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 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.
};

// 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_;

        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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