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

Hangbin Liu
2022-09-30T09:46:12Z

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