1/* 2 * Copyright (c) 2008-2009 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29/* 30 * Copyright (c) 2000 31 * The Regents of the University of California. All rights reserved. 32 * 33 * Redistribution and use in source and binary forms, with or without 34 * modification, are permitted provided that the following conditions 35 * are met: 36 * 1. Redistributions of source code must retain the above copyright 37 * notice, this list of conditions and the following disclaimer. 38 * 2. Redistributions in binary form must reproduce the above copyright 39 * notice, this list of conditions and the following disclaimer in the 40 * documentation and/or other materials provided with the distribution. 41 * 3. All advertising materials mentioning features or use of this software 42 * must display the following acknowledgement: 43 * This product includes software developed by the Computer Systems 44 * Engineering Group at Lawrence Berkeley Laboratory. 45 * 4. Neither the name of the University nor of the Laboratory may be used 46 * to endorse or promote products derived from this software without 47 * specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * $FreeBSD: src/contrib/traceroute/findsaddr-socket.c,v 1.2 2002/07/30 04:49:13 fenner Exp $ 62 */ 63 64/* XXX Yes this is WAY too complicated */ 65 66#include <sys/param.h> 67#include <sys/file.h> 68#include <sys/ioctl.h> 69#include <sys/socket.h> 70#ifdef HAVE_SYS_SOCKIO_H 71#include <sys/sockio.h> 72#endif 73#include <sys/time.h> /* concession to AIX */ 74 75#if __STDC__ 76struct mbuf; 77struct rtentry; 78#endif 79 80#include <net/if.h> 81#include <net/if_dl.h> 82#include <net/route.h> 83#include <netinet/in.h> 84 85#include <errno.h> 86#include <stdio.h> 87#include <stdlib.h> 88#include <string.h> 89#include <unistd.h> 90 91#include "gnuc.h" 92#ifdef HAVE_OS_PROTO_H 93#include "os-proto.h" 94#endif 95 96#include "findsaddr.h" 97 98#ifdef HAVE_SOCKADDR_SA_LEN 99#define SALEN(sa) ((sa)->sa_len) 100#else 101#define SALEN(sa) salen(sa) 102#endif 103 104#ifndef roundup 105#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 106#endif 107 108struct rtmsg { 109 struct rt_msghdr rtmsg; 110 u_char data[512]; 111}; 112 113static struct rtmsg rtmsg = { 114 { 0, RTM_VERSION, RTM_GET, 0, 115 RTF_UP | RTF_GATEWAY | RTF_HOST | RTF_STATIC, 116 RTA_DST | RTA_IFA, 0, 0, 0, 0, 0, { 0 } }, 117 { 0 } 118}; 119 120#ifndef HAVE_SOCKADDR_SA_LEN 121static int salen(struct sockaddr *); 122#endif 123 124/* 125 * Return the source address for the given destination address 126 */ 127const char * 128findsaddr(register const struct sockaddr_in *to, 129 register struct sockaddr_in *from) 130{ 131 register struct rt_msghdr *rp; 132 register u_char *cp; 133 134 register struct sockaddr_in *sp, *ifa; 135 register struct sockaddr *sa; 136 register int s, size, cc, seq, i; 137 register pid_t pid; 138 static char errbuf[512]; 139 140 s = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC); 141 if (s < 0) { 142 snprintf(errbuf, sizeof(errbuf), "socket: %.128s", strerror(errno)); 143 return (errbuf); 144 } 145 146 seq = 0; 147 pid = getpid(); 148 149 rp = &rtmsg.rtmsg; 150 rp->rtm_seq = ++seq; 151 cp = (u_char *)(rp + 1); 152 153 sp = (struct sockaddr_in *)cp; 154 *sp = *to; 155 cp += roundup(SALEN((struct sockaddr *)sp), sizeof(u_int32_t)); 156 157 size = cp - (u_char *)rp; 158 rp->rtm_msglen = size; 159 160 cc = write(s, (char *)rp, size); 161 if (cc < 0) { 162 snprintf(errbuf, sizeof(errbuf), "write: %.128s", strerror(errno)); 163 close(s); 164 return (errbuf); 165 } 166 if (cc != size) { 167 snprintf(errbuf, sizeof(errbuf), "short write (%d != %d)", cc, size); 168 close(s); 169 return (errbuf); 170 } 171 172 size = sizeof(rtmsg); 173 do { 174 memset(rp, 0, size); 175 cc = read(s, (char *)rp, size); 176 if (cc < 0) { 177 snprintf(errbuf, sizeof(errbuf), "read: %.128s", strerror(errno)); 178 close(s); 179 return (errbuf); 180 } 181 182 } while (rp->rtm_seq != seq || rp->rtm_pid != pid); 183 close(s); 184 185 186 if (rp->rtm_version != RTM_VERSION) { 187 snprintf(errbuf, sizeof(errbuf), "bad version %d", rp->rtm_version); 188 return (errbuf); 189 } 190 if (rp->rtm_msglen > cc) { 191 snprintf(errbuf, sizeof(errbuf), "bad msglen %d > %d", rp->rtm_msglen, cc); 192 return (errbuf); 193 } 194 if (rp->rtm_errno != 0) { 195 snprintf(errbuf, sizeof(errbuf), "rtm_errno: %.128s", strerror(rp->rtm_errno)); 196 return (errbuf); 197 } 198 199 /* Find the interface sockaddr */ 200 cp = (u_char *)(rp + 1); 201 for (i = 1; i != 0; i <<= 1) 202 if ((i & rp->rtm_addrs) != 0) { 203 sa = (struct sockaddr *)cp; 204 switch (i) { 205 206 case RTA_IFA: 207 if (sa->sa_family == AF_INET) { 208 ifa = (struct sockaddr_in *)cp; 209 if (ifa->sin_addr.s_addr != 0) { 210 *from = *ifa; 211 return (NULL); 212 } 213 } 214 break; 215 216 default: 217 break; 218 /* empty */ 219 } 220 221 if (SALEN(sa) == 0) 222 cp += sizeof (u_int32_t); 223 else 224 cp += roundup(SALEN(sa), sizeof (u_int32_t)); 225 } 226 227 return ("failed!"); 228} 229 230#ifndef HAVE_SOCKADDR_SA_LEN 231static int 232salen(struct sockaddr *sa) 233{ 234 switch (sa->sa_family) { 235 236 case AF_INET: 237 return (sizeof(struct sockaddr_in)); 238 239 case AF_LINK: 240 return (sizeof(struct sockaddr_dl)); 241 242 default: 243 return (sizeof(struct sockaddr)); 244 } 245} 246#endif 247