On Fri, Jan 31, 2020 at 5:18 PM SeongJae Park <sj38.park@xxxxxxxxx> wrote: > > On Fri, 31 Jan 2020 17:11:35 -0500 Neal Cardwell <ncardwell@xxxxxxxxxx> wrote: > > > On Fri, Jan 31, 2020 at 1:12 PM Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote: > > > > > > > > > > > > On 1/31/20 7:10 AM, Neal Cardwell wrote: > > > > On Fri, Jan 31, 2020 at 7:25 AM <sjpark@xxxxxxxxxx> wrote: > > > >> > > > >> From: SeongJae Park <sjpark@xxxxxxxxx> > > > >> > > > >> When closing a connection, the two acks that required to change closing > > > >> socket's status to FIN_WAIT_2 and then TIME_WAIT could be processed in > > > >> reverse order. This is possible in RSS disabled environments such as a > > > >> connection inside a host. > [...] > > > > I looked into fixing this, but my quick reading of the Linux > > tcp_rcv_state_process() code is that it should behave correctly and > > that a connection in FIN_WAIT_1 that receives a FIN/ACK should move to > > TIME_WAIT. > > > > SeongJae, do you happen to have a tcpdump trace of the problematic > > sequence where the "process A" ends up in FIN_WAIT_2 when it should be > > in TIME_WAIT? > > Hi Neal, > > > Yes, I have. You can get it from the previous discussion for this patchset > (https://lore.kernel.org/bpf/20200129171403.3926-1-sjpark@xxxxxxxxxx/). As it > also has a reproducer program and how I got the tcpdump trace, I believe you > could get your own trace, too. If you have any question or need help, feel > free to let me know. :) Great. Thank you for the pointer. I had one quick question: in the message: https://lore.kernel.org/bpf/20200129171403.3926-1-sjpark@xxxxxxxxxx/ ... it showed a trace with the client sending a RST/ACK, but this email thread shows a FIN/ACK. I am curious about the motivation for the difference? Anyway, thanks for the report, and thanks to Eric for further clarifying! neal
