From 4793e9e3cee22c2e9b651f524af904aca3be825d Mon Sep 17 00:00:00 2001
From: Philipp Hancke <philipp.hancke@googlemail.com>
Date: Tue, 15 Dec 2020 12:40:57 +0100
Subject: [PATCH] sdp: ignore legacy sctpmap line

and reorganise the parsing

Bug: None
Change-Id: I21f08297429a0cc0265da00daa681d934fc43d66
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/196643
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32843}
---
 pc/webrtc_sdp.cc | 64 ++++++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 29 deletions(-)

diff --git a/pc/webrtc_sdp.cc b/pc/webrtc_sdp.cc
index 7f61a26293..14eb0df922 100644
--- a/pc/webrtc_sdp.cc
+++ b/pc/webrtc_sdp.cc
@@ -3128,38 +3128,44 @@ bool ParseContent(const std::string& message,
       if (!ParseDtlsSetup(line, &(transport->connection_role), error)) {
         return false;
       }
-    } else if (cricket::IsDtlsSctp(protocol) &&
-               HasAttribute(line, kAttributeSctpPort)) {
-      if (media_type != cricket::MEDIA_TYPE_DATA) {
-        return ParseFailed(
-            line, "sctp-port attribute found in non-data media description.",
-            error);
+    } else if (cricket::IsDtlsSctp(protocol)) {
+      //
+      // SCTP specific attributes
+      //
+      if (HasAttribute(line, kAttributeSctpPort)) {
+        if (media_type != cricket::MEDIA_TYPE_DATA) {
+          return ParseFailed(
+              line, "sctp-port attribute found in non-data media description.",
+              error);
+        }
+        if (media_desc->as_sctp()->use_sctpmap()) {
+          return ParseFailed(
+              line, "sctp-port attribute can't be used with sctpmap.", error);
+        }
+        int sctp_port;
+        if (!ParseSctpPort(line, &sctp_port, error)) {
+          return false;
+        }
+        media_desc->as_sctp()->set_port(sctp_port);
+      } else if (HasAttribute(line, kAttributeMaxMessageSize)) {
+        if (media_type != cricket::MEDIA_TYPE_DATA) {
+          return ParseFailed(
+              line,
+              "max-message-size attribute found in non-data media description.",
+              error);
+        }
+        int max_message_size;
+        if (!ParseSctpMaxMessageSize(line, &max_message_size, error)) {
+          return false;
+        }
+        media_desc->as_sctp()->set_max_message_size(max_message_size);
+      } else if (HasAttribute(line, kAttributeSctpmap)) {
+        // Ignore a=sctpmap: from early versions of draft-ietf-mmusic-sctp-sdp
+        continue;
       }
-      if (media_desc->as_sctp()->use_sctpmap()) {
-        return ParseFailed(
-            line, "sctp-port attribute can't be used with sctpmap.", error);
-      }
-      int sctp_port;
-      if (!ParseSctpPort(line, &sctp_port, error)) {
-        return false;
-      }
-      media_desc->as_sctp()->set_port(sctp_port);
-    } else if (cricket::IsDtlsSctp(protocol) &&
-               HasAttribute(line, kAttributeMaxMessageSize)) {
-      if (media_type != cricket::MEDIA_TYPE_DATA) {
-        return ParseFailed(
-            line,
-            "max-message-size attribute found in non-data media description.",
-            error);
-      }
-      int max_message_size;
-      if (!ParseSctpMaxMessageSize(line, &max_message_size, error)) {
-        return false;
-      }
-      media_desc->as_sctp()->set_max_message_size(max_message_size);
     } else if (cricket::IsRtpProtocol(protocol)) {
       //
-      // RTP specific attrubtes
+      // RTP specific attributes
       //
       if (HasAttribute(line, kAttributeRtcpMux)) {
         media_desc->set_rtcp_mux(true);