| Message ID | 934e7797f7fb3541e36c01c5c753e0592679527b.1523956672.git.lorenzo.bianconi@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] ipv6: send netlink notifications for manually configured addresses | expand |
From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Date: Tue, 17 Apr 2018 11:54:39 +0200 > Send a netlink notification when userspace adds a manually configured > address if DAD is enabled and optimistic flag isn't set. > Moreover send RTM_DELADDR notifications for tentative addresses. > > Some userspace applications (e.g. NetworkManager) are interested in > addr netlink events albeit the address is still in tentative state, > however events are not sent if DAD process is not completed. > If the address is added and immediately removed userspace listeners > are not notified. This behaviour can be easily reproduced by using > veth interfaces: > > $ ip -b - <<EOF >> link add dev vm1 type veth peer name vm2 >> link set dev vm1 up >> link set dev vm2 up >> addr add 2001:db8:a:b:1:2:3:4/64 dev vm1 >> addr del 2001:db8:a:b:1:2:3:4/64 dev vm1 > EOF > > This patch reverts the behaviour introduced by the commit f784ad3d79e5 > ("ipv6: do not send RTM_DELADDR for tentative addresses") > > Suggested-by: Thomas Haller <thaller@redhat.com> > Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Ok, applied to net-next. It would be really nice if we clearly documented somewhere the exact situations where we desire ipv6 address netlink notifications to be sent out. Maybe even a common function that guards the event emission, where we encode the rules. Or a comment somewhere prominent. Something like that. Right now this isn't spelled out clearly anywhere, and that's probably why things keep being adjusted back and forth like this. Thank you.
> From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> > Date: Tue, 17 Apr 2018 11:54:39 +0200 > >> Send a netlink notification when userspace adds a manually configured >> address if DAD is enabled and optimistic flag isn't set. >> Moreover send RTM_DELADDR notifications for tentative addresses. >> >> Some userspace applications (e.g. NetworkManager) are interested in >> addr netlink events albeit the address is still in tentative state, >> however events are not sent if DAD process is not completed. >> If the address is added and immediately removed userspace listeners >> are not notified. This behaviour can be easily reproduced by using >> veth interfaces: >> >> $ ip -b - <<EOF >>> link add dev vm1 type veth peer name vm2 >>> link set dev vm1 up >>> link set dev vm2 up >>> addr add 2001:db8:a:b:1:2:3:4/64 dev vm1 >>> addr del 2001:db8:a:b:1:2:3:4/64 dev vm1 >> EOF >> >> This patch reverts the behaviour introduced by the commit f784ad3d79e5 >> ("ipv6: do not send RTM_DELADDR for tentative addresses") >> >> Suggested-by: Thomas Haller <thaller@redhat.com> >> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> > > Ok, applied to net-next. > > It would be really nice if we clearly documented somewhere the exact > situations where we desire ipv6 address netlink notifications to be > sent out. > > Maybe even a common function that guards the event emission, where we > encode the rules. Or a comment somewhere prominent. Something like > that. > > Right now this isn't spelled out clearly anywhere, and that's probably > why things keep being adjusted back and forth like this. Sounds good, I will post a patch. Thanks Regards, Lorenzo > > Thank you.
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 62b97722722c..b2c0175125db 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2901,6 +2901,11 @@ static int inet6_addr_add(struct net *net, int ifindex, expires, flags); } + /* Send a netlink notification if DAD is enabled and + * optimistic flag is not set + */ + if (!(ifp->flags & (IFA_F_OPTIMISTIC | IFA_F_NODAD))) + ipv6_ifa_notify(0, ifp); /* * Note that section 3.1 of RFC 4429 indicates * that the Optimistic flag should not be set for @@ -5028,14 +5033,6 @@ static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa) struct net *net = dev_net(ifa->idev->dev); int err = -ENOBUFS; - /* Don't send DELADDR notification for TENTATIVE address, - * since NEWADDR notification is sent only after removing - * TENTATIVE flag, if DAD has not failed. - */ - if (ifa->flags & IFA_F_TENTATIVE && !(ifa->flags & IFA_F_DADFAILED) && - event == RTM_DELADDR) - return; - skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_ATOMIC); if (!skb) goto errout;