Module org.newsclub.net.unix

Package org.newsclub.net.unix

Enum Class AFSocketCapability

java.lang.Object

java.lang.Enum<AFSocketCapability>

org.newsclub.net.unix.AFSocketCapability

All Implemented Interfaces:

Serializable, Comparable<AFSocketCapability>, Constable

public enum AFSocketCapability
extends Enum<AFSocketCapability>

Describes junixsocket capabilities the current environment (system platform, native library, etc.) may or may not support. You can check whether your environment supports a given capability by calling AFSocket.supports(AFSocketCapability). You can also manually disable a given capability by specifying a System property of the form org.newsclub.net.unix.library.disable.CAPABILITY_SOMETHING_SOMETHING=true when invoking the JVM (make sure this property is set before junixsocket is accessed). A simple way to check which capabilities are supported in an environment is to run the `junixsocket-selftest` jar.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
CAPABILITY_ABSTRACT_NAMESPACE	Socket addressing supports the abstract namespace (Linux).
CAPABILITY_ANCILLARY_MESSAGES	Socket supports sending and receiving ancillary messages.
CAPABILITY_DARWIN	Support for certain Darwin (macOS Kernel)-specific features, such as the AF_SYSTEM domain.
CAPABILITY_FD_AS_REDIRECT	A file descriptor can be converted to ProcessBuilder.Redirect.
CAPABILITY_FILE_DESCRIPTORS	Socket supports passing file descriptors via ancillary messages.
CAPABILITY_LARGE_PORTS	Support for port numbers larger than 65535 (0xffff).
CAPABILITY_NATIVE_SOCKETPAIR	A pair of interconnected sockets can be created natively as AF_UNIX sockets.
CAPABILITY_PEER_CREDENTIALS	Socket supports retrieving peer credentials.
CAPABILITY_TIPC	Support for AF_TIPC.
CAPABILITY_UNIX_DATAGRAMS	Support for AF_UNIX datagrams.
CAPABILITY_UNIX_DOMAIN	Support for AF_UNIX.
CAPABILITY_UNSAFE	Support for "unsafe" operations.
CAPABILITY_VSOCK	Support for AF_VSOCK.
CAPABILITY_VSOCK_DGRAM	Support for AF_VSOCK datagrams (not all platforms/kernel versions or configurations support this).
CAPABILITY_ZERO_LENGTH_SEND	Support for zero-length send(2).

Method Summary

Modifier and Type	Method	Description
static AFSocketCapability	valueOf(String name)	Returns the enum constant of this class with the specified name.
static AFSocketCapability[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

CAPABILITY_PEER_CREDENTIALS

public static final AFSocketCapability CAPABILITY_PEER_CREDENTIALS

Socket supports retrieving peer credentials.

CAPABILITY_ANCILLARY_MESSAGES

public static final AFSocketCapability CAPABILITY_ANCILLARY_MESSAGES

Socket supports sending and receiving ancillary messages.

CAPABILITY_FILE_DESCRIPTORS

public static final AFSocketCapability CAPABILITY_FILE_DESCRIPTORS

Socket supports passing file descriptors via ancillary messages.

CAPABILITY_ABSTRACT_NAMESPACE

public static final AFSocketCapability CAPABILITY_ABSTRACT_NAMESPACE

Socket addressing supports the abstract namespace (Linux).

CAPABILITY_UNIX_DATAGRAMS

public static final AFSocketCapability CAPABILITY_UNIX_DATAGRAMS

Support for AF_UNIX datagrams.

CAPABILITY_NATIVE_SOCKETPAIR

public static final AFSocketCapability CAPABILITY_NATIVE_SOCKETPAIR

A pair of interconnected sockets can be created natively as AF_UNIX sockets. This currently not possible on Windows, but instead emulated via anonymous AF_INET ports when you use AFSocketPair. Other systems may provide partial implementations of pipe-based (i.e., non-socket) pairs. This capability is specific to AF_UNIX sockets. Other sockets, such as AF_VSOCK, may not implement socketpair natively even if this capability is set, but would work-around that limitation in a similar fashion but maybe without resorting to AF_INET.

CAPABILITY_FD_AS_REDIRECT

public static final AFSocketCapability CAPABILITY_FD_AS_REDIRECT

A file descriptor can be converted to ProcessBuilder.Redirect. This feature currently uses Java SDK internals that may change/disappear.

CAPABILITY_TIPC

public static final AFSocketCapability CAPABILITY_TIPC

Support for AF_TIPC. Availability of this feature is checked upon launch and therefore loading the "tipc" kernel module at a later point may not be properly reflected.

CAPABILITY_UNIX_DOMAIN

public static final AFSocketCapability CAPABILITY_UNIX_DOMAIN

Support for AF_UNIX. Availability of this feature is checked upon launch and therefore, on systems adding support at a later point, may not be properly reflected when checking at a later point. NOTE: While this capability is typically supported on most systems that can actually load a junixsocket JNI library, it is unavailable for older Windows versions (such as 8.1, 10 before AFUNIX.SYS was included, etc.) and on systems where support for UNIX domain sockets is actively disabled. Therefore, it is still recommended to check for this capability.

CAPABILITY_VSOCK

public static final AFSocketCapability CAPABILITY_VSOCK

Support for AF_VSOCK. Availability of this feature is checked upon launch and therefore enabling vsock at a later point may not be properly reflected.

See Also:

• CAPABILITY_VSOCK_DGRAM

CAPABILITY_VSOCK_DGRAM

public static final AFSocketCapability CAPABILITY_VSOCK_DGRAM

Support for AF_VSOCK datagrams (not all platforms/kernel versions or configurations support this). Availability of this feature is checked upon launch and therefore enabling vsock at a later point may not be properly reflected.

CAPABILITY_ZERO_LENGTH_SEND

public static final AFSocketCapability CAPABILITY_ZERO_LENGTH_SEND

Support for zero-length send(2). This can be used to perform a connection check, but not all operating systems support this or behave correctly (particularly, IBM AIX, IBM i, and IBM z/OS) at the moment. If not supported, junixsocket will simply ignore writes of zero-length, and connection checking with AFSocket.checkConnectionClosed() may return false regardless of the actual condition.

CAPABILITY_UNSAFE

public static final AFSocketCapability CAPABILITY_UNSAFE

Support for "unsafe" operations. Trading-in safety for speed or simplicity may be justified sometimes.

See Also:

• Unsafe
• AFSocket.ensureUnsafeSupported()

CAPABILITY_LARGE_PORTS

public static final AFSocketCapability CAPABILITY_LARGE_PORTS

Support for port numbers larger than 65535 (0xffff). Not all systems allow setting port numbers beyond the default TCP range (we use JNI tricks for that). This capability is required for RMI support.

CAPABILITY_DARWIN

public static final AFSocketCapability CAPABILITY_DARWIN

Support for certain Darwin (macOS Kernel)-specific features, such as the AF_SYSTEM domain.

Method Details

values

public static AFSocketCapability[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static AFSocketCapability valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null