print-llc.c revision 172686 
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: head/contrib/tcpdump/print-llc.c 172686 2007-10-16 02:31:48Z mlaier $
25 */
26
27#ifndef lint
28static const char rcsid[] _U_ =
29    "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.61.2.10 2007/02/08 07:07:51 guy 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	{ 0,             NULL }
111};
112
113static const struct tok bridged_values[] = {
114	{ PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
115	{ PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
116	{ PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
117	{ PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
118	{ PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
119	{ PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
120	{ PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
121	{ PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
122	{ PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
123	{ PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
124	{ PID_RFC2684_BPDU,        "BPDU" },
125	{ 0,                       NULL },
126};
127
128static const struct tok null_values[] = {
129	{ 0,             NULL }
130};
131
132struct oui_tok {
133	u_int32_t	oui;
134	const struct tok *tok;
135};
136
137static const struct oui_tok oui_to_tok[] = {
138	{ OUI_ENCAP_ETHER, ethertype_values },
139	{ OUI_CISCO_90, ethertype_values },	/* uses some Ethertype values */
140	{ OUI_APPLETALK, ethertype_values },	/* uses some Ethertype values */
141	{ OUI_CISCO, cisco_values },
142	{ OUI_RFC2684, bridged_values },	/* bridged, RFC 2427 FR or RFC 2864 ATM */
143	{ 0, NULL }
144};
145
146/*
147 * Returns non-zero IFF it succeeds in printing the header
148 */
149int
150llc_print(const u_char *p, u_int length, u_int caplen,
151	  const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
152{
153	u_int8_t dsap_field, dsap, ssap_field, ssap;
154	u_int16_t control;
155	int is_u;
156	register int ret;
157
158	*extracted_ethertype = 0;
159
160	if (caplen < 3) {
161		(void)printf("[|llc]");
162		default_print((u_char *)p, caplen);
163		return(0);
164	}
165
166	dsap_field = *p;
167	ssap_field = *(p + 1);
168
169	/*
170	 * OK, what type of LLC frame is this?  The length
171	 * of the control field depends on that - I frames
172	 * have a two-byte control field, and U frames have
173	 * a one-byte control field.
174	 */
175	control = *(p + 2);
176	if ((control & LLC_U_FMT) == LLC_U_FMT) {
177		/*
178		 * U frame.
179		 */
180		is_u = 1;
181	} else {
182		/*
183		 * The control field in I and S frames is
184		 * 2 bytes...
185		 */
186		if (caplen < 4) {
187			(void)printf("[|llc]");
188			default_print((u_char *)p, caplen);
189			return(0);
190		}
191
192		/*
193		 * ...and is little-endian.
194		 */
195		control = EXTRACT_LE_16BITS(p + 2);
196		is_u = 0;
197	}
198
199	if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
200		/*
201		 * This is an Ethernet_802.3 IPX frame; it has an
202		 * 802.3 header (i.e., an Ethernet header where the
203		 * type/length field is <= ETHERMTU, i.e. it's a length
204		 * field, not a type field), but has no 802.2 header -
205		 * the IPX packet starts right after the Ethernet header,
206		 * with a signature of two bytes of 0xFF (which is
207		 * LLCSAP_GLOBAL).
208		 *
209		 * (It might also have been an Ethernet_802.3 IPX at
210		 * one time, but got bridged onto another network,
211		 * such as an 802.11 network; this has appeared in at
212		 * least one capture file.)
213		 */
214
215            if (eflag)
216		printf("IPX 802.3: ");
217
218            ipx_print(p, length);
219            return (1);
220	}
221
222	dsap = dsap_field & ~LLC_IG;
223	ssap = ssap_field & ~LLC_GSAP;
224
225	if (eflag) {
226                printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
227                       tok2str(llc_values, "Unknown", dsap),
228                       dsap,
229                       tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
230                       tok2str(llc_values, "Unknown", ssap),
231                       ssap,
232                       tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
233
234		if (is_u) {
235			printf(", ctrl 0x%02x: ", control);
236		} else {
237			printf(", ctrl 0x%04x: ", control);
238		}
239	}
240
241	if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
242	    control == LLC_UI) {
243		stp_print(p+3, length-3);
244		return (1);
245	}
246
247	if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
248	    control == LLC_UI) {
249		ip_print(gndo, p+4, length-4);
250		return (1);
251	}
252
253	if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
254	    control == LLC_UI) {
255		/*
256		 * This is an Ethernet_802.2 IPX frame, with an 802.3
257		 * header and an 802.2 LLC header with the source and
258		 * destination SAPs being the IPX SAP.
259		 *
260		 * Skip DSAP, LSAP, and control field.
261		 */
262                if (eflag)
263                        printf("IPX 802.2: ");
264
265		ipx_print(p+3, length-3);
266		return (1);
267	}
268
269#ifdef TCPDUMP_DO_SMB
270	if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
271	    && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
272		/*
273		 * we don't actually have a full netbeui parser yet, but the
274		 * smb parser can handle many smb-in-netbeui packets, which
275		 * is very useful, so we call that
276		 *
277		 * We don't call it for S frames, however, just I frames
278		 * (which are frames that don't have the low-order bit,
279		 * LLC_S_FMT, set in the first byte of the control field)
280		 * and UI frames (whose control field is just 3, LLC_U_FMT).
281		 */
282
283		/*
284		 * Skip the LLC header.
285		 */
286		if (is_u) {
287			p += 3;
288			length -= 3;
289			caplen -= 3;
290		} else {
291			p += 4;
292			length -= 4;
293			caplen -= 4;
294		}
295		netbeui_print(control, p, length);
296		return (1);
297	}
298#endif
299	if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
300	    && control == LLC_UI) {
301		isoclns_print(p + 3, length - 3, caplen - 3);
302		return (1);
303	}
304
305	if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
306	    && control == LLC_UI) {
307		/*
308		 * XXX - what *is* the right bridge pad value here?
309		 * Does anybody ever bridge one form of LAN traffic
310		 * over a networking type that uses 802.2 LLC?
311		 */
312		ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
313		    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
380int
381snap_print(const u_char *p, u_int length, u_int caplen,
382    u_short *extracted_ethertype, 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 = ether_encap_print(et, p, length, caplen,
423		    extracted_ethertype);
424		if (ret)
425			return (ret);
426		break;
427
428	case OUI_APPLETALK:
429		if (et == ETHERTYPE_ATALK) {
430			/*
431			 * No, I have no idea why Apple used one
432			 * of their own OUIs, rather than
433			 * 0x000000, and an Ethernet packet
434			 * type, for Appletalk data packets,
435			 * but used 0x000000 and an Ethernet
436			 * packet type for AARP packets.
437			 */
438			ret = ether_encap_print(et, p, length, caplen,
439			    extracted_ethertype);
440			if (ret)
441				return (ret);
442		}
443		break;
444
445	case OUI_CISCO:
446		if (et == PID_CISCO_CDP) {
447			cdp_print(p, length, caplen);
448			return (1);
449		}
450		break;
451
452	case OUI_RFC2684:
453		switch (et) {
454
455		case PID_RFC2684_ETH_FCS:
456		case PID_RFC2684_ETH_NOFCS:
457			/*
458			 * XXX - remove the last two bytes for
459			 * PID_RFC2684_ETH_FCS?
460			 */
461			/*
462			 * Skip the padding.
463			 */
464			TCHECK2(*p, bridge_pad);
465			caplen -= bridge_pad;
466			length -= bridge_pad;
467			p += bridge_pad;
468
469			/*
470			 * What remains is an Ethernet packet.
471			 */
472			ether_print(p, length, caplen);
473			return (1);
474
475		case PID_RFC2684_802_5_FCS:
476		case PID_RFC2684_802_5_NOFCS:
477			/*
478			 * XXX - remove the last two bytes for
479			 * PID_RFC2684_ETH_FCS?
480			 */
481			/*
482			 * Skip the padding, but not the Access
483			 * Control field.
484			 */
485			TCHECK2(*p, bridge_pad);
486			caplen -= bridge_pad;
487			length -= bridge_pad;
488			p += bridge_pad;
489
490			/*
491			 * What remains is an 802.5 Token Ring
492			 * packet.
493			 */
494			token_print(p, length, caplen);
495			return (1);
496
497		case PID_RFC2684_FDDI_FCS:
498		case PID_RFC2684_FDDI_NOFCS:
499			/*
500			 * XXX - remove the last two bytes for
501			 * PID_RFC2684_ETH_FCS?
502			 */
503			/*
504			 * Skip the padding.
505			 */
506			TCHECK2(*p, bridge_pad + 1);
507			caplen -= bridge_pad + 1;
508			length -= bridge_pad + 1;
509			p += bridge_pad + 1;
510
511			/*
512			 * What remains is an FDDI packet.
513			 */
514			fddi_print(p, length, caplen);
515			return (1);
516
517		case PID_RFC2684_BPDU:
518			stp_print(p, length);
519			return (1);
520		}
521	}
522	return (0);
523
524trunc:
525	(void)printf("[|snap]");
526	return (1);
527}
528
529
530/*
531 * Local Variables:
532 * c-style: whitesmith
533 * c-basic-offset: 8
534 * End:
535 */
536