[TCP]: TCP_DEFER_ACCEPT updates - process as established
Change TCP_DEFER_ACCEPT implementation so that it transitions a
connection to ESTABLISHED after handshake is complete instead of
leaving it in SYN-RECV until some data arrvies. Place connection in
accept queue when first data packet arrives from slow path.
Benefits:
- established connection is now reset if it never makes it
to the accept queue
- diagnostic state of established matches with the packet traces
showing completed handshake
- TCP_DEFER_ACCEPT timeouts are expressed in seconds and can now be
enforced with reasonable accuracy instead of rounding up to next
exponential back-off of syn-ack retry.
Signed-off-by: Patrick McManus <mcmanus@ducksong.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 8a45be9..cc1a185 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -414,8 +414,7 @@
struct inet_connection_sock *icsk = inet_csk(parent);
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
struct listen_sock *lopt = queue->listen_opt;
- int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
- int thresh = max_retries;
+ int thresh = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
unsigned long now = jiffies;
struct request_sock **reqp, *req;
int i, budget;
@@ -451,9 +450,6 @@
}
}
- if (queue->rskq_defer_accept)
- max_retries = queue->rskq_defer_accept;
-
budget = 2 * (lopt->nr_table_entries / (timeout / interval));
i = lopt->clock_hand;
@@ -461,9 +457,8 @@
reqp=&lopt->syn_table[i];
while ((req = *reqp) != NULL) {
if (time_after_eq(now, req->expires)) {
- if ((req->retrans < (inet_rsk(req)->acked ? max_retries : thresh)) &&
- (inet_rsk(req)->acked ||
- !req->rsk_ops->rtx_syn_ack(parent, req))) {
+ if (req->retrans < thresh &&
+ !req->rsk_ops->rtx_syn_ack(parent, req)) {
unsigned long timeo;
if (req->retrans++ == 0)