Merge branch 'vxlan-FDB-veto'

Petr Machata says:

====================
vxlan: Allow vetoing FDB operations

mlxsw does not implement handling of the more advanced types of VXLAN
FDB entries. In order to provide visibility to users, it is important to
be able to reject such FDB entries, ideally with an explanation passed
in extended ack. This patch set implements this.

In patches #1-#4, vxlan is gradually transformed to support vetoing of
FDB entries added (or modified) through vxlan_fdb_update(), and the
default FDB entry added in __vxlan_dev_create().

Patches #5-#7 deal with vxlan_changelink(). The existing code recognizes
that vxlan_fdb_update() may fail, but doesn't attempt to keep things
intact if it does. These patches change the function in several steps to
gracefully handle vetoes (or other failures).

Then in patches #8-#11, extack arguments are added, respectively, to
ndo_fdb_add(), mlxsw's mlxsw_sp_nve_ops.fdb_replay, the functions that
connect to the VXLAN vetoing code, and call_switchdev_notifiers(). Note
that call_switchdev_blocking_notifiers() already does support extack.

Finally in patch #12, mlxsw is extended to add extack messages to
rejected FDB entries. In patch #13, the functionality is tested.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 12 insertions, 6 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1377d085ef99..a57b9a853aab 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1152,7 +1152,8 @@ struct dev_ifalias {
  *
  * int (*ndo_fdb_add)(struct ndmsg *ndm, struct nlattr *tb[],
  *		      struct net_device *dev,
- *		      const unsigned char *addr, u16 vid, u16 flags)
+ *		      const unsigned char *addr, u16 vid, u16 flags,
+ *		      struct netlink_ext_ack *extack);
  *	Adds an FDB entry to dev for addr.
  * int (*ndo_fdb_del)(struct ndmsg *ndm, struct nlattr *tb[],
  *		      struct net_device *dev,
@@ -1376,7 +1377,8 @@ struct net_device_ops {
 					       struct net_device *dev,
 					       const unsigned char *addr,
 					       u16 vid,
-					       u16 flags);
+					       u16 flags,
+					       struct netlink_ext_ack *extack);
 	int			(*ndo_fdb_del)(struct ndmsg *ndm,
 					       struct nlattr *tb[],
 					       struct net_device *dev,
diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index a7fdab5ee6c3..63843ae5dc81 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -195,7 +195,8 @@ int switchdev_port_obj_del(struct net_device *dev,
 int register_switchdev_notifier(struct notifier_block *nb);
 int unregister_switchdev_notifier(struct notifier_block *nb);
 int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
-			     struct switchdev_notifier_info *info);
+			     struct switchdev_notifier_info *info,
+			     struct netlink_ext_ack *extack);
 
 int register_switchdev_blocking_notifier(struct notifier_block *nb);
 int unregister_switchdev_blocking_notifier(struct notifier_block *nb);
@@ -267,7 +268,8 @@ static inline int unregister_switchdev_notifier(struct notifier_block *nb)
 
 static inline int call_switchdev_notifiers(unsigned long val,
 					   struct net_device *dev,
-					   struct switchdev_notifier_info *info)
+					   struct switchdev_notifier_info *info,
+					   struct netlink_ext_ack *extack)
 {
 	return NOTIFY_DONE;
 }
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index 236403eb5ba6..09767819c3d4 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -428,7 +428,8 @@ struct switchdev_notifier_vxlan_fdb_info {
 int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 		      struct switchdev_notifier_vxlan_fdb_info *fdb_info);
 int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
-		     struct notifier_block *nb);
+		     struct notifier_block *nb,
+		     struct netlink_ext_ack *extack);
 void vxlan_fdb_clear_offload(const struct net_device *dev, __be32 vni);
 
 #else
@@ -440,7 +441,8 @@ vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 }
 
 static inline int vxlan_fdb_replay(const struct net_device *dev, __be32 vni,
-				   struct notifier_block *nb)
+				   struct notifier_block *nb,
+				   struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }