net-tcp: Fast Open client - cookie-less mode

In trusted networks, e.g., intranet, data-center, the client does not
need to use Fast Open cookie to mitigate DoS attacks. In cookie-less
mode, sendmsg() with MSG_FASTOPEN flag will send SYN-data regardless
of cookie availability.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 1edf96afab44..9febfb685c33 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -387,6 +387,7 @@ struct tcp_sock {
         u8      repair_queue;
         u8      do_early_retrans:1,/* Enable RFC5827 early-retransmit  */
                 early_retrans_delayed:1, /* Delayed ER timer installed */
+                syn_data:1,     /* SYN includes data */
                 syn_fastopen:1; /* SYN includes Fast Open option */
 
 /* RTT measurement */