tcp-full.h

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1997, 2001 The Regents of the University of California.
 * All rights reserved.
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 * modification, are permitted provided that the following conditions
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 *    must display the following acknowledgement:
 *  This product includes software developed by the Network Research
 *  Group at Lawrence Berkeley National Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
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 * @(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/tcp/tcp-full.h,v 1.53 2002/06/28 21:55:56 kclan Exp $ (LBL)
 */

#ifndef ns_tcp_full_h
#define ns_tcp_full_h

#include "tcp.h"
#include "rq.h"

/*
 * most of these defines are directly from
 * tcp_var.h or tcp_fsm.h in "real" TCP
 */


/*
 * these are used in 'tcp_flags_' member variable
 */

#define TF_ACKNOW       0x0001          /* ack peer immediately */
#define TF_DELACK       0x0002          /* ack, but try to delay it */
#define TF_NODELAY      0x0004          /* don't delay packets to coalesce */
#define TF_NOOPT        0x0008          /* don't use tcp options */
#define TF_SENTFIN      0x0010          /* have sent FIN */
#define TF_RCVD_TSTMP   0x0100          /* timestamp rcv'd in SYN */
#define TF_NEEDFIN      0x0800          /* send FIN (implicit state) */

/* these are simulator-specific */
#define TF_NEEDCLOSE    0x10000         /* perform close on empty */

/*
 * these are used in state_ member variable
 */

#define TCPS_CLOSED             0       /* closed */
#define TCPS_LISTEN             1       /* listening for connection */
#define TCPS_SYN_SENT           2       /* active, have sent syn */
#define TCPS_SYN_RECEIVED       3       /* have sent and received syn */
#define TCPS_ESTABLISHED        4       /* established */
#define TCPS_CLOSE_WAIT         5       /* rcvd fin, waiting for app close */
#define TCPS_FIN_WAIT_1         6       /* have closed, sent fin */
#define TCPS_CLOSING            7       /* closed xchd FIN; await FIN ACK */
#define TCPS_LAST_ACK           8       /* had fin and close; await FIN ACK */
#define TCPS_FIN_WAIT_2         9       /* have closed, fin is acked */

#define TCP_NSTATES             10      /* total number of states */

#define TCPS_HAVERCVDFIN(s) ((s) == TCPS_CLOSING || (s) == TCPS_CLOSED || (s) == TCPS_CLOSE_WAIT)
#define TCPS_HAVERCVDSYN(s) ((s) >= TCPS_SYN_RECEIVED)

#define TCPIP_BASE_PKTSIZE      40      /* base TCP/IP header in real life */
/* these are used to mark packets as to why we xmitted them */
#define REASON_NORMAL   0  
#define REASON_TIMEOUT  1
#define REASON_DUPACK   2
#define REASON_RBP      3       /* if ever implemented */
#define REASON_SACK     4       /* hole fills in SACK */

/* bits for the tcp_flags field below */
/* from tcp.h in the "real" implementation */
/* RST and URG are not used in the simulator */
 
#define TH_FIN  0x01        /* FIN: closing a connection */
#define TH_SYN  0x02        /* SYN: starting a connection */
#define TH_PUSH 0x08        /* PUSH: used here to "deliver" data */
#define TH_ACK  0x10        /* ACK: ack number is valid */
#define TH_ECE  0x40        /* ECE: CE echo flag */
#define TH_CWR  0x80        /* CWR: congestion window reduced */


#define PF_TIMEOUT 0x04     /* protocol defined */
#define TCP_PAWS_IDLE   (24 * 24 * 60 * 60)     /* 24 days in secs */

class FullTcpAgent;
class DelAckTimer : public TimerHandler {
public:
        DelAckTimer(FullTcpAgent *a) : TimerHandler(), a_(a) { }
protected:
        virtual void expire(Event *);
        FullTcpAgent *a_;
};

class FullTcpAgent : public TcpAgent {
public:
        FullTcpAgent() :
                closed_(0), pipe_(-1), rtxbytes_(0), fastrecov_(FALSE),
                last_send_time_(-1.0), infinite_send_(FALSE), irs_(-1),
                delack_timer_(this), flags_(0),
                state_(TCPS_CLOSED), ect_(FALSE), recent_ce_(FALSE),
                last_state_(TCPS_CLOSED), rq_(rcv_nxt_), last_ack_sent_(-1) { }

        ~FullTcpAgent() { cancel_timers(); rq_.clear(); }
        virtual void recv(Packet *pkt, Handler*);
        virtual void timeout(int tno);  // tcp_timers() in real code
        virtual void close() { usrclosed(); }
        void advanceby(int);    // over-rides tcp base version
        void advance_bytes(int);        // unique to full-tcp
        virtual void sendmsg(int nbytes, const char *flags = 0);
        virtual int& size() { return maxseg_; } //FullTcp uses maxseg_ for size_
        virtual int command(int argc, const char*const* argv);
protected:
        virtual void delay_bind_init_all();
        virtual int delay_bind_dispatch(const char *varName, const char *localName, TclObject *tracer);
        int closed_;
        int ts_option_size_;    // header bytes in a ts option
        int pipe_;              // estimate of pipe occupancy (for Sack)
        int pipectrl_;          // use pipe-style control
        int rtxbytes_;          // retransmitted bytes last recovery
        int open_cwnd_on_pack_; // open cwnd on a partial ack?
        int segs_per_ack_;  // for window updates
        int spa_thresh_;    // rcv_nxt < spa_thresh? -> 1 seg per ack
        int nodelay_;       // disable sender-side Nagle?
        int fastrecov_;     // are we in fast recovery?
        int deflate_on_pack_;   // deflate on partial acks (reno:yes)
        int data_on_syn_;   // send data on initial SYN?
        double last_send_time_; // time of last send
        int close_on_empty_;    // close conn when buffer empty
        int signal_on_empty_;   // signal when buffer is empty
        int reno_fastrecov_;    // do reno-style fast recovery?
        int infinite_send_;     // Always something to send
        int tcprexmtthresh_;    // fast retransmit threshold
        int iss_;       // initial send seq number
        int irs_;       // initial recv'd # (peer's iss)
        int dupseg_fix_;    // fix bug with dup segs and dup acks?
        int dupack_reset_;  // zero dupacks on dataful dup acks?
        int halfclose_;     // allow simplex closes?
        int nopredict_;     // disable header predication
        int dsack_;         // do DSACK as well as SACK?
        double delack_interval_;

        int headersize();   // a tcp header w/opts
        int outflags();     // state-specific tcp header flags
        int rcvseqinit(int, int); // how to set rcv_nxt_
        int predict_ok(Packet*); // predicate for recv-side header prediction
        int idle_restart();     // should I restart after idle?
        int fast_retransmit(int);  // do a fast-retransmit on specified seg
        inline double now() { return Scheduler::instance().clock(); }
        virtual void newstate(int ns);

        void bufferempty();             // called when sender buffer is empty

        void finish();
        void reset_rtx_timer(int);      // adjust the rtx timer

        virtual void timeout_action();  // what to do on rtx timeout
        virtual void dupack_action();   // what to do on dup acks
        virtual void pack_action(Packet*);      // action on partial acks
        virtual void ack_action(Packet*);       // action on acks
        virtual void reset();                   // reset to a known point
        virtual void send_much(int force, int reason, int maxburst = 0);
        virtual int build_options(hdr_tcp*);    // insert opts, return len
        virtual int reass(Packet*);             // reassemble: pass to ReassemblyQueue
        virtual void process_sack(hdr_tcp*);    // process a SACK
        virtual int send_allowed(int);          // ok to send this seq#?
        virtual int nxt_tseq() {
                return t_seqno_;                // next seq# to send
        }
        virtual void sent(int seq, int amt) {
                if (seq == t_seqno_)
                        t_seqno_ += amt;
                pipe_ += amt;
                if (seq < int(maxseq_))
                        rtxbytes_ += amt;
        }
        virtual void oldack() {                 // what to do on old ack
                dupacks_ = 0;
        }

        virtual void extra_ack() {              // dup ACKs after threshold
                if (reno_fastrecov_)
                        cwnd_++;
        }

        void sendpacket(int seq, int ack, int flags, int dlen, int why);
        void connect();                 // do active open
        void listen();                  // do passive open
        void usrclosed();               // user requested a close
        int need_send();                // send ACK/win-update now?
        int foutput(int seqno, int reason = 0); // output 1 packet
        void newack(Packet* pkt);       // process an ACK
        int pack(Packet* pkt);          // is this a partial ack?
        void dooptions(Packet*);        // process option(s)
        DelAckTimer delack_timer_;      // other timers in tcp.h
        void cancel_timers();           // cancel all timers
        void prpkt(Packet*);            // print packet (debugging helper)
        char *flagstr(int);             // print header flags as symbols
        char *statestr(int);            // print states as symbols

        /*
        * the following are part of a tcpcb in "real" RFC793 TCP
        */
        int maxseg_;        /* MSS */
        int flags_;     /* controls next output() call */
        int state_;     /* enumerated type: FSM state */
        int ect_;       /* turn on ect bit now? */
        int recent_ce_; /* last ce bit we saw */
        int last_state_; /* FSM state at last pkt recv */
        int rcv_nxt_;       /* next sequence number expected */
        ReassemblyQueue rq_;    /* TCP reassembly queue */
        /*
        * the following are part of a tcpcb in "real" RFC1323 TCP
        */
        int last_ack_sent_; /* ackno field from last segment we sent */
        double recent_;         // ts on SYN written by peer
        double recent_age_;     // my time when recent_ was set

        /*
         * setting iw, specific to tcp-full, called
         * by TcpAgent::reset()
         */
        void set_initial_window();
};

class NewRenoFullTcpAgent : public FullTcpAgent {

public:
        NewRenoFullTcpAgent();
protected:
        int     save_maxburst_;         // saved value of maxburst_
        int     recov_maxburst_;        // maxburst lim during recovery
        void pack_action(Packet*);
        void ack_action(Packet*);
};

class TahoeFullTcpAgent : public FullTcpAgent {
protected:
        void dupack_action();
};

class SackFullTcpAgent : public FullTcpAgent {
public:
        SackFullTcpAgent() :
                sq_(sack_min_), sack_min_(-1), h_seqno_(-1) { }
        ~SackFullTcpAgent() { rq_.clear(); }
protected:

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

        virtual void pack_action(Packet*);
        virtual void ack_action(Packet*);
        virtual void dupack_action();
        virtual void process_sack(hdr_tcp*);
        virtual void timeout_action();
        virtual int nxt_tseq();
        virtual int hdrsize(int nblks);
        virtual int send_allowed(int);
        virtual void sent(int seq, int amt) {
                if (seq == h_seqno_)
                        h_seqno_ += amt;
                FullTcpAgent::sent(seq, amt);
        }

        int build_options(hdr_tcp*);    // insert opts, return len
        int clear_on_timeout_;  // clear sender's SACK queue on RTX timeout?
        int sack_option_size_;  // base # bytes for sack opt (no blks)
        int sack_block_size_;   // # bytes in a sack block (def: 8)
        int max_sack_blocks_;   // max # sack blocks to send
        int sack_rtx_bthresh_;  // hole-fill byte threshold
        int sack_rtx_cthresh_;  // hole-fill counter threshold
        int sack_rtx_threshmode_;       // hole-fill mode setting


        void    reset();
        void    sendpacket(int seqno, int ackno, int pflags, int datalen, int reason);

        ReassemblyQueue sq_;    // SACK queue, used by sender
        int sack_min_;          // first seq# in sack queue, initializes sq_
        int h_seqno_;           // next seq# to hole-fill
};

#endif

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