QUIC - disable QUIC if packet loss rate is bad for a connection.

net/quic/quic_stream_factory.cc

Index: net/quic/quic_stream_factory.cc
diff --git a/net/quic/quic_stream_factory.cc b/net/quic/quic_stream_factory.cc
index 2e8508d7629c8b3544862762e524d087b54e8729..9c751575332ec20b62ca38356356c3b398e9fa70 100644
--- a/net/quic/quic_stream_factory.cc
+++ b/net/quic/quic_stream_factory.cc
@@ -436,7 +436,8 @@ int QuicStreamFactory::Job::DoConnect() {
     return ERR_QUIC_PROTOCOL_ERROR;
   }
   bool require_confirmation =
-      factory_->require_confirmation() || is_post_ ||
+      factory_->require_confirmation() ||
+      is_post_ ||
       was_alternate_protocol_recently_broken_;
 
   rv = session_->CryptoConnect(
@@ -539,6 +540,8 @@ QuicStreamFactory::QuicStreamFactory(
     bool enable_connection_racing,
     bool enable_non_blocking_io,
     bool disable_disk_cache,
+    int number_of_lossy_handshakes,
+    int packet_loss_threshold,
     int socket_receive_buffer_size,
     const QuicTagVector& connection_options)
     : require_confirmation_(true),
@@ -562,6 +565,10 @@ QuicStreamFactory::QuicStreamFactory(
       enable_connection_racing_(enable_connection_racing),
       enable_non_blocking_io_(enable_non_blocking_io),
       disable_disk_cache_(disable_disk_cache),
+      number_of_lossy_handshakes_(number_of_lossy_handshakes),
+      packet_loss_threshold_(packet_loss_threshold),
+      disable_zero_rtt_(number_of_lossy_handshakes_ > 0 &&
+                        packet_loss_threshold_ > 0),
       socket_receive_buffer_size_(socket_receive_buffer_size),
       port_seed_(random_generator_->RandUint64()),
       check_persisted_supports_quic_(true),
@@ -628,7 +635,7 @@ int QuicStreamFactory::Create(const HostPortPair& host_port_pair,
 
   QuicServerInfo* quic_server_info = nullptr;
   if (quic_server_info_factory_) {
-    bool load_from_disk_cache = !disable_disk_cache_;
+    bool load_from_disk_cache = !disable_disk_cache_ || !disable_zero_rtt_;
     if (http_server_properties_) {
       const AlternateProtocolMap& alternate_protocol_map =
           http_server_properties_->alternate_protocol_map();
@@ -763,6 +770,36 @@ scoped_ptr<QuicHttpStream> QuicStreamFactory::CreateIfSessionExists(
       new QuicHttpStream(session->GetWeakPtr()));
 }
 
+QuicErrorCode QuicStreamFactory::OnCryptoHandshakeCompleted(
+    QuicClientSession* session,
+    const QuicServerId& server_id,
+    int number_of_handshakes) {
+  DCHECK_LT(0, number_of_handshakes);
+  if (number_of_handshakes != number_of_lossy_handshakes_)
+    return QUIC_NO_ERROR;
+
+  bool bad_packet_loss_rate =
+      (session->PacketLossRate() / 10) > packet_loss_threshold_;
+
+  UMA_HISTOGRAM_BOOLEAN("Net.QuicSession.HasBadPacketLossRate",
+                        bad_packet_loss_rate);
+
+  // It is not bad packet loss rate, enable 0-RTT.
+  if (!bad_packet_loss_rate) {
+    disable_zero_rtt_ = false;
+    return QUIC_NO_ERROR;
+  }
+
+  HistogramBrokenAlternateProtocolLocation(
+      BROKEN_ALTERNATE_PROTOCOL_LOCATION_QUIC_STREAM_FACTORY);
+
+  const HostPortPair& server = server_id.host_port_pair();
+  http_server_properties_->MarkAlternativeServiceRecentlyBroken(
+        AlternativeService(QUIC, server.host(), server.port()));
+  // TODO(rtenneti): Should we close the connection?
+  return QUIC_BAD_PACKET_LOSS_RATE;
+}
+
 void QuicStreamFactory::OnIdleSession(QuicClientSession* session) {
 }