// Rz.cpp

#include "stdafx.h"
#include "Rzsz.h"
#include "Crctab.h"

/*
 * Initialize for Zmodem receive attempt, try to activate Zmodem sender
 *  Handles ZSINIT frame
 *  Return ZFILE if Zmodem filename received, -1 on error,
 *   ZCOMPL if transaction finished,  else 0
 */
int tryz(void)
{
	int c, n, cmdzack1flg;

	for (n=Zmodem?15:5; --n>=0; ) {
		/* Set buffer length (0) and capability flags */

		stohdr(0L);
		Txhdr[ZF0] = CANFC32|CANFDX|CANOVIO;
		if (Zctlesc)
			Txhdr[ZF0] |= TESCCTL;
		zshhdr(tryzhdrtype, Txhdr);
		if (tryzhdrtype == ZSKIP)	/* Don't skip too far */
			tryzhdrtype = ZRINIT;	/* CAF 8-21-87 */
again:
		switch (zgethdr(Rxhdr, 0)) {
		case ZRQINIT:
			continue;
		case ZEOF:
			continue;
		case TIMEOUT:
			continue;
		case ZFILE:
			zconv = Rxhdr[ZF0];
			zmanag = Rxhdr[ZF1];
			ztrans = Rxhdr[ZF2];
			tryzhdrtype = ZRINIT;
			c = zrdata(secbuf, 1024);
//			mode(3);
			if (c == GOTCRCW)
				return ZFILE;
			zshhdr(ZNAK, Txhdr);
			goto again;
		case ZSINIT:
			Zctlesc = TESCCTL & Rxhdr[ZF0];
			if (zrdata(Attn, ZATTNLEN) == GOTCRCW) {
				stohdr(1L);
				zshhdr(ZACK, Txhdr);
				goto again;
			}
			zshhdr(ZNAK, Txhdr);
			goto again;
		case ZFREECNT:
//			stohdr(getfree());
			zshhdr(ZACK, Txhdr);
			goto again;
		case ZCOMMAND:
			cmdzack1flg = Rxhdr[ZF0];
			if (zrdata(secbuf, 1024) == GOTCRCW) {
				if (cmdzack1flg & ZCACK1)
					stohdr(0L);
				else
//					stohdr((long)sys2(secbuf));
//				purgeline();	/* dump impatient questions */
				do {
					zshhdr(ZCOMPL, Txhdr);
				}
				while (++errors<20 && zgethdr(Rxhdr,1) != ZFIN);
				ackbibi();
//				if (cmdzack1flg & ZCACK1)
//					exec2(secbuf);
				return ZCOMPL;
			}
			zshhdr(ZNAK, Txhdr); goto again;
		case ZCOMPL:
			goto again;
		default:
			continue;
		case ZFIN:
			ackbibi(); return ZCOMPL;
		case ZCAN:
			return ZERR;
		}
	}
	return 0;
}

/*******************************************************/
/*
 * Receive 1 or more files with ZMODEM protocol
 */
int rzfiles(void)
{
	register c;

	for (;;) {
		switch (c = rzfile()) {
		case ZEOF:
		case ZSKIP:
		case ZFERR:
			switch (tryz()) {
			case ZCOMPL:
				return OK;
			default:
				return ZERR;
			case ZFILE:
				break;
			}
			continue;
		default:
			return c;
		case ERROR:
			return ZERR;
		}
	}
}

/********************************************************/
/*
 * Receive a file with ZMODEM protocol
 *  Assumes file name frame is in secbuf
 */
int rzfile(void)
{
	register c, n;
	long rxbytes;

	Eofseen=FALSE;
	if (procheader(secbuf) == ZERR) {
		return (tryzhdrtype = ZSKIP);
	}

	n = 20; rxbytes = 0l;

	for (;;) {
#ifdef SEGMENTS
		chinseg = 0;
#endif
		stohdr(rxbytes);
		zshhdr(ZRPOS, Txhdr);
nxthdr:
		switch (c = zgethdr(Rxhdr, 0)) {
		default:
//			vfile("rzfile: zgethdr returned %d", c);
			return ZERR;
		case ZNAK:
		case TIMEOUT:
#ifdef SEGMENTS
			putsec(secbuf, chinseg);
			chinseg = 0;
#endif
			if ( --n < 0) {
//				vfile("rzfile: zgethdr returned %d", c);
				return ZERR;
			}
			continue;
		case ZFILE:
			zrdata(secbuf, 1024);
			continue;
		case ZEOF:
#ifdef SEGMENTS
			putsec(secbuf, chinseg);
			chinseg = 0;
#endif
			if (rclhdr(Rxhdr) != rxbytes) {
				/*
				 * Ignore eof if it's at wrong place - force
				 *  a timeout because the eof might have gone
				 *  out before we sent our zrpos.
				 */
				errors = 0;  goto nxthdr;
			}
			if (closeit()) {
				tryzhdrtype = ZFERR;
//				vfile("rzfile: closeit returned <> 0");
				return ZERR;
			}
//			vfile("rzfile: normal EOF");
			return c;
		case ZERR:	/* Too much garbage in header search error */
#ifdef SEGMENTS
			putsec(secbuf, chinseg);
			chinseg = 0;
#endif
			if ( --n < 0) {
//				vfile("rzfile: zgethdr returned %d", c);
				return ZERR;
			}
			zmputs(Attn);
			continue;
		case ZSKIP:
#ifdef SEGMENTS
			putsec(secbuf, chinseg);
			chinseg = 0;
#endif
			closeit();
//			vfile("rzfile: Sender SKIPPED file");
			return c;
		case ZDATA:
			if (rclhdr(Rxhdr) != rxbytes) {
				if ( --n < 0) {
					return ZERR;
				}
#ifdef SEGMENTS
				putsec(secbuf, chinseg);
				chinseg = 0;
#endif
				zmputs(Attn);  continue;
			}
moredata:
			if (Verbose>1)
				fprintf(stderr, "\r%7ld ZMODEM%s    ",
				  rxbytes, Crc32?" CRC-32":"");
#ifdef SEGMENTS
			if (chinseg >= (1024 * SEGMENTS)) {
				putsec(secbuf, chinseg);
				chinseg = 0;
			}
			switch (c = zrdata(secbuf+chinseg, 1024))
#else
			switch (c = zrdata(secbuf, 1024))
#endif
			{
			case ZCAN:
#ifdef SEGMENTS
				putsec(secbuf, chinseg);
				chinseg = 0;
#endif
//				vfile("rzfile: zgethdr returned %d", c);
				return ZERR;
			case ERROR:	/* CRC error */
#ifdef SEGMENTS
				putsec(secbuf, chinseg);
				chinseg = 0;
#endif
				if ( --n < 0) {
//					vfile("rzfile: zgethdr returned %d", c);
					return ZERR;
				}
				zmputs(Attn);
				continue;
			case TIMEOUT:
#ifdef SEGMENTS
				putsec(secbuf, chinseg);
				chinseg = 0;
#endif
				if ( --n < 0) {
//					vfile("rzfile: zgethdr returned %d", c);
					return ZERR;
				}
				continue;
			case GOTCRCW:
				n = 20;
#ifdef SEGMENTS
				chinseg += Rxcount;
				putsec(secbuf, chinseg);
				chinseg = 0;
#else
				putsec(secbuf, Rxcount);
#endif
				rxbytes += Rxcount;
				stohdr(rxbytes);
				zshhdr(ZACK, Txhdr);
				sendline(XON);
				goto nxthdr;
			case GOTCRCQ:
				n = 20;
#ifdef SEGMENTS
				chinseg += Rxcount;
#else
				putsec(secbuf, Rxcount);
#endif
				rxbytes += Rxcount;
				stohdr(rxbytes);
				zshhdr(ZACK, Txhdr);
				goto moredata;
			case GOTCRCG:
				n = 20;
#ifdef SEGMENTS
				chinseg += Rxcount;
#else
				putsec(secbuf, Rxcount);
#endif
				rxbytes += Rxcount;
				goto moredata;
			case GOTCRCE:
				n = 20;
#ifdef SEGMENTS
				chinseg += Rxcount;
#else
				putsec(secbuf, Rxcount);
#endif
				rxbytes += Rxcount;
				goto nxthdr;
			}
		}
	}
}