sk_nulls_node
return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
return (!is_a_nulls(sk->sk_nulls_node.next)) ?
hlist_nulls_entry(sk->sk_nulls_node.next,
struct sock, sk_nulls_node) :
hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
hlist_nulls_replace_init_rcu(&old->sk_nulls_node,
&new->sk_nulls_node);
hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
hlist_nulls_replace_init_rcu(&sk->sk_nulls_node, &tw->tw_node);