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 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 } 100 101 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