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tip.c revision 1.24 
      1 /*	$NetBSD: tip.c,v 1.24 2003/08/07 11:16:19 agc 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 1.24 2003/08/07 11:16:19 agc 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 int
     70 main(argc, argv)
     71 	int argc;
     72 	char *argv[];
     73 {
     74 	char *system = NULL;
     75 	int i;
     76 	char *p;
     77 	char sbuf[12];
     78 	int fcarg;
     79 
     80 	gid = getgid();
     81 	egid = getegid();
     82 	uid = getuid();
     83 	euid = geteuid();
     84 	if (equal(basename(argv[0]), "cu")) {
     85 		cumode = 1;
     86 		cumain(argc, argv);
     87 		goto cucommon;
     88 	}
     89 
     90 	if (argc > 4) {
     91 		fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
     92 		exit(1);
     93 	}
     94 	if (!isatty(0)) {
     95 		fprintf(stderr, "tip: must be interactive\n");
     96 		exit(1);
     97 	}
     98 
     99 	for (; argc > 1; argv++, argc--) {
    100 		if (argv[1][0] != '-')
    101 			system = argv[1];
    102 		else switch (argv[1][1]) {
    103 
    104 		case 'v':
    105 			vflag++;
    106 			break;
    107 
    108 		case '0': case '1': case '2': case '3': case '4':
    109 		case '5': case '6': case '7': case '8': case '9':
    110 			BR = atoi(&argv[1][1]);
    111 			break;
    112 
    113 		default:
    114 			fprintf(stderr, "tip: %s, unknown option\n", argv[1]);
    115 			break;
    116 		}
    117 	}
    118 
    119 	if (system == NULL)
    120 		goto notnumber;
    121 	if (isalpha((unsigned char)*system))
    122 		goto notnumber;
    123 	/*
    124 	 * System name is really a phone number...
    125 	 * Copy the number then stomp on the original (in case the number
    126 	 *	is private, we don't want 'ps' or 'w' to find it).
    127 	 */
    128 	if (strlen(system) > sizeof PNbuf - 1) {
    129 		fprintf(stderr, "tip: phone number too long (max = %d bytes)\n",
    130 			(int)sizeof(PNbuf) - 1);
    131 		exit(1);
    132 	}
    133 	strncpy(PNbuf, system, sizeof PNbuf - 1);
    134 	PNbuf[sizeof PNbuf - 1] = '\0';
    135 	for (p = system; *p; p++)
    136 		*p = '\0';
    137 	PN = PNbuf;
    138 	(void)snprintf(sbuf, sizeof sbuf, "tip%d", (int)BR);
    139 	system = sbuf;
    140 
    141 notnumber:
    142 	(void)signal(SIGINT, cleanup);
    143 	(void)signal(SIGQUIT, cleanup);
    144 	(void)signal(SIGHUP, cleanup);
    145 	(void)signal(SIGTERM, cleanup);
    146 
    147 	if ((i = hunt(system)) == 0) {
    148 		printf("all ports busy\n");
    149 		exit(3);
    150 	}
    151 	if (i == -1) {
    152 		printf("link down\n");
    153 		(void)uu_unlock(uucplock);
    154 		exit(3);
    155 	}
    156 	setbuf(stdout, NULL);
    157 	loginit();
    158 
    159 	/*
    160 	 * Now that we have the logfile and the ACU open
    161 	 *  return to the real uid and gid.  These things will
    162 	 *  be closed on exit.  Swap real and effective uid's
    163 	 *  so we can get the original permissions back
    164 	 *  for removing the uucp lock.
    165 	 */
    166 	user_uid();
    167 
    168 	/*
    169 	 * Kludge, their's no easy way to get the initialization
    170 	 *   in the right order, so force it here
    171 	 */
    172 	if ((PH = getenv("PHONES")) == NULL)
    173 		PH = _PATH_PHONES;
    174 	vinit();				/* init variables */
    175 	setparity("even");			/* set the parity table */
    176 	if ((i = speed(number(value(BAUDRATE)))) == 0) {
    177 		printf("tip: bad baud rate %d\n", (int)number(value(BAUDRATE)));
    178 		daemon_uid();
    179 		(void)uu_unlock(uucplock);
    180 		exit(3);
    181 	}
    182 
    183 	/*
    184 	 * Hardwired connections require the
    185 	 *  line speed set before they make any transmissions
    186 	 *  (this is particularly true of things like a DF03-AC)
    187 	 */
    188 	if (HW)
    189 		ttysetup(i);
    190 	if ((p = connect()) != NULL) {
    191 		printf("\07%s\n[EOT]\n", p);
    192 		daemon_uid();
    193 		(void)uu_unlock(uucplock);
    194 		exit(1);
    195 	}
    196 	if (!HW)
    197 		ttysetup(i);
    198 
    199 	/*
    200 	 * Direct connections with no carrier require using O_NONBLOCK on
    201 	 * open, but we don't want to keep O_NONBLOCK after open because it
    202 	 * will cause busy waits.
    203 	 */
    204 	if (DC &&
    205 	    ((fcarg = fcntl(FD, F_GETFL, 0)) < 0 ||
    206 	     fcntl(FD, F_SETFL, fcarg & ~O_NONBLOCK) < 0)) {
    207 		printf("tip: can't clear O_NONBLOCK: %s", strerror (errno));
    208 		daemon_uid();
    209 		(void)uu_unlock(uucplock);
    210 		exit(1);
    211 	}
    212 
    213 cucommon:
    214 	/*
    215 	 * From here down the code is shared with
    216 	 * the "cu" version of tip.
    217 	 */
    218 
    219 	tcgetattr(0, &defterm);
    220 	term = defterm;
    221 	term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
    222 	term.c_iflag &= ~(INPCK|ICRNL);
    223 	term.c_oflag &= ~OPOST;
    224 	term.c_cc[VMIN] = 1;
    225 	term.c_cc[VTIME] = 0;
    226 	defchars = term;
    227 	term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
    228 		term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
    229 	 	term.c_cc[VLNEXT] = _POSIX_VDISABLE;
    230 	raw();
    231 
    232 	pipe(fildes); pipe(repdes);
    233 	(void)signal(SIGALRM, alrmtimeout);
    234 
    235 	/*
    236 	 * Everything's set up now:
    237 	 *	connection established (hardwired or dialup)
    238 	 *	line conditioned (baud rate, mode, etc.)
    239 	 *	internal data structures (variables)
    240 	 * so, fork one process for local side and one for remote.
    241 	 */
    242 	printf("%s", cumode ? "Connected\r\n" : "\07connected\r\n");
    243 	switch (pid = fork()) {
    244 	default:
    245 		tipin();
    246 		break;
    247 	case 0:
    248 		tipout();
    249 		break;
    250 	case -1:
    251 		err(1, "can't fork");
    252 	}
    253 	/*NOTREACHED*/
    254 	exit(0);	/* XXX: pacify gcc */
    255 }
    256 
    257 void
    258 cleanup(dummy)
    259 	int dummy;
    260 {
    261 
    262 	daemon_uid();
    263 	(void)uu_unlock(uucplock);
    264 	if (odisc)
    265 		ioctl(0, TIOCSETD, (char *)&odisc);
    266 	exit(0);
    267 }
    268 
    269 /*
    270  * Muck with user ID's.  We are setuid to the owner of the lock
    271  * directory when we start.  user_uid() reverses real and effective
    272  * ID's after startup, to run with the user's permissions.
    273  * daemon_uid() switches back to the privileged uid for unlocking.
    274  * Finally, to avoid running a shell with the wrong real uid,
    275  * shell_uid() sets real and effective uid's to the user's real ID.
    276  */
    277 static int uidswapped;
    278 
    279 void
    280 user_uid()
    281 {
    282 
    283 	if (uidswapped == 0) {
    284 		seteuid(uid);
    285 		uidswapped = 1;
    286 	}
    287 }
    288 
    289 void
    290 daemon_uid()
    291 {
    292 
    293 	if (uidswapped) {
    294 		seteuid(euid);
    295 		uidswapped = 0;
    296 	}
    297 }
    298 
    299 void
    300 shell_uid()
    301 {
    302 
    303 	seteuid(uid);
    304 }
    305 
    306 /*
    307  * put the controlling keyboard into raw mode
    308  */
    309 void
    310 raw()
    311 {
    312 
    313 	tcsetattr(0, TCSADRAIN, &term);
    314 }
    315 
    316 
    317 /*
    318  * return keyboard to normal mode
    319  */
    320 void
    321 unraw()
    322 {
    323 
    324 	tcsetattr(0, TCSADRAIN, &defterm);
    325 }
    326 
    327 static	jmp_buf promptbuf;
    328 
    329 /*
    330  * Print string ``s'', then read a string
    331  *  in from the terminal.  Handles signals & allows use of
    332  *  normal erase and kill characters.
    333  */
    334 int
    335 prompt(s, p, l)
    336 	char *s;
    337 	char *p;
    338 	size_t l;
    339 {
    340 	int c;
    341 	char *b = p;
    342 	sig_t oint, oquit;
    343 
    344 #if __GNUC__		/* XXX: pacify gcc */
    345 	(void)&p;
    346 #endif
    347 
    348 	stoprompt = 0;
    349 	oint = signal(SIGINT, intprompt);
    350 	oquit = signal(SIGQUIT, SIG_IGN);
    351 	unraw();
    352 	printf("%s", s);
    353 	if (setjmp(promptbuf) == 0)
    354 		while ((c = getchar()) != -1 && (*p = c) != '\n' &&
    355 		    b + l > p)
    356 			p++;
    357 	*p = '\0';
    358 
    359 	raw();
    360 	(void)signal(SIGINT, oint);
    361 	(void)signal(SIGQUIT, oquit);
    362 	return (stoprompt || p == b);
    363 }
    364 
    365 /*
    366  * Interrupt service routine during prompting
    367  */
    368 void
    369 intprompt(dummy)
    370 	int dummy;
    371 {
    372 
    373 	(void)signal(SIGINT, SIG_IGN);
    374 	stoprompt = 1;
    375 	printf("\r\n");
    376 	longjmp(promptbuf, 1);
    377 }
    378 
    379 /*
    380  * ****TIPIN   TIPIN****
    381  */
    382 void
    383 tipin()
    384 {
    385 	char gch, bol = 1;
    386 
    387 	/*
    388 	 * Kinda klugey here...
    389 	 *   check for scripting being turned on from the .tiprc file,
    390 	 *   but be careful about just using setscript(), as we may
    391 	 *   send a SIGEMT before tipout has a chance to set up catching
    392 	 *   it; so wait a second, then setscript()
    393 	 */
    394 	if (boolean(value(SCRIPT))) {
    395 		sleep(1);
    396 		setscript();
    397 	}
    398 
    399 	while (1) {
    400 		gch = getchar()&STRIP_PAR;
    401 		if ((gch == character(value(ESCAPE))) && bol) {
    402 			if (!(gch = escape()))
    403 				continue;
    404 		} else if (!cumode &&
    405 		    gch && gch == character(value(RAISECHAR))) {
    406 			setboolean(value(RAISE), !boolean(value(RAISE)));
    407 			continue;
    408 		} else if (gch == '\r') {
    409 			bol = 1;
    410 			xpwrite(FD, &gch, 1);
    411 			if (boolean(value(HALFDUPLEX)))
    412 				printf("\r\n");
    413 			continue;
    414 		} else if (!cumode && gch && gch == character(value(FORCE)))
    415 			gch = getchar()&STRIP_PAR;
    416 		bol = any(gch, value(EOL));
    417 		if (boolean(value(RAISE)) && islower((unsigned char)gch))
    418 			gch = toupper(gch);
    419 		xpwrite(FD, &gch, 1);
    420 		if (boolean(value(HALFDUPLEX)))
    421 			printf("%c", gch);
    422 	}
    423 }
    424 
    425 /*
    426  * Escape handler --
    427  *  called on recognition of ``escapec'' at the beginning of a line
    428  */
    429 int
    430 escape()
    431 {
    432 	char gch;
    433 	esctable_t *p;
    434 	char c = character(value(ESCAPE));
    435 
    436 	gch = (getchar()&STRIP_PAR);
    437 	for (p = etable; p->e_char; p++)
    438 		if (p->e_char == gch) {
    439 			if ((p->e_flags&PRIV) && uid)
    440 				continue;
    441 			printf("%s", ctrl(c));
    442 			(*p->e_func)(gch);
    443 			return (0);
    444 		}
    445 	/* ESCAPE ESCAPE forces ESCAPE */
    446 	if (c != gch)
    447 		xpwrite(FD, &c, 1);
    448 	return (gch);
    449 }
    450 
    451 int
    452 speed(n)
    453 	int n;
    454 {
    455 	int *p;
    456 
    457 	for (p = rates; *p != -1;  p++)
    458 		if (*p == n)
    459 			return n;
    460 	return 0;
    461 }
    462 
    463 int
    464 any(c, p)
    465 	char c, *p;
    466 {
    467 
    468 	while (p && *p)
    469 		if (*p++ == c)
    470 			return (1);
    471 	return (0);
    472 }
    473 
    474 char *
    475 interp(s)
    476 	char *s;
    477 {
    478 	static char buf[256];
    479 	char *p = buf, c, *q;
    480 
    481 	while ((c = *s++) != 0 && buf + sizeof buf - p > 2) {
    482 		for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
    483 			if (*q++ == c) {
    484 				*p++ = '\\'; *p++ = *q;
    485 				goto next;
    486 			}
    487 		if (c < 040) {
    488 			*p++ = '^'; *p++ = c + 'A'-1;
    489 		} else if (c == 0177) {
    490 			*p++ = '^'; *p++ = '?';
    491 		} else
    492 			*p++ = c;
    493 	next:
    494 		;
    495 	}
    496 	*p = '\0';
    497 	return (buf);
    498 }
    499 
    500 char *
    501 ctrl(c)
    502 	char c;
    503 {
    504 	static char s[3];
    505 
    506 	if (c < 040 || c == 0177) {
    507 		s[0] = '^';
    508 		s[1] = c == 0177 ? '?' : c+'A'-1;
    509 		s[2] = '\0';
    510 	} else {
    511 		s[0] = c;
    512 		s[1] = '\0';
    513 	}
    514 	return (s);
    515 }
    516 
    517 /*
    518  * Help command
    519  */
    520 void
    521 help(c)
    522 	char c;
    523 {
    524 	esctable_t *p;
    525 
    526 	printf("%c\r\n", c);
    527 	for (p = etable; p->e_char; p++) {
    528 		if ((p->e_flags&PRIV) && uid)
    529 			continue;
    530 		printf("%2s", ctrl(character(value(ESCAPE))));
    531 		printf("%-2s %c   %s\r\n", ctrl(p->e_char),
    532 			p->e_flags&EXP ? '*': ' ', p->e_help);
    533 	}
    534 }
    535 
    536 /*
    537  * Set up the "remote" tty's state
    538  */
    539 void
    540 ttysetup(speed)
    541 	int speed;
    542 {
    543 	struct termios	cntrl;
    544 
    545 	tcgetattr(FD, &cntrl);
    546 	cfsetospeed(&cntrl, speed);
    547 	cfsetispeed(&cntrl, speed);
    548 	cntrl.c_cflag &= ~(CSIZE|PARENB);
    549 	cntrl.c_cflag |= CS8;
    550 	if (DC)
    551 		cntrl.c_cflag |= CLOCAL;
    552 	cntrl.c_iflag &= ~(ISTRIP|ICRNL);
    553 	cntrl.c_oflag &= ~OPOST;
    554 	cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
    555 	cntrl.c_cc[VMIN] = 1;
    556 	cntrl.c_cc[VTIME] = 0;
    557 	if (boolean(value(TAND)))
    558 		cntrl.c_iflag |= IXOFF;
    559 	tcsetattr(FD, TCSAFLUSH, &cntrl);
    560 }
    561 
    562 static char partab[0200];
    563 
    564 /*
    565  * Do a write to the remote machine with the correct parity.
    566  * We are doing 8 bit wide output, so we just generate a character
    567  * with the right parity and output it.
    568  */
    569 void
    570 xpwrite(fd, buf, n)
    571 	int fd;
    572 	char *buf;
    573 	int n;
    574 {
    575 	int i;
    576 	char *bp;
    577 
    578 	bp = buf;
    579 	if (bits8 == 0)
    580 		for (i = 0; i < n; i++) {
    581 			*bp = partab[(*bp) & 0177];
    582 			bp++;
    583 		}
    584 	if (write(fd, buf, n) < 0) {
    585 		if (errno == EIO)
    586 			tipabort("Lost carrier.");
    587 		/* this is questionable */
    588 		perror("write");
    589 	}
    590 }
    591 
    592 /*
    593  * Build a parity table with appropriate high-order bit.
    594  */
    595 void
    596 setparity(defparity)
    597 	char *defparity;
    598 {
    599 	int i, flip, clr, set;
    600 	char *parity;
    601 
    602 	if (value(PARITY) == NULL || (value(PARITY))[0] == '\0')
    603 		value(PARITY) = defparity;
    604 	parity = value(PARITY);
    605 	if (equal(parity, "none")) {
    606 		bits8 = 1;
    607 		return;
    608 	}
    609 	bits8 = 0;
    610 	flip = 0;
    611 	clr = 0377;
    612 	set = 0;
    613 	if (equal(parity, "odd"))
    614 		flip = 0200;			/* reverse bit 7 */
    615 	else if (equal(parity, "zero"))
    616 		clr = 0177;			/* turn off bit 7 */
    617 	else if (equal(parity, "one"))
    618 		set = 0200;			/* turn on bit 7 */
    619 	else if (!equal(parity, "even")) {
    620 		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
    621 		(void) fflush(stderr);
    622 	}
    623 	for (i = 0; i < 0200; i++)
    624 		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
    625 }
    626