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
90 static 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)
147 static 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
239 const char *slc_names[] = {
240 SLC_NAMELIST
241 };
242 #else
243 extern 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
292 const char *authtype_names[] = {
293 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK", 0,
294 };
295 #else
296 extern 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
322 const char *encrypt_names[] = {
323 "IS", "SUPPORT", "REPLY", "START", "END",
324 "REQUEST-START", "REQUEST-END", "ENC-KEYID", "DEC-KEYID",
325 0,
326 };
327 const char *enctype_names[] = {
328 "ANY", "DES_CFB64", "DES_OFB64", 0,
329 };
330 #else
331 extern char *encrypt_names[];
332 extern 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 */
342 static const char *cmds[] = {
343 "IS", "SEND", "INFO",
344 };
345
346 /* 37: Authentication */
347 static const char *authcmd[] = {
348 "IS", "SEND", "REPLY", "NAME",
349 };
350 static 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 */
358 static const char *enccmd[] = {
359 "IS", "SUPPORT", "REPLY", "START", "END",
360 "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
361 };
362 static 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
370 static char *
numstr(int x)371 numstr(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 */
380 static int
telnet_parse(netdissect_options * ndo,const u_char * sp,u_int length,int print)381 telnet_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
487 done:
488 return (int)(sp - osp);
489
490 pktend:
491 return -1;
492 #undef FETCH
493 }
494
495 void
telnet_print(netdissect_options * ndo,const u_char * sp,u_int length)496 telnet_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