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 #include <config.h>
21
22 #include "netdissect-stdinc.h"
23
24 #define ND_LONGJMP_FROM_TCHECK
25 #include "netdissect.h"
26 #include "extract.h"
27
28 #define OTV_HDR_LEN 8
29
30 /*
31 * OTV header, draft-hasmit-otv-04
32 *
33 * 0 1 2 3
34 * 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
35 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
36 * |R|R|R|R|I|R|R|R| Overlay ID |
37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38 * | Instance ID | Reserved |
39 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40 */
41
42 void
otv_print(netdissect_options * ndo,const u_char * bp,u_int len)43 otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
44 {
45 uint8_t flags;
46
47 ndo->ndo_protocol = "otv";
48 ND_PRINT("OTV, ");
49 if (len < OTV_HDR_LEN) {
50 ND_PRINT("[length %u < %u]", len, OTV_HDR_LEN);
51 goto invalid;
52 }
53
54 flags = GET_U_1(bp);
55 ND_PRINT("flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags);
56 bp += 1;
57
58 ND_PRINT("overlay %u, ", GET_BE_U_3(bp));
59 bp += 3;
60
61 ND_PRINT("instance %u\n", GET_BE_U_3(bp));
62 bp += 3;
63
64 /* Reserved */
65 ND_TCHECK_1(bp);
66 bp += 1;
67
68 ether_print(ndo, bp, len - OTV_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
69 return;
70
71 invalid:
72 nd_print_invalid(ndo);
73 ND_TCHECK_LEN(bp, len);
74 }
75