The Tcpdump Group git mirrors - tcpdump/blob - print-msdp.c

   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 #include <config.h>
  22
  23 #include "netdissect-stdinc.h"
  24
  25 #define ND_LONGJMP_FROM_TCHECK
  26 #include "netdissect.h"
  27 #include "addrtoname.h"
  28 #include "extract.h"
  29
  30 #define MSDP_TYPE_MAX   7
  31
  32 void
  33 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
  34 {
  35         unsigned int type, len;
  36
  37         ndo->ndo_protocol = "msdp";
  38         ND_PRINT(": ");
  39         nd_print_protocol(ndo);
  40         /* See if we think we're at the beginning of a compound packet */
  41         type = GET_U_1(sp);
  42         len = GET_BE_U_2(sp + 1);
  43         ND_ICHECK_U(len, >, 1500);
  44         ND_ICHECK_U(len, <, 3);
  45         ND_ICHECK_U(type, ==, 0);
  46         ND_ICHECK_U(type, >, MSDP_TYPE_MAX);
  47         while (length != 0) {
  48                 unsigned int entry_count;
  49
  50                 ND_ICHECK_U(length, <, 3);
  51                 type = GET_U_1(sp);
  52                 len = GET_BE_U_2(sp + 1);
  53                 if (len > 1400 || ndo->ndo_vflag)
  54                         ND_PRINT(" [len %u]", len);
  55                 ND_ICHECK_U(len, <, 3);
  56                 ND_ICHECK_U(length, <, len);
  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
  65                         /* Entry Count */
  66                         ND_ICHECK_U(len, <, 4);
  67                         entry_count = GET_U_1(sp + 3);
  68                         ND_PRINT(" %u entries", entry_count);
  69
  70                         /* RP Address */
  71                         ND_ICHECK_U(len, <, 8);
  72                         /* XXX -print this based on ndo_vflag? */
  73                         ND_TCHECK_4(sp + 4);
  74
  75                         /* Entries */
  76                         ND_TCHECK_LEN(sp + 8, entry_count*12);
  77
  78                         if (len > (8 + entry_count*12)) {
  79                                 /* Encapsulated IP packet */
  80                                 ND_PRINT(" [w/data]");
  81                                 if (ndo->ndo_vflag > 1) {
  82                                         ND_PRINT(" ");
  83                                         ip_print(ndo, sp + (8 + entry_count*12),
  84                                             len - (8 + entry_count*12));
  85                                 }
  86                         }
  87                         break;
  88                 case 2:
  89                         /* draft-ietf-msdp-spec-13 */
  90                         ND_PRINT(" SA-Request");
  91
  92                         /* Reserved */
  93                         ND_ICHECK_U(len, <, 4);
  94                         ND_TCHECK_1(sp + 3);
  95
  96                         /* Group Address */
  97                         ND_ICHECK_U(len, <, 8);
  98                         if (len != 8)
  99                                 ND_PRINT("[len=%u] ", len);
 100                         ND_PRINT(" for %s", GET_IPADDR_STRING(sp + 4));
 101                         break;
 102                 case 4:
 103                         ND_PRINT(" Keepalive");
 104                         if (len != 3)
 105                                 ND_PRINT("[len=%u] ", len);
 106                         break;
 107                 case 5:
 108                         ND_PRINT(" Notification");
 109                         break;
 110                 default:
 111                         ND_PRINT(" [type=%u len=%u]", type, len);
 112                         break;
 113                 }
 114                 ND_TCHECK_LEN(sp, len);
 115                 sp += len;
 116                 length -= len;
 117         }
 118         return;
 119
 120 invalid:
 121    nd_print_invalid(ndo);
 122
 123 }