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: releng/11.0/contrib/tcpdump/print-llc.c 277982 2015-01-31 16:34:39Z pfg $
25 */
26
27#define NETDISSECT_REWORKED
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include <tcpdump-stdinc.h>
33
34#include "interface.h"
35#include "addrtoname.h"
36#include "extract.h"			/* must come after interface.h */
37
38#include "llc.h"
39#include "ethertype.h"
40#include "oui.h"
41
42static const struct tok llc_values[] = {
43        { LLCSAP_NULL,     "Null" },
44        { LLCSAP_GLOBAL,   "Global" },
45        { LLCSAP_8021B_I,  "802.1B I" },
46        { LLCSAP_8021B_G,  "802.1B G" },
47        { LLCSAP_IP,       "IP" },
48        { LLCSAP_SNA,      "SNA" },
49        { LLCSAP_PROWAYNM, "ProWay NM" },
50        { LLCSAP_8021D,    "STP" },
51        { LLCSAP_RS511,    "RS511" },
52        { LLCSAP_ISO8208,  "ISO8208" },
53        { LLCSAP_PROWAY,   "ProWay" },
54        { LLCSAP_SNAP,     "SNAP" },
55        { LLCSAP_IPX,      "IPX" },
56        { LLCSAP_NETBEUI,  "NetBeui" },
57        { LLCSAP_ISONS,    "OSI" },
58        { 0,               NULL },
59};
60
61static const struct tok llc_cmd_values[] = {
62	{ LLC_UI,	"ui" },
63	{ LLC_TEST,	"test" },
64	{ LLC_XID,	"xid" },
65	{ LLC_UA,	"ua" },
66	{ LLC_DISC,	"disc" },
67	{ LLC_DM,	"dm" },
68	{ LLC_SABME,	"sabme" },
69	{ LLC_FRMR,	"frmr" },
70	{ 0,		NULL }
71};
72
73static const struct tok llc_flag_values[] = {
74        { 0, "Command" },
75        { LLC_GSAP, "Response" },
76        { LLC_U_POLL, "Poll" },
77        { LLC_GSAP|LLC_U_POLL, "Final" },
78        { LLC_IS_POLL, "Poll" },
79        { LLC_GSAP|LLC_IS_POLL, "Final" },
80	{ 0, NULL }
81};
82
83
84static const struct tok llc_ig_flag_values[] = {
85        { 0, "Individual" },
86        { LLC_IG, "Group" },
87	{ 0, NULL }
88};
89
90
91static const struct tok llc_supervisory_values[] = {
92        { 0, "Receiver Ready" },
93        { 1, "Receiver not Ready" },
94        { 2, "Reject" },
95	{ 0,             NULL }
96};
97
98
99static const struct tok cisco_values[] = {
100	{ PID_CISCO_CDP, "CDP" },
101	{ PID_CISCO_VTP, "VTP" },
102	{ PID_CISCO_DTP, "DTP" },
103	{ PID_CISCO_UDLD, "UDLD" },
104	{ PID_CISCO_PVST, "PVST" },
105	{ PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
106	{ 0,             NULL }
107};
108
109static const struct tok bridged_values[] = {
110	{ PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
111	{ PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
112	{ PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
113	{ PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
114	{ PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
115	{ PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
116	{ PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
117	{ PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
118	{ PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
119	{ PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
120	{ PID_RFC2684_BPDU,        "BPDU" },
121	{ 0,                       NULL },
122};
123
124static const struct tok null_values[] = {
125	{ 0,             NULL }
126};
127
128struct oui_tok {
129	uint32_t	oui;
130	const struct tok *tok;
131};
132
133static const struct oui_tok oui_to_tok[] = {
134	{ OUI_ENCAP_ETHER, ethertype_values },
135	{ OUI_CISCO_90, ethertype_values },	/* uses some Ethertype values */
136	{ OUI_APPLETALK, ethertype_values },	/* uses some Ethertype values */
137	{ OUI_CISCO, cisco_values },
138	{ OUI_RFC2684, bridged_values },	/* bridged, RFC 2427 FR or RFC 2864 ATM */
139	{ 0, NULL }
140};
141
142/*
143 * Returns non-zero IFF it succeeds in printing the header
144 */
145int
146llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
147	  const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
148{
149	uint8_t dsap_field, dsap, ssap_field, ssap;
150	uint16_t control;
151	int is_u;
152	register int ret;
153
154	*extracted_ethertype = 0;
155
156	if (caplen < 3 || length < 3) {
157		ND_PRINT((ndo, "[|llc]"));
158		ND_DEFAULTPRINT((u_char *)p, caplen);
159		return (1);
160	}
161
162	dsap_field = *p;
163	ssap_field = *(p + 1);
164
165	/*
166	 * OK, what type of LLC frame is this?  The length
167	 * of the control field depends on that - I frames
168	 * have a two-byte control field, and U frames have
169	 * a one-byte control field.
170	 */
171	control = *(p + 2);
172	if ((control & LLC_U_FMT) == LLC_U_FMT) {
173		/*
174		 * U frame.
175		 */
176		is_u = 1;
177	} else {
178		/*
179		 * The control field in I and S frames is
180		 * 2 bytes...
181		 */
182		if (caplen < 4 || length < 4) {
183			ND_PRINT((ndo, "[|llc]"));
184			ND_DEFAULTPRINT((u_char *)p, caplen);
185			return (1);
186		}
187
188		/*
189		 * ...and is little-endian.
190		 */
191		control = EXTRACT_LE_16BITS(p + 2);
192		is_u = 0;
193	}
194
195	if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
196		/*
197		 * This is an Ethernet_802.3 IPX frame; it has an
198		 * 802.3 header (i.e., an Ethernet header where the
199		 * type/length field is <= ETHERMTU, i.e. it's a length
200		 * field, not a type field), but has no 802.2 header -
201		 * the IPX packet starts right after the Ethernet header,
202		 * with a signature of two bytes of 0xFF (which is
203		 * LLCSAP_GLOBAL).
204		 *
205		 * (It might also have been an Ethernet_802.3 IPX at
206		 * one time, but got bridged onto another network,
207		 * such as an 802.11 network; this has appeared in at
208		 * least one capture file.)
209		 */
210
211            if (ndo->ndo_eflag)
212		ND_PRINT((ndo, "IPX 802.3: "));
213
214            ipx_print(ndo, p, length);
215            return (1);
216	}
217
218	dsap = dsap_field & ~LLC_IG;
219	ssap = ssap_field & ~LLC_GSAP;
220
221	if (ndo->ndo_eflag) {
222                ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
223                       tok2str(llc_values, "Unknown", dsap),
224                       dsap,
225                       tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
226                       tok2str(llc_values, "Unknown", ssap),
227                       ssap,
228                       tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)));
229
230		if (is_u) {
231			ND_PRINT((ndo, ", ctrl 0x%02x: ", control));
232		} else {
233			ND_PRINT((ndo, ", ctrl 0x%04x: ", control));
234		}
235	}
236
237	if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
238	    control == LLC_UI) {
239		stp_print(ndo, p+3, length-3);
240		return (1);
241	}
242
243	if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
244	    control == LLC_UI) {
245		if (caplen < 4 || length < 4) {
246			ND_PRINT((ndo, "[|llc]"));
247			ND_DEFAULTPRINT((u_char *)p, caplen);
248			return (1);
249		}
250		ip_print(ndo, 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 (ndo->ndo_eflag)
264                        ND_PRINT((ndo, "IPX 802.2: "));
265
266		ipx_print(ndo, 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		} else {
291			p += 4;
292			length -= 4;
293		}
294		netbeui_print(ndo, control, p, length);
295		return (1);
296	}
297#endif
298	if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
299	    && control == LLC_UI) {
300		isoclns_print(ndo, p + 3, length - 3, caplen - 3);
301		return (1);
302	}
303
304	if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
305	    && control == LLC_UI) {
306		/*
307		 * XXX - what *is* the right bridge pad value here?
308		 * Does anybody ever bridge one form of LAN traffic
309		 * over a networking type that uses 802.2 LLC?
310		 */
311		ret = snap_print(ndo, p+3, length-3, caplen-3, 2);
312		if (ret)
313			return (ret);
314	}
315
316	if (!ndo->ndo_eflag) {
317		if (ssap == dsap) {
318			if (esrc == NULL || edst == NULL)
319				ND_PRINT((ndo, "%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
320			else
321				ND_PRINT((ndo, "%s > %s %s ",
322						etheraddr_string(ndo, esrc),
323						etheraddr_string(ndo, edst),
324						tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
325		} else {
326			if (esrc == NULL || edst == NULL)
327				ND_PRINT((ndo, "%s > %s ",
328                                        tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
329					tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
330			else
331				ND_PRINT((ndo, "%s %s > %s %s ",
332					etheraddr_string(ndo, esrc),
333                                        tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
334					etheraddr_string(ndo, edst),
335					tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
336		}
337	}
338
339	if (is_u) {
340		ND_PRINT((ndo, "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
347		if ((control & ~LLC_U_POLL) == LLC_XID) {
348			if (*p == LLC_XID_FI) {
349				ND_PRINT((ndo, ": %02x %02x", p[1], p[2]));
350			}
351		}
352	} else {
353		if ((control & LLC_S_FMT) == LLC_S_FMT) {
354			ND_PRINT((ndo, "Supervisory, %s, rcv seq %u, Flags [%s], length %u",
355				tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
356				LLC_IS_NR(control),
357				tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
358                                length));
359		} else {
360			ND_PRINT((ndo, "Information, send seq %u, rcv seq %u, Flags [%s], length %u",
361				LLC_I_NS(control),
362				LLC_IS_NR(control),
363				tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
364                                length));
365		}
366	}
367	return(1);
368}
369
370int
371snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
372{
373	uint32_t orgcode;
374	register u_short et;
375	register int ret;
376
377	ND_TCHECK2(*p, 5);
378	if (caplen < 5 || length < 5)
379		goto trunc;
380	orgcode = EXTRACT_24BITS(p);
381	et = EXTRACT_16BITS(p + 3);
382
383	if (ndo->ndo_eflag) {
384		const struct tok *tok = null_values;
385		const struct oui_tok *otp;
386
387		for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
388			if (otp->oui == orgcode) {
389				tok = otp->tok;
390				break;
391			}
392		}
393		ND_PRINT((ndo, "oui %s (0x%06x), %s %s (0x%04x): ",
394		     tok2str(oui_values, "Unknown", orgcode),
395		     orgcode,
396		     (orgcode == 0x000000 ? "ethertype" : "pid"),
397		     tok2str(tok, "Unknown", et),
398		     et));
399	}
400	p += 5;
401	length -= 5;
402	caplen -= 5;
403
404	switch (orgcode) {
405	case OUI_ENCAP_ETHER:
406	case OUI_CISCO_90:
407		/*
408		 * This is an encapsulated Ethernet packet,
409		 * or a packet bridged by some piece of
410		 * Cisco hardware; the protocol ID is
411		 * an Ethernet protocol type.
412		 */
413		ret = ethertype_print(ndo, et, p, length, caplen);
414		if (ret)
415			return (ret);
416		break;
417
418	case OUI_APPLETALK:
419		if (et == ETHERTYPE_ATALK) {
420			/*
421			 * No, I have no idea why Apple used one
422			 * of their own OUIs, rather than
423			 * 0x000000, and an Ethernet packet
424			 * type, for Appletalk data packets,
425			 * but used 0x000000 and an Ethernet
426			 * packet type for AARP packets.
427			 */
428			ret = ethertype_print(ndo, et, p, length, caplen);
429			if (ret)
430				return (ret);
431		}
432		break;
433
434	case OUI_CISCO:
435                switch (et) {
436                case PID_CISCO_CDP:
437                        cdp_print(ndo, p, length, caplen);
438                        return (1);
439                case PID_CISCO_DTP:
440                        dtp_print(ndo, p, length);
441                        return (1);
442                case PID_CISCO_UDLD:
443                        udld_print(ndo, p, length);
444                        return (1);
445                case PID_CISCO_VTP:
446                        vtp_print(ndo, p, length);
447                        return (1);
448                case PID_CISCO_PVST:
449                case PID_CISCO_VLANBRIDGE:
450                        stp_print(ndo, p, length);
451                        return (1);
452                default:
453                        break;
454                }
455		break;
456
457	case OUI_RFC2684:
458		switch (et) {
459
460		case PID_RFC2684_ETH_FCS:
461		case PID_RFC2684_ETH_NOFCS:
462			/*
463			 * XXX - remove the last two bytes for
464			 * PID_RFC2684_ETH_FCS?
465			 */
466			/*
467			 * Skip the padding.
468			 */
469			ND_TCHECK2(*p, bridge_pad);
470			caplen -= bridge_pad;
471			length -= bridge_pad;
472			p += bridge_pad;
473
474			/*
475			 * What remains is an Ethernet packet.
476			 */
477			ether_print(ndo, p, length, caplen, NULL, NULL);
478			return (1);
479
480		case PID_RFC2684_802_5_FCS:
481		case PID_RFC2684_802_5_NOFCS:
482			/*
483			 * XXX - remove the last two bytes for
484			 * PID_RFC2684_ETH_FCS?
485			 */
486			/*
487			 * Skip the padding, but not the Access
488			 * Control field.
489			 */
490			ND_TCHECK2(*p, bridge_pad);
491			caplen -= bridge_pad;
492			length -= bridge_pad;
493			p += bridge_pad;
494
495			/*
496			 * What remains is an 802.5 Token Ring
497			 * packet.
498			 */
499			token_print(ndo, p, length, caplen);
500			return (1);
501
502		case PID_RFC2684_FDDI_FCS:
503		case PID_RFC2684_FDDI_NOFCS:
504			/*
505			 * XXX - remove the last two bytes for
506			 * PID_RFC2684_ETH_FCS?
507			 */
508			/*
509			 * Skip the padding.
510			 */
511			ND_TCHECK2(*p, bridge_pad + 1);
512			caplen -= bridge_pad + 1;
513			length -= bridge_pad + 1;
514			p += bridge_pad + 1;
515
516			/*
517			 * What remains is an FDDI packet.
518			 */
519			fddi_print(ndo, p, length, caplen);
520			return (1);
521
522		case PID_RFC2684_BPDU:
523			stp_print(ndo, p, length);
524			return (1);
525		}
526	}
527	return (0);
528
529trunc:
530	ND_PRINT((ndo, "[|snap]"));
531	return (1);
532}
533
534
535/*
536 * Local Variables:
537 * c-style: whitesmith
538 * c-basic-offset: 8
539 * End:
540 */
541