diff --git a/connection_manager_interface.h b/connection_manager_interface.h
new file mode 100644
index 0000000..aa04946
--- /dev/null
+++ b/connection_manager_interface.h
@@ -0,0 +1,60 @@
+// Copyright 2015 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UPDATE_ENGINE_CONNECTION_MANAGER_INTERFACE_H_
+#define UPDATE_ENGINE_CONNECTION_MANAGER_INTERFACE_H_
+
+#include <base/macros.h>
+
+#include "update_engine/dbus_wrapper_interface.h"
+
+namespace chromeos_update_engine {
+
+enum class NetworkConnectionType {
+  kEthernet,
+  kWifi,
+  kWimax,
+  kBluetooth,
+  kCellular,
+  kUnknown
+};
+
+enum class NetworkTethering {
+  kNotDetected,
+  kSuspected,
+  kConfirmed,
+  kUnknown
+};
+
+// This class exposes a generic interface to the connection manager
+// (e.g FlimFlam, Shill, etc.) to consolidate all connection-related
+// logic in update_engine.
+class ConnectionManagerInterface {
+ public:
+  virtual ~ConnectionManagerInterface() = default;
+
+  // Populates |out_type| with the type of the network connection
+  // that we are currently connected and |out_tethering| with the estimate of
+  // whether that network is being tethered.
+  virtual bool GetConnectionProperties(
+      DBusWrapperInterface* dbus_iface,
+      NetworkConnectionType* out_type,
+      NetworkTethering* out_tethering) const = 0;
+
+  // Returns true if we're allowed to update the system when we're
+  // connected to the internet through the given network connection type and the
+  // given tethering state.
+  virtual bool IsUpdateAllowedOver(NetworkConnectionType type,
+                                   NetworkTethering tethering) const = 0;
+
+ protected:
+  ConnectionManagerInterface() = default;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ConnectionManagerInterface);
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_CONNECTION_MANAGER_INTERFACE_H_