The Tcpdump Group git mirrors - tcpdump/blob - print-otv.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 /* \summary: Overlay Transport Virtualization (OTV) printer */
  17
  18 /* specification: draft-hasmit-otv-04 */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <netdissect-stdinc.h>
  25
  26 #include "netdissect.h"
  27 #include "extract.h"
  28
  29 /*
  30  * OTV header, draft-hasmit-otv-04
  31  *
  32  *     0                   1                   2                   3
  33  *     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
  34  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  35  *     |R|R|R|R|I|R|R|R|           Overlay ID                          |
  36  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  37  *     |          Instance ID                          | Reserved      |
  38  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  */
  40
  41 void
  42 otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
  43 {
  44     uint8_t flags;
  45     uint32_t overlay_id;
  46     uint32_t instance_id;
  47
  48     if (len < 8) {
  49         ND_PRINT((ndo, "[|OTV]"));
  50         return;
  51     }
  52
  53     flags = *bp;
  54     bp += 1;
  55
  56     overlay_id = EXTRACT_24BITS(bp);
  57     bp += 3;
  58
  59     instance_id = EXTRACT_24BITS(bp);
  60     bp += 4;
  61
  62     ND_PRINT((ndo, "OTV, "));
  63     ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
  64     ND_PRINT((ndo, "overlay %u, ", overlay_id));
  65     ND_PRINT((ndo, "instance %u\n", instance_id));
  66
  67     ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
  68 }