commit 46053e4aae3650035438a5ecda751ff44ad1bb25
author Henrik Boström <hbos@webrtc.org> Fri Jan 20 12:18:53 2023
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Jan 20 13:31:07 2023
tree e1679030e5996cc564435c8826eb43b2b83412f6
parent 124d7c3fe5bdc79a355c9df02d07f25331631a68

Handle the case of missing certificates.

Creating a data channel or negotiating it can make the SCTP transport
name go from nothing (empty string) to something. Inside the
RTCStatsCollector this is relevant because which transports we have
affect which certificates we should cache, so this is an instance of
having to call ClearStatsCache().

The bug is that we don't. This CL fixes the bug.

I tried to create unittests to cover this, but I was unable to
reproduce the race in a testing environment (if I did it would have
hit an RTC_DCHECK). Not ideal... but I hope we can land it anyway since
the fix is trivial and clearing the cache in response to API calls is
worst case harmless.

Bug: webrtc:14844
Change-Id: Ia7174cde040839e5555237db6de285297120b123
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/291112
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39160}

pc/peer_connection.cc

diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 36ffd11..2e74340 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -2097,7 +2097,7 @@
 void PeerConnection::ResetSctpDataMid() {
   RTC_DCHECK_RUN_ON(signaling_thread());
   sctp_mid_s_.reset();
-  sctp_transport_name_s_.clear();
+  SetSctpTransportName("");
 }
 
 void PeerConnection::OnSctpDataChannelClosed(DataChannelInterface* channel) {
@@ -2305,6 +2305,12 @@
   return absl::optional<std::string>();
 }
 
+void PeerConnection::SetSctpTransportName(std::string sctp_transport_name) {
+  RTC_DCHECK_RUN_ON(signaling_thread());
+  sctp_transport_name_s_ = std::move(sctp_transport_name);
+  ClearStatsCache();
+}
+
 absl::optional<std::string> PeerConnection::sctp_mid() const {
   RTC_DCHECK_RUN_ON(signaling_thread());
   return sctp_mid_s_;
@@ -2534,7 +2540,7 @@
         SafeTask(signaling_thread_safety_.flag(),
                  [this, name = dtls_transport->transport_name()] {
                    RTC_DCHECK_RUN_ON(signaling_thread());
-                   sctp_transport_name_s_ = std::move(name);
+                   SetSctpTransportName(std::move(name));
                  }));
   }
 
@@ -2922,7 +2928,7 @@
           [this,
            name = std::string(dtls_transport->internal()->transport_name())] {
             RTC_DCHECK_RUN_ON(signaling_thread());
-            sctp_transport_name_s_ = std::move(name);
+            SetSctpTransportName(std::move(name));
           }));
     }
   }