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 #include <sys/cdefs.h>
20 #ifndef lint
21 __RCSID("$NetBSD: print-msdp.c,v 1.8 2024/09/02 16:15:32 christos Exp $");
22 #endif
23
24 /* \summary: Multicast Source Discovery Protocol (MSDP) printer */
25
26 #include <config.h>
27
28 #include "netdissect-stdinc.h"
29
30 #include "netdissect.h"
31 #include "addrtoname.h"
32 #include "extract.h"
33
34 #define MSDP_TYPE_MAX 7
35
36 void
msdp_print(netdissect_options * ndo,const u_char * sp,u_int length)37 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
38 {
39 unsigned int type, len;
40
41 ndo->ndo_protocol = "msdp";
42 ND_PRINT(": ");
43 nd_print_protocol(ndo);
44 /* See if we think we're at the beginning of a compound packet */
45 type = GET_U_1(sp);
46 len = GET_BE_U_2(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 while (length != 0) {
50 type = GET_U_1(sp);
51 len = GET_BE_U_2(sp + 1);
52 if (len > 1400 || ndo->ndo_vflag)
53 ND_PRINT(" [len %u]", len);
54 if (len < 3)
55 goto trunc;
56 if (length < len)
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 ND_PRINT(" SA");
65 else
66 ND_PRINT(" SA-Response");
67 ND_PRINT(" %u entries", GET_U_1(sp));
68 if ((u_int)((GET_U_1(sp) * 12) + 8) < len) {
69 ND_PRINT(" [w/data]");
70 if (ndo->ndo_vflag > 1) {
71 ND_PRINT(" ");
72 ip_print(ndo, sp +
73 GET_U_1(sp) * 12 + 8 - 3,
74 len - (GET_U_1(sp) * 12 + 8));
75 }
76 }
77 break;
78 case 2:
79 ND_PRINT(" SA-Request");
80 ND_PRINT(" for %s", GET_IPADDR_STRING(sp + 1));
81 break;
82 case 4:
83 ND_PRINT(" Keepalive");
84 if (len != 3)
85 ND_PRINT("[len=%u] ", len);
86 break;
87 case 5:
88 ND_PRINT(" Notification");
89 break;
90 default:
91 ND_PRINT(" [type=%u len=%u]", type, len);
92 break;
93 }
94 sp += (len - 3);
95 length -= (len - 3);
96 }
97 return;
98 trunc:
99 nd_print_trunc(ndo);
100 }
101