daemon/face/udp-factory.cpp - ndnSIM/NFD - Gitiles

 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
  * Copyright (c) 2014-2015,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
  *                           Washington University in St. Louis,
  *                           Beijing Institute of Technology,
  *                           The University of Memphis.
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
  *
  * NFD is free software: you can redistribute it and/or modify it under the terms
  * of the GNU General Public License as published by the Free Software Foundation,
  * either version 3 of the License, or (at your option) any later version.
  *
  * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  * PURPOSE.  See the GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include "udp-factory.hpp"
 #include "core/global-io.hpp"
 #include "core/network-interface.hpp"

 #ifdef __linux__
 #include <cerrno>       // for errno
 #include <cstring>      // for std::strerror()
 #include <sys/socket.h> // for setsockopt()
 #endif

 namespace nfd {

 using namespace boost::asio;

 NFD_LOG_INIT("UdpFactory");

 static const boost::asio::ip::address_v4 ALL_V4_ENDPOINT(
   boost::asio::ip::address_v4::from_string("0.0.0.0"));

 static const boost::asio::ip::address_v6 ALL_V6_ENDPOINT(
   boost::asio::ip::address_v6::from_string("::"));

 UdpFactory::UdpFactory(const std::string& defaultPort/* = "6363"*/)
   : m_defaultPort(defaultPort)
 {
 }

 void
 UdpFactory::prohibitEndpoint(const udp::Endpoint& endpoint)
 {
   using namespace boost::asio::ip;

   const address& address = endpoint.address();

   if (address.is_v4() && address == ALL_V4_ENDPOINT)
     {
       prohibitAllIpv4Endpoints(endpoint.port());
     }
   else if (endpoint.address().is_v6() && address == ALL_V6_ENDPOINT)
     {
       prohibitAllIpv6Endpoints(endpoint.port());
     }

   NFD_LOG_TRACE("prohibiting UDP " << endpoint);

   m_prohibitedEndpoints.insert(endpoint);
 }

 void
 UdpFactory::prohibitAllIpv4Endpoints(const uint16_t port)
 {
   using namespace boost::asio::ip;

   for (const NetworkInterfaceInfo& nic : listNetworkInterfaces()) {
     for (const address_v4& addr : nic.ipv4Addresses) {
       if (addr != ALL_V4_ENDPOINT) {
         prohibitEndpoint(udp::Endpoint(addr, port));
       }
     }

     if (nic.isBroadcastCapable() && nic.broadcastAddress != ALL_V4_ENDPOINT)
     {
       NFD_LOG_TRACE("prohibiting broadcast address: " << nic.broadcastAddress.to_string());
       prohibitEndpoint(udp::Endpoint(nic.broadcastAddress, port));
     }
   }

   prohibitEndpoint(udp::Endpoint(address::from_string("255.255.255.255"), port));
 }

 void
 UdpFactory::prohibitAllIpv6Endpoints(const uint16_t port)
 {
   using namespace boost::asio::ip;

   for (const NetworkInterfaceInfo& nic : listNetworkInterfaces()) {
     for (const address_v6& addr : nic.ipv6Addresses) {
       if (addr != ALL_V6_ENDPOINT) {
         prohibitEndpoint(udp::Endpoint(addr, port));
       }
     }
   }
 }

 shared_ptr<UdpChannel>
 UdpFactory::createChannel(const udp::Endpoint& endpoint,
                           const time::seconds& timeout)
 {
   NFD_LOG_DEBUG("Creating unicast channel " << endpoint);

   shared_ptr<UdpChannel> channel = findChannel(endpoint);
   if (static_cast<bool>(channel))
     return channel;

   //checking if the endpoint is already in use for multicast face
   shared_ptr<MulticastUdpFace> multicast = findMulticastFace(endpoint);
   if (static_cast<bool>(multicast))
     BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP unicast channel, local "
                                 "endpoint is already allocated for a UDP multicast face"));

   if (endpoint.address().is_multicast()) {
     BOOST_THROW_EXCEPTION(Error("This method is only for unicast channel. The provided "
                                 "endpoint is multicast. Use createMulticastFace to "
                                 "create a multicast face"));
   }

   channel = make_shared<UdpChannel>(endpoint, timeout);
   m_channels[endpoint] = channel;
   prohibitEndpoint(endpoint);

   return channel;
 }

 shared_ptr<UdpChannel>
 UdpFactory::createChannel(const std::string& localIp,
                           const std::string& localPort,
                           const time::seconds& timeout)
 {
   using namespace boost::asio::ip;
   udp::Endpoint endpoint(address::from_string(localIp), boost::lexical_cast<uint16_t>(localPort));
   return createChannel(endpoint, timeout);
 }

 shared_ptr<MulticastUdpFace>
 UdpFactory::createMulticastFace(const udp::Endpoint& localEndpoint,
                                 const udp::Endpoint& multicastEndpoint,
                                 const std::string& networkInterfaceName/* = ""*/)
 {
   // checking if the local and multicast endpoints are already in use for a multicast face
   shared_ptr<MulticastUdpFace> face = findMulticastFace(localEndpoint);
   if (static_cast<bool>(face)) {
     if (face->getMulticastGroup() == multicastEndpoint)
       return face;
     else
       BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, local "
                                   "endpoint is already allocated for a UDP multicast face "
                                   "on a different multicast group"));
   }

   // checking if the local endpoint is already in use for a unicast channel
   shared_ptr<UdpChannel> unicast = findChannel(localEndpoint);
   if (static_cast<bool>(unicast)) {
     BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, local "
                                 "endpoint is already allocated for a UDP unicast channel"));
   }

   if (m_prohibitedEndpoints.find(multicastEndpoint) != m_prohibitedEndpoints.end()) {
     BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, "
                                 "remote endpoint is owned by this NFD instance"));
   }

   if (localEndpoint.address().is_v6() || multicastEndpoint.address().is_v6()) {
     BOOST_THROW_EXCEPTION(Error("IPv6 multicast is not supported yet. Please provide an IPv4 "
                                 "address"));
   }

   if (localEndpoint.port() != multicastEndpoint.port()) {
     BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, "
                                 "both endpoints should have the same port number. "));
   }

   if (!multicastEndpoint.address().is_multicast()) {
     BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, "
                                 "the multicast group given as input is not a multicast address"));
   }

   ip::udp::socket receiveSocket(getGlobalIoService());
   receiveSocket.open(multicastEndpoint.protocol());
   receiveSocket.set_option(ip::udp::socket::reuse_address(true));
   receiveSocket.bind(multicastEndpoint);

   ip::udp::socket sendSocket(getGlobalIoService());
   sendSocket.open(multicastEndpoint.protocol());
   sendSocket.set_option(ip::udp::socket::reuse_address(true));
   sendSocket.set_option(ip::multicast::enable_loopback(false));
   sendSocket.bind(udp::Endpoint(ip::address_v4::any(), multicastEndpoint.port()));
   if (localEndpoint.address() != ALL_V4_ENDPOINT)
     sendSocket.set_option(ip::multicast::outbound_interface(localEndpoint.address().to_v4()));

   sendSocket.set_option(ip::multicast::join_group(multicastEndpoint.address().to_v4(),
                                                   localEndpoint.address().to_v4()));
   receiveSocket.set_option(ip::multicast::join_group(multicastEndpoint.address().to_v4(),
                                                      localEndpoint.address().to_v4()));

 #ifdef __linux__
   /*
    * On Linux, if there is more than one MulticastUdpFace for the same multicast
    * group but they are bound to different network interfaces, the socket needs
    * to be bound to the specific interface using SO_BINDTODEVICE, otherwise the
    * face will receive all packets sent to the other interfaces as well.
    * This happens only on Linux. On OS X, the ip::multicast::join_group option
    * is enough to get the desired behaviour.
    */
   if (!networkInterfaceName.empty()) {
     if (::setsockopt(receiveSocket.native_handle(), SOL_SOCKET, SO_BINDTODEVICE,
                      networkInterfaceName.c_str(), networkInterfaceName.size() + 1) < 0) {
       BOOST_THROW_EXCEPTION(Error("Cannot bind multicast face to " + networkInterfaceName +
                                   ": " + std::strerror(errno)));
     }
   }
 #endif

   face = make_shared<MulticastUdpFace>(multicastEndpoint, FaceUri(localEndpoint),
                                        std::move(receiveSocket), std::move(sendSocket));

   face->onFail.connectSingleShot([this, localEndpoint] (const std::string& reason) {
     m_multicastFaces.erase(localEndpoint);
   });
   m_multicastFaces[localEndpoint] = face;

   return face;
 }

 shared_ptr<MulticastUdpFace>
 UdpFactory::createMulticastFace(const std::string& localIp,
                                 const std::string& multicastIp,
                                 const std::string& multicastPort,
                                 const std::string& networkInterfaceName/* = ""*/)
 {
   udp::Endpoint localEndpoint(ip::address::from_string(localIp),
                               boost::lexical_cast<uint16_t>(multicastPort));
   udp::Endpoint multicastEndpoint(ip::address::from_string(multicastIp),
                                   boost::lexical_cast<uint16_t>(multicastPort));
   return createMulticastFace(localEndpoint, multicastEndpoint, networkInterfaceName);
 }

 void
 UdpFactory::createFace(const FaceUri& uri,
                        ndn::nfd::FacePersistency persistency,
                        const FaceCreatedCallback& onCreated,
                        const FaceConnectFailedCallback& onConnectFailed)
 {
   if (persistency != ndn::nfd::FACE_PERSISTENCY_PERSISTENT) {
     BOOST_THROW_EXCEPTION(Error("UdpFactory only supports persistent face"));
   }

   BOOST_ASSERT(uri.isCanonical());

   boost::asio::ip::address ipAddress = boost::asio::ip::address::from_string(uri.getHost());
   udp::Endpoint endpoint(ipAddress, boost::lexical_cast<uint16_t>(uri.getPort()));

   if (endpoint.address().is_multicast()) {
     onConnectFailed("The provided address is multicast. Please use createMulticastFace method");
     return;
   }

   if (m_prohibitedEndpoints.find(endpoint) != m_prohibitedEndpoints.end()) {
     onConnectFailed("Requested endpoint is prohibited "
                     "(reserved by this NFD or disallowed by face management protocol)");
     return;
   }

   // very simple logic for now
   for (ChannelMap::iterator channel = m_channels.begin();
        channel != m_channels.end();
        ++channel)
   {
     if ((channel->first.address().is_v4() && endpoint.address().is_v4()) ||
         (channel->first.address().is_v6() && endpoint.address().is_v6()))
     {
       channel->second->connect(endpoint, onCreated, onConnectFailed);
       return;
     }
   }

   onConnectFailed("No channels available to connect to " +
                   boost::lexical_cast<std::string>(endpoint));
 }

 shared_ptr<UdpChannel>
 UdpFactory::findChannel(const udp::Endpoint& localEndpoint)
 {
   ChannelMap::iterator i = m_channels.find(localEndpoint);
   if (i != m_channels.end())
     return i->second;
   else
     return shared_ptr<UdpChannel>();
 }

 shared_ptr<MulticastUdpFace>
 UdpFactory::findMulticastFace(const udp::Endpoint& localEndpoint)
 {
   MulticastFaceMap::iterator i = m_multicastFaces.find(localEndpoint);
   if (i != m_multicastFaces.end())
     return i->second;
   else
     return shared_ptr<MulticastUdpFace>();
 }

 std::list<shared_ptr<const Channel>>
 UdpFactory::getChannels() const
 {
   std::list<shared_ptr<const Channel>> channels;
   for (ChannelMap::const_iterator i = m_channels.begin(); i != m_channels.end(); ++i)
     {
       channels.push_back(i->second);
     }

   return channels;
 }

 } // namespace nfd
	/* -- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -- */
	/**
	* Copyright (c) 2014-2015, Regents of the University of California,
	* Arizona Board of Regents,
	* Colorado State University,
	* University Pierre & Marie Curie, Sorbonne University,
	* Washington University in St. Louis,
	* Beijing Institute of Technology,
	* The University of Memphis.
	*
	* This file is part of NFD (Named Data Networking Forwarding Daemon).
	* See AUTHORS.md for complete list of NFD authors and contributors.
	*
	* NFD is free software: you can redistribute it and/or modify it under the terms
	* of the GNU General Public License as published by the Free Software Foundation,
	* either version 3 of the License, or (at your option) any later version.
	*
	* NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
	* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
	* PURPOSE. See the GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include "udp-factory.hpp"
	#include "core/global-io.hpp"
	#include "core/network-interface.hpp"

	#ifdef __linux__
	#include <cerrno> // for errno
	#include <cstring> // for std::strerror()
	#include <sys/socket.h> // for setsockopt()
	#endif

	namespace nfd {

	using namespace boost::asio;

	NFD_LOG_INIT("UdpFactory");

	static const boost::asio::ip::address_v4 ALL_V4_ENDPOINT(
	boost::asio::ip::address_v4::from_string("0.0.0.0"));

	static const boost::asio::ip::address_v6 ALL_V6_ENDPOINT(
	boost::asio::ip::address_v6::from_string("::"));

	UdpFactory::UdpFactory(const std::string& defaultPort/* = "6363"*/)
	: m_defaultPort(defaultPort)
	{
	}

	void
	UdpFactory::prohibitEndpoint(const udp::Endpoint& endpoint)
	{
	using namespace boost::asio::ip;

	const address& address = endpoint.address();

	if (address.is_v4() && address == ALL_V4_ENDPOINT)
	{
	prohibitAllIpv4Endpoints(endpoint.port());
	}
	else if (endpoint.address().is_v6() && address == ALL_V6_ENDPOINT)
	{
	prohibitAllIpv6Endpoints(endpoint.port());
	}

	NFD_LOG_TRACE("prohibiting UDP " << endpoint);

	m_prohibitedEndpoints.insert(endpoint);
	}

	void
	UdpFactory::prohibitAllIpv4Endpoints(const uint16_t port)
	{
	using namespace boost::asio::ip;

	for (const NetworkInterfaceInfo& nic : listNetworkInterfaces()) {
	for (const address_v4& addr : nic.ipv4Addresses) {
	if (addr != ALL_V4_ENDPOINT) {
	prohibitEndpoint(udp::Endpoint(addr, port));
	}
	}

	if (nic.isBroadcastCapable() && nic.broadcastAddress != ALL_V4_ENDPOINT)
	{
	NFD_LOG_TRACE("prohibiting broadcast address: " << nic.broadcastAddress.to_string());
	prohibitEndpoint(udp::Endpoint(nic.broadcastAddress, port));
	}
	}

	prohibitEndpoint(udp::Endpoint(address::from_string("255.255.255.255"), port));
	}

	void
	UdpFactory::prohibitAllIpv6Endpoints(const uint16_t port)
	{
	using namespace boost::asio::ip;

	for (const NetworkInterfaceInfo& nic : listNetworkInterfaces()) {
	for (const address_v6& addr : nic.ipv6Addresses) {
	if (addr != ALL_V6_ENDPOINT) {
	prohibitEndpoint(udp::Endpoint(addr, port));
	}
	}
	}
	}

	shared_ptr<UdpChannel>
	UdpFactory::createChannel(const udp::Endpoint& endpoint,
	const time::seconds& timeout)
	{
	NFD_LOG_DEBUG("Creating unicast channel " << endpoint);

	shared_ptr<UdpChannel> channel = findChannel(endpoint);
	if (static_cast<bool>(channel))
	return channel;

	//checking if the endpoint is already in use for multicast face
	shared_ptr<MulticastUdpFace> multicast = findMulticastFace(endpoint);
	if (static_cast<bool>(multicast))
	BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP unicast channel, local "
	"endpoint is already allocated for a UDP multicast face"));

	if (endpoint.address().is_multicast()) {
	BOOST_THROW_EXCEPTION(Error("This method is only for unicast channel. The provided "
	"endpoint is multicast. Use createMulticastFace to "
	"create a multicast face"));
	}

	channel = make_shared<UdpChannel>(endpoint, timeout);
	m_channels[endpoint] = channel;
	prohibitEndpoint(endpoint);

	return channel;
	}

	shared_ptr<UdpChannel>
	UdpFactory::createChannel(const std::string& localIp,
	const std::string& localPort,
	const time::seconds& timeout)
	{
	using namespace boost::asio::ip;
	udp::Endpoint endpoint(address::from_string(localIp), boost::lexical_cast<uint16_t>(localPort));
	return createChannel(endpoint, timeout);
	}

	shared_ptr<MulticastUdpFace>
	UdpFactory::createMulticastFace(const udp::Endpoint& localEndpoint,
	const udp::Endpoint& multicastEndpoint,
	const std::string& networkInterfaceName/* = ""*/)
	{
	// checking if the local and multicast endpoints are already in use for a multicast face
	shared_ptr<MulticastUdpFace> face = findMulticastFace(localEndpoint);
	if (static_cast<bool>(face)) {
	if (face->getMulticastGroup() == multicastEndpoint)
	return face;
	else
	BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, local "
	"endpoint is already allocated for a UDP multicast face "
	"on a different multicast group"));
	}

	// checking if the local endpoint is already in use for a unicast channel
	shared_ptr<UdpChannel> unicast = findChannel(localEndpoint);
	if (static_cast<bool>(unicast)) {
	BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, local "
	"endpoint is already allocated for a UDP unicast channel"));
	}

	if (m_prohibitedEndpoints.find(multicastEndpoint) != m_prohibitedEndpoints.end()) {
	BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, "
	"remote endpoint is owned by this NFD instance"));
	}

	if (localEndpoint.address().is_v6() \|\| multicastEndpoint.address().is_v6()) {
	BOOST_THROW_EXCEPTION(Error("IPv6 multicast is not supported yet. Please provide an IPv4 "
	"address"));
	}

	if (localEndpoint.port() != multicastEndpoint.port()) {
	BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, "
	"both endpoints should have the same port number. "));
	}

	if (!multicastEndpoint.address().is_multicast()) {
	BOOST_THROW_EXCEPTION(Error("Cannot create the requested UDP multicast face, "
	"the multicast group given as input is not a multicast address"));
	}

	ip::udp::socket receiveSocket(getGlobalIoService());
	receiveSocket.open(multicastEndpoint.protocol());
	receiveSocket.set_option(ip::udp::socket::reuse_address(true));
	receiveSocket.bind(multicastEndpoint);

	ip::udp::socket sendSocket(getGlobalIoService());
	sendSocket.open(multicastEndpoint.protocol());
	sendSocket.set_option(ip::udp::socket::reuse_address(true));
	sendSocket.set_option(ip::multicast::enable_loopback(false));
	sendSocket.bind(udp::Endpoint(ip::address_v4::any(), multicastEndpoint.port()));
	if (localEndpoint.address() != ALL_V4_ENDPOINT)
	sendSocket.set_option(ip::multicast::outbound_interface(localEndpoint.address().to_v4()));

	sendSocket.set_option(ip::multicast::join_group(multicastEndpoint.address().to_v4(),
	localEndpoint.address().to_v4()));
	receiveSocket.set_option(ip::multicast::join_group(multicastEndpoint.address().to_v4(),
	localEndpoint.address().to_v4()));

	#ifdef __linux__
	/*
	* On Linux, if there is more than one MulticastUdpFace for the same multicast
	* group but they are bound to different network interfaces, the socket needs
	* to be bound to the specific interface using SO_BINDTODEVICE, otherwise the
	* face will receive all packets sent to the other interfaces as well.
	* This happens only on Linux. On OS X, the ip::multicast::join_group option
	* is enough to get the desired behaviour.
	*/
	if (!networkInterfaceName.empty()) {
	if (::setsockopt(receiveSocket.native_handle(), SOL_SOCKET, SO_BINDTODEVICE,
	networkInterfaceName.c_str(), networkInterfaceName.size() + 1) < 0) {
	BOOST_THROW_EXCEPTION(Error("Cannot bind multicast face to " + networkInterfaceName +
	": " + std::strerror(errno)));
	}
	}
	#endif

	face = make_shared<MulticastUdpFace>(multicastEndpoint, FaceUri(localEndpoint),
	std::move(receiveSocket), std::move(sendSocket));

	face->onFail.connectSingleShot([this, localEndpoint] (const std::string& reason) {
	m_multicastFaces.erase(localEndpoint);
	});
	m_multicastFaces[localEndpoint] = face;

	return face;
	}

	shared_ptr<MulticastUdpFace>
	UdpFactory::createMulticastFace(const std::string& localIp,
	const std::string& multicastIp,
	const std::string& multicastPort,
	const std::string& networkInterfaceName/* = ""*/)
	{
	udp::Endpoint localEndpoint(ip::address::from_string(localIp),
	boost::lexical_cast<uint16_t>(multicastPort));
	udp::Endpoint multicastEndpoint(ip::address::from_string(multicastIp),
	boost::lexical_cast<uint16_t>(multicastPort));
	return createMulticastFace(localEndpoint, multicastEndpoint, networkInterfaceName);
	}

	void
	UdpFactory::createFace(const FaceUri& uri,
	ndn::nfd::FacePersistency persistency,
	const FaceCreatedCallback& onCreated,
	const FaceConnectFailedCallback& onConnectFailed)
	{
	if (persistency != ndn::nfd::FACE_PERSISTENCY_PERSISTENT) {
	BOOST_THROW_EXCEPTION(Error("UdpFactory only supports persistent face"));
	}

	BOOST_ASSERT(uri.isCanonical());

	boost::asio::ip::address ipAddress = boost::asio::ip::address::from_string(uri.getHost());
	udp::Endpoint endpoint(ipAddress, boost::lexical_cast<uint16_t>(uri.getPort()));

	if (endpoint.address().is_multicast()) {
	onConnectFailed("The provided address is multicast. Please use createMulticastFace method");
	return;
	}

	if (m_prohibitedEndpoints.find(endpoint) != m_prohibitedEndpoints.end()) {
	onConnectFailed("Requested endpoint is prohibited "
	"(reserved by this NFD or disallowed by face management protocol)");
	return;
	}

	// very simple logic for now
	for (ChannelMap::iterator channel = m_channels.begin();
	channel != m_channels.end();
	++channel)
	{
	if ((channel->first.address().is_v4() && endpoint.address().is_v4()) \|\|
	(channel->first.address().is_v6() && endpoint.address().is_v6()))
	{
	channel->second->connect(endpoint, onCreated, onConnectFailed);
	return;
	}
	}

	onConnectFailed("No channels available to connect to " +
	boost::lexical_cast<std::string>(endpoint));
	}

	shared_ptr<UdpChannel>
	UdpFactory::findChannel(const udp::Endpoint& localEndpoint)
	{
	ChannelMap::iterator i = m_channels.find(localEndpoint);
	if (i != m_channels.end())
	return i->second;
	else
	return shared_ptr<UdpChannel>();
	}

	shared_ptr<MulticastUdpFace>
	UdpFactory::findMulticastFace(const udp::Endpoint& localEndpoint)
	{
	MulticastFaceMap::iterator i = m_multicastFaces.find(localEndpoint);
	if (i != m_multicastFaces.end())
	return i->second;
	else
	return shared_ptr<MulticastUdpFace>();
	}

	std::list<shared_ptr<const Channel>>
	UdpFactory::getChannels() const
	{
	std::list<shared_ptr<const Channel>> channels;
	for (ChannelMap::const_iterator i = m_channels.begin(); i != m_channels.end(); ++i)
	{
	channels.push_back(i->second);
	}

	return channels;
	}

	} // namespace nfd