* Check permissions on incoming network packets. This hook is distinct
* from Netfilter's IP input hooks since it is the first time that the
* incoming sk_buff @skb has been associated with a particular socket, @sk.
* Check permissions on incoming network packets. This hook is distinct
* from Netfilter's IP input hooks since it is the first time that the
* incoming sk_buff @skb has been associated with a particular socket, @sk.