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
41void
42otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
43{
44    uint8_t flags;
45
46    ND_PRINT((ndo, "OTV, "));
47    if (len < 8)
48        goto trunc;
49
50    ND_TCHECK(*bp);
51    flags = *bp;
52    ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
53    bp += 1;
54
55    ND_TCHECK2(*bp, 3);
56    ND_PRINT((ndo, "overlay %u, ", EXTRACT_24BITS(bp)));
57    bp += 3;
58
59    ND_TCHECK2(*bp, 3);
60    ND_PRINT((ndo, "instance %u\n", EXTRACT_24BITS(bp)));
61    bp += 3;
62
63    /* Reserved */
64    ND_TCHECK(*bp);
65    bp += 1;
66
67    ether_print(ndo, bp, len - 8, ndo->ndo_snapend - bp, NULL, NULL);
68    return;
69
70trunc:
71    ND_PRINT((ndo, " [|OTV]"));
72}
73