ifaddrlist.c revision 1.3
1 /* $NetBSD: ifaddrlist.c,v 1.3 1999/02/24 21:21:24 explorer Exp $ */ 2 3 /* 4 * Copyright (c) 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the Computer Systems 18 * Engineering Group at Lawrence Berkeley Laboratory. 19 * 4. Neither the name of the University nor of the Laboratory may be used 20 * to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 #if 0 39 static const char rcsid[] = 40 "@(#) Header: ifaddrlist.c,v 1.2 97/04/22 13:31:05 leres Exp (LBL)"; 41 #else 42 __RCSID("$NetBSD: ifaddrlist.c,v 1.3 1999/02/24 21:21:24 explorer Exp $"); 43 #endif 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/file.h> 48 #include <sys/ioctl.h> 49 #include <sys/socket.h> 50 #ifdef HAVE_SYS_SOCKIO_H 51 #include <sys/sockio.h> 52 #endif 53 #include <sys/time.h> /* concession to AIX */ 54 55 #if __STDC__ 56 struct mbuf; 57 struct rtentry; 58 #endif 59 60 #include <net/if.h> 61 #include <netinet/in.h> 62 #include <arpa/inet.h> 63 64 #include <ctype.h> 65 #include <errno.h> 66 #include <memory.h> 67 #include <stdio.h> 68 #include <stdlib.h> 69 #include <string.h> 70 #include <unistd.h> 71 72 #include "gnuc.h" 73 #ifdef HAVE_OS_PROTO_H 74 #include "os-proto.h" 75 #endif 76 77 #include "ifaddrlist.h" 78 #include "savestr.h" 79 80 81 /* Not all systems have IFF_LOOPBACK */ 82 #ifdef IFF_LOOPBACK 83 #define ISLOOPBACK(p) ((p)->ifr_flags & IFF_LOOPBACK) 84 #else 85 #define ISLOOPBACK(p) (strcmp((p)->ifr_name, "lo0") == 0) 86 #endif 87 88 #define MAX_IPADDR 256 89 90 /* 91 * Return the interface list 92 */ 93 int 94 ifaddrlist(struct ifaddrlist **ipaddrp, char *errbuf, int buflen) 95 { 96 int fd, nipaddr; 97 #ifdef HAVE_SOCKADDR_SA_LEN 98 int n; 99 #endif 100 struct ifreq *ifrp, *ifend, *ifnext, *mp; 101 struct sockaddr_in *sin; 102 struct ifaddrlist *al; 103 struct ifconf ifc; 104 struct ifreq ibuf[MAX_IPADDR], ifr; 105 char device[sizeof(ifr.ifr_name) + 1]; 106 static struct ifaddrlist ifaddrlist[MAX_IPADDR]; 107 108 fd = socket(AF_INET, SOCK_DGRAM, 0); 109 if (fd < 0) { 110 (void)snprintf(errbuf, buflen, "socket: %s", strerror(errno)); 111 return (-1); 112 } 113 ifc.ifc_len = sizeof(ibuf); 114 ifc.ifc_buf = (caddr_t)ibuf; 115 116 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 || 117 ifc.ifc_len < sizeof(struct ifreq)) { 118 (void)snprintf(errbuf, buflen, "SIOCGIFCONF: %s", strerror(errno)); 119 (void)close(fd); 120 return (-1); 121 } 122 ifrp = ibuf; 123 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len); 124 125 al = ifaddrlist; 126 mp = NULL; 127 nipaddr = 0; 128 for (; ifrp < ifend; ifrp = ifnext) { 129 #ifdef HAVE_SOCKADDR_SA_LEN 130 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name); 131 if (n < sizeof(*ifrp)) 132 ifnext = ifrp + 1; 133 else 134 ifnext = (struct ifreq *)((char *)ifrp + n); 135 if (ifrp->ifr_addr.sa_family != AF_INET) 136 continue; 137 #else 138 ifnext = ifrp + 1; 139 #endif 140 /* 141 * Need a template to preserve address info that is 142 * used below to locate the next entry. (Otherwise, 143 * SIOCGIFFLAGS stomps over it because the requests 144 * are returned in a union.) 145 */ 146 strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name)); 147 if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { 148 if (errno == ENXIO) 149 continue; 150 (void)snprintf(errbuf, buflen, "SIOCGIFFLAGS: %.*s: %s", 151 (int)sizeof(ifr.ifr_name), ifr.ifr_name, 152 strerror(errno)); 153 (void)close(fd); 154 return (-1); 155 } 156 157 /* Must be up */ 158 if ((ifr.ifr_flags & IFF_UP) == 0) 159 continue; 160 161 /* 162 * Must not be a loopback address (127/8) 163 */ 164 sin = (struct sockaddr_in *)&ifrp->ifr_addr; 165 if (ISLOOPBACK(&ifr)) 166 if (ntohl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 167 continue; 168 169 (void)strncpy(device, ifrp->ifr_name, sizeof(ifrp->ifr_name)); 170 device[sizeof(device) - 1] = '\0'; 171 172 al->addr = sin->sin_addr.s_addr; 173 al->device = savestr(device); 174 ++al; 175 ++nipaddr; 176 } 177 (void)close(fd); 178 179 *ipaddrp = ifaddrlist; 180 return (nipaddr); 181 } 182
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