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 } 558