1 /* $NetBSD: fad-getad.c,v 1.1.1.3 2013/04/06 15:57:49 christos Exp $ */ 2 3 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */ 4 /* 5 * Copyright (c) 1994, 1995, 1996, 1997, 1998 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the Computer Systems 19 * Engineering Group at Lawrence Berkeley Laboratory. 20 * 4. Neither the name of the University nor of the Laboratory may be used 21 * to endorse or promote products derived from this software without 22 * specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static const char rcsid[] _U_ = 39 "@(#) Header: /tcpdump/master/libpcap/fad-getad.c,v 1.12 2007-09-14 00:44:55 guy Exp (LBL)"; 40 #endif 41 42 #ifdef HAVE_CONFIG_H 43 #include "config.h" 44 #endif 45 46 #include <sys/types.h> 47 #include <sys/socket.h> 48 #include <netinet/in.h> 49 50 #include <net/if.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <ifaddrs.h> 58 59 #include "pcap-int.h" 60 61 #ifdef HAVE_OS_PROTO_H 62 #include "os-proto.h" 63 #endif 64 65 #ifdef AF_PACKET 66 # ifdef HAVE_NETPACKET_PACKET_H 67 /* Solaris 11 and later, Linux distributions with newer glibc */ 68 # include <netpacket/packet.h> 69 # else /* HAVE_NETPACKET_PACKET_H */ 70 /* LynxOS, Linux distributions with older glibc */ 71 # ifdef __Lynx__ 72 /* LynxOS */ 73 # include <netpacket/if_packet.h> 74 # else /* __Lynx__ */ 75 /* Linux */ 76 # include <linux/types.h> 77 # include <linux/if_packet.h> 78 # endif /* __Lynx__ */ 79 # endif /* HAVE_NETPACKET_PACKET_H */ 80 #endif /* AF_PACKET */ 81 82 /* 83 * This is fun. 84 * 85 * In older BSD systems, socket addresses were fixed-length, and 86 * "sizeof (struct sockaddr)" gave the size of the structure. 87 * All addresses fit within a "struct sockaddr". 88 * 89 * In newer BSD systems, the socket address is variable-length, and 90 * there's an "sa_len" field giving the length of the structure; 91 * this allows socket addresses to be longer than 2 bytes of family 92 * and 14 bytes of data. 93 * 94 * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553 95 * variant of the old BSD scheme (with "struct sockaddr_storage" rather 96 * than "struct sockaddr"), and some use the new BSD scheme. 97 * 98 * Some versions of GNU libc use neither scheme, but has an "SA_LEN()" 99 * macro that determines the size based on the address family. Other 100 * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553 101 * but not in the final version). On the latter systems, we explicitly 102 * check the AF_ type to determine the length; we assume that on 103 * all those systems we have "struct sockaddr_storage". 104 */ 105 #ifndef SA_LEN 106 #ifdef HAVE_SOCKADDR_SA_LEN 107 #define SA_LEN(addr) ((addr)->sa_len) 108 #else /* HAVE_SOCKADDR_SA_LEN */ 109 #ifdef HAVE_SOCKADDR_STORAGE 110 static size_t 111 get_sa_len(struct sockaddr *addr) 112 { 113 switch (addr->sa_family) { 114 115 #ifdef AF_INET 116 case AF_INET: 117 return (sizeof (struct sockaddr_in)); 118 #endif 119 120 #ifdef AF_INET6 121 case AF_INET6: 122 return (sizeof (struct sockaddr_in6)); 123 #endif 124 125 #ifdef AF_PACKET 126 case AF_PACKET: 127 return (sizeof (struct sockaddr_ll)); 128 #endif 129 130 default: 131 return (sizeof (struct sockaddr)); 132 } 133 } 134 #define SA_LEN(addr) (get_sa_len(addr)) 135 #else /* HAVE_SOCKADDR_STORAGE */ 136 #define SA_LEN(addr) (sizeof (struct sockaddr)) 137 #endif /* HAVE_SOCKADDR_STORAGE */ 138 #endif /* HAVE_SOCKADDR_SA_LEN */ 139 #endif /* SA_LEN */ 140 141 /* 142 * Get a list of all interfaces that are up and that we can open. 143 * Returns -1 on error, 0 otherwise. 144 * The list, as returned through "alldevsp", may be null if no interfaces 145 * were up and could be opened. 146 * 147 * This is the implementation used on platforms that have "getifaddrs()". 148 */ 149 int 150 pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf) 151 { 152 pcap_if_t *devlist = NULL; 153 struct ifaddrs *ifap, *ifa; 154 struct sockaddr *addr, *netmask, *broadaddr, *dstaddr; 155 size_t addr_size, broadaddr_size, dstaddr_size; 156 int ret = 0; 157 char *p, *q; 158 159 /* 160 * Get the list of interface addresses. 161 * 162 * Note: this won't return information about interfaces 163 * with no addresses; are there any such interfaces 164 * that would be capable of receiving packets? 165 * (Interfaces incapable of receiving packets aren't 166 * very interesting from libpcap's point of view.) 167 * 168 * LAN interfaces will probably have link-layer 169 * addresses; I don't know whether all implementations 170 * of "getifaddrs()" now, or in the future, will return 171 * those. 172 */ 173 if (getifaddrs(&ifap) != 0) { 174 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 175 "getifaddrs: %s", pcap_strerror(errno)); 176 return (-1); 177 } 178 for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) { 179 /* 180 * Is this interface up? 181 */ 182 if (!(ifa->ifa_flags & IFF_UP)) { 183 /* 184 * No, so don't add it to the list. 185 */ 186 continue; 187 } 188 189 /* 190 * "ifa_addr" was apparently null on at least one 191 * interface on some system. 192 * 193 * "ifa_broadaddr" may be non-null even on 194 * non-broadcast interfaces, and was null on 195 * at least one OpenBSD 3.4 system on at least 196 * one interface with IFF_BROADCAST set. 197 * 198 * "ifa_dstaddr" was, on at least one FreeBSD 4.1 199 * system, non-null on a non-point-to-point 200 * interface. 201 * 202 * Therefore, we supply the address and netmask only 203 * if "ifa_addr" is non-null (if there's no address, 204 * there's obviously no netmask), and supply the 205 * broadcast and destination addresses if the appropriate 206 * flag is set *and* the appropriate "ifa_" entry doesn't 207 * evaluate to a null pointer. 208 */ 209 if (ifa->ifa_addr != NULL) { 210 addr = ifa->ifa_addr; 211 addr_size = SA_LEN(addr); 212 netmask = ifa->ifa_netmask; 213 } else { 214 addr = NULL; 215 addr_size = 0; 216 netmask = NULL; 217 } 218 if (ifa->ifa_flags & IFF_BROADCAST && 219 ifa->ifa_broadaddr != NULL) { 220 broadaddr = ifa->ifa_broadaddr; 221 broadaddr_size = SA_LEN(broadaddr); 222 } else { 223 broadaddr = NULL; 224 broadaddr_size = 0; 225 } 226 if (ifa->ifa_flags & IFF_POINTOPOINT && 227 ifa->ifa_dstaddr != NULL) { 228 dstaddr = ifa->ifa_dstaddr; 229 dstaddr_size = SA_LEN(ifa->ifa_dstaddr); 230 } else { 231 dstaddr = NULL; 232 dstaddr_size = 0; 233 } 234 235 /* 236 * If this entry has a colon followed by a number at 237 * the end, we assume it's a logical interface. Those 238 * are just the way you assign multiple IP addresses to 239 * a real interface on Linux, so an entry for a logical 240 * interface should be treated like the entry for the 241 * real interface; we do that by stripping off the ":" 242 * and the number. 243 * 244 * XXX - should we do this only on Linux? 245 */ 246 p = strchr(ifa->ifa_name, ':'); 247 if (p != NULL) { 248 /* 249 * We have a ":"; is it followed by a number? 250 */ 251 q = p + 1; 252 while (isdigit((unsigned char)*q)) 253 q++; 254 if (*q == '\0') { 255 /* 256 * All digits after the ":" until the end. 257 * Strip off the ":" and everything after 258 * it. 259 */ 260 *p = '\0'; 261 } 262 } 263 264 /* 265 * Add information for this address to the list. 266 */ 267 if (add_addr_to_iflist(&devlist, ifa->ifa_name, 268 ifa->ifa_flags, addr, addr_size, netmask, addr_size, 269 broadaddr, broadaddr_size, dstaddr, dstaddr_size, 270 errbuf) < 0) { 271 ret = -1; 272 break; 273 } 274 } 275 276 freeifaddrs(ifap); 277 278 if (ret != -1) { 279 /* 280 * We haven't had any errors yet; do any platform-specific 281 * operations to add devices. 282 */ 283 if (pcap_platform_finddevs(&devlist, errbuf) < 0) 284 ret = -1; 285 } 286 287 if (ret == -1) { 288 /* 289 * We had an error; free the list we've been constructing. 290 */ 291 if (devlist != NULL) { 292 pcap_freealldevs(devlist); 293 devlist = NULL; 294 } 295 } 296 297 *alldevsp = devlist; 298 return (ret); 299 } 300