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
25 #ifndef lint
26 static const char rcsid[] _U_ =
27 "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.75 2007-04-13 09:43:11 hannes Exp $";
28 #endif
29
30 #ifdef HAVE_CONFIG_H
31 #include "config.h"
32 #endif
33
34 #include <tcpdump-stdinc.h>
35
36 #include <stdio.h>
37 #include <string.h>
38
39 #include "interface.h"
40 #include "addrtoname.h"
41 #include "extract.h" /* must come after interface.h */
42
43 #include "llc.h"
44 #include "ethertype.h"
45 #include "oui.h"
46
47 static const struct tok llc_values[] = {
48 { LLCSAP_NULL, "Null" },
49 { LLCSAP_GLOBAL, "Global" },
50 { LLCSAP_8021B_I, "802.1B I" },
51 { LLCSAP_8021B_G, "802.1B G" },
52 { LLCSAP_IP, "IP" },
53 { LLCSAP_SNA, "SNA" },
54 { LLCSAP_PROWAYNM, "ProWay NM" },
55 { LLCSAP_8021D, "STP" },
56 { LLCSAP_RS511, "RS511" },
57 { LLCSAP_ISO8208, "ISO8208" },
58 { LLCSAP_PROWAY, "ProWay" },
59 { LLCSAP_SNAP, "SNAP" },
60 { LLCSAP_IPX, "IPX" },
61 { LLCSAP_NETBEUI, "NetBeui" },
62 { LLCSAP_ISONS, "OSI" },
63 { 0, NULL },
64 };
65
66 static const struct tok llc_cmd_values[] = {
67 { LLC_UI, "ui" },
68 { LLC_TEST, "test" },
69 { LLC_XID, "xid" },
70 { LLC_UA, "ua" },
71 { LLC_DISC, "disc" },
72 { LLC_DM, "dm" },
73 { LLC_SABME, "sabme" },
74 { LLC_FRMR, "frmr" },
75 { 0, NULL }
76 };
77
78 static const struct tok llc_flag_values[] = {
79 { 0, "Command" },
80 { LLC_GSAP, "Response" },
81 { LLC_U_POLL, "Poll" },
82 { LLC_GSAP|LLC_U_POLL, "Final" },
83 { LLC_IS_POLL, "Poll" },
84 { LLC_GSAP|LLC_IS_POLL, "Final" },
85 { 0, NULL }
86 };
87
88
89 static const struct tok llc_ig_flag_values[] = {
90 { 0, "Individual" },
91 { LLC_IG, "Group" },
92 { 0, NULL }
93 };
94
95
96 static const struct tok llc_supervisory_values[] = {
97 { 0, "Receiver Ready" },
98 { 1, "Receiver not Ready" },
99 { 2, "Reject" },
100 { 0, NULL }
101 };
102
103
104 static const struct tok cisco_values[] = {
105 { PID_CISCO_CDP, "CDP" },
106 { PID_CISCO_VTP, "VTP" },
107 { PID_CISCO_DTP, "DTP" },
108 { PID_CISCO_UDLD, "UDLD" },
109 { PID_CISCO_PVST, "PVST" },
110 { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
111 { 0, NULL }
112 };
113
114 static const struct tok bridged_values[] = {
115 { PID_RFC2684_ETH_FCS, "Ethernet + FCS" },
116 { PID_RFC2684_ETH_NOFCS, "Ethernet w/o FCS" },
117 { PID_RFC2684_802_4_FCS, "802.4 + FCS" },
118 { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
119 { PID_RFC2684_802_5_FCS, "Token Ring + FCS" },
120 { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
121 { PID_RFC2684_FDDI_FCS, "FDDI + FCS" },
122 { PID_RFC2684_FDDI_NOFCS, "FDDI w/o FCS" },
123 { PID_RFC2684_802_6_FCS, "802.6 + FCS" },
124 { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
125 { PID_RFC2684_BPDU, "BPDU" },
126 { 0, NULL },
127 };
128
129 static const struct tok null_values[] = {
130 { 0, NULL }
131 };
132
133 struct oui_tok {
134 u_int32_t oui;
135 const struct tok *tok;
136 };
137
138 static const struct oui_tok oui_to_tok[] = {
139 { OUI_ENCAP_ETHER, ethertype_values },
140 { OUI_CISCO_90, ethertype_values }, /* uses some Ethertype values */
141 { OUI_APPLETALK, ethertype_values }, /* uses some Ethertype values */
142 { OUI_CISCO, cisco_values },
143 { OUI_RFC2684, bridged_values }, /* bridged, RFC 2427 FR or RFC 2864 ATM */
144 { 0, NULL }
145 };
146
147 /*
148 * Returns non-zero IFF it succeeds in printing the header
149 */
150 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)151 llc_print(const u_char *p, u_int length, u_int caplen,
152 const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
153 {
154 u_int8_t dsap_field, dsap, ssap_field, ssap;
155 u_int16_t control;
156 int is_u;
157 register int ret;
158
159 *extracted_ethertype = 0;
160
161 if (caplen < 3) {
162 (void)printf("[|llc]");
163 default_print((u_char *)p, caplen);
164 return(0);
165 }
166
167 dsap_field = *p;
168 ssap_field = *(p + 1);
169
170 /*
171 * OK, what type of LLC frame is this? The length
172 * of the control field depends on that - I frames
173 * have a two-byte control field, and U frames have
174 * a one-byte control field.
175 */
176 control = *(p + 2);
177 if ((control & LLC_U_FMT) == LLC_U_FMT) {
178 /*
179 * U frame.
180 */
181 is_u = 1;
182 } else {
183 /*
184 * The control field in I and S frames is
185 * 2 bytes...
186 */
187 if (caplen < 4) {
188 (void)printf("[|llc]");
189 default_print((u_char *)p, caplen);
190 return(0);
191 }
192
193 /*
194 * ...and is little-endian.
195 */
196 control = EXTRACT_LE_16BITS(p + 2);
197 is_u = 0;
198 }
199
200 if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
201 /*
202 * This is an Ethernet_802.3 IPX frame; it has an
203 * 802.3 header (i.e., an Ethernet header where the
204 * type/length field is <= ETHERMTU, i.e. it's a length
205 * field, not a type field), but has no 802.2 header -
206 * the IPX packet starts right after the Ethernet header,
207 * with a signature of two bytes of 0xFF (which is
208 * LLCSAP_GLOBAL).
209 *
210 * (It might also have been an Ethernet_802.3 IPX at
211 * one time, but got bridged onto another network,
212 * such as an 802.11 network; this has appeared in at
213 * least one capture file.)
214 */
215
216 if (eflag)
217 printf("IPX 802.3: ");
218
219 ipx_print(p, length);
220 return (1);
221 }
222
223 dsap = dsap_field & ~LLC_IG;
224 ssap = ssap_field & ~LLC_GSAP;
225
226 if (eflag) {
227 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
228 tok2str(llc_values, "Unknown", dsap),
229 dsap,
230 tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
231 tok2str(llc_values, "Unknown", ssap),
232 ssap,
233 tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
234
235 if (is_u) {
236 printf(", ctrl 0x%02x: ", control);
237 } else {
238 printf(", ctrl 0x%04x: ", control);
239 }
240 }
241
242 if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
243 control == LLC_UI) {
244 stp_print(p+3, length-3);
245 return (1);
246 }
247
248 if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
249 control == LLC_UI) {
250 ip_print(gndo, p+4, length-4);
251 return (1);
252 }
253
254 if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
255 control == LLC_UI) {
256 /*
257 * This is an Ethernet_802.2 IPX frame, with an 802.3
258 * header and an 802.2 LLC header with the source and
259 * destination SAPs being the IPX SAP.
260 *
261 * Skip DSAP, LSAP, and control field.
262 */
263 if (eflag)
264 printf("IPX 802.2: ");
265
266 ipx_print(p+3, length-3);
267 return (1);
268 }
269
270 #ifdef TCPDUMP_DO_SMB
271 if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
272 && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
273 /*
274 * we don't actually have a full netbeui parser yet, but the
275 * smb parser can handle many smb-in-netbeui packets, which
276 * is very useful, so we call that
277 *
278 * We don't call it for S frames, however, just I frames
279 * (which are frames that don't have the low-order bit,
280 * LLC_S_FMT, set in the first byte of the control field)
281 * and UI frames (whose control field is just 3, LLC_U_FMT).
282 */
283
284 /*
285 * Skip the LLC header.
286 */
287 if (is_u) {
288 p += 3;
289 length -= 3;
290 caplen -= 3;
291 } else {
292 p += 4;
293 length -= 4;
294 caplen -= 4;
295 }
296 netbeui_print(control, p, length);
297 return (1);
298 }
299 #endif
300 if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
301 && control == LLC_UI) {
302 isoclns_print(p + 3, length - 3, caplen - 3);
303 return (1);
304 }
305
306 if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
307 && control == LLC_UI) {
308 /*
309 * XXX - what *is* the right bridge pad value here?
310 * Does anybody ever bridge one form of LAN traffic
311 * over a networking type that uses 802.2 LLC?
312 */
313 ret = snap_print(p+3, length-3, caplen-3, 2);
314 if (ret)
315 return (ret);
316 }
317
318 if (!eflag) {
319 if (ssap == dsap) {
320 if (esrc == NULL || edst == NULL)
321 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
322 else
323 (void)printf("%s > %s %s ",
324 etheraddr_string(esrc),
325 etheraddr_string(edst),
326 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
327 } else {
328 if (esrc == NULL || edst == NULL)
329 (void)printf("%s > %s ",
330 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
331 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
332 else
333 (void)printf("%s %s > %s %s ",
334 etheraddr_string(esrc),
335 tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
336 etheraddr_string(edst),
337 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
338 }
339 }
340
341 if (is_u) {
342 printf("Unnumbered, %s, Flags [%s], length %u",
343 tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
344 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
345 length);
346
347 p += 3;
348 length -= 3;
349 caplen -= 3;
350
351 if ((control & ~LLC_U_POLL) == LLC_XID) {
352 if (*p == LLC_XID_FI) {
353 printf(": %02x %02x", p[1], p[2]);
354 p += 3;
355 length -= 3;
356 caplen -= 3;
357 }
358 }
359 } else {
360 if ((control & LLC_S_FMT) == LLC_S_FMT) {
361 (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
362 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
363 LLC_IS_NR(control),
364 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
365 length);
366 } else {
367 (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
368 LLC_I_NS(control),
369 LLC_IS_NR(control),
370 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
371 length);
372 }
373 p += 4;
374 length -= 4;
375 caplen -= 4;
376 }
377 return(1);
378 }
379
380 int
snap_print(const u_char * p,u_int length,u_int caplen,u_int bridge_pad)381 snap_print(const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
382 {
383 u_int32_t orgcode;
384 register u_short et;
385 register int ret;
386
387 TCHECK2(*p, 5);
388 orgcode = EXTRACT_24BITS(p);
389 et = EXTRACT_16BITS(p + 3);
390
391 if (eflag) {
392 const struct tok *tok = null_values;
393 const struct oui_tok *otp;
394
395 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
396 if (otp->oui == orgcode) {
397 tok = otp->tok;
398 break;
399 }
400 }
401 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
402 tok2str(oui_values, "Unknown", orgcode),
403 orgcode,
404 (orgcode == 0x000000 ? "ethertype" : "pid"),
405 tok2str(tok, "Unknown", et),
406 et);
407 }
408 p += 5;
409 length -= 5;
410 caplen -= 5;
411
412 switch (orgcode) {
413 case OUI_ENCAP_ETHER:
414 case OUI_CISCO_90:
415 /*
416 * This is an encapsulated Ethernet packet,
417 * or a packet bridged by some piece of
418 * Cisco hardware; the protocol ID is
419 * an Ethernet protocol type.
420 */
421 ret = ethertype_print(gndo, et, p, length, caplen);
422 if (ret)
423 return (ret);
424 break;
425
426 case OUI_APPLETALK:
427 if (et == ETHERTYPE_ATALK) {
428 /*
429 * No, I have no idea why Apple used one
430 * of their own OUIs, rather than
431 * 0x000000, and an Ethernet packet
432 * type, for Appletalk data packets,
433 * but used 0x000000 and an Ethernet
434 * packet type for AARP packets.
435 */
436 ret = ethertype_print(gndo, et, p, length, caplen);
437 if (ret)
438 return (ret);
439 }
440 break;
441
442 case OUI_CISCO:
443 switch (et) {
444 case PID_CISCO_CDP:
445 cdp_print(p, length, caplen);
446 return (1);
447 case PID_CISCO_DTP:
448 dtp_print(p, length);
449 return (1);
450 case PID_CISCO_UDLD:
451 udld_print(p, length);
452 return (1);
453 case PID_CISCO_VTP:
454 vtp_print(p, length);
455 return (1);
456 case PID_CISCO_PVST:
457 case PID_CISCO_VLANBRIDGE:
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