1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996
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 * Hacked version of print-ether.c  Larry Lile <lile@stdio.com>
22 *
23 * Further tweaked to more closely resemble print-fddi.c
24 *	Guy Harris <guy@alum.mit.edu>
25 */
26
27/* \summary: Token Ring printer */
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#include <netdissect-stdinc.h>
34
35#include <string.h>
36
37#include "netdissect.h"
38#include "extract.h"
39#include "addrtoname.h"
40#include "ether.h"
41
42/*
43 * Copyright (c) 1998, Larry Lile
44 * All rights reserved.
45 *
46 * Redistribution and use in source and binary forms, with or without
47 * modification, are permitted provided that the following conditions
48 * are met:
49 * 1. Redistributions of source code must retain the above copyright
50 *    notice unmodified, this list of conditions, and the following
51 *    disclaimer.
52 * 2. Redistributions in binary form must reproduce the above copyright
53 *    notice, this list of conditions and the following disclaimer in the
54 *    documentation and/or other materials provided with the distribution.
55 *
56 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
58 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
59 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
60 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
61 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
62 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
63 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
64 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
65 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * SUCH DAMAGE.
67 *
68 */
69
70#define TOKEN_HDRLEN		14
71#define TOKEN_RING_MAC_LEN	6
72#define ROUTING_SEGMENT_MAX	16
73#define IS_SOURCE_ROUTED(trp)	((trp)->token_shost[0] & 0x80)
74#define FRAME_TYPE(trp)		(((trp)->token_fc & 0xC0) >> 6)
75#define TOKEN_FC_LLC		1
76
77#define BROADCAST(trp)		((EXTRACT_16BITS(&(trp)->token_rcf) & 0xE000) >> 13)
78#define RIF_LENGTH(trp)		((EXTRACT_16BITS(&(trp)->token_rcf) & 0x1f00) >> 8)
79#define DIRECTION(trp)		((EXTRACT_16BITS(&(trp)->token_rcf) & 0x0080) >> 7)
80#define LARGEST_FRAME(trp)	((EXTRACT_16BITS(&(trp)->token_rcf) & 0x0070) >> 4)
81#define RING_NUMBER(trp, x)	((EXTRACT_16BITS(&(trp)->token_rseg[x]) & 0xfff0) >> 4)
82#define BRIDGE_NUMBER(trp, x)	((EXTRACT_16BITS(&(trp)->token_rseg[x]) & 0x000f))
83#define SEGMENT_COUNT(trp)	((int)((RIF_LENGTH(trp) - 2) / 2))
84
85struct token_header {
86	uint8_t  token_ac;
87	uint8_t  token_fc;
88	uint8_t  token_dhost[TOKEN_RING_MAC_LEN];
89	uint8_t  token_shost[TOKEN_RING_MAC_LEN];
90	uint16_t token_rcf;
91	uint16_t token_rseg[ROUTING_SEGMENT_MAX];
92};
93
94static const char tstr[] = "[|token-ring]";
95
96/* Extract src, dst addresses */
97static inline void
98extract_token_addrs(const struct token_header *trp, char *fsrc, char *fdst)
99{
100	memcpy(fdst, (const char *)trp->token_dhost, 6);
101	memcpy(fsrc, (const char *)trp->token_shost, 6);
102}
103
104/*
105 * Print the TR MAC header
106 */
107static inline void
108token_hdr_print(netdissect_options *ndo,
109                register const struct token_header *trp, register u_int length,
110                register const u_char *fsrc, register const u_char *fdst)
111{
112	const char *srcname, *dstname;
113
114	srcname = etheraddr_string(ndo, fsrc);
115	dstname = etheraddr_string(ndo, fdst);
116
117	if (!ndo->ndo_qflag)
118		ND_PRINT((ndo, "%02x %02x ",
119		       trp->token_ac,
120		       trp->token_fc));
121	ND_PRINT((ndo, "%s > %s, length %u: ",
122	       srcname, dstname,
123	       length));
124}
125
126static const char *broadcast_indicator[] = {
127	"Non-Broadcast", "Non-Broadcast",
128	"Non-Broadcast", "Non-Broadcast",
129	"All-routes",    "All-routes",
130	"Single-route",  "Single-route"
131};
132
133static const char *direction[] = {
134	"Forward", "Backward"
135};
136
137static const char *largest_frame[] = {
138	"516",
139	"1500",
140	"2052",
141	"4472",
142	"8144",
143	"11407",
144	"17800",
145	"??"
146};
147
148u_int
149token_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen)
150{
151	const struct token_header *trp;
152	int llc_hdrlen;
153	struct ether_header ehdr;
154	struct lladdr_info src, dst;
155	u_int route_len = 0, hdr_len = TOKEN_HDRLEN;
156	int seg;
157
158	trp = (const struct token_header *)p;
159
160	if (caplen < TOKEN_HDRLEN) {
161		ND_PRINT((ndo, "%s", tstr));
162		return hdr_len;
163	}
164
165	/*
166	 * Get the TR addresses into a canonical form
167	 */
168	extract_token_addrs(trp, (char*)ESRC(&ehdr), (char*)EDST(&ehdr));
169
170	/* Adjust for source routing information in the MAC header */
171	if (IS_SOURCE_ROUTED(trp)) {
172		/* Clear source-routed bit */
173		*ESRC(&ehdr) &= 0x7f;
174
175		if (ndo->ndo_eflag)
176			token_hdr_print(ndo, trp, length, ESRC(&ehdr), EDST(&ehdr));
177
178		if (caplen < TOKEN_HDRLEN + 2) {
179			ND_PRINT((ndo, "%s", tstr));
180			return hdr_len;
181		}
182		route_len = RIF_LENGTH(trp);
183		hdr_len += route_len;
184		if (caplen < hdr_len) {
185			ND_PRINT((ndo, "%s", tstr));
186			return hdr_len;
187		}
188		if (ndo->ndo_vflag) {
189			ND_PRINT((ndo, "%s ", broadcast_indicator[BROADCAST(trp)]));
190			ND_PRINT((ndo, "%s", direction[DIRECTION(trp)]));
191
192			for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
193				ND_PRINT((ndo, " [%d:%d]", RING_NUMBER(trp, seg),
194				    BRIDGE_NUMBER(trp, seg)));
195		} else {
196			ND_PRINT((ndo, "rt = %x", EXTRACT_16BITS(&trp->token_rcf)));
197
198			for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
199				ND_PRINT((ndo, ":%x", EXTRACT_16BITS(&trp->token_rseg[seg])));
200		}
201		ND_PRINT((ndo, " (%s) ", largest_frame[LARGEST_FRAME(trp)]));
202	} else {
203		if (ndo->ndo_eflag)
204			token_hdr_print(ndo, trp, length, ESRC(&ehdr), EDST(&ehdr));
205	}
206
207	src.addr = ESRC(&ehdr);
208	src.addr_string = etheraddr_string;
209	dst.addr = EDST(&ehdr);
210	dst.addr_string = etheraddr_string;
211
212	/* Skip over token ring MAC header and routing information */
213	length -= hdr_len;
214	p += hdr_len;
215	caplen -= hdr_len;
216
217	/* Frame Control field determines interpretation of packet */
218	if (FRAME_TYPE(trp) == TOKEN_FC_LLC) {
219		/* Try to print the LLC-layer header & higher layers */
220		llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
221		if (llc_hdrlen < 0) {
222			/* packet type not known, print raw packet */
223			if (!ndo->ndo_suppress_default_print)
224				ND_DEFAULTPRINT(p, caplen);
225			llc_hdrlen = -llc_hdrlen;
226		}
227		hdr_len += llc_hdrlen;
228	} else {
229		/* Some kinds of TR packet we cannot handle intelligently */
230		/* XXX - dissect MAC packets if frame type is 0 */
231		if (!ndo->ndo_eflag)
232			token_hdr_print(ndo, trp, length + TOKEN_HDRLEN + route_len,
233			    ESRC(&ehdr), EDST(&ehdr));
234		if (!ndo->ndo_suppress_default_print)
235			ND_DEFAULTPRINT(p, caplen);
236	}
237	return (hdr_len);
238}
239
240/*
241 * This is the top level routine of the printer.  'p' points
242 * to the TR header of the packet, 'h->ts' is the timestamp,
243 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
244 * is the number of bytes actually captured.
245 */
246u_int
247token_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
248{
249	return (token_print(ndo, p, h->len, h->caplen));
250}
251