net/dns/resolver: wrap errors with more context

To aid in debugging why we're seeing DNS resolution errors.

Updates #TODO

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I9b3f438d5d675f757e9043dbbdc413fd722fb81a

.github/workflows/go-licenses.yml

@@ -1,64 +0,0 @@
-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:
-  update-licenses:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Check out code
-        uses: actions/checkout@v4
-
-      - name: Set up Go
-        uses: actions/setup-go@v4
-        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@b62528385c34dbc9f38e5f4225ac829252d1ea92 # v1.8.0
-        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@284f54f989303d2699d373481a0cfa13ad5a6666 #v5.0.1
-        with:
-          token: ${{ steps.generate-token.outputs.token }}
-          author: License Updater <noreply+license-updater@tailscale.com>
-          committer: License Updater <noreply+license-updater@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/test.yml

@@ -254,9 +254,6 @@ jobs:
             goarch: amd64
           - goos: openbsd
             goarch: amd64
-          # Plan9 (disabled until 3p dependencies are fixed)
-          # - goos: plan9
-          #   goarch: amd64
 
     runs-on: ubuntu-22.04
     steps:
@@ -305,6 +302,47 @@ jobs:
         GOOS: ios
         GOARCH: arm64
 
+  crossmin: # cross-compile for platforms where we only check cmd/tailscale{,d}
+    strategy:
+      fail-fast: false # don't abort the entire matrix if one element fails
+      matrix:
+        include:
+          # Plan9
+          - goos: plan9
+            goarch: amd64
+          # AIX
+          - goos: aix
+            goarch: ppc64
+
+    runs-on: ubuntu-22.04
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: Restore Cache
+      uses: actions/cache@v3
+      with:
+        # Note: unlike the 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: |
+          ~/.cache/go-build
+          ~/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).
+        key: ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
+        restore-keys: |
+          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}
+          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-
+    - name: build core
+      run: ./tool/go build ./cmd/tailscale ./cmd/tailscaled
+      env:
+        GOOS: ${{ matrix.goos }}
+        GOARCH: ${{ matrix.goarch }}
+        GOARM: ${{ matrix.goarm }}
+        CGO_ENABLED: "0"
+
   android:
     # similar to cross above, but android fails to build a few pieces of the
     # repo. We should fix those pieces, they're small, but as a stepping stone,

Makefile

@@ -1,5 +1,5 @@
 IMAGE_REPO ?= tailscale/tailscale
-SYNO_ARCH ?= "amd64"
+SYNO_ARCH ?= "x86_64"
 SYNO_DSM ?= "7"
 TAGS ?= "latest"
 

VERSION.txt

@@ -1 +1 @@
-1.63.0
+1.65.0

client/tailscale/apitype/apitype.go

@@ -49,3 +49,11 @@ type ReloadConfigResponse struct {
 	Reloaded bool   // whether the config was reloaded
 	Err      string // any error message
 }
+
+// ExitNodeSuggestionResponse is the response to a LocalAPI suggest-exit-node GET request.
+// It returns the StableNodeID, name, and location of a suggested exit node for the client making the request.
+type ExitNodeSuggestionResponse struct {
+	ID       tailcfg.StableNodeID
+	Name     string
+	Location tailcfg.LocationView `json:",omitempty"`
+}

client/tailscale/localclient.go

@@ -28,6 +28,7 @@ import (
 
 	"go4.org/mem"
 	"tailscale.com/client/tailscale/apitype"
+	"tailscale.com/drive"
 	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
@@ -35,7 +36,6 @@ import (
 	"tailscale.com/paths"
 	"tailscale.com/safesocket"
 	"tailscale.com/tailcfg"
-	"tailscale.com/tailfs"
 	"tailscale.com/tka"
 	"tailscale.com/types/key"
 	"tailscale.com/types/tkatype"
@@ -1418,53 +1418,62 @@ func (lc *LocalClient) CheckUpdate(ctx context.Context) (*tailcfg.ClientVersion,
 	return &cv, nil
 }
 
-// TailFSSetFileServerAddr instructs TailFS to use the server at addr to access
+// SetUseExitNode toggles the use of an exit node on or off.
+// To turn it on, there must have been a previously used exit node.
+// The most previously used one is reused.
+// This is a convenience method for GUIs. To select an actual one, update the prefs.
+func (lc *LocalClient) SetUseExitNode(ctx context.Context, on bool) error {
+	_, err := lc.send(ctx, "POST", "/localapi/v0/set-use-exit-node-enabled?enabled="+strconv.FormatBool(on), http.StatusOK, nil)
+	return err
+}
+
+// DriveSetServerAddr instructs Taildrive to use the server at addr to access
 // the filesystem. This is used on platforms like Windows and MacOS to let
-// TailFS know to use the file server running in the GUI app.
-func (lc *LocalClient) TailFSSetFileServerAddr(ctx context.Context, addr string) error {
-	_, err := lc.send(ctx, "PUT", "/localapi/v0/tailfs/fileserver-address", http.StatusCreated, strings.NewReader(addr))
+// Taildrive know to use the file server running in the GUI app.
+func (lc *LocalClient) DriveSetServerAddr(ctx context.Context, addr string) error {
+	_, err := lc.send(ctx, "PUT", "/localapi/v0/drive/fileserver-address", http.StatusCreated, strings.NewReader(addr))
 	return err
 }
 
-// TailFSShareSet adds or updates the given share in the list of shares that
-// TailFS will serve to remote nodes. If a share with the same name already
+// DriveShareSet adds or updates the given share in the list of shares that
+// Taildrive will serve to remote nodes. If a share with the same name already
 // exists, the existing share is replaced/updated.
-func (lc *LocalClient) TailFSShareSet(ctx context.Context, share *tailfs.Share) error {
-	_, err := lc.send(ctx, "PUT", "/localapi/v0/tailfs/shares", http.StatusCreated, jsonBody(share))
+func (lc *LocalClient) DriveShareSet(ctx context.Context, share *drive.Share) error {
+	_, err := lc.send(ctx, "PUT", "/localapi/v0/drive/shares", http.StatusCreated, jsonBody(share))
 	return err
 }
 
-// TailFSShareRemove removes the share with the given name from the list of
-// shares that TailFS will serve to remote nodes.
-func (lc *LocalClient) TailFSShareRemove(ctx context.Context, name string) error {
+// DriveShareRemove removes the share with the given name from the list of
+// shares that Taildrive will serve to remote nodes.
+func (lc *LocalClient) DriveShareRemove(ctx context.Context, name string) error {
 	_, err := lc.send(
 		ctx,
 		"DELETE",
-		"/localapi/v0/tailfs/shares",
+		"/localapi/v0/drive/shares",
 		http.StatusNoContent,
 		strings.NewReader(name))
 	return err
 }
 
-// TailFSShareRename renames the share from old to new name.
-func (lc *LocalClient) TailFSShareRename(ctx context.Context, oldName, newName string) error {
+// DriveShareRename renames the share from old to new name.
+func (lc *LocalClient) DriveShareRename(ctx context.Context, oldName, newName string) error {
 	_, err := lc.send(
 		ctx,
 		"POST",
-		"/localapi/v0/tailfs/shares",
+		"/localapi/v0/drive/shares",
 		http.StatusNoContent,
 		jsonBody([2]string{oldName, newName}))
 	return err
 }
 
-// TailFSShareList returns the list of shares that TailFS is currently serving
+// DriveShareList returns the list of shares that drive is currently serving
 // to remote nodes.
-func (lc *LocalClient) TailFSShareList(ctx context.Context) ([]*tailfs.Share, error) {
-	result, err := lc.get200(ctx, "/localapi/v0/tailfs/shares")
+func (lc *LocalClient) DriveShareList(ctx context.Context) ([]*drive.Share, error) {
+	result, err := lc.get200(ctx, "/localapi/v0/drive/shares")
 	if err != nil {
 		return nil, err
 	}
-	var shares []*tailfs.Share
+	var shares []*drive.Share
 	err = json.Unmarshal(result, &shares)
 	return shares, err
 }
@@ -1505,3 +1514,12 @@ func (w *IPNBusWatcher) Next() (ipn.Notify, error) {
 	}
 	return n, nil
 }
+
+// SuggestExitNode requests an exit node suggestion and returns the exit node's details.
+func (lc *LocalClient) SuggestExitNode(ctx context.Context) (apitype.ExitNodeSuggestionResponse, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/suggest-exit-node")
+	if err != nil {
+		return apitype.ExitNodeSuggestionResponse{}, err
+	}
+	return decodeJSON[apitype.ExitNodeSuggestionResponse](body)
+}

client/tailscale/localclient_test.go

@@ -34,9 +34,9 @@ func TestDeps(t *testing.T) {
 	deptest.DepChecker{
 		BadDeps: map[string]string{
 			// Make sure we don't again accidentally bring in a dependency on
-			// TailFS or its transitive dependencies
-			"tailscale.com/tailfs/tailfsimpl": "https://github.com/tailscale/tailscale/pull/10631",
-			"github.com/studio-b12/gowebdav":  "https://github.com/tailscale/tailscale/pull/10631",
+			// drive or its transitive dependencies
+			"tailscale.com/drive/driveimpl":  "https://github.com/tailscale/tailscale/pull/10631",
+			"github.com/studio-b12/gowebdav": "https://github.com/tailscale/tailscale/pull/10631",
 		},
 	}.Check(t)
 }

client/web/auth.go

@@ -223,7 +223,7 @@ func (s *Server) awaitUserAuth(ctx context.Context, session *browserSession) err
 
 func (s *Server) newSessionID() (string, error) {
 	raw := make([]byte, 16)
-	for i := 0; i < 5; i++ {
+	for range 5 {
 		if _, err := rand.Read(raw); err != nil {
 			return "", err
 		}

clientupdate/clientupdate.go

@@ -436,7 +436,7 @@ func (up *Updater) updateDebLike() error {
 		return fmt.Errorf("apt-get update failed: %w; output:\n%s", err, out)
 	}
 
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		out, err := exec.Command("apt-get", "install", "--yes", "--allow-downgrades", "tailscale="+ver).CombinedOutput()
 		if err != nil {
 			if !bytes.Contains(out, []byte(`dpkg was interrupted`)) {

clientupdate/clientupdate_test.go

@@ -663,7 +663,7 @@ func genTarball(t *testing.T, path string, files map[string]string) {
 
 func TestWriteFileOverwrite(t *testing.T) {
 	path := filepath.Join(t.TempDir(), "test")
-	for i := 0; i < 2; i++ {
+	for i := range 2 {
 		content := fmt.Sprintf("content %d", i)
 		if err := writeFile(strings.NewReader(content), path, 0600); err != nil {
 			t.Fatal(err)

clientupdate/distsign/distsign_test.go

@@ -445,7 +445,7 @@ type testServer struct {
 
 func newTestServer(t *testing.T) *testServer {
 	var roots []rootKeyPair
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		roots = append(roots, newRootKeyPair(t))
 	}
 

clientupdate/systemd_linux.go

@@ -19,11 +19,11 @@ func restartSystemdUnit(ctx context.Context) error {
 	}
 	defer c.Close()
 	if err := c.ReloadContext(ctx); err != nil {
-		return fmt.Errorf("failed to reload tailsacled.service: %w", err)
+		return fmt.Errorf("failed to reload tailscaled.service: %w", err)
 	}
 	ch := make(chan string, 1)
 	if _, err := c.RestartUnitContext(ctx, "tailscaled.service", "replace", ch); err != nil {
-		return fmt.Errorf("failed to restart tailsacled.service: %w", err)
+		return fmt.Errorf("failed to restart tailscaled.service: %w", err)
 	}
 	select {
 	case res := <-ch:

cmd/cloner/cloner.go

@@ -102,7 +102,7 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
 	writef("}")
 	writef("dst := new(%s)", name)
 	writef("*dst = *src")
-	for i := 0; i < t.NumFields(); i++ {
+	for i := range t.NumFields() {
 		fname := t.Field(i).Name()
 		ft := t.Field(i).Type()
 		if !codegen.ContainsPointers(ft) || codegen.HasNoClone(t.Tag(i)) {

cmd/derper/depaware.txt

@@ -17,7 +17,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
    L    github.com/google/nftables/expr                              from github.com/google/nftables+
    L    github.com/google/nftables/internal/parseexprfunc            from github.com/google/nftables+
    L    github.com/google/nftables/xt                                from github.com/google/nftables/expr+
-        github.com/google/uuid                                       from tailscale.com/tsweb
+        github.com/google/uuid                                       from tailscale.com/util/fastuuid
         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+
@@ -86,6 +86,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         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/drive                                          from tailscale.com/client/tailscale+
         tailscale.com/envknob                                        from tailscale.com/client/tailscale+
         tailscale.com/health                                         from tailscale.com/net/tlsdial
         tailscale.com/hostinfo                                       from tailscale.com/net/interfaces+
@@ -114,7 +115,6 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
      💣 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/tailfs                                         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                                         from tailscale.com/derp+
@@ -143,6 +143,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/util/ctxkey                                    from tailscale.com/tsweb+
    L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
         tailscale.com/util/dnsname                                   from tailscale.com/hostinfo+
+        tailscale.com/util/fastuuid                                  from tailscale.com/tsweb
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale
         tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
    L    tailscale.com/util/linuxfw                                   from tailscale.com/net/netns
@@ -250,6 +251,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         math/big                                                     from crypto/dsa+
         math/bits                                                    from compress/flate+
         math/rand                                                    from github.com/mdlayher/netlink+
+        math/rand/v2                                                 from tailscale.com/util/fastuuid
         mime                                                         from github.com/prometheus/common/expfmt+
         mime/multipart                                               from net/http
         mime/quotedprintable                                         from mime/multipart

cmd/derper/derper.go

@@ -36,19 +36,21 @@ import (
 	"tailscale.com/tsweb"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
+	"tailscale.com/version"
 )
 
 var (
-	dev        = flag.Bool("dev", false, "run in localhost development mode (overrides -a)")
-	addr       = flag.String("a", ":443", "server HTTP/HTTPS listen address, in form \":port\", \"ip:port\", or for IPv6 \"[ip]:port\". If the IP is omitted, it defaults to all interfaces. Serves HTTPS if the port is 443 and/or -certmode is manual, otherwise HTTP.")
-	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.")
+	dev         = flag.Bool("dev", false, "run in localhost development mode (overrides -a)")
+	versionFlag = flag.Bool("version", false, "print version and exit")
+	addr        = flag.String("a", ":443", "server HTTP/HTTPS listen address, in form \":port\", \"ip:port\", or for IPv6 \"[ip]:port\". If the IP is omitted, it defaults to all interfaces. Serves HTTPS if the port is 443 and/or -certmode is manual, otherwise HTTP.")
+	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")
@@ -129,6 +131,10 @@ func writeNewConfig() config {
 
 func main() {
 	flag.Parse()
+	if *versionFlag {
+		fmt.Println(version.Long())
+		return
+	}
 
 	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer cancel()

cmd/derpprobe/derpprobe.go

@@ -16,10 +16,12 @@ import (
 
 	"tailscale.com/prober"
 	"tailscale.com/tsweb"
+	"tailscale.com/version"
 )
 
 var (
 	derpMapURL   = flag.String("derp-map", "https://login.tailscale.com/derpmap/default", "URL to DERP map (https:// or file://)")
+	versionFlag  = flag.Bool("version", false, "print version and exit")
 	listen       = flag.String("listen", ":8030", "HTTP listen address")
 	probeOnce    = flag.Bool("once", false, "probe once and print results, then exit; ignores the listen flag")
 	spread       = flag.Bool("spread", true, "whether to spread probing over time")
@@ -33,6 +35,10 @@ var (
 
 func main() {
 	flag.Parse()
+	if *versionFlag {
+		fmt.Println(version.Long())
+		return
+	}
 
 	p := prober.New().WithSpread(*spread).WithOnce(*probeOnce).WithMetricNamespace("derpprobe")
 	opts := []prober.DERPOpt{

cmd/k8s-operator/deploy/crds/tailscale.com_connectors.yaml

@@ -31,6 +31,7 @@ spec:
       name: v1alpha1
       schema:
         openAPIV3Schema:
+          description: 'Connector defines a Tailscale node that will be deployed in the cluster. The node can be configured to act as a Tailscale subnet router and/or a Tailscale exit node. Connector is a cluster-scoped resource. More info: https://tailscale.com/kb/1236/kubernetes-operator#deploying-exit-nodes-and-subnet-routers-on-kubernetes-using-connector-custom-resource'
           type: object
           required:
             - spec
@@ -44,7 +45,7 @@ spec:
             metadata:
               type: object
             spec:
-              description: ConnectorSpec describes the desired Tailscale component.
+              description: 'ConnectorSpec describes the desired Tailscale component. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status'
               type: object
               properties:
                 exitNode:

cmd/k8s-operator/deploy/crds/tailscale.com_proxyclasses.yaml

@@ -21,6 +21,7 @@ spec:
       name: v1alpha1
       schema:
         openAPIV3Schema:
+          description: 'ProxyClass describes a set of configuration parameters that can be applied to proxy resources created by the Tailscale Kubernetes operator. To apply a given ProxyClass to resources created for a tailscale Ingress or Service, use tailscale.com/proxy-class=<proxyclass-name> label. To apply a given ProxyClass to resources created for a Connector, use connector.spec.proxyClass field. ProxyClass is a cluster scoped resource. More info: https://tailscale.com/kb/1236/kubernetes-operator#cluster-resource-customization-using-proxyclass-custom-resource.'
           type: object
           required:
             - spec
@@ -34,12 +35,13 @@ spec:
             metadata:
               type: object
             spec:
+              description: Specification of the desired state of the ProxyClass resource. https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
               type: object
               required:
                 - statefulSet
               properties:
                 statefulSet:
-                  description: Proxy's StatefulSet spec.
+                  description: Configuration parameters for the proxy's StatefulSet. Tailscale Kubernetes operator deploys a StatefulSet for each of the user configured proxies (Tailscale Ingress, Tailscale Service, Connector).
                   type: object
                   properties:
                     annotations:
@@ -177,6 +179,21 @@ spec:
                           description: Configuration for the proxy container running tailscale.
                           type: object
                           properties:
+                            env:
+                              description: List of environment variables to set in the container. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#environment-variables Note that environment variables provided here will take precedence over Tailscale-specific environment variables set by the operator, however running proxies with custom values for Tailscale environment variables (i.e TS_USERSPACE) is not recommended and might break in the future.
+                              type: array
+                              items:
+                                type: object
+                                required:
+                                  - name
+                                properties:
+                                  name:
+                                    description: Name of the environment variable. Must be a C_IDENTIFIER.
+                                    type: string
+                                    pattern: ^[-._a-zA-Z][-._a-zA-Z0-9]*$
+                                  value:
+                                    description: 'Variable references $(VAR_NAME) are expanded using the previously defined environment variables in the container and any service environment variables. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Defaults to "".'
+                                    type: string
                             resources:
                               description: Container resource requirements. By default Tailscale Kubernetes operator does not apply any resource requirements. The amount of resources required wil depend on the amount of resources the operator needs to parse, usage patterns and cluster size. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#resources
                               type: object
@@ -305,6 +322,21 @@ spec:
                           description: Configuration for the proxy init container that enables forwarding.
                           type: object
                           properties:
+                            env:
+                              description: List of environment variables to set in the container. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#environment-variables Note that environment variables provided here will take precedence over Tailscale-specific environment variables set by the operator, however running proxies with custom values for Tailscale environment variables (i.e TS_USERSPACE) is not recommended and might break in the future.
+                              type: array
+                              items:
+                                type: object
+                                required:
+                                  - name
+                                properties:
+                                  name:
+                                    description: Name of the environment variable. Must be a C_IDENTIFIER.
+                                    type: string
+                                    pattern: ^[-._a-zA-Z][-._a-zA-Z0-9]*$
+                                  value:
+                                    description: 'Variable references $(VAR_NAME) are expanded using the previously defined environment variables in the container and any service environment variables. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Defaults to "".'
+                                    type: string
                             resources:
                               description: Container resource requirements. By default Tailscale Kubernetes operator does not apply any resource requirements. The amount of resources required wil depend on the amount of resources the operator needs to parse, usage patterns and cluster size. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#resources
                               type: object
@@ -453,6 +485,7 @@ spec:
                                 description: Value is the taint value the toleration matches to. If the operator is Exists, the value should be empty, otherwise just a regular string.
                                 type: string
             status:
+              description: Status of the ProxyClass. This is set and managed automatically. https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
               type: object
               properties:
                 conditions:

cmd/k8s-operator/deploy/manifests/operator.yaml

@@ -60,6 +60,7 @@ spec:
           name: v1alpha1
           schema:
             openAPIV3Schema:
+                description: 'Connector defines a Tailscale node that will be deployed in the cluster. The node can be configured to act as a Tailscale subnet router and/or a Tailscale exit node. Connector is a cluster-scoped resource. More info: https://tailscale.com/kb/1236/kubernetes-operator#deploying-exit-nodes-and-subnet-routers-on-kubernetes-using-connector-custom-resource'
                 properties:
                     apiVersion:
                         description: 'APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
@@ -70,7 +71,7 @@ spec:
                     metadata:
                         type: object
                     spec:
-                        description: ConnectorSpec describes the desired Tailscale component.
+                        description: 'ConnectorSpec describes the desired Tailscale component. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status'
                         properties:
                             exitNode:
                                 description: ExitNode defines whether the Connector node should act as a Tailscale exit node. Defaults to false. https://tailscale.com/kb/1103/exit-nodes
@@ -179,6 +180,7 @@ spec:
           name: v1alpha1
           schema:
             openAPIV3Schema:
+                description: 'ProxyClass describes a set of configuration parameters that can be applied to proxy resources created by the Tailscale Kubernetes operator. To apply a given ProxyClass to resources created for a tailscale Ingress or Service, use tailscale.com/proxy-class=<proxyclass-name> label. To apply a given ProxyClass to resources created for a Connector, use connector.spec.proxyClass field. ProxyClass is a cluster scoped resource. More info: https://tailscale.com/kb/1236/kubernetes-operator#cluster-resource-customization-using-proxyclass-custom-resource.'
                 properties:
                     apiVersion:
                         description: 'APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
@@ -189,9 +191,10 @@ spec:
                     metadata:
                         type: object
                     spec:
+                        description: Specification of the desired state of the ProxyClass resource. https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
                         properties:
                             statefulSet:
-                                description: Proxy's StatefulSet spec.
+                                description: Configuration parameters for the proxy's StatefulSet. Tailscale Kubernetes operator deploys a StatefulSet for each of the user configured proxies (Tailscale Ingress, Tailscale Service, Connector).
                                 properties:
                                     annotations:
                                         additionalProperties:
@@ -326,6 +329,21 @@ spec:
                                             tailscaleContainer:
                                                 description: Configuration for the proxy container running tailscale.
                                                 properties:
+                                                    env:
+                                                        description: List of environment variables to set in the container. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#environment-variables Note that environment variables provided here will take precedence over Tailscale-specific environment variables set by the operator, however running proxies with custom values for Tailscale environment variables (i.e TS_USERSPACE) is not recommended and might break in the future.
+                                                        items:
+                                                            properties:
+                                                                name:
+                                                                    description: Name of the environment variable. Must be a C_IDENTIFIER.
+                                                                    pattern: ^[-._a-zA-Z][-._a-zA-Z0-9]*$
+                                                                    type: string
+                                                                value:
+                                                                    description: 'Variable references $(VAR_NAME) are expanded using the previously defined environment variables in the container and any service environment variables. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Defaults to "".'
+                                                                    type: string
+                                                            required:
+                                                                - name
+                                                            type: object
+                                                        type: array
                                                     resources:
                                                         description: Container resource requirements. By default Tailscale Kubernetes operator does not apply any resource requirements. The amount of resources required wil depend on the amount of resources the operator needs to parse, usage patterns and cluster size. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#resources
                                                         properties:
@@ -454,6 +472,21 @@ spec:
                                             tailscaleInitContainer:
                                                 description: Configuration for the proxy init container that enables forwarding.
                                                 properties:
+                                                    env:
+                                                        description: List of environment variables to set in the container. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#environment-variables Note that environment variables provided here will take precedence over Tailscale-specific environment variables set by the operator, however running proxies with custom values for Tailscale environment variables (i.e TS_USERSPACE) is not recommended and might break in the future.
+                                                        items:
+                                                            properties:
+                                                                name:
+                                                                    description: Name of the environment variable. Must be a C_IDENTIFIER.
+                                                                    pattern: ^[-._a-zA-Z][-._a-zA-Z0-9]*$
+                                                                    type: string
+                                                                value:
+                                                                    description: 'Variable references $(VAR_NAME) are expanded using the previously defined environment variables in the container and any service environment variables. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Defaults to "".'
+                                                                    type: string
+                                                            required:
+                                                                - name
+                                                            type: object
+                                                        type: array
                                                     resources:
                                                         description: Container resource requirements. By default Tailscale Kubernetes operator does not apply any resource requirements. The amount of resources required wil depend on the amount of resources the operator needs to parse, usage patterns and cluster size. https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#resources
                                                         properties:
@@ -608,6 +641,7 @@ spec:
                             - statefulSet
                         type: object
                     status:
+                        description: Status of the ProxyClass. This is set and managed automatically. https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
                         properties:
                             conditions:
                                 description: List of status conditions to indicate the status of the ProxyClass. Known condition types are `ProxyClassReady`.

cmd/k8s-operator/proxyclass.go

@@ -10,6 +10,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"go.uber.org/zap"
 	corev1 "k8s.io/api/core/v1"
@@ -30,7 +31,9 @@ import (
 const (
 	reasonProxyClassInvalid  = "ProxyClassInvalid"
 	reasonProxyClassValid    = "ProxyClassValid"
+	reasonCustomTSEnvVar     = "CustomTSEnvVar"
 	messageProxyClassInvalid = "ProxyClass is not valid: %v"
+	messageCustomTSEnvVar    = "ProxyClass overrides the default value for %s env var for %s container. Running with custom values for Tailscale env vars is not recommended and might break in the future."
 )
 
 type ProxyClassReconciler struct {
@@ -98,6 +101,19 @@ func (a *ProxyClassReconciler) validate(pc *tsapi.ProxyClass) (violations field.
 					violations = append(violations, errs...)
 				}
 			}
+			if tc := pod.TailscaleContainer; tc != nil {
+				for _, e := range tc.Env {
+					if strings.HasPrefix(string(e.Name), "TS_") {
+						a.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
+					}
+					if strings.EqualFold(string(e.Name), "EXPERIMENTAL_TS_CONFIGFILE_PATH") {
+						a.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
+					}
+					if strings.EqualFold(string(e.Name), "EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS") {
+						a.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
+					}
+				}
+			}
 		}
 	}
 	// We do not validate embedded fields (security context, resource

cmd/k8s-operator/proxyclass_test.go

@@ -36,8 +36,9 @@ func TestProxyClass(t *testing.T) {
 				Labels:      map[string]string{"foo": "bar", "xyz1234": "abc567"},
 				Annotations: map[string]string{"foo.io/bar": "{'key': 'val1232'}"},
 				Pod: &tsapi.Pod{
-					Labels:      map[string]string{"foo": "bar", "xyz1234": "abc567"},
-					Annotations: map[string]string{"foo.io/bar": "{'key': 'val1232'}"},
+					Labels:             map[string]string{"foo": "bar", "xyz1234": "abc567"},
+					Annotations:        map[string]string{"foo.io/bar": "{'key': 'val1232'}"},
+					TailscaleContainer: &tsapi.Container{Env: []tsapi.Env{{Name: "FOO", Value: "BAR"}}},
 				},
 			},
 		},
@@ -51,16 +52,17 @@ func TestProxyClass(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	fr := record.NewFakeRecorder(3) // bump this if you expect a test case to throw more events
 	cl := tstest.NewClock(tstest.ClockOpts{})
 	pcr := &ProxyClassReconciler{
 		Client:   fc,
 		logger:   zl.Sugar(),
 		clock:    cl,
-		recorder: record.NewFakeRecorder(1),
+		recorder: fr,
 	}
-	expectReconciled(t, pcr, "", "test")
 
 	// 1. A valid ProxyClass resource gets its status updated to Ready.
+	expectReconciled(t, pcr, "", "test")
 	pc.Status.Conditions = append(pc.Status.Conditions, tsapi.ConnectorCondition{
 		Type:               tsapi.ProxyClassready,
 		Status:             metav1.ConditionTrue,
@@ -80,4 +82,17 @@ func TestProxyClass(t *testing.T) {
 	msg := `ProxyClass is not valid: .spec.statefulSet.labels: Invalid value: "?!someVal": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?')`
 	tsoperator.SetProxyClassCondition(pc, tsapi.ProxyClassready, metav1.ConditionFalse, reasonProxyClassInvalid, msg, 0, cl, zl.Sugar())
 	expectEqual(t, fc, pc, nil)
+	expectedEvent := "Warning ProxyClassInvalid ProxyClass is not valid: .spec.statefulSet.labels: Invalid value: \"?!someVal\": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?')"
+	expectEvents(t, fr, []string{expectedEvent})
+
+	// 2. An valid ProxyClass but with a Tailscale env vars set results in warning events.
+	mustUpdate(t, fc, "", "test", func(proxyClass *tsapi.ProxyClass) {
+		proxyClass.Spec.StatefulSet.Labels = nil // unset invalid labels from the previous test
+		proxyClass.Spec.StatefulSet.Pod.TailscaleContainer.Env = []tsapi.Env{{Name: "TS_USERSPACE", Value: "true"}, {Name: "EXPERIMENTAL_TS_CONFIGFILE_PATH"}, {Name: "EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS"}}
+	})
+	expectedEvents := []string{"Warning CustomTSEnvVar ProxyClass overrides the default value for TS_USERSPACE env var for tailscale container. Running with custom values for Tailscale env vars is not recommended and might break in the future.",
+		"Warning CustomTSEnvVar ProxyClass overrides the default value for EXPERIMENTAL_TS_CONFIGFILE_PATH env var for tailscale container. Running with custom values for Tailscale env vars is not recommended and might break in the future.",
+		"Warning CustomTSEnvVar ProxyClass overrides the default value for EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS env var for tailscale container. Running with custom values for Tailscale env vars is not recommended and might break in the future."}
+	expectReconciled(t, pcr, "", "test")
+	expectEvents(t, fr, expectedEvents)
 }

cmd/k8s-operator/sts.go

@@ -644,6 +644,15 @@ func applyProxyClassToStatefulSet(pc *tsapi.ProxyClass, ss *appsv1.StatefulSet)
 			base.SecurityContext = overlay.SecurityContext
 		}
 		base.Resources = overlay.Resources
+		for _, e := range overlay.Env {
+			// Env vars configured via ProxyClass might override env
+			// vars that have been specified by the operator, i.e
+			// TS_USERSPACE. The intended behaviour is to allow this
+			// and in practice it works without explicitly removing
+			// the operator configured value here as a later value
+			// in the env var list overrides an earlier one.
+			base.Env = append(base.Env, corev1.EnvVar{Name: string(e.Name), Value: e.Value})
+		}
 		return base
 	}
 	for i, c := range ss.Spec.Template.Spec.Containers {

cmd/k8s-operator/sts_test.go

@@ -75,6 +75,7 @@ func Test_applyProxyClassToStatefulSet(t *testing.T) {
 							Limits:   corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("1000m"), corev1.ResourceMemory: resource.MustParse("128Mi")},
 							Requests: corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("500m"), corev1.ResourceMemory: resource.MustParse("64Mi")},
 						},
+						Env: []tsapi.Env{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}},
 					},
 					TailscaleInitContainer: &tsapi.Container{
 						SecurityContext: &corev1.SecurityContext{
@@ -85,6 +86,7 @@ func Test_applyProxyClassToStatefulSet(t *testing.T) {
 							Limits:   corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("1000m"), corev1.ResourceMemory: resource.MustParse("128Mi")},
 							Requests: corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("500m"), corev1.ResourceMemory: resource.MustParse("64Mi")},
 						},
+						Env: []tsapi.Env{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}},
 					},
 				},
 			},
@@ -142,6 +144,8 @@ func Test_applyProxyClassToStatefulSet(t *testing.T) {
 	wantSS.Spec.Template.Spec.InitContainers[0].SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleInitContainer.SecurityContext
 	wantSS.Spec.Template.Spec.Containers[0].Resources = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.Resources
 	wantSS.Spec.Template.Spec.InitContainers[0].Resources = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleInitContainer.Resources
+	wantSS.Spec.Template.Spec.InitContainers[0].Env = append(wantSS.Spec.Template.Spec.InitContainers[0].Env, []corev1.EnvVar{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}}...)
+	wantSS.Spec.Template.Spec.Containers[0].Env = append(wantSS.Spec.Template.Spec.Containers[0].Env, []corev1.EnvVar{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}}...)
 
 	gotSS := applyProxyClassToStatefulSet(proxyClassAllOpts, nonUserspaceProxySS.DeepCopy())
 	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
@@ -175,6 +179,7 @@ func Test_applyProxyClassToStatefulSet(t *testing.T) {
 	wantSS.Spec.Template.Spec.Tolerations = proxyClassAllOpts.Spec.StatefulSet.Pod.Tolerations
 	wantSS.Spec.Template.Spec.Containers[0].SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.SecurityContext
 	wantSS.Spec.Template.Spec.Containers[0].Resources = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.Resources
+	wantSS.Spec.Template.Spec.Containers[0].Env = append(wantSS.Spec.Template.Spec.Containers[0].Env, []corev1.EnvVar{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}}...)
 	gotSS = applyProxyClassToStatefulSet(proxyClassAllOpts, userspaceProxySS.DeepCopy())
 	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
 		t.Fatalf("Unexpected result applying ProxyClass with custom labels and annotations to a StatefulSet for a userspace proxy (-got +want):\n%s", diff)

cmd/k8s-operator/testutils_test.go

@@ -20,6 +20,7 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/client-go/tools/record"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 	"tailscale.com/client/tailscale"
@@ -515,6 +516,34 @@ func expectRequeue(t *testing.T, sr reconcile.Reconciler, ns, name string) {
 	}
 }
 
+// expectEvents accepts a test recorder and a list of events, tests that expected
+// events are sent down the recorder's channel. Waits for 5s for each event.
+func expectEvents(t *testing.T, rec *record.FakeRecorder, wantsEvents []string) {
+	t.Helper()
+	// Events are not expected to arrive in order.
+	seenEvents := make([]string, 0)
+	for range len(wantsEvents) {
+		timer := time.NewTimer(time.Second * 5)
+		defer timer.Stop()
+		select {
+		case gotEvent := <-rec.Events:
+			found := false
+			for _, wantEvent := range wantsEvents {
+				if wantEvent == gotEvent {
+					found = true
+					seenEvents = append(seenEvents, gotEvent)
+					break
+				}
+			}
+			if !found {
+				t.Errorf("got unexpected event %q, expected events: %+#v", gotEvent, wantsEvents)
+			}
+		case <-timer.C:
+			t.Errorf("timeout waiting for an event, wants events %#+v, got events %+#v", wantsEvents, seenEvents)
+		}
+	}
+}
+
 type fakeTSClient struct {
 	sync.Mutex
 	keyRequests []tailscale.KeyCapabilities

cmd/netlogfmt/main.go

@@ -314,7 +314,7 @@ func mustMakeNamesByAddr() map[netip.Addr]string {
 	seen := make(map[string]bool)
 	namesByAddr := make(map[netip.Addr]string)
 retry:
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		clear(seen)
 		clear(namesByAddr)
 		for _, d := range m.Devices {
@@ -354,7 +354,7 @@ func fieldPrefix(s string, n int) string {
 }
 
 func appendRepeatByte(b []byte, c byte, n int) []byte {
-	for i := 0; i < n; i++ {
+	for range n {
 		b = append(b, c)
 	}
 	return b

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

@@ -88,7 +88,7 @@ func main() {
 
 		go func() {
 			// wait for tailscale to start before trying to fetch cert names
-			for i := 0; i < 60; i++ {
+			for range 60 {
 				st, err := localClient.Status(context.Background())
 				if err != nil {
 					log.Printf("error retrieving tailscale status; retrying: %v", err)

cmd/sniproxy/sniproxy_test.go

@@ -158,7 +158,7 @@ func TestSNIProxyWithNetmapConfig(t *testing.T) {
 		t.Fatal(err)
 	}
 	gotConfigured := false
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		s, err := l.StatusWithoutPeers(ctx)
 		if err != nil {
 			t.Fatal(err)

cmd/stund/depaware.txt

@@ -2,7 +2,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
 
         github.com/beorn7/perks/quantile                             from github.com/prometheus/client_golang/prometheus
      💣 github.com/cespare/xxhash/v2                                 from github.com/prometheus/client_golang/prometheus
-        github.com/google/uuid                                       from tailscale.com/tsweb
+        github.com/google/uuid                                       from tailscale.com/util/fastuuid
      💣 github.com/prometheus/client_golang/prometheus               from tailscale.com/tsweb/promvarz
         github.com/prometheus/client_golang/prometheus/internal      from github.com/prometheus/client_golang/prometheus
         github.com/prometheus/client_model/go                        from github.com/prometheus/client_golang/prometheus+
@@ -65,6 +65,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
         tailscale.com/util/ctxkey                                    from tailscale.com/tsweb+
    L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
         tailscale.com/util/dnsname                                   from tailscale.com/tailcfg
+        tailscale.com/util/fastuuid                                  from tailscale.com/tsweb
         tailscale.com/util/lineread                                  from tailscale.com/version/distro
         tailscale.com/util/nocasemaps                                from tailscale.com/types/ipproto
         tailscale.com/util/slicesx                                   from tailscale.com/tailcfg
@@ -151,6 +152,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
         math/big                                                     from crypto/dsa+
         math/bits                                                    from compress/flate+
         math/rand                                                    from math/big+
+        math/rand/v2                                                 from tailscale.com/util/fastuuid
         mime                                                         from github.com/prometheus/common/expfmt+
         mime/multipart                                               from net/http
         mime/quotedprintable                                         from mime/multipart

cmd/tailscale/cli/bugreport.go

@@ -17,7 +17,7 @@ var bugReportCmd = &ffcli.Command{
 	Name:       "bugreport",
 	Exec:       runBugReport,
 	ShortHelp:  "Print a shareable identifier to help diagnose issues",
-	ShortUsage: "bugreport [note]",
+	ShortUsage: "tailscale bugreport [note]",
 	FlagSet: (func() *flag.FlagSet {
 		fs := newFlagSet("bugreport")
 		fs.BoolVar(&bugReportArgs.diagnose, "diagnose", false, "run additional in-depth checks")

cmd/tailscale/cli/cert.go

@@ -28,7 +28,7 @@ var certCmd = &ffcli.Command{
 	Name:       "cert",
 	Exec:       runCert,
 	ShortHelp:  "Get TLS certs",
-	ShortUsage: "cert [flags] <domain>",
+	ShortUsage: "tailscale cert [flags] <domain>",
 	FlagSet: (func() *flag.FlagSet {
 		fs := newFlagSet("cert")
 		fs.StringVar(&certArgs.certFile, "cert-file", "", "output cert file or \"-\" for stdout; defaults to DOMAIN.crt if --cert-file and --key-file are both unset")

cmd/tailscale/cli/cli.go

@@ -14,11 +14,12 @@ import (
 	"log"
 	"os"
 	"runtime"
-	"slices"
 	"strings"
 	"sync"
 	"text/tabwriter"
 
+	"github.com/mattn/go-colorable"
+	"github.com/mattn/go-isatty"
 	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/client/tailscale"
 	"tailscale.com/envknob"
@@ -93,6 +94,68 @@ func Run(args []string) (err error) {
 		})
 	})
 
+	rootCmd := newRootCmd()
+	if err := rootCmd.Parse(args); err != nil {
+		if errors.Is(err, flag.ErrHelp) {
+			return nil
+		}
+		if noexec := (ffcli.NoExecError{}); errors.As(err, &noexec) {
+			// When the user enters an unknown subcommand, ffcli tries to run
+			// the closest valid parent subcommand with everything else as args,
+			// returning NoExecError if it doesn't have an Exec function.
+			cmd := noexec.Command
+			args := cmd.FlagSet.Args()
+			if len(cmd.Subcommands) > 0 {
+				if len(args) > 0 {
+					return fmt.Errorf("%s: unknown subcommand: %s", fullCmd(rootCmd, cmd), args[0])
+				}
+				subs := make([]string, 0, len(cmd.Subcommands))
+				for _, sub := range cmd.Subcommands {
+					subs = append(subs, sub.Name)
+				}
+				return fmt.Errorf("%s: missing subcommand: %s", fullCmd(rootCmd, cmd), strings.Join(subs, ", "))
+			}
+		}
+		return err
+	}
+
+	if envknob.Bool("TS_DUMP_HELP") {
+		walkCommands(rootCmd, func(w cmdWalk) bool {
+			fmt.Println("===")
+			// UsageFuncs are typically called during Command.Run which ensures
+			// FlagSet is not nil.
+			c := w.Command
+			if c.FlagSet == nil {
+				c.FlagSet = flag.NewFlagSet(c.Name, flag.ContinueOnError)
+			}
+			if c.UsageFunc != nil {
+				fmt.Println(c.UsageFunc(c))
+			} else {
+				fmt.Println(ffcli.DefaultUsageFunc(c))
+			}
+			return true
+		})
+		return
+	}
+
+	localClient.Socket = rootArgs.socket
+	rootCmd.FlagSet.Visit(func(f *flag.Flag) {
+		if f.Name == "socket" {
+			localClient.UseSocketOnly = true
+		}
+	})
+
+	err = rootCmd.Run(context.Background())
+	if tailscale.IsAccessDeniedError(err) && os.Getuid() != 0 && runtime.GOOS != "windows" {
+		return fmt.Errorf("%v\n\nUse 'sudo tailscale %s' or 'tailscale up --operator=$USER' to not require root.", err, strings.Join(args, " "))
+	}
+	if errors.Is(err, flag.ErrHelp) {
+		return nil
+	}
+	return err
+}
+
+func newRootCmd() *ffcli.Command {
 	rootfs := newFlagSet("tailscale")
 	rootfs.StringVar(&rootArgs.socket, "socket", paths.DefaultTailscaledSocket(), "path to tailscaled socket")
 
@@ -129,13 +192,19 @@ change in the future.
 			certCmd,
 			netlockCmd,
 			licensesCmd,
-			exitNodeCmd,
+			exitNodeCmd(),
 			updateCmd,
 			whoisCmd,
+			debugCmd,
+			driveCmd,
+		},
+		FlagSet: rootfs,
+		Exec: func(ctx context.Context, args []string) error {
+			if len(args) > 0 {
+				return fmt.Errorf("tailscale: unknown subcommand: %s", args[0])
+			}
+			return flag.ErrHelp
 		},
-		FlagSet:   rootfs,
-		Exec:      func(context.Context, []string) error { return flag.ErrHelp },
-		UsageFunc: usageFunc,
 	}
 	if envknob.UseWIPCode() {
 		rootCmd.Subcommands = append(rootCmd.Subcommands,
@@ -143,45 +212,17 @@ change in the future.
 		)
 	}
 
-	// Don't advertise these commands, but they're still explicitly available.
-	switch {
-	case slices.Contains(args, "debug"):
-		rootCmd.Subcommands = append(rootCmd.Subcommands, debugCmd)
-	case slices.Contains(args, "share"):
-		rootCmd.Subcommands = append(rootCmd.Subcommands, shareCmd)
-	}
 	if runtime.GOOS == "linux" && distro.Get() == distro.Synology {
 		rootCmd.Subcommands = append(rootCmd.Subcommands, configureHostCmd)
 	}
 
-	for _, c := range rootCmd.Subcommands {
-		if c.UsageFunc == nil {
-			c.UsageFunc = usageFunc
-		}
-	}
-
-	if err := rootCmd.Parse(args); err != nil {
-		if errors.Is(err, flag.ErrHelp) {
-			return nil
-		}
-		return err
-	}
-
-	localClient.Socket = rootArgs.socket
-	rootfs.Visit(func(f *flag.Flag) {
-		if f.Name == "socket" {
-			localClient.UseSocketOnly = true
+	walkCommands(rootCmd, func(w cmdWalk) bool {
+		if w.UsageFunc == nil {
+			w.UsageFunc = usageFunc
 		}
+		return true
 	})
-
-	err = rootCmd.Run(context.Background())
-	if tailscale.IsAccessDeniedError(err) && os.Getuid() != 0 && runtime.GOOS != "windows" {
-		return fmt.Errorf("%v\n\nUse 'sudo tailscale %s' or 'tailscale up --operator=$USER' to not require root.", err, strings.Join(args, " "))
-	}
-	if errors.Is(err, flag.ErrHelp) {
-		return nil
-	}
-	return err
+	return rootCmd
 }
 
 func fatalf(format string, a ...any) {
@@ -200,6 +241,59 @@ var rootArgs struct {
 	socket string
 }
 
+type cmdWalk struct {
+	*ffcli.Command
+	parents []*ffcli.Command
+}
+
+func (w cmdWalk) Path() string {
+	if len(w.parents) == 0 {
+		return w.Name
+	}
+
+	var sb strings.Builder
+	for _, p := range w.parents {
+		sb.WriteString(p.Name)
+		sb.WriteString(" ")
+	}
+	sb.WriteString(w.Name)
+	return sb.String()
+}
+
+// walkCommands calls f for root and all of its nested subcommands until f
+// returns false or all have been visited.
+func walkCommands(root *ffcli.Command, f func(w cmdWalk) (more bool)) {
+	var walk func(cmd *ffcli.Command, parents []*ffcli.Command, f func(cmdWalk) bool) bool
+	walk = func(cmd *ffcli.Command, parents []*ffcli.Command, f func(cmdWalk) bool) bool {
+		if !f(cmdWalk{cmd, parents}) {
+			return false
+		}
+		parents = append(parents, cmd)
+		for _, sub := range cmd.Subcommands {
+			if !walk(sub, parents, f) {
+				return false
+			}
+		}
+		return true
+	}
+	walk(root, nil, f)
+}
+
+// fullCmd returns the full "tailscale ... cmd" invocation for a subcommand.
+func fullCmd(root, cmd *ffcli.Command) (full string) {
+	walkCommands(root, func(w cmdWalk) bool {
+		if w.Command == cmd {
+			full = w.Path()
+			return false
+		}
+		return true
+	})
+	if full == "" {
+		return cmd.Name
+	}
+	return full
+}
+
 // usageFuncNoDefaultValues is like usageFunc but doesn't print default values.
 func usageFuncNoDefaultValues(c *ffcli.Command) string {
 	return usageFuncOpt(c, false)
@@ -211,23 +305,32 @@ func usageFunc(c *ffcli.Command) string {
 
 func usageFuncOpt(c *ffcli.Command, withDefaults bool) string {
 	var b strings.Builder
+	const hiddenPrefix = "HIDDEN: "
+
+	if c.ShortHelp != "" {
+		fmt.Fprintf(&b, "%s\n\n", c.ShortHelp)
+	}
 
 	fmt.Fprintf(&b, "USAGE\n")
 	if c.ShortUsage != "" {
-		fmt.Fprintf(&b, "  %s\n", c.ShortUsage)
+		fmt.Fprintf(&b, "  %s\n", strings.ReplaceAll(c.ShortUsage, "\n", "\n  "))
 	} else {
 		fmt.Fprintf(&b, "  %s\n", c.Name)
 	}
 	fmt.Fprintf(&b, "\n")
 
 	if c.LongHelp != "" {
-		fmt.Fprintf(&b, "%s\n\n", c.LongHelp)
+		help, _ := strings.CutPrefix(c.LongHelp, hiddenPrefix)
+		fmt.Fprintf(&b, "%s\n\n", help)
 	}
 
 	if len(c.Subcommands) > 0 {
 		fmt.Fprintf(&b, "SUBCOMMANDS\n")
 		tw := tabwriter.NewWriter(&b, 0, 2, 2, ' ', 0)
 		for _, subcommand := range c.Subcommands {
+			if strings.HasPrefix(subcommand.LongHelp, hiddenPrefix) {
+				continue
+			}
 			fmt.Fprintf(tw, "  %s\t%s\n", subcommand.Name, subcommand.ShortHelp)
 		}
 		tw.Flush()
@@ -240,7 +343,7 @@ func usageFuncOpt(c *ffcli.Command, withDefaults bool) string {
 		c.FlagSet.VisitAll(func(f *flag.Flag) {
 			var s string
 			name, usage := flag.UnquoteUsage(f)
-			if strings.HasPrefix(usage, "HIDDEN: ") {
+			if strings.HasPrefix(usage, hiddenPrefix) {
 				return
 			}
 			if isBoolFlag(f) {
@@ -287,3 +390,17 @@ func countFlags(fs *flag.FlagSet) (n int) {
 	fs.VisitAll(func(*flag.Flag) { n++ })
 	return n
 }
+
+// colorableOutput returns a colorable writer if stdout is a terminal (not, say,
+// redirected to a file or pipe), the Stdout writer is os.Stdout (we're not
+// embedding the CLI in wasm or a mobile app), and NO_COLOR is not set (see
+// https://no-color.org/). If any of those is not the case, ok is false
+// and w is Stdout.
+func colorableOutput() (w io.Writer, ok bool) {
+	if Stdout != os.Stdout ||
+		os.Getenv("NO_COLOR") != "" ||
+		!isatty.IsTerminal(os.Stdout.Fd()) {
+		return Stdout, false
+	}
+	return colorable.NewColorableStdout(), true
+}

cmd/tailscale/cli/cli_test.go

@@ -16,6 +16,7 @@ import (
 
 	qt "github.com/frankban/quicktest"
 	"github.com/google/go-cmp/cmp"
+	"tailscale.com/envknob"
 	"tailscale.com/health/healthmsg"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
@@ -28,6 +29,110 @@ import (
 	"tailscale.com/version/distro"
 )
 
+func TestPanicIfAnyEnvCheckedInInit(t *testing.T) {
+	envknob.PanicIfAnyEnvCheckedInInit()
+}
+
+func TestShortUsage(t *testing.T) {
+	t.Setenv("TAILSCALE_USE_WIP_CODE", "1")
+	if !envknob.UseWIPCode() {
+		t.Fatal("expected envknob.UseWIPCode() to be true")
+	}
+
+	walkCommands(newRootCmd(), func(w cmdWalk) bool {
+		c, parents := w.Command, w.parents
+
+		// Words that we expect to be in the usage.
+		words := make([]string, len(parents)+1)
+		for i, parent := range parents {
+			words[i] = parent.Name
+		}
+		words[len(parents)] = c.Name
+
+		// Check the ShortHelp starts with a capital letter.
+		if prefix, help := trimPrefixes(c.ShortHelp, "HIDDEN: ", "[ALPHA] ", "[BETA] "); help != "" {
+			if 'a' <= help[0] && help[0] <= 'z' {
+				if len(help) > 20 {
+					help = help[:20] + "…"
+				}
+				caphelp := string(help[0]-'a'+'A') + help[1:]
+				t.Errorf("command: %s: ShortHelp %q should start with a capital letter %q", strings.Join(words, " "), prefix+help, prefix+caphelp)
+			}
+		}
+
+		// Check all words appear in the usage.
+		usage := c.ShortUsage
+		for _, word := range words {
+			var ok bool
+			usage, ok = cutWord(usage, word)
+			if !ok {
+				full := strings.Join(words, " ")
+				t.Errorf("command: %s: usage %q should contain the full path %q", full, c.ShortUsage, full)
+				return true
+			}
+		}
+		return true
+	})
+}
+
+func trimPrefixes(full string, prefixes ...string) (trimmed, remaining string) {
+	s := full
+start:
+	for _, p := range prefixes {
+		var ok bool
+		s, ok = strings.CutPrefix(s, p)
+		if ok {
+			goto start
+		}
+	}
+	return full[:len(full)-len(s)], s
+}
+
+// cutWord("tailscale debug scale 123", "scale") returns (" 123", true).
+func cutWord(s, w string) (after string, ok bool) {
+	var p string
+	for {
+		p, s, ok = strings.Cut(s, w)
+		if !ok {
+			return "", false
+		}
+		if p != "" && isWordChar(p[len(p)-1]) {
+			continue
+		}
+		if s != "" && isWordChar(s[0]) {
+			continue
+		}
+		return s, true
+	}
+}
+
+func isWordChar(r byte) bool {
+	return r == '_' ||
+		('0' <= r && r <= '9') ||
+		('A' <= r && r <= 'Z') ||
+		('a' <= r && r <= 'z')
+}
+
+func TestCutWord(t *testing.T) {
+	tests := []struct {
+		in   string
+		word string
+		out  string
+		ok   bool
+	}{
+		{"tailscale debug", "debug", "", true},
+		{"tailscale debug", "bug", "", false},
+		{"tailscale debug", "tail", "", false},
+		{"tailscale debug scaley scale 123", "scale", " 123", true},
+	}
+	for _, test := range tests {
+		out, ok := cutWord(test.in, test.word)
+		if out != test.out || ok != test.ok {
+			t.Errorf("cutWord(%q, %q) = (%q, %t), wanted (%q, %t)", test.in, test.word, out, ok, test.out, test.ok)
+		}
+	}
+}
+
 // geese is a collection of gooses. It need not be complete.
 // But it should include anything handled specially (e.g. linux, windows)
 // and at least one thing that's not (darwin, freebsd).
@@ -803,7 +908,7 @@ func TestPrefFlagMapping(t *testing.T) {
 	}
 
 	prefType := reflect.TypeFor[ipn.Prefs]()
-	for i := 0; i < prefType.NumField(); i++ {
+	for i := range prefType.NumField() {
 		prefName := prefType.Field(i).Name
 		if prefHasFlag[prefName] {
 			continue
@@ -829,10 +934,14 @@ func TestPrefFlagMapping(t *testing.T) {
 			// Handled by TS_DEBUG_FIREWALL_MODE env var, we don't want to have
 			// a CLI flag for this. The Pref is used by c2n.
 			continue
-		case "TailFSShares":
+		case "DriveShares":
 			// Handled by the tailscale share subcommand, we don't want a CLI
 			// flag for this.
 			continue
+		case "InternalExitNodePrior":
+			// Used internally by LocalBackend as part of exit node usage toggling.
+			// No CLI flag for this.
+			continue
 		}
 		t.Errorf("unexpected new ipn.Pref field %q is not handled by up.go (see addPrefFlagMapping and checkForAccidentalSettingReverts)", prefName)
 	}

cmd/tailscale/cli/configure-kube.go

@@ -27,7 +27,7 @@ func init() {
 var configureKubeconfigCmd = &ffcli.Command{
 	Name:       "kubeconfig",
 	ShortHelp:  "[ALPHA] Connect to a Kubernetes cluster using a Tailscale Auth Proxy",
-	ShortUsage: "kubeconfig <hostname-or-fqdn>",
+	ShortUsage: "tailscale configure kubeconfig <hostname-or-fqdn>",
 	LongHelp: strings.TrimSpace(`
 Run this command to configure kubectl to connect to a Kubernetes cluster over Tailscale.
 
@@ -43,7 +43,20 @@ See: https://tailscale.com/s/k8s-auth-proxy
 }
 
 // kubeconfigPath returns the path to the kubeconfig file for the current user.
-func kubeconfigPath() string {
+func kubeconfigPath() (string, error) {
+	if kubeconfig := os.Getenv("KUBECONFIG"); kubeconfig != "" {
+		if version.IsSandboxedMacOS() {
+			return "", errors.New("$KUBECONFIG is incompatible with the App Store version")
+		}
+		var out string
+		for _, out = range filepath.SplitList(kubeconfig) {
+			if info, err := os.Stat(out); !os.IsNotExist(err) && !info.IsDir() {
+				break
+			}
+		}
+		return out, nil
+	}
+
 	var dir string
 	if version.IsSandboxedMacOS() {
 		// The HOME environment variable in macOS sandboxed apps is set to
@@ -55,7 +68,7 @@ func kubeconfigPath() string {
 	} else {
 		dir = homedir.HomeDir()
 	}
-	return filepath.Join(dir, ".kube", "config")
+	return filepath.Join(dir, ".kube", "config"), nil
 }
 
 func runConfigureKubeconfig(ctx context.Context, args []string) error {
@@ -76,7 +89,11 @@ func runConfigureKubeconfig(ctx context.Context, args []string) error {
 		return fmt.Errorf("no peer found with hostname %q", hostOrFQDN)
 	}
 	targetFQDN = strings.TrimSuffix(targetFQDN, ".")
-	if err := setKubeconfigForPeer(targetFQDN, kubeconfigPath()); err != nil {
+	var kubeconfig string
+	if kubeconfig, err = kubeconfigPath(); err != nil {
+		return err
+	}
+	if err = setKubeconfigForPeer(targetFQDN, kubeconfig); err != nil {
 		return err
 	}
 	printf("kubeconfig configured for %q\n", hostOrFQDN)

cmd/tailscale/cli/configure-synology-cert.go

@@ -0,0 +1,220 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package cli
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"runtime"
+	"strings"
+
+	"github.com/peterbourgon/ff/v3/ffcli"
+	"tailscale.com/hostinfo"
+	"tailscale.com/ipn"
+	"tailscale.com/version/distro"
+)
+
+var synologyConfigureCertCmd = &ffcli.Command{
+	Name:       "synology-cert",
+	Exec:       runConfigureSynologyCert,
+	ShortHelp:  "Configure Synology with a TLS certificate for your tailnet",
+	ShortUsage: "synology-cert [--domain <domain>]",
+	LongHelp: strings.TrimSpace(`
+This command is intended to run periodically as root on a Synology device to
+create or refresh the TLS certificate for the tailnet domain.
+
+See: https://tailscale.com/kb/1153/enabling-https
+`),
+	FlagSet: (func() *flag.FlagSet {
+		fs := newFlagSet("synology-cert")
+		fs.StringVar(&synologyConfigureCertArgs.domain, "domain", "", "Tailnet domain to create or refresh certificates for. Ignored if only one domain exists.")
+		return fs
+	})(),
+}
+
+var synologyConfigureCertArgs struct {
+	domain string
+}
+
+func runConfigureSynologyCert(ctx context.Context, args []string) error {
+	if len(args) > 0 {
+		return errors.New("unknown arguments")
+	}
+	if runtime.GOOS != "linux" || distro.Get() != distro.Synology {
+		return errors.New("only implemented on Synology")
+	}
+	if uid := os.Getuid(); uid != 0 {
+		return fmt.Errorf("must be run as root, not %q (%v)", os.Getenv("USER"), uid)
+	}
+	hi := hostinfo.New()
+	isDSM6 := strings.HasPrefix(hi.DistroVersion, "6.")
+	isDSM7 := strings.HasPrefix(hi.DistroVersion, "7.")
+	if !isDSM6 && !isDSM7 {
+		return fmt.Errorf("unsupported DSM version %q", hi.DistroVersion)
+	}
+
+	domain := synologyConfigureCertArgs.domain
+	if st, err := localClient.Status(ctx); err == nil {
+		if st.BackendState != ipn.Running.String() {
+			return fmt.Errorf("Tailscale is not running.")
+		} else if len(st.CertDomains) == 0 {
+			return fmt.Errorf("TLS certificate support is not enabled/configured for your tailnet.")
+		} else if len(st.CertDomains) == 1 {
+			if domain != "" && domain != st.CertDomains[0] {
+				log.Printf("Ignoring supplied domain %q, TLS certificate will be created for %q.\n", domain, st.CertDomains[0])
+			}
+			domain = st.CertDomains[0]
+		} else {
+			var found bool
+			for _, d := range st.CertDomains {
+				if d == domain {
+					found = true
+					break
+				}
+			}
+			if !found {
+				return fmt.Errorf("Domain %q was not one of the valid domain options: %q.", domain, st.CertDomains)
+			}
+		}
+	}
+
+	// Check for an existing certificate, and replace it if it already exists
+	var id string
+	certs, err := listCerts(ctx, synowebapiCommand{})
+	if err != nil {
+		return err
+	}
+	for _, c := range certs {
+		if c.Subject.CommonName == domain {
+			id = c.ID
+			break
+		}
+	}
+
+	certPEM, keyPEM, err := localClient.CertPair(ctx, domain)
+	if err != nil {
+		return err
+	}
+
+	// Certs have to be written to file for the upload command to work.
+	tmpDir, err := os.MkdirTemp("", "")
+	if err != nil {
+		return fmt.Errorf("can't create temp dir: %w", err)
+	}
+	defer os.RemoveAll(tmpDir)
+	keyFile := path.Join(tmpDir, "key.pem")
+	os.WriteFile(keyFile, keyPEM, 0600)
+	certFile := path.Join(tmpDir, "cert.pem")
+	os.WriteFile(certFile, certPEM, 0600)
+
+	if err := uploadCert(ctx, synowebapiCommand{}, certFile, keyFile, id); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type subject struct {
+	CommonName string `json:"common_name"`
+}
+
+type certificateInfo struct {
+	ID      string  `json:"id"`
+	Desc    string  `json:"desc"`
+	Subject subject `json:"subject"`
+}
+
+// listCerts fetches a list of the certificates that DSM knows about
+func listCerts(ctx context.Context, c synoAPICaller) ([]certificateInfo, error) {
+	rawData, err := c.Call(ctx, "SYNO.Core.Certificate.CRT", "list", nil)
+	if err != nil {
+		return nil, err
+	}
+
+	var payload struct {
+		Certificates []certificateInfo `json:"certificates"`
+	}
+	if err := json.Unmarshal(rawData, &payload); err != nil {
+		return nil, fmt.Errorf("decoding certificate list response payload: %w", err)
+	}
+
+	return payload.Certificates, nil
+}
+
+// uploadCert creates or replaces a certificate. If id is given, it will attempt to replace the certificate with that ID.
+func uploadCert(ctx context.Context, c synoAPICaller, certFile, keyFile string, id string) error {
+	params := map[string]string{
+		"key_tmp":  keyFile,
+		"cert_tmp": certFile,
+		"desc":     "Tailnet Certificate",
+	}
+	if id != "" {
+		params["id"] = id
+	}
+
+	rawData, err := c.Call(ctx, "SYNO.Core.Certificate", "import", params)
+	if err != nil {
+		return err
+	}
+
+	var payload struct {
+		NewID string `json:"id"`
+	}
+	if err := json.Unmarshal(rawData, &payload); err != nil {
+		return fmt.Errorf("decoding certificate upload response payload: %w", err)
+	}
+	log.Printf("Tailnet Certificate uploaded with ID %q.", payload.NewID)
+
+	return nil
+
+}
+
+type synoAPICaller interface {
+	Call(context.Context, string, string, map[string]string) (json.RawMessage, error)
+}
+
+type apiResponse struct {
+	Success bool            `json:"success"`
+	Error   *apiError       `json:"error,omitempty"`
+	Data    json.RawMessage `json:"data"`
+}
+
+type apiError struct {
+	Code   int64  `json:"code"`
+	Errors string `json:"errors"`
+}
+
+// synowebapiCommand implements synoAPICaller using the /usr/syno/bin/synowebapi binary. Must be run as root.
+type synowebapiCommand struct{}
+
+func (s synowebapiCommand) Call(ctx context.Context, api, method string, params map[string]string) (json.RawMessage, error) {
+	args := []string{"--exec", fmt.Sprintf("api=%s", api), fmt.Sprintf("method=%s", method)}
+
+	for k, v := range params {
+		args = append(args, fmt.Sprintf("%s=%q", k, v))
+	}
+
+	out, err := exec.CommandContext(ctx, "/usr/syno/bin/synowebapi", args...).Output()
+	if err != nil {
+		return nil, fmt.Errorf("calling %q method of %q API: %v, %s", method, api, err, out)
+	}
+
+	var payload apiResponse
+	if err := json.Unmarshal(out, &payload); err != nil {
+		return nil, fmt.Errorf("decoding response json from %q method of %q API: %w", method, api, err)
+	}
+
+	if payload.Error != nil {
+		return nil, fmt.Errorf("error response from %q method of %q API: %v", method, api, payload.Error)
+	}
+
+	return payload.Data, nil
+}

cmd/tailscale/cli/configure-synology-cert_test.go

@@ -0,0 +1,140 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package cli
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+type fakeAPICaller struct {
+	Data  json.RawMessage
+	Error error
+}
+
+func (c fakeAPICaller) Call(_ context.Context, _, _ string, _ map[string]string) (json.RawMessage, error) {
+	return c.Data, c.Error
+}
+
+func Test_listCerts(t *testing.T) {
+	tests := []struct {
+		name    string
+		caller  synoAPICaller
+		want    []certificateInfo
+		wantErr bool
+	}{
+		{
+			name: "normal response",
+			caller: fakeAPICaller{
+				Data: json.RawMessage(`{
+"certificates" : [
+	{
+		"desc" : "Tailnet Certificate",
+		"id" : "cG2XBt",
+		"is_broken" : false,
+		"is_default" : false,
+		"issuer" : {
+			"common_name" : "R3",
+			"country" : "US",
+			"organization" : "Let's Encrypt"
+		},
+		"key_types" : "ECC",
+		"renewable" : false,
+		"services" : [
+			{
+			"display_name" : "DSM Desktop Service",
+			"display_name_i18n" : "common:web_desktop",
+			"isPkg" : false,
+			"multiple_cert" : true,
+			"owner" : "root",
+			"service" : "default",
+			"subscriber" : "system",
+			"user_setable" : true
+			}
+		],
+		"signature_algorithm" : "sha256WithRSAEncryption",
+		"subject" : {
+			"common_name" : "foo.tailscale.ts.net",
+			"sub_alt_name" : [ "foo.tailscale.ts.net" ]
+		},
+		"user_deletable" : true,
+		"valid_from" : "Sep 26 11:39:43 2023 GMT",
+		"valid_till" : "Dec 25 11:39:42 2023 GMT"
+	},
+	{
+		"desc" : "",
+		"id" : "sgmnpb",
+		"is_broken" : false,
+		"is_default" : false,
+		"issuer" : {
+			"city" : "Taipei",
+			"common_name" : "Synology Inc. CA",
+			"country" : "TW",
+			"organization" : "Synology Inc."
+		},
+		"key_types" : "",
+		"renewable" : false,
+		"self_signed_cacrt_info" : {
+			"issuer" : {
+			"city" : "Taipei",
+			"common_name" : "Synology Inc. CA",
+			"country" : "TW",
+			"organization" : "Synology Inc."
+			},
+			"subject" : {
+			"city" : "Taipei",
+			"common_name" : "Synology Inc. CA",
+			"country" : "TW",
+			"organization" : "Synology Inc."
+			}
+		},
+		"services" : [],
+		"signature_algorithm" : "sha256WithRSAEncryption",
+		"subject" : {
+			"city" : "Taipei",
+			"common_name" : "synology.com",
+			"country" : "TW",
+			"organization" : "Synology Inc.",
+			"sub_alt_name" : []
+		},
+		"user_deletable" : true,
+		"valid_from" : "May 27 00:23:19 2019 GMT",
+		"valid_till" : "Feb 11 00:23:19 2039 GMT"
+	}
+]
+}`),
+				Error: nil,
+			},
+			want: []certificateInfo{
+				{Desc: "Tailnet Certificate", ID: "cG2XBt", Subject: subject{CommonName: "foo.tailscale.ts.net"}},
+				{Desc: "", ID: "sgmnpb", Subject: subject{CommonName: "synology.com"}},
+			},
+		},
+		{
+			name:    "call error",
+			caller:  fakeAPICaller{nil, fmt.Errorf("caller failed")},
+			wantErr: true,
+		},
+		{
+			name:    "payload decode error",
+			caller:  fakeAPICaller{json.RawMessage("This isn't JSON!"), nil},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := listCerts(context.Background(), tt.caller)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("listCerts() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("listCerts() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

cmd/tailscale/cli/configure-synology.go

@@ -22,10 +22,11 @@ import (
 // used to configure Synology devices, but is now a compatibility alias to
 // "tailscale configure synology".
 var configureHostCmd = &ffcli.Command{
-	Name:      "configure-host",
-	Exec:      runConfigureSynology,
-	ShortHelp: synologyConfigureCmd.ShortHelp,
-	LongHelp:  synologyConfigureCmd.LongHelp,
+	Name:       "configure-host",
+	Exec:       runConfigureSynology,
+	ShortUsage: "tailscale configure-host",
+	ShortHelp:  synologyConfigureCmd.ShortHelp,
+	LongHelp:   synologyConfigureCmd.LongHelp,
 	FlagSet: (func() *flag.FlagSet {
 		fs := newFlagSet("configure-host")
 		return fs
@@ -33,9 +34,10 @@ var configureHostCmd = &ffcli.Command{
 }
 
 var synologyConfigureCmd = &ffcli.Command{
-	Name:      "synology",
-	Exec:      runConfigureSynology,
-	ShortHelp: "Configure Synology to enable outbound connections",
+	Name:       "synology",
+	Exec:       runConfigureSynology,
+	ShortUsage: "tailscale configure synology",
+	ShortHelp:  "Configure Synology to enable outbound connections",
 	LongHelp: strings.TrimSpace(`
 This command is intended to run at boot as root on a Synology device to
 create the /dev/net/tun device and give the tailscaled binary permission

cmd/tailscale/cli/configure.go

@@ -4,7 +4,6 @@
 package cli
 
 import (
-	"context"
 	"flag"
 	"runtime"
 	"strings"
@@ -14,8 +13,9 @@ import (
 )
 
 var configureCmd = &ffcli.Command{
-	Name:      "configure",
-	ShortHelp: "[ALPHA] Configure the host to enable more Tailscale features",
+	Name:       "configure",
+	ShortUsage: "tailscale configure <subcommand>",
+	ShortHelp:  "[ALPHA] Configure the host to enable more Tailscale features",
 	LongHelp: strings.TrimSpace(`
 The 'configure' set of commands are intended to provide a way to enable different
 services on the host to use Tailscale in more ways.
@@ -25,14 +25,12 @@ services on the host to use Tailscale in more ways.
 		return fs
 	})(),
 	Subcommands: configureSubcommands(),
-	Exec: func(ctx context.Context, args []string) error {
-		return flag.ErrHelp
-	},
 }
 
 func configureSubcommands() (out []*ffcli.Command) {
 	if runtime.GOOS == "linux" && distro.Get() == distro.Synology {
 		out = append(out, synologyConfigureCmd)
+		out = append(out, synologyConfigureCertCmd)
 	}
 	return out
 }

cmd/tailscale/cli/debug.go

@@ -45,9 +45,10 @@ import (
 )
 
 var debugCmd = &ffcli.Command{
-	Name:     "debug",
-	Exec:     runDebug,
-	LongHelp: `"tailscale debug" contains misc debug facilities; it is not a stable interface.`,
+	Name:       "debug",
+	Exec:       runDebug,
+	ShortUsage: "tailscale debug <debug-flags | subcommand>",
+	LongHelp:   `HIDDEN: "tailscale debug" contains misc debug facilities; it is not a stable interface.`,
 	FlagSet: (func() *flag.FlagSet {
 		fs := newFlagSet("debug")
 		fs.StringVar(&debugArgs.file, "file", "", "get, delete:NAME, or NAME")
@@ -58,15 +59,16 @@ var debugCmd = &ffcli.Command{
 	})(),
 	Subcommands: []*ffcli.Command{
 		{
-			Name:      "derp-map",
-			Exec:      runDERPMap,
-			ShortHelp: "print DERP map",
+			Name:       "derp-map",
+			ShortUsage: "tailscale debug derp-map",
+			Exec:       runDERPMap,
+			ShortHelp:  "Print DERP map",
 		},
 		{
 			Name:       "component-logs",
-			Exec:       runDebugComponentLogs,
-			ShortHelp:  "enable/disable debug logs for a component",
 			ShortUsage: "tailscale debug component-logs [" + strings.Join(ipn.DebuggableComponents, "|") + "]",
+			Exec:       runDebugComponentLogs,
+			ShortHelp:  "Enable/disable debug logs for a component",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("component-logs")
 				fs.DurationVar(&debugComponentLogsArgs.forDur, "for", time.Hour, "how long to enable debug logs for; zero or negative means to disable")
@@ -74,14 +76,16 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "daemon-goroutines",
-			Exec:      runDaemonGoroutines,
-			ShortHelp: "print tailscaled's goroutines",
+			Name:       "daemon-goroutines",
+			ShortUsage: "tailscale debug daemon-goroutines",
+			Exec:       runDaemonGoroutines,
+			ShortHelp:  "Print tailscaled's goroutines",
 		},
 		{
-			Name:      "daemon-logs",
-			Exec:      runDaemonLogs,
-			ShortHelp: "watch tailscaled's server logs",
+			Name:       "daemon-logs",
+			ShortUsage: "tailscale debug daemon-logs",
+			Exec:       runDaemonLogs,
+			ShortHelp:  "Watch tailscaled's server logs",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("daemon-logs")
 				fs.IntVar(&daemonLogsArgs.verbose, "verbose", 0, "verbosity level")
@@ -90,9 +94,10 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "metrics",
-			Exec:      runDaemonMetrics,
-			ShortHelp: "print tailscaled's metrics",
+			Name:       "metrics",
+			ShortUsage: "tailscale debug metrics",
+			Exec:       runDaemonMetrics,
+			ShortHelp:  "Print tailscaled's metrics",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("metrics")
 				fs.BoolVar(&metricsArgs.watch, "watch", false, "print JSON dump of delta values")
@@ -100,80 +105,95 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "env",
-			Exec:      runEnv,
-			ShortHelp: "print cmd/tailscale environment",
+			Name:       "env",
+			ShortUsage: "tailscale debug env",
+			Exec:       runEnv,
+			ShortHelp:  "Print cmd/tailscale environment",
 		},
 		{
-			Name:      "stat",
-			Exec:      runStat,
-			ShortHelp: "stat a file",
+			Name:       "stat",
+			ShortUsage: "tailscale debug stat <files...>",
+			Exec:       runStat,
+			ShortHelp:  "Stat a file",
 		},
 		{
-			Name:      "hostinfo",
-			Exec:      runHostinfo,
-			ShortHelp: "print hostinfo",
+			Name:       "hostinfo",
+			ShortUsage: "tailscale debug hostinfo",
+			Exec:       runHostinfo,
+			ShortHelp:  "Print hostinfo",
 		},
 		{
-			Name:      "local-creds",
-			Exec:      runLocalCreds,
-			ShortHelp: "print how to access Tailscale LocalAPI",
+			Name:       "local-creds",
+			ShortUsage: "tailscale debug local-creds",
+			Exec:       runLocalCreds,
+			ShortHelp:  "Print how to access Tailscale LocalAPI",
 		},
 		{
-			Name:      "restun",
-			Exec:      localAPIAction("restun"),
-			ShortHelp: "force a magicsock restun",
+			Name:       "restun",
+			ShortUsage: "tailscale debug restun",
+			Exec:       localAPIAction("restun"),
+			ShortHelp:  "Force a magicsock restun",
 		},
 		{
-			Name:      "rebind",
-			Exec:      localAPIAction("rebind"),
-			ShortHelp: "force a magicsock rebind",
+			Name:       "rebind",
+			ShortUsage: "tailscale debug rebind",
+			Exec:       localAPIAction("rebind"),
+			ShortHelp:  "Force a magicsock rebind",
 		},
 		{
-			Name:      "derp-set-on-demand",
-			Exec:      localAPIAction("derp-set-homeless"),
-			ShortHelp: "enable DERP on-demand mode (breaks reachability)",
+			Name:       "derp-set-on-demand",
+			ShortUsage: "tailscale debug derp-set-on-demand",
+			Exec:       localAPIAction("derp-set-homeless"),
+			ShortHelp:  "Enable DERP on-demand mode (breaks reachability)",
 		},
 		{
-			Name:      "derp-unset-on-demand",
-			Exec:      localAPIAction("derp-unset-homeless"),
-			ShortHelp: "disable DERP on-demand mode",
+			Name:       "derp-unset-on-demand",
+			ShortUsage: "tailscale debug derp-unset-on-demand",
+			Exec:       localAPIAction("derp-unset-homeless"),
+			ShortHelp:  "Disable DERP on-demand mode",
 		},
 		{
-			Name:      "break-tcp-conns",
-			Exec:      localAPIAction("break-tcp-conns"),
-			ShortHelp: "break any open TCP connections from the daemon",
+			Name:       "break-tcp-conns",
+			ShortUsage: "tailscale debug break-tcp-conns",
+			Exec:       localAPIAction("break-tcp-conns"),
+			ShortHelp:  "Break any open TCP connections from the daemon",
 		},
 		{
-			Name:      "break-derp-conns",
-			Exec:      localAPIAction("break-derp-conns"),
-			ShortHelp: "break any open DERP connections from the daemon",
+			Name:       "break-derp-conns",
+			ShortUsage: "tailscale debug break-derp-conns",
+			Exec:       localAPIAction("break-derp-conns"),
+			ShortHelp:  "Break any open DERP connections from the daemon",
 		},
 		{
-			Name:      "pick-new-derp",
-			Exec:      localAPIAction("pick-new-derp"),
-			ShortHelp: "switch to some other random DERP home region for a short time",
+			Name:       "pick-new-derp",
+			ShortUsage: "tailscale debug pick-new-derp",
+			Exec:       localAPIAction("pick-new-derp"),
+			ShortHelp:  "Switch to some other random DERP home region for a short time",
 		},
 		{
-			Name:      "force-netmap-update",
-			Exec:      localAPIAction("force-netmap-update"),
-			ShortHelp: "force a full no-op netmap update (for load testing)",
+			Name:       "force-netmap-update",
+			ShortUsage: "tailscale debug force-netmap-update",
+			Exec:       localAPIAction("force-netmap-update"),
+			ShortHelp:  "Force a full no-op netmap update (for load testing)",
 		},
 		{
 			// TODO(bradfitz,maisem): eventually promote this out of debug
-			Name:      "reload-config",
-			Exec:      reloadConfig,
-			ShortHelp: "reload config",
+			Name:       "reload-config",
+			ShortUsage: "tailscale debug reload-config",
+			Exec:       reloadConfig,
+			ShortHelp:  "Reload config",
 		},
 		{
-			Name:      "control-knobs",
-			Exec:      debugControlKnobs,
-			ShortHelp: "see current control knobs",
+			Name:       "control-knobs",
+			ShortUsage: "tailscale debug control-knobs",
+			Exec:       debugControlKnobs,
+			ShortHelp:  "See current control knobs",
 		},
 		{
-			Name:      "prefs",
-			Exec:      runPrefs,
-			ShortHelp: "print prefs",
+			Name:       "prefs",
+			ShortUsage: "tailscale debug prefs",
+			Exec:       runPrefs,
+			ShortHelp:  "Print prefs",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("prefs")
 				fs.BoolVar(&prefsArgs.pretty, "pretty", false, "If true, pretty-print output")
@@ -181,9 +201,10 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "watch-ipn",
-			Exec:      runWatchIPN,
-			ShortHelp: "subscribe to IPN message bus",
+			Name:       "watch-ipn",
+			ShortUsage: "tailscale debug watch-ipn",
+			Exec:       runWatchIPN,
+			ShortHelp:  "Subscribe to IPN message bus",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("watch-ipn")
 				fs.BoolVar(&watchIPNArgs.netmap, "netmap", true, "include netmap in messages")
@@ -194,9 +215,10 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "netmap",
-			Exec:      runNetmap,
-			ShortHelp: "print the current network map",
+			Name:       "netmap",
+			ShortUsage: "tailscale debug netmap",
+			Exec:       runNetmap,
+			ShortHelp:  "Print the current network map",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("netmap")
 				fs.BoolVar(&netmapArgs.showPrivateKey, "show-private-key", false, "include node private key in printed netmap")
@@ -204,14 +226,17 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "via",
+			Name: "via",
+			ShortUsage: "tailscale debug via <site-id> <v4-cidr>\n" +
+				"tailscale debug via <v6-route>",
 			Exec:      runVia,
-			ShortHelp: "convert between site-specific IPv4 CIDRs and IPv6 'via' routes",
+			ShortHelp: "Convert between site-specific IPv4 CIDRs and IPv6 'via' routes",
 		},
 		{
-			Name:      "ts2021",
-			Exec:      runTS2021,
-			ShortHelp: "debug ts2021 protocol connectivity",
+			Name:       "ts2021",
+			ShortUsage: "tailscale debug ts2021",
+			Exec:       runTS2021,
+			ShortHelp:  "Debug ts2021 protocol connectivity",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("ts2021")
 				fs.StringVar(&ts2021Args.host, "host", "controlplane.tailscale.com", "hostname of control plane")
@@ -221,9 +246,10 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "set-expire",
-			Exec:      runSetExpire,
-			ShortHelp: "manipulate node key expiry for testing",
+			Name:       "set-expire",
+			ShortUsage: "tailscale debug set-expire --in=1m",
+			Exec:       runSetExpire,
+			ShortHelp:  "Manipulate node key expiry for testing",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("set-expire")
 				fs.DurationVar(&setExpireArgs.in, "in", 0, "if non-zero, set node key to expire this duration from now")
@@ -231,9 +257,10 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "dev-store-set",
-			Exec:      runDevStoreSet,
-			ShortHelp: "set a key/value pair during development",
+			Name:       "dev-store-set",
+			ShortUsage: "tailscale debug dev-store-set",
+			Exec:       runDevStoreSet,
+			ShortHelp:  "Set a key/value pair during development",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("store-set")
 				fs.BoolVar(&devStoreSetArgs.danger, "danger", false, "accept danger")
@@ -241,14 +268,16 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "derp",
-			Exec:      runDebugDERP,
-			ShortHelp: "test a DERP configuration",
+			Name:       "derp",
+			ShortUsage: "tailscale debug derp",
+			Exec:       runDebugDERP,
+			ShortHelp:  "Test a DERP configuration",
 		},
 		{
-			Name:      "capture",
-			Exec:      runCapture,
-			ShortHelp: "streams pcaps for debugging",
+			Name:       "capture",
+			ShortUsage: "tailscale debug capture",
+			Exec:       runCapture,
+			ShortHelp:  "Streams pcaps for debugging",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("capture")
 				fs.StringVar(&captureArgs.outFile, "o", "", "path to stream the pcap (or - for stdout), leave empty to start wireshark")
@@ -256,9 +285,10 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "portmap",
-			Exec:      debugPortmap,
-			ShortHelp: "run portmap debugging",
+			Name:       "portmap",
+			ShortUsage: "tailscale debug portmap",
+			Exec:       debugPortmap,
+			ShortHelp:  "Run portmap debugging",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("portmap")
 				fs.DurationVar(&debugPortmapArgs.duration, "duration", 5*time.Second, "timeout for port mapping")
@@ -270,14 +300,16 @@ var debugCmd = &ffcli.Command{
 			})(),
 		},
 		{
-			Name:      "peer-endpoint-changes",
-			Exec:      runPeerEndpointChanges,
-			ShortHelp: "prints debug information about a peer's endpoint changes",
+			Name:       "peer-endpoint-changes",
+			ShortUsage: "tailscale debug peer-endpoint-changes <hostname-or-IP>",
+			Exec:       runPeerEndpointChanges,
+			ShortHelp:  "Prints debug information about a peer's endpoint changes",
 		},
 		{
-			Name:      "dial-types",
-			Exec:      runDebugDialTypes,
-			ShortHelp: "prints debug information about connecting to a given host or IP",
+			Name:       "dial-types",
+			ShortUsage: "tailscale debug dial-types <hostname-or-IP> <port>",
+			Exec:       runDebugDialTypes,
+			ShortHelp:  "Prints debug information about connecting to a given host or IP",
 			FlagSet: (func() *flag.FlagSet {
 				fs := newFlagSet("dial-types")
 				fs.StringVar(&debugDialTypesArgs.network, "network", "tcp", `network type to dial ("tcp", "udp", etc.)`)
@@ -314,7 +346,7 @@ func outName(dst string) string {
 
 func runDebug(ctx context.Context, args []string) error {
 	if len(args) > 0 {
-		return errors.New("unknown arguments")
+		return fmt.Errorf("tailscale debug: unknown subcommand: %s", args[0])
 	}
 	var usedFlag bool
 	if out := debugArgs.cpuFile; out != "" {
@@ -369,7 +401,7 @@ func runDebug(ctx context.Context, args []string) error {
 		// to subcommands.
 		return nil
 	}
-	return errors.New("see 'tailscale debug --help")
+	return errors.New("tailscale debug: subcommand or flag required")
 }
 
 func runLocalCreds(ctx context.Context, args []string) error {
@@ -453,7 +485,7 @@ func runWatchIPN(ctx context.Context, args []string) error {
 		return err
 	}
 	defer watcher.Close()
-	fmt.Fprintf(os.Stderr, "Connected.\n")
+	fmt.Fprintf(Stderr, "Connected.\n")
 	for seen := 0; watchIPNArgs.count == 0 || seen < watchIPNArgs.count; seen++ {
 		n, err := watcher.Next()
 		if err != nil {
@@ -563,7 +595,7 @@ func runStat(ctx context.Context, args []string) error {
 func runHostinfo(ctx context.Context, args []string) error {
 	hi := hostinfo.New()
 	j, _ := json.MarshalIndent(hi, "", "  ")
-	os.Stdout.Write(j)
+	Stdout.Write(j)
 	return nil
 }
 
@@ -716,7 +748,7 @@ var ts2021Args struct {
 }
 
 func runTS2021(ctx context.Context, args []string) error {
-	log.SetOutput(os.Stdout)
+	log.SetOutput(Stdout)
 	log.SetFlags(log.Ltime | log.Lmicroseconds)
 
 	keysURL := "https://" + ts2021Args.host + "/key?v=" + strconv.Itoa(ts2021Args.version)
@@ -810,7 +842,7 @@ var debugComponentLogsArgs struct {
 
 func runDebugComponentLogs(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: debug component-logs [" + strings.Join(ipn.DebuggableComponents, "|") + "]")
+		return errors.New("usage: tailscale debug component-logs [" + strings.Join(ipn.DebuggableComponents, "|") + "]")
 	}
 	component := args[0]
 	dur := debugComponentLogsArgs.forDur
@@ -833,7 +865,7 @@ var devStoreSetArgs struct {
 
 func runDevStoreSet(ctx context.Context, args []string) error {
 	if len(args) != 2 {
-		return errors.New("usage: dev-store-set --danger <key> <value>")
+		return errors.New("usage: tailscale debug dev-store-set --danger <key> <value>")
 	}
 	if !devStoreSetArgs.danger {
 		return errors.New("this command is dangerous; use --danger to proceed")
@@ -851,7 +883,7 @@ func runDevStoreSet(ctx context.Context, args []string) error {
 
 func runDebugDERP(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: debug derp <region>")
+		return errors.New("usage: tailscale debug derp <region>")
 	}
 	st, err := localClient.DebugDERPRegion(ctx, args[0])
 	if err != nil {
@@ -867,7 +899,7 @@ var setExpireArgs struct {
 
 func runSetExpire(ctx context.Context, args []string) error {
 	if len(args) != 0 || setExpireArgs.in == 0 {
-		return errors.New("usage --in=<duration>")
+		return errors.New("usage: tailscale debug set-expire --in=<duration>")
 	}
 	return localClient.DebugSetExpireIn(ctx, setExpireArgs.in)
 }
@@ -885,7 +917,7 @@ func runCapture(ctx context.Context, args []string) error {
 
 	switch captureArgs.outFile {
 	case "-":
-		fmt.Fprintln(os.Stderr, "Press Ctrl-C to stop the capture.")
+		fmt.Fprintln(Stderr, "Press Ctrl-C to stop the capture.")
 		_, err = io.Copy(os.Stdout, stream)
 		return err
 	case "":
@@ -911,7 +943,7 @@ func runCapture(ctx context.Context, args []string) error {
 		return err
 	}
 	defer f.Close()
-	fmt.Fprintln(os.Stderr, "Press Ctrl-C to stop the capture.")
+	fmt.Fprintln(Stderr, "Press Ctrl-C to stop the capture.")
 	_, err = io.Copy(f, stream)
 	return err
 }
@@ -966,7 +998,7 @@ func runPeerEndpointChanges(ctx context.Context, args []string) error {
 	}
 
 	if len(args) != 1 || args[0] == "" {
-		return errors.New("usage: peer-status <hostname-or-IP>")
+		return errors.New("usage: tailscale debug peer-endpoint-changes <hostname-or-IP>")
 	}
 	var ip string
 
@@ -1042,7 +1074,7 @@ func runDebugDialTypes(ctx context.Context, args []string) error {
 	}
 
 	if len(args) != 2 || args[0] == "" || args[1] == "" {
-		return errors.New("usage: dial-types <hostname-or-IP> <port>")
+		return errors.New("usage: tailscale debug dial-types <hostname-or-IP> <port>")
 	}
 
 	port, err := strconv.ParseUint(args[1], 10, 16)

cmd/tailscale/cli/down.go

@@ -14,7 +14,7 @@ import (
 
 var downCmd = &ffcli.Command{
 	Name:       "down",
-	ShortUsage: "down",
+	ShortUsage: "tailscale down",
 	ShortHelp:  "Disconnect from Tailscale",
 
 	Exec:    runDown,

cmd/tailscale/cli/drive.go

@@ -5,116 +5,113 @@ package cli
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"strings"
 
 	"github.com/peterbourgon/ff/v3/ffcli"
-	"tailscale.com/tailfs"
+	"tailscale.com/drive"
 )
 
 const (
-	shareSetUsage    = "share set <name> <path>"
-	shareRenameUsage = "share rename <oldname> <newname>"
-	shareRemoveUsage = "share remove <name>"
-	shareListUsage   = "share list"
+	driveShareUsage   = "tailscale drive share <name> <path>"
+	driveRenameUsage  = "tailscale drive rename <oldname> <newname>"
+	driveUnshareUsage = "tailscale drive unshare <name>"
+	driveListUsage    = "tailscale drive list"
 )
 
-var shareCmd = &ffcli.Command{
-	Name:      "share",
+var driveCmd = &ffcli.Command{
+	Name:      "drive",
 	ShortHelp: "Share a directory with your tailnet",
 	ShortUsage: strings.Join([]string{
-		shareSetUsage,
-		shareRemoveUsage,
-		shareListUsage,
-	}, "\n  "),
+		driveShareUsage,
+		driveRenameUsage,
+		driveUnshareUsage,
+		driveListUsage,
+	}, "\n"),
 	LongHelp:  buildShareLongHelp(),
 	UsageFunc: usageFuncNoDefaultValues,
 	Subcommands: []*ffcli.Command{
 		{
-			Name:      "set",
-			Exec:      runShareSet,
-			ShortHelp: "[ALPHA] set a share",
-			UsageFunc: usageFunc,
+			Name:       "share",
+			ShortUsage: driveShareUsage,
+			Exec:       runDriveShare,
+			ShortHelp:  "[ALPHA] Create or modify a share",
 		},
 		{
-			Name:      "rename",
-			ShortHelp: "[ALPHA] rename a share",
-			Exec:      runShareRename,
-			UsageFunc: usageFunc,
+			Name:       "rename",
+			ShortUsage: driveRenameUsage,
+			ShortHelp:  "[ALPHA] Rename a share",
+			Exec:       runDriveRename,
 		},
 		{
-			Name:      "remove",
-			ShortHelp: "[ALPHA] remove a share",
-			Exec:      runShareRemove,
-			UsageFunc: usageFunc,
+			Name:       "unshare",
+			ShortUsage: driveUnshareUsage,
+			ShortHelp:  "[ALPHA] Remove a share",
+			Exec:       runDriveUnshare,
 		},
 		{
-			Name:      "list",
-			ShortHelp: "[ALPHA] list current shares",
-			Exec:      runShareList,
-			UsageFunc: usageFunc,
+			Name:       "list",
+			ShortUsage: driveListUsage,
+			ShortHelp:  "[ALPHA] List current shares",
+			Exec:       runDriveList,
 		},
 	},
-	Exec: func(context.Context, []string) error {
-		return errors.New("share subcommand required; run 'tailscale share -h' for details")
-	},
 }
 
-// runShareSet is the entry point for the "tailscale share set" command.
-func runShareSet(ctx context.Context, args []string) error {
+// runDriveShare is the entry point for the "tailscale drive share" command.
+func runDriveShare(ctx context.Context, args []string) error {
 	if len(args) != 2 {
-		return fmt.Errorf("usage: tailscale %v", shareSetUsage)
+		return fmt.Errorf("usage: %s", driveShareUsage)
 	}
 
 	name, path := args[0], args[1]
 
-	err := localClient.TailFSShareSet(ctx, &tailfs.Share{
+	err := localClient.DriveShareSet(ctx, &drive.Share{
 		Name: name,
 		Path: path,
 	})
 	if err == nil {
-		fmt.Printf("Set share %q at %q\n", name, path)
+		fmt.Printf("Sharing %q as %q\n", path, name)
 	}
 	return err
 }
 
-// runShareRemove is the entry point for the "tailscale share remove" command.
-func runShareRemove(ctx context.Context, args []string) error {
+// runDriveUnshare is the entry point for the "tailscale drive unshare" command.
+func runDriveUnshare(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return fmt.Errorf("usage: tailscale %v", shareRemoveUsage)
+		return fmt.Errorf("usage: %s", driveUnshareUsage)
 	}
 	name := args[0]
 
-	err := localClient.TailFSShareRemove(ctx, name)
+	err := localClient.DriveShareRemove(ctx, name)
 	if err == nil {
-		fmt.Printf("Removed share %q\n", name)
+		fmt.Printf("No longer sharing %q\n", name)
 	}
 	return err
 }
 
-// runShareRename is the entry point for the "tailscale share rename" command.
-func runShareRename(ctx context.Context, args []string) error {
+// runDriveRename is the entry point for the "tailscale drive rename" command.
+func runDriveRename(ctx context.Context, args []string) error {
 	if len(args) != 2 {
-		return fmt.Errorf("usage: tailscale %v", shareRenameUsage)
+		return fmt.Errorf("usage: %s", driveRenameUsage)
 	}
 	oldName := args[0]
 	newName := args[1]
 
-	err := localClient.TailFSShareRename(ctx, oldName, newName)
+	err := localClient.DriveShareRename(ctx, oldName, newName)
 	if err == nil {
 		fmt.Printf("Renamed share %q to %q\n", oldName, newName)
 	}
 	return err
 }
 
-// runShareList is the entry point for the "tailscale share list" command.
-func runShareList(ctx context.Context, args []string) error {
+// runDriveList is the entry point for the "tailscale drive list" command.
+func runDriveList(ctx context.Context, args []string) error {
 	if len(args) != 0 {
-		return fmt.Errorf("usage: tailscale %v", shareListUsage)
+		return fmt.Errorf("usage: %s", driveListUsage)
 	}
 
-	shares, err := localClient.TailFSShareList(ctx)
+	shares, err := localClient.DriveShareList(ctx)
 	if err != nil {
 		return err
 	}
@@ -145,17 +142,17 @@ func runShareList(ctx context.Context, args []string) error {
 
 func buildShareLongHelp() string {
 	longHelpAs := ""
-	if tailfs.AllowShareAs() {
+	if drive.AllowShareAs() {
 		longHelpAs = shareLongHelpAs
 	}
 	return fmt.Sprintf(shareLongHelpBase, longHelpAs)
 }
 
-var shareLongHelpBase = `Tailscale share allows you to share directories with other machines on your tailnet.
+var shareLongHelpBase = `Taildrive allows you to share directories with other machines on your tailnet.
 
-In order to share folders, your node needs to have the node attribute "tailfs:share".
+In order to share folders, your node needs to have the node attribute "drive:share".
 
-In order to access shares, your node needs to have the node attribute "tailfs:access".
+In order to access shares, your node needs to have the node attribute "drive:access".
 
 For example, to enable sharing and accessing shares for all member nodes:
 
@@ -163,14 +160,14 @@ For example, to enable sharing and accessing shares for all member nodes:
     {
       "target": ["autogroup:member"],
       "attr": [
-        "tailfs:share",
-        "tailfs:access",
+        "drive:share",
+        "drive:access",
       ],
     }]
 
 Each share is identified by a name and points to a directory at a specific path. For example, to share the path /Users/me/Documents under the name "docs", you would run:
 
-  $ tailscale share set docs /Users/me/Documents
+  $ tailscale drive share docs /Users/me/Documents
 
 Note that the system forces share names to lowercase to avoid problems with clients that don't support case-sensitive filenames.
 
@@ -191,7 +188,7 @@ Permissions to access shares are controlled via ACLs. For example, to give yours
       "src": ["mylogin@domain.com"],
       "dst": ["mylaptop's ip address"],
       "app": {
-        "tailscale.com/cap/tailfs": [{
+        "tailscale.com/cap/drive": [{
           "shares": ["docs"],
           "access": "rw"
         }]
@@ -201,7 +198,7 @@ Permissions to access shares are controlled via ACLs. For example, to give yours
       "src": ["group:home"],
       "dst": ["mylaptop"],
       "app": {
-        "tailscale.com/cap/tailfs": [{
+        "tailscale.com/cap/drive": [{
           "shares": ["docs"],
           "access": "ro"
         }]
@@ -215,7 +212,7 @@ To categorically give yourself access to all your shares, you can use the below
       "src": ["autogroup:member"],
       "dst": ["autogroup:self"],
       "app": {
-        "tailscale.com/cap/tailfs": [{
+        "tailscale.com/cap/drive": [{
           "shares": ["*"],
           "access": "rw"
         }]
@@ -226,18 +223,18 @@ Whenever either you or anyone in the group "home" connects to the share, they co
 
 You can rename shares, for example you could rename the above share by running:
 
-  $ tailscale share rename docs newdocs
+  $ tailscale drive rename docs newdocs
 
 You can remove shares by name, for example you could remove the above share by running:
 
-  $ tailscale share remove newdocs
+  $ tailscale drive unshare newdocs
 
 You can get a list of currently published shares by running:
 
-  $ tailscale share list`
+  $ tailscale drive list`
 
-var shareLongHelpAs = `
+const shareLongHelpAs = `
 
 If you want a share to be accessed as a different user, you can use sudo to accomplish this. For example, to create the aforementioned share as "theuser", you could run:
 
-	$ sudo -u theuser tailscale share set docs /Users/theuser/Documents`
+  $ sudo -u theuser tailscale drive share docs /Users/theuser/Documents`

cmd/tailscale/cli/exitnode.go

@@ -9,44 +9,85 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"os"
 	"slices"
 	"strings"
 	"text/tabwriter"
 
 	"github.com/peterbourgon/ff/v3/ffcli"
 	xmaps "golang.org/x/exp/maps"
+	"tailscale.com/envknob"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
 )
 
-var exitNodeCmd = &ffcli.Command{
-	Name:       "exit-node",
-	ShortUsage: "exit-node [flags]",
-	ShortHelp:  "Show machines on your tailnet configured as exit nodes",
-	LongHelp:   "Show machines on your tailnet configured as exit nodes",
-	Subcommands: []*ffcli.Command{
-		{
-			Name:       "list",
-			ShortUsage: "exit-node list [flags]",
-			ShortHelp:  "Show exit nodes",
-			Exec:       runExitNodeList,
-			FlagSet: (func() *flag.FlagSet {
-				fs := newFlagSet("list")
-				fs.StringVar(&exitNodeArgs.filter, "filter", "", "filter exit nodes by country")
-				return fs
-			})(),
-		},
-	},
-	Exec: func(context.Context, []string) error {
-		return errors.New("exit-node subcommand required; run 'tailscale exit-node -h' for details")
-	},
+func exitNodeCmd() *ffcli.Command {
+	return &ffcli.Command{
+		Name:       "exit-node",
+		ShortUsage: "tailscale exit-node [flags]",
+		ShortHelp:  "Show machines on your tailnet configured as exit nodes",
+		Subcommands: append([]*ffcli.Command{
+			{
+				Name:       "list",
+				ShortUsage: "tailscale exit-node list [flags]",
+				ShortHelp:  "Show exit nodes",
+				Exec:       runExitNodeList,
+				FlagSet: (func() *flag.FlagSet {
+					fs := newFlagSet("list")
+					fs.StringVar(&exitNodeArgs.filter, "filter", "", "filter exit nodes by country")
+					return fs
+				})(),
+			},
+			{
+				Name:       "suggest",
+				ShortUsage: "tailscale exit-node suggest",
+				ShortHelp:  "Suggests the best available exit node",
+				Exec:       runExitNodeSuggest,
+			}},
+			(func() []*ffcli.Command {
+				if !envknob.UseWIPCode() {
+					return nil
+				}
+				return []*ffcli.Command{
+					{
+						Name:       "connect",
+						ShortUsage: "tailscale exit-node connect",
+						ShortHelp:  "Connect to most recently used exit node",
+						Exec:       exitNodeSetUse(true),
+					},
+					{
+						Name:       "disconnect",
+						ShortUsage: "tailscale exit-node disconnect",
+						ShortHelp:  "Disconnect from current exit node, if any",
+						Exec:       exitNodeSetUse(false),
+					},
+				}
+			})()...),
+	}
 }
 
 var exitNodeArgs struct {
 	filter string
 }
 
+func exitNodeSetUse(wantOn bool) func(ctx context.Context, args []string) error {
+	return func(ctx context.Context, args []string) error {
+		if len(args) > 0 {
+			return errors.New("unexpected non-flag arguments")
+		}
+		err := localClient.SetUseExitNode(ctx, wantOn)
+		if err != nil {
+			if !wantOn {
+				pref, err := localClient.GetPrefs(ctx)
+				if err == nil && pref.ExitNodeID == "" {
+					// Two processes concurrently turned it off.
+					return nil
+				}
+			}
+		}
+		return err
+	}
+}
+
 // runExitNodeList returns a formatted list of exit nodes for a tailnet.
 // If the exit node has location and priority data, only the highest
 // priority node for each city location is shown to the user.
@@ -70,7 +111,6 @@ func runExitNodeList(ctx context.Context, args []string) error {
 			// We only show exit nodes under the exit-node subcommand.
 			continue
 		}
-
 		peers = append(peers, ps)
 	}
 
@@ -84,24 +124,49 @@ func runExitNodeList(ctx context.Context, args []string) error {
 		return fmt.Errorf("no exit nodes found for %q", exitNodeArgs.filter)
 	}
 
-	w := tabwriter.NewWriter(os.Stdout, 10, 5, 5, ' ', 0)
+	w := tabwriter.NewWriter(Stdout, 10, 5, 5, ' ', 0)
 	defer w.Flush()
 	fmt.Fprintf(w, "\n %s\t%s\t%s\t%s\t%s\t", "IP", "HOSTNAME", "COUNTRY", "CITY", "STATUS")
 	for _, country := range filteredPeers.Countries {
 		for _, city := range country.Cities {
 			for _, peer := range city.Peers {
-
 				fmt.Fprintf(w, "\n %s\t%s\t%s\t%s\t%s\t", peer.TailscaleIPs[0], strings.Trim(peer.DNSName, "."), country.Name, city.Name, peerStatus(peer))
 			}
 		}
 	}
 	fmt.Fprintln(w)
 	fmt.Fprintln(w)
-	fmt.Fprintln(w, "# To use an exit node, use `tailscale set --exit-node=` followed by the hostname or IP")
-
+	fmt.Fprintln(w, "# To use an exit node, use `tailscale set --exit-node=` followed by the hostname or IP.")
+	if hasAnyExitNodeSuggestions(peers) {
+		fmt.Fprintln(w, "# To have Tailscale suggest an exit node, use `tailscale exit-node suggest`.")
+	}
 	return nil
 }
 
+// runExitNodeSuggest returns a suggested exit node ID to connect to and shows the chosen exit node tailcfg.StableNodeID.
+// If there are no derp based exit nodes to choose from or there is a failure in finding a suggestion, the command will return an error indicating so.
+func runExitNodeSuggest(ctx context.Context, args []string) error {
+	res, err := localClient.SuggestExitNode(ctx)
+	if err != nil {
+		return fmt.Errorf("suggest exit node: %w", err)
+	}
+	if res.ID == "" {
+		fmt.Println("No exit node suggestion is available.")
+		return nil
+	}
+	fmt.Printf("Suggested exit node: %v\nTo accept this suggestion, use `tailscale set --exit-node=%v`.\n", res.Name, res.ID)
+	return nil
+}
+
+func hasAnyExitNodeSuggestions(peers []*ipnstate.PeerStatus) bool {
+	for _, peer := range peers {
+		if peer.HasCap(tailcfg.NodeAttrSuggestExitNode) {
+			return true
+		}
+	}
+	return false
+}
+
 // peerStatus returns a string representing the current state of
 // a peer. If there is no notable state, a - is returned.
 func peerStatus(peer *ipnstate.PeerStatus) string {
@@ -137,46 +202,51 @@ type filteredCity struct {
 
 const noLocationData = "-"
 
+var noLocation = &tailcfg.Location{
+	Country:     noLocationData,
+	CountryCode: noLocationData,
+	City:        noLocationData,
+	CityCode:    noLocationData,
+}
+
 // filterFormatAndSortExitNodes filters and sorts exit nodes into
 // alphabetical order, by country, city and then by priority if
 // present.
 // If an exit node has location data, and the country has more than
-// once city, an `Any` city is added to the country that contains the
+// one city, an `Any` city is added to the country that contains the
 // highest priority exit node within that country.
 // For exit nodes without location data, their country fields are
 // defined as '-' to indicate that the data is not available.
 func filterFormatAndSortExitNodes(peers []*ipnstate.PeerStatus, filterBy string) filteredExitNodes {
+	// first get peers into some fixed order, as code below doesn't break ties
+	// and our input comes from a random range-over-map.
+	slices.SortFunc(peers, func(a, b *ipnstate.PeerStatus) int {
+		return strings.Compare(a.DNSName, b.DNSName)
+	})
+
 	countries := make(map[string]*filteredCountry)
 	cities := make(map[string]*filteredCity)
 	for _, ps := range peers {
-		if ps.Location == nil {
-			ps.Location = &tailcfg.Location{
-				Country:     noLocationData,
-				CountryCode: noLocationData,
-				City:        noLocationData,
-				CityCode:    noLocationData,
-			}
-		}
+		loc := cmp.Or(ps.Location, noLocation)
 
-		if filterBy != "" && ps.Location.Country != filterBy {
+		if filterBy != "" && loc.Country != filterBy {
 			continue
 		}
 
-		co, coOK := countries[ps.Location.CountryCode]
-		if !coOK {
+		co, ok := countries[loc.CountryCode]
+		if !ok {
 			co = &filteredCountry{
-				Name: ps.Location.Country,
+				Name: loc.Country,
 			}
-			countries[ps.Location.CountryCode] = co
-
+			countries[loc.CountryCode] = co
 		}
 
-		ci, ciOK := cities[ps.Location.CityCode]
-		if !ciOK {
+		ci, ok := cities[loc.CityCode]
+		if !ok {
 			ci = &filteredCity{
-				Name: ps.Location.City,
+				Name: loc.City,
 			}
-			cities[ps.Location.CityCode] = ci
+			cities[loc.CityCode] = ci
 			co.Cities = append(co.Cities, ci)
 		}
 		ci.Peers = append(ci.Peers, ps)
@@ -193,10 +263,10 @@ func filterFormatAndSortExitNodes(peers []*ipnstate.PeerStatus, filterBy string)
 			continue
 		}
 
-		var countryANYPeer []*ipnstate.PeerStatus
+		var countryAnyPeer []*ipnstate.PeerStatus
 		for _, city := range country.Cities {
 			sortPeersByPriority(city.Peers)
-			countryANYPeer = append(countryANYPeer, city.Peers...)
+			countryAnyPeer = append(countryAnyPeer, city.Peers...)
 			var reducedCityPeers []*ipnstate.PeerStatus
 			for i, peer := range city.Peers {
 				if i == 0 || peer.ExitNode {
@@ -208,7 +278,7 @@ func filterFormatAndSortExitNodes(peers []*ipnstate.PeerStatus, filterBy string)
 			city.Peers = reducedCityPeers
 		}
 		sortByCityName(country.Cities)
-		sortPeersByPriority(countryANYPeer)
+		sortPeersByPriority(countryAnyPeer)
 
 		if len(country.Cities) > 1 {
 			// For countries with more than one city, we want to return the
@@ -216,7 +286,7 @@ func filterFormatAndSortExitNodes(peers []*ipnstate.PeerStatus, filterBy string)
 			country.Cities = append([]*filteredCity{
 				{
 					Name:  "Any",
-					Peers: []*ipnstate.PeerStatus{countryANYPeer[0]},
+					Peers: []*ipnstate.PeerStatus{countryAnyPeer[0]},
 				},
 			}, country.Cities...)
 		}

cmd/tailscale/cli/file.go

@@ -38,18 +38,12 @@ import (
 
 var fileCmd = &ffcli.Command{
 	Name:       "file",
-	ShortUsage: "file <cp|get> ...",
+	ShortUsage: "tailscale file <cp|get> ...",
 	ShortHelp:  "Send or receive files",
 	Subcommands: []*ffcli.Command{
 		fileCpCmd,
 		fileGetCmd,
 	},
-	Exec: func(context.Context, []string) error {
-		// TODO(bradfitz): is there a better ffcli way to
-		// annotate subcommand-required commands that don't
-		// have an exec body of their own?
-		return errors.New("file subcommand required; run 'tailscale file -h' for details")
-	},
 }
 
 type countingReader struct {
@@ -65,7 +59,7 @@ func (c *countingReader) Read(buf []byte) (int, error) {
 
 var fileCpCmd = &ffcli.Command{
 	Name:       "cp",
-	ShortUsage: "file cp <files...> <target>:",
+	ShortUsage: "tailscale file cp <files...> <target>:",
 	ShortHelp:  "Copy file(s) to a host",
 	Exec:       runCp,
 	FlagSet: (func() *flag.FlagSet {
@@ -412,7 +406,7 @@ func (v *onConflict) Set(s string) error {
 
 var fileGetCmd = &ffcli.Command{
 	Name:       "get",
-	ShortUsage: "file get [--wait] [--verbose] [--conflict=(skip|overwrite|rename)] <target-directory>",
+	ShortUsage: "tailscale file get [--wait] [--verbose] [--conflict=(skip|overwrite|rename)] <target-directory>",
 	ShortHelp:  "Move files out of the Tailscale file inbox",
 	Exec:       runFileGet,
 	FlagSet: (func() *flag.FlagSet {
@@ -420,7 +414,7 @@ var fileGetCmd = &ffcli.Command{
 		fs.BoolVar(&getArgs.wait, "wait", false, "wait for a file to arrive if inbox is empty")
 		fs.BoolVar(&getArgs.loop, "loop", false, "run get in a loop, receiving files as they come in")
 		fs.BoolVar(&getArgs.verbose, "verbose", false, "verbose output")
-		fs.Var(&getArgs.conflict, "conflict", `behavior when a conflicting (same-named) file already exists in the target directory.
+		fs.Var(&getArgs.conflict, "conflict", "`behavior`"+` when a conflicting (same-named) file already exists in the target directory.
 	skip:       skip conflicting files: leave them in the taildrop inbox and print an error. get any non-conflicting files
 	overwrite:  overwrite existing file
 	rename:     write to a new number-suffixed filename`)
@@ -560,7 +554,7 @@ func runFileGetOneBatch(ctx context.Context, dir string) []error {
 
 func runFileGet(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: file get <target-directory>")
+		return errors.New("usage: tailscale file get <target-directory>")
 	}
 	log.SetFlags(0)
 

cmd/tailscale/cli/funnel.go

@@ -8,7 +8,6 @@ import (
 	"flag"
 	"fmt"
 	"net"
-	"os"
 	"strconv"
 	"strings"
 
@@ -37,9 +36,9 @@ func newFunnelCommand(e *serveEnv) *ffcli.Command {
 		Name:      "funnel",
 		ShortHelp: "Turn on/off Funnel service",
 		ShortUsage: strings.Join([]string{
-			"funnel <serve-port> {on|off}",
-			"funnel status [--json]",
-		}, "\n  "),
+			"tailscale funnel <serve-port> {on|off}",
+			"tailscale funnel status [--json]",
+		}, "\n"),
 		LongHelp: strings.Join([]string{
 			"Funnel allows you to publish a 'tailscale serve'",
 			"server publicly, open to the entire internet.",
@@ -47,17 +46,16 @@ func newFunnelCommand(e *serveEnv) *ffcli.Command {
 			"Turning off Funnel only turns off serving to the internet.",
 			"It does not affect serving to your tailnet.",
 		}, "\n"),
-		Exec:      e.runFunnel,
-		UsageFunc: usageFunc,
+		Exec: e.runFunnel,
 		Subcommands: []*ffcli.Command{
 			{
-				Name:      "status",
-				Exec:      e.runServeStatus,
-				ShortHelp: "show current serve/funnel status",
+				Name:       "status",
+				Exec:       e.runServeStatus,
+				ShortUsage: "tailscale funnel status [--json]",
+				ShortHelp:  "Show current serve/funnel status",
 				FlagSet: e.newFlags("funnel-status", func(fs *flag.FlagSet) {
 					fs.BoolVar(&e.json, "json", false, "output JSON")
 				}),
-				UsageFunc: usageFunc,
 			},
 		},
 	}
@@ -169,10 +167,10 @@ func printFunnelWarning(sc *ipn.ServeConfig) {
 		p, _ := strconv.ParseUint(portStr, 10, 16)
 		if _, ok := sc.TCP[uint16(p)]; !ok {
 			warn = true
-			fmt.Fprintf(os.Stderr, "\nWarning: funnel=on for %s, but no serve config\n", hp)
+			fmt.Fprintf(Stderr, "\nWarning: funnel=on for %s, but no serve config\n", hp)
 		}
 	}
 	if warn {
-		fmt.Fprintf(os.Stderr, "         run: `tailscale serve --help` to see how to configure handlers\n")
+		fmt.Fprintf(Stderr, "         run: `tailscale serve --help` to see how to configure handlers\n")
 	}
 }

cmd/tailscale/cli/id-token.go

@@ -12,14 +12,14 @@ import (
 
 var idTokenCmd = &ffcli.Command{
 	Name:       "id-token",
-	ShortUsage: "id-token <aud>",
-	ShortHelp:  "fetch an OIDC id-token for the Tailscale machine",
+	ShortUsage: "tailscale id-token <aud>",
+	ShortHelp:  "Fetch an OIDC id-token for the Tailscale machine",
 	Exec:       runIDToken,
 }
 
 func runIDToken(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: id-token <aud>")
+		return errors.New("usage: tailscale id-token <aud>")
 	}
 
 	tr, err := localClient.IDToken(ctx, args[0])

cmd/tailscale/cli/ip.go

@@ -16,7 +16,7 @@ import (
 
 var ipCmd = &ffcli.Command{
 	Name:       "ip",
-	ShortUsage: "ip [-1] [-4] [-6] [peer hostname or ip address]",
+	ShortUsage: "tailscale ip [-1] [-4] [-6] [peer hostname or ip address]",
 	ShortHelp:  "Show Tailscale IP addresses",
 	LongHelp:   "Show Tailscale IP addresses for peer. Peer defaults to the current machine.",
 	Exec:       runIP,

cmd/tailscale/cli/licenses.go

@@ -12,7 +12,7 @@ import (
 
 var licensesCmd = &ffcli.Command{
 	Name:       "licenses",
-	ShortUsage: "licenses",
+	ShortUsage: "tailscale licenses",
 	ShortHelp:  "Get open source license information",
 	LongHelp:   "Get open source license information",
 	Exec:       runLicenses,

cmd/tailscale/cli/login.go

@@ -14,11 +14,10 @@ var loginArgs upArgsT
 
 var loginCmd = &ffcli.Command{
 	Name:       "login",
-	ShortUsage: "login [flags]",
+	ShortUsage: "tailscale login [flags]",
 	ShortHelp:  "Log in to a Tailscale account",
 	LongHelp: `"tailscale login" logs this machine in to your Tailscale network.
 This command is currently in alpha and may change in the future.`,
-	UsageFunc: usageFunc,
 	FlagSet: func() *flag.FlagSet {
 		return newUpFlagSet(effectiveGOOS(), &loginArgs, "login")
 	}(),

cmd/tailscale/cli/logout.go

@@ -13,7 +13,7 @@ import (
 
 var logoutCmd = &ffcli.Command{
 	Name:       "logout",
-	ShortUsage: "logout [flags]",
+	ShortUsage: "tailscale logout",
 	ShortHelp:  "Disconnect from Tailscale and expire current node key",
 
 	LongHelp: strings.TrimSpace(`

cmd/tailscale/cli/nc.go

@@ -16,7 +16,7 @@ import (
 
 var ncCmd = &ffcli.Command{
 	Name:       "nc",
-	ShortUsage: "nc <hostname-or-IP> <port>",
+	ShortUsage: "tailscale nc <hostname-or-IP> <port>",
 	ShortHelp:  "Connect to a port on a host, connected to stdin/stdout",
 	Exec:       runNC,
 }
@@ -33,7 +33,7 @@ func runNC(ctx context.Context, args []string) error {
 	}
 
 	if len(args) != 2 {
-		return errors.New("usage: nc <hostname-or-IP> <port>")
+		return errors.New("usage: tailscale nc <hostname-or-IP> <port>")
 	}
 
 	hostOrIP, portStr := args[0], args[1]

cmd/tailscale/cli/netcheck.go

@@ -28,7 +28,7 @@ import (
 
 var netcheckCmd = &ffcli.Command{
 	Name:       "netcheck",
-	ShortUsage: "netcheck",
+	ShortUsage: "tailscale netcheck",
 	ShortHelp:  "Print an analysis of local network conditions",
 	Exec:       runNetcheck,
 	FlagSet: (func() *flag.FlagSet {

cmd/tailscale/cli/network-lock.go

@@ -17,8 +17,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/mattn/go-colorable"
-	"github.com/mattn/go-isatty"
 	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tka"
@@ -28,7 +26,7 @@ import (
 
 var netlockCmd = &ffcli.Command{
 	Name:       "lock",
-	ShortUsage: "lock <sub-command> <arguments>",
+	ShortUsage: "tailscale lock <subcommand> [arguments...]",
 	ShortHelp:  "Manage tailnet lock",
 	LongHelp:   "Manage tailnet lock",
 	Subcommands: []*ffcli.Command{
@@ -51,6 +49,9 @@ func runNetworkLockNoSubcommand(ctx context.Context, args []string) error {
 	if len(args) >= 2 && args[0] == "tskey-wrap" {
 		return runTskeyWrapCmd(ctx, args[1:])
 	}
+	if len(args) > 0 {
+		return fmt.Errorf("tailscale lock: unknown subcommand: %s", args[0])
+	}
 
 	return runNetworkLockStatus(ctx, args)
 }
@@ -63,7 +64,7 @@ var nlInitArgs struct {
 
 var nlInitCmd = &ffcli.Command{
 	Name:       "init",
-	ShortUsage: "init [--gen-disablement-for-support] --gen-disablements N <trusted-key>...",
+	ShortUsage: "tailscale lock init [--gen-disablement-for-support] --gen-disablements N <trusted-key>...",
 	ShortHelp:  "Initialize tailnet lock",
 	LongHelp: strings.TrimSpace(`
 
@@ -150,7 +151,7 @@ func runNetworkLockInit(ctx context.Context, args []string) error {
 	}
 
 	fmt.Printf("%d disablement secrets have been generated and are printed below. Take note of them now, they WILL NOT be shown again.\n", nlInitArgs.numDisablements)
-	for i := 0; i < nlInitArgs.numDisablements; i++ {
+	for range nlInitArgs.numDisablements {
 		var secret [32]byte
 		if _, err := rand.Read(secret[:]); err != nil {
 			return err
@@ -185,7 +186,7 @@ var nlStatusArgs struct {
 
 var nlStatusCmd = &ffcli.Command{
 	Name:       "status",
-	ShortUsage: "status",
+	ShortUsage: "tailscale lock status",
 	ShortHelp:  "Outputs the state of tailnet lock",
 	LongHelp:   "Outputs the state of tailnet lock",
 	Exec:       runNetworkLockStatus,
@@ -197,6 +198,10 @@ var nlStatusCmd = &ffcli.Command{
 }
 
 func runNetworkLockStatus(ctx context.Context, args []string) error {
+	if len(args) > 0 {
+		return fmt.Errorf("tailscale lock status: unexpected argument")
+	}
+
 	st, err := localClient.NetworkLockStatus(ctx)
 	if err != nil {
 		return fixTailscaledConnectError(err)
@@ -282,7 +287,7 @@ func runNetworkLockStatus(ctx context.Context, args []string) error {
 
 var nlAddCmd = &ffcli.Command{
 	Name:       "add",
-	ShortUsage: "add <public-key>...",
+	ShortUsage: "tailscale lock add <public-key>...",
 	ShortHelp:  "Adds one or more trusted signing keys to tailnet lock",
 	LongHelp:   "Adds one or more trusted signing keys to tailnet lock",
 	Exec: func(ctx context.Context, args []string) error {
@@ -296,7 +301,7 @@ var nlRemoveArgs struct {
 
 var nlRemoveCmd = &ffcli.Command{
 	Name:       "remove",
-	ShortUsage: "remove [--re-sign=false] <public-key>...",
+	ShortUsage: "tailscale lock remove [--re-sign=false] <public-key>...",
 	ShortHelp:  "Removes one or more trusted signing keys from tailnet lock",
 	LongHelp:   "Removes one or more trusted signing keys from tailnet lock",
 	Exec:       runNetworkLockRemove,
@@ -437,7 +442,7 @@ func runNetworkLockModify(ctx context.Context, addArgs, removeArgs []string) err
 
 var nlSignCmd = &ffcli.Command{
 	Name:       "sign",
-	ShortUsage: "sign <node-key> [<rotation-key>] or sign <auth-key>",
+	ShortUsage: "tailscale lock sign <node-key> [<rotation-key>] or sign <auth-key>",
 	ShortHelp:  "Signs a node or pre-approved auth key",
 	LongHelp: `Either:
   - signs a node key and transmits the signature to the coordination server, or
@@ -456,7 +461,7 @@ func runNetworkLockSign(ctx context.Context, args []string) error {
 	)
 
 	if len(args) == 0 || len(args) > 2 {
-		return errors.New("usage: lock sign <node-key> [<rotation-key>]")
+		return errors.New("usage: tailscale lock sign <node-key> [<rotation-key>]")
 	}
 	if err := nodeKey.UnmarshalText([]byte(args[0])); err != nil {
 		return fmt.Errorf("decoding node-key: %w", err)
@@ -471,17 +476,17 @@ func runNetworkLockSign(ctx context.Context, args []string) error {
 	// Provide a better help message for when someone clicks through the signing flow
 	// on the wrong device.
 	if err != nil && strings.Contains(err.Error(), "this node is not trusted by network lock") {
-		fmt.Fprintln(os.Stderr, "Error: Signing is not available on this device because it does not have a trusted tailnet lock key.")
-		fmt.Fprintln(os.Stderr)
-		fmt.Fprintln(os.Stderr, "Try again on a signing device instead. Tailnet admins can see signing devices on the admin panel.")
-		fmt.Fprintln(os.Stderr)
+		fmt.Fprintln(Stderr, "Error: Signing is not available on this device because it does not have a trusted tailnet lock key.")
+		fmt.Fprintln(Stderr)
+		fmt.Fprintln(Stderr, "Try again on a signing device instead. Tailnet admins can see signing devices on the admin panel.")
+		fmt.Fprintln(Stderr)
 	}
 	return err
 }
 
 var nlDisableCmd = &ffcli.Command{
 	Name:       "disable",
-	ShortUsage: "disable <disablement-secret>",
+	ShortUsage: "tailscale lock disable <disablement-secret>",
 	ShortHelp:  "Consumes a disablement secret to shut down tailnet lock for the tailnet",
 	LongHelp: strings.TrimSpace(`
 
@@ -503,14 +508,14 @@ func runNetworkLockDisable(ctx context.Context, args []string) error {
 		return err
 	}
 	if len(secrets) != 1 {
-		return errors.New("usage: lock disable <disablement-secret>")
+		return errors.New("usage: tailscale lock disable <disablement-secret>")
 	}
 	return localClient.NetworkLockDisable(ctx, secrets[0])
 }
 
 var nlLocalDisableCmd = &ffcli.Command{
 	Name:       "local-disable",
-	ShortUsage: "local-disable",
+	ShortUsage: "tailscale lock local-disable",
 	ShortHelp:  "Disables tailnet lock for this node only",
 	LongHelp: strings.TrimSpace(`
 
@@ -532,7 +537,7 @@ func runNetworkLockLocalDisable(ctx context.Context, args []string) error {
 
 var nlDisablementKDFCmd = &ffcli.Command{
 	Name:       "disablement-kdf",
-	ShortUsage: "disablement-kdf <hex-encoded-disablement-secret>",
+	ShortUsage: "tailscale lock disablement-kdf <hex-encoded-disablement-secret>",
 	ShortHelp:  "Computes a disablement value from a disablement secret (advanced users only)",
 	LongHelp:   "Computes a disablement value from a disablement secret (advanced users only)",
 	Exec:       runNetworkLockDisablementKDF,
@@ -540,7 +545,7 @@ var nlDisablementKDFCmd = &ffcli.Command{
 
 func runNetworkLockDisablementKDF(ctx context.Context, args []string) error {
 	if len(args) != 1 {
-		return errors.New("usage: lock disablement-kdf <hex-encoded-disablement-secret>")
+		return errors.New("usage: tailscale lock disablement-kdf <hex-encoded-disablement-secret>")
 	}
 	secret, err := hex.DecodeString(args[0])
 	if err != nil {
@@ -557,7 +562,7 @@ var nlLogArgs struct {
 
 var nlLogCmd = &ffcli.Command{
 	Name:       "log",
-	ShortUsage: "log [--limit N]",
+	ShortUsage: "tailscale lock log [--limit N]",
 	ShortHelp:  "List changes applied to tailnet lock",
 	LongHelp:   "List changes applied to tailnet lock",
 	Exec:       runNetworkLockLog,
@@ -643,20 +648,19 @@ func runNetworkLockLog(ctx context.Context, args []string) error {
 		return fixTailscaledConnectError(err)
 	}
 	if nlLogArgs.json {
-		enc := json.NewEncoder(os.Stdout)
+		enc := json.NewEncoder(Stdout)
 		enc.SetIndent("", "  ")
 		return enc.Encode(updates)
 	}
 
-	useColor := isatty.IsTerminal(os.Stdout.Fd())
+	out, useColor := colorableOutput()
 
-	stdOut := colorable.NewColorableStdout()
 	for _, update := range updates {
 		stanza, err := nlDescribeUpdate(update, useColor)
 		if err != nil {
 			return err
 		}
-		fmt.Fprintln(stdOut, stanza)
+		fmt.Fprintln(out, stanza)
 	}
 	return nil
 }
@@ -722,7 +726,7 @@ var nlRevokeKeysArgs struct {
 
 var nlRevokeKeysCmd = &ffcli.Command{
 	Name:       "revoke-keys",
-	ShortUsage: "revoke-keys <tailnet-lock-key>...\n  revoke-keys [--cosign] [--finish] <recovery-blob>",
+	ShortUsage: "tailscale lock revoke-keys <tailnet-lock-key>...\n  revoke-keys [--cosign] [--finish] <recovery-blob>",
 	ShortHelp:  "Revoke compromised tailnet-lock keys",
 	LongHelp: `Retroactively revoke the specified tailnet lock keys (tlpub:abc).
 

cmd/tailscale/cli/ping.go

@@ -23,7 +23,7 @@ import (
 
 var pingCmd = &ffcli.Command{
 	Name:       "ping",
-	ShortUsage: "ping <hostname-or-IP>",
+	ShortUsage: "tailscale ping <hostname-or-IP>",
 	ShortHelp:  "Ping a host at the Tailscale layer, see how it routed",
 	LongHelp: strings.TrimSpace(`
 
@@ -95,7 +95,7 @@ func runPing(ctx context.Context, args []string) error {
 	}
 
 	if len(args) != 1 || args[0] == "" {
-		return errors.New("usage: ping <hostname-or-IP>")
+		return errors.New("usage: tailscale ping <hostname-or-IP>")
 	}
 	var ip string
 

cmd/tailscale/cli/serve_legacy.go

@@ -44,13 +44,13 @@ func newServeLegacyCommand(e *serveEnv) *ffcli.Command {
 		Name:      "serve",
 		ShortHelp: "Serve content and local servers",
 		ShortUsage: strings.Join([]string{
-			"serve http:<port> <mount-point> <source> [off]",
-			"serve https:<port> <mount-point> <source> [off]",
-			"serve tcp:<port> tcp://localhost:<local-port> [off]",
-			"serve tls-terminated-tcp:<port> tcp://localhost:<local-port> [off]",
-			"serve status [--json]",
-			"serve reset",
-		}, "\n  "),
+			"tailscale serve http:<port> <mount-point> <source> [off]",
+			"tailscale serve https:<port> <mount-point> <source> [off]",
+			"tailscale serve tcp:<port> tcp://localhost:<local-port> [off]",
+			"tailscale serve tls-terminated-tcp:<port> tcp://localhost:<local-port> [off]",
+			"tailscale serve status [--json]",
+			"tailscale serve reset",
+		}, "\n"),
 		LongHelp: strings.TrimSpace(`
 *** BETA; all of this is subject to change ***
 
@@ -91,24 +91,21 @@ EXAMPLES
     local plaintext server on port 80:
     $ tailscale serve tls-terminated-tcp:443 tcp://localhost:80
 `),
-		Exec:      e.runServe,
-		UsageFunc: usageFunc,
+		Exec: e.runServe,
 		Subcommands: []*ffcli.Command{
 			{
 				Name:      "status",
 				Exec:      e.runServeStatus,
-				ShortHelp: "show current serve/funnel status",
+				ShortHelp: "Show current serve/funnel status",
 				FlagSet: e.newFlags("serve-status", func(fs *flag.FlagSet) {
 					fs.BoolVar(&e.json, "json", false, "output JSON")
 				}),
-				UsageFunc: usageFunc,
 			},
 			{
 				Name:      "reset",
 				Exec:      e.runServeReset,
-				ShortHelp: "reset current serve/funnel config",
+				ShortHelp: "Reset current serve/funnel config",
 				FlagSet:   e.newFlags("serve-reset", nil),
-				UsageFunc: usageFunc,
 			},
 		},
 	}
@@ -197,7 +194,7 @@ func (e *serveEnv) getLocalClientStatusWithoutPeers(ctx context.Context) (*ipnst
 	}
 	description, ok := isRunningOrStarting(st)
 	if !ok {
-		fmt.Fprintf(os.Stderr, "%s\n", description)
+		fmt.Fprintf(Stderr, "%s\n", description)
 		os.Exit(1)
 	}
 	if st.Self == nil {
@@ -251,7 +248,7 @@ func (e *serveEnv) runServe(ctx context.Context, args []string) error {
 	turnOff := "off" == args[len(args)-1]
 
 	if len(args) < 2 || ((srcType == "https" || srcType == "http") && !turnOff && len(args) < 3) {
-		fmt.Fprintf(os.Stderr, "error: invalid number of arguments\n\n")
+		fmt.Fprintf(Stderr, "error: invalid number of arguments\n\n")
 		return errHelp
 	}
 
@@ -290,8 +287,8 @@ func (e *serveEnv) runServe(ctx context.Context, args []string) error {
 		}
 		return e.handleTCPServe(ctx, srcType, srcPort, args[1])
 	default:
-		fmt.Fprintf(os.Stderr, "error: invalid serve type %q\n", srcType)
-		fmt.Fprint(os.Stderr, "must be one of: http:<port>, https:<port>, tcp:<port> or tls-terminated-tcp:<port>\n\n", srcType)
+		fmt.Fprintf(Stderr, "error: invalid serve type %q\n", srcType)
+		fmt.Fprint(Stderr, "must be one of: http:<port>, https:<port>, tcp:<port> or tls-terminated-tcp:<port>\n\n", srcType)
 		return errHelp
 	}
 }
@@ -327,13 +324,13 @@ func (e *serveEnv) handleWebServe(ctx context.Context, srvPort uint16, useTLS bo
 			return fmt.Errorf("path serving is not supported if sandboxed on macOS")
 		}
 		if !filepath.IsAbs(source) {
-			fmt.Fprintf(os.Stderr, "error: path must be absolute\n\n")
+			fmt.Fprintf(Stderr, "error: path must be absolute\n\n")
 			return errHelp
 		}
 		source = filepath.Clean(source)
 		fi, err := os.Stat(source)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "error: invalid path: %v\n\n", err)
+			fmt.Fprintf(Stderr, "error: invalid path: %v\n\n", err)
 			return errHelp
 		}
 		if fi.IsDir() && !strings.HasSuffix(mount, "/") {
@@ -357,7 +354,7 @@ func (e *serveEnv) handleWebServe(ctx context.Context, srvPort uint16, useTLS bo
 		return err
 	}
 	if sc.IsTCPForwardingOnPort(srvPort) {
-		fmt.Fprintf(os.Stderr, "error: cannot serve web; already serving TCP\n")
+		fmt.Fprintf(Stderr, "error: cannot serve web; already serving TCP\n")
 		return errHelp
 	}
 
@@ -390,7 +387,7 @@ func isProxyTarget(source string) bool {
 // allNumeric reports whether s only comprises of digits
 // and has at least one digit.
 func allNumeric(s string) bool {
-	for i := 0; i < len(s); i++ {
+	for i := range len(s) {
 		if s[i] < '0' || s[i] > '9' {
 			return false
 		}
@@ -512,18 +509,18 @@ func (e *serveEnv) handleTCPServe(ctx context.Context, srcType string, srcPort u
 	case "tls-terminated-tcp":
 		terminateTLS = true
 	default:
-		fmt.Fprintf(os.Stderr, "error: invalid TCP source %q\n\n", dest)
+		fmt.Fprintf(Stderr, "error: invalid TCP source %q\n\n", dest)
 		return errHelp
 	}
 
 	dstURL, err := url.Parse(dest)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "error: invalid TCP source %q: %v\n\n", dest, err)
+		fmt.Fprintf(Stderr, "error: invalid TCP source %q: %v\n\n", dest, err)
 		return errHelp
 	}
 	host, dstPortStr, err := net.SplitHostPort(dstURL.Host)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "error: invalid TCP source %q: %v\n\n", dest, err)
+		fmt.Fprintf(Stderr, "error: invalid TCP source %q: %v\n\n", dest, err)
 		return errHelp
 	}
 
@@ -531,13 +528,13 @@ func (e *serveEnv) handleTCPServe(ctx context.Context, srcType string, srcPort u
 	case "localhost", "127.0.0.1":
 		// ok
 	default:
-		fmt.Fprintf(os.Stderr, "error: invalid TCP source %q\n", dest)
-		fmt.Fprint(os.Stderr, "must be one of: localhost or 127.0.0.1\n\n", dest)
+		fmt.Fprintf(Stderr, "error: invalid TCP source %q\n", dest)
+		fmt.Fprint(Stderr, "must be one of: localhost or 127.0.0.1\n\n", dest)
 		return errHelp
 	}
 
 	if p, err := strconv.ParseUint(dstPortStr, 10, 16); p == 0 || err != nil {
-		fmt.Fprintf(os.Stderr, "error: invalid port %q\n\n", dstPortStr)
+		fmt.Fprintf(Stderr, "error: invalid port %q\n\n", dstPortStr)
 		return errHelp
 	}
 
@@ -804,10 +801,10 @@ func (e *serveEnv) enableFeatureInteractive(ctx context.Context, feature string,
 		return nil // already enabled
 	}
 	if info.Text != "" {
-		fmt.Fprintln(os.Stdout, "\n"+info.Text)
+		fmt.Fprintln(Stdout, "\n"+info.Text)
 	}
 	if info.URL != "" {
-		fmt.Fprintln(os.Stdout, "\n         "+info.URL+"\n")
+		fmt.Fprintln(Stdout, "\n         "+info.URL+"\n")
 	}
 	if !info.ShouldWait {
 		e.lc.IncrementCounter(ctx, fmt.Sprintf("%s_not_awaiting_enablement", feature), 1)
@@ -852,7 +849,7 @@ func (e *serveEnv) enableFeatureInteractive(ctx context.Context, feature string,
 			}
 			if gotAll {
 				e.lc.IncrementCounter(ctx, fmt.Sprintf("%s_enabled", feature), 1)
-				fmt.Fprintln(os.Stdout, "Success.")
+				fmt.Fprintln(Stdout, "Success.")
 				return nil
 			}
 		}

cmd/tailscale/cli/serve_legacy_test.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -54,6 +55,9 @@ func TestCleanMountPoint(t *testing.T) {
 }
 
 func TestServeConfigMutations(t *testing.T) {
+	tstest.Replace(t, &Stderr, io.Discard)
+	tstest.Replace(t, &Stdout, io.Discard)
+
 	// Stateful mutations, starting from an empty config.
 	type step struct {
 		command []string                       // serve args; nil means no command to run (only reset)
@@ -706,6 +710,7 @@ func TestServeConfigMutations(t *testing.T) {
 			lc:          lc,
 			testFlagOut: &flagOut,
 			testStdout:  &stdout,
+			testStderr:  io.Discard,
 		}
 		lastCount := lc.setCount
 		var cmd *ffcli.Command
@@ -717,6 +722,10 @@ func TestServeConfigMutations(t *testing.T) {
 			cmd = newServeLegacyCommand(e)
 			args = st.command
 		}
+		if cmd.FlagSet == nil {
+			cmd.FlagSet = flag.NewFlagSet(cmd.Name, flag.ContinueOnError)
+			cmd.FlagSet.SetOutput(Stdout)
+		}
 		err := cmd.ParseAndRun(context.Background(), args)
 		if flagOut.Len() > 0 {
 			t.Logf("flag package output: %q", flagOut.Bytes())
@@ -750,6 +759,9 @@ func TestServeConfigMutations(t *testing.T) {
 }
 
 func TestVerifyFunnelEnabled(t *testing.T) {
+	tstest.Replace(t, &Stderr, io.Discard)
+	tstest.Replace(t, &Stdout, io.Discard)
+
 	lc := &fakeLocalServeClient{}
 	var stdout bytes.Buffer
 	var flagOut bytes.Buffer
@@ -757,6 +769,7 @@ func TestVerifyFunnelEnabled(t *testing.T) {
 		lc:          lc,
 		testFlagOut: &flagOut,
 		testStdout:  &stdout,
+		testStderr:  io.Discard,
 	}
 
 	tests := []struct {

cmd/tailscale/cli/serve_v2.go

@@ -110,10 +110,10 @@ func newServeV2Command(e *serveEnv, subcmd serveMode) *ffcli.Command {
 		Name:      info.Name,
 		ShortHelp: info.ShortHelp,
 		ShortUsage: strings.Join([]string{
-			fmt.Sprintf("%s <target>", info.Name),
-			fmt.Sprintf("%s status [--json]", info.Name),
-			fmt.Sprintf("%s reset", info.Name),
-		}, "\n  "),
+			fmt.Sprintf("tailscale %s <target>", info.Name),
+			fmt.Sprintf("tailscale %s status [--json]", info.Name),
+			fmt.Sprintf("tailscale %s reset", info.Name),
+		}, "\n"),
 		LongHelp: info.LongHelp + fmt.Sprintf(strings.TrimSpace(serveHelpCommon), info.Name),
 		Exec:     e.runServeCombined(subcmd),
 
@@ -131,20 +131,20 @@ func newServeV2Command(e *serveEnv, subcmd serveMode) *ffcli.Command {
 		UsageFunc: usageFuncNoDefaultValues,
 		Subcommands: []*ffcli.Command{
 			{
-				Name:      "status",
-				Exec:      e.runServeStatus,
-				ShortHelp: "view current proxy configuration",
+				Name:       "status",
+				ShortUsage: "tailscale " + info.Name + " status [--json]",
+				Exec:       e.runServeStatus,
+				ShortHelp:  "View current " + info.Name + " configuration",
 				FlagSet: e.newFlags("serve-status", func(fs *flag.FlagSet) {
 					fs.BoolVar(&e.json, "json", false, "output JSON")
 				}),
-				UsageFunc: usageFunc,
 			},
 			{
-				Name:      "reset",
-				ShortHelp: "reset current serve/funnel config",
-				Exec:      e.runServeReset,
-				FlagSet:   e.newFlags("serve-reset", nil),
-				UsageFunc: usageFunc,
+				Name:       "reset",
+				ShortUsage: "tailscale " + info.Name + " reset",
+				ShortHelp:  "Reset current " + info.Name + " config",
+				Exec:       e.runServeReset,
+				FlagSet:    e.newFlags("serve-reset", nil),
 			},
 		},
 	}
@@ -497,9 +497,9 @@ func (e *serveEnv) applyWebServe(sc *ipn.ServeConfig, dnsName string, srvPort ui
 		}
 		h.Text = text
 	case filepath.IsAbs(target):
-		if version.IsSandboxedMacOS() {
-			// don't allow path serving for now on macOS (2022-11-15)
-			return errors.New("path serving is not supported if sandboxed on macOS")
+		if version.IsMacAppStore() || version.IsMacSys() {
+			// The Tailscale network extension cannot serve arbitrary paths on macOS due to sandbox restrictions (2024-03-26)
+			return errors.New("Path serving is not supported on macOS due to sandbox restrictions. To use Tailscale Serve on macOS, switch to the open-source tailscaled distribution. See https://tailscale.com/kb/1065/macos-variants for more information.")
 		}
 
 		target = filepath.Clean(target)
@@ -823,12 +823,12 @@ func (e *serveEnv) stdout() io.Writer {
 	if e.testStdout != nil {
 		return e.testStdout
 	}
-	return os.Stdout
+	return Stdout
 }
 
 func (e *serveEnv) stderr() io.Writer {
 	if e.testStderr != nil {
 		return e.testStderr
 	}
-	return os.Stderr
+	return Stderr
 }

cmd/tailscale/cli/set.go

@@ -25,7 +25,7 @@ import (
 
 var setCmd = &ffcli.Command{
 	Name:       "set",
-	ShortUsage: "set [flags]",
+	ShortUsage: "tailscale set [flags]",
 	ShortHelp:  "Change specified preferences",
 	LongHelp: `"tailscale set" allows changing specific preferences.
 

cmd/tailscale/cli/ssh.go

@@ -26,7 +26,7 @@ import (
 
 var sshCmd = &ffcli.Command{
 	Name:       "ssh",
-	ShortUsage: "ssh [user@]<host> [args...]",
+	ShortUsage: "tailscale ssh [user@]<host> [args...]",
 	ShortHelp:  "SSH to a Tailscale machine",
 	LongHelp: strings.TrimSpace(`
 
@@ -52,7 +52,7 @@ func runSSH(ctx context.Context, args []string) error {
 		return errors.New("The 'tailscale ssh' subcommand is not available on macOS builds distributed through the App Store or TestFlight.\nInstall the Standalone variant of Tailscale (download it from https://pkgs.tailscale.com), or use the regular 'ssh' client instead.")
 	}
 	if len(args) == 0 {
-		return errors.New("usage: ssh [user@]<host>")
+		return errors.New("usage: tailscale ssh [user@]<host>")
 	}
 	arg, argRest := args[0], args[1:]
 	username, host, ok := strings.Cut(arg, "@")
@@ -106,10 +106,8 @@ func runSSH(ctx context.Context, args []string) error {
 		"-o", "CanonicalizeHostname no", // https://github.com/tailscale/tailscale/issues/10348
 	)
 
-	// TODO(bradfitz): nc is currently broken on macOS:
-	// https://github.com/tailscale/tailscale/issues/4529
-	// So don't use it for now. MagicDNS is usually working on macOS anyway
-	// and they're not in userspace mode, so 'nc' isn't very useful.
+	// MagicDNS is usually working on macOS anyway and they're not in userspace
+	// mode, so 'nc' isn't very useful.
 	if runtime.GOOS != "darwin" {
 		socketArg := ""
 		if rootArgs.socket != "" && rootArgs.socket != paths.DefaultTailscaledSocket() {

cmd/tailscale/cli/status.go

@@ -29,7 +29,7 @@ import (
 
 var statusCmd = &ffcli.Command{
 	Name:       "status",
-	ShortUsage: "status [--active] [--web] [--json]",
+	ShortUsage: "tailscale status [--active] [--web] [--json]",
 	ShortHelp:  "Show state of tailscaled and its connections",
 	LongHelp: strings.TrimSpace(`
 

cmd/tailscale/cli/switch.go

@@ -17,26 +17,22 @@ import (
 )
 
 var switchCmd = &ffcli.Command{
-	Name:      "switch",
-	ShortHelp: "Switches to a different Tailscale account",
+	Name:       "switch",
+	ShortUsage: "tailscale switch <id>",
+	ShortHelp:  "Switches to a different Tailscale account",
+	LongHelp: `"tailscale switch" switches between logged in accounts. You can
+use the ID that's returned from 'tailnet switch -list'
+to pick which profile you want to switch to. Alternatively, you
+can use the Tailnet or the account names to switch as well.
+
+This command is currently in alpha and may change in the future.`,
+
 	FlagSet: func() *flag.FlagSet {
 		fs := flag.NewFlagSet("switch", flag.ExitOnError)
 		fs.BoolVar(&switchArgs.list, "list", false, "list available accounts")
 		return fs
 	}(),
 	Exec: switchProfile,
-	UsageFunc: func(*ffcli.Command) string {
-		return `USAGE
-  switch <id>
-  switch --list
-
-"tailscale switch" switches between logged in accounts. You can
-use the ID that's returned from 'tailnet switch -list'
-to pick which profile you want to switch to. Alternatively, you
-can use the Tailnet or the account names to switch as well.
-
-This command is currently in alpha and may change in the future.`
-	},
 }
 
 var switchArgs struct {
@@ -48,7 +44,7 @@ func listProfiles(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
-	tw := tabwriter.NewWriter(os.Stdout, 2, 2, 2, ' ', 0)
+	tw := tabwriter.NewWriter(Stdout, 2, 2, 2, ' ', 0)
 	defer tw.Flush()
 	printRow := func(vals ...string) {
 		fmt.Fprintln(tw, strings.Join(vals, "\t"))

cmd/tailscale/cli/up.go

@@ -44,7 +44,7 @@ import (
 
 var upCmd = &ffcli.Command{
 	Name:       "up",
-	ShortUsage: "up [flags]",
+	ShortUsage: "tailscale up [flags]",
 	ShortHelp:  "Connect to Tailscale, logging in if needed",
 
 	LongHelp: strings.TrimSpace(`
@@ -496,11 +496,23 @@ func runUp(ctx context.Context, cmd string, args []string, upArgs upArgsT) (retE
 	running := make(chan bool, 1) // gets value once in state ipn.Running
 	pumpErr := make(chan error, 1)
 
-	var printed bool // whether we've yet printed anything to stdout or stderr
-	var loginOnce sync.Once
-	startLoginInteractive := func() { loginOnce.Do(func() { localClient.StartLoginInteractive(ctx) }) }
+	// localAPIMu should be held while doing mutable LocalAPI calls
+	// to the backend. In particular, it prevents StartLoginInteractive from
+	// being called from the watcher goroutine while the Start call from
+	// the other goroutine is in progress.
+	// See https://github.com/tailscale/tailscale/issues/7036#issuecomment-2053771466
+	// TODO(bradfitz): simplify this once #11649 is cleaned up and Start is
+	// hopefully removed.
+	var localAPIMu sync.Mutex
+
+	startLoginInteractive := sync.OnceFunc(func() {
+		localAPIMu.Lock()
+		defer localAPIMu.Unlock()
+		localClient.StartLoginInteractive(ctx)
+	})
 
 	go func() {
+		var printed bool // whether we've yet printed anything to stdout or stderr
 		for {
 			n, err := watcher.Next()
 			if err != nil {
@@ -574,12 +586,14 @@ func runUp(ctx context.Context, cmd string, args []string, upArgs upArgsT) (retE
 	// Special case: bare "tailscale up" means to just start
 	// running, if there's ever been a login.
 	if simpleUp {
+		localAPIMu.Lock()
 		_, err := localClient.EditPrefs(ctx, &ipn.MaskedPrefs{
 			Prefs: ipn.Prefs{
 				WantRunning: true,
 			},
 			WantRunningSet: true,
 		})
+		localAPIMu.Unlock()
 		if err != nil {
 			return err
 		}
@@ -596,10 +610,13 @@ func runUp(ctx context.Context, cmd string, args []string, upArgs upArgsT) (retE
 		if err != nil {
 			return err
 		}
-		if err := localClient.Start(ctx, ipn.Options{
+		localAPIMu.Lock()
+		err = localClient.Start(ctx, ipn.Options{
 			AuthKey:     authKey,
 			UpdatePrefs: prefs,
-		}); err != nil {
+		})
+		localAPIMu.Unlock()
+		if err != nil {
 			return err
 		}
 		if upArgs.forceReauth {

cmd/tailscale/cli/update.go

@@ -19,7 +19,7 @@ import (
 
 var updateCmd = &ffcli.Command{
 	Name:       "update",
-	ShortUsage: "update",
+	ShortUsage: "tailscale update",
 	ShortHelp:  "Update Tailscale to the latest/different version",
 	Exec:       runUpdate,
 	FlagSet: (func() *flag.FlagSet {

cmd/tailscale/cli/version.go

@@ -8,7 +8,6 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"os"
 
 	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/clientupdate"
@@ -18,7 +17,7 @@ import (
 
 var versionCmd = &ffcli.Command{
 	Name:       "version",
-	ShortUsage: "version [flags]",
+	ShortUsage: "tailscale version [flags]",
 	ShortHelp:  "Print Tailscale version",
 	FlagSet: (func() *flag.FlagSet {
 		fs := newFlagSet("version")
@@ -70,7 +69,7 @@ func runVersion(ctx context.Context, args []string) error {
 			Meta:     m,
 			Upstream: upstreamVer,
 		}
-		e := json.NewEncoder(os.Stdout)
+		e := json.NewEncoder(Stdout)
 		e.SetIndent("", "\t")
 		return e.Encode(out)
 	}

cmd/tailscale/cli/web.go

@@ -26,7 +26,7 @@ import (
 
 var webCmd = &ffcli.Command{
 	Name:       "web",
-	ShortUsage: "web [flags]",
+	ShortUsage: "tailscale web [flags]",
 	ShortHelp:  "Run a web server for controlling Tailscale",
 
 	LongHelp: strings.TrimSpace(`

cmd/tailscale/cli/whois.go

@@ -9,7 +9,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"os"
 	"strings"
 	"text/tabwriter"
 
@@ -18,13 +17,12 @@ import (
 
 var whoisCmd = &ffcli.Command{
 	Name:       "whois",
-	ShortUsage: "whois [--json] ip[:port]",
+	ShortUsage: "tailscale whois [--json] ip[:port]",
 	ShortHelp:  "Show the machine and user associated with a Tailscale IP (v4 or v6)",
 	LongHelp: strings.TrimSpace(`
 	'tailscale whois' shows the machine and user associated with a Tailscale IP (v4 or v6).
 	`),
-	UsageFunc: usageFunc,
-	Exec:      runWhoIs,
+	Exec: runWhoIs,
 	FlagSet: func() *flag.FlagSet {
 		fs := newFlagSet("whois")
 		fs.BoolVar(&whoIsArgs.json, "json", false, "output in JSON format")
@@ -53,7 +51,7 @@ func runWhoIs(ctx context.Context, args []string) error {
 		return nil
 	}
 
-	w := tabwriter.NewWriter(os.Stdout, 10, 5, 5, ' ', 0)
+	w := tabwriter.NewWriter(Stdout, 10, 5, 5, ' ', 0)
 	fmt.Fprintf(w, "Machine:\n")
 	fmt.Fprintf(w, "  Name:\t%s\n", strings.TrimSuffix(who.Node.Name, "."))
 	fmt.Fprintf(w, "  ID:\t%s\n", who.Node.StableID)

cmd/tailscale/depaware.txt

@@ -27,7 +27,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
    L    github.com/jsimonetti/rtnetlink/internal/unix                from github.com/jsimonetti/rtnetlink
         github.com/kballard/go-shellquote                            from tailscale.com/cmd/tailscale/cli
      💣 github.com/mattn/go-colorable                                from tailscale.com/cmd/tailscale/cli
-     💣 github.com/mattn/go-isatty                                   from github.com/mattn/go-colorable+
+     💣 github.com/mattn/go-isatty                                   from tailscale.com/cmd/tailscale/cli+
    L 💣 github.com/mdlayher/netlink                                  from github.com/google/nftables+
    L 💣 github.com/mdlayher/netlink/nlenc                            from github.com/jsimonetti/rtnetlink+
    L    github.com/mdlayher/netlink/nltest                           from github.com/google/nftables
@@ -84,6 +84,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/derp                                           from tailscale.com/derp/derphttp
         tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck
         tailscale.com/disco                                          from tailscale.com/derp
+        tailscale.com/drive                                          from tailscale.com/client/tailscale+
         tailscale.com/envknob                                        from tailscale.com/client/tailscale+
         tailscale.com/health                                         from tailscale.com/net/tlsdial
         tailscale.com/health/healthmsg                               from tailscale.com/cmd/tailscale/cli
@@ -118,7 +119,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
      💣 tailscale.com/safesocket                                     from tailscale.com/client/tailscale+
         tailscale.com/syncs                                          from tailscale.com/cmd/tailscale/cli+
         tailscale.com/tailcfg                                        from tailscale.com/client/tailscale+
-        tailscale.com/tailfs                                         from tailscale.com/cmd/tailscale/cli+
         tailscale.com/tka                                            from tailscale.com/client/tailscale+
    W    tailscale.com/tsconst                                        from tailscale.com/net/interfaces
         tailscale.com/tstime                                         from tailscale.com/control/controlhttp+

cmd/tailscaled/depaware.txt

@@ -88,9 +88,14 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    W    github.com/dblohm7/wingoes/internal                          from github.com/dblohm7/wingoes/com
    W 💣 github.com/dblohm7/wingoes/pe                                from tailscale.com/util/osdiag+
   LW 💣 github.com/digitalocean/go-smbios/smbios                     from tailscale.com/posture
-     💣 github.com/djherbis/times                                    from tailscale.com/tailfs/tailfsimpl
+     💣 github.com/djherbis/times                                    from tailscale.com/drive/driveimpl
         github.com/fxamacker/cbor/v2                                 from tailscale.com/tka
         github.com/gaissmai/bart                                     from tailscale.com/net/tstun
+        github.com/go-json-experiment/json/internal                  from github.com/go-json-experiment/json/internal/jsonflags+
+        github.com/go-json-experiment/json/internal/jsonflags        from github.com/go-json-experiment/json/internal/jsonopts+
+        github.com/go-json-experiment/json/internal/jsonopts         from github.com/go-json-experiment/json/jsontext
+        github.com/go-json-experiment/json/internal/jsonwire         from github.com/go-json-experiment/json/jsontext
+        github.com/go-json-experiment/json/jsontext                  from tailscale.com/logtail
    W 💣 github.com/go-ole/go-ole                                     from github.com/go-ole/go-ole/oleutil+
    W 💣 github.com/go-ole/go-ole/oleutil                             from tailscale.com/wgengine/winnet
    L 💣 github.com/godbus/dbus/v5                                    from github.com/coreos/go-systemd/v22/dbus+
@@ -102,7 +107,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    L    github.com/google/nftables/expr                              from github.com/google/nftables+
    L    github.com/google/nftables/internal/parseexprfunc            from github.com/google/nftables+
    L    github.com/google/nftables/xt                                from github.com/google/nftables/expr+
-        github.com/google/uuid                                       from tailscale.com/clientupdate
+        github.com/google/uuid                                       from tailscale.com/clientupdate+
         github.com/gorilla/csrf                                      from tailscale.com/client/web
         github.com/gorilla/securecookie                              from github.com/gorilla/csrf
         github.com/hdevalence/ed25519consensus                       from tailscale.com/clientupdate/distsign+
@@ -111,7 +116,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    L    github.com/insomniacslk/dhcp/iana                            from github.com/insomniacslk/dhcp/dhcpv4
    L    github.com/insomniacslk/dhcp/interfaces                      from github.com/insomniacslk/dhcp/dhcpv4
    L    github.com/insomniacslk/dhcp/rfc1035label                    from github.com/insomniacslk/dhcp/dhcpv4
-        github.com/jellydator/ttlcache/v3                            from tailscale.com/tailfs/tailfsimpl/compositedav
+        github.com/jellydator/ttlcache/v3                            from tailscale.com/drive/driveimpl/compositedav
    L    github.com/jmespath/go-jmespath                              from github.com/aws/aws-sdk-go-v2/service/ssm
    L    github.com/josharian/native                                  from github.com/mdlayher/netlink+
    L 💣 github.com/jsimonetti/rtnetlink                              from tailscale.com/net/interfaces+
@@ -172,7 +177,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         github.com/tailscale/wireguard-go/rwcancel                   from github.com/tailscale/wireguard-go/device+
         github.com/tailscale/wireguard-go/tai64n                     from github.com/tailscale/wireguard-go/device
      💣 github.com/tailscale/wireguard-go/tun                        from github.com/tailscale/wireguard-go/device+
-        github.com/tailscale/xnet/webdav                             from tailscale.com/tailfs/tailfsimpl+
+        github.com/tailscale/xnet/webdav                             from tailscale.com/drive/driveimpl+
         github.com/tailscale/xnet/webdav/internal/xml                from github.com/tailscale/xnet/webdav
         github.com/tcnksm/go-httpstat                                from tailscale.com/net/netcheck
   LD    github.com/u-root/u-root/pkg/termios                         from tailscale.com/ssh/tailssh
@@ -251,6 +256,11 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/doctor/ethtool                                 from tailscale.com/ipn/ipnlocal
      💣 tailscale.com/doctor/permissions                             from tailscale.com/ipn/ipnlocal
         tailscale.com/doctor/routetable                              from tailscale.com/ipn/ipnlocal
+        tailscale.com/drive                                          from tailscale.com/client/tailscale+
+        tailscale.com/drive/driveimpl                                from tailscale.com/cmd/tailscaled
+        tailscale.com/drive/driveimpl/compositedav                   from tailscale.com/drive/driveimpl
+        tailscale.com/drive/driveimpl/dirfs                          from tailscale.com/drive/driveimpl+
+        tailscale.com/drive/driveimpl/shared                         from tailscale.com/drive/driveimpl+
         tailscale.com/envknob                                        from tailscale.com/client/tailscale+
         tailscale.com/health                                         from tailscale.com/control/controlclient+
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal
@@ -287,7 +297,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/net/flowtrack                                  from tailscale.com/net/packet+
      💣 tailscale.com/net/interfaces                                 from tailscale.com/cmd/tailscaled+
         tailscale.com/net/netaddr                                    from tailscale.com/ipn+
-        tailscale.com/net/netcheck                                   from tailscale.com/wgengine/magicsock
+        tailscale.com/net/netcheck                                   from tailscale.com/wgengine/magicsock+
         tailscale.com/net/neterror                                   from tailscale.com/net/dns/resolver+
         tailscale.com/net/netkernelconf                              from tailscale.com/ipn/ipnlocal
         tailscale.com/net/netknob                                    from tailscale.com/logpolicy+
@@ -320,11 +330,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/syncs                                          from tailscale.com/cmd/tailscaled+
         tailscale.com/tailcfg                                        from tailscale.com/client/tailscale+
         tailscale.com/taildrop                                       from tailscale.com/ipn/ipnlocal+
-        tailscale.com/tailfs                                         from tailscale.com/client/tailscale+
-        tailscale.com/tailfs/tailfsimpl                              from tailscale.com/cmd/tailscaled
-        tailscale.com/tailfs/tailfsimpl/compositedav                 from tailscale.com/tailfs/tailfsimpl
-        tailscale.com/tailfs/tailfsimpl/dirfs                        from tailscale.com/tailfs/tailfsimpl+
-        tailscale.com/tailfs/tailfsimpl/shared                       from tailscale.com/tailfs/tailfsimpl+
   LD    tailscale.com/tempfork/gliderlabs/ssh                        from tailscale.com/ssh/tailssh
         tailscale.com/tempfork/heap                                  from tailscale.com/wgengine/magicsock
         tailscale.com/tka                                            from tailscale.com/client/tailscale+
@@ -376,6 +381,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    W 💣 tailscale.com/util/osdiag/internal/wsc                       from tailscale.com/util/osdiag
         tailscale.com/util/osshare                                   from tailscale.com/cmd/tailscaled+
         tailscale.com/util/osuser                                    from tailscale.com/ipn/localapi+
+        tailscale.com/util/progresstracking                          from tailscale.com/ipn/localapi
         tailscale.com/util/race                                      from tailscale.com/net/dns/resolver
         tailscale.com/util/racebuild                                 from tailscale.com/logpolicy
         tailscale.com/util/rands                                     from tailscale.com/ipn/ipnlocal+
@@ -387,6 +393,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/util/sysresources                              from tailscale.com/wgengine/magicsock
         tailscale.com/util/systemd                                   from tailscale.com/control/controlclient+
         tailscale.com/util/testenv                                   from tailscale.com/ipn/ipnlocal+
+        tailscale.com/util/truncate                                  from tailscale.com/logtail
         tailscale.com/util/uniq                                      from tailscale.com/ipn/ipnlocal+
         tailscale.com/util/vizerror                                  from tailscale.com/tailcfg+
      💣 tailscale.com/util/winutil                                   from tailscale.com/clientupdate+
@@ -522,7 +529,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         math/rand                                                    from github.com/mdlayher/netlink+
         math/rand/v2                                                 from tailscale.com/util/rands
         mime                                                         from github.com/tailscale/xnet/webdav+
-        mime/multipart                                               from net/http
+        mime/multipart                                               from net/http+
         mime/quotedprintable                                         from mime/multipart
         net                                                          from crypto/tls+
         net/http                                                     from expvar+

cmd/tailscaled/tailscaled.go

@@ -33,6 +33,7 @@ import (
 	"tailscale.com/client/tailscale"
 	"tailscale.com/cmd/tailscaled/childproc"
 	"tailscale.com/control/controlclient"
+	"tailscale.com/drive/driveimpl"
 	"tailscale.com/envknob"
 	"tailscale.com/ipn/conffile"
 	"tailscale.com/ipn/ipnlocal"
@@ -52,7 +53,6 @@ import (
 	"tailscale.com/paths"
 	"tailscale.com/safesocket"
 	"tailscale.com/syncs"
-	"tailscale.com/tailfs/tailfsimpl"
 	"tailscale.com/tsd"
 	"tailscale.com/tsweb/varz"
 	"tailscale.com/types/flagtype"
@@ -79,7 +79,7 @@ func defaultTunName() string {
 		// "utun" is recognized by wireguard-go/tun/tun_darwin.go
 		// as a magic value that uses/creates any free number.
 		return "utun"
-	case "plan9":
+	case "plan9", "aix":
 		return "userspace-networking"
 	case "linux":
 		switch distro.Get() {
@@ -116,7 +116,7 @@ var args struct {
 	// or comma-separated list thereof.
 	tunname string
 
-	cleanup        bool
+	cleanUp        bool
 	confFile       string
 	debug          string
 	port           uint16
@@ -145,7 +145,7 @@ var subCommands = map[string]*func([]string) error{
 	"uninstall-system-daemon": &uninstallSystemDaemon,
 	"debug":                   &debugModeFunc,
 	"be-child":                &beChildFunc,
-	"serve-tailfs":            &serveTailFSFunc,
+	"serve-taildrive":         &serveDriveFunc,
 }
 
 var beCLI func() // non-nil if CLI is linked in
@@ -156,7 +156,7 @@ func main() {
 
 	printVersion := false
 	flag.IntVar(&args.verbose, "verbose", 0, "log verbosity level; 0 is default, 1 or higher are increasingly verbose")
-	flag.BoolVar(&args.cleanup, "cleanup", false, "clean up system state and exit")
+	flag.BoolVar(&args.cleanUp, "cleanup", false, "clean up system state and exit")
 	flag.StringVar(&args.debug, "debug", "", "listen address ([ip]:port) of optional debug server")
 	flag.StringVar(&args.socksAddr, "socks5-server", "", `optional [ip]:port to run a SOCK5 server (e.g. "localhost:1080")`)
 	flag.StringVar(&args.httpProxyAddr, "outbound-http-proxy-listen", "", `optional [ip]:port to run an outbound HTTP proxy (e.g. "localhost:8080")`)
@@ -207,7 +207,7 @@ func main() {
 		os.Exit(0)
 	}
 
-	if runtime.GOOS == "darwin" && os.Getuid() != 0 && !strings.Contains(args.tunname, "userspace-networking") && !args.cleanup {
+	if runtime.GOOS == "darwin" && os.Getuid() != 0 && !strings.Contains(args.tunname, "userspace-networking") && !args.cleanUp {
 		log.SetFlags(0)
 		log.Fatalf("tailscaled requires root; use sudo tailscaled (or use --tun=userspace-networking)")
 	}
@@ -387,12 +387,16 @@ func run() (err error) {
 	}
 	logf = logger.RateLimitedFn(logf, 5*time.Second, 5, 100)
 
-	if args.cleanup {
-		if envknob.Bool("TS_PLEASE_PANIC") {
-			panic("TS_PLEASE_PANIC asked us to panic")
-		}
-		dns.Cleanup(logf, args.tunname)
-		router.Cleanup(logf, args.tunname)
+	if envknob.Bool("TS_PLEASE_PANIC") {
+		panic("TS_PLEASE_PANIC asked us to panic")
+	}
+	// Always clean up, even if we're going to run the server. This covers cases
+	// such as when a system was rebooted without shutting down, or tailscaled
+	// crashed, and would for example restore system DNS configuration.
+	dns.CleanUp(logf, args.tunname)
+	router.CleanUp(logf, args.tunname)
+	// If the cleanUp flag was passed, then exit.
+	if args.cleanUp {
 		return nil
 	}
 
@@ -407,7 +411,7 @@ func run() (err error) {
 		debugMux = newDebugMux()
 	}
 
-	sys.Set(tailfsimpl.NewFileSystemForRemote(logf))
+	sys.Set(driveimpl.NewFileSystemForRemote(logf))
 
 	return startIPNServer(context.Background(), logf, pol.PublicID, sys)
 }
@@ -645,12 +649,12 @@ var tstunNew = tstun.New
 
 func tryEngine(logf logger.Logf, sys *tsd.System, name string) (onlyNetstack bool, err error) {
 	conf := wgengine.Config{
-		ListenPort:     args.port,
-		NetMon:         sys.NetMon.Get(),
-		Dialer:         sys.Dialer.Get(),
-		SetSubsystem:   sys.Set,
-		ControlKnobs:   sys.ControlKnobs(),
-		TailFSForLocal: tailfsimpl.NewFileSystemForLocal(logf),
+		ListenPort:    args.port,
+		NetMon:        sys.NetMon.Get(),
+		Dialer:        sys.Dialer.Get(),
+		SetSubsystem:  sys.Set,
+		ControlKnobs:  sys.ControlKnobs(),
+		DriveForLocal: driveimpl.NewFileSystemForLocal(logf),
 	}
 
 	onlyNetstack = name == "userspace-networking"
@@ -709,7 +713,6 @@ func tryEngine(logf logger.Logf, sys *tsd.System, name string) (onlyNetstack boo
 		conf.DNS = d
 		conf.Router = r
 		if handleSubnetsInNetstack() {
-			conf.Router = netstack.NewSubnetRouterWrapper(conf.Router)
 			netstackSubnetRouter = true
 		}
 		sys.Set(conf.Router)
@@ -753,7 +756,7 @@ func runDebugServer(mux *http.ServeMux, addr string) {
 }
 
 func newNetstack(logf logger.Logf, sys *tsd.System) (*netstack.Impl, error) {
-	tfs, _ := sys.TailFSForLocal.GetOK()
+	tfs, _ := sys.DriveForLocal.GetOK()
 	ret, err := netstack.Create(logf,
 		sys.Tun.Get(),
 		sys.Engine.Get(),
@@ -831,25 +834,25 @@ func beChild(args []string) error {
 	return f(args[1:])
 }
 
-var serveTailFSFunc = serveTailFS
+var serveDriveFunc = serveDrive
 
-// serveTailFS serves one or more tailfs on localhost using the WebDAV
-// protocol. On UNIX and MacOS tailscaled environment, tailfs spawns child
-// tailscaled processes in serve-tailfs mode in order to access the fliesystem
+// serveDrive serves one or more Taildrives on localhost using the WebDAV
+// protocol. On UNIX and MacOS tailscaled environment, Taildrive spawns child
+// tailscaled processes in serve-taildrive mode in order to access the fliesystem
 // as specific (usually unprivileged) users.
 //
-// serveTailFS prints the address on which it's listening to stdout so that the
+// serveDrive prints the address on which it's listening to stdout so that the
 // parent process knows where to connect to.
-func serveTailFS(args []string) error {
+func serveDrive(args []string) error {
 	if len(args) == 0 {
 		return errors.New("missing shares")
 	}
 	if len(args)%2 != 0 {
 		return errors.New("need <sharename> <path> pairs")
 	}
-	s, err := tailfsimpl.NewFileServer()
+	s, err := driveimpl.NewFileServer()
 	if err != nil {
-		return fmt.Errorf("unable to start tailfs FileServer: %v", err)
+		return fmt.Errorf("unable to start Taildrive file server: %v", err)
 	}
 	shares := make(map[string]string)
 	for i := 0; i < len(args); i += 2 {

cmd/tailscaled/tailscaled.service

@@ -6,7 +6,6 @@ After=network-pre.target NetworkManager.service systemd-resolved.service
 
 [Service]
 EnvironmentFile=/etc/default/tailscaled
-ExecStartPre=/usr/sbin/tailscaled --cleanup
 ExecStart=/usr/sbin/tailscaled --state=/var/lib/tailscale/tailscaled.state --socket=/run/tailscale/tailscaled.sock --port=${PORT} $FLAGS
 ExecStopPost=/usr/sbin/tailscaled --cleanup
 

cmd/tailscaled/tailscaled_windows.go

@@ -42,13 +42,13 @@ import (
 	"golang.org/x/sys/windows/svc/eventlog"
 	"golang.zx2c4.com/wintun"
 	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
+	"tailscale.com/drive/driveimpl"
 	"tailscale.com/envknob"
 	"tailscale.com/logpolicy"
 	"tailscale.com/logtail/backoff"
 	"tailscale.com/net/dns"
 	"tailscale.com/net/netmon"
 	"tailscale.com/net/tstun"
-	"tailscale.com/tailfs/tailfsimpl"
 	"tailscale.com/tsd"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/logid"
@@ -316,7 +316,7 @@ func beWindowsSubprocess() bool {
 	}
 	sys.Set(netMon)
 
-	sys.Set(tailfsimpl.NewFileSystemForRemote(log.Printf))
+	sys.Set(driveimpl.NewFileSystemForRemote(log.Printf))
 
 	publicLogID, _ := logid.ParsePublicID(logID)
 	err = startIPNServer(ctx, log.Printf, publicLogID, sys)

cmd/testcontrol/testcontrol.go

@@ -29,7 +29,7 @@ func main() {
 		DERPMap:         derpMap,
 		ExplicitBaseURL: "http://127.0.0.1:9911",
 	}
-	for i := 0; i < *flagNFake; i++ {
+	for range *flagNFake {
 		control.AddFakeNode()
 	}
 	mux := http.NewServeMux()

cmd/tsconnect/wasm/wasm_js.go

@@ -90,8 +90,11 @@ func newIPN(jsConfig js.Value) map[string]any {
 	c := logtail.Config{
 		Collection: lpc.Collection,
 		PrivateID:  lpc.PrivateID,
-		// NewZstdEncoder is intentionally not passed in, compressed requests
-		// set HTTP headers that are not supported by the no-cors fetching mode.
+
+		// Compressed requests set HTTP headers that are not supported by the
+		// no-cors fetching mode:
+		CompressLogs: false,
+
 		HTTPC: &http.Client{Transport: &noCORSTransport{http.DefaultTransport}},
 	}
 	logtail := logtail.NewLogger(c, log.Printf)
@@ -319,7 +322,7 @@ func (i *jsIPN) run(jsCallbacks js.Value) {
 }
 
 func (i *jsIPN) login() {
-	go i.lb.StartLoginInteractive()
+	go i.lb.StartLoginInteractive(context.Background())
 }
 
 func (i *jsIPN) logout() {

cmd/viewer/viewer.go

@@ -149,7 +149,7 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
 		}
 	}
 	writeTemplate("common")
-	for i := 0; i < t.NumFields(); i++ {
+	for i := range t.NumFields() {
 		f := t.Field(i)
 		fname := f.Name()
 		if !f.Exported() {
@@ -292,7 +292,7 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
 		}
 		writeTemplate("unsupportedField")
 	}
-	for i := 0; i < typ.NumMethods(); i++ {
+	for i := range typ.NumMethods() {
 		f := typ.Method(i)
 		if !f.Exported() {
 			continue

control/controlbase/conn_test.go

@@ -91,7 +91,7 @@ func TestFastPath(t *testing.T) {
 
 	const packets = 10
 	s := "test"
-	for i := 0; i < packets; i++ {
+	for range packets {
 		// Many separate writes, to force separate Noise frames that
 		// all get buffered up and then all sent as a single slice to
 		// the server.
@@ -251,7 +251,7 @@ func TestConnMemoryOverhead(t *testing.T) {
 	}
 	defer closeAll()
 
-	for i := 0; i < num; i++ {
+	for range num {
 		client, server := pair(t)
 		closers = append(closers, client, server)
 		go func() {

control/controlbase/handshake_test.go

@@ -64,7 +64,7 @@ func TestNoReuse(t *testing.T) {
 		serverHandshakes = map[[48]byte]bool{}
 		packets          = map[[32]byte]bool{}
 	)
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		var (
 			clientRaw, serverRaw = memnet.NewConn("noise", 128000)
 			clientBuf, serverBuf bytes.Buffer
@@ -162,7 +162,7 @@ func (r *tamperReader) Read(bs []byte) (int, error) {
 
 func TestTampering(t *testing.T) {
 	// Tamper with every byte of the client initiation message.
-	for i := 0; i < 101; i++ {
+	for i := range 101 {
 		var (
 			clientConn, serverRaw = memnet.NewConn("noise", 128000)
 			serverConn            = &readerConn{serverRaw, &tamperReader{serverRaw, i, 0}}
@@ -190,7 +190,7 @@ func TestTampering(t *testing.T) {
 	}
 
 	// Tamper with every byte of the server response message.
-	for i := 0; i < 51; i++ {
+	for i := range 51 {
 		var (
 			clientRaw, serverConn = memnet.NewConn("noise", 128000)
 			clientConn            = &readerConn{clientRaw, &tamperReader{clientRaw, i, 0}}
@@ -215,7 +215,7 @@ func TestTampering(t *testing.T) {
 	}
 
 	// Tamper with every byte of the first server>client transport message.
-	for i := 0; i < 30; i++ {
+	for i := range 30 {
 		var (
 			clientRaw, serverConn = memnet.NewConn("noise", 128000)
 			clientConn            = &readerConn{clientRaw, &tamperReader{clientRaw, 51 + i, 0}}
@@ -256,7 +256,7 @@ func TestTampering(t *testing.T) {
 	}
 
 	// Tamper with every byte of the first client>server transport message.
-	for i := 0; i < 30; i++ {
+	for i := range 30 {
 		var (
 			clientConn, serverRaw = memnet.NewConn("noise", 128000)
 			serverConn            = &readerConn{serverRaw, &tamperReader{serverRaw, 101 + i, 0}}

control/controlclient/controlclient_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func fieldsOf(t reflect.Type) (fields []string) {
-	for i := 0; i < t.NumField(); i++ {
+	for i := range t.NumField() {
 		if name := t.Field(i).Name; name != "_" {
 			fields = append(fields, name)
 		}

control/controlclient/direct.go

@@ -82,9 +82,9 @@ type Direct struct {
 
 	dialPlan ControlDialPlanner // can be nil
 
-	mu             sync.Mutex        // mutex guards the following fields
-	serverKey      key.MachinePublic // original ("legacy") nacl crypto_box-based public key
-	serverNoiseKey key.MachinePublic
+	mu              sync.Mutex        // mutex guards the following fields
+	serverLegacyKey key.MachinePublic // original ("legacy") nacl crypto_box-based public key; only used for signRegisterRequest on Windows now
+	serverNoiseKey  key.MachinePublic
 
 	sfGroup     singleflight.Group[struct{}, *NoiseClient] // protects noiseClient creation.
 	noiseClient *NoiseClient
@@ -436,12 +436,6 @@ type loginOpt struct {
 	OldNodeKeySignature tkatype.MarshaledSignature
 }
 
-// httpClient provides a common interface for the noiseClient and
-// the NaCl box http.Client.
-type httpClient interface {
-	Do(req *http.Request) (*http.Response, error)
-}
-
 // hostInfoLocked returns a Clone of c.hostinfo and c.netinfo.
 // It must only be called with c.mu held.
 func (c *Direct) hostInfoLocked() *tailcfg.Hostinfo {
@@ -454,7 +448,7 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 	c.mu.Lock()
 	persist := c.persist.AsStruct()
 	tryingNewKey := c.tryingNewKey
-	serverKey := c.serverKey
+	serverKey := c.serverLegacyKey
 	serverNoiseKey := c.serverNoiseKey
 	authKey, isWrapped, wrappedSig, wrappedKey := decodeWrappedAuthkey(c.authKey, c.logf)
 	hi := c.hostInfoLocked()
@@ -494,20 +488,22 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 		c.logf("control server key from %s: ts2021=%s, legacy=%v", c.serverURL, keys.PublicKey.ShortString(), keys.LegacyPublicKey.ShortString())
 
 		c.mu.Lock()
-		c.serverKey = keys.LegacyPublicKey
+		c.serverLegacyKey = keys.LegacyPublicKey
 		c.serverNoiseKey = keys.PublicKey
 		c.mu.Unlock()
 		serverKey = keys.LegacyPublicKey
 		serverNoiseKey = keys.PublicKey
 
-		// For servers supporting the Noise transport,
-		// proactively shut down our TLS TCP connection.
+		// Proactively shut down our TLS TCP connection.
 		// We're not going to need it and it's nicer to the
 		// server.
-		if !serverNoiseKey.IsZero() {
-			c.httpc.CloseIdleConnections()
-		}
+		c.httpc.CloseIdleConnections()
 	}
+
+	if serverNoiseKey.IsZero() {
+		return false, "", nil, errors.New("control server is too old; no noise key")
+	}
+
 	var oldNodeKey key.NodePublic
 	switch {
 	case opt.Logout:
@@ -594,7 +590,7 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 	request.Auth.Provider = persist.Provider
 	request.Auth.LoginName = persist.UserProfile.LoginName
 	request.Auth.AuthKey = authKey
-	err = signRegisterRequest(&request, c.serverURL, c.serverKey, machinePrivKey.Public())
+	err = signRegisterRequest(&request, c.serverURL, c.serverLegacyKey, machinePrivKey.Public())
 	if err != nil {
 		// If signing failed, clear all related fields
 		request.SignatureType = tailcfg.SignatureNone
@@ -614,21 +610,16 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 	}
 
 	// URL and httpc are protocol specific.
-	var url string
-	var httpc httpClient
-	if serverNoiseKey.IsZero() {
-		httpc = c.httpc
-		url = fmt.Sprintf("%s/machine/%s", c.serverURL, machinePrivKey.Public().UntypedHexString())
-	} else {
-		request.Version = tailcfg.CurrentCapabilityVersion
-		httpc, err = c.getNoiseClient()
-		if err != nil {
-			return regen, opt.URL, nil, fmt.Errorf("getNoiseClient: %w", err)
-		}
-		url = fmt.Sprintf("%s/machine/register", c.serverURL)
-		url = strings.Replace(url, "http:", "https:", 1)
+
+	request.Version = tailcfg.CurrentCapabilityVersion
+	httpc, err := c.getNoiseClient()
+	if err != nil {
+		return regen, opt.URL, nil, fmt.Errorf("getNoiseClient: %w", err)
 	}
-	bodyData, err := encode(request, serverKey, serverNoiseKey, machinePrivKey)
+	url := fmt.Sprintf("%s/machine/register", c.serverURL)
+	url = strings.Replace(url, "http:", "https:", 1)
+
+	bodyData, err := encode(request)
 	if err != nil {
 		return regen, opt.URL, nil, err
 	}
@@ -650,7 +641,7 @@ func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, new
 			res.StatusCode, strings.TrimSpace(string(msg)))
 	}
 	resp := tailcfg.RegisterResponse{}
-	if err := decode(res, &resp, serverKey, serverNoiseKey, machinePrivKey); err != nil {
+	if err := decode(res, &resp); err != nil {
 		c.logf("error decoding RegisterResponse with server key %s and machine key %s: %v", serverKey, machinePrivKey.Public(), err)
 		return regen, opt.URL, nil, fmt.Errorf("register request: %v", err)
 	}
@@ -844,7 +835,6 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 	c.mu.Lock()
 	persist := c.persist
 	serverURL := c.serverURL
-	serverKey := c.serverKey
 	serverNoiseKey := c.serverNoiseKey
 	hi := c.hostInfoLocked()
 	backendLogID := hi.BackendLogID
@@ -858,6 +848,10 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 	}
 	c.mu.Unlock()
 
+	if serverNoiseKey.IsZero() {
+		return errors.New("control server is too old; no noise key")
+	}
+
 	machinePrivKey, err := c.getMachinePrivKey()
 	if err != nil {
 		return fmt.Errorf("getMachinePrivKey: %w", err)
@@ -914,7 +908,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 	}
 	request.Compress = "zstd"
 
-	bodyData, err := encode(request, serverKey, serverNoiseKey, machinePrivKey)
+	bodyData, err := encode(request)
 	if err != nil {
 		vlogf("netmap: encode: %v", err)
 		return err
@@ -926,20 +920,36 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 	machinePubKey := machinePrivKey.Public()
 	t0 := c.clock.Now()
 
-	// Url and httpc are protocol specific.
-	var url string
-	var httpc httpClient
-	if serverNoiseKey.IsZero() {
-		httpc = c.httpc
-		url = fmt.Sprintf("%s/machine/%s/map", serverURL, machinePubKey.UntypedHexString())
-	} else {
-		httpc, err = c.getNoiseClient()
-		if err != nil {
-			return fmt.Errorf("getNoiseClient: %w", err)
-		}
-		url = fmt.Sprintf("%s/machine/map", serverURL)
-		url = strings.Replace(url, "http:", "https:", 1)
+	httpc, err := c.getNoiseClient()
+	if err != nil {
+		return fmt.Errorf("getNoiseClient: %w", err)
 	}
+	url := fmt.Sprintf("%s/machine/map", serverURL)
+	url = strings.Replace(url, "http:", "https:", 1)
+
+	// Create a watchdog timer that breaks the connection if we don't receive a
+	// MapResponse from the network at least once every two minutes. The
+	// watchdog timer is stopped every time we receive a MapResponse (so it
+	// doesn't run when we're processing a MapResponse message, including any
+	// long-running requested operations like Debug.Sleep) and is reset whenever
+	// we go back to blocking on network reads.
+	// The watchdog timer also covers the initial request (effectively the
+	// pre-body and initial-body read timeouts) as we do not have any other
+	// keep-alive mechanism for the initial request.
+	watchdogTimer, watchdogTimedOut := c.clock.NewTimer(watchdogTimeout)
+	defer watchdogTimer.Stop()
+
+	go func() {
+		select {
+		case <-ctx.Done():
+			vlogf("netmap: ending timeout goroutine")
+			return
+		case <-watchdogTimedOut:
+			c.logf("map response long-poll timed out!")
+			cancel()
+			return
+		}
+	}()
 
 	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(bodyData))
 	if err != nil {
@@ -962,6 +972,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 	defer res.Body.Close()
 
 	health.NoteMapRequestHeard(request)
+	watchdogTimer.Reset(watchdogTimeout)
 
 	if nu == nil {
 		io.Copy(io.Discard, res.Body)
@@ -993,27 +1004,6 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 		c.expiry = nm.Expiry
 	}
 
-	// Create a watchdog timer that breaks the connection if we don't receive a
-	// MapResponse from the network at least once every two minutes. The
-	// watchdog timer is stopped every time we receive a MapResponse (so it
-	// doesn't run when we're processing a MapResponse message, including any
-	// long-running requested operations like Debug.Sleep) and is reset whenever
-	// we go back to blocking on network reads.
-	watchdogTimer, watchdogTimedOut := c.clock.NewTimer(watchdogTimeout)
-	defer watchdogTimer.Stop()
-
-	go func() {
-		select {
-		case <-ctx.Done():
-			vlogf("netmap: ending timeout goroutine")
-			return
-		case <-watchdogTimedOut:
-			c.logf("map response long-poll timed out!")
-			cancel()
-			return
-		}
-	}()
-
 	// gotNonKeepAliveMessage is whether we've yet received a MapResponse message without
 	// KeepAlive set.
 	var gotNonKeepAliveMessage bool
@@ -1043,7 +1033,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 		vlogf("netmap: read body after %v", time.Since(t0).Round(time.Millisecond))
 
 		var resp tailcfg.MapResponse
-		if err := c.decodeMsg(msg, &resp, machinePrivKey); err != nil {
+		if err := c.decodeMsg(msg, &resp); err != nil {
 			vlogf("netmap: decode error: %v", err)
 			return err
 		}
@@ -1160,9 +1150,8 @@ func initDisplayNames(selfNode tailcfg.NodeView, resp *tailcfg.MapResponse) {
 	}
 }
 
-// decode JSON decodes the res.Body into v. If serverNoiseKey is not specified,
-// it uses the serverKey and mkey to decode the message from the NaCl-crypto-box.
-func decode(res *http.Response, v any, serverKey, serverNoiseKey key.MachinePublic, mkey key.MachinePrivate) error {
+// decode JSON decodes the res.Body into v.
+func decode(res *http.Response, v any) error {
 	defer res.Body.Close()
 	msg, err := io.ReadAll(io.LimitReader(res.Body, 1<<20))
 	if err != nil {
@@ -1171,10 +1160,7 @@ func decode(res *http.Response, v any, serverKey, serverNoiseKey key.MachinePubl
 	if res.StatusCode != 200 {
 		return fmt.Errorf("%d: %v", res.StatusCode, string(msg))
 	}
-	if !serverNoiseKey.IsZero() {
-		return json.Unmarshal(msg, v)
-	}
-	return decodeMsg(msg, v, serverKey, mkey)
+	return json.Unmarshal(msg, v)
 }
 
 var (
@@ -1185,25 +1171,8 @@ var (
 var jsonEscapedZero = []byte(`\u0000`)
 
 // decodeMsg is responsible for uncompressing msg and unmarshaling into v.
-// If c.serverNoiseKey is not specified, it uses the c.serverKey and mkey
-// to first the decrypt msg from the NaCl-crypto-box.
-func (c *Direct) decodeMsg(msg []byte, v any, mkey key.MachinePrivate) error {
-	c.mu.Lock()
-	serverKey := c.serverKey
-	serverNoiseKey := c.serverNoiseKey
-	c.mu.Unlock()
-
-	var decrypted []byte
-	if serverNoiseKey.IsZero() {
-		var ok bool
-		decrypted, ok = mkey.OpenFrom(serverKey, msg)
-		if !ok {
-			return errors.New("cannot decrypt response")
-		}
-	} else {
-		decrypted = msg
-	}
-	b, err := zstdframe.AppendDecode(nil, decrypted)
+func (c *Direct) decodeMsg(compressedMsg []byte, v any) error {
+	b, err := zstdframe.AppendDecode(nil, compressedMsg)
 	if err != nil {
 		return err
 	}
@@ -1220,26 +1189,11 @@ func (c *Direct) decodeMsg(msg []byte, v any, mkey key.MachinePrivate) error {
 		return fmt.Errorf("response: %v", err)
 	}
 	return nil
-
 }
 
-func decodeMsg(msg []byte, v any, serverKey key.MachinePublic, machinePrivKey key.MachinePrivate) error {
-	decrypted, ok := machinePrivKey.OpenFrom(serverKey, msg)
-	if !ok {
-		return errors.New("cannot decrypt response")
-	}
-	if bytes.Contains(decrypted, jsonEscapedZero) {
-		log.Printf("[unexpected] zero byte in controlclient decodeMsg into %T: %q", v, decrypted)
-	}
-	if err := json.Unmarshal(decrypted, v); err != nil {
-		return fmt.Errorf("response: %v", err)
-	}
-	return nil
-}
-
-// encode JSON encodes v. If serverNoiseKey is not specified, it uses the serverKey and mkey to
-// seal the message into a NaCl-crypto-box.
-func encode(v any, serverKey, serverNoiseKey key.MachinePublic, mkey key.MachinePrivate) ([]byte, error) {
+// encode JSON encodes v as JSON, logging tailcfg.MapRequest values if
+// debugMap is set.
+func encode(v any) ([]byte, error) {
 	b, err := json.Marshal(v)
 	if err != nil {
 		return nil, err
@@ -1249,10 +1203,7 @@ func encode(v any, serverKey, serverNoiseKey key.MachinePublic, mkey key.Machine
 			log.Printf("MapRequest: %s", b)
 		}
 	}
-	if !serverNoiseKey.IsZero() {
-		return b, nil
-	}
-	return mkey.SealTo(serverKey, b), nil
+	return b, nil
 }
 
 func loadServerPubKeys(ctx context.Context, httpc *http.Client, serverURL string) (*tailcfg.OverTLSPublicKeyResponse, error) {
@@ -1349,7 +1300,7 @@ func (c *Direct) isUniquePingRequest(pr *tailcfg.PingRequest) bool {
 
 func (c *Direct) answerPing(pr *tailcfg.PingRequest) {
 	httpc := c.httpc
-	useNoise := pr.URLIsNoise || pr.Types == "c2n" && c.noiseConfigured()
+	useNoise := pr.URLIsNoise || pr.Types == "c2n"
 	if useNoise {
 		nc, err := c.getNoiseClient()
 		if err != nil {
@@ -1550,14 +1501,6 @@ func (c *Direct) setDNSNoise(ctx context.Context, req *tailcfg.SetDNSRequest) er
 	return nil
 }
 
-// noiseConfigured reports whether the client can communicate with Control
-// over Noise.
-func (c *Direct) noiseConfigured() bool {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return !c.serverNoiseKey.IsZero()
-}
-
 // SetDNS sends the SetDNSRequest request to the control plane server,
 // requesting a DNS record be created or updated.
 func (c *Direct) SetDNS(ctx context.Context, req *tailcfg.SetDNSRequest) (err error) {
@@ -1567,53 +1510,7 @@ func (c *Direct) SetDNS(ctx context.Context, req *tailcfg.SetDNSRequest) (err er
 			metricSetDNSError.Add(1)
 		}
 	}()
-	if c.noiseConfigured() {
-		return c.setDNSNoise(ctx, req)
-	}
-	c.mu.Lock()
-	serverKey := c.serverKey
-	c.mu.Unlock()
-
-	if serverKey.IsZero() {
-		return errors.New("zero serverKey")
-	}
-	machinePrivKey, err := c.getMachinePrivKey()
-	if err != nil {
-		return fmt.Errorf("getMachinePrivKey: %w", err)
-	}
-	if machinePrivKey.IsZero() {
-		return errors.New("getMachinePrivKey returned zero key")
-	}
-
-	// TODO(maisem): dedupe this codepath from SetDNSNoise.
-	var serverNoiseKey key.MachinePublic
-	bodyData, err := encode(req, serverKey, serverNoiseKey, machinePrivKey)
-	if err != nil {
-		return err
-	}
-	body := bytes.NewReader(bodyData)
-
-	u := fmt.Sprintf("%s/machine/%s/set-dns", c.serverURL, machinePrivKey.Public().UntypedHexString())
-	hreq, err := http.NewRequestWithContext(ctx, "POST", u, body)
-	if err != nil {
-		return err
-	}
-	res, err := c.httpc.Do(hreq)
-	if err != nil {
-		return err
-	}
-	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		msg, _ := io.ReadAll(res.Body)
-		return fmt.Errorf("set-dns response: %v, %.200s", res.Status, strings.TrimSpace(string(msg)))
-	}
-	var setDNSRes tailcfg.SetDNSResponse
-	if err := decode(res, &setDNSRes, serverKey, serverNoiseKey, machinePrivKey); err != nil {
-		c.logf("error decoding SetDNSResponse with server key %s and machine key %s: %v", serverKey, machinePrivKey.Public(), err)
-		return fmt.Errorf("set-dns-response: %w", err)
-	}
-
-	return nil
+	return c.setDNSNoise(ctx, req)
 }
 
 func (c *Direct) DoNoiseRequest(req *http.Request) (*http.Response, error) {

control/controlclient/map.go

@@ -563,7 +563,7 @@ var nodeFields = sync.OnceValue(getNodeFields)
 func getNodeFields() []string {
 	rt := reflect.TypeFor[tailcfg.Node]()
 	ret := make([]string, rt.NumField())
-	for i := 0; i < rt.NumField(); i++ {
+	for i := range rt.NumField() {
 		ret[i] = rt.Field(i).Name
 	}
 	return ret

control/controlclient/map_test.go

@@ -1019,7 +1019,7 @@ func BenchmarkMapSessionDelta(b *testing.B) {
 					Name: "foo.bar.ts.net.",
 				},
 			}
-			for i := 0; i < size; i++ {
+			for i := range size {
 				res.Peers = append(res.Peers, &tailcfg.Node{
 					ID:         tailcfg.NodeID(i + 2),
 					Name:       fmt.Sprintf("peer%d.bar.ts.net.", i),
@@ -1046,7 +1046,7 @@ func BenchmarkMapSessionDelta(b *testing.B) {
 
 			// Now for the core of the benchmark loop, just toggle
 			// a single node's online status.
-			for i := 0; i < b.N; i++ {
+			for i := range b.N {
 				if err := ms.HandleNonKeepAliveMapResponse(ctx, &tailcfg.MapResponse{
 					OnlineChange: map[tailcfg.NodeID]bool{
 						2: i%2 == 0,

control/controlhttp/http_test.go

@@ -729,7 +729,7 @@ func (d *closeTrackDialer) Done() {
 	// Sleep/wait a few times on the assumption that things will close
 	// "eventually".
 	const iters = 100
-	for i := 0; i < iters; i++ {
+	for i := range iters {
 		d.mu.Lock()
 		if len(d.conns) == 0 {
 			d.mu.Unlock()

derp/derp_test.go

@@ -56,7 +56,7 @@ func TestSendRecv(t *testing.T) {
 	const numClients = 3
 	var clientPrivateKeys []key.NodePrivate
 	var clientKeys []key.NodePublic
-	for i := 0; i < numClients; i++ {
+	for range numClients {
 		priv := key.NewNode()
 		clientPrivateKeys = append(clientPrivateKeys, priv)
 		clientKeys = append(clientKeys, priv.Public())
@@ -73,7 +73,7 @@ func TestSendRecv(t *testing.T) {
 	var recvChs []chan []byte
 	errCh := make(chan error, 3)
 
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		t.Logf("Connecting client %d ...", i)
 		cout, err := net.Dial("tcp", ln.Addr().String())
 		if err != nil {
@@ -111,7 +111,7 @@ func TestSendRecv(t *testing.T) {
 	var peerGoneCountNotHere expvar.Int
 
 	t.Logf("Starting read loops")
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		go func(i int) {
 			for {
 				m, err := clients[i].Recv()
@@ -233,7 +233,7 @@ func TestSendRecv(t *testing.T) {
 	wantUnknownPeers(1)
 
 	// PeerGoneNotHere is rate-limited to 3 times a second
-	for i := 0; i < 5; i++ {
+	for range 5 {
 		if err := clients[1].Send(neKey, callMe); err != nil {
 			t.Fatal(err)
 		}
@@ -389,7 +389,7 @@ func TestSendFreeze(t *testing.T) {
 		// if any tokens remain in the channel, they
 		// must have been generated after drainAny was
 		// called.
-		for i := 0; i < cap(ch); i++ {
+		for range cap(ch) {
 			select {
 			case <-ch:
 			default:
@@ -456,7 +456,7 @@ func TestSendFreeze(t *testing.T) {
 	aliceConn.Close()
 	cathyConn.Close()
 
-	for i := 0; i < cap(errCh); i++ {
+	for range cap(errCh) {
 		err := <-errCh
 		if err != nil {
 			if errors.Is(err, io.EOF) || errors.Is(err, net.ErrClosed) {
@@ -891,7 +891,7 @@ func TestMultiForwarder(t *testing.T) {
 	// run long enough concurrently with {Add,Remove}PacketForwarder loop above.
 	numMsgs := 5000
 	var fwd PacketForwarder
-	for i := 0; i < numMsgs; i++ {
+	for i := range numMsgs {
 		s.mu.Lock()
 		fwd = s.clientsMesh[u]
 		s.mu.Unlock()
@@ -1288,7 +1288,7 @@ func TestServerDupClients(t *testing.T) {
 
 func TestLimiter(t *testing.T) {
 	rl := rate.NewLimiter(rate.Every(time.Minute), 100)
-	for i := 0; i < 200; i++ {
+	for i := range 200 {
 		r := rl.Reserve()
 		d := r.Delay()
 		t.Logf("i=%d, allow=%v, d=%v", i, r.OK(), d)
@@ -1352,7 +1352,7 @@ func benchmarkSendRecvSize(b *testing.B, packetSize int) {
 	b.SetBytes(int64(len(msg)))
 	b.ReportAllocs()
 	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for range b.N {
 		if err := client.Send(clientKey, msg); err != nil {
 			b.Fatal(err)
 		}
@@ -1363,7 +1363,7 @@ func BenchmarkWriteUint32(b *testing.B) {
 	w := bufio.NewWriter(io.Discard)
 	b.ReportAllocs()
 	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for range b.N {
 		writeUint32(w, 0x0ba3a)
 	}
 }
@@ -1381,7 +1381,7 @@ func BenchmarkReadUint32(b *testing.B) {
 	var err error
 	b.ReportAllocs()
 	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for range b.N {
 		sinkU32, err = readUint32(r)
 		if err != nil {
 			b.Fatal(err)
@@ -1454,7 +1454,7 @@ func TestClientSendRateLimiting(t *testing.T) {
 
 	// Flood should all succeed.
 	cw.ResetStats()
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		if err := c.send(key.NodePublic{}, pkt); err != nil {
 			t.Fatal(err)
 		}
@@ -1473,7 +1473,7 @@ func TestClientSendRateLimiting(t *testing.T) {
 		TokenBucketBytesPerSecond: 1,
 		TokenBucketBytesBurst:     int(bytes1 * 2),
 	})
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		if err := c.send(key.NodePublic{}, pkt); err != nil {
 			t.Fatal(err)
 		}

derp/derphttp/derphttp_client.go

@@ -86,7 +86,8 @@ type Client struct {
 	addrFamSelAtomic syncs.AtomicValue[AddressFamilySelector]
 
 	mu           sync.Mutex
-	started      bool // true upon first connect, never transitions to false
+	atomicState  syncs.AtomicValue[ConnectedState] // hold mu to write
+	started      bool                              // true upon first connect, never transitions to false
 	preferred    bool
 	canAckPings  bool
 	closed       bool
@@ -99,6 +100,14 @@ type Client struct {
 	clock        tstime.Clock
 }
 
+// ConnectedState describes the state of a derphttp Client.
+type ConnectedState struct {
+	Connected  bool
+	Connecting bool
+	Closed     bool
+	LocalAddr  netip.AddrPort // if Connected
+}
+
 func (c *Client) String() string {
 	return fmt.Sprintf("<derphttp_client.Client %s url=%s>", c.ServerPublicKey().ShortString(), c.url)
 }
@@ -307,6 +316,12 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien
 	if c.client != nil {
 		return c.client, c.connGen, nil
 	}
+	c.atomicState.Store(ConnectedState{Connecting: true})
+	defer func() {
+		if err != nil {
+			c.atomicState.Store(ConnectedState{Connecting: false})
+		}
+	}()
 
 	// timeout is the fallback maximum time (if ctx doesn't limit
 	// it further) to do all of: DNS + TCP + TLS + HTTP Upgrade +
@@ -524,6 +539,12 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien
 	c.netConn = tcpConn
 	c.tlsState = tlsState
 	c.connGen++
+
+	localAddr, _ := c.client.LocalAddr()
+	c.atomicState.Store(ConnectedState{
+		Connected: true,
+		LocalAddr: localAddr,
+	})
 	return c.client, c.connGen, nil
 }
 
@@ -795,7 +816,7 @@ func (c *Client) dialNodeUsingProxy(ctx context.Context, n *tailcfg.DERPNode, pr
 		authHeader = fmt.Sprintf("Proxy-Authorization: %s\r\n", v)
 	}
 
-	if _, err := fmt.Fprintf(proxyConn, "CONNECT %s HTTP/1.1\r\nHost: %s\r\n%s\r\n", target, pu.Hostname(), authHeader); err != nil {
+	if _, err := fmt.Fprintf(proxyConn, "CONNECT %s HTTP/1.1\r\nHost: %s\r\n%s\r\n", target, target, authHeader); err != nil {
 		if ctx.Err() != nil {
 			return nil, ctx.Err()
 		}
@@ -906,16 +927,15 @@ func (c *Client) SendPing(data [8]byte) error {
 // LocalAddr reports c's local TCP address, without any implicit
 // connect or reconnect.
 func (c *Client) LocalAddr() (netip.AddrPort, error) {
-	c.mu.Lock()
-	closed, client := c.closed, c.client
-	c.mu.Unlock()
-	if closed {
+	st := c.atomicState.Load()
+	if st.Closed {
 		return netip.AddrPort{}, ErrClientClosed
 	}
-	if client == nil {
+	la := st.LocalAddr
+	if !st.Connected && !la.IsValid() {
 		return netip.AddrPort{}, errors.New("client not connected")
 	}
-	return client.LocalAddr()
+	return la, nil
 }
 
 func (c *Client) ForwardPacket(from, to key.NodePublic, b []byte) error {
@@ -1049,6 +1069,7 @@ func (c *Client) Close() error {
 	if c.netConn != nil {
 		c.netConn.Close()
 	}
+	c.atomicState.Store(ConnectedState{Closed: true})
 	return nil
 }
 

derp/derphttp/derphttp_test.go

@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/tls"
+	"fmt"
 	"net"
 	"net/http"
 	"net/netip"
@@ -24,7 +25,7 @@ func TestSendRecv(t *testing.T) {
 	const numClients = 3
 	var clientPrivateKeys []key.NodePrivate
 	var clientKeys []key.NodePublic
-	for i := 0; i < numClients; i++ {
+	for range numClients {
 		priv := key.NewNode()
 		clientPrivateKeys = append(clientPrivateKeys, priv)
 		clientKeys = append(clientKeys, priv.Public())
@@ -65,7 +66,7 @@ func TestSendRecv(t *testing.T) {
 		}
 		wg.Wait()
 	}()
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		key := clientPrivateKeys[i]
 		c, err := NewClient(key, serverURL, t.Logf)
 		if err != nil {
@@ -310,7 +311,7 @@ func TestBreakWatcherConnRecv(t *testing.T) {
 
 	// Wait for the watcher to run, then break the connection and check if it
 	// reconnected and received peer updates.
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		select {
 		case peers := <-watcherChan:
 			if peers != 1 {
@@ -383,7 +384,7 @@ func TestBreakWatcherConn(t *testing.T) {
 
 	// Wait for the watcher to run, then break the connection and check if it
 	// reconnected and received peer updates.
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		select {
 		case peers := <-watcherChan:
 			if peers != 1 {
@@ -447,3 +448,16 @@ func TestRunWatchConnectionLoopServeConnect(t *testing.T) {
 	}
 	watcher.RunWatchConnectionLoop(ctx, key.NodePublic{}, t.Logf, noopAdd, noopRemove)
 }
+
+// verify that the LocalAddr method doesn't acquire the mutex.
+// See https://github.com/tailscale/tailscale/issues/11519
+func TestLocalAddrNoMutex(t *testing.T) {
+	var c Client
+	c.mu.Lock()
+	defer c.mu.Unlock() // not needed in test but for symmetry
+
+	_, err := c.LocalAddr()
+	if got, want := fmt.Sprint(err), "client not connected"; got != want {
+		t.Errorf("got error %q; want %q", got, want)
+	}
+}

docs/windows/policy/en-US/tailscale.adml

@@ -13,6 +13,7 @@
             <string id="SINCE_V1_56">Tailscale version 1.56.0 and later</string>
             <string id="PARTIAL_FULL_SINCE_V1_56">Tailscale version 1.56.0 and later (full support), some earlier versions (partial support)</string>
             <string id="SINCE_V1_58">Tailscale version 1.58.0 and later</string>
+            <string id="SINCE_V1_62">Tailscale version 1.62.0 and later</string>
             <string id="Tailscale_Category">Tailscale</string>
             <string id="UI_Category">UI customization</string>
             <string id="Settings_Category">Settings</string>
@@ -195,6 +196,14 @@ If you enable this policy, then data collection is always enabled.
 If you disable this policy, then data collection is always disabled.
 
 If you do not configure this policy, then data collection depends on if it has been enabled from the CLI (as of Tailscale 1.56), it may be present in the GUI in later versions.]]></string>
+            <string id="ManagedBy">Show the "Managed By {Organization}" menu item</string>
+            <string id="ManagedBy_Help"><![CDATA[Use this policy to configure the “Managed By {Organization}” item in the Tailscale Menu.
+
+If you enable this policy, the menu item will be displayed indicating the organization name. For instance, “Managed By XYZ Corp, Inc.”. Optionally, you can provide a custom message to be displayed when a user clicks on the “Managed By” menu item, and a URL pointing to a help desk webpage or other helpful resources for users in the organization.
+
+If you disable this policy or do not configure it, the corresponding menu item will be hidden.
+
+See https://tailscale.com/kb/1315/mdm-keys#set-your-organization-name for more details.]]></string>
         </stringTable>
         <presentationTable>
             <presentation id="LoginURL">
@@ -217,6 +226,17 @@ If you do not configure this policy, then data collection depends on if it has b
                     <label>Exit Node</label>
                 </textBox>
             </presentation>
+            <presentation id="ManagedBy">
+                <textBox refId="ManagedByOrganization">
+                    <label>Organization Name:</label>
+                </textBox>
+                <textBox refId="ManagedByCustomMessage">
+                    <label>Custom Message:</label>
+                </textBox>
+                <textBox refId="ManagedBySupportURL">
+                    <label>Support URL:</label>
+                </textBox>
+            </presentation>
         </presentationTable>
     </resources>
 </policyDefinitionResources>

docs/windows/policy/tailscale.admx

@@ -42,6 +42,10 @@
                   displayName="$(string.SINCE_V1_58)">
         <and><reference ref="TAILSCALE_PRODUCT"/></and>
       </definition>
+      <definition name="SINCE_V1_62"
+                  displayName="$(string.SINCE_V1_62)">
+        <and><reference ref="TAILSCALE_PRODUCT"/></and>
+      </definition>
     </definitions>
   </supportedOn>
   <categories>
@@ -252,5 +256,14 @@
         <string>hide</string>
       </disabledValue>
     </policy>
+    <policy name="ManagedBy" class="Machine" displayName="$(string.ManagedBy)" explainText="$(string.ManagedBy_Help)" presentation="$(presentation.ManagedBy)" key="Software\Policies\Tailscale">
+      <parentCategory ref="UI_Category" />
+      <supportedOn ref="SINCE_V1_62" />
+      <elements>
+        <text id="ManagedByOrganization" valueName="ManagedByOrganizationName" required="true" />
+        <text id="ManagedByCustomMessage" valueName="ManagedByCaption" />
+        <text id="ManagedBySupportURL" valueName="ManagedByURL" />
+      </elements>
+    </policy>
   </policies>
 </policyDefinitions>

drive/drive_clone.go

@@ -3,7 +3,7 @@
 
 // Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
 
-package tailfs
+package drive
 
 // Clone makes a deep copy of Share.
 // The result aliases no memory with the original.

drive/drive_view.go

@@ -3,7 +3,7 @@
 
 // Code generated by tailscale/cmd/viewer; DO NOT EDIT.
 
-package tailfs
+package drive
 
 import (
 	"encoding/json"

drive/driveimpl/birthtiming.go

@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package tailfsimpl
+package driveimpl
 
 import (
 	"context"

drive/driveimpl/birthtiming_test.go

@@ -5,7 +5,7 @@
 
 //go:build windows || darwin
 
-package tailfsimpl
+package driveimpl
 
 import (
 	"context"

drive/driveimpl/compositedav/compositedav.go

@@ -17,8 +17,8 @@ import (
 	"sync"
 
 	"github.com/tailscale/xnet/webdav"
-	"tailscale.com/tailfs/tailfsimpl/dirfs"
-	"tailscale.com/tailfs/tailfsimpl/shared"
+	"tailscale.com/drive/driveimpl/dirfs"
+	"tailscale.com/drive/driveimpl/shared"
 	"tailscale.com/tstime"
 	"tailscale.com/types/logger"
 )

drive/driveimpl/compositedav/propfind.go

@@ -10,7 +10,7 @@ import (
 	"net/http"
 	"regexp"
 
-	"tailscale.com/tailfs/tailfsimpl/shared"
+	"tailscale.com/drive/driveimpl/shared"
 )
 
 var (

drive/driveimpl/connlistener.go

@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package tailfsimpl
+package driveimpl
 
 import (
 	"log"

drive/driveimpl/connlistener_test.go

@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package tailfsimpl
+package driveimpl
 
 import (
 	"log"

drive/driveimpl/dirfs/dirfs.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"tailscale.com/tailfs/tailfsimpl/shared"
+	"tailscale.com/drive/driveimpl/shared"
 	"tailscale.com/tstime"
 )
 

drive/driveimpl/dirfs/dirfs_test.go

@@ -15,7 +15,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/tailscale/xnet/webdav"
-	"tailscale.com/tailfs/tailfsimpl/shared"
+	"tailscale.com/drive/driveimpl/shared"
 	"tailscale.com/tstest"
 )
 

drive/driveimpl/dirfs/mkdir.go

@@ -7,7 +7,7 @@ import (
 	"context"
 	"os"
 
-	"tailscale.com/tailfs/tailfsimpl/shared"
+	"tailscale.com/drive/driveimpl/shared"
 )
 
 // Mkdir implements webdav.FileSystem. All attempts to Mkdir a directory that

drive/driveimpl/dirfs/openfile.go

@@ -9,7 +9,7 @@ import (
 	"os"
 
 	"github.com/tailscale/xnet/webdav"
-	"tailscale.com/tailfs/tailfsimpl/shared"
+	"tailscale.com/drive/driveimpl/shared"
 )
 
 // OpenFile implements interface webdav.Filesystem.