usr.bin/telnet/telnet.c

   1 /*
   2  * Copyright (c) 1988, 1990, 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  * @(#)telnet.c 8.4 (Berkeley) 5/30/95
  34  * $FreeBSD: src/crypto/telnet/telnet/telnet.c,v 1.4.2.5 2002/04/13 10:59:08 markm Exp $
  35  * $DragonFly: src/crypto/telnet/telnet/telnet.c,v 1.3 2005/03/28 18:03:32 drhodus Exp $
  36  */
  37
  38 #include <sys/types.h>
  39
  40 /* By the way, we need to include curses.h before telnet.h since,
  41  * among other things, telnet.h #defines 'DO', which is a variable
  42  * declared in curses.h.
  43  */
  44
  45 #include <ctype.h>
  46 #include <curses.h>
  47 #include <signal.h>
  48 #include <stdlib.h>
  49 #include <term.h>
  50 #include <unistd.h>
  51 #include <arpa/telnet.h>
  52
  53 #include "ring.h"
  54
  55 #include "defines.h"
  56 #include "externs.h"
  57 #include "types.h"
  58 #include "general.h"
  59
  60 #ifdef  AUTHENTICATION
  61 #include <libtelnet/auth.h>
  62 #endif
  63 #ifdef  ENCRYPTION
  64 #include <libtelnet/encrypt.h>
  65 #endif
  66 #include <libtelnet/misc.h>
  67 \f
  68 #define strip(x) ((my_want_state_is_wont(TELOPT_BINARY)) ? ((x)&0x7f) : (x))
  69
  70 static unsigned char    subbuffer[SUBBUFSIZE],
  71                         *subpointer, *subend;    /* buffer for sub-options */
  72 #define SB_CLEAR()      subpointer = subbuffer;
  73 #define SB_TERM()       { subend = subpointer; SB_CLEAR(); }
  74 #define SB_ACCUM(c)     if (subpointer < (subbuffer+sizeof subbuffer)) { \
  75                                 *subpointer++ = (c); \
  76                         }
  77
  78 #define SB_GET()        ((*subpointer++)&0xff)
  79 #define SB_PEEK()       ((*subpointer)&0xff)
  80 #define SB_EOF()        (subpointer >= subend)
  81 #define SB_LEN()        (subend - subpointer)
  82
  83 char    options[256];           /* The combined options */
  84 char    do_dont_resp[256];
  85 char    will_wont_resp[256];
  86
  87 int
  88         eight = 0,
  89         autologin = 0,  /* Autologin anyone? */
  90         skiprc = 0,
  91         connected,
  92         showoptions,
  93         ISend,          /* trying to send network data in */
  94         debug = 0,
  95         crmod,
  96         netdata,        /* Print out network data flow */
  97         crlf,           /* Should '\r' be mapped to <CR><LF> (or <CR><NUL>)? */
  98         telnetport,
  99         SYNCHing,       /* we are in TELNET SYNCH mode */
 100         flushout,       /* flush output */
 101         autoflush = 0,  /* flush output when interrupting? */
 102         autosynch,      /* send interrupt characters with SYNCH? */
 103         localflow,      /* we handle flow control locally */
 104         restartany,     /* if flow control enabled, restart on any character */
 105         localchars,     /* we recognize interrupt/quit */
 106         donelclchars,   /* the user has set "localchars" */
 107         donebinarytoggle,       /* the user has put us in binary */
 108         dontlecho,      /* do we suppress local echoing right now? */
 109         globalmode,
 110         doaddrlookup = 1, /* do a reverse address lookup? */
 111         clienteof = 0;
 112
 113 char *prompt = 0;
 114 #ifdef ENCRYPTION
 115 char *line;             /* hack around breakage in sra.c :-( !! */
 116 #endif
 117
 118 cc_t escape;
 119 cc_t rlogin;
 120 #ifdef  KLUDGELINEMODE
 121 cc_t echoc;
 122 #endif
 123
 124 /*
 125  * Telnet receiver states for fsm
 126  */
 127 #define TS_DATA         0
 128 #define TS_IAC          1
 129 #define TS_WILL         2
 130 #define TS_WONT         3
 131 #define TS_DO           4
 132 #define TS_DONT         5
 133 #define TS_CR           6
 134 #define TS_SB           7               /* sub-option collection */
 135 #define TS_SE           8               /* looking for sub-option end */
 136
 137 static int      telrcv_state;
 138 #ifdef  OLD_ENVIRON
 139 unsigned char telopt_environ = TELOPT_NEW_ENVIRON;
 140 #else
 141 # define telopt_environ TELOPT_NEW_ENVIRON
 142 #endif
 143
 144 jmp_buf toplevel;
 145 jmp_buf peerdied;
 146
 147 int     flushline;
 148 int     linemode;
 149
 150 #ifdef  KLUDGELINEMODE
 151 int     kludgelinemode = 1;
 152 #endif
 153
 154 static int is_unique(char *, char **, char **);
 155
 156 /*
 157  * The following are some clocks used to decide how to interpret
 158  * the relationship between various variables.
 159  */
 160
 161 Clocks clocks;
 162 \f
 163 /*
 164  * Initialize telnet environment.
 165  */
 166
 167 void
 168 init_telnet(void)
 169 {
 170     env_init();
 171
 172     SB_CLEAR();
 173     ClearArray(options);
 174
 175     connected = ISend = localflow = donebinarytoggle = 0;
 176 #ifdef  AUTHENTICATION
 177 #ifdef  ENCRYPTION
 178     auth_encrypt_connect(connected);
 179 #endif
 180 #endif
 181     restartany = -1;
 182
 183     SYNCHing = 0;
 184
 185     /* Don't change NetTrace */
 186
 187     escape = CONTROL(']');
 188     rlogin = _POSIX_VDISABLE;
 189 #ifdef  KLUDGELINEMODE
 190     echoc = CONTROL('E');
 191 #endif
 192
 193     flushline = 1;
 194     telrcv_state = TS_DATA;
 195 }
 196 \f
 197
 198 /*
 199  * These routines are in charge of sending option negotiations
 200  * to the other side.
 201  *
 202  * The basic idea is that we send the negotiation if either side
 203  * is in disagreement as to what the current state should be.
 204  */
 205
 206 void
 207 send_do(int c, int init)
 208 {
 209     if (init) {
 210         if (((do_dont_resp[c] == 0) && my_state_is_do(c)) ||
 211                                 my_want_state_is_do(c))
 212             return;
 213         set_my_want_state_do(c);
 214         do_dont_resp[c]++;
 215     }
 216     NET2ADD(IAC, DO);
 217     NETADD(c);
 218     printoption("SENT", DO, c);
 219 }
 220
 221 void
 222 send_dont(int c, int init)
 223 {
 224     if (init) {
 225         if (((do_dont_resp[c] == 0) && my_state_is_dont(c)) ||
 226                                 my_want_state_is_dont(c))
 227             return;
 228         set_my_want_state_dont(c);
 229         do_dont_resp[c]++;
 230     }
 231     NET2ADD(IAC, DONT);
 232     NETADD(c);
 233     printoption("SENT", DONT, c);
 234 }
 235
 236 void
 237 send_will(int c, int init)
 238 {
 239     if (init) {
 240         if (((will_wont_resp[c] == 0) && my_state_is_will(c)) ||
 241                                 my_want_state_is_will(c))
 242             return;
 243         set_my_want_state_will(c);
 244         will_wont_resp[c]++;
 245     }
 246     NET2ADD(IAC, WILL);
 247     NETADD(c);
 248     printoption("SENT", WILL, c);
 249 }
 250
 251 void
 252 send_wont(int c, int init)
 253 {
 254     if (init) {
 255         if (((will_wont_resp[c] == 0) && my_state_is_wont(c)) ||
 256                                 my_want_state_is_wont(c))
 257             return;
 258         set_my_want_state_wont(c);
 259         will_wont_resp[c]++;
 260     }
 261     NET2ADD(IAC, WONT);
 262     NETADD(c);
 263     printoption("SENT", WONT, c);
 264 }
 265
 266 void
 267 willoption(int option)
 268 {
 269         int new_state_ok = 0;
 270
 271         if (do_dont_resp[option]) {
 272             --do_dont_resp[option];
 273             if (do_dont_resp[option] && my_state_is_do(option))
 274                 --do_dont_resp[option];
 275         }
 276
 277         if ((do_dont_resp[option] == 0) && my_want_state_is_dont(option)) {
 278
 279             switch (option) {
 280
 281             case TELOPT_ECHO:
 282             case TELOPT_BINARY:
 283             case TELOPT_SGA:
 284                 settimer(modenegotiated);
 285                 /* FALL THROUGH */
 286             case TELOPT_STATUS:
 287 #ifdef  AUTHENTICATION
 288             case TELOPT_AUTHENTICATION:
 289 #endif
 290 #ifdef  ENCRYPTION
 291             case TELOPT_ENCRYPT:
 292 #endif /* ENCRYPTION */
 293                 new_state_ok = 1;
 294                 break;
 295
 296             case TELOPT_TM:
 297                 if (flushout)
 298                     flushout = 0;
 299                 /*
 300                  * Special case for TM.  If we get back a WILL,
 301                  * pretend we got back a WONT.
 302                  */
 303                 set_my_want_state_dont(option);
 304                 set_my_state_dont(option);
 305                 return;                 /* Never reply to TM will's/wont's */
 306
 307             case TELOPT_LINEMODE:
 308             default:
 309                 break;
 310             }
 311
 312             if (new_state_ok) {
 313                 set_my_want_state_do(option);
 314                 send_do(option, 0);
 315                 setconnmode(0);         /* possibly set new tty mode */
 316             } else {
 317                 do_dont_resp[option]++;
 318                 send_dont(option, 0);
 319             }
 320         }
 321         set_my_state_do(option);
 322 #ifdef  ENCRYPTION
 323         if (option == TELOPT_ENCRYPT)
 324                 encrypt_send_support();
 325 #endif  /* ENCRYPTION */
 326 }
 327
 328 void
 329 wontoption(int option)
 330 {
 331         if (do_dont_resp[option]) {
 332             --do_dont_resp[option];
 333             if (do_dont_resp[option] && my_state_is_dont(option))
 334                 --do_dont_resp[option];
 335         }
 336
 337         if ((do_dont_resp[option] == 0) && my_want_state_is_do(option)) {
 338
 339             switch (option) {
 340
 341 #ifdef  KLUDGELINEMODE
 342             case TELOPT_SGA:
 343                 if (!kludgelinemode)
 344                     break;
 345                 /* FALL THROUGH */
 346 #endif
 347             case TELOPT_ECHO:
 348                 settimer(modenegotiated);
 349                 break;
 350
 351             case TELOPT_TM:
 352                 if (flushout)
 353                     flushout = 0;
 354                 set_my_want_state_dont(option);
 355                 set_my_state_dont(option);
 356                 return;         /* Never reply to TM will's/wont's */
 357
 358             default:
 359                 break;
 360             }
 361             set_my_want_state_dont(option);
 362             if (my_state_is_do(option))
 363                 send_dont(option, 0);
 364             setconnmode(0);                     /* Set new tty mode */
 365         } else if (option == TELOPT_TM) {
 366             /*
 367              * Special case for TM.
 368              */
 369             if (flushout)
 370                 flushout = 0;
 371             set_my_want_state_dont(option);
 372         }
 373         set_my_state_dont(option);
 374 }
 375
 376 static void
 377 dooption(int option)
 378 {
 379         int new_state_ok = 0;
 380
 381         if (will_wont_resp[option]) {
 382             --will_wont_resp[option];
 383             if (will_wont_resp[option] && my_state_is_will(option))
 384                 --will_wont_resp[option];
 385         }
 386
 387         if (will_wont_resp[option] == 0) {
 388           if (my_want_state_is_wont(option)) {
 389
 390             switch (option) {
 391
 392             case TELOPT_TM:
 393                 /*
 394                  * Special case for TM.  We send a WILL, but pretend
 395                  * we sent WONT.
 396                  */
 397                 send_will(option, 0);
 398                 set_my_want_state_wont(TELOPT_TM);
 399                 set_my_state_wont(TELOPT_TM);
 400                 return;
 401
 402             case TELOPT_BINARY:         /* binary mode */
 403             case TELOPT_NAWS:           /* window size */
 404             case TELOPT_TSPEED:         /* terminal speed */
 405             case TELOPT_LFLOW:          /* local flow control */
 406             case TELOPT_TTYPE:          /* terminal type option */
 407             case TELOPT_SGA:            /* no big deal */
 408 #ifdef  ENCRYPTION
 409             case TELOPT_ENCRYPT:        /* encryption variable option */
 410 #endif  /* ENCRYPTION */
 411                 new_state_ok = 1;
 412                 break;
 413
 414             case TELOPT_NEW_ENVIRON:    /* New environment variable option */
 415 #ifdef  OLD_ENVIRON
 416                 if (my_state_is_will(TELOPT_OLD_ENVIRON))
 417                         send_wont(TELOPT_OLD_ENVIRON, 1); /* turn off the old */
 418                 goto env_common;
 419             case TELOPT_OLD_ENVIRON:    /* Old environment variable option */
 420                 if (my_state_is_will(TELOPT_NEW_ENVIRON))
 421                         break;          /* Don't enable if new one is in use! */
 422             env_common:
 423                 telopt_environ = option;
 424 #endif
 425                 new_state_ok = 1;
 426                 break;
 427
 428 #ifdef  AUTHENTICATION
 429             case TELOPT_AUTHENTICATION:
 430                 if (autologin)
 431                         new_state_ok = 1;
 432                 break;
 433 #endif
 434
 435             case TELOPT_XDISPLOC:       /* X Display location */
 436                 if (env_getvalue("DISPLAY"))
 437                     new_state_ok = 1;
 438                 break;
 439
 440             case TELOPT_LINEMODE:
 441 #ifdef  KLUDGELINEMODE
 442                 kludgelinemode = 0;
 443                 send_do(TELOPT_SGA, 1);
 444 #endif
 445                 set_my_want_state_will(TELOPT_LINEMODE);
 446                 send_will(option, 0);
 447                 set_my_state_will(TELOPT_LINEMODE);
 448                 slc_init();
 449                 return;
 450
 451             case TELOPT_ECHO:           /* We're never going to echo... */
 452             default:
 453                 break;
 454             }
 455
 456             if (new_state_ok) {
 457                 set_my_want_state_will(option);
 458                 send_will(option, 0);
 459                 setconnmode(0);                 /* Set new tty mode */
 460             } else {
 461                 will_wont_resp[option]++;
 462                 send_wont(option, 0);
 463             }
 464           } else {
 465             /*
 466              * Handle options that need more things done after the
 467              * other side has acknowledged the option.
 468              */
 469             switch (option) {
 470             case TELOPT_LINEMODE:
 471 #ifdef  KLUDGELINEMODE
 472                 kludgelinemode = 0;
 473                 send_do(TELOPT_SGA, 1);
 474 #endif
 475                 set_my_state_will(option);
 476                 slc_init();
 477                 send_do(TELOPT_SGA, 0);
 478                 return;
 479             }
 480           }
 481         }
 482         set_my_state_will(option);
 483 }
 484
 485 static void
 486 dontoption(int option)
 487 {
 488
 489         if (will_wont_resp[option]) {
 490             --will_wont_resp[option];
 491             if (will_wont_resp[option] && my_state_is_wont(option))
 492                 --will_wont_resp[option];
 493         }
 494
 495         if ((will_wont_resp[option] == 0) && my_want_state_is_will(option)) {
 496             switch (option) {
 497             case TELOPT_LINEMODE:
 498                 linemode = 0;   /* put us back to the default state */
 499                 break;
 500 #ifdef  OLD_ENVIRON
 501             case TELOPT_NEW_ENVIRON:
 502                 /*
 503                  * The new environ option wasn't recognized, try
 504                  * the old one.
 505                  */
 506                 send_will(TELOPT_OLD_ENVIRON, 1);
 507                 telopt_environ = TELOPT_OLD_ENVIRON;
 508                 break;
 509 #endif
 510             }
 511             /* we always accept a DONT */
 512             set_my_want_state_wont(option);
 513             if (my_state_is_will(option))
 514                 send_wont(option, 0);
 515             setconnmode(0);                     /* Set new tty mode */
 516         }
 517         set_my_state_wont(option);
 518 }
 519
 520 /*
 521  * Given a buffer returned by tgetent(), this routine will turn
 522  * the pipe separated list of names in the buffer into an array
 523  * of pointers to null terminated names.  We toss out any bad,
 524  * duplicate, or verbose names (names with spaces).
 525  */
 526
 527 static const char *name_unknown = "UNKNOWN";
 528 static const char *unknown[] = { NULL, NULL };
 529
 530 static const char **
 531 mklist(char *buf, char *name)
 532 {
 533         int n;
 534         char c, *cp, **argvp, *cp2, **argv, **avt;
 535
 536         if (name) {
 537                 if (strlen(name) > 40) {
 538                         name = 0;
 539                         unknown[0] = name_unknown;
 540                 } else {
 541                         unknown[0] = name;
 542                         upcase(name);
 543                 }
 544         } else
 545                 unknown[0] = name_unknown;
 546         /*
 547          * Count up the number of names.
 548          */
 549         for (n = 1, cp = buf; *cp && *cp != ':'; cp++) {
 550                 if (*cp == '|')
 551                         n++;
 552         }
 553         /*
 554          * Allocate an array to put the name pointers into
 555          */
 556         argv = (char **)malloc((n+3)*sizeof(char *));
 557         if (argv == 0)
 558                 return(unknown);
 559
 560         /*
 561          * Fill up the array of pointers to names.
 562          */
 563         *argv = 0;
 564         argvp = argv+1;
 565         n = 0;
 566         for (cp = cp2 = buf; (c = *cp);  cp++) {
 567                 if (c == '|' || c == ':') {
 568                         *cp++ = '\0';
 569                         /*
 570                          * Skip entries that have spaces or are over 40
 571                          * characters long.  If this is our environment
 572                          * name, then put it up front.  Otherwise, as
 573                          * long as this is not a duplicate name (case
 574                          * insensitive) add it to the list.
 575                          */
 576                         if (n || (cp - cp2 > 41))
 577                                 ;
 578                         else if (name && (strncasecmp(name, cp2, cp-cp2) == 0))
 579                                 *argv = cp2;
 580                         else if (is_unique(cp2, argv+1, argvp))
 581                                 *argvp++ = cp2;
 582                         if (c == ':')
 583                                 break;
 584                         /*
 585                          * Skip multiple delimiters. Reset cp2 to
 586                          * the beginning of the next name. Reset n,
 587                          * the flag for names with spaces.
 588                          */
 589                         while ((c = *cp) == '|')
 590                                 cp++;
 591                         cp2 = cp;
 592                         n = 0;
 593                 }
 594                 /*
 595                  * Skip entries with spaces or non-ascii values.
 596                  * Convert lower case letters to upper case.
 597                  */
 598                 if ((c == ' ') || !isascii(c))
 599                         n = 1;
 600                 else if (islower(c))
 601                         *cp = toupper(c);
 602         }
 603
 604         /*
 605          * Check for an old V6 2 character name.  If the second
 606          * name points to the beginning of the buffer, and is
 607          * only 2 characters long, move it to the end of the array.
 608          */
 609         if ((argv[1] == buf) && (strlen(argv[1]) == 2)) {
 610                 --argvp;
 611                 for (avt = &argv[1]; avt < argvp; avt++)
 612                         *avt = *(avt+1);
 613                 *argvp++ = buf;
 614         }
 615
 616         /*
 617          * Duplicate last name, for TTYPE option, and null
 618          * terminate the array.  If we didn't find a match on
 619          * our terminal name, put that name at the beginning.
 620          */
 621         cp = *(argvp-1);
 622         *argvp++ = cp;
 623         *argvp = 0;
 624
 625         if (*argv == 0) {
 626                 if (name)
 627                         *argv = name;
 628                 else {
 629                         --argvp;
 630                         for (avt = argv; avt < argvp; avt++)
 631                                 *avt = *(avt+1);
 632                 }
 633         }
 634         if (*argv)
 635                 return((const char **)argv);
 636         else
 637                 return(unknown);
 638 }
 639
 640 static int
 641 is_unique(char *name, char **as, char **ae)
 642 {
 643         char **ap;
 644         int n;
 645
 646         n = strlen(name) + 1;
 647         for (ap = as; ap < ae; ap++)
 648                 if (strncasecmp(*ap, name, n) == 0)
 649                         return(0);
 650         return (1);
 651 }
 652
 653 #ifdef  TERMCAP
 654 char termbuf[1024];
 655
 656 /*ARGSUSED*/
 657 static int
 658 setupterm(char *tname, int fd, int *errp)
 659 {
 660         if (tgetent(termbuf, tname) == 1) {
 661                 termbuf[1023] = '\0';
 662                 if (errp)
 663                         *errp = 1;
 664                 return(0);
 665         }
 666         if (errp)
 667                 *errp = 0;
 668         return(-1);
 669 }
 670 #else
 671 #define termbuf ttytype
 672 extern char ttytype[];
 673 #endif
 674
 675 int resettermname = 1;
 676
 677 static const char *
 678 gettermname(void)
 679 {
 680         char *tname;
 681         static const char **tnamep = 0;
 682         static const char **next;
 683         int err;
 684
 685         if (resettermname) {
 686                 resettermname = 0;
 687                 if (tnamep && tnamep != unknown)
 688                         free(tnamep);
 689                 if ((tname = env_getvalue("TERM")) &&
 690                                 (setupterm(tname, 1, &err) == 0)) {
 691                         tnamep = mklist(termbuf, tname);
 692                 } else {
 693                         if (tname && (strlen(tname) <= 40)) {
 694                                 unknown[0] = tname;
 695                                 upcase(tname);
 696                         } else
 697                                 unknown[0] = name_unknown;
 698                         tnamep = unknown;
 699                 }
 700                 next = tnamep;
 701         }
 702         if (*next == 0)
 703                 next = tnamep;
 704         return(*next++);
 705 }
 706 /*
 707  * suboption()
 708  *
 709  *      Look at the sub-option buffer, and try to be helpful to the other
 710  * side.
 711  *
 712  *      Currently we recognize:
 713  *
 714  *              Terminal type, send request.
 715  *              Terminal speed (send request).
 716  *              Local flow control (is request).
 717  *              Linemode
 718  */
 719
 720 static void
 721 suboption(void)
 722 {
 723     unsigned char subchar;
 724
 725     printsub('<', subbuffer, SB_LEN()+2);
 726     switch (subchar = SB_GET()) {
 727     case TELOPT_TTYPE:
 728         if (my_want_state_is_wont(TELOPT_TTYPE))
 729             return;
 730         if (SB_EOF() || SB_GET() != TELQUAL_SEND) {
 731             return;
 732         } else {
 733             const char *name;
 734             unsigned char temp[50];
 735             int len;
 736
 737             name = gettermname();
 738             len = strlen(name) + 4 + 2;
 739             if (len < NETROOM()) {
 740                 sprintf(temp, "%c%c%c%c%s%c%c", IAC, SB, TELOPT_TTYPE,
 741                                 TELQUAL_IS, name, IAC, SE);
 742                 ring_supply_data(&netoring, temp, len);
 743                 printsub('>', &temp[2], len-2);
 744             } else {
 745                 ExitString("No room in buffer for terminal type.\n", 1);
 746                 /*NOTREACHED*/
 747             }
 748         }
 749         break;
 750     case TELOPT_TSPEED:
 751         if (my_want_state_is_wont(TELOPT_TSPEED))
 752             return;
 753         if (SB_EOF())
 754             return;
 755         if (SB_GET() == TELQUAL_SEND) {
 756             long ospeed, ispeed;
 757             unsigned char temp[50];
 758             int len;
 759
 760             TerminalSpeeds(&ispeed, &ospeed);
 761
 762             sprintf((char *)temp, "%c%c%c%c%ld,%ld%c%c", IAC, SB, TELOPT_TSPEED,
 763                     TELQUAL_IS, ospeed, ispeed, IAC, SE);
 764             len = strlen((char *)temp+4) + 4;   /* temp[3] is 0 ... */
 765
 766             if (len < NETROOM()) {
 767                 ring_supply_data(&netoring, temp, len);
 768                 printsub('>', temp+2, len - 2);
 769             }
 770 /*@*/       else printf("lm_will: not enough room in buffer\n");
 771         }
 772         break;
 773     case TELOPT_LFLOW:
 774         if (my_want_state_is_wont(TELOPT_LFLOW))
 775             return;
 776         if (SB_EOF())
 777             return;
 778         switch(SB_GET()) {
 779         case LFLOW_RESTART_ANY:
 780             restartany = 1;
 781             break;
 782         case LFLOW_RESTART_XON:
 783             restartany = 0;
 784             break;
 785         case LFLOW_ON:
 786             localflow = 1;
 787             break;
 788         case LFLOW_OFF:
 789             localflow = 0;
 790             break;
 791         default:
 792             return;
 793         }
 794         setcommandmode();
 795         setconnmode(0);
 796         break;
 797
 798     case TELOPT_LINEMODE:
 799         if (my_want_state_is_wont(TELOPT_LINEMODE))
 800             return;
 801         if (SB_EOF())
 802             return;
 803         switch (SB_GET()) {
 804         case WILL:
 805             lm_will(subpointer, SB_LEN());
 806             break;
 807         case WONT:
 808             lm_wont(subpointer, SB_LEN());
 809             break;
 810         case DO:
 811             lm_do(subpointer, SB_LEN());
 812             break;
 813         case DONT:
 814             lm_dont(subpointer, SB_LEN());
 815             break;
 816         case LM_SLC:
 817             slc(subpointer, SB_LEN());
 818             break;
 819         case LM_MODE:
 820             lm_mode(subpointer, SB_LEN(), 0);
 821             break;
 822         default:
 823             break;
 824         }
 825         break;
 826
 827 #ifdef  OLD_ENVIRON
 828     case TELOPT_OLD_ENVIRON:
 829 #endif
 830     case TELOPT_NEW_ENVIRON:
 831         if (SB_EOF())
 832             return;
 833         switch(SB_PEEK()) {
 834         case TELQUAL_IS:
 835         case TELQUAL_INFO:
 836             if (my_want_state_is_dont(subchar))
 837                 return;
 838             break;
 839         case TELQUAL_SEND:
 840             if (my_want_state_is_wont(subchar)) {
 841                 return;
 842             }
 843             break;
 844         default:
 845             return;
 846         }
 847         env_opt(subpointer, SB_LEN());
 848         break;
 849
 850     case TELOPT_XDISPLOC:
 851         if (my_want_state_is_wont(TELOPT_XDISPLOC))
 852             return;
 853         if (SB_EOF())
 854             return;
 855         if (SB_GET() == TELQUAL_SEND) {
 856             unsigned char temp[50], *dp;
 857             int len;
 858
 859             if ((dp = env_getvalue("DISPLAY")) == NULL ||
 860                 strlen(dp) > sizeof(temp) - 7) {
 861                 /*
 862                  * Something happened, we no longer have a DISPLAY
 863                  * variable.  Or it is too long.  So, turn off the option.
 864                  */
 865                 send_wont(TELOPT_XDISPLOC, 1);
 866                 break;
 867             }
 868             snprintf(temp, sizeof(temp), "%c%c%c%c%s%c%c", IAC, SB,
 869                     TELOPT_XDISPLOC, TELQUAL_IS, dp, IAC, SE);
 870             len = strlen((char *)temp+4) + 4;   /* temp[3] is 0 ... */
 871
 872             if (len < NETROOM()) {
 873                 ring_supply_data(&netoring, temp, len);
 874                 printsub('>', temp+2, len - 2);
 875             }
 876 /*@*/       else printf("lm_will: not enough room in buffer\n");
 877         }
 878         break;
 879
 880 #ifdef  AUTHENTICATION
 881         case TELOPT_AUTHENTICATION: {
 882                 if (!autologin)
 883                         break;
 884                 if (SB_EOF())
 885                         return;
 886                 switch(SB_GET()) {
 887                 case TELQUAL_IS:
 888                         if (my_want_state_is_dont(TELOPT_AUTHENTICATION))
 889                                 return;
 890                         auth_is(subpointer, SB_LEN());
 891                         break;
 892                 case TELQUAL_SEND:
 893                         if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
 894                                 return;
 895                         auth_send(subpointer, SB_LEN());
 896                         break;
 897                 case TELQUAL_REPLY:
 898                         if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
 899                                 return;
 900                         auth_reply(subpointer, SB_LEN());
 901                         break;
 902                 case TELQUAL_NAME:
 903                         if (my_want_state_is_dont(TELOPT_AUTHENTICATION))
 904                                 return;
 905                         auth_name(subpointer, SB_LEN());
 906                         break;
 907                 }
 908         }
 909         break;
 910 #endif
 911 #ifdef  ENCRYPTION
 912         case TELOPT_ENCRYPT:
 913                 if (SB_EOF())
 914                         return;
 915                 switch(SB_GET()) {
 916                 case ENCRYPT_START:
 917                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 918                                 return;
 919                         encrypt_start(subpointer, SB_LEN());
 920                         break;
 921                 case ENCRYPT_END:
 922                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 923                                 return;
 924                         encrypt_end();
 925                         break;
 926                 case ENCRYPT_SUPPORT:
 927                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 928                                 return;
 929                         encrypt_support(subpointer, SB_LEN());
 930                         break;
 931                 case ENCRYPT_REQSTART:
 932                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 933                                 return;
 934                         encrypt_request_start(subpointer, SB_LEN());
 935                         break;
 936                 case ENCRYPT_REQEND:
 937                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 938                                 return;
 939                         /*
 940                          * We can always send an REQEND so that we cannot
 941                          * get stuck encrypting.  We should only get this
 942                          * if we have been able to get in the correct mode
 943                          * anyhow.
 944                          */
 945                         encrypt_request_end();
 946                         break;
 947                 case ENCRYPT_IS:
 948                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 949                                 return;
 950                         encrypt_is(subpointer, SB_LEN());
 951                         break;
 952                 case ENCRYPT_REPLY:
 953                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 954                                 return;
 955                         encrypt_reply(subpointer, SB_LEN());
 956                         break;
 957                 case ENCRYPT_ENC_KEYID:
 958                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 959                                 return;
 960                         encrypt_enc_keyid(subpointer, SB_LEN());
 961                         break;
 962                 case ENCRYPT_DEC_KEYID:
 963                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 964                                 return;
 965                         encrypt_dec_keyid(subpointer, SB_LEN());
 966                         break;
 967                 default:
 968                         break;
 969                 }
 970                 break;
 971 #endif  /* ENCRYPTION */
 972     default:
 973         break;
 974     }
 975 }
 976
 977 static unsigned char str_lm[] = { IAC, SB, TELOPT_LINEMODE, 0, 0, IAC, SE };
 978
 979 void
 980 lm_will(unsigned char *cmd, int len)
 981 {
 982     if (len < 1) {
 983 /*@*/   printf("lm_will: no command!!!\n");     /* Should not happen... */
 984         return;
 985     }
 986     switch(cmd[0]) {
 987     case LM_FORWARDMASK:        /* We shouldn't ever get this... */
 988     default:
 989         str_lm[3] = DONT;
 990         str_lm[4] = cmd[0];
 991         if (NETROOM() > (int)sizeof(str_lm)) {
 992             ring_supply_data(&netoring, str_lm, sizeof(str_lm));
 993             printsub('>', &str_lm[2], sizeof(str_lm)-2);
 994         }
 995 /*@*/   else printf("lm_will: not enough room in buffer\n");
 996         break;
 997     }
 998 }
 999
1000 void
1001 lm_wont(unsigned char *cmd, int len)
1002 {
1003     if (len < 1) {
1004 /*@*/   printf("lm_wont: no command!!!\n");     /* Should not happen... */
1005         return;
1006     }
1007     switch(cmd[0]) {
1008     case LM_FORWARDMASK:        /* We shouldn't ever get this... */
1009     default:
1010         /* We are always DONT, so don't respond */
1011         return;
1012     }
1013 }
1014
1015 void
1016 lm_do(unsigned char *cmd, int len)
1017 {
1018     if (len < 1) {
1019 /*@*/   printf("lm_do: no command!!!\n");       /* Should not happen... */
1020         return;
1021     }
1022     switch(cmd[0]) {
1023     case LM_FORWARDMASK:
1024     default:
1025         str_lm[3] = WONT;
1026         str_lm[4] = cmd[0];
1027         if (NETROOM() > (int)sizeof(str_lm)) {
1028             ring_supply_data(&netoring, str_lm, sizeof(str_lm));
1029             printsub('>', &str_lm[2], sizeof(str_lm)-2);
1030         }
1031 /*@*/   else printf("lm_do: not enough room in buffer\n");
1032         break;
1033     }
1034 }
1035
1036 void
1037 lm_dont(unsigned char *cmd, int len)
1038 {
1039     if (len < 1) {
1040 /*@*/   printf("lm_dont: no command!!!\n");     /* Should not happen... */
1041         return;
1042     }
1043     switch(cmd[0]) {
1044     case LM_FORWARDMASK:
1045     default:
1046         /* we are always WONT, so don't respond */
1047         break;
1048     }
1049 }
1050
1051 static unsigned char str_lm_mode[] = {
1052         IAC, SB, TELOPT_LINEMODE, LM_MODE, 0, IAC, SE
1053 };
1054
1055 void
1056 lm_mode(unsigned char *cmd, int len, int init)
1057 {
1058         if (len != 1)
1059                 return;
1060         if ((linemode&MODE_MASK&~MODE_ACK) == *cmd)
1061                 return;
1062         if (*cmd&MODE_ACK)
1063                 return;
1064         linemode = *cmd&(MODE_MASK&~MODE_ACK);
1065         str_lm_mode[4] = linemode;
1066         if (!init)
1067             str_lm_mode[4] |= MODE_ACK;
1068         if (NETROOM() > (int)sizeof(str_lm_mode)) {
1069             ring_supply_data(&netoring, str_lm_mode, sizeof(str_lm_mode));
1070             printsub('>', &str_lm_mode[2], sizeof(str_lm_mode)-2);
1071         }
1072 /*@*/   else printf("lm_mode: not enough room in buffer\n");
1073         setconnmode(0); /* set changed mode */
1074 }
1075
1076 \f
1077
1078 /*
1079  * slc()
1080  * Handle special character suboption of LINEMODE.
1081  */
1082
1083 struct spc {
1084         cc_t val;
1085         cc_t *valp;
1086         char flags;     /* Current flags & level */
1087         char mylevel;   /* Maximum level & flags */
1088 } spc_data[NSLC+1];
1089
1090 #define SLC_IMPORT      0
1091 #define SLC_EXPORT      1
1092 #define SLC_RVALUE      2
1093 static int slc_mode = SLC_EXPORT;
1094
1095 void
1096 slc_init(void)
1097 {
1098         struct spc *spcp;
1099
1100         localchars = 1;
1101         for (spcp = spc_data; spcp < &spc_data[NSLC+1]; spcp++) {
1102                 spcp->val = 0;
1103                 spcp->valp = 0;
1104                 spcp->flags = spcp->mylevel = SLC_NOSUPPORT;
1105         }
1106
1107 #define initfunc(func, flags) { \
1108                                         spcp = &spc_data[func]; \
1109                                         if ((spcp->valp = tcval(func))) { \
1110                                             spcp->val = *spcp->valp; \
1111                                             spcp->mylevel = SLC_VARIABLE|flags; \
1112                                         } else { \
1113                                             spcp->val = 0; \
1114                                             spcp->mylevel = SLC_DEFAULT; \
1115                                         } \
1116                                     }
1117
1118         initfunc(SLC_SYNCH, 0);
1119         /* No BRK */
1120         initfunc(SLC_AO, 0);
1121         initfunc(SLC_AYT, 0);
1122         /* No EOR */
1123         initfunc(SLC_ABORT, SLC_FLUSHIN|SLC_FLUSHOUT);
1124         initfunc(SLC_EOF, 0);
1125 #ifndef SYSV_TERMIO
1126         initfunc(SLC_SUSP, SLC_FLUSHIN);
1127 #endif
1128         initfunc(SLC_EC, 0);
1129         initfunc(SLC_EL, 0);
1130 #ifndef SYSV_TERMIO
1131         initfunc(SLC_EW, 0);
1132         initfunc(SLC_RP, 0);
1133         initfunc(SLC_LNEXT, 0);
1134 #endif
1135         initfunc(SLC_XON, 0);
1136         initfunc(SLC_XOFF, 0);
1137 #ifdef  SYSV_TERMIO
1138         spc_data[SLC_XON].mylevel = SLC_CANTCHANGE;
1139         spc_data[SLC_XOFF].mylevel = SLC_CANTCHANGE;
1140 #endif
1141         initfunc(SLC_FORW1, 0);
1142 #ifdef  USE_TERMIO
1143         initfunc(SLC_FORW2, 0);
1144         /* No FORW2 */
1145 #endif
1146
1147         initfunc(SLC_IP, SLC_FLUSHIN|SLC_FLUSHOUT);
1148 #undef  initfunc
1149
1150         if (slc_mode == SLC_EXPORT)
1151                 slc_export();
1152         else
1153                 slc_import(1);
1154
1155 }
1156
1157 void
1158 slcstate(void)
1159 {
1160     printf("Special characters are %s values\n",
1161                 slc_mode == SLC_IMPORT ? "remote default" :
1162                 slc_mode == SLC_EXPORT ? "local" :
1163                                          "remote");
1164 }
1165
1166 void
1167 slc_mode_export(void)
1168 {
1169     slc_mode = SLC_EXPORT;
1170     if (my_state_is_will(TELOPT_LINEMODE))
1171         slc_export();
1172 }
1173
1174 void
1175 slc_mode_import(int def)
1176 {
1177     slc_mode = def ? SLC_IMPORT : SLC_RVALUE;
1178     if (my_state_is_will(TELOPT_LINEMODE))
1179         slc_import(def);
1180 }
1181
1182 unsigned char slc_import_val[] = {
1183         IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_VARIABLE, 0, IAC, SE
1184 };
1185 unsigned char slc_import_def[] = {
1186         IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_DEFAULT, 0, IAC, SE
1187 };
1188
1189 void
1190 slc_import(int def)
1191 {
1192     if (NETROOM() > (int)sizeof(slc_import_val)) {
1193         if (def) {
1194             ring_supply_data(&netoring, slc_import_def, sizeof(slc_import_def));
1195             printsub('>', &slc_import_def[2], sizeof(slc_import_def)-2);
1196         } else {
1197             ring_supply_data(&netoring, slc_import_val, sizeof(slc_import_val));
1198             printsub('>', &slc_import_val[2], sizeof(slc_import_val)-2);
1199         }
1200     }
1201 /*@*/ else printf("slc_import: not enough room\n");
1202 }
1203
1204 void
1205 slc_export(void)
1206 {
1207     struct spc *spcp;
1208
1209     TerminalDefaultChars();
1210
1211     slc_start_reply();
1212     for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1213         if (spcp->mylevel != SLC_NOSUPPORT) {
1214             if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1215                 spcp->flags = SLC_NOSUPPORT;
1216             else
1217                 spcp->flags = spcp->mylevel;
1218             if (spcp->valp)
1219                 spcp->val = *spcp->valp;
1220             slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1221         }
1222     }
1223     slc_end_reply();
1224     (void)slc_update();
1225     setconnmode(1);     /* Make sure the character values are set */
1226 }
1227
1228 void
1229 slc(unsigned char *cp, int len)
1230 {
1231         struct spc *spcp;
1232         int func,level;
1233
1234         slc_start_reply();
1235
1236         for (; len >= 3; len -=3, cp +=3) {
1237
1238                 func = cp[SLC_FUNC];
1239
1240                 if (func == 0) {
1241                         /*
1242                          * Client side: always ignore 0 function.
1243                          */
1244                         continue;
1245                 }
1246                 if (func > NSLC) {
1247                         if ((cp[SLC_FLAGS] & SLC_LEVELBITS) != SLC_NOSUPPORT)
1248                                 slc_add_reply(func, SLC_NOSUPPORT, 0);
1249                         continue;
1250                 }
1251
1252                 spcp = &spc_data[func];
1253
1254                 level = cp[SLC_FLAGS]&(SLC_LEVELBITS|SLC_ACK);
1255
1256                 if ((cp[SLC_VALUE] == (unsigned char)spcp->val) &&
1257                     ((level&SLC_LEVELBITS) == (spcp->flags&SLC_LEVELBITS))) {
1258                         continue;
1259                 }
1260
1261                 if (level == (SLC_DEFAULT|SLC_ACK)) {
1262                         /*
1263                          * This is an error condition, the SLC_ACK
1264                          * bit should never be set for the SLC_DEFAULT
1265                          * level.  Our best guess to recover is to
1266                          * ignore the SLC_ACK bit.
1267                          */
1268                         cp[SLC_FLAGS] &= ~SLC_ACK;
1269                 }
1270
1271                 if (level == ((spcp->flags&SLC_LEVELBITS)|SLC_ACK)) {
1272                         spcp->val = (cc_t)cp[SLC_VALUE];
1273                         spcp->flags = cp[SLC_FLAGS];    /* include SLC_ACK */
1274                         continue;
1275                 }
1276
1277                 level &= ~SLC_ACK;
1278
1279                 if (level <= (spcp->mylevel&SLC_LEVELBITS)) {
1280                         spcp->flags = cp[SLC_FLAGS]|SLC_ACK;
1281                         spcp->val = (cc_t)cp[SLC_VALUE];
1282                 }
1283                 if (level == SLC_DEFAULT) {
1284                         if ((spcp->mylevel&SLC_LEVELBITS) != SLC_DEFAULT)
1285                                 spcp->flags = spcp->mylevel;
1286                         else
1287                                 spcp->flags = SLC_NOSUPPORT;
1288                 }
1289                 slc_add_reply(func, spcp->flags, spcp->val);
1290         }
1291         slc_end_reply();
1292         if (slc_update())
1293                 setconnmode(1); /* set the  new character values */
1294 }
1295
1296 void
1297 slc_check(void)
1298 {
1299     struct spc *spcp;
1300
1301     slc_start_reply();
1302     for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1303         if (spcp->valp && spcp->val != *spcp->valp) {
1304             spcp->val = *spcp->valp;
1305             if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1306                 spcp->flags = SLC_NOSUPPORT;
1307             else
1308                 spcp->flags = spcp->mylevel;
1309             slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1310         }
1311     }
1312     slc_end_reply();
1313     setconnmode(1);
1314 }
1315
1316 unsigned char slc_reply[128];
1317 unsigned char const * const slc_reply_eom = &slc_reply[sizeof(slc_reply)];
1318 unsigned char *slc_replyp;
1319
1320 void
1321 slc_start_reply(void)
1322 {
1323         slc_replyp = slc_reply;
1324         *slc_replyp++ = IAC;
1325         *slc_replyp++ = SB;
1326         *slc_replyp++ = TELOPT_LINEMODE;
1327         *slc_replyp++ = LM_SLC;
1328 }
1329
1330 void
1331 slc_add_reply(unsigned char func, unsigned char flags, cc_t value)
1332 {
1333         /* A sequence of up to 6 bytes my be written for this member of the SLC
1334          * suboption list by this function.  The end of negotiation command,
1335          * which is written by slc_end_reply(), will require 2 additional
1336          * bytes.  Do not proceed unless there is sufficient space for these
1337          * items.
1338          */
1339         if (&slc_replyp[6+2] > slc_reply_eom)
1340                 return;
1341         if ((*slc_replyp++ = func) == IAC)
1342                 *slc_replyp++ = IAC;
1343         if ((*slc_replyp++ = flags) == IAC)
1344                 *slc_replyp++ = IAC;
1345         if ((*slc_replyp++ = (unsigned char)value) == IAC)
1346                 *slc_replyp++ = IAC;
1347 }
1348
1349 void
1350 slc_end_reply(void)
1351 {
1352     int len;
1353     /* The end of negotiation command requires 2 bytes. */
1354     if (&slc_replyp[2] > slc_reply_eom)
1355         return;
1356     *slc_replyp++ = IAC;
1357     *slc_replyp++ = SE;
1358     len = slc_replyp - slc_reply;
1359     if (len <= 6)
1360         return;
1361     if (NETROOM() > len) {
1362         ring_supply_data(&netoring, slc_reply, slc_replyp - slc_reply);
1363         printsub('>', &slc_reply[2], slc_replyp - slc_reply - 2);
1364     }
1365 /*@*/else printf("slc_end_reply: not enough room\n");
1366 }
1367
1368 int
1369 slc_update(void)
1370 {
1371         struct spc *spcp;
1372         int need_update = 0;
1373
1374         for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1375                 if (!(spcp->flags&SLC_ACK))
1376                         continue;
1377                 spcp->flags &= ~SLC_ACK;
1378                 if (spcp->valp && (*spcp->valp != spcp->val)) {
1379                         *spcp->valp = spcp->val;
1380                         need_update = 1;
1381                 }
1382         }
1383         return(need_update);
1384 }
1385
1386 #ifdef  OLD_ENVIRON
1387 # ifdef ENV_HACK
1388 /*
1389  * Earlier version of telnet/telnetd from the BSD code had
1390  * the definitions of VALUE and VAR reversed.  To ensure
1391  * maximum interoperability, we assume that the server is
1392  * an older BSD server, until proven otherwise.  The newer
1393  * BSD servers should be able to handle either definition,
1394  * so it is better to use the wrong values if we don't
1395  * know what type of server it is.
1396  */
1397 int env_auto = 1;
1398 int old_env_var = OLD_ENV_VAR;
1399 int old_env_value = OLD_ENV_VALUE;
1400 # else
1401 #  define old_env_var OLD_ENV_VAR
1402 #  define old_env_value OLD_ENV_VALUE
1403 # endif
1404 #endif
1405
1406 void
1407 env_opt(unsigned char *buf, int len)
1408 {
1409         unsigned char *ep = 0, *epc = 0;
1410         int i;
1411
1412         switch(buf[0]&0xff) {
1413         case TELQUAL_SEND:
1414                 env_opt_start();
1415                 if (len == 1) {
1416                         env_opt_add(NULL);
1417                 } else for (i = 1; i < len; i++) {
1418                         switch (buf[i]&0xff) {
1419 #ifdef  OLD_ENVIRON
1420                         case OLD_ENV_VAR:
1421 # ifdef ENV_HACK
1422                                 if (telopt_environ == TELOPT_OLD_ENVIRON
1423                                     && env_auto) {
1424                                         /* Server has the same definitions */
1425                                         old_env_var = OLD_ENV_VAR;
1426                                         old_env_value = OLD_ENV_VALUE;
1427                                 }
1428                                 /* FALL THROUGH */
1429 # endif
1430                         case OLD_ENV_VALUE:
1431                                 /*
1432                                  * Although OLD_ENV_VALUE is not legal, we will
1433                                  * still recognize it, just in case it is an
1434                                  * old server that has VAR & VALUE mixed up...
1435                                  */
1436                                 /* FALL THROUGH */
1437 #else
1438                         case NEW_ENV_VAR:
1439 #endif
1440                         case ENV_USERVAR:
1441                                 if (ep) {
1442                                         *epc = 0;
1443                                         env_opt_add(ep);
1444                                 }
1445                                 ep = epc = &buf[i+1];
1446                                 break;
1447                         case ENV_ESC:
1448                                 i++;
1449                                 /*FALL THROUGH*/
1450                         default:
1451                                 if (epc)
1452                                         *epc++ = buf[i];
1453                                 break;
1454                         }
1455                 }
1456                 if (ep) {
1457                         *epc = 0;
1458                         env_opt_add(ep);
1459                 }
1460                 env_opt_end(1);
1461                 break;
1462
1463         case TELQUAL_IS:
1464         case TELQUAL_INFO:
1465                 /* Ignore for now.  We shouldn't get it anyway. */
1466                 break;
1467
1468         default:
1469                 break;
1470         }
1471 }
1472
1473 #define OPT_REPLY_SIZE  (2 * SUBBUFSIZE)
1474 unsigned char *opt_reply = NULL;
1475 unsigned char *opt_replyp;
1476 unsigned char *opt_replyend;
1477
1478 void
1479 env_opt_start(void)
1480 {
1481         if (opt_reply)
1482                 opt_reply = (unsigned char *)realloc(opt_reply, OPT_REPLY_SIZE);
1483         else
1484                 opt_reply = (unsigned char *)malloc(OPT_REPLY_SIZE);
1485         if (opt_reply == NULL) {
1486 /*@*/           printf("env_opt_start: malloc()/realloc() failed!!!\n");
1487                 opt_reply = opt_replyp = opt_replyend = NULL;
1488                 return;
1489         }
1490         opt_replyp = opt_reply;
1491         opt_replyend = opt_reply + OPT_REPLY_SIZE;
1492         *opt_replyp++ = IAC;
1493         *opt_replyp++ = SB;
1494         *opt_replyp++ = telopt_environ;
1495         *opt_replyp++ = TELQUAL_IS;
1496 }
1497
1498 void
1499 env_opt_start_info(void)
1500 {
1501         env_opt_start();
1502         if (opt_replyp)
1503             opt_replyp[-1] = TELQUAL_INFO;
1504 }
1505
1506 void
1507 env_opt_add(unsigned char *ep)
1508 {
1509         unsigned char *vp, c;
1510
1511         if (opt_reply == NULL)          /*XXX*/
1512                 return;                 /*XXX*/
1513
1514         if (ep == NULL || *ep == '\0') {
1515                 /* Send user defined variables first. */
1516                 env_default(1, 0);
1517                 while ((ep = env_default(0, 0)))
1518                         env_opt_add(ep);
1519
1520                 /* Now add the list of well know variables.  */
1521                 env_default(1, 1);
1522                 while ((ep = env_default(0, 1)))
1523                         env_opt_add(ep);
1524                 return;
1525         }
1526         vp = env_getvalue(ep);
1527         if (opt_replyp + (vp ? 2 * strlen((char *)vp) : 0) +
1528                                 2 * strlen((char *)ep) + 6 > opt_replyend)
1529         {
1530
1531                 int len;
1532                 opt_replyend += OPT_REPLY_SIZE;
1533                 len = opt_replyend - opt_reply;
1534                 opt_reply = (unsigned char *)realloc(opt_reply, len);
1535                 if (opt_reply == NULL) {
1536 /*@*/                   printf("env_opt_add: realloc() failed!!!\n");
1537                         opt_reply = opt_replyp = opt_replyend = NULL;
1538                         return;
1539                 }
1540                 opt_replyp = opt_reply + len - (opt_replyend - opt_replyp);
1541                 opt_replyend = opt_reply + len;
1542         }
1543         if (opt_welldefined(ep))
1544 #ifdef  OLD_ENVIRON
1545                 if (telopt_environ == TELOPT_OLD_ENVIRON)
1546                         *opt_replyp++ = old_env_var;
1547                 else
1548 #endif
1549                         *opt_replyp++ = NEW_ENV_VAR;
1550         else
1551                 *opt_replyp++ = ENV_USERVAR;
1552         for (;;) {
1553                 while ((c = *ep++)) {
1554                         if (opt_replyp + (2 + 2) > opt_replyend)
1555                                 return;
1556                         switch(c&0xff) {
1557                         case IAC:
1558                                 *opt_replyp++ = IAC;
1559                                 break;
1560                         case NEW_ENV_VAR:
1561                         case NEW_ENV_VALUE:
1562                         case ENV_ESC:
1563                         case ENV_USERVAR:
1564                                 *opt_replyp++ = ENV_ESC;
1565                                 break;
1566                         }
1567                         *opt_replyp++ = c;
1568                 }
1569                 if ((ep = vp)) {
1570                         if (opt_replyp + (1 + 2 + 2) > opt_replyend)
1571                                 return;
1572 #ifdef  OLD_ENVIRON
1573                         if (telopt_environ == TELOPT_OLD_ENVIRON)
1574                                 *opt_replyp++ = old_env_value;
1575                         else
1576 #endif
1577                                 *opt_replyp++ = NEW_ENV_VALUE;
1578                         vp = NULL;
1579                 } else
1580                         break;
1581         }
1582 }
1583
1584 int
1585 opt_welldefined(const char *ep)
1586 {
1587         if ((strcmp(ep, "USER") == 0) ||
1588             (strcmp(ep, "DISPLAY") == 0) ||
1589             (strcmp(ep, "PRINTER") == 0) ||
1590             (strcmp(ep, "SYSTEMTYPE") == 0) ||
1591             (strcmp(ep, "JOB") == 0) ||
1592             (strcmp(ep, "ACCT") == 0))
1593                 return(1);
1594         return(0);
1595 }
1596
1597 void
1598 env_opt_end(int emptyok)
1599 {
1600         int len;
1601
1602         if (opt_replyp + 2 > opt_replyend)
1603                 return;
1604         len = opt_replyp + 2 - opt_reply;
1605         if (emptyok || len > 6) {
1606                 *opt_replyp++ = IAC;
1607                 *opt_replyp++ = SE;
1608                 if (NETROOM() > len) {
1609                         ring_supply_data(&netoring, opt_reply, len);
1610                         printsub('>', &opt_reply[2], len - 2);
1611                 }
1612 /*@*/           else printf("slc_end_reply: not enough room\n");
1613         }
1614         if (opt_reply) {
1615                 free(opt_reply);
1616                 opt_reply = opt_replyp = opt_replyend = NULL;
1617         }
1618 }
1619
1620 \f
1621
1622 int
1623 telrcv(void)
1624 {
1625     int c;
1626     int scc;
1627     unsigned char *sbp;
1628     int count;
1629     int returnValue = 0;
1630
1631     scc = 0;
1632     count = 0;
1633     while (TTYROOM() > 2) {
1634         if (scc == 0) {
1635             if (count) {
1636                 ring_consumed(&netiring, count);
1637                 returnValue = 1;
1638                 count = 0;
1639             }
1640             sbp = netiring.consume;
1641             scc = ring_full_consecutive(&netiring);
1642             if (scc == 0) {
1643                 /* No more data coming in */
1644                 break;
1645             }
1646         }
1647
1648         c = *sbp++ & 0xff, scc--; count++;
1649 #ifdef  ENCRYPTION
1650         if (decrypt_input)
1651                 c = (*decrypt_input)(c);
1652 #endif  /* ENCRYPTION */
1653
1654         switch (telrcv_state) {
1655
1656         case TS_CR:
1657             telrcv_state = TS_DATA;
1658             if (c == '\0') {
1659                 break;  /* Ignore \0 after CR */
1660             }
1661             else if ((c == '\n') && my_want_state_is_dont(TELOPT_ECHO) && !crmod) {
1662                 TTYADD(c);
1663                 break;
1664             }
1665             /* Else, fall through */
1666
1667         case TS_DATA:
1668             if (c == IAC) {
1669                 telrcv_state = TS_IAC;
1670                 break;
1671             }
1672                     /*
1673                      * The 'crmod' hack (see following) is needed
1674                      * since we can't * set CRMOD on output only.
1675                      * Machines like MULTICS like to send \r without
1676                      * \n; since we must turn off CRMOD to get proper
1677                      * input, the mapping is done here (sigh).
1678                      */
1679             if ((c == '\r') && my_want_state_is_dont(TELOPT_BINARY)) {
1680                 if (scc > 0) {
1681                     c = *sbp&0xff;
1682 #ifdef  ENCRYPTION
1683                     if (decrypt_input)
1684                         c = (*decrypt_input)(c);
1685 #endif  /* ENCRYPTION */
1686                     if (c == 0) {
1687                         sbp++, scc--; count++;
1688                         /* a "true" CR */
1689                         TTYADD('\r');
1690                     } else if (my_want_state_is_dont(TELOPT_ECHO) &&
1691                                         (c == '\n')) {
1692                         sbp++, scc--; count++;
1693                         TTYADD('\n');
1694                     } else {
1695 #ifdef  ENCRYPTION
1696                         if (decrypt_input)
1697                             (*decrypt_input)(-1);
1698 #endif  /* ENCRYPTION */
1699
1700                         TTYADD('\r');
1701                         if (crmod) {
1702                                 TTYADD('\n');
1703                         }
1704                     }
1705                 } else {
1706                     telrcv_state = TS_CR;
1707                     TTYADD('\r');
1708                     if (crmod) {
1709                             TTYADD('\n');
1710                     }
1711                 }
1712             } else {
1713                 TTYADD(c);
1714             }
1715             continue;
1716
1717         case TS_IAC:
1718 process_iac:
1719             switch (c) {
1720
1721             case WILL:
1722                 telrcv_state = TS_WILL;
1723                 continue;
1724
1725             case WONT:
1726                 telrcv_state = TS_WONT;
1727                 continue;
1728
1729             case DO:
1730                 telrcv_state = TS_DO;
1731                 continue;
1732
1733             case DONT:
1734                 telrcv_state = TS_DONT;
1735                 continue;
1736
1737             case DM:
1738                     /*
1739                      * We may have missed an urgent notification,
1740                      * so make sure we flush whatever is in the
1741                      * buffer currently.
1742                      */
1743                 printoption("RCVD", IAC, DM);
1744                 SYNCHing = 1;
1745                 (void) ttyflush(1);
1746                 SYNCHing = stilloob();
1747                 settimer(gotDM);
1748                 break;
1749
1750             case SB:
1751                 SB_CLEAR();
1752                 telrcv_state = TS_SB;
1753                 continue;
1754
1755             case IAC:
1756                 TTYADD(IAC);
1757                 break;
1758
1759             case NOP:
1760             case GA:
1761             default:
1762                 printoption("RCVD", IAC, c);
1763                 break;
1764             }
1765             telrcv_state = TS_DATA;
1766             continue;
1767
1768         case TS_WILL:
1769             printoption("RCVD", WILL, c);
1770             willoption(c);
1771             telrcv_state = TS_DATA;
1772             continue;
1773
1774         case TS_WONT:
1775             printoption("RCVD", WONT, c);
1776             wontoption(c);
1777             telrcv_state = TS_DATA;
1778             continue;
1779
1780         case TS_DO:
1781             printoption("RCVD", DO, c);
1782             dooption(c);
1783             if (c == TELOPT_NAWS) {
1784                 sendnaws();
1785             } else if (c == TELOPT_LFLOW) {
1786                 localflow = 1;
1787                 setcommandmode();
1788                 setconnmode(0);
1789             }
1790             telrcv_state = TS_DATA;
1791             continue;
1792
1793         case TS_DONT:
1794             printoption("RCVD", DONT, c);
1795             dontoption(c);
1796             flushline = 1;
1797             setconnmode(0);     /* set new tty mode (maybe) */
1798             telrcv_state = TS_DATA;
1799             continue;
1800
1801         case TS_SB:
1802             if (c == IAC) {
1803                 telrcv_state = TS_SE;
1804             } else {
1805                 SB_ACCUM(c);
1806             }
1807             continue;
1808
1809         case TS_SE:
1810             if (c != SE) {
1811                 if (c != IAC) {
1812                     /*
1813                      * This is an error.  We only expect to get
1814                      * "IAC IAC" or "IAC SE".  Several things may
1815                      * have happend.  An IAC was not doubled, the
1816                      * IAC SE was left off, or another option got
1817                      * inserted into the suboption are all possibilities.
1818                      * If we assume that the IAC was not doubled,
1819                      * and really the IAC SE was left off, we could
1820                      * get into an infinate loop here.  So, instead,
1821                      * we terminate the suboption, and process the
1822                      * partial suboption if we can.
1823                      */
1824                     SB_ACCUM(IAC);
1825                     SB_ACCUM(c);
1826                     subpointer -= 2;
1827                     SB_TERM();
1828
1829                     printoption("In SUBOPTION processing, RCVD", IAC, c);
1830                     suboption();        /* handle sub-option */
1831                     telrcv_state = TS_IAC;
1832                     goto process_iac;
1833                 }
1834                 SB_ACCUM(c);
1835                 telrcv_state = TS_SB;
1836             } else {
1837                 SB_ACCUM(IAC);
1838                 SB_ACCUM(SE);
1839                 subpointer -= 2;
1840                 SB_TERM();
1841                 suboption();    /* handle sub-option */
1842                 telrcv_state = TS_DATA;
1843             }
1844         }
1845     }
1846     if (count)
1847         ring_consumed(&netiring, count);
1848     return returnValue||count;
1849 }
1850
1851 static int bol = 1, local = 0;
1852
1853 int
1854 rlogin_susp(void)
1855 {
1856     if (local) {
1857         local = 0;
1858         bol = 1;
1859         command(0, "z\n", 2);
1860         return(1);
1861     }
1862     return(0);
1863 }
1864
1865 static int
1866 telsnd(void)
1867 {
1868     int tcc;
1869     int count;
1870     int returnValue = 0;
1871     unsigned char *tbp;
1872
1873     tcc = 0;
1874     count = 0;
1875     while (NETROOM() > 2) {
1876         int sc;
1877         int c;
1878
1879         if (tcc == 0) {
1880             if (count) {
1881                 ring_consumed(&ttyiring, count);
1882                 returnValue = 1;
1883                 count = 0;
1884             }
1885             tbp = ttyiring.consume;
1886             tcc = ring_full_consecutive(&ttyiring);
1887             if (tcc == 0) {
1888                 break;
1889             }
1890         }
1891         c = *tbp++ & 0xff, sc = strip(c), tcc--; count++;
1892         if (rlogin != _POSIX_VDISABLE) {
1893                 if (bol) {
1894                         bol = 0;
1895                         if (sc == rlogin) {
1896                                 local = 1;
1897                                 continue;
1898                         }
1899                 } else if (local) {
1900                         local = 0;
1901                         if (sc == '.' || c == termEofChar) {
1902                                 bol = 1;
1903                                 command(0, "close\n", 6);
1904                                 continue;
1905                         }
1906                         if (sc == termSuspChar) {
1907                                 bol = 1;
1908                                 command(0, "z\n", 2);
1909                                 continue;
1910                         }
1911                         if (sc == escape) {
1912                                 command(0, tbp, tcc);
1913                                 bol = 1;
1914                                 count += tcc;
1915                                 tcc = 0;
1916                                 flushline = 1;
1917                                 break;
1918                         }
1919                         if (sc != rlogin) {
1920                                 ++tcc;
1921                                 --tbp;
1922                                 --count;
1923                                 c = sc = rlogin;
1924                         }
1925                 }
1926                 if ((sc == '\n') || (sc == '\r'))
1927                         bol = 1;
1928         } else if (escape != _POSIX_VDISABLE && sc == escape) {
1929             /*
1930              * Double escape is a pass through of a single escape character.
1931              */
1932             if (tcc && strip(*tbp) == escape) {
1933                 tbp++;
1934                 tcc--;
1935                 count++;
1936                 bol = 0;
1937             } else {
1938                 command(0, (char *)tbp, tcc);
1939                 bol = 1;
1940                 count += tcc;
1941                 tcc = 0;
1942                 flushline = 1;
1943                 break;
1944             }
1945         } else
1946             bol = 0;
1947 #ifdef  KLUDGELINEMODE
1948         if (kludgelinemode && (globalmode&MODE_EDIT) && (sc == echoc)) {
1949             if (tcc > 0 && strip(*tbp) == echoc) {
1950                 tcc--; tbp++; count++;
1951             } else {
1952                 dontlecho = !dontlecho;
1953                 settimer(echotoggle);
1954                 setconnmode(0);
1955                 flushline = 1;
1956                 break;
1957             }
1958         }
1959 #endif
1960         if (MODE_LOCAL_CHARS(globalmode)) {
1961             if (TerminalSpecialChars(sc) == 0) {
1962                 bol = 1;
1963                 break;
1964             }
1965         }
1966         if (my_want_state_is_wont(TELOPT_BINARY)) {
1967             switch (c) {
1968             case '\n':
1969                     /*
1970                      * If we are in CRMOD mode (\r ==> \n)
1971                      * on our local machine, then probably
1972                      * a newline (unix) is CRLF (TELNET).
1973                      */
1974                 if (MODE_LOCAL_CHARS(globalmode)) {
1975                     NETADD('\r');
1976                 }
1977                 NETADD('\n');
1978                 bol = flushline = 1;
1979                 break;
1980             case '\r':
1981                 if (!crlf) {
1982                     NET2ADD('\r', '\0');
1983                 } else {
1984                     NET2ADD('\r', '\n');
1985                 }
1986                 bol = flushline = 1;
1987                 break;
1988             case IAC:
1989                 NET2ADD(IAC, IAC);
1990                 break;
1991             default:
1992                 NETADD(c);
1993                 break;
1994             }
1995         } else if (c == IAC) {
1996             NET2ADD(IAC, IAC);
1997         } else {
1998             NETADD(c);
1999         }
2000     }
2001     if (count)
2002         ring_consumed(&ttyiring, count);
2003     return returnValue||count;          /* Non-zero if we did anything */
2004 }
2005 \f
2006 /*
2007  * Scheduler()
2008  *
2009  * Try to do something.
2010  *
2011  * If we do something useful, return 1; else return 0.
2012  *
2013  */
2014
2015 static int
2016 Scheduler(int block)
2017 {
2018                 /* One wants to be a bit careful about setting returnValue
2019                  * to one, since a one implies we did some useful work,
2020                  * and therefore probably won't be called to block next
2021                  */
2022     int returnValue;
2023     int netin, netout, netex, ttyin, ttyout;
2024
2025     /* Decide which rings should be processed */
2026
2027     netout = ring_full_count(&netoring) &&
2028             (flushline ||
2029                 (my_want_state_is_wont(TELOPT_LINEMODE)
2030 #ifdef  KLUDGELINEMODE
2031                         && (!kludgelinemode || my_want_state_is_do(TELOPT_SGA))
2032 #endif
2033                 ) ||
2034                         my_want_state_is_will(TELOPT_BINARY));
2035     ttyout = ring_full_count(&ttyoring);
2036
2037     ttyin = ring_empty_count(&ttyiring) && (clienteof == 0);
2038
2039     netin = !ISend && ring_empty_count(&netiring);
2040
2041     netex = !SYNCHing;
2042
2043     /* Call to system code to process rings */
2044
2045     returnValue = process_rings(netin, netout, netex, ttyin, ttyout, !block);
2046
2047     /* Now, look at the input rings, looking for work to do. */
2048
2049     if (ring_full_count(&ttyiring)) {
2050             returnValue |= telsnd();
2051     }
2052
2053     if (ring_full_count(&netiring)) {
2054         returnValue |= telrcv();
2055     }
2056     return returnValue;
2057 }
2058 \f
2059 #ifdef  AUTHENTICATION
2060 #define __unusedhere
2061 #else
2062 #define __unusedhere __unused
2063 #endif
2064 /*
2065  * Select from tty and network...
2066  */
2067 void
2068 telnet(char *user __unusedhere)
2069 {
2070     sys_telnet_init();
2071
2072 #ifdef  AUTHENTICATION
2073 #ifdef  ENCRYPTION
2074     {
2075         static char local_host[256] = { 0 };
2076
2077         if (!local_host[0]) {
2078                 gethostname(local_host, sizeof(local_host));
2079                 local_host[sizeof(local_host)-1] = 0;
2080         }
2081         auth_encrypt_init(local_host, hostname, "TELNET", 0);
2082         auth_encrypt_user(user);
2083     }
2084 #endif
2085 #endif
2086     if (telnetport) {
2087 #ifdef  AUTHENTICATION
2088         if (autologin)
2089                 send_will(TELOPT_AUTHENTICATION, 1);
2090 #endif
2091 #ifdef  ENCRYPTION
2092         send_do(TELOPT_ENCRYPT, 1);
2093         send_will(TELOPT_ENCRYPT, 1);
2094 #endif  /* ENCRYPTION */
2095         send_do(TELOPT_SGA, 1);
2096         send_will(TELOPT_TTYPE, 1);
2097         send_will(TELOPT_NAWS, 1);
2098         send_will(TELOPT_TSPEED, 1);
2099         send_will(TELOPT_LFLOW, 1);
2100         send_will(TELOPT_LINEMODE, 1);
2101         send_will(TELOPT_NEW_ENVIRON, 1);
2102         send_do(TELOPT_STATUS, 1);
2103         if (env_getvalue("DISPLAY"))
2104             send_will(TELOPT_XDISPLOC, 1);
2105         if (eight)
2106             tel_enter_binary(eight);
2107     }
2108
2109     for (;;) {
2110         int schedValue;
2111
2112         while ((schedValue = Scheduler(0)) != 0) {
2113             if (schedValue == -1) {
2114                 setcommandmode();
2115                 return;
2116             }
2117         }
2118
2119         if (Scheduler(1) == -1) {
2120             setcommandmode();
2121             return;
2122         }
2123     }
2124 }
2125 \f
2126 #if     0       /* XXX - this not being in is a bug */
2127 /*
2128  * nextitem()
2129  *
2130  *      Return the address of the next "item" in the TELNET data
2131  * stream.  This will be the address of the next character if
2132  * the current address is a user data character, or it will
2133  * be the address of the character following the TELNET command
2134  * if the current address is a TELNET IAC ("I Am a Command")
2135  * character.
2136  */
2137
2138 static char *
2139 nextitem(char *current)
2140 {
2141     if ((*current&0xff) != IAC) {
2142         return current+1;
2143     }
2144     switch (*(current+1)&0xff) {
2145     case DO:
2146     case DONT:
2147     case WILL:
2148     case WONT:
2149         return current+3;
2150     case SB:            /* loop forever looking for the SE */
2151         {
2152             char *look = current+2;
2153
2154             for (;;) {
2155                 if ((*look++&0xff) == IAC) {
2156                     if ((*look++&0xff) == SE) {
2157                         return look;
2158                     }
2159                 }
2160             }
2161         }
2162     default:
2163         return current+2;
2164     }
2165 }
2166 #endif  /* 0 */
2167
2168 /*
2169  * netclear()
2170  *
2171  *      We are about to do a TELNET SYNCH operation.  Clear
2172  * the path to the network.
2173  *
2174  *      Things are a bit tricky since we may have sent the first
2175  * byte or so of a previous TELNET command into the network.
2176  * So, we have to scan the network buffer from the beginning
2177  * until we are up to where we want to be.
2178  *
2179  *      A side effect of what we do, just to keep things
2180  * simple, is to clear the urgent data pointer.  The principal
2181  * caller should be setting the urgent data pointer AFTER calling
2182  * us in any case.
2183  */
2184
2185 static void
2186 netclear(void)
2187 {
2188         /* Deleted */
2189 }
2190 \f
2191 /*
2192  * These routines add various telnet commands to the data stream.
2193  */
2194
2195 static void
2196 doflush(void)
2197 {
2198     NET2ADD(IAC, DO);
2199     NETADD(TELOPT_TM);
2200     flushline = 1;
2201     flushout = 1;
2202     (void) ttyflush(1);                 /* Flush/drop output */
2203     /* do printoption AFTER flush, otherwise the output gets tossed... */
2204     printoption("SENT", DO, TELOPT_TM);
2205 }
2206
2207 void
2208 xmitAO(void)
2209 {
2210     NET2ADD(IAC, AO);
2211     printoption("SENT", IAC, AO);
2212     if (autoflush) {
2213         doflush();
2214     }
2215 }
2216
2217 void
2218 xmitEL(void)
2219 {
2220     NET2ADD(IAC, EL);
2221     printoption("SENT", IAC, EL);
2222 }
2223
2224 void
2225 xmitEC(void)
2226 {
2227     NET2ADD(IAC, EC);
2228     printoption("SENT", IAC, EC);
2229 }
2230
2231 int
2232 dosynch(char *ch __unused)
2233 {
2234     netclear();                 /* clear the path to the network */
2235     NETADD(IAC);
2236     setneturg();
2237     NETADD(DM);
2238     printoption("SENT", IAC, DM);
2239     return 1;
2240 }
2241
2242 int want_status_response = 0;
2243
2244 int
2245 get_status(char *ch __unused)
2246 {
2247     unsigned char tmp[16];
2248     unsigned char *cp;
2249
2250     if (my_want_state_is_dont(TELOPT_STATUS)) {
2251         printf("Remote side does not support STATUS option\n");
2252         return 0;
2253     }
2254     cp = tmp;
2255
2256     *cp++ = IAC;
2257     *cp++ = SB;
2258     *cp++ = TELOPT_STATUS;
2259     *cp++ = TELQUAL_SEND;
2260     *cp++ = IAC;
2261     *cp++ = SE;
2262     if (NETROOM() >= cp - tmp) {
2263         ring_supply_data(&netoring, tmp, cp-tmp);
2264         printsub('>', tmp+2, cp - tmp - 2);
2265     }
2266     ++want_status_response;
2267     return 1;
2268 }
2269
2270 void
2271 intp(void)
2272 {
2273     NET2ADD(IAC, IP);
2274     printoption("SENT", IAC, IP);
2275     flushline = 1;
2276     if (autoflush) {
2277         doflush();
2278     }
2279     if (autosynch) {
2280         dosynch(NULL);
2281     }
2282 }
2283
2284 void
2285 sendbrk(void)
2286 {
2287     NET2ADD(IAC, BREAK);
2288     printoption("SENT", IAC, BREAK);
2289     flushline = 1;
2290     if (autoflush) {
2291         doflush();
2292     }
2293     if (autosynch) {
2294         dosynch(NULL);
2295     }
2296 }
2297
2298 void
2299 sendabort(void)
2300 {
2301     NET2ADD(IAC, ABORT);
2302     printoption("SENT", IAC, ABORT);
2303     flushline = 1;
2304     if (autoflush) {
2305         doflush();
2306     }
2307     if (autosynch) {
2308         dosynch(NULL);
2309     }
2310 }
2311
2312 void
2313 sendsusp(void)
2314 {
2315     NET2ADD(IAC, SUSP);
2316     printoption("SENT", IAC, SUSP);
2317     flushline = 1;
2318     if (autoflush) {
2319         doflush();
2320     }
2321     if (autosynch) {
2322         dosynch(NULL);
2323     }
2324 }
2325
2326 void
2327 sendeof(void)
2328 {
2329     NET2ADD(IAC, xEOF);
2330     printoption("SENT", IAC, xEOF);
2331 }
2332
2333 void
2334 sendayt(void)
2335 {
2336     NET2ADD(IAC, AYT);
2337     printoption("SENT", IAC, AYT);
2338 }
2339
2340 /*
2341  * Send a window size update to the remote system.
2342  */
2343
2344 void
2345 sendnaws(void)
2346 {
2347     long rows, cols;
2348     unsigned char tmp[16];
2349     unsigned char *cp;
2350
2351     if (my_state_is_wont(TELOPT_NAWS))
2352         return;
2353
2354 #define PUTSHORT(cp, x) { if ((*cp++ = ((x)>>8)&0xff) == IAC) *cp++ = IAC; \
2355                             if ((*cp++ = ((x))&0xff) == IAC) *cp++ = IAC; }
2356
2357     if (TerminalWindowSize(&rows, &cols) == 0) {        /* Failed */
2358         return;
2359     }
2360
2361     cp = tmp;
2362
2363     *cp++ = IAC;
2364     *cp++ = SB;
2365     *cp++ = TELOPT_NAWS;
2366     PUTSHORT(cp, cols);
2367     PUTSHORT(cp, rows);
2368     *cp++ = IAC;
2369     *cp++ = SE;
2370     if (NETROOM() >= cp - tmp) {
2371         ring_supply_data(&netoring, tmp, cp-tmp);
2372         printsub('>', tmp+2, cp - tmp - 2);
2373     }
2374 }
2375
2376 void
2377 tel_enter_binary(int rw)
2378 {
2379     if (rw&1)
2380         send_do(TELOPT_BINARY, 1);
2381     if (rw&2)
2382         send_will(TELOPT_BINARY, 1);
2383 }
2384
2385 void
2386 tel_leave_binary(int rw)
2387 {
2388     if (rw&1)
2389         send_dont(TELOPT_BINARY, 1);
2390     if (rw&2)
2391         send_wont(TELOPT_BINARY, 1);
2392 }