print-msdp.c revision 1.6 
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 1.6 2017/02/05 04:05:05 spz 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	ND_TCHECK2(*sp, 3);
44	/* See if we think we're at the beginning of a compound packet */
45	type = *sp;
46	len = EXTRACT_16BITS(sp + 1);
47	if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
48		goto trunc;	/* not really truncated, but still not decodable */
49	ND_PRINT((ndo, " msdp:"));
50	while (length > 0) {
51		ND_TCHECK2(*sp, 3);
52		type = *sp;
53		len = EXTRACT_16BITS(sp + 1);
54		if (len > 1400 || ndo->ndo_vflag)
55			ND_PRINT((ndo, " [len %u]", len));
56		if (len < 3)
57			goto trunc;
58		sp += 3;
59		length -= 3;
60		switch (type) {
61		case 1:	/* IPv4 Source-Active */
62		case 3: /* IPv4 Source-Active Response */
63			if (type == 1)
64				ND_PRINT((ndo, " SA"));
65			else
66				ND_PRINT((ndo, " SA-Response"));
67			ND_TCHECK(*sp);
68			ND_PRINT((ndo, " %u entries", *sp));
69			if ((u_int)((*sp * 12) + 8) < len) {
70				ND_PRINT((ndo, " [w/data]"));
71				if (ndo->ndo_vflag > 1) {
72					ND_PRINT((ndo, " "));
73					ip_print(ndo, sp + *sp * 12 + 8 - 3,
74					         len - (*sp * 12 + 8));
75				}
76			}
77			break;
78		case 2:
79			ND_PRINT((ndo, " SA-Request"));
80			ND_TCHECK2(*sp, 5);
81			ND_PRINT((ndo, " for %s", ipaddr_string(ndo, sp + 1)));
82			break;
83		case 4:
84			ND_PRINT((ndo, " Keepalive"));
85			if (len != 3)
86				ND_PRINT((ndo, "[len=%d] ", len));
87			break;
88		case 5:
89			ND_PRINT((ndo, " Notification"));
90			break;
91		default:
92			ND_PRINT((ndo, " [type=%d len=%d]", type, len));
93			break;
94		}
95		sp += (len - 3);
96		length -= (len - 3);
97	}
98	return;
99trunc:
100	ND_PRINT((ndo, " [|msdp]"));
101}
102
103/*
104 * Local Variables:
105 * c-style: whitesmith
106 * c-basic-offset: 8
107 * End:
108 */
109