Fix crash in WriteSocket() when sending Settings frames

and compression is enabled.

We need better unit tests for the compressed-frame testing.  Filed
bug 41805 to implement those.


BUG=41803
TEST=NONE

Review URL: http://codereview.chromium.org/1648014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@44819 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 28 insertions, 1 deletions

diff --git a/net/spdy/spdy_framer.cc b/net/spdy/spdy_framer.cc
index 65ef2e5..dc1f856 100644
--- a/net/spdy/spdy_framer.cc
+++ b/net/spdy/spdy_framer.cc
@@ -888,6 +888,24 @@ SpdyFrame* SpdyFramer::DuplicateFrame(const SpdyFrame* frame) {
   return new_frame;
 }
 
+bool SpdyFramer::IsCompressible(const SpdyFrame* frame) const {
+  // The important frames to compress are those which contain large
+  // amounts of compressible data - namely the headers in the SYN_STREAM
+  // and SYN_REPLY.
+  // TODO(mbelshe): Reconcile this with the spec when the spec is
+  // explicit about which frames compress and which do not.
+  if (frame->is_control_frame()) {
+    const SpdyControlFrame* control_frame =
+        reinterpret_cast<const SpdyControlFrame*>(frame);
+    return control_frame->type() == SYN_STREAM ||
+           control_frame->type() == SYN_REPLY;
+  }
+
+  const SpdyDataFrame* data_frame =
+      reinterpret_cast<const SpdyDataFrame*>(frame);
+  return (data_frame->flags() & DATA_FLAG_COMPRESSED) != 0;
+}
+
 void SpdyFramer::set_enable_compression(bool value) {
   enable_compression_ = value;
 }
diff --git a/net/spdy/spdy_framer.h b/net/spdy/spdy_framer.h
index c265be9..b07dd02 100644
--- a/net/spdy/spdy_framer.h
+++ b/net/spdy/spdy_framer.h
@@ -223,6 +223,9 @@ class SpdyFramer {
   // Returned frame must be freed with "delete".
   SpdyFrame* DuplicateFrame(const SpdyFrame* frame);
 
+  // Returns true if a frame could be compressed.
+  bool IsCompressible(const SpdyFrame* frame) const;
+
   // For debugging.
   static const char* StateToString(int state);
   static const char* ErrorCodeToString(int error_code);
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 1ab3904..8d6d9d2 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -685,9 +685,15 @@ void SpdySession::WriteSocket() {
       // which is now.  At this time, we don't compress our data frames.
       spdy::SpdyFrame uncompressed_frame(next_buffer.buffer()->data(), false);
       size_t size;
-      if (uncompressed_frame.is_control_frame()) {
+      if (spdy_framer_.IsCompressible(&uncompressed_frame)) {
         scoped_ptr<spdy::SpdyFrame> compressed_frame(
             spdy_framer_.CompressFrame(&uncompressed_frame));
+        if (!compressed_frame.get()) {
+          LOG(ERROR) << "SPDY Compression failure";
+          CloseSessionOnError(net::ERR_SPDY_PROTOCOL_ERROR);
+          return;
+        }
+
         size = compressed_frame->length() + spdy::SpdyFrame::size();
 
         DCHECK(size > 0);