Clear reserved flags on synthetic continuations.

Previously when WebSocketBasicStream split a frame that arrived in
several chunks, it would copy the reserved bits from the first frame
onto all subsequent frames.

However, the permessage-deflate extension requires that the RSV1 bit
only be set on the first frame of the message.

For compatability with permessage-deflate, clear the reserved bits on
second and subsequent frames when splitting a frame.

BUG=343507
TEST=net_unittests --gtest_filter=WebSocket*

Review URL: https://codereview.chromium.org/171883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252000 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 36 insertions, 2 deletions

diff --git a/net/websockets/websocket_basic_stream.cc b/net/websockets/websocket_basic_stream.cc
index 8d1fa87..fd2766b 100644
--- a/net/websockets/websocket_basic_stream.cc
+++ b/net/websockets/websocket_basic_stream.cc
@@ -378,9 +378,16 @@ scoped_ptr<WebSocketFrame> WebSocketBasicStream::CreateFrame(
     result_frame->header.payload_length = data_size;
     result_frame->data = data;
     // Ensure that opcodes Text and Binary are only used for the first frame in
-    // the message.
-    if (WebSocketFrameHeader::IsKnownDataOpCode(opcode))
+    // the message. Also clear the reserved bits.
+    // TODO(ricea): If a future extension requires the reserved bits to be
+    // retained on continuation frames, make this behaviour conditional on a
+    // flag set at construction time.
+    if (!is_final_chunk && WebSocketFrameHeader::IsKnownDataOpCode(opcode)) {
       current_frame_header_->opcode = WebSocketFrameHeader::kOpCodeContinuation;
+      current_frame_header_->reserved1 = false;
+      current_frame_header_->reserved2 = false;
+      current_frame_header_->reserved3 = false;
+    }
   }
   // Make sure that a frame header is not applied to any chunks that do not
   // belong to it.
diff --git a/net/websockets/websocket_basic_stream_test.cc b/net/websockets/websocket_basic_stream_test.cc
index 85f6156..4dcb8e2 100644
--- a/net/websockets/websocket_basic_stream_test.cc
+++ b/net/websockets/websocket_basic_stream_test.cc
@@ -828,6 +828,33 @@ TEST_F(WebSocketBasicStreamSocketChunkedReadTest, OneMegFrame) {
   }
 }
 
+// A frame with reserved flag(s) set that arrives in chunks should only have the
+// reserved flag(s) set on the first chunk when split.
+TEST_F(WebSocketBasicStreamSocketChunkedReadTest, ReservedFlagCleared) {
+  static const char kReservedFlagFrame[] = "\x41\x05Hello";
+  const size_t kReservedFlagFrameSize = arraysize(kReservedFlagFrame) - 1;
+  const size_t kChunkSize = 5;
+
+  CreateChunkedRead(ASYNC,
+                    kReservedFlagFrame,
+                    kReservedFlagFrameSize,
+                    kChunkSize,
+                    2,
+                    LAST_FRAME_BIG);
+
+  TestCompletionCallback cb[2];
+  ASSERT_EQ(ERR_IO_PENDING, stream_->ReadFrames(&frames_, cb[0].callback()));
+  EXPECT_EQ(OK, cb[0].WaitForResult());
+  ASSERT_EQ(1U, frames_.size());
+  EXPECT_TRUE(frames_[0]->header.reserved1);
+
+  frames_.clear();
+  ASSERT_EQ(ERR_IO_PENDING, stream_->ReadFrames(&frames_, cb[1].callback()));
+  EXPECT_EQ(OK, cb[1].WaitForResult());
+  ASSERT_EQ(1U, frames_.size());
+  EXPECT_FALSE(frames_[0]->header.reserved1);
+}
+
 // Check that writing a frame all at once works.
 TEST_F(WebSocketBasicStreamSocketWriteTest, WriteAtOnce) {
   MockWrite writes[] = {MockWrite(SYNCHRONOUS, kWriteFrame, kWriteFrameSize)};