xref: /netbsd-src/usr.bin/tip/tip.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*	$NetBSD: tip.c,v 1.26 2004/04/23 22:24:34 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. 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 1.26 2004/04/23 22:24:34 christos 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 	strncpy(PNbuf, System, sizeof PNbuf - 1);
137 	PNbuf[sizeof PNbuf - 1] = '\0';
138 	for (p = System; *p; p++)
139 		*p = '\0';
140 	PN = PNbuf;
141 	(void)snprintf(sbuf, sizeof sbuf, "tip%d", (int)BR);
142 	System = sbuf;
143 
144 notnumber:
145 	(void)signal(SIGINT, cleanup);
146 	(void)signal(SIGQUIT, cleanup);
147 	(void)signal(SIGHUP, cleanup);
148 	(void)signal(SIGTERM, cleanup);
149 
150 	if ((i = hunt(System)) == 0) {
151 		printf("all ports busy\n");
152 		exit(3);
153 	}
154 	if (i == -1) {
155 		printf("link down\n");
156 		(void)uu_unlock(uucplock);
157 		exit(3);
158 	}
159 	setbuf(stdout, NULL);
160 	loginit();
161 
162 	/*
163 	 * Now that we have the logfile and the ACU open
164 	 *  return to the real uid and gid.  These things will
165 	 *  be closed on exit.  Swap real and effective uid's
166 	 *  so we can get the original permissions back
167 	 *  for removing the uucp lock.
168 	 */
169 	user_uid();
170 
171 	/*
172 	 * Kludge, their's no easy way to get the initialization
173 	 *   in the right order, so force it here
174 	 */
175 	if ((PH = getenv("PHONES")) == NULL)
176 		PH = path_phones;
177 	vinit();				/* init variables */
178 	setparity("even");			/* set the parity table */
179 	if ((i = speed(number(value(BAUDRATE)))) == 0) {
180 		printf("tip: bad baud rate %d\n", (int)number(value(BAUDRATE)));
181 		daemon_uid();
182 		(void)uu_unlock(uucplock);
183 		exit(3);
184 	}
185 
186 	/*
187 	 * Hardwired connections require the
188 	 *  line speed set before they make any transmissions
189 	 *  (this is particularly true of things like a DF03-AC)
190 	 */
191 	if (HW)
192 		ttysetup(i);
193 	if ((q = connect()) != NULL) {
194 		printf("\07%s\n[EOT]\n", q);
195 		daemon_uid();
196 		(void)uu_unlock(uucplock);
197 		exit(1);
198 	}
199 	if (!HW)
200 		ttysetup(i);
201 
202 	/*
203 	 * Direct connections with no carrier require using O_NONBLOCK on
204 	 * open, but we don't want to keep O_NONBLOCK after open because it
205 	 * will cause busy waits.
206 	 */
207 	if (DC &&
208 	    ((fcarg = fcntl(FD, F_GETFL, 0)) < 0 ||
209 	     fcntl(FD, F_SETFL, fcarg & ~O_NONBLOCK) < 0)) {
210 		printf("tip: can't clear O_NONBLOCK: %s", strerror (errno));
211 		daemon_uid();
212 		(void)uu_unlock(uucplock);
213 		exit(1);
214 	}
215 
216 cucommon:
217 	/*
218 	 * From here down the code is shared with
219 	 * the "cu" version of tip.
220 	 */
221 
222 	tcgetattr(0, &defterm);
223 	term = defterm;
224 	term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
225 	term.c_iflag &= ~(INPCK|ICRNL);
226 	term.c_oflag &= ~OPOST;
227 	term.c_cc[VMIN] = 1;
228 	term.c_cc[VTIME] = 0;
229 	defchars = term;
230 	term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
231 		term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
232 	 	term.c_cc[VLNEXT] = _POSIX_VDISABLE;
233 	raw();
234 
235 	pipe(fildes); pipe(repdes);
236 	(void)signal(SIGALRM, alrmtimeout);
237 
238 	/*
239 	 * Everything's set up now:
240 	 *	connection established (hardwired or dialup)
241 	 *	line conditioned (baud rate, mode, etc.)
242 	 *	internal data structures (variables)
243 	 * so, fork one process for local side and one for remote.
244 	 */
245 	printf("%s", cumode ? "Connected\r\n" : "\07connected\r\n");
246 	switch (pid = fork()) {
247 	default:
248 		tipin();
249 		break;
250 	case 0:
251 		tipout();
252 		break;
253 	case -1:
254 		err(1, "can't fork");
255 	}
256 	/*NOTREACHED*/
257 	exit(0);	/* XXX: pacify gcc */
258 }
259 
260 void
261 cleanup(dummy)
262 	int dummy;
263 {
264 
265 	daemon_uid();
266 	(void)uu_unlock(uucplock);
267 	if (odisc)
268 		ioctl(0, TIOCSETD, (char *)&odisc);
269 	exit(0);
270 }
271 
272 /*
273  * Muck with user ID's.  We are setuid to the owner of the lock
274  * directory when we start.  user_uid() reverses real and effective
275  * ID's after startup, to run with the user's permissions.
276  * daemon_uid() switches back to the privileged uid for unlocking.
277  * Finally, to avoid running a shell with the wrong real uid,
278  * shell_uid() sets real and effective uid's to the user's real ID.
279  */
280 static int uidswapped;
281 
282 void
283 user_uid()
284 {
285 
286 	if (uidswapped == 0) {
287 		seteuid(uid);
288 		uidswapped = 1;
289 	}
290 }
291 
292 void
293 daemon_uid()
294 {
295 
296 	if (uidswapped) {
297 		seteuid(euid);
298 		uidswapped = 0;
299 	}
300 }
301 
302 void
303 shell_uid()
304 {
305 
306 	seteuid(uid);
307 }
308 
309 /*
310  * put the controlling keyboard into raw mode
311  */
312 void
313 raw()
314 {
315 
316 	tcsetattr(0, TCSADRAIN, &term);
317 }
318 
319 
320 /*
321  * return keyboard to normal mode
322  */
323 void
324 unraw()
325 {
326 
327 	tcsetattr(0, TCSADRAIN, &defterm);
328 }
329 
330 static	jmp_buf promptbuf;
331 
332 /*
333  * Print string ``s'', then read a string
334  *  in from the terminal.  Handles signals & allows use of
335  *  normal erase and kill characters.
336  */
337 int
338 prompt(s, p, l)
339 	const char *s;
340 	char *p;
341 	size_t l;
342 {
343 	int c;
344 	char *b = p;
345 	sig_t oint, oquit;
346 
347 #if __GNUC__		/* XXX: pacify gcc */
348 	(void)&p;
349 #endif
350 
351 	stoprompt = 0;
352 	oint = signal(SIGINT, intprompt);
353 	oquit = signal(SIGQUIT, SIG_IGN);
354 	unraw();
355 	printf("%s", s);
356 	if (setjmp(promptbuf) == 0)
357 		while ((c = getchar()) != -1 && (*p = c) != '\n' &&
358 		    b + l > p)
359 			p++;
360 	*p = '\0';
361 
362 	raw();
363 	(void)signal(SIGINT, oint);
364 	(void)signal(SIGQUIT, oquit);
365 	return (stoprompt || p == b);
366 }
367 
368 /*
369  * Interrupt service routine during prompting
370  */
371 void
372 intprompt(dummy)
373 	int dummy;
374 {
375 
376 	(void)signal(SIGINT, SIG_IGN);
377 	stoprompt = 1;
378 	printf("\r\n");
379 	longjmp(promptbuf, 1);
380 }
381 
382 /*
383  * ****TIPIN   TIPIN****
384  */
385 void
386 tipin()
387 {
388 	char gch, bol = 1;
389 
390 	/*
391 	 * Kinda klugey here...
392 	 *   check for scripting being turned on from the .tiprc file,
393 	 *   but be careful about just using setscript(), as we may
394 	 *   send a SIGEMT before tipout has a chance to set up catching
395 	 *   it; so wait a second, then setscript()
396 	 */
397 	if (boolean(value(SCRIPT))) {
398 		sleep(1);
399 		setscript();
400 	}
401 
402 	while (1) {
403 		gch = getchar()&STRIP_PAR;
404 		if ((gch == character(value(ESCAPE))) && bol) {
405 			if (!(gch = escape()))
406 				continue;
407 		} else if (!cumode &&
408 		    gch && gch == character(value(RAISECHAR))) {
409 			setboolean(value(RAISE), !boolean(value(RAISE)));
410 			continue;
411 		} else if (gch == '\r') {
412 			bol = 1;
413 			xpwrite(FD, &gch, 1);
414 			if (boolean(value(HALFDUPLEX)))
415 				printf("\r\n");
416 			continue;
417 		} else if (!cumode && gch && gch == character(value(FORCE)))
418 			gch = getchar()&STRIP_PAR;
419 		bol = any(gch, value(EOL));
420 		if (boolean(value(RAISE)) && islower((unsigned char)gch))
421 			gch = toupper(gch);
422 		xpwrite(FD, &gch, 1);
423 		if (boolean(value(HALFDUPLEX)))
424 			printf("%c", gch);
425 	}
426 }
427 
428 /*
429  * Escape handler --
430  *  called on recognition of ``escapec'' at the beginning of a line
431  */
432 int
433 escape()
434 {
435 	char gch;
436 	esctable_t *p;
437 	char c = character(value(ESCAPE));
438 
439 	gch = (getchar()&STRIP_PAR);
440 	for (p = etable; p->e_char; p++)
441 		if (p->e_char == gch) {
442 			if ((p->e_flags&PRIV) && uid)
443 				continue;
444 			printf("%s", ctrl(c));
445 			(*p->e_func)(gch);
446 			return (0);
447 		}
448 	/* ESCAPE ESCAPE forces ESCAPE */
449 	if (c != gch)
450 		xpwrite(FD, &c, 1);
451 	return (gch);
452 }
453 
454 int
455 speed(n)
456 	int n;
457 {
458 	int *p;
459 
460 	for (p = rates; *p != -1;  p++)
461 		if (*p == n)
462 			return n;
463 	return 0;
464 }
465 
466 int
467 any(c, p)
468 	char c;
469 	const char *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 	const char *s;
481 {
482 	static char buf[256];
483 	char *p = buf, c;
484 	const char *q;
485 
486 	while ((c = *s++) != 0 && buf + sizeof buf - p > 2) {
487 		for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
488 			if (*q++ == c) {
489 				*p++ = '\\'; *p++ = *q;
490 				goto next;
491 			}
492 		if (c < 040) {
493 			*p++ = '^'; *p++ = c + 'A'-1;
494 		} else if (c == 0177) {
495 			*p++ = '^'; *p++ = '?';
496 		} else
497 			*p++ = c;
498 	next:
499 		;
500 	}
501 	*p = '\0';
502 	return (buf);
503 }
504 
505 char *
506 ctrl(c)
507 	char c;
508 {
509 	static char s[3];
510 
511 	if (c < 040 || c == 0177) {
512 		s[0] = '^';
513 		s[1] = c == 0177 ? '?' : c+'A'-1;
514 		s[2] = '\0';
515 	} else {
516 		s[0] = c;
517 		s[1] = '\0';
518 	}
519 	return (s);
520 }
521 
522 /*
523  * Help command
524  */
525 void
526 help(c)
527 	char c;
528 {
529 	esctable_t *p;
530 
531 	printf("%c\r\n", c);
532 	for (p = etable; p->e_char; p++) {
533 		if ((p->e_flags&PRIV) && uid)
534 			continue;
535 		printf("%2s", ctrl(character(value(ESCAPE))));
536 		printf("%-2s %c   %s\r\n", ctrl(p->e_char),
537 			p->e_flags&EXP ? '*': ' ', p->e_help);
538 	}
539 }
540 
541 /*
542  * Set up the "remote" tty's state
543  */
544 void
545 ttysetup(spd)
546 	int spd;
547 {
548 	struct termios	cntrl;
549 
550 	tcgetattr(FD, &cntrl);
551 	cfsetospeed(&cntrl, spd);
552 	cfsetispeed(&cntrl, spd);
553 	cntrl.c_cflag &= ~(CSIZE|PARENB);
554 	cntrl.c_cflag |= CS8;
555 	if (DC)
556 		cntrl.c_cflag |= CLOCAL;
557 	cntrl.c_iflag &= ~(ISTRIP|ICRNL);
558 	cntrl.c_oflag &= ~OPOST;
559 	cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
560 	cntrl.c_cc[VMIN] = 1;
561 	cntrl.c_cc[VTIME] = 0;
562 	if (boolean(value(TAND)))
563 		cntrl.c_iflag |= IXOFF;
564 	tcsetattr(FD, TCSAFLUSH, &cntrl);
565 }
566 
567 static char partab[0200];
568 
569 /*
570  * Do a write to the remote machine with the correct parity.
571  * We are doing 8 bit wide output, so we just generate a character
572  * with the right parity and output it.
573  */
574 void
575 xpwrite(fd, buf, n)
576 	int fd;
577 	char *buf;
578 	int n;
579 {
580 	int i;
581 	char *bp;
582 
583 	bp = buf;
584 	if (bits8 == 0)
585 		for (i = 0; i < n; i++) {
586 			*bp = partab[(*bp) & 0177];
587 			bp++;
588 		}
589 	if (write(fd, buf, n) < 0) {
590 		if (errno == EIO)
591 			tipabort("Lost carrier.");
592 		/* this is questionable */
593 		perror("write");
594 	}
595 }
596 
597 /*
598  * Build a parity table with appropriate high-order bit.
599  */
600 void
601 setparity(defparity)
602 	const char *defparity;
603 {
604 	int i, flip, clr, set;
605 	const char *parity;
606 	static char *curpar;
607 
608 	if (value(PARITY) == NULL || (value(PARITY))[0] == '\0') {
609 		if (curpar != NULL)
610 			free(curpar);
611 		value(PARITY) = curpar = strdup(defparity);
612 	}
613 	parity = value(PARITY);
614 	if (equal(parity, "none")) {
615 		bits8 = 1;
616 		return;
617 	}
618 	bits8 = 0;
619 	flip = 0;
620 	clr = 0377;
621 	set = 0;
622 	if (equal(parity, "odd"))
623 		flip = 0200;			/* reverse bit 7 */
624 	else if (equal(parity, "zero"))
625 		clr = 0177;			/* turn off bit 7 */
626 	else if (equal(parity, "one"))
627 		set = 0200;			/* turn on bit 7 */
628 	else if (!equal(parity, "even")) {
629 		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
630 		(void) fflush(stderr);
631 	}
632 	for (i = 0; i < 0200; i++)
633 		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
634 }
635