/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <ctype.h> enum {	Soh=	0x1,	Stx=	0x2,	Eot=	0x4,	Ack=	0x6,	Nak=	0x15,	Cancel=	0x18,}; int send(uchar*, int);int notifyf(void*, char*); int debug, progress, onek; voiderrorout(int ctl, int bytes){	uchar buf[2]; 	buf[0] = Cancel;	write(1, buf, 1);	fprint(2, "\nxms: gave up after %d bytes\n", bytes);	write(ctl, "rawoff", 6);	exits("cancel");} ushortupdcrc(int c, ushort crc){	int count; 	for (count=8; --count>=0;) {		if (crc & 0x8000) {			crc <<= 1;			crc += (((c<<=1) & 0400)  !=  0);			crc ^= 0x1021;		}		else {			crc <<= 1;			crc += (((c<<=1) & 0400)  !=  0);		}	}	return crc;	} voidmain(int argc, char **argv){	uchar c;	uchar buf[1024+5];	uchar seqno;	int fd, ctl;	long n;	int sum;	uchar *p;	int bytes;	int crcmode; 	ARGBEGIN{	case 'd':		debug = 1;		break;	case 'p':		progress = 1;		break;	case '1':		onek = 1;		break;	}ARGEND 	if(argc != 1){		fprint(2, "usage: xms filename\n");		exits("usage");	}	fd = open(argv[0], OREAD);	if(fd < 0){		perror("xms");		exits("open");	} 	ctl = open("/dev/consctl", OWRITE);	if(ctl < 0){		perror("xms");		exits("consctl");	}	write(ctl, "rawon", 5); 	/* give the other side a 30 seconds to signal ready */	atnotify(notifyf, 1);	alarm(30*1000);	crcmode = 0;	for(;;){		if(read(0, &c, 1) != 1){			fprint(2, "xms: timeout\n");			exits("timeout");		}		c = c & 0x7f;		if(c == Nak)			break;		if(c == 'C') {			if (debug)				fprint(2, "crc mode engaged\n");			crcmode = 1;			break;		}	}	alarm(0); 	/* send the file in 128/1024 byte chunks */	for(bytes = 0, seqno = 1; ; bytes += n, seqno++){		n = read(fd, buf+3, onek ? 1024 : 128);		if(n < 0)			exits("read");		if(n == 0)			break;		if(n < (onek ? 1024 : 128))			memset(&buf[n+3], 0, (onek ? 1024 : 128)-n);		buf[0] = onek ? Stx : Soh;		buf[1] = seqno;		buf[2] = 255 - seqno; 		/* calculate checksum and stuff into last byte */		if (crcmode) {			unsigned short crc;			crc = 0;			for(p = buf + 3; p < &buf[(onek ? 1024 : 128)+3]; p++)				crc = updcrc(*p, crc);			crc = updcrc(0, crc);			crc = updcrc(0, crc);			buf[(onek ? 1024 : 128) + 3] = crc >> 8;			buf[(onek ? 1024 : 128) + 4] = crc;		}		else {			sum = 0;			for(p = buf + 3; p < &buf[(onek ? 1024 : 128)+3]; p++)				sum += *p;			buf[(onek ? 1024 : 128) + 3] = sum;		} 		if(send(buf, (onek ? 1024 : 128) + 4 + crcmode) < 0)			errorout(ctl, bytes);		if (progress && bytes % 10240 == 0)			fprint(2, "%dK\n", bytes / 1024);	} 	/* tell other side we're done */	buf[0] = Eot;	if(send(buf, 1) < 0)		errorout(ctl, bytes); 	fprint(2, "xms: %d bytes transmitted\n", bytes);	write(ctl, "rawoff", 6);	exits(0);} /* *  send a message till it's acked or we give up */intsend(uchar *buf, int len){	int tries;	int n;	uchar c; 	for(tries = 0;; tries++, sleep(2*1000)){		if(tries == 10)			return -1;		if(write(1, buf, len) != len)			return -1;				alarm(30*1000);		n = read(0, &c, 1);		alarm(0);		if(debug) switch(c){		case Soh:			fprint(2, " Soh");			break;		case Eot:			fprint(2, " Eot");			break;		case Ack:			fprint(2, " Ack");			break;		case Nak:			fprint(2, " Nak");			break;		case Cancel:			fprint(2, "\nremote Cancel\n");			return -1;		default:			if(isprint(c))				fprint(2, "%c", c);			else				fprint(2, " \\0%o", c);		}		c = c & 0x7f;		if(n == 1 && c == Ack)			break;	}	return 0;} intnotifyf(void *a, char *msg){	USED(a);	if(strcmp(msg, "alarm") == 0)		return 1;	return 0;}