1/*
2 * Copyright (c) 2001 William C. Fenner.
3 *                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
7 * distributions retain the above copyright notice and this paragraph
8 * in its entirety, and (2) distributions including binary code include
9 * the above copyright notice and this paragraph in its entirety in
10 * the documentation or other materials provided with the distribution.
11 * The name of William C. Fenner may not be used to endorse or
12 * promote products derived from this software without specific prior
13 * written permission.  THIS SOFTWARE IS PROVIDED ``AS IS'' AND
14 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
15 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
16 * FOR A PARTICULAR PURPOSE.
17 */
18
19#include <sys/cdefs.h>
20#ifndef lint
21__RCSID("$NetBSD: print-msdp.c,v 1.7 2023/08/17 20:19:40 christos Exp $");
22#endif
23
24/* \summary: Multicast Source Discovery Protocol (MSDP) printer */
25
26#ifdef HAVE_CONFIG_H
27#include <config.h>
28#endif
29
30#include "netdissect-stdinc.h"
31
32#include "netdissect.h"
33#include "addrtoname.h"
34#include "extract.h"
35
36#define MSDP_TYPE_MAX	7
37
38void
39msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
40{
41	unsigned int type, len;
42
43	ndo->ndo_protocol = "msdp";
44	ND_PRINT(": ");
45	nd_print_protocol(ndo);
46	/* See if we think we're at the beginning of a compound packet */
47	type = GET_U_1(sp);
48	len = GET_BE_U_2(sp + 1);
49	if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
50		goto trunc;	/* not really truncated, but still not decodable */
51	while (length != 0) {
52		type = GET_U_1(sp);
53		len = GET_BE_U_2(sp + 1);
54		if (len > 1400 || ndo->ndo_vflag)
55			ND_PRINT(" [len %u]", len);
56		if (len < 3)
57			goto trunc;
58		if (length < len)
59			goto trunc;
60		sp += 3;
61		length -= 3;
62		switch (type) {
63		case 1:	/* IPv4 Source-Active */
64		case 3: /* IPv4 Source-Active Response */
65			if (type == 1)
66				ND_PRINT(" SA");
67			else
68				ND_PRINT(" SA-Response");
69			ND_PRINT(" %u entries", GET_U_1(sp));
70			if ((u_int)((GET_U_1(sp) * 12) + 8) < len) {
71				ND_PRINT(" [w/data]");
72				if (ndo->ndo_vflag > 1) {
73					ND_PRINT(" ");
74					ip_print(ndo, sp +
75						 GET_U_1(sp) * 12 + 8 - 3,
76						 len - (GET_U_1(sp) * 12 + 8));
77				}
78			}
79			break;
80		case 2:
81			ND_PRINT(" SA-Request");
82			ND_PRINT(" for %s", GET_IPADDR_STRING(sp + 1));
83			break;
84		case 4:
85			ND_PRINT(" Keepalive");
86			if (len != 3)
87				ND_PRINT("[len=%u] ", len);
88			break;
89		case 5:
90			ND_PRINT(" Notification");
91			break;
92		default:
93			ND_PRINT(" [type=%u len=%u]", type, len);
94			break;
95		}
96		sp += (len - 3);
97		length -= (len - 3);
98	}
99	return;
100trunc:
101	nd_print_trunc(ndo);
102}
103