face: allow enabling/disabling congestion marking through config file

refs #4465

Change-Id: I888b83b1fdbe8e3fc36a902bf7af52147807d829
diff --git a/daemon/face/udp-channel.hpp b/daemon/face/udp-channel.hpp
index 471a971..4441370 100644
--- a/daemon/face/udp-channel.hpp
+++ b/daemon/face/udp-channel.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2017,  Regents of the University of California,
+ * Copyright (c) 2014-2018,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -48,7 +48,8 @@
    * The created socket is bound to \p localEndpoint.
    */
   UdpChannel(const udp::Endpoint& localEndpoint,
-             time::nanoseconds idleTimeout);
+             time::nanoseconds idleTimeout,
+             bool wantCongestionMarking);
 
   bool
   isListening() const override
@@ -120,6 +121,7 @@
   std::array<uint8_t, ndn::MAX_NDN_PACKET_SIZE> m_receiveBuffer;
   std::map<udp::Endpoint, shared_ptr<Face>> m_channelFaces;
   const time::nanoseconds m_idleFaceTimeout; ///< Timeout for automatic closure of idle on-demand faces
+  bool m_wantCongestionMarking;
 };
 
 } // namespace face