Subject: Re: [RFC PATCH bridge 1/5] bridge: Add vlan check to forwarding path

From: "Michael S. Tsirkin" <[email-masked]>
Date: Thu, 30 Aug 2012 15:19:24 +0300

On Thu, Aug 23, 2012 at 03:29:51PM -0400, Vlad Yasevich wrote:
> When forwarding packets make sure vlan matches any configured vlan for
> the port.
> 
> Signed-off-by: Vlad Yasevich <[email-masked]>
> ---
>  net/bridge/br_forward.c |   17 ++++++++++++++++-
>  net/bridge/br_input.c   |    8 ++++++++
>  net/bridge/br_private.h |    2 ++
>  3 files changed, 26 insertions(+), 1 deletions(-)
> 
> diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
> index e9466d4..ab81954 100644
> --- a/net/bridge/br_forward.c
> +++ b/net/bridge/br_forward.c
> @@ -26,11 +26,26 @@ static int deliver_clone(const struct net_bridge_port *prev,
>  			 void (*__packet_hook)(const struct net_bridge_port *p,
>  					       struct sk_buff *skb));
>  
> -/* Don't forward packets to originating port or forwarding diasabled */
> +/* check to see that the vlan is allowed to be forwarded on this interface */
> +static inline int vlan_match(const struct net_bridge_port *p,
> +			     const struct sk_buff *skb)
> +{
> +	unsigned long *vlan_map = rcu_dereference(p->vlan_map);
> +	unsigned short vid = vlan_tx_tag_get(skb) & VLAN_VID_MASK;
> +
> +	/* The map keeps the vlans off by 1 so adjust for that */
> +	return (vlan_map && vlan_tx_tag_present(skb) &&
> +		test_bit(vid+1, vlan_map));

It looks better if you put spaces around +,* etc:
vid + 1 This applies to all patches and many places so I am not
noting it everywhere - could you fnd such instances and fix up?

Also, this off by 1 map logic is all over this patch,
one hopes we did not forget is somewhere.
Would be better to have a wrapper.

Also do not put return value in () please - it gets us nothing
at all. Again applies everywhere.

> +}
> +
> +/* Don't forward packets to originating port or forwarding diasabled.
> + */
>  static inline int should_deliver(const struct net_bridge_port *p,
>  				 const struct sk_buff *skb)
>  {
> +

extra empty line - no needed here.

>  	return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
> +		vlan_match(p, skb) &&
>  		p->state == BR_STATE_FORWARDING);
>  }
>  
> diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
> index 76f15fd..b7ca3b3 100644
> --- a/net/bridge/br_input.c
> +++ b/net/bridge/br_input.c
> @@ -53,10 +53,18 @@ int br_handle_frame_finish(struct sk_buff *skb)
>  	struct net_bridge_fdb_entry *dst;
>  	struct net_bridge_mdb_entry *mdst;
>  	struct sk_buff *skb2;
> +	unsigned long *vlan_map;
>  
>  	if (!p || p->state == BR_STATE_DISABLED)
>  		goto drop;
>  
> +	/* If VLAN filter is configured on the port, make sure we accept
> +	 * only traffic matching the VLAN filter.
> +	 */
> +	vlan_map = rcu_dereference(p->vlan_map);
> +	if (vlan_map && !test_bit((skb->vlan_tci & VLAN_VID_MASK), vlan_map))

() not needed here around parameters.

> +		goto drop;
> +
>  	/* insert into forwarding database after filtering to avoid spoofing */
>  	br = p->br;
>  	br_fdb_update(br, p, eth_hdr(skb)->h_source);
> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> index a768b24..8da90e8 100644
> --- a/net/bridge/br_private.h
> +++ b/net/bridge/br_private.h
> @@ -152,6 +152,8 @@ struct net_bridge_port
>  #ifdef CONFIG_NET_POLL_CONTROLLER
>  	struct netpoll			*np;
>  #endif
> +	unsigned long __rcu		*vlan_map;
> +

Empty line not needed.

>  };
>  
>  #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT)
> -- 
> 1.7.7.6
> 
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