vxlan: allow removal of single destination from fdb entry

When the last item is deleted from the remote destinations list, the
fdb entry is destroyed.

Signed-off-by: Mike Rapoport <mike.rapoport@ravellosystems.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

1 files changed, 40 insertions, 4 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index ee7cc71e57fd..c1825201f9e2 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -105,6 +105,7 @@ struct vxlan_rdst {
         u32                      remote_vni;
         u32                      remote_ifindex;
         struct list_head         list;
+        struct rcu_head          rcu;
 };
 
 /* Forwarding table entry */
@@ -496,6 +497,12 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan,
         return 0;
 }
 
+static void vxlan_fdb_free_rdst(struct rcu_head *head)
+{
+        struct vxlan_rdst *rd = container_of(head, struct vxlan_rdst, rcu);
+        kfree(rd);
+}
+
 static void vxlan_fdb_free(struct rcu_head *head)
 {
         struct vxlan_fdb *f = container_of(head, struct vxlan_fdb, rcu);
@@ -605,14 +612,43 @@ static int vxlan_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 {
         struct vxlan_dev *vxlan = netdev_priv(dev);
         struct vxlan_fdb *f;
-        int err = -ENOENT;
+        struct vxlan_rdst *rd = NULL;
+        __be32 ip;
+        __be16 port;
+        u32 vni, ifindex;
+        int err;
+
+        err = vxlan_fdb_parse(tb, vxlan, &ip, &port, &vni, &ifindex);
+        if (err)
+                return err;
+
+        err = -ENOENT;
 
         spin_lock_bh(&vxlan->hash_lock);
         f = vxlan_find_mac(vxlan, addr);
-        if (f) {
-                vxlan_fdb_destroy(vxlan, f);
-                err = 0;
+        if (!f)
+                goto out;
+
+        if (ip != htonl(INADDR_ANY)) {
+                rd = vxlan_fdb_find_rdst(f, ip, port, vni, ifindex);
+                if (!rd)
+                        goto out;
+        }
+
+        err = 0;
+
+        /* remove a destination if it's not the only one on the list,
+         * otherwise destroy the fdb entry
+         */
+        if (rd && !list_is_singular(&f->remotes)) {
+                list_del_rcu(&rd->list);
+                call_rcu(&rd->rcu, vxlan_fdb_free_rdst);
+                goto out;
         }
+
+        vxlan_fdb_destroy(vxlan, f);
+
+out:
         spin_unlock_bh(&vxlan->hash_lock);
 
         return err;