Hi,
SSHD client is timing out when input stream is passed to any remote program,
and pty has been enabled in the client. Apparently, the remote program doesn't
stop waiting on the input stream even after the input stream has been closed in
the client code. ( When pty is not enabled in the client, the code works
fine). The client finally times out and getExitStatus() returns null. I am
using Mina sshd client 2.5.1, and openssh server on RHEL 7. My test code is
given below. I am passing some input to the "cat" program on the server. cat is
expected to read the input and just send it back to the client:
/** start test code **/import java.io.ByteArrayInputStream;import
java.io.ByteArrayOutputStream;import java.io.InputStream;import
java.nio.file.Path;import java.nio.file.Paths;import
java.security.KeyPair;import java.util.EnumSet;
import java.util.Set;import java.util.concurrent.TimeUnit;
import org.apache.sshd.client.SshClient;import
org.apache.sshd.client.channel.ChannelExec;import
org.apache.sshd.client.channel.ClientChannelEvent;import
org.apache.sshd.client.session.ClientSession;
import org.apache.sshd.common.keyprovider.FileKeyPairProvider;
public class SshClientPtyTest {
public static void main(String[] args) throws Exception { final String HOST =
"a.b.c.d"; final int PORT = 22; final String KEYPATH =
"C:\\Users\\xyz\\.ssh\\id_rsa"; final String USER = "xyz";
int defaultTimeout = 30;
SshClient client = SshClient.setUpDefaultClient(); client.start(); try
(ClientSession session = client.connect(USER, HOST,
PORT).verify(defaultTimeout, TimeUnit.SECONDS) .getSession()) { Path keyLoc =
Paths.get(KEYPATH); FileKeyPairProvider keyPairProvider = new
FileKeyPairProvider(keyLoc); KeyPair keyPair =
keyPairProvider.loadKeys(null).iterator().next();
session.addPublicKeyIdentity(keyPair); session.auth().verify(defaultTimeout,
TimeUnit.SECONDS);
ByteArrayOutputStream bout = new ByteArrayOutputStream();
ByteArrayOutputStream berr = new ByteArrayOutputStream(); String contentToSend
= "Content be sent to remote command"; InputStream bins = new
ByteArrayInputStream(contentToSend.getBytes());
try (ChannelExec channel = session.createExecChannel("cat")) {
/** if setUsePty(false) then the issue disappears **/ channel.setUsePty(true);
channel.setOut(bout); channel.setErr(berr); channel.setIn(bins);
System.out.println("isUsePty() " + channel.isUsePty()); channel.open().verify();
Set<ClientChannelEvent> result =
channel.waitFor(EnumSet.of(ClientChannelEvent.EXIT_STATUS),
TimeUnit.SECONDS.toMillis(defaultTimeout)); System.out.println("Stdout: " +
bout + ", Stderr:" + berr); int es = channel.getExitStatus();
System.out.println("Exit Status: " + es);
} } finally { client.stop();
}
}
}/** end test code **/
I am new to Mina sshd, so very likely there is something wrong withe code
above, but I can't figure out what it is. Any help will be appreciated.
Thanks,Hari
