ipn: only send services in Hostinfo if Tailnet has opted-in to services collection (#1107)

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>

control/controlclient/direct.go

@@ -765,6 +765,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*Netw
 			DNS:             resp.DNSConfig,
 			Hostinfo:        resp.Node.Hostinfo,
 			PacketFilter:    lastParsedPacketFilter,
+			CollectServices: resp.CollectServices,
 			DERPMap:         lastDERPMap,
 			Debug:           resp.Debug,
 		}

control/controlclient/netmap.go

@@ -39,6 +39,12 @@ type NetworkMap struct {
 	Hostinfo      tailcfg.Hostinfo
 	PacketFilter  []filter.Match
 
+	// CollectServices reports whether this node's Tailnet has
+	// requested that info about services be included in HostInfo.
+	// If set, Hostinfo.ShieldsUp blocks services collection; that
+	// takes precedence over this field.
+	CollectServices bool
+
 	// DERPMap is the last DERP server map received. It's reused
 	// between updates and should not be modified.
 	DERPMap *tailcfg.DERPMap

ipn/local.go

@@ -1015,16 +1015,18 @@ func (b *LocalBackend) parseWgStatusLocked(s *wgengine.Status) (ret EngineStatus
 	return ret
 }
 
-// shieldsAreUp returns whether user preferences currently request
-// "shields up" mode, which disallows all inbound connections.
-func (b *LocalBackend) shieldsAreUp() bool {
+// shouldUploadServices reports whether this node should include services
+// in Hostinfo. When the user preferences currently request "shields up"
+// mode, all inbound connections are refused, so services are not reported.
+// Otherwise, shouldUploadServices respects NetMap.CollectServices.
+func (b *LocalBackend) shouldUploadServices() bool {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 
-	if b.prefs == nil {
-		return true // default to safest setting
+	if b.prefs == nil || b.netMap == nil {
+		return false // default to safest setting
 	}
-	return b.prefs.ShieldsUp
+	return !b.prefs.ShieldsUp && b.netMap.CollectServices
 }
 
 func (b *LocalBackend) SetCurrentUserID(uid string) {
@@ -1124,9 +1126,7 @@ func (b *LocalBackend) SetPrefs(newp *Prefs) {
 // painstakingly constructing it in twelvety other places.
 func (b *LocalBackend) doSetHostinfoFilterServices(hi *tailcfg.Hostinfo) {
 	hi2 := *hi
-	if b.shieldsAreUp() {
-		// No local services are available, since ShieldsUp will block
-		// them all.
+	if !b.shouldUploadServices() {
 		hi2.Services = []tailcfg.Service{}
 	}
 

tailcfg/tailcfg.go

@@ -665,6 +665,10 @@ type MapResponse struct {
 	// forms are coming later.
 	Domain string
 
+	// CollectServices reports whether this node's Tailnet has
+	// requested that info about services be included in HostInfo.
+	CollectServices bool `json:",omitempty"`
+
 	// PacketFilter are the firewall rules.
 	//
 	// For MapRequest.Version >= 6, a nil value means the most