batman-adv: Allow to modify slaves of soft-interfaces through rntl_link

The sysfs configuration interface of batman-adv to add/remove slaves of an
soft-iface is not deadlock free and doesn't follow the currently common way to
modify slaves of an interface.

An additional configuration interface though rtnl_link is introduced which
provides easy device adding/removing with tools like "ip":
$ ip link set dev eth0 master bat0
$ ip link set dev eth0 nomaster

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 6c32607..f33ced8 100644 (file)
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -350,9 +350,13 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
        hard_iface->soft_iface = soft_iface;
        bat_priv = netdev_priv(hard_iface->soft_iface);
 
+       ret = netdev_master_upper_dev_link(hard_iface->net_dev, soft_iface);
+       if (ret)
+               goto err_dev;
+
        ret = bat_priv->bat_algo_ops->bat_iface_enable(hard_iface);
        if (ret < 0)
-               goto err_dev;
+               goto err_upper;
 
        hard_iface->if_num = bat_priv->num_ifaces;
        bat_priv->num_ifaces++;
@@ -362,7 +366,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
                bat_priv->bat_algo_ops->bat_iface_disable(hard_iface);
                bat_priv->num_ifaces--;
                hard_iface->if_status = BATADV_IF_NOT_IN_USE;
-               goto err_dev;
+               goto err_upper;
        }
 
        hard_iface->batman_adv_ptype.type = ethertype;
@@ -401,7 +405,10 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 out:
        return 0;
 
+err_upper:
+       netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 err_dev:
+       hard_iface->soft_iface = NULL;
        dev_put(soft_iface);
 err:
        batadv_hardif_free_ref(hard_iface);
@@ -450,6 +457,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
        if (!bat_priv->num_ifaces && autodel == BATADV_IF_CLEANUP_AUTO)
                batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 
+       netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
        hard_iface->soft_iface = NULL;
        batadv_hardif_free_ref(hard_iface);
 

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 545c863..403b8c4 100644 (file)
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -509,6 +509,58 @@ free_bat_counters:
        return ret;
 }
 
+/**
+ * batadv_softif_slave_add - Add a slave interface to a batadv_soft_interface
+ * @dev: batadv_soft_interface used as master interface
+ * @slave_dev: net_device which should become the slave interface
+ *
+ * Return 0 if successful or error otherwise.
+ */
+static int batadv_softif_slave_add(struct net_device *dev,
+                                  struct net_device *slave_dev)
+{
+       struct batadv_hard_iface *hard_iface;
+       int ret = -EINVAL;
+
+       hard_iface = batadv_hardif_get_by_netdev(slave_dev);
+       if (!hard_iface || hard_iface->soft_iface != NULL)
+               goto out;
+
+       ret = batadv_hardif_enable_interface(hard_iface, dev->name);
+
+out:
+       if (hard_iface)
+               batadv_hardif_free_ref(hard_iface);
+       return ret;
+}
+
+/**
+ * batadv_softif_slave_del - Delete a slave iface from a batadv_soft_interface
+ * @dev: batadv_soft_interface used as master interface
+ * @slave_dev: net_device which should be removed from the master interface
+ *
+ * Return 0 if successful or error otherwise.
+ */
+static int batadv_softif_slave_del(struct net_device *dev,
+                                  struct net_device *slave_dev)
+{
+       struct batadv_hard_iface *hard_iface;
+       int ret = -EINVAL;
+
+       hard_iface = batadv_hardif_get_by_netdev(slave_dev);
+
+       if (!hard_iface || hard_iface->soft_iface != dev)
+               goto out;
+
+       batadv_hardif_disable_interface(hard_iface, BATADV_IF_CLEANUP_KEEP);
+       ret = 0;
+
+out:
+       if (hard_iface)
+               batadv_hardif_free_ref(hard_iface);
+       return ret;
+}
+
 static const struct net_device_ops batadv_netdev_ops = {
        .ndo_init = batadv_softif_init_late,
        .ndo_open = batadv_interface_open,
@@ -517,7 +569,9 @@ static const struct net_device_ops batadv_netdev_ops = {
        .ndo_set_mac_address = batadv_interface_set_mac_addr,
        .ndo_change_mtu = batadv_interface_change_mtu,
        .ndo_start_xmit = batadv_interface_tx,
-       .ndo_validate_addr = eth_validate_addr
+       .ndo_validate_addr = eth_validate_addr,
+       .ndo_add_slave = batadv_softif_slave_add,
+       .ndo_del_slave = batadv_softif_slave_del,
 };
 
 /**