• Haishuang Yan's avatar
    ipv4: Namespaceify tcp_fastopen_blackhole_timeout knob · 3733be14
    Haishuang Yan authored
    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: default avatarHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    3733be14
sysctl_net_ipv4.c 29.2 KB