/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.net;
/**
* Defines an interface for socket implementations to get and set socket
* options. It is implemented by the classes {@code SocketImpl} and {@code
* DatagramSocketImpl}.
*
* @see SocketImpl
* @see DatagramSocketImpl
*/
public interface SocketOptions {
/**
* Number of seconds to wait when closing a socket if there is still some buffered data to be
* sent.
*
* <p>The option can be set to disabled using {@link #setOption(int, Object)} with a value of
* {@code Boolean.FALSE}.
*
* <p>If this option is set to 0, the TCP socket is closed forcefully and the call to
* {@code close} returns immediately.
*
* If this option is disabled, closing a socket will return immediately and the close will be
* handled in the background.
*
* <p>If this option is set to a value greater than 0, the value is interpreted as the number of
* seconds to wait. If all data could be sent during this time, the socket is closed normally.
* Otherwise the connection will be closed forcefully.
*
* <p>Valid numeric values for this option are in the range 0 to 65535 inclusive. (Larger
* timeouts will be treated as 65535s timeouts; roughly 18 hours.)
*
* <p>This option is intended for use with sockets in blocking mode. The behavior of this option
* for non-blocking sockets is undefined.
*/
public static final int SO_LINGER = 128;
/**
* Integer timeout in milliseconds for blocking accept or read/receive operations (but not
* write/send operations). A timeout of 0 means no timeout. Negative
* timeouts are not allowed.
*
* <p>An {@code InterruptedIOException} is thrown if this timeout expires.
*/
public static final int SO_TIMEOUT = 4102;
/**
* This boolean option specifies whether data is sent immediately on this socket or buffered.
* <p>
* If set to {@code Boolean.TRUE} the Nagle algorithm is disabled and there is no buffering.
* This could lead to low packet efficiency. When set to {@code Boolean.FALSE} the the socket
* implementation uses buffering to try to reach a higher packet efficiency.
*
* <p>See <a href="http://www.ietf.org/rfc/rfc1122.txt">RFC 1122: Requirements for Internet
* Hosts -- Communication Layers</a> for more information about buffering and the Nagle
* algorithm.
*/
public static final int TCP_NODELAY = 1;
/**
* This is an IPv4-only socket option whose functionality is subsumed by
* {@link #IP_MULTICAST_IF2} and not implemented on Android.
*/
public static final int IP_MULTICAST_IF = 16;
/**
* This option does not correspond to any Unix socket option and is not implemented on Android.
*/
public static final int SO_BINDADDR = 15;
/**
* This boolean option specifies whether a reuse of a local address is allowed when another
* socket has not yet been removed by the operating system.
*
* <p>For connection-oriented sockets, if this option is disabled and if there is another socket
* in state TIME_WAIT on a given address then another socket binding to that address would fail.
* Setting this value after a socket is bound has no effect.
*
* <p>For datagram sockets this option determines whether several sockets can listen on the
* same address; when enabled each socket will receive a copy of the datagram.
*
* <p>See <a href="https://www.ietf.org/rfc/rfc793.txt">RFC 793: Transmission Control Protocol
* </a> for more information about socket re-use.
*/
public static final int SO_REUSEADDR = 4;
/**
* The size in bytes of a socket's send buffer. This must be an integer greater than 0.
* This is a hint to the kernel; the kernel may use a larger buffer.
*
* <p>For datagram sockets, it is implementation-defined whether packets larger than
* this size can be sent.
*/
public static final int SO_SNDBUF = 4097;
/**
* The size in bytes of a socket's receive buffer. This must be an integer greater than 0.
* This is a hint to the kernel; the kernel may use a larger buffer.
*
* <p>For datagram sockets, packets larger than this value will be discarded.
*
* <p>See <a href="http://www.ietf.org/rfc/rfc1323.txt">RFC1323: TCP Extensions for High
* Performance</a> for more information about TCP/IP buffering.
*/
public static final int SO_RCVBUF = 4098;
/**
* This boolean option specifies whether the kernel sends keepalive messages on
* connection-oriented sockets.
*
* <p>See <a href="http://www.ietf.org/rfc/rfc1122.txt">RFC 1122: Requirements for Internet
* Hosts -- Communication Layers</a> for more information on keep-alive.
*/
public static final int SO_KEEPALIVE = 8;
/**
* This integer option specifies the value for the type-of-service field of the IPv4 header,
* or the traffic class field of the IPv6 header. These correspond to the IP_TOS and IPV6_TCLASS
* socket options. These may be ignored by the underlying OS. Values must be between 0 and 255
* inclusive.
*
* <p>See <a href="http://www.ietf.org/rfc/rfc1349.txt">RFC 1349</a> for more about IPv4
* and <a href="http://www.ietf.org/rfc/rfc2460.txt">RFC 2460</a> for more about IPv6.
*/
public static final int IP_TOS = 3;
/**
* This boolean option specifies whether the local loopback of multicast packets is
* enabled or disabled. This loopback is enabled by default on multicast sockets.
*
* <p>See <a href="http://tools.ietf.org/rfc/rfc1112.txt">RFC 1112: Host Extensions for IP
* Multicasting</a> for more information about IP multicast.
*
* <p>See {@link MulticastSocket#setLoopbackMode}.
*/
public static final int IP_MULTICAST_LOOP = 18;
/**
* This boolean option can be used to enable or disable broadcasting on datagram sockets. This
* option must be enabled to send broadcast messages. The default value is false.
*/
public static final int SO_BROADCAST = 32;
/**
* This boolean option specifies whether sending TCP urgent data is supported on
* this socket or not.
*/
public static final int SO_OOBINLINE = 4099;
/**
* This integer option sets the outgoing interface for multicast packets
* using an interface index.
*
* <p>See <a href="http://tools.ietf.org/rfc/rfc1112.txt">RFC 1112: Host Extensions for IP
* Multicasting</a> for more information about IP multicast.
*/
public static final int IP_MULTICAST_IF2 = 31;
/**
* Gets the value for the specified socket option.
*
* @return the option value.
* @param optID
* the option identifier.
* @throws SocketException
* if an error occurs reading the option value.
*/
public Object getOption(int optID) throws SocketException;
/**
* Sets the value of the specified socket option.
*
* @param optID
* the option identifier.
* @param val
* the value to be set for the option.
* @throws SocketException
* if an error occurs setting the option value.
*/
public void setOption(int optID, Object val) throws SocketException;
}