1 /*
2 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * Code by Matt Thomas, Digital Equipment Corporation
22 * with an awful lot of hacking by Jeffrey Mogul, DECWRL
23 *
24 * $FreeBSD$
25 */
26
27 #ifndef lint
28 static const char rcsid[] _U_ =
29 "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.75 2007-04-13 09:43:11 hannes Exp $";
30 #endif
31
32 #ifdef HAVE_CONFIG_H
33 #include "config.h"
34 #endif
35
36 #include <tcpdump-stdinc.h>
37
38 #include <stdio.h>
39 #include <string.h>
40
41 #include "interface.h"
42 #include "addrtoname.h"
43 #include "extract.h" /* must come after interface.h */
44
45 #include "llc.h"
46 #include "ethertype.h"
47 #include "oui.h"
48
49 static struct tok llc_values[] = {
50 { LLCSAP_NULL, "Null" },
51 { LLCSAP_GLOBAL, "Global" },
52 { LLCSAP_8021B_I, "802.1B I" },
53 { LLCSAP_8021B_G, "802.1B G" },
54 { LLCSAP_IP, "IP" },
55 { LLCSAP_SNA, "SNA" },
56 { LLCSAP_PROWAYNM, "ProWay NM" },
57 { LLCSAP_8021D, "STP" },
58 { LLCSAP_RS511, "RS511" },
59 { LLCSAP_ISO8208, "ISO8208" },
60 { LLCSAP_PROWAY, "ProWay" },
61 { LLCSAP_SNAP, "SNAP" },
62 { LLCSAP_IPX, "IPX" },
63 { LLCSAP_NETBEUI, "NetBeui" },
64 { LLCSAP_ISONS, "OSI" },
65 { 0, NULL },
66 };
67
68 static struct tok llc_cmd_values[] = {
69 { LLC_UI, "ui" },
70 { LLC_TEST, "test" },
71 { LLC_XID, "xid" },
72 { LLC_UA, "ua" },
73 { LLC_DISC, "disc" },
74 { LLC_DM, "dm" },
75 { LLC_SABME, "sabme" },
76 { LLC_FRMR, "frmr" },
77 { 0, NULL }
78 };
79
80 static const struct tok llc_flag_values[] = {
81 { 0, "Command" },
82 { LLC_GSAP, "Response" },
83 { LLC_U_POLL, "Poll" },
84 { LLC_GSAP|LLC_U_POLL, "Final" },
85 { LLC_IS_POLL, "Poll" },
86 { LLC_GSAP|LLC_IS_POLL, "Final" },
87 { 0, NULL }
88 };
89
90
91 static const struct tok llc_ig_flag_values[] = {
92 { 0, "Individual" },
93 { LLC_IG, "Group" },
94 { 0, NULL }
95 };
96
97
98 static const struct tok llc_supervisory_values[] = {
99 { 0, "Receiver Ready" },
100 { 1, "Receiver not Ready" },
101 { 2, "Reject" },
102 { 0, NULL }
103 };
104
105
106 static const struct tok cisco_values[] = {
107 { PID_CISCO_CDP, "CDP" },
108 { PID_CISCO_VTP, "VTP" },
109 { PID_CISCO_DTP, "DTP" },
110 { PID_CISCO_UDLD, "UDLD" },
111 { PID_CISCO_PVST, "PVST" },
112 { 0, NULL }
113 };
114
115 static const struct tok bridged_values[] = {
116 { PID_RFC2684_ETH_FCS, "Ethernet + FCS" },
117 { PID_RFC2684_ETH_NOFCS, "Ethernet w/o FCS" },
118 { PID_RFC2684_802_4_FCS, "802.4 + FCS" },
119 { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
120 { PID_RFC2684_802_5_FCS, "Token Ring + FCS" },
121 { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
122 { PID_RFC2684_FDDI_FCS, "FDDI + FCS" },
123 { PID_RFC2684_FDDI_NOFCS, "FDDI w/o FCS" },
124 { PID_RFC2684_802_6_FCS, "802.6 + FCS" },
125 { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
126 { PID_RFC2684_BPDU, "BPDU" },
127 { 0, NULL },
128 };
129
130 static const struct tok null_values[] = {
131 { 0, NULL }
132 };
133
134 struct oui_tok {
135 u_int32_t oui;
136 const struct tok *tok;
137 };
138
139 static const struct oui_tok oui_to_tok[] = {
140 { OUI_ENCAP_ETHER, ethertype_values },
141 { OUI_CISCO_90, ethertype_values }, /* uses some Ethertype values */
142 { OUI_APPLETALK, ethertype_values }, /* uses some Ethertype values */
143 { OUI_CISCO, cisco_values },
144 { OUI_RFC2684, bridged_values }, /* bridged, RFC 2427 FR or RFC 2864 ATM */
145 { 0, NULL }
146 };
147
148 /*
149 * Returns non-zero IFF it succeeds in printing the header
150 */
151 int
llc_print(const u_char * p,u_int length,u_int caplen,const u_char * esrc,const u_char * edst,u_short * extracted_ethertype)152 llc_print(const u_char *p, u_int length, u_int caplen,
153 const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
154 {
155 u_int8_t dsap_field, dsap, ssap_field, ssap;
156 u_int16_t control;
157 int is_u;
158 register int ret;
159
160 *extracted_ethertype = 0;
161
162 if (caplen < 3) {
163 (void)printf("[|llc]");
164 default_print((u_char *)p, caplen);
165 return(0);
166 }
167
168 dsap_field = *p;
169 ssap_field = *(p + 1);
170
171 /*
172 * OK, what type of LLC frame is this? The length
173 * of the control field depends on that - I frames
174 * have a two-byte control field, and U frames have
175 * a one-byte control field.
176 */
177 control = *(p + 2);
178 if ((control & LLC_U_FMT) == LLC_U_FMT) {
179 /*
180 * U frame.
181 */
182 is_u = 1;
183 } else {
184 /*
185 * The control field in I and S frames is
186 * 2 bytes...
187 */
188 if (caplen < 4) {
189 (void)printf("[|llc]");
190 default_print((u_char *)p, caplen);
191 return(0);
192 }
193
194 /*
195 * ...and is little-endian.
196 */
197 control = EXTRACT_LE_16BITS(p + 2);
198 is_u = 0;
199 }
200
201 if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
202 /*
203 * This is an Ethernet_802.3 IPX frame; it has an
204 * 802.3 header (i.e., an Ethernet header where the
205 * type/length field is <= ETHERMTU, i.e. it's a length
206 * field, not a type field), but has no 802.2 header -
207 * the IPX packet starts right after the Ethernet header,
208 * with a signature of two bytes of 0xFF (which is
209 * LLCSAP_GLOBAL).
210 *
211 * (It might also have been an Ethernet_802.3 IPX at
212 * one time, but got bridged onto another network,
213 * such as an 802.11 network; this has appeared in at
214 * least one capture file.)
215 */
216
217 if (eflag)
218 printf("IPX 802.3: ");
219
220 ipx_print(p, length);
221 return (1);
222 }
223
224 dsap = dsap_field & ~LLC_IG;
225 ssap = ssap_field & ~LLC_GSAP;
226
227 if (eflag) {
228 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
229 tok2str(llc_values, "Unknown", dsap),
230 dsap,
231 tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
232 tok2str(llc_values, "Unknown", ssap),
233 ssap,
234 tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
235
236 if (is_u) {
237 printf(", ctrl 0x%02x: ", control);
238 } else {
239 printf(", ctrl 0x%04x: ", control);
240 }
241 }
242
243 if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
244 control == LLC_UI) {
245 stp_print(p+3, length-3);
246 return (1);
247 }
248
249 if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
250 control == LLC_UI) {
251 ip_print(gndo, p+4, length-4);
252 return (1);
253 }
254
255 if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
256 control == LLC_UI) {
257 /*
258 * This is an Ethernet_802.2 IPX frame, with an 802.3
259 * header and an 802.2 LLC header with the source and
260 * destination SAPs being the IPX SAP.
261 *
262 * Skip DSAP, LSAP, and control field.
263 */
264 if (eflag)
265 printf("IPX 802.2: ");
266
267 ipx_print(p+3, length-3);
268 return (1);
269 }
270
271 #ifdef TCPDUMP_DO_SMB
272 if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
273 && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
274 /*
275 * we don't actually have a full netbeui parser yet, but the
276 * smb parser can handle many smb-in-netbeui packets, which
277 * is very useful, so we call that
278 *
279 * We don't call it for S frames, however, just I frames
280 * (which are frames that don't have the low-order bit,
281 * LLC_S_FMT, set in the first byte of the control field)
282 * and UI frames (whose control field is just 3, LLC_U_FMT).
283 */
284
285 /*
286 * Skip the LLC header.
287 */
288 if (is_u) {
289 p += 3;
290 length -= 3;
291 caplen -= 3;
292 } else {
293 p += 4;
294 length -= 4;
295 caplen -= 4;
296 }
297 netbeui_print(control, p, length);
298 return (1);
299 }
300 #endif
301 if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
302 && control == LLC_UI) {
303 isoclns_print(p + 3, length - 3, caplen - 3);
304 return (1);
305 }
306
307 if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
308 && control == LLC_UI) {
309 /*
310 * XXX - what *is* the right bridge pad value here?
311 * Does anybody ever bridge one form of LAN traffic
312 * over a networking type that uses 802.2 LLC?
313 */
314 ret = snap_print(p+3, length-3, caplen-3, 2);
315 if (ret)
316 return (ret);
317 }
318
319 if (!eflag) {
320 if (ssap == dsap) {
321 if (esrc == NULL || edst == NULL)
322 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
323 else
324 (void)printf("%s > %s %s ",
325 etheraddr_string(esrc),
326 etheraddr_string(edst),
327 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
328 } else {
329 if (esrc == NULL || edst == NULL)
330 (void)printf("%s > %s ",
331 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
332 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
333 else
334 (void)printf("%s %s > %s %s ",
335 etheraddr_string(esrc),
336 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
337 etheraddr_string(edst),
338 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
339 }
340 }
341
342 if (is_u) {
343 printf("Unnumbered, %s, Flags [%s], length %u",
344 tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
345 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
346 length);
347
348 p += 3;
349 length -= 3;
350 caplen -= 3;
351
352 if ((control & ~LLC_U_POLL) == LLC_XID) {
353 if (*p == LLC_XID_FI) {
354 printf(": %02x %02x", p[1], p[2]);
355 p += 3;
356 length -= 3;
357 caplen -= 3;
358 }
359 }
360 } else {
361 if ((control & LLC_S_FMT) == LLC_S_FMT) {
362 (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
363 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
364 LLC_IS_NR(control),
365 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
366 length);
367 } else {
368 (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
369 LLC_I_NS(control),
370 LLC_IS_NR(control),
371 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
372 length);
373 }
374 p += 4;
375 length -= 4;
376 caplen -= 4;
377 }
378 return(1);
379 }
380
381 int
snap_print(const u_char * p,u_int length,u_int caplen,u_int bridge_pad)382 snap_print(const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
383 {
384 u_int32_t orgcode;
385 register u_short et;
386 register int ret;
387
388 TCHECK2(*p, 5);
389 orgcode = EXTRACT_24BITS(p);
390 et = EXTRACT_16BITS(p + 3);
391
392 if (eflag) {
393 const struct tok *tok = null_values;
394 const struct oui_tok *otp;
395
396 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
397 if (otp->oui == orgcode) {
398 tok = otp->tok;
399 break;
400 }
401 }
402 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
403 tok2str(oui_values, "Unknown", orgcode),
404 orgcode,
405 (orgcode == 0x000000 ? "ethertype" : "pid"),
406 tok2str(tok, "Unknown", et),
407 et);
408 }
409 p += 5;
410 length -= 5;
411 caplen -= 5;
412
413 switch (orgcode) {
414 case OUI_ENCAP_ETHER:
415 case OUI_CISCO_90:
416 /*
417 * This is an encapsulated Ethernet packet,
418 * or a packet bridged by some piece of
419 * Cisco hardware; the protocol ID is
420 * an Ethernet protocol type.
421 */
422 ret = ethertype_print(gndo, et, p, length, caplen);
423 if (ret)
424 return (ret);
425 break;
426
427 case OUI_APPLETALK:
428 if (et == ETHERTYPE_ATALK) {
429 /*
430 * No, I have no idea why Apple used one
431 * of their own OUIs, rather than
432 * 0x000000, and an Ethernet packet
433 * type, for Appletalk data packets,
434 * but used 0x000000 and an Ethernet
435 * packet type for AARP packets.
436 */
437 ret = ethertype_print(gndo, et, p, length, caplen);
438 if (ret)
439 return (ret);
440 }
441 break;
442
443 case OUI_CISCO:
444 switch (et) {
445 case PID_CISCO_CDP:
446 cdp_print(p, length, caplen);
447 return (1);
448 case PID_CISCO_DTP:
449 dtp_print(p, length);
450 return (1);
451 case PID_CISCO_UDLD:
452 udld_print(p, length);
453 return (1);
454 case PID_CISCO_VTP:
455 vtp_print(p, length);
456 return (1);
457 case PID_CISCO_PVST:
458 stp_print(p, length);
459 return (1);
460 default:
461 break;
462 }
463
464 case OUI_RFC2684:
465 switch (et) {
466
467 case PID_RFC2684_ETH_FCS:
468 case PID_RFC2684_ETH_NOFCS:
469 /*
470 * XXX - remove the last two bytes for
471 * PID_RFC2684_ETH_FCS?
472 */
473 /*
474 * Skip the padding.
475 */
476 TCHECK2(*p, bridge_pad);
477 caplen -= bridge_pad;
478 length -= bridge_pad;
479 p += bridge_pad;
480
481 /*
482 * What remains is an Ethernet packet.
483 */
484 ether_print(gndo, p, length, caplen, NULL, NULL);
485 return (1);
486
487 case PID_RFC2684_802_5_FCS:
488 case PID_RFC2684_802_5_NOFCS:
489 /*
490 * XXX - remove the last two bytes for
491 * PID_RFC2684_ETH_FCS?
492 */
493 /*
494 * Skip the padding, but not the Access
495 * Control field.
496 */
497 TCHECK2(*p, bridge_pad);
498 caplen -= bridge_pad;
499 length -= bridge_pad;
500 p += bridge_pad;
501
502 /*
503 * What remains is an 802.5 Token Ring
504 * packet.
505 */
506 token_print(p, length, caplen);
507 return (1);
508
509 case PID_RFC2684_FDDI_FCS:
510 case PID_RFC2684_FDDI_NOFCS:
511 /*
512 * XXX - remove the last two bytes for
513 * PID_RFC2684_ETH_FCS?
514 */
515 /*
516 * Skip the padding.
517 */
518 TCHECK2(*p, bridge_pad + 1);
519 caplen -= bridge_pad + 1;
520 length -= bridge_pad + 1;
521 p += bridge_pad + 1;
522
523 /*
524 * What remains is an FDDI packet.
525 */
526 fddi_print(p, length, caplen);
527 return (1);
528
529 case PID_RFC2684_BPDU:
530 stp_print(p, length);
531 return (1);
532 }
533 }
534 return (0);
535
536 trunc:
537 (void)printf("[|snap]");
538 return (1);
539 }
540
541
542 /*
543 * Local Variables:
544 * c-style: whitesmith
545 * c-basic-offset: 8
546 * End:
547 */
548