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
otv_print(netdissect_options * ndo,const u_char * bp,u_int len)42 otv_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
70 trunc:
71 ND_PRINT((ndo, " [|OTV]"));
72 }
73