| Message ID | 20140116191304.GC17529@order.stressinduktion.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 01/16/2014 02:13 PM, Hannes Frederic Sowa wrote: > In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for > dad-completed ipv6 addresses") I build the detection of the first > operational link-local address much to complex. Additionally this code > now has a race condition. > > Replace it with a much simpler variant, which just scans the address > list when duplicate address detection completes, to check if this is > the first valid link local address and send RS and MLD reports then. > > Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") > Reported-by: Jiri Pirko <jiri@resnulli.us> > Cc: Flavio Leitner <fbl@redhat.com> > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > --- > +/* ifp->idev must be at least read locked */ > +static bool ipv6_lonely_lladdr(struct inet6_ifaddr *ifp) > +{ > + struct inet6_ifaddr *ifpiter; > + struct inet6_dev *idev = ifp->idev; > + > + list_for_each_entry(ifpiter, &idev->addr_list, if_list) { > + if (ifp != ifpiter && ifpiter->scope == IFA_LINK && > + (ifpiter->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE| > + IFA_F_OPTIMISTIC|IFA_F_DADFAILED)) == > + IFA_F_PERMANENT) > + return false; > + } > + return true; > +} Just a nit, but the idev->addr_list is sorted by scope, so you could use list_for_each_entry_reverse(), and break out once the scope is > IFA_LINK to reduce the number of compares. -Brian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jan 16, 2014 at 03:15:31PM -0500, Brian Haley wrote: > On 01/16/2014 02:13 PM, Hannes Frederic Sowa wrote: > > In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for > > dad-completed ipv6 addresses") I build the detection of the first > > operational link-local address much to complex. Additionally this code > > now has a race condition. > > > > Replace it with a much simpler variant, which just scans the address > > list when duplicate address detection completes, to check if this is > > the first valid link local address and send RS and MLD reports then. > > > > Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") > > Reported-by: Jiri Pirko <jiri@resnulli.us> > > Cc: Flavio Leitner <fbl@redhat.com> > > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > > --- > > > +/* ifp->idev must be at least read locked */ > > +static bool ipv6_lonely_lladdr(struct inet6_ifaddr *ifp) > > +{ > > + struct inet6_ifaddr *ifpiter; > > + struct inet6_dev *idev = ifp->idev; > > + > > + list_for_each_entry(ifpiter, &idev->addr_list, if_list) { > > + if (ifp != ifpiter && ifpiter->scope == IFA_LINK && > > + (ifpiter->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE| > > + IFA_F_OPTIMISTIC|IFA_F_DADFAILED)) == > > + IFA_F_PERMANENT) > > + return false; > > + } > > + return true; > > +} > > Just a nit, but the idev->addr_list is sorted by scope, so you could use > list_for_each_entry_reverse(), and break out once the scope is > IFA_LINK to > reduce the number of compares. Very good idea, but I would leave this patch for net as-is. I'll send one for net-next which does this optimization for the other functions at the weekend (we can do the same optimization to ipv6_get_lladdr etc.). Thanks, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jan 16, 2014 at 08:13:04PM +0100, Hannes Frederic Sowa wrote: > In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for > dad-completed ipv6 addresses") I build the detection of the first > operational link-local address much to complex. Additionally this code > now has a race condition. > > Replace it with a much simpler variant, which just scans the address > list when duplicate address detection completes, to check if this is > the first valid link local address and send RS and MLD reports then. > > Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") > Reported-by: Jiri Pirko <jiri@resnulli.us> > Cc: Flavio Leitner <fbl@redhat.com> > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > --- Nice Acked-by: Flavio Leitner <fbl@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Thu, Jan 16, 2014 at 08:13:04PM CET, hannes@stressinduktion.org wrote: >In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for >dad-completed ipv6 addresses") I build the detection of the first >operational link-local address much to complex. Additionally this code >now has a race condition. > >Replace it with a much simpler variant, which just scans the address >list when duplicate address detection completes, to check if this is >the first valid link local address and send RS and MLD reports then. > >Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") >Reported-by: Jiri Pirko <jiri@resnulli.us> >Cc: Flavio Leitner <fbl@redhat.com> >Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Jiri Pirko <jiri@resnulli.us> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Hannes Frederic Sowa <hannes@stressinduktion.org> Date: Thu, 16 Jan 2014 20:13:04 +0100 > In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for > dad-completed ipv6 addresses") I build the detection of the first > operational link-local address much to complex. Additionally this code > now has a race condition. > > Replace it with a much simpler variant, which just scans the address > list when duplicate address detection completes, to check if this is > the first valid link local address and send RS and MLD reports then. > > Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") > Reported-by: Jiri Pirko <jiri@resnulli.us> > Cc: Flavio Leitner <fbl@redhat.com> > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Applied and queued up for -stable, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index b58c36c..9650a3f 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -165,7 +165,6 @@ struct inet6_dev { struct net_device *dev; struct list_head addr_list; - int valid_ll_addr_cnt; struct ifmcaddr6 *mc_list; struct ifmcaddr6 *mc_tomb; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6913a82..f91e107 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3233,6 +3233,22 @@ out: in6_ifa_put(ifp); } +/* ifp->idev must be at least read locked */ +static bool ipv6_lonely_lladdr(struct inet6_ifaddr *ifp) +{ + struct inet6_ifaddr *ifpiter; + struct inet6_dev *idev = ifp->idev; + + list_for_each_entry(ifpiter, &idev->addr_list, if_list) { + if (ifp != ifpiter && ifpiter->scope == IFA_LINK && + (ifpiter->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE| + IFA_F_OPTIMISTIC|IFA_F_DADFAILED)) == + IFA_F_PERMANENT) + return false; + } + return true; +} + static void addrconf_dad_completed(struct inet6_ifaddr *ifp) { struct net_device *dev = ifp->idev->dev; @@ -3252,14 +3268,11 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) */ read_lock_bh(&ifp->idev->lock); - spin_lock(&ifp->lock); - send_mld = ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL && - ifp->idev->valid_ll_addr_cnt == 1; + send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp); send_rs = send_mld && ipv6_accept_ra(ifp->idev) && ifp->idev->cnf.rtr_solicits > 0 && (dev->flags&IFF_LOOPBACK) == 0; - spin_unlock(&ifp->lock); read_unlock_bh(&ifp->idev->lock); /* While dad is in progress mld report's source address is in6_addrany. @@ -4598,19 +4611,6 @@ errout: rtnl_set_sk_err(net, RTNLGRP_IPV6_PREFIX, err); } -static void update_valid_ll_addr_cnt(struct inet6_ifaddr *ifp, int count) -{ - write_lock_bh(&ifp->idev->lock); - spin_lock(&ifp->lock); - if (((ifp->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE|IFA_F_OPTIMISTIC| - IFA_F_DADFAILED)) == IFA_F_PERMANENT) && - (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) - ifp->idev->valid_ll_addr_cnt += count; - WARN_ON(ifp->idev->valid_ll_addr_cnt < 0); - spin_unlock(&ifp->lock); - write_unlock_bh(&ifp->idev->lock); -} - static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) { struct net *net = dev_net(ifp->idev->dev); @@ -4619,8 +4619,6 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) switch (event) { case RTM_NEWADDR: - update_valid_ll_addr_cnt(ifp, 1); - /* * If the address was optimistic * we inserted the route at the start of @@ -4636,8 +4634,6 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) ifp->idev->dev, 0, 0); break; case RTM_DELADDR: - update_valid_ll_addr_cnt(ifp, -1); - if (ifp->idev->cnf.forwarding) addrconf_leave_anycast(ifp); addrconf_leave_solict(ifp->idev, &ifp->addr);
In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") I build the detection of the first operational link-local address much to complex. Additionally this code now has a race condition. Replace it with a much simpler variant, which just scans the address list when duplicate address detection completes, to check if this is the first valid link local address and send RS and MLD reports then. Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") Reported-by: Jiri Pirko <jiri@resnulli.us> Cc: Flavio Leitner <fbl@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> --- include/net/if_inet6.h | 1 - net/ipv6/addrconf.c | 38 +++++++++++++++++--------------------- 2 files changed, 17 insertions(+), 22 deletions(-)