content: /*
   * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code 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
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.net;
  
  import java.io.FileDescriptor;
  import java.io.IOException;
  import java.io.InterruptedIOException;
  
  /**
   * Abstract datagram and multicast socket implementation base class.
   * @author Pavani Diwanji
   * @since  JDK1.1
   */
  
  public abstract class DatagramSocketImpl implements SocketOptions {
  
      /**
       * The local port number.
       */
      protected int localPort;
  
      /**
       * The file descriptor object.
       */
      protected FileDescriptor fd;
  
      int dataAvailable() {
          // default impl returns zero, which disables the calling
          // functionality
          return 0;
      }
  
      /**
       * The DatagramSocket or MulticastSocket
       * that owns this impl
       */
      DatagramSocket socket;
  
      void setDatagramSocket(DatagramSocket socket) {
          this.socket = socket;
      }
  
      DatagramSocket getDatagramSocket() {
          return socket;
      }
  
      /**
       * Creates a datagram socket.
       * @exception SocketException if there is an error in the
       * underlying protocol, such as a TCP error.
       */
      protected abstract void create() throws SocketException;
  
      /**
       * Binds a datagram socket to a local port and address.
       * @param lport the local port
       * @param laddr the local address
       * @exception SocketException if there is an error in the
       * underlying protocol, such as a TCP error.
       */
      protected abstract void bind(int lport, InetAddress laddr) throws SocketException;
  
      /**
       * Sends a datagram packet. The packet contains the data and the
       * destination address to send the packet to.
       * @param p the packet to be sent.
       * @exception IOException if an I/O exception occurs while sending the
       * datagram packet.
       * @exception  PortUnreachableException may be thrown if the socket is connected
       * to a currently unreachable destination. Note, there is no guarantee that
       * the exception will be thrown.
       */
      protected abstract void send(DatagramPacket p) throws IOException;
  
      /**
       * Connects a datagram socket to a remote destination. This associates the remote
       * address with the local socket so that datagrams may only be sent to this destination
       * and received from this destination. This may be overridden to call a native
       * system connect.
       *
       * <p>If the remote destination to which the socket is connected does not
       * exist, or is otherwise unreachable, and if an ICMP destination unreachable
       * packet has been received for that address, then a subsequent call to
       * send or receive may throw a PortUnreachableException.
       * Note, there is no guarantee that the exception will be thrown.
       * @param address the remote InetAddress to connect to
       * @param port the remote port number
       * @exception   SocketException may be thrown if the socket cannot be
       * connected to the remote destination
       * @since 1.4
       */
      protected void connect(InetAddress address, int port) throws SocketException {}
  
      /**
       * Disconnects a datagram socket from its remote destination.
       * @since 1.4
       */
      protected void disconnect() {}
  
      /**
       * Peek at the packet to see who it is from. Updates the specified {@code InetAddress}
       * to the address which the packet came from.
       * @param i an InetAddress object
       * @return the port number which the packet came from.
       * @exception IOException if an I/O exception occurs
       * @exception  PortUnreachableException may be thrown if the socket is connected
       *       to a currently unreachable destination. Note, there is no guarantee that the
       *       exception will be thrown.
       */
      protected abstract int peek(InetAddress i) throws IOException;
  
      /**
       * Peek at the packet to see who it is from. The data is copied into the specified
       * {@code DatagramPacket}. The data is returned,
       * but not consumed, so that a subsequent peekData/receive operation
       * will see the same data.
       * @param p the Packet Received.
       * @return the port number which the packet came from.
       * @exception IOException if an I/O exception occurs
       * @exception  PortUnreachableException may be thrown if the socket is connected
       *       to a currently unreachable destination. Note, there is no guarantee that the
       *       exception will be thrown.
       * @since 1.4
       */
      protected abstract int peekData(DatagramPacket p) throws IOException;
      /**
       * Receive the datagram packet.
       * @param p the Packet Received.
       * @exception IOException if an I/O exception occurs
       * while receiving the datagram packet.
       * @exception  PortUnreachableException may be thrown if the socket is connected
       *       to a currently unreachable destination. Note, there is no guarantee that the
       *       exception will be thrown.
       */
      protected abstract void receive(DatagramPacket p) throws IOException;
  
      /**
       * Set the TTL (time-to-live) option.
       * @param ttl a byte specifying the TTL value
       *
       * @deprecated use setTimeToLive instead.
       * @exception IOException if an I/O exception occurs while setting
       * the time-to-live option.
       * @see #getTTL()
       */
      @Deprecated
      protected abstract void setTTL(byte ttl) throws IOException;
  
      /**
       * Retrieve the TTL (time-to-live) option.
       *
       * @exception IOException if an I/O exception occurs
       * while retrieving the time-to-live option
       * @deprecated use getTimeToLive instead.
       * @return a byte representing the TTL value
       * @see #setTTL(byte)
       */
      @Deprecated
      protected abstract byte getTTL() throws IOException;
  
      /**
       * Set the TTL (time-to-live) option.
       * @param ttl an {@code int} specifying the time-to-live value
       * @exception IOException if an I/O exception occurs
       * while setting the time-to-live option.
       * @see #getTimeToLive()
       */
      protected abstract void setTimeToLive(int ttl) throws IOException;
  
      /**
       * Retrieve the TTL (time-to-live) option.
       * @exception IOException if an I/O exception occurs
       * while retrieving the time-to-live option
       * @return an {@code int} representing the time-to-live value
       * @see #setTimeToLive(int)
       */
      protected abstract int getTimeToLive() throws IOException;
  
      /**
       * Join the multicast group.
       * @param inetaddr multicast address to join.
       * @exception IOException if an I/O exception occurs
       * while joining the multicast group.
       */
      protected abstract void join(InetAddress inetaddr) throws IOException;
  
      /**
       * Leave the multicast group.
       * @param inetaddr multicast address to leave.
       * @exception IOException if an I/O exception occurs
       * while leaving the multicast group.
       */
      protected abstract void leave(InetAddress inetaddr) throws IOException;
  
      /**
       * Join the multicast group.
       * @param mcastaddr address to join.
       * @param netIf specifies the local interface to receive multicast
       *        datagram packets
       * @throws IOException if an I/O exception occurs while joining
       * the multicast group
       * @since 1.4
       */
      protected abstract void joinGroup(SocketAddress mcastaddr,
                                        NetworkInterface netIf)
          throws IOException;
  
      /**
       * Leave the multicast group.
       * @param mcastaddr address to leave.
       * @param netIf specified the local interface to leave the group at
       * @throws IOException if an I/O exception occurs while leaving
       * the multicast group
       * @since 1.4
       */
      protected abstract void leaveGroup(SocketAddress mcastaddr,
                                         NetworkInterface netIf)
          throws IOException;
  
      /**
       * Close the socket.
       */
      protected abstract void close();
  
      /**
       * Gets the local port.
       * @return an {@code int} representing the local port value
       */
      protected int getLocalPort() {
          return localPort;
      }
  
      <T> void setOption(SocketOption<T> name, T value) throws IOException {
          if (name == StandardSocketOptions.SO_SNDBUF) {
              setOption(SocketOptions.SO_SNDBUF, value);
          } else if (name == StandardSocketOptions.SO_RCVBUF) {
              setOption(SocketOptions.SO_RCVBUF, value);
          } else if (name == StandardSocketOptions.SO_REUSEADDR) {
              setOption(SocketOptions.SO_REUSEADDR, value);
          } else if (name == StandardSocketOptions.IP_TOS) {
              setOption(SocketOptions.IP_TOS, value);
          } else if (name == StandardSocketOptions.IP_MULTICAST_IF &&
              (getDatagramSocket() instanceof MulticastSocket)) {
              setOption(SocketOptions.IP_MULTICAST_IF2, value);
          } else if (name == StandardSocketOptions.IP_MULTICAST_TTL &&
              (getDatagramSocket() instanceof MulticastSocket)) {
              if (! (value instanceof Integer)) {
                  throw new IllegalArgumentException("not an integer");
              }
              setTimeToLive((Integer)value);
          } else if (name == StandardSocketOptions.IP_MULTICAST_LOOP &&
              (getDatagramSocket() instanceof MulticastSocket)) {
              setOption(SocketOptions.IP_MULTICAST_LOOP, value);
          } else {
              throw new UnsupportedOperationException("unsupported option");
          }
      }
  
      <T> T getOption(SocketOption<T> name) throws IOException {
          if (name == StandardSocketOptions.SO_SNDBUF) {
              return (T) getOption(SocketOptions.SO_SNDBUF);
          } else if (name == StandardSocketOptions.SO_RCVBUF) {
              return (T) getOption(SocketOptions.SO_RCVBUF);
          } else if (name == StandardSocketOptions.SO_REUSEADDR) {
              return (T) getOption(SocketOptions.SO_REUSEADDR);
          } else if (name == StandardSocketOptions.IP_TOS) {
              return (T) getOption(SocketOptions.IP_TOS);
          } else if (name == StandardSocketOptions.IP_MULTICAST_IF &&
              (getDatagramSocket() instanceof MulticastSocket)) {
              return (T) getOption(SocketOptions.IP_MULTICAST_IF2);
          } else if (name == StandardSocketOptions.IP_MULTICAST_TTL &&
              (getDatagramSocket() instanceof MulticastSocket)) {
              Integer ttl = getTimeToLive();
              return (T)ttl;
          } else if (name == StandardSocketOptions.IP_MULTICAST_LOOP &&
              (getDatagramSocket() instanceof MulticastSocket)) {
              return (T) getOption(SocketOptions.IP_MULTICAST_LOOP);
          } else {
              throw new UnsupportedOperationException("unsupported option");
          }
      }
  
      /**
       * Gets the datagram socket file descriptor.
       * @return a {@code FileDescriptor} object representing the datagram socket
       * file descriptor
       */
      protected FileDescriptor getFileDescriptor() {
          return fd;
      }
  }
  