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 #ifdef HAVE_CONFIG_H
  17 #include "config.h"
  18 #endif
  19
  20 #include <tcpdump-stdinc.h>
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24
  25 #include "interface.h"
  26 #include "extract.h"
  27
  28 /*
  29  * VXLAN header, draft-mahalingam-dutt-dcops-vxlan-03
  30  *
  31  *     0                   1                   2                   3
  32  *     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
  33  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  34  *    |R|R|R|R|I|R|R|R|            Reserved                           |
  35  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  36  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
  37  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  38  */
  39
  40 void
  41 vxlan_print(const u_char *bp, u_int len)
  42 {
  43     u_int8_t flags;
  44     u_int32_t vni;
  45
  46     if (len < 8) {
  47         printf("[|VXLAN]");
  48         return;
  49     }
  50
  51     flags = *bp;
  52     bp += 4;
  53
  54     vni = EXTRACT_24BITS(bp);
  55     bp += 4;
  56
  57     printf("VXLAN, ");
  58
  59     fputs("flags [", stdout);
  60     if (flags & 0x08)
  61         fputs("I", stdout);
  62     else
  63         fputs(".", stdout);
  64     fputs("] ", stdout);
  65
  66     printf("(0x%02x), ", flags);
  67     printf("vni %u\n", vni);
  68
  69     ether_print(gndo, bp, len - 8, len - 8, NULL, NULL);
  70     return;
  71 }