On Sun, May 24, 2015 at 04:55:40AM +0000, Oliver Graff wrote: > Shawn Bohrer <shawn.bohrer <at> gmail.com> writes: > > > > > On Tue, May 13, 2014 at 04:36:41PM -0500, Shawn Bohrer wrote: > > > > If I did "break" something here it appears to be because with > > > ip_early_demux we only call ip_check_mc_rcu() once on the initial > > > packet, and subsequent packets destined for that socket simply need to > > > pass the __udp_is_mcast_sock() test. With ip_early_demux disaled we > > > call ip_check_mc_rcu() for every packet. > > > > So is the solution to effectively call ip_check_mc_rcu() inside > > udp_v4_early_demux()? > > > > -- > > Shawn > > > (See earlier parts of thread here: > http://netdev.vger.kernel.narkive.com/mwurLsMT/socket-receives-packet-to-multicast- > group-to-which-it-was-not-joined-since-kernel-3-13-10-1) > > Was a bug report filed for this / was this fixed? > I looked at the diffs from the referenced commit and the current version of > udp_v4_early_demux and the changes appear to be > minimal, > it doesn't look like ip_check_mc_rcu was added. Is that all that's needed?
Hi Oliver, I haven't tested but looking over the code I would say that this has not been fixed. Is this issue impacting you? I think calling ip_check_mc_rcu (you might need some of the code from ip_route_input_noref too) might "fix" the issue, though I have not tried. My concern is that early demux is a performance optimization and I don't know how much this would impact multicast receive performance. As Eric mentioned in the earlier email if you don't care about performance you can simply disable early demux: echo 0 >/proc/sys/net/ipv4/ip_early_demux -- Shawn -- 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
