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 #ifdef HAVE_CONFIG_H
  20 #include "config.h"
  21 #endif
  22
  23 #include <tcpdump-stdinc.h>
  24
  25 #include "netdissect.h"
  26 #include "addrtoname.h"
  27 #include "extract.h"
  28
  29 #define MSDP_TYPE_MAX   7
  30
  31 void
  32 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length)
  33 {
  34         unsigned int type, len;
  35
  36         ND_TCHECK2(*sp, 3);
  37         /* See if we think we're at the beginning of a compound packet */
  38         type = *sp;
  39         len = EXTRACT_16BITS(sp + 1);
  40         if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX)
  41                 goto trunc;     /* not really truncated, but still not decodable */
  42         ND_PRINT((ndo, " msdp:"));
  43         while (length > 0) {
  44                 ND_TCHECK2(*sp, 3);
  45                 type = *sp;
  46                 len = EXTRACT_16BITS(sp + 1);
  47                 if (len > 1400 || ndo->ndo_vflag)
  48                         ND_PRINT((ndo, " [len %u]", len));
  49                 if (len < 3)
  50                         goto trunc;
  51                 sp += 3;
  52                 length -= 3;
  53                 switch (type) {
  54                 case 1: /* IPv4 Source-Active */
  55                 case 3: /* IPv4 Source-Active Response */
  56                         if (type == 1)
  57                                 ND_PRINT((ndo, " SA"));
  58                         else
  59                                 ND_PRINT((ndo, " SA-Response"));
  60                         ND_TCHECK(*sp);
  61                         ND_PRINT((ndo, " %u entries", *sp));
  62                         if ((u_int)((*sp * 12) + 8) < len) {
  63                                 ND_PRINT((ndo, " [w/data]"));
  64                                 if (ndo->ndo_vflag > 1) {
  65                                         ND_PRINT((ndo, " "));
  66                                         ip_print(ndo, sp + *sp * 12 + 8 - 3,
  67                                                  len - (*sp * 12 + 8));
  68                                 }
  69                         }
  70                         break;
  71                 case 2:
  72                         ND_PRINT((ndo, " SA-Request"));
  73                         ND_TCHECK2(*sp, 5);
  74                         ND_PRINT((ndo, " for %s", ipaddr_string(ndo, sp + 1)));
  75                         break;
  76                 case 4:
  77                         ND_PRINT((ndo, " Keepalive"));
  78                         if (len != 3)
  79                                 ND_PRINT((ndo, "[len=%d] ", len));
  80                         break;
  81                 case 5:
  82                         ND_PRINT((ndo, " Notification"));
  83                         break;
  84                 default:
  85                         ND_PRINT((ndo, " [type=%d len=%d]", type, len));
  86                         break;
  87                 }
  88                 sp += (len - 3);
  89                 length -= (len - 3);
  90         }
  91         return;
  92 trunc:
  93         ND_PRINT((ndo, " [|msdp]"));
  94 }
  95
  96 /*
  97  * Local Variables:
  98  * c-style: whitesmith
  99  * c-basic-offset: 8
 100  * End:
 101  */