3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the Computer Systems
16 * Engineering Group at Lawrence Berkeley Laboratory.
17 * 4. Neither the name of the University nor of the Laboratory may be used
18 * to endorse or promote products derived from this software without
19 * specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 /* XXX Yes this is WAY too complicated */
39 static const char rcsid[] =
40 "@(#) $Id: findsaddr-socket.c,v 1.1 2000/11/23 20:17:12 leres Exp $ (LBL)";
43 #include <sys/param.h>
45 #include <sys/ioctl.h>
46 #include <sys/socket.h>
47 #ifdef HAVE_SYS_SOCKIO_H
48 #include <sys/sockio.h>
50 #include <sys/time.h> /* concession to AIX */
58 #include <net/if_dl.h>
59 #include <net/route.h>
60 #include <netinet/in.h>
69 #ifdef HAVE_OS_PROTO_H
73 #include "findsaddr.h"
75 #ifdef HAVE_SOCKADDR_SA_LEN
76 #define SALEN(sa) ((sa)->sa_len)
78 #define SALEN(sa) salen(sa)
82 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
86 struct rt_msghdr rtmsg;
90 static struct rtmsg rtmsg = {
91 { 0, RTM_VERSION, RTM_GET, 0,
92 RTF_UP | RTF_GATEWAY | RTF_HOST | RTF_STATIC,
93 RTA_DST | RTA_IFA, 0, 0, 0, 0, 0, { 0 } },
97 #ifndef HAVE_SOCKADDR_SA_LEN
98 static int salen(struct sockaddr *);
102 * Return the source address for the given destination address
105 findsaddr(register const struct sockaddr_in *to,
106 register struct sockaddr_in *from)
108 register struct rt_msghdr *rp;
111 register struct sockaddr_in *sp, *ifa;
112 register struct sockaddr *sa;
113 register int s, size, cc, seq, i;
115 static char errbuf[512];
117 s = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
119 sprintf(errbuf, "socket: %.128s", strerror(errno));
128 cp = (u_char *)(rp + 1);
130 sp = (struct sockaddr_in *)cp;
132 cp += roundup(SALEN((struct sockaddr *)sp), sizeof(u_int32_t));
134 size = cp - (u_char *)rp;
135 rp->rtm_msglen = size;
137 cc = write(s, (char *)rp, size);
139 sprintf(errbuf, "write: %.128s", strerror(errno));
144 sprintf(errbuf, "short write (%d != %d)", cc, size);
149 size = sizeof(rtmsg);
152 cc = read(s, (char *)rp, size);
154 sprintf(errbuf, "read: %.128s", strerror(errno));
159 } while (rp->rtm_seq != seq || rp->rtm_pid != pid);
163 if (rp->rtm_version != RTM_VERSION) {
164 sprintf(errbuf, "bad version %d", rp->rtm_version);
167 if (rp->rtm_msglen > cc) {
168 sprintf(errbuf, "bad msglen %d > %d", rp->rtm_msglen, cc);
171 if (rp->rtm_errno != 0) {
172 sprintf(errbuf, "rtm_errno: %.128s", strerror(rp->rtm_errno));
176 /* Find the interface sockaddr */
177 cp = (u_char *)(rp + 1);
178 for (i = 1; i != 0; i <<= 1)
179 if ((i & rp->rtm_addrs) != 0) {
180 sa = (struct sockaddr *)cp;
184 if (sa->sa_family == AF_INET) {
185 ifa = (struct sockaddr_in *)cp;
186 if (ifa->sin_addr.s_addr != 0) {
198 cp += roundup(SALEN(sa), sizeof(long));
204 #ifndef HAVE_SOCKADDR_SA_LEN
206 salen(struct sockaddr *sa)
208 switch (sa->sa_family) {
211 return (sizeof(struct sockaddr_in));
214 return (sizeof(struct sockaddr_dl));
217 return (sizeof(struct sockaddr));