[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/include/linux/tcp.h b/include/linux/tcp.h
index 08027f1..d96d9b1 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -239,6 +239,11 @@
return (struct tcp_request_sock *)req;
}
+struct tcp_deferred_accept_info {
+ struct sock *listen_sk;
+ struct request_sock *request;
+};
+
struct tcp_sock {
/* inet_connection_sock has to be the first member of tcp_sock */
struct inet_connection_sock inet_conn;
@@ -374,6 +379,8 @@
unsigned int keepalive_intvl; /* time interval between keep alive probes */
int linger2;
+ struct tcp_deferred_accept_info defer_tcp_accept;
+
unsigned long last_synq_overflow;
u32 tso_deferred;
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index 040780a..0369f98 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -115,8 +115,8 @@
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 */
+ u16 rskq_defer_accept;
+ /* 2 bytes hole, try to pack */
struct listen_sock *listen_opt;
};
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 847e163..67cc395 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -139,6 +139,7 @@
#define MAX_TCP_KEEPINTVL 32767
#define MAX_TCP_KEEPCNT 127
#define MAX_TCP_SYNCNT 127
+#define MAX_TCP_ACCEPT_DEFERRED 65535
#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */