tailcfg: include ShieldsUp in HostInfo

ipn/local.go

@@ -1303,6 +1303,7 @@ func applyPrefsToHostinfo(hi *tailcfg.Hostinfo, prefs *Prefs) {
 	if m := prefs.DeviceModel; m != "" {
 		hi.DeviceModel = m
 	}
+	hi.ShieldsUp = prefs.ShieldsUp
 }
 
 // enterState transitions the backend into newState, updating internal

ipn/prefs.go

@@ -54,7 +54,7 @@ type Prefs struct {
 	// ShieldsUp indicates whether to block all incoming connections,
 	// regardless of the control-provided packet filter. If false, we
 	// use the packet filter as provided. If true, we block incoming
-	// connections.
+	// connections. This overrides tailcfg.Hostinfo's ShieldsUp.
 	ShieldsUp bool
 
 	// AdvertiseTags specifies groups that this node wants to join, for