sk
skb
Run the filter code and then cut skb->data to correct size returned by sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller than pkt_len we keep whole skb->data. This is the socket level wrapper to sk_run_filter. It returns 0 if the packet should be accepted or -EPERM if the packet should be tossed.