Clarify SLC project structure.

[gpl/argeo-slc.git] / cms / org.argeo.slc.support / src / org / argeo / slc / jsch / AbstractJschTask.java

diff --git a/cms/org.argeo.slc.support/src/org/argeo/slc/jsch/AbstractJschTask.java b/cms/org.argeo.slc.support/src/org/argeo/slc/jsch/AbstractJschTask.java
new file mode 100644 (file)
index 0000000..59c0acf
--- /dev/null
+++ b/cms/org.argeo.slc.support/src/org/argeo/slc/jsch/AbstractJschTask.java
@@ -0,0 +1,140 @@
+package org.argeo.slc.jsch;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.security.PrivilegedAction;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.argeo.slc.SlcException;
+
+import com.jcraft.jsch.JSch;
+import com.jcraft.jsch.JSchException;
+import com.jcraft.jsch.Logger;
+import com.jcraft.jsch.Session;
+import com.jcraft.jsch.UserAuthGSSAPIWithMIC;
+
+public abstract class AbstractJschTask implements Runnable {
+       private final Log log = LogFactory.getLog(getClass());
+
+       private SshTarget sshTarget;
+
+       protected Session openSession() {
+               if (sshTarget.getSession() != null) {
+                       Session session = sshTarget.getSession();
+                       if (session.isConnected()) {
+                               if (log.isTraceEnabled())
+                                       log.debug("Using cached session to " + getSshTarget() + " via SSH");
+                               return session;
+                       }
+               }
+
+               try {
+                       JSch jsch = new JSch();
+                       if (sshTarget.getUsePrivateKey() && sshTarget.getLocalPrivateKey().exists())
+                               jsch.addIdentity(sshTarget.getLocalPrivateKey().getAbsolutePath());
+                       Session session = jsch.getSession(getSshTarget().getUser(), getSshTarget().getHost(),
+                                       getSshTarget().getPort());
+
+                       session.setUserInfo(getSshTarget().getUserInfo());
+                       session.setConfig("userauth.gssapi-with-mic", UserAuthGSSAPIWithMIC.class.getName());
+                       session.setServerAliveInterval(1000);
+                       session.connect();
+                       if (log.isTraceEnabled())
+                               log.trace("Connected to " + getSshTarget() + " via SSH");
+                       if (sshTarget.getSession() != null) {
+                               if (log.isTraceEnabled())
+                                       log.trace("The cached session to " + getSshTarget() + " was disconnected and was reset.");
+                               sshTarget.setSession(session);
+                       }
+                       return session;
+               } catch (JSchException e) {
+                       if (sshTarget.getUserInfo() instanceof SimpleUserInfo)
+                               ((SimpleUserInfo) sshTarget.getUserInfo()).reset();
+                       throw new SlcException("Could not open session to " + getSshTarget(), e);
+               }
+       }
+
+       public void run() {
+               Session session = openSession();
+               try {
+                       run(session);
+               } finally {
+                       if (sshTarget != null && sshTarget.getSession() == null) {
+                               session.disconnect();
+                               if (log.isTraceEnabled())
+                                       log.trace("Disconnected from " + getSshTarget() + " via SSH");
+                       }
+               }
+       }
+
+       abstract void run(Session session);
+
+       protected int checkAck(InputStream in) throws IOException {
+               int b = in.read();
+               // b may be 0 for success,
+               // 1 for error,
+               // 2 for fatal error,
+               // -1
+               if (b == 0)
+                       return b;
+               else if (b == -1)
+                       return b;// throw new SlcException("SSH ack returned -1");
+               else if (b == 1 || b == 2) {
+                       StringBuffer sb = new StringBuffer();
+                       int c;
+                       do {
+                               c = in.read();
+                               sb.append((char) c);
+                       } while (c != '\n');
+                       if (b == 1) { // error
+                               throw new SlcException("SSH ack error: " + sb.toString());
+                       }
+                       if (b == 2) { // fatal error
+                               throw new SlcException("SSH fatal error: " + sb.toString());
+                       }
+               }
+               return b;
+       }
+
+       public SshTarget getSshTarget() {
+               if (sshTarget == null)
+                       throw new SlcException("No SSH target defined.");
+               return sshTarget;
+       }
+
+       public void setSshTarget(SshTarget sshTarget) {
+               this.sshTarget = sshTarget;
+       }
+
+       PrivilegedAction<Void> asPrivilegedAction() {
+               return new PrivilegedAction<Void>() {
+                       public Void run() {
+                               AbstractJschTask.this.run();
+                               return null;
+                       }
+               };
+       }
+
+       static {
+               JSch.setLogger(new JschLogger());
+       }
+
+       private static class JschLogger implements Logger {
+               private final Log log = LogFactory.getLog(JschLogger.class);
+
+               // TODO better support levels
+               @Override
+               public boolean isEnabled(int level) {
+                       if (log.isTraceEnabled())
+                               return true;
+                       return false;
+               }
+
+               @Override
+               public void log(int level, String message) {
+                       log.trace(message);
+               }
+
+       }
+}