ipv6: support IFA_F_MANAGETEMPADDR for address deletion too

Userspace applications can use IFA_F_MANAGETEMPADDR with RTM_NEWADDR
already to indicate that the kernel should take care of temporary
address management.

This patch adds related functionality to RTM_DELADDR. By setting
IFA_F_MANAGETEMPADDR a userspace application can indicate that the kernel
should delete all related temporary addresses as well.

A corresponding patch for the "ip addr del" command has been applied to
iproute2 already.
Signed-off-by: Heiner Kallweit <heiner.kallweit@web.de>
Reviewed-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/addrconf.c

@@ -2504,8 +2504,8 @@ static int inet6_addr_add(struct net *net, int ifindex,
 	return PTR_ERR(ifp);
 }
 
-static int inet6_addr_del(struct net *net, int ifindex, const struct in6_addr *pfx,
-			  unsigned int plen)
+static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags,
+			  const struct in6_addr *pfx, unsigned int plen)
 {
 	struct inet6_ifaddr *ifp;
 	struct inet6_dev *idev;
@@ -2528,7 +2528,12 @@ static int inet6_addr_del(struct net *net, int ifindex, const struct in6_addr *p
 			in6_ifa_hold(ifp);
 			read_unlock_bh(&idev->lock);
 
+			if (!(ifp->flags & IFA_F_TEMPORARY) &&
+			    (ifa_flags & IFA_F_MANAGETEMPADDR))
+				manage_tempaddrs(idev, ifp, 0, 0, false,
+						 jiffies);
 			ipv6_del_addr(ifp);
+			addrconf_verify_rtnl();
 			return 0;
 		}
 	}
@@ -2568,7 +2573,7 @@ int addrconf_del_ifaddr(struct net *net, void __user *arg)
 		return -EFAULT;
 
 	rtnl_lock();
-	err = inet6_addr_del(net, ireq.ifr6_ifindex, &ireq.ifr6_addr,
+	err = inet6_addr_del(net, ireq.ifr6_ifindex, 0, &ireq.ifr6_addr,
 			     ireq.ifr6_prefixlen);
 	rtnl_unlock();
 	return err;
@@ -3743,6 +3748,7 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct ifaddrmsg *ifm;
 	struct nlattr *tb[IFA_MAX+1];
 	struct in6_addr *pfx, *peer_pfx;
+	u32 ifa_flags;
 	int err;
 
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
@@ -3754,7 +3760,13 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh)
 	if (pfx == NULL)
 		return -EINVAL;
 
-	return inet6_addr_del(net, ifm->ifa_index, pfx, ifm->ifa_prefixlen);
+	ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : ifm->ifa_flags;
+
+	/* We ignore other flags so far. */
+	ifa_flags &= IFA_F_MANAGETEMPADDR;
+
+	return inet6_addr_del(net, ifm->ifa_index, ifa_flags, pfx,
+			      ifm->ifa_prefixlen);
 }
 
 static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 ifa_flags,