tip.c revision 331722 
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: stable/11/usr.bin/tip/tip/tip.c 331722 2018-03-29 02:50:57Z eadler $");
35
36#ifndef lint
37static const char copyright[] =
38"@(#) Copyright (c) 1983, 1993\n\
39	The Regents of the University of California.  All rights reserved.\n";
40#endif /* not lint */
41
42#ifndef lint
43#if 0
44static char sccsid[] = "@(#)tip.c	8.1 (Berkeley) 6/6/93";
45static const char rcsid[] = "$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
58int	disc = TTYDISC;		/* tip normally runs this way */
59char	PNbuf[256];			/* This limits the size of a number */
60
61static void	intprompt(int);
62static void	tipin(void);
63static int	escape(void);
64
65int
66main(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
139notnumber:
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	}
201cucommon:
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
257void
258cleanup(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 */
280static int uidswapped;
281
282void
283user_uid(void)
284{
285	if (uidswapped == 0) {
286		seteuid(uid);
287		uidswapped = 1;
288	}
289}
290
291void
292daemon_uid(void)
293{
294
295	if (uidswapped) {
296		seteuid(euid);
297		uidswapped = 0;
298	}
299}
300
301void
302shell_uid(void)
303{
304	setegid(gid);
305	seteuid(uid);
306}
307
308/*
309 * put the controlling keyboard into raw mode
310 */
311void
312raw(void)
313{
314	tcsetattr(0, TCSADRAIN, &term);
315}
316
317
318/*
319 * return keyboard to normal mode
320 */
321void
322unraw(void)
323{
324	if (gotdefterm)
325		tcsetattr(0, TCSADRAIN, &defterm);
326}
327
328/*
329 * give up exclusive tty access
330 */
331void
332unexcl()
333{
334	ioctl(FD, TIOCNXCL, 0);
335}
336
337static	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 */
344int
345prompt(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*/
371static void
372intprompt(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 */
383static void
384tipin(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
432extern esctable_t etable[];
433
434/*
435 * Escape handler --
436 *  called on recognition of ``escapec'' at the beginning of a line
437 */
438static int
439escape(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
461int
462any(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
471size_t
472size(char *s)
473{
474	size_t i = 0;
475
476	while (s && *s++)
477		i++;
478	return (i);
479}
480
481char *
482interp(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
506char *
507ctrl(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 */
525void
526help(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 */
543int
544ttysetup(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
567static 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 */
574void
575parwrite(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 */
597void
598setparity(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