libexec/telnetd/utility.c

   1 /*      $NetBSD: utility.c,v 1.30 2006/10/07 18:26:40 elad Exp $        */
   2
   3 /*
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)utility.c   8.4 (Berkeley) 5/30/95";
  36 #else
  37 __RCSID("$NetBSD: utility.c,v 1.30 2006/10/07 18:26:40 elad Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <sys/utsname.h>
  42 #include <ctype.h>
  43 #define PRINTOPTIONS
  44 #include "telnetd.h"
  45
  46 char *nextitem(char *);
  47 void putstr(char *);
  48
  49 extern int not42;
  50
  51 /*
  52  * utility functions performing io related tasks
  53  */
  54
  55 /*
  56  * ttloop
  57  *
  58  *      A small subroutine to flush the network output buffer, get some data
  59  * from the network, and pass it through the telnet state machine.  We
  60  * also flush the pty input buffer (by dropping its data) if it becomes
  61  * too full.
  62  */
  63
  64 void
  65 ttloop(void)
  66 {
  67
  68     DIAG(TD_REPORT, {output_data("td: ttloop\r\n");});
  69     if (nfrontp - nbackp) {
  70         netflush();
  71     }
  72     ncc = read(net, netibuf, sizeof netibuf);
  73     if (ncc < 0) {
  74         syslog(LOG_ERR, "ttloop:  read: %m");
  75         exit(1);
  76     } else if (ncc == 0) {
  77         syslog(LOG_INFO, "ttloop:  unexpected EOF from peer");
  78         exit(1);
  79     }
  80     DIAG(TD_REPORT, {output_data("td: ttloop read %d chars\r\n", ncc);});
  81     netip = netibuf;
  82     telrcv();                   /* state machine */
  83     if (ncc > 0) {
  84         pfrontp = pbackp = ptyobuf;
  85         telrcv();
  86     }
  87 }  /* end of ttloop */
  88
  89 /*
  90  * Check a descriptor to see if out of band data exists on it.
  91  */
  92 int
  93 stilloob(int s /* socket number */)
  94 {
  95     struct pollfd set[1];
  96     int value;
  97
  98     set[0].fd = s;
  99     set[0].events = POLLPRI;
 100     do {
 101         value = poll(set, 1, 0);
 102     } while ((value == -1) && (errno == EINTR));
 103
 104     if (value < 0) {
 105         fatalperror(pty, "poll");
 106     }
 107     if (set[0].revents & POLLPRI) {
 108         return 1;
 109     } else {
 110         return 0;
 111     }
 112 }
 113
 114 void
 115 ptyflush(void)
 116 {
 117         int n;
 118
 119         if ((n = pfrontp - pbackp) > 0) {
 120                 DIAG((TD_REPORT | TD_PTYDATA),
 121                         { output_data("td: ptyflush %d chars\r\n", n); });
 122                 DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
 123                 n = write(pty, pbackp, n);
 124         }
 125         if (n < 0) {
 126                 if (errno == EWOULDBLOCK || errno == EINTR)
 127                         return;
 128                 cleanup(0);
 129         }
 130         pbackp += n;
 131         if (pbackp == pfrontp)
 132                 pbackp = pfrontp = ptyobuf;
 133 }
 134
 135 /*
 136  * nextitem()
 137  *
 138  *      Return the address of the next "item" in the TELNET data
 139  * stream.  This will be the address of the next character if
 140  * the current address is a user data character, or it will
 141  * be the address of the character following the TELNET command
 142  * if the current address is a TELNET IAC ("I Am a Command")
 143  * character.
 144  */
 145 char *
 146 nextitem(char *current)
 147 {
 148     if ((*current&0xff) != IAC) {
 149         return current+1;
 150     }
 151     switch (*(current+1)&0xff) {
 152     case DO:
 153     case DONT:
 154     case WILL:
 155     case WONT:
 156         return current+3;
 157     case SB:            /* loop forever looking for the SE */
 158         {
 159             char *look = current+2;
 160
 161             for (;;) {
 162                 if ((*look++&0xff) == IAC) {
 163                     if ((*look++&0xff) == SE) {
 164                         return look;
 165                     }
 166                 }
 167             }
 168         }
 169     default:
 170         return current+2;
 171     }
 172 }  /* end of nextitem */
 173
 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
 249     if ((n = nfrontp - nbackp) > 0) {
 250         DIAG(TD_REPORT,
 251             { output_data("td: netflush %d chars\r\n", n);
 252               n = nfrontp - nbackp;     /* re-compute count */
 253             });
 254 #ifdef  ENCRYPTION
 255         if (encrypt_output) {
 256                 char *s = nclearto ? nclearto : nbackp;
 257                 if (nfrontp - s > 0) {
 258                         (*encrypt_output)((unsigned char *)s, nfrontp - s);
 259                         nclearto = nfrontp;
 260                 }
 261         }
 262 #endif  /* ENCRYPTION */
 263         /*
 264          * if no urgent data, or if the other side appears to be an
 265          * old 4.2 client (and thus unable to survive TCP urgent data),
 266          * write the entire buffer in non-OOB mode.
 267          */
 268         if ((neturg == 0) || (not42 == 0)) {
 269             n = write(net, nbackp, n);  /* normal write */
 270         } else {
 271             n = neturg - nbackp;
 272             /*
 273              * In 4.2 (and 4.3) systems, there is some question about
 274              * what byte in a sendOOB operation is the "OOB" data.
 275              * To make ourselves compatible, we only send ONE byte
 276              * out of band, the one WE THINK should be OOB (though
 277              * we really have more the TCP philosophy of urgent data
 278              * rather than the Unix philosophy of OOB data).
 279              */
 280             if (n > 1) {
 281                 n = send(net, nbackp, n-1, 0);  /* send URGENT all by itself */
 282             } else {
 283                 n = send(net, nbackp, n, MSG_OOB);      /* URGENT data */
 284             }
 285         }
 286     }
 287     if (n < 0) {
 288         if (errno == EWOULDBLOCK || errno == EINTR)
 289                 return;
 290         cleanup(0);
 291     }
 292     nbackp += n;
 293 #ifdef  ENCRYPTION
 294     if (nbackp > nclearto)
 295         nclearto = 0;
 296 #endif  /* ENCRYPTION */
 297     if (nbackp >= neturg) {
 298         neturg = 0;
 299     }
 300     if (nbackp == nfrontp) {
 301         nbackp = nfrontp = netobuf;
 302 #ifdef  ENCRYPTION
 303         nclearto = 0;
 304 #endif  /* ENCRYPTION */
 305     }
 306     return;
 307 }  /* end of netflush */
 308
 309
 310 /*
 311  * writenet
 312  *
 313  * Just a handy little function to write a bit of raw data to the net.
 314  * It will force a transmit of the buffer if necessary
 315  *
 316  * arguments
 317  *    ptr - A pointer to a character string to write
 318  *    len - How many bytes to write
 319  */
 320 void
 321 writenet(unsigned char *ptr, int len)
 322 {
 323         /* flush buffer if no room for new data) */
 324         if ((&netobuf[BUFSIZ] - nfrontp) < len) {
 325                 /* if this fails, don't worry, buffer is a little big */
 326                 netflush();
 327         }
 328
 329         memmove(nfrontp, ptr, len);
 330         nfrontp += len;
 331
 332 }  /* end of writenet */
 333
 334
 335 /*
 336  * miscellaneous functions doing a variety of little jobs follow ...
 337  */
 338 void
 339 fatal(int f, const char *msg)
 340 {
 341         char buf[BUFSIZ];
 342
 343         (void)snprintf(buf, sizeof buf, "telnetd: %s.\r\n", msg);
 344 #ifdef  ENCRYPTION
 345         if (encrypt_output) {
 346                 /*
 347                  * Better turn off encryption first....
 348                  * Hope it flushes...
 349                  */
 350                 encrypt_send_end();
 351                 netflush();
 352         }
 353 #endif  /* ENCRYPTION */
 354         (void)write(f, buf, (int)strlen(buf));
 355         sleep(1);       /*XXX*/
 356         exit(1);
 357 }
 358
 359 void
 360 fatalperror(f, msg)
 361         int f;
 362         const char *msg;
 363 {
 364         char buf[BUFSIZ];
 365
 366         (void)snprintf(buf, sizeof buf, "%s: %s", msg, strerror(errno));
 367         fatal(f, buf);
 368 }
 369
 370 char editedhost[MAXHOSTNAMELEN];
 371
 372 void
 373 edithost(char *pat, char *host)
 374 {
 375         char *res = editedhost;
 376
 377         if (!pat)
 378                 pat = "";
 379         while (*pat) {
 380                 switch (*pat) {
 381
 382                 case '#':
 383                         if (*host)
 384                                 host++;
 385                         break;
 386
 387                 case '@':
 388                         if (*host)
 389                                 *res++ = *host++;
 390                         break;
 391
 392                 default:
 393                         *res++ = *pat;
 394                         break;
 395                 }
 396                 if (res == &editedhost[sizeof editedhost - 1]) {
 397                         *res = '\0';
 398                         return;
 399                 }
 400                 pat++;
 401         }
 402         if (*host)
 403                 (void) strncpy(res, host,
 404                     sizeof editedhost - (res - editedhost) -1);
 405         else
 406                 *res = '\0';
 407         editedhost[sizeof editedhost - 1] = '\0';
 408 }
 409
 410 static char *putlocation;
 411
 412 void
 413 putstr(char *s)
 414 {
 415
 416         while (*s)
 417                 putchr(*s++);
 418 }
 419
 420 void
 421 putchr(int cc)
 422 {
 423         *putlocation++ = cc;
 424 }
 425
 426 /*
 427  * This is split on two lines so that SCCS will not see the M
 428  * between two % signs and expand it...
 429  */
 430 static char fmtstr[] = { "%l:%M\
 431 %p on %A, %d %B %Y" };
 432
 433 char *
 434 putf(char *cp, char *where)
 435 {
 436         char *slash;
 437         time_t t;
 438         char db[100];
 439         struct utsname utsinfo;
 440
 441         uname(&utsinfo);
 442
 443         putlocation = where;
 444
 445         while (*cp) {
 446                 if (*cp != '%') {
 447                         putchr(*cp++);
 448                         continue;
 449                 }
 450                 switch (*++cp) {
 451
 452                 case 't':
 453                         if ((slash = strstr(line, "/pts/")) == NULL)
 454                                 slash = strrchr(line, '/');
 455                         if (slash == (char *) 0)
 456                                 putstr(line);
 457                         else
 458                                 putstr(&slash[1]);
 459                         break;
 460
 461                 case 'h':
 462                         putstr(editedhost);
 463                         break;
 464
 465                 case 'd':
 466                         (void)time(&t);
 467                         (void)strftime(db, sizeof(db), fmtstr, localtime(&t));
 468                         putstr(db);
 469                         break;
 470
 471                 case '%':
 472                         putchr('%');
 473                         break;
 474
 475                 case 's':
 476                         putstr(utsinfo.sysname);
 477                         break;
 478
 479                 case 'm':
 480                         putstr(utsinfo.machine);
 481                         break;
 482
 483                 case 'r':
 484                         putstr(utsinfo.release);
 485                         break;
 486
 487                 case 'v':
 488                         putstr(utsinfo.version);
 489                         break;
 490                 }
 491                 cp++;
 492         }
 493
 494         return (putlocation);
 495 }
 496
 497 #ifdef DIAGNOSTICS
 498 /*
 499  * Print telnet options and commands in plain text, if possible.
 500  */
 501 void
 502 printoption(const char *fmt, int option)
 503 {
 504         if (TELOPT_OK(option))
 505                 output_data("%s %s\r\n", fmt, TELOPT(option));
 506         else if (TELCMD_OK(option))
 507                 output_data("%s %s\r\n", fmt, TELCMD(option));
 508         else
 509                 output_data("%s %d\r\n", fmt, option);
 510         return;
 511 }
 512
 513 void
 514 printsub(
 515     int    direction,   /* '<' or '>' */
 516     unsigned char *pointer,     /* where suboption data sits */
 517     int            length)      /* length of suboption data */
 518 {
 519     int i = 0;
 520 #if     defined(AUTHENTICATION) || defined(ENCRYPTION)
 521     u_char buf[512];
 522 #endif
 523
 524         if (!(diagnostic & TD_OPTIONS))
 525                 return;
 526
 527         if (direction) {
 528             output_data("td: %s suboption ",
 529                 direction == '<' ? "recv" : "send");
 530             if (length >= 3) {
 531                 int j;
 532
 533                 i = pointer[length - 2];
 534                 j = pointer[length - 1];
 535
 536                 if (i != IAC || j != SE) {
 537                     output_data("(terminated by ");
 538                     if (TELOPT_OK(i))
 539                         output_data("%s ", TELOPT(i));
 540                     else if (TELCMD_OK(i))
 541                         output_data("%s ", TELCMD(i));
 542                     else
 543                         output_data("%d ", i);
 544                     if (TELOPT_OK(j))
 545                         output_data("%s", TELOPT(j));
 546                     else if (TELCMD_OK(j))
 547                         output_data("%s", TELCMD(j));
 548                     else
 549                         output_data("%d", j);
 550                     output_data(", not IAC SE!) ");
 551                 }
 552             }
 553             length -= 2;
 554         }
 555         if (length < 1) {
 556             output_data("(Empty suboption??\?)");
 557             return;
 558         }
 559         switch (pointer[0]) {
 560         case TELOPT_TTYPE:
 561             output_data("TERMINAL-TYPE ");
 562             switch (pointer[1]) {
 563             case TELQUAL_IS:
 564                 output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
 565                 break;
 566             case TELQUAL_SEND:
 567                 output_data("SEND");
 568                 break;
 569             default:
 570                 output_data("- unknown qualifier %d (0x%x).",
 571                     pointer[1], pointer[1]);
 572             }
 573             break;
 574         case TELOPT_TSPEED:
 575             output_data("TERMINAL-SPEED");
 576             if (length < 2) {
 577                 output_data(" (empty suboption??\?)");
 578                 break;
 579             }
 580             switch (pointer[1]) {
 581             case TELQUAL_IS:
 582                 output_data(" IS %.*s", length-2, (char *)pointer+2);
 583                 break;
 584             default:
 585                 if (pointer[1] == 1)
 586                     output_data(" SEND");
 587                 else
 588                     output_data(" %d (unknown)", pointer[1]);
 589                 for (i = 2; i < length; i++) {
 590                     output_data(" ?%d?", pointer[i]);
 591                 }
 592                 break;
 593             }
 594             break;
 595
 596         case TELOPT_LFLOW:
 597             output_data("TOGGLE-FLOW-CONTROL");
 598             if (length < 2) {
 599                 output_data(" (empty suboption??\?)");
 600                 break;
 601             }
 602             switch (pointer[1]) {
 603             case LFLOW_OFF:
 604                 output_data(" OFF"); break;
 605             case LFLOW_ON:
 606                 output_data(" ON"); break;
 607             case LFLOW_RESTART_ANY:
 608                 output_data(" RESTART-ANY"); break;
 609             case LFLOW_RESTART_XON:
 610                 output_data(" RESTART-XON"); break;
 611             default:
 612                 output_data(" %d (unknown)", pointer[1]);
 613             }
 614             for (i = 2; i < length; i++)
 615                 output_data(" ?%d?", pointer[i]);
 616             break;
 617
 618         case TELOPT_NAWS:
 619             output_data("NAWS");
 620             if (length < 2) {
 621                 output_data(" (empty suboption??\?)");
 622                 break;
 623             }
 624             if (length == 2) {
 625                 output_data(" ?%d?", pointer[1]);
 626                 break;
 627             }
 628             output_data(" %d %d (%d)",
 629                 pointer[1], pointer[2],
 630                 (int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
 631             if (length == 4) {
 632                 output_data(" ?%d?", pointer[3]);
 633                 break;
 634             }
 635             output_data(" %d %d (%d)", pointer[3], pointer[4],
 636                 (int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
 637             for (i = 5; i < length; i++) {
 638                 output_data(" ?%d?", pointer[i]);
 639             }
 640             break;
 641
 642         case TELOPT_LINEMODE:
 643             output_data("LINEMODE ");
 644             if (length < 2) {
 645                 output_data(" (empty suboption??\?)");
 646                 break;
 647             }
 648             switch (pointer[1]) {
 649             case WILL:
 650                 output_data("WILL ");
 651                 goto common;
 652             case WONT:
 653                 output_data("WONT ");
 654                 goto common;
 655             case DO:
 656                 output_data("DO ");
 657                 goto common;
 658             case DONT:
 659                 output_data("DONT ");
 660             common:
 661                 if (length < 3) {
 662                     output_data("(no option??\?)");
 663                     break;
 664                 }
 665                 switch (pointer[2]) {
 666                 case LM_FORWARDMASK:
 667                     output_data("Forward Mask");
 668                     for (i = 3; i < length; i++)
 669                         output_data(" %x", pointer[i]);
 670                     break;
 671                 default:
 672                     output_data("%d (unknown)", pointer[2]);
 673                     for (i = 3; i < length; i++)
 674                         output_data(" %d", pointer[i]);
 675                     break;
 676                 }
 677                 break;
 678
 679             case LM_SLC:
 680                 output_data("SLC");
 681                 for (i = 2; i < length - 2; i += 3) {
 682                     if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
 683                         output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
 684                     else
 685                         output_data(" %d", pointer[i+SLC_FUNC]);
 686                     switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
 687                     case SLC_NOSUPPORT:
 688                         output_data(" NOSUPPORT"); break;
 689                     case SLC_CANTCHANGE:
 690                         output_data(" CANTCHANGE"); break;
 691                     case SLC_VARIABLE:
 692                         output_data(" VARIABLE"); break;
 693                     case SLC_DEFAULT:
 694                         output_data(" DEFAULT"); break;
 695                     }
 696                     output_data("%s%s%s",
 697                         pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
 698                         pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
 699                         pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
 700                     if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
 701                                                 SLC_FLUSHOUT| SLC_LEVELBITS)) {
 702                         output_data("(0x%x)", pointer[i+SLC_FLAGS]);
 703                     }
 704                     output_data(" %d;", pointer[i+SLC_VALUE]);
 705                     if ((pointer[i+SLC_VALUE] == IAC) &&
 706                         (pointer[i+SLC_VALUE+1] == IAC))
 707                                 i++;
 708                 }
 709                 for (; i < length; i++)
 710                     output_data(" ?%d?", pointer[i]);
 711                 break;
 712
 713             case LM_MODE:
 714                 output_data("MODE ");
 715                 if (length < 3) {
 716                     output_data("(no mode??\?)");
 717                     break;
 718                 }
 719                 {
 720                     char tbuf[32];
 721
 722                     (void)snprintf(tbuf, sizeof tbuf, "%s%s%s%s%s",
 723                         pointer[2]&MODE_EDIT ? "|EDIT" : "",
 724                         pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
 725                         pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
 726                         pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
 727                         pointer[2]&MODE_ACK ? "|ACK" : "");
 728                     output_data("%s", tbuf[1] ? &tbuf[1] : "0");
 729                 }
 730                 if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK))
 731                     output_data(" (0x%x)", pointer[2]);
 732                 for (i = 3; i < length; i++)
 733                     output_data(" ?0x%x?", pointer[i]);
 734                 break;
 735             default:
 736                 output_data("%d (unknown)", pointer[1]);
 737                 for (i = 2; i < length; i++)
 738                     output_data(" %d", pointer[i]);
 739             }
 740             break;
 741
 742         case TELOPT_STATUS: {
 743             char *cp;
 744             int j, k;
 745
 746             output_data("STATUS");
 747
 748             switch (pointer[1]) {
 749             default:
 750                 if (pointer[1] == TELQUAL_SEND)
 751                     output_data(" SEND");
 752                 else
 753                     output_data(" %d (unknown)", pointer[1]);
 754                 for (i = 2; i < length; i++)
 755                     output_data(" ?%d?", pointer[i]);
 756                 break;
 757             case TELQUAL_IS:
 758                 output_data(" IS\r\n");
 759
 760                 for (i = 2; i < length; i++) {
 761                     switch(pointer[i]) {
 762                     case DO:    cp = "DO"; goto common2;
 763                     case DONT:  cp = "DONT"; goto common2;
 764                     case WILL:  cp = "WILL"; goto common2;
 765                     case WONT:  cp = "WONT"; goto common2;
 766                     common2:
 767                         i++;
 768                         if (TELOPT_OK(pointer[i]))
 769                             output_data(" %s %s", cp, TELOPT(pointer[i]));
 770                         else
 771                             output_data(" %s %d", cp, pointer[i]);
 772
 773                         output_data("\r\n");
 774                         break;
 775
 776                     case SB:
 777                         output_data(" SB ");
 778                         i++;
 779                         j = k = i;
 780                         while (j < length) {
 781                             if (pointer[j] == SE) {
 782                                 if (j+1 == length)
 783                                     break;
 784                                 if (pointer[j+1] == SE)
 785                                     j++;
 786                                 else
 787                                     break;
 788                             }
 789                             pointer[k++] = pointer[j++];
 790                         }
 791                         printsub(0, &pointer[i], k - i);
 792                         if (i < length) {
 793                             output_data(" SE");
 794                             i = j;
 795                         } else
 796                             i = j - 1;
 797
 798                         output_data("\r\n");
 799
 800                         break;
 801
 802                     default:
 803                         output_data(" %d", pointer[i]);
 804                         break;
 805                     }
 806                 }
 807                 break;
 808             }
 809             break;
 810           }
 811
 812         case TELOPT_XDISPLOC:
 813             output_data("X-DISPLAY-LOCATION ");
 814             switch (pointer[1]) {
 815             case TELQUAL_IS:
 816                 output_data("IS \"%.*s\"", length - 2, (char *)pointer + 2);
 817                 break;
 818             case TELQUAL_SEND:
 819                 output_data("SEND");
 820                 break;
 821             default:
 822                 output_data("- unknown qualifier %d (0x%x).",
 823                     pointer[1], pointer[1]);
 824             }
 825             break;
 826
 827         case TELOPT_NEW_ENVIRON:
 828             output_data("NEW-ENVIRON ");
 829             goto env_common1;
 830         case TELOPT_OLD_ENVIRON:
 831             output_data("OLD-ENVIRON");
 832         env_common1:
 833             switch (pointer[1]) {
 834             case TELQUAL_IS:
 835                 output_data("IS ");
 836                 goto env_common;
 837             case TELQUAL_SEND:
 838                 output_data("SEND ");
 839                 goto env_common;
 840             case TELQUAL_INFO:
 841                 output_data("INFO ");
 842             env_common:
 843                 {
 844                     int noquote = 2;
 845                     for (i = 2; i < length; i++ ) {
 846                         switch (pointer[i]) {
 847                         case NEW_ENV_VAR:
 848                             output_data("%s", "\" VAR " + noquote);
 849                             noquote = 2;
 850                             break;
 851
 852                         case NEW_ENV_VALUE:
 853                             output_data("%s", "\" VALUE " + noquote);
 854                             noquote = 2;
 855                             break;
 856
 857                         case ENV_ESC:
 858                             output_data("%s", "\" ESC " + noquote);
 859                             noquote = 2;
 860                             break;
 861
 862                         case ENV_USERVAR:
 863                             output_data("%s", "\" USERVAR " + noquote);
 864                             noquote = 2;
 865                             break;
 866
 867                         default:
 868                             if (isprint(pointer[i]) && pointer[i] != '"') {
 869                                 if (noquote) {
 870                                     output_data("\"");
 871                                     noquote = 0;
 872                                 }
 873                                 output_data("%c", pointer[i]);
 874                             } else {
 875                                 output_data("\" %03o " + noquote, pointer[i]);
 876                                 noquote = 2;
 877                             }
 878                             break;
 879                         }
 880                     }
 881                     if (!noquote)
 882                         output_data("\"");
 883                     break;
 884                 }
 885             }
 886             break;
 887
 888 #ifdef AUTHENTICATION
 889         case TELOPT_AUTHENTICATION:
 890             output_data("AUTHENTICATION");
 891
 892             if (length < 2) {
 893                 output_data(" (empty suboption??\?)");
 894                 break;
 895             }
 896             switch (pointer[1]) {
 897             case TELQUAL_REPLY:
 898             case TELQUAL_IS:
 899                 output_data(" %s ", (pointer[1] == TELQUAL_IS) ?
 900                     "IS" : "REPLY");
 901                 if (AUTHTYPE_NAME_OK(pointer[2]))
 902                     output_data("%s ", AUTHTYPE_NAME(pointer[2]));
 903                 else
 904                     output_data("%d ", pointer[2]);
 905                 if (length < 3) {
 906                     output_data("(partial suboption??\?)");
 907                     break;
 908                 }
 909                 output_data("%s|%s",
 910                         ((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
 911                         "CLIENT" : "SERVER",
 912                         ((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
 913                         "MUTUAL" : "ONE-WAY");
 914
 915                 auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
 916                 output_data("%s", buf);
 917                 break;
 918
 919             case TELQUAL_SEND:
 920                 i = 2;
 921                 output_data(" SEND ");
 922                 while (i < length) {
 923                     if (AUTHTYPE_NAME_OK(pointer[i]))
 924                         output_data("%s ", AUTHTYPE_NAME(pointer[i]));
 925                     else
 926                         output_data("%d ", pointer[i]);
 927                     if (++i >= length) {
 928                         output_data("(partial suboption??\?)");
 929                         break;
 930                     }
 931                     output_data("%s|%s ",
 932                         ((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
 933                                                         "CLIENT" : "SERVER",
 934                         ((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
 935                                                         "MUTUAL" : "ONE-WAY");
 936                     ++i;
 937                 }
 938                 break;
 939
 940             case TELQUAL_NAME:
 941                 i = 2;
 942                 output_data(" NAME \"");
 943                 while (i < length) {
 944                     if (isprint(pointer[i]))
 945                         output_data("%c", pointer[i++]);
 946                     else
 947                         output_data("\"%03o\"",pointer[i++]);
 948                 }
 949                 output_data("\"");
 950                 break;
 951
 952             default:
 953                 for (i = 2; i < length; i++)
 954                     output_data(" ?%d?", pointer[i]);
 955                 break;
 956             }
 957             break;
 958 #endif
 959
 960 #ifdef  ENCRYPTION
 961         case TELOPT_ENCRYPT:
 962             output_data("ENCRYPT");
 963             if (length < 2) {
 964                 output_data(" (empty suboption??\?)");
 965                 break;
 966             }
 967             switch (pointer[1]) {
 968             case ENCRYPT_START:
 969                 output_data(" START");
 970                 break;
 971
 972             case ENCRYPT_END:
 973                 output_data(" END");
 974                 break;
 975
 976             case ENCRYPT_REQSTART:
 977                 output_data(" REQUEST-START");
 978                 break;
 979
 980             case ENCRYPT_REQEND:
 981                 output_data(" REQUEST-END");
 982                 break;
 983
 984             case ENCRYPT_IS:
 985             case ENCRYPT_REPLY:
 986                 output_data(" %s ", (pointer[1] == ENCRYPT_IS) ?
 987                     "IS" : "REPLY");
 988                 if (length < 3) {
 989                         output_data(" (partial suboption??\?)");
 990                         break;
 991                 }
 992                 if (ENCTYPE_NAME_OK(pointer[2]))
 993                         output_data("%s ", ENCTYPE_NAME(pointer[2]));
 994                 else
 995                         output_data(" %d (unknown)", pointer[2]);
 996
 997                 encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
 998                 output_data("%s", buf);
 999                 break;
1000
1001             case ENCRYPT_SUPPORT:
1002                 i = 2;
1003                 output_data(" SUPPORT ");
1004                 while (i < length) {
1005                         if (ENCTYPE_NAME_OK(pointer[i]))
1006                                 output_data("%s ", ENCTYPE_NAME(pointer[i]));
1007                         else
1008                                 output_data("%d ", pointer[i]);
1009                         i++;
1010                 }
1011                 break;
1012
1013             case ENCRYPT_ENC_KEYID:
1014                 output_data(" ENC_KEYID");
1015                 goto encommon;
1016
1017             case ENCRYPT_DEC_KEYID:
1018                 output_data(" DEC_KEYID");
1019                 goto encommon;
1020
1021             default:
1022                 output_data(" %d (unknown)", pointer[1]);
1023             encommon:
1024                 for (i = 2; i < length; i++)
1025                         output_data(" %d", pointer[i]);
1026                 break;
1027             }
1028             break;
1029 #endif  /* ENCRYPTION */
1030
1031         default:
1032             if (TELOPT_OK(pointer[0]))
1033                 output_data("%s (unknown)", TELOPT(pointer[0]));
1034             else
1035                 output_data("%d (unknown)", pointer[i]);
1036             for (i = 1; i < length; i++)
1037                 output_data(" %d", pointer[i]);
1038             break;
1039         }
1040         output_data("\r\n");
1041 }
1042
1043 /*
1044  * Dump a data buffer in hex and ascii to the output data stream.
1045  */
1046 void
1047 printdata(char *tag, char *ptr, int cnt)
1048 {
1049         int i;
1050         char xbuf[30];
1051
1052         while (cnt) {
1053                 /* flush net output buffer if no room for new data) */
1054                 if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
1055                         netflush();
1056                 }
1057
1058                 /* add a line of output */
1059                 output_data("%s: ", tag);
1060                 for (i = 0; i < 20 && cnt; i++) {
1061                         output_data("%02x", *ptr);
1062                         if (isprint((unsigned char)*ptr)) {
1063                                 xbuf[i] = *ptr;
1064                         } else {
1065                                 xbuf[i] = '.';
1066                         }
1067                         if (i % 2)
1068                                 output_data(" ");
1069                         cnt--;
1070                         ptr++;
1071                 }
1072                 xbuf[i] = '\0';
1073                 output_data(" %s\r\n", xbuf);
1074         }
1075 }
1076 #endif /* DIAGNOSTICS */