/**

 * @file rtnl.h

 * @brief Interface link status via RT netlink

 * @note Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>

 *

 * 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.

 */

#ifndef HAVE_RTNL_H

#define HAVE_RTNL_H

typedef void (*rtnl_callback)(void *ctx, int linkup, int ts_index);

/**

 * Close a RT netlink socket.

 * @param fd  A socket obtained via rtnl_open().

 * @return    Zero on success, non-zero otherwise.

 */

int rtnl_close(int fd);

/**

 * Get name of the slave interface which timestamps packets going through

 * a master interface (e.g. bond0)

 * @param device    Name of the master interface.

 * @param ts_device Buffer for the name of the slave interface, which must be

 *                  at least IF_NAMESIZE bytes long.

 * @return          Zero on success, or -1 on error.

 */

int rtnl_get_ts_device(char *device, char *ts_device);

/**

 * Request the link status from the kernel.

 * @param fd     A socket obtained via rtnl_open().

 * @param device Interface name. Request all iface's status if set NULL.

 * @return       Zero on success, non-zero otherwise.

 */

int rtnl_link_query(int fd, char *device);

/**

 * Read kernel messages looking for a link up/down events.

 * @param fd     Readable socket obtained via rtnl_open().

 * @param device The device which we need to get link info.

 * @param cb     Callback function to be invoked on each event.

 * @param ctx    Private context passed to the callback.

 * @return       Zero on success, non-zero otherwise.

 */

int rtnl_link_status(int fd, char *device, rtnl_callback cb, void *ctx);

/**

 * Open a RT netlink socket for monitoring link state.

 * @return    A valid socket, or -1 on error.

 */

int rtnl_open(void);

#endif