sk_receive_skb
return sk_receive_skb(sk_pppox(po), skb, 0);
return sk_receive_skb(sk, skb, 1);
return sk_receive_skb(sk, skb, 1);
return sk_receive_skb(sk, skb, 0);
return sk_receive_skb(sk, skb, 0);
return sk_receive_skb(sknode, skb, 1);
sk_receive_skb(sknode, clone, 0);
sk_receive_skb(sk, skb, 0);