tka: implement machinery for node-key denylist

Signed-off-by: Tom DNetto <tom@tailscale.com>

.bencher/config.yaml

@@ -0,0 +1 @@
+suppress_failure_on_regression: true

.gitattributes

@@ -1 +1,2 @@
 go.mod filter=go-mod
+*.go  diff=golang

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,8 +0,0 @@
----
-name: Bug report
-about: Create a bug report
-title: ''
-labels: 'needs-triage'
-assignees: ''
-
----

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,75 @@
+name: Bug report
+description: File a bug report
+labels: [needs-triage, bug]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Please check if your bug is [already filed](https://github.com/tailscale/tailscale/issues).
+        Have an urgent issue? Let us know by emailing us at <support@tailscale.com>.
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: What is the issue?
+      description: What happened? What did you expect to happen?
+      placeholder: oh no
+    validations:
+      required: true
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to reproduce
+      description: What are the steps you took that hit this issue?
+    validations:
+      required: false
+  - type: textarea
+    id: changes
+    attributes:
+      label: Are there any recent changes that introduced the issue?
+      description: If so, what are those changes?
+    validations:
+      required: false
+  - type: dropdown
+    id: os
+    attributes:
+      label: OS
+      description: What OS are you using? You may select more than one.
+      multiple: true
+      options:
+        - Linux
+        - macOS
+        - Windows
+        - iOS
+        - Android
+        - Synology
+        - Other
+    validations:
+      required: false
+  - type: input
+    id: os-version
+    attributes:
+      label: OS version
+      description: What OS version are you using?
+      placeholder: e.g., Debian 11.0, macOS Big Sur 11.6, Synology DSM 7
+    validations:
+      required: false
+  - type: input
+    id: ts-version
+    attributes:
+      label: Tailscale version
+      description: What Tailscale version are you using?
+      placeholder: e.g., 1.14.4
+    validations:
+      required: false
+  - type: input
+    id: bug-report
+    attributes:
+      label: Bug report
+      description: Please run [`tailscale bugreport`](https://tailscale.com/kb/1080/cli/?q=Cli#bugreport) and share the bug identifier. The identifier is a random string which allows Tailscale support to locate your account and gives a point to focus on when looking for errors.
+      placeholder: e.g., BUG-1b7641a16971a9cd75822c0ed8043fee70ae88cf05c52981dc220eb96a5c49a8-20210427151443Z-fbcd4fd3a4b7ad94
+    validations:
+      required: false
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for filing a bug report!

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1,8 @@
 blank_issues_enabled: true
 contact_links:
-  - name: Support and Product Questions
+  - name: Support
+    url: https://tailscale.com/contact/support/
+    about: Contact us for support
+  - name: Troubleshooting
     url: https://tailscale.com/kb/1023/troubleshooting
-    about: Please send support questions and questions about the Tailscale product to support@tailscale.com
+    about: Troubleshoot common issues

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,7 +0,0 @@
----
-name: Feature request
-about: Suggest an idea for this project
-title: ''
-labels: 'needs-triage'
-assignees: ''
----

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,42 @@
+name: Feature request
+description: Propose a new feature
+title: "FR: "
+labels: [needs-triage, fr]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Please check if your feature request is [already filed](https://github.com/tailscale/tailscale/issues).
+        Tell us about your idea!
+  - type: textarea
+    id: problem
+    attributes:
+      label: What are you trying to do?
+      description: Tell us about the problem you're trying to solve.
+    validations:
+      required: false
+  - type: textarea
+    id: solution
+    attributes:
+      label: How should we solve this?
+      description: If you have an idea of how you'd like to see this feature work, let us know.
+    validations:
+      required: false
+  - type: textarea
+    id: alternative
+    attributes:
+      label: What is the impact of not solving this?
+      description: (How) Are you currently working around the issue?
+    validations:
+      required: false
+  - type: textarea
+    id: context
+    attributes:
+      label: Anything else?
+      description: Any additional context to share, e.g., links
+    validations:
+      required: false
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for filing a feature request!

.github/dependabot.yml

@@ -0,0 +1,21 @@
+# Documentation for this file can be found at:
+# https://docs.github.com/en/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/configuration-options-for-dependency-updates
+version: 2
+updates:
+  ## Disabled between releases. We reenable it briefly after every
+  ## stable release, pull in all changes, and close it again so that
+  ## the tree remains more stable during development and the upstream
+  ## changes have time to soak before the next release.
+  # - package-ecosystem: "gomod"
+  #   directory: "/"
+  #   schedule:
+  #     interval: "daily"
+  #   commit-message:
+  #     prefix: "go.mod:"
+  #   open-pull-requests-limit: 100
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: ".github:"

.github/licenses.tmpl

@@ -0,0 +1,17 @@
+# Tailscale CLI and daemon dependencies
+
+The following open source dependencies are used to build the [tailscale][] and
+[tailscaled][] commands. These are primarily used on Linux and BSD variants as
+well as an [option for macOS][].
+
+[tailscale]: https://pkg.go.dev/tailscale.com/cmd/tailscale
+[tailscaled]: https://pkg.go.dev/tailscale.com/cmd/tailscaled
+[option for macOS]: https://tailscale.com/kb/1065/macos-variants/
+
+## Go Packages
+
+Some packages may only be included on certain architectures or operating systems.
+
+{{ range . }}
+ - [{{.Name}}](https://pkg.go.dev/{{.Name}}) ([{{.LicenseName}}]({{.LicenseURL}}))
+{{- end }}

.github/workflows/cifuzz.yml

@@ -0,0 +1,31 @@
+name: CIFuzz
+on: [pull_request]
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  Fuzzing:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Build Fuzzers
+      id: build
+      uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
+      with:
+        oss-fuzz-project-name: 'tailscale'
+        dry-run: false
+        language: go
+    - name: Run Fuzzers
+      uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
+      with:
+        oss-fuzz-project-name: 'tailscale'
+        fuzz-seconds: 300
+        dry-run: false
+        language: go
+    - name: Upload Crash
+      uses: actions/upload-artifact@v3
+      if: failure() && steps.build.outcome == 'success'
+      with:
+        name: artifacts
+        path: ./out/artifacts

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,75 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main, release-branch/* ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ main ]
+  schedule:
+    - cron: '31 14 * * 5'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v3
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/cross-darwin.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,16 +19,15 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: macOS build cmd
       env:
         GOOS: darwin
@@ -37,6 +40,12 @@ jobs:
         GOARCH: amd64
       run: for d in $(go list -f '{{if .TestGoFiles}}{{.Dir}}{{end}}' ./... ); do (echo $d; cd $d && go test -c ); done
 
+    - name: iOS build most
+      env:
+        GOOS: ios
+        GOARCH: arm64
+      run: go install ./ipn/... ./wgengine/ ./types/... ./control/controlclient
+
     - uses: k0kubun/action-slack@v2.0.0
       with:
         payload: |

.github/workflows/cross-freebsd.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,16 +19,15 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: FreeBSD build cmd
       env:
         GOOS: freebsd

.github/workflows/cross-openbsd.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,16 +19,15 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: OpenBSD build cmd
       env:
         GOOS: openbsd

.github/workflows/cross-wasm.yml

@@ -1,4 +1,4 @@
-name: Windows race
+name: Wasm-Cross
 
 on:
   push:
@@ -8,35 +8,38 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
-  test:
-    runs-on: windows-latest
+  build:
+    runs-on: ubuntu-latest
 
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
-    - name: Install Go
-      uses: actions/setup-go@v2
+    - name: Set up Go
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16.x
+        go-version-file: go.mod
+      id: go
 
-    - name: Checkout code
-      uses: actions/checkout@v2
+    - name: Wasm client build
+      env:
+        GOOS: js
+        GOARCH: wasm
+      run: go build ./cmd/tsconnect/wasm ./cmd/tailscale/cli
 
-    - name: Restore Cache
-      uses: actions/cache@v2
-      with:
-        path: ~/go/pkg/mod
-        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
-        restore-keys: |
-          ${{ runner.os }}-go-
-
-    - name: Test with -race flag
-      # Don't use -bench=. -benchtime=1x.
-      # Somewhere in the layers (powershell?)
-      # the equals signs cause great confusion.
-      run: go test -race -bench . -benchtime 1x ./...
+    - name: tsconnect static build
+      # Use our custom Go toolchain, we set build tags (to control binary size)
+      # that depend on it.
+      run: |
+        ./tool/go run ./cmd/tsconnect --fast-compression build
+        ./tool/go run ./cmd/tsconnect build-pkg
 
     - uses: k0kubun/action-slack@v2.0.0
       with:
@@ -52,4 +55,3 @@ jobs:
       env:
         SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
       if: failure() && github.event_name == 'push'
-

.github/workflows/cross-windows.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,16 +19,15 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: Windows build cmd
       env:
         GOOS: windows

.github/workflows/depaware.yml

@@ -8,21 +8,25 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     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@v1
+      uses: actions/checkout@v3
 
-    - name: depaware tailscaled
-      run: go run github.com/tailscale/depaware --check tailscale.com/cmd/tailscaled
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
 
-    - name: depaware tailscale
-      run: go run github.com/tailscale/depaware --check tailscale.com/cmd/tailscale
+    - name: depaware
+      run: go run github.com/tailscale/depaware --check
+        tailscale.com/cmd/tailscaled
+        tailscale.com/cmd/tailscale
+        tailscale.com/cmd/derper

.github/workflows/go-licenses.yml

@@ -0,0 +1,64 @@
+name: go-licenses
+
+on:
+  # run action when a change lands in the main branch which updates go.mod or
+  # our license template file. Also allow manual triggering.
+  push:
+    branches:
+      - main
+    paths:
+      - go.mod
+      - .github/licenses.tmpl
+      - .github/workflows/go-licenses.yml
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  tailscale:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+
+      - name: Install go-licenses
+        run: |
+          go install github.com/google/go-licenses@v1.2.2-0.20220825154955-5eedde1c6584
+
+      - name: Run go-licenses
+        env:
+          # include all build tags to include platform-specific dependencies
+          GOFLAGS: "-tags=android,cgo,darwin,freebsd,ios,js,linux,openbsd,wasm,windows"
+        run: |
+          [ -d licenses ] || mkdir licenses
+          go-licenses report tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled > licenses/tailscale.md --template .github/licenses.tmpl
+
+      - name: Get access token
+        uses: tibdex/github-app-token@f717b5ecd4534d3c4df4ce9b5c1c2214f0f7cd06 # v1.6.0
+        id: generate-token
+        with:
+          app_id: ${{ secrets.LICENSING_APP_ID }}
+          installation_id: ${{ secrets.LICENSING_APP_INSTALLATION_ID }}
+          private_key: ${{ secrets.LICENSING_APP_PRIVATE_KEY }}
+
+      - name: Send pull request
+        uses: peter-evans/create-pull-request@18f90432bedd2afd6a825469ffd38aa24712a91d #v4.1.1
+        with:
+          token: ${{ steps.generate-token.outputs.token }}
+          author: License Updater <noreply@tailscale.com>
+          committer: License Updater <noreply@tailscale.com>
+          branch: licenses/cli
+          commit-message: "licenses: update tailscale{,d} licenses"
+          title: "licenses: update tailscale{,d} licenses"
+          body: Triggered by ${{ github.repository }}@${{ github.sha }}
+          signoff: true
+          delete-branch: true
+          team-reviewers: opensource-license-reviewers

.github/workflows/go_generate.yml

@@ -9,26 +9,34 @@ on:
     branches:
       - "*"
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 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
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0
 
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+
       - 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 ./...
+          if [[ "${{github.ref}}" == release-branch/* ]]
+          then
+            pkgs=$(go list ./... | grep -v dnsfallback)
+          else
+            pkgs=$(go list ./... | grep -v dnsfallback)
+          fi
+          go generate $pkgs
           echo
           echo
           git diff --name-only --exit-code || (echo "The files above need updating. Please run 'go generate'."; exit 1)

.github/workflows/go_mod_tidy.yml

@@ -0,0 +1,35 @@
+name: go mod tidy
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - "*"
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+
+      - name: check 'go mod tidy' is clean
+        run: |
+          go mod tidy
+          echo
+          echo
+          git diff --name-only --exit-code || (echo "Please run 'go mod tidy'."; exit 1)

.github/workflows/license.yml

@@ -8,18 +8,22 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     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@v1
+      uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
 
     - name: Run license checker
       run: ./scripts/check_license_headers.sh .

.github/workflows/linux-race.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,22 +19,36 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: Basic build
       run: go build ./cmd/...
 
     - name: Run tests and benchmarks with -race flag on linux
       run: go test -race -bench=. -benchtime=1x ./...
 
+    - name: Check that no tracked files in the repo have been modified
+      run: git diff --no-ext-diff --name-only --exit-code || (echo "Build/test modified the files above."; exit 1)
+
+    - name: Check that no files have been added to the repo
+      run: |
+        # Note: The "error: pathspec..." you see below is normal!
+        # In the success case in which there are no new untracked files,
+        # git ls-files complains about the pathspec not matching anything.
+        # That's OK. It's not worth the effort to suppress. Please ignore it.
+        if git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*'
+        then
+          echo "Build/test created untracked files in the repo (file names above)."
+          exit 1
+        fi
+
     - uses: k0kubun/action-slack@v2.0.0
       with:
         payload: |

.github/workflows/linux.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,22 +19,50 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: Basic build
       run: go build ./cmd/...
 
+    - name: Build variants
+      run: |
+        go install --tags=ts_include_cli ./cmd/tailscaled
+        go install --tags=ts_omit_aws ./cmd/tailscaled
+
+    - name: Get QEMU
+      run: |
+        # The qemu in Ubuntu 20.04 (Focal) is too old; we need 5.x something
+        # to run Go binaries. 5.2.0 (Debian bullseye) empirically works, and
+        # use this PPA which brings in a modern qemu.
+        sudo add-apt-repository -y ppa:jacob/virtualisation
+        sudo apt-get -y update
+        sudo apt-get -y install qemu-user
+
     - name: Run tests on linux
       run: go test -bench=. -benchtime=1x ./...
 
+    - name: Check that no tracked files in the repo have been modified
+      run: git diff --no-ext-diff --name-only --exit-code || (echo "Build/test modified the files above."; exit 1)
+
+    - name: Check that no files have been added to the repo
+      run: |
+        # Note: The "error: pathspec..." you see below is normal!
+        # In the success case in which there are no new untracked files,
+        # git ls-files complains about the pathspec not matching anything.
+        # That's OK. It's not worth the effort to suppress. Please ignore it.
+        if git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*'
+        then
+          echo "Build/test created untracked files in the repo (file names above)."
+          exit 1
+        fi
+
     - uses: k0kubun/action-slack@v2.0.0
       with:
         payload: |

.github/workflows/linux32.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -15,22 +19,36 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version-file: go.mod
       id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
-
     - name: Basic build
       run: GOARCH=386 go build ./cmd/...
 
     - name: Run tests on linux
       run: GOARCH=386 go test -bench=. -benchtime=1x ./...
 
+    - name: Check that no tracked files in the repo have been modified
+      run: git diff --no-ext-diff --name-only --exit-code || (echo "Build/test modified the files above."; exit 1)
+
+    - name: Check that no files have been added to the repo
+      run: |
+        # Note: The "error: pathspec..." you see below is normal!
+        # In the success case in which there are no new untracked files,
+        # git ls-files complains about the pathspec not matching anything.
+        # That's OK. It's not worth the effort to suppress. Please ignore it.
+        if git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*'
+        then
+          echo "Build/test created untracked files in the repo (file names above)."
+          exit 1
+        fi
+
     - uses: k0kubun/action-slack@v2.0.0
       with:
         payload: |

.github/workflows/static-analysis.yml

@@ -0,0 +1,112 @@
+name: static-analysis
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  gofmt:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v3
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
+    - name: Run gofmt (goimports)
+      run: go run golang.org/x/tools/cmd/goimports -d --format-only .
+    - 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: ${{ secrets.SLACK_WEBHOOK_URL }}
+      if: failure() && github.event_name == 'push'
+
+  vet:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.19
+    - name: Check out code
+      uses: actions/checkout@v3
+    - name: Run go vet
+      run: go vet ./...
+    - uses: k0kubun/action-slack@v2.0.0
+      with:
+        payload: |
+          {
+            "attachments": [{
+              "text": "${{ 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: ${{ secrets.SLACK_WEBHOOK_URL }}
+      if: failure() && github.event_name == 'push'
+
+  staticcheck:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        goos: [linux, windows, darwin]
+        goarch: [amd64]
+        include:
+          - goos: windows
+            goarch: 386
+
+    steps:
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.19
+
+    - name: Check out code
+      uses: actions/checkout@v3
+
+    - name: Install staticcheck
+      run: "GOBIN=~/.local/bin go install honnef.co/go/tools/cmd/staticcheck"
+
+    - name: Print staticcheck version
+      run: "staticcheck -version"
+
+    - name: "Run staticcheck (${{ matrix.goos }}/${{ matrix.goarch }})"
+      env:
+        GOOS: ${{ matrix.goos }}
+        GOARCH: ${{ matrix.goarch }}
+      run: "staticcheck -- $(go list ./... | grep -v tempfork)"
+
+    - uses: k0kubun/action-slack@v2.0.0
+      with:
+        payload: |
+          {
+            "attachments": [{
+              "text": "${{ 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'

.github/workflows/staticcheck.yml

@@ -1,58 +0,0 @@
-name: staticcheck
-
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-    branches:
-      - '*'
-
-jobs:
-  build:
-    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@v1
-
-    - name: Run go vet
-      run: go vet ./...
-
-    - name: Install staticcheck
-      run: "GOBIN=~/.local/bin go install honnef.co/go/tools/cmd/staticcheck"
-
-    - name: Print staticcheck version
-      run: "staticcheck -version"
-
-    - name: Run staticcheck (linux/amd64)
-      run: "GOOS=linux GOARCH=amd64 staticcheck -- $(go list ./... | grep -v tempfork)"
-
-    - name: Run staticcheck (darwin/amd64)
-      run: "GOOS=darwin GOARCH=amd64 staticcheck -- $(go list ./... | grep -v tempfork)"
-
-    - name: Run staticcheck (windows/amd64)
-      run: "GOOS=windows GOARCH=amd64 staticcheck -- $(go list ./... | grep -v tempfork)"
-
-    - name: Run staticcheck (windows/386)
-      run: "GOOS=windows GOARCH=386 staticcheck -- $(go list ./... | grep -v tempfork)"
-
-    - uses: k0kubun/action-slack@v2.0.0
-      with:
-        payload: |
-          {
-            "attachments": [{
-              "text": "${{ 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'

.github/workflows/tsconnect-pkg-publish.yml

@@ -0,0 +1,30 @@
+name: "@tailscale/connect npm publish"
+
+on: workflow_dispatch
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Set up node
+        uses: actions/setup-node@v3
+        with:
+          node-version: "16.x"
+          registry-url: "https://registry.npmjs.org"
+
+      - name: Build package
+        # Build with build_dist.sh to ensure that version information is embedded.
+        # GOROOT is specified so that the Go/Wasm that is trigged by build-pk
+        # also picks up our custom Go toolchain.
+        run: |
+          ./build_dist.sh tailscale.com/cmd/tsconnect
+          GOROOT="${HOME}/.cache/tailscale-go" ./tsconnect build-pkg
+
+      - name: Publish
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.TSCONNECT_NPM_PUBLISH_AUTH_TOKEN }}
+        run: ./tool/yarn --cwd ./cmd/tsconnect/pkg publish --access public

.github/workflows/vm.yml

@@ -1,31 +1,36 @@
-name: "integration-vms"
+name: VM
 
 on:
   pull_request:
-    paths:
-      - "tstest/integration/vms/**"
-  release:
-    types: [ created ]
+    branches:
+      - '*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 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 ]
+  ubuntu2004-LTS-cloud-base:
+    runs-on: [ self-hosted, linux, vm ]
 
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
-      - name: Checkout Code
-        uses: actions/checkout@v1
+      - name: Set GOPATH
+        run: echo "GOPATH=$HOME/go" >> $GITHUB_ENV
 
-      - 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: Checkout Code
+        uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
 
       - name: Run VM tests
-        run: go test ./tstest/integration/vms -v -run-vm-tests
+        run: go test ./tstest/integration/vms -v -no-s3 -run-vm-tests -run=TestRunUbuntu2004
         env:
+          HOME: "/tmp"
           TMPDIR: "/tmp"
           XDG_CACHE_HOME: "/var/lib/ghrunner/cache"
 

.github/workflows/windows.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - '*'
 
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   test:
     runs-on: windows-latest
@@ -15,22 +19,29 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
+    - name: Checkout code
+      uses: actions/checkout@v3
 
     - name: Install Go
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16.x
-
-    - name: Checkout code
-      uses: actions/checkout@v2
+        go-version-file: go.mod
 
     - name: Restore Cache
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
-        path: ~/go/pkg/mod
-        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
-        restore-keys: |
-          ${{ runner.os }}-go-
+        # Note: unlike some other setups, this is only grabbing the mod download
+        # cache, rather than the whole mod directory, as the download cache
+        # contains zips that can be unpacked in parallel faster than they can be
+        # fetched and extracted by tar
+        path: |
+          ~/go/pkg/mod/cache
+          ~\AppData\Local\go-build
+
+        # The -2- here should be incremented when the scheme of data to be
+        # cached changes (e.g. path above changes).
+        # TODO(raggi): add a go version here.
+        key: ${{ runner.os }}-go-2-${{ hashFiles('**/go.sum') }}
 
     - name: Test
       # Don't use -bench=. -benchtime=1x.

.gitignore

@@ -5,6 +5,7 @@
 *.dll
 *.so
 *.dylib
+*.spk
 
 cmd/tailscale/tailscale
 cmd/tailscaled/tailscaled

ALPINE.txt

@@ -0,0 +1 @@
+3.16

Dockerfile

@@ -4,17 +4,11 @@
 
 ############################################################################
 #
-# WARNING: Tailscale is not yet officially supported in Docker,
-# Kubernetes, etc.
+# WARNING: Tailscale is not yet officially supported in container
+# environments, such as Docker and Kubernetes. Though it should work, we
+# don't regularly test it, and we know there are some feature limitations.
 #
-# It might work, but we don't regularly test it, and it's not as polished as
-# our currently supported platforms. This is provided for people who know
-# how Tailscale works and what they're doing.
-#
-# Our tracking bug for officially support container use cases is:
-#    https://github.com/tailscale/tailscale/issues/504
-#
-# Also, see the various bugs tagged "containers":
+# See current bugs tagged "containers":
 #    https://github.com/tailscale/tailscale/labels/containers
 #
 ############################################################################
@@ -23,11 +17,11 @@
 #
 # To build the Dockerfile:
 #
-#     $ docker build -t tailscale:tailscale .
+#     $ docker build -t tailscale/tailscale .
 #
 # To run the tailscaled agent:
 #
-#     $ docker run -d --name=tailscaled -v /var/lib:/var/lib -v /dev/net/tun:/dev/net/tun --network=host --privileged tailscale:tailscale tailscaled
+#     $ docker run -d --name=tailscaled -v /var/lib:/var/lib -v /dev/net/tun:/dev/net/tun --network=host --privileged tailscale/tailscale tailscaled
 #
 # To then log in:
 #
@@ -38,13 +32,25 @@
 #     $ docker exec tailscaled tailscale status
 
 
-FROM golang:1.16-alpine AS build-env
+FROM golang:1.18-alpine AS build-env
 
 WORKDIR /go/src/tailscale
 
 COPY go.mod go.sum ./
 RUN go mod download
 
+# Pre-build some stuff before the following COPY line invalidates the Docker cache.
+RUN go install \
+    github.com/aws/aws-sdk-go-v2/aws \
+    github.com/aws/aws-sdk-go-v2/config \
+    gvisor.dev/gvisor/pkg/tcpip/adapters/gonet \
+    gvisor.dev/gvisor/pkg/tcpip/stack \
+    golang.org/x/crypto/ssh \
+    golang.org/x/crypto/acme \
+    nhooyr.io/websocket \
+    github.com/mdlayher/netlink \
+    golang.zx2c4.com/wireguard/device
+
 COPY . .
 
 # see build_docker.sh
@@ -54,13 +60,16 @@ ARG VERSION_SHORT=""
 ENV VERSION_SHORT=$VERSION_SHORT
 ARG VERSION_GIT_HASH=""
 ENV VERSION_GIT_HASH=$VERSION_GIT_HASH
+ARG TARGETARCH
 
-RUN go install -tags=xversion -ldflags="\
+RUN GOARCH=$TARGETARCH go install -ldflags="\
       -X tailscale.com/version.Long=$VERSION_LONG \
       -X tailscale.com/version.Short=$VERSION_SHORT \
       -X tailscale.com/version.GitCommit=$VERSION_GIT_HASH" \
-      -v ./cmd/...
+      -v ./cmd/tailscale ./cmd/tailscaled
+
+FROM alpine:3.16
+RUN apk add --no-cache ca-certificates iptables iproute2 ip6tables
 
-FROM alpine:3.11
-RUN apk add --no-cache ca-certificates iptables iproute2
 COPY --from=build-env /go/bin/* /usr/local/bin/
+COPY --from=build-env /go/src/tailscale/docs/k8s/run.sh /usr/local/bin/

Dockerfile.base

@@ -0,0 +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.
+
+FROM alpine:3.16
+RUN apk add --no-cache ca-certificates iptables iproute2 ip6tables

Makefile

@@ -1,24 +1,56 @@
+IMAGE_REPO ?= tailscale/tailscale
+SYNO_ARCH ?= "amd64"
+SYNO_DSM ?= "7"
+
 usage:
 	echo "See Makefile"
 
 vet:
-	go vet ./...
+	./tool/go vet ./...
+
+tidy:
+	./tool/go mod tidy
 
 updatedeps:
-	go run github.com/tailscale/depaware --update tailscale.com/cmd/tailscaled
-	go run github.com/tailscale/depaware --update tailscale.com/cmd/tailscale
+	./tool/go run github.com/tailscale/depaware --update \
+		tailscale.com/cmd/tailscaled \
+		tailscale.com/cmd/tailscale \
+		tailscale.com/cmd/derper
 
 depaware:
-	go run github.com/tailscale/depaware --check tailscale.com/cmd/tailscaled
-	go run github.com/tailscale/depaware --check tailscale.com/cmd/tailscale
+	./tool/go run github.com/tailscale/depaware --check \
+		tailscale.com/cmd/tailscaled \
+		tailscale.com/cmd/tailscale \
+		tailscale.com/cmd/derper
 
 buildwindows:
-	GOOS=windows GOARCH=amd64 go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
+	GOOS=windows GOARCH=amd64 ./tool/go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
 
 build386:
-	GOOS=linux GOARCH=386 go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
+	GOOS=linux GOARCH=386 ./tool/go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
 
-check: staticcheck vet depaware buildwindows build386
+buildlinuxarm:
+	GOOS=linux GOARCH=arm ./tool/go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
+
+buildwasm:
+	GOOS=js GOARCH=wasm ./tool/go install ./cmd/tsconnect/wasm ./cmd/tailscale/cli
+
+buildmultiarchimage:
+	./build_docker.sh
+
+check: staticcheck vet depaware buildwindows build386 buildlinuxarm buildwasm
 
 staticcheck:
-	go run honnef.co/go/tools/cmd/staticcheck -- $$(go list ./... | grep -v tempfork)
+	./tool/go run honnef.co/go/tools/cmd/staticcheck -- $$(./tool/go list ./... | grep -v tempfork)
+
+spk:
+	PATH="${PWD}/tool:${PATH}" ./tool/go run github.com/tailscale/tailscale-synology@main -o tailscale.spk --source=. --goarch=${SYNO_ARCH} --dsm-version=${SYNO_DSM}
+
+spkall:
+	mkdir -p spks
+	PATH="${PWD}/tool:${PATH}" ./tool/go run github.com/tailscale/tailscale-synology@main -o spks --source=. --goarch=all --dsm-version=all
+
+pushspk: spk
+	echo "Pushing SPK to root@${SYNO_HOST} (env var SYNO_HOST) ..."
+	scp tailscale.spk root@${SYNO_HOST}:
+	ssh root@${SYNO_HOST} /usr/syno/bin/synopkg install tailscale.spk

README.md

@@ -8,11 +8,12 @@ Private WireGuard® networks made easy
 
 This repository contains all the open source Tailscale client code and
 the `tailscaled` daemon and `tailscale` CLI tool. The `tailscaled`
-daemon runs primarily on Linux; it also works to varying degrees on
-FreeBSD, OpenBSD, Darwin, and Windows.
+daemon runs on Linux, Windows and [macOS](https://tailscale.com/kb/1065/macos-variants/), and to varying degrees on FreeBSD, OpenBSD, and Darwin. (The Tailscale iOS and Android apps use this repo's code, but this repo doesn't contain the mobile GUI code.)
 
 The Android app is at https://github.com/tailscale/tailscale-android
 
+The Synology package is at https://github.com/tailscale/tailscale-synology
+
 ## Using
 
 We serve packages for a variety of distros at
@@ -42,10 +43,7 @@ If your distro has conventions that preclude the use of
 `build_dist.sh`, please do the equivalent of what it does in your
 distro's way, so that bug reports contain useful version information.
 
-We only guarantee to support the latest Go release and any Go beta or
-release candidate builds (currently Go 1.16) in module mode. It might
-work in earlier Go versions or in GOPATH mode, but we're making no
-effort to keep those working.
+We require the latest Go release, currently Go 1.19.
 
 ## Bugs
 

VERSION.txt

@@ -1 +1 @@
-1.13.0
+1.31.0

api.md

@@ -3,7 +3,7 @@
 The Tailscale API is a (mostly) RESTful API. Typically, POST bodies should be JSON encoded and responses will be JSON encoded.
 
 # Authentication
-Currently based on {some authentication method}. Visit the [admin panel](https://api.tailscale.com/admin) and navigate to the `Keys` page. Generate an API Key and keep it safe. Provide the key as the user key in basic auth when making calls to Tailscale API endpoints.
+Currently based on {some authentication method}. Visit the [admin panel](https://login.tailscale.com/admin) and navigate to the `Settings` page. Generate an API Key and keep it safe. Provide the key as the user key in basic auth when making calls to Tailscale API endpoints (leave the password blank).
 
 # APIs
 
@@ -13,13 +13,25 @@ Currently based on {some authentication method}. Visit the [admin panel](https:/
   - Routes
     - [GET device routes](#device-routes-get)
     - [POST device routes](#device-routes-post)
+  - Authorize machine
+    - [POST device authorized](#device-authorized-post)
+  - Tags
+    - [POST device tags](#device-tags-post)
+  - Key
+    - [POST device key](#device-key-post)
 * **[Tailnets](#tailnet)**
   - ACLs
     - [GET tailnet ACL](#tailnet-acl-get)
-    - [POST tailnet ACL](#tailnet-acl-post): set ACL for a tailnet
-    - [POST tailnet ACL preview](#tailnet-acl-preview-post): preview rule matches on an ACL for a resource
+    - [POST tailnet ACL](#tailnet-acl-post)
+    - [POST tailnet ACL preview](#tailnet-acl-preview-post)
+	- [POST tailnet ACL validate](#tailnet-acl-validate-post)
   - [Devices](#tailnet-devices)
     - [GET tailnet devices](#tailnet-devices-get)
+  - [Keys](#tailnet-keys)
+    - [GET tailnet keys](#tailnet-keys-get)
+    - [POST tailnet key](#tailnet-keys-post)
+    - [GET tailnet key](#tailnet-keys-key-get)
+    - [DELETE tailnet key](#tailnet-keys-key-delete)
   - [DNS](#tailnet-dns)
     - [GET tailnet DNS nameservers](#tailnet-dns-nameservers-get)
     - [POST tailnet DNS nameservers](#tailnet-dns-nameservers-post)
@@ -30,14 +42,14 @@ Currently based on {some authentication method}. Visit the [admin panel](https:/
 
 ## Device
 <!-- TODO: description about what devices are -->
-Each Tailscale-connected device has a globally-unique identifier number which we refer as the "deviceID" or sometimes, just "id". 
+Each Tailscale-connected device has a globally-unique identifier number which we refer as the "deviceID" or sometimes, just "id".
 You can use the deviceID to specify operations on a specific device, like retrieving its subnet routes.
 
-To find the deviceID of a particular device, you can use the ["GET /devices"](#getdevices) API call and generate a list of devices on your network. 
+To find the deviceID of a particular device, you can use the ["GET /devices"](#getdevices) API call and generate a list of devices on your network.
 Find the device you're looking for and get the "id" field.
-This is your deviceID. 
+This is your deviceID.
 
-<a name=device-get></div>
+<a name=device-get></a>
 
 #### `GET /api/v2/device/:deviceid` - lists the details for a device
 Returns the details for the specified device.
@@ -48,7 +60,7 @@ Use the `fields` query parameter to explicitly indicate which fields are returne
 ##### Parameters
 ##### Query Parameters
 `fields` - Controls which fields will be included in the returned response.
-Currently, supported options are: 
+Currently, supported options are:
 * `all`: returns all fields in the response.
 * `default`: return all fields except:
   * `enabledRoutes`
@@ -60,7 +72,7 @@ If more than one option is indicated, then the union is used.
 For example, for `fields=default,all`, all fields are returned.
 If the `fields` parameter is not provided, then the default option is used.
 
-##### Example 
+##### Example
 ```
 GET /api/v2/device/12345
 curl 'https://api.tailscale.com/api/v2/device/12345?fields=all' \
@@ -90,10 +102,10 @@ Response
   "nodeKey":"nodekey:user1-node-key",
   "blocksIncomingConnections":false,
   "enabledRoutes":[
-    
+
   ],
   "advertisedRoutes":[
-    
+
   ],
   "clientConnectivity": {
     "endpoints":[
@@ -126,10 +138,10 @@ Response
 }
 ```
 
-<a name=device-delete></div>
+<a name=device-delete></a>
 
 #### `DELETE /api/v2/device/:deviceID` - deletes the device from its tailnet
-Deletes the provided device from its tailnet. 
+Deletes the provided device from its tailnet.
 The device must belong to the user's tailnet.
 Deleting shared/external devices is not supported.
 Supply the device of interest in the path using its ID.
@@ -147,7 +159,7 @@ curl -X DELETE 'https://api.tailscale.com/api/v2/device/12345' \
 
 Response
 
-If successful, the response should be empty: 
+If successful, the response should be empty:
 ```
 < HTTP/1.1 200 OK
 ...
@@ -155,7 +167,7 @@ If successful, the response should be empty:
 * Closing connection 0
 ```
 
-If the device is not owned by your tailnet: 
+If the device is not owned by your tailnet:
 ```
 < HTTP/1.1 501 Not Implemented
 ...
@@ -163,7 +175,7 @@ If the device is not owned by your tailnet:
 ```
 
 
-<a name=device-routes-get></div>
+<a name=device-routes-get></a>
 
 #### `GET /api/v2/device/:deviceID/routes` - fetch subnet routes that are advertised and enabled for a device
 
@@ -192,7 +204,7 @@ Response
 }
 ```
 
-<a name=device-routes-post></div>
+<a name=device-routes-post></a>
 
 #### `POST /api/v2/device/:deviceID/routes` - set the subnet routes that are enabled for a device
 
@@ -233,8 +245,97 @@ Response
 }
 ```
 
-## Tailnet 
-A tailnet is the name of your Tailscale network. 
+<a name=device-authorized-post></a>
+
+#### `POST /api/v2/device/:deviceID/authorized` - authorize a device
+
+Marks a device as authorized, for Tailnets where device authorization is required.
+
+##### Parameters
+
+###### POST Body
+`authorized` - whether the device is authorized; only `true` is currently supported.
+```
+{
+  "authorized": true
+}
+```
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/device/11055/authorized' \
+-u "tskey-yourapikey123:" \
+--data-binary '{"authorized": true}'
+```
+
+The response is 2xx on success. The response body is currently an empty JSON
+object.
+
+<a name=device-tags-post></a>
+
+#### `POST /api/v2/device/:deviceID/tags` - update tags on a device
+
+Updates the tags set on a device.
+
+##### Parameters
+
+###### POST Body
+
+`tags` - The new list of tags for the device.
+
+```
+{
+  "tags": ["tag:foo", "tag:bar"]
+}
+```
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/device/11055/tags' \
+-u "tskey-yourapikey123:" \
+--data-binary '{"tags": ["tag:foo", "tag:bar"]}'
+```
+
+The response is 2xx on success. The response body is currently an empty JSON
+object.
+
+<a name=device-key-post></a>
+
+#### `POST /api/v2/device/:deviceID/key` - update device key
+
+Allows for updating properties on the device key.
+
+##### Parameters
+
+###### POST Body
+
+`keyExpiryDisabled`
+
+- Provide `true` to disable the device's key expiry. The original key expiry time is still maintained. Upon re-enabling, the key will expire at that original time.
+- Provide `false` to enable the device's key expiry. Sets the key to expire at the original expiry time prior to disabling. The key may already have expired. In that case, the device must be re-authenticated.
+- Empty value will not change the key expiry.
+
+```
+{
+  "keyExpiryDisabled": true
+}
+```
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/device/11055/key' \
+-u "tskey-yourapikey123:" \
+--data-binary '{"keyExpiryDisabled": true}'
+```
+
+The response is 2xx on success. The response body is currently an empty JSON
+object.
+
+## Tailnet
+A tailnet is the name of your Tailscale network.
 You can find it in the top left corner of the [Admin Panel](https://login.tailscale.com/admin) beside the Tailscale logo.
 
 
@@ -473,7 +574,7 @@ Determines what rules match for a user on an ACL without saving the ACL to the s
 ###### 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 paramater to determine which rules match.
+The provided ACL is queried with this parameter to determine which rules match.
 
 ###### POST Body
 ACL JSON or HuJSON (see https://tailscale.com/kb/1018/acls)
@@ -510,6 +611,72 @@ 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
+
+This endpoint works in one of two modes:
+
+1. with a request body that's a JSON array, the body is interpreted as ACL tests to run against the domain's current ACLs.
+2. with a request body that's a JSON object, the body is interpreted as a hypothetical new JSON (HuJSON) body with new ACLs, including any tests.
+
+In either case, 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 with tests
+```
+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"]}
+  ]'
+```
+
+##### Example with an ACL body
+```
+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 '
+  {
+    "ACLs": [
+     { "Action": "accept", "src": ["100.105.106.107"], "dst": ["1.2.3.4:*"] },
+    ],
+    "Tests", [
+      {"src": "100.105.106.107", "allow": ["1.2.3.4:80"]}
+    ],
+  }'
+```
+
+Response:
+
+The HTTP status code will be 200 if the request was well formed and there were no server errors, even in the case of failing tests or an invalid ACL. Look at the response body to determine whether there was a problem within your ACL or tests.
+
+If there's a problem, the response body will be a JSON object with a non-empty `message` property and optionally additional details in `data`:
+
+```
+{
+  "message":"test(s) failed",
+  "data":[
+           {
+             "user":"user1@example.com",
+             "errors":["address \"2.2.2.2:22\": want: Drop, got: Accept"]
+           }
+         ]
+}
+```
+
+An empty body or a JSON object with no `message` is returned on success.
+
 <a name=tailnet-devices></a>
 
 ### Devices
@@ -517,7 +684,7 @@ Response:
 <a name=tailnet-devices-get></a>
 
 #### <a name="getdevices"></a> `GET /api/v2/tailnet/:tailnet/devices` - list the devices for a tailnet
-Lists the devices in a tailnet. 
+Lists the devices in a tailnet.
 Supply the tailnet of interest in the path.
 Use the `fields` query parameter to explicitly indicate which fields are returned.
 
@@ -526,7 +693,7 @@ Use the `fields` query parameter to explicitly indicate which fields are returne
 
 ###### Query Parameters
 `fields` - Controls which fields will be included in the returned response.
-Currently, supported options are: 
+Currently, supported options are:
 * `all`: Returns all fields in the response.
 * `default`: return all fields except:
   * `enabledRoutes`
@@ -546,7 +713,7 @@ curl 'https://api.tailscale.com/api/v2/tailnet/example.com/devices' \
   -u "tskey-yourapikey123:"
 ```
 
-Response 
+Response
 ```
 {
   "devices":[
@@ -596,6 +763,177 @@ Response
 }
 ```
 
+<a name=tailnet-keys></a>
+
+### Keys
+
+<a name=tailnet-keys-get></a>
+
+#### `GET /api/v2/tailnet/:tailnet/keys` - list the keys for a tailnet
+
+Returns a list of active keys for a tailnet
+for the user who owns the API key used to perform this query.
+Supply the tailnet of interest in the path.
+
+##### Parameters
+No parameters.
+
+##### Returns
+
+Returns a JSON object with the IDs of all active keys.
+This includes both API keys and also machine authentication keys.
+In the future, this may provide more information about each key than just the ID.
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/keys' \
+  -u "tskey-yourapikey123:"
+```
+
+Response:
+```
+{"keys": [
+	{"id": "kYKVU14CNTRL"},
+	{"id": "k68VdZ3CNTRL"},
+	{"id": "kJ9nq43CNTRL"},
+	{"id": "kkThgj1CNTRL"}
+]}
+```
+
+<a name=tailnet-keys-post></a>
+
+#### `POST /api/v2/tailnet/:tailnet/keys` - create a new key for a tailnet
+
+Create a new key in a tailnet associated
+with the user who owns the API key used to perform this request.
+Supply the tailnet in the path.
+
+##### Parameters
+
+###### POST Body
+`capabilities` - A mapping of resources to permissible actions.
+```
+{
+  "capabilities": {
+    "devices": {
+      "create": {
+        "reusable": false,
+        "ephemeral": false,
+        "preauthorized": false,
+        "tags": [
+          "tag:example"
+        ]
+      }
+    }
+  }
+}
+```
+
+##### Returns
+
+Returns a JSON object with the provided capabilities in addition to the
+generated key. The key should be recorded and kept safe and secure as it
+wields the capabilities specified in the request. The identity of the key
+is embedded in the key itself and can be used to perform operations on
+the key (e.g., revoking it or retrieving information about it).
+The full key can no longer be retrieved by the server.
+
+##### Example
+
+```
+echo '{
+  "capabilities": {
+    "devices": {
+      "create": {
+        "reusable": false,
+        "ephemeral": false,
+        "preauthorized": false,
+        "tags": [ "tag:example" ]
+      }
+    }
+  }
+}' | curl -X POST --data-binary @- https://api.tailscale.com/api/v2/tailnet/example.com/keys \
+  -u "tskey-yourapikey123:" \
+  -H "Content-Type: application/json" | jsonfmt
+```
+
+Response:
+```
+{
+	"id":           "k123456CNTRL",
+	"key":          "tskey-k123456CNTRL-abcdefghijklmnopqrstuvwxyz",
+	"created":      "2021-12-09T23:22:39Z",
+	"expires":      "2022-03-09T23:22:39Z",
+	"capabilities": {"devices": {"create": {"reusable": false, "ephemeral": false, "preauthorized": false, "tags": [ "tag:example" ]}}}
+}
+```
+
+<a name=tailnet-keys-key-get></a>
+
+#### `GET /api/v2/tailnet/:tailnet/keys/:keyid` - get information for a specific key
+
+Returns a JSON object with information about specific key.
+Supply the tailnet and key ID of interest in the path.
+
+##### Parameters
+No parameters.
+
+##### Returns
+
+Returns a JSON object with information about the key such as
+when it was created and when it expires.
+It also lists the capabilities associated with the key.
+
+##### Example
+
+```
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/keys/k123456CNTRL' \
+  -u "tskey-yourapikey123:"
+```
+
+Response:
+```
+{
+  "id": "k123456CNTRL",
+  "created": "2022-05-05T18:55:44Z",
+  "expires": "2022-08-03T18:55:44Z",
+  "capabilities": {
+    "devices": {
+      "create": {
+        "reusable": false,
+        "ephemeral": true,
+        "preauthorized": false,
+        "tags": [
+          "tag:bar",
+          "tag:foo"
+        ]
+      }
+    }
+  }
+}
+```
+
+<a name=tailnet-keys-key-delete></a>
+
+#### `DELETE /api/v2/tailnet/:tailnet/keys/:keyid` - delete a specific key
+
+Deletes a specific key.
+Supply the tailnet and key ID of interest in the path.
+
+##### Parameters
+No parameters.
+
+##### Returns
+This reports status 200 upon success.
+
+##### Example
+
+```
+curl -X DELETE 'https://api.tailscale.com/api/v2/tailnet/example.com/keys/k123456CNTRL' \
+  -u "tskey-yourapikey123:"
+```
+
 <a name=tailnet-dns></a>
 
 ### DNS
@@ -603,13 +941,13 @@ Response
 <a name=tailnet-dns-nameservers-get></a>
 
 #### `GET /api/v2/tailnet/:tailnet/dns/nameservers` - list the DNS nameservers for a tailnet
-Lists the DNS nameservers for a tailnet. 
+Lists the DNS nameservers for a tailnet.
 Supply the tailnet of interest in the path.
 
 ##### Parameters
 No parameters.
 
-##### Example 
+##### Example
 
 ```
 GET /api/v2/tailnet/example.com/dns/nameservers
@@ -617,7 +955,7 @@ curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/nameservers' \
   -u "tskey-yourapikey123:"
 ```
 
-Response 
+Response
 ```
 {
   "dns": ["8.8.8.8"],
@@ -627,7 +965,7 @@ Response
 <a name=tailnet-dns-nameservers-post></a>
 
 #### `POST /api/v2/tailnet/:tailnet/dns/nameservers` - replaces the list of DNS nameservers for a tailnet
-Replaces the list of DNS nameservers for the given tailnet with the list supplied by the user. 
+Replaces the list of DNS nameservers for the given tailnet with the list supplied by the user.
 Supply the tailnet of interest in the path.
 Note that changing the list of DNS nameservers may also affect the status of MagicDNS (if MagicDNS is on).
 
@@ -641,7 +979,7 @@ Note that changing the list of DNS nameservers may also affect the status of Mag
 ```
 
 ##### Returns
-Returns the new list of nameservers and the status of MagicDNS. 
+Returns the new list of nameservers and the status of MagicDNS.
 
 If all nameservers have been removed, MagicDNS will be automatically disabled (until explicitly turned back on by the user).
 
@@ -685,31 +1023,31 @@ Retrieves the DNS preferences that are currently set for the given tailnet.
 Supply the tailnet of interest in the path.
 
 ##### Parameters
-No parameters. 
+No parameters.
 
 ##### Example
 ```
 GET /api/v2/tailnet/example.com/dns/preferences
 curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/preferences' \
-  -u "tskey-yourapikey123:" 
+  -u "tskey-yourapikey123:"
 ```
 
 Response:
 ```
 {
-  "magicDNS":false, 
+  "magicDNS":false,
 }
 ```
 
 <a name=tailnet-dns-preferences-post></a>
 
-#### `POST /api/v2/tailnet/:tailnet/dns/preferences` - replaces the DNS preferences for a tailnet 
+#### `POST /api/v2/tailnet/:tailnet/dns/preferences` - replaces the DNS preferences for a tailnet
 Replaces the DNS preferences for a tailnet, specifically, the MagicDNS setting.
-Note that MagicDNS is dependent on DNS servers. 
+Note that MagicDNS is dependent on DNS servers.
 
-If there is at least one DNS server, then MagicDNS can be enabled. 
+If there is at least one DNS server, then MagicDNS can be enabled.
 Otherwise, it returns an error.
-Note that removing all nameservers will turn off MagicDNS. 
+Note that removing all nameservers will turn off MagicDNS.
 To reenable it, nameservers must be added back, and MagicDNS must be explicitly turned on.
 
 ##### Parameters
@@ -740,7 +1078,7 @@ If there are no DNS servers, it returns an error message:
 }
 ```
 
-If there are DNS servers: 
+If there are DNS servers:
 ```
 {
   "magicDNS":true,
@@ -749,8 +1087,8 @@ If there are DNS servers:
 
 <a name=tailnet-dns-searchpaths-get></a>
 
-#### `GET /api/v2/tailnet/:tailnet/dns/searchpaths` - retrieves the search paths for a tailnet 
-Retrieves the list of search paths that is currently set for the given tailnet. 
+#### `GET /api/v2/tailnet/:tailnet/dns/searchpaths` - retrieves the search paths for a tailnet
+Retrieves the list of search paths that is currently set for the given tailnet.
 Supply the tailnet of interest in the path.
 
 
@@ -761,7 +1099,7 @@ No parameters.
 ```
 GET /api/v2/tailnet/example.com/dns/searchpaths
 curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/searchpaths' \
-  -u "tskey-yourapikey123:" 
+  -u "tskey-yourapikey123:"
 ```
 
 Response:
@@ -773,7 +1111,7 @@ Response:
 
 <a name=tailnet-dns-searchpaths-post></a>
 
-#### `POST /api/v2/tailnet/:tailnet/dns/searchpaths` - replaces the search paths for a tailnet 
+#### `POST /api/v2/tailnet/:tailnet/dns/searchpaths` - replaces the search paths for a tailnet
 Replaces the list of searchpaths with the list supplied by the user and returns an error otherwise.
 
 ##### Parameters
@@ -782,7 +1120,7 @@ Replaces the list of searchpaths with the list supplied by the user and returns
 `searchPaths` - A list of searchpaths in JSON.
 ```
 {
-  "searchPaths: ["user1.example.com", "user2.example.com"]
+  "searchPaths": ["user1.example.com", "user2.example.com"]
 }
 ```
 

atomicfile/atomicfile.go

@@ -16,7 +16,7 @@ import (
 )
 
 // WriteFile writes data to filename+some suffix, then renames it
-// into filename.
+// into filename. The perm argument is ignored on Windows.
 func WriteFile(filename string, data []byte, perm os.FileMode) (err error) {
 	f, err := ioutil.TempFile(filepath.Dir(filename), filepath.Base(filename)+".tmp")
 	if err != nil {

build_dist.sh

@@ -30,12 +30,14 @@ else
 fi
 
 long_suffix="$change_suffix-t$short_hash"
-SHORT="$major.$minor.$patch"
+MINOR="$major.$minor"
+SHORT="$MINOR.$patch"
 LONG="${SHORT}$long_suffix"
 GIT_HASH="$git_hash"
 
 if [ "$1" = "shellvars" ]; then
 	cat <<EOF
+VERSION_MINOR="$MINOR"
 VERSION_SHORT="$SHORT"
 VERSION_LONG="$LONG"
 VERSION_GIT_HASH="$GIT_HASH"
@@ -43,4 +45,25 @@ 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=${GIT_HASH}" "$@"
+tags=""
+ldflags="-X tailscale.com/version.Long=${LONG} -X tailscale.com/version.Short=${SHORT} -X tailscale.com/version.GitCommit=${GIT_HASH}"
+
+# build_dist.sh arguments must precede go build arguments.
+while [ "$#" -gt 1 ]; do
+	case "$1" in
+	--extra-small)
+		shift
+		ldflags="$ldflags -w -s"
+		tags="${tags:+$tags,}ts_omit_aws"
+		;;
+	--box)
+		shift
+		tags="${tags:+$tags,}ts_include_cli"
+		;;
+	*)
+		break
+		;;
+	esac
+done
+
+exec ./tool/go build ${tags:+-tags=$tags} -ldflags "$ldflags" "$@"

build_docker.sh

@@ -8,27 +8,41 @@
 #
 ############################################################################
 #
-# WARNING: Tailscale is not yet officially supported in Docker,
-# Kubernetes, etc.
+# WARNING: Tailscale is not yet officially supported in container
+# environments, such as Docker and Kubernetes. Though it should work, we
+# don't regularly test it, and we know there are some feature limitations.
 #
-# It might work, but we don't regularly test it, and it's not as polished as
-# our currently supported platforms. This is provided for people who know
-# how Tailscale works and what they're doing.
-#
-# Our tracking bug for officially support container use cases is:
-#    https://github.com/tailscale/tailscale/issues/504
-#
-# Also, see the various bugs tagged "containers":
+# See current bugs tagged "containers":
 #    https://github.com/tailscale/tailscale/labels/containers
 #
 ############################################################################
 
 set -eu
 
-eval $(./build_dist.sh shellvars)
+# Use the "go" binary from the "tool" directory (which is github.com/tailscale/go)
+export PATH=$PWD/tool:$PATH
 
-docker build \
-  --build-arg VERSION_LONG=$VERSION_LONG \
-  --build-arg VERSION_SHORT=$VERSION_SHORT \
-  --build-arg VERSION_GIT_HASH=$VERSION_GIT_HASH \
-  -t tailscale:tailscale .
+eval $(./build_dist.sh shellvars)
+DEFAULT_TAGS="v${VERSION_SHORT},v${VERSION_MINOR}"
+DEFAULT_REPOS="tailscale/tailscale,ghcr.io/tailscale/tailscale"
+DEFAULT_BASE="ghcr.io/tailscale/alpine-base:3.16"
+
+PUSH="${PUSH:-false}"
+REPOS="${REPOS:-${DEFAULT_REPOS}}"
+TAGS="${TAGS:-${DEFAULT_TAGS}}"
+BASE="${BASE:-${DEFAULT_BASE}}"
+
+go run github.com/tailscale/mkctr \
+  --gopaths="\
+    tailscale.com/cmd/tailscale:/usr/local/bin/tailscale, \
+    tailscale.com/cmd/tailscaled:/usr/local/bin/tailscaled" \
+  --ldflags="\
+    -X tailscale.com/version.Long=${VERSION_LONG} \
+    -X tailscale.com/version.Short=${VERSION_SHORT} \
+    -X tailscale.com/version.GitCommit=${VERSION_GIT_HASH}" \
+  --files="docs/k8s/run.sh:/tailscale/run.sh" \
+  --base="${BASE}" \
+  --tags="${TAGS}" \
+  --repos="${REPOS}" \
+  --push="${PUSH}" \
+  /bin/sh /tailscale/run.sh

chirp/chirp.go

@@ -0,0 +1,158 @@
+// 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 chirp implements a client to communicate with the BIRD Internet
+// Routing Daemon.
+package chirp
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"strings"
+	"time"
+)
+
+const (
+	// Maximum amount of time we should wait when reading a response from BIRD.
+	responseTimeout = 10 * time.Second
+)
+
+// New creates a BIRDClient.
+func New(socket string) (*BIRDClient, error) {
+	return newWithTimeout(socket, responseTimeout)
+}
+
+func newWithTimeout(socket string, timeout time.Duration) (*BIRDClient, error) {
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to BIRD: %w", err)
+	}
+	b := &BIRDClient{
+		socket:  socket,
+		conn:    conn,
+		scanner: bufio.NewScanner(conn),
+		timeNow: time.Now,
+		timeout: timeout,
+	}
+	// Read and discard the first line as that is the welcome message.
+	if _, err := b.readResponse(); err != nil {
+		return nil, err
+	}
+	return b, nil
+}
+
+// BIRDClient handles communication with the BIRD Internet Routing Daemon.
+type BIRDClient struct {
+	socket  string
+	conn    net.Conn
+	scanner *bufio.Scanner
+	timeNow func() time.Time
+	timeout time.Duration
+}
+
+// Close closes the underlying connection to BIRD.
+func (b *BIRDClient) Close() error { return b.conn.Close() }
+
+// DisableProtocol disables the provided protocol.
+func (b *BIRDClient) DisableProtocol(protocol string) error {
+	out, err := b.exec("disable %s", protocol)
+	if err != nil {
+		return err
+	}
+	if strings.Contains(out, fmt.Sprintf("%s: already disabled", protocol)) {
+		return nil
+	} else if strings.Contains(out, fmt.Sprintf("%s: disabled", protocol)) {
+		return nil
+	}
+	return fmt.Errorf("failed to disable %s: %v", protocol, out)
+}
+
+// EnableProtocol enables the provided protocol.
+func (b *BIRDClient) EnableProtocol(protocol string) error {
+	out, err := b.exec("enable %s", protocol)
+	if err != nil {
+		return err
+	}
+	if strings.Contains(out, fmt.Sprintf("%s: already enabled", protocol)) {
+		return nil
+	} else if strings.Contains(out, fmt.Sprintf("%s: enabled", protocol)) {
+		return nil
+	}
+	return fmt.Errorf("failed to enable %s: %v", protocol, out)
+}
+
+// BIRD CLI docs from https://bird.network.cz/?get_doc&v=20&f=prog-2.html#ss2.9
+
+// Each session of the CLI consists of a sequence of request and replies,
+// slightly resembling the FTP and SMTP protocols.
+// Requests are commands encoded as a single line of text,
+// replies are sequences of lines starting with a four-digit code
+// followed by either a space (if it's the last line of the reply) or
+// a minus sign (when the reply is going to continue with the next line),
+// the rest of the line contains a textual message semantics of which depends on the numeric code.
+// If a reply line has the same code as the previous one and it's a continuation line,
+// the whole prefix can be replaced by a single white space character.
+//
+// Reply codes starting with 0 stand for ‘action successfully completed’ messages,
+// 1 means ‘table entry’, 8 ‘runtime error’ and 9 ‘syntax error’.
+
+func (b *BIRDClient) exec(cmd string, args ...any) (string, error) {
+	if err := b.conn.SetWriteDeadline(b.timeNow().Add(b.timeout)); err != nil {
+		return "", err
+	}
+	if _, err := fmt.Fprintf(b.conn, cmd, args...); err != nil {
+		return "", err
+	}
+	if _, err := fmt.Fprintln(b.conn); err != nil {
+		return "", err
+	}
+	return b.readResponse()
+}
+
+// hasResponseCode reports whether the provided byte slice is
+// prefixed with a BIRD response code.
+// Equivalent regex: `^\d{4}[ -]`.
+func hasResponseCode(s []byte) bool {
+	if len(s) < 5 {
+		return false
+	}
+	for _, b := range s[:4] {
+		if '0' <= b && b <= '9' {
+			continue
+		}
+		return false
+	}
+	return s[4] == ' ' || s[4] == '-'
+}
+
+func (b *BIRDClient) readResponse() (string, error) {
+	// Set the read timeout before we start reading anything.
+	if err := b.conn.SetReadDeadline(b.timeNow().Add(b.timeout)); err != nil {
+		return "", err
+	}
+
+	var resp strings.Builder
+	var done bool
+	for !done {
+		if !b.scanner.Scan() {
+			if err := b.scanner.Err(); err != nil {
+				return "", err
+			}
+
+			return "", fmt.Errorf("reading response from bird failed (EOF): %q", resp.String())
+		}
+		out := b.scanner.Bytes()
+		if _, err := resp.Write(out); err != nil {
+			return "", err
+		}
+		if hasResponseCode(out) {
+			done = out[4] == ' '
+		}
+		if !done {
+			resp.WriteRune('\n')
+		}
+	}
+	return resp.String(), nil
+}

chirp/chirp_test.go

@@ -0,0 +1,193 @@
+// Copyright (c) 2022 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 chirp
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+type fakeBIRD struct {
+	net.Listener
+	protocolsEnabled map[string]bool
+	sock             string
+}
+
+func newFakeBIRD(t *testing.T, protocols ...string) *fakeBIRD {
+	sock := filepath.Join(t.TempDir(), "sock")
+	l, err := net.Listen("unix", sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pe := make(map[string]bool)
+	for _, p := range protocols {
+		pe[p] = false
+	}
+	return &fakeBIRD{
+		Listener:         l,
+		protocolsEnabled: pe,
+		sock:             sock,
+	}
+}
+
+func (fb *fakeBIRD) listen() error {
+	for {
+		c, err := fb.Accept()
+		if err != nil {
+			if errors.Is(err, net.ErrClosed) {
+				return nil
+			}
+			return err
+		}
+		go fb.handle(c)
+	}
+}
+
+func (fb *fakeBIRD) handle(c net.Conn) {
+	fmt.Fprintln(c, "0001 BIRD 2.0.8 ready.")
+	sc := bufio.NewScanner(c)
+	for sc.Scan() {
+		cmd := sc.Text()
+		args := strings.Split(cmd, " ")
+		switch args[0] {
+		case "enable":
+			en, ok := fb.protocolsEnabled[args[1]]
+			if !ok {
+				fmt.Fprintln(c, "9001 syntax error, unexpected CF_SYM_UNDEFINED, expecting CF_SYM_KNOWN or TEXT or ALL")
+			} else if en {
+				fmt.Fprintf(c, "0010-%s: already enabled\n", args[1])
+			} else {
+				fmt.Fprintf(c, "0011-%s: enabled\n", args[1])
+			}
+			fmt.Fprintln(c, "0000 ")
+			fb.protocolsEnabled[args[1]] = true
+		case "disable":
+			en, ok := fb.protocolsEnabled[args[1]]
+			if !ok {
+				fmt.Fprintln(c, "9001 syntax error, unexpected CF_SYM_UNDEFINED, expecting CF_SYM_KNOWN or TEXT or ALL")
+			} else if !en {
+				fmt.Fprintf(c, "0008-%s: already disabled\n", args[1])
+			} else {
+				fmt.Fprintf(c, "0009-%s: disabled\n", args[1])
+			}
+			fmt.Fprintln(c, "0000 ")
+			fb.protocolsEnabled[args[1]] = false
+		}
+	}
+}
+
+func TestChirp(t *testing.T) {
+	fb := newFakeBIRD(t, "tailscale")
+	defer fb.Close()
+	go fb.listen()
+	c, err := New(fb.sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := c.EnableProtocol("tailscale"); err != nil {
+		t.Fatal(err)
+	}
+	if err := c.EnableProtocol("tailscale"); err != nil {
+		t.Fatal(err)
+	}
+	if err := c.DisableProtocol("tailscale"); err != nil {
+		t.Fatal(err)
+	}
+	if err := c.DisableProtocol("tailscale"); err != nil {
+		t.Fatal(err)
+	}
+	if err := c.EnableProtocol("rando"); err == nil {
+		t.Fatalf("enabling %q succeded", "rando")
+	}
+	if err := c.DisableProtocol("rando"); err == nil {
+		t.Fatalf("disabling %q succeded", "rando")
+	}
+}
+
+type hangingListener struct {
+	net.Listener
+	t    *testing.T
+	done chan struct{}
+	wg   sync.WaitGroup
+	sock string
+}
+
+func newHangingListener(t *testing.T) *hangingListener {
+	sock := filepath.Join(t.TempDir(), "sock")
+	l, err := net.Listen("unix", sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return &hangingListener{
+		Listener: l,
+		t:        t,
+		done:     make(chan struct{}),
+		sock:     sock,
+	}
+}
+
+func (hl *hangingListener) Stop() {
+	hl.Close()
+	close(hl.done)
+	hl.wg.Wait()
+}
+
+func (hl *hangingListener) listen() error {
+	for {
+		c, err := hl.Accept()
+		if err != nil {
+			if errors.Is(err, net.ErrClosed) {
+				return nil
+			}
+			return err
+		}
+		hl.wg.Add(1)
+		go hl.handle(c)
+	}
+}
+
+func (hl *hangingListener) handle(c net.Conn) {
+	defer hl.wg.Done()
+
+	// Write our fake first line of response so that we get into the read loop
+	fmt.Fprintln(c, "0001 BIRD 2.0.8 ready.")
+
+	ticker := time.NewTicker(2 * time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			hl.t.Logf("connection still hanging")
+		case <-hl.done:
+			return
+		}
+	}
+}
+
+func TestChirpTimeout(t *testing.T) {
+	fb := newHangingListener(t)
+	defer fb.Stop()
+	go fb.listen()
+
+	c, err := newWithTimeout(fb.sock, 500*time.Millisecond)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = c.EnableProtocol("tailscale")
+	if err == nil {
+		t.Fatal("got err=nil, want timeout")
+	}
+	if !os.IsTimeout(err) {
+		t.Fatalf("got err=%v, want os.IsTimeout(err)=true", err)
+	}
+}

client/tailscale/acl.go

@@ -0,0 +1,477 @@
+// Copyright (c) 2022 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 go1.19
+// +build go1.19
+
+package tailscale
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/netip"
+)
+
+// ACLRow defines a rule that grants access by a set of users or groups to a set
+// of servers and ports.
+// Only one of Src/Dst or Users/Ports may be specified.
+type ACLRow struct {
+	Action string   `json:"action,omitempty"` // valid values: "accept"
+	Users  []string `json:"users,omitempty"`  // old name for src
+	Ports  []string `json:"ports,omitempty"`  // old name for dst
+	Src    []string `json:"src,omitempty"`
+	Dst    []string `json:"dst,omitempty"`
+}
+
+// ACLTest defines a test for your ACLs to prevent accidental exposure or
+// revoking of access to key servers and ports. Only one of Src or User may be
+// specified, and only one of Allow/Accept may be specified.
+type ACLTest struct {
+	Src    string   `json:"src,omitempty"`    // source
+	User   string   `json:"user,omitempty"`   // old name for source
+	Accept []string `json:"accept,omitempty"` // expected destination ip:port that user can access
+	Deny   []string `json:"deny,omitempty"`   // expected destination ip:port that user cannot access
+
+	Allow []string `json:"allow,omitempty"` // old name for accept
+}
+
+// ACLDetails contains all the details for an ACL.
+type ACLDetails struct {
+	Tests     []ACLTest           `json:"tests,omitempty"`
+	ACLs      []ACLRow            `json:"acls,omitempty"`
+	Groups    map[string][]string `json:"groups,omitempty"`
+	TagOwners map[string][]string `json:"tagowners,omitempty"`
+	Hosts     map[string]string   `json:"hosts,omitempty"`
+}
+
+// ACL contains an ACLDetails and metadata.
+type ACL struct {
+	ACL  ACLDetails
+	ETag string // to check with version on server
+}
+
+// ACLHuJSON contains the HuJSON string of the ACL and metadata.
+type ACLHuJSON struct {
+	ACL      string
+	Warnings []string
+	ETag     string // to check with version on server
+}
+
+// ACL makes a call to the Tailscale server to get a JSON-parsed version of the ACL.
+// The JSON-parsed version of the ACL contains no comments as proper JSON does not support
+// comments.
+func (c *Client) ACL(ctx context.Context) (acl *ACL, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.ACL: %w", err)
+		}
+	}()
+
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/acl", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Accept", "application/json")
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	// Otherwise, try to decode the response.
+	var aclDetails ACLDetails
+	if err = json.Unmarshal(b, &aclDetails); err != nil {
+		return nil, err
+	}
+	acl = &ACL{
+		ACL:  aclDetails,
+		ETag: resp.Header.Get("ETag"),
+	}
+	return acl, nil
+}
+
+// ACLHuJSON makes a call to the Tailscale server to get the ACL HuJSON and returns
+// it as a string.
+// HuJSON is JSON with a few modifications to make it more human-friendly. The primary
+// changes are allowing comments and trailing comments. See the following links for more info:
+// https://tailscale.com/kb/1018/acls?q=acl#tailscale-acl-policy-format
+// https://github.com/tailscale/hujson
+func (c *Client) ACLHuJSON(ctx context.Context) (acl *ACLHuJSON, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.ACLHuJSON: %w", err)
+		}
+	}()
+
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/acl?details=1", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Accept", "application/hujson")
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	data := struct {
+		ACL      []byte   `json:"acl"`
+		Warnings []string `json:"warnings"`
+	}{}
+	if err := json.Unmarshal(b, &data); err != nil {
+		return nil, err
+	}
+
+	acl = &ACLHuJSON{
+		ACL:      string(data.ACL),
+		Warnings: data.Warnings,
+		ETag:     resp.Header.Get("ETag"),
+	}
+	return acl, nil
+}
+
+// ACLTestFailureSummary specifies a user for which ACL tests
+// failed and the related user-friendly error messages.
+//
+// ACLTestFailureSummary specifies the JSON format sent to the
+// JavaScript client to be rendered in the HTML.
+type ACLTestFailureSummary struct {
+	User   string   `json:"user"`
+	Errors []string `json:"errors"`
+}
+
+// ACLTestError is ErrResponse but with an extra field to account for ACLTestFailureSummary.
+type ACLTestError struct {
+	ErrResponse
+	Data []ACLTestFailureSummary `json:"data"`
+}
+
+func (e ACLTestError) Error() string {
+	return fmt.Sprintf("%s, Data: %+v", e.ErrResponse.Error(), e.Data)
+}
+
+func (c *Client) aclPOSTRequest(ctx context.Context, body []byte, avoidCollisions bool, etag, acceptHeader string) ([]byte, string, error) {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/acl", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewBuffer(body))
+	if err != nil {
+		return nil, "", err
+	}
+
+	if avoidCollisions {
+		req.Header.Set("If-Match", etag)
+	}
+	req.Header.Set("Accept", acceptHeader)
+	req.Header.Set("Content-Type", "application/hujson")
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, "", err
+	}
+
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		// check if test error
+		var ate ACLTestError
+		if err := json.Unmarshal(b, &ate); err != nil {
+			return nil, "", err
+		}
+		ate.Status = resp.StatusCode
+		return nil, "", ate
+	}
+	return b, resp.Header.Get("ETag"), nil
+}
+
+// SetACL sends a POST request to update the ACL according to the provided ACL object. If
+// `avoidCollisions` is true, it will use the ETag obtained in the GET request in an If-Match
+// header to check if the previously obtained ACL was the latest version and that no updates
+// were missed.
+//
+// Returns error with status code 412 if mistmached ETag and avoidCollisions is set to true.
+// Returns error if ACL has tests that fail.
+// Returns error if there are other errors with the ACL.
+func (c *Client) SetACL(ctx context.Context, acl ACL, avoidCollisions bool) (res *ACL, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetACL: %w", err)
+		}
+	}()
+	postData, err := json.Marshal(acl.ACL)
+	if err != nil {
+		return nil, err
+	}
+	b, etag, err := c.aclPOSTRequest(ctx, postData, avoidCollisions, acl.ETag, "application/json")
+	if err != nil {
+		return nil, err
+	}
+
+	// Otherwise, try to decode the response.
+	var aclDetails ACLDetails
+	if err = json.Unmarshal(b, &aclDetails); err != nil {
+		return nil, err
+	}
+	res = &ACL{
+		ACL:  aclDetails,
+		ETag: etag,
+	}
+	return res, nil
+}
+
+// SetACLHuJSON sends a POST request to update the ACL according to the provided ACL object. If
+// `avoidCollisions` is true, it will use the ETag obtained in the GET request in an If-Match
+// header to check if the previously obtained ACL was the latest version and that no updates
+// were missed.
+//
+// Returns error with status code 412 if mistmached ETag and avoidCollisions is set to true.
+// Returns error if the HuJSON is invalid.
+// Returns error if ACL has tests that fail.
+// Returns error if there are other errors with the ACL.
+func (c *Client) SetACLHuJSON(ctx context.Context, acl ACLHuJSON, avoidCollisions bool) (res *ACLHuJSON, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetACLHuJSON: %w", err)
+		}
+	}()
+
+	postData := []byte(acl.ACL)
+	b, etag, err := c.aclPOSTRequest(ctx, postData, avoidCollisions, acl.ETag, "application/hujson")
+	if err != nil {
+		return nil, err
+	}
+
+	res = &ACLHuJSON{
+		ACL:  string(b),
+		ETag: etag,
+	}
+	return res, nil
+}
+
+// UserRuleMatch specifies the source users/groups/hosts that a rule targets
+// and the destination ports that they can access.
+// LineNumber is only useful for requests provided in HuJSON form.
+// While JSON requests will have LineNumber, the value is not useful.
+type UserRuleMatch struct {
+	Users      []string `json:"users"`
+	Ports      []string `json:"ports"`
+	LineNumber int      `json:"lineNumber"`
+}
+
+// ACLPreviewResponse is the response type of previewACLPostRequest
+type ACLPreviewResponse struct {
+	Matches    []UserRuleMatch `json:"matches"`    // ACL rules that match the specified user or ipport.
+	Type       string          `json:"type"`       // The request type: currently only "user" or "ipport".
+	PreviewFor string          `json:"previewFor"` // A specific user or ipport.
+}
+
+// ACLPreview is the response type of PreviewACLForUser, PreviewACLForIPPort, PreviewACLHuJSONForUser, and PreviewACLHuJSONForIPPort
+type ACLPreview struct {
+	Matches []UserRuleMatch `json:"matches"`
+	User    string          `json:"user,omitempty"`   // Filled if response of PreviewACLForUser or PreviewACLHuJSONForUser
+	IPPort  string          `json:"ipport,omitempty"` // Filled if response of PreviewACLForIPPort or PreviewACLHuJSONForIPPort
+}
+
+func (c *Client) previewACLPostRequest(ctx context.Context, body []byte, previewType string, previewFor string) (res *ACLPreviewResponse, err error) {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/acl/preview", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewBuffer(body))
+	if err != nil {
+		return nil, err
+	}
+
+	q := req.URL.Query()
+	q.Add("type", previewType)
+	q.Add("previewFor", previewFor)
+	req.URL.RawQuery = q.Encode()
+
+	req.Header.Set("Content-Type", "application/hujson")
+	c.setAuth(req)
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+	if err = json.Unmarshal(b, &res); err != nil {
+		return nil, err
+	}
+
+	return res, nil
+}
+
+// PreviewACLForUser determines what rules match a given ACL for a user.
+// The ACL can be a locally modified or clean ACL obtained from server.
+//
+// Returns ACLPreview on success with matches in a slice. If there are no matches,
+// the call is still successful but Matches will be an empty slice.
+// Returns error if the provided ACL is invalid.
+func (c *Client) PreviewACLForUser(ctx context.Context, acl ACL, user string) (res *ACLPreview, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.PreviewACLForUser: %w", err)
+		}
+	}()
+	postData, err := json.Marshal(acl.ACL)
+	if err != nil {
+		return nil, err
+	}
+	b, err := c.previewACLPostRequest(ctx, postData, "user", user)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ACLPreview{
+		Matches: b.Matches,
+		User:    b.PreviewFor,
+	}, nil
+}
+
+// PreviewACLForIPPort determines what rules match a given ACL for a ipport.
+// The ACL can be a locally modified or clean ACL obtained from server.
+//
+// Returns ACLPreview on success with matches in a slice. If there are no matches,
+// the call is still successful but Matches will be an empty slice.
+// Returns error if the provided ACL is invalid.
+func (c *Client) PreviewACLForIPPort(ctx context.Context, acl ACL, ipport netip.AddrPort) (res *ACLPreview, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.PreviewACLForIPPort: %w", err)
+		}
+	}()
+	postData, err := json.Marshal(acl.ACL)
+	if err != nil {
+		return nil, err
+	}
+	b, err := c.previewACLPostRequest(ctx, postData, "ipport", ipport.String())
+	if err != nil {
+		return nil, err
+	}
+
+	return &ACLPreview{
+		Matches: b.Matches,
+		IPPort:  b.PreviewFor,
+	}, nil
+}
+
+// PreviewACLHuJSONForUser determines what rules match a given ACL for a user.
+// The ACL can be a locally modified or clean ACL obtained from server.
+//
+// Returns ACLPreview on success with matches in a slice. If there are no matches,
+// the call is still successful but Matches will be an empty slice.
+// Returns error if the provided ACL is invalid.
+func (c *Client) PreviewACLHuJSONForUser(ctx context.Context, acl ACLHuJSON, user string) (res *ACLPreview, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.PreviewACLHuJSONForUser: %w", err)
+		}
+	}()
+	postData := []byte(acl.ACL)
+	b, err := c.previewACLPostRequest(ctx, postData, "user", user)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ACLPreview{
+		Matches: b.Matches,
+		User:    b.PreviewFor,
+	}, nil
+}
+
+// PreviewACLHuJSONForIPPort determines what rules match a given ACL for a ipport.
+// The ACL can be a locally modified or clean ACL obtained from server.
+//
+// Returns ACLPreview on success with matches in a slice. If there are no matches,
+// the call is still successful but Matches will be an empty slice.
+// Returns error if the provided ACL is invalid.
+func (c *Client) PreviewACLHuJSONForIPPort(ctx context.Context, acl ACLHuJSON, ipport string) (res *ACLPreview, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.PreviewACLHuJSONForIPPort: %w", err)
+		}
+	}()
+	postData := []byte(acl.ACL)
+	b, err := c.previewACLPostRequest(ctx, postData, "ipport", ipport)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ACLPreview{
+		Matches: b.Matches,
+		IPPort:  b.PreviewFor,
+	}, nil
+}
+
+// ValidateACLJSON takes in the given source and destination (in this situation,
+// it is assumed that you are checking whether the source can connect to destination)
+// and creates an ACLTest from that. It then sends the ACLTest to the control api acl
+// validate endpoint, where the test is run. It returns a nil ACLTestError pointer if
+// no test errors occur.
+func (c *Client) ValidateACLJSON(ctx context.Context, source, dest string) (testErr *ACLTestError, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.ValidateACLJSON: %w", err)
+		}
+	}()
+
+	tests := []ACLTest{ACLTest{User: source, Allow: []string{dest}}}
+	postData, err := json.Marshal(tests)
+	if err != nil {
+		return nil, err
+	}
+
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/acl/validate", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewBuffer(postData))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	c.setAuth(req)
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("control api responsed with %d status code", resp.StatusCode)
+	}
+
+	// The test ran without fail
+	if len(b) == 0 {
+		return nil, nil
+	}
+
+	var res ACLTestError
+	// The test returned errors.
+	if err = json.Unmarshal(b, &res); err != nil {
+		// failed to unmarshal
+		return nil, err
+	}
+	return &res, nil
+}

client/tailscale/apitype/apitype.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 apitype contains types for the Tailscale local API.
+// Package apitype contains types for the Tailscale local API and control plane API.
 package apitype
 
 import "tailscale.com/tailcfg"
@@ -11,6 +11,9 @@ import "tailscale.com/tailcfg"
 type WhoIsResponse struct {
 	Node        *tailcfg.Node
 	UserProfile *tailcfg.UserProfile
+
+	// Caps are extra capabilities that the remote Node has to this node.
+	Caps []string `json:",omitempty"`
 }
 
 // FileTarget is a node to which files can be sent, and the PeerAPI

client/tailscale/apitype/controltype.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2022 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 apitype
+
+type DNSConfig struct {
+	Resolvers         []DNSResolver            `json:"resolvers"`
+	FallbackResolvers []DNSResolver            `json:"fallbackResolvers"`
+	Routes            map[string][]DNSResolver `json:"routes"`
+	Domains           []string                 `json:"domains"`
+	Nameservers       []string                 `json:"nameservers"`
+	Proxied           bool                     `json:"proxied"`
+	PerDomain         bool                     `json:",omitempty"`
+}
+
+type DNSResolver struct {
+	Addr                string   `json:"addr"`
+	BootstrapResolution []string `json:"bootstrapResolution,omitempty"`
+}

client/tailscale/devices.go

@@ -0,0 +1,262 @@
+// Copyright (c) 2022 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 go1.19
+// +build go1.19
+
+package tailscale
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"tailscale.com/types/opt"
+)
+
+type GetDevicesResponse struct {
+	Devices []*Device `json:"devices"`
+}
+
+type DerpRegion struct {
+	Preferred           bool    `json:"preferred,omitempty"`
+	LatencyMilliseconds float64 `json:"latencyMs"`
+}
+
+type ClientConnectivity struct {
+	Endpoints             []string `json:"endpoints"`
+	DERP                  string   `json:"derp"`
+	MappingVariesByDestIP opt.Bool `json:"mappingVariesByDestIP"`
+	// DERPLatency is mapped by region name (e.g. "New York City", "Seattle").
+	DERPLatency    map[string]DerpRegion `json:"latency"`
+	ClientSupports map[string]opt.Bool   `json:"clientSupports"`
+}
+
+type Device struct {
+	// Addresses is a list of the devices's Tailscale IP addresses.
+	// It's currently just 1 element, the 100.x.y.z Tailscale IP.
+	Addresses []string `json:"addresses"`
+	DeviceID  string   `json:"id"`
+	User      string   `json:"user"`
+	Name      string   `json:"name"`
+	Hostname  string   `json:"hostname"`
+
+	ClientVersion     string `json:"clientVersion"`   // Empty for external devices.
+	UpdateAvailable   bool   `json:"updateAvailable"` // Empty for external devices.
+	OS                string `json:"os"`
+	Created           string `json:"created"` // Empty for external devices.
+	LastSeen          string `json:"lastSeen"`
+	KeyExpiryDisabled bool   `json:"keyExpiryDisabled"`
+	Expires           string `json:"expires"`
+	Authorized        bool   `json:"authorized"`
+	IsExternal        bool   `json:"isExternal"`
+	MachineKey        string `json:"machineKey"` // Empty for external devices.
+	NodeKey           string `json:"nodeKey"`
+
+	// BlocksIncomingConnections is configured via the device's
+	// Tailscale client preferences. This field is only reported
+	// to the API starting with Tailscale 1.3.x clients.
+	BlocksIncomingConnections bool `json:"blocksIncomingConnections"`
+
+	// The following fields are not included by default:
+
+	// EnabledRoutes are the previously-approved subnet routes
+	// (e.g. "192.168.4.16/24", "10.5.2.4/32").
+	EnabledRoutes []string `json:"enabledRoutes"` // Empty for external devices.
+	// AdvertisedRoutes are the subnets (both enabled and not enabled)
+	// being requested from the node.
+	AdvertisedRoutes []string `json:"advertisedRoutes"` // Empty for external devices.
+
+	ClientConnectivity *ClientConnectivity `json:"clientConnectivity"`
+}
+
+// DeviceFieldsOpts determines which fields should be returned in the response.
+//
+// Please only use DeviceAllFields and DeviceDefaultFields.
+// Other DeviceFieldsOpts are not supported.
+//
+// TODO: Support other DeviceFieldsOpts.
+// In the future, users should be able to create their own DeviceFieldsOpts
+// as valid arguments by setting the fields they want returned to a "non-nil"
+// value. For example, DeviceFieldsOpts{NodeID: "true"} should only return NodeIDs.
+type DeviceFieldsOpts Device
+
+func (d *DeviceFieldsOpts) addFieldsToQueryParameter() string {
+	if d == DeviceDefaultFields || d == nil {
+		return "default"
+	}
+	if d == DeviceAllFields {
+		return "all"
+	}
+
+	return ""
+}
+
+var (
+	DeviceAllFields = &DeviceFieldsOpts{}
+
+	// DeviceDefaultFields specifies that the following fields are returned:
+	//   Addresses, NodeID, User, Name, Hostname, ClientVersion, UpdateAvailable,
+	//   OS, Created, LastSeen, KeyExpiryDisabled, Expires, Authorized, IsExternal
+	//   MachineKey, NodeKey, BlocksIncomingConnections.
+	DeviceDefaultFields = &DeviceFieldsOpts{}
+)
+
+// Devices retrieves the list of devices for a tailnet.
+//
+// See the Device structure for the list of fields hidden for external devices.
+// The optional fields parameter specifies which fields of the devices to return; currently
+// only DeviceDefaultFields (equivalent to nil) and DeviceAllFields are supported.
+// Other values are currently undefined.
+func (c *Client) Devices(ctx context.Context, fields *DeviceFieldsOpts) (deviceList []*Device, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.Devices: %w", err)
+		}
+	}()
+
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/devices", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+	// Add fields.
+	fieldStr := fields.addFieldsToQueryParameter()
+	q := req.URL.Query()
+	q.Add("fields", fieldStr)
+	req.URL.RawQuery = q.Encode()
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	var devices GetDevicesResponse
+	err = json.Unmarshal(b, &devices)
+	return devices.Devices, err
+}
+
+// Device retrieved the details for a specific device.
+//
+// See the Device structure for the list of fields hidden for an external device.
+// The optional fields parameter specifies which fields of the devices to return; currently
+// only DeviceDefaultFields (equivalent to nil) and DeviceAllFields are supported.
+// Other values are currently undefined.
+func (c *Client) Device(ctx context.Context, deviceID string, fields *DeviceFieldsOpts) (device *Device, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.Device: %w", err)
+		}
+	}()
+	path := fmt.Sprintf("%s/api/v2/device/%s", c.baseURL(), deviceID)
+	req, err := http.NewRequestWithContext(ctx, "GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Add fields.
+	fieldStr := fields.addFieldsToQueryParameter()
+	q := req.URL.Query()
+	q.Add("fields", fieldStr)
+	req.URL.RawQuery = q.Encode()
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	err = json.Unmarshal(b, &device)
+	return device, err
+}
+
+// DeleteDevice deletes the specified device from the Client's tailnet.
+// NOTE: Only devices that belong to the Client's tailnet can be deleted.
+// Deleting external devices is not supported.
+func (c *Client) DeleteDevice(ctx context.Context, deviceID string) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.DeleteDevice: %w", err)
+		}
+	}()
+
+	path := fmt.Sprintf("%s/api/v2/device/%s", c.baseURL(), url.PathEscape(deviceID))
+	req, err := http.NewRequestWithContext(ctx, "DELETE", path, nil)
+	if err != nil {
+		return err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return handleErrorResponse(b, resp)
+	}
+	return nil
+}
+
+// AuthorizeDevice marks a device as authorized.
+func (c *Client) AuthorizeDevice(ctx context.Context, deviceID string) error {
+	path := fmt.Sprintf("%s/api/v2/device/%s/authorized", c.baseURL(), url.PathEscape(deviceID))
+	req, err := http.NewRequestWithContext(ctx, "POST", path, strings.NewReader(`{"authorized":true}`))
+	if err != nil {
+		return err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return handleErrorResponse(b, resp)
+	}
+
+	return nil
+}
+
+// SetTags updates the ACL tags on a device.
+func (c *Client) SetTags(ctx context.Context, deviceID string, tags []string) error {
+	params := &struct {
+		Tags []string `json:"tags"`
+	}{Tags: tags}
+	data, err := json.Marshal(params)
+	if err != nil {
+		return err
+	}
+	path := fmt.Sprintf("%s/api/v2/device/%s/tags", c.baseURL(), url.PathEscape(deviceID))
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewBuffer(data))
+	if err != nil {
+		return err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return handleErrorResponse(b, resp)
+	}
+
+	return nil
+}

client/tailscale/dns.go

@@ -0,0 +1,235 @@
+// Copyright (c) 2022 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 go1.19
+// +build go1.19
+
+package tailscale
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"tailscale.com/client/tailscale/apitype"
+)
+
+// DNSNameServers is returned when retrieving the list of nameservers.
+// It is also the structure provided when setting nameservers.
+type DNSNameServers struct {
+	DNS []string `json:"dns"` // DNS name servers
+}
+
+// DNSNameServersPostResponse is returned when setting the list of DNS nameservers.
+//
+// It includes the MagicDNS status since nameservers changes may affect MagicDNS.
+type DNSNameServersPostResponse struct {
+	DNS      []string `json:"dns"`      // DNS name servers
+	MagicDNS bool     `json:"magicDNS"` // whether MagicDNS is active for this tailnet (enabled + has fallback nameservers)
+}
+
+// DNSSearchpaths is the list of search paths for a given domain.
+type DNSSearchPaths struct {
+	SearchPaths []string `json:"searchPaths"` // DNS search paths
+}
+
+// DNSPreferences is the preferences set for a given tailnet.
+//
+// It includes MagicDNS which can be turned on or off. To enable MagicDNS,
+// there must be at least one nameserver. When all nameservers are removed,
+// MagicDNS is disabled.
+type DNSPreferences struct {
+	MagicDNS bool `json:"magicDNS"` // whether MagicDNS is active for this tailnet (enabled + has fallback nameservers)
+}
+
+func (c *Client) dnsGETRequest(ctx context.Context, endpoint string) ([]byte, error) {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/dns/%s", c.baseURL(), c.tailnet, endpoint)
+	req, err := http.NewRequestWithContext(ctx, "GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	return b, nil
+}
+
+func (c *Client) dnsPOSTRequest(ctx context.Context, endpoint string, postData interface{}) ([]byte, error) {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/dns/%s", c.baseURL(), c.tailnet, endpoint)
+	data, err := json.Marshal(&postData)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewBuffer(data))
+	req.Header.Set("Content-Type", "application/json")
+	if err != nil {
+		return nil, err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	return b, nil
+}
+
+// DNSConfig retrieves the DNSConfig settings for a domain.
+func (c *Client) DNSConfig(ctx context.Context) (cfg *apitype.DNSConfig, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.DNSConfig: %w", err)
+		}
+	}()
+	b, err := c.dnsGETRequest(ctx, "config")
+	if err != nil {
+		return nil, err
+	}
+	var dnsResp apitype.DNSConfig
+	err = json.Unmarshal(b, &dnsResp)
+	return &dnsResp, err
+}
+
+func (c *Client) SetDNSConfig(ctx context.Context, cfg apitype.DNSConfig) (resp *apitype.DNSConfig, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetDNSConfig: %w", err)
+		}
+	}()
+	var dnsResp apitype.DNSConfig
+	b, err := c.dnsPOSTRequest(ctx, "config", cfg)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(b, &dnsResp)
+	return &dnsResp, err
+}
+
+// NameServers retrieves the list of nameservers set for a domain.
+func (c *Client) NameServers(ctx context.Context) (nameservers []string, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.NameServers: %w", err)
+		}
+	}()
+	b, err := c.dnsGETRequest(ctx, "nameservers")
+	if err != nil {
+		return nil, err
+	}
+	var dnsResp DNSNameServers
+	err = json.Unmarshal(b, &dnsResp)
+	return dnsResp.DNS, err
+}
+
+// SetNameServers sets the list of nameservers for a tailnet to the list provided
+// by the user.
+//
+// It returns the new list of nameservers and the MagicDNS status in case it was
+// affected by the change. For example, removing all nameservers will turn off
+// MagicDNS.
+func (c *Client) SetNameServers(ctx context.Context, nameservers []string) (dnsResp *DNSNameServersPostResponse, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetNameServers: %w", err)
+		}
+	}()
+	dnsReq := DNSNameServers{DNS: nameservers}
+	b, err := c.dnsPOSTRequest(ctx, "nameservers", dnsReq)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(b, &dnsResp)
+	return dnsResp, err
+}
+
+// DNSPreferences retrieves the DNS preferences set for a tailnet.
+//
+// It returns the status of MagicDNS.
+func (c *Client) DNSPreferences(ctx context.Context) (dnsResp *DNSPreferences, err error) {
+	// Format return errors to be descriptive.
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.DNSPreferences: %w", err)
+		}
+	}()
+	b, err := c.dnsGETRequest(ctx, "preferences")
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(b, &dnsResp)
+	return dnsResp, err
+}
+
+// SetDNSPreferences sets the DNS preferences for a tailnet.
+//
+// MagicDNS can only be enabled when there is at least one nameserver provided.
+// When all nameservers are removed, MagicDNS is disabled and will stay disabled,
+// unless explicitly enabled by a user again.
+func (c *Client) SetDNSPreferences(ctx context.Context, magicDNS bool) (dnsResp *DNSPreferences, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetDNSPreferences: %w", err)
+		}
+	}()
+	dnsReq := DNSPreferences{MagicDNS: magicDNS}
+	b, err := c.dnsPOSTRequest(ctx, "preferences", dnsReq)
+	if err != nil {
+		return
+	}
+	err = json.Unmarshal(b, &dnsResp)
+	return dnsResp, err
+}
+
+// SearchPaths retrieves the list of searchpaths set for a tailnet.
+func (c *Client) SearchPaths(ctx context.Context) (searchpaths []string, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SearchPaths: %w", err)
+		}
+	}()
+	b, err := c.dnsGETRequest(ctx, "searchpaths")
+	if err != nil {
+		return nil, err
+	}
+	var dnsResp *DNSSearchPaths
+	err = json.Unmarshal(b, &dnsResp)
+	return dnsResp.SearchPaths, err
+}
+
+// SetSearchPaths sets the list of searchpaths for a tailnet.
+func (c *Client) SetSearchPaths(ctx context.Context, searchpaths []string) (newSearchPaths []string, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetSearchPaths: %w", err)
+		}
+	}()
+	dnsReq := DNSSearchPaths{SearchPaths: searchpaths}
+	b, err := c.dnsPOSTRequest(ctx, "searchpaths", dnsReq)
+	if err != nil {
+		return nil, err
+	}
+	var dnsResp DNSSearchPaths
+	err = json.Unmarshal(b, &dnsResp)
+	return dnsResp.SearchPaths, err
+}

client/tailscale/example/servetls/servetls.go

@@ -0,0 +1,29 @@
+// 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 servetls program shows how to run an HTTPS server
+// using a Tailscale cert via LetsEncrypt.
+package main
+
+import (
+	"crypto/tls"
+	"io"
+	"log"
+	"net/http"
+
+	"tailscale.com/client/tailscale"
+)
+
+func main() {
+	s := &http.Server{
+		TLSConfig: &tls.Config{
+			GetCertificate: tailscale.GetCertificate,
+		},
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			io.WriteString(w, "<h1>Hello from Tailscale!</h1> It works.")
+		}),
+	}
+	log.Printf("Running TLS server on :443 ...")
+	log.Fatal(s.ListenAndServeTLS("", ""))
+}

client/tailscale/localclient.go

@@ -0,0 +1,748 @@
+// 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 go1.19
+// +build go1.19
+
+package tailscale
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/http/httptrace"
+	"net/netip"
+	"net/url"
+	"os/exec"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"go4.org/mem"
+	"tailscale.com/client/tailscale/apitype"
+	"tailscale.com/ipn"
+	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/net/netutil"
+	"tailscale.com/paths"
+	"tailscale.com/safesocket"
+	"tailscale.com/tailcfg"
+	"tailscale.com/tka"
+)
+
+// defaultLocalClient is the default LocalClient when using the legacy
+// package-level functions.
+var defaultLocalClient LocalClient
+
+// LocalClient is a client to Tailscale's "local API", communicating with the
+// Tailscale daemon on the local machine. Its API is not necessarily stable and
+// subject to changes between releases. Some API calls have stricter
+// compatibility guarantees, once they've been widely adopted. See method docs
+// for details.
+//
+// Its zero value is valid to use.
+//
+// Any exported fields should be set before using methods on the type
+// and not changed thereafter.
+type LocalClient struct {
+	// Dial optionally specifies an alternate func that connects to the local
+	// machine's tailscaled or equivalent. If nil, a default is used.
+	Dial func(ctx context.Context, network, addr string) (net.Conn, error)
+
+	// Socket specifies an alternate path to the local Tailscale socket.
+	// If empty, a platform-specific default is used.
+	Socket string
+
+	// UseSocketOnly, if true, tries to only connect to tailscaled via the
+	// Unix socket and not via fallback mechanisms as done on macOS when
+	// connecting to the GUI client variants.
+	UseSocketOnly bool
+
+	// tsClient does HTTP requests to the local Tailscale daemon.
+	// It's lazily initialized on first use.
+	tsClient     *http.Client
+	tsClientOnce sync.Once
+}
+
+func (lc *LocalClient) socket() string {
+	if lc.Socket != "" {
+		return lc.Socket
+	}
+	return paths.DefaultTailscaledSocket()
+}
+
+func (lc *LocalClient) dialer() func(ctx context.Context, network, addr string) (net.Conn, error) {
+	if lc.Dial != nil {
+		return lc.Dial
+	}
+	return lc.defaultDialer
+}
+
+func (lc *LocalClient) defaultDialer(ctx context.Context, network, addr string) (net.Conn, error) {
+	if addr != "local-tailscaled.sock:80" {
+		return nil, fmt.Errorf("unexpected URL address %q", addr)
+	}
+	if !lc.UseSocketOnly {
+		// On macOS, when dialing from non-sandboxed program to sandboxed GUI running
+		// a TCP server on a random port, find the random port. For HTTP connections,
+		// we don't send the token. It gets added in an HTTP Basic-Auth header.
+		if port, _, err := safesocket.LocalTCPPortAndToken(); err == nil {
+			var d net.Dialer
+			return d.DialContext(ctx, "tcp", "localhost:"+strconv.Itoa(port))
+		}
+	}
+	s := safesocket.DefaultConnectionStrategy(lc.socket())
+	// The user provided a non-default tailscaled socket address.
+	// Connect only to exactly what they provided.
+	s.UseFallback(false)
+	return safesocket.Connect(s)
+}
+
+// DoLocalRequest makes an HTTP request to the local machine's Tailscale daemon.
+//
+// URLs are of the form http://local-tailscaled.sock/localapi/v0/whois?ip=1.2.3.4.
+//
+// The hostname must be "local-tailscaled.sock", even though it
+// doesn't actually do any DNS lookup. The actual means of connecting to and
+// authenticating to the local Tailscale daemon vary by platform.
+//
+// DoLocalRequest may mutate the request to add Authorization headers.
+func (lc *LocalClient) DoLocalRequest(req *http.Request) (*http.Response, error) {
+	lc.tsClientOnce.Do(func() {
+		lc.tsClient = &http.Client{
+			Transport: &http.Transport{
+				DialContext: lc.dialer(),
+			},
+		}
+	})
+	if _, token, err := safesocket.LocalTCPPortAndToken(); err == nil {
+		req.SetBasicAuth("", token)
+	}
+	return lc.tsClient.Do(req)
+}
+
+func (lc *LocalClient) doLocalRequestNiceError(req *http.Request) (*http.Response, error) {
+	res, err := lc.DoLocalRequest(req)
+	if err == nil {
+		if server := res.Header.Get("Tailscale-Version"); server != "" && server != ipn.IPCVersion() && onVersionMismatch != nil {
+			onVersionMismatch(ipn.IPCVersion(), server)
+		}
+		if res.StatusCode == 403 {
+			all, _ := ioutil.ReadAll(res.Body)
+			return nil, &AccessDeniedError{errors.New(errorMessageFromBody(all))}
+		}
+		return res, nil
+	}
+	if ue, ok := err.(*url.Error); ok {
+		if oe, ok := ue.Err.(*net.OpError); ok && oe.Op == "dial" {
+			path := req.URL.Path
+			pathPrefix, _, _ := strings.Cut(path, "?")
+			return nil, fmt.Errorf("Failed to connect to local Tailscale daemon for %s; %s Error: %w", pathPrefix, tailscaledConnectHint(), oe)
+		}
+	}
+	return nil, err
+}
+
+type errorJSON struct {
+	Error string
+}
+
+// AccessDeniedError is an error due to permissions.
+type AccessDeniedError struct {
+	err error
+}
+
+func (e *AccessDeniedError) Error() string { return fmt.Sprintf("Access denied: %v", e.err) }
+func (e *AccessDeniedError) Unwrap() error { return e.err }
+
+// IsAccessDeniedError reports whether err is or wraps an AccessDeniedError.
+func IsAccessDeniedError(err error) bool {
+	var ae *AccessDeniedError
+	return errors.As(err, &ae)
+}
+
+// bestError returns either err, or if body contains a valid JSON
+// object of type errorJSON, its non-empty error body.
+func bestError(err error, body []byte) error {
+	var j errorJSON
+	if err := json.Unmarshal(body, &j); err == nil && j.Error != "" {
+		return errors.New(j.Error)
+	}
+	return err
+}
+
+func errorMessageFromBody(body []byte) string {
+	var j errorJSON
+	if err := json.Unmarshal(body, &j); err == nil && j.Error != "" {
+		return j.Error
+	}
+	return strings.TrimSpace(string(body))
+}
+
+var onVersionMismatch func(clientVer, serverVer string)
+
+// SetVersionMismatchHandler sets f as the version mismatch handler
+// to be called when the client (the current process) has a version
+// number that doesn't match the server's declared version.
+func SetVersionMismatchHandler(f func(clientVer, serverVer string)) {
+	onVersionMismatch = f
+}
+
+func (lc *LocalClient) send(ctx context.Context, method, path string, wantStatus int, body io.Reader) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, method, "http://local-tailscaled.sock"+path, body)
+	if err != nil {
+		return nil, err
+	}
+	res, err := lc.doLocalRequestNiceError(req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+	slurp, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode != wantStatus {
+		err = fmt.Errorf("%v: %s", res.Status, bytes.TrimSpace(slurp))
+		return nil, bestError(err, slurp)
+	}
+	return slurp, nil
+}
+
+func (lc *LocalClient) get200(ctx context.Context, path string) ([]byte, error) {
+	return lc.send(ctx, "GET", path, 200, nil)
+}
+
+// WhoIs returns the owner of the remoteAddr, which must be an IP or IP:port.
+//
+// Deprecated: use LocalClient.WhoIs.
+func WhoIs(ctx context.Context, remoteAddr string) (*apitype.WhoIsResponse, error) {
+	return defaultLocalClient.WhoIs(ctx, remoteAddr)
+}
+
+// WhoIs returns the owner of the remoteAddr, which must be an IP or IP:port.
+func (lc *LocalClient) WhoIs(ctx context.Context, remoteAddr string) (*apitype.WhoIsResponse, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/whois?addr="+url.QueryEscape(remoteAddr))
+	if err != nil {
+		return nil, err
+	}
+	r := new(apitype.WhoIsResponse)
+	if err := json.Unmarshal(body, r); err != nil {
+		if max := 200; len(body) > max {
+			body = append(body[:max], "..."...)
+		}
+		return nil, fmt.Errorf("failed to parse JSON WhoIsResponse from %q", body)
+	}
+	return r, nil
+}
+
+// Goroutines returns a dump of the Tailscale daemon's current goroutines.
+func (lc *LocalClient) Goroutines(ctx context.Context) ([]byte, error) {
+	return lc.get200(ctx, "/localapi/v0/goroutines")
+}
+
+// DaemonMetrics returns the Tailscale daemon's metrics in
+// the Prometheus text exposition format.
+func (lc *LocalClient) DaemonMetrics(ctx context.Context) ([]byte, error) {
+	return lc.get200(ctx, "/localapi/v0/metrics")
+}
+
+// Profile returns a pprof profile of the Tailscale daemon.
+func (lc *LocalClient) Profile(ctx context.Context, pprofType string, sec int) ([]byte, error) {
+	var secArg string
+	if sec < 0 || sec > 300 {
+		return nil, errors.New("duration out of range")
+	}
+	if sec != 0 || pprofType == "profile" {
+		secArg = fmt.Sprint(sec)
+	}
+	return lc.get200(ctx, fmt.Sprintf("/localapi/v0/profile?name=%s&seconds=%v", url.QueryEscape(pprofType), secArg))
+}
+
+// BugReport logs and returns a log marker that can be shared by the user with support.
+func (lc *LocalClient) BugReport(ctx context.Context, note string) (string, error) {
+	body, err := lc.send(ctx, "POST", "/localapi/v0/bugreport?note="+url.QueryEscape(note), 200, nil)
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(string(body)), nil
+}
+
+// DebugAction invokes a debug action, such as "rebind" or "restun".
+// These are development tools and subject to change or removal over time.
+func (lc *LocalClient) DebugAction(ctx context.Context, action string) error {
+	body, err := lc.send(ctx, "POST", "/localapi/v0/debug?action="+url.QueryEscape(action), 200, nil)
+	if err != nil {
+		return fmt.Errorf("error %w: %s", err, body)
+	}
+	return nil
+}
+
+// Status returns the Tailscale daemon's status.
+func Status(ctx context.Context) (*ipnstate.Status, error) {
+	return defaultLocalClient.Status(ctx)
+}
+
+// Status returns the Tailscale daemon's status.
+func (lc *LocalClient) Status(ctx context.Context) (*ipnstate.Status, error) {
+	return lc.status(ctx, "")
+}
+
+// StatusWithoutPeers returns the Tailscale daemon's status, without the peer info.
+func StatusWithoutPeers(ctx context.Context) (*ipnstate.Status, error) {
+	return defaultLocalClient.StatusWithoutPeers(ctx)
+}
+
+// StatusWithoutPeers returns the Tailscale daemon's status, without the peer info.
+func (lc *LocalClient) StatusWithoutPeers(ctx context.Context) (*ipnstate.Status, error) {
+	return lc.status(ctx, "?peers=false")
+}
+
+func (lc *LocalClient) status(ctx context.Context, queryString string) (*ipnstate.Status, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/status"+queryString)
+	if err != nil {
+		return nil, err
+	}
+	st := new(ipnstate.Status)
+	if err := json.Unmarshal(body, st); err != nil {
+		return nil, err
+	}
+	return st, nil
+}
+
+// IDToken is a request to get an OIDC ID token for an audience.
+// The token can be presented to any resource provider which offers OIDC
+// Federation.
+func (lc *LocalClient) IDToken(ctx context.Context, aud string) (*tailcfg.TokenResponse, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/id-token?aud="+url.QueryEscape(aud))
+	if err != nil {
+		return nil, err
+	}
+	tr := new(tailcfg.TokenResponse)
+	if err := json.Unmarshal(body, tr); err != nil {
+		return nil, err
+	}
+	return tr, nil
+}
+
+func (lc *LocalClient) WaitingFiles(ctx context.Context) ([]apitype.WaitingFile, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/files/")
+	if err != nil {
+		return nil, err
+	}
+	var wfs []apitype.WaitingFile
+	if err := json.Unmarshal(body, &wfs); err != nil {
+		return nil, err
+	}
+	return wfs, nil
+}
+
+func (lc *LocalClient) DeleteWaitingFile(ctx context.Context, baseName string) error {
+	_, err := lc.send(ctx, "DELETE", "/localapi/v0/files/"+url.PathEscape(baseName), http.StatusNoContent, nil)
+	return err
+}
+
+func (lc *LocalClient) GetWaitingFile(ctx context.Context, baseName string) (rc io.ReadCloser, size int64, err error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/files/"+url.PathEscape(baseName), nil)
+	if err != nil {
+		return nil, 0, err
+	}
+	res, err := lc.doLocalRequestNiceError(req)
+	if err != nil {
+		return nil, 0, err
+	}
+	if res.ContentLength == -1 {
+		res.Body.Close()
+		return nil, 0, fmt.Errorf("unexpected chunking")
+	}
+	if res.StatusCode != 200 {
+		body, _ := ioutil.ReadAll(res.Body)
+		res.Body.Close()
+		return nil, 0, fmt.Errorf("HTTP %s: %s", res.Status, body)
+	}
+	return res.Body, res.ContentLength, nil
+}
+
+func (lc *LocalClient) FileTargets(ctx context.Context) ([]apitype.FileTarget, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/file-targets")
+	if err != nil {
+		return nil, err
+	}
+	var fts []apitype.FileTarget
+	if err := json.Unmarshal(body, &fts); err != nil {
+		return nil, fmt.Errorf("invalid JSON: %w", err)
+	}
+	return fts, nil
+}
+
+// PushFile sends Taildrop file r to target.
+//
+// A size of -1 means unknown.
+// The name parameter is the original filename, not escaped.
+func (lc *LocalClient) PushFile(ctx context.Context, target tailcfg.StableNodeID, size int64, name string, r io.Reader) error {
+	req, err := http.NewRequestWithContext(ctx, "PUT", "http://local-tailscaled.sock/localapi/v0/file-put/"+string(target)+"/"+url.PathEscape(name), r)
+	if err != nil {
+		return err
+	}
+	if size != -1 {
+		req.ContentLength = size
+	}
+	res, err := lc.doLocalRequestNiceError(req)
+	if err != nil {
+		return err
+	}
+	if res.StatusCode == 200 {
+		io.Copy(io.Discard, res.Body)
+		return nil
+	}
+	all, _ := io.ReadAll(res.Body)
+	return bestError(fmt.Errorf("%s: %s", res.Status, all), all)
+}
+
+// CheckIPForwarding asks the local Tailscale daemon whether it looks like the
+// machine is properly configured to forward IP packets as a subnet router
+// or exit node.
+func (lc *LocalClient) CheckIPForwarding(ctx context.Context) error {
+	body, err := lc.get200(ctx, "/localapi/v0/check-ip-forwarding")
+	if err != nil {
+		return err
+	}
+	var jres struct {
+		Warning string
+	}
+	if err := json.Unmarshal(body, &jres); err != nil {
+		return fmt.Errorf("invalid JSON from check-ip-forwarding: %w", err)
+	}
+	if jres.Warning != "" {
+		return errors.New(jres.Warning)
+	}
+	return nil
+}
+
+// CheckPrefs validates the provided preferences, without making any changes.
+//
+// The CLI uses this before a Start call to fail fast if the preferences won't
+// work. Currently (2022-04-18) this only checks for SSH server compatibility.
+// Note that EditPrefs does the same validation as this, so call CheckPrefs before
+// EditPrefs is not necessary.
+func (lc *LocalClient) CheckPrefs(ctx context.Context, p *ipn.Prefs) error {
+	pj, err := json.Marshal(p)
+	if err != nil {
+		return err
+	}
+	_, err = lc.send(ctx, "POST", "/localapi/v0/check-prefs", http.StatusOK, bytes.NewReader(pj))
+	return err
+}
+
+func (lc *LocalClient) GetPrefs(ctx context.Context) (*ipn.Prefs, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/prefs")
+	if err != nil {
+		return nil, err
+	}
+	var p ipn.Prefs
+	if err := json.Unmarshal(body, &p); err != nil {
+		return nil, fmt.Errorf("invalid prefs JSON: %w", err)
+	}
+	return &p, nil
+}
+
+func (lc *LocalClient) EditPrefs(ctx context.Context, mp *ipn.MaskedPrefs) (*ipn.Prefs, error) {
+	mpj, err := json.Marshal(mp)
+	if err != nil {
+		return nil, err
+	}
+	body, err := lc.send(ctx, "PATCH", "/localapi/v0/prefs", http.StatusOK, bytes.NewReader(mpj))
+	if err != nil {
+		return nil, err
+	}
+	var p ipn.Prefs
+	if err := json.Unmarshal(body, &p); err != nil {
+		return nil, fmt.Errorf("invalid prefs JSON: %w", err)
+	}
+	return &p, nil
+}
+
+func (lc *LocalClient) Logout(ctx context.Context) error {
+	_, err := lc.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 (lc *LocalClient) SetDNS(ctx context.Context, name, value string) error {
+	v := url.Values{}
+	v.Set("name", name)
+	v.Set("value", value)
+	_, err := lc.send(ctx, "POST", "/localapi/v0/set-dns?"+v.Encode(), 200, nil)
+	return err
+}
+
+// DialTCP connects to the host's port via Tailscale.
+//
+// The host may be a base DNS name (resolved from the netmap inside
+// tailscaled), a FQDN, or an IP address.
+//
+// The ctx is only used for the duration of the call, not the lifetime of the net.Conn.
+func (lc *LocalClient) DialTCP(ctx context.Context, host string, port uint16) (net.Conn, error) {
+	connCh := make(chan net.Conn, 1)
+	trace := httptrace.ClientTrace{
+		GotConn: func(info httptrace.GotConnInfo) {
+			connCh <- info.Conn
+		},
+	}
+	ctx = httptrace.WithClientTrace(ctx, &trace)
+	req, err := http.NewRequestWithContext(ctx, "POST", "http://local-tailscaled.sock/localapi/v0/dial", nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header = http.Header{
+		"Upgrade":    []string{"ts-dial"},
+		"Connection": []string{"upgrade"},
+		"Dial-Host":  []string{host},
+		"Dial-Port":  []string{fmt.Sprint(port)},
+	}
+	res, err := lc.DoLocalRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode != http.StatusSwitchingProtocols {
+		body, _ := io.ReadAll(res.Body)
+		res.Body.Close()
+		return nil, fmt.Errorf("unexpected HTTP response: %s, %s", res.Status, body)
+	}
+	// From here on, the underlying net.Conn is ours to use, but there
+	// is still a read buffer attached to it within resp.Body. So, we
+	// must direct I/O through resp.Body, but we can still use the
+	// underlying net.Conn for stuff like deadlines.
+	var switchedConn net.Conn
+	select {
+	case switchedConn = <-connCh:
+	default:
+	}
+	if switchedConn == nil {
+		res.Body.Close()
+		return nil, fmt.Errorf("httptrace didn't provide a connection")
+	}
+	rwc, ok := res.Body.(io.ReadWriteCloser)
+	if !ok {
+		res.Body.Close()
+		return nil, errors.New("http Transport did not provide a writable body")
+	}
+	return netutil.NewAltReadWriteCloserConn(rwc, switchedConn), nil
+}
+
+// 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 (lc *LocalClient) CurrentDERPMap(ctx context.Context) (*tailcfg.DERPMap, error) {
+	var derpMap tailcfg.DERPMap
+	res, err := lc.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.
+//
+// Deprecated: use LocalClient.CertPair.
+func CertPair(ctx context.Context, domain string) (certPEM, keyPEM []byte, err error) {
+	return defaultLocalClient.CertPair(ctx, domain)
+}
+
+// CertPair returns a cert and private key for the provided DNS domain.
+//
+// It returns a cached certificate from disk if it's still valid.
+//
+// API maturity: this is considered a stable API.
+func (lc *LocalClient) CertPair(ctx context.Context, domain string) (certPEM, keyPEM []byte, err error) {
+	res, err := lc.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.
+//
+// Deprecated: use LocalClient.GetCertificate.
+func GetCertificate(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
+	return defaultLocalClient.GetCertificate(hi)
+}
+
+// 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.
+//
+// API maturity: this is considered a stable API.
+func (lc *LocalClient) 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 := lc.ExpandSNIName(ctx, name); ok {
+			name = v
+		}
+	}
+	certPEM, keyPEM, err := lc.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.
+//
+// Deprecated: use LocalClient.ExpandSNIName.
+func ExpandSNIName(ctx context.Context, name string) (fqdn string, ok bool) {
+	return defaultLocalClient.ExpandSNIName(ctx, name)
+}
+
+// ExpandSNIName expands bare label name into the the most likely actual TLS cert name.
+func (lc *LocalClient) ExpandSNIName(ctx context.Context, name string) (fqdn string, ok bool) {
+	st, err := lc.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
+}
+
+// Ping sends a ping of the provided type to the provided IP and waits
+// for its response.
+func (lc *LocalClient) Ping(ctx context.Context, ip netip.Addr, pingtype tailcfg.PingType) (*ipnstate.PingResult, error) {
+	v := url.Values{}
+	v.Set("ip", ip.String())
+	v.Set("type", string(pingtype))
+	body, err := lc.send(ctx, "POST", "/localapi/v0/ping?"+v.Encode(), 200, nil)
+	if err != nil {
+		return nil, fmt.Errorf("error %w: %s", err, body)
+	}
+	pr := new(ipnstate.PingResult)
+	if err := json.Unmarshal(body, pr); err != nil {
+		return nil, err
+	}
+	return pr, nil
+}
+
+// NetworkLockStatus fetches information about the tailnet key authority, if one is configured.
+func (lc *LocalClient) NetworkLockStatus(ctx context.Context) (*ipnstate.NetworkLockStatus, error) {
+	body, err := lc.send(ctx, "GET", "/localapi/v0/tka/status", 200, nil)
+	if err != nil {
+		return nil, fmt.Errorf("error: %w", err)
+	}
+	pr := new(ipnstate.NetworkLockStatus)
+	if err := json.Unmarshal(body, pr); err != nil {
+		return nil, err
+	}
+	return pr, nil
+}
+
+// NetworkLockInit initializes the tailnet key authority.
+func (lc *LocalClient) NetworkLockInit(ctx context.Context, keys []tka.Key) (*ipnstate.NetworkLockStatus, error) {
+	var b bytes.Buffer
+	type initRequest struct {
+		Keys []tka.Key
+	}
+
+	if err := json.NewEncoder(&b).Encode(initRequest{Keys: keys}); err != nil {
+		return nil, err
+	}
+
+	body, err := lc.send(ctx, "POST", "/localapi/v0/tka/init", 200, &b)
+	if err != nil {
+		return nil, fmt.Errorf("error: %w", err)
+	}
+
+	pr := new(ipnstate.NetworkLockStatus)
+	if err := json.Unmarshal(body, pr); err != nil {
+		return nil, err
+	}
+	return pr, nil
+}
+
+// tailscaledConnectHint gives a little thing about why tailscaled (or
+// platform equivalent) is not answering localapi connections.
+//
+// It ends in a punctuation. See caller.
+func tailscaledConnectHint() string {
+	if runtime.GOOS != "linux" {
+		// TODO(bradfitz): flesh this out
+		return "not running?"
+	}
+	out, err := exec.Command("systemctl", "show", "tailscaled.service", "--no-page", "--property", "LoadState,ActiveState,SubState").Output()
+	if err != nil {
+		return "not running?"
+	}
+	// Parse:
+	// LoadState=loaded
+	// ActiveState=inactive
+	// SubState=dead
+	st := map[string]string{}
+	for _, line := range strings.Split(string(out), "\n") {
+		if k, v, ok := strings.Cut(line, "="); ok {
+			st[k] = strings.TrimSpace(v)
+		}
+	}
+	if st["LoadState"] == "loaded" &&
+		(st["SubState"] != "running" || st["ActiveState"] != "active") {
+		return "systemd tailscaled.service not running."
+	}
+	return "not running?"
+}

client/tailscale/required_version.go

@@ -0,0 +1,12 @@
+// Copyright (c) 2022 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 !go1.19
+// +build !go1.19
+
+package tailscale
+
+func init() {
+	you_need_Go_1_19_to_compile_Tailscale()
+}

client/tailscale/routes.go

@@ -0,0 +1,97 @@
+// Copyright (c) 2022 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 go1.19
+// +build go1.19
+
+package tailscale
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/netip"
+)
+
+// Routes contains the lists of subnet routes that are currently advertised by a device,
+// as well as the subnets that are enabled to be routed by the device.
+type Routes struct {
+	AdvertisedRoutes []netip.Prefix `json:"advertisedRoutes"`
+	EnabledRoutes    []netip.Prefix `json:"enabledRoutes"`
+}
+
+// Routes retrieves the list of subnet routes that have been enabled for a device.
+// The routes that are returned are not necessarily advertised by the device,
+// they have only been preapproved.
+func (c *Client) Routes(ctx context.Context, deviceID string) (routes *Routes, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.Routes: %w", err)
+		}
+	}()
+
+	path := fmt.Sprintf("%s/api/v2/device/%s/routes", c.baseURL(), deviceID)
+	req, err := http.NewRequestWithContext(ctx, "GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	var sr Routes
+	err = json.Unmarshal(b, &sr)
+	return &sr, err
+}
+
+type postRoutesParams struct {
+	Routes []netip.Prefix `json:"routes"`
+}
+
+// SetRoutes updates the list of subnets that are enabled for a device.
+// Subnets must be parsable by net/netip.ParsePrefix.
+// Subnets do not have to be currently advertised by a device, they may be pre-enabled.
+// Returns the updated list of enabled and advertised subnet routes in a *Routes object.
+func (c *Client) SetRoutes(ctx context.Context, deviceID string, subnets []netip.Prefix) (routes *Routes, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.SetRoutes: %w", err)
+		}
+	}()
+	params := &postRoutesParams{Routes: subnets}
+	data, err := json.Marshal(params)
+	if err != nil {
+		return nil, err
+	}
+	path := fmt.Sprintf("%s/api/v2/device/%s/routes", c.baseURL(), deviceID)
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewBuffer(data))
+	if err != nil {
+		return nil, err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	// If status code was not successful, return the error.
+	// TODO: Change the check for the StatusCode to include other 2XX success codes.
+	if resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	var srr *Routes
+	if err := json.Unmarshal(b, &srr); err != nil {
+		return nil, err
+	}
+	return srr, err
+}

client/tailscale/tailnet.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2022 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 go1.19
+// +build go1.19
+
+package tailscale
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+)
+
+// TailnetDeleteRequest handles sending a DELETE request for a tailnet to control.
+func (c *Client) TailnetDeleteRequest(ctx context.Context, tailnetID string) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("tailscale.DeleteTailnet: %w", err)
+		}
+	}()
+
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s", c.baseURL(), url.PathEscape(string(tailnetID)))
+	req, err := http.NewRequestWithContext(ctx, http.MethodDelete, path, nil)
+	if err != nil {
+		return err
+	}
+
+	c.setAuth(req)
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return handleErrorResponse(b, resp)
+	}
+
+	return nil
+}

client/tailscale/tailscale.go

@@ -1,295 +1,160 @@
-// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package tailscale contains Tailscale client code.
+//go:build go1.19
+// +build go1.19
+
+// Package tailscale contains Go clients for the Tailscale Local API and
+// Tailscale control plane API.
+//
+// Warning: this package is in development and makes no API compatibility
+// promises as of 2022-04-29. It is subject to change at any time.
 package tailscale
 
 import (
-	"bytes"
-	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
-	"net"
 	"net/http"
-	"net/url"
-	"strconv"
-	"strings"
-
-	"tailscale.com/client/tailscale/apitype"
-	"tailscale.com/ipn"
-	"tailscale.com/ipn/ipnstate"
-	"tailscale.com/paths"
-	"tailscale.com/safesocket"
-	"tailscale.com/tailcfg"
 )
 
-// TailscaledSocket is the tailscaled Unix socket.
-var TailscaledSocket = paths.DefaultTailscaledSocket()
-
-// tsClient does HTTP requests to the local Tailscale daemon.
-var tsClient = &http.Client{
-	Transport: &http.Transport{
-		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-			if addr != "local-tailscaled.sock:80" {
-				return nil, fmt.Errorf("unexpected URL address %q", addr)
-			}
-			if TailscaledSocket == paths.DefaultTailscaledSocket() {
-				// On macOS, when dialing from non-sandboxed program to sandboxed GUI running
-				// a TCP server on a random port, find the random port. For HTTP connections,
-				// we don't send the token. It gets added in an HTTP Basic-Auth header.
-				if port, _, err := safesocket.LocalTCPPortAndToken(); err == nil {
-					var d net.Dialer
-					return d.DialContext(ctx, "tcp", "localhost:"+strconv.Itoa(port))
-				}
-			}
-			return safesocket.Connect(TailscaledSocket, 41112)
-		},
-	},
-}
-
-// DoLocalRequest makes an HTTP request to the local machine's Tailscale daemon.
+// I_Acknowledge_This_API_Is_Unstable must be set true to use this package
+// for now. It was added 2022-04-29 when it was moved to this git repo
+// and will be removed when the public API has settled.
 //
-// URLs are of the form http://local-tailscaled.sock/localapi/v0/whois?ip=1.2.3.4.
+// TODO(bradfitz): remove this after the we're happy with the public API.
+var I_Acknowledge_This_API_Is_Unstable = false
+
+// TODO: use url.PathEscape() for deviceID and tailnets when constructing requests.
+
+const defaultAPIBase = "https://api.tailscale.com"
+
+// maxSize is the maximum read size (10MB) of responses from the server.
+const maxReadSize = 10 << 20
+
+// Client makes API calls to the Tailscale control plane API server.
 //
-// The hostname must be "local-tailscaled.sock", even though it
-// doesn't actually do any DNS lookup. The actual means of connecting to and
-// authenticating to the local Tailscale daemon vary by platform.
+// Use NewClient to instantiate one. Exported fields should be set before
+// the client is used and not changed thereafter.
+type Client struct {
+	// tailnet is the globally unique identifier for a Tailscale network, such
+	// as "example.com" or "user@gmail.com".
+	tailnet string
+	// auth is the authentication method to use for this client.
+	// nil means none, which generally won't work, but won't crash.
+	auth AuthMethod
+
+	// BaseURL optionally specifies an alternate API server to use.
+	// If empty, "https://api.tailscale.com" is used.
+	BaseURL string
+
+	// HTTPClient optionally specifies an alternate HTTP client to use.
+	// If nil, http.DefaultClient is used.
+	HTTPClient *http.Client
+}
+
+func (c *Client) httpClient() *http.Client {
+	if c.HTTPClient != nil {
+		return c.HTTPClient
+	}
+	return http.DefaultClient
+}
+
+func (c *Client) baseURL() string {
+	if c.BaseURL != "" {
+		return c.BaseURL
+	}
+	return defaultAPIBase
+}
+
+// AuthMethod is the interface for API authentication methods.
 //
-// DoLocalRequest may mutate the request to add Authorization headers.
-func DoLocalRequest(req *http.Request) (*http.Response, error) {
-	if _, token, err := safesocket.LocalTCPPortAndToken(); err == nil {
-		req.SetBasicAuth("", token)
+// Most users will use AuthKey.
+type AuthMethod interface {
+	modifyRequest(req *http.Request)
+}
+
+// APIKey is an AuthMethod for NewClient that authenticates requests
+// using an authkey.
+type APIKey string
+
+func (ak APIKey) modifyRequest(req *http.Request) {
+	req.SetBasicAuth(string(ak), "")
+}
+
+func (c *Client) setAuth(r *http.Request) {
+	if c.auth != nil {
+		c.auth.modifyRequest(r)
 	}
-	return tsClient.Do(req)
 }
 
-type errorJSON struct {
-	Error string
-}
-
-// bestError returns either err, or if body contains a valid JSON
-// object of type errorJSON, its non-empty error body.
-func bestError(err error, body []byte) error {
-	var j errorJSON
-	if err := json.Unmarshal(body, &j); err == nil && j.Error != "" {
-		return errors.New(j.Error)
+// NewClient is a convenience method for instantiating a new Client.
+//
+// tailnet is the globally unique identifier for a Tailscale network, such
+// as "example.com" or "user@gmail.com".
+// If httpClient is nil, then http.DefaultClient is used.
+// "api.tailscale.com" is set as the BaseURL for the returned client
+// and can be changed manually by the user.
+func NewClient(tailnet string, auth AuthMethod) *Client {
+	return &Client{
+		tailnet: tailnet,
+		auth:    auth,
 	}
-	return err
 }
 
-func send(ctx context.Context, method, path string, wantStatus int, body io.Reader) ([]byte, error) {
-	req, err := http.NewRequestWithContext(ctx, method, "http://local-tailscaled.sock"+path, body)
+func (c *Client) Tailnet() string { return c.tailnet }
+
+// Do sends a raw HTTP request, after adding any authentication headers.
+func (c *Client) Do(req *http.Request) (*http.Response, error) {
+	if !I_Acknowledge_This_API_Is_Unstable {
+		return nil, errors.New("use of Client without setting I_Acknowledge_This_API_Is_Unstable")
+	}
+	c.setAuth(req)
+	return c.httpClient().Do(req)
+}
+
+// sendRequest add the authenication key to the request and sends it. It
+// receives the response and reads up to 10MB of it.
+func (c *Client) sendRequest(req *http.Request) ([]byte, *http.Response, error) {
+	if !I_Acknowledge_This_API_Is_Unstable {
+		return nil, nil, errors.New("use of Client without setting I_Acknowledge_This_API_Is_Unstable")
+	}
+	c.setAuth(req)
+	resp, err := c.httpClient().Do(req)
 	if err != nil {
-		return nil, err
+		return nil, resp, err
 	}
-	res, err := DoLocalRequest(req)
-	if err != nil {
-		return nil, err
+	defer resp.Body.Close()
+
+	// Read response. Limit the response to 10MB.
+	body := io.LimitReader(resp.Body, maxReadSize+1)
+	b, err := ioutil.ReadAll(body)
+	if len(b) > maxReadSize {
+		err = errors.New("API response too large")
 	}
-	defer res.Body.Close()
-	slurp, err := ioutil.ReadAll(res.Body)
-	if err != nil {
-		return nil, err
-	}
-	if res.StatusCode != wantStatus {
-		err := fmt.Errorf("HTTP %s: %s (expected %v)", res.Status, slurp, wantStatus)
-		return nil, bestError(err, slurp)
-	}
-	return slurp, nil
+	return b, resp, err
 }
 
-func get200(ctx context.Context, path string) ([]byte, error) {
-	return send(ctx, "GET", path, 200, nil)
+// ErrResponse is the HTTP error returned by the Tailscale server.
+type ErrResponse struct {
+	Status  int
+	Message string
 }
 
-// WhoIs returns the owner of the remoteAddr, which must be an IP or IP:port.
-func WhoIs(ctx context.Context, remoteAddr string) (*apitype.WhoIsResponse, error) {
-	body, err := get200(ctx, "/localapi/v0/whois?addr="+url.QueryEscape(remoteAddr))
-	if err != nil {
-		return nil, err
-	}
-	r := new(apitype.WhoIsResponse)
-	if err := json.Unmarshal(body, r); err != nil {
-		if max := 200; len(body) > max {
-			body = append(body[:max], "..."...)
-		}
-		return nil, fmt.Errorf("failed to parse JSON WhoIsResponse from %q", body)
-	}
-	return r, nil
+func (e ErrResponse) Error() string {
+	return fmt.Sprintf("Status: %d, Message: %q", e.Status, e.Message)
 }
 
-// Goroutines returns a dump of the Tailscale daemon's current goroutines.
-func Goroutines(ctx context.Context) ([]byte, error) {
-	return get200(ctx, "/localapi/v0/goroutines")
-}
-
-// BugReport logs and returns a log marker that can be shared by the user with support.
-func BugReport(ctx context.Context, note string) (string, error) {
-	body, err := send(ctx, "POST", "/localapi/v0/bugreport?note="+url.QueryEscape(note), 200, nil)
-	if err != nil {
-		return "", err
-	}
-	return strings.TrimSpace(string(body)), nil
-}
-
-// Status returns the Tailscale daemon's status.
-func Status(ctx context.Context) (*ipnstate.Status, error) {
-	return status(ctx, "")
-}
-
-// StatusWithPeers returns the Tailscale daemon's status, without the peer info.
-func StatusWithoutPeers(ctx context.Context) (*ipnstate.Status, error) {
-	return status(ctx, "?peers=false")
-}
-
-func status(ctx context.Context, queryString string) (*ipnstate.Status, error) {
-	body, err := get200(ctx, "/localapi/v0/status"+queryString)
-	if err != nil {
-		return nil, err
-	}
-	st := new(ipnstate.Status)
-	if err := json.Unmarshal(body, st); err != nil {
-		return nil, err
-	}
-	return st, nil
-}
-
-func WaitingFiles(ctx context.Context) ([]apitype.WaitingFile, error) {
-	body, err := get200(ctx, "/localapi/v0/files/")
-	if err != nil {
-		return nil, err
-	}
-	var wfs []apitype.WaitingFile
-	if err := json.Unmarshal(body, &wfs); err != nil {
-		return nil, err
-	}
-	return wfs, nil
-}
-
-func DeleteWaitingFile(ctx context.Context, baseName string) error {
-	_, err := send(ctx, "DELETE", "/localapi/v0/files/"+url.PathEscape(baseName), http.StatusNoContent, nil)
-	return err
-}
-
-func GetWaitingFile(ctx context.Context, baseName string) (rc io.ReadCloser, size int64, err error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/files/"+url.PathEscape(baseName), nil)
-	if err != nil {
-		return nil, 0, err
-	}
-	res, err := DoLocalRequest(req)
-	if err != nil {
-		return nil, 0, err
-	}
-	if res.ContentLength == -1 {
-		res.Body.Close()
-		return nil, 0, fmt.Errorf("unexpected chunking")
-	}
-	if res.StatusCode != 200 {
-		body, _ := ioutil.ReadAll(res.Body)
-		res.Body.Close()
-		return nil, 0, fmt.Errorf("HTTP %s: %s", res.Status, body)
-	}
-	return res.Body, res.ContentLength, nil
-}
-
-func FileTargets(ctx context.Context) ([]apitype.FileTarget, error) {
-	body, err := get200(ctx, "/localapi/v0/file-targets")
-	if err != nil {
-		return nil, err
-	}
-	var fts []apitype.FileTarget
-	if err := json.Unmarshal(body, &fts); err != nil {
-		return nil, fmt.Errorf("invalid JSON: %w", err)
-	}
-	return fts, nil
-}
-
-func CheckIPForwarding(ctx context.Context) error {
-	body, err := get200(ctx, "/localapi/v0/check-ip-forwarding")
-	if err != nil {
+// handleErrorResponse decodes the error message from the server and returns
+// an ErrResponse from it.
+func handleErrorResponse(b []byte, resp *http.Response) error {
+	var errResp ErrResponse
+	if err := json.Unmarshal(b, &errResp); err != nil {
 		return err
 	}
-	var jres struct {
-		Warning string
-	}
-	if err := json.Unmarshal(body, &jres); err != nil {
-		return fmt.Errorf("invalid JSON from check-ip-forwarding: %w", err)
-	}
-	if jres.Warning != "" {
-		return errors.New(jres.Warning)
-	}
-	return nil
-}
-
-func GetPrefs(ctx context.Context) (*ipn.Prefs, error) {
-	body, err := get200(ctx, "/localapi/v0/prefs")
-	if err != nil {
-		return nil, err
-	}
-	var p ipn.Prefs
-	if err := json.Unmarshal(body, &p); err != nil {
-		return nil, fmt.Errorf("invalid prefs JSON: %w", err)
-	}
-	return &p, nil
-}
-
-func EditPrefs(ctx context.Context, mp *ipn.MaskedPrefs) (*ipn.Prefs, error) {
-	mpj, err := json.Marshal(mp)
-	if err != nil {
-		return nil, err
-	}
-	body, err := send(ctx, "PATCH", "/localapi/v0/prefs", http.StatusOK, bytes.NewReader(mpj))
-	if err != nil {
-		return nil, err
-	}
-	var p ipn.Prefs
-	if err := json.Unmarshal(body, &p); err != nil {
-		return nil, fmt.Errorf("invalid prefs JSON: %w", err)
-	}
-	return &p, nil
-}
-
-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
+	errResp.Status = resp.StatusCode
+	return errResp
 }

cmd/cloner/cloner.go

@@ -17,21 +17,16 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"go/ast"
-	"go/format"
-	"go/token"
 	"go/types"
-	"io/ioutil"
 	"log"
 	"os"
 	"strings"
 
-	"golang.org/x/tools/go/packages"
+	"tailscale.com/util/codegen"
 )
 
 var (
 	flagTypes     = flag.String("type", "", "comma-separated list of types; required")
-	flagOutput    = flag.String("output", "", "output file; required")
 	flagBuildTags = flag.String("tags", "", "compiler build tags to apply")
 	flagCloneFunc = flag.Bool("clonefunc", false, "add a top-level Clone func")
 )
@@ -46,64 +41,28 @@ func main() {
 	}
 	typeNames := strings.Split(*flagTypes, ",")
 
-	cfg := &packages.Config{
-		Mode:  packages.NeedTypes | packages.NeedTypesInfo | packages.NeedSyntax | packages.NeedName,
-		Tests: false,
-	}
-	if *flagBuildTags != "" {
-		cfg.BuildFlags = []string{"-tags=" + *flagBuildTags}
-	}
-	pkgs, err := packages.Load(cfg, ".")
+	pkg, namedTypes, err := codegen.LoadTypes(*flagBuildTags, ".")
 	if err != nil {
 		log.Fatal(err)
 	}
-	if len(pkgs) != 1 {
-		log.Fatalf("wrong number of packages: %d", len(pkgs))
-	}
-	pkg := pkgs[0]
+	it := codegen.NewImportTracker(pkg.Types)
 	buf := new(bytes.Buffer)
-	imports := make(map[string]struct{})
 	for _, typeName := range typeNames {
-		found := false
-		for _, file := range pkg.Syntax {
-			//var fbuf bytes.Buffer
-			//ast.Fprint(&fbuf, pkg.Fset, file, nil)
-			//fmt.Println(fbuf.String())
-
-			for _, d := range file.Decls {
-				decl, ok := d.(*ast.GenDecl)
-				if !ok || decl.Tok != token.TYPE {
-					continue
-				}
-				for _, s := range decl.Specs {
-					spec, ok := s.(*ast.TypeSpec)
-					if !ok || spec.Name.Name != typeName {
-						continue
-					}
-					typeNameObj := pkg.TypesInfo.Defs[spec.Name]
-					typ, ok := typeNameObj.Type().(*types.Named)
-					if !ok {
-						continue
-					}
-					pkg := typeNameObj.Pkg()
-					gen(buf, imports, typeName, typ, pkg)
-					found = true
-				}
-			}
-		}
-		if !found {
+		typ, ok := namedTypes[typeName]
+		if !ok {
 			log.Fatalf("could not find type %s", typeName)
 		}
+		gen(buf, it, typ)
 	}
 
-	w := func(format string, args ...interface{}) {
+	w := func(format string, args ...any) {
 		fmt.Fprintf(buf, format+"\n", args...)
 	}
 	if *flagCloneFunc {
 		w("// Clone duplicates src into dst and reports whether it succeeded.")
 		w("// To succeed, <src, dst> must be of types <*T, *T> or <*T, **T>,")
 		w("// where T is one of %s.", *flagTypes)
-		w("func Clone(dst, src interface{}) bool {")
+		w("func Clone(dst, src any) bool {")
 		w("	switch src := src.(type) {")
 		for _, typeName := range typeNames {
 			w("	case *%s:", typeName)
@@ -120,156 +79,117 @@ func main() {
 		w("	return false")
 		w("}")
 	}
-
-	contents := new(bytes.Buffer)
-	fmt.Fprintf(contents, header, *flagTypes, pkg.Name)
-	fmt.Fprintf(contents, "import (\n")
-	for s := range imports {
-		fmt.Fprintf(contents, "\t%q\n", s)
-	}
-	fmt.Fprintf(contents, ")\n\n")
-	contents.Write(buf.Bytes())
-
-	out, err := format.Source(contents.Bytes())
-	if err != nil {
-		log.Fatalf("%s, in source:\n%s", err, contents.Bytes())
-	}
-
-	output := *flagOutput
-	if output == "" {
-		flag.Usage()
-		os.Exit(2)
-	}
-	if err := ioutil.WriteFile(output, out, 0644); err != nil {
+	cloneOutput := pkg.Name + "_clone.go"
+	if err := codegen.WritePackageFile("tailscale.com/cmd/cloner", pkg, cloneOutput, it, buf); err != nil {
 		log.Fatal(err)
 	}
 }
 
-const header = `// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Code generated by tailscale.com/cmd/cloner -type %s; DO NOT EDIT.
-
-package %s
-
-`
-
-func gen(buf *bytes.Buffer, imports map[string]struct{}, name string, typ *types.Named, thisPkg *types.Package) {
-	pkgQual := func(pkg *types.Package) string {
-		if thisPkg == pkg {
-			return ""
-		}
-		imports[pkg.Path()] = struct{}{}
-		return pkg.Name()
-	}
-	importedName := func(t types.Type) string {
-		return types.TypeString(t, pkgQual)
+func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
+	t, ok := typ.Underlying().(*types.Struct)
+	if !ok {
+		return
 	}
 
-	switch t := typ.Underlying().(type) {
-	case *types.Struct:
-		// We generate two bits of code simultaneously while we walk the struct.
-		// One is the Clone method itself, which we write directly to buf.
-		// The other is a variable assignment that will fail if the struct
-		// changes without the Clone method getting regenerated.
-		// We write that to regenBuf, and then append it to buf at the end.
-		regenBuf := new(bytes.Buffer)
-		writeRegen := func(format string, args ...interface{}) {
-			fmt.Fprintf(regenBuf, format+"\n", args...)
+	name := typ.Obj().Name()
+	fmt.Fprintf(buf, "// Clone makes a deep copy of %s.\n", name)
+	fmt.Fprintf(buf, "// The result aliases no memory with the original.\n")
+	fmt.Fprintf(buf, "func (src *%s) Clone() *%s {\n", name, name)
+	writef := func(format string, args ...any) {
+		fmt.Fprintf(buf, "\t"+format+"\n", args...)
+	}
+	writef("if src == nil {")
+	writef("\treturn nil")
+	writef("}")
+	writef("dst := new(%s)", name)
+	writef("*dst = *src")
+	for i := 0; i < t.NumFields(); i++ {
+		fname := t.Field(i).Name()
+		ft := t.Field(i).Type()
+		if !codegen.ContainsPointers(ft) || codegen.HasNoClone(t.Tag(i)) {
+			continue
 		}
-		writeRegen("// A compilation failure here means this code must be regenerated, with command:")
-		writeRegen("//   tailscale.com/cmd/cloner -type %s", *flagTypes)
-		writeRegen("var _%sNeedsRegeneration = %s(struct {", name, name)
-
-		name := typ.Obj().Name()
-		fmt.Fprintf(buf, "// Clone makes a deep copy of %s.\n", name)
-		fmt.Fprintf(buf, "// The result aliases no memory with the original.\n")
-		fmt.Fprintf(buf, "func (src *%s) Clone() *%s {\n", name, name)
-		writef := func(format string, args ...interface{}) {
-			fmt.Fprintf(buf, "\t"+format+"\n", args...)
-		}
-		writef("if src == nil {")
-		writef("\treturn nil")
-		writef("}")
-		writef("dst := new(%s)", name)
-		writef("*dst = *src")
-		for i := 0; i < t.NumFields(); i++ {
-			fname := t.Field(i).Name()
-			ft := t.Field(i).Type()
-
-			writeRegen("\t%s %s", fname, importedName(ft))
-
-			if !containsPointers(ft) {
+		if named, _ := ft.(*types.Named); named != nil {
+			if codegen.IsViewType(ft) {
+				writef("dst.%s = src.%s", fname, fname)
 				continue
 			}
-			if named, _ := ft.(*types.Named); named != nil && !hasBasicUnderlying(ft) {
+			if !hasBasicUnderlying(ft) {
 				writef("dst.%s = *src.%s.Clone()", fname, fname)
 				continue
 			}
-			switch ft := ft.Underlying().(type) {
-			case *types.Slice:
-				if containsPointers(ft.Elem()) {
-					n := importedName(ft.Elem())
-					writef("dst.%s = make([]%s, len(src.%s))", fname, n, fname)
-					writef("for i := range dst.%s {", fname)
-					if _, isPtr := ft.Elem().(*types.Pointer); isPtr {
-						writef("\tdst.%s[i] = src.%s[i].Clone()", fname, fname)
-					} else {
-						writef("\tdst.%s[i] = *src.%s[i].Clone()", fname, fname)
-					}
-					writef("}")
-				} else {
-					writef("dst.%s = append(src.%s[:0:0], src.%s...)", fname, fname, fname)
-				}
-			case *types.Pointer:
-				if named, _ := ft.Elem().(*types.Named); named != nil && containsPointers(ft.Elem()) {
-					writef("dst.%s = src.%s.Clone()", fname, fname)
-					continue
-				}
-				n := importedName(ft.Elem())
-				writef("if dst.%s != nil {", fname)
-				writef("\tdst.%s = new(%s)", fname, n)
-				writef("\t*dst.%s = *src.%s", fname, fname)
-				if containsPointers(ft.Elem()) {
-					writef("\t" + `panic("TODO pointers in pointers")`)
-				}
-				writef("}")
-			case *types.Map:
-				writef("if dst.%s != nil {", fname)
-				writef("\tdst.%s = map[%s]%s{}", fname, importedName(ft.Key()), importedName(ft.Elem()))
-				if sliceType, isSlice := ft.Elem().(*types.Slice); isSlice {
-					n := importedName(sliceType.Elem())
-					writef("\tfor k := range src.%s {", fname)
-					// use zero-length slice instead of nil to ensure
-					// the key is always copied.
-					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}")
-				} else {
-					writef("\tfor k, v := range src.%s {", fname)
-					writef("\t\tdst.%s[k] = v", fname)
-					writef("\t}")
-				}
-				writef("}")
-			case *types.Struct:
-				writef(`panic("TODO struct %s")`, fname)
-			default:
-				writef(`panic(fmt.Sprintf("TODO: %T", ft))`)
-			}
 		}
-		writef("return dst")
-		fmt.Fprintf(buf, "}\n\n")
-
-		writeRegen("}{})\n")
-
-		buf.Write(regenBuf.Bytes())
+		switch ft := ft.Underlying().(type) {
+		case *types.Slice:
+			if codegen.ContainsPointers(ft.Elem()) {
+				n := it.QualifiedName(ft.Elem())
+				writef("dst.%s = make([]%s, len(src.%s))", fname, n, fname)
+				writef("for i := range dst.%s {", fname)
+				if ptr, isPtr := ft.Elem().(*types.Pointer); isPtr {
+					if _, isBasic := ptr.Elem().Underlying().(*types.Basic); isBasic {
+						writef("\tx := *src.%s[i]", fname)
+						writef("\tdst.%s[i] = &x", fname)
+					} else {
+						writef("\tdst.%s[i] = src.%s[i].Clone()", fname, fname)
+					}
+				} else {
+					writef("\tdst.%s[i] = *src.%s[i].Clone()", fname, fname)
+				}
+				writef("}")
+			} else {
+				writef("dst.%s = append(src.%s[:0:0], src.%s...)", fname, fname, fname)
+			}
+		case *types.Pointer:
+			if named, _ := ft.Elem().(*types.Named); named != nil && codegen.ContainsPointers(ft.Elem()) {
+				writef("dst.%s = src.%s.Clone()", fname, fname)
+				continue
+			}
+			n := it.QualifiedName(ft.Elem())
+			writef("if dst.%s != nil {", fname)
+			writef("\tdst.%s = new(%s)", fname, n)
+			writef("\t*dst.%s = *src.%s", fname, fname)
+			if codegen.ContainsPointers(ft.Elem()) {
+				writef("\t" + `panic("TODO pointers in pointers")`)
+			}
+			writef("}")
+		case *types.Map:
+			elem := ft.Elem()
+			writef("if dst.%s != nil {", fname)
+			writef("\tdst.%s = map[%s]%s{}", fname, it.QualifiedName(ft.Key()), it.QualifiedName(elem))
+			if sliceType, isSlice := elem.(*types.Slice); isSlice {
+				n := it.QualifiedName(sliceType.Elem())
+				writef("\tfor k := range src.%s {", fname)
+				// use zero-length slice instead of nil to ensure
+				// the key is always copied.
+				writef("\t\tdst.%s[k] = append([]%s{}, src.%s[k]...)", fname, n, fname)
+				writef("\t}")
+			} else if codegen.ContainsPointers(elem) {
+				writef("\tfor k, v := range src.%s {", fname)
+				switch elem.(type) {
+				case *types.Pointer:
+					writef("\t\tdst.%s[k] = v.Clone()", fname)
+				default:
+					writef("\t\tv2 := v.Clone()")
+					writef("\t\tdst.%s[k] = *v2", fname)
+				}
+				writef("\t}")
+			} else {
+				writef("\tfor k, v := range src.%s {", fname)
+				writef("\t\tdst.%s[k] = v", fname)
+				writef("\t}")
+			}
+			writef("}")
+		default:
+			writef(`panic("TODO: %s (%T)")`, fname, ft)
+		}
 	}
+	writef("return dst")
+	fmt.Fprintf(buf, "}\n\n")
+
+	buf.Write(codegen.AssertStructUnchanged(t, name, "Clone", it))
 }
 
+// hasBasicUnderlying reports true when typ.Underlying() is a slice or a map.
 func hasBasicUnderlying(typ types.Type) bool {
 	switch typ.Underlying().(type) {
 	case *types.Slice, *types.Map:
@@ -278,34 +198,3 @@ func hasBasicUnderlying(typ types.Type) bool {
 		return false
 	}
 }
-
-func containsPointers(typ types.Type) bool {
-	switch typ.String() {
-	case "time.Time":
-		// time.Time contains a pointer that does not need copying
-		return false
-	case "inet.af/netaddr.IP":
-		return false
-	}
-	switch ft := typ.Underlying().(type) {
-	case *types.Array:
-		return containsPointers(ft.Elem())
-	case *types.Chan:
-		return true
-	case *types.Interface:
-		return true // a little too broad
-	case *types.Map:
-		return true
-	case *types.Pointer:
-		return true
-	case *types.Slice:
-		return true
-	case *types.Struct:
-		for i := 0; i < ft.NumFields(); i++ {
-			if containsPointers(ft.Field(i).Type()) {
-				return true
-			}
-		}
-	}
-	return false
-}

cmd/derper/bootstrap_dns.go

@@ -12,23 +12,36 @@ import (
 	"net"
 	"net/http"
 	"strings"
-	"sync"
 	"time"
+
+	"tailscale.com/syncs"
+)
+
+const refreshTimeout = time.Minute
+
+type dnsEntryMap map[string][]net.IP
+
+var (
+	dnsCache            syncs.AtomicValue[dnsEntryMap]
+	dnsCacheBytes       syncs.AtomicValue[[]byte] // of JSON
+	unpublishedDNSCache syncs.AtomicValue[dnsEntryMap]
 )
 
 var (
-	dnsMu    sync.Mutex
-	dnsCache = map[string][]net.IP{}
+	bootstrapDNSRequests = expvar.NewInt("counter_bootstrap_dns_requests")
+	publishedDNSHits     = expvar.NewInt("counter_bootstrap_dns_published_hits")
+	publishedDNSMisses   = expvar.NewInt("counter_bootstrap_dns_published_misses")
+	unpublishedDNSHits   = expvar.NewInt("counter_bootstrap_dns_unpublished_hits")
+	unpublishedDNSMisses = expvar.NewInt("counter_bootstrap_dns_unpublished_misses")
 )
 
-var bootstrapDNSRequests = expvar.NewInt("counter_bootstrap_dns_requests")
-
 func refreshBootstrapDNSLoop() {
-	if *bootstrapDNS == "" {
+	if *bootstrapDNS == "" && *unpublishedDNS == "" {
 		return
 	}
 	for {
 		refreshBootstrapDNS()
+		refreshUnpublishedDNS()
 		time.Sleep(10 * time.Minute)
 	}
 }
@@ -37,9 +50,34 @@ func refreshBootstrapDNS() {
 	if *bootstrapDNS == "" {
 		return
 	}
-	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	ctx, cancel := context.WithTimeout(context.Background(), refreshTimeout)
 	defer cancel()
-	names := strings.Split(*bootstrapDNS, ",")
+	dnsEntries := resolveList(ctx, strings.Split(*bootstrapDNS, ","))
+	j, err := json.MarshalIndent(dnsEntries, "", "\t")
+	if err != nil {
+		// leave the old values in place
+		return
+	}
+
+	dnsCache.Store(dnsEntries)
+	dnsCacheBytes.Store(j)
+}
+
+func refreshUnpublishedDNS() {
+	if *unpublishedDNS == "" {
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), refreshTimeout)
+	defer cancel()
+
+	dnsEntries := resolveList(ctx, strings.Split(*unpublishedDNS, ","))
+	unpublishedDNSCache.Store(dnsEntries)
+}
+
+func resolveList(ctx context.Context, names []string) dnsEntryMap {
+	dnsEntries := make(dnsEntryMap)
+
 	var r net.Resolver
 	for _, name := range names {
 		addrs, err := r.LookupIP(ctx, "ip", name)
@@ -47,23 +85,49 @@ func refreshBootstrapDNS() {
 			log.Printf("bootstrap DNS lookup %q: %v", name, err)
 			continue
 		}
-		dnsMu.Lock()
-		dnsCache[name] = addrs
-		dnsMu.Unlock()
+		dnsEntries[name] = addrs
 	}
+	return dnsEntries
 }
 
 func handleBootstrapDNS(w http.ResponseWriter, r *http.Request) {
 	bootstrapDNSRequests.Add(1)
-	dnsMu.Lock()
-	j, err := json.MarshalIndent(dnsCache, "", "\t")
-	dnsMu.Unlock()
-	if err != nil {
-		log.Printf("bootstrap DNS JSON: %v", err)
-		http.Error(w, "JSON marshal error", 500)
-		return
-	}
 
 	w.Header().Set("Content-Type", "application/json")
+	// Bootstrap DNS requests occur cross-regions, and are randomized per
+	// request, so keeping a connection open is pointlessly expensive.
+	w.Header().Set("Connection", "close")
+
+	// Try answering a query from our hidden map first
+	if q := r.URL.Query().Get("q"); q != "" {
+		if ips, ok := unpublishedDNSCache.Load()[q]; ok && len(ips) > 0 {
+			unpublishedDNSHits.Add(1)
+
+			// Only return the specific query, not everything.
+			m := dnsEntryMap{q: ips}
+			j, err := json.MarshalIndent(m, "", "\t")
+			if err == nil {
+				w.Write(j)
+				return
+			}
+		}
+
+		// If we have a "q" query for a name in the published cache
+		// list, then track whether that's a hit/miss.
+		if m, ok := dnsCache.Load()[q]; ok {
+			if len(m) > 0 {
+				publishedDNSHits.Add(1)
+			} else {
+				publishedDNSMisses.Add(1)
+			}
+		} else {
+			// If it wasn't in either cache, treat this as a query
+			// for the unpublished cache, and thus a cache miss.
+			unpublishedDNSMisses.Add(1)
+		}
+	}
+
+	// Fall back to returning the public set of cached DNS names
+	j := dnsCacheBytes.Load()
 	w.Write(j)
 }

cmd/derper/bootstrap_dns_test.go

@@ -0,0 +1,154 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"encoding/json"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"reflect"
+	"testing"
+)
+
+func BenchmarkHandleBootstrapDNS(b *testing.B) {
+	prev := *bootstrapDNS
+	*bootstrapDNS = "log.tailscale.io,login.tailscale.com,controlplane.tailscale.com,login.us.tailscale.com"
+	defer func() {
+		*bootstrapDNS = prev
+	}()
+	refreshBootstrapDNS()
+	w := new(bitbucketResponseWriter)
+	req, _ := http.NewRequest("GET", "https://localhost/bootstrap-dns?q="+url.QueryEscape("log.tailscale.io"), nil)
+	b.ReportAllocs()
+	b.ResetTimer()
+	b.RunParallel(func(b *testing.PB) {
+		for b.Next() {
+			handleBootstrapDNS(w, req)
+		}
+	})
+}
+
+type bitbucketResponseWriter struct{}
+
+func (b *bitbucketResponseWriter) Header() http.Header { return make(http.Header) }
+
+func (b *bitbucketResponseWriter) Write(p []byte) (int, error) { return len(p), nil }
+
+func (b *bitbucketResponseWriter) WriteHeader(statusCode int) {}
+
+func getBootstrapDNS(t *testing.T, q string) dnsEntryMap {
+	t.Helper()
+	req, _ := http.NewRequest("GET", "https://localhost/bootstrap-dns?q="+url.QueryEscape(q), nil)
+	w := httptest.NewRecorder()
+	handleBootstrapDNS(w, req)
+
+	res := w.Result()
+	if res.StatusCode != 200 {
+		t.Fatalf("got status=%d; want %d", res.StatusCode, 200)
+	}
+	var ips dnsEntryMap
+	if err := json.NewDecoder(res.Body).Decode(&ips); err != nil {
+		t.Fatalf("error decoding response body: %v", err)
+	}
+	return ips
+}
+
+func TestUnpublishedDNS(t *testing.T) {
+	const published = "login.tailscale.com"
+	const unpublished = "log.tailscale.io"
+
+	prev1, prev2 := *bootstrapDNS, *unpublishedDNS
+	*bootstrapDNS = published
+	*unpublishedDNS = unpublished
+	t.Cleanup(func() {
+		*bootstrapDNS = prev1
+		*unpublishedDNS = prev2
+	})
+
+	refreshBootstrapDNS()
+	refreshUnpublishedDNS()
+
+	hasResponse := func(q string) bool {
+		_, found := getBootstrapDNS(t, q)[q]
+		return found
+	}
+
+	if !hasResponse(published) {
+		t.Errorf("expected response for: %s", published)
+	}
+	if !hasResponse(unpublished) {
+		t.Errorf("expected response for: %s", unpublished)
+	}
+
+	// Verify that querying for a random query or a real query does not
+	// leak our unpublished domain
+	m1 := getBootstrapDNS(t, published)
+	if _, found := m1[unpublished]; found {
+		t.Errorf("found unpublished domain %s: %+v", unpublished, m1)
+	}
+	m2 := getBootstrapDNS(t, "random.example.com")
+	if _, found := m2[unpublished]; found {
+		t.Errorf("found unpublished domain %s: %+v", unpublished, m2)
+	}
+}
+
+func resetMetrics() {
+	publishedDNSHits.Set(0)
+	publishedDNSMisses.Set(0)
+	unpublishedDNSHits.Set(0)
+	unpublishedDNSMisses.Set(0)
+}
+
+// Verify that we don't count an empty list in the unpublishedDNSCache as a
+// cache hit in our metrics.
+func TestUnpublishedDNSEmptyList(t *testing.T) {
+	pub := dnsEntryMap{
+		"tailscale.com": {net.IPv4(10, 10, 10, 10)},
+	}
+	dnsCache.Store(pub)
+	dnsCacheBytes.Store([]byte(`{"tailscale.com":["10.10.10.10"]}`))
+
+	unpublishedDNSCache.Store(dnsEntryMap{
+		"log.tailscale.io":           {},
+		"controlplane.tailscale.com": {net.IPv4(1, 2, 3, 4)},
+	})
+
+	t.Run("CacheMiss", func(t *testing.T) {
+		// One domain in map but empty, one not in map at all
+		for _, q := range []string{"log.tailscale.io", "login.tailscale.com"} {
+			resetMetrics()
+			ips := getBootstrapDNS(t, q)
+
+			// Expected our public map to be returned on a cache miss
+			if !reflect.DeepEqual(ips, pub) {
+				t.Errorf("got ips=%+v; want %+v", ips, pub)
+			}
+			if v := unpublishedDNSHits.Value(); v != 0 {
+				t.Errorf("got hits=%d; want 0", v)
+			}
+			if v := unpublishedDNSMisses.Value(); v != 1 {
+				t.Errorf("got misses=%d; want 1", v)
+			}
+		}
+	})
+
+	// Verify that we do get a valid response and metric.
+	t.Run("CacheHit", func(t *testing.T) {
+		resetMetrics()
+		ips := getBootstrapDNS(t, "controlplane.tailscale.com")
+		want := dnsEntryMap{"controlplane.tailscale.com": {net.IPv4(1, 2, 3, 4)}}
+		if !reflect.DeepEqual(ips, want) {
+			t.Errorf("got ips=%+v; want %+v", ips, want)
+		}
+		if v := unpublishedDNSHits.Value(); v != 1 {
+			t.Errorf("got hits=%d; want 1", v)
+		}
+		if v := unpublishedDNSMisses.Value(); v != 0 {
+			t.Errorf("got misses=%d; want 0", v)
+		}
+	})
+}

cmd/derper/cert.go

@@ -0,0 +1,106 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"net/http"
+	"path/filepath"
+	"regexp"
+
+	"golang.org/x/crypto/acme/autocert"
+)
+
+var unsafeHostnameCharacters = regexp.MustCompile(`[^a-zA-Z0-9-\.]`)
+
+type certProvider interface {
+	// TLSConfig creates a new TLS config suitable for net/http.Server servers.
+	//
+	// The returned Config must have a GetCertificate function set and that
+	// function must return a unique *tls.Certificate for each call. The
+	// returned *tls.Certificate will be mutated by the caller to append to the
+	// (*tls.Certificate).Certificate field.
+	TLSConfig() *tls.Config
+	// HTTPHandler handle ACME related request, if any.
+	HTTPHandler(fallback http.Handler) http.Handler
+}
+
+func certProviderByCertMode(mode, dir, hostname string) (certProvider, error) {
+	if dir == "" {
+		return nil, errors.New("missing required --certdir flag")
+	}
+	switch mode {
+	case "letsencrypt":
+		certManager := &autocert.Manager{
+			Prompt:     autocert.AcceptTOS,
+			HostPolicy: autocert.HostWhitelist(hostname),
+			Cache:      autocert.DirCache(dir),
+		}
+		if hostname == "derp.tailscale.com" {
+			certManager.HostPolicy = prodAutocertHostPolicy
+			certManager.Email = "security@tailscale.com"
+		}
+		return certManager, nil
+	case "manual":
+		return NewManualCertManager(dir, hostname)
+	default:
+		return nil, fmt.Errorf("unsupport cert mode: %q", mode)
+	}
+}
+
+type manualCertManager struct {
+	cert     *tls.Certificate
+	hostname string
+}
+
+// NewManualCertManager returns a cert provider which read certificate by given hostname on create.
+func NewManualCertManager(certdir, hostname string) (certProvider, error) {
+	keyname := unsafeHostnameCharacters.ReplaceAllString(hostname, "")
+	crtPath := filepath.Join(certdir, keyname+".crt")
+	keyPath := filepath.Join(certdir, keyname+".key")
+	cert, err := tls.LoadX509KeyPair(crtPath, keyPath)
+	if err != nil {
+		return nil, fmt.Errorf("can not load x509 key pair for hostname %q: %w", keyname, err)
+	}
+	// ensure hostname matches with the certificate
+	x509Cert, err := x509.ParseCertificate(cert.Certificate[0])
+	if err != nil {
+		return nil, fmt.Errorf("can not load cert: %w", err)
+	}
+	if err := x509Cert.VerifyHostname(hostname); err != nil {
+		return nil, fmt.Errorf("cert invalid for hostname %q: %w", hostname, err)
+	}
+	return &manualCertManager{cert: &cert, hostname: hostname}, nil
+}
+
+func (m *manualCertManager) TLSConfig() *tls.Config {
+	return &tls.Config{
+		Certificates: nil,
+		NextProtos: []string{
+			"h2", "http/1.1", // enable HTTP/2
+		},
+		GetCertificate: m.getCertificate,
+	}
+}
+
+func (m *manualCertManager) getCertificate(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
+	if hi.ServerName != m.hostname {
+		return nil, fmt.Errorf("cert mismatch with hostname: %q", hi.ServerName)
+	}
+
+	// Return a shallow copy of the cert so the caller can append to its
+	// Certificate field.
+	certCopy := new(tls.Certificate)
+	*certCopy = *m.cert
+	certCopy.Certificate = certCopy.Certificate[:len(certCopy.Certificate):len(certCopy.Certificate)]
+	return certCopy, nil
+}
+
+func (m *manualCertManager) HTTPHandler(fallback http.Handler) http.Handler {
+	return fallback
+}

cmd/derper/depaware.txt

@@ -0,0 +1,197 @@
+tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depaware)
+
+        filippo.io/edwards25519                                      from github.com/hdevalence/ed25519consensus
+        filippo.io/edwards25519/field                                from filippo.io/edwards25519
+   W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/internal/common+
+   W    github.com/alexbrainman/sspi/internal/common                 from github.com/alexbrainman/sspi/negotiate
+   W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
+        github.com/fxamacker/cbor/v2                                 from tailscale.com/tka
+        github.com/golang/groupcache/lru                             from tailscale.com/net/dnscache
+        github.com/hdevalence/ed25519consensus                       from tailscale.com/tka
+   L    github.com/josharian/native                                  from github.com/mdlayher/netlink+
+   L 💣 github.com/jsimonetti/rtnetlink                              from tailscale.com/net/interfaces
+   L    github.com/jsimonetti/rtnetlink/internal/unix                from github.com/jsimonetti/rtnetlink
+        github.com/klauspost/compress/flate                          from nhooyr.io/websocket
+   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/socket                                   from github.com/mdlayher/netlink
+     💣 github.com/mitchellh/go-ps                                   from tailscale.com/safesocket
+        github.com/x448/float16                                      from github.com/fxamacker/cbor/v2
+     💣 go4.org/mem                                                  from tailscale.com/client/tailscale+
+        go4.org/netipx                                               from tailscale.com/wgengine/filter
+   W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
+        nhooyr.io/websocket                                          from tailscale.com/cmd/derper+
+        nhooyr.io/websocket/internal/errd                            from nhooyr.io/websocket
+        nhooyr.io/websocket/internal/xsync                           from nhooyr.io/websocket
+        tailscale.com                                                from tailscale.com/version
+        tailscale.com/atomicfile                                     from tailscale.com/cmd/derper+
+        tailscale.com/client/tailscale                               from tailscale.com/derp
+        tailscale.com/client/tailscale/apitype                       from tailscale.com/client/tailscale
+        tailscale.com/derp                                           from tailscale.com/cmd/derper+
+        tailscale.com/derp/derphttp                                  from tailscale.com/cmd/derper
+        tailscale.com/disco                                          from tailscale.com/derp
+        tailscale.com/envknob                                        from tailscale.com/derp+
+        tailscale.com/hostinfo                                       from tailscale.com/net/interfaces+
+        tailscale.com/ipn                                            from tailscale.com/client/tailscale
+        tailscale.com/ipn/ipnstate                                   from tailscale.com/client/tailscale+
+     💣 tailscale.com/metrics                                        from tailscale.com/cmd/derper+
+        tailscale.com/net/dnscache                                   from tailscale.com/derp/derphttp
+        tailscale.com/net/flowtrack                                  from tailscale.com/net/packet+
+     💣 tailscale.com/net/interfaces                                 from tailscale.com/net/netns+
+        tailscale.com/net/netaddr                                    from tailscale.com/ipn+
+        tailscale.com/net/netknob                                    from tailscale.com/net/netns
+        tailscale.com/net/netns                                      from tailscale.com/derp/derphttp
+        tailscale.com/net/netutil                                    from tailscale.com/client/tailscale
+        tailscale.com/net/packet                                     from tailscale.com/wgengine/filter
+        tailscale.com/net/stun                                       from tailscale.com/cmd/derper
+        tailscale.com/net/tlsdial                                    from tailscale.com/derp/derphttp
+        tailscale.com/net/tsaddr                                     from tailscale.com/ipn+
+     💣 tailscale.com/net/tshttpproxy                                from tailscale.com/derp/derphttp+
+        tailscale.com/paths                                          from tailscale.com/client/tailscale
+        tailscale.com/safesocket                                     from tailscale.com/client/tailscale
+        tailscale.com/syncs                                          from tailscale.com/cmd/derper+
+        tailscale.com/tailcfg                                        from tailscale.com/client/tailscale+
+        tailscale.com/tka                                            from tailscale.com/client/tailscale
+   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/tsweb                                          from tailscale.com/cmd/derper
+        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/cmd/derper+
+        tailscale.com/types/logger                                   from tailscale.com/cmd/derper+
+        tailscale.com/types/netmap                                   from tailscale.com/ipn
+        tailscale.com/types/opt                                      from tailscale.com/client/tailscale+
+        tailscale.com/types/pad32                                    from tailscale.com/derp
+        tailscale.com/types/persist                                  from tailscale.com/ipn
+        tailscale.com/types/preftype                                 from tailscale.com/ipn
+        tailscale.com/types/structs                                  from tailscale.com/ipn+
+        tailscale.com/types/tkatype                                  from tailscale.com/types/key+
+        tailscale.com/types/views                                    from tailscale.com/ipn/ipnstate+
+        tailscale.com/util/cloudenv                                  from tailscale.com/hostinfo+
+   W    tailscale.com/util/cmpver                                    from tailscale.com/net/tshttpproxy
+        tailscale.com/util/dnsname                                   from tailscale.com/hostinfo+
+   W    tailscale.com/util/endian                                    from tailscale.com/net/netns
+        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+        tailscale.com/util/singleflight                              from tailscale.com/net/dnscache
+   L    tailscale.com/util/strs                                      from tailscale.com/hostinfo
+   W 💣 tailscale.com/util/winutil                                   from tailscale.com/hostinfo+
+        tailscale.com/version                                        from tailscale.com/derp+
+        tailscale.com/version/distro                                 from tailscale.com/hostinfo+
+        tailscale.com/wgengine/filter                                from tailscale.com/types/netmap
+        golang.org/x/crypto/acme                                     from golang.org/x/crypto/acme/autocert
+        golang.org/x/crypto/acme/autocert                            from tailscale.com/cmd/derper
+        golang.org/x/crypto/argon2                                   from tailscale.com/tka
+        golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box+
+        golang.org/x/crypto/blake2s                                  from tailscale.com/tka
+        golang.org/x/crypto/chacha20                                 from golang.org/x/crypto/chacha20poly1305
+        golang.org/x/crypto/chacha20poly1305                         from crypto/tls
+        golang.org/x/crypto/cryptobyte                               from crypto/ecdsa+
+        golang.org/x/crypto/cryptobyte/asn1                          from crypto/ecdsa+
+        golang.org/x/crypto/curve25519                               from crypto/tls+
+        golang.org/x/crypto/hkdf                                     from crypto/tls
+        golang.org/x/crypto/nacl/box                                 from tailscale.com/types/key
+        golang.org/x/crypto/nacl/secretbox                           from golang.org/x/crypto/nacl/box
+        golang.org/x/crypto/salsa20/salsa                            from golang.org/x/crypto/nacl/box+
+   L    golang.org/x/net/bpf                                         from github.com/mdlayher/netlink+
+        golang.org/x/net/dns/dnsmessage                              from net+
+        golang.org/x/net/http/httpguts                               from net/http
+        golang.org/x/net/http/httpproxy                              from net/http
+        golang.org/x/net/http2/hpack                                 from net/http
+        golang.org/x/net/idna                                        from golang.org/x/crypto/acme/autocert+
+        golang.org/x/net/proxy                                       from tailscale.com/net/netns
+   D    golang.org/x/net/route                                       from net+
+        golang.org/x/sync/errgroup                                   from github.com/mdlayher/socket+
+        golang.org/x/sys/cpu                                         from golang.org/x/crypto/blake2b+
+  LD    golang.org/x/sys/unix                                        from github.com/jsimonetti/rtnetlink/internal/unix+
+   W    golang.org/x/sys/windows                                     from golang.org/x/sys/windows/registry+
+   W    golang.org/x/sys/windows/registry                            from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg+
+        golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
+        golang.org/x/text/transform                                  from golang.org/x/text/secure/bidirule+
+        golang.org/x/text/unicode/bidi                               from golang.org/x/net/idna+
+        golang.org/x/text/unicode/norm                               from golang.org/x/net/idna
+        golang.org/x/time/rate                                       from tailscale.com/cmd/derper+
+        bufio                                                        from compress/flate+
+        bytes                                                        from bufio+
+        compress/flate                                               from compress/gzip+
+        compress/gzip                                                from internal/profile+
+        container/list                                               from crypto/tls+
+        context                                                      from crypto/tls+
+        crypto                                                       from crypto/ecdsa+
+        crypto/aes                                                   from crypto/ecdsa+
+        crypto/cipher                                                from crypto/aes+
+        crypto/des                                                   from crypto/tls+
+        crypto/dsa                                                   from crypto/x509
+        crypto/ecdsa                                                 from crypto/tls+
+        crypto/ed25519                                               from crypto/tls+
+        crypto/elliptic                                              from crypto/ecdsa+
+        crypto/hmac                                                  from crypto/tls+
+        crypto/md5                                                   from crypto/tls+
+        crypto/rand                                                  from crypto/ed25519+
+        crypto/rc4                                                   from crypto/tls
+        crypto/rsa                                                   from crypto/tls+
+        crypto/sha1                                                  from crypto/tls+
+        crypto/sha256                                                from crypto/tls+
+        crypto/sha512                                                from crypto/ecdsa+
+        crypto/subtle                                                from crypto/aes+
+        crypto/tls                                                   from golang.org/x/crypto/acme+
+        crypto/x509                                                  from crypto/tls+
+        crypto/x509/pkix                                             from crypto/x509+
+        embed                                                        from crypto/internal/nistec+
+        encoding                                                     from encoding/json+
+        encoding/asn1                                                from crypto/x509+
+        encoding/base32                                              from tailscale.com/tka
+        encoding/base64                                              from encoding/json+
+        encoding/binary                                              from compress/gzip+
+        encoding/hex                                                 from crypto/x509+
+        encoding/json                                                from expvar+
+        encoding/pem                                                 from crypto/tls+
+        errors                                                       from bufio+
+        expvar                                                       from tailscale.com/cmd/derper+
+        flag                                                         from tailscale.com/cmd/derper
+        fmt                                                          from compress/flate+
+        hash                                                         from crypto+
+        hash/crc32                                                   from compress/gzip+
+        hash/maphash                                                 from go4.org/mem
+        html                                                         from net/http/pprof+
+        io                                                           from bufio+
+        io/fs                                                        from crypto/x509+
+        io/ioutil                                                    from github.com/mitchellh/go-ps+
+        log                                                          from expvar+
+        math                                                         from compress/flate+
+        math/big                                                     from crypto/dsa+
+        math/bits                                                    from compress/flate+
+        math/rand                                                    from github.com/mdlayher/netlink+
+        mime                                                         from mime/multipart+
+        mime/multipart                                               from net/http
+        mime/quotedprintable                                         from mime/multipart
+        net                                                          from crypto/tls+
+        net/http                                                     from expvar+
+        net/http/httptrace                                           from net/http+
+        net/http/internal                                            from net/http
+        net/http/pprof                                               from tailscale.com/tsweb
+        net/netip                                                    from go4.org/netipx+
+        net/textproto                                                from golang.org/x/net/http/httpguts+
+        net/url                                                      from crypto/x509+
+        os                                                           from crypto/rand+
+        os/exec                                                      from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg+
+        path                                                         from golang.org/x/crypto/acme/autocert+
+        path/filepath                                                from crypto/x509+
+        reflect                                                      from crypto/x509+
+        regexp                                                       from internal/profile+
+        regexp/syntax                                                from regexp
+        runtime/debug                                                from golang.org/x/crypto/acme+
+        runtime/pprof                                                from net/http/pprof
+        runtime/trace                                                from net/http/pprof
+        sort                                                         from compress/flate+
+        strconv                                                      from compress/flate+
+        strings                                                      from bufio+
+        sync                                                         from compress/flate+
+        sync/atomic                                                  from context+
+        syscall                                                      from crypto/rand+
+        text/tabwriter                                               from runtime/pprof
+        time                                                         from compress/gzip+
+        unicode                                                      from bytes+
+        unicode/utf16                                                from crypto/x509+
+        unicode/utf8                                                 from bufio+

cmd/derper/derper.go

@@ -12,50 +12,84 @@ import (
 	"errors"
 	"expvar"
 	"flag"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"log"
+	"math"
 	"net"
 	"net/http"
+	"net/netip"
 	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
 	"time"
 
-	"golang.org/x/crypto/acme/autocert"
+	"go4.org/mem"
+	"golang.org/x/time/rate"
 	"tailscale.com/atomicfile"
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
-	"tailscale.com/logpolicy"
 	"tailscale.com/metrics"
 	"tailscale.com/net/stun"
 	"tailscale.com/tsweb"
 	"tailscale.com/types/key"
-	"tailscale.com/types/wgkey"
 )
 
 var (
-	dev           = flag.Bool("dev", false, "run in localhost development mode")
-	addr          = flag.String("a", ":443", "server address")
-	configPath    = flag.String("c", "", "config file path")
-	certDir       = flag.String("certdir", tsweb.DefaultCertDir("derper-certs"), "directory to store LetsEncrypt certs, if addr's port is :443")
-	hostname      = flag.String("hostname", "derp.tailscale.com", "LetsEncrypt host name, if addr's port is :443")
-	logCollection = flag.String("logcollection", "", "If non-empty, logtail collection to log to")
-	runSTUN       = flag.Bool("stun", false, "also run a STUN server")
-	meshPSKFile   = flag.String("mesh-psk-file", defaultMeshPSKFile(), "if non-empty, path to file containing the mesh pre-shared key file. It should contain some hex string; whitespace is trimmed.")
-	meshWith      = flag.String("mesh-with", "", "optional comma-separated list of hostnames to mesh with; the server's own hostname can be in the list")
-	bootstrapDNS  = flag.String("bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns")
-	verifyClients = flag.Bool("verify-clients", false, "verify clients to this DERP server through a local tailscaled instance.")
+	dev        = flag.Bool("dev", false, "run in localhost development mode")
+	addr       = flag.String("a", ":443", "server HTTPS listen address, in form \":port\", \"ip:port\", or for IPv6 \"[ip]:port\". If the IP is omitted, it defaults to all interfaces.")
+	httpPort   = flag.Int("http-port", 80, "The port on which to serve HTTP. Set to -1 to disable. The listener is bound to the same IP (if any) as specified in the -a flag.")
+	stunPort   = flag.Int("stun-port", 3478, "The UDP port on which to serve STUN. The listener is bound to the same IP (if any) as specified in the -a flag.")
+	configPath = flag.String("c", "", "config file path")
+	certMode   = flag.String("certmode", "letsencrypt", "mode for getting a cert. possible options: manual, letsencrypt")
+	certDir    = flag.String("certdir", tsweb.DefaultCertDir("derper-certs"), "directory to store LetsEncrypt certs, if addr's port is :443")
+	hostname   = flag.String("hostname", "derp.tailscale.com", "LetsEncrypt host name, if addr's port is :443")
+	runSTUN    = flag.Bool("stun", true, "whether to run a STUN server. It will bind to the same IP (if any) as the --addr flag value.")
+	runDERP    = flag.Bool("derp", true, "whether to run a DERP server. The only reason to set this false is if you're decommissioning a server but want to keep its bootstrap DNS functionality still running.")
+
+	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")
+	unpublishedDNS = flag.String("unpublished-bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns and not publish in the list")
+	verifyClients  = flag.Bool("verify-clients", false, "verify clients to this DERP server through a local tailscaled instance.")
+
+	acceptConnLimit = flag.Float64("accept-connection-limit", math.Inf(+1), "rate limit for accepting new connection")
+	acceptConnBurst = flag.Int("accept-connection-burst", math.MaxInt, "burst limit for accepting new connection")
 )
 
+var (
+	stats             = new(metrics.Set)
+	stunDisposition   = &metrics.LabelMap{Label: "disposition"}
+	stunAddrFamily    = &metrics.LabelMap{Label: "family"}
+	tlsRequestVersion = &metrics.LabelMap{Label: "version"}
+	tlsActiveVersion  = &metrics.LabelMap{Label: "version"}
+
+	stunReadError  = stunDisposition.Get("read_error")
+	stunNotSTUN    = stunDisposition.Get("not_stun")
+	stunWriteError = stunDisposition.Get("write_error")
+	stunSuccess    = stunDisposition.Get("success")
+
+	stunIPv4 = stunAddrFamily.Get("ipv4")
+	stunIPv6 = stunAddrFamily.Get("ipv6")
+)
+
+func init() {
+	stats.Set("counter_requests", stunDisposition)
+	stats.Set("counter_addrfamily", stunAddrFamily)
+	expvar.Publish("stun", stats)
+	expvar.Publish("derper_tls_request_version", tlsRequestVersion)
+	expvar.Publish("gauge_derper_tls_active_version", tlsActiveVersion)
+}
+
 type config struct {
-	PrivateKey wgkey.Private
+	PrivateKey key.NodePrivate
 }
 
 func loadConfig() config {
 	if *dev {
-		return config{PrivateKey: mustNewKey()}
+		return config{PrivateKey: key.NewNode()}
 	}
 	if *configPath == "" {
 		if os.Getuid() == 0 {
@@ -81,21 +115,13 @@ func loadConfig() config {
 	}
 }
 
-func mustNewKey() wgkey.Private {
-	key, err := wgkey.NewPrivate()
-	if err != nil {
-		log.Fatal(err)
-	}
-	return key
-}
-
 func writeNewConfig() config {
-	key := mustNewKey()
+	k := key.NewNode()
 	if err := os.MkdirAll(filepath.Dir(*configPath), 0777); err != nil {
 		log.Fatal(err)
 	}
 	cfg := config{
-		PrivateKey: key,
+		PrivateKey: k,
 	}
 	b, err := json.MarshalIndent(cfg, "", "\t")
 	if err != nil {
@@ -111,23 +137,21 @@ func main() {
 	flag.Parse()
 
 	if *dev {
-		*logCollection = ""
 		*addr = ":3340" // above the keys DERP
 		log.Printf("Running in dev mode.")
 		tsweb.DevMode = true
 	}
 
-	var logPol *logpolicy.Policy
-	if *logCollection != "" {
-		logPol = logpolicy.New(*logCollection)
-		log.SetOutput(logPol.Logtail)
+	listenHost, _, err := net.SplitHostPort(*addr)
+	if err != nil {
+		log.Fatalf("invalid server address: %v", err)
 	}
 
 	cfg := loadConfig()
 
-	letsEncrypt := tsweb.IsProd443(*addr)
+	serveTLS := tsweb.IsProd443(*addr) || *certMode == "manual"
 
-	s := derp.NewServer(key.Private(cfg.PrivateKey), log.Printf)
+	s := derp.NewServer(cfg.PrivateKey, log.Printf)
 	s.SetVerifyClient(*verifyClients)
 
 	if *meshPSKFile != "" {
@@ -148,7 +172,16 @@ func main() {
 	expvar.Publish("derp", s.ExpVar())
 
 	mux := http.NewServeMux()
-	mux.Handle("/derp", derphttp.Handler(s))
+	if *runDERP {
+		derpHandler := derphttp.Handler(s)
+		derpHandler = addWebSocketSupport(s, derpHandler)
+		mux.Handle("/derp", derpHandler)
+	} else {
+		mux.Handle("/derp", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			http.Error(w, "derp server disabled", http.StatusNotFound)
+		}))
+	}
+	mux.HandleFunc("/derp/probe", probeHandler)
 	go refreshBootstrapDNSLoop()
 	mux.HandleFunc("/bootstrap-dns", handleBootstrapDNS)
 	mux.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -163,10 +196,16 @@ func main() {
   server.
 </p>
 `)
+		if !*runDERP {
+			io.WriteString(w, `<p>Status: <b>disabled</b></p>`)
+		}
 		if tsweb.AllowDebugAccess(r) {
 			io.WriteString(w, "<p>Debug info at <a href='/debug/'>/debug/</a>.</p>\n")
 		}
 	}))
+	mux.Handle("/robots.txt", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, "User-agent: *\nDisallow: /\n")
+	}))
 	debug := tsweb.Debugger(mux)
 	debug.KV("TLS hostname", *hostname)
 	debug.KV("Mesh key", s.HasMeshKey())
@@ -181,48 +220,99 @@ func main() {
 	debug.Handle("traffic", "Traffic check", http.HandlerFunc(s.ServeDebugTraffic))
 
 	if *runSTUN {
-		go serveSTUN()
+		go serveSTUN(listenHost, *stunPort)
 	}
 
+	quietLogger := log.New(logFilter{}, "", 0)
 	httpsrv := &http.Server{
-		Addr:    *addr,
-		Handler: mux,
+		Addr:     *addr,
+		Handler:  mux,
+		ErrorLog: quietLogger,
+
+		// Set read/write timeout. For derper, this basically
+		// only affects TLS setup, as read/write deadlines are
+		// cleared on Hijack, which the DERP server does. But
+		// without this, we slowly accumulate stuck TLS
+		// handshake goroutines forever. This also affects
+		// /debug/ traffic, but 30 seconds is plenty for
+		// Prometheus/etc scraping.
+		ReadTimeout:  30 * time.Second,
+		WriteTimeout: 30 * time.Second,
 	}
 
-	var err error
-	if letsEncrypt {
-		if *certDir == "" {
-			log.Fatalf("missing required --certdir flag")
-		}
+	if serveTLS {
 		log.Printf("derper: serving on %s with TLS", *addr)
-		certManager := &autocert.Manager{
-			Prompt:     autocert.AcceptTOS,
-			HostPolicy: autocert.HostWhitelist(*hostname),
-			Cache:      autocert.DirCache(*certDir),
-		}
-		if *hostname == "derp.tailscale.com" {
-			certManager.HostPolicy = prodAutocertHostPolicy
-			certManager.Email = "security@tailscale.com"
+		var certManager certProvider
+		certManager, err = certProviderByCertMode(*certMode, *certDir, *hostname)
+		if err != nil {
+			log.Fatalf("derper: can not start cert provider: %v", err)
 		}
 		httpsrv.TLSConfig = certManager.TLSConfig()
-		letsEncryptGetCert := httpsrv.TLSConfig.GetCertificate
+		getCert := httpsrv.TLSConfig.GetCertificate
 		httpsrv.TLSConfig.GetCertificate = func(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
-			cert, err := letsEncryptGetCert(hi)
+			cert, err := getCert(hi)
 			if err != nil {
 				return nil, err
 			}
 			cert.Certificate = append(cert.Certificate, s.MetaCert())
 			return cert, nil
 		}
-		go func() {
-			err := http.ListenAndServe(":80", certManager.HTTPHandler(tsweb.Port80Handler{Main: mux}))
-			if err != nil {
-				if err != http.ErrServerClosed {
-					log.Fatal(err)
+		// Disable TLS 1.0 and 1.1, which are obsolete and have security issues.
+		httpsrv.TLSConfig.MinVersion = tls.VersionTLS12
+		httpsrv.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.TLS != nil {
+				label := "unknown"
+				switch r.TLS.Version {
+				case tls.VersionTLS10:
+					label = "1.0"
+				case tls.VersionTLS11:
+					label = "1.1"
+				case tls.VersionTLS12:
+					label = "1.2"
+				case tls.VersionTLS13:
+					label = "1.3"
 				}
+				tlsRequestVersion.Add(label, 1)
+				tlsActiveVersion.Add(label, 1)
+				defer tlsActiveVersion.Add(label, -1)
 			}
-		}()
-		err = httpsrv.ListenAndServeTLS("", "")
+
+			// Set HTTP headers to appease automated security scanners.
+			//
+			// Security automation gets cranky when HTTPS sites don't
+			// set HSTS, and when they don't specify a content
+			// security policy for XSS mitigation.
+			//
+			// DERP's HTTP interface is only ever used for debug
+			// access (for which trivial safe policies work just
+			// fine), and by DERP clients which don't obey any of
+			// these browser-centric headers anyway.
+			w.Header().Set("Strict-Transport-Security", "max-age=63072000; includeSubDomains")
+			w.Header().Set("Content-Security-Policy", "default-src 'none'; frame-ancestors 'none'; form-action 'none'; base-uri 'self'; block-all-mixed-content; plugin-types 'none'")
+			mux.ServeHTTP(w, r)
+		})
+		if *httpPort > -1 {
+			go func() {
+				port80srv := &http.Server{
+					Addr:        net.JoinHostPort(listenHost, fmt.Sprintf("%d", *httpPort)),
+					Handler:     certManager.HTTPHandler(tsweb.Port80Handler{Main: mux}),
+					ErrorLog:    quietLogger,
+					ReadTimeout: 30 * time.Second,
+					// Crank up WriteTimeout a bit more than usually
+					// necessary just so we can do long CPU profiles
+					// and not hit net/http/pprof's "profile
+					// duration exceeds server's WriteTimeout".
+					WriteTimeout: 5 * time.Minute,
+				}
+				err := port80srv.ListenAndServe()
+				if err != nil {
+					if err != http.ErrServerClosed {
+						log.Fatal(err)
+					}
+				}
+			}()
+		}
+		err = rateLimitedListenAndServeTLS(httpsrv)
 	} else {
 		log.Printf("derper: serving on %s", *addr)
 		err = httpsrv.ListenAndServe()
@@ -232,45 +322,44 @@ func main() {
 	}
 }
 
-func serveSTUN() {
-	pc, err := net.ListenPacket("udp", ":3478")
+// probeHandler is the endpoint that js/wasm clients hit to measure
+// DERP latency, since they can't do UDP STUN queries.
+func probeHandler(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case "HEAD", "GET":
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+	default:
+		http.Error(w, "bogus probe method", http.StatusMethodNotAllowed)
+	}
+}
+
+func serveSTUN(host string, port int) {
+	pc, err := net.ListenPacket("udp", net.JoinHostPort(host, fmt.Sprint(port)))
 	if err != nil {
 		log.Fatalf("failed to open STUN listener: %v", err)
 	}
 	log.Printf("running STUN server on %v", pc.LocalAddr())
+	serverSTUNListener(context.Background(), pc.(*net.UDPConn))
+}
 
-	var (
-		stats           = new(metrics.Set)
-		stunDisposition = &metrics.LabelMap{Label: "disposition"}
-		stunAddrFamily  = &metrics.LabelMap{Label: "family"}
-
-		stunReadError  = stunDisposition.Get("read_error")
-		stunNotSTUN    = stunDisposition.Get("not_stun")
-		stunWriteError = stunDisposition.Get("write_error")
-		stunSuccess    = stunDisposition.Get("success")
-
-		stunIPv4 = stunAddrFamily.Get("ipv4")
-		stunIPv6 = stunAddrFamily.Get("ipv6")
-	)
-	stats.Set("counter_requests", stunDisposition)
-	stats.Set("counter_addrfamily", stunAddrFamily)
-	expvar.Publish("stun", stats)
-
+func serverSTUNListener(ctx context.Context, pc *net.UDPConn) {
 	var buf [64 << 10]byte
+	var (
+		n   int
+		ua  *net.UDPAddr
+		err error
+	)
 	for {
-		n, addr, err := pc.ReadFrom(buf[:])
+		n, ua, err = pc.ReadFromUDP(buf[:])
 		if err != nil {
+			if ctx.Err() != nil {
+				return
+			}
 			log.Printf("STUN ReadFrom: %v", err)
 			time.Sleep(time.Second)
 			stunReadError.Add(1)
 			continue
 		}
-		ua, ok := addr.(*net.UDPAddr)
-		if !ok {
-			log.Printf("STUN unexpected address %T %v", addr, addr)
-			stunReadError.Add(1)
-			continue
-		}
 		pkt := buf[:n]
 		if !stun.Is(pkt) {
 			stunNotSTUN.Add(1)
@@ -286,8 +375,9 @@ func serveSTUN() {
 		} else {
 			stunIPv6.Add(1)
 		}
-		res := stun.Response(txid, ua.IP, uint16(ua.Port))
-		_, err = pc.WriteTo(res, addr)
+		addr, _ := netip.AddrFromSlice(ua.IP)
+		res := stun.Response(txid, netip.AddrPortFrom(addr, uint16(ua.Port)))
+		_, err = pc.WriteTo(res, ua)
 		if err != nil {
 			stunWriteError.Add(1)
 		} else {
@@ -317,3 +407,82 @@ func defaultMeshPSKFile() string {
 	}
 	return ""
 }
+
+func rateLimitedListenAndServeTLS(srv *http.Server) error {
+	addr := srv.Addr
+	if addr == "" {
+		addr = ":https"
+	}
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
+		return err
+	}
+	rln := newRateLimitedListener(ln, rate.Limit(*acceptConnLimit), *acceptConnBurst)
+	expvar.Publish("tls_listener", rln.ExpVar())
+	defer rln.Close()
+	return srv.ServeTLS(rln, "", "")
+}
+
+type rateLimitedListener struct {
+	// These are at the start of the struct to ensure 64-bit alignment
+	// on 32-bit architecture regardless of what other fields may exist
+	// in this package.
+	numAccepts expvar.Int // does not include number of rejects
+	numRejects expvar.Int
+
+	net.Listener
+
+	lim *rate.Limiter
+}
+
+func newRateLimitedListener(ln net.Listener, limit rate.Limit, burst int) *rateLimitedListener {
+	return &rateLimitedListener{Listener: ln, lim: rate.NewLimiter(limit, burst)}
+}
+
+func (l *rateLimitedListener) ExpVar() expvar.Var {
+	m := new(metrics.Set)
+	m.Set("counter_accepted_connections", &l.numAccepts)
+	m.Set("counter_rejected_connections", &l.numRejects)
+	return m
+}
+
+var errLimitedConn = errors.New("cannot accept connection; rate limited")
+
+func (l *rateLimitedListener) Accept() (net.Conn, error) {
+	// Even under a rate limited situation, we accept the connection immediately
+	// and close it, rather than being slow at accepting new connections.
+	// This provides two benefits: 1) it signals to the client that something
+	// is going on on the server, and 2) it prevents new connections from
+	// piling up and occupying resources in the OS kernel.
+	// The client will retry as needing (with backoffs in place).
+	cn, err := l.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+	if !l.lim.Allow() {
+		l.numRejects.Add(1)
+		cn.Close()
+		return nil, errLimitedConn
+	}
+	l.numAccepts.Add(1)
+	return cn, nil
+}
+
+// logFilter is used to filter out useless error logs that are logged to
+// the net/http.Server.ErrorLog logger.
+type logFilter struct{}
+
+func (logFilter) Write(p []byte) (int, error) {
+	b := mem.B(p)
+	if mem.HasSuffix(b, mem.S(": EOF\n")) ||
+		mem.HasSuffix(b, mem.S(": i/o timeout\n")) ||
+		mem.HasSuffix(b, mem.S(": read: connection reset by peer\n")) ||
+		mem.HasSuffix(b, mem.S(": remote error: tls: bad certificate\n")) ||
+		mem.HasSuffix(b, mem.S(": tls: first record does not look like a TLS handshake\n")) {
+		// Skip this log message, but say that we processed it
+		return len(p), nil
+	}
+
+	log.Printf("%s", p)
+	return len(p), nil
+}

cmd/derper/derper_test.go

@@ -6,7 +6,10 @@ package main
 
 import (
 	"context"
+	"net"
 	"testing"
+
+	"tailscale.com/net/stun"
 )
 
 func TestProdAutocertHostPolicy(t *testing.T) {
@@ -31,5 +34,36 @@ func TestProdAutocertHostPolicy(t *testing.T) {
 			t.Errorf("f(%q) = %v; want %v", tt.in, got, tt.wantOK)
 		}
 	}
+}
+
+func BenchmarkServerSTUN(b *testing.B) {
+	b.ReportAllocs()
+	pc, err := net.ListenPacket("udp", "127.0.0.1:0")
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer pc.Close()
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go serverSTUNListener(ctx, pc.(*net.UDPConn))
+	addr := pc.LocalAddr().(*net.UDPAddr)
+
+	var resBuf [1500]byte
+	cc, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.ParseIP("127.0.0.1")})
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	tx := stun.NewTxID()
+	req := stun.Request(tx)
+	for i := 0; i < b.N; i++ {
+		if _, err := cc.WriteToUDP(req, addr); err != nil {
+			b.Fatal(err)
+		}
+		_, _, err := cc.ReadFromUDP(resBuf[:])
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
 
 }

cmd/derper/mesh.go

@@ -69,8 +69,8 @@ func startMeshWithHost(s *derp.Server, host string) error {
 		return d.DialContext(ctx, network, addr)
 	})
 
-	add := func(k key.Public) { s.AddPacketForwarder(k, c) }
-	remove := func(k key.Public) { s.RemovePacketForwarder(k, c) }
+	add := func(k key.NodePublic) { s.AddPacketForwarder(k, c) }
+	remove := func(k key.NodePublic) { s.RemovePacketForwarder(k, c) }
 	go c.RunWatchConnectionLoop(context.Background(), s.PublicKey(), logf, add, remove)
 	return nil
 }

cmd/derper/websocket.go

@@ -0,0 +1,51 @@
+// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bufio"
+	"expvar"
+	"log"
+	"net/http"
+	"strings"
+
+	"nhooyr.io/websocket"
+	"tailscale.com/derp"
+)
+
+var counterWebSocketAccepts = expvar.NewInt("derp_websocket_accepts")
+
+// addWebSocketSupport returns a Handle wrapping base that adds WebSocket server support.
+func addWebSocketSupport(s *derp.Server, base http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		up := strings.ToLower(r.Header.Get("Upgrade"))
+
+		// Very early versions of Tailscale set "Upgrade: WebSocket" but didn't actually
+		// speak WebSockets (they still assumed DERP's binary framining). So to distinguish
+		// clients that actually want WebSockets, look for an explicit "derp" subprotocol.
+		if up != "websocket" || !strings.Contains(r.Header.Get("Sec-Websocket-Protocol"), "derp") {
+			base.ServeHTTP(w, r)
+			return
+		}
+
+		c, err := websocket.Accept(w, r, &websocket.AcceptOptions{
+			Subprotocols:   []string{"derp"},
+			OriginPatterns: []string{"*"},
+		})
+		if err != nil {
+			log.Printf("websocket.Accept: %v", err)
+			return
+		}
+		defer c.Close(websocket.StatusInternalError, "closing")
+		if c.Subprotocol() != "derp" {
+			c.Close(websocket.StatusPolicyViolation, "client must speak the derp subprotocol")
+			return
+		}
+		counterWebSocketAccepts.Add(1)
+		wc := websocket.NetConn(r.Context(), c, websocket.MessageBinary)
+		brw := bufio.NewReadWriter(bufio.NewReader(wc), bufio.NewWriter(wc))
+		s.Accept(r.Context(), wc, brw, r.RemoteAddr)
+	})
+}

cmd/derpprobe/derpprobe.go

@@ -9,19 +9,25 @@ import (
 	"bytes"
 	"context"
 	crand "crypto/rand"
+	"crypto/x509"
 	"encoding/json"
+	"errors"
 	"flag"
 	"fmt"
 	"html"
 	"io"
 	"log"
+	"net"
 	"net/http"
+	"os"
 	"sort"
+	"strings"
 	"sync"
 	"time"
 
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
+	"tailscale.com/net/stun"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
 )
@@ -31,28 +37,52 @@ var (
 	listen     = flag.String("listen", ":8030", "HTTP listen address")
 )
 
+// certReissueAfter is the time after which we expect all certs to be
+// reissued, at minimum.
+//
+// This is currently set to the date of the LetsEncrypt ALPN revocation event of Jan 2022:
+// https://community.letsencrypt.org/t/questions-about-renewing-before-tls-alpn-01-revocations/170449
+//
+// If there's another revocation event, bump this again.
+var certReissueAfter = time.Unix(1643226768, 0)
+
 var (
 	mu            sync.Mutex
 	state         = map[nodePair]pairStatus{}
 	lastDERPMap   *tailcfg.DERPMap
 	lastDERPMapAt time.Time
+	certs         = map[string]*x509.Certificate{}
 )
 
 func main() {
 	flag.Parse()
+
+	// proactively load the DERP map. Nothing terrible happens if this fails, so we ignore
+	// the error. The Slack bot will print a notification that the DERP map was empty.
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	_, _ = getDERPMap(ctx)
+
 	go probeLoop()
+	go slackLoop()
 	log.Fatal(http.ListenAndServe(*listen, http.HandlerFunc(serve)))
 }
 
+func setCert(name string, cert *x509.Certificate) {
+	mu.Lock()
+	defer mu.Unlock()
+	certs[name] = cert
+}
+
 type overallStatus struct {
 	good, bad []string
 }
 
-func (st *overallStatus) addBadf(format string, a ...interface{}) {
+func (st *overallStatus) addBadf(format string, a ...any) {
 	st.bad = append(st.bad, fmt.Sprintf(format, a...))
 }
 
-func (st *overallStatus) addGoodf(format string, a ...interface{}) {
+func (st *overallStatus) addGoodf(format string, a ...any) {
 	st.good = append(st.good, fmt.Sprintf(format, a...))
 }
 
@@ -67,35 +97,65 @@ func getOverallStatus() (o overallStatus) {
 	if age := now.Sub(lastDERPMapAt); age > time.Minute {
 		o.addBadf("DERPMap hasn't been successfully refreshed in %v", age.Round(time.Second))
 	}
+
+	addPairMeta := func(pair nodePair) {
+		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)
+		}
+	}
+
 	for _, reg := range sortedRegions(lastDERPMap) {
 		for _, from := range reg.Nodes {
+			addPairMeta(nodePair{"UDP", from.Name})
 			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)
-				}
+				addPairMeta(nodePair{from.Name, to.Name})
 			}
 		}
 	}
+
+	var subjs []string
+	for k := range certs {
+		subjs = append(subjs, k)
+	}
+	sort.Strings(subjs)
+
+	soon := time.Now().Add(14 * 24 * time.Hour) // in 2 weeks; autocert does 30 days by default
+	for _, s := range subjs {
+		cert := certs[s]
+		if cert.NotBefore.Before(certReissueAfter) {
+			o.addBadf("cert %q needs reissuing; NotBefore=%v", s, cert.NotBefore.Format(time.RFC3339))
+			continue
+		}
+		if cert.NotAfter.Before(soon) {
+			o.addBadf("cert %q expiring soon (%v); wasn't auto-refreshed", s, cert.NotAfter.Format(time.RFC3339))
+			continue
+		}
+		o.addGoodf("cert %q good %v - %v", s, cert.NotBefore.Format(time.RFC3339), cert.NotAfter.Format(time.RFC3339))
+	}
+
 	return
 }
 
 func serve(w http.ResponseWriter, r *http.Request) {
 	st := getOverallStatus()
 	summary := "All good"
-	if len(st.bad) > 0 {
+	if (float64(len(st.bad)) / float64(len(st.bad)+len(st.good))) > 0.25 {
+		// This will generate an alert and page a human.
+		// It also ends up in Slack, but as part of the alert handling pipeline not
+		// because we generated a Slack notification from here.
 		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 {
@@ -107,6 +167,71 @@ func serve(w http.ResponseWriter, r *http.Request) {
 	io.WriteString(w, "</ul></body></html>\n")
 }
 
+func notifySlack(text string) error {
+	type SlackRequestBody struct {
+		Text string `json:"text"`
+	}
+
+	slackBody, err := json.Marshal(SlackRequestBody{Text: text})
+	if err != nil {
+		return err
+	}
+
+	webhookUrl := os.Getenv("SLACK_WEBHOOK")
+	if webhookUrl == "" {
+		return errors.New("No SLACK_WEBHOOK configured")
+	}
+
+	req, err := http.NewRequest("POST", webhookUrl, bytes.NewReader(slackBody))
+	if err != nil {
+		return err
+	}
+	req.Header.Add("Content-Type", "application/json")
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return errors.New(resp.Status)
+	}
+
+	body, _ := io.ReadAll(resp.Body)
+	if string(body) != "ok" {
+		return errors.New("Non-ok response returned from Slack")
+	}
+	return nil
+}
+
+// We only page a human if it looks like there is a significant outage across multiple regions.
+// To Slack, we report all failures great and small.
+func slackLoop() {
+	inBadState := false
+	for {
+		time.Sleep(time.Second * 30)
+		st := getOverallStatus()
+
+		if len(st.bad) > 0 && !inBadState {
+			err := notifySlack(strings.Join(st.bad, "\n"))
+			if err == nil {
+				inBadState = true
+			} else {
+				log.Printf("%d problems, notify Slack failed: %v", len(st.bad), err)
+			}
+		}
+
+		if len(st.bad) == 0 && inBadState {
+			err := notifySlack("All DERPs recovered.")
+			if err == nil {
+				inBadState = false
+			}
+		}
+	}
+}
+
 func sortedRegions(dm *tailcfg.DERPMap) []*tailcfg.DERPRegion {
 	ret := make([]*tailcfg.DERPRegion, 0, len(dm.Regions))
 	for _, r := range dm.Regions {
@@ -117,7 +242,8 @@ func sortedRegions(dm *tailcfg.DERPMap) []*tailcfg.DERPRegion {
 }
 
 type nodePair struct {
-	from, to string // DERPNode.Name
+	from string // DERPNode.Name, or "UDP" for a STUN query to 'to'
+	to   string // DERPNode.Name
 }
 
 func (p nodePair) String() string { return fmt.Sprintf("(%s→%s)", p.from, p.to) }
@@ -177,6 +303,8 @@ func probe() error {
 		go func() {
 			defer wg.Done()
 			for _, from := range reg.Nodes {
+				latency, err := probeUDP(ctx, dm, from)
+				setState(nodePair{"UDP", from.Name}, latency, err)
 				for _, to := range reg.Nodes {
 					latency, err := probeNodePair(ctx, dm, from, to)
 					setState(nodePair{from.Name, to.Name}, latency, err)
@@ -189,6 +317,65 @@ func probe() error {
 	return ctx.Err()
 }
 
+func probeUDP(ctx context.Context, dm *tailcfg.DERPMap, n *tailcfg.DERPNode) (latency time.Duration, err error) {
+	pc, err := net.ListenPacket("udp", ":0")
+	if err != nil {
+		return 0, err
+	}
+	defer pc.Close()
+	uc := pc.(*net.UDPConn)
+
+	tx := stun.NewTxID()
+	req := stun.Request(tx)
+
+	for _, ipStr := range []string{n.IPv4, n.IPv6} {
+		if ipStr == "" {
+			continue
+		}
+		port := n.STUNPort
+		if port == -1 {
+			continue
+		}
+		if port == 0 {
+			port = 3478
+		}
+		for {
+			ip := net.ParseIP(ipStr)
+			_, err := uc.WriteToUDP(req, &net.UDPAddr{IP: ip, Port: port})
+			if err != nil {
+				return 0, err
+			}
+			buf := make([]byte, 1500)
+			uc.SetReadDeadline(time.Now().Add(2 * time.Second))
+			t0 := time.Now()
+			n, _, err := uc.ReadFromUDP(buf)
+			d := time.Since(t0)
+			if err != nil {
+				if ctx.Err() != nil {
+					return 0, fmt.Errorf("timeout reading from %v: %v", ip, err)
+				}
+				if d < time.Second {
+					return 0, fmt.Errorf("error reading from %v: %v", ip, err)
+				}
+				time.Sleep(100 * time.Millisecond)
+				continue
+			}
+			txBack, _, err := stun.ParseResponse(buf[:n])
+			if err != nil {
+				return 0, fmt.Errorf("parsing STUN response from %v: %v", ip, err)
+			}
+			if txBack != tx {
+				return 0, fmt.Errorf("read wrong tx back from %v", ip)
+			}
+			if latency == 0 || d < latency {
+				latency = d
+			}
+			break
+		}
+	}
+	return latency, nil
+}
+
 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
@@ -239,7 +426,7 @@ func probeNodePair(ctx context.Context, dm *tailcfg.DERPMap, from, to *tailcfg.D
 	}
 
 	// Receive the random packet.
-	recvc := make(chan interface{}, 1) // either derp.ReceivedPacket or error
+	recvc := make(chan any, 1) // either derp.ReceivedPacket or error
 	go func() {
 		for {
 			m, err := toc.Recv()
@@ -275,7 +462,7 @@ func probeNodePair(ctx context.Context, dm *tailcfg.DERPMap, from, to *tailcfg.D
 }
 
 func newConn(ctx context.Context, dm *tailcfg.DERPMap, n *tailcfg.DERPNode) (*derphttp.Client, error) {
-	priv := key.NewPrivate()
+	priv := key.NewNode()
 	dc := derphttp.NewRegionClient(priv, log.Printf, func() *tailcfg.DERPRegion {
 		rid := n.RegionID
 		return &tailcfg.DERPRegion{
@@ -290,6 +477,21 @@ func newConn(ctx context.Context, dm *tailcfg.DERPMap, n *tailcfg.DERPNode) (*de
 	if err != nil {
 		return nil, err
 	}
+	cs, ok := dc.TLSConnectionState()
+	if !ok {
+		dc.Close()
+		return nil, errors.New("no TLS state")
+	}
+	if len(cs.PeerCertificates) == 0 {
+		dc.Close()
+		return nil, errors.New("no peer certificates")
+	}
+	if cs.ServerName != n.HostName {
+		dc.Close()
+		return nil, fmt.Errorf("TLS server name %q != derp hostname %q", cs.ServerName, n.HostName)
+	}
+	setCert(cs.ServerName, cs.PeerCertificates[0])
+
 	errc := make(chan error, 1)
 	go func() {
 		m, err := dc.Recv()

cmd/gitops-pusher/.gitignore

@@ -0,0 +1 @@
+version-cache.json

cmd/gitops-pusher/README.md

@@ -0,0 +1,48 @@
+# gitops-pusher
+
+This is a small tool to help people achieve a
+[GitOps](https://about.gitlab.com/topics/gitops/) workflow with Tailscale ACL
+changes. This tool is intended to be used in a CI flow that looks like this:
+
+```yaml
+name: Tailscale ACL syncing
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  acls:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      
+      - name: Setup Go environment
+        uses: actions/setup-go@v3.2.0
+        
+      - name: Install gitops-pusher
+        run: go install tailscale.com/cmd/gitops-pusher@latest
+              
+      - name: Deploy ACL
+        if: github.event_name == 'push'
+        env:
+          TS_API_KEY: ${{ secrets.TS_API_KEY }}
+          TS_TAILNET: ${{ secrets.TS_TAILNET }}
+        run: |
+          ~/go/bin/gitops-pusher --policy-file ./policy.hujson apply
+
+      - name: ACL tests
+        if: github.event_name == 'pull_request'
+        env:
+          TS_API_KEY: ${{ secrets.TS_API_KEY }}
+          TS_TAILNET: ${{ secrets.TS_TAILNET }}
+        run: |
+          ~/go/bin/gitops-pusher --policy-file ./policy.hujson test
+```
+
+Change the value of the `--policy-file` flag to point to the policy file on
+disk. Policy files should be in [HuJSON](https://github.com/tailscale/hujson)
+format.

cmd/gitops-pusher/cache.go

@@ -0,0 +1,67 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"encoding/json"
+	"os"
+)
+
+// Cache contains cached information about the last time this tool was run.
+//
+// This is serialized to a JSON file that should NOT be checked into git.
+// It should be managed with either CI cache tools or stored locally somehow. The
+// exact mechanism is irrelevant as long as it is consistent.
+//
+// This allows gitops-pusher to detect external ACL changes. I'm not sure what to
+// call this problem, so I've been calling it the "three version problem" in my
+// notes. The basic problem is that at any given time we only have two versions
+// of the ACL file at any given point. In order to check if there has been
+// tampering of the ACL files in the admin panel, we need to have a _third_ version
+// to compare against.
+//
+// In this case I am not storing the old ACL entirely (though that could be a
+// reasonable thing to add in the future), but only its sha256sum. This allows
+// us to detect if the shasum in control matches the shasum we expect, and if that
+// expectation fails, then we can react accordingly.
+type Cache struct {
+	PrevETag string // Stores the previous ETag of the ACL to allow
+}
+
+// Save persists the cache to a given file.
+func (c *Cache) Save(fname string) error {
+	os.Remove(fname)
+	fout, err := os.Create(fname)
+	if err != nil {
+		return err
+	}
+	defer fout.Close()
+
+	return json.NewEncoder(fout).Encode(c)
+}
+
+// LoadCache loads the cache from a given file.
+func LoadCache(fname string) (*Cache, error) {
+	var result Cache
+
+	fin, err := os.Open(fname)
+	if err != nil {
+		return nil, err
+	}
+	defer fin.Close()
+
+	err = json.NewDecoder(fin).Decode(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	return &result, nil
+}
+
+// Shuck removes the first and last character of a string, analogous to
+// shucking off the husk of an ear of corn.
+func Shuck(s string) string {
+	return s[1 : len(s)-1]
+}

cmd/gitops-pusher/gitops-pusher.go

@@ -0,0 +1,370 @@
+// Copyright (c) 2022 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.
+
+// Command gitops-pusher allows users to use a GitOps flow for managing Tailscale ACLs.
+//
+// See README.md for more details.
+package main
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/peterbourgon/ff/v3/ffcli"
+	"github.com/tailscale/hujson"
+)
+
+var (
+	rootFlagSet  = flag.NewFlagSet("gitops-pusher", flag.ExitOnError)
+	policyFname  = rootFlagSet.String("policy-file", "./policy.hujson", "filename for policy file")
+	cacheFname   = rootFlagSet.String("cache-file", "./version-cache.json", "filename for the previous known version hash")
+	timeout      = rootFlagSet.Duration("timeout", 5*time.Minute, "timeout for the entire CI run")
+	githubSyntax = rootFlagSet.Bool("github-syntax", true, "use GitHub Action error syntax (https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-error-message)")
+)
+
+func modifiedExternallyError() {
+	if *githubSyntax {
+		fmt.Printf("::warning file=%s,line=1,col=1,title=Policy File Modified Externally::The policy file was modified externally in the admin console.\n", *policyFname)
+	} else {
+		fmt.Printf("The policy file was modified externally in the admin console.\n")
+	}
+}
+
+func apply(cache *Cache, tailnet, apiKey string) func(context.Context, []string) error {
+	return func(ctx context.Context, args []string) error {
+		controlEtag, err := getACLETag(ctx, tailnet, apiKey)
+		if err != nil {
+			return err
+		}
+
+		localEtag, err := sumFile(*policyFname)
+		if err != nil {
+			return err
+		}
+
+		if cache.PrevETag == "" {
+			log.Println("no previous etag found, assuming local file is correct and recording that")
+			cache.PrevETag = localEtag
+		}
+
+		log.Printf("control: %s", controlEtag)
+		log.Printf("local:   %s", localEtag)
+		log.Printf("cache:   %s", cache.PrevETag)
+
+		if cache.PrevETag != controlEtag {
+			modifiedExternallyError()
+		}
+
+		if controlEtag == localEtag {
+			cache.PrevETag = localEtag
+			log.Println("no update needed, doing nothing")
+			return nil
+		}
+
+		if err := applyNewACL(ctx, tailnet, apiKey, *policyFname, controlEtag); err != nil {
+			return err
+		}
+
+		cache.PrevETag = localEtag
+
+		return nil
+	}
+}
+
+func test(cache *Cache, tailnet, apiKey string) func(context.Context, []string) error {
+	return func(ctx context.Context, args []string) error {
+		controlEtag, err := getACLETag(ctx, tailnet, apiKey)
+		if err != nil {
+			return err
+		}
+
+		localEtag, err := sumFile(*policyFname)
+		if err != nil {
+			return err
+		}
+
+		if cache.PrevETag == "" {
+			log.Println("no previous etag found, assuming local file is correct and recording that")
+			cache.PrevETag = localEtag
+		}
+
+		log.Printf("control: %s", controlEtag)
+		log.Printf("local:   %s", localEtag)
+		log.Printf("cache:   %s", cache.PrevETag)
+
+		if cache.PrevETag != controlEtag {
+			modifiedExternallyError()
+		}
+
+		if controlEtag == localEtag {
+			log.Println("no updates found, doing nothing")
+			return nil
+		}
+
+		if err := testNewACLs(ctx, tailnet, apiKey, *policyFname); err != nil {
+			return err
+		}
+		return nil
+	}
+}
+
+func getChecksums(cache *Cache, tailnet, apiKey string) func(context.Context, []string) error {
+	return func(ctx context.Context, args []string) error {
+		controlEtag, err := getACLETag(ctx, tailnet, apiKey)
+		if err != nil {
+			return err
+		}
+
+		localEtag, err := sumFile(*policyFname)
+		if err != nil {
+			return err
+		}
+
+		if cache.PrevETag == "" {
+			log.Println("no previous etag found, assuming local file is correct and recording that")
+			cache.PrevETag = Shuck(localEtag)
+		}
+
+		log.Printf("control: %s", controlEtag)
+		log.Printf("local:   %s", localEtag)
+		log.Printf("cache:   %s", cache.PrevETag)
+
+		return nil
+	}
+}
+
+func main() {
+	tailnet, ok := os.LookupEnv("TS_TAILNET")
+	if !ok {
+		log.Fatal("set envvar TS_TAILNET to your tailnet's name")
+	}
+	apiKey, ok := os.LookupEnv("TS_API_KEY")
+	if !ok {
+		log.Fatal("set envvar TS_API_KEY to your Tailscale API key")
+	}
+	cache, err := LoadCache(*cacheFname)
+	if err != nil {
+		if os.IsNotExist(err) {
+			cache = &Cache{}
+		} else {
+			log.Fatalf("error loading cache: %v", err)
+		}
+	}
+	defer cache.Save(*cacheFname)
+
+	applyCmd := &ffcli.Command{
+		Name:       "apply",
+		ShortUsage: "gitops-pusher [options] apply",
+		ShortHelp:  "Pushes changes to CONTROL",
+		LongHelp:   `Pushes changes to CONTROL`,
+		Exec:       apply(cache, tailnet, apiKey),
+	}
+
+	testCmd := &ffcli.Command{
+		Name:       "test",
+		ShortUsage: "gitops-pusher [options] test",
+		ShortHelp:  "Tests ACL changes",
+		LongHelp:   "Tests ACL changes",
+		Exec:       test(cache, tailnet, apiKey),
+	}
+
+	cksumCmd := &ffcli.Command{
+		Name:       "checksum",
+		ShortUsage: "Shows checksums of ACL files",
+		ShortHelp:  "Fetch checksum of CONTROL's ACL and the local ACL for comparison",
+		LongHelp:   "Fetch checksum of CONTROL's ACL and the local ACL for comparison",
+		Exec:       getChecksums(cache, tailnet, apiKey),
+	}
+
+	root := &ffcli.Command{
+		ShortUsage:  "gitops-pusher [options] <command>",
+		ShortHelp:   "Push Tailscale ACLs to CONTROL using a GitOps workflow",
+		Subcommands: []*ffcli.Command{applyCmd, cksumCmd, testCmd},
+		FlagSet:     rootFlagSet,
+	}
+
+	if err := root.Parse(os.Args[1:]); err != nil {
+		log.Fatal(err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), *timeout)
+	defer cancel()
+
+	if err := root.Run(ctx); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func sumFile(fname string) (string, error) {
+	data, err := os.ReadFile(fname)
+	if err != nil {
+		return "", err
+	}
+
+	formatted, err := hujson.Format(data)
+	if err != nil {
+		return "", err
+	}
+
+	h := sha256.New()
+	_, err = h.Write(formatted)
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%x", h.Sum(nil)), nil
+}
+
+func applyNewACL(ctx context.Context, tailnet, apiKey, policyFname, oldEtag string) error {
+	fin, err := os.Open(policyFname)
+	if err != nil {
+		return err
+	}
+	defer fin.Close()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("https://api.tailscale.com/api/v2/tailnet/%s/acl", tailnet), fin)
+	if err != nil {
+		return err
+	}
+
+	req.SetBasicAuth(apiKey, "")
+	req.Header.Set("Content-Type", "application/hujson")
+	req.Header.Set("If-Match", `"`+oldEtag+`"`)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	got := resp.StatusCode
+	want := http.StatusOK
+	if got != want {
+		var ate ACLTestError
+		err := json.NewDecoder(resp.Body).Decode(&ate)
+		if err != nil {
+			return err
+		}
+
+		return ate
+	}
+
+	return nil
+}
+
+func testNewACLs(ctx context.Context, tailnet, apiKey, policyFname string) error {
+	data, err := os.ReadFile(policyFname)
+	if err != nil {
+		return err
+	}
+	data, err = hujson.Standardize(data)
+	if err != nil {
+		return err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("https://api.tailscale.com/api/v2/tailnet/%s/acl/validate", tailnet), bytes.NewBuffer(data))
+	if err != nil {
+		return err
+	}
+
+	req.SetBasicAuth(apiKey, "")
+	req.Header.Set("Content-Type", "application/hujson")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	var ate ACLTestError
+	err = json.NewDecoder(resp.Body).Decode(&ate)
+	if err != nil {
+		return err
+	}
+
+	if len(ate.Message) != 0 || len(ate.Data) != 0 {
+		return ate
+	}
+
+	got := resp.StatusCode
+	want := http.StatusOK
+	if got != want {
+		return fmt.Errorf("wanted HTTP status code %d but got %d", want, got)
+	}
+
+	return nil
+}
+
+var lineColMessageSplit = regexp.MustCompile(`line ([0-9]+), column ([0-9]+): (.*)$`)
+
+type ACLTestError struct {
+	Message string               `json:"message"`
+	Data    []ACLTestErrorDetail `json:"data"`
+}
+
+func (ate ACLTestError) Error() string {
+	var sb strings.Builder
+
+	if *githubSyntax && lineColMessageSplit.MatchString(ate.Message) {
+		sp := lineColMessageSplit.FindStringSubmatch(ate.Message)
+
+		line := sp[1]
+		col := sp[2]
+		msg := sp[3]
+
+		fmt.Fprintf(&sb, "::error file=%s,line=%s,col=%s::%s", *policyFname, line, col, msg)
+	} else {
+		fmt.Fprintln(&sb, ate.Message)
+	}
+	fmt.Fprintln(&sb)
+
+	for _, data := range ate.Data {
+		fmt.Fprintf(&sb, "For user %s:\n", data.User)
+		for _, err := range data.Errors {
+			fmt.Fprintf(&sb, "- %s\n", err)
+		}
+	}
+
+	return sb.String()
+}
+
+type ACLTestErrorDetail struct {
+	User   string   `json:"user"`
+	Errors []string `json:"errors"`
+}
+
+func getACLETag(ctx context.Context, tailnet, apiKey string) (string, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("https://api.tailscale.com/api/v2/tailnet/%s/acl", tailnet), nil)
+	if err != nil {
+		return "", err
+	}
+
+	req.SetBasicAuth(apiKey, "")
+	req.Header.Set("Accept", "application/hujson")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	got := resp.StatusCode
+	want := http.StatusOK
+	if got != want {
+		return "", fmt.Errorf("wanted HTTP status code %d but got %d", want, got)
+	}
+
+	return Shuck(resp.Header.Get("ETag")), nil
+}

cmd/hello/hello.go

@@ -2,13 +2,15 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// The hello binary runs hello.ipn.dev.
+// The hello binary runs hello.ts.net.
 package main // import "tailscale.com/cmd/hello"
 
 import (
 	"context"
+	"crypto/tls"
 	_ "embed"
 	"encoding/json"
+	"errors"
 	"flag"
 	"html/template"
 	"io/ioutil"
@@ -16,6 +18,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"time"
 
 	"tailscale.com/client/tailscale"
 	"tailscale.com/client/tailscale/apitype"
@@ -69,11 +72,31 @@ func main() {
 	if *httpsAddr != "" {
 		log.Printf("running HTTPS server on %s", *httpsAddr)
 		go func() {
-			errc <- http.ListenAndServeTLS(*httpsAddr,
-				"/etc/hello/hello.ipn.dev.crt",
-				"/etc/hello/hello.ipn.dev.key",
-				nil,
-			)
+			hs := &http.Server{
+				Addr: *httpsAddr,
+				TLSConfig: &tls.Config{
+					GetCertificate: func(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
+						switch hi.ServerName {
+						case "hello.ts.net":
+							return tailscale.GetCertificate(hi)
+						case "hello.ipn.dev":
+							c, err := tls.LoadX509KeyPair(
+								"/etc/hello/hello.ipn.dev.crt",
+								"/etc/hello/hello.ipn.dev.key",
+							)
+							if err != nil {
+								return nil, err
+							}
+							return &c, nil
+						}
+						return nil, errors.New("invalid SNI name")
+					},
+				},
+				IdleTimeout:       30 * time.Second,
+				ReadHeaderTimeout: 20 * time.Second,
+				MaxHeaderBytes:    10 << 10,
+			}
+			errc <- hs.ListenAndServeTLS("", "")
 		}()
 	}
 	log.Fatal(<-errc)
@@ -112,13 +135,13 @@ func tailscaleIP(who *apitype.WhoIsResponse) string {
 		return ""
 	}
 	for _, nodeIP := range who.Node.Addresses {
-		if nodeIP.IP().Is4() && nodeIP.IsSingleIP() {
-			return nodeIP.IP().String()
+		if nodeIP.Addr().Is4() && nodeIP.IsSingleIP() {
+			return nodeIP.Addr().String()
 		}
 	}
 	for _, nodeIP := range who.Node.Addresses {
 		if nodeIP.IsSingleIP() {
-			return nodeIP.IP().String()
+			return nodeIP.Addr().String()
 		}
 	}
 	return ""
@@ -127,8 +150,9 @@ func tailscaleIP(who *apitype.WhoIsResponse) string {
 func root(w http.ResponseWriter, r *http.Request) {
 	if r.TLS == nil && *httpsAddr != "" {
 		host := r.Host
-		if strings.Contains(r.Host, "100.101.102.103") {
-			host = "hello.ipn.dev"
+		if strings.Contains(r.Host, "100.101.102.103") ||
+			strings.Contains(r.Host, "hello.ipn.dev") {
+			host = "hello.ts.net"
 		}
 		http.Redirect(w, r, "https://"+host, http.StatusFound)
 		return
@@ -137,6 +161,10 @@ func root(w http.ResponseWriter, r *http.Request) {
 		http.Redirect(w, r, "/", http.StatusFound)
 		return
 	}
+	if r.TLS != nil && *httpsAddr != "" && strings.Contains(r.Host, "hello.ipn.dev") {
+		http.Redirect(w, r, "https://hello.ts.net", http.StatusFound)
+		return
+	}
 	tmpl, err := getTmpl()
 	if err != nil {
 		w.Header().Set("Content-Type", "text/plain")
@@ -168,7 +196,7 @@ func root(w http.ResponseWriter, r *http.Request) {
 			LoginName:     who.UserProfile.LoginName,
 			ProfilePicURL: who.UserProfile.ProfilePicURL,
 			MachineName:   firstLabel(who.Node.ComputedName),
-			MachineOS:     who.Node.Hostinfo.OS,
+			MachineOS:     who.Node.Hostinfo.OS(),
 			IP:            tailscaleIP(who),
 		}
 	}
@@ -178,8 +206,6 @@ func root(w http.ResponseWriter, r *http.Request) {
 
 // firstLabel s up until the first period, if any.
 func firstLabel(s string) string {
-	if i := strings.Index(s, "."); i != -1 {
-		return s[:i]
-	}
+	s, _, _ = strings.Cut(s, ".")
 	return s
 }

cmd/microproxy/microproxy.go

@@ -1,173 +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.
-
-// 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 := http.NewServeMux()
-	tsweb.Debugger(mux) // registers /debug/*
-	mux.Handle("/metrics", tsweb.Protected(proxy))
-	mux.Handle("/varz", tsweb.Protected(tsweb.StdHandler(&goVarsHandler{*goVarsURL}, tsweb.HandlerOptions{
-		Quiet200s: true,
-		Logf:      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
-}

cmd/mkpkg/main.go

@@ -6,6 +6,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
 	"os"
@@ -14,7 +15,6 @@ import (
 	"github.com/goreleaser/nfpm"
 	_ "github.com/goreleaser/nfpm/deb"
 	_ "github.com/goreleaser/nfpm/rpm"
-	"github.com/pborman/getopt"
 )
 
 // parseFiles parses a comma-separated list of colon-separated pairs
@@ -44,19 +44,21 @@ func parseEmptyDirs(s string) []string {
 }
 
 func main() {
-	out := getopt.StringLong("out", 'o', "", "output file to write")
-	goarch := getopt.StringLong("arch", 'a', "amd64", "GOARCH this package is for")
-	pkgType := getopt.StringLong("type", 't', "deb", "type of package to build (deb or rpm)")
-	files := getopt.StringLong("files", 'F', "", "comma-separated list of files in src:dst form")
-	configFiles := getopt.StringLong("configs", 'C', "", "like --files, but for files marked as user-editable config files")
-	emptyDirs := getopt.StringLong("emptydirs", 'E', "", "comma-separated list of empty directories")
-	version := getopt.StringLong("version", 0, "0.0.0", "version of the package")
-	postinst := getopt.StringLong("postinst", 0, "", "debian postinst script path")
-	prerm := getopt.StringLong("prerm", 0, "", "debian prerm script path")
-	postrm := getopt.StringLong("postrm", 0, "", "debian postrm script path")
-	replaces := getopt.StringLong("replaces", 0, "", "package which this package replaces, if any")
-	depends := getopt.StringLong("depends", 0, "", "comma-separated list of packages this package depends on")
-	getopt.Parse()
+	out := flag.String("out", "", "output file to write")
+	name := flag.String("name", "tailscale", "package name")
+	description := flag.String("description", "The easiest, most secure, cross platform way to use WireGuard + oauth2 + 2FA/SSO", "package description")
+	goarch := flag.String("arch", "amd64", "GOARCH this package is for")
+	pkgType := flag.String("type", "deb", "type of package to build (deb or rpm)")
+	files := flag.String("files", "", "comma-separated list of files in src:dst form")
+	configFiles := flag.String("configs", "", "like --files, but for files marked as user-editable config files")
+	emptyDirs := flag.String("emptydirs", "", "comma-separated list of empty directories")
+	version := flag.String("version", "0.0.0", "version of the package")
+	postinst := flag.String("postinst", "", "debian postinst script path")
+	prerm := flag.String("prerm", "", "debian prerm script path")
+	postrm := flag.String("postrm", "", "debian postrm script path")
+	replaces := flag.String("replaces", "", "package which this package replaces, if any")
+	depends := flag.String("depends", "", "comma-separated list of packages this package depends on")
+	flag.Parse()
 
 	filesMap, err := parseFiles(*files)
 	if err != nil {
@@ -68,12 +70,12 @@ func main() {
 	}
 	emptyDirList := parseEmptyDirs(*emptyDirs)
 	info := nfpm.WithDefaults(&nfpm.Info{
-		Name:        "tailscale",
+		Name:        *name,
 		Arch:        *goarch,
 		Platform:    "linux",
 		Version:     *version,
 		Maintainer:  "Tailscale Inc <info@tailscale.com>",
-		Description: "The easiest, most secure, cross platform way to use WireGuard + oauth2 + 2FA/SSO",
+		Description: *description,
 		Homepage:    "https://www.tailscale.com",
 		License:     "MIT",
 		Overridables: nfpm.Overridables{

cmd/nginx-auth/.gitignore

@@ -0,0 +1,4 @@
+nga.sock
+*.deb
+*.rpm
+tailscale.nginx-auth

cmd/nginx-auth/README.md

@@ -0,0 +1,157 @@
+# nginx-auth
+
+This is a tool that allows users to use Tailscale Whois authentication with
+NGINX as a reverse proxy. This allows users that already have a bunch of
+services hosted on an internal NGINX server to point those domains to the
+Tailscale IP of the NGINX server and then seamlessly use Tailscale for
+authentication.
+
+Many thanks to [@zrail](https://twitter.com/zrail/status/1511788463586222087) on
+Twitter for introducing the basic idea and offering some sample code. This
+program is based on that sample code with security enhancements. Namely:
+
+* This listens over a UNIX socket instead of a TCP socket, to prevent
+  leakage to the network
+* This uses systemd socket activation so that systemd owns the socket
+  and can then lock down the service to the bare minimum required to do
+  its job without having to worry about dropping permissions
+* This provides additional information in HTTP response headers that can
+  be useful for integrating with various services
+
+## Configuration
+
+In order to protect a service with this tool, do the following in the respective
+`server` block:
+
+Create an authentication location with the `internal` flag set:
+
+```nginx
+location /auth {
+  internal;
+
+  proxy_pass http://unix:/run/tailscale.nginx-auth.sock;
+  proxy_pass_request_body off;
+
+  proxy_set_header Host $http_host;
+  proxy_set_header Remote-Addr $remote_addr;
+  proxy_set_header Remote-Port $remote_port;
+  proxy_set_header Original-URI $request_uri;
+}
+```
+
+Then add the following to the `location /` block:
+
+```
+auth_request /auth;
+auth_request_set $auth_user $upstream_http_tailscale_user;
+auth_request_set $auth_name $upstream_http_tailscale_name;
+auth_request_set $auth_login $upstream_http_tailscale_login;
+auth_request_set $auth_tailnet $upstream_http_tailscale_tailnet;
+auth_request_set $auth_profile_picture $upstream_http_tailscale_profile_picture;
+
+proxy_set_header X-Webauth-User "$auth_user";
+proxy_set_header X-Webauth-Name "$auth_name";
+proxy_set_header X-Webauth-Login "$auth_login";
+proxy_set_header X-Webauth-Tailnet "$auth_tailnet";
+proxy_set_header X-Webauth-Profile-Picture "$auth_profile_picture";
+```
+
+When this configuration is used with a Go HTTP handler such as this:
+
+```go
+http.HandlerFunc(func (w http.ResponseWriter, r *http.Request) {
+	e := json.NewEncoder(w)
+	e.SetIndent("", "  ")
+	e.Encode(r.Header)
+})
+```
+
+You will get output like this:
+
+```json
+{
+  "Accept": [
+    "*/*"
+  ],
+  "Connection": [
+    "upgrade"
+  ],
+  "User-Agent": [
+    "curl/7.82.0"
+  ],
+  "X-Webauth-Login": [
+    "Xe"
+  ],
+  "X-Webauth-Name": [
+    "Xe Iaso"
+  ],
+  "X-Webauth-Profile-Picture": [
+    "https://avatars.githubusercontent.com/u/529003?v=4"
+  ],
+  "X-Webauth-Tailnet": [
+    "cetacean.org.github"
+  ]
+  "X-Webauth-User": [
+    "Xe@github"
+  ]
+}
+```
+
+## Headers
+
+The authentication service provides the following headers to decorate your
+proxied requests:
+
+| Header                      | Example Value                                                      | Description                                                                   |
+| :------                     | :--------------                                                    | :----------                                                                   |
+| `Tailscale-User`            | `azurediamond@hunter2.net`                                         | The Tailscale username the remote machine is logged in as in user@host form   |
+| `Tailscale-Login`           | `azurediamond`                                                     | The user portion of the Tailscale username the remote machine is logged in as |
+| `Tailscale-Name`            | `Azure Diamond`                                                    | The "real name" of the Tailscale user the machine is logged in as             |
+| `Tailscale-Profile-Picture` | `https://i.kym-cdn.com/photos/images/newsfeed/001/065/963/ae0.png` | The profile picture provided by the Identity Provider your tailnet uses       |
+| `Tailscale-Tailnet`          | `hunter2.net`                                       | The tailnet name                                                              |
+
+Most of the time you can set `X-Webauth-User` to the contents of the
+`Tailscale-User` header, but some services may not accept a username with an `@`
+symbol in it. If this is the case, set `X-Webauth-User` to the `Tailscale-Login`
+header.
+
+The `Tailscale-Tailnet` header can help you identify which tailnet the session
+is coming from. If you are using node sharing, this can help you make sure that
+you aren't giving administrative access to people outside your tailnet.
+
+### Allow Requests From Only One Tailnet
+
+If you want to prevent node sharing from allowing users to access a service, add
+the `Expected-Tailnet` header to your auth request:
+
+```nginx
+location /auth {
+  # ...
+  proxy_set_header Expected-Tailnet "tailscale.com";
+}
+```
+
+If a user from a different tailnet tries to use that service, this will return a
+generic "forbidden" error page:
+
+```html
+<html>
+<head><title>403 Forbidden</title></head>
+<body>
+<center><h1>403 Forbidden</h1></center>
+<hr><center>nginx/1.18.0 (Ubuntu)</center>
+</body>
+</html>
+```
+
+## Building
+
+Install `cmd/mkpkg`:
+
+```
+cd .. && go install ./mkpkg
+```
+
+Then run `./mkdeb.sh`. It will emit a `.deb` and `.rpm` package for amd64
+machines (Linux uname flag: `x86_64`). You can add these to your deployment
+methods as you see fit.

cmd/nginx-auth/deb/postinst.sh

@@ -0,0 +1,14 @@
+if [ "$1" = "configure" ] || [ "$1" = "abort-upgrade" ] || [ "$1" = "abort-deconfigure" ] || [ "$1" = "abort-remove" ] ; then
+	  deb-systemd-helper unmask 'tailscale.nginx-auth.socket' >/dev/null || true
+	  if deb-systemd-helper --quiet was-enabled 'tailscale.nginx-auth.socket'; then
+		    deb-systemd-helper enable 'tailscale.nginx-auth.socket' >/dev/null || true
+	  else
+		    deb-systemd-helper update-state 'tailscale.nginx-auth.socket' >/dev/null || true
+	  fi
+
+    if systemctl is-active tailscale.nginx-auth.socket >/dev/null; then
+        systemctl --system daemon-reload >/dev/null || true
+        deb-systemd-invoke stop 'tailscale.nginx-auth.service' >/dev/null || true
+        deb-systemd-invoke restart 'tailscale.nginx-auth.socket' >/dev/null || true
+    fi
+fi

cmd/nginx-auth/deb/postrm.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+set -e
+if [ -d /run/systemd/system ] ; then
+	  systemctl --system daemon-reload >/dev/null || true
+fi
+
+if [ -x "/usr/bin/deb-systemd-helper" ]; then
+    if [ "$1" = "remove" ]; then
+		    deb-systemd-helper mask 'tailscale.nginx-auth.socket' >/dev/null || true
+		    deb-systemd-helper mask 'tailscale.nginx-auth.service' >/dev/null || true
+	  fi
+
+    if [ "$1" = "purge" ]; then
+		    deb-systemd-helper purge 'tailscale.nginx-auth.socket' >/dev/null || true
+		    deb-systemd-helper unmask 'tailscale.nginx-auth.socket' >/dev/null || true
+		    deb-systemd-helper purge 'tailscale.nginx-auth.service' >/dev/null || true
+		    deb-systemd-helper unmask 'tailscale.nginx-auth.service' >/dev/null || true
+	  fi
+fi

cmd/nginx-auth/deb/prerm.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+set -e
+if [ "$1" = "remove" ]; then
+	  if [ -d /run/systemd/system ]; then
+		    deb-systemd-invoke stop 'tailscale.nginx-auth.service' >/dev/null || true
+		    deb-systemd-invoke stop 'tailscale.nginx-auth.socket' >/dev/null || true
+	  fi
+fi

cmd/nginx-auth/mkdeb.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+set -e
+
+CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -o tailscale.nginx-auth .
+
+VERSION=0.1.1
+
+mkpkg \
+    --out=tailscale-nginx-auth-${VERSION}-amd64.deb \
+    --name=tailscale-nginx-auth \
+    --version=${VERSION} \
+    --type=deb \
+    --arch=amd64 \
+    --postinst=deb/postinst.sh \
+    --postrm=deb/postrm.sh \
+    --prerm=deb/prerm.sh \
+    --description="Tailscale NGINX authentication protocol handler" \
+    --files=./tailscale.nginx-auth:/usr/sbin/tailscale.nginx-auth,./tailscale.nginx-auth.socket:/lib/systemd/system/tailscale.nginx-auth.socket,./tailscale.nginx-auth.service:/lib/systemd/system/tailscale.nginx-auth.service,./README.md:/usr/share/tailscale/nginx-auth/README.md
+
+mkpkg \
+    --out=tailscale-nginx-auth-${VERSION}-amd64.rpm \
+    --name=tailscale-nginx-auth \
+    --version=${VERSION} \
+    --type=rpm \
+    --arch=amd64 \
+    --postinst=rpm/postinst.sh \
+    --postrm=rpm/postrm.sh \
+    --prerm=rpm/prerm.sh \
+    --description="Tailscale NGINX authentication protocol handler" \
+    --files=./tailscale.nginx-auth:/usr/sbin/tailscale.nginx-auth,./tailscale.nginx-auth.socket:/lib/systemd/system/tailscale.nginx-auth.socket,./tailscale.nginx-auth.service:/lib/systemd/system/tailscale.nginx-auth.service,./README.md:/usr/share/tailscale/nginx-auth/README.md

cmd/nginx-auth/nginx-auth.go

@@ -0,0 +1,129 @@
+// Copyright (c) 2022 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
+
+// Command nginx-auth is a tool that allows users to use Tailscale Whois
+// authentication with NGINX as a reverse proxy. This allows users that
+// already have a bunch of services hosted on an internal NGINX server
+// to point those domains to the Tailscale IP of the NGINX server and
+// then seamlessly use Tailscale for authentication.
+package main
+
+import (
+	"flag"
+	"log"
+	"net"
+	"net/http"
+	"net/netip"
+	"net/url"
+	"os"
+	"strings"
+
+	"github.com/coreos/go-systemd/activation"
+	"tailscale.com/client/tailscale"
+)
+
+var (
+	sockPath = flag.String("sockpath", "", "the filesystem path for the unix socket this service exposes")
+)
+
+func main() {
+	flag.Parse()
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		remoteHost := r.Header.Get("Remote-Addr")
+		remotePort := r.Header.Get("Remote-Port")
+		if remoteHost == "" || remotePort == "" {
+			w.WriteHeader(http.StatusBadRequest)
+			log.Println("set Remote-Addr to $remote_addr and Remote-Port to $remote_port in your nginx config")
+			return
+		}
+
+		remoteAddrStr := net.JoinHostPort(remoteHost, remotePort)
+		remoteAddr, err := netip.ParseAddrPort(remoteAddrStr)
+		if err != nil {
+			w.WriteHeader(http.StatusUnauthorized)
+			log.Printf("remote address and port are not valid: %v", err)
+			return
+		}
+
+		info, err := tailscale.WhoIs(r.Context(), remoteAddr.String())
+		if err != nil {
+			w.WriteHeader(http.StatusUnauthorized)
+			log.Printf("can't look up %s: %v", remoteAddr, err)
+			return
+		}
+
+		if len(info.Node.Tags) != 0 {
+			w.WriteHeader(http.StatusForbidden)
+			log.Printf("node %s is tagged", info.Node.Hostinfo.Hostname())
+			return
+		}
+
+		// tailnet of connected node. When accessing shared nodes, this
+		// will be empty because the tailnet of the sharee is not exposed.
+		var tailnet string
+
+		if !info.Node.Hostinfo.ShareeNode() {
+			var ok bool
+			_, tailnet, ok = strings.Cut(info.Node.Name, info.Node.ComputedName+".")
+			if !ok {
+				w.WriteHeader(http.StatusUnauthorized)
+				log.Printf("can't extract tailnet name from hostname %q", info.Node.Name)
+				return
+			}
+			tailnet = strings.TrimSuffix(tailnet, ".beta.tailscale.net")
+		}
+
+		if expectedTailnet := r.Header.Get("Expected-Tailnet"); expectedTailnet != "" && expectedTailnet != tailnet {
+			w.WriteHeader(http.StatusForbidden)
+			log.Printf("user is part of tailnet %s, wanted: %s", tailnet, url.QueryEscape(expectedTailnet))
+			return
+		}
+
+		h := w.Header()
+		h.Set("Tailscale-Login", strings.Split(info.UserProfile.LoginName, "@")[0])
+		h.Set("Tailscale-User", info.UserProfile.LoginName)
+		h.Set("Tailscale-Name", info.UserProfile.DisplayName)
+		h.Set("Tailscale-Profile-Picture", info.UserProfile.ProfilePicURL)
+		h.Set("Tailscale-Tailnet", tailnet)
+		w.WriteHeader(http.StatusNoContent)
+	})
+
+	if *sockPath != "" {
+		_ = os.Remove(*sockPath) // ignore error, this file may not already exist
+		ln, err := net.Listen("unix", *sockPath)
+		if err != nil {
+			log.Fatalf("can't listen on %s: %v", *sockPath, err)
+		}
+		defer ln.Close()
+
+		log.Printf("listening on %s", *sockPath)
+		log.Fatal(http.Serve(ln, mux))
+	}
+
+	listeners, err := activation.Listeners()
+	if err != nil {
+		log.Fatalf("no sockets passed to this service with systemd: %v", err)
+	}
+
+	// NOTE(Xe): normally you'd want to make a waitgroup here and then register
+	// each listener with it. In this case I want this to blow up horribly if
+	// any of the listeners stop working. systemd will restart it due to the
+	// socket activation at play.
+	//
+	// TL;DR: Let it crash, it will come back
+	for _, ln := range listeners {
+		go func(ln net.Listener) {
+			log.Printf("listening on %s", ln.Addr())
+			log.Fatal(http.Serve(ln, mux))
+		}(ln)
+	}
+
+	for {
+		select {}
+	}
+}

cmd/nginx-auth/rpm/postrm.sh

@@ -0,0 +1,9 @@
+# $1 == 0 for uninstallation.
+# $1 == 1 for removing old package during upgrade.
+
+systemctl daemon-reload >/dev/null 2>&1 || :
+if [ $1 -ge 1 ] ; then
+    # Package upgrade, not uninstall
+    systemctl stop tailscale.nginx-auth.service >/dev/null 2>&1 || :
+    systemctl try-restart tailscale.nginx-auth.socket >/dev/null 2>&1 || :
+fi

cmd/nginx-auth/rpm/prerm.sh

@@ -0,0 +1,9 @@
+# $1 == 0 for uninstallation.
+# $1 == 1 for removing old package during upgrade.
+
+if [ $1 -eq 0 ] ; then
+    # Package removal, not upgrade
+    systemctl --no-reload disable tailscale.nginx-auth.socket > /dev/null 2>&1 || :
+    systemctl stop tailscale.nginx-auth.socket > /dev/null 2>&1 || :
+    systemctl stop tailscale.nginx-auth.service > /dev/null 2>&1 || :
+fi

cmd/nginx-auth/tailscale.nginx-auth.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Tailscale NGINX Authentication service
+After=nginx.service
+Wants=nginx.service
+
+[Service]
+ExecStart=/usr/sbin/tailscale.nginx-auth
+DynamicUser=yes
+
+[Install]
+WantedBy=default.target

cmd/nginx-auth/tailscale.nginx-auth.socket

@@ -0,0 +1,9 @@
+[Unit]
+Description=Tailscale NGINX Authentication socket
+PartOf=tailscale.nginx-auth.service
+
+[Socket]
+ListenStream=/var/run/tailscale.nginx-auth.sock
+
+[Install]
+WantedBy=sockets.target

cmd/printdep/printdep.go

@@ -0,0 +1,51 @@
+// 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 printdep command is a build system tool for printing out information
+// about dependencies.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"runtime"
+	"strings"
+
+	ts "tailscale.com"
+)
+
+var (
+	goToolchain    = flag.Bool("go", false, "print the supported Go toolchain git hash (a github.com/tailscale/go commit)")
+	goToolchainURL = flag.Bool("go-url", false, "print the URL to the tarball of the Tailscale Go toolchain")
+	alpine         = flag.Bool("alpine", false, "print the tag of alpine docker image")
+)
+
+func main() {
+	flag.Parse()
+	if *alpine {
+		fmt.Println(strings.TrimSpace(ts.AlpineDockerTag))
+		return
+	}
+	if *goToolchain {
+		fmt.Println(strings.TrimSpace(ts.GoToolchainRev))
+	}
+	if *goToolchainURL {
+		var suffix string
+		switch runtime.GOARCH {
+		case "amd64":
+			// None
+		case "arm64":
+			suffix = "-" + runtime.GOARCH
+		default:
+			log.Fatalf("unsupported GOARCH %q", runtime.GOARCH)
+		}
+		switch runtime.GOOS {
+		case "linux", "darwin":
+		default:
+			log.Fatalf("unsupported GOOS %q", runtime.GOOS)
+		}
+		fmt.Printf("https://github.com/tailscale/go/releases/download/build-%s/%s%s.tar.gz\n", strings.TrimSpace(ts.GoToolchainRev), runtime.GOOS, suffix)
+	}
+}

cmd/proxy-to-grafana/proxy-to-grafana.go

@@ -0,0 +1,159 @@
+// Copyright (c) 2022 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.
+
+// proxy-to-grafana is a reverse proxy which identifies users based on their
+// originating Tailscale identity and maps them to corresponding Grafana
+// users, creating them if needed.
+//
+// It uses Grafana's AuthProxy feature:
+// https://grafana.com/docs/grafana/latest/auth/auth-proxy/
+//
+// Set the TS_AUTHKEY environment variable to have this server automatically
+// join your tailnet, or look for the logged auth link on first start.
+//
+// Use this Grafana configuration to enable the auth proxy:
+//
+//	[auth.proxy]
+//	enabled = true
+//	header_name = X-WEBAUTH-USER
+//	header_property = username
+//	auto_sign_up = true
+//	whitelist = 127.0.0.1
+//	headers = Name:X-WEBAUTH-NAME
+//	enable_login_token = true
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"strings"
+	"time"
+
+	"tailscale.com/client/tailscale"
+	"tailscale.com/tailcfg"
+	"tailscale.com/tsnet"
+)
+
+var (
+	hostname     = flag.String("hostname", "", "Tailscale hostname to serve on, used as the base name for MagicDNS or subdomain in your domain alias for HTTPS.")
+	backendAddr  = flag.String("backend-addr", "", "Address of the Grafana server served over HTTP, in host:port format. Typically localhost:nnnn.")
+	tailscaleDir = flag.String("state-dir", "./", "Alternate directory to use for Tailscale state storage. If empty, a default is used.")
+	useHTTPS     = flag.Bool("use-https", false, "Serve over HTTPS via your *.ts.net subdomain if enabled in Tailscale admin.")
+)
+
+func main() {
+	flag.Parse()
+	if *hostname == "" || strings.Contains(*hostname, ".") {
+		log.Fatal("missing or invalid --hostname")
+	}
+	if *backendAddr == "" {
+		log.Fatal("missing --backend-addr")
+	}
+	ts := &tsnet.Server{
+		Dir:      *tailscaleDir,
+		Hostname: *hostname,
+	}
+
+	// TODO(bradfitz,maisem): move this to a method on tsnet.Server probably.
+	if err := ts.Start(); err != nil {
+		log.Fatalf("Error starting tsnet.Server: %v", err)
+	}
+	localClient, _ := ts.LocalClient()
+
+	url, err := url.Parse(fmt.Sprintf("http://%s", *backendAddr))
+	if err != nil {
+		log.Fatalf("couldn't parse backend address: %v", err)
+	}
+
+	proxy := httputil.NewSingleHostReverseProxy(url)
+	originalDirector := proxy.Director
+	proxy.Director = func(req *http.Request) {
+		originalDirector(req)
+		modifyRequest(req, localClient)
+	}
+
+	var ln net.Listener
+	if *useHTTPS {
+		ln, err = ts.Listen("tcp", ":443")
+		ln = tls.NewListener(ln, &tls.Config{
+			GetCertificate: localClient.GetCertificate,
+		})
+
+		go func() {
+			// wait for tailscale to start before trying to fetch cert names
+			for i := 0; i < 60; i++ {
+				st, err := localClient.Status(context.Background())
+				if err != nil {
+					log.Printf("error retrieving tailscale status; retrying: %v", err)
+				} else {
+					log.Printf("tailscale status: %v", st.BackendState)
+					if st.BackendState == "Running" {
+						break
+					}
+				}
+				time.Sleep(time.Second)
+			}
+
+			l80, err := ts.Listen("tcp", ":80")
+			if err != nil {
+				log.Fatal(err)
+			}
+			name, ok := localClient.ExpandSNIName(context.Background(), *hostname)
+			if !ok {
+				log.Fatalf("can't get hostname for https redirect")
+			}
+			if err := http.Serve(l80, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				http.Redirect(w, r, fmt.Sprintf("https://%s", name), http.StatusMovedPermanently)
+			})); err != nil {
+				log.Fatal(err)
+			}
+		}()
+	} else {
+		ln, err = ts.Listen("tcp", ":80")
+	}
+	if err != nil {
+		log.Fatal(err)
+	}
+	log.Printf("proxy-to-grafana running at %v, proxying to %v", ln.Addr(), *backendAddr)
+	log.Fatal(http.Serve(ln, proxy))
+}
+
+func modifyRequest(req *http.Request, localClient *tailscale.LocalClient) {
+	// with enable_login_token set to true, we get a cookie that handles
+	// auth for paths that are not /login
+	if req.URL.Path != "/login" {
+		return
+	}
+
+	user, err := getTailscaleUser(req.Context(), localClient, req.RemoteAddr)
+	if err != nil {
+		log.Printf("error getting Tailscale user: %v", err)
+		return
+	}
+
+	req.Header.Set("X-Webauth-User", user.LoginName)
+	req.Header.Set("X-Webauth-Name", user.DisplayName)
+}
+
+func getTailscaleUser(ctx context.Context, localClient *tailscale.LocalClient, ipPort string) (*tailcfg.UserProfile, error) {
+	whois, err := localClient.WhoIs(ctx, ipPort)
+	if err != nil {
+		return nil, fmt.Errorf("failed to identify remote host: %w", err)
+	}
+	if len(whois.Node.Tags) != 0 {
+		return nil, fmt.Errorf("tagged nodes are not users")
+	}
+	if whois.UserProfile == nil || whois.UserProfile.LoginName == "" {
+		return nil, fmt.Errorf("failed to identify remote user")
+	}
+
+	return whois.UserProfile, nil
+}

cmd/speedtest/speedtest.go

@@ -23,7 +23,7 @@ import (
 	"text/tabwriter"
 	"time"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
+	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/net/speedtest"
 )
 

cmd/tailscale/cli/bugreport.go

@@ -7,10 +7,8 @@ package cli
 import (
 	"context"
 	"errors"
-	"fmt"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/client/tailscale"
+	"github.com/peterbourgon/ff/v3/ffcli"
 )
 
 var bugReportCmd = &ffcli.Command{
@@ -29,10 +27,10 @@ func runBugReport(ctx context.Context, args []string) error {
 	default:
 		return errors.New("unknown argumets")
 	}
-	logMarker, err := tailscale.BugReport(ctx, note)
+	logMarker, err := localClient.BugReport(ctx, note)
 	if err != nil {
 		return err
 	}
-	fmt.Println(logMarker)
+	outln(logMarker)
 	return nil
 }

cmd/tailscale/cli/cert.go

@@ -0,0 +1,151 @@
+// 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/v3/ffcli"
+	"tailscale.com/atomicfile"
+	"tailscale.com/ipn"
+	"tailscale.com/version"
+)
+
+var certCmd = &ffcli.Command{
+	Name:       "cert",
+	Exec:       runCert,
+	ShortHelp:  "get TLS certs",
+	ShortUsage: "cert [flags] <domain>",
+	FlagSet: (func() *flag.FlagSet {
+		fs := newFlagSet("cert")
+		fs.StringVar(&certArgs.certFile, "cert-file", "", "output cert file or \"-\" for stdout; defaults to DOMAIN.crt if --cert-file and --key-file are both unset")
+		fs.StringVar(&certArgs.keyFile, "key-file", "", "output key file or \"-\" for stdout; defaults to DOMAIN.key if --cert-file and --key-file are both unset")
+		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: localClient.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 := localClient.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 {
+		var hint bytes.Buffer
+		if st, err := localClient.Status(ctx); err == nil {
+			if st.BackendState != ipn.Running.String() {
+				fmt.Fprintf(&hint, "\nTailscale is not running.\n")
+			} else if len(st.CertDomains) == 0 {
+				fmt.Fprintf(&hint, "\nHTTPS cert support is not enabled/configured for your tailnet.\n")
+			} else if len(st.CertDomains) == 1 {
+				fmt.Fprintf(&hint, "\nFor domain, use %q.\n", st.CertDomains[0])
+			} else {
+				fmt.Fprintf(&hint, "\nValid domain options: %q.\n", st.CertDomains)
+			}
+		}
+		return fmt.Errorf("Usage: tailscale cert [flags] <domain>%s", hint.Bytes())
+	}
+	domain := args[0]
+
+	printf := func(format string, a ...any) {
+		printf(format, a...)
+	}
+	if certArgs.certFile == "-" || certArgs.keyFile == "-" {
+		printf = log.Printf
+		log.SetFlags(0)
+	}
+	if certArgs.certFile == "" && certArgs.keyFile == "" {
+		certArgs.certFile = domain + ".crt"
+		certArgs.keyFile = domain + ".key"
+	}
+	certPEM, keyPEM, err := localClient.CertPair(ctx, domain)
+	if err != nil {
+		return err
+	}
+	needMacWarning := version.IsSandboxedMacOS()
+	macWarn := func() {
+		if !needMacWarning {
+			return
+		}
+		needMacWarning = false
+		dir := "io.tailscale.ipn.macos"
+		if version.IsMacSysExt() {
+			dir = "io.tailscale.ipn.macsys"
+		}
+		printf("Warning: the macOS CLI runs in a sandbox; this binary's filesystem writes go to $HOME/Library/Containers/%s/Data\n", dir)
+	}
+	if certArgs.certFile != "" {
+		certChanged, err := writeIfChanged(certArgs.certFile, certPEM, 0644)
+		if err != nil {
+			return err
+		}
+		if certArgs.certFile != "-" {
+			macWarn()
+			if certChanged {
+				printf("Wrote public cert to %v\n", certArgs.certFile)
+			} else {
+				printf("Public cert unchanged at %v\n", certArgs.certFile)
+			}
+		}
+	}
+	if certArgs.keyFile != "" {
+		keyChanged, err := writeIfChanged(certArgs.keyFile, keyPEM, 0600)
+		if err != nil {
+			return err
+		}
+		if certArgs.keyFile != "-" {
+			macWarn()
+			if keyChanged {
+				printf("Wrote private key to %v\n", certArgs.keyFile)
+			} else {
+				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 filename == "-" {
+		Stdout.Write(contents)
+		return false, nil
+	}
+	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/cli.go

@@ -19,17 +19,35 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"syscall"
 	"text/tabwriter"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
+	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/client/tailscale"
+	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/paths"
 	"tailscale.com/safesocket"
-	"tailscale.com/syncs"
+	"tailscale.com/version/distro"
 )
 
+var Stderr io.Writer = os.Stderr
+var Stdout io.Writer = os.Stdout
+
+func printf(format string, a ...any) {
+	fmt.Fprintf(Stdout, format, a...)
+}
+
+// outln is like fmt.Println in the common case, except when Stdout is
+// changed (as in js/wasm).
+//
+// It's not named println because that looks like the Go built-in
+// which goes to stderr and formats slightly differently.
+func outln(a ...any) {
+	fmt.Fprintln(Stdout, a...)
+}
+
 // ActLikeCLI reports whether a GUI application should act like the
 // CLI based on os.Args, GOOS, the context the process is running in
 // (pty, parent PID), etc.
@@ -76,13 +94,54 @@ func ActLikeCLI() bool {
 	return false
 }
 
+func newFlagSet(name string) *flag.FlagSet {
+	onError := flag.ExitOnError
+	if runtime.GOOS == "js" {
+		onError = flag.ContinueOnError
+	}
+	fs := flag.NewFlagSet(name, onError)
+	fs.SetOutput(Stderr)
+	return fs
+}
+
+// CleanUpArgs rewrites command line arguments for simplicity and backwards compatibility.
+// In particular, it rewrites --authkey to --auth-key.
+func CleanUpArgs(args []string) []string {
+	out := make([]string, 0, len(args))
+	for _, arg := range args {
+		// Rewrite --authkey to --auth-key, and --authkey=x to --auth-key=x,
+		// and the same for the -authkey variant.
+		switch {
+		case arg == "--authkey", arg == "-authkey":
+			arg = "--auth-key"
+		case strings.HasPrefix(arg, "--authkey="), strings.HasPrefix(arg, "-authkey="):
+			arg = strings.TrimLeft(arg, "-")
+			arg = strings.TrimPrefix(arg, "authkey=")
+			arg = "--auth-key=" + arg
+		}
+		out = append(out, arg)
+	}
+	return out
+}
+
+var localClient tailscale.LocalClient
+
 // Run runs the CLI. The args do not include the binary name.
-func Run(args []string) error {
+func Run(args []string) (err error) {
+	args = CleanUpArgs(args)
+
 	if len(args) == 1 && (args[0] == "-V" || args[0] == "--version") {
 		args = []string{"version"}
 	}
 
-	rootfs := flag.NewFlagSet("tailscale", flag.ExitOnError)
+	var warnOnce sync.Once
+	tailscale.SetVersionMismatchHandler(func(clientVer, serverVer string) {
+		warnOnce.Do(func() {
+			fmt.Fprintf(Stderr, "Warning: client version %q != tailscaled server version %q\n", clientVer, serverVer)
+		})
+	})
+
+	rootfs := newFlagSet("tailscale")
 	rootfs.StringVar(&rootArgs.socket, "socket", paths.DefaultTailscaledSocket(), "path to tailscaled's unix socket")
 
 	rootCmd := &ffcli.Command{
@@ -103,10 +162,15 @@ change in the future.
 			ipCmd,
 			statusCmd,
 			pingCmd,
+			ncCmd,
+			sshCmd,
 			versionCmd,
 			webCmd,
 			fileCmd,
 			bugReportCmd,
+			certCmd,
+			netlockCmd,
+			licensesCmd,
 		},
 		FlagSet:   rootfs,
 		Exec:      func(context.Context, []string) error { return flag.ErrHelp },
@@ -115,38 +179,61 @@ change in the future.
 	for _, c := range rootCmd.Subcommands {
 		c.UsageFunc = usageFunc
 	}
+	if envknob.UseWIPCode() {
+		rootCmd.Subcommands = append(rootCmd.Subcommands, idTokenCmd)
+	}
 
 	// Don't advertise the debug command, but it exists.
 	if strSliceContains(args, "debug") {
 		rootCmd.Subcommands = append(rootCmd.Subcommands, debugCmd)
 	}
+	if runtime.GOOS == "linux" && distro.Get() == distro.Synology {
+		rootCmd.Subcommands = append(rootCmd.Subcommands, configureHostCmd)
+	}
 
 	if err := rootCmd.Parse(args); err != nil {
+		if errors.Is(err, flag.ErrHelp) {
+			return nil
+		}
 		return err
 	}
 
-	tailscale.TailscaledSocket = rootArgs.socket
+	localClient.Socket = rootArgs.socket
+	rootfs.Visit(func(f *flag.Flag) {
+		if f.Name == "socket" {
+			localClient.UseSocketOnly = true
+		}
+	})
 
-	err := rootCmd.Run(context.Background())
-	if err == flag.ErrHelp {
+	err = rootCmd.Run(context.Background())
+	if tailscale.IsAccessDeniedError(err) && os.Getuid() != 0 && runtime.GOOS != "windows" {
+		return fmt.Errorf("%v\n\nUse 'sudo tailscale %s' or 'tailscale up --operator=$USER' to not require root.", err, strings.Join(args, " "))
+	}
+	if errors.Is(err, flag.ErrHelp) {
 		return nil
 	}
 	return err
 }
 
-func fatalf(format string, a ...interface{}) {
+func fatalf(format string, a ...any) {
+	if Fatalf != nil {
+		Fatalf(format, a...)
+		return
+	}
 	log.SetFlags(0)
 	log.Fatalf(format, a...)
 }
 
+// Fatalf, if non-nil, is used instead of log.Fatalf.
+var Fatalf func(format string, a ...any)
+
 var rootArgs struct {
 	socket string
 }
 
-var gotSignal syncs.AtomicBool
-
 func connect(ctx context.Context) (net.Conn, *ipn.BackendClient, context.Context, context.CancelFunc) {
-	c, err := safesocket.Connect(rootArgs.socket, 41112)
+	s := safesocket.DefaultConnectionStrategy(rootArgs.socket)
+	c, err := safesocket.Connect(s)
 	if err != nil {
 		if runtime.GOOS != "windows" && rootArgs.socket == "" {
 			fatalf("--socket cannot be empty")
@@ -169,7 +256,6 @@ func connect(ctx context.Context) (net.Conn, *ipn.BackendClient, context.Context
 			signal.Reset(syscall.SIGINT, syscall.SIGTERM)
 			return
 		}
-		gotSignal.Set(true)
 		c.Close()
 		cancel()
 	}()

cmd/tailscale/cli/cli_test.go

@@ -9,16 +9,19 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"net/netip"
 	"reflect"
 	"strings"
 	"testing"
 
+	qt "github.com/frankban/quicktest"
 	"github.com/google/go-cmp/cmp"
-	"inet.af/netaddr"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/tstest"
 	"tailscale.com/types/persist"
 	"tailscale.com/types/preftype"
+	"tailscale.com/version/distro"
 )
 
 // geese is a collection of gooses. It need not be complete.
@@ -53,9 +56,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 		flags    []string // argv to be parsed by FlagSet
 		curPrefs *ipn.Prefs
 
-		curExitNodeIP netaddr.IP
+		curExitNodeIP netip.Addr
 		curUser       string // os.Getenv("USER") on the client side
 		goos          string // empty means "linux"
+		distro        distro.Distro
 
 		want string
 	}{
@@ -148,10 +152,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				AllowSingleHosts: true,
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("10.0.42.0/24"),
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("10.0.42.0/24"),
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
 				},
 			},
 			want: accidentalUpPrefix + " --advertise-routes=10.0.42.0/24 --advertise-exit-node",
@@ -164,10 +168,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				AllowSingleHosts: true,
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("10.0.42.0/24"),
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("10.0.42.0/24"),
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
 				},
 			},
 			want: "",
@@ -180,10 +184,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				AllowSingleHosts: true,
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("10.0.42.0/24"),
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("10.0.42.0/24"),
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
 				},
 			},
 			want: "",
@@ -208,8 +212,8 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
 
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("1.2.0.0/16"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("1.2.0.0/16"),
 				},
 			},
 			want: accidentalUpPrefix + " --advertise-exit-node --advertise-routes=1.2.0.0/16",
@@ -222,10 +226,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				AllowSingleHosts: true,
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
-					netaddr.MustParseIPPrefix("1.2.0.0/16"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
+					netip.MustParsePrefix("1.2.0.0/16"),
 				},
 			},
 			want: accidentalUpPrefix + " --advertise-exit-node --advertise-routes=1.2.0.0/16",
@@ -251,16 +255,16 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				ControlURL:       ipn.DefaultControlURL,
 				RouteAll:         true,
 				AllowSingleHosts: false,
-				ExitNodeIP:       netaddr.MustParseIP("100.64.5.6"),
+				ExitNodeIP:       netip.MustParseAddr("100.64.5.6"),
 				CorpDNS:          false,
 				ShieldsUp:        true,
 				AdvertiseTags:    []string{"tag:foo", "tag:bar"},
 				Hostname:         "myhostname",
 				ForceDaemon:      true,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("10.0.0.0/16"),
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("10.0.0.0/16"),
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
 				},
 				NetfilterMode: preftype.NetfilterNoDivert,
 				OperatorUser:  "alice",
@@ -276,14 +280,14 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				ControlURL:       ipn.DefaultControlURL,
 				RouteAll:         true,
 				AllowSingleHosts: false,
-				ExitNodeIP:       netaddr.MustParseIP("100.64.5.6"),
+				ExitNodeIP:       netip.MustParseAddr("100.64.5.6"),
 				CorpDNS:          false,
 				ShieldsUp:        true,
 				AdvertiseTags:    []string{"tag:foo", "tag:bar"},
 				Hostname:         "myhostname",
 				ForceDaemon:      true,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("10.0.0.0/16"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("10.0.0.0/16"),
 				},
 				NetfilterMode: preftype.NetfilterNoDivert,
 				OperatorUser:  "alice",
@@ -312,6 +316,7 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				ControlURL:       ipn.DefaultControlURL,
 				AllowSingleHosts: true,
 				CorpDNS:          true,
+				RouteAll:         true,
 
 				// And assume this no-op accidental pre-1.8 value:
 				NoSNAT: true,
@@ -328,7 +333,7 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 
 				NetfilterMode: preftype.NetfilterNoDivert, // we never had this bug, but pretend it got set non-zero on Windows somehow
 			},
-			goos: "windows",
+			goos: "openbsd",
 			want: "", // not an error
 		},
 		{
@@ -339,10 +344,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				AllowSingleHosts: true,
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
-					netaddr.MustParseIPPrefix("1.2.0.0/16"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
+					netip.MustParsePrefix("1.2.0.0/16"),
 				},
 			},
 			want: accidentalUpPrefix + " --operator=expbits --advertise-exit-node --advertise-routes=1.2.0.0/16",
@@ -355,10 +360,10 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				AllowSingleHosts: true,
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
-					netaddr.MustParseIPPrefix("1.2.0.0/16"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
+					netip.MustParsePrefix("1.2.0.0/16"),
 				},
 			},
 			want: accidentalUpPrefix + " --advertise-routes=1.2.0.0/16 --operator=expbits --advertise-exit-node",
@@ -375,7 +380,7 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 
 				Hostname: "foo",
 			},
-			want: accidentalUpPrefix + " --authkey=secretrand --force-reauth=false --reset --hostname=foo",
+			want: accidentalUpPrefix + " --auth-key=secretrand --force-reauth=false --reset --hostname=foo",
 		},
 		{
 			name:  "error_exit_node_omit_with_ip_pref",
@@ -386,14 +391,14 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 				CorpDNS:          true,
 				NetfilterMode:    preftype.NetfilterOn,
 
-				ExitNodeIP: netaddr.MustParseIP("100.64.5.4"),
+				ExitNodeIP: netip.MustParseAddr("100.64.5.4"),
 			},
 			want: accidentalUpPrefix + " --hostname=foo --exit-node=100.64.5.4",
 		},
 		{
 			name:          "error_exit_node_omit_with_id_pref",
 			flags:         []string{"--hostname=foo"},
-			curExitNodeIP: netaddr.MustParseIP("100.64.5.7"),
+			curExitNodeIP: netip.MustParseAddr("100.64.5.7"),
 			curPrefs: &ipn.Prefs{
 				ControlURL:       ipn.DefaultControlURL,
 				AllowSingleHosts: true,
@@ -404,6 +409,21 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 			},
 			want: accidentalUpPrefix + " --hostname=foo --exit-node=100.64.5.7",
 		},
+		{
+			name:          "error_exit_node_and_allow_lan_omit_with_id_pref", // Isue 3480
+			flags:         []string{"--hostname=foo"},
+			curExitNodeIP: netip.MustParseAddr("100.2.3.4"),
+			curPrefs: &ipn.Prefs{
+				ControlURL:       ipn.DefaultControlURL,
+				AllowSingleHosts: true,
+				CorpDNS:          true,
+				NetfilterMode:    preftype.NetfilterOn,
+
+				ExitNodeAllowLANAccess: true,
+				ExitNodeID:             "some_stable_id",
+			},
+			want: accidentalUpPrefix + " --hostname=foo --exit-node-allow-lan-access --exit-node=100.2.3.4",
+		},
 		{
 			name:  "ignore_login_server_synonym",
 			flags: []string{"--login-server=https://controlplane.tailscale.com"},
@@ -426,6 +446,38 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 			},
 			want: accidentalUpPrefix + " --netfilter-mode=off --accept-dns=false",
 		},
+		{
+			// Issue 3176: on Synology, don't require --accept-routes=false because user
+			// migth've had old an install, and we don't support --accept-routes anyway.
+			name:  "synology_permit_omit_accept_routes",
+			flags: []string{"--hostname=foo"},
+			curPrefs: &ipn.Prefs{
+				ControlURL:       "https://login.tailscale.com",
+				CorpDNS:          true,
+				AllowSingleHosts: true,
+				RouteAll:         true,
+				NetfilterMode:    preftype.NetfilterOn,
+			},
+			goos:   "linux",
+			distro: distro.Synology,
+			want:   "",
+		},
+		{
+			// Same test case as "synology_permit_omit_accept_routes" above, but
+			// on non-Synology distro.
+			name:  "not_synology_dont_permit_omit_accept_routes",
+			flags: []string{"--hostname=foo"},
+			curPrefs: &ipn.Prefs{
+				ControlURL:       "https://login.tailscale.com",
+				CorpDNS:          true,
+				AllowSingleHosts: true,
+				RouteAll:         true,
+				NetfilterMode:    preftype.NetfilterOn,
+			},
+			goos:   "linux",
+			distro: "", // not Synology
+			want:   accidentalUpPrefix + " --hostname=foo --accept-routes",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -435,18 +487,22 @@ func TestCheckForAccidentalSettingReverts(t *testing.T) {
 			}
 			var upArgs upArgsT
 			flagSet := newUpFlagSet(goos, &upArgs)
-			flagSet.Parse(tt.flags)
+			flags := CleanUpArgs(tt.flags)
+			flagSet.Parse(flags)
 			newPrefs, err := prefsFromUpArgs(upArgs, t.Logf, new(ipnstate.Status), goos)
 			if err != nil {
 				t.Fatal(err)
 			}
-			applyImplicitPrefs(newPrefs, tt.curPrefs, tt.curUser)
-			var got string
-			if err := checkForAccidentalSettingReverts(newPrefs, tt.curPrefs, upCheckEnv{
+			upEnv := upCheckEnv{
 				goos:          goos,
 				flagSet:       flagSet,
 				curExitNodeIP: tt.curExitNodeIP,
-			}); err != nil {
+				distro:        tt.distro,
+				user:          tt.curUser,
+			}
+			applyImplicitPrefs(newPrefs, tt.curPrefs, upEnv)
+			var got string
+			if err := checkForAccidentalSettingReverts(newPrefs, tt.curPrefs, upEnv); err != nil {
 				got = err.Error()
 			}
 			if strings.TrimSpace(got) != tt.want {
@@ -494,6 +550,7 @@ func TestPrefsFromUpArgs(t *testing.T) {
 				WantRunning:      true,
 				CorpDNS:          true,
 				AllowSingleHosts: true,
+				RouteAll:         true,
 				NetfilterMode:    preftype.NetfilterOn,
 			},
 		},
@@ -505,9 +562,9 @@ func TestPrefsFromUpArgs(t *testing.T) {
 				WantRunning:      true,
 				AllowSingleHosts: true,
 				CorpDNS:          true,
-				AdvertiseRoutes: []netaddr.IPPrefix{
-					netaddr.MustParseIPPrefix("0.0.0.0/0"),
-					netaddr.MustParseIPPrefix("::/0"),
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("0.0.0.0/0"),
+					netip.MustParsePrefix("::/0"),
 				},
 				NetfilterMode: preftype.NetfilterOn,
 			},
@@ -531,7 +588,7 @@ func TestPrefsFromUpArgs(t *testing.T) {
 			args: upArgsT{
 				exitNodeIP: "foo",
 			},
-			wantErr: `invalid IP address "foo" for --exit-node: ParseIP("foo"): unable to parse IP`,
+			wantErr: `invalid value "foo" for --exit-node; must be IP or unique node name`,
 		},
 		{
 			name: "error_exit_node_allow_lan_without_exit_node",
@@ -574,9 +631,9 @@ func TestPrefsFromUpArgs(t *testing.T) {
 				exitNodeIP: "100.105.106.107",
 			},
 			st: &ipnstate.Status{
-				TailscaleIPs: []netaddr.IP{netaddr.MustParseIP("100.105.106.107")},
+				TailscaleIPs: []netip.Addr{netip.MustParseAddr("100.105.106.107")},
 			},
-			wantErr: `cannot use 100.105.106.107 as the exit node as it is a local IP address to this machine, did you mean --advertise-exit-node?`,
+			wantErr: `cannot use 100.105.106.107 as an exit node as it is a local IP address to this machine; did you mean --advertise-exit-node?`,
 		},
 		{
 			name: "warn_linux_netfilter_nodivert",
@@ -604,13 +661,43 @@ func TestPrefsFromUpArgs(t *testing.T) {
 				NoSNAT:        true,
 			},
 		},
+		{
+			name: "via_route_good",
+			goos: "linux",
+			args: upArgsT{
+				advertiseRoutes: "fd7a:115c:a1e0:b1a::bb:10.0.0.0/112",
+				netfilterMode:   "off",
+			},
+			want: &ipn.Prefs{
+				WantRunning: true,
+				NoSNAT:      true,
+				AdvertiseRoutes: []netip.Prefix{
+					netip.MustParsePrefix("fd7a:115c:a1e0:b1a::bb:10.0.0.0/112"),
+				},
+			},
+		},
+		{
+			name: "via_route_short_prefix",
+			goos: "linux",
+			args: upArgsT{
+				advertiseRoutes: "fd7a:115c:a1e0:b1a::/64",
+				netfilterMode:   "off",
+			},
+			wantErr: "fd7a:115c:a1e0:b1a::/64 4-in-6 prefix must be at least a /96",
+		},
+		{
+			name: "via_route_short_reserved_siteid",
+			goos: "linux",
+			args: upArgsT{
+				advertiseRoutes: "fd7a:115c:a1e0:b1a:1234:5678::/112",
+				netfilterMode:   "off",
+			},
+			wantErr: "route fd7a:115c:a1e0:b1a:1234:5678::/112 contains invalid site ID 12345678; must be 0xff or less",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			var warnBuf bytes.Buffer
-			warnf := func(format string, a ...interface{}) {
-				fmt.Fprintf(&warnBuf, format, a...)
-			}
+			var warnBuf tstest.MemLogger
 			goos := tt.goos
 			if goos == "" {
 				goos = "linux"
@@ -619,7 +706,7 @@ func TestPrefsFromUpArgs(t *testing.T) {
 			if st == nil {
 				st = new(ipnstate.Status)
 			}
-			got, err := prefsFromUpArgs(tt.args, warnf, st, goos)
+			got, err := prefsFromUpArgs(tt.args, warnBuf.Logf, st, goos)
 			gotErr := fmt.Sprint(err)
 			if tt.wantErr != "" {
 				if tt.wantErr != gotErr {
@@ -675,6 +762,9 @@ func TestPrefFlagMapping(t *testing.T) {
 		case "NotepadURLs":
 			// TODO(bradfitz): https://github.com/tailscale/tailscale/issues/1830
 			continue
+		case "Egg":
+			// Not applicable.
+			continue
 		}
 		t.Errorf("unexpected new ipn.Pref field %q is not handled by up.go (see addPrefFlagMapping and checkForAccidentalSettingReverts)", prefName)
 	}
@@ -699,6 +789,10 @@ func TestUpdatePrefs(t *testing.T) {
 		curPrefs *ipn.Prefs
 		env      upCheckEnv // empty goos means "linux"
 
+		// checkUpdatePrefsMutations, if non-nil, is run with the new prefs after
+		// updatePrefs might've mutated them (from applyImplicitPrefs).
+		checkUpdatePrefsMutations func(t *testing.T, newPrefs *ipn.Prefs)
+
 		wantSimpleUp   bool
 		wantJustEditMP *ipn.MaskedPrefs
 		wantErrSubtr   string
@@ -735,6 +829,33 @@ func TestUpdatePrefs(t *testing.T) {
 			wantSimpleUp:   true,
 			wantJustEditMP: &ipn.MaskedPrefs{WantRunningSet: true},
 		},
+		{
+			name:  "just_edit_reset",
+			flags: []string{"--reset"},
+			curPrefs: &ipn.Prefs{
+				ControlURL: ipn.DefaultControlURL,
+				Persist:    &persist.Persist{LoginName: "crawshaw.github"},
+			},
+			env: upCheckEnv{backendState: "Running"},
+			wantJustEditMP: &ipn.MaskedPrefs{
+				AdvertiseRoutesSet:        true,
+				AdvertiseTagsSet:          true,
+				AllowSingleHostsSet:       true,
+				ControlURLSet:             true,
+				CorpDNSSet:                true,
+				ExitNodeAllowLANAccessSet: true,
+				ExitNodeIDSet:             true,
+				ExitNodeIPSet:             true,
+				HostnameSet:               true,
+				NetfilterModeSet:          true,
+				NoSNATSet:                 true,
+				OperatorUserSet:           true,
+				RouteAllSet:               true,
+				RunSSHSet:                 true,
+				ShieldsUpSet:              true,
+				WantRunningSet:            true,
+			},
+		},
 		{
 			name:  "control_synonym",
 			flags: []string{},
@@ -761,6 +882,40 @@ func TestUpdatePrefs(t *testing.T) {
 			wantJustEditMP: &ipn.MaskedPrefs{WantRunningSet: true},
 			wantErrSubtr:   "can't change --login-server without --force-reauth",
 		},
+		{
+			name:  "change_tags",
+			flags: []string{"--advertise-tags=tag:foo"},
+			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"},
+		},
+		{
+			// Issue 3808: explicitly empty --operator= should clear value.
+			name:  "explicit_empty_operator",
+			flags: []string{"--operator="},
+			curPrefs: &ipn.Prefs{
+				ControlURL:       "https://login.tailscale.com",
+				CorpDNS:          true,
+				AllowSingleHosts: true,
+				NetfilterMode:    preftype.NetfilterOn,
+				OperatorUser:     "somebody",
+			},
+			env: upCheckEnv{user: "somebody", backendState: "Running"},
+			wantJustEditMP: &ipn.MaskedPrefs{
+				OperatorUserSet: true,
+				WantRunningSet:  true,
+			},
+			checkUpdatePrefsMutations: func(t *testing.T, prefs *ipn.Prefs) {
+				if prefs.OperatorUser != "" {
+					t.Errorf("operator sent to backend should be empty; got %q", prefs.OperatorUser)
+				}
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -768,7 +923,8 @@ func TestUpdatePrefs(t *testing.T) {
 				tt.env.goos = "linux"
 			}
 			tt.env.flagSet = newUpFlagSet(tt.env.goos, &tt.env.upArgs)
-			tt.env.flagSet.Parse(tt.flags)
+			flags := CleanUpArgs(tt.flags)
+			tt.env.flagSet.Parse(flags)
 
 			newPrefs, err := prefsFromUpArgs(tt.env.upArgs, t.Logf, new(ipnstate.Status), tt.env.goos)
 			if err != nil {
@@ -784,15 +940,51 @@ func TestUpdatePrefs(t *testing.T) {
 				}
 				t.Fatal(err)
 			}
+			if tt.checkUpdatePrefsMutations != nil {
+				tt.checkUpdatePrefsMutations(t, newPrefs)
+			}
 			if simpleUp != tt.wantSimpleUp {
 				t.Fatalf("simpleUp=%v, want %v", simpleUp, tt.wantSimpleUp)
 			}
+			var oldEditPrefs ipn.Prefs
 			if justEditMP != nil {
+				oldEditPrefs = justEditMP.Prefs
 				justEditMP.Prefs = ipn.Prefs{} // uninteresting
 			}
 			if !reflect.DeepEqual(justEditMP, tt.wantJustEditMP) {
-				t.Fatalf("justEditMP: %v", cmp.Diff(justEditMP, tt.wantJustEditMP))
+				t.Logf("justEditMP != wantJustEditMP; following diff omits the Prefs field, which was %+v", oldEditPrefs)
+				t.Fatalf("justEditMP: %v\n\n: ", cmp.Diff(justEditMP, tt.wantJustEditMP, cmpIP))
 			}
 		})
 	}
 }
+
+var cmpIP = cmp.Comparer(func(a, b netip.Addr) bool {
+	return a == b
+})
+
+func TestCleanUpArgs(t *testing.T) {
+	c := qt.New(t)
+	tests := []struct {
+		in   []string
+		want []string
+	}{
+		{in: []string{"something"}, want: []string{"something"}},
+		{in: []string{}, want: []string{}},
+		{in: []string{"--authkey=0"}, want: []string{"--auth-key=0"}},
+		{in: []string{"a", "--authkey=1", "b"}, want: []string{"a", "--auth-key=1", "b"}},
+		{in: []string{"a", "--auth-key=2", "b"}, want: []string{"a", "--auth-key=2", "b"}},
+		{in: []string{"a", "-authkey=3", "b"}, want: []string{"a", "--auth-key=3", "b"}},
+		{in: []string{"a", "-auth-key=4", "b"}, want: []string{"a", "-auth-key=4", "b"}},
+		{in: []string{"a", "--authkey", "5", "b"}, want: []string{"a", "--auth-key", "5", "b"}},
+		{in: []string{"a", "-authkey", "6", "b"}, want: []string{"a", "--auth-key", "6", "b"}},
+		{in: []string{"a", "authkey", "7", "b"}, want: []string{"a", "authkey", "7", "b"}},
+		{in: []string{"--authkeyexpiry", "8"}, want: []string{"--authkeyexpiry", "8"}},
+		{in: []string{"--auth-key-expiry", "9"}, want: []string{"--auth-key-expiry", "9"}},
+	}
+
+	for _, tt := range tests {
+		got := CleanUpArgs(tt.in)
+		c.Assert(got, qt.DeepEquals, tt.want)
+	}
+}

cmd/tailscale/cli/configure-host.go

@@ -0,0 +1,88 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"github.com/peterbourgon/ff/v3/ffcli"
+	"tailscale.com/hostinfo"
+	"tailscale.com/version/distro"
+)
+
+var configureHostCmd = &ffcli.Command{
+	Name:      "configure-host",
+	Exec:      runConfigureHost,
+	ShortHelp: "Configure Synology to enable more Tailscale features",
+	LongHelp: strings.TrimSpace(`
+The 'configure-host' command is intended to run at boot as root
+to create the /dev/net/tun device and give the tailscaled binary
+permission to use it.
+
+See: https://tailscale.com/kb/1152/synology-outbound/
+`),
+	FlagSet: (func() *flag.FlagSet {
+		fs := newFlagSet("configure-host")
+		return fs
+	})(),
+}
+
+var configureHostArgs struct{}
+
+func runConfigureHost(ctx context.Context, args []string) error {
+	if len(args) > 0 {
+		return errors.New("unknown arguments")
+	}
+	if runtime.GOOS != "linux" || distro.Get() != distro.Synology {
+		return errors.New("only implemented on Synology")
+	}
+	if uid := os.Getuid(); uid != 0 {
+		return fmt.Errorf("must be run as root, not %q (%v)", os.Getenv("USER"), uid)
+	}
+	osVer := hostinfo.GetOSVersion()
+	isDSM6 := strings.HasPrefix(osVer, "Synology 6")
+	isDSM7 := strings.HasPrefix(osVer, "Synology 7")
+	if !isDSM6 && !isDSM7 {
+		return fmt.Errorf("unsupported DSM version %q", osVer)
+	}
+	if _, err := os.Stat("/dev/net/tun"); os.IsNotExist(err) {
+		if err := os.MkdirAll("/dev/net", 0755); err != nil {
+			return fmt.Errorf("creating /dev/net: %v", err)
+		}
+		if out, err := exec.Command("/bin/mknod", "/dev/net/tun", "c", "10", "200").CombinedOutput(); err != nil {
+			return fmt.Errorf("creating /dev/net/tun: %v, %s", err, out)
+		}
+	}
+	if err := os.Chmod("/dev/net", 0755); err != nil {
+		return err
+	}
+	if err := os.Chmod("/dev/net/tun", 0666); err != nil {
+		return err
+	}
+	if isDSM6 {
+		printf("/dev/net/tun exists and has permissions 0666. Skipping setcap on DSM6.\n")
+		return nil
+	}
+
+	const daemonBin = "/var/packages/Tailscale/target/bin/tailscaled"
+	if _, err := os.Stat(daemonBin); err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("tailscaled binary not found at %s. Is the Tailscale *.spk package installed?", daemonBin)
+		}
+		return err
+	}
+	if out, err := exec.Command("/bin/setcap", "cap_net_admin,cap_net_raw+eip", daemonBin).CombinedOutput(); err != nil {
+		return fmt.Errorf("setcap: %v, %s", err, out)
+	}
+	printf("Done. To restart Tailscale to use the new permissions, run:\n\n  sudo synosystemctl restart pkgctl-Tailscale.service\n\n")
+	return nil
+}

cmd/tailscale/cli/debug.go

@@ -5,139 +5,503 @@
 package cli
 
 import (
+	"bufio"
+	"bytes"
 	"context"
+	"encoding/binary"
 	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
 	"io"
 	"log"
+	"net"
+	"net/http"
+	"net/netip"
 	"os"
 	"runtime"
+	"strconv"
 	"strings"
+	"time"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/client/tailscale"
+	"github.com/peterbourgon/ff/v3/ffcli"
+	"tailscale.com/control/controlhttp"
+	"tailscale.com/hostinfo"
 	"tailscale.com/ipn"
+	"tailscale.com/net/tsaddr"
 	"tailscale.com/paths"
 	"tailscale.com/safesocket"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/key"
 )
 
 var debugCmd = &ffcli.Command{
-	Name: "debug",
-	Exec: runDebug,
+	Name:     "debug",
+	Exec:     runDebug,
+	LongHelp: `"tailscale debug" contains misc debug facilities; it is not a stable interface.`,
 	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("debug", flag.ExitOnError)
-		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")
+		fs := newFlagSet("debug")
 		fs.StringVar(&debugArgs.file, "file", "", "get, delete:NAME, or NAME")
+		fs.StringVar(&debugArgs.cpuFile, "cpu-profile", "", "if non-empty, grab a CPU profile for --profile-sec seconds and write it to this file; - for stdout")
+		fs.StringVar(&debugArgs.memFile, "mem-profile", "", "if non-empty, grab a memory profile and write it to this file; - for stdout")
+		fs.IntVar(&debugArgs.cpuSec, "profile-seconds", 15, "number of seconds to run a CPU profile for, when --cpu-profile is non-empty")
 		return fs
 	})(),
+	Subcommands: []*ffcli.Command{
+		{
+			Name:      "derp-map",
+			Exec:      runDERPMap,
+			ShortHelp: "print DERP map",
+		},
+		{
+			Name:      "daemon-goroutines",
+			Exec:      runDaemonGoroutines,
+			ShortHelp: "print tailscaled's goroutines",
+		},
+		{
+			Name:      "metrics",
+			Exec:      runDaemonMetrics,
+			ShortHelp: "print tailscaled's metrics",
+			FlagSet: (func() *flag.FlagSet {
+				fs := newFlagSet("metrics")
+				fs.BoolVar(&metricsArgs.watch, "watch", false, "print JSON dump of delta values")
+				return fs
+			})(),
+		},
+		{
+			Name:      "env",
+			Exec:      runEnv,
+			ShortHelp: "print cmd/tailscale environment",
+		},
+		{
+			Name:      "stat",
+			Exec:      runStat,
+			ShortHelp: "stat a file",
+		},
+		{
+			Name:      "hostinfo",
+			Exec:      runHostinfo,
+			ShortHelp: "print hostinfo",
+		},
+		{
+			Name:      "local-creds",
+			Exec:      runLocalCreds,
+			ShortHelp: "print how to access Tailscale local API",
+		},
+		{
+			Name:      "restun",
+			Exec:      localAPIAction("restun"),
+			ShortHelp: "force a magicsock restun",
+		},
+		{
+			Name:      "rebind",
+			Exec:      localAPIAction("rebind"),
+			ShortHelp: "force a magicsock rebind",
+		},
+		{
+			Name:      "prefs",
+			Exec:      runPrefs,
+			ShortHelp: "print prefs",
+			FlagSet: (func() *flag.FlagSet {
+				fs := newFlagSet("prefs")
+				fs.BoolVar(&prefsArgs.pretty, "pretty", false, "If true, pretty-print output")
+				return fs
+			})(),
+		},
+		{
+			Name:      "watch-ipn",
+			Exec:      runWatchIPN,
+			ShortHelp: "subscribe to IPN message bus",
+			FlagSet: (func() *flag.FlagSet {
+				fs := newFlagSet("watch-ipn")
+				fs.BoolVar(&watchIPNArgs.netmap, "netmap", true, "include netmap in messages")
+				return fs
+			})(),
+		},
+		{
+			Name:      "via",
+			Exec:      runVia,
+			ShortHelp: "convert between site-specific IPv4 CIDRs and IPv6 'via' routes",
+		},
+		{
+			Name:      "ts2021",
+			Exec:      runTS2021,
+			ShortHelp: "debug ts2021 protocol connectivity",
+			FlagSet: (func() *flag.FlagSet {
+				fs := newFlagSet("ts2021")
+				fs.StringVar(&ts2021Args.host, "host", "controlplane.tailscale.com", "hostname of control plane")
+				fs.IntVar(&ts2021Args.version, "version", int(tailcfg.CurrentCapabilityVersion), "protocol version")
+				return fs
+			})(),
+		},
+	},
 }
 
 var debugArgs struct {
-	localCreds bool
-	goroutines bool
-	ipn        bool
-	netMap     bool
-	derpMap    bool
-	file       string
-	prefs      bool
-	pretty     bool
+	file    string
+	cpuSec  int
+	cpuFile string
+	memFile string
+}
+
+func writeProfile(dst string, v []byte) error {
+	if dst == "-" {
+		_, err := Stdout.Write(v)
+		return err
+	}
+	return os.WriteFile(dst, v, 0600)
+}
+
+func outName(dst string) string {
+	if dst == "-" {
+		return "stdout"
+	}
+	if runtime.GOOS == "darwin" {
+		return fmt.Sprintf("%s (warning: sandboxed macOS binaries write to Library/Containers; use - to write to stdout and redirect to file instead)", dst)
+	}
+	return dst
 }
 
 func runDebug(ctx context.Context, args []string) error {
 	if len(args) > 0 {
 		return errors.New("unknown arguments")
 	}
-	if debugArgs.localCreds {
-		port, token, err := safesocket.LocalTCPPortAndToken()
-		if err == nil {
-			fmt.Printf("curl -u:%s http://localhost:%d/localapi/v0/status\n", token, port)
-			return nil
-		}
-		if runtime.GOOS == "windows" {
-			fmt.Printf("curl http://localhost:41112/localapi/v0/status\n")
-			return nil
-		}
-		fmt.Printf("curl --unix-socket %s http://foo/localapi/v0/status\n", paths.DefaultTailscaledSocket())
-		return nil
-	}
-	if debugArgs.prefs {
-		prefs, err := tailscale.GetPrefs(ctx)
-		if err != nil {
+	var usedFlag bool
+	if out := debugArgs.cpuFile; out != "" {
+		usedFlag = true // TODO(bradfitz): add "profile" subcommand
+		log.Printf("Capturing CPU profile for %v seconds ...", debugArgs.cpuSec)
+		if v, err := localClient.Profile(ctx, "profile", debugArgs.cpuSec); err != nil {
 			return err
-		}
-		if debugArgs.pretty {
-			fmt.Println(prefs.Pretty())
 		} else {
-			j, _ := json.MarshalIndent(prefs, "", "\t")
-			fmt.Println(string(j))
-		}
-		return nil
-	}
-	if debugArgs.goroutines {
-		goroutines, err := tailscale.Goroutines(ctx)
-		if err != nil {
-			return err
-		}
-		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()
-
-		bc.SetNotifyCallback(func(n ipn.Notify) {
-			if !debugArgs.netMap {
-				n.NetMap = nil
+			if err := writeProfile(out, v); err != nil {
+				return err
 			}
-			j, _ := json.MarshalIndent(n, "", "\t")
-			fmt.Printf("%s\n", j)
-		})
-		bc.RequestEngineStatus()
-		pump(ctx, bc, c)
-		return errors.New("exit")
+			log.Printf("CPU profile written to %s", outName(out))
+		}
+	}
+	if out := debugArgs.memFile; out != "" {
+		usedFlag = true // TODO(bradfitz): add "profile" subcommand
+		log.Printf("Capturing memory profile ...")
+		if v, err := localClient.Profile(ctx, "heap", 0); err != nil {
+			return err
+		} else {
+			if err := writeProfile(out, v); err != nil {
+				return err
+			}
+			log.Printf("Memory profile written to %s", outName(out))
+		}
 	}
 	if debugArgs.file != "" {
+		usedFlag = true // TODO(bradfitz): add "file" subcommand
 		if debugArgs.file == "get" {
-			wfs, err := tailscale.WaitingFiles(ctx)
+			wfs, err := localClient.WaitingFiles(ctx)
 			if err != nil {
-				log.Fatal(err)
+				fatalf("%v\n", err)
 			}
-			e := json.NewEncoder(os.Stdout)
+			e := json.NewEncoder(Stdout)
 			e.SetIndent("", "\t")
 			e.Encode(wfs)
 			return nil
 		}
 		delete := strings.HasPrefix(debugArgs.file, "delete:")
 		if delete {
-			return tailscale.DeleteWaitingFile(ctx, strings.TrimPrefix(debugArgs.file, "delete:"))
+			return localClient.DeleteWaitingFile(ctx, strings.TrimPrefix(debugArgs.file, "delete:"))
 		}
-		rc, size, err := tailscale.GetWaitingFile(ctx, debugArgs.file)
+		rc, size, err := localClient.GetWaitingFile(ctx, debugArgs.file)
 		if err != nil {
 			return err
 		}
 		log.Printf("Size: %v\n", size)
-		io.Copy(os.Stdout, rc)
+		io.Copy(Stdout, rc)
 		return nil
 	}
+	if usedFlag {
+		// TODO(bradfitz): delete this path when all debug flags are migrated
+		// to subcommands.
+		return nil
+	}
+	return errors.New("see 'tailscale debug --help")
+}
+
+func runLocalCreds(ctx context.Context, args []string) error {
+	port, token, err := safesocket.LocalTCPPortAndToken()
+	if err == nil {
+		printf("curl -u:%s http://localhost:%d/localapi/v0/status\n", token, port)
+		return nil
+	}
+	if runtime.GOOS == "windows" {
+		printf("curl http://localhost:%v/localapi/v0/status\n", safesocket.WindowsLocalPort)
+		return nil
+	}
+	printf("curl --unix-socket %s http://foo/localapi/v0/status\n", paths.DefaultTailscaledSocket())
+	return nil
+}
+
+var prefsArgs struct {
+	pretty bool
+}
+
+func runPrefs(ctx context.Context, args []string) error {
+	prefs, err := localClient.GetPrefs(ctx)
+	if err != nil {
+		return err
+	}
+	if prefsArgs.pretty {
+		outln(prefs.Pretty())
+	} else {
+		j, _ := json.MarshalIndent(prefs, "", "\t")
+		outln(string(j))
+	}
+	return nil
+}
+
+var watchIPNArgs struct {
+	netmap bool
+}
+
+func runWatchIPN(ctx context.Context, args []string) error {
+	c, bc, ctx, cancel := connect(ctx)
+	defer cancel()
+
+	bc.SetNotifyCallback(func(n ipn.Notify) {
+		if !watchIPNArgs.netmap {
+			n.NetMap = nil
+		}
+		j, _ := json.MarshalIndent(n, "", "\t")
+		printf("%s\n", j)
+	})
+	bc.RequestEngineStatus()
+	pump(ctx, bc, c)
+	return errors.New("exit")
+}
+
+func runDERPMap(ctx context.Context, args []string) error {
+	dm, err := localClient.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(Stdout)
+	enc.SetIndent("", "\t")
+	enc.Encode(dm)
+	return nil
+}
+
+func localAPIAction(action string) func(context.Context, []string) error {
+	return func(ctx context.Context, args []string) error {
+		if len(args) > 0 {
+			return errors.New("unexpected arguments")
+		}
+		return localClient.DebugAction(ctx, action)
+	}
+}
+
+func runEnv(ctx context.Context, args []string) error {
+	for _, e := range os.Environ() {
+		outln(e)
+	}
+	return nil
+}
+
+func runStat(ctx context.Context, args []string) error {
+	for _, a := range args {
+		fi, err := os.Lstat(a)
+		if err != nil {
+			printf("%s: %v\n", a, err)
+			continue
+		}
+		printf("%s: %v, %v\n", a, fi.Mode(), fi.Size())
+		if fi.IsDir() {
+			ents, _ := os.ReadDir(a)
+			for i, ent := range ents {
+				if i == 25 {
+					printf("  ...\n")
+					break
+				}
+				printf("  - %s\n", ent.Name())
+			}
+		}
+	}
+	return nil
+}
+
+func runHostinfo(ctx context.Context, args []string) error {
+	hi := hostinfo.New()
+	j, _ := json.MarshalIndent(hi, "", "  ")
+	os.Stdout.Write(j)
+	return nil
+}
+
+func runDaemonGoroutines(ctx context.Context, args []string) error {
+	goroutines, err := localClient.Goroutines(ctx)
+	if err != nil {
+		return err
+	}
+	Stdout.Write(goroutines)
+	return nil
+}
+
+var metricsArgs struct {
+	watch bool
+}
+
+func runDaemonMetrics(ctx context.Context, args []string) error {
+	last := map[string]int64{}
+	for {
+		out, err := localClient.DaemonMetrics(ctx)
+		if err != nil {
+			return err
+		}
+		if !metricsArgs.watch {
+			Stdout.Write(out)
+			return nil
+		}
+		bs := bufio.NewScanner(bytes.NewReader(out))
+		type change struct {
+			name     string
+			from, to int64
+		}
+		var changes []change
+		var maxNameLen int
+		for bs.Scan() {
+			line := bytes.TrimSpace(bs.Bytes())
+			if len(line) == 0 || line[0] == '#' {
+				continue
+			}
+			f := strings.Fields(string(line))
+			if len(f) != 2 {
+				continue
+			}
+			name := f[0]
+			n, _ := strconv.ParseInt(f[1], 10, 64)
+			prev, ok := last[name]
+			if ok && prev == n {
+				continue
+			}
+			last[name] = n
+			if !ok {
+				continue
+			}
+			changes = append(changes, change{name, prev, n})
+			if len(name) > maxNameLen {
+				maxNameLen = len(name)
+			}
+		}
+		if len(changes) > 0 {
+			format := fmt.Sprintf("%%-%ds %%+5d => %%v\n", maxNameLen)
+			for _, c := range changes {
+				fmt.Fprintf(Stdout, format, c.name, c.to-c.from, c.to)
+			}
+			io.WriteString(Stdout, "\n")
+		}
+		time.Sleep(time.Second)
+	}
+}
+
+func runVia(ctx context.Context, args []string) error {
+	switch len(args) {
+	default:
+		return errors.New("expect either <site-id> <v4-cidr> or <v6-route>")
+	case 1:
+		ipp, err := netip.ParsePrefix(args[0])
+		if err != nil {
+			return err
+		}
+		if !ipp.Addr().Is6() {
+			return errors.New("with one argument, expect an IPv6 CIDR")
+		}
+		if !tsaddr.TailscaleViaRange().Contains(ipp.Addr()) {
+			return errors.New("not a via route")
+		}
+		if ipp.Bits() < 96 {
+			return errors.New("short length, want /96 or more")
+		}
+		v4 := tsaddr.UnmapVia(ipp.Addr())
+		a := ipp.Addr().As16()
+		siteID := binary.BigEndian.Uint32(a[8:12])
+		printf("site %v (0x%x), %v\n", siteID, siteID, netip.PrefixFrom(v4, ipp.Bits()-96))
+	case 2:
+		siteID, err := strconv.ParseUint(args[0], 0, 32)
+		if err != nil {
+			return fmt.Errorf("invalid site-id %q; must be decimal or hex with 0x prefix", args[0])
+		}
+		if siteID > 0xff {
+			return fmt.Errorf("site-id values over 255 are currently reserved")
+		}
+		ipp, err := netip.ParsePrefix(args[1])
+		if err != nil {
+			return err
+		}
+		via, err := tsaddr.MapVia(uint32(siteID), ipp)
+		if err != nil {
+			return err
+		}
+		outln(via)
+	}
+	return nil
+}
+
+var ts2021Args struct {
+	host    string // "controlplane.tailscale.com"
+	version int    // 27 or whatever
+}
+
+func runTS2021(ctx context.Context, args []string) error {
+	log.SetOutput(os.Stdout)
+	log.SetFlags(log.Ltime | log.Lmicroseconds)
+
+	machinePrivate := key.NewMachine()
+	var dialer net.Dialer
+
+	var keys struct {
+		PublicKey key.MachinePublic
+	}
+	keysURL := "https://" + ts2021Args.host + "/key?v=" + strconv.Itoa(ts2021Args.version)
+	log.Printf("Fetching keys from %s ...", keysURL)
+	req, err := http.NewRequestWithContext(ctx, "GET", keysURL, nil)
+	if err != nil {
+		return err
+	}
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		log.Printf("Do: %v", err)
+		return err
+	}
+	if res.StatusCode != 200 {
+		log.Printf("Status: %v", res.Status)
+		return errors.New(res.Status)
+	}
+	if err := json.NewDecoder(res.Body).Decode(&keys); err != nil {
+		log.Printf("JSON: %v", err)
+		return fmt.Errorf("decoding /keys JSON: %w", err)
+	}
+	res.Body.Close()
+
+	dialFunc := func(ctx context.Context, network, address string) (net.Conn, error) {
+		log.Printf("Dial(%q, %q) ...", network, address)
+		c, err := dialer.DialContext(ctx, network, address)
+		if err != nil {
+			log.Printf("Dial(%q, %q) = %v", network, address, err)
+		} else {
+			log.Printf("Dial(%q, %q) = %v / %v", network, address, c.LocalAddr(), c.RemoteAddr())
+		}
+		return c, err
+	}
+
+	conn, err := controlhttp.Dial(ctx, ts2021Args.host, "80", "443", machinePrivate, keys.PublicKey, uint16(ts2021Args.version), dialFunc)
+	log.Printf("controlhttp.Dial = %p, %v", conn, err)
+	if err != nil {
+		return err
+	}
+	log.Printf("did noise handshake")
+
+	gotPeer := conn.Peer()
+	if gotPeer != keys.PublicKey {
+		log.Printf("peer = %v, want %v", gotPeer, keys.PublicKey)
+		return errors.New("key mismatch")
+	}
+
+	log.Printf("final underlying conn: %v / %v", conn.LocalAddr(), conn.RemoteAddr())
 	return nil
 }

cmd/tailscale/cli/diag.go

@@ -25,23 +25,23 @@ func fixTailscaledConnectError(origErr error) error {
 	if err != nil {
 		return fmt.Errorf("failed to connect to local Tailscaled process and failed to enumerate processes while looking for it")
 	}
-	found := false
+	var foundProc ps.Process
 	for _, proc := range procs {
 		base := filepath.Base(proc.Executable())
 		if base == "tailscaled" {
-			found = true
+			foundProc = proc
 			break
 		}
 		if runtime.GOOS == "darwin" && base == "IPNExtension" {
-			found = true
+			foundProc = proc
 			break
 		}
 		if runtime.GOOS == "windows" && strings.EqualFold(base, "tailscaled.exe") {
-			found = true
+			foundProc = proc
 			break
 		}
 	}
-	if !found {
+	if foundProc == nil {
 		switch runtime.GOOS {
 		case "windows":
 			return fmt.Errorf("failed to connect to local tailscaled process; is the Tailscale service running?")
@@ -52,5 +52,5 @@ func fixTailscaledConnectError(origErr error) error {
 		}
 		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)
+	return fmt.Errorf("failed to connect to local tailscaled (which appears to be running as %v, pid %v). Got error: %w", foundProc.Executable(), foundProc.Pid(), origErr)
 }

cmd/tailscale/cli/down.go

@@ -6,12 +6,10 @@ package cli
 
 import (
 	"context"
+	"flag"
 	"fmt"
-	"log"
-	"os"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/client/tailscale"
+	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/ipn"
 )
 
@@ -20,23 +18,36 @@ var downCmd = &ffcli.Command{
 	ShortUsage: "down",
 	ShortHelp:  "Disconnect from Tailscale",
 
-	Exec: runDown,
+	Exec:    runDown,
+	FlagSet: newDownFlagSet(),
+}
+
+func newDownFlagSet() *flag.FlagSet {
+	downf := newFlagSet("down")
+	registerAcceptRiskFlag(downf)
+	return downf
 }
 
 func runDown(ctx context.Context, args []string) error {
 	if len(args) > 0 {
-		log.Fatalf("too many non-flag arguments: %q", args)
+		return fmt.Errorf("too many non-flag arguments: %q", args)
 	}
 
-	st, err := tailscale.Status(ctx)
+	if isSSHOverTailscale() {
+		if err := presentRiskToUser(riskLoseSSH, `You are connected over Tailscale; this action will disable Tailscale and result in your session disconnecting.`); err != nil {
+			return err
+		}
+	}
+
+	st, err := localClient.Status(ctx)
 	if err != nil {
 		return fmt.Errorf("error fetching current status: %w", err)
 	}
 	if st.BackendState == "Stopped" {
-		fmt.Fprintf(os.Stderr, "Tailscale was already stopped.\n")
+		fmt.Fprintf(Stderr, "Tailscale was already stopped.\n")
 		return nil
 	}
-	_, err = tailscale.EditPrefs(ctx, &ipn.MaskedPrefs{
+	_, err = localClient.EditPrefs(ctx, &ipn.MaskedPrefs{
 		Prefs: ipn.Prefs{
 			WantRunning: false,
 		},

cmd/tailscale/cli/file.go

@@ -11,25 +11,24 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"mime"
 	"net/http"
-	"net/url"
+	"net/netip"
 	"os"
+	"path"
 	"path/filepath"
-	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
+	"github.com/peterbourgon/ff/v3/ffcli"
 	"golang.org/x/time/rate"
-	"inet.af/netaddr"
-	"tailscale.com/client/tailscale"
 	"tailscale.com/client/tailscale/apitype"
+	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/net/tsaddr"
+	"tailscale.com/tailcfg"
 	"tailscale.com/version"
 )
 
@@ -55,7 +54,7 @@ var fileCpCmd = &ffcli.Command{
 	ShortHelp:  "Copy file(s) to a host",
 	Exec:       runCp,
 	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("cp", flag.ExitOnError)
+		fs := newFlagSet("cp")
 		fs.StringVar(&cpArgs.name, "name", "", "alternate filename to use, especially useful when <file> is \"-\" (stdin)")
 		fs.BoolVar(&cpArgs.verbose, "verbose", false, "verbose output")
 		fs.BoolVar(&cpArgs.targets, "targets", false, "list possible file cp targets")
@@ -86,22 +85,22 @@ func runCp(ctx context.Context, args []string) error {
 		hadBrackets = true
 		target = strings.TrimSuffix(strings.TrimPrefix(target, "["), "]")
 	}
-	if ip, err := netaddr.ParseIP(target); err == nil && ip.Is6() && !hadBrackets {
+	if ip, err := netip.ParseAddr(target); err == nil && ip.Is6() && !hadBrackets {
 		return fmt.Errorf("an IPv6 literal must be written as [%s]", ip)
 	} else if hadBrackets && (err != nil || !ip.Is6()) {
 		return errors.New("unexpected brackets around target")
 	}
-	ip, err := tailscaleIPFromArg(ctx, target)
+	ip, _, err := tailscaleIPFromArg(ctx, target)
 	if err != nil {
 		return err
 	}
 
-	peerAPIBase, isOffline, err := discoverPeerAPIBase(ctx, ip)
+	stableID, isOffline, err := getTargetStableID(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)
+		fmt.Fprintf(Stderr, "# warning: %s is offline\n", target)
 	}
 
 	if len(files) > 1 {
@@ -149,53 +148,42 @@ func runCp(ctx context.Context, args []string) error {
 				name = filepath.Base(fileArg)
 			}
 
-			if slow, _ := strconv.ParseBool(os.Getenv("TS_DEBUG_SLOW_PUSH")); slow {
+			if envknob.Bool("TS_DEBUG_SLOW_PUSH") {
 				fileContents = &slowReader{r: fileContents}
 			}
 		}
 
-		dstURL := peerAPIBase + "/v0/put/" + url.PathEscape(name)
-		req, err := http.NewRequestWithContext(ctx, "PUT", dstURL, fileContents)
-		if err != nil {
-			return err
-		}
-		req.ContentLength = contentLength
 		if cpArgs.verbose {
-			log.Printf("sending to %v ...", dstURL)
+			log.Printf("sending %q to %v/%v/%v ...", name, target, ip, stableID)
 		}
-		res, err := http.DefaultClient.Do(req)
+		err := localClient.PushFile(ctx, stableID, contentLength, name, fileContents)
 		if err != nil {
 			return err
 		}
-		if res.StatusCode == 200 {
-			io.Copy(ioutil.Discard, res.Body)
-			res.Body.Close()
-			continue
+		if cpArgs.verbose {
+			log.Printf("sent %q", name)
 		}
-		io.Copy(os.Stdout, res.Body)
-		res.Body.Close()
-		return errors.New(res.Status)
 	}
 	return nil
 }
 
-func discoverPeerAPIBase(ctx context.Context, ipStr string) (base string, isOffline bool, err error) {
-	ip, err := netaddr.ParseIP(ipStr)
+func getTargetStableID(ctx context.Context, ipStr string) (id tailcfg.StableNodeID, isOffline bool, err error) {
+	ip, err := netip.ParseAddr(ipStr)
 	if err != nil {
 		return "", false, err
 	}
-	fts, err := tailscale.FileTargets(ctx)
+	fts, err := localClient.FileTargets(ctx)
 	if err != nil {
 		return "", false, err
 	}
 	for _, ft := range fts {
 		n := ft.Node
 		for _, a := range n.Addresses {
-			if a.IP() != ip {
+			if a.Addr() != ip {
 				continue
 			}
 			isOffline = n.Online != nil && !*n.Online
-			return ft.PeerAPIURL, isOffline, nil
+			return n.StableID, isOffline, nil
 		}
 	}
 	return "", false, fileTargetErrorDetail(ctx, ip)
@@ -203,9 +191,9 @@ func discoverPeerAPIBase(ctx context.Context, ipStr string) (base string, isOffl
 
 // fileTargetErrorDetail returns a non-nil error saying why ip is an
 // invalid file sharing target.
-func fileTargetErrorDetail(ctx context.Context, ip netaddr.IP) error {
+func fileTargetErrorDetail(ctx context.Context, ip netip.Addr) error {
 	found := false
-	if st, err := tailscale.Status(ctx); err == nil && st.Self != nil {
+	if st, err := localClient.Status(ctx); err == nil && st.Self != nil {
 		for _, peer := range st.Peer {
 			for _, pip := range peer.TailscaleIPs {
 				if pip == ip {
@@ -272,7 +260,7 @@ func runCpTargets(ctx context.Context, args []string) error {
 	if len(args) > 0 {
 		return errors.New("invalid arguments with --targets")
 	}
-	fts, err := tailscale.FileTargets(ctx)
+	fts, err := localClient.FileTargets(ctx)
 	if err != nil {
 		return err
 	}
@@ -293,27 +281,176 @@ func runCpTargets(ctx context.Context, args []string) error {
 		if detail != "" {
 			detail = "\t" + detail
 		}
-		fmt.Printf("%s\t%s%s\n", n.Addresses[0].IP(), n.ComputedName, detail)
+		printf("%s\t%s%s\n", n.Addresses[0].Addr(), n.ComputedName, detail)
+	}
+	return nil
+}
+
+// onConflict is a flag.Value for the --conflict flag's three string options.
+type onConflict string
+
+const (
+	skipOnExist         onConflict = "skip"
+	overwriteExisting   onConflict = "overwrite" //  Overwrite any existing file at the target location
+	createNumberedFiles onConflict = "rename"    //  Create an alternately named file in the style of Chrome Downloads
+)
+
+func (v *onConflict) String() string { return string(*v) }
+
+func (v *onConflict) Set(s string) error {
+	if s == "" {
+		*v = skipOnExist
+		return nil
+	}
+	*v = onConflict(strings.ToLower(s))
+	if *v != skipOnExist && *v != overwriteExisting && *v != createNumberedFiles {
+		return fmt.Errorf("%q is not one of (skip|overwrite|rename)", s)
 	}
 	return nil
 }
 
 var fileGetCmd = &ffcli.Command{
 	Name:       "get",
-	ShortUsage: "file get [--wait] [--verbose] <target-directory>",
+	ShortUsage: "file get [--wait] [--verbose] [--conflict=(skip|overwrite|rename)] <target-directory>",
 	ShortHelp:  "Move files out of the Tailscale file inbox",
 	Exec:       runFileGet,
 	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("get", flag.ExitOnError)
+		fs := newFlagSet("get")
 		fs.BoolVar(&getArgs.wait, "wait", false, "wait for a file to arrive if inbox is empty")
+		fs.BoolVar(&getArgs.loop, "loop", false, "run get in a loop, receiving files as they come in")
 		fs.BoolVar(&getArgs.verbose, "verbose", false, "verbose output")
+		fs.Var(&getArgs.conflict, "conflict", `behavior when a conflicting (same-named) file already exists in the target directory.
+	skip:       skip conflicting files: leave them in the taildrop inbox and print an error. get any non-conflicting files
+	overwrite:  overwrite existing file
+	rename:     write to a new number-suffixed filename`)
 		return fs
 	})(),
 }
 
-var getArgs struct {
-	wait    bool
-	verbose bool
+var getArgs = struct {
+	wait     bool
+	loop     bool
+	verbose  bool
+	conflict onConflict
+}{conflict: skipOnExist}
+
+func numberedFileName(dir, name string, i int) string {
+	ext := path.Ext(name)
+	return filepath.Join(dir, fmt.Sprintf("%s (%d)%s",
+		strings.TrimSuffix(name, ext),
+		i, ext))
+}
+
+func openFileOrSubstitute(dir, base string, action onConflict) (*os.File, error) {
+	targetFile := filepath.Join(dir, base)
+	f, err := os.OpenFile(targetFile, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644)
+	if err == nil {
+		return f, nil
+	}
+	// Something went wrong trying to open targetFile as a new file for writing.
+	switch action {
+	default:
+		// This should not happen.
+		return nil, fmt.Errorf("file issue. how to resolve this conflict? no one knows.")
+	case skipOnExist:
+		if _, statErr := os.Stat(targetFile); statErr == nil {
+			// we can stat a file at that path: so it already exists.
+			return nil, fmt.Errorf("refusing to overwrite file: %w", err)
+		}
+		return nil, fmt.Errorf("failed to write; %w", err)
+	case overwriteExisting:
+		// remove the target file and create it anew so we don't fall for an
+		// attacker who symlinks a known target name to a file he wants changed.
+		if err = os.Remove(targetFile); err != nil {
+			return nil, fmt.Errorf("unable to remove target file: %w", err)
+		}
+		if f, err = os.OpenFile(targetFile, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644); err != nil {
+			return nil, fmt.Errorf("unable to overwrite: %w", err)
+		}
+		return f, nil
+	case createNumberedFiles:
+		// It's possible the target directory or filesystem isn't writable by us,
+		// not just that the target file(s) already exists.  For now, give up after
+		// a limited number of attempts.  In future, maybe distinguish this case
+		// and follow in the style of https://tinyurl.com/chromium100
+		maxAttempts := 100
+		for i := 1; i < maxAttempts; i++ {
+			if f, err = os.OpenFile(numberedFileName(dir, base, i), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644); err == nil {
+				return f, nil
+			}
+		}
+		return nil, fmt.Errorf("unable to find a name for writing %v, final attempt: %w", targetFile, err)
+	}
+}
+
+func receiveFile(ctx context.Context, wf apitype.WaitingFile, dir string) (targetFile string, size int64, err error) {
+	rc, size, err := localClient.GetWaitingFile(ctx, wf.Name)
+	if err != nil {
+		return "", 0, fmt.Errorf("opening inbox file %q: %w", wf.Name, err)
+	}
+	defer rc.Close()
+	f, err := openFileOrSubstitute(dir, wf.Name, getArgs.conflict)
+	if err != nil {
+		return "", 0, err
+	}
+	_, err = io.Copy(f, rc)
+	if err != nil {
+		f.Close()
+		return "", 0, fmt.Errorf("failed to write %v: %v", f.Name(), err)
+	}
+	return f.Name(), size, f.Close()
+}
+
+func runFileGetOneBatch(ctx context.Context, dir string) []error {
+	var wfs []apitype.WaitingFile
+	var err error
+	var errs []error
+	for len(errs) == 0 {
+		wfs, err = localClient.WaitingFiles(ctx)
+		if err != nil {
+			errs = append(errs, fmt.Errorf("getting WaitingFiles: %w", err))
+			break
+		}
+		if len(wfs) != 0 || !(getArgs.wait || getArgs.loop) {
+			break
+		}
+		if getArgs.verbose {
+			printf("waiting for file...")
+		}
+		if err := waitForFile(ctx); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	deleted := 0
+	for i, wf := range wfs {
+		if len(errs) > 100 {
+			// Likely, everything is broken.
+			// Don't try to receive any more files in this batch.
+			errs = append(errs, fmt.Errorf("too many errors in runFileGetOneBatch(). %d files unexamined", len(wfs)-i))
+			break
+		}
+		writtenFile, size, err := receiveFile(ctx, wf, dir)
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		if getArgs.verbose {
+			printf("wrote %v as %v (%d bytes)\n", wf.Name, writtenFile, size)
+		}
+		if err = localClient.DeleteWaitingFile(ctx, wf.Name); err != nil {
+			errs = append(errs, fmt.Errorf("deleting %q from inbox: %v", wf.Name, err))
+			continue
+		}
+		deleted++
+	}
+	if deleted == 0 && len(wfs) > 0 {
+		// persistently stuck files are basically an error
+		errs = append(errs, fmt.Errorf("moved %d/%d files", deleted, len(wfs)))
+	} else if getArgs.verbose {
+		printf("moved %d/%d files\n", deleted, len(wfs))
+	}
+	return errs
 }
 
 func runFileGet(ctx context.Context, args []string) error {
@@ -330,75 +467,51 @@ func runFileGet(ctx context.Context, args []string) error {
 	if fi, err := os.Stat(dir); err != nil || !fi.IsDir() {
 		return fmt.Errorf("%q is not a directory", dir)
 	}
-
-	var wfs []apitype.WaitingFile
-	var err error
-	for {
-		wfs, err = tailscale.WaitingFiles(ctx)
-		if err != nil {
-			return fmt.Errorf("getting WaitingFiles: %v", err)
-		}
-		if len(wfs) != 0 || !getArgs.wait {
-			break
-		}
-		if getArgs.verbose {
-			log.Printf("waiting for file...")
-		}
-		if err := waitForFile(ctx); err != nil {
-			return err
-		}
-	}
-
-	deleted := 0
-	for _, wf := range wfs {
-		rc, size, err := tailscale.GetWaitingFile(ctx, wf.Name)
-		if err != nil {
-			return fmt.Errorf("opening inbox file %q: %v", wf.Name, err)
-		}
-		targetFile := filepath.Join(dir, wf.Name)
-		of, err := os.OpenFile(targetFile, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644)
-		if err != nil {
-			if _, err := os.Stat(targetFile); err == nil {
-				return fmt.Errorf("refusing to overwrite %v", targetFile)
+	if getArgs.loop {
+		for {
+			errs := runFileGetOneBatch(ctx, dir)
+			for _, err := range errs {
+				outln(err)
+			}
+			if len(errs) > 0 {
+				// It's possible whatever caused the error(s) (e.g. conflicting target file,
+				// full disk, unwritable target directory) will re-occur if we try again so
+				// let's back off and not busy loop on error.
+				//
+				// If we've been invoked as:
+				//    tailscale file get --conflict=skip ~/Downloads
+				// then any file coming in named the same as one in ~/Downloads will always
+				// appear as an "error" until the user clears it, but other incoming files
+				// should be receivable when they arrive, so let's not wait too long to
+				// check again.
+				time.Sleep(5 * time.Second)
 			}
-			return err
 		}
-		_, err = io.Copy(of, rc)
-		rc.Close()
-		if err != nil {
-			return fmt.Errorf("failed to write %v: %v", targetFile, err)
-		}
-		if err := of.Close(); err != nil {
-			return err
-		}
-		if getArgs.verbose {
-			log.Printf("wrote %v (%d bytes)", wf.Name, size)
-		}
-		if err := tailscale.DeleteWaitingFile(ctx, wf.Name); err != nil {
-			return fmt.Errorf("deleting %q from inbox: %v", wf.Name, err)
-		}
-		deleted++
 	}
-	if getArgs.verbose {
-		log.Printf("moved %d files", deleted)
+	errs := runFileGetOneBatch(ctx, dir)
+	if len(errs) == 0 {
+		return nil
 	}
-	return nil
+	for _, err := range errs[:len(errs)-1] {
+		outln(err)
+	}
+	return errs[len(errs)-1]
 }
 
 func wipeInbox(ctx context.Context) error {
 	if getArgs.wait {
 		return errors.New("can't use --wait with /dev/null target")
 	}
-	wfs, err := tailscale.WaitingFiles(ctx)
+	wfs, err := localClient.WaitingFiles(ctx)
 	if err != nil {
-		return fmt.Errorf("getting WaitingFiles: %v", err)
+		return fmt.Errorf("getting WaitingFiles: %w", err)
 	}
 	deleted := 0
 	for _, wf := range wfs {
 		if getArgs.verbose {
 			log.Printf("deleting %v ...", wf.Name)
 		}
-		if err := tailscale.DeleteWaitingFile(ctx, wf.Name); err != nil {
+		if err := localClient.DeleteWaitingFile(ctx, wf.Name); err != nil {
 			return fmt.Errorf("deleting %q: %v", wf.Name, err)
 		}
 		deleted++
@@ -413,9 +526,10 @@ func waitForFile(ctx context.Context) error {
 	c, bc, pumpCtx, cancel := connect(ctx)
 	defer cancel()
 	fileWaiting := make(chan bool, 1)
+	notifyError := make(chan error, 1)
 	bc.SetNotifyCallback(func(n ipn.Notify) {
 		if n.ErrMessage != nil {
-			log.Fatal(*n.ErrMessage)
+			notifyError <- fmt.Errorf("Notify.ErrMessage: %v", *n.ErrMessage)
 		}
 		if n.FilesWaiting != nil {
 			select {
@@ -432,5 +546,7 @@ func waitForFile(ctx context.Context) error {
 		return pumpCtx.Err()
 	case <-ctx.Done():
 		return ctx.Err()
+	case err := <-notifyError:
+		return err
 	}
 }

cmd/tailscale/cli/id-token.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"context"
+	"errors"
+
+	"github.com/peterbourgon/ff/v3/ffcli"
+)
+
+var idTokenCmd = &ffcli.Command{
+	Name:       "id-token",
+	ShortUsage: "id-token <aud>",
+	ShortHelp:  "fetch an OIDC id-token for the Tailscale machine",
+	Exec:       runIDToken,
+}
+
+func runIDToken(ctx context.Context, args []string) error {
+	if len(args) != 1 {
+		return errors.New("usage: id-token <aud>")
+	}
+
+	tr, err := localClient.IDToken(ctx, args[0])
+	if err != nil {
+		return err
+	}
+
+	outln(tr.IDToken)
+	return nil
+}

cmd/tailscale/cli/ip.go

@@ -9,21 +9,21 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"net/netip"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"inet.af/netaddr"
-	"tailscale.com/client/tailscale"
+	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/ipn/ipnstate"
 )
 
 var ipCmd = &ffcli.Command{
 	Name:       "ip",
-	ShortUsage: "ip [-4] [-6] [peername]",
-	ShortHelp:  "Show current Tailscale IP address(es)",
-	LongHelp:   "Shows the Tailscale IP address of the current machine without an argument. With an argument, it shows the IP of a named peer.",
+	ShortUsage: "ip [-1] [-4] [-6] [peer hostname or ip address]",
+	ShortHelp:  "Show Tailscale IP addresses",
+	LongHelp:   "Show Tailscale IP addresses for peer. Peer defaults to the current machine.",
 	Exec:       runIP,
 	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("ip", flag.ExitOnError)
+		fs := newFlagSet("ip")
+		fs.BoolVar(&ipArgs.want1, "1", false, "only print one IP address")
 		fs.BoolVar(&ipArgs.want4, "4", false, "only print IPv4 address")
 		fs.BoolVar(&ipArgs.want6, "6", false, "only print IPv6 address")
 		return fs
@@ -31,13 +31,14 @@ var ipCmd = &ffcli.Command{
 }
 
 var ipArgs struct {
+	want1 bool
 	want4 bool
 	want6 bool
 }
 
 func runIP(ctx context.Context, args []string) error {
 	if len(args) > 1 {
-		return errors.New("unknown arguments")
+		return errors.New("too many arguments, expected at most one peer")
 	}
 	var of string
 	if len(args) == 1 {
@@ -45,19 +46,25 @@ func runIP(ctx context.Context, args []string) error {
 	}
 
 	v4, v6 := ipArgs.want4, ipArgs.want6
-	if v4 && v6 {
-		return errors.New("tailscale up -4 and -6 are mutually exclusive")
+	nflags := 0
+	for _, b := range []bool{ipArgs.want1, v4, v6} {
+		if b {
+			nflags++
+		}
+	}
+	if nflags > 1 {
+		return errors.New("tailscale ip -1, -4, and -6 are mutually exclusive")
 	}
 	if !v4 && !v6 {
 		v4, v6 = true, true
 	}
-	st, err := tailscale.Status(ctx)
+	st, err := localClient.Status(ctx)
 	if err != nil {
 		return err
 	}
 	ips := st.TailscaleIPs
 	if of != "" {
-		ip, err := tailscaleIPFromArg(ctx, of)
+		ip, _, err := tailscaleIPFromArg(ctx, of)
 		if err != nil {
 			return err
 		}
@@ -71,11 +78,14 @@ func runIP(ctx context.Context, args []string) error {
 		return fmt.Errorf("no current Tailscale IPs; state: %v", st.BackendState)
 	}
 
+	if ipArgs.want1 {
+		ips = ips[:1]
+	}
 	match := false
 	for _, ip := range ips {
 		if ip.Is4() && v4 || ip.Is6() && v6 {
 			match = true
-			fmt.Println(ip)
+			outln(ip)
 		}
 	}
 	if !match {
@@ -90,7 +100,7 @@ func runIP(ctx context.Context, args []string) error {
 }
 
 func peerMatchingIP(st *ipnstate.Status, ipStr string) (ps *ipnstate.PeerStatus, ok bool) {
-	ip, err := netaddr.ParseIP(ipStr)
+	ip, err := netip.ParseAddr(ipStr)
 	if err != nil {
 		return
 	}
@@ -101,5 +111,12 @@ func peerMatchingIP(st *ipnstate.Status, ipStr string) (ps *ipnstate.PeerStatus,
 			}
 		}
 	}
+	if ps := st.Self; ps != nil {
+		for _, pip := range ps.TailscaleIPs {
+			if ip == pip {
+				return ps, true
+			}
+		}
+	}
 	return nil, false
 }

cmd/tailscale/cli/licenses.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"context"
+	"runtime"
+
+	"github.com/peterbourgon/ff/v3/ffcli"
+)
+
+var licensesCmd = &ffcli.Command{
+	Name:       "licenses",
+	ShortUsage: "licenses",
+	ShortHelp:  "Get open source license information",
+	LongHelp:   "Get open source license information",
+	Exec:       runLicenses,
+}
+
+func runLicenses(ctx context.Context, args []string) error {
+	var licenseURL string
+	switch runtime.GOOS {
+	case "android":
+		licenseURL = "https://tailscale.com/licenses/android"
+	case "darwin", "ios":
+		licenseURL = "https://tailscale.com/licenses/apple"
+	case "windows":
+		licenseURL = "https://tailscale.com/licenses/windows"
+	default:
+		licenseURL = "https://tailscale.com/licenses/tailscale"
+	}
+
+	outln(`
+Tailscale wouldn't be possible without the contributions of thousands of open
+source developers. To see the open source packages included in Tailscale and
+their respective license information, visit:
+
+    ` + licenseURL)
+	return nil
+}

cmd/tailscale/cli/logout.go

@@ -6,11 +6,10 @@ package cli
 
 import (
 	"context"
-	"log"
+	"fmt"
 	"strings"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/client/tailscale"
+	"github.com/peterbourgon/ff/v3/ffcli"
 )
 
 var logoutCmd = &ffcli.Command{
@@ -28,7 +27,7 @@ a reauthentication.
 
 func runLogout(ctx context.Context, args []string) error {
 	if len(args) > 0 {
-		log.Fatalf("too many non-flag arguments: %q", args)
+		return fmt.Errorf("too many non-flag arguments: %q", args)
 	}
-	return tailscale.Logout(ctx)
+	return localClient.Logout(ctx)
 }

cmd/tailscale/cli/nc.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cli
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+
+	"github.com/peterbourgon/ff/v3/ffcli"
+)
+
+var ncCmd = &ffcli.Command{
+	Name:       "nc",
+	ShortUsage: "nc <hostname-or-IP> <port>",
+	ShortHelp:  "Connect to a port on a host, connected to stdin/stdout",
+	Exec:       runNC,
+}
+
+func runNC(ctx context.Context, args []string) error {
+	st, err := localClient.Status(ctx)
+	if err != nil {
+		return fixTailscaledConnectError(err)
+	}
+	description, ok := isRunningOrStarting(st)
+	if !ok {
+		printf("%s\n", description)
+		os.Exit(1)
+	}
+
+	if len(args) != 2 {
+		return errors.New("usage: nc <hostname-or-IP> <port>")
+	}
+
+	hostOrIP, portStr := args[0], args[1]
+	port, err := strconv.ParseUint(portStr, 10, 16)
+	if err != nil {
+		return fmt.Errorf("invalid port number %q", portStr)
+	}
+
+	// TODO(bradfitz): also add UDP too, via flag?
+	c, err := localClient.DialTCP(ctx, hostOrIP, uint16(port))
+	if err != nil {
+		return fmt.Errorf("Dial(%q, %v): %w", hostOrIP, port, err)
+	}
+	defer c.Close()
+	errc := make(chan error, 1)
+	go func() {
+		_, err := io.Copy(os.Stdout, c)
+		errc <- err
+	}()
+	go func() {
+		_, err := io.Copy(c, os.Stdin)
+		errc <- err
+	}()
+	return <-errc
+}

cmd/tailscale/cli/netcheck.go

@@ -13,13 +13,12 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-	"os"
 	"sort"
 	"strings"
 	"time"
 
-	"github.com/peterbourgon/ff/v2/ffcli"
-	"tailscale.com/client/tailscale"
+	"github.com/peterbourgon/ff/v3/ffcli"
+	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/net/netcheck"
 	"tailscale.com/net/portmapper"
@@ -33,7 +32,7 @@ var netcheckCmd = &ffcli.Command{
 	ShortHelp:  "Print an analysis of local network conditions",
 	Exec:       runNetcheck,
 	FlagSet: (func() *flag.FlagSet {
-		fs := flag.NewFlagSet("netcheck", flag.ExitOnError)
+		fs := newFlagSet("netcheck")
 		fs.StringVar(&netcheckArgs.format, "format", "", `output format; empty (for human-readable), "json" or "json-line"`)
 		fs.DurationVar(&netcheckArgs.every, "every", 0, "if non-zero, do an incremental report with the given frequency")
 		fs.BoolVar(&netcheckArgs.verbose, "verbose", false, "verbose logs")
@@ -49,7 +48,7 @@ var netcheckArgs struct {
 
 func runNetcheck(ctx context.Context, args []string) error {
 	c := &netcheck.Client{
-		UDPBindAddr: os.Getenv("TS_DEBUG_NETCHECK_UDP_BIND"),
+		UDPBindAddr: envknob.String("TS_DEBUG_NETCHECK_UDP_BIND"),
 		PortMapper:  portmapper.NewClient(logger.WithPrefix(log.Printf, "portmap: "), nil),
 	}
 	if netcheckArgs.verbose {
@@ -60,11 +59,15 @@ func runNetcheck(ctx context.Context, args []string) error {
 	}
 
 	if strings.HasPrefix(netcheckArgs.format, "json") {
-		fmt.Fprintln(os.Stderr, "# Warning: this JSON format is not yet considered a stable interface")
+		fmt.Fprintln(Stderr, "# Warning: this JSON format is not yet considered a stable interface")
 	}
 
-	dm, err := tailscale.CurrentDERPMap(ctx)
-	if err != nil {
+	dm, err := localClient.CurrentDERPMap(ctx)
+	noRegions := dm != nil && len(dm.Regions) == 0
+	if noRegions {
+		log.Printf("No DERP map from tailscaled; using default.")
+	}
+	if err != nil || noRegions {
 		dm, err = prodDERPMap(ctx, http.DefaultClient)
 		if err != nil {
 			return err
@@ -78,7 +81,7 @@ func runNetcheck(ctx context.Context, args []string) error {
 			c.Logf("GetReport took %v; err=%v", d.Round(time.Millisecond), err)
 		}
 		if err != nil {
-			log.Fatalf("netcheck: %v", err)
+			return fmt.Errorf("netcheck: %w", err)
 		}
 		if err := printReport(dm, report); err != nil {
 			return err
@@ -108,36 +111,38 @@ func printReport(dm *tailcfg.DERPMap, report *netcheck.Report) error {
 	}
 	if j != nil {
 		j = append(j, '\n')
-		os.Stdout.Write(j)
+		Stdout.Write(j)
 		return nil
 	}
 
-	fmt.Printf("\nReport:\n")
-	fmt.Printf("\t* UDP: %v\n", report.UDP)
+	printf("\nReport:\n")
+	printf("\t* UDP: %v\n", report.UDP)
 	if report.GlobalV4 != "" {
-		fmt.Printf("\t* IPv4: yes, %v\n", report.GlobalV4)
+		printf("\t* IPv4: yes, %v\n", report.GlobalV4)
 	} else {
-		fmt.Printf("\t* IPv4: (no addr found)\n")
+		printf("\t* IPv4: (no addr found)\n")
 	}
 	if report.GlobalV6 != "" {
-		fmt.Printf("\t* IPv6: yes, %v\n", report.GlobalV6)
+		printf("\t* IPv6: yes, %v\n", report.GlobalV6)
 	} else if report.IPv6 {
-		fmt.Printf("\t* IPv6: (no addr found)\n")
+		printf("\t* IPv6: (no addr found)\n")
+	} else if report.OSHasIPv6 {
+		printf("\t* IPv6: no, but OS has support\n")
 	} else {
-		fmt.Printf("\t* IPv6: no\n")
+		printf("\t* IPv6: no, unavailable in OS\n")
 	}
-	fmt.Printf("\t* MappingVariesByDestIP: %v\n", report.MappingVariesByDestIP)
-	fmt.Printf("\t* HairPinning: %v\n", report.HairPinning)
-	fmt.Printf("\t* PortMapping: %v\n", portMapping(report))
+	printf("\t* MappingVariesByDestIP: %v\n", report.MappingVariesByDestIP)
+	printf("\t* HairPinning: %v\n", report.HairPinning)
+	printf("\t* PortMapping: %v\n", portMapping(report))
 
 	// When DERP latency checking failed,
 	// magicsock will try to pick the DERP server that
 	// most of your other nodes are also using
 	if len(report.RegionLatency) == 0 {
-		fmt.Printf("\t* Nearest DERP: unknown (no response to latency probes)\n")
+		printf("\t* Nearest DERP: unknown (no response to latency probes)\n")
 	} else {
-		fmt.Printf("\t* Nearest DERP: %v\n", dm.Regions[report.PreferredDERP].RegionName)
-		fmt.Printf("\t* DERP latency:\n")
+		printf("\t* Nearest DERP: %v\n", dm.Regions[report.PreferredDERP].RegionName)
+		printf("\t* DERP latency:\n")
 		var rids []int
 		for rid := range dm.Regions {
 			rids = append(rids, rid)
@@ -164,7 +169,7 @@ func printReport(dm *tailcfg.DERPMap, report *netcheck.Report) error {
 			if netcheckArgs.verbose {
 				derpNum = fmt.Sprintf("derp%d, ", rid)
 			}
-			fmt.Printf("\t\t- %3s: %-7s (%s%s)\n", r.RegionCode, latency, derpNum, r.RegionName)
+			printf("\t\t- %3s: %-7s (%s%s)\n", r.RegionCode, latency, derpNum, r.RegionName)
 		}
 	}
 	return nil