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 36static 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#ifdef AF_PACKET 64# ifdef HAVE_NETPACKET_PACKET_H 65/* Solaris 11 and later, Linux distributions with newer glibc */ 66# include <netpacket/packet.h> 67# else /* HAVE_NETPACKET_PACKET_H */ 68/* LynxOS, Linux distributions with older glibc */ 69# ifdef __Lynx__ 70/* LynxOS */ 71# include <netpacket/if_packet.h> 72# else /* __Lynx__ */ 73/* Linux */ 74# include <linux/types.h> 75# include <linux/if_packet.h> 76# endif /* __Lynx__ */ 77# endif /* HAVE_NETPACKET_PACKET_H */ 78#endif /* AF_PACKET */ 79 80/* 81 * This is fun. 82 * 83 * In older BSD systems, socket addresses were fixed-length, and 84 * "sizeof (struct sockaddr)" gave the size of the structure. 85 * All addresses fit within a "struct sockaddr". 86 * 87 * In newer BSD systems, the socket address is variable-length, and 88 * there's an "sa_len" field giving the length of the structure; 89 * this allows socket addresses to be longer than 2 bytes of family 90 * and 14 bytes of data. 91 * 92 * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553 93 * variant of the old BSD scheme (with "struct sockaddr_storage" rather 94 * than "struct sockaddr"), and some use the new BSD scheme. 95 * 96 * Some versions of GNU libc use neither scheme, but has an "SA_LEN()" 97 * macro that determines the size based on the address family. Other 98 * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553 99 * but not in the final version). On the latter systems, we explicitly 100 * check the AF_ type to determine the length; we assume that on 101 * all those systems we have "struct sockaddr_storage". 102 */ 103#ifndef SA_LEN 104#ifdef HAVE_SOCKADDR_SA_LEN 105#define SA_LEN(addr) ((addr)->sa_len) 106#else /* HAVE_SOCKADDR_SA_LEN */ 107#ifdef HAVE_SOCKADDR_STORAGE 108static size_t 109get_sa_len(struct sockaddr *addr) 110{ 111 switch (addr->sa_family) { 112 113#ifdef AF_INET 114 case AF_INET: 115 return (sizeof (struct sockaddr_in)); 116#endif 117 118#ifdef AF_INET6 119 case AF_INET6: 120 return (sizeof (struct sockaddr_in6)); 121#endif 122 123#ifdef AF_PACKET 124 case AF_PACKET: 125 return (sizeof (struct sockaddr_ll)); 126#endif 127 128 default: 129 return (sizeof (struct sockaddr)); 130 } 131} 132#define SA_LEN(addr) (get_sa_len(addr)) 133#else /* HAVE_SOCKADDR_STORAGE */ 134#define SA_LEN(addr) (sizeof (struct sockaddr)) 135#endif /* HAVE_SOCKADDR_STORAGE */ 136#endif /* HAVE_SOCKADDR_SA_LEN */ 137#endif /* SA_LEN */ 138 139/* 140 * Get a list of all interfaces that are up and that we can open. 141 * Returns -1 on error, 0 otherwise. 142 * The list, as returned through "alldevsp", may be null if no interfaces 143 * were up and could be opened. 144 */ 145int 146pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf) 147{ 148 pcap_if_t *devlist = NULL; 149 struct ifaddrs *ifap, *ifa; 150 struct sockaddr *addr, *netmask, *broadaddr, *dstaddr; 151 size_t addr_size, broadaddr_size, dstaddr_size; 152 int ret = 0; 153 char *p, *q; 154 155 /* 156 * Get the list of interface addresses. 157 * 158 * Note: this won't return information about interfaces 159 * with no addresses; are there any such interfaces 160 * that would be capable of receiving packets? 161 * (Interfaces incapable of receiving packets aren't 162 * very interesting from libpcap's point of view.) 163 * 164 * LAN interfaces will probably have link-layer 165 * addresses; I don't know whether all implementations 166 * of "getifaddrs()" now, or in the future, will return 167 * those. 168 */ 169 if (getifaddrs(&ifap) != 0) { 170 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 171 "getifaddrs: %s", pcap_strerror(errno)); 172 return (-1); 173 } 174 for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) { 175 /* 176 * Is this interface up? 177 */ 178 if (!(ifa->ifa_flags & IFF_UP)) { 179 /* 180 * No, so don't add it to the list. 181 */ 182 continue; 183 } 184 185 /* 186 * "ifa_addr" was apparently null on at least one 187 * interface on some system. 188 * 189 * "ifa_broadaddr" may be non-null even on 190 * non-broadcast interfaces, and was null on 191 * at least one OpenBSD 3.4 system on at least 192 * one interface with IFF_BROADCAST set. 193 * 194 * "ifa_dstaddr" was, on at least one FreeBSD 4.1 195 * system, non-null on a non-point-to-point 196 * interface. 197 * 198 * Therefore, we supply the address and netmask only 199 * if "ifa_addr" is non-null (if there's no address, 200 * there's obviously no netmask), and supply the 201 * broadcast and destination addresses if the appropriate 202 * flag is set *and* the appropriate "ifa_" entry doesn't 203 * evaluate to a null pointer. 204 */ 205 if (ifa->ifa_addr != NULL) { 206 addr = ifa->ifa_addr; 207 addr_size = SA_LEN(addr); 208 netmask = ifa->ifa_netmask; 209 } else { 210 addr = NULL; 211 addr_size = 0; 212 netmask = NULL; 213 } 214 if (ifa->ifa_flags & IFF_BROADCAST && 215 ifa->ifa_broadaddr != NULL) { 216 broadaddr = ifa->ifa_broadaddr; 217 broadaddr_size = SA_LEN(broadaddr); 218 } else { 219 broadaddr = NULL; 220 broadaddr_size = 0; 221 } 222 if (ifa->ifa_flags & IFF_POINTOPOINT && 223 ifa->ifa_dstaddr != NULL) { 224 dstaddr = ifa->ifa_dstaddr; 225 dstaddr_size = SA_LEN(ifa->ifa_dstaddr); 226 } else { 227 dstaddr = NULL; 228 dstaddr_size = 0; 229 } 230 231 /* 232 * If this entry has a colon followed by a number at 233 * the end, we assume it's a logical interface. Those 234 * are just the way you assign multiple IP addresses to 235 * a real interface on Linux, so an entry for a logical 236 * interface should be treated like the entry for the 237 * real interface; we do that by stripping off the ":" 238 * and the number. 239 * 240 * XXX - should we do this only on Linux? 241 */ 242 p = strchr(ifa->ifa_name, ':'); 243 if (p != NULL) { 244 /* 245 * We have a ":"; is it followed by a number? 246 */ 247 q = p + 1; 248 while (isdigit((unsigned char)*q)) 249 q++; 250 if (*q == '\0') { 251 /* 252 * All digits after the ":" until the end. 253 * Strip off the ":" and everything after 254 * it. 255 */ 256 *p = '\0'; 257 } 258 } 259 260 /* 261 * Add information for this address to the list. 262 */ 263 if (add_addr_to_iflist(&devlist, ifa->ifa_name, 264 ifa->ifa_flags, addr, addr_size, netmask, addr_size, 265 broadaddr, broadaddr_size, dstaddr, dstaddr_size, 266 errbuf) < 0) { 267 ret = -1; 268 break; 269 } 270 } 271 272 freeifaddrs(ifap); 273 274 if (ret == -1) { 275 /* 276 * We had an error; free the list we've been constructing. 277 */ 278 if (devlist != NULL) { 279 pcap_freealldevs(devlist); 280 devlist = NULL; 281 } 282 } 283 284 *alldevsp = devlist; 285 return (ret); 286} 287