external/bsd/tcpdump/dist/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  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 /*
  32  *      @(#)Copyright (c) 1994, Simon J. Gerraty.
  33  *
  34  *      This is free software.  It comes with NO WARRANTY.
  35  *      Permission to use, modify and distribute this source code
  36  *      is granted subject to the following conditions.
  37  *      1/ that the above copyright notice and this notice
  38  *      are preserved in all copies.
  39  */
  40
  41 #include <sys/cdefs.h>
  42 #ifndef lint
  43 __RCSID("$NetBSD: print-telnet.c,v 1.5 2015/03/31 21:59:35 christos Exp $");
  44 #endif
  45
  46 #define NETDISSECT_REWORKED
  47 #ifdef HAVE_CONFIG_H
  48 #include "config.h"
  49 #endif
  50
  51 #include <tcpdump-stdinc.h>
  52
  53 #include <stdio.h>
  54
  55 #include "interface.h"
  56
  57 #define TELCMDS
  58 #define TELOPTS
  59
  60 /*      NetBSD: telnet.h,v 1.9 2001/06/11 01:50:50 wiz Exp      */
  61
  62 /*
  63  * Definitions for the TELNET protocol.
  64  */
  65 #define IAC     255             /* interpret as command: */
  66 #define DONT    254             /* you are not to use option */
  67 #define DO      253             /* please, you use option */
  68 #define WONT    252             /* I won't use option */
  69 #define WILL    251             /* I will use option */
  70 #define SB      250             /* interpret as subnegotiation */
  71 #define GA      249             /* you may reverse the line */
  72 #define EL      248             /* erase the current line */
  73 #define EC      247             /* erase the current character */
  74 #define AYT     246             /* are you there */
  75 #define AO      245             /* abort output--but let prog finish */
  76 #define IP      244             /* interrupt process--permanently */
  77 #define BREAK   243             /* break */
  78 #define DM      242             /* data mark--for connect. cleaning */
  79 #define NOP     241             /* nop */
  80 #define SE      240             /* end sub negotiation */
  81 #define EOR     239             /* end of record (transparent mode) */
  82 #define ABORT   238             /* Abort process */
  83 #define SUSP    237             /* Suspend process */
  84 #define xEOF    236             /* End of file: EOF is already used... */
  85
  86 #define SYNCH   242             /* for telfunc calls */
  87
  88 #ifdef TELCMDS
  89 const char *telcmds[] = {
  90         "EOF", "SUSP", "ABORT", "EOR",
  91         "SE", "NOP", "DMARK", "BRK", "IP", "AO", "AYT", "EC",
  92         "EL", "GA", "SB", "WILL", "WONT", "DO", "DONT", "IAC", 0,
  93 };
  94 #else
  95 extern char *telcmds[];
  96 #endif
  97
  98 #define TELCMD_FIRST    xEOF
  99 #define TELCMD_LAST     IAC
 100 #define TELCMD_OK(x)    ((unsigned int)(x) <= TELCMD_LAST && \
 101                          (unsigned int)(x) >= TELCMD_FIRST)
 102 #define TELCMD(x)       telcmds[(x)-TELCMD_FIRST]
 103
 104 /* telnet options */
 105 #define TELOPT_BINARY   0       /* 8-bit data path */
 106 #define TELOPT_ECHO     1       /* echo */
 107 #define TELOPT_RCP      2       /* prepare to reconnect */
 108 #define TELOPT_SGA      3       /* suppress go ahead */
 109 #define TELOPT_NAMS     4       /* approximate message size */
 110 #define TELOPT_STATUS   5       /* give status */
 111 #define TELOPT_TM       6       /* timing mark */
 112 #define TELOPT_RCTE     7       /* remote controlled transmission and echo */
 113 #define TELOPT_NAOL     8       /* negotiate about output line width */
 114 #define TELOPT_NAOP     9       /* negotiate about output page size */
 115 #define TELOPT_NAOCRD   10      /* negotiate about CR disposition */
 116 #define TELOPT_NAOHTS   11      /* negotiate about horizontal tabstops */
 117 #define TELOPT_NAOHTD   12      /* negotiate about horizontal tab disposition */
 118 #define TELOPT_NAOFFD   13      /* negotiate about formfeed disposition */
 119 #define TELOPT_NAOVTS   14      /* negotiate about vertical tab stops */
 120 #define TELOPT_NAOVTD   15      /* negotiate about vertical tab disposition */
 121 #define TELOPT_NAOLFD   16      /* negotiate about output LF disposition */
 122 #define TELOPT_XASCII   17      /* extended ascic character set */
 123 #define TELOPT_LOGOUT   18      /* force logout */
 124 #define TELOPT_BM       19      /* byte macro */
 125 #define TELOPT_DET      20      /* data entry terminal */
 126 #define TELOPT_SUPDUP   21      /* supdup protocol */
 127 #define TELOPT_SUPDUPOUTPUT 22  /* supdup output */
 128 #define TELOPT_SNDLOC   23      /* send location */
 129 #define TELOPT_TTYPE    24      /* terminal type */
 130 #define TELOPT_EOR      25      /* end or record */
 131 #define TELOPT_TUID     26      /* TACACS user identification */
 132 #define TELOPT_OUTMRK   27      /* output marking */
 133 #define TELOPT_TTYLOC   28      /* terminal location number */
 134 #define TELOPT_3270REGIME 29    /* 3270 regime */
 135 #define TELOPT_X3PAD    30      /* X.3 PAD */
 136 #define TELOPT_NAWS     31      /* window size */
 137 #define TELOPT_TSPEED   32      /* terminal speed */
 138 #define TELOPT_LFLOW    33      /* remote flow control */
 139 #define TELOPT_LINEMODE 34      /* Linemode option */
 140 #define TELOPT_XDISPLOC 35      /* X Display Location */
 141 #define TELOPT_OLD_ENVIRON 36   /* Old - Environment variables */
 142 #define TELOPT_AUTHENTICATION 37/* Authenticate */
 143 #define TELOPT_ENCRYPT  38      /* Encryption option */
 144 #define TELOPT_NEW_ENVIRON 39   /* New - Environment variables */
 145 #define TELOPT_EXOPL    255     /* extended-options-list */
 146
 147
 148 #define NTELOPTS        (1+TELOPT_NEW_ENVIRON)
 149 #ifdef TELOPTS
 150 const char *telopts[NTELOPTS+1] = {
 151         "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME",
 152         "STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP",
 153         "NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS",
 154         "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT", "BYTE MACRO",
 155         "DATA ENTRY TERMINAL", "SUPDUP", "SUPDUP OUTPUT",
 156         "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD",
 157         "TACACS UID", "OUTPUT MARKING", "TTYLOC",
 158         "3270 REGIME", "X.3 PAD", "NAWS", "TSPEED", "LFLOW",
 159         "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION",
 160         "ENCRYPT", "NEW-ENVIRON",
 161         0,
 162 };
 163 #define TELOPT_FIRST    TELOPT_BINARY
 164 #define TELOPT_LAST     TELOPT_NEW_ENVIRON
 165 #define TELOPT_OK(x)    ((unsigned int)(x) <= TELOPT_LAST)
 166 #define TELOPT(x)       telopts[(x)-TELOPT_FIRST]
 167 #endif
 168
 169 /* sub-option qualifiers */
 170 #define TELQUAL_IS      0       /* option is... */
 171 #define TELQUAL_SEND    1       /* send option */
 172 #define TELQUAL_INFO    2       /* ENVIRON: informational version of IS */
 173 #define TELQUAL_REPLY   2       /* AUTHENTICATION: client version of IS */
 174 #define TELQUAL_NAME    3       /* AUTHENTICATION: client version of IS */
 175
 176 #define LFLOW_OFF               0       /* Disable remote flow control */
 177 #define LFLOW_ON                1       /* Enable remote flow control */
 178 #define LFLOW_RESTART_ANY       2       /* Restart output on any char */
 179 #define LFLOW_RESTART_XON       3       /* Restart output only on XON */
 180
 181 /*
 182  * LINEMODE suboptions
 183  */
 184
 185 #define LM_MODE         1
 186 #define LM_FORWARDMASK  2
 187 #define LM_SLC          3
 188
 189 #define MODE_EDIT       0x01
 190 #define MODE_TRAPSIG    0x02
 191 #define MODE_ACK        0x04
 192 #define MODE_SOFT_TAB   0x08
 193 #define MODE_LIT_ECHO   0x10
 194
 195 #define MODE_MASK       0x1f
 196
 197 #define SLC_SYNCH       1
 198 #define SLC_BRK         2
 199 #define SLC_IP          3
 200 #define SLC_AO          4
 201 #define SLC_AYT         5
 202 #define SLC_EOR         6
 203 #define SLC_ABORT       7
 204 #define SLC_EOF         8
 205 #define SLC_SUSP        9
 206 #define SLC_EC          10
 207 #define SLC_EL          11
 208 #define SLC_EW          12
 209 #define SLC_RP          13
 210 #define SLC_LNEXT       14
 211 #define SLC_XON         15
 212 #define SLC_XOFF        16
 213 #define SLC_FORW1       17
 214 #define SLC_FORW2       18
 215 #define SLC_MCL         19
 216 #define SLC_MCR         20
 217 #define SLC_MCWL        21
 218 #define SLC_MCWR        22
 219 #define SLC_MCBOL       23
 220 #define SLC_MCEOL       24
 221 #define SLC_INSRT       25
 222 #define SLC_OVER        26
 223 #define SLC_ECR         27
 224 #define SLC_EWR         28
 225 #define SLC_EBOL        29
 226 #define SLC_EEOL        30
 227
 228 #define NSLC            30
 229
 230 /*
 231  * For backwards compatibility, we define SLC_NAMES to be the
 232  * list of names if SLC_NAMES is not defined.
 233  */
 234 #define SLC_NAMELIST    "0", "SYNCH", "BRK", "IP", "AO", "AYT", "EOR",  \
 235                         "ABORT", "EOF", "SUSP", "EC", "EL", "EW", "RP", \
 236                         "LNEXT", "XON", "XOFF", "FORW1", "FORW2",       \
 237                         "MCL", "MCR", "MCWL", "MCWR", "MCBOL",          \
 238                         "MCEOL", "INSRT", "OVER", "ECR", "EWR",         \
 239                         "EBOL", "EEOL",                                 \
 240                         0,
 241
 242 #ifdef  SLC_NAMES
 243 const char *slc_names[] = {
 244         SLC_NAMELIST
 245 };
 246 #else
 247 extern char *slc_names[];
 248 #define SLC_NAMES SLC_NAMELIST
 249 #endif
 250
 251 #define SLC_NAME_OK(x)  ((unsigned int)(x) <= NSLC)
 252 #define SLC_NAME(x)     slc_names[x]
 253
 254 #define SLC_NOSUPPORT   0
 255 #define SLC_CANTCHANGE  1
 256 #define SLC_VARIABLE    2
 257 #define SLC_DEFAULT     3
 258 #define SLC_LEVELBITS   0x03
 259
 260 #define SLC_FUNC        0
 261 #define SLC_FLAGS       1
 262 #define SLC_VALUE       2
 263
 264 #define SLC_ACK         0x80
 265 #define SLC_FLUSHIN     0x40
 266 #define SLC_FLUSHOUT    0x20
 267
 268 #define OLD_ENV_VAR     1
 269 #define OLD_ENV_VALUE   0
 270 #define NEW_ENV_VAR     0
 271 #define NEW_ENV_VALUE   1
 272 #define ENV_ESC         2
 273 #define ENV_USERVAR     3
 274
 275 /*
 276  * AUTHENTICATION suboptions
 277  */
 278
 279 /*
 280  * Who is authenticating who ...
 281  */
 282 #define AUTH_WHO_CLIENT         0       /* Client authenticating server */
 283 #define AUTH_WHO_SERVER         1       /* Server authenticating client */
 284 #define AUTH_WHO_MASK           1
 285
 286 #define AUTHTYPE_NULL           0
 287 #define AUTHTYPE_KERBEROS_V4    1
 288 #define AUTHTYPE_KERBEROS_V5    2
 289 #define AUTHTYPE_SPX            3
 290 #define AUTHTYPE_MINK           4
 291 #define AUTHTYPE_CNT            5
 292
 293 #define AUTHTYPE_TEST           99
 294
 295 #ifdef  AUTH_NAMES
 296 const char *authtype_names[] = {
 297         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 0,
 298 };
 299 #else
 300 extern char *authtype_names[];
 301 #endif
 302
 303 #define AUTHTYPE_NAME_OK(x)     ((unsigned int)(x) < AUTHTYPE_CNT)
 304 #define AUTHTYPE_NAME(x)        authtype_names[x]
 305
 306 /*
 307  * ENCRYPTion suboptions
 308  */
 309 #define ENCRYPT_IS              0       /* I pick encryption type ... */
 310 #define ENCRYPT_SUPPORT         1       /* I support encryption types ... */
 311 #define ENCRYPT_REPLY           2       /* Initial setup response */
 312 #define ENCRYPT_START           3       /* Am starting to send encrypted */
 313 #define ENCRYPT_END             4       /* Am ending encrypted */
 314 #define ENCRYPT_REQSTART        5       /* Request you start encrypting */
 315 #define ENCRYPT_REQEND          6       /* Request you send encrypting */
 316 #define ENCRYPT_ENC_KEYID       7
 317 #define ENCRYPT_DEC_KEYID       8
 318 #define ENCRYPT_CNT             9
 319
 320 #define ENCTYPE_ANY             0
 321 #define ENCTYPE_DES_CFB64       1
 322 #define ENCTYPE_DES_OFB64       2
 323 #define ENCTYPE_CNT             3
 324
 325 #ifdef  ENCRYPT_NAMES
 326 const char *encrypt_names[] = {
 327         "IS", "SUPPORT", "REPLY", "START", "END",
 328         "REQUEST-START", "REQUEST-END", "ENC-KEYID", "DEC-KEYID",
 329         0,
 330 };
 331 const char *enctype_names[] = {
 332         "ANY", "DES_CFB64",  "DES_OFB64",  0,
 333 };
 334 #else
 335 extern char *encrypt_names[];
 336 extern char *enctype_names[];
 337 #endif
 338
 339 #define ENCRYPT_NAME_OK(x)      ((unsigned int)(x) < ENCRYPT_CNT)
 340 #define ENCRYPT_NAME(x)         encrypt_names[x]
 341
 342 #define ENCTYPE_NAME_OK(x)      ((unsigned int)(x) < ENCTYPE_CNT)
 343 #define ENCTYPE_NAME(x)         enctype_names[x]
 344
 345 /* normal */
 346 static const char *cmds[] = {
 347         "IS", "SEND", "INFO",
 348 };
 349
 350 /* 37: Authentication */
 351 static const char *authcmd[] = {
 352         "IS", "SEND", "REPLY", "NAME",
 353 };
 354 static const char *authtype[] = {
 355         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
 356         "SRP", "RSA", "SSL", NULL, NULL,
 357         "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
 358         "NTLM",
 359 };
 360
 361 /* 38: Encryption */
 362 static const char *enccmd[] = {
 363         "IS", "SUPPORT", "REPLY", "START", "END",
 364         "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
 365 };
 366 static const char *enctype[] = {
 367         "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
 368         NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
 369 };
 370
 371 #define STR_OR_ID(x, tab) \
 372         (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))
 373
 374 static char *
 375 numstr(int x)
 376 {
 377         static char buf[20];
 378
 379         snprintf(buf, sizeof(buf), "%#x", x);
 380         return buf;
 381 }
 382
 383 /* sp points to IAC byte */
 384 static int
 385 telnet_parse(netdissect_options *ndo, const u_char *sp, u_int length, int print)
 386 {
 387         int i, x;
 388         u_int c;
 389         const u_char *osp, *p;
 390 #define FETCH(c, sp, length) \
 391         do { \
 392                 if (length < 1) \
 393                         goto pktend; \
 394                 ND_TCHECK(*sp); \
 395                 c = *sp++; \
 396                 length--; \
 397         } while (0)
 398
 399         osp = sp;
 400
 401         FETCH(c, sp, length);
 402         if (c != IAC)
 403                 goto pktend;
 404         FETCH(c, sp, length);
 405         if (c == IAC) {         /* <IAC><IAC>! */
 406                 if (print)
 407                         ND_PRINT((ndo, "IAC IAC"));
 408                 goto done;
 409         }
 410
 411         i = c - TELCMD_FIRST;
 412         if (i < 0 || i > IAC - TELCMD_FIRST)
 413                 goto pktend;
 414
 415         switch (c) {
 416         case DONT:
 417         case DO:
 418         case WONT:
 419         case WILL:
 420         case SB:
 421                 /* DONT/DO/WONT/WILL x */
 422                 FETCH(x, sp, length);
 423                 if (x >= 0 && x < NTELOPTS) {
 424                         if (print)
 425                                 ND_PRINT((ndo, "%s %s", telcmds[i], telopts[x]));
 426                 } else {
 427                         if (print)
 428                                 ND_PRINT((ndo, "%s %#x", telcmds[i], x));
 429                 }
 430                 if (c != SB)
 431                         break;
 432                 /* IAC SB .... IAC SE */
 433                 p = sp;
 434                 while (length > (u_int)(p + 1 - sp)) {
 435                         if (p[0] == IAC && p[1] == SE)
 436                                 break;
 437                         p++;
 438                 }
 439                 if (*p != IAC)
 440                         goto pktend;
 441
 442                 switch (x) {
 443                 case TELOPT_AUTHENTICATION:
 444                         if (p <= sp)
 445                                 break;
 446                         FETCH(c, sp, length);
 447                         if (print)
 448                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, authcmd)));
 449                         if (p <= sp)
 450                                 break;
 451                         FETCH(c, sp, length);
 452                         if (print)
 453                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, authtype)));
 454                         break;
 455                 case TELOPT_ENCRYPT:
 456                         if (p <= sp)
 457                                 break;
 458                         FETCH(c, sp, length);
 459                         if (print)
 460                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, enccmd)));
 461                         if (p <= sp)
 462                                 break;
 463                         FETCH(c, sp, length);
 464                         if (print)
 465                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, enctype)));
 466                         break;
 467                 default:
 468                         if (p <= sp)
 469                                 break;
 470                         FETCH(c, sp, length);
 471                         if (print)
 472                                 ND_PRINT((ndo, " %s", STR_OR_ID(c, cmds)));
 473                         break;
 474                 }
 475                 while (p > sp) {
 476                         FETCH(x, sp, length);
 477                         if (print)
 478                                 ND_PRINT((ndo, " %#x", x));
 479                 }
 480                 /* terminating IAC SE */
 481                 if (print)
 482                         ND_PRINT((ndo, " SE"));
 483                 sp += 2;
 484                 break;
 485         default:
 486                 if (print)
 487                         ND_PRINT((ndo, "%s", telcmds[i]));
 488                 goto done;
 489         }
 490
 491 done:
 492         return sp - osp;
 493
 494 trunc:
 495         ND_PRINT((ndo, "[|telnet]"));
 496 pktend:
 497         return -1;
 498 #undef FETCH
 499 }
 500
 501 void
 502 telnet_print(netdissect_options *ndo, const u_char *sp, u_int length)
 503 {
 504         int first = 1;
 505         const u_char *osp;
 506         int l;
 507
 508         osp = sp;
 509
 510         while (length > 0 && *sp == IAC) {
 511                 /*
 512                  * Parse the Telnet command without printing it,
 513                  * to determine its length.
 514                  */
 515                 l = telnet_parse(ndo, sp, length, 0);
 516                 if (l < 0)
 517                         break;
 518
 519                 /*
 520                  * now print it
 521                  */
 522                 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) {
 523                         if (first)
 524                                 ND_PRINT((ndo, "\nTelnet:"));
 525                         hex_print_with_offset(ndo, "\n", sp, l, sp - osp);
 526                         if (l > 8)
 527                                 ND_PRINT((ndo, "\n\t\t\t\t"));
 528                         else
 529                                 ND_PRINT((ndo, "%*s\t", (8 - l) * 3, ""));
 530                 } else
 531                         ND_PRINT((ndo, "%s", (first) ? " [telnet " : ", "));
 532
 533                 (void)telnet_parse(ndo, sp, length, 1);
 534                 first = 0;
 535
 536                 sp += l;
 537                 length -= l;
 538         }
 539         if (!first) {
 540                 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag)
 541                         ND_PRINT((ndo, "\n"));
 542                 else
 543                         ND_PRINT((ndo, "]"));
 544         }
 545 }