implement router multicast, working on host heartbeat

host/lux_host.go

@@ -3,6 +3,7 @@ package host
 import (
 	"lux/crypto"
 	"lux/net"
+	"lux/proto"
 )
 
 // interface to get data for options. may be blocking
@@ -33,5 +34,35 @@ func (host *LuxHost) AddOptionProvider(provider LuxOptionProvider) {
 }
 
 func (host *LuxHost) CaptureState() (LuxState, error) {
-	return LuxState{}, nil
+	state := LuxState{
+		Hostname: host.hostname,
+		Options:  make(map[LuxOptionType]LuxOption),
+	}
+
+	for _, provider := range host.providers {
+		opt, err := provider.Provide()
+		if err != nil {
+			return state, err
+		}
+
+		state.Options[opt.Type()] = opt
+	}
+
+	return state, nil
+}
+
+func (host *LuxHost) Heartbeat() error {
+	state, err := host.CaptureState()
+	if err != nil {
+		return err
+	}
+
+	packet := net.LuxPacket{
+		Target: host.router.GetThisKey().Id,
+		Type:   0x6969, // FIXME
+		Buffer: proto.NewLuxBuffer(),
+	}
+
+	state.Write(&packet.Buffer)
+	return host.router.Multicast(packet)
 }

net/lux_packet.go

@@ -17,6 +17,9 @@ const LUX_PROTO_PACKET_HDRLEN = proto.LUX_PROTO_ID_SIZE + 2
 // Buffer contains LuxBuffer with stripped headers
 // NOTE: Packets are always padded, so payloads may be
 // bigger than expected and contain trailing bytes
+
+// Target (ID) is rather confusing. What it actually describes is
+// associated key with route.
 type LuxPacket struct {
 	Target      proto.LuxID
 	Type        uint

net/lux_router.go

@@ -282,5 +282,24 @@ func (r *LuxRouter) Send(packet LuxPacket) error {
 		return err
 	}
 
+	// TODO: close route if it fails?
 	return route.Associated.Send(dgram)
 }
+
+func (r *LuxRouter) Multicast(packet LuxPacket) error {
+	for _, route := range r.routes {
+		if bytes.Equal(route.Key.Id.UUID[:], packet.Target.UUID[:]) {
+			dgram, err := EncryptLuxPacket(packet, route.Key, route.Destination)
+			if err != nil {
+				return err
+			}
+
+			if err = route.Associated.Send(dgram); err != nil {
+				// TODO: close route if it fails?
+				return err
+			}
+		}
+	}
+
+	return nil
+}