/*****************************************************************************
 *
 * $Id$
 * Purpose ...............: Zmodem sender
 *
 *****************************************************************************
 * Copyright (C) 1997-2004
 *   
 * Michiel Broek		FIDO:	2:280/2802
 * Beekmansbos 10
 * 1971 BV IJmuiden
 * the Netherlands
 *
 * This file is part of MBSE BBS.
 *
 * This BBS is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * MBSE BBS is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with MBSE BBS; see the file COPYING.  If not, write to the Free
 * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *****************************************************************************/

#include "../config.h"
#include "../lib/mbselib.h"
#include "ttyio.h"
#include "zmmisc.h"
#include "transfer.h"
#include "openport.h"


static int initsend(void);
static int sendzfile(char*);
static int finsend(void);

static int getzrxinit(void);
static int sendzsinit(void);
static int zfilbuf(void);
static int zsendfile(char*,int);
static int zsendfdata(void);
static int getinsync(int);
void initzsendmsk(char *);

static FILE *in;
static int Eofseen;		/* EOF seen on input set by zfilbuf */
static int Rxflags = 0;
static int Wantfcs32=TRUE;	/* Want to send 32 bit FCS */
static int Rxbuflen;
static unsigned Txwindow;	/* Control the size of the transmitted window */
static unsigned Txwspac;	/* Spacing between zcrcq requests */
static unsigned Txwcnt;		/* Counter used to space ack requests */
static int blklen = 128;	/* Length of transmitted records */
static int blkopt;		/* Override value for zmodem blklen */
static int errors;
static int Lastsync;
static long bytcnt;
static int Lrxpos=0;
static int Lztrans=0;
static int Lzmanag=0;
static int Lskipnocor=0;
static int Lzconv=0;
static int Beenhereb4;
static char Myattn[]={0};
static long skipsize;
struct timeval	starttime, endtime;
struct timezone	tz;

extern unsigned long	sentbytes;
extern int Rxhlen;

extern char *txbuf;
extern char *frametypes[];

extern unsigned	Baudrate;


int zmsndfiles(down_list *lst)
{
    int		rc, maxrc = 0;
    down_list	*tmpf;

    Syslog('+', "Zmodem: start Zmodem send");

    get_frame_buffer();

    if ((rc = initsend())) {
	if (txbuf)
	    free(txbuf);
	txbuf = NULL;
	free_frame_buffer();
	return abs(rc);
    }

    for (tmpf = lst; tmpf && (maxrc < 2); tmpf = tmpf->next) {
	if (tmpf->remote) {
	    rc = sendzfile(tmpf->remote);
	    rc = abs(rc);
	    if (rc > maxrc) 
		maxrc = rc;
	    if (rc == 0) {
		tmpf->sent = TRUE;
	    } else {
		tmpf->failed = TRUE;
	    }
	} else if (maxrc == 0) {
	    tmpf->failed = TRUE;
	}
	Syslog('z', "zmsndfiles: unlink(%s) returns %d", tmpf->remote, unlink(tmpf->remote));
    }

    if (maxrc < 2) {
	rc = finsend();
	rc = abs(rc);
    }

    if (rc > maxrc) 
	maxrc = rc;

    if (txbuf)
	free(txbuf);
    txbuf = NULL;
    free_frame_buffer();
    io_mode(0, 1);

    Syslog('z', "Zmodem: send rc=%d", maxrc);
    return (maxrc < 2)?0:maxrc;
}



static int initsend(void)
{
    Syslog('z', "Zmodem: initsend");

    io_mode(0, 1);
    PUTSTR((char *)"rz\r");
    stohdr(0L);
    zshhdr(ZRQINIT, Txhdr);

    if (getzrxinit()) {
	Syslog('+', "Zmodem: Unable to initiate send");
	return 1;
    }

    return 0;
}



/*
 * Say "bibi" to the receiver, try to do it cleanly
 */
static int finsend(void)
{
    int i, rc = 0;

    Syslog('z', "Zmodem: finsend");
    while (GETCHAR(1) >= 0) /*nothing*/;
    for (i = 0; i < 30; i++) {
	stohdr(0L);
	zshhdr(ZFIN, Txhdr);
	if ((rc = zgethdr(Rxhdr)) == ZFIN)
	    PUTSTR((char *)"OO");
	if ((rc == ZFIN) || (rc == ZCAN) || (rc < 0)) 
	    break;
    }
    return (rc != ZFIN);
}



static int sendzfile(char *rn)
{
    int		    rc = 0;
    struct stat	    st;
    struct flock    fl;
    int		    bufl;
    int		    sverr;

    fl.l_type   = F_RDLCK;
    fl.l_whence = 0;
    fl.l_start  = 0L;
    fl.l_len    = 0L;
    if (txbuf == NULL) 
	txbuf = malloc(MAXBLOCK);

    skipsize = 0L;
    if ((in = fopen(rn, "r")) == NULL) {
	sverr = errno;
	if ((sverr == ENOENT) || (sverr == EINVAL)) {
	    Syslog('+', "File %s doesn't exist, removing", MBSE_SS(rn));
	    return 0;
	} else {
	    WriteError("$Zmodem: cannot open file %s, skipping", MBSE_SS(rn));
	    return 1;
	}
    }

    if (stat(rn,&st) != 0) {
	Syslog('+', "$Zmodem: cannot access \"%s\", skipping",MBSE_SS(rn));
	fclose(in);
	return 1;
    }

    Syslog('+', "Zmodem: send \"%s\"", MBSE_SS(rn));
    Syslog('+', "Zmodem: size %lu bytes, dated %s", (unsigned long)st.st_size, rfcdate(st.st_mtime));
    gettimeofday(&starttime, &tz);

    sprintf(txbuf,"%s %lu %lo %o 0 0 0", rn,(unsigned long)st.st_size, st.st_mtime+(st.st_mtime%2), st.st_mode);
    bufl = strlen(txbuf);
    *(strchr(txbuf,' ')) = '\0'; /*hope no blanks in filename*/

    Eofseen = 0;
    rc = zsendfile(txbuf,bufl);
    if (rc == ZSKIP) {
	Syslog('+', "Zmodem: remote skipped %s, is OK",MBSE_SS(rn));
	return 0;
    } else if ((rc == OK) && (st.st_size - skipsize)) {
	gettimeofday(&endtime, &tz);
	Syslog('+', "Zmodem: OK %s", transfertime(starttime, endtime, (unsigned long)st.st_size - skipsize, TRUE));
	sentbytes += (unsigned long)st.st_size - skipsize;
	return 0;
    } else 
	return 2;
}



/*
 * Get the receiver's init parameters
 */
int getzrxinit(void)	// CHECKED BUT NOT WELL TESTED
{
    int	n;

    Syslog('z', "getzrxinit");
    for (n=10; --n>=0; ) {
		
	switch (zgethdr(Rxhdr)) {
	    case ZCHALLENGE:	/* Echo receiver's challenge numbr */
			stohdr(Rxpos);
			zshhdr(ZACK, Txhdr);
			continue;
	    case ZCOMMAND:		/* They didn't see out ZRQINIT */
			/* A receiver cannot send a command */
			continue;
	    case ZRINIT:
			Rxflags = 0377 & Rxhdr[ZF0];
			Txfcs32 = (Wantfcs32 && (Rxflags & CANFC32));
			Zctlesc |= Rxflags & TESCCTL;
			
			Rxbuflen = (0377 & Rxhdr[ZP0])+((0377 & Rxhdr[ZP1])<<8);
			if ( !(Rxflags & CANFDX))
			    Txwindow = 0;
			Syslog('z', "Zmodem: Remote allowed Rxbuflen=%d", Rxbuflen);
			io_mode(0, 2); /* Set cbreak, XON/XOFF, etc. */

			/* Set initial subpacket length */
			if (blklen < 1024) {	/* Command line override? */
			    if (Baudrate > 300)
				blklen = 256;
			    if (Baudrate > 1200)
				blklen = 512;
			    if (Baudrate  > 2400)
				blklen = 1024;
			}
			if (Rxbuflen && blklen>Rxbuflen)
			    blklen = Rxbuflen;
			if (blkopt && blklen > blkopt)
			    blklen = blkopt;
			Syslog('z', "Rxbuflen=%d blklen=%d", Rxbuflen, blklen);
			Syslog('z', "Txwindow = %u Txwspac = %d", Txwindow, Txwspac);

			Lztrans = 0;

			return (sendzsinit());
	    case ZCAN:
	    case TIMEOUT:
			return TERROR;
	    case HANGUP:
			return HANGUP;
	    case ZRQINIT:
			if (Rxhdr[ZF0] == ZCOMMAND)
			    continue;
	    default:
			zshhdr(ZNAK, Txhdr);
			continue;
	}
    }
    return TERROR;
}



/*
 * Send send-init information
 */
int sendzsinit(void)
{
    int	c;

    if (Myattn[0] == '\0' && (!Zctlesc || (Rxflags & TESCCTL)))
	return OK;
    errors = 0;
    for (;;) {
	stohdr(0L);
	if (Zctlesc) {
	    Txhdr[ZF0] |= TESCCTL; zshhdr(ZSINIT, Txhdr);
	} else
	    zsbhdr(ZSINIT, Txhdr);
	zsdata(Myattn, ZATTNLEN, ZCRCW);
	c = zgethdr(Rxhdr);
	switch (c) {
	    case ZCAN:	    return TERROR;
	    case HANGUP:    return HANGUP;
	    case ZACK:	    return OK;
	    default:	    if (++errors > 19)
				return TERROR;
			    continue;
	}
    }
}



/*
 * Fill buffer with blklen chars
 */
int zfilbuf(void)
{
    int n;

    n = fread(txbuf, 1, blklen, in);
    if (n < blklen) {
	Eofseen = 1;
	Syslog('z', "zfilbuf return %d", n);
    }

    return n;
}



/*
 * Send file name and related info
 */
int zsendfile(char *buf, int blen)
{
    int	c;
    register unsigned long crc = -1;
    long lastcrcrq = -1;

    Syslog('z', "zsendfile %s (%d)", buf, blen);
    for (errors=0; ++errors<11;) {
	Txhdr[ZF0] = Lzconv;	/* file conversion request */
	Txhdr[ZF1] = Lzmanag;	/* file management request */
	if (Lskipnocor)
	    Txhdr[ZF1] |= ZMSKNOLOC;
	Txhdr[ZF2] = Lztrans;	/* file transport request */
	Txhdr[ZF3] = 0;
	zsbhdr(ZFILE, Txhdr);
	zsdata(buf, blen, ZCRCW);
again:
	c = zgethdr(Rxhdr);
	switch (c) {
	    case ZRINIT:
			while ((c = GETCHAR(5)) > 0)
			    if (c == ZPAD) {
				goto again;
			    }
			continue;
	    case ZRQINIT:
			Syslog('+', "got ZRQINIT, a zmodem sender talks to this sender");
			return TERROR;
	    case ZCAN:
	    case TIMEOUT:
	    case ZABORT:
	    case ZFIN:
			Syslog('+', "Zmodem: Got %s on pathname", frametypes[c+FTOFFSET]);
			return TERROR;
	    default:
			Syslog('+', "Zmodem: Got %d frame type on pathname", c);
			continue;
	    case TERROR:
	    case ZNAK:
			continue;
	    case ZCRC:
			if (Rxpos != lastcrcrq) {
			    lastcrcrq = Rxpos;
			    crc = 0xFFFFFFFFL;
			    fseek(in, 0L, 0);
			    while (((c = getc(in)) != EOF) && --lastcrcrq)
				crc = updcrc32(c, crc);
			    crc = ~crc;
			    clearerr(in);	/* Clear possible EOF */
			    lastcrcrq = Rxpos;
			}
			stohdr(crc);
			zsbhdr(ZCRC, Txhdr);
			goto again;
	    case ZFERR:
	    case ZSKIP:
			Syslog('+', "Zmodem: File skipped by receiver request");
			fclose(in); return c;
	    case ZRPOS:
			/*
			 * Suppress zcrcw request otherwise triggered by
			 * lastyunc==bytcnt
			 */
			if (Rxpos > 0)
			    skipsize = Rxpos;
			if (fseek(in, Rxpos, 0))
			    return TERROR;
			Lastsync = (bytcnt = Txpos = Lrxpos = Rxpos) -1;
			return zsendfdata();
	}
    }
    fclose(in); return TERROR;
}



/* 
 * Send the data in the file
 */
int zsendfdata(void)
{
    int	    c = 0, e, n;
    int	    newcnt;
    int	    tcount = 0;
    int	    junkcount; /* Counts garbage chars received by TX */
    int	    maxblklen, goodblks = 0, goodneeded = 8;

    maxblklen = 1024; // FIXME: 8K variant set this to 8K
    Syslog('z', "zsendfdata() maxblklen=%d", maxblklen);

    junkcount = 0;
    Beenhereb4 = 0;
somemore:
    if (0) {
waitack:
	junkcount = 0;
	c = getinsync(0);
gotack:
	switch (c) {
	    default:
	    case ZCAN:	    fclose(in);
			    return TERROR;
	    case ZRINIT:    fclose(in);
			    return ZSKIP;
	    case ZSKIP:	    fclose(in);
			    return c;
	    case ZACK:	    break;	// Possible bug, added 23-08-99
	    case ZRPOS:	    blklen = ((blklen >> 2) > 64) ? (blklen >> 2) : 64;
			    goodblks = 0;
			    goodneeded = ((goodneeded << 1) > 16) ? 16 : goodneeded << 1;
			    Syslog('z', "zmsend: blocklen now %d", blklen);
			    break;
	    case TIMEOUT:   /* Put back here 08-09-1999 mb */
			    Syslog('z', "zmsend: zsendfdata TIMEOUT");
			    goto to;
	    case HANGUP:    /* New, added 08-09-1999 mb */
			    Syslog('z', "zmsend: zsendfdata HANGUP");
			    fclose(in);
			    return c;
	}

	/*
	 * If the reverse channel can be tested for data,
	 *  this logic may be used to detect error packets
	 *  sent by the receiver, in place of setjmp/longjmp
	 *  rdchk(fd) returns non 0 if a character is available
	 */
	if (TCHECK()) {
	    c = GETCHAR(1);
	    Syslog('z', "zsendfdata(): check getchar(1)=%d", c);
	    if (c < 0) {
		return c;
	    } else switch (c) {
		case CAN:
		case ZPAD:	c = getinsync(1);
				goto gotack;
		case XOFF:	/* Wait a while for an XON */
		case XOFF|0200:	GETCHAR(10);
	    }
	}
    }
to:
    newcnt = Rxbuflen;
    Txwcnt = 0;
    stohdr(Txpos);
    zsbhdr(ZDATA, Txhdr);

    do {
	n = zfilbuf();
	if (Eofseen)
	    e = ZCRCE;
	else if (junkcount > 3)
	    e = ZCRCW;
	else if (bytcnt == Lastsync)
	    e = ZCRCW;
	else if (Rxbuflen && (newcnt -= n) <= 0)
	    e = ZCRCW;
	else if (Txwindow && (Txwcnt += n) >= Txwspac) {
	    Txwcnt = 0;  e = ZCRCQ;
	} else
	    e = ZCRCG;
	Syslog('Z', "%7ld ZMODEM%s    ", Txpos, Crc32t?" CRC-32":"");
	Nopper();
	zsdata(txbuf, n, e);
	bytcnt = Txpos += n;

	if ((blklen < maxblklen) && (++goodblks > goodneeded)) {
	    blklen = ((blklen << 1) < maxblklen) ? blklen << 1 : maxblklen;
	    goodblks = 0;
	    Syslog('z', "zmsend: blocklen now %d", blklen);
	}

	if (e == ZCRCW)
	    goto waitack;
	/*
	 * If the reverse channel can be tested for data,
	 *  this logic may be used to detect error packets
	 *  sent by the receiver, in place of setjmp/longjmp
	 *  rdchk(fd) returns non 0 if a character is available
	 */
	if (TCHECK()) {
	    c = GETCHAR(1);
	    if (c < 0) {
		return c;
	    } else switch (c) {
		case CAN:
		case ZPAD:	c = getinsync(1);
				if (c == ZACK)
				    break;
				/* zcrce - dinna wanna starta ping-pong game */
				zsdata(txbuf, 0, ZCRCE);
				goto gotack;
		case XOFF:	/* Wait a while for an XON */
		case XOFF|0200: GETCHAR(10);
		default:	++junkcount;
	    }
	}
	if (Txwindow) {
	    while ((tcount = (Txpos - Lrxpos)) >= Txwindow) {
		Syslog('z', "%ld window >= %u", tcount, Txwindow);
		if (e != ZCRCQ)
		    zsdata(txbuf, 0, e = ZCRCQ);
		c = getinsync(1);
		if (c != ZACK) {
		    zsdata(txbuf, 0, ZCRCE);
		    goto gotack;
		}
	    }
	    Syslog('z', "window = %ld", tcount);
	}
    } while (!Eofseen);

    for (;;) {
	stohdr(Txpos);
	zsbhdr(ZEOF, Txhdr);
egotack:
	switch (getinsync(0)) {
	    case ZACK:	    Syslog('z', "zsendfdata() ZACK");
			    goto egotack;	// continue in old source
	    case ZRPOS:	    goto somemore;
	    case ZRINIT:    fclose(in);
			    return OK;
	    case ZSKIP:	    fclose(in);
			    Syslog('+', "Zmodem: File skipped by receiver request");
			    return ZSKIP;
	    default:	    Syslog('+', "Zmodem: Got %d trying to send end of file", c);
	    case TERROR:    fclose(in);
			    return TERROR;
	}
    }
}



/*
 * Respond to receiver's complaint, get back in sync with receiver
 */
int getinsync(int flag)
{
    int	c = 0;

    Syslog('z', "getinsync(%d)", flag);

    for (;;) {
	c = zgethdr(Rxhdr);
	switch (c) {
	    case HANGUP:    return HANGUP;
	    case ZCAN:
	    case ZABORT:
	    case ZFIN:
	    case TERROR:
	    case TIMEOUT:   Syslog('+', "Zmodem: Got %s sending data", frametypes[c+FTOFFSET]);
			    return TERROR;
	    case ZRPOS:	    /* ************************************* */
			    /*  If sending to a buffered modem, you  */
			    /*   might send a break at this point to */
			    /*   dump the modem's buffer.		 */
			    clearerr(in);	/* In case file EOF seen */
			    if (fseek(in, Rxpos, 0)) {
				Syslog('+', "Zmodem: Bad Seek to %ld", Rxpos);
				return TERROR;
			    }
			    Eofseen = 0;
			    bytcnt = Lrxpos = Txpos = Rxpos;
			    if (Lastsync == Rxpos) {
				if (++Beenhereb4 > 12) {
				    Syslog('+', "Zmodem: Can't send block");
				    return TERROR;
				}
				if (Beenhereb4 > 4) {
				    if (blklen > 32) {
					blklen /= 2;
					Syslog('z', "Zmodem: blocklen now %d", blklen);
				    }
				}
			    } else {
				Beenhereb4=0;
			    }
			    Lastsync = Rxpos;
			    return c;
	    case ZACK:	    Lrxpos = Rxpos;
			    if (flag || Txpos == Rxpos)
				return ZACK;
			    continue;
	    case ZRINIT:    return c;
	    case ZSKIP:	    Syslog('+', "Zmodem: File skipped by receiver request");
			    return c;
	    default:	    zsbhdr(ZNAK, Txhdr);
			    continue;
	}
    }
}



/*
 * Set additional control chars to mask in Zsendmask
 * according to bit array stored in char array at p
 */
void initzsendmsk(register char *p)
{
    int	c;

    for (c = 0; c < 33; ++c) {
        if (p[c>>3] & (1 << (c & 7))) {
            Zsendmask[c] = 1;
            Syslog('z', "Zmodem: Escaping %02o", c);
        }
    }
}