feature/taildrop, ipn/ipnlocal: remove leftover dup calls to osshare

I'd moved the osshare calls to feature/taildrop hooks, but forgot to
remove them from ipnlocal, or lost them during a rebase.

But then I noticed cmd/tailscaled also had some, so turn those into a
hook.

Updates #12614

Change-Id: I024fb1d27fbcc49c013158882ee5982c2737037d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/k8s-operator/depaware.txt

@@ -936,7 +936,6 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/util/nocasemaps                                from tailscale.com/types/ipproto
      💣 tailscale.com/util/osdiag                                    from tailscale.com/ipn/localapi
    W 💣 tailscale.com/util/osdiag/internal/wsc                       from tailscale.com/util/osdiag
-        tailscale.com/util/osshare                                   from tailscale.com/ipn/ipnlocal
         tailscale.com/util/osuser                                    from tailscale.com/ipn/ipnlocal
         tailscale.com/util/race                                      from tailscale.com/net/dns/resolver
         tailscale.com/util/racebuild                                 from tailscale.com/logpolicy

cmd/tailscaled/depaware.txt

@@ -253,6 +253,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/clientupdate                                   from tailscale.com/client/web+
   LW    tailscale.com/clientupdate/distsign                          from tailscale.com/clientupdate
         tailscale.com/cmd/tailscaled/childproc                       from tailscale.com/cmd/tailscaled+
+        tailscale.com/cmd/tailscaled/tailscaledhooks                 from tailscale.com/cmd/tailscaled+
         tailscale.com/control/controlbase                            from tailscale.com/control/controlhttp+
         tailscale.com/control/controlclient                          from tailscale.com/cmd/tailscaled+
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient

cmd/tailscaled/install_windows.go

@@ -15,9 +15,9 @@ import (
 	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/svc"
 	"golang.org/x/sys/windows/svc/mgr"
+	"tailscale.com/cmd/tailscaled/tailscaledhooks"
 	"tailscale.com/logtail/backoff"
 	"tailscale.com/types/logger"
-	"tailscale.com/util/osshare"
 )
 
 func init() {
@@ -81,8 +81,9 @@ func installSystemDaemonWindows(args []string) (err error) {
 }
 
 func uninstallSystemDaemonWindows(args []string) (ret error) {
-	// Remove file sharing from Windows shell (noop in non-windows)
-	osshare.SetFileSharingEnabled(false, logger.Discard)
+	for _, f := range tailscaledhooks.UninstallSystemDaemonWindows {
+		f()
+	}
 
 	m, err := mgr.Connect()
 	if err != nil {

cmd/tailscaled/tailscaledhooks/tailscaledhooks.go

@@ -0,0 +1,12 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package tailscaledhooks provides hooks for optional features
+// to add to during init that tailscaled calls at runtime.
+package tailscaledhooks
+
+import "tailscale.com/feature"
+
+// UninstallSystemDaemonWindows is called when the Windows
+// system daemon is uninstalled.
+var UninstallSystemDaemonWindows feature.Hooks[func()]

feature/taildrop/ext.go

@@ -12,12 +12,14 @@ import (
 	"maps"
 	"os"
 	"path/filepath"
+	"runtime"
 	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
 
 	"tailscale.com/client/tailscale/apitype"
+	"tailscale.com/cmd/tailscaled/tailscaledhooks"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnext"
 	"tailscale.com/ipn/ipnstate"
@@ -31,6 +33,13 @@ import (
 
 func init() {
 	ipnext.RegisterExtension("taildrop", newExtension)
+
+	if runtime.GOOS == "windows" {
+		tailscaledhooks.UninstallSystemDaemonWindows.Add(func() {
+			// Remove file sharing from Windows shell.
+			osshare.SetFileSharingEnabled(false, logger.Discard)
+		})
+	}
 }
 
 func newExtension(logf logger.Logf, b ipnext.SafeBackend) (ipnext.Extension, error) {

ipn/ipnlocal/local.go

@@ -102,7 +102,6 @@ import (
 	"tailscale.com/util/httpm"
 	"tailscale.com/util/mak"
 	"tailscale.com/util/multierr"
-	"tailscale.com/util/osshare"
 	"tailscale.com/util/osuser"
 	"tailscale.com/util/rands"
 	"tailscale.com/util/set"
@@ -274,7 +273,6 @@ type LocalBackend struct {
 	machinePrivKey key.MachinePrivate
 	tka            *tkaState // TODO(nickkhyl): move to nodeContext
 	state          ipn.State // TODO(nickkhyl): move to nodeContext
-	capFileSharing bool      // whether netMap contains the file sharing capability
 	capTailnetLock bool      // whether netMap contains the tailnet lock capability
 	// hostinfo is mutated in-place while mu is held.
 	hostinfo          *tailcfg.Hostinfo      // TODO(nickkhyl): move to nodeContext
@@ -460,7 +458,6 @@ func NewLocalBackend(logf logger.Logf, logID logid.PublicID, sys *tsd.System, lo
 	}
 
 	envknob.LogCurrent(logf)
-	osshare.SetFileSharingEnabled(false, logf)
 
 	ctx, cancel := context.WithCancel(context.Background())
 	clock := tstime.StdClock{}
@@ -6140,13 +6137,6 @@ func (b *LocalBackend) setNetMapLocked(nm *netmap.NetworkMap) {
 		b.health.SetControlHealth(nil)
 	}
 
-	// Determine if file sharing is enabled
-	fs := nm.HasCap(tailcfg.CapabilityFileSharing)
-	if fs != b.capFileSharing {
-		osshare.SetFileSharingEnabled(fs, b.logf)
-	}
-	b.capFileSharing = fs
-
 	if nm.HasCap(tailcfg.NodeAttrLinuxMustUseIPTables) {
 		b.capForcedNetfilter = "iptables"
 	} else if nm.HasCap(tailcfg.NodeAttrLinuxMustUseNfTables) {

ipn/ipnlocal/peerapi_test.go

@@ -67,18 +67,16 @@ func bodyNotContains(sub string) check {
 
 func TestHandlePeerAPI(t *testing.T) {
 	tests := []struct {
-		name       string
-		isSelf     bool // the peer sending the request is owned by us
-		capSharing bool // self node has file sharing capability
-		debugCap   bool // self node has debug capability
-		reqs       []*http.Request
-		checks     []check
+		name     string
+		isSelf   bool // the peer sending the request is owned by us
+		debugCap bool // self node has debug capability
+		reqs     []*http.Request
+		checks   []check
 	}{
 		{
-			name:       "not_peer_api",
-			isSelf:     true,
-			capSharing: true,
-			reqs:       []*http.Request{httptest.NewRequest("GET", "/", nil)},
+			name:   "not_peer_api",
+			isSelf: true,
+			reqs:   []*http.Request{httptest.NewRequest("GET", "/", nil)},
 			checks: checks(
 				httpStatus(200),
 				bodyContains("This is my Tailscale device."),
@@ -86,10 +84,9 @@ func TestHandlePeerAPI(t *testing.T) {
 			),
 		},
 		{
-			name:       "not_peer_api_not_owner",
-			isSelf:     false,
-			capSharing: true,
-			reqs:       []*http.Request{httptest.NewRequest("GET", "/", nil)},
+			name:   "not_peer_api_not_owner",
+			isSelf: false,
+			reqs:   []*http.Request{httptest.NewRequest("GET", "/", nil)},
 			checks: checks(
 				httpStatus(200),
 				bodyContains("This is my Tailscale device."),
@@ -160,9 +157,8 @@ func TestHandlePeerAPI(t *testing.T) {
 			}
 			var e peerAPITestEnv
 			lb := &LocalBackend{
-				logf:           e.logBuf.Logf,
-				capFileSharing: tt.capSharing,
-				clock:          &tstest.Clock{},
+				logf:  e.logBuf.Logf,
+				clock: &tstest.Clock{},
 			}
 			lb.currentNode().SetNetMap(&netmap.NetworkMap{SelfNode: selfNode.View()})
 			e.ph = &peerAPIHandler{

tsnet/depaware.txt

@@ -365,7 +365,6 @@ tailscale.com/tsnet dependencies: (generated by github.com/tailscale/depaware)
         tailscale.com/util/nocasemaps                                from tailscale.com/types/ipproto
      💣 tailscale.com/util/osdiag                                    from tailscale.com/ipn/localapi
    W 💣 tailscale.com/util/osdiag/internal/wsc                       from tailscale.com/util/osdiag
-        tailscale.com/util/osshare                                   from tailscale.com/ipn/ipnlocal
         tailscale.com/util/osuser                                    from tailscale.com/ipn/ipnlocal
         tailscale.com/util/race                                      from tailscale.com/net/dns/resolver
         tailscale.com/util/racebuild                                 from tailscale.com/logpolicy

tstest/integration/tailscaled_deps_test_windows.go

@@ -20,6 +20,7 @@ import (
 	_ "golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
 	_ "tailscale.com/client/local"
 	_ "tailscale.com/cmd/tailscaled/childproc"
+	_ "tailscale.com/cmd/tailscaled/tailscaledhooks"
 	_ "tailscale.com/control/controlclient"
 	_ "tailscale.com/derp/derphttp"
 	_ "tailscale.com/drive/driveimpl"