[RFC PATCH net-next 4/5] vxlan: support for nexthop notifiers

[Roopa Prabhu]

From: Roopa Prabhu <ro...@cumulusnetworks.com>

vxlan driver registers for nexthop add/del notifiers to
cleanup fdb entries pointing to nexthops.

Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
---
 drivers/net/vxlan.c | 36 +++++++++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 176f2b3..df6c5ff 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -81,6 +81,7 @@ struct vxlan_fdb {
        u16               flags;        /* see ndm_flags and below */
        struct list_head  nh_list;
        struct nexthop    *nh;
+       struct vxlan_dev  *vdev;
 };
 
 #define NTF_VXLAN_ADDED_BY_USER 0x100
@@ -811,8 +812,9 @@ static int vxlan_gro_complete(struct sock *sk, struct 
sk_buff *skb, int nhoff)
        return eth_gro_complete(skb, nhoff + sizeof(struct vxlanhdr));
 }
 
-static struct vxlan_fdb *vxlan_fdb_alloc(const u8 *mac, __u16 state,
-                                        __be32 src_vni, __u16 ndm_flags)
+static struct vxlan_fdb *vxlan_fdb_alloc(struct vxlan_dev *vxlan, const u8 
*mac,
+                                        __u16 state, __be32 src_vni,
+                                        __u16 ndm_flags)
 {
        struct vxlan_fdb *f;
 
@@ -824,6 +826,7 @@ static struct vxlan_fdb *vxlan_fdb_alloc(const u8 *mac, 
__u16 state,
        f->updated = f->used = jiffies;
        f->vni = src_vni;
        f->nh = NULL;
+       f->vdev = vxlan;
        INIT_LIST_HEAD(&f->nh_list);
        INIT_LIST_HEAD(&f->remotes);
        memcpy(f->eth_addr, mac, ETH_ALEN);
@@ -902,7 +905,7 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan,
                return -ENOSPC;
 
        netdev_dbg(vxlan->dev, "add %pM -> %pIS\n", mac, ip);
-       f = vxlan_fdb_alloc(mac, state, src_vni, ndm_flags);
+       f = vxlan_fdb_alloc(vxlan, mac, state, src_vni, ndm_flags);
        if (!f)
                return -ENOMEM;
 
@@ -954,6 +957,7 @@ static void vxlan_fdb_destroy(struct vxlan_dev *vxlan, 
struct vxlan_fdb *f,
                                         swdev_notify, NULL);
 
        hlist_del_rcu(&f->hlist);
+       f->vdev = NULL;
        call_rcu(&f->rcu, vxlan_fdb_free);
 }
 
@@ -4576,6 +4580,25 @@ static struct notifier_block 
vxlan_switchdev_notifier_block __read_mostly = {
        .notifier_call = vxlan_switchdev_event,
 };
 
+static int vxlan_nexthop_event(struct notifier_block *nb,
+                              unsigned long event, void *ptr)
+{
+       struct nexthop *nh = ptr;
+       struct vxlan_fdb *fdb;
+
+       if (!nh || event != NEXTHOP_EVENT_DEL)
+               return NOTIFY_DONE;
+
+       list_for_each_entry(fdb, &nh->fdb_list, nh_list)
+               vxlan_fdb_destroy(fdb->vdev, fdb, true, false);
+
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block vxlan_nexthop_notifier_block __read_mostly = {
+       .notifier_call = vxlan_nexthop_event,
+};
+
 static __net_init int vxlan_init_net(struct net *net)
 {
        struct vxlan_net *vn = net_generic(net, vxlan_net_id);
@@ -4655,7 +4678,13 @@ static int __init vxlan_init_module(void)
        if (rc)
                goto out4;
 
+       rc = register_nexthop_notifier(&vxlan_nexthop_notifier_block);
+       if (rc)
+               goto out5;
+
        return 0;
+out5:
+       rtnl_link_unregister(&vxlan_link_ops);
 out4:
        unregister_switchdev_notifier(&vxlan_switchdev_notifier_block);
 out3:
@@ -4672,6 +4701,7 @@ static void __exit vxlan_cleanup_module(void)
        rtnl_link_unregister(&vxlan_link_ops);
        unregister_switchdev_notifier(&vxlan_switchdev_notifier_block);
        unregister_netdevice_notifier(&vxlan_notifier_block);
+       unregister_nexthop_notifier(&vxlan_nexthop_notifier_block);
        unregister_pernet_subsys(&vxlan_net_ops);
        /* rcu_barrier() is called by netns */
 }
-- 
2.1.4