ckcfns.c

C 语言核心协议的 C 语言源代码

char *fnsv = "C-Kermit functions, 4C(048) 19 Mar 86";

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

/*  ...Part 1 (others moved to ckcfn2 to make this module small enough) */
/*
 Author: Frank da Cruz (SY.FDC@CU20B),
 Columbia University Center for Computing Activities, January 1985.
 Copyright (C) 1985, Trustees of Columbia University in the City of New York.
 Permission is granted to any individual or institution to use, copy, or
 redistribute this software so long as it is not sold for profit, provided this
 copyright notice is retained. 
*/
/*
 System-dependent primitives defined in:

   ck?tio.c -- terminal i/o
   cx?fio.c -- file i/o, directory structure
*/
#include "ckcker.h"			/* Symbol definitions for Kermit */
#include "ckcdeb.h"			/* Debug formats, typedefs, etc. */

#ifndef NULL
#define NULL 0
#endif

/* Externals from ckcmai.c */
extern int spsiz, rpsiz, timint, rtimo, npad, chklen, ebq, ebqflg, rpt, rptq,
 rptflg, capas, keep;
extern int pktnum, prvpkt, sndtyp, bctr, bctu,
 size, osize, maxsize, spktl, nfils, stdouf, warn, timef, spsizf;
extern int parity, speed, turn, turnch, 
 delay, displa, pktlog, tralog, seslog, xflg, mypadn;
extern long filcnt, ffc, flci, flco, tlci, tlco, tfc, tsecs, fsize;
extern int deblog, hcflg, binary, savmod, fncnv, local, server, cxseen, czseen;
extern CHAR padch, mypadc, eol, seol, ctlq, myctlq, sstate;
extern CHAR filnam[], sndpkt[], recpkt[], data[], srvcmd[], stchr, mystch;
extern char *cmarg, *cmarg2, *hlptxt, **cmlist;
extern CHAR *srvptr;
long zchki();
char *strcpy();

/* Variables local to this module */

static char *memptr;			/* Pointer for memory strings */

static char cmdstr[100];		/* Unix system command string */

static int  sndsrc;			/* Flag for where to send from: */
					/* -1: name in cmdata */
					/*  0: stdin          */
					/* >0: list in cmlist */

static int  memstr,			/* Flag for input from memory string */
    first;				/* Flag for first char from input */
static CHAR t,				/* Current character */
    next;				/* Next character */

/*  E N C S T R  --  Encode a string from memory. */

/*  Call this instead of getpkt() if source is a string, rather than a file. */

encstr(s) char* s; {
    int m; char *p;

    m = memstr; p = memptr;		/* Save these. */

    memptr = s;				/* Point to the string. */
    memstr = 1;				/* Flag memory string as source. */
    first = 1;				/* Initialize character lookahead. */
    getpkt(spsiz);			/* Fill a packet from the string. */
    memstr = m;				/* Restore memory string flag */
    memptr = p;				/* and pointer */
    first = 1;				/* Put this back as we found it. */
}

/* E N C O D E - Kermit packet encoding procedure */

encode(a) CHAR a; {			/* The current character */
    int a7;				/* Low order 7 bits of character */
    int b8;				/* 8th bit of character */

    if (rptflg)	{   	    		/* Repeat processing? */
        if (a == next && (first == 0)) { /* Got a run... */
	    if (++rpt < 94)		/* Below max, just count */
                return;
	    else if (rpt == 94) {	/* Reached max, must dump */
                data[size++] = rptq;
                data[size++] = tochar(rpt);
                rpt = 0;
	    }
        } else if (rpt == 1) {		/* Run broken, only 2? */
            rpt = 0;			/* Yes, reset repeat flag & count. */
	    encode(a);			/* Do the character twice. */
	    if (size <= maxsize) osize = size;
	    rpt = 0;
	    encode(a);
	    return;
	} else if (rpt > 1) {		/* More than two */
            data[size++] = rptq;	/* Insert the repeat prefix */
            data[size++] = tochar(++rpt); /* and count. */
            rpt = 0;			/* Reset repeat counter. */
        }
    }
    a7 = a & 0177;			/* Isolate ASCII part */
    b8 = a & 0200;			/* and 8th (parity) bit. */

    if (ebqflg && b8) {			/* Do 8th bit prefix if necessary. */
        data[size++] = ebq;
        a = a7;
    }
    if ((a7 < SP) || (a7==DEL))	{	/* Do control prefix if necessary */
        data[size++] = myctlq;
	a = ctl(a);
    }
    if (a7 == myctlq)			/* Prefix the control prefix */
        data[size++] = myctlq;

    if ((rptflg) && (a7 == rptq))	/* If it's the repeat prefix, */
        data[size++] = myctlq;		/* quote it if doing repeat counts. */

    if ((ebqflg) && (a7 == ebq))	/* Prefix the 8th bit prefix */
        data[size++] = myctlq;		/* if doing 8th-bit prefixes */

    data[size++] = a;			/* Finally, insert the character */
    data[size] = '\0';			/* itself, and mark the end. */
}

/* D E C O D E  --  Kermit packet decoding procedure */

/* Call with string to be decoded and an output function. */
/* Returns 0 on success, -1 on failure (e.g. disk full).  */

decode(buf,fn) char *buf; int (*fn)(); {
    unsigned int a, a7, b8;		/* Low order 7 bits, and the 8th bit */

    rpt = 0;				/* Initialize repeat count. */

    while ((a = *buf++) != '\0') {
	if (rptflg) {			/* Repeat processing? */
	    if (a == rptq) {		/* Yes, got a repeat prefix? */
		rpt = unchar(*buf++);	/* Yes, get the repeat count, */
		a = *buf++;		/* and get the prefixed character. */
	    }
	}
	b8 = 0;				/* Check high order "8th" bit */
	if (ebqflg) {			/* 8th-bit prefixing? */
	    if (a == ebq) {		/* Yes, got an 8th-bit prefix? */
		b8 = 0200;		/* Yes, remember this, */
		a = *buf++;		/* and get the prefixed character. */
	    }
	}
	if (a == ctlq) {		/* If control prefix, */
	    a  = *buf++;		/* get its operand. */
	    a7 = a & 0177;		/* Only look at low 7 bits. */
	    if ((a7 >= 0100 && a7 <= 0137) || a7 == '?') /* Uncontrollify */
	    a = ctl(a);			/* if in control range. */
	}
	a |= b8;			/* OR in the 8th bit */
	if (rpt == 0) rpt = 1;		/* If no repeats, then one */
#ifdef NLCHAR
	if (!binary) {			/* If in text mode, */
	    if (a == CR) continue;	/* discard carriage returns, */
    	    if (a == LF) a = NLCHAR; 	/* convert LF to system's newline. */
    	}
#endif
	for (; rpt > 0; rpt--) {	/* Output the char RPT times */
	    ffc++, tfc++;		/* Count the character */
	    if ((*fn)(a) < 0) return(-1); /* Send it to the output function. */
	}
    }
    return(0);
}


/*  Output functions passed to 'decode':  */

putsrv(c) char c; { 	/*  Put character in server command buffer  */
    *srvptr++ = c;
    *srvptr = '\0';	/* Make sure buffer is null-terminated */
    return(0);
}

puttrm(c) char c; {     /*  Output character to console.  */
    conoc(c);
    return(0);
}

putfil(c) char c; {			/*  Output char to file. */
    if (zchout(ZOFILE,c) < 0) {
	czseen = 1;   			/* If write error... */
	debug(F101,"putfil zchout write error, setting czseen","",1);
	return(-1);
    }
    return(0);
}

/*  G E T P K T -- Fill a packet data field  */

/*
 Gets characters from the current source -- file or memory string.
 Encodes the data into the packet, filling the packet optimally.
 Set first = 1 when calling for the first time on a given input stream
 (string or file).

 Uses global variables:
 t     -- current character.
 first -- flag: 1 to start up, 0 for input in progress, -1 for EOF.
 next  -- next character.
 data  -- the packet data buffer.
 size  -- number of characters in the data buffer.

Returns the size as value of the function, and also sets global size,
and fills (and null-terminates) the global data array.  Returns 0 upon eof.
*/

getpkt(maxsize) int maxsize; {		/* Fill one packet buffer */
    int i, x;				/* Loop index. */
	
    static char leftover[6] = { '\0', '\0', '\0', '\0', '\0', '\0' };

    if (first == 1) {		/* If first time thru...  */
	first = 0;		/* remember, */
	*leftover = '\0';   	/* discard any interrupted leftovers, */
	x = getchx(&t);		/* get first character of file into t, */
	if (x == 0) {	    	/* watching out for null file, */
	    first = 1;
	    return(size = 0);	
	}
    } else if (first == -1) {	/* EOF from last time? */
	first = 1;		/* Setup for next time. */
        return(size = 0);
    } else x = 1;

    /* Do any leftovers */

    for (size = 0; (data[size] = leftover[size]) != '\0'; size++)
    	;
    *leftover = '\0';

    /* Now fill up the rest of the packet. */

    rpt = 0;				/* Clear out any old repeat count. */
    while (x > 0) {			/* Until EOF... */
	x = getchx(&next);		/* Get next character for lookahead. */
	if (x == 0) first = -1;		/* Flag eof for next time. */
	osize = size;			/* Remember current position. */
        encode(t);			/* Encode the current character. */
	t = next;			/* Next is now current. */

	if (size == maxsize) { 		/* If the packet is exactly full, */
	    debug(F101,"getpkt exact fit","",size);
            return(size);		/* ... return. */
	}
	if (size > maxsize) {		/* If too big, save some for next. */
	    for (i = 0; (leftover[i] = data[osize+i]) != '\0'; i++)
	    	;
	    debug(F111,"getpkt leftover",leftover,size);
	    debug(F101," osize","",osize);
	    size = osize;		/* Return truncated packet. */
	    data[size] = '\0';
	    return(size);
	}
    }					/* Otherwise, keep filling. */
    debug(F111,"getpkt eof/eot",data,size); /* Fell thru before packet full, */
    return(size);		   /* return partially filled last packet. */
}

/*  G E T C H X  --  Get the next character from file (or pipe). */
 
/*
 On systems like Unix, the Macintosh, etc, that use a single character
 (NLCHAR, defined in ckcdeb.h) to separate lines in text files, and
 when in text/ascii mode (binary == 0), this function maps the newline
 character to CRLF.  If NLCHAR is not defined, then this mapping is
 not done, even in text mode.

 Returns 1 on success with ch set to the character, or 0 on failure (EOF)
*/
getchx(ch) char *ch; {			/* Get next character */
    int x; CHAR a;			/* The character to return. */
    static int b = 0;			/* A character to remember. */
    
    if (b > 0) {			/* Do we have a LF saved? */
	b = 0;				/* Yes, return that. */
	*ch = LF;
	return(1);
    }

    if (memstr)				/* Try to get the next character */
    	x = ((a = *memptr++) == '\0');	/* from the appropriate source, */
    else				/* memory or the current file. */
    	x = (zchin(ZIFILE,&a) == -1);

    if (x)
    	return(0);			/* No more, return 0 for EOF. */
    else {				/* Otherwise, read the next char. */
	ffc++, tfc++;			/* Count it. */
#ifdef NLCHAR
	if (!binary && (a == NLCHAR)) {	/* If nl and we must do nl-CRLF */
	    b = 1;			/* mapping, remember a linefeed, */
	    *ch = CR;			/* and return a carriage return. */
	    return(1);
	} else {
	    *ch = a;			/*  General case, return the char. */
	    return(1);	
        }
#else
        *ch = a;
        return(1);	
#endif
    }
}


/*  C A N N E D  --  Check if current file transfer cancelled */

canned(buf) char *buf; {
    if (*buf == 'X') cxseen = 1;
    if (*buf == 'Z') czseen = 1;
    debug(F101,"canned: cxseen","",cxseen);
    debug(F101," czseen","",czseen);
    return((czseen || cxseen) ? 1 : 0);
}

/*  T I N I T  --  Initialize a transaction  */

tinit() {
    xflg = 0;				/* Reset x-packet flag */
    memstr = 0;				/* Reset memory-string flag */
    memptr = NULL;			/*  and pointer */
    bctu = 1;				/* Reset block check type to 1 */
    ebq = ebqflg = 0;			/* Reset 8th-bit quoting stuff */
    if (savmod) {			/* If binary file mode was saved, */
    	binary = 1;			/*  restore it, */
	savmod = 0;			/*  unsave it. */
    }
    filcnt = 0;				/* Reset file counter */
    tfc = tlci = tlco = 0;		/* Reset character counters */
    prvpkt = -1;			/* Reset packet number */
    pktnum = 0;
    cxseen = czseen = 0;		/* Reset interrupt flags */
    *filnam = '\0';			/* Clear file name */
    *sndpkt = '\0';			/* Clear retransmission buffer */
    if (server) 			/* If acting as server, */
	timint = 30;			/* Use 30 second timeout, */
}


/*  R I N I T  --  Respond to S packet  */

rinit(d) char *d; {
    char *tp;
    ztime(&tp);
    tlog(F110,"Transaction begins",tp,0l); /* Make transaction log entry */
    tfc = tlci = tlco = 0;
    spar(d);
    rpar(d);
    ack1(d);
}

/*  S I N I T  --  Make sure file exists, then send Send-Init packet */

sinit() {
    int x; char *tp;

    sndsrc = nfils;			/* Where to look for files to send */
    ztime(&tp);
    tlog(F110,"Transaction begins",tp,0l); /* Make transaction log entry */
    debug(F101,"sinit: sndsrc","",sndsrc);
    if (sndsrc < 0) {			/* Must expand from 'send' command */
	nfils = zxpand(cmarg);		/* Look up literal name. */
	if (nfils < 0) {
	    screen(SCR_EM,0,0l,"Too many files");
	    return(0);
        } else if (nfils == 0) {	/* If none found, */
	    char xname[100];		/* convert the name. */
	    zrtol(cmarg,xname);
	    nfils = zxpand(xname); 	/* Look it up again. */
	}
	if (nfils < 1) {		/* If no match, report error. */
	    if (server) 
	    	errpkt("File not found");
	    else
		screen(SCR_EM,0,0l,"File not found");
	    return(0);
	}
	x = gnfile();			/* Position to first file. */
	if (x < 1) {
	    if (!server) 
	    	screen(SCR_EM,0,0l,"No readable file to send");
            else
	    	errpkt("No readable file to send");
	    return(0);
    	} 
    } else if (sndsrc > 0) {		/* Command line arglist -- */
	x = gnfile();			/* Get the first file from it. */
	if (x < 1) return(0);		/* (if any) */
    } else if (sndsrc == 0) {		/* stdin or memory always exist... */
	if ((cmarg2 != NULL) && (*cmarg2)) {
	    strcpy(filnam,cmarg2);	/* If F packet, "as" name is used */
	    cmarg2 = "";		/* if provided, */
        } else				/* otherwise */
	    strcpy(filnam,"stdin");	/* just use this. */
    }
    debug(F101,"sinit: nfils","",nfils);
    debug(F110," filnam",filnam,0);
    debug(F110," cmdstr",cmdstr,0);
    ttflui();				/* Flush input buffer. */
    if (!local && !server) sleep(delay);
    sipkt('S');				/* Send the Send-Init packet. */
    return(1);
}
sipkt(c) char c; {			/* Send S or I packet. */
    int x;
    ttflui();				/* Flush pending input. */
    x = rpar(data);			/* Send an I-Packet. */
    spack(c,pktnum,x,data);
}

/*  R C V F I L -- Receive a file  */

rcvfil() {
    int x;
    ffc = flci = flco = 0;		/* Init per-file counters */
    srvptr = srvcmd;			/* Decode file name from packet. */
    decode(data,putsrv);
    if (*srvcmd == '\0')		/* Watch out for null F packet. */
    	strcpy(srvcmd,"NONAME");
    screen(SCR_FN,0,0l,srvcmd);		/* Put it on screen */
    tlog(F110,"Receiving",srvcmd,0l);	/* Transaction log entry */
    if (cmarg2 != NULL) {               /* Check for alternate name */
        if (*cmarg2 != '\0') {
            strcpy(srvcmd,cmarg2);	/* Got one, use it. */
	    *cmarg2 = '\0';
        }
    }
    x = openo(srvcmd,filnam);		/* Try to open it */
    if (x) {
	tlog(F110," as",filnam,0l);
	screen(SCR_AN,0,0l,filnam);
	intmsg(++filcnt);
    } else {
        tlog(F110,"Failure to open",filnam,0l);
	screen(SCR_EM,0,0l,"Can't open file");
    }
    return(x);				/* Pass on return code from openo */
}

/*  R E O F  --  Receive End Of File  */

reof() {
    int x;
    if (cxseen == 0) cxseen = (*data == 'D');	/* Got discard directive? */
    x = clsof(cxseen | czseen);
    if (cxseen || czseen) {
	tlog(F100," *** Discarding","",0l);
	cxseen = 0;
    } else
	fstats();
    return(x);
}


/*  R E O T  --  Receive End Of Transaction  */

reot() {
    cxseen = czseen = 0;		/* Reset interruption flags */
    tstats();
}

/*  S F I L E -- Send File header or teXt header packet  */

/*  Call with x nonzero for X packet, zero for F packet  */
/*  Returns 1 on success, 0 on failure                   */