contrib/tcpdump/print-telnet.c

   1 /*      $NetBSD: print-telnet.c,v 1.2 1999/10/11 12:40:12 sjg Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Simon J. Gerraty.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *        This product includes software developed by the NetBSD
  21  *        Foundation, Inc. and its contributors.
  22  * 4. Neither the name of The NetBSD Foundation nor the names of its
  23  *    contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36  * POSSIBILITY OF SUCH DAMAGE.
  37  */
  38 /*
  39  *      @(#)Copyright (c) 1994, Simon J. Gerraty.
  40  *
  41  *      This is free software.  It comes with NO WARRANTY.
  42  *      Permission to use, modify and distribute this source code
  43  *      is granted subject to the following conditions.
  44  *      1/ that the above copyright notice and this notice
  45  *      are preserved in all copies.
  46  */
  47
  48 /* \summary: Telnet option printer */
  49
  50 #ifdef HAVE_CONFIG_H
  51 #include "config.h"
  52 #endif
  53
  54 #include <netdissect-stdinc.h>
  55
  56 #include <stdio.h>
  57
  58 #include "netdissect.h"
  59
  60 static const char tstr[] = " [|telnet]";
  61
  62 #define TELCMDS
  63 #define TELOPTS
  64
  65 /*      NetBSD: telnet.h,v 1.9 2001/06/11 01:50:50 wiz Exp      */
  66
  67 /*
  68  * Definitions for the TELNET protocol.
  69  */
  70 #define IAC     255             /* interpret as command: */
  71 #define DONT    254             /* you are not to use option */
  72 #define DO      253             /* please, you use option */
  73 #define WONT    252             /* I won't use option */
  74 #define WILL    251             /* I will use option */
  75 #define SB      250             /* interpret as subnegotiation */
  76 #define GA      249             /* you may reverse the line */
  77 #define EL      248             /* erase the current line */
  78 #define EC      247             /* erase the current character */
  79 #define AYT     246             /* are you there */
  80 #define AO      245             /* abort output--but let prog finish */
  81 #define IP      244             /* interrupt process--permanently */
  82 #define BREAK   243             /* break */
  83 #define DM      242             /* data mark--for connect. cleaning */
  84 #define NOP     241             /* nop */
  85 #define SE      240             /* end sub negotiation */
  86 #define EOR     239             /* end of record (transparent mode) */
  87 #define ABORT   238             /* Abort process */
  88 #define SUSP    237             /* Suspend process */
  89 #define xEOF    236             /* End of file: EOF is already used... */
  90
  91 #define SYNCH   242             /* for telfunc calls */
  92
  93 #ifdef TELCMDS
  94 static const char *telcmds[] = {
  95         "EOF", "SUSP", "ABORT", "EOR",
  96         "SE", "NOP", "DMARK", "BRK", "IP", "AO", "AYT", "EC",
  97         "EL", "GA", "SB", "WILL", "WONT", "DO", "DONT", "IAC", 0,
  98 };
  99 #else
 100 extern char *telcmds[];
 101 #endif
 102
 103 #define TELCMD_FIRST    xEOF
 104 #define TELCMD_LAST     IAC
 105 #define TELCMD_OK(x)    ((unsigned int)(x) <= TELCMD_LAST && \
 106                          (unsigned int)(x) >= TELCMD_FIRST)
 107 #define TELCMD(x)       telcmds[(x)-TELCMD_FIRST]
 108
 109 /* telnet options */
 110 #define TELOPT_BINARY   0       /* 8-bit data path */
 111 #define TELOPT_ECHO     1       /* echo */
 112 #define TELOPT_RCP      2       /* prepare to reconnect */
 113 #define TELOPT_SGA      3       /* suppress go ahead */
 114 #define TELOPT_NAMS     4       /* approximate message size */
 115 #define TELOPT_STATUS   5       /* give status */
 116 #define TELOPT_TM       6       /* timing mark */
 117 #define TELOPT_RCTE     7       /* remote controlled transmission and echo */
 118 #define TELOPT_NAOL     8       /* negotiate about output line width */
 119 #define TELOPT_NAOP     9       /* negotiate about output page size */
 120 #define TELOPT_NAOCRD   10      /* negotiate about CR disposition */
 121 #define TELOPT_NAOHTS   11      /* negotiate about horizontal tabstops */
 122 #define TELOPT_NAOHTD   12      /* negotiate about horizontal tab disposition */
 123 #define TELOPT_NAOFFD   13      /* negotiate about formfeed disposition */
 124 #define TELOPT_NAOVTS   14      /* negotiate about vertical tab stops */
 125 #define TELOPT_NAOVTD   15      /* negotiate about vertical tab disposition */
 126 #define TELOPT_NAOLFD   16      /* negotiate about output LF disposition */
 127 #define TELOPT_XASCII   17      /* extended ascic character set */
 128 #define TELOPT_LOGOUT   18      /* force logout */
 129 #define TELOPT_BM       19      /* byte macro */
 130 #define TELOPT_DET      20      /* data entry terminal */
 131 #define TELOPT_SUPDUP   21      /* supdup protocol */
 132 #define TELOPT_SUPDUPOUTPUT 22  /* supdup output */
 133 #define TELOPT_SNDLOC   23      /* send location */
 134 #define TELOPT_TTYPE    24      /* terminal type */
 135 #define TELOPT_EOR      25      /* end or record */
 136 #define TELOPT_TUID     26      /* TACACS user identification */
 137 #define TELOPT_OUTMRK   27      /* output marking */
 138 #define TELOPT_TTYLOC   28      /* terminal location number */
 139 #define TELOPT_3270REGIME 29    /* 3270 regime */
 140 #define TELOPT_X3PAD    30      /* X.3 PAD */
 141 #define TELOPT_NAWS     31      /* window size */
 142 #define TELOPT_TSPEED   32      /* terminal speed */
 143 #define TELOPT_LFLOW    33      /* remote flow control */
 144 #define TELOPT_LINEMODE 34      /* Linemode option */
 145 #define TELOPT_XDISPLOC 35      /* X Display Location */
 146 #define TELOPT_OLD_ENVIRON 36   /* Old - Environment variables */
 147 #define TELOPT_AUTHENTICATION 37/* Authenticate */
 148 #define TELOPT_ENCRYPT  38      /* Encryption option */
 149 #define TELOPT_NEW_ENVIRON 39   /* New - Environment variables */
 150 #define TELOPT_EXOPL    255     /* extended-options-list */
 151
 152
 153 #define NTELOPTS        (1+TELOPT_NEW_ENVIRON)
 154 #ifdef TELOPTS
 155 static const char *telopts[NTELOPTS+1] = {
 156         "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME",
 157         "STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP",
 158         "NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS",
 159         "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT", "BYTE MACRO",
 160         "DATA ENTRY TERMINAL", "SUPDUP", "SUPDUP OUTPUT",
 161         "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD",
 162         "TACACS UID", "OUTPUT MARKING", "TTYLOC",
 163         "3270 REGIME", "X.3 PAD", "NAWS", "TSPEED", "LFLOW",
 164         "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION",
 165         "ENCRYPT", "NEW-ENVIRON",
 166         0,
 167 };
 168 #define TELOPT_FIRST    TELOPT_BINARY
 169 #define TELOPT_LAST     TELOPT_NEW_ENVIRON
 170 #define TELOPT_OK(x)    ((unsigned int)(x) <= TELOPT_LAST)
 171 #define TELOPT(x)       telopts[(x)-TELOPT_FIRST]
 172 #endif
 173
 174 /* sub-option qualifiers */
 175 #define TELQUAL_IS      0       /* option is... */
 176 #define TELQUAL_SEND    1       /* send option */
 177 #define TELQUAL_INFO    2       /* ENVIRON: informational version of IS */
 178 #define TELQUAL_REPLY   2       /* AUTHENTICATION: client version of IS */
 179 #define TELQUAL_NAME    3       /* AUTHENTICATION: client version of IS */
 180
 181 #define LFLOW_OFF               0       /* Disable remote flow control */
 182 #define LFLOW_ON                1       /* Enable remote flow control */
 183 #define LFLOW_RESTART_ANY       2       /* Restart output on any char */
 184 #define LFLOW_RESTART_XON       3       /* Restart output only on XON */
 185
 186 /*
 187  * LINEMODE suboptions
 188  */
 189
 190 #define LM_MODE         1
 191 #define LM_FORWARDMASK  2
 192 #define LM_SLC          3
 193
 194 #define MODE_EDIT       0x01
 195 #define MODE_TRAPSIG    0x02
 196 #define MODE_ACK        0x04
 197 #define MODE_SOFT_TAB   0x08
 198 #define MODE_LIT_ECHO   0x10
 199
 200 #define MODE_MASK       0x1f
 201
 202 #define SLC_SYNCH       1
 203 #define SLC_BRK         2
 204 #define SLC_IP          3
 205 #define SLC_AO          4
 206 #define SLC_AYT         5
 207 #define SLC_EOR         6
 208 #define SLC_ABORT       7
 209 #define SLC_EOF         8
 210 #define SLC_SUSP        9
 211 #define SLC_EC          10
 212 #define SLC_EL          11
 213 #define SLC_EW          12
 214 #define SLC_RP          13
 215 #define SLC_LNEXT       14
 216 #define SLC_XON         15
 217 #define SLC_XOFF        16
 218 #define SLC_FORW1       17
 219 #define SLC_FORW2       18
 220 #define SLC_MCL         19
 221 #define SLC_MCR         20
 222 #define SLC_MCWL        21
 223 #define SLC_MCWR        22
 224 #define SLC_MCBOL       23
 225 #define SLC_MCEOL       24
 226 #define SLC_INSRT       25
 227 #define SLC_OVER        26
 228 #define SLC_ECR         27
 229 #define SLC_EWR         28
 230 #define SLC_EBOL        29
 231 #define SLC_EEOL        30
 232
 233 #define NSLC            30
 234
 235 /*
 236  * For backwards compatibility, we define SLC_NAMES to be the
 237  * list of names if SLC_NAMES is not defined.
 238  */
 239 #define SLC_NAMELIST    "0", "SYNCH", "BRK", "IP", "AO", "AYT", "EOR",  \
 240                         "ABORT", "EOF", "SUSP", "EC", "EL", "EW", "RP", \
 241                         "LNEXT", "XON", "XOFF", "FORW1", "FORW2",       \
 242                         "MCL", "MCR", "MCWL", "MCWR", "MCBOL",          \
 243                         "MCEOL", "INSRT", "OVER", "ECR", "EWR",         \
 244                         "EBOL", "EEOL",                                 \
 245                         0,
 246
 247 #ifdef  SLC_NAMES
 248 const char *slc_names[] = {
 249         SLC_NAMELIST
 250 };
 251 #else
 252 extern char *slc_names[];
 253 #define SLC_NAMES SLC_NAMELIST
 254 #endif
 255
 256 #define SLC_NAME_OK(x)  ((unsigned int)(x) <= NSLC)
 257 #define SLC_NAME(x)     slc_names[x]
 258
 259 #define SLC_NOSUPPORT   0
 260 #define SLC_CANTCHANGE  1
 261 #define SLC_VARIABLE    2
 262 #define SLC_DEFAULT     3
 263 #define SLC_LEVELBITS   0x03
 264
 265 #define SLC_FUNC        0
 266 #define SLC_FLAGS       1
 267 #define SLC_VALUE       2
 268
 269 #define SLC_ACK         0x80
 270 #define SLC_FLUSHIN     0x40
 271 #define SLC_FLUSHOUT    0x20
 272
 273 #define OLD_ENV_VAR     1
 274 #define OLD_ENV_VALUE   0
 275 #define NEW_ENV_VAR     0
 276 #define NEW_ENV_VALUE   1
 277 #define ENV_ESC         2
 278 #define ENV_USERVAR     3
 279
 280 /*
 281  * AUTHENTICATION suboptions
 282  */
 283
 284 /*
 285  * Who is authenticating who ...
 286  */
 287 #define AUTH_WHO_CLIENT         0       /* Client authenticating server */
 288 #define AUTH_WHO_SERVER         1       /* Server authenticating client */
 289 #define AUTH_WHO_MASK           1
 290
 291 #define AUTHTYPE_NULL           0
 292 #define AUTHTYPE_KERBEROS_V4    1
 293 #define AUTHTYPE_KERBEROS_V5    2
 294 #define AUTHTYPE_SPX            3
 295 #define AUTHTYPE_MINK           4
 296 #define AUTHTYPE_CNT            5
 297
 298 #define AUTHTYPE_TEST           99
 299
 300 #ifdef  AUTH_NAMES
 301 const char *authtype_names[] = {
 302         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 0,
 303 };
 304 #else
 305 extern char *authtype_names[];
 306 #endif
 307
 308 #define AUTHTYPE_NAME_OK(x)     ((unsigned int)(x) < AUTHTYPE_CNT)
 309 #define AUTHTYPE_NAME(x)        authtype_names[x]
 310
 311 /*
 312  * ENCRYPTion suboptions
 313  */
 314 #define ENCRYPT_IS              0       /* I pick encryption type ... */
 315 #define ENCRYPT_SUPPORT         1       /* I support encryption types ... */
 316 #define ENCRYPT_REPLY           2       /* Initial setup response */
 317 #define ENCRYPT_START           3       /* Am starting to send encrypted */
 318 #define ENCRYPT_END             4       /* Am ending encrypted */
 319 #define ENCRYPT_REQSTART        5       /* Request you start encrypting */
 320 #define ENCRYPT_REQEND          6       /* Request you send encrypting */
 321 #define ENCRYPT_ENC_KEYID       7
 322 #define ENCRYPT_DEC_KEYID       8
 323 #define ENCRYPT_CNT             9
 324
 325 #define ENCTYPE_ANY             0
 326 #define ENCTYPE_DES_CFB64       1
 327 #define ENCTYPE_DES_OFB64       2
 328 #define ENCTYPE_CNT             3
 329
 330 #ifdef  ENCRYPT_NAMES
 331 const char *encrypt_names[] = {
 332         "IS", "SUPPORT", "REPLY", "START", "END",
 333         "REQUEST-START", "REQUEST-END", "ENC-KEYID", "DEC-KEYID",
 334         0,
 335 };
 336 const char *enctype_names[] = {
 337         "ANY", "DES_CFB64",  "DES_OFB64",  0,
 338 };
 339 #else
 340 extern char *encrypt_names[];
 341 extern char *enctype_names[];
 342 #endif
 343
 344 #define ENCRYPT_NAME_OK(x)      ((unsigned int)(x) < ENCRYPT_CNT)
 345 #define ENCRYPT_NAME(x)         encrypt_names[x]
 346
 347 #define ENCTYPE_NAME_OK(x)      ((unsigned int)(x) < ENCTYPE_CNT)
 348 #define ENCTYPE_NAME(x)         enctype_names[x]
 349
 350 /* normal */
 351 static const char *cmds[] = {
 352         "IS", "SEND", "INFO",
 353 };
 354
 355 /* 37: Authentication */
 356 static const char *authcmd[] = {
 357         "IS", "SEND", "REPLY", "NAME",
 358 };
 359 static const char *authtype[] = {
 360         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
 361         "SRP", "RSA", "SSL", NULL, NULL,
 362         "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
 363         "NTLM",
 364 };
 365
 366 /* 38: Encryption */
 367 static const char *enccmd[] = {
 368         "IS", "SUPPORT", "REPLY", "START", "END",
 369         "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
 370 };
 371 static const char *enctype[] = {
 372         "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
 373         NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
 374 };
 375
 376 #define STR_OR_ID(x, tab) \
 377         (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))
 378
 379 static char *
 380 numstr(int x)
 381 {
 382         static char buf[20];
 383
 384         snprintf(buf, sizeof(buf), "%#x", x);
 385         return buf;
 386 }
 387
 388 /* sp points to IAC byte */
 389 static int
 390 telnet_parse(netdissect_options *ndo, const u_char *sp, u_int length, int print)
 391 {
 392         int i, x;
 393         u_int c;
 394         const u_char *osp, *p;
 395 #define FETCH(c, sp, length) \
 396         do { \
 397                 if (length < 1) \
 398                         goto pktend; \
 399                 ND_TCHECK(*sp); \
 400                 c = *sp++; \
 401                 length--; \
 402         } while (0)
 403
 404         osp = sp;
 405
 406         FETCH(c, sp, length);
 407         if (c != IAC)
 408                 goto pktend;
 409         FETCH(c, sp, length);
 410         if (c == IAC) {         /* <IAC><IAC>! */
 411                 if (print)
 412                         ND_PRINT((ndo, "IAC IAC"));
 413                 goto done;
 414         }
 415
 416         i = c - TELCMD_FIRST;
 417         if (i < 0 || i > IAC - TELCMD_FIRST)
 418                 goto pktend;
 419
 420         switch (c) {
 421         case DONT:
 422         case DO:
 423         case WONT:
 424         case WILL:
 425         case SB:
 426                 /* DONT/DO/WONT/WILL x */
 427                 FETCH(x, sp, length);
 428                 if (x >= 0 && x < NTELOPTS) {
 429                         if (print)
 430                                 ND_PRINT((ndo, "%s %s", telcmds[i], telopts[x]));
 431                 } else {
 432                         if (print)
 433                                 ND_PRINT((ndo, "%s %#x", telcmds[i], x));
 434                 }
 435                 if (c != SB)
 436                         break;
 437                 /* IAC SB .... IAC SE */
 438                 p = sp;
 439                 while (length > (u_int)(p + 1 - sp)) {
 440                         ND_TCHECK2(*p, 2);
 441                         if (p[0] == IAC && p[1] == SE)
 442                                 break;
 443                         p++;
 444                 }
 445                 ND_TCHECK(*p);
 446                 if (*p != IAC)
 447                         goto pktend;
 448
 449                 switch (x) {
 450                 case TELOPT_AUTHENTICATION:
 451                         if (p <= sp)
 452                                 break;
 453                         FETCH(c, sp, length);
 454                         if (print)
 455                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, authcmd)));
 456                         if (p <= sp)
 457                                 break;
 458                         FETCH(c, sp, length);
 459                         if (print)
 460                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, authtype)));
 461                         break;
 462                 case TELOPT_ENCRYPT:
 463                         if (p <= sp)
 464                                 break;
 465                         FETCH(c, sp, length);
 466                         if (print)
 467                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, enccmd)));
 468                         if (p <= sp)
 469                                 break;
 470                         FETCH(c, sp, length);
 471                         if (print)
 472                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, enctype)));
 473                         break;
 474                 default:
 475                         if (p <= sp)
 476                                 break;
 477                         FETCH(c, sp, length);
 478                         if (print)
 479                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, cmds)));
 480                         break;
 481                 }
 482                 while (p > sp) {
 483                         FETCH(x, sp, length);
 484                         if (print)
 485                                 ND_PRINT((ndo, " %#x", x));
 486                 }
 487                 /* terminating IAC SE */
 488                 if (print)
 489                         ND_PRINT((ndo, " SE"));
 490                 sp += 2;
 491                 break;
 492         default:
 493                 if (print)
 494                         ND_PRINT((ndo, "%s", telcmds[i]));
 495                 goto done;
 496         }
 497
 498 done:
 499         return sp - osp;
 500
 501 trunc:
 502         ND_PRINT((ndo, "%s", tstr));
 503 pktend:
 504         return -1;
 505 #undef FETCH
 506 }
 507
 508 void
 509 telnet_print(netdissect_options *ndo, const u_char *sp, u_int length)
 510 {
 511         int first = 1;
 512         const u_char *osp;
 513         int l;
 514
 515         osp = sp;
 516
 517         ND_TCHECK(*sp);
 518         while (length > 0 && *sp == IAC) {
 519                 /*
 520                  * Parse the Telnet command without printing it,
 521                  * to determine its length.
 522                  */
 523                 l = telnet_parse(ndo, sp, length, 0);
 524                 if (l < 0)
 525                         break;
 526
 527                 /*
 528                  * now print it
 529                  */
 530                 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) {
 531                         if (first)
 532                                 ND_PRINT((ndo, "\nTelnet:"));
 533                         hex_print_with_offset(ndo, "\n", sp, l, sp - osp);
 534                         if (l > 8)
 535                                 ND_PRINT((ndo, "\n\t\t\t\t"));
 536                         else
 537                                 ND_PRINT((ndo, "%*s\t", (8 - l) * 3, ""));
 538                 } else
 539                         ND_PRINT((ndo, "%s", (first) ? " [telnet " : ", "));
 540
 541                 (void)telnet_parse(ndo, sp, length, 1);
 542                 first = 0;
 543
 544                 sp += l;
 545                 length -= l;
 546                 ND_TCHECK(*sp);
 547         }
 548         if (!first) {
 549                 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag)
 550                         ND_PRINT((ndo, "\n"));
 551                 else
 552                         ND_PRINT((ndo, "]"));
 553         }
 554         return;
 555 trunc:
 556         ND_PRINT((ndo, "%s", tstr));
 557 }