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#define ND_LONGJMP_FROM_TCHECK
27#include "netdissect.h"
28#include "extract.h"
29
30#define OTV_HDR_LEN 8
31
32/*
33 * OTV header, draft-hasmit-otv-04
34 *
35 *     0                   1                   2                   3
36 *     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
37 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38 *     |R|R|R|R|I|R|R|R|           Overlay ID                          |
39 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40 *     |          Instance ID                          | Reserved      |
41 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 */
43
44void
45otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
46{
47    uint8_t flags;
48
49    ndo->ndo_protocol = "otv";
50    ND_PRINT("OTV, ");
51    if (len < OTV_HDR_LEN) {
52        ND_PRINT("[length %u < %u]", len, OTV_HDR_LEN);
53        goto invalid;
54    }
55
56    flags = GET_U_1(bp);
57    ND_PRINT("flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags);
58    bp += 1;
59
60    ND_PRINT("overlay %u, ", GET_BE_U_3(bp));
61    bp += 3;
62
63    ND_PRINT("instance %u\n", GET_BE_U_3(bp));
64    bp += 3;
65
66    /* Reserved */
67    ND_TCHECK_1(bp);
68    bp += 1;
69
70    ether_print(ndo, bp, len - OTV_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
71    return;
72
73invalid:
74    nd_print_invalid(ndo);
75    ND_TCHECK_LEN(bp, len);
76}
77