On Thursday, March 24, 2011 3:51:14 pm John Baldwin wrote: > On Thursday, March 24, 2011 3:21:24 pm Doug Barton wrote: > > http://blogmal.42.org/tidbits/tcp-bug.story > > > > $someone really needs to take a look at this. :) > > This is the same bug I reported back in February in this e-mail: > > http://lists.freebsd.org/pipermail/freebsd-net/2011-February/027892.html > > His patch may be the more correct fix though. I have two other TCP bugs also > awaiting review that I posted on the same day.
Actually, I retract that a bit. I saw the problem with window updates for an established connection and his proposed change doesn't cover that. Also, I think the root problem is that tp->rcv_wnd is calculated incorrectly in this case. However, I'd be curious to see if the patch from my original e-mail fixes the issue first. Otherwise, something like this may apply instead: Index: tcp_input.c =================================================================== --- tcp_input.c (revision 219911) +++ tcp_input.c (working copy) @@ -1694,7 +1694,10 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, win = sbspace(&so->so_rcv); if (win < 0) win = 0; - tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt)); + if (SEQ_GEQ(tp->rcv_adv, tp->rcv_nxt)) + tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt)); + else + tp->rcv_wnd = win; /* Reset receive buffer auto scaling when not in bulk receive mode. */ tp->rfbuf_ts = 0; I think that will fix tp->rcv_wnd to be correct in this case thus fixing further uses of it. -- John Baldwin _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"