cmd/tailscale{,d}: combine into a single binary

To reduce size, combine tailscaled and tailscale into a single
binary which will figure out what it should do based on argv[0].

Signed-off-by: Denton Gentry <dgentry@tailscale.com>

.github/workflows/go_generate.yml

@@ -1,34 +0,0 @@
-name: go generate
-
-on:
-  push:
-    branches:
-      - main
-      - "release-branch/*"
-  pull_request:
-    branches:
-      - "*"
-
-jobs:
-  check:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Set up Go
-        uses: actions/setup-go@v1
-        with:
-          go-version: 1.16
-
-      - name: Check out code
-        uses: actions/checkout@v2
-        with:
-          fetch-depth: 0
-
-      - name: check 'go generate' is clean
-        run: |
-          mkdir gentools
-          go build -o gentools/stringer golang.org/x/tools/cmd/stringer
-          PATH="$PATH:$(pwd)/gentools" go generate ./...
-          echo
-          echo
-          git diff --name-only --exit-code || (echo "The files above need updating. Please run 'go generate'."; exit 1)

.github/workflows/staticcheck.yml

@@ -31,28 +31,16 @@ jobs:
       run: "staticcheck -version"
 
     - name: Run staticcheck (linux/amd64)
-      env:
-        GOOS: linux
-        GOARCH: amd64
-      run: "staticcheck -- $(go list ./... | grep -v tempfork)"
+      run: "GOOS=linux GOARCH=amd64 staticcheck -- $(go list ./... | grep -v tempfork)"
 
     - name: Run staticcheck (darwin/amd64)
-      env:
-        GOOS: darwin
-        GOARCH: amd64
-      run: "staticcheck -- $(go list ./... | grep -v tempfork)"
+      run: "GOOS=darwin GOARCH=amd64 staticcheck -- $(go list ./... | grep -v tempfork)"
 
     - name: Run staticcheck (windows/amd64)
-      env:
-        GOOS: windows
-        GOARCH: amd64
-      run: "staticcheck -- $(go list ./... | grep -v tempfork)"
+      run: "GOOS=windows GOARCH=amd64 staticcheck -- $(go list ./... | grep -v tempfork)"
 
     - name: Run staticcheck (windows/386)
-      env:
-        GOOS: windows
-        GOARCH: "386"
-      run: "staticcheck -- $(go list ./... | grep -v tempfork)"
+      run: "GOOS=windows GOARCH=386 staticcheck -- $(go list ./... | grep -v tempfork)"
 
     - uses: k0kubun/action-slack@v2.0.0
       with:

.github/workflows/xe-experimental-vm-test.yml

@@ -1,45 +0,0 @@
-name: "integration-vms"
-
-on:
-  pull_request:
-    paths:
-      - "tstest/integration/vms/**"
-  release:
-    types: [ created ]
-
-jobs:
-  experimental-linux-vm-test:
-    # To set up a new runner, see tstest/integration/vms/runner.nix
-    runs-on: [ self-hosted, linux, vm_integration_test ]
-
-    if: "!contains(github.event.head_commit.message, '[ci skip]')"
-
-    steps:
-      - name: Checkout Code
-        uses: actions/checkout@v1
-
-      - name: Download VM Images
-        run: go test ./tstest/integration/vms -run-vm-tests -run=Download -timeout=60m -no-s3
-        env:
-          XDG_CACHE_HOME: "/var/lib/ghrunner/cache"
-
-      - name: Run VM tests
-        run: go test ./tstest/integration/vms -v -run-vm-tests
-        env:
-          TMPDIR: "/tmp"
-          XDG_CACHE_HOME: "/var/lib/ghrunner/cache"
-
-      - uses: k0kubun/action-slack@v2.0.0
-        with:
-          payload: |
-            {
-              "attachments": [{
-                "text": "${{ job.status }}: ${{ github.workflow }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ env.COMMIT_DATE }} #${{ env.COMMIT_NUMBER_OF_DAY }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'

Dockerfile

@@ -42,7 +42,8 @@ FROM golang:1.16-alpine AS build-env
 
 WORKDIR /go/src/tailscale
 
-COPY go.mod go.sum ./
+COPY go.mod .
+COPY go.sum .
 RUN go mod download
 
 COPY . .
@@ -61,6 +62,6 @@ RUN go install -tags=xversion -ldflags="\
       -X tailscale.com/version.GitCommit=$VERSION_GIT_HASH" \
       -v ./cmd/...
 
-FROM alpine:3.14
+FROM alpine:3.11
 RUN apk add --no-cache ca-certificates iptables iproute2
 COPY --from=build-env /go/bin/* /usr/local/bin/

Makefile

@@ -18,10 +18,7 @@ buildwindows:
 build386:
 	GOOS=linux GOARCH=386 go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
 
-buildlinuxarm:
-	GOOS=linux GOARCH=arm go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
-
-check: staticcheck vet depaware buildwindows build386 buildlinuxarm
+check: staticcheck vet depaware buildwindows build386
 
 staticcheck:
 	go run honnef.co/go/tools/cmd/staticcheck -- $$(go list ./... | grep -v tempfork)

VERSION.txt

@@ -1 +1 @@
-1.15.0
+1.9.0

api.md

@@ -18,7 +18,6 @@ Currently based on {some authentication method}. Visit the [admin panel](https:/
     - [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
-	- [POST tailnet ACL validate](#tailnet-acl-validate-post): run validation tests against the tailnet's existing ACL
   - [Devices](#tailnet-devices)
     - [GET tailnet devices](#tailnet-devices-get)
   - [DNS](#tailnet-dns)
@@ -472,16 +471,15 @@ Determines what rules match for a user on an ACL without saving the ACL to the s
 ##### Parameters
 
 ###### Query Parameters
-`type` - can be 'user' or 'ipport'
-`previewFor` - if type=user, a user's email. If type=ipport, a IP address + port like "10.0.0.1:80".
-The provided ACL is queried with this parameter to determine which rules match.
+`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
 ```
-curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl/preview?previewFor=user1@example.com&type=user' \
+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.
 {
@@ -511,50 +509,6 @@ Response:
 {"matches":[{"users":["*"],"ports":["*:*"],"lineNumber":19}],"user":"user1@example.com"}
 ```
 
-<a name=tailnet-acl-validate-post></a>
-
-#### `POST /api/v2/tailnet/:tailnet/acl/validate` - run validation tests against the tailnet's active ACL
-
-Runs the provided ACL tests against the tailnet's existing ACL. This endpoint does not modify the ACL in any way.
-
-##### Parameters
-
-###### POST Body
-
-The POST body should be a JSON formatted array of ACL Tests.
-
-See https://tailscale.com/kb/1018/acls for more information on the format of ACL tests.
-
-##### Example
-```
-POST /api/v2/tailnet/example.com/acl/validate
-curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl/validate' \
-  -u "tskey-yourapikey123:" \
-  --data-binary '
-{
-  [
-    {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]}
-  ]
-}'
-```
-
-Response:
-If all the tests pass, the response will be empty, with an http status code of 200.
-
-Failed test error response:
-A 400 http status code and the errors in the response body.  
-```
-{
-  "message":"test(s) failed",
-  "data":[
-           {
-             "user":"user1@example.com",
-             "errors":["address \"2.2.2.2:22\": want: Drop, got: Accept"]
-           }
-         ]
-}
-```
-
 <a name=tailnet-devices></a>
 
 ### Devices

build_dist.sh

@@ -11,36 +11,6 @@
 
 set -eu
 
-IFS=".$IFS" read -r major minor patch <VERSION.txt
-git_hash=$(git rev-parse HEAD)
-if ! git diff-index --quiet HEAD; then
-	git_hash="${git_hash}-dirty"
-fi
-base_hash=$(git rev-list --max-count=1 HEAD -- VERSION.txt)
-change_count=$(git rev-list --count HEAD "^$base_hash")
-short_hash=$(echo "$git_hash" | cut -c1-9)
+eval $(./version/version.sh)
 
-if expr "$minor" : "[0-9]*[13579]$" >/dev/null; then
-	patch="$change_count"
-	change_suffix=""
-elif [ "$change_count" != "0" ]; then
-	change_suffix="-$change_count"
-else
-	change_suffix=""
-fi
-
-long_suffix="$change_suffix-t$short_hash"
-SHORT="$major.$minor.$patch"
-LONG="${SHORT}$long_suffix"
-GIT_HASH="$git_hash"
-
-if [ "$1" = "shellvars" ]; then
-	cat <<EOF
-VERSION_SHORT="$SHORT"
-VERSION_LONG="$LONG"
-VERSION_GIT_HASH="$GIT_HASH"
-EOF
-	exit 0
-fi
-
-exec go build -ldflags "-X tailscale.com/version.Long=${LONG} -X tailscale.com/version.Short=${SHORT} -X tailscale.com/version.GitCommit=${GIT_HASH}" "$@"
+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

@@ -25,7 +25,7 @@
 
 set -eu
 
-eval $(./build_dist.sh shellvars)
+eval $(./version/version.sh)
 
 docker build \
   --build-arg VERSION_LONG=$VERSION_LONG \

client/tailscale/tailscale.go

@@ -8,7 +8,6 @@ package tailscale
 import (
 	"bytes"
 	"context"
-	"crypto/tls"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -17,19 +16,14 @@ import (
 	"net"
 	"net/http"
 	"net/url"
-	"os"
 	"strconv"
 	"strings"
-	"time"
 
-	"go4.org/mem"
 	"tailscale.com/client/tailscale/apitype"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/paths"
 	"tailscale.com/safesocket"
-	"tailscale.com/tailcfg"
-	"tailscale.com/version"
 )
 
 // TailscaledSocket is the tailscaled Unix socket.
@@ -96,9 +90,6 @@ func send(ctx context.Context, method, path string, wantStatus int, body io.Read
 		return nil, err
 	}
 	defer res.Body.Close()
-	if server := res.Header.Get("Tailscale-Version"); server != version.Long {
-		fmt.Fprintf(os.Stderr, "Warning: client version %q != tailscaled server version %q\n", version.Long, server)
-	}
 	slurp, err := ioutil.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
@@ -265,105 +256,3 @@ func Logout(ctx context.Context) error {
 	_, err := send(ctx, "POST", "/localapi/v0/logout", http.StatusNoContent, nil)
 	return err
 }
-
-// SetDNS adds a DNS TXT record for the given domain name, containing
-// the provided TXT value. The intended use case is answering
-// LetsEncrypt/ACME dns-01 challenges.
-//
-// The control plane will only permit SetDNS requests with very
-// specific names and values. The name should be
-// "_acme-challenge." + your node's MagicDNS name. It's expected that
-// clients cache the certs from LetsEncrypt (or whichever CA is
-// providing them) and only request new ones as needed; the control plane
-// rate limits SetDNS requests.
-//
-// This is a low-level interface; it's expected that most Tailscale
-// users use a higher level interface to getting/using TLS
-// certificates.
-func SetDNS(ctx context.Context, name, value string) error {
-	v := url.Values{}
-	v.Set("name", name)
-	v.Set("value", value)
-	_, err := send(ctx, "POST", "/localapi/v0/set-dns?"+v.Encode(), 200, nil)
-	return err
-}
-
-// CurrentDERPMap returns the current DERPMap that is being used by the local tailscaled.
-// It is intended to be used with netcheck to see availability of DERPs.
-func CurrentDERPMap(ctx context.Context) (*tailcfg.DERPMap, error) {
-	var derpMap tailcfg.DERPMap
-	res, err := send(ctx, "GET", "/localapi/v0/derpmap", 200, nil)
-	if err != nil {
-		return nil, err
-	}
-	if err = json.Unmarshal(res, &derpMap); err != nil {
-		return nil, fmt.Errorf("invalid derp map json: %w", err)
-	}
-	return &derpMap, nil
-}
-
-// CertPair returns a cert and private key for the provided DNS domain.
-//
-// It returns a cached certificate from disk if it's still valid.
-func CertPair(ctx context.Context, domain string) (certPEM, keyPEM []byte, err error) {
-	res, err := send(ctx, "GET", "/localapi/v0/cert/"+domain+"?type=pair", 200, nil)
-	if err != nil {
-		return nil, nil, err
-	}
-	// with ?type=pair, the response PEM is first the one private
-	// key PEM block, then the cert PEM blocks.
-	i := mem.Index(mem.B(res), mem.S("--\n--"))
-	if i == -1 {
-		return nil, nil, fmt.Errorf("unexpected output: no delimiter")
-	}
-	i += len("--\n")
-	keyPEM, certPEM = res[:i], res[i:]
-	if mem.Contains(mem.B(certPEM), mem.S(" PRIVATE KEY-----")) {
-		return nil, nil, fmt.Errorf("unexpected output: key in cert")
-	}
-	return certPEM, keyPEM, nil
-}
-
-// GetCertificate fetches a TLS certificate for the TLS ClientHello in hi.
-//
-// It returns a cached certificate from disk if it's still valid.
-//
-// It's the right signature to use as the value of
-// tls.Config.GetCertificate.
-func GetCertificate(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
-	if hi == nil || hi.ServerName == "" {
-		return nil, errors.New("no SNI ServerName")
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-	defer cancel()
-
-	name := hi.ServerName
-	if !strings.Contains(name, ".") {
-		if v, ok := ExpandSNIName(ctx, name); ok {
-			name = v
-		}
-	}
-	certPEM, keyPEM, err := CertPair(ctx, name)
-	if err != nil {
-		return nil, err
-	}
-	cert, err := tls.X509KeyPair(certPEM, keyPEM)
-	if err != nil {
-		return nil, err
-	}
-	return &cert, nil
-}
-
-// ExpandSNIName expands bare label name into the the most likely actual TLS cert name.
-func ExpandSNIName(ctx context.Context, name string) (fqdn string, ok bool) {
-	st, err := StatusWithoutPeers(ctx)
-	if err != nil {
-		return "", false
-	}
-	for _, d := range st.CertDomains {
-		if len(d) > len(name)+1 && strings.HasPrefix(d, name) && d[len(name)] == '.' {
-			return d, true
-		}
-	}
-	return "", false
-}

cmd/addlicense/main.go

@@ -1,77 +0,0 @@
-// 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.
-
-// Program addlicense adds a license header to a file.
-// It is intended for use with 'go generate',
-// so it has a slightly weird usage.
-package main
-
-import (
-	"flag"
-	"fmt"
-	"os"
-	"os/exec"
-)
-
-var (
-	year = flag.Int("year", 0, "copyright year")
-	file = flag.String("file", "", "file to modify")
-)
-
-func usage() {
-	fmt.Fprintf(os.Stderr, `
-usage: addlicense -year YEAR -file FILE <subcommand args...>
-`[1:])
-
-	flag.PrintDefaults()
-	fmt.Fprintf(os.Stderr, `
-addlicense adds a Tailscale license to the beginning of file,
-using year as the copyright year.
-
-It is intended for use with 'go generate', so it also runs a subcommand,
-which presumably creates the file.
-
-Sample usage:
-
-addlicense -year 2021 -file pull_strings.go stringer -type=pull
-`[1:])
-	os.Exit(2)
-}
-
-func main() {
-	flag.Usage = usage
-	flag.Parse()
-	if len(flag.Args()) == 0 {
-		flag.Usage()
-	}
-	cmd := exec.Command(flag.Arg(0), flag.Args()[1:]...)
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	err := cmd.Run()
-	check(err)
-	b, err := os.ReadFile(*file)
-	check(err)
-	f, err := os.OpenFile(*file, os.O_TRUNC|os.O_WRONLY, 0644)
-	check(err)
-	_, err = fmt.Fprintf(f, license, *year)
-	check(err)
-	_, err = f.Write(b)
-	check(err)
-	err = f.Close()
-	check(err)
-}
-
-func check(err error) {
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
-	}
-}
-
-var license = `
-// Copyright (c) %d 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.
-
-`[1:]

cmd/cloner/cloner.go

@@ -246,9 +246,7 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, name string, typ *types
 					writef("\t\tdst.%s[k] = append([]%s{}, src.%s[k]...)", fname, n, fname)
 					writef("\t}")
 				} else if containsPointers(ft.Elem()) {
-					writef("\tfor k, v := range src.%s {", fname)
-					writef("\t\tdst.%s[k] = v.Clone()", fname)
-					writef("\t}")
+					writef("\t\t" + `panic("TODO map value pointers")`)
 				} else {
 					writef("\tfor k, v := range src.%s {", fname)
 					writef("\t\tdst.%s[k] = v", fname)

cmd/derper/derper.go

@@ -12,6 +12,8 @@ import (
 	"errors"
 	"expvar"
 	"flag"
+	"fmt"
+	"html"
 	"io"
 	"io/ioutil"
 	"log"
@@ -33,6 +35,7 @@ import (
 	"tailscale.com/tsweb"
 	"tailscale.com/types/key"
 	"tailscale.com/types/wgkey"
+	"tailscale.com/version"
 )
 
 var (
@@ -46,7 +49,6 @@ var (
 	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")
-	verifyClients = flag.Bool("verify-clients", false, "verify clients to this DERP server through a local tailscaled instance.")
 )
 
 type config struct {
@@ -58,12 +60,7 @@ func loadConfig() config {
 		return config{PrivateKey: mustNewKey()}
 	}
 	if *configPath == "" {
-		if os.Getuid() == 0 {
-			*configPath = "/var/lib/derper/derper.key"
-		} else {
-			log.Fatalf("derper: -c <config path> not specified")
-		}
-		log.Printf("no config path specified; using %s", *configPath)
+		log.Fatalf("derper: -c <config path> not specified")
 	}
 	b, err := ioutil.ReadFile(*configPath)
 	switch {
@@ -128,7 +125,6 @@ func main() {
 	letsEncrypt := tsweb.IsProd443(*addr)
 
 	s := derp.NewServer(key.Private(cfg.PrivateKey), log.Printf)
-	s.SetVerifyClient(*verifyClients)
 
 	if *meshPSKFile != "" {
 		b, err := ioutil.ReadFile(*meshPSKFile)
@@ -147,7 +143,8 @@ func main() {
 	}
 	expvar.Publish("derp", s.ExpVar())
 
-	mux := http.NewServeMux()
+	// 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)
@@ -167,18 +164,6 @@ func main() {
 			io.WriteString(w, "<p>Debug info at <a href='/debug/'>/debug/</a>.</p>\n")
 		}
 	}))
-	debug := tsweb.Debugger(mux)
-	debug.KV("TLS hostname", *hostname)
-	debug.KV("Mesh key", s.HasMeshKey())
-	debug.Handle("check", "Consistency check", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		err := s.ConsistencyCheck()
-		if err != nil {
-			http.Error(w, err.Error(), 500)
-		} else {
-			io.WriteString(w, "derp.Server ConsistencyCheck okay")
-		}
-	}))
-	debug.Handle("traffic", "Traffic check", http.HandlerFunc(s.ServeDebugTraffic))
 
 	if *runSTUN {
 		go serveSTUN()
@@ -232,6 +217,39 @@ func main() {
 	}
 }
 
+func debugHandler(s *derp.Server) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.RequestURI == "/debug/check" {
+			err := s.ConsistencyCheck()
+			if err != nil {
+				http.Error(w, err.Error(), 500)
+			} else {
+				io.WriteString(w, "derp.Server ConsistencyCheck okay")
+			}
+			return
+		}
+		f := func(format string, args ...interface{}) { fmt.Fprintf(w, format, args...) }
+		f(`<html><body>
+<h1>DERP debug</h1>
+<ul>
+`)
+		f("<li><b>Hostname:</b> %v</li>\n", html.EscapeString(*hostname))
+		f("<li><b>Uptime:</b> %v</li>\n", tsweb.Uptime())
+		f("<li><b>Mesh Key:</b> %v</li>\n", s.HasMeshKey())
+		f("<li><b>Version:</b> %v</li>\n", html.EscapeString(version.Long))
+
+		f(`<li><a href="/debug/vars">/debug/vars</a> (Go)</li>
+   <li><a href="/debug/varz">/debug/varz</a> (Prometheus)</li>
+   <li><a href="/debug/pprof/">/debug/pprof/</a></li>
+   <li><a href="/debug/pprof/goroutine?debug=1">/debug/pprof/goroutine</a> (collapsed)</li>
+   <li><a href="/debug/pprof/goroutine?debug=2">/debug/pprof/goroutine</a> (full)</li>
+   <li><a href="/debug/check">/debug/check</a> internal consistency check</li>
+<ul>
+</html>
+`)
+	})
+}
+
 func serveSTUN() {
 	pc, err := net.ListenPacket("udp", ":3478")
 	if err != nil {

cmd/derper/mesh.go

@@ -9,9 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
-	"net"
 	"strings"
-	"time"
 
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
@@ -41,34 +39,6 @@ func startMeshWithHost(s *derp.Server, host string) error {
 		return err
 	}
 	c.MeshKey = s.MeshKey()
-
-	// For meshed peers within a region, connect via VPC addresses.
-	c.SetURLDialer(func(ctx context.Context, network, addr string) (net.Conn, error) {
-		host, port, err := net.SplitHostPort(addr)
-		if err != nil {
-			return nil, err
-		}
-		var d net.Dialer
-		var r net.Resolver
-		if port == "443" && strings.HasSuffix(host, ".tailscale.com") {
-			base := strings.TrimSuffix(host, ".tailscale.com")
-			subCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
-			defer cancel()
-			vpcHost := base + "-vpc.tailscale.com"
-			ips, _ := r.LookupIP(subCtx, "ip", vpcHost)
-			if len(ips) > 0 {
-				vpcAddr := net.JoinHostPort(ips[0].String(), port)
-				c, err := d.DialContext(subCtx, network, vpcAddr)
-				if err == nil {
-					log.Printf("connected to %v (%v) instead of %v", vpcHost, ips[0], base)
-					return c, nil
-				}
-				log.Printf("failed to connect to %v (%v): %v; trying non-VPC route", vpcHost, ips[0], err)
-			}
-		}
-		return d.DialContext(ctx, network, addr)
-	})
-
 	add := func(k key.Public) { s.AddPacketForwarder(k, c) }
 	remove := func(k key.Public) { s.RemovePacketForwarder(k, c) }
 	go c.RunWatchConnectionLoop(context.Background(), s.PublicKey(), logf, add, remove)

cmd/derpprobe/derpprobe.go

@@ -1,354 +0,0 @@
-// 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 derpprobe binary probes derpers.
-package main // import "tailscale.com/cmd/derper/derpprobe"
-
-import (
-	"bytes"
-	"context"
-	crand "crypto/rand"
-	"encoding/json"
-	"flag"
-	"fmt"
-	"html"
-	"io"
-	"log"
-	"net/http"
-	"sort"
-	"sync"
-	"time"
-
-	"tailscale.com/derp"
-	"tailscale.com/derp/derphttp"
-	"tailscale.com/tailcfg"
-	"tailscale.com/types/key"
-)
-
-var (
-	derpMapURL = flag.String("derp-map", "https://login.tailscale.com/derpmap/default", "URL to DERP map (https:// or file://)")
-	listen     = flag.String("listen", ":8030", "HTTP listen address")
-)
-
-var (
-	mu            sync.Mutex
-	state         = map[nodePair]pairStatus{}
-	lastDERPMap   *tailcfg.DERPMap
-	lastDERPMapAt time.Time
-)
-
-func main() {
-	flag.Parse()
-	go probeLoop()
-	log.Fatal(http.ListenAndServe(*listen, http.HandlerFunc(serve)))
-}
-
-type overallStatus struct {
-	good, bad []string
-}
-
-func (st *overallStatus) addBadf(format string, a ...interface{}) {
-	st.bad = append(st.bad, fmt.Sprintf(format, a...))
-}
-
-func (st *overallStatus) addGoodf(format string, a ...interface{}) {
-	st.good = append(st.good, fmt.Sprintf(format, a...))
-}
-
-func getOverallStatus() (o overallStatus) {
-	mu.Lock()
-	defer mu.Unlock()
-	if lastDERPMap == nil {
-		o.addBadf("no DERP map")
-		return
-	}
-	now := time.Now()
-	if age := now.Sub(lastDERPMapAt); age > time.Minute {
-		o.addBadf("DERPMap hasn't been successfully refreshed in %v", age.Round(time.Second))
-	}
-	for _, reg := range sortedRegions(lastDERPMap) {
-		for _, from := range reg.Nodes {
-			for _, to := range reg.Nodes {
-				pair := nodePair{from.Name, to.Name}
-				st, ok := state[pair]
-				age := now.Sub(st.at).Round(time.Second)
-				switch {
-				case !ok:
-					o.addBadf("no state for %v", pair)
-				case st.err != nil:
-					o.addBadf("%v: %v", pair, st.err)
-				case age > 90*time.Second:
-					o.addBadf("%v: update is %v old", pair, age)
-				default:
-					o.addGoodf("%v: %v, %v ago", pair, st.latency.Round(time.Millisecond), age)
-				}
-			}
-		}
-	}
-	return
-}
-
-func serve(w http.ResponseWriter, r *http.Request) {
-	st := getOverallStatus()
-	summary := "All good"
-	if len(st.bad) > 0 {
-		w.WriteHeader(500)
-		summary = fmt.Sprintf("%d problems", len(st.bad))
-	}
-	io.WriteString(w, "<html><head><style>.bad { font-weight: bold; color: #700; }</style></head>\n")
-	fmt.Fprintf(w, "<body><h1>derp probe</h1>\n%s:<ul>", summary)
-	for _, s := range st.bad {
-		fmt.Fprintf(w, "<li class=bad>%s</li>\n", html.EscapeString(s))
-	}
-	for _, s := range st.good {
-		fmt.Fprintf(w, "<li>%s</li>\n", html.EscapeString(s))
-	}
-	io.WriteString(w, "</ul></body></html>\n")
-}
-
-func sortedRegions(dm *tailcfg.DERPMap) []*tailcfg.DERPRegion {
-	ret := make([]*tailcfg.DERPRegion, 0, len(dm.Regions))
-	for _, r := range dm.Regions {
-		ret = append(ret, r)
-	}
-	sort.Slice(ret, func(i, j int) bool { return ret[i].RegionID < ret[j].RegionID })
-	return ret
-}
-
-type nodePair struct {
-	from, to string // DERPNode.Name
-}
-
-func (p nodePair) String() string { return fmt.Sprintf("(%s→%s)", p.from, p.to) }
-
-type pairStatus struct {
-	err     error
-	latency time.Duration
-	at      time.Time
-}
-
-func setDERPMap(dm *tailcfg.DERPMap) {
-	mu.Lock()
-	defer mu.Unlock()
-	lastDERPMap = dm
-	lastDERPMapAt = time.Now()
-}
-
-func setState(p nodePair, latency time.Duration, err error) {
-	mu.Lock()
-	defer mu.Unlock()
-	st := pairStatus{
-		err:     err,
-		latency: latency,
-		at:      time.Now(),
-	}
-	state[p] = st
-	if err != nil {
-		log.Printf("%+v error: %v", p, err)
-	} else {
-		log.Printf("%+v: %v", p, latency.Round(time.Millisecond))
-	}
-}
-
-func probeLoop() {
-	ticker := time.NewTicker(15 * time.Second)
-	for {
-		err := probe()
-		if err != nil {
-			log.Printf("probe: %v", err)
-		}
-		<-ticker.C
-	}
-}
-
-func probe() error {
-	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
-	defer cancel()
-	dm, err := getDERPMap(ctx)
-	if err != nil {
-		return err
-	}
-
-	var wg sync.WaitGroup
-	wg.Add(len(dm.Regions))
-	for _, reg := range dm.Regions {
-		reg := reg
-		go func() {
-			defer wg.Done()
-			for _, from := range reg.Nodes {
-				for _, to := range reg.Nodes {
-					latency, err := probeNodePair(ctx, dm, from, to)
-					setState(nodePair{from.Name, to.Name}, latency, err)
-				}
-			}
-		}()
-	}
-
-	wg.Wait()
-	return ctx.Err()
-}
-
-func probeNodePair(ctx context.Context, dm *tailcfg.DERPMap, from, to *tailcfg.DERPNode) (latency time.Duration, err error) {
-	// The passed in context is a minute for the whole region. The
-	// idea is that each node pair in the region will be done
-	// serially and regularly in the future, reusing connections
-	// (at least in the happy path). For now they don't reuse
-	// connections and probe at most once every 15 seconds. We
-	// bound the duration of a single node pair within a region
-	// so one bad one can't starve others.
-	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
-	defer cancel()
-
-	fromc, err := newConn(ctx, dm, from)
-	if err != nil {
-		return 0, err
-	}
-	defer fromc.Close()
-	toc, err := newConn(ctx, dm, to)
-	if err != nil {
-		return 0, err
-	}
-	defer toc.Close()
-
-	// Wait a bit for from's node to hear about to existing on the
-	// other node in the region, in the case where the two nodes
-	// are different.
-	if from.Name != to.Name {
-		time.Sleep(100 * time.Millisecond) // pretty arbitrary
-	}
-
-	// Make a random packet
-	pkt := make([]byte, 8)
-	crand.Read(pkt)
-
-	t0 := time.Now()
-
-	// Send the random packet.
-	sendc := make(chan error, 1)
-	go func() {
-		sendc <- fromc.Send(toc.SelfPublicKey(), pkt)
-	}()
-	select {
-	case <-ctx.Done():
-		return 0, fmt.Errorf("timeout sending via %q: %w", from.Name, ctx.Err())
-	case err := <-sendc:
-		if err != nil {
-			return 0, fmt.Errorf("error sending via %q: %w", from.Name, err)
-		}
-	}
-
-	// Receive the random packet.
-	recvc := make(chan interface{}, 1) // either derp.ReceivedPacket or error
-	go func() {
-		for {
-			m, err := toc.Recv()
-			if err != nil {
-				recvc <- err
-				return
-			}
-			switch v := m.(type) {
-			case derp.ReceivedPacket:
-				recvc <- v
-			default:
-				log.Printf("%v: ignoring Recv frame type %T", to.Name, v)
-				// Loop.
-			}
-		}
-	}()
-	select {
-	case <-ctx.Done():
-		return 0, fmt.Errorf("timeout receiving from %q: %w", to.Name, ctx.Err())
-	case v := <-recvc:
-		if err, ok := v.(error); ok {
-			return 0, fmt.Errorf("error receiving from %q: %w", to.Name, err)
-		}
-		p := v.(derp.ReceivedPacket)
-		if p.Source != fromc.SelfPublicKey() {
-			return 0, fmt.Errorf("got data packet from unexpected source, %v", p.Source)
-		}
-		if !bytes.Equal(p.Data, pkt) {
-			return 0, fmt.Errorf("unexpected data packet %q", p.Data)
-		}
-	}
-	return time.Since(t0), nil
-}
-
-func newConn(ctx context.Context, dm *tailcfg.DERPMap, n *tailcfg.DERPNode) (*derphttp.Client, error) {
-	priv := key.NewPrivate()
-	dc := derphttp.NewRegionClient(priv, log.Printf, func() *tailcfg.DERPRegion {
-		rid := n.RegionID
-		return &tailcfg.DERPRegion{
-			RegionID:   rid,
-			RegionCode: fmt.Sprintf("%s-%s", dm.Regions[rid].RegionCode, n.Name),
-			RegionName: dm.Regions[rid].RegionName,
-			Nodes:      []*tailcfg.DERPNode{n},
-		}
-	})
-	dc.IsProber = true
-	err := dc.Connect(ctx)
-	if err != nil {
-		return nil, err
-	}
-	errc := make(chan error, 1)
-	go func() {
-		m, err := dc.Recv()
-		if err != nil {
-			errc <- err
-			return
-		}
-		switch m.(type) {
-		case derp.ServerInfoMessage:
-			errc <- nil
-		default:
-			errc <- fmt.Errorf("unexpected first message type %T", errc)
-		}
-	}()
-	select {
-	case err := <-errc:
-		if err != nil {
-			go dc.Close()
-			return nil, err
-		}
-	case <-ctx.Done():
-		go dc.Close()
-		return nil, fmt.Errorf("timeout waiting for ServerInfoMessage: %w", ctx.Err())
-	}
-	return dc, nil
-}
-
-var httpOrFileClient = &http.Client{Transport: httpOrFileTransport()}
-
-func httpOrFileTransport() http.RoundTripper {
-	tr := http.DefaultTransport.(*http.Transport).Clone()
-	tr.RegisterProtocol("file", http.NewFileTransport(http.Dir("/")))
-	return tr
-}
-
-func getDERPMap(ctx context.Context) (*tailcfg.DERPMap, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", *derpMapURL, nil)
-	if err != nil {
-		return nil, err
-	}
-	res, err := httpOrFileClient.Do(req)
-	if err != nil {
-		mu.Lock()
-		defer mu.Unlock()
-		if lastDERPMap != nil && time.Since(lastDERPMapAt) < 10*time.Minute {
-			// Assume that control is restarting and use
-			// the same one for a bit.
-			return lastDERPMap, nil
-		}
-		return nil, err
-	}
-	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		return nil, fmt.Errorf("fetching %s: %s", *derpMapURL, res.Status)
-	}
-	dm := new(tailcfg.DERPMap)
-	if err := json.NewDecoder(res.Body).Decode(dm); err != nil {
-		return nil, fmt.Errorf("decoding %s JSON: %v", *derpMapURL, err)
-	}
-	setDERPMap(dm)
-	return dm, nil
-}

cmd/microproxy/microproxy.go

@@ -0,0 +1,189 @@
+// 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.
+
+// microproxy proxies incoming HTTPS connections to another
+// destination. Instead of managing its own TLS certificates, it
+// borrows issued certificates and keys from an autocert directory.
+package main
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"tailscale.com/logpolicy"
+	"tailscale.com/tsweb"
+)
+
+var (
+	addr          = flag.String("addr", ":4430", "server address")
+	certdir       = flag.String("certdir", "", "directory to borrow LetsEncrypt certificates from")
+	hostname      = flag.String("hostname", "", "hostname to serve")
+	logCollection = flag.String("logcollection", "", "If non-empty, logtail collection to log to")
+	nodeExporter  = flag.String("node-exporter", "http://localhost:9100", "URL of the local prometheus node exporter")
+	goVarsURL     = flag.String("go-vars-url", "http://localhost:8383/debug/vars", "URL of a local Go server's /debug/vars endpoint")
+	insecure      = flag.Bool("insecure", false, "serve over http, for development")
+)
+
+func main() {
+	flag.Parse()
+
+	if *logCollection != "" {
+		logpolicy.New(*logCollection)
+	}
+
+	ne, err := url.Parse(*nodeExporter)
+	if err != nil {
+		log.Fatalf("Couldn't parse URL %q: %v", *nodeExporter, err)
+	}
+	proxy := httputil.NewSingleHostReverseProxy(ne)
+	proxy.FlushInterval = time.Second
+
+	if _, err = url.Parse(*goVarsURL); err != nil {
+		log.Fatalf("Couldn't parse URL %q: %v", *goVarsURL, err)
+	}
+
+	mux := tsweb.NewMux(http.HandlerFunc(debugHandler))
+	mux.Handle("/metrics", tsweb.Protected(proxy))
+	mux.Handle("/varz", tsweb.Protected(tsweb.StdHandler(&goVarsHandler{*goVarsURL}, log.Printf)))
+
+	ch := &certHolder{
+		hostname: *hostname,
+		path:     filepath.Join(*certdir, *hostname),
+	}
+
+	httpsrv := &http.Server{
+		Addr:    *addr,
+		Handler: mux,
+	}
+
+	if !*insecure {
+		httpsrv.TLSConfig = &tls.Config{GetCertificate: ch.GetCertificate}
+		err = httpsrv.ListenAndServeTLS("", "")
+	} else {
+		err = httpsrv.ListenAndServe()
+	}
+	if err != nil && err != http.ErrServerClosed {
+		log.Fatal(err)
+	}
+}
+
+type goVarsHandler struct {
+	url string
+}
+
+func promPrint(w io.Writer, prefix string, obj map[string]interface{}) {
+	for k, i := range obj {
+		if prefix != "" {
+			k = prefix + "_" + k
+		}
+		switch v := i.(type) {
+		case map[string]interface{}:
+			promPrint(w, k, v)
+		case float64:
+			const saveConfigReject = "control_save_config_rejected_"
+			const saveConfig = "control_save_config_"
+			switch {
+			case strings.HasPrefix(k, saveConfigReject):
+				fmt.Fprintf(w, "control_save_config_rejected{reason=%q} %f\n", k[len(saveConfigReject):], v)
+			case strings.HasPrefix(k, saveConfig):
+				fmt.Fprintf(w, "control_save_config{reason=%q} %f\n", k[len(saveConfig):], v)
+			default:
+				fmt.Fprintf(w, "%s %f\n", k, v)
+			}
+		default:
+			fmt.Fprintf(w, "# Skipping key %q, unhandled type %T\n", k, v)
+		}
+	}
+}
+
+func (h *goVarsHandler) ServeHTTPReturn(w http.ResponseWriter, r *http.Request) error {
+	resp, err := http.Get(h.url)
+	if err != nil {
+		return tsweb.Error(http.StatusInternalServerError, "fetch failed", err)
+	}
+	defer resp.Body.Close()
+	var mon map[string]interface{}
+	if err := json.NewDecoder(resp.Body).Decode(&mon); err != nil {
+		return tsweb.Error(http.StatusInternalServerError, "fetch failed", err)
+	}
+
+	w.WriteHeader(http.StatusOK)
+	promPrint(w, "", mon)
+	return nil
+}
+
+// certHolder loads and caches a TLS certificate from disk, reloading
+// it every hour.
+type certHolder struct {
+	hostname string // only hostname allowed in SNI
+	path     string // path of certificate+key combined PEM file
+
+	mu     sync.Mutex
+	cert   *tls.Certificate // cached parsed cert+key
+	loaded time.Time
+}
+
+func (c *certHolder) GetCertificate(ch *tls.ClientHelloInfo) (*tls.Certificate, error) {
+	if ch.ServerName != c.hostname {
+		return nil, fmt.Errorf("wrong client SNI %q", ch.ServerName)
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if time.Since(c.loaded) > time.Hour {
+		if err := c.loadLocked(); err != nil {
+			log.Printf("Reloading cert %q: %v", c.path, err)
+			// continue anyway, we might be able to serve off the stale cert.
+		}
+	}
+	return c.cert, nil
+}
+
+// load reloads the TLS certificate and key from disk. Caller must
+// hold mu.
+func (c *certHolder) loadLocked() error {
+	bs, err := ioutil.ReadFile(c.path)
+	if err != nil {
+		return fmt.Errorf("reading %q: %v", c.path, err)
+	}
+	cert, err := tls.X509KeyPair(bs, bs)
+	if err != nil {
+		return fmt.Errorf("parsing %q: %v", c.path, err)
+	}
+
+	c.cert = &cert
+	c.loaded = time.Now()
+	return nil
+}
+
+// debugHandler serves a page with links to tsweb-managed debug URLs
+// at /debug/.
+func debugHandler(w http.ResponseWriter, r *http.Request) {
+	f := func(format string, args ...interface{}) { fmt.Fprintf(w, format, args...) }
+	f(`<html><body>
+<h1>microproxy debug</h1>
+<ul>
+`)
+	f("<li><b>Hostname:</b> %v</li>\n", *hostname)
+	f("<li><b>Uptime:</b> %v</li>\n", tsweb.Uptime())
+	f(`<li><a href="/debug/vars">/debug/vars</a> (Go)</li>
+   <li><a href="/debug/varz">/debug/varz</a> (Prometheus)</li>
+   <li><a href="/debug/pprof/">/debug/pprof/</a></li>
+   <li><a href="/debug/pprof/goroutine?debug=1">/debug/pprof/goroutine</a> (collapsed)</li>
+   <li><a href="/debug/pprof/goroutine?debug=2">/debug/pprof/goroutine</a> (full)</li>
+<ul>
+</html>
+`)
+}

cmd/mkpkg/main.go

@@ -21,9 +21,6 @@ import (
 // into a map of filePathOnDisk -> filePathInPackage.
 func parseFiles(s string) (map[string]string, error) {
 	ret := map[string]string{}
-	if len(s) == 0 {
-		return ret, nil
-	}
 	for _, f := range strings.Split(s, ",") {
 		fs := strings.Split(f, ":")
 		if len(fs) != 2 {

cmd/speedtest/speedtest.go

@@ -1,121 +0,0 @@
-// 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.
-
-// Program speedtest provides the speedtest command. The reason to keep it separate from
-// the normal tailscale cli is because it is not yet ready to go in the tailscale binary.
-// It will be included in the tailscale cli after it has been added to tailscaled.
-
-// Example usage for client command: go run cmd/speedtest -host 127.0.0.1:20333 -t 5s
-// This will connect to the server on 127.0.0.1:20333 and start a 5 second download speedtest.
-// Example usage for server command: go run cmd/speedtest -s -host :20333
-// This will start a speedtest server on port 20333.
-package main
-
-import (
-	"context"
-	"errors"
-	"flag"
-	"fmt"
-	"net"
-	"os"
-	"strconv"
-	"text/tabwriter"
-	"time"
-
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/net/speedtest"
-)
-
-// Runs the speedtest command as a commandline program
-func main() {
-	args := os.Args[1:]
-	if err := speedtestCmd.Parse(args); err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
-		os.Exit(1)
-	}
-
-	err := speedtestCmd.Run(context.Background())
-	if errors.Is(err, flag.ErrHelp) {
-		fmt.Fprintln(os.Stderr, speedtestCmd.ShortUsage)
-		os.Exit(2)
-	}
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
-		os.Exit(1)
-	}
-}
-
-// speedtestCmd is the root command. It runs either the server or client depending on the
-// flags passed to it.
-var speedtestCmd = &ffcli.Command{
-	Name:       "speedtest",
-	ShortUsage: "speedtest [-host <host:port>] [-s] [-r] [-t <test duration>]",
-	ShortHelp:  "Run a speed test",
-	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("speedtest", flag.ExitOnError)
-		fs.StringVar(&speedtestArgs.host, "host", ":20333", "host:port pair to connect to or listen on")
-		fs.DurationVar(&speedtestArgs.testDuration, "t", speedtest.DefaultDuration, "duration of the speed test")
-		fs.BoolVar(&speedtestArgs.runServer, "s", false, "run a speedtest server")
-		fs.BoolVar(&speedtestArgs.reverse, "r", false, "run in reverse mode (server sends, client receives)")
-		return fs
-	})(),
-	Exec: runSpeedtest,
-}
-
-var speedtestArgs struct {
-	host         string
-	testDuration time.Duration
-	runServer    bool
-	reverse      bool
-}
-
-func runSpeedtest(ctx context.Context, args []string) error {
-
-	if _, _, err := net.SplitHostPort(speedtestArgs.host); err != nil {
-		var addrErr *net.AddrError
-		if errors.As(err, &addrErr) && addrErr.Err == "missing port in address" {
-			// if no port is provided, append the default port
-			speedtestArgs.host = net.JoinHostPort(speedtestArgs.host, strconv.Itoa(speedtest.DefaultPort))
-		}
-	}
-
-	if speedtestArgs.runServer {
-		listener, err := net.Listen("tcp", speedtestArgs.host)
-		if err != nil {
-			return err
-		}
-
-		fmt.Printf("listening on %v\n", listener.Addr())
-
-		return speedtest.Serve(listener)
-	}
-
-	// Ensure the duration is within the allowed range
-	if speedtestArgs.testDuration < speedtest.MinDuration || speedtestArgs.testDuration > speedtest.MaxDuration {
-		return fmt.Errorf("test duration must be within %v and %v", speedtest.MinDuration, speedtest.MaxDuration)
-	}
-
-	dir := speedtest.Download
-	if speedtestArgs.reverse {
-		dir = speedtest.Upload
-	}
-
-	fmt.Printf("Starting a %s test with %s\n", dir, speedtestArgs.host)
-	results, err := speedtest.RunClient(dir, speedtestArgs.testDuration, speedtestArgs.host)
-	if err != nil {
-		return err
-	}
-
-	w := tabwriter.NewWriter(os.Stdout, 12, 0, 0, ' ', tabwriter.TabIndent)
-	fmt.Println("Results:")
-	fmt.Fprintln(w, "Interval\t\tTransfer\t\tBandwidth\t\t")
-	for _, r := range results {
-		if r.Total {
-			fmt.Fprintln(w, "-------------------------------------------------------------------------")
-		}
-		fmt.Fprintf(w, "%.2f-%.2f\tsec\t%.4f\tMBits\t%.4f\tMbits/sec\t\n", r.IntervalStart.Seconds(), r.IntervalEnd.Seconds(), r.MegaBits(), r.MBitsPerSecond())
-	}
-	w.Flush()
-	return nil
-}

cmd/tailscale/cli/auth-redirect.html

@@ -1,57 +0,0 @@
-<html>
-<head>
-	<title>Redirecting...</title>
-	<style>
-		html,
-		body {
-			height: 100%;
-		}
-
-		html {
-			background-color: rgb(249, 247, 246);
-			font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
-			line-height: 1.5;
-			-webkit-text-size-adjust: 100%;
-			-webkit-font-smoothing: antialiased;
-			-moz-osx-font-smoothing: grayscale;
-		}
-
-		body {
-			display: flex;
-			flex-direction: column;
-			align-items: center;
-			justify-content: center;
-		}
-
-		.spinner {
-			margin-bottom: 2rem;
-			border: 4px rgba(112, 110, 109, 0.5) solid;
-			border-left-color: transparent;
-			border-radius: 9999px;
-			width: 4rem;
-			height: 4rem;
-			-webkit-animation: spin 700ms linear infinite;
-      animation: spin 800ms linear infinite;
-		}
-
-		.label {
-			color: rgb(112, 110, 109);
-			padding-left: 0.4rem;
-		}
-
-		@-webkit-keyframes spin {
-			to {
-				transform: rotate(360deg);
-			}
-		}
-
-		@keyframes spin {
-			to {
-				transform: rotate(360deg);
-			}
-		}
-	</style>
-</head> <body>
-	<div class="spinner"></div>
-	<div class="label">Redirecting...</div>
-</body>

cmd/tailscale/cli/cert.go

@@ -1,107 +0,0 @@
-// 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"
-	"crypto/tls"
-	"flag"
-	"fmt"
-	"log"
-	"net/http"
-	"os"
-	"strings"
-
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/atomicfile"
-	"tailscale.com/client/tailscale"
-)
-
-var certCmd = &ffcli.Command{
-	Name:       "cert",
-	Exec:       runCert,
-	ShortHelp:  "get TLS certs",
-	ShortUsage: "cert [flags] <domain>",
-	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("cert", flag.ExitOnError)
-		fs.StringVar(&certArgs.certFile, "cert-file", "", "output cert file; defaults to DOMAIN.crt")
-		fs.StringVar(&certArgs.keyFile, "key-file", "", "output cert file; defaults to DOMAIN.key")
-		fs.BoolVar(&certArgs.serve, "serve-demo", false, "if true, serve on port :443 using the cert as a demo, instead of writing out the files to disk")
-		return fs
-	})(),
-}
-
-var certArgs struct {
-	certFile string
-	keyFile  string
-	serve    bool
-}
-
-func runCert(ctx context.Context, args []string) error {
-	if certArgs.serve {
-		s := &http.Server{
-			TLSConfig: &tls.Config{
-				GetCertificate: tailscale.GetCertificate,
-			},
-			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				if r.TLS != nil && !strings.Contains(r.Host, ".") && r.Method == "GET" {
-					if v, ok := tailscale.ExpandSNIName(r.Context(), r.Host); ok {
-						http.Redirect(w, r, "https://"+v+r.URL.Path, http.StatusTemporaryRedirect)
-						return
-					}
-				}
-				fmt.Fprintf(w, "<h1>Hello from Tailscale</h1>It works.")
-			}),
-		}
-		log.Printf("running TLS server on :443 ...")
-		return s.ListenAndServeTLS("", "")
-	}
-
-	if len(args) != 1 {
-		return fmt.Errorf("Usage: tailscale cert [flags] <domain>")
-	}
-	domain := args[0]
-
-	if certArgs.certFile == "" {
-		certArgs.certFile = domain + ".crt"
-	}
-	if certArgs.keyFile == "" {
-		certArgs.keyFile = domain + ".key"
-	}
-	certPEM, keyPEM, err := tailscale.CertPair(ctx, domain)
-	if err != nil {
-		return err
-	}
-	certChanged, err := writeIfChanged(certArgs.certFile, certPEM, 0644)
-	if err != nil {
-		return err
-	}
-	if certChanged {
-		fmt.Printf("Wrote public cert to %v\n", certArgs.certFile)
-	} else {
-		fmt.Printf("Public cert unchanged at %v\n", certArgs.certFile)
-	}
-	keyChanged, err := writeIfChanged(certArgs.keyFile, keyPEM, 0600)
-	if err != nil {
-		return err
-	}
-	if keyChanged {
-		fmt.Printf("Wrote private key to %v\n", certArgs.keyFile)
-	} else {
-		fmt.Printf("Private key unchanged at %v\n", certArgs.keyFile)
-	}
-	return nil
-}
-
-func writeIfChanged(filename string, contents []byte, mode os.FileMode) (changed bool, err error) {
-	if old, err := os.ReadFile(filename); err == nil && bytes.Equal(contents, old) {
-		return false, nil
-	}
-	if err := atomicfile.WriteFile(filename, contents, mode); err != nil {
-		return false, err
-	}
-	return true, nil
-}

cmd/tailscale/cli/diag.go

@@ -1,56 +0,0 @@
-// 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.
-
-//go:build linux || windows || darwin
-// +build linux windows darwin
-
-package cli
-
-import (
-	"fmt"
-	"path/filepath"
-	"runtime"
-	"strings"
-
-	ps "github.com/mitchellh/go-ps"
-)
-
-// fixTailscaledConnectError is called when the local tailscaled has
-// been determined unreachable due to the provided origErr value. It
-// returns either the same error or a better one to help the user
-// understand why tailscaled isn't running for their platform.
-func fixTailscaledConnectError(origErr error) error {
-	procs, err := ps.Processes()
-	if err != nil {
-		return fmt.Errorf("failed to connect to local Tailscaled process and failed to enumerate processes while looking for it")
-	}
-	found := false
-	for _, proc := range procs {
-		base := filepath.Base(proc.Executable())
-		if base == "tailscaled" {
-			found = true
-			break
-		}
-		if runtime.GOOS == "darwin" && base == "IPNExtension" {
-			found = true
-			break
-		}
-		if runtime.GOOS == "windows" && strings.EqualFold(base, "tailscaled.exe") {
-			found = true
-			break
-		}
-	}
-	if !found {
-		switch runtime.GOOS {
-		case "windows":
-			return fmt.Errorf("failed to connect to local tailscaled process; is the Tailscale service running?")
-		case "darwin":
-			return fmt.Errorf("failed to connect to local Tailscale service; is Tailscale running?")
-		case "linux":
-			return fmt.Errorf("failed to connect to local tailscaled; it doesn't appear to be running (sudo systemctl start tailscaled ?)")
-		}
-		return fmt.Errorf("failed to connect to local tailscaled process; it doesn't appear to be running")
-	}
-	return fmt.Errorf("failed to connect to local tailscaled (which appears to be running). Got error: %w", origErr)
-}

cmd/tailscale/cli/diag_other.go

@@ -1,17 +0,0 @@
-// 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.
-
-//go:build !linux && !windows && !darwin
-// +build !linux,!windows,!darwin
-
-package cli
-
-import "fmt"
-
-// The github.com/mitchellh/go-ps package doesn't work on all platforms,
-// so just don't diagnose connect failures.
-
-func fixTailscaledConnectError(origErr error) error {
-	return fmt.Errorf("failed to connect to local tailscaled process (is it running?); got: %w", origErr)
-}

cmd/tailscale/cli/web_test.go

@@ -1,44 +0,0 @@
-// 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 "testing"
-
-func TestUrlOfListenAddr(t *testing.T) {
-	tests := []struct {
-		name     string
-		in, want string
-	}{
-		{
-			name: "TestLocalhost",
-			in:   "localhost:8088",
-			want: "http://localhost:8088",
-		},
-		{
-			name: "TestNoHost",
-			in:   ":8088",
-			want: "http://127.0.0.1:8088",
-		},
-		{
-			name: "TestExplicitHost",
-			in:   "127.0.0.2:8088",
-			want: "http://127.0.0.2:8088",
-		},
-		{
-			name: "TestIPv6",
-			in:   "[::1]:8088",
-			want: "http://[::1]:8088",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			url := urlOfListenAddr(tt.in)
-			if url != tt.want {
-				t.Errorf("expected url: %q, got: %q", tt.want, url)
-			}
-		})
-	}
-}

cmd/tailscale/depaware.txt

@@ -1,18 +1,10 @@
 tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/depaware)
 
-   W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate+
-   W    github.com/alexbrainman/sspi/internal/common                 from github.com/alexbrainman/sspi/negotiate
+   W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate
    W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
         github.com/kballard/go-shellquote                            from tailscale.com/cmd/tailscale/cli
-     💣 github.com/mitchellh/go-ps                                   from tailscale.com/cmd/tailscale/cli
         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/goupnp                                  from github.com/tailscale/goupnp/dcps/internetgateway2+
-        github.com/tailscale/goupnp/dcps/internetgateway2            from tailscale.com/net/portmapper
-        github.com/tailscale/goupnp/httpu                            from github.com/tailscale/goupnp+
-        github.com/tailscale/goupnp/scpd                             from github.com/tailscale/goupnp
-        github.com/tailscale/goupnp/soap                             from github.com/tailscale/goupnp+
-        github.com/tailscale/goupnp/ssdp                             from github.com/tailscale/goupnp
         github.com/tcnksm/go-httpstat                                from tailscale.com/net/netcheck
         github.com/toqueteos/webbrowser                              from tailscale.com/cmd/tailscale/cli
      💣 go4.org/intern                                               from inet.af/netaddr
@@ -20,15 +12,15 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         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+
-        tailscale.com/atomicfile                                     from tailscale.com/ipn+
-        tailscale.com/client/tailscale                               from tailscale.com/cmd/tailscale/cli+
+        rsc.io/goversion/version                                     from tailscale.com/version
+        tailscale.com/atomicfile                                     from tailscale.com/ipn
+        tailscale.com/client/tailscale                               from tailscale.com/cmd/tailscale/cli
         tailscale.com/client/tailscale/apitype                       from tailscale.com/client/tailscale+
         tailscale.com/cmd/tailscale/cli                              from tailscale.com/cmd/tailscale
-        tailscale.com/control/controlknobs                           from tailscale.com/net/portmapper
         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/hostinfo                                       from tailscale.com/net/interfaces
         tailscale.com/ipn                                            from tailscale.com/cmd/tailscale/cli+
         tailscale.com/ipn/ipnstate                                   from tailscale.com/cmd/tailscale/cli+
         tailscale.com/metrics                                        from tailscale.com/derp
@@ -45,29 +37,25 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
      💣 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/syncs                                          from tailscale.com/net/interfaces+
         tailscale.com/tailcfg                                        from tailscale.com/cmd/tailscale/cli+
    W    tailscale.com/tsconst                                        from tailscale.com/net/interfaces
-     💣 tailscale.com/tstime/mono                                    from tailscale.com/tstime/rate
-        tailscale.com/tstime/rate                                    from tailscale.com/wgengine/filter
-        tailscale.com/types/dnstype                                  from tailscale.com/tailcfg
         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/netmap                                   from tailscale.com/ipn
         tailscale.com/types/opt                                      from tailscale.com/net/netcheck+
-        tailscale.com/types/pad32                                    from tailscale.com/derp
         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
-        tailscale.com/util/groupmember                               from tailscale.com/cmd/tailscale/cli
-        tailscale.com/util/lineread                                  from tailscale.com/net/interfaces+
+   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/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/chacha20                                 from golang.org/x/crypto/chacha20poly1305
@@ -87,7 +75,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         golang.org/x/net/idna                                        from golang.org/x/net/http/httpguts+
         golang.org/x/net/proxy                                       from tailscale.com/net/netns
    D    golang.org/x/net/route                                       from net+
-        golang.org/x/sync/errgroup                                   from tailscale.com/derp+
+        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 tailscale.com/net/netns+
@@ -100,8 +88,9 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         golang.org/x/time/rate                                       from tailscale.com/cmd/tailscale/cli+
         bufio                                                        from compress/flate+
         bytes                                                        from bufio+
-        compress/flate                                               from compress/gzip
+        compress/flate                                               from compress/gzip+
         compress/gzip                                                from net/http
+        compress/zlib                                                from debug/elf+
         container/list                                               from crypto/tls+
         context                                                      from crypto/tls+
         crypto                                                       from crypto/ecdsa+
@@ -124,20 +113,24 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         crypto/tls                                                   from github.com/tcnksm/go-httpstat+
         crypto/x509                                                  from crypto/tls+
         crypto/x509/pkix                                             from crypto/x509+
+        debug/dwarf                                                  from debug/elf+
+        debug/elf                                                    from rsc.io/goversion/version
+        debug/macho                                                  from rsc.io/goversion/version
+        debug/pe                                                     from rsc.io/goversion/version
         embed                                                        from tailscale.com/cmd/tailscale/cli
-        encoding                                                     from encoding/json+
+        encoding                                                     from encoding/json
         encoding/asn1                                                from crypto/x509+
         encoding/base64                                              from encoding/json+
         encoding/binary                                              from compress/gzip+
         encoding/hex                                                 from crypto/x509+
         encoding/json                                                from expvar+
         encoding/pem                                                 from crypto/tls+
-        encoding/xml                                                 from tailscale.com/cmd/tailscale/cli+
         errors                                                       from bufio+
         expvar                                                       from tailscale.com/derp+
         flag                                                         from github.com/peterbourgon/ff/v2+
         fmt                                                          from compress/flate+
-        hash                                                         from crypto+
+        hash                                                         from compress/zlib+
+        hash/adler32                                                 from compress/zlib
         hash/crc32                                                   from compress/gzip+
         hash/maphash                                                 from go4.org/mem
         html                                                         from tailscale.com/ipn/ipnstate+
@@ -163,11 +156,10 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         os                                                           from crypto/rand+
         os/exec                                                      from github.com/toqueteos/webbrowser+
         os/signal                                                    from tailscale.com/cmd/tailscale/cli
-        os/user                                                      from tailscale.com/util/groupmember
-        path                                                         from html/template+
+        path                                                         from debug/dwarf+
         path/filepath                                                from crypto/x509+
         reflect                                                      from crypto/x509+
-        regexp                                                       from github.com/tailscale/goupnp/httpu+
+        regexp                                                       from rsc.io/goversion/version+
         regexp/syntax                                                from regexp
         runtime/debug                                                from golang.org/x/sync/singleflight
         sort                                                         from compress/flate+

cmd/tailscaled/cli/cli.go

@@ -107,7 +107,6 @@ change in the future.
 			webCmd,
 			fileCmd,
 			bugReportCmd,
-			certCmd,
 		},
 		FlagSet:   rootfs,
 		Exec:      func(context.Context, []string) error { return flag.ErrHelp },

cmd/tailscaled/cli/cli_test.go

@@ -13,11 +13,9 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/google/go-cmp/cmp"
 	"inet.af/netaddr"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
-	"tailscale.com/types/persist"
 	"tailscale.com/types/preftype"
 )
 
@@ -404,28 +402,6 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 			},
 			want: accidentalUpPrefix + " --hostname=foo --exit-node=100.64.5.7",
 		},
-		{
-			name:  "ignore_login_server_synonym",
-			flags: []string{"--login-server=https://controlplane.tailscale.com"},
-			curPrefs: &ipn.Prefs{
-				ControlURL:       "https://login.tailscale.com",
-				AllowSingleHosts: true,
-				CorpDNS:          true,
-				NetfilterMode:    preftype.NetfilterOn,
-			},
-			want: "", // not an error
-		},
-		{
-			name:  "ignore_login_server_synonym_on_other_change",
-			flags: []string{"--netfilter-mode=off"},
-			curPrefs: &ipn.Prefs{
-				ControlURL:       "https://login.tailscale.com",
-				AllowSingleHosts: true,
-				CorpDNS:          false,
-				NetfilterMode:    preftype.NetfilterOn,
-			},
-			want: accidentalUpPrefix + " --netfilter-mode=off --accept-dns=false",
-		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -442,9 +418,8 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 			}
 			applyImplicitPrefs(newPrefs, tt.curPrefs, tt.curUser)
 			var got string
-			if err := checkForAccidentalSettingReverts(newPrefs, tt.curPrefs, upCheckEnv{
+			if err := checkForAccidentalSettingReverts(flagSet, tt.curPrefs, newPrefs, upCheckEnv{
 				goos:          goos,
-				flagSet:       flagSet,
 				curExitNodeIP: tt.curExitNodeIP,
 			}); err != nil {
 				got = err.Error()
@@ -691,108 +666,3 @@ func TestFlagAppliesToOS(t *testing.T) {
 		})
 	}
 }
-
-func TestUpdatePrefs(t *testing.T) {
-	tests := []struct {
-		name     string
-		flags    []string // argv to be parsed into env.flagSet and env.upArgs
-		curPrefs *ipn.Prefs
-		env      upCheckEnv // empty goos means "linux"
-
-		wantSimpleUp   bool
-		wantJustEditMP *ipn.MaskedPrefs
-		wantErrSubtr   string
-	}{
-		{
-			name:  "bare_up_means_up",
-			flags: []string{},
-			curPrefs: &ipn.Prefs{
-				ControlURL:  ipn.DefaultControlURL,
-				WantRunning: false,
-				Hostname:    "foo",
-			},
-		},
-		{
-			name:  "just_up",
-			flags: []string{},
-			curPrefs: &ipn.Prefs{
-				ControlURL: ipn.DefaultControlURL,
-				Persist:    &persist.Persist{LoginName: "crawshaw.github"},
-			},
-			env: upCheckEnv{
-				backendState: "Stopped",
-			},
-			wantSimpleUp: true,
-		},
-		{
-			name:  "just_edit",
-			flags: []string{},
-			curPrefs: &ipn.Prefs{
-				ControlURL: ipn.DefaultControlURL,
-				Persist:    &persist.Persist{LoginName: "crawshaw.github"},
-			},
-			env:            upCheckEnv{backendState: "Running"},
-			wantSimpleUp:   true,
-			wantJustEditMP: &ipn.MaskedPrefs{WantRunningSet: true},
-		},
-		{
-			name:  "control_synonym",
-			flags: []string{},
-			curPrefs: &ipn.Prefs{
-				ControlURL: "https://login.tailscale.com",
-				Persist:    &persist.Persist{LoginName: "crawshaw.github"},
-			},
-			env:            upCheckEnv{backendState: "Running"},
-			wantSimpleUp:   true,
-			wantJustEditMP: &ipn.MaskedPrefs{WantRunningSet: true},
-		},
-		{
-			name:  "change_login_server",
-			flags: []string{"--login-server=https://localhost:1000"},
-			curPrefs: &ipn.Prefs{
-				ControlURL:       "https://login.tailscale.com",
-				Persist:          &persist.Persist{LoginName: "crawshaw.github"},
-				AllowSingleHosts: true,
-				CorpDNS:          true,
-				NetfilterMode:    preftype.NetfilterOn,
-			},
-			env:            upCheckEnv{backendState: "Running"},
-			wantSimpleUp:   true,
-			wantJustEditMP: &ipn.MaskedPrefs{WantRunningSet: true},
-			wantErrSubtr:   "can't change --login-server without --force-reauth",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if tt.env.goos == "" {
-				tt.env.goos = "linux"
-			}
-			tt.env.flagSet = newUpFlagSet(tt.env.goos, &tt.env.upArgs)
-			tt.env.flagSet.Parse(tt.flags)
-
-			newPrefs, err := prefsFromUpArgs(tt.env.upArgs, t.Logf, new(ipnstate.Status), tt.env.goos)
-			if err != nil {
-				t.Fatal(err)
-			}
-			simpleUp, justEditMP, err := updatePrefs(newPrefs, tt.curPrefs, tt.env)
-			if err != nil {
-				if tt.wantErrSubtr != "" {
-					if !strings.Contains(err.Error(), tt.wantErrSubtr) {
-						t.Fatalf("want error %q, got: %v", tt.wantErrSubtr, err)
-					}
-					return
-				}
-				t.Fatal(err)
-			}
-			if simpleUp != tt.wantSimpleUp {
-				t.Fatalf("simpleUp=%v, want %v", simpleUp, tt.wantSimpleUp)
-			}
-			if justEditMP != nil {
-				justEditMP.Prefs = ipn.Prefs{} // uninteresting
-			}
-			if !reflect.DeepEqual(justEditMP, tt.wantJustEditMP) {
-				t.Fatalf("justEditMP: %v", cmp.Diff(justEditMP, tt.wantJustEditMP))
-			}
-		})
-	}
-}

cmd/tailscaled/cli/debug.go

@@ -31,7 +31,6 @@ var debugCmd = &ffcli.Command{
 		fs.BoolVar(&debugArgs.goroutines, "daemon-goroutines", false, "If true, dump the tailscaled daemon's goroutines")
 		fs.BoolVar(&debugArgs.ipn, "ipn", false, "If true, subscribe to IPN notifications")
 		fs.BoolVar(&debugArgs.prefs, "prefs", false, "If true, dump active prefs")
-		fs.BoolVar(&debugArgs.derpMap, "derp", false, "If true, dump DERP map")
 		fs.BoolVar(&debugArgs.pretty, "pretty", false, "If true, pretty-print output (for --prefs)")
 		fs.BoolVar(&debugArgs.netMap, "netmap", true, "whether to include netmap in --ipn mode")
 		fs.BoolVar(&debugArgs.localCreds, "local-creds", false, "print how to connect to local tailscaled")
@@ -45,7 +44,6 @@ var debugArgs struct {
 	goroutines bool
 	ipn        bool
 	netMap     bool
-	derpMap    bool
 	file       string
 	prefs      bool
 	pretty     bool
@@ -89,18 +87,6 @@ func runDebug(ctx context.Context, args []string) error {
 		os.Stdout.Write(goroutines)
 		return nil
 	}
-	if debugArgs.derpMap {
-		dm, err := tailscale.CurrentDERPMap(ctx)
-		if err != nil {
-			return fmt.Errorf(
-				"failed to get local derp map, instead `curl %s/derpmap/default`: %w", ipn.DefaultControlURL, err,
-			)
-		}
-		enc := json.NewEncoder(os.Stdout)
-		enc.SetIndent("", "\t")
-		enc.Encode(dm)
-		return nil
-	}
 	if debugArgs.ipn {
 		c, bc, ctx, cancel := connect(ctx)
 		defer cancel()

cmd/tailscaled/cli/file.go

@@ -74,6 +74,7 @@ func runCp(ctx context.Context, args []string) error {
 		return runCpTargets(ctx, args)
 	}
 	if len(args) < 2 {
+		//lint:ignore ST1005 no sorry need that colon at the end
 		return errors.New("usage: tailscale file cp <files...> <target>:")
 	}
 	files, target := args[:len(args)-1], args[len(args)-1]
@@ -96,12 +97,14 @@ func runCp(ctx context.Context, args []string) error {
 		return err
 	}
 
-	peerAPIBase, isOffline, err := discoverPeerAPIBase(ctx, ip)
+	peerAPIBase, lastSeen, isOffline, err := discoverPeerAPIBase(ctx, ip)
 	if err != nil {
 		return fmt.Errorf("can't send to %s: %v", target, err)
 	}
 	if isOffline {
 		fmt.Fprintf(os.Stderr, "# warning: %s is offline\n", target)
+	} else if !lastSeen.IsZero() && time.Since(lastSeen) > lastSeenOld {
+		fmt.Fprintf(os.Stderr, "# warning: %s last seen %v ago\n", target, time.Since(lastSeen).Round(time.Minute))
 	}
 
 	if len(files) > 1 {
@@ -179,14 +182,14 @@ func runCp(ctx context.Context, args []string) error {
 	return nil
 }
 
-func discoverPeerAPIBase(ctx context.Context, ipStr string) (base string, isOffline bool, err error) {
+func discoverPeerAPIBase(ctx context.Context, ipStr string) (base string, lastSeen time.Time, isOffline bool, err error) {
 	ip, err := netaddr.ParseIP(ipStr)
 	if err != nil {
-		return "", false, err
+		return "", time.Time{}, false, err
 	}
 	fts, err := tailscale.FileTargets(ctx)
 	if err != nil {
-		return "", false, err
+		return "", time.Time{}, false, err
 	}
 	for _, ft := range fts {
 		n := ft.Node
@@ -194,11 +197,14 @@ func discoverPeerAPIBase(ctx context.Context, ipStr string) (base string, isOffl
 			if a.IP() != ip {
 				continue
 			}
+			if n.LastSeen != nil {
+				lastSeen = *n.LastSeen
+			}
 			isOffline = n.Online != nil && !*n.Online
-			return ft.PeerAPIURL, isOffline, nil
+			return ft.PeerAPIURL, lastSeen, isOffline, nil
 		}
 	}
-	return "", false, fileTargetErrorDetail(ctx, ip)
+	return "", time.Time{}, false, fileTargetErrorDetail(ctx, ip)
 }
 
 // fileTargetErrorDetail returns a non-nil error saying why ip is an
@@ -268,6 +274,8 @@ func (r *slowReader) Read(p []byte) (n int, err error) {
 	return
 }
 
+const lastSeenOld = 20 * time.Minute
+
 func runCpTargets(ctx context.Context, args []string) error {
 	if len(args) > 0 {
 		return errors.New("invalid arguments with --targets")

cmd/tailscaled/cli/netcheck.go

@@ -9,18 +9,14 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"io"
-	"io/ioutil"
 	"log"
-	"net/http"
 	"os"
 	"sort"
 	"strings"
 	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/client/tailscale"
-	"tailscale.com/ipn"
+	"tailscale.com/derp/derpmap"
 	"tailscale.com/net/netcheck"
 	"tailscale.com/net/portmapper"
 	"tailscale.com/tailcfg"
@@ -50,7 +46,7 @@ var netcheckArgs struct {
 func runNetcheck(ctx context.Context, args []string) error {
 	c := &netcheck.Client{
 		UDPBindAddr: os.Getenv("TS_DEBUG_NETCHECK_UDP_BIND"),
-		PortMapper:  portmapper.NewClient(logger.WithPrefix(log.Printf, "portmap: "), nil),
+		PortMapper:  portmapper.NewClient(logger.WithPrefix(log.Printf, "portmap: ")),
 	}
 	if netcheckArgs.verbose {
 		c.Logf = logger.WithPrefix(log.Printf, "netcheck: ")
@@ -63,13 +59,7 @@ func runNetcheck(ctx context.Context, args []string) error {
 		fmt.Fprintln(os.Stderr, "# Warning: this JSON format is not yet considered a stable interface")
 	}
 
-	dm, err := tailscale.CurrentDERPMap(ctx)
-	if err != nil {
-		dm, err = prodDERPMap(ctx, http.DefaultClient)
-		if err != nil {
-			return err
-		}
-	}
+	dm := derpmap.Prod()
 	for {
 		t0 := time.Now()
 		report, err := c.GetReport(ctx, dm)
@@ -186,27 +176,3 @@ func portMapping(r *netcheck.Report) string {
 	}
 	return strings.Join(got, ", ")
 }
-
-func prodDERPMap(ctx context.Context, httpc *http.Client) (*tailcfg.DERPMap, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", ipn.DefaultControlURL+"/derpmap/default", nil)
-	if err != nil {
-		return nil, fmt.Errorf("create prodDERPMap request: %w", err)
-	}
-	res, err := httpc.Do(req)
-	if err != nil {
-		return nil, fmt.Errorf("fetch prodDERPMap failed: %w", err)
-	}
-	defer res.Body.Close()
-	b, err := ioutil.ReadAll(io.LimitReader(res.Body, 1<<20))
-	if err != nil {
-		return nil, fmt.Errorf("fetch prodDERPMap failed: %w", err)
-	}
-	if res.StatusCode != 200 {
-		return nil, fmt.Errorf("fetch prodDERPMap: %v: %s", res.Status, b)
-	}
-	var derpMap tailcfg.DERPMap
-	if err = json.Unmarshal(b, &derpMap); err != nil {
-		return nil, fmt.Errorf("fetch prodDERPMap: %w", err)
-	}
-	return &derpMap, nil
-}

cmd/tailscaled/cli/status.go

@@ -14,6 +14,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
 	"github.com/toqueteos/webbrowser"
@@ -56,12 +57,12 @@ var statusArgs struct {
 func runStatus(ctx context.Context, args []string) error {
 	st, err := tailscale.Status(ctx)
 	if err != nil {
-		return fixTailscaledConnectError(err)
+		return err
 	}
 	if statusArgs.json {
 		if statusArgs.active {
 			for peer, ps := range st.Peer {
-				if !ps.Active {
+				if !peerActive(ps) {
 					delete(st.Peer, peer)
 				}
 			}
@@ -129,6 +130,7 @@ func runStatus(ctx context.Context, args []string) error {
 	var buf bytes.Buffer
 	f := func(format string, a ...interface{}) { fmt.Fprintf(&buf, format, a...) }
 	printPS := func(ps *ipnstate.PeerStatus) {
+		active := peerActive(ps)
 		f("%-15s %-20s %-12s %-7s ",
 			firstIPString(ps.TailscaleIPs),
 			dnsOrQuoteHostname(st, ps),
@@ -137,7 +139,7 @@ func runStatus(ctx context.Context, args []string) error {
 		)
 		relay := ps.Relay
 		anyTraffic := ps.TxBytes != 0 || ps.RxBytes != 0
-		if !ps.Active {
+		if !active {
 			if ps.ExitNode {
 				f("idle; exit node")
 			} else if anyTraffic {
@@ -176,7 +178,8 @@ func runStatus(ctx context.Context, args []string) error {
 		}
 		ipnstate.SortPeers(peers)
 		for _, ps := range peers {
-			if statusArgs.active && !ps.Active {
+			active := peerActive(ps)
+			if statusArgs.active && !active {
 				continue
 			}
 			printPS(ps)
@@ -186,6 +189,13 @@ func runStatus(ctx context.Context, args []string) error {
 	return nil
 }
 
+// peerActive reports whether ps has recent activity.
+//
+// TODO: have the server report this bool instead.
+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 != "" {

cmd/tailscaled/cli/up.go

@@ -51,14 +51,7 @@ flag is also used.
 	Exec:    runUp,
 }
 
-func effectiveGOOS() string {
-	if v := os.Getenv("TS_DEBUG_UP_FLAG_GOOS"); v != "" {
-		return v
-	}
-	return runtime.GOOS
-}
-
-var upFlagSet = newUpFlagSet(effectiveGOOS(), &upArgs)
+var upFlagSet = newUpFlagSet(runtime.GOOS, &upArgs)
 
 func newUpFlagSet(goos string, upArgs *upArgsT) *flag.FlagSet {
 	upf := flag.NewFlagSet("up", flag.ExitOnError)
@@ -70,13 +63,13 @@ func newUpFlagSet(goos string, upArgs *upArgsT) *flag.FlagSet {
 	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, or empty string to not use an exit node")
+	upf.StringVar(&upArgs.exitNodeIP, "exit-node", "", "Tailscale IP of the exit node for internet traffic")
 	upf.BoolVar(&upArgs.exitNodeAllowLANAccess, "exit-node-allow-lan-access", false, "Allow direct access to the local network when routing traffic via an exit node")
 	upf.BoolVar(&upArgs.shieldsUp, "shields-up", false, "don't allow incoming connections")
 	upf.StringVar(&upArgs.advertiseTags, "advertise-tags", "", "comma-separated ACL tags to request; each must start with \"tag:\" (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")
-	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\") or empty string to not advertise routes")
+	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 safesocket.GOOSUsesPeerCreds(goos) {
 		upf.StringVar(&upArgs.opUser, "operator", "", "Unix username to allow to operate on tailscaled without sudo")
@@ -237,9 +230,7 @@ func prefsFromUpArgs(upArgs upArgsT, warnf logger.Logf, st *ipnstate.Status, goo
 			warnf("netfilter=nodivert; add iptables calls to ts-* chains manually.")
 		case "off":
 			prefs.NetfilterMode = preftype.NetfilterOff
-			if defaultNetfilterMode() != "off" {
-				warnf("netfilter=off; configure iptables yourself.")
-			}
+			warnf("netfilter=off; configure iptables yourself.")
 		default:
 			return nil, fmt.Errorf("invalid value --netfilter-mode=%q", upArgs.netfilterMode)
 		}
@@ -247,53 +238,6 @@ func prefsFromUpArgs(upArgs upArgsT, warnf logger.Logf, st *ipnstate.Status, goo
 	return prefs, nil
 }
 
-// updatePrefs updates prefs based on curPrefs
-//
-// It returns a non-nil justEditMP if we're already running and none of
-// the flags require a restart, so we can just do an EditPrefs call and
-// change the prefs at runtime (e.g. changing hostname, changing
-// advertised tags, routes, etc).
-//
-// It returns simpleUp if we're running a simple "tailscale up" to
-// transition to running from a previously-logged-in but down state,
-// without changing any settings.
-func updatePrefs(prefs, curPrefs *ipn.Prefs, env upCheckEnv) (simpleUp bool, justEditMP *ipn.MaskedPrefs, err error) {
-	if !env.upArgs.reset {
-		applyImplicitPrefs(prefs, curPrefs, env.user)
-
-		if err := checkForAccidentalSettingReverts(prefs, curPrefs, env); err != nil {
-			return false, nil, err
-		}
-	}
-
-	controlURLChanged := curPrefs.ControlURL != prefs.ControlURL &&
-		!(ipn.IsLoginServerSynonym(curPrefs.ControlURL) && ipn.IsLoginServerSynonym(prefs.ControlURL))
-	if controlURLChanged && env.backendState == ipn.Running.String() && !env.upArgs.forceReauth {
-		return false, nil, fmt.Errorf("can't change --login-server without --force-reauth")
-	}
-
-	simpleUp = env.flagSet.NFlag() == 0 &&
-		curPrefs.Persist != nil &&
-		curPrefs.Persist.LoginName != "" &&
-		env.backendState != ipn.NeedsLogin.String()
-
-	justEdit := env.backendState == ipn.Running.String() &&
-		!env.upArgs.forceReauth &&
-		!env.upArgs.reset &&
-		env.upArgs.authKey == "" &&
-		!controlURLChanged
-	if justEdit {
-		justEditMP = new(ipn.MaskedPrefs)
-		justEditMP.WantRunningSet = true
-		justEditMP.Prefs = *prefs
-		env.flagSet.Visit(func(f *flag.Flag) {
-			updateMaskedPrefsFromUpFlag(justEditMP, f.Name)
-		})
-	}
-
-	return simpleUp, justEditMP, nil
-}
-
 func runUp(ctx context.Context, args []string) error {
 	if len(args) > 0 {
 		fatalf("too many non-flag arguments: %q", args)
@@ -301,7 +245,7 @@ func runUp(ctx context.Context, args []string) error {
 
 	st, err := tailscale.Status(ctx)
 	if err != nil {
-		return fixTailscaledConnectError(err)
+		fatalf("can't fetch status from tailscaled: %v", err)
 	}
 	origAuthURL := st.AuthURL
 
@@ -322,7 +266,7 @@ func runUp(ctx context.Context, args []string) error {
 	}
 
 	if distro.Get() == distro.Synology {
-		notSupported := "not supported on Synology; see https://github.com/tailscale/tailscale/issues/1995"
+		notSupported := "not yet supported on Synology; see https://github.com/tailscale/tailscale/issues/451"
 		if upArgs.acceptRoutes {
 			return errors.New("--accept-routes is " + notSupported)
 		}
@@ -334,7 +278,7 @@ func runUp(ctx context.Context, args []string) error {
 		}
 	}
 
-	prefs, err := prefsFromUpArgs(upArgs, warnf, st, effectiveGOOS())
+	prefs, err := prefsFromUpArgs(upArgs, warnf, st, runtime.GOOS)
 	if err != nil {
 		fatalf("%s", err)
 	}
@@ -350,23 +294,51 @@ func runUp(ctx context.Context, args []string) error {
 		return err
 	}
 
-	env := upCheckEnv{
-		goos:          effectiveGOOS(),
-		user:          os.Getenv("USER"),
-		flagSet:       upFlagSet,
-		upArgs:        upArgs,
-		backendState:  st.BackendState,
-		curExitNodeIP: exitNodeIP(prefs, st),
+	if !upArgs.reset {
+		applyImplicitPrefs(prefs, curPrefs, os.Getenv("USER"))
+
+		if err := checkForAccidentalSettingReverts(upFlagSet, curPrefs, prefs, upCheckEnv{
+			goos:          runtime.GOOS,
+			curExitNodeIP: exitNodeIP(prefs, st),
+		}); err != nil {
+			fatalf("%s", err)
+		}
 	}
-	simpleUp, justEditMP, err := updatePrefs(prefs, curPrefs, env)
-	if err != nil {
-		fatalf("%s", err)
+
+	controlURLChanged := curPrefs.ControlURL != prefs.ControlURL
+	if controlURLChanged && st.BackendState == ipn.Running.String() && !upArgs.forceReauth {
+		fatalf("can't change --login-server without --force-reauth")
 	}
-	if justEditMP != nil {
-		_, err := tailscale.EditPrefs(ctx, justEditMP)
+
+	// If we're already running and none of the flags require a
+	// restart, we can just do an EditPrefs call and change the
+	// prefs at runtime (e.g. changing hostname, changing
+	// advertised tags, routes, etc)
+	justEdit := st.BackendState == ipn.Running.String() &&
+		!upArgs.forceReauth &&
+		!upArgs.reset &&
+		upArgs.authKey == "" &&
+		!controlURLChanged
+	if justEdit {
+		mp := new(ipn.MaskedPrefs)
+		mp.WantRunningSet = true
+		mp.Prefs = *prefs
+		upFlagSet.Visit(func(f *flag.Flag) {
+			updateMaskedPrefsFromUpFlag(mp, f.Name)
+		})
+
+		_, err := tailscale.EditPrefs(ctx, mp)
 		return err
 	}
 
+	// simpleUp is whether we're running a simple "tailscale up"
+	// to transition to running from a previously-logged-in but
+	// down state, without changing any settings.
+	simpleUp := upFlagSet.NFlag() == 0 &&
+		curPrefs.Persist != nil &&
+		curPrefs.Persist.LoginName != "" &&
+		st.BackendState != ipn.NeedsLogin.String()
+
 	// At this point we need to subscribe to the IPN bus to watch
 	// for state transitions and possible need to authenticate.
 	c, bc, pumpCtx, cancel := connect(ctx)
@@ -391,7 +363,7 @@ func runUp(ctx context.Context, args []string) error {
 		if n.ErrMessage != nil {
 			msg := *n.ErrMessage
 			if msg == ipn.ErrMsgPermissionDenied {
-				switch effectiveGOOS() {
+				switch runtime.GOOS {
 				case "windows":
 					msg += " (Tailscale service in use by other user?)"
 				default:
@@ -407,7 +379,7 @@ func runUp(ctx context.Context, args []string) error {
 				startLoginInteractive()
 			case ipn.NeedsMachineAuth:
 				printed = true
-				fmt.Fprintf(os.Stderr, "\nTo authorize your machine, visit (as admin):\n\n\t%s\n\n", prefs.AdminPageURL())
+				fmt.Fprintf(os.Stderr, "\nTo authorize your machine, visit (as admin):\n\n\t%s/admin/machines\n\n", upArgs.server)
 			case ipn.Starting, ipn.Running:
 				// Done full authentication process
 				if printed {
@@ -465,7 +437,7 @@ func runUp(ctx context.Context, args []string) error {
 		// Windows service (~tailscaled) is the one that computes the
 		// StateKey based on the connection identity. So for now, just
 		// do as the Windows GUI's always done:
-		if effectiveGOOS() == "windows" {
+		if runtime.GOOS == "windows" {
 			// The Windows service will set this as needed based
 			// on our connection's identity.
 			opts.StateKey = ""
@@ -478,13 +450,6 @@ func runUp(ctx context.Context, args []string) error {
 		}
 	}
 
-	// This whole 'up' mechanism is too complicated and results in
-	// hairy stuff like this select. We're ultimately waiting for
-	// 'startingOrRunning' to be done, but even in the case where
-	// it succeeds, other parts may shut down concurrently so we
-	// need to prioritize reads from 'startingOrRunning' if it's
-	// readable; its send does happen before the pump mechanism
-	// shuts down. (Issue 2333)
 	select {
 	case <-startingOrRunning:
 		return nil
@@ -496,11 +461,6 @@ func runUp(ctx context.Context, args []string) error {
 		}
 		return pumpCtx.Err()
 	case err := <-pumpErr:
-		select {
-		case <-startingOrRunning:
-			return nil
-		default:
-		}
 		return err
 	}
 }
@@ -576,10 +536,6 @@ const accidentalUpPrefix = "Error: changing settings via 'tailscale up' requires
 // needed by checkForAccidentalSettingReverts and friends.
 type upCheckEnv struct {
 	goos          string
-	user          string
-	flagSet       *flag.FlagSet
-	upArgs        upArgsT
-	backendState  string
 	curExitNodeIP netaddr.IP
 }
 
@@ -597,14 +553,14 @@ type upCheckEnv struct {
 //
 // mp is the mask of settings actually set, where mp.Prefs is the new
 // preferences to set, including any values set from implicit flags.
-func checkForAccidentalSettingReverts(newPrefs, curPrefs *ipn.Prefs, env upCheckEnv) error {
+func checkForAccidentalSettingReverts(flagSet *flag.FlagSet, curPrefs, newPrefs *ipn.Prefs, env upCheckEnv) error {
 	if curPrefs.ControlURL == "" {
 		// Don't validate things on initial "up" before a control URL has been set.
 		return nil
 	}
 
 	flagIsSet := map[string]bool{}
-	env.flagSet.Visit(func(f *flag.Flag) {
+	flagSet.Visit(func(f *flag.Flag) {
 		flagIsSet[f.Name] = true
 	})
 
@@ -628,9 +584,6 @@ func checkForAccidentalSettingReverts(newPrefs, curPrefs *ipn.Prefs, env upCheck
 		if reflect.DeepEqual(valCur, valNew) {
 			continue
 		}
-		if flagName == "login-server" && ipn.IsLoginServerSynonym(valCur) && ipn.IsLoginServerSynonym(valNew) {
-			continue
-		}
 		missing = append(missing, fmtFlagValueArg(flagName, valCur))
 	}
 	if len(missing) == 0 {
@@ -641,7 +594,7 @@ func checkForAccidentalSettingReverts(newPrefs, curPrefs *ipn.Prefs, env upCheck
 	// Compute the stringification of the explicitly provided args in flagSet
 	// to prepend to the command to run.
 	var explicit []string
-	env.flagSet.Visit(func(f *flag.Flag) {
+	flagSet.Visit(func(f *flag.Flag) {
 		type isBool interface {
 			IsBoolFlag() bool
 		}

cmd/tailscaled/cli/web.go

@@ -9,16 +9,12 @@ import (
 	"context"
 	_ "embed"
 	"encoding/json"
-	"encoding/xml"
 	"flag"
 	"fmt"
 	"html/template"
-	"io/ioutil"
 	"log"
-	"net"
 	"net/http"
 	"net/http/cgi"
-	"net/url"
 	"os/exec"
 	"runtime"
 	"strings"
@@ -28,7 +24,6 @@ import (
 	"tailscale.com/ipn"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/preftype"
-	"tailscale.com/util/groupmember"
 	"tailscale.com/version/distro"
 )
 
@@ -38,9 +33,6 @@ var webHTML string
 //go:embed web.css
 var webCSS string
 
-//go:embed auth-redirect.html
-var authenticationRedirectHTML string
-
 var tmpl *template.Template
 
 func init() {
@@ -61,14 +53,6 @@ var webCmd = &ffcli.Command{
 	ShortUsage: "web [flags]",
 	ShortHelp:  "Run a web server for controlling Tailscale",
 
-	LongHelp: strings.TrimSpace(`
-"tailscale web" runs a webserver for controlling the Tailscale daemon.
-
-It's primarily intended for use on Synology, QNAP, and other
-NAS devices where a web interface is the natural place to control
-Tailscale, as opposed to a CLI or a native app.
-`),
-
 	FlagSet: (func() *flag.FlagSet {
 		webf := flag.NewFlagSet("web", flag.ExitOnError)
 		webf.StringVar(&webArgs.listen, "listen", "localhost:8088", "listen address; use port 0 for automatic")
@@ -95,128 +79,26 @@ func runWeb(ctx context.Context, args []string) error {
 		}
 		return nil
 	}
-
-	log.Printf("web server running on: %s", urlOfListenAddr(webArgs.listen))
 	return http.ListenAndServe(webArgs.listen, http.HandlerFunc(webHandler))
 }
 
-// urlOfListenAddr parses a given listen address into a formatted URL
-func urlOfListenAddr(addr string) string {
-	host, port, _ := net.SplitHostPort(addr)
-	if host == "" {
-		host = "127.0.0.1"
+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 fmt.Sprintf("http://%s", net.JoinHostPort(host, port))
-}
 
-// authorize returns the name of the user accessing the web UI after verifying
-// whether the user has access to the web UI. The function will write the
-// error to the provided http.ResponseWriter.
-// Note: This is different from a tailscale user, and is typically the local
-// user on the node.
-func authorize(w http.ResponseWriter, r *http.Request) (string, error) {
-	switch distro.Get() {
-	case distro.Synology:
-		user, err := synoAuthn()
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusUnauthorized)
-			return "", err
-		}
-		if err := authorizeSynology(user); err != nil {
-			http.Error(w, err.Error(), http.StatusForbidden)
-			return "", err
-		}
-		return user, nil
-	case distro.QNAP:
-		user, resp, err := qnapAuthn(r)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusUnauthorized)
-			return "", err
-		}
-		if resp.IsAdmin == 0 {
-			http.Error(w, err.Error(), http.StatusForbidden)
-			return "", err
-		}
-		return user, nil
-	}
 	return "", nil
 }
 
-// authorizeSynology checks whether the provided user has access to the web UI
-// by consulting the membership of the "administrators" group.
-func authorizeSynology(name string) error {
-	yes, err := groupmember.IsMemberOfGroup("administrators", name)
-	if err != nil {
-		return err
-	}
-	if !yes {
-		return fmt.Errorf("not a member of administrators group")
-	}
-	return nil
-}
-
-type qnapAuthResponse struct {
-	AuthPassed int    `xml:"authPassed"`
-	IsAdmin    int    `xml:"isAdmin"`
-	AuthSID    string `xml:"authSid"`
-	ErrorValue int    `xml:"errorValue"`
-}
-
-func qnapAuthn(r *http.Request) (string, *qnapAuthResponse, error) {
-	user, err := r.Cookie("NAS_USER")
-	if err != nil {
-		return "", nil, err
-	}
-	token, err := r.Cookie("qtoken")
-	if err != nil {
-		return "", nil, err
-	}
-	query := url.Values{
-		"qtoken": []string{token.Value},
-		"user":   []string{user.Value},
-	}
-	u := url.URL{
-		Scheme:   r.URL.Scheme,
-		Host:     r.URL.Host,
-		Path:     "/cgi-bin/authLogin.cgi",
-		RawQuery: query.Encode(),
-	}
-	resp, err := http.Get(u.String())
-	if err != nil {
-		return "", nil, err
-	}
-	defer resp.Body.Close()
-	out, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return "", nil, err
-	}
-	authResp := &qnapAuthResponse{}
-	if err := xml.Unmarshal(out, authResp); err != nil {
-		return "", nil, err
-	}
-	if authResp.AuthPassed == 0 {
-		return "", nil, fmt.Errorf("not authenticated")
-	}
-	return user.Value, authResp, nil
-}
-
-func synoAuthn() (string, error) {
-	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 strings.TrimSpace(string(out)), nil
-}
-
-func authRedirect(w http.ResponseWriter, r *http.Request) bool {
-	if distro.Get() == distro.Synology {
-		return synoTokenRedirect(w, r)
-	}
-	return false
-}
-
 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
 	}
@@ -250,13 +132,75 @@ req.send(null);
 </body></html>
 `
 
+const authenticationRedirectHTML = `
+<html>
+<head>
+	<title>Redirecting...</title>
+	<style>
+		html,
+		body {
+			height: 100%;
+		}
+
+		html {
+			background-color: rgb(249, 247, 246);
+			font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
+			line-height: 1.5;
+			-webkit-text-size-adjust: 100%;
+			-webkit-font-smoothing: antialiased;
+			-moz-osx-font-smoothing: grayscale;
+		}
+
+		body {
+			display: flex;
+			flex-direction: column;
+			align-items: center;
+			justify-content: center;
+		}
+
+		.spinner {
+			margin-bottom: 2rem;
+			border: 4px rgba(112, 110, 109, 0.5) solid;
+			border-left-color: transparent;
+			border-radius: 9999px;
+			width: 4rem;
+			height: 4rem;
+			-webkit-animation: spin 700ms linear infinite;
+      animation: spin 800ms linear infinite;
+		}
+
+		.label {
+			color: rgb(112, 110, 109);
+			padding-left: 0.4rem;
+		}
+
+		@-webkit-keyframes spin {
+			to {
+				transform: rotate(360deg);
+			}
+		}
+
+		@keyframes spin {
+			to {
+				transform: rotate(360deg);
+			}
+		}
+	</style>
+</head>
+<body>
+	<div class="spinner"></div>
+	<div class="label">Redirecting...</div>
+</body>
+`
+
 func webHandler(w http.ResponseWriter, r *http.Request) {
-	if authRedirect(w, r) {
+	if synoTokenRedirect(w, r) {
 		return
 	}
 
-	user, err := authorize(w, r)
+	user, err := auth()
 	if err != nil {
+		http.Error(w, err.Error(), http.StatusForbidden)
 		return
 	}
 
@@ -270,8 +214,7 @@ func webHandler(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 		url, err := tailscaleUpForceReauth(r.Context())
 		if err != nil {
-			w.WriteHeader(http.StatusInternalServerError)
-			json.NewEncoder(w).Encode(mi{"error": err.Error()})
+			json.NewEncoder(w).Encode(mi{"error": err})
 			return
 		}
 		json.NewEncoder(w).Encode(mi{"url": url})
@@ -280,7 +223,7 @@ func webHandler(w http.ResponseWriter, r *http.Request) {
 
 	st, err := tailscale.Status(r.Context())
 	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		http.Error(w, err.Error(), 500)
 		return
 	}
 
@@ -298,7 +241,7 @@ func webHandler(w http.ResponseWriter, r *http.Request) {
 
 	buf := new(bytes.Buffer)
 	if err := tmpl.Execute(buf, data); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		http.Error(w, err.Error(), 500)
 		return
 	}
 	w.Write(buf.Bytes())
@@ -377,10 +320,6 @@ func tailscaleUpForceReauth(ctx context.Context) (authURL string, retErr error)
 	})
 	bc.StartLoginInteractive()
 
-	<-pumpCtx.Done() // wait for authURL or complete failure
-	if authURL == "" && retErr == nil {
-		retErr = pumpCtx.Err()
-	}
 	if authURL == "" && retErr == nil {
 		return "", fmt.Errorf("login failed with no backend error message")
 	}

cmd/tailscaled/cli/web.html

@@ -28,7 +28,7 @@
 		<div class="flex items-center justify-end space-x-2 w-2/3">
 			{{ with .Profile.LoginName }}
 			<div class="text-right truncate leading-4">
-				<h4 class="truncate leading-normal">{{.}}</h4>
+				<h4 class="truncate">{{.}}</h4>
 				<a href="#" class="text-xs text-gray-500 hover:text-gray-700 js-loginButton">Switch account</a>
 			</div>
 			{{ end }}

cmd/tailscaled/debug.go

@@ -11,44 +11,33 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io"
-	"io/ioutil"
 	"log"
-	"net"
 	"net/http"
 	"net/http/httptrace"
 	"net/url"
 	"os"
-	"strings"
 	"time"
 
-	"inet.af/netaddr"
 	"tailscale.com/derp/derphttp"
-	"tailscale.com/ipn"
+	"tailscale.com/derp/derpmap"
 	"tailscale.com/net/interfaces"
-	"tailscale.com/net/portmapper"
 	"tailscale.com/net/tshttpproxy"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
-	"tailscale.com/types/logger"
 	"tailscale.com/wgengine/monitor"
 )
 
 var debugArgs struct {
-	ifconfig  bool // print network state once and exit
 	monitor   bool
 	getURL    string
 	derpCheck string
-	portmap   bool
 }
 
 var debugModeFunc = debugMode // so it can be addressable
 
 func debugMode(args []string) error {
 	fs := flag.NewFlagSet("debug", flag.ExitOnError)
-	fs.BoolVar(&debugArgs.ifconfig, "ifconfig", false, "If true, print network interface state")
 	fs.BoolVar(&debugArgs.monitor, "monitor", false, "If true, run link monitor forever. Precludes all other options.")
-	fs.BoolVar(&debugArgs.portmap, "portmap", false, "If true, run portmap debugging. 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 {
@@ -61,14 +50,8 @@ func debugMode(args []string) error {
 	if debugArgs.derpCheck != "" {
 		return checkDerp(ctx, debugArgs.derpCheck)
 	}
-	if debugArgs.ifconfig {
-		return runMonitor(ctx, false)
-	}
 	if debugArgs.monitor {
-		return runMonitor(ctx, true)
-	}
-	if debugArgs.portmap {
-		return debugPortmap(ctx)
+		return runMonitor(ctx)
 	}
 	if debugArgs.getURL != "" {
 		return getURL(ctx, debugArgs.getURL)
@@ -76,7 +59,7 @@ func debugMode(args []string) error {
 	return errors.New("only --monitor is available at the moment")
 }
 
-func runMonitor(ctx context.Context, loop bool) error {
+func runMonitor(ctx context.Context) error {
 	dump := func(st *interfaces.State) {
 		j, _ := json.MarshalIndent(st, "", "    ")
 		os.Stderr.Write(j)
@@ -93,13 +76,8 @@ func runMonitor(ctx context.Context, loop bool) error {
 		log.Printf("Link monitor fired. New state:")
 		dump(st)
 	})
-	if loop {
-		log.Printf("Starting link change monitor; initial state:")
-	}
+	log.Printf("Starting link change monitor; initial state:")
 	dump(mon.InterfaceState())
-	if !loop {
-		return nil
-	}
 	mon.Start()
 	log.Printf("Started link change monitor; waiting...")
 	select {}
@@ -153,26 +131,7 @@ func getURL(ctx context.Context, urlStr string) error {
 }
 
 func checkDerp(ctx context.Context, derpRegion string) error {
-	req, err := http.NewRequestWithContext(ctx, "GET", ipn.DefaultControlURL+"/derpmap/default", nil)
-	if err != nil {
-		return fmt.Errorf("create derp map request: %w", err)
-	}
-	res, err := http.DefaultClient.Do(req)
-	if err != nil {
-		return fmt.Errorf("fetch derp map failed: %w", err)
-	}
-	defer res.Body.Close()
-	b, err := ioutil.ReadAll(io.LimitReader(res.Body, 1<<20))
-	if err != nil {
-		return fmt.Errorf("fetch derp map failed: %w", err)
-	}
-	if res.StatusCode != 200 {
-		return fmt.Errorf("fetch derp map: %v: %s", res.Status, b)
-	}
-	var dmap tailcfg.DERPMap
-	if err = json.Unmarshal(b, &dmap); err != nil {
-		return fmt.Errorf("fetch DERP map: %w", err)
-	}
+	dmap := derpmap.Prod()
 	getRegion := func() *tailcfg.DERPRegion {
 		for _, r := range dmap.Regions {
 			if r.RegionCode == derpRegion {
@@ -211,97 +170,3 @@ func checkDerp(ctx context.Context, derpRegion string) error {
 	log.Printf("ok")
 	return err
 }
-
-func debugPortmap(ctx context.Context) error {
-	ctx, cancel := context.WithTimeout(ctx, 3*time.Second)
-	defer cancel()
-
-	portmapper.VerboseLogs = true
-	switch os.Getenv("TS_DEBUG_PORTMAP_TYPE") {
-	case "":
-	case "pmp":
-		portmapper.DisablePCP = true
-		portmapper.DisableUPnP = true
-	case "pcp":
-		portmapper.DisablePMP = true
-		portmapper.DisableUPnP = true
-	case "upnp":
-		portmapper.DisablePCP = true
-		portmapper.DisablePMP = true
-	default:
-		log.Fatalf("TS_DEBUG_PORTMAP_TYPE must be one of pmp,pcp,upnp")
-	}
-
-	done := make(chan bool, 1)
-
-	var c *portmapper.Client
-	logf := log.Printf
-	c = portmapper.NewClient(logger.WithPrefix(logf, "portmapper: "), func() {
-		logf("portmapping changed.")
-		logf("have mapping: %v", c.HaveMapping())
-
-		if ext, ok := c.GetCachedMappingOrStartCreatingOne(); ok {
-			logf("cb: mapping: %v", ext)
-			select {
-			case done <- true:
-			default:
-			}
-			return
-		}
-		logf("cb: no mapping")
-	})
-	linkMon, err := monitor.New(logger.WithPrefix(logf, "monitor: "))
-	if err != nil {
-		return err
-	}
-
-	gatewayAndSelfIP := func() (gw, self netaddr.IP, ok bool) {
-		if v := os.Getenv("TS_DEBUG_GW_SELF"); strings.Contains(v, "/") {
-			i := strings.Index(v, "/")
-			gw = netaddr.MustParseIP(v[:i])
-			self = netaddr.MustParseIP(v[i+1:])
-			return gw, self, true
-		}
-		return linkMon.GatewayAndSelfIP()
-	}
-
-	c.SetGatewayLookupFunc(gatewayAndSelfIP)
-
-	gw, selfIP, ok := gatewayAndSelfIP()
-	if !ok {
-		logf("no gateway or self IP; %v", linkMon.InterfaceState())
-		return nil
-	}
-	logf("gw=%v; self=%v", gw, selfIP)
-
-	uc, err := net.ListenPacket("udp", "0.0.0.0:0")
-	if err != nil {
-		return err
-	}
-	defer uc.Close()
-	c.SetLocalPort(uint16(uc.LocalAddr().(*net.UDPAddr).Port))
-
-	res, err := c.Probe(ctx)
-	if err != nil {
-		return fmt.Errorf("Probe: %v", err)
-	}
-	logf("Probe: %+v", res)
-
-	if !res.PCP && !res.PMP && !res.UPnP {
-		logf("no portmapping services available")
-		return nil
-	}
-
-	if ext, ok := c.GetCachedMappingOrStartCreatingOne(); ok {
-		logf("mapping: %v", ext)
-	} else {
-		logf("no mapping")
-	}
-
-	select {
-	case <-done:
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
-	}
-}

cmd/tailscaled/depaware.txt

@@ -1,60 +1,43 @@
 tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/depaware)
 
-   W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate+
-   W    github.com/alexbrainman/sspi/internal/common                 from github.com/alexbrainman/sspi/negotiate
+   W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate
    W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
    L    github.com/coreos/go-iptables/iptables                       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/net/dns
-        github.com/golang/snappy                                     from github.com/klauspost/compress/zstd
         github.com/google/btree                                      from inet.af/netstack/tcpip/header+
-   L    github.com/insomniacslk/dhcp/dhcpv4                          from tailscale.com/net/tstun
-   L    github.com/insomniacslk/dhcp/iana                            from github.com/insomniacslk/dhcp/dhcpv4
-   L    github.com/insomniacslk/dhcp/interfaces                      from github.com/insomniacslk/dhcp/dhcpv4
-   L    github.com/insomniacslk/dhcp/rfc1035label                    from github.com/insomniacslk/dhcp/dhcpv4
    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
+        github.com/klauspost/compress/snappy                         from github.com/klauspost/compress/zstd
         github.com/klauspost/compress/zstd                           from tailscale.com/smallzstd
         github.com/klauspost/compress/zstd/internal/xxhash           from github.com/klauspost/compress/zstd
-   L 💣 github.com/mdlayher/netlink                                  from tailscale.com/wgengine/monitor+
-   L 💣 github.com/mdlayher/netlink/nlenc                            from github.com/mdlayher/netlink+
+   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
-   L 💣 github.com/mdlayher/socket                                   from github.com/mdlayher/netlink
-   W    github.com/pkg/errors                                        from github.com/tailscale/certstore
-   W 💣 github.com/tailscale/certstore                               from tailscale.com/control/controlclient
-        github.com/tailscale/goupnp                                  from github.com/tailscale/goupnp/dcps/internetgateway2+
-        github.com/tailscale/goupnp/dcps/internetgateway2            from tailscale.com/net/portmapper
-        github.com/tailscale/goupnp/httpu                            from github.com/tailscale/goupnp+
-        github.com/tailscale/goupnp/scpd                             from github.com/tailscale/goupnp
-        github.com/tailscale/goupnp/soap                             from github.com/tailscale/goupnp+
-        github.com/tailscale/goupnp/ssdp                             from github.com/tailscale/goupnp
+   W    github.com/pkg/errors                                        from github.com/github/certstore
+     💣 github.com/tailscale/wireguard-go/conn                       from github.com/tailscale/wireguard-go/device+
+   W 💣 github.com/tailscale/wireguard-go/conn/winrio                from github.com/tailscale/wireguard-go/conn
+     💣 github.com/tailscale/wireguard-go/device                     from tailscale.com/wgengine+
+     💣 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+
         github.com/tcnksm/go-httpstat                                from tailscale.com/net/netcheck
-   L    github.com/u-root/uio/rand                                   from github.com/insomniacslk/dhcp/dhcpv4
-   L    github.com/u-root/uio/ubinary                                from github.com/u-root/uio/uio
-   L    github.com/u-root/uio/uio                                    from github.com/insomniacslk/dhcp/dhcpv4+
      💣 go4.org/intern                                               from inet.af/netaddr
-     💣 go4.org/mem                                                  from tailscale.com/derp+
+     💣 go4.org/mem                                                  from tailscale.com/control/controlclient+
         go4.org/unsafe/assume-no-moving-gc                           from go4.org/intern
-     💣 golang.zx2c4.com/wireguard/conn                              from golang.zx2c4.com/wireguard/device+
-   W 💣 golang.zx2c4.com/wireguard/conn/winrio                       from golang.zx2c4.com/wireguard/conn
-     💣 golang.zx2c4.com/wireguard/device                            from tailscale.com/net/tstun+
-     💣 golang.zx2c4.com/wireguard/ipc                               from golang.zx2c4.com/wireguard/device
-   W 💣 golang.zx2c4.com/wireguard/ipc/winpipe                       from golang.zx2c4.com/wireguard/ipc
-        golang.zx2c4.com/wireguard/ratelimiter                       from golang.zx2c4.com/wireguard/device
-        golang.zx2c4.com/wireguard/replay                            from golang.zx2c4.com/wireguard/device
-        golang.zx2c4.com/wireguard/rwcancel                          from golang.zx2c4.com/wireguard/device+
-        golang.zx2c4.com/wireguard/tai64n                            from golang.zx2c4.com/wireguard/device+
-     💣 golang.zx2c4.com/wireguard/tun                               from golang.zx2c4.com/wireguard/device+
-   W 💣 golang.zx2c4.com/wireguard/tun/wintun                        from golang.zx2c4.com/wireguard/tun+
    W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
         inet.af/netaddr                                              from tailscale.com/control/controlclient+
-        inet.af/netstack/atomicbitops                                from inet.af/netstack/tcpip+
-     💣 inet.af/netstack/buffer                                      from inet.af/netstack/tcpip/stack
      💣 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+
@@ -63,7 +46,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
      💣 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                                       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+
@@ -73,7 +56,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         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/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+
@@ -86,17 +69,16 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         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
-   W 💣 inet.af/wf                                                   from tailscale.com/wf
+        rsc.io/goversion/version                                     from tailscale.com/version
         tailscale.com/atomicfile                                     from tailscale.com/ipn+
-        tailscale.com/client/tailscale                               from tailscale.com/derp
         tailscale.com/client/tailscale/apitype                       from tailscale.com/ipn/ipnlocal+
         tailscale.com/control/controlclient                          from tailscale.com/ipn/ipnlocal+
-        tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
         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/health                                         from tailscale.com/control/controlclient+
-        tailscale.com/hostinfo                                       from tailscale.com/control/controlclient+
+        tailscale.com/internal/deephash                              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
@@ -121,8 +103,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
      💣 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/net/socks5/tssocks
-        tailscale.com/net/socks5/tssocks                             from tailscale.com/cmd/tailscaled
+        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/ipnlocal+
@@ -130,15 +111,13 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/net/tstun                                      from tailscale.com/cmd/tailscaled+
         tailscale.com/paths                                          from tailscale.com/cmd/tailscaled+
         tailscale.com/portlist                                       from tailscale.com/ipn/ipnlocal
-        tailscale.com/safesocket                                     from tailscale.com/ipn/ipnserver+
+        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+
+   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/tstime/mono                                    from tailscale.com/net/tstun+
-        tailscale.com/tstime/rate                                    from tailscale.com/wgengine/filter
-        tailscale.com/types/dnstype                                  from tailscale.com/ipn/ipnlocal+
         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+
@@ -147,17 +126,15 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         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/pad32                                    from tailscale.com/net/tstun+
         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/types/wgkey                                    from tailscale.com/control/controlclient+
    L    tailscale.com/util/cmpver                                    from tailscale.com/net/dns
-     💣 tailscale.com/util/deephash                                  from tailscale.com/ipn/ipnlocal+
         tailscale.com/util/dnsname                                   from tailscale.com/ipn/ipnstate+
   LW    tailscale.com/util/endian                                    from tailscale.com/net/netns+
-        tailscale.com/util/groupmember                               from tailscale.com/ipn/ipnserver
-        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+   L    tailscale.com/util/lineread                                  from tailscale.com/control/controlclient+
         tailscale.com/util/osshare                                   from tailscale.com/cmd/tailscaled+
         tailscale.com/util/pidowner                                  from tailscale.com/ipn/ipnserver
         tailscale.com/util/racebuild                                 from tailscale.com/logpolicy
@@ -165,21 +142,19 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/util/uniq                                      from tailscale.com/wgengine/magicsock
         tailscale.com/util/winutil                                   from tailscale.com/logpolicy+
         tailscale.com/version                                        from tailscale.com/cmd/tailscaled+
-        tailscale.com/version/distro                                 from tailscale.com/cmd/tailscaled+
-   W    tailscale.com/wf                                             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/wgengine+
         tailscale.com/wgengine/monitor                               from tailscale.com/wgengine+
-        tailscale.com/wgengine/netstack                              from tailscale.com/cmd/tailscaled+
+        tailscale.com/wgengine/netstack                              from tailscale.com/cmd/tailscaled
         tailscale.com/wgengine/router                                from tailscale.com/cmd/tailscaled+
         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/acme                                     from tailscale.com/ipn/localapi
         golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box
-        golang.org/x/crypto/blake2s                                  from golang.zx2c4.com/wireguard/device+
+        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+
@@ -188,7 +163,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         golang.org/x/crypto/hkdf                                     from crypto/tls
         golang.org/x/crypto/nacl/box                                 from tailscale.com/control/controlclient+
         golang.org/x/crypto/nacl/secretbox                           from golang.org/x/crypto/nacl/box
-        golang.org/x/crypto/poly1305                                 from golang.org/x/crypto/chacha20poly1305+
+        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/net/bpf                                         from github.com/mdlayher/netlink+
         golang.org/x/net/dns/dnsmessage                              from net+
@@ -196,15 +171,15 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         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 golang.zx2c4.com/wireguard/device
-        golang.org/x/net/ipv6                                        from golang.zx2c4.com/wireguard/device+
+        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/sync/errgroup                                   from tailscale.com/derp+
+        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/mdlayher/netlink+
-   W    golang.org/x/sys/windows                                     from github.com/go-ole/go-ole+
+  LD    golang.org/x/sys/unix                                        from github.com/jsimonetti/rtnetlink/internal/unix+
+   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+
    W    golang.org/x/sys/windows/svc/mgr                             from tailscale.com/cmd/tailscaled
@@ -216,8 +191,9 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         golang.org/x/time/rate                                       from inet.af/netstack/tcpip/stack+
         bufio                                                        from compress/flate+
         bytes                                                        from bufio+
-        compress/flate                                               from compress/gzip
+        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+
@@ -241,7 +217,11 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         crypto/tls                                                   from github.com/tcnksm/go-httpstat+
         crypto/x509                                                  from crypto/tls+
         crypto/x509/pkix                                             from crypto/x509+
-        embed                                                        from tailscale.com/net/dns+
+        debug/dwarf                                                  from debug/elf+
+        debug/elf                                                    from rsc.io/goversion/version
+        debug/macho                                                  from rsc.io/goversion/version
+        debug/pe                                                     from rsc.io/goversion/version
+   L    embed                                                        from tailscale.com/net/dns
         encoding                                                     from encoding/json+
         encoding/asn1                                                from crypto/x509+
         encoding/base64                                              from encoding/json+
@@ -249,12 +229,12 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         encoding/hex                                                 from crypto/x509+
         encoding/json                                                from expvar+
         encoding/pem                                                 from crypto/tls+
-        encoding/xml                                                 from github.com/tailscale/goupnp+
         errors                                                       from bufio+
         expvar                                                       from tailscale.com/derp+
         flag                                                         from tailscale.com/cmd/tailscaled+
         fmt                                                          from compress/flate+
-        hash                                                         from crypto+
+        hash                                                         from compress/zlib+
+        hash/adler32                                                 from compress/zlib
         hash/crc32                                                   from compress/gzip+
         hash/fnv                                                     from tailscale.com/wgengine/magicsock+
         hash/maphash                                                 from go4.org/mem
@@ -282,7 +262,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         os/exec                                                      from github.com/coreos/go-iptables/iptables+
         os/signal                                                    from tailscale.com/cmd/tailscaled+
         os/user                                                      from github.com/godbus/dbus/v5+
-        path                                                         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+

cmd/tailscaled/main.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"os"
+	"strings"
+)
+
+func main() {
+	if strings.HasSuffix(os.Args[0], "tailscaled") {
+		tailscaled_main()
+	} else if strings.HasSuffix(os.Args[0], "tailscale") {
+		tailscale_main()
+	} else {
+		panic(os.Args[0])
+	}
+}

cmd/tailscaled/tailscale.go

@@ -4,7 +4,7 @@
 
 // The tailscale command is the Tailscale command-line client. It interacts
 // with the tailscaled node agent.
-package main // import "tailscale.com/cmd/tailscale"
+package main // import "tailscale.com/cmd/tailscaled"
 
 import (
 	"fmt"
@@ -12,10 +12,10 @@ import (
 	"path/filepath"
 	"strings"
 
-	"tailscale.com/cmd/tailscale/cli"
+	"tailscale.com/cmd/tailscaled/cli"
 )
 
-func main() {
+func tailscale_main() {
 	args := os.Args[1:]
 	if name, _ := os.Executable(); strings.HasSuffix(filepath.Base(name), ".cgi") {
 		args = []string{"web", "-cgi"}

cmd/tailscaled/tailscaled.go

@@ -19,24 +19,27 @@ import (
 	"net/http"
 	"net/http/pprof"
 	"os"
-	"os/exec"
 	"os/signal"
 	"runtime"
 	"runtime/debug"
 	"strconv"
 	"strings"
+	"sync"
 	"syscall"
 	"time"
 
 	"github.com/go-multierror/multierror"
-	"tailscale.com/ipn"
+	"inet.af/netaddr"
 	"tailscale.com/ipn/ipnserver"
 	"tailscale.com/logpolicy"
 	"tailscale.com/net/dns"
-	"tailscale.com/net/socks5/tssocks"
+	"tailscale.com/net/socks5"
+	"tailscale.com/net/tsaddr"
+	"tailscale.com/net/tstun"
 	"tailscale.com/paths"
 	"tailscale.com/types/flagtype"
 	"tailscale.com/types/logger"
+	"tailscale.com/types/netmap"
 	"tailscale.com/util/osshare"
 	"tailscale.com/version"
 	"tailscale.com/version/distro"
@@ -46,6 +49,15 @@ import (
 	"tailscale.com/wgengine/router"
 )
 
+// globalStateKey is the ipn.StateKey that tailscaled loads on
+// startup.
+//
+// We have to support multiple state keys for other OSes (Windows in
+// particular), but right now Unix daemons run with a single
+// node-global state. To keep open the option of having per-user state
+// later, the global state key doesn't look like a username.
+const globalStateKey = "_daemon"
+
 // defaultTunName returns the default tun device name for the platform.
 func defaultTunName() string {
 	switch runtime.GOOS {
@@ -68,13 +80,9 @@ func defaultTunName() string {
 }
 
 var args struct {
-	// tunname is a /dev/net/tun tunnel name ("tailscale0"), the
-	// string "userspace-networking", "tap:TAPNAME[:BRIDGENAME]"
-	// or comma-separated list thereof.
-	tunname string
-
 	cleanup    bool
 	debug      string
+	tunname    string // tun name, "userspace-networking", or comma-separated list thereof
 	port       uint16
 	statepath  string
 	socketpath string
@@ -93,7 +101,7 @@ var subCommands = map[string]*func([]string) error{
 	"debug":                   &debugModeFunc,
 }
 
-func main() {
+func tailscaled_main() {
 	// We aren't very performance sensitive, and the parts that are
 	// performance sensitive (wireguard) try hard not to do any memory
 	// allocations. So let's be aggressive about garbage collection,
@@ -142,7 +150,7 @@ func main() {
 		os.Exit(0)
 	}
 
-	if runtime.GOOS == "darwin" && os.Getuid() != 0 && !strings.Contains(args.tunname, "userspace-networking") && !args.cleanup {
+	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)")
 	}
@@ -163,56 +171,6 @@ func main() {
 	}
 }
 
-func trySynologyMigration(p string) error {
-	if runtime.GOOS != "linux" || distro.Get() != distro.Synology {
-		return nil
-	}
-
-	fi, err := os.Stat(p)
-	if err == nil && fi.Size() > 0 || !os.IsNotExist(err) {
-		return err
-	}
-	// File is empty or doesn't exist, try reading from the old path.
-
-	const oldPath = "/var/packages/Tailscale/etc/tailscaled.state"
-	if _, err := os.Stat(oldPath); err != nil {
-		if os.IsNotExist(err) {
-			return nil
-		}
-		return err
-	}
-
-	if err := os.Chown(oldPath, os.Getuid(), os.Getgid()); err != nil {
-		return err
-	}
-	if err := os.Rename(oldPath, p); err != nil {
-		return err
-	}
-	return nil
-}
-
-func ipnServerOpts() (o ipnserver.Options) {
-	// Allow changing the OS-specific IPN behavior for tests
-	// so we can e.g. test Windows-specific behaviors on Linux.
-	goos := os.Getenv("TS_DEBUG_TAILSCALED_IPN_GOOS")
-	if goos == "" {
-		goos = runtime.GOOS
-	}
-
-	o.Port = 41112
-	o.StatePath = args.statepath
-	o.SocketPath = args.socketpath // even for goos=="windows", for tests
-
-	switch goos {
-	default:
-		o.SurviveDisconnects = true
-		o.AutostartStateKey = ipn.GlobalDaemonStateKey
-	case "windows":
-		// Not those.
-	}
-	return o
-}
-
 func run() error {
 	var err error
 
@@ -242,9 +200,6 @@ func run() error {
 	logf = logger.RateLimitedFn(logf, 5*time.Second, 5, 100)
 
 	if args.cleanup {
-		if os.Getenv("TS_PLEASE_PANIC") != "" {
-			panic("TS_PLEASE_PANIC asked us to panic")
-		}
 		dns.Cleanup(logf, args.tunname)
 		router.Cleanup(logf, args.tunname)
 		return nil
@@ -253,9 +208,6 @@ func run() error {
 	if args.statepath == "" {
 		log.Fatalf("--state is required")
 	}
-	if err := trySynologyMigration(args.statepath); err != nil {
-		log.Printf("error in synology migration: %v", err)
-	}
 
 	var debugMux *http.ServeMux
 	if args.debug != "" {
@@ -276,11 +228,6 @@ func run() error {
 		if err != nil {
 			log.Fatalf("SOCKS5 listener: %v", err)
 		}
-		if strings.HasSuffix(args.socksAddr, ":0") {
-			// Log kernel-selected port number so integration tests
-			// can find it portably.
-			log.Printf("SOCKS5 listening on %v", socksListener.Addr())
-		}
 	}
 
 	e, useNetstack, err := createEngine(logf, linkMon)
@@ -296,7 +243,35 @@ func run() error {
 	}
 
 	if socksListener != nil {
-		srv := tssocks.NewServer(logger.WithPrefix(logf, "socks5: "), e, ns)
+		srv := &socks5.Server{
+			Logf: logger.WithPrefix(logf, "socks5: "),
+		}
+		var (
+			mu  sync.Mutex // guards the following field
+			dns netstack.DNSMap
+		)
+		e.AddNetworkMapCallback(func(nm *netmap.NetworkMap) {
+			mu.Lock()
+			defer mu.Unlock()
+			dns = netstack.DNSMapFromNetworkMap(nm)
+		})
+		useNetstackForIP := func(ip netaddr.IP) bool {
+			// TODO(bradfitz): this isn't exactly right.
+			// We should also support subnets when the
+			// prefs are configured as such.
+			return tsaddr.IsTailscaleIP(ip)
+		}
+		srv.Dialer = func(ctx context.Context, network, addr string) (net.Conn, error) {
+			ipp, err := dns.Resolve(ctx, addr)
+			if err != nil {
+				return nil, err
+			}
+			if ns != nil && useNetstackForIP(ipp.IP()) {
+				return ns.DialContextTCP(ctx, addr)
+			}
+			var d net.Dialer
+			return d.DialContext(ctx, network, ipp.String())
+		}
 		go func() {
 			log.Fatalf("SOCKS5 server exited: %v", srv.Serve(socksListener))
 		}()
@@ -323,8 +298,14 @@ func run() error {
 		}
 	}()
 
-	opts := ipnServerOpts()
-	opts.DebugMux = debugMux
+	opts := ipnserver.Options{
+		SocketPath:         args.socketpath,
+		Port:               41112,
+		StatePath:          args.statepath,
+		AutostartStateKey:  globalStateKey,
+		SurviveDisconnects: runtime.GOOS != "windows",
+		DebugMux:           debugMux,
+	}
 	err = ipnserver.Run(ctx, logf, pol.PublicID.String(), ipnserver.FixedEngine(e), opts)
 	// Cancelation is not an error: it is the only way to stop ipnserver.
 	if err != nil && err != context.Canceled {
@@ -366,9 +347,9 @@ func shouldWrapNetstack() bool {
 		return true
 	}
 	switch runtime.GOOS {
-	case "windows", "darwin", "freebsd":
+	case "windows", "darwin":
 		// Enable on Windows and tailscaled-on-macOS (this doesn't
-		// affect the GUI clients), and on FreeBSD.
+		// affect the GUI clients).
 		return true
 	}
 	return false
@@ -381,33 +362,18 @@ func tryEngine(logf logger.Logf, linkMon *monitor.Mon, name string) (e wgengine.
 	}
 	useNetstack = name == "userspace-networking"
 	if !useNetstack {
-		// dev, devName, err := tstun.New(logf, name)
-		// if err != nil {
-		// 	tstun.Diagnose(logf, name)
-		// 	return nil, false, err
-		// }
-		// conf.Tun = dev
-		// if strings.HasPrefix(name, "tap:") {
-		// 	conf.IsTAP = true
-		// 	e, err := wgengine.NewUserspaceEngine(logf, conf)
-		// 	return e, false, err
-		// }
-
-		// HACK
-		exec.Command("ip", "link", "del", "tailscale0").Run()
-		if err := exec.Command("ip", "link", "add", "tailscale0", "type", "wireguard").Run(); err != nil {
-			return nil, false, fmt.Errorf("create device: %v", err)
-		}
-		if err := exec.Command("ip", "link", "set", "tailscale0", "up").Run(); err != nil {
-			return nil, false, fmt.Errorf("create device: %v", err)
-		}
-
-		r, err := router.New(logf, nil, linkMon)
+		dev, devName, err := tstun.New(logf, name)
 		if err != nil {
-			//dev.Close()
+			tstun.Diagnose(logf, name)
 			return nil, false, err
 		}
-		d, err := dns.NewOSConfigurator(logf, "tailscale0")
+		conf.Tun = dev
+		r, err := router.New(logf, dev)
+		if err != nil {
+			dev.Close()
+			return nil, false, err
+		}
+		d, err := dns.NewOSConfigurator(logf, devName)
 		if err != nil {
 			return nil, false, err
 		}
@@ -417,7 +383,7 @@ func tryEngine(logf logger.Logf, linkMon *monitor.Mon, name string) (e wgengine.
 			conf.Router = netstack.NewSubnetRouterWrapper(conf.Router)
 		}
 	}
-	e, err = wgengine.NewKernelEngine(logf, conf)
+	e, err = wgengine.NewUserspaceEngine(logf, conf)
 	if err != nil {
 		return nil, useNetstack, err
 	}

cmd/tailscaled/tailscaled.openrc

@@ -1,25 +0,0 @@
-#!/sbin/openrc-run
-
-set -a
-source /etc/default/tailscaled
-set +a
-
-command="/usr/sbin/tailscaled"
-command_args="--state=/var/lib/tailscale/tailscaled.state --port=$PORT --socket=/var/run/tailscale/tailscaled.sock $FLAGS"
-command_background=true
-pidfile="/run/tailscaled.pid"
-start_stop_daemon_args="-1 /var/log/tailscaled.log -2 /var/log/tailscaled.log"
-
-depend() {
-    need net
-}
-
-start_pre() {
-    mkdir -p /var/run/tailscale
-    mkdir -p /var/lib/tailscale
-    $command --cleanup
-}
-
-stop_post() {
-    $command --cleanup
-}

cmd/tailscaled/tailscaled.service

@@ -2,7 +2,7 @@
 Description=Tailscale node agent
 Documentation=https://tailscale.com/kb/
 Wants=network-pre.target
-After=network-pre.target NetworkManager.service systemd-resolved.service
+After=network-pre.target
 
 [Service]
 EnvironmentFile=/etc/default/tailscaled

cmd/tailscaled/tailscaled_notwindows.go

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
 // +build !windows
 
 package main // import "tailscale.com/cmd/tailscaled"

cmd/tailscaled/tailscaled_windows.go

@@ -19,23 +19,22 @@ package main // import "tailscale.com/cmd/tailscaled"
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"log"
+	"net"
 	"os"
 	"time"
 
 	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/svc"
 	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
-	"inet.af/netaddr"
 	"tailscale.com/ipn/ipnserver"
 	"tailscale.com/logpolicy"
 	"tailscale.com/net/dns"
 	"tailscale.com/net/tstun"
+	"tailscale.com/tempfork/wireguard-windows/firewall"
 	"tailscale.com/types/logger"
 	"tailscale.com/version"
-	"tailscale.com/wf"
 	"tailscale.com/wgengine"
 	"tailscale.com/wgengine/netstack"
 	"tailscale.com/wgengine/router"
@@ -128,6 +127,16 @@ func beFirewallKillswitch() bool {
 	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)
@@ -135,29 +144,17 @@ func beFirewallKillswitch() bool {
 
 	luid, err := winipcfg.LUIDFromGUID(&guid)
 	if err != nil {
-		log.Fatalf("no interface with GUID %q: %v", guid, err)
+		log.Fatalf("no interface with GUID %q", guid)
 	}
 
+	noProtection := false
+	var dnsIPs []net.IP // unused in called code.
 	start := time.Now()
-	fw, err := wf.New(uint64(luid))
-	if err != nil {
-		log.Fatalf("failed to enable firewall: %v", err)
-	}
+	firewall.EnableFirewall(uint64(luid), noProtection, dnsIPs)
 	log.Printf("killswitch enabled, took %s", time.Since(start))
 
-	// Note(maisem): when local lan access toggled, tailscaled needs to
-	// inform the firewall to let local routes through. The set of routes
-	// is passed in via stdin encoded in json.
-	dcd := json.NewDecoder(os.Stdin)
-	for {
-		var routes []netaddr.IPPrefix
-		if err := dcd.Decode(&routes); err != nil {
-			log.Fatalf("parent process died or requested exit, exiting (%v)", err)
-		}
-		if err := fw.UpdatePermittedRoutes(routes); err != nil {
-			log.Fatalf("failed to update routes (%v)", err)
-		}
-	}
+	// Block until the monitor goroutine shuts us down.
+	select {}
 }
 
 func startIPNServer(ctx context.Context, logid string) error {
@@ -168,7 +165,7 @@ func startIPNServer(ctx context.Context, logid string) error {
 		if err != nil {
 			return nil, fmt.Errorf("TUN: %w", err)
 		}
-		r, err := router.New(logf, dev, nil)
+		r, err := router.New(logf, dev)
 		if err != nil {
 			dev.Close()
 			return nil, fmt.Errorf("router: %w", err)
@@ -233,6 +230,12 @@ func startIPNServer(ctx context.Context, logid string) error {
 		}
 	}()
 
+	opts := ipnserver.Options{
+		Port:               41112,
+		SurviveDisconnects: false,
+		StatePath:          args.statepath,
+	}
+
 	// getEngine is called by ipnserver to get the engine. It's
 	// not called concurrently and is not called again once it
 	// successfully returns an engine.
@@ -257,7 +260,7 @@ func startIPNServer(ctx context.Context, logid string) error {
 			return nil, fmt.Errorf("%w\n\nlogid: %v", res.Err, logid)
 		}
 	}
-	err := ipnserver.Run(ctx, logf, logid, getEngine, ipnServerOpts())
+	err := ipnserver.Run(ctx, logf, logid, getEngine, opts)
 	if err != nil {
 		logf("ipnserver.Run: %v", err)
 	}

cmd/testcontrol/testcontrol.go

@@ -1,98 +0,0 @@
-// 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.
-
-// Program testcontrol runs a simple test control server.
-package main
-
-import (
-	"flag"
-	"log"
-	"net/http"
-	"testing"
-
-	"tailscale.com/tstest/integration"
-	"tailscale.com/tstest/integration/testcontrol"
-	"tailscale.com/types/logger"
-)
-
-var (
-	flagNFake = flag.Int("nfake", 0, "number of fake nodes to add to network")
-)
-
-func main() {
-	flag.Parse()
-
-	var t fakeTB
-	derpMap := integration.RunDERPAndSTUN(t, logger.Discard, "127.0.0.1")
-
-	control := &testcontrol.Server{
-		DERPMap:         derpMap,
-		ExplicitBaseURL: "http://127.0.0.1:9911",
-	}
-	for i := 0; i < *flagNFake; i++ {
-		control.AddFakeNode()
-	}
-	mux := http.NewServeMux()
-	mux.Handle("/", control)
-	addr := "127.0.0.1:9911"
-	log.Printf("listening on %s", addr)
-	err := http.ListenAndServe(addr, mux)
-	log.Fatal(err)
-}
-
-type fakeTB struct {
-	*testing.T
-}
-
-func (t fakeTB) Cleanup(_ func()) {}
-func (t fakeTB) Error(args ...interface{}) {
-	t.Fatal(args...)
-}
-func (t fakeTB) Errorf(format string, args ...interface{}) {
-	t.Fatalf(format, args...)
-}
-func (t fakeTB) Fail() {
-	t.Fatal("failed")
-}
-func (t fakeTB) FailNow() {
-	t.Fatal("failed")
-}
-func (t fakeTB) Failed() bool {
-	return false
-}
-func (t fakeTB) Fatal(args ...interface{}) {
-	log.Fatal(args...)
-}
-func (t fakeTB) Fatalf(format string, args ...interface{}) {
-	log.Fatalf(format, args...)
-}
-func (t fakeTB) Helper() {}
-func (t fakeTB) Log(args ...interface{}) {
-	log.Print(args...)
-}
-func (t fakeTB) Logf(format string, args ...interface{}) {
-	log.Printf(format, args...)
-}
-func (t fakeTB) Name() string {
-	return "faketest"
-}
-func (t fakeTB) Setenv(key string, value string) {
-	panic("not implemented")
-}
-func (t fakeTB) Skip(args ...interface{}) {
-	t.Fatal("skipped")
-}
-func (t fakeTB) SkipNow() {
-	t.Fatal("skipnow")
-}
-func (t fakeTB) Skipf(format string, args ...interface{}) {
-	t.Logf(format, args...)
-	t.Fatal("skipped")
-}
-func (t fakeTB) Skipped() bool {
-	return false
-}
-func (t fakeTB) TempDir() string {
-	panic("not implemented")
-}

cmd/tsshd/tsshd.go

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
 // +build !windows
 
 // The tsshd binary is an SSH server that accepts connections
@@ -30,8 +29,8 @@ import (
 	"time"
 	"unsafe"
 
-	"github.com/creack/pty"
 	"github.com/gliderlabs/ssh"
+	"github.com/kr/pty"
 	gossh "golang.org/x/crypto/ssh"
 	"inet.af/netaddr"
 	"tailscale.com/net/interfaces"

cmd/tsshd/tsshd_windows.go

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build windows
 // +build windows
 
 package main

control/controlclient/auto.go

@@ -576,12 +576,9 @@ func (c *Auto) sendStatus(who string, err error, url string, nm *netmap.NetworkM
 	c.logf("[v1] sendStatus: %s: %v", who, state)
 
 	var p *persist.Persist
-	var loginFin, logoutFin *empty.Message
+	var fin *empty.Message
 	if state == StateAuthenticated {
-		loginFin = new(empty.Message)
-	}
-	if state == StateNotAuthenticated {
-		logoutFin = new(empty.Message)
+		fin = new(empty.Message)
 	}
 	if nm != nil && loggedIn && synced {
 		pp := c.direct.GetPersist()
@@ -592,13 +589,12 @@ func (c *Auto) sendStatus(who string, err error, url string, nm *netmap.NetworkM
 		nm = nil
 	}
 	new := Status{
-		LoginFinished:  loginFin,
-		LogoutFinished: logoutFin,
-		URL:            url,
-		Persist:        p,
-		NetMap:         nm,
-		Hostinfo:       hi,
-		State:          state,
+		LoginFinished: fin,
+		URL:           url,
+		Persist:       p,
+		NetMap:        nm,
+		Hostinfo:      hi,
+		State:         state,
 	}
 	if err != nil {
 		new.Err = err.Error()
@@ -716,9 +712,3 @@ func (c *Auto) TestOnlySetAuthKey(authkey string) {
 func (c *Auto) TestOnlyTimeNow() time.Time {
 	return c.timeNow()
 }
-
-// SetDNS sends the SetDNSRequest request to the control plane server,
-// requesting a DNS record be created or updated.
-func (c *Auto) SetDNS(ctx context.Context, req *tailcfg.SetDNSRequest) error {
-	return c.direct.SetDNS(ctx, req)
-}

control/controlclient/client.go

@@ -74,7 +74,4 @@ type Client interface {
 	// in a separate http request. It has nothing to do with the rest of
 	// the state machine.
 	UpdateEndpoints(localPort uint16, endpoints []tailcfg.Endpoint)
-	// SetDNS sends the SetDNSRequest request to the control plane server,
-	// requesting a DNS record be created or updated.
-	SetDNS(context.Context, *tailcfg.SetDNSRequest) error
 }

control/controlclient/controlclient_test.go

@@ -22,7 +22,7 @@ func fieldsOf(t reflect.Type) (fields []string) {
 
 func TestStatusEqual(t *testing.T) {
 	// Verify that the Equal method stays in sync with reality
-	equalHandles := []string{"LoginFinished", "LogoutFinished", "Err", "URL", "NetMap", "State", "Persist", "Hostinfo"}
+	equalHandles := []string{"LoginFinished", "Err", "URL", "NetMap", "State", "Persist", "Hostinfo"}
 	if have := fieldsOf(reflect.TypeOf(Status{})); !reflect.DeepEqual(have, equalHandles) {
 		t.Errorf("Status.Equal check might be out of sync\nfields: %q\nhandled: %q\n",
 			have, equalHandles)
@@ -75,3 +75,10 @@ func TestStatusEqual(t *testing.T) {
 		}
 	}
 }
+
+func TestOSVersion(t *testing.T) {
+	if osVersion == nil {
+		t.Skip("not available for OS")
+	}
+	t.Logf("Got: %#q", osVersion())
+}

control/controlclient/debug.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"regexp"
 	"runtime"
 	"strconv"
 	"time"
@@ -41,82 +42,28 @@ func dumpGoroutinesToURL(c *http.Client, targetURL string) {
 	}
 }
 
+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 {
-	var buf []byte
-	// Grab stacks multiple times into increasingly larger buffer sizes
-	// to minimize the risk that we blow past our iOS memory limit.
-	for size := 1 << 10; size <= 1<<20; size += 1 << 10 {
-		buf = make([]byte, size)
-		buf = buf[:runtime.Stack(buf, true)]
-		if len(buf) < size {
-			// It fit.
-			break
-		}
-	}
-	return scrubHex(buf)
-}
+	buf := make([]byte, 1<<20)
+	buf = buf[:runtime.Stack(buf, true)]
 
-func scrubHex(buf []byte) []byte {
 	saw := map[string][]byte{} // "0x123" => "v1%3" (unique value 1 and its value mod 8)
-
-	foreachHexAddress(buf, func(in []byte) {
+	return reHexArgs.ReplaceAllFunc(buf, func(in []byte) []byte {
 		if string(in) == "0x0" {
-			return
+			return in
 		}
 		if v, ok := saw[string(in)]; ok {
-			for i := range in {
-				in[i] = '_'
-			}
-			copy(in, v)
-			return
+			return v
 		}
-		inStr := string(in)
 		u64, err := strconv.ParseUint(string(in[2:]), 16, 64)
-		for i := range in {
-			in[i] = '_'
-		}
 		if err != nil {
-			in[0] = '?'
-			return
+			return []byte("??")
 		}
 		v := []byte(fmt.Sprintf("v%d%%%d", len(saw)+1, u64%8))
-		saw[inStr] = v
-		copy(in, v)
+		saw[string(in)] = v
+		return v
 	})
-	return buf
-}
-
-var ohx = []byte("0x")
-
-// foreachHexAddress calls f with each subslice of b that matches
-// regexp `0x[0-9a-f]*`.
-func foreachHexAddress(b []byte, f func([]byte)) {
-	for len(b) > 0 {
-		i := bytes.Index(b, ohx)
-		if i == -1 {
-			return
-		}
-		b = b[i:]
-		hx := hexPrefix(b)
-		f(hx)
-		b = b[len(hx):]
-	}
-}
-
-func hexPrefix(b []byte) []byte {
-	for i, c := range b {
-		if i < 2 {
-			continue
-		}
-		if !isHexByte(c) {
-			return b[:i]
-		}
-	}
-	return b
-}
-
-func isHexByte(b byte) bool {
-	return '0' <= b && b <= '9' || 'a' <= b && b <= 'f' || 'A' <= b && b <= 'F'
 }

control/controlclient/debug_test.go

@@ -9,22 +9,3 @@ import "testing"
 func TestScrubbedGoroutineDump(t *testing.T) {
 	t.Logf("Got:\n%s\n", scrubbedGoroutineDump())
 }
-
-func TestScrubHex(t *testing.T) {
-	tests := []struct {
-		in, want string
-	}{
-		{"foo", "foo"},
-		{"", ""},
-		{"0x", "?_"},
-		{"0x001 and same 0x001", "v1%1_ and same v1%1_"},
-		{"0x008 and same 0x008", "v1%0_ and same v1%0_"},
-		{"0x001 and diff 0x002", "v1%1_ and diff v2%2_"},
-	}
-	for _, tt := range tests {
-		got := scrubHex([]byte(tt.in))
-		if string(got) != tt.want {
-			t.Errorf("for input:\n%s\n\ngot:\n%s\n\nwant:\n%s\n", tt.in, got, tt.want)
-		}
-	}
-}

control/controlclient/direct.go

@@ -20,6 +20,7 @@ import (
 	"net/url"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"reflect"
 	"runtime"
 	"strconv"
@@ -30,10 +31,7 @@ import (
 
 	"golang.org/x/crypto/nacl/box"
 	"inet.af/netaddr"
-	"tailscale.com/control/controlknobs"
 	"tailscale.com/health"
-	"tailscale.com/hostinfo"
-	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/log/logheap"
 	"tailscale.com/net/dnscache"
 	"tailscale.com/net/dnsfallback"
@@ -47,7 +45,9 @@ import (
 	"tailscale.com/types/opt"
 	"tailscale.com/types/persist"
 	"tailscale.com/types/wgkey"
+	"tailscale.com/util/dnsname"
 	"tailscale.com/util/systemd"
+	"tailscale.com/version"
 	"tailscale.com/wgengine/monitor"
 )
 
@@ -66,7 +66,6 @@ type Direct struct {
 	debugFlags             []string
 	keepSharerAndUserSplit bool
 	skipIPForwardingCheck  bool
-	pinger                 Pinger
 
 	mu           sync.Mutex // mutex guards the following fields
 	serverKey    wgkey.Key
@@ -79,7 +78,6 @@ type Direct struct {
 	endpoints     []tailcfg.Endpoint
 	everEndpoints bool   // whether we've ever had non-empty endpoints
 	localPort     uint16 // or zero to mean auto
-	lastPingURL   string // last PingRequest.URL received, for dup suppresion
 }
 
 type Options struct {
@@ -105,18 +103,6 @@ type Options struct {
 	// forwarding works and should not be double-checked by the
 	// controlclient package.
 	SkipIPForwardingCheck bool
-
-	// Pinger optionally specifies the Pinger to use to satisfy
-	// MapResponse.PingRequest queries from the control plane.
-	// If nil, PingRequest queries are not answered.
-	Pinger Pinger
-}
-
-// Pinger is a subset of the wgengine.Engine interface, containing just the Ping method.
-type Pinger interface {
-	// Ping is a request to start a discovery or TSMP ping with the peer handling
-	// the given IP and then call cb with its ping latency & method.
-	Ping(ip netaddr.IP, useTSMP bool, cb func(*ipnstate.PingResult))
 }
 
 type Decompressor interface {
@@ -179,16 +165,48 @@ func NewDirect(opts Options) (*Direct, error) {
 		keepSharerAndUserSplit: opts.KeepSharerAndUserSplit,
 		linkMon:                opts.LinkMonitor,
 		skipIPForwardingCheck:  opts.SkipIPForwardingCheck,
-		pinger:                 opts.Pinger,
 	}
 	if opts.Hostinfo == nil {
-		c.SetHostinfo(hostinfo.New())
+		c.SetHostinfo(NewHostinfo())
 	} else {
 		c.SetHostinfo(opts.Hostinfo)
 	}
 	return c, nil
 }
 
+var osVersion func() string // non-nil on some platforms
+
+func NewHostinfo() *tailcfg.Hostinfo {
+	hostname, _ := os.Hostname()
+	hostname = dnsname.FirstLabel(hostname)
+	var osv string
+	if osVersion != nil {
+		osv = osVersion()
+	}
+	return &tailcfg.Hostinfo{
+		IPNVersion: version.Long,
+		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 {
@@ -320,7 +338,6 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 		if err != nil {
 			return regen, opt.URL, err
 		}
-		c.logf("control server key %s from %s", serverKey.HexString(), c.serverURL)
 
 		c.mu.Lock()
 		c.serverKey = serverKey
@@ -743,7 +760,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*netm
 			health.GotStreamedMapResponse()
 		}
 
-		if pr := resp.PingRequest; pr != nil && c.isUniquePingRequest(pr) {
+		if pr := resp.PingRequest; pr != nil {
 			go answerPing(c.logf, c.httpc, pr)
 		}
 
@@ -763,10 +780,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*netm
 			continue
 		}
 
-		hasDebug := resp.Debug != nil
-		// being conservative here, if Debug not present set to False
-		controlknobs.SetDisableUPnP(hasDebug && resp.Debug.DisableUPnP.EqualBool(true))
-		if hasDebug {
+		if resp.Debug != nil {
 			if resp.Debug.LogHeapPprof {
 				go logheap.LogHeap(resp.Debug.LogHeapURL)
 			}
@@ -823,21 +837,22 @@ func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*netm
 		}
 
 		// Get latest localPort. This might've changed if
-		// a lite map update occurred meanwhile. This only affects
+		// 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()
 		nm.LocalPort = c.localPort
 		c.mu.Unlock()
 
-		// Occasionally print the netmap header.
-		// This is handy for debugging, and our logs processing
-		// pipeline depends on it. (TODO: Remove this dependency.)
-		// Code elsewhere prints netmap diffs every time they are received.
+		// Printing the netmap can be extremely verbose, but is very
+		// handy for debugging. Let's limit how often we do it.
+		// Code elsewhere prints netmap diffs every time, so this
+		// occasional full dump, plus incremental diffs, should do
+		// the job.
 		now := c.timeNow()
 		if now.Sub(c.lastPrintMap) >= 5*time.Minute {
 			c.lastPrintMap = now
-			c.logf("[v1] new network map[%d]:\n%s", i, nm.VeryConcise())
+			c.logf("[v1] new network map[%d]:\n%s", i, nm.Concise())
 		}
 
 		c.mu.Lock()
@@ -1140,23 +1155,6 @@ func ipForwardingBroken(routes []netaddr.IPPrefix, state *interfaces.State) bool
 	return false
 }
 
-// isUniquePingRequest reports whether pr contains a new PingRequest.URL
-// not already handled, noting its value when returning true.
-func (c *Direct) isUniquePingRequest(pr *tailcfg.PingRequest) bool {
-	if pr == nil || pr.URL == "" {
-		// Bogus.
-		return false
-	}
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	if pr.URL == c.lastPingURL {
-		return false
-	}
-	c.lastPingURL = pr.URL
-	return true
-}
-
 func answerPing(logf logger.Logf, c *http.Client, pr *tailcfg.PingRequest) {
 	if pr.URL == "" {
 		logf("invalid PingRequest with no URL")
@@ -1213,106 +1211,3 @@ func sleepAsRequested(ctx context.Context, logf logger.Logf, timeoutReset chan<-
 		}
 	}
 }
-
-// SetDNS sends the SetDNSRequest request to the control plane server,
-// requesting a DNS record be created or updated.
-func (c *Direct) SetDNS(ctx context.Context, req *tailcfg.SetDNSRequest) error {
-	c.mu.Lock()
-	serverKey := c.serverKey
-	c.mu.Unlock()
-
-	if serverKey.IsZero() {
-		return errors.New("zero serverKey")
-	}
-	machinePrivKey, err := c.getMachinePrivKey()
-	if err != nil {
-		return fmt.Errorf("getMachinePrivKey: %w", err)
-	}
-	if machinePrivKey.IsZero() {
-		return errors.New("getMachinePrivKey returned zero key")
-	}
-
-	bodyData, err := encode(req, &serverKey, &machinePrivKey)
-	if err != nil {
-		return err
-	}
-	body := bytes.NewReader(bodyData)
-
-	u := fmt.Sprintf("%s/machine/%s/set-dns", c.serverURL, machinePrivKey.Public().HexString())
-	hreq, err := http.NewRequestWithContext(ctx, "POST", u, body)
-	if err != nil {
-		return err
-	}
-	res, err := c.httpc.Do(hreq)
-	if err != nil {
-		return err
-	}
-	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		msg, _ := ioutil.ReadAll(res.Body)
-		return fmt.Errorf("set-dns response: %v, %.200s", res.Status, strings.TrimSpace(string(msg)))
-	}
-	var setDNSRes struct{} // no fields yet
-	if err := decode(res, &setDNSRes, &serverKey, &machinePrivKey); err != nil {
-		c.logf("error decoding SetDNSResponse with server key %s and machine key %s: %v", serverKey, machinePrivKey.Public(), err)
-		return fmt.Errorf("set-dns-response: %v", err)
-	}
-
-	return nil
-}
-
-// tsmpPing sends a Ping to pr.IP, and sends an http request back to pr.URL
-// with ping response data.
-func tsmpPing(logf logger.Logf, c *http.Client, pr *tailcfg.PingRequest, pinger Pinger) error {
-	var err error
-	if pr.URL == "" {
-		return errors.New("invalid PingRequest with no URL")
-	}
-	if pr.IP.IsZero() {
-		return errors.New("PingRequest without IP")
-	}
-	if !strings.Contains(pr.Types, "TSMP") {
-		return fmt.Errorf("PingRequest with no TSMP in Types, got %q", pr.Types)
-	}
-
-	now := time.Now()
-	pinger.Ping(pr.IP, true, func(res *ipnstate.PingResult) {
-		// Currently does not check for error since we just return if it fails.
-		err = postPingResult(now, logf, c, pr, res)
-	})
-	return err
-}
-
-func postPingResult(now time.Time, logf logger.Logf, c *http.Client, pr *tailcfg.PingRequest, res *ipnstate.PingResult) error {
-	if res.Err != "" {
-		return errors.New(res.Err)
-	}
-	duration := time.Since(now)
-	if pr.Log {
-		logf("TSMP ping to %v completed in %v seconds. pinger.Ping took %v seconds", pr.IP, res.LatencySeconds, duration.Seconds())
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
-	defer cancel()
-
-	jsonPingRes, err := json.Marshal(res)
-	if err != nil {
-		return err
-	}
-	// Send the results of the Ping, back to control URL.
-	req, err := http.NewRequestWithContext(ctx, "POST", pr.URL, bytes.NewBuffer(jsonPingRes))
-	if err != nil {
-		return fmt.Errorf("http.NewRequestWithContext(%q): %w", pr.URL, err)
-	}
-	if pr.Log {
-		logf("tsmpPing: sending ping results to %v ...", pr.URL)
-	}
-	t0 := time.Now()
-	_, err = c.Do(req)
-	d := time.Since(t0).Round(time.Millisecond)
-	if err != nil {
-		return fmt.Errorf("tsmpPing error: %w to %v (after %v)", err, pr.URL, d)
-	} else if pr.Log {
-		logf("tsmpPing complete to %v (after %v)", pr.URL, d)
-	}
-	return nil
-}

control/controlclient/direct_test.go

@@ -6,20 +6,15 @@ package controlclient
 
 import (
 	"encoding/json"
-	"net/http"
-	"net/http/httptest"
 	"testing"
-	"time"
 
 	"inet.af/netaddr"
-	"tailscale.com/hostinfo"
-	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/wgkey"
 )
 
 func TestNewDirect(t *testing.T) {
-	hi := hostinfo.New()
+	hi := NewHostinfo()
 	ni := tailcfg.NetInfo{LinkType: "wired"}
 	hi.NetInfo = &ni
 
@@ -61,7 +56,7 @@ func TestNewDirect(t *testing.T) {
 	if changed {
 		t.Errorf("c.SetHostinfo(hi) want false got %v", changed)
 	}
-	hi = hostinfo.New()
+	hi = NewHostinfo()
 	hi.Hostname = "different host name"
 	changed = c.SetHostinfo(hi)
 	if !changed {
@@ -97,55 +92,14 @@ func fakeEndpoints(ports ...uint16) (ret []tailcfg.Endpoint) {
 	return
 }
 
-func TestTsmpPing(t *testing.T) {
-	hi := hostinfo.New()
-	ni := tailcfg.NetInfo{LinkType: "wired"}
-	hi.NetInfo = &ni
-
-	key, err := wgkey.NewPrivate()
-	if err != nil {
-		t.Error(err)
+func TestNewHostinfo(t *testing.T) {
+	hi := NewHostinfo()
+	if hi == nil {
+		t.Fatal("no Hostinfo")
 	}
-	opts := Options{
-		ServerURL: "https://example.com",
-		Hostinfo:  hi,
-		GetMachinePrivateKey: func() (wgkey.Private, error) {
-			return key, nil
-		},
-	}
-
-	c, err := NewDirect(opts)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	pingRes := &ipnstate.PingResult{
-		IP:       "123.456.7890",
-		Err:      "",
-		NodeName: "testnode",
-	}
-
-	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		defer r.Body.Close()
-		body := new(ipnstate.PingResult)
-		if err := json.NewDecoder(r.Body).Decode(body); err != nil {
-			t.Fatal(err)
-		}
-		if pingRes.IP != body.IP {
-			t.Fatalf("PingResult did not have the correct IP : got %v, expected : %v", body.IP, pingRes.IP)
-		}
-		w.WriteHeader(200)
-	}))
-	defer ts.Close()
-
-	now := time.Now()
-
-	pr := &tailcfg.PingRequest{
-		URL: ts.URL,
-	}
-
-	err = postPingResult(now, t.Logf, c.httpc, pr, pingRes)
+	j, err := json.MarshalIndent(hi, "  ", "")
 	if err != nil {
 		t.Fatal(err)
 	}
+	t.Logf("Got: %s", j)
 }

control/controlclient/hostinfo_linux.go

@@ -2,31 +2,26 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && !android
 // +build linux,!android
 
-package hostinfo
+package controlclient
 
 import (
 	"bytes"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 	"strings"
 	"syscall"
 
+	"go4.org/mem"
 	"tailscale.com/util/lineread"
 	"tailscale.com/version/distro"
 )
 
 func init() {
 	osVersion = osVersionLinux
-
-	if v, _ := os.ReadFile("/sys/firmware/devicetree/base/model"); len(v) > 0 {
-		// Look up "Raspberry Pi 4 Model B Rev 1.2",
-		// etc. Usually set on ARM SBCs.
-		SetDeviceModel(strings.Trim(string(v), "\x00\r\n\t "))
-	}
 }
 
 func osVersionLinux() string {
@@ -64,8 +59,8 @@ func osVersionLinux() string {
 	if inContainer() {
 		attrBuf.WriteString("; container")
 	}
-	if env := GetEnvType(); env != "" {
-		fmt.Fprintf(&attrBuf, "; env=%s", env)
+	if inKnative() {
+		attrBuf.WriteString("; env=kn")
 	}
 	attr := attrBuf.String()
 
@@ -98,3 +93,31 @@ func osVersionLinux() string {
 	}
 	return fmt.Sprintf("Other%s", attr)
 }
+
+func inContainer() (ret bool) {
+	lineread.File("/proc/1/cgroup", func(line []byte) error {
+		if mem.Contains(mem.B(line), mem.S("/docker/")) ||
+			mem.Contains(mem.B(line), mem.S("/lxc/")) {
+			ret = true
+			return io.EOF // arbitrary non-nil error to stop loop
+		}
+		return nil
+	})
+	lineread.File("/proc/mounts", func(line []byte) error {
+		if mem.Contains(mem.B(line), mem.S("fuse.lxcfs")) {
+			ret = true
+			return io.EOF
+		}
+		return nil
+	})
+	return
+}
+
+func inKnative() bool {
+	// https://cloud.google.com/run/docs/reference/container-contract#env-vars
+	if os.Getenv("K_REVISION") != "" && os.Getenv("K_CONFIGURATION") != "" &&
+		os.Getenv("K_SERVICE") != "" && os.Getenv("PORT") != "" {
+		return true
+	}
+	return false
+}

control/controlclient/hostinfo_windows.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 hostinfo
+package controlclient
 
 import (
 	"os/exec"

control/controlclient/map.go

@@ -6,11 +6,8 @@ package controlclient
 
 import (
 	"log"
-	"os"
 	"sort"
-	"strconv"
 
-	"inet.af/netaddr"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/netmap"
@@ -127,7 +124,7 @@ func (ms *mapSession) netmapForResponse(resp *tailcfg.MapResponse) *netmap.Netwo
 		nm.SelfNode = node
 		nm.Expiry = node.KeyExpiry
 		nm.Name = node.Name
-		nm.Addresses = filterSelfAddresses(node.Addresses)
+		nm.Addresses = node.Addresses
 		nm.User = node.User
 		nm.Hostinfo = node.Hostinfo
 		if node.MachineAuthorized {
@@ -283,19 +280,3 @@ func cloneNodes(v1 []*tailcfg.Node) []*tailcfg.Node {
 	}
 	return v2
 }
-
-var debugSelfIPv6Only, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_SELF_V6_ONLY"))
-
-func filterSelfAddresses(in []netaddr.IPPrefix) (ret []netaddr.IPPrefix) {
-	switch {
-	default:
-		return in
-	case debugSelfIPv6Only:
-		for _, a := range in {
-			if a.IP().Is6() {
-				ret = append(ret, a)
-			}
-		}
-		return ret
-	}
-}

control/controlclient/sign_supported.go

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build windows && cgo
 // +build windows,cgo
 
 // darwin,cgo is also supported by certstore but machineCertificateSubject will
@@ -19,7 +18,7 @@ import (
 	"fmt"
 	"sync"
 
-	"github.com/tailscale/certstore"
+	"github.com/github/certstore"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/wgkey"
 	"tailscale.com/util/winutil"

control/controlclient/sign_unsupported.go

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows || !cgo
 // +build !windows !cgo
 
 package controlclient

control/controlclient/status.go

@@ -64,12 +64,11 @@ func (s State) String() string {
 }
 
 type Status struct {
-	_              structs.Incomparable
-	LoginFinished  *empty.Message // nonempty when login finishes
-	LogoutFinished *empty.Message // nonempty when logout finishes
-	Err            string
-	URL            string             // interactive URL to visit to finish logging in
-	NetMap         *netmap.NetworkMap // server-pushed configuration
+	_             structs.Incomparable
+	LoginFinished *empty.Message // nonempty when login finishes
+	Err           string
+	URL           string             // interactive URL to visit to finish logging in
+	NetMap        *netmap.NetworkMap // server-pushed configuration
 
 	// The internal state should not be exposed outside this
 	// package, but we have some automated tests elsewhere that need to
@@ -87,7 +86,6 @@ func (s *Status) Equal(s2 *Status) bool {
 	}
 	return s != nil && s2 != nil &&
 		(s.LoginFinished == nil) == (s2.LoginFinished == nil) &&
-		(s.LogoutFinished == nil) == (s2.LogoutFinished == nil) &&
 		s.Err == s2.Err &&
 		s.URL == s2.URL &&
 		reflect.DeepEqual(s.Persist, s2.Persist) &&

control/controlknobs/controlknobs.go

@@ -1,34 +0,0 @@
-// 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 controlknobs contains client options configurable from control which can be turned on
-// or off. The ability to turn options on and off is for incrementally adding features in.
-package controlknobs
-
-import (
-	"os"
-	"strconv"
-
-	"tailscale.com/syncs"
-)
-
-// disableUPnP indicates whether to attempt UPnP mapping.
-var disableUPnP syncs.AtomicBool
-
-func init() {
-	v, _ := strconv.ParseBool(os.Getenv("TS_DISABLE_UPNP"))
-	SetDisableUPnP(v)
-}
-
-// DisableUPnP reports the last reported value from control
-// whether UPnP portmapping should be disabled.
-func DisableUPnP() bool {
-	return disableUPnP.Get()
-}
-
-// SetDisableUPnP sets whether control says that UPnP should be
-// disabled.
-func SetDisableUPnP(v bool) {
-	disableUPnP.Set(v)
-}

derp/derp_client.go

@@ -29,7 +29,6 @@ type Client struct {
 	br          *bufio.Reader
 	meshKey     string
 	canAckPings bool
-	isProber    bool
 
 	wmu sync.Mutex // hold while writing to bw
 	bw  *bufio.Writer
@@ -53,7 +52,6 @@ type clientOpt struct {
 	MeshKey     string
 	ServerPub   key.Public
 	CanAckPings bool
-	IsProber    bool
 }
 
 // MeshKey returns a ClientOpt to pass to the DERP server during connect to get
@@ -62,10 +60,6 @@ type clientOpt struct {
 // An empty key means to not use a mesh key.
 func MeshKey(key string) ClientOpt { return clientOptFunc(func(o *clientOpt) { o.MeshKey = key }) }
 
-// IsProber returns a ClientOpt to pass to the DERP server during connect to
-// declare that this client is a a prober.
-func IsProber(v bool) ClientOpt { return clientOptFunc(func(o *clientOpt) { o.IsProber = v }) }
-
 // ServerPublicKey returns a ClientOpt to declare that the server's DERP public key is known.
 // If key is the zero value, the returned ClientOpt is a no-op.
 func ServerPublicKey(key key.Public) ClientOpt {
@@ -99,7 +93,6 @@ func newClient(privateKey key.Private, nc Conn, brw *bufio.ReadWriter, logf logg
 		bw:          brw.Writer,
 		meshKey:     opt.MeshKey,
 		canAckPings: opt.CanAckPings,
-		isProber:    opt.IsProber,
 	}
 	if opt.ServerPub.IsZero() {
 		if err := c.recvServerKey(); err != nil {
@@ -167,9 +160,6 @@ type clientInfo struct {
 	// CanAckPings is whether the client declares it's able to ack
 	// pings.
 	CanAckPings bool
-
-	// IsProber is whether this client is a prober.
-	IsProber bool `json:",omitempty"`
 }
 
 func (c *Client) sendClientKey() error {
@@ -181,7 +171,6 @@ func (c *Client) sendClientKey() error {
 		Version:     ProtocolVersion,
 		MeshKey:     c.meshKey,
 		CanAckPings: c.canAckPings,
-		IsProber:    c.isProber,
 	})
 	if err != nil {
 		return err

derp/derp_server.go

@@ -20,30 +20,22 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
-	"math"
 	"math/big"
 	"math/rand"
-	"net/http"
 	"os"
-	"os/exec"
 	"runtime"
 	"strconv"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"go4.org/mem"
 	"golang.org/x/crypto/nacl/box"
 	"golang.org/x/sync/errgroup"
-	"golang.org/x/time/rate"
-	"inet.af/netaddr"
-	"tailscale.com/client/tailscale"
 	"tailscale.com/disco"
 	"tailscale.com/metrics"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
-	"tailscale.com/types/pad32"
 	"tailscale.com/version"
 )
 
@@ -77,6 +69,13 @@ const (
 	writeTimeout            = 2 * time.Second
 )
 
+const host64bit = (^uint(0) >> 32) & 1 // 1 on 64-bit, 0 on 32-bit
+
+// pad32bit is 4 on 32-bit machines and 0 on 64-bit.
+// It exists so the Server struct's atomic fields can be aligned to 8
+// byte boundaries. (As tested by GOARCH=386 go test, etc)
+const pad32bit = 4 - host64bit*4 // 0 on 64-bit, 4 on 32-bit
+
 // Server is a DERP server.
 type Server struct {
 	// WriteTimeout, if non-zero, specifies how long to wait
@@ -92,46 +91,42 @@ type Server struct {
 	metaCert    []byte // the encoded x509 cert to send after LetsEncrypt cert+intermediate
 
 	// Counters:
-	_                            pad32.Four
-	packetsSent, bytesSent       expvar.Int
-	packetsRecv, bytesRecv       expvar.Int
-	packetsRecvByKind            metrics.LabelMap
-	packetsRecvDisco             *expvar.Int
-	packetsRecvOther             *expvar.Int
-	_                            pad32.Four
-	packetsDropped               expvar.Int
-	packetsDroppedReason         metrics.LabelMap
-	packetsDroppedReasonCounters []*expvar.Int // indexed by dropReason
-	packetsDroppedType           metrics.LabelMap
-	packetsDroppedTypeDisco      *expvar.Int
-	packetsDroppedTypeOther      *expvar.Int
-	_                            pad32.Four
-	packetsForwardedOut          expvar.Int
-	packetsForwardedIn           expvar.Int
-	peerGoneFrames               expvar.Int // number of peer gone frames sent
-	accepts                      expvar.Int
-	curClients                   expvar.Int
-	curHomeClients               expvar.Int // ones with preferred
-	clientsReplaced              expvar.Int
-	clientsReplaceLimited        expvar.Int
-	clientsReplaceSleeping       expvar.Int
-	unknownFrames                expvar.Int
-	homeMovesIn                  expvar.Int // established clients announce home server moves in
-	homeMovesOut                 expvar.Int // established clients announce home server moves out
-	multiForwarderCreated        expvar.Int
-	multiForwarderDeleted        expvar.Int
-	removePktForwardOther        expvar.Int
-	avgQueueDuration             *uint64 // In milliseconds; accessed atomically
+	_                        [pad32bit]byte
+	packetsSent, bytesSent   expvar.Int
+	packetsRecv, bytesRecv   expvar.Int
+	packetsRecvByKind        metrics.LabelMap
+	packetsRecvDisco         *expvar.Int
+	packetsRecvOther         *expvar.Int
+	_                        [pad32bit]byte
+	packetsDropped           expvar.Int
+	packetsDroppedReason     metrics.LabelMap
+	packetsDroppedUnknown    *expvar.Int // unknown dst pubkey
+	packetsDroppedFwdUnknown *expvar.Int // unknown dst pubkey on forward
+	packetsDroppedGone       *expvar.Int // dst conn shutting down
+	packetsDroppedQueueHead  *expvar.Int // queue full, drop head packet
+	packetsDroppedQueueTail  *expvar.Int // queue full, drop tail packet
+	packetsDroppedWrite      *expvar.Int // error writing to dst conn
+	_                        [pad32bit]byte
+	packetsForwardedOut      expvar.Int
+	packetsForwardedIn       expvar.Int
+	peerGoneFrames           expvar.Int // number of peer gone frames sent
+	accepts                  expvar.Int
+	curClients               expvar.Int
+	curHomeClients           expvar.Int // ones with preferred
+	clientsReplaced          expvar.Int
+	unknownFrames            expvar.Int
+	homeMovesIn              expvar.Int // established clients announce home server moves in
+	homeMovesOut             expvar.Int // established clients announce home server moves out
+	multiForwarderCreated    expvar.Int
+	multiForwarderDeleted    expvar.Int
+	removePktForwardOther    expvar.Int
 
-	// verifyClients only accepts client connections to the DERP server if the clientKey is a
-	// known peer in the network, as specified by a running tailscaled's client's local api.
-	verifyClients bool
-
-	mu       sync.Mutex
-	closed   bool
-	netConns map[Conn]chan struct{} // chan is closed when conn closes
-	clients  map[key.Public]*sclient
-	watchers map[*sclient]bool // mesh peer -> true
+	mu          sync.Mutex
+	closed      bool
+	netConns    map[Conn]chan struct{} // chan is closed when conn closes
+	clients     map[key.Public]*sclient
+	clientsEver map[key.Public]bool // never deleted from, for stats; fine for now
+	watchers    map[*sclient]bool   // mesh peer -> true
 	// clientsMesh tracks all clients in the cluster, both locally
 	// and to mesh peers.  If the value is nil, that means the
 	// peer is only local (and thus in the clients Map, but not
@@ -143,14 +138,11 @@ type Server struct {
 	// because it includes intra-region forwarded packets as the
 	// src.
 	sentTo map[key.Public]map[key.Public]int64 // src => dst => dst's latest sclient.connNum
-
-	// maps from netaddr.IPPort to a client's public key
-	keyOfAddr map[netaddr.IPPort]key.Public
 }
 
 // PacketForwarder is something that can forward packets.
 //
-// It's mostly an interface for circular dependency reasons; the
+// It's mostly an inteface for circular dependency reasons; the
 // typical implementation is derphttp.Client. The other implementation
 // is a multiForwarder, which this package creates as needed if a
 // public key gets more than one PacketForwarder registered for it.
@@ -161,7 +153,7 @@ type PacketForwarder interface {
 // Conn is the subset of the underlying net.Conn the DERP Server needs.
 // It is a defined type so that non-net connections can be used.
 type Conn interface {
-	io.WriteCloser
+	io.Closer
 
 	// The *Deadline methods follow the semantics of net.Conn.
 
@@ -183,29 +175,23 @@ func NewServer(privateKey key.Private, logf logger.Logf) *Server {
 		limitedLogf:          logger.RateLimitedFn(logf, 30*time.Second, 5, 100),
 		packetsRecvByKind:    metrics.LabelMap{Label: "kind"},
 		packetsDroppedReason: metrics.LabelMap{Label: "reason"},
-		packetsDroppedType:   metrics.LabelMap{Label: "type"},
 		clients:              map[key.Public]*sclient{},
+		clientsEver:          map[key.Public]bool{},
 		clientsMesh:          map[key.Public]PacketForwarder{},
 		netConns:             map[Conn]chan struct{}{},
 		memSys0:              ms.Sys,
 		watchers:             map[*sclient]bool{},
 		sentTo:               map[key.Public]map[key.Public]int64{},
-		avgQueueDuration:     new(uint64),
-		keyOfAddr:            map[netaddr.IPPort]key.Public{},
 	}
 	s.initMetacert()
 	s.packetsRecvDisco = s.packetsRecvByKind.Get("disco")
 	s.packetsRecvOther = s.packetsRecvByKind.Get("other")
-	s.packetsDroppedReasonCounters = []*expvar.Int{
-		s.packetsDroppedReason.Get("unknown_dest"),
-		s.packetsDroppedReason.Get("unknown_dest_on_fwd"),
-		s.packetsDroppedReason.Get("gone"),
-		s.packetsDroppedReason.Get("queue_head"),
-		s.packetsDroppedReason.Get("queue_tail"),
-		s.packetsDroppedReason.Get("write_error"),
-	}
-	s.packetsDroppedTypeDisco = s.packetsDroppedType.Get("disco")
-	s.packetsDroppedTypeOther = s.packetsDroppedType.Get("other")
+	s.packetsDroppedUnknown = s.packetsDroppedReason.Get("unknown_dest")
+	s.packetsDroppedFwdUnknown = s.packetsDroppedReason.Get("unknown_dest_on_fwd")
+	s.packetsDroppedGone = s.packetsDroppedReason.Get("gone")
+	s.packetsDroppedQueueHead = s.packetsDroppedReason.Get("queue_head")
+	s.packetsDroppedQueueTail = s.packetsDroppedReason.Get("queue_tail")
+	s.packetsDroppedWrite = s.packetsDroppedReason.Get("write_error")
 	return s
 }
 
@@ -217,13 +203,6 @@ func (s *Server) SetMeshKey(v string) {
 	s.meshKey = v
 }
 
-// SetVerifyClients sets whether this DERP server verifies clients through tailscaled.
-//
-// It must be called before serving begins.
-func (s *Server) SetVerifyClient(v bool) {
-	s.verifyClients = v
-}
-
 // HasMeshKey reports whether the server is configured with a mesh key.
 func (s *Server) HasMeshKey() bool { return s.meshKey != "" }
 
@@ -343,40 +322,25 @@ func (s *Server) initMetacert() {
 func (s *Server) MetaCert() []byte { return s.metaCert }
 
 // registerClient notes that client c is now authenticated and ready for packets.
-//
-// If c's public key was already connected with a different
-// connection, the prior one is closed, unless it's fighting rapidly
-// with another client with the same key, in which case the returned
-// ok is false, and the caller should wait the provided duration
-// before trying again.
-func (s *Server) registerClient(c *sclient) (ok bool, d time.Duration) {
+// If c's public key was already connected with a different connection, the prior one is closed.
+func (s *Server) registerClient(c *sclient) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	old := s.clients[c.key]
 	if old == nil {
 		c.logf("adding connection")
 	} else {
-		// Take over the old rate limiter, discarding the one
-		// our caller just made.
-		c.replaceLimiter = old.replaceLimiter
-		if rr := c.replaceLimiter.ReserveN(timeNow(), 1); rr.OK() {
-			if d := rr.DelayFrom(timeNow()); d > 0 {
-				s.clientsReplaceLimited.Add(1)
-				return false, d
-			}
-		}
 		s.clientsReplaced.Add(1)
 		c.logf("adding connection, replacing %s", old.remoteAddr)
 		go old.nc.Close()
 	}
 	s.clients[c.key] = c
+	s.clientsEver[c.key] = true
 	if _, ok := s.clientsMesh[c.key]; !ok {
 		s.clientsMesh[c.key] = nil // just for varz of total users in cluster
 	}
-	s.keyOfAddr[c.remoteIPPort] = c.key
 	s.curClients.Add(1)
 	s.broadcastPeerStateChangeLocked(c.key, true)
-	return true, 0
 }
 
 // broadcastPeerStateChangeLocked enqueues a message to all watchers
@@ -409,8 +373,6 @@ func (s *Server) unregisterClient(c *sclient) {
 		delete(s.watchers, c)
 	}
 
-	delete(s.keyOfAddr, c.remoteIPPort)
-
 	s.curClients.Add(-1)
 	if c.preferred {
 		s.curHomeClients.Add(-1)
@@ -464,9 +426,8 @@ func (s *Server) addWatcher(c *sclient) {
 }
 
 func (s *Server) accept(nc Conn, brw *bufio.ReadWriter, remoteAddr string, connNum int64) error {
-	br := brw.Reader
+	br, bw := brw.Reader, brw.Writer
 	nc.SetDeadline(time.Now().Add(10 * time.Second))
-	bw := &lazyBufioWriter{w: nc, lbw: brw.Writer}
 	if err := s.sendServerKey(bw); err != nil {
 		return fmt.Errorf("send server key: %v", err)
 	}
@@ -485,32 +446,21 @@ func (s *Server) accept(nc Conn, brw *bufio.ReadWriter, remoteAddr string, connN
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	remoteIPPort, _ := netaddr.ParseIPPort(remoteAddr)
-
 	c := &sclient{
-		connNum:        connNum,
-		s:              s,
-		key:            clientKey,
-		nc:             nc,
-		br:             br,
-		bw:             bw,
-		logf:           logger.WithPrefix(s.logf, fmt.Sprintf("derp client %v/%x: ", remoteAddr, clientKey)),
-		done:           ctx.Done(),
-		remoteAddr:     remoteAddr,
-		remoteIPPort:   remoteIPPort,
-		connectedAt:    time.Now(),
-		sendQueue:      make(chan pkt, perClientSendQueueDepth),
-		discoSendQueue: make(chan pkt, perClientSendQueueDepth),
-		peerGone:       make(chan key.Public),
-		canMesh:        clientInfo.MeshKey != "" && clientInfo.MeshKey == s.meshKey,
-
-		// Allow kicking out previous connections once a
-		// minute, with a very high burst of 100. Once a
-		// minute is less than the client's 2 minute
-		// inactivity timeout.
-		replaceLimiter: rate.NewLimiter(rate.Every(time.Minute), 100),
+		connNum:     connNum,
+		s:           s,
+		key:         clientKey,
+		nc:          nc,
+		br:          br,
+		bw:          bw,
+		logf:        logger.WithPrefix(s.logf, fmt.Sprintf("derp client %v/%x: ", remoteAddr, clientKey)),
+		done:        ctx.Done(),
+		remoteAddr:  remoteAddr,
+		connectedAt: time.Now(),
+		sendQueue:   make(chan pkt, perClientSendQueueDepth),
+		peerGone:    make(chan key.Public),
+		canMesh:     clientInfo.MeshKey != "" && clientInfo.MeshKey == s.meshKey,
 	}
-
 	if c.canMesh {
 		c.meshUpdate = make(chan struct{})
 	}
@@ -518,18 +468,10 @@ func (s *Server) accept(nc Conn, brw *bufio.ReadWriter, remoteAddr string, connN
 		c.info = *clientInfo
 	}
 
-	for {
-		ok, d := s.registerClient(c)
-		if ok {
-			break
-		}
-		s.clientsReplaceSleeping.Add(1)
-		timeSleep(d)
-		s.clientsReplaceSleeping.Add(-1)
-	}
+	s.registerClient(c)
 	defer s.unregisterClient(c)
 
-	err = s.sendServerInfo(c.bw, clientKey)
+	err = s.sendServerInfo(bw, clientKey)
 	if err != nil {
 		return fmt.Errorf("send server info: %v", err)
 	}
@@ -537,12 +479,6 @@ func (s *Server) accept(nc Conn, brw *bufio.ReadWriter, remoteAddr string, connN
 	return c.run(ctx)
 }
 
-// for testing
-var (
-	timeSleep = time.Sleep
-	timeNow   = time.Now
-)
-
 // run serves the client until there's an error.
 // If the client hangs up or the server is closed, run returns nil, otherwise run returns an error.
 func (c *sclient) run(ctx context.Context) error {
@@ -666,14 +602,17 @@ func (c *sclient) handleFrameForwardPacket(ft frameType, fl uint32) error {
 	s.mu.Unlock()
 
 	if dst == nil {
-		s.recordDrop(contents, srcKey, dstKey, dropReasonUnknownDestOnFwd)
+		s.packetsDropped.Add(1)
+		s.packetsDroppedFwdUnknown.Add(1)
+		if debug {
+			c.logf("dropping forwarded packet for unknown %x", dstKey)
+		}
 		return nil
 	}
 
 	return c.sendPkt(dst, pkt{
-		bs:         contents,
-		enqueuedAt: time.Now(),
-		src:        srcKey,
+		bs:  contents,
+		src: srcKey,
 	})
 }
 
@@ -717,53 +656,21 @@ func (c *sclient) handleFrameSendPacket(ft frameType, fl uint32) error {
 			}
 			return nil
 		}
-		s.recordDrop(contents, c.key, dstKey, dropReasonUnknownDest)
+		s.packetsDropped.Add(1)
+		s.packetsDroppedUnknown.Add(1)
+		if debug {
+			c.logf("dropping packet for unknown %x", dstKey)
+		}
 		return nil
 	}
 
 	p := pkt{
-		bs:         contents,
-		enqueuedAt: time.Now(),
-		src:        c.key,
+		bs:  contents,
+		src: c.key,
 	}
 	return c.sendPkt(dst, p)
 }
 
-// dropReason is why we dropped a DERP frame.
-type dropReason int
-
-//go:generate go run tailscale.com/cmd/addlicense -year 2021 -file dropreason_string.go go run golang.org/x/tools/cmd/stringer -type=dropReason -trimprefix=dropReason
-
-const (
-	dropReasonUnknownDest      dropReason = iota // unknown destination pubkey
-	dropReasonUnknownDestOnFwd                   // unknown destination pubkey on a derp-forwarded packet
-	dropReasonGone                               // destination tailscaled disconnected before we could send
-	dropReasonQueueHead                          // destination queue is full, dropped packet at queue head
-	dropReasonQueueTail                          // destination queue is full, dropped packet at queue tail
-	dropReasonWriteError                         // OS write() failed
-)
-
-func (s *Server) recordDrop(packetBytes []byte, srcKey, dstKey key.Public, reason dropReason) {
-	s.packetsDropped.Add(1)
-	s.packetsDroppedReasonCounters[reason].Add(1)
-	if disco.LooksLikeDiscoWrapper(packetBytes) {
-		s.packetsDroppedTypeDisco.Add(1)
-	} else {
-		s.packetsDroppedTypeOther.Add(1)
-	}
-	if verboseDropKeys[dstKey] {
-		// Preformat the log string prior to calling limitedLogf. The
-		// limiter acts based on the format string, and we want to
-		// rate-limit per src/dst keys, not on the generic "dropped
-		// stuff" message.
-		msg := fmt.Sprintf("drop (%s) %s -> %s", srcKey.ShortString(), reason, dstKey.ShortString())
-		s.limitedLogf(msg)
-	}
-	if debug {
-		s.logf("dropping packet reason=%s dst=%s disco=%v", reason, dstKey, disco.LooksLikeDiscoWrapper(packetBytes))
-	}
-}
-
 func (c *sclient) sendPkt(dst *sclient, p pkt) error {
 	s := c.s
 	dstKey := dst.key
@@ -771,34 +678,53 @@ func (c *sclient) sendPkt(dst *sclient, p pkt) error {
 	// Attempt to queue for sending up to 3 times. On each attempt, if
 	// the queue is full, try to drop from queue head to prioritize
 	// fresher packets.
-	sendQueue := dst.sendQueue
-	if disco.LooksLikeDiscoWrapper(p.bs) {
-		sendQueue = dst.discoSendQueue
-	}
 	for attempt := 0; attempt < 3; attempt++ {
 		select {
 		case <-dst.done:
-			s.recordDrop(p.bs, c.key, dstKey, dropReasonGone)
+			s.packetsDropped.Add(1)
+			s.packetsDroppedGone.Add(1)
+			if debug {
+				c.logf("dropping packet for shutdown client %x", dstKey)
+			}
 			return nil
 		default:
 		}
 		select {
-		case sendQueue <- p:
+		case dst.sendQueue <- p:
 			return nil
 		default:
 		}
 
 		select {
-		case pkt := <-sendQueue:
-			s.recordDrop(pkt.bs, c.key, dstKey, dropReasonQueueHead)
-			c.recordQueueTime(pkt.enqueuedAt)
+		case <-dst.sendQueue:
+			s.packetsDropped.Add(1)
+			s.packetsDroppedQueueHead.Add(1)
+			if verboseDropKeys[dstKey] {
+				// Generate a full string including src and dst, so
+				// the limiter kicks in once per src.
+				msg := fmt.Sprintf("tail drop %s -> %s", p.src.ShortString(), dstKey.ShortString())
+				c.s.limitedLogf(msg)
+			}
+			if debug {
+				c.logf("dropping packet from client %x queue head", dstKey)
+			}
 		default:
 		}
 	}
 	// Failed to make room for packet. This can happen in a heavily
 	// contended queue with racing writers. Give up and tail-drop in
 	// this case to keep reader unblocked.
-	s.recordDrop(p.bs, c.key, dstKey, dropReasonQueueTail)
+	s.packetsDropped.Add(1)
+	s.packetsDroppedQueueTail.Add(1)
+	if verboseDropKeys[dstKey] {
+		// Generate a full string including src and dst, so
+		// the limiter kicks in once per src.
+		msg := fmt.Sprintf("head drop %s -> %s", p.src.ShortString(), dstKey.ShortString())
+		c.s.limitedLogf(msg)
+	}
+	if debug {
+		c.logf("dropping packet from client %x queue tail", dstKey)
+	}
 
 	return nil
 }
@@ -824,37 +750,23 @@ func (c *sclient) requestMeshUpdate() {
 }
 
 func (s *Server) verifyClient(clientKey key.Public, info *clientInfo) error {
-	if !s.verifyClients {
-		return nil
-	}
-	status, err := tailscale.Status(context.TODO())
-	if err != nil {
-		return fmt.Errorf("failed to query local tailscaled status: %w", err)
-	}
-	if clientKey == status.Self.PublicKey {
-		return nil
-	}
-	if _, exists := status.Peer[clientKey]; !exists {
-		return fmt.Errorf("client %v not in set of peers", clientKey)
-	}
-	// TODO(bradfitz): add policy for configurable bandwidth rate per client?
+	// TODO(crawshaw): implement policy constraints on who can use the DERP server
+	// TODO(bradfitz): ... and at what rate.
 	return nil
 }
 
-func (s *Server) sendServerKey(lw *lazyBufioWriter) error {
+func (s *Server) sendServerKey(bw *bufio.Writer) error {
 	buf := make([]byte, 0, len(magic)+len(s.publicKey))
 	buf = append(buf, magic...)
 	buf = append(buf, s.publicKey[:]...)
-	err := writeFrame(lw.bw(), frameServerKey, buf)
-	lw.Flush() // redundant (no-op) flush to release bufio.Writer
-	return err
+	return writeFrame(bw, frameServerKey, buf)
 }
 
 type serverInfo struct {
 	Version int `json:"version,omitempty"`
 }
 
-func (s *Server) sendServerInfo(bw *lazyBufioWriter, clientKey key.Public) error {
+func (s *Server) sendServerInfo(bw *bufio.Writer, clientKey key.Public) error {
 	var nonce [24]byte
 	if _, err := crand.Read(nonce[:]); err != nil {
 		return err
@@ -865,7 +777,7 @@ func (s *Server) sendServerInfo(bw *lazyBufioWriter, clientKey key.Public) error
 	}
 
 	msgbox := box.Seal(nil, msg, &nonce, clientKey.B32(), s.privateKey.B32())
-	if err := writeFrameHeader(bw.bw(), frameServerInfo, nonceLen+uint32(len(msgbox))); err != nil {
+	if err := writeFrameHeader(bw, frameServerInfo, nonceLen+uint32(len(msgbox))); err != nil {
 		return err
 	}
 	if _, err := bw.Write(nonce[:]); err != nil {
@@ -973,25 +885,18 @@ func (s *Server) recvForwardPacket(br *bufio.Reader, frameLen uint32) (srcKey, d
 // (The "s" prefix is to more explicitly distinguish it from Client in derp_client.go)
 type sclient struct {
 	// Static after construction.
-	connNum        int64 // process-wide unique counter, incremented each Accept
-	s              *Server
-	nc             Conn
-	key            key.Public
-	info           clientInfo
-	logf           logger.Logf
-	done           <-chan struct{} // closed when connection closes
-	remoteAddr     string          // usually ip:port from net.Conn.RemoteAddr().String()
-	remoteIPPort   netaddr.IPPort  // zero if remoteAddr is not ip:port.
-	sendQueue      chan pkt        // packets queued to this client; never closed
-	discoSendQueue chan pkt        // important packets queued to this client; never closed
-	peerGone       chan key.Public // write request that a previous sender has disconnected (not used by mesh peers)
-	meshUpdate     chan struct{}   // write request to write peerStateChange
-	canMesh        bool            // clientInfo had correct mesh token for inter-region routing
-
-	// replaceLimiter controls how quickly two connections with
-	// the same client key can kick each other off the server by
-	// taking over ownership of a key.
-	replaceLimiter *rate.Limiter
+	connNum    int64 // process-wide unique counter, incremented each Accept
+	s          *Server
+	nc         Conn
+	key        key.Public
+	info       clientInfo
+	logf       logger.Logf
+	done       <-chan struct{} // closed when connection closes
+	remoteAddr string          // usually ip:port from net.Conn.RemoteAddr().String()
+	sendQueue  chan pkt        // packets queued to this client; never closed
+	peerGone   chan key.Public // write request that a previous sender has disconnected (not used by mesh peers)
+	meshUpdate chan struct{}   // write request to write peerStateChange
+	canMesh    bool            // clientInfo had correct mesh token for inter-region routing
 
 	// Owned by run, not thread-safe.
 	br          *bufio.Reader
@@ -999,7 +904,7 @@ type sclient struct {
 	preferred   bool
 
 	// Owned by sender, not thread-safe.
-	bw *lazyBufioWriter
+	bw *bufio.Writer
 
 	// Guarded by s.mu
 	//
@@ -1022,13 +927,11 @@ type pkt struct {
 	// src is the who's the sender of the packet.
 	src key.Public
 
-	// enqueuedAt is when a packet was put onto a queue before it was sent,
-	// and is used for reporting metrics on the duration of packets in the queue.
-	enqueuedAt time.Time
-
 	// bs is the data packet bytes.
 	// The memory is owned by pkt.
 	bs []byte
+
+	// TODO(danderson): enqueue time, to measure queue latency?
 }
 
 func (c *sclient) setPreferred(v bool) {
@@ -1056,25 +959,6 @@ func (c *sclient) setPreferred(v bool) {
 	}
 }
 
-// expMovingAverage returns the new moving average given the previous average,
-// a new value, and an alpha decay factor.
-// https://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
-func expMovingAverage(prev, newValue, alpha float64) float64 {
-	return alpha*newValue + (1-alpha)*prev
-}
-
-// recordQueueTime updates the average queue duration metric after a packet has been sent.
-func (c *sclient) recordQueueTime(enqueuedAt time.Time) {
-	elapsed := float64(time.Since(enqueuedAt).Milliseconds())
-	for {
-		old := atomic.LoadUint64(c.s.avgQueueDuration)
-		newAvg := expMovingAverage(math.Float64frombits(old), elapsed, 0.1)
-		if atomic.CompareAndSwapUint64(c.s.avgQueueDuration, old, math.Float64bits(newAvg)) {
-			break
-		}
-	}
-}
-
 func (c *sclient) sendLoop(ctx context.Context) error {
 	defer func() {
 		// If the sender shuts down unilaterally due to an error, close so
@@ -1084,10 +968,12 @@ func (c *sclient) sendLoop(ctx context.Context) error {
 		// Drain the send queue to count dropped packets
 		for {
 			select {
-			case pkt := <-c.sendQueue:
-				c.s.recordDrop(pkt.bs, pkt.src, c.key, dropReasonGone)
-			case pkt := <-c.discoSendQueue:
-				c.s.recordDrop(pkt.bs, pkt.src, c.key, dropReasonGone)
+			case <-c.sendQueue:
+				c.s.packetsDropped.Add(1)
+				c.s.packetsDroppedGone.Add(1)
+				if debug {
+					c.logf("dropping packet for shutdown %x", c.key)
+				}
 			default:
 				return
 			}
@@ -1116,11 +1002,6 @@ func (c *sclient) sendLoop(ctx context.Context) error {
 			continue
 		case msg := <-c.sendQueue:
 			werr = c.sendPacket(msg.src, msg.bs)
-			c.recordQueueTime(msg.enqueuedAt)
-			continue
-		case msg := <-c.discoSendQueue:
-			werr = c.sendPacket(msg.src, msg.bs)
-			c.recordQueueTime(msg.enqueuedAt)
 			continue
 		case <-keepAliveTick.C:
 			werr = c.sendKeepAlive()
@@ -1144,10 +1025,6 @@ func (c *sclient) sendLoop(ctx context.Context) error {
 			continue
 		case msg := <-c.sendQueue:
 			werr = c.sendPacket(msg.src, msg.bs)
-			c.recordQueueTime(msg.enqueuedAt)
-		case msg := <-c.discoSendQueue:
-			werr = c.sendPacket(msg.src, msg.bs)
-			c.recordQueueTime(msg.enqueuedAt)
 		case <-keepAliveTick.C:
 			werr = c.sendKeepAlive()
 		}
@@ -1161,14 +1038,14 @@ func (c *sclient) setWriteDeadline() {
 // sendKeepAlive sends a keep-alive frame, without flushing.
 func (c *sclient) sendKeepAlive() error {
 	c.setWriteDeadline()
-	return writeFrameHeader(c.bw.bw(), frameKeepAlive, 0)
+	return writeFrameHeader(c.bw, frameKeepAlive, 0)
 }
 
 // sendPeerGone sends a peerGone frame, without flushing.
 func (c *sclient) sendPeerGone(peer key.Public) error {
 	c.s.peerGoneFrames.Add(1)
 	c.setWriteDeadline()
-	if err := writeFrameHeader(c.bw.bw(), framePeerGone, keyLen); err != nil {
+	if err := writeFrameHeader(c.bw, framePeerGone, keyLen); err != nil {
 		return err
 	}
 	_, err := c.bw.Write(peer[:])
@@ -1178,7 +1055,7 @@ func (c *sclient) sendPeerGone(peer key.Public) error {
 // sendPeerPresent sends a peerPresent frame, without flushing.
 func (c *sclient) sendPeerPresent(peer key.Public) error {
 	c.setWriteDeadline()
-	if err := writeFrameHeader(c.bw.bw(), framePeerPresent, keyLen); err != nil {
+	if err := writeFrameHeader(c.bw, framePeerPresent, keyLen); err != nil {
 		return err
 	}
 	_, err := c.bw.Write(peer[:])
@@ -1237,7 +1114,11 @@ func (c *sclient) sendPacket(srcKey key.Public, contents []byte) (err error) {
 	defer func() {
 		// Stats update.
 		if err != nil {
-			c.s.recordDrop(contents, srcKey, c.key, dropReasonWriteError)
+			c.s.packetsDropped.Add(1)
+			c.s.packetsDroppedWrite.Add(1)
+			if debug {
+				c.logf("dropping packet to %x: %v", c.key, err)
+			}
 		} else {
 			c.s.packetsSent.Add(1)
 			c.s.bytesSent.Add(int64(len(contents)))
@@ -1251,11 +1132,11 @@ func (c *sclient) sendPacket(srcKey key.Public, contents []byte) (err error) {
 	if withKey {
 		pktLen += len(srcKey)
 	}
-	if err = writeFrameHeader(c.bw.bw(), frameRecvPacket, uint32(pktLen)); err != nil {
+	if err = writeFrameHeader(c.bw, frameRecvPacket, uint32(pktLen)); err != nil {
 		return err
 	}
 	if withKey {
-		err := writePublicKey(c.bw.bw(), &srcKey)
+		err := writePublicKey(c.bw, &srcKey)
 		if err != nil {
 			return err
 		}
@@ -1275,7 +1156,7 @@ func (s *Server) AddPacketForwarder(dst key.Public, fwd PacketForwarder) {
 			return
 		}
 		if m, ok := prev.(multiForwarder); ok {
-			if _, ok := m[fwd]; ok {
+			if _, ok := m[fwd]; !ok {
 				// Duplicate registration of same forwarder in set; ignore.
 				return
 			}
@@ -1383,6 +1264,7 @@ func (s *Server) expVarFunc(f func() interface{}) expvar.Func {
 // ExpVar returns an expvar variable suitable for registering with expvar.Publish.
 func (s *Server) ExpVar() expvar.Var {
 	m := new(metrics.Set)
+	m.Set("counter_unique_clients_ever", s.expVarFunc(func() interface{} { return len(s.clientsEver) }))
 	m.Set("gauge_memstats_sys0", expvar.Func(func() interface{} { return int64(s.memSys0) }))
 	m.Set("gauge_watchers", s.expVarFunc(func() interface{} { return len(s.watchers) }))
 	m.Set("gauge_current_connections", &s.curClients)
@@ -1392,13 +1274,10 @@ func (s *Server) ExpVar() expvar.Var {
 	m.Set("gauge_clients_remote", expvar.Func(func() interface{} { return len(s.clientsMesh) - len(s.clients) }))
 	m.Set("accepts", &s.accepts)
 	m.Set("clients_replaced", &s.clientsReplaced)
-	m.Set("clients_replace_limited", &s.clientsReplaceLimited)
-	m.Set("gauge_clients_replace_sleeping", &s.clientsReplaceSleeping)
 	m.Set("bytes_received", &s.bytesRecv)
 	m.Set("bytes_sent", &s.bytesSent)
 	m.Set("packets_dropped", &s.packetsDropped)
 	m.Set("counter_packets_dropped_reason", &s.packetsDroppedReason)
-	m.Set("counter_packets_dropped_type", &s.packetsDroppedType)
 	m.Set("counter_packets_received_kind", &s.packetsRecvByKind)
 	m.Set("packets_sent", &s.packetsSent)
 	m.Set("packets_received", &s.packetsRecv)
@@ -1411,9 +1290,6 @@ func (s *Server) ExpVar() expvar.Var {
 	m.Set("multiforwarder_created", &s.multiForwarderCreated)
 	m.Set("multiforwarder_deleted", &s.multiForwarderDeleted)
 	m.Set("packet_forwarder_delete_other_value", &s.removePktForwardOther)
-	m.Set("average_queue_duration_ms", expvar.Func(func() interface{} {
-		return math.Float64frombits(atomic.LoadUint64(s.avgQueueDuration))
-	}))
 	var expvarVersion expvar.String
 	expvarVersion.Set(version.Long)
 	m.Set("version", &expvarVersion)
@@ -1489,126 +1365,3 @@ func writePublicKey(bw *bufio.Writer, key *key.Public) error {
 	}
 	return nil
 }
-
-const minTimeBetweenLogs = 2 * time.Second
-
-// BytesSentRecv records the number of bytes that have been sent since the last traffic check
-// for a given process, as well as the public key of the process sending those bytes.
-type BytesSentRecv struct {
-	Sent uint64
-	Recv uint64
-	// Key is the public key of the client which sent/received these bytes.
-	Key key.Public
-}
-
-// parseSSOutput parses the output from the specific call to ss in ServeDebugTraffic.
-// Separated out for ease of testing.
-func parseSSOutput(raw string) map[netaddr.IPPort]BytesSentRecv {
-	newState := map[netaddr.IPPort]BytesSentRecv{}
-	// parse every 2 lines and get src and dst ips, and kv pairs
-	lines := strings.Split(raw, "\n")
-	for i := 0; i < len(lines); i += 2 {
-		ipInfo := strings.Fields(strings.TrimSpace(lines[i]))
-		if len(ipInfo) < 5 {
-			continue
-		}
-		src, err := netaddr.ParseIPPort(ipInfo[4])
-		if err != nil {
-			continue
-		}
-		stats := strings.Fields(strings.TrimSpace(lines[i+1]))
-		stat := BytesSentRecv{}
-		for _, s := range stats {
-			if strings.Contains(s, "bytes_sent") {
-				sent, err := strconv.Atoi(s[strings.Index(s, ":")+1:])
-				if err == nil {
-					stat.Sent = uint64(sent)
-				}
-			} else if strings.Contains(s, "bytes_received") {
-				recv, err := strconv.Atoi(s[strings.Index(s, ":")+1:])
-				if err == nil {
-					stat.Recv = uint64(recv)
-				}
-			}
-		}
-		newState[src] = stat
-	}
-	return newState
-}
-
-func (s *Server) ServeDebugTraffic(w http.ResponseWriter, r *http.Request) {
-	prevState := map[netaddr.IPPort]BytesSentRecv{}
-	enc := json.NewEncoder(w)
-	for r.Context().Err() == nil {
-		output, err := exec.Command("ss", "-i", "-H", "-t").Output()
-		if err != nil {
-			fmt.Fprintf(w, "ss failed: %v", err)
-			return
-		}
-		newState := parseSSOutput(string(output))
-		s.mu.Lock()
-		for k, next := range newState {
-			prev := prevState[k]
-			if prev.Sent < next.Sent || prev.Recv < next.Recv {
-				if pkey, ok := s.keyOfAddr[k]; ok {
-					next.Key = pkey
-					if err := enc.Encode(next); err != nil {
-						s.mu.Unlock()
-						return
-					}
-				}
-			}
-		}
-		s.mu.Unlock()
-		prevState = newState
-		if _, err := fmt.Fprintln(w); err != nil {
-			return
-		}
-		if f, ok := w.(http.Flusher); ok {
-			f.Flush()
-		}
-		time.Sleep(minTimeBetweenLogs)
-	}
-}
-
-var bufioWriterPool = &sync.Pool{
-	New: func() interface{} {
-		return bufio.NewWriterSize(ioutil.Discard, 2<<10)
-	},
-}
-
-// lazyBufioWriter is a bufio.Writer-like wrapping writer that lazily
-// allocates its actual bufio.Writer from a sync.Pool, releasing it to
-// the pool upon flush.
-//
-// We do this to reduce memory overhead; most DERP connections are
-// idle and the idle bufio.Writers were 30% of overall memory usage.
-type lazyBufioWriter struct {
-	w   io.Writer     // underlying
-	lbw *bufio.Writer // lazy; nil means it needs an associated buffer
-}
-
-func (w *lazyBufioWriter) bw() *bufio.Writer {
-	if w.lbw == nil {
-		w.lbw = bufioWriterPool.Get().(*bufio.Writer)
-		w.lbw.Reset(w.w)
-	}
-	return w.lbw
-}
-
-func (w *lazyBufioWriter) Available() int { return w.bw().Available() }
-
-func (w *lazyBufioWriter) Write(p []byte) (int, error) { return w.bw().Write(p) }
-
-func (w *lazyBufioWriter) Flush() error {
-	if w.lbw == nil {
-		return nil
-	}
-	err := w.lbw.Flush()
-
-	w.lbw.Reset(ioutil.Discard)
-	bufioWriterPool.Put(w.lbw)
-	w.lbw = nil
-
-	return err
-}

derp/derp_test.go

@@ -23,7 +23,6 @@ import (
 	"testing"
 	"time"
 
-	"golang.org/x/time/rate"
 	"tailscale.com/net/nettest"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
@@ -712,7 +711,6 @@ func TestForwarderRegistration(t *testing.T) {
 	// Adding a dup for a user.
 	wantCounter(&s.multiForwarderCreated, 0)
 	s.AddPacketForwarder(u1, testFwd(100))
-	s.AddPacketForwarder(u1, testFwd(100)) // dup to trigger dup path
 	want(map[key.Public]PacketForwarder{
 		u1: multiForwarder{
 			testFwd(1):   1,
@@ -851,136 +849,6 @@ func TestClientSendPong(t *testing.T) {
 
 }
 
-func TestServerReplaceClients(t *testing.T) {
-	defer func() {
-		timeSleep = time.Sleep
-		timeNow = time.Now
-	}()
-
-	var (
-		mu     sync.Mutex
-		now    = time.Unix(123, 0)
-		sleeps int
-		slept  time.Duration
-	)
-	timeSleep = func(d time.Duration) {
-		mu.Lock()
-		defer mu.Unlock()
-		sleeps++
-		slept += d
-		now = now.Add(d)
-	}
-	timeNow = func() time.Time {
-		mu.Lock()
-		defer mu.Unlock()
-		return now
-	}
-
-	serverPrivateKey := newPrivateKey(t)
-	var logger logger.Logf = logger.Discard
-	const debug = false
-	if debug {
-		logger = t.Logf
-	}
-
-	s := NewServer(serverPrivateKey, logger)
-	defer s.Close()
-
-	priv := newPrivateKey(t)
-
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer ln.Close()
-
-	connNum := 0
-	connect := func() *Client {
-		connNum++
-		cout, err := net.Dial("tcp", ln.Addr().String())
-		if err != nil {
-			t.Fatal(err)
-		}
-
-		cin, err := ln.Accept()
-		if err != nil {
-			t.Fatal(err)
-		}
-
-		brwServer := bufio.NewReadWriter(bufio.NewReader(cin), bufio.NewWriter(cin))
-		go s.Accept(cin, brwServer, fmt.Sprintf("test-client-%d", connNum))
-
-		brw := bufio.NewReadWriter(bufio.NewReader(cout), bufio.NewWriter(cout))
-		c, err := NewClient(priv, cout, brw, logger)
-		if err != nil {
-			t.Fatalf("client %d: %v", connNum, err)
-		}
-		return c
-	}
-
-	wantVar := func(v *expvar.Int, want int64) {
-		t.Helper()
-		if got := v.Value(); got != want {
-			t.Errorf("got %d; want %d", got, want)
-		}
-	}
-
-	wantClosed := func(c *Client) {
-		t.Helper()
-		for {
-			m, err := c.Recv()
-			if err != nil {
-				t.Logf("got expected error: %v", err)
-				return
-			}
-			switch m.(type) {
-			case ServerInfoMessage:
-				continue
-			default:
-				t.Fatalf("client got %T; wanted an error", m)
-			}
-		}
-	}
-
-	c1 := connect()
-	waitConnect(t, c1)
-	c2 := connect()
-	waitConnect(t, c2)
-	wantVar(&s.clientsReplaced, 1)
-	wantClosed(c1)
-
-	for i := 0; i < 100+5; i++ {
-		c := connect()
-		defer c.nc.Close()
-		if s.clientsReplaceLimited.Value() == 0 && i < 90 {
-			continue
-		}
-		t.Logf("for %d: replaced=%d, limited=%d, sleeping=%d", i,
-			s.clientsReplaced.Value(),
-			s.clientsReplaceLimited.Value(),
-			s.clientsReplaceSleeping.Value(),
-		)
-	}
-
-	mu.Lock()
-	defer mu.Unlock()
-	if sleeps == 0 {
-		t.Errorf("no sleeps")
-	}
-	if slept == 0 {
-		t.Errorf("total sleep duration was 0")
-	}
-}
-
-func TestLimiter(t *testing.T) {
-	rl := rate.NewLimiter(rate.Every(time.Minute), 100)
-	for i := 0; i < 200; i++ {
-		r := rl.Reserve()
-		d := r.Delay()
-		t.Logf("i=%d, allow=%v, d=%v", i, r.OK(), d)
-	}
-}
-
 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) })
@@ -1080,14 +948,3 @@ func waitConnect(t testing.TB, c *Client) {
 		t.Fatalf("client first Recv was unexpected type %T", v)
 	}
 }
-
-func TestParseSSOutput(t *testing.T) {
-	contents, err := ioutil.ReadFile("testdata/example_ss.txt")
-	if err != nil {
-		t.Errorf("ioutil.Readfile(example_ss.txt) failed: %v", err)
-	}
-	seen := parseSSOutput(string(contents))
-	if len(seen) == 0 {
-		t.Errorf("parseSSOutput expected non-empty map")
-	}
-}

derp/derphttp/derphttp_client.go

@@ -50,11 +50,9 @@ type Client struct {
 	TLSConfig *tls.Config        // optional; nil means default
 	DNSCache  *dnscache.Resolver // optional; nil means no caching
 	MeshKey   string             // optional; for trusted clients
-	IsProber  bool               // optional; for probers to optional declare themselves as such
 
 	privateKey key.Private
 	logf       logger.Logf
-	dialer     func(ctx context.Context, network, addr string) (net.Conn, error)
 
 	// Either url or getRegion is non-nil:
 	url       *url.URL
@@ -132,11 +130,6 @@ func (c *Client) ServerPublicKey() key.Public {
 	return c.serverPubKey
 }
 
-// SelfPublicKey returns our own public key.
-func (c *Client) SelfPublicKey() key.Public {
-	return c.privateKey.Public()
-}
-
 func urlPort(u *url.URL) string {
 	if p := u.Port(); p != "" {
 		return p
@@ -345,7 +338,6 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien
 		derp.MeshKey(c.MeshKey),
 		derp.ServerPublicKey(serverPub),
 		derp.CanAckPings(c.canAckPings),
-		derp.IsProber(c.IsProber),
 	)
 	if err != nil {
 		return nil, 0, err
@@ -364,26 +356,14 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien
 	return c.client, c.connGen, nil
 }
 
-// SetURLDialer sets the dialer to use for dialing URLs.
-// This dialer is only use for clients created with NewClient, not NewRegionClient.
-// If unset or nil, the default dialer is used.
-//
-// The primary use for this is the derper mesh mode to connect to each
-// other over a VPC network.
-func (c *Client) SetURLDialer(dialer func(ctx context.Context, network, addr string) (net.Conn, error)) {
-	c.dialer = dialer
-}
-
 func (c *Client) dialURL(ctx context.Context) (net.Conn, error) {
 	host := c.url.Hostname()
-	if c.dialer != nil {
-		return c.dialer(ctx, "tcp", net.JoinHostPort(host, urlPort(c.url)))
-	}
 	hostOrIP := host
+
 	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()
 		}
@@ -430,7 +410,9 @@ func (c *Client) dialRegion(ctx context.Context, reg *tailcfg.DERPRegion) (net.C
 func (c *Client) tlsClient(nc net.Conn, node *tailcfg.DERPNode) *tls.Conn {
 	tlsConf := tlsdial.Config(c.tlsServerName(node), c.TLSConfig)
 	if node != nil {
-		tlsConf.InsecureSkipVerify = node.InsecureForTests
+		if node.DERPTestPort != 0 {
+			tlsConf.InsecureSkipVerify = true
+		}
 		if node.CertName != "" {
 			tlsdial.SetConfigExpectedCert(tlsConf, node.CertName)
 		}
@@ -529,8 +511,8 @@ func (c *Client) dialNode(ctx context.Context, n *tailcfg.DERPNode) (net.Conn, e
 				dst = n.HostName
 			}
 			port := "443"
-			if n.DERPPort != 0 {
-				port = fmt.Sprint(n.DERPPort)
+			if n.DERPTestPort != 0 {
+				port = fmt.Sprint(n.DERPTestPort)
 			}
 			c, err := c.dialContext(ctx, proto, net.JoinHostPort(dst, port))
 			select {

derp/derpmap/derpmap.go

@@ -0,0 +1,91 @@
+// 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 derpmap contains information about Tailscale.com's production DERP nodes.
+//
+// This package is only used by the "tailscale netcheck" command for debugging.
+// In normal operation the Tailscale nodes get this sent to them from the control
+// server.
+//
+// TODO: remove this package and make "tailscale netcheck" get the
+// list from the control server too.
+package derpmap
+
+import (
+	"fmt"
+	"strings"
+
+	"tailscale.com/tailcfg"
+)
+
+func derpNode(suffix, v4, v6 string) *tailcfg.DERPNode {
+	return &tailcfg.DERPNode{
+		Name:     suffix, // updated later
+		RegionID: 0,      // updated later
+		IPv4:     v4,
+		IPv6:     v6,
+	}
+}
+
+func derpRegion(id int, code, name string, nodes ...*tailcfg.DERPNode) *tailcfg.DERPRegion {
+	region := &tailcfg.DERPRegion{
+		RegionID:   id,
+		RegionName: name,
+		RegionCode: code,
+		Nodes:      nodes,
+	}
+	for _, n := range nodes {
+		n.Name = fmt.Sprintf("%d%s", id, n.Name)
+		n.RegionID = id
+		n.HostName = fmt.Sprintf("derp%s.tailscale.com", strings.TrimSuffix(n.Name, "a"))
+	}
+	return region
+}
+
+// Prod returns Tailscale's map of relay servers.
+//
+// This list is only used by cmd/tailscale's netcheck subcommand. In
+// normal operation the Tailscale nodes get this sent to them from the
+// control server.
+//
+// This list is subject to change and should not be relied on.
+func Prod() *tailcfg.DERPMap {
+	return &tailcfg.DERPMap{
+		Regions: map[int]*tailcfg.DERPRegion{
+			1: derpRegion(1, "nyc", "New York City",
+				derpNode("a", "159.89.225.99", "2604:a880:400:d1::828:b001"),
+			),
+			2: derpRegion(2, "sfo", "San Francisco",
+				derpNode("a", "167.172.206.31", "2604:a880:2:d1::c5:7001"),
+			),
+			3: derpRegion(3, "sin", "Singapore",
+				derpNode("a", "68.183.179.66", "2400:6180:0:d1::67d:8001"),
+			),
+			4: derpRegion(4, "fra", "Frankfurt",
+				derpNode("a", "167.172.182.26", "2a03:b0c0:3:e0::36e:9001"),
+			),
+			5: derpRegion(5, "syd", "Sydney",
+				derpNode("a", "103.43.75.49", "2001:19f0:5801:10b7:5400:2ff:feaa:284c"),
+			),
+			6: derpRegion(6, "blr", "Bangalore",
+				derpNode("a", "68.183.90.120", "2400:6180:100:d0::982:d001"),
+			),
+			7: derpRegion(7, "tok", "Tokyo",
+				derpNode("a", "167.179.89.145", "2401:c080:1000:467f:5400:2ff:feee:22aa"),
+			),
+			8: derpRegion(8, "lhr", "London",
+				derpNode("a", "167.71.139.179", "2a03:b0c0:1:e0::3cc:e001"),
+			),
+			9: derpRegion(9, "dfw", "Dallas",
+				derpNode("a", "207.148.3.137", "2001:19f0:6401:1d9c:5400:2ff:feef:bb82"),
+			),
+			10: derpRegion(10, "sea", "Seattle",
+				derpNode("a", "137.220.36.168", "2001:19f0:8001:2d9:5400:2ff:feef:bbb1"),
+			),
+			11: derpRegion(11, "sao", "São Paulo",
+				derpNode("a", "18.230.97.74", "2600:1f1e:ee4:5611:ec5c:1736:d43b:a454"),
+			),
+		},
+	}
+}

derp/dropreason_string.go

@@ -1,32 +0,0 @@
-// 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.
-
-// Code generated by "stringer -type=dropReason -trimprefix=dropReason"; DO NOT EDIT.
-
-package derp
-
-import "strconv"
-
-func _() {
-	// An "invalid array index" compiler error signifies that the constant values have changed.
-	// Re-run the stringer command to generate them again.
-	var x [1]struct{}
-	_ = x[dropReasonUnknownDest-0]
-	_ = x[dropReasonUnknownDestOnFwd-1]
-	_ = x[dropReasonGone-2]
-	_ = x[dropReasonQueueHead-3]
-	_ = x[dropReasonQueueTail-4]
-	_ = x[dropReasonWriteError-5]
-}
-
-const _dropReason_name = "UnknownDestUnknownDestOnFwdGoneQueueHeadQueueTailWriteError"
-
-var _dropReason_index = [...]uint8{0, 11, 27, 31, 40, 49, 59}
-
-func (i dropReason) String() string {
-	if i < 0 || i >= dropReason(len(_dropReason_index)-1) {
-		return "dropReason(" + strconv.FormatInt(int64(i), 10) + ")"
-	}
-	return _dropReason_name[_dropReason_index[i]:_dropReason_index[i+1]]
-}

derp/testdata/example_ss.txt

@@ -1,8 +0,0 @@
-ESTAB 0      0       10.255.1.11:35238  34.210.105.16:https
-         cubic wscale:7,7 rto:236 rtt:34.14/3.432 ato:40 mss:1448 pmtu:1500 rcvmss:1448 advmss:1448 cwnd:8 ssthresh:6 bytes_sent:38056577 bytes_retrans:2918 bytes_acked:38053660 bytes_received:6973211 segs_out:165090 segs_in:124227 data_segs_out:78018 data_segs_in:71645 send 2.71Mbps lastsnd:1156 lastrcv:1120 lastack:1120 pacing_rate 3.26Mbps delivery_rate 2.35Mbps delivered:78017 app_limited busy:2586132ms retrans:0/6 dsack_dups:4 reordering:5 reord_seen:15 rcv_rtt:126355 rcv_space:65780 rcv_ssthresh:541928 minrtt:26.632
-ESTAB 0      80     100.79.58.14:ssh    100.95.73.104:58145
-         cubic wscale:6,7 rto:224 rtt:23.051/2.03 ato:172 mss:1228 pmtu:1280 rcvmss:1228 advmss:1228 cwnd:10 ssthresh:94 bytes_sent:1591815 bytes_retrans:944 bytes_acked:1590791 bytes_received:158925 segs_out:8070 segs_in:8858 data_segs_out:7452 data_segs_in:3789 send 4.26Mbps lastsnd:4 lastrcv:4 lastack:4 pacing_rate 8.52Mbps delivery_rate 10.9Mbps delivered:7451 app_limited busy:61656ms unacked:2 retrans:0/10 dsack_dups:10 rcv_rtt:174712 rcv_space:65025 rcv_ssthresh:64296 minrtt:16.186                                   
-ESTAB 0      374     10.255.1.11:43254 167.172.206.31:https
-         cubic wscale:7,7 rto:224 rtt:22.55/1.941 ato:40 mss:1448 pmtu:1500 rcvmss:1448 advmss:1448 cwnd:6 ssthresh:4 bytes_sent:14594668 bytes_retrans:173314 bytes_acked:14420981 bytes_received:4207111 segs_out:80566 segs_in:70310 data_segs_out:24317 data_segs_in:20365 send 3.08Mbps lastsnd:4 lastrcv:4 lastack:4 pacing_rate 3.7Mbps delivery_rate 3.05Mbps delivered:24111 app_limited busy:184820ms unacked:2 retrans:0/185 dsack_dups:1 reord_seen:3 rcv_rtt:651.262 rcv_space:226657 rcv_ssthresh:1557136 minrtt:10.18           
-ESTAB 0      0       10.255.1.11:33036    3.121.18.47:https
-         cubic wscale:7,7 rto:372 rtt:168.408/2.044 ato:40 mss:1448 pmtu:1500 rcvmss:1448 advmss:1448 cwnd:10 bytes_sent:27500 bytes_acked:27501 bytes_received:1386524 segs_out:10990 segs_in:11037 data_segs_out:303 data_segs_in:3414 send 688kbps lastsnd:125776 lastrcv:9640 lastack:22760 pacing_rate 1.38Mbps delivery_rate 482kbps delivered:304 app_limited busy:43024ms rcv_rtt:3345.12 rcv_space:62431 rcv_ssthresh:760472 minrtt:168.867

disco/disco_fuzzer.go

@@ -1,7 +1,6 @@
 // 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.
-//go:build gofuzz
 // +build gofuzz
 
 package disco

go.mod

@@ -3,53 +3,48 @@ module tailscale.com
 go 1.16
 
 require (
-	github.com/alexbrainman/sspi v0.0.0-20210105120005-909beea2cc74
-	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
-	github.com/aws/aws-sdk-go v1.38.52
-	github.com/coreos/go-iptables v0.6.0
-	github.com/creack/pty v1.1.9
-	github.com/dave/jennifer v1.4.1
-	github.com/frankban/quicktest v1.13.0
-	github.com/gliderlabs/ssh v0.3.2
+	github.com/alexbrainman/sspi v0.0.0-20180613141037-e580b900e9f5
+	github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239 // indirect
+	github.com/coreos/go-iptables v0.4.5
+	github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 // indirect
+	github.com/frankban/quicktest v1.12.1
+	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 v1.2.5
-	github.com/godbus/dbus/v5 v5.0.4
-	github.com/google/go-cmp v0.5.6
-	github.com/google/goexpect v0.0.0-20210430020637-ab937bf7fd6f
-	github.com/google/uuid v1.1.2
-	github.com/goreleaser/nfpm v1.10.3
-	github.com/iancoleman/strcase v0.2.0
-	github.com/insomniacslk/dhcp v0.0.0-20210621130208-1cac67f12b1e
-	github.com/jsimonetti/rtnetlink v0.0.0-20210525051524-4cc836578190
+	github.com/go-ole/go-ole v1.2.4
+	github.com/godbus/dbus/v5 v5.0.3
+	github.com/google/go-cmp v0.5.5
+	github.com/goreleaser/nfpm v1.1.10
+	github.com/jsimonetti/rtnetlink v0.0.0-20210212075122-66c871082f2b
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
-	github.com/klauspost/compress v1.12.2
-	github.com/mdlayher/netlink v1.4.1
-	github.com/mdlayher/sdnotify v0.0.0-20210228150836-ea3ec207d697
-	github.com/miekg/dns v1.1.42
-	github.com/mitchellh/go-ps v1.0.0
-	github.com/pborman/getopt v1.1.0
+	github.com/klauspost/compress v1.10.10
+	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/pkg/sftp v1.13.0
-	github.com/tailscale/certstore v0.0.0-20210528134328-066c94b793d3
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/tailscale/depaware v0.0.0-20201214215404-77d1e9757027
-	github.com/tailscale/goupnp v1.0.1-0.20210804011211-c64d0f06ea05
-	github.com/tailscale/hujson v0.0.0-20200924210142-dde312d0d6a2
+	github.com/tailscale/wireguard-go v0.0.0-20210510192616-d1aa5623121d
 	github.com/tcnksm/go-httpstat v0.2.0
 	github.com/toqueteos/webbrowser v1.2.0
 	go4.org/mem v0.0.0-20201119185036-c04c5a6ff174
-	golang.org/x/crypto v0.0.0-20210616213533-5ff15b29337e
-	golang.org/x/net v0.0.0-20210614182718-04defd469f4e
+	golang.org/x/crypto v0.0.0-20210317152858-513c2a44f670
+	golang.org/x/net v0.0.0-20210510120150-4163338589ed
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
-	golang.org/x/sys v0.0.0-20210817190340-bfb29a6856f2
-	golang.org/x/term v0.0.0-20210503060354-a79de5458b56
-	golang.org/x/time v0.0.0-20210611083556-38a9dc6acbc6
-	golang.org/x/tools v0.1.2
-	golang.zx2c4.com/wireguard v0.0.0-20210624150102-15b24b6179e0
-	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20210803171230-4253848d036c // indirect
-	golang.zx2c4.com/wireguard/windows v0.3.16
-	honnef.co/go/tools v0.1.4
-	inet.af/netaddr v0.0.0-20210721214506-ce7a8ad02cc1
-	inet.af/netstack v0.0.0-20210622165351-29b14ebc044e
-	inet.af/peercred v0.0.0-20210318190834-4259e17bb763
+	golang.org/x/sys v0.0.0-20210510120138-977fb7262007
+	golang.org/x/term v0.0.0-20210317153231-de623e64d2a6
+	golang.org/x/time v0.0.0-20210220033141-f8bda1e9f3ba
+	golang.org/x/tools v0.1.0
+	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 v0.0.0-20210515010201-ad03edc7c841
+	inet.af/netstack v0.0.0-20210317161235-a1bf4e56ef22
+	inet.af/peercred v0.0.0-20210302202138-56e694897155
 	inet.af/wf v0.0.0-20210516214145-a5343001b756
+	rsc.io/goversion v1.2.0
 )
+
+replace github.com/github/certstore => github.com/cyolosecurity/certstore v0.0.0-20200922073901-ece7f1d353c2

hostinfo/hostinfo.go

@@ -1,193 +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.
-
-// Package hostinfo answers questions about the host environment that Tailscale is
-// running on.
-package hostinfo
-
-import (
-	"io"
-	"os"
-	"path/filepath"
-	"runtime"
-	"sync/atomic"
-
-	"go4.org/mem"
-	"tailscale.com/tailcfg"
-	"tailscale.com/util/dnsname"
-	"tailscale.com/util/lineread"
-	"tailscale.com/version"
-)
-
-var osVersion func() string // non-nil on some platforms
-
-// New returns a partially populated Hostinfo for the current host.
-func New() *tailcfg.Hostinfo {
-	hostname, _ := os.Hostname()
-	hostname = dnsname.FirstLabel(hostname)
-	var osv string
-	if osVersion != nil {
-		osv = osVersion()
-	}
-	return &tailcfg.Hostinfo{
-		IPNVersion:  version.Long,
-		Hostname:    hostname,
-		OS:          version.OS(),
-		OSVersion:   osv,
-		Package:     packageType(),
-		GoArch:      runtime.GOARCH,
-		DeviceModel: deviceModel(),
-	}
-}
-
-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)
-	case "linux":
-		// Report whether this is in a snap.
-		// See https://snapcraft.io/docs/environment-variables
-		// We just look at two somewhat arbitrarily.
-		if os.Getenv("SNAP_NAME") != "" && os.Getenv("SNAP") != "" {
-			return "snap"
-		}
-	}
-	return ""
-}
-
-// EnvType represents a known environment type.
-// The empty string, the default, means unknown.
-type EnvType string
-
-const (
-	KNative         = EnvType("kn")
-	AWSLambda       = EnvType("lm")
-	Heroku          = EnvType("hr")
-	AzureAppService = EnvType("az")
-	AWSFargate      = EnvType("fg")
-	FlyDotIo        = EnvType("fly")
-)
-
-var envType atomic.Value // of EnvType
-
-func GetEnvType() EnvType {
-	if e, ok := envType.Load().(EnvType); ok {
-		return e
-	}
-	e := getEnvType()
-	envType.Store(e)
-	return e
-}
-
-var deviceModelAtomic atomic.Value // of string
-
-// SetDeviceModel sets the device model for use in Hostinfo updates.
-func SetDeviceModel(model string) { deviceModelAtomic.Store(model) }
-
-func deviceModel() string {
-	s, _ := deviceModelAtomic.Load().(string)
-	return s
-}
-
-func getEnvType() EnvType {
-	if inKnative() {
-		return KNative
-	}
-	if inAWSLambda() {
-		return AWSLambda
-	}
-	if inHerokuDyno() {
-		return Heroku
-	}
-	if inAzureAppService() {
-		return AzureAppService
-	}
-	if inAWSFargate() {
-		return AWSFargate
-	}
-	if inFlyDotIo() {
-		return FlyDotIo
-	}
-	return ""
-}
-
-// inContainer reports whether we're running in a container.
-func inContainer() bool {
-	if runtime.GOOS != "linux" {
-		return false
-	}
-	var ret bool
-	lineread.File("/proc/1/cgroup", func(line []byte) error {
-		if mem.Contains(mem.B(line), mem.S("/docker/")) ||
-			mem.Contains(mem.B(line), mem.S("/lxc/")) {
-			ret = true
-			return io.EOF // arbitrary non-nil error to stop loop
-		}
-		return nil
-	})
-	lineread.File("/proc/mounts", func(line []byte) error {
-		if mem.Contains(mem.B(line), mem.S("fuse.lxcfs")) {
-			ret = true
-			return io.EOF
-		}
-		return nil
-	})
-	return ret
-}
-
-func inKnative() bool {
-	// https://cloud.google.com/run/docs/reference/container-contract#env-vars
-	if os.Getenv("K_REVISION") != "" && os.Getenv("K_CONFIGURATION") != "" &&
-		os.Getenv("K_SERVICE") != "" && os.Getenv("PORT") != "" {
-		return true
-	}
-	return false
-}
-
-func inAWSLambda() bool {
-	// https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html
-	if os.Getenv("AWS_LAMBDA_FUNCTION_NAME") != "" &&
-		os.Getenv("AWS_LAMBDA_FUNCTION_VERSION") != "" &&
-		os.Getenv("AWS_LAMBDA_INITIALIZATION_TYPE") != "" &&
-		os.Getenv("AWS_LAMBDA_RUNTIME_API") != "" {
-		return true
-	}
-	return false
-}
-
-func inHerokuDyno() bool {
-	// https://devcenter.heroku.com/articles/dynos#local-environment-variables
-	if os.Getenv("PORT") != "" && os.Getenv("DYNO") != "" {
-		return true
-	}
-	return false
-}
-
-func inAzureAppService() bool {
-	if os.Getenv("APPSVC_RUN_ZIP") != "" && os.Getenv("WEBSITE_STACK") != "" &&
-		os.Getenv("WEBSITE_AUTH_AUTO_AAD") != "" {
-		return true
-	}
-	return false
-}
-
-func inAWSFargate() bool {
-	if os.Getenv("AWS_EXECUTION_ENV") == "AWS_ECS_FARGATE" {
-		return true
-	}
-	return false
-}
-
-func inFlyDotIo() bool {
-	if os.Getenv("FLY_APP_NAME") != "" && os.Getenv("FLY_REGION") != "" {
-		return true
-	}
-	return false
-}

hostinfo/hostinfo_test.go

@@ -1,29 +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.
-
-package hostinfo
-
-import (
-	"encoding/json"
-	"testing"
-)
-
-func TestNew(t *testing.T) {
-	hi := New()
-	if hi == nil {
-		t.Fatal("no Hostinfo")
-	}
-	j, err := json.MarshalIndent(hi, "  ", "")
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Logf("Got: %s", j)
-}
-
-func TestOSVersion(t *testing.T) {
-	if osVersion == nil {
-		t.Skip("not available for OS")
-	}
-	t.Logf("Got: %#q", osVersion())
-}

internal/deephash/deephash.go

@@ -0,0 +1,174 @@
+// 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 deephash hashes a Go value recursively, in a predictable
+// order, without looping.
+package deephash
+
+import (
+	"bufio"
+	"crypto/sha256"
+	"fmt"
+	"reflect"
+
+	"inet.af/netaddr"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/wgkey"
+)
+
+func Hash(v ...interface{}) string {
+	h := sha256.New()
+	// 64 matches the chunk size in crypto/sha256/sha256.go
+	b := bufio.NewWriterSize(h, 64)
+	Print(b, v)
+	b.Flush()
+	return fmt.Sprintf("%x", h.Sum(nil))
+}
+
+// UpdateHash sets last to the hash of v and reports whether its value changed.
+func UpdateHash(last *string, v ...interface{}) (changed bool) {
+	sig := Hash(v)
+	if *last != sig {
+		*last = sig
+		return true
+	}
+	return false
+}
+
+func Print(w *bufio.Writer, v ...interface{}) {
+	print(w, reflect.ValueOf(v), make(map[uintptr]bool))
+}
+
+var (
+	netaddrIPType       = reflect.TypeOf(netaddr.IP{})
+	netaddrIPPrefix     = reflect.TypeOf(netaddr.IPPrefix{})
+	wgkeyKeyType        = reflect.TypeOf(wgkey.Key{})
+	wgkeyPrivateType    = reflect.TypeOf(wgkey.Private{})
+	tailcfgDiscoKeyType = reflect.TypeOf(tailcfg.DiscoKey{})
+)
+
+func print(w *bufio.Writer, v reflect.Value, visited map[uintptr]bool) {
+	if !v.IsValid() {
+		return
+	}
+
+	// Special case some common types.
+	if v.CanInterface() {
+		switch v.Type() {
+		case netaddrIPType:
+			var b []byte
+			var err error
+			if v.CanAddr() {
+				x := v.Addr().Interface().(*netaddr.IP)
+				b, err = x.MarshalText()
+			} else {
+				x := v.Interface().(netaddr.IP)
+				b, err = x.MarshalText()
+			}
+			if err == nil {
+				w.Write(b)
+				return
+			}
+		case netaddrIPPrefix:
+			var b []byte
+			var err error
+			if v.CanAddr() {
+				x := v.Addr().Interface().(*netaddr.IPPrefix)
+				b, err = x.MarshalText()
+			} else {
+				x := v.Interface().(netaddr.IPPrefix)
+				b, err = x.MarshalText()
+			}
+			if err == nil {
+				w.Write(b)
+				return
+			}
+		case wgkeyKeyType:
+			if v.CanAddr() {
+				x := v.Addr().Interface().(*wgkey.Key)
+				w.Write(x[:])
+			} else {
+				x := v.Interface().(wgkey.Key)
+				w.Write(x[:])
+			}
+			return
+		case wgkeyPrivateType:
+			if v.CanAddr() {
+				x := v.Addr().Interface().(*wgkey.Private)
+				w.Write(x[:])
+			} else {
+				x := v.Interface().(wgkey.Private)
+				w.Write(x[:])
+			}
+			return
+		case tailcfgDiscoKeyType:
+			if v.CanAddr() {
+				x := v.Addr().Interface().(*tailcfg.DiscoKey)
+				w.Write(x[:])
+			} else {
+				x := v.Interface().(tailcfg.DiscoKey)
+				w.Write(x[:])
+			}
+			return
+		}
+	}
+
+	// Generic handling.
+	switch v.Kind() {
+	default:
+		panic(fmt.Sprintf("unhandled kind %v for type %v", v.Kind(), v.Type()))
+	case reflect.Ptr:
+		ptr := v.Pointer()
+		if visited[ptr] {
+			return
+		}
+		visited[ptr] = true
+		print(w, v.Elem(), visited)
+		return
+	case reflect.Struct:
+		w.WriteString("struct{\n")
+		for i, n := 0, v.NumField(); i < n; i++ {
+			fmt.Fprintf(w, " [%d]: ", i)
+			print(w, v.Field(i), visited)
+			w.WriteString("\n")
+		}
+		w.WriteString("}\n")
+	case reflect.Slice, reflect.Array:
+		if v.Type().Elem().Kind() == reflect.Uint8 && v.CanInterface() {
+			fmt.Fprintf(w, "%q", v.Interface())
+			return
+		}
+		fmt.Fprintf(w, "[%d]{\n", v.Len())
+		for i, ln := 0, v.Len(); i < ln; i++ {
+			fmt.Fprintf(w, " [%d]: ", i)
+			print(w, v.Index(i), visited)
+			w.WriteString("\n")
+		}
+		w.WriteString("}\n")
+	case reflect.Interface:
+		print(w, v.Elem(), visited)
+	case reflect.Map:
+		sm := newSortedMap(v)
+		fmt.Fprintf(w, "map[%d]{\n", len(sm.Key))
+		for i, k := range sm.Key {
+			print(w, k, visited)
+			w.WriteString(": ")
+			print(w, sm.Value[i], visited)
+			w.WriteString("\n")
+		}
+		w.WriteString("}\n")
+	case reflect.String:
+		w.WriteString(v.String())
+	case reflect.Bool:
+		fmt.Fprintf(w, "%v", v.Bool())
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		fmt.Fprintf(w, "%v", v.Int())
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		fmt.Fprintf(w, "%v", v.Uint())
+	case reflect.Float32, reflect.Float64:
+		fmt.Fprintf(w, "%v", v.Float())
+	case reflect.Complex64, reflect.Complex128:
+		fmt.Fprintf(w, "%v", v.Complex())
+	}
+}

internal/deephash/deephash_test.go

@@ -0,0 +1,72 @@
+// 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 deephash
+
+import (
+	"testing"
+
+	"inet.af/netaddr"
+	"tailscale.com/tailcfg"
+	"tailscale.com/util/dnsname"
+	"tailscale.com/wgengine/router"
+	"tailscale.com/wgengine/wgcfg"
+)
+
+func TestDeepPrint(t *testing.T) {
+	// v contains the types of values we care about for our current callers.
+	// Mostly we're just testing that we don't panic on handled types.
+	v := getVal()
+
+	hash1 := Hash(v)
+	t.Logf("hash: %v", hash1)
+	for i := 0; i < 20; i++ {
+		hash2 := Hash(getVal())
+		if hash1 != hash2 {
+			t.Error("second hash didn't match")
+		}
+	}
+}
+
+func getVal() []interface{} {
+	return []interface{}{
+		&wgcfg.Config{
+			Name:      "foo",
+			Addresses: []netaddr.IPPrefix{netaddr.IPPrefixFrom(netaddr.IPFrom16([16]byte{3: 3}), 5)},
+			Peers: []wgcfg.Peer{
+				{
+					Endpoints: wgcfg.Endpoints{
+						IPPorts: wgcfg.NewIPPortSet(netaddr.MustParseIPPort("42.42.42.42:5")),
+					},
+				},
+			},
+		},
+		&router.Config{
+			Routes: []netaddr.IPPrefix{
+				netaddr.MustParseIPPrefix("1.2.3.0/24"),
+				netaddr.MustParseIPPrefix("1234::/64"),
+			},
+		},
+		map[dnsname.FQDN][]netaddr.IP{
+			dnsname.FQDN("a."): {netaddr.MustParseIP("1.2.3.4"), netaddr.MustParseIP("4.3.2.1")},
+			dnsname.FQDN("b."): {netaddr.MustParseIP("8.8.8.8"), netaddr.MustParseIP("9.9.9.9")},
+		},
+		map[dnsname.FQDN][]netaddr.IPPort{
+			dnsname.FQDN("a."): {netaddr.MustParseIPPort("1.2.3.4:11"), netaddr.MustParseIPPort("4.3.2.1:22")},
+			dnsname.FQDN("b."): {netaddr.MustParseIPPort("8.8.8.8:11"), netaddr.MustParseIPPort("9.9.9.9:22")},
+		},
+		map[tailcfg.DiscoKey]bool{
+			{1: 1}: true,
+			{1: 2}: false,
+		},
+	}
+}
+
+func BenchmarkHash(b *testing.B) {
+	b.ReportAllocs()
+	v := getVal()
+	for i := 0; i < b.N; i++ {
+		Hash(v)
+	}
+}

internal/deephash/fmtsort.go

@@ -0,0 +1,224 @@
+// 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.
+
+// and
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This is a slightly modified fork of Go's src/internal/fmtsort/sort.go
+
+package deephash
+
+import (
+	"reflect"
+	"sort"
+)
+
+// Note: Throughout this package we avoid calling reflect.Value.Interface as
+// it is not always legal to do so and it's easier to avoid the issue than to face it.
+
+// sortedMap represents a map's keys and values. The keys and values are
+// aligned in index order: Value[i] is the value in the map corresponding to Key[i].
+type sortedMap struct {
+	Key   []reflect.Value
+	Value []reflect.Value
+}
+
+func (o *sortedMap) Len() int           { return len(o.Key) }
+func (o *sortedMap) Less(i, j int) bool { return compare(o.Key[i], o.Key[j]) < 0 }
+func (o *sortedMap) Swap(i, j int) {
+	o.Key[i], o.Key[j] = o.Key[j], o.Key[i]
+	o.Value[i], o.Value[j] = o.Value[j], o.Value[i]
+}
+
+// Sort accepts a map and returns a sortedMap that has the same keys and
+// values but in a stable sorted order according to the keys, modulo issues
+// raised by unorderable key values such as NaNs.
+//
+// The ordering rules are more general than with Go's < operator:
+//
+//  - when applicable, nil compares low
+//  - ints, floats, and strings order by <
+//  - NaN compares less than non-NaN floats
+//  - bool compares false before true
+//  - complex compares real, then imag
+//  - pointers compare by machine address
+//  - channel values compare by machine address
+//  - structs compare each field in turn
+//  - arrays compare each element in turn.
+//    Otherwise identical arrays compare by length.
+//  - interface values compare first by reflect.Type describing the concrete type
+//    and then by concrete value as described in the previous rules.
+//
+func newSortedMap(mapValue reflect.Value) *sortedMap {
+	if mapValue.Type().Kind() != reflect.Map {
+		return nil
+	}
+	// Note: this code is arranged to not panic even in the presence
+	// of a concurrent map update. The runtime is responsible for
+	// yelling loudly if that happens. See issue 33275.
+	n := mapValue.Len()
+	key := make([]reflect.Value, 0, n)
+	value := make([]reflect.Value, 0, n)
+	iter := mapValue.MapRange()
+	for iter.Next() {
+		key = append(key, iter.Key())
+		value = append(value, iter.Value())
+	}
+	sorted := &sortedMap{
+		Key:   key,
+		Value: value,
+	}
+	sort.Stable(sorted)
+	return sorted
+}
+
+// compare compares two values of the same type. It returns -1, 0, 1
+// according to whether a > b (1), a == b (0), or a < b (-1).
+// If the types differ, it returns -1.
+// See the comment on Sort for the comparison rules.
+func compare(aVal, bVal reflect.Value) int {
+	aType, bType := aVal.Type(), bVal.Type()
+	if aType != bType {
+		return -1 // No good answer possible, but don't return 0: they're not equal.
+	}
+	switch aVal.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		a, b := aVal.Int(), bVal.Int()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		a, b := aVal.Uint(), bVal.Uint()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.String:
+		a, b := aVal.String(), bVal.String()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Float32, reflect.Float64:
+		return floatCompare(aVal.Float(), bVal.Float())
+	case reflect.Complex64, reflect.Complex128:
+		a, b := aVal.Complex(), bVal.Complex()
+		if c := floatCompare(real(a), real(b)); c != 0 {
+			return c
+		}
+		return floatCompare(imag(a), imag(b))
+	case reflect.Bool:
+		a, b := aVal.Bool(), bVal.Bool()
+		switch {
+		case a == b:
+			return 0
+		case a:
+			return 1
+		default:
+			return -1
+		}
+	case reflect.Ptr:
+		a, b := aVal.Pointer(), bVal.Pointer()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Chan:
+		if c, ok := nilCompare(aVal, bVal); ok {
+			return c
+		}
+		ap, bp := aVal.Pointer(), bVal.Pointer()
+		switch {
+		case ap < bp:
+			return -1
+		case ap > bp:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Struct:
+		for i := 0; i < aVal.NumField(); i++ {
+			if c := compare(aVal.Field(i), bVal.Field(i)); c != 0 {
+				return c
+			}
+		}
+		return 0
+	case reflect.Array:
+		for i := 0; i < aVal.Len(); i++ {
+			if c := compare(aVal.Index(i), bVal.Index(i)); c != 0 {
+				return c
+			}
+		}
+		return 0
+	case reflect.Interface:
+		if c, ok := nilCompare(aVal, bVal); ok {
+			return c
+		}
+		c := compare(reflect.ValueOf(aVal.Elem().Type()), reflect.ValueOf(bVal.Elem().Type()))
+		if c != 0 {
+			return c
+		}
+		return compare(aVal.Elem(), bVal.Elem())
+	default:
+		// Certain types cannot appear as keys (maps, funcs, slices), but be explicit.
+		panic("bad type in compare: " + aType.String())
+	}
+}
+
+// nilCompare checks whether either value is nil. If not, the boolean is false.
+// If either value is nil, the boolean is true and the integer is the comparison
+// value. The comparison is defined to be 0 if both are nil, otherwise the one
+// nil value compares low. Both arguments must represent a chan, func,
+// interface, map, pointer, or slice.
+func nilCompare(aVal, bVal reflect.Value) (int, bool) {
+	if aVal.IsNil() {
+		if bVal.IsNil() {
+			return 0, true
+		}
+		return -1, true
+	}
+	if bVal.IsNil() {
+		return 1, true
+	}
+	return 0, false
+}
+
+// floatCompare compares two floating-point values. NaNs compare low.
+func floatCompare(a, b float64) int {
+	switch {
+	case isNaN(a):
+		return -1 // No good answer if b is a NaN so don't bother checking.
+	case isNaN(b):
+		return 1
+	case a < b:
+		return -1
+	case a > b:
+		return 1
+	}
+	return 0
+}
+
+func isNaN(a float64) bool {
+	return a != a
+}

ipn/handle.go

@@ -156,7 +156,7 @@ func (h *Handle) Expiry() time.Time {
 }
 
 func (h *Handle) AdminPageURL() string {
-	return h.prefsCache.AdminPageURL()
+	return h.prefsCache.ControlURLOrDefault() + "/admin/machines"
 }
 
 func (h *Handle) StartLoginInteractive() {

ipn/ipnlocal/local.go

@@ -29,7 +29,7 @@ import (
 	"tailscale.com/client/tailscale/apitype"
 	"tailscale.com/control/controlclient"
 	"tailscale.com/health"
-	"tailscale.com/hostinfo"
+	"tailscale.com/internal/deephash"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/ipn/policy"
@@ -39,20 +39,16 @@ import (
 	"tailscale.com/paths"
 	"tailscale.com/portlist"
 	"tailscale.com/tailcfg"
-	"tailscale.com/types/dnstype"
 	"tailscale.com/types/empty"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/netmap"
 	"tailscale.com/types/persist"
-	"tailscale.com/types/preftype"
 	"tailscale.com/types/wgkey"
-	"tailscale.com/util/deephash"
 	"tailscale.com/util/dnsname"
 	"tailscale.com/util/osshare"
 	"tailscale.com/util/systemd"
 	"tailscale.com/version"
-	"tailscale.com/version/distro"
 	"tailscale.com/wgengine"
 	"tailscale.com/wgengine/filter"
 	"tailscale.com/wgengine/router"
@@ -97,7 +93,7 @@ type LocalBackend struct {
 	serverURL             string           // tailcontrol URL
 	newDecompressor       func() (controlclient.Decompressor, error)
 
-	filterHash deephash.Sum
+	filterHash string
 
 	// The mutex protects the following elements.
 	mu             sync.Mutex
@@ -181,7 +177,6 @@ func NewLocalBackend(logf logger.Logf, logid string, store ipn.StateStore, e wge
 		gotPortPollRes: make(chan struct{}),
 	}
 	b.statusChanged = sync.NewCond(&b.statusLock)
-	b.e.SetStatusCallback(b.setWgengineStatus)
 
 	linkMon := e.GetLinkMonitor()
 	b.prevIfState = linkMon.InterfaceState()
@@ -217,15 +212,6 @@ func (b *LocalBackend) SetDirectFileRoot(dir string) {
 	b.directFileRoot = dir
 }
 
-// b.mu must be held.
-func (b *LocalBackend) maybePauseControlClientLocked() {
-	if b.cc == nil {
-		return
-	}
-	networkUp := b.prevIfState.AnyInterfaceUp()
-	b.cc.SetPaused((b.state == ipn.Stopped && b.netMap != nil) || !networkUp)
-}
-
 // linkChange is our link monitor callback, called whenever the network changes.
 // major is whether ifst is different than earlier.
 func (b *LocalBackend) linkChange(major bool, ifst *interfaces.State) {
@@ -234,7 +220,11 @@ func (b *LocalBackend) linkChange(major bool, ifst *interfaces.State) {
 
 	hadPAC := b.prevIfState.HasPAC()
 	b.prevIfState = ifst
-	b.maybePauseControlClientLocked()
+
+	networkUp := ifst.AnyInterfaceUp()
+	if b.cc != nil {
+		go b.cc.SetPaused((b.state == ipn.Stopped && b.netMap != nil) || !networkUp)
+	}
 
 	// If the PAC-ness of the network changed, reconfig wireguard+route to
 	// add/remove subnets.
@@ -252,10 +242,10 @@ func (b *LocalBackend) linkChange(major bool, ifst *interfaces.State) {
 	// need updating to tweak default routes.
 	b.updateFilter(b.netMap, b.prefs)
 
-	if peerAPIListenAsync && b.netMap != nil && b.state == ipn.Running {
+	if runtime.GOOS == "windows" && b.netMap != nil && b.state == ipn.Running {
 		want := len(b.netMap.Addresses)
+		b.logf("linkChange: peerAPIListeners too low; trying again")
 		if len(b.peerAPIListeners) < want {
-			b.logf("linkChange: peerAPIListeners too low; trying again")
 			go b.initPeerAPIListener()
 		}
 	}
@@ -333,7 +323,6 @@ func (b *LocalBackend) updateStatus(sb *ipnstate.StatusBuilder, extraLocked func
 		s.AuthURL = b.authURLSticky
 		if b.netMap != nil {
 			s.MagicDNSSuffix = b.netMap.MagicDNSSuffix()
-			s.CertDomains = append([]string(nil), b.netMap.DNS.CertDomains...)
 		}
 	})
 	sb.MutateSelfStatus(func(ss *ipnstate.PeerStatus) {
@@ -462,13 +451,6 @@ func (b *LocalBackend) setClientStatus(st controlclient.Status) {
 	// Lock b once and do only the things that require locking.
 	b.mu.Lock()
 
-	if st.LogoutFinished != nil {
-		// Since we're logged out now, our netmap cache is invalid.
-		// Since st.NetMap==nil means "netmap is unchanged", there is
-		// no other way to represent this change.
-		b.setNetMapLocked(nil)
-	}
-
 	prefs := b.prefs
 	stateKey := b.stateKey
 	netMap := b.netMap
@@ -613,8 +595,8 @@ func (b *LocalBackend) setWgengineStatus(s *wgengine.Status, err error) {
 
 	if cc != nil {
 		cc.UpdateEndpoints(0, s.LocalAddrs)
-		b.stateMachine()
 	}
+	b.stateMachine()
 
 	b.statusLock.Lock()
 	b.statusChanged.Broadcast()
@@ -666,12 +648,6 @@ func (b *LocalBackend) getNewControlClientFunc() clientGen {
 // startIsNoopLocked reports whether a Start call on this LocalBackend
 // with the provided Start Options would be a useless no-op.
 //
-// TODO(apenwarr): we shouldn't need this.
-//  The state machine is now nearly clean enough where it can accept a new
-//  connection while in any state, not just Running, and on any platform.
-//  We'd want to add a few more tests to state_test.go to ensure this continues
-//  to work as expected.
-//
 // b.mu must be held.
 func (b *LocalBackend) startIsNoopLocked(opts ipn.Options) bool {
 	// Options has 5 fields; check all of them:
@@ -725,13 +701,12 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 		b.send(ipn.Notify{
 			State:         &state,
 			NetMap:        nm,
-			Prefs:         b.prefs,
 			LoginFinished: new(empty.Message),
 		})
 		return nil
 	}
 
-	hostinfo := hostinfo.New()
+	hostinfo := controlclient.NewHostinfo()
 	hostinfo.BackendLogID = b.backendLogID
 	hostinfo.FrontendLogID = opts.FrontendLogID
 
@@ -765,12 +740,6 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 		newPrefs := opts.UpdatePrefs
 		newPrefs.Persist = b.prefs.Persist
 		b.prefs = newPrefs
-
-		if opts.StateKey != "" {
-			if err := b.store.WriteState(opts.StateKey, b.prefs.ToBytes()); err != nil {
-				b.logf("failed to save UpdatePrefs state: %v", err)
-			}
-		}
 	}
 
 	wantRunning := b.prefs.WantRunning
@@ -784,6 +753,8 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 
 	b.inServerMode = b.prefs.ForceDaemon
 	b.serverURL = b.prefs.ControlURLOrDefault()
+	hostinfo.RoutableIPs = append(hostinfo.RoutableIPs, b.prefs.AdvertiseRoutes...)
+	hostinfo.RequestTags = append(hostinfo.RequestTags, b.prefs.AdvertiseTags...)
 	if b.inServerMode || runtime.GOOS == "windows" {
 		b.logf("Start: serverMode=%v", b.inServerMode)
 	}
@@ -850,7 +821,6 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 		DiscoPublicKey:       discoPublic,
 		DebugFlags:           debugFlags,
 		LinkMonitor:          b.e.GetLinkMonitor(),
-		Pinger:               b.e,
 
 		// Don't warn about broken Linux IP forwading when
 		// netstack is being used.
@@ -870,6 +840,7 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 	}
 
 	cc.SetStatusFunc(b.setClientStatus)
+	b.e.SetStatusCallback(b.setWgengineStatus)
 	b.e.SetNetInfoCallback(b.setNetInfo)
 
 	b.mu.Lock()
@@ -942,10 +913,10 @@ func (b *LocalBackend) updateFilter(netMap *netmap.NetworkMap, prefs *ipn.Prefs)
 			}
 		}
 	}
-	localNets, _ := localNetsB.IPSet()
-	logNets, _ := logNetsB.IPSet()
+	localNets := localNetsB.IPSet()
+	logNets := logNetsB.IPSet()
 
-	changed := deephash.Update(&b.filterHash, haveNetmap, addrs, packetFilter, localNets.Ranges(), logNets.Ranges(), shieldsUp)
+	changed := deephash.UpdateHash(&b.filterHash, haveNetmap, addrs, packetFilter, localNets.Ranges(), logNets.Ranges(), shieldsUp)
 	if !changed {
 		return
 	}
@@ -961,7 +932,7 @@ func (b *LocalBackend) updateFilter(netMap *netmap.NetworkMap, prefs *ipn.Prefs)
 		b.logf("netmap packet filter: (shields up)")
 		b.e.SetFilter(filter.NewShieldsUpFilter(localNets, logNets, oldFilter, b.logf))
 	} else {
-		b.logf("netmap packet filter: %v filters", len(packetFilter))
+		b.logf("netmap packet filter: %v", packetFilter)
 		b.e.SetFilter(filter.New(packetFilter, localNets, logNets, oldFilter, b.logf))
 	}
 }
@@ -985,44 +956,6 @@ var removeFromDefaultRoute = []netaddr.IPPrefix{
 	tsaddr.TailscaleULARange(),
 }
 
-// internalAndExternalInterfaces splits interface routes into "internal"
-// and "external" sets. Internal routes are those of virtual ethernet
-// network interfaces used by guest VMs and containers, such as WSL and
-// Docker.
-//
-// Given that "internal" routes don't leave the device, we choose to
-// trust them more, allowing access to them when an Exit Node is enabled.
-func internalAndExternalInterfaces() (internal, external []netaddr.IPPrefix, err error) {
-	if err := interfaces.ForeachInterfaceAddress(func(iface interfaces.Interface, pfx netaddr.IPPrefix) {
-		if tsaddr.IsTailscaleIP(pfx.IP()) {
-			return
-		}
-		if pfx.IsSingleIP() {
-			return
-		}
-		if runtime.GOOS == "windows" {
-			// Windows Hyper-V prefixes all MAC addresses with 00:15:5d.
-			// https://docs.microsoft.com/en-us/troubleshoot/windows-server/virtualization/default-limit-256-dynamic-mac-addresses
-			//
-			// This includes WSL2 vEthernet.
-			// Importantly: by default WSL2 /etc/resolv.conf points to
-			// a stub resolver running on the host vEthernet IP.
-			// So enabling exit nodes with the default tailnet
-			// configuration breaks WSL2 DNS without this.
-			mac := iface.Interface.HardwareAddr
-			if len(mac) == 6 && mac[0] == 0x00 && mac[1] == 0x15 && mac[2] == 0x5d {
-				internal = append(internal, pfx)
-				return
-			}
-		}
-		external = append(external, pfx)
-	}); err != nil {
-		return nil, nil, err
-	}
-
-	return internal, external, nil
-}
-
 func interfaceRoutes() (ips *netaddr.IPSet, hostIPs []netaddr.IP, err error) {
 	var b netaddr.IPSetBuilder
 	if err := interfaces.ForeachInterfaceAddress(func(_ interfaces.Interface, pfx netaddr.IPPrefix) {
@@ -1038,8 +971,7 @@ func interfaceRoutes() (ips *netaddr.IPSet, hostIPs []netaddr.IP, err error) {
 		return nil, nil, err
 	}
 
-	ipSet, _ := b.IPSet()
-	return ipSet, hostIPs, nil
+	return b.IPSet(), hostIPs, nil
 }
 
 // shrinkDefaultRoute returns an IPSet representing the IPs in route,
@@ -1070,7 +1002,7 @@ func shrinkDefaultRoute(route netaddr.IPPrefix) (*netaddr.IPSet, error) {
 	for _, pfx := range removeFromDefaultRoute {
 		b.RemovePrefix(pfx)
 	}
-	return b.IPSet()
+	return b.IPSet(), nil
 }
 
 // dnsCIDRsEqual determines whether two CIDR lists are equal
@@ -1579,6 +1511,7 @@ func (b *LocalBackend) setPrefsLockedOnEntry(caller string, newp *ipn.Prefs) {
 
 	oldHi := b.hostinfo
 	newHi := oldHi.Clone()
+	newHi.RoutableIPs = append([]netaddr.IPPrefix(nil), b.prefs.AdvertiseRoutes...)
 	applyPrefsToHostinfo(newHi, newp)
 	b.hostinfo = newHi
 	hostInfoChanged := !oldHi.Equal(newHi)
@@ -1761,66 +1694,11 @@ func (b *LocalBackend) authReconfig() {
 
 	rcfg := b.routerConfig(cfg, uc)
 
-	dcfg := dns.Config{
-		Routes: map[dnsname.FQDN][]netaddr.IPPort{},
-		Hosts:  map[dnsname.FQDN][]netaddr.IP{},
-	}
-
-	// Populate MagicDNS records. We do this unconditionally so that
-	// quad-100 can always respond to MagicDNS queries, even if the OS
-	// isn't configured to make MagicDNS resolution truly
-	// magic. Details in
-	// https://github.com/tailscale/tailscale/issues/1886.
-	set := func(name string, addrs []netaddr.IPPrefix) {
-		if len(addrs) == 0 || name == "" {
-			return
-		}
-		fqdn, err := dnsname.ToFQDN(name)
-		if err != nil {
-			return // TODO: propagate error?
-		}
-		var ips []netaddr.IP
-		for _, addr := range addrs {
-			// Remove IPv6 addresses for now, as we don't
-			// guarantee that the peer node actually can speak
-			// IPv6 correctly.
-			//
-			// https://github.com/tailscale/tailscale/issues/1152
-			// tracks adding the right capability reporting to
-			// enable AAAA in MagicDNS.
-			if addr.IP().Is6() {
-				continue
-			}
-			ips = append(ips, addr.IP())
-		}
-		dcfg.Hosts[fqdn] = ips
-	}
-	set(nm.Name, nm.Addresses)
-	for _, peer := range nm.Peers {
-		set(peer.Name, peer.Addresses)
-	}
-	for _, rec := range nm.DNS.ExtraRecords {
-		switch rec.Type {
-		case "", "A", "AAAA":
-			// Treat these all the same for now: infer from the value
-		default:
-			// TODO: more
-			continue
-		}
-		ip, err := netaddr.ParseIP(rec.Value)
-		if err != nil {
-			// Ignore.
-			continue
-		}
-		fqdn, err := dnsname.ToFQDN(rec.Name)
-		if err != nil {
-			continue
-		}
-		dcfg.Hosts[fqdn] = append(dcfg.Hosts[fqdn], ip)
-	}
+	var dcfg dns.Config
 
+	// If CorpDNS is false, dcfg remains the zero value.
 	if uc.CorpDNS {
-		addDefault := func(resolvers []dnstype.Resolver) {
+		addDefault := func(resolvers []tailcfg.DNSResolver) {
 			for _, resolver := range resolvers {
 				res, err := parseResolver(resolver)
 				if err != nil {
@@ -1832,22 +1710,14 @@ func (b *LocalBackend) authReconfig() {
 		}
 
 		addDefault(nm.DNS.Resolvers)
+		if len(nm.DNS.Routes) > 0 {
+			dcfg.Routes = map[dnsname.FQDN][]netaddr.IPPort{}
+		}
 		for suffix, resolvers := range nm.DNS.Routes {
 			fqdn, err := dnsname.ToFQDN(suffix)
 			if err != nil {
 				b.logf("[unexpected] non-FQDN route suffix %q", suffix)
 			}
-
-			// Create map entry even if len(resolvers) == 0; Issue 2706.
-			// This lets the control plane send ExtraRecords for which we
-			// can authoritatively answer "name not exists" for when the
-			// control plane also sends this explicit but empty route
-			// making it as something we handle.
-			//
-			// While we're already populating it, might as well size the
-			// slice appropriately.
-			dcfg.Routes[fqdn] = make([]netaddr.IPPort, 0, len(resolvers))
-
 			for _, resolver := range resolvers {
 				res, err := parseResolver(resolver)
 				if err != nil {
@@ -1864,9 +1734,36 @@ func (b *LocalBackend) authReconfig() {
 			}
 			dcfg.SearchDomains = append(dcfg.SearchDomains, fqdn)
 		}
+		set := func(name string, addrs []netaddr.IPPrefix) {
+			if len(addrs) == 0 || name == "" {
+				return
+			}
+			fqdn, err := dnsname.ToFQDN(name)
+			if err != nil {
+				return // TODO: propagate error?
+			}
+			var ips []netaddr.IP
+			for _, addr := range addrs {
+				// Remove IPv6 addresses for now, as we don't
+				// guarantee that the peer node actually can speak
+				// IPv6 correctly.
+				//
+				// https://github.com/tailscale/tailscale/issues/1152
+				// tracks adding the right capability reporting to
+				// enable AAAA in MagicDNS.
+				if addr.IP().Is6() {
+					continue
+				}
+				ips = append(ips, addr.IP())
+			}
+			dcfg.Hosts[fqdn] = ips
+		}
 		if nm.DNS.Proxied { // actually means "enable MagicDNS"
-			for _, dom := range magicDNSRootDomains(nm) {
-				dcfg.Routes[dom] = nil // resolve internally with dcfg.Hosts
+			dcfg.AuthoritativeSuffixes = magicDNSRootDomains(nm)
+			dcfg.Hosts = map[dnsname.FQDN][]netaddr.IP{}
+			set(nm.Name, nm.Addresses)
+			for _, peer := range nm.Peers {
+				set(peer.Name, peer.Addresses)
 			}
 		}
 
@@ -1890,7 +1787,7 @@ func (b *LocalBackend) authReconfig() {
 			//
 			// https://github.com/tailscale/tailscale/issues/1713
 			addDefault(nm.DNS.FallbackResolvers)
-		case len(dcfg.Routes) == 0:
+		case len(dcfg.Routes) == 0 && len(dcfg.Hosts) == 0 && len(dcfg.AuthoritativeSuffixes) == 0:
 			// No settings requiring split DNS, no problem.
 		case version.OS() == "android":
 			// We don't support split DNS at all on Android yet.
@@ -1898,7 +1795,7 @@ func (b *LocalBackend) authReconfig() {
 		}
 	}
 
-	err = b.e.Reconfig(cfg, rcfg, &dcfg, nm.Debug)
+	err = b.e.Reconfig(cfg, rcfg, &dcfg)
 	if err == wgengine.ErrNoChanges {
 		return
 	}
@@ -1907,7 +1804,7 @@ func (b *LocalBackend) authReconfig() {
 	b.initPeerAPIListener()
 }
 
-func parseResolver(cfg dnstype.Resolver) (netaddr.IPPort, error) {
+func parseResolver(cfg tailcfg.DNSResolver) (netaddr.IPPort, error) {
 	ip, err := netaddr.ParseIP(cfg.Addr)
 	if err != nil {
 		return netaddr.IPPort{}, fmt.Errorf("[unexpected] non-IP resolver %q", cfg.Addr)
@@ -1918,9 +1815,8 @@ func parseResolver(cfg dnstype.Resolver) (netaddr.IPPort, error) {
 // tailscaleVarRoot returns the root directory of Tailscale's writable
 // storage area. (e.g. "/var/lib/tailscale")
 func tailscaleVarRoot() string {
-	switch runtime.GOOS {
-	case "ios", "android":
-		dir, _ := paths.AppSharedDir.Load().(string)
+	if runtime.GOOS == "ios" {
+		dir, _ := paths.IOSSharedDir.Load().(string)
 		return dir
 	}
 	stateFile := paths.DefaultTailscaledStateFile()
@@ -1964,26 +1860,10 @@ func (b *LocalBackend) closePeerAPIListenersLocked() {
 	b.peerAPIListeners = nil
 }
 
-// peerAPIListenAsync is whether the operating system requires that we
-// retry listening on the peerAPI ip/port for whatever reason.
-//
-// On Windows, see Issue 1620.
-// On Android, see Issue 1960.
-const peerAPIListenAsync = runtime.GOOS == "windows" || runtime.GOOS == "android"
-
 func (b *LocalBackend) initPeerAPIListener() {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 
-	if b.netMap == nil {
-		// We're called from authReconfig which checks that
-		// netMap is non-nil, but if a concurrent Logout,
-		// ResetForClientDisconnect, or Start happens when its
-		// mutex was released, the netMap could be
-		// nil'ed out (Issue 1996). Bail out early here if so.
-		return
-	}
-
 	if len(b.netMap.Addresses) == len(b.peerAPIListeners) {
 		allSame := true
 		for i, pln := range b.peerAPIListeners {
@@ -2034,12 +1914,13 @@ func (b *LocalBackend) initPeerAPIListener() {
 		if !skipListen {
 			ln, err = ps.listen(a.IP(), b.prevIfState)
 			if err != nil {
-				if peerAPIListenAsync {
-					// Expected. But we fix it later in linkChange
+				if runtime.GOOS == "windows" {
+					// Expected for now. See Issue 1620.
+					// But we fix it later in linkChange
 					// ("peerAPIListeners too low").
 					continue
 				}
-				b.logf("[unexpected] peerapi listen(%q) error: %v", a.IP(), err)
+				b.logf("[unexpected] peerapi listen(%q) error: %v", a.IP, err)
 				continue
 			}
 		}
@@ -2138,11 +2019,6 @@ func (b *LocalBackend) routerConfig(cfg *wgcfg.Config, prefs *ipn.Prefs) *router
 		Routes:           peerRoutes(cfg.Peers, 10_000),
 	}
 
-	if distro.Get() == distro.Synology {
-		// Issue 1995: we don't use iptables on Synology.
-		rs.NetfilterMode = preftype.NetfilterOff
-	}
-
 	// Sanity check: we expect the control server to program both a v4
 	// and a v6 default route, if default routing is on. Fill in
 	// blackhole routes appropriately if we're missing some. This is
@@ -2168,21 +2044,18 @@ func (b *LocalBackend) routerConfig(cfg *wgcfg.Config, prefs *ipn.Prefs) *router
 		if !default6 {
 			rs.Routes = append(rs.Routes, ipv6Default)
 		}
-		internalIPs, externalIPs, err := internalAndExternalInterfaces()
-		if err != nil {
-			b.logf("failed to discover interface ips: %v", err)
-		}
-		if runtime.GOOS == "linux" || runtime.GOOS == "darwin" || runtime.GOOS == "windows" {
-			rs.LocalRoutes = internalIPs // unconditionally allow access to guest VM networks
+		if runtime.GOOS == "linux" {
+			// Only allow local lan access on linux machines for now.
+			ips, _, err := interfaceRoutes()
+			if err != nil {
+				b.logf("failed to discover interface ips: %v", err)
+			}
 			if prefs.ExitNodeAllowLANAccess {
-				rs.LocalRoutes = append(rs.LocalRoutes, externalIPs...)
-				if len(externalIPs) != 0 {
-					b.logf("allowing exit node access to internal IPs: %v", internalIPs)
-				}
+				rs.LocalRoutes = ips.Prefixes()
 			} else {
 				// Explicitly add routes to the local network so that we do not
 				// leak any traffic.
-				rs.Routes = append(rs.Routes, externalIPs...)
+				rs.Routes = append(rs.Routes, ips.Prefixes()...)
 			}
 		}
 	}
@@ -2211,24 +2084,10 @@ func applyPrefsToHostinfo(hi *tailcfg.Hostinfo, prefs *ipn.Prefs) {
 	}
 	if v := prefs.OSVersion; v != "" {
 		hi.OSVersion = v
-
-		// The Android app annotates when Google Play Services
-		// aren't available by tacking on a string to the
-		// OSVersion. Promote that to the Hostinfo.Package
-		// field instead, rather than adding a new pref, as
-		// this applyPrefsToHostinfo mechanism is mostly
-		// abused currently. TODO(bradfitz): instead let
-		// frontends update Hostinfo, without using Prefs.
-		if runtime.GOOS == "android" && strings.HasSuffix(v, " [nogoogle]") {
-			hi.Package = "nogoogle"
-			hi.OSVersion = strings.TrimSuffix(v, " [nogoogle]")
-		}
 	}
 	if m := prefs.DeviceModel; m != "" {
 		hi.DeviceModel = m
 	}
-	hi.RoutableIPs = append(prefs.AdvertiseRoutes[:0:0], prefs.AdvertiseRoutes...)
-	hi.RequestTags = append(prefs.AdvertiseTags[:0:0], prefs.AdvertiseTags...)
 	hi.ShieldsUp = prefs.ShieldsUp
 }
 
@@ -2244,7 +2103,9 @@ func (b *LocalBackend) enterState(newState ipn.State) {
 	oldState := b.state
 	b.state = newState
 	prefs := b.prefs
+	cc := b.cc
 	netMap := b.netMap
+	networkUp := b.prevIfState.AnyInterfaceUp()
 	activeLogin := b.activeLogin
 	authURL := b.authURL
 	if newState == ipn.Running {
@@ -2254,7 +2115,6 @@ func (b *LocalBackend) enterState(newState ipn.State) {
 		// Transitioning away from running.
 		b.closePeerAPIListenersLocked()
 	}
-	b.maybePauseControlClientLocked()
 	b.mu.Unlock()
 
 	if oldState == newState {
@@ -2265,13 +2125,17 @@ func (b *LocalBackend) enterState(newState ipn.State) {
 	health.SetIPNState(newState.String(), prefs.WantRunning)
 	b.send(ipn.Notify{State: &newState})
 
+	if cc != nil {
+		cc.SetPaused((newState == ipn.Stopped && netMap != nil) || !networkUp)
+	}
+
 	switch newState {
 	case ipn.NeedsLogin:
 		systemd.Status("Needs login: %s", authURL)
 		b.blockEngineUpdates(true)
 		fallthrough
 	case ipn.Stopped:
-		err := b.e.Reconfig(&wgcfg.Config{}, &router.Config{}, &dns.Config{}, nil)
+		err := b.e.Reconfig(&wgcfg.Config{}, &router.Config{}, &dns.Config{})
 		if err != nil {
 			b.logf("Reconfig(down): %v", err)
 		}
@@ -2285,7 +2149,7 @@ func (b *LocalBackend) enterState(newState ipn.State) {
 		b.e.RequestStatus()
 	case ipn.Running:
 		var addrs []string
-		for _, addr := range netMap.Addresses {
+		for _, addr := range b.netMap.Addresses {
 			addrs = append(addrs, addr.IP().String())
 		}
 		systemd.Status("Connected; %s; %s", activeLogin, strings.Join(addrs, " "))
@@ -2391,7 +2255,7 @@ func (b *LocalBackend) stateMachine() {
 // a status update that predates the "I've shut down" update.
 func (b *LocalBackend) stopEngineAndWait() {
 	b.logf("stopEngineAndWait...")
-	b.e.Reconfig(&wgcfg.Config{}, &router.Config{}, &dns.Config{}, nil)
+	b.e.Reconfig(&wgcfg.Config{}, &router.Config{}, &dns.Config{})
 	b.requestEngineStatusAndWait()
 	b.logf("stopEngineAndWait: done.")
 }
@@ -2448,6 +2312,7 @@ func (b *LocalBackend) LogoutSync(ctx context.Context) error {
 func (b *LocalBackend) logout(ctx context.Context, sync bool) error {
 	b.mu.Lock()
 	cc := b.cc
+	b.setNetMapLocked(nil)
 	b.mu.Unlock()
 
 	b.EditPrefs(&ipn.MaskedPrefs{
@@ -2474,6 +2339,10 @@ func (b *LocalBackend) logout(ctx context.Context, sync bool) error {
 		cc.StartLogout()
 	}
 
+	b.mu.Lock()
+	b.setNetMapLocked(nil)
+	b.mu.Unlock()
+
 	b.stateMachine()
 	return err
 }
@@ -2525,7 +2394,6 @@ func (b *LocalBackend) setNetMapLocked(nm *netmap.NetworkMap) {
 		b.logf("active login: %v", login)
 		b.activeLogin = login
 	}
-	b.maybePauseControlClientLocked()
 
 	// Determine if file sharing is enabled
 	fs := hasCapability(nm, tailcfg.CapabilityFileSharing)
@@ -2676,42 +2544,6 @@ func (b *LocalBackend) FileTargets() ([]*apitype.FileTarget, error) {
 	return ret, nil
 }
 
-// SetDNS adds a DNS record for the given domain name & TXT record
-// value.
-//
-// It's meant for use with dns-01 ACME (LetsEncrypt) challenges.
-//
-// This is the low-level interface. Other layers will provide more
-// friendly options to get HTTPS certs.
-func (b *LocalBackend) SetDNS(ctx context.Context, name, value string) error {
-	req := &tailcfg.SetDNSRequest{
-		Version: 1,
-		Type:    "TXT",
-		Name:    name,
-		Value:   value,
-	}
-
-	b.mu.Lock()
-	cc := b.cc
-	if prefs := b.prefs; prefs != nil {
-		req.NodeKey = tailcfg.NodeKey(prefs.Persist.PrivateNodeKey.Public())
-	}
-	b.mu.Unlock()
-	if cc == nil {
-		return errors.New("not connected")
-	}
-	if req.NodeKey.IsZero() {
-		return errors.New("no nodekey")
-	}
-	if name == "" {
-		return errors.New("missing 'name'")
-	}
-	if value == "" {
-		return errors.New("missing 'value'")
-	}
-	return cc.SetDNS(ctx, req)
-}
-
 func (b *LocalBackend) registerIncomingFile(inf *incomingFile, active bool) {
 	b.mu.Lock()
 	defer b.mu.Unlock()
@@ -2784,6 +2616,7 @@ func (b *LocalBackend) CheckIPForwarding() error {
 		return nil
 	}
 	if isBSD(runtime.GOOS) {
+		//lint:ignore ST1005 output to users as is
 		return fmt.Errorf("Subnet routing and exit nodes only work with additional manual configuration on %v, and is not currently officially supported.", runtime.GOOS)
 	}
 
@@ -2797,18 +2630,20 @@ func (b *LocalBackend) CheckIPForwarding() error {
 		return nil
 	}
 
-	const suffix = "\nSubnet routes won't work without IP forwarding.\nSee https://tailscale.com/kb/1104/enable-ip-forwarding/"
 	for _, key := range keys {
 		bs, err := exec.Command("sysctl", "-n", key).Output()
 		if err != nil {
-			return fmt.Errorf("couldn't check %s (%v)%s", key, err, suffix)
+			//lint:ignore ST1005 output to users as is
+			return fmt.Errorf("couldn't check %s (%v).\nSubnet routes won't work without IP forwarding.", key, err)
 		}
 		on, err := strconv.ParseBool(string(bytes.TrimSpace(bs)))
 		if err != nil {
-			return fmt.Errorf("couldn't parse %s (%v)%s.", key, err, suffix)
+			//lint:ignore ST1005 output to users as is
+			return fmt.Errorf("couldn't parse %s (%v).\nSubnet routes won't work without IP forwarding.", key, err)
 		}
 		if !on {
-			return fmt.Errorf("%s is disabled.%s", key, suffix)
+			//lint:ignore ST1005 output to users as is
+			return fmt.Errorf("%s is disabled. Subnet routes won't work.", key)
 		}
 	}
 	return nil
@@ -2826,13 +2661,3 @@ func (b *LocalBackend) PeerDialControlFunc() func(network, address string, c sys
 	}
 	return nil
 }
-
-// DERPMap returns the current DERPMap in use, or nil if not connected.
-func (b *LocalBackend) DERPMap() *tailcfg.DERPMap {
-	b.mu.Lock()
-	defer b.mu.Unlock()
-	if b.netMap == nil {
-		return nil
-	}
-	return b.netMap.DERPMap
-}

ipn/ipnlocal/peerapi_macios_ext.go

@@ -2,21 +2,21 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build ts_macext && (darwin || ios)
-// +build ts_macext
-// +build darwin ios
+// +build darwin,redo ios,redo
 
 package ipnlocal
 
 import (
 	"errors"
 	"fmt"
+	"log"
 	"net"
+	"strings"
 	"syscall"
 
+	"golang.org/x/sys/unix"
 	"inet.af/netaddr"
 	"tailscale.com/net/interfaces"
-	"tailscale.com/net/netns"
 )
 
 func init() {
@@ -32,7 +32,29 @@ func initListenConfigNetworkExtension(nc *net.ListenConfig, ip netaddr.IP, st *i
 	if !ok {
 		return fmt.Errorf("no interface with name %q", tunIfName)
 	}
-	return netns.SetListenConfigInterfaceIndex(nc, tunIf.Index)
+	nc.Control = func(network, address string, c syscall.RawConn) error {
+		var sockErr error
+		err := c.Control(func(fd uintptr) {
+			sockErr = bindIf(fd, network, address, 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
+}
+
+func bindIf(fd uintptr, network, address string, ifIndex int) error {
+	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
+	}
+	return unix.SetsockoptInt(int(fd), proto, opt, ifIndex)
 }
 
 func peerDialControlFuncNetworkExtension(b *LocalBackend) func(network, address string, c syscall.RawConn) error {
@@ -46,12 +68,17 @@ func peerDialControlFuncNetworkExtension(b *LocalBackend) func(network, address
 			index = tunIf.Index
 		}
 	}
-	var lc net.ListenConfig
-	netns.SetListenConfigInterfaceIndex(&lc, index)
 	return func(network, address string, c syscall.RawConn) error {
 		if index == -1 {
 			return errors.New("failed to find TUN interface to bind to")
 		}
-		return lc.Control(network, address, c)
+		var sockErr error
+		err := c.Control(func(fd uintptr) {
+			sockErr = bindIf(fd, network, address, index)
+		})
+		if err != nil {
+			return err
+		}
+		return sockErr
 	}
 }

ipn/ipnlocal/state_test.go

@@ -14,7 +14,6 @@ import (
 
 	"tailscale.com/control/controlclient"
 	"tailscale.com/ipn"
-	"tailscale.com/syncs"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/empty"
 	"tailscale.com/types/logger"
@@ -141,8 +140,6 @@ func (cc *mockControl) send(err error, url string, loginFinished bool, nm *netma
 		}
 		if loginFinished {
 			s.LoginFinished = &empty.Message{}
-		} else if url == "" && err == nil && nm == nil {
-			s.LogoutFinished = &empty.Message{}
 		}
 		cc.statusFunc(s)
 	}
@@ -249,10 +246,6 @@ func (cc *mockControl) UpdateEndpoints(localPort uint16, endpoints []tailcfg.End
 	cc.called("UpdateEndpoints")
 }
 
-func (*mockControl) SetDNS(context.Context, *tailcfg.SetDNSRequest) error {
-	panic("unexpected SetDNS call")
-}
-
 // A very precise test of the sequence of function calls generated by
 // ipnlocal.Local into its controlclient instance, and the events it
 // produces upstream into the UI.
@@ -278,7 +271,7 @@ func TestStateMachine(t *testing.T) {
 	c := qt.New(t)
 
 	logf := t.Logf
-	store := new(testStateStorage)
+	store := new(ipn.MemoryStore)
 	e, err := wgengine.NewFakeUserspaceEngine(logf, 0)
 	if err != nil {
 		t.Fatalf("NewFakeUserspaceEngine: %v", err)
@@ -354,7 +347,7 @@ func TestStateMachine(t *testing.T) {
 	c.Assert(b.Start(ipn.Options{StateKey: ipn.GlobalDaemonStateKey}), qt.IsNil)
 	{
 		// BUG: strictly, it should pause, not unpause, here, since !WantRunning.
-		c.Assert([]string{"Shutdown", "unpause", "New", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"Shutdown", "New", "unpause"}, qt.DeepEquals, cc.getCalls())
 
 		nn := notifies.drain(2)
 		c.Assert(cc.getCalls(), qt.HasLen, 0)
@@ -389,7 +382,7 @@ func TestStateMachine(t *testing.T) {
 	url1 := "http://localhost:1/1"
 	cc.send(nil, url1, false, nil)
 	{
-		c.Assert(cc.getCalls(), qt.DeepEquals, []string{"unpause"})
+		c.Assert(cc.getCalls(), qt.DeepEquals, []string{})
 
 		// ...but backend eats that notification, because the user
 		// didn't explicitly request interactive login yet, and
@@ -414,7 +407,7 @@ func TestStateMachine(t *testing.T) {
 		// We're still not logged in so there's nothing we can do
 		// with it. (And empirically, it's providing an empty list
 		// of endpoints.)
-		c.Assert([]string{"UpdateEndpoints", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"UpdateEndpoints"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].BrowseToURL, qt.Not(qt.IsNil))
 		c.Assert(url1, qt.Equals, *nn[0].BrowseToURL)
 	}
@@ -440,7 +433,7 @@ func TestStateMachine(t *testing.T) {
 	cc.send(nil, url2, false, nil)
 	{
 		// BUG: UpdateEndpoints again, this is getting silly.
-		c.Assert([]string{"UpdateEndpoints", "unpause", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"UpdateEndpoints"}, qt.DeepEquals, cc.getCalls())
 
 		// This time, backend should emit it to the UI right away,
 		// because the UI is anxiously awaiting a new URL to visit.
@@ -470,7 +463,7 @@ func TestStateMachine(t *testing.T) {
 		// wait until it gets into Starting.
 		// TODO: (Currently this test doesn't detect that bug, but
 		// it's visible in the logs)
-		c.Assert([]string{"unpause", "unpause", "UpdateEndpoints", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"unpause", "UpdateEndpoints"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].LoginFinished, qt.Not(qt.IsNil))
 		c.Assert(nn[1].Prefs, qt.Not(qt.IsNil))
 		c.Assert(nn[2].State, qt.Not(qt.IsNil))
@@ -483,7 +476,7 @@ func TestStateMachine(t *testing.T) {
 	notifies.expect(1)
 	// BUG: the real controlclient sends LoginFinished with every
 	// notification while it's in StateAuthenticated, but not StateSynced.
-	// It should send it exactly once, or every time we're authenticated,
+	// We should send it exactly once, or every time we're authenticated,
 	// but the current code is brittle.
 	// (ie. I suspect it would be better to change false->true in send()
 	// below, and do the same in the real controlclient.)
@@ -492,7 +485,7 @@ func TestStateMachine(t *testing.T) {
 	})
 	{
 		nn := notifies.drain(1)
-		c.Assert([]string{"unpause", "unpause", "UpdateEndpoints", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"unpause", "UpdateEndpoints"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].State, qt.Not(qt.IsNil))
 		c.Assert(ipn.Starting, qt.Equals, *nn[0].State)
 	}
@@ -524,7 +517,6 @@ func TestStateMachine(t *testing.T) {
 
 	// The user changes their preference to WantRunning after all.
 	t.Logf("\n\nWantRunning -> true")
-	store.awaitWrite()
 	notifies.expect(2)
 	b.EditPrefs(&ipn.MaskedPrefs{
 		WantRunningSet: true,
@@ -534,17 +526,15 @@ func TestStateMachine(t *testing.T) {
 		nn := notifies.drain(2)
 		// BUG: UpdateEndpoints isn't needed here.
 		// BUG: Login isn't needed here. We never logged out.
-		c.Assert([]string{"Login", "unpause", "UpdateEndpoints", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"Login", "unpause", "UpdateEndpoints"}, qt.DeepEquals, cc.getCalls())
 		// BUG: I would expect Prefs to change first, and state after.
 		c.Assert(nn[0].State, qt.Not(qt.IsNil))
 		c.Assert(nn[1].Prefs, qt.Not(qt.IsNil))
 		c.Assert(ipn.Starting, qt.Equals, *nn[0].State)
-		c.Assert(store.sawWrite(), qt.IsTrue)
 	}
 
 	// Test the fast-path frontend reconnection.
-	// This one is very finicky, so we have to force State==Running
-	// or it won't use the fast path.
+	// This one is very finicky, so we have to force State==Running.
 	// TODO: actually get to State==Running, rather than cheating.
 	//  That'll require spinning up a fake DERP server and putting it in
 	//  the netmap.
@@ -558,39 +548,39 @@ func TestStateMachine(t *testing.T) {
 		c.Assert(nn[0].State, qt.Not(qt.IsNil))
 		c.Assert(nn[0].LoginFinished, qt.Not(qt.IsNil))
 		c.Assert(nn[0].NetMap, qt.Not(qt.IsNil))
-		c.Assert(nn[0].Prefs, qt.Not(qt.IsNil))
+		// BUG: Prefs should be sent too, or the UI could end up in
+		// a bad state. (iOS, the only current user of this feature,
+		// probably wouldn't notice because it happens to not display
+		// any prefs. Maybe exit nodes will look weird?)
 	}
 
 	// undo the state hack above.
 	b.state = ipn.Starting
 
 	// User wants to logout.
-	store.awaitWrite()
 	t.Logf("\n\nLogout (async)")
 	notifies.expect(2)
 	b.Logout()
 	{
 		nn := notifies.drain(2)
-		c.Assert([]string{"pause", "StartLogout", "pause"}, qt.DeepEquals, cc.getCalls())
+		// BUG: now is not the time to unpause.
+		c.Assert([]string{"unpause", "StartLogout"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].State, qt.Not(qt.IsNil))
 		c.Assert(nn[1].Prefs, qt.Not(qt.IsNil))
-		c.Assert(ipn.Stopped, qt.Equals, *nn[0].State)
+		c.Assert(ipn.NeedsLogin, qt.Equals, *nn[0].State)
 		c.Assert(nn[1].Prefs.LoggedOut, qt.IsTrue)
 		c.Assert(nn[1].Prefs.WantRunning, qt.IsFalse)
-		c.Assert(ipn.Stopped, qt.Equals, b.State())
-		c.Assert(store.sawWrite(), qt.IsTrue)
+		c.Assert(ipn.NeedsLogin, qt.Equals, b.State())
 	}
 
 	// Let's make the logout succeed.
 	t.Logf("\n\nLogout (async) - succeed")
-	notifies.expect(1)
+	notifies.expect(0)
 	cc.setAuthBlocked(true)
 	cc.send(nil, "", false, nil)
 	{
-		nn := notifies.drain(1)
-		c.Assert([]string{"unpause", "unpause"}, qt.DeepEquals, cc.getCalls())
-		c.Assert(nn[0].State, qt.Not(qt.IsNil))
-		c.Assert(ipn.NeedsLogin, qt.Equals, *nn[0].State)
+		notifies.drain(0)
+		c.Assert(cc.getCalls(), qt.HasLen, 0)
 		c.Assert(b.Prefs().LoggedOut, qt.IsTrue)
 		c.Assert(b.Prefs().WantRunning, qt.IsFalse)
 		c.Assert(ipn.NeedsLogin, qt.Equals, b.State())
@@ -604,7 +594,7 @@ func TestStateMachine(t *testing.T) {
 		notifies.drain(0)
 		// BUG: the backend has already called StartLogout, and we're
 		// still logged out. So it shouldn't call it again.
-		c.Assert([]string{"StartLogout", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"StartLogout"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(cc.getCalls(), qt.HasLen, 0)
 		c.Assert(b.Prefs().LoggedOut, qt.IsTrue)
 		c.Assert(b.Prefs().WantRunning, qt.IsFalse)
@@ -618,7 +608,8 @@ func TestStateMachine(t *testing.T) {
 	cc.send(nil, "", false, nil)
 	{
 		notifies.drain(0)
-		c.Assert(cc.getCalls(), qt.DeepEquals, []string{"unpause", "unpause"})
+		c.Assert(cc.getCalls(), qt.HasLen, 0)
+		c.Assert(cc.getCalls(), qt.HasLen, 0)
 		c.Assert(b.Prefs().LoggedOut, qt.IsTrue)
 		c.Assert(b.Prefs().WantRunning, qt.IsFalse)
 		c.Assert(ipn.NeedsLogin, qt.Equals, b.State())
@@ -632,7 +623,7 @@ func TestStateMachine(t *testing.T) {
 	// I guess, since that's supposed to be synchronous.
 	{
 		notifies.drain(0)
-		c.Assert([]string{"Logout", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"Logout"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(cc.getCalls(), qt.HasLen, 0)
 		c.Assert(b.Prefs().LoggedOut, qt.IsTrue)
 		c.Assert(b.Prefs().WantRunning, qt.IsFalse)
@@ -646,7 +637,8 @@ func TestStateMachine(t *testing.T) {
 	cc.send(nil, "", false, nil)
 	{
 		notifies.drain(0)
-		c.Assert(cc.getCalls(), qt.DeepEquals, []string{"unpause", "unpause"})
+		c.Assert(cc.getCalls(), qt.HasLen, 0)
+		c.Assert(cc.getCalls(), qt.HasLen, 0)
 		c.Assert(b.Prefs().LoggedOut, qt.IsTrue)
 		c.Assert(b.Prefs().WantRunning, qt.IsFalse)
 		c.Assert(ipn.NeedsLogin, qt.Equals, b.State())
@@ -677,7 +669,7 @@ func TestStateMachine(t *testing.T) {
 		// BUG: We already called Shutdown(), no need to do it again.
 		// BUG: Way too soon for UpdateEndpoints.
 		// BUG: don't unpause because we're not logged in.
-		c.Assert([]string{"Shutdown", "unpause", "New", "UpdateEndpoints", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"Shutdown", "New", "UpdateEndpoints", "unpause"}, qt.DeepEquals, cc.getCalls())
 
 		nn := notifies.drain(2)
 		c.Assert(cc.getCalls(), qt.HasLen, 0)
@@ -702,7 +694,7 @@ func TestStateMachine(t *testing.T) {
 	})
 	{
 		nn := notifies.drain(3)
-		c.Assert([]string{"unpause", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"unpause"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].LoginFinished, qt.Not(qt.IsNil))
 		c.Assert(nn[1].Prefs, qt.Not(qt.IsNil))
 		c.Assert(nn[2].State, qt.Not(qt.IsNil))
@@ -742,8 +734,9 @@ func TestStateMachine(t *testing.T) {
 		//  on startup, otherwise UIs can't show the node list, login
 		//  name, etc when in state ipn.Stopped.
 		//  Arguably they shouldn't try. But they currently do.
+		c.Assert([]string{"Shutdown", "New", "UpdateEndpoints", "Login", "unpause"}, qt.DeepEquals, cc.getCalls())
+
 		nn := notifies.drain(2)
-		c.Assert([]string{"Shutdown", "unpause", "New", "UpdateEndpoints", "Login", "unpause"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(cc.getCalls(), qt.HasLen, 0)
 		c.Assert(nn[0].Prefs, qt.Not(qt.IsNil))
 		c.Assert(nn[1].State, qt.Not(qt.IsNil))
@@ -752,25 +745,6 @@ func TestStateMachine(t *testing.T) {
 		c.Assert(ipn.Stopped, qt.Equals, *nn[1].State)
 	}
 
-	// When logged in but !WantRunning, ipn leaves us unpaused to retrieve
-	// the first netmap. Simulate that netmap being received, after which
-	// it should pause us, to avoid wasting CPU retrieving unnecessarily
-	// additional netmap updates.
-	//
-	// TODO: really the various GUIs and prefs should be refactored to
-	//  not require the netmap structure at all when starting while
-	//  !WantRunning. That would remove the need for this (or contacting
-	//  the control server at all when stopped).
-	t.Logf("\n\nStart4 -> netmap")
-	notifies.expect(0)
-	cc.send(nil, "", true, &netmap.NetworkMap{
-		MachineStatus: tailcfg.MachineAuthorized,
-	})
-	{
-		notifies.drain(0)
-		c.Assert([]string{"pause", "pause"}, qt.DeepEquals, cc.getCalls())
-	}
-
 	// Request connection.
 	// The state machine didn't call Login() earlier, so now it needs to.
 	t.Logf("\n\nWantRunning4 -> true")
@@ -797,7 +771,7 @@ func TestStateMachine(t *testing.T) {
 	})
 	{
 		nn := notifies.drain(2)
-		c.Assert([]string{"pause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"unpause"}, qt.DeepEquals, cc.getCalls())
 		// BUG: I would expect Prefs to change first, and state after.
 		c.Assert(nn[0].State, qt.Not(qt.IsNil))
 		c.Assert(nn[1].Prefs, qt.Not(qt.IsNil))
@@ -807,27 +781,25 @@ func TestStateMachine(t *testing.T) {
 	// We want to try logging in as a different user, while Stopped.
 	// First, start the login process (without logging out first).
 	t.Logf("\n\nLoginDifferent")
-	notifies.expect(1)
+	notifies.expect(2)
 	b.StartLoginInteractive()
 	url3 := "http://localhost:1/3"
 	cc.send(nil, url3, false, nil)
 	{
-		nn := notifies.drain(1)
+		nn := notifies.drain(2)
 		// It might seem like WantRunning should switch to true here,
 		// but that would be risky since we already have a valid
 		// user account. It might try to reconnect to the old account
 		// before the new one is ready. So no change yet.
-		//
-		// Because the login hasn't yet completed, the old login
-		// is still valid, so it's correct that we stay paused.
-		c.Assert([]string{"Login", "pause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"Login", "unpause"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].BrowseToURL, qt.Not(qt.IsNil))
+		c.Assert(nn[1].State, qt.Not(qt.IsNil))
 		c.Assert(*nn[0].BrowseToURL, qt.Equals, url3)
+		c.Assert(ipn.NeedsLogin, qt.Equals, *nn[1].State)
 	}
 
-	// Now, let's complete the interactive login, using a different
-	// user account than before. WantRunning changes to true after an
-	// interactive login, so we end up unpaused.
+	// Now, let's say the interactive login completed, using a different
+	// user account than before.
 	t.Logf("\n\nLoginDifferent URL visited")
 	notifies.expect(3)
 	cc.persist.LoginName = "user3"
@@ -836,13 +808,7 @@ func TestStateMachine(t *testing.T) {
 	})
 	{
 		nn := notifies.drain(3)
-		// BUG: pause() being called here is a bad sign.
-		//  It means that either the state machine ran at least once
-		//  with the old netmap, or it ran with the new login+netmap
-		//  and !WantRunning. But since it's a fresh and successful
-		//  new login, WantRunning is true, so there was never a
-		//  reason to pause().
-		c.Assert([]string{"pause", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"unpause"}, qt.DeepEquals, cc.getCalls())
 		c.Assert(nn[0].LoginFinished, qt.Not(qt.IsNil))
 		c.Assert(nn[1].Prefs, qt.Not(qt.IsNil))
 		c.Assert(nn[2].State, qt.Not(qt.IsNil))
@@ -861,7 +827,7 @@ func TestStateMachine(t *testing.T) {
 	{
 		// NOTE: cc.Shutdown() is correct here, since we didn't call
 		// b.Shutdown() ourselves.
-		c.Assert([]string{"Shutdown", "unpause", "New", "UpdateEndpoints", "Login", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"Shutdown", "New", "UpdateEndpoints", "Login"}, qt.DeepEquals, cc.getCalls())
 
 		nn := notifies.drain(1)
 		c.Assert(cc.getCalls(), qt.HasLen, 0)
@@ -880,7 +846,7 @@ func TestStateMachine(t *testing.T) {
 	})
 	{
 		nn := notifies.drain(1)
-		c.Assert([]string{"unpause", "unpause"}, qt.DeepEquals, cc.getCalls())
+		c.Assert([]string{"unpause"}, qt.DeepEquals, cc.getCalls())
 		// NOTE: No LoginFinished message since no interactive
 		// login was needed.
 		c.Assert(nn[0].State, qt.Not(qt.IsNil))
@@ -891,29 +857,3 @@ func TestStateMachine(t *testing.T) {
 		c.Assert(ipn.Starting, qt.Equals, b.State())
 	}
 }
-
-type testStateStorage struct {
-	mem     ipn.MemoryStore
-	written syncs.AtomicBool
-}
-
-func (s *testStateStorage) ReadState(id ipn.StateKey) ([]byte, error) {
-	return s.mem.ReadState(id)
-}
-
-func (s *testStateStorage) WriteState(id ipn.StateKey, bs []byte) error {
-	s.written.Set(true)
-	return s.mem.WriteState(id, bs)
-}
-
-// awaitWrite clears the "I've seen writes" bit, in prep for a future
-// call to sawWrite to see if a write arrived.
-func (s *testStateStorage) awaitWrite() { s.written.Set(false) }
-
-// sawWrite reports whether there's been a WriteState call since the most
-// recent awaitWrite call.
-func (s *testStateStorage) sawWrite() bool {
-	v := s.written.Get()
-	s.awaitWrite()
-	return v
-}

ipn/ipnserver/server.go

@@ -24,6 +24,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -40,11 +41,9 @@ import (
 	"tailscale.com/safesocket"
 	"tailscale.com/smallzstd"
 	"tailscale.com/types/logger"
-	"tailscale.com/util/groupmember"
 	"tailscale.com/util/pidowner"
 	"tailscale.com/util/systemd"
 	"tailscale.com/version"
-	"tailscale.com/version/distro"
 	"tailscale.com/wgengine"
 )
 
@@ -348,32 +347,51 @@ func isReadonlyConn(ci connIdentity, operatorUID string, logf logger.Logf) bool
 		logf("connection from userid %v; is configured operator", uid)
 		return rw
 	}
-	if yes, err := isLocalAdmin(uid); err != nil {
-		logf("connection from userid %v; read-only; %v", uid, err)
+	var adminGroupID string
+	switch runtime.GOOS {
+	case "darwin":
+		adminGroupID = darwinAdminGroupID()
+	default:
+		logf("connection from userid %v; read-only", uid)
 		return ro
-	} else if yes {
-		logf("connection from userid %v; is local admin, has access", uid)
-		return rw
+	}
+	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
 }
 
-func isLocalAdmin(uid string) (bool, error) {
-	u, err := user.LookupId(uid)
+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 false, err
+		return ""
 	}
-	var adminGroup string
-	switch {
-	case runtime.GOOS == "darwin":
-		adminGroup = "admin"
-	case distro.Get() == distro.QNAP:
-		adminGroup = "administrators"
-	default:
-		return false, fmt.Errorf("no system admin group found")
-	}
-	return groupmember.IsMemberOfGroup(adminGroup, u.Username)
+	darwinAdminGroupIDCache.Store(g.Gid)
+	return g.Gid
 }
 
 // inUseOtherUserError is the error type for when the server is in use
@@ -397,10 +415,12 @@ func (s *server) checkConnIdentityLocked(ci connIdentity) error {
 			break
 		}
 		if ci.UserID != active.UserID {
+			//lint:ignore ST1005 we want to capitalize Tailscale here
 			return inUseOtherUserError{fmt.Errorf("Tailscale already in use by %s, pid %d", active.User.Username, active.Pid)}
 		}
 	}
 	if su := s.serverModeUser; su != nil && ci.UserID != su.Uid {
+		//lint:ignore ST1005 we want to capitalize Tailscale here
 		return inUseOtherUserError{fmt.Errorf("Tailscale already in use by %s", su.Username)}
 	}
 	return nil

ipn/ipnstate/ipnstate.go

@@ -45,13 +45,6 @@ type Status struct {
 	// has MagicDNS enabled.
 	MagicDNSSuffix string
 
-	// CertDomains are the set of DNS names for which the control
-	// plane server will assist with provisioning TLS
-	// certificates. See SetDNSRequest for dns-01 ACME challenges
-	// for e.g. LetsEncrypt. These names are FQDNs without
-	// trailing periods, and without any "_acme-challenge." prefix.
-	CertDomains []string
-
 	Peer map[key.Public]*PeerStatus
 	User map[tailcfg.UserID]tailcfg.UserProfile
 }
@@ -96,13 +89,6 @@ type PeerStatus struct {
 	KeepAlive     bool
 	ExitNode      bool // true if this is the currently selected exit node.
 
-	// Active is whether the node was recently active. The
-	// definition is somewhat undefined but has historically and
-	// currently means that there was some packet sent to this
-	// peer in the past two minutes. That definition is subject to
-	// change.
-	Active bool
-
 	PeerAPIURL   []string
 	Capabilities []string `json:",omitempty"`
 
@@ -284,9 +270,6 @@ func (sb *StatusBuilder) AddPeer(peer key.Public, st *PeerStatus) {
 	if st.ShareeNode {
 		e.ShareeNode = true
 	}
-	if st.Active {
-		e.Active = true
-	}
 }
 
 type StatusUpdater interface {
@@ -387,7 +370,9 @@ table tbody tr:nth-child(even) td { background-color: #f5f5f5; }
 		)
 		f("<td>")
 
-		if ps.Active {
+		// TODO: let server report this active bool instead
+		active := !ps.LastWrite.IsZero() && time.Since(ps.LastWrite) < 2*time.Minute
+		if active {
 			if ps.Relay != "" && ps.CurAddr == "" {
 				f("relay <b>%s</b>", html.EscapeString(ps.Relay))
 			} else if ps.CurAddr != "" {

ipn/localapi/cert.go

@@ -1,450 +0,0 @@
-// 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.
-
-//go:build !ios && !android
-// +build !ios,!android
-
-package localapi
-
-import (
-	"bytes"
-	"context"
-	"crypto"
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rand"
-	"crypto/rsa"
-	"crypto/tls"
-	"crypto/x509"
-	"crypto/x509/pkix"
-	"encoding/json"
-	"encoding/pem"
-	"errors"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"log"
-	"net"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"golang.org/x/crypto/acme"
-	"tailscale.com/ipn/ipnstate"
-	"tailscale.com/paths"
-	"tailscale.com/types/logger"
-)
-
-// Process-wide cache. (A new *Handler is created per connection,
-// effectively per request)
-var (
-	// acmeMu guards all ACME operations, so concurrent requests
-	// for certs don't slam ACME. The first will go through and
-	// populate the on-disk cache and the rest should use that.
-	acmeMu sync.Mutex
-
-	renewMu        sync.Mutex // lock order: don't hold acmeMu and renewMu at the same time
-	lastRenewCheck = map[string]time.Time{}
-)
-
-func (h *Handler) certDir() (string, error) {
-	base := paths.DefaultTailscaledStateFile()
-	if base == "" {
-		return "", errors.New("no default DefaultTailscaledStateFile")
-	}
-	full := filepath.Join(filepath.Dir(base), "certs")
-	if err := os.MkdirAll(full, 0700); err != nil {
-		return "", err
-	}
-	return full, nil
-}
-
-var acmeDebug, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_ACME"))
-
-func (h *Handler) serveCert(w http.ResponseWriter, r *http.Request) {
-	if !h.PermitWrite {
-		http.Error(w, "cert access denied", http.StatusForbidden)
-		return
-	}
-	dir, err := h.certDir()
-	if err != nil {
-		h.logf("certDir: %v", err)
-		http.Error(w, "failed to get cert dir", 500)
-		return
-	}
-
-	domain := strings.TrimPrefix(r.URL.Path, "/localapi/v0/cert/")
-	if domain == r.URL.Path {
-		http.Error(w, "internal handler config wired wrong", 500)
-		return
-	}
-
-	now := time.Now()
-	logf := logger.WithPrefix(h.logf, fmt.Sprintf("cert(%q): ", domain))
-	traceACME := func(v interface{}) {
-		if !acmeDebug {
-			return
-		}
-		j, _ := json.MarshalIndent(v, "", "\t")
-		log.Printf("acme %T: %s", v, j)
-	}
-
-	if pair, ok := h.getCertPEMCached(dir, domain, now); ok {
-		future := now.AddDate(0, 0, 14)
-		if h.shouldStartDomainRenewal(dir, domain, future) {
-			logf("starting async renewal")
-			// Start renewal in the background.
-			go h.getCertPEM(context.Background(), logf, traceACME, dir, domain, future)
-		}
-		serveKeyPair(w, r, pair)
-		return
-	}
-
-	pair, err := h.getCertPEM(r.Context(), logf, traceACME, dir, domain, now)
-	if err != nil {
-		logf("getCertPEM: %v", err)
-		http.Error(w, fmt.Sprint(err), 500)
-		return
-	}
-	serveKeyPair(w, r, pair)
-}
-
-func (h *Handler) shouldStartDomainRenewal(dir, domain string, future time.Time) bool {
-	renewMu.Lock()
-	defer renewMu.Unlock()
-	now := time.Now()
-	if last, ok := lastRenewCheck[domain]; ok && now.Sub(last) < time.Minute {
-		// We checked very recently. Don't bother reparsing &
-		// validating the x509 cert.
-		return false
-	}
-	lastRenewCheck[domain] = now
-	_, ok := h.getCertPEMCached(dir, domain, future)
-	return !ok
-}
-
-func serveKeyPair(w http.ResponseWriter, r *http.Request, p *keyPair) {
-	w.Header().Set("Content-Type", "text/plain")
-	switch r.URL.Query().Get("type") {
-	case "", "crt", "cert":
-		w.Write(p.certPEM)
-	case "key":
-		w.Write(p.keyPEM)
-	case "pair":
-		w.Write(p.keyPEM)
-		w.Write(p.certPEM)
-	default:
-		http.Error(w, `invalid type; want "cert" (default), "key", or "pair"`, 400)
-	}
-}
-
-type keyPair struct {
-	certPEM []byte
-	keyPEM  []byte
-	cached  bool
-}
-
-func keyFile(dir, domain string) string  { return filepath.Join(dir, domain+".key") }
-func certFile(dir, domain string) string { return filepath.Join(dir, domain+".crt") }
-
-// getCertPEMCached returns a non-nil keyPair and true if a cached
-// keypair for domain exists on disk in dir that is valid at the
-// provided now time.
-func (h *Handler) getCertPEMCached(dir, domain string, now time.Time) (p *keyPair, ok bool) {
-	if keyPEM, err := os.ReadFile(keyFile(dir, domain)); err == nil {
-		certPEM, _ := os.ReadFile(certFile(dir, domain))
-		if validCertPEM(domain, keyPEM, certPEM, now) {
-			return &keyPair{certPEM: certPEM, keyPEM: keyPEM, cached: true}, true
-		}
-	}
-	return nil, false
-}
-
-func (h *Handler) getCertPEM(ctx context.Context, logf logger.Logf, traceACME func(interface{}), dir, domain string, now time.Time) (*keyPair, error) {
-	acmeMu.Lock()
-	defer acmeMu.Unlock()
-
-	if p, ok := h.getCertPEMCached(dir, domain, now); ok {
-		return p, nil
-	}
-
-	key, err := acmeKey(dir)
-	if err != nil {
-		return nil, fmt.Errorf("acmeKey: %w", err)
-	}
-	ac := &acme.Client{Key: key}
-
-	a, err := ac.GetReg(ctx, "" /* pre-RFC param */)
-	switch {
-	case err == nil:
-		// Great, already registered.
-		logf("already had ACME account.")
-	case err == acme.ErrNoAccount:
-		a, err = ac.Register(ctx, new(acme.Account), acme.AcceptTOS)
-		if err == acme.ErrAccountAlreadyExists {
-			// Potential race. Double check.
-			a, err = ac.GetReg(ctx, "" /* pre-RFC param */)
-		}
-		if err != nil {
-			return nil, fmt.Errorf("acme.Register: %w", err)
-		}
-		logf("registered ACME account.")
-		traceACME(a)
-	default:
-		return nil, fmt.Errorf("acme.GetReg: %w", err)
-
-	}
-	if a.Status != acme.StatusValid {
-		return nil, fmt.Errorf("unexpected ACME account status %q", a.Status)
-	}
-
-	// Before hitting LetsEncrypt, see if this is a domain that Tailscale will do DNS challenges for.
-	st := h.b.StatusWithoutPeers()
-	if err := checkCertDomain(st, domain); err != nil {
-		return nil, err
-	}
-
-	order, err := ac.AuthorizeOrder(ctx, []acme.AuthzID{{Type: "dns", Value: domain}})
-	if err != nil {
-		return nil, err
-	}
-	traceACME(order)
-
-	for _, aurl := range order.AuthzURLs {
-		az, err := ac.GetAuthorization(ctx, aurl)
-		if err != nil {
-			return nil, err
-		}
-		traceACME(az)
-		for _, ch := range az.Challenges {
-			if ch.Type == "dns-01" {
-				rec, err := ac.DNS01ChallengeRecord(ch.Token)
-				if err != nil {
-					return nil, err
-				}
-				key := "_acme-challenge." + domain
-
-				var resolver net.Resolver
-				var ok bool
-				txts, _ := resolver.LookupTXT(ctx, key)
-				for _, txt := range txts {
-					if txt == rec {
-						ok = true
-						logf("TXT record already existed")
-						break
-					}
-				}
-				if !ok {
-					err = h.b.SetDNS(ctx, key, rec)
-					if err != nil {
-						return nil, fmt.Errorf("SetDNS %q => %q: %w", key, rec, err)
-					}
-					logf("did SetDNS")
-				}
-
-				chal, err := ac.Accept(ctx, ch)
-				if err != nil {
-					return nil, fmt.Errorf("Accept: %v", err)
-				}
-				traceACME(chal)
-				break
-			}
-		}
-	}
-
-	wait0 := time.Now()
-	orderURI := order.URI
-	for {
-		order, err = ac.WaitOrder(ctx, orderURI)
-		if err == nil {
-			break
-		}
-		if oe, ok := err.(*acme.OrderError); ok && oe.Status == acme.StatusInvalid {
-			if time.Since(wait0) > 2*time.Minute {
-				return nil, errors.New("timeout waiting for order to not be invalid")
-			}
-			log.Printf("order invalid; waiting...")
-			select {
-			case <-time.After(5 * time.Second):
-				continue
-			case <-ctx.Done():
-				return nil, ctx.Err()
-			}
-		}
-		return nil, fmt.Errorf("WaitOrder: %v", err)
-	}
-	traceACME(order)
-
-	certPrivKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	if err != nil {
-		return nil, err
-	}
-	var privPEM bytes.Buffer
-	if err := encodeECDSAKey(&privPEM, certPrivKey); err != nil {
-		return nil, err
-	}
-	if err := ioutil.WriteFile(keyFile(dir, domain), privPEM.Bytes(), 0600); err != nil {
-		return nil, err
-	}
-
-	csr, err := certRequest(certPrivKey, domain, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	der, _, err := ac.CreateOrderCert(ctx, order.FinalizeURL, csr, true)
-	if err != nil {
-		return nil, fmt.Errorf("CreateOrder: %v", err)
-	}
-
-	var certPEM bytes.Buffer
-	for _, b := range der {
-		pb := &pem.Block{Type: "CERTIFICATE", Bytes: b}
-		if err := pem.Encode(&certPEM, pb); err != nil {
-			return nil, err
-		}
-	}
-	if err := ioutil.WriteFile(certFile(dir, domain), certPEM.Bytes(), 0644); err != nil {
-		return nil, err
-	}
-
-	return &keyPair{certPEM: certPEM.Bytes(), keyPEM: privPEM.Bytes()}, nil
-}
-
-// certRequest generates a CSR for the given common name cn and optional SANs.
-func certRequest(key crypto.Signer, cn string, ext []pkix.Extension, san ...string) ([]byte, error) {
-	req := &x509.CertificateRequest{
-		Subject:         pkix.Name{CommonName: cn},
-		DNSNames:        san,
-		ExtraExtensions: ext,
-	}
-	return x509.CreateCertificateRequest(rand.Reader, req, key)
-}
-
-func encodeECDSAKey(w io.Writer, key *ecdsa.PrivateKey) error {
-	b, err := x509.MarshalECPrivateKey(key)
-	if err != nil {
-		return err
-	}
-	pb := &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}
-	return pem.Encode(w, pb)
-}
-
-// parsePrivateKey is a copy of x/crypto/acme's parsePrivateKey.
-//
-// Attempt to parse the given private key DER block. OpenSSL 0.9.8 generates
-// PKCS#1 private keys by default, while OpenSSL 1.0.0 generates PKCS#8 keys.
-// OpenSSL ecparam generates SEC1 EC private keys for ECDSA. We try all three.
-//
-// Inspired by parsePrivateKey in crypto/tls/tls.go.
-func parsePrivateKey(der []byte) (crypto.Signer, error) {
-	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
-		return key, nil
-	}
-	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
-		switch key := key.(type) {
-		case *rsa.PrivateKey:
-			return key, nil
-		case *ecdsa.PrivateKey:
-			return key, nil
-		default:
-			return nil, errors.New("acme/autocert: unknown private key type in PKCS#8 wrapping")
-		}
-	}
-	if key, err := x509.ParseECPrivateKey(der); err == nil {
-		return key, nil
-	}
-
-	return nil, errors.New("acme/autocert: failed to parse private key")
-}
-
-func acmeKey(dir string) (crypto.Signer, error) {
-	pemName := filepath.Join(dir, "acme-account.key.pem")
-	if v, err := ioutil.ReadFile(pemName); err == nil {
-		priv, _ := pem.Decode(v)
-		if priv == nil || !strings.Contains(priv.Type, "PRIVATE") {
-			return nil, errors.New("acme/autocert: invalid account key found in cache")
-		}
-		return parsePrivateKey(priv.Bytes)
-	}
-
-	privKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	if err != nil {
-		return nil, err
-	}
-	var pemBuf bytes.Buffer
-	if err := encodeECDSAKey(&pemBuf, privKey); err != nil {
-		return nil, err
-	}
-	if err := ioutil.WriteFile(pemName, pemBuf.Bytes(), 0600); err != nil {
-		return nil, err
-	}
-	return privKey, nil
-}
-
-func validCertPEM(domain string, keyPEM, certPEM []byte, now time.Time) bool {
-	if len(keyPEM) == 0 || len(certPEM) == 0 {
-		return false
-	}
-	tlsCert, err := tls.X509KeyPair(certPEM, keyPEM)
-	if err != nil {
-		return false
-	}
-	var leaf *x509.Certificate
-	intermediates := x509.NewCertPool()
-	for i, certDER := range tlsCert.Certificate {
-		cert, err := x509.ParseCertificate(certDER)
-		if err != nil {
-			return false
-		}
-		if i == 0 {
-			leaf = cert
-		} else {
-			intermediates.AddCert(cert)
-		}
-	}
-	if leaf == nil {
-		return false
-	}
-	_, err = leaf.Verify(x509.VerifyOptions{
-		DNSName:       domain,
-		CurrentTime:   now,
-		Intermediates: intermediates,
-	})
-	return err == nil
-}
-
-func checkCertDomain(st *ipnstate.Status, domain string) error {
-	if domain == "" {
-		return errors.New("missing domain name")
-	}
-	for _, d := range st.CertDomains {
-		if d == domain {
-			return nil
-		}
-	}
-	// Transitional way while server doesn't yet populate CertDomains: also permit the client
-	// attempting Self.DNSName.
-	okay := st.CertDomains[:len(st.CertDomains):len(st.CertDomains)]
-	if st.Self != nil {
-		if v := strings.Trim(st.Self.DNSName, "."); v != "" {
-			if v == domain {
-				return nil
-			}
-			okay = append(okay, v)
-		}
-	}
-	switch len(okay) {
-	case 0:
-		return errors.New("your Tailscale account does not support getting TLS certs")
-	case 1:
-		return fmt.Errorf("invalid domain %q; only %q is permitted", domain, okay[0])
-	default:
-		return fmt.Errorf("invalid domain %q; must be one of %q", domain, okay)
-	}
-}

ipn/localapi/disabled_stubs.go

@@ -1,17 +0,0 @@
-// 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.
-
-//go:build ios || android
-// +build ios android
-
-package localapi
-
-import (
-	"net/http"
-	"runtime"
-)
-
-func (h *Handler) serveCert(w http.ResponseWriter, r *http.Request) {
-	http.Error(w, "disabled on "+runtime.GOOS, http.StatusNotFound)
-}

ipn/localapi/localapi.go

@@ -30,7 +30,6 @@ import (
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
-	"tailscale.com/version"
 )
 
 func randHex(n int) string {
@@ -65,7 +64,6 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "server has no local backend", http.StatusInternalServerError)
 		return
 	}
-	w.Header().Set("Tailscale-Version", version.Long)
 	if h.RequiredPassword != "" {
 		_, pass, ok := r.BasicAuth()
 		if !ok {
@@ -85,10 +83,6 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h.serveFilePut(w, r)
 		return
 	}
-	if strings.HasPrefix(r.URL.Path, "/localapi/v0/cert/") {
-		h.serveCert(w, r)
-		return
-	}
 	switch r.URL.Path {
 	case "/localapi/v0/whois":
 		h.serveWhoIs(w, r)
@@ -106,10 +100,6 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h.serveBugReport(w, r)
 	case "/localapi/v0/file-targets":
 		h.serveFileTargets(w, r)
-	case "/localapi/v0/set-dns":
-		h.serveSetDNS(w, r)
-	case "/localapi/v0/derpmap":
-		h.serveDERPMap(w, r)
 	case "/":
 		io.WriteString(w, "tailscaled\n")
 	default:
@@ -272,7 +262,7 @@ func (h *Handler) serveFiles(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "file access denied", http.StatusForbidden)
 		return
 	}
-	suffix := strings.TrimPrefix(r.URL.EscapedPath(), "/localapi/v0/files/")
+	suffix := strings.TrimPrefix(r.URL.Path, "/localapi/v0/files/")
 	if suffix == "" {
 		if r.Method != "GET" {
 			http.Error(w, "want GET to list files", 400)
@@ -392,36 +382,6 @@ func (h *Handler) serveFilePut(w http.ResponseWriter, r *http.Request) {
 	rp.ServeHTTP(w, outReq)
 }
 
-func (h *Handler) serveSetDNS(w http.ResponseWriter, r *http.Request) {
-	if !h.PermitWrite {
-		http.Error(w, "access denied", http.StatusForbidden)
-		return
-	}
-	if r.Method != "POST" {
-		http.Error(w, "want POST", 400)
-		return
-	}
-	ctx := r.Context()
-	err := h.b.SetDNS(ctx, r.FormValue("name"), r.FormValue("value"))
-	if err != nil {
-		writeErrorJSON(w, err)
-		return
-	}
-	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(struct{}{})
-}
-
-func (h *Handler) serveDERPMap(w http.ResponseWriter, r *http.Request) {
-	if r.Method != "GET" {
-		http.Error(w, "want GET", 400)
-		return
-	}
-	w.Header().Set("Content-Type", "application/json")
-	e := json.NewEncoder(w)
-	e.SetIndent("", "\t")
-	e.Encode(h.b.DERPMap())
-}
-
 var dialPeerTransportOnce struct {
 	sync.Once
 	v *http.Transport
@@ -430,7 +390,7 @@ var dialPeerTransportOnce struct {
 func getDialPeerTransport(b *ipnlocal.LocalBackend) *http.Transport {
 	dialPeerTransportOnce.Do(func() {
 		t := http.DefaultTransport.(*http.Transport).Clone()
-		t.Dial = nil
+		t.Dial = nil //lint:ignore SA1019 yes I know I'm setting it to nil defensively
 		dialer := net.Dialer{
 			Timeout:   30 * time.Second,
 			KeepAlive: 30 * time.Second,

ipn/message.go

@@ -104,9 +104,7 @@ func NewBackendServer(logf logger.Logf, b Backend, sendNotifyMsg func(Notify)) *
 		b:             b,
 		sendNotifyMsg: sendNotifyMsg,
 	}
-	// b may be nil if the BackendServer is being created just to
-	// encapsulate and send an error message.
-	if sendNotifyMsg != nil && b != nil {
+	if sendNotifyMsg != nil {
 		b.SetNotifyCallback(bs.send)
 	}
 	return bs

ipn/message_test.go

@@ -187,17 +187,3 @@ func TestClientServer(t *testing.T) {
 	})
 	flushUntil(Running)
 }
-
-func TestNilBackend(t *testing.T) {
-	var called *Notify
-	bs := NewBackendServer(t.Logf, nil, func(n Notify) {
-		called = &n
-	})
-	bs.SendErrorMessage("Danger, Will Robinson!")
-	if called == nil {
-		t.Errorf("expect callback to be called, wasn't")
-	}
-	if called.ErrMessage == nil || *called.ErrMessage != "Danger, Will Robinson!" {
-		t.Errorf("callback got wrong error: %v", called.ErrMessage)
-	}
-}

ipn/prefs.go

@@ -25,16 +25,10 @@ import (
 
 //go:generate go run tailscale.com/cmd/cloner -type=Prefs -output=prefs_clone.go
 
-// DefaultControlURL is the URL base of the control plane
+// DefaultControlURL returns the URL base of the control plane
 // ("coordination server") for use when no explicit one is configured.
 // The default control plane is the hosted version run by Tailscale.com.
-const DefaultControlURL = "https://controlplane.tailscale.com"
-
-// IsLoginServerSynonym reports whether a URL is a drop-in replacement
-// for the primary Tailscale login server.
-func IsLoginServerSynonym(val interface{}) bool {
-	return val == "https://login.tailscale.com" || val == "https://controlplane.tailscale.com"
-}
+const DefaultControlURL = "https://login.tailscale.com"
 
 // Prefs are the user modifiable settings of the Tailscale node agent.
 type Prefs struct {
@@ -411,16 +405,6 @@ func (p *Prefs) ControlURLOrDefault() string {
 	return DefaultControlURL
 }
 
-// AdminPageURL returns the admin web site URL for the current ControlURL.
-func (p *Prefs) AdminPageURL() string {
-	url := p.ControlURLOrDefault()
-	if IsLoginServerSynonym(url) {
-		// TODO(crawshaw): In future release, make this https://console.tailscale.com
-		url = "https://login.tailscale.com"
-	}
-	return url + "/admin/machines"
-}
-
 // PrefsFromBytes deserializes Prefs from a JSON blob. If
 // enforceDefaults is true, Prefs.RouteAll and Prefs.AllowSingleHosts
 // are forced on.

ipn/prefs_test.go

@@ -92,13 +92,13 @@ func TestPrefsEqual(t *testing.T) {
 		},
 
 		{
-			&Prefs{ControlURL: "https://controlplane.tailscale.com"},
+			&Prefs{ControlURL: "https://login.tailscale.com"},
 			&Prefs{ControlURL: "https://login.private.co"},
 			false,
 		},
 		{
-			&Prefs{ControlURL: "https://controlplane.tailscale.com"},
-			&Prefs{ControlURL: "https://controlplane.tailscale.com"},
+			&Prefs{ControlURL: "https://login.tailscale.com"},
+			&Prefs{ControlURL: "https://login.tailscale.com"},
 			true,
 		},
 
@@ -324,7 +324,7 @@ func TestBasicPrefs(t *testing.T) {
 	tstest.PanicOnLog()
 
 	p := Prefs{
-		ControlURL: "https://controlplane.tailscale.com",
+		ControlURL: "https://login.tailscale.com",
 	}
 	checkPrefs(t, p)
 }
@@ -336,7 +336,7 @@ func TestPrefsPersist(t *testing.T) {
 		LoginName: "test@example.com",
 	}
 	p := Prefs{
-		ControlURL: "https://controlplane.tailscale.com",
+		ControlURL: "https://login.tailscale.com",
 		CorpDNS:    true,
 		Persist:    &c,
 	}

ipn/store.go

@@ -67,6 +67,9 @@ func (s *MemoryStore) String() string { return "MemoryStore" }
 func (s *MemoryStore) ReadState(id StateKey) ([]byte, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	if s.cache == nil {
+		s.cache = map[StateKey][]byte{}
+	}
 	bs, ok := s.cache[id]
 	if !ok {
 		return nil, ErrStateNotExist

logpolicy/logpolicy.go

@@ -128,13 +128,6 @@ func (l logWriter) Write(buf []byte) (int, error) {
 // logsDir returns the directory to use for log configuration and
 // buffer storage.
 func logsDir(logf logger.Logf) string {
-	if d := os.Getenv("TS_LOGS_DIR"); d != "" {
-		fi, err := os.Stat(d)
-		if err == nil && fi.IsDir() {
-			return d
-		}
-	}
-
 	// STATE_DIRECTORY is set by systemd 240+ but we support older
 	// systems-d. For example, Ubuntu 18.04 (Bionic Beaver) is 237.
 	systemdStateDir := os.Getenv("STATE_DIRECTORY")
@@ -187,10 +180,6 @@ func runningUnderSystemd() bool {
 	return false
 }
 
-func redirectStderrToLogPanics() bool {
-	return runningUnderSystemd() || os.Getenv("TS_PLEASE_PANIC") != ""
-}
-
 // tryFixLogStateLocation is a temporary fixup for
 // https://github.com/tailscale/tailscale/issues/247 . We accidentally
 // wrote logging state files to /, and then later to $CACHE_DIRECTORY
@@ -439,14 +428,9 @@ func New(collection string) *Policy {
 		c.HTTPC = &http.Client{Transport: newLogtailTransport(u.Host)}
 	}
 
-	filchBuf, filchErr := filch.New(filepath.Join(dir, cmdName), filch.Options{
-		ReplaceStderr: redirectStderrToLogPanics(),
-	})
+	filchBuf, filchErr := filch.New(filepath.Join(dir, cmdName), filch.Options{})
 	if filchBuf != nil {
 		c.Buffer = filchBuf
-		if filchBuf.OrigStderr != nil {
-			c.Stderr = filchBuf.OrigStderr
-		}
 	}
 	lw := logtail.NewLogger(c, log.Printf)
 	log.SetFlags(0) // other logflags are set on console, not here

logtail/filch/filch.go

@@ -15,6 +15,7 @@ import (
 	"sync"
 )
 
+//lint:ignore U1000 work around false positive: https://github.com/dominikh/go-tools/issues/983
 var stderrFD = 2 // a variable for testing
 
 type Options struct {
@@ -30,15 +31,6 @@ type Filch struct {
 	alt       *os.File
 	altscan   *bufio.Scanner
 	recovered int64
-	// buf is an initial buffer for altscan.
-	// As of August 2021, 99.96% of all log lines
-	// are below 4096 bytes in length.
-	// Since this cutoff is arbitrary, instead of using 4096,
-	// we subtract off the size of the rest of the struct
-	// so that the whole struct takes 4096 bytes
-	// (less on 32 bit platforms).
-	// This reduces allocation waste.
-	buf [4096 - 48]byte
 }
 
 // TryReadline implements the logtail.Buffer interface.
@@ -62,7 +54,6 @@ func (f *Filch) TryReadLine() ([]byte, error) {
 		return nil, err
 	}
 	f.altscan = bufio.NewScanner(f.alt)
-	f.altscan.Buffer(f.buf[:], bufio.MaxScanTokenSize)
 	f.altscan.Split(splitLines)
 	return f.scan()
 }
@@ -198,7 +189,6 @@ func New(filePrefix string, opts Options) (f *Filch, err error) {
 	}
 	if f.recovered > 0 {
 		f.altscan = bufio.NewScanner(f.alt)
-		f.altscan.Buffer(f.buf[:], bufio.MaxScanTokenSize)
 		f.altscan.Split(splitLines)
 	}
 

logtail/filch/filch_test.go

@@ -12,7 +12,6 @@ import (
 	"strings"
 	"testing"
 	"unicode"
-	"unsafe"
 )
 
 type filchTest struct {
@@ -170,10 +169,3 @@ func TestFilchStderr(t *testing.T) {
 		t.Errorf("unexpected write to fake stderr: %s", b)
 	}
 }
-
-func TestSizeOf(t *testing.T) {
-	s := unsafe.Sizeof(Filch{})
-	if s > 4096 {
-		t.Fatalf("Filch{} has size %d on %v, decrease size of buf field", s, runtime.GOARCH)
-	}
-}

logtail/filch/filch_unix.go

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !windows
-// +build !windows
+//+build !windows
 
 package filch
 

logtail/logtail.go

@@ -15,7 +15,6 @@ import (
 	"net/http"
 	"os"
 	"strconv"
-	"sync/atomic"
 	"time"
 
 	"tailscale.com/logtail/backoff"
@@ -73,7 +72,7 @@ func NewLogger(cfg Config, logf tslogger.Logf) *Logger {
 	}
 	l := &Logger{
 		stderr:         cfg.Stderr,
-		stderrLevel:    int64(cfg.StderrLevel),
+		stderrLevel:    cfg.StderrLevel,
 		httpc:          cfg.HTTPC,
 		url:            cfg.BaseURL + "/c/" + cfg.Collection + "/" + cfg.PrivateID.String(),
 		lowMem:         cfg.LowMemory,
@@ -104,7 +103,7 @@ func NewLogger(cfg Config, logf tslogger.Logf) *Logger {
 // logging facilities and uploading to a log server.
 type Logger struct {
 	stderr         io.Writer
-	stderrLevel    int64 // accessed atomically
+	stderrLevel    int
 	httpc          *http.Client
 	url            string
 	lowMem         bool
@@ -118,17 +117,18 @@ type Logger struct {
 	bo             *backoff.Backoff
 	zstdEncoder    Encoder
 	uploadCancel   func()
-	explainedRaw   bool
 
 	shutdownStart chan struct{} // closed when shutdown begins
-	shutdownDone  chan struct{} // closed when shutdown complete
+	shutdownDone  chan struct{} // closd when shutdown complete
 }
 
 // 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) {
-	atomic.StoreInt64(&l.stderrLevel, int64(level))
+	l.stderrLevel = level
 }
 
 // SetLinkMonitor sets the optional the link monitor.
@@ -200,11 +200,9 @@ func (l *Logger) drainBlock() (shuttingDown bool) {
 }
 
 // drainPending drains and encodes a batch of logs from the buffer for upload.
-// It uses scratch as its initial buffer.
 // If no logs are available, drainPending blocks until logs are available.
-func (l *Logger) drainPending(scratch []byte) (res []byte) {
-	buf := bytes.NewBuffer(scratch[:0])
-	buf.WriteByte('[')
+func (l *Logger) drainPending() (res []byte) {
+	buf := new(bytes.Buffer)
 	entries := 0
 
 	var batchDone bool
@@ -233,26 +231,31 @@ func (l *Logger) drainPending(scratch []byte) (res []byte) {
 			// outside of the logtail logger. Encode it.
 			// Do not add a client time, as it could have been
 			// been written a long time ago.
-			if !l.explainedRaw {
-				fmt.Fprintf(l.stderr, "RAW-STDERR: ***\n")
-				fmt.Fprintf(l.stderr, "RAW-STDERR: *** Lines prefixed with RAW-STDERR below bypassed logtail and probably come from a previous run of the program\n")
-				fmt.Fprintf(l.stderr, "RAW-STDERR: ***\n")
-				fmt.Fprintf(l.stderr, "RAW-STDERR:\n")
-				l.explainedRaw = true
-			}
-			fmt.Fprintf(l.stderr, "RAW-STDERR: %s", b)
 			b = l.encodeText(b, true)
 		}
 
-		if entries > 0 {
+		switch {
+		case entries == 0:
+			buf.Write(b)
+		case entries == 1:
+			buf2 := new(bytes.Buffer)
+			buf2.WriteByte('[')
+			buf2.Write(buf.Bytes())
+			buf2.WriteByte(',')
+			buf2.Write(b)
+			buf.Reset()
+			buf.Write(buf2.Bytes())
+		default:
 			buf.WriteByte(',')
+			buf.Write(b)
 		}
-		buf.Write(b)
 		entries++
 	}
 
-	buf.WriteByte(']')
-	if buf.Len() <= len("[]") {
+	if entries > 1 {
+		buf.WriteByte(']')
+	}
+	if buf.Len() == 0 {
 		return nil
 	}
 	return buf.Bytes()
@@ -262,9 +265,8 @@ func (l *Logger) drainPending(scratch []byte) (res []byte) {
 func (l *Logger) uploading(ctx context.Context) {
 	defer close(l.shutdownDone)
 
-	scratch := make([]byte, 4096) // reusable buffer to write into
 	for {
-		body := l.drainPending(scratch)
+		body := l.drainPending()
 		origlen := -1 // sentinel value: uncompressed
 		// Don't attempt to compress tiny bodies; not worth the CPU cycles.
 		if l.zstdEncoder != nil && len(body) > 256 {
@@ -512,7 +514,7 @@ func (l *Logger) Write(buf []byte) (int, error) {
 		return 0, nil
 	}
 	level, buf := parseAndRemoveLogLevel(buf)
-	if l.stderr != nil && l.stderr != ioutil.Discard && int64(level) <= atomic.LoadInt64(&l.stderrLevel) {
+	if l.stderr != nil && l.stderr != ioutil.Discard && level <= l.stderrLevel {
 		if buf[len(buf)-1] == '\n' {
 			l.stderr.Write(buf)
 		} else {