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// 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 here to guarantee this header gets included (for MSG_WAITFORONE)
// regardless of how the below transitive header include set may change.
#include <sys/socket.h>
#include "base/macros.h"
#include "net/quic/core/quic_packets.h"
#include "net/quic/platform/api/quic_clock.h"
#include "net/quic/platform/api/quic_socket_address.h"
#include "net/tools/quic/platform/impl/quic_socket_utils.h"
#include "net/tools/quic/quic_process_packet_interface.h"
#define MMSG_MORE 0
namespace net {
#if MMSG_MORE
// Read in larger batches to minimize recvmmsg overhead.
const int kNumPacketsPerReadMmsgCall = 16;
#endif
class QuicPacketReader {
public:
QuicPacketReader();
virtual ~QuicPacketReader();
// Reads a number of packets from the given fd, and then passes them off to
// the PacketProcessInterface. Returns true if there may be additional
// packets available on the socket.
// Populates |packets_dropped| if it is non-null and the socket is configured
// to track dropped packets and some packets are read.
// If the socket has timestamping enabled, the per packet timestamps will be
// passed to the processor. Otherwise, |clock| will be used.
virtual bool ReadAndDispatchPackets(int fd,
int port,
const QuicClock& clock,
ProcessPacketInterface* processor,
QuicPacketCount* packets_dropped);
private:
// Initialize the internal state of the reader.
void Initialize();
// Reads and dispatches many packets using recvmmsg.
bool ReadAndDispatchManyPackets(int fd,
int port,
const QuicClock& clock,
ProcessPacketInterface* processor,
QuicPacketCount* packets_dropped);
// Reads and dispatches a single packet using recvmsg.
static bool ReadAndDispatchSinglePacket(int fd,
int port,
const QuicClock& clock,
ProcessPacketInterface* processor,
QuicPacketCount* packets_dropped);
// Storage only used when recvmmsg is available.
#if MMSG_MORE
// TODO(danzh): change it to be a pointer to avoid the allocation on the stack
// from exceeding maximum allowed frame size.
// packets_ and mmsg_hdr_ are used to supply cbuf and buf to the recvmmsg
// call.
struct PacketData {
iovec iov;
// raw_address is used for address information provided by the recvmmsg
// call on the packets.
struct sockaddr_storage raw_address;
// cbuf is used for ancillary data from the kernel on recvmmsg.
char cbuf[QuicSocketUtils::kSpaceForCmsg];
// buf is used for the data read from the kernel on recvmmsg.
char buf[kMaxPacketSize];
};
PacketData packets_[kNumPacketsPerReadMmsgCall];
mmsghdr mmsg_hdr_[kNumPacketsPerReadMmsgCall];
#endif
DISALLOW_COPY_AND_ASSIGN(QuicPacketReader);
};
} // namespace net
#endif // NET_TOOLS_QUIC_QUIC_PACKET_READER_H_