Land Recent QUIC changes.

net/quic/quic_packet_creator.cc

Index: net/quic/quic_packet_creator.cc
diff --git a/net/quic/quic_packet_creator.cc b/net/quic/quic_packet_creator.cc
index 2cdfd69f67fb2bd0125fe1cb1d847f66654859a0..c8d132fe8329d4c2d542bc659cbf847ac789d84b 100644
--- a/net/quic/quic_packet_creator.cc
+++ b/net/quic/quic_packet_creator.cc
@@ -28,7 +28,9 @@ QuicPacketCreator::QuicPacketCreator(QuicGuid guid,
       fec_group_number_(0),
       is_server_(is_server),
       send_version_in_packet_(!is_server),
-      packet_size_(GetPacketHeaderSize(send_version_in_packet_)) {
+      packet_size_(GetPacketHeaderSize(options_.send_guid_length,
+                                       send_version_in_packet_,
+                                       NOT_IN_FEC_GROUP)) {
   framer_->set_fec_builder(this);
 }
 
@@ -43,16 +45,21 @@ void QuicPacketCreator::OnBuiltFecProtectedPayload(
 }
 
 bool QuicPacketCreator::ShouldSendFec(bool force_close) const {
-  return fec_group_.get() != NULL &&
+  return fec_group_.get() != NULL && fec_group_->NumReceivedPackets() > 0 &&
       (force_close ||
        fec_group_->NumReceivedPackets() >= options_.max_packets_per_fec_group);
 }
 
 void QuicPacketCreator::MaybeStartFEC() {
   if (options_.max_packets_per_fec_group > 0 && fec_group_.get() == NULL) {
+    DCHECK(queued_frames_.empty());
     // Set the fec group number to the sequence number of the next packet.
     fec_group_number_ = sequence_number() + 1;
     fec_group_.reset(new QuicFecGroup());
+    packet_size_ = GetPacketHeaderSize(options_.send_guid_length,
+                                       send_version_in_packet_,
+                                       IN_FEC_GROUP);
+    DCHECK_LE(packet_size_, options_.max_packet_length);
   }
 }
 
@@ -73,9 +80,12 @@ bool QuicPacketCreator::HasRoomForStreamFrame() const {
 }
 
 // static
-size_t QuicPacketCreator::StreamFramePacketOverhead(int num_frames,
-                                                    bool include_version) {
-  return GetPacketHeaderSize(include_version) +
+size_t QuicPacketCreator::StreamFramePacketOverhead(
+    int num_frames,
+    QuicGuidLength guid_length,
+    bool include_version,
+    InFecGroup is_in_fec_group) {
+  return GetPacketHeaderSize(guid_length, include_version, is_in_fec_group) +
       QuicFramer::GetMinStreamFrameSize() * num_frames;
 }
 
@@ -85,7 +95,8 @@ size_t QuicPacketCreator::CreateStreamFrame(QuicStreamId id,
                                             bool fin,
                                             QuicFrame* frame) {
   DCHECK_GT(options_.max_packet_length,
-            StreamFramePacketOverhead(1, kIncludeVersion));
+            StreamFramePacketOverhead(
+                1, PACKET_8BYTE_GUID, kIncludeVersion, IN_FEC_GROUP));
   DCHECK(HasRoomForStreamFrame());
 
   const size_t free_bytes = BytesFree();
@@ -147,7 +158,10 @@ SerializedPacket QuicPacketCreator::SerializePacket() {
   SerializedPacket serialized = framer_->ConstructFrameDataPacket(
       header, queued_frames_, packet_size_);
   queued_frames_.clear();
-  packet_size_ = GetPacketHeaderSize(send_version_in_packet_);
+  packet_size_ = GetPacketHeaderSize(options_.send_guid_length,
+                                     send_version_in_packet_,
+                                     fec_group_.get() != NULL ?
+                                         IN_FEC_GROUP : NOT_IN_FEC_GROUP);
   serialized.retransmittable_frames = queued_retransmittable_frames_.release();
   return serialized;
 }
@@ -164,6 +178,10 @@ SerializedPacket QuicPacketCreator::SerializeFec() {
   SerializedPacket serialized = framer_->ConstructFecPacket(header, fec_data);
   fec_group_.reset(NULL);
   fec_group_number_ = 0;
+  // Reset packet_size_, since the next packet may not have an FEC group.
+  packet_size_ = GetPacketHeaderSize(options_.send_guid_length,
+                                     send_version_in_packet_,
+                                     NOT_IN_FEC_GROUP);
   DCHECK(serialized.packet);
   DCHECK_GE(options_.max_packet_length, serialized.packet->length());
   return serialized;
@@ -199,15 +217,23 @@ void QuicPacketCreator::FillPacketHeader(QuicFecGroupNumber fec_group,
   header->public_header.reset_flag = false;
   header->public_header.version_flag = send_version_in_packet_;
   header->fec_flag = fec_flag;
-  header->fec_entropy_flag = fec_entropy_flag;
   header->packet_sequence_number = ++sequence_number_;
+
+  bool entropy_flag;
   if (header->packet_sequence_number == 1) {
+    DCHECK(!fec_flag);
     // TODO(satyamshekhar): No entropy in the first message.
     // For crypto tests to pass. Fix this by using deterministic QuicRandom.
-    header->entropy_flag = 0;
+    entropy_flag = 0;
+  } else if (fec_flag) {
+    // FEC packets don't have an entropy of their own. Entropy flag for FEC
+    // packets is the XOR of entropy of previous packets.
+    entropy_flag = fec_entropy_flag;
   } else {
-    header->entropy_flag = random_generator_->RandBool();
+    entropy_flag = random_generator_->RandBool();
   }
+  header->entropy_flag = entropy_flag;
+  header->is_in_fec_group = fec_group == 0 ? NOT_IN_FEC_GROUP : IN_FEC_GROUP;
   header->fec_group = fec_group;
 }