jdk/src/java.base/share/classes/java/net/SocketOptions.java
changeset 25859 3317bb8137f4
parent 23720 7d5147c21927
child 32649 2ee9017c7597
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/net/SocketOptions.java	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,331 @@
+/*
+ * 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.lang.annotation.Native;
+
+/**
+ * Interface of methods to get/set socket options.  This interface is
+ * implemented by: <B>SocketImpl</B> and  <B>DatagramSocketImpl</B>.
+ * Subclasses of these should override the methods
+ * of this interface in order to support their own options.
+ * <P>
+ * The methods and constants which specify options in this interface are
+ * for implementation only.  If you're not subclassing SocketImpl or
+ * DatagramSocketImpl, <B>you won't use these directly.</B> There are
+ * type-safe methods to get/set each of these options in Socket, ServerSocket,
+ * DatagramSocket and MulticastSocket.
+ *
+ * @author David Brown
+ */
+
+
+public interface SocketOptions {
+
+    /**
+     * Enable/disable the option specified by <I>optID</I>.  If the option
+     * is to be enabled, and it takes an option-specific "value",  this is
+     * passed in <I>value</I>.  The actual type of value is option-specific,
+     * and it is an error to pass something that isn't of the expected type:
+     * <BR><PRE>
+     * SocketImpl s;
+     * ...
+     * s.setOption(SO_LINGER, new Integer(10));
+     *    // OK - set SO_LINGER w/ timeout of 10 sec.
+     * s.setOption(SO_LINGER, new Double(10));
+     *    // ERROR - expects java.lang.Integer
+     *</PRE>
+     * If the requested option is binary, it can be set using this method by
+     * a java.lang.Boolean:
+     * <BR><PRE>
+     * s.setOption(TCP_NODELAY, new Boolean(true));
+     *    // OK - enables TCP_NODELAY, a binary option
+     * </PRE>
+     * <BR>
+     * Any option can be disabled using this method with a Boolean(false):
+     * <BR><PRE>
+     * s.setOption(TCP_NODELAY, new Boolean(false));
+     *    // OK - disables TCP_NODELAY
+     * s.setOption(SO_LINGER, new Boolean(false));
+     *    // OK - disables SO_LINGER
+     * </PRE>
+     * <BR>
+     * For an option that has a notion of on and off, and requires
+     * a non-boolean parameter, setting its value to anything other than
+     * <I>Boolean(false)</I> implicitly enables it.
+     * <BR>
+     * Throws SocketException if the option is unrecognized,
+     * the socket is closed, or some low-level error occurred
+     * <BR>
+     * @param optID identifies the option
+     * @param value the parameter of the socket option
+     * @throws SocketException if the option is unrecognized,
+     * the socket is closed, or some low-level error occurred
+     * @see #getOption(int)
+     */
+    public void
+        setOption(int optID, Object value) throws SocketException;
+
+    /**
+     * Fetch the value of an option.
+     * Binary options will return java.lang.Boolean(true)
+     * if enabled, java.lang.Boolean(false) if disabled, e.g.:
+     * <BR><PRE>
+     * SocketImpl s;
+     * ...
+     * Boolean noDelay = (Boolean)(s.getOption(TCP_NODELAY));
+     * if (noDelay.booleanValue()) {
+     *     // true if TCP_NODELAY is enabled...
+     * ...
+     * }
+     * </PRE>
+     * <P>
+     * For options that take a particular type as a parameter,
+     * getOption(int) will return the parameter's value, else
+     * it will return java.lang.Boolean(false):
+     * <PRE>
+     * Object o = s.getOption(SO_LINGER);
+     * if (o instanceof Integer) {
+     *     System.out.print("Linger time is " + ((Integer)o).intValue());
+     * } else {
+     *   // the true type of o is java.lang.Boolean(false);
+     * }
+     * </PRE>
+     *
+     * @param optID an {@code int} identifying the option to fetch
+     * @return the value of the option
+     * @throws SocketException if the socket is closed
+     * @throws SocketException if <I>optID</I> is unknown along the
+     *         protocol stack (including the SocketImpl)
+     * @see #setOption(int, java.lang.Object)
+     */
+    public Object getOption(int optID) throws SocketException;
+
+    /**
+     * The java-supported BSD-style options.
+     */
+
+    /**
+     * Disable Nagle's algorithm for this connection.  Written data
+     * to the network is not buffered pending acknowledgement of
+     * previously written data.
+     *<P>
+     * Valid for TCP only: SocketImpl.
+     *
+     * @see Socket#setTcpNoDelay
+     * @see Socket#getTcpNoDelay
+     */
+
+    @Native public final static int TCP_NODELAY = 0x0001;
+
+    /**
+     * Fetch the local address binding of a socket (this option cannot
+     * be "set" only "gotten", since sockets are bound at creation time,
+     * and so the locally bound address cannot be changed).  The default local
+     * address of a socket is INADDR_ANY, meaning any local address on a
+     * multi-homed host.  A multi-homed host can use this option to accept
+     * connections to only one of its addresses (in the case of a
+     * ServerSocket or DatagramSocket), or to specify its return address
+     * to the peer (for a Socket or DatagramSocket).  The parameter of
+     * this option is an InetAddress.
+     * <P>
+     * This option <B>must</B> be specified in the constructor.
+     * <P>
+     * Valid for: SocketImpl, DatagramSocketImpl
+     *
+     * @see Socket#getLocalAddress
+     * @see DatagramSocket#getLocalAddress
+     */
+
+    @Native public final static int SO_BINDADDR = 0x000F;
+
+    /** Sets SO_REUSEADDR for a socket.  This is used only for MulticastSockets
+     * in java, and it is set by default for MulticastSockets.
+     * <P>
+     * Valid for: DatagramSocketImpl
+     */
+
+    @Native public final static int SO_REUSEADDR = 0x04;
+
+    /**
+     * Sets SO_BROADCAST for a socket. This option enables and disables
+     * the ability of the process to send broadcast messages. It is supported
+     * for only datagram sockets and only on networks that support
+     * the concept of a broadcast message (e.g. Ethernet, token ring, etc.),
+     * and it is set by default for DatagramSockets.
+     * @since 1.4
+     */
+
+    @Native public final static int SO_BROADCAST = 0x0020;
+
+    /** Set which outgoing interface on which to send multicast packets.
+     * Useful on hosts with multiple network interfaces, where applications
+     * want to use other than the system default.  Takes/returns an InetAddress.
+     * <P>
+     * Valid for Multicast: DatagramSocketImpl
+     *
+     * @see MulticastSocket#setInterface(InetAddress)
+     * @see MulticastSocket#getInterface()
+     */
+
+    @Native public final static int IP_MULTICAST_IF = 0x10;
+
+    /** Same as above. This option is introduced so that the behaviour
+     *  with IP_MULTICAST_IF will be kept the same as before, while
+     *  this new option can support setting outgoing interfaces with either
+     *  IPv4 and IPv6 addresses.
+     *
+     *  NOTE: make sure there is no conflict with this
+     * @see MulticastSocket#setNetworkInterface(NetworkInterface)
+     * @see MulticastSocket#getNetworkInterface()
+     * @since 1.4
+     */
+    @Native public final static int IP_MULTICAST_IF2 = 0x1f;
+
+    /**
+     * This option enables or disables local loopback of multicast datagrams.
+     * This option is enabled by default for Multicast Sockets.
+     * @since 1.4
+     */
+
+    @Native public final static int IP_MULTICAST_LOOP = 0x12;
+
+    /**
+     * This option sets the type-of-service or traffic class field
+     * in the IP header for a TCP or UDP socket.
+     * @since 1.4
+     */
+
+    @Native public final static int IP_TOS = 0x3;
+
+    /**
+     * Specify a linger-on-close timeout.  This option disables/enables
+     * immediate return from a <B>close()</B> of a TCP Socket.  Enabling
+     * this option with a non-zero Integer <I>timeout</I> means that a
+     * <B>close()</B> will block pending the transmission and acknowledgement
+     * of all data written to the peer, at which point the socket is closed
+     * <I>gracefully</I>.  Upon reaching the linger timeout, the socket is
+     * closed <I>forcefully</I>, with a TCP RST. Enabling the option with a
+     * timeout of zero does a forceful close immediately. If the specified
+     * timeout value exceeds 65,535 it will be reduced to 65,535.
+     * <P>
+     * Valid only for TCP: SocketImpl
+     *
+     * @see Socket#setSoLinger
+     * @see Socket#getSoLinger
+     */
+    @Native public final static int SO_LINGER = 0x0080;
+
+    /** Set a timeout on blocking Socket operations:
+     * <PRE>
+     * ServerSocket.accept();
+     * SocketInputStream.read();
+     * DatagramSocket.receive();
+     * </PRE>
+     *
+     * <P> The option must be set prior to entering a blocking
+     * operation to take effect.  If the timeout expires and the
+     * operation would continue to block,
+     * <B>java.io.InterruptedIOException</B> is raised.  The Socket is
+     * not closed in this case.
+     *
+     * <P> Valid for all sockets: SocketImpl, DatagramSocketImpl
+     *
+     * @see Socket#setSoTimeout
+     * @see ServerSocket#setSoTimeout
+     * @see DatagramSocket#setSoTimeout
+     */
+    @Native public final static int SO_TIMEOUT = 0x1006;
+
+    /**
+     * Set a hint the size of the underlying buffers used by the
+     * platform for outgoing network I/O. When used in set, this is a
+     * suggestion to the kernel from the application about the size of
+     * buffers to use for the data to be sent over the socket. When
+     * used in get, this must return the size of the buffer actually
+     * used by the platform when sending out data on this socket.
+     *
+     * Valid for all sockets: SocketImpl, DatagramSocketImpl
+     *
+     * @see Socket#setSendBufferSize
+     * @see Socket#getSendBufferSize
+     * @see DatagramSocket#setSendBufferSize
+     * @see DatagramSocket#getSendBufferSize
+     */
+    @Native public final static int SO_SNDBUF = 0x1001;
+
+    /**
+     * Set a hint the size of the underlying buffers used by the
+     * platform for incoming network I/O. When used in set, this is a
+     * suggestion to the kernel from the application about the size of
+     * buffers to use for the data to be received over the
+     * socket. When used in get, this must return the size of the
+     * buffer actually used by the platform when receiving in data on
+     * this socket.
+     *
+     * Valid for all sockets: SocketImpl, DatagramSocketImpl
+     *
+     * @see Socket#setReceiveBufferSize
+     * @see Socket#getReceiveBufferSize
+     * @see DatagramSocket#setReceiveBufferSize
+     * @see DatagramSocket#getReceiveBufferSize
+     */
+    @Native public final static int SO_RCVBUF = 0x1002;
+
+    /**
+     * When the keepalive option is set for a TCP socket and no data
+     * has been exchanged across the socket in either direction for
+     * 2 hours (NOTE: the actual value is implementation dependent),
+     * TCP automatically sends a keepalive probe to the peer. This probe is a
+     * TCP segment to which the peer must respond.
+     * One of three responses is expected:
+     * 1. The peer responds with the expected ACK. The application is not
+     *    notified (since everything is OK). TCP will send another probe
+     *    following another 2 hours of inactivity.
+     * 2. The peer responds with an RST, which tells the local TCP that
+     *    the peer host has crashed and rebooted. The socket is closed.
+     * 3. There is no response from the peer. The socket is closed.
+     *
+     * The purpose of this option is to detect if the peer host crashes.
+     *
+     * Valid only for TCP socket: SocketImpl
+     *
+     * @see Socket#setKeepAlive
+     * @see Socket#getKeepAlive
+     */
+    @Native public final static int SO_KEEPALIVE = 0x0008;
+
+    /**
+     * When the OOBINLINE option is set, any TCP urgent data received on
+     * the socket will be received through the socket input stream.
+     * When the option is disabled (which is the default) urgent data
+     * is silently discarded.
+     *
+     * @see Socket#setOOBInline
+     * @see Socket#getOOBInline
+     */
+    @Native public final static int SO_OOBINLINE = 0x1003;
+}