1 /* $NetBSD: fad-getad.c,v 1.1.1.4 2013/12/31 16:57:24 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 /* 66 * We don't do this on Solaris 11 and later, as it appears there aren't 67 * any AF_PACKET addresses on interfaces, so we don't need this, and 68 * we end up including both the OS's <net/bpf.h> and our <pcap/bpf.h>, 69 * and their definitions of some data structures collide. 70 */ 71 #if (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET) 72 # ifdef HAVE_NETPACKET_PACKET_H 73 /* Linux distributions with newer glibc */ 74 # include <netpacket/packet.h> 75 # else /* HAVE_NETPACKET_PACKET_H */ 76 /* LynxOS, Linux distributions with older glibc */ 77 # ifdef __Lynx__ 78 /* LynxOS */ 79 # include <netpacket/if_packet.h> 80 # else /* __Lynx__ */ 81 /* Linux */ 82 # include <linux/types.h> 83 # include <linux/if_packet.h> 84 # endif /* __Lynx__ */ 85 # endif /* HAVE_NETPACKET_PACKET_H */ 86 #endif /* (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET) */ 87 88 /* 89 * This is fun. 90 * 91 * In older BSD systems, socket addresses were fixed-length, and 92 * "sizeof (struct sockaddr)" gave the size of the structure. 93 * All addresses fit within a "struct sockaddr". 94 * 95 * In newer BSD systems, the socket address is variable-length, and 96 * there's an "sa_len" field giving the length of the structure; 97 * this allows socket addresses to be longer than 2 bytes of family 98 * and 14 bytes of data. 99 * 100 * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553 101 * variant of the old BSD scheme (with "struct sockaddr_storage" rather 102 * than "struct sockaddr"), and some use the new BSD scheme. 103 * 104 * Some versions of GNU libc use neither scheme, but has an "SA_LEN()" 105 * macro that determines the size based on the address family. Other 106 * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553 107 * but not in the final version). On the latter systems, we explicitly 108 * check the AF_ type to determine the length; we assume that on 109 * all those systems we have "struct sockaddr_storage". 110 */ 111 #ifndef SA_LEN 112 #ifdef HAVE_SOCKADDR_SA_LEN 113 #define SA_LEN(addr) ((addr)->sa_len) 114 #else /* HAVE_SOCKADDR_SA_LEN */ 115 #ifdef HAVE_SOCKADDR_STORAGE 116 static size_t 117 get_sa_len(struct sockaddr *addr) 118 { 119 switch (addr->sa_family) { 120 121 #ifdef AF_INET 122 case AF_INET: 123 return (sizeof (struct sockaddr_in)); 124 #endif 125 126 #ifdef AF_INET6 127 case AF_INET6: 128 return (sizeof (struct sockaddr_in6)); 129 #endif 130 131 #if (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET) 132 case AF_PACKET: 133 return (sizeof (struct sockaddr_ll)); 134 #endif 135 136 default: 137 return (sizeof (struct sockaddr)); 138 } 139 } 140 #define SA_LEN(addr) (get_sa_len(addr)) 141 #else /* HAVE_SOCKADDR_STORAGE */ 142 #define SA_LEN(addr) (sizeof (struct sockaddr)) 143 #endif /* HAVE_SOCKADDR_STORAGE */ 144 #endif /* HAVE_SOCKADDR_SA_LEN */ 145 #endif /* SA_LEN */ 146 147 /* 148 * Get a list of all interfaces that are up and that we can open. 149 * Returns -1 on error, 0 otherwise. 150 * The list, as returned through "alldevsp", may be null if no interfaces 151 * were up and could be opened. 152 */ 153 int 154 pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf) 155 { 156 pcap_if_t *devlist = NULL; 157 struct ifaddrs *ifap, *ifa; 158 struct sockaddr *addr, *netmask, *broadaddr, *dstaddr; 159 size_t addr_size, broadaddr_size, dstaddr_size; 160 int ret = 0; 161 char *p, *q; 162 163 /* 164 * Get the list of interface addresses. 165 * 166 * Note: this won't return information about interfaces 167 * with no addresses; are there any such interfaces 168 * that would be capable of receiving packets? 169 * (Interfaces incapable of receiving packets aren't 170 * very interesting from libpcap's point of view.) 171 * 172 * LAN interfaces will probably have link-layer 173 * addresses; I don't know whether all implementations 174 * of "getifaddrs()" now, or in the future, will return 175 * those. 176 */ 177 if (getifaddrs(&ifap) != 0) { 178 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 179 "getifaddrs: %s", pcap_strerror(errno)); 180 return (-1); 181 } 182 for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) { 183 /* 184 * Is this interface up? 185 */ 186 if (!(ifa->ifa_flags & IFF_UP)) { 187 /* 188 * No, so don't add it to the list. 189 */ 190 continue; 191 } 192 193 /* 194 * "ifa_addr" was apparently null on at least one 195 * interface on some system. 196 * 197 * "ifa_broadaddr" may be non-null even on 198 * non-broadcast interfaces, and was null on 199 * at least one OpenBSD 3.4 system on at least 200 * one interface with IFF_BROADCAST set. 201 * 202 * "ifa_dstaddr" was, on at least one FreeBSD 4.1 203 * system, non-null on a non-point-to-point 204 * interface. 205 * 206 * Therefore, we supply the address and netmask only 207 * if "ifa_addr" is non-null (if there's no address, 208 * there's obviously no netmask), and supply the 209 * broadcast and destination addresses if the appropriate 210 * flag is set *and* the appropriate "ifa_" entry doesn't 211 * evaluate to a null pointer. 212 */ 213 if (ifa->ifa_addr != NULL) { 214 addr = ifa->ifa_addr; 215 addr_size = SA_LEN(addr); 216 netmask = ifa->ifa_netmask; 217 } else { 218 addr = NULL; 219 addr_size = 0; 220 netmask = NULL; 221 } 222 if (ifa->ifa_flags & IFF_BROADCAST && 223 ifa->ifa_broadaddr != NULL) { 224 broadaddr = ifa->ifa_broadaddr; 225 broadaddr_size = SA_LEN(broadaddr); 226 } else { 227 broadaddr = NULL; 228 broadaddr_size = 0; 229 } 230 if (ifa->ifa_flags & IFF_POINTOPOINT && 231 ifa->ifa_dstaddr != NULL) { 232 dstaddr = ifa->ifa_dstaddr; 233 dstaddr_size = SA_LEN(ifa->ifa_dstaddr); 234 } else { 235 dstaddr = NULL; 236 dstaddr_size = 0; 237 } 238 239 /* 240 * If this entry has a colon followed by a number at 241 * the end, we assume it's a logical interface. Those 242 * are just the way you assign multiple IP addresses to 243 * a real interface on Linux, so an entry for a logical 244 * interface should be treated like the entry for the 245 * real interface; we do that by stripping off the ":" 246 * and the number. 247 * 248 * XXX - should we do this only on Linux? 249 */ 250 p = strchr(ifa->ifa_name, ':'); 251 if (p != NULL) { 252 /* 253 * We have a ":"; is it followed by a number? 254 */ 255 q = p + 1; 256 while (isdigit((unsigned char)*q)) 257 q++; 258 if (*q == '\0') { 259 /* 260 * All digits after the ":" until the end. 261 * Strip off the ":" and everything after 262 * it. 263 */ 264 *p = '\0'; 265 } 266 } 267 268 /* 269 * Add information for this address to the list. 270 */ 271 if (add_addr_to_iflist(&devlist, ifa->ifa_name, 272 ifa->ifa_flags, addr, addr_size, netmask, addr_size, 273 broadaddr, broadaddr_size, dstaddr, dstaddr_size, 274 errbuf) < 0) { 275 ret = -1; 276 break; 277 } 278 } 279 280 freeifaddrs(ifap); 281 282 if (ret == -1) { 283 /* 284 * We had an error; free the list we've been constructing. 285 */ 286 if (devlist != NULL) { 287 pcap_freealldevs(devlist); 288 devlist = NULL; 289 } 290 } 291 292 *alldevsp = devlist; 293 return (ret); 294 } 295