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
28static 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
49static 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
68static 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
80static 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
91static const struct tok llc_ig_flag_values[] = {
92        { 0, "Individual" },
93        { LLC_IG, "Group" },
94	{ 0, NULL }
95};
96
97
98static const struct tok llc_supervisory_values[] = {
99        { 0, "Receiver Ready" },
100        { 1, "Receiver not Ready" },
101        { 2, "Reject" },
102	{ 0,             NULL }
103};
104
105
106static 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
115static 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
130static const struct tok null_values[] = {
131	{ 0,             NULL }
132};
133
134struct oui_tok {
135	u_int32_t	oui;
136	const struct tok *tok;
137};
138
139static 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 */
151int
152llc_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
381int
382snap_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
536trunc:
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