xref: /freebsd/contrib/tcpdump/print-msdp.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
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 #define NETDISSECT_REWORKED
20 #ifdef HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23 
24 #include <tcpdump-stdinc.h>
25 
26 #include "interface.h"
27 #include "addrtoname.h"
28 #include "extract.h"
29 
30 #define MSDP_TYPE_MAX	7
31 
32 void
33 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
34 {
35 	unsigned int type, len;
36 
37 	ND_TCHECK2(*sp, 3);
38 	/* See if we think we're at the beginning of a compound packet */
39 	type = *sp;
40 	len = EXTRACT_16BITS(sp + 1);
41 	if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
42 		goto trunc;	/* not really truncated, but still not decodable */
43 	ND_PRINT((ndo, " msdp:"));
44 	while (length > 0) {
45 		ND_TCHECK2(*sp, 3);
46 		type = *sp;
47 		len = EXTRACT_16BITS(sp + 1);
48 		if (len > 1400 || ndo->ndo_vflag)
49 			ND_PRINT((ndo, " [len %u]", len));
50 		if (len < 3)
51 			goto trunc;
52 		sp += 3;
53 		length -= 3;
54 		switch (type) {
55 		case 1:	/* IPv4 Source-Active */
56 		case 3: /* IPv4 Source-Active Response */
57 			if (type == 1)
58 				ND_PRINT((ndo, " SA"));
59 			else
60 				ND_PRINT((ndo, " SA-Response"));
61 			ND_TCHECK(*sp);
62 			ND_PRINT((ndo, " %u entries", *sp));
63 			if ((u_int)((*sp * 12) + 8) < len) {
64 				ND_PRINT((ndo, " [w/data]"));
65 				if (ndo->ndo_vflag > 1) {
66 					ND_PRINT((ndo, " "));
67 					ip_print(ndo, sp + *sp * 12 + 8 - 3,
68 					         len - (*sp * 12 + 8));
69 				}
70 			}
71 			break;
72 		case 2:
73 			ND_PRINT((ndo, " SA-Request"));
74 			ND_TCHECK2(*sp, 5);
75 			ND_PRINT((ndo, " for %s", ipaddr_string(ndo, sp + 1)));
76 			break;
77 		case 4:
78 			ND_PRINT((ndo, " Keepalive"));
79 			if (len != 3)
80 				ND_PRINT((ndo, "[len=%d] ", len));
81 			break;
82 		case 5:
83 			ND_PRINT((ndo, " Notification"));
84 			break;
85 		default:
86 			ND_PRINT((ndo, " [type=%d len=%d]", type, len));
87 			break;
88 		}
89 		sp += (len - 3);
90 		length -= (len - 3);
91 	}
92 	return;
93 trunc:
94 	ND_PRINT((ndo, " [|msdp]"));
95 }
96 
97 /*
98  * Local Variables:
99  * c-style: whitesmith
100  * c-basic-offset: 8
101  * End:
102  */
103