xref: /freebsd/contrib/tcpdump/print-msdp.c (revision 74bf4e164ba5851606a27d4feff27717452583e5)
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
19 static const char rcsid[] _U_ =
20     "@(#) $Header: /tcpdump/master/tcpdump/print-msdp.c,v 1.4.2.2 2003/11/16 08:51:34 guy Exp $";
21 #endif
22 
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26 
27 #include <tcpdump-stdinc.h>
28 
29 #include <stdio.h>
30 #include <stdlib.h>
31 
32 #include "interface.h"
33 #include "addrtoname.h"
34 #include "extract.h"
35 
36 #define MSDP_TYPE_MAX	7
37 
38 void
39 msdp_print(const unsigned char *sp, u_int length)
40 {
41 	unsigned int type, len;
42 
43 	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 	(void)printf(" msdp:");
50 	while (length > 0) {
51 		TCHECK2(*sp, 3);
52 		type = *sp;
53 		len = EXTRACT_16BITS(sp + 1);
54 		if (len > 1400 || vflag)
55 			printf(" [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 				(void)printf(" SA");
65 			else
66 				(void)printf(" SA-Response");
67 			TCHECK(*sp);
68 			(void)printf(" %u entries", *sp);
69 			if ((u_int)((*sp * 12) + 8) < len) {
70 				(void)printf(" [w/data]");
71 				if (vflag > 1) {
72 					(void)printf(" ");
73 					ip_print(sp + *sp * 12 + 8 - 3,
74 					         len - (*sp * 12 + 8));
75 				}
76 			}
77 			break;
78 		case 2:
79 			(void)printf(" SA-Request");
80 			TCHECK2(*sp, 5);
81 			(void)printf(" for %s", ipaddr_string(sp + 1));
82 			break;
83 		case 4:
84 			(void)printf(" Keepalive");
85 			if (len != 3)
86 				(void)printf("[len=%d] ", len);
87 			break;
88 		case 5:
89 			(void)printf(" Notification");
90 			break;
91 		default:
92 			(void)printf(" [type=%d len=%d]", type, len);
93 			break;
94 		}
95 		sp += (len - 3);
96 		length -= (len - 3);
97 	}
98 	return;
99 trunc:
100 	(void)printf(" [|msdp]");
101 }
102