print-msdp.c revision 98524 
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#ifndef lint
19static const char rcsid[] =
20    "@(#) $Header: /tcpdump/master/tcpdump/print-msdp.c,v 1.2 2001/12/10 08:06:40 guy Exp $";
21#endif
22
23#ifdef HAVE_CONFIG_H
24#include "config.h"
25#endif
26
27#include <stdio.h>
28#include <stdlib.h>
29#include <unistd.h>
30
31#include <netinet/in.h>
32
33#include "interface.h"
34#include "addrtoname.h"
35#include "extract.h"
36
37#define MSDP_TYPE_MAX	7
38
39void
40msdp_print(const unsigned char *sp, u_int length)
41{
42	unsigned int type, len;
43
44	TCHECK2(*sp, 3);
45	/* See if we think we're at the beginning of a compound packet */
46	type = *sp;
47	len = EXTRACT_16BITS(sp + 1);
48	if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
49		goto trunc;	/* not really truncated, but still not decodable */
50	(void)printf(" msdp:");
51	while (length > 0) {
52		TCHECK2(*sp, 3);
53		type = *sp;
54		len = EXTRACT_16BITS(sp + 1);
55		if (len > 1400 || vflag)
56			printf(" [len %d]", len);
57		if (len < 3)
58			goto trunc;
59		sp += 3;
60		length -= 3;
61		switch (type) {
62		case 1:	/* IPv4 Source-Active */
63		case 3: /* IPv4 Source-Active Response */
64			if (type == 1)
65				(void)printf(" SA");
66			else
67				(void)printf(" SA-Response");
68			TCHECK(*sp);
69			(void)printf(" %d entries", *sp);
70			if (*sp * 12 + 8 < len) {
71				(void)printf(" [w/data]");
72				if (vflag > 1) {
73					(void)printf(" ");
74					ip_print(sp + *sp * 12 + 8 - 3,
75					         len - (*sp * 12 + 8));
76				}
77			}
78			break;
79		case 2:
80			(void)printf(" SA-Request");
81			TCHECK2(*sp, 5);
82			(void)printf(" for %s", ipaddr_string(sp + 1));
83			break;
84		case 4:
85			(void)printf(" Keepalive");
86			if (len != 3)
87				(void)printf("[len=%d] ", len);
88			break;
89		case 5:
90			(void)printf(" Notification");
91			break;
92		default:
93			(void)printf(" [type=%d len=%d]", type, len);
94			break;
95		}
96		sp += (len - 3);
97		length -= (len - 3);
98	}
99	return;
100trunc:
101	(void)printf(" [|msdp]");
102}
103