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 * OTV header, draft-hasmit-otv-04
28 *
29 * 0 1 2 3
30 * 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
31 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
32 * |R|R|R|R|I|R|R|R| Overlay ID |
33 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
34 * | Instance ID | Reserved |
35 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
36 */
37
38 void
otv_print(netdissect_options * ndo,const u_char * bp,u_int len)39 otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
40 {
41 uint8_t flags;
42 uint32_t overlay_id;
43 uint32_t instance_id;
44
45 if (len < 8) {
46 ND_PRINT((ndo, "[|OTV]"));
47 return;
48 }
49
50 flags = *bp;
51 bp += 1;
52
53 overlay_id = EXTRACT_24BITS(bp);
54 bp += 3;
55
56 instance_id = EXTRACT_24BITS(bp);
57 bp += 4;
58
59 ND_PRINT((ndo, "OTV, "));
60 ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
61 ND_PRINT((ndo, "overlay %u, ", overlay_id));
62 ND_PRINT((ndo, "instance %u\n", instance_id));
63
64 ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
65 }
66