[PATCH/RFC] disallow vlan devices on top of a logical bridge device

[Bart De Schuymer <bdschuym@xxxxxxxxxx>]

Hi all,

The patch below disables making vlan devices on top of bridge
devices, f.e. br0.12 would be impossible.
I'm no vlan expert, but I don't see the use for this and allowing it
will make the bridge-nf code hairy if we want to let {ip,arp}tables see
{IP,ARP} traffic that is embedded in a vlan header.
Also, situations like eth0.15 being a bridge port of br0.16 seem
unwanted (to me).
Dave, please apply, unless someone more knowledgeable (than me) about
this disagrees.

cheers,
Bart

--- linux-2.6.0-test4/net/bridge/br_if.c.old    2003-08-30 13:51:26.000000000 
+0200
+++ linux-2.6.0-test4/net/bridge/br_if.c        2003-08-30 14:38:58.000000000 
+0200
@@ -98,6 +98,8 @@ static struct net_bridge *new_nb(const c
        if (!dev)
                return NULL;
 
+       dev->features |= NETIF_F_VLAN_CHALLENGED;
+       
        br = dev->priv;
        br->dev = dev;