Class AFUNIXSocket

java.lang.Object

java.net.Socket

org.newsclub.net.unix.AFSocket<AFUNIXSocketAddress>

org.newsclub.net.unix.AFUNIXSocket

All Implemented Interfaces:

Closeable, AutoCloseable, AFSocketExtensions, AFSomeSocket, AFSomeSocketThing, AFUNIXSocketExtensions, FileDescriptorAccess

public final class AFUNIXSocket
extends AFSocket<AFUNIXSocketAddress>
implements AFUNIXSocketExtensions

Implementation of an AF_UNIX domain socket.

Author:

Christian Kohlschütter

Nested Class Summary

Nested classes/interfaces inherited from class AFSocket

AFSocket.Constructor<A>

Modifier and Type	Class	Description
static interface	AFSocket.Constructor<A extends AFSocketAddress>	The reference to the constructor of an AFSocket subclass.

Method Summary

Modifier and Type	Method	Description
void	clearReceivedFileDescriptors()	Clears the queue of incoming FileDescriptors that were sent as ancillary messages.
static AFUNIXSocket	connectTo(AFUNIXSocketAddress addr)	Creates a new AFSocket and connects it to the given AFUNIXSocketAddress.
AFUNIXSocketChannel	getChannel()
AFUNIXSocketCredentials	getPeerCredentials()	Retrieves the "peer credentials" for this connection.
FileDescriptor[]	getReceivedFileDescriptors()	Retrieves an array of incoming FileDescriptors that were sent as ancillary messages, along with a call to InputStream.read(), etc.
boolean	hasOutboundFileDescriptors()	Returns true if there are pending file descriptors to be sent as part of an ancillary message.
static boolean	isSupported()	Returns true iff AFUNIXSockets are supported by the current Java VM.
static void	main(String[] args)	Very basic self-test function.
protected AFUNIXSocketChannel	newChannel()	Creates a new AFSocketChannel for this socket.
static AFUNIXSocket	newInstance()	Creates a new, unbound AFSocket.
static AFUNIXSocket	newStrictInstance()	Creates a new, unbound, "strict" AFSocket.
void	setOutboundFileDescriptors(FileDescriptor... fdescs)	Sets a list of FileDescriptors that should be sent as an ancillary message along with the next write.

Methods inherited from class AFSocket

addCloseable, bind, checkConnectionClosed, close, connect, connect, connectHook, connectTo, connectTo, ensureAncillaryReceiveBufferSize, ensureSupported, ensureUnsafeSupported, forceConnectAddress, getAncillaryReceiveBufferSize, getFileDescriptor, getImplExtensions, getInputStream, getLoadedLibrary, getLocalSocketAddress, getOutputStream, getRemoteSocketAddress, getVersion, isBound, isClosed, isConnected, isRunningOnAndroid, newInstance, removeCloseable, setAncillaryReceiveBufferSize, setShutdownOnClose, socketAddressClass, supports, supports, toString

Modifier and Type	Method	Description
final void	addCloseable(Closeable closeable)	Registers a Closeable that should be closed when this socket is closed.
final void	bind(SocketAddress bindpoint)	Not fully supported, since it's not necessary for client sockets.
boolean	checkConnectionClosed()	Probes the status of the socket connection.
final void	close()
final void	connect(SocketAddress endpoint)
final void	connect(SocketAddress endpoint, int timeout)
final AFSocket<AFUNIXSocketAddress>	connectHook(SocketAddressFilter hook)	Sets the hook for any subsequent call to AFSocket.connect(SocketAddress) or AFSocket.connect(SocketAddress, int) to be the given function.
static final <A extends AFSocketAddress> AFSocket<?>	connectTo(@NonNull A addr)	Creates a new AFSocket and connects it to the given AFSocketAddress using the default implementation suited for that address type.
protected static final <A extends AFSocketAddress> @NonNull AFSocket<A>	connectTo(AFSocket.Constructor<A> constr, A addr)	Creates a new AFSocket and connects it to the given AFSocketAddress.
final void	ensureAncillaryReceiveBufferSize(int minSize)	Ensures a minimum ancillary receive buffer size.
static void	ensureSupported()	Checks if AFSockets are supported by the current Java VM.
static final void	ensureUnsafeSupported()	Checks if the current environment (system platform, native library, etc.) supports "unsafe" operations (as controlled via the AFSocketCapability.CAPABILITY_UNSAFE capability).
final AFSocket<AFUNIXSocketAddress>	forceConnectAddress(SocketAddress endpoint)	Forces the address to be used for any subsequent call to AFSocket.connect(SocketAddress) to be the given one, regardless of what'll be passed there.
final int	getAncillaryReceiveBufferSize()	Returns the size of the receive buffer for ancillary messages (in bytes).
final FileDescriptor	getFileDescriptor()	Returns the corresponding FileDescriptor.
protected final AFSocketImplExtensions<AFUNIXSocketAddress>	getImplExtensions()	Returns the internal helper instance for address-specific extensions.
final AFInputStream	getInputStream()
static final String	getLoadedLibrary()	Returns an identifier of the loaded native library, or null if the library hasn't been loaded yet.
final AFUNIXSocketAddress	getLocalSocketAddress()	Returns the socket's local socket address, or null if unavailable or if there was a problem retrieving it.
final AFOutputStream	getOutputStream()
final AFUNIXSocketAddress	getRemoteSocketAddress()	Returns the socket's remote socket address, or null if unavailable/not connected, or if there was a problem retrieving it.
static final String	getVersion()	Returns the version of the junixsocket library, as a string, for debugging purposes.
final boolean	isBound()
final boolean	isClosed()
final boolean	isConnected()
static boolean	isRunningOnAndroid()	Checks if we're running on Android (as far as junixsocket is concerned).
protected static final <A extends AFSocketAddress> AFSocket<A>	newInstance(AFSocket.Constructor<A> constr, AFSocketFactory<A> factory)	Creates a new, unbound AFSocket.
final void	removeCloseable(Closeable closeable)	Unregisters a previously registered Closeable.
final void	setAncillaryReceiveBufferSize(int size)	Sets the size of the receive buffer for ancillary messages (in bytes).
void	setShutdownOnClose(boolean enabled)	Configures whether the socket should be shutdown upon Closeable.close(), which is the default.
protected final Class<? extends AFSocketAddress>	socketAddressClass()	Returns the AFSocketAddress type supported by this socket.
static final boolean	supports(AFSocketCapability capability)	Checks if the current environment (system platform, native library, etc.) supports a given junixsocket capability.
static final boolean	supports(AFUNIXSocketCapability capability)	Deprecated.
final String	toString()

Methods inherited from class Socket

getInetAddress, getKeepAlive, getLocalAddress, getLocalPort, getOOBInline, getOption, getPort, getReceiveBufferSize, getReuseAddress, getSendBufferSize, getSoLinger, getSoTimeout, getTcpNoDelay, getTrafficClass, isInputShutdown, isOutputShutdown, sendUrgentData, setKeepAlive, setOOBInline, setOption, setPerformancePreferences, setReceiveBufferSize, setReuseAddress, setSendBufferSize, setSocketImplFactory, setSoLinger, setSoTimeout, setTcpNoDelay, setTrafficClass, shutdownInput, shutdownOutput, supportedOptions

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Details

newChannel

protected AFUNIXSocketChannel newChannel()

Description copied from class: AFSocket

Creates a new AFSocketChannel for this socket.

Specified by:

newChannel in class AFSocket<AFUNIXSocketAddress>

Returns:

The new instance.

newInstance

public static AFUNIXSocket newInstance()
                                throws IOException

Creates a new, unbound AFSocket. This "default" implementation is a bit "lenient" with respect to the specification. In particular, we ignore calls to Socket.getTcpNoDelay() and Socket.setTcpNoDelay(boolean).

Returns:

A new, unbound socket.

Throws:

IOException - if the operation fails.

newStrictInstance

public static AFUNIXSocket newStrictInstance()
                                      throws IOException

Creates a new, unbound, "strict" AFSocket. This call uses an implementation that tries to be closer to the specification than newInstance(), at least for some cases.

Returns:

A new, unbound socket.

Throws:

IOException - if the operation fails.

connectTo

public static AFUNIXSocket connectTo(AFUNIXSocketAddress addr)
                              throws IOException

Creates a new AFSocket and connects it to the given AFUNIXSocketAddress.

Parameters:

addr - The address to connect to.

Returns:

A new, connected socket.

Throws:

IOException - if the operation fails.

getChannel

public AFUNIXSocketChannel getChannel()

Overrides:

getChannel in class AFSocket<AFUNIXSocketAddress>

getPeerCredentials

public AFUNIXSocketCredentials getPeerCredentials()
                                           throws IOException

Description copied from interface: AFUNIXSocketExtensions

Retrieves the "peer credentials" for this connection. These credentials may be useful to authenticate the other end of the socket (client or server). Depending on the socket/connection/environment, you may not receive any or all credentials. For example, on Linux, AFUNIXDatagramSocket and AFUNIXDatagramChannel may not be able to retrieve credentials at all.

Specified by:

getPeerCredentials in interface AFUNIXSocketExtensions

Returns:

The peer's credentials, or null if they couldn't be retrieved.

Throws:

IOException - If there was an error returning these credentials.

getReceivedFileDescriptors

public FileDescriptor[] getReceivedFileDescriptors()
                                            throws IOException

Description copied from interface: AFUNIXSocketExtensions

Retrieves an array of incoming FileDescriptors that were sent as ancillary messages, along with a call to InputStream.read(), etc. NOTE: Another call to this method will not return the same file descriptors again (most likely, an empty array will be returned).

Specified by:

getReceivedFileDescriptors in interface AFUNIXSocketExtensions

Returns:

The file descriptors, or an empty array if none were available.

Throws:

IOException - if the operation fails.

clearReceivedFileDescriptors

public void clearReceivedFileDescriptors()

Description copied from interface: AFUNIXSocketExtensions

Clears the queue of incoming FileDescriptors that were sent as ancillary messages.

Specified by:

clearReceivedFileDescriptors in interface AFUNIXSocketExtensions

setOutboundFileDescriptors

public void setOutboundFileDescriptors(FileDescriptor... fdescs)
                                throws IOException

Description copied from interface: AFUNIXSocketExtensions

Sets a list of FileDescriptors that should be sent as an ancillary message along with the next write. Important: There can only be one set of file descriptors active until the write completes. The socket also needs to be connected for this operation to succeed. It is also important to know that there may be an upper limit imposed by the operation system as to how many file descriptors can be sent at once. Linux, for example, may support up to 253. If the number of file descriptors exceeds the limit, an exception may be thrown when sending data along with the ancillary message containing the file descriptors.

Specified by:

setOutboundFileDescriptors in interface AFUNIXSocketExtensions

Parameters:

fdescs - The file descriptors, or null if none.

Throws:

IOException - if the operation fails.

hasOutboundFileDescriptors

public boolean hasOutboundFileDescriptors()

Description copied from interface: AFUNIXSocketExtensions

Returns true if there are pending file descriptors to be sent as part of an ancillary message.

Specified by:

hasOutboundFileDescriptors in interface AFUNIXSocketExtensions

Returns:

true if there are file descriptors pending.

isSupported

public static boolean isSupported()

Returns true iff AFUNIXSockets are supported by the current Java VM. To support AFSockets, a custom JNI library must be loaded that is supplied with junixsocket, and the system must support AF_UNIX sockets. This call is equivalent to checking AFSocket.isSupported() and AFSocket.supports(AFSocketCapability) with AFSocketCapability.CAPABILITY_UNIX_DOMAIN.

Returns:

true iff supported.

main

public static void main(String[] args)

Very basic self-test function. Prints "supported" and "capabilities" status to System.out.

Parameters:

args - ignored.