On Sat, Aug 13, 2016 at 4:05 PM, Piotr Jurkiewicz <piotr.jerzy.jurkiew...@gmail.com> wrote: > 1. Handling of TFO_SERVER_COOKIE_NOT_CHKED flag was removed back in 2014, > but this flag is still mentioned in the documentation: > > Documentation/networking/ip-sysctl.txt: > 0x100: Accept SYN data w/o validating the cookie. > > 2. There is no explanation how TFO_SERVER_WO_SOCKOPT1 and > TFO_SERVER_WO_SOCKOPT2 differ, the docs only say: > > Documentation/networking/ip-sysctl.txt: > 0x400/0x800: Enable Fast Open on all listeners regardless of the > TCP_FASTOPEN socket option. The two different flags designate two > different ways of setting max_qlen without the TCP_FASTOPEN > socket > option. > > 3. When TFO_SERVER_WO_SOCKOPT2 flag is set, the fastopenq.max_qlen is set to > the value of sysctl bitmap containing flags (sysctl_tcp_fastopen), what is > (at least for me) completely irrational and I believe is a bug: > > net/ipv4/af_inet.c: > 225 else if ((sysctl_tcp_fastopen & > 226 TFO_SERVER_WO_SOCKOPT2) != 0) > 227 fastopen_queue_tune(sk, > 228 ((uint)sysctl_tcp_fastopen) >> 16); Thanks for pointing these issues out. The document indeed needs work.
TFO_SERVERS_WO_SOCKEOPT2 was used for debugging purposes that we forget to clean up before upstream. Here is my plan: 1) send a patch to remove this opaque/buggy internal debugging option 2) update the ip-sysctl, perhaps update tcp option man pages How does that sound?
