Subject: Re: [PATCH v13 10/16] Add a hook to intercept external buffers from NIC driver.

From: David Miller <[email-masked]>
Date: Tue, 19 Oct 2010 08:24:01 -0700 (PDT)

From: [email-masked]
Date: Fri, 15 Oct 2010 17:12:11 +0800

> @@ -2891,6 +2922,11 @@ static int __netif_receive_skb(struct sk_buff *skb)
>  ncls:
>  #endif
>  
> +	/* To intercept mediate passthru(zero-copy) packets here */
> +	skb = handle_mpassthru(skb, &pt_prev, &ret, orig_dev);
> +	if (!skb)
> +		goto out;
> +
>  	/* Handle special case of bridge or macvlan */
>  	rx_handler = rcu_dereference(skb->dev->rx_handler);
>  	if (rx_handler) {

If you consume the packet here, devices in passthru mode cannot
be use with bonding.

But there is nothing that prevents a bond being created with such
a device.

So we have to either prevent such configurations (bad) or make
it work somehow (good) :-)