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/* iface_monitor.c
* interface monitor by Pontus Fuchs <pontus.fuchs@gmail.com>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#ifdef HAVE_LIBPCAP
#include "iface_monitor.h"
#ifdef HAVE_LIBNL
#include <stdio.h>
#include <strings.h>
#include <errno.h>
#include <net/if.h>
#include <netlink/msg.h>
#include <netlink/attr.h>
#include <netlink/route/link.h>
/* libnl 1.x compatibility code */
#ifdef HAVE_LIBNL1
#define nl_sock nl_handle
#define nl_socket_disable_seq_check nl_disable_sequence_check
static inline struct nl_handle *nl_socket_alloc(void)
{
return nl_handle_alloc();
}
static inline void nl_socket_free(struct nl_sock *h)
{
nl_handle_destroy(h);
}
#endif /* HAVE_LIBNL1 */
static struct nl_sock *iface_mon_sock;
static void
iface_mon_handler2(struct nl_object *obj, void *arg)
{
struct rtnl_link *filter;
struct rtnl_link *link_obj;
int flags, up;
char *ifname;
iface_mon_cb cb = arg;
filter = rtnl_link_alloc();
if (!filter) {
fprintf(stderr, "error allocating filter\n");
return;
}
if (nl_object_match_filter (obj, OBJ_CAST (filter)) == 0) {
rtnl_link_put(filter);
return;
}
link_obj = (struct rtnl_link *) obj;
flags = rtnl_link_get_flags (link_obj);
ifname = rtnl_link_get_name(link_obj);
up = (flags & IFF_UP) ? 1 : 0;
cb(ifname, up);
rtnl_link_put(filter);
return;
}
static int
iface_mon_handler(struct nl_msg *msg, void *arg)
{
nl_msg_parse (msg, &iface_mon_handler2, arg);
return 0;
}
static int
iface_mon_nl_init(void *arg)
{
int err;
iface_mon_sock = nl_socket_alloc();
if (!iface_mon_sock) {
fprintf(stderr, "Failed to allocate netlink socket.\n");
return -ENOMEM;
}
nl_socket_disable_seq_check(iface_mon_sock);
nl_socket_modify_cb(iface_mon_sock, NL_CB_VALID, NL_CB_CUSTOM, iface_mon_handler, arg);
if (nl_connect(iface_mon_sock, NETLINK_ROUTE)) {
fprintf(stderr, "Failed to connect to generic netlink.\n");
err = -ENOLINK;
goto out_handle_destroy;
}
nl_socket_add_membership(iface_mon_sock, RTNLGRP_LINK);
return 0;
out_handle_destroy:
nl_socket_free(iface_mon_sock);
return err;
}
void
iface_mon_event(void)
{
nl_recvmsgs_default(iface_mon_sock);
}
int
iface_mon_get_sock(void)
{
return nl_socket_get_fd(iface_mon_sock);
}
int
iface_mon_start(iface_mon_cb cb)
{
return iface_mon_nl_init(cb);
}
void
iface_mon_stop(void)
{
if(iface_mon_sock)
nl_socket_free(iface_mon_sock);
iface_mon_sock = NULL;
}
#else /* HAVE_LIBNL */
int
iface_mon_start(iface_mon_cb cb _U_)
{
return -1;
}
void
iface_mon_stop(void)
{
}
int
iface_mon_get_sock(void)
{
return -1;
}
void
iface_mon_event(void)
{
}
#endif /* HAVE_LIBNL */
#endif /* HAVE_LIBPCAP */
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