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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 /* \summary: Multicast Source Discovery Protocol (MSDP) printer */
20 
21 #ifdef HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24 
25 #include <netdissect-stdinc.h>
26 
27 #include "netdissect.h"
28 #include "addrtoname.h"
29 #include "extract.h"
30 
31 #define MSDP_TYPE_MAX	7
32 
33 void
msdp_print(netdissect_options * ndo,const u_char * sp,u_int length)34 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
35 {
36 	unsigned int type, len;
37 
38 	ND_TCHECK2(*sp, 3);
39 	/* See if we think we're at the beginning of a compound packet */
40 	type = *sp;
41 	len = EXTRACT_16BITS(sp + 1);
42 	if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
43 		goto trunc;	/* not really truncated, but still not decodable */
44 	ND_PRINT((ndo, " msdp:"));
45 	while (length > 0) {
46 		ND_TCHECK2(*sp, 3);
47 		type = *sp;
48 		len = EXTRACT_16BITS(sp + 1);
49 		if (len > 1400 || ndo->ndo_vflag)
50 			ND_PRINT((ndo, " [len %u]", len));
51 		if (len < 3)
52 			goto trunc;
53 		sp += 3;
54 		length -= 3;
55 		switch (type) {
56 		case 1:	/* IPv4 Source-Active */
57 		case 3: /* IPv4 Source-Active Response */
58 			if (type == 1)
59 				ND_PRINT((ndo, " SA"));
60 			else
61 				ND_PRINT((ndo, " SA-Response"));
62 			ND_TCHECK(*sp);
63 			ND_PRINT((ndo, " %u entries", *sp));
64 			if ((u_int)((*sp * 12) + 8) < len) {
65 				ND_PRINT((ndo, " [w/data]"));
66 				if (ndo->ndo_vflag > 1) {
67 					ND_PRINT((ndo, " "));
68 					ip_print(ndo, sp + *sp * 12 + 8 - 3,
69 					         len - (*sp * 12 + 8));
70 				}
71 			}
72 			break;
73 		case 2:
74 			ND_PRINT((ndo, " SA-Request"));
75 			ND_TCHECK2(*sp, 5);
76 			ND_PRINT((ndo, " for %s", ipaddr_string(ndo, sp + 1)));
77 			break;
78 		case 4:
79 			ND_PRINT((ndo, " Keepalive"));
80 			if (len != 3)
81 				ND_PRINT((ndo, "[len=%d] ", len));
82 			break;
83 		case 5:
84 			ND_PRINT((ndo, " Notification"));
85 			break;
86 		default:
87 			ND_PRINT((ndo, " [type=%d len=%d]", type, len));
88 			break;
89 		}
90 		sp += (len - 3);
91 		length -= (len - 3);
92 	}
93 	return;
94 trunc:
95 	ND_PRINT((ndo, " [|msdp]"));
96 }
97 
98 /*
99  * Local Variables:
100  * c-style: whitesmith
101  * c-basic-offset: 8
102  * End:
103  */
104