2 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
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
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.
21 * Code by Matt Thomas, Digital Equipment Corporation
22 * with an awful lot of hacking by Jeffrey Mogul, DECWRL
28 static const char rcsid[] =
29 "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.43 2001/10/08 21:25:22 fenner Exp $";
36 #include <sys/param.h>
39 #include <netinet/in.h>
46 #include "interface.h"
47 #include "addrtoname.h"
48 #include "extract.h" /* must come after interface.h */
51 #include "ethertype.h"
53 static struct tok cmd2str[] = {
60 { LLC_SABME, "sabme" },
66 * Returns non-zero IFF it succeeds in printing the header
69 llc_print(const u_char *p, u_int length, u_int caplen,
70 const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
78 (void)printf("[|llc]");
79 default_print((u_char *)p, caplen);
83 /* Watch out for possible alignment problems */
84 memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
86 if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
88 * This is an Ethernet_802.3 IPX frame; it has an
89 * 802.3 header (i.e., an Ethernet header where the
90 * type/length field is <= ETHERMTU, i.e. it's a length
91 * field, not a type field), but has no 802.2 header -
92 * the IPX packet starts right after the Ethernet header,
93 * with a signature of two bytes of 0xFF (which is
96 * (It might also have been an Ethernet_802.3 IPX at
97 * one time, but got bridged onto another network,
98 * such as an 802.11 network; this has appeared in at
99 * least one capture file.)
101 ipx_print(p, length);
105 if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
106 stp_print(p, length);
110 if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
111 llc.llcui == LLC_UI) {
113 * This is an Ethernet_802.2 IPX frame, with an 802.3
114 * header and an 802.2 LLC header with the source and
115 * destination SAPs being the IPX SAP.
117 * Skip DSAP, LSAP, and control field.
122 ipx_print(p, length);
126 #ifdef TCPDUMP_DO_SMB
127 if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
128 && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
130 * we don't actually have a full netbeui parser yet, but the
131 * smb parser can handle many smb-in-netbeui packets, which
132 * is very useful, so we call that
134 * We don't call it for S frames, however, just I frames
135 * (which are frames that don't have the low-order bit,
136 * LLC_S_FMT, set in the first byte of the control field)
137 * and UI frames (whose control field is just 3, LLC_U_FMT).
141 * Skip the DSAP and LSAP.
148 * OK, what type of LLC frame is this? The length
149 * of the control field depends on that - I frames
150 * have a two-byte control field, and U frames have
151 * a one-byte control field.
153 if (llc.llcu == LLC_U_FMT) {
160 * The control field in I and S frames is
163 control = EXTRACT_LE_16BITS(&llc.llcu);
168 netbeui_print(control, p, length);
172 if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
173 && llc.llcui == LLC_UI) {
174 isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst);
178 if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
179 && llc.llcui == LLC_UI) {
182 if (caplen < sizeof(llc)) {
183 (void)printf("[|llc-snap]");
184 default_print((u_char *)p, caplen);
188 (void)printf("snap %s ", protoid_string(llc.llcpi));
190 caplen -= sizeof(llc);
191 length -= sizeof(llc);
194 orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
195 et = EXTRACT_16BITS(&llc.llc_ethertype[0]);
197 case OUI_ENCAP_ETHER:
200 * This is an encapsulated Ethernet packet,
201 * or a packet bridged by some piece of
202 * Cisco hardware; the protocol ID is
203 * an Ethernet protocol type.
205 ret = ether_encap_print(et, p, length, caplen,
206 extracted_ethertype);
212 if (et == ETHERTYPE_ATALK) {
214 * No, I have no idea why Apple used one
215 * of their own OUIs, rather than
216 * 0x000000, and an Ethernet packet
217 * type, for Appletalk data packets,
218 * but used 0x000000 and an Ethernet
219 * packet type for AARP packets.
221 ret = ether_encap_print(et, p, length, caplen,
222 extracted_ethertype);
229 if (et == ETHERTYPE_CISCO_CDP) {
230 cdp_print(p, length, caplen, esrc, edst);
237 if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
238 if (eflag || esrc == NULL || edst == NULL)
239 (void)printf("%s ", llcsap_string(llc.dsap));
241 (void)printf("%s > %s %s ",
242 etheraddr_string(esrc),
243 etheraddr_string(edst),
244 llcsap_string(llc.dsap));
246 if (eflag || esrc == NULL || edst == NULL)
247 (void)printf("%s > %s ",
248 llcsap_string(llc.ssap & ~LLC_GSAP),
249 llcsap_string(llc.dsap));
251 (void)printf("%s %s > %s %s ",
252 etheraddr_string(esrc),
253 llcsap_string(llc.ssap & ~LLC_GSAP),
254 etheraddr_string(edst),
255 llcsap_string(llc.dsap));
258 if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
263 cmd = LLC_U_CMD(llc.llcu);
264 m = tok2str(cmd2str, "%02x", cmd);
265 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
266 case 0: f = 'C'; break;
267 case LLC_GSAP: f = 'R'; break;
268 case LLC_U_POLL: f = 'P'; break;
269 case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
270 default: f = '?'; break;
273 printf("%s/%c", m, f);
279 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
280 if (*p == LLC_XID_FI) {
281 printf(": %02x %02x", p[1], p[2]);
291 * The control field in I and S frames is little-endian.
293 control = EXTRACT_LE_16BITS(&llc.llcu);
294 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
295 case 0: f = 'C'; break;
296 case LLC_GSAP: f = 'R'; break;
297 case LLC_IS_POLL: f = 'P'; break;
298 case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
299 default: f = '?'; break;
302 if ((control & LLC_S_FMT) == LLC_S_FMT) {
303 static char *llc_s[] = { "rr", "rej", "rnr", "03" };
304 (void)printf("%s (r=%d,%c)",
305 llc_s[LLC_S_CMD(control)],
309 (void)printf("I (s=%d,r=%d,%c)",
318 (void)printf(" len=%d", length);
319 if (caplen > 0 && !qflag) {
320 default_print_unaligned(p, caplen);