rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link

This patch use the new helper unregister_netdevice_many_notify() for
rtnl_delete_link(), so that the kernel could reply unicast when userspace
 set NLM_F_ECHO flag to request the new created interface info.

At the same time, the parameters of rtnl_delete_link() need to be updated
since we need nlmsghdr and portid info.
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/rtnetlink.h

@@ -186,7 +186,7 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
 				    const struct rtnl_link_ops *ops,
 				    struct nlattr *tb[],
 				    struct netlink_ext_ack *extack);
-int rtnl_delete_link(struct net_device *dev);
+int rtnl_delete_link(struct net_device *dev, u32 portid, const struct nlmsghdr *nlh);
 int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,
 			u32 portid, const struct nlmsghdr *nlh);
 

net/core/rtnetlink.c

@@ -3110,7 +3110,7 @@ static int rtnl_group_dellink(const struct net *net, int group)
 	return 0;
 }
 
-int rtnl_delete_link(struct net_device *dev)
+int rtnl_delete_link(struct net_device *dev, u32 portid, const struct nlmsghdr *nlh)
 {
 	const struct rtnl_link_ops *ops;
 	LIST_HEAD(list_kill);
@@ -3120,7 +3120,7 @@ int rtnl_delete_link(struct net_device *dev)
 		return -EOPNOTSUPP;
 
 	ops->dellink(dev, &list_kill);
-	unregister_netdevice_many(&list_kill);
+	unregister_netdevice_many_notify(&list_kill, portid, nlh);
 
 	return 0;
 }
@@ -3130,6 +3130,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
+	u32 portid = NETLINK_CB(skb).portid;
 	struct net *tgt_net = net;
 	struct net_device *dev = NULL;
 	struct ifinfomsg *ifm;
@@ -3171,7 +3172,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 		goto out;
 	}
 
-	err = rtnl_delete_link(dev);
+	err = rtnl_delete_link(dev, portid, nlh);
 
 out:
 	if (netnsid >= 0)

net/openvswitch/vport-geneve.c

@@ -91,7 +91,7 @@ static struct vport *geneve_tnl_create(const struct vport_parms *parms)
 
 	err = dev_change_flags(dev, dev->flags | IFF_UP, NULL);
 	if (err < 0) {
-		rtnl_delete_link(dev);
+		rtnl_delete_link(dev, 0, NULL);
 		rtnl_unlock();
 		ovs_vport_free(vport);
 		goto error;

net/openvswitch/vport-gre.c

@@ -57,7 +57,7 @@ static struct vport *gre_tnl_create(const struct vport_parms *parms)
 
 	err = dev_change_flags(dev, dev->flags | IFF_UP, NULL);
 	if (err < 0) {
-		rtnl_delete_link(dev);
+		rtnl_delete_link(dev, 0, NULL);
 		rtnl_unlock();
 		ovs_vport_free(vport);
 		return ERR_PTR(err);

net/openvswitch/vport-netdev.c

@@ -172,7 +172,7 @@ void ovs_netdev_tunnel_destroy(struct vport *vport)
 	 * if it's not already shutting down.
 	 */
 	if (vport->dev->reg_state == NETREG_REGISTERED)
-		rtnl_delete_link(vport->dev);
+		rtnl_delete_link(vport->dev, 0, NULL);
 	netdev_put(vport->dev, &vport->dev_tracker);
 	vport->dev = NULL;
 	rtnl_unlock();

net/openvswitch/vport-vxlan.c

@@ -120,7 +120,7 @@ static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
 
 	err = dev_change_flags(dev, dev->flags | IFF_UP, NULL);
 	if (err < 0) {
-		rtnl_delete_link(dev);
+		rtnl_delete_link(dev, 0, NULL);
 		rtnl_unlock();
 		ovs_vport_free(vport);
 		goto error;