appl/telnet/telnetd/telnetd.c

   1 /*
   2  * Copyright (c) 1989, 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
  34 #include "telnetd.h"
  35
  36 RCSID("$Id$");
  37
  38 #ifdef _SC_CRAY_SECURE_SYS
  39 #include <sys/sysv.h>
  40 #include <sys/secdev.h>
  41 #include <sys/secparm.h>
  42 #include <sys/usrv.h>
  43 int     secflag;
  44 char    tty_dev[16];
  45 struct  secdev dv;
  46 struct  sysv sysv;
  47 struct  socksec ss;
  48 #endif  /* _SC_CRAY_SECURE_SYS */
  49
  50 #ifdef AUTHENTICATION
  51 int     auth_level = 0;
  52 #endif
  53
  54 extern  int utmp_len;
  55 int     registerd_host_only = 0;
  56
  57 #undef NOERROR
  58
  59 #ifdef  STREAMSPTY
  60 # include <stropts.h>
  61 # include <termios.h>
  62 #ifdef HAVE_SYS_UIO_H
  63 #include <sys/uio.h>
  64 #endif /* HAVE_SYS_UIO_H */
  65 #ifdef HAVE_SYS_STREAM_H
  66 #include <sys/stream.h>
  67 #endif
  68
  69 #ifdef _AIX
  70 #include <sys/termio.h>
  71 #endif
  72 # ifdef HAVE_SYS_STRTTY_H
  73 # include <sys/strtty.h>
  74 # endif
  75 # ifdef HAVE_SYS_STR_TTY_H
  76 # include <sys/str_tty.h>
  77 # endif
  78 /* make sure we don't get the bsd version */
  79 /* what is this here for? solaris? /joda */
  80 # ifdef HAVE_SYS_TTY_H
  81 # include "/usr/include/sys/tty.h"
  82 # endif
  83 # ifdef HAVE_SYS_PTYVAR_H
  84 # include <sys/ptyvar.h>
  85 # endif
  86
  87 /*
  88  * Because of the way ptyibuf is used with streams messages, we need
  89  * ptyibuf+1 to be on a full-word boundary.  The following wierdness
  90  * is simply to make that happen.
  91  */
  92 long    ptyibufbuf[BUFSIZ/sizeof(long)+1];
  93 char    *ptyibuf = ((char *)&ptyibufbuf[1])-1;
  94 char    *ptyip = ((char *)&ptyibufbuf[1])-1;
  95 char    ptyibuf2[BUFSIZ];
  96 unsigned char ctlbuf[BUFSIZ];
  97 struct  strbuf strbufc, strbufd;
  98
  99 int readstream(int, char*, int);
 100
 101 #else   /* ! STREAMPTY */
 102
 103 /*
 104  * I/O data buffers,
 105  * pointers, and counters.
 106  */
 107 char    ptyibuf[BUFSIZ], *ptyip = ptyibuf;
 108 char    ptyibuf2[BUFSIZ];
 109
 110 #endif /* ! STREAMPTY */
 111
 112 int     hostinfo = 1;                   /* do we print login banner? */
 113
 114 #ifdef  _CRAY
 115 extern int      newmap; /* nonzero if \n maps to ^M^J */
 116 int     lowpty = 0, highpty;    /* low, high pty numbers */
 117 #endif /* CRAY */
 118
 119 int debug = 0;
 120 int keepalive = 1;
 121 char *progname;
 122
 123 static void usage (void);
 124
 125 /*
 126  * The string to pass to getopt().  We do it this way so
 127  * that only the actual options that we support will be
 128  * passed off to getopt().
 129  */
 130 char valid_opts[] = "Bd:hklnS:u:UL:y"
 131 #ifdef AUTHENTICATION
 132                     "a:X:z"
 133 #endif
 134 #ifdef DIAGNOSTICS
 135                     "D:"
 136 #endif
 137 #ifdef _CRAY
 138                     "r:"
 139 #endif
 140                     ;
 141
 142 static void doit(struct sockaddr*, int);
 143
 144 #ifdef ENCRYPTION
 145 extern int des_check_key;
 146 #endif
 147
 148 int
 149 main(int argc, char **argv)
 150 {
 151     struct sockaddr_storage __ss;
 152     struct sockaddr *sa = (struct sockaddr *)&__ss;
 153     int on = 1;
 154     socklen_t sa_size;
 155     int ch;
 156 #if     defined(IPPROTO_IP) && defined(IP_TOS)
 157     int tos = -1;
 158 #endif
 159 #ifdef ENCRYPTION
 160     des_check_key = 1;  /* Kludge for Mac NCSA telnet 2.6 /bg */
 161 #endif
 162     pfrontp = pbackp = ptyobuf;
 163     netip = netibuf;
 164     nfrontp = nbackp = netobuf;
 165
 166     setprogname(argv[0]);
 167
 168     progname = *argv;
 169 #ifdef ENCRYPTION
 170     nclearto = 0;
 171 #endif
 172
 173 #ifdef _CRAY
 174     /*
 175      * Get number of pty's before trying to process options,
 176      * which may include changing pty range.
 177      */
 178     highpty = getnpty();
 179 #endif /* CRAY */
 180
 181     if (argc == 2 && strcmp(argv[1], "--version") == 0) {
 182         print_version(NULL);
 183         exit(0);
 184     }
 185
 186     while ((ch = getopt(argc, argv, valid_opts)) != -1) {
 187         switch(ch) {
 188
 189 #ifdef  AUTHENTICATION
 190         case 'a':
 191             /*
 192              * Check for required authentication level
 193              */
 194             if (strcmp(optarg, "debug") == 0) {
 195                 auth_debug_mode = 1;
 196             } else if (strcasecmp(optarg, "none") == 0) {
 197                 auth_level = 0;
 198             } else if (strcasecmp(optarg, "otp") == 0) {
 199                 auth_level = 0;
 200                 require_otp = 1;
 201             } else if (strcasecmp(optarg, "other") == 0) {
 202                 auth_level = AUTH_OTHER;
 203             } else if (strcasecmp(optarg, "user") == 0) {
 204                 auth_level = AUTH_USER;
 205             } else if (strcasecmp(optarg, "valid") == 0) {
 206                 auth_level = AUTH_VALID;
 207             } else if (strcasecmp(optarg, "off") == 0) {
 208                 /*
 209                  * This hack turns off authentication
 210                  */
 211                 auth_level = -1;
 212             } else {
 213                 fprintf(stderr,
 214                         "telnetd: unknown authorization level for -a\n");
 215             }
 216             break;
 217 #endif  /* AUTHENTICATION */
 218
 219         case 'B': /* BFTP mode is not supported any more */
 220             break;
 221         case 'd':
 222             if (strcmp(optarg, "ebug") == 0) {
 223                 debug++;
 224                 break;
 225             }
 226             usage();
 227             /* NOTREACHED */
 228             break;
 229
 230 #ifdef DIAGNOSTICS
 231         case 'D':
 232             /*
 233              * Check for desired diagnostics capabilities.
 234              */
 235             if (!strcmp(optarg, "report")) {
 236                 diagnostic |= TD_REPORT|TD_OPTIONS;
 237             } else if (!strcmp(optarg, "exercise")) {
 238                 diagnostic |= TD_EXERCISE;
 239             } else if (!strcmp(optarg, "netdata")) {
 240                 diagnostic |= TD_NETDATA;
 241             } else if (!strcmp(optarg, "ptydata")) {
 242                 diagnostic |= TD_PTYDATA;
 243             } else if (!strcmp(optarg, "options")) {
 244                 diagnostic |= TD_OPTIONS;
 245             } else {
 246                 usage();
 247                 /* NOT REACHED */
 248             }
 249             break;
 250 #endif /* DIAGNOSTICS */
 251
 252
 253         case 'h':
 254             hostinfo = 0;
 255             break;
 256
 257         case 'k': /* Linemode is not supported any more */
 258         case 'l':
 259             break;
 260
 261         case 'n':
 262             keepalive = 0;
 263             break;
 264
 265 #ifdef _CRAY
 266         case 'r':
 267             {
 268                 char *strchr();
 269                 char *c;
 270
 271                 /*
 272                  * Allow the specification of alterations
 273                  * to the pty search range.  It is legal to
 274                  * specify only one, and not change the
 275                  * other from its default.
 276                  */
 277                 c = strchr(optarg, '-');
 278                 if (c) {
 279                     *c++ = '\0';
 280                     highpty = atoi(c);
 281                 }
 282                 if (*optarg != '\0')
 283                     lowpty = atoi(optarg);
 284                 if ((lowpty > highpty) || (lowpty < 0) ||
 285                     (highpty > 32767)) {
 286                     usage();
 287                     /* NOT REACHED */
 288                 }
 289                 break;
 290             }
 291 #endif  /* CRAY */
 292
 293         case 'S':
 294 #ifdef  HAVE_PARSETOS
 295             if ((tos = parsetos(optarg, "tcp")) < 0)
 296                 fprintf(stderr, "%s%s%s\n",
 297                         "telnetd: Bad TOS argument '", optarg,
 298                         "'; will try to use default TOS");
 299 #else
 300             fprintf(stderr, "%s%s\n", "TOS option unavailable; ",
 301                     "-S flag not supported\n");
 302 #endif
 303             break;
 304
 305         case 'u': {
 306             char *eptr;
 307
 308             utmp_len = strtol(optarg, &eptr, 0);
 309             if (optarg == eptr)
 310                 fprintf(stderr, "telnetd: unknown utmp len (%s)\n", optarg);
 311             break;
 312         }
 313
 314         case 'U':
 315             registerd_host_only = 1;
 316             break;
 317
 318 #ifdef  AUTHENTICATION
 319         case 'X':
 320             /*
 321              * Check for invalid authentication types
 322              */
 323             auth_disable_name(optarg);
 324             break;
 325 #endif
 326         case 'y':
 327             no_warn = 1;
 328             break;
 329 #ifdef AUTHENTICATION
 330         case 'z':
 331             log_unauth = 1;
 332             break;
 333
 334 #endif  /* AUTHENTICATION */
 335
 336         case 'L':
 337             new_login = optarg;
 338             break;
 339
 340         default:
 341             fprintf(stderr, "telnetd: %c: unknown option\n", ch);
 342             /* FALLTHROUGH */
 343         case '?':
 344             usage();
 345             /* NOTREACHED */
 346         }
 347     }
 348
 349     argc -= optind;
 350     argv += optind;
 351
 352     if (debug) {
 353         int port = 0;
 354         struct servent *sp;
 355
 356         if (argc > 1) {
 357             usage ();
 358         } else if (argc == 1) {
 359             sp = roken_getservbyname (*argv, "tcp");
 360             if (sp)
 361                 port = sp->s_port;
 362             else
 363                 port = htons(atoi(*argv));
 364         } else {
 365 #ifdef KRB5
 366             port = krb5_getportbyname (NULL, "telnet", "tcp", 23);
 367 #else
 368             port = k_getportbyname("telnet", "tcp", htons(23));
 369 #endif
 370         }
 371         mini_inetd (port);
 372     } else if (argc > 0) {
 373         usage();
 374         /* NOT REACHED */
 375     }
 376
 377 #ifdef _SC_CRAY_SECURE_SYS
 378     secflag = sysconf(_SC_CRAY_SECURE_SYS);
 379
 380     /*
 381      *  Get socket's security label
 382      */
 383     if (secflag)  {
 384         socklen_t szss = sizeof(ss);
 385         int sock_multi;
 386         socklen_t szi = sizeof(int);
 387
 388         memset(&dv, 0, sizeof(dv));
 389
 390         if (getsysv(&sysv, sizeof(struct sysv)) != 0)
 391             fatalperror(net, "getsysv");
 392
 393         /*
 394          *      Get socket security label and set device values
 395          *         {security label to be set on ttyp device}
 396          */
 397 #ifdef SO_SEC_MULTI                     /* 8.0 code */
 398         if ((getsockopt(0, SOL_SOCKET, SO_SECURITY,
 399                         (void *)&ss, &szss) < 0) ||
 400             (getsockopt(0, SOL_SOCKET, SO_SEC_MULTI,
 401                         (void *)&sock_multi, &szi) < 0))
 402             fatalperror(net, "getsockopt");
 403         else {
 404             dv.dv_actlvl = ss.ss_actlabel.lt_level;
 405             dv.dv_actcmp = ss.ss_actlabel.lt_compart;
 406             if (!sock_multi) {
 407                 dv.dv_minlvl = dv.dv_maxlvl = dv.dv_actlvl;
 408                 dv.dv_valcmp = dv.dv_actcmp;
 409             } else {
 410                 dv.dv_minlvl = ss.ss_minlabel.lt_level;
 411                 dv.dv_maxlvl = ss.ss_maxlabel.lt_level;
 412                 dv.dv_valcmp = ss.ss_maxlabel.lt_compart;
 413             }
 414             dv.dv_devflg = 0;
 415         }
 416 #else /* SO_SEC_MULTI */                /* 7.0 code */
 417         if (getsockopt(0, SOL_SOCKET, SO_SECURITY,
 418                        (void *)&ss, &szss) >= 0) {
 419             dv.dv_actlvl = ss.ss_slevel;
 420             dv.dv_actcmp = ss.ss_compart;
 421             dv.dv_minlvl = ss.ss_minlvl;
 422             dv.dv_maxlvl = ss.ss_maxlvl;
 423             dv.dv_valcmp = ss.ss_maxcmp;
 424         }
 425 #endif /* SO_SEC_MULTI */
 426     }
 427 #endif  /* _SC_CRAY_SECURE_SYS */
 428
 429     roken_openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
 430     sa_size = sizeof (__ss);
 431     if (getpeername(STDIN_FILENO, sa, &sa_size) < 0) {
 432         fprintf(stderr, "%s: ", progname);
 433         perror("getpeername");
 434         _exit(1);
 435     }
 436     if (keepalive &&
 437         setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE,
 438                    (void *)&on, sizeof (on)) < 0) {
 439         syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
 440     }
 441
 442 #if     defined(IPPROTO_IP) && defined(IP_TOS) && defined(HAVE_SETSOCKOPT)
 443     {
 444 # ifdef HAVE_GETTOSBYNAME
 445         struct tosent *tp;
 446         if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
 447             tos = tp->t_tos;
 448 # endif
 449         if (tos < 0)
 450             tos = 020;  /* Low Delay bit */
 451         if (tos
 452             && sa->sa_family == AF_INET
 453             && (setsockopt(STDIN_FILENO, IPPROTO_IP, IP_TOS,
 454                            (void *)&tos, sizeof(tos)) < 0)
 455             && (errno != ENOPROTOOPT) )
 456             syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
 457     }
 458 #endif  /* defined(IPPROTO_IP) && defined(IP_TOS) */
 459     net = STDIN_FILENO;
 460     doit(sa, sa_size);
 461     /* NOTREACHED */
 462     return 0;
 463 }  /* end of main */
 464
 465 static void
 466 usage(void)
 467 {
 468     fprintf(stderr, "Usage: telnetd");
 469 #ifdef  AUTHENTICATION
 470     fprintf(stderr, " [-a (debug|other|otp|user|valid|off|none)]\n\t");
 471 #endif
 472     fprintf(stderr, " [-debug]");
 473 #ifdef DIAGNOSTICS
 474     fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
 475 #endif
 476 #ifdef  AUTHENTICATION
 477     fprintf(stderr, " [-edebug]");
 478 #endif
 479     fprintf(stderr, " [-h]");
 480     fprintf(stderr, " [-L login]");
 481     fprintf(stderr, " [-n]");
 482 #ifdef  _CRAY
 483     fprintf(stderr, " [-r[lowpty]-[highpty]]");
 484 #endif
 485     fprintf(stderr, "\n\t");
 486 #ifdef  HAVE_GETTOSBYNAME
 487     fprintf(stderr, " [-S tos]");
 488 #endif
 489 #ifdef  AUTHENTICATION
 490     fprintf(stderr, " [-X auth-type] [-y] [-z]");
 491 #endif
 492     fprintf(stderr, " [-u utmp_hostname_length] [-U]");
 493     fprintf(stderr, " [port]\n");
 494     exit(1);
 495 }
 496
 497 /*
 498  * getterminaltype
 499  *
 500  *      Ask the other end to send along its terminal type and speed.
 501  * Output is the variable terminaltype filled in.
 502  */
 503 static unsigned char ttytype_sbbuf[] = {
 504     IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
 505 };
 506
 507 int
 508 getterminaltype(char *name, size_t name_sz)
 509 {
 510     int retval = -1;
 511
 512     settimer(baseline);
 513 #ifdef AUTHENTICATION
 514     /*
 515      * Handle the Authentication option before we do anything else.
 516      */
 517     send_do(TELOPT_AUTHENTICATION, 1);
 518     while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
 519         ttloop();
 520     if (his_state_is_will(TELOPT_AUTHENTICATION)) {
 521         retval = auth_wait(name, name_sz);
 522     }
 523 #endif
 524
 525 #ifdef ENCRYPTION
 526     send_will(TELOPT_ENCRYPT, 1);
 527     send_do(TELOPT_ENCRYPT, 1); /* esc@magic.fi */
 528 #endif
 529     send_do(TELOPT_TTYPE, 1);
 530     send_do(TELOPT_TSPEED, 1);
 531     send_do(TELOPT_XDISPLOC, 1);
 532     send_do(TELOPT_NEW_ENVIRON, 1);
 533     send_do(TELOPT_OLD_ENVIRON, 1);
 534     while (
 535 #ifdef ENCRYPTION
 536            his_do_dont_is_changing(TELOPT_ENCRYPT) ||
 537 #endif
 538            his_will_wont_is_changing(TELOPT_TTYPE) ||
 539            his_will_wont_is_changing(TELOPT_TSPEED) ||
 540            his_will_wont_is_changing(TELOPT_XDISPLOC) ||
 541            his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
 542            his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
 543         ttloop();
 544     }
 545 #ifdef ENCRYPTION
 546     /*
 547      * Wait for the negotiation of what type of encryption we can
 548      * send with.  If autoencrypt is not set, this will just return.
 549      */
 550     if (his_state_is_will(TELOPT_ENCRYPT)) {
 551         encrypt_wait();
 552     }
 553 #endif
 554     if (his_state_is_will(TELOPT_TSPEED)) {
 555         static unsigned char sb[] =
 556         { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
 557
 558         telnet_net_write (sb, sizeof sb);
 559         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 560     }
 561     if (his_state_is_will(TELOPT_XDISPLOC)) {
 562         static unsigned char sb[] =
 563         { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
 564
 565         telnet_net_write (sb, sizeof sb);
 566         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 567     }
 568     if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
 569         static unsigned char sb[] =
 570         { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
 571
 572         telnet_net_write (sb, sizeof sb);
 573         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 574     }
 575     else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
 576         static unsigned char sb[] =
 577         { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
 578
 579         telnet_net_write (sb, sizeof sb);
 580         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 581     }
 582     if (his_state_is_will(TELOPT_TTYPE)) {
 583
 584         telnet_net_write (ttytype_sbbuf, sizeof ttytype_sbbuf);
 585         DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
 586                                   sizeof ttytype_sbbuf - 2););
 587     }
 588     if (his_state_is_will(TELOPT_TSPEED)) {
 589         while (sequenceIs(tspeedsubopt, baseline))
 590             ttloop();
 591     }
 592     if (his_state_is_will(TELOPT_XDISPLOC)) {
 593         while (sequenceIs(xdisplocsubopt, baseline))
 594             ttloop();
 595     }
 596     if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
 597         while (sequenceIs(environsubopt, baseline))
 598             ttloop();
 599     }
 600     if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
 601         while (sequenceIs(oenvironsubopt, baseline))
 602             ttloop();
 603     }
 604     if (his_state_is_will(TELOPT_TTYPE)) {
 605         char first[256], last[256];
 606
 607         while (sequenceIs(ttypesubopt, baseline))
 608             ttloop();
 609
 610         /*
 611          * If the other side has already disabled the option, then
 612          * we have to just go with what we (might) have already gotten.
 613          */
 614         if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
 615             strlcpy(first, terminaltype, sizeof(first));
 616             for(;;) {
 617                 /*
 618                  * Save the unknown name, and request the next name.
 619                  */
 620                 strlcpy(last, terminaltype, sizeof(last));
 621                 _gettermname();
 622                 if (terminaltypeok(terminaltype))
 623                     break;
 624                 if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
 625                     his_state_is_wont(TELOPT_TTYPE)) {
 626                     /*
 627                      * We've hit the end.  If this is the same as
 628                      * the first name, just go with it.
 629                      */
 630                     if (strncmp(first, terminaltype, sizeof(first)) == 0)
 631                         break;
 632                     /*
 633                      * Get the terminal name one more time, so that
 634                      * RFC1091 compliant telnets will cycle back to
 635                      * the start of the list.
 636                      */
 637                     _gettermname();
 638                     if (strncmp(first, terminaltype, sizeof(first)) != 0)
 639                         strlcpy(terminaltype, first, sizeof(terminaltype));
 640                     break;
 641                 }
 642             }
 643         }
 644     }
 645     return(retval);
 646 }  /* end of getterminaltype */
 647
 648 void
 649 _gettermname(void)
 650 {
 651     /*
 652      * If the client turned off the option,
 653      * we can't send another request, so we
 654      * just return.
 655      */
 656     if (his_state_is_wont(TELOPT_TTYPE))
 657         return;
 658     settimer(baseline);
 659     telnet_net_write (ttytype_sbbuf, sizeof ttytype_sbbuf);
 660     DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
 661                               sizeof ttytype_sbbuf - 2););
 662     while (sequenceIs(ttypesubopt, baseline))
 663         ttloop();
 664 }
 665
 666 int
 667 terminaltypeok(char *s)
 668 {
 669     return 1;
 670 }
 671
 672
 673 char host_name[MaxHostNameLen];
 674 char remote_host_name[MaxHostNameLen];
 675 char remote_utmp_name[MaxHostNameLen];
 676
 677 /*
 678  * Get a pty, scan input lines.
 679  */
 680 static void
 681 doit(struct sockaddr *who, int who_len)
 682 {
 683     int level;
 684     int ptynum;
 685     char user_name[256];
 686     int error;
 687
 688     /*
 689      * Find an available pty to use.
 690      */
 691     ourpty = getpty(&ptynum);
 692     if (ourpty < 0)
 693         fatal(net, "All network ports in use");
 694
 695 #ifdef _SC_CRAY_SECURE_SYS
 696     /*
 697      *  set ttyp line security label
 698      */
 699     if (secflag) {
 700         char slave_dev[16];
 701
 702         snprintf(tty_dev, sizeof(tty_dev), "/dev/pty/%03d", ptynum);
 703         if (setdevs(tty_dev, &dv) < 0)
 704             fatal(net, "cannot set pty security");
 705         snprintf(slave_dev, sizeof(slave_dev), "/dev/ttyp%03d", ptynum);
 706         if (setdevs(slave_dev, &dv) < 0)
 707             fatal(net, "cannot set tty security");
 708     }
 709 #endif  /* _SC_CRAY_SECURE_SYS */
 710
 711     error = getnameinfo_verified (who, who_len,
 712                                   remote_host_name,
 713                                   sizeof(remote_host_name),
 714                                   NULL, 0,
 715                                   registerd_host_only ? NI_NAMEREQD : 0);
 716     if (error)
 717         fatal(net, "Couldn't resolve your address into a host name.\r\n\
 718 Please contact your net administrator");
 719
 720     gethostname(host_name, sizeof (host_name));
 721
 722     strlcpy (remote_utmp_name, remote_host_name, sizeof(remote_utmp_name));
 723
 724     /* Only trim if too long (and possible) */
 725     if (strlen(remote_utmp_name) > utmp_len) {
 726         char *domain = strchr(host_name, '.');
 727         char *p = strchr(remote_utmp_name, '.');
 728         if (domain != NULL && p != NULL && (strcmp(p, domain) == 0))
 729             *p = '\0'; /* remove domain part */
 730     }
 731
 732     /*
 733      * If hostname still doesn't fit utmp, use ipaddr.
 734      */
 735     if (strlen(remote_utmp_name) > utmp_len) {
 736         error = getnameinfo (who, who_len,
 737                              remote_utmp_name,
 738                              sizeof(remote_utmp_name),
 739                              NULL, 0,
 740                              NI_NUMERICHOST);
 741         if (error)
 742             fatal(net, "Couldn't get numeric address\r\n");
 743     }
 744
 745 #ifdef AUTHENTICATION
 746     auth_encrypt_init(host_name, remote_host_name, "TELNETD", 1);
 747 #endif
 748
 749     init_env();
 750     /*
 751      * get terminal type.
 752      */
 753     *user_name = 0;
 754     level = getterminaltype(user_name, sizeof(user_name));
 755     esetenv("TERM", terminaltype[0] ? terminaltype : "network", 1);
 756
 757 #ifdef _SC_CRAY_SECURE_SYS
 758     if (secflag) {
 759         if (setulvl(dv.dv_actlvl) < 0)
 760             fatal(net,"cannot setulvl()");
 761         if (setucmp(dv.dv_actcmp) < 0)
 762             fatal(net, "cannot setucmp()");
 763     }
 764 #endif  /* _SC_CRAY_SECURE_SYS */
 765
 766     /* begin server processing */
 767     my_telnet(net, ourpty, remote_host_name, remote_utmp_name,
 768               level, user_name);
 769     /*NOTREACHED*/
 770 }  /* end of doit */
 771
 772 /* output contents of /etc/issue.net, or /etc/issue */
 773 static void
 774 show_issue(void)
 775 {
 776     FILE *f;
 777     char buf[128];
 778     f = fopen(SYSCONFDIR "/issue.net", "r");
 779     if(f == NULL)
 780         f = fopen(SYSCONFDIR "/issue", "r");
 781     if(f){
 782         while(fgets(buf, sizeof(buf)-2, f)){
 783             strcpy(buf + strcspn(buf, "\r\n"), "\r\n");
 784             writenet((unsigned char*)buf, strlen(buf));
 785         }
 786         fclose(f);
 787     }
 788 }
 789
 790 /*
 791  * Main loop.  Select from pty and network, and
 792  * hand data to telnet receiver finite state machine.
 793  */
 794 void
 795 my_telnet(int f, int p, const char *host, const char *utmp_host,
 796           int level, char *autoname)
 797 {
 798     int on = 1;
 799     char *he;
 800     char *IM;
 801     int nfd;
 802     int startslave_called = 0;
 803     time_t timeout;
 804
 805     /*
 806      * Initialize the slc mapping table.
 807      */
 808     get_slc_defaults();
 809
 810     /*
 811      * Do some tests where it is desireable to wait for a response.
 812      * Rather than doing them slowly, one at a time, do them all
 813      * at once.
 814      */
 815     if (my_state_is_wont(TELOPT_SGA))
 816         send_will(TELOPT_SGA, 1);
 817     /*
 818      * Is the client side a 4.2 (NOT 4.3) system?  We need to know this
 819      * because 4.2 clients are unable to deal with TCP urgent data.
 820      *
 821      * To find out, we send out a "DO ECHO".  If the remote system
 822      * answers "WILL ECHO" it is probably a 4.2 client, and we note
 823      * that fact ("WILL ECHO" ==> that the client will echo what
 824      * WE, the server, sends it; it does NOT mean that the client will
 825      * echo the terminal input).
 826      */
 827     send_do(TELOPT_ECHO, 1);
 828
 829     /*
 830      * Send along a couple of other options that we wish to negotiate.
 831      */
 832     send_do(TELOPT_NAWS, 1);
 833     send_will(TELOPT_STATUS, 1);
 834     flowmode = 1;               /* default flow control state */
 835     restartany = -1;    /* uninitialized... */
 836     send_do(TELOPT_LFLOW, 1);
 837
 838     /*
 839      * Spin, waiting for a response from the DO ECHO.  However,
 840      * some REALLY DUMB telnets out there might not respond
 841      * to the DO ECHO.  So, we spin looking for NAWS, (most dumb
 842      * telnets so far seem to respond with WONT for a DO that
 843      * they don't understand...) because by the time we get the
 844      * response, it will already have processed the DO ECHO.
 845      * Kludge upon kludge.
 846      */
 847     while (his_will_wont_is_changing(TELOPT_NAWS))
 848         ttloop();
 849
 850     /*
 851      * But...
 852      * The client might have sent a WILL NAWS as part of its
 853      * startup code; if so, we'll be here before we get the
 854      * response to the DO ECHO.  We'll make the assumption
 855      * that any implementation that understands about NAWS
 856      * is a modern enough implementation that it will respond
 857      * to our DO ECHO request; hence we'll do another spin
 858      * waiting for the ECHO option to settle down, which is
 859      * what we wanted to do in the first place...
 860      */
 861     if (his_want_state_is_will(TELOPT_ECHO) &&
 862         his_state_is_will(TELOPT_NAWS)) {
 863         while (his_will_wont_is_changing(TELOPT_ECHO))
 864             ttloop();
 865     }
 866     /*
 867      * On the off chance that the telnet client is broken and does not
 868      * respond to the DO ECHO we sent, (after all, we did send the
 869      * DO NAWS negotiation after the DO ECHO, and we won't get here
 870      * until a response to the DO NAWS comes back) simulate the
 871      * receipt of a will echo.  This will also send a WONT ECHO
 872      * to the client, since we assume that the client failed to
 873      * respond because it believes that it is already in DO ECHO
 874      * mode, which we do not want.
 875      */
 876     if (his_want_state_is_will(TELOPT_ECHO)) {
 877         DIAG(TD_OPTIONS,
 878              {output_data("td: simulating recv\r\n");
 879              });
 880         willoption(TELOPT_ECHO);
 881     }
 882
 883     /*
 884      * Finally, to clean things up, we turn on our echo.  This
 885      * will break stupid 4.2 telnets out of local terminal echo.
 886      */
 887
 888     if (my_state_is_wont(TELOPT_ECHO))
 889         send_will(TELOPT_ECHO, 1);
 890
 891 #ifdef TIOCPKT
 892 #ifdef  STREAMSPTY
 893     if (!really_stream)
 894 #endif
 895         /*
 896          * Turn on packet mode
 897          */
 898         ioctl(p, TIOCPKT, (char *)&on);
 899 #endif
 900
 901
 902     /*
 903      * Call telrcv() once to pick up anything received during
 904      * terminal type negotiation, 4.2/4.3 determination, and
 905      * linemode negotiation.
 906      */
 907     telrcv();
 908
 909     ioctl(f, FIONBIO, (char *)&on);
 910     ioctl(p, FIONBIO, (char *)&on);
 911
 912 #if     defined(SO_OOBINLINE) && defined(HAVE_SETSOCKOPT)
 913     setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
 914                (void *)&on, sizeof on);
 915 #endif  /* defined(SO_OOBINLINE) */
 916
 917 #ifdef  SIGTSTP
 918     signal(SIGTSTP, SIG_IGN);
 919 #endif
 920 #ifdef  SIGTTOU
 921     /*
 922      * Ignoring SIGTTOU keeps the kernel from blocking us
 923      * in ttioct() in /sys/tty.c.
 924      */
 925     signal(SIGTTOU, SIG_IGN);
 926 #endif
 927
 928     signal(SIGCHLD, cleanup);
 929
 930 #ifdef  TIOCNOTTY
 931     {
 932         int t;
 933         t = open(_PATH_TTY, O_RDWR);
 934         if (t >= 0) {
 935             ioctl(t, TIOCNOTTY, (char *)0);
 936             close(t);
 937         }
 938     }
 939 #endif
 940
 941     show_issue();
 942     /*
 943      * Show banner that getty never gave.
 944      *
 945      * We put the banner in the pty input buffer.  This way, it
 946      * gets carriage return null processing, etc., just like all
 947      * other pty --> client data.
 948      */
 949
 950     if (getenv("USER"))
 951         hostinfo = 0;
 952
 953     IM = DEFAULT_IM;
 954     he = 0;
 955     edithost(he, host_name);
 956     if (hostinfo && *IM)
 957         putf(IM, ptyibuf2);
 958
 959     if (pcc)
 960         strncat(ptyibuf2, ptyip, pcc+1);
 961     ptyip = ptyibuf2;
 962     pcc = strlen(ptyip);
 963
 964     DIAG(TD_REPORT, {
 965         output_data("td: Entering processing loop\r\n");
 966     });
 967
 968
 969     nfd = ((f > p) ? f : p) + 1;
 970     timeout = time(NULL) + 5;
 971     for (;;) {
 972         fd_set ibits, obits, xbits;
 973         int c;
 974
 975         /* wait for encryption to be turned on, but don't wait
 976            indefinitely */
 977         if(!startslave_called && (!encrypt_delay() || timeout > time(NULL))){
 978             startslave_called = 1;
 979             startslave(host, utmp_host, level, autoname);
 980         }
 981
 982         if (ncc < 0 && pcc < 0)
 983             break;
 984
 985         FD_ZERO(&ibits);
 986         FD_ZERO(&obits);
 987         FD_ZERO(&xbits);
 988
 989         if (f >= FD_SETSIZE
 990             || p >= FD_SETSIZE)
 991             fatal(net, "fd too large");
 992
 993         /*
 994          * Never look for input if there's still
 995          * stuff in the corresponding output buffer
 996          */
 997         if (nfrontp - nbackp || pcc > 0) {
 998             FD_SET(f, &obits);
 999         } else {
1000             FD_SET(p, &ibits);
1001         }
1002         if (pfrontp - pbackp || ncc > 0) {
1003             FD_SET(p, &obits);
1004         } else {
1005             FD_SET(f, &ibits);
1006         }
1007         if (!SYNCHing) {
1008             FD_SET(f, &xbits);
1009         }
1010         if ((c = select(nfd, &ibits, &obits, &xbits,
1011                         (struct timeval *)0)) < 1) {
1012             if (c == -1) {
1013                 if (errno == EINTR) {
1014                     continue;
1015                 }
1016             }
1017             sleep(5);
1018             continue;
1019         }
1020
1021         /*
1022          * Any urgent data?
1023          */
1024         if (FD_ISSET(net, &xbits)) {
1025             SYNCHing = 1;
1026         }
1027
1028         /*
1029          * Something to read from the network...
1030          */
1031         if (FD_ISSET(net, &ibits)) {
1032 #ifndef SO_OOBINLINE
1033             /*
1034              * In 4.2 (and 4.3 beta) systems, the
1035              * OOB indication and data handling in the kernel
1036              * is such that if two separate TCP Urgent requests
1037              * come in, one byte of TCP data will be overlaid.
1038              * This is fatal for Telnet, but we try to live
1039              * with it.
1040              *
1041              * In addition, in 4.2 (and...), a special protocol
1042              * is needed to pick up the TCP Urgent data in
1043              * the correct sequence.
1044              *
1045              * What we do is:  if we think we are in urgent
1046              * mode, we look to see if we are "at the mark".
1047              * If we are, we do an OOB receive.  If we run
1048              * this twice, we will do the OOB receive twice,
1049              * but the second will fail, since the second
1050              * time we were "at the mark", but there wasn't
1051              * any data there (the kernel doesn't reset
1052              * "at the mark" until we do a normal read).
1053              * Once we've read the OOB data, we go ahead
1054              * and do normal reads.
1055              *
1056              * There is also another problem, which is that
1057              * since the OOB byte we read doesn't put us
1058              * out of OOB state, and since that byte is most
1059              * likely the TELNET DM (data mark), we would
1060              * stay in the TELNET SYNCH (SYNCHing) state.
1061              * So, clocks to the rescue.  If we've "just"
1062              * received a DM, then we test for the
1063              * presence of OOB data when the receive OOB
1064              * fails (and AFTER we did the normal mode read
1065              * to clear "at the mark").
1066              */
1067             if (SYNCHing) {
1068                 int atmark;
1069
1070                 ioctl(net, SIOCATMARK, (char *)&atmark);
1071                 if (atmark) {
1072                     ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
1073                     if ((ncc == -1) && (errno == EINVAL)) {
1074                         ncc = read(net, netibuf, sizeof (netibuf));
1075                         if (sequenceIs(didnetreceive, gotDM)) {
1076                             SYNCHing = stilloob(net);
1077                         }
1078                     }
1079                 } else {
1080                     ncc = read(net, netibuf, sizeof (netibuf));
1081                 }
1082             } else {
1083                 ncc = read(net, netibuf, sizeof (netibuf));
1084             }
1085             settimer(didnetreceive);
1086 #else   /* !defined(SO_OOBINLINE)) */
1087             ncc = read(net, netibuf, sizeof (netibuf));
1088 #endif  /* !defined(SO_OOBINLINE)) */
1089             if (ncc < 0 && errno == EWOULDBLOCK)
1090                 ncc = 0;
1091             else {
1092                 if (ncc <= 0) {
1093                     break;
1094                 }
1095                 netip = netibuf;
1096             }
1097             DIAG((TD_REPORT | TD_NETDATA), {
1098                 output_data("td: netread %d chars\r\n", ncc);
1099                 });
1100             DIAG(TD_NETDATA, printdata("nd", netip, ncc));
1101         }
1102
1103         /*
1104          * Something to read from the pty...
1105          */
1106         if (FD_ISSET(p, &ibits)) {
1107 #ifdef STREAMSPTY
1108             if (really_stream)
1109                 pcc = readstream(p, ptyibuf, BUFSIZ);
1110             else
1111 #endif
1112                 pcc = read(p, ptyibuf, BUFSIZ);
1113
1114             /*
1115              * On some systems, if we try to read something
1116              * off the master side before the slave side is
1117              * opened, we get EIO.
1118              */
1119             if (pcc < 0 && (errno == EWOULDBLOCK ||
1120 #ifdef  EAGAIN
1121                             errno == EAGAIN ||
1122 #endif
1123                             errno == EIO)) {
1124                 pcc = 0;
1125             } else {
1126                 if (pcc <= 0)
1127                     break;
1128                 if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
1129                     netclear(); /* clear buffer back */
1130 #ifndef NO_URGENT
1131                     /*
1132                      * There are client telnets on some
1133                      * operating systems get screwed up
1134                      * royally if we send them urgent
1135                      * mode data.
1136                      */
1137                     output_data ("%c%c", IAC, DM);
1138
1139                     neturg = nfrontp-1; /* off by one XXX */
1140                     DIAG(TD_OPTIONS,
1141                          printoption("td: send IAC", DM));
1142
1143 #endif
1144                 }
1145                 if (his_state_is_will(TELOPT_LFLOW) &&
1146                     (ptyibuf[0] &
1147                      (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
1148                     int newflow =
1149                         ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
1150                     if (newflow != flowmode) {
1151                         flowmode = newflow;
1152                         output_data("%c%c%c%c%c%c",
1153                                     IAC, SB, TELOPT_LFLOW,
1154                                     flowmode ? LFLOW_ON
1155                                     : LFLOW_OFF,
1156                                     IAC, SE);
1157                         DIAG(TD_OPTIONS, printsub('>',
1158                                                   (unsigned char *)nfrontp-4,
1159                                                   4););
1160                     }
1161                 }
1162                 pcc--;
1163                 ptyip = ptyibuf+1;
1164             }
1165         }
1166
1167         while (pcc > 0) {
1168             if ((&netobuf[BUFSIZ] - nfrontp) < 3)
1169                 break;
1170             c = *ptyip++ & 0377, pcc--;
1171             if (c == IAC)
1172                 *nfrontp++ = c;
1173             *nfrontp++ = c;
1174             if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
1175                 if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
1176                     *nfrontp++ = *ptyip++ & 0377;
1177                     pcc--;
1178                 } else
1179                     *nfrontp++ = '\0';
1180             }
1181         }
1182
1183         if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
1184             netflush();
1185         if (ncc > 0)
1186             telrcv();
1187         if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
1188             ptyflush();
1189     }
1190     cleanup(0);
1191 }
1192
1193 #ifndef TCSIG
1194 # ifdef TIOCSIG
1195 #  define TCSIG TIOCSIG
1196 # endif
1197 #endif
1198
1199 #ifdef  STREAMSPTY
1200
1201     int flowison = -1;  /* current state of flow: -1 is unknown */
1202
1203 int
1204 readstream(int p, char *ibuf, int bufsize)
1205 {
1206     int flags = 0;
1207     int ret = 0;
1208     struct termios *tsp;
1209 #if 0
1210     struct termio *tp;
1211 #endif
1212     struct iocblk *ip;
1213     char vstop, vstart;
1214     int ixon;
1215     int newflow;
1216
1217     strbufc.maxlen = BUFSIZ;
1218     strbufc.buf = (char *)ctlbuf;
1219     strbufd.maxlen = bufsize-1;
1220     strbufd.len = 0;
1221     strbufd.buf = ibuf+1;
1222     ibuf[0] = 0;
1223
1224     ret = getmsg(p, &strbufc, &strbufd, &flags);
1225     if (ret < 0)  /* error of some sort -- probably EAGAIN */
1226         return(-1);
1227
1228     if (strbufc.len <= 0 || ctlbuf[0] == M_DATA) {
1229         /* data message */
1230         if (strbufd.len > 0) {                  /* real data */
1231             return(strbufd.len + 1);    /* count header char */
1232         } else {
1233             /* nothing there */
1234             errno = EAGAIN;
1235             return(-1);
1236         }
1237     }
1238
1239     /*
1240      * It's a control message.  Return 1, to look at the flag we set
1241      */
1242
1243     switch (ctlbuf[0]) {
1244     case M_FLUSH:
1245         if (ibuf[1] & FLUSHW)
1246             ibuf[0] = TIOCPKT_FLUSHWRITE;
1247         return(1);
1248
1249     case M_IOCTL:
1250         ip = (struct iocblk *) (ibuf+1);
1251
1252         switch (ip->ioc_cmd) {
1253 #ifdef TCSETS
1254         case TCSETS:
1255         case TCSETSW:
1256         case TCSETSF:
1257             tsp = (struct termios *)
1258                 (ibuf+1 + sizeof(struct iocblk));
1259             vstop = tsp->c_cc[VSTOP];
1260             vstart = tsp->c_cc[VSTART];
1261             ixon = tsp->c_iflag & IXON;
1262             break;
1263 #endif
1264 #if 0
1265         case TCSETA:
1266         case TCSETAW:
1267         case TCSETAF:
1268             tp = (struct termio *) (ibuf+1 + sizeof(struct iocblk));
1269             vstop = tp->c_cc[VSTOP];
1270             vstart = tp->c_cc[VSTART];
1271             ixon = tp->c_iflag & IXON;
1272             break;
1273 #endif
1274         default:
1275             errno = EAGAIN;
1276             return(-1);
1277         }
1278
1279         newflow =  (ixon && (vstart == 021) && (vstop == 023)) ? 1 : 0;
1280         if (newflow != flowison) {  /* it's a change */
1281             flowison = newflow;
1282             ibuf[0] = newflow ? TIOCPKT_DOSTOP : TIOCPKT_NOSTOP;
1283             return(1);
1284         }
1285     }
1286
1287     /* nothing worth doing anything about */
1288     errno = EAGAIN;
1289     return(-1);
1290 }
1291 #endif /* STREAMSPTY */
1292
1293 /*
1294  * Send interrupt to process on other side of pty.
1295  * If it is in raw mode, just write NULL;
1296  * otherwise, write intr char.
1297  */
1298 void
1299 interrupt()
1300 {
1301     ptyflush(); /* half-hearted */
1302
1303 #if defined(STREAMSPTY) && defined(TIOCSIGNAL)
1304     /* Streams PTY style ioctl to post a signal */
1305     if (really_stream)
1306         {
1307             int sig = SIGINT;
1308             ioctl(ourpty, TIOCSIGNAL, &sig);
1309             ioctl(ourpty, I_FLUSH, FLUSHR);
1310         }
1311 #else
1312 #ifdef  TCSIG
1313     ioctl(ourpty, TCSIG, (char *)SIGINT);
1314 #else   /* TCSIG */
1315     init_termbuf();
1316     *pfrontp++ = slctab[SLC_IP].sptr ?
1317         (unsigned char)*slctab[SLC_IP].sptr : '\177';
1318 #endif  /* TCSIG */
1319 #endif
1320 }
1321
1322 /*
1323  * Send quit to process on other side of pty.
1324  * If it is in raw mode, just write NULL;
1325  * otherwise, write quit char.
1326  */
1327 void
1328 sendbrk()
1329 {
1330     ptyflush(); /* half-hearted */
1331 #ifdef  TCSIG
1332     ioctl(ourpty, TCSIG, (char *)SIGQUIT);
1333 #else   /* TCSIG */
1334     init_termbuf();
1335     *pfrontp++ = slctab[SLC_ABORT].sptr ?
1336         (unsigned char)*slctab[SLC_ABORT].sptr : '\034';
1337 #endif  /* TCSIG */
1338 }
1339
1340 void
1341 sendsusp()
1342 {
1343 #ifdef  SIGTSTP
1344     ptyflush(); /* half-hearted */
1345 # ifdef TCSIG
1346     ioctl(ourpty, TCSIG, (char *)SIGTSTP);
1347 # else  /* TCSIG */
1348     *pfrontp++ = slctab[SLC_SUSP].sptr ?
1349         (unsigned char)*slctab[SLC_SUSP].sptr : '\032';
1350 # endif /* TCSIG */
1351 #endif  /* SIGTSTP */
1352 }
1353
1354 /*
1355  * When we get an AYT, if ^T is enabled, use that.  Otherwise,
1356  * just send back "[Yes]".
1357  */
1358 void
1359 recv_ayt()
1360 {
1361 #if     defined(SIGINFO) && defined(TCSIG)
1362     if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
1363         ioctl(ourpty, TCSIG, (char *)SIGINFO);
1364         return;
1365     }
1366 #endif
1367     output_data("\r\n[Yes]\r\n");
1368 }
1369
1370 void
1371 doeof()
1372 {
1373     init_termbuf();
1374
1375     *pfrontp++ = slctab[SLC_EOF].sptr ?
1376         (unsigned char)*slctab[SLC_EOF].sptr : '\004';
1377 }