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 #include <config.h>
29
30 #include "netdissect-stdinc.h"
31
32 #define ND_LONGJMP_FROM_TCHECK
33 #include "netdissect.h"
34 #include "extract.h"
35
36 static const struct tok vxlan_gpe_flags [] = {
37 { 0x08, "I" },
38 { 0x04, "P" },
39 { 0x02, "B" },
40 { 0x01, "O" },
41 { 0, NULL }
42 };
43
44 #define VXLAN_GPE_HDR_LEN 8
45
46 /*
47 * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
48 * Generic Protocol Extension for VXLAN
49 *
50 * 0 1 2 3
51 * 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
52 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
53 * |R|R|Ver|I|P|R|O| Reserved |Next Protocol |
54 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
55 * | VXLAN Network Identifier (VNI) | Reserved |
56 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
57 */
58
59 void
vxlan_gpe_print(netdissect_options * ndo,const u_char * bp,u_int len)60 vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
61 {
62 uint8_t flags;
63 uint8_t next_protocol;
64 uint32_t vni;
65
66 ndo->ndo_protocol = "vxlan_gpe";
67 ND_PRINT("VXLAN-GPE, ");
68 if (len < VXLAN_GPE_HDR_LEN) {
69 ND_PRINT(" (len %u < %u)", len, VXLAN_GPE_HDR_LEN);
70 goto invalid;
71 }
72
73 flags = GET_U_1(bp);
74 bp += 1;
75 len -= 1;
76 ND_PRINT("flags [%s], ",
77 bittok2str_nosep(vxlan_gpe_flags, "none", flags));
78
79 /* Reserved */
80 bp += 2;
81 len -= 2;
82
83 next_protocol = GET_U_1(bp);
84 bp += 1;
85 len -= 1;
86
87 vni = GET_BE_U_3(bp);
88 bp += 3;
89 len -= 3;
90
91 /* Reserved */
92 ND_TCHECK_1(bp);
93 bp += 1;
94 len -= 1;
95
96 ND_PRINT("vni %u", vni);
97 ND_PRINT(ndo->ndo_vflag ? "\n " : ": ");
98
99 switch (next_protocol) {
100 case 0x1:
101 ip_print(ndo, bp, len);
102 break;
103 case 0x2:
104 ip6_print(ndo, bp, len);
105 break;
106 case 0x3:
107 ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
108 break;
109 case 0x4:
110 nsh_print(ndo, bp, len);
111 break;
112 default:
113 ND_PRINT("ERROR: unknown-next-protocol");
114 goto invalid;
115 }
116
117 return;
118
119 invalid:
120 nd_print_invalid(ndo);
121 }
122
123