[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/tcp.c b/net/ipv4/tcp.c
index 071e83a..e0fbc25 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2105,15 +2105,12 @@
break;
case TCP_DEFER_ACCEPT:
- icsk->icsk_accept_queue.rskq_defer_accept = 0;
- if (val > 0) {
- /* Translate value in seconds to number of
- * retransmits */
- while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
- val > ((TCP_TIMEOUT_INIT / HZ) <<
- icsk->icsk_accept_queue.rskq_defer_accept))
- icsk->icsk_accept_queue.rskq_defer_accept++;
- icsk->icsk_accept_queue.rskq_defer_accept++;
+ if (val < 0) {
+ err = -EINVAL;
+ } else {
+ if (val > MAX_TCP_ACCEPT_DEFERRED)
+ val = MAX_TCP_ACCEPT_DEFERRED;
+ icsk->icsk_accept_queue.rskq_defer_accept = val;
}
break;
@@ -2295,8 +2292,7 @@
val = (val ? : sysctl_tcp_fin_timeout) / HZ;
break;
case TCP_DEFER_ACCEPT:
- val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
- ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
+ val = icsk->icsk_accept_queue.rskq_defer_accept;
break;
case TCP_WINDOW_CLAMP:
val = tp->window_clamp;