xref: /freebsd/contrib/tcpdump/print-mobile.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*	$NetBSD: print-mobile.c,v 1.2 1998/09/30 08:57:01 hwr Exp $ */
2 
3 /*
4  * (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Heiko W.Rupp <hwr@pilhuhn.de>
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /* \summary: IPv4 mobility printer */
40 
41 #include <config.h>
42 
43 #include "netdissect-stdinc.h"
44 
45 #include "netdissect.h"
46 #include "addrtoname.h"
47 #include "extract.h"
48 
49 #define MOBILE_SIZE (8)
50 
51 struct mobile_ip {
52 	nd_uint16_t proto;
53 	nd_uint16_t hcheck;
54 	nd_uint32_t odst;
55 	nd_uint32_t osrc;
56 };
57 
58 #define OSRC_PRES	0x0080	/* old source is present */
59 
60 /*
61  * Deencapsulate and print a mobile-tunneled IP datagram
62  */
63 void
64 mobile_print(netdissect_options *ndo, const u_char *bp, u_int length)
65 {
66 	const struct mobile_ip *mob;
67 	struct cksum_vec vec[1];
68 	u_short proto,crc;
69 	u_char osp =0;			/* old source address present */
70 
71 	ndo->ndo_protocol = "mobile";
72 	mob = (const struct mobile_ip *)bp;
73 
74 	if (length < MOBILE_SIZE || !ND_TTEST_SIZE(mob)) {
75 		nd_print_trunc(ndo);
76 		return;
77 	}
78 	ND_PRINT("mobile: ");
79 
80 	proto = GET_BE_U_2(mob->proto);
81 	crc =  GET_BE_U_2(mob->hcheck);
82 	if (proto & OSRC_PRES) {
83 		osp=1;
84 	}
85 
86 	if (osp)  {
87 		ND_PRINT("[S] ");
88 		if (ndo->ndo_vflag)
89 			ND_PRINT("%s ", GET_IPADDR_STRING(mob->osrc));
90 	} else {
91 		ND_PRINT("[] ");
92 	}
93 	if (ndo->ndo_vflag) {
94 		ND_PRINT("> %s ", GET_IPADDR_STRING(mob->odst));
95 		ND_PRINT("(oproto=%u)", proto>>8);
96 	}
97 	vec[0].ptr = (const uint8_t *)(const void *)mob;
98 	vec[0].len = osp ? 12 : 8;
99 	if (in_cksum(vec, 1)!=0) {
100 		ND_PRINT(" (bad checksum %u)", crc);
101 	}
102 }
103