243 lines
7.3 KiB
C++
243 lines
7.3 KiB
C++
/*
|
|
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
|
|
#ifndef WEBRTC_P2P_BASE_PSEUDOTCP_H_
|
|
#define WEBRTC_P2P_BASE_PSEUDOTCP_H_
|
|
|
|
#include <list>
|
|
|
|
#include "webrtc/base/basictypes.h"
|
|
#include "webrtc/base/stream.h"
|
|
|
|
namespace cricket {
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
// IPseudoTcpNotify
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
class PseudoTcp;
|
|
|
|
class IPseudoTcpNotify {
|
|
public:
|
|
// Notification of tcp events
|
|
virtual void OnTcpOpen(PseudoTcp* tcp) = 0;
|
|
virtual void OnTcpReadable(PseudoTcp* tcp) = 0;
|
|
virtual void OnTcpWriteable(PseudoTcp* tcp) = 0;
|
|
virtual void OnTcpClosed(PseudoTcp* tcp, uint32_t error) = 0;
|
|
|
|
// Write the packet onto the network
|
|
enum WriteResult { WR_SUCCESS, WR_TOO_LARGE, WR_FAIL };
|
|
virtual WriteResult TcpWritePacket(PseudoTcp* tcp,
|
|
const char* buffer, size_t len) = 0;
|
|
|
|
protected:
|
|
virtual ~IPseudoTcpNotify() {}
|
|
};
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
// PseudoTcp
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
class PseudoTcp {
|
|
public:
|
|
static uint32_t Now();
|
|
|
|
PseudoTcp(IPseudoTcpNotify* notify, uint32_t conv);
|
|
virtual ~PseudoTcp();
|
|
|
|
int Connect();
|
|
int Recv(char* buffer, size_t len);
|
|
int Send(const char* buffer, size_t len);
|
|
void Close(bool force);
|
|
int GetError();
|
|
|
|
enum TcpState {
|
|
TCP_LISTEN, TCP_SYN_SENT, TCP_SYN_RECEIVED, TCP_ESTABLISHED, TCP_CLOSED
|
|
};
|
|
TcpState State() const { return m_state; }
|
|
|
|
// Call this when the PMTU changes.
|
|
void NotifyMTU(uint16_t mtu);
|
|
|
|
// Call this based on timeout value returned from GetNextClock.
|
|
// It's ok to call this too frequently.
|
|
void NotifyClock(uint32_t now);
|
|
|
|
// Call this whenever a packet arrives.
|
|
// Returns true if the packet was processed successfully.
|
|
bool NotifyPacket(const char * buffer, size_t len);
|
|
|
|
// Call this to determine the next time NotifyClock should be called.
|
|
// Returns false if the socket is ready to be destroyed.
|
|
bool GetNextClock(uint32_t now, long& timeout);
|
|
|
|
// Call these to get/set option values to tailor this PseudoTcp
|
|
// instance's behaviour for the kind of data it will carry.
|
|
// If an unrecognized option is set or got, an assertion will fire.
|
|
//
|
|
// Setting options for OPT_RCVBUF or OPT_SNDBUF after Connect() is called
|
|
// will result in an assertion.
|
|
enum Option {
|
|
OPT_NODELAY, // Whether to enable Nagle's algorithm (0 == off)
|
|
OPT_ACKDELAY, // The Delayed ACK timeout (0 == off).
|
|
OPT_RCVBUF, // Set the receive buffer size, in bytes.
|
|
OPT_SNDBUF, // Set the send buffer size, in bytes.
|
|
};
|
|
void GetOption(Option opt, int* value);
|
|
void SetOption(Option opt, int value);
|
|
|
|
// Returns current congestion window in bytes.
|
|
uint32_t GetCongestionWindow() const;
|
|
|
|
// Returns amount of data in bytes that has been sent, but haven't
|
|
// been acknowledged.
|
|
uint32_t GetBytesInFlight() const;
|
|
|
|
// Returns number of bytes that were written in buffer and haven't
|
|
// been sent.
|
|
uint32_t GetBytesBufferedNotSent() const;
|
|
|
|
// Returns current round-trip time estimate in milliseconds.
|
|
uint32_t GetRoundTripTimeEstimateMs() const;
|
|
|
|
protected:
|
|
enum SendFlags { sfNone, sfDelayedAck, sfImmediateAck };
|
|
|
|
struct Segment {
|
|
uint32_t conv, seq, ack;
|
|
uint8_t flags;
|
|
uint16_t wnd;
|
|
const char * data;
|
|
uint32_t len;
|
|
uint32_t tsval, tsecr;
|
|
};
|
|
|
|
struct SSegment {
|
|
SSegment(uint32_t s, uint32_t l, bool c)
|
|
: seq(s), len(l), /*tstamp(0),*/ xmit(0), bCtrl(c) {}
|
|
uint32_t seq, len;
|
|
// uint32_t tstamp;
|
|
uint8_t xmit;
|
|
bool bCtrl;
|
|
};
|
|
typedef std::list<SSegment> SList;
|
|
|
|
struct RSegment {
|
|
uint32_t seq, len;
|
|
};
|
|
|
|
uint32_t queue(const char* data, uint32_t len, bool bCtrl);
|
|
|
|
// Creates a packet and submits it to the network. This method can either
|
|
// send payload or just an ACK packet.
|
|
//
|
|
// |seq| is the sequence number of this packet.
|
|
// |flags| is the flags for sending this packet.
|
|
// |offset| is the offset to read from |m_sbuf|.
|
|
// |len| is the number of bytes to read from |m_sbuf| as payload. If this
|
|
// value is 0 then this is an ACK packet, otherwise this packet has payload.
|
|
IPseudoTcpNotify::WriteResult packet(uint32_t seq,
|
|
uint8_t flags,
|
|
uint32_t offset,
|
|
uint32_t len);
|
|
bool parse(const uint8_t* buffer, uint32_t size);
|
|
|
|
void attemptSend(SendFlags sflags = sfNone);
|
|
|
|
void closedown(uint32_t err = 0);
|
|
|
|
bool clock_check(uint32_t now, long& nTimeout);
|
|
|
|
bool process(Segment& seg);
|
|
bool transmit(const SList::iterator& seg, uint32_t now);
|
|
|
|
void adjustMTU();
|
|
|
|
protected:
|
|
// This method is used in test only to query receive buffer state.
|
|
bool isReceiveBufferFull() const;
|
|
|
|
// This method is only used in tests, to disable window scaling
|
|
// support for testing backward compatibility.
|
|
void disableWindowScale();
|
|
|
|
private:
|
|
// Queue the connect message with TCP options.
|
|
void queueConnectMessage();
|
|
|
|
// Parse TCP options in the header.
|
|
void parseOptions(const char* data, uint32_t len);
|
|
|
|
// Apply a TCP option that has been read from the header.
|
|
void applyOption(char kind, const char* data, uint32_t len);
|
|
|
|
// Apply window scale option.
|
|
void applyWindowScaleOption(uint8_t scale_factor);
|
|
|
|
// Resize the send buffer with |new_size| in bytes.
|
|
void resizeSendBuffer(uint32_t new_size);
|
|
|
|
// Resize the receive buffer with |new_size| in bytes. This call adjusts
|
|
// window scale factor |m_swnd_scale| accordingly.
|
|
void resizeReceiveBuffer(uint32_t new_size);
|
|
|
|
IPseudoTcpNotify* m_notify;
|
|
enum Shutdown { SD_NONE, SD_GRACEFUL, SD_FORCEFUL } m_shutdown;
|
|
int m_error;
|
|
|
|
// TCB data
|
|
TcpState m_state;
|
|
uint32_t m_conv;
|
|
bool m_bReadEnable, m_bWriteEnable, m_bOutgoing;
|
|
uint32_t m_lasttraffic;
|
|
|
|
// Incoming data
|
|
typedef std::list<RSegment> RList;
|
|
RList m_rlist;
|
|
uint32_t m_rbuf_len, m_rcv_nxt, m_rcv_wnd, m_lastrecv;
|
|
uint8_t m_rwnd_scale; // Window scale factor.
|
|
rtc::FifoBuffer m_rbuf;
|
|
|
|
// Outgoing data
|
|
SList m_slist;
|
|
uint32_t m_sbuf_len, m_snd_nxt, m_snd_wnd, m_lastsend, m_snd_una;
|
|
uint8_t m_swnd_scale; // Window scale factor.
|
|
rtc::FifoBuffer m_sbuf;
|
|
|
|
// Maximum segment size, estimated protocol level, largest segment sent
|
|
uint32_t m_mss, m_msslevel, m_largest, m_mtu_advise;
|
|
// Retransmit timer
|
|
uint32_t m_rto_base;
|
|
|
|
// Timestamp tracking
|
|
uint32_t m_ts_recent, m_ts_lastack;
|
|
|
|
// Round-trip calculation
|
|
uint32_t m_rx_rttvar, m_rx_srtt, m_rx_rto;
|
|
|
|
// Congestion avoidance, Fast retransmit/recovery, Delayed ACKs
|
|
uint32_t m_ssthresh, m_cwnd;
|
|
uint8_t m_dup_acks;
|
|
uint32_t m_recover;
|
|
uint32_t m_t_ack;
|
|
|
|
// Configuration options
|
|
bool m_use_nagling;
|
|
uint32_t m_ack_delay;
|
|
|
|
// This is used by unit tests to test backward compatibility of
|
|
// PseudoTcp implementations that don't support window scaling.
|
|
bool m_support_wnd_scale;
|
|
};
|
|
|
|
} // namespace cricket
|
|
|
|
#endif // WEBRTC_P2P_BASE_PSEUDOTCP_H_
|