xref: /freebsd/contrib/tcpdump/print-vxlan-gpe.c (revision dab59af3bcc7cb7ba01569d3044894b3e860ad56)
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
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