rtnetlink: allow to register ops without ops->setup set
So far, it is assumed that ops->setup is filled up. But there might be
case that ops might make sense even without ->setup. In that case,
forbid to newlink and dellink.
This allows to register simple rtnl link ops containing only ->kind.
That allows consistent way of passing device kind (either device-kind or
slave-kind) to userspace.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index de97741..6e2a2cd 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7091,7 +7091,7 @@
rtnl_lock_unregistering(net_list);
list_for_each_entry(net, net_list, exit_list) {
for_each_netdev_reverse(net, dev) {
- if (dev->rtnl_link_ops)
+ if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
else
unregister_netdevice_queue(dev, &dev_kill_list);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 1063996..27acaf7 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -299,7 +299,12 @@
if (rtnl_link_ops_get(ops->kind))
return -EEXIST;
- if (!ops->dellink)
+ /* The check for setup is here because if ops
+ * does not have that filled up, it is not possible
+ * to use the ops for creating device. So do not
+ * fill up dellink as well. That disables rtnl_dellink.
+ */
+ if (ops->setup && !ops->dellink)
ops->dellink = unregister_netdevice_queue;
list_add_tail(&ops->list, &link_ops);
@@ -1777,7 +1782,7 @@
return -ENODEV;
ops = dev->rtnl_link_ops;
- if (!ops)
+ if (!ops || !ops->dellink)
return -EOPNOTSUPP;
ops->dellink(dev, &list_kill);
@@ -2038,6 +2043,9 @@
return -EOPNOTSUPP;
}
+ if (!ops->setup)
+ return -EOPNOTSUPP;
+
if (!ifname[0])
snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
