[ICSK]: Move generalised functions from tcp to inet_connection_sock

This also improves reqsk_queue_prune and renames it to
inet_csk_reqsk_queue_prune, as it deals with both inet_connection_sock
and inet_request_sock objects, not just with request_sock ones thus
belonging to inet_request_sock.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 91 deletions

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index b614ad4d30c9..72cec6981830 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -424,103 +424,14 @@ out_unlock:
 	sock_put(sk);
 }
 
-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)
-{
-	struct inet_connection_sock *icsk = inet_csk(parent);
-	struct listen_sock *lopt = queue->listen_opt;
-	int thresh = max_retries;
-	unsigned long now = jiffies;
-	struct request_sock **reqp, *req;
-	int i, budget;
-
-	if (lopt == NULL || lopt->qlen == 0)
-		return;
-
-	/* Normally all the openreqs are young and become mature
-	 * (i.e. converted to established socket) for first timeout.
-	 * If synack was not acknowledged for 3 seconds, it means
-	 * one of the following things: synack was lost, ack was lost,
-	 * rtt is high or nobody planned to ack (i.e. synflood).
-	 * When server is a bit loaded, queue is populated with old
-	 * open requests, reducing effective size of queue.
-	 * When server is well loaded, queue size reduces to zero
-	 * after several minutes of work. It is not synflood,
-	 * it is normal operation. The solution is pruning
-	 * too old entries overriding normal timeout, when
-	 * situation becomes dangerous.
-	 *
-	 * Essentially, we reserve half of room for young
-	 * embrions; and abort old ones without pity, if old
-	 * ones are about to clog our table.
-	 */
-	if (lopt->qlen>>(lopt->max_qlen_log-1)) {
-		int young = (lopt->qlen_young<<1);
-
-		while (thresh > 2) {
-			if (lopt->qlen < young)
-				break;
-			thresh--;
-			young <<= 1;
-		}
-	}
-
-	if (queue->rskq_defer_accept)
-		max_retries = queue->rskq_defer_accept;
-
-	budget = 2 * (lopt->nr_table_entries / (timeout / interval));
-	i = lopt->clock_hand;
-
-	do {
-		reqp=&lopt->syn_table[i];
-		while ((req = *reqp) != NULL) {
-			if (time_after_eq(now, req->expires)) {
-				if ((req->retrans < thresh ||
-				     (inet_rsk(req)->acked && req->retrans < max_retries))
-				    && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
-					unsigned long timeo;
-
-					if (req->retrans++ == 0)
-						lopt->qlen_young--;
-					timeo = min((timeout << req->retrans), max_rto);
-					req->expires = now + timeo;
-					reqp = &req->dl_next;
-					continue;
-				}
-
-				/* Drop this request */
-				inet_csk_reqsk_queue_unlink(parent, req, reqp);
-				reqsk_queue_removed(&icsk->icsk_accept_queue, req);
-				reqsk_free(req);
-				continue;
-			}
-			reqp = &req->dl_next;
-		}
-
-		i = (i + 1) & (lopt->nr_table_entries - 1);
-
-	} while (--budget > 0);
-
-	lopt->clock_hand = i;
-
-	if (lopt->qlen)
-		inet_csk_reset_keepalive_timer(parent, interval);
-}
-
-EXPORT_SYMBOL_GPL(reqsk_queue_prune);
-
 /*
  *	Timer for listening sockets
  */
 
 static void tcp_synack_timer(struct sock *sk)
 {
-	struct inet_connection_sock *icsk = inet_csk(sk);
-	const int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
-
-	reqsk_queue_prune(&icsk->icsk_accept_queue, sk, TCP_SYNQ_INTERVAL,
-			  TCP_TIMEOUT_INIT, TCP_RTO_MAX, max_retries);
+	inet_csk_reqsk_queue_prune(sk, TCP_SYNQ_INTERVAL,
+				   TCP_TIMEOUT_INIT, TCP_RTO_MAX);
 }
 
 void tcp_set_keepalive(struct sock *sk, int val)