+ * sk_filter - run a packet through a socket filter
+ * @sk: sock associated with &sk_buff
+ * @skb: buffer to filter
+ * @needlock: set to 1 if the sock is not locked by caller.
+ *
+ * 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.
+ *
+ */
+int sk_filter(struct sock *sk, struct sk_buff *skb)
+{
+ int err;
+ struct sk_filter *filter;
+
+ err = security_sock_rcv_skb(sk, skb);
+ if (err)
+ return err;
+
+ rcu_read_lock_bh();
+ filter = rcu_dereference(sk->sk_filter);
+ if (filter) {
+ unsigned int pkt_len = sk_run_filter(skb, filter->insns,
+ filter->len);
+ err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;
+ }
+ rcu_read_unlock_bh();
+
+ return err;
+}
+EXPORT_SYMBOL(sk_filter);
+
+/**