net.i2p.i2ptunnel

Class I2PTunnelServer

java.lang.Object

net.i2p.util.EventDispatcherImpl

net.i2p.i2ptunnel.I2PTunnelTask

net.i2p.i2ptunnel.I2PTunnelServer

All Implemented Interfaces:

Runnable, EventDispatcher

Direct Known Subclasses:

I2PTunnelDCCServer, I2PTunnelHTTPServer, I2PTunnelIRCServer

public class I2PTunnelServer
extends I2PTunnelTask
implements Runnable

Base I2P tunnel server for handling incoming connections.

I2PTunnelServer is the foundation for all I2P server tunnels that accept incoming I2P connections and forward them to local TCP services. It manages the lifecycle of I2PSocketManager, handles connection acceptance, and provides connection forwarding to configured local destinations.

Key Features:

• Accepts incoming I2P connections via I2PServerSocket
• Forwards connections to configurable local TCP destinations
• Supports SSL/TLS connections via I2PSSLSocketFactory
• Provides port-based destination mapping (targetForPort.xx)
• Implements connection filtering via StatefulConnectionFilter
• Uses thread pool for concurrent connection handling

Connection Flow:

1. Client connects to I2P destination via I2PServerSocket
2. blockingHandle() is called with the I2PSocket
3. Local TCP socket is created via getSocket()
4. I2PTunnelRunner handles bidirectional data streaming

Subclasses: I2PTunnelHTTPServer, I2PTunnelIRCServer, and others extend this class to provide protocol-specific handling while reusing the core connection management infrastructure.

See Also:

I2PTunnelHTTPServer, I2PTunnelIRCServer, I2PSocketManager

Field Summary

Fields

Modifier and Type	Field and Description
protected static long	__serverId
protected ThreadPoolExecutor	_clientExecutor
protected Log	_log
protected boolean	bidir
protected I2PServerSocket	i2pss
protected Logging	l
protected int	localPort
static String	PROP_ALT_PKF
static String	PROP_UNIQUE_LOCAL
static String	PROP_USE_SSL
protected long	readTimeout default timeout - override if desired
protected InetAddress	remoteHost
protected int	remotePort
protected Object	slock
protected I2PSocketManager	sockMgr
protected Object	sslLock
protected I2PTunnelTask	task

Fields inherited from class net.i2p.i2ptunnel.I2PTunnelTask

open, tunnel

Constructor Summary

Constructors

Constructor and Description
I2PTunnelServer(InetAddress host, int port, File privkey, String privkeyname, Logging l, EventDispatcher notifyThis, I2PTunnel tunnel) Non-blocking
I2PTunnelServer(InetAddress host, int port, I2PSocketManager sktMgr, Logging l, EventDispatcher notifyThis, I2PTunnel tunnel) Non-blocking
I2PTunnelServer(InetAddress host, int port, InputStream privData, String privkeyname, Logging l, EventDispatcher notifyThis, I2PTunnel tunnel) Non-blocking
I2PTunnelServer(InetAddress host, int port, String privData, Logging l, EventDispatcher notifyThis, I2PTunnel tunnel) Non-blocking

Method Summary

Modifier and Type	Method and Description
protected void	blockingHandle(I2PSocket socket) This is run in a thread from a limited-size thread pool via Handler.run(), except for a standard server (this class, no extension, as determined in getUsePool()), it is run directly in the acceptor thread (see run()).
boolean	close(boolean forced) Note that the tunnel can be reopened after this by calling startRunning().
boolean	destroy() Note that the tunnel cannot be reopened after this by calling startRunning(), as it will destroy the underlying socket manager.
long	getReadTimeout() Get the read idle timeout for newly-created connections (in milliseconds).
protected Socket	getSocket(Hash from, InetAddress remoteHost, int remotePort) Creates a TCP socket connection to the specified destination.
protected Socket	getSocket(Hash from, int incomingPort) Creates a TCP socket connection to the configured destination.
protected String	getSocketString(int incomingPort) Gets a human-readable string representation of the target socket.
void	optionsUpdated(I2PTunnel tunnel) Update the I2PSocketManager.
void	run() Runs the I2PTunnelServer to accept and handle incoming connections asynchronously.
void	setReadTimeout(long ms) Set the read idle timeout for newly-created connections (in milliseconds).
(package private) void	shutdownAndAwaitTermination(ExecutorService executor)
void	startRunning() Start running the I2PTunnelServer.

Methods inherited from class net.i2p.i2ptunnel.I2PTunnelTask

connected, disconnected, errorOccurred, getBooleanOption, getId, getTunnel, isOpen, reportAbuse, routerDisconnected, setId, setName, setTunnel, toString

Methods inherited from class net.i2p.util.EventDispatcherImpl

attachEventDispatcher, detachEventDispatcher, getEventDispatcher, getEvents, getEventValue, ignoreEvents, notifyEvent, unIgnoreEvents, waitEventValue

Methods inherited from class java.lang.Object

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

Field Detail

__serverId

protected static volatile long __serverId

_clientExecutor

protected volatile ThreadPoolExecutor _clientExecutor

_log

protected final Log _log

bidir

protected boolean bidir

i2pss

protected volatile I2PServerSocket i2pss

l

protected final Logging l

localPort

protected int localPort

PROP_ALT_PKF

public static final String PROP_ALT_PKF

See Also:

Constant Field Values

PROP_UNIQUE_LOCAL

public static final String PROP_UNIQUE_LOCAL

See Also:

Constant Field Values

PROP_USE_SSL

public static final String PROP_USE_SSL

See Also:

Constant Field Values

readTimeout

protected long readTimeout

default timeout - override if desired

remoteHost

protected InetAddress remoteHost

remotePort

protected int remotePort

slock

protected final Object slock

sockMgr

protected final I2PSocketManager sockMgr

sslLock

protected final Object sslLock

task

protected I2PTunnelTask task

Constructor Detail

I2PTunnelServer

public I2PTunnelServer(InetAddress host,
                       int port,
                       File privkey,
                       String privkeyname,
                       Logging l,
                       EventDispatcher notifyThis,
                       I2PTunnel tunnel)

Non-blocking

Parameters:

privkey - file containing the private key data, format is specified in PrivateKeyFile

privkeyname - the name of the privKey file, just for logging

Throws:

IllegalArgumentException - if the I2CP configuration is b0rked so badly that we cant create a socketManager

I2PTunnelServer

public I2PTunnelServer(InetAddress host,
                       int port,
                       I2PSocketManager sktMgr,
                       Logging l,
                       EventDispatcher notifyThis,
                       I2PTunnel tunnel)

Non-blocking

Parameters:

sktMgr - the existing socket manager

I2PTunnelServer

public I2PTunnelServer(InetAddress host,
                       int port,
                       InputStream privData,
                       String privkeyname,
                       Logging l,
                       EventDispatcher notifyThis,
                       I2PTunnel tunnel)

Non-blocking

Parameters:

privData - stream containing the private key data, format is specified in PrivateKeyFile

privkeyname - the name of the privKey file, just for logging

Throws:

IllegalArgumentException - if the I2CP configuration is b0rked so badly that we cant create a socketManager

I2PTunnelServer

public I2PTunnelServer(InetAddress host,
                       int port,
                       String privData,
                       Logging l,
                       EventDispatcher notifyThis,
                       I2PTunnel tunnel)

Non-blocking

Parameters:

privData - Base64-encoded private key data, format is specified in PrivateKeyFile

Throws:

IllegalArgumentException - if the I2CP configuration is b0rked so badly that we cant create a socketManager

Method Detail

blockingHandle

protected void blockingHandle(I2PSocket socket)

This is run in a thread from a limited-size thread pool via Handler.run(), except for a standard server (this class, no extension, as determined in getUsePool()), it is run directly in the acceptor thread (see run()). Handles an incoming I2P connection by forwarding it to the local TCP destination.

This method is called by the server socket's acceptance thread when a new I2P connection arrives. It creates a local TCP socket connection and spawns an I2PTunnelRunner to handle bidirectional data streaming between the I2P and TCP connections.

Implementation Notes:

• Subclasses that override this must call super.blockingHandle() or implement
full connection handling themselves
• For protocol-specific handling (HTTP, IRC), spawn a handler thread and return
• For simple forwarding, this base implementation handles all cases
• Performance: local connections are fast enough to handle synchronously

Error Handling: SocketException and IOException are caught and logged, with the socket being reset to notify the peer of the failure.

Parameters:

socket - the incoming I2P connection from a remote peer; never null

See Also:

getSocket(Hash, int), I2PTunnelRunner

close

public boolean close(boolean forced)

Note that the tunnel can be reopened after this by calling startRunning(). This does not release all resources. In particular, the I2PSocketManager remains and it may have timer threads that continue running. To release all resources permanently, call destroy().

Specified by:

close in class I2PTunnelTask

Returns:

true if the tunnel was closed successfully, false if connections exist and forced is false

destroy

public boolean destroy()

Note that the tunnel cannot be reopened after this by calling startRunning(), as it will destroy the underlying socket manager. This releases all resources.

Overrides:

destroy in class I2PTunnelTask

Returns:

success

getReadTimeout

public long getReadTimeout()

Get the read idle timeout for newly-created connections (in milliseconds). Less than or equal to 0 means forever. Default -1 (forever) as of 0.9.36 for standard tunnels, but extending classes may override. Prior to that, default was 5 minutes, but did not work due to streaming bugs.

Returns:

The read timeout used for connections

getSocket

protected Socket getSocket(Hash from,
                           InetAddress remoteHost,
                           int remotePort)
                    throws IOException

Creates a TCP socket connection to the specified destination.

This convenience method delegates to getSocket() with forceNonSSL=false, allowing SSL configuration to be controlled by client options.

Parameters:

from - the hash of the peer's destination

remoteHost - the target InetAddress to connect to

remotePort - the target port to connect to

Returns:

a connected TCP Socket

Throws:

IOException - if the socket cannot be created or connected

See Also:

getSocket(Hash, int)

getSocket

protected Socket getSocket(Hash from,
                           int incomingPort)
                    throws IOException

Creates a TCP socket connection to the configured destination.

This method resolves the target host and port for the incoming connection, supporting port-based destination mapping via the client options. If a port has a specific mapping (targetForPort.xx=host:port), that destination is used; otherwise, the default remoteHost and remotePort are used.

Port Mapping Configuration:

 targetForPort.80=localhost:8080
 targetForPort.443=localhost:8443
 

Special Ports: Ports 443 and 22 are automatically flagged for non-SSL handling to prevent SSL-over-SSL issues.

Parameters:

from - the hash of the peer's destination; used for local address binding

incomingPort - the port on which the I2P connection was received

Returns:

a connected TCP Socket to the appropriate local destination

Throws:

IOException - if the socket cannot be created or connected

See Also:

getSocket(Hash, InetAddress, int)

getSocketString

protected String getSocketString(int incomingPort)

Gets a human-readable string representation of the target socket.

This method is used for logging and error messages when socket creation fails. It returns the configured destination address, taking into account any port-specific mappings that may have been configured.

The returned string is formatted as "host:port" without any protocol prefix.

Parameters:

incomingPort - the incoming I2P connection port for lookup

Returns:

the target host and port as a string, or default if not configured

See Also:

getSocket(Hash, int)

optionsUpdated

public void optionsUpdated(I2PTunnel tunnel)

Update the I2PSocketManager. And since 0.9.15, the target host and port.

Overrides:

optionsUpdated in class I2PTunnelTask

run

public void run()

Runs the I2PTunnelServer to accept and handle incoming connections asynchronously. Accepts connections in a loop, submitting each to the thread pool via CompletableFuture. Handles expected exceptions with retries and logs errors. On shutdown, gracefully terminates the pool.

Specified by:

run in interface Runnable

setReadTimeout

public void setReadTimeout(long ms)

Set the read idle timeout for newly-created connections (in milliseconds). After this time expires without data being reached from the I2P network, the connection itself will be closed. Less than or equal to 0 means forever. Default -1 (forever) as of 0.9.36 for standard tunnels, but extending classes may override. Prior to that, default was 5 minutes, but did not work due to streaming bugs. Applies only to future connections; calling this does not affect existing connections.

Parameters:

ms - in ms

shutdownAndAwaitTermination

void shutdownAndAwaitTermination(ExecutorService executor)

startRunning

public void startRunning()

Start running the I2PTunnelServer. Warning, blocks while connecting to router and building tunnels;

Throws:

IllegalArgumentException - if the I2CP configuration is b0rked so badly that we cant create a socketManager