xref: /netbsd-src/external/bsd/tcpdump/dist/print-otv.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
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 #include <sys/cdefs.h>
17 #ifndef lint
18 __RCSID("$NetBSD: print-otv.c,v 1.3 2017/02/05 04:05:05 spz Exp $");
19 #endif
20 
21 /* \summary: Overlay Transport Virtualization (OTV) printer */
22 
23 /* specification: draft-hasmit-otv-04 */
24 
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28 
29 #include <netdissect-stdinc.h>
30 
31 #include "netdissect.h"
32 #include "extract.h"
33 
34 /*
35  * OTV header, draft-hasmit-otv-04
36  *
37  *     0                   1                   2                   3
38  *     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
39  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40  *     |R|R|R|R|I|R|R|R|           Overlay ID                          |
41  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42  *     |          Instance ID                          | Reserved      |
43  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44  */
45 
46 void
47 otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
48 {
49     uint8_t flags;
50 
51     ND_PRINT((ndo, "OTV, "));
52     if (len < 8)
53         goto trunc;
54 
55     ND_TCHECK(*bp);
56     flags = *bp;
57     ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
58     bp += 1;
59 
60     ND_TCHECK2(*bp, 3);
61     ND_PRINT((ndo, "overlay %u, ", EXTRACT_24BITS(bp)));
62     bp += 3;
63 
64     ND_TCHECK2(*bp, 3);
65     ND_PRINT((ndo, "instance %u\n", EXTRACT_24BITS(bp)));
66     bp += 3;
67 
68     /* Reserved */
69     ND_TCHECK(*bp);
70     bp += 1;
71 
72     ether_print(ndo, bp, len - 8, ndo->ndo_snapend - bp, NULL, NULL);
73     return;
74 
75 trunc:
76     ND_PRINT((ndo, " [|OTV]"));
77 }
78