Fix ArtPollReply to advertise both input and output universes

artnet/discovery.go

@@ -20,25 +20,27 @@ type Node struct {
 
 // Discovery handles ArtNet node discovery
 type Discovery struct {
-	sender      *Sender
-	nodes       map[string]*Node // keyed by IP string
-	nodesMu     sync.RWMutex
-	localIP     [4]byte
-	shortName   string
-	longName    string
-	universes   []Universe
-	pollTargets []*net.UDPAddr
-	done        chan struct{}
+	sender       *Sender
+	nodes        map[string]*Node // keyed by IP string
+	nodesMu      sync.RWMutex
+	localIP      [4]byte
+	shortName    string
+	longName     string
+	inputUnivs   []Universe // universes we transmit TO (SwIn)
+	outputUnivs  []Universe // universes we receive FROM (SwOut)
+	pollTargets  []*net.UDPAddr
+	done         chan struct{}
 }
 
 // NewDiscovery creates a new discovery handler
-func NewDiscovery(sender *Sender, shortName, longName string, universes []Universe, pollTargets []*net.UDPAddr) *Discovery {
+func NewDiscovery(sender *Sender, shortName, longName string, inputUnivs, outputUnivs []Universe, pollTargets []*net.UDPAddr) *Discovery {
 	return &Discovery{
 		sender:      sender,
 		nodes:       make(map[string]*Node),
 		shortName:   shortName,
 		longName:    longName,
-		universes:   universes,
+		inputUnivs:  inputUnivs,
+		outputUnivs: outputUnivs,
 		pollTargets: pollTargets,
 		done:        make(chan struct{}),
 	}
@@ -185,10 +187,29 @@ func (d *Discovery) HandlePollReply(src *net.UDPAddr, pkt *PollReplyPacket) {
 
 // HandlePoll processes an incoming ArtPoll and responds
 func (d *Discovery) HandlePoll(src *net.UDPAddr) {
-	// Respond with our info
-	err := d.sender.SendPollReply(src, d.localIP, d.shortName, d.longName, d.universes)
-	if err != nil {
-		log.Printf("[->artnet] pollreply error: dst=%s err=%v", src.IP, err)
+	d.sendPollReplies(src, d.inputUnivs, true)
+	d.sendPollReplies(src, d.outputUnivs, false)
+}
+
+func (d *Discovery) sendPollReplies(dst *net.UDPAddr, universes []Universe, isInput bool) {
+	groups := make(map[uint16][]Universe)
+	for _, u := range universes {
+		key := uint16(u.Net())<<8 | uint16(u.SubNet())<<4
+		groups[key] = append(groups[key], u)
+	}
+
+	for _, univs := range groups {
+		for i := 0; i < len(univs); i += 4 {
+			end := i + 4
+			if end > len(univs) {
+				end = len(univs)
+			}
+			chunk := univs[i:end]
+			err := d.sender.SendPollReply(dst, d.localIP, d.shortName, d.longName, chunk, isInput)
+			if err != nil {
+				log.Printf("[->artnet] pollreply error: dst=%s err=%v", dst.IP, err)
+			}
+		}
 	}
 }
 

artnet/protocol.go

@@ -254,7 +254,8 @@ func BuildPollPacket() []byte {
 }
 
 // BuildPollReplyPacket creates an ArtPollReply packet
-func BuildPollReplyPacket(ip [4]byte, shortName, longName string, universes []Universe) []byte {
+// isInput: true = we transmit to network (SwIn), false = we receive from network (SwOut)
+func BuildPollReplyPacket(ip [4]byte, shortName, longName string, universes []Universe, isInput bool) []byte {
 	buf := make([]byte, 239)
 
 	copy(buf[0:8], ArtNetID[:])
@@ -263,17 +264,14 @@ func BuildPollReplyPacket(ip [4]byte, shortName, longName string, universes []Un
 	binary.LittleEndian.PutUint16(buf[14:16], Port)
 	binary.BigEndian.PutUint16(buf[16:18], ProtocolVersion)
 
-	// Net/Subnet from first universe if available
 	if len(universes) > 0 {
 		buf[18] = universes[0].Net()
 		buf[19] = universes[0].SubNet()
 	}
 
-	// Names
 	copy(buf[26:44], shortName)
 	copy(buf[44:108], longName)
 
-	// Ports
 	numPorts := len(universes)
 	if numPorts > 4 {
 		numPorts = 4
@@ -281,9 +279,15 @@ func BuildPollReplyPacket(ip [4]byte, shortName, longName string, universes []Un
 	buf[173] = byte(numPorts)
 
 	for i := 0; i < numPorts; i++ {
-		buf[174+i] = 0xC0 // Output, can output DMX
-		buf[182+i] = 0x80 // Data transmitted
-		buf[190+i] = universes[i].Universe()
+		if isInput {
+			buf[174+i] = 0x40 // Can input to Art-Net (we transmit)
+			buf[178+i] = 0x80 // Data received
+			buf[186+i] = universes[i].Universe()
+		} else {
+			buf[174+i] = 0x80 // Can output from Art-Net (we receive)
+			buf[182+i] = 0x80 // Data transmitted
+			buf[190+i] = universes[i].Universe()
+		}
 	}
 
 	buf[200] = 0x00 // StNode

artnet/sender.go

@@ -56,8 +56,8 @@ func (s *Sender) SendPoll(addr *net.UDPAddr) error {
 }
 
 // SendPollReply sends an ArtPollReply to a specific address
-func (s *Sender) SendPollReply(addr *net.UDPAddr, localIP [4]byte, shortName, longName string, universes []Universe) error {
-	pkt := BuildPollReplyPacket(localIP, shortName, longName, universes)
+func (s *Sender) SendPollReply(addr *net.UDPAddr, localIP [4]byte, shortName, longName string, universes []Universe, isInput bool) error {
+	pkt := BuildPollReplyPacket(localIP, shortName, longName, universes, isInput)
 	_, err := s.conn.WriteToUDP(pkt, addr)
 	return err
 }