[Devel] [PATCH 3/5] veth: filter packages accoding with mac addresses

[Andrew Vagin]

On Thu, Jun 04, 2015 at 02:29:50PM +0300, Kirill Tkhai wrote:
> Hi, Andrew,
> 
> please, see the comment below
> 
> В Чт, 28/05/2015 в 15:06 +0400, Andrew Vagin пишет:
> > Only if the NETIF_F_VENET flag is set.
> > 
> > A containers doesn't get and send packages with an mac address
> > which doesn't belong to it.
> > 
> > Signed-off-by: Andrew Vagin <avagin at openvz.org>
> > ---
> >  drivers/net/veth.c |   30 ++++++++++++++++++++++++++++++
> >  1 files changed, 30 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> > index 7f64043..7f98a05 100644
> > --- a/drivers/net/veth.c
> > +++ b/drivers/net/veth.c
> > @@ -19,6 +19,7 @@
> >  #include <net/xfrm.h>
> >  #include <linux/veth.h>
> >  #include <linux/module.h>
> > +#include "../../net/bridge/br_private.h"
> >  
> >  #define DRV_NAME	"veth"
> >  #define DRV_VERSION	"1.0"
> > @@ -105,6 +106,31 @@ static const struct ethtool_ops veth_ethtool_ops = {
> >  	.get_ethtool_stats	= veth_get_ethtool_stats,
> >  };
> >  
> > +static int vzethdev_filter(struct sk_buff *skb, struct net_device *dev, struct net_device *rcv)
> > +{
> > +	/* Filtering */
> > +	if (ve_is_super(dev_net(dev)->owner_ve) &&
> > +	    dev->features & NETIF_F_FIXED_ADDR) {
> > +		/* from VE0 to VEX */
> > +		if (ve_is_super(dev_net(rcv)->owner_ve))
> > +			return 1;
> > +		if (is_multicast_ether_addr(
> > +					((struct ethhdr *)skb->data)->h_dest))
> > +			return 1;
> > +		if (!br_port_get_rcu(rcv) &&
> 
> won't we receive RCU lockdep warnings here, because of rcu_read_lock() is not held?

veth_xmit() is called from veth_xmit where we take rcu_read_lock()

> 
> > +			compare_ether_addr(((struct ethhdr *)skb->data)->h_dest, rcv->dev_addr))
> > +				return 0;
> > +	} else if (!ve_is_super(dev_net(dev)->owner_ve) &&
> > +		   dev->features & NETIF_F_FIXED_ADDR) {
> > +		/* from VEX to VE0 */
> > +		if (!br_port_get_rcu(dev) &&
> > +			compare_ether_addr(((struct ethhdr *)skb->data)->h_source, dev->dev_addr))
> > +				return 0;
> > +	}
> > +
> > +	return 1;
> > +}
> > +
> >  static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
> >  {
> >  	struct veth_priv *priv = netdev_priv(dev);
> > @@ -124,6 +150,10 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
> >  	    rcv->features & NETIF_F_RXCSUM)
> >  		skb->ip_summed = CHECKSUM_UNNECESSARY;
> >  
> > +
> > +	if (dev->features & NETIF_F_VENET && !vzethdev_filter(skb, dev, rcv))
> > +		goto drop;
> > +
> >  	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
> >  		struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
> >  
> 
>