usr.bin/tip/tip.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)tip.c    8.1 (Berkeley) 6/6/93
  35  * $FreeBSD: src/usr.bin/tip/tip/tip.c,v 1.12.2.2 2001/06/02 08:08:24 phk Exp $
  36  */
  37
  38 /*
  39         Forward declarations
  40 */
  41 void ttysetup (int speed);
  42
  43 /*
  44  * tip - UNIX link to other systems
  45  *  tip [-v] [-speed] system-name
  46  * or
  47  *  cu phone-number [-s speed] [-l line] [-a acu]
  48  */
  49
  50 #include <err.h>
  51 #include <errno.h>
  52 #include <sys/types.h>
  53 #include <libutil.h>
  54 #include "tipconf.h"
  55 #include "tip.h"
  56 #include "pathnames.h"
  57
  58 /*
  59  * Baud rate mapping table
  60  */
  61 #if !HAVE_TERMIOS
  62 CONST int bauds[] = {
  63         0, 50, 75, 110, 134, 150, 200, 300, 600,
  64         1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, -1
  65 };
  66 #endif
  67
  68 #if !HAVE_TERMIOS
  69 int     disc = OTTYDISC;                /* tip normally runs this way */
  70 #endif
  71
  72 static void     intprompt(int);
  73 static void     killchild(void);
  74 static void     tipdone(int);
  75 static char     *sname(char *);
  76 char    PNbuf[256];                     /* This limits the size of a number */
  77
  78 static void usage(void);
  79 void setparity(char *);
  80 void xpwrite(int, char *, int);
  81 char escape(void);
  82 void tipin(void);
  83 int prompt(char *, char *, size_t);
  84 void unraw(void);
  85 void shell_uid(void);
  86 void daemon_uid(void);
  87 void user_uid(void);
  88
  89 int
  90 main(int argc, char *argv[])
  91 {
  92         char *system = NULL;
  93         int i;
  94         char *p;
  95         char sbuf[12];
  96
  97         gid = getgid();
  98         egid = getegid();
  99         uid = getuid();
 100         euid = geteuid();
 101
 102 #if INCLUDE_CU_INTERFACE
 103         if (equal(sname(argv[0]), "cu")) {
 104                 cumode = 1;
 105                 cumain(argc, argv);
 106                 goto cucommon;
 107         }
 108 #endif /* INCLUDE_CU_INTERFACE */
 109
 110         if (argc > 4)
 111                 usage();
 112         if (!isatty(0))
 113                 errx(1, "must be interactive");
 114
 115         for (; argc > 1; argv++, argc--) {
 116                 if (argv[1][0] != '-')
 117                         system = argv[1];
 118                 else switch (argv[1][1]) {
 119
 120                 case 'v':
 121                         vflag++;
 122                         break;
 123
 124                 case '0': case '1': case '2': case '3': case '4':
 125                 case '5': case '6': case '7': case '8': case '9':
 126                         BR = atoi(&argv[1][1]);
 127                         break;
 128
 129                 default:
 130                         warnx("%s, unknown option", argv[1]);
 131                         break;
 132                 }
 133         }
 134
 135         if (system == NULL)
 136                 goto notnumber;
 137         if (isalpha(*system))
 138                 goto notnumber;
 139         /*
 140          * System name is really a phone number...
 141          * Copy the number then stomp on the original (in case the number
 142          *      is private, we don't want 'ps' or 'w' to find it).
 143          */
 144         if (strlen(system) > sizeof(PNbuf) - 1)
 145                 errx(1, "phone number too long (max = %zd bytes)", sizeof PNbuf - 1);
 146         strncpy(PNbuf, system, sizeof(PNbuf) - 1);
 147         for (p = system; *p; p++)
 148                 *p = '\0';
 149         PN = PNbuf;
 150         (void)snprintf(sbuf, sizeof(sbuf), "tip%ld", BR);
 151         system = sbuf;
 152
 153 notnumber:
 154         (void)signal(SIGINT, cleanup);
 155         (void)signal(SIGQUIT, cleanup);
 156         (void)signal(SIGHUP, cleanup);
 157         (void)signal(SIGTERM, cleanup);
 158         (void)signal(SIGUSR1, tipdone);
 159
 160         if ((i = hunt(system)) == 0) {
 161                 printf("all ports busy\n");
 162                 exit(3);
 163         }
 164         if (i == -1) {
 165                 printf("link down\n");
 166                 (void)uu_unlock(uucplock);
 167                 exit(3);
 168         }
 169         setbuf(stdout, NULL);
 170         loginit();
 171
 172         /*
 173          * Kludge, their's no easy way to get the initialization
 174          *   in the right order, so force it here
 175          */
 176         if ((PH = getenv("PHONES")) == NULL)
 177                 PH = _PATH_PHONES;
 178         vinit();                                /* init variables */
 179         setparity("even");                      /* set the parity table */
 180         if ((i = speed(number(value(BAUDRATE)))) == 0) {
 181                 printf("tip: bad baud rate %d\n", number(value(BAUDRATE)));
 182                 (void)uu_unlock(uucplock);
 183                 exit(3);
 184         }
 185
 186         /*
 187          * Now that we have the logfile and the ACU open
 188          *  return to the real uid and gid.  These things will
 189          *  be closed on exit.  Swap real and effective uid's
 190          *  so we can get the original permissions back
 191          *  for removing the uucp lock.
 192          */
 193         user_uid();
 194
 195         /*
 196          * Hardwired connections require the
 197          *  line speed set before they make any transmissions
 198          *  (this is particularly true of things like a DF03-AC)
 199          */
 200         if (HW)
 201                 ttysetup(i);
 202         if ((p = connect())) {
 203                 printf("\07%s\n[EOT]\n", p);
 204                 daemon_uid();
 205                 (void)uu_unlock(uucplock);
 206                 exit(1);
 207         }
 208         if (!HW)
 209                 ttysetup(i);
 210 cucommon:
 211         /*
 212          * From here down the code is shared with
 213          * the "cu" version of tip.
 214          */
 215
 216 #if HAVE_TERMIOS
 217         tcgetattr (0, &otermios);
 218         ctermios = otermios;
 219 #ifndef _POSIX_SOURCE
 220         ctermios.c_iflag = (IMAXBEL|IXANY|ISTRIP|IXON|BRKINT);
 221         ctermios.c_lflag = (PENDIN|IEXTEN|ISIG|ECHOCTL|ECHOE|ECHOKE);
 222 #else
 223         ctermios.c_iflag = (ISTRIP|IXON|BRKINT);
 224         ctermios.c_lflag = (PENDIN|IEXTEN|ISIG|ECHOE);
 225 #endif
 226         ctermios.c_cflag = (CLOCAL|HUPCL|CREAD|CS8);
 227         ctermios.c_cc[VINTR] =  ctermios.c_cc[VQUIT] = -1;
 228         ctermios.c_cc[VSUSP] = ctermios.c_cc[VDSUSP] = ctermios.c_cc[VDISCARD] =
 229                 ctermios.c_cc[VLNEXT] = -1;
 230 #else /* HAVE_TERMIOS */
 231         ioctl(0, TIOCGETP, (char *)&defarg);
 232         ioctl(0, TIOCGETC, (char *)&defchars);
 233         ioctl(0, TIOCGLTC, (char *)&deflchars);
 234         ioctl(0, TIOCGETD, (char *)&odisc);
 235         arg = defarg;
 236         arg.sg_flags = ANYP | CBREAK;
 237         tchars = defchars;
 238         tchars.t_intrc = tchars.t_quitc = -1;
 239         ltchars = deflchars;
 240         ltchars.t_suspc = ltchars.t_dsuspc = ltchars.t_flushc
 241                 = ltchars.t_lnextc = -1;
 242 #endif /* HAVE_TERMIOS */
 243         raw();
 244
 245         pipe(fildes); pipe(repdes);
 246         (void)signal(SIGALRM, timeoutfunc);
 247
 248         /*
 249          * Everything's set up now:
 250          *      connection established (hardwired or dialup)
 251          *      line conditioned (baud rate, mode, etc.)
 252          *      internal data structures (variables)
 253          * so, fork one process for local side and one for remote.
 254          */
 255         printf(cumode ? "Connected\r\n" : "\07connected\r\n");
 256
 257         if (LI != NULL && tiplink (LI, 0) != 0) {
 258                 tipabort ("login failed");
 259         }
 260
 261         if ((pid = fork()))
 262                 tipin();
 263         else
 264                 tipout();
 265         /*NOTREACHED*/
 266 }
 267
 268 static void
 269 usage(void)
 270 {
 271         fprintf(stderr, "usage: tip [-v] [-speed] [system-name]\n");
 272         exit(1);
 273 }
 274
 275 void
 276 killchild(void)
 277 {
 278         if (pid != 0) {
 279                 kill(pid, SIGTERM);
 280                 pid = 0;
 281         }
 282 }
 283
 284 void
 285 cleanup(int signo)
 286 {
 287
 288         daemon_uid();
 289         (void)uu_unlock(uucplock);
 290 #if !HAVE_TERMIOS
 291         if (odisc)
 292                 ioctl(0, TIOCSETD, (char *)&odisc);
 293 #endif
 294         exit(0);
 295 }
 296
 297 void
 298 tipdone(int signo)
 299 {
 300         tipabort("Hangup.");
 301 }
 302 /*
 303  * Muck with user ID's.  We are setuid to the owner of the lock
 304  * directory when we start.  user_uid() reverses real and effective
 305  * ID's after startup, to run with the user's permissions.
 306  * daemon_uid() switches back to the privileged uid for unlocking.
 307  * Finally, to avoid running a shell with the wrong real uid,
 308  * shell_uid() sets real and effective uid's to the user's real ID.
 309  */
 310 static int uidswapped;
 311
 312 void
 313 user_uid(void)
 314 {
 315         if (uidswapped == 0) {
 316                 seteuid(uid);
 317                 uidswapped = 1;
 318         }
 319 }
 320
 321 void
 322 daemon_uid(void)
 323 {
 324         if (uidswapped) {
 325                 seteuid(euid);
 326                 uidswapped = 0;
 327         }
 328 }
 329
 330 void
 331 shell_uid(void)
 332 {
 333         setegid(gid);
 334         seteuid(uid);
 335 }
 336
 337 /*
 338  * put the controlling keyboard into raw mode
 339  */
 340 void
 341 raw(void)
 342 {
 343 #if HAVE_TERMIOS
 344         tcsetattr (0, TCSANOW, &ctermios);
 345 #else /* HAVE_TERMIOS */
 346
 347         ioctl(0, TIOCSETP, &arg);
 348         ioctl(0, TIOCSETC, &tchars);
 349         ioctl(0, TIOCSLTC, &ltchars);
 350         ioctl(0, TIOCSETD, (char *)&disc);
 351 #endif /* HAVE_TERMIOS */
 352 }
 353
 354
 355 /*
 356  * return keyboard to normal mode
 357  */
 358 void
 359 unraw(void)
 360 {
 361 #if HAVE_TERMIOS
 362         tcsetattr (0, TCSANOW, &otermios);
 363 #else /* HAVE_TERMIOS */
 364
 365         ioctl(0, TIOCSETD, (char *)&odisc);
 366         ioctl(0, TIOCSETP, (char *)&defarg);
 367         ioctl(0, TIOCSETC, (char *)&defchars);
 368         ioctl(0, TIOCSLTC, (char *)&deflchars);
 369 #endif /* HAVE_TERMIOS */
 370 }
 371
 372 static  jmp_buf promptbuf;
 373
 374 /*
 375  * Print string ``s'', then read a string
 376  *  in from the terminal.  Handles signals & allows use of
 377  *  normal erase and kill characters.
 378  */
 379 int
 380 prompt(char *s, char *p, size_t sz)
 381 {
 382         char *b = p;
 383         sig_t oint, oquit;
 384
 385         stoprompt = 0;
 386         oint = signal(SIGINT, intprompt);
 387         oquit = signal(SIGQUIT, SIG_IGN);
 388         unraw();
 389         printf("%s", s);
 390         if (setjmp(promptbuf) == 0)
 391                 while ((*p = getchar()) != EOF && *p != '\n' && --sz > 0)
 392                         p++;
 393         *p = '\0';
 394
 395         raw();
 396         (void)signal(SIGINT, oint);
 397         (void)signal(SIGQUIT, oquit);
 398         return (stoprompt || p == b);
 399 }
 400
 401 /*
 402  * Interrupt service routine during prompting
 403  */
 404 void
 405 intprompt(int signo)
 406 {
 407
 408         (void)signal(SIGINT, SIG_IGN);
 409         stoprompt = 1;
 410         printf("\r\n");
 411         longjmp(promptbuf, 1);
 412 }
 413
 414 /*
 415  * ****TIPIN   TIPIN****
 416  */
 417 void
 418 tipin(void)
 419 {
 420         int i;
 421         char gch, bol = 1;
 422
 423         atexit(killchild);
 424
 425         /*
 426          * Kinda klugey here...
 427          *   check for scripting being turned on from the .tiprc file,
 428          *   but be careful about just using setscript(), as we may
 429          *   send a SIGEMT before tipout has a chance to set up catching
 430          *   it; so wait a second, then setscript()
 431          */
 432         if (boolean(value(SCRIPT))) {
 433                 sleep(1);
 434                 setscript();
 435         }
 436
 437         while (1) {
 438                 i = getchar();
 439                 if (i == EOF)
 440                         break;
 441                 gch = i&0177;
 442                 if ((gch == character(value(ESCAPE))) && bol) {
 443                         if (!(gch = escape()))
 444                                 continue;
 445                 } else if (!cumode && gch == character(value(RAISECHAR))) {
 446                         boolean(value(RAISE)) = !boolean(value(RAISE));
 447                         continue;
 448                 } else if (gch == '\r') {
 449                         bol = 1;
 450                         xpwrite(FD, &gch, 1);
 451                         if (boolean(value(HALFDUPLEX)))
 452                                 printf("\r\n");
 453                         continue;
 454                 } else if (!cumode && gch == character(value(FORCE))) {
 455                         i = getchar();
 456                         if (i == EOF)
 457                                 break;
 458                         gch = i & 0177;
 459                 }
 460                 bol = any(gch, value(EOL));
 461                 if (boolean(value(RAISE)) && islower(gch))
 462                         gch = toupper(gch);
 463                 xpwrite(FD, &gch, 1);
 464                 if (boolean(value(HALFDUPLEX)))
 465                         printf("%c", gch);
 466         }
 467 }
 468
 469 extern esctable_t etable[];
 470
 471 /*
 472  * Escape handler --
 473  *  called on recognition of ``escapec'' at the beginning of a line
 474  */
 475 char
 476 escape(void)
 477 {
 478         char gch;
 479         esctable_t *p;
 480         char c = character(value(ESCAPE));
 481         int i;
 482
 483         i = getchar();
 484         if (i == EOF)
 485                 return 0;
 486         gch = (i&0177);
 487         for (p = etable; p->e_char; p++)
 488                 if (p->e_char == gch) {
 489                         if ((p->e_flags&PRIV) && uid)
 490                                 continue;
 491                         printf("%s", ctrl(c));
 492                         (*p->e_func)(gch);
 493                         return (0);
 494                 }
 495         /* ESCAPE ESCAPE forces ESCAPE */
 496         if (c != gch)
 497                 xpwrite(FD, &c, 1);
 498         return (gch);
 499 }
 500
 501 int
 502 speed(int n)
 503 {
 504 #if HAVE_TERMIOS
 505         return (n);
 506 #else
 507         CONST int *p;
 508
 509         for (p = bauds; *p != -1;  p++)
 510                 if (*p == n)
 511                         return (p - bauds);
 512         return (NULL);
 513 #endif
 514 }
 515
 516 int
 517 any(char c, char *p)
 518 {
 519         while (p && *p)
 520                 if (*p++ == c)
 521                         return (1);
 522         return (0);
 523 }
 524
 525 int
 526 size(char *s)
 527 {
 528         int i = 0;
 529
 530         while (s && *s++)
 531                 i++;
 532         return (i);
 533 }
 534
 535 char *
 536 interp(char *s)
 537 {
 538         static char buf[256];
 539         char *p = buf, c, *q;
 540
 541         while ((c = *s++)) {
 542                 for (q = "\nn\rr\tt\ff\033E\bb"; *q; q++)
 543                         if (*q++ == c) {
 544                                 *p++ = '\\'; *p++ = *q;
 545                                 goto next;
 546                         }
 547                 if (c < 040) {
 548                         *p++ = '^'; *p++ = c + 'A'-1;
 549                 } else if (c == 0177) {
 550                         *p++ = '^'; *p++ = '?';
 551                 } else
 552                         *p++ = c;
 553         next:
 554                 ;
 555         }
 556         *p = '\0';
 557         return (buf);
 558 }
 559
 560 char *
 561 ctrl(char c)
 562 {
 563         static char s[3];
 564
 565         if (c < 040 || c == 0177) {
 566                 s[0] = '^';
 567                 s[1] = c == 0177 ? '?' : c+'A'-1;
 568                 s[2] = '\0';
 569         } else {
 570                 s[0] = c;
 571                 s[1] = '\0';
 572         }
 573         return (s);
 574 }
 575
 576 /*
 577  * Help command
 578  */
 579 void
 580 help(int c)
 581 {
 582         esctable_t *p;
 583
 584         printf("%c\r\n", c);
 585         for (p = etable; p->e_char; p++) {
 586                 if ((p->e_flags&PRIV) && uid)
 587                         continue;
 588                 printf("%2s", ctrl(character(value(ESCAPE))));
 589                 printf("%-2s %c   %s\r\n", ctrl(p->e_char),
 590                         p->e_flags&EXP ? '*': ' ', p->e_help);
 591         }
 592 }
 593
 594 /*
 595  * Set up the "remote" tty's state
 596  */
 597 void
 598 ttysetup (int speed)
 599 {
 600 #if HAVE_TERMIOS
 601         struct termios termios;
 602         tcgetattr (FD, &termios);
 603         if (boolean(value(TAND)))
 604                 termios.c_iflag = IXOFF;
 605         else
 606                 termios.c_iflag = 0;
 607 #ifndef _POSIX_SOURCE
 608         termios.c_lflag = (PENDIN|ECHOKE|ECHOE);
 609 #else
 610         termios.c_lflag = (PENDIN|ECHOE);
 611 #endif
 612         termios.c_cflag = (CLOCAL|HUPCL|CREAD|CS8);
 613         termios.c_ispeed = termios.c_ospeed = speed;
 614         tcsetattr (FD, TCSANOW, &termios);
 615 #else /* HAVE_TERMIOS */
 616         unsigned bits = LDECCTQ;
 617
 618         arg.sg_ispeed = arg.sg_ospeed = speed;
 619         arg.sg_flags = RAW;
 620         if (boolean(value(TAND)))
 621                 arg.sg_flags |= TANDEM;
 622         ioctl(FD, TIOCSETP, (char *)&arg);
 623         ioctl(FD, TIOCLBIS, (char *)&bits);
 624 #endif /* HAVE_TERMIOS */
 625 }
 626
 627 /*
 628  * Return "simple" name from a file name,
 629  * strip leading directories.
 630  */
 631 char *
 632 sname(char *s)
 633 {
 634         char *p = s;
 635
 636         while (*s)
 637                 if (*s++ == '/')
 638                         p = s;
 639         return (p);
 640 }
 641
 642 static char partab[0200];
 643 static int bits8;
 644
 645 /*
 646  * Do a write to the remote machine with the correct parity.
 647  * We are doing 8 bit wide output, so we just generate a character
 648  * with the right parity and output it.
 649  */
 650 void
 651 xpwrite(int fd, char *buf, int n)
 652 {
 653         int i;
 654         char *bp;
 655
 656         bp = buf;
 657         if (bits8 == 0)
 658                 for (i = 0; i < n; i++) {
 659                         *bp = partab[(*bp) & 0177];
 660                         bp++;
 661                 }
 662         if (write(fd, buf, n) < 0) {
 663                 if (errno == EIO)
 664                         tipabort("Lost carrier.");
 665                 if (errno == ENODEV)
 666                         tipabort("tty not available.");
 667                 tipabort("Something wrong...");
 668         }
 669 }
 670
 671 /*
 672  * Build a parity table with appropriate high-order bit.
 673  */
 674 void
 675 setparity(char *defparity)
 676 {
 677         int i, flip, clr, set;
 678         char *parity;
 679         extern char evenpartab[];
 680
 681         if (value(PARITY) == NULL)
 682                 value(PARITY) = defparity;
 683         parity = value(PARITY);
 684         if (equal(parity, "none")) {
 685                 bits8 = 1;
 686                 return;
 687         }
 688         bits8 = 0;
 689         flip = 0;
 690         clr = 0377;
 691         set = 0;
 692         if (equal(parity, "odd"))
 693                 flip = 0200;                    /* reverse bit 7 */
 694         else if (equal(parity, "zero"))
 695                 clr = 0177;                     /* turn off bit 7 */
 696         else if (equal(parity, "one"))
 697                 set = 0200;                     /* turn on bit 7 */
 698         else if (!equal(parity, "even")) {
 699                 (void) fprintf(stderr, "%s: unknown parity value\r\n", parity);
 700                 (void) fflush(stderr);
 701         }
 702         for (i = 0; i < 0200; i++)
 703                 partab[i] = (evenpartab[i] ^ flip) | (set & clr);
 704 }