/**
* Determines whether a vaild session exists for the contact of remote machine.
*
* @param sshContact ID of SSH Contact
* @return <tt>true</tt> if the session is connected <tt>false</tt> otherwise
*/
public boolean isSessionValid(ContactSSH sshContact) {
Session sshSession = sshContact.getSSHSession();
if (sshSession != null) if (sshSession.isConnected()) return true;
// remove reference to an unconnected SSH Session, if any
sshContact.setSSHSession(null);
return false;
}
/**
* Creates a shell channel to the remote machine a new jsch session is also created if the current
* one is invalid
*
* @param sshContact the contact of the remote machine
* @param firstMessage the first message
*/
public void connectShell(final ContactSSH sshContact, final Message firstMessage) {
sshContact.setConnectionInProgress(true);
final UIService uiService = this.uiService;
final Thread newConnection =
new Thread(
(new Runnable() {
public void run() {
OperationSetPersistentPresenceSSHImpl persistentPresence =
(OperationSetPersistentPresenceSSHImpl)
sshContact.getParentPresenceOperationSet();
persistentPresence.changeContactPresenceStatus(
sshContact, SSHStatusEnum.CONNECTING);
try {
if (!isSessionValid(sshContact)) createSSHSessionAndLogin(sshContact);
createShellChannel(sshContact);
// initalizing the reader and writers of ssh contact
persistentPresence.changeContactPresenceStatus(
sshContact, SSHStatusEnum.CONNECTED);
showWelcomeMessage(sshContact);
sshContact.setMessageType(sshContact.CONVERSATION_MESSAGE_RECEIVED);
sshContact.setConnectionInProgress(false);
Thread.sleep(1500);
sshContact.setCommandSent(true);
basicInstantMessaging.sendInstantMessage(sshContact, firstMessage);
}
// rigoruos Exception Checking in future
catch (Exception ex) {
persistentPresence.changeContactPresenceStatus(
sshContact, SSHStatusEnum.NOT_AVAILABLE);
ex.printStackTrace();
} finally {
sshContact.setConnectionInProgress(false);
}
}
}));
newConnection.start();
}
/**
* Determines whether the contact is connected to shell of remote machine as a precheck for any
* further operation
*
* @param sshContact ID of SSH Contact
* @return <tt>true</tt> if the contact is connected <tt>false</tt> if the contact is not
* connected
*/
public boolean isShellConnected(ContactSSH sshContact) {
// a test command may also be run here
if (isSessionValid(sshContact)) {
return (sshContact.getShellChannel() != null);
}
/*
* Above should be return(sshContact.getShellChannel() != null
* && sshContact.getShellChannel().isConnected());
*
* but incorrect reply from stack for isConnected()
*/
return false;
}
/**
* Creates a channel for shell type in the current session channel types = shell, sftp, exec(X
* forwarding), direct-tcpip(stream forwarding) etc
*
* @param sshContact ID of SSH Contact
*/
public void createShellChannel(ContactSSH sshContact) throws IOException {
try {
Channel shellChannel = sshContact.getSSHSession().openChannel("shell");
// initalizing the reader and writers of ssh contact
sshContact.initializeShellIO(shellChannel.getInputStream(), shellChannel.getOutputStream());
((ChannelShell) shellChannel)
.setPtyType(sshContact.getSSHConfigurationForm().getTerminalType());
// initializing the shell
shellChannel.connect(1000);
sshContact.setShellChannel(shellChannel);
sshContact.sendLine("export PS1=");
} catch (JSchException ex) {
sshContact.setSSHSession(null);
throw new IOException("Unable to create shell channel to remote" + " server");
}
}
/**
* Closes the SSH Session associated with the contact
*
* @param sshContact ID of SSH Contact
*/
void closeSSHSession(ContactSSH sshContact) {
sshContact.getSSHSession().disconnect();
sshContact.setSSHSession(null);
}
/**
* Creates a SSH Session with a remote machine and tries to login according to the details
* specified by Contact An appropriate message is shown to the end user in case the login fails
*
* @param sshContact ID of SSH Contact
* @throws JSchException if a JSch is unable to create a SSH Session with the remote machine
* @throws InterruptedException if the thread is interrupted before session connected or is timed
* out
* @throws OperationFailedException if not of above reasons :-)
*/
public void createSSHSessionAndLogin(ContactSSH sshContact)
throws JSchException, OperationFailedException, InterruptedException {
logger.info("Creating a new SSH Session to " + sshContact.getHostName());
// creating a new JSch Stack identifier for contact
JSch jsch = new JSch();
String knownHosts = (String) accountID.getAccountProperties().get("KNOWN_HOSTS_FILE");
if (!knownHosts.equals("Optional")) jsch.setKnownHosts(knownHosts);
String identitiyKey = (String) accountID.getAccountProperties().get("IDENTITY_FILE");
String userName = sshContact.getUserName();
// use the name of system user if the contact has not supplied SSH
// details
if (userName.equals("")) userName = System.getProperty("user.name");
if (!identitiyKey.equals("Optional")) jsch.addIdentity(identitiyKey);
// creating a new session for the contact
Session session =
jsch.getSession(
userName, sshContact.getHostName(), sshContact.getSSHConfigurationForm().getPort());
/**
* Creating and associating User Info with the session User Info passes authentication from
* sshContact to SSH Stack
*/
SSHUserInfo sshUserInfo = new SSHUserInfo(sshContact);
session.setUserInfo(sshUserInfo);
/** initializing the session */
session.connect(connectionTimeout);
int count = 0;
// wait for session to get connected
while (!session.isConnected() && count <= 30000) {
Thread.sleep(1000);
count += 1000;
logger.trace("SSH:" + sshContact.getHostName() + ": Sleep zzz .. ");
}
// if timeout have exceeded
if (count > 30000) {
sshContact.setSSHSession(null);
JOptionPane.showMessageDialog(
null, "SSH Connection attempt to " + sshContact.getHostName() + " timed out");
// error codes are not defined yet
throw new OperationFailedException(
"SSH Connection attempt to " + sshContact.getHostName() + " timed out", 2);
}
sshContact.setJSch(jsch);
sshContact.setSSHSession(session);
logger.info("A new SSH Session to " + sshContact.getHostName() + " Created");
}
/**
* Closes the Shell channel are associated IO Streams
*
* @param sshContact ID of SSH Contact
*/
public void closeShellChannel(ContactSSH sshContact) throws JSchException, IOException {
sshContact.closeShellIO();
sshContact.getShellChannel().disconnect();
sshContact.setShellChannel(null);
}