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
41/*
42 * Copyright (c) 1998, Larry Lile
43 * All rights reserved.
44 *
45 * Redistribution and use in source and binary forms, with or without
46 * modification, are permitted provided that the following conditions
47 * are met:
48 * 1. Redistributions of source code must retain the above copyright
49 *    notice unmodified, this list of conditions, and the following
50 *    disclaimer.
51 * 2. Redistributions in binary form must reproduce the above copyright
52 *    notice, this list of conditions and the following disclaimer in the
53 *    documentation and/or other materials provided with the distribution.
54 *
55 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65 * SUCH DAMAGE.
66 *
67 */
68
69#define TOKEN_HDRLEN		14
70#define ROUTING_SEGMENT_MAX	16
71#define IS_SOURCE_ROUTED(trp)	((trp)->token_shost[0] & 0x80)
72#define FRAME_TYPE(trp)		((GET_U_1((trp)->token_fc) & 0xC0) >> 6)
73#define TOKEN_FC_LLC		1
74
75#define BROADCAST(trp)		((GET_BE_U_2((trp)->token_rcf) & 0xE000) >> 13)
76#define RIF_LENGTH(trp)		((GET_BE_U_2((trp)->token_rcf) & 0x1f00) >> 8)
77#define DIRECTION(trp)		((GET_BE_U_2((trp)->token_rcf) & 0x0080) >> 7)
78#define LARGEST_FRAME(trp)	((GET_BE_U_2((trp)->token_rcf) & 0x0070) >> 4)
79#define RING_NUMBER(trp, x)	((GET_BE_U_2((trp)->token_rseg[x]) & 0xfff0) >> 4)
80#define BRIDGE_NUMBER(trp, x)	(GET_BE_U_2((trp)->token_rseg[x]) & 0x000f)
81#define SEGMENT_COUNT(trp)	((int)((RIF_LENGTH(trp) - 2) / 2))
82
83struct token_header {
84	nd_uint8_t   token_ac;
85	nd_uint8_t   token_fc;
86	nd_mac_addr  token_dhost;
87	nd_mac_addr  token_shost;
88	nd_uint16_t  token_rcf;
89	nd_uint16_t  token_rseg[ROUTING_SEGMENT_MAX];
90};
91
92
93/* Extract src, dst addresses */
94static void
95extract_token_addrs(const struct token_header *trp, char *fsrc, char *fdst)
96{
97	memcpy(fdst, (const char *)trp->token_dhost, 6);
98	memcpy(fsrc, (const char *)trp->token_shost, 6);
99}
100
101/*
102 * Print the TR MAC header
103 */
104static void
105token_hdr_print(netdissect_options *ndo,
106                const struct token_header *trp, u_int length,
107                const u_char *fsrc, const u_char *fdst)
108{
109	const char *srcname, *dstname;
110
111	srcname = etheraddr_string(ndo, fsrc);
112	dstname = etheraddr_string(ndo, fdst);
113
114	if (!ndo->ndo_qflag)
115		ND_PRINT("%02x %02x ",
116		       GET_U_1(trp->token_ac),
117		       GET_U_1(trp->token_fc));
118	ND_PRINT("%s > %s, length %u: ",
119	       srcname, dstname,
120	       length);
121}
122
123static const char *broadcast_indicator[] = {
124	"Non-Broadcast", "Non-Broadcast",
125	"Non-Broadcast", "Non-Broadcast",
126	"All-routes",    "All-routes",
127	"Single-route",  "Single-route"
128};
129
130static const char *direction[] = {
131	"Forward", "Backward"
132};
133
134static const char *largest_frame[] = {
135	"516",
136	"1500",
137	"2052",
138	"4472",
139	"8144",
140	"11407",
141	"17800",
142	"??"
143};
144
145u_int
146token_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen)
147{
148	const struct token_header *trp;
149	int llc_hdrlen;
150	nd_mac_addr srcmac, dstmac;
151	struct lladdr_info src, dst;
152	u_int route_len = 0, hdr_len = TOKEN_HDRLEN;
153	int seg;
154
155	ndo->ndo_protocol = "token-ring";
156	trp = (const struct token_header *)p;
157
158	if (caplen < TOKEN_HDRLEN) {
159		nd_print_trunc(ndo);
160		return hdr_len;
161	}
162
163	/*
164	 * Get the TR addresses into a canonical form
165	 */
166	extract_token_addrs(trp, (char*)srcmac, (char*)dstmac);
167
168	/* Adjust for source routing information in the MAC header */
169	if (IS_SOURCE_ROUTED(trp)) {
170		/* Clear source-routed bit */
171		srcmac[0] &= 0x7f;
172
173		if (ndo->ndo_eflag)
174			token_hdr_print(ndo, trp, length, srcmac, dstmac);
175
176		if (caplen < TOKEN_HDRLEN + 2) {
177			nd_print_trunc(ndo);
178			return hdr_len;
179		}
180		route_len = RIF_LENGTH(trp);
181		hdr_len += route_len;
182		if (caplen < hdr_len) {
183			nd_print_trunc(ndo);
184			return hdr_len;
185		}
186		if (ndo->ndo_vflag) {
187			ND_PRINT("%s ", broadcast_indicator[BROADCAST(trp)]);
188			ND_PRINT("%s", direction[DIRECTION(trp)]);
189
190			for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
191				ND_PRINT(" [%u:%u]", RING_NUMBER(trp, seg),
192				    BRIDGE_NUMBER(trp, seg));
193		} else {
194			ND_PRINT("rt = %x", GET_BE_U_2(trp->token_rcf));
195
196			for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
197				ND_PRINT(":%x",
198					 GET_BE_U_2(trp->token_rseg[seg]));
199		}
200		ND_PRINT(" (%s) ", largest_frame[LARGEST_FRAME(trp)]);
201	} else {
202		if (ndo->ndo_eflag)
203			token_hdr_print(ndo, trp, length, srcmac, dstmac);
204	}
205
206	src.addr = srcmac;
207	src.addr_string = etheraddr_string;
208	dst.addr = dstmac;
209	dst.addr_string = etheraddr_string;
210
211	/* Skip over token ring MAC header and routing information */
212	length -= hdr_len;
213	p += hdr_len;
214	caplen -= hdr_len;
215
216	/* Frame Control field determines interpretation of packet */
217	if (FRAME_TYPE(trp) == TOKEN_FC_LLC) {
218		/* Try to print the LLC-layer header & higher layers */
219		llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
220		if (llc_hdrlen < 0) {
221			/* packet type not known, print raw packet */
222			if (!ndo->ndo_suppress_default_print)
223				ND_DEFAULTPRINT(p, caplen);
224			llc_hdrlen = -llc_hdrlen;
225		}
226		hdr_len += llc_hdrlen;
227	} else {
228		/* Some kinds of TR packet we cannot handle intelligently */
229		/* XXX - dissect MAC packets if frame type is 0 */
230		if (!ndo->ndo_eflag)
231			token_hdr_print(ndo, trp, length + TOKEN_HDRLEN + route_len,
232			    srcmac, dstmac);
233		if (!ndo->ndo_suppress_default_print)
234			ND_DEFAULTPRINT(p, caplen);
235	}
236	return (hdr_len);
237}
238
239/*
240 * This is the top level routine of the printer.  'p' points
241 * to the TR header of the packet, 'h->ts' is the timestamp,
242 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
243 * is the number of bytes actually captured.
244 */
245void
246token_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
247{
248	ndo->ndo_protocol = "token-ring";
249	ndo->ndo_ll_hdr_len += token_print(ndo, p, h->len, h->caplen);
250}
251