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 * VXLAN header, RFC7348
28 * Virtual eXtensible Local Area Network (VXLAN): A Framework
29 * for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
30 *
31 * 0 1 2 3
32 * 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
33 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
34 * |R|R|R|R|I|R|R|R| Reserved |
35 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
36 * | VXLAN Network Identifier (VNI) | Reserved |
37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38 */
39
40 void
vxlan_print(netdissect_options * ndo,const u_char * bp,u_int len)41 vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
42 {
43 uint8_t flags;
44 uint32_t vni;
45
46 if (len < 8) {
47 ND_PRINT((ndo, "[|VXLAN]"));
48 return;
49 }
50
51 flags = *bp;
52 bp += 4;
53
54 vni = EXTRACT_24BITS(bp);
55 bp += 4;
56
57 ND_PRINT((ndo, "VXLAN, "));
58 ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
59 ND_PRINT((ndo, "vni %u\n", vni));
60
61 ether_print(ndo, bp, len - 8, len - 8, NULL, NULL);
62 }
63