WIP: sassy demo

Signed-off-by: Brad Fitzpatrick <bradfitz@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

@@ -1,37 +0,0 @@
----
-name: Bug report
-about: Create a bug report
-title: ''
-labels: ''
-assignees: ''
-
----
-
-<!-- Please note, this template is for definite bugs, not requests for
-support. If you need help with Tailscale, please email
-support@tailscale.com. We don't provide support via Github issues. -->
-
-**Describe the bug**
-A clear and concise description of what the bug is.
-
-**To Reproduce**
-Steps to reproduce the behavior:
-1. Go to '...'
-2. Click on '....'
-3. Scroll down to '....'
-4. See error
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**Version information:**
- - Device: [e.g. iPhone X, laptop]
- - OS: [e.g. Windows, MacOS]
- - OS version: [e.g. Windows 10, Ubuntu 18.04]
- - Tailscale version: [e.g. 0.95-0]
-
-**Additional context**
-Add any other context about the problem here.

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,81 @@
+name: Bug report
+description: File a bug report. If you need help, contact support instead
+labels: [needs-triage, bug]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Need help with your tailnet? [Contact support](https://tailscale.com/contact/support) instead.
+        Otherwise, please check if your bug is [already filed](https://github.com/tailscale/tailscale/issues) before filing a new one.
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: What is the issue?
+      description: What happened? What did you expect to happen?
+    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: textarea
+    id: other-software
+    attributes:
+      label: Other software
+      description: What [other software](https://github.com/tailscale/tailscale/wiki/OtherSoftwareInterop) (networking, security, etc) are you running?
+    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: See the troubleshooting guide for help addressing common issues

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,26 +0,0 @@
----
-name: Feature request
-about: Suggest an idea for this project
-title: ''
-labels: ''
-assignees: ''
-
----
-
-**Is your feature request related to a problem? Please describe.**
-
-A clear and concise description of what the problem is. Ex. I'm always
-frustrated when [...]
-
-**Describe the solution you'd like**
-
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-
-A clear and concise description of any alternative solutions or
-features you've considered.
-
-**Additional context**
-
-Add any other context or screenshots about the feature request here.

.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: [] # was: [pull_request], but disabled in https://github.com/tailscale/tailscale/pull/7156
+
+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@v2
+      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@v2
+
+    # 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@v2

.github/workflows/coverage.yml

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

.github/workflows/cross-android.yml

@@ -0,0 +1,55 @@
+name: Android-Cross
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  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: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
+      id: go
+
+    - name: Android smoke build
+      # Super minimal Android build that doesn't even use CGO and doesn't build everything that's needed
+      # and is only arm64. But it's a smoke build: it's not meant to catch everything. But it'll catch
+      # some Android breakages early.
+      # TODO(bradfitz): better; see https://github.com/tailscale/tailscale/issues/4482
+      env:
+        GOOS: android
+        GOARCH: arm64
+      run: go install ./net/netns ./ipn/ipnlocal ./wgengine/magicsock/ ./wgengine/ ./wgengine/router/ ./wgengine/netstack ./util/dnsname/ ./ipn/ ./net/interfaces ./wgengine/router/ ./tailcfg/ ./types/logger/ ./net/dns ./hostinfo ./version
+
+    - 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/cross-darwin.yml

@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   build:
@@ -15,16 +20,15 @@ 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 +41,12 @@ 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

@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   build:
@@ -15,16 +20,15 @@ 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-loong64.yml

@@ -1,4 +1,4 @@
-name: staticcheck
+name: Loongnix-Cross
 
 on:
   push:
@@ -7,28 +7,39 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   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: 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
-      uses: actions/checkout@v1
+    - name: Loongnix build cmd
+      env:
+        GOOS: linux
+        GOARCH: loong64
+      run: go build ./cmd/...
 
-    - name: Run go vet
-      run: go vet ./...
-
-    - name: Print staticcheck version
-      run: go run honnef.co/go/tools/cmd/staticcheck -version
-
-    - name: Run staticcheck
-      run: "go run honnef.co/go/tools/cmd/staticcheck -- $(go list ./... | grep -v tempfork)"
+    - name: Loongnix build tests
+      env:
+        GOOS: linux
+        GOARCH: loong64
+      run: for d in $(go list -f '{{if .TestGoFiles}}{{.Dir}}{{end}}' ./... ); do (echo $d; cd $d && go test -c ); done
 
     - uses: k0kubun/action-slack@v2.0.0
       with:

.github/workflows/cross-openbsd.yml

@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   build:
@@ -15,16 +20,15 @@ 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

@@ -0,0 +1,58 @@
+name: Wasm-Cross
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  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: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
+      id: go
+
+    - name: Wasm client build
+      env:
+        GOOS: js
+        GOARCH: wasm
+      run: go build ./cmd/tsconnect/wasm ./cmd/tailscale/cli
+
+    - 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 --fast-compression build-pkg
+
+    - 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/cross-windows.yml

@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   build:
@@ -15,16 +20,15 @@ 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

@@ -7,22 +7,27 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+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@ad43dccb4d726ca8514126628bec209b8354b6dd #v4.1.4
+        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

@@ -0,0 +1,42 @@
+name: go generate
+
+on:
+  push:
+    branches:
+      - main
+      - "release-branch/*"
+  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 generate' is clean
+        run: |
+          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: |
+          ./tool/go mod tidy
+          echo
+          echo
+          git diff --name-only --exit-code || (echo "Please run 'go mod tidy'."; exit 1)

.github/workflows/license.yml

@@ -7,19 +7,24 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+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

@@ -0,0 +1,70 @@
+name: Linux race
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  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: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
+      id: go
+
+    - name: Build test wrapper
+      run: ./tool/go build -o /tmp/testwrapper ./cmd/testwrapper
+
+    - name: Basic build
+      run: go build ./cmd/...
+
+    - name: Run tests and benchmarks with -race flag on linux
+      run: go test -exec=/tmp/testwrapper -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: |
+          {
+            "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/linux.yml

@@ -7,29 +7,61 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     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 test wrapper
+      run: ./tool/go build -o /tmp/testwrapper ./cmd/testwrapper
+
+    - name: Build variants
+      run: |
+        go install --tags=ts_include_cli ./cmd/tailscaled
+        go install --tags=ts_omit_aws ./cmd/tailscaled
+
+    - name: Get QEMU
+      run: |
+        sudo apt-get -y update
+        sudo apt-get -y install qemu-user
+
     - name: Run tests on linux
-      run: go test ./...
+      run: go test -exec=/tmp/testwrapper -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:

.github/workflows/linux32.yml

@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   build:
@@ -15,21 +20,35 @@ 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 ./...
+      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:

.github/workflows/static-analysis.yml

@@ -0,0 +1,119 @@
+name: static-analysis
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+      - 'release-branch/*'
+
+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: |
+        OUT=$(go run golang.org/x/tools/cmd/goimports -d --format-only .)
+        [ -z "$OUT" ] || (echo "Not gofmt'ed: $OUT" && exit 1)
+    - uses: k0kubun/action-slack@v2.0.0
+      with:
+        payload: |
+          {
+            "attachments": [{
+              "text": "${{ 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: ${{ secrets.SLACK_WEBHOOK_URL }}
+      if: failure() && github.event_name == 'push'
+
+  vet:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
+
+    - name: Run go vet
+      run: go vet ./...
+
+    - uses: k0kubun/action-slack@v2.0.0
+      with:
+        payload: |
+          {
+            "attachments": [{
+              "text": "${{ 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: ${{ secrets.SLACK_WEBHOOK_URL }}
+      if: failure() && github.event_name == 'push'
+
+  staticcheck:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        goos: [linux, windows, darwin]
+        goarch: [amd64]
+        include:
+          - goos: windows
+            goarch: 386
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version-file: go.mod
+
+
+    - name: Install staticcheck
+      run: "GOBIN=~/.local/bin go install honnef.co/go/tools/cmd/staticcheck"
+
+    - name: Print staticcheck version
+      run: "staticcheck -version"
+
+    - name: "Run staticcheck (${{ 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/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

@@ -0,0 +1,51 @@
+name: VM
+
+on:
+  pull_request:
+    branches:
+      - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  ubuntu2004-LTS-cloud-base:
+    runs-on: [ self-hosted, linux, vm ]
+
+    if: "(github.repository == 'tailscale/tailscale') && !contains(github.event.head_commit.message, '[ci skip]')"
+
+    steps:
+      - name: Set GOPATH
+        run: echo "GOPATH=$HOME/go" >> $GITHUB_ENV
+
+      - name: Checkout Code
+        uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+
+      - name: Run VM tests
+        run: go test ./tstest/integration/vms -v -no-s3 -run-vm-tests -run=TestRunUbuntu2004
+        env:
+          HOME: "/tmp"
+          TMPDIR: "/tmp"
+          XDG_CACHE_HOME: "/var/lib/ghrunner/cache"
+
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ github.workflow }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ env.COMMIT_DATE }} #${{ env.COMMIT_NUMBER_OF_DAY }}> " +
+                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
+                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'push'

.github/workflows/windows.yml

@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - '*'
+      - 'release-branch/*'
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
 
 jobs:
   test:
@@ -15,25 +20,35 @@ 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
-      run: go test ./...
+      # Don't use -bench=. -benchtime=1x.
+      # Somewhere in the layers (powershell?)
+      # the equals signs cause great confusion.
+      run: go test -bench . -benchtime 1x ./...
 
     - uses: k0kubun/action-slack@v2.0.0
       with:

.gitignore

@@ -5,6 +5,7 @@
 *.dll
 *.so
 *.dylib
+*.spk
 
 cmd/tailscale/tailscale
 cmd/tailscaled/tailscaled
@@ -21,3 +22,9 @@ cmd/tailscaled/tailscaled
 # direnv config, this may be different for other people so it's probably safer
 # to make this nonspecific.
 .envrc
+
+# Ignore personal VS Code settings
+.vscode/
+
+# Ignore direnv nix-shell environment cache
+.direnv/

ALPINE.txt

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

Dockerfile

@@ -1,20 +1,13 @@
-# 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.
+# Copyright (c) Tailscale Inc & AUTHORS
+# SPDX-License-Identifier: BSD-3-Clause
 
 ############################################################################
 #
-# 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 +16,11 @@
 #
 # 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:
 #
@@ -38,14 +31,25 @@
 #     $ docker exec tailscaled tailscale status
 
 
-FROM golang:1.16-alpine AS build-env
+FROM golang:1.20-alpine AS build-env
 
 WORKDIR /go/src/tailscale
 
-COPY go.mod .
-COPY go.sum .
+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
@@ -55,13 +59,18 @@ 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 ./cmd/containerboot
+
+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/
+# For compat with the previous run.sh, although ideally you should be
+# using build_docker.sh which sets an entrypoint for the image.
+RUN ln -s /usr/local/bin/containerboot /tailscale/run.sh

Dockerfile.base

@@ -0,0 +1,5 @@
+# Copyright (c) Tailscale Inc & AUTHORS
+# SPDX-License-Identifier: BSD-3-Clause
+
+FROM alpine:3.16
+RUN apk add --no-cache ca-certificates iptables iproute2 ip6tables

LICENSE

@@ -1,7 +1,6 @@
 BSD 3-Clause License
 
-Copyright (c) 2020 Tailscale & AUTHORS.
-All rights reserved.
+Copyright (c) 2020 Tailscale Inc & AUTHORS.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

Makefile

@@ -1,24 +1,79 @@
+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
+	# depaware (via x/tools/go/packages) shells back to "go", so make sure the "go"
+	# it finds in its $$PATH is the right one.
+	PATH="$$(./tool/go env GOROOT)/bin:$$PATH" ./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
+	# depaware (via x/tools/go/packages) shells back to "go", so make sure the "go"
+	# it finds in its $$PATH is the right one.
+	PATH="$$(./tool/go env GOROOT)/bin:$$PATH" ./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
+
+buildlinuxloong64:
+	GOOS=linux GOARCH=loong64 ./tool/go install tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled
+
+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@${SYNO_HOST} /usr/syno/bin/synopkg install tailscale.spk
+
+publishdevimage:
+	@test -n "${REPO}" || (echo "REPO=... required; e.g. REPO=ghcr.io/${USER}/tailscale" && exit 1)
+	@test "${REPO}" != "tailscale/tailscale" || (echo "REPO=... must not be tailscale/tailscale" && exit 1)
+	@test "${REPO}" != "ghcr.io/tailscale/tailscale" || (echo "REPO=... must not be ghcr.io/tailscale/tailscale" && exit 1)
+	@test "${REPO}" != "tailscale/k8s-operator" || (echo "REPO=... must not be tailscale/k8s-operator" && exit 1)
+	@test "${REPO}" != "ghcr.io/tailscale/k8s-operator" || (echo "REPO=... must not be ghcr.io/tailscale/k8s-operator" && exit 1)
+	TAGS=latest REPOS=${REPO} PUSH=true TARGET=client ./build_docker.sh
+
+publishdevoperator:
+	@test -n "${REPO}" || (echo "REPO=... required; e.g. REPO=ghcr.io/${USER}/tailscale" && exit 1)
+	@test "${REPO}" != "tailscale/tailscale" || (echo "REPO=... must not be tailscale/tailscale" && exit 1)
+	@test "${REPO}" != "ghcr.io/tailscale/tailscale" || (echo "REPO=... must not be ghcr.io/tailscale/tailscale" && exit 1)
+	@test "${REPO}" != "tailscale/k8s-operator" || (echo "REPO=... must not be tailscale/k8s-operator" && exit 1)
+	@test "${REPO}" != "ghcr.io/tailscale/k8s-operator" || (echo "REPO=... must not be ghcr.io/tailscale/k8s-operator" && exit 1)
+	TAGS=latest REPOS=${REPO} PUSH=true TARGET=operator ./build_docker.sh

README.md

@@ -6,26 +6,41 @@ Private WireGuard® networks made easy
 
 ## Overview
 
-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.
+This repository contains the majority of Tailscale's open source code.
+Notably, it includes the `tailscaled` daemon and
+the `tailscale` CLI tool. The `tailscaled` daemon runs on Linux, Windows,
+[macOS](https://tailscale.com/kb/1065/macos-variants/), and to varying degrees
+on FreeBSD and OpenBSD. 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
+Other [Tailscale repos](https://github.com/orgs/tailscale/repositories) of note:
+
+* the Android app is at https://github.com/tailscale/tailscale-android
+* the Synology package is at https://github.com/tailscale/tailscale-synology
+* the QNAP package is at https://github.com/tailscale/tailscale-qpkg
+* the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
+
+For background on which parts of Tailscale are open source and why,
+see [https://tailscale.com/opensource/](https://tailscale.com/opensource/).
 
 ## Using
 
-We serve packages for a variety of distros at
-https://pkgs.tailscale.com .
+We serve packages for a variety of distros and platforms at
+[https://pkgs.tailscale.com](https://pkgs.tailscale.com/).
 
 ## Other clients
 
 The [macOS, iOS, and Windows clients](https://tailscale.com/download)
 use the code in this repository but additionally include small GUI
-wrappers that are not open source.
+wrappers. The GUI wrappers on non-open source platforms are themselves
+not open source.
 
 ## Building
 
+We always require the latest Go release, currently Go 1.20. (While we build
+releases with our [Go fork](https://github.com/tailscale/go/), its use is not
+required.)
+
 ```
 go install tailscale.com/cmd/tailscale{,d}
 ```
@@ -42,11 +57,6 @@ 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.
-
 ## Bugs
 
 Please file any issues about this code or the hosted service on
@@ -61,6 +71,9 @@ We require [Developer Certificate of
 Origin](https://en.wikipedia.org/wiki/Developer_Certificate_of_Origin)
 `Signed-off-by` lines in commits.
 
+See `git log` for our commit message style. It's basically the same as
+[Go's style](https://github.com/golang/go/wiki/CommitMessage).
+
 ## About Us
 
 [Tailscale](https://tailscale.com/) is primarily developed by the

VERSION.txt

@@ -1 +1 @@
-1.7.0
+1.37.0

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 console](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
 
@@ -233,12 +245,102 @@ Response
 }
 ```
 
-## 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.
+<a name=device-authorized-post></a>
 
+#### `POST /api/v2/device/:deviceID/authorized` - authorize a device
 
-`alice@example.com` belongs to the `example.com` tailnet and would use the following format for API calls:
+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 your private network, composed of all the devices on it and their configuration. For more information on tailnets, see [our user-facing documentation](https://tailscale.com/kb/1136/tailnet/).
+
+When making API requests, your tailnet is identified by the organization name. You can find it on the [Settings page](https://login.tailscale.com/admin/settings) of the admin console.
+
+For example, if `alice@example.com` belongs to the `example.com` tailnet, they would use the following format for API calls:
 
 ```
 GET /api/v2/tailnet/example.com/...
@@ -254,9 +356,14 @@ GET /api/v2/tailnet/alice@gmail.com/...
 curl https://api.tailscale.com/api/v2/tailnet/alice@gmail.com/...
 ```
 
-Tailnets are a top-level resource. ACL is an example of a resource that is tied to a top-level tailnet.
+Alternatively, you can specify the value "-" to refer to the default tailnet of
+the authenticated user making the API call.  For example:
+```
+GET /api/v2/tailnet/-/...
+curl https://api.tailscale.com/api/v2/tailnet/-/...
+```
 
-For more information on Tailscale networks/tailnets, click [here](https://tailscale.com/kb/1064/invite-team-members).
+Tailnets are a top-level resource. ACL is an example of a resource that is tied to a top-level tailnet.
 
 ### ACL
 
@@ -295,20 +402,20 @@ Etag: "e0b2816b418b3f266309d94426ac7668ab3c1fa87798785bf82f1085cc2f6d9c"
 
 // Example/default ACLs for unrestricted connections.
 {
-    "Tests": [],
+    "tests": [],
     // Declare static groups of users beyond those in the identity service.
-    "Groups": {
+    "groups": {
         "group:example": [
             "user1@example.com",
             "user2@example.com"
         ],
     },
     // Declare convenient hostname aliases to use in place of IP addresses.
-    "Hosts": {
+    "hosts": {
         "example-host-1": "100.100.100.100",
     },
     // Access control lists.
-    "ACLs": [
+    "acls": [
         // Match absolutely everything. Comment out this section if you want
         // to define specific ACL restrictions.
         {
@@ -367,20 +474,36 @@ Etag: "e0b2816b418b3f266309d94426ac7668ab3c1fa87798785bf82f1085cc2f6d9c"
 
 #### `POST /api/v2/tailnet/:tailnet/acl` - set ACL for a tailnet
 
-Sets the ACL for the given tailnet. HuJSON and JSON are both accepted inputs. An `If-Match` header can be set to avoid missed updates.
+Sets the ACL for the given domain.
+HuJSON and JSON are both accepted inputs.
+An `If-Match` header can be set to avoid missed updates.
 
-Returns error for invalid ACLs.
-Returns error if using an `If-Match` header and the ETag does not match.
+Returns the updated ACL in JSON or HuJSON according to the `Accept` header on success. Otherwise, errors are returned for incorrectly defined ACLs, ACLs with failing tests on attempted updates, and mismatched `If-Match` header and ETag.
 
 ##### Parameters
 
 ###### Headers
 `If-Match` - A request header. Set this value to the ETag header provided in an `ACL GET` request to avoid missed updates.
 
+A special value `ts-default` will ensure that ACL will be set only if current ACL is the default one (created automatically for each tailnet).
+
 `Accept` - Sets the return type of the updated ACL. Response is parsed `JSON` if `application/json` is explicitly named, otherwise HuJSON will be returned.
 
 ###### POST Body
-ACL JSON or HuJSON (see https://tailscale.com/kb/1018/acls)
+
+The POST body should be a JSON or [HuJSON](https://github.com/tailscale/hujson#hujson---human-json) formatted JSON object.
+An ACL policy may contain the following top-level properties:
+
+* `groups` - Static groups of users which can be used for ACL rules.
+* `hosts` - Hostname aliases to use in place of IP addresses or subnets.
+* `acls` - Access control lists.
+* `tagOwners` - Defines who is allowed to use which tags.
+* `tests` - Run on ACL updates to check correct functionality of defined ACLs.
+* `autoApprovers` - Defines which users can advertise routes or exit nodes without further approval.
+* `ssh` - Configures access policy for Tailscale SSH.
+* `nodeAttrs` - Defines which devices can use certain features.
+
+See https://tailscale.com/kb/1018/acls for more information on those properties.
 
 ##### Example
 ```
@@ -391,97 +514,180 @@ curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl' \
   --data-binary '// Example/default ACLs for unrestricted connections.
 {
   // Declare tests to check functionality of ACL rules. User must be a valid user with registered machines.
-  "Tests": [
-    // {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]},
+  "tests": [
+    // {"src": "user1@example.com", "accept": ["example-host-1:22"], "deny": ["example-host-2:100"]},
   ],
   // Declare static groups of users beyond those in the identity service.
-  "Groups": {
+  "groups": {
     "group:example": [ "user1@example.com", "user2@example.com" ],
   },
   // Declare convenient hostname aliases to use in place of IP addresses.
-  "Hosts": {
+  "hosts": {
     "example-host-1": "100.100.100.100",
   },
   // Access control lists.
-  "ACLs": [
+  "acls": [
     // Match absolutely everything. Comment out this section if you want
     // to define specific ACL restrictions.
-    { "Action": "accept", "Users": ["*"], "Ports": ["*:*"] },
+    { "action": "accept", "users": ["*"], "ports": ["*:*"] },
   ]
 }'
 ```
 
-Response
+Response:
 ```
 // Example/default ACLs for unrestricted connections.
 {
   // Declare tests to check functionality of ACL rules. User must be a valid user with registered machines.
-  "Tests": [
-    // {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]},
+  "tests": [
+    // {"src": "user1@example.com", "accept": ["example-host-1:22"], "deny": ["example-host-2:100"]},
   ],
   // Declare static groups of users beyond those in the identity service.
-  "Groups": {
+  "groups": {
     "group:example": [ "user1@example.com", "user2@example.com" ],
   },
   // Declare convenient hostname aliases to use in place of IP addresses.
-  "Hosts": {
+  "hosts": {
     "example-host-1": "100.100.100.100",
   },
   // Access control lists.
-  "ACLs": [
+  "acls": [
     // Match absolutely everything. Comment out this section if you want
     // to define specific ACL restrictions.
-    { "Action": "accept", "Users": ["*"], "Ports": ["*:*"] },
+    { "action": "accept", "users": ["*"], "ports": ["*:*"] },
   ]
 }
 ```
 
+Failed test error response:
+```
+{
+    "message": "test(s) failed",
+    "data": [
+        {
+            "user": "user1@example.com",
+            "errors": [
+                "address \"user2@example.com:400\": want: Accept, got: Drop"
+            ]
+        }
+    ]
+}
+```
+
 <a name=tailnet-acl-preview-post></a>
 
 #### `POST /api/v2/tailnet/:tailnet/acl/preview` - preview rule matches on an ACL for a resource
+
 Determines what rules match for a user on an ACL without saving the ACL to the server.
 
 ##### Parameters
 
 ###### Query Parameters
-`user` - A user's email. The provided ACL is queried with this user to determine which rules match.
+`type` - can be 'user' or 'ipport'
+`previewFor` - if type=user, a user's email. If type=ipport, a IP address + port like "10.0.0.1:80".
+The provided ACL is queried with this parameter to determine which rules match.
 
 ###### POST Body
 ACL JSON or HuJSON (see https://tailscale.com/kb/1018/acls)
 
 ##### Example
 ```
-POST /api/v2/tailnet/example.com/acl/preiew
-curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl?user=user1@example.com' \
+curl 'https://api.tailscale.com/api/v2/tailnet/example.com/acl/preview?previewFor=user1@example.com&type=user' \
   -u "tskey-yourapikey123:" \
   --data-binary '// Example/default ACLs for unrestricted connections.
 {
   // Declare tests to check functionality of ACL rules. User must be a valid user with registered machines.
-  "Tests": [
-    // {"User": "user1@example.com", "Allow": ["example-host-1:22"], "Deny": ["example-host-2:100"]},
+  "tests": [
+    // {"src": "user1@example.com", "accept": ["example-host-1:22"], "deny": ["example-host-2:100"]},
   ],
   // Declare static groups of users beyond those in the identity service.
-  "Groups": {
+  "groups": {
     "group:example": [ "user1@example.com", "user2@example.com" ],
   },
   // Declare convenient hostname aliases to use in place of IP addresses.
-  "Hosts": {
+  "hosts": {
     "example-host-1": "100.100.100.100",
   },
   // Access control lists.
-  "ACLs": [
+  "acls": [
     // Match absolutely everything. Comment out this section if you want
     // to define specific ACL restrictions.
-    { "Action": "accept", "Users": ["*"], "Ports": ["*:*"] },
+    { "action": "accept", "users": ["*"], "ports": ["*:*"] },
   ]
 }'
 ```
 
-Response
+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 '
+  [
+    {"src": "user1@example.com", "accept": ["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
@@ -489,7 +695,7 @@ 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.
 
@@ -498,7 +704,7 @@ 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`
@@ -518,7 +724,7 @@ curl 'https://api.tailscale.com/api/v2/tailnet/example.com/devices' \
   -u "tskey-yourapikey123:"
 ```
 
-Response 
+Response
 ```
 {
   "devices":[
@@ -568,6 +774,182 @@ 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.
+
+`expirySeconds` - (Optional) How long the key is valid for in seconds.
+                  Defaults to 90d.
+
+```
+{
+  "capabilities": {
+    "devices": {
+      "create": {
+        "reusable": false,
+        "ephemeral": false,
+        "preauthorized": false,
+        "tags": [
+          "tag:example"
+        ]
+      }
+    }
+  },
+  "expirySeconds": 1440
+}
+```
+
+##### 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
@@ -575,13 +957,13 @@ 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
@@ -589,7 +971,7 @@ curl 'https://api.tailscale.com/api/v2/tailnet/example.com/dns/nameservers' \
   -u "tskey-yourapikey123:"
 ```
 
-Response 
+Response
 ```
 {
   "dns": ["8.8.8.8"],
@@ -599,7 +981,7 @@ 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).
 
@@ -613,7 +995,7 @@ 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).
 
@@ -657,31 +1039,31 @@ 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
@@ -712,7 +1094,7 @@ If there are no DNS servers, it returns an error message:
 }
 ```
 
-If there are DNS servers: 
+If there are DNS servers:
 ```
 {
   "magicDNS":true,
@@ -721,8 +1103,8 @@ 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.
 
 
@@ -733,7 +1115,7 @@ 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:
@@ -745,7 +1127,7 @@ 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
@@ -754,7 +1136,7 @@ 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

@@ -1,6 +1,5 @@
-// Copyright (c) 2019 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 // Package atomicfile contains code related to writing to filesystems
 // atomically.
@@ -9,16 +8,15 @@
 package atomicfile // import "tailscale.com/atomicfile"
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
 )
 
 // 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")
+	f, err := os.CreateTemp(filepath.Dir(filename), filepath.Base(filename)+".tmp")
 	if err != nil {
 		return err
 	}

build_dist.sh

@@ -11,6 +11,59 @@
 
 set -eu
 
-eval $(./version/version.sh)
+IFS=".$IFS" read -r major minor patch <VERSION.txt
+git_hash=$(git rev-parse HEAD)
+if ! git diff-index --quiet HEAD; then
+	git_hash="${git_hash}-dirty"
+fi
+base_hash=$(git rev-list --max-count=1 HEAD -- VERSION.txt)
+change_count=$(git rev-list --count HEAD "^$base_hash")
+short_hash=$(echo "$git_hash" | cut -c1-9)
 
-exec go build -tags xversion -ldflags "-X tailscale.com/version.Long=${VERSION_LONG} -X tailscale.com/version.Short=${VERSION_SHORT} -X tailscale.com/version.GitCommit=${VERSION_GIT_HASH}" "$@"
+if expr "$minor" : "[0-9]*[13579]$" >/dev/null; then
+	patch="$change_count"
+	change_suffix=""
+elif [ "$change_count" != "0" ]; then
+	change_suffix="-$change_count"
+else
+	change_suffix=""
+fi
+
+long_suffix="$change_suffix-t$short_hash"
+MINOR="$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="$GIT_HASH"
+EOF
+	exit 0
+fi
+
+tags=""
+ldflags="-X tailscale.com/version.Long=${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,ts_omit_bird,ts_omit_tap"
+		;;
+	--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 +8,67 @@
 #
 ############################################################################
 #
-# 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 $(./version/version.sh)
+# Use the "go" binary from the "tool" directory (which is github.com/tailscale/go)
+export PATH=$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 $(./build_dist.sh shellvars)
+
+DEFAULT_TARGET="client"
+DEFAULT_TAGS="v${VERSION_SHORT},v${VERSION_MINOR}"
+DEFAULT_BASE="tailscale/alpine-base:3.16"
+
+PUSH="${PUSH:-false}"
+TARGET="${TARGET:-${DEFAULT_TARGET}}"
+TAGS="${TAGS:-${DEFAULT_TAGS}}"
+BASE="${BASE:-${DEFAULT_BASE}}"
+
+case "$TARGET" in
+  client)
+    DEFAULT_REPOS="tailscale/tailscale"
+    REPOS="${REPOS:-${DEFAULT_REPOS}}"
+    go run github.com/tailscale/mkctr \
+      --gopaths="\
+        tailscale.com/cmd/tailscale:/usr/local/bin/tailscale, \
+        tailscale.com/cmd/tailscaled:/usr/local/bin/tailscaled, \
+        tailscale.com/cmd/containerboot:/usr/local/bin/containerboot" \
+      --ldflags="\
+        -X tailscale.com/version.Long=${VERSION_LONG} \
+        -X tailscale.com/version.Short=${VERSION_SHORT} \
+        -X tailscale.com/version.GitCommit=${VERSION_GIT_HASH}" \
+      --base="${BASE}" \
+      --tags="${TAGS}" \
+      --repos="${REPOS}" \
+      --push="${PUSH}" \
+      /usr/local/bin/containerboot
+    ;;
+  operator)
+    DEFAULT_REPOS="tailscale/k8s-operator"
+    REPOS="${REPOS:-${DEFAULT_REPOS}}"
+    go run github.com/tailscale/mkctr \
+      --gopaths="tailscale.com/cmd/k8s-operator:/usr/local/bin/operator" \
+      --ldflags="\
+        -X tailscale.com/version.Long=${VERSION_LONG} \
+        -X tailscale.com/version.Short=${VERSION_SHORT} \
+        -X tailscale.com/version.GitCommit=${VERSION_GIT_HASH}" \
+      --base="${BASE}" \
+      --tags="${TAGS}" \
+      --repos="${REPOS}" \
+      --push="${PUSH}" \
+      /usr/local/bin/operator
+    ;;
+  *)
+    echo "unknown target: $TARGET"
+    exit 1
+    ;;
+esac

chirp/chirp.go

@@ -0,0 +1,163 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// 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, err error) {
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to BIRD: %w", err)
+	}
+	defer func() {
+		if err != nil {
+			conn.Close()
+		}
+	}()
+
+	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 +1,192 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+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 succeeded", "rando")
+	}
+	if err := c.DisableProtocol("rando"); err == nil {
+		t.Fatalf("disabling %q succeeded", "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 +1,475 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go: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 responded 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

@@ -0,0 +1,40 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package apitype contains types for the Tailscale LocalAPI and control plane API.
+package apitype
+
+import "tailscale.com/tailcfg"
+
+// LocalAPIHost is the Host header value used by the LocalAPI.
+const LocalAPIHost = "local-tailscaled.sock"
+
+// WhoIsResponse is the JSON type returned by tailscaled debug server's /whois?ip=$IP handler.
+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
+// URL base to do so via.
+type FileTarget struct {
+	Node *tailcfg.Node
+
+	// PeerAPI is the http://ip:port URL base of the node's PeerAPI,
+	// without any path (not even a single slash).
+	PeerAPIURL string
+}
+
+type WaitingFile struct {
+	Name string
+	Size int64
+}
+
+// SetPushDeviceTokenRequest is the body POSTed to the LocalAPI endpoint /set-device-token.
+type SetPushDeviceTokenRequest struct {
+	// PushDeviceToken is the iOS/macOS APNs device token (and any future Android equivalent).
+	PushDeviceToken string
+}

client/tailscale/apitype/controltype.go

@@ -0,0 +1,18 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+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"`
+}
+
+type DNSResolver struct {
+	Addr                string   `json:"addr"`
+	BootstrapResolution []string `json:"bootstrapResolution,omitempty"`
+}

client/tailscale/devices.go

@@ -0,0 +1,260 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go: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 +1,233 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go: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 +1,28 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// 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/keys.go

@@ -0,0 +1,146 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package tailscale
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// Key represents a Tailscale API or auth key.
+type Key struct {
+	ID           string          `json:"id"`
+	Created      time.Time       `json:"created"`
+	Expires      time.Time       `json:"expires"`
+	Capabilities KeyCapabilities `json:"capabilities"`
+}
+
+// KeyCapabilities are the capabilities of a Key.
+type KeyCapabilities struct {
+	Devices KeyDeviceCapabilities `json:"devices,omitempty"`
+}
+
+// KeyDeviceCapabilities are the device-related capabilities of a Key.
+type KeyDeviceCapabilities struct {
+	Create KeyDeviceCreateCapabilities `json:"create"`
+}
+
+// KeyDeviceCreateCapabilities are the device creation capabilities of a Key.
+type KeyDeviceCreateCapabilities struct {
+	Reusable      bool     `json:"reusable"`
+	Ephemeral     bool     `json:"ephemeral"`
+	Preauthorized bool     `json:"preauthorized"`
+	Tags          []string `json:"tags,omitempty"`
+}
+
+// Keys returns the list of keys for the current user.
+func (c *Client) Keys(ctx context.Context) ([]string, error) {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/keys", c.baseURL(), c.tailnet)
+	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 resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	var keys struct {
+		Keys []*Key `json:"keys"`
+	}
+	if err := json.Unmarshal(b, &keys); err != nil {
+		return nil, err
+	}
+	ret := make([]string, 0, len(keys.Keys))
+	for _, k := range keys.Keys {
+		ret = append(ret, k.ID)
+	}
+	return ret, nil
+}
+
+// CreateKey creates a new key for the current user. Currently, only auth keys
+// can be created. Returns the key itself, which cannot be retrieved again
+// later, and the key metadata.
+func (c *Client) CreateKey(ctx context.Context, caps KeyCapabilities) (string, *Key, error) {
+	keyRequest := struct {
+		Capabilities KeyCapabilities `json:"capabilities"`
+	}{caps}
+	bs, err := json.Marshal(keyRequest)
+	if err != nil {
+		return "", nil, err
+	}
+
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/keys", c.baseURL(), c.tailnet)
+	req, err := http.NewRequestWithContext(ctx, "POST", path, bytes.NewReader(bs))
+	if err != nil {
+		return "", nil, err
+	}
+
+	b, resp, err := c.sendRequest(req)
+	if err != nil {
+		return "", nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return "", nil, handleErrorResponse(b, resp)
+	}
+
+	var key struct {
+		Key
+		Secret string `json:"key"`
+	}
+	if err := json.Unmarshal(b, &key); err != nil {
+		return "", nil, err
+	}
+	return key.Secret, &key.Key, nil
+}
+
+// Key returns the metadata for the given key ID. Currently, capabilities are
+// only returned for auth keys, API keys only return general metadata.
+func (c *Client) Key(ctx context.Context, id string) (*Key, error) {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/keys/%s", c.baseURL(), c.tailnet, id)
+	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 resp.StatusCode != http.StatusOK {
+		return nil, handleErrorResponse(b, resp)
+	}
+
+	var key Key
+	if err := json.Unmarshal(b, &key); err != nil {
+		return nil, err
+	}
+	return &key, nil
+}
+
+// DeleteKey deletes the key with the given ID.
+func (c *Client) DeleteKey(ctx context.Context, id string) error {
+	path := fmt.Sprintf("%s/api/v2/tailnet/%s/keys/%s", c.baseURL(), c.tailnet, id)
+	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 resp.StatusCode != http.StatusOK {
+		return handleErrorResponse(b, resp)
+	}
+	return nil
+}

client/tailscale/localclient_test.go

@@ -0,0 +1,27 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build go1.19
+
+package tailscale
+
+import "testing"
+
+func TestGetServeConfigFromJSON(t *testing.T) {
+	sc, err := getServeConfigFromJSON([]byte("null"))
+	if sc != nil {
+		t.Errorf("want nil for null")
+	}
+	if err != nil {
+		t.Errorf("reading null: %v", err)
+	}
+
+	sc, err = getServeConfigFromJSON([]byte(`{"TCP":{}}`))
+	if err != nil {
+		t.Errorf("reading object: %v", err)
+	} else if sc == nil {
+		t.Errorf("want non-nil for object")
+	} else if sc.TCP == nil {
+		t.Errorf("want non-nil TCP for object")
+	}
+}

client/tailscale/required_version.go

@@ -0,0 +1,10 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !go1.20
+
+package tailscale
+
+func init() {
+	you_need_Go_1_20_to_compile_Tailscale()
+}

client/tailscale/routes.go

@@ -0,0 +1,95 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go: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) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build go1.19
+
+package tailscale
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"tailscale.com/util/httpm"
+)
+
+// 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, httpm.DELETE, 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

@@ -1,204 +1,157 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
-// Package tailscale contains Tailscale client code.
+//go:build go1.19
+
+// Package tailscale contains Go clients for the Tailscale LocalAPI 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 (
-	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
-	"net"
 	"net/http"
-	"net/url"
-	"strconv"
-
-	"tailscale.com/ipn/ipnstate"
-	"tailscale.com/paths"
-	"tailscale.com/safesocket"
-	"tailscale.com/tailcfg"
 )
 
-// TailscaledSocket is the tailscaled Unix socket.
-var TailscaledSocket = paths.DefaultTailscaledSocket()
-
-// tsClient does HTTP requests to the local Tailscale daemon.
-var tsClient = &http.Client{
-	Transport: &http.Transport{
-		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-			if addr != "local-tailscaled.sock:80" {
-				return nil, fmt.Errorf("unexpected URL address %q", addr)
-			}
-			if TailscaledSocket == paths.DefaultTailscaledSocket() {
-				// On macOS, when dialing from non-sandboxed program to sandboxed GUI running
-				// a TCP server on a random port, find the random port. For HTTP connections,
-				// we don't send the token. It gets added in an HTTP Basic-Auth header.
-				if port, _, err := safesocket.LocalTCPPortAndToken(); err == nil {
-					var d net.Dialer
-					return d.DialContext(ctx, "tcp", "localhost:"+strconv.Itoa(port))
-				}
-			}
-			return safesocket.Connect(TailscaledSocket, 41112)
-		},
-	},
-}
-
-// DoLocalRequest makes an HTTP request to the local machine's Tailscale daemon.
+// 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)
-	}
-	return tsClient.Do(req)
+// Most users will use AuthKey.
+type AuthMethod interface {
+	modifyRequest(req *http.Request)
 }
 
-// WhoIs returns the owner of the remoteAddr, which must be an IP or IP:port.
-func WhoIs(ctx context.Context, remoteAddr string) (*tailcfg.WhoIsResponse, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/whois?addr="+url.QueryEscape(remoteAddr), nil)
-	if err != nil {
-		return nil, err
-	}
-	res, err := DoLocalRequest(req)
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-	slurp, _ := ioutil.ReadAll(res.Body)
-	if res.StatusCode != 200 {
-		return nil, fmt.Errorf("HTTP %s: %s", res.Status, slurp)
-	}
-	r := new(tailcfg.WhoIsResponse)
-	if err := json.Unmarshal(slurp, r); err != nil {
-		if max := 200; len(slurp) > max {
-			slurp = slurp[:max]
-		}
-		return nil, fmt.Errorf("failed to parse JSON WhoIsResponse from %q", slurp)
-	}
-	return r, nil
+// 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), "")
 }
 
-// Goroutines returns a dump of the Tailscale daemon's current goroutines.
-func Goroutines(ctx context.Context) ([]byte, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/goroutines", nil)
-	if err != nil {
-		return nil, err
+func (c *Client) setAuth(r *http.Request) {
+	if c.auth != nil {
+		c.auth.modifyRequest(r)
 	}
-	res, err := DoLocalRequest(req)
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-	body, err := ioutil.ReadAll(res.Body)
-	if err != nil {
-		return nil, err
-	}
-	if res.StatusCode != 200 {
-		return nil, fmt.Errorf("HTTP %s: %s", res.Status, body)
-	}
-	return body, nil
 }
 
-// Status returns the Tailscale daemon's status.
-func Status(ctx context.Context) (*ipnstate.Status, error) {
-	return status(ctx, "")
+// 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,
+	}
 }
 
-// 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 (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)
 }
 
-func status(ctx context.Context, queryString string) (*ipnstate.Status, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/status"+queryString, nil)
+// sendRequest add the authentication 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 := io.ReadAll(body)
+	if len(b) > maxReadSize {
+		err = errors.New("API response too large")
 	}
-	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		body, _ := ioutil.ReadAll(res.Body)
-		return nil, fmt.Errorf("HTTP %s: %s", res.Status, body)
-	}
-	st := new(ipnstate.Status)
-	if err := json.NewDecoder(res.Body).Decode(st); err != nil {
-		return nil, err
-	}
-	return st, nil
+	return b, resp, err
 }
 
-type WaitingFile struct {
-	Name string
-	Size int64
+// ErrResponse is the HTTP error returned by the Tailscale server.
+type ErrResponse struct {
+	Status  int
+	Message string
 }
 
-func WaitingFiles(ctx context.Context) ([]WaitingFile, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", "http://local-tailscaled.sock/localapi/v0/files/", nil)
-	if err != nil {
-		return nil, err
-	}
-	res, err := DoLocalRequest(req)
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		body, _ := ioutil.ReadAll(res.Body)
-		return nil, fmt.Errorf("HTTP %s: %s", res.Status, body)
-	}
-	var wfs []WaitingFile
-	if err := json.NewDecoder(res.Body).Decode(&wfs); err != nil {
-		return nil, err
-	}
-	return wfs, nil
+func (e ErrResponse) Error() string {
+	return fmt.Sprintf("Status: %d, Message: %q", e.Status, e.Message)
 }
 
-func DeleteWaitingFile(ctx context.Context, baseName string) error {
-	req, err := http.NewRequestWithContext(ctx, "DELETE", "http://local-tailscaled.sock/localapi/v0/files/"+url.PathEscape(baseName), nil)
-	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
 	}
-	res, err := DoLocalRequest(req)
-	if err != nil {
-		return err
-	}
-	defer res.Body.Close()
-	if res.StatusCode != http.StatusNoContent {
-		body, _ := ioutil.ReadAll(res.Body)
-		return fmt.Errorf("expected 204 No Content; got HTTP %s: %s", res.Status, body)
-	}
-	return nil
-}
-
-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("expected 204 No Content; got HTTP %s: %s", res.Status, body)
-	}
-	return res.Body, res.ContentLength, nil
+	errResp.Status = resp.StatusCode
+	return errResp
 }

cmd/addlicense/main.go

@@ -0,0 +1,73 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Program addlicense adds a license header to a file.
+// It is intended for use with 'go generate',
+// so it has a slightly weird usage.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+var (
+	file = flag.String("file", "", "file to modify")
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, `
+usage: addlicense -file FILE <subcommand args...>
+`[1:])
+
+	flag.PrintDefaults()
+	fmt.Fprintf(os.Stderr, `
+addlicense adds a Tailscale license to the beginning of file.
+
+It is intended for use with 'go generate', so it also runs a subcommand,
+which presumably creates the file.
+
+Sample usage:
+
+addlicense -file pull_strings.go stringer -type=pull
+`[1:])
+	os.Exit(2)
+}
+
+func main() {
+	flag.Usage = usage
+	flag.Parse()
+	if len(flag.Args()) == 0 {
+		flag.Usage()
+	}
+	cmd := exec.Command(flag.Arg(0), flag.Args()[1:]...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	err := cmd.Run()
+	check(err)
+	b, err := os.ReadFile(*file)
+	check(err)
+	f, err := os.OpenFile(*file, os.O_TRUNC|os.O_WRONLY, 0644)
+	check(err)
+	_, err = fmt.Fprint(f, license)
+	check(err)
+	_, err = f.Write(b)
+	check(err)
+	err = f.Close()
+	check(err)
+}
+
+func check(err error) {
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+var license = `
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+`[1:]

cmd/cloner/cloner.go

@@ -1,6 +1,5 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 // Cloner is a tool to automate the creation of a Clone method.
 //
@@ -17,21 +16,16 @@ 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 +40,28 @@ 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)
@@ -120,154 +78,117 @@ 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("\t\t" + `panic("TODO map value pointers")`)
-				} 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:
@@ -276,34 +197,3 @@ 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/containerboot/kube.go

@@ -0,0 +1,277 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build linux
+
+package main
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"tailscale.com/tailcfg"
+	"tailscale.com/util/multierr"
+)
+
+// checkSecretPermissions checks the secret access permissions of the current
+// pod. It returns an error if the basic permissions tailscale needs are
+// missing, and reports whether the patch permission is additionally present.
+//
+// Errors encountered during the access checking process are logged, but ignored
+// so that the pod tries to fail alive if the permissions exist and there's just
+// something wrong with SelfSubjectAccessReviews. There shouldn't be, pods
+// should always be able to use SSARs to assess their own permissions, but since
+// we didn't use to check permissions this way we'll be cautious in case some
+// old version of k8s deviates from the current behavior.
+func checkSecretPermissions(ctx context.Context, secretName string) (canPatch bool, err error) {
+	var errs []error
+	for _, verb := range []string{"get", "update"} {
+		ok, err := checkPermission(ctx, verb, secretName)
+		if err != nil {
+			log.Printf("error checking %s permission on secret %s: %v", verb, secretName, err)
+		} else if !ok {
+			errs = append(errs, fmt.Errorf("missing %s permission on secret %q", verb, secretName))
+		}
+	}
+	if len(errs) > 0 {
+		return false, multierr.New(errs...)
+	}
+	ok, err := checkPermission(ctx, "patch", secretName)
+	if err != nil {
+		log.Printf("error checking patch permission on secret %s: %v", secretName, err)
+		return false, nil
+	}
+	return ok, nil
+}
+
+// checkPermission reports whether the current pod has permission to use the
+// given verb (e.g. get, update, patch) on secretName.
+func checkPermission(ctx context.Context, verb, secretName string) (bool, error) {
+	sar := map[string]any{
+		"apiVersion": "authorization.k8s.io/v1",
+		"kind":       "SelfSubjectAccessReview",
+		"spec": map[string]any{
+			"resourceAttributes": map[string]any{
+				"namespace": kubeNamespace,
+				"verb":      verb,
+				"resource":  "secrets",
+				"name":      secretName,
+			},
+		},
+	}
+	bs, err := json.Marshal(sar)
+	if err != nil {
+		return false, err
+	}
+	req, err := http.NewRequest("POST", "/apis/authorization.k8s.io/v1/selfsubjectaccessreviews", bytes.NewReader(bs))
+	if err != nil {
+		return false, err
+	}
+	resp, err := doKubeRequest(ctx, req)
+	if err != nil {
+		return false, err
+	}
+	defer resp.Body.Close()
+	bs, err = io.ReadAll(resp.Body)
+	if err != nil {
+		return false, err
+	}
+	var res struct {
+		Status struct {
+			Allowed bool `json:"allowed"`
+		} `json:"status"`
+	}
+	if err := json.Unmarshal(bs, &res); err != nil {
+		return false, err
+	}
+	return res.Status.Allowed, nil
+}
+
+// findKeyInKubeSecret inspects the kube secret secretName for a data
+// field called "authkey", and returns its value if present.
+func findKeyInKubeSecret(ctx context.Context, secretName string) (string, error) {
+	req, err := http.NewRequest("GET", fmt.Sprintf("/api/v1/namespaces/%s/secrets/%s", kubeNamespace, secretName), nil)
+	if err != nil {
+		return "", err
+	}
+	resp, err := doKubeRequest(ctx, req)
+	if err != nil {
+		if resp != nil && resp.StatusCode == http.StatusNotFound {
+			// Kube secret doesn't exist yet, can't have an authkey.
+			return "", nil
+		}
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	bs, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	// We use a map[string]any here rather than import corev1.Secret,
+	// because we only do very limited things to the secret, and
+	// importing corev1 adds 12MiB to the compiled binary.
+	var s map[string]any
+	if err := json.Unmarshal(bs, &s); err != nil {
+		return "", err
+	}
+	if d, ok := s["data"].(map[string]any); ok {
+		if v, ok := d["authkey"].(string); ok {
+			bs, err := base64.StdEncoding.DecodeString(v)
+			if err != nil {
+				return "", err
+			}
+			return string(bs), nil
+		}
+	}
+	return "", nil
+}
+
+// storeDeviceInfo writes deviceID into the "device_id" data field of the kube
+// secret secretName.
+func storeDeviceInfo(ctx context.Context, secretName string, deviceID tailcfg.StableNodeID, fqdn string) error {
+	// First check if the secret exists at all. Even if running on
+	// kubernetes, we do not necessarily store state in a k8s secret.
+	req, err := http.NewRequest("GET", fmt.Sprintf("/api/v1/namespaces/%s/secrets/%s", kubeNamespace, secretName), nil)
+	if err != nil {
+		return err
+	}
+	resp, err := doKubeRequest(ctx, req)
+	if err != nil {
+		if resp != nil && resp.StatusCode >= 400 && resp.StatusCode <= 499 {
+			// Assume the secret doesn't exist, or we don't have
+			// permission to access it.
+			return nil
+		}
+		return err
+	}
+
+	m := map[string]map[string]string{
+		"stringData": {
+			"device_id":   string(deviceID),
+			"device_fqdn": fqdn,
+		},
+	}
+	var b bytes.Buffer
+	if err := json.NewEncoder(&b).Encode(m); err != nil {
+		return err
+	}
+	req, err = http.NewRequest("PATCH", fmt.Sprintf("/api/v1/namespaces/%s/secrets/%s?fieldManager=tailscale-container", kubeNamespace, secretName), &b)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/strategic-merge-patch+json")
+	if _, err := doKubeRequest(ctx, req); err != nil {
+		return err
+	}
+	return nil
+}
+
+// deleteAuthKey deletes the 'authkey' field of the given kube
+// secret. No-op if there is no authkey in the secret.
+func deleteAuthKey(ctx context.Context, secretName string) error {
+	// m is a JSON Patch data structure, see https://jsonpatch.com/ or RFC 6902.
+	m := []struct {
+		Op   string `json:"op"`
+		Path string `json:"path"`
+	}{
+		{
+			Op:   "remove",
+			Path: "/data/authkey",
+		},
+	}
+	var b bytes.Buffer
+	if err := json.NewEncoder(&b).Encode(m); err != nil {
+		return err
+	}
+	req, err := http.NewRequest("PATCH", fmt.Sprintf("/api/v1/namespaces/%s/secrets/%s?fieldManager=tailscale-container", kubeNamespace, secretName), &b)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json-patch+json")
+	if resp, err := doKubeRequest(ctx, req); err != nil {
+		if resp != nil && resp.StatusCode == http.StatusUnprocessableEntity {
+			// This is kubernetes-ese for "the field you asked to
+			// delete already doesn't exist", aka no-op.
+			return nil
+		}
+		return err
+	}
+	return nil
+}
+
+var (
+	kubeHost      string
+	kubeNamespace string
+	kubeToken     string
+	kubeHTTP      *http.Transport
+)
+
+func initKube(root string) {
+	// If running in Kubernetes, set things up so that doKubeRequest
+	// can talk successfully to the kube apiserver.
+	if os.Getenv("KUBERNETES_SERVICE_HOST") == "" {
+		return
+	}
+
+	kubeHost = os.Getenv("KUBERNETES_SERVICE_HOST") + ":" + os.Getenv("KUBERNETES_SERVICE_PORT_HTTPS")
+
+	bs, err := os.ReadFile(filepath.Join(root, "var/run/secrets/kubernetes.io/serviceaccount/namespace"))
+	if err != nil {
+		log.Fatalf("Error reading kube namespace: %v", err)
+	}
+	kubeNamespace = strings.TrimSpace(string(bs))
+
+	bs, err = os.ReadFile(filepath.Join(root, "var/run/secrets/kubernetes.io/serviceaccount/token"))
+	if err != nil {
+		log.Fatalf("Error reading kube token: %v", err)
+	}
+	kubeToken = strings.TrimSpace(string(bs))
+
+	bs, err = os.ReadFile(filepath.Join(root, "var/run/secrets/kubernetes.io/serviceaccount/ca.crt"))
+	if err != nil {
+		log.Fatalf("Error reading kube CA cert: %v", err)
+	}
+	cp := x509.NewCertPool()
+	cp.AppendCertsFromPEM(bs)
+	kubeHTTP = &http.Transport{
+		TLSClientConfig: &tls.Config{
+			RootCAs: cp,
+		},
+		IdleConnTimeout: time.Second,
+	}
+}
+
+// doKubeRequest sends r to the kube apiserver.
+func doKubeRequest(ctx context.Context, r *http.Request) (*http.Response, error) {
+	if kubeHTTP == nil {
+		panic("not in kubernetes")
+	}
+
+	r.URL.Scheme = "https"
+	r.URL.Host = kubeHost
+	r.Header.Set("Authorization", "Bearer "+kubeToken)
+	r.Header.Set("Accept", "application/json")
+
+	resp, err := kubeHTTP.RoundTrip(r)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
+		return resp, fmt.Errorf("got non-200/201 status code %d", resp.StatusCode)
+	}
+	return resp, nil
+}

cmd/containerboot/main.go

@@ -0,0 +1,578 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build linux
+
+// The containerboot binary is a wrapper for starting tailscaled in a container.
+// It handles reading the desired mode of operation out of environment
+// variables, bringing up and authenticating Tailscale, and any other
+// kubernetes-specific side jobs.
+//
+// As with most container things, configuration is passed through environment
+// variables. All configuration is optional.
+//
+//   - TS_AUTHKEY: the authkey to use for login.
+//   - TS_HOSTNAME: the hostname to request for the node.
+//   - TS_ROUTES: subnet routes to advertise.
+//   - TS_DEST_IP: proxy all incoming Tailscale traffic to the given
+//     destination.
+//   - TS_TAILSCALED_EXTRA_ARGS: extra arguments to 'tailscaled'.
+//   - TS_EXTRA_ARGS: extra arguments to 'tailscale up'.
+//   - TS_USERSPACE: run with userspace networking (the default)
+//     instead of kernel networking.
+//   - TS_STATE_DIR: the directory in which to store tailscaled
+//     state. The data should persist across container
+//     restarts.
+//   - TS_ACCEPT_DNS: whether to use the tailnet's DNS configuration.
+//   - TS_KUBE_SECRET: the name of the Kubernetes secret in which to
+//     store tailscaled state.
+//   - TS_SOCKS5_SERVER: the address on which to listen for SOCKS5
+//     proxying into the tailnet.
+//   - TS_OUTBOUND_HTTP_PROXY_LISTEN: the address on which to listen
+//     for HTTP proxying into the tailnet.
+//   - TS_SOCKET: the path where the tailscaled LocalAPI socket should
+//     be created.
+//   - TS_AUTH_ONCE: if true, only attempt to log in if not already
+//     logged in. If false (the default, for backwards
+//     compatibility), forcibly log in every time the
+//     container starts.
+//
+// When running on Kubernetes, containerboot defaults to storing state in the
+// "tailscale" kube secret. To store state on local disk instead, set
+// TS_KUBE_SECRET="" and TS_STATE_DIR=/path/to/storage/dir. The state dir should
+// be persistent storage.
+//
+// Additionally, if TS_AUTHKEY is not set and the TS_KUBE_SECRET contains an
+// "authkey" field, that key is used as the tailscale authkey.
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io/fs"
+	"log"
+	"net/netip"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+	"tailscale.com/client/tailscale"
+	"tailscale.com/ipn"
+	"tailscale.com/util/deephash"
+)
+
+func main() {
+	log.SetPrefix("boot: ")
+	tailscale.I_Acknowledge_This_API_Is_Unstable = true
+
+	cfg := &settings{
+		AuthKey:         defaultEnvs([]string{"TS_AUTHKEY", "TS_AUTH_KEY"}, ""),
+		Hostname:        defaultEnv("TS_HOSTNAME", ""),
+		Routes:          defaultEnv("TS_ROUTES", ""),
+		ProxyTo:         defaultEnv("TS_DEST_IP", ""),
+		DaemonExtraArgs: defaultEnv("TS_TAILSCALED_EXTRA_ARGS", ""),
+		ExtraArgs:       defaultEnv("TS_EXTRA_ARGS", ""),
+		InKubernetes:    os.Getenv("KUBERNETES_SERVICE_HOST") != "",
+		UserspaceMode:   defaultBool("TS_USERSPACE", true),
+		StateDir:        defaultEnv("TS_STATE_DIR", ""),
+		AcceptDNS:       defaultBool("TS_ACCEPT_DNS", false),
+		KubeSecret:      defaultEnv("TS_KUBE_SECRET", "tailscale"),
+		SOCKSProxyAddr:  defaultEnv("TS_SOCKS5_SERVER", ""),
+		HTTPProxyAddr:   defaultEnv("TS_OUTBOUND_HTTP_PROXY_LISTEN", ""),
+		Socket:          defaultEnv("TS_SOCKET", "/tmp/tailscaled.sock"),
+		AuthOnce:        defaultBool("TS_AUTH_ONCE", false),
+		Root:            defaultEnv("TS_TEST_ONLY_ROOT", "/"),
+	}
+
+	if cfg.ProxyTo != "" && cfg.UserspaceMode {
+		log.Fatal("TS_DEST_IP is not supported with TS_USERSPACE")
+	}
+
+	if !cfg.UserspaceMode {
+		if err := ensureTunFile(cfg.Root); err != nil {
+			log.Fatalf("Unable to create tuntap device file: %v", err)
+		}
+		if cfg.ProxyTo != "" || cfg.Routes != "" {
+			if err := ensureIPForwarding(cfg.Root, cfg.ProxyTo, cfg.Routes); err != nil {
+				log.Printf("Failed to enable IP forwarding: %v", err)
+				log.Printf("To run tailscale as a proxy or router container, IP forwarding must be enabled.")
+				if cfg.InKubernetes {
+					log.Fatalf("You can either set the sysctls as a privileged initContainer, or run the tailscale container with privileged=true.")
+				} else {
+					log.Fatalf("You can fix this by running the container with privileged=true, or the equivalent in your container runtime that permits access to sysctls.")
+				}
+			}
+		}
+	}
+
+	if cfg.InKubernetes {
+		initKube(cfg.Root)
+	}
+
+	// Context is used for all setup stuff until we're in steady
+	// state, so that if something is hanging we eventually time out
+	// and crashloop the container.
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+
+	if cfg.InKubernetes && cfg.KubeSecret != "" {
+		canPatch, err := checkSecretPermissions(ctx, cfg.KubeSecret)
+		if err != nil {
+			log.Fatalf("Some Kubernetes permissions are missing, please check your RBAC configuration: %v", err)
+		}
+		cfg.KubernetesCanPatch = canPatch
+
+		if cfg.AuthKey == "" {
+			key, err := findKeyInKubeSecret(ctx, cfg.KubeSecret)
+			if err != nil {
+				log.Fatalf("Getting authkey from kube secret: %v", err)
+			}
+			if key != "" {
+				// This behavior of pulling authkeys from kube secrets was added
+				// at the same time as the patch permission, so we can enforce
+				// that we must be able to patch out the authkey after
+				// authenticating if you want to use this feature. This avoids
+				// us having to deal with the case where we might leave behind
+				// an unnecessary reusable authkey in a secret, like a rake in
+				// the grass.
+				if !cfg.KubernetesCanPatch {
+					log.Fatalf("authkey found in TS_KUBE_SECRET, but the pod doesn't have patch permissions on the secret to manage the authkey.")
+				}
+				log.Print("Using authkey found in kube secret")
+				cfg.AuthKey = key
+			} else {
+				log.Print("No authkey found in kube secret and TS_AUTHKEY not provided, login will be interactive if needed.")
+			}
+		}
+	}
+
+	client, daemonPid, err := startTailscaled(ctx, cfg)
+	if err != nil {
+		log.Fatalf("failed to bring up tailscale: %v", err)
+	}
+
+	w, err := client.WatchIPNBus(ctx, ipn.NotifyInitialNetMap|ipn.NotifyInitialPrefs|ipn.NotifyInitialState)
+	if err != nil {
+		log.Fatalf("failed to watch tailscaled for updates: %v", err)
+	}
+
+	// Because we're still shelling out to `tailscale up` to get access to its
+	// flag parser, we have to stop watching the IPN bus so that we can block on
+	// the subcommand without stalling anything. Then once it's done, we resume
+	// watching the bus.
+	//
+	// Depending on the requested mode of operation, this auth step happens at
+	// different points in containerboot's lifecycle, hence the helper function.
+	didLogin := false
+	authTailscale := func() error {
+		if didLogin {
+			return nil
+		}
+		didLogin = true
+		w.Close()
+		if err := tailscaleUp(ctx, cfg); err != nil {
+			return fmt.Errorf("failed to auth tailscale: %v", err)
+		}
+		w, err = client.WatchIPNBus(ctx, ipn.NotifyInitialNetMap|ipn.NotifyInitialState)
+		if err != nil {
+			return fmt.Errorf("rewatching tailscaled for updates after auth: %v", err)
+		}
+		return nil
+	}
+
+	if !cfg.AuthOnce {
+		if err := authTailscale(); err != nil {
+			log.Fatalf("failed to auth tailscale: %v", err)
+		}
+	}
+
+authLoop:
+	for {
+		n, err := w.Next()
+		if err != nil {
+			log.Fatalf("failed to read from tailscaled: %v", err)
+		}
+
+		if n.State != nil {
+			switch *n.State {
+			case ipn.NeedsLogin:
+				if err := authTailscale(); err != nil {
+					log.Fatalf("failed to auth tailscale: %v", err)
+				}
+			case ipn.NeedsMachineAuth:
+				log.Printf("machine authorization required, please visit the admin panel")
+			case ipn.Running:
+				// Technically, all we want is to keep monitoring the bus for
+				// netmap updates. However, in order to make the container crash
+				// if tailscale doesn't initially come up, the watch has a
+				// startup deadline on it. So, we have to break out of this
+				// watch loop, cancel the watch, and watch again with no
+				// deadline to continue monitoring for changes.
+				break authLoop
+			default:
+				log.Printf("tailscaled in state %q, waiting", *n.State)
+			}
+		}
+	}
+
+	w.Close()
+
+	if cfg.InKubernetes && cfg.KubeSecret != "" && cfg.KubernetesCanPatch && cfg.AuthOnce {
+		// We were told to only auth once, so any secret-bound
+		// authkey is no longer needed. We don't strictly need to
+		// wipe it, but it's good hygiene.
+		log.Printf("Deleting authkey from kube secret")
+		if err := deleteAuthKey(ctx, cfg.KubeSecret); err != nil {
+			log.Fatalf("deleting authkey from kube secret: %v", err)
+		}
+	}
+
+	w, err = client.WatchIPNBus(context.Background(), ipn.NotifyInitialNetMap|ipn.NotifyInitialState)
+	if err != nil {
+		log.Fatalf("rewatching tailscaled for updates after auth: %v", err)
+	}
+
+	var (
+		wantProxy         = cfg.ProxyTo != ""
+		wantDeviceInfo    = cfg.InKubernetes && cfg.KubeSecret != "" && cfg.KubernetesCanPatch
+		startupTasksDone  = false
+		currentIPs        deephash.Sum // tailscale IPs assigned to device
+		currentDeviceInfo deephash.Sum // device ID and fqdn
+	)
+	for {
+		n, err := w.Next()
+		if err != nil {
+			log.Fatalf("failed to read from tailscaled: %v", err)
+		}
+
+		if n.State != nil && *n.State != ipn.Running {
+			// Something's gone wrong and we've left the authenticated state.
+			// Our container image never recovered gracefully from this, and the
+			// control flow required to make it work now is hard. So, just crash
+			// the container and rely on the container runtime to restart us,
+			// whereupon we'll go through initial auth again.
+			log.Fatalf("tailscaled left running state (now in state %q), exiting", *n.State)
+		}
+		if n.NetMap != nil {
+			if cfg.ProxyTo != "" && len(n.NetMap.Addresses) > 0 && deephash.Update(&currentIPs, &n.NetMap.Addresses) {
+				if err := installIPTablesRule(ctx, cfg.ProxyTo, n.NetMap.Addresses); err != nil {
+					log.Fatalf("installing proxy rules: %v", err)
+				}
+			}
+			deviceInfo := []any{n.NetMap.SelfNode.StableID, n.NetMap.SelfNode.Name}
+			if cfg.InKubernetes && cfg.KubernetesCanPatch && cfg.KubeSecret != "" && deephash.Update(&currentDeviceInfo, &deviceInfo) {
+				if err := storeDeviceInfo(ctx, cfg.KubeSecret, n.NetMap.SelfNode.StableID, n.NetMap.SelfNode.Name); err != nil {
+					log.Fatalf("storing device ID in kube secret: %v", err)
+				}
+			}
+		}
+		if !startupTasksDone {
+			if (!wantProxy || currentIPs != deephash.Sum{}) && (!wantDeviceInfo || currentDeviceInfo != deephash.Sum{}) {
+				// This log message is used in tests to detect when all
+				// post-auth configuration is done.
+				log.Println("Startup complete, waiting for shutdown signal")
+				startupTasksDone = true
+
+				// Reap all processes, since we are PID1 and need to collect zombies. We can
+				// only start doing this once we've stopped shelling out to things
+				// `tailscale up`, otherwise this goroutine can reap the CLI subprocesses
+				// and wedge bringup.
+				go func() {
+					for {
+						var status unix.WaitStatus
+						pid, err := unix.Wait4(-1, &status, 0, nil)
+						if errors.Is(err, unix.EINTR) {
+							continue
+						}
+						if err != nil {
+							log.Fatalf("Waiting for exited processes: %v", err)
+						}
+						if pid == daemonPid {
+							log.Printf("Tailscaled exited")
+							os.Exit(0)
+						}
+					}
+				}()
+			}
+		}
+	}
+}
+
+func startTailscaled(ctx context.Context, cfg *settings) (*tailscale.LocalClient, int, error) {
+	args := tailscaledArgs(cfg)
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, unix.SIGTERM, unix.SIGINT)
+	// tailscaled runs without context, since it needs to persist
+	// beyond the startup timeout in ctx.
+	cmd := exec.Command("tailscaled", args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Setpgid: true,
+	}
+	log.Printf("Starting tailscaled")
+	if err := cmd.Start(); err != nil {
+		return nil, 0, fmt.Errorf("starting tailscaled failed: %v", err)
+	}
+	go func() {
+		<-sigCh
+		log.Printf("Received SIGTERM from container runtime, shutting down tailscaled")
+		cmd.Process.Signal(unix.SIGTERM)
+	}()
+
+	// Wait for the socket file to appear, otherwise API ops will racily fail.
+	log.Printf("Waiting for tailscaled socket")
+	for {
+		if ctx.Err() != nil {
+			log.Fatalf("Timed out waiting for tailscaled socket")
+		}
+		_, err := os.Stat(cfg.Socket)
+		if errors.Is(err, fs.ErrNotExist) {
+			time.Sleep(100 * time.Millisecond)
+			continue
+		} else if err != nil {
+			log.Fatalf("Waiting for tailscaled socket: %v", err)
+		}
+		break
+	}
+
+	tsClient := &tailscale.LocalClient{
+		Socket:        cfg.Socket,
+		UseSocketOnly: true,
+	}
+
+	return tsClient, cmd.Process.Pid, nil
+}
+
+// tailscaledArgs uses cfg to construct the argv for tailscaled.
+func tailscaledArgs(cfg *settings) []string {
+	args := []string{"--socket=" + cfg.Socket}
+	switch {
+	case cfg.InKubernetes && cfg.KubeSecret != "":
+		args = append(args, "--state=kube:"+cfg.KubeSecret)
+		if cfg.StateDir == "" {
+			cfg.StateDir = "/tmp"
+		}
+		fallthrough
+	case cfg.StateDir != "":
+		args = append(args, "--statedir="+cfg.StateDir)
+	default:
+		args = append(args, "--state=mem:", "--statedir=/tmp")
+	}
+
+	if cfg.UserspaceMode {
+		args = append(args, "--tun=userspace-networking")
+	} else if err := ensureTunFile(cfg.Root); err != nil {
+		log.Fatalf("ensuring that /dev/net/tun exists: %v", err)
+	}
+
+	if cfg.SOCKSProxyAddr != "" {
+		args = append(args, "--socks5-server="+cfg.SOCKSProxyAddr)
+	}
+	if cfg.HTTPProxyAddr != "" {
+		args = append(args, "--outbound-http-proxy-listen="+cfg.HTTPProxyAddr)
+	}
+	if cfg.DaemonExtraArgs != "" {
+		args = append(args, strings.Fields(cfg.DaemonExtraArgs)...)
+	}
+	return args
+}
+
+// tailscaleUp uses cfg to run 'tailscale up'.
+func tailscaleUp(ctx context.Context, cfg *settings) error {
+	args := []string{"--socket=" + cfg.Socket, "up"}
+	if cfg.AcceptDNS {
+		args = append(args, "--accept-dns=true")
+	} else {
+		args = append(args, "--accept-dns=false")
+	}
+	if cfg.AuthKey != "" {
+		args = append(args, "--authkey="+cfg.AuthKey)
+	}
+	if cfg.Routes != "" {
+		args = append(args, "--advertise-routes="+cfg.Routes)
+	}
+	if cfg.Hostname != "" {
+		args = append(args, "--hostname="+cfg.Hostname)
+	}
+	if cfg.ExtraArgs != "" {
+		args = append(args, strings.Fields(cfg.ExtraArgs)...)
+	}
+	log.Printf("Running 'tailscale up'")
+	cmd := exec.CommandContext(ctx, "tailscale", args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("tailscale up failed: %v", err)
+	}
+	return nil
+}
+
+// ensureTunFile checks that /dev/net/tun exists, creating it if
+// missing.
+func ensureTunFile(root string) error {
+	// Verify that /dev/net/tun exists, in some container envs it
+	// needs to be mknod-ed.
+	if _, err := os.Stat(filepath.Join(root, "dev/net")); errors.Is(err, fs.ErrNotExist) {
+		if err := os.MkdirAll(filepath.Join(root, "dev/net"), 0755); err != nil {
+			return err
+		}
+	}
+	if _, err := os.Stat(filepath.Join(root, "dev/net/tun")); errors.Is(err, fs.ErrNotExist) {
+		dev := unix.Mkdev(10, 200) // tuntap major and minor
+		if err := unix.Mknod(filepath.Join(root, "dev/net/tun"), 0600|unix.S_IFCHR, int(dev)); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ensureIPForwarding enables IPv4/IPv6 forwarding for the container.
+func ensureIPForwarding(root, proxyTo, routes string) error {
+	var (
+		v4Forwarding, v6Forwarding bool
+	)
+	if proxyTo != "" {
+		proxyIP, err := netip.ParseAddr(proxyTo)
+		if err != nil {
+			return fmt.Errorf("invalid proxy destination IP: %v", err)
+		}
+		if proxyIP.Is4() {
+			v4Forwarding = true
+		} else {
+			v6Forwarding = true
+		}
+	}
+	if routes != "" {
+		for _, route := range strings.Split(routes, ",") {
+			cidr, err := netip.ParsePrefix(route)
+			if err != nil {
+				return fmt.Errorf("invalid subnet route: %v", err)
+			}
+			if cidr.Addr().Is4() {
+				v4Forwarding = true
+			} else {
+				v6Forwarding = true
+			}
+		}
+	}
+
+	var paths []string
+	if v4Forwarding {
+		paths = append(paths, filepath.Join(root, "proc/sys/net/ipv4/ip_forward"))
+	}
+	if v6Forwarding {
+		paths = append(paths, filepath.Join(root, "proc/sys/net/ipv6/conf/all/forwarding"))
+	}
+
+	// In some common configurations (e.g. default docker,
+	// kubernetes), the container environment denies write access to
+	// most sysctls, including IP forwarding controls. Check the
+	// sysctl values before trying to change them, so that we
+	// gracefully do nothing if the container's already been set up
+	// properly by e.g. a k8s initContainer.
+	for _, path := range paths {
+		bs, err := os.ReadFile(path)
+		if err != nil {
+			return fmt.Errorf("reading %q: %w", path, err)
+		}
+		if v := strings.TrimSpace(string(bs)); v != "1" {
+			if err := os.WriteFile(path, []byte("1"), 0644); err != nil {
+				return fmt.Errorf("enabling %q: %w", path, err)
+			}
+		}
+	}
+	return nil
+}
+
+func installIPTablesRule(ctx context.Context, dstStr string, tsIPs []netip.Prefix) error {
+	dst, err := netip.ParseAddr(dstStr)
+	if err != nil {
+		return err
+	}
+	argv0 := "iptables"
+	if dst.Is6() {
+		argv0 = "ip6tables"
+	}
+	var local string
+	for _, pfx := range tsIPs {
+		if !pfx.IsSingleIP() {
+			continue
+		}
+		if pfx.Addr().Is4() != dst.Is4() {
+			continue
+		}
+		local = pfx.Addr().String()
+		break
+	}
+	if local == "" {
+		return fmt.Errorf("no tailscale IP matching family of %s found in %v", dstStr, tsIPs)
+	}
+	// Technically, if the control server ever changes the IPs assigned to this
+	// node, we'll slowly accumulate iptables rules. This shouldn't happen, so
+	// for now we'll live with it.
+	cmd := exec.CommandContext(ctx, argv0, "-t", "nat", "-I", "PREROUTING", "1", "-d", local, "-j", "DNAT", "--to-destination", dstStr)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("executing iptables failed: %w", err)
+	}
+	return nil
+}
+
+// settings is all the configuration for containerboot.
+type settings struct {
+	AuthKey            string
+	Hostname           string
+	Routes             string
+	ProxyTo            string
+	DaemonExtraArgs    string
+	ExtraArgs          string
+	InKubernetes       bool
+	UserspaceMode      bool
+	StateDir           string
+	AcceptDNS          bool
+	KubeSecret         string
+	SOCKSProxyAddr     string
+	HTTPProxyAddr      string
+	Socket             string
+	AuthOnce           bool
+	Root               string
+	KubernetesCanPatch bool
+}
+
+// defaultEnv returns the value of the given envvar name, or defVal if
+// unset.
+func defaultEnv(name, defVal string) string {
+	if v, ok := os.LookupEnv(name); ok {
+		return v
+	}
+	return defVal
+}
+
+func defaultEnvs(names []string, defVal string) string {
+	for _, name := range names {
+		if v, ok := os.LookupEnv(name); ok {
+			return v
+		}
+	}
+	return defVal
+}
+
+// defaultBool returns the boolean value of the given envvar name, or
+// defVal if unset or not a bool.
+func defaultBool(name string, defVal bool) bool {
+	v := os.Getenv(name)
+	ret, err := strconv.ParseBool(v)
+	if err != nil {
+		return defVal
+	}
+	return ret
+}

cmd/containerboot/test_tailscale.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+#
+# This is a fake tailscale CLI (and also iptables and ip6tables) that
+# records its arguments and exits successfully.
+#
+# It is used by main_test.go to test the behavior of containerboot.
+
+echo $0 $@ >>$TS_TEST_RECORD_ARGS

cmd/containerboot/test_tailscaled.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+#
+# This is a fake tailscale CLI that records its arguments, symlinks a
+# fake LocalAPI socket into place, and does nothing until terminated.
+#
+# It is used by main_test.go to test the behavior of containerboot.
+
+set -eu
+
+echo $0 $@ >>$TS_TEST_RECORD_ARGS
+
+socket=""
+while [[ $# -gt 0 ]]; do
+	case $1 in
+		--socket=*)
+			socket="${1#--socket=}"
+			shift
+			;;
+		--socket)
+			shift
+			socket="$1"
+			shift
+			;;
+		*)
+			shift
+			;;
+	esac
+done
+
+if [[ -z "$socket" ]]; then
+	echo "didn't find socket path in args"
+	exit 1
+fi
+
+ln -s "$TS_TEST_SOCKET" "$socket"
+
+while true; do sleep 1; done

cmd/derper/bootstrap_dns.go

@@ -1,6 +1,5 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 package main
 
@@ -12,23 +11,36 @@ 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 +49,34 @@ 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 +84,49 @@ 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 +1,153 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+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 +1,105 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+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 +1,213 @@
+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/Microsoft/go-winio                                from tailscale.com/safesocket
+   W 💣 github.com/Microsoft/go-winio/internal/socket                from github.com/Microsoft/go-winio
+   W    github.com/Microsoft/go-winio/pkg/guid                       from github.com/Microsoft/go-winio+
+   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/health                                         from tailscale.com/net/tlsdial
+        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/net/wsconn                                     from tailscale.com/cmd/derper+
+        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/persist                                  from tailscale.com/ipn
+        tailscale.com/types/preftype                                 from tailscale.com/ipn
+        tailscale.com/types/ptr                                      from tailscale.com/hostinfo+
+        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+
+   W    tailscale.com/util/clientmetric                              from tailscale.com/net/tshttpproxy
+        tailscale.com/util/cloudenv                                  from tailscale.com/hostinfo+
+   W    tailscale.com/util/cmpver                                    from tailscale.com/net/tshttpproxy
+   L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
+        tailscale.com/util/dnsname                                   from tailscale.com/hostinfo+
+        tailscale.com/util/httpm                                     from tailscale.com/client/tailscale
+        tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
+        tailscale.com/util/mak                                       from tailscale.com/syncs
+        tailscale.com/util/multierr                                  from tailscale.com/health
+        tailscale.com/util/set                                       from tailscale.com/health
+        tailscale.com/util/singleflight                              from tailscale.com/net/dnscache
+        tailscale.com/util/vizerror                                  from tailscale.com/tsweb
+   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 golang.org/x/crypto/nacl/box+
+        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+
+        golang.org/x/exp/constraints                                 from golang.org/x/exp/slices
+        golang.org/x/exp/slices                                      from tailscale.com/net/tsaddr+
+   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+
+   W    golang.org/x/sys/windows/svc                                 from golang.org/x/sys/windows/svc/mgr+
+   W    golang.org/x/sys/windows/svc/mgr                             from tailscale.com/util/winutil
+        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/ecdh                                                  from crypto/ecdsa+
+        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+
+   W    os/user                                                      from tailscale.com/util/winutil
+        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

@@ -1,6 +1,5 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 // The derper binary is a simple DERP server.
 package main // import "tailscale.com/cmd/derper"
@@ -13,56 +12,92 @@ import (
 	"expvar"
 	"flag"
 	"fmt"
-	"html"
 	"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"
-	"tailscale.com/version"
 )
 
 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")
+	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 == "" {
-		log.Fatalf("derper: -c <config path> not specified")
+		if os.Getuid() == 0 {
+			*configPath = "/var/lib/derper/derper.key"
+		} else {
+			log.Fatalf("derper: -c <config path> not specified")
+		}
+		log.Printf("no config path specified; using %s", *configPath)
 	}
-	b, err := ioutil.ReadFile(*configPath)
+	b, err := os.ReadFile(*configPath)
 	switch {
 	case errors.Is(err, os.ErrNotExist):
 		return writeNewConfig()
@@ -78,21 +113,13 @@ 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 {
@@ -108,26 +135,25 @@ 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 != "" {
-		b, err := ioutil.ReadFile(*meshPSKFile)
+		b, err := os.ReadFile(*meshPSKFile)
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -143,9 +169,17 @@ func main() {
 	}
 	expvar.Publish("derp", s.ExpVar())
 
-	// Create our own mux so we don't expose /debug/ stuff to the world.
-	mux := tsweb.NewMux(debugHandler(s))
-	mux.Handle("/derp", derphttp.Handler(s))
+	mux := http.NewServeMux()
+	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) {
@@ -160,54 +194,127 @@ 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")
+	}))
+	mux.Handle("/generate_204", http.HandlerFunc(serveNoContent))
+	debug := tsweb.Debugger(mux)
+	debug.KV("TLS hostname", *hostname)
+	debug.KV("Mesh key", s.HasMeshKey())
+	debug.Handle("check", "Consistency check", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		err := s.ConsistencyCheck()
+		if err != nil {
+			http.Error(w, err.Error(), 500)
+		} else {
+			io.WriteString(w, "derp.Server ConsistencyCheck okay")
+		}
+	}))
+	debug.Handle("traffic", "Traffic check", http.HandlerFunc(s.ServeDebugTraffic))
 
 	if *runSTUN {
-		go serveSTUN()
+		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() {
+				port80mux := http.NewServeMux()
+				port80mux.HandleFunc("/generate_204", serveNoContent)
+				port80mux.Handle("/", certManager.HTTPHandler(tsweb.Port80Handler{Main: mux}))
+				port80srv := &http.Server{
+					Addr:        net.JoinHostPort(listenHost, fmt.Sprintf("%d", *httpPort)),
+					Handler:     port80mux,
+					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()
@@ -217,78 +324,69 @@ func main() {
 	}
 }
 
-func debugHandler(s *derp.Server) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.RequestURI == "/debug/check" {
-			err := s.ConsistencyCheck()
-			if err != nil {
-				http.Error(w, err.Error(), 500)
-			} else {
-				io.WriteString(w, "derp.Server ConsistencyCheck okay")
-			}
-			return
-		}
-		f := func(format string, args ...interface{}) { fmt.Fprintf(w, format, args...) }
-		f(`<html><body>
-<h1>DERP debug</h1>
-<ul>
-`)
-		f("<li><b>Hostname:</b> %v</li>\n", html.EscapeString(*hostname))
-		f("<li><b>Uptime:</b> %v</li>\n", tsweb.Uptime())
-		f("<li><b>Mesh Key:</b> %v</li>\n", s.HasMeshKey())
-		f("<li><b>Version:</b> %v</li>\n", html.EscapeString(version.Long))
+const (
+	noContentChallengeHeader = "X-Tailscale-Challenge"
+	noContentResponseHeader  = "X-Tailscale-Response"
+)
 
-		f(`<li><a href="/debug/vars">/debug/vars</a> (Go)</li>
-   <li><a href="/debug/varz">/debug/varz</a> (Prometheus)</li>
-   <li><a href="/debug/pprof/">/debug/pprof/</a></li>
-   <li><a href="/debug/pprof/goroutine?debug=1">/debug/pprof/goroutine</a> (collapsed)</li>
-   <li><a href="/debug/pprof/goroutine?debug=2">/debug/pprof/goroutine</a> (full)</li>
-   <li><a href="/debug/check">/debug/check</a> internal consistency check</li>
-<ul>
-</html>
-`)
-	})
+// For captive portal detection
+func serveNoContent(w http.ResponseWriter, r *http.Request) {
+	if challenge := r.Header.Get(noContentChallengeHeader); challenge != "" {
+		badChar := strings.IndexFunc(challenge, func(r rune) bool {
+			return !isChallengeChar(r)
+		}) != -1
+		if len(challenge) <= 64 && !badChar {
+			w.Header().Set(noContentResponseHeader, "response "+challenge)
+		}
+	}
+	w.WriteHeader(http.StatusNoContent)
 }
 
-func serveSTUN() {
-	pc, err := net.ListenPacket("udp", ":3478")
+func isChallengeChar(c rune) bool {
+	// Semi-randomly chosen as a limited set of valid characters
+	return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') ||
+		('0' <= c && c <= '9') ||
+		c == '.' || c == '-' || c == '_'
+}
+
+// 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)
@@ -304,8 +402,9 @@ 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 {
@@ -335,3 +434,82 @@ 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

@@ -1,12 +1,17 @@
-// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 package main
 
 import (
 	"context"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strings"
 	"testing"
+
+	"tailscale.com/net/stun"
 )
 
 func TestProdAutocertHostPolicy(t *testing.T) {
@@ -31,5 +36,95 @@ 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)
+		}
+	}
 
 }
+
+func TestNoContent(t *testing.T) {
+	testCases := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{
+			name: "no challenge",
+		},
+		{
+			name:  "valid challenge",
+			input: "input",
+			want:  "response input",
+		},
+		{
+			name:  "valid challenge hostname",
+			input: "ts_derp99b.tailscale.com",
+			want:  "response ts_derp99b.tailscale.com",
+		},
+		{
+			name:  "invalid challenge",
+			input: "foo\x00bar",
+			want:  "",
+		},
+		{
+			name:  "whitespace invalid challenge",
+			input: "foo bar",
+			want:  "",
+		},
+		{
+			name:  "long challenge",
+			input: strings.Repeat("x", 65),
+			want:  "",
+		},
+	}
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			req, _ := http.NewRequest("GET", "https://localhost/generate_204", nil)
+			if tt.input != "" {
+				req.Header.Set(noContentChallengeHeader, tt.input)
+			}
+			w := httptest.NewRecorder()
+			serveNoContent(w, req)
+			resp := w.Result()
+
+			if tt.want == "" {
+				if h, found := resp.Header[noContentResponseHeader]; found {
+					t.Errorf("got %+v; expected no response header", h)
+				}
+				return
+			}
+
+			if got := resp.Header.Get(noContentResponseHeader); got != tt.want {
+				t.Errorf("got %q; want %q", got, tt.want)
+			}
+		})
+	}
+}

cmd/derper/mesh.go

@@ -1,6 +1,5 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 package main
 
@@ -9,7 +8,9 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"net"
 	"strings"
+	"time"
 
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
@@ -39,8 +40,35 @@ func startMeshWithHost(s *derp.Server, host string) error {
 		return err
 	}
 	c.MeshKey = s.MeshKey()
-	add := func(k key.Public) { s.AddPacketForwarder(k, c) }
-	remove := func(k key.Public) { s.RemovePacketForwarder(k, c) }
+
+	// For meshed peers within a region, connect via VPC addresses.
+	c.SetURLDialer(func(ctx context.Context, network, addr string) (net.Conn, error) {
+		host, port, err := net.SplitHostPort(addr)
+		if err != nil {
+			return nil, err
+		}
+		var d net.Dialer
+		var r net.Resolver
+		if base, ok := strings.CutSuffix(host, ".tailscale.com"); ok && port == "443" {
+			subCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
+			defer cancel()
+			vpcHost := base + "-vpc.tailscale.com"
+			ips, _ := r.LookupIP(subCtx, "ip", vpcHost)
+			if len(ips) > 0 {
+				vpcAddr := net.JoinHostPort(ips[0].String(), port)
+				c, err := d.DialContext(subCtx, network, vpcAddr)
+				if err == nil {
+					log.Printf("connected to %v (%v) instead of %v", vpcHost, ips[0], base)
+					return c, nil
+				}
+				log.Printf("failed to connect to %v (%v): %v; trying non-VPC route", vpcHost, ips[0], err)
+			}
+		}
+		return d.DialContext(ctx, network, addr)
+	})
+
+	add := func(k key.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 +1,57 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"bufio"
+	"expvar"
+	"log"
+	"net/http"
+	"strings"
+
+	"nhooyr.io/websocket"
+	"tailscale.com/derp"
+	"tailscale.com/net/wsconn"
+)
+
+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 framing). 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{"*"},
+			// Disable compression because we transmit WireGuard messages that
+			// are not compressible.
+			// Additionally, Safari has a broken implementation of compression
+			// (see https://github.com/nhooyr/websocket/issues/218) that makes
+			// enabling it actively harmful.
+			CompressionMode: websocket.CompressionDisabled,
+		})
+		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 := wsconn.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

@@ -0,0 +1,111 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// The derpprobe binary probes derpers.
+package main
+
+import (
+	"expvar"
+	"flag"
+	"fmt"
+	"html"
+	"io"
+	"log"
+	"net/http"
+	"sort"
+	"time"
+
+	"tailscale.com/prober"
+	"tailscale.com/tsweb"
+)
+
+var (
+	derpMapURL = flag.String("derp-map", "https://login.tailscale.com/derpmap/default", "URL to DERP map (https:// or file://)")
+	listen     = flag.String("listen", ":8030", "HTTP listen address")
+	probeOnce  = flag.Bool("once", false, "probe once and print results, then exit; ignores the listen flag")
+	interval   = flag.Duration("interval", 15*time.Second, "probe interval")
+)
+
+func main() {
+	flag.Parse()
+
+	p := prober.New().WithSpread(true).WithOnce(*probeOnce)
+	dp, err := prober.DERP(p, *derpMapURL, *interval, *interval, *interval)
+	if err != nil {
+		log.Fatal(err)
+	}
+	p.Run("derpmap-probe", *interval, nil, dp.ProbeMap)
+
+	if *probeOnce {
+		log.Printf("Waiting for all probes (may take up to 1m)")
+		p.Wait()
+
+		st := getOverallStatus(p)
+		for _, s := range st.good {
+			log.Printf("good: %s", s)
+		}
+		for _, s := range st.bad {
+			log.Printf("bad: %s", s)
+		}
+		return
+	}
+
+	mux := http.NewServeMux()
+	tsweb.Debugger(mux)
+	expvar.Publish("derpprobe", p.Expvar())
+	mux.HandleFunc("/", http.HandlerFunc(serveFunc(p)))
+	log.Fatal(http.ListenAndServe(*listen, mux))
+}
+
+type overallStatus struct {
+	good, bad []string
+}
+
+func (st *overallStatus) addBadf(format string, a ...any) {
+	st.bad = append(st.bad, fmt.Sprintf(format, a...))
+}
+
+func (st *overallStatus) addGoodf(format string, a ...any) {
+	st.good = append(st.good, fmt.Sprintf(format, a...))
+}
+
+func getOverallStatus(p *prober.Prober) (o overallStatus) {
+	for p, i := range p.ProbeInfo() {
+		if i.End.IsZero() {
+			// Do not show probes that have not finished yet.
+			continue
+		}
+		if i.Result {
+			o.addGoodf("%s: %s", p, i.Latency)
+		} else {
+			o.addBadf("%s: %s", p, i.Error)
+		}
+	}
+
+	sort.Strings(o.bad)
+	sort.Strings(o.good)
+	return
+}
+
+func serveFunc(p *prober.Prober) func(w http.ResponseWriter, r *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		st := getOverallStatus(p)
+		summary := "All good"
+		if (float64(len(st.bad)) / float64(len(st.bad)+len(st.good))) > 0.25 {
+			// Returning a 500 allows monitoring this server externally and configuring
+			// an alert on HTTP response code.
+			w.WriteHeader(500)
+			summary = fmt.Sprintf("%d problems", len(st.bad))
+		}
+
+		io.WriteString(w, "<html><head><style>.bad { font-weight: bold; color: #700; }</style></head>\n")
+		fmt.Fprintf(w, "<body><h1>derp probe</h1>\n%s:<ul>", summary)
+		for _, s := range st.bad {
+			fmt.Fprintf(w, "<li class=bad>%s</li>\n", html.EscapeString(s))
+		}
+		for _, s := range st.good {
+			fmt.Fprintf(w, "<li>%s</li>\n", html.EscapeString(s))
+		}
+		io.WriteString(w, "</ul></body></html>\n")
+	}
+}

cmd/get-authkey/.gitignore

@@ -0,0 +1 @@
+get-authkey

cmd/get-authkey/main.go

@@ -0,0 +1,72 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// get-authkey allocates an authkey using an OAuth API client
+// https://tailscale.com/kb/1215/oauth-clients/ and prints it
+// to stdout for scripts to capture and use.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	"golang.org/x/oauth2/clientcredentials"
+	"tailscale.com/client/tailscale"
+)
+
+func main() {
+	// Required to use our client API. We're fine with the instability since the
+	// client lives in the same repo as this code.
+	tailscale.I_Acknowledge_This_API_Is_Unstable = true
+
+	reusable := flag.Bool("reusable", false, "allocate a reusable authkey")
+	ephemeral := flag.Bool("ephemeral", false, "allocate an ephemeral authkey")
+	preauth := flag.Bool("preauth", true, "set the authkey as pre-authorized")
+	tags := flag.String("tags", "", "comma-separated list of tags to apply to the authkey")
+	flag.Parse()
+
+	clientId := os.Getenv("TS_API_CLIENT_ID")
+	clientSecret := os.Getenv("TS_API_CLIENT_SECRET")
+	if clientId == "" || clientSecret == "" {
+		log.Fatal("TS_API_CLIENT_ID and TS_API_CLIENT_SECRET must be set")
+	}
+
+	baseUrl := os.Getenv("TS_BASE_URL")
+	if baseUrl == "" {
+		baseUrl = "https://api.tailscale.com"
+	}
+
+	credentials := clientcredentials.Config{
+		ClientID:     clientId,
+		ClientSecret: clientSecret,
+		TokenURL:     baseUrl + "/api/v2/oauth/token",
+		Scopes:       []string{"device"},
+	}
+
+	ctx := context.Background()
+	tsClient := tailscale.NewClient("-", nil)
+	tsClient.HTTPClient = credentials.Client(ctx)
+	tsClient.BaseURL = baseUrl
+
+	caps := tailscale.KeyCapabilities{
+		Devices: tailscale.KeyDeviceCapabilities{
+			Create: tailscale.KeyDeviceCreateCapabilities{
+				Reusable:      *reusable,
+				Ephemeral:     *ephemeral,
+				Preauthorized: *preauth,
+				Tags:          strings.Split(*tags, ","),
+			},
+		},
+	}
+
+	authkey, _, err := tsClient.CreateKey(ctx, caps)
+	if err != nil {
+		log.Fatal(err.Error())
+	}
+
+	fmt.Println(authkey)
+}

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 +1,66 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+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 +1,371 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// 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"
+	"tailscale.com/util/httpm"
+)
+
+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)")
+	apiServer    = rootFlagSet.String("api-server", "api.tailscale.com", "API server to contact")
+)
+
+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, httpm.POST, fmt.Sprintf("https://%s/api/v2/tailnet/%s/acl", *apiServer, 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, httpm.POST, fmt.Sprintf("https://%s/api/v2/tailnet/%s/acl/validate", *apiServer, 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, httpm.GET, fmt.Sprintf("https://%s/api/v2/tailnet/%s/acl", *apiServer, 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

@@ -1,24 +1,25 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
-// 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"
 	"log"
 	"net/http"
 	"os"
 	"strings"
+	"time"
 
 	"tailscale.com/client/tailscale"
-	"tailscale.com/tailcfg"
+	"tailscale.com/client/tailscale/apitype"
 )
 
 var (
@@ -69,11 +70,31 @@ 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)
@@ -83,7 +104,7 @@ func devMode() bool { return *httpsAddr == "" && *httpAddr != "" }
 
 func getTmpl() (*template.Template, error) {
 	if devMode() {
-		tmplData, err := ioutil.ReadFile("hello.tmpl.html")
+		tmplData, err := os.ReadFile("hello.tmpl.html")
 		if os.IsNotExist(err) {
 			log.Printf("using baked-in template in dev mode; can't find hello.tmpl.html in current directory")
 			return tmpl, nil
@@ -107,18 +128,18 @@ type tmplData struct {
 	IP            string // "100.2.3.4"
 }
 
-func tailscaleIP(who *tailcfg.WhoIsResponse) string {
+func tailscaleIP(who *apitype.WhoIsResponse) string {
 	if who == nil {
 		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 +148,9 @@ func tailscaleIP(who *tailcfg.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 +159,10 @@ 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 +194,7 @@ 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 +204,6 @@ 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/k8s-operator/manifests/operator.yaml

@@ -0,0 +1,154 @@
+# Copyright (c) Tailscale Inc & AUTHORS
+# SPDX-License-Identifier: BSD-3-Clause
+
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: tailscale
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: proxies
+  namespace: tailscale
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: proxies
+  namespace: tailscale
+rules:
+- apiGroups: [""]
+  resources: ["secrets"]
+  verbs: ["*"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: proxies
+  namespace: tailscale
+subjects:
+- kind: ServiceAccount
+  name: proxies
+  namespace: tailscale
+roleRef:
+  kind: Role
+  name: proxies
+  apiGroup: rbac.authorization.k8s.io
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: operator
+  namespace: tailscale
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: tailscale-operator
+rules:
+- apiGroups: [""]
+  resources: ["services", "services/status"]
+  verbs: ["*"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: tailscale-operator
+subjects:
+- kind: ServiceAccount
+  name: operator
+  namespace: tailscale
+roleRef:
+  kind: ClusterRole
+  name: tailscale-operator
+  apiGroup: rbac.authorization.k8s.io
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: operator
+  namespace: tailscale
+rules:
+- apiGroups: [""]
+  resources: ["secrets"]
+  verbs: ["*"]
+- apiGroups: ["apps"]
+  resources: ["statefulsets"]
+  verbs: ["*"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: operator
+  namespace: tailscale
+subjects:
+- kind: ServiceAccount
+  name: operator
+  namespace: tailscale
+roleRef:
+  kind: Role
+  name: operator
+  apiGroup: rbac.authorization.k8s.io
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: operator-oauth
+  namespace: tailscale
+stringData:
+  client_id: # SET CLIENT ID HERE
+  client_secret: # SET CLIENT SECRET HERE
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: operator
+  namespace: tailscale
+spec:
+  replicas: 1
+  strategy:
+    type: Recreate
+  selector:
+    matchLabels:
+      app: operator
+  template:
+    metadata:
+      labels:
+        app: operator
+    spec:
+      serviceAccountName: operator
+      volumes:
+      - name: oauth
+        secret:
+          secretName: operator-oauth
+      containers:
+        - name: operator
+          image: tailscale/k8s-operator:unstable
+          resources:
+            requests:
+              cpu: 500m
+              memory: 100Mi
+          env:
+            - name: OPERATOR_HOSTNAME
+              value: tailscale-operator
+            - name: OPERATOR_SECRET
+              value: operator
+            - name: OPERATOR_LOGGING
+              value: info
+            - name: OPERATOR_NAMESPACE
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.namespace
+            - name: CLIENT_ID_FILE
+              value: /oauth/client_id
+            - name: CLIENT_SECRET_FILE
+              value: /oauth/client_secret
+            - name: PROXY_IMAGE
+              value: tailscale/tailscale:unstable
+            - name: PROXY_TAGS
+              value: tag:k8s
+          volumeMounts:
+          - name: oauth
+            mountPath: /oauth
+            readOnly: true

cmd/k8s-operator/manifests/proxy.yaml

@@ -0,0 +1,37 @@
+# This file is not a complete manifest, it's a skeleton that the operator embeds
+# at build time and then uses to construct Tailscale proxy pods.
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+spec:
+  replicas: 1
+  template:
+    metadata:
+      deletionGracePeriodSeconds: 10
+    spec:
+      serviceAccountName: proxies
+      initContainers:
+        - name: sysctler
+          image: busybox
+          securityContext:
+            privileged: true
+          command: ["/bin/sh"]
+          args:
+            - -c
+            - sysctl -w net.ipv4.ip_forward=1 net.ipv6.conf.all.forwarding=1
+      resources:
+        requests:
+          cpu: 1m
+          memory: 1Mi
+      containers:
+        - name: tailscale
+          imagePullPolicy: Always
+          env:
+            - name: TS_USERSPACE
+              value: "false"
+            - name: TS_AUTH_ONCE
+              value: "true"
+          securityContext:
+            capabilities:
+              add:
+                - NET_ADMIN

cmd/k8s-operator/operator.go

@@ -0,0 +1,701 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// tailscale-operator provides a way to expose services running in a Kubernetes
+// cluster to your Tailnet.
+package main
+
+import (
+	"context"
+	_ "embed"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/go-logr/zapr"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"golang.org/x/exp/slices"
+	"golang.org/x/oauth2/clientcredentials"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/builder"
+	"sigs.k8s.io/controller-runtime/pkg/cache"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/config"
+	"sigs.k8s.io/controller-runtime/pkg/handler"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
+	kzap "sigs.k8s.io/controller-runtime/pkg/log/zap"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
+	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	"sigs.k8s.io/controller-runtime/pkg/source"
+	"sigs.k8s.io/yaml"
+	"tailscale.com/client/tailscale"
+	"tailscale.com/ipn"
+	"tailscale.com/ipn/store/kubestore"
+	"tailscale.com/tsnet"
+	"tailscale.com/types/logger"
+	"tailscale.com/util/dnsname"
+)
+
+func main() {
+	// Required to use our client API. We're fine with the instability since the
+	// client lives in the same repo as this code.
+	tailscale.I_Acknowledge_This_API_Is_Unstable = true
+
+	var (
+		hostname         = defaultEnv("OPERATOR_HOSTNAME", "tailscale-operator")
+		kubeSecret       = defaultEnv("OPERATOR_SECRET", "")
+		operatorTags     = defaultEnv("OPERATOR_INITIAL_TAGS", "tag:k8s-operator")
+		tsNamespace      = defaultEnv("OPERATOR_NAMESPACE", "")
+		tslogging        = defaultEnv("OPERATOR_LOGGING", "info")
+		clientIDPath     = defaultEnv("CLIENT_ID_FILE", "")
+		clientSecretPath = defaultEnv("CLIENT_SECRET_FILE", "")
+		image            = defaultEnv("PROXY_IMAGE", "tailscale/tailscale:latest")
+		tags             = defaultEnv("PROXY_TAGS", "tag:k8s")
+	)
+
+	var opts []kzap.Opts
+	switch tslogging {
+	case "info":
+		opts = append(opts, kzap.Level(zapcore.InfoLevel))
+	case "debug":
+		opts = append(opts, kzap.Level(zapcore.DebugLevel))
+	case "dev":
+		opts = append(opts, kzap.UseDevMode(true), kzap.Level(zapcore.DebugLevel))
+	}
+	zlog := kzap.NewRaw(opts...).Sugar()
+	logf.SetLogger(zapr.NewLogger(zlog.Desugar()))
+	startlog := zlog.Named("startup")
+
+	if clientIDPath == "" || clientSecretPath == "" {
+		startlog.Fatalf("CLIENT_ID_FILE and CLIENT_SECRET_FILE must be set")
+	}
+	clientID, err := os.ReadFile(clientIDPath)
+	if err != nil {
+		startlog.Fatalf("reading client ID %q: %v", clientIDPath, err)
+	}
+	clientSecret, err := os.ReadFile(clientSecretPath)
+	if err != nil {
+		startlog.Fatalf("reading client secret %q: %v", clientSecretPath, err)
+	}
+	credentials := clientcredentials.Config{
+		ClientID:     string(clientID),
+		ClientSecret: string(clientSecret),
+		TokenURL:     "https://login.tailscale.com/api/v2/oauth/token",
+	}
+	tsClient := tailscale.NewClient("-", nil)
+	tsClient.HTTPClient = credentials.Client(context.Background())
+	s := &tsnet.Server{
+		Hostname: hostname,
+		Logf:     zlog.Named("tailscaled").Debugf,
+	}
+	if kubeSecret != "" {
+		st, err := kubestore.New(logger.Discard, kubeSecret)
+		if err != nil {
+			startlog.Fatalf("creating kube store: %v", err)
+		}
+		s.Store = st
+	}
+	if err := s.Start(); err != nil {
+		startlog.Fatalf("starting tailscale server: %v", err)
+	}
+	defer s.Close()
+	lc, err := s.LocalClient()
+	if err != nil {
+		startlog.Fatalf("getting local client: %v", err)
+	}
+
+	ctx := context.Background()
+	loginDone := false
+	machineAuthShown := false
+waitOnline:
+	for {
+		startlog.Debugf("querying tailscaled status")
+		st, err := lc.StatusWithoutPeers(ctx)
+		if err != nil {
+			startlog.Fatalf("getting status: %v", err)
+		}
+		switch st.BackendState {
+		case "Running":
+			break waitOnline
+		case "NeedsLogin":
+			if loginDone {
+				break
+			}
+			caps := tailscale.KeyCapabilities{
+				Devices: tailscale.KeyDeviceCapabilities{
+					Create: tailscale.KeyDeviceCreateCapabilities{
+						Reusable:      false,
+						Preauthorized: true,
+						Tags:          strings.Split(operatorTags, ","),
+					},
+				},
+			}
+			authkey, _, err := tsClient.CreateKey(ctx, caps)
+			if err != nil {
+				startlog.Fatalf("creating operator authkey: %v", err)
+			}
+			if err := lc.Start(ctx, ipn.Options{
+				AuthKey: authkey,
+			}); err != nil {
+				startlog.Fatalf("starting tailscale: %v", err)
+			}
+			if err := lc.StartLoginInteractive(ctx); err != nil {
+				startlog.Fatalf("starting login: %v", err)
+			}
+			startlog.Debugf("requested login by authkey")
+			loginDone = true
+		case "NeedsMachineAuth":
+			if !machineAuthShown {
+				startlog.Infof("Machine authorization required, please visit the admin panel to authorize")
+				machineAuthShown = true
+			}
+		default:
+			startlog.Debugf("waiting for tailscale to start: %v", st.BackendState)
+		}
+		time.Sleep(time.Second)
+	}
+
+	// For secrets and statefulsets, we only get permission to touch the objects
+	// in the controller's own namespace. This cannot be expressed by
+	// .Watches(...) below, instead you have to add a per-type field selector to
+	// the cache that sits a few layers below the builder stuff, which will
+	// implicitly filter what parts of the world the builder code gets to see at
+	// all.
+	nsFilter := cache.ObjectSelector{
+		Field: fields.SelectorFromSet(fields.Set{"metadata.namespace": tsNamespace}),
+	}
+	mgr, err := manager.New(config.GetConfigOrDie(), manager.Options{
+		NewCache: cache.BuilderWithOptions(cache.Options{
+			SelectorsByObject: map[client.Object]cache.ObjectSelector{
+				&corev1.Secret{}:      nsFilter,
+				&appsv1.StatefulSet{}: nsFilter,
+			},
+		}),
+	})
+	if err != nil {
+		startlog.Fatalf("could not create manager: %v", err)
+	}
+
+	sr := &ServiceReconciler{
+		Client:            mgr.GetClient(),
+		tsClient:          tsClient,
+		defaultTags:       strings.Split(tags, ","),
+		operatorNamespace: tsNamespace,
+		proxyImage:        image,
+		logger:            zlog.Named("service-reconciler"),
+	}
+
+	reconcileFilter := handler.EnqueueRequestsFromMapFunc(func(o client.Object) []reconcile.Request {
+		ls := o.GetLabels()
+		if ls[LabelManaged] != "true" {
+			return nil
+		}
+		if ls[LabelParentType] != "svc" {
+			return nil
+		}
+		return []reconcile.Request{
+			{
+				NamespacedName: types.NamespacedName{
+					Namespace: ls[LabelParentNamespace],
+					Name:      ls[LabelParentName],
+				},
+			},
+		}
+	})
+	err = builder.
+		ControllerManagedBy(mgr).
+		For(&corev1.Service{}).
+		Watches(&source.Kind{Type: &appsv1.StatefulSet{}}, reconcileFilter).
+		Watches(&source.Kind{Type: &corev1.Secret{}}, reconcileFilter).
+		Complete(sr)
+	if err != nil {
+		startlog.Fatalf("could not create controller: %v", err)
+	}
+
+	startlog.Infof("Startup complete, operator running")
+	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
+		startlog.Fatalf("could not start manager: %v", err)
+	}
+}
+
+const (
+	LabelManaged         = "tailscale.com/managed"
+	LabelParentType      = "tailscale.com/parent-resource-type"
+	LabelParentName      = "tailscale.com/parent-resource"
+	LabelParentNamespace = "tailscale.com/parent-resource-ns"
+
+	FinalizerName = "tailscale.com/finalizer"
+
+	AnnotationExpose   = "tailscale.com/expose"
+	AnnotationTags     = "tailscale.com/tags"
+	AnnotationHostname = "tailscale.com/hostname"
+)
+
+// ServiceReconciler is a simple ControllerManagedBy example implementation.
+type ServiceReconciler struct {
+	client.Client
+	tsClient          tsClient
+	defaultTags       []string
+	operatorNamespace string
+	proxyImage        string
+	logger            *zap.SugaredLogger
+}
+
+type tsClient interface {
+	CreateKey(ctx context.Context, caps tailscale.KeyCapabilities) (string, *tailscale.Key, error)
+	DeleteDevice(ctx context.Context, id string) error
+}
+
+func childResourceLabels(parent *corev1.Service) map[string]string {
+	// You might wonder why we're using owner references, since they seem to be
+	// built for exactly this. Unfortunately, Kubernetes does not support
+	// cross-namespace ownership, by design. This means we cannot make the
+	// service being exposed the owner of the implementation details of the
+	// proxying. Instead, we have to do our own filtering and tracking with
+	// labels.
+	return map[string]string{
+		LabelManaged:         "true",
+		LabelParentName:      parent.GetName(),
+		LabelParentNamespace: parent.GetNamespace(),
+		LabelParentType:      "svc",
+	}
+}
+
+func (a *ServiceReconciler) Reconcile(ctx context.Context, req reconcile.Request) (_ reconcile.Result, err error) {
+	logger := a.logger.With("service-ns", req.Namespace, "service-name", req.Name)
+	logger.Debugf("starting reconcile")
+	defer logger.Debugf("reconcile finished")
+
+	svc := new(corev1.Service)
+	err = a.Get(ctx, req.NamespacedName, svc)
+	if apierrors.IsNotFound(err) {
+		// Request object not found, could have been deleted after reconcile request.
+		logger.Debugf("service not found, assuming it was deleted")
+		return reconcile.Result{}, nil
+	} else if err != nil {
+		return reconcile.Result{}, fmt.Errorf("failed to get svc: %w", err)
+	}
+	if !svc.DeletionTimestamp.IsZero() || !a.shouldExpose(svc) {
+		logger.Debugf("service is being deleted or should not be exposed, cleaning up")
+		return reconcile.Result{}, a.maybeCleanup(ctx, logger, svc)
+	}
+
+	return reconcile.Result{}, a.maybeProvision(ctx, logger, svc)
+}
+
+// maybeCleanup removes any existing resources related to serving svc over tailscale.
+//
+// This function is responsible for removing the finalizer from the service,
+// once all associated resources are gone.
+func (a *ServiceReconciler) maybeCleanup(ctx context.Context, logger *zap.SugaredLogger, svc *corev1.Service) error {
+	ix := slices.Index(svc.Finalizers, FinalizerName)
+	if ix < 0 {
+		logger.Debugf("no finalizer, nothing to do")
+		return nil
+	}
+
+	ml := childResourceLabels(svc)
+
+	// Need to delete the StatefulSet first, and delete it with foreground
+	// cascading deletion. That way, the pod that's writing to the Secret will
+	// stop running before we start looking at the Secret's contents, and
+	// assuming k8s ordering semantics don't mess with us, that should avoid
+	// tailscale device deletion races where we fail to notice a device that
+	// should be removed.
+	sts, err := getSingleObject[appsv1.StatefulSet](ctx, a.Client, a.operatorNamespace, ml)
+	if err != nil {
+		return fmt.Errorf("getting statefulset: %w", err)
+	}
+	if sts != nil {
+		if !sts.GetDeletionTimestamp().IsZero() {
+			// Deletion in progress, check again later. We'll get another
+			// notification when the deletion is complete.
+			logger.Debugf("waiting for statefulset %s/%s deletion", sts.GetNamespace(), sts.GetName())
+			return nil
+		}
+		err := a.DeleteAllOf(ctx, &appsv1.StatefulSet{}, client.InNamespace(a.operatorNamespace), client.MatchingLabels(ml), client.PropagationPolicy(metav1.DeletePropagationForeground))
+		if err != nil {
+			return fmt.Errorf("deleting statefulset: %w", err)
+		}
+		logger.Debugf("started deletion of statefulset %s/%s", sts.GetNamespace(), sts.GetName())
+		return nil
+	}
+
+	id, _, err := a.getDeviceInfo(ctx, svc)
+	if err != nil {
+		return fmt.Errorf("getting device info: %w", err)
+	}
+	if id != "" {
+		// TODO: handle case where the device is already deleted, but the secret
+		// is still around.
+		if err := a.tsClient.DeleteDevice(ctx, id); err != nil {
+			return fmt.Errorf("deleting device: %w", err)
+		}
+	}
+
+	types := []client.Object{
+		&corev1.Service{},
+		&corev1.Secret{},
+	}
+	for _, typ := range types {
+		if err := a.DeleteAllOf(ctx, typ, client.InNamespace(a.operatorNamespace), client.MatchingLabels(ml)); err != nil {
+			return err
+		}
+	}
+
+	svc.Finalizers = append(svc.Finalizers[:ix], svc.Finalizers[ix+1:]...)
+	if err := a.Update(ctx, svc); err != nil {
+		return fmt.Errorf("failed to remove finalizer: %w", err)
+	}
+
+	// Unlike most log entries in the reconcile loop, this will get printed
+	// exactly once at the very end of cleanup, because the final step of
+	// cleanup removes the tailscale finalizer, which will make all future
+	// reconciles exit early.
+	logger.Infof("unexposed service from tailnet")
+	return nil
+}
+
+// maybeProvision ensures that svc is exposed over tailscale, taking any actions
+// necessary to reach that state.
+//
+// This function adds a finalizer to svc, ensuring that we can handle orderly
+// deprovisioning later.
+func (a *ServiceReconciler) maybeProvision(ctx context.Context, logger *zap.SugaredLogger, svc *corev1.Service) error {
+	hostname, err := nameForService(svc)
+	if err != nil {
+		return err
+	}
+
+	if !slices.Contains(svc.Finalizers, FinalizerName) {
+		// This log line is printed exactly once during initial provisioning,
+		// because once the finalizer is in place this block gets skipped. So,
+		// this is a nice place to tell the operator that the high level,
+		// multi-reconcile operation is underway.
+		logger.Infof("exposing service over tailscale")
+		svc.Finalizers = append(svc.Finalizers, FinalizerName)
+		if err := a.Update(ctx, svc); err != nil {
+			return fmt.Errorf("failed to add finalizer: %w", err)
+		}
+	}
+
+	// Do full reconcile.
+	hsvc, err := a.reconcileHeadlessService(ctx, logger, svc)
+	if err != nil {
+		return fmt.Errorf("failed to reconcile headless service: %w", err)
+	}
+
+	tags := a.defaultTags
+	if tstr, ok := svc.Annotations[AnnotationTags]; ok {
+		tags = strings.Split(tstr, ",")
+	}
+	secretName, err := a.createOrGetSecret(ctx, logger, svc, hsvc, tags)
+	if err != nil {
+		return fmt.Errorf("failed to create or get API key secret: %w", err)
+	}
+	_, err = a.reconcileSTS(ctx, logger, svc, hsvc, secretName, hostname)
+	if err != nil {
+		return fmt.Errorf("failed to reconcile statefulset: %w", err)
+	}
+
+	if !a.hasLoadBalancerClass(svc) {
+		logger.Debugf("service is not a LoadBalancer, so not updating ingress")
+		return nil
+	}
+
+	_, tsHost, err := a.getDeviceInfo(ctx, svc)
+	if err != nil {
+		return fmt.Errorf("failed to get device ID: %w", err)
+	}
+	if tsHost == "" {
+		logger.Debugf("no Tailscale hostname known yet, waiting for proxy pod to finish auth")
+		// No hostname yet. Wait for the proxy pod to auth.
+		svc.Status.LoadBalancer.Ingress = nil
+		if err := a.Status().Update(ctx, svc); err != nil {
+			return fmt.Errorf("failed to update service status: %w", err)
+		}
+		return nil
+	}
+
+	logger.Debugf("setting ingress hostname to %q", tsHost)
+	svc.Status.LoadBalancer.Ingress = []corev1.LoadBalancerIngress{
+		{
+			Hostname: tsHost,
+		},
+	}
+	if err := a.Status().Update(ctx, svc); err != nil {
+		return fmt.Errorf("failed to update service status: %w", err)
+	}
+	return nil
+}
+
+func (a *ServiceReconciler) shouldExpose(svc *corev1.Service) bool {
+	// Headless services can't be exposed, since there is no ClusterIP to
+	// forward to.
+	if svc.Spec.ClusterIP == "" || svc.Spec.ClusterIP == "None" {
+		return false
+	}
+
+	return a.hasLoadBalancerClass(svc) || a.hasAnnotation(svc)
+}
+
+func (a *ServiceReconciler) hasLoadBalancerClass(svc *corev1.Service) bool {
+	return svc != nil &&
+		svc.Spec.Type == corev1.ServiceTypeLoadBalancer &&
+		svc.Spec.LoadBalancerClass != nil &&
+		*svc.Spec.LoadBalancerClass == "tailscale"
+}
+
+func (a *ServiceReconciler) hasAnnotation(svc *corev1.Service) bool {
+	return svc != nil &&
+		svc.Annotations[AnnotationExpose] == "true"
+}
+
+func (a *ServiceReconciler) reconcileHeadlessService(ctx context.Context, logger *zap.SugaredLogger, svc *corev1.Service) (*corev1.Service, error) {
+	hsvc := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			GenerateName: "ts-" + svc.Name + "-",
+			Namespace:    a.operatorNamespace,
+			Labels:       childResourceLabels(svc),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "None",
+			Selector: map[string]string{
+				"app": string(svc.UID),
+			},
+		},
+	}
+	logger.Debugf("reconciling headless service for StatefulSet")
+	return createOrUpdate(ctx, a.Client, a.operatorNamespace, hsvc, func(svc *corev1.Service) { svc.Spec = hsvc.Spec })
+}
+
+func (a *ServiceReconciler) createOrGetSecret(ctx context.Context, logger *zap.SugaredLogger, svc, hsvc *corev1.Service, tags []string) (string, error) {
+	secret := &corev1.Secret{
+		ObjectMeta: metav1.ObjectMeta{
+			// Hardcode a -0 suffix so that in future, if we support
+			// multiple StatefulSet replicas, we can provision -N for
+			// those.
+			Name:      hsvc.Name + "-0",
+			Namespace: a.operatorNamespace,
+			Labels:    childResourceLabels(svc),
+		},
+	}
+	if err := a.Get(ctx, client.ObjectKeyFromObject(secret), secret); err == nil {
+		logger.Debugf("secret %s/%s already exists", secret.GetNamespace(), secret.GetName())
+		return secret.Name, nil
+	} else if !apierrors.IsNotFound(err) {
+		return "", err
+	}
+
+	// Secret doesn't exist yet, create one. Initially it contains
+	// only the Tailscale authkey, but once Tailscale starts it'll
+	// also store the daemon state.
+	sts, err := getSingleObject[appsv1.StatefulSet](ctx, a.Client, a.operatorNamespace, childResourceLabels(svc))
+	if err != nil {
+		return "", err
+	}
+	if sts != nil {
+		// StatefulSet exists, so we have already created the secret.
+		// If the secret is missing, they should delete the StatefulSet.
+		logger.Errorf("Tailscale proxy secret doesn't exist, but the corresponding StatefulSet %s/%s already does. Something is wrong, please delete the StatefulSet.", sts.GetNamespace(), sts.GetName())
+		return "", nil
+	}
+	// Create API Key secret which is going to be used by the statefulset
+	// to authenticate with Tailscale.
+	logger.Debugf("creating authkey for new tailscale proxy")
+	authKey, err := a.newAuthKey(ctx, tags)
+	if err != nil {
+		return "", err
+	}
+
+	secret.StringData = map[string]string{
+		"authkey": authKey,
+	}
+	if err := a.Create(ctx, secret); err != nil {
+		return "", err
+	}
+	return secret.Name, nil
+}
+
+func (a *ServiceReconciler) getDeviceInfo(ctx context.Context, svc *corev1.Service) (id, hostname string, err error) {
+	sec, err := getSingleObject[corev1.Secret](ctx, a.Client, a.operatorNamespace, childResourceLabels(svc))
+	if err != nil {
+		return "", "", err
+	}
+	id = string(sec.Data["device_id"])
+	if id == "" {
+		return "", "", nil
+	}
+	// Kubernetes chokes on well-formed FQDNs with the trailing dot, so we have
+	// to remove it.
+	hostname = strings.TrimSuffix(string(sec.Data["device_fqdn"]), ".")
+	if hostname == "" {
+		return "", "", nil
+	}
+	return id, hostname, nil
+}
+
+func (a *ServiceReconciler) newAuthKey(ctx context.Context, tags []string) (string, error) {
+	caps := tailscale.KeyCapabilities{
+		Devices: tailscale.KeyDeviceCapabilities{
+			Create: tailscale.KeyDeviceCreateCapabilities{
+				Reusable:      false,
+				Preauthorized: true,
+				Tags:          tags,
+			},
+		},
+	}
+	key, _, err := a.tsClient.CreateKey(ctx, caps)
+	if err != nil {
+		return "", err
+	}
+	return key, nil
+}
+
+//go:embed manifests/proxy.yaml
+var proxyYaml []byte
+
+func (a *ServiceReconciler) reconcileSTS(ctx context.Context, logger *zap.SugaredLogger, parentSvc, headlessSvc *corev1.Service, authKeySecret, hostname string) (*appsv1.StatefulSet, error) {
+	var ss appsv1.StatefulSet
+	if err := yaml.Unmarshal(proxyYaml, &ss); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal proxy spec: %w", err)
+	}
+	container := &ss.Spec.Template.Spec.Containers[0]
+	container.Image = a.proxyImage
+	container.Env = append(container.Env,
+		corev1.EnvVar{
+			Name:  "TS_DEST_IP",
+			Value: parentSvc.Spec.ClusterIP,
+		},
+		corev1.EnvVar{
+			Name:  "TS_KUBE_SECRET",
+			Value: authKeySecret,
+		},
+		corev1.EnvVar{
+			Name:  "TS_HOSTNAME",
+			Value: hostname,
+		})
+	ss.ObjectMeta = metav1.ObjectMeta{
+		Name:      headlessSvc.Name,
+		Namespace: a.operatorNamespace,
+		Labels:    childResourceLabels(parentSvc),
+	}
+	ss.Spec.ServiceName = headlessSvc.Name
+	ss.Spec.Selector = &metav1.LabelSelector{
+		MatchLabels: map[string]string{
+			"app": string(parentSvc.UID),
+		},
+	}
+	ss.Spec.Template.ObjectMeta.Labels = map[string]string{
+		"app": string(parentSvc.UID),
+	}
+	logger.Debugf("reconciling statefulset %s/%s", ss.GetNamespace(), ss.GetName())
+	return createOrUpdate(ctx, a.Client, a.operatorNamespace, &ss, func(s *appsv1.StatefulSet) { s.Spec = ss.Spec })
+}
+
+// ptrObject is a type constraint for pointer types that implement
+// client.Object.
+type ptrObject[T any] interface {
+	client.Object
+	*T
+}
+
+// createOrUpdate adds obj to the k8s cluster, unless the object already exists,
+// in which case update is called to make changes to it. If update is nil, the
+// existing object is returned unmodified.
+//
+// obj is looked up by its Name and Namespace if Name is set, otherwise it's
+// looked up by labels.
+func createOrUpdate[T any, O ptrObject[T]](ctx context.Context, c client.Client, ns string, obj O, update func(O)) (O, error) {
+	var (
+		existing O
+		err      error
+	)
+	if obj.GetName() != "" {
+		existing = new(T)
+		existing.SetName(obj.GetName())
+		existing.SetNamespace(obj.GetNamespace())
+		err = c.Get(ctx, client.ObjectKeyFromObject(obj), existing)
+	} else {
+		existing, err = getSingleObject[T, O](ctx, c, ns, obj.GetLabels())
+	}
+	if err == nil && existing != nil {
+		if update != nil {
+			update(existing)
+			if err := c.Update(ctx, existing); err != nil {
+				return nil, err
+			}
+		}
+		return existing, nil
+	}
+	if err != nil && !apierrors.IsNotFound(err) {
+		return nil, fmt.Errorf("failed to get object: %w", err)
+	}
+	if err := c.Create(ctx, obj); err != nil {
+		return nil, err
+	}
+	return obj, nil
+}
+
+// getSingleObject searches for k8s objects of type T
+// (e.g. corev1.Service) with the given labels, and returns
+// it. Returns nil if no objects match the labels, and an error if
+// more than one object matches.
+func getSingleObject[T any, O ptrObject[T]](ctx context.Context, c client.Client, ns string, labels map[string]string) (O, error) {
+	ret := O(new(T))
+	kinds, _, err := c.Scheme().ObjectKinds(ret)
+	if err != nil {
+		return nil, err
+	}
+	if len(kinds) != 1 {
+		// TODO: the runtime package apparently has a "pick the best
+		// GVK" function somewhere that might be good enough?
+		return nil, fmt.Errorf("more than 1 GroupVersionKind for %T", ret)
+	}
+
+	gvk := kinds[0]
+	gvk.Kind += "List"
+	lst := unstructured.UnstructuredList{}
+	lst.SetGroupVersionKind(gvk)
+	if err := c.List(ctx, &lst, client.InNamespace(ns), client.MatchingLabels(labels)); err != nil {
+		return nil, err
+	}
+
+	if len(lst.Items) == 0 {
+		return nil, nil
+	}
+	if len(lst.Items) > 1 {
+		return nil, fmt.Errorf("found multiple matching %T objects", ret)
+	}
+	if err := c.Scheme().Convert(&lst.Items[0], ret, nil); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+func defaultEnv(envName, defVal string) string {
+	v := os.Getenv(envName)
+	if v == "" {
+		return defVal
+	}
+	return v
+}
+
+func nameForService(svc *corev1.Service) (string, error) {
+	if h, ok := svc.Annotations[AnnotationHostname]; ok {
+		if err := dnsname.ValidLabel(h); err != nil {
+			return "", fmt.Errorf("invalid Tailscale hostname %q: %w", h, err)
+		}
+		return h, nil
+	}
+	return svc.Namespace + "-" + svc.Name, nil
+}

cmd/k8s-operator/operator_test.go

@@ -0,0 +1,841 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"context"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"go.uber.org/zap"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	"tailscale.com/client/tailscale"
+	"tailscale.com/types/ptr"
+)
+
+func TestLoadBalancerClass(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client:            fc,
+		tsClient:          ft,
+		defaultTags:       []string{"tag:k8s"},
+		operatorNamespace: "operator-ns",
+		proxyImage:        "tailscale/tailscale",
+		logger:            zl.Sugar(),
+	}
+
+	// Create a service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP:         "10.20.30.40",
+			Type:              corev1.ServiceTypeLoadBalancer,
+			LoadBalancerClass: ptr.To("tailscale"),
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test")
+
+	expectEqual(t, fc, expectedSecret(fullName))
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
+
+	// Normally the Tailscale proxy pod would come up here and write its info
+	// into the secret. Simulate that, then verify reconcile again and verify
+	// that we get to the end.
+	mustUpdate(t, fc, "operator-ns", fullName, func(s *corev1.Secret) {
+		if s.Data == nil {
+			s.Data = map[string][]byte{}
+		}
+		s.Data["device_id"] = []byte("ts-id-1234")
+		s.Data["device_fqdn"] = []byte("tailscale.device.name.")
+	})
+	expectReconciled(t, sr, "default", "test")
+	want := &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			UID:        types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP:         "10.20.30.40",
+			Type:              corev1.ServiceTypeLoadBalancer,
+			LoadBalancerClass: ptr.To("tailscale"),
+		},
+		Status: corev1.ServiceStatus{
+			LoadBalancer: corev1.LoadBalancerStatus{
+				Ingress: []corev1.LoadBalancerIngress{
+					{
+						Hostname: "tailscale.device.name",
+					},
+				},
+			},
+		},
+	}
+	expectEqual(t, fc, want)
+
+	// Turn the service back into a ClusterIP service, which should make the
+	// operator clean up.
+	mustUpdate(t, fc, "default", "test", func(s *corev1.Service) {
+		s.Spec.Type = corev1.ServiceTypeClusterIP
+		s.Spec.LoadBalancerClass = nil
+		// Fake client doesn't automatically delete the LoadBalancer status when
+		// changing away from the LoadBalancer type, we have to do
+		// controller-manager's work by hand.
+		s.Status = corev1.ServiceStatus{}
+	})
+	// synchronous StatefulSet deletion triggers a requeue. But, the StatefulSet
+	// didn't create any child resources since this is all faked, so the
+	// deletion goes through immediately.
+	expectReconciled(t, sr, "default", "test")
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	// The deletion triggers another reconcile, to finish the cleanup.
+	expectReconciled(t, sr, "default", "test")
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Service](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Secret](t, fc, "operator-ns", fullName)
+	want = &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			UID:       types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+}
+
+func TestAnnotations(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client:            fc,
+		tsClient:          ft,
+		defaultTags:       []string{"tag:k8s"},
+		operatorNamespace: "operator-ns",
+		proxyImage:        "tailscale/tailscale",
+		logger:            zl.Sugar(),
+	}
+
+	// Create a service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/expose": "true",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test")
+
+	expectEqual(t, fc, expectedSecret(fullName))
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
+	want := &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			UID:        types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/expose": "true",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+
+	// Turn the service back into a ClusterIP service, which should make the
+	// operator clean up.
+	mustUpdate(t, fc, "default", "test", func(s *corev1.Service) {
+		delete(s.ObjectMeta.Annotations, "tailscale.com/expose")
+	})
+	// synchronous StatefulSet deletion triggers a requeue. But, the StatefulSet
+	// didn't create any child resources since this is all faked, so the
+	// deletion goes through immediately.
+	expectReconciled(t, sr, "default", "test")
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	// Second time around, the rest of cleanup happens.
+	expectReconciled(t, sr, "default", "test")
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Service](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Secret](t, fc, "operator-ns", fullName)
+	want = &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			UID:       types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+}
+
+func TestAnnotationIntoLB(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client:            fc,
+		tsClient:          ft,
+		defaultTags:       []string{"tag:k8s"},
+		operatorNamespace: "operator-ns",
+		proxyImage:        "tailscale/tailscale",
+		logger:            zl.Sugar(),
+	}
+
+	// Create a service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/expose": "true",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test")
+
+	expectEqual(t, fc, expectedSecret(fullName))
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
+
+	// Normally the Tailscale proxy pod would come up here and write its info
+	// into the secret. Simulate that, since it would have normally happened at
+	// this point and the LoadBalancer is going to expect this.
+	mustUpdate(t, fc, "operator-ns", fullName, func(s *corev1.Secret) {
+		if s.Data == nil {
+			s.Data = map[string][]byte{}
+		}
+		s.Data["device_id"] = []byte("ts-id-1234")
+		s.Data["device_fqdn"] = []byte("tailscale.device.name.")
+	})
+	expectReconciled(t, sr, "default", "test")
+	want := &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			UID:        types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/expose": "true",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+
+	// Remove Tailscale's annotation, and at the same time convert the service
+	// into a tailscale LoadBalancer.
+	mustUpdate(t, fc, "default", "test", func(s *corev1.Service) {
+		delete(s.ObjectMeta.Annotations, "tailscale.com/expose")
+		s.Spec.Type = corev1.ServiceTypeLoadBalancer
+		s.Spec.LoadBalancerClass = ptr.To("tailscale")
+	})
+	expectReconciled(t, sr, "default", "test")
+	// None of the proxy machinery should have changed...
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
+	// ... but the service should have a LoadBalancer status.
+
+	want = &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			UID:        types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP:         "10.20.30.40",
+			Type:              corev1.ServiceTypeLoadBalancer,
+			LoadBalancerClass: ptr.To("tailscale"),
+		},
+		Status: corev1.ServiceStatus{
+			LoadBalancer: corev1.LoadBalancerStatus{
+				Ingress: []corev1.LoadBalancerIngress{
+					{
+						Hostname: "tailscale.device.name",
+					},
+				},
+			},
+		},
+	}
+	expectEqual(t, fc, want)
+}
+
+func TestLBIntoAnnotation(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client:            fc,
+		tsClient:          ft,
+		defaultTags:       []string{"tag:k8s"},
+		operatorNamespace: "operator-ns",
+		proxyImage:        "tailscale/tailscale",
+		logger:            zl.Sugar(),
+	}
+
+	// Create a service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP:         "10.20.30.40",
+			Type:              corev1.ServiceTypeLoadBalancer,
+			LoadBalancerClass: ptr.To("tailscale"),
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test")
+
+	expectEqual(t, fc, expectedSecret(fullName))
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
+
+	// Normally the Tailscale proxy pod would come up here and write its info
+	// into the secret. Simulate that, then verify reconcile again and verify
+	// that we get to the end.
+	mustUpdate(t, fc, "operator-ns", fullName, func(s *corev1.Secret) {
+		if s.Data == nil {
+			s.Data = map[string][]byte{}
+		}
+		s.Data["device_id"] = []byte("ts-id-1234")
+		s.Data["device_fqdn"] = []byte("tailscale.device.name.")
+	})
+	expectReconciled(t, sr, "default", "test")
+	want := &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			UID:        types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP:         "10.20.30.40",
+			Type:              corev1.ServiceTypeLoadBalancer,
+			LoadBalancerClass: ptr.To("tailscale"),
+		},
+		Status: corev1.ServiceStatus{
+			LoadBalancer: corev1.LoadBalancerStatus{
+				Ingress: []corev1.LoadBalancerIngress{
+					{
+						Hostname: "tailscale.device.name",
+					},
+				},
+			},
+		},
+	}
+	expectEqual(t, fc, want)
+
+	// Turn the service back into a ClusterIP service, but also add the
+	// tailscale annotation.
+	mustUpdate(t, fc, "default", "test", func(s *corev1.Service) {
+		s.ObjectMeta.Annotations = map[string]string{
+			"tailscale.com/expose": "true",
+		}
+		s.Spec.Type = corev1.ServiceTypeClusterIP
+		s.Spec.LoadBalancerClass = nil
+		// Fake client doesn't automatically delete the LoadBalancer status when
+		// changing away from the LoadBalancer type, we have to do
+		// controller-manager's work by hand.
+		s.Status = corev1.ServiceStatus{}
+	})
+	expectReconciled(t, sr, "default", "test")
+
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
+
+	want = &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			Annotations: map[string]string{
+				"tailscale.com/expose": "true",
+			},
+			UID: types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+}
+
+func TestCustomHostname(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client:            fc,
+		tsClient:          ft,
+		defaultTags:       []string{"tag:k8s"},
+		operatorNamespace: "operator-ns",
+		proxyImage:        "tailscale/tailscale",
+		logger:            zl.Sugar(),
+	}
+
+	// Create a service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/expose":   "true",
+				"tailscale.com/hostname": "reindeer-flotilla",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test")
+
+	expectEqual(t, fc, expectedSecret(fullName))
+	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedSTS(shortName, fullName, "reindeer-flotilla"))
+	want := &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "test",
+			Namespace:  "default",
+			Finalizers: []string{"tailscale.com/finalizer"},
+			UID:        types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/expose":   "true",
+				"tailscale.com/hostname": "reindeer-flotilla",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+
+	// Turn the service back into a ClusterIP service, which should make the
+	// operator clean up.
+	mustUpdate(t, fc, "default", "test", func(s *corev1.Service) {
+		delete(s.ObjectMeta.Annotations, "tailscale.com/expose")
+	})
+	// synchronous StatefulSet deletion triggers a requeue. But, the StatefulSet
+	// didn't create any child resources since this is all faked, so the
+	// deletion goes through immediately.
+	expectReconciled(t, sr, "default", "test")
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	// Second time around, the rest of cleanup happens.
+	expectReconciled(t, sr, "default", "test")
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Service](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Secret](t, fc, "operator-ns", fullName)
+	want = &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			UID:       types.UID("1234-UID"),
+			Annotations: map[string]string{
+				"tailscale.com/hostname": "reindeer-flotilla",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeClusterIP,
+		},
+	}
+	expectEqual(t, fc, want)
+}
+
+func expectedSecret(name string) *corev1.Secret {
+	return &corev1.Secret{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Secret",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      name,
+			Namespace: "operator-ns",
+			Labels: map[string]string{
+				"tailscale.com/managed":              "true",
+				"tailscale.com/parent-resource":      "test",
+				"tailscale.com/parent-resource-ns":   "default",
+				"tailscale.com/parent-resource-type": "svc",
+			},
+		},
+		StringData: map[string]string{
+			"authkey": "secret-authkey",
+		},
+	}
+}
+
+func expectedHeadlessService(name string) *corev1.Service {
+	return &corev1.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:         name,
+			GenerateName: "ts-test-",
+			Namespace:    "operator-ns",
+			Labels: map[string]string{
+				"tailscale.com/managed":              "true",
+				"tailscale.com/parent-resource":      "test",
+				"tailscale.com/parent-resource-ns":   "default",
+				"tailscale.com/parent-resource-type": "svc",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			Selector: map[string]string{
+				"app": "1234-UID",
+			},
+			ClusterIP: "None",
+		},
+	}
+}
+
+func expectedSTS(stsName, secretName, hostname string) *appsv1.StatefulSet {
+	return &appsv1.StatefulSet{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "StatefulSet",
+			APIVersion: "apps/v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      stsName,
+			Namespace: "operator-ns",
+			Labels: map[string]string{
+				"tailscale.com/managed":              "true",
+				"tailscale.com/parent-resource":      "test",
+				"tailscale.com/parent-resource-ns":   "default",
+				"tailscale.com/parent-resource-type": "svc",
+			},
+		},
+		Spec: appsv1.StatefulSetSpec{
+			Replicas: ptr.To[int32](1),
+			Selector: &metav1.LabelSelector{
+				MatchLabels: map[string]string{"app": "1234-UID"},
+			},
+			ServiceName: stsName,
+			Template: corev1.PodTemplateSpec{
+				ObjectMeta: metav1.ObjectMeta{
+					DeletionGracePeriodSeconds: ptr.To[int64](10),
+					Labels:                     map[string]string{"app": "1234-UID"},
+				},
+				Spec: corev1.PodSpec{
+					ServiceAccountName: "proxies",
+					InitContainers: []corev1.Container{
+						{
+							Name:    "sysctler",
+							Image:   "busybox",
+							Command: []string{"/bin/sh"},
+							Args:    []string{"-c", "sysctl -w net.ipv4.ip_forward=1 net.ipv6.conf.all.forwarding=1"},
+							SecurityContext: &corev1.SecurityContext{
+								Privileged: ptr.To(true),
+							},
+						},
+					},
+					Containers: []v1.Container{
+						{
+							Name:  "tailscale",
+							Image: "tailscale/tailscale",
+							Env: []v1.EnvVar{
+								{Name: "TS_USERSPACE", Value: "false"},
+								{Name: "TS_AUTH_ONCE", Value: "true"},
+								{Name: "TS_DEST_IP", Value: "10.20.30.40"},
+								{Name: "TS_KUBE_SECRET", Value: secretName},
+								{Name: "TS_HOSTNAME", Value: hostname},
+							},
+							SecurityContext: &corev1.SecurityContext{
+								Capabilities: &corev1.Capabilities{
+									Add: []corev1.Capability{"NET_ADMIN"},
+								},
+							},
+							ImagePullPolicy: "Always",
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func findGenName(t *testing.T, client client.Client, ns, name string) (full, noSuffix string) {
+	t.Helper()
+	labels := map[string]string{
+		LabelManaged:         "true",
+		LabelParentName:      name,
+		LabelParentNamespace: ns,
+		LabelParentType:      "svc",
+	}
+	s, err := getSingleObject[corev1.Secret](context.Background(), client, "operator-ns", labels)
+	if err != nil {
+		t.Fatalf("finding secret for %q: %v", name, err)
+	}
+	return s.GetName(), strings.TrimSuffix(s.GetName(), "-0")
+}
+
+func mustCreate(t *testing.T, client client.Client, obj client.Object) {
+	t.Helper()
+	if err := client.Create(context.Background(), obj); err != nil {
+		t.Fatalf("creating %q: %v", obj.GetName(), err)
+	}
+}
+
+func mustUpdate[T any, O ptrObject[T]](t *testing.T, client client.Client, ns, name string, update func(O)) {
+	t.Helper()
+	obj := O(new(T))
+	if err := client.Get(context.Background(), types.NamespacedName{
+		Name:      name,
+		Namespace: ns,
+	}, obj); err != nil {
+		t.Fatalf("getting %q: %v", name, err)
+	}
+	update(obj)
+	if err := client.Update(context.Background(), obj); err != nil {
+		t.Fatalf("updating %q: %v", name, err)
+	}
+}
+
+func expectEqual[T any, O ptrObject[T]](t *testing.T, client client.Client, want O) {
+	t.Helper()
+	got := O(new(T))
+	if err := client.Get(context.Background(), types.NamespacedName{
+		Name:      want.GetName(),
+		Namespace: want.GetNamespace(),
+	}, got); err != nil {
+		t.Fatalf("getting %q: %v", want.GetName(), err)
+	}
+	// The resource version changes eagerly whenever the operator does even a
+	// no-op update. Asserting a specific value leads to overly brittle tests,
+	// so just remove it from both got and want.
+	got.SetResourceVersion("")
+	want.SetResourceVersion("")
+	if diff := cmp.Diff(got, want); diff != "" {
+		t.Fatalf("unexpected object (-got +want):\n%s", diff)
+	}
+}
+
+func expectMissing[T any, O ptrObject[T]](t *testing.T, client client.Client, ns, name string) {
+	t.Helper()
+	obj := O(new(T))
+	if err := client.Get(context.Background(), types.NamespacedName{
+		Name:      name,
+		Namespace: ns,
+	}, obj); !apierrors.IsNotFound(err) {
+		t.Fatalf("object %s/%s unexpectedly present, wanted missing", ns, name)
+	}
+}
+
+func expectReconciled(t *testing.T, sr *ServiceReconciler, ns, name string) {
+	t.Helper()
+	req := reconcile.Request{
+		NamespacedName: types.NamespacedName{
+			Name:      name,
+			Namespace: ns,
+		},
+	}
+	res, err := sr.Reconcile(context.Background(), req)
+	if err != nil {
+		t.Fatalf("Reconcile: unexpected error: %v", err)
+	}
+	if res.Requeue {
+		t.Fatalf("unexpected immediate requeue")
+	}
+	if res.RequeueAfter != 0 {
+		t.Fatalf("unexpected timed requeue (%v)", res.RequeueAfter)
+	}
+}
+
+func expectRequeue(t *testing.T, sr *ServiceReconciler, ns, name string) {
+	t.Helper()
+	req := reconcile.Request{
+		NamespacedName: types.NamespacedName{
+			Name:      name,
+			Namespace: ns,
+		},
+	}
+	res, err := sr.Reconcile(context.Background(), req)
+	if err != nil {
+		t.Fatalf("Reconcile: unexpected error: %v", err)
+	}
+	if res.Requeue {
+		t.Fatalf("unexpected immediate requeue")
+	}
+	if res.RequeueAfter == 0 {
+		t.Fatalf("expected timed requeue, got success")
+	}
+}
+
+type fakeTSClient struct {
+	sync.Mutex
+	keyRequests []tailscale.KeyCapabilities
+	deleted     []string
+}
+
+func (c *fakeTSClient) CreateKey(ctx context.Context, caps tailscale.KeyCapabilities) (string, *tailscale.Key, error) {
+	c.Lock()
+	defer c.Unlock()
+	c.keyRequests = append(c.keyRequests, caps)
+	k := &tailscale.Key{
+		ID:           "key",
+		Created:      time.Now(),
+		Expires:      time.Now().Add(24 * time.Hour),
+		Capabilities: caps,
+	}
+	return "secret-authkey", k, nil
+}
+
+func (c *fakeTSClient) DeleteDevice(ctx context.Context, deviceID string) error {
+	c.Lock()
+	defer c.Unlock()
+	c.deleted = append(c.deleted, deviceID)
+	return nil
+}
+
+func (c *fakeTSClient) KeyRequests() []tailscale.KeyCapabilities {
+	c.Lock()
+	defer c.Unlock()
+	return c.keyRequests
+}
+
+func (c *fakeTSClient) Deleted() []string {
+	c.Lock()
+	defer c.Unlock()
+	return c.deleted
+}

cmd/microproxy/microproxy.go

@@ -1,189 +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 := tsweb.NewMux(http.HandlerFunc(debugHandler))
-	mux.Handle("/metrics", tsweb.Protected(proxy))
-	mux.Handle("/varz", tsweb.Protected(tsweb.StdHandler(&goVarsHandler{*goVarsURL}, log.Printf)))
-
-	ch := &certHolder{
-		hostname: *hostname,
-		path:     filepath.Join(*certdir, *hostname),
-	}
-
-	httpsrv := &http.Server{
-		Addr:    *addr,
-		Handler: mux,
-	}
-
-	if !*insecure {
-		httpsrv.TLSConfig = &tls.Config{GetCertificate: ch.GetCertificate}
-		err = httpsrv.ListenAndServeTLS("", "")
-	} else {
-		err = httpsrv.ListenAndServe()
-	}
-	if err != nil && err != http.ErrServerClosed {
-		log.Fatal(err)
-	}
-}
-
-type goVarsHandler struct {
-	url string
-}
-
-func promPrint(w io.Writer, prefix string, obj map[string]interface{}) {
-	for k, i := range obj {
-		if prefix != "" {
-			k = prefix + "_" + k
-		}
-		switch v := i.(type) {
-		case map[string]interface{}:
-			promPrint(w, k, v)
-		case float64:
-			const saveConfigReject = "control_save_config_rejected_"
-			const saveConfig = "control_save_config_"
-			switch {
-			case strings.HasPrefix(k, saveConfigReject):
-				fmt.Fprintf(w, "control_save_config_rejected{reason=%q} %f\n", k[len(saveConfigReject):], v)
-			case strings.HasPrefix(k, saveConfig):
-				fmt.Fprintf(w, "control_save_config{reason=%q} %f\n", k[len(saveConfig):], v)
-			default:
-				fmt.Fprintf(w, "%s %f\n", k, v)
-			}
-		default:
-			fmt.Fprintf(w, "# Skipping key %q, unhandled type %T\n", k, v)
-		}
-	}
-}
-
-func (h *goVarsHandler) ServeHTTPReturn(w http.ResponseWriter, r *http.Request) error {
-	resp, err := http.Get(h.url)
-	if err != nil {
-		return tsweb.Error(http.StatusInternalServerError, "fetch failed", err)
-	}
-	defer resp.Body.Close()
-	var mon map[string]interface{}
-	if err := json.NewDecoder(resp.Body).Decode(&mon); err != nil {
-		return tsweb.Error(http.StatusInternalServerError, "fetch failed", err)
-	}
-
-	w.WriteHeader(http.StatusOK)
-	promPrint(w, "", mon)
-	return nil
-}
-
-// certHolder loads and caches a TLS certificate from disk, reloading
-// it every hour.
-type certHolder struct {
-	hostname string // only hostname allowed in SNI
-	path     string // path of certificate+key combined PEM file
-
-	mu     sync.Mutex
-	cert   *tls.Certificate // cached parsed cert+key
-	loaded time.Time
-}
-
-func (c *certHolder) GetCertificate(ch *tls.ClientHelloInfo) (*tls.Certificate, error) {
-	if ch.ServerName != c.hostname {
-		return nil, fmt.Errorf("wrong client SNI %q", ch.ServerName)
-	}
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	if time.Since(c.loaded) > time.Hour {
-		if err := c.loadLocked(); err != nil {
-			log.Printf("Reloading cert %q: %v", c.path, err)
-			// continue anyway, we might be able to serve off the stale cert.
-		}
-	}
-	return c.cert, nil
-}
-
-// load reloads the TLS certificate and key from disk. Caller must
-// hold mu.
-func (c *certHolder) loadLocked() error {
-	bs, err := ioutil.ReadFile(c.path)
-	if err != nil {
-		return fmt.Errorf("reading %q: %v", c.path, err)
-	}
-	cert, err := tls.X509KeyPair(bs, bs)
-	if err != nil {
-		return fmt.Errorf("parsing %q: %v", c.path, err)
-	}
-
-	c.cert = &cert
-	c.loaded = time.Now()
-	return nil
-}
-
-// debugHandler serves a page with links to tsweb-managed debug URLs
-// at /debug/.
-func debugHandler(w http.ResponseWriter, r *http.Request) {
-	f := func(format string, args ...interface{}) { fmt.Fprintf(w, format, args...) }
-	f(`<html><body>
-<h1>microproxy debug</h1>
-<ul>
-`)
-	f("<li><b>Hostname:</b> %v</li>\n", *hostname)
-	f("<li><b>Uptime:</b> %v</li>\n", tsweb.Uptime())
-	f(`<li><a href="/debug/vars">/debug/vars</a> (Go)</li>
-   <li><a href="/debug/varz">/debug/varz</a> (Prometheus)</li>
-   <li><a href="/debug/pprof/">/debug/pprof/</a></li>
-   <li><a href="/debug/pprof/goroutine?debug=1">/debug/pprof/goroutine</a> (collapsed)</li>
-   <li><a href="/debug/pprof/goroutine?debug=2">/debug/pprof/goroutine</a> (full)</li>
-<ul>
-</html>
-`)
-}

cmd/mkmanifest/main.go

@@ -0,0 +1,51 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// The mkmanifest command is a simple helper utility to create a '.syso' file
+// that contains a Windows manifest file.
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/tc-hib/winres"
+)
+
+func main() {
+	if len(os.Args) != 4 {
+		log.Fatalf("usage: %s arch manifest.xml output.syso", os.Args[0])
+	}
+
+	arch := winres.Arch(os.Args[1])
+	switch arch {
+	case winres.ArchAMD64, winres.ArchARM64, winres.ArchI386, winres.ArchARM:
+	default:
+		log.Fatalf("unsupported arch: %s", arch)
+	}
+
+	manifest, err := os.ReadFile(os.Args[2])
+	if err != nil {
+		log.Fatalf("error reading manifest file %q: %v", os.Args[2], err)
+	}
+
+	out := os.Args[3]
+
+	// Start by creating an empty resource set
+	rs := winres.ResourceSet{}
+
+	// Add resources
+	rs.Set(winres.RT_MANIFEST, winres.ID(1), 0, manifest)
+
+	// Compile to a COFF object file
+	f, err := os.Create(out)
+	if err != nil {
+		log.Fatalf("error creating output file %q: %v", out, err)
+	}
+	if err := rs.WriteObject(f, arch); err != nil {
+		log.Fatalf("error writing object: %v", err)
+	}
+	if err := f.Close(); err != nil {
+		log.Fatalf("error writing output file %q: %v", out, err)
+	}
+}

cmd/mkpkg/main.go

@@ -1,11 +1,11 @@
-// 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.
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
 
 // mkpkg builds the Tailscale rpm and deb packages.
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
 	"os"
@@ -14,13 +14,15 @@ 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
 // into a map of filePathOnDisk -> filePathInPackage.
 func parseFiles(s string) (map[string]string, error) {
 	ret := map[string]string{}
+	if len(s) == 0 {
+		return ret, nil
+	}
 	for _, f := range strings.Split(s, ",") {
 		fs := strings.Split(f, ":")
 		if len(fs) != 2 {
@@ -41,19 +43,22 @@ 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")
+	recommends := flag.String("recommends", "", "comma-separated list of packages this package recommends")
+	flag.Parse()
 
 	filesMap, err := parseFiles(*files)
 	if err != nil {
@@ -65,12 +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{
@@ -88,6 +93,9 @@ func main() {
 	if len(*depends) != 0 {
 		info.Overridables.Depends = strings.Split(*depends, ",")
 	}
+	if len(*recommends) != 0 {
+		info.Overridables.Recommends = strings.Split(*recommends, ",")
+	}
 	if *replaces != "" {
 		info.Overridables.Replaces = []string{*replaces}
 		info.Overridables.Conflicts = []string{*replaces}

cmd/nardump/README.md

@@ -0,0 +1,7 @@
+# nardump
+
+nardump is like nix-store --dump, but in Go, writing a NAR file (tar-like,
+but focused on being reproducible) to stdout or to a hash with the --sri flag.
+
+It lets us calculate the Nix sha256 in shell.nix without the person running
+git-pull-oss.sh having Nix available.

cmd/nardump/nardump.go

@@ -0,0 +1,184 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// nardump is like nix-store --dump, but in Go, writing a NAR
+// file (tar-like, but focused on being reproducible) to stdout
+// or to a hash with the --sri flag.
+//
+// It lets us calculate a Nix sha256 without the person running
+// git-pull-oss.sh having Nix available.
+package main
+
+// For the format, see:
+// See https://gist.github.com/jbeda/5c79d2b1434f0018d693
+
+import (
+	"bufio"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/binary"
+	"flag"
+	"fmt"
+	"io"
+	"io/fs"
+	"log"
+	"os"
+	"path"
+	"sort"
+)
+
+var sri = flag.Bool("sri", false, "print SRI")
+
+func main() {
+	flag.Parse()
+	if flag.NArg() != 1 {
+		log.Fatal("usage: nardump <dir>")
+	}
+	arg := flag.Arg(0)
+	if err := os.Chdir(arg); err != nil {
+		log.Fatal(err)
+	}
+	if *sri {
+		hash := sha256.New()
+		if err := writeNAR(hash, os.DirFS(".")); err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("sha256-%s\n", base64.StdEncoding.EncodeToString(hash.Sum(nil)))
+		return
+	}
+	bw := bufio.NewWriter(os.Stdout)
+	if err := writeNAR(bw, os.DirFS(".")); err != nil {
+		log.Fatal(err)
+	}
+	bw.Flush()
+}
+
+// writeNARError is a sentinel panic type that's recovered by writeNAR
+// and converted into the wrapped error.
+type writeNARError struct{ err error }
+
+// narWriter writes NAR files.
+type narWriter struct {
+	w  io.Writer
+	fs fs.FS
+}
+
+// writeNAR writes a NAR file to w from the root of fs.
+func writeNAR(w io.Writer, fs fs.FS) (err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			if we, ok := e.(writeNARError); ok {
+				err = we.err
+				return
+			}
+			panic(e)
+		}
+	}()
+	nw := &narWriter{w: w, fs: fs}
+	nw.str("nix-archive-1")
+	return nw.writeDir(".")
+}
+
+func (nw *narWriter) writeDir(dirPath string) error {
+	ents, err := fs.ReadDir(nw.fs, dirPath)
+	if err != nil {
+		return err
+	}
+	sort.Slice(ents, func(i, j int) bool {
+		return ents[i].Name() < ents[j].Name()
+	})
+	nw.str("(")
+	nw.str("type")
+	nw.str("directory")
+	for _, ent := range ents {
+		nw.str("entry")
+		nw.str("(")
+		nw.str("name")
+		nw.str(ent.Name())
+		nw.str("node")
+		mode := ent.Type()
+		sub := path.Join(dirPath, ent.Name())
+		var err error
+		switch {
+		case mode.IsRegular():
+			err = nw.writeRegular(sub)
+		case mode.IsDir():
+			err = nw.writeDir(sub)
+		default:
+			// TODO(bradfitz): symlink, but requires fighting io/fs a bit
+			// to get at Readlink or the osFS via fs. But for now
+			// we don't need symlinks because they're not in Go's archive.
+			return fmt.Errorf("unsupported file type %v at %q", sub, mode)
+		}
+		if err != nil {
+			return err
+		}
+		nw.str(")")
+	}
+	nw.str(")")
+	return nil
+}
+
+func (nw *narWriter) writeRegular(path string) error {
+	nw.str("(")
+	nw.str("type")
+	nw.str("regular")
+	fi, err := fs.Stat(nw.fs, path)
+	if err != nil {
+		return err
+	}
+	if fi.Mode()&0111 != 0 {
+		nw.str("executable")
+		nw.str("")
+	}
+	contents, err := fs.ReadFile(nw.fs, path)
+	if err != nil {
+		return err
+	}
+	nw.str("contents")
+	if err := writeBytes(nw.w, contents); err != nil {
+		return err
+	}
+	nw.str(")")
+	return nil
+}
+
+func (nw *narWriter) str(s string) {
+	if err := writeString(nw.w, s); err != nil {
+		panic(writeNARError{err})
+	}
+}
+
+func writeString(w io.Writer, s string) error {
+	var buf [8]byte
+	binary.LittleEndian.PutUint64(buf[:], uint64(len(s)))
+	if _, err := w.Write(buf[:]); err != nil {
+		return err
+	}
+	if _, err := io.WriteString(w, s); err != nil {
+		return err
+	}
+	return writePad(w, len(s))
+}
+
+func writeBytes(w io.Writer, b []byte) error {
+	var buf [8]byte
+	binary.LittleEndian.PutUint64(buf[:], uint64(len(b)))
+	if _, err := w.Write(buf[:]); err != nil {
+		return err
+	}
+	if _, err := w.Write(b); err != nil {
+		return err
+	}
+	return writePad(w, len(b))
+}
+
+func writePad(w io.Writer, n int) error {
+	pad := n % 8
+	if pad == 0 {
+		return nil
+	}
+	var zeroes [8]byte
+	_, err := w.Write(zeroes[:8-pad])
+	return err
+}

cmd/netlogfmt/main.go

@@ -0,0 +1,386 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// netlogfmt parses a stream of JSON log messages from stdin and
+// formats the network traffic logs produced by "tailscale.com/wgengine/netlog"
+// according to the schema in "tailscale.com/types/netlogtype.Message"
+// in a more humanly readable format.
+//
+// Example usage:
+//
+//	$ cat netlog.json | go run tailscale.com/cmd/netlogfmt
+//	=========================================================================================
+//	NodeID: n123456CNTRL
+//	Logged: 2022-10-13T20:23:10.165Z
+//	Window: 2022-10-13T20:23:09.644Z (5s)
+//	---------------------------------------------------  Tx[P/s]  Tx[B/s]  Rx[P/s]    Rx[B/s]
+//	VirtualTraffic:                                       16.80    1.64Ki   11.20      1.03Ki
+//	    TCP:    100.109.51.95:22 -> 100.85.80.41:42912    16.00    1.59Ki   10.40   1008.84
+//	    TCP: 100.109.51.95:21291 -> 100.107.177.2:53133    0.40   27.60      0.40     24.20
+//	    TCP: 100.109.51.95:21291 -> 100.107.177.2:53134    0.40   23.40      0.40     24.20
+//	PhysicalTraffic:                                      16.80    2.32Ki   11.20      1.48Ki
+//	                100.85.80.41 -> 192.168.0.101:41641   16.00    2.23Ki   10.40      1.40Ki
+//	               100.107.177.2 -> 192.168.0.100:41641    0.80   83.20      0.80     83.20
+//	=========================================================================================
+package main
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"net/http"
+	"net/netip"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/dsnet/try"
+	jsonv2 "github.com/go-json-experiment/json"
+	"golang.org/x/exp/maps"
+	"golang.org/x/exp/slices"
+	"tailscale.com/logtail"
+	"tailscale.com/types/netlogtype"
+	"tailscale.com/util/must"
+)
+
+var (
+	resolveNames = flag.Bool("resolve-names", false, "convert tailscale IP addresses to hostnames; must also specify --api-key and --tailnet-id")
+	apiKey       = flag.String("api-key", "", "API key to query the Tailscale API with; see https://login.tailscale.com/admin/settings/keys")
+	tailnetName  = flag.String("tailnet-name", "", "tailnet domain name to lookup devices in; see https://login.tailscale.com/admin/settings/general")
+)
+
+var namesByAddr map[netip.Addr]string
+
+func main() {
+	flag.Parse()
+	if *resolveNames {
+		namesByAddr = mustMakeNamesByAddr()
+	}
+
+	// The logic handles a stream of arbitrary JSON.
+	// So long as a JSON object seems like a network log message,
+	// then this will unmarshal and print it.
+	if err := processStream(os.Stdin); err != nil {
+		if err == io.EOF {
+			return
+		}
+		log.Fatalf("processStream: %v", err)
+	}
+}
+
+func processStream(r io.Reader) (err error) {
+	defer try.Handle(&err)
+	dec := jsonv2.NewDecoder(os.Stdin)
+	for {
+		processValue(dec)
+	}
+}
+
+func processValue(dec *jsonv2.Decoder) {
+	switch dec.PeekKind() {
+	case '[':
+		processArray(dec)
+	case '{':
+		processObject(dec)
+	default:
+		try.E(dec.SkipValue())
+	}
+}
+
+func processArray(dec *jsonv2.Decoder) {
+	try.E1(dec.ReadToken()) // parse '['
+	for dec.PeekKind() != ']' {
+		processValue(dec)
+	}
+	try.E1(dec.ReadToken()) // parse ']'
+}
+
+func processObject(dec *jsonv2.Decoder) {
+	var hasTraffic bool
+	var rawMsg []byte
+	try.E1(dec.ReadToken()) // parse '{'
+	for dec.PeekKind() != '}' {
+		// Capture any members that could belong to a network log message.
+		switch name := try.E1(dec.ReadToken()); name.String() {
+		case "virtualTraffic", "subnetTraffic", "exitTraffic", "physicalTraffic":
+			hasTraffic = true
+			fallthrough
+		case "logtail", "nodeId", "logged", "start", "end":
+			if len(rawMsg) == 0 {
+				rawMsg = append(rawMsg, '{')
+			} else {
+				rawMsg = append(rawMsg[:len(rawMsg)-1], ',')
+			}
+			rawMsg = append(append(append(rawMsg, '"'), name.String()...), '"')
+			rawMsg = append(rawMsg, ':')
+			rawMsg = append(rawMsg, try.E1(dec.ReadValue())...)
+			rawMsg = append(rawMsg, '}')
+		default:
+			processValue(dec)
+		}
+	}
+	try.E1(dec.ReadToken()) // parse '}'
+
+	// If this appears to be a network log message, then unmarshal and print it.
+	if hasTraffic {
+		var msg message
+		try.E(jsonv2.Unmarshal(rawMsg, &msg))
+		printMessage(msg)
+	}
+}
+
+type message struct {
+	Logtail struct {
+		ID     logtail.PublicID `json:"id"`
+		Logged time.Time        `json:"server_time"`
+	} `json:"logtail"`
+	Logged time.Time `json:"logged"`
+	netlogtype.Message
+}
+
+func printMessage(msg message) {
+	// Construct a table of network traffic per connection.
+	rows := [][7]string{{3: "Tx[P/s]", 4: "Tx[B/s]", 5: "Rx[P/s]", 6: "Rx[B/s]"}}
+	duration := msg.End.Sub(msg.Start)
+	addRows := func(heading string, traffic []netlogtype.ConnectionCounts) {
+		if len(traffic) == 0 {
+			return
+		}
+		slices.SortFunc(traffic, func(x, y netlogtype.ConnectionCounts) bool {
+			nx := x.TxPackets + x.TxBytes + x.RxPackets + x.RxBytes
+			ny := y.TxPackets + y.TxBytes + y.RxPackets + y.RxBytes
+			return nx > ny
+		})
+		var sum netlogtype.Counts
+		for _, cc := range traffic {
+			sum = sum.Add(cc.Counts)
+		}
+		rows = append(rows, [7]string{
+			0: heading + ":",
+			3: formatSI(float64(sum.TxPackets) / duration.Seconds()),
+			4: formatIEC(float64(sum.TxBytes) / duration.Seconds()),
+			5: formatSI(float64(sum.RxPackets) / duration.Seconds()),
+			6: formatIEC(float64(sum.RxBytes) / duration.Seconds()),
+		})
+		if len(traffic) == 1 && traffic[0].Connection.IsZero() {
+			return // this is already a summary counts
+		}
+		formatAddrPort := func(a netip.AddrPort) string {
+			if !a.IsValid() {
+				return ""
+			}
+			if name, ok := namesByAddr[a.Addr()]; ok {
+				if a.Port() == 0 {
+					return name
+				}
+				return name + ":" + strconv.Itoa(int(a.Port()))
+			}
+			if a.Port() == 0 {
+				return a.Addr().String()
+			}
+			return a.String()
+		}
+		for _, cc := range traffic {
+			row := [7]string{
+				0: "    ",
+				1: formatAddrPort(cc.Src),
+				2: formatAddrPort(cc.Dst),
+				3: formatSI(float64(cc.TxPackets) / duration.Seconds()),
+				4: formatIEC(float64(cc.TxBytes) / duration.Seconds()),
+				5: formatSI(float64(cc.RxPackets) / duration.Seconds()),
+				6: formatIEC(float64(cc.RxBytes) / duration.Seconds()),
+			}
+			if cc.Proto > 0 {
+				row[0] += cc.Proto.String() + ":"
+			}
+			rows = append(rows, row)
+		}
+	}
+	addRows("VirtualTraffic", msg.VirtualTraffic)
+	addRows("SubnetTraffic", msg.SubnetTraffic)
+	addRows("ExitTraffic", msg.ExitTraffic)
+	addRows("PhysicalTraffic", msg.PhysicalTraffic)
+
+	// Compute the maximum width of each field.
+	var maxWidths [7]int
+	for _, row := range rows {
+		for i, col := range row {
+			if maxWidths[i] < len(col) && !(i == 0 && !strings.HasPrefix(col, " ")) {
+				maxWidths[i] = len(col)
+			}
+		}
+	}
+	var maxSum int
+	for _, n := range maxWidths {
+		maxSum += n
+	}
+
+	// Output a table of network traffic per connection.
+	line := make([]byte, 0, maxSum+len(" ")+len(" -> ")+4*len("  "))
+	line = appendRepeatByte(line, '=', cap(line))
+	fmt.Println(string(line))
+	if !msg.Logtail.ID.IsZero() {
+		fmt.Printf("LogID:  %s\n", msg.Logtail.ID)
+	}
+	if msg.NodeID != "" {
+		fmt.Printf("NodeID: %s\n", msg.NodeID)
+	}
+	formatTime := func(t time.Time) string {
+		return t.In(time.Local).Format("2006-01-02 15:04:05.000")
+	}
+	switch {
+	case !msg.Logged.IsZero():
+		fmt.Printf("Logged: %s\n", formatTime(msg.Logged))
+	case !msg.Logtail.Logged.IsZero():
+		fmt.Printf("Logged: %s\n", formatTime(msg.Logtail.Logged))
+	}
+	fmt.Printf("Window: %s (%0.3fs)\n", formatTime(msg.Start), duration.Seconds())
+	for i, row := range rows {
+		line = line[:0]
+		isHeading := !strings.HasPrefix(row[0], " ")
+		for j, col := range row {
+			if isHeading && j == 0 {
+				col = "" // headings will be printed later
+			}
+			switch j {
+			case 0, 2: // left justified
+				line = append(line, col...)
+				line = appendRepeatByte(line, ' ', maxWidths[j]-len(col))
+			case 1, 3, 4, 5, 6: // right justified
+				line = appendRepeatByte(line, ' ', maxWidths[j]-len(col))
+				line = append(line, col...)
+			}
+			switch j {
+			case 0:
+				line = append(line, " "...)
+			case 1:
+				if row[1] == "" && row[2] == "" {
+					line = append(line, "    "...)
+				} else {
+					line = append(line, " -> "...)
+				}
+			case 2, 3, 4, 5:
+				line = append(line, "  "...)
+			}
+		}
+		switch {
+		case i == 0: // print dashed-line table heading
+			line = appendRepeatByte(line[:0], '-', maxWidths[0]+len(" ")+maxWidths[1]+len(" -> ")+maxWidths[2])[:cap(line)]
+		case isHeading:
+			copy(line[:], row[0])
+		}
+		fmt.Println(string(line))
+	}
+}
+
+func mustMakeNamesByAddr() map[netip.Addr]string {
+	switch {
+	case *apiKey == "":
+		log.Fatalf("--api-key must be specified with --resolve-names")
+	case *tailnetName == "":
+		log.Fatalf("--tailnet must be specified with --resolve-names")
+	}
+
+	// Query the Tailscale API for a list of devices in the tailnet.
+	const apiURL = "https://api.tailscale.com/api/v2"
+	req := must.Get(http.NewRequest("GET", apiURL+"/tailnet/"+*tailnetName+"/devices", nil))
+	req.Header.Add("Authorization", "Basic "+base64.StdEncoding.EncodeToString([]byte(*apiKey+":")))
+	resp := must.Get(http.DefaultClient.Do(req))
+	defer resp.Body.Close()
+	b := must.Get(io.ReadAll(resp.Body))
+	if resp.StatusCode != 200 {
+		log.Fatalf("http: %v: %s", http.StatusText(resp.StatusCode), b)
+	}
+
+	// Unmarshal the API response.
+	var m struct {
+		Devices []struct {
+			Name  string       `json:"name"`
+			Addrs []netip.Addr `json:"addresses"`
+		} `json:"devices"`
+	}
+	must.Do(json.Unmarshal(b, &m))
+
+	// Construct a unique mapping of Tailscale IP addresses to hostnames.
+	// For brevity, we start with the first segment of the name and
+	// use more segments until we find the shortest prefix that is unique
+	// for all names in the tailnet.
+	seen := make(map[string]bool)
+	namesByAddr := make(map[netip.Addr]string)
+retry:
+	for i := 0; i < 10; i++ {
+		maps.Clear(seen)
+		maps.Clear(namesByAddr)
+		for _, d := range m.Devices {
+			name := fieldPrefix(d.Name, i)
+			if seen[name] {
+				continue retry
+			}
+			seen[name] = true
+			for _, a := range d.Addrs {
+				namesByAddr[a] = name
+			}
+		}
+		return namesByAddr
+	}
+	panic("unable to produce unique mapping of address to names")
+}
+
+// fieldPrefix returns the first n number of dot-separated segments.
+//
+// Example:
+//
+//	fieldPrefix("foo.bar.baz", 0) returns ""
+//	fieldPrefix("foo.bar.baz", 1) returns "foo"
+//	fieldPrefix("foo.bar.baz", 2) returns "foo.bar"
+//	fieldPrefix("foo.bar.baz", 3) returns "foo.bar.baz"
+//	fieldPrefix("foo.bar.baz", 4) returns "foo.bar.baz"
+func fieldPrefix(s string, n int) string {
+	s0 := s
+	for i := 0; i < n && len(s) > 0; i++ {
+		if j := strings.IndexByte(s, '.'); j >= 0 {
+			s = s[j+1:]
+		} else {
+			s = ""
+		}
+	}
+	return strings.TrimSuffix(s0[:len(s0)-len(s)], ".")
+}
+
+func appendRepeatByte(b []byte, c byte, n int) []byte {
+	for i := 0; i < n; i++ {
+		b = append(b, c)
+	}
+	return b
+}
+
+func formatSI(n float64) string {
+	switch n := math.Abs(n); {
+	case n < 1e3:
+		return fmt.Sprintf("%0.2f ", n/(1e0))
+	case n < 1e6:
+		return fmt.Sprintf("%0.2fk", n/(1e3))
+	case n < 1e9:
+		return fmt.Sprintf("%0.2fM", n/(1e6))
+	default:
+		return fmt.Sprintf("%0.2fG", n/(1e9))
+	}
+}
+
+func formatIEC(n float64) string {
+	switch n := math.Abs(n); {
+	case n < 1<<10:
+		return fmt.Sprintf("%0.2f  ", n/(1<<0))
+	case n < 1<<20:
+		return fmt.Sprintf("%0.2fKi", n/(1<<10))
+	case n < 1<<30:
+		return fmt.Sprintf("%0.2fMi", n/(1<<20))
+	default:
+		return fmt.Sprintf("%0.2fGi", n/(1<<30))
+	}
+}

cmd/nginx-auth/.gitignore

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

cmd/nginx-auth/README.md

@@ -0,0 +1,161 @@
+# nginx-auth
+
+[![status: experimental](https://img.shields.io/badge/status-experimental-blue)](https://tailscale.com/kb/1167/release-stages/#experimental)
+
+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 "tailnet012345.ts.net";
+}
+```
+
+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>
+```
+
+You can get the tailnet name from [the admin panel](https://login.tailscale.com/admin/dns).
+
+## 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=0.1.2
+
+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 +1,128 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//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