www.pudn.com > C中MODEM的开发.zip > ZM.C
/*
* Z M . C
* ZMODEM protocol primitives
* 8-16-86 Chuck Forsberg Omen Technology Inc
*
* Entry point Functions:
* zsbhdr(type, hdr) send binary header
* zshhdr(type, hdr) send hex header
* zgethdr(hdr, eflag) receive header - binary or hex
* zsdata(buf, len, frameend) send data
* zrdata(buf, len) receive data
* stohdr(pos) store position data in Txhdr
* long rclhdr(hdr) recover position offset from header
*/
#ifndef CANFDX
#include "zmodem.h"
int Rxtimeout = 100; /* Tenths of seconds to wait for something */
#endif
static char *frametypes[] = {
"Carrier Lost", /* -3 */
"TIMEOUT", /* -2 */
"ERROR", /* -1 */
#define FTOFFSET 3
"ZRQINIT",
"ZRINIT",
"ZSINIT",
"ZACK",
"ZFILE",
"ZSKIP",
"ZNAK",
"ZABORT",
"ZFIN",
"ZRPOS",
"ZDATA",
"ZEOF",
"ZFERR",
"ZCRC",
"ZCHALLENGE",
"ZCOMPL",
"ZCAN",
"ZFREECNT",
"ZCOMMAND",
"ZSTDERR",
"xxxxx"
#define FRTYPES 22 /* Total number of frame types in this array */
/* not including psuedo negative entries */
};
/* Send ZMODEM binary header hdr of type type */
zsbhdr(type, hdr)
register char *hdr;
{
register n;
register unsigned short crc;
vfile("zsbhdr: %s %lx", frametypes[type+FTOFFSET], rclhdr(hdr));
if (type == ZDATA)
for (n = Znulls; --n >=0; )
zsendline(0);
xsendline(ZPAD); xsendline(ZDLE); xsendline(ZBIN);
zsendline(type); crc = updcrc(type, 0);
for (n=4; --n >= 0;) {
zsendline(*hdr);
crc = updcrc((0377& *hdr++), crc);
}
crc = updcrc(0,updcrc(0,crc));
zsendline(crc>>8);
zsendline(crc);
if (type != ZDATA)
flushmo();
}
/* Send ZMODEM HEX header hdr of type type */
zshhdr(type, hdr)
register char *hdr;
{
register n;
register unsigned short crc;
vfile("zshhdr: %s %lx", frametypes[type+FTOFFSET], rclhdr(hdr));
sendline(ZPAD); sendline(ZPAD); sendline(ZDLE); sendline(ZHEX);
zputhex(type);
crc = updcrc(type, 0);
for (n=4; --n >= 0;) {
zputhex(*hdr); crc = updcrc((0377& *hdr++), crc);
}
crc = updcrc(0,updcrc(0,crc));
zputhex(crc>>8); zputhex(crc);
/* Make it printable on remote machine */
sendline(015); sendline(012);
/*
* Uncork the remote in case a fake XOFF has stopped data flow
*/
if (type != ZFIN)
sendline(021);
flushmo();
}
/*
* Send binary array buf of length length, with ending ZDLE sequence frameend
*/
zsdata(buf, length, frameend)
register char *buf;
{
register unsigned short crc;
vfile("zsdata: length=%d end=%x", length, frameend);
crc = 0;
for (;--length >= 0;) {
zsendline(*buf);
crc = updcrc((0377& *buf++), crc);
}
xsendline(ZDLE); xsendline(frameend);
crc = updcrc(frameend, crc);
crc = updcrc(0,updcrc(0,crc));
zsendline(crc>>8);
zsendline(crc);
if (frameend == ZCRCW) {
xsendline(XON); flushmo();
}
}
/*
* Receive array buf of max length with ending ZDLE sequence
* and CRC. Returns the ending character or error code.
*/
zrdata(buf, length)
register char *buf;
{
register c;
register unsigned short crc;
register d;
crc = Rxcount = 0;
for (;;) {
if ((c = zdlread()) & ~0377) {
crcfoo:
switch (c) {
case GOTCRCE:
case GOTCRCG:
case GOTCRCQ:
case GOTCRCW:
crc = updcrc((d=c)&0377, crc);
if ((c = zdlread()) & ~0377)
goto crcfoo;
crc = updcrc(c, crc);
if ((c = zdlread()) & ~0377)
goto crcfoo;
crc = updcrc(c, crc);
if (crc & 0xFFFF) {
zperr("Bad data CRC %x", crc);
return ERROR;
}
vfile("zrdata: cnt = %d ret = %x", Rxcount, d);
return d;
case GOTCAN:
zperr("ZMODEM: Sender Canceled");
return ZCAN;
case TIMEOUT:
zperr("ZMODEM data TIMEOUT");
return c;
default:
zperr("ZMODEM bad data subpacket ret=%x", c);
return c;
}
}
if (--length < 0) {
zperr("ZMODEM data subpacket too long");
return ERROR;
}
++Rxcount;
*buf++ = c;
crc = updcrc(c, crc);
continue;
}
}
/*
* Read a ZMODEM header to hdr, either binary or hex.
* eflag controls local display of non zmodem characters:
* 0: no display
* 1: display printing characters only
* 2: display all non ZMODEM characters
* On success, set Zmodem to 1 and return type of header.
* Otherwise return negative on error
*/
zgethdr(hdr, eflag)
char *hdr;
{
register c, n, cancount;
n = Baudrate; /* Max characters before start of frame */
cancount = 5;
again:
Rxframeind = Rxtype = 0;
switch (c = noxread7()) {
case RCDO:
case TIMEOUT:
goto fifi;
case CAN:
if (--cancount <= 0) {
c = ZCAN; goto fifi;
}
/* **** FALL THRU TO **** */
default:
agn2:
if ( --n == 0) {
zperr("ZMODEM Garbage count exceeded");
return(ERROR);
}
if (eflag && ((c &= 0177) & 0140))
bttyout(c);
else if (eflag > 1)
bttyout(c);
if (c != CAN)
cancount = 5;
goto again;
case ZPAD: /* This is what we want. */
break;
}
cancount = 5;
splat:
switch (c = noxread7()) {
case ZPAD:
goto splat;
case RCDO:
case TIMEOUT:
goto fifi;
default:
goto agn2;
case ZDLE: /* This is what we want. */
break;
}
switch (c = noxread7()) {
case RCDO:
case TIMEOUT:
goto fifi;
case ZBIN:
Rxframeind = ZBIN;
c = zrbhdr(hdr);
break;
case ZHEX:
Rxframeind = ZHEX;
c = zrhhdr(hdr);
break;
case CAN:
if (--cancount <= 0) {
c = ZCAN; goto fifi;
}
goto agn2;
default:
goto agn2;
}
Rxpos = hdr[ZP3] & 0377;
Rxpos = (Rxpos<<8) + (hdr[ZP2] & 0377);
Rxpos = (Rxpos<<8) + (hdr[ZP1] & 0377);
Rxpos = (Rxpos<<8) + (hdr[ZP0] & 0377);
fifi:
switch (c) {
case GOTCAN:
c = ZCAN;
/* **** FALL THRU TO **** */
case ZNAK:
case ZCAN:
case ERROR:
case TIMEOUT:
case RCDO:
zperr("ZMODEM: Got %s %s", frametypes[c+FTOFFSET],
(c >= 0) ? "header" : "error");
/* **** FALL THRU TO **** */
default:
if (c >= -3 && c <= FRTYPES)
vfile("zgethdr: %s %lx", frametypes[c+FTOFFSET], Rxpos);
else
vfile("zgethdr: %d %lx", c, Rxpos);
}
return c;
}
/* Receive a binary style header (type and position) */
zrbhdr(hdr)
register char *hdr;
{
register c, n;
register unsigned short crc;
if ((c = zdlread()) & ~0377)
return c;
Rxtype = c;
crc = updcrc(c, 0);
for (n=4; --n >= 0;) {
if ((c = zdlread()) & ~0377)
return c;
crc = updcrc(c, crc);
*hdr++ = c;
}
if ((c = zdlread()) & ~0377)
return c;
crc = updcrc(c, crc);
if ((c = zdlread()) & ~0377)
return c;
crc = updcrc(c, crc);
if (crc & 0xFFFF) {
zperr("Bad Header CRC"); return ERROR;
}
Zmodem = 1;
return Rxtype;
}
/* Receive a hex style header (type and position) */
zrhhdr(hdr)
char *hdr;
{
register c;
register unsigned short crc;
register n;
if ((c = zgethex()) < 0)
return c;
Rxtype = c;
crc = updcrc(c, 0);
for (n=4; --n >= 0;) {
if ((c = zgethex()) < 0)
return c;
crc = updcrc(c, crc);
*hdr++ = c;
}
if ((c = zgethex()) < 0)
return c;
crc = updcrc(c, crc);
if ((c = zgethex()) < 0)
return c;
crc = updcrc(c, crc);
if (crc & 0xFFFF) {
zperr("Bad Header CRC"); return ERROR;
}
if (readline(1) == '\r') /* Throw away possible cr/lf */
readline(1);
Zmodem = 1; return Rxtype;
}
/* Send a byte as two hex digits */
zputhex(c)
register c;
{
static char digits[] = "0123456789abcdef";
if (Verbose>4)
vfile("zputhex: %x", c);
sendline(digits[(c&0xF0)>>4]);
sendline(digits[(c)&0xF]);
}
/*
* Send character c with ZMODEM escape sequence encoding.
* Escape XON, XOFF. Escape CR following @ (Telenet net escape)
*/
zsendline(c)
register c;
{
static lastsent;
switch (c & 0377) {
case ZDLE:
xsendline(ZDLE);
xsendline (lastsent = (c ^= 0100));
break;
case 015:
case 0215:
if ((lastsent & 0177) != '@')
goto sendit;
/* **** FALL THRU TO **** */
case 020:
case 021:
case 023:
case 0220:
case 0221:
case 0223:
#ifdef ZKER
if (Zctlesc<0)
goto sendit;
#endif
xsendline(ZDLE);
c ^= 0100;
sendit:
xsendline(lastsent = c);
break;
default:
#ifdef ZKER
if (Zctlesc>0 && ! (c & 0140)) {
xsendline(ZDLE);
c ^= 0100;
}
#endif
xsendline(lastsent = c);
}
}
/* Decode two lower case hex digits into an 8 bit byte value */
zgethex()
{
register c;
c = zgeth1();
if (Verbose>4)
vfile("zgethex: %x", c);
return c;
}
zgeth1()
{
register c, n;
if ((c = noxread7()) < 0)
return c;
n = c - '0';
if (n > 9)
n -= ('a' - ':');
if (n & ~0xF)
return ERROR;
if ((c = noxread7()) < 0)
return c;
c -= '0';
if (c > 9)
c -= ('a' - ':');
if (c & ~0xF)
return ERROR;
c += (n<<4);
return c;
}
/*
* Read a byte, checking for ZMODEM escape encoding
* including CAN*5 which represents a quick abort
*/
zdlread()
{
register c;
if ((c = readline(Rxtimeout)) != ZDLE)
return c;
if ((c = readline(Rxtimeout)) < 0)
return c;
if (c == CAN && (c = readline(Rxtimeout)) < 0)
return c;
if (c == CAN && (c = readline(Rxtimeout)) < 0)
return c;
if (c == CAN && (c = readline(Rxtimeout)) < 0)
return c;
switch (c) {
case CAN:
return GOTCAN;
case ZCRCE:
case ZCRCG:
case ZCRCQ:
case ZCRCW:
return (c | GOTOR);
case ZRUB0:
return 0177;
case ZRUB1:
return 0377;
default:
if ((c & 0140) == 0100)
return (c ^ 0100);
break;
}
zperr("Got bad ZMODEM escape sequence %x", c);
return ERROR;
}
/*
* Read a character from the modem line with timeout.
* Eat parity, XON and XOFF characters.
*/
noxread7()
{
register c;
for (;;) {
if ((c = readline(Rxtimeout)) < 0)
return c;
switch (c &= 0177) {
case XON:
case XOFF:
continue;
default:
return c;
}
}
}
/* Store long integer pos in Txhdr */
stohdr(pos)
long pos;
{
Txhdr[ZP0] = pos;
Txhdr[ZP1] = pos>>8;
Txhdr[ZP2] = pos>>16;
Txhdr[ZP3] = pos>>24;
}
/* Recover a long integer from a header */
long
rclhdr(hdr)
register char *hdr;
{
register long l;
l = (hdr[ZP3] & 0377);
l = (l << 8) | (hdr[ZP2] & 0377);
l = (l << 8) | (hdr[ZP1] & 0377);
l = (l << 8) | (hdr[ZP0] & 0377);
return l;
}