telnetd.tproj/telnetd.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1989, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  */
  56
  57 #ifndef lint
  58 static char copyright[] =
  59 "@(#) Copyright (c) 1989, 1993\n\
  60         The Regents of the University of California.  All rights reserved.\n";
  61 #endif /* not lint */
  62
  63 #ifndef lint
  64 static char sccsid[] = "@(#)telnetd.c   8.4 (Berkeley) 5/30/95";
  65 #endif /* not lint */
  66
  67 #include "telnetd.h"
  68 #include "pathnames.h"
  69
  70 #if     defined(_SC_CRAY_SECURE_SYS) && !defined(SCM_SECURITY)
  71 /*
  72  * UNICOS 6.0/6.1 do not have SCM_SECURITY defined, so we can
  73  * use it to tell us to turn off all the socket security code,
  74  * since that is only used in UNICOS 7.0 and later.
  75  */
  76 # undef _SC_CRAY_SECURE_SYS
  77 #endif
  78
  79 #if     defined(_SC_CRAY_SECURE_SYS)
  80 #include <sys/sysv.h>
  81 #include <sys/secdev.h>
  82 # ifdef SO_SEC_MULTI            /* 8.0 code */
  83 #include <sys/secparm.h>
  84 #include <sys/usrv.h>
  85 # endif /* SO_SEC_MULTI */
  86 int     secflag;
  87 char    tty_dev[16];
  88 struct  secdev dv;
  89 struct  sysv sysv;
  90 # ifdef SO_SEC_MULTI            /* 8.0 code */
  91 struct  socksec ss;
  92 # else /* SO_SEC_MULTI */       /* 7.0 code */
  93 struct  socket_security ss;
  94 # endif /* SO_SEC_MULTI */
  95 #endif  /* _SC_CRAY_SECURE_SYS */
  96
  97 #if     defined(AUTHENTICATION)
  98 #include <libtelnet/auth.h>
  99 int     auth_level = 0;
 100 #endif
 101 #if     defined(SecurID)
 102 int     require_SecurID = 0;
 103 #endif
 104
 105 extern  int utmp_len;
 106 int     registerd_host_only = 0;
 107
 108 #ifdef  STREAMSPTY
 109 # include <stropts.h>
 110 # include <termio.h>
 111 /* make sure we don't get the bsd version */
 112 # include "/usr/include/sys/tty.h"
 113 # include <sys/ptyvar.h>
 114
 115 /*
 116  * Because of the way ptyibuf is used with streams messages, we need
 117  * ptyibuf+1 to be on a full-word boundary.  The following wierdness
 118  * is simply to make that happen.
 119  */
 120 long    ptyibufbuf[BUFSIZ/sizeof(long)+1];
 121 char    *ptyibuf = ((char *)&ptyibufbuf[1])-1;
 122 char    *ptyip = ((char *)&ptyibufbuf[1])-1;
 123 char    ptyibuf2[BUFSIZ];
 124 unsigned char ctlbuf[BUFSIZ];
 125 struct  strbuf strbufc, strbufd;
 126
 127 int readstream();
 128
 129 #else   /* ! STREAMPTY */
 130
 131 /*
 132  * I/O data buffers,
 133  * pointers, and counters.
 134  */
 135 char    ptyibuf[BUFSIZ], *ptyip = ptyibuf;
 136 char    ptyibuf2[BUFSIZ];
 137
 138 #endif /* ! STREAMPTY */
 139
 140 int     hostinfo = 1;                   /* do we print login banner? */
 141
 142 #ifdef  CRAY
 143 extern int      newmap; /* nonzero if \n maps to ^M^J */
 144 int     lowpty = 0, highpty;    /* low, high pty numbers */
 145 #endif /* CRAY */
 146
 147 int debug = 0;
 148 int keepalive = 1;
 149 char *progname;
 150
 151 extern void usage P((void));
 152 void doit(struct sockaddr_in *);
 153 int terminaltypeok(char *);
 154 void startslave(char *, int, char *);
 155
 156
 157 /*
 158  * The string to pass to getopt().  We do it this way so
 159  * that only the actual options that we support will be
 160  * passed off to getopt().
 161  */
 162 char valid_opts[] = {
 163         'd', ':', 'h', 'k', 'n', 'S', ':', 'u', ':', 'U',
 164 #ifdef  AUTHENTICATION
 165         'a', ':', 'X', ':',
 166 #endif
 167 #ifdef BFTPDAEMON
 168         'B',
 169 #endif
 170 #ifdef DIAGNOSTICS
 171         'D', ':',
 172 #endif
 173 #ifdef  ENCRYPTION
 174         'e', ':',
 175 #endif
 176 #if     defined(CRAY) && defined(NEWINIT)
 177         'I', ':',
 178 #endif
 179 #ifdef  LINEMODE
 180         'l',
 181 #endif
 182 #ifdef CRAY
 183         'r', ':',
 184 #endif
 185 #ifdef  SecurID
 186         's',
 187 #endif
 188         '\0'
 189 };
 190
 191 int
 192 main(argc, argv)
 193         char *argv[];
 194 {
 195         struct sockaddr_in from;
 196         int on = 1, fromlen;
 197         register int ch;
 198         extern char *optarg;
 199         extern int optind;
 200 #if     defined(IPPROTO_IP) && defined(IP_TOS)
 201         int tos = -1;
 202 #endif
 203
 204         pfrontp = pbackp = ptyobuf;
 205         netip = netibuf;
 206         nfrontp = nbackp = netobuf;
 207 #ifdef  ENCRYPTION
 208         nclearto = 0;
 209 #endif  /* ENCRYPTION */
 210
 211         progname = *argv;
 212
 213 #ifdef CRAY
 214         /*
 215          * Get number of pty's before trying to process options,
 216          * which may include changing pty range.
 217          */
 218         highpty = getnpty();
 219 #endif /* CRAY */
 220
 221         while ((ch = getopt(argc, argv, valid_opts)) != EOF) {
 222                 switch(ch) {
 223
 224 #ifdef  AUTHENTICATION
 225                 case 'a':
 226                         /*
 227                          * Check for required authentication level
 228                          */
 229                         if (strcmp(optarg, "debug") == 0) {
 230                                 extern int auth_debug_mode;
 231                                 auth_debug_mode = 1;
 232                         } else if (strcasecmp(optarg, "none") == 0) {
 233                                 auth_level = 0;
 234                         } else if (strcasecmp(optarg, "other") == 0) {
 235                                 auth_level = AUTH_OTHER;
 236                         } else if (strcasecmp(optarg, "user") == 0) {
 237                                 auth_level = AUTH_USER;
 238                         } else if (strcasecmp(optarg, "valid") == 0) {
 239                                 auth_level = AUTH_VALID;
 240                         } else if (strcasecmp(optarg, "off") == 0) {
 241                                 /*
 242                                  * This hack turns off authentication
 243                                  */
 244                                 auth_level = -1;
 245                         } else {
 246                                 fprintf(stderr,
 247                             "telnetd: unknown authorization level for -a\n");
 248                         }
 249                         break;
 250 #endif  /* AUTHENTICATION */
 251
 252 #ifdef BFTPDAEMON
 253                 case 'B':
 254                         bftpd++;
 255                         break;
 256 #endif /* BFTPDAEMON */
 257
 258                 case 'd':
 259                         if (strcmp(optarg, "ebug") == 0) {
 260                                 debug++;
 261                                 break;
 262                         }
 263                         usage();
 264                         /* NOTREACHED */
 265                         break;
 266
 267 #ifdef DIAGNOSTICS
 268                 case 'D':
 269                         /*
 270                          * Check for desired diagnostics capabilities.
 271                          */
 272                         if (!strcmp(optarg, "report")) {
 273                                 diagnostic |= TD_REPORT|TD_OPTIONS;
 274                         } else if (!strcmp(optarg, "exercise")) {
 275                                 diagnostic |= TD_EXERCISE;
 276                         } else if (!strcmp(optarg, "netdata")) {
 277                                 diagnostic |= TD_NETDATA;
 278                         } else if (!strcmp(optarg, "ptydata")) {
 279                                 diagnostic |= TD_PTYDATA;
 280                         } else if (!strcmp(optarg, "options")) {
 281                                 diagnostic |= TD_OPTIONS;
 282                         } else {
 283                                 usage();
 284                                 /* NOT REACHED */
 285                         }
 286                         break;
 287 #endif /* DIAGNOSTICS */
 288
 289 #ifdef  ENCRYPTION
 290                 case 'e':
 291                         if (strcmp(optarg, "debug") == 0) {
 292                                 extern int encrypt_debug_mode;
 293                                 encrypt_debug_mode = 1;
 294                                 break;
 295                         }
 296                         usage();
 297                         /* NOTREACHED */
 298                         break;
 299 #endif  /* ENCRYPTION */
 300
 301                 case 'h':
 302                         hostinfo = 0;
 303                         break;
 304
 305 #if     defined(CRAY) && defined(NEWINIT)
 306                 case 'I':
 307                     {
 308                         extern char *gen_id;
 309                         gen_id = optarg;
 310                         break;
 311                     }
 312 #endif  /* defined(CRAY) && defined(NEWINIT) */
 313
 314 #ifdef  LINEMODE
 315                 case 'l':
 316                         alwayslinemode = 1;
 317                         break;
 318 #endif  /* LINEMODE */
 319
 320                 case 'k':
 321 #if     defined(LINEMODE) && defined(KLUDGELINEMODE)
 322                         lmodetype = NO_AUTOKLUDGE;
 323 #else
 324                         /* ignore -k option if built without kludge linemode */
 325 #endif  /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
 326                         break;
 327
 328                 case 'n':
 329                         keepalive = 0;
 330                         break;
 331
 332 #ifdef CRAY
 333                 case 'r':
 334                     {
 335                         char *strchr();
 336                         char *c;
 337
 338                         /*
 339                          * Allow the specification of alterations
 340                          * to the pty search range.  It is legal to
 341                          * specify only one, and not change the
 342                          * other from its default.
 343                          */
 344                         c = strchr(optarg, '-');
 345                         if (c) {
 346                                 *c++ = '\0';
 347                                 highpty = atoi(c);
 348                         }
 349                         if (*optarg != '\0')
 350                                 lowpty = atoi(optarg);
 351                         if ((lowpty > highpty) || (lowpty < 0) ||
 352                                                         (highpty > 32767)) {
 353                                 usage();
 354                                 /* NOT REACHED */
 355                         }
 356                         break;
 357                     }
 358 #endif  /* CRAY */
 359
 360 #ifdef  SecurID
 361                 case 's':
 362                         /* SecurID required */
 363                         require_SecurID = 1;
 364                         break;
 365 #endif  /* SecurID */
 366                 case 'S':
 367 #ifdef  HAS_GETTOS
 368                         if ((tos = parsetos(optarg, "tcp")) < 0)
 369                                 fprintf(stderr, "%s%s%s\n",
 370                                         "telnetd: Bad TOS argument '", optarg,
 371                                         "'; will try to use default TOS");
 372 #else
 373                         fprintf(stderr, "%s%s\n", "TOS option unavailable; ",
 374                                                 "-S flag not supported\n");
 375 #endif
 376                         break;
 377
 378                 case 'u':
 379                         utmp_len = atoi(optarg);
 380                         break;
 381
 382                 case 'U':
 383                         registerd_host_only = 1;
 384                         break;
 385
 386 #ifdef  AUTHENTICATION
 387                 case 'X':
 388                         /*
 389                          * Check for invalid authentication types
 390                          */
 391                         auth_disable_name(optarg);
 392                         break;
 393 #endif  /* AUTHENTICATION */
 394
 395                 default:
 396                         fprintf(stderr, "telnetd: %c: unknown option\n", ch);
 397                         /* FALLTHROUGH */
 398                 case '?':
 399                         usage();
 400                         /* NOTREACHED */
 401                 }
 402         }
 403
 404         argc -= optind;
 405         argv += optind;
 406
 407         if (debug) {
 408             int s, ns, foo;
 409             struct servent *sp;
 410             static struct sockaddr_in sin = { AF_INET };
 411
 412             if (argc > 1) {
 413                 usage();
 414                 /* NOT REACHED */
 415             } else if (argc == 1) {
 416                     if (sp = getservbyname(*argv, "tcp")) {
 417                         sin.sin_port = sp->s_port;
 418                     } else {
 419                         sin.sin_port = atoi(*argv);
 420                         if ((int)sin.sin_port <= 0) {
 421                             fprintf(stderr, "telnetd: %s: bad port #\n", *argv);
 422                             usage();
 423                             /* NOT REACHED */
 424                         }
 425                         sin.sin_port = htons((u_short)sin.sin_port);
 426                    }
 427             } else {
 428                 sp = getservbyname("telnet", "tcp");
 429                 if (sp == 0) {
 430                     fprintf(stderr, "telnetd: tcp/telnet: unknown service\n");
 431                     exit(1);
 432                 }
 433                 sin.sin_port = sp->s_port;
 434             }
 435
 436             s = socket(AF_INET, SOCK_STREAM, 0);
 437             if (s < 0) {
 438                     perror("telnetd: socket");;
 439                     exit(1);
 440             }
 441             (void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
 442                                 (char *)&on, sizeof(on));
 443             if (bind(s, (struct sockaddr *)&sin, sizeof sin) < 0) {
 444                 perror("bind");
 445                 exit(1);
 446             }
 447             if (listen(s, 1) < 0) {
 448                 perror("listen");
 449                 exit(1);
 450             }
 451             foo = sizeof sin;
 452             ns = accept(s, (struct sockaddr *)&sin, &foo);
 453             if (ns < 0) {
 454                 perror("accept");
 455                 exit(1);
 456             }
 457             (void) dup2(ns, 0);
 458             (void) close(ns);
 459             (void) close(s);
 460 #ifdef convex
 461         } else if (argc == 1) {
 462                 ; /* VOID*/             /* Just ignore the host/port name */
 463 #endif
 464         } else if (argc > 0) {
 465                 usage();
 466                 /* NOT REACHED */
 467         }
 468
 469 #if     defined(_SC_CRAY_SECURE_SYS)
 470         secflag = sysconf(_SC_CRAY_SECURE_SYS);
 471
 472         /*
 473          *      Get socket's security label
 474          */
 475         if (secflag)  {
 476                 int szss = sizeof(ss);
 477 #ifdef SO_SEC_MULTI                     /* 8.0 code */
 478                 int sock_multi;
 479                 int szi = sizeof(int);
 480 #endif /* SO_SEC_MULTI */
 481
 482                 memset((char *)&dv, 0, sizeof(dv));
 483
 484                 if (getsysv(&sysv, sizeof(struct sysv)) != 0) {
 485                         perror("getsysv");
 486                         exit(1);
 487                 }
 488
 489                 /*
 490                  *      Get socket security label and set device values
 491                  *         {security label to be set on ttyp device}
 492                  */
 493 #ifdef SO_SEC_MULTI                     /* 8.0 code */
 494                 if ((getsockopt(0, SOL_SOCKET, SO_SECURITY,
 495                                (char *)&ss, &szss) < 0) ||
 496                     (getsockopt(0, SOL_SOCKET, SO_SEC_MULTI,
 497                                 (char *)&sock_multi, &szi) < 0)) {
 498                         perror("getsockopt");
 499                         exit(1);
 500                 } else {
 501                         dv.dv_actlvl = ss.ss_actlabel.lt_level;
 502                         dv.dv_actcmp = ss.ss_actlabel.lt_compart;
 503                         if (!sock_multi) {
 504                                 dv.dv_minlvl = dv.dv_maxlvl = dv.dv_actlvl;
 505                                 dv.dv_valcmp = dv.dv_actcmp;
 506                         } else {
 507                                 dv.dv_minlvl = ss.ss_minlabel.lt_level;
 508                                 dv.dv_maxlvl = ss.ss_maxlabel.lt_level;
 509                                 dv.dv_valcmp = ss.ss_maxlabel.lt_compart;
 510                         }
 511                         dv.dv_devflg = 0;
 512                 }
 513 #else /* SO_SEC_MULTI */                /* 7.0 code */
 514                 if (getsockopt(0, SOL_SOCKET, SO_SECURITY,
 515                                 (char *)&ss, &szss) >= 0) {
 516                         dv.dv_actlvl = ss.ss_slevel;
 517                         dv.dv_actcmp = ss.ss_compart;
 518                         dv.dv_minlvl = ss.ss_minlvl;
 519                         dv.dv_maxlvl = ss.ss_maxlvl;
 520                         dv.dv_valcmp = ss.ss_maxcmp;
 521                 }
 522 #endif /* SO_SEC_MULTI */
 523         }
 524 #endif  /* _SC_CRAY_SECURE_SYS */
 525
 526         openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
 527         fromlen = sizeof (from);
 528         if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
 529                 fprintf(stderr, "%s: ", progname);
 530                 perror("getpeername");
 531                 _exit(1);
 532         }
 533         if (keepalive &&
 534             setsockopt(0, SOL_SOCKET, SO_KEEPALIVE,
 535                         (char *)&on, sizeof (on)) < 0) {
 536                 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
 537         }
 538
 539 #if     defined(IPPROTO_IP) && defined(IP_TOS)
 540         {
 541 # if    defined(HAS_GETTOS)
 542                 struct tosent *tp;
 543                 if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
 544                         tos = tp->t_tos;
 545 # endif
 546                 if (tos < 0)
 547                         tos = 020;      /* Low Delay bit */
 548                 if (tos
 549                    && (setsockopt(0, IPPROTO_IP, IP_TOS,
 550                                   (char *)&tos, sizeof(tos)) < 0)
 551                    && (errno != ENOPROTOOPT) )
 552                         syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
 553         }
 554 #endif  /* defined(IPPROTO_IP) && defined(IP_TOS) */
 555         net = 0;
 556         doit(&from);
 557         /* NOTREACHED */
 558         exit(0);
 559 }  /* end of main */
 560
 561         void
 562 usage()
 563 {
 564         fprintf(stderr, "Usage: telnetd");
 565 #ifdef  AUTHENTICATION
 566         fprintf(stderr, " [-a (debug|other|user|valid|off|none)]\n\t");
 567 #endif
 568 #ifdef BFTPDAEMON
 569         fprintf(stderr, " [-B]");
 570 #endif
 571         fprintf(stderr, " [-debug]");
 572 #ifdef DIAGNOSTICS
 573         fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
 574 #endif
 575 #ifdef  AUTHENTICATION
 576         fprintf(stderr, " [-edebug]");
 577 #endif
 578         fprintf(stderr, " [-h]");
 579 #if     defined(CRAY) && defined(NEWINIT)
 580         fprintf(stderr, " [-Iinitid]");
 581 #endif
 582 #if     defined(LINEMODE) && defined(KLUDGELINEMODE)
 583         fprintf(stderr, " [-k]");
 584 #endif
 585 #ifdef LINEMODE
 586         fprintf(stderr, " [-l]");
 587 #endif
 588         fprintf(stderr, " [-n]");
 589 #ifdef  CRAY
 590         fprintf(stderr, " [-r[lowpty]-[highpty]]");
 591 #endif
 592         fprintf(stderr, "\n\t");
 593 #ifdef  SecurID
 594         fprintf(stderr, " [-s]");
 595 #endif
 596 #ifdef  HAS_GETTOS
 597         fprintf(stderr, " [-S tos]");
 598 #endif
 599 #ifdef  AUTHENTICATION
 600         fprintf(stderr, " [-X auth-type]");
 601 #endif
 602         fprintf(stderr, " [-u utmp_hostname_length] [-U]");
 603         fprintf(stderr, " [port]\n");
 604         exit(1);
 605 }
 606
 607 /*
 608  * getterminaltype
 609  *
 610  *      Ask the other end to send along its terminal type and speed.
 611  * Output is the variable terminaltype filled in.
 612  */
 613 static unsigned char ttytype_sbbuf[] = {
 614         IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
 615 };
 616
 617     int
 618 getterminaltype(name)
 619     char *name;
 620 {
 621     int retval = -1;
 622     void _gettermname();
 623
 624     settimer(baseline);
 625 #if     defined(AUTHENTICATION)
 626     /*
 627      * Handle the Authentication option before we do anything else.
 628      */
 629     send_do(TELOPT_AUTHENTICATION, 1);
 630     while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
 631         ttloop();
 632     if (his_state_is_will(TELOPT_AUTHENTICATION)) {
 633         retval = auth_wait(name);
 634     }
 635 #endif
 636
 637 #ifdef  ENCRYPTION
 638     send_will(TELOPT_ENCRYPT, 1);
 639 #endif  /* ENCRYPTION */
 640     send_do(TELOPT_TTYPE, 1);
 641     send_do(TELOPT_TSPEED, 1);
 642     send_do(TELOPT_XDISPLOC, 1);
 643     send_do(TELOPT_NEW_ENVIRON, 1);
 644     send_do(TELOPT_OLD_ENVIRON, 1);
 645     while (
 646 #ifdef  ENCRYPTION
 647            his_do_dont_is_changing(TELOPT_ENCRYPT) ||
 648 #endif  /* ENCRYPTION */
 649            his_will_wont_is_changing(TELOPT_TTYPE) ||
 650            his_will_wont_is_changing(TELOPT_TSPEED) ||
 651            his_will_wont_is_changing(TELOPT_XDISPLOC) ||
 652            his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
 653            his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
 654         ttloop();
 655     }
 656 #ifdef  ENCRYPTION
 657     /*
 658      * Wait for the negotiation of what type of encryption we can
 659      * send with.  If autoencrypt is not set, this will just return.
 660      */
 661     if (his_state_is_will(TELOPT_ENCRYPT)) {
 662         encrypt_wait();
 663     }
 664 #endif  /* ENCRYPTION */
 665     if (his_state_is_will(TELOPT_TSPEED)) {
 666         static unsigned char sb[] =
 667                         { IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
 668
 669         memmove(nfrontp, sb, sizeof sb);
 670         nfrontp += sizeof sb;
 671         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 672     }
 673     if (his_state_is_will(TELOPT_XDISPLOC)) {
 674         static unsigned char sb[] =
 675                         { IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
 676
 677         memmove(nfrontp, sb, sizeof sb);
 678         nfrontp += sizeof sb;
 679         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 680     }
 681     if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
 682         static unsigned char sb[] =
 683                         { IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
 684
 685         memmove(nfrontp, sb, sizeof sb);
 686         nfrontp += sizeof sb;
 687         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 688     }
 689     else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
 690         static unsigned char sb[] =
 691                         { IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
 692
 693         memmove(nfrontp, sb, sizeof sb);
 694         nfrontp += sizeof sb;
 695         DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
 696     }
 697     if (his_state_is_will(TELOPT_TTYPE)) {
 698
 699         memmove(nfrontp, ttytype_sbbuf, sizeof ttytype_sbbuf);
 700         nfrontp += sizeof ttytype_sbbuf;
 701         DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
 702                                         sizeof ttytype_sbbuf - 2););
 703     }
 704     if (his_state_is_will(TELOPT_TSPEED)) {
 705         while (sequenceIs(tspeedsubopt, baseline))
 706             ttloop();
 707     }
 708     if (his_state_is_will(TELOPT_XDISPLOC)) {
 709         while (sequenceIs(xdisplocsubopt, baseline))
 710             ttloop();
 711     }
 712     if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
 713         while (sequenceIs(environsubopt, baseline))
 714             ttloop();
 715     }
 716     if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
 717         while (sequenceIs(oenvironsubopt, baseline))
 718             ttloop();
 719     }
 720     if (his_state_is_will(TELOPT_TTYPE)) {
 721         char first[256], last[256];
 722
 723         while (sequenceIs(ttypesubopt, baseline))
 724             ttloop();
 725
 726         /*
 727          * If the other side has already disabled the option, then
 728          * we have to just go with what we (might) have already gotten.
 729          */
 730         if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
 731             (void) strncpy(first, terminaltype, sizeof(first));
 732             for(;;) {
 733                 /*
 734                  * Save the unknown name, and request the next name.
 735                  */
 736                 (void) strncpy(last, terminaltype, sizeof(last));
 737                 _gettermname();
 738                 if (terminaltypeok(terminaltype))
 739                     break;
 740                 if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
 741                     his_state_is_wont(TELOPT_TTYPE)) {
 742                     /*
 743                      * We've hit the end.  If this is the same as
 744                      * the first name, just go with it.
 745                      */
 746                     if (strncmp(first, terminaltype, sizeof(first)) == 0)
 747                         break;
 748                     /*
 749                      * Get the terminal name one more time, so that
 750                      * RFC1091 compliant telnets will cycle back to
 751                      * the start of the list.
 752                      */
 753                      _gettermname();
 754                     if (strncmp(first, terminaltype, sizeof(first)) != 0)
 755                         (void) strncpy(terminaltype, first, sizeof(first));
 756                     break;
 757                 }
 758             }
 759         }
 760     }
 761     return(retval);
 762 }  /* end of getterminaltype */
 763
 764     void
 765 _gettermname()
 766 {
 767     /*
 768      * If the client turned off the option,
 769      * we can't send another request, so we
 770      * just return.
 771      */
 772     if (his_state_is_wont(TELOPT_TTYPE))
 773         return;
 774     settimer(baseline);
 775     memmove(nfrontp, ttytype_sbbuf, sizeof ttytype_sbbuf);
 776     nfrontp += sizeof ttytype_sbbuf;
 777     DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
 778                                         sizeof ttytype_sbbuf - 2););
 779     while (sequenceIs(ttypesubopt, baseline))
 780         ttloop();
 781 }
 782
 783     int
 784 terminaltypeok(s)
 785     char *s;
 786 {
 787     char buf[1024];
 788
 789     if (terminaltype == NULL)
 790         return(1);
 791
 792     /*
 793      * tgetent() will return 1 if the type is known, and
 794      * 0 if it is not known.  If it returns -1, it couldn't
 795      * open the database.  But if we can't open the database,
 796      * it won't help to say we failed, because we won't be
 797      * able to verify anything else.  So, we treat -1 like 1.
 798      */
 799     if (tgetent(buf, s) == 0)
 800         return(0);
 801     return(1);
 802 }
 803
 804 #ifndef MAXHOSTNAMELEN
 805 #define MAXHOSTNAMELEN 64
 806 #endif  /* MAXHOSTNAMELEN */
 807
 808 char *hostname;
 809 char host_name[MAXHOSTNAMELEN];
 810 char remote_host_name[MAXHOSTNAMELEN];
 811
 812 #ifndef convex
 813 extern void telnet P((int, int));
 814 #else
 815 extern void telnet P((int, int, char *));
 816 #endif
 817
 818 /*
 819  * Get a pty, scan input lines.
 820  */
 821 void
 822 doit(who)
 823         struct sockaddr_in *who;
 824 {
 825         char *host = NULL, *inet_ntoa();
 826         struct hostent *hp;
 827         int level;
 828         int ptynum;
 829         char user_name[256];
 830
 831         /*
 832          * Find an available pty to use.
 833          */
 834 #ifndef convex
 835         pty = getpty(&ptynum);
 836         if (pty < 0)
 837                 fatal(net, "All network ports in use");
 838 #else
 839         for (;;) {
 840                 char *lp;
 841                 extern char *line, *getpty();
 842
 843                 if ((lp = getpty()) == NULL)
 844                         fatal(net, "Out of ptys");
 845
 846                 if ((pty = open(lp, O_RDWR)) >= 0) {
 847                         strncpy(line,lp, sizeof(line)-1);
 848                         line[sizeof(line)-1] = '\0';
 849                         line[5] = 't';
 850                         break;
 851                 }
 852         }
 853 #endif
 854
 855 #if     defined(_SC_CRAY_SECURE_SYS)
 856         /*
 857          *      set ttyp line security label
 858          */
 859         if (secflag) {
 860                 char slave_dev[16];
 861
 862                 sprintf(tty_dev, "/dev/pty/%03d", ptynum);
 863                 if (setdevs(tty_dev, &dv) < 0)
 864                         fatal(net, "cannot set pty security");
 865                 sprintf(slave_dev, "/dev/ttyp%03d", ptynum);
 866                 if (setdevs(slave_dev, &dv) < 0)
 867                         fatal(net, "cannot set tty security");
 868         }
 869 #endif  /* _SC_CRAY_SECURE_SYS */
 870
 871         /* get name of connected client */
 872         hp = gethostbyaddr((char *)&who->sin_addr, sizeof (struct in_addr),
 873                 who->sin_family);
 874
 875         if (hp == NULL && registerd_host_only) {
 876                 fatal(net, "Couldn't resolve your address into a host name.\r\n\
 877          Please contact your net administrator");
 878         } else if (hp &&
 879             (strlen(hp->h_name) <= (unsigned int)((utmp_len < 0) ? -utmp_len
 880                                                                  : utmp_len))) {
 881                 host = hp->h_name;
 882         } else {
 883                 host = inet_ntoa(who->sin_addr);
 884         }
 885         /*
 886          * We must make a copy because Kerberos is probably going
 887          * to also do a gethost* and overwrite the static data...
 888          */
 889         strncpy(remote_host_name, host, sizeof(remote_host_name)-1);
 890         remote_host_name[sizeof(remote_host_name)-1] = 0;
 891         host = remote_host_name;
 892
 893         (void) gethostname(host_name, sizeof (host_name));
 894         hostname = host_name;
 895
 896 #if     defined(AUTHENTICATION) || defined(ENCRYPTION)
 897         auth_encrypt_init(hostname, host, "TELNETD", 1);
 898 #endif
 899
 900         init_env();
 901         /*
 902          * get terminal type.
 903          */
 904         *user_name = 0;
 905         level = getterminaltype(user_name);
 906         setenv("TERM", terminaltype ? terminaltype : "network", 1);
 907
 908         /*
 909          * Start up the login process on the slave side of the terminal
 910          */
 911 #ifndef convex
 912         startslave(host, level, user_name);
 913
 914 #if     defined(_SC_CRAY_SECURE_SYS)
 915         if (secflag) {
 916                 if (setulvl(dv.dv_actlvl) < 0)
 917                         fatal(net,"cannot setulvl()");
 918                 if (setucmp(dv.dv_actcmp) < 0)
 919                         fatal(net, "cannot setucmp()");
 920         }
 921 #endif  /* _SC_CRAY_SECURE_SYS */
 922
 923         telnet(net, pty);  /* begin server processing */
 924 #else
 925         telnet(net, pty, host);
 926 #endif
 927         /*NOTREACHED*/
 928 }  /* end of doit */
 929
 930 #if     defined(CRAY2) && defined(UNICOS5) && defined(UNICOS50)
 931         int
 932 Xterm_output(ibufp, obuf, icountp, ocount)
 933         char **ibufp, *obuf;
 934         int *icountp, ocount;
 935 {
 936         int ret;
 937         ret = term_output(*ibufp, obuf, *icountp, ocount);
 938         *ibufp += *icountp;
 939         *icountp = 0;
 940         return(ret);
 941 }
 942 #define term_output     Xterm_output
 943 #endif  /* defined(CRAY2) && defined(UNICOS5) && defined(UNICOS50) */
 944
 945 /*
 946  * Main loop.  Select from pty and network, and
 947  * hand data to telnet receiver finite state machine.
 948  */
 949         void
 950 #ifndef convex
 951 telnet(f, p)
 952 #else
 953 telnet(f, p, host)
 954 #endif
 955         int f, p;
 956 #ifdef convex
 957         char *host;
 958 #endif
 959 {
 960         int on = 1;
 961 #define TABBUFSIZ       512
 962         char    defent[TABBUFSIZ];
 963         char    defstrs[TABBUFSIZ];
 964 #undef  TABBUFSIZ
 965         char *HE;
 966         char *HN;
 967         char *IM;
 968         void netflush();
 969         int nfd;
 970
 971         /*
 972          * Initialize the slc mapping table.
 973          */
 974         get_slc_defaults();
 975
 976         /*
 977          * Do some tests where it is desireable to wait for a response.
 978          * Rather than doing them slowly, one at a time, do them all
 979          * at once.
 980          */
 981         if (my_state_is_wont(TELOPT_SGA))
 982                 send_will(TELOPT_SGA, 1);
 983         /*
 984          * Is the client side a 4.2 (NOT 4.3) system?  We need to know this
 985          * because 4.2 clients are unable to deal with TCP urgent data.
 986          *
 987          * To find out, we send out a "DO ECHO".  If the remote system
 988          * answers "WILL ECHO" it is probably a 4.2 client, and we note
 989          * that fact ("WILL ECHO" ==> that the client will echo what
 990          * WE, the server, sends it; it does NOT mean that the client will
 991          * echo the terminal input).
 992          */
 993         send_do(TELOPT_ECHO, 1);
 994
 995 #ifdef  LINEMODE
 996         if (his_state_is_wont(TELOPT_LINEMODE)) {
 997                 /* Query the peer for linemode support by trying to negotiate
 998                  * the linemode option.
 999                  */
1000                 linemode = 0;
1001                 editmode = 0;
1002                 send_do(TELOPT_LINEMODE, 1);  /* send do linemode */
1003         }
1004 #endif  /* LINEMODE */
1005
1006         /*
1007          * Send along a couple of other options that we wish to negotiate.
1008          */
1009         send_do(TELOPT_NAWS, 1);
1010         send_will(TELOPT_STATUS, 1);
1011         flowmode = 1;           /* default flow control state */
1012         restartany = -1;        /* uninitialized... */
1013         send_do(TELOPT_LFLOW, 1);
1014
1015         /*
1016          * Spin, waiting for a response from the DO ECHO.  However,
1017          * some REALLY DUMB telnets out there might not respond
1018          * to the DO ECHO.  So, we spin looking for NAWS, (most dumb
1019          * telnets so far seem to respond with WONT for a DO that
1020          * they don't understand...) because by the time we get the
1021          * response, it will already have processed the DO ECHO.
1022          * Kludge upon kludge.
1023          */
1024         while (his_will_wont_is_changing(TELOPT_NAWS))
1025                 ttloop();
1026
1027         /*
1028          * But...
1029          * The client might have sent a WILL NAWS as part of its
1030          * startup code; if so, we'll be here before we get the
1031          * response to the DO ECHO.  We'll make the assumption
1032          * that any implementation that understands about NAWS
1033          * is a modern enough implementation that it will respond
1034          * to our DO ECHO request; hence we'll do another spin
1035          * waiting for the ECHO option to settle down, which is
1036          * what we wanted to do in the first place...
1037          */
1038         if (his_want_state_is_will(TELOPT_ECHO) &&
1039             his_state_is_will(TELOPT_NAWS)) {
1040                 while (his_will_wont_is_changing(TELOPT_ECHO))
1041                         ttloop();
1042         }
1043         /*
1044          * On the off chance that the telnet client is broken and does not
1045          * respond to the DO ECHO we sent, (after all, we did send the
1046          * DO NAWS negotiation after the DO ECHO, and we won't get here
1047          * until a response to the DO NAWS comes back) simulate the
1048          * receipt of a will echo.  This will also send a WONT ECHO
1049          * to the client, since we assume that the client failed to
1050          * respond because it believes that it is already in DO ECHO
1051          * mode, which we do not want.
1052          */
1053         if (his_want_state_is_will(TELOPT_ECHO)) {
1054                 DIAG(TD_OPTIONS,
1055                         {sprintf(nfrontp, "td: simulating recv\r\n");
1056                          nfrontp += strlen(nfrontp);});
1057                 willoption(TELOPT_ECHO);
1058         }
1059
1060         /*
1061          * Finally, to clean things up, we turn on our echo.  This
1062          * will break stupid 4.2 telnets out of local terminal echo.
1063          */
1064
1065         if (my_state_is_wont(TELOPT_ECHO))
1066                 send_will(TELOPT_ECHO, 1);
1067
1068 #ifndef STREAMSPTY
1069         /*
1070          * Turn on packet mode
1071          */
1072         (void) ioctl(p, TIOCPKT, (char *)&on);
1073 #endif
1074
1075 #if     defined(LINEMODE) && defined(KLUDGELINEMODE)
1076         /*
1077          * Continuing line mode support.  If client does not support
1078          * real linemode, attempt to negotiate kludge linemode by sending
1079          * the do timing mark sequence.
1080          */
1081         if (lmodetype < REAL_LINEMODE)
1082                 send_do(TELOPT_TM, 1);
1083 #endif  /* defined(LINEMODE) && defined(KLUDGELINEMODE) */
1084
1085         /*
1086          * Call telrcv() once to pick up anything received during
1087          * terminal type negotiation, 4.2/4.3 determination, and
1088          * linemode negotiation.
1089          */
1090         telrcv();
1091
1092         (void) ioctl(f, FIONBIO, (char *)&on);
1093         (void) ioctl(p, FIONBIO, (char *)&on);
1094 #if     defined(CRAY2) && defined(UNICOS5)
1095         init_termdriver(f, p, interrupt, sendbrk);
1096 #endif
1097
1098 #if     defined(SO_OOBINLINE)
1099         (void) setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
1100                                 (char *)&on, sizeof on);
1101 #endif  /* defined(SO_OOBINLINE) */
1102
1103 #ifdef  SIGTSTP
1104         (void) signal(SIGTSTP, SIG_IGN);
1105 #endif
1106 #ifdef  SIGTTOU
1107         /*
1108          * Ignoring SIGTTOU keeps the kernel from blocking us
1109          * in ttioct() in /sys/tty.c.
1110          */
1111         (void) signal(SIGTTOU, SIG_IGN);
1112 #endif
1113
1114         (void) signal(SIGCHLD, cleanup);
1115
1116 #if     defined(CRAY2) && defined(UNICOS5)
1117         /*
1118          * Cray-2 will send a signal when pty modes are changed by slave
1119          * side.  Set up signal handler now.
1120          */
1121         if ((int)signal(SIGUSR1, termstat) < 0)
1122                 perror("signal");
1123         else if (ioctl(p, TCSIGME, (char *)SIGUSR1) < 0)
1124                 perror("ioctl:TCSIGME");
1125         /*
1126          * Make processing loop check terminal characteristics early on.
1127          */
1128         termstat();
1129 #endif
1130
1131 #ifdef  TIOCNOTTY
1132         {
1133                 register int t;
1134                 t = open(_PATH_TTY, O_RDWR);
1135                 if (t >= 0) {
1136                         (void) ioctl(t, TIOCNOTTY, (char *)0);
1137                         (void) close(t);
1138                 }
1139         }
1140 #endif
1141
1142 #if     defined(CRAY) && defined(NEWINIT) && defined(TIOCSCTTY)
1143         (void) setsid();
1144         ioctl(p, TIOCSCTTY, 0);
1145 #endif
1146
1147         /*
1148          * Show banner that getty never gave.
1149          *
1150          * We put the banner in the pty input buffer.  This way, it
1151          * gets carriage return null processing, etc., just like all
1152          * other pty --> client data.
1153          */
1154
1155 #if     !defined(CRAY) || !defined(NEWINIT)
1156         if (getenv("USER"))
1157                 hostinfo = 0;
1158 #endif
1159
1160         if (getent(defent, "default") == 1) {
1161                 char *Getstr();
1162                 char *cp=defstrs;
1163
1164                 HE = Getstr("he", &cp);
1165                 HN = Getstr("hn", &cp);
1166                 IM = Getstr("im", &cp);
1167                 if (HN && *HN) {
1168                         (void) strncpy(host_name, HN, sizeof(host_name)-1);
1169                         hostname[sizeof(host_name)-1] = '\0';
1170                 }
1171                 if (IM == 0)
1172                         IM = "";
1173         } else {
1174                 IM = DEFAULT_IM;
1175                 HE = 0;
1176         }
1177         edithost(HE, host_name);
1178         if (hostinfo && *IM)
1179                 putf(IM, ptyibuf2);
1180
1181         if (pcc)
1182                 (void) strncat(ptyibuf2, ptyip, pcc+1);
1183         ptyip = ptyibuf2;
1184         pcc = strlen(ptyip);
1185 #ifdef  LINEMODE
1186         /*
1187          * Last check to make sure all our states are correct.
1188          */
1189         init_termbuf();
1190         localstat();
1191 #endif  /* LINEMODE */
1192
1193         DIAG(TD_REPORT,
1194                 {sprintf(nfrontp, "td: Entering processing loop\r\n");
1195                  nfrontp += strlen(nfrontp);});
1196
1197 #ifdef  convex
1198         startslave(host);
1199 #endif
1200
1201         nfd = ((f > p) ? f : p) + 1;
1202         for (;;) {
1203                 fd_set ibits, obits, xbits;
1204                 register int c;
1205
1206                 if (ncc < 0 && pcc < 0)
1207                         break;
1208
1209 #if     defined(CRAY2) && defined(UNICOS5)
1210                 if (needtermstat)
1211                         _termstat();
1212 #endif  /* defined(CRAY2) && defined(UNICOS5) */
1213                 FD_ZERO(&ibits);
1214                 FD_ZERO(&obits);
1215                 FD_ZERO(&xbits);
1216                 /*
1217                  * Never look for input if there's still
1218                  * stuff in the corresponding output buffer
1219                  */
1220                 if (nfrontp - nbackp || pcc > 0) {
1221                         FD_SET(f, &obits);
1222                 } else {
1223                         FD_SET(p, &ibits);
1224                 }
1225                 if (pfrontp - pbackp || ncc > 0) {
1226                         FD_SET(p, &obits);
1227                 } else {
1228                         FD_SET(f, &ibits);
1229                 }
1230                 if (!SYNCHing) {
1231                         FD_SET(f, &xbits);
1232                 }
1233                 if ((c = select(nfd, &ibits, &obits, &xbits,
1234                                                 (struct timeval *)0)) < 1) {
1235                         if (c == -1) {
1236                                 if (errno == EINTR) {
1237                                         continue;
1238                                 }
1239                         }
1240                         sleep(5);
1241                         continue;
1242                 }
1243
1244                 /*
1245                  * Any urgent data?
1246                  */
1247                 if (FD_ISSET(net, &xbits)) {
1248                     SYNCHing = 1;
1249                 }
1250
1251                 /*
1252                  * Something to read from the network...
1253                  */
1254                 if (FD_ISSET(net, &ibits)) {
1255 #if     !defined(SO_OOBINLINE)
1256                         /*
1257                          * In 4.2 (and 4.3 beta) systems, the
1258                          * OOB indication and data handling in the kernel
1259                          * is such that if two separate TCP Urgent requests
1260                          * come in, one byte of TCP data will be overlaid.
1261                          * This is fatal for Telnet, but we try to live
1262                          * with it.
1263                          *
1264                          * In addition, in 4.2 (and...), a special protocol
1265                          * is needed to pick up the TCP Urgent data in
1266                          * the correct sequence.
1267                          *
1268                          * What we do is:  if we think we are in urgent
1269                          * mode, we look to see if we are "at the mark".
1270                          * If we are, we do an OOB receive.  If we run
1271                          * this twice, we will do the OOB receive twice,
1272                          * but the second will fail, since the second
1273                          * time we were "at the mark", but there wasn't
1274                          * any data there (the kernel doesn't reset
1275                          * "at the mark" until we do a normal read).
1276                          * Once we've read the OOB data, we go ahead
1277                          * and do normal reads.
1278                          *
1279                          * There is also another problem, which is that
1280                          * since the OOB byte we read doesn't put us
1281                          * out of OOB state, and since that byte is most
1282                          * likely the TELNET DM (data mark), we would
1283                          * stay in the TELNET SYNCH (SYNCHing) state.
1284                          * So, clocks to the rescue.  If we've "just"
1285                          * received a DM, then we test for the
1286                          * presence of OOB data when the receive OOB
1287                          * fails (and AFTER we did the normal mode read
1288                          * to clear "at the mark").
1289                          */
1290                     if (SYNCHing) {
1291                         int atmark;
1292
1293                         (void) ioctl(net, SIOCATMARK, (char *)&atmark);
1294                         if (atmark) {
1295                             ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
1296                             if ((ncc == -1) && (errno == EINVAL)) {
1297                                 ncc = read(net, netibuf, sizeof (netibuf));
1298                                 if (sequenceIs(didnetreceive, gotDM)) {
1299                                     SYNCHing = stilloob(net);
1300                                 }
1301                             }
1302                         } else {
1303                             ncc = read(net, netibuf, sizeof (netibuf));
1304                         }
1305                     } else {
1306                         ncc = read(net, netibuf, sizeof (netibuf));
1307                     }
1308                     settimer(didnetreceive);
1309 #else   /* !defined(SO_OOBINLINE)) */
1310                     ncc = read(net, netibuf, sizeof (netibuf));
1311 #endif  /* !defined(SO_OOBINLINE)) */
1312                     if (ncc < 0 && errno == EWOULDBLOCK)
1313                         ncc = 0;
1314                     else {
1315                         if (ncc <= 0) {
1316                             break;
1317                         }
1318                         netip = netibuf;
1319                     }
1320                     DIAG((TD_REPORT | TD_NETDATA),
1321                             {sprintf(nfrontp, "td: netread %d chars\r\n", ncc);
1322                              nfrontp += strlen(nfrontp);});
1323                     DIAG(TD_NETDATA, printdata("nd", netip, ncc));
1324                 }
1325
1326                 /*
1327                  * Something to read from the pty...
1328                  */
1329                 if (FD_ISSET(p, &ibits)) {
1330 #ifndef STREAMSPTY
1331                         pcc = read(p, ptyibuf, BUFSIZ);
1332 #else
1333                         pcc = readstream(p, ptyibuf, BUFSIZ);
1334 #endif
1335                         /*
1336                          * On some systems, if we try to read something
1337                          * off the master side before the slave side is
1338                          * opened, we get EIO.
1339                          */
1340                         if (pcc < 0 && (errno == EWOULDBLOCK ||
1341 #ifdef  EAGAIN
1342                                         errno == EAGAIN ||
1343 #endif
1344                                         errno == EIO)) {
1345                                 pcc = 0;
1346                         } else {
1347                                 if (pcc <= 0)
1348                                         break;
1349 #if     !defined(CRAY2) || !defined(UNICOS5)
1350 #ifdef  LINEMODE
1351                                 /*
1352                                  * If ioctl from pty, pass it through net
1353                                  */
1354                                 if (ptyibuf[0] & TIOCPKT_IOCTL) {
1355                                         copy_termbuf(ptyibuf+1, pcc-1);
1356                                         localstat();
1357                                         pcc = 1;
1358                                 }
1359 #endif  /* LINEMODE */
1360                                 if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
1361                                         netclear();     /* clear buffer back */
1362 #ifndef NO_URGENT
1363                                         /*
1364                                          * There are client telnets on some
1365                                          * operating systems get screwed up
1366                                          * royally if we send them urgent
1367                                          * mode data.
1368                                          */
1369                                         *nfrontp++ = IAC;
1370                                         *nfrontp++ = DM;
1371                                         neturg = nfrontp-1; /* off by one XXX */
1372                                         DIAG(TD_OPTIONS,
1373                                             printoption("td: send IAC", DM));
1374
1375 #endif
1376                                 }
1377                                 if (his_state_is_will(TELOPT_LFLOW) &&
1378                                     (ptyibuf[0] &
1379                                      (TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
1380                                         int newflow =
1381                                             ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
1382                                         if (newflow != flowmode) {
1383                                                 flowmode = newflow;
1384                                                 (void) sprintf(nfrontp,
1385                                                         "%c%c%c%c%c%c",
1386                                                         IAC, SB, TELOPT_LFLOW,
1387                                                         flowmode ? LFLOW_ON
1388                                                                  : LFLOW_OFF,
1389                                                         IAC, SE);
1390                                                 nfrontp += 6;
1391                                                 DIAG(TD_OPTIONS, printsub('>',
1392                                                     (unsigned char *)nfrontp-4,
1393                                                     4););
1394                                         }
1395                                 }
1396                                 pcc--;
1397                                 ptyip = ptyibuf+1;
1398 #else   /* defined(CRAY2) && defined(UNICOS5) */
1399                                 if (!uselinemode) {
1400                                         unpcc = pcc;
1401                                         unptyip = ptyibuf;
1402                                         pcc = term_output(&unptyip, ptyibuf2,
1403                                                                 &unpcc, BUFSIZ);
1404                                         ptyip = ptyibuf2;
1405                                 } else
1406                                         ptyip = ptyibuf;
1407 #endif  /* defined(CRAY2) && defined(UNICOS5) */
1408                         }
1409                 }
1410
1411                 while (pcc > 0) {
1412                         if ((&netobuf[BUFSIZ] - nfrontp) < 2)
1413                                 break;
1414                         c = *ptyip++ & 0377, pcc--;
1415                         if (c == IAC)
1416                                 *nfrontp++ = c;
1417 #if     defined(CRAY2) && defined(UNICOS5)
1418                         else if (c == '\n' &&
1419                                      my_state_is_wont(TELOPT_BINARY) && newmap)
1420                                 *nfrontp++ = '\r';
1421 #endif  /* defined(CRAY2) && defined(UNICOS5) */
1422                         *nfrontp++ = c;
1423                         if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
1424                                 if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
1425                                         *nfrontp++ = *ptyip++ & 0377;
1426                                         pcc--;
1427                                 } else
1428                                         *nfrontp++ = '\0';
1429                         }
1430                 }
1431 #if     defined(CRAY2) && defined(UNICOS5)
1432                 /*
1433                  * If chars were left over from the terminal driver,
1434                  * note their existence.
1435                  */
1436                 if (!uselinemode && unpcc) {
1437                         pcc = unpcc;
1438                         unpcc = 0;
1439                         ptyip = unptyip;
1440                 }
1441 #endif  /* defined(CRAY2) && defined(UNICOS5) */
1442
1443                 if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
1444                         netflush();
1445                 if (ncc > 0)
1446                         telrcv();
1447                 if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
1448                         ptyflush();
1449         }
1450         cleanup(0);
1451 }  /* end of telnet */
1452
1453 #ifndef TCSIG
1454 # ifdef TIOCSIG
1455 #  define TCSIG TIOCSIG
1456 # endif
1457 #endif
1458
1459 #ifdef  STREAMSPTY
1460
1461 int flowison = -1;  /* current state of flow: -1 is unknown */
1462
1463 int readstream(p, ibuf, bufsize)
1464         int p;
1465         char *ibuf;
1466         int bufsize;
1467 {
1468         int flags = 0;
1469         int ret = 0;
1470         struct termios *tsp;
1471         struct termio *tp;
1472         struct iocblk *ip;
1473         char vstop, vstart;
1474         int ixon;
1475         int newflow;
1476
1477         strbufc.maxlen = BUFSIZ;
1478         strbufc.buf = (char *)ctlbuf;
1479         strbufd.maxlen = bufsize-1;
1480         strbufd.len = 0;
1481         strbufd.buf = ibuf+1;
1482         ibuf[0] = 0;
1483
1484         ret = getmsg(p, &strbufc, &strbufd, &flags);
1485         if (ret < 0)  /* error of some sort -- probably EAGAIN */
1486                 return(-1);
1487
1488         if (strbufc.len <= 0 || ctlbuf[0] == M_DATA) {
1489                 /* data message */
1490                 if (strbufd.len > 0) {                  /* real data */
1491                         return(strbufd.len + 1);        /* count header char */
1492                 } else {
1493                         /* nothing there */
1494                         errno = EAGAIN;
1495                         return(-1);
1496                 }
1497         }
1498
1499         /*
1500          * It's a control message.  Return 1, to look at the flag we set
1501          */
1502
1503         switch (ctlbuf[0]) {
1504         case M_FLUSH:
1505                 if (ibuf[1] & FLUSHW)
1506                         ibuf[0] = TIOCPKT_FLUSHWRITE;
1507                 return(1);
1508
1509         case M_IOCTL:
1510                 ip = (struct iocblk *) (ibuf+1);
1511
1512                 switch (ip->ioc_cmd) {
1513                 case TCSETS:
1514                 case TCSETSW:
1515                 case TCSETSF:
1516                         tsp = (struct termios *)
1517                                         (ibuf+1 + sizeof(struct iocblk));
1518                         vstop = tsp->c_cc[VSTOP];
1519                         vstart = tsp->c_cc[VSTART];
1520                         ixon = tsp->c_iflag & IXON;
1521                         break;
1522                 case TCSETA:
1523                 case TCSETAW:
1524                 case TCSETAF:
1525                         tp = (struct termio *) (ibuf+1 + sizeof(struct iocblk));
1526                         vstop = tp->c_cc[VSTOP];
1527                         vstart = tp->c_cc[VSTART];
1528                         ixon = tp->c_iflag & IXON;
1529                         break;
1530                 default:
1531                         errno = EAGAIN;
1532                         return(-1);
1533                 }
1534
1535                 newflow =  (ixon && (vstart == 021) && (vstop == 023)) ? 1 : 0;
1536                 if (newflow != flowison) {  /* it's a change */
1537                         flowison = newflow;
1538                         ibuf[0] = newflow ? TIOCPKT_DOSTOP : TIOCPKT_NOSTOP;
1539                         return(1);
1540                 }
1541         }
1542
1543         /* nothing worth doing anything about */
1544         errno = EAGAIN;
1545         return(-1);
1546 }
1547 #endif /* STREAMSPTY */
1548
1549 /*
1550  * Send interrupt to process on other side of pty.
1551  * If it is in raw mode, just write NULL;
1552  * otherwise, write intr char.
1553  */
1554         void
1555 interrupt()
1556 {
1557         ptyflush();     /* half-hearted */
1558
1559 #if defined(STREAMSPTY) && defined(TIOCSIGNAL)
1560         /* Streams PTY style ioctl to post a signal */
1561         {
1562                 int sig = SIGINT;
1563                 (void) ioctl(pty, TIOCSIGNAL, &sig);
1564                 (void) ioctl(pty, I_FLUSH, FLUSHR);
1565         }
1566 #else
1567 #ifdef  TCSIG
1568         (void) ioctl(pty, TCSIG, (char *)SIGINT);
1569 #else   /* TCSIG */
1570         init_termbuf();
1571         *pfrontp++ = slctab[SLC_IP].sptr ?
1572                         (unsigned char)*slctab[SLC_IP].sptr : '\177';
1573 #endif  /* TCSIG */
1574 #endif
1575 }
1576
1577 /*
1578  * Send quit to process on other side of pty.
1579  * If it is in raw mode, just write NULL;
1580  * otherwise, write quit char.
1581  */
1582         void
1583 sendbrk()
1584 {
1585         ptyflush();     /* half-hearted */
1586 #ifdef  TCSIG
1587         (void) ioctl(pty, TCSIG, (char *)SIGQUIT);
1588 #else   /* TCSIG */
1589         init_termbuf();
1590         *pfrontp++ = slctab[SLC_ABORT].sptr ?
1591                         (unsigned char)*slctab[SLC_ABORT].sptr : '\034';
1592 #endif  /* TCSIG */
1593 }
1594
1595         void
1596 sendsusp()
1597 {
1598 #ifdef  SIGTSTP
1599         ptyflush();     /* half-hearted */
1600 # ifdef TCSIG
1601         (void) ioctl(pty, TCSIG, (char *)SIGTSTP);
1602 # else  /* TCSIG */
1603         *pfrontp++ = slctab[SLC_SUSP].sptr ?
1604                         (unsigned char)*slctab[SLC_SUSP].sptr : '\032';
1605 # endif /* TCSIG */
1606 #endif  /* SIGTSTP */
1607 }
1608
1609 /*
1610  * When we get an AYT, if ^T is enabled, use that.  Otherwise,
1611  * just send back "[Yes]".
1612  */
1613         void
1614 recv_ayt()
1615 {
1616 #if     defined(SIGINFO) && defined(TCSIG)
1617         if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
1618                 (void) ioctl(pty, TCSIG, (char *)SIGINFO);
1619                 return;
1620         }
1621 #endif
1622         (void) strcpy(nfrontp, "\r\n[Yes]\r\n");
1623         nfrontp += 9;
1624 }
1625
1626         void
1627 doeof()
1628 {
1629         init_termbuf();
1630
1631 #if     defined(LINEMODE) && defined(USE_TERMIO) && (VEOF == VMIN)
1632         if (!tty_isediting()) {
1633                 extern char oldeofc;
1634                 *pfrontp++ = oldeofc;
1635                 return;
1636         }
1637 #endif
1638         *pfrontp++ = slctab[SLC_EOF].sptr ?
1639                         (unsigned char)*slctab[SLC_EOF].sptr : '\004';
1640 }