freebsd-nq/lib/libc/rpc/get_myaddress.c
Bill Paul 0e710e8f95 Make selection logic more strict. Only select AF_INET loopback interfaces
that are up on second (loopback only) pass, and only select non-loopback
AF_INET interfaces that are up on first pass.
1997-09-21 23:04:51 +00:00

113 lines
3.2 KiB
C

/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)get_myaddress.c 1.4 87/08/11 Copyr 1984 Sun Micro";*/
/*static char *sccsid = "from: @(#)get_myaddress.c 2.1 88/07/29 4.0 RPCSRC";*/
static char *rcsid = "$Id: get_myaddress.c,v 1.12 1997/06/20 17:54:11 wpaul Exp $";
#endif
/*
* get_myaddress.c
*
* Get client's IP address via ioctl. This avoids using the yellowpages.
* Copyright (C) 1984, Sun Microsystems, Inc.
*/
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/pmap_prot.h>
#include <sys/socket.h>
#include <stdio.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
/*
* don't use gethostbyname, which would invoke yellow pages
*
* Avoid loopback interfaces. We return information from a loopback
* interface only if there are no other possible interfaces.
*/
int
get_myaddress(addr)
struct sockaddr_in *addr;
{
int s;
char buf[BUFSIZ];
struct ifconf ifc;
struct ifreq ifreq, *ifr, *end;
int loopback = 0, gotit = 0;
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
return(-1);
}
ifc.ifc_len = sizeof (buf);
ifc.ifc_buf = buf;
if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) {
close(s);
return(-1);
}
again:
ifr = ifc.ifc_req;
end = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
while (ifr < end) {
ifreq = *ifr;
if (ioctl(s, SIOCGIFFLAGS, (char *)&ifreq) < 0) {
close(s);
return(-1);
}
if (((ifreq.ifr_flags & IFF_UP) &&
ifr->ifr_addr.sa_family == AF_INET &&
!(ifreq.ifr_flags & IFF_LOOPBACK)) ||
(loopback == 1 && (ifreq.ifr_flags & IFF_LOOPBACK)
&& (ifr->ifr_addr.sa_family == AF_INET)
&& (ifr->ifr_flags & IFF_UP))) {
*addr = *((struct sockaddr_in *)&ifr->ifr_addr);
addr->sin_port = htons(PMAPPORT);
gotit = 1;
break;
}
if (ifr->ifr_addr.sa_len)
ifr = (struct ifreq *) ((caddr_t) ifr +
ifr->ifr_addr.sa_len -
sizeof(struct sockaddr));
ifr++;
}
if (gotit == 0 && loopback == 0) {
loopback = 1;
goto again;
}
(void) close(s);
return (0);
}