0/24", "1.2.0.0/16", "2.0.0.0/24"]
+}
+```
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/device/11055/routes' \
+-u "tskey-yourapikey123:" \
+--data-binary '{"routes": ["10.0.1.0/24", "1.2.0.0/16", "2.0.0.0/24"]}'
+```
+
+Response
+
+```
+{
+   "advertisedRoutes" : [
+      "10.0.1.0/24",
+      "1.2.0.0/16",
+      "2.0.0.0/24"
+   ],
+   "enabledRoutes" : [
+      "10.0.1.0/24",
+      "1.2.0.0/16",
+      "2.0.0.0/24"
+   ]
+}
+```
+
+## Tailnet 
+A tailnet is the name of your Tailscale network. 
+You can find it in the top left corner of the [Admin Panel](https://login.tailscale.com/admin) beside the Tailscale logo.
+
+
+`alice@example.com` belongs to the `example.com` tailnet and would use the following format for API calls:
+
+```
+GET /api/v2/tailnet/example.com/...
+curl https://api.tailscale.com/api/v2/tailnet/example.com/...
+```
+
+
+For solo plans, the tailnet is the email you signed up with.
+So `alice@gmail.com` has the tailnet `alice@gmail.com` since `@gmail.com` is a shared email host.
+Her API calls would have the following format:
+```
+GET /api/v2/tailnet/alice@gmail.com/...
+curl https://api.tailscale.com/api/v2/tailnet/alice@gmail.com/...
+```
+
+Tailnets are a top-level resource. ACL is an example of a resource that is tied to a top-level tailnet.
+
+For more information on Tailscale networks/tailnets, click [here](https://tailscale.com/kb/1064/invite-team-members).
+
+### ACL
+
+<a name=tailnet-acl-get></a>
+
+#### `GET /api/v2/tailnet/:tailnet/acl` - fetch ACL for a tailnet
+
+Retrieves the ACL that is currently set for the given tailnet. Supply the tailnet of interest in the path. This endpoint can send back either the HuJSON of the ACL or a parsed JSON, depending on the `Accept` header.
+
+##### Parameters
+
+###### Headers
+`Accept` - Response is parsed `JSON` if `application/json` is explicitly named, otherwise HuJSON will be returned.
+
+##### Returns
+Returns the ACL HuJSON by default. Returns a parsed JSON of the ACL (sans comments) if the `Accept` type is explicitly set to `application/json`. An `ETag` header is also sent in the response, which can be optionally used in POST requests to avoid missed updates.
+<!-- TODO (chungdaniel): define error types and a set of docs for them -->
+
+##### Example
+
+###### Requesting a HuJSON response:
+```
+GET /api/v2/tailnet/example.com/acl
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl' \
+  -u "tskey-yourapikey123:" \
+  -H "Accept: application/hujson" \
+  -v
+```
+
+Response
+```
+...
+Content-Type: application/hujson
+Etag: "e0b2816b418b3f266309d94426ac7668ab3c1fa87798785bf82f1085cc2f6d9c"
+...
+
+// Example/default ACLs for unrestricted connections.
+{
+    "Tests": [],
+    // Declare static groups of users beyond those in the identity service.
+    "Groups": {
+        "group:example": [
+            "user1@example.com",
+            "user2@example.com"
+        ],
+    },
+    // Declare convenient hostname aliases to use in place of IP addresses.
+    "Hosts": {
+        "example-host-1": "100.100.100.100",
+    },
+    // Access control lists.
+    "ACLs": [
+        // Match absolutely everything. Comment out this section if you want
+        // to define specific ACL restrictions.
+        {
+            "Action": "accept",
+            "Users": [
+                "*"
+            ],
+            "Ports": [
+                "*:*"
+            ]
+        },
+    ]
+}
+```
+
+###### Requesting a JSON response:
+```
+GET /api/v2/tailnet/example.com/acl
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl' \
+  -u "tskey-yourapikey123:" \
+  -H "Accept: application/json" \
+  -v
+```
+
+Response
+```
+...
+Content-Type: application/json
+Etag: "e0b2816b418b3f266309d94426ac7668ab3c1fa87798785bf82f1085cc2f6d9c"
+...
+{
+   "acls" : [
+      {
+         "action" : "accept",
+         "ports" : [
+            "*:*"
+         ],
+         "users" : [
+            "*"
+         ]
+      }
+   ],
+   "groups" : {
+      "group:example" : [
+         "user1@example.com",
+         "user2@example.com"
+      ]
+   },
+   "hosts" : {
+      "example-host-1" : "100.100.100.100"
+   }
+}
+```
+
+<a name=tailnet-acl-post></a>
+
+#### `POST /api/v2/tailnet/:tailnet/acl` - set ACL for a tailnet
+
+Sets the ACL for the given tailnet. HuJSON and JSON are both accepted inputs. An `If-Match` header can be set to avoid missed updates.
+
+Returns error for invalid ACLs.
+Returns error if using an `If-Match` header and the ETag does not match.
+
+##### Parameters
+
+###### Headers
+`If-Match` - A request header. Set this value to the ETag header provided in an `ACL GET` request to avoid missed updates.
+
+`Accept` - Sets the return type of the updated ACL. Response is parsed `JSON` if `application/json` is explicitly named, otherwise HuJSON will be returned.
+
+###### POST Body
+ACL JSON or HuJSON (see https://tailscale.com/kb/1018/acls)
+
+##### Example
+```
+POST /api/v2/tailnet/example.com/acl
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl' \
+  -u "tskey-yourapikey123:" \
+  -H "If-Match: \"e0b2816b418b3f266309d94426ac7668ab3c1fa87798785bf82f1085cc2f6d9c\""
+  --data-binary '// Example/default ACLs for unrestricted connections.
+{
+  // Declare tests to check functionality of ACL rules. User must be a valid user with registered machines.
+  "Tests": [
+    // {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]},
+  ],
+  // Declare static groups of users beyond those in the identity service.
+  "Groups": {
+    "group:example": [ "user1@example.com", "user2@example.com" ],
+  },
+  // Declare convenient hostname aliases to use in place of IP addresses.
+  "Hosts": {
+    "example-host-1": "100.100.100.100",
+  },
+  // Access control lists.
+  "ACLs": [
+    // Match absolutely everything. Comment out this section if you want
+    // to define specific ACL restrictions.
+    { "Action": "accept", "Users": ["*"], "Ports": ["*:*"] },
+  ]
+}'
+```
+
+Response
+```
+// Example/default ACLs for unrestricted connections.
+{
+  // Declare tests to check functionality of ACL rules. User must be a valid user with registered machines.
+  "Tests": [
+    // {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]},
+  ],
+  // Declare static groups of users beyond those in the identity service.
+  "Groups": {
+    "group:example": [ "user1@example.com", "user2@example.com" ],
+  },
+  // Declare convenient hostname aliases to use in place of IP addresses.
+  "Hosts": {
+    "example-host-1": "100.100.100.100",
+  },
+  // Access control lists.
+  "ACLs": [
+    // Match absolutely everything. Comment out this section if you want
+    // to define specific ACL restrictions.
+    { "Action": "accept", "Users": ["*"], "Ports": ["*:*"] },
+  ]
+}
+```
+
+<a name=tailnet-acl-preview-post></a>
+
+#### `POST /api/v2/tailnet/:tailnet/acl/preview` - preview rule matches on an ACL for a resource
+Determines what rules match for a user on an ACL without saving the ACL to the server.
+
+##### Parameters
+
+###### Query Parameters
+`user` - A user's email. The provided ACL is queried with this user to determine which rules match.
+
+###### POST Body
+ACL JSON or HuJSON (see https://tailscale.com/kb/1018/acls)
+
+##### Example
+```
+POST /api/v2/tailnet/example.com/acl/preiew
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl?user=user1@example.com' \
+  -u "tskey-yourapikey123:" \
+  --data-binary '// Example/default ACLs for unrestricted connections.
+{
+  // Declare tests to check functionality of ACL rules. User must be a valid user with registered machines.
+  "Tests": [
+    // {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]},
+  ],
+  // Declare static groups of users beyond those in the identity service.
+  "Groups": {
+    "group:example": [ "user1@example.com", "user2@example.com" ],
+  },
+  // Declare convenient hostname aliases to use in place of IP addresses.
+  "Hosts": {
+    "example-host-1": "100.100.100.100",
+  },
+  // Access control lists.
+  "ACLs": [
+    // Match absolutely everything. Comment out this section if you want
+    // to define specific ACL restrictions.
+    { "Action": "accept", "Users": ["*"], "Ports": ["*:*"] },
+  ]
+}'
+```
+
+Response
+```
+{"matches":[{"users":["*"],"ports":["*:*"],"lineNumber":19}],"user":"user1@example.com"}
+```
+
+<a name=tailnet-devices></a>
+
+### Devices
+
+<a name=tailnet-devices-get></a>
+
+#### <a name="getdevices"></a> `GET /api/v2/tailnet/:tailnet/devices` - list the devices for a tailnet
+Lists the devices in a tailnet. 
+Supply the tailnet of interest in the path.
+Use the `fields` query parameter to explicitly indicate which fields are returned.
+
+
+##### Parameters
+
+###### Query Parameters
+`fields` - Controls which fields will be included in the returned response.
+Currently, supported options are: 
+* `all`: Returns all fields in the response.
+* `default`: return all fields except:
+  * `enabledRoutes`
+  * `advertisedRoutes`
+  * `clientConnectivity` (which contains the following fields: `mappingVariesByDestIP`, `derp`, `endpoints`, `latency`, and `clientSupports`)
+
+Use commas to separate multiple options.
+If more than one option is indicated, then the union is used.
+For example, for `fields=default,all`, all fields are returned.
+If the `fields` parameter is not provided, then the default option is used.
+
+##### Example
+
+```
+GET /api/v2/tailnet/example.com/devices
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/devices' \
+  -u "tskey-yourapikey123:"
+```
+
+Response 
+```
+{
+  "devices":[
+    {
+      "addresses":[
+        "100.68.203.125"
+      ],
+      "clientVersion":"date.20201107",
+      "os":"macOS",
+      "name":"user1-device.example.com",
+      "created":"2020-11-30T22:20:04Z",
+      "lastSeen":"2020-11-30T17:20:04-05:00",
+      "hostname":"User1-Device",
+      "machineKey":"mkey:user1-node-key",
+      "nodeKey":"nodekey:user1-node-key",
+      "id":"12345",
+      "user":"user1@example.com",
+      "expires":"2021-05-29T22:20:04Z",
+      "keyExpiryDisabled":false,
+      "authorized":false,
+      "isExternal":false,
+      "updateAvailable":false,
+      "blocksIncomingConnections":false,
+    },
+    {
+      "addresses":[
+        "100.111.63.90"
+      ],
+      "clientVersion":"date.20201107",
+      "os":"macOS",
+      "name":"user2-device.example.com",
+      "created":"2020-11-30T22:21:03Z",
+      "lastSeen":"2020-11-30T17:21:03-05:00",
+      "hostname":"User2-Device",
+      "machineKey":"mkey:user2-machine-key",
+      "nodeKey":"nodekey:user2-node-key",
+      "id":"48810",
+      "user":"user2@example.com",
+      "expires":"2021-05-29T22:21:03Z",
+      "keyExpiryDisabled":false,
+      "authorized":false,
+      "isExternal":false,
+      "updateAvailable":false,
+      "blocksIncomingConnections":false,
+    }
+  ]
+}
+```
+
+<a name=tailnet-dns></a>
+
+### DNS
+
+<a name=tailnet-dns-nameservers-get></a>
+
+#### `GET /api/v2/tailnet/:tailnet/dns/nameservers` - list the DNS nameservers for a tailnet
+Lists the DNS nameservers for a tailnet. 
+Supply the tailnet of interest in the path.
+
+##### Parameters
+No parameters.
+
+##### Example 
+
+```
+GET /api/v2/tailnet/example.com/dns/nameservers
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/nameservers' \
+  -u "tskey-yourapikey123:"
+```
+
+Response 
+```
+{
+  "dns": ["8.8.8.8"],
+}
+```
+
+<a name=tailnet-dns-nameservers-post></a>
+
+#### `POST /api/v2/tailnet/:tailnet/dns/nameservers` - replaces the list of DNS nameservers for a tailnet
+Replaces the list of DNS nameservers for the given tailnet with the list supplied by the user. 
+Supply the tailnet of interest in the path.
+Note that changing the list of DNS nameservers may also affect the status of MagicDNS (if MagicDNS is on).
+
+##### Parameters
+###### POST Body
+`dns` - The new list of DNS nameservers in JSON.
+```
+{
+  "dns":["8.8.8.8"]
+}
+```
+
+##### Returns
+Returns the new list of nameservers and the status of MagicDNS. 
+
+If all nameservers have been removed, MagicDNS will be automatically disabled (until explicitly turned back on by the user).
+
+##### Example
+###### Adding DNS nameservers with the MagicDNS on:
+```
+POST /api/v2/tailnet/example.com/dns/nameservers
+curl -X POST 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/nameservers' \
+  -u "tskey-yourapikey123:" \
+  --data-binary '{"dns": ["8.8.8.8"]}'
+```
+
+Response:
+```
+{
+  "dns":["8.8.8.8"],
+  "magicDNS":true,
+}
+```
+
+###### Removing all DNS nameservers with the MagicDNS on:
+```
+POST /api/v2/tailnet/example.com/dns/nameservers
+curl -X POST 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/nameservers' \
+  -u "tskey-yourapikey123:" \
+  --data-binary '{"dns": []}'
+```
+
+Response:
+```
+{
+  "dns":[],
+  "magicDNS": false,
+}
+```
+
+<a name=tailnet-dns-preferences-get></a>
+
+#### `GET /api/v2/tailnet/:tailnet/dns/preferences` - retrieves the DNS preferences for a tailnet
+Retrieves the DNS preferences that are currently set for the given tailnet.
+Supply the tailnet of interest in the path.
+
+##### Parameters
+No parameters. 
+
+##### Example
+```
+GET /api/v2/tailnet/example.com/dns/preferences
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/preferences' \
+  -u "tskey-yourapikey123:" 
+```
+
+Response:
+```
+{
+  "magicDNS":false, 
+}
+```
+
+<a name=tailnet-dns-preferences-post></a>
+
+#### `POST /api/v2/tailnet/:tailnet/dns/preferences` - replaces the DNS preferences for a tailnet 
+Replaces the DNS preferences for a tailnet, specifically, the MagicDNS setting.
+Note that MagicDNS is dependent on DNS servers. 
+
+If there is at least one DNS server, then MagicDNS can be enabled. 
+Otherwise, it returns an error.
+Note that removing all nameservers will turn off MagicDNS. 
+To reenable it, nameservers must be added back, and MagicDNS must be explicitly turned on.
+
+##### Parameters
+###### POST Body
+The DNS preferences in JSON. Currently, MagicDNS is the only setting available.
+`magicDNS` -  Automatically registers DNS names for devices in your tailnet.
+```
+{
+  "magicDNS": true
+}
+```
+
+##### Example
+```
+POST /api/v2/tailnet/example.com/dns/preferences
+curl -X POST 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/preferences' \
+  -u "tskey-yourapikey123:" \
+  --data-binary '{"magicDNS": true}'
+```
+
+
+Response:
+
+If there are no DNS servers, it returns an error message:
+```
+{
+  "message":"need at least one nameserver to enable MagicDNS"
+}
+```
+
+If there are DNS servers: 
+```
+{
+  "magicDNS":true,
+}
+```
+
+<a name=tailnet-dns-searchpaths-get></a>
+
+#### `GET /api/v2/tailnet/:tailnet/dns/searchpaths` - retrieves the search paths for a tailnet 
+Retrieves the list of search paths that is currently set for the given tailnet. 
+Supply the tailnet of interest in the path.
+
+
+##### Parameters
+No parameters.
+
+##### Example
+```
+GET /api/v2/tailnet/example.com/dns/searchpaths
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/searchpaths' \
+  -u "tskey-yourapikey123:" 
+```
+
+Response:
+```
+{
+  "searchPaths": ["user1.example.com"],
+}
+```
+
+<a name=tailnet-dns-searchpaths-post></a>
+
+#### `POST /api/v2/tailnet/:tailnet/dns/searchpaths` - replaces the search paths for a tailnet 
+Replaces the list of searchpaths with the list supplied by the user and returns an error otherwise.
+
+##### Parameters
+
+###### POST Body
+`searchPaths` - A list of searchpaths in JSON.
+```
+{
+  "searchPaths: ["user1.example.com", "user2.example.com"]
+}
+```
+
+##### Example
+```
+POST /api/v2/tailnet/example.com/dns/searchpaths
+curl -X POST 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/searchpaths' \
+  -u "tskey-yourapikey123:" \
+  --data-binary '{"searchPaths": ["user1.example.com", "user2.example.com"]}'
+```
+
+Response:
+```
+{
+  "searchPaths": ["user1.example.com", "user2.example.com"],
+}
+```

build_dist.sh

@@ -9,12 +9,8 @@
 # this script, or executing equivalent commands in your
 # distro-specific build system.
 
-set -euo pipefail
+set -eu
 
-describe=$(./version/describe.sh)
-commit=$(git rev-parse --verify --quiet HEAD)
+eval $(./version/version.sh)
 
-long=$(./version/mkversion.sh long "$describe" "")
-short=$(./version/mkversion.sh short "$describe" "")
-
-exec go build -tags xversion -ldflags "-X tailscale.com/version.Long=${long} -X tailscale.com/version.Short=${short} -X tailscale.com/version.GitCommit=${commit}" "$@"
+exec go build -tags xversion -ldflags "-X tailscale.com/version.Long=${VERSION_LONG} -X tailscale.com/version.Short=${VERSION_SHORT} -X tailscale.com/version.GitCommit=${VERSION_GIT_HASH}" "$@"

build_docker.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env sh
+
+#
+# Runs `go build` with flags configured for docker distribution. All
+# it does differently from `go build` is burn git commit and version
+# information into the binaries inside docker, so that we can track down user
+# issues.
+#
+############################################################################
+#
+# WARNING: Tailscale is not yet officially supported in Docker,
+# Kubernetes, etc.
+#
+# It might work, but we don't regularly test it, and it's not as polished as
+# our currently supported platforms. This is provided for people who know
+# how Tailscale works and what they're doing.
+#
+# Our tracking bug for officially support container use cases is:
+#    https://github.com/tailscale/tailscale/issues/504
+#
+# Also, see the various bugs tagged "containers":
+#    https://github.com/tailscale/tailscale/labels/containers
+#
+############################################################################
+
+set -eu
+
+eval $(./version/version.sh)
+
+docker build \
+  --build-arg VERSION_LONG=$VERSION_LONG \
+  --build-arg VERSION_SHORT=$VERSION_SHORT \
+  --build-arg VERSION_GIT_HASH=$VERSION_GIT_HASH \
+  -t tailscale:tailscale .

client/tailscale/tailscale.go

@@ -0,0 +1,139 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package tailscale contains Tailscale client code.
+package tailscale
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+
+	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/paths"
+	"tailscale.com/safesocket"
+	"tailscale.com/tailcfg"
+)
+
+// TailscaledSocket is the tailscaled Unix socket.
+var TailscaledSocket = paths.DefaultTailscaledSocket()
+
+// tsClient does HTTP requests to the local Tailscale daemon.
+var tsClient = &http.Client{
+	Transport: &http.Transport{
+		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+			if addr != "local-tailscaled.sock:80" {
+				return nil, fmt.Errorf("unexpected URL address %q", addr)
+			}
+			if TailscaledSocket == paths.DefaultTailscaledSocket() {
+				// On macOS, when dialing from non-sandboxed program to sandboxed GUI running
+				// a TCP server on a random port, find the random port. For HTTP connections,
+				// we don't send the token. It gets added in an HTTP Basic-Auth header.
+				if port, _, err := safesocket.LocalTCPPortAndToken(); err == nil {
+					var d net.Dialer
+					return d.DialContext(ctx, "tcp", "localhost:"+strconv.Itoa(port))
+				}
+			}
+			return safesocket.Connect(TailscaledSocket, 41112)
+		},
+	},
+}
+
+// DoLocalRequest makes an HTTP request to the local machine's Tailscale daemon.
+//
+// URLs are of the form http://local-tailscaled.sock/localapi/v0/whois?ip=1.2.3.4.
+//
+// The hostname must be "local-tailscaled.sock", even though it
+// doesn't actually do any DNS lookup. The actual means of connecting to and
+// authenticating to the local Tailscale daemon vary by platform.
+//
+// DoLocalRequest may mutate the request to add Authorization headers.
+func DoLocalRequest(req *http.Request) (*http.Response, error) {
+	if _, token, err := safesocket.LocalTCPPortAndToken(); err == nil {
+		req.SetBasicAuth("", token)
+	}
+	return tsClient.Do(req)
+}
+
+// WhoIs returns the owner of the remoteAddr, which must be an IP or IP:port.
+func WhoIs(ctx context.Context, remoteAddr string) (*tailcfg.WhoIsResponse, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/whois?addr="+url.QueryEscape(remoteAddr), nil)
+	if err != nil {
+		return nil, err
+	}
+	res, err := DoLocalRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+	slurp, _ := ioutil.ReadAll(res.Body)
+	if res.StatusCode != 200 {
+		return nil, fmt.Errorf("HTTP %s: %s", res.Status, slurp)
+	}
+	r := new(tailcfg.WhoIsResponse)
+	if err := json.Unmarshal(slurp, r); err != nil {
+		if max := 200; len(slurp) > max {
+			slurp = slurp[:max]
+		}
+		return nil, fmt.Errorf("failed to parse JSON WhoIsResponse from %q", slurp)
+	}
+	return r, nil
+}
+
+// Goroutines returns a dump of the Tailscale daemon's current goroutines.
+func Goroutines(ctx context.Context) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/goroutines", nil)
+	if err != nil {
+		return nil, err
+	}
+	res, err := DoLocalRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode != 200 {
+		return nil, fmt.Errorf("HTTP %s: %s", res.Status, body)
+	}
+	return body, nil
+}
+
+// Status returns the Tailscale daemon's status.
+func Status(ctx context.Context) (*ipnstate.Status, error) {
+	return status(ctx, "")
+}
+
+// StatusWithPeers returns the Tailscale daemon's status, without the peer info.
+func StatusWithoutPeers(ctx context.Context) (*ipnstate.Status, error) {
+	return status(ctx, "?peers=false")
+}
+
+func status(ctx context.Context, queryString string) (*ipnstate.Status, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/status"+queryString, nil)
+	if err != nil {
+		return nil, err
+	}
+	res, err := DoLocalRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != 200 {
+		body, _ := ioutil.ReadAll(res.Body)
+		return nil, fmt.Errorf("HTTP %s: %s", res.Status, body)
+	}
+	st := new(ipnstate.Status)
+	if err := json.NewDecoder(res.Body).Decode(st); err != nil {
+		return nil, err
+	}
+	return st, nil
+}

cmd/cloner/cloner.go

@@ -140,7 +140,7 @@ func main() {
 		flag.Usage()
 		os.Exit(2)
 	}
-	if err := ioutil.WriteFile(output, out, 0666); err != nil {
+	if err := ioutil.WriteFile(output, out, 0644); err != nil {
 		log.Fatal(err)
 	}
 }

cmd/derper/bootstrap_dns.go

@@ -0,0 +1,69 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"expvar"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+)
+
+var (
+	dnsMu    sync.Mutex
+	dnsCache = map[string][]net.IP{}
+)
+
+var bootstrapDNSRequests = expvar.NewInt("counter_bootstrap_dns_requests")
+
+func refreshBootstrapDNSLoop() {
+	if *bootstrapDNS == "" {
+		return
+	}
+	for {
+		refreshBootstrapDNS()
+		time.Sleep(10 * time.Minute)
+	}
+}
+
+func refreshBootstrapDNS() {
+	if *bootstrapDNS == "" {
+		return
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	names := strings.Split(*bootstrapDNS, ",")
+	var r net.Resolver
+	for _, name := range names {
+		addrs, err := r.LookupIP(ctx, "ip", name)
+		if err != nil {
+			log.Printf("bootstrap DNS lookup %q: %v", name, err)
+			continue
+		}
+		dnsMu.Lock()
+		dnsCache[name] = addrs
+		dnsMu.Unlock()
+	}
+}
+
+func handleBootstrapDNS(w http.ResponseWriter, r *http.Request) {
+	bootstrapDNSRequests.Add(1)
+	dnsMu.Lock()
+	j, err := json.MarshalIndent(dnsCache, "", "\t")
+	dnsMu.Unlock()
+	if err != nil {
+		log.Printf("bootstrap DNS JSON: %v", err)
+		http.Error(w, "JSON marshal error", 500)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(j)
+}

cmd/derper/derper.go

@@ -25,7 +25,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
 	"golang.org/x/crypto/acme/autocert"
 	"tailscale.com/atomicfile"
 	"tailscale.com/derp"
@@ -35,6 +34,7 @@ import (
 	"tailscale.com/net/stun"
 	"tailscale.com/tsweb"
 	"tailscale.com/types/key"
+	"tailscale.com/types/wgkey"
 	"tailscale.com/version"
 )
 
@@ -48,10 +48,11 @@ var (
 	runSTUN       = flag.Bool("stun", false, "also run a STUN server")
 	meshPSKFile   = flag.String("mesh-psk-file", defaultMeshPSKFile(), "if non-empty, path to file containing the mesh pre-shared key file. It should contain some hex string; whitespace is trimmed.")
 	meshWith      = flag.String("mesh-with", "", "optional comma-separated list of hostnames to mesh with; the server's own hostname can be in the list")
+	bootstrapDNS  = flag.String("bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns")
 )
 
 type config struct {
-	PrivateKey wgcfg.PrivateKey
+	PrivateKey wgkey.Private
 }
 
 func loadConfig() config {
@@ -77,8 +78,8 @@ func loadConfig() config {
 	}
 }
 
-func mustNewKey() wgcfg.PrivateKey {
-	key, err := wgcfg.NewPrivateKey()
+func mustNewKey() wgkey.Private {
+	key, err := wgkey.NewPrivate()
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -97,7 +98,7 @@ func writeNewConfig() config {
 	if err != nil {
 		log.Fatal(err)
 	}
-	if err := atomicfile.WriteFile(*configPath, b, 0666); err != nil {
+	if err := atomicfile.WriteFile(*configPath, b, 0600); err != nil {
 		log.Fatal(err)
 	}
 	return cfg
@@ -145,6 +146,8 @@ func main() {
 	// Create our own mux so we don't expose /debug/ stuff to the world.
 	mux := tsweb.NewMux(debugHandler(s))
 	mux.Handle("/derp", derphttp.Handler(s))
+	go refreshBootstrapDNSLoop()
+	mux.HandleFunc("/bootstrap-dns", handleBootstrapDNS)
 	mux.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
 		w.WriteHeader(200)
@@ -153,7 +156,7 @@ func main() {
 <p>
   This is a
   <a href="https://tailscale.com/">Tailscale</a>
-  <a href="https://godoc.org/tailscale.com/derp">DERP</a>
+  <a href="https://pkg.go.dev/tailscale.com/derp">DERP</a>
   server.
 </p>
 `)

cmd/derper/mesh.go

@@ -5,6 +5,7 @@
 package main
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"log"
@@ -40,6 +41,6 @@ func startMeshWithHost(s *derp.Server, host string) error {
 	c.MeshKey = s.MeshKey()
 	add := func(k key.Public) { s.AddPacketForwarder(k, c) }
 	remove := func(k key.Public) { s.RemovePacketForwarder(k, c) }
-	go c.RunWatchConnectionLoop(s.PublicKey(), add, remove)
+	go c.RunWatchConnectionLoop(context.Background(), s.PublicKey(), logf, add, remove)
 	return nil
 }

cmd/hello/hello.go

@@ -0,0 +1,185 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The hello binary runs hello.ipn.dev.
+package main // import "tailscale.com/cmd/hello"
+
+import (
+	"context"
+	_ "embed"
+	"encoding/json"
+	"flag"
+	"html/template"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+
+	"tailscale.com/client/tailscale"
+	"tailscale.com/tailcfg"
+)
+
+var (
+	httpAddr  = flag.String("http", ":80", "address to run an HTTP server on, or empty for none")
+	httpsAddr = flag.String("https", ":443", "address to run an HTTPS server on, or empty for none")
+	testIP    = flag.String("test-ip", "", "if non-empty, look up IP and exit before running a server")
+)
+
+//go:embed hello.tmpl.html
+var embeddedTemplate string
+
+func main() {
+	flag.Parse()
+	if *testIP != "" {
+		res, err := tailscale.WhoIs(context.Background(), *testIP)
+		if err != nil {
+			log.Fatal(err)
+		}
+		e := json.NewEncoder(os.Stdout)
+		e.SetIndent("", "\t")
+		e.Encode(res)
+		return
+	}
+	if devMode() {
+		// Parse it optimistically
+		var err error
+		tmpl, err = template.New("home").Parse(embeddedTemplate)
+		if err != nil {
+			log.Printf("ignoring template error in dev mode: %v", err)
+		}
+	} else {
+		if embeddedTemplate == "" {
+			log.Fatalf("embeddedTemplate is empty; must be build with Go 1.16+")
+		}
+		tmpl = template.Must(template.New("home").Parse(embeddedTemplate))
+	}
+
+	http.HandleFunc("/", root)
+	log.Printf("Starting hello server.")
+
+	errc := make(chan error, 1)
+	if *httpAddr != "" {
+		log.Printf("running HTTP server on %s", *httpAddr)
+		go func() {
+			errc <- http.ListenAndServe(*httpAddr, nil)
+		}()
+	}
+	if *httpsAddr != "" {
+		log.Printf("running HTTPS server on %s", *httpsAddr)
+		go func() {
+			errc <- http.ListenAndServeTLS(*httpsAddr,
+				"/etc/hello/hello.ipn.dev.crt",
+				"/etc/hello/hello.ipn.dev.key",
+				nil,
+			)
+		}()
+	}
+	log.Fatal(<-errc)
+}
+
+func devMode() bool { return *httpsAddr == "" && *httpAddr != "" }
+
+func getTmpl() (*template.Template, error) {
+	if devMode() {
+		tmplData, err := ioutil.ReadFile("hello.tmpl.html")
+		if os.IsNotExist(err) {
+			log.Printf("using baked-in template in dev mode; can't find hello.tmpl.html in current directory")
+			return tmpl, nil
+		}
+		return template.New("home").Parse(string(tmplData))
+	}
+	return tmpl, nil
+}
+
+// tmpl is the template used in prod mode.
+// In dev mode it's only used if the template file doesn't exist on disk.
+// It's initialized by main after flag parsing.
+var tmpl *template.Template
+
+type tmplData struct {
+	DisplayName   string // "Foo Barberson"
+	LoginName     string // "foo@bar.com"
+	ProfilePicURL string // "https://..."
+	MachineName   string // "imac5k"
+	MachineOS     string // "Linux"
+	IP            string // "100.2.3.4"
+}
+
+func tailscaleIP(who *tailcfg.WhoIsResponse) string {
+	if who == nil {
+		return ""
+	}
+	for _, nodeIP := range who.Node.Addresses {
+		if nodeIP.IP.Is4() && nodeIP.IsSingleIP() {
+			return nodeIP.IP.String()
+		}
+	}
+	for _, nodeIP := range who.Node.Addresses {
+		if nodeIP.IsSingleIP() {
+			return nodeIP.IP.String()
+		}
+	}
+	return ""
+}
+
+func root(w http.ResponseWriter, r *http.Request) {
+	if r.TLS == nil && *httpsAddr != "" {
+		host := r.Host
+		if strings.Contains(r.Host, "100.101.102.103") {
+			host = "hello.ipn.dev"
+		}
+		http.Redirect(w, r, "https://"+host, http.StatusFound)
+		return
+	}
+	if r.RequestURI != "/" {
+		http.Redirect(w, r, "/", http.StatusFound)
+		return
+	}
+	tmpl, err := getTmpl()
+	if err != nil {
+		w.Header().Set("Content-Type", "text/plain")
+		http.Error(w, "template error: "+err.Error(), 500)
+		return
+	}
+
+	who, err := tailscale.WhoIs(r.Context(), r.RemoteAddr)
+	var data tmplData
+	if err != nil {
+		if devMode() {
+			log.Printf("warning: using fake data in dev mode due to whois lookup error: %v", err)
+			data = tmplData{
+				DisplayName:   "Taily Scalerson",
+				LoginName:     "taily@scaler.son",
+				ProfilePicURL: "https://placekitten.com/200/200",
+				MachineName:   "scaled",
+				MachineOS:     "Linux",
+				IP:            "100.1.2.3",
+			}
+		} else {
+			log.Printf("whois(%q) error: %v", r.RemoteAddr, err)
+			http.Error(w, "Your Tailscale works, but we failed to look you up.", 500)
+			return
+		}
+	} else {
+		data = tmplData{
+			DisplayName:   who.UserProfile.DisplayName,
+			LoginName:     who.UserProfile.LoginName,
+			ProfilePicURL: who.UserProfile.ProfilePicURL,
+			MachineName:   firstLabel(who.Node.ComputedName),
+			MachineOS:     who.Node.Hostinfo.OS,
+			IP:            tailscaleIP(who),
+		}
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	tmpl.Execute(w, data)
+}
+
+// firstLabel s up until the first period, if any.
+func firstLabel(s string) string {
+	if i := strings.Index(s, "."); i != -1 {
+		return s[:i]
+	}
+	return s
+}

cmd/hello/hello.tmpl.html

@@ -0,0 +1,436 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0">
+  <title>Hello from Tailscale</title>
+  <style>
+    html,
+    body {
+      margin: 0;
+      padding: 0;
+    }
+
+    body {
+      font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+      font-size: 100%;
+      -webkit-font-smoothing: antialiased;
+      -moz-osx-font-smoothing: grayscale;
+    }
+
+    html,
+    body,
+    main {
+      height: 100%;
+    }
+
+    *,
+    ::before,
+    ::after {
+      box-sizing: border-box;
+      border-width: 0;
+      border-style: solid;
+      border-color: #dad6d5;
+    }
+
+    h1,
+    h2,
+    h3,
+    h4,
+    h5,
+    h6 {
+      margin: 0;
+      font-size: 1rem;
+      font-weight: inherit;
+    }
+
+    a {
+      color: inherit;
+    }
+
+    p {
+      margin: 0;
+    }
+
+    main {
+      display: flex;
+      flex-direction: column;
+      justify-content: center;
+      align-items: center;
+      max-width: 24rem;
+      width: 95%;
+      margin-left: auto;
+      margin-right: auto;
+    }
+
+    .p-2 {
+      padding: 0.5rem;
+    }
+
+    .p-4 {
+      padding: 1rem;
+    }
+
+    .px-2 {
+      padding-left: 0.5rem;
+      padding-right: 0.5rem;
+    }
+
+    .pl-3 {
+      padding-left: 0.75rem;
+    }
+
+    .pr-3 {
+      padding-right: 0.75rem;
+    }
+
+    .pt-4 {
+      padding-top: 1rem;
+    }
+
+    .mr-2 {
+      margin-right: 0.5rem;
+      ;
+    }
+
+    .mb-1 {
+      margin-bottom: 0.25rem;
+    }
+
+    .mb-2 {
+      margin-bottom: 0.5rem;
+    }
+
+    .mb-4 {
+      margin-bottom: 1rem;
+    }
+
+    .mb-6 {
+      margin-bottom: 1.5rem;
+    }
+
+    .mb-8 {
+      margin-bottom: 2rem;
+    }
+
+    .mb-12 {
+      margin-bottom: 3rem;
+    }
+
+    .width-full {
+      width: 100%;
+    }
+
+    .min-width-0 {
+      min-width: 0;
+    }
+
+    .rounded-lg {
+      border-radius: 0.5rem;
+    }
+
+    .relative {
+      position: relative;
+    }
+
+    .flex {
+      display: flex;
+    }
+
+    .justify-between {
+      justify-content: space-between;
+    }
+
+    .items-center {
+      align-items: center;
+    }
+
+    .border {
+      border-width: 1px;
+    }
+
+    .border-t-1 {
+      border-top-width: 1px;
+    }
+
+    .border-gray-100 {
+      border-color: #f7f5f4;
+    }
+
+    .border-gray-200 {
+      border-color: #eeebea;
+    }
+
+    .border-gray-300 {
+      border-color: #dad6d5;
+    }
+
+    .bg-white {
+      background-color: white;
+    }
+
+    .bg-gray-0 {
+      background-color: #faf9f8;
+    }
+
+    .bg-gray-100 {
+      background-color: #f7f5f4;
+    }
+
+    .text-green-600 {
+      color: #0d4b3b;
+    }
+
+    .text-blue-600 {
+      color: #3f5db3;
+    }
+
+    .hover\:text-blue-800:hover {
+      color: #253570;
+    }
+
+    .text-gray-600 {
+      color: #444342;
+    }
+
+    .text-gray-700 {
+      color: #2e2d2d;
+    }
+
+    .text-gray-800 {
+      color: #232222;
+    }
+
+    .text-center {
+      text-align: center;
+    }
+
+    .text-sm {
+      font-size: 0.875rem;
+    }
+
+    .font-title {
+      font-size: 1.25rem;
+      letter-spacing: -0.025em;
+    }
+
+    .font-semibold {
+      font-weight: 600;
+    }
+
+    .font-medium {
+      font-weight: 500;
+    }
+
+    .font-regular {
+      font-weight: 400;
+    }
+
+    .truncate {
+      overflow: hidden;
+      text-overflow: ellipsis;
+      white-space: nowrap;
+    }
+
+    .overflow-hidden {
+      overflow: hidden;
+    }
+
+    .profile-pic {
+      width: 2.5rem;
+      height: 2.5rem;
+      border-radius: 9999px;
+      background-size: cover;
+      margin-right: 0.5rem;
+      flex-shrink: 0;
+    }
+
+    .panel {
+      box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
+    }
+
+    .animate .panel {
+      transform: translateY(10%);
+      box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.0), 0 10px 10px -5px rgba(0, 0, 0, 0.0);
+      transition: transform 1200ms ease, opacity 1200ms ease, box-shadow 1200ms ease;
+    }
+
+    .animate .panel-interior {
+      opacity: 0.0;
+      transition: opacity 1200ms ease;
+    }
+
+    .animate .logo {
+      transform: translateY(2rem);
+      opacity: 0.0;
+      transition: transform 1200ms ease, opacity 1200ms ease;
+    }
+
+    .animate .header-title {
+      transform: translateY(1.6rem);
+      opacity: 0.0;
+      transition: transform 1200ms ease, opacity 1200ms ease;
+    }
+
+    .animate .header-text {
+      transform: translateY(1.2rem);
+      opacity: 0.0;
+      transition: transform 1200ms ease, opacity 1200ms ease;
+    }
+
+    .animate .footer {
+      transform: translateY(-0.5rem);
+      opacity: 0.0;
+      transition: transform 1200ms ease, opacity 1200ms ease;
+    }
+
+    .animating .panel {
+      transform: translateY(0);
+      opacity: 1.0;
+      box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
+    }
+
+    .animating .panel-interior {
+      opacity: 1.0;
+    }
+
+    .animating .spinner {
+      opacity: 0.0;
+    }
+
+    .animating .logo,
+    .animating .header-title,
+    .animating .header-text,
+    .animating .footer {
+      transform: translateY(0);
+      opacity: 1.0;
+    }
+
+    .spinner {
+      display: inline-flex;
+      position: absolute;
+      top: 50%;
+      left: 50%;
+      transform: translate(-50%, -50%);
+      align-items: center;
+      transition: opacity 200ms ease;
+    }
+
+    .spinner span {
+      display: inline-block;
+      background-color: currentColor;
+      border-radius: 9999px;
+      animation-name: loading-dots-blink;
+      animation-duration: 1.4s;
+      animation-iteration-count: infinite;
+      animation-fill-mode: both;
+      width: 0.35em;
+      height: 0.35em;
+      margin: 0 0.15em;
+    }
+
+    .spinner span:nth-child(2) {
+      animation-delay: 200ms;
+    }
+
+    .spinner span:nth-child(3) {
+      animation-delay: 400ms;
+    }
+
+    .spinner {
+      display: none;
+    }
+
+    .animate .spinner {
+      display: inline-flex;
+    }
+
+    @keyframes loading-dots-blink {
+      0% {
+        opacity: 0.2;
+      }
+      20% {
+        opacity: 1;
+      }
+      100% {
+        opacity: 0.2;
+      }
+    }
+
+    @media (prefers-reduced-motion) {
+      * {
+        animation-duration: 0ms !important;
+        transition-duration: 0ms !important;
+        transition-delay: 0ms !important;
+      }
+    }
+  </style>
+</head>
+<body class="bg-gray-100">
+  <script>
+    (function() {
+      var lastSeen = localStorage.getItem("lastSeen");
+      if (!lastSeen) {
+        document.body.classList.add("animate");
+        window.addEventListener("load", function () {
+          setTimeout(function () {
+            document.body.classList.add("animating");
+            localStorage.setItem("lastSeen", Date.now());
+          }, 100);
+        });
+      }
+    })();
+  </script>
+  <main class="text-gray-800">
+    <svg class="logo mb-6" width="28" height="28" viewBox="0 0 22 22" fill="none" xmlns="http://www.w3.org/2000/svg">
+      <circle opacity="0.2" cx="3.4" cy="3.25" r="2.7" fill="currentColor" />
+      <circle cx="3.4" cy="11.3" r="2.7" fill="currentColor" />
+      <circle opacity="0.2" cx="3.4" cy="19.5" r="2.7" fill="currentColor" />
+      <circle cx="11.5" cy="11.3" r="2.7" fill="currentColor" />
+      <circle cx="11.5" cy="19.5" r="2.7" fill="currentColor" />
+      <circle opacity="0.2" cx="11.5" cy="3.25" r="2.7" fill="currentColor" />
+      <circle opacity="0.2" cx="19.5" cy="3.25" r="2.7" fill="currentColor" />
+      <circle cx="19.5" cy="11.3" r="2.7" fill="currentColor" />
+      <circle opacity="0.2" cx="19.5" cy="19.5" r="2.7" fill="currentColor" />
+    </svg>
+    <header class="mb-8 text-center">
+      <h1 class="header-title font-title font-semibold mb-2">You're connected over Tailscale!</h1>
+      <p class="header-text">This device is signed in as…</p>
+    </header>
+    <div class="panel relative bg-white rounded-lg width-full shadow-xl mb-8 p-4">
+      <div class="spinner text-gray-600">
+        <span></span>
+        <span></span>
+        <span></span>
+      </div>
+      <div class="panel-interior flex items-center width-full min-width-0 p-2 mb-4">
+        <div class="profile-pic bg-gray-100" style="background-image: url({{.ProfilePicURL}});"></div>
+        <div class="overflow-hidden">
+          {{ with .DisplayName }}
+          <h4 class="font-semibold truncate">{{.}}</h4>
+          {{ end }}
+          <h5 class="text-gray-600 truncate">{{.LoginName}}</h5>
+        </div>
+      </div>
+      <div
+        class="panel-interior border border-gray-200 bg-gray-0 rounded-lg p-2 pl-3 pr-3 mb-2 width-full flex justify-between items-center">
+        <div class="flex items-center min-width-0">
+          <svg class="text-gray-600 mr-2" xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none"
+            stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <rect x="2" y="2" width="20" height="8" rx="2" ry="2"></rect>
+            <rect x="2" y="14" width="20" height="8" rx="2" ry="2"></rect>
+            <line x1="6" y1="6" x2="6.01" y2="6"></line>
+            <line x1="6" y1="18" x2="6.01" y2="18"></line>
+          </svg>
+          <h4 class="font-semibold truncate mr-2">{{.MachineName}}</h4>
+        </div>
+        <h5>{{.IP}}</h5>
+      </div>
+    </div>
+    <footer class="footer text-gray-600 text-center mb-12">
+      <p>Read about <a href="https://tailscale.com/kb/1017/install#advanced-features" class="text-blue-600 hover:text-blue-800"
+          target="_blank">what you can do next &rarr;</a></p>
+    </footer>
+  </main>
+</body>
+</html>

cmd/tailscale/cli/cli.go

@@ -9,6 +9,7 @@ package cli
 import (
 	"context"
 	"flag"
+	"fmt"
 	"log"
 	"net"
 	"os"
@@ -16,8 +17,10 @@ import (
 	"runtime"
 	"strings"
 	"syscall"
+	"text/tabwriter"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
+	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 	"tailscale.com/paths"
 	"tailscale.com/safesocket"
@@ -50,9 +53,11 @@ func Run(args []string) error {
 
 	rootCmd := &ffcli.Command{
 		Name:       "tailscale",
-		ShortUsage: "tailscale subcommand [flags]",
+		ShortUsage: "tailscale [flags] <subcommand> [command flags]",
 		ShortHelp:  "The easiest, most secure way to use WireGuard.",
 		LongHelp: strings.TrimSpace(`
+For help on subcommands, add --help after: "tailscale status --help".
+
 This CLI is still under active development. Commands and flags will
 change in the future.
 `),
@@ -60,12 +65,19 @@ change in the future.
 			upCmd,
 			downCmd,
 			netcheckCmd,
+			ipCmd,
 			statusCmd,
 			pingCmd,
 			versionCmd,
+			webCmd,
+			pushCmd,
 		},
-		FlagSet: rootfs,
-		Exec:    func(context.Context, []string) error { return flag.ErrHelp },
+		FlagSet:   rootfs,
+		Exec:      func(context.Context, []string) error { return flag.ErrHelp },
+		UsageFunc: usageFunc,
+	}
+	for _, c := range rootCmd.Subcommands {
+		c.UsageFunc = usageFunc
 	}
 
 	// Don't advertise the debug command, but it exists.
@@ -77,6 +89,8 @@ change in the future.
 		return err
 	}
 
+	tailscale.TailscaledSocket = rootArgs.socket
+
 	err := rootCmd.Run(context.Background())
 	if err == flag.ErrHelp {
 		return nil
@@ -99,7 +113,7 @@ func connect(ctx context.Context) (net.Conn, *ipn.BackendClient, context.Context
 		if runtime.GOOS != "windows" && rootArgs.socket == "" {
 			fatalf("--socket cannot be empty")
 		}
-		fatalf("Failed to connect to connect to tailscaled. (safesocket.Connect: %v)\n", err)
+		fatalf("Failed to connect to tailscaled. (safesocket.Connect: %v)\n", err)
 	}
 	clientToServer := func(b []byte) {
 		ipn.WriteMsg(c, b)
@@ -143,3 +157,72 @@ func strSliceContains(ss []string, s string) bool {
 	}
 	return false
 }
+
+func usageFunc(c *ffcli.Command) string {
+	var b strings.Builder
+
+	fmt.Fprintf(&b, "USAGE\n")
+	if c.ShortUsage != "" {
+		fmt.Fprintf(&b, "  %s\n", c.ShortUsage)
+	} else {
+		fmt.Fprintf(&b, "  %s\n", c.Name)
+	}
+	fmt.Fprintf(&b, "\n")
+
+	if c.LongHelp != "" {
+		fmt.Fprintf(&b, "%s\n\n", c.LongHelp)
+	}
+
+	if len(c.Subcommands) > 0 {
+		fmt.Fprintf(&b, "SUBCOMMANDS\n")
+		tw := tabwriter.NewWriter(&b, 0, 2, 2, ' ', 0)
+		for _, subcommand := range c.Subcommands {
+			fmt.Fprintf(tw, "  %s\t%s\n", subcommand.Name, subcommand.ShortHelp)
+		}
+		tw.Flush()
+		fmt.Fprintf(&b, "\n")
+	}
+
+	if countFlags(c.FlagSet) > 0 {
+		fmt.Fprintf(&b, "FLAGS\n")
+		tw := tabwriter.NewWriter(&b, 0, 2, 2, ' ', 0)
+		c.FlagSet.VisitAll(func(f *flag.Flag) {
+			var s string
+			name, usage := flag.UnquoteUsage(f)
+			if isBoolFlag(f) {
+				s = fmt.Sprintf("  --%s, --%s=false", f.Name, f.Name)
+			} else {
+				s = fmt.Sprintf("  --%s", f.Name) // Two spaces before --; see next two comments.
+				if len(name) > 0 {
+					s += " " + name
+				}
+			}
+			// Four spaces before the tab triggers good alignment
+			// for both 4- and 8-space tab stops.
+			s += "\n    \t"
+			s += strings.ReplaceAll(usage, "\n", "\n    \t")
+
+			if f.DefValue != "" {
+				s += fmt.Sprintf(" (default %s)", f.DefValue)
+			}
+
+			fmt.Fprintln(&b, s)
+		})
+		tw.Flush()
+		fmt.Fprintf(&b, "\n")
+	}
+
+	return strings.TrimSpace(b.String())
+}
+
+func isBoolFlag(f *flag.Flag) bool {
+	bf, ok := f.Value.(interface {
+		IsBoolFlag() bool
+	})
+	return ok && bf.IsBoolFlag()
+}
+
+func countFlags(fs *flag.FlagSet) (n int) {
+	fs.VisitAll(func(*flag.Flag) { n++ })
+	return n
+}

cmd/tailscale/cli/debug.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
@@ -6,26 +6,12 @@ package cli
 
 import (
 	"context"
-	"crypto/tls"
-	"encoding/json"
 	"errors"
 	"flag"
-	"fmt"
-	"log"
-	"net/http"
-	"net/http/httptrace"
-	"net/url"
 	"os"
-	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/derp/derphttp"
-	"tailscale.com/derp/derpmap"
-	"tailscale.com/net/interfaces"
-	"tailscale.com/net/tshttpproxy"
-	"tailscale.com/tailcfg"
-	"tailscale.com/types/key"
-	"tailscale.com/wgengine/monitor"
+	"tailscale.com/client/tailscale"
 )
 
 var debugCmd = &ffcli.Command{
@@ -33,143 +19,25 @@ var debugCmd = &ffcli.Command{
 	Exec: runDebug,
 	FlagSet: (func() *flag.FlagSet {
 		fs := flag.NewFlagSet("debug", flag.ExitOnError)
-		fs.BoolVar(&debugArgs.monitor, "monitor", false, "If true, run link monitor forever. Precludes all other options.")
-		fs.StringVar(&debugArgs.getURL, "get-url", "", "If non-empty, fetch provided URL.")
-		fs.StringVar(&debugArgs.derpCheck, "derp", "", "if non-empty, test a DERP ping via named region code")
+		fs.BoolVar(&debugArgs.goroutines, "daemon-goroutines", false, "If true, dump the tailscaled daemon's goroutines")
 		return fs
 	})(),
 }
 
 var debugArgs struct {
-	monitor   bool
-	getURL    string
-	derpCheck string
+	goroutines bool
 }
 
 func runDebug(ctx context.Context, args []string) error {
 	if len(args) > 0 {
 		return errors.New("unknown arguments")
 	}
-	if debugArgs.derpCheck != "" {
-		return checkDerp(ctx, debugArgs.derpCheck)
-	}
-	if debugArgs.monitor {
-		return runMonitor(ctx)
-	}
-	if debugArgs.getURL != "" {
-		return getURL(ctx, debugArgs.getURL)
-	}
-	return errors.New("only --monitor is available at the moment")
-}
-
-func runMonitor(ctx context.Context) error {
-	dump := func() {
-		st, err := interfaces.GetState()
+	if debugArgs.goroutines {
+		goroutines, err := tailscale.Goroutines(ctx)
 		if err != nil {
-			log.Printf("error getting state: %v", err)
-			return
+			return err
 		}
-		j, _ := json.MarshalIndent(st, "", "    ")
-		os.Stderr.Write(j)
+		os.Stdout.Write(goroutines)
 	}
-	mon, err := monitor.New(log.Printf, func() {
-		log.Printf("Link monitor fired. State:")
-		dump()
-	})
-	if err != nil {
-		return err
-	}
-	log.Printf("Starting link change monitor; initial state:")
-	dump()
-	mon.Start()
-	log.Printf("Started link change monitor; waiting...")
-	select {}
-}
-
-func getURL(ctx context.Context, urlStr string) error {
-	if urlStr == "login" {
-		urlStr = "https://login.tailscale.com"
-	}
-	log.SetOutput(os.Stdout)
-	ctx = httptrace.WithClientTrace(ctx, &httptrace.ClientTrace{
-		GetConn:           func(hostPort string) { log.Printf("GetConn(%q)", hostPort) },
-		GotConn:           func(info httptrace.GotConnInfo) { log.Printf("GotConn: %+v", info) },
-		DNSStart:          func(info httptrace.DNSStartInfo) { log.Printf("DNSStart: %+v", info) },
-		DNSDone:           func(info httptrace.DNSDoneInfo) { log.Printf("DNSDoneInfo: %+v", info) },
-		TLSHandshakeStart: func() { log.Printf("TLSHandshakeStart") },
-		TLSHandshakeDone:  func(cs tls.ConnectionState, err error) { log.Printf("TLSHandshakeDone: %+v, %v", cs, err) },
-		WroteRequest:      func(info httptrace.WroteRequestInfo) { log.Printf("WroteRequest: %+v", info) },
-	})
-	req, err := http.NewRequestWithContext(ctx, "GET", urlStr, nil)
-	if err != nil {
-		return fmt.Errorf("http.NewRequestWithContext: %v", err)
-	}
-	proxyURL, err := tshttpproxy.ProxyFromEnvironment(req)
-	if err != nil {
-		return fmt.Errorf("tshttpproxy.ProxyFromEnvironment: %v", err)
-	}
-	log.Printf("proxy: %v", proxyURL)
-	tr := &http.Transport{
-		Proxy:              func(*http.Request) (*url.URL, error) { return proxyURL, nil },
-		ProxyConnectHeader: http.Header{},
-		DisableKeepAlives:  true,
-	}
-	if proxyURL != nil {
-		auth, err := tshttpproxy.GetAuthHeader(proxyURL)
-		if err == nil && auth != "" {
-			tr.ProxyConnectHeader.Set("Proxy-Authorization", auth)
-		}
-		const truncLen = 20
-		if len(auth) > truncLen {
-			auth = fmt.Sprintf("%s...(%d total bytes)", auth[:truncLen], len(auth))
-		}
-		log.Printf("tshttpproxy.GetAuthHeader(%v) for Proxy-Auth: = %q, %v", proxyURL, auth, err)
-	}
-	res, err := tr.RoundTrip(req)
-	if err != nil {
-		return fmt.Errorf("Transport.RoundTrip: %v", err)
-	}
-	defer res.Body.Close()
-	return res.Write(os.Stdout)
-}
-
-func checkDerp(ctx context.Context, derpRegion string) error {
-	dmap := derpmap.Prod()
-	getRegion := func() *tailcfg.DERPRegion {
-		for _, r := range dmap.Regions {
-			if r.RegionCode == derpRegion {
-				return r
-			}
-		}
-		for _, r := range dmap.Regions {
-			log.Printf("Known region: %q", r.RegionCode)
-		}
-		log.Fatalf("unknown region %q", derpRegion)
-		panic("unreachable")
-	}
-
-	priv1 := key.NewPrivate()
-	priv2 := key.NewPrivate()
-
-	c1 := derphttp.NewRegionClient(priv1, log.Printf, getRegion)
-	c2 := derphttp.NewRegionClient(priv2, log.Printf, getRegion)
-
-	c2.NotePreferred(true) // just to open it
-
-	m, err := c2.Recv()
-	log.Printf("c2 got %T, %v", m, err)
-
-	t0 := time.Now()
-	if err := c1.Send(priv2.Public(), []byte("hello")); err != nil {
-		return err
-	}
-	fmt.Println(time.Since(t0))
-
-	m, err = c2.Recv()
-	log.Printf("c2 got %T, %v", m, err)
-	if err != nil {
-		return err
-	}
-	log.Printf("ok")
-	return err
+	return nil
 }

cmd/tailscale/cli/down.go

@@ -6,10 +6,12 @@ package cli
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
+	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 )
 
@@ -26,6 +28,16 @@ func runDown(ctx context.Context, args []string) error {
 		log.Fatalf("too many non-flag arguments: %q", args)
 	}
 
+	st, err := tailscale.Status(ctx)
+	if err != nil {
+		return fmt.Errorf("error fetching current status: %w", err)
+	}
+	if st.BackendState == "Stopped" {
+		log.Printf("already stopped")
+		return nil
+	}
+	log.Printf("was in state %q", st.BackendState)
+
 	c, bc, ctx, cancel := connect(ctx)
 	defer cancel()
 
@@ -38,17 +50,6 @@ func runDown(ctx context.Context, args []string) error {
 		if n.ErrMessage != nil {
 			log.Fatal(*n.ErrMessage)
 		}
-		if n.Status != nil {
-			cur := n.Status.BackendState
-			switch cur {
-			case "Stopped":
-				log.Printf("already stopped")
-				cancel()
-			default:
-				log.Printf("was in state %q", cur)
-			}
-			return
-		}
 		if n.State != nil {
 			log.Printf("now in state %q", *n.State)
 			if *n.State == ipn.Stopped {
@@ -58,7 +59,6 @@ func runDown(ctx context.Context, args []string) error {
 		}
 	})
 
-	bc.RequestStatus()
 	bc.SetWantRunning(false)
 	pump(ctx, bc, c)
 

cmd/tailscale/cli/ip.go

@@ -0,0 +1,69 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+
+	"github.com/peterbourgon/ff/v2/ffcli"
+	"tailscale.com/client/tailscale"
+)
+
+var ipCmd = &ffcli.Command{
+	Name:       "ip",
+	ShortUsage: "ip [-4] [-6]",
+	ShortHelp:  "Show this machine's current Tailscale IP address(es)",
+	Exec:       runIP,
+	FlagSet: (func() *flag.FlagSet {
+		fs := flag.NewFlagSet("ip", flag.ExitOnError)
+		fs.BoolVar(&ipArgs.want4, "4", false, "only print IPv4 address")
+		fs.BoolVar(&ipArgs.want6, "6", false, "only print IPv6 address")
+		return fs
+	})(),
+}
+
+var ipArgs struct {
+	want4 bool
+	want6 bool
+}
+
+func runIP(ctx context.Context, args []string) error {
+	if len(args) > 0 {
+		return errors.New("unknown arguments")
+	}
+	v4, v6 := ipArgs.want4, ipArgs.want6
+	if v4 && v6 {
+		return errors.New("tailscale up -4 and -6 are mutually exclusive")
+	}
+	if !v4 && !v6 {
+		v4, v6 = true, true
+	}
+	st, err := tailscale.Status(ctx)
+	if err != nil {
+		return err
+	}
+	if len(st.TailscaleIPs) == 0 {
+		return fmt.Errorf("no current Tailscale IPs; state: %v", st.BackendState)
+	}
+	match := false
+	for _, ip := range st.TailscaleIPs {
+		if ip.Is4() && v4 || ip.Is6() && v6 {
+			match = true
+			fmt.Println(ip)
+		}
+	}
+	if !match {
+		if ipArgs.want4 {
+			return errors.New("no Tailscale IPv4 address")
+		}
+		if ipArgs.want6 {
+			return errors.New("no Tailscale IPv6 address")
+		}
+	}
+	return nil
+}

cmd/tailscale/cli/netcheck.go

@@ -17,8 +17,8 @@ import (
 
 	"github.com/peterbourgon/ff/v2/ffcli"
 	"tailscale.com/derp/derpmap"
-	"tailscale.com/net/dnscache"
 	"tailscale.com/net/netcheck"
+	"tailscale.com/net/portmapper"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
 )
@@ -45,7 +45,8 @@ var netcheckArgs struct {
 
 func runNetcheck(ctx context.Context, args []string) error {
 	c := &netcheck.Client{
-		DNSCache: dnscache.Get(),
+		UDPBindAddr: os.Getenv("TS_DEBUG_NETCHECK_UDP_BIND"),
+		PortMapper:  portmapper.NewClient(logger.WithPrefix(log.Printf, "portmap: ")),
 	}
 	if netcheckArgs.verbose {
 		c.Logf = logger.WithPrefix(log.Printf, "netcheck: ")

cmd/tailscale/cli/ping.go

@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
+	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
 )
@@ -47,6 +48,7 @@ relay node.
 		fs := flag.NewFlagSet("ping", flag.ExitOnError)
 		fs.BoolVar(&pingArgs.verbose, "verbose", false, "verbose output")
 		fs.BoolVar(&pingArgs.untilDirect, "until-direct", true, "stop once a direct path is established")
+		fs.BoolVar(&pingArgs.tsmp, "tsmp", false, "do a TSMP-level ping (through IP + wireguard, but not involving host OS stack)")
 		fs.IntVar(&pingArgs.num, "c", 10, "max number of pings to send")
 		fs.DurationVar(&pingArgs.timeout, "timeout", 5*time.Second, "timeout before giving up on a ping")
 		return fs
@@ -57,6 +59,7 @@ var pingArgs struct {
 	num         int
 	untilDirect bool
 	verbose     bool
+	tsmp        bool
 	timeout     time.Duration
 }
 
@@ -64,44 +67,41 @@ func runPing(ctx context.Context, args []string) error {
 	c, bc, ctx, cancel := connect(ctx)
 	defer cancel()
 
-	if len(args) != 1 {
+	if len(args) != 1 || args[0] == "" {
 		return errors.New("usage: ping <hostname-or-IP>")
 	}
-	hostOrIP := args[0]
 	var ip string
-	var res net.Resolver
-	if addrs, err := res.LookupHost(ctx, hostOrIP); err != nil {
-		return fmt.Errorf("error looking up IP of %q: %v", hostOrIP, err)
-	} else if len(addrs) == 0 {
-		return fmt.Errorf("no IPs found for %q", hostOrIP)
-	} else {
-		ip = addrs[0]
-	}
-	if pingArgs.verbose && ip != hostOrIP {
-		log.Printf("lookup %q => %q", hostOrIP, ip)
-	}
-
-	ch := make(chan *ipnstate.PingResult, 1)
+	prc := make(chan *ipnstate.PingResult, 1)
 	bc.SetNotifyCallback(func(n ipn.Notify) {
 		if n.ErrMessage != nil {
 			log.Fatal(*n.ErrMessage)
 		}
 		if pr := n.PingResult; pr != nil && pr.IP == ip {
-			ch <- pr
+			prc <- pr
 		}
 	})
 	go pump(ctx, bc, c)
 
+	hostOrIP := args[0]
+	ip, err := tailscaleIPFromArg(ctx, hostOrIP)
+	if err != nil {
+		return err
+	}
+
+	if pingArgs.verbose && ip != hostOrIP {
+		log.Printf("lookup %q => %q", hostOrIP, ip)
+	}
+
 	n := 0
 	anyPong := false
 	for {
 		n++
-		bc.Ping(ip)
+		bc.Ping(ip, pingArgs.tsmp)
 		timer := time.NewTimer(pingArgs.timeout)
 		select {
 		case <-timer.C:
 			fmt.Printf("timeout waiting for ping reply\n")
-		case pr := <-ch:
+		case pr := <-prc:
 			timer.Stop()
 			if pr.Err != "" {
 				return errors.New(pr.Err)
@@ -111,8 +111,20 @@ func runPing(ctx context.Context, args []string) error {
 			if pr.DERPRegionID != 0 {
 				via = fmt.Sprintf("DERP(%s)", pr.DERPRegionCode)
 			}
+			if pingArgs.tsmp {
+				// TODO(bradfitz): populate the rest of ipnstate.PingResult for TSMP queries?
+				// For now just say it came via TSMP.
+				via = "TSMP"
+			}
 			anyPong = true
-			fmt.Printf("pong from %s (%s) via %v in %v\n", pr.NodeName, pr.NodeIP, via, latency)
+			extra := ""
+			if pr.PeerAPIPort != 0 {
+				extra = fmt.Sprintf(", %d", pr.PeerAPIPort)
+			}
+			fmt.Printf("pong from %s (%s%s) via %v in %v\n", pr.NodeName, pr.NodeIP, extra, via, latency)
+			if pingArgs.tsmp {
+				return nil
+			}
 			if pr.Endpoint != "" && pingArgs.untilDirect {
 				return nil
 			}
@@ -128,3 +140,31 @@ func runPing(ctx context.Context, args []string) error {
 		}
 	}
 }
+
+func tailscaleIPFromArg(ctx context.Context, hostOrIP string) (ip string, err error) {
+	// If the argument is an IP address, use it directly without any resolution.
+	if net.ParseIP(hostOrIP) != nil {
+		return hostOrIP, nil
+	}
+
+	// Otherwise, try to resolve it first from the network peer list.
+	st, err := tailscale.Status(ctx)
+	if err != nil {
+		return "", err
+	}
+	for _, ps := range st.Peer {
+		if hostOrIP == dnsOrQuoteHostname(st, ps) || hostOrIP == ps.DNSName {
+			return ps.TailAddr, nil
+		}
+	}
+
+	// Finally, use DNS.
+	var res net.Resolver
+	if addrs, err := res.LookupHost(ctx, hostOrIP); err != nil {
+		return "", fmt.Errorf("error looking up IP of %q: %v", hostOrIP, err)
+	} else if len(addrs) == 0 {
+		return "", fmt.Errorf("no IPs found for %q", hostOrIP)
+	} else {
+		return addrs[0], nil
+	}
+}

cmd/tailscale/cli/push.go

@@ -0,0 +1,173 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"mime"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"time"
+	"unicode/utf8"
+
+	"github.com/peterbourgon/ff/v2/ffcli"
+	"tailscale.com/ipn"
+	"tailscale.com/ipn/ipnstate"
+)
+
+var pushCmd = &ffcli.Command{
+	Name:       "push",
+	ShortUsage: "push [--flags] <hostname-or-IP> <file>",
+	ShortHelp:  "Push a file to a host",
+	Exec:       runPush,
+	FlagSet: (func() *flag.FlagSet {
+		fs := flag.NewFlagSet("push", flag.ExitOnError)
+		fs.StringVar(&pushArgs.name, "name", "", "alternate filename to use, especially useful when <file> is \"-\" (stdin)")
+		fs.BoolVar(&pushArgs.verbose, "verbose", false, "verbose output")
+		return fs
+	})(),
+}
+
+var pushArgs struct {
+	name    string
+	verbose bool
+}
+
+func runPush(ctx context.Context, args []string) error {
+	if len(args) != 2 || args[0] == "" {
+		return errors.New("usage: push <hostname-or-IP> <file>")
+	}
+	var ip string
+
+	hostOrIP, fileArg := args[0], args[1]
+	ip, err := tailscaleIPFromArg(ctx, hostOrIP)
+	if err != nil {
+		return err
+	}
+
+	peerAPIPort, err := discoverPeerAPIPort(ctx, ip)
+	if err != nil {
+		return err
+	}
+
+	var fileContents io.Reader
+	var name = pushArgs.name
+	if fileArg == "-" {
+		fileContents = os.Stdin
+		if name == "" {
+			name, fileContents, err = pickStdinFilename()
+			if err != nil {
+				return err
+			}
+		}
+	} else {
+		f, err := os.Open(fileArg)
+		if err != nil {
+			return err
+		}
+		defer f.Close()
+		fileContents = f
+		if name == "" {
+			name = fileArg
+		}
+	}
+
+	dstURL := "http://" + net.JoinHostPort(ip, fmt.Sprint(peerAPIPort)) + "/v0/put/" + url.PathEscape(name)
+	req, err := http.NewRequestWithContext(ctx, "PUT", dstURL, fileContents)
+	if err != nil {
+		return err
+	}
+	if pushArgs.verbose {
+		log.Printf("sending to %v ...", dstURL)
+	}
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	if res.StatusCode == 200 {
+		return nil
+	}
+	io.Copy(os.Stdout, res.Body)
+	return errors.New(res.Status)
+}
+
+func discoverPeerAPIPort(ctx context.Context, ip string) (port uint16, err error) {
+	c, bc, ctx, cancel := connect(ctx)
+	defer cancel()
+
+	prc := make(chan *ipnstate.PingResult, 2)
+	bc.SetNotifyCallback(func(n ipn.Notify) {
+		if n.ErrMessage != nil {
+			log.Fatal(*n.ErrMessage)
+		}
+		if pr := n.PingResult; pr != nil && pr.IP == ip {
+			prc <- pr
+		}
+	})
+	go pump(ctx, bc, c)
+
+	ticker := time.NewTicker(time.Second)
+	defer ticker.Stop()
+
+	discoPings := 0
+	timer := time.NewTimer(10 * time.Second)
+	defer timer.Stop()
+
+	sendPings := func() {
+		bc.Ping(ip, false)
+		bc.Ping(ip, true)
+	}
+	sendPings()
+	for {
+		select {
+		case <-ticker.C:
+			sendPings()
+		case <-timer.C:
+			return 0, fmt.Errorf("timeout contacting %v; it offline?", ip)
+		case pr := <-prc:
+			if p := pr.PeerAPIPort; p != 0 {
+				return p, nil
+			}
+			discoPings++
+			if discoPings == 3 {
+				return 0, fmt.Errorf("%v is online, but seems to be running an old Tailscale version", ip)
+			}
+		case <-ctx.Done():
+			return 0, ctx.Err()
+		}
+	}
+}
+
+const maxSniff = 4 << 20
+
+func ext(b []byte) string {
+	if len(b) < maxSniff && utf8.Valid(b) {
+		return ".txt"
+	}
+	if exts, _ := mime.ExtensionsByType(http.DetectContentType(b)); len(exts) > 0 {
+		return exts[0]
+	}
+	return ""
+}
+
+// pickStdinFilename reads a bit of stdin to return a good filename
+// for its contents. The returned Reader is the concatenation of the
+// read and unread bits.
+func pickStdinFilename() (name string, r io.Reader, err error) {
+	sniff, err := io.ReadAll(io.LimitReader(os.Stdin, maxSniff))
+	if err != nil {
+		return "", nil, err
+	}
+	return "stdin" + ext(sniff), io.MultiReader(bytes.NewReader(sniff), os.Stdin), nil
+}

cmd/tailscale/cli/status.go

@@ -10,22 +10,24 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"log"
 	"net"
 	"net/http"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
 	"github.com/toqueteos/webbrowser"
+	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/net/interfaces"
+	"tailscale.com/util/dnsname"
 )
 
 var statusCmd = &ffcli.Command{
 	Name:       "status",
-	ShortUsage: "status [-active] [-web] [-json]",
+	ShortUsage: "status [--active] [--web] [--json]",
 	ShortHelp:  "Show state of tailscaled and its connections",
 	Exec:       runStatus,
 	FlagSet: (func() *flag.FlagSet {
@@ -34,7 +36,8 @@ var statusCmd = &ffcli.Command{
 		fs.BoolVar(&statusArgs.web, "web", false, "run webserver with HTML showing status")
 		fs.BoolVar(&statusArgs.active, "active", false, "filter output to only peers with active sessions (not applicable to web mode)")
 		fs.BoolVar(&statusArgs.self, "self", true, "show status of local machine")
-		fs.StringVar(&statusArgs.listen, "listen", "127.0.0.1:8384", "listen address; use port 0 for automatic")
+		fs.BoolVar(&statusArgs.peers, "peers", true, "show status of peers")
+		fs.StringVar(&statusArgs.listen, "listen", "127.0.0.1:8384", "listen address for web mode; use port 0 for automatic")
 		fs.BoolVar(&statusArgs.browser, "browser", true, "Open a browser in web mode")
 		return fs
 	})(),
@@ -47,35 +50,11 @@ var statusArgs struct {
 	browser bool   // in web mode, whether to open browser
 	active  bool   // in CLI mode, filter output to only peers with active sessions
 	self    bool   // in CLI mode, show status of local machine
+	peers   bool   // in CLI mode, show status of peer machines
 }
 
 func runStatus(ctx context.Context, args []string) error {
-	c, bc, ctx, cancel := connect(ctx)
-	defer cancel()
-
-	bc.AllowVersionSkew = true
-
-	ch := make(chan *ipnstate.Status, 1)
-	bc.SetNotifyCallback(func(n ipn.Notify) {
-		if n.ErrMessage != nil {
-			log.Fatal(*n.ErrMessage)
-		}
-		if n.Status != nil {
-			ch <- n.Status
-		}
-	})
-	go pump(ctx, bc, c)
-
-	getStatus := func() (*ipnstate.Status, error) {
-		bc.RequestStatus()
-		select {
-		case st := <-ch:
-			return st, nil
-		case <-ctx.Done():
-			return nil, ctx.Err()
-		}
-	}
-	st, err := getStatus()
+	st, err := tailscale.Status(ctx)
 	if err != nil {
 		return err
 	}
@@ -113,7 +92,7 @@ func runStatus(ctx context.Context, args []string) error {
 				http.NotFound(w, r)
 				return
 			}
-			st, err := getStatus()
+			st, err := tailscale.Status(ctx)
 			if err != nil {
 				http.Error(w, err.Error(), 500)
 				return
@@ -136,30 +115,35 @@ func runStatus(ctx context.Context, args []string) error {
 	f := func(format string, a ...interface{}) { fmt.Fprintf(&buf, format, a...) }
 	printPS := func(ps *ipnstate.PeerStatus) {
 		active := peerActive(ps)
-		f("%s %-7s %-15s %-18s tx=%8d rx=%8d ",
-			ps.PublicKey.ShortString(),
-			ps.OS,
+		f("%-15s %-20s %-12s %-7s ",
 			ps.TailAddr,
-			ps.SimpleHostName(),
-			ps.TxBytes,
-			ps.RxBytes,
+			dnsOrQuoteHostname(st, ps),
+			ownerLogin(st, ps),
+			ps.OS,
 		)
 		relay := ps.Relay
-		if active && relay != "" && ps.CurAddr == "" {
-			relay = "*" + relay + "*"
-		} else {
-			relay = " " + relay
-		}
-		f("%-6s", relay)
-		for i, addr := range ps.Addrs {
-			if i != 0 {
-				f(", ")
-			}
-			if addr == ps.CurAddr {
-				f("*%s*", addr)
+		anyTraffic := ps.TxBytes != 0 || ps.RxBytes != 0
+		if !active {
+			if ps.ExitNode {
+				f("idle; exit node")
+			} else if anyTraffic {
+				f("idle")
 			} else {
-				f("%s", addr)
+				f("-")
 			}
+		} else {
+			f("active; ")
+			if ps.ExitNode {
+				f("exit node; ")
+			}
+			if relay != "" && ps.CurAddr == "" {
+				f("relay %q", relay)
+			} else if ps.CurAddr != "" {
+				f("direct %s", ps.CurAddr)
+			}
+		}
+		if anyTraffic {
+			f(", tx %d rx %d", ps.TxBytes, ps.RxBytes)
 		}
 		f("\n")
 	}
@@ -167,13 +151,23 @@ func runStatus(ctx context.Context, args []string) error {
 	if statusArgs.self && st.Self != nil {
 		printPS(st.Self)
 	}
-	for _, peer := range st.Peers() {
-		ps := st.Peer[peer]
-		active := peerActive(ps)
-		if statusArgs.active && !active {
-			continue
+	if statusArgs.peers {
+		var peers []*ipnstate.PeerStatus
+		for _, peer := range st.Peers() {
+			ps := st.Peer[peer]
+			if ps.ShareeNode {
+				continue
+			}
+			peers = append(peers, ps)
+		}
+		ipnstate.SortPeers(peers)
+		for _, ps := range peers {
+			active := peerActive(ps)
+			if statusArgs.active && !active {
+				continue
+			}
+			printPS(ps)
 		}
-		printPS(ps)
 	}
 	os.Stdout.Write(buf.Bytes())
 	return nil
@@ -185,3 +179,25 @@ func runStatus(ctx context.Context, args []string) error {
 func peerActive(ps *ipnstate.PeerStatus) bool {
 	return !ps.LastWrite.IsZero() && time.Since(ps.LastWrite) < 2*time.Minute
 }
+
+func dnsOrQuoteHostname(st *ipnstate.Status, ps *ipnstate.PeerStatus) string {
+	baseName := dnsname.TrimSuffix(ps.DNSName, st.MagicDNSSuffix)
+	if baseName != "" {
+		return baseName
+	}
+	return fmt.Sprintf("(%q)", dnsname.SanitizeHostname(ps.HostName))
+}
+
+func ownerLogin(st *ipnstate.Status, ps *ipnstate.PeerStatus) string {
+	if ps.UserID.IsZero() {
+		return "-"
+	}
+	u, ok := st.User[ps.UserID]
+	if !ok {
+		return fmt.Sprint(ps.UserID)
+	}
+	if i := strings.Index(u.LoginName, "@"); i != -1 {
+		return u.LoginName[:i+1]
+	}
+	return u.LoginName
+}

cmd/tailscale/cli/up.go

@@ -14,18 +14,18 @@ import (
 	"os"
 	"os/exec"
 	"runtime"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
-	"github.com/tailscale/wireguard-go/wgcfg"
 	"inet.af/netaddr"
+	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 	"tailscale.com/tailcfg"
-	"tailscale.com/version"
+	"tailscale.com/types/preftype"
 	"tailscale.com/version/distro"
-	"tailscale.com/wgengine/router"
 )
 
 var upCmd = &ffcli.Command{
@@ -46,13 +46,15 @@ specify any flags, options are reset to their default.
 		upf.BoolVar(&upArgs.acceptRoutes, "accept-routes", false, "accept routes advertised by other Tailscale nodes")
 		upf.BoolVar(&upArgs.acceptDNS, "accept-dns", true, "accept DNS configuration from the admin panel")
 		upf.BoolVar(&upArgs.singleRoutes, "host-routes", true, "install host routes to other Tailscale nodes")
+		upf.StringVar(&upArgs.exitNodeIP, "exit-node", "", "Tailscale IP of the exit node for internet traffic")
 		upf.BoolVar(&upArgs.shieldsUp, "shields-up", false, "don't allow incoming connections")
 		upf.BoolVar(&upArgs.forceReauth, "force-reauth", false, "force reauthentication")
-		upf.StringVar(&upArgs.advertiseTags, "advertise-tags", "", "ACL tags to request (comma-separated, e.g. eng,montreal,ssh)")
+		upf.StringVar(&upArgs.advertiseTags, "advertise-tags", "", "ACL tags to request (comma-separated, e.g. \"tag:eng,tag:montreal,tag:ssh\")")
 		upf.StringVar(&upArgs.authKey, "authkey", "", "node authorization key")
 		upf.StringVar(&upArgs.hostname, "hostname", "", "hostname to use instead of the one provided by the OS")
-		if runtime.GOOS == "linux" || isBSD(runtime.GOOS) || version.OS() == "macOS" {
-			upf.StringVar(&upArgs.advertiseRoutes, "advertise-routes", "", "routes to advertise to other nodes (comma-separated, e.g. 10.0.0.0/8,192.168.0.0/24)")
+		if runtime.GOOS == "linux" || isBSD(runtime.GOOS) {
+			upf.StringVar(&upArgs.advertiseRoutes, "advertise-routes", "", "routes to advertise to other nodes (comma-separated, e.g. \"10.0.0.0/8,192.168.0.0/24\")")
+			upf.BoolVar(&upArgs.advertiseDefaultRoute, "advertise-exit-node", false, "offer to be an exit node for internet traffic for the tailnet")
 		}
 		if runtime.GOOS == "linux" {
 			upf.BoolVar(&upArgs.snat, "snat-subnet-routes", true, "source NAT traffic to local routes advertised with --advertise-routes")
@@ -71,41 +73,20 @@ func defaultNetfilterMode() string {
 }
 
 var upArgs struct {
-	server          string
-	acceptRoutes    bool
-	acceptDNS       bool
-	singleRoutes    bool
-	shieldsUp       bool
-	forceReauth     bool
-	advertiseRoutes string
-	advertiseTags   string
-	snat            bool
-	netfilterMode   string
-	authKey         string
-	hostname        string
-}
-
-// parseIPOrCIDR parses an IP address or a CIDR prefix. If the input
-// is an IP address, it is returned in CIDR form with a /32 mask for
-// IPv4 or a /128 mask for IPv6.
-func parseIPOrCIDR(s string) (wgcfg.CIDR, bool) {
-	if strings.Contains(s, "/") {
-		ret, err := wgcfg.ParseCIDR(s)
-		if err != nil {
-			return wgcfg.CIDR{}, false
-		}
-		return ret, true
-	}
-
-	ip, ok := wgcfg.ParseIP(s)
-	if !ok {
-		return wgcfg.CIDR{}, false
-	}
-	if ip.Is4() {
-		return wgcfg.CIDR{IP: ip, Mask: 32}, true
-	} else {
-		return wgcfg.CIDR{IP: ip, Mask: 128}, true
-	}
+	server                string
+	acceptRoutes          bool
+	acceptDNS             bool
+	singleRoutes          bool
+	exitNodeIP            string
+	shieldsUp             bool
+	forceReauth           bool
+	advertiseRoutes       string
+	advertiseDefaultRoute bool
+	advertiseTags         string
+	snat                  bool
+	netfilterMode         string
+	authKey               string
+	hostname              string
 }
 
 func isBSD(s string) bool {
@@ -116,14 +97,14 @@ func warnf(format string, args ...interface{}) {
 	fmt.Printf("Warning: "+format+"\n", args...)
 }
 
-// checkIPForwarding prints warnings if IP forwarding is not
+// checkIPForwarding prints warnings on linux if IP forwarding is not
 // enabled, or if we were unable to verify the state of IP forwarding.
 func checkIPForwarding() {
 	var key string
 
 	if runtime.GOOS == "linux" {
 		key = "net.ipv4.ip_forward"
-	} else if isBSD(runtime.GOOS) || version.OS() == "macOS" {
+	} else if isBSD(runtime.GOOS) {
 		key = "net.inet.ip.forwarding"
 	} else {
 		return
@@ -144,6 +125,11 @@ func checkIPForwarding() {
 	}
 }
 
+var (
+	ipv4default = netaddr.MustParseIPPrefix("0.0.0.0/0")
+	ipv6default = netaddr.MustParseIPPrefix("::/0")
+)
+
 func runUp(ctx context.Context, args []string) error {
 	if len(args) > 0 {
 		log.Fatalf("too many non-flag arguments: %q", args)
@@ -157,43 +143,77 @@ func runUp(ctx context.Context, args []string) error {
 		if upArgs.acceptRoutes {
 			return errors.New("--accept-routes is " + notSupported)
 		}
+		if upArgs.exitNodeIP != "" {
+			return errors.New("--exit-node is " + notSupported)
+		}
 		if upArgs.netfilterMode != "off" {
 			return errors.New("--netfilter-mode values besides \"off\" " + notSupported)
 		}
 	}
 
-	var routes []wgcfg.CIDR
+	routeMap := map[netaddr.IPPrefix]bool{}
+	var default4, default6 bool
 	if upArgs.advertiseRoutes != "" {
 		advroutes := strings.Split(upArgs.advertiseRoutes, ",")
 		for _, s := range advroutes {
-			cidr, ok := parseIPOrCIDR(s)
-			ipp, err := netaddr.ParseIPPrefix(s) // parse it with other pawith both packages
-			if !ok || err != nil {
+			ipp, err := netaddr.ParseIPPrefix(s)
+			if err != nil {
 				fatalf("%q is not a valid IP address or CIDR prefix", s)
 			}
 			if ipp != ipp.Masked() {
 				fatalf("%s has non-address bits set; expected %s", ipp, ipp.Masked())
 			}
-			routes = append(routes, cidr)
+			if ipp == ipv4default {
+				default4 = true
+			} else if ipp == ipv6default {
+				default6 = true
+			}
+			routeMap[ipp] = true
 		}
+		if default4 && !default6 {
+			fatalf("%s advertised without its IPv6 counterpart, please also advertise %s", ipv4default, ipv6default)
+		} else if default6 && !default4 {
+			fatalf("%s advertised without its IPv6 counterpart, please also advertise %s", ipv6default, ipv4default)
+		}
+	}
+	if upArgs.advertiseDefaultRoute {
+		routeMap[netaddr.MustParseIPPrefix("0.0.0.0/0")] = true
+		routeMap[netaddr.MustParseIPPrefix("::/0")] = true
+	}
+	if len(routeMap) > 0 {
 		checkIPForwarding()
+		if isBSD(runtime.GOOS) {
+			warnf("Subnet routing and exit nodes only work with additional manual configuration on %v, and is not currently officially supported.", runtime.GOOS)
+		}
+	}
+	routes := make([]netaddr.IPPrefix, 0, len(routeMap))
+	for r := range routeMap {
+		routes = append(routes, r)
+	}
+	sort.Slice(routes, func(i, j int) bool {
+		if routes[i].Bits != routes[j].Bits {
+			return routes[i].Bits < routes[j].Bits
+		}
+		return routes[i].IP.Less(routes[j].IP)
+	})
+
+	var exitNodeIP netaddr.IP
+	if upArgs.exitNodeIP != "" {
+		var err error
+		exitNodeIP, err = netaddr.ParseIP(upArgs.exitNodeIP)
+		if err != nil {
+			fatalf("invalid IP address %q for --exit-node: %v", upArgs.exitNodeIP, err)
+		}
 	}
 
 	var tags []string
 	if upArgs.advertiseTags != "" {
 		tags = strings.Split(upArgs.advertiseTags, ",")
-		for i, tag := range tags {
-			if strings.HasPrefix(tag, "tag:") {
-				// Accept fully-qualified tags (starting with
-				// "tag:"), as we do in the ACL file.
-				err := tailcfg.CheckTag(tag)
-				if err != nil {
-					fatalf("tag: %q: %v", tag, err)
-				}
-			} else if err := tailcfg.CheckTagSuffix(tag); err != nil {
-				fatalf("tag: %q: %v", tag, err)
+		for _, tag := range tags {
+			err := tailcfg.CheckTag(tag)
+			if err != nil {
+				fatalf("tag: %q: %s", tag, err)
 			}
-			tags[i] = "tag:" + tag
 		}
 	}
 
@@ -201,11 +221,11 @@ func runUp(ctx context.Context, args []string) error {
 		fatalf("hostname too long: %d bytes (max 256)", len(upArgs.hostname))
 	}
 
-	// TODO(apenwarr): fix different semantics between prefs and uflags
 	prefs := ipn.NewPrefs()
 	prefs.ControlURL = upArgs.server
 	prefs.WantRunning = true
 	prefs.RouteAll = upArgs.acceptRoutes
+	prefs.ExitNodeIP = exitNodeIP
 	prefs.CorpDNS = upArgs.acceptDNS
 	prefs.AllowSingleHosts = upArgs.singleRoutes
 	prefs.ShieldsUp = upArgs.shieldsUp
@@ -218,12 +238,12 @@ func runUp(ctx context.Context, args []string) error {
 	if runtime.GOOS == "linux" {
 		switch upArgs.netfilterMode {
 		case "on":
-			prefs.NetfilterMode = router.NetfilterOn
+			prefs.NetfilterMode = preftype.NetfilterOn
 		case "nodivert":
-			prefs.NetfilterMode = router.NetfilterNoDivert
+			prefs.NetfilterMode = preftype.NetfilterNoDivert
 			warnf("netfilter=nodivert; add iptables calls to ts-* chains manually.")
 		case "off":
-			prefs.NetfilterMode = router.NetfilterOff
+			prefs.NetfilterMode = preftype.NetfilterOff
 			warnf("netfilter=off; configure iptables yourself.")
 		default:
 			fatalf("invalid value --netfilter-mode: %q", upArgs.netfilterMode)
@@ -233,6 +253,18 @@ func runUp(ctx context.Context, args []string) error {
 	c, bc, ctx, cancel := connect(ctx)
 	defer cancel()
 
+	if !prefs.ExitNodeIP.IsZero() {
+		st, err := tailscale.Status(ctx)
+		if err != nil {
+			fatalf("can't fetch status from tailscaled: %v", err)
+		}
+		for _, ip := range st.TailscaleIPs {
+			if prefs.ExitNodeIP == ip {
+				fatalf("cannot use %s as the exit node as it is a local IP address to this machine, did you mean --advertise-exit-node?", ip)
+			}
+		}
+	}
+
 	var printed bool
 	var loginOnce sync.Once
 	startLoginInteractive := func() { loginOnce.Do(func() { bc.StartLoginInteractive() }) }
@@ -244,7 +276,16 @@ func runUp(ctx context.Context, args []string) error {
 		AuthKey:  upArgs.authKey,
 		Notify: func(n ipn.Notify) {
 			if n.ErrMessage != nil {
-				fatalf("backend error: %v\n", *n.ErrMessage)
+				msg := *n.ErrMessage
+				if msg == ipn.ErrMsgPermissionDenied {
+					switch runtime.GOOS {
+					case "windows":
+						msg += " (Tailscale service in use by other user?)"
+					default:
+						msg += " (try 'sudo tailscale up [...]')"
+					}
+				}
+				fatalf("backend error: %v\n", msg)
 			}
 			if s := n.State; s != nil {
 				switch *s {
@@ -275,7 +316,7 @@ func runUp(ctx context.Context, args []string) error {
 	// supports server mode, though, the transition to StateStore
 	// is only half complete. Only server mode uses it, and the
 	// Windows service (~tailscaled) is the one that computes the
-	// StateKey based on the connection idenity. So for now, just
+	// StateKey based on the connection identity. So for now, just
 	// do as the Windows GUI's always done:
 	if runtime.GOOS == "windows" {
 		// The Windows service will set this as needed based

cmd/tailscale/cli/version.go

@@ -11,7 +11,7 @@ import (
 	"log"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/ipn"
+	"tailscale.com/client/tailscale"
 	"tailscale.com/version"
 )
 
@@ -42,29 +42,10 @@ func runVersion(ctx context.Context, args []string) error {
 
 	fmt.Printf("Client: %s\n", version.String())
 
-	c, bc, ctx, cancel := connect(ctx)
-	defer cancel()
-
-	bc.AllowVersionSkew = true
-
-	done := make(chan struct{})
-
-	bc.SetNotifyCallback(func(n ipn.Notify) {
-		if n.ErrMessage != nil {
-			log.Fatal(*n.ErrMessage)
-		}
-		if n.Status != nil {
-			fmt.Printf("Daemon: %s\n", n.Version)
-			close(done)
-		}
-	})
-	go pump(ctx, bc, c)
-
-	bc.RequestStatus()
-	select {
-	case <-done:
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
+	st, err := tailscale.StatusWithoutPeers(ctx)
+	if err != nil {
+		return err
 	}
+	fmt.Printf("Daemon: %s\n", st.Version)
+	return nil
 }

cmd/tailscale/cli/web.go

@@ -0,0 +1,212 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"bytes"
+	"context"
+	_ "embed"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"html/template"
+	"log"
+	"net/http"
+	"net/http/cgi"
+	"os/exec"
+	"runtime"
+
+	"github.com/peterbourgon/ff/v2/ffcli"
+	"tailscale.com/client/tailscale"
+	"tailscale.com/ipn"
+	"tailscale.com/types/preftype"
+	"tailscale.com/version/distro"
+)
+
+//go:embed web.html
+var webHTML string
+
+var tmpl = template.Must(template.New("html").Parse(webHTML))
+
+type tmplData struct {
+	SynologyUser string
+	Status       string
+	DeviceName   string
+	IP           string
+}
+
+var webCmd = &ffcli.Command{
+	Name:       "web",
+	ShortUsage: "web [flags]",
+	ShortHelp:  "Run a web server for controlling Tailscale",
+
+	FlagSet: (func() *flag.FlagSet {
+		webf := flag.NewFlagSet("web", flag.ExitOnError)
+		webf.StringVar(&webArgs.listen, "listen", "localhost:8088", "listen address; use port 0 for automatic")
+		webf.BoolVar(&webArgs.cgi, "cgi", false, "run as CGI script")
+		return webf
+	})(),
+	Exec: runWeb,
+}
+
+var webArgs struct {
+	listen string
+	cgi    bool
+}
+
+func runWeb(ctx context.Context, args []string) error {
+	if len(args) > 0 {
+		log.Fatalf("too many non-flag arguments: %q", args)
+	}
+
+	if webArgs.cgi {
+		return cgi.Serve(http.HandlerFunc(webHandler))
+	}
+	return http.ListenAndServe(webArgs.listen, http.HandlerFunc(webHandler))
+}
+
+func auth() (string, error) {
+	if distro.Get() == distro.Synology {
+		cmd := exec.Command("/usr/syno/synoman/webman/modules/authenticate.cgi")
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			return "", fmt.Errorf("auth: %v: %s", err, out)
+		}
+		return string(out), nil
+	}
+
+	return "", nil
+}
+
+func synoTokenRedirect(w http.ResponseWriter, r *http.Request) bool {
+	if distro.Get() != distro.Synology {
+		return false
+	}
+	if r.Header.Get("X-Syno-Token") != "" {
+		return false
+	}
+	if r.URL.Query().Get("SynoToken") != "" {
+		return false
+	}
+	if r.Method == "POST" && r.FormValue("SynoToken") != "" {
+		return false
+	}
+	// We need a SynoToken for authenticate.cgi.
+	// So we tell the client to get one.
+	serverURL := r.URL.Scheme + "://" + r.URL.Host
+	fmt.Fprintf(w, synoTokenRedirectHTML, serverURL)
+	return true
+}
+
+const synoTokenRedirectHTML = `<html><body>
+Redirecting with session token...
+<script>
+var serverURL = %q;
+var req = new XMLHttpRequest();
+req.overrideMimeType("application/json");
+req.open("GET", serverURL + "/webman/login.cgi", true);
+req.onload = function() {
+	var jsonResponse = JSON.parse(req.responseText);
+	var token = jsonResponse["SynoToken"];
+	document.location.href = serverURL + "/webman/3rdparty/Tailscale/?SynoToken=" + token;
+};
+req.send(null);
+</script>
+</body></html>
+`
+
+func webHandler(w http.ResponseWriter, r *http.Request) {
+	if synoTokenRedirect(w, r) {
+		return
+	}
+
+	user, err := auth()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusForbidden)
+		return
+	}
+
+	if r.Method == "POST" {
+		type mi map[string]interface{}
+		w.Header().Set("Content-Type", "application/json")
+		url, err := tailscaleUp(r.Context())
+		if err != nil {
+			json.NewEncoder(w).Encode(mi{"error": err})
+			return
+		}
+		json.NewEncoder(w).Encode(mi{"url": url})
+		return
+	}
+
+	st, err := tailscale.Status(r.Context())
+	if err != nil {
+		http.Error(w, err.Error(), 500)
+	}
+
+	data := tmplData{
+		SynologyUser: user,
+		Status:       st.BackendState,
+		DeviceName:   st.Self.DNSName,
+	}
+	if len(st.TailscaleIPs) != 0 {
+		data.IP = st.TailscaleIPs[0].String()
+	}
+
+	buf := new(bytes.Buffer)
+	if err := tmpl.Execute(buf, data); err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+	w.Write(buf.Bytes())
+}
+
+// TODO(crawshaw): some of this is very similar to the code in 'tailscale up', can we share anything?
+func tailscaleUp(ctx context.Context) (authURL string, retErr error) {
+	prefs := ipn.NewPrefs()
+	prefs.ControlURL = "https://login.tailscale.com"
+	prefs.WantRunning = true
+	prefs.CorpDNS = true
+	prefs.AllowSingleHosts = true
+	prefs.ForceDaemon = (runtime.GOOS == "windows")
+
+	if distro.Get() == distro.Synology {
+		prefs.NetfilterMode = preftype.NetfilterOff
+	}
+
+	c, bc, ctx, cancel := connect(ctx)
+	defer cancel()
+
+	bc.SetPrefs(prefs)
+
+	opts := ipn.Options{
+		StateKey: ipn.GlobalDaemonStateKey,
+		Notify: func(n ipn.Notify) {
+			if n.ErrMessage != nil {
+				msg := *n.ErrMessage
+				if msg == ipn.ErrMsgPermissionDenied {
+					switch runtime.GOOS {
+					case "windows":
+						msg += " (Tailscale service in use by other user?)"
+					default:
+						msg += " (try 'sudo tailscale up [...]')"
+					}
+				}
+				retErr = fmt.Errorf("backend error: %v", msg)
+				cancel()
+			} else if url := n.BrowseToURL; url != nil {
+				authURL = *url
+				cancel()
+			}
+		},
+	}
+	bc.Start(opts)
+	bc.StartLoginInteractive()
+	pump(ctx, bc, c)
+
+	if authURL == "" && retErr == nil {
+		return "", fmt.Errorf("login failed with no backend error message")
+	}
+	return authURL, retErr
+}

cmd/tailscale/cli/web.html

@@ -0,0 +1,47 @@
+<!doctype html>
+<html><title>Tailscale Client</title><body>
+<h1>Tailscale</h1>
+<div style="float:right;">{{.SynologyUser}}</div>
+<table>
+<tr><th>Status:</th><td>{{.Status}}</td></tr>
+<tr><th>Device Name:</th><td>{{.DeviceName}}</td></tr>
+<tr><th>Tailscale IP:</th><td>{{.IP}}</td></tr>
+</table>
+
+<p><input id="login" type="button" value="Log in…"></p>
+
+<script>
+login.onclick = function() {
+	const urlParams = new URLSearchParams(window.location.search);
+	const token = urlParams.get("SynoToken");
+
+	var params = new URLSearchParams("up=true");
+	if (token) {
+		params.set("SynoToken", token)
+	}
+
+	var req = new XMLHttpRequest();
+	const url = [location.protocol, '//', location.host, location.pathname, "?", params.toString()].join('');
+	req.overrideMimeType("application/json");
+	req.open("POST", url, true);
+	req.onload = function() {
+		var jsonResponse = JSON.parse(req.responseText);
+		const err = jsonResponse["error"];
+		if (err) {
+			document.body.innerText = err;
+			return
+		}
+		var url = jsonResponse["url"];
+		console.log("jsonResponse: ", jsonResponse);
+		if (url) {
+			document.location.href = url;
+		} else {
+			//location.reload();
+		}
+	};
+	req.send(null);
+}
+</script>
+
+</body>
+</html>

cmd/tailscale/depaware.txt

@@ -2,132 +2,92 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
 
    W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate
    W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
-        github.com/apenwarr/fixconsole                               from tailscale.com/cmd/tailscale
-   W 💣 github.com/apenwarr/w32                                      from github.com/apenwarr/fixconsole
-   L    github.com/coreos/go-iptables/iptables                       from tailscale.com/wgengine/router
-  LW    github.com/go-multierror/multierror                          from tailscale.com/wgengine/router
-   W 💣 github.com/go-ole/go-ole                                     from github.com/go-ole/go-ole/oleutil+
-   W 💣 github.com/go-ole/go-ole/oleutil                             from tailscale.com/wgengine/winnet
-   L 💣 github.com/godbus/dbus/v5                                    from tailscale.com/wgengine/router/dns
-        github.com/golang/groupcache/lru                             from tailscale.com/wgengine/filter+
-   L    github.com/jsimonetti/rtnetlink                              from tailscale.com/wgengine/monitor
-   L    github.com/jsimonetti/rtnetlink/internal/unix                from github.com/jsimonetti/rtnetlink
-   L 💣 github.com/mdlayher/netlink                                  from github.com/jsimonetti/rtnetlink+
-   L 💣 github.com/mdlayher/netlink/nlenc                            from github.com/jsimonetti/rtnetlink+
         github.com/peterbourgon/ff/v2                                from github.com/peterbourgon/ff/v2/ffcli
         github.com/peterbourgon/ff/v2/ffcli                          from tailscale.com/cmd/tailscale/cli
-     💣 github.com/tailscale/wireguard-go/conn                       from github.com/tailscale/wireguard-go/device+
-     💣 github.com/tailscale/wireguard-go/device                     from tailscale.com/wgengine+
-        github.com/tailscale/wireguard-go/device/tokenbucket         from github.com/tailscale/wireguard-go/device
-     💣 github.com/tailscale/wireguard-go/ipc                        from github.com/tailscale/wireguard-go/device
-   W 💣 github.com/tailscale/wireguard-go/ipc/winpipe                from github.com/tailscale/wireguard-go/ipc
-        github.com/tailscale/wireguard-go/ratelimiter                from github.com/tailscale/wireguard-go/device
-        github.com/tailscale/wireguard-go/replay                     from github.com/tailscale/wireguard-go/device
-        github.com/tailscale/wireguard-go/rwcancel                   from github.com/tailscale/wireguard-go/device+
-        github.com/tailscale/wireguard-go/tai64n                     from github.com/tailscale/wireguard-go/device
-     💣 github.com/tailscale/wireguard-go/tun                        from github.com/tailscale/wireguard-go/device+
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun                 from github.com/tailscale/wireguard-go/tun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/iphlpapi        from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/namespaceapi    from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/nci             from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/registry        from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/setupapi        from github.com/tailscale/wireguard-go/tun/wintun
-        github.com/tailscale/wireguard-go/wgcfg                      from github.com/tailscale/wireguard-go/conn+
         github.com/tcnksm/go-httpstat                                from tailscale.com/net/netcheck
         github.com/toqueteos/webbrowser                              from tailscale.com/cmd/tailscale/cli
-     💣 go4.org/mem                                                  from tailscale.com/control/controlclient+
+     💣 go4.org/intern                                               from inet.af/netaddr
+     💣 go4.org/mem                                                  from tailscale.com/derp+
+        go4.org/unsafe/assume-no-moving-gc                           from go4.org/intern
    W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
         inet.af/netaddr                                              from tailscale.com/cmd/tailscale/cli+
         rsc.io/goversion/version                                     from tailscale.com/version
-        tailscale.com/atomicfile                                     from tailscale.com/ipn+
+        tailscale.com/atomicfile                                     from tailscale.com/ipn
+        tailscale.com/client/tailscale                               from tailscale.com/cmd/tailscale/cli
         tailscale.com/cmd/tailscale/cli                              from tailscale.com/cmd/tailscale
-        tailscale.com/control/controlclient                          from tailscale.com/ipn+
-        tailscale.com/derp                                           from tailscale.com/derp/derphttp+
-        tailscale.com/derp/derphttp                                  from tailscale.com/cmd/tailscale/cli+
+        tailscale.com/derp                                           from tailscale.com/derp/derphttp
+        tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck
         tailscale.com/derp/derpmap                                   from tailscale.com/cmd/tailscale/cli
-        tailscale.com/disco                                          from tailscale.com/derp+
-        tailscale.com/internal/deepprint                             from tailscale.com/ipn+
+        tailscale.com/disco                                          from tailscale.com/derp
         tailscale.com/ipn                                            from tailscale.com/cmd/tailscale/cli
         tailscale.com/ipn/ipnstate                                   from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/ipn/policy                                     from tailscale.com/ipn
-        tailscale.com/log/logheap                                    from tailscale.com/control/controlclient
-        tailscale.com/logtail/backoff                                from tailscale.com/control/controlclient+
         tailscale.com/metrics                                        from tailscale.com/derp
-        tailscale.com/net/dnscache                                   from tailscale.com/cmd/tailscale/cli+
+        tailscale.com/net/dnscache                                   from tailscale.com/derp/derphttp
+        tailscale.com/net/flowtrack                                  from tailscale.com/wgengine/filter+
      💣 tailscale.com/net/interfaces                                 from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/net/netcheck                                   from tailscale.com/cmd/tailscale/cli+
-     💣 tailscale.com/net/netns                                      from tailscale.com/control/controlclient+
-        tailscale.com/net/stun                                       from tailscale.com/net/netcheck+
-        tailscale.com/net/tlsdial                                    from tailscale.com/control/controlclient+
-        tailscale.com/net/tsaddr                                     from tailscale.com/ipn+
-     💣 tailscale.com/net/tshttpproxy                                from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/paths                                          from tailscale.com/cmd/tailscale/cli
-        tailscale.com/portlist                                       from tailscale.com/ipn
-        tailscale.com/safesocket                                     from tailscale.com/cmd/tailscale/cli
-     💣 tailscale.com/syncs                                          from tailscale.com/net/interfaces+
+        tailscale.com/net/netcheck                                   from tailscale.com/cmd/tailscale/cli
+        tailscale.com/net/netns                                      from tailscale.com/derp/derphttp+
+        tailscale.com/net/packet                                     from tailscale.com/wgengine/filter
+        tailscale.com/net/portmapper                                 from tailscale.com/net/netcheck+
+        tailscale.com/net/stun                                       from tailscale.com/net/netcheck
+        tailscale.com/net/tlsdial                                    from tailscale.com/derp/derphttp
+        tailscale.com/net/tsaddr                                     from tailscale.com/net/interfaces
+     💣 tailscale.com/net/tshttpproxy                                from tailscale.com/derp/derphttp+
+        tailscale.com/paths                                          from tailscale.com/cmd/tailscale/cli+
+        tailscale.com/safesocket                                     from tailscale.com/cmd/tailscale/cli+
+        tailscale.com/syncs                                          from tailscale.com/net/interfaces+
         tailscale.com/tailcfg                                        from tailscale.com/cmd/tailscale/cli+
-  DW    tailscale.com/tempfork/osexec                                from tailscale.com/portlist
    W    tailscale.com/tsconst                                        from tailscale.com/net/interfaces
-        tailscale.com/types/empty                                    from tailscale.com/control/controlclient+
-        tailscale.com/types/key                                      from tailscale.com/cmd/tailscale/cli+
+        tailscale.com/types/empty                                    from tailscale.com/ipn
+        tailscale.com/types/ipproto                                  from tailscale.com/net/flowtrack+
+        tailscale.com/types/key                                      from tailscale.com/derp+
         tailscale.com/types/logger                                   from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/types/nettype                                  from tailscale.com/wgengine/magicsock
-        tailscale.com/types/opt                                      from tailscale.com/control/controlclient+
-        tailscale.com/types/strbuilder                               from tailscale.com/wgengine/packet
-        tailscale.com/types/structs                                  from tailscale.com/control/controlclient+
-        tailscale.com/util/lineread                                  from tailscale.com/control/controlclient+
+        tailscale.com/types/netmap                                   from tailscale.com/ipn
+        tailscale.com/types/opt                                      from tailscale.com/net/netcheck+
+        tailscale.com/types/persist                                  from tailscale.com/ipn
+        tailscale.com/types/preftype                                 from tailscale.com/cmd/tailscale/cli+
+        tailscale.com/types/strbuilder                               from tailscale.com/net/packet
+        tailscale.com/types/structs                                  from tailscale.com/ipn+
+        tailscale.com/types/wgkey                                    from tailscale.com/types/netmap+
+        tailscale.com/util/dnsname                                   from tailscale.com/cmd/tailscale/cli+
+   W    tailscale.com/util/endian                                    from tailscale.com/net/netns
+   L    tailscale.com/util/lineread                                  from tailscale.com/net/interfaces
         tailscale.com/version                                        from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/version/distro                                 from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/wgengine                                       from tailscale.com/ipn
-        tailscale.com/wgengine/filter                                from tailscale.com/control/controlclient+
-        tailscale.com/wgengine/magicsock                             from tailscale.com/wgengine
-     💣 tailscale.com/wgengine/monitor                               from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/wgengine/packet                                from tailscale.com/wgengine+
-        tailscale.com/wgengine/router                                from tailscale.com/cmd/tailscale/cli+
-     💣 tailscale.com/wgengine/router/dns                            from tailscale.com/ipn+
-        tailscale.com/wgengine/tsdns                                 from tailscale.com/ipn+
-        tailscale.com/wgengine/tstun                                 from tailscale.com/wgengine
-   W 💣 tailscale.com/wgengine/winnet                                from tailscale.com/wgengine/router
+        tailscale.com/version/distro                                 from tailscale.com/cmd/tailscale/cli
+        tailscale.com/wgengine/filter                                from tailscale.com/types/netmap
         golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box
-        golang.org/x/crypto/blake2s                                  from github.com/tailscale/wireguard-go/device+
         golang.org/x/crypto/chacha20                                 from golang.org/x/crypto/chacha20poly1305
         golang.org/x/crypto/chacha20poly1305                         from crypto/tls+
         golang.org/x/crypto/cryptobyte                               from crypto/ecdsa+
         golang.org/x/crypto/cryptobyte/asn1                          from crypto/ecdsa+
         golang.org/x/crypto/curve25519                               from crypto/tls+
         golang.org/x/crypto/hkdf                                     from crypto/tls
-        golang.org/x/crypto/nacl/box                                 from tailscale.com/control/controlclient+
+        golang.org/x/crypto/nacl/box                                 from tailscale.com/derp
         golang.org/x/crypto/nacl/secretbox                           from golang.org/x/crypto/nacl/box
-        golang.org/x/crypto/poly1305                                 from github.com/tailscale/wireguard-go/device+
+        golang.org/x/crypto/poly1305                                 from golang.org/x/crypto/chacha20poly1305+
         golang.org/x/crypto/salsa20/salsa                            from golang.org/x/crypto/nacl/box+
-        golang.org/x/net/bpf                                         from github.com/mdlayher/netlink+
-        golang.org/x/net/context/ctxhttp                             from golang.org/x/oauth2/internal
-        golang.org/x/net/dns/dnsmessage                              from net+
-        golang.org/x/net/http/httpguts                               from net/http
+        golang.org/x/net/dns/dnsmessage                              from net
+        golang.org/x/net/http/httpguts                               from net/http+
         golang.org/x/net/http/httpproxy                              from net/http
         golang.org/x/net/http2/hpack                                 from net/http
         golang.org/x/net/idna                                        from golang.org/x/net/http/httpguts+
-        golang.org/x/net/ipv4                                        from github.com/tailscale/wireguard-go/device
-        golang.org/x/net/ipv6                                        from github.com/tailscale/wireguard-go/device+
         golang.org/x/net/proxy                                       from tailscale.com/net/netns
-   D    golang.org/x/net/route                                       from net
-        golang.org/x/oauth2                                          from tailscale.com/control/controlclient+
-        golang.org/x/oauth2/internal                                 from golang.org/x/oauth2
+   D    golang.org/x/net/route                                       from net+
         golang.org/x/sync/errgroup                                   from tailscale.com/derp
         golang.org/x/sync/singleflight                               from tailscale.com/net/dnscache
         golang.org/x/sys/cpu                                         from golang.org/x/crypto/blake2b+
-  LD    golang.org/x/sys/unix                                        from github.com/jsimonetti/rtnetlink/internal/unix+
-   W    golang.org/x/sys/windows                                     from github.com/apenwarr/fixconsole+
-   W    golang.org/x/sys/windows/registry                            from github.com/tailscale/wireguard-go/tun/wintun+
+  LD    golang.org/x/sys/unix                                        from tailscale.com/net/netns+
+   W    golang.org/x/sys/windows                                     from golang.org/x/sys/windows/registry+
+   W    golang.org/x/sys/windows/registry                            from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg
         golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
         golang.org/x/text/transform                                  from golang.org/x/text/secure/bidirule+
         golang.org/x/text/unicode/bidi                               from golang.org/x/net/idna+
-        golang.org/x/text/unicode/norm                               from github.com/tailscale/wireguard-go/tun/wintun+
+        golang.org/x/text/unicode/norm                               from golang.org/x/net/idna
         golang.org/x/time/rate                                       from tailscale.com/types/logger+
         bufio                                                        from compress/flate+
         bytes                                                        from bufio+
         compress/flate                                               from compress/gzip+
-        compress/gzip                                                from net/http+
+        compress/gzip                                                from net/http
         compress/zlib                                                from debug/elf+
         container/list                                               from crypto/tls+
         context                                                      from crypto/tls+
@@ -155,7 +115,8 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         debug/elf                                                    from rsc.io/goversion/version
         debug/macho                                                  from rsc.io/goversion/version
         debug/pe                                                     from rsc.io/goversion/version
-        encoding                                                     from encoding/json+
+        embed                                                        from tailscale.com/cmd/tailscale/cli
+        encoding                                                     from encoding/json
         encoding/asn1                                                from crypto/x509+
         encoding/base64                                              from encoding/json+
         encoding/binary                                              from compress/gzip+
@@ -169,34 +130,36 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         hash                                                         from compress/zlib+
         hash/adler32                                                 from compress/zlib
         hash/crc32                                                   from compress/gzip+
-        hash/fnv                                                     from tailscale.com/wgengine/magicsock
-        html                                                         from tailscale.com/ipn/ipnstate
+        hash/maphash                                                 from go4.org/mem
+        html                                                         from tailscale.com/ipn/ipnstate+
+        html/template                                                from tailscale.com/cmd/tailscale/cli
         io                                                           from bufio+
-        io/ioutil                                                    from crypto/tls+
+        io/fs                                                        from crypto/rand+
+        io/ioutil                                                    from golang.org/x/sys/cpu+
         log                                                          from expvar+
         math                                                         from compress/flate+
         math/big                                                     from crypto/dsa+
         math/bits                                                    from compress/flate+
-        math/rand                                                    from github.com/mdlayher/netlink+
-        mime                                                         from golang.org/x/oauth2/internal+
+        math/rand                                                    from math/big+
+        mime                                                         from mime/multipart+
         mime/multipart                                               from net/http
         mime/quotedprintable                                         from mime/multipart
         net                                                          from crypto/tls+
         net/http                                                     from expvar+
+        net/http/cgi                                                 from tailscale.com/cmd/tailscale/cli
         net/http/httptrace                                           from github.com/tcnksm/go-httpstat+
         net/http/internal                                            from net/http
         net/textproto                                                from golang.org/x/net/http/httpguts+
         net/url                                                      from crypto/x509+
         os                                                           from crypto/rand+
-        os/exec                                                      from github.com/coreos/go-iptables/iptables+
+        os/exec                                                      from github.com/toqueteos/webbrowser+
         os/signal                                                    from tailscale.com/cmd/tailscale/cli
-   L    os/user                                                      from github.com/godbus/dbus/v5
         path                                                         from debug/dwarf+
         path/filepath                                                from crypto/x509+
         reflect                                                      from crypto/x509+
-        regexp                                                       from github.com/coreos/go-iptables/iptables+
+        regexp                                                       from rsc.io/goversion/version+
         regexp/syntax                                                from regexp
-        runtime/pprof                                                from tailscale.com/log/logheap+
+        runtime/debug                                                from golang.org/x/sync/singleflight
         sort                                                         from compress/flate+
         strconv                                                      from compress/flate+
         strings                                                      from bufio+
@@ -204,6 +167,8 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         sync/atomic                                                  from context+
         syscall                                                      from crypto/rand+
         text/tabwriter                                               from github.com/peterbourgon/ff/v2/ffcli+
+        text/template                                                from html/template
+        text/template/parse                                          from html/template+
         time                                                         from compress/gzip+
         unicode                                                      from bytes+
         unicode/utf16                                                from encoding/asn1+

cmd/tailscale/tailscale.go

@@ -8,20 +8,19 @@ package main // import "tailscale.com/cmd/tailscale"
 
 import (
 	"fmt"
-	"log"
 	"os"
+	"path/filepath"
+	"strings"
 
-	"github.com/apenwarr/fixconsole"
 	"tailscale.com/cmd/tailscale/cli"
 )
 
 func main() {
-	err := fixconsole.FixConsoleIfNeeded()
-	if err != nil {
-		log.Printf("fixConsoleOutput: %v\n", err)
+	args := os.Args[1:]
+	if name, _ := os.Executable(); strings.HasSuffix(filepath.Base(name), ".cgi") {
+		args = []string{"web", "-cgi"}
 	}
-
-	if err := cli.Run(os.Args[1:]); err != nil {
+	if err := cli.Run(args); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}

cmd/tailscaled/debug.go

@@ -0,0 +1,172 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"net/http/httptrace"
+	"net/url"
+	"os"
+	"time"
+
+	"tailscale.com/derp/derphttp"
+	"tailscale.com/derp/derpmap"
+	"tailscale.com/net/interfaces"
+	"tailscale.com/net/tshttpproxy"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/key"
+	"tailscale.com/wgengine/monitor"
+)
+
+var debugArgs struct {
+	monitor   bool
+	getURL    string
+	derpCheck string
+}
+
+var debugModeFunc = debugMode // so it can be addressable
+
+func debugMode(args []string) error {
+	fs := flag.NewFlagSet("debug", flag.ExitOnError)
+	fs.BoolVar(&debugArgs.monitor, "monitor", false, "If true, run link monitor forever. Precludes all other options.")
+	fs.StringVar(&debugArgs.getURL, "get-url", "", "If non-empty, fetch provided URL.")
+	fs.StringVar(&debugArgs.derpCheck, "derp", "", "if non-empty, test a DERP ping via named region code")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+	if len(fs.Args()) > 0 {
+		return errors.New("unknown non-flag debug subcommand arguments")
+	}
+	ctx := context.Background()
+	if debugArgs.derpCheck != "" {
+		return checkDerp(ctx, debugArgs.derpCheck)
+	}
+	if debugArgs.monitor {
+		return runMonitor(ctx)
+	}
+	if debugArgs.getURL != "" {
+		return getURL(ctx, debugArgs.getURL)
+	}
+	return errors.New("only --monitor is available at the moment")
+}
+
+func runMonitor(ctx context.Context) error {
+	dump := func(st *interfaces.State) {
+		j, _ := json.MarshalIndent(st, "", "    ")
+		os.Stderr.Write(j)
+	}
+	mon, err := monitor.New(log.Printf)
+	if err != nil {
+		return err
+	}
+	mon.RegisterChangeCallback(func(changed bool, st *interfaces.State) {
+		if !changed {
+			log.Printf("Link monitor fired; no change")
+			return
+		}
+		log.Printf("Link monitor fired. New state:")
+		dump(st)
+	})
+	log.Printf("Starting link change monitor; initial state:")
+	dump(mon.InterfaceState())
+	mon.Start()
+	log.Printf("Started link change monitor; waiting...")
+	select {}
+}
+
+func getURL(ctx context.Context, urlStr string) error {
+	if urlStr == "login" {
+		urlStr = "https://login.tailscale.com"
+	}
+	log.SetOutput(os.Stdout)
+	ctx = httptrace.WithClientTrace(ctx, &httptrace.ClientTrace{
+		GetConn:           func(hostPort string) { log.Printf("GetConn(%q)", hostPort) },
+		GotConn:           func(info httptrace.GotConnInfo) { log.Printf("GotConn: %+v", info) },
+		DNSStart:          func(info httptrace.DNSStartInfo) { log.Printf("DNSStart: %+v", info) },
+		DNSDone:           func(info httptrace.DNSDoneInfo) { log.Printf("DNSDoneInfo: %+v", info) },
+		TLSHandshakeStart: func() { log.Printf("TLSHandshakeStart") },
+		TLSHandshakeDone:  func(cs tls.ConnectionState, err error) { log.Printf("TLSHandshakeDone: %+v, %v", cs, err) },
+		WroteRequest:      func(info httptrace.WroteRequestInfo) { log.Printf("WroteRequest: %+v", info) },
+	})
+	req, err := http.NewRequestWithContext(ctx, "GET", urlStr, nil)
+	if err != nil {
+		return fmt.Errorf("http.NewRequestWithContext: %v", err)
+	}
+	proxyURL, err := tshttpproxy.ProxyFromEnvironment(req)
+	if err != nil {
+		return fmt.Errorf("tshttpproxy.ProxyFromEnvironment: %v", err)
+	}
+	log.Printf("proxy: %v", proxyURL)
+	tr := &http.Transport{
+		Proxy:              func(*http.Request) (*url.URL, error) { return proxyURL, nil },
+		ProxyConnectHeader: http.Header{},
+		DisableKeepAlives:  true,
+	}
+	if proxyURL != nil {
+		auth, err := tshttpproxy.GetAuthHeader(proxyURL)
+		if err == nil && auth != "" {
+			tr.ProxyConnectHeader.Set("Proxy-Authorization", auth)
+		}
+		const truncLen = 20
+		if len(auth) > truncLen {
+			auth = fmt.Sprintf("%s...(%d total bytes)", auth[:truncLen], len(auth))
+		}
+		log.Printf("tshttpproxy.GetAuthHeader(%v) for Proxy-Auth: = %q, %v", proxyURL, auth, err)
+	}
+	res, err := tr.RoundTrip(req)
+	if err != nil {
+		return fmt.Errorf("Transport.RoundTrip: %v", err)
+	}
+	defer res.Body.Close()
+	return res.Write(os.Stdout)
+}
+
+func checkDerp(ctx context.Context, derpRegion string) error {
+	dmap := derpmap.Prod()
+	getRegion := func() *tailcfg.DERPRegion {
+		for _, r := range dmap.Regions {
+			if r.RegionCode == derpRegion {
+				return r
+			}
+		}
+		for _, r := range dmap.Regions {
+			log.Printf("Known region: %q", r.RegionCode)
+		}
+		log.Fatalf("unknown region %q", derpRegion)
+		panic("unreachable")
+	}
+
+	priv1 := key.NewPrivate()
+	priv2 := key.NewPrivate()
+
+	c1 := derphttp.NewRegionClient(priv1, log.Printf, getRegion)
+	c2 := derphttp.NewRegionClient(priv2, log.Printf, getRegion)
+
+	c2.NotePreferred(true) // just to open it
+
+	m, err := c2.Recv()
+	log.Printf("c2 got %T, %v", m, err)
+
+	t0 := time.Now()
+	if err := c1.Send(priv2.Public(), []byte("hello")); err != nil {
+		return err
+	}
+	fmt.Println(time.Since(t0))
+
+	m, err = c2.Recv()
+	log.Printf("c2 got %T, %v", m, err)
+	if err != nil {
+		return err
+	}
+	log.Printf("ok")
+	return err
+}

cmd/tailscaled/depaware.txt

@@ -2,15 +2,15 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
 
    W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate
    W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
-        github.com/apenwarr/fixconsole                               from tailscale.com/cmd/tailscaled
-   W 💣 github.com/apenwarr/w32                                      from github.com/apenwarr/fixconsole
    L    github.com/coreos/go-iptables/iptables                       from tailscale.com/wgengine/router
-  LW    github.com/go-multierror/multierror                          from tailscale.com/wgengine/router
+   W 💣 github.com/github/certstore                                  from tailscale.com/control/controlclient
+        github.com/go-multierror/multierror                          from tailscale.com/wgengine/router+
    W 💣 github.com/go-ole/go-ole                                     from github.com/go-ole/go-ole/oleutil+
    W 💣 github.com/go-ole/go-ole/oleutil                             from tailscale.com/wgengine/winnet
-   L 💣 github.com/godbus/dbus/v5                                    from tailscale.com/wgengine/router/dns
-        github.com/golang/groupcache/lru                             from tailscale.com/wgengine/filter+
-   L    github.com/jsimonetti/rtnetlink                              from tailscale.com/wgengine/monitor
+   L 💣 github.com/godbus/dbus/v5                                    from tailscale.com/net/dns
+        github.com/google/btree                                      from inet.af/netstack/tcpip/header+
+   L    github.com/josharian/native                                  from github.com/mdlayher/netlink+
+   L 💣 github.com/jsimonetti/rtnetlink                              from tailscale.com/wgengine/monitor
    L    github.com/jsimonetti/rtnetlink/internal/unix                from github.com/jsimonetti/rtnetlink
         github.com/klauspost/compress/fse                            from github.com/klauspost/compress/huff0
         github.com/klauspost/compress/huff0                          from github.com/klauspost/compress/zstd
@@ -19,38 +19,70 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         github.com/klauspost/compress/zstd/internal/xxhash           from github.com/klauspost/compress/zstd
    L 💣 github.com/mdlayher/netlink                                  from github.com/jsimonetti/rtnetlink+
    L 💣 github.com/mdlayher/netlink/nlenc                            from github.com/jsimonetti/rtnetlink+
+   L    github.com/mdlayher/sdnotify                                 from tailscale.com/util/systemd
+   W    github.com/pkg/errors                                        from github.com/github/certstore
      💣 github.com/tailscale/wireguard-go/conn                       from github.com/tailscale/wireguard-go/device+
      💣 github.com/tailscale/wireguard-go/device                     from tailscale.com/wgengine+
-        github.com/tailscale/wireguard-go/device/tokenbucket         from github.com/tailscale/wireguard-go/device
      💣 github.com/tailscale/wireguard-go/ipc                        from github.com/tailscale/wireguard-go/device
    W 💣 github.com/tailscale/wireguard-go/ipc/winpipe                from github.com/tailscale/wireguard-go/ipc
         github.com/tailscale/wireguard-go/ratelimiter                from github.com/tailscale/wireguard-go/device
         github.com/tailscale/wireguard-go/replay                     from github.com/tailscale/wireguard-go/device
         github.com/tailscale/wireguard-go/rwcancel                   from github.com/tailscale/wireguard-go/device+
-        github.com/tailscale/wireguard-go/tai64n                     from github.com/tailscale/wireguard-go/device
+        github.com/tailscale/wireguard-go/tai64n                     from github.com/tailscale/wireguard-go/device+
      💣 github.com/tailscale/wireguard-go/tun                        from github.com/tailscale/wireguard-go/device+
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun                 from github.com/tailscale/wireguard-go/tun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/iphlpapi        from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/namespaceapi    from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/nci             from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/registry        from github.com/tailscale/wireguard-go/tun/wintun
-   W 💣 github.com/tailscale/wireguard-go/tun/wintun/setupapi        from github.com/tailscale/wireguard-go/tun/wintun
-        github.com/tailscale/wireguard-go/wgcfg                      from github.com/tailscale/wireguard-go/conn+
+   W 💣 github.com/tailscale/wireguard-go/tun/wintun                 from github.com/tailscale/wireguard-go/tun+
         github.com/tcnksm/go-httpstat                                from tailscale.com/net/netcheck
+     💣 go4.org/intern                                               from inet.af/netaddr
      💣 go4.org/mem                                                  from tailscale.com/control/controlclient+
+        go4.org/unsafe/assume-no-moving-gc                           from go4.org/intern
    W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
         inet.af/netaddr                                              from tailscale.com/control/controlclient+
+     💣 inet.af/netstack/gohacks                                     from inet.af/netstack/state/wire+
+        inet.af/netstack/linewriter                                  from inet.af/netstack/log
+        inet.af/netstack/log                                         from inet.af/netstack/state+
+        inet.af/netstack/rand                                        from inet.af/netstack/tcpip/network/hash+
+     💣 inet.af/netstack/sleep                                       from inet.af/netstack/tcpip/transport/tcp
+     💣 inet.af/netstack/state                                       from inet.af/netstack/tcpip+
+        inet.af/netstack/state/wire                                  from inet.af/netstack/state
+     💣 inet.af/netstack/sync                                        from inet.af/netstack/linewriter+
+     💣 inet.af/netstack/tcpip                                       from inet.af/netstack/tcpip/adapters/gonet+
+        inet.af/netstack/tcpip/adapters/gonet                        from tailscale.com/wgengine/netstack
+     💣 inet.af/netstack/tcpip/buffer                                from inet.af/netstack/tcpip/adapters/gonet+
+        inet.af/netstack/tcpip/hash/jenkins                          from inet.af/netstack/tcpip/stack+
+        inet.af/netstack/tcpip/header                                from inet.af/netstack/tcpip/header/parse+
+        inet.af/netstack/tcpip/header/parse                          from inet.af/netstack/tcpip/network/ipv4+
+        inet.af/netstack/tcpip/link/channel                          from tailscale.com/wgengine/netstack
+        inet.af/netstack/tcpip/network/hash                          from inet.af/netstack/tcpip/network/ipv4+
+        inet.af/netstack/tcpip/network/internal/fragmentation        from inet.af/netstack/tcpip/network/ipv4+
+        inet.af/netstack/tcpip/network/internal/ip                   from inet.af/netstack/tcpip/network/ipv4+
+        inet.af/netstack/tcpip/network/ipv4                          from tailscale.com/wgengine/netstack
+        inet.af/netstack/tcpip/network/ipv6                          from tailscale.com/wgengine/netstack
+        inet.af/netstack/tcpip/ports                                 from inet.af/netstack/tcpip/stack+
+        inet.af/netstack/tcpip/seqnum                                from inet.af/netstack/tcpip/header+
+     💣 inet.af/netstack/tcpip/stack                                 from inet.af/netstack/tcpip/adapters/gonet+
+        inet.af/netstack/tcpip/transport/icmp                        from tailscale.com/wgengine/netstack
+        inet.af/netstack/tcpip/transport/packet                      from inet.af/netstack/tcpip/transport/raw
+        inet.af/netstack/tcpip/transport/raw                         from inet.af/netstack/tcpip/transport/icmp+
+     💣 inet.af/netstack/tcpip/transport/tcp                         from inet.af/netstack/tcpip/adapters/gonet+
+        inet.af/netstack/tcpip/transport/tcpconntrack                from inet.af/netstack/tcpip/stack
+        inet.af/netstack/tcpip/transport/udp                         from inet.af/netstack/tcpip/adapters/gonet+
+        inet.af/netstack/waiter                                      from inet.af/netstack/tcpip+
+        inet.af/peercred                                             from tailscale.com/ipn/ipnserver
         rsc.io/goversion/version                                     from tailscale.com/version
         tailscale.com/atomicfile                                     from tailscale.com/ipn+
-        tailscale.com/control/controlclient                          from tailscale.com/ipn+
+        tailscale.com/control/controlclient                          from tailscale.com/ipn/ipnlocal+
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck+
+        tailscale.com/derp/derpmap                                   from tailscale.com/cmd/tailscaled+
         tailscale.com/disco                                          from tailscale.com/derp+
-        tailscale.com/internal/deepprint                             from tailscale.com/ipn+
-        tailscale.com/ipn                                            from tailscale.com/ipn/ipnserver
+        tailscale.com/health                                         from tailscale.com/control/controlclient+
+        tailscale.com/internal/deepprint                             from tailscale.com/ipn/ipnlocal+
+        tailscale.com/ipn                                            from tailscale.com/ipn/ipnserver+
+        tailscale.com/ipn/ipnlocal                                   from tailscale.com/ipn/ipnserver+
         tailscale.com/ipn/ipnserver                                  from tailscale.com/cmd/tailscaled
         tailscale.com/ipn/ipnstate                                   from tailscale.com/ipn+
-        tailscale.com/ipn/policy                                     from tailscale.com/ipn
+        tailscale.com/ipn/localapi                                   from tailscale.com/ipn/ipnserver
+        tailscale.com/ipn/policy                                     from tailscale.com/ipn/ipnlocal
         tailscale.com/log/filelogger                                 from tailscale.com/ipn/ipnserver
         tailscale.com/log/logheap                                    from tailscale.com/control/controlclient
         tailscale.com/logpolicy                                      from tailscale.com/cmd/tailscaled
@@ -58,44 +90,63 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/logtail/backoff                                from tailscale.com/control/controlclient+
         tailscale.com/logtail/filch                                  from tailscale.com/logpolicy
         tailscale.com/metrics                                        from tailscale.com/derp
-        tailscale.com/net/dnscache                                   from tailscale.com/derp/derphttp+
-     💣 tailscale.com/net/interfaces                                 from tailscale.com/ipn+
+        tailscale.com/net/dns                                        from tailscale.com/ipn/ipnlocal+
+        tailscale.com/net/dnscache                                   from tailscale.com/control/controlclient+
+        tailscale.com/net/dnsfallback                                from tailscale.com/control/controlclient
+        tailscale.com/net/flowtrack                                  from tailscale.com/wgengine/filter+
+     💣 tailscale.com/net/interfaces                                 from tailscale.com/cmd/tailscaled+
         tailscale.com/net/netcheck                                   from tailscale.com/wgengine/magicsock
-     💣 tailscale.com/net/netns                                      from tailscale.com/control/controlclient+
+        tailscale.com/net/netns                                      from tailscale.com/control/controlclient+
      💣 tailscale.com/net/netstat                                    from tailscale.com/ipn/ipnserver
+        tailscale.com/net/packet                                     from tailscale.com/wgengine+
+        tailscale.com/net/portmapper                                 from tailscale.com/net/netcheck+
+        tailscale.com/net/socks5                                     from tailscale.com/cmd/tailscaled
         tailscale.com/net/stun                                       from tailscale.com/net/netcheck+
         tailscale.com/net/tlsdial                                    from tailscale.com/control/controlclient+
-        tailscale.com/net/tsaddr                                     from tailscale.com/ipn+
+        tailscale.com/net/tsaddr                                     from tailscale.com/ipn/ipnlocal+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/control/controlclient+
+        tailscale.com/net/tstun                                      from tailscale.com/cmd/tailscaled+
         tailscale.com/paths                                          from tailscale.com/cmd/tailscaled+
-        tailscale.com/portlist                                       from tailscale.com/ipn
+        tailscale.com/portlist                                       from tailscale.com/ipn/ipnlocal
         tailscale.com/safesocket                                     from tailscale.com/ipn/ipnserver
         tailscale.com/smallzstd                                      from tailscale.com/ipn/ipnserver+
-     💣 tailscale.com/syncs                                          from tailscale.com/net/interfaces+
+        tailscale.com/syncs                                          from tailscale.com/net/interfaces+
         tailscale.com/tailcfg                                        from tailscale.com/control/controlclient+
-  DW    tailscale.com/tempfork/osexec                                from tailscale.com/portlist
+   W 💣 tailscale.com/tempfork/wireguard-windows/firewall            from tailscale.com/cmd/tailscaled
    W    tailscale.com/tsconst                                        from tailscale.com/net/interfaces
+        tailscale.com/tstime                                         from tailscale.com/wgengine/magicsock
         tailscale.com/types/empty                                    from tailscale.com/control/controlclient+
         tailscale.com/types/flagtype                                 from tailscale.com/cmd/tailscaled
+        tailscale.com/types/ipproto                                  from tailscale.com/net/flowtrack+
         tailscale.com/types/key                                      from tailscale.com/derp+
         tailscale.com/types/logger                                   from tailscale.com/cmd/tailscaled+
+        tailscale.com/types/netmap                                   from tailscale.com/control/controlclient+
         tailscale.com/types/nettype                                  from tailscale.com/wgengine/magicsock
         tailscale.com/types/opt                                      from tailscale.com/control/controlclient+
-        tailscale.com/types/strbuilder                               from tailscale.com/wgengine/packet
+        tailscale.com/types/pad32                                    from tailscale.com/wgengine/magicsock
+        tailscale.com/types/persist                                  from tailscale.com/control/controlclient+
+        tailscale.com/types/preftype                                 from tailscale.com/ipn+
+        tailscale.com/types/strbuilder                               from tailscale.com/net/packet
         tailscale.com/types/structs                                  from tailscale.com/control/controlclient+
-        tailscale.com/util/lineread                                  from tailscale.com/control/controlclient+
+        tailscale.com/types/wgkey                                    from tailscale.com/control/controlclient+
+        tailscale.com/util/dnsname                                   from tailscale.com/ipn/ipnstate+
+  LW    tailscale.com/util/endian                                    from tailscale.com/net/netns+
+   L    tailscale.com/util/lineread                                  from tailscale.com/control/controlclient+
         tailscale.com/util/pidowner                                  from tailscale.com/ipn/ipnserver
+        tailscale.com/util/racebuild                                 from tailscale.com/logpolicy
+        tailscale.com/util/systemd                                   from tailscale.com/control/controlclient+
+        tailscale.com/util/winutil                                   from tailscale.com/logpolicy+
         tailscale.com/version                                        from tailscale.com/cmd/tailscaled+
         tailscale.com/version/distro                                 from tailscale.com/control/controlclient+
         tailscale.com/wgengine                                       from tailscale.com/cmd/tailscaled+
         tailscale.com/wgengine/filter                                from tailscale.com/control/controlclient+
         tailscale.com/wgengine/magicsock                             from tailscale.com/cmd/tailscaled+
-     💣 tailscale.com/wgengine/monitor                               from tailscale.com/wgengine
-        tailscale.com/wgengine/packet                                from tailscale.com/wgengine+
+        tailscale.com/wgengine/monitor                               from tailscale.com/wgengine+
+        tailscale.com/wgengine/netstack                              from tailscale.com/cmd/tailscaled
         tailscale.com/wgengine/router                                from tailscale.com/cmd/tailscaled+
-     💣 tailscale.com/wgengine/router/dns                            from tailscale.com/ipn+
-        tailscale.com/wgengine/tsdns                                 from tailscale.com/ipn+
-        tailscale.com/wgengine/tstun                                 from tailscale.com/wgengine
+        tailscale.com/wgengine/wgcfg                                 from tailscale.com/ipn/ipnlocal+
+        tailscale.com/wgengine/wgcfg/nmcfg                           from tailscale.com/ipn/ipnlocal
+        tailscale.com/wgengine/wglog                                 from tailscale.com/wgengine
    W 💣 tailscale.com/wgengine/winnet                                from tailscale.com/wgengine/router
         golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box
         golang.org/x/crypto/blake2s                                  from github.com/tailscale/wireguard-go/device+
@@ -109,9 +160,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         golang.org/x/crypto/nacl/secretbox                           from golang.org/x/crypto/nacl/box
         golang.org/x/crypto/poly1305                                 from github.com/tailscale/wireguard-go/device+
         golang.org/x/crypto/salsa20/salsa                            from golang.org/x/crypto/nacl/box+
-        golang.org/x/crypto/ssh/terminal                             from tailscale.com/logpolicy
         golang.org/x/net/bpf                                         from github.com/mdlayher/netlink+
-        golang.org/x/net/context/ctxhttp                             from golang.org/x/oauth2/internal
         golang.org/x/net/dns/dnsmessage                              from net+
         golang.org/x/net/http/httpguts                               from net/http
         golang.org/x/net/http/httpproxy                              from net/http
@@ -120,25 +169,26 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         golang.org/x/net/ipv4                                        from github.com/tailscale/wireguard-go/device
         golang.org/x/net/ipv6                                        from github.com/tailscale/wireguard-go/device+
         golang.org/x/net/proxy                                       from tailscale.com/net/netns
-   D    golang.org/x/net/route                                       from net
-        golang.org/x/oauth2                                          from tailscale.com/control/controlclient+
-        golang.org/x/oauth2/internal                                 from golang.org/x/oauth2
+   D    golang.org/x/net/route                                       from net+
         golang.org/x/sync/errgroup                                   from tailscale.com/derp
         golang.org/x/sync/singleflight                               from tailscale.com/net/dnscache
         golang.org/x/sys/cpu                                         from golang.org/x/crypto/blake2b+
   LD    golang.org/x/sys/unix                                        from github.com/jsimonetti/rtnetlink/internal/unix+
-   W    golang.org/x/sys/windows                                     from github.com/apenwarr/fixconsole+
-   W    golang.org/x/sys/windows/registry                            from github.com/tailscale/wireguard-go/tun/wintun+
+   W    golang.org/x/sys/windows                                     from github.com/tailscale/wireguard-go/conn+
+   W    golang.org/x/sys/windows/registry                            from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg+
+   W    golang.org/x/sys/windows/svc                                 from tailscale.com/cmd/tailscaled
+        golang.org/x/term                                            from tailscale.com/logpolicy
         golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
         golang.org/x/text/transform                                  from golang.org/x/text/secure/bidirule+
         golang.org/x/text/unicode/bidi                               from golang.org/x/net/idna+
-        golang.org/x/text/unicode/norm                               from github.com/tailscale/wireguard-go/tun/wintun+
+        golang.org/x/text/unicode/norm                               from golang.org/x/net/idna
         golang.org/x/time/rate                                       from tailscale.com/types/logger+
         bufio                                                        from compress/flate+
         bytes                                                        from bufio+
         compress/flate                                               from compress/gzip+
         compress/gzip                                                from internal/profile+
         compress/zlib                                                from debug/elf+
+        container/heap                                               from inet.af/netstack/tcpip/transport/tcp
         container/list                                               from crypto/tls+
         context                                                      from crypto/tls+
         crypto                                                       from crypto/ecdsa+
@@ -179,17 +229,18 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         hash                                                         from compress/zlib+
         hash/adler32                                                 from compress/zlib
         hash/crc32                                                   from compress/gzip+
-        hash/fnv                                                     from tailscale.com/wgengine/magicsock
-        html                                                         from html/template+
-        html/template                                                from net/http/pprof
+        hash/fnv                                                     from tailscale.com/wgengine/magicsock+
+        hash/maphash                                                 from go4.org/mem
+        html                                                         from net/http/pprof+
         io                                                           from bufio+
-        io/ioutil                                                    from crypto/tls+
+        io/fs                                                        from crypto/rand+
+        io/ioutil                                                    from github.com/godbus/dbus/v5+
         log                                                          from expvar+
         math                                                         from compress/flate+
         math/big                                                     from crypto/dsa+
         math/bits                                                    from compress/flate+
         math/rand                                                    from github.com/mdlayher/netlink+
-        mime                                                         from golang.org/x/oauth2/internal+
+        mime                                                         from mime/multipart+
         mime/multipart                                               from net/http
         mime/quotedprintable                                         from mime/multipart
         net                                                          from crypto/tls+
@@ -218,8 +269,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         sync/atomic                                                  from context+
         syscall                                                      from crypto/rand+
         text/tabwriter                                               from runtime/pprof
-        text/template                                                from html/template
-        text/template/parse                                          from html/template+
         time                                                         from compress/gzip+
         unicode                                                      from bytes+
         unicode/utf16                                                from encoding/asn1+

cmd/tailscaled/install_darwin.go

@@ -0,0 +1,146 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+func init() {
+	installSystemDaemon = installSystemDaemonDarwin
+	uninstallSystemDaemon = uninstallSystemDaemonDarwin
+}
+
+// darwinLaunchdPlist is the launchd.plist that's written to
+// /Library/LaunchDaemons/com.tailscale.tailscaled.plist or (in the
+// future) a user-specific location.
+//
+// See man launchd.plist.
+const darwinLaunchdPlist = `
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+
+  <key>Label</key>
+  <string>com.tailscale.tailscaled</string>
+
+  <key>ProgramArguments</key>
+  <array>
+    <string>/usr/local/bin/tailscaled</string>
+  </array>
+
+  <key>RunAtLoad</key>
+  <true/>
+
+</dict>
+</plist>
+`
+
+const sysPlist = "/Library/LaunchDaemons/com.tailscale.tailscaled.plist"
+const targetBin = "/usr/local/bin/tailscaled"
+const service = "com.tailscale.tailscaled"
+
+func uninstallSystemDaemonDarwin(args []string) (ret error) {
+	if len(args) > 0 {
+		return errors.New("uninstall subcommand takes no arguments")
+	}
+
+	plist, err := exec.Command("launchctl", "list", "com.tailscale.tailscaled").Output()
+	_ = plist // parse it? https://github.com/DHowett/go-plist if we need something.
+	running := err == nil
+
+	if running {
+		out, err := exec.Command("launchctl", "stop", "com.tailscale.tailscaled").CombinedOutput()
+		if err != nil {
+			fmt.Printf("launchctl stop com.tailscale.tailscaled: %v, %s\n", err, out)
+			ret = err
+		}
+		out, err = exec.Command("launchctl", "unload", sysPlist).CombinedOutput()
+		if err != nil {
+			fmt.Printf("launchctl unload %s: %v, %s\n", sysPlist, err, out)
+			if ret == nil {
+				ret = err
+			}
+		}
+	}
+
+	err = os.Remove(sysPlist)
+	if os.IsNotExist(err) {
+		err = nil
+		if ret == nil {
+			ret = err
+		}
+	}
+	return ret
+}
+
+func installSystemDaemonDarwin(args []string) (err error) {
+	if len(args) > 0 {
+		return errors.New("install subcommand takes no arguments")
+	}
+	defer func() {
+		if err != nil && os.Getuid() != 0 {
+			err = fmt.Errorf("%w; try running tailscaled with sudo", err)
+		}
+	}()
+
+	// Copy ourselves to /usr/local/bin/tailscaled.
+	if err := os.MkdirAll(filepath.Dir(targetBin), 0755); err != nil {
+		return err
+	}
+	exe, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("failed to find our own executable path: %w", err)
+	}
+	tmpBin := targetBin + ".tmp"
+	f, err := os.Create(tmpBin)
+	if err != nil {
+		return err
+	}
+	self, err := os.Open(exe)
+	if err != nil {
+		f.Close()
+		return err
+	}
+	_, err = io.Copy(f, self)
+	self.Close()
+	if err != nil {
+		f.Close()
+		return err
+	}
+	if err := f.Close(); err != nil {
+		return err
+	}
+	if err := os.Chmod(tmpBin, 0755); err != nil {
+		return err
+	}
+	if err := os.Rename(tmpBin, targetBin); err != nil {
+		return err
+	}
+
+	// Best effort:
+	uninstallSystemDaemonDarwin(nil)
+
+	if err := ioutil.WriteFile(sysPlist, []byte(darwinLaunchdPlist), 0700); err != nil {
+		return err
+	}
+
+	if out, err := exec.Command("launchctl", "load", sysPlist).CombinedOutput(); err != nil {
+		return fmt.Errorf("error running launchctl load %s: %v, %s", sysPlist, err, out)
+	}
+
+	if out, err := exec.Command("launchctl", "start", service).CombinedOutput(); err != nil {
+		return fmt.Errorf("error running launchctl start %s: %v, %s", service, err, out)
+	}
+
+	return nil
+}

cmd/tailscaled/tailscaled.go

@@ -11,9 +11,11 @@ package main // import "tailscale.com/cmd/tailscaled"
 
 import (
 	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"log"
+	"net"
 	"net/http"
 	"net/http/pprof"
 	"os"
@@ -21,18 +23,26 @@ import (
 	"runtime"
 	"runtime/debug"
 	"strconv"
+	"strings"
+	"sync"
 	"syscall"
 	"time"
 
-	"github.com/apenwarr/fixconsole"
+	"github.com/go-multierror/multierror"
 	"tailscale.com/ipn/ipnserver"
 	"tailscale.com/logpolicy"
+	"tailscale.com/net/socks5"
+	"tailscale.com/net/tstun"
 	"tailscale.com/paths"
 	"tailscale.com/types/flagtype"
 	"tailscale.com/types/logger"
+	"tailscale.com/types/netmap"
 	"tailscale.com/version"
+	"tailscale.com/version/distro"
 	"tailscale.com/wgengine"
 	"tailscale.com/wgengine/magicsock"
+	"tailscale.com/wgengine/monitor"
+	"tailscale.com/wgengine/netstack"
 	"tailscale.com/wgengine/router"
 )
 
@@ -52,18 +62,40 @@ func defaultTunName() string {
 		return "tun"
 	case "windows":
 		return "Tailscale"
+	case "darwin":
+		// "utun" is recognized by wireguard-go/tun/tun_darwin.go
+		// as a magic value that uses/creates any free number.
+		return "utun"
+	case "linux":
+		if distro.Get() == distro.Synology {
+			// Try TUN, but fall back to userspace networking if needed.
+			// See https://github.com/tailscale/tailscale-synology/issues/35
+			return "tailscale0,userspace-networking"
+		}
 	}
 	return "tailscale0"
 }
 
 var args struct {
 	cleanup    bool
-	fake       bool
 	debug      string
-	tunname    string
+	tunname    string // tun name, "userspace-networking", or comma-separated list thereof
 	port       uint16
 	statepath  string
 	socketpath string
+	verbose    int
+	socksAddr  string // listen address for SOCKS5 server
+}
+
+var (
+	installSystemDaemon   func([]string) error // non-nil on some platforms
+	uninstallSystemDaemon func([]string) error // non-nil on some platforms
+)
+
+var subCommands = map[string]*func([]string) error{
+	"install-system-daemon":   &installSystemDaemon,
+	"uninstall-system-daemon": &uninstallSystemDaemon,
+	"debug":                   &debugModeFunc,
 }
 
 func main() {
@@ -76,18 +108,33 @@ func main() {
 	}
 
 	printVersion := false
+	flag.IntVar(&args.verbose, "verbose", 0, "log verbosity level; 0 is default, 1 or higher are increasingly verbose")
 	flag.BoolVar(&args.cleanup, "cleanup", false, "clean up system state and exit")
-	flag.BoolVar(&args.fake, "fake", false, "use userspace fake tunnel+routing instead of kernel TUN interface")
 	flag.StringVar(&args.debug, "debug", "", "listen address ([ip]:port) of optional debug server")
-	flag.StringVar(&args.tunname, "tun", defaultTunName(), "tunnel interface name")
+	flag.StringVar(&args.socksAddr, "socks5-server", "", `optional [ip]:port to run a SOCK5 server (e.g. "localhost:1080")`)
+	flag.StringVar(&args.tunname, "tun", defaultTunName(), `tunnel interface name; use "userspace-networking" (beta) to not use TUN`)
 	flag.Var(flagtype.PortValue(&args.port, magicsock.DefaultPort), "port", "UDP port to listen on for WireGuard and peer-to-peer traffic; 0 means automatically select")
 	flag.StringVar(&args.statepath, "state", paths.DefaultTailscaledStateFile(), "path of state file")
 	flag.StringVar(&args.socketpath, "socket", paths.DefaultTailscaledSocket(), "path of the service unix socket")
 	flag.BoolVar(&printVersion, "version", false, "print version information and exit")
 
-	err := fixconsole.FixConsoleIfNeeded()
-	if err != nil {
-		log.Fatalf("fixConsoleOutput: %v", err)
+	if len(os.Args) > 1 {
+		sub := os.Args[1]
+		if fp, ok := subCommands[sub]; ok {
+			if *fp == nil {
+				log.SetFlags(0)
+				log.Fatalf("%s not available on %v", sub, runtime.GOOS)
+			}
+			if err := (*fp)(os.Args[2:]); err != nil {
+				log.SetFlags(0)
+				log.Fatal(err)
+			}
+			return
+		}
+	}
+
+	if beWindowsSubprocess() {
+		return
 	}
 
 	flag.Parse()
@@ -100,11 +147,13 @@ func main() {
 		os.Exit(0)
 	}
 
-	if args.statepath == "" {
-		log.Fatalf("--state is required")
+	if runtime.GOOS == "darwin" && os.Getuid() != 0 && !strings.Contains(args.tunname, "userspace-networking") {
+		log.SetFlags(0)
+		log.Fatalf("tailscaled requires root; use sudo tailscaled (or use --tun=userspace-networking)")
 	}
 
 	if args.socketpath == "" && runtime.GOOS != "windows" {
+		log.SetFlags(0)
 		log.Fatalf("--socket is required")
 	}
 
@@ -118,6 +167,7 @@ func run() error {
 	var err error
 
 	pol := logpolicy.New("tailnode.log.tailscale.io")
+	pol.SetVerbosityLevel(args.verbose)
 	defer func() {
 		// Finish uploading logs after closing everything else.
 		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
@@ -125,6 +175,16 @@ func run() error {
 		pol.Shutdown(ctx)
 	}()
 
+	if isWindowsService() {
+		// Run the IPN server from the Windows service manager.
+		log.Printf("Running service...")
+		if err := runWindowsService(pol); err != nil {
+			log.Printf("runservice: %v", err)
+		}
+		log.Printf("Service ended.")
+		return nil
+	}
+
 	var logf logger.Logf = log.Printf
 	if v, _ := strconv.ParseBool(os.Getenv("TS_DEBUG_MEMORY")); v {
 		logf = logger.RusagePrefixLog(logf)
@@ -136,22 +196,82 @@ func run() error {
 		return nil
 	}
 
+	if args.statepath == "" {
+		log.Fatalf("--state is required")
+	}
+
 	var debugMux *http.ServeMux
 	if args.debug != "" {
 		debugMux = newDebugMux()
 		go runDebugServer(debugMux, args.debug)
 	}
 
-	var e wgengine.Engine
-	if args.fake {
-		e, err = wgengine.NewFakeUserspaceEngine(logf, args.port)
-	} else {
-		e, err = wgengine.NewUserspaceEngine(logf, args.tunname, args.port)
+	linkMon, err := monitor.New(logf)
+	if err != nil {
+		log.Fatalf("creating link monitor: %v", err)
 	}
+	pol.Logtail.SetLinkMonitor(linkMon)
+
+	var socksListener net.Listener
+	if args.socksAddr != "" {
+		var err error
+		socksListener, err = net.Listen("tcp", args.socksAddr)
+		if err != nil {
+			log.Fatalf("SOCKS5 listener: %v", err)
+		}
+	}
+
+	e, useNetstack, err := createEngine(logf, linkMon)
 	if err != nil {
 		logf("wgengine.New: %v", err)
 		return err
 	}
+
+	var ns *netstack.Impl
+	if useNetstack {
+		tunDev, magicConn, ok := e.(wgengine.InternalsGetter).GetInternals()
+		if !ok {
+			log.Fatalf("%T is not a wgengine.InternalsGetter", e)
+		}
+		ns, err = netstack.Create(logf, tunDev, e, magicConn)
+		if err != nil {
+			log.Fatalf("netstack.Create: %v", err)
+		}
+		if err := ns.Start(); err != nil {
+			log.Fatalf("failed to start netstack: %v", err)
+		}
+	}
+
+	if socksListener != nil {
+		srv := &socks5.Server{
+			Logf: logger.WithPrefix(logf, "socks5: "),
+		}
+		if useNetstack {
+			srv.Dialer = func(ctx context.Context, network, addr string) (net.Conn, error) {
+				return ns.DialContextTCP(ctx, addr)
+			}
+		} else {
+			var mu sync.Mutex
+			var dns netstack.DNSMap
+			e.AddNetworkMapCallback(func(nm *netmap.NetworkMap) {
+				mu.Lock()
+				defer mu.Unlock()
+				dns = netstack.DNSMapFromNetworkMap(nm)
+			})
+			srv.Dialer = func(ctx context.Context, network, addr string) (net.Conn, error) {
+				ipp, err := dns.Resolve(ctx, addr)
+				if err != nil {
+					return nil, err
+				}
+				var d net.Dialer
+				return d.DialContext(ctx, network, ipp.String())
+			}
+		}
+		go func() {
+			log.Fatalf("SOCKS5 server exited: %v", srv.Serve(socksListener))
+		}()
+	}
+
 	e = wgengine.NewWatchdog(e)
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -192,6 +312,50 @@ func run() error {
 	return nil
 }
 
+func createEngine(logf logger.Logf, linkMon *monitor.Mon) (e wgengine.Engine, isUserspace bool, err error) {
+	if args.tunname == "" {
+		return nil, false, errors.New("no --tun value specified")
+	}
+	var errs []error
+	for _, name := range strings.Split(args.tunname, ",") {
+		logf("wgengine.NewUserspaceEngine(tun %q) ...", name)
+		e, isUserspace, err = tryEngine(logf, linkMon, name)
+		if err == nil {
+			return e, isUserspace, nil
+		}
+		logf("wgengine.NewUserspaceEngine(tun %q) error: %v", name, err)
+		errs = append(errs, err)
+	}
+	return nil, false, multierror.New(errs)
+}
+
+func tryEngine(logf logger.Logf, linkMon *monitor.Mon, name string) (e wgengine.Engine, isUserspace bool, err error) {
+	conf := wgengine.Config{
+		ListenPort:  args.port,
+		LinkMonitor: linkMon,
+	}
+	isUserspace = name == "userspace-networking"
+	if !isUserspace {
+		dev, err := tstun.New(logf, name)
+		if err != nil {
+			tstun.Diagnose(logf, name)
+			return nil, false, err
+		}
+		conf.Tun = dev
+		r, err := router.New(logf, dev)
+		if err != nil {
+			dev.Close()
+			return nil, false, err
+		}
+		conf.Router = r
+	}
+	e, err = wgengine.NewUserspaceEngine(logf, conf)
+	if err != nil {
+		return nil, isUserspace, err
+	}
+	return e, isUserspace, nil
+}
+
 func newDebugMux() *http.ServeMux {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/debug/pprof/", pprof.Index)

cmd/tailscaled/tailscaled.service

@@ -6,6 +6,7 @@ After=network-pre.target
 
 [Service]
 EnvironmentFile=/etc/default/tailscaled
+ExecStartPre=/usr/sbin/tailscaled --cleanup
 ExecStart=/usr/sbin/tailscaled --state=/var/lib/tailscale/tailscaled.state --socket=/run/tailscale/tailscaled.sock --port $PORT $FLAGS
 ExecStopPost=/usr/sbin/tailscaled --cleanup
 
@@ -17,6 +18,7 @@ StateDirectory=tailscale
 StateDirectoryMode=0750
 CacheDirectory=tailscale
 CacheDirectoryMode=0750
+Type=notify
 
 [Install]
 WantedBy=multi-user.target

cmd/tailscaled/tailscaled_notwindows.go

@@ -0,0 +1,15 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows
+
+package main // import "tailscale.com/cmd/tailscaled"
+
+import "tailscale.com/logpolicy"
+
+func isWindowsService() bool { return false }
+
+func runWindowsService(pol *logpolicy.Policy) error { panic("unreachable") }
+
+func beWindowsSubprocess() bool { return false }

cmd/tailscaled/tailscaled_windows.go

@@ -0,0 +1,242 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main // import "tailscale.com/cmd/tailscaled"
+
+// TODO: check if administrator, like tswin does.
+//
+// TODO: try to load wintun.dll early at startup, before wireguard/tun
+//       does (which panics) and if we'd fail (e.g. due to access
+//       denied, even if administrator), use 'tasklist /m wintun.dll'
+//       to see if something else is currently using it and tell user.
+//
+// TODO: check if Tailscale service is already running, and fail early
+//       like tswin does.
+//
+// TODO: on failure, check if on a UNC drive and recommend copying it
+//       to C:\ to run it, like tswin does.
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"time"
+
+	"golang.org/x/sys/windows"
+	"golang.org/x/sys/windows/svc"
+	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
+	"tailscale.com/ipn/ipnserver"
+	"tailscale.com/logpolicy"
+	"tailscale.com/net/tstun"
+	"tailscale.com/tempfork/wireguard-windows/firewall"
+	"tailscale.com/types/logger"
+	"tailscale.com/version"
+	"tailscale.com/wgengine"
+	"tailscale.com/wgengine/router"
+)
+
+const serviceName = "Tailscale"
+
+func isWindowsService() bool {
+	v, err := svc.IsWindowsService()
+	if err != nil {
+		log.Fatalf("svc.IsWindowsService failed: %v", err)
+	}
+	return v
+}
+
+func runWindowsService(pol *logpolicy.Policy) error {
+	return svc.Run(serviceName, &ipnService{Policy: pol})
+}
+
+type ipnService struct {
+	Policy *logpolicy.Policy
+}
+
+// Called by Windows to execute the windows service.
+func (service *ipnService) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (bool, uint32) {
+	changes <- svc.Status{State: svc.StartPending}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	doneCh := make(chan struct{})
+	go func() {
+		defer close(doneCh)
+		args := []string{"/subproc", service.Policy.PublicID.String()}
+		ipnserver.BabysitProc(ctx, args, log.Printf)
+	}()
+
+	changes <- svc.Status{State: svc.Running, Accepts: svc.AcceptStop}
+
+	for ctx.Err() == nil {
+		select {
+		case <-doneCh:
+		case cmd := <-r:
+			switch cmd.Cmd {
+			case svc.Stop:
+				cancel()
+			case svc.Interrogate:
+				changes <- cmd.CurrentStatus
+			}
+		}
+	}
+
+	changes <- svc.Status{State: svc.StopPending}
+	return false, windows.NO_ERROR
+}
+
+func beWindowsSubprocess() bool {
+	if beFirewallKillswitch() {
+		return true
+	}
+
+	if len(os.Args) != 3 || os.Args[1] != "/subproc" {
+		return false
+	}
+	logid := os.Args[2]
+
+	log.Printf("Program starting: v%v: %#v", version.Long, os.Args)
+	log.Printf("subproc mode: logid=%v", logid)
+
+	go func() {
+		b := make([]byte, 16)
+		for {
+			_, err := os.Stdin.Read(b)
+			if err != nil {
+				log.Fatalf("stdin err (parent process died): %v", err)
+			}
+		}
+	}()
+
+	err := startIPNServer(context.Background(), logid)
+	if err != nil {
+		log.Fatalf("ipnserver: %v", err)
+	}
+	return true
+}
+
+func beFirewallKillswitch() bool {
+	if len(os.Args) != 3 || os.Args[1] != "/firewall" {
+		return false
+	}
+
+	log.SetFlags(0)
+	log.Printf("killswitch subprocess starting, tailscale GUID is %s", os.Args[2])
+
+	go func() {
+		b := make([]byte, 16)
+		for {
+			_, err := os.Stdin.Read(b)
+			if err != nil {
+				log.Fatalf("parent process died or requested exit, exiting (%v)", err)
+			}
+		}
+	}()
+
+	guid, err := windows.GUIDFromString(os.Args[2])
+	if err != nil {
+		log.Fatalf("invalid GUID %q: %v", os.Args[2], err)
+	}
+
+	luid, err := winipcfg.LUIDFromGUID(&guid)
+	if err != nil {
+		log.Fatalf("no interface with GUID %q", guid)
+	}
+
+	noProtection := false
+	var dnsIPs []net.IP // unused in called code.
+	start := time.Now()
+	firewall.EnableFirewall(uint64(luid), noProtection, dnsIPs)
+	log.Printf("killswitch enabled, took %s", time.Since(start))
+
+	// Block until the monitor goroutine shuts us down.
+	select {}
+}
+
+func startIPNServer(ctx context.Context, logid string) error {
+	var logf logger.Logf = log.Printf
+	var eng wgengine.Engine
+	var err error
+
+	getEngine := func() (wgengine.Engine, error) {
+		dev, err := tstun.New(logf, "Tailscale")
+		if err != nil {
+			return nil, err
+		}
+		r, err := router.New(logf, dev)
+		if err != nil {
+			dev.Close()
+			return nil, err
+		}
+		eng, err := wgengine.NewUserspaceEngine(logf, wgengine.Config{
+			Tun:        dev,
+			Router:     r,
+			ListenPort: 41641,
+		})
+		if err != nil {
+			r.Close()
+			dev.Close()
+			return nil, err
+		}
+		return wgengine.NewWatchdog(eng), nil
+	}
+
+	if msg := os.Getenv("TS_DEBUG_WIN_FAIL"); msg != "" {
+		err = fmt.Errorf("pretending to be a service failure: %v", msg)
+	} else {
+		// We have a bunch of bug reports of wgengine.NewUserspaceEngine returning a few different errors,
+		// all intermittently. A few times I (Brad) have also seen sporadic failures that simply
+		// restarting fixed. So try a few times.
+		for try := 1; try <= 5; try++ {
+			if try > 1 {
+				// Only sleep a bit. Don't do some massive backoff because
+				// the frontend GUI has a 30 second timeout on connecting to us,
+				// but even 5 seconds is too long for them to get any results.
+				// 5 tries * 1 second each seems fine.
+				time.Sleep(time.Second)
+			}
+			eng, err = getEngine()
+			if err != nil {
+				logf("wgengine.NewUserspaceEngine: (try %v) %v", try, err)
+				continue
+			}
+			if try > 1 {
+				logf("wgengine.NewUserspaceEngine: ended up working on try %v", try)
+			}
+			break
+		}
+	}
+	if err != nil {
+		// Log the error, but don't fatalf. We want to
+		// propagate the error message to the UI frontend. So
+		// we continue and tell the ipnserver to return that
+		// in a Notify message.
+		logf("wgengine.NewUserspaceEngine: %v", err)
+	}
+	opts := ipnserver.Options{
+		Port:               41112,
+		SurviveDisconnects: false,
+		StatePath:          args.statepath,
+	}
+	if err != nil {
+		// Return nicer errors to users, annotated with logids, which helps
+		// when they file bugs.
+		rawGetEngine := getEngine // raw == without verbose logid-containing error
+		getEngine = func() (wgengine.Engine, error) {
+			eng, err := rawGetEngine()
+			if err != nil {
+				return nil, fmt.Errorf("wgengine.NewUserspaceEngine: %v\n\nlogid: %v", err, logid)
+			}
+			return eng, nil
+		}
+	} else {
+		getEngine = ipnserver.FixedEngine(eng)
+	}
+	err = ipnserver.Run(ctx, logf, logid, getEngine, opts)
+	if err != nil {
+		logf("ipnserver.Run: %v", err)
+	}
+	return err
+}

cmd/tsshd/tsshd.go

@@ -32,7 +32,9 @@ import (
 	"github.com/gliderlabs/ssh"
 	"github.com/kr/pty"
 	gossh "golang.org/x/crypto/ssh"
+	"inet.af/netaddr"
 	"tailscale.com/net/interfaces"
+	"tailscale.com/net/tsaddr"
 )
 
 var (
@@ -96,7 +98,13 @@ func handleSSH(s ssh.Session) {
 		s.Exit(1)
 		return
 	}
-	if !interfaces.IsTailscaleIP(ta.IP) {
+	tanetaddr, ok := netaddr.FromStdIP(ta.IP)
+	if !ok {
+		log.Printf("tsshd: rejecting unparseable addr %v", ta.IP)
+		s.Exit(1)
+		return
+	}
+	if !tsaddr.IsTailscaleIP(tanetaddr) {
 		log.Printf("tsshd: rejecting non-Tailscale addr %v", ta.IP)
 		s.Exit(1)
 		return

control/controlclient/auto.go

@@ -17,13 +17,15 @@ import (
 	"sync"
 	"time"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
-	"golang.org/x/oauth2"
+	"tailscale.com/health"
 	"tailscale.com/logtail/backoff"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/empty"
 	"tailscale.com/types/logger"
+	"tailscale.com/types/netmap"
+	"tailscale.com/types/persist"
 	"tailscale.com/types/structs"
+	"tailscale.com/types/wgkey"
 )
 
 // State is the high-level state of the client. It is used only in
@@ -68,9 +70,9 @@ type Status struct {
 	LoginFinished *empty.Message
 	Err           string
 	URL           string
-	Persist       *Persist          // locally persisted configuration
-	NetMap        *NetworkMap       // server-pushed configuration
-	Hostinfo      *tailcfg.Hostinfo // current Hostinfo data
+	Persist       *persist.Persist   // locally persisted configuration
+	NetMap        *netmap.NetworkMap // server-pushed configuration
+	Hostinfo      *tailcfg.Hostinfo  // current Hostinfo data
 	State         State
 }
 
@@ -99,10 +101,10 @@ func (s Status) String() string {
 
 type LoginGoal struct {
 	_            structs.Incomparable
-	wantLoggedIn bool          // true if we *want* to be logged in
-	token        *oauth2.Token // oauth token to use when logging in
-	flags        LoginFlags    // flags to use when logging in
-	url          string        // auth url that needs to be visited
+	wantLoggedIn bool                 // true if we *want* to be logged in
+	token        *tailcfg.Oauth2Token // oauth token to use when logging in
+	flags        LoginFlags           // flags to use when logging in
+	url          string               // auth url that needs to be visited
 }
 
 // Client connects to a tailcontrol server for a node.
@@ -114,18 +116,21 @@ type Client struct {
 	closed   bool
 	newMapCh chan struct{} // readable when we must restart a map request
 
+	unregisterHealthWatch func()
+
 	mu         sync.Mutex   // mutex guards the following fields
 	statusFunc func(Status) // called to update Client status
 
-	paused         bool // whether we should stop making HTTP requests
-	unpauseWaiters []chan struct{}
-	loggedIn       bool       // true if currently logged in
-	loginGoal      *LoginGoal // non-nil if some login activity is desired
-	synced         bool       // true if our netmap is up-to-date
-	hostinfo       *tailcfg.Hostinfo
-	inPollNetMap   bool // true if currently running a PollNetMap
-	inSendStatus   int  // number of sendStatus calls currently in progress
-	state          State
+	paused          bool // whether we should stop making HTTP requests
+	unpauseWaiters  []chan struct{}
+	loggedIn        bool       // true if currently logged in
+	loginGoal       *LoginGoal // non-nil if some login activity is desired
+	synced          bool       // true if our netmap is up-to-date
+	hostinfo        *tailcfg.Hostinfo
+	inPollNetMap    bool // true if currently running a PollNetMap
+	inLiteMapUpdate bool // true if a lite (non-streaming) map request is outstanding
+	inSendStatus    int  // number of sendStatus calls currently in progress
+	state           State
 
 	authCtx    context.Context // context used for auth requests
 	mapCtx     context.Context // context used for netmap requests
@@ -168,7 +173,17 @@ func NewNoStart(opts Options) (*Client, error) {
 	}
 	c.authCtx, c.authCancel = context.WithCancel(context.Background())
 	c.mapCtx, c.mapCancel = context.WithCancel(context.Background())
+	c.unregisterHealthWatch = health.RegisterWatcher(c.onHealthChange)
 	return c, nil
+
+}
+
+func (c *Client) onHealthChange(sys health.Subsystem, err error) {
+	if sys == health.SysOverall {
+		return
+	}
+	c.logf("controlclient: restarting map request for %q health change to new state: %v", sys, err)
+	c.cancelMapSafely()
 }
 
 // SetPaused controls whether HTTP activity should be paused.
@@ -182,7 +197,8 @@ func (c *Client) SetPaused(paused bool) {
 	}
 	c.paused = paused
 	if paused {
-		// Just cancel the map routine. The auth routine isn't expensive.
+		// Only cancel the map routine. (The auth routine isn't expensive
+		// so it's fine to keep it running.)
 		c.cancelMapLocked()
 	} else {
 		for _, ch := range c.unpauseWaiters {
@@ -200,6 +216,50 @@ func (c *Client) Start() {
 	go c.mapRoutine()
 }
 
+// sendNewMapRequest either sends a new OmitPeers, non-streaming map request
+// (to just send Hostinfo/Netinfo/Endpoints info, while keeping an existing
+// streaming response open), or start a new streaming one if necessary.
+//
+// It should be called whenever there's something new to tell the server.
+func (c *Client) sendNewMapRequest() {
+	c.mu.Lock()
+
+	// If we're not already streaming a netmap, or if we're already stuck
+	// in a lite update, then tear down everything and start a new stream
+	// (which starts by sending a new map request)
+	if !c.inPollNetMap || c.inLiteMapUpdate || !c.loggedIn {
+		c.mu.Unlock()
+		c.cancelMapSafely()
+		return
+	}
+
+	// Otherwise, send a lite update that doesn't keep a
+	// long-running stream response.
+	defer c.mu.Unlock()
+	c.inLiteMapUpdate = true
+	ctx, cancel := context.WithTimeout(c.mapCtx, 10*time.Second)
+	go func() {
+		defer cancel()
+		t0 := time.Now()
+		err := c.direct.SendLiteMapUpdate(ctx)
+		d := time.Since(t0).Round(time.Millisecond)
+		c.mu.Lock()
+		c.inLiteMapUpdate = false
+		c.mu.Unlock()
+		if err == nil {
+			c.logf("[v1] successful lite map update in %v", d)
+			return
+		}
+		if ctx.Err() == nil {
+			c.logf("lite map update after %v: %v", d, err)
+		}
+		// Fall back to restarting the long-polling map
+		// request (the old heavy way) if the lite update
+		// failed for any reason.
+		c.cancelMapSafely()
+	}()
+}
+
 func (c *Client) cancelAuth() {
 	c.mu.Lock()
 	if c.authCancel != nil {
@@ -230,7 +290,7 @@ func (c *Client) cancelMapSafely() {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	c.logf("cancelMapSafely: synced=%v", c.synced)
+	c.logf("[v1] cancelMapSafely: synced=%v", c.synced)
 
 	if c.inPollNetMap {
 		// received at least one netmap since the last
@@ -252,12 +312,12 @@ func (c *Client) cancelMapSafely() {
 		// request.
 		select {
 		case c.newMapCh <- struct{}{}:
-			c.logf("cancelMapSafely: wrote to channel")
+			c.logf("[v1] cancelMapSafely: wrote to channel")
 		default:
 			// if channel write failed, then there was already
 			// an outstanding newMapCh request. One is enough,
 			// since it'll always use the latest endpoints.
-			c.logf("cancelMapSafely: channel was full")
+			c.logf("[v1] cancelMapSafely: channel was full")
 		}
 	}
 }
@@ -268,22 +328,24 @@ func (c *Client) authRoutine() {
 
 	for {
 		c.mu.Lock()
-		c.logf("authRoutine: %s", c.state)
-		expiry := c.expiry
 		goal := c.loginGoal
 		ctx := c.authCtx
-		synced := c.synced
+		if goal != nil {
+			c.logf("authRoutine: %s; wantLoggedIn=%v", c.state, goal.wantLoggedIn)
+		} else {
+			c.logf("authRoutine: %s; goal=nil", c.state)
+		}
 		c.mu.Unlock()
 
 		select {
 		case <-c.quit:
-			c.logf("authRoutine: quit")
+			c.logf("[v1] authRoutine: quit")
 			return
 		default:
 		}
 
 		report := func(err error, msg string) {
-			c.logf("%s: %v", msg, err)
+			c.logf("[v1] %s: %v", msg, err)
 			err = fmt.Errorf("%s: %v", msg, err)
 			// don't send status updates for context errors,
 			// since context cancelation is always on purpose.
@@ -293,51 +355,13 @@ func (c *Client) authRoutine() {
 		}
 
 		if goal == nil {
-			// Wait for something interesting to happen
-			var exp <-chan time.Time
-			var expTimer *time.Timer
-			if expiry != nil && !expiry.IsZero() {
-				// if expiry is in the future, don't delay
-				// past that time.
-				// If it's in the past, then it's already
-				// being handled by someone, so no need to
-				// wake ourselves up again.
-				now := c.timeNow()
-				if expiry.Before(now) {
-					delay := expiry.Sub(now)
-					if delay > 5*time.Second {
-						delay = time.Second
-					}
-					expTimer = time.NewTimer(delay)
-					exp = expTimer.C
-				}
-			}
-			select {
-			case <-ctx.Done():
-				if expTimer != nil {
-					expTimer.Stop()
-				}
-				c.logf("authRoutine: context done.")
-			case <-exp:
-				// Unfortunately the key expiry isn't provided
-				// by the control server until mapRequest.
-				// So we have to do some hackery with c.expiry
-				// in here.
-				// TODO(apenwarr): add a key expiry field in RegisterResponse.
-				c.logf("authRoutine: key expiration check.")
-				if synced && expiry != nil && !expiry.IsZero() && expiry.Before(c.timeNow()) {
-					c.logf("Key expired; setting loggedIn=false.")
+			// Wait for user to Login or Logout.
+			<-ctx.Done()
+			c.logf("[v1] authRoutine: context done.")
+			continue
+		}
 
-					c.mu.Lock()
-					c.loginGoal = &LoginGoal{
-						wantLoggedIn: c.loggedIn,
-					}
-					c.loggedIn = false
-					c.expiry = nil
-					c.mu.Unlock()
-				}
-			}
-		} else if !goal.wantLoggedIn {
+		if !goal.wantLoggedIn {
 			err := c.direct.TryLogout(ctx)
 			if err != nil {
 				report(err, "TryLogout")
@@ -469,7 +493,7 @@ func (c *Client) mapRoutine() {
 		}
 
 		report := func(err error, msg string) {
-			c.logf("%s: %v", msg, err)
+			c.logf("[v1] %s: %v", msg, err)
 			err = fmt.Errorf("%s: %v", msg, err)
 			// don't send status updates for context errors,
 			// since context cancelation is always on purpose.
@@ -498,13 +522,15 @@ func (c *Client) mapRoutine() {
 			c.mu.Lock()
 			c.inPollNetMap = false
 			c.mu.Unlock()
+			health.SetInPollNetMap(false)
 
-			err := c.direct.PollNetMap(ctx, -1, func(nm *NetworkMap) {
+			err := c.direct.PollNetMap(ctx, -1, func(nm *netmap.NetworkMap) {
+				health.SetInPollNetMap(true)
 				c.mu.Lock()
 
 				select {
 				case <-c.newMapCh:
-					c.logf("mapRoutine: new map request during PollNetMap. canceling.")
+					c.logf("[v1] mapRoutine: new map request during PollNetMap. canceling.")
 					c.cancelMapLocked()
 
 					// Don't emit this netmap; we're
@@ -526,12 +552,13 @@ func (c *Client) mapRoutine() {
 
 				c.mu.Unlock()
 
-				c.logf("mapRoutine: netmap received: %s", state)
+				c.logf("[v1] mapRoutine: netmap received: %s", state)
 				if stillAuthed {
 					c.sendStatus("mapRoutine-got-netmap", nil, "", nm)
 				}
 			})
 
+			health.SetInPollNetMap(false)
 			c.mu.Lock()
 			c.synced = false
 			c.inPollNetMap = false
@@ -577,10 +604,9 @@ func (c *Client) SetHostinfo(hi *tailcfg.Hostinfo) {
 		// No changes. Don't log.
 		return
 	}
-	c.logf("Hostinfo: %v", hi)
 
 	// Send new Hostinfo to server
-	c.cancelMapSafely()
+	c.sendNewMapRequest()
 }
 
 func (c *Client) SetNetInfo(ni *tailcfg.NetInfo) {
@@ -588,16 +614,15 @@ func (c *Client) SetNetInfo(ni *tailcfg.NetInfo) {
 		panic("nil NetInfo")
 	}
 	if !c.direct.SetNetInfo(ni) {
-		c.logf("[unexpected] duplicate NetInfo: %v", ni)
 		return
 	}
 	c.logf("NetInfo: %v", ni)
 
 	// Send new Hostinfo (which includes NetInfo) to server
-	c.cancelMapSafely()
+	c.sendNewMapRequest()
 }
 
-func (c *Client) sendStatus(who string, err error, url string, nm *NetworkMap) {
+func (c *Client) sendStatus(who string, err error, url string, nm *netmap.NetworkMap) {
 	c.mu.Lock()
 	state := c.state
 	loggedIn := c.loggedIn
@@ -607,9 +632,9 @@ func (c *Client) sendStatus(who string, err error, url string, nm *NetworkMap) {
 	c.inSendStatus++
 	c.mu.Unlock()
 
-	c.logf("sendStatus: %s: %v", who, state)
+	c.logf("[v1] sendStatus: %s: %v", who, state)
 
-	var p *Persist
+	var p *persist.Persist
 	var fin *empty.Message
 	if state == StateAuthenticated {
 		fin = new(empty.Message)
@@ -642,7 +667,7 @@ func (c *Client) sendStatus(who string, err error, url string, nm *NetworkMap) {
 	c.mu.Unlock()
 }
 
-func (c *Client) Login(t *oauth2.Token, flags LoginFlags) {
+func (c *Client) Login(t *tailcfg.Oauth2Token, flags LoginFlags) {
 	c.logf("client.Login(%v, %v)", t != nil, flags)
 
 	c.mu.Lock()
@@ -671,7 +696,7 @@ func (c *Client) Logout() {
 func (c *Client) UpdateEndpoints(localPort uint16, endpoints []string) {
 	changed := c.direct.SetEndpoints(localPort, endpoints)
 	if changed {
-		c.cancelMapSafely()
+		c.sendNewMapRequest()
 	}
 }
 
@@ -689,6 +714,7 @@ func (c *Client) Shutdown() {
 
 	c.logf("client.Shutdown: inSendStatus=%v", inSendStatus)
 	if !closed {
+		c.unregisterHealthWatch()
 		close(c.quit)
 		c.cancelAuth()
 		<-c.authDone
@@ -700,7 +726,7 @@ func (c *Client) Shutdown() {
 
 // NodePublicKey returns the node public key currently in use. This is
 // used exclusively in tests.
-func (c *Client) TestOnlyNodePublicKey() wgcfg.Key {
+func (c *Client) TestOnlyNodePublicKey() wgkey.Key {
 	priv := c.direct.GetPersist()
 	return priv.PrivateNodeKey.Public()
 }

control/controlclient/controlclient_test.go

@@ -42,6 +42,11 @@ func TestStatusEqual(t *testing.T) {
 			&Status{},
 			false,
 		},
+		{
+			nil,
+			nil,
+			true,
+		},
 		{
 			&Status{},
 			&Status{},

control/controlclient/debug.go

@@ -0,0 +1,69 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package controlclient
+
+import (
+	"bytes"
+	"compress/gzip"
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+	"regexp"
+	"runtime"
+	"strconv"
+	"time"
+)
+
+func dumpGoroutinesToURL(c *http.Client, targetURL string) {
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	zbuf := new(bytes.Buffer)
+	zw := gzip.NewWriter(zbuf)
+	zw.Write(scrubbedGoroutineDump())
+	zw.Close()
+
+	req, err := http.NewRequestWithContext(ctx, "PUT", targetURL, zbuf)
+	if err != nil {
+		log.Printf("dumpGoroutinesToURL: %v", err)
+		return
+	}
+	req.Header.Set("Content-Encoding", "gzip")
+	t0 := time.Now()
+	_, err = c.Do(req)
+	d := time.Since(t0).Round(time.Millisecond)
+	if err != nil {
+		log.Printf("dumpGoroutinesToURL error: %v to %v (after %v)", err, targetURL, d)
+	} else {
+		log.Printf("dumpGoroutinesToURL complete to %v (after %v)", targetURL, d)
+	}
+}
+
+var reHexArgs = regexp.MustCompile(`\b0x[0-9a-f]+\b`)
+
+// scrubbedGoroutineDump returns the list of all current goroutines, but with the actual
+// values of arguments scrubbed out, lest it contain some private key material.
+func scrubbedGoroutineDump() []byte {
+	buf := make([]byte, 1<<20)
+	buf = buf[:runtime.Stack(buf, true)]
+
+	saw := map[string][]byte{} // "0x123" => "v1%3" (unique value 1 and its value mod 8)
+	return reHexArgs.ReplaceAllFunc(buf, func(in []byte) []byte {
+		if string(in) == "0x0" {
+			return in
+		}
+		if v, ok := saw[string(in)]; ok {
+			return v
+		}
+		u64, err := strconv.ParseUint(string(in[2:]), 16, 64)
+		if err != nil {
+			return []byte("??")
+		}
+		v := []byte(fmt.Sprintf("v%d%%%d", len(saw)+1, u64%8))
+		saw[string(in)] = v
+		return v
+	})
+}

control/controlclient/debug_test.go

@@ -0,0 +1,11 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package controlclient
+
+import "testing"
+
+func TestScrubbedGoroutineDump(t *testing.T) {
+	t.Logf("Got:\n%s\n", scrubbedGoroutineDump())
+}

control/controlclient/direct.go

@@ -4,8 +4,6 @@
 
 package controlclient
 
-//go:generate go run tailscale.com/cmd/cloner -type=Persist -output=direct_clone.go
-
 import (
 	"bytes"
 	"context"
@@ -21,6 +19,8 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"os/exec"
+	"path/filepath"
 	"reflect"
 	"runtime"
 	"sort"
@@ -30,90 +30,48 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
 	"golang.org/x/crypto/nacl/box"
-	"golang.org/x/oauth2"
 	"inet.af/netaddr"
+	"tailscale.com/health"
 	"tailscale.com/log/logheap"
+	"tailscale.com/net/dnscache"
+	"tailscale.com/net/dnsfallback"
+	"tailscale.com/net/interfaces"
 	"tailscale.com/net/netns"
 	"tailscale.com/net/tlsdial"
 	"tailscale.com/net/tshttpproxy"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
+	"tailscale.com/types/netmap"
 	"tailscale.com/types/opt"
-	"tailscale.com/types/structs"
+	"tailscale.com/types/persist"
+	"tailscale.com/types/wgkey"
+	"tailscale.com/util/systemd"
 	"tailscale.com/version"
+	"tailscale.com/wgengine/filter"
+	"tailscale.com/wgengine/monitor"
 )
 
-type Persist struct {
-	_ structs.Incomparable
-
-	// LegacyFrontendPrivateMachineKey is here temporarily
-	// (starting 2020-09-28) during migration of Windows users'
-	// machine keys from frontend storage to the backend. On the
-	// first LocalBackend.Start call, the backend will initialize
-	// the real (backend-owned) machine key from the frontend's
-	// provided value (if non-zero), picking a new random one if
-	// needed. This field should be considered read-only from GUI
-	// frontends. The real value should not be written back in
-	// this field, lest the frontend persist it to disk.
-	LegacyFrontendPrivateMachineKey wgcfg.PrivateKey `json:"PrivateMachineKey"`
-
-	PrivateNodeKey    wgcfg.PrivateKey
-	OldPrivateNodeKey wgcfg.PrivateKey // needed to request key rotation
-	Provider          string
-	LoginName         string
-}
-
-func (p *Persist) Equals(p2 *Persist) bool {
-	if p == nil && p2 == nil {
-		return true
-	}
-	if p == nil || p2 == nil {
-		return false
-	}
-
-	return p.LegacyFrontendPrivateMachineKey.Equal(p2.LegacyFrontendPrivateMachineKey) &&
-		p.PrivateNodeKey.Equal(p2.PrivateNodeKey) &&
-		p.OldPrivateNodeKey.Equal(p2.OldPrivateNodeKey) &&
-		p.Provider == p2.Provider &&
-		p.LoginName == p2.LoginName
-}
-
-func (p *Persist) Pretty() string {
-	var mk, ok, nk wgcfg.Key
-	if !p.LegacyFrontendPrivateMachineKey.IsZero() {
-		mk = p.LegacyFrontendPrivateMachineKey.Public()
-	}
-	if !p.OldPrivateNodeKey.IsZero() {
-		ok = p.OldPrivateNodeKey.Public()
-	}
-	if !p.PrivateNodeKey.IsZero() {
-		nk = p.PrivateNodeKey.Public()
-	}
-	return fmt.Sprintf("Persist{lm=%v, o=%v, n=%v u=%#v}",
-		mk.ShortString(), ok.ShortString(), nk.ShortString(),
-		p.LoginName)
-}
-
 // Direct is the client that connects to a tailcontrol server for a node.
 type Direct struct {
-	httpc           *http.Client // HTTP client used to talk to tailcontrol
-	serverURL       string       // URL of the tailcontrol server
-	timeNow         func() time.Time
-	lastPrintMap    time.Time
-	newDecompressor func() (Decompressor, error)
-	keepAlive       bool
-	logf            logger.Logf
-	discoPubKey     tailcfg.DiscoKey
-	machinePrivKey  wgcfg.PrivateKey
-	debugFlags      []string
+	httpc                  *http.Client // HTTP client used to talk to tailcontrol
+	serverURL              string       // URL of the tailcontrol server
+	timeNow                func() time.Time
+	lastPrintMap           time.Time
+	newDecompressor        func() (Decompressor, error)
+	keepAlive              bool
+	logf                   logger.Logf
+	linkMon                *monitor.Mon // or nil
+	discoPubKey            tailcfg.DiscoKey
+	machinePrivKey         wgkey.Private
+	debugFlags             []string
+	keepSharerAndUserSplit bool
 
 	mu           sync.Mutex // mutex guards the following fields
-	serverKey    wgcfg.Key
-	persist      Persist
+	serverKey    wgkey.Key
+	persist      persist.Persist
 	authKey      string
-	tryingNewKey wgcfg.PrivateKey
+	tryingNewKey wgkey.Private
 	expiry       *time.Time
 	// hostinfo is mutated in-place while mu is held.
 	hostinfo      *tailcfg.Hostinfo // always non-nil
@@ -123,8 +81,8 @@ type Direct struct {
 }
 
 type Options struct {
-	Persist           Persist           // initial persistent data
-	MachinePrivateKey wgcfg.PrivateKey  // the machine key to use
+	Persist           persist.Persist   // initial persistent data
+	MachinePrivateKey wgkey.Private     // the machine key to use
 	ServerURL         string            // URL of the tailcontrol server
 	AuthKey           string            // optional node auth key for auto registration
 	TimeNow           func() time.Time  // time.Now implementation used by Client
@@ -135,6 +93,11 @@ type Options struct {
 	Logf              logger.Logf
 	HTTPTestClient    *http.Client // optional HTTP client to use (for tests only)
 	DebugFlags        []string     // debug settings to send to control
+	LinkMonitor       *monitor.Mon // optional link monitor
+
+	// KeepSharerAndUserSplit controls whether the client
+	// understands Node.Sharer. If false, the Sharer is mapped to the User.
+	KeepSharerAndUserSplit bool
 }
 
 type Decompressor interface {
@@ -166,28 +129,36 @@ func NewDirect(opts Options) (*Direct, error) {
 
 	httpc := opts.HTTPTestClient
 	if httpc == nil {
+		dnsCache := &dnscache.Resolver{
+			Forward:          dnscache.Get().Forward, // use default cache's forwarder
+			UseLastGood:      true,
+			LookupIPFallback: dnsfallback.Lookup,
+		}
 		dialer := netns.NewDialer()
 		tr := http.DefaultTransport.(*http.Transport).Clone()
 		tr.Proxy = tshttpproxy.ProxyFromEnvironment
 		tshttpproxy.SetTransportGetProxyConnectHeader(tr)
-		tr.DialContext = dialer.DialContext
-		tr.ForceAttemptHTTP2 = true
 		tr.TLSClientConfig = tlsdial.Config(serverURL.Host, tr.TLSClientConfig)
+		tr.DialContext = dnscache.Dialer(dialer.DialContext, dnsCache)
+		tr.DialTLSContext = dnscache.TLSDialer(dialer.DialContext, dnsCache, tr.TLSClientConfig)
+		tr.ForceAttemptHTTP2 = true
 		httpc = &http.Client{Transport: tr}
 	}
 
 	c := &Direct{
-		httpc:           httpc,
-		machinePrivKey:  opts.MachinePrivateKey,
-		serverURL:       opts.ServerURL,
-		timeNow:         opts.TimeNow,
-		logf:            opts.Logf,
-		newDecompressor: opts.NewDecompressor,
-		keepAlive:       opts.KeepAlive,
-		persist:         opts.Persist,
-		authKey:         opts.AuthKey,
-		discoPubKey:     opts.DiscoPublicKey,
-		debugFlags:      opts.DebugFlags,
+		httpc:                  httpc,
+		machinePrivKey:         opts.MachinePrivateKey,
+		serverURL:              opts.ServerURL,
+		timeNow:                opts.TimeNow,
+		logf:                   opts.Logf,
+		newDecompressor:        opts.NewDecompressor,
+		keepAlive:              opts.KeepAlive,
+		persist:                opts.Persist,
+		authKey:                opts.AuthKey,
+		discoPubKey:            opts.DiscoPublicKey,
+		debugFlags:             opts.DebugFlags,
+		keepSharerAndUserSplit: opts.KeepSharerAndUserSplit,
+		linkMon:                opts.LinkMonitor,
 	}
 	if opts.Hostinfo == nil {
 		c.SetHostinfo(NewHostinfo())
@@ -210,10 +181,25 @@ func NewHostinfo() *tailcfg.Hostinfo {
 		Hostname:   hostname,
 		OS:         version.OS(),
 		OSVersion:  osv,
+		Package:    packageType(),
 		GoArch:     runtime.GOARCH,
 	}
 }
 
+func packageType() string {
+	switch runtime.GOOS {
+	case "windows":
+		if _, err := os.Stat(`C:\ProgramData\chocolatey\lib\tailscale`); err == nil {
+			return "choco"
+		}
+	case "darwin":
+		// Using tailscaled or IPNExtension?
+		exe, _ := os.Executable()
+		return filepath.Base(exe)
+	}
+	return ""
+}
+
 // SetHostinfo clones the provided Hostinfo and remembers it for the
 // next update. It reports whether the Hostinfo has changed.
 func (c *Direct) SetHostinfo(hi *tailcfg.Hostinfo) bool {
@@ -252,7 +238,7 @@ func (c *Direct) SetNetInfo(ni *tailcfg.NetInfo) bool {
 	return true
 }
 
-func (c *Direct) GetPersist() Persist {
+func (c *Direct) GetPersist() persist.Persist {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	return c.persist
@@ -275,11 +261,11 @@ func (c *Direct) TryLogout(ctx context.Context) error {
 	// immediately invalidated.
 	//if !c.persist.PrivateNodeKey.IsZero() {
 	//}
-	c.persist = Persist{}
+	c.persist = persist.Persist{}
 	return nil
 }
 
-func (c *Direct) TryLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags) (url string, err error) {
+func (c *Direct) TryLogin(ctx context.Context, t *tailcfg.Oauth2Token, flags LoginFlags) (url string, err error) {
 	c.logf("direct.TryLogin(token=%v, flags=%v)", t != nil, flags)
 	return c.doLoginOrRegen(ctx, t, flags, false, "")
 }
@@ -289,7 +275,7 @@ func (c *Direct) WaitLoginURL(ctx context.Context, url string) (newUrl string, e
 	return c.doLoginOrRegen(ctx, nil, LoginDefault, false, url)
 }
 
-func (c *Direct) doLoginOrRegen(ctx context.Context, t *oauth2.Token, flags LoginFlags, regen bool, url string) (newUrl string, err error) {
+func (c *Direct) doLoginOrRegen(ctx context.Context, t *tailcfg.Oauth2Token, flags LoginFlags, regen bool, url string) (newUrl string, err error) {
 	mustregen, url, err := c.doLogin(ctx, t, flags, regen, url)
 	if err != nil {
 		return url, err
@@ -297,10 +283,11 @@ func (c *Direct) doLoginOrRegen(ctx context.Context, t *oauth2.Token, flags Logi
 	if mustregen {
 		_, url, err = c.doLogin(ctx, t, flags, true, url)
 	}
+
 	return url, err
 }
 
-func (c *Direct) doLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags, regen bool, url string) (mustregen bool, newurl string, err error) {
+func (c *Direct) doLogin(ctx context.Context, t *tailcfg.Oauth2Token, flags LoginFlags, regen bool, url string) (mustregen bool, newurl string, err error) {
 	c.mu.Lock()
 	persist := c.persist
 	tryingNewKey := c.tryingNewKey
@@ -317,6 +304,7 @@ func (c *Direct) doLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags,
 
 	if expired {
 		c.logf("Old key expired -> regen=true")
+		systemd.Status("key expired; run 'tailscale up' to authenticate")
 		regen = true
 	}
 	if (flags & LoginInteractive) != 0 {
@@ -325,7 +313,7 @@ func (c *Direct) doLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags,
 	}
 
 	c.logf("doLogin(regen=%v, hasUrl=%v)", regen, url != "")
-	if serverKey == (wgcfg.Key{}) {
+	if serverKey.IsZero() {
 		var err error
 		serverKey, err = loadServerKey(ctx, c.httpc, c.serverURL)
 		if err != nil {
@@ -337,12 +325,12 @@ func (c *Direct) doLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags,
 		c.mu.Unlock()
 	}
 
-	var oldNodeKey wgcfg.Key
+	var oldNodeKey wgkey.Key
 	if url != "" {
 	} else if regen || persist.PrivateNodeKey.IsZero() {
 		c.logf("Generating a new nodekey.")
 		persist.OldPrivateNodeKey = persist.PrivateNodeKey
-		key, err := wgcfg.NewPrivateKey()
+		key, err := wgkey.NewPrivate()
 		if err != nil {
 			c.logf("login keygen: %v", err)
 			return regen, url, err
@@ -363,12 +351,14 @@ func (c *Direct) doLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags,
 		err = errors.New("hostinfo: BackendLogID missing")
 		return regen, url, err
 	}
+	now := time.Now().Round(time.Second)
 	request := tailcfg.RegisterRequest{
 		Version:    1,
 		OldNodeKey: tailcfg.NodeKey(oldNodeKey),
 		NodeKey:    tailcfg.NodeKey(tryingNewKey.Public()),
 		Hostinfo:   hostinfo,
 		Followup:   url,
+		Timestamp:  &now,
 	}
 	c.logf("RegisterReq: onode=%v node=%v fup=%v",
 		request.OldNodeKey.ShortString(),
@@ -377,6 +367,20 @@ func (c *Direct) doLogin(ctx context.Context, t *oauth2.Token, flags LoginFlags,
 	request.Auth.Provider = persist.Provider
 	request.Auth.LoginName = persist.LoginName
 	request.Auth.AuthKey = authKey
+	err = signRegisterRequest(&request, c.serverURL, c.serverKey, c.machinePrivKey.Public())
+	if err != nil {
+		// If signing failed, clear all related fields
+		request.SignatureType = tailcfg.SignatureNone
+		request.Timestamp = nil
+		request.DeviceCert = nil
+		request.Signature = nil
+
+		// Don't log the common error types. Signatures are not usually enabled,
+		// so these are expected.
+		if err != errCertificateNotConfigured && err != errNoCertStore {
+			c.logf("RegisterReq sign error: %v", err)
+		}
+	}
 	bodyData, err := encode(request, &serverKey, &c.machinePrivKey)
 	if err != nil {
 		return regen, url, err
@@ -505,7 +509,19 @@ func inTest() bool { return flag.Lookup("test.v") != nil }
 //
 // maxPolls is how many network maps to download; common values are 1
 // or -1 (to keep a long-poll query open to the server).
-func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkMap)) error {
+func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*netmap.NetworkMap)) error {
+	return c.sendMapRequest(ctx, maxPolls, cb)
+}
+
+// SendLiteMapUpdate makes a /map request to update the server of our latest state,
+// but does not fetch anything. It returns an error if the server did not return a
+// successful 200 OK response.
+func (c *Direct) SendLiteMapUpdate(ctx context.Context) error {
+	return c.sendMapRequest(ctx, 1, nil)
+}
+
+// cb nil means to omit peers.
+func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*netmap.NetworkMap)) error {
 	c.mu.Lock()
 	persist := c.persist
 	serverURL := c.serverURL
@@ -517,20 +533,25 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 	everEndpoints := c.everEndpoints
 	c.mu.Unlock()
 
+	if persist.PrivateNodeKey.IsZero() {
+		return errors.New("privateNodeKey is zero")
+	}
 	if backendLogID == "" {
 		return errors.New("hostinfo: BackendLogID missing")
 	}
 
 	allowStream := maxPolls != 1
-	c.logf("PollNetMap: stream=%v :%v ep=%v", allowStream, localPort, ep)
+	c.logf("[v1] PollNetMap: stream=%v :%v ep=%v", allowStream, localPort, ep)
 
 	vlogf := logger.Discard
 	if Debug.NetMap {
+		// TODO(bradfitz): update this to use "[v2]" prefix perhaps? but we don't
+		// want to upload it always.
 		vlogf = c.logf
 	}
 
-	request := tailcfg.MapRequest{
-		Version:    5,
+	request := &tailcfg.MapRequest{
+		Version:    tailcfg.CurrentMapRequestVersion,
 		KeepAlive:  c.keepAlive,
 		NodeKey:    tailcfg.NodeKey(persist.PrivateNodeKey.Public()),
 		DiscoKey:   c.discoPubKey,
@@ -538,6 +559,21 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 		Stream:     allowStream,
 		Hostinfo:   hostinfo,
 		DebugFlags: c.debugFlags,
+		OmitPeers:  cb == nil,
+	}
+	var extraDebugFlags []string
+	if hostinfo != nil && c.linkMon != nil && ipForwardingBroken(hostinfo.RoutableIPs, c.linkMon.InterfaceState()) {
+		extraDebugFlags = append(extraDebugFlags, "warn-ip-forwarding-off")
+	}
+	if health.RouterHealth() != nil {
+		extraDebugFlags = append(extraDebugFlags, "warn-router-unhealthy")
+	}
+	if health.NetworkCategoryHealth() != nil {
+		extraDebugFlags = append(extraDebugFlags, "warn-network-category-unhealthy")
+	}
+	if len(extraDebugFlags) > 0 {
+		old := request.DebugFlags
+		request.DebugFlags = append(old[:len(old):len(old)], extraDebugFlags...)
 	}
 	if c.newDecompressor != nil {
 		request.Compress = "zstd"
@@ -586,6 +622,13 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 	}
 	defer res.Body.Close()
 
+	health.NoteMapRequestHeard(request)
+
+	if cb == nil {
+		io.Copy(ioutil.Discard, res.Body)
+		return nil
+	}
+
 	// If we go more than pollTimeout without hearing from the server,
 	// end the long poll. We should be receiving a keep alive ping
 	// every minute.
@@ -621,6 +664,8 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 
 	var lastDERPMap *tailcfg.DERPMap
 	var lastUserProfile = map[tailcfg.UserID]tailcfg.UserProfile{}
+	var lastParsedPacketFilter []filter.Match
+	var collectServices bool
 
 	// If allowStream, then the server will use an HTTP long poll to
 	// return incremental results. There is always one response right
@@ -652,6 +697,14 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 			return err
 		}
 
+		if allowStream {
+			health.GotStreamedMapResponse()
+		}
+
+		if pr := resp.PingRequest; pr != nil {
+			go answerPing(c.logf, c.httpc, pr)
+		}
+
 		if resp.KeepAlive {
 			vlogf("netmap: got keep-alive")
 		} else {
@@ -661,7 +714,7 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 		case timeoutReset <- struct{}{}:
 			vlogf("netmap: sent timer reset")
 		case <-ctx.Done():
-			c.logf("netmap: not resetting timer; context done: %v", ctx.Err())
+			c.logf("[v1] netmap: not resetting timer; context done: %v", ctx.Err())
 			return ctx.Err()
 		}
 		if resp.KeepAlive {
@@ -682,6 +735,9 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 			if resp.Debug.LogHeapPprof {
 				go logheap.LogHeap(resp.Debug.LogHeapURL)
 			}
+			if resp.Debug.GoroutineDumpURL != "" {
+				go dumpGoroutinesToURL(c.httpc, resp.Debug.GoroutineDumpURL)
+			}
 			setControlAtomic(&controlUseDERPRoute, resp.Debug.DERPRoute)
 			setControlAtomic(&controlTrimWGConfig, resp.Debug.TrimWGConfig)
 		}
@@ -697,24 +753,50 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 			}
 			resp.Peers = filtered
 		}
+		if Debug.StripEndpoints {
+			for _, p := range resp.Peers {
+				// We need at least one endpoint here for now else
+				// other code doesn't even create the discoEndpoint.
+				// TODO(bradfitz): fix that and then just nil this out.
+				p.Endpoints = []string{"127.9.9.9:456"}
+			}
+		}
 
-		nm := &NetworkMap{
-			NodeKey:      tailcfg.NodeKey(persist.PrivateNodeKey.Public()),
-			PrivateKey:   persist.PrivateNodeKey,
-			MachineKey:   machinePubKey,
-			Expiry:       resp.Node.KeyExpiry,
-			Name:         resp.Node.Name,
-			Addresses:    resp.Node.Addresses,
-			Peers:        resp.Peers,
-			LocalPort:    localPort,
-			User:         resp.Node.User,
-			UserProfiles: make(map[tailcfg.UserID]tailcfg.UserProfile),
-			Domain:       resp.Domain,
-			DNS:          resp.DNSConfig,
-			Hostinfo:     resp.Node.Hostinfo,
-			PacketFilter: c.parsePacketFilter(resp.PacketFilter),
-			DERPMap:      lastDERPMap,
-			Debug:        resp.Debug,
+		if pf := resp.PacketFilter; pf != nil {
+			lastParsedPacketFilter = c.parsePacketFilter(pf)
+		}
+
+		if v, ok := resp.CollectServices.Get(); ok {
+			collectServices = v
+		}
+
+		// Get latest localPort. This might've changed if
+		// a lite map update occured meanwhile. This only affects
+		// the end-to-end test.
+		// TODO(bradfitz): remove the NetworkMap.LocalPort field entirely.
+		c.mu.Lock()
+		localPort = c.localPort
+		c.mu.Unlock()
+
+		nm := &netmap.NetworkMap{
+			SelfNode:        resp.Node,
+			NodeKey:         tailcfg.NodeKey(persist.PrivateNodeKey.Public()),
+			PrivateKey:      persist.PrivateNodeKey,
+			MachineKey:      machinePubKey,
+			Expiry:          resp.Node.KeyExpiry,
+			Name:            resp.Node.Name,
+			Addresses:       resp.Node.Addresses,
+			Peers:           resp.Peers,
+			LocalPort:       localPort,
+			User:            resp.Node.User,
+			UserProfiles:    make(map[tailcfg.UserID]tailcfg.UserProfile),
+			Domain:          resp.Domain,
+			DNS:             resp.DNSConfig,
+			Hostinfo:        resp.Node.Hostinfo,
+			PacketFilter:    lastParsedPacketFilter,
+			CollectServices: collectServices,
+			DERPMap:         lastDERPMap,
+			Debug:           resp.Debug,
 		}
 		addUserProfile := func(userID tailcfg.UserID) {
 			if _, dup := nm.UserProfiles[userID]; dup {
@@ -726,7 +808,17 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 			}
 		}
 		addUserProfile(nm.User)
+		magicDNSSuffix := nm.MagicDNSSuffix()
+		nm.SelfNode.InitDisplayNames(magicDNSSuffix)
 		for _, peer := range resp.Peers {
+			peer.InitDisplayNames(magicDNSSuffix)
+			if !peer.Sharer.IsZero() {
+				if c.keepSharerAndUserSplit {
+					addUserProfile(peer.Sharer)
+				} else {
+					peer.User = peer.Sharer
+				}
+			}
 			addUserProfile(peer.User)
 		}
 		if resp.Node.MachineAuthorized {
@@ -735,7 +827,7 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 			nm.MachineStatus = tailcfg.MachineUnauthorized
 		}
 		if len(resp.DNS) > 0 {
-			nm.DNS.Nameservers = wgIPToNetaddr(resp.DNS)
+			nm.DNS.Nameservers = resp.DNS
 		}
 		if len(resp.SearchPaths) > 0 {
 			nm.DNS.Domains = resp.SearchPaths
@@ -752,7 +844,7 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 		now := c.timeNow()
 		if now.Sub(c.lastPrintMap) >= 5*time.Minute {
 			c.lastPrintMap = now
-			c.logf("new network map[%d]:\n%s", i, nm.Concise())
+			c.logf("[v1] new network map[%d]:\n%s", i, nm.Concise())
 		}
 
 		c.mu.Lock()
@@ -767,7 +859,7 @@ func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*NetworkM
 	return nil
 }
 
-func decode(res *http.Response, v interface{}, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) error {
+func decode(res *http.Response, v interface{}, serverKey *wgkey.Key, mkey *wgkey.Private) error {
 	defer res.Body.Close()
 	msg, err := ioutil.ReadAll(io.LimitReader(res.Body, 1<<20))
 	if err != nil {
@@ -781,6 +873,8 @@ func decode(res *http.Response, v interface{}, serverKey *wgcfg.Key, mkey *wgcfg
 
 var debugMap, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_MAP"))
 
+var jsonEscapedZero = []byte(`\u0000`)
+
 func (c *Direct) decodeMsg(msg []byte, v interface{}) error {
 	c.mu.Lock()
 	serverKey := c.serverKey
@@ -809,6 +903,10 @@ func (c *Direct) decodeMsg(msg []byte, v interface{}) error {
 		json.Indent(&buf, b, "", "    ")
 		log.Printf("MapResponse: %s", buf.Bytes())
 	}
+
+	if bytes.Contains(b, jsonEscapedZero) {
+		log.Printf("[unexpected] zero byte in controlclient.Direct.decodeMsg into %T: %q", v, b)
+	}
 	if err := json.Unmarshal(b, v); err != nil {
 		return fmt.Errorf("response: %v", err)
 	}
@@ -816,18 +914,21 @@ func (c *Direct) decodeMsg(msg []byte, v interface{}) error {
 
 }
 
-func decodeMsg(msg []byte, v interface{}, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) error {
+func decodeMsg(msg []byte, v interface{}, serverKey *wgkey.Key, mkey *wgkey.Private) error {
 	decrypted, err := decryptMsg(msg, serverKey, mkey)
 	if err != nil {
 		return err
 	}
+	if bytes.Contains(decrypted, jsonEscapedZero) {
+		log.Printf("[unexpected] zero byte in controlclient decodeMsg into %T: %q", v, decrypted)
+	}
 	if err := json.Unmarshal(decrypted, v); err != nil {
 		return fmt.Errorf("response: %v", err)
 	}
 	return nil
 }
 
-func decryptMsg(msg []byte, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) ([]byte, error) {
+func decryptMsg(msg []byte, serverKey *wgkey.Key, mkey *wgkey.Private) ([]byte, error) {
 	var nonce [24]byte
 	if len(msg) < len(nonce)+1 {
 		return nil, fmt.Errorf("response missing nonce, len=%d", len(msg))
@@ -843,13 +944,13 @@ func decryptMsg(msg []byte, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) ([]byt
 	return decrypted, nil
 }
 
-func encode(v interface{}, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) ([]byte, error) {
+func encode(v interface{}, serverKey *wgkey.Key, mkey *wgkey.Private) ([]byte, error) {
 	b, err := json.Marshal(v)
 	if err != nil {
 		return nil, err
 	}
 	if debugMap {
-		if _, ok := v.(tailcfg.MapRequest); ok {
+		if _, ok := v.(*tailcfg.MapRequest); ok {
 			log.Printf("MapRequest: %s", b)
 		}
 	}
@@ -862,60 +963,51 @@ func encode(v interface{}, serverKey *wgcfg.Key, mkey *wgcfg.PrivateKey) ([]byte
 	return msg, nil
 }
 
-func loadServerKey(ctx context.Context, httpc *http.Client, serverURL string) (wgcfg.Key, error) {
+func loadServerKey(ctx context.Context, httpc *http.Client, serverURL string) (wgkey.Key, error) {
 	req, err := http.NewRequest("GET", serverURL+"/key", nil)
 	if err != nil {
-		return wgcfg.Key{}, fmt.Errorf("create control key request: %v", err)
+		return wgkey.Key{}, fmt.Errorf("create control key request: %v", err)
 	}
 	req = req.WithContext(ctx)
 	res, err := httpc.Do(req)
 	if err != nil {
-		return wgcfg.Key{}, fmt.Errorf("fetch control key: %v", err)
+		return wgkey.Key{}, fmt.Errorf("fetch control key: %v", err)
 	}
 	defer res.Body.Close()
 	b, err := ioutil.ReadAll(io.LimitReader(res.Body, 1<<16))
 	if err != nil {
-		return wgcfg.Key{}, fmt.Errorf("fetch control key response: %v", err)
+		return wgkey.Key{}, fmt.Errorf("fetch control key response: %v", err)
 	}
 	if res.StatusCode != 200 {
-		return wgcfg.Key{}, fmt.Errorf("fetch control key: %d: %s", res.StatusCode, string(b))
+		return wgkey.Key{}, fmt.Errorf("fetch control key: %d: %s", res.StatusCode, string(b))
 	}
-	key, err := wgcfg.ParseHexKey(string(b))
+	key, err := wgkey.ParseHex(string(b))
 	if err != nil {
-		return wgcfg.Key{}, fmt.Errorf("fetch control key: %v", err)
+		return wgkey.Key{}, fmt.Errorf("fetch control key: %v", err)
 	}
 	return key, nil
 }
 
-func wgIPToNetaddr(ips []wgcfg.IP) (ret []netaddr.IP) {
-	for _, ip := range ips {
-		nip, ok := netaddr.FromStdIP(ip.IP())
-		if !ok {
-			panic(fmt.Sprintf("conversion of %s from wgcfg to netaddr IP failed", ip))
-		}
-		ret = append(ret, nip.Unmap())
-	}
-	return ret
-}
-
 // Debug contains temporary internal-only debug knobs.
 // They're unexported to not draw attention to them.
 var Debug = initDebug()
 
 type debug struct {
-	NetMap    bool
-	ProxyDNS  bool
-	OnlyDisco bool
-	Disco     bool
+	NetMap         bool
+	ProxyDNS       bool
+	OnlyDisco      bool
+	Disco          bool
+	StripEndpoints bool // strip endpoints from control (only use disco messages)
 }
 
 func initDebug() debug {
 	use := os.Getenv("TS_DEBUG_USE_DISCO")
 	return debug{
-		NetMap:    envBool("TS_DEBUG_NETMAP"),
-		ProxyDNS:  envBool("TS_DEBUG_PROXY_DNS"),
-		OnlyDisco: use == "only",
-		Disco:     use == "only" || use == "" || envBool("TS_DEBUG_USE_DISCO"),
+		NetMap:         envBool("TS_DEBUG_NETMAP"),
+		ProxyDNS:       envBool("TS_DEBUG_PROXY_DNS"),
+		StripEndpoints: envBool("TS_DEBUG_STRIP_ENDPOINTS"),
+		OnlyDisco:      use == "only",
+		Disco:          use == "only" || use == "" || envBool("TS_DEBUG_USE_DISCO"),
 	}
 }
 
@@ -996,6 +1088,24 @@ func undeltaPeers(mapRes *tailcfg.MapResponse, prev []*tailcfg.Node) {
 		}
 	}
 	sortNodes(newFull)
+
+	if mapRes.PeerSeenChange != nil {
+		peerByID := make(map[tailcfg.NodeID]*tailcfg.Node, len(newFull))
+		for _, n := range newFull {
+			peerByID[n.ID] = n
+		}
+		now := time.Now()
+		for nodeID, seen := range mapRes.PeerSeenChange {
+			if n, ok := peerByID[nodeID]; ok {
+				if seen {
+					n.LastSeen = &now
+				} else {
+					n.LastSeen = nil
+				}
+			}
+		}
+	}
+
 	mapRes.Peers = newFull
 	mapRes.PeersChanged = nil
 	mapRes.PeersRemoved = nil
@@ -1051,3 +1161,114 @@ func TrimWGConfig() opt.Bool {
 	v, _ := controlTrimWGConfig.Load().(opt.Bool)
 	return v
 }
+
+// ipForwardingBroken reports whether the system's IP forwarding is disabled
+// and will definitely not work for the routes provided.
+//
+// It should not return false positives.
+func ipForwardingBroken(routes []netaddr.IPPrefix, state *interfaces.State) bool {
+	if len(routes) == 0 {
+		// Nothing to route, so no need to warn.
+		return false
+	}
+
+	if runtime.GOOS != "linux" {
+		// We only do subnet routing on Linux for now.
+		// It might work on darwin/macOS when building from source, so
+		// don't return true for other OSes. We can OS-based warnings
+		// already in the admin panel.
+		return false
+	}
+
+	localIPs := map[netaddr.IP]bool{}
+	for _, addrs := range state.InterfaceIPs {
+		for _, pfx := range addrs {
+			localIPs[pfx.IP] = true
+		}
+	}
+
+	v4Routes, v6Routes := false, false
+	for _, r := range routes {
+		// It's possible to advertise a route to one of the local
+		// machine's local IPs. IP forwarding isn't required for this
+		// to work, so we shouldn't warn for such exports.
+		if r.IsSingleIP() && localIPs[r.IP] {
+			continue
+		}
+		if r.IP.Is4() {
+			v4Routes = true
+		} else {
+			v6Routes = true
+		}
+	}
+
+	if v4Routes {
+		out, err := ioutil.ReadFile("/proc/sys/net/ipv4/ip_forward")
+		if err != nil {
+			// Try another way.
+			out, err = exec.Command("sysctl", "-n", "net.ipv4.ip_forward").Output()
+		}
+		if err != nil {
+			// Oh well, we tried. This is just for debugging.
+			// We don't want false positives.
+			// TODO: maybe we want a different warning for inability to check?
+			return false
+		}
+		if strings.TrimSpace(string(out)) == "0" {
+			return true
+		}
+	}
+	if v6Routes {
+		// Note: you might be wondering why we check only the state of
+		// conf.all.forwarding, rather than per-interface forwarding
+		// configuration. According to kernel documentation, it seems
+		// that to actually forward packets, you need to enable
+		// forwarding globally, and the per-interface forwarding
+		// setting only alters other things such as how router
+		// advertisements are handled. The kernel itself warns that
+		// enabling forwarding per-interface and not globally will
+		// probably not work, so I feel okay calling those configs
+		// broken until we have proof otherwise.
+		out, err := ioutil.ReadFile("/proc/sys/net/ipv6/conf/all/forwarding")
+		if err != nil {
+			out, err = exec.Command("sysctl", "-n", "net.ipv6.conf.all.forwarding").Output()
+		}
+		if err != nil {
+			// Oh well, we tried. This is just for debugging.
+			// We don't want false positives.
+			// TODO: maybe we want a different warning for inability to check?
+			return false
+		}
+		if strings.TrimSpace(string(out)) == "0" {
+			return true
+		}
+	}
+
+	return false
+}
+
+func answerPing(logf logger.Logf, c *http.Client, pr *tailcfg.PingRequest) {
+	if pr.URL == "" {
+		logf("invalid PingRequest with no URL")
+		return
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(ctx, "HEAD", pr.URL, nil)
+	if err != nil {
+		logf("http.NewRequestWithContext(%q): %v", pr.URL, err)
+		return
+	}
+	if pr.Log {
+		logf("answerPing: sending ping to %v ...", pr.URL)
+	}
+	t0 := time.Now()
+	_, err = c.Do(req)
+	d := time.Since(t0).Round(time.Millisecond)
+	if err != nil {
+		logf("answerPing error: %v to %v (after %v)", err, pr.URL, d)
+	} else if pr.Log {
+		logf("answerPing complete to %v (after %v)", pr.URL, d)
+	}
+}

control/controlclient/direct_clone.go

@@ -1,20 +0,0 @@
-// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Code generated by tailscale.com/cmd/cloner -type Persist; DO NOT EDIT.
-
-package controlclient
-
-import ()
-
-// Clone makes a deep copy of Persist.
-// The result aliases no memory with the original.
-func (src *Persist) Clone() *Persist {
-	if src == nil {
-		return nil
-	}
-	dst := new(Persist)
-	*dst = *src
-	return dst
-}

control/controlclient/direct_test.go

@@ -5,12 +5,14 @@
 package controlclient
 
 import (
+	"encoding/json"
 	"fmt"
 	"reflect"
 	"strings"
 	"testing"
 
 	"tailscale.com/tailcfg"
+	"tailscale.com/types/wgkey"
 )
 
 func TestUndeltaPeers(t *testing.T) {
@@ -91,3 +93,79 @@ func formatNodes(nodes []*tailcfg.Node) string {
 	}
 	return sb.String()
 }
+
+func TestNewDirect(t *testing.T) {
+	hi := NewHostinfo()
+	ni := tailcfg.NetInfo{LinkType: "wired"}
+	hi.NetInfo = &ni
+
+	key, err := wgkey.NewPrivate()
+	if err != nil {
+		t.Error(err)
+	}
+	opts := Options{ServerURL: "https://example.com", MachinePrivateKey: key, Hostinfo: hi}
+	c, err := NewDirect(opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if c.serverURL != opts.ServerURL {
+		t.Errorf("c.serverURL got %v want %v", c.serverURL, opts.ServerURL)
+	}
+
+	if !hi.Equal(c.hostinfo) {
+		t.Errorf("c.hostinfo got %v want %v", c.hostinfo, hi)
+	}
+
+	changed := c.SetNetInfo(&ni)
+	if changed {
+		t.Errorf("c.SetNetInfo(ni) want false got %v", changed)
+	}
+	ni = tailcfg.NetInfo{LinkType: "wifi"}
+	changed = c.SetNetInfo(&ni)
+	if !changed {
+		t.Errorf("c.SetNetInfo(ni) want true got %v", changed)
+	}
+
+	changed = c.SetHostinfo(hi)
+	if changed {
+		t.Errorf("c.SetHostinfo(hi) want false got %v", changed)
+	}
+	hi = NewHostinfo()
+	hi.Hostname = "different host name"
+	changed = c.SetHostinfo(hi)
+	if !changed {
+		t.Errorf("c.SetHostinfo(hi) want true got %v", changed)
+	}
+
+	endpoints := []string{"1", "2", "3"}
+	changed = c.newEndpoints(12, endpoints)
+	if !changed {
+		t.Errorf("c.newEndpoints(12) want true got %v", changed)
+	}
+	changed = c.newEndpoints(12, endpoints)
+	if changed {
+		t.Errorf("c.newEndpoints(12) want false got %v", changed)
+	}
+	changed = c.newEndpoints(13, endpoints)
+	if !changed {
+		t.Errorf("c.newEndpoints(13) want true got %v", changed)
+	}
+	endpoints = []string{"4", "5", "6"}
+	changed = c.newEndpoints(13, endpoints)
+	if !changed {
+		t.Errorf("c.newEndpoints(13) want true got %v", changed)
+	}
+}
+
+func TestNewHostinfo(t *testing.T) {
+	hi := NewHostinfo()
+	if hi == nil {
+		t.Fatal("no Hostinfo")
+	}
+	j, err := json.MarshalIndent(hi, "  ", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("Got: %s", j)
+}

control/controlclient/filter.go

@@ -9,9 +9,9 @@ import (
 	"tailscale.com/wgengine/filter"
 )
 
-// Parse a backward-compatible FilterRule used by control's wire format,
-// producing the most current filter.Matches format.
-func (c *Direct) parsePacketFilter(pf []tailcfg.FilterRule) filter.Matches {
+// Parse a backward-compatible FilterRule used by control's wire
+// format, producing the most current filter format.
+func (c *Direct) parsePacketFilter(pf []tailcfg.FilterRule) []filter.Match {
 	mm, err := filter.MatchesFromFilterRules(pf)
 	if err != nil {
 		c.logf("parsePacketFilter: %s\n", err)

control/controlclient/hostinfo_linux.go

@@ -73,7 +73,7 @@ func osVersionLinux() string {
 			return fmt.Sprintf("%s%s", bytes.TrimSpace(cr), attr)
 		}
 		fallthrough
-	case "fedora", "rhel", "alpine":
+	case "fedora", "rhel", "alpine", "nixos":
 		// Their PRETTY_NAME is fine as-is for all versions I tested.
 		fallthrough
 	default:

control/controlclient/hostinfo_windows.go

@@ -7,6 +7,7 @@ package controlclient
 import (
 	"os/exec"
 	"strings"
+	"sync/atomic"
 	"syscall"
 )
 
@@ -14,7 +15,12 @@ func init() {
 	osVersion = osVersionWindows
 }
 
+var winVerCache atomic.Value // of string
+
 func osVersionWindows() string {
+	if s, ok := winVerCache.Load().(string); ok {
+		return s
+	}
 	cmd := exec.Command("cmd", "/c", "ver")
 	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
 	out, _ := cmd.Output() // "\nMicrosoft Windows [Version 10.0.19041.388]\n\n"
@@ -26,5 +32,8 @@ func osVersionWindows() string {
 	if sp := strings.Index(s, " "); sp != -1 {
 		s = s[sp+1:]
 	}
+	if s != "" {
+		winVerCache.Store(s)
+	}
 	return s // "10.0.19041.388", ideally
 }

control/controlclient/sign.go

@@ -0,0 +1,31 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package controlclient
+
+import (
+	"crypto"
+	"errors"
+	"fmt"
+	"time"
+
+	"tailscale.com/types/wgkey"
+)
+
+var (
+	errNoCertStore              = errors.New("no certificate store")
+	errCertificateNotConfigured = errors.New("no certificate subject configured")
+)
+
+// HashRegisterRequest generates the hash required sign or verify a
+// tailcfg.RegisterRequest with tailcfg.SignatureV1.
+func HashRegisterRequest(ts time.Time, serverURL string, deviceCert []byte, serverPubKey, machinePubKey wgkey.Key) []byte {
+	h := crypto.SHA256.New()
+
+	// hash.Hash.Write never returns an error, so we don't check for one here.
+	fmt.Fprintf(h, "%s%s%s%s%s",
+		ts.UTC().Format(time.RFC3339), serverURL, deviceCert, serverPubKey, machinePubKey)
+
+	return h.Sum(nil)
+}

control/controlclient/sign_supported.go

@@ -0,0 +1,160 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build windows,cgo
+
+// darwin,cgo is also supported by certstore but machineCertificateSubject will
+// need to be loaded by a different mechanism, so this is not currently enabled
+// on darwin.
+
+package controlclient
+
+import (
+	"crypto"
+	"crypto/rsa"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"sync"
+
+	"github.com/github/certstore"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/wgkey"
+	"tailscale.com/util/winutil"
+)
+
+var getMachineCertificateSubjectOnce struct {
+	sync.Once
+	v string // Subject of machine certificate to search for
+}
+
+// getMachineCertificateSubject returns the exact name of a Subject that needs
+// to be present in an identity's certificate chain to sign a RegisterRequest,
+// formatted as per pkix.Name.String(). The Subject may be that of the identity
+// itself, an intermediate CA or the root CA.
+//
+// If getMachineCertificateSubject() returns "" then no lookup will occur and
+// each RegisterRequest will be unsigned.
+//
+// Example: "CN=Tailscale Inc Test Root CA,OU=Tailscale Inc Test Certificate Authority,O=Tailscale Inc,ST=ON,C=CA"
+func getMachineCertificateSubject() string {
+	getMachineCertificateSubjectOnce.Do(func() {
+		getMachineCertificateSubjectOnce.v = winutil.GetRegString("MachineCertificateSubject", "")
+	})
+
+	return getMachineCertificateSubjectOnce.v
+}
+
+var (
+	errNoMatch    = errors.New("no matching certificate")
+	errBadRequest = errors.New("malformed request")
+)
+
+// findIdentity locates an identity from the Windows or Darwin certificate
+// store. It returns the first certificate with a matching Subject anywhere in
+// its certificate chain, so it is possible to search for the leaf certificate,
+// intermediate CA or root CA. If err is nil then the returned identity will
+// never be nil (if no identity is found, the error errNoMatch will be
+// returned). If an identity is returned then its certificate chain is also
+// returned.
+func findIdentity(subject string, st certstore.Store) (certstore.Identity, []*x509.Certificate, error) {
+	ids, err := st.Identities()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var selected certstore.Identity
+	var chain []*x509.Certificate
+
+	for _, id := range ids {
+		chain, err = id.CertificateChain()
+		if err != nil {
+			continue
+		}
+
+		if chain[0].PublicKeyAlgorithm != x509.RSA {
+			continue
+		}
+
+		for _, c := range chain {
+			if c.Subject.String() == subject {
+				selected = id
+				break
+			}
+		}
+	}
+
+	for _, id := range ids {
+		if id != selected {
+			id.Close()
+		}
+	}
+
+	if selected == nil {
+		return nil, nil, errNoMatch
+	}
+
+	return selected, chain, nil
+}
+
+// signRegisterRequest looks for a suitable machine identity from the local
+// system certificate store, and if one is found, signs the RegisterRequest
+// using that identity's public key. In addition to the signature, the full
+// certificate chain is included so that the control server can validate the
+// certificate from a copy of the root CA's certificate.
+func signRegisterRequest(req *tailcfg.RegisterRequest, serverURL string, serverPubKey, machinePubKey wgkey.Key) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("signRegisterRequest: %w", err)
+		}
+	}()
+
+	if req.Timestamp == nil {
+		return errBadRequest
+	}
+
+	machineCertificateSubject := getMachineCertificateSubject()
+	if machineCertificateSubject == "" {
+		return errCertificateNotConfigured
+	}
+
+	st, err := certstore.Open(certstore.System)
+	if err != nil {
+		return fmt.Errorf("open cert store: %w", err)
+	}
+	defer st.Close()
+
+	id, chain, err := findIdentity(machineCertificateSubject, st)
+	if err != nil {
+		return fmt.Errorf("find identity: %w", err)
+	}
+	defer id.Close()
+
+	signer, err := id.Signer()
+	if err != nil {
+		return fmt.Errorf("create signer: %w", err)
+	}
+
+	cl := 0
+	for _, c := range chain {
+		cl += len(c.Raw)
+	}
+	req.DeviceCert = make([]byte, 0, cl)
+	for _, c := range chain {
+		req.DeviceCert = append(req.DeviceCert, c.Raw...)
+	}
+
+	h := HashRegisterRequest(req.Timestamp.UTC(), serverURL, req.DeviceCert, serverPubKey, machinePubKey)
+
+	req.Signature, err = signer.Sign(nil, h, &rsa.PSSOptions{
+		SaltLength: rsa.PSSSaltLengthEqualsHash,
+		Hash:       crypto.SHA256,
+	})
+	if err != nil {
+		return fmt.Errorf("sign: %w", err)
+	}
+	req.SignatureType = tailcfg.SignatureV1
+
+	return nil
+}

control/controlclient/sign_unsupported.go

@@ -0,0 +1,17 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows !cgo
+
+package controlclient
+
+import (
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/wgkey"
+)
+
+// signRegisterRequest on non-supported platforms always returns errNoCertStore.
+func signRegisterRequest(req *tailcfg.RegisterRequest, serverURL string, serverPubKey, machinePubKey wgkey.Key) error {
+	return errNoCertStore
+}

derp/derp.go

@@ -59,7 +59,8 @@ Login:
 * server sends frameServerInfo
 
 Steady state:
-* server occasionally sends frameKeepAlive
+* server occasionally sends frameKeepAlive (or framePing)
+* client responds to any framePing with a framePong
 * client sends frameSendPacket
 * server then sends frameRecvPacket to recipient
 */
@@ -97,6 +98,9 @@ const (
 	// connection. (To be used for cluster load balancing
 	// purposes, when clients end up on a non-ideal node)
 	frameClosePeer = frameType(0x11) // 32B pub key of peer to close.
+
+	framePing = frameType(0x12) // 8 byte ping payload, to be echoed back in framePong
+	framePong = frameType(0x13) // 8 byte payload, the contents of the ping being replied to
 )
 
 var bin = binary.BigEndian

derp/derp_client.go

@@ -21,13 +21,14 @@ import (
 
 // Client is a DERP client.
 type Client struct {
-	serverKey  key.Public // of the DERP server; not a machine or node key
-	privateKey key.Private
-	publicKey  key.Public // of privateKey
-	logf       logger.Logf
-	nc         Conn
-	br         *bufio.Reader
-	meshKey    string
+	serverKey   key.Public // of the DERP server; not a machine or node key
+	privateKey  key.Private
+	publicKey   key.Public // of privateKey
+	logf        logger.Logf
+	nc          Conn
+	br          *bufio.Reader
+	meshKey     string
+	canAckPings bool
 
 	wmu sync.Mutex // hold while writing to bw
 	bw  *bufio.Writer
@@ -48,8 +49,9 @@ func (f clientOptFunc) update(o *clientOpt) { f(o) }
 
 // clientOpt are the options passed to newClient.
 type clientOpt struct {
-	MeshKey   string
-	ServerPub key.Public
+	MeshKey     string
+	ServerPub   key.Public
+	CanAckPings bool
 }
 
 // MeshKey returns a ClientOpt to pass to the DERP server during connect to get
@@ -64,6 +66,12 @@ func ServerPublicKey(key key.Public) ClientOpt {
 	return clientOptFunc(func(o *clientOpt) { o.ServerPub = key })
 }
 
+// CanAckPings returns a ClientOpt to set whether it advertises to the
+// server that it's capable of acknowledging ping requests.
+func CanAckPings(v bool) ClientOpt {
+	return clientOptFunc(func(o *clientOpt) { o.CanAckPings = v })
+}
+
 func NewClient(privateKey key.Private, nc Conn, brw *bufio.ReadWriter, logf logger.Logf, opts ...ClientOpt) (*Client, error) {
 	var opt clientOpt
 	for _, o := range opts {
@@ -77,13 +85,14 @@ func NewClient(privateKey key.Private, nc Conn, brw *bufio.ReadWriter, logf logg
 
 func newClient(privateKey key.Private, nc Conn, brw *bufio.ReadWriter, logf logger.Logf, opt clientOpt) (*Client, error) {
 	c := &Client{
-		privateKey: privateKey,
-		publicKey:  privateKey.Public(),
-		logf:       logf,
-		nc:         nc,
-		br:         brw.Reader,
-		bw:         brw.Writer,
-		meshKey:    opt.MeshKey,
+		privateKey:  privateKey,
+		publicKey:   privateKey.Public(),
+		logf:        logf,
+		nc:          nc,
+		br:          brw.Reader,
+		bw:          brw.Writer,
+		meshKey:     opt.MeshKey,
+		canAckPings: opt.CanAckPings,
 	}
 	if opt.ServerPub.IsZero() {
 		if err := c.recvServerKey(); err != nil {
@@ -147,6 +156,10 @@ type clientInfo struct {
 	// connection list & forward packets. It's empty for regular
 	// users.
 	MeshKey string `json:"meshKey,omitempty"`
+
+	// CanAckPings is whether the client declares it's able to ack
+	// pings.
+	CanAckPings bool
 }
 
 func (c *Client) sendClientKey() error {
@@ -155,8 +168,9 @@ func (c *Client) sendClientKey() error {
 		return err
 	}
 	msg, err := json.Marshal(clientInfo{
-		Version: ProtocolVersion,
-		MeshKey: c.meshKey,
+		Version:     ProtocolVersion,
+		MeshKey:     c.meshKey,
+		CanAckPings: c.canAckPings,
 	})
 	if err != nil {
 		return err
@@ -238,6 +252,18 @@ func (c *Client) ForwardPacket(srcKey, dstKey key.Public, pkt []byte) (err error
 
 func (c *Client) writeTimeoutFired() { c.nc.Close() }
 
+func (c *Client) SendPong(data [8]byte) error {
+	c.wmu.Lock()
+	defer c.wmu.Unlock()
+	if err := writeFrameHeader(c.bw, framePong, 8); err != nil {
+		return err
+	}
+	if _, err := c.bw.Write(data[:]); err != nil {
+		return err
+	}
+	return c.bw.Flush()
+}
+
 // NotePreferred sends a packet that tells the server whether this
 // client is the user's preferred server. This is only used in the
 // server for stats.
@@ -319,6 +345,19 @@ type ServerInfoMessage struct{}
 
 func (ServerInfoMessage) msg() {}
 
+// PingMessage is a request from a client or server to reply to the
+// other side with a PongMessage with the given payload.
+type PingMessage [8]byte
+
+func (PingMessage) msg() {}
+
+// KeepAliveMessage is a one-way empty message from server to client, just to
+// keep the connection alive. It's like a PingMessage, but doesn't solicit
+// a reply from the client.
+type KeepAliveMessage struct{}
+
+func (KeepAliveMessage) msg() {}
+
 // Recv reads a message from the DERP server.
 //
 // The returned message may alias memory owned by the Client; it
@@ -397,9 +436,9 @@ func (c *Client) recvTimeout(timeout time.Duration) (m ReceivedMessage, err erro
 			// TODO: add the results of parseServerInfo to ServerInfoMessage if we ever need it.
 			return ServerInfoMessage{}, nil
 		case frameKeepAlive:
-			// TODO: eventually we'll have server->client pings that
-			// require ack pongs.
-			continue
+			// A one-way keep-alive message that doesn't require an acknowledgement.
+			// This predated framePing/framePong.
+			return KeepAliveMessage{}, nil
 		case framePeerGone:
 			if n < keyLen {
 				c.logf("[unexpected] dropping short peerGone frame from DERP server")
@@ -427,6 +466,15 @@ func (c *Client) recvTimeout(timeout time.Duration) (m ReceivedMessage, err erro
 			copy(rp.Source[:], b[:keyLen])
 			rp.Data = b[keyLen:n]
 			return rp, nil
+
+		case framePing:
+			var pm PingMessage
+			if n < 8 {
+				c.logf("[unexpected] dropping short ping frame")
+				continue
+			}
+			copy(pm[:], b[:])
+			return pm, nil
 		}
 	}
 }

derp/derp_test.go

@@ -6,6 +6,7 @@ package derp
 
 import (
 	"bufio"
+	"bytes"
 	"context"
 	crand "crypto/rand"
 	"crypto/x509"
@@ -791,6 +792,63 @@ func TestMetaCert(t *testing.T) {
 	}
 }
 
+type dummyNetConn struct {
+	net.Conn
+}
+
+func (dummyNetConn) SetReadDeadline(time.Time) error { return nil }
+
+func TestClientRecv(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []byte
+		want  interface{}
+	}{
+		{
+			name: "ping",
+			input: []byte{
+				byte(framePing), 0, 0, 0, 8,
+				1, 2, 3, 4, 5, 6, 7, 8,
+			},
+			want: PingMessage{1, 2, 3, 4, 5, 6, 7, 8},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := &Client{
+				nc:   dummyNetConn{},
+				br:   bufio.NewReader(bytes.NewReader(tt.input)),
+				logf: t.Logf,
+			}
+			got, err := c.Recv()
+			if err != nil {
+				t.Fatal(err)
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("got %#v; want %#v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestClientSendPong(t *testing.T) {
+	var buf bytes.Buffer
+	c := &Client{
+		bw: bufio.NewWriter(&buf),
+	}
+	if err := c.SendPong([8]byte{1, 2, 3, 4, 5, 6, 7, 8}); err != nil {
+		t.Fatal(err)
+	}
+	want := []byte{
+		byte(framePong), 0, 0, 0, 8,
+		1, 2, 3, 4, 5, 6, 7, 8,
+	}
+	if !bytes.Equal(buf.Bytes(), want) {
+		t.Errorf("unexpected output\nwrote: % 02x\n want: % 02x", buf.Bytes(), want)
+	}
+
+}
+
 func BenchmarkSendRecv(b *testing.B) {
 	for _, size := range []int{10, 100, 1000, 10000} {
 		b.Run(fmt.Sprintf("msgsize=%d", size), func(b *testing.B) { benchmarkSendRecvSize(b, size) })

derp/derphttp/derphttp_client.go

@@ -63,6 +63,7 @@ type Client struct {
 
 	mu           sync.Mutex
 	preferred    bool
+	canAckPings  bool
 	closed       bool
 	netConn      io.Closer
 	client       *derp.Client
@@ -333,7 +334,11 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien
 			return nil, 0, fmt.Errorf("GET failed: %v: %s", err, b)
 		}
 	}
-	derpClient, err = derp.NewClient(c.privateKey, httpConn, brw, c.logf, derp.MeshKey(c.MeshKey), derp.ServerPublicKey(serverPub))
+	derpClient, err = derp.NewClient(c.privateKey, httpConn, brw, c.logf,
+		derp.MeshKey(c.MeshKey),
+		derp.ServerPublicKey(serverPub),
+		derp.CanAckPings(c.canAckPings),
+	)
 	if err != nil {
 		return nil, 0, err
 	}
@@ -358,7 +363,7 @@ func (c *Client) dialURL(ctx context.Context) (net.Conn, error) {
 	dialer := netns.NewDialer()
 
 	if c.DNSCache != nil {
-		ip, err := c.DNSCache.LookupIP(ctx, host)
+		ip, _, err := c.DNSCache.LookupIP(ctx, host)
 		if err == nil {
 			hostOrIP = ip.String()
 		}
@@ -642,6 +647,38 @@ func (c *Client) ForwardPacket(from, to key.Public, b []byte) error {
 	return err
 }
 
+// SendPong sends a reply to a ping, with the ping's provided
+// challenge/identifier data.
+//
+// Unlike other send methods, SendPong makes no attempt to connect or
+// reconnect to the peer. It's best effort. If there's a connection
+// problem, the server will choose to hang up on us if we're not
+// replying.
+func (c *Client) SendPong(data [8]byte) error {
+	c.mu.Lock()
+	if c.closed {
+		c.mu.Unlock()
+		return ErrClientClosed
+	}
+	if c.client == nil {
+		c.mu.Unlock()
+		return errors.New("not connected")
+	}
+	dc := c.client
+	c.mu.Unlock()
+
+	return dc.SendPong(data)
+}
+
+// SetCanAckPings sets whether this client will reply to ping requests from the server.
+//
+// This only affects future connections.
+func (c *Client) SetCanAckPings(v bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.canAckPings = v
+}
+
 // NotePreferred notes whether this Client is the caller's preferred
 // (home) DERP node. It's only used for stats.
 func (c *Client) NotePreferred(v bool) {
@@ -709,10 +746,19 @@ func (c *Client) RecvDetail() (m derp.ReceivedMessage, connGen int, err error) {
 	m, err = client.Recv()
 	if err != nil {
 		c.closeForReconnect(client)
+		if c.isClosed() {
+			err = ErrClientClosed
+		}
 	}
 	return m, connGen, err
 }
 
+func (c *Client) isClosed() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.closed
+}
+
 // Close closes the client. It will not automatically reconnect after
 // being closed.
 func (c *Client) Close() error {

derp/derphttp/mesh_client.go

@@ -5,20 +5,32 @@
 package derphttp
 
 import (
+	"context"
 	"sync"
 	"time"
 
 	"tailscale.com/derp"
 	"tailscale.com/types/key"
+	"tailscale.com/types/logger"
 )
 
-// RunWatchConnectionLoop loops forever, sending WatchConnectionChanges and subscribing to
+// RunWatchConnectionLoop loops until ctx is done, sending WatchConnectionChanges and subscribing to
 // connection changes.
 //
 // If the server's public key is ignoreServerKey, RunWatchConnectionLoop returns.
 //
 // Otherwise, the add and remove funcs are called as clients come & go.
-func (c *Client) RunWatchConnectionLoop(ignoreServerKey key.Public, add, remove func(key.Public)) {
+//
+// infoLogf, if non-nil, is the logger to write periodic status
+// updates about how many peers are on the server. Error log output is
+// set to the c's logger, regardless of infoLogf's value.
+//
+// To force RunWatchConnectionLoop to return quickly, its ctx needs to
+// be closed, and c itself needs to be closed.
+func (c *Client) RunWatchConnectionLoop(ctx context.Context, ignoreServerKey key.Public, infoLogf logger.Logf, add, remove func(key.Public)) {
+	if infoLogf == nil {
+		infoLogf = logger.Discard
+	}
 	logf := c.logf
 	const retryInterval = 5 * time.Second
 	const statusInterval = 10 * time.Second
@@ -45,7 +57,7 @@ func (c *Client) RunWatchConnectionLoop(ignoreServerKey key.Public, add, remove
 		if loggedConnected {
 			return
 		}
-		logf("connected; %d peers", len(present))
+		infoLogf("connected; %d peers", len(present))
 		loggedConnected = true
 	}
 
@@ -79,12 +91,21 @@ func (c *Client) RunWatchConnectionLoop(ignoreServerKey key.Public, add, remove
 		}
 	}
 
-	for {
+	sleep := func(d time.Duration) {
+		t := time.NewTimer(d)
+		select {
+		case <-ctx.Done():
+			t.Stop()
+		case <-t.C:
+		}
+	}
+
+	for ctx.Err() == nil {
 		err := c.WatchConnectionChanges()
 		if err != nil {
 			clear()
 			logf("WatchConnectionChanges: %v", err)
-			time.Sleep(retryInterval)
+			sleep(retryInterval)
 			continue
 		}
 
@@ -97,7 +118,7 @@ func (c *Client) RunWatchConnectionLoop(ignoreServerKey key.Public, add, remove
 			if err != nil {
 				clear()
 				logf("Recv: %v", err)
-				time.Sleep(retryInterval)
+				sleep(retryInterval)
 				break
 			}
 			if connGen != lastConnGen {
@@ -114,9 +135,8 @@ func (c *Client) RunWatchConnectionLoop(ignoreServerKey key.Public, add, remove
 			}
 			if now := time.Now(); now.Sub(lastStatus) > statusInterval {
 				lastStatus = now
-				logf("%d peers", len(present))
+				infoLogf("%d peers", len(present))
 			}
 		}
 	}
-
 }

disco/disco.go

@@ -70,7 +70,7 @@ func Parse(p []byte) (Message, error) {
 	case TypePong:
 		return parsePong(ver, p)
 	case TypeCallMeMaybe:
-		return CallMeMaybe{}, nil
+		return parseCallMeMaybe(ver, p)
 	default:
 		return nil, fmt.Errorf("unknown message type 0x%02x", byte(t))
 	}
@@ -122,13 +122,57 @@ func parsePing(ver uint8, p []byte) (m *Ping, err error) {
 //
 // The recipient may choose to not open a path back, if it's already
 // happy with its path. But usually it will.
-type CallMeMaybe struct{}
+type CallMeMaybe struct {
+	// MyNumber is what the peer believes its endpoints are.
+	//
+	// Prior to Tailscale 1.4, the endpoints were exchanged purely
+	// between nodes and the control server.
+	//
+	// Starting with Tailscale 1.4, clients advertise their endpoints.
+	// Older clients won't use this, but newer clients should
+	// use any endpoints in here that aren't included from control.
+	//
+	// Control might have sent stale endpoints if the client was idle
+	// before contacting us. In that case, the client likely did a STUN
+	// request immediately before sending the CallMeMaybe to recreate
+	// their NAT port mapping, and that new good endpoint is included
+	// in this field, but might not yet be in control's endpoints.
+	// (And in the future, control will stop distributing endpoints
+	// when clients are suitably new.)
+	MyNumber []netaddr.IPPort
+}
 
-func (CallMeMaybe) AppendMarshal(b []byte) []byte {
-	ret, _ := appendMsgHeader(b, TypeCallMeMaybe, v0, 0)
+const epLength = 16 + 2 // 16 byte IP address + 2 byte port
+
+func (m *CallMeMaybe) AppendMarshal(b []byte) []byte {
+	ret, p := appendMsgHeader(b, TypeCallMeMaybe, v0, epLength*len(m.MyNumber))
+	for _, ipp := range m.MyNumber {
+		a := ipp.IP.As16()
+		copy(p[:], a[:])
+		binary.BigEndian.PutUint16(p[16:], ipp.Port)
+		p = p[epLength:]
+	}
 	return ret
 }
 
+func parseCallMeMaybe(ver uint8, p []byte) (m *CallMeMaybe, err error) {
+	m = new(CallMeMaybe)
+	if len(p)%epLength != 0 || ver != 0 || len(p) == 0 {
+		return m, nil
+	}
+	m.MyNumber = make([]netaddr.IPPort, 0, len(p)/epLength)
+	for len(p) > 0 {
+		var a [16]byte
+		copy(a[:], p)
+		m.MyNumber = append(m.MyNumber, netaddr.IPPort{
+			IP:   netaddr.IPFrom16(a),
+			Port: binary.BigEndian.Uint16(p[16:18]),
+		})
+		p = p[epLength:]
+	}
+	return m, nil
+}
+
 // Pong is a response a Ping.
 //
 // It includes the sender's source IP + port, so it's effectively a
@@ -171,7 +215,7 @@ func MessageSummary(m Message) string {
 		return fmt.Sprintf("ping tx=%x", m.TxID[:6])
 	case *Pong:
 		return fmt.Sprintf("pong tx=%x", m.TxID[:6])
-	case CallMeMaybe:
+	case *CallMeMaybe:
 		return "call-me-maybe"
 	default:
 		return fmt.Sprintf("%#v", m)

disco/disco_test.go

@@ -44,9 +44,19 @@ func TestMarshalAndParse(t *testing.T) {
 		},
 		{
 			name: "call_me_maybe",
-			m:    CallMeMaybe{},
+			m:    &CallMeMaybe{},
 			want: "03 00",
 		},
+		{
+			name: "call_me_maybe_endpoints",
+			m: &CallMeMaybe{
+				MyNumber: []netaddr.IPPort{
+					netaddr.MustParseIPPort("1.2.3.4:567"),
+					netaddr.MustParseIPPort("[2001::3456]:789"),
+				},
+			},
+			want: "03 00 00 00 00 00 00 00 00 00 00 00 ff ff 01 02 03 04 02 37 20 01 00 00 00 00 00 00 00 00 00 00 00 00 34 56 03 15",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

go.mod

@@ -1,41 +1,47 @@
 module tailscale.com
 
-go 1.14
+go 1.16
 
 require (
 	github.com/alexbrainman/sspi v0.0.0-20180613141037-e580b900e9f5
 	github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239 // indirect
-	github.com/apenwarr/fixconsole v0.0.0-20191012055117-5a9f6489cc29
 	github.com/coreos/go-iptables v0.4.5
 	github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 // indirect
+	github.com/github/certstore v0.1.0
 	github.com/gliderlabs/ssh v0.2.2
 	github.com/go-multierror/multierror v1.0.2
 	github.com/go-ole/go-ole v1.2.4
 	github.com/godbus/dbus/v5 v5.0.3
-	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e
-	github.com/google/go-cmp v0.4.0
+	github.com/google/go-cmp v0.5.4
 	github.com/goreleaser/nfpm v1.1.10
-	github.com/jsimonetti/rtnetlink v0.0.0-20200117123717-f846d4f6c1f4
+	github.com/jsimonetti/rtnetlink v0.0.0-20210212075122-66c871082f2b
 	github.com/klauspost/compress v1.10.10
-	github.com/kr/pty v1.1.1
-	github.com/mdlayher/netlink v1.1.0
+	github.com/kr/pty v1.1.8
+	github.com/mdlayher/netlink v1.3.2
+	github.com/mdlayher/sdnotify v0.0.0-20200625151349-e4a4f32afc4a
 	github.com/miekg/dns v1.1.30
 	github.com/pborman/getopt v0.0.0-20190409184431-ee0cd42419d3
 	github.com/peterbourgon/ff/v2 v2.0.0
-	github.com/tailscale/depaware v0.0.0-20201003033024-5d95aab075be
-	github.com/tailscale/wireguard-go v0.0.0-20201021041318-a6168fd06b3f
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/tailscale/depaware v0.0.0-20201214215404-77d1e9757027
+	github.com/tailscale/wireguard-go v0.0.0-20210327173134-f6a42a1646a0
 	github.com/tcnksm/go-httpstat v0.2.0
 	github.com/toqueteos/webbrowser v1.2.0
-	go4.org/mem v0.0.0-20200706164138-185c595c3ecc
-	golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899
-	golang.org/x/net v0.0.0-20200822124328-c89045814202
-	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
-	golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208
-	golang.org/x/sys v0.0.0-20200812155832-6a926be9bd1d
-	golang.org/x/time v0.0.0-20191024005414-555d28b269f0
-	golang.org/x/tools v0.0.0-20201002184944-ecd9fd270d5d
-	golang.zx2c4.com/wireguard/windows v0.1.2-0.20201004085714-dd60d0447f81
-	honnef.co/go/tools v0.0.1-2020.1.4
-	inet.af/netaddr v0.0.0-20200810144936-56928fe48a98
+	go4.org/mem v0.0.0-20201119185036-c04c5a6ff174
+	golang.org/x/crypto v0.0.0-20210317152858-513c2a44f670
+	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110
+	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
+	golang.org/x/sys v0.0.0-20210317225723-c4fcb01b228e
+	golang.org/x/term v0.0.0-20210317153231-de623e64d2a6
+	golang.org/x/time v0.0.0-20210220033141-f8bda1e9f3ba
+	golang.org/x/tools v0.0.0-20201211185031-d93e913c1a58
+	golang.zx2c4.com/wireguard/windows v0.1.2-0.20201113162609-9b85be97fdf8
+	gopkg.in/yaml.v2 v2.2.8 // indirect
+	honnef.co/go/tools v0.1.0
+	inet.af/netaddr v0.0.0-20210222205655-a1ec2b7b8c44
+	inet.af/netstack v0.0.0-20210317161235-a1bf4e56ef22
+	inet.af/peercred v0.0.0-20210302202138-56e694897155
 	rsc.io/goversion v1.2.0
 )
+
+replace github.com/github/certstore => github.com/cyolosecurity/certstore v0.0.0-20200922073901-ece7f1d353c2

go.sum

@@ -1,4 +1,3 @@
-cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/Masterminds/semver/v3 v3.0.3 h1:znjIyLfpXEDQjOIEWh+ehwpTU14UzUPub3c3sm36u14=
@@ -10,21 +9,24 @@ github.com/alexbrainman/sspi v0.0.0-20180613141037-e580b900e9f5 h1:P5U+E4x5OkVEK
 github.com/alexbrainman/sspi v0.0.0-20180613141037-e580b900e9f5/go.mod h1:976q2ETgjT2snVCf2ZaBnyBbVoPERGjUz+0sofzEfro=
 github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239 h1:kFOfPq6dUM1hTo4JG6LR5AXSUEsOjtdm0kw0FtQtMJA=
 github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239/go.mod h1:2FmKhYUyUczH0OGQWaF5ceTx0UBShxjsH6f8oGKYe2c=
-github.com/apenwarr/fixconsole v0.0.0-20191012055117-5a9f6489cc29 h1:muXWUcay7DDy1/hEQWrYlBy+g0EuwT70sBHg65SeUc4=
-github.com/apenwarr/fixconsole v0.0.0-20191012055117-5a9f6489cc29/go.mod h1:JYWahgHer+Z2xbsgHPtaDYVWzeHDminu+YIBWkxpCAY=
-github.com/apenwarr/w32 v0.0.0-20190407065021-aa00fece76ab h1:CMGzRRCjnD50RjUFSArBLuCxiDvdp7b8YPAcikBEQ+k=
-github.com/apenwarr/w32 v0.0.0-20190407065021-aa00fece76ab/go.mod h1:nfFtvHn2Hgs9G1u0/J6LHQv//EksNC+7G8vXmd1VTJ8=
 github.com/blakesmith/ar v0.0.0-20190502131153-809d4375e1fb h1:m935MPodAbYS46DG4pJSv7WO+VECIWUQ7OJYSoTrMh4=
 github.com/blakesmith/ar v0.0.0-20190502131153-809d4375e1fb/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
 github.com/cavaliercoder/go-cpio v0.0.0-20180626203310-925f9528c45e h1:hHg27A0RSSp2Om9lubZpiMgVbvn39bsUmW9U5h0twqc=
 github.com/cavaliercoder/go-cpio v0.0.0-20180626203310-925f9528c45e/go.mod h1:oDpT4efm8tSYHXV5tHSdRvBet/b/QzxZ+XyyPehvm3A=
 github.com/coreos/go-iptables v0.4.5 h1:DpHb9vJrZQEFMcVLFKAAGMUVX0XoRC0ptCthinRYm38=
 github.com/coreos/go-iptables v0.4.5/go.mod h1:/mVI274lEDI2ns62jHCDnCyBF9Iwsmekav8Dbxlm1MU=
+github.com/creack/pty v1.1.7 h1:6pwm8kMQKCmgUg0ZHTm5+/YvRK0s3THD/28+T6/kk4A=
+github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
+github.com/cyolosecurity/certstore v0.0.0-20200922073901-ece7f1d353c2 h1:TGPWAij+nY2FB7TlyUTqTmYvXJon/AZAfRMYc/76K80=
+github.com/cyolosecurity/certstore v0.0.0-20200922073901-ece7f1d353c2/go.mod h1:Sgb3YVYOB2iCO06NJ6We5gjXe7uxxM3zPYoEXjuTKno=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dvyukov/go-fuzz v0.0.0-20201127111758-49e582c6c23d/go.mod h1:11Gm+ccJnvAhCNLlf5+cS9KjtbaD5I5zaZpFMsTHWTw=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 h1:BHsljHzVlRcyQhjrss6TZTdY2VfCqZPbv5k3iBFa2ZQ=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
+github.com/github/fakeca v0.1.0 h1:Km/MVOFvclqxPM9dZBC4+QE564nU4gz4iZ0D9pMw28I=
+github.com/github/fakeca v0.1.0/go.mod h1:+bormgoGMMuamOscx7N91aOuUST7wdaJ2rNjeohylyo=
 github.com/gliderlabs/ssh v0.2.2 h1:6zsha5zo/TWhRhwqCD3+EarCAgZ2yN28ipRnGPnwkI0=
 github.com/gliderlabs/ssh v0.2.2/go.mod h1:U7qILu1NlMHj9FlMhZLlkCdDnU1DBEAqr0aevW3Awn0=
 github.com/go-multierror/multierror v1.0.2 h1:AwsKbEXkmf49ajdFJgcFXqSG0aLo0HEyAE9zk9JguJo=
@@ -33,14 +35,15 @@ github.com/go-ole/go-ole v1.2.4 h1:nNBDSCOigTSiarFpYE9J/KtEA1IOW4CNeqT9TQDqCxI=
 github.com/go-ole/go-ole v1.2.4/go.mod h1:XCwSNxSkXRo4vlyPy93sltvi/qJq0jqQhjqQNIwKuxM=
 github.com/godbus/dbus/v5 v5.0.3 h1:ZqHaoEF7TBzh4jzPmqVhE/5A1z9of6orkAe5uHoAeME=
 github.com/godbus/dbus/v5 v5.0.3/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
-github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e h1:1r7pUrabqp18hOBcwBwiTsbnFeTZHV9eER/QT5JVZxY=
-github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
-github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
-github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/btree v1.0.1 h1:gK4Kx5IaGY9CD5sPJ36FHiBJ6ZXl0kilRiiCj+jdYp4=
+github.com/google/btree v1.0.1/go.mod h1:xXMiIv4Fb/0kKde4SpL7qlzvu5cMJDRkFDxJfI9uaxA=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
-github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.4 h1:L8R9j+yAqZuZjsqh/z+F1NCffTKKLShY6zXTItVIZ8M=
+github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/google/rpmpack v0.0.0-20191226140753-aa36bfddb3a0 h1:BW6OvS3kpT5UEPbCZ+KyX/OB4Ks9/MNMhWjqPPkZxsE=
 github.com/google/rpmpack v0.0.0-20191226140753-aa36bfddb3a0/go.mod h1:RaTPr0KUf2K7fnZYLNDrr8rxAamWs3iNywJLtQ2AzBg=
@@ -48,26 +51,46 @@ github.com/goreleaser/nfpm v1.1.10 h1:0nwzKUJTcygNxTzVKq2Dh9wpVP1W2biUH6SNKmoxR3
 github.com/goreleaser/nfpm v1.1.10/go.mod h1:oOcoGRVwvKIODz57NUfiRwFWGfn00NXdgnn6MrYtO5k=
 github.com/imdario/mergo v0.3.8 h1:CGgOkSJeqMRmt0D9XLWExdT4m4F1vd3FV3VPt+0VxkQ=
 github.com/imdario/mergo v0.3.8/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
+github.com/josharian/native v0.0.0-20200817173448-b6b71def0850 h1:uhL5Gw7BINiiPAo24A2sxkcDI0Jt/sqp1v5xQCniEFA=
+github.com/josharian/native v0.0.0-20200817173448-b6b71def0850/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
 github.com/jsimonetti/rtnetlink v0.0.0-20190606172950-9527aa82566a/go.mod h1:Oz+70psSo5OFh8DBl0Zv2ACw7Esh6pPUphlvZG9x7uw=
-github.com/jsimonetti/rtnetlink v0.0.0-20200117123717-f846d4f6c1f4 h1:nwOc1YaOrYJ37sEBrtWZrdqzK22hiJs3GpDmP3sR2Yw=
 github.com/jsimonetti/rtnetlink v0.0.0-20200117123717-f846d4f6c1f4/go.mod h1:WGuG/smIU4J/54PblvSbh+xvCZmpJnFgr3ds6Z55XMQ=
+github.com/jsimonetti/rtnetlink v0.0.0-20201009170750-9c6f07d100c1/go.mod h1:hqoO/u39cqLeBLebZ8fWdE96O7FxrAsRYhnVOdgHxok=
+github.com/jsimonetti/rtnetlink v0.0.0-20201216134343-bde56ed16391/go.mod h1:cR77jAZG3Y3bsb8hF6fHJbFoyFukLFOkQ98S0pQz3xw=
+github.com/jsimonetti/rtnetlink v0.0.0-20201220180245-69540ac93943/go.mod h1:z4c53zj6Eex712ROyh8WI0ihysb5j2ROyV42iNogmAs=
+github.com/jsimonetti/rtnetlink v0.0.0-20210122163228-8d122574c736/go.mod h1:ZXpIyOK59ZnN7J0BV99cZUPmsqDRZ3eq5X+st7u/oSA=
+github.com/jsimonetti/rtnetlink v0.0.0-20210212075122-66c871082f2b h1:c3NTyLNozICy8B4mlMXemD3z/gXgQzVXZS/HqT+i3do=
+github.com/jsimonetti/rtnetlink v0.0.0-20210212075122-66c871082f2b/go.mod h1:8w9Rh8m+aHZIG69YPGGem1i5VzoyRC8nw2kA8B+ik5U=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/klauspost/compress v1.10.10 h1:a/y8CglcM7gLGYmlbP/stPE5sR3hbhFRUjCBfd/0B3I=
 github.com/klauspost/compress v1.10.10/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
-github.com/kr/pty v1.1.1 h1:VkoXIwSboBpnk99O/KFauAEILuNHv5DVFKZMBN/gUgw=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/pty v1.1.8 h1:AkaSdXYQOWeaO3neb8EM634ahkXXe3jYbVh/F9lq+GI=
+github.com/kr/pty v1.1.8/go.mod h1:O1sed60cT9XZ5uDucP5qwvh+TE3NnUj51EiZO/lmSfw=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/lxn/walk v0.0.0-20191128110447-55ccb3a9f5c1/go.mod h1:E23UucZGqpuUANJooIbHWCufXvOcT6E7Stq81gU+CSQ=
-github.com/lxn/win v0.0.0-20191128105842-2da648fda5b4/go.mod h1:ouWl4wViUNh8tPSIwxTVMuS014WakR1hqvBc2I0bMoA=
+github.com/lxn/walk v0.0.0-20201110160827-18ea5e372cdb/go.mod h1:E23UucZGqpuUANJooIbHWCufXvOcT6E7Stq81gU+CSQ=
+github.com/lxn/win v0.0.0-20201111105847-2a20daff6a55/go.mod h1:KxxjdtRkfNoYDCUP5ryK7XJJNTnpC8atvtmTheChOtk=
 github.com/mattn/go-zglob v0.0.1 h1:xsEx/XUoVlI6yXjqBK062zYhRTZltCNmYPx6v+8DNaY=
 github.com/mattn/go-zglob v0.0.1/go.mod h1:9fxibJccNxU2cnpIKLRRFA7zX7qhkJIQWBb449FYHOo=
+github.com/mdlayher/ethtool v0.0.0-20210210192532-2b88debcdd43 h1:WgyLFv10Ov49JAQI/ZLUkCZ7VJS3r74hwFIGXJsgZlY=
+github.com/mdlayher/ethtool v0.0.0-20210210192532-2b88debcdd43/go.mod h1:+t7E0lkKfbBsebllff1xdTmyJt8lH37niI6kwFk9OTo=
+github.com/mdlayher/genetlink v1.0.0 h1:OoHN1OdyEIkScEmRgxLEe2M9U8ClMytqA5niynLtfj0=
+github.com/mdlayher/genetlink v1.0.0/go.mod h1:0rJ0h4itni50A86M2kHcgS85ttZazNt7a8H2a2cw0Gc=
 github.com/mdlayher/netlink v0.0.0-20190409211403-11939a169225/go.mod h1:eQB3mZE4aiYnlUsyGGCOpPETfdQq4Jhsgf1fk3cwQaA=
 github.com/mdlayher/netlink v1.0.0/go.mod h1:KxeJAFOFLG6AjpyDkQ/iIhxygIUKD+vcwqcnu43w/+M=
-github.com/mdlayher/netlink v1.1.0 h1:mpdLgm+brq10nI9zM1BpX1kpDbh3NLl3RSnVq6ZSkfg=
 github.com/mdlayher/netlink v1.1.0/go.mod h1:H4WCitaheIsdF9yOYu8CFmCgQthAPIWZmcKp9uZHgmY=
+github.com/mdlayher/netlink v1.1.1/go.mod h1:WTYpFb/WTvlRJAyKhZL5/uy69TDDpHHu2VZmb2XgV7o=
+github.com/mdlayher/netlink v1.2.0/go.mod h1:kwVW1io0AZy9A1E2YYgaD4Cj+C+GPkU6klXCMzIJ9p8=
+github.com/mdlayher/netlink v1.2.1/go.mod h1:bacnNlfhqHqqLo4WsYeXSqfyXkInQ9JneWI68v1KwSU=
+github.com/mdlayher/netlink v1.2.2-0.20210123213345-5cc92139ae3e/go.mod h1:bacnNlfhqHqqLo4WsYeXSqfyXkInQ9JneWI68v1KwSU=
+github.com/mdlayher/netlink v1.3.0/go.mod h1:xK/BssKuwcRXHrtN04UBkwQ6dY9VviGGuriDdoPSWys=
+github.com/mdlayher/netlink v1.3.2 h1:fMZOU2/M7PRMzGM3br5l1N2fu6bPSHtRytmQ338a9iA=
+github.com/mdlayher/netlink v1.3.2/go.mod h1:dRJi5IABcZpBD2A3D0Mv/AiX8I9uDEu5oGkAVrekmf8=
+github.com/mdlayher/sdnotify v0.0.0-20200625151349-e4a4f32afc4a h1:wMv2mvcHRH4jqIxaVL5t6gSq1hjPiaWH7TOcA0Z+uNo=
+github.com/mdlayher/sdnotify v0.0.0-20200625151349-e4a4f32afc4a/go.mod h1:HtjVsQfsrBm1GDcDTUFn4ZXhftxTwO/hxrvEiRc61U4=
 github.com/miekg/dns v1.1.30 h1:Qww6FseFn8PRfw07jueqIXqodm0JKiiKuK0DeXSqfyo=
 github.com/miekg/dns v1.1.30/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
 github.com/op/go-logging v0.0.0-20160315200505-970db520ece7 h1:lDH9UUVJtmYCjyT0CI4q8xvlXPxeZ0gYCVvWbmPlp88=
@@ -79,8 +102,9 @@ github.com/peterbourgon/ff/v2 v2.0.0 h1:lx0oYI5qr/FU1xnpNhQ+EZM04gKgn46jyYvGEEqB
 github.com/peterbourgon/ff/v2 v2.0.0/go.mod h1:xjwr+t+SjWm4L46fcj/D+Ap+6ME7+HqFzaP22pP5Ggk=
 github.com/pkg/diff v0.0.0-20200914180035-5b29258ca4f7 h1:+/+DxvQaYifJ+grD4klzrS5y+KJXldn/2YTl5JG+vZ8=
 github.com/pkg/diff v0.0.0-20200914180035-5b29258ca4f7/go.mod h1:zO8QMzTeZd5cpnIkz/Gn6iK0jDfGicM1nynOkkPIl28=
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@@ -190,11 +239,16 @@ gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8
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health/health.go

@@ -0,0 +1,268 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package health is a registry for other packages to report & check
+// overall health status of the node.
+package health
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"sync"
+	"time"
+
+	"github.com/go-multierror/multierror"
+	"tailscale.com/tailcfg"
+)
+
+var (
+	// mu guards everything in this var block.
+	mu sync.Mutex
+
+	sysErr   = map[Subsystem]error{}                     // error key => err (or nil for no error)
+	watchers = map[*watchHandle]func(Subsystem, error){} // opt func to run if error state changes
+	timer    *time.Timer
+
+	inMapPoll               bool
+	inMapPollSince          time.Time
+	lastMapPollEndedAt      time.Time
+	lastStreamedMapResponse time.Time
+	derpHomeRegion          int
+	derpRegionConnected     = map[int]bool{}
+	derpRegionLastFrame     = map[int]time.Time{}
+	lastMapRequestHeard     time.Time // time we got a 200 from control for a MapRequest
+	ipnState                string
+	ipnWantRunning          bool
+	anyInterfaceUp          = true // until told otherwise
+)
+
+// Subsystem is the name of a subsystem whose health can be monitored.
+type Subsystem string
+
+const (
+	// SysOverall is the name representing the overall health of
+	// the system, rather than one particular subsystem.
+	SysOverall = Subsystem("overall")
+
+	// SysRouter is the name the wgengine/router subsystem.
+	SysRouter = Subsystem("router")
+
+	// SysNetworkCategory is the name of the subsystem that sets
+	// the Windows network adapter's "category" (public, private, domain).
+	// If it's unhealthy, the Windows firewall rules won't match.
+	SysNetworkCategory = Subsystem("network-category")
+)
+
+type watchHandle byte
+
+// RegisterWatcher adds a function that will be called if an
+// error changes state either to unhealthy or from unhealthy. It is
+// not called on transition from unknown to healthy. It must be non-nil
+// and is run in its own goroutine. The returned func unregisters it.
+func RegisterWatcher(cb func(key Subsystem, err error)) (unregister func()) {
+	mu.Lock()
+	defer mu.Unlock()
+	handle := new(watchHandle)
+	watchers[handle] = cb
+	if timer == nil {
+		timer = time.AfterFunc(time.Minute, timerSelfCheck)
+	}
+	return func() {
+		mu.Lock()
+		defer mu.Unlock()
+		delete(watchers, handle)
+		if len(watchers) == 0 && timer != nil {
+			timer.Stop()
+			timer = nil
+		}
+	}
+}
+
+// SetRouter sets the state of the wgengine/router.Router.
+func SetRouterHealth(err error) { set(SysRouter, err) }
+
+// RouterHealth returns the wgengine/router.Router error state.
+func RouterHealth() error { return get(SysRouter) }
+
+// SetNetworkCategoryHealth sets the state of setting the network adaptor's category.
+// This only applies on Windows.
+func SetNetworkCategoryHealth(err error) { set(SysNetworkCategory, err) }
+
+func NetworkCategoryHealth() error { return get(SysNetworkCategory) }
+
+func get(key Subsystem) error {
+	mu.Lock()
+	defer mu.Unlock()
+	return sysErr[key]
+}
+
+func set(key Subsystem, err error) {
+	mu.Lock()
+	defer mu.Unlock()
+	setLocked(key, err)
+}
+
+func setLocked(key Subsystem, err error) {
+	old, ok := sysErr[key]
+	if !ok && err == nil {
+		// Initial happy path.
+		sysErr[key] = nil
+		selfCheckLocked()
+		return
+	}
+	if ok && (old == nil) == (err == nil) {
+		// No change in overall error status (nil-vs-not), so
+		// don't run callbacks, but exact error might've
+		// changed, so note it.
+		if err != nil {
+			sysErr[key] = err
+		}
+		return
+	}
+	sysErr[key] = err
+	selfCheckLocked()
+	for _, cb := range watchers {
+		go cb(key, err)
+	}
+}
+
+// GotStreamedMapResponse notes that we got a tailcfg.MapResponse
+// message in streaming mode, even if it's just a keep-alive message.
+func GotStreamedMapResponse() {
+	mu.Lock()
+	defer mu.Unlock()
+	lastStreamedMapResponse = time.Now()
+	selfCheckLocked()
+}
+
+// SetInPollNetMap records that we're in
+func SetInPollNetMap(v bool) {
+	mu.Lock()
+	defer mu.Unlock()
+	if v == inMapPoll {
+		return
+	}
+	inMapPoll = v
+	if v {
+		inMapPollSince = time.Now()
+	} else {
+		lastMapPollEndedAt = time.Now()
+	}
+}
+
+// SetMagicSockDERPHome notes what magicsock's view of its home DERP is.
+func SetMagicSockDERPHome(region int) {
+	mu.Lock()
+	defer mu.Unlock()
+	derpHomeRegion = region
+	selfCheckLocked()
+}
+
+// NoteMapRequestHeard notes whenever we successfully sent a map request
+// to control for which we received a 200 response.
+func NoteMapRequestHeard(mr *tailcfg.MapRequest) {
+	mu.Lock()
+	defer mu.Unlock()
+	// TODO: extract mr.HostInfo.NetInfo.PreferredDERP, compare
+	// against SetMagicSockDERPHome and
+	// SetDERPRegionConnectedState
+
+	lastMapRequestHeard = time.Now()
+	selfCheckLocked()
+}
+
+func SetDERPRegionConnectedState(region int, connected bool) {
+	mu.Lock()
+	defer mu.Unlock()
+	derpRegionConnected[region] = connected
+	selfCheckLocked()
+}
+
+func NoteDERPRegionReceivedFrame(region int) {
+	mu.Lock()
+	defer mu.Unlock()
+	derpRegionLastFrame[region] = time.Now()
+	selfCheckLocked()
+}
+
+// state is an ipn.State.String() value: "Running", "Stopped", "NeedsLogin", etc.
+func SetIPNState(state string, wantRunning bool) {
+	mu.Lock()
+	defer mu.Unlock()
+	ipnState = state
+	ipnWantRunning = wantRunning
+	selfCheckLocked()
+}
+
+// SetAnyInterfaceUp sets whether any network interface is up.
+func SetAnyInterfaceUp(up bool) {
+	mu.Lock()
+	defer mu.Unlock()
+	anyInterfaceUp = up
+	selfCheckLocked()
+}
+
+func timerSelfCheck() {
+	mu.Lock()
+	defer mu.Unlock()
+	selfCheckLocked()
+	if timer != nil {
+		timer.Reset(time.Minute)
+	}
+}
+
+func selfCheckLocked() {
+	if ipnState == "" {
+		// Don't check yet.
+		return
+	}
+	setLocked(SysOverall, overallErrorLocked())
+}
+
+func overallErrorLocked() error {
+	if !anyInterfaceUp {
+		return errors.New("network down")
+	}
+	if ipnState != "Running" || !ipnWantRunning {
+		return fmt.Errorf("state=%v, wantRunning=%v", ipnState, ipnWantRunning)
+	}
+	now := time.Now()
+	if !inMapPoll && (lastMapPollEndedAt.IsZero() || now.Sub(lastMapPollEndedAt) > 10*time.Second) {
+		return errors.New("not in map poll")
+	}
+	const tooIdle = 2*time.Minute + 5*time.Second
+	if d := now.Sub(lastStreamedMapResponse).Round(time.Second); d > tooIdle {
+		return fmt.Errorf("no map response in %v", d)
+	}
+	rid := derpHomeRegion
+	if rid == 0 {
+		return errors.New("no DERP home")
+	}
+	if !derpRegionConnected[rid] {
+		return fmt.Errorf("not connected to home DERP region %v", rid)
+	}
+	if d := now.Sub(derpRegionLastFrame[rid]).Round(time.Second); d > tooIdle {
+		return fmt.Errorf("haven't heard from home DERP region %v in %v", rid, d)
+	}
+
+	// TODO: use
+	_ = inMapPollSince
+	_ = lastMapPollEndedAt
+	_ = lastStreamedMapResponse
+	_ = lastMapRequestHeard
+
+	var errs []error
+	for sys, err := range sysErr {
+		if err == nil || sys == SysOverall {
+			continue
+		}
+		errs = append(errs, fmt.Errorf("%v: %w", sys, err))
+	}
+	sort.Slice(errs, func(i, j int) bool {
+		// Not super efficient (stringifying these in a sort), but probably max 2 or 3 items.
+		return errs[i].Error() < errs[j].Error()
+	})
+	return multierror.New(errs)
+}

internal/deepprint/deepprint_test.go

@@ -8,10 +8,10 @@ import (
 	"bytes"
 	"testing"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
 	"inet.af/netaddr"
+	"tailscale.com/net/dns"
 	"tailscale.com/wgengine/router"
-	"tailscale.com/wgengine/router/dns"
+	"tailscale.com/wgengine/wgcfg"
 )
 
 func TestDeepPrint(t *testing.T) {
@@ -37,16 +37,11 @@ func getVal() []interface{} {
 	return []interface{}{
 		&wgcfg.Config{
 			Name:       "foo",
-			Addresses:  []wgcfg.CIDR{{Mask: 5, IP: wgcfg.IP{Addr: [16]byte{3: 3}}}},
+			Addresses:  []netaddr.IPPrefix{{Bits: 5, IP: netaddr.IPFrom16([16]byte{3: 3})}},
 			ListenPort: 5,
 			Peers: []wgcfg.Peer{
 				{
-					Endpoints: []wgcfg.Endpoint{
-						{
-							Host: "foo",
-							Port: 5,
-						},
-					},
+					Endpoints: "foo:5",
 				},
 			},
 		},

ipn/backend.go

@@ -8,13 +8,11 @@ import (
 	"net/http"
 	"time"
 
-	"golang.org/x/oauth2"
-	"tailscale.com/control/controlclient"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/empty"
+	"tailscale.com/types/netmap"
 	"tailscale.com/types/structs"
-	"tailscale.com/wgengine"
 )
 
 type State int
@@ -29,7 +27,7 @@ const (
 	Running
 )
 
-// GoogleIDToken Type is the oauth2.Token.TokenType for the Google
+// GoogleIDToken Type is the tailcfg.Oauth2Token.TokenType for the Google
 // ID tokens used by the Android client.
 const GoogleIDTokenType = "ts_android_google_login"
 
@@ -46,10 +44,10 @@ func (s State) String() string {
 
 // EngineStatus contains WireGuard engine stats.
 type EngineStatus struct {
-	RBytes, WBytes wgengine.ByteCount
+	RBytes, WBytes int64
 	NumLive        int
 	LiveDERPs      int // number of active DERP connections
-	LivePeers      map[tailcfg.NodeKey]wgengine.PeerStatus
+	LivePeers      map[tailcfg.NodeKey]ipnstate.PeerStatusLite
 }
 
 // Notify is a communication from a backend (e.g. tailscaled) to a frontend
@@ -59,16 +57,15 @@ type EngineStatus struct {
 // They are JSON-encoded on the wire, despite the lack of struct tags.
 type Notify struct {
 	_             structs.Incomparable
-	Version       string                    // version number of IPN backend
-	ErrMessage    *string                   // critical error message, if any; for InUseOtherUser, the details
-	LoginFinished *empty.Message            // event: non-nil when login process succeeded
-	State         *State                    // current IPN state has changed
-	Prefs         *Prefs                    // preferences were changed
-	NetMap        *controlclient.NetworkMap // new netmap received
-	Engine        *EngineStatus             // wireguard engine stats
-	Status        *ipnstate.Status          // full status
-	BrowseToURL   *string                   // UI should open a browser right now
-	BackendLogID  *string                   // public logtail id used by backend
+	Version       string             // version number of IPN backend
+	ErrMessage    *string            // critical error message, if any; for InUseOtherUser, the details
+	LoginFinished *empty.Message     // event: non-nil when login process succeeded
+	State         *State             // current IPN state has changed
+	Prefs         *Prefs             // preferences were changed
+	NetMap        *netmap.NetworkMap // new netmap received
+	Engine        *EngineStatus      // wireguard engine stats
+	BrowseToURL   *string            // UI should open a browser right now
+	BackendLogID  *string            // public logtail id used by backend
 	PingResult    *ipnstate.PingResult
 
 	// LocalTCPPort, if non-nil, informs the UI frontend which
@@ -144,7 +141,7 @@ type Backend interface {
 	// eventually.
 	StartLoginInteractive()
 	// Login logs in with an OAuth2 token.
-	Login(token *oauth2.Token)
+	Login(token *tailcfg.Oauth2Token)
 	// Logout terminates the current login session and stops the
 	// wireguard engine.
 	Logout()
@@ -160,9 +157,6 @@ type Backend interface {
 	// counts. Connection events are emitted automatically without
 	// polling.
 	RequestEngineStatus()
-	// RequestStatus requests that a full Status update
-	// notification is sent.
-	RequestStatus()
 	// FakeExpireAfter pretends that the current key is going to
 	// expire after duration x. This is useful for testing GUIs to
 	// make sure they react properly with keys that are going to
@@ -171,5 +165,5 @@ type Backend interface {
 	// Ping attempts to start connecting to the given IP and sends a Notify
 	// with its PingResult. If the host is down, there might never
 	// be a PingResult sent. The cmd/tailscale CLI client adds a timeout.
-	Ping(ip string)
+	Ping(ip string, useTSMP bool)
 }

ipn/fake_test.go

@@ -8,9 +8,9 @@ import (
 	"log"
 	"time"
 
-	"golang.org/x/oauth2"
-	"tailscale.com/control/controlclient"
 	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/netmap"
 )
 
 type FakeBackend struct {
@@ -46,7 +46,7 @@ func (b *FakeBackend) StartLoginInteractive() {
 	b.login()
 }
 
-func (b *FakeBackend) Login(token *oauth2.Token) {
+func (b *FakeBackend) Login(token *tailcfg.Oauth2Token) {
 	b.login()
 }
 
@@ -54,7 +54,7 @@ func (b *FakeBackend) login() {
 	b.newState(NeedsMachineAuth)
 	b.newState(Stopped)
 	// TODO(apenwarr): Fill in a more interesting netmap here.
-	b.notify(Notify{NetMap: &controlclient.NetworkMap{}})
+	b.notify(Notify{NetMap: &netmap.NetworkMap{}})
 	b.newState(Starting)
 	// TODO(apenwarr): Fill in a more interesting status.
 	b.notify(Notify{Engine: &EngineStatus{}})
@@ -87,14 +87,10 @@ func (b *FakeBackend) RequestEngineStatus() {
 	b.notify(Notify{Engine: &EngineStatus{}})
 }
 
-func (b *FakeBackend) RequestStatus() {
-	b.notify(Notify{Status: &ipnstate.Status{}})
-}
-
 func (b *FakeBackend) FakeExpireAfter(x time.Duration) {
-	b.notify(Notify{NetMap: &controlclient.NetworkMap{}})
+	b.notify(Notify{NetMap: &netmap.NetworkMap{}})
 }
 
-func (b *FakeBackend) Ping(ip string) {
+func (b *FakeBackend) Ping(ip string, useTSMP bool) {
 	b.notify(Notify{PingResult: &ipnstate.PingResult{}})
 }

ipn/handle.go

@@ -8,10 +8,10 @@ import (
 	"sync"
 	"time"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
-	"golang.org/x/oauth2"
-	"tailscale.com/control/controlclient"
+	"inet.af/netaddr"
+	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
+	"tailscale.com/types/netmap"
 )
 
 type Handle struct {
@@ -22,7 +22,7 @@ type Handle struct {
 
 	// Mutex protects everything below
 	mu                sync.Mutex
-	netmapCache       *controlclient.NetworkMap
+	netmapCache       *netmap.NetworkMap
 	engineStatusCache EngineStatus
 	stateCache        State
 	prefsCache        *Prefs
@@ -118,7 +118,7 @@ func (h *Handle) EngineStatus() EngineStatus {
 	return h.engineStatusCache
 }
 
-func (h *Handle) LocalAddrs() []wgcfg.CIDR {
+func (h *Handle) LocalAddrs() []netaddr.IPPrefix {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
@@ -126,10 +126,10 @@ func (h *Handle) LocalAddrs() []wgcfg.CIDR {
 	if nm != nil {
 		return nm.Addresses
 	}
-	return []wgcfg.CIDR{}
+	return []netaddr.IPPrefix{}
 }
 
-func (h *Handle) NetMap() *controlclient.NetworkMap {
+func (h *Handle) NetMap() *netmap.NetworkMap {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
@@ -155,7 +155,7 @@ func (h *Handle) StartLoginInteractive() {
 	h.b.StartLoginInteractive()
 }
 
-func (h *Handle) Login(token *oauth2.Token) {
+func (h *Handle) Login(token *tailcfg.Oauth2Token) {
 	h.b.Login(token)
 }
 
@@ -167,10 +167,6 @@ func (h *Handle) RequestEngineStatus() {
 	h.b.RequestEngineStatus()
 }
 
-func (h *Handle) RequestStatus() {
-	h.b.RequestStatus()
-}
-
 func (h *Handle) FakeExpireAfter(x time.Duration) {
 	h.b.FakeExpireAfter(x)
 }

ipn/ipnlocal/local_test.go

@@ -0,0 +1,293 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ipnlocal
+
+import (
+	"reflect"
+	"testing"
+
+	"inet.af/netaddr"
+	"tailscale.com/net/interfaces"
+	"tailscale.com/net/tsaddr"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/netmap"
+	"tailscale.com/wgengine/wgcfg"
+)
+
+func TestNetworkMapCompare(t *testing.T) {
+	prefix1, err := netaddr.ParseIPPrefix("192.168.0.0/24")
+	if err != nil {
+		t.Fatal(err)
+	}
+	node1 := &tailcfg.Node{Addresses: []netaddr.IPPrefix{prefix1}}
+
+	prefix2, err := netaddr.ParseIPPrefix("10.0.0.0/8")
+	if err != nil {
+		t.Fatal(err)
+	}
+	node2 := &tailcfg.Node{Addresses: []netaddr.IPPrefix{prefix2}}
+
+	tests := []struct {
+		name string
+		a, b *netmap.NetworkMap
+		want bool
+	}{
+		{
+			"both nil",
+			nil,
+			nil,
+			true,
+		},
+		{
+			"b nil",
+			&netmap.NetworkMap{},
+			nil,
+			false,
+		},
+		{
+			"a nil",
+			nil,
+			&netmap.NetworkMap{},
+			false,
+		},
+		{
+			"both default",
+			&netmap.NetworkMap{},
+			&netmap.NetworkMap{},
+			true,
+		},
+		{
+			"names identical",
+			&netmap.NetworkMap{Name: "map1"},
+			&netmap.NetworkMap{Name: "map1"},
+			true,
+		},
+		{
+			"names differ",
+			&netmap.NetworkMap{Name: "map1"},
+			&netmap.NetworkMap{Name: "map2"},
+			false,
+		},
+		{
+			"Peers identical",
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{}},
+			true,
+		},
+		{
+			"Peer list length",
+			// length of Peers list differs
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{{}}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{}},
+			false,
+		},
+		{
+			"Node names identical",
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{&tailcfg.Node{Name: "A"}}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{&tailcfg.Node{Name: "A"}}},
+			true,
+		},
+		{
+			"Node names differ",
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{&tailcfg.Node{Name: "A"}}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{&tailcfg.Node{Name: "B"}}},
+			false,
+		},
+		{
+			"Node lists identical",
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{node1, node1}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{node1, node1}},
+			true,
+		},
+		{
+			"Node lists differ",
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{node1, node1}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{node1, node2}},
+			false,
+		},
+		{
+			"Node Users differ",
+			// User field is not checked.
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{&tailcfg.Node{User: 0}}},
+			&netmap.NetworkMap{Peers: []*tailcfg.Node{&tailcfg.Node{User: 1}}},
+			true,
+		},
+	}
+	for _, tt := range tests {
+		got := dnsMapsEqual(tt.a, tt.b)
+		if got != tt.want {
+			t.Errorf("%s: Equal = %v; want %v", tt.name, got, tt.want)
+		}
+	}
+}
+
+func inRemove(ip netaddr.IP) bool {
+	for _, pfx := range removeFromDefaultRoute {
+		if pfx.Contains(ip) {
+			return true
+		}
+	}
+	return false
+}
+
+func TestShrinkDefaultRoute(t *testing.T) {
+	tests := []struct {
+		route     string
+		in        []string
+		out       []string
+		localIPFn func(netaddr.IP) bool // true if this machine's local IP address should be "in" after shrinking.
+	}{
+		{
+			route: "0.0.0.0/0",
+			in:    []string{"1.2.3.4", "25.0.0.1"},
+			out: []string{
+				"10.0.0.1",
+				"10.255.255.255",
+				"192.168.0.1",
+				"192.168.255.255",
+				"172.16.0.1",
+				"172.31.255.255",
+				"100.101.102.103",
+				"224.0.0.1",
+				"169.254.169.254",
+				// Some random IPv6 stuff that shouldn't be in a v4
+				// default route.
+				"fe80::",
+				"2601::1",
+			},
+			localIPFn: func(ip netaddr.IP) bool { return !inRemove(ip) && ip.Is4() },
+		},
+		{
+			route: "::/0",
+			in:    []string{"::1", "2601::1"},
+			out: []string{
+				"fe80::1",
+				"ff00::1",
+				tsaddr.TailscaleULARange().IP.String(),
+			},
+			localIPFn: func(ip netaddr.IP) bool { return !inRemove(ip) && ip.Is6() },
+		},
+	}
+
+	for _, test := range tests {
+		def := netaddr.MustParseIPPrefix(test.route)
+		got, err := shrinkDefaultRoute(def)
+		if err != nil {
+			t.Fatalf("shrinkDefaultRoute(%q): %v", test.route, err)
+		}
+		for _, ip := range test.in {
+			if !got.Contains(netaddr.MustParseIP(ip)) {
+				t.Errorf("shrink(%q).Contains(%v) = false, want true", test.route, ip)
+			}
+		}
+		for _, ip := range test.out {
+			if got.Contains(netaddr.MustParseIP(ip)) {
+				t.Errorf("shrink(%q).Contains(%v) = true, want false", test.route, ip)
+			}
+		}
+		ips, _, err := interfaces.LocalAddresses()
+		if err != nil {
+			t.Fatal(err)
+		}
+		for _, ip := range ips {
+			want := test.localIPFn(ip)
+			if gotContains := got.Contains(ip); gotContains != want {
+				t.Errorf("shrink(%q).Contains(%v) = %v, want %v", test.route, ip, gotContains, want)
+			}
+		}
+	}
+}
+
+func TestPeerRoutes(t *testing.T) {
+	pp := netaddr.MustParseIPPrefix
+	tests := []struct {
+		name  string
+		peers []wgcfg.Peer
+		want  []netaddr.IPPrefix
+	}{
+		{
+			name: "small_v4",
+			peers: []wgcfg.Peer{
+				{
+					AllowedIPs: []netaddr.IPPrefix{
+						pp("100.101.102.103/32"),
+					},
+				},
+			},
+			want: []netaddr.IPPrefix{
+				pp("100.101.102.103/32"),
+			},
+		},
+		{
+			name: "big_v4",
+			peers: []wgcfg.Peer{
+				{
+					AllowedIPs: []netaddr.IPPrefix{
+						pp("100.101.102.103/32"),
+						pp("100.101.102.104/32"),
+						pp("100.101.102.105/32"),
+					},
+				},
+			},
+			want: []netaddr.IPPrefix{
+				pp("100.64.0.0/10"),
+			},
+		},
+		{
+			name: "has_1_v6",
+			peers: []wgcfg.Peer{
+				{
+					AllowedIPs: []netaddr.IPPrefix{
+						pp("fd7a:115c:a1e0:ab12:4843:cd96:6258:b240/128"),
+					},
+				},
+			},
+			want: []netaddr.IPPrefix{
+				pp("fd7a:115c:a1e0::/48"),
+			},
+		},
+		{
+			name: "has_2_v6",
+			peers: []wgcfg.Peer{
+				{
+					AllowedIPs: []netaddr.IPPrefix{
+						pp("fd7a:115c:a1e0:ab12:4843:cd96:6258:b240/128"),
+						pp("fd7a:115c:a1e0:ab12:4843:cd96:6258:b241/128"),
+					},
+				},
+			},
+			want: []netaddr.IPPrefix{
+				pp("fd7a:115c:a1e0::/48"),
+			},
+		},
+		{
+			name: "big_v4_big_v6",
+			peers: []wgcfg.Peer{
+				{
+					AllowedIPs: []netaddr.IPPrefix{
+						pp("100.101.102.103/32"),
+						pp("100.101.102.104/32"),
+						pp("100.101.102.105/32"),
+						pp("fd7a:115c:a1e0:ab12:4843:cd96:6258:b240/128"),
+						pp("fd7a:115c:a1e0:ab12:4843:cd96:6258:b241/128"),
+					},
+				},
+			},
+			want: []netaddr.IPPrefix{
+				pp("fd7a:115c:a1e0::/48"),
+				pp("100.64.0.0/10"),
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := peerRoutes(tt.peers, 2)
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("got = %v; want %v", got, tt.want)
+			}
+		})
+	}
+
+}

ipn/ipnlocal/loglines_test.go

@@ -2,18 +2,20 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package ipn
+package ipnlocal
 
 import (
 	"reflect"
 	"testing"
 	"time"
 
-	"tailscale.com/control/controlclient"
+	"tailscale.com/ipn"
+	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/logtail"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tstest"
 	"tailscale.com/types/key"
+	"tailscale.com/types/persist"
 	"tailscale.com/wgengine"
 )
 
@@ -23,9 +25,10 @@ import (
 func TestLocalLogLines(t *testing.T) {
 	logListen := tstest.NewLogLineTracker(t.Logf, []string{
 		"SetPrefs: %v",
-		"peer keys: %s",
-		"v%v peers: %v",
+		"[v1] peer keys: %s",
+		"[v1] v%v peers: %v",
 	})
+	defer logListen.Close()
 
 	logid := func(hex byte) logtail.PublicID {
 		var ret logtail.PublicID
@@ -37,9 +40,7 @@ func TestLocalLogLines(t *testing.T) {
 	idA := logid(0xaa)
 
 	// set up a LocalBackend, super bare bones. No functional data.
-	store := &MemoryStore{
-		cache: make(map[StateKey][]byte),
-	}
+	store := &ipn.MemoryStore{}
 	e, err := wgengine.NewFakeUserspaceEngine(logListen.Logf, 0)
 	if err != nil {
 		t.Fatal(err)
@@ -52,7 +53,7 @@ func TestLocalLogLines(t *testing.T) {
 	defer lb.Shutdown()
 
 	// custom adjustments for required non-nil fields
-	lb.prefs = NewPrefs()
+	lb.prefs = ipn.NewPrefs()
 	lb.hostinfo = &tailcfg.Hostinfo{}
 	// hacky manual override of the usual log-on-change behaviour of keylogf
 	lb.keyLogf = logListen.Logf
@@ -66,16 +67,16 @@ func TestLocalLogLines(t *testing.T) {
 	}
 
 	// log prefs line
-	persist := &controlclient.Persist{}
-	prefs := NewPrefs()
+	persist := &persist.Persist{}
+	prefs := ipn.NewPrefs()
 	prefs.Persist = persist
 	lb.SetPrefs(prefs)
 
-	t.Run("after_prefs", testWantRemain("peer keys: %s", "v%v peers: %v"))
+	t.Run("after_prefs", testWantRemain("[v1] peer keys: %s", "[v1] v%v peers: %v"))
 
 	// log peers, peer keys
 	status := &wgengine.Status{
-		Peers: []wgengine.PeerStatus{wgengine.PeerStatus{
+		Peers: []ipnstate.PeerStatusLite{{
 			TxBytes:       10,
 			RxBytes:       10,
 			LastHandshake: time.Now(),

ipn/ipnlocal/peerapi.go

@@ -0,0 +1,243 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ipnlocal
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"hash/crc32"
+	"html"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+
+	"inet.af/netaddr"
+	"tailscale.com/net/interfaces"
+	"tailscale.com/tailcfg"
+)
+
+var initListenConfig func(*net.ListenConfig, netaddr.IP, *interfaces.State, string) error
+
+type peerAPIServer struct {
+	b        *LocalBackend
+	rootDir  string
+	tunName  string
+	selfNode *tailcfg.Node
+}
+
+func (s *peerAPIServer) listen(ip netaddr.IP, ifState *interfaces.State) (ln net.Listener, err error) {
+	ipStr := ip.String()
+
+	var lc net.ListenConfig
+	if initListenConfig != nil {
+		// On iOS/macOS, this sets the lc.Control hook to
+		// setsockopt the interface index to bind to, to get
+		// out of the network sandbox.
+		if err := initListenConfig(&lc, ip, ifState, s.tunName); err != nil {
+			return nil, err
+		}
+		if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
+			ipStr = ""
+		}
+	}
+
+	tcp4or6 := "tcp4"
+	if ip.Is6() {
+		tcp4or6 = "tcp6"
+	}
+
+	// Make a best effort to pick a deterministic port number for
+	// the ip The lower three bytes are the same for IPv4 and IPv6
+	// Tailscale addresses (at least currently), so we'll usually
+	// get the same port number on both address families for
+	// dev/debugging purposes, which is nice. But it's not so
+	// deterministic that people will bake this into clients.
+	// We try a few times just in case something's already
+	// listening on that port (on all interfaces, probably).
+	for try := uint8(0); try < 5; try++ {
+		a16 := ip.As16()
+		hashData := a16[len(a16)-3:]
+		hashData[0] += try
+		tryPort := (32 << 10) | uint16(crc32.ChecksumIEEE(hashData))
+		ln, err = lc.Listen(context.Background(), tcp4or6, net.JoinHostPort(ipStr, strconv.Itoa(int(tryPort))))
+		if err == nil {
+			return ln, nil
+		}
+	}
+	// Fall back to random ephemeral port.
+	return lc.Listen(context.Background(), tcp4or6, net.JoinHostPort(ipStr, "0"))
+}
+
+type peerAPIListener struct {
+	ps     *peerAPIServer
+	ip     netaddr.IP
+	ln     net.Listener
+	lb     *LocalBackend
+	urlStr string
+}
+
+func (pln *peerAPIListener) Port() int {
+	ta, ok := pln.ln.Addr().(*net.TCPAddr)
+	if !ok {
+		return 0
+	}
+	return ta.Port
+}
+
+func (pln *peerAPIListener) serve() {
+	defer pln.ln.Close()
+	logf := pln.lb.logf
+	for {
+		c, err := pln.ln.Accept()
+		if errors.Is(err, net.ErrClosed) {
+			return
+		}
+		if err != nil {
+			logf("peerapi.Accept: %v", err)
+			return
+		}
+		ta, ok := c.RemoteAddr().(*net.TCPAddr)
+		if !ok {
+			c.Close()
+			logf("peerapi: unexpected RemoteAddr %#v", c.RemoteAddr())
+			continue
+		}
+		ipp, ok := netaddr.FromStdAddr(ta.IP, ta.Port, "")
+		if !ok {
+			logf("peerapi: bogus TCPAddr %#v", ta)
+			c.Close()
+			continue
+		}
+		peerNode, peerUser, ok := pln.lb.WhoIs(ipp)
+		if !ok {
+			logf("peerapi: unknown peer %v", ipp)
+			c.Close()
+			continue
+		}
+		h := &peerAPIHandler{
+			ps:         pln.ps,
+			isSelf:     pln.ps.selfNode.User == peerNode.User,
+			remoteAddr: ipp,
+			peerNode:   peerNode,
+			peerUser:   peerUser,
+			lb:         pln.lb,
+		}
+		httpServer := &http.Server{
+			Handler: h,
+		}
+		go httpServer.Serve(&oneConnListener{Listener: pln.ln, conn: c})
+	}
+}
+
+type oneConnListener struct {
+	net.Listener
+	conn net.Conn
+}
+
+func (l *oneConnListener) Accept() (c net.Conn, err error) {
+	c = l.conn
+	if c == nil {
+		err = io.EOF
+		return
+	}
+	err = nil
+	l.conn = nil
+	return
+}
+
+func (l *oneConnListener) Close() error { return nil }
+
+// peerAPIHandler serves the Peer API for a source specific client.
+type peerAPIHandler struct {
+	ps         *peerAPIServer
+	remoteAddr netaddr.IPPort
+	isSelf     bool                // whether peerNode is owned by same user as this node
+	peerNode   *tailcfg.Node       // peerNode is who's making the request
+	peerUser   tailcfg.UserProfile // profile of peerNode
+	lb         *LocalBackend
+}
+
+func (h *peerAPIHandler) logf(format string, a ...interface{}) {
+	h.ps.b.logf("peerapi: "+format, a...)
+}
+
+func (h *peerAPIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if strings.HasPrefix(r.URL.Path, "/v0/put/") {
+		h.put(w, r)
+		return
+	}
+	who := h.peerUser.DisplayName
+	fmt.Fprintf(w, `<html>
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<body>
+<h1>Hello, %s (%v)</h1>
+This is my Tailscale device. Your device is %v.
+`, html.EscapeString(who), h.remoteAddr.IP, html.EscapeString(h.peerNode.ComputedName))
+
+	if h.isSelf {
+		fmt.Fprintf(w, "<p>You are the owner of this node.\n")
+	}
+}
+
+func (h *peerAPIHandler) put(w http.ResponseWriter, r *http.Request) {
+	if !h.isSelf {
+		http.Error(w, "not owner", http.StatusForbidden)
+		return
+	}
+	if r.Method != "PUT" {
+		http.Error(w, "not method PUT", http.StatusMethodNotAllowed)
+		return
+	}
+	if h.ps.rootDir == "" {
+		http.Error(w, "no rootdir", http.StatusInternalServerError)
+		return
+	}
+	name := path.Base(r.URL.Path)
+	if name == "." || name == "/" {
+		http.Error(w, "bad filename", http.StatusForbidden)
+		return
+	}
+	fileBase := strings.ReplaceAll(url.PathEscape(name), ":", "%3a")
+	dstFile := filepath.Join(h.ps.rootDir, fileBase)
+	f, err := os.Create(dstFile)
+	if err != nil {
+		h.logf("put Create error: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	var success bool
+	defer func() {
+		if !success {
+			os.Remove(dstFile)
+		}
+	}()
+	n, err := io.Copy(f, r.Body)
+	if err != nil {
+		f.Close()
+		h.logf("put Copy error: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if err := f.Close(); err != nil {
+		h.logf("put Close error: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	h.logf("put(%q): %d bytes from %v/%v", name, n, h.remoteAddr.IP, h.peerNode.ComputedName)
+
+	// TODO: set modtime
+	// TODO: some real response
+	success = true
+	io.WriteString(w, "{}\n")
+}

ipn/ipnlocal/peerapi_macios_ext.go

@@ -0,0 +1,54 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin,redo ios,redo
+
+package ipnlocal
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"strings"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+	"inet.af/netaddr"
+	"tailscale.com/net/interfaces"
+)
+
+func init() {
+	initListenConfig = initListenConfigNetworkExtension
+}
+
+// initListenConfigNetworkExtension configures nc for listening on IP
+// through the iOS/macOS Network/System Extension (Packet Tunnel
+// Provider) sandbox.
+func initListenConfigNetworkExtension(nc *net.ListenConfig, ip netaddr.IP, st *interfaces.State, tunIfName string) error {
+	tunIf, ok := st.Interface[tunIfName]
+	if !ok {
+		return fmt.Errorf("no interface with name %q", tunIfName)
+	}
+	nc.Control = func(network, address string, c syscall.RawConn) error {
+		var sockErr error
+		err := c.Control(func(fd uintptr) {
+
+			v6 := strings.Contains(address, "]:") || strings.HasSuffix(network, "6") // hacky test for v6
+			proto := unix.IPPROTO_IP
+			opt := unix.IP_BOUND_IF
+			if v6 {
+				proto = unix.IPPROTO_IPV6
+				opt = unix.IPV6_BOUND_IF
+			}
+
+			sockErr = unix.SetsockoptInt(int(fd), proto, opt, tunIf.Index)
+			log.Printf("peerapi: bind(%q, %q) on index %v = %v", network, address, tunIf.Index, sockErr)
+		})
+		if err != nil {
+			return err
+		}
+		return sockErr
+	}
+	return nil
+}

ipn/ipnserver/server.go

@@ -19,14 +19,20 @@ import (
 	"os/signal"
 	"os/user"
 	"runtime"
+	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"time"
 
+	"go4.org/mem"
 	"inet.af/netaddr"
+	"inet.af/peercred"
 	"tailscale.com/control/controlclient"
 	"tailscale.com/ipn"
+	"tailscale.com/ipn/ipnlocal"
+	"tailscale.com/ipn/localapi"
 	"tailscale.com/log/filelogger"
 	"tailscale.com/logtail/backoff"
 	"tailscale.com/net/netstat"
@@ -34,6 +40,7 @@ import (
 	"tailscale.com/smallzstd"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/pidowner"
+	"tailscale.com/util/systemd"
 	"tailscale.com/version"
 	"tailscale.com/wgengine"
 )
@@ -90,7 +97,7 @@ type Options struct {
 // server is an IPN backend and its set of 0 or more active connections
 // talking to an IPN backend.
 type server struct {
-	b    *ipn.LocalBackend
+	b    *ipnlocal.LocalBackend
 	logf logger.Logf
 	// resetOnZero is whether to call bs.Reset on transition from
 	// 1->0 connections.  That is, this is whether the backend is
@@ -110,21 +117,34 @@ type server struct {
 	disconnectSub  map[chan<- struct{}]struct{} // keys are subscribers of disconnects
 }
 
-// connIdentity represents the owner of a localhost TCP connection.
+// connIdentity represents the owner of a localhost TCP or unix socket connection.
 type connIdentity struct {
-	Unknown bool
-	Pid     int
-	UserID  string
-	User    *user.User
+	Conn       net.Conn
+	NotWindows bool // runtime.GOOS != "windows"
+
+	// Fields used when NotWindows:
+	IsUnixSock bool            // Conn is a *net.UnixConn
+	Creds      *peercred.Creds // or nil
+
+	// Used on Windows:
+	// TODO(bradfitz): merge these into the peercreds package and
+	// use that for all.
+	Pid    int
+	UserID string
+	User   *user.User
 }
 
 // getConnIdentity returns the localhost TCP connection's identity information
 // (pid, userid, user). If it's not Windows (for now), it returns a nil error
-// and a ConnIdentity with Unknown set true. It's only an error if we expected
+// and a ConnIdentity with NotWindows set true. It's only an error if we expected
 // to be able to map it and couldn't.
 func (s *server) getConnIdentity(c net.Conn) (ci connIdentity, err error) {
+	ci = connIdentity{Conn: c}
 	if runtime.GOOS != "windows" { // for now; TODO: expand to other OSes
-		return connIdentity{Unknown: true}, nil
+		ci.NotWindows = true
+		_, ci.IsUnixSock = c.(*net.UnixConn)
+		ci.Creds, _ = peercred.Get(c)
+		return ci, nil
 	}
 	la, err := netaddr.ParseIPPort(c.LocalAddr().String())
 	if err != nil {
@@ -215,13 +235,22 @@ func (s *server) blockWhileInUse(conn io.Reader, ci connIdentity) {
 	}
 }
 
+// bufferHasHTTPRequest reports whether br looks like it has an HTTP
+// request in it, without reading any bytes from it.
+func bufferHasHTTPRequest(br *bufio.Reader) bool {
+	peek, _ := br.Peek(br.Buffered())
+	return mem.HasPrefix(mem.B(peek), mem.S("GET ")) ||
+		mem.HasPrefix(mem.B(peek), mem.S("POST ")) ||
+		mem.Contains(mem.B(peek), mem.S(" HTTP/"))
+}
+
 func (s *server) serveConn(ctx context.Context, c net.Conn, logf logger.Logf) {
 	// First see if it's an HTTP request.
 	br := bufio.NewReader(c)
 	c.SetReadDeadline(time.Now().Add(time.Second))
-	peek, _ := br.Peek(4)
+	br.Peek(4)
 	c.SetReadDeadline(time.Time{})
-	isHTTPReq := string(peek) == "GET "
+	isHTTPReq := bufferHasHTTPRequest(br)
 
 	ci, err := s.addConn(c, isHTTPReq)
 	if err != nil {
@@ -248,7 +277,7 @@ func (s *server) serveConn(ctx context.Context, c net.Conn, logf logger.Logf) {
 	s.b.SetCurrentUserID(ci.UserID)
 
 	if isHTTPReq {
-		httpServer := http.Server{
+		httpServer := &http.Server{
 			// Localhost connections are cheap; so only do
 			// keep-alives for a short period of time, as these
 			// active connections lock the server into only serving
@@ -265,18 +294,24 @@ func (s *server) serveConn(ctx context.Context, c net.Conn, logf logger.Logf) {
 	}
 
 	defer s.removeAndCloseConn(c)
-	logf("incoming control connection")
+	logf("[v1] incoming control connection")
+
+	if isReadonlyConn(ci, logf) {
+		ctx = ipn.ReadonlyContextOf(ctx)
+	}
 
 	for ctx.Err() == nil {
 		msg, err := ipn.ReadMsg(br)
 		if err != nil {
-			if ctx.Err() == nil {
+			if errors.Is(err, io.EOF) {
+				logf("[v1] ReadMsg: %v", err)
+			} else if ctx.Err() == nil {
 				logf("ReadMsg: %v", err)
 			}
 			return
 		}
 		s.bsMu.Lock()
-		if err := s.bs.GotCommandMsg(msg); err != nil {
+		if err := s.bs.GotCommandMsg(ctx, msg); err != nil {
 			logf("GotCommandMsg: %v", err)
 		}
 		gotQuit := s.bs.GotQuit
@@ -287,6 +322,82 @@ func (s *server) serveConn(ctx context.Context, c net.Conn, logf logger.Logf) {
 	}
 }
 
+func isReadonlyConn(ci connIdentity, logf logger.Logf) bool {
+	if runtime.GOOS == "windows" {
+		// Windows doesn't need/use this mechanism, at least yet. It
+		// has a different last-user-wins auth model.
+		return false
+	}
+	const ro = true
+	const rw = false
+	if !safesocket.PlatformUsesPeerCreds() {
+		return rw
+	}
+	creds := ci.Creds
+	if creds == nil {
+		logf("connection from unknown peer; read-only")
+		return ro
+	}
+	uid, ok := creds.UserID()
+	if !ok {
+		logf("connection from peer with unknown userid; read-only")
+		return ro
+	}
+	if uid == "0" {
+		logf("connection from userid %v; root has access", uid)
+		return rw
+	}
+	if selfUID := os.Getuid(); selfUID != 0 && uid == strconv.Itoa(selfUID) {
+		logf("connection from userid %v; connection from non-root user matching daemon has access", uid)
+		return rw
+	}
+	var adminGroupID string
+	switch runtime.GOOS {
+	case "darwin":
+		adminGroupID = darwinAdminGroupID()
+	default:
+		logf("connection from userid %v; read-only", uid)
+		return ro
+	}
+	if adminGroupID == "" {
+		logf("connection from userid %v; no system admin group found, read-only", uid)
+		return ro
+	}
+	u, err := user.LookupId(uid)
+	if err != nil {
+		logf("connection from userid %v; failed to look up user; read-only", uid)
+		return ro
+	}
+	gids, err := u.GroupIds()
+	if err != nil {
+		logf("connection from userid %v; failed to look up groups; read-only", uid)
+		return ro
+	}
+	for _, gid := range gids {
+		if gid == adminGroupID {
+			logf("connection from userid %v; is local admin, has access", uid)
+			return rw
+		}
+	}
+	logf("connection from userid %v; read-only", uid)
+	return ro
+}
+
+var darwinAdminGroupIDCache atomic.Value // of string
+
+func darwinAdminGroupID() string {
+	s, _ := darwinAdminGroupIDCache.Load().(string)
+	if s != "" {
+		return s
+	}
+	g, err := user.LookupGroup("admin")
+	if err != nil {
+		return ""
+	}
+	darwinAdminGroupIDCache.Store(g.Gid)
+	return g.Gid
+}
+
 // inUseOtherUserError is the error type for when the server is in use
 // by a different local user.
 type inUseOtherUserError struct{ error }
@@ -319,6 +430,25 @@ func (s *server) checkConnIdentityLocked(ci connIdentity) error {
 	return nil
 }
 
+// localAPIPermissions returns the permissions for the given identity accessing
+// the Tailscale local daemon API.
+//
+// s.mu must not be held.
+func (s *server) localAPIPermissions(ci connIdentity) (read, write bool) {
+	if runtime.GOOS == "windows" {
+		s.mu.Lock()
+		defer s.mu.Unlock()
+		if s.checkConnIdentityLocked(ci) == nil {
+			return true, true
+		}
+		return false, false
+	}
+	if ci.IsUnixSock {
+		return true, !isReadonlyConn(ci, logger.Discard)
+	}
+	return false, false
+}
+
 // registerDisconnectSub adds ch as a subscribe to connection disconnect
 // events. If add is false, the subscriber is removed.
 func (s *server) registerDisconnectSub(ch chan<- struct{}, add bool) {
@@ -352,7 +482,7 @@ func (s *server) addConn(c net.Conn, isHTTP bool) (ci connIdentity, err error) {
 		if doReset {
 			s.logf("identity changed; resetting server")
 			s.bsMu.Lock()
-			s.bs.Reset()
+			s.bs.Reset(context.TODO())
 			s.bsMu.Unlock()
 		}
 	}()
@@ -404,7 +534,7 @@ func (s *server) removeAndCloseConn(c net.Conn) {
 		} else {
 			s.logf("client disconnected; stopping server")
 			s.bsMu.Lock()
-			s.bs.Reset()
+			s.bs.Reset(context.TODO())
 			s.bsMu.Unlock()
 		}
 	}
@@ -435,7 +565,7 @@ func (s *server) setServerModeUserLocked() {
 		s.logf("ipnserver: [unexpected] now in server mode, but no connected client")
 		return
 	}
-	if ci.Unknown {
+	if ci.NotWindows {
 		return
 	}
 	if ci.User != nil {
@@ -496,41 +626,6 @@ func Run(ctx context.Context, logf logger.Logf, logid string, getEngine func() (
 	}()
 	logf("Listening on %v", listen.Addr())
 
-	bo := backoff.NewBackoff("ipnserver", logf, 30*time.Second)
-	var unservedConn net.Conn // if non-nil, accepted, but hasn't served yet
-
-	eng, err := getEngine()
-	if err != nil {
-		logf("ipnserver: initial getEngine call: %v", err)
-		for i := 1; ctx.Err() == nil; i++ {
-			c, err := listen.Accept()
-			if err != nil {
-				logf("%d: Accept: %v", i, err)
-				bo.BackOff(ctx, err)
-				continue
-			}
-			logf("ipnserver: try%d: trying getEngine again...", i)
-			eng, err = getEngine()
-			if err == nil {
-				logf("%d: GetEngine worked; exiting failure loop", i)
-				unservedConn = c
-				break
-			}
-			logf("ipnserver%d: getEngine failed again: %v", i, err)
-			errMsg := err.Error()
-			go func() {
-				defer c.Close()
-				serverToClient := func(b []byte) { ipn.WriteMsg(c, b) }
-				bs := ipn.NewBackendServer(logf, nil, serverToClient)
-				bs.SendErrorMessage(errMsg)
-				time.Sleep(time.Second)
-			}()
-		}
-		if err := ctx.Err(); err != nil {
-			return err
-		}
-	}
-
 	var store ipn.StateStore
 	if opts.StatePath != "" {
 		store, err = ipn.NewFileStore(opts.StatePath)
@@ -559,7 +654,83 @@ func Run(ctx context.Context, logf logger.Logf, logid string, getEngine func() (
 		store = &ipn.MemoryStore{}
 	}
 
-	b, err := ipn.NewLocalBackend(logf, logid, store, eng)
+	bo := backoff.NewBackoff("ipnserver", logf, 30*time.Second)
+	var unservedConn net.Conn // if non-nil, accepted, but hasn't served yet
+
+	eng, err := getEngine()
+	if err != nil {
+		logf("ipnserver: initial getEngine call: %v", err)
+
+		// Issue 1187: on Windows, in unattended mode,
+		// sometimes we try 5 times and fail to create the
+		// engine before the system's ready. Hack until the
+		// bug if fixed properly: if we're running in
+		// unattended mode on Windows, keep trying forever,
+		// waiting for the machine to be ready (networking to
+		// come up?) and then dial our own safesocket TCP
+		// listener to wake up the usual mechanism that lets
+		// us surface getEngine errors to UI clients. (We
+		// don't want to just call getEngine in a loop without
+		// the listener.Accept, as we do want to handle client
+		// connections so we can tell them about errors)
+
+		bootRaceWaitForEngine, bootRaceWaitForEngineCancel := context.WithTimeout(context.Background(), time.Minute)
+		if runtime.GOOS == "windows" && opts.AutostartStateKey != "" {
+			logf("ipnserver: in unattended mode, waiting for engine availability")
+			getEngine = getEngineUntilItWorksWrapper(getEngine)
+			// Wait for it to be ready.
+			go func() {
+				defer bootRaceWaitForEngineCancel()
+				t0 := time.Now()
+				for {
+					time.Sleep(10 * time.Second)
+					if _, err := getEngine(); err != nil {
+						logf("ipnserver: unattended mode engine load: %v", err)
+						continue
+					}
+					c, err := net.Dial("tcp", listen.Addr().String())
+					logf("ipnserver: engine created after %v; waking up Accept: Dial error: %v", time.Since(t0).Round(time.Second), err)
+					if err == nil {
+						c.Close()
+					}
+					break
+				}
+			}()
+		} else {
+			bootRaceWaitForEngineCancel()
+		}
+
+		for i := 1; ctx.Err() == nil; i++ {
+			c, err := listen.Accept()
+			if err != nil {
+				logf("%d: Accept: %v", i, err)
+				bo.BackOff(ctx, err)
+				continue
+			}
+			<-bootRaceWaitForEngine.Done()
+			logf("ipnserver: try%d: trying getEngine again...", i)
+			eng, err = getEngine()
+			if err == nil {
+				logf("%d: GetEngine worked; exiting failure loop", i)
+				unservedConn = c
+				break
+			}
+			logf("ipnserver%d: getEngine failed again: %v", i, err)
+			errMsg := err.Error()
+			go func() {
+				defer c.Close()
+				serverToClient := func(b []byte) { ipn.WriteMsg(c, b) }
+				bs := ipn.NewBackendServer(logf, nil, serverToClient)
+				bs.SendErrorMessage(errMsg)
+				time.Sleep(time.Second)
+			}()
+		}
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+	}
+
+	b, err := ipnlocal.NewLocalBackend(logf, logid, store, eng)
 	if err != nil {
 		return fmt.Errorf("NewLocalBackend: %v", err)
 	}
@@ -578,7 +749,7 @@ func Run(ctx context.Context, logf logger.Logf, logid string, getEngine func() (
 	server.bs = ipn.NewBackendServer(logf, b, server.writeToClients)
 
 	if opts.AutostartStateKey != "" {
-		server.bs.GotCommand(&ipn.Command{
+		server.bs.GotCommand(context.TODO(), &ipn.Command{
 			Version: version.Long,
 			Start: &ipn.StartArgs{
 				Opts: ipn.Options{
@@ -589,6 +760,7 @@ func Run(ctx context.Context, logf logger.Logf, logid string, getEngine func() (
 		})
 	}
 
+	systemd.Ready()
 	for i := 1; ctx.Err() == nil; i++ {
 		var c net.Conn
 		var err error
@@ -724,6 +896,10 @@ func BabysitProc(ctx context.Context, args []string, logf logger.Logf) {
 		// pipe. We'll make a new one when we restart the subproc.
 		wStdin.Close()
 
+		if os.Getenv("TS_DEBUG_RESTART_CRASHED") == "0" {
+			log.Fatalf("Process ended.")
+		}
+
 		if time.Since(startTime) < 60*time.Second {
 			bo.BackOff(ctx, fmt.Errorf("subproc early exit: %v", err))
 		} else {
@@ -744,6 +920,27 @@ func FixedEngine(eng wgengine.Engine) func() (wgengine.Engine, error) {
 	return func() (wgengine.Engine, error) { return eng, nil }
 }
 
+// getEngineUntilItWorksWrapper returns a getEngine wrapper that does
+// not call getEngine concurrently and stops calling getEngine once
+// it's returned a working engine.
+func getEngineUntilItWorksWrapper(getEngine func() (wgengine.Engine, error)) func() (wgengine.Engine, error) {
+	var mu sync.Mutex
+	var engGood wgengine.Engine
+	return func() (wgengine.Engine, error) {
+		mu.Lock()
+		defer mu.Unlock()
+		if engGood != nil {
+			return engGood, nil
+		}
+		e, err := getEngine()
+		if err != nil {
+			return nil, err
+		}
+		engGood = e
+		return e, nil
+	}
+}
+
 type dummyAddr string
 type oneConnListener struct {
 	conn net.Conn
@@ -785,8 +982,15 @@ func (psc *protoSwitchConn) Close() error {
 }
 
 func (s *server) localhostHandler(ci connIdentity) http.Handler {
+	lah := localapi.NewHandler(s.b)
+	lah.PermitRead, lah.PermitWrite = s.localAPIPermissions(ci)
+
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if ci.Unknown {
+		if strings.HasPrefix(r.URL.Path, "/localapi/") {
+			lah.ServeHTTP(w, r)
+			return
+		}
+		if ci.NotWindows {
 			io.WriteString(w, "<html><title>Tailscale</title><body><h1>Tailscale</h1>This is the local Tailscale daemon.")
 			return
 		}
@@ -794,7 +998,7 @@ func (s *server) localhostHandler(ci connIdentity) http.Handler {
 	})
 }
 
-func serveHTMLStatus(w http.ResponseWriter, b *ipn.LocalBackend) {
+func serveHTMLStatus(w http.ResponseWriter, b *ipnlocal.LocalBackend) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	st := b.Status()
 	// TODO(bradfitz): add LogID and opts to st?

ipn/ipnstate/ipnstate.go

@@ -21,14 +21,30 @@ import (
 	"inet.af/netaddr"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
+	"tailscale.com/util/dnsname"
 )
 
 // Status represents the entire state of the IPN network.
 type Status struct {
+	// Version is the daemon's long version (see version.Long).
+	Version string
+
+	// BackendState is an ipn.State string value:
+	//  "NoState", "NeedsLogin", "NeedsMachineAuth", "Stopped",
+	//  "Starting", "Running".
 	BackendState string
+
+	AuthURL      string       // current URL provided by control to authorize client
 	TailscaleIPs []netaddr.IP // Tailscale IP(s) assigned to this node
 	Self         *PeerStatus
 
+	// MagicDNSSuffix is the network's MagicDNS suffix for nodes
+	// in the network such as "userfoo.tailscale.net".
+	// There are no surrounding dots.
+	// MagicDNSSuffix should be populated regardless of whether a domain
+	// has MagicDNS enabled.
+	MagicDNSSuffix string
+
 	Peer map[key.Public]*PeerStatus
 	User map[tailcfg.UserID]tailcfg.UserProfile
 }
@@ -42,6 +58,12 @@ func (s *Status) Peers() []key.Public {
 	return kk
 }
 
+type PeerStatusLite struct {
+	TxBytes, RxBytes int64
+	LastHandshake    time.Time
+	NodeKey          tailcfg.NodeKey
+}
+
 type PeerStatus struct {
 	PublicKey key.Public
 	HostName  string // HostInfo's Hostname (not a DNS name or necessarily unique)
@@ -63,6 +85,15 @@ type PeerStatus struct {
 	LastSeen      time.Time // last seen to tailcontrol
 	LastHandshake time.Time // with local wireguard
 	KeepAlive     bool
+	ExitNode      bool // true if this is the currently selected exit node.
+
+	PeerAPIURL []string
+
+	// ShareeNode indicates this node exists in the netmap because
+	// it's owned by a shared-to user and that node might connect
+	// to us. These nodes should be hidden by "tailscale status"
+	// etc by default.
+	ShareeNode bool `json:",omitempty"`
 
 	// InNetworkMap means that this peer was seen in our latest network map.
 	// In theory, all of InNetworkMap and InMagicSock and InEngine should all be true.
@@ -77,24 +108,22 @@ type PeerStatus struct {
 	InEngine bool
 }
 
-// SimpleHostName returns a potentially simplified version of ps.HostName for display purposes.
-func (ps *PeerStatus) SimpleHostName() string {
-	n := ps.HostName
-	n = strings.TrimSuffix(n, ".local")
-	n = strings.TrimSuffix(n, ".localdomain")
-	return n
-}
-
 type StatusBuilder struct {
 	mu     sync.Mutex
 	locked bool
 	st     Status
 }
 
-func (sb *StatusBuilder) SetBackendState(v string) {
+// MutateStatus calls f with the status to mutate.
+//
+// It may not assume other fields of status are already populated, and
+// may not retain or write to the Status after f returns.
+//
+// MutateStatus acquires a lock so f must not call back into sb.
+func (sb *StatusBuilder) MutateStatus(f func(*Status)) {
 	sb.mu.Lock()
 	defer sb.mu.Unlock()
-	sb.st.BackendState = v
+	f(&sb.st)
 }
 
 func (sb *StatusBuilder) Status() *Status {
@@ -104,11 +133,19 @@ func (sb *StatusBuilder) Status() *Status {
 	return &sb.st
 }
 
-// SetSelfStatus sets the status of the local machine.
-func (sb *StatusBuilder) SetSelfStatus(ss *PeerStatus) {
+// MutateSelfStatus calls f with the PeerStatus of our own node to mutate.
+//
+// It may not assume other fields of status are already populated, and
+// may not retain or write to the Status after f returns.
+//
+// MutateStatus acquires a lock so f must not call back into sb.
+func (sb *StatusBuilder) MutateSelfStatus(f func(*PeerStatus)) {
 	sb.mu.Lock()
 	defer sb.mu.Unlock()
-	sb.st.Self = ss
+	if sb.st.Self == nil {
+		sb.st.Self = new(PeerStatus)
+	}
+	f(sb.st.Self)
 }
 
 // AddUser adds a user profile to the status.
@@ -218,6 +255,12 @@ func (sb *StatusBuilder) AddPeer(peer key.Public, st *PeerStatus) {
 	if st.KeepAlive {
 		e.KeepAlive = true
 	}
+	if st.ExitNode {
+		e.ExitNode = true
+	}
+	if st.ShareeNode {
+		e.ShareeNode = true
+	}
 }
 
 type StatusUpdater interface {
@@ -258,13 +301,22 @@ table tbody tr:nth-child(even) td { background-color: #f5f5f5; }
 	f("<p>Tailscale IP: %s", strings.Join(ips, ", "))
 
 	f("<table>\n<thead>\n")
-	f("<tr><th>Peer</th><th>Node</th><th>Owner</th><th>Rx</th><th>Tx</th><th>Activity</th><th>Endpoints</th></tr>\n")
+	f("<tr><th>Peer</th><th>OS</th><th>Node</th><th>Owner</th><th>Rx</th><th>Tx</th><th>Activity</th><th>Connection</th></tr>\n")
 	f("</thead>\n<tbody>\n")
 
 	now := time.Now()
 
+	var peers []*PeerStatus
 	for _, peer := range st.Peers() {
 		ps := st.Peer[peer]
+		if ps.ShareeNode {
+			continue
+		}
+		peers = append(peers, ps)
+	}
+	SortPeers(peers)
+
+	for _, ps := range peers {
 		var actAgo string
 		if !ps.LastWrite.IsZero() {
 			ago := now.Sub(ps.LastWrite)
@@ -280,40 +332,41 @@ table tbody tr:nth-child(even) td { background-color: #f5f5f5; }
 				owner = owner[:i]
 			}
 		}
-		f("<tr><td>%s</td><td>%s %s<br><span class=\"tailaddr\">%s</span></td><td class=\"acenter owner\">%s</td><td class=\"aright\">%v</td><td class=\"aright\">%v</td><td class=\"aright\">%v</td>",
-			peer.ShortString(),
-			html.EscapeString(ps.SimpleHostName()),
+
+		hostName := dnsname.SanitizeHostname(ps.HostName)
+		dnsName := dnsname.TrimSuffix(ps.DNSName, st.MagicDNSSuffix)
+		if strings.EqualFold(dnsName, hostName) || ps.UserID != st.Self.UserID {
+			hostName = ""
+		}
+		var hostNameHTML string
+		if hostName != "" {
+			hostNameHTML = "<br>" + html.EscapeString(hostName)
+		}
+
+		f("<tr><td>%s</td><td class=acenter>%s</td>"+
+			"<td><b>%s</b>%s<div class=\"tailaddr\">%s</div></td><td class=\"acenter owner\">%s</td><td class=\"aright\">%v</td><td class=\"aright\">%v</td><td class=\"aright\">%v</td>",
+			ps.PublicKey.ShortString(),
 			osEmoji(ps.OS),
+			html.EscapeString(dnsName),
+			hostNameHTML,
 			ps.TailAddr,
 			html.EscapeString(owner),
 			ps.RxBytes,
 			ps.TxBytes,
 			actAgo,
 		)
-		f("<td class=\"aright\">")
+		f("<td>")
+
 		// TODO: let server report this active bool instead
 		active := !ps.LastWrite.IsZero() && time.Since(ps.LastWrite) < 2*time.Minute
-		relay := ps.Relay
-		if relay != "" {
-			if active && ps.CurAddr == "" {
-				f("🔗 <b>derp-%v</b><br>", html.EscapeString(relay))
-			} else {
-				f("derp-%v<br>", html.EscapeString(relay))
+		if active {
+			if ps.Relay != "" && ps.CurAddr == "" {
+				f("relay <b>%s</b>", html.EscapeString(ps.Relay))
+			} else if ps.CurAddr != "" {
+				f("direct <b>%s</b>", html.EscapeString(ps.CurAddr))
 			}
 		}
 
-		match := false
-		for _, addr := range ps.Addrs {
-			if addr == ps.CurAddr {
-				match = true
-				f("🔗 <b>%s</b><br>", addr)
-			} else {
-				f("%s<br>", addr)
-			}
-		}
-		if ps.CurAddr != "" && !match {
-			f("<b>%s</b> \xf0\x9f\xa7\xb3<br>", ps.CurAddr)
-		}
 		f("</td>") // end Addrs
 
 		f("</tr>\n")
@@ -352,10 +405,37 @@ type PingResult struct {
 	Err            string
 	LatencySeconds float64
 
-	Endpoint string // ip:port if direct UDP was used
+	// Endpoint is the ip:port if direct UDP was used.
+	// It is not currently set for TSMP pings.
+	Endpoint string
 
-	DERPRegionID   int    // non-zero if DERP was used
-	DERPRegionCode string // three-letter airport/region code if DERP was used
+	// DERPRegionID is non-zero DERP region ID if DERP was used.
+	// It is not currently set for TSMP pings.
+	DERPRegionID int
+
+	// DERPRegionCode is the three-letter region code
+	// corresponding to DERPRegionID.
+	// It is not currently set for TSMP pings.
+	DERPRegionCode string
+
+	// PeerAPIPort is set by TSMP ping responses for peers that
+	// are running a peerapi server. This is the port they're
+	// running the server on.
+	PeerAPIPort uint16 `json:",omitempty"`
 
 	// TODO(bradfitz): details like whether port mapping was used on either side? (Once supported)
 }
+
+func SortPeers(peers []*PeerStatus) {
+	sort.Slice(peers, func(i, j int) bool { return sortKey(peers[i]) < sortKey(peers[j]) })
+}
+
+func sortKey(ps *PeerStatus) string {
+	if ps.DNSName != "" {
+		return ps.DNSName
+	}
+	if ps.HostName != "" {
+		return ps.HostName
+	}
+	return ps.TailAddr
+}

ipn/localapi/localapi.go

@@ -0,0 +1,143 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package localapi contains the HTTP server handlers for tailscaled's API server.
+package localapi
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"runtime"
+	"strconv"
+
+	"inet.af/netaddr"
+	"tailscale.com/ipn/ipnlocal"
+	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/tailcfg"
+)
+
+func NewHandler(b *ipnlocal.LocalBackend) *Handler {
+	return &Handler{b: b}
+}
+
+type Handler struct {
+	// RequiredPassword, if non-empty, forces all HTTP
+	// requests to have HTTP basic auth with this password.
+	// It's used by the sandboxed macOS sameuserproof GUI auth mechanism.
+	RequiredPassword string
+
+	// PermitRead is whether read-only HTTP handlers are allowed.
+	PermitRead bool
+
+	// PermitWrite is whether mutating HTTP handlers are allowed.
+	PermitWrite bool
+
+	b *ipnlocal.LocalBackend
+}
+
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if h.b == nil {
+		http.Error(w, "server has no local backend", http.StatusInternalServerError)
+		return
+	}
+	if h.RequiredPassword != "" {
+		_, pass, ok := r.BasicAuth()
+		if !ok {
+			http.Error(w, "auth required", http.StatusUnauthorized)
+			return
+		}
+		if pass != h.RequiredPassword {
+			http.Error(w, "bad password", http.StatusForbidden)
+			return
+		}
+	}
+	switch r.URL.Path {
+	case "/localapi/v0/whois":
+		h.serveWhoIs(w, r)
+	case "/localapi/v0/goroutines":
+		h.serveGoroutines(w, r)
+	case "/localapi/v0/status":
+		h.serveStatus(w, r)
+	default:
+		io.WriteString(w, "tailscaled\n")
+	}
+}
+
+func (h *Handler) serveWhoIs(w http.ResponseWriter, r *http.Request) {
+	if !h.PermitRead {
+		http.Error(w, "whois access denied", http.StatusForbidden)
+		return
+	}
+	b := h.b
+	var ipp netaddr.IPPort
+	if v := r.FormValue("addr"); v != "" {
+		var err error
+		ipp, err = netaddr.ParseIPPort(v)
+		if err != nil {
+			http.Error(w, "invalid 'addr' parameter", 400)
+			return
+		}
+	} else {
+		http.Error(w, "missing 'addr' parameter", 400)
+		return
+	}
+	n, u, ok := b.WhoIs(ipp)
+	if !ok {
+		http.Error(w, "no match for IP:port", 404)
+		return
+	}
+	res := &tailcfg.WhoIsResponse{
+		Node:        n,
+		UserProfile: &u,
+	}
+	j, err := json.MarshalIndent(res, "", "\t")
+	if err != nil {
+		http.Error(w, "JSON encoding error", 500)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(j)
+}
+
+func (h *Handler) serveGoroutines(w http.ResponseWriter, r *http.Request) {
+	// Require write access out of paranoia that the goroutine dump
+	// (at least its arguments) might contain something sensitive.
+	if !h.PermitWrite {
+		http.Error(w, "goroutine dump access denied", http.StatusForbidden)
+		return
+	}
+	buf := make([]byte, 2<<20)
+	buf = buf[:runtime.Stack(buf, true)]
+	w.Header().Set("Content-Type", "text/plain")
+	w.Write(buf)
+}
+
+func (h *Handler) serveStatus(w http.ResponseWriter, r *http.Request) {
+	if !h.PermitRead {
+		http.Error(w, "status access denied", http.StatusForbidden)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	var st *ipnstate.Status
+	if defBool(r.FormValue("peers"), true) {
+		st = h.b.Status()
+	} else {
+		st = h.b.StatusWithoutPeers()
+	}
+	e := json.NewEncoder(w)
+	e.SetIndent("", "\t")
+	e.Encode(st)
+}
+
+func defBool(a string, def bool) bool {
+	if a == "" {
+		return def
+	}
+	v, err := strconv.ParseBool(a)
+	if err != nil {
+		return def
+	}
+	return v
+}

ipn/message.go

@@ -5,6 +5,8 @@
 package ipn
 
 import (
+	"bytes"
+	"context"
 	"encoding/binary"
 	"encoding/json"
 	"errors"
@@ -13,12 +15,32 @@ import (
 	"log"
 	"time"
 
-	"golang.org/x/oauth2"
+	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/structs"
 	"tailscale.com/version"
 )
 
+type readOnlyContextKey struct{}
+
+// IsReadonlyContext reports whether ctx is a read-only context, as currently used
+// by Unix non-root users running the "tailscale" CLI command. They can run "status",
+// but not much else.
+func IsReadonlyContext(ctx context.Context) bool {
+	return ctx.Value(readOnlyContextKey{}) != nil
+}
+
+// ReadonlyContextOf returns ctx wrapped with a context value that
+// will make IsReadonlyContext reports true.
+func ReadonlyContextOf(ctx context.Context) context.Context {
+	if IsReadonlyContext(ctx) {
+		return ctx
+	}
+	return context.WithValue(ctx, readOnlyContextKey{}, readOnlyContextKey{})
+}
+
+var jsonEscapedZero = []byte(`\u0000`)
+
 type NoArgs struct{}
 
 type StartArgs struct {
@@ -34,7 +56,8 @@ type FakeExpireAfterArgs struct {
 }
 
 type PingArgs struct {
-	IP string
+	IP      string
+	UseTSMP bool
 }
 
 // Command is a command message that is JSON encoded and sent by a
@@ -54,7 +77,7 @@ type Command struct {
 	Quit                  *NoArgs
 	Start                 *StartArgs
 	StartLoginInteractive *NoArgs
-	Login                 *oauth2.Token
+	Login                 *tailcfg.Oauth2Token
 	Logout                *NoArgs
 	SetPrefs              *SetPrefsArgs
 	SetWantRunning        *bool
@@ -85,6 +108,9 @@ func (bs *BackendServer) send(n Notify) {
 	if err != nil {
 		log.Fatalf("Failed json.Marshal(notify): %v\n%#v", err, n)
 	}
+	if bytes.Contains(b, jsonEscapedZero) {
+		log.Printf("[unexpected] zero byte in BackendServer.send notify message: %q", b)
+	}
 	bs.sendNotifyMsg(b)
 }
 
@@ -105,7 +131,7 @@ func (bs *BackendServer) SendInUseOtherUserErrorMessage(msg string) {
 
 // GotCommandMsg parses the incoming message b as a JSON Command and
 // calls GotCommand with it.
-func (bs *BackendServer) GotCommandMsg(b []byte) error {
+func (bs *BackendServer) GotCommandMsg(ctx context.Context, b []byte) error {
 	cmd := &Command{}
 	if len(b) == 0 {
 		return nil
@@ -113,15 +139,19 @@ func (bs *BackendServer) GotCommandMsg(b []byte) error {
 	if err := json.Unmarshal(b, cmd); err != nil {
 		return err
 	}
-	return bs.GotCommand(cmd)
+	return bs.GotCommand(ctx, cmd)
 }
 
-func (bs *BackendServer) GotFakeCommand(cmd *Command) error {
+func (bs *BackendServer) GotFakeCommand(ctx context.Context, cmd *Command) error {
 	cmd.Version = version.Long
-	return bs.GotCommand(cmd)
+	return bs.GotCommand(ctx, cmd)
 }
 
-func (bs *BackendServer) GotCommand(cmd *Command) error {
+// ErrMsgPermissionDenied is the Notify.ErrMessage value used an
+// operation was done from a user/context that didn't have permission.
+const ErrMsgPermissionDenied = "permission denied"
+
+func (bs *BackendServer) GotCommand(ctx context.Context, cmd *Command) error {
 	if cmd.Version != version.Long && !cmd.AllowVersionSkew {
 		vs := fmt.Sprintf("GotCommand: Version mismatch! frontend=%#v backend=%#v",
 			cmd.Version, version.Long)
@@ -135,12 +165,30 @@ func (bs *BackendServer) GotCommand(cmd *Command) error {
 		})
 		return nil
 	}
+
+	// TODO(bradfitz): finish plumbing context down to all the methods below;
+	// currently we just check for read-only contexts in this method and
+	// then never use contexts again.
+
+	// Actions permitted with a read-only context:
+	if c := cmd.RequestEngineStatus; c != nil {
+		bs.b.RequestEngineStatus()
+		return nil
+	} else if c := cmd.Ping; c != nil {
+		bs.b.Ping(c.IP, c.UseTSMP)
+		return nil
+	}
+
+	if IsReadonlyContext(ctx) {
+		msg := ErrMsgPermissionDenied
+		bs.send(Notify{ErrMessage: &msg})
+		return nil
+	}
+
 	if cmd.Quit != nil {
 		bs.GotQuit = true
 		return errors.New("Quit command received")
-	}
-
-	if c := cmd.Start; c != nil {
+	} else if c := cmd.Start; c != nil {
 		opts := c.Opts
 		opts.Notify = bs.send
 		return bs.b.Start(opts)
@@ -159,27 +207,17 @@ func (bs *BackendServer) GotCommand(cmd *Command) error {
 	} else if c := cmd.SetWantRunning; c != nil {
 		bs.b.SetWantRunning(*c)
 		return nil
-	} else if c := cmd.RequestEngineStatus; c != nil {
-		bs.b.RequestEngineStatus()
-		return nil
-	} else if c := cmd.RequestStatus; c != nil {
-		bs.b.RequestStatus()
-		return nil
 	} else if c := cmd.FakeExpireAfter; c != nil {
 		bs.b.FakeExpireAfter(c.Duration)
 		return nil
-	} else if c := cmd.Ping; c != nil {
-		bs.b.Ping(c.IP)
-		return nil
-	} else {
-		return fmt.Errorf("BackendServer.Do: no command specified")
 	}
+	return fmt.Errorf("BackendServer.Do: no command specified")
 }
 
-func (bs *BackendServer) Reset() error {
+func (bs *BackendServer) Reset(ctx context.Context) error {
 	// Tell the backend we got a Logout command, which will cause it
 	// to forget all its authentication information.
-	return bs.GotFakeCommand(&Command{Logout: &NoArgs{}})
+	return bs.GotFakeCommand(ctx, &Command{Logout: &NoArgs{}})
 }
 
 type BackendClient struct {
@@ -204,6 +242,9 @@ func (bc *BackendClient) GotNotifyMsg(b []byte) {
 		// not interesting
 		return
 	}
+	if bytes.Contains(b, jsonEscapedZero) {
+		log.Printf("[unexpected] zero byte in BackendClient.GotNotifyMsg message: %q", b)
+	}
 	n := Notify{}
 	if err := json.Unmarshal(b, &n); err != nil {
 		log.Fatalf("BackendClient.Notify: cannot decode message (length=%d)\n%#v", len(b), string(b))
@@ -230,6 +271,9 @@ func (bc *BackendClient) send(cmd Command) {
 	if err != nil {
 		log.Fatalf("Failed json.Marshal(cmd): %v\n%#v\n", err, cmd)
 	}
+	if bytes.Contains(b, jsonEscapedZero) {
+		log.Printf("[unexpected] zero byte in BackendClient.send command: %q", b)
+	}
 	bc.sendCommandMsg(b)
 }
 
@@ -253,7 +297,7 @@ func (bc *BackendClient) StartLoginInteractive() {
 	bc.send(Command{StartLoginInteractive: &NoArgs{}})
 }
 
-func (bc *BackendClient) Login(token *oauth2.Token) {
+func (bc *BackendClient) Login(token *tailcfg.Oauth2Token) {
 	bc.send(Command{Login: token})
 }
 
@@ -277,8 +321,11 @@ func (bc *BackendClient) FakeExpireAfter(x time.Duration) {
 	bc.send(Command{FakeExpireAfter: &FakeExpireAfterArgs{Duration: x}})
 }
 
-func (bc *BackendClient) Ping(ip string) {
-	bc.send(Command{Ping: &PingArgs{IP: ip}})
+func (bc *BackendClient) Ping(ip string, useTSMP bool) {
+	bc.send(Command{Ping: &PingArgs{
+		IP:      ip,
+		UseTSMP: useTSMP,
+	}})
 }
 
 func (bc *BackendClient) SetWantRunning(v bool) {

ipn/message_test.go

@@ -6,18 +6,17 @@ package ipn
 
 import (
 	"bytes"
+	"context"
 	"testing"
 	"time"
 
-	"golang.org/x/oauth2"
+	"tailscale.com/tailcfg"
 	"tailscale.com/tstest"
 )
 
 func TestReadWrite(t *testing.T) {
 	tstest.PanicOnLog()
-
-	rc := tstest.NewResourceCheck()
-	defer rc.Assert(t)
+	tstest.ResourceCheck(t)
 
 	buf := bytes.Buffer{}
 	err := WriteMsg(&buf, []byte("Test string1"))
@@ -63,9 +62,7 @@ func TestReadWrite(t *testing.T) {
 
 func TestClientServer(t *testing.T) {
 	tstest.PanicOnLog()
-
-	rc := tstest.NewResourceCheck()
-	defer rc.Assert(t)
+	tstest.ResourceCheck(t)
 
 	b := &FakeBackend{}
 	var bs *BackendServer
@@ -81,7 +78,7 @@ func TestClientServer(t *testing.T) {
 		serverToClientCh <- append([]byte{}, b...)
 	}
 	clientToServer := func(b []byte) {
-		bs.GotCommandMsg(b)
+		bs.GotCommandMsg(context.TODO(), b)
 	}
 	slogf := func(fmt string, args ...interface{}) {
 		t.Logf("s: "+fmt, args...)
@@ -179,7 +176,7 @@ func TestClientServer(t *testing.T) {
 	h.Logout()
 	flushUntil(NeedsLogin)
 
-	h.Login(&oauth2.Token{
+	h.Login(&tailcfg.Oauth2Token{
 		AccessToken: "google_id_token",
 		TokenType:   GoogleIDTokenType,
 	})

ipn/prefs.go

@@ -5,6 +5,7 @@
 package ipn
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -14,10 +15,11 @@ import (
 	"runtime"
 	"strings"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
+	"inet.af/netaddr"
 	"tailscale.com/atomicfile"
-	"tailscale.com/control/controlclient"
-	"tailscale.com/wgengine/router"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/persist"
+	"tailscale.com/types/preftype"
 )
 
 //go:generate go run tailscale.com/cmd/cloner -type=Prefs -output=prefs_clone.go
@@ -27,8 +29,10 @@ type Prefs struct {
 	// ControlURL is the URL of the control server to use.
 	ControlURL string
 
-	// RouteAll specifies whether to accept subnet and default routes
-	// advertised by other nodes on the Tailscale network.
+	// RouteAll specifies whether to accept subnets advertised by
+	// other nodes on the Tailscale network. Note that this does not
+	// include default routes (0.0.0.0/0 and ::/0), those are
+	// controlled by ExitNodeID/IP below.
 	RouteAll bool
 
 	// AllowSingleHosts specifies whether to install routes for each
@@ -43,6 +47,24 @@ type Prefs struct {
 	// packets stop flowing. What's up with that?
 	AllowSingleHosts bool
 
+	// ExitNodeID and ExitNodeIP specify the node that should be used
+	// as an exit node for internet traffic. At most one of these
+	// should be non-zero.
+	//
+	// The preferred way to express the chosen node is ExitNodeID, but
+	// in some cases it's not possible to use that ID (e.g. in the
+	// linux CLI, before tailscaled has a netmap). For those
+	// situations, we allow specifying the exit node by IP, and
+	// ipnlocal.LocalBackend will translate the IP into an ID when the
+	// node is found in the netmap.
+	//
+	// If the selected exit node doesn't exist (e.g. it's not part of
+	// the current tailnet), or it doesn't offer exit node services, a
+	// blackhole route will be installed on the local system to
+	// prevent any traffic escaping to the local network.
+	ExitNodeID tailcfg.StableNodeID
+	ExitNodeIP netaddr.IP
+
 	// CorpDNS specifies whether to install the Tailscale network's
 	// DNS configuration, if it exists.
 	CorpDNS bool
@@ -54,7 +76,7 @@ type Prefs struct {
 	// ShieldsUp indicates whether to block all incoming connections,
 	// regardless of the control-provided packet filter. If false, we
 	// use the packet filter as provided. If true, we block incoming
-	// connections.
+	// connections. This overrides tailcfg.Hostinfo's ShieldsUp.
 	ShieldsUp bool
 
 	// AdvertiseTags specifies groups that this node wants to join, for
@@ -99,7 +121,7 @@ type Prefs struct {
 	// AdvertiseRoutes specifies CIDR prefixes to advertise into the
 	// Tailscale network as reachable through the current
 	// node.
-	AdvertiseRoutes []wgcfg.CIDR
+	AdvertiseRoutes []netaddr.IPPrefix
 
 	// NoSNAT specifies whether to source NAT traffic going to
 	// destinations in AdvertiseRoutes. The default is to apply source
@@ -115,14 +137,14 @@ type Prefs struct {
 
 	// NetfilterMode specifies how much to manage netfilter rules for
 	// Tailscale, if at all.
-	NetfilterMode router.NetfilterMode
+	NetfilterMode preftype.NetfilterMode
 
 	// The Persist field is named 'Config' in the file for backward
 	// compatibility with earlier versions.
 	// TODO(apenwarr): We should move this out of here, it's not a pref.
 	//  We can maybe do that once we're sure which module should persist
 	//  it (backend or frontend?)
-	Persist *controlclient.Persist `json:"Config"`
+	Persist *persist.Persist `json:"Config"`
 }
 
 // IsEmpty reports whether p is nil or pointing to a Prefs zero value.
@@ -146,15 +168,26 @@ func (p *Prefs) pretty(goos string) string {
 	if p.ShieldsUp {
 		sb.WriteString("shields=true ")
 	}
+	if !p.ExitNodeIP.IsZero() {
+		fmt.Fprintf(&sb, "exit=%v ", p.ExitNodeIP)
+	} else if !p.ExitNodeID.IsZero() {
+		fmt.Fprintf(&sb, "exit=%v ", p.ExitNodeID)
+	}
 	if len(p.AdvertiseRoutes) > 0 || goos == "linux" {
 		fmt.Fprintf(&sb, "routes=%v ", p.AdvertiseRoutes)
 	}
 	if len(p.AdvertiseRoutes) > 0 || p.NoSNAT {
 		fmt.Fprintf(&sb, "snat=%v ", !p.NoSNAT)
 	}
+	if len(p.AdvertiseTags) > 0 {
+		fmt.Fprintf(&sb, "tags=%s ", strings.Join(p.AdvertiseTags, ","))
+	}
 	if goos == "linux" {
 		fmt.Fprintf(&sb, "nf=%v ", p.NetfilterMode)
 	}
+	if p.ControlURL != "" && p.ControlURL != "https://login.tailscale.com" {
+		fmt.Fprintf(&sb, "url=%q ", p.ControlURL)
+	}
 	if p.Persist != nil {
 		sb.WriteString(p.Persist.Pretty())
 	} else {
@@ -184,6 +217,8 @@ func (p *Prefs) Equals(p2 *Prefs) bool {
 		p.ControlURL == p2.ControlURL &&
 		p.RouteAll == p2.RouteAll &&
 		p.AllowSingleHosts == p2.AllowSingleHosts &&
+		p.ExitNodeID == p2.ExitNodeID &&
+		p.ExitNodeIP == p2.ExitNodeIP &&
 		p.CorpDNS == p2.CorpDNS &&
 		p.WantRunning == p2.WantRunning &&
 		p.NotepadURLs == p2.NotepadURLs &&
@@ -199,12 +234,12 @@ func (p *Prefs) Equals(p2 *Prefs) bool {
 		p.Persist.Equals(p2.Persist)
 }
 
-func compareIPNets(a, b []wgcfg.CIDR) bool {
+func compareIPNets(a, b []netaddr.IPPrefix) bool {
 	if len(a) != len(b) {
 		return false
 	}
 	for i := range a {
-		if !a[i].IP.Equal(b[i].IP) || a[i].Mask != b[i].Mask {
+		if a[i] != b[i] {
 			return false
 		}
 	}
@@ -233,7 +268,7 @@ func NewPrefs() *Prefs {
 		AllowSingleHosts: true,
 		CorpDNS:          true,
 		WantRunning:      true,
-		NetfilterMode:    router.NetfilterOn,
+		NetfilterMode:    preftype.NetfilterOn,
 	}
 }
 
@@ -245,7 +280,7 @@ func PrefsFromBytes(b []byte, enforceDefaults bool) (*Prefs, error) {
 	if len(b) == 0 {
 		return p, nil
 	}
-	persist := &controlclient.Persist{}
+	persist := &persist.Persist{}
 	err := json.Unmarshal(b, persist)
 	if err == nil && (persist.Provider != "" || persist.LoginName != "") {
 		// old-style relaynode config; import it
@@ -270,6 +305,14 @@ func LoadPrefs(filename string) (*Prefs, error) {
 	if err != nil {
 		return nil, fmt.Errorf("LoadPrefs open: %w", err) // err includes path
 	}
+	if bytes.Contains(data, jsonEscapedZero) {
+		// Tailscale 1.2.0 - 1.2.8 on Windows had a memory corruption bug
+		// in the backend process that ended up sending NULL bytes over JSON
+		// to the frontend which wrote them out to JSON files on disk.
+		// So if we see one, treat is as corrupt and the user will need
+		// to log in again. (better than crashing)
+		return nil, os.ErrNotExist
+	}
 	p, err := PrefsFromBytes(data, false)
 	if err != nil {
 		return nil, fmt.Errorf("LoadPrefs(%q) decode: %w", filename, err)
@@ -281,7 +324,7 @@ func SavePrefs(filename string, p *Prefs) {
 	log.Printf("Saving prefs %v %v\n", filename, p.Pretty())
 	data := p.ToBytes()
 	os.MkdirAll(filepath.Dir(filename), 0700)
-	if err := atomicfile.WriteFile(filename, data, 0666); err != nil {
+	if err := atomicfile.WriteFile(filename, data, 0600); err != nil {
 		log.Printf("SavePrefs: %v\n", err)
 	}
 }

ipn/prefs_clone.go

@@ -7,9 +7,10 @@
 package ipn
 
 import (
-	"github.com/tailscale/wireguard-go/wgcfg"
-	"tailscale.com/control/controlclient"
-	"tailscale.com/wgengine/router"
+	"inet.af/netaddr"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/persist"
+	"tailscale.com/types/preftype"
 )
 
 // Clone makes a deep copy of Prefs.
@@ -23,7 +24,7 @@ func (src *Prefs) Clone() *Prefs {
 	dst.AdvertiseTags = append(src.AdvertiseTags[:0:0], src.AdvertiseTags...)
 	dst.AdvertiseRoutes = append(src.AdvertiseRoutes[:0:0], src.AdvertiseRoutes...)
 	if dst.Persist != nil {
-		dst.Persist = new(controlclient.Persist)
+		dst.Persist = new(persist.Persist)
 		*dst.Persist = *src.Persist
 	}
 	return dst
@@ -35,6 +36,8 @@ var _PrefsNeedsRegeneration = Prefs(struct {
 	ControlURL       string
 	RouteAll         bool
 	AllowSingleHosts bool
+	ExitNodeID       tailcfg.StableNodeID
+	ExitNodeIP       netaddr.IP
 	CorpDNS          bool
 	WantRunning      bool
 	ShieldsUp        bool
@@ -44,8 +47,8 @@ var _PrefsNeedsRegeneration = Prefs(struct {
 	DeviceModel      string
 	NotepadURLs      bool
 	ForceDaemon      bool
-	AdvertiseRoutes  []wgcfg.CIDR
+	AdvertiseRoutes  []netaddr.IPPrefix
 	NoSNAT           bool
-	NetfilterMode    router.NetfilterMode
-	Persist          *controlclient.Persist
+	NetfilterMode    preftype.NetfilterMode
+	Persist          *persist.Persist
 }{})

ipn/prefs_test.go

@@ -7,15 +7,18 @@ package ipn
 import (
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"reflect"
 	"testing"
 	"time"
 
-	"github.com/tailscale/wireguard-go/wgcfg"
-	"tailscale.com/control/controlclient"
+	"inet.af/netaddr"
+	"tailscale.com/tailcfg"
 	"tailscale.com/tstest"
-	"tailscale.com/wgengine/router"
+	"tailscale.com/types/persist"
+	"tailscale.com/types/preftype"
+	"tailscale.com/types/wgkey"
 )
 
 func fieldsOf(t reflect.Type) (fields []string) {
@@ -28,15 +31,15 @@ func fieldsOf(t reflect.Type) (fields []string) {
 func TestPrefsEqual(t *testing.T) {
 	tstest.PanicOnLog()
 
-	prefsHandles := []string{"ControlURL", "RouteAll", "AllowSingleHosts", "CorpDNS", "WantRunning", "ShieldsUp", "AdvertiseTags", "Hostname", "OSVersion", "DeviceModel", "NotepadURLs", "ForceDaemon", "AdvertiseRoutes", "NoSNAT", "NetfilterMode", "Persist"}
+	prefsHandles := []string{"ControlURL", "RouteAll", "AllowSingleHosts", "ExitNodeID", "ExitNodeIP", "CorpDNS", "WantRunning", "ShieldsUp", "AdvertiseTags", "Hostname", "OSVersion", "DeviceModel", "NotepadURLs", "ForceDaemon", "AdvertiseRoutes", "NoSNAT", "NetfilterMode", "Persist"}
 	if have := fieldsOf(reflect.TypeOf(Prefs{})); !reflect.DeepEqual(have, prefsHandles) {
 		t.Errorf("Prefs.Equal check might be out of sync\nfields: %q\nhandled: %q\n",
 			have, prefsHandles)
 	}
 
-	nets := func(strs ...string) (ns []wgcfg.CIDR) {
+	nets := func(strs ...string) (ns []netaddr.IPPrefix) {
 		for _, s := range strs {
-			n, err := wgcfg.ParseCIDR(s)
+			n, err := netaddr.ParseIPPrefix(s)
 			if err != nil {
 				panic(err)
 			}
@@ -97,6 +100,28 @@ func TestPrefsEqual(t *testing.T) {
 			true,
 		},
 
+		{
+			&Prefs{ExitNodeID: "n1234"},
+			&Prefs{},
+			false,
+		},
+		{
+			&Prefs{ExitNodeID: "n1234"},
+			&Prefs{ExitNodeID: "n1234"},
+			true,
+		},
+
+		{
+			&Prefs{ExitNodeIP: netaddr.MustParseIP("1.2.3.4")},
+			&Prefs{},
+			false,
+		},
+		{
+			&Prefs{ExitNodeIP: netaddr.MustParseIP("1.2.3.4")},
+			&Prefs{ExitNodeIP: netaddr.MustParseIP("1.2.3.4")},
+			true,
+		},
+
 		{
 			&Prefs{CorpDNS: true},
 			&Prefs{CorpDNS: false},
@@ -165,12 +190,12 @@ func TestPrefsEqual(t *testing.T) {
 
 		{
 			&Prefs{AdvertiseRoutes: nil},
-			&Prefs{AdvertiseRoutes: []wgcfg.CIDR{}},
+			&Prefs{AdvertiseRoutes: []netaddr.IPPrefix{}},
 			true,
 		},
 		{
-			&Prefs{AdvertiseRoutes: []wgcfg.CIDR{}},
-			&Prefs{AdvertiseRoutes: []wgcfg.CIDR{}},
+			&Prefs{AdvertiseRoutes: []netaddr.IPPrefix{}},
+			&Prefs{AdvertiseRoutes: []netaddr.IPPrefix{}},
 			true,
 		},
 		{
@@ -190,24 +215,24 @@ func TestPrefsEqual(t *testing.T) {
 		},
 
 		{
-			&Prefs{NetfilterMode: router.NetfilterOff},
-			&Prefs{NetfilterMode: router.NetfilterOn},
+			&Prefs{NetfilterMode: preftype.NetfilterOff},
+			&Prefs{NetfilterMode: preftype.NetfilterOn},
 			false,
 		},
 		{
-			&Prefs{NetfilterMode: router.NetfilterOn},
-			&Prefs{NetfilterMode: router.NetfilterOn},
+			&Prefs{NetfilterMode: preftype.NetfilterOn},
+			&Prefs{NetfilterMode: preftype.NetfilterOn},
 			true,
 		},
 
 		{
-			&Prefs{Persist: &controlclient.Persist{}},
-			&Prefs{Persist: &controlclient.Persist{LoginName: "dave"}},
+			&Prefs{Persist: &persist.Persist{}},
+			&Prefs{Persist: &persist.Persist{LoginName: "dave"}},
 			false,
 		},
 		{
-			&Prefs{Persist: &controlclient.Persist{LoginName: "dave"}},
-			&Prefs{Persist: &controlclient.Persist{LoginName: "dave"}},
+			&Prefs{Persist: &persist.Persist{LoginName: "dave"}},
+			&Prefs{Persist: &persist.Persist{LoginName: "dave"}},
 			true,
 		},
 	}
@@ -272,7 +297,7 @@ func TestBasicPrefs(t *testing.T) {
 func TestPrefsPersist(t *testing.T) {
 	tstest.PanicOnLog()
 
-	c := controlclient.Persist{
+	c := persist.Persist{
 		LoginName: "test@example.com",
 	}
 	p := Prefs{
@@ -326,6 +351,46 @@ func TestPrefsPretty(t *testing.T) {
 			"windows",
 			"Prefs{ra=false dns=false want=true server=true Persist=nil}",
 		},
+		{
+			Prefs{
+				AllowSingleHosts: true,
+				WantRunning:      true,
+				ControlURL:       "http://localhost:1234",
+				AdvertiseTags:    []string{"tag:foo", "tag:bar"},
+			},
+			"darwin",
+			`Prefs{ra=false dns=false want=true tags=tag:foo,tag:bar url="http://localhost:1234" Persist=nil}`,
+		},
+		{
+			Prefs{
+				Persist: &persist.Persist{},
+			},
+			"linux",
+			`Prefs{ra=false mesh=false dns=false want=false routes=[] nf=off Persist{lm=, o=, n= u=""}}`,
+		},
+		{
+			Prefs{
+				Persist: &persist.Persist{
+					PrivateNodeKey: wgkey.Private{1: 1},
+				},
+			},
+			"linux",
+			`Prefs{ra=false mesh=false dns=false want=false routes=[] nf=off Persist{lm=, o=, n=[B1VKl] u=""}}`,
+		},
+		{
+			Prefs{
+				ExitNodeIP: netaddr.MustParseIP("1.2.3.4"),
+			},
+			"linux",
+			`Prefs{ra=false mesh=false dns=false want=false exit=1.2.3.4 routes=[] nf=off Persist=nil}`,
+		},
+		{
+			Prefs{
+				ExitNodeID: tailcfg.StableNodeID("myNodeABC"),
+			},
+			"linux",
+			`Prefs{ra=false mesh=false dns=false want=false exit=myNodeABC routes=[] nf=off Persist=nil}`,
+		},
 	}
 	for i, tt := range tests {
 		got := tt.p.pretty(tt.os)
@@ -345,3 +410,25 @@ func TestLoadPrefsNotExist(t *testing.T) {
 	}
 	t.Fatalf("unexpected prefs=%#v, err=%v", p, err)
 }
+
+// TestLoadPrefsFileWithZeroInIt verifies that LoadPrefs hanldes corrupted input files.
+// See issue #954 for details.
+func TestLoadPrefsFileWithZeroInIt(t *testing.T) {
+	f, err := ioutil.TempFile("", "TestLoadPrefsFileWithZeroInIt")
+	if err != nil {
+		t.Fatal(err)
+	}
+	path := f.Name()
+	if _, err := f.Write(jsonEscapedZero); err != nil {
+		t.Fatal(err)
+	}
+	f.Close()
+	defer os.Remove(path)
+
+	p, err := LoadPrefs(path)
+	if errors.Is(err, os.ErrNotExist) {
+		// expected.
+		return
+	}
+	t.Fatalf("unexpected prefs=%#v, err=%v", p, err)
+}

ipn/store.go

@@ -10,6 +10,7 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
+	"log"
 	"os"
 	"path/filepath"
 	"sync"
@@ -23,7 +24,7 @@ var ErrStateNotExist = errors.New("no state with given ID")
 
 const (
 	// MachineKeyStateKey is the key under which we store the machine key,
-	// in its wgcfg.PrivateKey.MarshalText representation.
+	// in its wgkey.Private.MarshalText representation.
 	MachineKeyStateKey = StateKey("_machinekey")
 
 	// GlobalDaemonStateKey is the ipn.StateKey that tailscaled
@@ -100,6 +101,14 @@ func (s *FileStore) String() string { return fmt.Sprintf("FileStore(%q)", s.path
 // NewFileStore returns a new file store that persists to path.
 func NewFileStore(path string) (*FileStore, error) {
 	bs, err := ioutil.ReadFile(path)
+
+	// Treat an empty file as a missing file.
+	// (https://github.com/tailscale/tailscale/issues/895#issuecomment-723255589)
+	if err == nil && len(bs) == 0 {
+		log.Printf("ipn.NewFileStore(%q): file empty; treating it like a missing file [warning]", path)
+		err = os.ErrNotExist
+	}
+
 	if err != nil {
 		if os.IsNotExist(err) {
 			// Write out an initial file, to verify that we can write

logpolicy/logpolicy.go

@@ -17,15 +17,17 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
-	"golang.org/x/crypto/ssh/terminal"
+	"golang.org/x/term"
 	"tailscale.com/atomicfile"
 	"tailscale.com/logtail"
 	"tailscale.com/logtail/filch"
@@ -35,9 +37,30 @@ import (
 	"tailscale.com/paths"
 	"tailscale.com/smallzstd"
 	"tailscale.com/types/logger"
+	"tailscale.com/util/racebuild"
+	"tailscale.com/util/winutil"
 	"tailscale.com/version"
 )
 
+var getLogTargetOnce struct {
+	sync.Once
+	v string // URL of logs server, or empty for default
+}
+
+func getLogTarget() string {
+	getLogTargetOnce.Do(func() {
+		if val, ok := os.LookupEnv("TS_LOG_TARGET"); ok {
+			getLogTargetOnce.v = val
+		} else {
+			if runtime.GOOS == "windows" {
+				getLogTargetOnce.v = winutil.GetRegString("LogTarget", "")
+			}
+		}
+	})
+
+	return getLogTargetOnce.v
+}
+
 // Config represents an instance of logs in a collection.
 type Config struct {
 	Collection string
@@ -48,7 +71,7 @@ type Config struct {
 // Policy is a logger and its public ID.
 type Policy struct {
 	// Logtail is the logger.
-	Logtail logtail.Logger
+	Logtail *logtail.Logger
 	// PublicID is the logger's instance identifier.
 	PublicID logtail.PublicID
 }
@@ -310,7 +333,7 @@ func tryFixLogStateLocation(dir, cmdname string) {
 // given collection name.
 func New(collection string) *Policy {
 	var lflags int
-	if terminal.IsTerminal(2) || runtime.GOOS == "windows" {
+	if term.IsTerminal(2) || runtime.GOOS == "windows" {
 		lflags = 0
 	} else {
 		lflags = log.LstdFlags
@@ -337,6 +360,18 @@ func New(collection string) *Policy {
 	tryFixLogStateLocation(dir, cmdName)
 
 	cfgPath := filepath.Join(dir, fmt.Sprintf("%s.log.conf", cmdName))
+
+	// The Windows service previously ran as tailscale-ipn.exe, so
+	// let's keep using that log base name if it exists.
+	if runtime.GOOS == "windows" && cmdName == "tailscaled" {
+		const oldCmdName = "tailscale-ipn"
+		oldPath := filepath.Join(dir, oldCmdName+".log.conf")
+		if fi, err := os.Stat(oldPath); err == nil && fi.Mode().IsRegular() {
+			cfgPath = oldPath
+			cmdName = oldCmdName
+		}
+	}
+
 	var oldc *Config
 	data, err := ioutil.ReadFile(cfgPath)
 	if err != nil {
@@ -386,17 +421,24 @@ func New(collection string) *Policy {
 		HTTPC: &http.Client{Transport: newLogtailTransport(logtail.DefaultHost)},
 	}
 
+	if val := getLogTarget(); val != "" {
+		log.Println("You have enabled a non-default log target. Doing without being told to by Tailscale staff or your network administrator will make getting support difficult.")
+		c.BaseURL = val
+		u, _ := url.Parse(val)
+		c.HTTPC = &http.Client{Transport: newLogtailTransport(u.Host)}
+	}
+
 	filchBuf, filchErr := filch.New(filepath.Join(dir, cmdName), filch.Options{})
 	if filchBuf != nil {
 		c.Buffer = filchBuf
 	}
-	lw := logtail.Log(c, log.Printf)
+	lw := logtail.NewLogger(c, log.Printf)
 	log.SetFlags(0) // other logflags are set on console, not here
 	log.SetOutput(lw)
 
 	log.Printf("Program starting: v%v, Go %v: %#v",
 		version.Long,
-		strings.TrimPrefix(runtime.Version(), "go"),
+		goVersion(),
 		os.Args)
 	log.Printf("LogID: %v", newc.PublicID)
 	if filchErr != nil {
@@ -412,6 +454,15 @@ func New(collection string) *Policy {
 	}
 }
 
+// SetVerbosityLevel controls the verbosity level that should be
+// written to stderr. 0 is the default (not verbose). Levels 1 or higher
+// are increasingly verbose.
+//
+// It should not be changed concurrently with log writes.
+func (p *Policy) SetVerbosityLevel(level int) {
+	p.Logtail.SetVerbosityLevel(level)
+}
+
 // Close immediately shuts down the logger.
 func (p *Policy) Close() {
 	ctx, cancel := context.WithCancel(context.Background())
@@ -479,3 +530,11 @@ func newLogtailTransport(host string) *http.Transport {
 
 	return tr
 }
+
+func goVersion() string {
+	v := strings.TrimPrefix(runtime.Version(), "go")
+	if racebuild.On {
+		return v + "-race"
+	}
+	return v
+}

logtail/example/logtail/logtail.go

@@ -31,7 +31,7 @@ func main() {
 		log.Fatalf("logtail: bad -privateid: %v", err)
 	}
 
-	logger := logtail.Log(logtail.Config{
+	logger := logtail.NewLogger(logtail.Config{
 		Collection: *collection,
 		PrivateID:  id,
 	}, log.Printf)

logtail/filch/filch.go

@@ -131,11 +131,11 @@ func New(filePrefix string, opts Options) (f *Filch, err error) {
 	path1 := filePrefix + ".log1.txt"
 	path2 := filePrefix + ".log2.txt"
 
-	f1, err = os.OpenFile(path1, os.O_CREATE|os.O_RDWR, 0666)
+	f1, err = os.OpenFile(path1, os.O_CREATE|os.O_RDWR, 0600)
 	if err != nil {
 		return nil, err
 	}
-	f2, err = os.OpenFile(path2, os.O_CREATE|os.O_RDWR, 0666)
+	f2, err = os.OpenFile(path2, os.O_CREATE|os.O_RDWR, 0600)
 	if err != nil {
 		return nil, err
 	}

logtail/logtail.go

@@ -14,44 +14,19 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
+	"strconv"
 	"time"
 
 	"tailscale.com/logtail/backoff"
+	"tailscale.com/net/interfaces"
 	tslogger "tailscale.com/types/logger"
+	"tailscale.com/wgengine/monitor"
 )
 
 // DefaultHost is the default host name to upload logs to when
 // Config.BaseURL isn't provided.
 const DefaultHost = "log.tailscale.io"
 
-type Logger interface {
-	// Write logs an encoded JSON blob.
-	//
-	// If the []byte passed to Write is not an encoded JSON blob,
-	// then contents is fit into a JSON blob and written.
-	//
-	// This is intended as an interface for the stdlib "log" package.
-	Write([]byte) (int, error)
-
-	// Flush uploads all logs to the server.
-	// It blocks until complete or there is an unrecoverable error.
-	Flush() error
-
-	// Shutdown gracefully shuts down the logger while completing any
-	// remaining uploads.
-	//
-	// It will block, continuing to try and upload unless the passed
-	// context object interrupts it by being done.
-	// If the shutdown is interrupted, an error is returned.
-	Shutdown(context.Context) error
-
-	// Close shuts down this logger object, the background log uploader
-	// process, and any associated goroutines.
-	//
-	// DEPRECATED: use Shutdown
-	Close()
-}
-
 type Encoder interface {
 	EncodeAll(src, dst []byte) []byte
 	Close() error
@@ -66,15 +41,16 @@ type Config struct {
 	LowMemory      bool             // if true, logtail minimizes memory use
 	TimeNow        func() time.Time // if set, subsitutes uses of time.Now
 	Stderr         io.Writer        // if set, logs are sent here instead of os.Stderr
+	StderrLevel    int              // max verbosity level to write to stderr; 0 means the non-verbose messages only
 	Buffer         Buffer           // temp storage, if nil a MemoryBuffer
 	NewZstdEncoder func() Encoder   // if set, used to compress logs for transmission
 
-	// DrainLogs, if non-nil, disables autmatic uploading of new logs,
+	// DrainLogs, if non-nil, disables automatic uploading of new logs,
 	// so that logs are only uploaded when a token is sent to DrainLogs.
 	DrainLogs <-chan struct{}
 }
 
-func Log(cfg Config, logf tslogger.Logf) Logger {
+func NewLogger(cfg Config, logf tslogger.Logf) *Logger {
 	if cfg.BaseURL == "" {
 		cfg.BaseURL = "https://" + DefaultHost
 	}
@@ -94,8 +70,9 @@ func Log(cfg Config, logf tslogger.Logf) Logger {
 		}
 		cfg.Buffer = NewMemoryBuffer(pendingSize)
 	}
-	l := &logger{
+	l := &Logger{
 		stderr:         cfg.Stderr,
+		stderrLevel:    cfg.StderrLevel,
 		httpc:          cfg.HTTPC,
 		url:            cfg.BaseURL + "/c/" + cfg.Collection + "/" + cfg.PrivateID.String(),
 		lowMem:         cfg.LowMemory,
@@ -122,12 +99,16 @@ func Log(cfg Config, logf tslogger.Logf) Logger {
 	return l
 }
 
-type logger struct {
+// Logger writes logs, splitting them as configured between local
+// logging facilities and uploading to a log server.
+type Logger struct {
 	stderr         io.Writer
+	stderrLevel    int
 	httpc          *http.Client
 	url            string
 	lowMem         bool
 	skipClientTime bool
+	linkMonitor    *monitor.Mon
 	buffer         Buffer
 	sent           chan struct{}   // signal to speed up drain
 	drainLogs      <-chan struct{} // if non-nil, external signal to attempt a drain
@@ -141,7 +122,30 @@ type logger struct {
 	shutdownDone  chan struct{} // closd when shutdown complete
 }
 
-func (l *logger) Shutdown(ctx context.Context) error {
+// SetVerbosityLevel controls the verbosity level that should be
+// written to stderr. 0 is the default (not verbose). Levels 1 or higher
+// are increasingly verbose.
+//
+// It should not be changed concurrently with log writes.
+func (l *Logger) SetVerbosityLevel(level int) {
+	l.stderrLevel = level
+}
+
+// SetLinkMonitor sets the optional the link monitor.
+//
+// It should not be changed concurrently with log writes and should
+// only be set once.
+func (l *Logger) SetLinkMonitor(lm *monitor.Mon) {
+	l.linkMonitor = lm
+}
+
+// Shutdown gracefully shuts down the logger while completing any
+// remaining uploads.
+//
+// It will block, continuing to try and upload unless the passed
+// context object interrupts it by being done.
+// If the shutdown is interrupted, an error is returned.
+func (l *Logger) Shutdown(ctx context.Context) error {
 	done := make(chan struct{})
 	go func() {
 		select {
@@ -163,7 +167,11 @@ func (l *logger) Shutdown(ctx context.Context) error {
 	return nil
 }
 
-func (l *logger) Close() {
+// Close shuts down this logger object, the background log uploader
+// process, and any associated goroutines.
+//
+// Deprecated: use Shutdown
+func (l *Logger) Close() {
 	l.Shutdown(context.Background())
 }
 
@@ -174,7 +182,7 @@ func (l *logger) Close() {
 //
 // If the caller provides a DrainLogs channel, then unblock-drain-on-Write
 // is disabled, and it is up to the caller to trigger unblock the drain.
-func (l *logger) drainBlock() (shuttingDown bool) {
+func (l *Logger) drainBlock() (shuttingDown bool) {
 	if l.drainLogs == nil {
 		select {
 		case <-l.shutdownStart:
@@ -193,7 +201,7 @@ func (l *logger) drainBlock() (shuttingDown bool) {
 
 // drainPending drains and encodes a batch of logs from the buffer for upload.
 // If no logs are available, drainPending blocks until logs are available.
-func (l *logger) drainPending() (res []byte) {
+func (l *Logger) drainPending() (res []byte) {
 	buf := new(bytes.Buffer)
 	entries := 0
 
@@ -254,13 +262,22 @@ func (l *logger) drainPending() (res []byte) {
 }
 
 // This is the goroutine that repeatedly uploads logs in the background.
-func (l *logger) uploading(ctx context.Context) {
+func (l *Logger) uploading(ctx context.Context) {
 	defer close(l.shutdownDone)
 
 	for {
 		body := l.drainPending()
-		if l.zstdEncoder != nil {
-			body = l.zstdEncoder.EncodeAll(body, nil)
+		origlen := -1 // sentinel value: uncompressed
+		// Don't attempt to compress tiny bodies; not worth the CPU cycles.
+		if l.zstdEncoder != nil && len(body) > 256 {
+			zbody := l.zstdEncoder.EncodeAll(body, nil)
+			// Only send it compressed if the bandwidth savings are sufficient.
+			// Just the extra headers associated with enabling compression
+			// are 50 bytes by themselves.
+			if len(body)-len(zbody) > 64 {
+				origlen = len(body)
+				body = zbody
+			}
 		}
 
 		for len(body) > 0 {
@@ -269,8 +286,13 @@ func (l *logger) uploading(ctx context.Context) {
 				return
 			default:
 			}
-			uploaded, err := l.upload(ctx, body)
+			uploaded, err := l.upload(ctx, body, origlen)
 			if err != nil {
+				if !l.internetUp() {
+					fmt.Fprintf(l.stderr, "logtail: internet down; waiting\n")
+					l.awaitInternetUp(ctx)
+					continue
+				}
 				fmt.Fprintf(l.stderr, "logtail: upload: %v\n", err)
 			}
 			l.bo.BackOff(ctx, err)
@@ -287,7 +309,38 @@ func (l *logger) uploading(ctx context.Context) {
 	}
 }
 
-func (l *logger) upload(ctx context.Context, body []byte) (uploaded bool, err error) {
+func (l *Logger) internetUp() bool {
+	if l.linkMonitor == nil {
+		// No way to tell, so assume it is.
+		return true
+	}
+	return l.linkMonitor.InterfaceState().AnyInterfaceUp()
+}
+
+func (l *Logger) awaitInternetUp(ctx context.Context) {
+	upc := make(chan bool, 1)
+	defer l.linkMonitor.RegisterChangeCallback(func(changed bool, st *interfaces.State) {
+		if st.AnyInterfaceUp() {
+			select {
+			case upc <- true:
+			default:
+			}
+		}
+	})()
+	if l.internetUp() {
+		return
+	}
+	select {
+	case <-upc:
+		fmt.Fprintf(l.stderr, "logtail: internet back up\n")
+	case <-ctx.Done():
+	}
+}
+
+// upload uploads body to the log server.
+// origlen indicates the pre-compression body length.
+// origlen of -1 indicates that the body is not compressed.
+func (l *Logger) upload(ctx context.Context, body []byte, origlen int) (uploaded bool, err error) {
 	req, err := http.NewRequest("POST", l.url, bytes.NewReader(body))
 	if err != nil {
 		// I know of no conditions under which this could fail.
@@ -295,8 +348,9 @@ func (l *logger) upload(ctx context.Context, body []byte) (uploaded bool, err er
 		// TODO record logs to disk
 		panic("logtail: cannot build http request: " + err.Error())
 	}
-	if l.zstdEncoder != nil {
+	if origlen != -1 {
 		req.Header.Add("Content-Encoding", "zstd")
+		req.Header.Add("Orig-Content-Length", strconv.Itoa(origlen))
 	}
 	req.Header["User-Agent"] = nil // not worth writing one; save some bytes
 
@@ -306,7 +360,7 @@ func (l *logger) upload(ctx context.Context, body []byte) (uploaded bool, err er
 	req = req.WithContext(ctx)
 
 	compressedNote := "not-compressed"
-	if l.zstdEncoder != nil {
+	if origlen != -1 {
 		compressedNote = "compressed"
 	}
 
@@ -333,11 +387,13 @@ func (l *logger) upload(ctx context.Context, body []byte) (uploaded bool, err er
 	return true, nil
 }
 
-func (l *logger) Flush() error {
+// Flush uploads all logs to the server.
+// It blocks until complete or there is an unrecoverable error.
+func (l *Logger) Flush() error {
 	return nil
 }
 
-func (l *logger) send(jsonBlob []byte) (int, error) {
+func (l *Logger) send(jsonBlob []byte) (int, error) {
 	n, err := l.buffer.Write(jsonBlob)
 	if l.drainLogs == nil {
 		select {
@@ -350,7 +406,7 @@ func (l *logger) send(jsonBlob []byte) (int, error) {
 
 // TODO: instead of allocating, this should probably just append
 // directly into the output log buffer.
-func (l *logger) encodeText(buf []byte, skipClientTime bool) []byte {
+func (l *Logger) encodeText(buf []byte, skipClientTime bool) []byte {
 	now := l.timeNow()
 
 	// Factor in JSON encoding overhead to try to only do one alloc
@@ -406,7 +462,7 @@ func (l *logger) encodeText(buf []byte, skipClientTime bool) []byte {
 	return b
 }
 
-func (l *logger) encode(buf []byte) []byte {
+func (l *Logger) encode(buf []byte) []byte {
 	if buf[0] != '{' {
 		return l.encodeText(buf, l.skipClientTime) // text fast-path
 	}
@@ -447,11 +503,18 @@ func (l *logger) encode(buf []byte) []byte {
 	return b
 }
 
-func (l *logger) Write(buf []byte) (int, error) {
+// Write logs an encoded JSON blob.
+//
+// If the []byte passed to Write is not an encoded JSON blob,
+// then contents is fit into a JSON blob and written.
+//
+// This is intended as an interface for the stdlib "log" package.
+func (l *Logger) Write(buf []byte) (int, error) {
 	if len(buf) == 0 {
 		return 0, nil
 	}
-	if l.stderr != nil && l.stderr != ioutil.Discard {
+	level, buf := parseAndRemoveLogLevel(buf)
+	if l.stderr != nil && l.stderr != ioutil.Discard && level <= l.stderrLevel {
 		if buf[len(buf)-1] == '\n' {
 			l.stderr.Write(buf)
 		} else {
@@ -465,3 +528,23 @@ func (l *logger) Write(buf []byte) (int, error) {
 	_, err := l.send(b)
 	return len(buf), err
 }
+
+var (
+	openBracketV = []byte("[v")
+	v1           = []byte("[v1] ")
+	v2           = []byte("[v2] ")
+)
+
+// level 0 is normal (or unknown) level; 1+ are increasingly verbose
+func parseAndRemoveLogLevel(buf []byte) (level int, cleanBuf []byte) {
+	if len(buf) == 0 || buf[0] == '{' || !bytes.Contains(buf, openBracketV) {
+		return 0, buf
+	}
+	if bytes.Contains(buf, v1) {
+		return 1, bytes.ReplaceAll(buf, v1, nil)
+	}
+	if bytes.Contains(buf, v2) {
+		return 2, bytes.ReplaceAll(buf, v2, nil)
+	}
+	return 0, buf
+}

logtail/logtail_test.go

@@ -6,6 +6,12 @@ package logtail
 
 import (
 	"context"
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 )
@@ -14,16 +20,215 @@ func TestFastShutdown(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
 
-	l := Log(Config{
-		BaseURL: "http://localhost:1234",
+	testServ := httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {}))
+	defer testServ.Close()
+
+	l := NewLogger(Config{
+		BaseURL: testServ.URL,
 	}, t.Logf)
-	l.Shutdown(ctx)
+	err := l.Shutdown(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+// maximum number of times a test will call l.Write()
+const logLines = 3
+
+type LogtailTestServer struct {
+	srv      *httptest.Server // Log server
+	uploaded chan []byte
+}
+
+func NewLogtailTestHarness(t *testing.T) (*LogtailTestServer, *Logger) {
+	ts := LogtailTestServer{}
+
+	// max channel backlog = 1 "started" + #logLines x "log line" + 1 "closed"
+	ts.uploaded = make(chan []byte, 2+logLines)
+
+	ts.srv = httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			body, err := ioutil.ReadAll(r.Body)
+			if err != nil {
+				t.Error("failed to read HTTP request")
+			}
+			ts.uploaded <- body
+		}))
+
+	t.Cleanup(ts.srv.Close)
+
+	l := NewLogger(Config{BaseURL: ts.srv.URL}, t.Logf)
+
+	// There is always an initial "logtail started" message
+	body := <-ts.uploaded
+	if !strings.Contains(string(body), "started") {
+		t.Errorf("unknown start logging statement: %q", string(body))
+	}
+
+	return &ts, l
+}
+
+func TestDrainPendingMessages(t *testing.T) {
+	ts, l := NewLogtailTestHarness(t)
+
+	for i := 0; i < logLines; i++ {
+		l.Write([]byte("log line"))
+	}
+
+	// all of the "log line" messages usually arrive at once, but poll if needed.
+	body := ""
+	for i := 0; i <= logLines; i++ {
+		body += string(<-ts.uploaded)
+		count := strings.Count(body, "log line")
+		if count == logLines {
+			break
+		}
+		// if we never find count == logLines, the test will eventually time out.
+	}
+
+	err := l.Shutdown(context.Background())
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func TestEncodeAndUploadMessages(t *testing.T) {
+	ts, l := NewLogtailTestHarness(t)
+
+	tests := []struct {
+		name string
+		log  string
+		want string
+	}{
+		{
+			"plain text",
+			"log line",
+			"log line",
+		},
+		{
+			"simple JSON",
+			`{"text": "log line"}`,
+			"log line",
+		},
+	}
+
+	for _, tt := range tests {
+		io.WriteString(l, tt.log)
+		body := <-ts.uploaded
+
+		data := make(map[string]interface{})
+		err := json.Unmarshal(body, &data)
+		if err != nil {
+			t.Error(err)
+		}
+
+		got := data["text"]
+		if got != tt.want {
+			t.Errorf("%s: got %q; want %q", tt.name, got.(string), tt.want)
+		}
+
+		ltail, ok := data["logtail"]
+		if ok {
+			logtailmap := ltail.(map[string]interface{})
+			_, ok = logtailmap["client_time"]
+			if !ok {
+				t.Errorf("%s: no client_time present", tt.name)
+			}
+		} else {
+			t.Errorf("%s: no logtail map present", tt.name)
+		}
+	}
+
+	err := l.Shutdown(context.Background())
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func TestEncodeSpecialCases(t *testing.T) {
+	ts, l := NewLogtailTestHarness(t)
+
+	// -------------------------------------------------------------------------
+
+	// JSON log message already contains a logtail field.
+	io.WriteString(l, `{"logtail": "LOGTAIL", "text": "text"}`)
+	body := <-ts.uploaded
+	data := make(map[string]interface{})
+	err := json.Unmarshal(body, &data)
+	if err != nil {
+		t.Error(err)
+	}
+	errorHasLogtail, ok := data["error_has_logtail"]
+	if ok {
+		if errorHasLogtail != "LOGTAIL" {
+			t.Errorf("error_has_logtail: got:%q; want:%q",
+				errorHasLogtail, "LOGTAIL")
+		}
+	} else {
+		t.Errorf("no error_has_logtail field: %v", data)
+	}
+
+	// -------------------------------------------------------------------------
+
+	// special characters
+	io.WriteString(l, "\b\f\n\r\t"+`"\`)
+	bodytext := string(<-ts.uploaded)
+	// json.Unmarshal would unescape the characters, we have to look at the encoded text
+	escaped := strings.Contains(bodytext, `\b\f\n\r\t\"\`)
+	if !escaped {
+		t.Errorf("special characters got %s", bodytext)
+	}
+
+	// -------------------------------------------------------------------------
+
+	// skipClientTime to omit the logtail metadata
+	l.skipClientTime = true
+	io.WriteString(l, "text")
+	body = <-ts.uploaded
+	data = make(map[string]interface{})
+	err = json.Unmarshal(body, &data)
+	if err != nil {
+		t.Error(err)
+	}
+	_, ok = data["logtail"]
+	if ok {
+		t.Errorf("skipClientTime: unexpected logtail map present: %v", data)
+	}
+
+	// -------------------------------------------------------------------------
+
+	// lowMem + long string
+	l.skipClientTime = false
+	l.lowMem = true
+	longStr := strings.Repeat("0", 512)
+	io.WriteString(l, longStr)
+	body = <-ts.uploaded
+	data = make(map[string]interface{})
+	err = json.Unmarshal(body, &data)
+	if err != nil {
+		t.Error(err)
+	}
+	text, ok := data["text"]
+	if !ok {
+		t.Errorf("lowMem: no text %v", data)
+	}
+	if n := len(text.(string)); n > 300 {
+		t.Errorf("lowMem: got %d chars; want <300 chars", n)
+	}
+
+	// -------------------------------------------------------------------------
+
+	err = l.Shutdown(context.Background())
+	if err != nil {
+		t.Error(err)
+	}
 }
 
 var sink []byte
 
 func TestLoggerEncodeTextAllocs(t *testing.T) {
-	lg := &logger{timeNow: time.Now}
+	lg := &Logger{timeNow: time.Now}
 	inBuf := []byte("some text to encode")
 	n := testing.AllocsPerRun(1000, func() {
 		sink = lg.encodeText(inBuf, false)
@@ -34,7 +239,7 @@ func TestLoggerEncodeTextAllocs(t *testing.T) {
 }
 
 func TestLoggerWriteLength(t *testing.T) {
-	lg := &logger{
+	lg := &Logger{
 		timeNow: time.Now,
 		buffer:  NewMemoryBuffer(1024),
 	}
@@ -47,3 +252,54 @@ func TestLoggerWriteLength(t *testing.T) {
 		t.Errorf("logger.Write wrote %d bytes, expected %d", n, len(inBuf))
 	}
 }
+
+func TestParseAndRemoveLogLevel(t *testing.T) {
+	tests := []struct {
+		log       string
+		wantLevel int
+		wantLog   string
+	}{
+		{
+			"no level",
+			0,
+			"no level",
+		},
+		{
+			"[v1] level 1",
+			1,
+			"level 1",
+		},
+		{
+			"level 1 [v1] ",
+			1,
+			"level 1 ",
+		},
+		{
+			"[v2] level 2",
+			2,
+			"level 2",
+		},
+		{
+			"level [v2] 2",
+			2,
+			"level 2",
+		},
+		{
+			"[v3] no level 3",
+			0,
+			"[v3] no level 3",
+		},
+	}
+
+	for _, tt := range tests {
+		gotLevel, gotLog := parseAndRemoveLogLevel([]byte(tt.log))
+		if gotLevel != tt.wantLevel {
+			t.Errorf("parseAndRemoveLogLevel(%q): got:%d; want %d",
+				tt.log, gotLevel, tt.wantLevel)
+		}
+		if string(gotLog) != tt.wantLog {
+			t.Errorf("parseAndRemoveLogLevel(%q): got:%q; want %q",
+				tt.log, gotLog, tt.wantLog)
+		}
+	}
+}

net/dns/config.go

@@ -22,8 +22,8 @@ type Config struct {
 	// Note that Nameservers may still be applied to all queries
 	// if the manager does not support per-domain settings.
 	PerDomain bool
-	// Proxied indicates whether DNS requests are proxied through a tsdns.Resolver.
-	// This enables Magic DNS.
+	// Proxied indicates whether DNS requests are proxied through a dns.Resolver.
+	// This enables MagicDNS.
 	Proxied bool
 }
 
@@ -63,9 +63,10 @@ func (lhs Config) Equal(rhs Config) bool {
 // ManagerConfig is the set of parameters from which
 // a manager implementation is chosen and initialized.
 type ManagerConfig struct {
-	// logf is the logger for the manager to use.
+	// Logf is the logger for the manager to use.
+	// It is wrapped with a "dns: " prefix.
 	Logf logger.Logf
-	// InterfaceNAme is the name of the interface with which DNS settings should be associated.
+	// InterfaceName is the name of the interface with which DNS settings should be associated.
 	InterfaceName string
 	// Cleanup indicates that the manager is created for cleanup only.
 	// A no-op manager will be instantiated if the system needs no cleanup.

net/dns/flush_windows.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package dns
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+// Flush clears the local resolver cache.
+func Flush() error {
+	out, err := exec.Command("ipconfig", "/flushdns").CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%v (output: %s)", err, out)
+	}
+	return nil
+}

net/dns/forwarder.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package tsdns
+package dns
 
 import (
 	"bytes"
@@ -163,6 +163,14 @@ func (f *forwarder) Close() {
 	f.wg.Wait()
 }
 
+func (f *forwarder) rebindFromNetworkChange() {
+	for _, c := range f.conns {
+		c.mu.Lock()
+		c.reconnectLocked()
+		c.mu.Unlock()
+	}
+}
+
 func (f *forwarder) setUpstreams(upstreams []net.Addr) {
 	f.mu.Lock()
 	f.upstreams = upstreams
@@ -308,7 +316,7 @@ func (c *fwdConn) send(packet []byte, dst net.Addr) {
 	var b *backoff.Backoff // lazily initialized, since it is not needed in the common case
 	backOff := func(err error) {
 		if b == nil {
-			b = backoff.NewBackoff("tsdns-fwdConn-send", c.logf, 30*time.Second)
+			b = backoff.NewBackoff("dns-fwdConn-send", c.logf, 30*time.Second)
 		}
 		b.BackOff(context.Background(), err)
 	}