1/*
2 * Copyright (c) 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
22/* \summary: Distance Vector Multicast Routing Protocol printer */
23
24#ifdef HAVE_CONFIG_H
25#include "config.h"
26#endif
27
28#include <netdissect-stdinc.h>
29
30#include "netdissect.h"
31#include "extract.h"
32#include "addrtoname.h"
33
34/*
35 * See: RFC 1075 and draft-ietf-idmr-dvmrp-v3
36 *
37 * DVMRP message types and flag values shamelessly stolen from
38 * mrouted/dvmrp.h.
39 */
40#define DVMRP_PROBE		1	/* for finding neighbors */
41#define DVMRP_REPORT		2	/* for reporting some or all routes */
42#define DVMRP_ASK_NEIGHBORS	3	/* sent by mapper, asking for a list */
43					/* of this router's neighbors */
44#define DVMRP_NEIGHBORS		4	/* response to such a request */
45#define DVMRP_ASK_NEIGHBORS2	5	/* as above, want new format reply */
46#define DVMRP_NEIGHBORS2	6
47#define DVMRP_PRUNE		7	/* prune message */
48#define DVMRP_GRAFT		8	/* graft message */
49#define DVMRP_GRAFT_ACK		9	/* graft acknowledgement */
50
51/*
52 * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
53 */
54#define DVMRP_NF_TUNNEL		0x01	/* neighbors reached via tunnel */
55#define DVMRP_NF_SRCRT		0x02	/* tunnel uses IP source routing */
56#define DVMRP_NF_DOWN		0x10	/* kernel state of interface */
57#define DVMRP_NF_DISABLED	0x20	/* administratively disabled */
58#define DVMRP_NF_QUERIER	0x40	/* I am the subnet's querier */
59
60static int print_probe(netdissect_options *, const u_char *, const u_char *, u_int);
61static int print_report(netdissect_options *, const u_char *, const u_char *, u_int);
62static int print_neighbors(netdissect_options *, const u_char *, const u_char *, u_int);
63static int print_neighbors2(netdissect_options *, const u_char *, const u_char *, u_int, uint8_t, uint8_t);
64static int print_prune(netdissect_options *, const u_char *);
65static int print_graft(netdissect_options *, const u_char *);
66static int print_graft_ack(netdissect_options *, const u_char *);
67
68void
69dvmrp_print(netdissect_options *ndo,
70            register const u_char *bp, register u_int len)
71{
72	register const u_char *ep;
73	register u_char type;
74	uint8_t major_version, minor_version;
75
76	ep = (const u_char *)ndo->ndo_snapend;
77	if (bp >= ep)
78		return;
79
80	ND_TCHECK(bp[1]);
81	type = bp[1];
82
83	/* Skip IGMP header */
84	bp += 8;
85	len -= 8;
86
87	switch (type) {
88
89	case DVMRP_PROBE:
90		ND_PRINT((ndo, " Probe"));
91		if (ndo->ndo_vflag) {
92			if (print_probe(ndo, bp, ep, len) < 0)
93				goto trunc;
94		}
95		break;
96
97	case DVMRP_REPORT:
98		ND_PRINT((ndo, " Report"));
99		if (ndo->ndo_vflag > 1) {
100			if (print_report(ndo, bp, ep, len) < 0)
101				goto trunc;
102		}
103		break;
104
105	case DVMRP_ASK_NEIGHBORS:
106		ND_PRINT((ndo, " Ask-neighbors(old)"));
107		break;
108
109	case DVMRP_NEIGHBORS:
110		ND_PRINT((ndo, " Neighbors(old)"));
111		if (print_neighbors(ndo, bp, ep, len) < 0)
112			goto trunc;
113		break;
114
115	case DVMRP_ASK_NEIGHBORS2:
116		ND_PRINT((ndo, " Ask-neighbors2"));
117		break;
118
119	case DVMRP_NEIGHBORS2:
120		ND_PRINT((ndo, " Neighbors2"));
121		/*
122		 * extract version from IGMP group address field
123		 */
124		bp -= 4;
125		ND_TCHECK2(bp[0], 4);
126		major_version = *(bp + 3);
127		minor_version = *(bp + 2);
128		bp += 4;
129		if (print_neighbors2(ndo, bp, ep, len, major_version,
130		    minor_version) < 0)
131			goto trunc;
132		break;
133
134	case DVMRP_PRUNE:
135		ND_PRINT((ndo, " Prune"));
136		if (print_prune(ndo, bp) < 0)
137			goto trunc;
138		break;
139
140	case DVMRP_GRAFT:
141		ND_PRINT((ndo, " Graft"));
142		if (print_graft(ndo, bp) < 0)
143			goto trunc;
144		break;
145
146	case DVMRP_GRAFT_ACK:
147		ND_PRINT((ndo, " Graft-ACK"));
148		if (print_graft_ack(ndo, bp) < 0)
149			goto trunc;
150		break;
151
152	default:
153		ND_PRINT((ndo, " [type %d]", type));
154		break;
155	}
156	return;
157
158trunc:
159	ND_PRINT((ndo, "[|dvmrp]"));
160	return;
161}
162
163static int
164print_report(netdissect_options *ndo,
165             register const u_char *bp, register const u_char *ep,
166             register u_int len)
167{
168	register uint32_t mask, origin;
169	register int metric, done;
170	register u_int i, width;
171
172	while (len > 0) {
173		if (len < 3) {
174			ND_PRINT((ndo, " [|]"));
175			return (0);
176		}
177		ND_TCHECK2(bp[0], 3);
178		mask = (uint32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
179		width = 1;
180		if (bp[0])
181			width = 2;
182		if (bp[1])
183			width = 3;
184		if (bp[2])
185			width = 4;
186
187		ND_PRINT((ndo, "\n\tMask %s", intoa(htonl(mask))));
188		bp += 3;
189		len -= 3;
190		do {
191			if (bp + width + 1 > ep) {
192				ND_PRINT((ndo, " [|]"));
193				return (0);
194			}
195			if (len < width + 1) {
196				ND_PRINT((ndo, "\n\t  [Truncated Report]"));
197				return (0);
198			}
199			origin = 0;
200			for (i = 0; i < width; ++i) {
201				ND_TCHECK(*bp);
202				origin = origin << 8 | *bp++;
203			}
204			for ( ; i < 4; ++i)
205				origin <<= 8;
206
207			ND_TCHECK(*bp);
208			metric = *bp++;
209			done = metric & 0x80;
210			metric &= 0x7f;
211			ND_PRINT((ndo, "\n\t  %s metric %d", intoa(htonl(origin)),
212				metric));
213			len -= width + 1;
214		} while (!done);
215	}
216	return (0);
217trunc:
218	return (-1);
219}
220
221static int
222print_probe(netdissect_options *ndo,
223            register const u_char *bp, register const u_char *ep,
224            register u_int len)
225{
226	register uint32_t genid;
227
228	ND_TCHECK2(bp[0], 4);
229	if ((len < 4) || ((bp + 4) > ep)) {
230		/* { (ctags) */
231		ND_PRINT((ndo, " [|}"));
232		return (0);
233	}
234	genid = EXTRACT_32BITS(bp);
235	bp += 4;
236	len -= 4;
237	ND_PRINT((ndo, ndo->ndo_vflag > 1 ? "\n\t" : " "));
238	ND_PRINT((ndo, "genid %u", genid));
239	if (ndo->ndo_vflag < 2)
240		return (0);
241
242	while ((len > 0) && (bp < ep)) {
243		ND_TCHECK2(bp[0], 4);
244		ND_PRINT((ndo, "\n\tneighbor %s", ipaddr_string(ndo, bp)));
245		bp += 4; len -= 4;
246	}
247	return (0);
248trunc:
249	return (-1);
250}
251
252static int
253print_neighbors(netdissect_options *ndo,
254                register const u_char *bp, register const u_char *ep,
255                register u_int len)
256{
257	const u_char *laddr;
258	register u_char metric;
259	register u_char thresh;
260	register int ncount;
261
262	while (len > 0 && bp < ep) {
263		ND_TCHECK2(bp[0], 7);
264		laddr = bp;
265		bp += 4;
266		metric = *bp++;
267		thresh = *bp++;
268		ncount = *bp++;
269		len -= 7;
270		while (--ncount >= 0) {
271			ND_TCHECK2(bp[0], 4);
272			ND_PRINT((ndo, " [%s ->", ipaddr_string(ndo, laddr)));
273			ND_PRINT((ndo, " %s, (%d/%d)]",
274				   ipaddr_string(ndo, bp), metric, thresh));
275			bp += 4;
276			len -= 4;
277		}
278	}
279	return (0);
280trunc:
281	return (-1);
282}
283
284static int
285print_neighbors2(netdissect_options *ndo,
286                 register const u_char *bp, register const u_char *ep,
287                 register u_int len, uint8_t major_version,
288                 uint8_t minor_version)
289{
290	const u_char *laddr;
291	register u_char metric, thresh, flags;
292	register int ncount;
293
294	ND_PRINT((ndo, " (v %d.%d):", major_version, minor_version));
295
296	while (len > 0 && bp < ep) {
297		ND_TCHECK2(bp[0], 8);
298		laddr = bp;
299		bp += 4;
300		metric = *bp++;
301		thresh = *bp++;
302		flags = *bp++;
303		ncount = *bp++;
304		len -= 8;
305		while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
306			ND_PRINT((ndo, " [%s -> ", ipaddr_string(ndo, laddr)));
307			ND_PRINT((ndo, "%s (%d/%d", ipaddr_string(ndo, bp),
308				     metric, thresh));
309			if (flags & DVMRP_NF_TUNNEL)
310				ND_PRINT((ndo, "/tunnel"));
311			if (flags & DVMRP_NF_SRCRT)
312				ND_PRINT((ndo, "/srcrt"));
313			if (flags & DVMRP_NF_QUERIER)
314				ND_PRINT((ndo, "/querier"));
315			if (flags & DVMRP_NF_DISABLED)
316				ND_PRINT((ndo, "/disabled"));
317			if (flags & DVMRP_NF_DOWN)
318				ND_PRINT((ndo, "/down"));
319			ND_PRINT((ndo, ")]"));
320			bp += 4;
321			len -= 4;
322		}
323		if (ncount != -1) {
324			ND_PRINT((ndo, " [|]"));
325			return (0);
326		}
327	}
328	return (0);
329trunc:
330	return (-1);
331}
332
333static int
334print_prune(netdissect_options *ndo,
335            register const u_char *bp)
336{
337	ND_TCHECK2(bp[0], 12);
338	ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
339	bp += 8;
340	ND_PRINT((ndo, " timer "));
341	unsigned_relts_print(ndo, EXTRACT_32BITS(bp));
342	return (0);
343trunc:
344	return (-1);
345}
346
347static int
348print_graft(netdissect_options *ndo,
349            register const u_char *bp)
350{
351	ND_TCHECK2(bp[0], 8);
352	ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
353	return (0);
354trunc:
355	return (-1);
356}
357
358static int
359print_graft_ack(netdissect_options *ndo,
360                register const u_char *bp)
361{
362	ND_TCHECK2(bp[0], 8);
363	ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
364	return (0);
365trunc:
366	return (-1);
367}
368