| /* |
| * 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_ |