Files
netris-nestri/packages/relay/internal/common/common.go
2025-11-29 19:05:20 +02:00

116 lines
3.3 KiB
Go

package common
import (
"fmt"
"log/slog"
"strconv"
"github.com/libp2p/go-reuseport"
"github.com/pion/ice/v4"
"github.com/pion/interceptor"
"github.com/pion/webrtc/v4"
)
var globalWebRTCAPI *webrtc.API
var globalWebRTCConfig = webrtc.Configuration{
ICETransportPolicy: webrtc.ICETransportPolicyAll,
BundlePolicy: webrtc.BundlePolicyBalanced,
SDPSemantics: webrtc.SDPSemanticsUnifiedPlan,
}
func InitWebRTCAPI() error {
var err error
flags := GetFlags()
// Media engine
mediaEngine := &webrtc.MediaEngine{}
// Register our extensions
if err = RegisterExtensions(mediaEngine); err != nil {
return fmt.Errorf("failed to register extensions: %w", err)
}
// Default codecs cover our needs
err = mediaEngine.RegisterDefaultCodecs()
if err != nil {
return err
}
// Interceptor registry
interceptorRegistry := &interceptor.Registry{}
// Use default set
err = webrtc.RegisterDefaultInterceptors(mediaEngine, interceptorRegistry)
if err != nil {
return err
}
// Setting engine
settingEngine := webrtc.SettingEngine{}
// New in v4, reduces CPU usage and latency when enabled
settingEngine.EnableSCTPZeroChecksum(true)
nat11IP := GetFlags().NAT11IP
if len(nat11IP) > 0 {
settingEngine.SetNAT1To1IPs([]string{nat11IP}, webrtc.ICECandidateTypeHost)
slog.Info("Using NAT 1:1 IP for WebRTC", "nat11_ip", nat11IP)
}
muxPort := GetFlags().UDPMuxPort
if muxPort > 0 {
// Use reuseport to allow multiple listeners on the same port
pktListener, err := reuseport.ListenPacket("udp", ":"+strconv.Itoa(muxPort))
if err != nil {
return fmt.Errorf("failed to create WebRTC muxed UDP listener: %w", err)
}
mux := ice.NewMultiUDPMuxDefault(ice.NewUDPMuxDefault(ice.UDPMuxParams{
UDPConn: pktListener,
}))
slog.Info("Using UDP Mux for WebRTC", "port", muxPort)
settingEngine.SetICEUDPMux(mux)
}
if flags.WebRTCUDPStart > 0 && flags.WebRTCUDPEnd > 0 && flags.WebRTCUDPStart < flags.WebRTCUDPEnd {
// Set the UDP port range used by WebRTC
err = settingEngine.SetEphemeralUDPPortRange(uint16(flags.WebRTCUDPStart), uint16(flags.WebRTCUDPEnd))
if err != nil {
return err
}
slog.Info("Using WebRTC UDP Port Range", "start", flags.WebRTCUDPStart, "end", flags.WebRTCUDPEnd)
}
// Improves speed when sending offers to browsers (https://github.com/pion/webrtc/issues/3174)
settingEngine.SetIncludeLoopbackCandidate(true)
// Create a new API object with our customized settings
globalWebRTCAPI = webrtc.NewAPI(webrtc.WithMediaEngine(mediaEngine), webrtc.WithSettingEngine(settingEngine), webrtc.WithInterceptorRegistry(interceptorRegistry))
return nil
}
// CreatePeerConnection sets up a new peer connection
func CreatePeerConnection(onClose func()) (*webrtc.PeerConnection, error) {
pc, err := globalWebRTCAPI.NewPeerConnection(globalWebRTCConfig)
if err != nil {
return nil, err
}
// Log connection state changes and handle failed/disconnected connections
pc.OnConnectionStateChange(func(connectionState webrtc.PeerConnectionState) {
// Close PeerConnection in cases
if connectionState == webrtc.PeerConnectionStateFailed ||
connectionState == webrtc.PeerConnectionStateDisconnected ||
connectionState == webrtc.PeerConnectionStateClosed {
err = pc.Close()
if err != nil {
slog.Error("Failed to close PeerConnection", "err", err)
}
onClose()
}
})
return pc, nil
}