Repo created

TMessagesProj/jni/voip/webrtc/pc/media_protocol_names.cc

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+/*
+ *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "pc/media_protocol_names.h"
+
+#include <ctype.h>
+#include <stddef.h>
+
+#include <string>
+
+namespace cricket {
+
+// The official registry of RTP parameters is at
+// http://www.iana.org/assignments/rtp-parameters/rtp-parameters.xml
+// The UDP/DTLS and TCP/DTLS prefixes are not registered there.
+
+// There are multiple variants of the RTP protocol stack, including
+// UDP/TLS/RTP/SAVPF (WebRTC default), RTP/AVP, RTP/AVPF, RTP/SAVPF,
+// TCP/DTLS/RTP/SAVPF and so on. We accept anything that has RTP/
+// embedded in it somewhere as being an RTP protocol.
+const char kMediaProtocolRtpPrefix[] = "RTP/";
+
+// Protocol names generated by WebRTC
+const char kMediaProtocolSctp[] = "SCTP";
+const char kMediaProtocolUdpDtlsSctp[] = "UDP/DTLS/SCTP";
+const char kMediaProtocolDtlsSctp[] = "DTLS/SCTP";
+const char kMediaProtocolTcpDtlsSctp[] = "TCP/DTLS/SCTP";
+// RFC5124
+const char kMediaProtocolDtlsSavpf[] = "UDP/TLS/RTP/SAVPF";
+const char kMediaProtocolSavpf[] = "RTP/SAVPF";
+const char kMediaProtocolAvpf[] = "RTP/AVPF";
+
+namespace {
+
+// Protocol names that we tolerate, but do not generate.
+// We always generate offers with "UDP/TLS/RTP/SAVPF" when using DTLS-SRTP,
+// but we tolerate "RTP/SAVPF" and "RTP/SAVP" and the "UDP/TLS" and "TCP/TLS"
+// prefixes in offers we receive, for compatibility.
+// RFC4585
+const char kMediaProtocolSavp[] = "RTP/SAVP";
+const char kMediaProtocolAvp[] = "RTP/AVP";
+
+const char kMediaProtocolTcpTlsSavpf[] = "TCP/TLS/RTP/SAVPF";
+const char kMediaProtocolUdpTlsSavpf[] = "UDP/TLS/RTP/SAVPF";
+const char kMediaProtocolTcpTlsSavp[] = "TCP/TLS/RTP/SAVP";
+const char kMediaProtocolUdpTlsSavp[] = "UDP/TLS/RTP/SAVP";
+
+}  // namespace
+
+bool IsDtlsSctp(absl::string_view protocol) {
+  return protocol == kMediaProtocolDtlsSctp ||
+         protocol == kMediaProtocolUdpDtlsSctp ||
+         protocol == kMediaProtocolTcpDtlsSctp;
+}
+
+bool IsPlainSctp(absl::string_view protocol) {
+  return protocol == kMediaProtocolSctp;
+}
+
+bool IsSctpProtocol(absl::string_view protocol) {
+  return IsPlainSctp(protocol) || IsDtlsSctp(protocol);
+}
+
+bool IsRtpProtocol(absl::string_view protocol) {
+  if (protocol.empty()) {
+    return true;
+  }
+  size_t pos = protocol.find(cricket::kMediaProtocolRtpPrefix);
+  if (pos == std::string::npos) {
+    return false;
+  }
+  // RTP must be at the beginning of a string or not preceded by alpha
+  if (pos == 0 || !isalpha(static_cast<unsigned char>(protocol[pos - 1]))) {
+    return true;
+  }
+  return false;
+}
+
+// Note that the below functions support some protocol strings purely for
+// legacy compatibility, as required by JSEP in Section 5.1.2, Profile Names
+// and Interoperability.
+
+bool IsDtlsRtp(absl::string_view protocol) {
+  // Most-likely values first.
+  return protocol == kMediaProtocolDtlsSavpf ||
+         protocol == kMediaProtocolTcpTlsSavpf ||
+         protocol == kMediaProtocolUdpTlsSavpf ||
+         protocol == kMediaProtocolUdpTlsSavp ||
+         protocol == kMediaProtocolTcpTlsSavp;
+}
+
+bool IsPlainRtp(absl::string_view protocol) {
+  // Most-likely values first.
+  return protocol == kMediaProtocolSavpf || protocol == kMediaProtocolAvpf ||
+         protocol == kMediaProtocolSavp || protocol == kMediaProtocolAvp;
+}
+
+}  // namespace cricket