xref: /freebsd/contrib/tcpdump/print-vxlan-gpe.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
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
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