vxlan: leave multicast group when vxlan device down

vxlan_group_used only allows device to leave multicast group
when the remote_ip of this vxlan device is difference from
other vxlan devices' remote_ip. this will cause device not
leave multicast group untile the vn_sock of this vxlan deivce
being released.

The check in vxlan_group_used is not quite precise. since even
the remote_ip is same, but these vxlan devices may use different
lower devices, and they may use different vn_socks.

Only when some vxlan devices use the same vn_sock,same lower
device and same remote_ip, the mc_list of the vn_sock should
not be changed.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 43dc9ee4758f1d14791ed5cba24f2b58d15db971..58f6a0c02b173f7ad2d753630e1fc69f778d2789 100644 (file)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -916,17 +916,32 @@ static bool vxlan_snoop(struct net_device *dev,
 }
 
 /* See if multicast group is already in use by other ID */
-static bool vxlan_group_used(struct vxlan_net *vn, union vxlan_addr *remote_ip)
+static bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev)
 {
        struct vxlan_dev *vxlan;
 
+       /* The vxlan_sock is only used by dev, leaving group has
+        * no effect on other vxlan devices.
+        */
+       if (atomic_read(&dev->vn_sock->refcnt) == 1)
+               return false;
+
        list_for_each_entry(vxlan, &vn->vxlan_list, next) {
-               if (!netif_running(vxlan->dev))
+               if (!netif_running(vxlan->dev) || vxlan == dev)
                        continue;
 
-               if (vxlan_addr_equal(&vxlan->default_dst.remote_ip,
-                                    remote_ip))
-                       return true;
+               if (vxlan->vn_sock != dev->vn_sock)
+                       continue;
+
+               if (!vxlan_addr_equal(&vxlan->default_dst.remote_ip,
+                                     &dev->default_dst.remote_ip))
+                       continue;
+
+               if (vxlan->default_dst.remote_ifindex !=
+                   dev->default_dst.remote_ifindex)
+                       continue;
+
+               return true;
        }
 
        return false;
@@ -1981,7 +1996,7 @@ static int vxlan_stop(struct net_device *dev)
        struct vxlan_sock *vs = vxlan->vn_sock;
 
        if (vs && vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
-           ! vxlan_group_used(vn, &vxlan->default_dst.remote_ip)) {
+           !vxlan_group_used(vn, vxlan)) {
                vxlan_sock_hold(vs);
                dev_hold(dev);
                queue_work(vxlan_wq, &vxlan->igmp_leave);