Make QUIC stateless rejects work in the face of packet loss by storing the SREJ packet(s) in the Qu…

net/quic/quic_crypto_server_stream.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_crypto_server_stream.h"
 
 #include "base/base64.h"
 #include "crypto/secure_hash.h"
 #include "net/quic/crypto/crypto_protocol.h"
 #include "net/quic/crypto/crypto_utils.h"
@@ skipping 90 matching lines @@
   string error_details;
   QuicErrorCode error =
       ProcessClientHello(message, result, &reply, &error_details);
 
   if (error != QUIC_NO_ERROR) {
     CloseConnectionWithDetails(error, error_details);
     return;
   }
 
   if (reply.tag() != kSHLO) {
+    if (FLAGS_enable_quic_stateless_reject_support &&
+        reply.tag() == kSREJ) {
+      // Before sending the SREJ, cause the connection to save crypto packets
+      // so that they can be added to the time wait list manager and
+      // retransmitted.
+      session()->connection()->EnableSavingCryptoPackets();
+    }
     SendHandshakeMessage(reply);
 
     if (FLAGS_enable_quic_stateless_reject_support && reply.tag() == kSREJ) {
       DCHECK(use_stateless_rejects_if_peer_supported());
       DCHECK(peer_supports_stateless_rejects());
       DCHECK(!handshake_confirmed());
       DVLOG(1) << "Closing connection "
                << session()->connection()->connection_id()
                << " because of a stateless reject.";
       session()->connection()->CloseConnection(
@@ skipping 191 matching lines @@
   }
   for (size_t i = 0; i < received_tags_length; ++i) {
     if (received_tags[i] == kSREJ) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace net