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tip.c revision 1.19 
      1 /*	$NetBSD: tip.c,v 1.19 1997/12/17 17:09:33 mellon 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 1.19 1997/12/17 17:09:33 mellon 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	disc = TTYDISC;		/* tip normally runs this way */
     67 
     68 int	escape __P((void));
     69 int	main __P((int, char **));
     70 void	intprompt __P((int));
     71 void	tipin __P((void));
     72 
     73 char	PNbuf[256];			/* This limits the size of a number */
     74 
     75 int
     76 main(argc, argv)
     77 	int argc;
     78 	char *argv[];
     79 {
     80 	char *system = NULL;
     81 	int i;
     82 	char *p;
     83 	char sbuf[12];
     84 	int fcarg;
     85 
     86 	gid = getgid();
     87 	egid = getegid();
     88 	uid = getuid();
     89 	euid = geteuid();
     90 	if (equal(basename(argv[0]), "cu")) {
     91 		cumode = 1;
     92 		cumain(argc, argv);
     93 		goto cucommon;
     94 	}
     95 
     96 	if (argc > 4) {
     97 		fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
     98 		exit(1);
     99 	}
    100 	if (!isatty(0)) {
    101 		fprintf(stderr, "tip: must be interactive\n");
    102 		exit(1);
    103 	}
    104 
    105 	for (; argc > 1; argv++, argc--) {
    106 		if (argv[1][0] != '-')
    107 			system = argv[1];
    108 		else switch (argv[1][1]) {
    109 
    110 		case 'v':
    111 			vflag++;
    112 			break;
    113 
    114 		case '0': case '1': case '2': case '3': case '4':
    115 		case '5': case '6': case '7': case '8': case '9':
    116 			BR = atoi(&argv[1][1]);
    117 			break;
    118 
    119 		default:
    120 			fprintf(stderr, "tip: %s, unknown option\n", argv[1]);
    121 			break;
    122 		}
    123 	}
    124 
    125 	if (system == NULL)
    126 		goto notnumber;
    127 	if (isalpha(*system))
    128 		goto notnumber;
    129 	/*
    130 	 * System name is really a phone number...
    131 	 * Copy the number then stomp on the original (in case the number
    132 	 *	is private, we don't want 'ps' or 'w' to find it).
    133 	 */
    134 	if (strlen(system) > sizeof PNbuf - 1) {
    135 		fprintf(stderr, "tip: phone number too long (max = %d bytes)\n",
    136 			(int)sizeof(PNbuf) - 1);
    137 		exit(1);
    138 	}
    139 	strncpy( PNbuf, system, sizeof PNbuf - 1 );
    140 	for (p = system; *p; p++)
    141 		*p = '\0';
    142 	PN = PNbuf;
    143 	(void)snprintf(sbuf, sizeof sbuf, "tip%d", (int)BR);
    144 	system = sbuf;
    145 
    146 notnumber:
    147 	(void)signal(SIGINT, cleanup);
    148 	(void)signal(SIGQUIT, cleanup);
    149 	(void)signal(SIGHUP, cleanup);
    150 	(void)signal(SIGTERM, cleanup);
    151 
    152 	if ((i = hunt(system)) == 0) {
    153 		printf("all ports busy\n");
    154 		exit(3);
    155 	}
    156 	if (i == -1) {
    157 		printf("link down\n");
    158 		(void)uu_unlock(uucplock);
    159 		exit(3);
    160 	}
    161 	setbuf(stdout, NULL);
    162 	loginit();
    163 
    164 	/*
    165 	 * Now that we have the logfile and the ACU open
    166 	 *  return to the real uid and gid.  These things will
    167 	 *  be closed on exit.  Swap real and effective uid's
    168 	 *  so we can get the original permissions back
    169 	 *  for removing the uucp lock.
    170 	 */
    171 	user_uid();
    172 
    173 	/*
    174 	 * Kludge, their's no easy way to get the initialization
    175 	 *   in the right order, so force it here
    176 	 */
    177 	if ((PH = getenv("PHONES")) == NULL)
    178 		PH = _PATH_PHONES;
    179 	vinit();				/* init variables */
    180 	setparity("even");			/* set the parity table */
    181 	if ((i = speed(number(value(BAUDRATE)))) == 0) {
    182 		printf("tip: bad baud rate %d\n", (int)number(value(BAUDRATE)));
    183 		daemon_uid();
    184 		(void)uu_unlock(uucplock);
    185 		exit(3);
    186 	}
    187 
    188 	/*
    189 	 * Hardwired connections require the
    190 	 *  line speed set before they make any transmissions
    191 	 *  (this is particularly true of things like a DF03-AC)
    192 	 */
    193 	if (HW)
    194 		ttysetup(i);
    195 	if ((p = connect()) != NULL) {
    196 		printf("\07%s\n[EOT]\n", p);
    197 		daemon_uid();
    198 		(void)uu_unlock(uucplock);
    199 		exit(1);
    200 	}
    201 	if (!HW)
    202 		ttysetup(i);
    203 
    204 	/*
    205 	 * Direct connections with no carrier require using O_NONBLOCK on
    206 	 * open, but we don't want to keep O_NONBLOCK after open because it
    207 	 * will cause busy waits.
    208 	 */
    209 	if (DC &&
    210 	    ((fcarg = fcntl(FD, F_GETFL, 0)) < 0 ||
    211 	     fcntl(FD, F_SETFL, fcarg & ~O_NONBLOCK) < 0)) {
    212 		printf("tip: can't clear O_NONBLOCK: %s", strerror (errno));
    213 		daemon_uid();
    214 		(void)uu_unlock (uucplock);
    215 		exit(1);
    216 	}
    217 
    218 cucommon:
    219 	/*
    220 	 * From here down the code is shared with
    221 	 * the "cu" version of tip.
    222 	 */
    223 
    224 	tcgetattr(0, &defterm);
    225 	term = defterm;
    226 	term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
    227 	term.c_iflag &= ~(INPCK|ICRNL);
    228 	term.c_oflag &= ~OPOST;
    229 	term.c_cc[VMIN] = 1;
    230 	term.c_cc[VTIME] = 0;
    231 	defchars = term;
    232 	term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
    233 		term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
    234 	 	term.c_cc[VLNEXT] = _POSIX_VDISABLE;
    235 	raw();
    236 
    237 	pipe(fildes); pipe(repdes);
    238 	(void)signal(SIGALRM, alrmtimeout);
    239 
    240 	/*
    241 	 * Everything's set up now:
    242 	 *	connection established (hardwired or dialup)
    243 	 *	line conditioned (baud rate, mode, etc.)
    244 	 *	internal data structures (variables)
    245 	 * so, fork one process for local side and one for remote.
    246 	 */
    247 	printf(cumode ? "Connected\r\n" : "\07connected\r\n");
    248 	switch (pid = fork()) {
    249 	default:
    250 		tipin();
    251 		break;
    252 	case 0:
    253 		tipout();
    254 		break;
    255 	case -1:
    256 		err(1, "can't fork");
    257 	}
    258 	/*NOTREACHED*/
    259 	exit(0);	/* XXX: pacify gcc */
    260 }
    261 
    262 void
    263 cleanup(dummy)
    264 	int dummy;
    265 {
    266 
    267 	daemon_uid();
    268 	(void)uu_unlock(uucplock);
    269 	if (odisc)
    270 		ioctl(0, TIOCSETD, (char *)&odisc);
    271 	exit(0);
    272 }
    273 
    274 /*
    275  * Muck with user ID's.  We are setuid to the owner of the lock
    276  * directory when we start.  user_uid() reverses real and effective
    277  * ID's after startup, to run with the user's permissions.
    278  * daemon_uid() switches back to the privileged uid for unlocking.
    279  * Finally, to avoid running a shell with the wrong real uid,
    280  * shell_uid() sets real and effective uid's to the user's real ID.
    281  */
    282 static int uidswapped;
    283 
    284 void
    285 user_uid()
    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 	seteuid(uid);
    307 }
    308 
    309 /*
    310  * put the controlling keyboard into raw mode
    311  */
    312 void
    313 raw()
    314 {
    315 	tcsetattr(0, TCSADRAIN, &term);
    316 }
    317 
    318 
    319 /*
    320  * return keyboard to normal mode
    321  */
    322 void
    323 unraw()
    324 {
    325 	tcsetattr(0, TCSADRAIN, &defterm);
    326 }
    327 
    328 static	jmp_buf promptbuf;
    329 
    330 /*
    331  * Print string ``s'', then read a string
    332  *  in from the terminal.  Handles signals & allows use of
    333  *  normal erase and kill characters.
    334  */
    335 int
    336 prompt(s, p)
    337 	char *s;
    338 	char *p;
    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 			p++;
    356 	*p = '\0';
    357 
    358 	raw();
    359 	(void)signal(SIGINT, oint);
    360 	(void)signal(SIGQUIT, oquit);
    361 	return (stoprompt || p == b);
    362 }
    363 
    364 /*
    365  * Interrupt service routine during prompting
    366  */
    367 void
    368 intprompt(dummy)
    369 	int dummy;
    370 {
    371 
    372 	(void)signal(SIGINT, SIG_IGN);
    373 	stoprompt = 1;
    374 	printf("\r\n");
    375 	longjmp(promptbuf, 1);
    376 }
    377 
    378 /*
    379  * ****TIPIN   TIPIN****
    380  */
    381 void
    382 tipin()
    383 {
    384 	char gch, bol = 1;
    385 
    386 	/*
    387 	 * Kinda klugey here...
    388 	 *   check for scripting being turned on from the .tiprc file,
    389 	 *   but be careful about just using setscript(), as we may
    390 	 *   send a SIGEMT before tipout has a chance to set up catching
    391 	 *   it; so wait a second, then setscript()
    392 	 */
    393 	if (boolean(value(SCRIPT))) {
    394 		sleep(1);
    395 		setscript();
    396 	}
    397 
    398 	while (1) {
    399 		gch = getchar()&STRIP_PAR;
    400 		if ((gch == character(value(ESCAPE))) && bol) {
    401 			if (!(gch = escape()))
    402 				continue;
    403 		} else if (!cumode &&
    404 		    gch && gch == character(value(RAISECHAR))) {
    405 			setboolean(value(RAISE), !boolean(value(RAISE)));
    406 			continue;
    407 		} else if (gch == '\r') {
    408 			bol = 1;
    409 			pwrite(FD, &gch, 1);
    410 			if (boolean(value(HALFDUPLEX)))
    411 				printf("\r\n");
    412 			continue;
    413 		} else if (!cumode && gch && gch == character(value(FORCE)))
    414 			gch = getchar()&STRIP_PAR;
    415 		bol = any(gch, value(EOL));
    416 		if (boolean(value(RAISE)) && islower(gch))
    417 			gch = toupper(gch);
    418 		pwrite(FD, &gch, 1);
    419 		if (boolean(value(HALFDUPLEX)))
    420 			printf("%c", gch);
    421 	}
    422 }
    423 
    424 /*
    425  * Escape handler --
    426  *  called on recognition of ``escapec'' at the beginning of a line
    427  */
    428 int
    429 escape()
    430 {
    431 	char gch;
    432 	esctable_t *p;
    433 	char c = character(value(ESCAPE));
    434 
    435 	gch = (getchar()&STRIP_PAR);
    436 	for (p = etable; p->e_char; p++)
    437 		if (p->e_char == gch) {
    438 			if ((p->e_flags&PRIV) && uid)
    439 				continue;
    440 			printf("%s", ctrl(c));
    441 			(*p->e_func)(gch);
    442 			return (0);
    443 		}
    444 	/* ESCAPE ESCAPE forces ESCAPE */
    445 	if (c != gch)
    446 		pwrite(FD, &c, 1);
    447 	return (gch);
    448 }
    449 
    450 int
    451 speed(n)
    452 	int n;
    453 {
    454 	int *p;
    455 
    456 	for (p = rates; *p != -1;  p++)
    457 		if (*p == n)
    458 			return n;
    459 	return 0;
    460 }
    461 
    462 int
    463 any(c, p)
    464 	char c, *p;
    465 {
    466 	while (p && *p)
    467 		if (*p++ == c)
    468 			return (1);
    469 	return (0);
    470 }
    471 
    472 char *
    473 interp(s)
    474 	char *s;
    475 {
    476 	static char buf[256];
    477 	char *p = buf, c, *q;
    478 
    479 	while ((c = *s++) != 0) {
    480 		for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
    481 			if (*q++ == c) {
    482 				*p++ = '\\'; *p++ = *q;
    483 				goto next;
    484 			}
    485 		if (c < 040) {
    486 			*p++ = '^'; *p++ = c + 'A'-1;
    487 		} else if (c == 0177) {
    488 			*p++ = '^'; *p++ = '?';
    489 		} else
    490 			*p++ = c;
    491 	next:
    492 		;
    493 	}
    494 	*p = '\0';
    495 	return (buf);
    496 }
    497 
    498 char *
    499 ctrl(c)
    500 	char c;
    501 {
    502 	static char s[3];
    503 
    504 	if (c < 040 || c == 0177) {
    505 		s[0] = '^';
    506 		s[1] = c == 0177 ? '?' : c+'A'-1;
    507 		s[2] = '\0';
    508 	} else {
    509 		s[0] = c;
    510 		s[1] = '\0';
    511 	}
    512 	return (s);
    513 }
    514 
    515 /*
    516  * Help command
    517  */
    518 void
    519 help(c)
    520 	char c;
    521 {
    522 	esctable_t *p;
    523 
    524 	printf("%c\r\n", c);
    525 	for (p = etable; p->e_char; p++) {
    526 		if ((p->e_flags&PRIV) && uid)
    527 			continue;
    528 		printf("%2s", ctrl(character(value(ESCAPE))));
    529 		printf("%-2s %c   %s\r\n", ctrl(p->e_char),
    530 			p->e_flags&EXP ? '*': ' ', p->e_help);
    531 	}
    532 }
    533 
    534 /*
    535  * Set up the "remote" tty's state
    536  */
    537 void
    538 ttysetup(speed)
    539 	int speed;
    540 {
    541 	struct termios	cntrl;
    542 
    543 	tcgetattr(FD, &cntrl);
    544 	cfsetospeed(&cntrl, speed);
    545 	cfsetispeed(&cntrl, speed);
    546 	cntrl.c_cflag &= ~(CSIZE|PARENB);
    547 	cntrl.c_cflag |= CS8;
    548 	if (DC)
    549 		cntrl.c_cflag |= CLOCAL;
    550 	cntrl.c_iflag &= ~(ISTRIP|ICRNL);
    551 	cntrl.c_oflag &= ~OPOST;
    552 	cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
    553 	cntrl.c_cc[VMIN] = 1;
    554 	cntrl.c_cc[VTIME] = 0;
    555 	if (boolean(value(TAND)))
    556 		cntrl.c_iflag |= IXOFF;
    557 	tcsetattr(FD, TCSAFLUSH, &cntrl);
    558 }
    559 
    560 static char partab[0200];
    561 
    562 /*
    563  * Do a write to the remote machine with the correct parity.
    564  * We are doing 8 bit wide output, so we just generate a character
    565  * with the right parity and output it.
    566  */
    567 void
    568 pwrite(fd, buf, n)
    569 	int fd;
    570 	char *buf;
    571 	int n;
    572 {
    573 	int i;
    574 	char *bp;
    575 
    576 	bp = buf;
    577 	if (bits8 == 0)
    578 		for (i = 0; i < n; i++) {
    579 			*bp = partab[(*bp) & 0177];
    580 			bp++;
    581 		}
    582 	if (write(fd, buf, n) < 0) {
    583 		if (errno == EIO)
    584 			tipabort("Lost carrier.");
    585 		/* this is questionable */
    586 		perror("write");
    587 	}
    588 }
    589 
    590 /*
    591  * Build a parity table with appropriate high-order bit.
    592  */
    593 void
    594 setparity(defparity)
    595 	char *defparity;
    596 {
    597 	int i, flip, clr, set;
    598 	char *parity;
    599 
    600 	if (value(PARITY) == NULL || (value(PARITY))[0] == '\0')
    601 		value(PARITY) = defparity;
    602 	parity = value(PARITY);
    603 	if (equal(parity, "none")) {
    604 		bits8 = 1;
    605 		return;
    606 	}
    607 	bits8 = 0;
    608 	flip = 0;
    609 	clr = 0377;
    610 	set = 0;
    611 	if (equal(parity, "odd"))
    612 		flip = 0200;			/* reverse bit 7 */
    613 	else if (equal(parity, "zero"))
    614 		clr = 0177;			/* turn off bit 7 */
    615 	else if (equal(parity, "one"))
    616 		set = 0200;			/* turn on bit 7 */
    617 	else if (!equal(parity, "even")) {
    618 		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
    619 		(void) fflush(stderr);
    620 	}
    621 	for (i = 0; i < 0200; i++)
    622 		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
    623 }
    624