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 1.32 2000/12/18 07:55:36 guy 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 */
52 static struct tok cmd2str[] = {
59 { LLC_SABME, "sabme" },
65 * Returns non-zero IFF it succeeds in printing the header
68 llc_print(const u_char *p, u_int length, u_int caplen,
69 const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
77 (void)printf("[|llc]");
78 default_print((u_char *)p, caplen);
82 /* Watch out for possible alignment problems */
83 memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
85 if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
90 /* Cisco Discovery Protocol - SNAP & ether type 0x2000 */
91 if(llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP &&
92 llc.llcui == LLC_UI &&
93 llc.ethertype[0] == 0x20 && llc.ethertype[1] == 0x00 ) {
94 cdp_print( p, length, caplen, esrc, edst);
98 if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
102 if (llc.ssap == 0xf0 && llc.dsap == 0xf0
103 && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
105 * we don't actually have a full netbeui parser yet, but the
106 * smb parser can handle many smb-in-netbeui packets, which
107 * is very useful, so we call that
109 * We don't call it for S frames, however, just I frames
110 * (which are frames that don't have the low-order bit,
111 * LLC_S_FMT, set in the first byte of the control field)
112 * and UI frames (whose control field is just 3, LLC_U_FMT).
116 * Skip the DSAP and LSAP.
123 * OK, what type of LLC frame is this? The length
124 * of the control field depends on that - I frames
125 * have a two-byte control field, and U frames have
126 * a one-byte control field.
128 if (llc.llcu == LLC_U_FMT) {
135 * The control field in I and S frames is
138 control = EXTRACT_LE_16BITS(&llc.llcu);
143 netbeui_print(control, p, p + min(caplen, length));
146 if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
147 && llc.llcui == LLC_UI) {
148 isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst);
152 if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
153 && llc.llcui == LLC_UI) {
154 if (caplen < sizeof(llc)) {
155 (void)printf("[|llc-snap]");
156 default_print((u_char *)p, caplen);
160 (void)printf("snap %s ", protoid_string(llc.llcpi));
162 caplen -= sizeof(llc);
163 length -= sizeof(llc);
166 /* This is an encapsulated Ethernet packet */
167 et = EXTRACT_16BITS(&llc.ethertype[0]);
168 ret = ether_encap_print(et, p, length, caplen,
169 extracted_ethertype);
174 if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
176 (void)printf("%s ", llcsap_string(llc.dsap));
178 (void)printf("%s > %s %s ",
179 etheraddr_string(esrc),
180 etheraddr_string(edst),
181 llcsap_string(llc.dsap));
184 (void)printf("%s > %s ",
185 llcsap_string(llc.ssap & ~LLC_GSAP),
186 llcsap_string(llc.dsap));
188 (void)printf("%s %s > %s %s ",
189 etheraddr_string(esrc),
190 llcsap_string(llc.ssap & ~LLC_GSAP),
191 etheraddr_string(edst),
192 llcsap_string(llc.dsap));
195 if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
200 cmd = LLC_U_CMD(llc.llcu);
201 m = tok2str(cmd2str, "%02x", cmd);
202 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
203 case 0: f = 'C'; break;
204 case LLC_GSAP: f = 'R'; break;
205 case LLC_U_POLL: f = 'P'; break;
206 case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
207 default: f = '?'; break;
210 printf("%s/%c", m, f);
216 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
217 if (*p == LLC_XID_FI) {
218 printf(": %02x %02x", p[1], p[2]);
225 if (cmd == LLC_UI && f == 'C') {
227 * we don't have a proper ipx decoder yet, but there
228 * is a partial one in the smb code
230 ipx_netbios_print(p,p+min(caplen,length));
236 * The control field in I and S frames is little-endian.
238 control = EXTRACT_LE_16BITS(&llc.llcu);
239 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
240 case 0: f = 'C'; break;
241 case LLC_GSAP: f = 'R'; break;
242 case LLC_IS_POLL: f = 'P'; break;
243 case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
244 default: f = '?'; break;
247 if ((control & LLC_S_FMT) == LLC_S_FMT) {
248 static char *llc_s[] = { "rr", "rej", "rnr", "03" };
249 (void)printf("%s (r=%d,%c)",
250 llc_s[LLC_S_CMD(control)],
254 (void)printf("I (s=%d,r=%d,%c)",
263 (void)printf(" len=%d", length);
264 if (caplen > 0 && !qflag) {
265 default_print_unaligned(p, caplen);