On Fri, Jul 24, 2015 at 11:28:14AM -0700, Alex Wang wrote: > On Fri, Jul 24, 2015 at 10:22 AM, Ben Pfaff <b...@nicira.com> wrote: > > > On Fri, Jul 24, 2015 at 09:59:04AM -0700, Alex Wang wrote: > > > I think we should not do the same for get_in4(). If interface is not > > > assigned > > > with ipv4 address, ioctl function will return errno 99. Then user could > > > later > > > assign a valid ip. But caching error number makes ovs never check again. > > > (unless react to RTNLGRP_LINK notification and mark it as invalid) > > > > > > This also makes me wondering, if the same thing could happen to > > get_in6()? > > > How do we cope with ipv6 address change? > > > > I assumed we would get a notification when the status changes, which > > would allow us to mark it as invalid. If we don't get the right kind of > > notification to invalidate our IPv4/v6 address caches, then we either > > shouldn't cache them at all or subscribe to the right kind of > > notification. > > > > After checking the code, I think we may be fine, > > I remembered I asked this offline before: > > We already have the NETLINK_ROUTE nl_sock joining multicast group > RTNLGRP_LINK and resetting the cache flags correctly when there is an > event. However, I could not find any documentation at all regarding the > multicast groups... If RTNLGRP_LINK reports both ipv4/6 address change, > then we are fine. If not, we need to also join the proper multicast groups > (e.g. RTNLGRP_IPV6_IFADDR, RTNLGRP_IPV4_IFADDR) > > Do you know more about this?
I think we need to join another multicast group, because utilities/nlmon doesn't report it when I add or remove IP addresses to a netdev. It does report it when I take a device up or down though. That raises the question of whether we use IP addresses enough to bother caching them. But it looks like ofproto-dpif-xlate looks up IP address these days for native tunneling, so the answer is probably "yes". _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
