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 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #ifndef lint 39 static const char copyright[] = 40 "@(#) Copyright (c) 1983, 1993\n\ 41 The Regents of the University of California. All rights reserved.\n"; 42 #endif /* not lint */ 43 44 #ifndef lint 45 #if 0 46 static char sccsid[] = "@(#)tip.c 8.1 (Berkeley) 6/6/93"; 47 static const char rcsid[] = "$OpenBSD: tip.c,v 1.30 2006/08/18 03:06:18 jason Exp $"; 48 #endif 49 #endif /* not lint */ 50 51 /* 52 * tip - UNIX link to other systems 53 * tip [-v] [-speed] system-name 54 * or 55 * cu phone-number [-s speed] [-l line] [-a acu] 56 */ 57 #define EXTERN 58 #include "tip.h" 59 #include "pathnames.h" 60 61 int disc = TTYDISC; /* tip normally runs this way */ 62 char PNbuf[256]; /* This limits the size of a number */ 63 64 static void intprompt(int); 65 static void tipin(void); 66 static int escape(void); 67 68 int 69 main(int argc, char *argv[]) 70 { 71 char *sys = NOSTR, sbuf[12], *p; 72 int i; 73 74 /* XXX preserve previous braindamaged behavior */ 75 setboolean(value(DC), TRUE); 76 77 gid = getgid(); 78 egid = getegid(); 79 uid = getuid(); 80 euid = geteuid(); 81 if (equal(__progname, "cu")) { 82 cumode = 1; 83 cumain(argc, argv); 84 goto cucommon; 85 } 86 87 if (argc > 4) { 88 fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n"); 89 exit(1); 90 } 91 if (!isatty(0)) { 92 fprintf(stderr, "%s: must be interactive\n", __progname); 93 exit(1); 94 } 95 96 for (; argc > 1; argv++, argc--) { 97 if (argv[1][0] != '-') 98 sys = argv[1]; 99 else switch (argv[1][1]) { 100 101 case 'v': 102 vflag++; 103 break; 104 105 case 'n': 106 noesc++; 107 break; 108 109 case '0': case '1': case '2': case '3': case '4': 110 case '5': case '6': case '7': case '8': case '9': 111 BR = atoi(&argv[1][1]); 112 break; 113 114 default: 115 fprintf(stderr, "%s: %s, unknown option\n", __progname, 116 argv[1]); 117 break; 118 } 119 } 120 121 if (sys == NOSTR) 122 goto notnumber; 123 if (isalpha(*sys)) 124 goto notnumber; 125 /* 126 * System name is really a phone number... 127 * Copy the number then stomp on the original (in case the number 128 * is private, we don't want 'ps' or 'w' to find it). 129 */ 130 if (strlen(sys) > sizeof PNbuf - 1) { 131 fprintf(stderr, "%s: phone number too long (max = %d bytes)\n", 132 __progname, (int)sizeof(PNbuf) - 1); 133 exit(1); 134 } 135 strlcpy(PNbuf, sys, sizeof PNbuf - 1); 136 for (p = sys; *p; p++) 137 *p = '\0'; 138 PN = PNbuf; 139 (void)snprintf(sbuf, sizeof(sbuf), "tip%ld", BR); 140 sys = sbuf; 141 142 notnumber: 143 (void)signal(SIGINT, cleanup); 144 (void)signal(SIGQUIT, cleanup); 145 (void)signal(SIGHUP, cleanup); 146 (void)signal(SIGTERM, cleanup); 147 (void)signal(SIGCHLD, SIG_DFL); 148 149 if ((i = hunt(sys)) == 0) { 150 printf("all ports busy\n"); 151 exit(3); 152 } 153 if (i == -1) { 154 printf("link down\n"); 155 (void)uu_unlock(uucplock); 156 exit(3); 157 } 158 setbuf(stdout, NULL); 159 loginit(); 160 161 /* 162 * Now that we have the logfile and the ACU open 163 * return to the real uid and gid. These things will 164 * be closed on exit. Swap real and effective uid's 165 * so we can get the original permissions back 166 * for removing the uucp lock. 167 */ 168 user_uid(); 169 170 /* 171 * Kludge, their's no easy way to get the initialization 172 * in the right order, so force it here 173 */ 174 if ((PH = getenv("PHONES")) == NOSTR) 175 PH = _PATH_PHONES; 176 vinit(); /* init variables */ 177 setparity("none"); /* set the parity table */ 178 179 /* 180 * Hardwired connections require the 181 * line speed set before they make any transmissions 182 * (this is particularly true of things like a DF03-AC) 183 */ 184 if (HW && ttysetup(number(value(BAUDRATE)))) { 185 fprintf(stderr, "%s: bad baud rate %ld\n", __progname, 186 number(value(BAUDRATE))); 187 daemon_uid(); 188 (void)uu_unlock(uucplock); 189 exit(3); 190 } 191 if ((p = con())) { 192 printf("\07%s\n[EOT]\n", p); 193 daemon_uid(); 194 (void)uu_unlock(uucplock); 195 exit(1); 196 } 197 if (!HW && ttysetup(number(value(BAUDRATE)))) { 198 fprintf(stderr, "%s: bad baud rate %ld\n", __progname, 199 number(value(BAUDRATE))); 200 daemon_uid(); 201 (void)uu_unlock(uucplock); 202 exit(3); 203 } 204 cucommon: 205 /* 206 * From here down the code is shared with 207 * the "cu" version of tip. 208 */ 209 210 i = fcntl(FD, F_GETFL); 211 if (i == -1) { 212 perror("fcntl"); 213 cleanup(0); 214 } 215 i = fcntl(FD, F_SETFL, i & ~O_NONBLOCK); 216 if (i == -1) { 217 perror("fcntl"); 218 cleanup(0); 219 } 220 221 tcgetattr(0, &defterm); 222 gotdefterm = 1; 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, timeout); 237 238 if (value(LINEDISC) != TTYDISC) { 239 int ld = (int)(intptr_t)value(LINEDISC); 240 ioctl(FD, TIOCSETD, &ld); 241 } 242 243 /* 244 * Everything's set up now: 245 * connection established (hardwired or dialup) 246 * line conditioned (baud rate, mode, etc.) 247 * internal data structures (variables) 248 * so, fork one process for local side and one for remote. 249 */ 250 printf(cumode ? "Connected\r\n" : "\07connected\r\n"); 251 tipin_pid = getpid(); 252 if ((tipout_pid = fork())) 253 tipin(); 254 else 255 tipout(); 256 exit(0); 257 } 258 259 void 260 cleanup(int signo) 261 { 262 daemon_uid(); 263 (void)uu_unlock(uucplock); 264 if (odisc) 265 ioctl(0, TIOCSETD, &odisc); 266 unraw(); 267 if (signo && tipout_pid) { 268 kill(tipout_pid, signo); 269 wait(NULL); 270 } 271 exit(0); 272 } 273 274 /* 275 * Muck with user ID's. We are setuid to the owner of the lock 276 * directory when we start. user_uid() reverses real and effective 277 * ID's after startup, to run with the user's permissions. 278 * daemon_uid() switches back to the privileged uid for unlocking. 279 * Finally, to avoid running a shell with the wrong real uid, 280 * shell_uid() sets real and effective uid's to the user's real ID. 281 */ 282 static int uidswapped; 283 284 void 285 user_uid(void) 286 { 287 if (uidswapped == 0) { 288 seteuid(uid); 289 uidswapped = 1; 290 } 291 } 292 293 void 294 daemon_uid(void) 295 { 296 297 if (uidswapped) { 298 seteuid(euid); 299 uidswapped = 0; 300 } 301 } 302 303 void 304 shell_uid(void) 305 { 306 setegid(gid); 307 seteuid(uid); 308 } 309 310 /* 311 * put the controlling keyboard into raw mode 312 */ 313 void 314 raw(void) 315 { 316 tcsetattr(0, TCSADRAIN, &term); 317 } 318 319 320 /* 321 * return keyboard to normal mode 322 */ 323 void 324 unraw(void) 325 { 326 if (gotdefterm) 327 tcsetattr(0, TCSADRAIN, &defterm); 328 } 329 330 /* 331 * give up exclusive tty access 332 */ 333 void 334 unexcl() 335 { 336 ioctl(FD, TIOCNXCL, 0); 337 } 338 339 static jmp_buf promptbuf; 340 341 /* 342 * Print string ``s'', then read a string 343 * in from the terminal. Handles signals & allows use of 344 * normal erase and kill characters. 345 */ 346 int 347 prompt(char *s, char *p, size_t sz) 348 { 349 int c; 350 char *b = p; 351 sig_t oint, oquit; 352 353 stoprompt = 0; 354 oint = signal(SIGINT, intprompt); 355 oquit = signal(SIGQUIT, SIG_IGN); 356 unraw(); 357 printf("%s", s); 358 if (setjmp(promptbuf) == 0) 359 while ((c = getchar()) != EOF && (*p = c) != '\n' && --sz > 0) 360 p++; 361 *p = '\0'; 362 363 raw(); 364 (void)signal(SIGINT, oint); 365 (void)signal(SIGQUIT, oquit); 366 return (stoprompt || p == b); 367 } 368 369 /* 370 * Interrupt service routine during prompting 371 */ 372 /*ARGSUSED*/ 373 static void 374 intprompt(int signo) 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 static void 386 tipin(void) 387 { 388 int bol = 1; 389 int gch; 390 char ch; 391 392 /* 393 * Kinda klugey here... 394 * check for scripting being turned on from the .tiprc file, 395 * but be careful about just using setscript(), as we may 396 * send a SIGEMT before tipout has a chance to set up catching 397 * it; so wait a second, then setscript() 398 */ 399 if (boolean(value(SCRIPT))) { 400 sleep(1); 401 setscript(); 402 } 403 404 while (1) { 405 gch = getchar(); 406 if (gch == EOF) 407 return; 408 gch = gch & STRIP_PAR; 409 if ((gch == character(value(ESCAPE))) && bol) { 410 if (!noesc) { 411 gch = escape(); 412 if (gch == EOF) 413 return; 414 if (gch == 0) 415 continue; 416 } 417 } else if (!cumode && gch == character(value(RAISECHAR))) { 418 setboolean(value(RAISE), !boolean(value(RAISE))); 419 continue; 420 } else if (gch == '\r') { 421 bol = 1; 422 ch = gch; 423 parwrite(FD, &ch, 1); 424 if (boolean(value(HALFDUPLEX))) 425 printf("\r\n"); 426 continue; 427 } else if (!cumode && gch == character(value(FORCE))) { 428 gch = getchar(); 429 if (gch == EOF) 430 return; 431 gch = gch & STRIP_PAR; 432 } 433 bol = any(gch, value(EOL)); 434 if (boolean(value(RAISE)) && islower(gch)) 435 gch = toupper(gch); 436 ch = gch; 437 parwrite(FD, &ch, 1); 438 if (boolean(value(HALFDUPLEX))) 439 printf("%c", ch); 440 } 441 } 442 443 extern esctable_t etable[]; 444 445 /* 446 * Escape handler -- 447 * called on recognition of ``escapec'' at the beginning of a line 448 */ 449 static int 450 escape(void) 451 { 452 int gch; 453 esctable_t *p; 454 char c = character(value(ESCAPE)); 455 456 gch = getchar(); 457 if (gch == EOF) 458 return (EOF); 459 gch = gch & STRIP_PAR; 460 for (p = etable; p->e_char; p++) 461 if (p->e_char == gch) { 462 if ((p->e_flags&PRIV) && uid) 463 continue; 464 printf("%s", ctrl(c)); 465 (*p->e_func)(gch); 466 return (0); 467 } 468 /* ESCAPE ESCAPE forces ESCAPE */ 469 if (c != gch) 470 parwrite(FD, &c, 1); 471 return (gch); 472 } 473 474 int 475 any(int cc, char *p) 476 { 477 char c = cc; 478 while (p && *p) 479 if (*p++ == c) 480 return (1); 481 return (0); 482 } 483 484 size_t 485 size(char *s) 486 { 487 size_t i = 0; 488 489 while (s && *s++) 490 i++; 491 return (i); 492 } 493 494 char * 495 interp(char *s) 496 { 497 static char buf[256]; 498 char *p = buf, c, *q; 499 500 while ((c = *s++)) { 501 for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++) 502 if (*q++ == c) { 503 *p++ = '\\'; *p++ = *q; 504 goto next; 505 } 506 if (c < 040) { 507 *p++ = '^'; *p++ = c + 'A'-1; 508 } else if (c == 0177) { 509 *p++ = '^'; *p++ = '?'; 510 } else 511 *p++ = c; 512 next: 513 ; 514 } 515 *p = '\0'; 516 return (buf); 517 } 518 519 char * 520 ctrl(char c) 521 { 522 static char s[3]; 523 524 if (c < 040 || c == 0177) { 525 s[0] = '^'; 526 s[1] = c == 0177 ? '?' : c+'A'-1; 527 s[2] = '\0'; 528 } else { 529 s[0] = c; 530 s[1] = '\0'; 531 } 532 return (s); 533 } 534 535 /* 536 * Help command 537 */ 538 void 539 help(int c) 540 { 541 esctable_t *p; 542 543 printf("%c\r\n", c); 544 for (p = etable; p->e_char; p++) { 545 if ((p->e_flags&PRIV) && uid) 546 continue; 547 printf("%2s", ctrl(character(value(ESCAPE)))); 548 printf("%-2s %c %s\r\n", ctrl(p->e_char), 549 p->e_flags&EXP ? '*': ' ', p->e_help); 550 } 551 } 552 553 /* 554 * Set up the "remote" tty's state 555 */ 556 int 557 ttysetup(int speed) 558 { 559 struct termios cntrl; 560 561 if (tcgetattr(FD, &cntrl)) 562 return (-1); 563 cfsetspeed(&cntrl, speed); 564 cntrl.c_cflag &= ~(CSIZE|PARENB); 565 cntrl.c_cflag |= CS8; 566 if (boolean(value(DC))) 567 cntrl.c_cflag |= CLOCAL; 568 if (boolean(value(HARDWAREFLOW))) 569 cntrl.c_cflag |= CRTSCTS; 570 cntrl.c_iflag &= ~(ISTRIP|ICRNL); 571 cntrl.c_oflag &= ~OPOST; 572 cntrl.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO); 573 cntrl.c_cc[VMIN] = 1; 574 cntrl.c_cc[VTIME] = 0; 575 if (boolean(value(TAND))) 576 cntrl.c_iflag |= IXOFF; 577 return (tcsetattr(FD, TCSAFLUSH, &cntrl)); 578 } 579 580 static char partab[0200]; 581 582 /* 583 * Do a write to the remote machine with the correct parity. 584 * We are doing 8 bit wide output, so we just generate a character 585 * with the right parity and output it. 586 */ 587 void 588 parwrite(int fd, char *buf, size_t n) 589 { 590 size_t i; 591 char *bp; 592 593 bp = buf; 594 if (bits8 == 0) 595 for (i = 0; i < n; i++) { 596 *bp = partab[(*bp) & 0177]; 597 bp++; 598 } 599 if (write(fd, buf, n) < 0) { 600 if (errno == EIO || errno == ENXIO) 601 tipabort("Lost carrier."); 602 /* this is questionable */ 603 perror("write"); 604 } 605 } 606 607 /* 608 * Build a parity table with appropriate high-order bit. 609 */ 610 void 611 setparity(char *defparity) 612 { 613 int i, flip, clr, set; 614 char *parity; 615 extern const unsigned char evenpartab[]; 616 617 if (value(PARITY) == NOSTR) 618 value(PARITY) = defparity; 619 parity = value(PARITY); 620 if (equal(parity, "none")) { 621 bits8 = 1; 622 return; 623 } 624 bits8 = 0; 625 flip = 0; 626 clr = 0377; 627 set = 0; 628 if (equal(parity, "odd")) 629 flip = 0200; /* reverse bit 7 */ 630 else if (equal(parity, "zero")) 631 clr = 0177; /* turn off bit 7 */ 632 else if (equal(parity, "one")) 633 set = 0200; /* turn on bit 7 */ 634 else if (!equal(parity, "even")) { 635 (void) fprintf(stderr, "%s: unknown parity value\r\n", parity); 636 (void) fflush(stderr); 637 } 638 for (i = 0; i < 0200; i++) 639 partab[i] = ((evenpartab[i] ^ flip) | set) & clr; 640 } 641