On Thu, 2015-05-21 at 12:41 -0700, Yuchung Cheng wrote: > It'd be nice to count SYN and SYNACKs for apps tracking the handshake stats. > For syn-cookies we can't do much. But for the rest we can account > req->num_retrans for SYN-ACKs sent, and perhaps track SYN received in > request sock?
Well, this is partly because we can not guarantee the behavior that I chose to explicitly state that we were not tracking SYNACK for passive sessions. Also TCP_DEFER_ACCEPT comes into play here... If we want to handle this in a deterministic way, we would have to add some bit to warn the application reading tcp_info that the session was initiated after a valid syncookie was received, and that initial value of tcp_info.tcpi_segs_{in|out} can be wrong. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html