tcpdump  4.99.1
About: tcpdump is a tool for network monitoring and data acquisition.
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print-msdp.c
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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
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 }
#define GET_IPADDR_STRING(p)
Definition: addrtoname.h:120
#define GET_BE_U_2(p)
Definition: extract.h:875
#define GET_U_1(p)
Definition: extract.h:872
void nd_print_protocol(netdissect_options *)
Definition: util-print.c:415
void nd_print_trunc(netdissect_options *)
Definition: util-print.c:409
void ip_print(netdissect_options *, const u_char *, u_int)
Definition: print-ip.c:319
#define ND_PRINT(...)
Definition: netdissect.h:385
void msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
Definition: print-msdp.c:34
#define MSDP_TYPE_MAX
Definition: print-msdp.c:31
const char * ndo_protocol
Definition: netdissect.h:218