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