Add call protocol, Rmux. Update AmneziaWG. Fixes and improvements

transport/call/vk/screen_datachannels.go

@@ -0,0 +1,101 @@
+package vk
+
+import (
+	"errors"
+	"io"
+	"sync"
+
+	"github.com/pion/datachannel"
+	"github.com/pion/webrtc/v4"
+	"github.com/sagernet/sing/common/logger"
+)
+
+var errScreenNotReady = errors.New("screen DC not ready")
+
+type screenUplink struct {
+	mu  sync.Mutex
+	raw io.WriteCloser
+}
+
+func (u *screenUplink) attach(raw io.WriteCloser) {
+	u.mu.Lock()
+	u.raw = raw
+	u.mu.Unlock()
+}
+
+func (u *screenUplink) ready() bool {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	return u.raw != nil
+}
+
+func (u *screenUplink) send(b []byte) error {
+	u.mu.Lock()
+	raw := u.raw
+	u.mu.Unlock()
+	if raw == nil {
+		return errScreenNotReady
+	}
+	_, err := raw.Write(b)
+	if err != nil {
+		u.mu.Lock()
+		if u.raw == raw {
+			u.raw = nil
+		}
+		u.mu.Unlock()
+	}
+	return err
+}
+
+func (u *screenUplink) reset() {
+	u.mu.Lock()
+	if u.raw != nil {
+		u.raw.Close()
+		u.raw = nil
+	}
+	u.mu.Unlock()
+}
+
+func readScreenDataChannel(dc *webrtc.DataChannel, handler func([]byte), logger logger.ContextLogger) {
+	dc.OnOpen(func() {
+		var raw datachannel.ReadWriteCloser
+		raw, err := dc.Detach()
+		if err != nil {
+			logger.Warn("[vk-joiner] screen DC detach failed, using OnMessage")
+			dc.OnMessage(func(m webrtc.DataChannelMessage) {
+				if !m.IsString && len(m.Data) > 0 {
+					frame := make([]byte, len(m.Data))
+					copy(frame, m.Data)
+					handler(frame)
+				}
+			})
+			return
+		}
+		logger.Debug("[vk-joiner] screen DC attached for reading")
+		buf := make([]byte, 65536)
+		for {
+			n, isString, rerr := raw.ReadDataChannel(buf)
+			if rerr != nil {
+				return
+			}
+			if isString || n == 0 {
+				continue
+			}
+			frame := make([]byte, n)
+			copy(frame, buf[:n])
+			handler(frame)
+		}
+	})
+}
+
+func attachScreenWriterDC(dc *webrtc.DataChannel, onRaw func(io.WriteCloser), logger logger.ContextLogger) {
+	dc.OnOpen(func() {
+		raw, err := dc.Detach()
+		if err != nil {
+			logger.Warn("[vk-joiner] screen writer DC detach failed")
+			return
+		}
+		logger.Debug("[vk-joiner] screen DC attached for writing")
+		onRaw(raw)
+	})
+}