libexec/getty/main.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1980, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * @(#)from: main.c     8.1 (Berkeley) 6/20/93
  32  * $FreeBSD: head/libexec/getty/main.c 329992 2018-02-25 20:15:06Z trasz $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/time.h>
  38 #include <sys/resource.h>
  39 #include <sys/stat.h>
  40 #include <sys/ttydefaults.h>
  41 #include <sys/utsname.h>
  42
  43 #include <ctype.h>
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <locale.h>
  47 #include <libutil.h>
  48 #include <setjmp.h>
  49 #include <signal.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <syslog.h>
  53 #include <termios.h>
  54 #include <time.h>
  55 #include <unistd.h>
  56
  57 #include "gettytab.h"
  58 #include "extern.h"
  59 #include "pathnames.h"
  60
  61 /*
  62  * Set the amount of running time that getty should accumulate
  63  * before deciding that something is wrong and exit.
  64  */
  65 #define GETTY_TIMEOUT   60 /* seconds */
  66
  67 #undef CTRL
  68 #define CTRL(x)  (x&037)
  69
  70 /* defines for auto detection of incoming PPP calls (->PAP/CHAP) */
  71
  72 #define PPP_FRAME           0x7e  /* PPP Framing character */
  73 #define PPP_STATION         0xff  /* "All Station" character */
  74 #define PPP_ESCAPE          0x7d  /* Escape Character */
  75 #define PPP_CONTROL         0x03  /* PPP Control Field */
  76 #define PPP_CONTROL_ESCAPED 0x23  /* PPP Control Field, escaped */
  77 #define PPP_LCP_HI          0xc0  /* LCP protocol - high byte */
  78 #define PPP_LCP_LOW         0x21  /* LCP protocol - low byte */
  79
  80 /* original mode; flags've been reset using values from <sys/ttydefaults.h> */
  81 struct termios omode;
  82 /* current mode */
  83 struct termios tmode;
  84
  85 static int crmod, digit, lower, upper;
  86
  87 char    hostname[MAXHOSTNAMELEN];
  88 static char     name[MAXLOGNAME*3];
  89 static char     dev[] = _PATH_DEV;
  90 static char     ttyn[32];
  91
  92 #define OBUFSIZ         128
  93 #define TABBUFSIZ       512
  94
  95 static char     defent[TABBUFSIZ];
  96 static char     tabent[TABBUFSIZ];
  97 static const char       *tname;
  98
  99 static char     *env[128];
 100
 101 static char partab[] = {
 102         0001,0201,0201,0001,0201,0001,0001,0201,
 103         0202,0004,0003,0205,0005,0206,0201,0001,
 104         0201,0001,0001,0201,0001,0201,0201,0001,
 105         0001,0201,0201,0001,0201,0001,0001,0201,
 106         0200,0000,0000,0200,0000,0200,0200,0000,
 107         0000,0200,0200,0000,0200,0000,0000,0200,
 108         0000,0200,0200,0000,0200,0000,0000,0200,
 109         0200,0000,0000,0200,0000,0200,0200,0000,
 110         0200,0000,0000,0200,0000,0200,0200,0000,
 111         0000,0200,0200,0000,0200,0000,0000,0200,
 112         0000,0200,0200,0000,0200,0000,0000,0200,
 113         0200,0000,0000,0200,0000,0200,0200,0000,
 114         0000,0200,0200,0000,0200,0000,0000,0200,
 115         0200,0000,0000,0200,0000,0200,0200,0000,
 116         0200,0000,0000,0200,0000,0200,0200,0000,
 117         0000,0200,0200,0000,0200,0000,0000,0201
 118 };
 119
 120 #define ERASE   tmode.c_cc[VERASE]
 121 #define KILL    tmode.c_cc[VKILL]
 122 #define EOT     tmode.c_cc[VEOF]
 123
 124 #define puts    Gputs
 125
 126 static void     defttymode(void);
 127 static void     dingdong(int);
 128 static void     dogettytab(void);
 129 static int      getname(void);
 130 static void     interrupt(int);
 131 static void     oflush(void);
 132 static void     prompt(void);
 133 static void     putchr(int);
 134 static void     putf(const char *);
 135 static void     putpad(const char *);
 136 static void     puts(const char *);
 137 static void     timeoverrun(int);
 138 static char     *get_line(int);
 139 static void     setttymode(int);
 140 static int      opentty(const char *, int);
 141
 142 static jmp_buf timeout;
 143
 144 static void
 145 dingdong(int signo __unused)
 146 {
 147         alarm(0);
 148         longjmp(timeout, 1);
 149 }
 150
 151 static jmp_buf  intrupt;
 152
 153 static void
 154 interrupt(int signo __unused)
 155 {
 156         longjmp(intrupt, 1);
 157 }
 158
 159 /*
 160  * Action to take when getty is running too long.
 161  */
 162 static void
 163 timeoverrun(int signo __unused)
 164 {
 165
 166         syslog(LOG_ERR, "getty exiting due to excessive running time");
 167         exit(1);
 168 }
 169
 170 int
 171 main(int argc, char *argv[])
 172 {
 173         int first_sleep = 1, first_time = 1;
 174         struct rlimit limit;
 175         int rval;
 176
 177         signal(SIGINT, SIG_IGN);
 178         signal(SIGQUIT, SIG_IGN);
 179
 180         openlog("getty", LOG_CONS|LOG_PID, LOG_AUTH);
 181         gethostname(hostname, sizeof(hostname) - 1);
 182         hostname[sizeof(hostname) - 1] = '\0';
 183         if (hostname[0] == '\0')
 184                 strcpy(hostname, "Amnesiac");
 185
 186         /*
 187          * Limit running time to deal with broken or dead lines.
 188          */
 189         (void)signal(SIGXCPU, timeoverrun);
 190         limit.rlim_max = RLIM_INFINITY;
 191         limit.rlim_cur = GETTY_TIMEOUT;
 192         (void)setrlimit(RLIMIT_CPU, &limit);
 193
 194         gettable("default", defent);
 195         gendefaults();
 196         tname = "default";
 197         if (argc > 1)
 198                 tname = argv[1];
 199
 200         /*
 201          * The following is a work around for vhangup interactions
 202          * which cause great problems getting window systems started.
 203          * If the tty line is "-", we do the old style getty presuming
 204          * that the file descriptors are already set up for us.
 205          * J. Gettys - MIT Project Athena.
 206          */
 207         if (argc <= 2 || strcmp(argv[2], "-") == 0)
 208             strcpy(ttyn, ttyname(STDIN_FILENO));
 209         else {
 210             strcpy(ttyn, dev);
 211             strncat(ttyn, argv[2], sizeof(ttyn)-sizeof(dev));
 212             if (strcmp(argv[0], "+") != 0) {
 213                 chown(ttyn, 0, 0);
 214                 chmod(ttyn, 0600);
 215                 revoke(ttyn);
 216
 217                 /*
 218                  * Do the first scan through gettytab.
 219                  * Terminal mode parameters will be wrong until
 220                  * defttymode() called, but they're irrelevant for
 221                  * the initial setup of the terminal device.
 222                  */
 223                 dogettytab();
 224
 225                 /*
 226                  * Init or answer modem sequence has been specified.
 227                  */
 228                 if (IC || AC) {
 229                         if (!opentty(ttyn, O_RDWR|O_NONBLOCK))
 230                                 exit(1);
 231                         defttymode();
 232                         setttymode(1);
 233                 }
 234
 235                 if (IC) {
 236                         if (getty_chat(IC, CT, DC) > 0) {
 237                                 syslog(LOG_ERR, "modem init problem on %s", ttyn);
 238                                 (void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
 239                                 exit(1);
 240                         }
 241                 }
 242
 243                 if (AC) {
 244                         fd_set rfds;
 245                         struct timeval to;
 246                         int i;
 247
 248                         FD_ZERO(&rfds);
 249                         FD_SET(0, &rfds);
 250                         to.tv_sec = RT;
 251                         to.tv_usec = 0;
 252                         i = select(32, &rfds, NULL, NULL, RT ? &to : NULL);
 253                         if (i < 0) {
 254                                 syslog(LOG_ERR, "select %s: %m", ttyn);
 255                         } else if (i == 0) {
 256                                 syslog(LOG_NOTICE, "recycle tty %s", ttyn);
 257                                 (void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
 258                                 exit(0);  /* recycle for init */
 259                         }
 260                         i = getty_chat(AC, CT, DC);
 261                         if (i > 0) {
 262                                 syslog(LOG_ERR, "modem answer problem on %s", ttyn);
 263                                 (void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
 264                                 exit(1);
 265                         }
 266                 } else { /* maybe blocking open */
 267                         if (!opentty(ttyn, O_RDWR | (NC ? O_NONBLOCK : 0 )))
 268                                 exit(1);
 269                 }
 270             }
 271         }
 272
 273         defttymode();
 274         for (;;) {
 275
 276                 /*
 277                  * if a delay was specified then sleep for that
 278                  * number of seconds before writing the initial prompt
 279                  */
 280                 if (first_sleep && DE) {
 281                     sleep(DE);
 282                     /* remove any noise */
 283                     (void)tcflush(STDIN_FILENO, TCIOFLUSH);
 284                 }
 285                 first_sleep = 0;
 286
 287                 setttymode(0);
 288                 if (AB) {
 289                         tname = autobaud();
 290                         dogettytab();
 291                         continue;
 292                 }
 293                 if (PS) {
 294                         tname = portselector();
 295                         dogettytab();
 296                         continue;
 297                 }
 298                 if (CL && *CL)
 299                         putpad(CL);
 300                 edithost(HE);
 301
 302                 /* if this is the first time through this, and an
 303                    issue file has been given, then send it */
 304                 if (first_time && IF) {
 305                         int fd;
 306
 307                         if ((fd = open(IF, O_RDONLY)) != -1) {
 308                                 char * cp;
 309
 310                                 while ((cp = get_line(fd)) != NULL) {
 311                                           putf(cp);
 312                                 }
 313                                 close(fd);
 314                         }
 315                 }
 316                 first_time = 0;
 317
 318                 if (IMP && *IMP && !(PL && PP))
 319                         system(IMP);
 320                 if (IM && *IM && !(PL && PP))
 321                         putf(IM);
 322                 if (setjmp(timeout)) {
 323                         cfsetispeed(&tmode, B0);
 324                         cfsetospeed(&tmode, B0);
 325                         (void)tcsetattr(STDIN_FILENO, TCSANOW, &tmode);
 326                         exit(1);
 327                 }
 328                 if (TO) {
 329                         signal(SIGALRM, dingdong);
 330                         alarm(TO);
 331                 }
 332
 333                 rval = 0;
 334                 if (AL) {
 335                         const char *p = AL;
 336                         char *q = name;
 337
 338                         while (*p && q < &name[sizeof name - 1]) {
 339                                 if (isupper(*p))
 340                                         upper = 1;
 341                                 else if (islower(*p))
 342                                         lower = 1;
 343                                 else if (isdigit(*p))
 344                                         digit = 1;
 345                                 *q++ = *p++;
 346                         }
 347                 } else if (!(PL && PP))
 348                         rval = getname();
 349                 if (rval == 2 || (PL && PP)) {
 350                         oflush();
 351                         alarm(0);
 352                         limit.rlim_max = RLIM_INFINITY;
 353                         limit.rlim_cur = RLIM_INFINITY;
 354                         (void)setrlimit(RLIMIT_CPU, &limit);
 355                         execle(PP, "ppplogin", ttyn, NULL, env);
 356                         syslog(LOG_ERR, "%s: %m", PP);
 357                         exit(1);
 358                 } else if (rval || AL) {
 359                         int i;
 360
 361                         oflush();
 362                         alarm(0);
 363                         signal(SIGALRM, SIG_DFL);
 364                         if (name[0] == '\0')
 365                                 continue;
 366                         if (name[0] == '-') {
 367                                 puts("user names may not start with '-'.");
 368                                 continue;
 369                         }
 370                         if (!(upper || lower || digit)) {
 371                                 if (AL) {
 372                                         syslog(LOG_ERR,
 373                                             "invalid auto-login name: %s", AL);
 374                                         exit(1);
 375                                 } else
 376                                         continue;
 377                         }
 378                         set_flags(2);
 379                         if (crmod) {
 380                                 tmode.c_iflag |= ICRNL;
 381                                 tmode.c_oflag |= ONLCR;
 382                         }
 383 #if REALLY_OLD_TTYS
 384                         if (upper || UC)
 385                                 tmode.sg_flags |= LCASE;
 386                         if (lower || LC)
 387                                 tmode.sg_flags &= ~LCASE;
 388 #endif
 389                         if (tcsetattr(STDIN_FILENO, TCSANOW, &tmode) < 0) {
 390                                 syslog(LOG_ERR, "tcsetattr %s: %m", ttyn);
 391                                 exit(1);
 392                         }
 393                         signal(SIGINT, SIG_DFL);
 394                         for (i = 0; environ[i] != NULL; i++)
 395                                 env[i] = environ[i];
 396                         makeenv(&env[i]);
 397
 398                         limit.rlim_max = RLIM_INFINITY;
 399                         limit.rlim_cur = RLIM_INFINITY;
 400                         (void)setrlimit(RLIMIT_CPU, &limit);
 401                         execle(LO, "login", AL ? "-fp" : "-p", name,
 402                             NULL, env);
 403                         syslog(LOG_ERR, "%s: %m", LO);
 404                         exit(1);
 405                 }
 406                 alarm(0);
 407                 signal(SIGALRM, SIG_DFL);
 408                 signal(SIGINT, SIG_IGN);
 409                 if (NX && *NX) {
 410                         tname = NX;
 411                         dogettytab();
 412                 }
 413         }
 414 }
 415
 416 static int
 417 opentty(const char *tty, int flags)
 418 {
 419         int failopenlogged = 0, i, saved_errno;
 420
 421         while ((i = open(tty, flags)) == -1)
 422         {
 423                 saved_errno = errno;
 424                 if (!failopenlogged) {
 425                         syslog(LOG_ERR, "open %s: %m", tty);
 426                         failopenlogged = 1;
 427                 }
 428                 if (saved_errno == ENOENT)
 429                         return 0;
 430                 sleep(60);
 431         }
 432         if (login_tty(i) < 0) {
 433                 if (daemon(0,0) < 0) {
 434                         syslog(LOG_ERR,"daemon: %m");
 435                         close(i);
 436                         return 0;
 437                 }
 438                 if (login_tty(i) < 0) {
 439                         syslog(LOG_ERR, "login_tty %s: %m", tty);
 440                         close(i);
 441                         return 0;
 442                 }
 443         }
 444         return 1;
 445 }
 446
 447 static void
 448 defttymode(void)
 449 {
 450         struct termios def;
 451
 452         /* Start with default tty settings. */
 453         if (tcgetattr(STDIN_FILENO, &tmode) < 0) {
 454                 syslog(LOG_ERR, "tcgetattr %s: %m", ttyn);
 455                 exit(1);
 456         }
 457         omode = tmode; /* fill c_cc for dogettytab() */
 458         dogettytab();
 459         /*
 460          * Don't rely on the driver too much, and initialize crucial
 461          * things according to <sys/ttydefaults.h>.  Avoid clobbering
 462          * the c_cc[] settings however, the console drivers might wish
 463          * to leave their idea of the preferred VERASE key value
 464          * there.
 465          */
 466         cfmakesane(&def);
 467         tmode.c_iflag = def.c_iflag;
 468         tmode.c_oflag = def.c_oflag;
 469         tmode.c_lflag = def.c_lflag;
 470         tmode.c_cflag = def.c_cflag;
 471         if (NC)
 472                 tmode.c_cflag |= CLOCAL;
 473         omode = tmode;
 474 }
 475
 476 static void
 477 setttymode(int raw)
 478 {
 479         int off = 0;
 480
 481         (void)tcflush(STDIN_FILENO, TCIOFLUSH); /* clear out the crap */
 482         ioctl(STDIN_FILENO, FIONBIO, &off);     /* turn off non-blocking mode */
 483         ioctl(STDIN_FILENO, FIOASYNC, &off);    /* ditto for async mode */
 484
 485         if (IS)
 486                 cfsetispeed(&tmode, speed(IS));
 487         else if (SP)
 488                 cfsetispeed(&tmode, speed(SP));
 489         if (OS)
 490                 cfsetospeed(&tmode, speed(OS));
 491         else if (SP)
 492                 cfsetospeed(&tmode, speed(SP));
 493         set_flags(0);
 494         setchars();
 495         if (raw)
 496                 cfmakeraw(&tmode);
 497         if (tcsetattr(STDIN_FILENO, TCSANOW, &tmode) < 0) {
 498                 syslog(LOG_ERR, "tcsetattr %s: %m", ttyn);
 499                 exit(1);
 500         }
 501 }
 502
 503
 504 static int
 505 getname(void)
 506 {
 507         int c;
 508         char *np;
 509         unsigned char cs;
 510         int ppp_state = 0;
 511         int ppp_connection = 0;
 512
 513         /*
 514          * Interrupt may happen if we use CBREAK mode
 515          */
 516         if (setjmp(intrupt)) {
 517                 signal(SIGINT, SIG_IGN);
 518                 return (0);
 519         }
 520         signal(SIGINT, interrupt);
 521         set_flags(1);
 522         prompt();
 523         oflush();
 524         if (PF > 0) {
 525                 sleep(PF);
 526                 PF = 0;
 527         }
 528         if (tcsetattr(STDIN_FILENO, TCSANOW, &tmode) < 0) {
 529                 syslog(LOG_ERR, "%s: %m", ttyn);
 530                 exit(1);
 531         }
 532         crmod = digit = lower = upper = 0;
 533         np = name;
 534         for (;;) {
 535                 oflush();
 536                 if (read(STDIN_FILENO, &cs, 1) <= 0)
 537                         exit(0);
 538                 if ((c = cs&0177) == 0)
 539                         return (0);
 540
 541                 /* PPP detection state machine..
 542                    Look for sequences:
 543                    PPP_FRAME, PPP_STATION, PPP_ESCAPE, PPP_CONTROL_ESCAPED or
 544                    PPP_FRAME, PPP_STATION, PPP_CONTROL (deviant from RFC)
 545                    See RFC1662.
 546                    Derived from code from Michael Hancock, <michaelh@cet.co.jp>
 547                    and Erik 'PPP' Olson, <eriko@wrq.com>
 548                  */
 549
 550                 if (PP && (cs == PPP_FRAME)) {
 551                         ppp_state = 1;
 552                 } else if (ppp_state == 1 && cs == PPP_STATION) {
 553                         ppp_state = 2;
 554                 } else if (ppp_state == 2 && cs == PPP_ESCAPE) {
 555                         ppp_state = 3;
 556                 } else if ((ppp_state == 2 && cs == PPP_CONTROL)
 557                         || (ppp_state == 3 && cs == PPP_CONTROL_ESCAPED)) {
 558                         ppp_state = 4;
 559                 } else if (ppp_state == 4 && cs == PPP_LCP_HI) {
 560                         ppp_state = 5;
 561                 } else if (ppp_state == 5 && cs == PPP_LCP_LOW) {
 562                         ppp_connection = 1;
 563                         break;
 564                 } else {
 565                         ppp_state = 0;
 566                 }
 567
 568                 if (c == EOT || c == CTRL('d'))
 569                         exit(0);
 570                 if (c == '\r' || c == '\n' || np >= &name[sizeof name-1]) {
 571                         putf("\r\n");
 572                         break;
 573                 }
 574                 if (islower(c))
 575                         lower = 1;
 576                 else if (isupper(c))
 577                         upper = 1;
 578                 else if (c == ERASE || c == '\b' || c == 0177) {
 579                         if (np > name) {
 580                                 np--;
 581                                 if (cfgetospeed(&tmode) >= 1200)
 582                                         puts("\b \b");
 583                                 else
 584                                         putchr(cs);
 585                         }
 586                         continue;
 587                 } else if (c == KILL || c == CTRL('u')) {
 588                         putchr('\r');
 589                         if (cfgetospeed(&tmode) < 1200)
 590                                 putchr('\n');
 591                         /* this is the way they do it down under ... */
 592                         else if (np > name)
 593                                 puts("                                     \r");
 594                         prompt();
 595                         digit = lower = upper = 0;
 596                         np = name;
 597                         continue;
 598                 } else if (isdigit(c))
 599                         digit = 1;
 600                 if (IG && (c <= ' ' || c > 0176))
 601                         continue;
 602                 *np++ = c;
 603                 putchr(cs);
 604         }
 605         signal(SIGINT, SIG_IGN);
 606         *np = 0;
 607         if (c == '\r')
 608                 crmod = 1;
 609         if ((upper && !lower && !LC) || UC)
 610                 for (np = name; *np; np++)
 611                         if (isupper(*np))
 612                                 *np = tolower(*np);
 613         return (1 + ppp_connection);
 614 }
 615
 616 static void
 617 putpad(const char *s)
 618 {
 619         int pad = 0;
 620         speed_t ospeed = cfgetospeed(&tmode);
 621
 622         if (isdigit(*s)) {
 623                 while (isdigit(*s)) {
 624                         pad *= 10;
 625                         pad += *s++ - '0';
 626                 }
 627                 pad *= 10;
 628                 if (*s == '.' && isdigit(s[1])) {
 629                         pad += s[1] - '0';
 630                         s += 2;
 631                 }
 632         }
 633
 634         puts(s);
 635         /*
 636          * If no delay needed, or output speed is
 637          * not comprehensible, then don't try to delay.
 638          */
 639         if (pad == 0 || ospeed <= 0)
 640                 return;
 641
 642         /*
 643          * Round up by a half a character frame, and then do the delay.
 644          * Too bad there are no user program accessible programmed delays.
 645          * Transmitting pad characters slows many terminals down and also
 646          * loads the system.
 647          */
 648         pad = (pad * ospeed + 50000) / 100000;
 649         while (pad--)
 650                 putchr(*PC);
 651 }
 652
 653 static void
 654 puts(const char *s)
 655 {
 656         while (*s)
 657                 putchr(*s++);
 658 }
 659
 660 static char     outbuf[OBUFSIZ];
 661 static int      obufcnt = 0;
 662
 663 static void
 664 putchr(int cc)
 665 {
 666         char c;
 667
 668         c = cc;
 669         if (!NP) {
 670                 c |= partab[c&0177] & 0200;
 671                 if (OP)
 672                         c ^= 0200;
 673         }
 674         if (!UB) {
 675                 outbuf[obufcnt++] = c;
 676                 if (obufcnt >= OBUFSIZ)
 677                         oflush();
 678         } else
 679                 write(STDOUT_FILENO, &c, 1);
 680 }
 681
 682 static void
 683 oflush(void)
 684 {
 685         if (obufcnt)
 686                 write(STDOUT_FILENO, outbuf, obufcnt);
 687         obufcnt = 0;
 688 }
 689
 690 static void
 691 prompt(void)
 692 {
 693
 694         putf(LM);
 695         if (CO)
 696                 putchr('\n');
 697 }
 698
 699
 700 static char *
 701 get_line(int fd)
 702 {
 703         size_t i = 0;
 704         static char linebuf[512];
 705
 706         /*
 707          * This is certainly slow, but it avoids having to include
 708          * stdio.h unnecessarily. Issue files should be small anyway.
 709          */
 710         while (i < (sizeof linebuf - 3) && read(fd, linebuf+i, 1)==1) {
 711                 if (linebuf[i] == '\n') {
 712                         /* Don't rely on newline mode, assume raw */
 713                         linebuf[i++] = '\r';
 714                         linebuf[i++] = '\n';
 715                         linebuf[i] = '\0';
 716                         return linebuf;
 717                 }
 718                 ++i;
 719         }
 720         linebuf[i] = '\0';
 721         return i ? linebuf : 0;
 722 }
 723
 724 static void
 725 putf(const char *cp)
 726 {
 727         time_t t;
 728         char *slash, db[100];
 729
 730         static struct utsname kerninfo;
 731
 732         if (!*kerninfo.sysname)
 733                 uname(&kerninfo);
 734
 735         while (*cp) {
 736                 if (*cp != '%') {
 737                         putchr(*cp++);
 738                         continue;
 739                 }
 740                 switch (*++cp) {
 741
 742                 case 't':
 743                         slash = strrchr(ttyn, '/');
 744                         if (slash == NULL)
 745                                 puts(ttyn);
 746                         else
 747                                 puts(&slash[1]);
 748                         break;
 749
 750                 case 'h':
 751                         puts(editedhost);
 752                         break;
 753
 754                 case 'd': {
 755                         t = (time_t)0;
 756                         (void)time(&t);
 757                         if (Lo)
 758                                 (void)setlocale(LC_TIME, Lo);
 759                         (void)strftime(db, sizeof(db), DF, localtime(&t));
 760                         puts(db);
 761                         break;
 762
 763                 case 's':
 764                         puts(kerninfo.sysname);
 765                         break;
 766
 767                 case 'm':
 768                         puts(kerninfo.machine);
 769                         break;
 770
 771                 case 'r':
 772                         puts(kerninfo.release);
 773                         break;
 774
 775                 case 'v':
 776                         puts(kerninfo.version);
 777                         break;
 778                 }
 779
 780                 case '%':
 781                         putchr('%');
 782                         break;
 783                 }
 784                 cp++;
 785         }
 786 }
 787
 788 /*
 789  * Read a gettytab database entry and perform necessary quirks.
 790  */
 791 static void
 792 dogettytab(void)
 793 {
 794         /* Read the database entry. */
 795         gettable(tname, tabent);
 796
 797         /*
 798          * Avoid inheriting the parity values from the default entry
 799          * if any of them is set in the current entry.
 800          * Mixing different parity settings is unreasonable.
 801          */
 802         if (OPset || EPset || APset || NPset)
 803                 OPset = EPset = APset = NPset = 1;
 804
 805         /* Fill in default values for unset capabilities. */
 806         setdefaults();
 807 }