[Bridge] [PATCH v9 net-next 01/12] bridge: Add vlan filtering infrastructure
Vlad Yasevich
vyasevic at redhat.com
Sat Feb 2 02:11:39 UTC 2013
On 02/01/2013 08:04 PM, Michał Mirosław wrote:
> 2013/2/1 Vlad Yasevich <vyasevic at redhat.com>:
>> Adds an optional infrustructure component to bridge that would allow
>> native vlan filtering in the bridge. Each bridge port (as well
>> as the bridge device) now get a VLAN bitmap. Each bit in the bitmap
>> is associated with a vlan id. This way if the bit corresponding to
>> the vid is set in the bitmap that the packet with vid is allowed to
>> enter and exit the port.
> [...]
> +struct net_port_vlans {
> + u16 port_idx;
> + void *parent;
> + struct rcu_head rcu;
> + unsigned long vlan_bitmap[BR_VLAN_BITMAP_LEN];
> +};
> [later, in br_vlan.c]
> +#define vlans_to_parent(type, pv) ((type *)(pv)->parent)
>
> A really don't like this pointer casting. It's easy to get it wrong
> (and you did in __vlan_del).
>
> 1. union { struct net_bridge *br; struct net_bridge_port *port; } parent;
>
> 2. inline net_port_vlans __rcu **br_vlan_info_parent_ptr(struct
> net_port_vlans *v)
> {
> return v->port_idx ? &v->parent.port->vlan_info : &v->parent.br->vlan_info;
> }
>
> (I'm not insisting on #2. Just think about it. ;)
I need the parent, not the vlan_info. Sometimes I need to get to the
device and I really don't want to then use container_of().
I suppose I could do the union, but that's really not much different
then the type casts. Just as easy to goof.
>
>> @@ -156,6 +166,7 @@ struct net_bridge_port
>> #ifdef CONFIG_NET_POLL_CONTROLLER
>> struct netpoll *np;
>> #endif
>> + struct net_port_vlans __rcu *vlan_info;
>> };
>
> Missing #ifdef CONFIG_BRIDGE_VLAN_FILTERING?
Yep. Its in net_bridge, but not here. Will fix.
>
>> +static int __vlan_del(struct net_port_vlans *v, u16 vid)
>> +{
>> + unsigned long first_bit;
>> + unsigned long last_bit;
>> +
>> + if (!test_bit(vid, v->vlan_bitmap))
>> + return -EINVAL;
>> +
>> + /* Check to see if any other vlans are in this table. If this
>> + * is the last vlan, delete the whole structure. If this is not the
>> + * last vlan, just clear the bit.
>> + */
>> + first_bit = find_first_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
>> + last_bit = find_last_bit(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
>> +
>> + if (v->port_idx && vid) {
>> + struct net_device *dev =
>> + vlans_to_parent(struct net_bridge, v)->dev;
>
> struct net_bridge_port (or union and v->parent.port)
Yep. Typo when doing conversions.
>
>> +
>> + if (dev->features & NETIF_F_HW_VLAN_FILTER)
>> + dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid);
>> + }
>> +
>> + clear_bit(vid, v->vlan_bitmap);
>> + if (first_bit == last_bit) {
>
> bitmap_empty() is faster than two times find_xxx_bit().
>
WTH? I did this change and now its gone... Time to see what else I
somehow lost...
>> + if (v->port_idx) {
>> + struct net_bridge_port *p =
>> + vlans_to_parent(struct net_bridge_port, v);
>> + rcu_assign_pointer(p->vlan_info, NULL);
>> + } else {
>> + struct net_bridge *br =
>> + vlans_to_parent(struct net_bridge, v);
>> + rcu_assign_pointer(br->vlan_info, NULL);
>> + }
>
> With inline function above:
>
> rcu_assign_pointer(*br_vlan_info_parent_ptr(v), NULL);
>
>> + kfree_rcu(v, rcu);
>> + }
>> + return 0;
>> +}
>> +
>> +static void __vlan_flush(struct net_port_vlans *v)
>> +{
>> + bitmap_zero(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
>> + if (v->port_idx) {
>> + struct net_bridge_port *p =
>> + vlans_to_parent(struct net_bridge_port, v);
>> + rcu_assign_pointer(p->vlan_info, NULL);
>> + } else {
>> + struct net_bridge *br =
>> + vlans_to_parent(struct net_bridge, v);
>> + rcu_assign_pointer(br->vlan_info, NULL);
>> + }
>
> Same here.
Thanks. I'll probably go with the union for direct reference.
-vlad
>
>> + kfree_rcu(v, rcu);
>> +}
>
> Best Regards,
> Michał Mirosław
>
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