Handle case where UDP packet contains multiple DTLS records.

webrtc/p2p/base/dtlstransportchannel.cc

 /*
  *  Copyright 2011 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.
  */
 
@@ skipping 519 matching lines @@
       // The check for OPEN shouldn't be necessary but let's make
       // sure we don't accidentally frob the state if it's closed.
       set_dtls_state(DTLS_TRANSPORT_CONNECTED);
       set_writable(true);
     }
   }
   if (sig & rtc::SE_READ) {
     char buf[kMaxDtlsPacketLen];
     size_t read;
     int read_error;
-    rtc::StreamResult ret = dtls_->Read(buf, sizeof(buf), &read, &read_error);
-    if (ret == rtc::SR_SUCCESS) {
-      SignalReadPacket(this, buf, read, rtc::CreatePacketTime(0), 0);
-    } else if (ret == rtc::SR_EOS) {
-      // Remote peer shut down the association with no error.
-      LOG_J(LS_INFO, this) << "DTLS transport closed";
-      set_writable(false);
-      set_dtls_state(DTLS_TRANSPORT_CLOSED);
-    } else if (ret == rtc::SR_ERROR) {
-      // Remote peer shut down the association with an error.
-      LOG_J(LS_INFO, this) << "DTLS transport error, code=" << read_error;
-      set_writable(false);
-      set_dtls_state(DTLS_TRANSPORT_FAILED);
-    }
+    rtc::StreamResult ret;
+    do {

[Taylor Brandstetter, 2017/07/06 22:06:11]

Could use a comment explaining why this is done in a loop.

[joachim, 2017/07/07 16:12:59]

Done.

+      ret = dtls_->Read(buf, sizeof(buf), &read, &read_error);
+      if (ret == rtc::SR_SUCCESS) {
+        SignalReadPacket(this, buf, read, rtc::CreatePacketTime(0), 0);
+      } else if (ret == rtc::SR_EOS) {
+        // Remote peer shut down the association with no error.
+        LOG_J(LS_INFO, this) << "DTLS transport closed";
+        set_writable(false);
+        set_dtls_state(DTLS_TRANSPORT_CLOSED);
+      } else if (ret == rtc::SR_ERROR) {
+        // Remote peer shut down the association with an error.
+        LOG_J(LS_INFO, this) << "DTLS transport error, code=" << read_error;
+        set_writable(false);
+        set_dtls_state(DTLS_TRANSPORT_FAILED);
+      }
+    } while (ret == rtc::SR_SUCCESS);
   }
   if (sig & rtc::SE_CLOSE) {
     RTC_DCHECK(sig == rtc::SE_CLOSE);  // SE_CLOSE should be by itself.
     set_writable(false);
     if (!err) {
       LOG_J(LS_INFO, this) << "DTLS transport closed";
       set_dtls_state(DTLS_TRANSPORT_CLOSED);
     } else {
       LOG_J(LS_INFO, this) << "DTLS transport error, code=" << err;
       set_dtls_state(DTLS_TRANSPORT_FAILED);
@@ skipping 109 matching lines @@
 
     dtls_->SetInitialRetransmissionTimeout(initial_timeout);
   } else {
     LOG_J(LS_INFO, this)
         << "no RTT estimate - using default DTLS handshake timeout";
   }
 }
 
 
 }  // namespace cricket