centos man page for sk_filter

SK_FILTER(9)							 Linux Networking						      SK_FILTER(9)

NAME
       sk_filter - run a packet through a socket filter

SYNOPSIS
       int sk_filter(struct sock * sk, struct sk_buff * skb);

ARGUMENTS
       sk
	   sock associated with sk_buff

       skb
	   buffer to filter

DESCRIPTION
       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.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							      SK_FILTER(9)