vxlan: Add switchdev notifications

When offloading VXLAN devices, drivers need to know about events in
VXLAN FDB database. Since VXLAN models a bridge, it is natural to
distribute the VXLAN FDB notifications using the pre-existing switchdev
notification mechanism.

To that end, introduce two new notification types:
SWITCHDEV_VXLAN_FDB_ADD_TO_DEVICE and SWITCHDEV_VXLAN_FDB_DEL_TO_DEVICE.
Introduce a new function, vxlan_fdb_switchdev_call_notifiers() to send
the new notifier types, and a struct switchdev_notifier_vxlan_fdb_info
to communicate the details of the FDB entry under consideration.

Invoke the new function from vxlan_fdb_notify().

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

drivers/net/vxlan.c

@@ -327,8 +327,8 @@ static inline size_t vxlan_nlmsg_size(void)
 		+ nla_total_size(sizeof(struct nda_cacheinfo));
 }
 
-static void vxlan_fdb_notify(struct vxlan_dev *vxlan, struct vxlan_fdb *fdb,
-			     struct vxlan_rdst *rd, int type)
+static void __vxlan_fdb_notify(struct vxlan_dev *vxlan, struct vxlan_fdb *fdb,
+			       struct vxlan_rdst *rd, int type)
 {
 	struct net *net = dev_net(vxlan->dev);
 	struct sk_buff *skb;
@@ -353,6 +353,48 @@ errout:
 		rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 }
 
+static void vxlan_fdb_switchdev_call_notifiers(struct vxlan_dev *vxlan,
+					       struct vxlan_fdb *fdb,
+					       struct vxlan_rdst *rd,
+					       bool adding)
+{
+	struct switchdev_notifier_vxlan_fdb_info info;
+	enum switchdev_notifier_type notifier_type;
+
+	if (WARN_ON(!rd))
+		return;
+
+	notifier_type = adding ? SWITCHDEV_VXLAN_FDB_ADD_TO_DEVICE
+			       : SWITCHDEV_VXLAN_FDB_DEL_TO_DEVICE;
+
+	info = (struct switchdev_notifier_vxlan_fdb_info){
+		.remote_ip = rd->remote_ip,
+		.remote_port = rd->remote_port,
+		.remote_vni = rd->remote_vni,
+		.remote_ifindex = rd->remote_ifindex,
+		.vni = fdb->vni,
+	};
+	memcpy(info.eth_addr, fdb->eth_addr, ETH_ALEN);
+
+	call_switchdev_notifiers(notifier_type, vxlan->dev,
+				 &info.info);
+}
+
+static void vxlan_fdb_notify(struct vxlan_dev *vxlan, struct vxlan_fdb *fdb,
+			     struct vxlan_rdst *rd, int type)
+{
+	switch (type) {
+	case RTM_NEWNEIGH:
+		vxlan_fdb_switchdev_call_notifiers(vxlan, fdb, rd, true);
+		break;
+	case RTM_DELNEIGH:
+		vxlan_fdb_switchdev_call_notifiers(vxlan, fdb, rd, false);
+		break;
+	}
+
+	__vxlan_fdb_notify(vxlan, fdb, rd, type);
+}
+
 static void vxlan_ip_miss(struct net_device *dev, union vxlan_addr *ipa)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);

include/net/switchdev.h

@@ -145,6 +145,9 @@ enum switchdev_notifier_type {
 	SWITCHDEV_FDB_ADD_TO_DEVICE,
 	SWITCHDEV_FDB_DEL_TO_DEVICE,
 	SWITCHDEV_FDB_OFFLOADED,
+
+	SWITCHDEV_VXLAN_FDB_ADD_TO_DEVICE,
+	SWITCHDEV_VXLAN_FDB_DEL_TO_DEVICE,
 };
 
 struct switchdev_notifier_info {

include/net/vxlan.h

@@ -6,6 +6,7 @@
 #include <net/udp_tunnel.h>
 #include <net/dst_metadata.h>
 #include <net/rtnetlink.h>
+#include <net/switchdev.h>
 
 /* VXLAN protocol (RFC 7348) header:
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@@ -409,4 +410,14 @@ static inline bool netif_is_vxlan(const struct net_device *dev)
 	       !strcmp(dev->rtnl_link_ops->kind, "vxlan");
 }
 
+struct switchdev_notifier_vxlan_fdb_info {
+	struct switchdev_notifier_info info; /* must be first */
+	union vxlan_addr remote_ip;
+	__be16 remote_port;
+	__be32 remote_vni;
+	u32 remote_ifindex;
+	u8 eth_addr[ETH_ALEN];
+	__be32 vni;
+};
+
 #endif