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tip.c revision 1.28 
      1 /*	$NetBSD: tip.c,v 1.28 2004/11/04 07:29:09 dsl Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\n\
     35 	The Regents of the University of California.  All rights reserved.\n");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)tip.c	8.1 (Berkeley) 6/6/93";
     41 #endif
     42 __RCSID("$NetBSD: tip.c,v 1.28 2004/11/04 07:29:09 dsl Exp $");
     43 #endif /* not lint */
     44 
     45 /*
     46  * tip - UNIX link to other systems
     47  *  tip [-v] [-speed] system-name
     48  * or
     49  *  cu phone-number [-s speed] [-l line] [-a acu]
     50  */
     51 #include "tip.h"
     52 #include "pathnames.h"
     53 
     54 /*
     55  * Baud rate mapping table
     56  */
     57 int rates[] = {
     58 	0, 50, 75, 110, 134, 150, 200, 300, 600,
     59 	1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, -1
     60 };
     61 
     62 int	escape __P((void));
     63 int	main __P((int, char **));
     64 void	intprompt __P((int));
     65 void	tipin __P((void));
     66 
     67 char	PNbuf[256];			/* This limits the size of a number */
     68 
     69 static char path_phones[] = _PATH_PHONES;
     70 
     71 int
     72 main(argc, argv)
     73 	int argc;
     74 	char *argv[];
     75 {
     76 	char *System = NULL;
     77 	int i;
     78 	char *p;
     79 	const char *q;
     80 	char sbuf[12];
     81 	int fcarg;
     82 
     83 	gid = getgid();
     84 	egid = getegid();
     85 	uid = getuid();
     86 	euid = geteuid();
     87 	if (equal(basename(argv[0]), "cu")) {
     88 		cumode = 1;
     89 		cumain(argc, argv);
     90 		goto cucommon;
     91 	}
     92 
     93 	if (argc > 4) {
     94 		fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
     95 		exit(1);
     96 	}
     97 	if (!isatty(0)) {
     98 		fprintf(stderr, "tip: must be interactive\n");
     99 		exit(1);
    100 	}
    101 
    102 	for (; argc > 1; argv++, argc--) {
    103 		if (argv[1][0] != '-')
    104 			System = argv[1];
    105 		else switch (argv[1][1]) {
    106 
    107 		case 'v':
    108 			vflag++;
    109 			break;
    110 
    111 		case '0': case '1': case '2': case '3': case '4':
    112 		case '5': case '6': case '7': case '8': case '9':
    113 			BR = atoi(&argv[1][1]);
    114 			break;
    115 
    116 		default:
    117 			fprintf(stderr, "tip: %s, unknown option\n", argv[1]);
    118 			break;
    119 		}
    120 	}
    121 
    122 	if (System == NULL)
    123 		goto notnumber;
    124 	if (isalpha((unsigned char)*System))
    125 		goto notnumber;
    126 	/*
    127 	 * System name is really a phone number...
    128 	 * Copy the number then stomp on the original (in case the number
    129 	 *	is private, we don't want 'ps' or 'w' to find it).
    130 	 */
    131 	if (strlen(System) > sizeof PNbuf - 1) {
    132 		fprintf(stderr, "tip: phone number too long (max = %d bytes)\n",
    133 			(int)sizeof(PNbuf) - 1);
    134 		exit(1);
    135 	}
    136 	(void)strlcpy(PNbuf, System, sizeof(PNbuf));
    137 	for (p = System; *p; p++)
    138 		*p = '\0';
    139 	PN = PNbuf;
    140 	(void)snprintf(sbuf, sizeof sbuf, "tip%d", (int)BR);
    141 	System = sbuf;
    142 
    143 notnumber:
    144 	(void)signal(SIGINT, cleanup);
    145 	(void)signal(SIGQUIT, cleanup);
    146 	(void)signal(SIGHUP, cleanup);
    147 	(void)signal(SIGTERM, cleanup);
    148 
    149 	if ((i = hunt(System)) == 0) {
    150 		printf("all ports busy\n");
    151 		exit(3);
    152 	}
    153 	if (i == -1) {
    154 		printf("link down\n");
    155 		(void)uu_unlock(uucplock);
    156 		exit(3);
    157 	}
    158 	setbuf(stdout, NULL);
    159 	loginit();
    160 
    161 	/*
    162 	 * Now that we have the logfile and the ACU open
    163 	 *  return to the real uid and gid.  These things will
    164 	 *  be closed on exit.  Swap real and effective uid's
    165 	 *  so we can get the original permissions back
    166 	 *  for removing the uucp lock.
    167 	 */
    168 	user_uid();
    169 
    170 	/*
    171 	 * Kludge, their's no easy way to get the initialization
    172 	 *   in the right order, so force it here
    173 	 */
    174 	if ((PH = getenv("PHONES")) == NULL)
    175 		PH = path_phones;
    176 	vinit();				/* init variables */
    177 	setparity("even");			/* set the parity table */
    178 	if ((i = speed(number(value(BAUDRATE)))) == 0) {
    179 		printf("tip: bad baud rate %d\n", (int)number(value(BAUDRATE)));
    180 		daemon_uid();
    181 		(void)uu_unlock(uucplock);
    182 		exit(3);
    183 	}
    184 
    185 	/*
    186 	 * Hardwired connections require the
    187 	 *  line speed set before they make any transmissions
    188 	 *  (this is particularly true of things like a DF03-AC)
    189 	 */
    190 	if (HW)
    191 		ttysetup(i);
    192 	if ((q = connect()) != NULL) {
    193 		printf("\07%s\n[EOT]\n", q);
    194 		daemon_uid();
    195 		(void)uu_unlock(uucplock);
    196 		exit(1);
    197 	}
    198 	if (!HW)
    199 		ttysetup(i);
    200 
    201 	/*
    202 	 * Direct connections with no carrier require using O_NONBLOCK on
    203 	 * open, but we don't want to keep O_NONBLOCK after open because it
    204 	 * will cause busy waits.
    205 	 */
    206 	if (DC &&
    207 	    ((fcarg = fcntl(FD, F_GETFL, 0)) < 0 ||
    208 	     fcntl(FD, F_SETFL, fcarg & ~O_NONBLOCK) < 0)) {
    209 		printf("tip: can't clear O_NONBLOCK: %s", strerror (errno));
    210 		daemon_uid();
    211 		(void)uu_unlock(uucplock);
    212 		exit(1);
    213 	}
    214 
    215 cucommon:
    216 	/*
    217 	 * From here down the code is shared with
    218 	 * the "cu" version of tip.
    219 	 */
    220 
    221 	tcgetattr(0, &defterm);
    222 	term = defterm;
    223 	term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
    224 	term.c_iflag &= ~(INPCK|ICRNL);
    225 	term.c_oflag &= ~OPOST;
    226 	term.c_cc[VMIN] = 1;
    227 	term.c_cc[VTIME] = 0;
    228 	defchars = term;
    229 	term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
    230 		term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
    231 	 	term.c_cc[VLNEXT] = _POSIX_VDISABLE;
    232 	raw();
    233 
    234 	pipe(fildes); pipe(repdes);
    235 	(void)signal(SIGALRM, alrmtimeout);
    236 
    237 	/*
    238 	 * Everything's set up now:
    239 	 *	connection established (hardwired or dialup)
    240 	 *	line conditioned (baud rate, mode, etc.)
    241 	 *	internal data structures (variables)
    242 	 * so, fork one process for local side and one for remote.
    243 	 */
    244 	printf("%s", cumode ? "Connected\r\n" : "\07connected\r\n");
    245 	switch (pid = fork()) {
    246 	default:
    247 		tipin();
    248 		break;
    249 	case 0:
    250 		tipout();
    251 		break;
    252 	case -1:
    253 		err(1, "can't fork");
    254 	}
    255 	/*NOTREACHED*/
    256 	exit(0);	/* XXX: pacify gcc */
    257 }
    258 
    259 void
    260 cleanup(dummy)
    261 	int dummy;
    262 {
    263 
    264 	daemon_uid();
    265 	(void)uu_unlock(uucplock);
    266 	if (odisc)
    267 		ioctl(0, TIOCSETD, (char *)&odisc);
    268 	exit(0);
    269 }
    270 
    271 /*
    272  * Muck with user ID's.  We are setuid to the owner of the lock
    273  * directory when we start.  user_uid() reverses real and effective
    274  * ID's after startup, to run with the user's permissions.
    275  * daemon_uid() switches back to the privileged uid for unlocking.
    276  * Finally, to avoid running a shell with the wrong real uid,
    277  * shell_uid() sets real and effective uid's to the user's real ID.
    278  */
    279 static int uidswapped;
    280 
    281 void
    282 user_uid()
    283 {
    284 
    285 	if (uidswapped == 0) {
    286 		seteuid(uid);
    287 		uidswapped = 1;
    288 	}
    289 }
    290 
    291 void
    292 daemon_uid()
    293 {
    294 
    295 	if (uidswapped) {
    296 		seteuid(euid);
    297 		uidswapped = 0;
    298 	}
    299 }
    300 
    301 void
    302 shell_uid()
    303 {
    304 
    305 	seteuid(uid);
    306 }
    307 
    308 /*
    309  * put the controlling keyboard into raw mode
    310  */
    311 void
    312 raw()
    313 {
    314 
    315 	tcsetattr(0, TCSADRAIN, &term);
    316 }
    317 
    318 
    319 /*
    320  * return keyboard to normal mode
    321  */
    322 void
    323 unraw()
    324 {
    325 
    326 	tcsetattr(0, TCSADRAIN, &defterm);
    327 }
    328 
    329 static	jmp_buf promptbuf;
    330 
    331 /*
    332  * Print string ``s'', then read a string
    333  *  in from the terminal.  Handles signals & allows use of
    334  *  normal erase and kill characters.
    335  */
    336 int
    337 prompt(s, p, l)
    338 	const char *s;
    339 	char *p;
    340 	size_t l;
    341 {
    342 	int c;
    343 	char *b = p;
    344 	sig_t oint, oquit;
    345 
    346 #if __GNUC__		/* XXX: pacify gcc */
    347 	(void)&p;
    348 #endif
    349 
    350 	stoprompt = 0;
    351 	oint = signal(SIGINT, intprompt);
    352 	oquit = signal(SIGQUIT, SIG_IGN);
    353 	unraw();
    354 	printf("%s", s);
    355 	if (setjmp(promptbuf) == 0)
    356 		while ((c = getchar()) != -1 && (*p = c) != '\n' &&
    357 		    b + l > p)
    358 			p++;
    359 	*p = '\0';
    360 
    361 	raw();
    362 	(void)signal(SIGINT, oint);
    363 	(void)signal(SIGQUIT, oquit);
    364 	return (stoprompt || p == b);
    365 }
    366 
    367 /*
    368  * Interrupt service routine during prompting
    369  */
    370 void
    371 intprompt(dummy)
    372 	int dummy;
    373 {
    374 
    375 	(void)signal(SIGINT, SIG_IGN);
    376 	stoprompt = 1;
    377 	printf("\r\n");
    378 	longjmp(promptbuf, 1);
    379 }
    380 
    381 /*
    382  * ****TIPIN   TIPIN****
    383  */
    384 void
    385 tipin()
    386 {
    387 	char gch, bol = 1;
    388 
    389 	/*
    390 	 * Kinda klugey here...
    391 	 *   check for scripting being turned on from the .tiprc file,
    392 	 *   but be careful about just using setscript(), as we may
    393 	 *   send a SIGEMT before tipout has a chance to set up catching
    394 	 *   it; so wait a second, then setscript()
    395 	 */
    396 	if (boolean(value(SCRIPT))) {
    397 		sleep(1);
    398 		setscript();
    399 	}
    400 
    401 	while (1) {
    402 		gch = getchar()&STRIP_PAR;
    403 		if ((gch == character(value(ESCAPE))) && bol) {
    404 			if (!(gch = escape()))
    405 				continue;
    406 		} else if (!cumode &&
    407 		    gch && gch == character(value(RAISECHAR))) {
    408 			setboolean(value(RAISE), !boolean(value(RAISE)));
    409 			continue;
    410 		} else if (gch == '\r') {
    411 			bol = 1;
    412 			xpwrite(FD, &gch, 1);
    413 			if (boolean(value(HALFDUPLEX)))
    414 				printf("\r\n");
    415 			continue;
    416 		} else if (!cumode && gch && gch == character(value(FORCE)))
    417 			gch = getchar()&STRIP_PAR;
    418 		bol = any(gch, value(EOL));
    419 		if (boolean(value(RAISE)) && islower((unsigned char)gch))
    420 			gch = toupper((unsigned char)gch);
    421 		xpwrite(FD, &gch, 1);
    422 		if (boolean(value(HALFDUPLEX)))
    423 			printf("%c", gch);
    424 	}
    425 }
    426 
    427 /*
    428  * Escape handler --
    429  *  called on recognition of ``escapec'' at the beginning of a line
    430  */
    431 int
    432 escape()
    433 {
    434 	char gch;
    435 	esctable_t *p;
    436 	char c = character(value(ESCAPE));
    437 
    438 	gch = (getchar()&STRIP_PAR);
    439 	for (p = etable; p->e_char; p++)
    440 		if (p->e_char == gch) {
    441 			if ((p->e_flags&PRIV) && uid)
    442 				continue;
    443 			printf("%s", ctrl(c));
    444 			(*p->e_func)(gch);
    445 			return (0);
    446 		}
    447 	/* ESCAPE ESCAPE forces ESCAPE */
    448 	if (c != gch)
    449 		xpwrite(FD, &c, 1);
    450 	return (gch);
    451 }
    452 
    453 int
    454 speed(n)
    455 	int n;
    456 {
    457 	int *p;
    458 
    459 	for (p = rates; *p != -1;  p++)
    460 		if (*p == n)
    461 			return n;
    462 	return 0;
    463 }
    464 
    465 int
    466 any(c, p)
    467 	char c;
    468 	const char *p;
    469 {
    470 
    471 	while (p && *p)
    472 		if (*p++ == c)
    473 			return (1);
    474 	return (0);
    475 }
    476 
    477 char *
    478 interp(s)
    479 	const char *s;
    480 {
    481 	static char buf[256];
    482 	char *p = buf, c;
    483 	const char *q;
    484 
    485 	while ((c = *s++) != 0 && buf + sizeof buf - p > 2) {
    486 		for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
    487 			if (*q++ == c) {
    488 				*p++ = '\\'; *p++ = *q;
    489 				goto next;
    490 			}
    491 		if (c < 040) {
    492 			*p++ = '^'; *p++ = c + 'A'-1;
    493 		} else if (c == 0177) {
    494 			*p++ = '^'; *p++ = '?';
    495 		} else
    496 			*p++ = c;
    497 	next:
    498 		;
    499 	}
    500 	*p = '\0';
    501 	return (buf);
    502 }
    503 
    504 char *
    505 ctrl(c)
    506 	char c;
    507 {
    508 	static char s[3];
    509 
    510 	if (c < 040 || c == 0177) {
    511 		s[0] = '^';
    512 		s[1] = c == 0177 ? '?' : c+'A'-1;
    513 		s[2] = '\0';
    514 	} else {
    515 		s[0] = c;
    516 		s[1] = '\0';
    517 	}
    518 	return (s);
    519 }
    520 
    521 /*
    522  * Help command
    523  */
    524 void
    525 help(c)
    526 	char c;
    527 {
    528 	esctable_t *p;
    529 
    530 	printf("%c\r\n", c);
    531 	for (p = etable; p->e_char; p++) {
    532 		if ((p->e_flags&PRIV) && uid)
    533 			continue;
    534 		printf("%2s", ctrl(character(value(ESCAPE))));
    535 		printf("%-2s %c   %s\r\n", ctrl(p->e_char),
    536 			p->e_flags&EXP ? '*': ' ', p->e_help);
    537 	}
    538 }
    539 
    540 /*
    541  * Set up the "remote" tty's state
    542  */
    543 void
    544 ttysetup(spd)
    545 	int spd;
    546 {
    547 	struct termios	cntrl;
    548 
    549 	tcgetattr(FD, &cntrl);
    550 	cfsetospeed(&cntrl, spd);
    551 	cfsetispeed(&cntrl, spd);
    552 	cntrl.c_cflag &= ~(CSIZE|PARENB);
    553 	cntrl.c_cflag |= CS8;
    554 	if (DC)
    555 		cntrl.c_cflag |= CLOCAL;
    556 	cntrl.c_iflag &= ~(ISTRIP|ICRNL);
    557 	cntrl.c_oflag &= ~OPOST;
    558 	cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
    559 	cntrl.c_cc[VMIN] = 1;
    560 	cntrl.c_cc[VTIME] = 0;
    561 	if (boolean(value(TAND)))
    562 		cntrl.c_iflag |= IXOFF;
    563 	tcsetattr(FD, TCSAFLUSH, &cntrl);
    564 }
    565 
    566 static char partab[0200];
    567 
    568 /*
    569  * Do a write to the remote machine with the correct parity.
    570  * We are doing 8 bit wide output, so we just generate a character
    571  * with the right parity and output it.
    572  */
    573 void
    574 xpwrite(fd, buf, n)
    575 	int fd;
    576 	char *buf;
    577 	int n;
    578 {
    579 	int i;
    580 	char *bp;
    581 
    582 	bp = buf;
    583 	if (bits8 == 0)
    584 		for (i = 0; i < n; i++) {
    585 			*bp = partab[(*bp) & 0177];
    586 			bp++;
    587 		}
    588 	if (write(fd, buf, n) < 0) {
    589 		if (errno == EIO)
    590 			tipabort("Lost carrier.");
    591 		/* this is questionable */
    592 		perror("write");
    593 	}
    594 }
    595 
    596 /*
    597  * Build a parity table with appropriate high-order bit.
    598  */
    599 void
    600 setparity(defparity)
    601 	const char *defparity;
    602 {
    603 	int i, flip, clr, set;
    604 	const char *parity;
    605 	static char *curpar;
    606 
    607 	if (value(PARITY) == NULL || (value(PARITY))[0] == '\0') {
    608 		if (curpar != NULL)
    609 			free(curpar);
    610 		value(PARITY) = curpar = strdup(defparity);
    611 	}
    612 	parity = value(PARITY);
    613 	if (equal(parity, "none")) {
    614 		bits8 = 1;
    615 		return;
    616 	}
    617 	bits8 = 0;
    618 	flip = 0;
    619 	clr = 0377;
    620 	set = 0;
    621 	if (equal(parity, "odd"))
    622 		flip = 0200;			/* reverse bit 7 */
    623 	else if (equal(parity, "zero"))
    624 		clr = 0177;			/* turn off bit 7 */
    625 	else if (equal(parity, "one"))
    626 		set = 0200;			/* turn on bit 7 */
    627 	else if (!equal(parity, "even")) {
    628 		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
    629 		(void) fflush(stderr);
    630 	}
    631 	for (i = 0; i < 0200; i++)
    632 		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
    633 }
    634