minix3/commands/zmodem/zm.c

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2020-02-21 00:59:27 +05:30
/*
* Z M . C
* ZMODEM protocol primitives
* 05-09-88 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"
#endif
int Rxtimeout = 100; /* Tenths of seconds to wait for something */
#ifndef UNSL
#define UNSL
#endif
/* Globals used by ZMODEM functions */
int Rxframeind; /* ZBIN ZBIN32, or ZHEX type of frame received */
int Rxtype; /* Type of header received */
int Rxcount; /* Count of data bytes received */
char Rxhdr[4]; /* Received header */
char Txhdr[4]; /* Transmitted header */
long Rxpos; /* Received file position */
long Txpos; /* Transmitted file position */
int Txfcs32; /* TURE means send binary frames with 32 bit FCS */
int Crc32t; /* Display flag indicating 32 bit CRC being sent */
int Crc32; /* Display flag indicating 32 bit CRC being received */
int Znulls; /* Number of nulls to send at beginning of ZDATA hdr */
char Attn[ZATTNLEN+1]; /* Attention string rx sends to tx on err */
static int lastsent; /* Last char we sent */
static int Not8bit; /* Seven bits seen on header */
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 */
};
static char badcrc[] = "Bad CRC";
/* Send ZMODEM binary header hdr of type type */
void zsbhdr(int type, char *hdr)
{
register int n;
register unsigned short crc;
vfile("zsbhdr: %s %lx", frametypes[type+FTOFFSET], rclhdr(hdr));
if (type == ZDATA)
for (n = Znulls; --n >=0; )
xsendline(0);
xsendline(ZPAD); xsendline(ZDLE);
if ((Crc32t=Txfcs32))
zsbh32(hdr, type);
else {
xsendline(ZBIN); zsendline(type); crc = updcrc(type, 0);
for (n=4; --n >= 0; ++hdr) {
zsendline(*hdr);
crc = updcrc((0377& *hdr), crc);
}
crc = updcrc(0,updcrc(0,crc));
zsendline(crc>>8);
zsendline(crc);
}
if (type != ZDATA)
flushmo();
}
/* Send ZMODEM binary header hdr of type type */
void zsbh32(char *hdr, int type)
{
register int n;
register UNSL long crc;
xsendline(ZBIN32); zsendline(type);
crc = 0xFFFFFFFFL; crc = UPDC32(type, crc);
for (n=4; --n >= 0; ++hdr) {
crc = UPDC32((0377 & *hdr), crc);
zsendline(*hdr);
}
crc = ~crc;
for (n=4; --n >= 0;) {
zsendline((int)crc);
crc >>= 8;
}
}
/* Send ZMODEM HEX header hdr of type type */
void zshhdr(int type, char *hdr)
{
register int n;
register unsigned short crc;
vfile("zshhdr: %s %lx", frametypes[type+FTOFFSET], rclhdr(hdr));
sendline(ZPAD); sendline(ZPAD); sendline(ZDLE); sendline(ZHEX);
zputhex(type);
Crc32t = 0;
crc = updcrc(type, 0);
for (n=4; --n >= 0; ++hdr) {
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(0212);
/*
* Uncork the remote in case a fake XOFF has stopped data flow
*/
if (type != ZFIN && type != ZACK)
sendline(021);
flushmo();
}
/*
* Send binary array buf of length length, with ending ZDLE sequence frameend
*/
static char *Zendnames[] = { "ZCRCE", "ZCRCG", "ZCRCQ", "ZCRCW"};
void zsdata(char *buf, int length, int frameend)
{
register unsigned short crc;
vfile("zsdata: %d %s", length, Zendnames[(frameend-ZCRCE)&3]);
if (Crc32t)
zsda32(buf, length, frameend);
else {
crc = 0;
for (;--length >= 0; ++buf) {
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();
}
}
void zsda32(char *buf, int length, int frameend)
{
register int c;
register UNSL long crc;
crc = 0xFFFFFFFFL;
for (;--length >= 0; ++buf) {
c = *buf & 0377;
if (c & 0140)
xsendline(lastsent = c);
else
zsendline(c);
crc = UPDC32(c, crc);
}
xsendline(ZDLE); xsendline(frameend);
crc = UPDC32(frameend, crc);
crc = ~crc;
for (length=4; --length >= 0;) {
zsendline((int)crc); crc >>= 8;
}
}
/*
* Receive array buf of max length with ending ZDLE sequence
* and CRC. Returns the ending character or error code.
* NB: On errors may store length+1 bytes!
*/
int zrdata(char *buf, int length)
{
register int c;
register unsigned short crc;
register char *end;
register int d;
if (Rxframeind == ZBIN32)
return zrdat32(buf, length);
crc = Rxcount = 0; end = buf + length;
while (buf <= end) {
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(badcrc);
return ERROR;
}
Rxcount = length - (end - buf);
vfile("zrdata: %d %s", Rxcount,
Zendnames[(d-GOTCRCE)&3]);
return d;
case GOTCAN:
zperr("Sender Canceled");
return ZCAN;
case TIMEOUT:
zperr("TIMEOUT");
return c;
default:
zperr("Bad data subpacket");
return c;
}
}
*buf++ = c;
crc = updcrc(c, crc);
}
zperr("Data subpacket too long");
return ERROR;
}
int zrdat32(char *buf, int length)
{
register int c;
register UNSL long crc;
register char *end;
register int d;
crc = 0xFFFFFFFFL; Rxcount = 0; end = buf + length;
while (buf <= end) {
if ((c = zdlread()) & ~0377) {
crcfoo:
switch (c) {
case GOTCRCE:
case GOTCRCG:
case GOTCRCQ:
case GOTCRCW:
d = c; c &= 0377;
crc = UPDC32(c, crc);
if ((c = zdlread()) & ~0377)
goto crcfoo;
crc = UPDC32(c, crc);
if ((c = zdlread()) & ~0377)
goto crcfoo;
crc = UPDC32(c, crc);
if ((c = zdlread()) & ~0377)
goto crcfoo;
crc = UPDC32(c, crc);
if ((c = zdlread()) & ~0377)
goto crcfoo;
crc = UPDC32(c, crc);
if (crc != 0xDEBB20E3) {
zperr(badcrc);
return ERROR;
}
Rxcount = length - (end - buf);
vfile("zrdat32: %d %s", Rxcount,
Zendnames[(d-GOTCRCE)&3]);
return d;
case GOTCAN:
zperr("Sender Canceled");
return ZCAN;
case TIMEOUT:
zperr("TIMEOUT");
return c;
default:
zperr("Bad data subpacket");
return c;
}
}
*buf++ = c;
crc = UPDC32(c, crc);
}
zperr("Data subpacket too long");
return ERROR;
}
/*
* 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, set Rxpos and return type of header.
* Otherwise return negative on error.
* Return ERROR instantly if ZCRCW sequence, for fast error recovery.
*/
int zgethdr(char *hdr, int eflag)
{
register int c, n, cancount;
n = Zrwindow + Baudrate; /* Max bytes before start of frame */
Rxframeind = Rxtype = 0;
startover:
cancount = 5;
again:
/* Return immediate ERROR if ZCRCW sequence seen */
switch (c = readline(Rxtimeout)) {
case RCDO:
case TIMEOUT:
goto fifi;
case CAN:
gotcan:
if (--cancount <= 0) {
c = ZCAN; goto fifi;
}
switch (c = readline(1)) {
case TIMEOUT:
goto again;
case ZCRCW:
c = ERROR;
/* **** FALL THRU TO **** */
case RCDO:
goto fifi;
default:
break;
case CAN:
if (--cancount <= 0) {
c = ZCAN; goto fifi;
}
goto again;
}
/* **** FALL THRU TO **** */
default:
agn2:
if ( --n == 0) {
zperr("Garbage count exceeded");
return(ERROR);
}
if (eflag && ((c &= 0177) & 0140))
bttyout(c);
else if (eflag > 1)
bttyout(c);
#ifdef UNIX
fflush(stderr);
#endif
goto startover;
case ZPAD|0200: /* This is what we want. */
Not8bit = c;
case ZPAD: /* This is what we want. */
break;
}
cancount = 5;
splat:
switch (c = noxrd7()) {
case ZPAD:
goto splat;
case RCDO:
case TIMEOUT:
goto fifi;
default:
goto agn2;
case ZDLE: /* This is what we want. */
break;
}
switch (c = noxrd7()) {
case RCDO:
case TIMEOUT:
goto fifi;
case ZBIN:
Rxframeind = ZBIN; Crc32 = FALSE;
c = zrbhdr(hdr);
break;
case ZBIN32:
Crc32 = Rxframeind = ZBIN32;
c = zrbhdr32(hdr);
break;
case ZHEX:
Rxframeind = ZHEX; Crc32 = FALSE;
c = zrhhdr(hdr);
break;
case CAN:
goto gotcan;
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("Got %s", frametypes[c+FTOFFSET]);
/* **** 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) */
int zrbhdr(char *hdr)
{
register int c, n;
register unsigned short crc;
if ((c = zdlread()) & ~0377)
return c;
Rxtype = c;
crc = updcrc(c, 0);
for (n=4; --n >= 0; ++hdr) {
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(badcrc);
return ERROR;
}
#ifdef ZMODEM
Protocol = ZMODEM;
#endif
Zmodem = 1;
return Rxtype;
}
/* Receive a binary style header (type and position) with 32 bit FCS */
int zrbhdr32(char *hdr)
{
register int c, n;
register UNSL long crc;
if ((c = zdlread()) & ~0377)
return c;
Rxtype = c;
crc = 0xFFFFFFFFL; crc = UPDC32(c, crc);
#ifdef DEBUGZ
vfile("zrbhdr32 c=%X crc=%lX", c, crc);
#endif
for (n=4; --n >= 0; ++hdr) {
if ((c = zdlread()) & ~0377)
return c;
crc = UPDC32(c, crc);
*hdr = c;
#ifdef DEBUGZ
vfile("zrbhdr32 c=%X crc=%lX", c, crc);
#endif
}
for (n=4; --n >= 0;) {
if ((c = zdlread()) & ~0377)
return c;
crc = UPDC32(c, crc);
#ifdef DEBUGZ
vfile("zrbhdr32 c=%X crc=%lX", c, crc);
#endif
}
if (crc != 0xDEBB20E3) {
zperr(badcrc);
return ERROR;
}
#ifdef ZMODEM
Protocol = ZMODEM;
#endif
Zmodem = 1;
return Rxtype;
}
/* Receive a hex style header (type and position) */
int zrhhdr(char *hdr)
{
register int c;
register unsigned short crc;
register int n;
if ((c = zgethex()) < 0)
return c;
Rxtype = c;
crc = updcrc(c, 0);
for (n=4; --n >= 0; ++hdr) {
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(badcrc); return ERROR;
}
switch ( c = readline(1)) {
case 0215:
Not8bit = c;
/* **** FALL THRU TO **** */
case 015:
/* Throw away possible cr/lf */
switch (c = readline(1)) {
case 012:
Not8bit |= c;
}
}
#ifdef ZMODEM
Protocol = ZMODEM;
#endif
Zmodem = 1; return Rxtype;
}
/* Send a byte as two hex digits */
void zputhex(int c)
{
static char digits[] = "0123456789abcdef";
if (Verbose>8)
vfile("zputhex: %02X", 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)
*/
void zsendline(int c)
{
/* Quick check for non control characters */
if (c & 0140)
xsendline(lastsent = c);
else {
switch (c &= 0377) {
case ZDLE:
xsendline(ZDLE);
xsendline (lastsent = (c ^= 0100));
break;
case 015:
case 0215:
if (!Zctlesc && (lastsent & 0177) != '@')
goto sendit;
/* **** FALL THRU TO **** */
case 020:
case 021:
case 023:
case 0220:
case 0221:
case 0223:
xsendline(ZDLE);
c ^= 0100;
sendit:
xsendline(lastsent = c);
break;
default:
if (Zctlesc && ! (c & 0140)) {
xsendline(ZDLE);
c ^= 0100;
}
xsendline(lastsent = c);
}
}
}
/* Decode two lower case hex digits into an 8 bit byte value */
int zgethex()
{
register int c;
c = zgeth1();
if (Verbose>8)
vfile("zgethex: %02X", c);
return c;
}
int zgeth1()
{
register int c, n;
if ((c = noxrd7()) < 0)
return c;
n = c - '0';
if (n > 9)
n -= ('a' - ':');
if (n & ~0xF)
return ERROR;
if ((c = noxrd7()) < 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
*/
int zdlread()
{
register int c;
again:
/* Quick check for non control characters */
if ((c = readline(Rxtimeout)) & 0140)
return c;
switch (c) {
case ZDLE:
break;
case 023:
case 0223:
case 021:
case 0221:
goto again;
default:
if (Zctlesc && !(c & 0140)) {
goto again;
}
return c;
}
again2:
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;
case 023:
case 0223:
case 021:
case 0221:
goto again2;
default:
if (Zctlesc && ! (c & 0140)) {
goto again2;
}
if ((c & 0140) == 0100)
return (c ^ 0100);
break;
}
if (Verbose>1)
zperr("Bad escape sequence %x", c);
return ERROR;
}
/*
* Read a character from the modem line with timeout.
* Eat parity, XON and XOFF characters.
*/
int noxrd7()
{
register int c;
for (;;) {
if ((c = readline(Rxtimeout)) < 0)
return c;
switch (c &= 0177) {
case XON:
case XOFF:
continue;
default:
if (Zctlesc && !(c & 0140))
continue;
case '\r':
case '\n':
case ZDLE:
return c;
}
}
}
/* Store long integer pos in Txhdr */
void stohdr(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(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;
}
/* End of zm.c */