Parse the connection data in SDP (c= line).

webrtc/pc/webrtcsdp.cc

Index: webrtc/pc/webrtcsdp.cc
diff --git a/webrtc/pc/webrtcsdp.cc b/webrtc/pc/webrtcsdp.cc
index 13d09a6ee96efd33219e6e7df89ba5983cb49d7e..404e45fe0c53547375a1fb910205f0b37d52ca55 100644
--- a/webrtc/pc/webrtcsdp.cc
+++ b/webrtc/pc/webrtcsdp.cc
@@ -1900,6 +1900,31 @@ bool IsDtlsSctp(const std::string& protocol) {
   return protocol.find(cricket::kMediaProtocolDtlsSctp) != std::string::npos;
 }
 
+bool ParseConnectionData(const std::string line, rtc::SocketAddress* addr) {

[Taylor Brandstetter, 2017/03/10 22:41:18]

Meant to be const ref string?

[Zhi Huang, 2017/03/15 04:04:59]

Ah, yes. I missed the &.

+  // Parse the line from left to right.
+  std::string token;
+  std::string rightpart;
+  // RFC 4566
+  // c=<nettype> <addrtype> <connection-address>
+  // Skip "c=<nettype>".

[Taylor Brandstetter, 2017/03/10 22:41:18]

We should verify that "nettype" is "IN" since that's all we support.

[Zhi Huang, 2017/03/15 04:04:59]

Done.

+  if (!rtc::tokenize_first(line, kSdpDelimiterSpace, &token, &rightpart)) {
+    return false;
+  }
+  // Skip the "<addrtype>".

[Taylor Brandstetter, 2017/03/10 22:41:18]

To be more thorough, we could verify that addrtype matches the type of the
parsed address (IP4 or IP6), if the address is a literal IP address and not a
domain name.

[Zhi Huang, 2017/03/15 04:04:59]

Done.

+  if (!rtc::tokenize_first(rightpart, kSdpDelimiterSpace, &token, &rightpart)) {
+    return false;
+  }
+  // Extract the IP address. The rightpart part should be the IP address without
+  // the slash which is used for multicast.
+  if (rightpart.find('/') != std::string::npos) {
+    LOG(LS_ERROR) << "Failed to parse the connection data. Multicast is not "

[Taylor Brandstetter, 2017/03/10 22:41:18]

This method should take an error output parameter and do:

return ParseFailed(
    line,
    "Failed to parse the connection data. Multicast is not currently
supported.",
    error);

In order to return errors.

[Zhi Huang, 2017/03/15 04:04:59]

Done.

+                     "currently supported.";
+    return false;
+  }
+  addr->SetIP(rightpart);
+  return true;
+}
+
 bool ParseSessionDescription(const std::string& message, size_t* pos,
                              std::string* session_id,
                              std::string* session_version,
@@ -1962,7 +1987,15 @@ bool ParseSessionDescription(const std::string& message, size_t* pos,
   // RFC 4566
   // c=* (connection information -- not required if included in
   //      all media)
-  GetLineWithType(message, pos, &line, kLineTypeConnection);
+  if (GetLineWithType(message, pos, &line, kLineTypeConnection)) {
+    rtc::SocketAddress addr;
+    if (!ParseConnectionData(line, &addr)) {
+      LOG(LS_ERROR) << "Failed to parse the session level connection data:"

[Taylor Brandstetter, 2017/03/10 22:41:18]

This doesn't need to log an error if ParseConnectionData already did.

[Zhi Huang, 2017/03/15 04:04:59]

Done.

+                    << line;
+      return false;
+    }
+    desc->set_session_connection_addr(rtc::Optional<rtc::SocketAddress>(addr));
+  }
 
   // RFC 4566
   // b=* (zero or more bandwidth information lines)
@@ -2266,7 +2299,7 @@ static C* ParseContentDescription(const std::string& message,
                     pos, content_name, bundle_only, media_desc, transport,
                     candidates, error)) {
     delete media_desc;
-    return NULL;
+    return nullptr;
   }
   // Sort the codecs according to the m-line fmt list.
   std::unordered_map<int, int> payload_type_preferences;
@@ -2668,6 +2701,19 @@ bool ParseContent(const std::string& message,
       continue;
     }
 
+    // Parse the media level connection data.
+    if (IsLineType(line, kLineTypeConnection)) {
+      rtc::SocketAddress addr;
+      if (!ParseConnectionData(line, &addr)) {
+        LOG(LS_ERROR) << "Failed to parse the session level connection data:"
+                      << line;
+        return false;
+      }
+      media_desc->set_media_connection_addr(
+          rtc::Optional<rtc::SocketAddress>(addr));
+      continue;
+    }
+
     if (!IsLineType(line, kLineTypeAttributes)) {
       // TODO: Handle other lines if needed.
       LOG(LS_INFO) << "Ignored line: " << line;