I am using mina sshd version 0.2.0.
I created a simple main, and sftp command factory and command and tried to
connect to my daemon with my OS X command line sftp client, and a few other
graphical clients and it all ends the same way. With a NPE in the
ChannelSession.doWriteData line 260. After debugging through the code the
SFTP commands come in with a subsystem type, when that happens the shellIn
and shellOut streams in ChannelSession remain null hence the NPE. I have
included the stack trace as well as my classes to demonstrate the issue.
2009-11-11 08:50:45,710 [NioProcessor-2] WARN
org.apache.sshd.server.session.ServerSession - Exception caught
java.lang.NullPointerException
at
org.apache.sshd.server.channel.ChannelSession.doWriteData(ChannelSession.java:260)
at
org.apache.sshd.common.channel.AbstractChannel.handleData(AbstractChannel.java:116)
at
org.apache.sshd.common.session.AbstractSession.channelData(AbstractSession.java:863)
at
org.apache.sshd.server.session.ServerSession.handleMessage(ServerSession.java:195)
at
org.apache.sshd.common.session.AbstractSession.decode(AbstractSession.java:490)
at
org.apache.sshd.common.session.AbstractSession.messageReceived(AbstractSession.java:214)
at
org.apache.sshd.common.AbstractSessionIoHandler.messageReceived(AbstractSessionIoHandler.java:58)
at
org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:721)
at
org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:433)
at
org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:47)
at
org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:801)
at
org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:119)
at
org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:433)
at
org.apache.mina.core.filterchain.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:425)
at
org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:603)
at
org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:563)
at
org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:552)
at
org.apache.mina.core.polling.AbstractPollingIoProcessor.access$400(AbstractPollingIoProcessor.java:56)
at
org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:891)
at
org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:637)
====================================================
import org.apache.sshd.SshServer;
import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider;
import org.apache.sshd.util.BogusPasswordAuthenticator;
import org.apache.sshd.util.EchoShellFactory;
public class Sftpd {
public static void main(String[] args) throws IOException {
SshServer sshd = SshServer.setUpDefaultServer();
sshd.setKeyPairProvider(new
SimpleGeneratorHostKeyProvider("hostkey.ser"));
sshd.setPasswordAuthenticator(new BogusPasswordAuthenticator());
sshd.setShellFactory(new EchoShellFactory());
// sshd.setShellFactory(new ProcessShellFactory(new String[] {
"/bin/sh", "-i", "-l" }));
sshd.setPort(2222);
sshd.setCommandFactory(new SftpCommandFactory());
sshd.start();
}
}
======================================================
import org.apache.sshd.server.CommandFactory;
import org.apache.sshd.server.command.UnknownCommand;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SftpCommandFactory implements CommandFactory {
private final Logger log =
LoggerFactory.getLogger(SftpCommandFactory.class);
public Command createCommand(String command) {
log.info("SFtP: "+command);
String[] args = command.split(" ");
if (args.length > 0 && "sftp".equals(args[0])) return new
SftpCommand(args);
return new UnknownCommand(command);
}
}
==============================================================
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.sshd.server.CommandFactory;
import org.apache.sshd.server.CommandFactory.ExitCallback;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SftpCommand implements CommandFactory.Command, Runnable {
private final Logger log = LoggerFactory.getLogger(SftpCommand.class);
private OutputStream err;
private ExitCallback callBack;
private InputStream in;
private OutputStream out;
private IOException error;
public SftpCommand(String[] args) {
log.info("sftp args: "+args);
}
public void setErrorStream(OutputStream err) {
}
public void setExitCallback(ExitCallback callback) {
}
public void setInputStream(InputStream in) {
}
public void setOutputStream(OutputStream out) {
}
public void start() throws IOException {
if (error != null) {
throw error;
}
new Thread(this).start();
}
public void run() {
callBack.onExit(0);
}
}
