tcp-sink.h

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#ifndef ns_tcpsink_h
#define ns_tcpsink_h

#include <math.h>
#include "agent.h"
#include "tcp.h"

/* max window size */
// #define MWS 1024  
#define MWS 64
#define MWM (MWS-1)
#define HS_MWS 65536
#define HS_MWM (MWS-1)
/* For Tahoe TCP, the "window" parameter, representing the receiver's
 * advertised window, should be less than MWM.  For Reno TCP, the
 * "window" parameter should be less than MWM/2.
 */

class TcpSink;
class Acker {
public:
    Acker();
    virtual ~Acker() { delete[] seen_; }
    void update_ts(int seqno, double ts, int rfc1323 = 0);
    int update(int seqno, int numBytes);
    void update_ecn_unacked(int value);
    inline int Seqno() const { return (next_ - 1); }
    virtual void append_ack(hdr_cmn*, hdr_tcp*, int oldSeqno) const;
    void reset();
    double ts_to_echo() { return ts_to_echo_;}
    int ecn_unacked() { return ecn_unacked_;}
    inline int Maxseen() const { return (maxseen_); }
    void resize_buffers(int sz);  // resize the seen_ buffer

protected:
    int next_;      /* next packet expected */
    int maxseen_;       /* max packet number seen */
    int wndmask_;       /* window mask - either MWM or HS_MWM - Sylvia */ 
    int ecn_unacked_;   /* ECN forwarded to sender, but not yet
                 * acknowledged. */
    int *seen_;     /* array of packets seen */
    double ts_to_echo_; /* timestamp to echo to peer */
    int is_dup_;        // A duplicate packet.
public:
        int last_ack_sent_;     // For updating timestamps, from Andrei Gurtov.
};

// derive Sacker from TclObject to allow for traced variable
class SackStack;
class Sacker : public Acker, public TclObject {
public: 
    Sacker() : base_nblocks_(-1), sf_(0) { };
    ~Sacker();
    void append_ack(hdr_cmn*, hdr_tcp*, int oldSeqno) const;
    void reset();
    void configure(TcpSink*);
protected:
    int base_nblocks_;
    int* dsacks_;       // Generate DSACK blocks.
    SackStack *sf_;
    void trace(TracedVar*);
};

class TcpSink : public Agent {
public:
    TcpSink(Acker*);
    void recv(Packet* pkt, Handler*);
    void reset();
    int command(int argc, const char*const* argv);
    TracedInt& maxsackblocks() { return max_sack_blocks_; }
protected:
    void ack(Packet*);
    virtual void add_to_ack(Packet* pkt);

        virtual void delay_bind_init_all();
        virtual int delay_bind_dispatch(const char *varName, const char *localName, TclObject *tracer);

    Acker* acker_;
    int ts_echo_bugfix_;
    int ts_echo_rfc1323_;   // conforms to rfc1323 for timestamps echo
                // Added by Andrei Gurtov

    friend void Sacker::configure(TcpSink*);
    TracedInt max_sack_blocks_; /* used only by sack sinks */
    Packet* save_;      /* place to stash saved packet while delaying */
                /* used by DelAckSink */
    int generate_dsacks_;   // used only by sack sinks
    int qs_enabled_; // to enable QuickStart 
    int RFC2581_immediate_ack_; // Used to generate ACKs immediately 
    int bytes_;     // for JOBS
                    // for RFC2581-compliant gap-filling.
    double lastreset_;  /* W.N. used for detecting packets  */
                /* from previous incarnations */
};

class DelAckSink;

class DelayTimer : public TimerHandler {
public:
    DelayTimer(DelAckSink *a) : TimerHandler() { a_ = a; }
protected:
    virtual void expire(Event *e);
    DelAckSink *a_;
};

class DelAckSink : public TcpSink {
public:
    DelAckSink(Acker* acker);
    void recv(Packet* pkt, Handler*);
    virtual void timeout(int tno);
    void reset();
protected:
    double interval_;
    DelayTimer delay_timer_;
};

#endif

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