external/bsd/tcpdump/dist/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, RFC7348
  28  *               Virtual eXtensible Local Area Network (VXLAN): A Framework
  29  *               for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
  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(netdissect_options *ndo, const u_char *bp, u_int len)
  42 {
  43     uint8_t flags;
  44     uint32_t vni;
  45
  46     if (len < 8) {
  47         ND_PRINT((ndo, "[|VXLAN]"));
  48         return;
  49     }
  50
  51     flags = *bp;
  52     bp += 4;
  53
  54     vni = EXTRACT_24BITS(bp);
  55     bp += 4;
  56
  57     ND_PRINT((ndo, "VXLAN, "));
  58     ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
  59     ND_PRINT((ndo, "vni %u\n", vni));
  60
  61     ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
  62 }