[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>

1 files changed, 28 insertions, 18 deletions

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index c03930c48f42..b614ad4d30c9 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -424,16 +424,12 @@ out_unlock:
         sock_put(sk);
 }
 
-/*
- *      Timer for listening sockets
- */
-
-static void tcp_synack_timer(struct sock *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 tcp_sock *tp = tcp_sk(sk);
-        struct inet_connection_sock *icsk = inet_csk(sk);
-        struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
-        int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_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;
@@ -470,10 +466,10 @@ static void tcp_synack_timer(struct sock *sk)
                 }
         }
 
-        if (tp->defer_accept)
-                max_retries = tp->defer_accept;
+        if (queue->rskq_defer_accept)
+                max_retries = queue->rskq_defer_accept;
 
-        budget = 2*(TCP_SYNQ_HSIZE/(TCP_TIMEOUT_INIT/TCP_SYNQ_INTERVAL));
+        budget = 2 * (lopt->nr_table_entries / (timeout / interval));
         i = lopt->clock_hand;
 
         do {
@@ -482,20 +478,19 @@ static void tcp_synack_timer(struct sock *sk)
                         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(sk, req, NULL)) {
+                                    && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
                                         unsigned long timeo;
 
                                         if (req->retrans++ == 0)
                                                 lopt->qlen_young--;
-                                        timeo = min((TCP_TIMEOUT_INIT << req->retrans),
-                                                    TCP_RTO_MAX);
+                                        timeo = min((timeout << req->retrans), max_rto);
                                         req->expires = now + timeo;
                                         reqp = &req->dl_next;
                                         continue;
                                 }
 
                                 /* Drop this request */
-                                inet_csk_reqsk_queue_unlink(sk, req, reqp);
+                                inet_csk_reqsk_queue_unlink(parent, req, reqp);
                                 reqsk_queue_removed(&icsk->icsk_accept_queue, req);
                                 reqsk_free(req);
                                 continue;
@@ -503,14 +498,29 @@ static void tcp_synack_timer(struct sock *sk)
                         reqp = &req->dl_next;
                 }
 
-                i = (i+1)&(TCP_SYNQ_HSIZE-1);
+                i = (i + 1) & (lopt->nr_table_entries - 1);
 
         } while (--budget > 0);
 
         lopt->clock_hand = i;
 
         if (lopt->qlen)
-                inet_csk_reset_keepalive_timer(sk, TCP_SYNQ_INTERVAL);
+                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);
 }
 
 void tcp_set_keepalive(struct sock *sk, int val)