add 0x3400 fallback for dante unicast subscription discovery

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
Ian Gulliver
2026-01-23 17:32:29 -08:00
parent fdb8740a0a
commit 71aa3bfc3e

View File

@@ -204,6 +204,9 @@ func (t *Tendrils) queryDanteDeviceWithPort(ip net.IP, port int) *DanteDeviceInf
if info.RxChannelCount > 0 || info.TxChannelCount > 0 {
info.Subscriptions, info.HasMulticast = t.queryDanteSubscriptions(conn, ip, info.RxChannelCount, info.TxChannelCount)
if t.DebugDante {
log.Printf("[dante] %s: 0x3000 returned %d subscriptions, hasMulticast=%v", ip, len(info.Subscriptions), info.HasMulticast)
}
if len(info.Subscriptions) == 0 && info.RxChannelCount > 0 {
info.Subscriptions = t.queryDanteSubscriptions3400(conn, ip, info.RxChannelCount)
}
@@ -252,6 +255,26 @@ func buildDantePacket(cmd uint16, args []byte) []byte {
return pkt
}
func buildDantePacket28(cmd uint16, args []byte) []byte {
seq := nextDanteSeq()
argLen := len(args)
totalLen := 10 + argLen
pkt := make([]byte, totalLen)
pkt[0] = 0x28
pkt[1] = byte(seq & 0xff)
binary.BigEndian.PutUint16(pkt[2:4], uint16(totalLen))
binary.BigEndian.PutUint16(pkt[4:6], seq)
binary.BigEndian.PutUint16(pkt[6:8], cmd)
pkt[8] = 0x00
pkt[9] = 0x00
if argLen > 0 {
copy(pkt[10:], args)
}
return pkt
}
func (t *Tendrils) sendDanteCommand(conn *net.UDPConn, ip net.IP, cmd uint16, args []byte) []byte {
pkt := buildDantePacket(cmd, args)
@@ -278,6 +301,25 @@ func (t *Tendrils) sendDanteCommand(conn *net.UDPConn, ip net.IP, cmd uint16, ar
return buf[:n]
}
func (t *Tendrils) sendDanteCommand28(conn *net.UDPConn, ip net.IP, cmd uint16, args []byte) []byte {
pkt := buildDantePacket28(cmd, args)
conn.SetWriteDeadline(time.Now().Add(500 * time.Millisecond))
_, err := conn.Write(pkt)
if err != nil {
return nil
}
conn.SetReadDeadline(time.Now().Add(1 * time.Second))
buf := make([]byte, 4096)
n, err := conn.Read(buf)
if err != nil {
return nil
}
return buf[:n]
}
func (t *Tendrils) queryDanteDeviceName(conn *net.UDPConn, ip net.IP) string {
// 0x1003 returns device info - name position varies by device
resp := t.sendDanteCommand(conn, ip, 0x1003, nil)
@@ -457,6 +499,9 @@ func extractNullTerminatedString(data []byte, offset int) string {
}
func (t *Tendrils) queryDanteSubscriptions3400(conn *net.UDPConn, ip net.IP, rxCount int) []DanteSubscription {
if t.DebugDante {
log.Printf("[dante] %s: trying 0x3400 fallback, rxCount=%d", ip, rxCount)
}
var subscriptions []DanteSubscription
pagesNeeded := (rxCount + 15) / 16
@@ -465,70 +510,112 @@ func (t *Tendrils) queryDanteSubscriptions3400(conn *net.UDPConn, ip net.IP, rxC
pageNum := page + 1
args := make([]byte, 24)
args[7] = 0x01
binary.BigEndian.PutUint16(args[8:10], uint16(pageNum))
if startChannel == 1 {
binary.BigEndian.PutUint16(args[8:10], 0x0001)
} else {
binary.BigEndian.PutUint16(args[8:10], 0x0003)
}
binary.BigEndian.PutUint16(args[10:12], uint16(startChannel))
resp := t.sendDanteCommand(conn, ip, 0x3400, args)
if resp == nil || len(resp) < 44 {
if t.DebugDante {
log.Printf("[dante] %s: 0x3400 page %d: no response or too short", ip, pageNum)
}
resp := t.sendDanteCommand28(conn, ip, 0x3400, args)
if resp == nil {
continue
}
if len(resp) < 48 {
continue
}
if t.DebugDante {
log.Printf("[dante] %s: 0x3400 page %d: got %d bytes", ip, pageNum, len(resp))
}
status := binary.BigEndian.Uint16(resp[8:10])
if status != 0x8112 && status != 0x0001 {
if t.DebugDante {
log.Printf("[dante] %s: 0x3400 status=0x%04x", ip, status)
}
continue
}
recordCount := 0
for i := 12; i < 44 && i+1 < len(resp); i += 2 {
for i := 18; i < 50 && i+1 < len(resp); i += 2 {
offset := int(binary.BigEndian.Uint16(resp[i : i+2]))
if offset == 0 {
break
}
recordCount++
}
if t.DebugDante {
log.Printf("[dante] %s: 0x3400 page %d: found %d records", ip, pageNum, recordCount)
}
lastDeviceName := ""
for i := 0; i < recordCount; i++ {
offsetPos := 12 + i*2
offsetPos := 18 + i*2
if offsetPos+2 > len(resp) {
break
}
recordOffset := int(binary.BigEndian.Uint16(resp[offsetPos : offsetPos+2]))
if recordOffset == 0 || recordOffset >= len(resp) {
rawOffset := int(binary.BigEndian.Uint16(resp[offsetPos : offsetPos+2]))
recordOffset := rawOffset - 30
if recordOffset < 0 || recordOffset+24 >= len(resp) {
continue
}
rxChannelName := extractNullTerminatedString(resp, recordOffset)
if rxChannelName == "" {
continue
}
txDeviceStart := recordOffset + len(rxChannelName) + 1
txDeviceName := extractNullTerminatedString(resp, txDeviceStart)
if txDeviceName == "" {
continue
}
txChannelName := ""
searchStart := txDeviceStart + len(txDeviceName) + 1
for j := searchStart; j < recordOffset+64 && j < len(resp)-1; j++ {
if resp[j] >= '0' && resp[j] <= '9' {
candidate := extractNullTerminatedString(resp, j)
if len(candidate) >= 1 && len(candidate) <= 4 {
txChannelName = candidate
var txDeviceName, txChannelName string
firstByte := resp[recordOffset]
if firstByte >= 0x20 && firstByte < 0x7f {
txChannelName = extractNullTerminatedString(resp, recordOffset)
txDeviceName = extractNullTerminatedString(resp, recordOffset+len(txChannelName)+1)
} else {
stringStart := -1
for j := recordOffset + 10; j < recordOffset+24 && j+3 < len(resp); j++ {
if resp[j] == 0x02 && resp[j+1] == 0x02 && resp[j+2] == 0x00 && resp[j+3] == 0x00 {
stringStart = j + 4
break
}
}
if stringStart >= 0 && stringStart < len(resp) {
str1 := extractNullTerminatedString(resp, stringStart)
str2 := extractNullTerminatedString(resp, stringStart+len(str1)+1)
hasLetter := func(s string) bool {
for _, c := range s {
if (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') {
return true
}
}
return false
}
if !hasLetter(str1) && !hasLetter(str2) {
continue
}
noDeviceIndicator := stringStart >= 6 && resp[stringStart-6] == 0x00 && resp[stringStart-5] == 0x00
str2IsNumeric := len(str2) > 0
for _, c := range str2 {
if c < '0' || c > '9' {
str2IsNumeric = false
break
}
}
if noDeviceIndicator && str2IsNumeric && lastDeviceName != "" {
txChannelName = str1
txDeviceName = lastDeviceName
} else if str2IsNumeric {
txDeviceName = str1
txChannelName = str2
} else if hasLetter(str2) {
txDeviceName = str2
txChannelName = str1
} else {
txChannelName = str1
txDeviceName = lastDeviceName
}
}
}
if txDeviceName == "" {
continue
}
lastDeviceName = txDeviceName
rxChannel := startChannel + i
if t.DebugDante {
log.Printf("[dante] %s: 0x3400 sub: rx=%d rxName=%q txDev=%q txCh=%q", ip, rxChannel, rxChannelName, txDeviceName, txChannelName)
log.Printf("[dante] %s: 0x3400 sub: rx=%d txDev=%q txCh=%q", ip, rxChannel, txDeviceName, txChannelName)
}
subscriptions = append(subscriptions, DanteSubscription{