xref: /freebsd/usr.bin/tip/tip/tip.c (revision f05cddf9) 
1 /*	$OpenBSD: tip.c,v 1.30 2006/08/18 03:06:18 jason Exp $	*/
2 /*	$NetBSD: tip.c,v 1.13 1997/04/20 00:03:05 mellon Exp $	*/
3 
4 /*
5  * Copyright (c) 1983, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #ifndef lint
37 static const char copyright[] =
38 "@(#) 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 static const char rcsid[] = "$OpenBSD: tip.c,v 1.30 2006/08/18 03:06:18 jason Exp $";
46 #endif
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 int	disc = TTYDISC;		/* tip normally runs this way */
59 char	PNbuf[256];			/* This limits the size of a number */
60 
61 static void	intprompt(int);
62 static void	tipin(void);
63 static int	escape(void);
64 
65 int
66 main(int argc, char *argv[])
67 {
68 	char *sys = NOSTR, sbuf[12], *p;
69 	int i;
70 
71 	/* XXX preserve previous braindamaged behavior */
72 	setboolean(value(DC), TRUE);
73 
74 	gid = getgid();
75 	egid = getegid();
76 	uid = getuid();
77 	euid = geteuid();
78 	if (equal(__progname, "cu")) {
79 		cumode = 1;
80 		cumain(argc, argv);
81 		goto cucommon;
82 	}
83 
84 	if (argc > 4) {
85 		fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
86 		exit(1);
87 	}
88 	if (!isatty(0)) {
89 		fprintf(stderr, "%s: must be interactive\n", __progname);
90 		exit(1);
91 	}
92 
93 	for (; argc > 1; argv++, argc--) {
94 		if (argv[1][0] != '-')
95 			sys = argv[1];
96 		else switch (argv[1][1]) {
97 
98 		case 'v':
99 			vflag++;
100 			break;
101 
102 		case 'n':
103 			noesc++;
104 			break;
105 
106 		case '0': case '1': case '2': case '3': case '4':
107 		case '5': case '6': case '7': case '8': case '9':
108 			BR = atoi(&argv[1][1]);
109 			break;
110 
111 		default:
112 			fprintf(stderr, "%s: %s, unknown option\n", __progname,
113 			    argv[1]);
114 			break;
115 		}
116 	}
117 
118 	if (sys == NOSTR)
119 		goto notnumber;
120 	if (isalpha(*sys))
121 		goto notnumber;
122 	/*
123 	 * System name is really a phone number...
124 	 * Copy the number then stomp on the original (in case the number
125 	 *	is private, we don't want 'ps' or 'w' to find it).
126 	 */
127 	if (strlen(sys) > sizeof PNbuf - 1) {
128 		fprintf(stderr, "%s: phone number too long (max = %d bytes)\n",
129 			__progname, (int)sizeof(PNbuf) - 1);
130 		exit(1);
131 	}
132 	strlcpy(PNbuf, sys, sizeof PNbuf - 1);
133 	for (p = sys; *p; p++)
134 		*p = '\0';
135 	PN = PNbuf;
136 	(void)snprintf(sbuf, sizeof(sbuf), "tip%ld", BR);
137 	sys = sbuf;
138 
139 notnumber:
140 	(void)signal(SIGINT, cleanup);
141 	(void)signal(SIGQUIT, cleanup);
142 	(void)signal(SIGHUP, cleanup);
143 	(void)signal(SIGTERM, cleanup);
144 	(void)signal(SIGCHLD, SIG_DFL);
145 
146 	if ((i = hunt(sys)) == 0) {
147 		printf("all ports busy\n");
148 		exit(3);
149 	}
150 	if (i == -1) {
151 		printf("link down\n");
152 		(void)uu_unlock(uucplock);
153 		exit(3);
154 	}
155 	setbuf(stdout, NULL);
156 	loginit();
157 
158 	/*
159 	 * Now that we have the logfile and the ACU open
160 	 *  return to the real uid and gid.  These things will
161 	 *  be closed on exit.  Swap real and effective uid's
162 	 *  so we can get the original permissions back
163 	 *  for removing the uucp lock.
164 	 */
165 	user_uid();
166 
167 	/*
168 	 * Kludge, their's no easy way to get the initialization
169 	 *   in the right order, so force it here
170 	 */
171 	if ((PH = getenv("PHONES")) == NOSTR)
172 		PH = _PATH_PHONES;
173 	vinit();				/* init variables */
174 	setparity("none");			/* set the parity table */
175 
176 	/*
177 	 * Hardwired connections require the
178 	 *  line speed set before they make any transmissions
179 	 *  (this is particularly true of things like a DF03-AC)
180 	 */
181 	if (HW && ttysetup(number(value(BAUDRATE)))) {
182 		fprintf(stderr, "%s: bad baud rate %ld\n", __progname,
183 		    number(value(BAUDRATE)));
184 		daemon_uid();
185 		(void)uu_unlock(uucplock);
186 		exit(3);
187 	}
188 	if ((p = con())) {
189 		printf("\07%s\n[EOT]\n", p);
190 		daemon_uid();
191 		(void)uu_unlock(uucplock);
192 		exit(1);
193 	}
194 	if (!HW && ttysetup(number(value(BAUDRATE)))) {
195 		fprintf(stderr, "%s: bad baud rate %ld\n", __progname,
196 		    number(value(BAUDRATE)));
197 		daemon_uid();
198 		(void)uu_unlock(uucplock);
199 		exit(3);
200 	}
201 cucommon:
202 	/*
203 	 * From here down the code is shared with
204 	 * the "cu" version of tip.
205 	 */
206 
207 	i = fcntl(FD, F_GETFL);
208 	if (i == -1) {
209 		perror("fcntl");
210 		cleanup(0);
211 	}
212 	i = fcntl(FD, F_SETFL, i & ~O_NONBLOCK);
213 	if (i == -1) {
214 		perror("fcntl");
215 		cleanup(0);
216 	}
217 
218 	tcgetattr(0, &defterm);
219 	gotdefterm = 1;
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, timeout);
234 
235 	if (value(LINEDISC) != TTYDISC) {
236 		int ld = (int)(intptr_t)value(LINEDISC);
237 		ioctl(FD, TIOCSETD, &ld);
238 	}
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 	tipin_pid = getpid();
249 	if ((tipout_pid = fork()))
250 		tipin();
251 	else
252 		tipout();
253 	/*NOTREACHED*/
254 	exit(0);
255 }
256 
257 void
258 cleanup(int signo)
259 {
260 	daemon_uid();
261 	(void)uu_unlock(uucplock);
262 	if (odisc)
263 		ioctl(0, TIOCSETD, &odisc);
264 	unraw();
265 	if (signo && tipout_pid) {
266 		kill(tipout_pid, signo);
267 		wait(NULL);
268 	}
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(void)
284 {
285 	if (uidswapped == 0) {
286 		seteuid(uid);
287 		uidswapped = 1;
288 	}
289 }
290 
291 void
292 daemon_uid(void)
293 {
294 
295 	if (uidswapped) {
296 		seteuid(euid);
297 		uidswapped = 0;
298 	}
299 }
300 
301 void
302 shell_uid(void)
303 {
304 	setegid(gid);
305 	seteuid(uid);
306 }
307 
308 /*
309  * put the controlling keyboard into raw mode
310  */
311 void
312 raw(void)
313 {
314 	tcsetattr(0, TCSADRAIN, &term);
315 }
316 
317 
318 /*
319  * return keyboard to normal mode
320  */
321 void
322 unraw(void)
323 {
324 	if (gotdefterm)
325 		tcsetattr(0, TCSADRAIN, &defterm);
326 }
327 
328 /*
329  * give up exclusive tty access
330  */
331 void
332 unexcl()
333 {
334 	ioctl(FD, TIOCNXCL, 0);
335 }
336 
337 static	jmp_buf promptbuf;
338 
339 /*
340  * Print string ``s'', then read a string
341  *  in from the terminal.  Handles signals & allows use of
342  *  normal erase and kill characters.
343  */
344 int
345 prompt(char *s, char *p, size_t sz)
346 {
347 	int c;
348 	char *b = p;
349 	sig_t oint, oquit;
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()) != EOF && (*p = c) != '\n' && --sz > 0)
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 /*ARGSUSED*/
371 static void
372 intprompt(int signo)
373 {
374 	(void)signal(SIGINT, SIG_IGN);
375 	stoprompt = 1;
376 	printf("\r\n");
377 	longjmp(promptbuf, 1);
378 }
379 
380 /*
381  * ****TIPIN   TIPIN****
382  */
383 static void
384 tipin(void)
385 {
386 	int bol = 1;
387 	int gch;
388 	char ch;
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 		/* XXX does not check for EOF */
405 		if ((gch == character(value(ESCAPE))) && bol) {
406 			if (!noesc) {
407 				if (!(gch = escape()))
408 					continue;
409 			}
410 		} else if (!cumode && gch == character(value(RAISECHAR))) {
411 			setboolean(value(RAISE), !boolean(value(RAISE)));
412 			continue;
413 		} else if (gch == '\r') {
414 			bol = 1;
415 			ch = gch;
416 			parwrite(FD, &ch, 1);
417 			if (boolean(value(HALFDUPLEX)))
418 				printf("\r\n");
419 			continue;
420 		} else if (!cumode && gch == character(value(FORCE)))
421 			gch = getchar()&STRIP_PAR;
422 		bol = any(gch, value(EOL));
423 		if (boolean(value(RAISE)) && islower(gch))
424 			gch = toupper(gch);
425 		ch = gch;
426 		parwrite(FD, &ch, 1);
427 		if (boolean(value(HALFDUPLEX)))
428 			printf("%c", ch);
429 	}
430 }
431 
432 extern esctable_t etable[];
433 
434 /*
435  * Escape handler --
436  *  called on recognition of ``escapec'' at the beginning of a line
437  */
438 static int
439 escape(void)
440 {
441 	int gch;
442 	esctable_t *p;
443 	char c = character(value(ESCAPE));
444 
445 	gch = (getchar()&STRIP_PAR);
446 	/* XXX does not check for EOF */
447 	for (p = etable; p->e_char; p++)
448 		if (p->e_char == gch) {
449 			if ((p->e_flags&PRIV) && uid)
450 				continue;
451 			printf("%s", ctrl(c));
452 			(*p->e_func)(gch);
453 			return (0);
454 		}
455 	/* ESCAPE ESCAPE forces ESCAPE */
456 	if (c != gch)
457 		parwrite(FD, &c, 1);
458 	return (gch);
459 }
460 
461 int
462 any(int cc, char *p)
463 {
464 	char c = cc;
465 	while (p && *p)
466 		if (*p++ == c)
467 			return (1);
468 	return (0);
469 }
470 
471 size_t
472 size(char *s)
473 {
474 	size_t i = 0;
475 
476 	while (s && *s++)
477 		i++;
478 	return (i);
479 }
480 
481 char *
482 interp(char *s)
483 {
484 	static char buf[256];
485 	char *p = buf, c, *q;
486 
487 	while ((c = *s++)) {
488 		for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
489 			if (*q++ == c) {
490 				*p++ = '\\'; *p++ = *q;
491 				goto next;
492 			}
493 		if (c < 040) {
494 			*p++ = '^'; *p++ = c + 'A'-1;
495 		} else if (c == 0177) {
496 			*p++ = '^'; *p++ = '?';
497 		} else
498 			*p++ = c;
499 	next:
500 		;
501 	}
502 	*p = '\0';
503 	return (buf);
504 }
505 
506 char *
507 ctrl(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(int 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 int
544 ttysetup(int speed)
545 {
546 	struct termios	cntrl;
547 
548 	if (tcgetattr(FD, &cntrl))
549 		return (-1);
550 	cfsetspeed(&cntrl, speed);
551 	cntrl.c_cflag &= ~(CSIZE|PARENB);
552 	cntrl.c_cflag |= CS8;
553 	if (boolean(value(DC)))
554 		cntrl.c_cflag |= CLOCAL;
555 	if (boolean(value(HARDWAREFLOW)))
556 		cntrl.c_cflag |= CRTSCTS;
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 	return (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 parwrite(int fd, char *buf, size_t n)
576 {
577 	size_t i;
578 	char *bp;
579 
580 	bp = buf;
581 	if (bits8 == 0)
582 		for (i = 0; i < n; i++) {
583 			*bp = partab[(*bp) & 0177];
584 			bp++;
585 		}
586 	if (write(fd, buf, n) < 0) {
587 		if (errno == EIO || errno == ENXIO)
588 			tipabort("Lost carrier.");
589 		/* this is questionable */
590 		perror("write");
591 	}
592 }
593 
594 /*
595  * Build a parity table with appropriate high-order bit.
596  */
597 void
598 setparity(char *defparity)
599 {
600 	int i, flip, clr, set;
601 	char *parity;
602 	extern const unsigned char evenpartab[];
603 
604 	if (value(PARITY) == NOSTR)
605 		value(PARITY) = defparity;
606 	parity = value(PARITY);
607 	if (equal(parity, "none")) {
608 		bits8 = 1;
609 		return;
610 	}
611 	bits8 = 0;
612 	flip = 0;
613 	clr = 0377;
614 	set = 0;
615 	if (equal(parity, "odd"))
616 		flip = 0200;			/* reverse bit 7 */
617 	else if (equal(parity, "zero"))
618 		clr = 0177;			/* turn off bit 7 */
619 	else if (equal(parity, "one"))
620 		set = 0200;			/* turn on bit 7 */
621 	else if (!equal(parity, "even")) {
622 		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
623 		(void) fflush(stderr);
624 	}
625 	for (i = 0; i < 0200; i++)
626 		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
627 }
628