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 #define ND_LONGJMP_FROM_TCHECK
27 #include "netdissect.h"
28 #include "extract.h"
29
30 static const struct tok vxlan_flags [] = {
31 { 0x08, "I" },
32 { 0, NULL }
33 };
34 #define VXLAN_HDR_LEN 8
35
36 /*
37 * VXLAN header, RFC7348
38 * Virtual eXtensible Local Area Network (VXLAN): A Framework
39 * for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
40 *
41 * 0 1 2 3
42 * 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
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * |R|R|R|R|I|R|R|R| Reserved |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 * | VXLAN Network Identifier (VNI) | Reserved |
47 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 */
49
50 void
vxlan_print(netdissect_options * ndo,const u_char * bp,u_int len)51 vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
52 {
53 uint8_t flags;
54 uint32_t vni;
55
56 ndo->ndo_protocol = "vxlan";
57 nd_print_protocol_caps(ndo);
58 if (len < VXLAN_HDR_LEN)
59 goto invalid;
60
61 flags = GET_U_1(bp);
62 bp += 1;
63 ND_PRINT(", flags [%s] (0x%02x), ",
64 bittok2str_nosep(vxlan_flags, "invalid", flags), flags);
65
66 /* 1st Reserved */
67 bp += 3;
68
69 vni = GET_BE_U_3(bp);
70 bp += 3;
71 ND_PRINT("vni %u\n", vni);
72
73 /* 2nd Reserved */
74 ND_TCHECK_1(bp);
75 bp += 1;
76
77 ether_print(ndo, bp, len - VXLAN_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
78
79 return;
80
81 invalid:
82 nd_print_invalid(ndo);
83 }
84