add RTSP-over-WebSocket (#891) (#898)

client_tunnel_websocket.go

@@ -0,0 +1,81 @@
+package gortsplib
+
+import (
+	"context"
+	"crypto/tls"
+	"io"
+	"net"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+type clientTunnelWebSocket struct {
+	wconn *websocket.Conn
+	r     io.Reader
+	w     io.Writer
+}
+
+func (tu *clientTunnelWebSocket) Read(b []byte) (int, error) {
+	return tu.r.Read(b)
+}
+
+func (tu *clientTunnelWebSocket) Write(b []byte) (int, error) {
+	return tu.w.Write(b)
+}
+
+func (tu *clientTunnelWebSocket) Close() error {
+	return tu.wconn.Close()
+}
+
+func (tu *clientTunnelWebSocket) LocalAddr() net.Addr {
+	return tu.wconn.LocalAddr()
+}
+
+func (tu *clientTunnelWebSocket) RemoteAddr() net.Addr {
+	return tu.wconn.RemoteAddr()
+}
+
+func (tu *clientTunnelWebSocket) SetDeadline(_ time.Time) error {
+	return nil
+}
+
+func (tu *clientTunnelWebSocket) SetReadDeadline(t time.Time) error {
+	return tu.wconn.SetReadDeadline(t)
+}
+
+func (tu *clientTunnelWebSocket) SetWriteDeadline(t time.Time) error {
+	return tu.wconn.SetWriteDeadline(t)
+}
+
+func newClientTunnelWebSocket(
+	ctx context.Context,
+	dialContext func(ctx context.Context, network, address string) (net.Conn, error),
+	addr string,
+	tlsConfig *tls.Config,
+) (net.Conn, error) {
+	c := &clientTunnelWebSocket{}
+
+	var ur string
+	if tlsConfig != nil {
+		ur = "wss"
+	} else {
+		ur = "ws"
+	}
+	ur += "://" + addr + "/"
+
+	var err error
+	c.wconn, _, err = (&websocket.Dialer{
+		NetDialContext:  dialContext,
+		TLSClientConfig: tlsConfig,
+		Subprotocols:    []string{"rtsp.onvif.org"},
+	}).DialContext(ctx, ur, nil) //nolint:bodyclose
+	if err != nil {
+		return nil, err
+	}
+
+	c.r = &wsReader{wc: c.wconn}
+	c.w = &wsWriter{wc: c.wconn}
+
+	return c, nil
+}