diff --git a/vendor/go.etcd.io/etcd/etcdserver/server_access_control.go b/vendor/go.etcd.io/etcd/etcdserver/server_access_control.go
new file mode 100644
index 0000000..09e2255
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/server_access_control.go
@@ -0,0 +1,65 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import "sync"
+
+// AccessController controls etcd server HTTP request access.
+type AccessController struct {
+	corsMu          sync.RWMutex
+	CORS            map[string]struct{}
+	hostWhitelistMu sync.RWMutex
+	HostWhitelist   map[string]struct{}
+}
+
+// NewAccessController returns a new "AccessController" with default "*" values.
+func NewAccessController() *AccessController {
+	return &AccessController{
+		CORS:          map[string]struct{}{"*": {}},
+		HostWhitelist: map[string]struct{}{"*": {}},
+	}
+}
+
+// OriginAllowed determines whether the server will allow a given CORS origin.
+// If CORS is empty, allow all.
+func (ac *AccessController) OriginAllowed(origin string) bool {
+	ac.corsMu.RLock()
+	defer ac.corsMu.RUnlock()
+	if len(ac.CORS) == 0 { // allow all
+		return true
+	}
+	_, ok := ac.CORS["*"]
+	if ok {
+		return true
+	}
+	_, ok = ac.CORS[origin]
+	return ok
+}
+
+// IsHostWhitelisted returns true if the host is whitelisted.
+// If whitelist is empty, allow all.
+func (ac *AccessController) IsHostWhitelisted(host string) bool {
+	ac.hostWhitelistMu.RLock()
+	defer ac.hostWhitelistMu.RUnlock()
+	if len(ac.HostWhitelist) == 0 { // allow all
+		return true
+	}
+	_, ok := ac.HostWhitelist["*"]
+	if ok {
+		return true
+	}
+	_, ok = ac.HostWhitelist[host]
+	return ok
+}