xref: /netbsd-src/external/bsd/tcpdump/dist/print-vxlan-gpe.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
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 #include <sys/cdefs.h>
25 #ifndef lint
26 __RCSID("$NetBSD: print-vxlan-gpe.c,v 1.4 2023/08/17 20:19:40 christos Exp $");
27 #endif
28 
29 /* \summary: Generic Protocol Extension for VXLAN (VXLAN GPE) printer */
30 
31 /* specification: draft-ietf-nvo3-vxlan-gpe-10 */
32 
33 #ifdef HAVE_CONFIG_H
34 #include <config.h>
35 #endif
36 
37 #include "netdissect-stdinc.h"
38 
39 #define ND_LONGJMP_FROM_TCHECK
40 #include "netdissect.h"
41 #include "extract.h"
42 
43 static const struct tok vxlan_gpe_flags [] = {
44     { 0x08, "I" },
45     { 0x04, "P" },
46     { 0x02, "B" },
47     { 0x01, "O" },
48     { 0, NULL }
49 };
50 
51 #define VXLAN_GPE_HDR_LEN 8
52 
53 /*
54  * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
55  *                   Generic Protocol Extension for VXLAN
56  *
57  *     0                   1                   2                   3
58  *     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
59  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60  *    |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
61  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
63  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
64  */
65 
66 void
67 vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
68 {
69     uint8_t flags;
70     uint8_t next_protocol;
71     uint32_t vni;
72 
73     ndo->ndo_protocol = "vxlan_gpe";
74     ND_PRINT("VXLAN-GPE, ");
75     if (len < VXLAN_GPE_HDR_LEN) {
76         ND_PRINT(" (len %u < %u)", len, VXLAN_GPE_HDR_LEN);
77         goto invalid;
78     }
79 
80     flags = GET_U_1(bp);
81     bp += 1;
82     len -= 1;
83     ND_PRINT("flags [%s], ",
84               bittok2str_nosep(vxlan_gpe_flags, "none", flags));
85 
86     /* Reserved */
87     bp += 2;
88     len -= 2;
89 
90     next_protocol = GET_U_1(bp);
91     bp += 1;
92     len -= 1;
93 
94     vni = GET_BE_U_3(bp);
95     bp += 3;
96     len -= 3;
97 
98     /* Reserved */
99     ND_TCHECK_1(bp);
100     bp += 1;
101     len -= 1;
102 
103     ND_PRINT("vni %u", vni);
104     ND_PRINT(ndo->ndo_vflag ? "\n    " : ": ");
105 
106     switch (next_protocol) {
107     case 0x1:
108         ip_print(ndo, bp, len);
109         break;
110     case 0x2:
111         ip6_print(ndo, bp, len);
112         break;
113     case 0x3:
114         ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
115         break;
116     case 0x4:
117         nsh_print(ndo, bp, len);
118         break;
119     default:
120         ND_PRINT("ERROR: unknown-next-protocol");
121         goto invalid;
122     }
123 
124 	return;
125 
126 invalid:
127     nd_print_invalid(ndo);
128 }
129 
130