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 1.10 2024/09/02 16:15:33 christos Exp $"); 44 #endif 45 46 /* \summary: Telnet option printer */ 47 48 #include <config.h> 49 50 #include "netdissect-stdinc.h" 51 52 #include <stdio.h> 53 54 #include "netdissect.h" 55 #include "extract.h" 56 57 58 /* NetBSD: telnet.h,v 1.9 2001/06/11 01:50:50 wiz Exp */ 59 60 /* 61 * Definitions for the TELNET protocol. 62 */ 63 #define IAC 255 /* interpret as command: */ 64 #define DONT 254 /* you are not to use option */ 65 #define DO 253 /* please, you use option */ 66 #define WONT 252 /* I won't use option */ 67 #define WILL 251 /* I will use option */ 68 #define SB 250 /* interpret as subnegotiation */ 69 #define GA 249 /* you may reverse the line */ 70 #define EL 248 /* erase the current line */ 71 #define EC 247 /* erase the current character */ 72 #define AYT 246 /* are you there */ 73 #define AO 245 /* abort output--but let prog finish */ 74 #define IP 244 /* interrupt process--permanently */ 75 #define BREAK 243 /* break */ 76 #define DM 242 /* data mark--for connect. cleaning */ 77 #define NOP 241 /* nop */ 78 #define SE 240 /* end sub negotiation */ 79 #define EOR 239 /* end of record (transparent mode) */ 80 #define ABORT 238 /* Abort process */ 81 #define SUSP 237 /* Suspend process */ 82 #define xEOF 236 /* End of file: EOF is already used... */ 83 84 #define SYNCH 242 /* for telfunc calls */ 85 86 static const char *telcmds[] = { 87 "EOF", "SUSP", "ABORT", "EOR", 88 "SE", "NOP", "DMARK", "BRK", "IP", "AO", "AYT", "EC", 89 "EL", "GA", "SB", "WILL", "WONT", "DO", "DONT", "IAC", 0, 90 }; 91 92 #define TELCMD_FIRST xEOF 93 #define TELCMD_LAST IAC 94 #define TELCMD_OK(x) ((unsigned int)(x) <= TELCMD_LAST && \ 95 (unsigned int)(x) >= TELCMD_FIRST) 96 #define TELCMD(x) telcmds[(x)-TELCMD_FIRST] 97 98 /* telnet options */ 99 #define TELOPT_BINARY 0 /* 8-bit data path */ 100 #define TELOPT_ECHO 1 /* echo */ 101 #define TELOPT_RCP 2 /* prepare to reconnect */ 102 #define TELOPT_SGA 3 /* suppress go ahead */ 103 #define TELOPT_NAMS 4 /* approximate message size */ 104 #define TELOPT_STATUS 5 /* give status */ 105 #define TELOPT_TM 6 /* timing mark */ 106 #define TELOPT_RCTE 7 /* remote controlled transmission and echo */ 107 #define TELOPT_NAOL 8 /* negotiate about output line width */ 108 #define TELOPT_NAOP 9 /* negotiate about output page size */ 109 #define TELOPT_NAOCRD 10 /* negotiate about CR disposition */ 110 #define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */ 111 #define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */ 112 #define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */ 113 #define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */ 114 #define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */ 115 #define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */ 116 #define TELOPT_XASCII 17 /* extended ascii character set */ 117 #define TELOPT_LOGOUT 18 /* force logout */ 118 #define TELOPT_BM 19 /* byte macro */ 119 #define TELOPT_DET 20 /* data entry terminal */ 120 #define TELOPT_SUPDUP 21 /* supdup protocol */ 121 #define TELOPT_SUPDUPOUTPUT 22 /* supdup output */ 122 #define TELOPT_SNDLOC 23 /* send location */ 123 #define TELOPT_TTYPE 24 /* terminal type */ 124 #define TELOPT_EOR 25 /* end or record */ 125 #define TELOPT_TUID 26 /* TACACS user identification */ 126 #define TELOPT_OUTMRK 27 /* output marking */ 127 #define TELOPT_TTYLOC 28 /* terminal location number */ 128 #define TELOPT_3270REGIME 29 /* 3270 regime */ 129 #define TELOPT_X3PAD 30 /* X.3 PAD */ 130 #define TELOPT_NAWS 31 /* window size */ 131 #define TELOPT_TSPEED 32 /* terminal speed */ 132 #define TELOPT_LFLOW 33 /* remote flow control */ 133 #define TELOPT_LINEMODE 34 /* Linemode option */ 134 #define TELOPT_XDISPLOC 35 /* X Display Location */ 135 #define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */ 136 #define TELOPT_AUTHENTICATION 37/* Authenticate */ 137 #define TELOPT_ENCRYPT 38 /* Encryption option */ 138 #define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */ 139 #define TELOPT_EXOPL 255 /* extended-options-list */ 140 141 142 #define NTELOPTS (1+TELOPT_NEW_ENVIRON) 143 static const char *telopts[NTELOPTS+1] = { 144 "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME", 145 "STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP", 146 "NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS", 147 "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT", "BYTE MACRO", 148 "DATA ENTRY TERMINAL", "SUPDUP", "SUPDUP OUTPUT", 149 "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD", 150 "TACACS UID", "OUTPUT MARKING", "TTYLOC", 151 "3270 REGIME", "X.3 PAD", "NAWS", "TSPEED", "LFLOW", 152 "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION", 153 "ENCRYPT", "NEW-ENVIRON", 154 0, 155 }; 156 #define TELOPT_FIRST TELOPT_BINARY 157 #define TELOPT_LAST TELOPT_NEW_ENVIRON 158 #define TELOPT_OK(x) ((unsigned int)(x) <= TELOPT_LAST) 159 #define TELOPT(x) telopts[(x)-TELOPT_FIRST] 160 161 /* sub-option qualifiers */ 162 #define TELQUAL_IS 0 /* option is... */ 163 #define TELQUAL_SEND 1 /* send option */ 164 #define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */ 165 #define TELQUAL_REPLY 2 /* AUTHENTICATION: client version of IS */ 166 #define TELQUAL_NAME 3 /* AUTHENTICATION: client version of IS */ 167 168 #define LFLOW_OFF 0 /* Disable remote flow control */ 169 #define LFLOW_ON 1 /* Enable remote flow control */ 170 #define LFLOW_RESTART_ANY 2 /* Restart output on any char */ 171 #define LFLOW_RESTART_XON 3 /* Restart output only on XON */ 172 173 /* 174 * LINEMODE suboptions 175 */ 176 177 #define LM_MODE 1 178 #define LM_FORWARDMASK 2 179 #define LM_SLC 3 180 181 #define MODE_EDIT 0x01 182 #define MODE_TRAPSIG 0x02 183 #define MODE_ACK 0x04 184 #define MODE_SOFT_TAB 0x08 185 #define MODE_LIT_ECHO 0x10 186 187 #define MODE_MASK 0x1f 188 189 #define SLC_SYNCH 1 190 #define SLC_BRK 2 191 #define SLC_IP 3 192 #define SLC_AO 4 193 #define SLC_AYT 5 194 #define SLC_EOR 6 195 #define SLC_ABORT 7 196 #define SLC_EOF 8 197 #define SLC_SUSP 9 198 #define SLC_EC 10 199 #define SLC_EL 11 200 #define SLC_EW 12 201 #define SLC_RP 13 202 #define SLC_LNEXT 14 203 #define SLC_XON 15 204 #define SLC_XOFF 16 205 #define SLC_FORW1 17 206 #define SLC_FORW2 18 207 #define SLC_MCL 19 208 #define SLC_MCR 20 209 #define SLC_MCWL 21 210 #define SLC_MCWR 22 211 #define SLC_MCBOL 23 212 #define SLC_MCEOL 24 213 #define SLC_INSRT 25 214 #define SLC_OVER 26 215 #define SLC_ECR 27 216 #define SLC_EWR 28 217 #define SLC_EBOL 29 218 #define SLC_EEOL 30 219 220 #define NSLC 30 221 222 /* 223 * For backwards compatibility, we define SLC_NAMES to be the 224 * list of names if SLC_NAMES is not defined. 225 */ 226 #define SLC_NAMELIST "0", "SYNCH", "BRK", "IP", "AO", "AYT", "EOR", \ 227 "ABORT", "EOF", "SUSP", "EC", "EL", "EW", "RP", \ 228 "LNEXT", "XON", "XOFF", "FORW1", "FORW2", \ 229 "MCL", "MCR", "MCWL", "MCWR", "MCBOL", \ 230 "MCEOL", "INSRT", "OVER", "ECR", "EWR", \ 231 "EBOL", "EEOL", \ 232 0, 233 234 #ifdef SLC_NAMES 235 const char *slc_names[] = { 236 SLC_NAMELIST 237 }; 238 #else 239 extern char *slc_names[]; 240 #define SLC_NAMES SLC_NAMELIST 241 #endif 242 243 #define SLC_NAME_OK(x) ((unsigned int)(x) <= NSLC) 244 #define SLC_NAME(x) slc_names[x] 245 246 #define SLC_NOSUPPORT 0 247 #define SLC_CANTCHANGE 1 248 #define SLC_VARIABLE 2 249 #define SLC_DEFAULT 3 250 #define SLC_LEVELBITS 0x03 251 252 #define SLC_FUNC 0 253 #define SLC_FLAGS 1 254 #define SLC_VALUE 2 255 256 #define SLC_ACK 0x80 257 #define SLC_FLUSHIN 0x40 258 #define SLC_FLUSHOUT 0x20 259 260 #define OLD_ENV_VAR 1 261 #define OLD_ENV_VALUE 0 262 #define NEW_ENV_VAR 0 263 #define NEW_ENV_VALUE 1 264 #define ENV_ESC 2 265 #define ENV_USERVAR 3 266 267 /* 268 * AUTHENTICATION suboptions 269 */ 270 271 /* 272 * Who is authenticating who ... 273 */ 274 #define AUTH_WHO_CLIENT 0 /* Client authenticating server */ 275 #define AUTH_WHO_SERVER 1 /* Server authenticating client */ 276 #define AUTH_WHO_MASK 1 277 278 #define AUTHTYPE_NULL 0 279 #define AUTHTYPE_KERBEROS_V4 1 280 #define AUTHTYPE_KERBEROS_V5 2 281 #define AUTHTYPE_SPX 3 282 #define AUTHTYPE_MINK 4 283 #define AUTHTYPE_CNT 5 284 285 #define AUTHTYPE_TEST 99 286 287 #ifdef AUTH_NAMES 288 const char *authtype_names[] = { 289 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 0, 290 }; 291 #else 292 extern char *authtype_names[]; 293 #endif 294 295 #define AUTHTYPE_NAME_OK(x) ((unsigned int)(x) < AUTHTYPE_CNT) 296 #define AUTHTYPE_NAME(x) authtype_names[x] 297 298 /* 299 * ENCRYPTion suboptions 300 */ 301 #define ENCRYPT_IS 0 /* I pick encryption type ... */ 302 #define ENCRYPT_SUPPORT 1 /* I support encryption types ... */ 303 #define ENCRYPT_REPLY 2 /* Initial setup response */ 304 #define ENCRYPT_START 3 /* Am starting to send encrypted */ 305 #define ENCRYPT_END 4 /* Am ending encrypted */ 306 #define ENCRYPT_REQSTART 5 /* Request you start encrypting */ 307 #define ENCRYPT_REQEND 6 /* Request you send encrypting */ 308 #define ENCRYPT_ENC_KEYID 7 309 #define ENCRYPT_DEC_KEYID 8 310 #define ENCRYPT_CNT 9 311 312 #define ENCTYPE_ANY 0 313 #define ENCTYPE_DES_CFB64 1 314 #define ENCTYPE_DES_OFB64 2 315 #define ENCTYPE_CNT 3 316 317 #ifdef ENCRYPT_NAMES 318 const char *encrypt_names[] = { 319 "IS", "SUPPORT", "REPLY", "START", "END", 320 "REQUEST-START", "REQUEST-END", "ENC-KEYID", "DEC-KEYID", 321 0, 322 }; 323 const char *enctype_names[] = { 324 "ANY", "DES_CFB64", "DES_OFB64", 0, 325 }; 326 #else 327 extern char *encrypt_names[]; 328 extern char *enctype_names[]; 329 #endif 330 331 #define ENCRYPT_NAME_OK(x) ((unsigned int)(x) < ENCRYPT_CNT) 332 #define ENCRYPT_NAME(x) encrypt_names[x] 333 334 #define ENCTYPE_NAME_OK(x) ((unsigned int)(x) < ENCTYPE_CNT) 335 #define ENCTYPE_NAME(x) enctype_names[x] 336 337 /* normal */ 338 static const char *cmds[] = { 339 "IS", "SEND", "INFO", 340 }; 341 342 /* 37: Authentication */ 343 static const char *authcmd[] = { 344 "IS", "SEND", "REPLY", "NAME", 345 }; 346 static const char *authtype[] = { 347 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 348 "SRP", "RSA", "SSL", NULL, NULL, 349 "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS", 350 "NTLM", 351 }; 352 353 /* 38: Encryption */ 354 static const char *enccmd[] = { 355 "IS", "SUPPORT", "REPLY", "START", "END", 356 "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID", 357 }; 358 static const char *enctype[] = { 359 "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64", 360 NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64", 361 }; 362 363 #define STR_OR_ID(x, tab) \ 364 (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x)) 365 366 static char * 367 numstr(int x) 368 { 369 static char buf[20]; 370 371 snprintf(buf, sizeof(buf), "%#x", x); 372 return buf; 373 } 374 375 /* sp points to IAC byte */ 376 static int 377 telnet_parse(netdissect_options *ndo, const u_char *sp, u_int length, int print) 378 { 379 int i, x; 380 u_int c; 381 const u_char *osp, *p; 382 #define FETCH(c, sp, length) \ 383 do { \ 384 if (length < 1) \ 385 goto pktend; \ 386 c = GET_U_1(sp); \ 387 sp++; \ 388 length--; \ 389 } while (0) 390 391 osp = sp; 392 393 FETCH(c, sp, length); 394 if (c != IAC) 395 goto pktend; 396 FETCH(c, sp, length); 397 if (c == IAC) { /* <IAC><IAC>! */ 398 if (print) 399 ND_PRINT("IAC IAC"); 400 goto done; 401 } 402 403 i = c - TELCMD_FIRST; 404 if (i < 0 || i > IAC - TELCMD_FIRST) 405 goto pktend; 406 407 switch (c) { 408 case DONT: 409 case DO: 410 case WONT: 411 case WILL: 412 case SB: 413 /* DONT/DO/WONT/WILL x */ 414 FETCH(x, sp, length); 415 if (x >= 0 && x < NTELOPTS) { 416 if (print) 417 ND_PRINT("%s %s", telcmds[i], telopts[x]); 418 } else { 419 if (print) 420 ND_PRINT("%s %#x", telcmds[i], x); 421 } 422 if (c != SB) 423 break; 424 /* IAC SB .... IAC SE */ 425 p = sp; 426 while (length > (u_int)(p + 1 - sp)) { 427 if (GET_U_1(p) == IAC && GET_U_1(p + 1) == SE) 428 break; 429 p++; 430 } 431 if (GET_U_1(p) != IAC) 432 goto pktend; 433 434 switch (x) { 435 case TELOPT_AUTHENTICATION: 436 if (p <= sp) 437 break; 438 FETCH(c, sp, length); 439 if (print) 440 ND_PRINT(" %s", STR_OR_ID(c, authcmd)); 441 if (p <= sp) 442 break; 443 FETCH(c, sp, length); 444 if (print) 445 ND_PRINT(" %s", STR_OR_ID(c, authtype)); 446 break; 447 case TELOPT_ENCRYPT: 448 if (p <= sp) 449 break; 450 FETCH(c, sp, length); 451 if (print) 452 ND_PRINT(" %s", STR_OR_ID(c, enccmd)); 453 if (p <= sp) 454 break; 455 FETCH(c, sp, length); 456 if (print) 457 ND_PRINT(" %s", STR_OR_ID(c, enctype)); 458 break; 459 default: 460 if (p <= sp) 461 break; 462 FETCH(c, sp, length); 463 if (print) 464 ND_PRINT(" %s", STR_OR_ID(c, cmds)); 465 break; 466 } 467 while (p > sp) { 468 FETCH(x, sp, length); 469 if (print) 470 ND_PRINT(" %#x", x); 471 } 472 /* terminating IAC SE */ 473 if (print) 474 ND_PRINT(" SE"); 475 sp += 2; 476 break; 477 default: 478 if (print) 479 ND_PRINT("%s", telcmds[i]); 480 goto done; 481 } 482 483 done: 484 return (int)(sp - osp); 485 486 pktend: 487 return -1; 488 #undef FETCH 489 } 490 491 void 492 telnet_print(netdissect_options *ndo, const u_char *sp, u_int length) 493 { 494 int first = 1; 495 const u_char *osp; 496 int l; 497 498 ndo->ndo_protocol = "telnet"; 499 osp = sp; 500 501 while (length > 0 && GET_U_1(sp) == IAC) { 502 /* 503 * Parse the Telnet command without printing it, 504 * to determine its length. 505 */ 506 l = telnet_parse(ndo, sp, length, 0); 507 if (l < 0) 508 break; 509 510 /* 511 * now print it 512 */ 513 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) { 514 if (first) 515 ND_PRINT("\nTelnet:"); 516 hex_print_with_offset(ndo, "\n", sp, l, (u_int)(sp - osp)); 517 if (l > 8) 518 ND_PRINT("\n\t\t\t\t"); 519 else 520 ND_PRINT("%*s\t", (8 - l) * 3, ""); 521 } else 522 ND_PRINT("%s", (first) ? " [telnet " : ", "); 523 524 (void)telnet_parse(ndo, sp, length, 1); 525 first = 0; 526 527 sp += l; 528 length -= l; 529 } 530 if (!first) { 531 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) 532 ND_PRINT("\n"); 533 else 534 ND_PRINT("]"); 535 } 536 } 537