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 * SPDX-License-Identifier: BSD-3-Clause
6 *
7 * Copyright (c) 1983, 1993
8 *	The Regents of the University of California.  All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35/*
36 * tip - UNIX link to other systems
37 *  tip [-v] [-speed] system-name
38 * or
39 *  cu phone-number [-s speed] [-l line] [-a acu]
40 */
41#define	EXTERN
42#include "tip.h"
43#include "pathnames.h"
44
45int	disc = TTYDISC;		/* tip normally runs this way */
46char	PNbuf[256];			/* This limits the size of a number */
47
48static void	intprompt(int);
49static void	tipin(void);
50static int	escape(void);
51
52int
53main(int argc, char *argv[])
54{
55	char *sys = NOSTR, sbuf[12], *p;
56	int i;
57
58	/* XXX preserve previous braindamaged behavior */
59	setboolean(value(DC), TRUE);
60
61	gid = getgid();
62	egid = getegid();
63	uid = getuid();
64	euid = geteuid();
65	if (equal(__progname, "cu")) {
66		cumode = 1;
67		cumain(argc, argv);
68		goto cucommon;
69	}
70
71	if (argc > 4) {
72		fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
73		exit(1);
74	}
75	if (!isatty(0)) {
76		fprintf(stderr, "%s: must be interactive\n", __progname);
77		exit(1);
78	}
79
80	for (; argc > 1; argv++, argc--) {
81		if (argv[1][0] != '-')
82			sys = argv[1];
83		else switch (argv[1][1]) {
84
85		case 'v':
86			vflag++;
87			break;
88
89		case 'n':
90			noesc++;
91			break;
92
93		case '0': case '1': case '2': case '3': case '4':
94		case '5': case '6': case '7': case '8': case '9':
95			BR = atoi(&argv[1][1]);
96			break;
97
98		default:
99			fprintf(stderr, "%s: %s, unknown option\n", __progname,
100			    argv[1]);
101			break;
102		}
103	}
104
105	if (sys == NOSTR)
106		goto notnumber;
107	if (isalpha(*sys))
108		goto notnumber;
109	/*
110	 * System name is really a phone number...
111	 * Copy the number then stomp on the original (in case the number
112	 *	is private, we don't want 'ps' or 'w' to find it).
113	 */
114	if (strlen(sys) > sizeof PNbuf - 1) {
115		fprintf(stderr, "%s: phone number too long (max = %d bytes)\n",
116			__progname, (int)sizeof(PNbuf) - 1);
117		exit(1);
118	}
119	strlcpy(PNbuf, sys, sizeof PNbuf - 1);
120	for (p = sys; *p; p++)
121		*p = '\0';
122	PN = PNbuf;
123	(void)snprintf(sbuf, sizeof(sbuf), "tip%ld", BR);
124	sys = sbuf;
125
126notnumber:
127	(void)signal(SIGINT, cleanup);
128	(void)signal(SIGQUIT, cleanup);
129	(void)signal(SIGHUP, cleanup);
130	(void)signal(SIGTERM, cleanup);
131	(void)signal(SIGCHLD, SIG_DFL);
132
133	if ((i = hunt(sys)) == 0) {
134		printf("all ports busy\n");
135		exit(3);
136	}
137	if (i == -1) {
138		printf("link down\n");
139		(void)uu_unlock(uucplock);
140		exit(3);
141	}
142	setbuf(stdout, NULL);
143	loginit();
144
145	/*
146	 * Now that we have the logfile and the ACU open
147	 *  return to the real uid and gid.  These things will
148	 *  be closed on exit.  Swap real and effective uid's
149	 *  so we can get the original permissions back
150	 *  for removing the uucp lock.
151	 */
152	user_uid();
153
154	/*
155	 * Kludge, their's no easy way to get the initialization
156	 *   in the right order, so force it here
157	 */
158	if ((PH = getenv("PHONES")) == NOSTR)
159		PH = _PATH_PHONES;
160	vinit();				/* init variables */
161	setparity("none");			/* set the parity table */
162
163	/*
164	 * Hardwired connections require the
165	 *  line speed set before they make any transmissions
166	 *  (this is particularly true of things like a DF03-AC)
167	 */
168	if (HW && ttysetup(number(value(BAUDRATE)))) {
169		fprintf(stderr, "%s: bad baud rate %ld\n", __progname,
170		    number(value(BAUDRATE)));
171		daemon_uid();
172		(void)uu_unlock(uucplock);
173		exit(3);
174	}
175	if ((p = con())) {
176		printf("\07%s\n[EOT]\n", p);
177		daemon_uid();
178		(void)uu_unlock(uucplock);
179		exit(1);
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	}
188cucommon:
189	/*
190	 * From here down the code is shared with
191	 * the "cu" version of tip.
192	 */
193
194	i = fcntl(FD, F_GETFL);
195	if (i == -1) {
196		perror("fcntl");
197		cleanup(0);
198	}
199	i = fcntl(FD, F_SETFL, i & ~O_NONBLOCK);
200	if (i == -1) {
201		perror("fcntl");
202		cleanup(0);
203	}
204
205	tcgetattr(0, &defterm);
206	gotdefterm = 1;
207	term = defterm;
208	term.c_lflag &= ~(ICANON|IEXTEN|ECHO);
209	term.c_iflag &= ~(INPCK|ICRNL);
210	term.c_oflag &= ~OPOST;
211	term.c_cc[VMIN] = 1;
212	term.c_cc[VTIME] = 0;
213	defchars = term;
214	term.c_cc[VINTR] = term.c_cc[VQUIT] = term.c_cc[VSUSP] =
215	    term.c_cc[VDSUSP] = term.c_cc[VDISCARD] =
216	    term.c_cc[VLNEXT] = _POSIX_VDISABLE;
217	raw();
218
219	pipe(fildes); pipe(repdes);
220	(void)signal(SIGALRM, timeout);
221
222	if (value(LINEDISC) != TTYDISC) {
223		int ld = (int)(intptr_t)value(LINEDISC);
224		ioctl(FD, TIOCSETD, &ld);
225	}
226
227	/*
228	 * Everything's set up now:
229	 *	connection established (hardwired or dialup)
230	 *	line conditioned (baud rate, mode, etc.)
231	 *	internal data structures (variables)
232	 * so, fork one process for local side and one for remote.
233	 */
234	printf(cumode ? "Connected\r\n" : "\07connected\r\n");
235	tipin_pid = getpid();
236	if ((tipout_pid = fork()))
237		tipin();
238	else
239		tipout();
240	exit(0);
241}
242
243void
244cleanup(int signo)
245{
246	daemon_uid();
247	(void)uu_unlock(uucplock);
248	if (odisc)
249		ioctl(0, TIOCSETD, &odisc);
250	unraw();
251	if (signo && tipout_pid) {
252		kill(tipout_pid, signo);
253		wait(NULL);
254	}
255	exit(0);
256}
257
258/*
259 * Muck with user ID's.  We are setuid to the owner of the lock
260 * directory when we start.  user_uid() reverses real and effective
261 * ID's after startup, to run with the user's permissions.
262 * daemon_uid() switches back to the privileged uid for unlocking.
263 * Finally, to avoid running a shell with the wrong real uid,
264 * shell_uid() sets real and effective uid's to the user's real ID.
265 */
266static int uidswapped;
267
268void
269user_uid(void)
270{
271	if (uidswapped == 0) {
272		seteuid(uid);
273		uidswapped = 1;
274	}
275}
276
277void
278daemon_uid(void)
279{
280
281	if (uidswapped) {
282		seteuid(euid);
283		uidswapped = 0;
284	}
285}
286
287void
288shell_uid(void)
289{
290	setegid(gid);
291	seteuid(uid);
292}
293
294/*
295 * put the controlling keyboard into raw mode
296 */
297void
298raw(void)
299{
300	tcsetattr(0, TCSADRAIN, &term);
301}
302
303
304/*
305 * return keyboard to normal mode
306 */
307void
308unraw(void)
309{
310	if (gotdefterm)
311		tcsetattr(0, TCSADRAIN, &defterm);
312}
313
314/*
315 * give up exclusive tty access
316 */
317void
318unexcl()
319{
320	ioctl(FD, TIOCNXCL, 0);
321}
322
323static	jmp_buf promptbuf;
324
325/*
326 * Print string ``s'', then read a string
327 *  in from the terminal.  Handles signals & allows use of
328 *  normal erase and kill characters.
329 */
330int
331prompt(char *s, char *p, size_t sz)
332{
333	int c;
334	char *b = p;
335	sig_t oint, oquit;
336
337	stoprompt = 0;
338	oint = signal(SIGINT, intprompt);
339	oquit = signal(SIGQUIT, SIG_IGN);
340	unraw();
341	printf("%s", s);
342	if (setjmp(promptbuf) == 0)
343		while ((c = getchar()) != EOF && (*p = c) != '\n' && --sz > 0)
344			p++;
345	*p = '\0';
346
347	raw();
348	(void)signal(SIGINT, oint);
349	(void)signal(SIGQUIT, oquit);
350	return (stoprompt || p == b);
351}
352
353/*
354 * Interrupt service routine during prompting
355 */
356/*ARGSUSED*/
357static void
358intprompt(int signo)
359{
360	(void)signal(SIGINT, SIG_IGN);
361	stoprompt = 1;
362	printf("\r\n");
363	longjmp(promptbuf, 1);
364}
365
366/*
367 * ****TIPIN   TIPIN****
368 */
369static void
370tipin(void)
371{
372	int bol = 1;
373	int gch;
374	char ch;
375
376	/*
377	 * Kinda klugey here...
378	 *   check for scripting being turned on from the .tiprc file,
379	 *   but be careful about just using setscript(), as we may
380	 *   send a SIGEMT before tipout has a chance to set up catching
381	 *   it; so wait a second, then setscript()
382	 */
383	if (boolean(value(SCRIPT))) {
384		sleep(1);
385		setscript();
386	}
387
388	while (1) {
389		gch = getchar();
390		if (gch == EOF)
391			return;
392		gch = gch & STRIP_PAR;
393		if ((gch == character(value(ESCAPE))) && bol) {
394			if (!noesc) {
395				gch = escape();
396				if (gch == EOF)
397					return;
398				if (gch == 0)
399					continue;
400			}
401		} else if (!cumode && gch == character(value(RAISECHAR))) {
402			setboolean(value(RAISE), !boolean(value(RAISE)));
403			continue;
404		} else if (gch == '\r') {
405			bol = 1;
406			ch = gch;
407			parwrite(FD, &ch, 1);
408			if (boolean(value(HALFDUPLEX)))
409				printf("\r\n");
410			continue;
411		} else if (!cumode && gch == character(value(FORCE))) {
412			gch = getchar();
413			if (gch == EOF)
414				return;
415			gch = gch & STRIP_PAR;
416		}
417		bol = any(gch, value(EOL));
418		if (boolean(value(RAISE)) && islower(gch))
419			gch = toupper(gch);
420		ch = gch;
421		parwrite(FD, &ch, 1);
422		if (boolean(value(HALFDUPLEX)))
423			printf("%c", ch);
424	}
425}
426
427extern esctable_t etable[];
428
429/*
430 * Escape handler --
431 *  called on recognition of ``escapec'' at the beginning of a line
432 */
433static int
434escape(void)
435{
436	int gch;
437	esctable_t *p;
438	char c = character(value(ESCAPE));
439
440	gch = getchar();
441	if (gch == EOF)
442		return (EOF);
443	gch = gch & STRIP_PAR;
444	for (p = etable; p->e_char; p++)
445		if (p->e_char == gch) {
446			if ((p->e_flags&PRIV) && uid)
447				continue;
448			printf("%s", ctrl(c));
449			(*p->e_func)(gch);
450			return (0);
451		}
452	/* ESCAPE ESCAPE forces ESCAPE */
453	if (c != gch)
454		parwrite(FD, &c, 1);
455	return (gch);
456}
457
458int
459any(int cc, char *p)
460{
461	char c = cc;
462	while (p && *p)
463		if (*p++ == c)
464			return (1);
465	return (0);
466}
467
468size_t
469size(char *s)
470{
471	size_t i = 0;
472
473	while (s && *s++)
474		i++;
475	return (i);
476}
477
478char *
479interp(char *s)
480{
481	static char buf[256];
482	char *p = buf, c, *q;
483
484	while ((c = *s++)) {
485		for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
486			if (*q++ == c) {
487				*p++ = '\\'; *p++ = *q;
488				goto next;
489			}
490		if (c < 040) {
491			*p++ = '^'; *p++ = c + 'A'-1;
492		} else if (c == 0177) {
493			*p++ = '^'; *p++ = '?';
494		} else
495			*p++ = c;
496	next:
497		;
498	}
499	*p = '\0';
500	return (buf);
501}
502
503char *
504ctrl(char c)
505{
506	static char s[3];
507
508	if (c < 040 || c == 0177) {
509		s[0] = '^';
510		s[1] = c == 0177 ? '?' : c+'A'-1;
511		s[2] = '\0';
512	} else {
513		s[0] = c;
514		s[1] = '\0';
515	}
516	return (s);
517}
518
519/*
520 * Help command
521 */
522void
523help(int c)
524{
525	esctable_t *p;
526
527	printf("%c\r\n", c);
528	for (p = etable; p->e_char; p++) {
529		if ((p->e_flags&PRIV) && uid)
530			continue;
531		printf("%2s", ctrl(character(value(ESCAPE))));
532		printf("%-2s %c   %s\r\n", ctrl(p->e_char),
533			p->e_flags&EXP ? '*': ' ', p->e_help);
534	}
535}
536
537/*
538 * Set up the "remote" tty's state
539 */
540int
541ttysetup(int speed)
542{
543	struct termios	cntrl;
544
545	if (tcgetattr(FD, &cntrl))
546		return (-1);
547	cfsetspeed(&cntrl, speed);
548	cntrl.c_cflag &= ~(CSIZE|PARENB);
549	cntrl.c_cflag |= CS8;
550	if (boolean(value(DC)))
551		cntrl.c_cflag |= CLOCAL;
552	if (boolean(value(HARDWAREFLOW)))
553		cntrl.c_cflag |= CRTSCTS;
554	cntrl.c_iflag &= ~(ISTRIP|ICRNL);
555	cntrl.c_oflag &= ~OPOST;
556	cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
557	cntrl.c_cc[VMIN] = 1;
558	cntrl.c_cc[VTIME] = 0;
559	if (boolean(value(TAND)))
560		cntrl.c_iflag |= IXOFF;
561	return (tcsetattr(FD, TCSAFLUSH, &cntrl));
562}
563
564static char partab[0200];
565
566/*
567 * Do a write to the remote machine with the correct parity.
568 * We are doing 8 bit wide output, so we just generate a character
569 * with the right parity and output it.
570 */
571void
572parwrite(int fd, char *buf, size_t n)
573{
574	size_t i;
575	char *bp;
576
577	bp = buf;
578	if (bits8 == 0)
579		for (i = 0; i < n; i++) {
580			*bp = partab[(*bp) & 0177];
581			bp++;
582		}
583	if (write(fd, buf, n) < 0) {
584		if (errno == EIO || errno == ENXIO)
585			tipabort("Lost carrier.");
586		/* this is questionable */
587		perror("write");
588	}
589}
590
591/*
592 * Build a parity table with appropriate high-order bit.
593 */
594void
595setparity(char *defparity)
596{
597	int i, flip, clr, set;
598	char *parity;
599	extern const unsigned char evenpartab[];
600
601	if (value(PARITY) == NOSTR)
602		value(PARITY) = defparity;
603	parity = value(PARITY);
604	if (equal(parity, "none")) {
605		bits8 = 1;
606		return;
607	}
608	bits8 = 0;
609	flip = 0;
610	clr = 0377;
611	set = 0;
612	if (equal(parity, "odd"))
613		flip = 0200;			/* reverse bit 7 */
614	else if (equal(parity, "zero"))
615		clr = 0177;			/* turn off bit 7 */
616	else if (equal(parity, "one"))
617		set = 0200;			/* turn on bit 7 */
618	else if (!equal(parity, "even")) {
619		(void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
620		(void) fflush(stderr);
621	}
622	for (i = 0; i < 0200; i++)
623		partab[i] = ((evenpartab[i] ^ flip) | set) & clr;
624}
625