xref: /freebsd/contrib/tcpdump/print-vxlan.c (revision 595e514d0df2bac5b813d35f83e32875dbf16a83)
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 #ifdef HAVE_CONFIG_H
17 #include "config.h"
18 #endif
19 
20 #include <tcpdump-stdinc.h>
21 
22 #include <stdio.h>
23 #include <stdlib.h>
24 
25 #include "interface.h"
26 #include "extract.h"
27 #include "addrtoname.h"
28 
29 #include "udp.h"
30 
31 /*
32  * VXLAN header, draft-mahalingam-dutt-dcops-vxlan-03
33  *
34  *     0                   1                   2                   3
35  *     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
36  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
37  *    |R|R|R|R|I|R|R|R|            Reserved                           |
38  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
40  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41  */
42 
43 void
44 vxlan_print(const u_char *bp, u_int len)
45 {
46     u_int8_t flags;
47     u_int32_t vni;
48 
49     if (len < 8) {
50         printf("[|VXLAN]");
51         return;
52     }
53 
54     flags = *bp;
55     bp += 4;
56 
57     vni = EXTRACT_24BITS(bp);
58     bp += 4;
59 
60     printf("VXLAN, ");
61 
62     fputs("flags [", stdout);
63     if (flags & 0x08)
64         fputs("I", stdout);
65     else
66         fputs(".", stdout);
67     fputs("] ", stdout);
68 
69     printf("(0x%02x), ", flags);
70     printf("vni %u\n", vni);
71 
72     ether_print(gndo, bp, len - 8, len - 8, NULL, NULL);
73     return;
74 }
75