net/tools/quic/quic_packet_reader.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // A class to read incoming QUIC packets from the UDP socket.
   6
   7 #ifndef NET_TOOLS_QUIC_QUIC_PACKET_READER_H_
   8 #define NET_TOOLS_QUIC_QUIC_PACKET_READER_H_
   9
  10 #include <netinet/in.h>
  11 #include <sys/socket.h>
  12
  13 #include "base/basictypes.h"
  14 #include "net/quic/quic_protocol.h"
  15
  16 namespace net {
  17
  18 namespace tools {
  19
  20 // Read in larger batches to minimize recvmmsg overhead.
  21 const int kNumPacketsPerReadMmsgCall = 16;
  22 // Allocate space for in6_pktinfo as it's larger than in_pktinfo
  23 const int kSpaceForOverflowAndIp =
  24     CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(in6_pktinfo));
  25
  26 namespace test {
  27 class QuicServerPeer;
  28 }  // namespace test
  29
  30 class ProcessPacketInterface;
  31 class QuicDispatcher;
  32
  33 class QuicPacketReader {
  34  public:
  35   QuicPacketReader();
  36
  37   ~QuicPacketReader();
  38
  39   // Reads a number of packets from the given fd, and then passes them off to
  40   // the PacketProcessInterface.  Returns true if at least 1 packet is read,
  41   // false otherwise.
  42   // Populates |packets_dropped| if it is non-null and the socket is configured
  43   // to track dropped packets and some packets are read.
  44   bool ReadAndDispatchPackets(int fd,
  45                               int port,
  46                               ProcessPacketInterface* processor,
  47                               QuicPacketCount* packets_dropped);
  48
  49   // Same as ReadAndDispatchPackets, only does one packet at a time.
  50   static bool ReadAndDispatchSinglePacket(int fd,
  51                                           int port,
  52                                           ProcessPacketInterface* processor,
  53                                           QuicPacketCount* packets_dropped);
  54
  55  private:
  56   // Initialize the internal state of the reader.
  57   void Initialize();
  58
  59   // Storage only used when recvmmsg is available.
  60
  61   // cbuf_ is used for ancillary data from the kernel on recvmmsg.
  62   char cbuf_[kSpaceForOverflowAndIp * kNumPacketsPerReadMmsgCall];
  63   // buf_ is used for the data read from the kernel on recvmmsg.
  64   char buf_[2 * kMaxPacketSize * kNumPacketsPerReadMmsgCall];
  65   // iov_ and mmsg_hdr_ are used to supply cbuf and buf to the recvmmsg call.
  66   iovec iov_[kNumPacketsPerReadMmsgCall];
  67   mmsghdr mmsg_hdr_[kNumPacketsPerReadMmsgCall];
  68   // raw_address_ is used for address information provided by the recvmmsg
  69   // call on the packets.
  70   struct sockaddr_storage raw_address_[kNumPacketsPerReadMmsgCall];
  71
  72   DISALLOW_COPY_AND_ASSIGN(QuicPacketReader);
  73 };
  74
  75 }  // namespace tools
  76 }  // namespace net
  77
  78 #endif  // NET_TOOLS_QUIC_QUIC_PACKET_READER_H_