Move all the packet parsing logic into QuicDispatcher from the

net/tools/quic/quic_dispatcher.cc

Index: net/tools/quic/quic_dispatcher.cc
diff --git a/net/tools/quic/quic_dispatcher.cc b/net/tools/quic/quic_dispatcher.cc
index 297234d9755b176210acaa50cb2b3a75fe315c8c..21070169a979d8e1f082f78bdddc1637be4db411 100644
--- a/net/tools/quic/quic_dispatcher.cc
+++ b/net/tools/quic/quic_dispatcher.cc
@@ -17,6 +17,7 @@
 namespace net {
 namespace tools {
 
+using base::StringPiece;
 using std::make_pair;
 
 class DeleteSessionsAlarm : public EpollAlarm {
@@ -35,6 +36,90 @@ class DeleteSessionsAlarm : public EpollAlarm {
   QuicDispatcher* dispatcher_;
 };
 
+class QuicDispatcher::QuicFramerVisitor : public QuicFramerVisitorInterface {
+ public:
+  explicit QuicFramerVisitor(QuicDispatcher* dispatcher)
+      : dispatcher_(dispatcher) {
+  }
+
+  // QuicFramerVisitorInterface implementation
+  virtual void OnPacket() OVERRIDE {}
+  virtual bool OnUnauthenticatedPublicHeader(
+      const QuicPacketPublicHeader& header) OVERRIDE {
+    return dispatcher_->OnUnauthenticatedPublicHeader(header);
+  }
+  virtual bool OnUnauthenticatedHeader(
+      const QuicPacketHeader& header) OVERRIDE {
+    dispatcher_->OnUnauthenticatedHeader(header);
+    return false;
+  }
+  virtual void OnError(QuicFramer* framer) OVERRIDE {
+    DLOG(INFO) << QuicUtils::ErrorToString(framer->error());
+  }
+
+  // The following methods should never get called because we always return
+  // false from OnUnauthenticatedHeader().  As a result, we never process the
+  // payload of the packet.
+  virtual bool OnProtocolVersionMismatch(
+      QuicVersion /*received_version*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual void OnPublicResetPacket(
+      const QuicPublicResetPacket& /*packet*/) OVERRIDE {
+    DCHECK(false);
+  }
+  virtual void OnVersionNegotiationPacket(
+      const QuicVersionNegotiationPacket& /*packet*/) OVERRIDE {
+    DCHECK(false);
+  }
+  virtual void OnPacketComplete() OVERRIDE {
+    DCHECK(false);
+  }
+  virtual bool OnPacketHeader(const QuicPacketHeader& /*header*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual void OnRevivedPacket() OVERRIDE {
+    DCHECK(false);
+  }
+  virtual void OnFecProtectedPayload(StringPiece /*payload*/) OVERRIDE {
+    DCHECK(false);
+  }
+  virtual bool OnStreamFrame(const QuicStreamFrame& /*frame*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual bool OnAckFrame(const QuicAckFrame& /*frame*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual bool OnCongestionFeedbackFrame(
+      const QuicCongestionFeedbackFrame& /*frame*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual bool OnRstStreamFrame(const QuicRstStreamFrame& /*frame*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual bool OnConnectionCloseFrame(
+      const QuicConnectionCloseFrame & /*frame*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual bool OnGoAwayFrame(const QuicGoAwayFrame& /*frame*/) OVERRIDE {
+    DCHECK(false);
+    return false;
+  }
+  virtual void OnFecData(const QuicFecData& /*fec*/) OVERRIDE {
+    DCHECK(false);
+  }
+
+ private:
+  QuicDispatcher* dispatcher_;
+};
+
 QuicDispatcher::QuicDispatcher(const QuicConfig& config,
                                const QuicCryptoServerConfig& crypto_config,
                                const QuicVersionVector& supported_versions,
@@ -50,7 +135,11 @@ QuicDispatcher::QuicDispatcher(const QuicConfig& config,
       write_blocked_(false),
       helper_(new QuicEpollConnectionHelper(epoll_server_)),
       writer_(new QuicDefaultPacketWriter(fd)),
-      supported_versions_(supported_versions) {
+      supported_versions_(supported_versions),
+      current_packet_(NULL),
+      framer_(supported_versions, /*unused*/ QuicTime::Zero(), true),
+      framer_visitor_(new QuicFramerVisitor(this)) {
+  framer_.set_visitor(framer_visitor_.get());
 }
 
 QuicDispatcher::~QuicDispatcher() {
@@ -87,41 +176,56 @@ bool QuicDispatcher::IsWriteBlockedDataBuffered() const {
 
 void QuicDispatcher::ProcessPacket(const IPEndPoint& server_address,
                                    const IPEndPoint& client_address,
-                                   QuicGuid guid,
-                                   bool has_version_flag,
                                    const QuicEncryptedPacket& packet) {
+  current_server_address_ = server_address;
+  current_client_address_ = client_address;
+  current_packet_ = &packet;
+  // ProcessPacket will cause the packet to be dispatched in
+  // OnUnauthenticatedPublicHeader, or sent to the time wait list manager
+  // in OnAuthenticatedHeader.
+  framer_.ProcessPacket(packet);
+  // TODO(rjshade): Return a status describing if/why a packet was dropped,
+  //                and log somehow.  Maybe expose as a varz.
+}
+
+bool QuicDispatcher::OnUnauthenticatedPublicHeader(
+    const QuicPacketPublicHeader& header) {
   QuicSession* session = NULL;
 
+  QuicGuid guid = header.guid;
   SessionMap::iterator it = session_map_.find(guid);
   if (it == session_map_.end()) {
+    if (header.reset_flag) {
+      return false;
+    }
     if (time_wait_list_manager_->IsGuidInTimeWait(guid)) {
-      time_wait_list_manager_->ProcessPacket(server_address,
-                                             client_address,
-                                             guid,
-                                             packet);
-      return;
+      return HandlePacketForTimeWait(header);
     }
 
     // Ensure the packet has a version negotiation bit set before creating a new
     // session for it.  All initial packets for a new connection are required to
     // have the flag set.  Otherwise it may be a stray packet.
-    if (has_version_flag) {
-      session = CreateQuicSession(guid, server_address, client_address);
+    if (header.version_flag) {
+      session = CreateQuicSession(guid, current_server_address_,
+                                  current_client_address_);
     }
 
     if (session == NULL) {
       DLOG(INFO) << "Failed to create session for " << guid;
       // Add this guid fo the time-wait state, to safely reject future packets.
-      // We don't know the version here, so assume latest.
-      // TODO(ianswett): Produce a no-version version negotiation packet.
-      time_wait_list_manager_->AddGuidToTimeWait(guid,
-                                                 supported_versions_.front(),
-                                                 NULL);
-      time_wait_list_manager_->ProcessPacket(server_address,
-                                             client_address,
-                                             guid,
-                                             packet);
-      return;
+
+      if (header.version_flag &&
+          !framer_.IsSupportedVersion(header.versions.front())) {
+        // TODO(ianswett): Produce a no-version version negotiation packet.
+        return false;
+      }
+
+      // Use the version in the packet if possible, otherwise assume the latest.
+      QuicVersion version = header.version_flag ? header.versions.front() :
+          supported_versions_.front();
+      time_wait_list_manager_->AddGuidToTimeWait(guid, version, NULL);
+      DCHECK(time_wait_list_manager_->IsGuidInTimeWait(guid));
+      return HandlePacketForTimeWait(header);
     }
     DLOG(INFO) << "Created new session for " << guid;
     session_map_.insert(make_pair(guid, session));
@@ -130,7 +234,18 @@ void QuicDispatcher::ProcessPacket(const IPEndPoint& server_address,
   }
 
   session->connection()->ProcessUdpPacket(
-      server_address, client_address, packet);
+      current_server_address_, current_client_address_, *current_packet_);
+
+  // Do not parse the packet further.  The session will process it completely.
+  return false;
+}
+
+void QuicDispatcher::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
+  DCHECK(time_wait_list_manager_->IsGuidInTimeWait(header.public_header.guid));
+  time_wait_list_manager_->ProcessPacket(current_server_address_,
+                                         current_client_address_,
+                                         header.public_header.guid,
+                                         header.packet_sequence_number);
 }
 
 void QuicDispatcher::CleanUpSession(SessionMap::iterator it) {
@@ -223,5 +338,22 @@ QuicSession* QuicDispatcher::CreateQuicSession(
   return session;
 }
 
+bool QuicDispatcher::HandlePacketForTimeWait(
+    const QuicPacketPublicHeader& header) {
+  if (header.reset_flag) {
+    // Public reset packets do not have sequence numbers, so ignore the packet.
+    return false;
+  }
+
+  // Switch the framer to the correct version, so that the sequence number can
+  // be parsed correctly.
+  framer_.set_version(time_wait_list_manager_->GetQuicVersionFromGuid(
+      header.guid));
+
+  // Continue parsing the packet to extract the sequence number.  Then
+  // send it to the time wait manager in OnUnathenticatedHeader.
+  return true;
+}
+
 }  // namespace tools
 }  // namespace net