usr/src/ucblib/librpcsoc/get_myaddress.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 #pragma ident   "%Z%%M% %I%     %E% SMI"
  23
  24 /*
  25  * get_myaddress.c
  26  *
  27  * Get client's IP address via ioctl.  This avoids using the NIS.
  28  * Copyright (C) 1990, Sun Microsystems, Inc.
  29  */
  30
  31 #include <rpc/types.h>
  32 #include <rpc/pmap_prot.h>
  33 #include <sys/socket.h>
  34 #include <sys/sockio.h>
  35 #include <stdio.h>
  36 #include <net/if.h>
  37 #include <sys/ioctl.h>
  38 #include <arpa/inet.h>
  39 #include <netinet/in.h>
  40 #include <syslog.h>
  41 #include <malloc.h>
  42 #include <unistd.h>
  43 #include <stropts.h>
  44 #include <stdlib.h>
  45 #include <errno.h>
  46
  47 /*
  48  * don't use gethostbyname, which would invoke NIS
  49  */
  50 void
  51 get_myaddress(struct sockaddr_in *addr)
  52 {
  53         int s;
  54         struct ifconf ifc;
  55         struct ifreq ifreq, *ifr;
  56         int len, numifs;
  57         int ret;
  58
  59         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
  60             syslog(LOG_ERR, "get_myaddress: socket: %m");
  61             exit(1);
  62         }
  63
  64         do {
  65                 ret = ioctl(s, SIOCGIFNUM, (char *)&numifs);
  66         } while (ret < 0 && (errno == EINTR || errno == EAGAIN));
  67         if (ret < 0) {
  68                 syslog(LOG_ERR, "get_myaddress: ioctl: %m");
  69                 exit(1);
  70         }
  71
  72         ifc.ifc_len = numifs * sizeof (struct ifreq);
  73         if ((ifc.ifc_buf = (caddr_t)malloc(ifc.ifc_len)) == NULL) {
  74                 syslog(LOG_ERR, "get_myaddress: malloc: %m");
  75                 exit(1);
  76         }
  77
  78         do {
  79                 ret = ioctl(s, SIOCGIFCONF, (char *)&ifc);
  80         } while (ret < 0 && (errno == EINTR || errno == EAGAIN));
  81         if (ret < 0) {
  82                 syslog(LOG_ERR,
  83                     "get_myaddress: ioctl (get interface configuration): %m");
  84                 exit(1);
  85         }
  86
  87         /*
  88          * set default to loopback in case nothing is found.
  89          */
  90         addr->sin_family = AF_INET;
  91         addr->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  92         addr->sin_port = htons(PMAPPORT);
  93
  94         ifr = ifc.ifc_req;
  95         for (len = ifc.ifc_len; len > 0; len -= sizeof (ifreq), ifr++) {
  96                 ifreq = *ifr;
  97                 do {
  98                         ret = ioctl(s, SIOCGIFFLAGS, (char *)&ifreq);
  99                 } while (ret < 0 && (errno == EINTR || errno == EAGAIN));
 100                 if (ret < 0) {
 101                         syslog(LOG_ERR, "get_myaddress: ioctl: %m");
 102                         exit(1);
 103                 }
 104                 if (ifr->ifr_addr.sa_family != AF_INET)
 105                         continue;
 106                 if ((ifreq.ifr_flags & IFF_UP) == 0)
 107                         continue;
 108                 if (ifreq.ifr_flags & IFF_LOOPBACK)
 109                         continue;
 110                 if ((ifreq.ifr_flags & (IFF_MULTICAST | IFF_BROADCAST)) == 0)
 111                         continue;
 112                 *addr = *((struct sockaddr_in *)&ifr->ifr_addr);
 113                 addr->sin_port = htons(PMAPPORT);
 114                 break;
 115         }
 116         free(ifc.ifc_buf);
 117         (void) close(s);
 118 }