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tip.c revision 1.22
      1 /*	$NetBSD: tip.c,v 1.22 1998/12/19 23:00:18 christos 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\n\
     39 	The Regents of the University of California.  All rights reserved.\n");
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)tip.c	8.1 (Berkeley) 6/6/93";
     45 #endif
     46 __RCSID("$NetBSD: tip.c,v 1.22 1998/12/19 23:00:18 christos Exp $");
     47 #endif /* not lint */
     48 
     49 /*
     50  * tip - UNIX link to other systems
     51  *  tip [-v] [-speed] system-name
     52  * or
     53  *  cu phone-number [-s speed] [-l line] [-a acu]
     54  */
     55 #include "tip.h"
     56 #include "pathnames.h"
     57 
     58 /*
     59  * Baud rate mapping table
     60  */
     61 int rates[] = {
     62 	0, 50, 75, 110, 134, 150, 200, 300, 600,
     63 	1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, -1
     64 };
     65 
     66 int	escape __P((void));
     67 int	main __P((int, char **));
     68 void	intprompt __P((int));
     69 void	tipin __P((void));
     70 
     71 char	PNbuf[256];			/* This limits the size of a number */
     72 
     73 int
     74 main(argc, argv)
     75 	int argc;
     76 	char *argv[];
     77 {
     78 	char *system = NULL;
     79 	int i;
     80 	char *p;
     81 	char sbuf[12];
     82 	int fcarg;
     83 
     84 	gid = getgid();
     85 	egid = getegid();
     86 	uid = getuid();
     87 	euid = geteuid();
     88 	if (equal(basename(argv[0]), "cu")) {
     89 		cumode = 1;
     90 		cumain(argc, argv);
     91 		goto cucommon;
     92 	}
     93 
     94 	if (argc > 4) {
     95 		fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
     96 		exit(1);
     97 	}
     98 	if (!isatty(0)) {
     99 		fprintf(stderr, "tip: must be interactive\n");
    100 		exit(1);
    101 	}
    102 
    103 	for (; argc > 1; argv++, argc--) {
    104 		if (argv[1][0] != '-')
    105 			system = argv[1];
    106 		else switch (argv[1][1]) {
    107 
    108 		case 'v':
    109 			vflag++;
    110 			break;
    111 
    112 		case '0': case '1': case '2': case '3': case '4':
    113 		case '5': case '6': case '7': case '8': case '9':
    114 			BR = atoi(&argv[1][1]);
    115 			break;
    116 
    117 		default:
    118 			fprintf(stderr, "tip: %s, unknown option\n", argv[1]);
    119 			break;
    120 		}
    121 	}
    122 
    123 	if (system == NULL)
    124 		goto notnumber;
    125 	if (isalpha((unsigned char)*system))
    126 		goto notnumber;
    127 	/*
    128 	 * System name is really a phone number...
    129 	 * Copy the number then stomp on the original (in case the number
    130 	 *	is private, we don't want 'ps' or 'w' to find it).
    131 	 */
    132 	if (strlen(system) > sizeof PNbuf - 1) {
    133 		fprintf(stderr, "tip: phone number too long (max = %d bytes)\n",
    134 			(int)sizeof(PNbuf) - 1);
    135 		exit(1);
    136 	}
    137 	strncpy(PNbuf, system, sizeof PNbuf - 1);
    138 	PNbuf[sizeof PNbuf - 1] = '\0';
    139 	for (p = system; *p; p++)
    140 		*p = '\0';
    141 	PN = PNbuf;
    142 	(void)snprintf(sbuf, sizeof sbuf, "tip%d", (int)BR);
    143 	system = sbuf;
    144 
    145 notnumber:
    146 	(void)signal(SIGINT, cleanup);
    147 	(void)signal(SIGQUIT, cleanup);
    148 	(void)signal(SIGHUP, cleanup);
    149 	(void)signal(SIGTERM, cleanup);
    150 
    151 	if ((i = hunt(system)) == 0) {
    152 		printf("all ports busy\n");
    153 		exit(3);
    154 	}
    155 	if (i == -1) {
    156 		printf("link down\n");
    157 		(void)uu_unlock(uucplock);
    158 		exit(3);
    159 	}
    160 	setbuf(stdout, NULL);
    161 	loginit();
    162 
    163 	/*
    164 	 * Now that we have the logfile and the ACU open
    165 	 *  return to the real uid and gid.  These things will
    166 	 *  be closed on exit.  Swap real and effective uid's
    167 	 *  so we can get the original permissions back
    168 	 *  for removing the uucp lock.
    169 	 */
    170 	user_uid();
    171 
    172 	/*
    173 	 * Kludge, their's no easy way to get the initialization
    174 	 *   in the right order, so force it here
    175 	 */
    176 	if ((PH = getenv("PHONES")) == NULL)
    177 		PH = _PATH_PHONES;
    178 	vinit();				/* init variables */
    179 	setparity("even");			/* set the parity table */
    180 	if ((i = speed(number(value(BAUDRATE)))) == 0) {
    181 		printf("tip: bad baud rate %d\n", (int)number(value(BAUDRATE)));
    182 		daemon_uid();
    183 		(void)uu_unlock(uucplock);
    184 		exit(3);
    185 	}
    186 
    187 	/*
    188 	 * Hardwired connections require the
    189 	 *  line speed set before they make any transmissions
    190 	 *  (this is particularly true of things like a DF03-AC)
    191 	 */
    192 	if (HW)
    193 		ttysetup(i);
    194 	if ((p = connect()) != NULL) {
    195 		printf("\07%s\n[EOT]\n", p);
    196 		daemon_uid();
    197 		(void)uu_unlock(uucplock);
    198 		exit(1);
    199 	}
    200 	if (!HW)
    201 		ttysetup(i);
    202 
    203 	/*
    204 	 * Direct connections with no carrier require using O_NONBLOCK on
    205 	 * open, but we don't want to keep O_NONBLOCK after open because it
    206 	 * will cause busy waits.
    207 	 */
    208 	if (DC &&
    209 	    ((fcarg = fcntl(FD, F_GETFL, 0)) < 0 ||
    210 	     fcntl(FD, F_SETFL, fcarg & ~O_NONBLOCK) < 0)) {
    211 		printf("tip: can't clear O_NONBLOCK: %s", strerror (errno));
    212 		daemon_uid();
    213 		(void)uu_unlock(uucplock);
    214 		exit(1);
    215 	}
    216 
    217 cucommon:
    218 	/*
    219 	 * From here down the code is shared with
    220 	 * the "cu" version of tip.
    221 	 */
    222 
    223 	tcgetattr(0, &defterm);
    224 	term = defterm;
    225 	term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
    226 	term.c_iflag &= ~(INPCK|ICRNL);
    227 	term.c_oflag &= ~OPOST;
    228 	term.c_cc[VMIN] = 1;
    229 	term.c_cc[VTIME] = 0;
    230 	defchars = term;
    231 	term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
    232 		term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
    233 	 	term.c_cc[VLNEXT] = _POSIX_VDISABLE;
    234 	raw();
    235 
    236 	pipe(fildes); pipe(repdes);
    237 	(void)signal(SIGALRM, alrmtimeout);
    238 
    239 	/*
    240 	 * Everything's set up now:
    241 	 *	connection established (hardwired or dialup)
    242 	 *	line conditioned (baud rate, mode, etc.)
    243 	 *	internal data structures (variables)
    244 	 * so, fork one process for local side and one for remote.
    245 	 */
    246 	printf(cumode ? "Connected\r\n" : "\07connected\r\n");
    247 	switch (pid = fork()) {
    248 	default:
    249 		tipin();
    250 		break;
    251 	case 0:
    252 		tipout();
    253 		break;
    254 	case -1:
    255 		err(1, "can't fork");
    256 	}
    257 	/*NOTREACHED*/
    258 	exit(0);	/* XXX: pacify gcc */
    259 }
    260 
    261 void
    262 cleanup(dummy)
    263 	int dummy;
    264 {
    265 
    266 	daemon_uid();
    267 	(void)uu_unlock(uucplock);
    268 	if (odisc)
    269 		ioctl(0, TIOCSETD, (char *)&odisc);
    270 	exit(0);
    271 }
    272 
    273 /*
    274  * Muck with user ID's.  We are setuid to the owner of the lock
    275  * directory when we start.  user_uid() reverses real and effective
    276  * ID's after startup, to run with the user's permissions.
    277  * daemon_uid() switches back to the privileged uid for unlocking.
    278  * Finally, to avoid running a shell with the wrong real uid,
    279  * shell_uid() sets real and effective uid's to the user's real ID.
    280  */
    281 static int uidswapped;
    282 
    283 void
    284 user_uid()
    285 {
    286 
    287 	if (uidswapped == 0) {
    288 		seteuid(uid);
    289 		uidswapped = 1;
    290 	}
    291 }
    292 
    293 void
    294 daemon_uid()
    295 {
    296 
    297 	if (uidswapped) {
    298 		seteuid(euid);
    299 		uidswapped = 0;
    300 	}
    301 }
    302 
    303 void
    304 shell_uid()
    305 {
    306 
    307 	seteuid(uid);
    308 }
    309 
    310 /*
    311  * put the controlling keyboard into raw mode
    312  */
    313 void
    314 raw()
    315 {
    316 
    317 	tcsetattr(0, TCSADRAIN, &term);
    318 }
    319 
    320 
    321 /*
    322  * return keyboard to normal mode
    323  */
    324 void
    325 unraw()
    326 {
    327 
    328 	tcsetattr(0, TCSADRAIN, &defterm);
    329 }
    330 
    331 static	jmp_buf promptbuf;
    332 
    333 /*
    334  * Print string ``s'', then read a string
    335  *  in from the terminal.  Handles signals & allows use of
    336  *  normal erase and kill characters.
    337  */
    338 int
    339 prompt(s, p, l)
    340 	char *s;
    341 	char *p;
    342 	size_t l;
    343 {
    344 	int c;
    345 	char *b = p;
    346 	sig_t oint, oquit;
    347 
    348 #if __GNUC__		/* XXX: pacify gcc */
    349 	(void)&p;
    350 #endif
    351 
    352 	stoprompt = 0;
    353 	oint = signal(SIGINT, intprompt);
    354 	oquit = signal(SIGQUIT, SIG_IGN);
    355 	unraw();
    356 	printf("%s", s);
    357 	if (setjmp(promptbuf) == 0)
    358 		while ((c = getchar()) != -1 && (*p = c) != '\n' &&
    359 		    b + l > p)
    360 			p++;
    361 	*p = '\0';
    362 
    363 	raw();
    364 	(void)signal(SIGINT, oint);
    365 	(void)signal(SIGQUIT, oquit);
    366 	return (stoprompt || p == b);
    367 }
    368 
    369 /*
    370  * Interrupt service routine during prompting
    371  */
    372 void
    373 intprompt(dummy)
    374 	int dummy;
    375 {
    376 
    377 	(void)signal(SIGINT, SIG_IGN);
    378 	stoprompt = 1;
    379 	printf("\r\n");
    380 	longjmp(promptbuf, 1);
    381 }
    382 
    383 /*
    384  * ****TIPIN   TIPIN****
    385  */
    386 void
    387 tipin()
    388 {
    389 	char gch, bol = 1;
    390 
    391 	/*
    392 	 * Kinda klugey here...
    393 	 *   check for scripting being turned on from the .tiprc file,
    394 	 *   but be careful about just using setscript(), as we may
    395 	 *   send a SIGEMT before tipout has a chance to set up catching
    396 	 *   it; so wait a second, then setscript()
    397 	 */
    398 	if (boolean(value(SCRIPT))) {
    399 		sleep(1);
    400 		setscript();
    401 	}
    402 
    403 	while (1) {
    404 		gch = getchar()&STRIP_PAR;
    405 		if ((gch == character(value(ESCAPE))) && bol) {
    406 			if (!(gch = escape()))
    407 				continue;
    408 		} else if (!cumode &&
    409 		    gch && gch == character(value(RAISECHAR))) {
    410 			setboolean(value(RAISE), !boolean(value(RAISE)));
    411 			continue;
    412 		} else if (gch == '\r') {
    413 			bol = 1;
    414 			xpwrite(FD, &gch, 1);
    415 			if (boolean(value(HALFDUPLEX)))
    416 				printf("\r\n");
    417 			continue;
    418 		} else if (!cumode && gch && gch == character(value(FORCE)))
    419 			gch = getchar()&STRIP_PAR;
    420 		bol = any(gch, value(EOL));
    421 		if (boolean(value(RAISE)) && islower((unsigned char)gch))
    422 			gch = toupper(gch);
    423 		xpwrite(FD, &gch, 1);
    424 		if (boolean(value(HALFDUPLEX)))
    425 			printf("%c", gch);
    426 	}
    427 }
    428 
    429 /*
    430  * Escape handler --
    431  *  called on recognition of ``escapec'' at the beginning of a line
    432  */
    433 int
    434 escape()
    435 {
    436 	char gch;
    437 	esctable_t *p;
    438 	char c = character(value(ESCAPE));
    439 
    440 	gch = (getchar()&STRIP_PAR);
    441 	for (p = etable; p->e_char; p++)
    442 		if (p->e_char == gch) {
    443 			if ((p->e_flags&PRIV) && uid)
    444 				continue;
    445 			printf("%s", ctrl(c));
    446 			(*p->e_func)(gch);
    447 			return (0);
    448 		}
    449 	/* ESCAPE ESCAPE forces ESCAPE */
    450 	if (c != gch)
    451 		xpwrite(FD, &c, 1);
    452 	return (gch);
    453 }
    454 
    455 int
    456 speed(n)
    457 	int n;
    458 {
    459 	int *p;
    460 
    461 	for (p = rates; *p != -1;  p++)
    462 		if (*p == n)
    463 			return n;
    464 	return 0;
    465 }
    466 
    467 int
    468 any(c, p)
    469 	char c, *p;
    470 {
    471 
    472 	while (p && *p)
    473 		if (*p++ == c)
    474 			return (1);
    475 	return (0);
    476 }
    477 
    478 char *
    479 interp(s)
    480 	char *s;
    481 {
    482 	static char buf[256];
    483 	char *p = buf, c, *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(speed)
    545 	int speed;
    546 {
    547 	struct termios	cntrl;
    548 
    549 	tcgetattr(FD, &cntrl);
    550 	cfsetospeed(&cntrl, speed);
    551 	cfsetispeed(&cntrl, speed);
    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 	char *defparity;
    602 {
    603 	int i, flip, clr, set;
    604 	char *parity;
    605 
    606 	if (value(PARITY) == NULL || (value(PARITY))[0] == '\0')
    607 		value(PARITY) = defparity;
    608 	parity = value(PARITY);
    609 	if (equal(parity, "none")) {
    610 		bits8 = 1;
    611 		return;
    612 	}
    613 	bits8 = 0;
    614 	flip = 0;
    615 	clr = 0377;
    616 	set = 0;
    617 	if (equal(parity, "odd"))
    618 		flip = 0200;			/* reverse bit 7 */
    619 	else if (equal(parity, "zero"))
    620 		clr = 0177;			/* turn off bit 7 */
    621 	else if (equal(parity, "one"))
    622 		set = 0200;			/* turn on bit 7 */
    623 	else if (!equal(parity, "even")) {
    624 		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
    625 		(void) fflush(stderr);
    626 	}
    627 	for (i = 0; i < 0200; i++)
    628 		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
    629 }
    630