recovery: Implement a volume manager

This is a copy of the pre-binderized vold which has been converted to
use direct calls instead of sockets and stripped down to only what is
needed to support recovery.

Change-Id: Ic82d929e052b5ba70ecf7b475e0a223d77d9687e
diff --git a/volume_manager/NetlinkManager.h b/volume_manager/NetlinkManager.h
new file mode 100644
index 0000000..c09ff06
--- /dev/null
+++ b/volume_manager/NetlinkManager.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * Copyright (C) 2019 The LineageOS Project
+ *
+ * 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.
+ */
+
+#ifndef _NETLINKMANAGER_H
+#define _NETLINKMANAGER_H
+
+#include <sysutils/NetlinkListener.h>
+#include <sysutils/SocketListener.h>
+
+class NetlinkHandler;
+
+class NetlinkManager {
+  private:
+    static NetlinkManager* sInstance;
+
+  private:
+    NetlinkHandler* mHandler;
+    int mSock;
+
+  public:
+    virtual ~NetlinkManager();
+
+    bool start();
+    void stop();
+
+    static NetlinkManager* Instance();
+
+  private:
+    NetlinkManager();
+};
+#endif