ckcfn2.c

C-Kermit源码。是使用串口/Modem和网络通讯的程序

/*  C K C F N 2  --  System-independent Kermit protocol support functions... */

/*  ...Part 2 (continued from ckcfns.c)  */

/*
  Author: Frank da Cruz <[e-mail]>,
  Columbia University Academic Information Systems, New York City.

  Copyright (C) 1985, 2000,
    Trustees of Columbia University in the City of New York.
    All rights reserved.  See the C-Kermit COPYING.TXT file or the
    copyright text in the ckcmai.c module for disclaimer and permissions.
*/
/*
 Note -- if you change this file, please amend the version number and date at
 the top of ckcfns.c accordingly.
*/

#include "ckcsym.h"			/* Compilation options */
#include "ckcdeb.h"			/* Debugging and other symbols */
#include "ckcasc.h"			/* ASCII symbols */
#include "ckcker.h"			/* Kermit symbols */
#include "ckcxla.h"			/* Translation */
#include "ckcnet.h"			/* IKS and VMS #define TCPSOCKET */

#ifdef TCPSOCKET			/* For TELNET business in spack() */
extern int tn_nlm, ttnproto, tn_b_nlm;
#endif /* TCPSOCKET */

extern int parity, network, local, interrupted, fatalio, wasclosed;

int kstartactive = 0;			/* Flag for kstart() in a packet */

static CHAR p_tbl[] = {			/* Even parity table for dopar(). */
    (CHAR) '\000',			/* ANSI C casts '\ooo' constants  */
    (CHAR) '\201',			/* to signed char, so we have to  */
    (CHAR) '\202',			/* cast back to unsigned char...  */
    (CHAR) '\003',
    (CHAR) '\204',
    (CHAR) '\005',
    (CHAR) '\006',
    (CHAR) '\207',
    (CHAR) '\210',
    (CHAR) '\011',
    (CHAR) '\012',
    (CHAR) '\213',
    (CHAR) '\014',
    (CHAR) '\215',
    (CHAR) '\216',
    (CHAR) '\017',
    (CHAR) '\220',
    (CHAR) '\021',
    (CHAR) '\022',
    (CHAR) '\223',
    (CHAR) '\024',
    (CHAR) '\225',
    (CHAR) '\226',
    (CHAR) '\027',
    (CHAR) '\030',
    (CHAR) '\231',
    (CHAR) '\232',
    (CHAR) '\033',
    (CHAR) '\234',
    (CHAR) '\035',
    (CHAR) '\036',
    (CHAR) '\237',
    (CHAR) '\240',
    (CHAR) '\041',
    (CHAR) '\042',
    (CHAR) '\243',
    (CHAR) '\044',
    (CHAR) '\245',
    (CHAR) '\246',
    (CHAR) '\047',
    (CHAR) '\050',
    (CHAR) '\251',
    (CHAR) '\252',
    (CHAR) '\053',
    (CHAR) '\254',
    (CHAR) '\055',
    (CHAR) '\056',
    (CHAR) '\257',
    (CHAR) '\060',
    (CHAR) '\261',
    (CHAR) '\262',
    (CHAR) '\063',
    (CHAR) '\264',
    (CHAR) '\065',
    (CHAR) '\066',
    (CHAR) '\267',
    (CHAR) '\270',
    (CHAR) '\071',
    (CHAR) '\072',
    (CHAR) '\273',
    (CHAR) '\074',
    (CHAR) '\275',
    (CHAR) '\276',
    (CHAR) '\077',
    (CHAR) '\300',
    (CHAR) '\101',
    (CHAR) '\102',
    (CHAR) '\303',
    (CHAR) '\104',
    (CHAR) '\305',
    (CHAR) '\306',
    (CHAR) '\107',
    (CHAR) '\110',
    (CHAR) '\311',
    (CHAR) '\312',
    (CHAR) '\113',
    (CHAR) '\314',
    (CHAR) '\115',
    (CHAR) '\116',
    (CHAR) '\317',
    (CHAR) '\120',
    (CHAR) '\321',
    (CHAR) '\322',
    (CHAR) '\123',
    (CHAR) '\324',
    (CHAR) '\125',
    (CHAR) '\126',
    (CHAR) '\327',
    (CHAR) '\330',
    (CHAR) '\131',
    (CHAR) '\132',
    (CHAR) '\333',
    (CHAR) '\134',
    (CHAR) '\335',
    (CHAR) '\336',
    (CHAR) '\137',
    (CHAR) '\140',
    (CHAR) '\341',
    (CHAR) '\342',
    (CHAR) '\143',
    (CHAR) '\344',
    (CHAR) '\145',
    (CHAR) '\146',
    (CHAR) '\347',
    (CHAR) '\350',
    (CHAR) '\151',
    (CHAR) '\152',
    (CHAR) '\353',
    (CHAR) '\154',
    (CHAR) '\355',
    (CHAR) '\356',
    (CHAR) '\157',
    (CHAR) '\360',
    (CHAR) '\161',
    (CHAR) '\162',
    (CHAR) '\363',
    (CHAR) '\164',
    (CHAR) '\365',
    (CHAR) '\366',
    (CHAR) '\167',
    (CHAR) '\170',
    (CHAR) '\371',
    (CHAR) '\372',
    (CHAR) '\173',
    (CHAR) '\374',
    (CHAR) '\175',
    (CHAR) '\176',
    (CHAR) '\377'
};

/*  D O P A R  --  Add an appropriate parity bit to a character  */

CHAR
#ifdef CK_ANSIC
dopar(register CHAR ch)
#else
dopar(ch) register CHAR ch;
#endif /* CK_ANSIC */
    {
    register unsigned int a;
    if (!parity
#ifdef TCPSOCKET
        || (network && (ttnproto == NP_TELNET) && (TELOPT_ME(TELOPT_BINARY)))
#ifndef NOXFER
	|| (!local && sstelnet)		/* TELNET BINARY MODE */
#endif /* NOXFER */
#endif /* TCPSOCKET */
        ) return((CHAR) (ch & 255)); else a = ch & 127;
    switch (parity) {
	case 'e':  return(p_tbl[a]);	             /* Even */
	case 'm':  return((CHAR) (a | 128));         /* Mark */
	case 'o':  return((CHAR) (p_tbl[a] ^ 128));  /* Odd */
	case 's':  return((CHAR) a);	             /* Space */
	default:   return((CHAR) a);                 /* Something illegal */
    }
}

#ifndef NOXFER				/* Rest of this file... */

#define NEWDPL				/* New dynamic packet length method */

#ifdef VMS
extern int batch;
#else
extern int backgrd;
#endif /* VMS */

#ifdef DYNAMIC
extern struct pktinfo *s_pkt;		/* array of pktinfo structures */
extern struct pktinfo *r_pkt;		/* array of pktinfo structures */
#else
extern struct pktinfo s_pkt[];		/* array of pktinfo structures */
extern struct pktinfo r_pkt[];		/* array of pktinfo structures */
#endif /* DYNAMIC */

extern int sseqtbl[], rseqtbl[], sbufuse[], sacktbl[], wslots, winlo,
  sbufnum, rbufnum, pktpaus, reliable;

#ifdef STREAMING
static int dontsend = 0;
extern int streaming;
#endif /* STREAMING */

extern int ttprty;			/* from ck*tio.c */
extern int autopar;

extern int spsiz, spmax, rpsiz, timint, timef, npad, bestlen, maxsend;
extern int rpt, rptq, rptflg, capas, spsizf, en_fin, tsecs, flow;
extern int pktnum, sndtyp, rcvtyp, bctr, bctu, bctl, rsn, rln, maxtry, size;
extern int osize, maxsize, spktl, rpktl, nfils, stdouf, fsecs;
extern int turn, turnch, displa, pktlog, seslog, xflg, mypadn;
extern int hcflg, server, cxseen, czseen, discard, slostart;
extern int nakstate, quiet, success, xitsta, what, filestatus;
extern int spackets, rpackets, timeouts, retrans, crunched, urpsiz;
extern int carrier, fdispla, srvidl;

#ifdef GFTIMER
extern CKFLOAT fptsecs, fpfsecs, fpxfsecs;
#endif /* GFTIMER */

extern long filcnt, filrej, ffc, flci, flco, tlci, tlco, tfc, speed;
extern long filcps, tfcps;

extern char *cmarg, filnam[];

extern CHAR padch, mypadc, eol, seol, ctlq, sstate;
extern CHAR *recpkt, *data, myinit[];
extern CHAR *srvptr, stchr, mystch, *rdatap;
extern CHAR padbuf[];
extern CHAR * epktmsg;
extern int epktrcvd, epktsent;

#ifdef OS2				/* AUTODOWNLOAD parameters */
extern int adl_kmode, adl_zmode;	/* Match Packet to signal download */
extern char * adl_kstr;			/* KERMIT Download String */
extern char * adl_zstr;			/* ZMODEM Download String */
#endif /* OS2 */

#ifdef CK_AUTODL
CHAR ksbuf[96] = { NUL, NUL };		/* Autodownload "Kermit Start" buf */
#endif /* CK_AUTODL */

int numerrs = 0;			/* Number of packet errors so far */
int rcvtimo = 0;			/* Timeout for receiving a packet */
int idletmo = 0;			/* Flag for idle timeout */

long filcps = 0L;			/* CPS most recent file transferred */
long tfcps  = 0L;			/* CPS most recent transaction */
long xfsecs = 0L;			/* Elapsed time for most recent file */
#ifdef GFTIMER
CKFLOAT fpxfsecs = 0.0;			/* Ditto, but floating point */
#endif /* GFTIMER */

#ifdef CK_TIMERS
int rrttbl[64], srttbl[64];		/* Packet timestamp tables */
extern int rttflg;
#define RTT_SCALE 1000
long
  rttsamples,				/* Round trip time samples */
  rttdelay,				/* RTT delay */
  pktintvl,				/* Interpacket arrival time */
  rttvariance,				/* RTT variance */
  rttstddev;				/* RTT standard deviation */
#endif /* CK_TIMERS */

/* CRC generation tables */

long crcta[16] = { 0L, 010201L, 020402L, 030603L, 041004L,
  051205L, 061406L, 071607L, 0102010L, 0112211L, 0122412L, 0132613L, 0143014L,
  0153215L, 0163416L, 0173617L
};

long crctb[16] = { 0L, 010611L, 021422L, 031233L, 043044L,
  053655L, 062466L, 072277L, 0106110L, 0116701L, 0127532L, 0137323L, 0145154L,
  0155745L, 0164576L, 0174367L
};

#ifdef CK_TIMERS
/*
  Round-trip timer calculations adapted from Tim Kientzle's article,
  "Improving Kermit Performance", Dr Dobb's Journal, February 1996.
*/


/*  R T T I N I T  --  Initialize timers at start of transaction  */

VOID
rttinit() {				/* Initialize round-trip timing */
    int i;

    if (timint == 0)
      return;

    rttsamples  = 0L;			/* Samples (packets) */
    rttvariance = 0L;			/* Variance in delay */
    rttdelay    = (long) timint * RTT_SCALE; /* Delay */
    pktintvl    = (long) timint * RTT_SCALE; /* Delay */
    rttstddev   = (long) timint * RTT_SCALE; /* Standard deviation of delay */

    /* Tables of timestamps indexed by packet sequence number */

    for (i = 0; i < 64; i++) {
	rrttbl[i] = -1;			/* Time each packet was received */
	srttbl[i] = -1;			/* Time each packet was sent */
    }
    rcvtimo = timint;			/* Initial timeout is what user said */
}

/*  G E T R T T  --  Get packet round trip time  */
/*
  Call with nakstate == 0 if file sender, nonzero if receiver,
  and n == packet sequence number of the packet we just received.

  Returns:
  -1 on failure with rcvtimo set to timint (what the user said), or:
   0 on success with rcvtimo set to dynamically calculated value:
     1 <= rcvtimo <= timint * 3.
*/
int
getrtt(nakstate, n) int nakstate, n; {
    long rttdiff;
    extern int mintime, maxtime;

    int x, y, yy, z = 0, zz = 0;	/* How long did it take to get here? */

    rcvtimo = timint;			/* Default timeout is what user said */

    if (timint == 0)			/* We're not timing out. */
      return(0);

    if (!rttflg)			/* Not supposed to be doing this? */
      return(-1);			/*  So don't */

    if (!RTT_SCALE)			/* Paranoia... */
      return(-1);

    /* rtimer() (reset timer) is not called until 1st data packet */
#ifdef GFTIMER
    /* rftimer(); */
#endif /* GFTIMER */
    /* S (F [ A ] D* Z)* B */

    /* NOTE: we calculate both the round-trip time AND the packet */
    /* arrival rate.  We don't use the RTT for anything, we just display it. */
    /* Timeouts are based on the packet arrival rate. */

    if (spackets > 3) {			/* Don't start till 4th packet */
	if (nakstate) {			/* File receiver */
	    x = rrttbl[n];		     /* Time when I got packet n */
	    y = rrttbl[n > 0 ? n - 1 : 63];  /* Time when I got packet n-1 */
	    yy = srttbl[n > 0 ? n - 1 : 63]; /* Time when I sent ACK(n-1) */
	    if (x > -1 && y > -1) {	/* Be careful */
		z = x - y;		/* Packet rate */
		zz = x - yy;		/* Round trip time */
		debug(F101,"RTT RECV","",z);
	    } else {			/* This shouldn't happen */
		debug(F101,"RTT RECV ERROR spackets","",spackets);
		debug(F101,"RTT RECV ERROR sequence","",n);
		return(-1);
	    }
	} else {			/* File sender */
	    x = rrttbl[n];		/* Time when I got ACK(n) */
	    y = rrttbl[n > 0 ? n - 1 : 63]; /* Time when I got packet n-1 */
	    yy = srttbl[n];		/* Time when I sent n */
	    if (x > -1 && y > -1) {
		z = x - y;		/* Packet rate */
		zz = x - yy;		/* Round trip time */
		debug(F101,"RTT SEND","",z);
	    } else {
		debug(F100,"RTT SEND ERROR","",0);
		return(-1);
	    }
	}
	if (z < 1)			/* For fast connections */
	  z = RTT_SCALE / 2;		/* Convert to scale... */
	else
	  z *= RTT_SCALE;

	if (zz < 1)			/* For fast connections */
	  zz = RTT_SCALE / 2;		/* Convert to scale... */
	else
	  zz *= RTT_SCALE;

	rttdelay = zz;			/* Round trip time of this packet */
	if (rttsamples++ == 0L) {	/* First sample */
	    pktintvl = z;
	    rttdiff = 0;
	} else {			/* Subsequent samples */
	    long oldavg = pktintvl;
	    long rttdiffsq;

	    if (rttsamples > 30)	/* Use real average for first 30 */
	      rttsamples = 30;		/*  then decaying average. */

	    /* Average delay, difference squared, variance, std deviation */

	    pktintvl += (z - pktintvl) / rttsamples;
	    rttdiffsq = (z - oldavg) * (z - oldavg);
	    rttvariance += (rttdiffsq - rttvariance) / rttsamples;
	    debug(F101,"RTT stddev1","",rttstddev);
	    if (rttstddev < 1L)		/* It can be zero, in which case */
	      rttstddev = RTT_SCALE / 3; /* set it to something small... */
	    rttstddev = (rttstddev + rttvariance / rttstddev) / 2;
	}
	debug(F101,"RTT stddev2","",rttstddev);
	debug(F101,"RTT delay  ","",pktintvl);