netdev - Re: [PATCH v2 net-next 5/8] bridge: Add addresses from static fdbs to non-promisc ports

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Date:	Thu, 15 May 2014 20:35:04 +0300
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Vlad Yasevich <vyasevic@...hat.com>
Cc:	netdev@...r.kernel.org, bridge@...ts.linux-foundation.org,
	shemminger@...tta.com, john.r.fastabend@...el.com, jhs@...atatu.com
Subject: Re: [PATCH v2 net-next 5/8] bridge: Add addresses from static fdbs
 to non-promisc ports

On Thu, May 15, 2014 at 12:56:53PM -0400, Vlad Yasevich wrote:
> When a static fdb entry is created, add the mac address
> from this fdb entry to any ports that are currently running
> in non-promiscuous mode.  These ports need this data so that
> they can receive traffic destined to these addresses.
> By default ports start in promiscuous mode, so this feature
> is disabled.
> 
> Signed-off-by: Vlad Yasevich <vyasevic@...hat.com>

Acked-by: Michael S. Tsirkin <mst@...hat.com>

whitespace nit below

> ---
>  net/bridge/br_fdb.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 70 insertions(+), 6 deletions(-)
> 
> diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
> index fe124e5..834ca8c 100644
> --- a/net/bridge/br_fdb.c
> +++ b/net/bridge/br_fdb.c
> @@ -85,8 +85,58 @@ static void fdb_rcu_free(struct rcu_head *head)
>  	kmem_cache_free(br_fdb_cache, ent);
>  }
>  
> +/* When a static FDB entry is added, the mac address from the entry is
> + * added to the bridge private HW address list and all required ports
> + * are then updated with the new information.
> + * Called under RTNL.
> + */
> +static void fdb_add_hw(struct net_bridge *br, const unsigned char *addr)
> +{
> +	int err;
> +	struct net_bridge_port *p, *tmp;
> +
> +	ASSERT_RTNL();
> +
> +	list_for_each_entry(p, &br->port_list, list) {
> +		if (!br_promisc_port(p)) {
> +			err = dev_uc_add(p->dev, addr);
> +			if (err)
> +				goto undo;
> +		}
> +	}
> +
> +	return;
> +undo:
> +	list_for_each_entry(tmp, &br->port_list, list) {
> +		if (tmp == p)
> +			break;
> +		if (!br_promisc_port(tmp))
> +			dev_uc_del(tmp->dev, addr);
> +	}
> +}
> +
> +/* When a static FDB entry is deleted, the HW address from that entry is
> + * also removed from the bridge private HW address list and updates all
> + * the ports with needed information.
> + * Called under RTNL.
> + */
> +static void fdb_del_hw(struct net_bridge *br, const unsigned char *addr)
> +{
> +	struct net_bridge_port *p;
> +
> +	ASSERT_RTNL();
> +
> +	list_for_each_entry(p, &br->port_list, list) {
> +		if (!br_promisc_port(p))
> +			dev_uc_del(p->dev, addr);
> +	}
> +}
> +
>  static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
>  {
> +	if (f->is_static)
> +		fdb_del_hw(br, f->addr.addr);
> +
>  	hlist_del_rcu(&f->hlist);
>  	fdb_notify(br, f, RTM_DELNEIGH);
>  	call_rcu(&f->rcu, fdb_rcu_free);
> @@ -466,6 +516,7 @@ static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
>  		return -ENOMEM;
>  
>  	fdb->is_local = fdb->is_static = 1;
> +	fdb_add_hw(br, addr);
>  	fdb_notify(br, fdb, RTM_NEWNEIGH);
>  	return 0;
>  }
> @@ -678,16 +729,29 @@ static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
>  	}
>  
>  	if (fdb_to_nud(fdb) != state) {
> -		if (state & NUD_PERMANENT)
> -			fdb->is_local = fdb->is_static = 1;
> -		else if (state & NUD_NOARP) {
> +		if (state & NUD_PERMANENT) {
> +			fdb->is_local = 1;
> +			if (!fdb->is_static) {
> +				fdb->is_static = 1;
> +				fdb_add_hw(br, addr);
> +			}
> +		} else if (state & NUD_NOARP) {
> +			fdb->is_local = 0;
> +			if (!fdb->is_static) {
> +				fdb->is_static = 1;
> +				fdb_add_hw(br, addr);
> +			}
> +		} else {
>  			fdb->is_local = 0;
> -			fdb->is_static = 1;
> -		} else
> -			fdb->is_local = fdb->is_static = 0;
> +			if (fdb->is_static) {
> +				fdb->is_static = 0;
> +				fdb_del_hw(br, addr);
> +			}
> +		}
>  
>  		modified = true;
>  	}
> +

Is this eally necessary?

>  	fdb->added_by_user = 1;
>  
>  	fdb->used = jiffies;
> -- 
> 1.9.0
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