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