From 2646c831c00c5d22aa72b79d24069c1b412cda7c Mon Sep 17 00:00:00 2001 From: Daniel Lee Date: Mon, 6 Apr 2015 14:37:27 -0700 Subject: tcp: RFC7413 option support for Fast Open client Fast Open has been using an experimental option with a magic number (RFC6994). This patch makes the client by default use the RFC7413 option (34) to get and send Fast Open cookies. This patch makes the client solicit cookies from a given server first with the RFC7413 option. If that fails to elicit a cookie, then it tries the RFC6994 experimental option. If that also fails, it uses the RFC7413 option on all subsequent connect attempts. If the server returns a Fast Open cookie then the client caches the form of the option that successfully elicited a cookie, and uses that form on later connects when it presents that cookie. The idea is to gradually obsolete the use of experimental options as the servers and clients upgrade, while keeping the interoperability meanwhile. Signed-off-by: Daniel Lee Signed-off-by: Yuchung Cheng Signed-off-by: Neal Cardwell Signed-off-by: David S. Miller --- include/linux/tcp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/tcp.h') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index a48d00318683..0caa3a2d4106 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -189,6 +189,7 @@ struct tcp_sock { u8 do_early_retrans:1,/* Enable RFC5827 early-retransmit */ syn_data:1, /* SYN includes data */ syn_fastopen:1, /* SYN includes Fast Open option */ + syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */ syn_data_acked:1,/* data in SYN is acked by SYN-ACK */ is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */ u32 tlp_high_seq; /* snd_nxt at the time of TLP retransmit. */ -- cgit v1.2.3