theater/tendrils
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add shure slp discovery and comma-separate group member lists

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
Ian Gulliver
2026-01-23 09:47:51 -08:00
parent 6394b55191
commit c7db24b1fd
5 changed files with 149 additions and 4 deletions
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6
artnet.go
View File

@@ -348,16 +348,16 @@ func (a *ArtNetNodes) LogAll() {
var parts []string
if len(ins) > 0 {
sort.Slice(ins, func(i, j int) bool { return sortorder.NaturalLess(ins[i], ins[j]) })
parts = append(parts, fmt.Sprintf("in:%v", ins))
parts = append(parts, fmt.Sprintf("in: %s", strings.Join(ins, ", ")))
}
if len(outs) > 0 {
sort.Slice(outs, func(i, j int) bool { return sortorder.NaturalLess(outs[i], outs[j]) })
parts = append(parts, fmt.Sprintf("out:%v", outs))
parts = append(parts, fmt.Sprintf("out: %s", strings.Join(outs, ", ")))
}
net := (u >> 8) & 0x7f
subnet := (u >> 4) & 0x0f
universe := u & 0x0f
log.Printf("[sigusr1] artnet:%d (%d/%d/%d) %s", u, net, subnet, universe, strings.Join(parts, " "))
log.Printf("[sigusr1] artnet:%d (%d/%d/%d) %s", u, net, subnet, universe, strings.Join(parts, "; "))
}
}

4
cmd/tendrils/main.go
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@@ -16,6 +16,7 @@ func main() {
noArtNet := flag.Bool("no-artnet", false, "disable Art-Net discovery")
noDante := flag.Bool("no-dante", false, "disable Dante discovery")
noBMD := flag.Bool("no-bmd", false, "disable Blackmagic discovery")
noShure := flag.Bool("no-shure", false, "disable Shure discovery")
logEvents := flag.Bool("log-events", false, "log node events")
logNodes := flag.Bool("log-nodes", false, "log full node details on changes")
debugARP := flag.Bool("debug-arp", false, "debug ARP discovery")
@@ -26,6 +27,7 @@ func main() {
debugArtNet := flag.Bool("debug-artnet", false, "debug Art-Net discovery")
debugDante := flag.Bool("debug-dante", false, "debug Dante discovery")
debugBMD := flag.Bool("debug-bmd", false, "debug Blackmagic discovery")
debugShure := flag.Bool("debug-shure", false, "debug Shure discovery")
flag.Parse()
t := tendrils.New()
@@ -38,6 +40,7 @@ func main() {
t.DisableArtNet = *noArtNet
t.DisableDante = *noDante
t.DisableBMD = *noBMD
t.DisableShure = *noShure
t.LogEvents = *logEvents
t.LogNodes = *logNodes
t.DebugARP = *debugARP
@@ -48,5 +51,6 @@ func main() {
t.DebugArtNet = *debugArtNet
t.DebugDante = *debugDante
t.DebugBMD = *debugBMD
t.DebugShure = *debugShure
t.Run()
}

3
nodes.go
View File

@@ -6,6 +6,7 @@ import (
"log"
"net"
"sort"
"strings"
"sync"
"time"
@@ -710,7 +711,7 @@ func (n *Nodes) LogAll() {
sort.Slice(memberNames, func(i, j int) bool {
return sortorder.NaturalLess(memberNames[i], memberNames[j])
})
log.Printf("[sigusr1] %s: %v", gm.Group.Name(), memberNames)
log.Printf("[sigusr1] %s: %s", gm.Group.Name(), strings.Join(memberNames, ", "))
}
}

135
shure.go Normal file
View File

@@ -0,0 +1,135 @@
package tendrils
import (
"context"
"encoding/binary"
"log"
"net"
"regexp"
"time"
)
var acnUACNRegex = regexp.MustCompile(`\(acn-uacn=([^)]+)\)`)
const (
shureMulticastAddr = "239.255.254.253:8427"
)
func (t *Tendrils) listenShure(ctx context.Context, iface net.Interface) {
addr, err := net.ResolveUDPAddr("udp4", shureMulticastAddr)
if err != nil {
log.Printf("[ERROR] failed to resolve shure address: %v", err)
return
}
conn, err := net.ListenMulticastUDP("udp4", &iface, addr)
if err != nil {
if t.DebugShure {
log.Printf("[shure] %s: failed to listen: %v", iface.Name, err)
}
return
}
defer conn.Close()
go t.sendShureDiscovery(ctx, iface.Name, conn)
buf := make([]byte, 4096)
for {
select {
case <-ctx.Done():
return
default:
}
conn.SetReadDeadline(time.Now().Add(1 * time.Second))
n, src, err := conn.ReadFromUDP(buf)
if err != nil {
if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
continue
}
continue
}
t.handleShurePacket(iface.Name, src.IP, buf[:n])
}
}
func (t *Tendrils) sendShureDiscovery(ctx context.Context, ifaceName string, conn *net.UDPConn) {
dest := &net.UDPAddr{IP: net.IPv4(239, 255, 254, 253), Port: 8427}
ticker := time.NewTicker(30 * time.Second)
defer ticker.Stop()
t.sendShureQuery(ifaceName, conn, dest)
for {
select {
case <-ctx.Done():
return
case <-ticker.C:
t.sendShureQuery(ifaceName, conn, dest)
}
}
}
func (t *Tendrils) sendShureQuery(ifaceName string, conn *net.UDPConn, dest *net.UDPAddr) {
// SLP Service Type Request (SrvTypeRqst)
// This asks "what service types are available?"
langTag := []byte("en")
// Build SLP v2 header + SrvTypeRqst body
// Header: version(1) + function(1) + length(3) + flags(2) + next-ext(3) + xid(2) + lang-len(2) + lang
// SrvTypeRqst body: PR list len(2) + PR list + naming auth len(2) + naming auth + scope list len(2) + scope list
headerLen := 14 + len(langTag)
bodyLen := 2 + 0 + 2 + 0 + 2 + 7 // empty PR list, empty naming auth, "default" scope
totalLen := headerLen + bodyLen
pkt := make([]byte, totalLen)
pkt[0] = 0x02 // SLP version 2
pkt[1] = 0x09 // Function: SrvTypeRqst (9)
pkt[2] = byte(totalLen >> 16) // Length (3 bytes)
pkt[3] = byte(totalLen >> 8)
pkt[4] = byte(totalLen)
pkt[5] = 0x00 // Flags (2 bytes) - multicast
pkt[6] = 0x20
pkt[7] = 0x00 // Next ext offset (3 bytes)
pkt[8] = 0x00
pkt[9] = 0x00
binary.BigEndian.PutUint16(pkt[10:12], 0x0001) // XID
binary.BigEndian.PutUint16(pkt[12:14], uint16(len(langTag)))
copy(pkt[14:], langTag)
offset := 14 + len(langTag)
binary.BigEndian.PutUint16(pkt[offset:], 0) // PR list length (0)
offset += 2
binary.BigEndian.PutUint16(pkt[offset:], 0) // Naming authority length (0 = IANA)
offset += 2
binary.BigEndian.PutUint16(pkt[offset:], 7) // Scope list length
offset += 2
copy(pkt[offset:], "default")
conn.WriteToUDP(pkt, dest)
if t.DebugShure {
log.Printf("[shure] %s: sent slp discovery query", ifaceName)
}
}
func (t *Tendrils) handleShurePacket(ifaceName string, srcIP net.IP, data []byte) {
if t.DebugShure {
log.Printf("[shure] %s: packet from %s (%d bytes): %q", ifaceName, srcIP, len(data), data)
}
match := acnUACNRegex.FindSubmatch(data)
if match == nil {
return
}
name := string(match[1])
if t.DebugShure {
log.Printf("[shure] %s: found device %s at %s", ifaceName, name, srcIP)
}
t.nodes.Update(nil, nil, []net.IP{srcIP}, "", name, "shure")
}

5
tendrils.go
View File

@@ -24,6 +24,7 @@ type Tendrils struct {
DisableArtNet bool
DisableDante bool
DisableBMD bool
DisableShure bool
LogEvents bool
LogNodes bool
DebugARP bool
@@ -34,6 +35,7 @@ type Tendrils struct {
DebugArtNet bool
DebugDante bool
DebugBMD bool
DebugShure bool
}
func New() *Tendrils {
@@ -205,4 +207,7 @@ func (t *Tendrils) startInterface(ctx context.Context, iface net.Interface) {
if !t.DisableBMD {
go t.listenBMD(ctx, iface)
}
if !t.DisableShure {
go t.listenShure(ctx, iface)
}
}