1 files changed, 49 insertions, 5 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 767f7af3bd40..570ad7aa7204 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -177,9 +177,14 @@ static inline struct hlist_head *vs_head(struct net *net, __be16 port)
 /* First remote destination for a forwarding entry.
  * Guaranteed to be non-NULL because remotes are never deleted.
  */
-static inline struct vxlan_rdst *first_remote(struct vxlan_fdb *fdb)
+static inline struct vxlan_rdst *first_remote_rcu(struct vxlan_fdb *fdb)
 {
-	return list_first_or_null_rcu(&fdb->remotes, struct vxlan_rdst, list);
+	return list_entry_rcu(fdb->remotes.next, struct vxlan_rdst, list);
+}
+
+static inline struct vxlan_rdst *first_remote_rtnl(struct vxlan_fdb *fdb)
+{
+	return list_first_entry(&fdb->remotes, struct vxlan_rdst, list);
 }
 
 /* Find VXLAN socket based on network namespace and UDP port */
@@ -297,7 +302,8 @@ static void vxlan_fdb_notify(struct vxlan_dev *vxlan,
 	if (skb == NULL)
 		goto errout;
 
-	err = vxlan_fdb_info(skb, vxlan, fdb, 0, 0, type, 0, first_remote(fdb));
+	err = vxlan_fdb_info(skb, vxlan, fdb, 0, 0, type, 0,
+			     first_remote_rtnl(fdb));
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in vxlan_nlmsg_size() */
 		WARN_ON(err == -EMSGSIZE);
@@ -408,6 +414,26 @@ static struct vxlan_rdst *vxlan_fdb_find_rdst(struct vxlan_fdb *f,
 	return NULL;
 }
 
+/* Replace destination of unicast mac */
+static int vxlan_fdb_replace(struct vxlan_fdb *f,
+			    __be32 ip, __be16 port, __u32 vni, __u32 ifindex)
+{
+	struct vxlan_rdst *rd;
+
+	rd = vxlan_fdb_find_rdst(f, ip, port, vni, ifindex);
+	if (rd)
+		return 0;
+
+	rd = list_first_entry_or_null(&f->remotes, struct vxlan_rdst, list);
+	if (!rd)
+		return 0;
+	rd->remote_ip = ip;
+	rd->remote_port = port;
+	rd->remote_vni = vni;
+	rd->remote_ifindex = ifindex;
+	return 1;
+}
+
 /* Add/update destinations for multicast */
 static int vxlan_fdb_append(struct vxlan_fdb *f,
 			    __be32 ip, __be16 port, __u32 vni, __u32 ifindex)
@@ -458,6 +484,19 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan,
 			f->updated = jiffies;
 			notify = 1;
 		}
+		if ((flags & NLM_F_REPLACE)) {
+			/* Only change unicasts */
+			if (!(is_multicast_ether_addr(f->eth_addr) ||
+			     is_zero_ether_addr(f->eth_addr))) {
+				int rc = vxlan_fdb_replace(f, ip, port, vni,
+							   ifindex);
+
+				if (rc < 0)
+					return rc;
+				notify |= rc;
+			} else
+				return -EOPNOTSUPP;
+		}
 		if ((flags & NLM_F_APPEND) &&
 		    (is_multicast_ether_addr(f->eth_addr) ||
 		     is_zero_ether_addr(f->eth_addr))) {
@@ -474,6 +513,11 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan,
 		if (vxlan->addrmax && vxlan->addrcnt >= vxlan->addrmax)
 			return -ENOSPC;
 
+		/* Disallow replace to add a multicast entry */
+		if ((flags & NLM_F_REPLACE) &&
+		    (is_multicast_ether_addr(mac) || is_zero_ether_addr(mac)))
+			return -EOPNOTSUPP;
+
 		netdev_dbg(vxlan->dev, "add %pM -> %pI4\n", mac, &ip);
 		f = kmalloc(sizeof(*f), GFP_ATOMIC);
 		if (!f)
@@ -702,7 +746,7 @@ static bool vxlan_snoop(struct net_device *dev,
 
 	f = vxlan_find_mac(vxlan, src_mac);
 	if (likely(f)) {
-		struct vxlan_rdst *rdst = first_remote(f);
+		struct vxlan_rdst *rdst = first_remote_rcu(f);
 
 		if (likely(rdst->remote_ip == src_ip))
 			return false;
@@ -967,7 +1011,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb)
 		}
 
 		f = vxlan_find_mac(vxlan, n->ha);
-		if (f && first_remote(f)->remote_ip == htonl(INADDR_ANY)) {
+		if (f && first_remote_rcu(f)->remote_ip == htonl(INADDR_ANY)) {
 			/* bridge-local neighbor */
 			neigh_release(n);
 			goto out;