xref: /aosp_15_r20/external/tcpdump/print-otv.c (revision 05b00f6010a2396e3db2409989fc67270046269f)
1*05b00f60SXin Li /*
2*05b00f60SXin Li  * Redistribution and use in source and binary forms, with or without
3*05b00f60SXin Li  * modification, are permitted provided that: (1) source code
4*05b00f60SXin Li  * distributions retain the above copyright notice and this paragraph
5*05b00f60SXin Li  * in its entirety, and (2) distributions including binary code include
6*05b00f60SXin Li  * the above copyright notice and this paragraph in its entirety in
7*05b00f60SXin Li  * the documentation or other materials provided with the distribution.
8*05b00f60SXin Li  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
9*05b00f60SXin Li  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
10*05b00f60SXin Li  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
11*05b00f60SXin Li  * FOR A PARTICULAR PURPOSE.
12*05b00f60SXin Li  *
13*05b00f60SXin Li  * Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
14*05b00f60SXin Li  */
15*05b00f60SXin Li 
16*05b00f60SXin Li /* \summary: Overlay Transport Virtualization (OTV) printer */
17*05b00f60SXin Li 
18*05b00f60SXin Li /* specification: draft-hasmit-otv-04 */
19*05b00f60SXin Li 
20*05b00f60SXin Li #ifdef HAVE_CONFIG_H
21*05b00f60SXin Li #include <config.h>
22*05b00f60SXin Li #endif
23*05b00f60SXin Li 
24*05b00f60SXin Li #include "netdissect-stdinc.h"
25*05b00f60SXin Li 
26*05b00f60SXin Li #define ND_LONGJMP_FROM_TCHECK
27*05b00f60SXin Li #include "netdissect.h"
28*05b00f60SXin Li #include "extract.h"
29*05b00f60SXin Li 
30*05b00f60SXin Li #define OTV_HDR_LEN 8
31*05b00f60SXin Li 
32*05b00f60SXin Li /*
33*05b00f60SXin Li  * OTV header, draft-hasmit-otv-04
34*05b00f60SXin Li  *
35*05b00f60SXin Li  *     0                   1                   2                   3
36*05b00f60SXin Li  *     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
37*05b00f60SXin Li  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38*05b00f60SXin Li  *     |R|R|R|R|I|R|R|R|           Overlay ID                          |
39*05b00f60SXin Li  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40*05b00f60SXin Li  *     |          Instance ID                          | Reserved      |
41*05b00f60SXin Li  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42*05b00f60SXin Li  */
43*05b00f60SXin Li 
44*05b00f60SXin Li void
otv_print(netdissect_options * ndo,const u_char * bp,u_int len)45*05b00f60SXin Li otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
46*05b00f60SXin Li {
47*05b00f60SXin Li     uint8_t flags;
48*05b00f60SXin Li 
49*05b00f60SXin Li     ndo->ndo_protocol = "otv";
50*05b00f60SXin Li     ND_PRINT("OTV, ");
51*05b00f60SXin Li     if (len < OTV_HDR_LEN) {
52*05b00f60SXin Li         ND_PRINT("[length %u < %u]", len, OTV_HDR_LEN);
53*05b00f60SXin Li         goto invalid;
54*05b00f60SXin Li     }
55*05b00f60SXin Li 
56*05b00f60SXin Li     flags = GET_U_1(bp);
57*05b00f60SXin Li     ND_PRINT("flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags);
58*05b00f60SXin Li     bp += 1;
59*05b00f60SXin Li 
60*05b00f60SXin Li     ND_PRINT("overlay %u, ", GET_BE_U_3(bp));
61*05b00f60SXin Li     bp += 3;
62*05b00f60SXin Li 
63*05b00f60SXin Li     ND_PRINT("instance %u\n", GET_BE_U_3(bp));
64*05b00f60SXin Li     bp += 3;
65*05b00f60SXin Li 
66*05b00f60SXin Li     /* Reserved */
67*05b00f60SXin Li     ND_TCHECK_1(bp);
68*05b00f60SXin Li     bp += 1;
69*05b00f60SXin Li 
70*05b00f60SXin Li     ether_print(ndo, bp, len - OTV_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
71*05b00f60SXin Li     return;
72*05b00f60SXin Li 
73*05b00f60SXin Li invalid:
74*05b00f60SXin Li     nd_print_invalid(ndo);
75*05b00f60SXin Li     ND_TCHECK_LEN(bp, len);
76*05b00f60SXin Li }
77