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
45 int disc = TTYDISC; /* tip normally runs this way */
46 char PNbuf[256]; /* This limits the size of a number */
47
48 static void intprompt(int);
49 static void tipin(void);
50 static int escape(void);
51
52 int
main(int argc,char * argv[])53 main(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
126 notnumber:
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 }
188 cucommon:
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
243 void
cleanup(int signo)244 cleanup(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 */
266 static int uidswapped;
267
268 void
user_uid(void)269 user_uid(void)
270 {
271 if (uidswapped == 0) {
272 seteuid(uid);
273 uidswapped = 1;
274 }
275 }
276
277 void
daemon_uid(void)278 daemon_uid(void)
279 {
280
281 if (uidswapped) {
282 seteuid(euid);
283 uidswapped = 0;
284 }
285 }
286
287 void
shell_uid(void)288 shell_uid(void)
289 {
290 setegid(gid);
291 seteuid(uid);
292 }
293
294 /*
295 * put the controlling keyboard into raw mode
296 */
297 void
raw(void)298 raw(void)
299 {
300 tcsetattr(0, TCSADRAIN, &term);
301 }
302
303
304 /*
305 * return keyboard to normal mode
306 */
307 void
unraw(void)308 unraw(void)
309 {
310 if (gotdefterm)
311 tcsetattr(0, TCSADRAIN, &defterm);
312 }
313
314 /*
315 * give up exclusive tty access
316 */
317 void
unexcl()318 unexcl()
319 {
320 ioctl(FD, TIOCNXCL, 0);
321 }
322
323 static 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 */
330 int
prompt(char * s,char * p,size_t sz)331 prompt(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*/
357 static void
intprompt(int signo)358 intprompt(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 */
369 static void
tipin(void)370 tipin(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
427 extern esctable_t etable[];
428
429 /*
430 * Escape handler --
431 * called on recognition of ``escapec'' at the beginning of a line
432 */
433 static int
escape(void)434 escape(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
458 int
any(int cc,char * p)459 any(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
468 size_t
size(char * s)469 size(char *s)
470 {
471 size_t i = 0;
472
473 while (s && *s++)
474 i++;
475 return (i);
476 }
477
478 char *
interp(char * s)479 interp(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
503 char *
ctrl(char c)504 ctrl(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 */
522 void
help(int c)523 help(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 */
540 int
ttysetup(int speed)541 ttysetup(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
564 static 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 */
571 void
parwrite(int fd,char * buf,size_t n)572 parwrite(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 */
594 void
setparity(char * defparity)595 setparity(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