libexec/getty/subr.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  * @(#)from: subr.c     8.1 (Berkeley) 6/4/93
  34  * $FreeBSD: src/libexec/getty/subr.c,v 1.16.2.1 2001/05/12 10:16:51 kris Exp $
  35  * $DragonFly: src/libexec/getty/subr.c,v 1.4 2004/03/26 00:30:12 cpressey Exp $
  36  */
  37
  38 /*
  39  * Melbourne getty.
  40  */
  41 #define COMPAT_43
  42 #ifdef DEBUG
  43 #include <stdio.h>
  44 #endif
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <termios.h>
  48 #include <unistd.h>
  49 #include <sys/ioctl.h>
  50 #include <sys/param.h>
  51 #include <sys/time.h>
  52 #include <syslog.h>
  53
  54 #include "gettytab.h"
  55 #include "pathnames.h"
  56 #include "extern.h"
  57
  58
  59 #ifdef COMPAT_43
  60 static void     compatflags (long);
  61 #endif
  62
  63 /*
  64  * Get a table entry.
  65  */
  66 void
  67 gettable(const char *name, char *buf)
  68 {
  69         struct gettystrs *sp;
  70         struct gettynums *np;
  71         struct gettyflags *fp;
  72         long n;
  73         int l;
  74         char *p;
  75         char *msg = NULL;
  76         const char *dba[2];
  77
  78         static int firsttime = 1;
  79
  80         dba[0] = _PATH_GETTYTAB;
  81         dba[1] = 0;
  82
  83         if (firsttime) {
  84                 /*
  85                  * we need to strdup() anything in the strings array
  86                  * initially in order to simplify things later
  87                  */
  88                 for (sp = gettystrs; sp->field; sp++)
  89                         if (sp->value != NULL) {
  90                                 /* handle these ones more carefully */
  91                                 if (sp >= &gettystrs[4] && sp <= &gettystrs[6])
  92                                         l = 2;
  93                                 else
  94                                         l = strlen(sp->value) + 1;
  95                                 if ((p = malloc(l)) != NULL) {
  96                                         strncpy(p, sp->value, l);
  97                                         p[l-1] = '\0';
  98                                 }
  99                                 /*
 100                                  * replace, even if NULL, else we'll
 101                                  * have problems with free()ing static mem
 102                                  */
 103                                 sp->value = p;
 104                         }
 105                 firsttime = 0;
 106         }
 107
 108         switch (cgetent(&buf, (char **)dba, (char *)name)) {
 109         case 1:
 110                 msg = "%s: couldn't resolve 'tc=' in gettytab '%s'";
 111         case 0:
 112                 break;
 113         case -1:
 114                 msg = "%s: unknown gettytab entry '%s'";
 115                 break;
 116         case -2:
 117                 msg = "%s: retrieving gettytab entry '%s': %m";
 118                 break;
 119         case -3:
 120                 msg = "%s: recursive 'tc=' reference gettytab entry '%s'";
 121                 break;
 122         default:
 123                 msg = "%s: unexpected cgetent() error for entry '%s'";
 124                 break;
 125         }
 126
 127         if (msg != NULL) {
 128                 syslog(LOG_ERR, msg, "getty", name);
 129                 return;
 130         }
 131
 132         for (sp = gettystrs; sp->field; sp++) {
 133                 if ((l = cgetstr(buf, (char*)sp->field, &p)) >= 0) {
 134                         if (sp->value) {
 135                                 /* prefer existing value */
 136                                 if (strcmp(p, sp->value) != 0)
 137                                         free(sp->value);
 138                                 else {
 139                                         free(p);
 140                                         p = sp->value;
 141                                 }
 142                         }
 143                         sp->value = p;
 144                 } else if (l == -1) {
 145                         free(sp->value);
 146                         sp->value = NULL;
 147                 }
 148         }
 149
 150         for (np = gettynums; np->field; np++) {
 151                 if (cgetnum(buf, (char*)np->field, &n) == -1)
 152                         np->set = 0;
 153                 else {
 154                         np->set = 1;
 155                         np->value = n;
 156                 }
 157         }
 158
 159         for (fp = gettyflags; fp->field; fp++) {
 160                 if (cgetcap(buf, (char *)fp->field, ':') == NULL)
 161                         fp->set = 0;
 162                 else {
 163                         fp->set = 1;
 164                         fp->value = 1 ^ fp->invrt;
 165                 }
 166         }
 167
 168 #ifdef DEBUG
 169         printf("name=\"%s\", buf=\"%s\"\r\n", name, buf);
 170         for (sp = gettystrs; sp->field; sp++)
 171                 printf("cgetstr: %s=%s\r\n", sp->field, sp->value);
 172         for (np = gettynums; np->field; np++)
 173                 printf("cgetnum: %s=%d\r\n", np->field, np->value);
 174         for (fp = gettyflags; fp->field; fp++)
 175                 printf("cgetflags: %s='%c' set='%c'\r\n", fp->field,
 176                        fp->value + '0', fp->set + '0');
 177 #endif /* DEBUG */
 178 }
 179
 180 void
 181 gendefaults(void)
 182 {
 183         struct gettystrs *sp;
 184         struct gettynums *np;
 185         struct gettyflags *fp;
 186
 187         for (sp = gettystrs; sp->field; sp++)
 188                 if (sp->value)
 189                         sp->defalt = strdup(sp->value);
 190         for (np = gettynums; np->field; np++)
 191                 if (np->set)
 192                         np->defalt = np->value;
 193         for (fp = gettyflags; fp->field; fp++)
 194                 if (fp->set)
 195                         fp->defalt = fp->value;
 196                 else
 197                         fp->defalt = fp->invrt;
 198 }
 199
 200 void
 201 setdefaults(void)
 202 {
 203         struct gettystrs *sp;
 204         struct gettynums *np;
 205         struct gettyflags *fp;
 206
 207         for (sp = gettystrs; sp->field; sp++)
 208                 if (!sp->value)
 209                         sp->value = !sp->defalt ? sp->defalt
 210                                                 : strdup(sp->defalt);
 211         for (np = gettynums; np->field; np++)
 212                 if (!np->set)
 213                         np->value = np->defalt;
 214         for (fp = gettyflags; fp->field; fp++)
 215                 if (!fp->set)
 216                         fp->value = fp->defalt;
 217 }
 218
 219 static char **
 220 charnames[] = {
 221         &ER, &KL, &IN, &QU, &XN, &XF, &ET, &BK,
 222         &SU, &DS, &RP, &FL, &WE, &LN, 0
 223 };
 224
 225 static char *
 226 charvars[] = {
 227         &tmode.c_cc[VERASE], &tmode.c_cc[VKILL], &tmode.c_cc[VINTR],
 228         &tmode.c_cc[VQUIT], &tmode.c_cc[VSTART], &tmode.c_cc[VSTOP],
 229         &tmode.c_cc[VEOF], &tmode.c_cc[VEOL], &tmode.c_cc[VSUSP],
 230         &tmode.c_cc[VDSUSP], &tmode.c_cc[VREPRINT], &tmode.c_cc[VDISCARD],
 231         &tmode.c_cc[VWERASE], &tmode.c_cc[VLNEXT], 0
 232 };
 233
 234 void
 235 setchars(void)
 236 {
 237         int i;
 238         const char *p;
 239
 240         for (i = 0; charnames[i]; i++) {
 241                 p = *charnames[i];
 242                 if (p && *p)
 243                         *charvars[i] = *p;
 244                 else
 245                         *charvars[i] = _POSIX_VDISABLE;
 246         }
 247 }
 248
 249 /* Macros to clear/set/test flags. */
 250 #define SET(t, f)       (t) |= (f)
 251 #define CLR(t, f)       (t) &= ~(f)
 252 #define ISSET(t, f)     ((t) & (f))
 253
 254 void
 255 set_flags(int n)
 256 {
 257         tcflag_t iflag, oflag, cflag, lflag;
 258
 259 #ifdef COMPAT_43
 260         switch (n) {
 261         case 0:
 262                 if (F0set) {
 263                         compatflags(F0);
 264                         return;
 265                 }
 266                 break;
 267         case 1:
 268                 if (F1set) {
 269                         compatflags(F1);
 270                         return;
 271                 }
 272                 break;
 273         default:
 274                 if (F2set) {
 275                         compatflags(F2);
 276                         return;
 277                 }
 278                 break;
 279         }
 280 #endif
 281
 282         switch (n) {
 283         case 0:
 284                 if (C0set && I0set && L0set && O0set) {
 285                         tmode.c_cflag = C0;
 286                         tmode.c_iflag = I0;
 287                         tmode.c_lflag = L0;
 288                         tmode.c_oflag = O0;
 289                         return;
 290                 }
 291                 break;
 292         case 1:
 293                 if (C1set && I1set && L1set && O1set) {
 294                         tmode.c_cflag = C1;
 295                         tmode.c_iflag = I1;
 296                         tmode.c_lflag = L1;
 297                         tmode.c_oflag = O1;
 298                         return;
 299                 }
 300                 break;
 301         default:
 302                 if (C2set && I2set && L2set && O2set) {
 303                         tmode.c_cflag = C2;
 304                         tmode.c_iflag = I2;
 305                         tmode.c_lflag = L2;
 306                         tmode.c_oflag = O2;
 307                         return;
 308                 }
 309                 break;
 310         }
 311
 312         iflag = omode.c_iflag;
 313         oflag = omode.c_oflag;
 314         cflag = omode.c_cflag;
 315         lflag = omode.c_lflag;
 316
 317         if (NP) {
 318                 CLR(cflag, CSIZE|PARENB);
 319                 SET(cflag, CS8);
 320                 CLR(iflag, ISTRIP|INPCK|IGNPAR);
 321         } else if (AP || EP || OP) {
 322                 CLR(cflag, CSIZE);
 323                 SET(cflag, CS7|PARENB);
 324                 SET(iflag, ISTRIP);
 325                 if (OP && !EP) {
 326                         SET(iflag, INPCK|IGNPAR);
 327                         SET(cflag, PARODD);
 328                         if (AP)
 329                                 CLR(iflag, INPCK);
 330                 } else if (EP && !OP) {
 331                         SET(iflag, INPCK|IGNPAR);
 332                         CLR(cflag, PARODD);
 333                         if (AP)
 334                                 CLR(iflag, INPCK);
 335                 } else if (AP || (EP && OP)) {
 336                         CLR(iflag, INPCK|IGNPAR);
 337                         CLR(cflag, PARODD);
 338                 }
 339         } /* else, leave as is */
 340
 341 #if 0
 342         if (UC)
 343                 f |= LCASE;
 344 #endif
 345
 346         if (HC)
 347                 SET(cflag, HUPCL);
 348         else
 349                 CLR(cflag, HUPCL);
 350
 351         if (MB)
 352                 SET(cflag, MDMBUF);
 353         else
 354                 CLR(cflag, MDMBUF);
 355
 356         if (HW)
 357                 SET(cflag, CRTSCTS);
 358         else
 359                 CLR(cflag, CRTSCTS);
 360
 361         if (NL) {
 362                 SET(iflag, ICRNL);
 363                 SET(oflag, ONLCR|OPOST);
 364         } else {
 365                 CLR(iflag, ICRNL);
 366                 CLR(oflag, ONLCR);
 367         }
 368
 369         if (!HT)
 370                 SET(oflag, OXTABS|OPOST);
 371         else
 372                 CLR(oflag, OXTABS);
 373
 374 #ifdef XXX_DELAY
 375         SET(f, delaybits());
 376 #endif
 377
 378         if (n == 1) {           /* read mode flags */
 379                 if (RW) {
 380                         iflag = 0;
 381                         CLR(oflag, OPOST);
 382                         CLR(cflag, CSIZE|PARENB);
 383                         SET(cflag, CS8);
 384                         lflag = 0;
 385                 } else {
 386                         CLR(lflag, ICANON);
 387                 }
 388                 goto out;
 389         }
 390
 391         if (n == 0)
 392                 goto out;
 393
 394 #if 0
 395         if (CB)
 396                 SET(f, CRTBS);
 397 #endif
 398
 399         if (CE)
 400                 SET(lflag, ECHOE);
 401         else
 402                 CLR(lflag, ECHOE);
 403
 404         if (CK)
 405                 SET(lflag, ECHOKE);
 406         else
 407                 CLR(lflag, ECHOKE);
 408
 409         if (PE)
 410                 SET(lflag, ECHOPRT);
 411         else
 412                 CLR(lflag, ECHOPRT);
 413
 414         if (EC)
 415                 SET(lflag, ECHO);
 416         else
 417                 CLR(lflag, ECHO);
 418
 419         if (XC)
 420                 SET(lflag, ECHOCTL);
 421         else
 422                 CLR(lflag, ECHOCTL);
 423
 424         if (DX)
 425                 SET(lflag, IXANY);
 426         else
 427                 CLR(lflag, IXANY);
 428
 429 out:
 430         tmode.c_iflag = iflag;
 431         tmode.c_oflag = oflag;
 432         tmode.c_cflag = cflag;
 433         tmode.c_lflag = lflag;
 434 }
 435
 436 #ifdef COMPAT_43
 437 /*
 438  * Old TTY => termios, snatched from <sys/kern/tty_compat.c>
 439  */
 440 void
 441 compatflags(long flags)
 442 {
 443         tcflag_t iflag, oflag, cflag, lflag;
 444
 445         iflag = BRKINT|ICRNL|IMAXBEL|IXON|IXANY;
 446         oflag = OPOST|ONLCR|OXTABS;
 447         cflag = CREAD;
 448         lflag = ICANON|ISIG|IEXTEN;
 449
 450         if (ISSET(flags, TANDEM))
 451                 SET(iflag, IXOFF);
 452         else
 453                 CLR(iflag, IXOFF);
 454         if (ISSET(flags, ECHO))
 455                 SET(lflag, ECHO);
 456         else
 457                 CLR(lflag, ECHO);
 458         if (ISSET(flags, CRMOD)) {
 459                 SET(iflag, ICRNL);
 460                 SET(oflag, ONLCR);
 461         } else {
 462                 CLR(iflag, ICRNL);
 463                 CLR(oflag, ONLCR);
 464         }
 465         if (ISSET(flags, XTABS))
 466                 SET(oflag, OXTABS);
 467         else
 468                 CLR(oflag, OXTABS);
 469
 470
 471         if (ISSET(flags, RAW)) {
 472                 iflag &= IXOFF;
 473                 CLR(lflag, ISIG|ICANON|IEXTEN);
 474                 CLR(cflag, PARENB);
 475         } else {
 476                 SET(iflag, BRKINT|IXON|IMAXBEL);
 477                 SET(lflag, ISIG|IEXTEN);
 478                 if (ISSET(flags, CBREAK))
 479                         CLR(lflag, ICANON);
 480                 else
 481                         SET(lflag, ICANON);
 482                 switch (ISSET(flags, ANYP)) {
 483                 case 0:
 484                         CLR(cflag, PARENB);
 485                         break;
 486                 case ANYP:
 487                         SET(cflag, PARENB);
 488                         CLR(iflag, INPCK);
 489                         break;
 490                 case EVENP:
 491                         SET(cflag, PARENB);
 492                         SET(iflag, INPCK);
 493                         CLR(cflag, PARODD);
 494                         break;
 495                 case ODDP:
 496                         SET(cflag, PARENB);
 497                         SET(iflag, INPCK);
 498                         SET(cflag, PARODD);
 499                         break;
 500                 }
 501         }
 502
 503         /* Nothing we can do with CRTBS. */
 504         if (ISSET(flags, PRTERA))
 505                 SET(lflag, ECHOPRT);
 506         else
 507                 CLR(lflag, ECHOPRT);
 508         if (ISSET(flags, CRTERA))
 509                 SET(lflag, ECHOE);
 510         else
 511                 CLR(lflag, ECHOE);
 512         /* Nothing we can do with TILDE. */
 513         if (ISSET(flags, MDMBUF))
 514                 SET(cflag, MDMBUF);
 515         else
 516                 CLR(cflag, MDMBUF);
 517         if (ISSET(flags, NOHANG))
 518                 CLR(cflag, HUPCL);
 519         else
 520                 SET(cflag, HUPCL);
 521         if (ISSET(flags, CRTKIL))
 522                 SET(lflag, ECHOKE);
 523         else
 524                 CLR(lflag, ECHOKE);
 525         if (ISSET(flags, CTLECH))
 526                 SET(lflag, ECHOCTL);
 527         else
 528                 CLR(lflag, ECHOCTL);
 529         if (!ISSET(flags, DECCTQ))
 530                 SET(iflag, IXANY);
 531         else
 532                 CLR(iflag, IXANY);
 533         CLR(lflag, TOSTOP|FLUSHO|PENDIN|NOFLSH);
 534         SET(lflag, ISSET(flags, TOSTOP|FLUSHO|PENDIN|NOFLSH));
 535
 536         if (ISSET(flags, RAW|LITOUT|PASS8)) {
 537                 CLR(cflag, CSIZE);
 538                 SET(cflag, CS8);
 539                 if (!ISSET(flags, RAW|PASS8))
 540                         SET(iflag, ISTRIP);
 541                 else
 542                         CLR(iflag, ISTRIP);
 543                 if (!ISSET(flags, RAW|LITOUT))
 544                         SET(oflag, OPOST);
 545                 else
 546                         CLR(oflag, OPOST);
 547         } else {
 548                 CLR(cflag, CSIZE);
 549                 SET(cflag, CS7);
 550                 SET(iflag, ISTRIP);
 551                 SET(oflag, OPOST);
 552         }
 553
 554         tmode.c_iflag = iflag;
 555         tmode.c_oflag = oflag;
 556         tmode.c_cflag = cflag;
 557         tmode.c_lflag = lflag;
 558 }
 559 #endif
 560
 561 #ifdef XXX_DELAY
 562 struct delayval {
 563         unsigned        delay;          /* delay in ms */
 564         int             bits;
 565 };
 566
 567 /*
 568  * below are random guesses, I can't be bothered checking
 569  */
 570
 571 struct delayval crdelay[] = {
 572         { 1,            CR1 },
 573         { 2,            CR2 },
 574         { 3,            CR3 },
 575         { 83,           CR1 },
 576         { 166,          CR2 },
 577         { 0,            CR3 },
 578 };
 579
 580 struct delayval nldelay[] = {
 581         { 1,            NL1 },          /* special, calculated */
 582         { 2,            NL2 },
 583         { 3,            NL3 },
 584         { 100,          NL2 },
 585         { 0,            NL3 },
 586 };
 587
 588 struct delayval bsdelay[] = {
 589         { 1,            BS1 },
 590         { 0,            0 },
 591 };
 592
 593 struct delayval ffdelay[] = {
 594         { 1,            FF1 },
 595         { 1750,         FF1 },
 596         { 0,            FF1 },
 597 };
 598
 599 struct delayval tbdelay[] = {
 600         { 1,            TAB1 },
 601         { 2,            TAB2 },
 602         { 3,            XTABS },        /* this is expand tabs */
 603         { 100,          TAB1 },
 604         { 0,            TAB2 },
 605 };
 606
 607 int
 608 delaybits(void)
 609 {
 610         int f;
 611
 612         f  = adelay(CD, crdelay);
 613         f |= adelay(ND, nldelay);
 614         f |= adelay(FD, ffdelay);
 615         f |= adelay(TD, tbdelay);
 616         f |= adelay(BD, bsdelay);
 617         return (f);
 618 }
 619
 620 int
 621 adelay(int ms, struct delayval *dp)
 622 {
 623         if (ms == 0)
 624                 return (0);
 625         while (dp->delay && ms > dp->delay)
 626                 dp++;
 627         return (dp->bits);
 628 }
 629 #endif
 630
 631 char    editedhost[MAXHOSTNAMELEN];
 632
 633 void
 634 edithost(const char *pat)
 635 {
 636         const char *host = HN;
 637         char *res = editedhost;
 638
 639         if (!pat)
 640                 pat = "";
 641         while (*pat) {
 642                 switch (*pat) {
 643
 644                 case '#':
 645                         if (*host)
 646                                 host++;
 647                         break;
 648
 649                 case '@':
 650                         if (*host)
 651                                 *res++ = *host++;
 652                         break;
 653
 654                 default:
 655                         *res++ = *pat;
 656                         break;
 657
 658                 }
 659                 if (res == &editedhost[sizeof editedhost - 1]) {
 660                         *res = '\0';
 661                         return;
 662                 }
 663                 pat++;
 664         }
 665         if (*host)
 666                 strncpy(res, host, sizeof editedhost - (res - editedhost) - 1);
 667         else
 668                 *res = '\0';
 669         editedhost[sizeof editedhost - 1] = '\0';
 670 }
 671
 672 static struct speedtab {
 673         int     speed;
 674         int     uxname;
 675 } speedtab[] = {
 676         { 50,   B50 },
 677         { 75,   B75 },
 678         { 110,  B110 },
 679         { 134,  B134 },
 680         { 150,  B150 },
 681         { 200,  B200 },
 682         { 300,  B300 },
 683         { 600,  B600 },
 684         { 1200, B1200 },
 685         { 1800, B1800 },
 686         { 2400, B2400 },
 687         { 4800, B4800 },
 688         { 9600, B9600 },
 689         { 19200, EXTA },
 690         { 19,   EXTA },         /* for people who say 19.2K */
 691         { 38400, EXTB },
 692         { 38,   EXTB },
 693         { 7200, EXTB },         /* alternative */
 694         { 57600, B57600 },
 695         { 115200, B115200 },
 696         { 230400, B230400 },
 697         { 0 }
 698 };
 699
 700 int
 701 speed(int val)
 702 {
 703         struct speedtab *sp;
 704
 705         if (val <= B230400)
 706                 return (val);
 707
 708         for (sp = speedtab; sp->speed; sp++)
 709                 if (sp->speed == val)
 710                         return (sp->uxname);
 711
 712         return (B300);          /* default in impossible cases */
 713 }
 714
 715 void
 716 makeenv(char *env[])
 717 {
 718         static char termbuf[128] = "TERM=";
 719         char *p, *q;
 720         char **ep;
 721
 722         ep = env;
 723         if (TT && *TT) {
 724                 strlcat(termbuf, TT, sizeof(termbuf));
 725                 *ep++ = termbuf;
 726         }
 727         if ((p = EV)) {
 728                 q = p;
 729                 while ((q = strchr(q, ','))) {
 730                         *q++ = '\0';
 731                         *ep++ = p;
 732                         p = q;
 733                 }
 734                 if (*p)
 735                         *ep++ = p;
 736         }
 737         *ep = (char *)0;
 738 }
 739
 740 /*
 741  * This speed select mechanism is written for the Develcon DATASWITCH.
 742  * The Develcon sends a string of the form "B{speed}\n" at a predefined
 743  * baud rate. This string indicates the user's actual speed.
 744  * The routine below returns the terminal type mapped from derived speed.
 745  */
 746 struct  portselect {
 747         const char      *ps_baud;
 748         const char      *ps_type;
 749 } portspeeds[] = {
 750         { "B110",       "std.110" },
 751         { "B134",       "std.134" },
 752         { "B150",       "std.150" },
 753         { "B300",       "std.300" },
 754         { "B600",       "std.600" },
 755         { "B1200",      "std.1200" },
 756         { "B2400",      "std.2400" },
 757         { "B4800",      "std.4800" },
 758         { "B9600",      "std.9600" },
 759         { "B19200",     "std.19200" },
 760         { 0 }
 761 };
 762
 763 const char *
 764 portselector(void)
 765 {
 766         char c, baud[20];
 767         const char *type = "default";
 768         struct portselect *ps;
 769         int len;
 770
 771         alarm(5*60);
 772         for (len = 0; len < sizeof (baud) - 1; len++) {
 773                 if (read(STDIN_FILENO, &c, 1) <= 0)
 774                         break;
 775                 c &= 0177;
 776                 if (c == '\n' || c == '\r')
 777                         break;
 778                 if (c == 'B')
 779                         len = 0;        /* in case of leading garbage */
 780                 baud[len] = c;
 781         }
 782         baud[len] = '\0';
 783         for (ps = portspeeds; ps->ps_baud; ps++)
 784                 if (strcmp(ps->ps_baud, baud) == 0) {
 785                         type = ps->ps_type;
 786                         break;
 787                 }
 788         sleep(2);       /* wait for connection to complete */
 789         return (type);
 790 }
 791
 792 /*
 793  * This auto-baud speed select mechanism is written for the Micom 600
 794  * portselector. Selection is done by looking at how the character '\r'
 795  * is garbled at the different speeds.
 796  */
 797 const char *
 798 autobaud(void)
 799 {
 800         int rfds;
 801         struct timeval timeout;
 802         char c;
 803         const char *type = "9600-baud";
 804
 805         (void)tcflush(0, TCIOFLUSH);
 806         rfds = 1 << 0;
 807         timeout.tv_sec = 5;
 808         timeout.tv_usec = 0;
 809         if (select(32, (fd_set *)&rfds, (fd_set *)NULL,
 810             (fd_set *)NULL, &timeout) <= 0)
 811                 return (type);
 812         if (read(STDIN_FILENO, &c, sizeof(char)) != sizeof(char))
 813                 return (type);
 814         timeout.tv_sec = 0;
 815         timeout.tv_usec = 20;
 816         (void) select(32, (fd_set *)NULL, (fd_set *)NULL,
 817             (fd_set *)NULL, &timeout);
 818         (void)tcflush(0, TCIOFLUSH);
 819         switch (c & 0377) {
 820
 821         case 0200:              /* 300-baud */
 822                 type = "300-baud";
 823                 break;
 824
 825         case 0346:              /* 1200-baud */
 826                 type = "1200-baud";
 827                 break;
 828
 829         case  015:              /* 2400-baud */
 830         case 0215:
 831                 type = "2400-baud";
 832                 break;
 833
 834         default:                /* 4800-baud */
 835                 type = "4800-baud";
 836                 break;
 837
 838         case 0377:              /* 9600-baud */
 839                 type = "9600-baud";
 840                 break;
 841         }
 842         return (type);
 843 }