xref: /aosp_15_r20/external/tcpdump/print-vxlan.c (revision 05b00f6010a2396e3db2409989fc67270046269f)
1*05b00f60SXin Li /*
2*05b00f60SXin Li  * Redistribution and use in source and binary forms, with or without
3*05b00f60SXin Li  * modification, are permitted provided that: (1) source code
4*05b00f60SXin Li  * distributions retain the above copyright notice and this paragraph
5*05b00f60SXin Li  * in its entirety, and (2) distributions including binary code include
6*05b00f60SXin Li  * the above copyright notice and this paragraph in its entirety in
7*05b00f60SXin Li  * the documentation or other materials provided with the distribution.
8*05b00f60SXin Li  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
9*05b00f60SXin Li  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
10*05b00f60SXin Li  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
11*05b00f60SXin Li  * FOR A PARTICULAR PURPOSE.
12*05b00f60SXin Li  *
13*05b00f60SXin Li  * Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
14*05b00f60SXin Li  */
15*05b00f60SXin Li 
16*05b00f60SXin Li /* \summary: Virtual eXtensible Local Area Network (VXLAN) printer */
17*05b00f60SXin Li 
18*05b00f60SXin Li /* specification: RFC 7348 */
19*05b00f60SXin Li 
20*05b00f60SXin Li #ifdef HAVE_CONFIG_H
21*05b00f60SXin Li #include <config.h>
22*05b00f60SXin Li #endif
23*05b00f60SXin Li 
24*05b00f60SXin Li #include "netdissect-stdinc.h"
25*05b00f60SXin Li 
26*05b00f60SXin Li #define ND_LONGJMP_FROM_TCHECK
27*05b00f60SXin Li #include "netdissect.h"
28*05b00f60SXin Li #include "extract.h"
29*05b00f60SXin Li 
30*05b00f60SXin Li static const struct tok vxlan_flags [] = {
31*05b00f60SXin Li     { 0x08, "I" },
32*05b00f60SXin Li     { 0, NULL }
33*05b00f60SXin Li };
34*05b00f60SXin Li #define VXLAN_HDR_LEN 8
35*05b00f60SXin Li 
36*05b00f60SXin Li /*
37*05b00f60SXin Li  * VXLAN header, RFC7348
38*05b00f60SXin Li  *               Virtual eXtensible Local Area Network (VXLAN): A Framework
39*05b00f60SXin Li  *               for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
40*05b00f60SXin Li  *
41*05b00f60SXin Li  *     0                   1                   2                   3
42*05b00f60SXin Li  *     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*05b00f60SXin Li  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44*05b00f60SXin Li  *    |R|R|R|R|I|R|R|R|            Reserved                           |
45*05b00f60SXin Li  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46*05b00f60SXin Li  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
47*05b00f60SXin Li  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48*05b00f60SXin Li  */
49*05b00f60SXin Li 
50*05b00f60SXin Li void
vxlan_print(netdissect_options * ndo,const u_char * bp,u_int len)51*05b00f60SXin Li vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
52*05b00f60SXin Li {
53*05b00f60SXin Li     uint8_t flags;
54*05b00f60SXin Li     uint32_t vni;
55*05b00f60SXin Li 
56*05b00f60SXin Li     ndo->ndo_protocol = "vxlan";
57*05b00f60SXin Li     nd_print_protocol_caps(ndo);
58*05b00f60SXin Li     if (len < VXLAN_HDR_LEN)
59*05b00f60SXin Li         goto invalid;
60*05b00f60SXin Li 
61*05b00f60SXin Li     flags = GET_U_1(bp);
62*05b00f60SXin Li     bp += 1;
63*05b00f60SXin Li     ND_PRINT(", flags [%s] (0x%02x), ",
64*05b00f60SXin Li              bittok2str_nosep(vxlan_flags, "invalid", flags), flags);
65*05b00f60SXin Li 
66*05b00f60SXin Li     /* 1st Reserved */
67*05b00f60SXin Li     bp += 3;
68*05b00f60SXin Li 
69*05b00f60SXin Li     vni = GET_BE_U_3(bp);
70*05b00f60SXin Li     bp += 3;
71*05b00f60SXin Li     ND_PRINT("vni %u\n", vni);
72*05b00f60SXin Li 
73*05b00f60SXin Li     /* 2nd Reserved */
74*05b00f60SXin Li     ND_TCHECK_1(bp);
75*05b00f60SXin Li     bp += 1;
76*05b00f60SXin Li 
77*05b00f60SXin Li     ether_print(ndo, bp, len - VXLAN_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
78*05b00f60SXin Li 
79*05b00f60SXin Li     return;
80*05b00f60SXin Li 
81*05b00f60SXin Li invalid:
82*05b00f60SXin Li     nd_print_invalid(ndo);
83*05b00f60SXin Li }
84