tcp-socket-base.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2007 Georgia Tech Research Corporation
 * Copyright (c) 2010 Adrian Sai-wah Tam
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Adrian Sai-wah Tam <adrian.sw.tam@gmail.com>
 */
#ifndef TCP_SOCKET_BASE_H
#define TCP_SOCKET_BASE_H

#include <stdint.h>
#include <queue>
#include "ns3/traced-value.h"
#include "ns3/tcp-socket.h"
#include "ns3/ipv4-header.h"
#include "ns3/ipv6-header.h"
#include "ns3/timer.h"
#include "ns3/sequence-number.h"
#include "ns3/data-rate.h"
#include "ns3/node.h"
#include "tcp-rx-buffer.h"
#include "tcp-tx-buffer.h"
#include "rtt-estimator.h"
#include "tcp-l4-protocol.h"

namespace ns3 {

class Ipv4EndPoint;
class Ipv6EndPoint;
class Node;
class Packet;
class TcpL4Protocol;
class TcpHeader;
class TcpCongestionOps;
class RttEstimator;
class TcpRxBuffer;
class TcpTxBuffer;
class TcpOption;
class Ipv4Interface;
class Ipv6Interface;

class RttHistory
{
public:
  RttHistory (SequenceNumber32 s, uint32_t c, Time t);
  RttHistory (const RttHistory& h); // Copy constructor
public:
  SequenceNumber32  seq;  
  uint32_t        count;  
  Time            time;   
  bool            retx;   
};

class TcpSocketState : public Object
{
public:
  static TypeId GetTypeId (void);

  TcpSocketState () : Object () { }

  TcpSocketState (const TcpSocketState &other);

  typedef enum
  {
    CA_OPEN,      
    CA_DISORDER,  
    CA_CWR,       
    CA_RECOVERY,  
    CA_LOSS,      
    CA_LAST_STATE 
  } TcpCongState_t;

  // Note: "not triggered" events are currently not triggered by the code.
  typedef enum
  {
    CA_EVENT_TX_START,     
    CA_EVENT_CWND_RESTART, 
    CA_EVENT_COMPLETE_CWR, 
    CA_EVENT_LOSS,         
    CA_EVENT_ECN_NO_CE,    
    CA_EVENT_ECN_IS_CE,    
    CA_EVENT_DELAYED_ACK,  
    CA_EVENT_NON_DELAYED_ACK, 
  } TcpCAEvent_t;

  typedef void (* TcpCongStatesTracedValueCallback)(const TcpCongState_t oldValue,
                                                    const TcpCongState_t newValue);

  static const char* const TcpCongStateName[TcpSocketState::CA_LAST_STATE];

  // Congestion control
  TracedValue<uint32_t>  m_cWnd             {0}; 
  TracedValue<uint32_t>  m_ssThresh         {0}; 
  uint32_t               m_initialCWnd      {0}; 
  uint32_t               m_initialSsThresh  {0}; 

  // Segment
  uint32_t               m_segmentSize   {0}; 
  SequenceNumber32       m_lastAckedSeq  {0}; 

  TracedValue<TcpCongState_t> m_congState {CA_OPEN}; 

  TracedValue<SequenceNumber32> m_highTxMark     {0}; 
  TracedValue<SequenceNumber32> m_nextTxSequence {0}; 

  uint32_t               m_rcvTimestampValue     {0}; 
  uint32_t               m_rcvTimestampEchoReply {0}; 

  // Pacing related variables
  bool                   m_pacing            {false}; 
  DataRate               m_maxPacingRate     {0};    
  DataRate               m_currentPacingRate {0};    

  Time                   m_minRtt  {Time::Max ()};   

  uint32_t GetCwndInSegments () const
  {
    return m_cWnd / m_segmentSize;
  }

  uint32_t GetSsThreshInSegments () const
  {
    return m_ssThresh / m_segmentSize;
  }
};

class TcpSocketBase : public TcpSocket
{
public:
  static TypeId GetTypeId (void);

  virtual TypeId GetInstanceTypeId () const;

  friend class TcpGeneralTest;

  TcpSocketBase (void);

  TcpSocketBase (const TcpSocketBase& sock);
  virtual ~TcpSocketBase (void);

  // Set associated Node, TcpL4Protocol, RttEstimator to this socket

  virtual void SetNode (Ptr<Node> node);

  virtual void SetTcp (Ptr<TcpL4Protocol> tcp);

  virtual void SetRtt (Ptr<RttEstimator> rtt);

  void SetMinRto (Time minRto);

  Time GetMinRto (void) const;

  void SetClockGranularity (Time clockGranularity);

  Time GetClockGranularity (void) const;

  Ptr<TcpTxBuffer> GetTxBuffer (void) const;

  Ptr<TcpRxBuffer> GetRxBuffer (void) const;

  void SetRetxThresh (uint32_t retxThresh);

  uint32_t GetRetxThresh (void) const { return m_retxThresh; }

  TracedCallback<uint32_t, uint32_t> m_cWndTrace;

  TracedCallback<uint32_t, uint32_t> m_ssThTrace;

  TracedCallback<TcpSocketState::TcpCongState_t, TcpSocketState::TcpCongState_t> m_congStateTrace;

  TracedCallback <SequenceNumber32, SequenceNumber32> m_highTxMarkTrace;

  TracedCallback<SequenceNumber32, SequenceNumber32> m_nextTxSequenceTrace;

  void UpdateCwnd (uint32_t oldValue, uint32_t newValue);

  void UpdateSsThresh (uint32_t oldValue, uint32_t newValue);

  void UpdateCongState (TcpSocketState::TcpCongState_t oldValue,
                        TcpSocketState::TcpCongState_t newValue);

  void UpdateHighTxMark (SequenceNumber32 oldValue, SequenceNumber32 newValue);

  void UpdateNextTxSequence (SequenceNumber32 oldValue, SequenceNumber32 newValue);

  void SetCongestionControlAlgorithm (Ptr<TcpCongestionOps> algo);

  // Necessary implementations of null functions from ns3::Socket
  virtual enum SocketErrno GetErrno (void) const;    // returns m_errno
  virtual enum SocketType GetSocketType (void) const; // returns socket type
  virtual Ptr<Node> GetNode (void) const;            // returns m_node
  virtual int Bind (void);    // Bind a socket by setting up endpoint in TcpL4Protocol
  virtual int Bind6 (void);    // Bind a socket by setting up endpoint in TcpL4Protocol
  virtual int Bind (const Address &address);         // ... endpoint of specific addr or port
  virtual int Connect (const Address &address);      // Setup endpoint and call ProcessAction() to connect
  virtual int Listen (void);  // Verify the socket is in a correct state and call ProcessAction() to listen
  virtual int Close (void);   // Close by app: Kill socket upon tx buffer emptied
  virtual int ShutdownSend (void);    // Assert the m_shutdownSend flag to prevent send to network
  virtual int ShutdownRecv (void);    // Assert the m_shutdownRecv flag to prevent forward to app
  virtual int Send (Ptr<Packet> p, uint32_t flags);  // Call by app to send data to network
  virtual int SendTo (Ptr<Packet> p, uint32_t flags, const Address &toAddress); // Same as Send(), toAddress is insignificant
  virtual Ptr<Packet> Recv (uint32_t maxSize, uint32_t flags); // Return a packet to be forwarded to app
  virtual Ptr<Packet> RecvFrom (uint32_t maxSize, uint32_t flags, Address &fromAddress); // ... and write the remote address at fromAddress
  virtual uint32_t GetTxAvailable (void) const; // Available Tx buffer size
  virtual uint32_t GetRxAvailable (void) const; // Available-to-read data size, i.e. value of m_rxAvailable
  virtual int GetSockName (Address &address) const; // Return local addr:port in address
  virtual int GetPeerName (Address &address) const;
  virtual void BindToNetDevice (Ptr<NetDevice> netdevice); // NetDevice with my m_endPoint

  typedef void (* TcpTxRxTracedCallback)(const Ptr<const Packet> packet, const TcpHeader& header,
                                         const Ptr<const TcpSocketBase> socket);

protected:
  // Implementing ns3::TcpSocket -- Attribute get/set
  // inherited, no need to doc

  virtual void     SetSndBufSize (uint32_t size);
  virtual uint32_t GetSndBufSize (void) const;
  virtual void     SetRcvBufSize (uint32_t size);
  virtual uint32_t GetRcvBufSize (void) const;
  virtual void     SetSegSize (uint32_t size);
  virtual uint32_t GetSegSize (void) const;
  virtual void     SetInitialSSThresh (uint32_t threshold);
  virtual uint32_t GetInitialSSThresh (void) const;
  virtual void     SetInitialCwnd (uint32_t cwnd);
  virtual uint32_t GetInitialCwnd (void) const;
  virtual void     SetConnTimeout (Time timeout);
  virtual Time     GetConnTimeout (void) const;
  virtual void     SetSynRetries (uint32_t count);
  virtual uint32_t GetSynRetries (void) const;
  virtual void     SetDataRetries (uint32_t retries);
  virtual uint32_t GetDataRetries (void) const;
  virtual void     SetDelAckTimeout (Time timeout);
  virtual Time     GetDelAckTimeout (void) const;
  virtual void     SetDelAckMaxCount (uint32_t count);
  virtual uint32_t GetDelAckMaxCount (void) const;
  virtual void     SetTcpNoDelay (bool noDelay);
  virtual bool     GetTcpNoDelay (void) const;
  virtual void     SetPersistTimeout (Time timeout);
  virtual Time     GetPersistTimeout (void) const;
  virtual bool     SetAllowBroadcast (bool allowBroadcast);
  virtual bool     GetAllowBroadcast (void) const;



  // Helper functions: Connection set up

  int SetupCallback (void);

  int DoConnect (void);

  void ConnectionSucceeded (void);

  int SetupEndpoint (void);

  int SetupEndpoint6 (void);

  virtual void CompleteFork (Ptr<Packet> p, const TcpHeader& tcpHeader,
                             const Address& fromAddress, const Address& toAddress);



  // Helper functions: Transfer operation

  void ForwardUp (Ptr<Packet> packet, Ipv4Header header, uint16_t port, Ptr<Ipv4Interface> incomingInterface);

  void ForwardUp6 (Ptr<Packet> packet, Ipv6Header header, uint16_t port, Ptr<Ipv6Interface> incomingInterface);

  virtual void DoForwardUp (Ptr<Packet> packet, const Address &fromAddress,
                            const Address &toAddress);

  void ForwardIcmp (Ipv4Address icmpSource, uint8_t icmpTtl, uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo);

  void ForwardIcmp6 (Ipv6Address icmpSource, uint8_t icmpTtl, uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo);

  uint32_t SendPendingData (bool withAck = false);

  uint32_t SendDataPacket (SequenceNumber32 seq, uint32_t maxSize, bool withAck);

  virtual void SendEmptyPacket (uint8_t flags);

  void SendRST (void);

  bool OutOfRange (SequenceNumber32 head, SequenceNumber32 tail) const;


  // Helper functions: Connection close

  int DoClose (void);

  void CloseAndNotify (void);

  void Destroy (void);

  void Destroy6 (void);

  void DeallocateEndPoint (void);

  void PeerClose (Ptr<Packet> p, const TcpHeader& tcpHeader);

  void DoPeerClose (void);

  void CancelAllTimers (void);

  void TimeWait (void);

  // State transition functions

  void ProcessEstablished (Ptr<Packet> packet, const TcpHeader& tcpHeader); // Received a packet upon ESTABLISHED state

  void ProcessListen (Ptr<Packet> packet, const TcpHeader& tcpHeader,
                      const Address& fromAddress, const Address& toAddress);

  void ProcessSynSent (Ptr<Packet> packet, const TcpHeader& tcpHeader);

  void ProcessSynRcvd (Ptr<Packet> packet, const TcpHeader& tcpHeader,
                       const Address& fromAddress, const Address& toAddress);

  void ProcessWait (Ptr<Packet> packet, const TcpHeader& tcpHeader);

  void ProcessClosing (Ptr<Packet> packet, const TcpHeader& tcpHeader);

  void ProcessLastAck (Ptr<Packet> packet, const TcpHeader& tcpHeader);

  // Window management

  virtual uint32_t UnAckDataCount (void) const;

  virtual uint32_t BytesInFlight (void) const;

  virtual uint32_t Window (void) const;

  virtual uint32_t AvailableWindow (void) const;

  virtual uint16_t AdvertisedWindowSize (bool scale = true) const;

  void UpdateWindowSize (const TcpHeader& header);


  // Manage data tx/rx

  virtual Ptr<TcpSocketBase> Fork (void);

  virtual void ReceivedAck (Ptr<Packet> packet, const TcpHeader& tcpHeader);

  virtual void ProcessAck (const SequenceNumber32 &ackNumber, bool scoreboardUpdated,
                           const SequenceNumber32 &oldHeadSequence);

  virtual void ReceivedData (Ptr<Packet> packet, const TcpHeader& tcpHeader);

  virtual void EstimateRtt (const TcpHeader& tcpHeader);

  virtual void UpdateRttHistory (const SequenceNumber32 &seq, uint32_t sz,
                                 bool isRetransmission);

  virtual void NewAck (SequenceNumber32 const& seq, bool resetRTO);

  void DupAck ();

  void EnterRecovery ();

  virtual void ReTxTimeout (void);

  virtual void DelAckTimeout (void);

  virtual void LastAckTimeout (void);

  virtual void PersistTimeout (void);

  void DoRetransmit (void);

  void AddOptions (TcpHeader& tcpHeader);

  void ReadOptions (const TcpHeader &tcpHeader, bool &scoreboardUpdated);

  bool IsTcpOptionEnabled (uint8_t kind) const;

  void ProcessOptionWScale (const Ptr<const TcpOption> option);
  void AddOptionWScale (TcpHeader& header);

  uint8_t CalculateWScale () const;

  void ProcessOptionSackPermitted (const Ptr<const TcpOption> option);

  bool ProcessOptionSack (const Ptr<const TcpOption> option);

  void AddOptionSackPermitted (TcpHeader &header);

  void AddOptionSack (TcpHeader& header);

  void ProcessOptionTimestamp (const Ptr<const TcpOption> option,
                               const SequenceNumber32 &seq);
  void AddOptionTimestamp (TcpHeader& header);

  static uint32_t SafeSubtraction (uint32_t a, uint32_t b);

  void NotifyPacingPerformed (void);

  void AddSocketTags (const Ptr<Packet> &p) const;

protected:
  // Counters and events
  EventId           m_retxEvent     {}; 
  EventId           m_lastAckEvent  {}; 
  EventId           m_delAckEvent   {}; 
  EventId           m_persistEvent  {}; 
  EventId           m_timewaitEvent {}; 

  // ACK management
  uint32_t          m_dupAckCount {0};     
  uint32_t          m_delAckCount {0};     
  uint32_t          m_delAckMaxCount {0};  

  // Nagle algorithm
  bool              m_noDelay {false};     

  // Retries
  uint32_t          m_synCount     {0}; 
  uint32_t          m_synRetries   {0}; 
  uint32_t          m_dataRetrCount {0}; 
  uint32_t          m_dataRetries  {0}; 

  // Timeouts
  TracedValue<Time> m_rto     {Seconds (0.0)}; 
  Time              m_minRto  {Time::Max ()};   
  TracedValue<Time> m_lastRtt {Seconds (0.0)}; 
  Time              m_clockGranularity {Seconds (0.001)}; 
  Time              m_delAckTimeout    {Seconds (0.0)};   
  Time              m_persistTimeout   {Seconds (0.0)};   
  Time              m_cnTimeout        {Seconds (0.0)};   

  // History of RTT
  std::deque<RttHistory>      m_history;         

  // Connections to other layers of TCP/IP
  Ipv4EndPoint*       m_endPoint  {nullptr}; 
  Ipv6EndPoint*       m_endPoint6 {nullptr}; 
  Ptr<Node>           m_node      {nullptr}; 
  Ptr<TcpL4Protocol>  m_tcp       {nullptr}; 
  Callback<void, Ipv4Address,uint8_t,uint8_t,uint8_t,uint32_t> m_icmpCallback;  
  Callback<void, Ipv6Address,uint8_t,uint8_t,uint8_t,uint32_t> m_icmpCallback6; 

  Ptr<RttEstimator> m_rtt {nullptr}; 

  // Rx and Tx buffer management
  Ptr<TcpRxBuffer> m_rxBuffer {nullptr}; 
  Ptr<TcpTxBuffer> m_txBuffer {nullptr}; 

  // State-related attributes
  TracedValue<TcpStates_t> m_state {CLOSED};         
  mutable enum SocketErrno m_errno {ERROR_NOTERROR}; 
  bool                     m_closeNotified {false};  
  bool                     m_closeOnEmpty  {false};  
  bool                     m_shutdownSend  {false};  
  bool                     m_shutdownRecv  {false};  
  bool                     m_connected     {false};  
  double                   m_msl           {0.0};    

  // Window management
  uint16_t         m_maxWinSize              {0};  
  uint32_t         m_bytesAckedNotProcessed  {0};  
  SequenceNumber32 m_highTxAck               {0};  
  TracedValue<uint32_t> m_rWnd               {0};  
  TracedValue<uint32_t> m_advWnd             {0};  
  TracedValue<SequenceNumber32> m_highRxMark {0};  
  TracedValue<SequenceNumber32> m_highRxAckMark {0}; 
  TracedValue<uint32_t>         m_bytesInFlight {0}; 

  // Options
  bool    m_sackEnabled       {true}; 
  bool    m_winScalingEnabled {true}; 
  uint8_t m_rcvWindShift      {0};    
  uint8_t m_sndWindShift      {0};    
  bool     m_timestampEnabled {true}; 
  uint32_t m_timestampToEcho  {0};    

  EventId m_sendPendingDataEvent {}; 

  // Fast Retransmit and Recovery
  SequenceNumber32       m_recover    {0};   
  uint32_t               m_retxThresh {3};   
  bool                   m_limitedTx  {true}; 

  // Transmission Control Block
  Ptr<TcpSocketState>    m_tcb {nullptr};               
  Ptr<TcpCongestionOps>  m_congestionControl {nullptr}; 

  // Guesses over the other connection end
  bool m_isFirstPartialAck {true}; 

  // The following two traces pass a packet with a TCP header
  TracedCallback<Ptr<const Packet>, const TcpHeader&,
                 Ptr<const TcpSocketBase> > m_txTrace; 

  TracedCallback<Ptr<const Packet>, const TcpHeader&,
                 Ptr<const TcpSocketBase> > m_rxTrace; 

  // Pacing related variable
  Timer m_pacingTimer {Timer::REMOVE_ON_DESTROY}; 

  TracedValue<uint32_t> m_cWndInfl {0};
};

typedef void (* TcpCongStatesTracedValueCallback)(const TcpSocketState::TcpCongState_t oldValue,
                                                  const TcpSocketState::TcpCongState_t newValue);

} // namespace ns3

#endif /* TCP_SOCKET_BASE_H */