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: Virtual eXtensible Local Area Network (VXLAN) printer */
17
18 /* specification: RFC 7348 */
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 static const char tstr[] = " [|VXLAN]";
30
31 #define VXLAN_HDR_LEN 8
32
33 /*
34 * VXLAN header, RFC7348
35 * Virtual eXtensible Local Area Network (VXLAN): A Framework
36 * for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
37 *
38 * 0 1 2 3
39 * 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
40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41 * |R|R|R|R|I|R|R|R| Reserved |
42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43 * | VXLAN Network Identifier (VNI) | Reserved |
44 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45 */
46
47 void
vxlan_print(netdissect_options * ndo,const u_char * bp,u_int len)48 vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
49 {
50 uint8_t flags;
51 uint32_t vni;
52
53 if (len < VXLAN_HDR_LEN)
54 goto trunc;
55
56 ND_TCHECK2(*bp, VXLAN_HDR_LEN);
57
58 flags = *bp;
59 bp += 4;
60
61 vni = EXTRACT_24BITS(bp);
62 bp += 4;
63
64 ND_PRINT((ndo, "VXLAN, "));
65 ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
66 ND_PRINT((ndo, "vni %u\n", vni));
67
68 ether_print(ndo, bp, len - VXLAN_HDR_LEN, ndo->ndo_snapend - bp, NULL, NULL);
69
70 return;
71
72 trunc:
73 ND_PRINT((ndo, "%s", tstr));
74 }
75