ndo_fdb_add: Add a parameter to report whether notification was sent

Currently when FDB entries are added to or deleted from a VXLAN netdevice,
the VXLAN driver emits one notification, including the VXLAN-specific
attributes. The core however always sends a notification as well, a generic
one. Thus two notifications are unnecessarily sent for these operations. A
similar situation comes up with bridge driver, which also emits
notifications on its own:

 # ip link add name vx type vxlan id 1000 dstport 4789
 # bridge monitor fdb &
 [1] 1981693
 # bridge fdb add de:ad:be:ef:13:37 dev vx self dst 192.0.2.1
 de:ad:be:ef:13:37 dev vx dst 192.0.2.1 self permanent
 de:ad:be:ef:13:37 dev vx self permanent

In order to prevent this duplicity, add a paremeter to ndo_fdb_add,
bool *notified. The flag is primed to false, and if the callee sends a
notification on its own, it sets it to true, thus informing the core that
it should not generate another notification.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/cbf6ae8195e85cbf922f8058ce4eba770f3b71ed.1731589511.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

12 files changed, 32 insertions, 18 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 55fb362eb508..ab5febf83ec3 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -13095,12 +13095,13 @@ static int i40e_get_phys_port_id(struct net_device *netdev,
  * @addr: the MAC address entry being added
  * @vid: VLAN ID
  * @flags: instructions from stack about fdb operation
+ * @notified: whether notification was emitted
  * @extack: netlink extended ack, unused currently
  */
 static int i40e_ndo_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			    struct net_device *dev,
 			    const unsigned char *addr, u16 vid,
-			    u16 flags,
+			    u16 flags, bool *notified,
 			    struct netlink_ext_ack *extack)
 {
 	struct i40e_netdev_priv *np = netdev_priv(dev);
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index a6f586f9bfd1..c875036f654b 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -6125,12 +6125,14 @@ ice_set_tx_maxrate(struct net_device *netdev, int queue_index, u32 maxrate)
  * @addr: the MAC address entry being added
  * @vid: VLAN ID
  * @flags: instructions from stack about fdb operation
+ * @notified: whether notification was emitted
  * @extack: netlink extended ack
  */
 static int
 ice_fdb_add(struct ndmsg *ndm, struct nlattr __always_unused *tb[],
 	    struct net_device *dev, const unsigned char *addr, u16 vid,
-	    u16 flags, struct netlink_ext_ack __always_unused *extack)
+	    u16 flags, bool *notified,
+	    struct netlink_ext_ack __always_unused *extack)
 {
 	int err;
 
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index f1d088168723..f0528bd13184 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2486,7 +2486,7 @@ static int igb_set_features(struct net_device *netdev,
 static int igb_ndo_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			   struct net_device *dev,
 			   const unsigned char *addr, u16 vid,
-			   u16 flags,
+			   u16 flags, bool *notified,
 			   struct netlink_ext_ack *extack)
 {
 	/* guarantee we can provide a unique filter for the unicast address */
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 8b8404d8c946..adc9392463ce 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -9954,7 +9954,7 @@ static int ixgbe_set_features(struct net_device *netdev,
 static int ixgbe_ndo_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			     struct net_device *dev,
 			     const unsigned char *addr, u16 vid,
-			     u16 flags,
+			     u16 flags, bool *notified,
 			     struct netlink_ext_ack *extack)
 {
 	/* guarantee we can provide a unique filter for the unicast address */
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 7c9540a71725..4f15ba2c5525 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -730,7 +730,7 @@ static void ocelot_get_stats64(struct net_device *dev,
 static int ocelot_port_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			       struct net_device *dev,
 			       const unsigned char *addr,
-			       u16 vid, u16 flags,
+			       u16 vid, u16 flags, bool *notified,
 			       struct netlink_ext_ack *extack)
 {
 	struct ocelot_port_private *priv = netdev_priv(dev);
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
index b3588a1ebc25..2484cebd97d4 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
@@ -394,7 +394,7 @@ static int qlcnic_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
 static int qlcnic_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			struct net_device *netdev,
 			const unsigned char *addr, u16 vid, u16 flags,
-			struct netlink_ext_ack *extack)
+			bool *notified, struct netlink_ext_ack *extack)
 {
 	struct qlcnic_adapter *adapter = netdev_priv(netdev);
 	int err = 0;
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index edbd5afcec41..dfb462e63248 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1024,7 +1024,7 @@ static int macvlan_vlan_rx_kill_vid(struct net_device *dev,
 static int macvlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			   struct net_device *dev,
 			   const unsigned char *addr, u16 vid,
-			   u16 flags,
+			   u16 flags, bool *notified,
 			   struct netlink_ext_ack *extack)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 42b07bc2b107..22f17c5c7549 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1241,7 +1241,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			 struct net_device *dev,
 			 const unsigned char *addr, u16 vid, u16 flags,
-			 struct netlink_ext_ack *extack)
+			 bool *notified, struct netlink_ext_ack *extack)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	/* struct net *net = dev_net(vxlan->dev); */
@@ -1277,6 +1277,9 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			       nhid, true, extack);
 	spin_unlock_bh(&vxlan->hash_lock[hash_index]);
 
+	if (!err)
+		*notified = true;
+
 	return err;
 }
 
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0aae346d919e..6a7fd191e1ee 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1248,8 +1248,10 @@ struct netdev_net_notifier {
  * int (*ndo_fdb_add)(struct ndmsg *ndm, struct nlattr *tb[],
  *		      struct net_device *dev,
  *		      const unsigned char *addr, u16 vid, u16 flags,
- *		      struct netlink_ext_ack *extack);
+ *		      bool *notified, struct netlink_ext_ack *extack);
  *	Adds an FDB entry to dev for addr.
+ *	Callee shall set *notified to true if it sent any appropriate
+ *	notification(s). Otherwise core will send a generic one.
  * int (*ndo_fdb_del)(struct ndmsg *ndm, struct nlattr *tb[],
  *		      struct net_device *dev,
  *		      const unsigned char *addr, u16 vid)
@@ -1525,6 +1527,7 @@ struct net_device_ops {
 					       const unsigned char *addr,
 					       u16 vid,
 					       u16 flags,
+					       bool *notified,
 					       struct netlink_ext_ack *extack);
 	int			(*ndo_fdb_del)(struct ndmsg *ndm,
 					       struct nlattr *tb[],
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 77f110035df1..5f29958f3ddd 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -1152,7 +1152,7 @@ static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 			struct net_bridge_port *p, const unsigned char *addr,
 			u16 nlh_flags, u16 vid, struct nlattr *nfea_tb[],
-			struct netlink_ext_ack *extack)
+			bool *notified, struct netlink_ext_ack *extack)
 {
 	int err = 0;
 
@@ -1183,6 +1183,8 @@ static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 		spin_unlock_bh(&br->hash_lock);
 	}
 
+	if (!err)
+		*notified = true;
 	return err;
 }
 
@@ -1195,7 +1197,7 @@ static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = {
 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 	       struct net_device *dev,
 	       const unsigned char *addr, u16 vid, u16 nlh_flags,
-	       struct netlink_ext_ack *extack)
+	       bool *notified, struct netlink_ext_ack *extack)
 {
 	struct nlattr *nfea_tb[NFEA_MAX + 1], *attr;
 	struct net_bridge_vlan_group *vg;
@@ -1258,10 +1260,10 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 
 		/* VID was specified, so use it. */
 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid, nfea_tb,
-				   extack);
+				   notified, extack);
 	} else {
 		err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0, nfea_tb,
-				   extack);
+				   notified, extack);
 		if (err || !vg || !vg->num_vlans)
 			goto out;
 
@@ -1273,7 +1275,7 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			if (!br_vlan_should_use(v))
 				continue;
 			err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid,
-					   nfea_tb, extack);
+					   nfea_tb, notified, extack);
 			if (err)
 				goto out;
 		}
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 041f6e571a20..ebfc59049ec1 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -858,7 +858,7 @@ int br_fdb_delete_bulk(struct nlmsghdr *nlh, struct net_device *dev,
 		       struct netlink_ext_ack *extack);
 int br_fdb_add(struct ndmsg *nlh, struct nlattr *tb[], struct net_device *dev,
 	       const unsigned char *addr, u16 vid, u16 nlh_flags,
-	       struct netlink_ext_ack *extack);
+	       bool *notified, 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 327fa4957929..f31b2436cde5 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4578,9 +4578,10 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 	    netif_is_bridge_port(dev)) {
 		struct net_device *br_dev = netdev_master_upper_dev_get(dev);
 		const struct net_device_ops *ops = br_dev->netdev_ops;
+		bool notified = false;
 
 		err = ops->ndo_fdb_add(ndm, tb, dev, addr, vid,
-				       nlh->nlmsg_flags, extack);
+				       nlh->nlmsg_flags, &notified, extack);
 		if (err)
 			goto out;
 		else
@@ -4589,16 +4590,18 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	/* Embedded bridge, macvlan, and any other device support */
 	if ((ndm->ndm_flags & NTF_SELF)) {
+		bool notified = false;
+
 		if (dev->netdev_ops->ndo_fdb_add)
 			err = dev->netdev_ops->ndo_fdb_add(ndm, tb, dev, addr,
 							   vid,
 							   nlh->nlmsg_flags,
-							   extack);
+							   &notified, extack);
 		else
 			err = ndo_dflt_fdb_add(ndm, tb, dev, addr, vid,
 					       nlh->nlmsg_flags);
 
-		if (!err) {
+		if (!err && !notified) {
 			rtnl_fdb_notify(dev, addr, vid, RTM_NEWNEIGH,
 					ndm->ndm_state);
 			ndm->ndm_flags &= ~NTF_SELF;