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 1.8 2017/09/08 14:01:13 christos Exp $"); 44 #endif 45 46 /* \summary: Telnet option printer */ 47 48 #ifdef HAVE_CONFIG_H 49 #include "config.h" 50 #endif 51 52 #include <netdissect-stdinc.h> 53 54 #include <stdio.h> 55 56 #include "netdissect.h" 57 58 static const char tstr[] = " [|telnet]"; 59 60 #define TELCMDS 61 #define TELOPTS 62 63 /* NetBSD: telnet.h,v 1.9 2001/06/11 01:50:50 wiz Exp */ 64 65 /* 66 * Definitions for the TELNET protocol. 67 */ 68 #define IAC 255 /* interpret as command: */ 69 #define DONT 254 /* you are not to use option */ 70 #define DO 253 /* please, you use option */ 71 #define WONT 252 /* I won't use option */ 72 #define WILL 251 /* I will use option */ 73 #define SB 250 /* interpret as subnegotiation */ 74 #define GA 249 /* you may reverse the line */ 75 #define EL 248 /* erase the current line */ 76 #define EC 247 /* erase the current character */ 77 #define AYT 246 /* are you there */ 78 #define AO 245 /* abort output--but let prog finish */ 79 #define IP 244 /* interrupt process--permanently */ 80 #define BREAK 243 /* break */ 81 #define DM 242 /* data mark--for connect. cleaning */ 82 #define NOP 241 /* nop */ 83 #define SE 240 /* end sub negotiation */ 84 #define EOR 239 /* end of record (transparent mode) */ 85 #define ABORT 238 /* Abort process */ 86 #define SUSP 237 /* Suspend process */ 87 #define xEOF 236 /* End of file: EOF is already used... */ 88 89 #define SYNCH 242 /* for telfunc calls */ 90 91 #ifdef TELCMDS 92 static const char *telcmds[] = { 93 "EOF", "SUSP", "ABORT", "EOR", 94 "SE", "NOP", "DMARK", "BRK", "IP", "AO", "AYT", "EC", 95 "EL", "GA", "SB", "WILL", "WONT", "DO", "DONT", "IAC", 0, 96 }; 97 #else 98 extern char *telcmds[]; 99 #endif 100 101 #define TELCMD_FIRST xEOF 102 #define TELCMD_LAST IAC 103 #define TELCMD_OK(x) ((unsigned int)(x) <= TELCMD_LAST && \ 104 (unsigned int)(x) >= TELCMD_FIRST) 105 #define TELCMD(x) telcmds[(x)-TELCMD_FIRST] 106 107 /* telnet options */ 108 #define TELOPT_BINARY 0 /* 8-bit data path */ 109 #define TELOPT_ECHO 1 /* echo */ 110 #define TELOPT_RCP 2 /* prepare to reconnect */ 111 #define TELOPT_SGA 3 /* suppress go ahead */ 112 #define TELOPT_NAMS 4 /* approximate message size */ 113 #define TELOPT_STATUS 5 /* give status */ 114 #define TELOPT_TM 6 /* timing mark */ 115 #define TELOPT_RCTE 7 /* remote controlled transmission and echo */ 116 #define TELOPT_NAOL 8 /* negotiate about output line width */ 117 #define TELOPT_NAOP 9 /* negotiate about output page size */ 118 #define TELOPT_NAOCRD 10 /* negotiate about CR disposition */ 119 #define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */ 120 #define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */ 121 #define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */ 122 #define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */ 123 #define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */ 124 #define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */ 125 #define TELOPT_XASCII 17 /* extended ascic character set */ 126 #define TELOPT_LOGOUT 18 /* force logout */ 127 #define TELOPT_BM 19 /* byte macro */ 128 #define TELOPT_DET 20 /* data entry terminal */ 129 #define TELOPT_SUPDUP 21 /* supdup protocol */ 130 #define TELOPT_SUPDUPOUTPUT 22 /* supdup output */ 131 #define TELOPT_SNDLOC 23 /* send location */ 132 #define TELOPT_TTYPE 24 /* terminal type */ 133 #define TELOPT_EOR 25 /* end or record */ 134 #define TELOPT_TUID 26 /* TACACS user identification */ 135 #define TELOPT_OUTMRK 27 /* output marking */ 136 #define TELOPT_TTYLOC 28 /* terminal location number */ 137 #define TELOPT_3270REGIME 29 /* 3270 regime */ 138 #define TELOPT_X3PAD 30 /* X.3 PAD */ 139 #define TELOPT_NAWS 31 /* window size */ 140 #define TELOPT_TSPEED 32 /* terminal speed */ 141 #define TELOPT_LFLOW 33 /* remote flow control */ 142 #define TELOPT_LINEMODE 34 /* Linemode option */ 143 #define TELOPT_XDISPLOC 35 /* X Display Location */ 144 #define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */ 145 #define TELOPT_AUTHENTICATION 37/* Authenticate */ 146 #define TELOPT_ENCRYPT 38 /* Encryption option */ 147 #define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */ 148 #define TELOPT_EXOPL 255 /* extended-options-list */ 149 150 151 #define NTELOPTS (1+TELOPT_NEW_ENVIRON) 152 #ifdef TELOPTS 153 static const char *telopts[NTELOPTS+1] = { 154 "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME", 155 "STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP", 156 "NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS", 157 "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT", "BYTE MACRO", 158 "DATA ENTRY TERMINAL", "SUPDUP", "SUPDUP OUTPUT", 159 "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD", 160 "TACACS UID", "OUTPUT MARKING", "TTYLOC", 161 "3270 REGIME", "X.3 PAD", "NAWS", "TSPEED", "LFLOW", 162 "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION", 163 "ENCRYPT", "NEW-ENVIRON", 164 0, 165 }; 166 #define TELOPT_FIRST TELOPT_BINARY 167 #define TELOPT_LAST TELOPT_NEW_ENVIRON 168 #define TELOPT_OK(x) ((unsigned int)(x) <= TELOPT_LAST) 169 #define TELOPT(x) telopts[(x)-TELOPT_FIRST] 170 #endif 171 172 /* sub-option qualifiers */ 173 #define TELQUAL_IS 0 /* option is... */ 174 #define TELQUAL_SEND 1 /* send option */ 175 #define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */ 176 #define TELQUAL_REPLY 2 /* AUTHENTICATION: client version of IS */ 177 #define TELQUAL_NAME 3 /* AUTHENTICATION: client version of IS */ 178 179 #define LFLOW_OFF 0 /* Disable remote flow control */ 180 #define LFLOW_ON 1 /* Enable remote flow control */ 181 #define LFLOW_RESTART_ANY 2 /* Restart output on any char */ 182 #define LFLOW_RESTART_XON 3 /* Restart output only on XON */ 183 184 /* 185 * LINEMODE suboptions 186 */ 187 188 #define LM_MODE 1 189 #define LM_FORWARDMASK 2 190 #define LM_SLC 3 191 192 #define MODE_EDIT 0x01 193 #define MODE_TRAPSIG 0x02 194 #define MODE_ACK 0x04 195 #define MODE_SOFT_TAB 0x08 196 #define MODE_LIT_ECHO 0x10 197 198 #define MODE_MASK 0x1f 199 200 #define SLC_SYNCH 1 201 #define SLC_BRK 2 202 #define SLC_IP 3 203 #define SLC_AO 4 204 #define SLC_AYT 5 205 #define SLC_EOR 6 206 #define SLC_ABORT 7 207 #define SLC_EOF 8 208 #define SLC_SUSP 9 209 #define SLC_EC 10 210 #define SLC_EL 11 211 #define SLC_EW 12 212 #define SLC_RP 13 213 #define SLC_LNEXT 14 214 #define SLC_XON 15 215 #define SLC_XOFF 16 216 #define SLC_FORW1 17 217 #define SLC_FORW2 18 218 #define SLC_MCL 19 219 #define SLC_MCR 20 220 #define SLC_MCWL 21 221 #define SLC_MCWR 22 222 #define SLC_MCBOL 23 223 #define SLC_MCEOL 24 224 #define SLC_INSRT 25 225 #define SLC_OVER 26 226 #define SLC_ECR 27 227 #define SLC_EWR 28 228 #define SLC_EBOL 29 229 #define SLC_EEOL 30 230 231 #define NSLC 30 232 233 /* 234 * For backwards compatibility, we define SLC_NAMES to be the 235 * list of names if SLC_NAMES is not defined. 236 */ 237 #define SLC_NAMELIST "0", "SYNCH", "BRK", "IP", "AO", "AYT", "EOR", \ 238 "ABORT", "EOF", "SUSP", "EC", "EL", "EW", "RP", \ 239 "LNEXT", "XON", "XOFF", "FORW1", "FORW2", \ 240 "MCL", "MCR", "MCWL", "MCWR", "MCBOL", \ 241 "MCEOL", "INSRT", "OVER", "ECR", "EWR", \ 242 "EBOL", "EEOL", \ 243 0, 244 245 #ifdef SLC_NAMES 246 const char *slc_names[] = { 247 SLC_NAMELIST 248 }; 249 #else 250 extern char *slc_names[]; 251 #define SLC_NAMES SLC_NAMELIST 252 #endif 253 254 #define SLC_NAME_OK(x) ((unsigned int)(x) <= NSLC) 255 #define SLC_NAME(x) slc_names[x] 256 257 #define SLC_NOSUPPORT 0 258 #define SLC_CANTCHANGE 1 259 #define SLC_VARIABLE 2 260 #define SLC_DEFAULT 3 261 #define SLC_LEVELBITS 0x03 262 263 #define SLC_FUNC 0 264 #define SLC_FLAGS 1 265 #define SLC_VALUE 2 266 267 #define SLC_ACK 0x80 268 #define SLC_FLUSHIN 0x40 269 #define SLC_FLUSHOUT 0x20 270 271 #define OLD_ENV_VAR 1 272 #define OLD_ENV_VALUE 0 273 #define NEW_ENV_VAR 0 274 #define NEW_ENV_VALUE 1 275 #define ENV_ESC 2 276 #define ENV_USERVAR 3 277 278 /* 279 * AUTHENTICATION suboptions 280 */ 281 282 /* 283 * Who is authenticating who ... 284 */ 285 #define AUTH_WHO_CLIENT 0 /* Client authenticating server */ 286 #define AUTH_WHO_SERVER 1 /* Server authenticating client */ 287 #define AUTH_WHO_MASK 1 288 289 #define AUTHTYPE_NULL 0 290 #define AUTHTYPE_KERBEROS_V4 1 291 #define AUTHTYPE_KERBEROS_V5 2 292 #define AUTHTYPE_SPX 3 293 #define AUTHTYPE_MINK 4 294 #define AUTHTYPE_CNT 5 295 296 #define AUTHTYPE_TEST 99 297 298 #ifdef AUTH_NAMES 299 const char *authtype_names[] = { 300 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 0, 301 }; 302 #else 303 extern char *authtype_names[]; 304 #endif 305 306 #define AUTHTYPE_NAME_OK(x) ((unsigned int)(x) < AUTHTYPE_CNT) 307 #define AUTHTYPE_NAME(x) authtype_names[x] 308 309 /* 310 * ENCRYPTion suboptions 311 */ 312 #define ENCRYPT_IS 0 /* I pick encryption type ... */ 313 #define ENCRYPT_SUPPORT 1 /* I support encryption types ... */ 314 #define ENCRYPT_REPLY 2 /* Initial setup response */ 315 #define ENCRYPT_START 3 /* Am starting to send encrypted */ 316 #define ENCRYPT_END 4 /* Am ending encrypted */ 317 #define ENCRYPT_REQSTART 5 /* Request you start encrypting */ 318 #define ENCRYPT_REQEND 6 /* Request you send encrypting */ 319 #define ENCRYPT_ENC_KEYID 7 320 #define ENCRYPT_DEC_KEYID 8 321 #define ENCRYPT_CNT 9 322 323 #define ENCTYPE_ANY 0 324 #define ENCTYPE_DES_CFB64 1 325 #define ENCTYPE_DES_OFB64 2 326 #define ENCTYPE_CNT 3 327 328 #ifdef ENCRYPT_NAMES 329 const char *encrypt_names[] = { 330 "IS", "SUPPORT", "REPLY", "START", "END", 331 "REQUEST-START", "REQUEST-END", "ENC-KEYID", "DEC-KEYID", 332 0, 333 }; 334 const char *enctype_names[] = { 335 "ANY", "DES_CFB64", "DES_OFB64", 0, 336 }; 337 #else 338 extern char *encrypt_names[]; 339 extern char *enctype_names[]; 340 #endif 341 342 #define ENCRYPT_NAME_OK(x) ((unsigned int)(x) < ENCRYPT_CNT) 343 #define ENCRYPT_NAME(x) encrypt_names[x] 344 345 #define ENCTYPE_NAME_OK(x) ((unsigned int)(x) < ENCTYPE_CNT) 346 #define ENCTYPE_NAME(x) enctype_names[x] 347 348 /* normal */ 349 static const char *cmds[] = { 350 "IS", "SEND", "INFO", 351 }; 352 353 /* 37: Authentication */ 354 static const char *authcmd[] = { 355 "IS", "SEND", "REPLY", "NAME", 356 }; 357 static const char *authtype[] = { 358 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 359 "SRP", "RSA", "SSL", NULL, NULL, 360 "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS", 361 "NTLM", 362 }; 363 364 /* 38: Encryption */ 365 static const char *enccmd[] = { 366 "IS", "SUPPORT", "REPLY", "START", "END", 367 "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID", 368 }; 369 static const char *enctype[] = { 370 "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64", 371 NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64", 372 }; 373 374 #define STR_OR_ID(x, tab) \ 375 (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x)) 376 377 static char * 378 numstr(int x) 379 { 380 static char buf[20]; 381 382 snprintf(buf, sizeof(buf), "%#x", x); 383 return buf; 384 } 385 386 /* sp points to IAC byte */ 387 static int 388 telnet_parse(netdissect_options *ndo, const u_char *sp, u_int length, int print) 389 { 390 int i, x; 391 u_int c; 392 const u_char *osp, *p; 393 #define FETCH(c, sp, length) \ 394 do { \ 395 if (length < 1) \ 396 goto pktend; \ 397 ND_TCHECK(*sp); \ 398 c = *sp++; \ 399 length--; \ 400 } while (0) 401 402 osp = sp; 403 404 FETCH(c, sp, length); 405 if (c != IAC) 406 goto pktend; 407 FETCH(c, sp, length); 408 if (c == IAC) { /* <IAC><IAC>! */ 409 if (print) 410 ND_PRINT((ndo, "IAC IAC")); 411 goto done; 412 } 413 414 i = c - TELCMD_FIRST; 415 if (i < 0 || i > IAC - TELCMD_FIRST) 416 goto pktend; 417 418 switch (c) { 419 case DONT: 420 case DO: 421 case WONT: 422 case WILL: 423 case SB: 424 /* DONT/DO/WONT/WILL x */ 425 FETCH(x, sp, length); 426 if (x >= 0 && x < NTELOPTS) { 427 if (print) 428 ND_PRINT((ndo, "%s %s", telcmds[i], telopts[x])); 429 } else { 430 if (print) 431 ND_PRINT((ndo, "%s %#x", telcmds[i], x)); 432 } 433 if (c != SB) 434 break; 435 /* IAC SB .... IAC SE */ 436 p = sp; 437 while (length > (u_int)(p + 1 - sp)) { 438 ND_TCHECK2(*p, 2); 439 if (p[0] == IAC && p[1] == SE) 440 break; 441 p++; 442 } 443 ND_TCHECK(*p); 444 if (*p != IAC) 445 goto pktend; 446 447 switch (x) { 448 case TELOPT_AUTHENTICATION: 449 if (p <= sp) 450 break; 451 FETCH(c, sp, length); 452 if (print) 453 ND_PRINT((ndo, " %s", STR_OR_ID(c, authcmd))); 454 if (p <= sp) 455 break; 456 FETCH(c, sp, length); 457 if (print) 458 ND_PRINT((ndo, " %s", STR_OR_ID(c, authtype))); 459 break; 460 case TELOPT_ENCRYPT: 461 if (p <= sp) 462 break; 463 FETCH(c, sp, length); 464 if (print) 465 ND_PRINT((ndo, " %s", STR_OR_ID(c, enccmd))); 466 if (p <= sp) 467 break; 468 FETCH(c, sp, length); 469 if (print) 470 ND_PRINT((ndo, " %s", STR_OR_ID(c, enctype))); 471 break; 472 default: 473 if (p <= sp) 474 break; 475 FETCH(c, sp, length); 476 if (print) 477 ND_PRINT((ndo, " %s", STR_OR_ID(c, cmds))); 478 break; 479 } 480 while (p > sp) { 481 FETCH(x, sp, length); 482 if (print) 483 ND_PRINT((ndo, " %#x", x)); 484 } 485 /* terminating IAC SE */ 486 if (print) 487 ND_PRINT((ndo, " SE")); 488 sp += 2; 489 break; 490 default: 491 if (print) 492 ND_PRINT((ndo, "%s", telcmds[i])); 493 goto done; 494 } 495 496 done: 497 return sp - osp; 498 499 trunc: 500 ND_PRINT((ndo, "%s", tstr)); 501 pktend: 502 return -1; 503 #undef FETCH 504 } 505 506 void 507 telnet_print(netdissect_options *ndo, const u_char *sp, u_int length) 508 { 509 int first = 1; 510 const u_char *osp; 511 int l; 512 513 osp = sp; 514 515 ND_TCHECK(*sp); 516 while (length > 0 && *sp == IAC) { 517 /* 518 * Parse the Telnet command without printing it, 519 * to determine its length. 520 */ 521 l = telnet_parse(ndo, sp, length, 0); 522 if (l < 0) 523 break; 524 525 /* 526 * now print it 527 */ 528 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) { 529 if (first) 530 ND_PRINT((ndo, "\nTelnet:")); 531 hex_print_with_offset(ndo, "\n", sp, l, sp - osp); 532 if (l > 8) 533 ND_PRINT((ndo, "\n\t\t\t\t")); 534 else 535 ND_PRINT((ndo, "%*s\t", (8 - l) * 3, "")); 536 } else 537 ND_PRINT((ndo, "%s", (first) ? " [telnet " : ", ")); 538 539 (void)telnet_parse(ndo, sp, length, 1); 540 first = 0; 541 542 sp += l; 543 length -= l; 544 ND_TCHECK(*sp); 545 } 546 if (!first) { 547 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) 548 ND_PRINT((ndo, "\n")); 549 else 550 ND_PRINT((ndo, "]")); 551 } 552 return; 553 trunc: 554 ND_PRINT((ndo, "%s", tstr)); 555 } 556