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-01 */
27
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <netdissect-stdinc.h>
33
34 #include "netdissect.h"
35 #include "extract.h"
36
37 static const char tstr[] = " [|VXLAN-GPE]";
38 static const struct tok vxlan_gpe_flags [] = {
39 { 0x08, "I" },
40 { 0x04, "P" },
41 { 0x01, "O" },
42 { 0, NULL }
43 };
44
45 #define VXLAN_GPE_HDR_LEN 8
46
47 /*
48 * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
49 * Generic Protocol Extension for VXLAN
50 *
51 * 0 1 2 3
52 * 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
53 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
54 * |R|R|Ver|I|P|R|O| Reserved |Next Protocol |
55 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
56 * | VXLAN Network Identifier (VNI) | Reserved |
57 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58 */
59
60 void
vxlan_gpe_print(netdissect_options * ndo,const u_char * bp,u_int len)61 vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
62 {
63 uint8_t flags;
64 uint8_t next_protocol;
65 uint32_t vni;
66
67 if (len < VXLAN_GPE_HDR_LEN)
68 goto trunc;
69
70 ND_TCHECK2(*bp, VXLAN_GPE_HDR_LEN);
71
72 flags = *bp;
73 bp += 3;
74
75 next_protocol = *bp;
76 bp += 1;
77
78 vni = EXTRACT_24BITS(bp);
79 bp += 4;
80
81 ND_PRINT((ndo, "VXLAN-GPE, "));
82 ND_PRINT((ndo, "flags [%s], ",
83 bittok2str_nosep(vxlan_gpe_flags, "none", flags)));
84 ND_PRINT((ndo, "vni %u", vni));
85 ND_PRINT((ndo, ndo->ndo_vflag ? "\n " : ": "));
86
87 switch (next_protocol) {
88 case 0x1:
89 ip_print(ndo, bp, len - 8);
90 break;
91 case 0x2:
92 ip6_print(ndo, bp, len - 8);
93 break;
94 case 0x3:
95 ether_print(ndo, bp, len - 8, ndo->ndo_snapend - bp, NULL, NULL);
96 break;
97 case 0x4:
98 nsh_print(ndo, bp, len - 8);
99 break;
100 case 0x5:
101 mpls_print(ndo, bp, len - 8);
102 break;
103 default:
104 ND_PRINT((ndo, "ERROR: unknown-next-protocol"));
105 return;
106 }
107
108 return;
109
110 trunc:
111 ND_PRINT((ndo, "%s", tstr));
112 }
113
114