core: Add tracking of network interfaces via RTNL

Makefile.am

@@ -38,6 +38,7 @@ bin_PROGRAMS = src/iwd client/iwctl
 
 src_iwd_SOURCES = src/main.c linux/nl80211.h linux/kdbus.h \
 					src/kdbus.h src/kdbus.c \
+					src/netdev.h src/netdev.c \
 					src/sha1.h src/sha1.c
 src_iwd_LDADD = ell/libell-internal.la
 

src/main.c

@@ -77,8 +77,15 @@ int main(int argc, char *argv[])
 		goto destroy;
 	}
 
+	if (!netdev_init()) {
+		exit_status = EXIT_FAILURE;
+		goto destroy;
+	}
+
 	l_main_run();
 
+	netdev_exit();
+
 	exit_status = EXIT_SUCCESS;
 
 destroy:

src/netdev.c

@@ -0,0 +1,174 @@
+/*
+ *
+ *  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 <linux/rtnetlink.h>
+#include <net/if_arp.h>
+#include <net/if.h>
+#include <ell/ell.h>
+
+struct netdev_data {
+	uint32_t index;
+	uint32_t flags;
+	char ifname[IF_NAMESIZE];
+};
+
+static struct l_netlink *rtnl = NULL;
+static struct l_hashmap *netdev_list = NULL;
+
+static void do_debug(const char *str, void *user_data)
+{
+	const char *prefix = user_data;
+
+	l_info("%s%s", prefix, str);
+}
+
+static void free_netdev_data(void *user_data)
+{
+	struct netdev_data *netdev = user_data;
+
+	l_free(netdev);
+}
+
+static void newlink_notify(const struct ifinfomsg *ifi, int bytes)
+{
+	struct netdev_data *netdev;
+	uint32_t index = ifi->ifi_index;
+	struct rtattr *rta;
+
+	netdev = l_hashmap_lookup(netdev_list, L_UINT_TO_PTR(index));
+	if (!netdev) {
+		netdev = l_new(struct netdev_data, 1);
+
+		netdev->index = index;
+
+		if (!l_hashmap_insert(netdev_list,
+					L_UINT_TO_PTR(index), netdev)) {
+			free_netdev_data(netdev);
+			return;
+		}
+	}
+
+	netdev->flags = ifi->ifi_flags;
+
+	for (rta = IFLA_RTA(ifi); RTA_OK(rta, bytes);
+					rta = RTA_NEXT(rta, bytes)) {
+		switch (rta->rta_type) {
+		case IFLA_IFNAME:
+			if (RTA_PAYLOAD(rta) <= IF_NAMESIZE)
+				strcpy(netdev->ifname, RTA_DATA(rta));
+			break;
+		}
+	}
+}
+
+static void dellink_notify(const struct ifinfomsg *ifi, int bytes)
+{
+	struct netdev_data *netdev;
+	uint32_t index = ifi->ifi_index;
+
+	netdev = l_hashmap_remove(netdev_list, L_UINT_TO_PTR(index));
+	if (!netdev)
+		return;
+
+	free_netdev_data(netdev);
+}
+
+static void link_notify(uint16_t type, const void *data, uint32_t len,
+							void *user_data)
+{
+	const struct ifinfomsg *ifi = data;
+	int bytes;
+
+	if (ifi->ifi_type != ARPHRD_ETHER)
+		return;
+
+	bytes = len - NLMSG_ALIGN(sizeof(struct ifinfomsg));
+
+	switch (type) {
+	case RTM_NEWLINK:
+		newlink_notify(ifi, bytes);
+		break;
+	case RTM_DELLINK:
+		dellink_notify(ifi, bytes);
+		break;
+	}
+}
+
+static void netdev_destroy(void)
+{
+	/*
+	 * 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;
+
+	l_hashmap_destroy(netdev_list, free_netdev_data);
+	netdev_list = NULL;
+}
+
+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;
+	}
+
+	l_netlink_set_debug(rtnl, do_debug, "[RTNL] ", NULL);
+
+	netdev_list = l_hashmap_new();
+
+	if (!l_netlink_register(rtnl, RTNLGRP_LINK, link_notify, NULL, NULL)) {
+		l_error("Failed to register link notification");
+		goto destroy;
+	}
+
+	return true;
+
+destroy:
+	netdev_destroy();
+
+	return false;
+}
+
+bool netdev_exit(void)
+{
+	if (!rtnl)
+		return false;
+
+	l_debug("Closing route netlink socket");
+
+	netdev_destroy();
+
+	return true;
+}

src/netdev.h

@@ -0,0 +1,26 @@
+/*
+ *
+ *  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
+ *
+ */
+
+#include <stdbool.h>
+
+bool netdev_init(void);
+bool netdev_exit(void);