1 files changed, 155 insertions, 28 deletions

diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c
index fe9ca94ddee2..02d96f224c60 100644
--- a/net/batman-adv/sysfs.c
+++ b/net/batman-adv/sysfs.c
@@ -37,6 +37,7 @@
 #include <linux/stddef.h>
 #include <linux/string.h>
 #include <linux/stringify.h>
+#include <linux/workqueue.h>
 
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
@@ -428,6 +429,13 @@ static ssize_t batadv_show_gw_mode(struct kobject *kobj, struct attribute *attr,
 	struct batadv_priv *bat_priv = batadv_kobj_to_batpriv(kobj);
 	int bytes_written;
 
+	/* GW mode is not available if the routing algorithm in use does not
+	 * implement the GW API
+	 */
+	if (!bat_priv->algo_ops->gw.get_best_gw_node ||
+	    !bat_priv->algo_ops->gw.is_eligible)
+		return -ENOENT;
+
 	switch (atomic_read(&bat_priv->gw.mode)) {
 	case BATADV_GW_MODE_CLIENT:
 		bytes_written = sprintf(buff, "%s\n",
@@ -455,6 +463,13 @@ static ssize_t batadv_store_gw_mode(struct kobject *kobj,
 	char *curr_gw_mode_str;
 	int gw_mode_tmp = -1;
 
+	/* toggling GW mode is allowed only if the routing algorithm in use
+	 * provides the GW API
+	 */
+	if (!bat_priv->algo_ops->gw.get_best_gw_node ||
+	    !bat_priv->algo_ops->gw.is_eligible)
+		return -EINVAL;
+
 	if (buff[count - 1] == '\n')
 		buff[count - 1] = '\0';
 
@@ -514,6 +529,50 @@ static ssize_t batadv_store_gw_mode(struct kobject *kobj,
 	return count;
 }
 
+static ssize_t batadv_show_gw_sel_class(struct kobject *kobj,
+					struct attribute *attr, char *buff)
+{
+	struct batadv_priv *bat_priv = batadv_kobj_to_batpriv(kobj);
+
+	/* GW selection class is not available if the routing algorithm in use
+	 * does not implement the GW API
+	 */
+	if (!bat_priv->algo_ops->gw.get_best_gw_node ||
+	    !bat_priv->algo_ops->gw.is_eligible)
+		return -ENOENT;
+
+	if (bat_priv->algo_ops->gw.show_sel_class)
+		return bat_priv->algo_ops->gw.show_sel_class(bat_priv, buff);
+
+	return sprintf(buff, "%i\n", atomic_read(&bat_priv->gw.sel_class));
+}
+
+static ssize_t batadv_store_gw_sel_class(struct kobject *kobj,
+					 struct attribute *attr, char *buff,
+					 size_t count)
+{
+	struct batadv_priv *bat_priv = batadv_kobj_to_batpriv(kobj);
+
+	/* setting the GW selection class is allowed only if the routing
+	 * algorithm in use implements the GW API
+	 */
+	if (!bat_priv->algo_ops->gw.get_best_gw_node ||
+	    !bat_priv->algo_ops->gw.is_eligible)
+		return -EINVAL;
+
+	if (buff[count - 1] == '\n')
+		buff[count - 1] = '\0';
+
+	if (bat_priv->algo_ops->gw.store_sel_class)
+		return bat_priv->algo_ops->gw.store_sel_class(bat_priv, buff,
+							      count);
+
+	return __batadv_store_uint_attr(buff, count, 1, BATADV_TQ_MAX_VALUE,
+					batadv_post_gw_reselect, attr,
+					&bat_priv->gw.sel_class,
+					bat_priv->soft_iface);
+}
+
 static ssize_t batadv_show_gw_bwidth(struct kobject *kobj,
 				     struct attribute *attr, char *buff)
 {
@@ -625,8 +684,8 @@ BATADV_ATTR_SIF_UINT(orig_interval, orig_interval, S_IRUGO | S_IWUSR,
 		     2 * BATADV_JITTER, INT_MAX, NULL);
 BATADV_ATTR_SIF_UINT(hop_penalty, hop_penalty, S_IRUGO | S_IWUSR, 0,
 		     BATADV_TQ_MAX_VALUE, NULL);
-BATADV_ATTR_SIF_UINT(gw_sel_class, gw.sel_class, S_IRUGO | S_IWUSR, 1,
-		     BATADV_TQ_MAX_VALUE, batadv_post_gw_reselect);
+static BATADV_ATTR(gw_sel_class, S_IRUGO | S_IWUSR, batadv_show_gw_sel_class,
+		   batadv_store_gw_sel_class);
 static BATADV_ATTR(gw_bandwidth, S_IRUGO | S_IWUSR, batadv_show_gw_bwidth,
 		   batadv_store_gw_bwidth);
 #ifdef CONFIG_BATMAN_ADV_MCAST
@@ -712,6 +771,8 @@ rem_attr:
 	for (bat_attr = batadv_mesh_attrs; *bat_attr; ++bat_attr)
 		sysfs_remove_file(bat_priv->mesh_obj, &((*bat_attr)->attr));
 
+	kobject_uevent(bat_priv->mesh_obj, KOBJ_REMOVE);
+	kobject_del(bat_priv->mesh_obj);
 	kobject_put(bat_priv->mesh_obj);
 	bat_priv->mesh_obj = NULL;
 out:
@@ -726,6 +787,8 @@ void batadv_sysfs_del_meshif(struct net_device *dev)
 	for (bat_attr = batadv_mesh_attrs; *bat_attr; ++bat_attr)
 		sysfs_remove_file(bat_priv->mesh_obj, &((*bat_attr)->attr));
 
+	kobject_uevent(bat_priv->mesh_obj, KOBJ_REMOVE);
+	kobject_del(bat_priv->mesh_obj);
 	kobject_put(bat_priv->mesh_obj);
 	bat_priv->mesh_obj = NULL;
 }
@@ -781,6 +844,10 @@ rem_attr:
 	for (bat_attr = batadv_vlan_attrs; *bat_attr; ++bat_attr)
 		sysfs_remove_file(vlan->kobj, &((*bat_attr)->attr));
 
+	if (vlan->kobj != bat_priv->mesh_obj) {
+		kobject_uevent(vlan->kobj, KOBJ_REMOVE);
+		kobject_del(vlan->kobj);
+	}
 	kobject_put(vlan->kobj);
 	vlan->kobj = NULL;
 out:
@@ -800,6 +867,10 @@ void batadv_sysfs_del_vlan(struct batadv_priv *bat_priv,
 	for (bat_attr = batadv_vlan_attrs; *bat_attr; ++bat_attr)
 		sysfs_remove_file(vlan->kobj, &((*bat_attr)->attr));
 
+	if (vlan->kobj != bat_priv->mesh_obj) {
+		kobject_uevent(vlan->kobj, KOBJ_REMOVE);
+		kobject_del(vlan->kobj);
+	}
 	kobject_put(vlan->kobj);
 	vlan->kobj = NULL;
 }
@@ -828,31 +899,31 @@ static ssize_t batadv_show_mesh_iface(struct kobject *kobj,
 	return length;
 }
 
-static ssize_t batadv_store_mesh_iface(struct kobject *kobj,
-				       struct attribute *attr, char *buff,
-				       size_t count)
+/**
+ * batadv_store_mesh_iface_finish - store new hardif mesh_iface state
+ * @net_dev: netdevice to add/remove to/from batman-adv soft-interface
+ * @ifname: name of soft-interface to modify
+ *
+ * Changes the parts of the hard+soft interface which can not be modified under
+ * sysfs lock (to prevent deadlock situations).
+ *
+ * Return: 0 on success, 0 < on failure
+ */
+static int batadv_store_mesh_iface_finish(struct net_device *net_dev,
+					  char ifname[IFNAMSIZ])
 {
-	struct net_device *net_dev = batadv_kobj_to_netdev(kobj);
 	struct net *net = dev_net(net_dev);
 	struct batadv_hard_iface *hard_iface;
-	int status_tmp = -1;
-	int ret = count;
+	int status_tmp;
+	int ret = 0;
+
+	ASSERT_RTNL();
 
 	hard_iface = batadv_hardif_get_by_netdev(net_dev);
 	if (!hard_iface)
-		return count;
-
-	if (buff[count - 1] == '\n')
-		buff[count - 1] = '\0';
-
-	if (strlen(buff) >= IFNAMSIZ) {
-		pr_err("Invalid parameter for 'mesh_iface' setting received: interface name too long '%s'\n",
-		       buff);
-		batadv_hardif_put(hard_iface);
-		return -EINVAL;
-	}
+		return 0;
 
-	if (strncmp(buff, "none", 4) == 0)
+	if (strncmp(ifname, "none", 4) == 0)
 		status_tmp = BATADV_IF_NOT_IN_USE;
 	else
 		status_tmp = BATADV_IF_I_WANT_YOU;
@@ -861,15 +932,13 @@ static ssize_t batadv_store_mesh_iface(struct kobject *kobj,
 		goto out;
 
 	if ((hard_iface->soft_iface) &&
-	    (strncmp(hard_iface->soft_iface->name, buff, IFNAMSIZ) == 0))
+	    (strncmp(hard_iface->soft_iface->name, ifname, IFNAMSIZ) == 0))
 		goto out;
 
-	rtnl_lock();
-
 	if (status_tmp == BATADV_IF_NOT_IN_USE) {
 		batadv_hardif_disable_interface(hard_iface,
 						BATADV_IF_CLEANUP_AUTO);
-		goto unlock;
+		goto out;
 	}
 
 	/* if the interface already is in use */
@@ -877,15 +946,71 @@ static ssize_t batadv_store_mesh_iface(struct kobject *kobj,
 		batadv_hardif_disable_interface(hard_iface,
 						BATADV_IF_CLEANUP_AUTO);
 
-	ret = batadv_hardif_enable_interface(hard_iface, net, buff);
-
-unlock:
-	rtnl_unlock();
+	ret = batadv_hardif_enable_interface(hard_iface, net, ifname);
 out:
 	batadv_hardif_put(hard_iface);
 	return ret;
 }
 
+/**
+ * batadv_store_mesh_iface_work - store new hardif mesh_iface state
+ * @work: work queue item
+ *
+ * Changes the parts of the hard+soft interface which can not be modified under
+ * sysfs lock (to prevent deadlock situations).
+ */
+static void batadv_store_mesh_iface_work(struct work_struct *work)
+{
+	struct batadv_store_mesh_work *store_work;
+	int ret;
+
+	store_work = container_of(work, struct batadv_store_mesh_work, work);
+
+	rtnl_lock();
+	ret = batadv_store_mesh_iface_finish(store_work->net_dev,
+					     store_work->soft_iface_name);
+	rtnl_unlock();
+
+	if (ret < 0)
+		pr_err("Failed to store new mesh_iface state %s for %s: %d\n",
+		       store_work->soft_iface_name, store_work->net_dev->name,
+		       ret);
+
+	dev_put(store_work->net_dev);
+	kfree(store_work);
+}
+
+static ssize_t batadv_store_mesh_iface(struct kobject *kobj,
+				       struct attribute *attr, char *buff,
+				       size_t count)
+{
+	struct net_device *net_dev = batadv_kobj_to_netdev(kobj);
+	struct batadv_store_mesh_work *store_work;
+
+	if (buff[count - 1] == '\n')
+		buff[count - 1] = '\0';
+
+	if (strlen(buff) >= IFNAMSIZ) {
+		pr_err("Invalid parameter for 'mesh_iface' setting received: interface name too long '%s'\n",
+		       buff);
+		return -EINVAL;
+	}
+
+	store_work = kmalloc(sizeof(*store_work), GFP_KERNEL);
+	if (!store_work)
+		return -ENOMEM;
+
+	dev_hold(net_dev);
+	INIT_WORK(&store_work->work, batadv_store_mesh_iface_work);
+	store_work->net_dev = net_dev;
+	strlcpy(store_work->soft_iface_name, buff,
+		sizeof(store_work->soft_iface_name));
+
+	queue_work(batadv_event_workqueue, &store_work->work);
+
+	return count;
+}
+
 static ssize_t batadv_show_iface_status(struct kobject *kobj,
 					struct attribute *attr, char *buff)
 {
@@ -1048,6 +1173,8 @@ out:
 
 void batadv_sysfs_del_hardif(struct kobject **hardif_obj)
 {
+	kobject_uevent(*hardif_obj, KOBJ_REMOVE);
+	kobject_del(*hardif_obj);
 	kobject_put(*hardif_obj);
 	*hardif_obj = NULL;
 }