.ref-386BSD-0.1-patchkit/usr/src/lib/librpc/rpc/get_myaddress.c

/* @(#)get_myaddress.c  2.1 88/07/29 4.0 RPCSRC */
/*
 * 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(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)get_myaddress.c 1.4 87/08/11 Copyr 1984 Sun Micro";
#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/pmap_prot.h>
#include <sys/socket.h>
#include <stdio.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
 */
get_myaddress(addr)
        struct sockaddr_in *addr;
{
        int s;
        char buf[BUFSIZ];
        struct ifconf ifc;
        struct ifreq ifreq, *ifr;
        int len, slop;

        if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
            perror("get_myaddress: socket");
            exit(1);
        }
        ifc.ifc_len = sizeof (buf);
        ifc.ifc_buf = buf;
        if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) {
                perror("get_myaddress: ioctl (get interface configuration)");
                exit(1);
        }
        ifr = ifc.ifc_req;
        for (len = ifc.ifc_len; len; len -= sizeof ifreq) {
                ifreq = *ifr;
                if (ioctl(s, SIOCGIFFLAGS, (char *)&ifreq) < 0) {
                        perror("get_myaddress: ioctl");
                        exit(1);
                }
                if ((ifreq.ifr_flags & IFF_UP) &&
                    ifr->ifr_addr.sa_family == AF_INET) {
                        *addr = *((struct sockaddr_in *)&ifr->ifr_addr);
                        addr->sin_port = htons(PMAPPORT);
                        break;
                }
                /*
                 * Deal with variable length addresses
                 */
                slop = ifr->ifr_addr.sa_len - sizeof (struct sockaddr);
                if (slop) {
                        ifr = (struct ifreq *) ((caddr_t)ifr + slop);
                        len -= slop;
                }
                ifr++;
        }
        (void) close(s);
}