/* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */ /* * Copyright (c) 1994, 1995, 1996, 1997, 1998 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the Computer Systems * Engineering Group at Lawrence Berkeley Laboratory. * 4. Neither the name of the University nor of the Laboratory may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char rcsid[] _U_ = "@(#) $Header: /tcpdump/master/libpcap/fad-getad.c,v 1.10.2.1 2005/04/10 18:04:49 hannes Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #include #include #include #include "pcap-int.h" #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif #ifdef AF_PACKET # include #endif /* * This is fun. * * In older BSD systems, socket addresses were fixed-length, and * "sizeof (struct sockaddr)" gave the size of the structure. * All addresses fit within a "struct sockaddr". * * In newer BSD systems, the socket address is variable-length, and * there's an "sa_len" field giving the length of the structure; * this allows socket addresses to be longer than 2 bytes of family * and 14 bytes of data. * * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553 * variant of the old BSD scheme (with "struct sockaddr_storage" rather * than "struct sockaddr"), and some use the new BSD scheme. * * Some versions of GNU libc use neither scheme, but has an "SA_LEN()" * macro that determines the size based on the address family. Other * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553 * but not in the final version). On the latter systems, we explicitly * check the AF_ type to determine the length; we assume that on * all those systems we have "struct sockaddr_storage". */ #ifndef SA_LEN #ifdef HAVE_SOCKADDR_SA_LEN #define SA_LEN(addr) ((addr)->sa_len) #else /* HAVE_SOCKADDR_SA_LEN */ #ifdef HAVE_SOCKADDR_STORAGE static size_t get_sa_len(struct sockaddr *addr) { switch (addr->sa_family) { #ifdef AF_INET case AF_INET: return (sizeof (struct sockaddr_in)); #endif #ifdef AF_INET6 case AF_INET6: return (sizeof (struct sockaddr_in6)); #endif #ifdef AF_PACKET case AF_PACKET: return (sizeof (struct sockaddr_ll)); #endif default: return (sizeof (struct sockaddr)); } } #define SA_LEN(addr) (get_sa_len(addr)) #else /* HAVE_SOCKADDR_STORAGE */ #define SA_LEN(addr) (sizeof (struct sockaddr)) #endif /* HAVE_SOCKADDR_STORAGE */ #endif /* HAVE_SOCKADDR_SA_LEN */ #endif /* SA_LEN */ /* * Get a list of all interfaces that are up and that we can open. * Returns -1 on error, 0 otherwise. * The list, as returned through "alldevsp", may be null if no interfaces * were up and could be opened. * * This is the implementation used on platforms that have "getifaddrs()". */ int pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf) { pcap_if_t *devlist = NULL; struct ifaddrs *ifap, *ifa; struct sockaddr *addr, *netmask, *broadaddr, *dstaddr; size_t addr_size, broadaddr_size, dstaddr_size; int ret = 0; char *p, *q; /* * Get the list of interface addresses. * * Note: this won't return information about interfaces * with no addresses; are there any such interfaces * that would be capable of receiving packets? * (Interfaces incapable of receiving packets aren't * very interesting from libpcap's point of view.) * * LAN interfaces will probably have link-layer * addresses; I don't know whether all implementations * of "getifaddrs()" now, or in the future, will return * those. */ if (getifaddrs(&ifap) != 0) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "getifaddrs: %s", pcap_strerror(errno)); return (-1); } for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) { /* * Is this interface up? */ if (!(ifa->ifa_flags & IFF_UP)) { /* * No, so don't add it to the list. */ continue; } /* * "ifa_addr" was apparently null on at least one * interface on some system. * * "ifa_broadaddr" may be non-null even on * non-broadcast interfaces, and was null on * at least one OpenBSD 3.4 system on at least * one interface with IFF_BROADCAST set. * * "ifa_dstaddr" was, on at least one FreeBSD 4.1 * system, non-null on a non-point-to-point * interface. * * Therefore, we supply the address and netmask only * if "ifa_addr" is non-null (if there's no address, * there's obviously no netmask), and supply the * broadcast and destination addresses if the appropriate * flag is set *and* the appropriate "ifa_" entry doesn't * evaluate to a null pointer. */ if (ifa->ifa_addr != NULL) { addr = ifa->ifa_addr; addr_size = SA_LEN(addr); netmask = ifa->ifa_netmask; } else { addr = NULL; addr_size = 0; netmask = NULL; } if (ifa->ifa_flags & IFF_BROADCAST && ifa->ifa_broadaddr != NULL) { broadaddr = ifa->ifa_broadaddr; broadaddr_size = SA_LEN(broadaddr); } else { broadaddr = NULL; broadaddr_size = 0; } if (ifa->ifa_flags & IFF_POINTOPOINT && ifa->ifa_dstaddr != NULL) { dstaddr = ifa->ifa_dstaddr; dstaddr_size = SA_LEN(ifa->ifa_dstaddr); } else { dstaddr = NULL; dstaddr_size = 0; } /* * If this entry has a colon followed by a number at * the end, we assume it's a logical interface. Those * are just the way you assign multiple IP addresses to * a real interface on Linux, so an entry for a logical * interface should be treated like the entry for the * real interface; we do that by stripping off the ":" * and the number. * * XXX - should we do this only on Linux? */ p = strchr(ifa->ifa_name, ':'); if (p != NULL) { /* * We have a ":"; is it followed by a number? */ q = p + 1; while (isdigit((unsigned char)*q)) q++; if (*q == '\0') { /* * All digits after the ":" until the end. * Strip off the ":" and everything after * it. */ *p = '\0'; } } /* * Add information for this address to the list. */ if (add_addr_to_iflist(&devlist, ifa->ifa_name, ifa->ifa_flags, addr, addr_size, netmask, addr_size, broadaddr, broadaddr_size, dstaddr, dstaddr_size, errbuf) < 0) { ret = -1; break; } } freeifaddrs(ifap); if (ret != -1) { /* * We haven't had any errors yet; do any platform-specific * operations to add devices. */ if (pcap_platform_finddevs(&devlist, errbuf) < 0) ret = -1; } if (ret == -1) { /* * We had an error; free the list we've been constructing. */ if (devlist != NULL) { pcap_freealldevs(devlist); devlist = NULL; } } *alldevsp = devlist; return (ret); }