[B.A.T.M.A.N.] [PATCH] batman-adv: fix old master freeing operation

[B.A.T.M.A.N.] [PATCH] batman-adv: fix old master freeing operation

[Antonio Quartulli]

When a new hard_iface has a master already, ndo_del_slave
has to be used in order to let the old master perform its
cleaning up routing correctly. Unregistering the master
iface only could lead to a inconsistent state in the old
master knowledge.

Introduced by 5e57e3bff429cd403f0e30af69cf87a2cd55598f
("batman-adv: free an hard-interface before adding it").

Reported-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
---
 hard-interface.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/hard-interface.c b/hard-interface.c
index fd99e42..f446e69 100644
--- a/hard-interface.c
+++ b/hard-interface.c
@@ -346,8 +346,15 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 	 * in that case unlink it first
 	 */
 	master = netdev_master_upper_dev_get(hard_iface->net_dev);
-	if (master)
-		netdev_upper_dev_unlink(hard_iface->net_dev, master);
+	if (master && master->netdev_ops->ndo_del_slave) {
+		ret = master->netdev_ops->ndo_del_slave(master,
+							hard_iface->net_dev);
+		if (ret < 0)
+			goto err_dev;
+	} else if (master) {
+		ret = -EINVAL;
+		goto err_dev;
+	}
 
 	hard_iface->soft_iface = soft_iface;
 	bat_priv = netdev_priv(hard_iface->soft_iface);
-- 
1.8.1.5

Re: [B.A.T.M.A.N.] [PATCH] batman-adv: fix old master freeing operation

[Marek Lindner]

On Monday, March 04, 2013 01:34:36 Antonio Quartulli wrote:
> +       if (master && master->netdev_ops->ndo_del_slave) {
> +               ret = master->netdev_ops->ndo_del_slave(master,
> +                                                       hard_iface->net_dev
> );

Aren't we going to have compat trouble with this one ?

Cheers,
Marek

Re: [B.A.T.M.A.N.] [PATCH] batman-adv: fix old master freeing operation

[Antonio Quartulli]

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On Mon, Mar 04, 2013 at 01:47:05 +0800, Marek Lindner wrote:
> On Monday, March 04, 2013 01:34:36 Antonio Quartulli wrote:
> > +       if (master && master->netdev_ops->ndo_del_slave) {
> > +               ret = master->netdev_ops->ndo_del_slave(master,
> > +                                                       hard_iface->net_dev
> > );
> 
> Aren't we going to have compat trouble with this one ?

Yes. Kernels before 2.6.39 do not have the ndo_del_slave() op.
We need a way to make this code compatible..

Cheers,

-- 
Antonio Quartulli

..each of us alone is worth nothing..
Ernesto "Che" Guevara

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