Land Recent QUIC Changes until 03/15/2015.

net/tools/quic/quic_packet_reader.h

+// Copyright 2015 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.
+
+// A class to read incoming QUIC packets from the UDP socket.
+
+#ifndef NET_TOOLS_QUIC_QUIC_PACKET_READER_H_
+#define NET_TOOLS_QUIC_QUIC_PACKET_READER_H_
+
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "base/basictypes.h"
+#include "net/quic/quic_protocol.h"
+
+namespace net {
+
+namespace tools {
+
+// Read in larger batches to minimize recvmmsg overhead.
+const int kNumPacketsPerReadMmsgCall = 16;
+// Allocate space for in6_pktinfo as it's larger than in_pktinfo
+const int kSpaceForOverflowAndIp =
+    CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(in6_pktinfo));
+
+namespace test {
+class QuicServerPeer;
+}  // namespace test
+
+class ProcessPacketInterface;
+class QuicDispatcher;
+
+class QuicPacketReader {
+ public:
+  QuicPacketReader();
+
+  ~QuicPacketReader();
+
+  // Reads a number of packets from the given fd, and then passes them off to
+  // the PacketProcessInterface.  Returns true if at least 1 packet is read,
+  // false otherwise.
+  // Populates |packets_dropped| if it is non-null and the socket is configured
+  // to track dropped packets and some packets are read.
+  bool ReadAndDispatchPackets(int fd,
+                              int port,
+                              ProcessPacketInterface* processor,
+                              QuicPacketCount* packets_dropped);
+
+  // Same as ReadAndDispatchPackets, only does one packet at a time.
+  static bool ReadAndDispatchSinglePacket(int fd,
+                                          int port,
+                                          ProcessPacketInterface* processor,
+                                          QuicPacketCount* packets_dropped);
+
+ private:
+  // Initialize the internal state of the reader.
+  void Initialize();
+
+  // Storage only used when recvmmsg is available.
+
+  // cbuf_ is used for ancillary data from the kernel on recvmmsg.
+  char cbuf_[kSpaceForOverflowAndIp * kNumPacketsPerReadMmsgCall];
+  // buf_ is used for the data read from the kernel on recvmmsg.
+  char buf_[2 * kMaxPacketSize * kNumPacketsPerReadMmsgCall];
+  // iov_ and mmsg_hdr_ are used to supply cbuf and buf to the recvmmsg call.
+  iovec iov_[kNumPacketsPerReadMmsgCall];
+  mmsghdr mmsg_hdr_[kNumPacketsPerReadMmsgCall];
+  // raw_address_ is used for address information provided by the recvmmsg
+  // call on the packets.
+  struct sockaddr_storage raw_address_[kNumPacketsPerReadMmsgCall];
+
+  DISALLOW_COPY_AND_ASSIGN(QuicPacketReader);
+};
+
+}  // namespace tools
+}  // namespace net
+
+#endif  // NET_TOOLS_QUIC_QUIC_PACKET_READER_H_