On Mon, Apr 16, 2018 at 10:28:11PM -0700, Eric Dumazet wrote: > > I turned pr_debug on in tcp_in_window() for another try and it's a bit > > mangled because the information on multiple lines and the function is > > called in parallel but it looks like I do have some seq > maxend +1 > > > > Although it's weird, the maxend was set WAY earlier apparently? > > Apr 17 11:13:14 res=1 sender end=1913287798 maxend=1913316998 maxwin=29312 > > receiver end=505004284 maxend=505033596 maxwin=29200 > > then window decreased drastically e.g. previous ack just before refusal: > > Apr 17 11:13:53 seq=1913292311 ack=505007789+(0) sack=505007789+(0) win=284 > > end=1913292311 > > Apr 17 11:13:53 sender end=1913292311 maxend=1913331607 maxwin=284 scale=0 > > receiver end=505020155 maxend=505033596 maxwin=39296 scale=7 > > scale=0 is suspect. > > Really if conntrack does not see SYN SYNACK packets, it should not > make any window check, since windows can be scaled up to 14 :/
Or maybe set the scaling to - TCP_MAX_WSCALE (14) by default - 0 when SYN or SYNACK without window scale option is seen - value of window scale option when SYN or SYNACK with it is seen Michal Kubecek
