libexec/telnetd/utility.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)utility.c        8.4 (Berkeley) 5/30/95
  30  * $FreeBSD: src/crypto/telnet/telnetd/utility.c,v 1.5.2.4 2002/04/13 10:59:09 markm Exp $
  31  */
  32
  33 #if defined(__FreeBSD__) || defined(__DragonFly__)
  34 #include <locale.h>
  35 #include <sys/utsname.h>
  36 #endif
  37 #include <string.h>
  38 #define PRINTOPTIONS
  39 #include "telnetd.h"
  40
  41 #ifdef  AUTHENTICATION
  42 #include <libtelnet/auth.h>
  43 #endif
  44 #ifdef  ENCRYPTION
  45 #include <libtelnet/encrypt.h>
  46 #endif
  47
  48 extern char     line[16];
  49
  50 /*
  51  * utility functions performing io related tasks
  52  */
  53
  54 /*
  55  * ttloop
  56  *
  57  *      A small subroutine to flush the network output buffer, get some data
  58  * from the network, and pass it through the telnet state machine.  We
  59  * also flush the pty input buffer (by dropping its data) if it becomes
  60  * too full.
  61  */
  62
  63 void
  64 ttloop(void)
  65 {
  66
  67     DIAG(TD_REPORT, output_data("td: ttloop\r\n"));
  68     if (nfrontp - nbackp > 0) {
  69         netflush();
  70     }
  71     ncc = read(net, netibuf, sizeof netibuf);
  72     if (ncc < 0) {
  73         syslog(LOG_INFO, "ttloop:  read: %m");
  74         exit(1);
  75     } else if (ncc == 0) {
  76         syslog(LOG_INFO, "ttloop:  peer died: %m");
  77         exit(1);
  78     }
  79     DIAG(TD_REPORT, output_data("td: ttloop read %d chars\r\n", ncc));
  80     netip = netibuf;
  81     telrcv();                   /* state machine */
  82     if (ncc > 0) {
  83         pfrontp = pbackp = ptyobuf;
  84         telrcv();
  85     }
  86 }  /* end of ttloop */
  87
  88 /*
  89  * Check a descriptor to see if out of band data exists on it.
  90  */
  91 int
  92 stilloob(int s)
  93 {
  94     static struct timeval timeout = { 0, 0 };
  95     fd_set      excepts;
  96     int value;
  97
  98     do {
  99         FD_ZERO(&excepts);
 100         FD_SET(s, &excepts);
 101         memset((char *)&timeout, 0, sizeof timeout);
 102         value = select(s+1, NULL, NULL, &excepts, &timeout);
 103     } while ((value == -1) && (errno == EINTR));
 104
 105     if (value < 0) {
 106         fatalperror(pty, "select");
 107     }
 108     if (FD_ISSET(s, &excepts)) {
 109         return 1;
 110     } else {
 111         return 0;
 112     }
 113 }
 114
 115 void
 116 ptyflush(void)
 117 {
 118         int n;
 119
 120         if ((n = pfrontp - pbackp) > 0) {
 121                 DIAG(TD_REPORT | TD_PTYDATA,
 122                     output_data("td: ptyflush %d chars\r\n", n));
 123                 DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
 124                 n = write(pty, pbackp, n);
 125         }
 126         if (n < 0) {
 127                 if (errno == EWOULDBLOCK || errno == EINTR)
 128                         return;
 129                 cleanup(0);
 130         }
 131         pbackp += n;
 132         if (pbackp == pfrontp)
 133                 pbackp = pfrontp = ptyobuf;
 134 }
 135
 136 /*
 137  * nextitem()
 138  *
 139  *      Return the address of the next "item" in the TELNET data
 140  * stream.  This will be the address of the next character if
 141  * the current address is a user data character, or it will
 142  * be the address of the character following the TELNET command
 143  * if the current address is a TELNET IAC ("I Am a Command")
 144  * character.
 145  */
 146 static char *
 147 nextitem(char *current)
 148 {
 149     if ((*current&0xff) != IAC) {
 150         return current+1;
 151     }
 152     switch (*(current+1)&0xff) {
 153     case DO:
 154     case DONT:
 155     case WILL:
 156     case WONT:
 157         return current+3;
 158     case SB:            /* loop forever looking for the SE */
 159         {
 160             char *look = current+2;
 161
 162             for (;;) {
 163                 if ((*look++&0xff) == IAC) {
 164                     if ((*look++&0xff) == SE) {
 165                         return look;
 166                     }
 167                 }
 168             }
 169         }
 170     default:
 171         return current+2;
 172     }
 173 }  /* end of nextitem */
 174
 175 /*
 176  * netclear()
 177  *
 178  *      We are about to do a TELNET SYNCH operation.  Clear
 179  * the path to the network.
 180  *
 181  *      Things are a bit tricky since we may have sent the first
 182  * byte or so of a previous TELNET command into the network.
 183  * So, we have to scan the network buffer from the beginning
 184  * until we are up to where we want to be.
 185  *
 186  *      A side effect of what we do, just to keep things
 187  * simple, is to clear the urgent data pointer.  The principal
 188  * caller should be setting the urgent data pointer AFTER calling
 189  * us in any case.
 190  */
 191 void
 192 netclear(void)
 193 {
 194     char *thisitem, *next;
 195     char *good;
 196 #define wewant(p)       ((nfrontp > p) && ((*p&0xff) == IAC) && \
 197                                 ((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
 198
 199 #ifdef  ENCRYPTION
 200     thisitem = nclearto > netobuf ? nclearto : netobuf;
 201 #else   /* ENCRYPTION */
 202     thisitem = netobuf;
 203 #endif  /* ENCRYPTION */
 204
 205     while ((next = nextitem(thisitem)) <= nbackp) {
 206         thisitem = next;
 207     }
 208
 209     /* Now, thisitem is first before/at boundary. */
 210
 211 #ifdef  ENCRYPTION
 212     good = nclearto > netobuf ? nclearto : netobuf;
 213 #else   /* ENCRYPTION */
 214     good = netobuf;     /* where the good bytes go */
 215 #endif  /* ENCRYPTION */
 216
 217     while (nfrontp > thisitem) {
 218         if (wewant(thisitem)) {
 219             int length;
 220
 221             next = thisitem;
 222             do {
 223                 next = nextitem(next);
 224             } while (wewant(next) && (nfrontp > next));
 225             length = next-thisitem;
 226             memmove(good, thisitem, length);
 227             good += length;
 228             thisitem = next;
 229         } else {
 230             thisitem = nextitem(thisitem);
 231         }
 232     }
 233
 234     nbackp = netobuf;
 235     nfrontp = good;             /* next byte to be sent */
 236     neturg = 0;
 237 }  /* end of netclear */
 238
 239 /*
 240  *  netflush
 241  *              Send as much data as possible to the network,
 242  *      handling requests for urgent data.
 243  */
 244 void
 245 netflush(void)
 246 {
 247     int n;
 248     extern int not42;
 249
 250     while ((n = nfrontp - nbackp) > 0) {
 251 #if 0
 252         /* XXX This causes output_data() to recurse and die */
 253         DIAG(TD_REPORT, {
 254             n += output_data("td: netflush %d chars\r\n", n);
 255         });
 256 #endif
 257 #ifdef  ENCRYPTION
 258         if (encrypt_output) {
 259                 char *s = nclearto ? nclearto : nbackp;
 260                 if (nfrontp - s > 0) {
 261                         (*encrypt_output)((unsigned char *)s, nfrontp-s);
 262                         nclearto = nfrontp;
 263                 }
 264         }
 265 #endif  /* ENCRYPTION */
 266         /*
 267          * if no urgent data, or if the other side appears to be an
 268          * old 4.2 client (and thus unable to survive TCP urgent data),
 269          * write the entire buffer in non-OOB mode.
 270          */
 271         if ((neturg == 0) || (not42 == 0)) {
 272             n = write(net, nbackp, n);  /* normal write */
 273         } else {
 274             n = neturg - nbackp;
 275             /*
 276              * In 4.2 (and 4.3) systems, there is some question about
 277              * what byte in a sendOOB operation is the "OOB" data.
 278              * To make ourselves compatible, we only send ONE byte
 279              * out of band, the one WE THINK should be OOB (though
 280              * we really have more the TCP philosophy of urgent data
 281              * rather than the Unix philosophy of OOB data).
 282              */
 283             if (n > 1) {
 284                 n = send(net, nbackp, n-1, 0);  /* send URGENT all by itself */
 285             } else {
 286                 n = send(net, nbackp, n, MSG_OOB);      /* URGENT data */
 287             }
 288         }
 289         if (n == -1) {
 290             if (errno == EWOULDBLOCK || errno == EINTR)
 291                 continue;
 292             cleanup(0);
 293             /* NOTREACHED */
 294         }
 295         nbackp += n;
 296 #ifdef  ENCRYPTION
 297         if (nbackp > nclearto)
 298             nclearto = 0;
 299 #endif  /* ENCRYPTION */
 300         if (nbackp >= neturg) {
 301             neturg = 0;
 302         }
 303         if (nbackp == nfrontp) {
 304             nbackp = nfrontp = netobuf;
 305 #ifdef  ENCRYPTION
 306             nclearto = 0;
 307 #endif  /* ENCRYPTION */
 308         }
 309     }
 310     return;
 311 }  /* end of netflush */
 312
 313
 314 /*
 315  * miscellaneous functions doing a variety of little jobs follow ...
 316  */
 317
 318
 319 void
 320 fatalmsg(int f, const char *msg)
 321 {
 322         char buf[BUFSIZ];
 323
 324         (void) snprintf(buf, sizeof(buf), "telnetd: %s.\r\n", msg);
 325 #ifdef  ENCRYPTION
 326         if (encrypt_output) {
 327                 /*
 328                  * Better turn off encryption first....
 329                  * Hope it flushes...
 330                  */
 331                 encrypt_send_end();
 332                 netflush();
 333         }
 334 #endif  /* ENCRYPTION */
 335         (void) write(f, buf, (int)strlen(buf));
 336         sleep(1);       /*XXX*/
 337         exit(1);
 338 }
 339
 340 void
 341 fatalperror(int f, const char *msg)
 342 {
 343         char buf[BUFSIZ];
 344
 345         (void) snprintf(buf, sizeof(buf), "%s: %s", msg, strerror(errno));
 346         fatalmsg(f, buf);
 347 }
 348
 349 char editedhost[32];
 350
 351 void
 352 edithost(char *pat, char *host)
 353 {
 354         char *res = editedhost;
 355
 356         if (!pat)
 357                 pat = strdup("");
 358         while (*pat) {
 359                 switch (*pat) {
 360
 361                 case '#':
 362                         if (*host)
 363                                 host++;
 364                         break;
 365
 366                 case '@':
 367                         if (*host)
 368                                 *res++ = *host++;
 369                         break;
 370
 371                 default:
 372                         *res++ = *pat;
 373                         break;
 374                 }
 375                 if (res == &editedhost[sizeof editedhost - 1]) {
 376                         *res = '\0';
 377                         return;
 378                 }
 379                 pat++;
 380         }
 381         if (*host)
 382                 (void) strncpy(res, host,
 383                                 sizeof editedhost - (res - editedhost) -1);
 384         else
 385                 *res = '\0';
 386         editedhost[sizeof editedhost - 1] = '\0';
 387 }
 388
 389 static char *putlocation;
 390
 391 static void
 392 putstr(const char *s)
 393 {
 394
 395         while (*s)
 396                 putchr(*s++);
 397 }
 398
 399 void
 400 putchr(int cc)
 401 {
 402         *putlocation++ = cc;
 403 }
 404
 405 #if defined(__FreeBSD__) || defined(__DragonFly__)
 406 static char fmtstr[] = { "%+" };
 407 #else
 408 static char fmtstr[] = { "%l:%M%P on %A, %d %B %Y" };
 409 #endif
 410
 411 void
 412 putf(char *cp, char *where)
 413 {
 414         char *slash;
 415         time_t t;
 416         char db[100];
 417 #if defined(__FreeBSD__) || defined(__DragonFly__)
 418         static struct utsname kerninfo;
 419
 420         if (!*kerninfo.sysname)
 421                 uname(&kerninfo);
 422 #endif
 423
 424         putlocation = where;
 425
 426         while (*cp) {
 427                 if (*cp =='\n') {
 428                         putstr("\r\n");
 429                         cp++;
 430                         continue;
 431                 } else if (*cp != '%') {
 432                         putchr(*cp++);
 433                         continue;
 434                 }
 435                 switch (*++cp) {
 436
 437                 case 't':
 438 #ifdef  STREAMSPTY
 439                         /* names are like /dev/pts/2 -- we want pts/2 */
 440                         slash = strchr(line+1, '/');
 441 #else
 442                         slash = strrchr(line, '/');
 443 #endif
 444                         if (slash == (char *) 0)
 445                                 putstr(line);
 446                         else
 447                                 putstr(&slash[1]);
 448                         break;
 449
 450                 case 'h':
 451                         putstr(editedhost);
 452                         break;
 453
 454                 case 'd':
 455 #if defined(__FreeBSD__) || defined(__DragonFly__)
 456                         setlocale(LC_TIME, "");
 457 #endif
 458                         (void)time(&t);
 459                         (void)strftime(db, sizeof(db), fmtstr, localtime(&t));
 460                         putstr(db);
 461                         break;
 462
 463 #if defined(__FreeBSD__) || defined(__DragonFly__)
 464                 case 's':
 465                         putstr(kerninfo.sysname);
 466                         break;
 467
 468                 case 'm':
 469                         putstr(kerninfo.machine);
 470                         break;
 471
 472                 case 'r':
 473                         putstr(kerninfo.release);
 474                         break;
 475
 476                 case 'v':
 477                         putstr(kerninfo.version);
 478                         break;
 479 #endif
 480
 481                 case '%':
 482                         putchr('%');
 483                         break;
 484                 }
 485                 cp++;
 486         }
 487 }
 488
 489 #ifdef DIAGNOSTICS
 490 /*
 491  * Print telnet options and commands in plain text, if possible.
 492  */
 493 void
 494 printoption(const char *fmt, int option)
 495 {
 496         if (TELOPT_OK(option))
 497                 output_data("%s %s\r\n", fmt, TELOPT(option));
 498         else if (TELCMD_OK(option))
 499                 output_data("%s %s\r\n", fmt, TELCMD(option));
 500         else
 501                 output_data("%s %d\r\n", fmt, option);
 502         return;
 503 }
 504
 505 void
 506 printsub(char direction, unsigned char *pointer, int length)
 507 {
 508     int i = 0;
 509
 510         if (!(diagnostic & TD_OPTIONS))
 511                 return;
 512
 513         if (direction) {
 514             output_data("td: %s suboption ",
 515                                         direction == '<' ? "recv" : "send");
 516             if (length >= 3) {
 517                 int j;
 518
 519                 i = pointer[length-2];
 520                 j = pointer[length-1];
 521
 522                 if (i != IAC || j != SE) {
 523                     output_data("(terminated by ");
 524                     if (TELOPT_OK(i))
 525                         output_data("%s ", TELOPT(i));
 526                     else if (TELCMD_OK(i))
 527                         output_data("%s ", TELCMD(i));
 528                     else
 529                         output_data("%d ", i);
 530                     if (TELOPT_OK(j))
 531                         output_data("%s", TELOPT(j));
 532                     else if (TELCMD_OK(j))
 533                         output_data("%s", TELCMD(j));
 534                     else
 535                         output_data("%d", j);
 536                     output_data(", not IAC SE!) ");
 537                 }
 538             }
 539             length -= 2;
 540         }
 541         if (length < 1) {
 542             output_data("(Empty suboption??\?)");
 543             return;
 544         }
 545         switch (pointer[0]) {
 546         case TELOPT_TTYPE:
 547             output_data("TERMINAL-TYPE ");
 548             switch (pointer[1]) {
 549             case TELQUAL_IS:
 550                 output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
 551                 break;
 552             case TELQUAL_SEND:
 553                 output_data("SEND");
 554                 break;
 555             default:
 556                 output_data(
 557                                 "- unknown qualifier %d (0x%x).",
 558                                 pointer[1], pointer[1]);
 559             }
 560             break;
 561         case TELOPT_TSPEED:
 562             output_data("TERMINAL-SPEED");
 563             if (length < 2) {
 564                 output_data(" (empty suboption??\?)");
 565                 break;
 566             }
 567             switch (pointer[1]) {
 568             case TELQUAL_IS:
 569                 output_data(" IS %.*s", length-2, (char *)pointer+2);
 570                 break;
 571             default:
 572                 if (pointer[1] == 1)
 573                     output_data(" SEND");
 574                 else
 575                     output_data(" %d (unknown)", pointer[1]);
 576                 for (i = 2; i < length; i++) {
 577                     output_data(" ?%d?", pointer[i]);
 578                 }
 579                 break;
 580             }
 581             break;
 582
 583         case TELOPT_LFLOW:
 584             output_data("TOGGLE-FLOW-CONTROL");
 585             if (length < 2) {
 586                 output_data(" (empty suboption??\?)");
 587                 break;
 588             }
 589             switch (pointer[1]) {
 590             case LFLOW_OFF:
 591                 output_data(" OFF"); break;
 592             case LFLOW_ON:
 593                 output_data(" ON"); break;
 594             case LFLOW_RESTART_ANY:
 595                 output_data(" RESTART-ANY"); break;
 596             case LFLOW_RESTART_XON:
 597                 output_data(" RESTART-XON"); break;
 598             default:
 599                 output_data(" %d (unknown)", pointer[1]);
 600             }
 601             for (i = 2; i < length; i++) {
 602                 output_data(" ?%d?", pointer[i]);
 603             }
 604             break;
 605
 606         case TELOPT_NAWS:
 607             output_data("NAWS");
 608             if (length < 2) {
 609                 output_data(" (empty suboption??\?)");
 610                 break;
 611             }
 612             if (length == 2) {
 613                 output_data(" ?%d?", pointer[1]);
 614                 break;
 615             }
 616             output_data(" %d %d (%d)",
 617                 pointer[1], pointer[2],
 618                 (int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
 619             if (length == 4) {
 620                 output_data(" ?%d?", pointer[3]);
 621                 break;
 622             }
 623             output_data(" %d %d (%d)",
 624                 pointer[3], pointer[4],
 625                 (int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
 626             for (i = 5; i < length; i++) {
 627                 output_data(" ?%d?", pointer[i]);
 628             }
 629             break;
 630
 631         case TELOPT_LINEMODE:
 632             output_data("LINEMODE ");
 633             if (length < 2) {
 634                 output_data(" (empty suboption??\?)");
 635                 break;
 636             }
 637             switch (pointer[1]) {
 638             case WILL:
 639                 output_data("WILL ");
 640                 goto common;
 641             case WONT:
 642                 output_data("WONT ");
 643                 goto common;
 644             case DO:
 645                 output_data("DO ");
 646                 goto common;
 647             case DONT:
 648                 output_data("DONT ");
 649             common:
 650                 if (length < 3) {
 651                     output_data("(no option??\?)");
 652                     break;
 653                 }
 654                 switch (pointer[2]) {
 655                 case LM_FORWARDMASK:
 656                     output_data("Forward Mask");
 657                     for (i = 3; i < length; i++) {
 658                         output_data(" %x", pointer[i]);
 659                     }
 660                     break;
 661                 default:
 662                     output_data("%d (unknown)", pointer[2]);
 663                     for (i = 3; i < length; i++) {
 664                         output_data(" %d", pointer[i]);
 665                     }
 666                     break;
 667                 }
 668                 break;
 669
 670             case LM_SLC:
 671                 output_data("SLC");
 672                 for (i = 2; i < length - 2; i += 3) {
 673                     if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
 674                         output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
 675                     else
 676                         output_data(" %d", pointer[i+SLC_FUNC]);
 677                     switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
 678                     case SLC_NOSUPPORT:
 679                         output_data(" NOSUPPORT"); break;
 680                     case SLC_CANTCHANGE:
 681                         output_data(" CANTCHANGE"); break;
 682                     case SLC_VARIABLE:
 683                         output_data(" VARIABLE"); break;
 684                     case SLC_DEFAULT:
 685                         output_data(" DEFAULT"); break;
 686                     }
 687                     output_data("%s%s%s",
 688                         pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
 689                         pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
 690                         pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
 691                     if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
 692                                                 SLC_FLUSHOUT| SLC_LEVELBITS)) {
 693                         output_data("(0x%x)", pointer[i+SLC_FLAGS]);
 694                     }
 695                     output_data(" %d;", pointer[i+SLC_VALUE]);
 696                     if ((pointer[i+SLC_VALUE] == IAC) &&
 697                         (pointer[i+SLC_VALUE+1] == IAC))
 698                                 i++;
 699                 }
 700                 for (; i < length; i++) {
 701                     output_data(" ?%d?", pointer[i]);
 702                 }
 703                 break;
 704
 705             case LM_MODE:
 706                 output_data("MODE ");
 707                 if (length < 3) {
 708                     output_data("(no mode??\?)");
 709                     break;
 710                 }
 711                 {
 712                     char tbuf[32];
 713                     sprintf(tbuf, "%s%s%s%s%s",
 714                         pointer[2]&MODE_EDIT ? "|EDIT" : "",
 715                         pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
 716                         pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
 717                         pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
 718                         pointer[2]&MODE_ACK ? "|ACK" : "");
 719                     output_data("%s", tbuf[1] ? &tbuf[1] : "0");
 720                 }
 721                 if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) {
 722                     output_data(" (0x%x)", pointer[2]);
 723                 }
 724                 for (i = 3; i < length; i++) {
 725                     output_data(" ?0x%x?", pointer[i]);
 726                 }
 727                 break;
 728             default:
 729                 output_data("%d (unknown)", pointer[1]);
 730                 for (i = 2; i < length; i++) {
 731                     output_data(" %d", pointer[i]);
 732                 }
 733             }
 734             break;
 735
 736         case TELOPT_STATUS: {
 737             const char *cp;
 738             int j, k;
 739
 740             output_data("STATUS");
 741
 742             switch (pointer[1]) {
 743             default:
 744                 if (pointer[1] == TELQUAL_SEND)
 745                     output_data(" SEND");
 746                 else
 747                     output_data(" %d (unknown)", pointer[1]);
 748                 for (i = 2; i < length; i++) {
 749                     output_data(" ?%d?", pointer[i]);
 750                 }
 751                 break;
 752             case TELQUAL_IS:
 753                 output_data(" IS\r\n");
 754
 755                 for (i = 2; i < length; i++) {
 756                     switch(pointer[i]) {
 757                     case DO:    cp = "DO"; goto common2;
 758                     case DONT:  cp = "DONT"; goto common2;
 759                     case WILL:  cp = "WILL"; goto common2;
 760                     case WONT:  cp = "WONT"; goto common2;
 761                     common2:
 762                         i++;
 763                         if (TELOPT_OK(pointer[i]))
 764                             output_data(" %s %s", cp, TELOPT(pointer[i]));
 765                         else
 766                             output_data(" %s %d", cp, pointer[i]);
 767
 768                         output_data("\r\n");
 769                         break;
 770
 771                     case SB:
 772                         output_data(" SB ");
 773                         i++;
 774                         j = k = i;
 775                         while (j < length) {
 776                             if (pointer[j] == SE) {
 777                                 if (j+1 == length)
 778                                     break;
 779                                 if (pointer[j+1] == SE)
 780                                     j++;
 781                                 else
 782                                     break;
 783                             }
 784                             pointer[k++] = pointer[j++];
 785                         }
 786                         printsub(0, &pointer[i], k - i);
 787                         if (i < length) {
 788                             output_data(" SE");
 789                             i = j;
 790                         } else
 791                             i = j - 1;
 792
 793                         output_data("\r\n");
 794
 795                         break;
 796
 797                     default:
 798                         output_data(" %d", pointer[i]);
 799                         break;
 800                     }
 801                 }
 802                 break;
 803             }
 804             break;
 805           }
 806
 807         case TELOPT_XDISPLOC:
 808             output_data("X-DISPLAY-LOCATION ");
 809             switch (pointer[1]) {
 810             case TELQUAL_IS:
 811                 output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
 812                 break;
 813             case TELQUAL_SEND:
 814                 output_data("SEND");
 815                 break;
 816             default:
 817                 output_data("- unknown qualifier %d (0x%x).",
 818                                 pointer[1], pointer[1]);
 819             }
 820             break;
 821
 822         case TELOPT_NEW_ENVIRON:
 823             output_data("NEW-ENVIRON ");
 824             goto env_common1;
 825         case TELOPT_OLD_ENVIRON:
 826             output_data("OLD-ENVIRON");
 827         env_common1:
 828             switch (pointer[1]) {
 829             case TELQUAL_IS:
 830                 output_data("IS ");
 831                 goto env_common;
 832             case TELQUAL_SEND:
 833                 output_data("SEND ");
 834                 goto env_common;
 835             case TELQUAL_INFO:
 836                 output_data("INFO ");
 837             env_common:
 838                 {
 839                     int noquote = 2;
 840                     for (i = 2; i < length; i++ ) {
 841                         switch (pointer[i]) {
 842                         case NEW_ENV_VAR:
 843                             output_data("%s", "\" VAR " + noquote);
 844                             noquote = 2;
 845                             break;
 846
 847                         case NEW_ENV_VALUE:
 848                             output_data("%s", "\" VALUE " + noquote);
 849                             noquote = 2;
 850                             break;
 851
 852                         case ENV_ESC:
 853                             output_data("%s", "\" ESC " + noquote);
 854                             noquote = 2;
 855                             break;
 856
 857                         case ENV_USERVAR:
 858                             output_data("%s", "\" USERVAR " + noquote);
 859                             noquote = 2;
 860                             break;
 861
 862                         default:
 863                             if (isprint(pointer[i]) && pointer[i] != '"') {
 864                                 if (noquote) {
 865                                     output_data("\"");
 866                                     noquote = 0;
 867                                 }
 868                                 output_data("%c", pointer[i]);
 869                             } else {
 870                                 output_data("\" %03o " + noquote,
 871                                                         pointer[i]);
 872                                 noquote = 2;
 873                             }
 874                             break;
 875                         }
 876                     }
 877                     if (!noquote)
 878                         output_data("\"");
 879                     break;
 880                 }
 881             }
 882             break;
 883
 884 #ifdef  AUTHENTICATION
 885         case TELOPT_AUTHENTICATION:
 886             output_data("AUTHENTICATION");
 887
 888             if (length < 2) {
 889                 output_data(" (empty suboption??\?)");
 890                 break;
 891             }
 892             switch (pointer[1]) {
 893             case TELQUAL_REPLY:
 894             case TELQUAL_IS:
 895                 output_data(" %s ", (pointer[1] == TELQUAL_IS) ?
 896                                                         "IS" : "REPLY");
 897                 if (AUTHTYPE_NAME_OK(pointer[2]))
 898                     output_data("%s ", AUTHTYPE_NAME(pointer[2]));
 899                 else
 900                     output_data("%d ", pointer[2]);
 901                 if (length < 3) {
 902                     output_data("(partial suboption??\?)");
 903                     break;
 904                 }
 905                 output_data("%s|%s",
 906                         ((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
 907                         "CLIENT" : "SERVER",
 908                         ((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
 909                         "MUTUAL" : "ONE-WAY");
 910
 911                 {
 912                     char buf[512];
 913                     auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
 914                     output_data("%s", buf);
 915                 }
 916                 break;
 917
 918             case TELQUAL_SEND:
 919                 i = 2;
 920                 output_data(" SEND ");
 921                 while (i < length) {
 922                     if (AUTHTYPE_NAME_OK(pointer[i]))
 923                         output_data("%s ", AUTHTYPE_NAME(pointer[i]));
 924                     else
 925                         output_data("%d ", pointer[i]);
 926                     if (++i >= length) {
 927                         output_data("(partial suboption??\?)");
 928                         break;
 929                     }
 930                     output_data("%s|%s ",
 931                         ((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
 932                                                         "CLIENT" : "SERVER",
 933                         ((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
 934                                                         "MUTUAL" : "ONE-WAY");
 935                     ++i;
 936                 }
 937                 break;
 938
 939             case TELQUAL_NAME:
 940                 output_data(" NAME \"%.*s\"", length - 2, pointer + 2);
 941                 break;
 942
 943             default:
 944                     for (i = 2; i < length; i++) {
 945                         output_data(" ?%d?", pointer[i]);
 946                     }
 947                     break;
 948             }
 949             break;
 950 #endif
 951
 952 #ifdef  ENCRYPTION
 953         case TELOPT_ENCRYPT:
 954             output_data("ENCRYPT");
 955             if (length < 2) {
 956                 output_data(" (empty suboption??\?)");
 957                 break;
 958             }
 959             switch (pointer[1]) {
 960             case ENCRYPT_START:
 961                 output_data(" START");
 962                 break;
 963
 964             case ENCRYPT_END:
 965                 output_data(" END");
 966                 break;
 967
 968             case ENCRYPT_REQSTART:
 969                 output_data(" REQUEST-START");
 970                 break;
 971
 972             case ENCRYPT_REQEND:
 973                 output_data(" REQUEST-END");
 974                 break;
 975
 976             case ENCRYPT_IS:
 977             case ENCRYPT_REPLY:
 978                 output_data(" %s ", (pointer[1] == ENCRYPT_IS) ?
 979                                                         "IS" : "REPLY");
 980                 if (length < 3) {
 981                     output_data(" (partial suboption??\?)");
 982                     break;
 983                 }
 984                 if (ENCTYPE_NAME_OK(pointer[2]))
 985                     output_data("%s ", ENCTYPE_NAME(pointer[2]));
 986                 else
 987                     output_data(" %d (unknown)", pointer[2]);
 988
 989                 {
 990                     char buf[512];
 991                     encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
 992                     output_data("%s", buf);
 993                 }
 994                 break;
 995
 996             case ENCRYPT_SUPPORT:
 997                 i = 2;
 998                 output_data(" SUPPORT ");
 999                 while (i < length) {
1000                     if (ENCTYPE_NAME_OK(pointer[i]))
1001                         output_data("%s ", ENCTYPE_NAME(pointer[i]));
1002                     else
1003                         output_data("%d ", pointer[i]);
1004                     i++;
1005                 }
1006                 break;
1007
1008             case ENCRYPT_ENC_KEYID:
1009                 output_data(" ENC_KEYID");
1010                 goto encommon;
1011
1012             case ENCRYPT_DEC_KEYID:
1013                 output_data(" DEC_KEYID");
1014                 goto encommon;
1015
1016             default:
1017                 output_data(" %d (unknown)", pointer[1]);
1018             encommon:
1019                 for (i = 2; i < length; i++) {
1020                     output_data(" %d", pointer[i]);
1021                 }
1022                 break;
1023             }
1024             break;
1025 #endif  /* ENCRYPTION */
1026
1027         default:
1028             if (TELOPT_OK(pointer[0]))
1029                 output_data("%s (unknown)", TELOPT(pointer[0]));
1030             else
1031                 output_data("%d (unknown)", pointer[i]);
1032             for (i = 1; i < length; i++) {
1033                 output_data(" %d", pointer[i]);
1034             }
1035             break;
1036         }
1037         output_data("\r\n");
1038 }
1039
1040 /*
1041  * Dump a data buffer in hex and ascii to the output data stream.
1042  */
1043 void
1044 printdata(const char *tag, char *ptr, int cnt)
1045 {
1046         int i;
1047         char xbuf[30];
1048
1049         while (cnt) {
1050                 /* flush net output buffer if no room for new data) */
1051                 if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1052                         netflush();
1053                 }
1054
1055                 /* add a line of output */
1056                 output_data("%s: ", tag);
1057                 for (i = 0; i < 20 && cnt; i++) {
1058                         output_data("%02x", *ptr);
1059                         if (isprint(*ptr)) {
1060                                 xbuf[i] = *ptr;
1061                         } else {
1062                                 xbuf[i] = '.';
1063                         }
1064                         if (i % 2) {
1065                                 output_data(" ");
1066                         }
1067                         cnt--;
1068                         ptr++;
1069                 }
1070                 xbuf[i] = '\0';
1071                 output_data(" %s\r\n", xbuf );
1072         }
1073 }
1074 #endif /* DIAGNOSTICS */