[PATCHv5 net-next 4/4] rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link

[Hangbin Liu <liuhangbin@gmail.com>]

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 pid info.

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 include/net/rtnetlink.h        | 2 +-
 net/core/rtnetlink.c           | 7 ++++---
 net/openvswitch/vport-geneve.c | 2 +-
 net/openvswitch/vport-gre.c    | 2 +-
 net/openvswitch/vport-netdev.c | 2 +-
 net/openvswitch/vport-vxlan.c  | 2 +-
 6 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index bf8bb3357825..1a152993caef 100644
--- a/include/net/rtnetlink.h
+++ b/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, struct nlmsghdr *nlh, u32 pid);
 int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm);
 
 int rtnl_nla_parse_ifla(struct nlattr **tb, const struct nlattr *head, int len,
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index da9a6fd156d8..3144ec7324b9 100644
--- a/net/core/rtnetlink.c
+++ b/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, struct nlmsghdr *nlh, u32 pid)
 {
 	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, nlh, pid);
 
 	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 pid = 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, nlh, pid);
 
 out:
 	if (netnsid >= 0)
diff --git a/net/openvswitch/vport-geneve.c b/net/openvswitch/vport-geneve.c
index 89a8e1501809..0e11ff8ee5ce 100644
--- a/net/openvswitch/vport-geneve.c
+++ b/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, NULL, 0);
 		rtnl_unlock();
 		ovs_vport_free(vport);
 		goto error;
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index e6b5e76a962a..3a299383fca0 100644
--- a/net/openvswitch/vport-gre.c
+++ b/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, NULL, 0);
 		rtnl_unlock();
 		ovs_vport_free(vport);
 		return ERR_PTR(err);
diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c
index 2f61d5bdce1a..1bead7854593 100644
--- a/net/openvswitch/vport-netdev.c
+++ b/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, NULL, 0);
 	netdev_put(vport->dev, &vport->dev_tracker);
 	vport->dev = NULL;
 	rtnl_unlock();
diff --git a/net/openvswitch/vport-vxlan.c b/net/openvswitch/vport-vxlan.c
index 188e9c1360a1..dae8eb1a6e7a 100644
--- a/net/openvswitch/vport-vxlan.c
+++ b/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, NULL, 0);
 		rtnl_unlock();
 		ovs_vport_free(vport);
 		goto error;
-- 
2.37.2