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	/*
	* Copyright (c) 1995, 2021, 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.IOException;
	import java.nio.channels.DatagramChannel;
	import java.nio.channels.MulticastChannel;

	/**
	* A {@code MulticastSocket} is a datagram socket that is
	* convenient for sending and receiving IP multicast datagrams.
	* The {@code MulticastSocket} constructors create a socket
	* with appropriate socket options enabled that make
	* it suitable for receiving multicast datagrams.
	* The {@code MulticastSocket} class additionally defines
	* convenient setter and getter methods for socket options
	* that are commonly used by multicasting applications.
	* <P>
	* Joining one or more multicast groups makes it possible to
	* receive multicast datagrams sent to these groups.
	* <P>
	* An IPv4 multicast group is specified by a class D IP address
	* and by a standard UDP port number. Class D IP addresses
	* are in the range {@code 224.0.0.0} to {@code 239.255.255.255},
	* inclusive. The address 224.0.0.0 is reserved and should not be used.
	* <P>
	* One would join a multicast group by first creating a MulticastSocket
	* with the desired port, then invoking the
	* <CODE>joinGroup</CODE> method, specifying the group address and
	* the network interface through which multicast datagrams will be
	* received:
	* <PRE>{@code
	* // join a Multicast group and send the group salutations
	* ...
	* String msg = "Hello";
	* InetAddress mcastaddr = InetAddress.getByName("228.5.6.7");
	* InetSocketAddress group = new InetSocketAddress(mcastaddr, 6789);
	* NetworkInterface netIf = NetworkInterface.getByName("bge0");
	* MulticastSocket s = new MulticastSocket(6789);
	*
	* s.joinGroup(new InetSocketAddress(mcastaddr, 0), netIf);
	* byte[] msgBytes = msg.getBytes(StandardCharsets.UTF_8);
	* DatagramPacket hi = new DatagramPacket(msgBytes, msgBytes.length, group);
	* s.send(hi);
	* // get their responses!
	* byte[] buf = new byte[1000];
	* DatagramPacket recv = new DatagramPacket(buf, buf.length);
	* s.receive(recv);
	* ...
	* // OK, I'm done talking - leave the group...
	* s.leaveGroup(group, netIf);
	* }</PRE>
	*
	* When one sends a message to a multicast group, <B>all</B> subscribing
	* recipients to that host and port receive the message (within the
	* time-to-live range of the packet, see below). The socket needn't
	* be a member of the multicast group to send messages to it.
	* <P>
	* When a socket subscribes to a multicast group/port, it receives
	* datagrams sent by other hosts to the group/port, as do all other
	* members of the group and port. A socket relinquishes membership
	* in a group by the leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
	* method.
	* <B>Multiple MulticastSockets</B> may subscribe to a multicast group
	* and port concurrently, and they will all receive group datagrams.
	*
	* <p> The {@code DatagramSocket} and {@code MulticastSocket}
	* classes define convenience methods to set and get several
	* socket options. Like {@code DatagramSocket} this class also
	* supports the {@link #setOption(SocketOption, Object) setOption}
	* and {@link #getOption(SocketOption) getOption} methods to set
	* and query socket options.
	* <a id="MulticastOptions"></a>The set of supported socket options
	* is defined in <a href="DatagramSocket.html#SocketOptions">{@code DatagramSocket}</a>.
	* Additional (implementation specific) options may also be supported.
	*
	* @apiNote {@link DatagramSocket} may be used directly for
	* sending and receiving multicast datagrams.
	* {@link DatagramChannel} implements the {@link MulticastChannel} interface
	* and provides an alternative API for sending and receiving multicast datagrams.
	* The {@link MulticastChannel} API supports both {@linkplain
	* MulticastChannel#join(InetAddress, NetworkInterface) any-source} and
	* {@linkplain MulticastChannel#join(InetAddress, NetworkInterface, InetAddress)
	* source-specific} multicast. Consider using {@link DatagramChannel} for
	* multicasting.
	*
	* @author Pavani Diwanji
	* @since 1.1
	*/
	public class MulticastSocket extends DatagramSocket {

	@Override
	final MulticastSocket delegate() {
	return (MulticastSocket) super.delegate();
	}

	/**
	* Create a MulticastSocket that delegates to the given delegate if not null.
	* @param delegate the delegate, can be null.
	*/
	MulticastSocket(MulticastSocket delegate) {
	super(delegate);
	}


	/**
	* Constructs a multicast socket and binds it to any available port
	* on the local host machine. The socket will be bound to the
	* {@link InetAddress#isAnyLocalAddress wildcard} address.
	*
	* <p>
	* If there is a security manager, its {@code checkListen} method is first
	* called with 0 as its argument to ensure the operation is allowed. This
	* could result in a SecurityException.
	* <p>
	* When the socket is created the
	* {@link DatagramSocket#setReuseAddress(boolean)} method is called to
	* enable the SO_REUSEADDR socket option.
	*
	* @throws IOException if an I/O exception occurs while creating the
	* MulticastSocket
	* @throws SecurityException if a security manager exists and its
	* {@code checkListen} method doesn't allow the operation.
	* @see SecurityManager#checkListen
	* @see java.net.DatagramSocket#setReuseAddress(boolean)
	* @see java.net.DatagramSocketImpl#setOption(SocketOption, Object)
	*/
	public MulticastSocket() throws IOException {
	this(new InetSocketAddress(0));
	}

	/**
	* Constructs a multicast socket and binds it to the specified port
	* on the local host machine. The socket will be bound to the
	* {@link InetAddress#isAnyLocalAddress wildcard} address.
	*
	* <p>If there is a security manager,
	* its {@code checkListen} method is first called
	* with the {@code port} argument
	* as its argument to ensure the operation is allowed.
	* This could result in a SecurityException.
	* <p>
	* When the socket is created the
	* {@link DatagramSocket#setReuseAddress(boolean)} method is
	* called to enable the SO_REUSEADDR socket option.
	*
	* @param port port to use
	* @throws IOException if an I/O exception occurs
	* while creating the MulticastSocket
	* @throws SecurityException if a security manager exists and its
	* {@code checkListen} method doesn't allow the operation.
	* @throws IllegalArgumentException if port is <a href="DatagramSocket.html#PortRange">
	* out of range.</a>
	*
	* @see SecurityManager#checkListen
	* @see java.net.DatagramSocket#setReuseAddress(boolean)
	*/
	public MulticastSocket(int port) throws IOException {
	this(new InetSocketAddress(port));
	}

	/**
	* Creates a multicast socket, bound to the specified local
	* socket address.
	* <p>
	* If the address is {@code null} an unbound socket will be created.
	*
	* <p>If there is a security manager,
	* its {@code checkListen} method is first called
	* with the SocketAddress port as its argument to ensure the operation is allowed.
	* This could result in a SecurityException.
	* <p>
	* When the socket is created the
	* {@link DatagramSocket#setReuseAddress(boolean)} method is
	* called to enable the SO_REUSEADDR socket option.
	*
	* @param bindaddr Socket address to bind to, or {@code null} for
	* an unbound socket.
	* @throws IOException if an I/O exception occurs
	* while creating the MulticastSocket
	* @throws SecurityException if a security manager exists and its
	* {@code checkListen} method doesn't allow the operation.
	* @see SecurityManager#checkListen
	* @see java.net.DatagramSocket#setReuseAddress(boolean)
	*
	* @since 1.4
	*/
	public MulticastSocket(SocketAddress bindaddr) throws IOException {
	this(createDelegate(bindaddr, MulticastSocket.class));
	}

	/**
	* Set the default time-to-live for multicast packets sent out
	* on this {@code MulticastSocket} in order to control the
	* scope of the multicasts.
	*
	* <p>The ttl is an <b>unsigned</b> 8-bit quantity, and so <B>must</B> be
	* in the range {@code 0 <= ttl <= 0xFF }.
	*
	* @param ttl the time-to-live
	* @throws IOException if an I/O exception occurs
	* while setting the default time-to-live value
	* @deprecated use the {@link #setTimeToLive(int)} method instead, which uses
	* <b>int</b> instead of <b>byte</b> as the type for ttl.
	* @see #getTTL()
	*/
	@Deprecated
	public void setTTL(byte ttl) throws IOException {
	delegate().setTTL(ttl);
	}

	/**
	* Set the default time-to-live for multicast packets sent out
	* on this {@code MulticastSocket} in order to control the
	* scope of the multicasts.
	*
	* <P> The ttl <B>must</B> be in the range {@code 0 <= ttl <=
	* 255} or an {@code IllegalArgumentException} will be thrown.
	* Multicast packets sent with a TTL of {@code 0} are not transmitted
	* on the network but may be delivered locally.
	*
	* @apiNote
	* This method is equivalent to calling {@link #setOption(SocketOption, Object)
	* setOption(StandardSocketOptions.IP_MULTICAST_TTL, ttl)}.
	*
	* @param ttl
	* the time-to-live
	*
	* @throws IOException
	* if an I/O exception occurs while setting the
	* default time-to-live value
	*
	* @see #getTimeToLive()
	* @see StandardSocketOptions#IP_MULTICAST_TTL
	* @since 1.2
	*/
	public void setTimeToLive(int ttl) throws IOException {
	delegate().setTimeToLive(ttl);
	}

	/**
	* Get the default time-to-live for multicast packets sent out on
	* the socket.
	*
	* @throws IOException if an I/O exception occurs
	* while getting the default time-to-live value
	* @return the default time-to-live value
	* @deprecated use the {@link #getTimeToLive()} method instead,
	* which returns an <b>int</b> instead of a <b>byte</b>.
	* @see #setTTL(byte)
	*/
	@Deprecated
	public byte getTTL() throws IOException {
	return delegate().getTTL();
	}

	/**
	* Get the default time-to-live for multicast packets sent out on
	* the socket.
	*
	* @apiNote
	* This method is equivalent to calling {@link #getOption(SocketOption)
	* getOption(StandardSocketOptions.IP_MULTICAST_TTL)}.
	*
	* @throws IOException if an I/O exception occurs while
	* getting the default time-to-live value
	* @return the default time-to-live value
	* @see #setTimeToLive(int)
	* @see StandardSocketOptions#IP_MULTICAST_TTL
	* @since 1.2
	*/
	public int getTimeToLive() throws IOException {
	return delegate().getTimeToLive();
	}

	/**
	* Joins a multicast group. Its behavior may be affected by
	* {@code setInterface} or {@code setNetworkInterface}.
	*
	* <p>If there is a security manager, this method first
	* calls its {@code checkMulticast} method with the
	* {@code mcastaddr} argument as its argument.
	*
	* @apiNote
	* Calling this method is equivalent to calling
	* {@link #joinGroup(SocketAddress, NetworkInterface)
	* joinGroup(new InetSocketAddress(mcastaddr, 0), null)}.
	*
	* @param mcastaddr is the multicast address to join
	* @throws IOException if there is an error joining,
	* or when the address is not a multicast address,
	* or the platform does not support multicasting
	* @throws SecurityException if a security manager exists and its
	* {@code checkMulticast} method doesn't allow the join.
	* @deprecated This method does not accept the network interface on
	* which to join the multicast group. Use
	* {@link #joinGroup(SocketAddress, NetworkInterface)} instead.
	* @see SecurityManager#checkMulticast(InetAddress)
	*/
	@Deprecated(since="14")
	public void joinGroup(InetAddress mcastaddr) throws IOException {
	delegate().joinGroup(mcastaddr);
	}

	/**
	* Leave a multicast group. Its behavior may be affected by
	* {@code setInterface} or {@code setNetworkInterface}.
	*
	* <p>If there is a security manager, this method first
	* calls its {@code checkMulticast} method with the
	* {@code mcastaddr} argument as its argument.
	*
	* @apiNote
	* Calling this method is equivalent to calling
	* {@link #leaveGroup(SocketAddress, NetworkInterface)
	* leaveGroup(new InetSocketAddress(mcastaddr, 0), null)}.
	*
	* @param mcastaddr is the multicast address to leave
	* @throws IOException if there is an error leaving
	* or when the address is not a multicast address.
	* @throws SecurityException if a security manager exists and its
	* {@code checkMulticast} method doesn't allow the operation.
	* @deprecated This method does not accept the network interface on which
	* to leave the multicast group. Use
	* {@link #leaveGroup(SocketAddress, NetworkInterface)} instead.
	* @see SecurityManager#checkMulticast(InetAddress)
	*/
	@Deprecated(since="14")
	public void leaveGroup(InetAddress mcastaddr) throws IOException {
	delegate().leaveGroup(mcastaddr);
	}

	/**
	* {@inheritDoc}
	* @throws IOException {@inheritDoc}
	* @throws SecurityException {@inheritDoc}
	* @throws IllegalArgumentException {@inheritDoc}
	* @see SecurityManager#checkMulticast(InetAddress)
	* @see DatagramChannel#join(InetAddress, NetworkInterface)
	* @see StandardSocketOptions#IP_MULTICAST_IF
	* @see #setNetworkInterface(NetworkInterface)
	* @see #setInterface(InetAddress)
	* @since 1.4
	*/
	@Override
	public void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf)
	throws IOException {
	super.joinGroup(mcastaddr, netIf);
	}

	/**
	* {@inheritDoc}
	* @apiNote {@inheritDoc}
	* @throws IOException {@inheritDoc}
	* @throws SecurityException {@inheritDoc}
	* @throws IllegalArgumentException {@inheritDoc}
	* @see SecurityManager#checkMulticast(InetAddress)
	* @see #joinGroup(SocketAddress, NetworkInterface)
	* @since 1.4
	*/
	@Override
	public void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
	throws IOException {
	super.leaveGroup(mcastaddr, netIf);
	}

	/**
	* Set the multicast network interface used by methods
	* whose behavior would be affected by the value of the
	* network interface. Useful for multihomed hosts.
	*
	* @param inf the InetAddress
	* @throws SocketException if there is an error in
	* the underlying protocol, such as a TCP error.
	* @deprecated The InetAddress may not uniquely identify
	* the network interface. Use
	* {@link #setNetworkInterface(NetworkInterface)} instead.
	* @see #getInterface()
	*/
	@Deprecated(since="14")
	public void setInterface(InetAddress inf) throws SocketException {
	delegate().setInterface(inf);
	}

	/**
	* Retrieve the address of the network interface used for
	* multicast packets.
	*
	* @return An {@code InetAddress} representing the address
	* of the network interface used for multicast packets,
	* or if no interface has been set, an {@code InetAddress}
	* representing any local address.
	* @throws SocketException if there is an error in the
	* underlying protocol, such as a TCP error.
	* @deprecated The network interface may not be uniquely identified by
	* the InetAddress returned.
	* Use {@link #getNetworkInterface()} instead.
	* @see #setInterface(java.net.InetAddress)
	*/
	@Deprecated(since="14")
	public InetAddress getInterface() throws SocketException {
	return delegate().getInterface();
	}

	/**
	* Specify the network interface for outgoing multicast datagrams
	* sent on this socket.
	*
	* @apiNote
	* This method is equivalent to calling {@link #setOption(SocketOption, Object)
	* setOption(StandardSocketOptions.IP_MULTICAST_IF, netIf)}.
	*
	* @param netIf the interface
	* @throws SocketException if there is an error in
	* the underlying protocol, such as a TCP error.
	* @see #getNetworkInterface()
	* @see StandardSocketOptions#IP_MULTICAST_IF
	* @since 1.4
	*/
	public void setNetworkInterface(NetworkInterface netIf)
	throws SocketException {
	delegate().setNetworkInterface(netIf);
	}

	/**
	* Get the multicast network interface set for outgoing multicast
	* datagrams sent from this socket.
	*
	* @apiNote
	* When an interface is set, this method is equivalent
	* to calling {@link #getOption(SocketOption)
	* getOption(StandardSocketOptions.IP_MULTICAST_IF)}.
	*
	* @throws SocketException if there is an error in
	* the underlying protocol, such as a TCP error.
	* @return The multicast {@code NetworkInterface} currently set. A placeholder
	* NetworkInterface is returned when there is no interface set; it has
	* a single InetAddress to represent any local address.
	* @see #setNetworkInterface(NetworkInterface)
	* @see StandardSocketOptions#IP_MULTICAST_IF
	* @since 1.4
	*/
	public NetworkInterface getNetworkInterface() throws SocketException {
	return delegate().getNetworkInterface();
	}

	/**
	* Disable/Enable local loopback of multicast datagrams.
	* The option is used by the platform's networking code as a hint
	* for setting whether multicast data will be looped back to
	* the local socket.
	*
	* <p>Because this option is a hint, applications that want to
	* verify what loopback mode is set to should call
	* {@link #getLoopbackMode()}
	* @param disable {@code true} to disable the LoopbackMode
	* @throws SocketException if an error occurs while setting the value
	* @since 1.4
	* @deprecated Use {@link #setOption(SocketOption, Object)} with
	* {@link java.net.StandardSocketOptions#IP_MULTICAST_LOOP}
	* instead. The loopback mode is enabled by default,
	* {@code MulticastSocket.setOption(StandardSocketOptions.IP_MULTICAST_LOOP, false)}
	* disables it.
	* @see #getLoopbackMode
	*/
	@Deprecated(since="14")
	public void setLoopbackMode(boolean disable) throws SocketException {
	delegate().setLoopbackMode(disable);
	}

	/**
	* Get the setting for local loopback of multicast datagrams.
	*
	* @throws SocketException if an error occurs while getting the value
	* @return true if the LoopbackMode has been disabled
	* @since 1.4
	* @deprecated Use {@link #getOption(SocketOption)} with
	* {@link java.net.StandardSocketOptions#IP_MULTICAST_LOOP}
	* instead.
	* @see #setLoopbackMode
	*/
	@Deprecated(since="14")
	public boolean getLoopbackMode() throws SocketException {
	return delegate().getLoopbackMode();
	}

	/**
	* Sends a datagram packet to the destination, with a TTL (time-to-live)
	* other than the default for the socket. This method
	* need only be used in instances where a particular TTL is desired;
	* otherwise it is preferable to set a TTL once on the socket, and
	* use that default TTL for all packets. This method does <B>not
	* </B> alter the default TTL for the socket. Its behavior may be
	* affected by {@code setInterface}.
	*
	* <p>If there is a security manager, this method first performs some
	* security checks. First, if {@code p.getAddress().isMulticastAddress()}
	* is true, this method calls the
	* security manager's {@code checkMulticast} method
	* with {@code p.getAddress()} and {@code ttl} as its arguments.
	* If the evaluation of that expression is false,
	* this method instead calls the security manager's
	* {@code checkConnect} method with arguments
	* {@code p.getAddress().getHostAddress()} and
	* {@code p.getPort()}. Each call to a security manager method
	* could result in a SecurityException if the operation is not allowed.
	*
	* @param p is the packet to be sent. The packet should contain
	* the destination multicast ip address and the data to be sent.
	* One does not need to be the member of the group to send
	* packets to a destination multicast address.
	* @param ttl optional time to live for multicast packet.
	* default ttl is 1.
	*
	* @throws IOException is raised if an error occurs i.e
	* error while setting ttl.
	* @throws SecurityException if a security manager exists and its
	* {@code checkMulticast} or {@code checkConnect}
	* method doesn't allow the send.
	* @throws 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.
	* @throws IllegalArgumentException if the socket is connected,
	* and connected address and packet address differ, or
	* if the socket is not connected and the packet address
	* is not set or if its port is out of range.
	*
	*
	* @deprecated Use the following code or its equivalent instead:
	* <pre>{@code ......
	* int ttl = mcastSocket.getOption(StandardSocketOptions.IP_MULTICAST_TTL);
	* mcastSocket.setOption(StandardSocketOptions.IP_MULTICAST_TTL, newttl);
	* mcastSocket.send(p);
	* mcastSocket.setOption(StandardSocketOptions.IP_MULTICAST_TTL, ttl);
	* ......}</pre>
	*
	* @see DatagramSocket#send
	* @see DatagramSocket#receive
	* @see SecurityManager#checkMulticast(java.net.InetAddress, byte)
	* @see SecurityManager#checkConnect
	*/
	@Deprecated
	public void send(DatagramPacket p, byte ttl)
	throws IOException {
	delegate().send(p, ttl);
	}
	}

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