Stop using next_packet_sequence_number_length in QuicPacketCreator. No functional change. Protect…

net/quic/quic_packet_creator_test.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_packet_creator.h"
 
 #include <cstdint>
 #include <memory>
 #include <string>
 
@@ skipping 161 matching lines @@
     EXPECT_EQ(stream_id, frame.stream_frame->stream_id);
     EXPECT_EQ(data, StringPiece(frame.stream_frame->data_buffer,
                                 frame.stream_frame->data_length));
     EXPECT_EQ(offset, frame.stream_frame->offset);
     EXPECT_EQ(fin, frame.stream_frame->fin);
   }
 
   // Returns the number of bytes consumed by the header of packet, including
   // the version.
   size_t GetPacketHeaderOverhead(QuicVersion version) {
-    return GetPacketHeaderSize(
-        version, creator_.connection_id_length(), kIncludeVersion,
-        !kIncludePathId, !kIncludeDiversificationNonce,
-        QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
+    if (FLAGS_quic_simple_packet_number_length) {
+      return GetPacketHeaderSize(
+          version, creator_.connection_id_length(), kIncludeVersion,
+          !kIncludePathId, !kIncludeDiversificationNonce,
+          QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+    } else {
+      return GetPacketHeaderSize(
+          version, creator_.connection_id_length(), kIncludeVersion,
+          !kIncludePathId, !kIncludeDiversificationNonce,
+          QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
+    }
   }
 
   // Returns the number of bytes of overhead that will be added to a packet
   // of maximum length.
   size_t GetEncryptionOverhead() {
     return creator_.max_packet_length() -
            client_framer_.GetMaxPlaintextSize(creator_.max_packet_length());
   }
 
   // Returns the number of bytes consumed by the non-data fields of a stream
@@ skipping 70 matching lines @@
       EXPECT_CALL(framer_visitor_, OnAckFrame(_));
       EXPECT_CALL(framer_visitor_, OnStreamFrame(_));
       EXPECT_CALL(framer_visitor_, OnStreamFrame(_));
       EXPECT_CALL(framer_visitor_, OnPacketComplete());
     }
     ProcessPacket(serialized);
   }
 }
 
 TEST_P(QuicPacketCreatorTest, SerializeChangingSequenceNumberLength) {
+  FLAGS_quic_simple_packet_number_length = false;
   frames_.push_back(QuicFrame(new QuicAckFrame(MakeAckFrame(0u))));
   creator_.AddSavedFrame(frames_[0]);
   QuicPacketCreatorPeer::SetNextPacketNumberLength(&creator_,
                                                    PACKET_4BYTE_PACKET_NUMBER);
 
   EXPECT_CALL(delegate_, OnSerializedPacket(_))
       .WillRepeatedly(
           Invoke(this, &QuicPacketCreatorTest::SaveSerializedPacket));
   creator_.Flush();
   // The packet number length will not change mid-packet.
@@ skipping 28 matching lines @@
     EXPECT_CALL(framer_visitor_, OnDecryptedPacket(_));
     EXPECT_CALL(framer_visitor_, OnPacketHeader(_));
     EXPECT_CALL(framer_visitor_, OnAckFrame(_));
     EXPECT_CALL(framer_visitor_, OnPacketComplete());
   }
   ProcessPacket(serialized_packet_);
   DeleteSerializedPacket();
 }
 
 TEST_P(QuicPacketCreatorTest, ChangeSequenceNumberLengthMidPacket) {
+  FLAGS_quic_simple_packet_number_length = false;
   // Changing the packet number length with queued frames in the creator
   // should hold the change until after any currently queued frames are
   // serialized.
 
   // Packet 1.
   // Queue a frame in the creator.
   EXPECT_FALSE(creator_.HasPendingFrames());
   QuicFrame ack_frame = QuicFrame(new QuicAckFrame(MakeAckFrame(0u)));
   creator_.AddSavedFrame(ack_frame);
 
@@ skipping 61 matching lines @@
     EXPECT_CALL(framer_visitor_, OnPacketComplete());
   }
   ProcessPacket(serialized_packet_);
   EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
             header.public_header.packet_number_length);
 
   DeleteSerializedPacket();
   delete ack_frame.ack_frame;
 }
 
+TEST_P(QuicPacketCreatorTest, ChangeSequenceNumberLengthMidPacketDoesNothing) {
+  FLAGS_quic_simple_packet_number_length = true;
+  EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+  // Changing the packet number length with queued frames in the creator
+  // should do nothing.
+  EXPECT_FALSE(creator_.HasPendingFrames());
+  QuicFrame ack_frame = QuicFrame(new QuicAckFrame(MakeAckFrame(0u)));
+  creator_.AddSavedFrame(ack_frame);
+
+  // Now change packet number length and expect a QUIC_BUG and no change in
+  // packet number length.
+  EXPECT_DFATAL(creator_.UpdatePacketNumberLength(0, 256),
+                "Called UpdatePacketNumberLength with 1 queued_frames.");
+  EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+  delete ack_frame.ack_frame;
+}
+
 TEST_P(QuicPacketCreatorTest, ReserializeFramesWithSequenceNumberLength) {
   // If the original packet number length, the current packet number
   // length, and the configured send packet number length are different, the
   // retransmit must sent with the original length and the others do not change.
-  QuicPacketCreatorPeer::SetNextPacketNumberLength(&creator_,
-                                                   PACKET_4BYTE_PACKET_NUMBER);
+  if (!FLAGS_quic_simple_packet_number_length) {
+    QuicPacketCreatorPeer::SetNextPacketNumberLength(
+        &creator_, PACKET_4BYTE_PACKET_NUMBER);
+  }
   QuicPacketCreatorPeer::SetPacketNumberLength(&creator_,
                                                PACKET_2BYTE_PACKET_NUMBER);
   QuicStreamFrame* stream_frame =
       new QuicStreamFrame(kCryptoStreamId, /*fin=*/false, 0u, StringPiece());
   QuicFrames frames;
   frames.push_back(QuicFrame(stream_frame));
   char buffer[kMaxPacketSize];
   PendingRetransmission retransmission(CreateRetransmission(
       frames, true /* has_crypto_handshake */, -1 /* needs full padding */,
       ENCRYPTION_NONE, PACKET_1BYTE_PACKET_NUMBER));
   EXPECT_CALL(delegate_, OnSerializedPacket(_))
       .WillOnce(Invoke(this, &QuicPacketCreatorTest::SaveSerializedPacket));
   creator_.ReserializeAllFrames(retransmission, buffer, kMaxPacketSize);
-  EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
-            QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
-  EXPECT_EQ(PACKET_2BYTE_PACKET_NUMBER,
-            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+  if (FLAGS_quic_simple_packet_number_length) {
+    // The packet number length is updated after every packet is sent,
+    // so there is no need to restore the old length after sending.
+    EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+              QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+  } else {
+    EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
+              QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
+    EXPECT_EQ(PACKET_2BYTE_PACKET_NUMBER,
+              QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+  }
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             serialized_packet_.packet_number_length);
 
   {
     InSequence s;
     EXPECT_CALL(framer_visitor_, OnPacket());
     EXPECT_CALL(framer_visitor_, OnUnauthenticatedPublicHeader(_));
     EXPECT_CALL(framer_visitor_, OnUnauthenticatedHeader(_));
     EXPECT_CALL(framer_visitor_, OnDecryptedPacket(_));
     EXPECT_CALL(framer_visitor_, OnPacketHeader(_));
@@ skipping 68 matching lines @@
 
   const int kNumPaddingBytes1 = 4;
   int packet_size = 0;
   {
     QuicFrames frames;
     frames.push_back(frame);
     char buffer[kMaxPacketSize];
     PendingRetransmission retransmission(CreateRetransmission(
         frames, false /* has_crypto_handshake */,
         kNumPaddingBytes1 /* padding bytes */, ENCRYPTION_NONE,
-        QuicPacketCreatorPeer::NextPacketNumberLength(&creator_)));
+        FLAGS_quic_simple_packet_number_length
+            ? QuicPacketCreatorPeer::GetPacketNumberLength(&creator_)
+            : QuicPacketCreatorPeer::NextPacketNumberLength(&creator_)));
     EXPECT_CALL(delegate_, OnSerializedPacket(_))
         .WillOnce(Invoke(this, &QuicPacketCreatorTest::SaveSerializedPacket));
     creator_.ReserializeAllFrames(retransmission, buffer, kMaxPacketSize);
     packet_size = serialized_packet_.encrypted_length;
   }
 
   const int kNumPaddingBytes2 = 44;
   QuicFrames frames;
   frames.push_back(frame);
   char buffer[kMaxPacketSize];
@@ skipping 238 matching lines @@
   {
     InSequence s;
     EXPECT_CALL(framer_visitor_, OnPacket());
     EXPECT_CALL(framer_visitor_, OnUnauthenticatedPublicHeader(_));
     EXPECT_CALL(framer_visitor_, OnVersionNegotiationPacket(_));
   }
   QuicFramerPeer::SetPerspective(&client_framer_, Perspective::IS_CLIENT);
   client_framer_.ProcessPacket(*encrypted);
 }
 
-TEST_P(QuicPacketCreatorTest, UpdatePacketSequenceNumberLengthLeastAwaiting) {
+TEST_P(QuicPacketCreatorTest, UpdatePacketNumberLengthLeastAwaiting_Old) {
+  FLAGS_quic_simple_packet_number_length = false;
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64);
   creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64 * 256);
   creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_2BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64 * 256 * 256);
   creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   QuicPacketCreatorPeer::SetPacketNumber(&creator_,
                                          UINT64_C(64) * 256 * 256 * 256 * 256);
   creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_6BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 }
 
-TEST_P(QuicPacketCreatorTest, UpdatePacketSequenceNumberLengthBandwidth) {
+TEST_P(QuicPacketCreatorTest, UpdatePacketSequenceNumberLengthBandwidth_old) {
+  FLAGS_quic_simple_packet_number_length = false;
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   creator_.UpdatePacketNumberLength(1, 10000 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   creator_.UpdatePacketNumberLength(1, 10000 * 256 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_2BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   creator_.UpdatePacketNumberLength(1,
                                     10000 * 256 * 256 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 
   creator_.UpdatePacketNumberLength(
       1, UINT64_C(1000) * 256 * 256 * 256 * 256 / kDefaultMaxPacketSize);
   EXPECT_EQ(PACKET_6BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
 }
 
+TEST_P(QuicPacketCreatorTest, UpdatePacketSequenceNumberLengthLeastAwaiting) {
+  FLAGS_quic_simple_packet_number_length = true;
+  EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64);
+  creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64 * 256);
+  creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_2BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64 * 256 * 256);
+  creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  QuicPacketCreatorPeer::SetPacketNumber(&creator_,
+                                         UINT64_C(64) * 256 * 256 * 256 * 256);
+  creator_.UpdatePacketNumberLength(2, 10000 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_6BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+}
+
+TEST_P(QuicPacketCreatorTest, UpdatePacketSequenceNumberLengthCwnd) {
+  FLAGS_quic_simple_packet_number_length = true;
+  EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  creator_.UpdatePacketNumberLength(1, 10000 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  creator_.UpdatePacketNumberLength(1, 10000 * 256 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_2BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  creator_.UpdatePacketNumberLength(1,
+                                    10000 * 256 * 256 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_4BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+
+  creator_.UpdatePacketNumberLength(
+      1, UINT64_C(1000) * 256 * 256 * 256 * 256 / kDefaultMaxPacketSize);
+  EXPECT_EQ(PACKET_6BYTE_PACKET_NUMBER,
+            QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
+}
+
 TEST_P(QuicPacketCreatorTest, SerializeFrame) {
   if (!GetParam().version_serialization) {
     creator_.StopSendingVersion();
   }
   frames_.push_back(
       QuicFrame(new QuicStreamFrame(0u, false, 0u, StringPiece())));
   SerializedPacket serialized = SerializeAllFrames(frames_);
   delete frames_[0].stream_frame;
 
   QuicPacketHeader header;
@@ skipping 288 matching lines @@
   creator_.SetCurrentPath(kDefaultPathId, 2, 0);
   EXPECT_EQ(kDefaultPathId, QuicPacketCreatorPeer::GetCurrentPath(&creator_));
   EXPECT_TRUE(creator_.HasPendingFrames());
   EXPECT_EQ(1u, creator_.packet_number());
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
 }
 
 TEST_P(QuicPacketCreatorTest,
        SetCurrentPathAndUpdatePacketSequenceNumberLength) {
+  FLAGS_quic_simple_packet_number_length = false;
   // Current path is the default path.
   EXPECT_EQ(kDefaultPathId, QuicPacketCreatorPeer::GetCurrentPath(&creator_));
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::GetPacketNumberLength(&creator_));
   EXPECT_EQ(PACKET_1BYTE_PACKET_NUMBER,
             QuicPacketCreatorPeer::NextPacketNumberLength(&creator_));
   QuicPacketCreatorPeer::SetPacketNumber(&creator_, 64 * 256 - 2);
   // Add a stream frame to the creator and send the packet.
   QuicFrame frame;
   QuicIOVector io_vector(MakeIOVector("test"));
@@ skipping 93 matching lines @@
   EXPECT_CALL(delegate_,
               OnUnrecoverableError(QUIC_CRYPTO_CHLO_TOO_LARGE, _, _));
   EXPECT_DFATAL(
       creator_.ConsumeData(1u, data_iovec, 0u, 0u, false, false, &frame),
       "Client hello won't fit in a single packet.");
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net