snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

internal/mux/muxfunc.go

@@ -0,0 +1,67 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+package mux
+
+// MatchFunc allows custom logic for mapping packets to an Endpoint.
+type MatchFunc func([]byte) bool
+
+// MatchAll always returns true.
+func MatchAll([]byte) bool {
+	return true
+}
+
+// MatchRange returns true if the first byte of buf is in [lower..upper].
+func MatchRange(lower, upper byte, buf []byte) bool {
+	if len(buf) < 1 {
+		return false
+	}
+	b := buf[0]
+
+	return b >= lower && b <= upper
+}
+
+// MatchFuncs as described in RFC7983
+// https://tools.ietf.org/html/rfc7983
+//              +----------------+
+//              |        [0..3] -+--> forward to STUN
+//              |                |
+//              |      [16..19] -+--> forward to ZRTP
+//              |                |
+//  packet -->  |      [20..63] -+--> forward to DTLS
+//              |                |
+//              |      [64..79] -+--> forward to TURN Channel
+//              |                |
+//              |    [128..191] -+--> forward to RTP/RTCP
+//              +----------------+
+
+// MatchDTLS is a MatchFunc that accepts packets with the first byte in [20..63]
+// as defied in RFC7983.
+func MatchDTLS(b []byte) bool {
+	return MatchRange(20, 63, b)
+}
+
+// MatchSRTPOrSRTCP is a MatchFunc that accepts packets with the first byte in [128..191]
+// as defied in RFC7983.
+func MatchSRTPOrSRTCP(b []byte) bool {
+	return MatchRange(128, 191, b)
+}
+
+func isRTCP(buf []byte) bool {
+	// Not long enough to determine RTP/RTCP
+	if len(buf) < 4 {
+		return false
+	}
+
+	return buf[1] >= 192 && buf[1] <= 223
+}
+
+// MatchSRTP is a MatchFunc that only matches SRTP and not SRTCP.
+func MatchSRTP(buf []byte) bool {
+	return MatchSRTPOrSRTCP(buf) && !isRTCP(buf)
+}
+
+// MatchSRTCP is a MatchFunc that only matches SRTCP and not SRTP.
+func MatchSRTCP(buf []byte) bool {
+	return MatchSRTPOrSRTCP(buf) && isRTCP(buf)
+}