xref: /openbsd/usr.sbin/tcpdump/print-udpencap.c (revision d89ec533)
1 /*	$OpenBSD: print-udpencap.c,v 1.7 2020/01/24 22:46:37 procter Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Markus Friedl.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/types.h>
28 #include <stdio.h>
29 
30 #include "interface.h"
31 
32 void
33 udpencap_print(const u_char *bp, u_int len, const u_char *bp2)
34 {
35 	u_int32_t *spi;
36 
37 	/* Recognize NAT-T Keepalive msgs. (draft-ietf-ipsec-udp-encaps-nn) */
38 	if (len == 1 && *bp == 0xFF) {
39 		printf("NAT-T Keepalive");
40 		return;
41 	}
42 
43 	if (len < sizeof(u_int32_t)) {
44 		printf("[|udpencap]");
45 		return;
46 	}
47 	printf("udpencap: ");
48 	spi = (u_int32_t *)(bp);
49 	if (*spi == 0)
50 		ike_print(bp + sizeof(u_int32_t), len - sizeof(u_int32_t));
51 	else
52 		esp_print(bp, len, bp2);
53 }
54