remote_cmds/telnet.tproj/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
  34 #if 0
  35 #ifndef lint
  36 static const char sccsid[] = "@(#)telnet.c      8.4 (Berkeley) 5/30/95";
  37 #endif
  38 #endif
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD: src/contrib/telnet/telnet/telnet.c,v 1.16 2005/03/28 14:45:12 nectar Exp $");
  41
  42 #include <sys/types.h>
  43
  44 /* By the way, we need to include curses.h before telnet.h since,
  45  * among other things, telnet.h #defines 'DO', which is a variable
  46  * declared in curses.h.
  47  */
  48
  49 #include <ctype.h>
  50 #include <curses.h>
  51 #include <signal.h>
  52 #include <stdlib.h>
  53 #include <term.h>
  54 #include <unistd.h>
  55 #include <arpa/telnet.h>
  56
  57 #include "ring.h"
  58
  59 #include "defines.h"
  60 #include "externs.h"
  61 #include "types.h"
  62 #include "general.h"
  63
  64 #ifdef TERMCAP
  65 #include <curses.h>
  66 #include <term.h>
  67 #endif /* TERMCAP */
  68
  69 #ifdef  AUTHENTICATION
  70 #include <libtelnet/auth.h>
  71 #endif
  72 #ifdef  ENCRYPTION
  73 #include <libtelnet/encrypt.h>
  74 #endif
  75 #include <libtelnet/misc.h>
  76 \f
  77 #define strip(x) ((my_want_state_is_wont(TELOPT_BINARY)) ? ((x)&0x7f) : (x))
  78
  79 static unsigned char    subbuffer[SUBBUFSIZE],
  80                         *subpointer, *subend;    /* buffer for sub-options */
  81 #define SB_CLEAR()      subpointer = subbuffer;
  82 #define SB_TERM()       { subend = subpointer; SB_CLEAR(); }
  83 #define SB_ACCUM(c)     if (subpointer < (subbuffer+sizeof subbuffer)) { \
  84                                 *subpointer++ = (c); \
  85                         }
  86
  87 #define SB_GET()        ((*subpointer++)&0xff)
  88 #define SB_PEEK()       ((*subpointer)&0xff)
  89 #define SB_EOF()        (subpointer >= subend)
  90 #define SB_LEN()        (subend - subpointer)
  91
  92 char    options[256];           /* The combined options */
  93 char    do_dont_resp[256];
  94 char    will_wont_resp[256];
  95
  96 int
  97         eight = 0,
  98         autologin = 0,  /* Autologin anyone? */
  99         skiprc = 0,
 100         connected,
 101         showoptions,
 102         ISend,          /* trying to send network data in */
 103         telnet_debug = 0,
 104         crmod,
 105         netdata,        /* Print out network data flow */
 106         crlf,           /* Should '\r' be mapped to <CR><LF> (or <CR><NUL>)? */
 107         telnetport,
 108         SYNCHing,       /* we are in TELNET SYNCH mode */
 109         flushout,       /* flush output */
 110         autoflush = 0,  /* flush output when interrupting? */
 111         autosynch,      /* send interrupt characters with SYNCH? */
 112         localflow,      /* we handle flow control locally */
 113         restartany,     /* if flow control enabled, restart on any character */
 114         localchars,     /* we recognize interrupt/quit */
 115         donelclchars,   /* the user has set "localchars" */
 116         donebinarytoggle,       /* the user has put us in binary */
 117         dontlecho,      /* do we suppress local echoing right now? */
 118         globalmode,
 119         doaddrlookup = 1, /* do a reverse address lookup? */
 120         clienteof = 0;
 121
 122 char *prompt = 0;
 123 #ifdef ENCRYPTION
 124 char *line;             /* hack around breakage in sra.c :-( !! */
 125 #endif
 126
 127 cc_t escape;
 128 cc_t rlogin;
 129 #ifdef  KLUDGELINEMODE
 130 cc_t echoc;
 131 #endif
 132
 133 /*
 134  * Telnet receiver states for fsm
 135  */
 136 #define TS_DATA         0
 137 #define TS_IAC          1
 138 #define TS_WILL         2
 139 #define TS_WONT         3
 140 #define TS_DO           4
 141 #define TS_DONT         5
 142 #define TS_CR           6
 143 #define TS_SB           7               /* sub-option collection */
 144 #define TS_SE           8               /* looking for sub-option end */
 145
 146 static int      telrcv_state;
 147 #ifdef  OLD_ENVIRON
 148 unsigned char telopt_environ = TELOPT_NEW_ENVIRON;
 149 #else
 150 # define telopt_environ TELOPT_NEW_ENVIRON
 151 #endif
 152
 153 jmp_buf toplevel;
 154 jmp_buf peerdied;
 155
 156 int     flushline;
 157 int     linemode;
 158
 159 #ifdef  KLUDGELINEMODE
 160 int     kludgelinemode = 1;
 161 #endif
 162
 163 static int is_unique(char *, char **, char **);
 164
 165 /*
 166  * The following are some clocks used to decide how to interpret
 167  * the relationship between various variables.
 168  */
 169
 170 Clocks clocks;
 171 \f
 172 /*
 173  * Initialize telnet environment.
 174  */
 175
 176 void
 177 init_telnet(void)
 178 {
 179     env_init();
 180
 181     SB_CLEAR();
 182     ClearArray(options);
 183
 184     connected = ISend = localflow = donebinarytoggle = 0;
 185 #ifdef  AUTHENTICATION
 186 #ifdef  ENCRYPTION
 187     auth_encrypt_connect(connected);
 188 #endif
 189 #endif
 190     restartany = -1;
 191
 192     SYNCHing = 0;
 193
 194     /* Don't change NetTrace */
 195
 196     escape = CONTROL(']');
 197     rlogin = _POSIX_VDISABLE;
 198 #ifdef  KLUDGELINEMODE
 199     echoc = CONTROL('E');
 200 #endif
 201
 202     flushline = 1;
 203     telrcv_state = TS_DATA;
 204 }
 205 \f
 206
 207 /*
 208  * These routines are in charge of sending option negotiations
 209  * to the other side.
 210  *
 211  * The basic idea is that we send the negotiation if either side
 212  * is in disagreement as to what the current state should be.
 213  */
 214
 215 void
 216 send_do(int c, int init)
 217 {
 218     if (init) {
 219         if (((do_dont_resp[c] == 0) && my_state_is_do(c)) ||
 220                                 my_want_state_is_do(c))
 221             return;
 222         set_my_want_state_do(c);
 223         do_dont_resp[c]++;
 224     }
 225     if (telnetport < 0)
 226         return;
 227     NET2ADD(IAC, DO);
 228     NETADD(c);
 229     printoption("SENT", DO, c);
 230 }
 231
 232 void
 233 send_dont(int c, int init)
 234 {
 235     if (init) {
 236         if (((do_dont_resp[c] == 0) && my_state_is_dont(c)) ||
 237                                 my_want_state_is_dont(c))
 238             return;
 239         set_my_want_state_dont(c);
 240         do_dont_resp[c]++;
 241     }
 242     if (telnetport < 0)
 243         return;
 244     NET2ADD(IAC, DONT);
 245     NETADD(c);
 246     printoption("SENT", DONT, c);
 247 }
 248
 249 void
 250 send_will(int c, int init)
 251 {
 252     if (init) {
 253         if (((will_wont_resp[c] == 0) && my_state_is_will(c)) ||
 254                                 my_want_state_is_will(c))
 255             return;
 256         set_my_want_state_will(c);
 257         will_wont_resp[c]++;
 258     }
 259     if (telnetport < 0)
 260         return;
 261     NET2ADD(IAC, WILL);
 262     NETADD(c);
 263     printoption("SENT", WILL, c);
 264 }
 265
 266 void
 267 send_wont(int c, int init)
 268 {
 269     if (init) {
 270         if (((will_wont_resp[c] == 0) && my_state_is_wont(c)) ||
 271                                 my_want_state_is_wont(c))
 272             return;
 273         set_my_want_state_wont(c);
 274         will_wont_resp[c]++;
 275     }
 276     if (telnetport < 0)
 277         return;
 278     NET2ADD(IAC, WONT);
 279     NETADD(c);
 280     printoption("SENT", WONT, c);
 281 }
 282
 283 void
 284 willoption(int option)
 285 {
 286         int new_state_ok = 0;
 287
 288         if (do_dont_resp[option]) {
 289             --do_dont_resp[option];
 290             if (do_dont_resp[option] && my_state_is_do(option))
 291                 --do_dont_resp[option];
 292         }
 293
 294         if ((do_dont_resp[option] == 0) && my_want_state_is_dont(option)) {
 295
 296             switch (option) {
 297
 298             case TELOPT_ECHO:
 299             case TELOPT_BINARY:
 300             case TELOPT_SGA:
 301                 settimer(modenegotiated);
 302                 /* FALLTHROUGH */
 303             case TELOPT_STATUS:
 304 #ifdef  AUTHENTICATION
 305             case TELOPT_AUTHENTICATION:
 306 #endif
 307 #ifdef  ENCRYPTION
 308             case TELOPT_ENCRYPT:
 309 #endif /* ENCRYPTION */
 310                 new_state_ok = 1;
 311                 break;
 312
 313             case TELOPT_TM:
 314                 if (flushout)
 315                     flushout = 0;
 316                 /*
 317                  * Special case for TM.  If we get back a WILL,
 318                  * pretend we got back a WONT.
 319                  */
 320                 set_my_want_state_dont(option);
 321                 set_my_state_dont(option);
 322                 return;                 /* Never reply to TM will's/wont's */
 323
 324             case TELOPT_LINEMODE:
 325             default:
 326                 break;
 327             }
 328
 329             if (new_state_ok) {
 330                 set_my_want_state_do(option);
 331                 send_do(option, 0);
 332                 setconnmode(0);         /* possibly set new tty mode */
 333             } else {
 334                 do_dont_resp[option]++;
 335                 send_dont(option, 0);
 336             }
 337         }
 338         set_my_state_do(option);
 339 #ifdef  ENCRYPTION
 340         if (option == TELOPT_ENCRYPT)
 341                 encrypt_send_support();
 342 #endif  /* ENCRYPTION */
 343 }
 344
 345 void
 346 wontoption(int option)
 347 {
 348         if (do_dont_resp[option]) {
 349             --do_dont_resp[option];
 350             if (do_dont_resp[option] && my_state_is_dont(option))
 351                 --do_dont_resp[option];
 352         }
 353
 354         if ((do_dont_resp[option] == 0) && my_want_state_is_do(option)) {
 355
 356             switch (option) {
 357
 358 #ifdef  KLUDGELINEMODE
 359             case TELOPT_SGA:
 360                 if (!kludgelinemode)
 361                     break;
 362                 /* FALLTHROUGH */
 363 #endif
 364             case TELOPT_ECHO:
 365                 settimer(modenegotiated);
 366                 break;
 367
 368             case TELOPT_TM:
 369                 if (flushout)
 370                     flushout = 0;
 371                 set_my_want_state_dont(option);
 372                 set_my_state_dont(option);
 373                 return;         /* Never reply to TM will's/wont's */
 374
 375             default:
 376                 break;
 377             }
 378             set_my_want_state_dont(option);
 379             if (my_state_is_do(option))
 380                 send_dont(option, 0);
 381             setconnmode(0);                     /* Set new tty mode */
 382         } else if (option == TELOPT_TM) {
 383             /*
 384              * Special case for TM.
 385              */
 386             if (flushout)
 387                 flushout = 0;
 388             set_my_want_state_dont(option);
 389         }
 390         set_my_state_dont(option);
 391 }
 392
 393 static void
 394 dooption(int option)
 395 {
 396         int new_state_ok = 0;
 397
 398         if (will_wont_resp[option]) {
 399             --will_wont_resp[option];
 400             if (will_wont_resp[option] && my_state_is_will(option))
 401                 --will_wont_resp[option];
 402         }
 403
 404         if (will_wont_resp[option] == 0) {
 405           if (my_want_state_is_wont(option)) {
 406
 407             switch (option) {
 408
 409             case TELOPT_TM:
 410                 /*
 411                  * Special case for TM.  We send a WILL, but pretend
 412                  * we sent WONT.
 413                  */
 414                 send_will(option, 0);
 415                 set_my_want_state_wont(TELOPT_TM);
 416                 set_my_state_wont(TELOPT_TM);
 417                 return;
 418
 419             case TELOPT_BINARY:         /* binary mode */
 420             case TELOPT_NAWS:           /* window size */
 421             case TELOPT_TSPEED:         /* terminal speed */
 422             case TELOPT_LFLOW:          /* local flow control */
 423             case TELOPT_TTYPE:          /* terminal type option */
 424             case TELOPT_SGA:            /* no big deal */
 425 #ifdef  ENCRYPTION
 426             case TELOPT_ENCRYPT:        /* encryption variable option */
 427 #endif  /* ENCRYPTION */
 428                 new_state_ok = 1;
 429                 break;
 430
 431             case TELOPT_NEW_ENVIRON:    /* New environment variable option */
 432 #ifdef  OLD_ENVIRON
 433                 if (my_state_is_will(TELOPT_OLD_ENVIRON))
 434                         send_wont(TELOPT_OLD_ENVIRON, 1); /* turn off the old */
 435                 goto env_common;
 436             case TELOPT_OLD_ENVIRON:    /* Old environment variable option */
 437                 if (my_state_is_will(TELOPT_NEW_ENVIRON))
 438                         break;          /* Don't enable if new one is in use! */
 439             env_common:
 440                 telopt_environ = option;
 441 #endif
 442                 new_state_ok = 1;
 443                 break;
 444
 445 #ifdef  AUTHENTICATION
 446             case TELOPT_AUTHENTICATION:
 447                 if (autologin)
 448                         new_state_ok = 1;
 449                 break;
 450 #endif
 451
 452             case TELOPT_XDISPLOC:       /* X Display location */
 453                 if (env_getvalue((const unsigned char *)"DISPLAY"))
 454                     new_state_ok = 1;
 455                 break;
 456
 457             case TELOPT_LINEMODE:
 458 #ifdef  KLUDGELINEMODE
 459                 kludgelinemode = 0;
 460                 send_do(TELOPT_SGA, 1);
 461 #endif
 462                 set_my_want_state_will(TELOPT_LINEMODE);
 463                 send_will(option, 0);
 464                 set_my_state_will(TELOPT_LINEMODE);
 465                 slc_init();
 466                 return;
 467
 468             case TELOPT_ECHO:           /* We're never going to echo... */
 469             default:
 470                 break;
 471             }
 472
 473             if (new_state_ok) {
 474                 set_my_want_state_will(option);
 475                 send_will(option, 0);
 476                 setconnmode(0);                 /* Set new tty mode */
 477             } else {
 478                 will_wont_resp[option]++;
 479                 send_wont(option, 0);
 480             }
 481           } else {
 482             /*
 483              * Handle options that need more things done after the
 484              * other side has acknowledged the option.
 485              */
 486             switch (option) {
 487             case TELOPT_LINEMODE:
 488 #ifdef  KLUDGELINEMODE
 489                 kludgelinemode = 0;
 490                 send_do(TELOPT_SGA, 1);
 491 #endif
 492                 set_my_state_will(option);
 493                 slc_init();
 494                 send_do(TELOPT_SGA, 0);
 495                 return;
 496             }
 497           }
 498         }
 499         set_my_state_will(option);
 500 }
 501
 502 static void
 503 dontoption(int option)
 504 {
 505
 506         if (will_wont_resp[option]) {
 507             --will_wont_resp[option];
 508             if (will_wont_resp[option] && my_state_is_wont(option))
 509                 --will_wont_resp[option];
 510         }
 511
 512         if ((will_wont_resp[option] == 0) && my_want_state_is_will(option)) {
 513             switch (option) {
 514             case TELOPT_LINEMODE:
 515                 linemode = 0;   /* put us back to the default state */
 516                 break;
 517 #ifdef  OLD_ENVIRON
 518             case TELOPT_NEW_ENVIRON:
 519                 /*
 520                  * The new environ option wasn't recognized, try
 521                  * the old one.
 522                  */
 523                 send_will(TELOPT_OLD_ENVIRON, 1);
 524                 telopt_environ = TELOPT_OLD_ENVIRON;
 525                 break;
 526 #endif
 527             }
 528             /* we always accept a DONT */
 529             set_my_want_state_wont(option);
 530             if (my_state_is_will(option))
 531                 send_wont(option, 0);
 532             setconnmode(0);                     /* Set new tty mode */
 533         }
 534         set_my_state_wont(option);
 535 }
 536
 537 /*
 538  * Given a buffer returned by tgetent(), this routine will turn
 539  * the pipe separated list of names in the buffer into an array
 540  * of pointers to null terminated names.  We toss out any bad,
 541  * duplicate, or verbose names (names with spaces).
 542  */
 543
 544 static const char *name_unknown = "UNKNOWN";
 545 static const char *unknown[] = { NULL, NULL };
 546
 547 static const char **
 548 mklist(char *buf, char *name)
 549 {
 550         int n;
 551         char c, *cp, **argvp, *cp2, **argv, **avt;
 552
 553         if (name) {
 554                 if (strlen(name) > 40) {
 555                         name = 0;
 556                         unknown[0] = name_unknown;
 557                 } else {
 558                         unknown[0] = name;
 559                         upcase(name);
 560                 }
 561         } else
 562                 unknown[0] = name_unknown;
 563         /*
 564          * Count up the number of names.
 565          */
 566         for (n = 1, cp = buf; *cp && *cp != ':'; cp++) {
 567                 if (*cp == '|')
 568                         n++;
 569         }
 570         /*
 571          * Allocate an array to put the name pointers into
 572          */
 573         argv = (char **)malloc((n+3)*sizeof(char *));
 574         if (argv == 0)
 575                 return(unknown);
 576
 577         /*
 578          * Fill up the array of pointers to names.
 579          */
 580         *argv = 0;
 581         argvp = argv+1;
 582         n = 0;
 583         for (cp = cp2 = buf; (c = *cp);  cp++) {
 584                 if (c == '|' || c == ':') {
 585                         *cp++ = '\0';
 586                         /*
 587                          * Skip entries that have spaces or are over 40
 588                          * characters long.  If this is our environment
 589                          * name, then put it up front.  Otherwise, as
 590                          * long as this is not a duplicate name (case
 591                          * insensitive) add it to the list.
 592                          */
 593                         if (n || (cp - cp2 > 41))
 594                                 ;
 595                         else if (name && (strncasecmp(name, cp2, cp-cp2) == 0))
 596                                 *argv = cp2;
 597                         else if (is_unique(cp2, argv+1, argvp))
 598                                 *argvp++ = cp2;
 599                         if (c == ':')
 600                                 break;
 601                         /*
 602                          * Skip multiple delimiters. Reset cp2 to
 603                          * the beginning of the next name. Reset n,
 604                          * the flag for names with spaces.
 605                          */
 606                         while ((c = *cp) == '|')
 607                                 cp++;
 608                         cp2 = cp;
 609                         n = 0;
 610                 }
 611                 /*
 612                  * Skip entries with spaces or non-ascii values.
 613                  * Convert lower case letters to upper case.
 614                  */
 615                 if ((c == ' ') || !isascii(c))
 616                         n = 1;
 617                 else if (islower(c))
 618                         *cp = toupper(c);
 619         }
 620
 621         /*
 622          * Check for an old V6 2 character name.  If the second
 623          * name points to the beginning of the buffer, and is
 624          * only 2 characters long, move it to the end of the array.
 625          */
 626         if ((argv[1] == buf) && (strlen(argv[1]) == 2)) {
 627                 --argvp;
 628                 for (avt = &argv[1]; avt < argvp; avt++)
 629                         *avt = *(avt+1);
 630                 *argvp++ = buf;
 631         }
 632
 633         /*
 634          * Duplicate last name, for TTYPE option, and null
 635          * terminate the array.  If we didn't find a match on
 636          * our terminal name, put that name at the beginning.
 637          */
 638         cp = *(argvp-1);
 639         *argvp++ = cp;
 640         *argvp = 0;
 641
 642         if (*argv == 0) {
 643                 if (name)
 644                         *argv = name;
 645                 else {
 646                         --argvp;
 647                         for (avt = argv; avt < argvp; avt++)
 648                                 *avt = *(avt+1);
 649                 }
 650         }
 651         if (*argv)
 652                 return((const char **)argv);
 653         else
 654                 return(unknown);
 655 }
 656
 657 static int
 658 is_unique(char *name, char **as, char **ae)
 659 {
 660         char **ap;
 661         int n;
 662
 663         n = strlen(name) + 1;
 664         for (ap = as; ap < ae; ap++)
 665                 if (strncasecmp(*ap, name, n) == 0)
 666                         return(0);
 667         return (1);
 668 }
 669
 670 #ifdef  TERMCAP
 671 char termbuf[1024];
 672
 673 /*ARGSUSED*/
 674 #ifdef __APPLE__
 675 __private_extern__ int
 676 #else
 677 static int
 678 #endif
 679 setupterm(char *tname, int fd, int *errp)
 680 {
 681         if (tgetent(termbuf, tname) == 1) {
 682                 termbuf[1023] = '\0';
 683                 if (errp)
 684                         *errp = 1;
 685                 return(0);
 686         }
 687         if (errp)
 688                 *errp = 0;
 689         return(-1);
 690 }
 691 #else
 692 #define termbuf ttytype
 693 extern char ttytype[];
 694 #endif
 695
 696 int resettermname = 1;
 697
 698 static const char *
 699 gettermname(void)
 700 {
 701         char *tname;
 702         static const char **tnamep = 0;
 703         static const char **next;
 704         int err;
 705
 706         if (resettermname) {
 707                 resettermname = 0;
 708                 if (tnamep && tnamep != unknown)
 709                         free(tnamep);
 710                 if ((tname = (char *)env_getvalue((const unsigned char *)"TERM")) &&
 711                                 (setupterm(tname, 1, &err) == 0)) {
 712                         tnamep = mklist(termbuf, tname);
 713                 } else {
 714                         if (tname && (strlen(tname) <= 40)) {
 715                                 unknown[0] = tname;
 716                                 upcase(tname);
 717                         } else
 718                                 unknown[0] = name_unknown;
 719                         tnamep = unknown;
 720                 }
 721                 next = tnamep;
 722         }
 723         if (*next == 0)
 724                 next = tnamep;
 725         return(*next++);
 726 }
 727 /*
 728  * suboption()
 729  *
 730  *      Look at the sub-option buffer, and try to be helpful to the other
 731  * side.
 732  *
 733  *      Currently we recognize:
 734  *
 735  *              Terminal type, send request.
 736  *              Terminal speed (send request).
 737  *              Local flow control (is request).
 738  *              Linemode
 739  */
 740
 741 static void
 742 suboption(void)
 743 {
 744     unsigned char subchar;
 745
 746     printsub('<', subbuffer, SB_LEN()+2);
 747     switch (subchar = SB_GET()) {
 748     case TELOPT_TTYPE:
 749         if (my_want_state_is_wont(TELOPT_TTYPE))
 750             return;
 751         if (SB_EOF() || SB_GET() != TELQUAL_SEND) {
 752             return;
 753         } else {
 754             const char *name;
 755             unsigned char temp[50];
 756             int len;
 757
 758             name = gettermname();
 759             len = strlen(name) + 4 + 2;
 760             if (len < NETROOM()) {
 761                 sprintf((char *)temp, "%c%c%c%c%s%c%c", IAC, SB, TELOPT_TTYPE,
 762                                 TELQUAL_IS, name, IAC, SE);
 763                 ring_supply_data(&netoring, temp, len);
 764                 printsub('>', &temp[2], len-2);
 765             } else {
 766                 ExitString("No room in buffer for terminal type.\n", 1);
 767                 /*NOTREACHED*/
 768             }
 769         }
 770         break;
 771     case TELOPT_TSPEED:
 772         if (my_want_state_is_wont(TELOPT_TSPEED))
 773             return;
 774         if (SB_EOF())
 775             return;
 776         if (SB_GET() == TELQUAL_SEND) {
 777             long ospeed, ispeed;
 778             unsigned char temp[50];
 779             int len;
 780
 781             TerminalSpeeds(&ispeed, &ospeed);
 782
 783             sprintf((char *)temp, "%c%c%c%c%ld,%ld%c%c", IAC, SB, TELOPT_TSPEED,
 784                     TELQUAL_IS, ospeed, ispeed, IAC, SE);
 785             len = strlen((char *)temp+4) + 4;   /* temp[3] is 0 ... */
 786
 787             if (len < NETROOM()) {
 788                 ring_supply_data(&netoring, temp, len);
 789                 printsub('>', temp+2, len - 2);
 790             }
 791 /*@*/       else printf("lm_will: not enough room in buffer\n");
 792         }
 793         break;
 794     case TELOPT_LFLOW:
 795         if (my_want_state_is_wont(TELOPT_LFLOW))
 796             return;
 797         if (SB_EOF())
 798             return;
 799         switch(SB_GET()) {
 800         case LFLOW_RESTART_ANY:
 801             restartany = 1;
 802             break;
 803         case LFLOW_RESTART_XON:
 804             restartany = 0;
 805             break;
 806         case LFLOW_ON:
 807             localflow = 1;
 808             break;
 809         case LFLOW_OFF:
 810             localflow = 0;
 811             break;
 812         default:
 813             return;
 814         }
 815         setcommandmode();
 816         setconnmode(0);
 817         break;
 818
 819     case TELOPT_LINEMODE:
 820         if (my_want_state_is_wont(TELOPT_LINEMODE))
 821             return;
 822         if (SB_EOF())
 823             return;
 824         switch (SB_GET()) {
 825         case WILL:
 826             lm_will(subpointer, SB_LEN());
 827             break;
 828         case WONT:
 829             lm_wont(subpointer, SB_LEN());
 830             break;
 831         case DO:
 832             lm_do(subpointer, SB_LEN());
 833             break;
 834         case DONT:
 835             lm_dont(subpointer, SB_LEN());
 836             break;
 837         case LM_SLC:
 838             slc(subpointer, SB_LEN());
 839             break;
 840         case LM_MODE:
 841             lm_mode(subpointer, SB_LEN(), 0);
 842             break;
 843         default:
 844             break;
 845         }
 846         break;
 847
 848 #ifdef  OLD_ENVIRON
 849     case TELOPT_OLD_ENVIRON:
 850 #endif
 851     case TELOPT_NEW_ENVIRON:
 852         if (SB_EOF())
 853             return;
 854         switch(SB_PEEK()) {
 855         case TELQUAL_IS:
 856         case TELQUAL_INFO:
 857             if (my_want_state_is_dont(subchar))
 858                 return;
 859             break;
 860         case TELQUAL_SEND:
 861             if (my_want_state_is_wont(subchar)) {
 862                 return;
 863             }
 864             break;
 865         default:
 866             return;
 867         }
 868         env_opt(subpointer, SB_LEN());
 869         break;
 870
 871     case TELOPT_XDISPLOC:
 872         if (my_want_state_is_wont(TELOPT_XDISPLOC))
 873             return;
 874         if (SB_EOF())
 875             return;
 876         if (SB_GET() == TELQUAL_SEND) {
 877             unsigned char temp[50], *dp;
 878             int len;
 879
 880             if ((dp = env_getvalue((const unsigned char *)"DISPLAY")) == NULL ||
 881                 strlen((const char *)dp) > sizeof(temp) - 7) {
 882                 /*
 883                  * Something happened, we no longer have a DISPLAY
 884                  * variable.  Or it is too long.  So, turn off the option.
 885                  */
 886                 send_wont(TELOPT_XDISPLOC, 1);
 887                 break;
 888             }
 889             snprintf((char *)temp, sizeof(temp), "%c%c%c%c%s%c%c", IAC, SB,
 890                     TELOPT_XDISPLOC, TELQUAL_IS, dp, IAC, SE);
 891             len = strlen((char *)temp+4) + 4;   /* temp[3] is 0 ... */
 892
 893             if (len < NETROOM()) {
 894                 ring_supply_data(&netoring, temp, len);
 895                 printsub('>', temp+2, len - 2);
 896             }
 897 /*@*/       else printf("lm_will: not enough room in buffer\n");
 898         }
 899         break;
 900
 901 #ifdef  AUTHENTICATION
 902         case TELOPT_AUTHENTICATION: {
 903                 if (!autologin)
 904                         break;
 905                 if (SB_EOF())
 906                         return;
 907                 switch(SB_GET()) {
 908                 case TELQUAL_IS:
 909                         if (my_want_state_is_dont(TELOPT_AUTHENTICATION))
 910                                 return;
 911                         auth_is(subpointer, SB_LEN());
 912                         break;
 913                 case TELQUAL_SEND:
 914                         if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
 915                                 return;
 916                         auth_send(subpointer, SB_LEN());
 917                         break;
 918                 case TELQUAL_REPLY:
 919                         if (my_want_state_is_wont(TELOPT_AUTHENTICATION))
 920                                 return;
 921                         auth_reply(subpointer, SB_LEN());
 922                         break;
 923                 case TELQUAL_NAME:
 924                         if (my_want_state_is_dont(TELOPT_AUTHENTICATION))
 925                                 return;
 926                         auth_name(subpointer, SB_LEN());
 927                         break;
 928                 }
 929         }
 930         break;
 931 #endif
 932 #ifdef  ENCRYPTION
 933         case TELOPT_ENCRYPT:
 934                 if (SB_EOF())
 935                         return;
 936                 switch(SB_GET()) {
 937                 case ENCRYPT_START:
 938                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 939                                 return;
 940                         encrypt_start(subpointer, SB_LEN());
 941                         break;
 942                 case ENCRYPT_END:
 943                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 944                                 return;
 945                         encrypt_end();
 946                         break;
 947                 case ENCRYPT_SUPPORT:
 948                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 949                                 return;
 950                         encrypt_support(subpointer, SB_LEN());
 951                         break;
 952                 case ENCRYPT_REQSTART:
 953                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 954                                 return;
 955                         encrypt_request_start(subpointer, SB_LEN());
 956                         break;
 957                 case ENCRYPT_REQEND:
 958                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 959                                 return;
 960                         /*
 961                          * We can always send an REQEND so that we cannot
 962                          * get stuck encrypting.  We should only get this
 963                          * if we have been able to get in the correct mode
 964                          * anyhow.
 965                          */
 966                         encrypt_request_end();
 967                         break;
 968                 case ENCRYPT_IS:
 969                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 970                                 return;
 971                         encrypt_is(subpointer, SB_LEN());
 972                         break;
 973                 case ENCRYPT_REPLY:
 974                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 975                                 return;
 976                         encrypt_reply(subpointer, SB_LEN());
 977                         break;
 978                 case ENCRYPT_ENC_KEYID:
 979                         if (my_want_state_is_dont(TELOPT_ENCRYPT))
 980                                 return;
 981                         encrypt_enc_keyid(subpointer, SB_LEN());
 982                         break;
 983                 case ENCRYPT_DEC_KEYID:
 984                         if (my_want_state_is_wont(TELOPT_ENCRYPT))
 985                                 return;
 986                         encrypt_dec_keyid(subpointer, SB_LEN());
 987                         break;
 988                 default:
 989                         break;
 990                 }
 991                 break;
 992 #endif  /* ENCRYPTION */
 993     default:
 994         break;
 995     }
 996 }
 997
 998 static unsigned char str_lm[] = { IAC, SB, TELOPT_LINEMODE, 0, 0, IAC, SE };
 999
1000 void
1001 lm_will(unsigned char *cmd, int len)
1002 {
1003     if (len < 1) {
1004 /*@*/   printf("lm_will: 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         str_lm[3] = DONT;
1011         str_lm[4] = cmd[0];
1012         if (NETROOM() > (int)sizeof(str_lm)) {
1013             ring_supply_data(&netoring, str_lm, sizeof(str_lm));
1014             printsub('>', &str_lm[2], sizeof(str_lm)-2);
1015         }
1016 /*@*/   else printf("lm_will: not enough room in buffer\n");
1017         break;
1018     }
1019 }
1020
1021 void
1022 lm_wont(unsigned char *cmd, int len)
1023 {
1024     if (len < 1) {
1025 /*@*/   printf("lm_wont: no command!!!\n");     /* Should not happen... */
1026         return;
1027     }
1028     switch(cmd[0]) {
1029     case LM_FORWARDMASK:        /* We shouldn't ever get this... */
1030     default:
1031         /* We are always DONT, so don't respond */
1032         return;
1033     }
1034 }
1035
1036 void
1037 lm_do(unsigned char *cmd, int len)
1038 {
1039     if (len < 1) {
1040 /*@*/   printf("lm_do: no command!!!\n");       /* Should not happen... */
1041         return;
1042     }
1043     switch(cmd[0]) {
1044     case LM_FORWARDMASK:
1045     default:
1046         str_lm[3] = WONT;
1047         str_lm[4] = cmd[0];
1048         if (NETROOM() > (int)sizeof(str_lm)) {
1049             ring_supply_data(&netoring, str_lm, sizeof(str_lm));
1050             printsub('>', &str_lm[2], sizeof(str_lm)-2);
1051         }
1052 /*@*/   else printf("lm_do: not enough room in buffer\n");
1053         break;
1054     }
1055 }
1056
1057 void
1058 lm_dont(unsigned char *cmd, int len)
1059 {
1060     if (len < 1) {
1061 /*@*/   printf("lm_dont: no command!!!\n");     /* Should not happen... */
1062         return;
1063     }
1064     switch(cmd[0]) {
1065     case LM_FORWARDMASK:
1066     default:
1067         /* we are always WONT, so don't respond */
1068         break;
1069     }
1070 }
1071
1072 static unsigned char str_lm_mode[] = {
1073         IAC, SB, TELOPT_LINEMODE, LM_MODE, 0, IAC, SE
1074 };
1075
1076 void
1077 lm_mode(unsigned char *cmd, int len, int init)
1078 {
1079         if (len != 1)
1080                 return;
1081         if ((linemode&MODE_MASK&~MODE_ACK) == *cmd)
1082                 return;
1083         if (*cmd&MODE_ACK)
1084                 return;
1085         linemode = *cmd&(MODE_MASK&~MODE_ACK);
1086         str_lm_mode[4] = linemode;
1087         if (!init)
1088             str_lm_mode[4] |= MODE_ACK;
1089         if (NETROOM() > (int)sizeof(str_lm_mode)) {
1090             ring_supply_data(&netoring, str_lm_mode, sizeof(str_lm_mode));
1091             printsub('>', &str_lm_mode[2], sizeof(str_lm_mode)-2);
1092         }
1093 /*@*/   else printf("lm_mode: not enough room in buffer\n");
1094         setconnmode(0); /* set changed mode */
1095 }
1096
1097 \f
1098
1099 /*
1100  * slc()
1101  * Handle special character suboption of LINEMODE.
1102  */
1103
1104 struct spc {
1105         cc_t val;
1106         cc_t *valp;
1107         char flags;     /* Current flags & level */
1108         char mylevel;   /* Maximum level & flags */
1109 } spc_data[NSLC+1];
1110
1111 #define SLC_IMPORT      0
1112 #define SLC_EXPORT      1
1113 #define SLC_RVALUE      2
1114 static int slc_mode = SLC_EXPORT;
1115
1116 void
1117 slc_init(void)
1118 {
1119         struct spc *spcp;
1120
1121         localchars = 1;
1122         for (spcp = spc_data; spcp < &spc_data[NSLC+1]; spcp++) {
1123                 spcp->val = 0;
1124                 spcp->valp = 0;
1125                 spcp->flags = spcp->mylevel = SLC_NOSUPPORT;
1126         }
1127
1128 #define initfunc(func, flags) { \
1129                                         spcp = &spc_data[func]; \
1130                                         if ((spcp->valp = tcval(func))) { \
1131                                             spcp->val = *spcp->valp; \
1132                                             spcp->mylevel = SLC_VARIABLE|flags; \
1133                                         } else { \
1134                                             spcp->val = 0; \
1135                                             spcp->mylevel = SLC_DEFAULT; \
1136                                         } \
1137                                     }
1138
1139         initfunc(SLC_SYNCH, 0);
1140         /* No BRK */
1141         initfunc(SLC_AO, 0);
1142         initfunc(SLC_AYT, 0);
1143         /* No EOR */
1144         initfunc(SLC_ABORT, SLC_FLUSHIN|SLC_FLUSHOUT);
1145         initfunc(SLC_EOF, 0);
1146 #ifndef SYSV_TERMIO
1147         initfunc(SLC_SUSP, SLC_FLUSHIN);
1148 #endif
1149         initfunc(SLC_EC, 0);
1150         initfunc(SLC_EL, 0);
1151 #ifndef SYSV_TERMIO
1152         initfunc(SLC_EW, 0);
1153         initfunc(SLC_RP, 0);
1154         initfunc(SLC_LNEXT, 0);
1155 #endif
1156         initfunc(SLC_XON, 0);
1157         initfunc(SLC_XOFF, 0);
1158 #ifdef  SYSV_TERMIO
1159         spc_data[SLC_XON].mylevel = SLC_CANTCHANGE;
1160         spc_data[SLC_XOFF].mylevel = SLC_CANTCHANGE;
1161 #endif
1162         initfunc(SLC_FORW1, 0);
1163 #ifdef  USE_TERMIO
1164         initfunc(SLC_FORW2, 0);
1165         /* No FORW2 */
1166 #endif
1167
1168         initfunc(SLC_IP, SLC_FLUSHIN|SLC_FLUSHOUT);
1169 #undef  initfunc
1170
1171         if (slc_mode == SLC_EXPORT)
1172                 slc_export();
1173         else
1174                 slc_import(1);
1175
1176 }
1177
1178 void
1179 slcstate(void)
1180 {
1181     printf("Special characters are %s values\n",
1182                 slc_mode == SLC_IMPORT ? "remote default" :
1183                 slc_mode == SLC_EXPORT ? "local" :
1184                                          "remote");
1185 }
1186
1187 void
1188 slc_mode_export(void)
1189 {
1190     slc_mode = SLC_EXPORT;
1191     if (my_state_is_will(TELOPT_LINEMODE))
1192         slc_export();
1193 }
1194
1195 void
1196 slc_mode_import(int def)
1197 {
1198     slc_mode = def ? SLC_IMPORT : SLC_RVALUE;
1199     if (my_state_is_will(TELOPT_LINEMODE))
1200         slc_import(def);
1201 }
1202
1203 unsigned char slc_import_val[] = {
1204         IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_VARIABLE, 0, IAC, SE
1205 };
1206 unsigned char slc_import_def[] = {
1207         IAC, SB, TELOPT_LINEMODE, LM_SLC, 0, SLC_DEFAULT, 0, IAC, SE
1208 };
1209
1210 void
1211 slc_import(int def)
1212 {
1213     if (NETROOM() > (int)sizeof(slc_import_val)) {
1214         if (def) {
1215             ring_supply_data(&netoring, slc_import_def, sizeof(slc_import_def));
1216             printsub('>', &slc_import_def[2], sizeof(slc_import_def)-2);
1217         } else {
1218             ring_supply_data(&netoring, slc_import_val, sizeof(slc_import_val));
1219             printsub('>', &slc_import_val[2], sizeof(slc_import_val)-2);
1220         }
1221     }
1222 /*@*/ else printf("slc_import: not enough room\n");
1223 }
1224
1225 void
1226 slc_export(void)
1227 {
1228     struct spc *spcp;
1229
1230     TerminalDefaultChars();
1231
1232     slc_start_reply();
1233     for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1234         if (spcp->mylevel != SLC_NOSUPPORT) {
1235             if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1236                 spcp->flags = SLC_NOSUPPORT;
1237             else
1238                 spcp->flags = spcp->mylevel;
1239             if (spcp->valp)
1240                 spcp->val = *spcp->valp;
1241             slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1242         }
1243     }
1244     slc_end_reply();
1245     (void)slc_update();
1246     setconnmode(1);     /* Make sure the character values are set */
1247 }
1248
1249 void
1250 slc(unsigned char *cp, int len)
1251 {
1252         struct spc *spcp;
1253         int func,level;
1254
1255         slc_start_reply();
1256
1257         for (; len >= 3; len -=3, cp +=3) {
1258
1259                 func = cp[SLC_FUNC];
1260
1261                 if (func == 0) {
1262                         /*
1263                          * Client side: always ignore 0 function.
1264                          */
1265                         continue;
1266                 }
1267                 if (func > NSLC) {
1268                         if ((cp[SLC_FLAGS] & SLC_LEVELBITS) != SLC_NOSUPPORT)
1269                                 slc_add_reply(func, SLC_NOSUPPORT, 0);
1270                         continue;
1271                 }
1272
1273                 spcp = &spc_data[func];
1274
1275                 level = cp[SLC_FLAGS]&(SLC_LEVELBITS|SLC_ACK);
1276
1277                 if ((cp[SLC_VALUE] == (unsigned char)spcp->val) &&
1278                     ((level&SLC_LEVELBITS) == (spcp->flags&SLC_LEVELBITS))) {
1279                         continue;
1280                 }
1281
1282                 if (level == (SLC_DEFAULT|SLC_ACK)) {
1283                         /*
1284                          * This is an error condition, the SLC_ACK
1285                          * bit should never be set for the SLC_DEFAULT
1286                          * level.  Our best guess to recover is to
1287                          * ignore the SLC_ACK bit.
1288                          */
1289                         cp[SLC_FLAGS] &= ~SLC_ACK;
1290                 }
1291
1292                 if (level == ((spcp->flags&SLC_LEVELBITS)|SLC_ACK)) {
1293                         spcp->val = (cc_t)cp[SLC_VALUE];
1294                         spcp->flags = cp[SLC_FLAGS];    /* include SLC_ACK */
1295                         continue;
1296                 }
1297
1298                 level &= ~SLC_ACK;
1299
1300                 if (level <= (spcp->mylevel&SLC_LEVELBITS)) {
1301                         spcp->flags = cp[SLC_FLAGS]|SLC_ACK;
1302                         spcp->val = (cc_t)cp[SLC_VALUE];
1303                 }
1304                 if (level == SLC_DEFAULT) {
1305                         if ((spcp->mylevel&SLC_LEVELBITS) != SLC_DEFAULT)
1306                                 spcp->flags = spcp->mylevel;
1307                         else
1308                                 spcp->flags = SLC_NOSUPPORT;
1309                 }
1310                 slc_add_reply(func, spcp->flags, spcp->val);
1311         }
1312         slc_end_reply();
1313         if (slc_update())
1314                 setconnmode(1); /* set the  new character values */
1315 }
1316
1317 void
1318 slc_check(void)
1319 {
1320     struct spc *spcp;
1321
1322     slc_start_reply();
1323     for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1324         if (spcp->valp && spcp->val != *spcp->valp) {
1325             spcp->val = *spcp->valp;
1326             if (spcp->val == (cc_t)(_POSIX_VDISABLE))
1327                 spcp->flags = SLC_NOSUPPORT;
1328             else
1329                 spcp->flags = spcp->mylevel;
1330             slc_add_reply(spcp - spc_data, spcp->flags, spcp->val);
1331         }
1332     }
1333     slc_end_reply();
1334     setconnmode(1);
1335 }
1336
1337 unsigned char slc_reply[128];
1338 unsigned char const * const slc_reply_eom = &slc_reply[sizeof(slc_reply)];
1339 unsigned char *slc_replyp;
1340
1341 void
1342 slc_start_reply(void)
1343 {
1344         slc_replyp = slc_reply;
1345         *slc_replyp++ = IAC;
1346         *slc_replyp++ = SB;
1347         *slc_replyp++ = TELOPT_LINEMODE;
1348         *slc_replyp++ = LM_SLC;
1349 }
1350
1351 void
1352 slc_add_reply(unsigned char func, unsigned char flags, cc_t value)
1353 {
1354         /* A sequence of up to 6 bytes my be written for this member of the SLC
1355          * suboption list by this function.  The end of negotiation command,
1356          * which is written by slc_end_reply(), will require 2 additional
1357          * bytes.  Do not proceed unless there is sufficient space for these
1358          * items.
1359          */
1360         if (&slc_replyp[6+2] > slc_reply_eom)
1361                 return;
1362         if ((*slc_replyp++ = func) == IAC)
1363                 *slc_replyp++ = IAC;
1364         if ((*slc_replyp++ = flags) == IAC)
1365                 *slc_replyp++ = IAC;
1366         if ((*slc_replyp++ = (unsigned char)value) == IAC)
1367                 *slc_replyp++ = IAC;
1368 }
1369
1370 void
1371 slc_end_reply(void)
1372 {
1373     int len;
1374
1375     /* The end of negotiation command requires 2 bytes. */
1376     if (&slc_replyp[2] > slc_reply_eom)
1377             return;
1378     *slc_replyp++ = IAC;
1379     *slc_replyp++ = SE;
1380     len = slc_replyp - slc_reply;
1381     if (len <= 6)
1382         return;
1383     if (NETROOM() > len) {
1384         ring_supply_data(&netoring, slc_reply, slc_replyp - slc_reply);
1385         printsub('>', &slc_reply[2], slc_replyp - slc_reply - 2);
1386     }
1387 /*@*/else printf("slc_end_reply: not enough room\n");
1388 }
1389
1390 int
1391 slc_update(void)
1392 {
1393         struct spc *spcp;
1394         int need_update = 0;
1395
1396         for (spcp = &spc_data[1]; spcp < &spc_data[NSLC+1]; spcp++) {
1397                 if (!(spcp->flags&SLC_ACK))
1398                         continue;
1399                 spcp->flags &= ~SLC_ACK;
1400                 if (spcp->valp && (*spcp->valp != spcp->val)) {
1401                         *spcp->valp = spcp->val;
1402                         need_update = 1;
1403                 }
1404         }
1405         return(need_update);
1406 }
1407
1408 #ifdef  OLD_ENVIRON
1409 # ifdef ENV_HACK
1410 /*
1411  * Earlier version of telnet/telnetd from the BSD code had
1412  * the definitions of VALUE and VAR reversed.  To ensure
1413  * maximum interoperability, we assume that the server is
1414  * an older BSD server, until proven otherwise.  The newer
1415  * BSD servers should be able to handle either definition,
1416  * so it is better to use the wrong values if we don't
1417  * know what type of server it is.
1418  */
1419 int env_auto = 1;
1420 int old_env_var = OLD_ENV_VAR;
1421 int old_env_value = OLD_ENV_VALUE;
1422 # else
1423 #  define old_env_var OLD_ENV_VAR
1424 #  define old_env_value OLD_ENV_VALUE
1425 # endif
1426 #endif
1427
1428 void
1429 env_opt(unsigned char *buf, int len)
1430 {
1431         unsigned char *ep = 0, *epc = 0;
1432         int i;
1433
1434         switch(buf[0]&0xff) {
1435         case TELQUAL_SEND:
1436                 env_opt_start();
1437                 if (len == 1) {
1438                         env_opt_add(NULL);
1439                 } else for (i = 1; i < len; i++) {
1440                         switch (buf[i]&0xff) {
1441 #ifdef  OLD_ENVIRON
1442                         case OLD_ENV_VAR:
1443 # ifdef ENV_HACK
1444                                 if (telopt_environ == TELOPT_OLD_ENVIRON
1445                                     && env_auto) {
1446                                         /* Server has the same definitions */
1447                                         old_env_var = OLD_ENV_VAR;
1448                                         old_env_value = OLD_ENV_VALUE;
1449                                 }
1450                                 /* FALLTHROUGH */
1451 # endif
1452                         case OLD_ENV_VALUE:
1453                                 /*
1454                                  * Although OLD_ENV_VALUE is not legal, we will
1455                                  * still recognize it, just in case it is an
1456                                  * old server that has VAR & VALUE mixed up...
1457                                  */
1458                                 /* FALLTHROUGH */
1459 #else
1460                         case NEW_ENV_VAR:
1461 #endif
1462                         case ENV_USERVAR:
1463                                 if (ep) {
1464                                         *epc = 0;
1465                                         env_opt_add(ep);
1466                                 }
1467                                 ep = epc = &buf[i+1];
1468                                 break;
1469                         case ENV_ESC:
1470                                 i++;
1471                                 /*FALLTHROUGH*/
1472                         default:
1473                                 if (epc)
1474                                         *epc++ = buf[i];
1475                                 break;
1476                         }
1477                 }
1478                 if (ep) {
1479                         *epc = 0;
1480                         env_opt_add(ep);
1481                 }
1482                 env_opt_end(1);
1483                 break;
1484
1485         case TELQUAL_IS:
1486         case TELQUAL_INFO:
1487                 /* Ignore for now.  We shouldn't get it anyway. */
1488                 break;
1489
1490         default:
1491                 break;
1492         }
1493 }
1494
1495 #define OPT_REPLY_SIZE  (2 * SUBBUFSIZE)
1496 unsigned char *opt_reply = NULL;
1497 unsigned char *opt_replyp;
1498 unsigned char *opt_replyend;
1499
1500 void
1501 env_opt_start(void)
1502 {
1503         if (opt_reply)
1504                 opt_reply = (unsigned char *)realloc(opt_reply, OPT_REPLY_SIZE);
1505         else
1506                 opt_reply = (unsigned char *)malloc(OPT_REPLY_SIZE);
1507         if (opt_reply == NULL) {
1508 /*@*/           printf("env_opt_start: malloc()/realloc() failed!!!\n");
1509                 opt_reply = opt_replyp = opt_replyend = NULL;
1510                 return;
1511         }
1512         opt_replyp = opt_reply;
1513         opt_replyend = opt_reply + OPT_REPLY_SIZE;
1514         *opt_replyp++ = IAC;
1515         *opt_replyp++ = SB;
1516         *opt_replyp++ = telopt_environ;
1517         *opt_replyp++ = TELQUAL_IS;
1518 }
1519
1520 void
1521 env_opt_start_info(void)
1522 {
1523         env_opt_start();
1524         if (opt_replyp)
1525             opt_replyp[-1] = TELQUAL_INFO;
1526 }
1527
1528 void
1529 env_opt_add(unsigned char *ep)
1530 {
1531         unsigned char *vp, c;
1532
1533         if (opt_reply == NULL)          /*XXX*/
1534                 return;                 /*XXX*/
1535
1536         if (ep == NULL || *ep == '\0') {
1537                 /* Send user defined variables first. */
1538                 env_default(1, 0);
1539                 while ((ep = env_default(0, 0)))
1540                         env_opt_add(ep);
1541
1542                 /* Now add the list of well know variables.  */
1543                 env_default(1, 1);
1544                 while ((ep = env_default(0, 1)))
1545                         env_opt_add(ep);
1546                 return;
1547         }
1548         vp = env_getvalue(ep);
1549         if (opt_replyp + (vp ? 2 * strlen((char *)vp) : 0) +
1550                                 2 * strlen((char *)ep) + 6 > opt_replyend)
1551         {
1552                 int len;
1553 #ifdef __APPLE__
1554                 // rdar://problem/4022837
1555                 opt_replyend += OPT_REPLY_SIZE + 2*strlen((char *)ep) + 2*(vp ? strlen((char *)vp) : 0);
1556 #else
1557                 opt_replyend += OPT_REPLY_SIZE;
1558 #endif
1559                 len = opt_replyend - opt_reply;
1560                 opt_reply = (unsigned char *)realloc(opt_reply, len);
1561                 if (opt_reply == NULL) {
1562 /*@*/                   printf("env_opt_add: realloc() failed!!!\n");
1563                         opt_reply = opt_replyp = opt_replyend = NULL;
1564                         return;
1565                 }
1566                 opt_replyp = opt_reply + len - (opt_replyend - opt_replyp);
1567                 opt_replyend = opt_reply + len;
1568         }
1569         if (opt_welldefined((const char *)ep))
1570 #ifdef  OLD_ENVIRON
1571                 if (telopt_environ == TELOPT_OLD_ENVIRON)
1572                         *opt_replyp++ = old_env_var;
1573                 else
1574 #endif
1575                         *opt_replyp++ = NEW_ENV_VAR;
1576         else
1577                 *opt_replyp++ = ENV_USERVAR;
1578         for (;;) {
1579                 while ((c = *ep++)) {
1580                         if (opt_replyp + (2 + 2) > opt_replyend)
1581                                 return;
1582                         switch(c&0xff) {
1583                         case IAC:
1584                                 *opt_replyp++ = IAC;
1585                                 break;
1586                         case NEW_ENV_VAR:
1587                         case NEW_ENV_VALUE:
1588                         case ENV_ESC:
1589                         case ENV_USERVAR:
1590                                 *opt_replyp++ = ENV_ESC;
1591                                 break;
1592                         }
1593                         *opt_replyp++ = c;
1594                 }
1595                 if ((ep = vp)) {
1596                         if (opt_replyp + (1 + 2 + 2) > opt_replyend)
1597                                 return;
1598 #ifdef  OLD_ENVIRON
1599                         if (telopt_environ == TELOPT_OLD_ENVIRON)
1600                                 *opt_replyp++ = old_env_value;
1601                         else
1602 #endif
1603                                 *opt_replyp++ = NEW_ENV_VALUE;
1604                         vp = NULL;
1605                 } else
1606                         break;
1607         }
1608 }
1609
1610 int
1611 opt_welldefined(const char *ep)
1612 {
1613         if ((strcmp(ep, "USER") == 0) ||
1614             (strcmp(ep, "DISPLAY") == 0) ||
1615             (strcmp(ep, "PRINTER") == 0) ||
1616             (strcmp(ep, "SYSTEMTYPE") == 0) ||
1617             (strcmp(ep, "JOB") == 0) ||
1618             (strcmp(ep, "ACCT") == 0))
1619                 return(1);
1620         return(0);
1621 }
1622
1623 void
1624 env_opt_end(int emptyok)
1625 {
1626         int len;
1627
1628         if (opt_replyp + 2 > opt_replyend)
1629                 return;
1630         len = opt_replyp + 2 - opt_reply;
1631         if (emptyok || len > 6) {
1632                 *opt_replyp++ = IAC;
1633                 *opt_replyp++ = SE;
1634                 if (NETROOM() > len) {
1635                         ring_supply_data(&netoring, opt_reply, len);
1636                         printsub('>', &opt_reply[2], len - 2);
1637                 }
1638 /*@*/           else printf("slc_end_reply: not enough room\n");
1639         }
1640         if (opt_reply) {
1641                 free(opt_reply);
1642                 opt_reply = opt_replyp = opt_replyend = NULL;
1643         }
1644 }
1645
1646 \f
1647
1648 int
1649 telrcv(void)
1650 {
1651     int c;
1652     int scc;
1653     unsigned char *sbp = NULL;
1654     int count;
1655     int returnValue = 0;
1656
1657     scc = 0;
1658     count = 0;
1659     while (TTYROOM() > 2) {
1660         if (scc == 0) {
1661             if (count) {
1662                 ring_consumed(&netiring, count);
1663                 returnValue = 1;
1664                 count = 0;
1665             }
1666             sbp = netiring.consume;
1667             scc = ring_full_consecutive(&netiring);
1668             if (scc == 0) {
1669                 /* No more data coming in */
1670                 break;
1671             }
1672         }
1673
1674         c = *sbp++ & 0xff, scc--; count++;
1675 #ifdef  ENCRYPTION
1676         if (decrypt_input)
1677                 c = (*decrypt_input)(c);
1678 #endif  /* ENCRYPTION */
1679
1680         switch (telrcv_state) {
1681
1682         case TS_CR:
1683             telrcv_state = TS_DATA;
1684             if (c == '\0') {
1685                 break;  /* Ignore \0 after CR */
1686             }
1687             else if ((c == '\n') && my_want_state_is_dont(TELOPT_ECHO) && !crmod) {
1688                 TTYADD(c);
1689                 break;
1690             }
1691             /* FALLTHROUGH */
1692
1693         case TS_DATA:
1694             if (c == IAC && telnetport >= 0) {
1695                 telrcv_state = TS_IAC;
1696                 break;
1697             }
1698                     /*
1699                      * The 'crmod' hack (see following) is needed
1700                      * since we can't * set CRMOD on output only.
1701                      * Machines like MULTICS like to send \r without
1702                      * \n; since we must turn off CRMOD to get proper
1703                      * input, the mapping is done here (sigh).
1704                      */
1705             if ((c == '\r') && my_want_state_is_dont(TELOPT_BINARY)) {
1706                 if (scc > 0) {
1707                     c = *sbp&0xff;
1708 #ifdef  ENCRYPTION
1709                     if (decrypt_input)
1710                         c = (*decrypt_input)(c);
1711 #endif  /* ENCRYPTION */
1712                     if (c == 0) {
1713                         sbp++, scc--; count++;
1714                         /* a "true" CR */
1715                         TTYADD('\r');
1716                     } else if (my_want_state_is_dont(TELOPT_ECHO) &&
1717                                         (c == '\n')) {
1718                         sbp++, scc--; count++;
1719                         TTYADD('\n');
1720                     } else {
1721 #ifdef  ENCRYPTION
1722                         if (decrypt_input)
1723                             (*decrypt_input)(-1);
1724 #endif  /* ENCRYPTION */
1725
1726                         TTYADD('\r');
1727                         if (crmod) {
1728                                 TTYADD('\n');
1729                         }
1730                     }
1731                 } else {
1732                     telrcv_state = TS_CR;
1733                     TTYADD('\r');
1734                     if (crmod) {
1735                             TTYADD('\n');
1736                     }
1737                 }
1738             } else {
1739                 TTYADD(c);
1740             }
1741             continue;
1742
1743         case TS_IAC:
1744 process_iac:
1745             switch (c) {
1746
1747             case WILL:
1748                 telrcv_state = TS_WILL;
1749                 continue;
1750
1751             case WONT:
1752                 telrcv_state = TS_WONT;
1753                 continue;
1754
1755             case DO:
1756                 telrcv_state = TS_DO;
1757                 continue;
1758
1759             case DONT:
1760                 telrcv_state = TS_DONT;
1761                 continue;
1762
1763             case DM:
1764                     /*
1765                      * We may have missed an urgent notification,
1766                      * so make sure we flush whatever is in the
1767                      * buffer currently.
1768                      */
1769                 printoption("RCVD", IAC, DM);
1770                 SYNCHing = 1;
1771                 (void) ttyflush(1);
1772                 SYNCHing = stilloob();
1773                 settimer(gotDM);
1774                 break;
1775
1776             case SB:
1777                 SB_CLEAR();
1778                 telrcv_state = TS_SB;
1779                 continue;
1780
1781             case IAC:
1782                 TTYADD(IAC);
1783                 break;
1784
1785             case NOP:
1786             case GA:
1787             default:
1788                 printoption("RCVD", IAC, c);
1789                 break;
1790             }
1791             telrcv_state = TS_DATA;
1792             continue;
1793
1794         case TS_WILL:
1795             printoption("RCVD", WILL, c);
1796             willoption(c);
1797             telrcv_state = TS_DATA;
1798             continue;
1799
1800         case TS_WONT:
1801             printoption("RCVD", WONT, c);
1802             wontoption(c);
1803             telrcv_state = TS_DATA;
1804             continue;
1805
1806         case TS_DO:
1807             printoption("RCVD", DO, c);
1808             dooption(c);
1809             if (c == TELOPT_NAWS) {
1810                 sendnaws();
1811             } else if (c == TELOPT_LFLOW) {
1812                 localflow = 1;
1813                 setcommandmode();
1814                 setconnmode(0);
1815             }
1816             telrcv_state = TS_DATA;
1817             continue;
1818
1819         case TS_DONT:
1820             printoption("RCVD", DONT, c);
1821             dontoption(c);
1822             flushline = 1;
1823             setconnmode(0);     /* set new tty mode (maybe) */
1824             telrcv_state = TS_DATA;
1825             continue;
1826
1827         case TS_SB:
1828             if (c == IAC) {
1829                 telrcv_state = TS_SE;
1830             } else {
1831                 SB_ACCUM(c);
1832             }
1833             continue;
1834
1835         case TS_SE:
1836             if (c != SE) {
1837                 if (c != IAC) {
1838                     /*
1839                      * This is an error.  We only expect to get
1840                      * "IAC IAC" or "IAC SE".  Several things may
1841                      * have happend.  An IAC was not doubled, the
1842                      * IAC SE was left off, or another option got
1843                      * inserted into the suboption are all possibilities.
1844                      * If we assume that the IAC was not doubled,
1845                      * and really the IAC SE was left off, we could
1846                      * get into an infinate loop here.  So, instead,
1847                      * we terminate the suboption, and process the
1848                      * partial suboption if we can.
1849                      */
1850                     SB_ACCUM(IAC);
1851                     SB_ACCUM(c);
1852                     subpointer -= 2;
1853                     SB_TERM();
1854
1855                     printoption("In SUBOPTION processing, RCVD", IAC, c);
1856                     suboption();        /* handle sub-option */
1857                     telrcv_state = TS_IAC;
1858                     goto process_iac;
1859                 }
1860                 SB_ACCUM(c);
1861                 telrcv_state = TS_SB;
1862             } else {
1863                 SB_ACCUM(IAC);
1864                 SB_ACCUM(SE);
1865                 subpointer -= 2;
1866                 SB_TERM();
1867                 suboption();    /* handle sub-option */
1868                 telrcv_state = TS_DATA;
1869             }
1870         }
1871     }
1872     if (count)
1873         ring_consumed(&netiring, count);
1874     return returnValue||count;
1875 }
1876
1877 static int bol = 1, local = 0;
1878
1879 int
1880 rlogin_susp(void)
1881 {
1882     if (local) {
1883         local = 0;
1884         bol = 1;
1885         command(0, "z\n", 2);
1886         return(1);
1887     }
1888     return(0);
1889 }
1890
1891 static int
1892 telsnd(void)
1893 {
1894     int tcc;
1895     int count;
1896     int returnValue = 0;
1897     unsigned char *tbp = NULL;
1898
1899     tcc = 0;
1900     count = 0;
1901     while (NETROOM() > 2) {
1902         int sc;
1903         int c;
1904
1905         if (tcc == 0) {
1906             if (count) {
1907                 ring_consumed(&ttyiring, count);
1908                 returnValue = 1;
1909                 count = 0;
1910             }
1911             tbp = ttyiring.consume;
1912             tcc = ring_full_consecutive(&ttyiring);
1913             if (tcc == 0) {
1914                 break;
1915             }
1916         }
1917         c = *tbp++ & 0xff, sc = strip(c), tcc--; count++;
1918         if (rlogin != _POSIX_VDISABLE) {
1919                 if (bol) {
1920                         bol = 0;
1921                         if (sc == rlogin) {
1922                                 local = 1;
1923                                 continue;
1924                         }
1925                 } else if (local) {
1926                         local = 0;
1927                         if (sc == '.' || c == termEofChar) {
1928                                 bol = 1;
1929                                 command(0, "close\n", 6);
1930                                 continue;
1931                         }
1932                         if (sc == termSuspChar) {
1933                                 bol = 1;
1934                                 command(0, "z\n", 2);
1935                                 continue;
1936                         }
1937                         if (sc == escape) {
1938                                 command(0, (const char *)tbp, tcc);
1939                                 bol = 1;
1940                                 count += tcc;
1941                                 tcc = 0;
1942                                 flushline = 1;
1943                                 break;
1944                         }
1945                         if (sc != rlogin) {
1946                                 ++tcc;
1947                                 --tbp;
1948                                 --count;
1949                                 c = sc = rlogin;
1950                         }
1951                 }
1952                 if ((sc == '\n') || (sc == '\r'))
1953                         bol = 1;
1954         } else if (escape != _POSIX_VDISABLE && sc == escape) {
1955             /*
1956              * Double escape is a pass through of a single escape character.
1957              */
1958             if (tcc && strip(*tbp) == escape) {
1959                 tbp++;
1960                 tcc--;
1961                 count++;
1962                 bol = 0;
1963             } else {
1964                 command(0, (char *)tbp, tcc);
1965                 bol = 1;
1966                 count += tcc;
1967                 tcc = 0;
1968                 flushline = 1;
1969                 break;
1970             }
1971         } else
1972             bol = 0;
1973 #ifdef  KLUDGELINEMODE
1974         if (kludgelinemode && (globalmode&MODE_EDIT) && (sc == echoc)) {
1975             if (tcc > 0 && strip(*tbp) == echoc) {
1976                 tcc--; tbp++; count++;
1977             } else {
1978                 dontlecho = !dontlecho;
1979                 settimer(echotoggle);
1980                 setconnmode(0);
1981                 flushline = 1;
1982                 break;
1983             }
1984         }
1985 #endif
1986         if (MODE_LOCAL_CHARS(globalmode)) {
1987             if (TerminalSpecialChars(sc) == 0) {
1988                 bol = 1;
1989                 break;
1990             }
1991         }
1992         if (my_want_state_is_wont(TELOPT_BINARY)) {
1993             switch (c) {
1994             case '\n':
1995                     /*
1996                      * If we are in CRMOD mode (\r ==> \n)
1997                      * on our local machine, then probably
1998                      * a newline (unix) is CRLF (TELNET).
1999                      */
2000                 if (MODE_LOCAL_CHARS(globalmode)) {
2001                     NETADD('\r');
2002                 }
2003                 NETADD('\n');
2004                 bol = flushline = 1;
2005                 break;
2006             case '\r':
2007                 if (!crlf) {
2008                     NET2ADD('\r', '\0');
2009                 } else {
2010                     NET2ADD('\r', '\n');
2011                 }
2012                 bol = flushline = 1;
2013                 break;
2014             case IAC:
2015                 NET2ADD(IAC, IAC);
2016                 break;
2017             default:
2018                 NETADD(c);
2019                 break;
2020             }
2021         } else if (c == IAC) {
2022             NET2ADD(IAC, IAC);
2023         } else {
2024             NETADD(c);
2025         }
2026     }
2027     if (count)
2028         ring_consumed(&ttyiring, count);
2029     return returnValue||count;          /* Non-zero if we did anything */
2030 }
2031 \f
2032 /*
2033  * Scheduler()
2034  *
2035  * Try to do something.
2036  *
2037  * If we do something useful, return 1; else return 0.
2038  *
2039  */
2040
2041 static int
2042 Scheduler(int block)
2043 {
2044                 /* One wants to be a bit careful about setting returnValue
2045                  * to one, since a one implies we did some useful work,
2046                  * and therefore probably won't be called to block next
2047                  */
2048     int returnValue;
2049     int netin, netout, netex, ttyin, ttyout;
2050
2051     /* Decide which rings should be processed */
2052
2053     netout = ring_full_count(&netoring) &&
2054             (flushline ||
2055                 (my_want_state_is_wont(TELOPT_LINEMODE)
2056 #ifdef  KLUDGELINEMODE
2057                         && (!kludgelinemode || my_want_state_is_do(TELOPT_SGA))
2058 #endif
2059                 ) ||
2060                         my_want_state_is_will(TELOPT_BINARY));
2061     ttyout = ring_full_count(&ttyoring);
2062
2063     ttyin = ring_empty_count(&ttyiring) && (clienteof == 0);
2064
2065     netin = !ISend && ring_empty_count(&netiring);
2066
2067     netex = !SYNCHing;
2068
2069     /* Call to system code to process rings */
2070
2071     returnValue = process_rings(netin, netout, netex, ttyin, ttyout, !block);
2072
2073     /* Now, look at the input rings, looking for work to do. */
2074
2075     if (ring_full_count(&ttyiring)) {
2076             returnValue |= telsnd();
2077     }
2078
2079     if (ring_full_count(&netiring)) {
2080         returnValue |= telrcv();
2081     }
2082     return returnValue;
2083 }
2084 \f
2085 #ifdef  AUTHENTICATION
2086 #define __unusedhere
2087 #else
2088 #define __unusedhere __unused
2089 #endif
2090 /*
2091  * Select from tty and network...
2092  */
2093 void
2094 telnet(char *user __unusedhere)
2095 {
2096     sys_telnet_init();
2097
2098 #ifdef  AUTHENTICATION
2099 #ifdef  ENCRYPTION
2100     {
2101         static char local_host[256] = { 0 };
2102
2103         if (!local_host[0]) {
2104                 gethostname(local_host, sizeof(local_host));
2105                 local_host[sizeof(local_host)-1] = 0;
2106         }
2107         auth_encrypt_init(local_host, hostname, "TELNET", 0);
2108         auth_encrypt_user(user);
2109     }
2110 #endif
2111 #endif
2112     if (telnetport > 0) {
2113 #ifdef  AUTHENTICATION
2114         if (autologin)
2115                 send_will(TELOPT_AUTHENTICATION, 1);
2116 #endif
2117 #ifdef  ENCRYPTION
2118         send_do(TELOPT_ENCRYPT, 1);
2119         send_will(TELOPT_ENCRYPT, 1);
2120 #endif  /* ENCRYPTION */
2121         send_do(TELOPT_SGA, 1);
2122         send_will(TELOPT_TTYPE, 1);
2123         send_will(TELOPT_NAWS, 1);
2124         send_will(TELOPT_TSPEED, 1);
2125         send_will(TELOPT_LFLOW, 1);
2126         send_will(TELOPT_LINEMODE, 1);
2127         send_will(TELOPT_NEW_ENVIRON, 1);
2128         send_do(TELOPT_STATUS, 1);
2129         if (env_getvalue((const unsigned char *)"DISPLAY"))
2130             send_will(TELOPT_XDISPLOC, 1);
2131         if (eight)
2132             tel_enter_binary(eight);
2133     }
2134
2135     for (;;) {
2136         int schedValue;
2137
2138         while ((schedValue = Scheduler(0)) != 0) {
2139             if (schedValue == -1) {
2140                 setcommandmode();
2141                 return;
2142             }
2143         }
2144
2145         if (Scheduler(1) == -1) {
2146             setcommandmode();
2147             return;
2148         }
2149     }
2150 }
2151 \f
2152 #if     0       /* XXX - this not being in is a bug */
2153 /*
2154  * nextitem()
2155  *
2156  *      Return the address of the next "item" in the TELNET data
2157  * stream.  This will be the address of the next character if
2158  * the current address is a user data character, or it will
2159  * be the address of the character following the TELNET command
2160  * if the current address is a TELNET IAC ("I Am a Command")
2161  * character.
2162  */
2163
2164 static char *
2165 nextitem(char *current)
2166 {
2167     if ((*current&0xff) != IAC) {
2168         return current+1;
2169     }
2170     switch (*(current+1)&0xff) {
2171     case DO:
2172     case DONT:
2173     case WILL:
2174     case WONT:
2175         return current+3;
2176     case SB:            /* loop forever looking for the SE */
2177         {
2178             char *look = current+2;
2179
2180             for (;;) {
2181                 if ((*look++&0xff) == IAC) {
2182                     if ((*look++&0xff) == SE) {
2183                         return look;
2184                     }
2185                 }
2186             }
2187         }
2188     default:
2189         return current+2;
2190     }
2191 }
2192 #endif  /* 0 */
2193
2194 /*
2195  * netclear()
2196  *
2197  *      We are about to do a TELNET SYNCH operation.  Clear
2198  * the path to the network.
2199  *
2200  *      Things are a bit tricky since we may have sent the first
2201  * byte or so of a previous TELNET command into the network.
2202  * So, we have to scan the network buffer from the beginning
2203  * until we are up to where we want to be.
2204  *
2205  *      A side effect of what we do, just to keep things
2206  * simple, is to clear the urgent data pointer.  The principal
2207  * caller should be setting the urgent data pointer AFTER calling
2208  * us in any case.
2209  */
2210
2211 static void
2212 netclear(void)
2213 {
2214         /* Deleted */
2215 }
2216 \f
2217 /*
2218  * These routines add various telnet commands to the data stream.
2219  */
2220
2221 static void
2222 doflush(void)
2223 {
2224     NET2ADD(IAC, DO);
2225     NETADD(TELOPT_TM);
2226     flushline = 1;
2227     flushout = 1;
2228     (void) ttyflush(1);                 /* Flush/drop output */
2229     /* do printoption AFTER flush, otherwise the output gets tossed... */
2230     printoption("SENT", DO, TELOPT_TM);
2231 }
2232
2233 void
2234 xmitAO(void)
2235 {
2236     NET2ADD(IAC, AO);
2237     printoption("SENT", IAC, AO);
2238     if (autoflush) {
2239         doflush();
2240     }
2241 }
2242
2243 void
2244 xmitEL(void)
2245 {
2246     NET2ADD(IAC, EL);
2247     printoption("SENT", IAC, EL);
2248 }
2249
2250 void
2251 xmitEC(void)
2252 {
2253     NET2ADD(IAC, EC);
2254     printoption("SENT", IAC, EC);
2255 }
2256
2257 int
2258 dosynch(char *ch __unused)
2259 {
2260     netclear();                 /* clear the path to the network */
2261     NETADD(IAC);
2262     setneturg();
2263     NETADD(DM);
2264     printoption("SENT", IAC, DM);
2265     return 1;
2266 }
2267
2268 int want_status_response = 0;
2269
2270 int
2271 get_status(char *ch __unused)
2272 {
2273     unsigned char tmp[16];
2274     unsigned char *cp;
2275
2276     if (my_want_state_is_dont(TELOPT_STATUS)) {
2277         printf("Remote side does not support STATUS option\n");
2278         return 0;
2279     }
2280     cp = tmp;
2281
2282     *cp++ = IAC;
2283     *cp++ = SB;
2284     *cp++ = TELOPT_STATUS;
2285     *cp++ = TELQUAL_SEND;
2286     *cp++ = IAC;
2287     *cp++ = SE;
2288     if (NETROOM() >= cp - tmp) {
2289         ring_supply_data(&netoring, tmp, cp-tmp);
2290         printsub('>', tmp+2, cp - tmp - 2);
2291     }
2292     ++want_status_response;
2293     return 1;
2294 }
2295
2296 void
2297 intp(void)
2298 {
2299     NET2ADD(IAC, IP);
2300     printoption("SENT", IAC, IP);
2301     flushline = 1;
2302     if (autoflush) {
2303         doflush();
2304     }
2305     if (autosynch) {
2306         dosynch(NULL);
2307     }
2308 }
2309
2310 void
2311 sendbrk(void)
2312 {
2313     NET2ADD(IAC, BREAK);
2314     printoption("SENT", IAC, BREAK);
2315     flushline = 1;
2316     if (autoflush) {
2317         doflush();
2318     }
2319     if (autosynch) {
2320         dosynch(NULL);
2321     }
2322 }
2323
2324 void
2325 sendabort(void)
2326 {
2327     NET2ADD(IAC, ABORT);
2328     printoption("SENT", IAC, ABORT);
2329     flushline = 1;
2330     if (autoflush) {
2331         doflush();
2332     }
2333     if (autosynch) {
2334         dosynch(NULL);
2335     }
2336 }
2337
2338 void
2339 sendsusp(void)
2340 {
2341     NET2ADD(IAC, SUSP);
2342     printoption("SENT", IAC, SUSP);
2343     flushline = 1;
2344     if (autoflush) {
2345         doflush();
2346     }
2347     if (autosynch) {
2348         dosynch(NULL);
2349     }
2350 }
2351
2352 void
2353 sendeof(void)
2354 {
2355     NET2ADD(IAC, xEOF);
2356     printoption("SENT", IAC, xEOF);
2357 }
2358
2359 void
2360 sendayt(void)
2361 {
2362     NET2ADD(IAC, AYT);
2363     printoption("SENT", IAC, AYT);
2364 }
2365
2366 /*
2367  * Send a window size update to the remote system.
2368  */
2369
2370 void
2371 sendnaws(void)
2372 {
2373     long rows, cols;
2374     unsigned char tmp[16];
2375     unsigned char *cp;
2376
2377     if (my_state_is_wont(TELOPT_NAWS))
2378         return;
2379
2380 #define PUTSHORT(cp, x) { if ((*cp++ = ((x)>>8)&0xff) == IAC) *cp++ = IAC; \
2381                             if ((*cp++ = ((x))&0xff) == IAC) *cp++ = IAC; }
2382
2383     if (TerminalWindowSize(&rows, &cols) == 0) {        /* Failed */
2384         return;
2385     }
2386
2387     cp = tmp;
2388
2389     *cp++ = IAC;
2390     *cp++ = SB;
2391     *cp++ = TELOPT_NAWS;
2392     PUTSHORT(cp, cols);
2393     PUTSHORT(cp, rows);
2394     *cp++ = IAC;
2395     *cp++ = SE;
2396     if (NETROOM() >= cp - tmp) {
2397         ring_supply_data(&netoring, tmp, cp-tmp);
2398         printsub('>', tmp+2, cp - tmp - 2);
2399     }
2400 }
2401
2402 void
2403 tel_enter_binary(int rw)
2404 {
2405     if (rw&1)
2406         send_do(TELOPT_BINARY, 1);
2407     if (rw&2)
2408         send_will(TELOPT_BINARY, 1);
2409 }
2410
2411 void
2412 tel_leave_binary(int rw)
2413 {
2414     if (rw&1)
2415         send_dont(TELOPT_BINARY, 1);
2416     if (rw&2)
2417         send_wont(TELOPT_BINARY, 1);
2418 }