net: Add extack argument to ndo_fdb_add()

Drivers may not be able to support certain FDB entries, and an error
code is insufficient to give clear hints as to the reasons of rejection.

In order to make it possible to communicate the rejection reason, extend
ndo_fdb_add() with an extack argument. Adapt the existing
implementations of ndo_fdb_add() to take the parameter (and ignore it).
Pass the extack parameter when invoking ndo_fdb_add() from rtnl_fdb_add().

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 11 insertions, 6 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index fe3c758791ca..6664cb8590f8 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -915,7 +915,8 @@ static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 	       struct net_device *dev,
-	       const unsigned char *addr, u16 vid, u16 nlh_flags)
+	       const unsigned char *addr, u16 vid, u16 nlh_flags,
+	       struct netlink_ext_ack *extack)
 {
 	struct net_bridge_vlan_group *vg;
 	struct net_bridge_port *p = NULL;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index eabf8bf28a3f..00deef7fc1f3 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -573,7 +573,8 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 		  struct net_device *dev, const unsigned char *addr, u16 vid);
 int br_fdb_add(struct ndmsg *nlh, struct nlattr *tb[], struct net_device *dev,
-	       const unsigned char *addr, u16 vid, u16 nlh_flags);
+	       const unsigned char *addr, u16 vid, u16 nlh_flags,
+	       struct netlink_ext_ack *extack);
 int br_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 		struct net_device *dev, struct net_device *fdev, int *idx);
 int br_fdb_get(struct sk_buff *skb, struct nlattr *tb[], struct net_device *dev,
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5ea1bed08ede..b302df0cd5ae 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3639,7 +3639,7 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 		const struct net_device_ops *ops = br_dev->netdev_ops;
 
 		err = ops->ndo_fdb_add(ndm, tb, dev, addr, vid,
-				       nlh->nlmsg_flags);
+				       nlh->nlmsg_flags, extack);
 		if (err)
 			goto out;
 		else
@@ -3651,7 +3651,8 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 		if (dev->netdev_ops->ndo_fdb_add)
 			err = dev->netdev_ops->ndo_fdb_add(ndm, tb, dev, addr,
 							   vid,
-							   nlh->nlmsg_flags);
+							   nlh->nlmsg_flags,
+							   extack);
 		else
 			err = ndo_dflt_fdb_add(ndm, tb, dev, addr, vid,
 					       nlh->nlmsg_flags);
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 026a05774bf7..1f4972dab9f2 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -103,7 +103,8 @@ static inline void dsa_legacy_unregister(void) { }
 int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev,
 		       const unsigned char *addr, u16 vid,
-		       u16 flags);
+		       u16 flags,
+		       struct netlink_ext_ack *extack);
 int dsa_legacy_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev,
 		       const unsigned char *addr, u16 vid);
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index a3fcc1d01615..d5680a98a7f0 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1009,7 +1009,8 @@ static const struct ethtool_ops dsa_slave_ethtool_ops = {
 int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev,
 		       const unsigned char *addr, u16 vid,
-		       u16 flags)
+		       u16 flags,
+		       struct netlink_ext_ack *extack)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);