1/* Copyright (c) 2015, bugyo
2 * All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 * 1. Redistributions of source code must retain the above copyright notice,
7 *    this list of conditions and the following disclaimer.
8 * 2. Redistributions in binary form must reproduce the above copyright notice,
9 *    this list of conditions and the following disclaimer in the documentation
10 *    and/or other materials provided with the distribution.
11 *
12 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
13 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
14 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
15 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
16 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
17 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
18 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
19 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
20 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
21 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22 */
23
24/* \summary: Generic Protocol Extension for VXLAN (VXLAN GPE) printer */
25
26/* specification: draft-ietf-nvo3-vxlan-gpe-10 */
27
28#ifdef HAVE_CONFIG_H
29#include <config.h>
30#endif
31
32#include "netdissect-stdinc.h"
33
34#define ND_LONGJMP_FROM_TCHECK
35#include "netdissect.h"
36#include "extract.h"
37
38static const struct tok vxlan_gpe_flags [] = {
39    { 0x08, "I" },
40    { 0x04, "P" },
41    { 0x02, "B" },
42    { 0x01, "O" },
43    { 0, NULL }
44};
45
46#define VXLAN_GPE_HDR_LEN 8
47
48/*
49 * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
50 *                   Generic Protocol Extension for VXLAN
51 *
52 *     0                   1                   2                   3
53 *     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
54 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
55 *    |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
56 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
57 *    |                VXLAN Network Identifier (VNI) |   Reserved    |
58 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
59 */
60
61void
62vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
63{
64    uint8_t flags;
65    uint8_t next_protocol;
66    uint32_t vni;
67
68    ndo->ndo_protocol = "vxlan_gpe";
69    ND_PRINT("VXLAN-GPE, ");
70    if (len < VXLAN_GPE_HDR_LEN) {
71        ND_PRINT(" (len %u < %u)", len, VXLAN_GPE_HDR_LEN);
72        goto invalid;
73    }
74
75    flags = GET_U_1(bp);
76    bp += 1;
77    len -= 1;
78    ND_PRINT("flags [%s], ",
79              bittok2str_nosep(vxlan_gpe_flags, "none", flags));
80
81    /* Reserved */
82    bp += 2;
83    len -= 2;
84
85    next_protocol = GET_U_1(bp);
86    bp += 1;
87    len -= 1;
88
89    vni = GET_BE_U_3(bp);
90    bp += 3;
91    len -= 3;
92
93    /* Reserved */
94    ND_TCHECK_1(bp);
95    bp += 1;
96    len -= 1;
97
98    ND_PRINT("vni %u", vni);
99    ND_PRINT(ndo->ndo_vflag ? "\n    " : ": ");
100
101    switch (next_protocol) {
102    case 0x1:
103        ip_print(ndo, bp, len);
104        break;
105    case 0x2:
106        ip6_print(ndo, bp, len);
107        break;
108    case 0x3:
109        ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
110        break;
111    case 0x4:
112        nsh_print(ndo, bp, len);
113        break;
114    default:
115        ND_PRINT("ERROR: unknown-next-protocol");
116        goto invalid;
117    }
118
119	return;
120
121invalid:
122    nd_print_invalid(ndo);
123}
124
125