1100784Sfenner/* 2100784Sfenner * Copyright (c) 2000 3100784Sfenner * The Regents of the University of California. All rights reserved. 4100784Sfenner * 5100784Sfenner * Redistribution and use in source and binary forms, with or without 6100784Sfenner * modification, are permitted provided that the following conditions 7100784Sfenner * are met: 8100784Sfenner * 1. Redistributions of source code must retain the above copyright 9100784Sfenner * notice, this list of conditions and the following disclaimer. 10100784Sfenner * 2. Redistributions in binary form must reproduce the above copyright 11100784Sfenner * notice, this list of conditions and the following disclaimer in the 12100784Sfenner * documentation and/or other materials provided with the distribution. 13100784Sfenner * 3. All advertising materials mentioning features or use of this software 14100784Sfenner * must display the following acknowledgement: 15100784Sfenner * This product includes software developed by the Computer Systems 16100784Sfenner * Engineering Group at Lawrence Berkeley Laboratory. 17100784Sfenner * 4. Neither the name of the University nor of the Laboratory may be used 18100784Sfenner * to endorse or promote products derived from this software without 19100784Sfenner * specific prior written permission. 20100784Sfenner * 21100784Sfenner * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22100784Sfenner * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23100784Sfenner * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24100784Sfenner * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25100784Sfenner * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26100784Sfenner * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27100784Sfenner * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28100784Sfenner * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29100784Sfenner * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30100784Sfenner * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31100784Sfenner * SUCH DAMAGE. 32100905Sfenner * 33100905Sfenner * $FreeBSD$ 34100784Sfenner */ 35100784Sfenner 36100784Sfenner/* XXX Yes this is WAY too complicated */ 37100784Sfenner 38100784Sfenner#ifndef lint 39100784Sfennerstatic const char rcsid[] = 40100784Sfenner "@(#) $Id: findsaddr-socket.c,v 1.1 2000/11/23 20:17:12 leres Exp $ (LBL)"; 41100784Sfenner#endif 42100784Sfenner 43100784Sfenner#include <sys/param.h> 44100784Sfenner#include <sys/file.h> 45100784Sfenner#include <sys/ioctl.h> 46100784Sfenner#include <sys/socket.h> 47100784Sfenner#ifdef HAVE_SYS_SOCKIO_H 48100784Sfenner#include <sys/sockio.h> 49100784Sfenner#endif 50100784Sfenner#include <sys/time.h> /* concession to AIX */ 51100784Sfenner 52100784Sfenner#if __STDC__ 53100784Sfennerstruct mbuf; 54100784Sfennerstruct rtentry; 55100784Sfenner#endif 56100784Sfenner 57100784Sfenner#include <net/if.h> 58100784Sfenner#include <net/if_dl.h> 59100784Sfenner#include <net/route.h> 60100784Sfenner#include <netinet/in.h> 61100784Sfenner 62100784Sfenner#include <errno.h> 63100784Sfenner#include <stdio.h> 64100784Sfenner#include <stdlib.h> 65100784Sfenner#include <string.h> 66100784Sfenner#include <unistd.h> 67100784Sfenner 68100784Sfenner#include "gnuc.h" 69100784Sfenner#ifdef HAVE_OS_PROTO_H 70100784Sfenner#include "os-proto.h" 71100784Sfenner#endif 72100784Sfenner 73100784Sfenner#include "findsaddr.h" 74100784Sfenner 75100784Sfenner#ifdef HAVE_SOCKADDR_SA_LEN 76100784Sfenner#define SALEN(sa) ((sa)->sa_len) 77100784Sfenner#else 78100784Sfenner#define SALEN(sa) salen(sa) 79100784Sfenner#endif 80100784Sfenner 81100784Sfenner#ifndef roundup 82100784Sfenner#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ 83100784Sfenner#endif 84100784Sfenner 85100784Sfennerstruct rtmsg { 86100784Sfenner struct rt_msghdr rtmsg; 87100784Sfenner u_char data[512]; 88100784Sfenner}; 89100784Sfenner 90100784Sfennerstatic struct rtmsg rtmsg = { 91100784Sfenner { 0, RTM_VERSION, RTM_GET, 0, 92100784Sfenner RTF_UP | RTF_GATEWAY | RTF_HOST | RTF_STATIC, 93100784Sfenner RTA_DST | RTA_IFA, 0, 0, 0, 0, 0, { 0 } }, 94100784Sfenner { 0 } 95100784Sfenner}; 96100784Sfenner 97100784Sfenner#ifndef HAVE_SOCKADDR_SA_LEN 98100784Sfennerstatic int salen(struct sockaddr *); 99100784Sfenner#endif 100100784Sfenner 101100784Sfenner/* 102100784Sfenner * Return the source address for the given destination address 103100784Sfenner */ 104100784Sfennerconst char * 105100784Sfennerfindsaddr(register const struct sockaddr_in *to, 106100784Sfenner register struct sockaddr_in *from) 107100784Sfenner{ 108100784Sfenner register struct rt_msghdr *rp; 109100784Sfenner register u_char *cp; 110100784Sfenner 111100784Sfenner register struct sockaddr_in *sp, *ifa; 112100784Sfenner register struct sockaddr *sa; 113100784Sfenner register int s, size, cc, seq, i; 114100784Sfenner register pid_t pid; 115100784Sfenner static char errbuf[512]; 116100784Sfenner 117100784Sfenner s = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC); 118100784Sfenner if (s < 0) { 119100784Sfenner sprintf(errbuf, "socket: %.128s", strerror(errno)); 120100784Sfenner return (errbuf); 121100784Sfenner } 122100784Sfenner 123100784Sfenner seq = 0; 124100784Sfenner pid = getpid(); 125100784Sfenner 126100784Sfenner rp = &rtmsg.rtmsg; 127100784Sfenner rp->rtm_seq = ++seq; 128100784Sfenner cp = (u_char *)(rp + 1); 129100784Sfenner 130100784Sfenner sp = (struct sockaddr_in *)cp; 131100784Sfenner *sp = *to; 132100784Sfenner cp += roundup(SALEN((struct sockaddr *)sp), sizeof(u_int32_t)); 133100784Sfenner 134100784Sfenner size = cp - (u_char *)rp; 135100784Sfenner rp->rtm_msglen = size; 136100784Sfenner 137100784Sfenner cc = write(s, (char *)rp, size); 138100784Sfenner if (cc < 0) { 139100784Sfenner sprintf(errbuf, "write: %.128s", strerror(errno)); 140100784Sfenner close(s); 141100784Sfenner return (errbuf); 142100784Sfenner } 143100784Sfenner if (cc != size) { 144100784Sfenner sprintf(errbuf, "short write (%d != %d)", cc, size); 145100784Sfenner close(s); 146100784Sfenner return (errbuf); 147100784Sfenner } 148100784Sfenner 149100784Sfenner size = sizeof(rtmsg); 150100784Sfenner do { 151100784Sfenner memset(rp, 0, size); 152100784Sfenner cc = read(s, (char *)rp, size); 153100784Sfenner if (cc < 0) { 154100784Sfenner sprintf(errbuf, "read: %.128s", strerror(errno)); 155100784Sfenner close(s); 156100784Sfenner return (errbuf); 157100784Sfenner } 158100784Sfenner 159100784Sfenner } while (rp->rtm_seq != seq || rp->rtm_pid != pid); 160100784Sfenner close(s); 161100784Sfenner 162100784Sfenner 163100784Sfenner if (rp->rtm_version != RTM_VERSION) { 164100784Sfenner sprintf(errbuf, "bad version %d", rp->rtm_version); 165100784Sfenner return (errbuf); 166100784Sfenner } 167100784Sfenner if (rp->rtm_msglen > cc) { 168100784Sfenner sprintf(errbuf, "bad msglen %d > %d", rp->rtm_msglen, cc); 169100784Sfenner return (errbuf); 170100784Sfenner } 171100784Sfenner if (rp->rtm_errno != 0) { 172100784Sfenner sprintf(errbuf, "rtm_errno: %.128s", strerror(rp->rtm_errno)); 173100784Sfenner return (errbuf); 174100784Sfenner } 175100784Sfenner 176100784Sfenner /* Find the interface sockaddr */ 177100784Sfenner cp = (u_char *)(rp + 1); 178100784Sfenner for (i = 1; i != 0; i <<= 1) 179100784Sfenner if ((i & rp->rtm_addrs) != 0) { 180100784Sfenner sa = (struct sockaddr *)cp; 181100784Sfenner switch (i) { 182100784Sfenner 183100784Sfenner case RTA_IFA: 184100784Sfenner if (sa->sa_family == AF_INET) { 185100784Sfenner ifa = (struct sockaddr_in *)cp; 186100784Sfenner if (ifa->sin_addr.s_addr != 0) { 187100784Sfenner *from = *ifa; 188100784Sfenner return (NULL); 189100784Sfenner } 190100784Sfenner } 191100784Sfenner break; 192100784Sfenner 193100784Sfenner } 194100784Sfenner 195100784Sfenner if (SALEN(sa) == 0) 196100905Sfenner cp += sizeof(long); 197100784Sfenner else 198100905Sfenner cp += roundup(SALEN(sa), sizeof(long)); 199100784Sfenner } 200100784Sfenner 201100784Sfenner return ("failed!"); 202100784Sfenner} 203100784Sfenner 204100784Sfenner#ifndef HAVE_SOCKADDR_SA_LEN 205100784Sfennerstatic int 206100784Sfennersalen(struct sockaddr *sa) 207100784Sfenner{ 208100784Sfenner switch (sa->sa_family) { 209100784Sfenner 210100784Sfenner case AF_INET: 211100784Sfenner return (sizeof(struct sockaddr_in)); 212100784Sfenner 213100784Sfenner case AF_LINK: 214100784Sfenner return (sizeof(struct sockaddr_dl)); 215100784Sfenner 216100784Sfenner default: 217100784Sfenner return (sizeof(struct sockaddr)); 218100784Sfenner } 219100784Sfenner} 220100784Sfenner#endif 221