ipvlan: assign unique dev-id for each slave device.

IPvlan setup uses one mac-address (of master). The IPv6 link-local
addresses are derived using the mac-address on the link. Lack of
dev-ids makes these link-local addresses same for all slaves including
that of master device. dev-ids are necessary to add differentiation
when L2 address is shared.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h
index dbfbb33..0a9068f 100644 (file)
--- a/drivers/net/ipvlan/ipvlan.h
+++ b/drivers/net/ipvlan/ipvlan.h
@@ -97,6 +97,7 @@ struct ipvl_port {
        struct work_struct      wq;
        struct sk_buff_head     backlog;
        int                     count;
+       struct ida              ida;
 };
 
 struct ipvl_skb_cb {

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 975f9dd..ce7ca6a 100644 (file)
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -119,6 +119,7 @@ static int ipvlan_port_create(struct net_device *dev)
 
        skb_queue_head_init(&port->backlog);
        INIT_WORK(&port->wq, ipvlan_process_multicast);
+       ida_init(&port->ida);
 
        err = netdev_rx_handler_register(dev, ipvlan_handle_frame, port);
        if (err)
@@ -150,6 +151,7 @@ static void ipvlan_port_destroy(struct net_device *dev)
                        dev_put(skb->dev);
                kfree_skb(skb);
        }
+       ida_destroy(&port->ida);
        kfree(port);
 }
 
@@ -533,6 +535,16 @@ static int ipvlan_link_new(struct net *src_net, struct net_device *dev,
        ipvlan_adjust_mtu(ipvlan, phy_dev);
        INIT_LIST_HEAD(&ipvlan->addrs);
 
+       /* Since L2 address is shared among all IPvlan slaves including
+        * master, use unique 16 bit dev-ids to diffentiate among them.
+        * Assign IDs between 0x1 and 0xFFFE (used by the master) to each
+        * slave link [see addrconf_ifid_eui48()].
+        */
+       err = ida_simple_get(&port->ida, 1, 0xFFFE, GFP_KERNEL);
+       if (err < 0)
+               goto destroy_ipvlan_port;
+       dev->dev_id = err;
+
        /* TODO Probably put random address here to be presented to the
         * world but keep using the physical-dev address for the outgoing
         * packets.
@@ -543,7 +555,7 @@ static int ipvlan_link_new(struct net *src_net, struct net_device *dev,
 
        err = register_netdevice(dev);
        if (err < 0)
-               goto destroy_ipvlan_port;
+               goto remove_ida;
 
        err = netdev_upper_dev_link(phy_dev, dev);
        if (err) {
@@ -562,6 +574,8 @@ unlink_netdev:
        netdev_upper_dev_unlink(phy_dev, dev);
 unregister_netdev:
        unregister_netdevice(dev);
+remove_ida:
+       ida_simple_remove(&port->ida, dev->dev_id);
 destroy_ipvlan_port:
        if (create)
                ipvlan_port_destroy(phy_dev);
@@ -579,6 +593,7 @@ static void ipvlan_link_delete(struct net_device *dev, struct list_head *head)
                kfree_rcu(addr, rcu);
        }
 
+       ida_simple_remove(&ipvlan->port->ida, dev->dev_id);
        list_del_rcu(&ipvlan->pnode);
        unregister_netdevice_queue(dev, head);
        netdev_upper_dev_unlink(ipvlan->phy_dev, dev);