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
26static const char rcsid[] _U_ =
27    "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.61.2.10 2007/02/08 07:07:51 guy 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
47static 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
66static 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
78static 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
89static const struct tok llc_ig_flag_values[] = {
90        { 0, "Individual" },
91        { LLC_IG, "Group" },
92	{ 0, NULL }
93};
94
95
96static const struct tok llc_supervisory_values[] = {
97        { 0, "Receiver Ready" },
98        { 1, "Receiver not Ready" },
99        { 2, "Reject" },
100	{ 0,             NULL }
101};
102
103
104static const struct tok cisco_values[] = {
105	{ PID_CISCO_CDP, "CDP" },
106	{ PID_CISCO_VTP, "VTP" },
107	{ PID_CISCO_DTP, "DTP" },
108	{ 0,             NULL }
109};
110
111static const struct tok bridged_values[] = {
112	{ PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
113	{ PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
114	{ PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
115	{ PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
116	{ PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
117	{ PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
118	{ PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
119	{ PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
120	{ PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
121	{ PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
122	{ PID_RFC2684_BPDU,        "BPDU" },
123	{ 0,                       NULL },
124};
125
126static const struct tok null_values[] = {
127	{ 0,             NULL }
128};
129
130struct oui_tok {
131	u_int32_t	oui;
132	const struct tok *tok;
133};
134
135static const struct oui_tok oui_to_tok[] = {
136	{ OUI_ENCAP_ETHER, ethertype_values },
137	{ OUI_CISCO_90, ethertype_values },	/* uses some Ethertype values */
138	{ OUI_APPLETALK, ethertype_values },	/* uses some Ethertype values */
139	{ OUI_CISCO, cisco_values },
140	{ OUI_RFC2684, bridged_values },	/* bridged, RFC 2427 FR or RFC 2864 ATM */
141	{ 0, NULL }
142};
143
144/*
145 * Returns non-zero IFF it succeeds in printing the header
146 */
147int
148llc_print(const u_char *p, u_int length, u_int caplen,
149	  const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
150{
151	u_int8_t dsap_field, dsap, ssap_field, ssap;
152	u_int16_t control;
153	int is_u;
154	register int ret;
155
156	*extracted_ethertype = 0;
157
158	if (caplen < 3) {
159		(void)printf("[|llc]");
160		default_print((u_char *)p, caplen);
161		return(0);
162	}
163
164	dsap_field = *p;
165	ssap_field = *(p + 1);
166
167	/*
168	 * OK, what type of LLC frame is this?  The length
169	 * of the control field depends on that - I frames
170	 * have a two-byte control field, and U frames have
171	 * a one-byte control field.
172	 */
173	control = *(p + 2);
174	if ((control & LLC_U_FMT) == LLC_U_FMT) {
175		/*
176		 * U frame.
177		 */
178		is_u = 1;
179	} else {
180		/*
181		 * The control field in I and S frames is
182		 * 2 bytes...
183		 */
184		if (caplen < 4) {
185			(void)printf("[|llc]");
186			default_print((u_char *)p, caplen);
187			return(0);
188		}
189
190		/*
191		 * ...and is little-endian.
192		 */
193		control = EXTRACT_LE_16BITS(p + 2);
194		is_u = 0;
195	}
196
197	if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
198		/*
199		 * This is an Ethernet_802.3 IPX frame; it has an
200		 * 802.3 header (i.e., an Ethernet header where the
201		 * type/length field is <= ETHERMTU, i.e. it's a length
202		 * field, not a type field), but has no 802.2 header -
203		 * the IPX packet starts right after the Ethernet header,
204		 * with a signature of two bytes of 0xFF (which is
205		 * LLCSAP_GLOBAL).
206		 *
207		 * (It might also have been an Ethernet_802.3 IPX at
208		 * one time, but got bridged onto another network,
209		 * such as an 802.11 network; this has appeared in at
210		 * least one capture file.)
211		 */
212
213            if (eflag)
214		printf("IPX 802.3: ");
215
216            ipx_print(p, length);
217            return (1);
218	}
219
220	dsap = dsap_field & ~LLC_IG;
221	ssap = ssap_field & ~LLC_GSAP;
222
223	if (eflag) {
224                printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
225                       tok2str(llc_values, "Unknown", dsap),
226                       dsap,
227                       tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
228                       tok2str(llc_values, "Unknown", ssap),
229                       ssap,
230                       tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
231
232		if (is_u) {
233			printf(", ctrl 0x%02x: ", control);
234		} else {
235			printf(", ctrl 0x%04x: ", control);
236		}
237	}
238
239	if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
240	    control == LLC_UI) {
241		stp_print(p+3, length-3);
242		return (1);
243	}
244
245	if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
246	    control == LLC_UI) {
247		ip_print(gndo, p+4, length-4);
248		return (1);
249	}
250
251	if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
252	    control == LLC_UI) {
253		/*
254		 * This is an Ethernet_802.2 IPX frame, with an 802.3
255		 * header and an 802.2 LLC header with the source and
256		 * destination SAPs being the IPX SAP.
257		 *
258		 * Skip DSAP, LSAP, and control field.
259		 */
260                if (eflag)
261                        printf("IPX 802.2: ");
262
263		ipx_print(p+3, length-3);
264		return (1);
265	}
266
267#ifdef TCPDUMP_DO_SMB
268	if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
269	    && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
270		/*
271		 * we don't actually have a full netbeui parser yet, but the
272		 * smb parser can handle many smb-in-netbeui packets, which
273		 * is very useful, so we call that
274		 *
275		 * We don't call it for S frames, however, just I frames
276		 * (which are frames that don't have the low-order bit,
277		 * LLC_S_FMT, set in the first byte of the control field)
278		 * and UI frames (whose control field is just 3, LLC_U_FMT).
279		 */
280
281		/*
282		 * Skip the LLC header.
283		 */
284		if (is_u) {
285			p += 3;
286			length -= 3;
287			caplen -= 3;
288		} else {
289			p += 4;
290			length -= 4;
291			caplen -= 4;
292		}
293		netbeui_print(control, p, length);
294		return (1);
295	}
296#endif
297	if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
298	    && control == LLC_UI) {
299		isoclns_print(p + 3, length - 3, caplen - 3);
300		return (1);
301	}
302
303	if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
304	    && control == LLC_UI) {
305		/*
306		 * XXX - what *is* the right bridge pad value here?
307		 * Does anybody ever bridge one form of LAN traffic
308		 * over a networking type that uses 802.2 LLC?
309		 */
310		ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
311		    2);
312		if (ret)
313			return (ret);
314	}
315
316	if (!eflag) {
317		if (ssap == dsap) {
318			if (esrc == NULL || edst == NULL)
319				(void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
320			else
321				(void)printf("%s > %s %s ",
322						etheraddr_string(esrc),
323						etheraddr_string(edst),
324						tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
325		} else {
326			if (esrc == NULL || edst == NULL)
327				(void)printf("%s > %s ",
328                                        tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
329					tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
330			else
331				(void)printf("%s %s > %s %s ",
332					etheraddr_string(esrc),
333                                        tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
334					etheraddr_string(edst),
335					tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
336		}
337	}
338
339	if (is_u) {
340		printf("Unnumbered, %s, Flags [%s], length %u",
341                       tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
342                       tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
343                       length);
344
345		p += 3;
346		length -= 3;
347		caplen -= 3;
348
349		if ((control & ~LLC_U_POLL) == LLC_XID) {
350			if (*p == LLC_XID_FI) {
351				printf(": %02x %02x", p[1], p[2]);
352				p += 3;
353				length -= 3;
354				caplen -= 3;
355			}
356		}
357	} else {
358		if ((control & LLC_S_FMT) == LLC_S_FMT) {
359			(void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
360				tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
361				LLC_IS_NR(control),
362				tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
363                                length);
364		} else {
365			(void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
366				LLC_I_NS(control),
367				LLC_IS_NR(control),
368				tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
369                                length);
370		}
371		p += 4;
372		length -= 4;
373		caplen -= 4;
374	}
375	return(1);
376}
377
378int
379snap_print(const u_char *p, u_int length, u_int caplen,
380    u_short *extracted_ethertype, u_int bridge_pad)
381{
382	u_int32_t orgcode;
383	register u_short et;
384	register int ret;
385
386	TCHECK2(*p, 5);
387	orgcode = EXTRACT_24BITS(p);
388	et = EXTRACT_16BITS(p + 3);
389
390	if (eflag) {
391		const struct tok *tok = null_values;
392		const struct oui_tok *otp;
393
394		for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
395			if (otp->oui == orgcode) {
396				tok = otp->tok;
397				break;
398			}
399		}
400		(void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
401		     tok2str(oui_values, "Unknown", orgcode),
402		     orgcode,
403		     (orgcode == 0x000000 ? "ethertype" : "pid"),
404		     tok2str(tok, "Unknown", et),
405		     et);
406	}
407	p += 5;
408	length -= 5;
409	caplen -= 5;
410
411	switch (orgcode) {
412	case OUI_ENCAP_ETHER:
413	case OUI_CISCO_90:
414		/*
415		 * This is an encapsulated Ethernet packet,
416		 * or a packet bridged by some piece of
417		 * Cisco hardware; the protocol ID is
418		 * an Ethernet protocol type.
419		 */
420		ret = ether_encap_print(et, p, length, caplen,
421		    extracted_ethertype);
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 = ether_encap_print(et, p, length, caplen,
437			    extracted_ethertype);
438			if (ret)
439				return (ret);
440		}
441		break;
442
443	case OUI_CISCO:
444		if (et == PID_CISCO_CDP) {
445			cdp_print(p, length, caplen);
446			return (1);
447		}
448		break;
449
450	case OUI_RFC2684:
451		switch (et) {
452
453		case PID_RFC2684_ETH_FCS:
454		case PID_RFC2684_ETH_NOFCS:
455			/*
456			 * XXX - remove the last two bytes for
457			 * PID_RFC2684_ETH_FCS?
458			 */
459			/*
460			 * Skip the padding.
461			 */
462			TCHECK2(*p, bridge_pad);
463			caplen -= bridge_pad;
464			length -= bridge_pad;
465			p += bridge_pad;
466
467			/*
468			 * What remains is an Ethernet packet.
469			 */
470			ether_print(p, length, caplen);
471			return (1);
472
473		case PID_RFC2684_802_5_FCS:
474		case PID_RFC2684_802_5_NOFCS:
475			/*
476			 * XXX - remove the last two bytes for
477			 * PID_RFC2684_ETH_FCS?
478			 */
479			/*
480			 * Skip the padding, but not the Access
481			 * Control field.
482			 */
483			TCHECK2(*p, bridge_pad);
484			caplen -= bridge_pad;
485			length -= bridge_pad;
486			p += bridge_pad;
487
488			/*
489			 * What remains is an 802.5 Token Ring
490			 * packet.
491			 */
492			token_print(p, length, caplen);
493			return (1);
494
495		case PID_RFC2684_FDDI_FCS:
496		case PID_RFC2684_FDDI_NOFCS:
497			/*
498			 * XXX - remove the last two bytes for
499			 * PID_RFC2684_ETH_FCS?
500			 */
501			/*
502			 * Skip the padding.
503			 */
504			TCHECK2(*p, bridge_pad + 1);
505			caplen -= bridge_pad + 1;
506			length -= bridge_pad + 1;
507			p += bridge_pad + 1;
508
509			/*
510			 * What remains is an FDDI packet.
511			 */
512			fddi_print(p, length, caplen);
513			return (1);
514
515		case PID_RFC2684_BPDU:
516			stp_print(p, length);
517			return (1);
518		}
519	}
520	return (0);
521
522trunc:
523	(void)printf("[|snap]");
524	return (1);
525}
526
527
528/*
529 * Local Variables:
530 * c-style: whitesmith
531 * c-basic-offset: 8
532 * End:
533 */
534