Module org.newsclub.net.unix

Package org.newsclub.net.unix

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 org.newsclub.net.unix.AFSocket

AFSocket.Constructor<A extends AFSocketAddress>

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 org.newsclub.net.unix.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

Methods inherited from class java.net.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 java.lang.Object

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

Methods inherited from interface org.newsclub.net.unix.AFSocketExtensions

ensureAncillaryReceiveBufferSize, getAncillaryReceiveBufferSize, setAncillaryReceiveBufferSize

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.