[ICSK]: Introduce reqsk_queue_prune from code in tcp_synack_timer

With this we're very close to getting all of the current TCP
refactorings in my dccp-2.6 tree merged, next changeset will export
some functions needed by the current DCCP code and then dccp-2.6.git
will be born!

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index b7c7eec..447d287 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -97,6 +97,7 @@
  *
  * @rskq_accept_head - FIFO head of established children
  * @rskq_accept_tail - FIFO tail of established children
+ * @rskq_defer_accept - User waits for some data after accept()
  * @syn_wait_lock - serializer
  *
  * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
@@ -112,6 +113,8 @@
 	struct request_sock	*rskq_accept_head;
 	struct request_sock	*rskq_accept_tail;
 	rwlock_t		syn_wait_lock;
+	u8			rskq_defer_accept;
+	/* 3 bytes hole, try to pack */
 	struct listen_sock	*listen_opt;
 };
 
@@ -255,4 +258,8 @@
 	write_unlock(&queue->syn_wait_lock);
 }
 
+extern void reqsk_queue_prune(struct request_sock_queue *queue, struct sock *parent,
+			      const unsigned long interval, const unsigned long timeout,
+			      const unsigned long max_rto, int max_retries);
+
 #endif /* _REQUEST_SOCK_H */