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