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|
package main
import (
"encoding/binary"
"fmt"
"os"
"path/filepath"
"syscall"
"golang.org/x/sys/unix"
)
// Message header is 16 bytes
type MessageHeader struct {
ID uint32 // Object ID (0 for core)
Opcode uint8 // Method/event opcode
Size uint32 // Size of payload (24 bits, but we use uint32)
HeaderSeq uint32 // Message sequence counter (no semantic meaning, just increments)
NFds uint32 // Number of file descriptors
}
// EncodeHeader encodes the message header to 16 bytes
func (h *MessageHeader) Encode() []byte {
buf := make([]byte, 16)
binary.LittleEndian.PutUint32(buf[0:4], h.ID)
// Pack opcode (high byte) and size (low 24 bits) into one uint32
// opcode in bits 24-31, size in bits 0-23
packed := (uint32(h.Opcode) << 24) | (h.Size & 0xFFFFFF)
binary.LittleEndian.PutUint32(buf[4:8], packed)
binary.LittleEndian.PutUint32(buf[8:12], h.HeaderSeq)
binary.LittleEndian.PutUint32(buf[12:16], h.NFds)
return buf
}
// DecodeHeader decodes 16 bytes into a message header
func DecodeHeader(data []byte) (*MessageHeader, error) {
if len(data) < 16 {
return nil, fmt.Errorf("insufficient data for header: need 16, got %d", len(data))
}
h := &MessageHeader{}
h.ID = binary.LittleEndian.Uint32(data[0:4])
// Extract opcode and size from the packed field
// opcode in bits 24-31, size in bits 0-23
packed := binary.LittleEndian.Uint32(data[4:8])
h.Opcode = uint8(packed >> 24)
h.Size = packed & 0xFFFFFF
h.HeaderSeq = binary.LittleEndian.Uint32(data[8:12])
h.NFds = binary.LittleEndian.Uint32(data[12:16])
return h, nil
}
// SendMessage sends a complete message (header + payload) using sendmsg
func SendMessage(fd int, header *MessageHeader, payload []byte) error {
headerBytes := header.Encode()
// Combine header and payload into a single buffer
msg := make([]byte, len(headerBytes)+len(payload))
copy(msg, headerBytes)
copy(msg[len(headerBytes):], payload)
// Use sendmsg like pw-cli does
err := syscall.Sendmsg(fd, msg, nil, nil, syscall.MSG_DONTWAIT|syscall.MSG_NOSIGNAL)
if err != nil {
return fmt.Errorf("failed to sendmsg: %w", err)
}
return nil
}
// Message represents a complete PipeWire message
type Message struct {
Header *MessageHeader
Payload []byte
}
// ReceiveMessages receives ALL messages from one recvmsg call
func ReceiveMessages(fd int) ([]*Message, error) {
// Allocate a large buffer like pw-cli does (98304 bytes to match what we saw in strace)
buf := make([]byte, 98304)
// Do a BLOCKING read - wait until data arrives
n, _, _, _, err := syscall.Recvmsg(fd, buf, nil, syscall.MSG_CMSG_CLOEXEC)
if err != nil {
return nil, fmt.Errorf("failed to recvmsg: %w", err)
}
// Parse all messages from the buffer
messages := make([]*Message, 0)
offset := 0
for offset < n {
if n-offset < 16 {
// Not enough data for a header
break
}
// Parse header
header, err := DecodeHeader(buf[offset : offset+16])
if err != nil {
return nil, fmt.Errorf("failed to decode header at offset %d: %w", offset, err)
}
// Check if we have the complete payload
messageSize := 16 + int(header.Size)
if offset+messageSize > n {
return nil, fmt.Errorf("incomplete message at offset %d: need %d bytes, have %d", offset, messageSize, n-offset)
}
// Extract payload
var payload []byte
if header.Size > 0 {
payload = make([]byte, header.Size)
copy(payload, buf[offset+16:offset+messageSize])
}
messages = append(messages, &Message{
Header: header,
Payload: payload,
})
offset += messageSize
}
return messages, nil
}
// SendCoreHello sends a Core::Hello message with version 3
func SendCoreHello(fd int, seq uint32) error {
// Create payload: Struct(Int: 3)
// According to protocol, version = 3
versionPod := NewInt(3)
structPod := NewStruct(versionPod)
payload := structPod.Encode()
header := &MessageHeader{
ID: 0, // Core object ID
Opcode: 1, // Core::Hello opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// ParseCoreInfo parses a Core::Info response
func ParseCoreInfo(payload []byte) error {
pod, _, err := DecodePOD(payload)
if err != nil {
return fmt.Errorf("failed to decode POD: %w", err)
}
if pod.Type != TypeStruct {
return fmt.Errorf("expected Struct, got type %d", pod.Type)
}
children, err := pod.GetStructChildren()
if err != nil {
return fmt.Errorf("failed to get struct children: %w", err)
}
fmt.Printf("Core::Info received with %d fields:\n", len(children))
// Parse the fields according to the protocol spec
// Struct(Int: id, Int: cookie, String: user_name, String: host_name,
// String: version, String: name, Long: change_mask, Struct: props)
if len(children) >= 1 {
id, err := children[0].GetInt()
if err == nil {
fmt.Printf(" id: %d\n", id)
}
}
if len(children) >= 2 {
cookie, err := children[1].GetInt()
if err == nil {
fmt.Printf(" cookie: %d\n", cookie)
}
}
if len(children) >= 3 {
userName, err := children[2].GetString()
if err == nil {
fmt.Printf(" user_name: %s\n", userName)
}
}
if len(children) >= 4 {
hostName, err := children[3].GetString()
if err == nil {
fmt.Printf(" host_name: %s\n", hostName)
}
}
if len(children) >= 5 {
version, err := children[4].GetString()
if err == nil {
fmt.Printf(" version: %s\n", version)
}
}
if len(children) >= 6 {
name, err := children[5].GetString()
if err == nil {
fmt.Printf(" name: %s\n", name)
}
}
if len(children) >= 7 {
changeMask, err := children[6].GetLong()
if err == nil {
fmt.Printf(" change_mask: %d\n", changeMask)
}
}
// Properties are in child 7 if change_mask has (1<<0)
if len(children) >= 8 {
fmt.Printf(" properties (struct with %d total children)\n", len(children))
}
return nil
}
// SendCoreGetRegistry sends Core::GetRegistry to bind to the registry
// Returns the new_id that will receive Registry events
func SendCoreGetRegistry(fd int, seq uint32, newID uint32) error {
// Create payload: Struct(Int: version, Int: new_id)
versionPod := NewInt(3) // Registry version 3
newIDPod := NewInt(int32(newID))
structPod := NewStruct(versionPod, newIDPod)
payload := structPod.Encode()
header := &MessageHeader{
ID: 0, // Core object ID
Opcode: 5, // Core::GetRegistry opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// SendCoreSync sends Core::Sync to mark a synchronization point
func SendCoreSync(fd int, id uint32, seq uint32) error {
// Create payload: Struct(Int: id, Int: seq)
idPod := NewInt(int32(id))
seqPod := NewInt(int32(seq))
structPod := NewStruct(idPod, seqPod)
payload := structPod.Encode()
header := &MessageHeader{
ID: 0, // Core object ID
Opcode: 2, // Core::Sync opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// SendClientUpdateProperties sends Client::UpdateProperties
func SendClientUpdateProperties(fd int, clientID uint32, seq uint32, props map[string]string) error {
// Create properties dict: Struct(Int: n_items, String: key1, String: val1, ...)
propFields := make([]*POD, 0)
propFields = append(propFields, NewInt(int32(len(props)))) // n_items
for key, val := range props {
propFields = append(propFields, NewString(key))
propFields = append(propFields, NewString(val))
}
propsStruct := NewStruct(propFields...)
outerStruct := NewStruct(propsStruct)
payload := outerStruct.Encode()
header := &MessageHeader{
ID: clientID, // Client object ID
Opcode: 2, // Client::UpdateProperties opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// SendCoreCreateObject sends Core::CreateObject to create a new object from a factory
func SendCoreCreateObject(fd int, seq uint32, factoryName string, typeName string, version uint32, props map[string]string, newID uint32) error {
// Create properties dict: Struct(Int: n_items, String: key1, String: val1, ...)
propFields := make([]*POD, 0)
propFields = append(propFields, NewInt(int32(len(props)))) // n_items
for key, val := range props {
propFields = append(propFields, NewString(key))
propFields = append(propFields, NewString(val))
}
propsStruct := NewStruct(propFields...)
// Create payload: Struct(String: factory_name, String: type, Int: version, Struct: props, Int: new_id)
payload := NewStruct(
NewString(factoryName),
NewString(typeName),
NewInt(int32(version)),
propsStruct,
NewInt(int32(newID)),
).Encode()
header := &MessageHeader{
ID: 0, // Core object ID
Opcode: 6, // Core::CreateObject opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// SendRegistryBind sends Registry::Bind to bind to a global object
func SendRegistryBind(fd int, registryID uint32, seq uint32, globalID uint32, typeName string, version uint32, newID uint32) error {
// Create payload: Struct(Int: id, String: type, Int: version, Int: new_id)
payload := NewStruct(
NewInt(int32(globalID)),
NewString(typeName),
NewInt(int32(version)),
NewInt(int32(newID)),
).Encode()
header := &MessageHeader{
ID: registryID, // Registry object ID
Opcode: 1, // Registry::Bind opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// SPA parameter type constants
const (
SPA_PARAM_Invalid = 0
SPA_PARAM_PropInfo = 1
SPA_PARAM_Props = 2
SPA_PARAM_EnumFormat = 3
SPA_PARAM_Format = 4
SPA_PARAM_Buffers = 5
SPA_PARAM_Meta = 6
SPA_PARAM_IO = 7
SPA_PARAM_EnumProfile = 8
SPA_PARAM_Profile = 9
SPA_PARAM_EnumPortConfig = 10
SPA_PARAM_PortConfig = 11
SPA_PARAM_EnumRoute = 12
SPA_PARAM_Route = 13
SPA_PARAM_Control = 14
SPA_PARAM_Latency = 15
SPA_PARAM_ProcessLatency = 16
)
// SendDeviceEnumParams sends Device::EnumParams to enumerate parameters
func SendDeviceEnumParams(fd int, deviceProxyID uint32, seq uint32, enumSeq uint32, paramID uint32) error {
// Create payload: Struct(Int: seq, Id: id, Int: index, Int: num, Pod: filter)
// filter is None (null) to get all params
payload := NewStruct(
NewInt(int32(enumSeq)), // seq for matching responses
NewId(paramID), // param type to enumerate
NewInt(0), // index: start at 0
NewInt(-1), // num: -1 means all
NewNone(), // filter: null/none
).Encode()
header := &MessageHeader{
ID: deviceProxyID, // Device proxy ID
Opcode: 2, // Device::EnumParams opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// SendDeviceSetParam sends Device::SetParam to set a parameter
func SendDeviceSetParam(fd int, deviceProxyID uint32, seq uint32, paramID uint32, paramPod *POD) error {
// Create payload: Struct(Id: id, Int: flags, Pod: param)
payload := NewStruct(
NewId(paramID), // param type (e.g. SPA_PARAM_Profile)
NewInt(0), // flags
paramPod, // the actual parameter POD
).Encode()
header := &MessageHeader{
ID: deviceProxyID, // Device proxy ID
Opcode: 3, // Device::SetParam opcode
Size: uint32(len(payload)),
HeaderSeq: seq,
NFds: 0,
}
return SendMessage(fd, header, payload)
}
// GlobalObject represents a global object from Registry::Global event
type GlobalObject struct {
ID uint32
Permissions uint32
Type string
Version uint32
Properties map[string]string
}
// ParseRegistryGlobalRemove parses a Registry::GlobalRemove event
func ParseRegistryGlobalRemove(payload []byte) (uint32, error) {
pod, _, err := DecodePOD(payload)
if err != nil {
return 0, fmt.Errorf("failed to decode POD: %w", err)
}
if pod.Type != TypeStruct {
return 0, fmt.Errorf("expected Struct, got type %d", pod.Type)
}
children, err := pod.GetStructChildren()
if err != nil {
return 0, fmt.Errorf("failed to get struct children: %w", err)
}
if len(children) < 1 {
return 0, fmt.Errorf("expected at least 1 field, got %d", len(children))
}
// Parse id (field 0)
id, err := children[0].GetInt()
if err != nil {
return 0, fmt.Errorf("failed to get id: %w", err)
}
return uint32(id), nil
}
// ParseRegistryGlobal parses a Registry::Global event
func ParseRegistryGlobal(payload []byte) (*GlobalObject, error) {
pod, _, err := DecodePOD(payload)
if err != nil {
return nil, fmt.Errorf("failed to decode POD: %w", err)
}
if pod.Type != TypeStruct {
return nil, fmt.Errorf("expected Struct, got type %d", pod.Type)
}
children, err := pod.GetStructChildren()
if err != nil {
return nil, fmt.Errorf("failed to get struct children: %w", err)
}
if len(children) < 5 {
return nil, fmt.Errorf("expected at least 5 fields, got %d", len(children))
}
obj := &GlobalObject{
Properties: make(map[string]string),
}
// Parse id (field 0)
id, err := children[0].GetInt()
if err != nil {
return nil, fmt.Errorf("failed to get id: %w", err)
}
obj.ID = uint32(id)
// Parse permissions (field 1)
permissions, err := children[1].GetInt()
if err != nil {
return nil, fmt.Errorf("failed to get permissions: %w", err)
}
obj.Permissions = uint32(permissions)
// Parse type (field 2)
objType, err := children[2].GetString()
if err != nil {
return nil, fmt.Errorf("failed to get type: %w", err)
}
obj.Type = objType
// Parse version (field 3)
version, err := children[3].GetInt()
if err != nil {
return nil, fmt.Errorf("failed to get version: %w", err)
}
obj.Version = uint32(version)
// Parse properties (field 4) - Struct with n_items followed by key-value pairs
if len(children) >= 5 && children[4].Type == TypeStruct {
propsChildren, err := children[4].GetStructChildren()
if err == nil && len(propsChildren) >= 1 {
// First field is n_items
// Following fields are key-value pairs
for i := 1; i+1 < len(propsChildren); i += 2 {
key, err1 := propsChildren[i].GetString()
value, err2 := propsChildren[i+1].GetString()
if err1 == nil && err2 == nil {
obj.Properties[key] = value
}
}
}
}
return obj, nil
}
// ParseCoreError parses a Core::Error event
func ParseCoreError(payload []byte) (uint32, int32, string, error) {
pod, _, err := DecodePOD(payload)
if err != nil {
return 0, 0, "", fmt.Errorf("failed to decode POD: %w", err)
}
if pod.Type != TypeStruct {
return 0, 0, "", fmt.Errorf("expected Struct, got type %d", pod.Type)
}
children, err := pod.GetStructChildren()
if err != nil {
return 0, 0, "", fmt.Errorf("failed to get struct children: %w", err)
}
if len(children) < 3 {
return 0, 0, "", fmt.Errorf("expected at least 3 fields, got %d", len(children))
}
// Parse id (field 0)
id, err := children[0].GetInt()
if err != nil {
return 0, 0, "", fmt.Errorf("failed to get id: %w", err)
}
// Parse seq (field 1) - not used, skip
// Parse res/error code (field 2)
res, err := children[2].GetInt()
if err != nil {
return 0, 0, "", fmt.Errorf("failed to get res: %w", err)
}
// Parse message (field 3)
var message string
if len(children) >= 4 {
message, _ = children[3].GetString()
}
return uint32(id), res, message, nil
}
// ParseCoreDone parses a Core::Done event
func ParseCoreDone(payload []byte) (uint32, uint32, error) {
pod, _, err := DecodePOD(payload)
if err != nil {
return 0, 0, fmt.Errorf("failed to decode POD: %w", err)
}
if pod.Type != TypeStruct {
return 0, 0, fmt.Errorf("expected Struct, got type %d", pod.Type)
}
children, err := pod.GetStructChildren()
if err != nil {
return 0, 0, fmt.Errorf("failed to get struct children: %w", err)
}
if len(children) < 2 {
return 0, 0, fmt.Errorf("expected at least 2 fields, got %d", len(children))
}
// Parse id (field 0)
id, err := children[0].GetInt()
if err != nil {
return 0, 0, fmt.Errorf("failed to get id: %w", err)
}
// Parse seq (field 1)
seq, err := children[1].GetInt()
if err != nil {
return 0, 0, fmt.Errorf("failed to get seq: %w", err)
}
return uint32(id), uint32(seq), nil
}
// DeviceInfo represents Device::Info event data
type DeviceInfo struct {
ID uint32
ChangeMask uint64
Properties map[string]string
}
// ParseDeviceInfo parses a Device::Info event
func ParseDeviceInfo(payload []byte) (*DeviceInfo, error) {
pod, _, err := DecodePOD(payload)
if err != nil {
return nil, fmt.Errorf("failed to decode POD: %w", err)
}
if pod.Type != TypeStruct {
return nil, fmt.Errorf("expected Struct, got type %d", pod.Type)
}
children, err := pod.GetStructChildren()
if err != nil {
return nil, fmt.Errorf("failed to get struct children: %w", err)
}
if len(children) < 2 {
return nil, fmt.Errorf("expected at least 2 fields, got %d", len(children))
}
info := &DeviceInfo{
Properties: make(map[string]string),
}
// Parse id (field 0)
id, err := children[0].GetInt()
if err != nil {
return nil, fmt.Errorf("failed to get id: %w", err)
}
info.ID = uint32(id)
// Parse change_mask (field 1) - Long type
changeMask, err := children[1].GetLong()
if err != nil {
return nil, fmt.Errorf("failed to get change_mask: %w", err)
}
info.ChangeMask = uint64(changeMask)
// Parse properties (field 2) - Struct with n_items followed by key-value pairs
if len(children) >= 3 && children[2].Type == TypeStruct {
propsChildren, err := children[2].GetStructChildren()
if err == nil && len(propsChildren) >= 1 {
// First field is n_items
// Following fields are key-value pairs
for i := 1; i+1 < len(propsChildren); i += 2 {
key, err1 := propsChildren[i].GetString()
value, err2 := propsChildren[i+1].GetString()
if err1 == nil && err2 == nil {
info.Properties[key] = value
}
}
}
}
return info, nil
}
// Removed async Connection/PendingRequest complexity - using simple synchronous approach
// ConnectToPipeWire connects to the PipeWire socket and returns the file descriptor
func ConnectToPipeWire() (int, error) {
// Try to find the socket
runtimeDir := os.Getenv("XDG_RUNTIME_DIR")
if runtimeDir == "" {
runtimeDir = os.Getenv("PIPEWIRE_RUNTIME_DIR")
}
if runtimeDir == "" {
return -1, fmt.Errorf("neither XDG_RUNTIME_DIR nor PIPEWIRE_RUNTIME_DIR is set")
}
socketPath := filepath.Join(runtimeDir, "pipewire-0")
fmt.Printf("Connecting to PipeWire socket: %s\n", socketPath)
// Create socket with SOCK_CLOEXEC (blocking for simpler code)
fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_STREAM|syscall.SOCK_CLOEXEC, 0)
if err != nil {
return -1, fmt.Errorf("failed to create socket: %w", err)
}
// Connect to the socket
addr := &syscall.SockaddrUnix{Name: socketPath}
err = syscall.Connect(fd, addr)
if err != nil {
syscall.Close(fd)
return -1, fmt.Errorf("failed to connect to socket: %w", err)
}
return fd, nil
}
func main() {
// Check for subcommands
if len(os.Args) >= 2 && os.Args[1] == "trace" {
if err := TraceCommand(os.Args[2:]); err != nil {
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
os.Exit(1)
}
return
}
fmt.Println("PipeWire Device Lister")
fmt.Println("======================")
// Connect to PipeWire
fd, err := ConnectToPipeWire()
if err != nil {
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
os.Exit(1)
}
defer syscall.Close(fd)
fmt.Println("Connected successfully!")
var headerSeq uint32 = 0 // Track message sequence
const registryID uint32 = 1
const clientID uint32 = 1 // Client will be assigned ID 1
// Track next available client-side proxy ID
// Start at 2 (0=core, 1=registry, client uses separate ID space)
nextProxyID := uint32(2)
// Send Core::Hello
fmt.Println("\nSending Core::Hello (version=3)...")
err = SendCoreHello(fd, headerSeq)
if err != nil {
fmt.Fprintf(os.Stderr, "Error sending hello: %v\n", err)
os.Exit(1)
}
headerSeq++
// Send Client::UpdateProperties with minimal properties
fmt.Println("Sending Client::UpdateProperties...")
props := map[string]string{
"application.name": "pw-sesh",
"application.process.binary": "pw-sesh",
}
err = SendClientUpdateProperties(fd, clientID, headerSeq, props)
if err != nil {
fmt.Fprintf(os.Stderr, "Error sending UpdateProperties: %v\n", err)
os.Exit(1)
}
headerSeq++
// Send Core::GetRegistry
fmt.Printf("Sending Core::GetRegistry (new_id=%d)...\n", registryID)
err = SendCoreGetRegistry(fd, headerSeq, registryID)
if err != nil {
fmt.Fprintf(os.Stderr, "Error sending GetRegistry: %v\n", err)
os.Exit(1)
}
headerSeq++
// Send Core::Sync
syncSeq := uint32(12345) // Arbitrary sync sequence number
fmt.Printf("Sending Core::Sync (seq=%d)...\n", syncSeq)
err = SendCoreSync(fd, 0, syncSeq)
if err != nil {
fmt.Fprintf(os.Stderr, "Error sending sync: %v\n", err)
os.Exit(1)
}
headerSeq++
// Read messages until we get Core::Done with our syncSeq
fmt.Println("\nWaiting for registry globals...")
allMessages := make([]*Message, 0)
for {
messages, err := ReceiveMessages(fd)
if err != nil {
fmt.Fprintf(os.Stderr, "Error receiving messages: %v\n", err)
os.Exit(1)
}
for _, msg := range messages {
allMessages = append(allMessages, msg)
// Check if this is Core::Done with our sync seq
if msg.Header.ID == 0 && msg.Header.Opcode == 1 {
_, doneSeq, err := ParseCoreDone(msg.Payload)
if err != nil {
fmt.Fprintf(os.Stderr, "Error parsing Core::Done: %v\n", err)
continue
}
if doneSeq == syncSeq {
// Done! We've received all registry globals
goto done
}
}
}
}
done:
fmt.Printf("\nā Received %d total messages\n", len(allMessages))
// Parse globals from messages
globals := make(map[uint32]*GlobalObject)
for _, msg := range allMessages {
if msg.Header.ID == registryID {
if msg.Header.Opcode == 0 {
// Registry::Global event
obj, err := ParseRegistryGlobal(msg.Payload)
if err != nil {
fmt.Fprintf(os.Stderr, "Error parsing Registry::Global: %v\n", err)
continue
}
globals[obj.ID] = obj
} else if msg.Header.Opcode == 1 {
// Registry::GlobalRemove event
id, err := ParseRegistryGlobalRemove(msg.Payload)
if err != nil {
fmt.Fprintf(os.Stderr, "Error parsing Registry::GlobalRemove: %v\n", err)
continue
}
// Remove from our map
delete(globals, id)
fmt.Printf(" (Global ID %d was removed)\n", id)
}
}
}
// Filter and display devices
fmt.Println("\n======================")
fmt.Printf("Found %d global objects\n", len(globals))
fmt.Println("======================")
devices := make([]*GlobalObject, 0)
for _, obj := range globals {
if obj.Type == "PipeWire:Interface:Device" {
devices = append(devices, obj)
}
}
fmt.Printf("\nDevices (%d):\n", len(devices))
fmt.Println("-------------")
for _, dev := range devices {
fmt.Printf("\nDevice ID %d:\n", dev.ID)
fmt.Printf(" Type: %s\n", dev.Type)
fmt.Printf(" Version: %d\n", dev.Version)
// Show interesting properties
if name, ok := dev.Properties["device.description"]; ok {
fmt.Printf(" Description: %s\n", name)
}
if name, ok := dev.Properties["device.name"]; ok {
fmt.Printf(" Name: %s\n", name)
}
if api, ok := dev.Properties["device.api"]; ok {
fmt.Printf(" API: %s\n", api)
}
if class, ok := dev.Properties["media.class"]; ok {
fmt.Printf(" Class: %s\n", class)
}
}
fmt.Println("\nā Successfully listed all devices!")
// Skip BlueZ monitor for now - focus on ALSA
// Now create an ALSA monitor to see real audio devices
fmt.Println("\n======================")
fmt.Println("Creating ALSA Monitor")
fmt.Println("======================")
alsaMonitorID := nextProxyID
nextProxyID++
alsaProps := map[string]string{
"factory.name": "api.alsa.enum.udev",
}
fmt.Printf("\nSending Core::CreateObject for ALSA monitor (ID=%d)...\n", alsaMonitorID)
err = SendCoreCreateObject(fd, headerSeq, "spa-device-factory", "PipeWire:Interface:Device", 3, alsaProps, alsaMonitorID)
if err != nil {
fmt.Fprintf(os.Stderr, "Error creating ALSA monitor: %v\n", err)
os.Exit(1)
}
headerSeq++
// Read ALSA monitor creation response and keep reading for a bit
fmt.Println("\nWaiting for ALSA monitor creation and device discovery...")
// Set socket to non-blocking for subsequent reads
err = syscall.SetNonblock(fd, true)
if err != nil {
fmt.Fprintf(os.Stderr, "Error setting non-blocking: %v\n", err)
os.Exit(1)
}
// Keep reading messages with a poll timeout - wait longer for nodes to appear
allDeviceMessages := make([]*Message, 0)
timeoutCount := 0
for i := range 30 { // Try up to 30 poll cycles
// Poll with 1000ms timeout
pollFds := []unix.PollFd{
{Fd: int32(fd), Events: unix.POLLIN},
}
n, err := unix.Poll(pollFds, 1000) // 1000ms timeout
if err != nil {
fmt.Fprintf(os.Stderr, "Error polling: %v\n", err)
break
}
if n == 0 {
// Timeout - no more messages
timeoutCount++
fmt.Printf(" Poll timeout %d/3...\n", timeoutCount)
if timeoutCount >= 3 {
// After 3 consecutive timeouts (3s of inactivity), assume we're done
fmt.Printf("Poll timeout after %d batches (no activity for 3s)\n", i-2)
break
}
continue
}
timeoutCount = 0 // Reset on successful read
// Data available, read it
messages, err := ReceiveMessages(fd)
if err != nil {
// EAGAIN is expected with non-blocking socket
if err.Error() == "failed to recvmsg: resource temporarily unavailable" {
break
}
fmt.Fprintf(os.Stderr, "Error receiving response: %v\n", err)
break
}
allDeviceMessages = append(allDeviceMessages, messages...)
fmt.Printf("Batch %d: Received %d messages\n", i+1, len(messages))
}
fmt.Printf("\nTotal messages received: %d\n", len(allDeviceMessages))
// Collect discovered objects
discoveredDevices := make([]*GlobalObject, 0)
discoveredNodes := make([]*GlobalObject, 0)
fmt.Println("\nAll messages received:")
for i, msg := range allDeviceMessages {
fmt.Printf("%d. ID=%d, Opcode=%d, Size=%d\n", i+1, msg.Header.ID, msg.Header.Opcode, msg.Header.Size)
if msg.Header.ID == registryID {
if msg.Header.Opcode == 0 {
obj, _ := ParseRegistryGlobal(msg.Payload)
if obj != nil {
fmt.Printf(" -> Registry::Global: %s (global_id=%d)\n", obj.Type, obj.ID)
}
} else if msg.Header.Opcode == 1 {
id, _ := ParseRegistryGlobalRemove(msg.Payload)
fmt.Printf(" -> Registry::GlobalRemove: global_id=%d\n", id)
}
} else if msg.Header.ID == alsaMonitorID {
fmt.Printf(" -> Message for ALSA monitor proxy\n")
} else if msg.Header.ID == 0 {
if msg.Header.Opcode == 3 {
id, code, errMsg, _ := ParseCoreError(msg.Payload)
fmt.Printf(" -> Core::Error for object %d: code=%d, msg=%q\n", id, code, errMsg)
} else if msg.Header.Opcode == 5 {
fmt.Printf(" -> Core::BoundId\n")
}
}
}
fmt.Println("\nDiscovered objects:")
for _, msg := range allDeviceMessages {
if msg.Header.ID == registryID {
if msg.Header.Opcode == 0 {
// Registry::Global
obj, err := ParseRegistryGlobal(msg.Payload)
if err != nil {
continue
}
// Collect audio devices
if obj.Type == "PipeWire:Interface:Device" && obj.Properties["device.api"] == "alsa:pcm" {
discoveredDevices = append(discoveredDevices, obj)
fmt.Printf(" Device ID=%d: %s (media.class=%s)\n",
obj.ID, obj.Properties["object.path"], obj.Properties["media.class"])
}
// Collect nodes
if obj.Type == "PipeWire:Interface:Node" {
discoveredNodes = append(discoveredNodes, obj)
fmt.Printf(" Node ID=%d: %s (%s)\n",
obj.ID, obj.Properties["node.name"], obj.Properties["media.class"])
}
}
}
}
if len(discoveredDevices) == 0 {
fmt.Println("No audio devices discovered!")
}
if len(discoveredNodes) > 0 {
fmt.Printf("\nFound %d nodes!\n", len(discoveredNodes))
fmt.Println("\nā Devices are creating nodes automatically!")
fmt.Println("\nā Done!")
return
}
if len(discoveredDevices) > 0 {
fmt.Println("\nNo nodes appeared yet - let's try binding to a device")
// Bind to the first device
fmt.Println("\n======================")
fmt.Println("Binding to First Device")
fmt.Println("======================")
firstDevice := discoveredDevices[0]
deviceProxyID := nextProxyID
nextProxyID++
fmt.Printf("\nBinding to device global_id=%d (%s) with proxy_id=%d...\n",
firstDevice.ID, firstDevice.Properties["object.path"], deviceProxyID)
err = SendRegistryBind(fd, registryID, headerSeq, firstDevice.ID, "PipeWire:Interface:Device", 3, deviceProxyID)
if err != nil {
fmt.Fprintf(os.Stderr, "Error binding to device: %v\n", err)
os.Exit(1)
}
headerSeq++
// Read messages after binding
fmt.Println("\nWaiting for device binding response...")
timeoutCount = 0
boundDeviceMessages := make([]*Message, 0)
for i := range 10 {
pollFds := []unix.PollFd{
{Fd: int32(fd), Events: unix.POLLIN},
}
n, err := unix.Poll(pollFds, 1000)
if err != nil {
fmt.Fprintf(os.Stderr, "Error polling: %v\n", err)
break
}
if n == 0 {
timeoutCount++
if timeoutCount >= 2 {
fmt.Printf("Poll timeout after %d batches\n", i-1)
break
}
continue
}
timeoutCount = 0
messages, err := ReceiveMessages(fd)
if err != nil {
if err.Error() == "failed to recvmsg: resource temporarily unavailable" {
break
}
fmt.Fprintf(os.Stderr, "Error receiving response: %v\n", err)
break
}
boundDeviceMessages = append(boundDeviceMessages, messages...)
fmt.Printf("Batch %d: Received %d messages\n", i+1, len(messages))
}
fmt.Printf("\nā Successfully bound to device!\n")
// Now enumerate available profiles
fmt.Println("\n======================")
fmt.Println("Enumerating Device Profiles")
fmt.Println("======================")
enumSeq := uint32(54321) // Arbitrary sequence number to match responses
fmt.Printf("\nSending Device::EnumParams for profiles (seq=%d)...\n", enumSeq)
err = SendDeviceEnumParams(fd, deviceProxyID, headerSeq, enumSeq, SPA_PARAM_EnumProfile)
if err != nil {
fmt.Fprintf(os.Stderr, "Error enumerating params: %v\n", err)
os.Exit(1)
}
headerSeq++
// Read Device::Param responses
fmt.Println("\nWaiting for profile enumeration...")
timeoutCount = 0
paramMessages := make([]*Message, 0)
for i := range 10 {
pollFds := []unix.PollFd{
{Fd: int32(fd), Events: unix.POLLIN},
}
n, err := unix.Poll(pollFds, 1000)
if err != nil {
fmt.Fprintf(os.Stderr, "Error polling: %v\n", err)
break
}
if n == 0 {
timeoutCount++
if timeoutCount >= 2 {
fmt.Printf("Poll timeout after %d batches\n", i-1)
break
}
continue
}
timeoutCount = 0
messages, err := ReceiveMessages(fd)
if err != nil {
if err.Error() == "failed to recvmsg: resource temporarily unavailable" {
break
}
fmt.Fprintf(os.Stderr, "Error receiving response: %v\n", err)
break
}
paramMessages = append(paramMessages, messages...)
fmt.Printf("Batch %d: Received %d messages\n", i+1, len(messages))
}
fmt.Printf("\nReceived %d profile messages:\n", len(paramMessages))
for i, msg := range paramMessages {
if msg.Header.ID == deviceProxyID && msg.Header.Opcode == 1 {
// Device::Param - contains profile data
pod, _, err := DecodePOD(msg.Payload)
if err != nil {
continue
}
children, _ := pod.GetStructChildren()
if len(children) >= 5 {
profilePod := children[4]
fmt.Printf("\nProfile %d:\n", i+1)
fmt.Println(profilePod.PrettyPrint(2))
}
}
}
// Now set the "on" profile (index 1)
fmt.Println("\n======================")
fmt.Println("Setting Profile to 'on'")
fmt.Println("======================")
// Create a Profile parameter object with index=1
// Object format: Object(type=262151, id=8) with key=1 (SPA_PARAM_PROFILE_index) => Int(1)
// We need to create: Object with properties
// For simplicity, let's just create an Object with index property
// Build the profile parameter POD
// Object structure: [object_type:4][object_id:4][key:4][flags:4][value_pod]
profileData := make([]byte, 0)
// object_type (262151 = ParamProfile type)
objType := make([]byte, 4)
binary.LittleEndian.PutUint32(objType, 262151)
profileData = append(profileData, objType...)
// object_id (8 = Profile)
objID := make([]byte, 4)
binary.LittleEndian.PutUint32(objID, 8)
profileData = append(profileData, objID...)
// Property: key=1 (index), flags=0, value=Int(1)
key := make([]byte, 4)
binary.LittleEndian.PutUint32(key, 1) // SPA_PARAM_PROFILE_index
profileData = append(profileData, key...)
flags := make([]byte, 4)
binary.LittleEndian.PutUint32(flags, 0)
profileData = append(profileData, flags...)
// Value: Int(1) for "on" profile
indexPod := NewInt(1)
profileData = append(profileData, indexPod.Encode()...)
// Pad to 8-byte alignment
for len(profileData)%8 != 0 {
profileData = append(profileData, 0)
}
// Create the Object POD
profilePod := &POD{
Size: uint32(len(profileData)),
Type: TypeObject,
Data: profileData,
}
fmt.Printf("\nSending Device::SetParam with profile:\n")
fmt.Println(profilePod.PrettyPrint(2))
err = SendDeviceSetParam(fd, deviceProxyID, headerSeq, SPA_PARAM_Profile, profilePod)
if err != nil {
fmt.Fprintf(os.Stderr, "Error setting profile: %v\n", err)
os.Exit(1)
}
headerSeq++
// Read messages to see if nodes get created
fmt.Println("\nWaiting for nodes to be created...")
timeoutCount = 0
nodeMessages := make([]*Message, 0)
for i := range 20 {
pollFds := []unix.PollFd{
{Fd: int32(fd), Events: unix.POLLIN},
}
n, err := unix.Poll(pollFds, 1000)
if err != nil {
fmt.Fprintf(os.Stderr, "Error polling: %v\n", err)
break
}
if n == 0 {
timeoutCount++
if timeoutCount >= 3 {
fmt.Printf("Poll timeout after %d batches\n", i-2)
break
}
continue
}
timeoutCount = 0
messages, err := ReceiveMessages(fd)
if err != nil {
if err.Error() == "failed to recvmsg: resource temporarily unavailable" {
break
}
fmt.Fprintf(os.Stderr, "Error receiving response: %v\n", err)
break
}
nodeMessages = append(nodeMessages, messages...)
fmt.Printf("Batch %d: Received %d messages\n", i+1, len(messages))
}
fmt.Printf("\nReceived %d messages after setting profile:\n", len(nodeMessages))
createdNodes := make([]*GlobalObject, 0)
for _, msg := range nodeMessages {
if msg.Header.ID == registryID && msg.Header.Opcode == 0 {
// Registry::Global - check for nodes
obj, err := ParseRegistryGlobal(msg.Payload)
if err == nil && obj.Type == "PipeWire:Interface:Node" {
createdNodes = append(createdNodes, obj)
fmt.Printf("\nā Node created! Global ID: %d\n", obj.ID)
if nodeName, ok := obj.Properties["node.name"]; ok {
fmt.Printf(" node.name: %s\n", nodeName)
}
if mediaClass, ok := obj.Properties["media.class"]; ok {
fmt.Printf(" media.class: %s\n", mediaClass)
}
}
}
}
if len(createdNodes) > 0 {
fmt.Printf("\nš SUCCESS! Created %d audio nodes!\n", len(createdNodes))
// Now bind to the first node to get full details
fmt.Println("\n======================")
fmt.Println("Binding to First Node")
fmt.Println("======================")
firstNode := createdNodes[0]
nodeProxyID := nextProxyID
nextProxyID++
fmt.Printf("\nBinding to node global_id=%d (%s) with proxy_id=%d...\n",
firstNode.ID, firstNode.Properties["node.name"], nodeProxyID)
err = SendRegistryBind(fd, registryID, headerSeq, firstNode.ID, "PipeWire:Interface:Node", 3, nodeProxyID)
if err != nil {
fmt.Fprintf(os.Stderr, "Error binding to node: %v\n", err)
os.Exit(1)
}
headerSeq++
// Read node info
fmt.Println("\nWaiting for node info...")
timeoutCount = 0
nodeInfoMessages := make([]*Message, 0)
for i := range 10 {
pollFds := []unix.PollFd{
{Fd: int32(fd), Events: unix.POLLIN},
}
n, err := unix.Poll(pollFds, 1000)
if err != nil {
fmt.Fprintf(os.Stderr, "Error polling: %v\n", err)
break
}
if n == 0 {
timeoutCount++
if timeoutCount >= 2 {
fmt.Printf("Poll timeout after %d batches\n", i-1)
break
}
continue
}
timeoutCount = 0
messages, err := ReceiveMessages(fd)
if err != nil {
if err.Error() == "failed to recvmsg: resource temporarily unavailable" {
break
}
fmt.Fprintf(os.Stderr, "Error receiving response: %v\n", err)
break
}
nodeInfoMessages = append(nodeInfoMessages, messages...)
fmt.Printf("Batch %d: Received %d messages\n", i+1, len(messages))
}
fmt.Printf("\n======================")
fmt.Printf("\nNode Information")
fmt.Printf("\n======================\n")
for _, msg := range nodeInfoMessages {
if msg.Header.ID == 0 && msg.Header.Opcode == 5 {
fmt.Println("\nā Core::BoundId (binding confirmed)")
} else if msg.Header.ID == nodeProxyID && msg.Header.Opcode == 0 {
// Node::Info - parse the structure
pod, _, err := DecodePOD(msg.Payload)
if err != nil {
fmt.Printf("Failed to decode: %v\n", err)
continue
}
children, err := pod.GetStructChildren()
if err != nil || len(children) < 9 {
fmt.Printf("Failed to parse node info struct\n")
continue
}
// Node::Info structure:
// [0]: id (Int)
// [1]: max_input_ports (Int)
// [2]: max_output_ports (Int)
// [3]: change_mask (Long)
// [4]: n_input_ports (Int)
// [5]: n_output_ports (Int)
// [6]: state (Id)
// [7]: error (String or None)
// [8]: props (Struct with key-value pairs)
// [9]: param_info (Struct)
nodeID, _ := children[0].GetInt()
maxInput, _ := children[1].GetInt()
maxOutput, _ := children[2].GetInt()
changeMask, _ := children[3].GetLong()
nInput, _ := children[4].GetInt()
nOutput, _ := children[5].GetInt()
fmt.Println("\nā Node::Info received!")
fmt.Printf("\n Node ID: %d\n", nodeID)
fmt.Printf(" Ports: %d input (max %d), %d output (max %d)\n",
nInput, maxInput, nOutput, maxOutput)
fmt.Printf(" Change Mask: 0x%x\n", changeMask)
// Parse properties (field 8)
if len(children) > 8 && children[8].Type == TypeStruct {
propChildren, err := children[8].GetStructChildren()
if err == nil && len(propChildren) > 0 {
// First field is n_items
nItems, _ := propChildren[0].GetInt()
fmt.Printf("\n Properties (%d items):\n", nItems)
// Following fields are key-value pairs
for i := 1; i+1 < len(propChildren); i += 2 {
key, err1 := propChildren[i].GetString()
value, err2 := propChildren[i+1].GetString()
if err1 == nil && err2 == nil {
// Only show interesting properties
if key == "node.name" || key == "node.description" ||
key == "media.class" || key == "device.id" ||
key == "api.alsa.pcm.name" || key == "api.alsa.path" ||
key == "object.path" || key == "object.id" {
fmt.Printf(" %-20s = %s\n", key, value)
}
}
}
fmt.Println("\n All properties:")
for i := 1; i+1 < len(propChildren); i += 2 {
key, err1 := propChildren[i].GetString()
value, err2 := propChildren[i+1].GetString()
if err1 == nil && err2 == nil {
fmt.Printf(" %-30s = %s\n", key, value)
}
}
}
}
// Parse param_info (field 9) - shows what parameters this node supports
if len(children) > 9 && children[9].Type == TypeStruct {
paramChildren, err := children[9].GetStructChildren()
if err == nil && len(paramChildren) > 1 {
nParams, _ := paramChildren[0].GetInt()
fmt.Printf("\n Supported Parameters (%d):\n", nParams)
// param_info is: Int: n_items, (Id: param_id, Int: flags)*
for i := 1; i+1 < len(paramChildren); i += 2 {
// param_id is an Id type
if len(paramChildren[i].Data) >= 4 {
paramID := binary.LittleEndian.Uint32(paramChildren[i].Data[0:4])
flags, _ := paramChildren[i+1].GetInt()
paramName := "Unknown"
switch paramID {
case SPA_PARAM_EnumFormat:
paramName = "EnumFormat"
case SPA_PARAM_Format:
paramName = "Format"
case SPA_PARAM_Props:
paramName = "Props"
case SPA_PARAM_EnumProfile:
paramName = "EnumProfile"
case SPA_PARAM_Profile:
paramName = "Profile"
case SPA_PARAM_Latency:
paramName = "Latency"
}
fmt.Printf(" [%d] %s (flags=0x%x)\n", paramID, paramName, flags)
}
}
}
}
}
}
} else {
fmt.Println("\nā No nodes were created")
}
// Keep the connection alive so devices/nodes persist
fmt.Println("\n======================")
fmt.Println("Session Manager Running")
fmt.Println("======================")
fmt.Println("\nPress Ctrl+C to exit and cleanup devices...")
fmt.Println("Or put this process in the background with Ctrl+Z, then 'bg'")
// Keep reading messages in case of events
for {
pollFds := []unix.PollFd{
{Fd: int32(fd), Events: unix.POLLIN},
}
n, err := unix.Poll(pollFds, 5000) // 5 second timeout
if err != nil {
fmt.Fprintf(os.Stderr, "\nError polling: %v\n", err)
break
}
if n > 0 {
messages, err := ReceiveMessages(fd)
if err != nil {
fmt.Fprintf(os.Stderr, "\nError receiving: %v\n", err)
break
}
// Print any interesting events
for _, msg := range messages {
if msg.Header.ID == registryID {
if msg.Header.Opcode == 0 {
obj, _ := ParseRegistryGlobal(msg.Payload)
if obj != nil {
fmt.Printf("[Event] New global: %s (ID=%d)\n", obj.Type, obj.ID)
}
} else if msg.Header.Opcode == 1 {
id, _ := ParseRegistryGlobalRemove(msg.Payload)
fmt.Printf("[Event] Global removed: ID=%d\n", id)
}
}
}
}
}
} else {
fmt.Println("\nNo devices discovered to bind to")
}
fmt.Println("\nā Done!")
}
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