1 /* $OpenBSD: print-mobile.c,v 1.7 2022/01/05 05:46:18 dlg Exp $ */
2 /* $NetBSD: print-mobile.c,v 1.3 1999/07/26 06:11:57 itojun Exp $ */
3
4 /*
5 * (c) 1998 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/time.h>
34 #include <sys/uio.h>
35 #include <sys/socket.h>
36
37 #include <netinet/in.h>
38 #include <netinet/ip.h>
39
40 #include <netdb.h>
41 #include <stdio.h>
42
43 #include "interface.h"
44 #include "addrtoname.h"
45 #include "extract.h" /* must come after interface.h */
46
47 #define MOBILE_SIZE (8)
48
49 struct mobile_ip {
50 u_int16_t proto;
51 u_int16_t hcheck;
52 u_int32_t odst;
53 u_int32_t osrc;
54 };
55
56 #define OSRC_PRES 0x0080 /* old source is present */
57
58 static u_int16_t mob_in_cksum(u_short *p, int len);
59
60 /*
61 * Deencapsulate and print a mobile-tunneled IP datagram
62 */
63 void
mobile_print(const u_char * bp,u_int length)64 mobile_print(const u_char *bp, u_int length)
65 {
66 const struct mobile_ip *mob;
67 u_short proto,crc;
68 u_char osp =0; /* old source address present */
69
70 mob = (const struct mobile_ip *)bp;
71
72 if (length < MOBILE_SIZE) {
73 printf("[|mobile]");
74 return;
75 }
76
77 proto = EXTRACT_16BITS(&mob->proto);
78 crc = EXTRACT_16BITS(&mob->hcheck);
79 if (proto & OSRC_PRES) {
80 osp=1;
81 }
82
83 if (osp) {
84 printf("[S] ");
85 if (vflag)
86 printf("%s ",ipaddr_string(&mob->osrc));
87 } else {
88 printf("[] ");
89 }
90 if (vflag) {
91 printf("> %s ",ipaddr_string(&mob->odst));
92 printf("(oproto=%d)",proto>>8);
93 }
94 if (mob_in_cksum((u_short *)mob, osp ? 12 : 8)!=0) {
95 printf(" (bad checksum %d)",crc);
96 }
97
98 return;
99 }
100
mob_in_cksum(u_short * p,int len)101 static u_int16_t mob_in_cksum(u_short *p, int len)
102 {
103 u_int32_t sum = 0;
104 int nwords = len >> 1;
105
106 while (nwords-- != 0)
107 sum += *p++;
108
109 if (len & 1) {
110 union {
111 u_int16_t w;
112 u_int32_t c[2];
113 } u;
114 u.c[0] = *(u_char *)p;
115 u.c[1] = 0;
116 sum += u.w;
117 }
118
119 /* end-around-carry */
120 sum = (sum >> 16) + (sum & 0xffff);
121 sum += (sum >> 16);
122 return (~sum);
123 }
124
125