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 #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 static const struct tok vxlan_flags [] = {
29 { 0x08, "I" },
30 { 0, NULL }
31 };
32 #define VXLAN_HDR_LEN 8
33
34 /*
35 * VXLAN header, RFC7348
36 * Virtual eXtensible Local Area Network (VXLAN): A Framework
37 * for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
38 *
39 * 0 1 2 3
40 * 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
41 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 * |R|R|R|R|I|R|R|R| Reserved |
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * | VXLAN Network Identifier (VNI) | Reserved |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 */
47
48 void
vxlan_print(netdissect_options * ndo,const u_char * bp,u_int len)49 vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
50 {
51 uint8_t flags;
52 uint32_t vni;
53
54 ndo->ndo_protocol = "vxlan";
55 nd_print_protocol_caps(ndo);
56 if (len < VXLAN_HDR_LEN)
57 goto invalid;
58
59 flags = GET_U_1(bp);
60 bp += 1;
61 ND_PRINT(", flags [%s] (0x%02x), ",
62 bittok2str_nosep(vxlan_flags, "invalid", flags), flags);
63
64 /* 1st Reserved */
65 bp += 3;
66
67 vni = GET_BE_U_3(bp);
68 bp += 3;
69 ND_PRINT("vni %u\n", vni);
70
71 /* 2nd Reserved */
72 ND_TCHECK_1(bp);
73 bp += 1;
74
75 ether_print(ndo, bp, len - VXLAN_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
76
77 return;
78
79 invalid:
80 nd_print_invalid(ndo);
81 }
82