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#include "extract.h" 60 61 62/* NetBSD: telnet.h,v 1.9 2001/06/11 01:50:50 wiz Exp */ 63 64/* 65 * Definitions for the TELNET protocol. 66 */ 67#define IAC 255 /* interpret as command: */ 68#define DONT 254 /* you are not to use option */ 69#define DO 253 /* please, you use option */ 70#define WONT 252 /* I won't use option */ 71#define WILL 251 /* I will use option */ 72#define SB 250 /* interpret as subnegotiation */ 73#define GA 249 /* you may reverse the line */ 74#define EL 248 /* erase the current line */ 75#define EC 247 /* erase the current character */ 76#define AYT 246 /* are you there */ 77#define AO 245 /* abort output--but let prog finish */ 78#define IP 244 /* interrupt process--permanently */ 79#define BREAK 243 /* break */ 80#define DM 242 /* data mark--for connect. cleaning */ 81#define NOP 241 /* nop */ 82#define SE 240 /* end sub negotiation */ 83#define EOR 239 /* end of record (transparent mode) */ 84#define ABORT 238 /* Abort process */ 85#define SUSP 237 /* Suspend process */ 86#define xEOF 236 /* End of file: EOF is already used... */ 87 88#define SYNCH 242 /* for telfunc calls */ 89 90static const char *telcmds[] = { 91 "EOF", "SUSP", "ABORT", "EOR", 92 "SE", "NOP", "DMARK", "BRK", "IP", "AO", "AYT", "EC", 93 "EL", "GA", "SB", "WILL", "WONT", "DO", "DONT", "IAC", 0, 94}; 95 96#define TELCMD_FIRST xEOF 97#define TELCMD_LAST IAC 98#define TELCMD_OK(x) ((unsigned int)(x) <= TELCMD_LAST && \ 99 (unsigned int)(x) >= TELCMD_FIRST) 100#define TELCMD(x) telcmds[(x)-TELCMD_FIRST] 101 102/* telnet options */ 103#define TELOPT_BINARY 0 /* 8-bit data path */ 104#define TELOPT_ECHO 1 /* echo */ 105#define TELOPT_RCP 2 /* prepare to reconnect */ 106#define TELOPT_SGA 3 /* suppress go ahead */ 107#define TELOPT_NAMS 4 /* approximate message size */ 108#define TELOPT_STATUS 5 /* give status */ 109#define TELOPT_TM 6 /* timing mark */ 110#define TELOPT_RCTE 7 /* remote controlled transmission and echo */ 111#define TELOPT_NAOL 8 /* negotiate about output line width */ 112#define TELOPT_NAOP 9 /* negotiate about output page size */ 113#define TELOPT_NAOCRD 10 /* negotiate about CR disposition */ 114#define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */ 115#define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */ 116#define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */ 117#define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */ 118#define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */ 119#define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */ 120#define TELOPT_XASCII 17 /* extended ascic character set */ 121#define TELOPT_LOGOUT 18 /* force logout */ 122#define TELOPT_BM 19 /* byte macro */ 123#define TELOPT_DET 20 /* data entry terminal */ 124#define TELOPT_SUPDUP 21 /* supdup protocol */ 125#define TELOPT_SUPDUPOUTPUT 22 /* supdup output */ 126#define TELOPT_SNDLOC 23 /* send location */ 127#define TELOPT_TTYPE 24 /* terminal type */ 128#define TELOPT_EOR 25 /* end or record */ 129#define TELOPT_TUID 26 /* TACACS user identification */ 130#define TELOPT_OUTMRK 27 /* output marking */ 131#define TELOPT_TTYLOC 28 /* terminal location number */ 132#define TELOPT_3270REGIME 29 /* 3270 regime */ 133#define TELOPT_X3PAD 30 /* X.3 PAD */ 134#define TELOPT_NAWS 31 /* window size */ 135#define TELOPT_TSPEED 32 /* terminal speed */ 136#define TELOPT_LFLOW 33 /* remote flow control */ 137#define TELOPT_LINEMODE 34 /* Linemode option */ 138#define TELOPT_XDISPLOC 35 /* X Display Location */ 139#define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */ 140#define TELOPT_AUTHENTICATION 37/* Authenticate */ 141#define TELOPT_ENCRYPT 38 /* Encryption option */ 142#define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */ 143#define TELOPT_EXOPL 255 /* extended-options-list */ 144 145 146#define NTELOPTS (1+TELOPT_NEW_ENVIRON) 147static const char *telopts[NTELOPTS+1] = { 148 "BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME", 149 "STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP", 150 "NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS", 151 "NAOVTD", "NAOLFD", "EXTEND ASCII", "LOGOUT", "BYTE MACRO", 152 "DATA ENTRY TERMINAL", "SUPDUP", "SUPDUP OUTPUT", 153 "SEND LOCATION", "TERMINAL TYPE", "END OF RECORD", 154 "TACACS UID", "OUTPUT MARKING", "TTYLOC", 155 "3270 REGIME", "X.3 PAD", "NAWS", "TSPEED", "LFLOW", 156 "LINEMODE", "XDISPLOC", "OLD-ENVIRON", "AUTHENTICATION", 157 "ENCRYPT", "NEW-ENVIRON", 158 0, 159}; 160#define TELOPT_FIRST TELOPT_BINARY 161#define TELOPT_LAST TELOPT_NEW_ENVIRON 162#define TELOPT_OK(x) ((unsigned int)(x) <= TELOPT_LAST) 163#define TELOPT(x) telopts[(x)-TELOPT_FIRST] 164 165/* sub-option qualifiers */ 166#define TELQUAL_IS 0 /* option is... */ 167#define TELQUAL_SEND 1 /* send option */ 168#define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */ 169#define TELQUAL_REPLY 2 /* AUTHENTICATION: client version of IS */ 170#define TELQUAL_NAME 3 /* AUTHENTICATION: client version of IS */ 171 172#define LFLOW_OFF 0 /* Disable remote flow control */ 173#define LFLOW_ON 1 /* Enable remote flow control */ 174#define LFLOW_RESTART_ANY 2 /* Restart output on any char */ 175#define LFLOW_RESTART_XON 3 /* Restart output only on XON */ 176 177/* 178 * LINEMODE suboptions 179 */ 180 181#define LM_MODE 1 182#define LM_FORWARDMASK 2 183#define LM_SLC 3 184 185#define MODE_EDIT 0x01 186#define MODE_TRAPSIG 0x02 187#define MODE_ACK 0x04 188#define MODE_SOFT_TAB 0x08 189#define MODE_LIT_ECHO 0x10 190 191#define MODE_MASK 0x1f 192 193#define SLC_SYNCH 1 194#define SLC_BRK 2 195#define SLC_IP 3 196#define SLC_AO 4 197#define SLC_AYT 5 198#define SLC_EOR 6 199#define SLC_ABORT 7 200#define SLC_EOF 8 201#define SLC_SUSP 9 202#define SLC_EC 10 203#define SLC_EL 11 204#define SLC_EW 12 205#define SLC_RP 13 206#define SLC_LNEXT 14 207#define SLC_XON 15 208#define SLC_XOFF 16 209#define SLC_FORW1 17 210#define SLC_FORW2 18 211#define SLC_MCL 19 212#define SLC_MCR 20 213#define SLC_MCWL 21 214#define SLC_MCWR 22 215#define SLC_MCBOL 23 216#define SLC_MCEOL 24 217#define SLC_INSRT 25 218#define SLC_OVER 26 219#define SLC_ECR 27 220#define SLC_EWR 28 221#define SLC_EBOL 29 222#define SLC_EEOL 30 223 224#define NSLC 30 225 226/* 227 * For backwards compatibility, we define SLC_NAMES to be the 228 * list of names if SLC_NAMES is not defined. 229 */ 230#define SLC_NAMELIST "0", "SYNCH", "BRK", "IP", "AO", "AYT", "EOR", \ 231 "ABORT", "EOF", "SUSP", "EC", "EL", "EW", "RP", \ 232 "LNEXT", "XON", "XOFF", "FORW1", "FORW2", \ 233 "MCL", "MCR", "MCWL", "MCWR", "MCBOL", \ 234 "MCEOL", "INSRT", "OVER", "ECR", "EWR", \ 235 "EBOL", "EEOL", \ 236 0, 237 238#ifdef SLC_NAMES 239const char *slc_names[] = { 240 SLC_NAMELIST 241}; 242#else 243extern char *slc_names[]; 244#define SLC_NAMES SLC_NAMELIST 245#endif 246 247#define SLC_NAME_OK(x) ((unsigned int)(x) <= NSLC) 248#define SLC_NAME(x) slc_names[x] 249 250#define SLC_NOSUPPORT 0 251#define SLC_CANTCHANGE 1 252#define SLC_VARIABLE 2 253#define SLC_DEFAULT 3 254#define SLC_LEVELBITS 0x03 255 256#define SLC_FUNC 0 257#define SLC_FLAGS 1 258#define SLC_VALUE 2 259 260#define SLC_ACK 0x80 261#define SLC_FLUSHIN 0x40 262#define SLC_FLUSHOUT 0x20 263 264#define OLD_ENV_VAR 1 265#define OLD_ENV_VALUE 0 266#define NEW_ENV_VAR 0 267#define NEW_ENV_VALUE 1 268#define ENV_ESC 2 269#define ENV_USERVAR 3 270 271/* 272 * AUTHENTICATION suboptions 273 */ 274 275/* 276 * Who is authenticating who ... 277 */ 278#define AUTH_WHO_CLIENT 0 /* Client authenticating server */ 279#define AUTH_WHO_SERVER 1 /* Server authenticating client */ 280#define AUTH_WHO_MASK 1 281 282#define AUTHTYPE_NULL 0 283#define AUTHTYPE_KERBEROS_V4 1 284#define AUTHTYPE_KERBEROS_V5 2 285#define AUTHTYPE_SPX 3 286#define AUTHTYPE_MINK 4 287#define AUTHTYPE_CNT 5 288 289#define AUTHTYPE_TEST 99 290 291#ifdef AUTH_NAMES 292const char *authtype_names[] = { 293 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 0, 294}; 295#else 296extern char *authtype_names[]; 297#endif 298 299#define AUTHTYPE_NAME_OK(x) ((unsigned int)(x) < AUTHTYPE_CNT) 300#define AUTHTYPE_NAME(x) authtype_names[x] 301 302/* 303 * ENCRYPTion suboptions 304 */ 305#define ENCRYPT_IS 0 /* I pick encryption type ... */ 306#define ENCRYPT_SUPPORT 1 /* I support encryption types ... */ 307#define ENCRYPT_REPLY 2 /* Initial setup response */ 308#define ENCRYPT_START 3 /* Am starting to send encrypted */ 309#define ENCRYPT_END 4 /* Am ending encrypted */ 310#define ENCRYPT_REQSTART 5 /* Request you start encrypting */ 311#define ENCRYPT_REQEND 6 /* Request you send encrypting */ 312#define ENCRYPT_ENC_KEYID 7 313#define ENCRYPT_DEC_KEYID 8 314#define ENCRYPT_CNT 9 315 316#define ENCTYPE_ANY 0 317#define ENCTYPE_DES_CFB64 1 318#define ENCTYPE_DES_OFB64 2 319#define ENCTYPE_CNT 3 320 321#ifdef ENCRYPT_NAMES 322const char *encrypt_names[] = { 323 "IS", "SUPPORT", "REPLY", "START", "END", 324 "REQUEST-START", "REQUEST-END", "ENC-KEYID", "DEC-KEYID", 325 0, 326}; 327const char *enctype_names[] = { 328 "ANY", "DES_CFB64", "DES_OFB64", 0, 329}; 330#else 331extern char *encrypt_names[]; 332extern char *enctype_names[]; 333#endif 334 335#define ENCRYPT_NAME_OK(x) ((unsigned int)(x) < ENCRYPT_CNT) 336#define ENCRYPT_NAME(x) encrypt_names[x] 337 338#define ENCTYPE_NAME_OK(x) ((unsigned int)(x) < ENCTYPE_CNT) 339#define ENCTYPE_NAME(x) enctype_names[x] 340 341/* normal */ 342static const char *cmds[] = { 343 "IS", "SEND", "INFO", 344}; 345 346/* 37: Authentication */ 347static const char *authcmd[] = { 348 "IS", "SEND", "REPLY", "NAME", 349}; 350static const char *authtype[] = { 351 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 352 "SRP", "RSA", "SSL", NULL, NULL, 353 "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS", 354 "NTLM", 355}; 356 357/* 38: Encryption */ 358static const char *enccmd[] = { 359 "IS", "SUPPORT", "REPLY", "START", "END", 360 "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID", 361}; 362static const char *enctype[] = { 363 "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64", 364 NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64", 365}; 366 367#define STR_OR_ID(x, tab) \ 368 (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x)) 369 370static char * 371numstr(int x) 372{ 373 static char buf[20]; 374 375 snprintf(buf, sizeof(buf), "%#x", x); 376 return buf; 377} 378 379/* sp points to IAC byte */ 380static int 381telnet_parse(netdissect_options *ndo, const u_char *sp, u_int length, int print) 382{ 383 int i, x; 384 u_int c; 385 const u_char *osp, *p; 386#define FETCH(c, sp, length) \ 387 do { \ 388 if (length < 1) \ 389 goto pktend; \ 390 c = GET_U_1(sp); \ 391 sp++; \ 392 length--; \ 393 } while (0) 394 395 osp = sp; 396 397 FETCH(c, sp, length); 398 if (c != IAC) 399 goto pktend; 400 FETCH(c, sp, length); 401 if (c == IAC) { /* <IAC><IAC>! */ 402 if (print) 403 ND_PRINT("IAC IAC"); 404 goto done; 405 } 406 407 i = c - TELCMD_FIRST; 408 if (i < 0 || i > IAC - TELCMD_FIRST) 409 goto pktend; 410 411 switch (c) { 412 case DONT: 413 case DO: 414 case WONT: 415 case WILL: 416 case SB: 417 /* DONT/DO/WONT/WILL x */ 418 FETCH(x, sp, length); 419 if (x >= 0 && x < NTELOPTS) { 420 if (print) 421 ND_PRINT("%s %s", telcmds[i], telopts[x]); 422 } else { 423 if (print) 424 ND_PRINT("%s %#x", telcmds[i], x); 425 } 426 if (c != SB) 427 break; 428 /* IAC SB .... IAC SE */ 429 p = sp; 430 while (length > (u_int)(p + 1 - sp)) { 431 if (GET_U_1(p) == IAC && GET_U_1(p + 1) == SE) 432 break; 433 p++; 434 } 435 if (GET_U_1(p) != IAC) 436 goto pktend; 437 438 switch (x) { 439 case TELOPT_AUTHENTICATION: 440 if (p <= sp) 441 break; 442 FETCH(c, sp, length); 443 if (print) 444 ND_PRINT(" %s", STR_OR_ID(c, authcmd)); 445 if (p <= sp) 446 break; 447 FETCH(c, sp, length); 448 if (print) 449 ND_PRINT(" %s", STR_OR_ID(c, authtype)); 450 break; 451 case TELOPT_ENCRYPT: 452 if (p <= sp) 453 break; 454 FETCH(c, sp, length); 455 if (print) 456 ND_PRINT(" %s", STR_OR_ID(c, enccmd)); 457 if (p <= sp) 458 break; 459 FETCH(c, sp, length); 460 if (print) 461 ND_PRINT(" %s", STR_OR_ID(c, enctype)); 462 break; 463 default: 464 if (p <= sp) 465 break; 466 FETCH(c, sp, length); 467 if (print) 468 ND_PRINT(" %s", STR_OR_ID(c, cmds)); 469 break; 470 } 471 while (p > sp) { 472 FETCH(x, sp, length); 473 if (print) 474 ND_PRINT(" %#x", x); 475 } 476 /* terminating IAC SE */ 477 if (print) 478 ND_PRINT(" SE"); 479 sp += 2; 480 break; 481 default: 482 if (print) 483 ND_PRINT("%s", telcmds[i]); 484 goto done; 485 } 486 487done: 488 return (int)(sp - osp); 489 490pktend: 491 return -1; 492#undef FETCH 493} 494 495void 496telnet_print(netdissect_options *ndo, const u_char *sp, u_int length) 497{ 498 int first = 1; 499 const u_char *osp; 500 int l; 501 502 ndo->ndo_protocol = "telnet"; 503 osp = sp; 504 505 while (length > 0 && GET_U_1(sp) == IAC) { 506 /* 507 * Parse the Telnet command without printing it, 508 * to determine its length. 509 */ 510 l = telnet_parse(ndo, sp, length, 0); 511 if (l < 0) 512 break; 513 514 /* 515 * now print it 516 */ 517 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) { 518 if (first) 519 ND_PRINT("\nTelnet:"); 520 hex_print_with_offset(ndo, "\n", sp, l, (u_int)(sp - osp)); 521 if (l > 8) 522 ND_PRINT("\n\t\t\t\t"); 523 else 524 ND_PRINT("%*s\t", (8 - l) * 3, ""); 525 } else 526 ND_PRINT("%s", (first) ? " [telnet " : ", "); 527 528 (void)telnet_parse(ndo, sp, length, 1); 529 first = 0; 530 531 sp += l; 532 length -= l; 533 } 534 if (!first) { 535 if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag) 536 ND_PRINT("\n"); 537 else 538 ND_PRINT("]"); 539 } 540} 541