Added UdpTransport
diff --git a/ndn-cpp/c/errors.c b/ndn-cpp/c/errors.c
index 89f30a1..af32008 100644
--- a/ndn-cpp/c/errors.c
+++ b/ndn-cpp/c/errors.c
@@ -62,6 +62,16 @@
     return      "TcpTransport error in send";
   case NDN_ERROR_TcpTransport_error_in_recv:
     return      "TcpTransport error in recv";
+  case NDN_ERROR_UdpTransport_error_in_getaddrinfo:
+    return      "UdpTransport error in getaddrinfo";
+  case NDN_ERROR_UdpTransport_cannot_connect_to_socket:
+    return      "UdpTransport cannot connect to socket";
+  case NDN_ERROR_UdpTransport_socket_is_not_open:
+    return      "UdpTransport socket is not open";
+  case NDN_ERROR_UdpTransport_error_in_send:
+    return      "UdpTransport error in send";
+  case NDN_ERROR_UdpTransport_error_in_recv:
+    return      "UdpTransport error in recv";
   default:
     return "unrecognized ndn_Error code";  
   }
diff --git a/ndn-cpp/c/errors.h b/ndn-cpp/c/errors.h
index 56f509c..f574b6a 100644
--- a/ndn-cpp/c/errors.h
+++ b/ndn-cpp/c/errors.h
@@ -38,7 +38,12 @@
   NDN_ERROR_TcpTransport_cannot_connect_to_socket,
   NDN_ERROR_TcpTransport_socket_is_not_open,
   NDN_ERROR_TcpTransport_error_in_send,
-  NDN_ERROR_TcpTransport_error_in_recv
+  NDN_ERROR_TcpTransport_error_in_recv,
+  NDN_ERROR_UdpTransport_error_in_getaddrinfo,
+  NDN_ERROR_UdpTransport_cannot_connect_to_socket,
+  NDN_ERROR_UdpTransport_socket_is_not_open,
+  NDN_ERROR_UdpTransport_error_in_send,
+  NDN_ERROR_UdpTransport_error_in_recv
 } ndn_Error;
   
 /**
diff --git a/ndn-cpp/c/transport/UdpTransport.h b/ndn-cpp/c/transport/UdpTransport.h
new file mode 100644
index 0000000..924e4a7
--- /dev/null
+++ b/ndn-cpp/c/transport/UdpTransport.h
@@ -0,0 +1,35 @@
+/**
+ * @author: Jeff Thompson
+ * See COPYING for copyright and distribution information.
+ */
+
+#ifndef NDN_UDPTRANSPORT_H
+#define	NDN_UDPTRANSPORT_H
+
+#include "../errors.h"
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+struct ndn_UdpTransport {
+  int socketDescriptor; /**< -1 if not connected */
+};
+  
+static inline void ndn_UdpTransport_init(struct ndn_UdpTransport *self)
+{
+  self->socketDescriptor = -1;
+}
+
+ndn_Error ndn_UdpTransport_connect(struct ndn_UdpTransport *self, char *host, unsigned short port);
+
+ndn_Error ndn_UdpTransport_send(struct ndn_UdpTransport *self, unsigned char *data, unsigned int dataLength);
+
+ndn_Error ndn_UdpTransport_receive
+  (struct ndn_UdpTransport *self, unsigned char *buffer, unsigned int bufferLength, unsigned int *nBytes);
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif
diff --git a/ndn-cpp/transport/UdpTransport.cpp b/ndn-cpp/transport/UdpTransport.cpp
new file mode 100644
index 0000000..ae0124f
--- /dev/null
+++ b/ndn-cpp/transport/UdpTransport.cpp
@@ -0,0 +1,54 @@
+/**
+ * @author: Jeff Thompson
+ * See COPYING for copyright and distribution information.
+ */
+
+#include <stdexcept>
+#include "../NDN.hpp"
+#include "../c/util/ndn_realloc.h"
+#include "UdpTransport.hpp"
+
+using namespace std;
+
+namespace ndn {
+
+void UdpTransport::connect(NDN &ndn)
+{
+  ndn_Error error;
+  if (error = ndn_UdpTransport_connect(&transport_, (char *)ndn.getHost(), ndn.getPort()))
+    throw std::runtime_error(ndn_getErrorString(error)); 
+
+  // TODO: This belongs in the socket listener.
+  const unsigned int initialLength = 1000;
+  // Automatically cast ndn_ to (struct ndn_ElementListener *)
+  ndn_BinaryXMLElementReader_init
+    (&elementReader_, &ndn, (unsigned char *)malloc(initialLength), initialLength, ndn_realloc);
+  
+  // TODO: Properly indicate connected status.
+  ndn_ = &ndn;
+}
+
+void UdpTransport::send(unsigned char *data, unsigned int dataLength)
+{
+  ndn_Error error;
+  if (error = ndn_UdpTransport_send(&transport_, data, dataLength))
+    throw std::runtime_error(ndn_getErrorString(error));  
+}
+
+void UdpTransport::tempReceive()
+{
+  try {   
+    ndn_Error error;
+    unsigned char buffer[8000];
+    unsigned int nBytes;
+    if (error = ndn_UdpTransport_receive(&transport_, buffer, sizeof(buffer), &nBytes))
+      throw std::runtime_error(ndn_getErrorString(error));  
+
+    ndn_BinaryXMLElementReader_onReceivedData(&elementReader_, buffer, nBytes);
+  } catch (...) {
+    // This function is called by the socket callback, so don't send an exception back to it.
+    // TODO: Log the exception?
+  }
+}
+
+}
diff --git a/ndn-cpp/transport/UdpTransport.hpp b/ndn-cpp/transport/UdpTransport.hpp
new file mode 100644
index 0000000..a24a4dc
--- /dev/null
+++ b/ndn-cpp/transport/UdpTransport.hpp
@@ -0,0 +1,42 @@
+/**
+ * @author: Jeff Thompson
+ * See COPYING for copyright and distribution information.
+ */
+
+#ifndef NDN_TCPTRANSPORT_HPP
+#define	NDN_TCPTRANSPORT_HPP
+
+#include "../c/transport/UdpTransport.h"
+#include "../c/encoding/BinaryXMLElementReader.h"
+#include "Transport.hpp"
+
+namespace ndn {
+  
+class UdpTransport : public Transport {
+public:
+  UdpTransport() 
+  {
+    ndn_UdpTransport_init(&transport_);
+    ndn_ = 0;
+  }
+  
+  /**
+   * 
+   * @param ndn Not a shared_ptr because we assume that it will remain valid during the life of this Transport object.
+   */
+  virtual void connect(NDN &ndn);
+  
+  virtual void send(unsigned char *data, unsigned int dataLength);
+
+  virtual void tempReceive();
+  
+private:
+  struct ndn_UdpTransport transport_;
+  NDN *ndn_;
+  // TODO: This belongs in the socket listener.
+  ndn_BinaryXMLElementReader elementReader_;
+};
+
+}
+
+#endif