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

   1 /*
   2  * Redistribution and use in source and binary forms, with or without
   3  * modification, are permitted provided that: (1) source code
   4  * distributions retain the above copyright notice and this paragraph
   5  * in its entirety, and (2) distributions including binary code include
   6  * the above copyright notice and this paragraph in its entirety in
   7  * the documentation or other materials provided with the distribution.
   8  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
   9  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  10  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  11  * FOR A PARTICULAR PURPOSE.
  12  *
  13  * Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
  14  */
  15
  16 #define NETDISSECT_REWORKED
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <tcpdump-stdinc.h>
  22
  23 #include "interface.h"
  24 #include "extract.h"
  25
  26 /*
  27  * VXLAN header, draft-mahalingam-dutt-dcops-vxlan-03
  28  *
  29  *     0                   1                   2                   3
  30  *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  31  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  32  *    |R|R|R|R|I|R|R|R|            Reserved                           |
  33  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
  35  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  */
  37
  38 void
  39 vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
  40 {
  41     u_int8_t flags;
  42     u_int32_t vni;
  43
  44     if (len < 8) {
  45         ND_PRINT((ndo, "[|VXLAN]"));
  46         return;
  47     }
  48
  49     flags = *bp;
  50     bp += 4;
  51
  52     vni = EXTRACT_24BITS(bp);
  53     bp += 4;
  54
  55     ND_PRINT((ndo, "VXLAN, "));
  56     ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
  57     ND_PRINT((ndo, "vni %u\n", vni));
  58
  59     ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
  60 }