JUDPSocket.hh

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#ifndef __JNET__JUDPSOCKET__
#define __JNET__JUDPSOCKET__

#include "JLang/JException.hh"

#include "JSystem/JNetwork.hh"

#include "JNet/JSocket.hh"
#include "JNet/JHostname.hh"


/**
 * \author cpellegrino, mdejong
 */
namespace JNET {}
namespace JPP { using namespace JNET; }

namespace JNET {

  using JLANG::JSocketException;

  /**
   * UDP socket.
   */
  class JUDPSocket :
    public JSocket
  {
  public:
    
    using JSocket::read;

    /**
     * Default constructor.
     */
    JUDPSocket() :
      JSocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)
    {}

    
    /**
     * Constructor.
     * UDP socket for client.
     *
     * \param  hostname    host name of destination
     */
    JUDPSocket(const JHostname& hostname): 
      JSocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)
    {
      this->setReuseAddress(true);
      this->setIPnumber(JSYSTEM::getIPnumber(hostname.hostname));
      this->setPort(hostname.port);
    }


    /**
     * Constructor.
     * UDP socket for server.
     *
     * \param  port        port number of receiver
     */
    JUDPSocket(const int port): 
      JSocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)
    {
      this->setReuseAddress(true);
      this->setIPnumber();
      this->setPort(port);
      
      if (::bind(getFileDescriptor(), getSockaddr(), sizeof(sockaddr)) < 0) {
        THROW(JSocketException, "Bind socket failed at port " << port);
      }
    }


    /**
     * Read data from socket.
     *
     * \param  buffer       buffer
     * \param  length       number of bytes to read
     * \return              number of bytes actually read
     */
    int read(char* buffer, const int length)
    {
      // read also zero-length datagram, as opposed to method read.

      return ::recv(this->getFileDescriptor(),
                    buffer,
                    length,
                    0);
    }


    /**
     * Read data from socket.
     *
     * \param  buffer       buffer
     * \param  length       number of bytes to read
     * \param  udp          UDP socket
     * \return              number of bytes actually read
     */
    int read(char* buffer, const int length, JUDPSocket& udp)
    {
      socklen_t size = sizeof(sockaddr);

      udp.setFileDescriptor(this->getFileDescriptor());

      return ::recvfrom(this->getFileDescriptor(),
                        buffer,
                        length,
                        0,
                        udp.getSockaddr(),
                        &size);
    }


    /**
     * Write data to socket.
     *
     * \param  buffer       buffer
     * \param  length       number of bytes to write
     * \return              number of bytes actually written
     */
    virtual int write(const char* buffer, const int length) override
    {
      return ::sendto(this->getFileDescriptor(),
                      buffer,
                      length,
                      0,
                      this->getSockaddr(),
                      sizeof(sockaddr));
    }
  };
}

#endif