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 ndo->ndo_protocol = "msdp";
39 ND_PRINT(": ");
40 nd_print_protocol(ndo);
41 /* See if we think we're at the beginning of a compound packet */
42 type = GET_U_1(sp);
43 len = GET_BE_U_2(sp + 1);
44 if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
45 goto trunc; /* not really truncated, but still not decodable */
46 while (length != 0) {
47 type = GET_U_1(sp);
48 len = GET_BE_U_2(sp + 1);
49 if (len > 1400 || ndo->ndo_vflag)
50 ND_PRINT(" [len %u]", len);
51 if (len < 3)
52 goto trunc;
53 if (length < len)
54 goto trunc;
55 sp += 3;
56 length -= 3;
57 switch (type) {
58 case 1: /* IPv4 Source-Active */
59 case 3: /* IPv4 Source-Active Response */
60 if (type == 1)
61 ND_PRINT(" SA");
62 else
63 ND_PRINT(" SA-Response");
64 ND_PRINT(" %u entries", GET_U_1(sp));
65 if ((u_int)((GET_U_1(sp) * 12) + 8) < len) {
66 ND_PRINT(" [w/data]");
67 if (ndo->ndo_vflag > 1) {
68 ND_PRINT(" ");
69 ip_print(ndo, sp +
70 GET_U_1(sp) * 12 + 8 - 3,
71 len - (GET_U_1(sp) * 12 + 8));
72 }
73 }
74 break;
75 case 2:
76 ND_PRINT(" SA-Request");
77 ND_PRINT(" for %s", GET_IPADDR_STRING(sp + 1));
78 break;
79 case 4:
80 ND_PRINT(" Keepalive");
81 if (len != 3)
82 ND_PRINT("[len=%u] ", len);
83 break;
84 case 5:
85 ND_PRINT(" Notification");
86 break;
87 default:
88 ND_PRINT(" [type=%u len=%u]", type, len);
89 break;
90 }
91 sp += (len - 3);
92 length -= (len - 3);
93 }
94 return;
95 trunc:
96 nd_print_trunc(ndo);
97 }
98