1 /* $OpenBSD: get_myaddress.c,v 1.16 2020/12/30 18:56:35 benno Exp $ */ 2 3 /* 4 * Copyright (c) 2010, Oracle America, Inc. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: 9 * 10 * * Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * * Redistributions in binary form must reproduce the above 13 * copyright notice, this list of conditions and the following 14 * disclaimer in the documentation and/or other materials 15 * provided with the distribution. 16 * * Neither the name of the "Oracle America, Inc." nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * get_myaddress.c 36 * 37 * Get client's IP address via ioctl. This avoids using the yellowpages. 38 */ 39 40 #include <rpc/types.h> 41 #include <rpc/xdr.h> 42 #include <rpc/pmap_prot.h> 43 #include <rpc/rpc.h> 44 #include <sys/socket.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <unistd.h> 48 #include <net/if.h> 49 #include <netinet/in.h> 50 #include <ifaddrs.h> 51 52 /* 53 * don't use gethostbyname, which would invoke yellow pages 54 * 55 * Avoid loopback interfaces. We return information from a loopback 56 * interface only if there are no other possible interfaces. 57 */ 58 int 59 get_myaddress(struct sockaddr_in *addr) 60 { 61 struct ifaddrs *ifap, *ifa; 62 int loopback = 0, gotit = 0; 63 64 if (getifaddrs(&ifap) != 0) 65 return (-1); 66 67 again: 68 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 69 if ((ifa->ifa_flags & IFF_UP) && 70 ifa->ifa_addr != NULL && 71 ifa->ifa_addr->sa_family == AF_INET && 72 (loopback == 1 && (ifa->ifa_flags & IFF_LOOPBACK))) { 73 *addr = *((struct sockaddr_in *)ifa->ifa_addr); 74 addr->sin_port = htons(PMAPPORT); 75 gotit = 1; 76 break; 77 } 78 } 79 if (gotit == 0 && loopback == 0) { 80 loopback = 1; 81 goto again; 82 } 83 freeifaddrs(ifap); 84 return (0); 85 } 86 DEF_WEAK(get_myaddress); 87