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ipv4: Namespaceify tcp_fastopen_blackhole_timeout knob

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Different namespace application might require different time period in
second to disable Fastopen on active TCP sockets.

Tested:
Simulate following similar situation that the server's data gets dropped
after 3WHS.
C ---- syn-data ---> S
C <--- syn/ack ----- S
C ---- ack --------> S
S (accept & write)
C?  X <- data ------ S
	[retry and timeout]

And then print netstat of TCPFastOpenBlackhole, the counter increased as
expected when the firewall blackhole issue is detected and active TFO is
disabled.
# cat /proc/net/netstat | awk '{print $91}'
TCPFastOpenBlackhole
1

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Haishuang Yan
2017-09-27 11:35:43 +08:00
committed by David S. Miller
parent 4371384856
commit 3733be14a3
4 changed files with 27 additions and 28 deletions
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3
include/net/netns/ipv4.h
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@@ -133,6 +133,9 @@ struct netns_ipv4 {
int sysctl_tcp_fastopen;
struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;
spinlock_t tcp_fastopen_ctx_lock;
unsigned int sysctl_tcp_fastopen_blackhole_timeout;
atomic_t tfo_active_disable_times;
unsigned long tfo_active_disable_stamp;
#ifdef CONFIG_NET_L3_MASTER_DEV
int sysctl_udp_l3mdev_accept;