xref: /netbsd-src/external/bsd/tcpdump/dist/print-vxlan-gpe.c (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
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 1.5 2024/09/02 16:15:33 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 #include <config.h>
34 
35 #include "netdissect-stdinc.h"
36 
37 #define ND_LONGJMP_FROM_TCHECK
38 #include "netdissect.h"
39 #include "extract.h"
40 
41 static const struct tok vxlan_gpe_flags [] = {
42     { 0x08, "I" },
43     { 0x04, "P" },
44     { 0x02, "B" },
45     { 0x01, "O" },
46     { 0, NULL }
47 };
48 
49 #define VXLAN_GPE_HDR_LEN 8
50 
51 /*
52  * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
53  *                   Generic Protocol Extension for VXLAN
54  *
55  *     0                   1                   2                   3
56  *     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
57  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58  *    |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
59  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
61  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62  */
63 
64 void
65 vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
66 {
67     uint8_t flags;
68     uint8_t next_protocol;
69     uint32_t vni;
70 
71     ndo->ndo_protocol = "vxlan_gpe";
72     ND_PRINT("VXLAN-GPE, ");
73     if (len < VXLAN_GPE_HDR_LEN) {
74         ND_PRINT(" (len %u < %u)", len, VXLAN_GPE_HDR_LEN);
75         goto invalid;
76     }
77 
78     flags = GET_U_1(bp);
79     bp += 1;
80     len -= 1;
81     ND_PRINT("flags [%s], ",
82               bittok2str_nosep(vxlan_gpe_flags, "none", flags));
83 
84     /* Reserved */
85     bp += 2;
86     len -= 2;
87 
88     next_protocol = GET_U_1(bp);
89     bp += 1;
90     len -= 1;
91 
92     vni = GET_BE_U_3(bp);
93     bp += 3;
94     len -= 3;
95 
96     /* Reserved */
97     ND_TCHECK_1(bp);
98     bp += 1;
99     len -= 1;
100 
101     ND_PRINT("vni %u", vni);
102     ND_PRINT(ndo->ndo_vflag ? "\n    " : ": ");
103 
104     switch (next_protocol) {
105     case 0x1:
106         ip_print(ndo, bp, len);
107         break;
108     case 0x2:
109         ip6_print(ndo, bp, len);
110         break;
111     case 0x3:
112         ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
113         break;
114     case 0x4:
115         nsh_print(ndo, bp, len);
116         break;
117     default:
118         ND_PRINT("ERROR: unknown-next-protocol");
119         goto invalid;
120     }
121 
122 	return;
123 
124 invalid:
125     nd_print_invalid(ndo);
126 }
127 
128