/*
* ConnectBot: simple, powerful, open-source SSH client for Android
* Copyright 2007 Kenny Root, Jeffrey Sharkey
*
* Licensed 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 com.trilead.ssh2.channel;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.net.ConnectException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NoRouteToHostException;
import java.net.ServerSocket;
import java.net.Socket;
import net.sourceforge.jsocks.Proxy;
import net.sourceforge.jsocks.ProxyMessage;
import net.sourceforge.jsocks.Socks4Message;
import net.sourceforge.jsocks.Socks5Message;
import net.sourceforge.jsocks.SocksException;
import net.sourceforge.jsocks.server.ServerAuthenticator;
import net.sourceforge.jsocks.server.ServerAuthenticatorNone;
/**
* DynamicAcceptThread.
*
* @author Kenny Root
* @version $Id$
*/
public class DynamicAcceptThread extends Thread implements IChannelWorkerThread {
private ChannelManager cm;
private ServerSocket ss;
class DynamicAcceptRunnable implements Runnable {
private static final int idleTimeout = 180000; //3 minutes
private ServerAuthenticator auth;
private Socket sock;
private InputStream in;
private OutputStream out;
private ProxyMessage msg;
public DynamicAcceptRunnable(ServerAuthenticator auth, Socket sock) {
this.auth = auth;
this.sock = sock;
setName("DynamicAcceptRunnable");
}
public void run() {
try {
startSession();
} catch (IOException ioe) {
int error_code = Proxy.SOCKS_FAILURE;
if (ioe instanceof SocksException)
error_code = ((SocksException) ioe).errCode;
else if (ioe instanceof NoRouteToHostException)
error_code = Proxy.SOCKS_HOST_UNREACHABLE;
else if (ioe instanceof ConnectException)
error_code = Proxy.SOCKS_CONNECTION_REFUSED;
else if (ioe instanceof InterruptedIOException)
error_code = Proxy.SOCKS_TTL_EXPIRE;
if (error_code > Proxy.SOCKS_ADDR_NOT_SUPPORTED
|| error_code < 0) {
error_code = Proxy.SOCKS_FAILURE;
}
sendErrorMessage(error_code);
} finally {
if (auth != null)
auth.endSession();
}
}
private ProxyMessage readMsg(InputStream in) throws IOException {
PushbackInputStream push_in;
if (in instanceof PushbackInputStream)
push_in = (PushbackInputStream) in;
else
push_in = new PushbackInputStream(in);
int version = push_in.read();
push_in.unread(version);
ProxyMessage msg;
if (version == 5) {
msg = new Socks5Message(push_in, false);
} else if (version == 4) {
msg = new Socks4Message(push_in, false);
} else {
throw new SocksException(Proxy.SOCKS_FAILURE);
}
return msg;
}
private void sendErrorMessage(int error_code) {
ProxyMessage err_msg;
if (msg instanceof Socks4Message)
err_msg = new Socks4Message(Socks4Message.REPLY_REJECTED);
else
err_msg = new Socks5Message(error_code);
try {
err_msg.write(out);
} catch (IOException ioe) {
}
}
private void handleRequest(ProxyMessage msg) throws IOException {
if (!auth.checkRequest(msg))
throw new SocksException(Proxy.SOCKS_FAILURE);
switch (msg.command) {
case Proxy.SOCKS_CMD_CONNECT:
onConnect(msg);
break;
default:
throw new SocksException(Proxy.SOCKS_CMD_NOT_SUPPORTED);
}
}
private void startSession() throws IOException {
sock.setSoTimeout(idleTimeout);
try {
auth = auth.startSession(sock);
} catch (IOException ioe) {
System.out.println("Could not start SOCKS session");
ioe.printStackTrace();
auth = null;
return;
}
if (auth == null) { // Authentication failed
System.out.println("SOCKS auth failed");
return;
}
in = auth.getInputStream();
out = auth.getOutputStream();
msg = readMsg(in);
handleRequest(msg);
}
private void onConnect(ProxyMessage msg) throws IOException {
ProxyMessage response = null;
Channel cn = null;
StreamForwarder r2l = null;
StreamForwarder l2r = null;
if (msg instanceof Socks5Message) {
response = new Socks5Message(Proxy.SOCKS_SUCCESS, (InetAddress)null, 0);
} else {
response = new Socks4Message(Socks4Message.REPLY_OK, (InetAddress)null, 0);
}
response.write(out);
String destHost = msg.host;
if (msg.ip != null)
destHost = msg.ip.getHostAddress();
try {
/*
* This may fail, e.g., if the remote port is closed (in
* optimistic terms: not open yet)
*/
cn = cm.openDirectTCPIPChannel(destHost, msg.port,
"127.0.0.1", 0);
} catch (IOException e) {
/*
* Simply close the local socket and wait for the next incoming
* connection
*/
try {
sock.close();
} catch (IOException ignore) {
}
return;
}
try {
r2l = new StreamForwarder(cn, null, null, cn.stdoutStream, out, "RemoteToLocal");
l2r = new StreamForwarder(cn, r2l, sock, in, cn.stdinStream, "LocalToRemote");
} catch (IOException e) {
try {
/*
* This message is only visible during debugging, since we
* discard the channel immediatelly
*/
cn.cm.closeChannel(cn,
"Weird error during creation of StreamForwarder ("
+ e.getMessage() + ")", true);
} catch (IOException ignore) {
}
return;
}
r2l.setDaemon(true);
l2r.setDaemon(true);
r2l.start();
l2r.start();
}
}
public DynamicAcceptThread(ChannelManager cm, int local_port)
throws IOException {
this.cm = cm;
setName("DynamicAcceptThread");
ss = new ServerSocket(local_port);
}
public DynamicAcceptThread(ChannelManager cm, InetSocketAddress localAddress)
throws IOException {
this.cm = cm;
ss = new ServerSocket();
ss.bind(localAddress);
}
@Override
public void run() {
try {
cm.registerThread(this);
} catch (IOException e) {
stopWorking();
return;
}
while (true) {
Socket sock = null;
try {
sock = ss.accept();
} catch (IOException e) {
stopWorking();
return;
}
DynamicAcceptRunnable dar = new DynamicAcceptRunnable(new ServerAuthenticatorNone(), sock);
Thread t = new Thread(dar);
t.setDaemon(true);
t.start();
}
}
/*
* (non-Javadoc)
*
* @see com.trilead.ssh2.channel.IChannelWorkerThread#stopWorking()
*/
public void stopWorking() {
try {
/* This will lead to an IOException in the ss.accept() call */
ss.close();
} catch (IOException e) {
}
}
}