iwd/src/netdev.c

/*
 *
 *  Wireless daemon for Linux
 *
 *  Copyright (C) 2013-2014  Intel Corporation. All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <linux/rtnetlink.h>
#include <net/if_arp.h>
#include <net/if.h>
#include <linux/if_ether.h>
#include <ell/ell.h>

#include "src/wiphy.h"
#include "src/netdev.h"

static struct l_netlink *rtnl = NULL;

static void do_debug(const char *str, void *user_data)
{
	const char *prefix = user_data;

	l_info("%s%s", prefix, str);
}

struct cb_data {
	netdev_command_func_t callback;
	void *user_data;
};

static void netlink_result(int error, uint16_t type, const void *data,
			uint32_t len, void *user_data)
{
	struct cb_data *cb_data = user_data;

	if (!cb_data)
		return;

	cb_data->callback(error < 0 ? false : true, cb_data->user_data);

	l_free(cb_data);
}

static size_t rta_add_u8(void *rta_buf, unsigned short type, uint8_t value)
{
	struct rtattr *rta = rta_buf;

	rta->rta_len = RTA_LENGTH(sizeof(uint8_t));
	rta->rta_type = type;
	*((uint8_t *) RTA_DATA(rta)) = value;

	return RTA_SPACE(sizeof(uint8_t));
}

void netdev_set_linkmode_and_operstate(uint32_t ifindex,
				uint8_t linkmode, uint8_t operstate,
				netdev_command_func_t callback, void *user_data)
{
	struct ifinfomsg *rtmmsg;
	void *rta_buf;
	size_t bufsize;
	struct cb_data *cb_data = NULL;

	bufsize = NLMSG_LENGTH(sizeof(struct ifinfomsg)) +
		RTA_SPACE(sizeof(uint8_t)) + RTA_SPACE(sizeof(uint8_t));

	rtmmsg = l_malloc(bufsize);
	memset(rtmmsg, 0, bufsize);

	rtmmsg->ifi_family = AF_UNSPEC;
	rtmmsg->ifi_index = ifindex;

	rta_buf = rtmmsg + 1;

	rta_buf += rta_add_u8(rta_buf, IFLA_LINKMODE, linkmode);
	rta_buf += rta_add_u8(rta_buf, IFLA_OPERSTATE, operstate);

	if (callback) {
		cb_data = l_new(struct cb_data, 1);
		cb_data->callback = callback;
		cb_data->user_data = user_data;
	}

	l_netlink_send(rtnl, RTM_SETLINK, 0, rtmmsg,
					rta_buf - (void *) rtmmsg,
					netlink_result, cb_data, NULL);

	l_free(rtmmsg);
}

bool netdev_init(void)
{
	if (rtnl)
		return false;

	l_debug("Opening route netlink socket");

	rtnl = l_netlink_new(NETLINK_ROUTE);
	if (!rtnl) {
		l_error("Failed to open route netlink socket");
		return false;
	}

	if (getenv("IWD_RTNL_DEBUG"))
		l_netlink_set_debug(rtnl, do_debug, "[RTNL] ", NULL);

	return true;
}

bool netdev_exit(void)
{
	if (!rtnl)
		return false;

	l_debug("Closing route netlink socket");

	/*
	 * The netlink object keeps track of the registered notification
	 * callbacks and their multicast memberships. When destroying the
	 * netlink object, all resources will be freed.
	 */
	l_netlink_destroy(rtnl);
	rtnl = NULL;

	return true;
}