The Tcpdump Group git mirrors - libpcap/blob - fad-getad.c

   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[] =
  37     "@(#) $Header: /tcpdump/master/libpcap/fad-getad.c,v 1.1 2002-07-27 18:46:21 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
  47 #include <errno.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <ifaddrs.h>
  51
  52 #include "pcap-int.h"
  53
  54 #ifdef HAVE_OS_PROTO_H
  55 #include "os-proto.h"
  56 #endif
  57
  58 /*
  59  * Get a list of all interfaces that are up and that we can open.
  60  * Returns -1 on error, 0 otherwise.
  61  * The list, as returned through "alldevsp", may be null if no interfaces
  62  * were up and could be opened.
  63  *
  64  * This is the implementation used on platforms that have "getifaddrs()".
  65  */
  66 int
  67 pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
  68 {
  69         pcap_if_t *devlist = NULL;
  70         struct ifaddrs *ifap, *ifa;
  71         struct sockaddr *broadaddr, *dstaddr;
  72         int ret = 0;
  73
  74         /*
  75          * Get the list of interface addresses.
  76          *
  77          * Note: this won't return information about interfaces
  78          * with no addresses; are there any such interfaces
  79          * that would be capable of receiving packets?
  80          * (Interfaces incapable of receiving packets aren't
  81          * very interesting from libpcap's point of view.)
  82          *
  83          * LAN interfaces will probably have link-layer
  84          * addresses; I don't know whether all implementations
  85          * of "getifaddrs()" now, or in the future, will return
  86          * those.
  87          */
  88         if (getifaddrs(&ifap) != 0) {
  89                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
  90                     "getifaddrs: %s", pcap_strerror(errno));
  91                 return (-1);
  92         }
  93         for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
  94                 /*
  95                  * Is this interface up?
  96                  */
  97                 if (!(ifa->ifa_flags & IFF_UP)) {
  98                         /*
  99                          * No, so don't add it to the list.
 100                          */
 101                         continue;
 102                 }
 103
 104                 /*
 105                  * "ifa_broadaddr" may be non-null even on
 106                  * non-broadcast interfaces; "ifa_dstaddr"
 107                  * was, on at least one FreeBSD 4.1 system,
 108                  * non-null on a non-point-to-point
 109                  * interface.
 110                  */
 111                 if (ifa->ifa_flags & IFF_BROADCAST)
 112                         broadaddr = ifa->ifa_broadaddr;
 113                 else
 114                         broadaddr = NULL;
 115                 if (ifa->ifa_flags & IFF_POINTOPOINT)
 116                         dstaddr = ifa->ifa_dstaddr;
 117                 else
 118                         dstaddr = NULL;
 119
 120                 /*
 121                  * Add information for this address to the list.
 122                  */
 123                 if (add_addr_to_iflist(&devlist, ifa->ifa_name,
 124                     ifa->ifa_flags, ifa->ifa_addr, ifa->ifa_netmask,
 125                     broadaddr, dstaddr, errbuf) < 0) {
 126                         ret = -1;
 127                         break;
 128                 }
 129         }
 130
 131         freeifaddrs(ifap);
 132
 133         if (ret != -1) {
 134                 /*
 135                  * We haven't had any errors yet; do any platform-specific
 136                  * operations to add devices.
 137                  */
 138                 if (pcap_platform_finddevs(&devlist, errbuf) < 0)
 139                         ret = -1;
 140         }
 141
 142         if (ret == -1) {
 143                 /*
 144                  * We had an error; free the list we've been constructing.
 145                  */
 146                 if (devlist != NULL) {
 147                         pcap_freealldevs(devlist);
 148                         devlist = NULL;
 149                 }
 150         }
 151
 152         *alldevsp = devlist;
 153         return (ret);
 154 }