tcp: enable sockets to use MSG_FASTOPEN by default (0d41cca4) · Commits · 戴 / test

Applications have started to use Fast Open (e.g., Chrome browser has such an optional flag) and the feature has gone through several generations of kernels since 3.7 with many real network tests. It's time to enable this flag by default for applications to test more conveniently and extensively. Signed-off-by:

Yuchung Cheng <ycheng@google.com> Signed-off-by:

Neal Cardwell <ncardwell@google.com> Acked-by:

Eric Dumazet <edumazet@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

Documentation/networking/ip-sysctl.txt

+2 −2

Original line number	Diff line number	Diff line
		@@ -451,7 +451,7 @@ tcp_fastopen - INTEGER
		connect() to perform a TCP handshake automatically.

		The values (bitmap) are
		1: Enables sending data in the opening SYN on the client.
		1: Enables sending data in the opening SYN on the client w/ MSG_FASTOPEN.
		2: Enables TCP Fast Open on the server side, i.e., allowing data in
		a SYN packet to be accepted and passed to the application before
		3-way hand shake finishes.
		@@ -464,7 +464,7 @@ tcp_fastopen - INTEGER
		different ways of setting max_qlen without the TCP_FASTOPEN socket
		option.

		Default: 0
		Default: 1

		Note that the client & server side Fast Open flags (1 and 2
		respectively) must be also enabled before the rest of flags can take

net/ipv4/tcp_fastopen.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -8,7 +8,7 @@
		#include <net/inetpeer.h>
		#include <net/tcp.h>

		int sysctl_tcp_fastopen __read_mostly;
		int sysctl_tcp_fastopen __read_mostly = TFO_CLIENT_ENABLE;

		struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;

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