cms/org.argeo.slc.support/src/org/argeo/slc/jsch/AbstractJschTask.java

   1 package org.argeo.slc.jsch;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.security.PrivilegedAction;
   6
   7 import org.apache.commons.logging.Log;
   8 import org.apache.commons.logging.LogFactory;
   9 import org.argeo.slc.SlcException;
  10
  11 import com.jcraft.jsch.JSch;
  12 import com.jcraft.jsch.JSchException;
  13 import com.jcraft.jsch.Logger;
  14 import com.jcraft.jsch.Session;
  15 import com.jcraft.jsch.UserAuthGSSAPIWithMIC;
  16
  17 public abstract class AbstractJschTask implements Runnable {
  18         private final Log log = LogFactory.getLog(getClass());
  19
  20         private SshTarget sshTarget;
  21
  22         protected Session openSession() {
  23                 if (sshTarget.getSession() != null) {
  24                         Session session = sshTarget.getSession();
  25                         if (session.isConnected()) {
  26                                 if (log.isTraceEnabled())
  27                                         log.debug("Using cached session to " + getSshTarget() + " via SSH");
  28                                 return session;
  29                         }
  30                 }
  31
  32                 try {
  33                         JSch jsch = new JSch();
  34                         if (sshTarget.getUsePrivateKey() && sshTarget.getLocalPrivateKey().exists())
  35                                 jsch.addIdentity(sshTarget.getLocalPrivateKey().getAbsolutePath());
  36                         Session session = jsch.getSession(getSshTarget().getUser(), getSshTarget().getHost(),
  37                                         getSshTarget().getPort());
  38
  39                         session.setUserInfo(getSshTarget().getUserInfo());
  40                         session.setConfig("userauth.gssapi-with-mic", UserAuthGSSAPIWithMIC.class.getName());
  41                         session.setServerAliveInterval(1000);
  42                         session.connect();
  43                         if (log.isTraceEnabled())
  44                                 log.trace("Connected to " + getSshTarget() + " via SSH");
  45                         if (sshTarget.getSession() != null) {
  46                                 if (log.isTraceEnabled())
  47                                         log.trace("The cached session to " + getSshTarget() + " was disconnected and was reset.");
  48                                 sshTarget.setSession(session);
  49                         }
  50                         return session;
  51                 } catch (JSchException e) {
  52                         if (sshTarget.getUserInfo() instanceof SimpleUserInfo)
  53                                 ((SimpleUserInfo) sshTarget.getUserInfo()).reset();
  54                         throw new SlcException("Could not open session to " + getSshTarget(), e);
  55                 }
  56         }
  57
  58         public void run() {
  59                 Session session = openSession();
  60                 try {
  61                         run(session);
  62                 } finally {
  63                         if (sshTarget != null && sshTarget.getSession() == null) {
  64                                 session.disconnect();
  65                                 if (log.isTraceEnabled())
  66                                         log.trace("Disconnected from " + getSshTarget() + " via SSH");
  67                         }
  68                 }
  69         }
  70
  71         abstract void run(Session session);
  72
  73         protected int checkAck(InputStream in) throws IOException {
  74                 int b = in.read();
  75                 // b may be 0 for success,
  76                 // 1 for error,
  77                 // 2 for fatal error,
  78                 // -1
  79                 if (b == 0)
  80                         return b;
  81                 else if (b == -1)
  82                         return b;// throw new SlcException("SSH ack returned -1");
  83                 else if (b == 1 || b == 2) {
  84                         StringBuffer sb = new StringBuffer();
  85                         int c;
  86                         do {
  87                                 c = in.read();
  88                                 sb.append((char) c);
  89                         } while (c != '\n');
  90                         if (b == 1) { // error
  91                                 throw new SlcException("SSH ack error: " + sb.toString());
  92                         }
  93                         if (b == 2) { // fatal error
  94                                 throw new SlcException("SSH fatal error: " + sb.toString());
  95                         }
  96                 }
  97                 return b;
  98         }
  99
 100         public SshTarget getSshTarget() {
 101                 if (sshTarget == null)
 102                         throw new SlcException("No SSH target defined.");
 103                 return sshTarget;
 104         }
 105
 106         public void setSshTarget(SshTarget sshTarget) {
 107                 this.sshTarget = sshTarget;
 108         }
 109
 110         PrivilegedAction<Void> asPrivilegedAction() {
 111                 return new PrivilegedAction<Void>() {
 112                         public Void run() {
 113                                 AbstractJschTask.this.run();
 114                                 return null;
 115                         }
 116                 };
 117         }
 118
 119         static {
 120                 JSch.setLogger(new JschLogger());
 121         }
 122
 123         private static class JschLogger implements Logger {
 124                 private final Log log = LogFactory.getLog(JschLogger.class);
 125
 126                 // TODO better support levels
 127                 @Override
 128                 public boolean isEnabled(int level) {
 129                         if (log.isTraceEnabled())
 130                                 return true;
 131                         return false;
 132                 }
 133
 134                 @Override
 135                 public void log(int level, String message) {
 136                         log.trace(message);
 137                 }
 138
 139         }
 140 }