summaryrefslogtreecommitdiff
path: root/usr.sbin/tcpdump/print-llc.c
blob: 2f78c6809dbd41ad4c5e33ac8851e24ecfafd8e7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
/*	$OpenBSD: print-llc.c,v 1.18 2009/10/27 23:59:55 deraadt Exp $	*/

/*
 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Code by Matt Thomas, Digital Equipment Corporation
 *	with an awful lot of hacking by Jeffrey Mogul, DECWRL
 */

#include <sys/param.h>
#include <sys/time.h>

#include <netinet/in.h>

#include <ctype.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

#include "interface.h"
#include "addrtoname.h"
#include "extract.h"			/* must come after interface.h */
#include "ethertype.h"

#include "llc.h"

static struct tok cmd2str[] = {
	{ LLC_UI,	"ui" },
	{ LLC_TEST,	"test" },
	{ LLC_XID,	"xid" },
	{ LLC_UA,	"ua" },
	{ LLC_DISC,	"disc" },
	{ LLC_DM,	"dm" },
	{ LLC_SABME,	"sabme" },
	{ LLC_FRMR,	"frmr" },
	{ 0,		NULL }
};

/*
 * Returns non-zero IFF it succeeds in printing the header
 */
int
llc_print(const u_char *p, u_int length, u_int caplen,
	  const u_char *esrc, const u_char *edst)
{
	struct llc llc;
	register u_short et;
#if 0
	u_short control;
#endif
	register int ret;

	if (caplen < 3) {
		(void)printf("[|llc]");
		default_print((u_char *)p, caplen);
		return(0);
	}

	/* Watch out for possible alignment problems */
	memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));

	if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
		ipx_print(p, length);
		return (1);
	}
#ifdef notyet
	else if (p[0] == 0xf0 && p[1] == 0xf0)
		netbios_print(p, length);
#endif
	if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
	    && llc.llcui == LLC_UI) {
		isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst);
		return (1);
	}

	if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
	    && llc.llcui == LLC_UI) {
		if (caplen < sizeof(llc)) {
		    (void)printf("[|llc-snap]");
		    default_print((u_char *)p, caplen);
		    return (0);
		}

		/* Cisco Discovery Protocol  - SNAP & ether type 0x2000 */
		if (llc.ethertype[0] == 0x20 && llc.ethertype[1] == 0x00) {
			cdp_print(p, length, caplen, esrc, edst);
			return (1);
		}
		/* Shared Spanning Tree Protocol - SNAP & ether type 0x010b */
		if (llc.ethertype[0] == 0x01 && llc.ethertype[1] == 0x0b) {
			stp_print(p, length);
			return (1);
		}

		if (vflag)
			(void)printf("snap %s ", protoid_string(llc.llcpi));

		caplen -= sizeof(llc);
		length -= sizeof(llc);
		p += sizeof(llc);

		/* This is an encapsulated Ethernet packet */
		et = EXTRACT_16BITS(&llc.ethertype[0]);

		/*
		 * Some protocols have special handling if they are 802.3
		 * SNAP encapsulated vs vers II encapsulated. Handle
		 * those special protocols here, and hand the rest to
		 * print-ether.c so we don't have to duplicate
		 * all that code here.
		 */
		switch (et) {
		case ETHERTYPE_ATALK:
			atalk_print(p, length);
			ret = 1;
			break;
		default:
			ret = ether_encap_print(et, p, length, caplen);
			break;
		}

		if (ret)
			return (ret);
	}

	if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
		stp_print(p, length);
		return (1);
	}

#if 0
	if (llc.ssap == 0xf0 && llc.dsap == 0xf0) {
		/*
		 * we don't actually have a full netbeui parser yet, but the
		 * smb parser can handle many smb-in-netbeui packets, which
		 * is very useful, so we call that
		 */

		/*
		 * Skip the DSAP and LSAP.
		 */
		p += 2;
		length -= 2;
		caplen -= 2;

		/*
		 * OK, what type of LLC frame is this?  The length
		 * of the control field depends on that - S or I
		 * frames have a two-byte control field, and U frames
		 * have a one-byte control field.
		 */
		if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
			control = llc.llcu;
			p += 1;
			length -= 1;
			caplen -= 1;
		} else {
			control = llc.llcis;
			p += 2;
			length -= 2;
			caplen -= 2;
		}

		netbeui_print(control, p, p + min(caplen, length));
		return (1);
	}
#endif

	if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
		if (eflag)
			(void)printf("%s ", llcsap_string(llc.dsap));
		else
			(void)printf("%s > %s %s ",
					etheraddr_string(esrc),
					etheraddr_string(edst),
					llcsap_string(llc.dsap));
	} else {
		if (eflag)
			(void)printf("%s > %s ",
				llcsap_string(llc.ssap & ~LLC_GSAP),
				llcsap_string(llc.dsap));
		else
			(void)printf("%s %s > %s %s ",
				etheraddr_string(esrc),
				llcsap_string(llc.ssap & ~LLC_GSAP),
				etheraddr_string(edst),
				llcsap_string(llc.dsap));
	}

	if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
		const char *m;
		char f;
		m = tok2str(cmd2str, "%02x", LLC_U_CMD(llc.llcu));
		switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
		    case 0:			f = 'C'; break;
		    case LLC_GSAP:		f = 'R'; break;
		    case LLC_U_POLL:		f = 'P'; break;
		    case LLC_GSAP|LLC_U_POLL:	f = 'F'; break;
		    default:			f = '?'; break;
		}

		printf("%s/%c", m, f);

		if (caplen < 6) {
			default_print_unaligned(p, caplen);
			return (0);
		}
		p += 3;
		length -= 3;
		caplen -= 3;

		if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
		    if (*p == LLC_XID_FI) {
			printf(": %02x %02x", p[1], p[2]);
			p += 3;
			length -= 3;
			caplen -= 3;
		    }
		}

#if 0
		if (!strcmp(m,"ui") && f=='C') {
			/*
			 * we don't have a proper ipx decoder yet, but there
			 * is a partial one in the smb code
			 */
			ipx_netbios_print(p,p+min(caplen,length));
		}
#endif

	} else {
		char f;
		if (caplen < 4) {
			default_print_unaligned(p, caplen);
			return (0);
		}
		llc.llcis = ntohs(llc.llcis);
		switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
		    case 0:			f = 'C'; break;
		    case LLC_GSAP:		f = 'R'; break;
		    case LLC_U_POLL:		f = 'P'; break;
		    case LLC_GSAP|LLC_U_POLL:	f = 'F'; break;
		    default:			f = '?'; break;
		}

		if ((llc.llcu & LLC_S_FMT) == LLC_S_FMT) {
			static char *llc_s[] = { "rr", "rej", "rnr", "03" };
			(void)printf("%s (r=%d,%c)",
				llc_s[LLC_S_CMD(llc.llcis)],
				LLC_IS_NR(llc.llcis),
				f);
		} else {
			(void)printf("I (s=%d,r=%d,%c)",
				LLC_I_NS(llc.llcis),
				LLC_IS_NR(llc.llcis),
				f);
		}
		p += 4;
		length -= 4;
		caplen -= 4;
	}
	(void)printf(" len=%d", length);
	return(1);
}