cmd/tailscale,ipn,tailcfg: add tailscale advertise subcommand behind envknob (#13734)

Signed-off-by: Naman Sood <mail@nsood.in>

ipn/ipn_clone.go

@@ -27,6 +27,7 @@ func (src *Prefs) Clone() *Prefs {
 	*dst = *src
 	dst.AdvertiseTags = append(src.AdvertiseTags[:0:0], src.AdvertiseTags...)
 	dst.AdvertiseRoutes = append(src.AdvertiseRoutes[:0:0], src.AdvertiseRoutes...)
+	dst.AdvertiseServices = append(src.AdvertiseServices[:0:0], src.AdvertiseServices...)
 	if src.DriveShares != nil {
 		dst.DriveShares = make([]*drive.Share, len(src.DriveShares))
 		for i := range dst.DriveShares {
@@ -61,6 +62,7 @@ var _PrefsCloneNeedsRegeneration = Prefs(struct {
 	ForceDaemon            bool
 	Egg                    bool
 	AdvertiseRoutes        []netip.Prefix
+	AdvertiseServices      []string
 	NoSNAT                 bool
 	NoStatefulFiltering    opt.Bool
 	NetfilterMode          preftype.NetfilterMode

ipn/ipn_view.go

@@ -85,6 +85,9 @@ func (v PrefsView) Egg() bool                                   { return v.ж.Eg
 func (v PrefsView) AdvertiseRoutes() views.Slice[netip.Prefix] {
 	return views.SliceOf(v.ж.AdvertiseRoutes)
 }
+func (v PrefsView) AdvertiseServices() views.Slice[string] {
+	return views.SliceOf(v.ж.AdvertiseServices)
+}
 func (v PrefsView) NoSNAT() bool                          { return v.ж.NoSNAT }
 func (v PrefsView) NoStatefulFiltering() opt.Bool         { return v.ж.NoStatefulFiltering }
 func (v PrefsView) NetfilterMode() preftype.NetfilterMode { return v.ж.NetfilterMode }
@@ -120,6 +123,7 @@ var _PrefsViewNeedsRegeneration = Prefs(struct {
 	ForceDaemon            bool
 	Egg                    bool
 	AdvertiseRoutes        []netip.Prefix
+	AdvertiseServices      []string
 	NoSNAT                 bool
 	NoStatefulFiltering    opt.Bool
 	NetfilterMode          preftype.NetfilterMode

ipn/prefs.go

@@ -179,6 +179,12 @@ type Prefs struct {
 	// node.
 	AdvertiseRoutes []netip.Prefix
 
+	// AdvertiseServices specifies the list of services that this
+	// node can serve as a destination for. Note that an advertised
+	// service must still go through the approval process from the
+	// control server.
+	AdvertiseServices []string
+
 	// NoSNAT specifies whether to source NAT traffic going to
 	// destinations in AdvertiseRoutes. The default is to apply source
 	// NAT, which makes the traffic appear to come from the router
@@ -319,6 +325,7 @@ type MaskedPrefs struct {
 	ForceDaemonSet            bool                `json:",omitempty"`
 	EggSet                    bool                `json:",omitempty"`
 	AdvertiseRoutesSet        bool                `json:",omitempty"`
+	AdvertiseServicesSet      bool                `json:",omitempty"`
 	NoSNATSet                 bool                `json:",omitempty"`
 	NoStatefulFilteringSet    bool                `json:",omitempty"`
 	NetfilterModeSet          bool                `json:",omitempty"`
@@ -527,6 +534,9 @@ func (p *Prefs) pretty(goos string) string {
 	if len(p.AdvertiseTags) > 0 {
 		fmt.Fprintf(&sb, "tags=%s ", strings.Join(p.AdvertiseTags, ","))
 	}
+	if len(p.AdvertiseServices) > 0 {
+		fmt.Fprintf(&sb, "services=%s ", strings.Join(p.AdvertiseServices, ","))
+	}
 	if goos == "linux" {
 		fmt.Fprintf(&sb, "nf=%v ", p.NetfilterMode)
 	}
@@ -598,6 +608,7 @@ func (p *Prefs) Equals(p2 *Prefs) bool {
 		p.ForceDaemon == p2.ForceDaemon &&
 		compareIPNets(p.AdvertiseRoutes, p2.AdvertiseRoutes) &&
 		compareStrings(p.AdvertiseTags, p2.AdvertiseTags) &&
+		compareStrings(p.AdvertiseServices, p2.AdvertiseServices) &&
 		p.Persist.Equals(p2.Persist) &&
 		p.ProfileName == p2.ProfileName &&
 		p.AutoUpdate.Equals(p2.AutoUpdate) &&

ipn/prefs_test.go

@@ -54,6 +54,7 @@ func TestPrefsEqual(t *testing.T) {
 		"ForceDaemon",
 		"Egg",
 		"AdvertiseRoutes",
+		"AdvertiseServices",
 		"NoSNAT",
 		"NoStatefulFiltering",
 		"NetfilterMode",
@@ -330,6 +331,16 @@ func TestPrefsEqual(t *testing.T) {
 			&Prefs{NetfilterKind: ""},
 			false,
 		},
+		{
+			&Prefs{AdvertiseServices: []string{"svc:tux", "svc:xenia"}},
+			&Prefs{AdvertiseServices: []string{"svc:tux", "svc:xenia"}},
+			true,
+		},
+		{
+			&Prefs{AdvertiseServices: []string{"svc:tux", "svc:xenia"}},
+			&Prefs{AdvertiseServices: []string{"svc:tux", "svc:amelie"}},
+			false,
+		},
 	}
 	for i, tt := range tests {
 		got := tt.a.Equals(tt.b)