/servers/diameter/core/jdiameter/impl/src/main/java/org/jdiameter/server/impl/app/auth/ServerAuthSessionImpl.java

/*

 * JBoss, Home of Professional Open Source

 * Copyright 2006, Red Hat, Inc. and individual contributors

 * by the @authors tag. See the copyright.txt in the distribution for a

 * full listing of individual contributors.

 *

 * This is free software; you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This software is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this software; if not, write to the Free

 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.

 */



package org.jdiameter.server.impl.app.auth;



import static org.jdiameter.common.api.app.auth.ServerAuthSessionState.DISCONNECTED;

import static org.jdiameter.common.api.app.auth.ServerAuthSessionState.IDLE;

import static org.jdiameter.common.api.app.auth.ServerAuthSessionState.OPEN;

import static org.jdiameter.server.impl.app.auth.Event.Type.RECEIVE_ASR_ANSWER;

import static org.jdiameter.server.impl.app.auth.Event.Type.RECEIVE_AUTH_REQUEST;

import static org.jdiameter.server.impl.app.auth.Event.Type.TIMEOUT_EXPIRES;



import java.io.Serializable;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;



import org.jdiameter.api.Answer;

import org.jdiameter.api.EventListener;

import org.jdiameter.api.IllegalDiameterStateException;

import org.jdiameter.api.InternalException;

import org.jdiameter.api.NetworkReqListener;

import org.jdiameter.api.OverloadException;

import org.jdiameter.api.Request;

import org.jdiameter.api.RouteException;

import org.jdiameter.api.app.AppAnswerEvent;

import org.jdiameter.api.app.AppEvent;

import org.jdiameter.api.app.AppRequestEvent;

import org.jdiameter.api.app.AppSession;

import org.jdiameter.api.app.StateChangeListener;

import org.jdiameter.api.app.StateEvent;

import org.jdiameter.api.auth.ServerAuthSession;

import org.jdiameter.api.auth.ServerAuthSessionListener;

import org.jdiameter.api.auth.events.AbortSessionAnswer;

import org.jdiameter.api.auth.events.AbortSessionRequest;

import org.jdiameter.api.auth.events.ReAuthRequest;

import org.jdiameter.api.auth.events.SessionTermAnswer;

import org.jdiameter.api.auth.events.SessionTermRequest;

import org.jdiameter.client.api.ISessionFactory;

import org.jdiameter.common.api.app.IAppSessionState;

import org.jdiameter.common.api.app.auth.IAuthMessageFactory;

import org.jdiameter.common.api.app.auth.IServerAuthActionContext;

import org.jdiameter.common.api.app.auth.ServerAuthSessionState;

import org.jdiameter.common.impl.app.AppAnswerEventImpl;

import org.jdiameter.common.impl.app.auth.AbortSessionAnswerImpl;

import org.jdiameter.common.impl.app.auth.AbortSessionRequestImpl;

import org.jdiameter.common.impl.app.auth.AppAuthSessionImpl;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;



/**

 * Server Authorization session implementation

 * 

 * @author erick.svenson@yahoo.com

 * @author <a href="mailto:brainslog@gmail.com"> Alexandre Mendonca </a>

 * @author <a href="mailto:baranowb@gmail.com"> Bartosz Baranowski </a>

 */

public class ServerAuthSessionImpl extends AppAuthSessionImpl implements ServerAuthSession, EventListener<Request, Answer>, NetworkReqListener {



  private static final long serialVersionUID = 1L;



  protected static final Logger logger = LoggerFactory.getLogger(ServerAuthSessionImpl.class);



  protected IServerAuthSessionData sessionData;



  // Session State Handling ---------------------------------------------------

  private Lock sendAndStateLock = new ReentrantLock();



  // Factories and Listeners --------------------------------------------------

  protected transient IAuthMessageFactory factory;

  protected transient IServerAuthActionContext context;

  protected transient ServerAuthSessionListener listener;



  // Ts Timer -----------------------------------------------------------------

  protected final static String TIMER_NAME_TS="AUTH_TS";



  // Constructors -------------------------------------------------------------



  public ServerAuthSessionImpl(IServerAuthSessionData sessionData,ISessionFactory sf, ServerAuthSessionListener lst, IAuthMessageFactory fct, StateChangeListener<AppSession> scListener,IServerAuthActionContext context, long tsTimeout, boolean stateless) {

    super(sf,sessionData);  



    super.appId = fct.getApplicationId();

    this.listener = lst;

    this.factory = fct;

    this.context = context;

    this.sessionData = sessionData;

    this.sessionData.setStateless(stateless);

    this.sessionData.setTsTimeout(tsTimeout);

    super.addStateChangeNotification(scListener);

  }



  // ServerAuthSession Implementation methods ---------------------------------



  public void sendAuthAnswer(AppAnswerEvent appAnswerEvent) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(null, appAnswerEvent);

  }



  public void sendReAuthRequest(ReAuthRequest reAuthRequest) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(null, reAuthRequest);

  }



  public void sendAbortSessionRequest(AbortSessionRequest abortSessionRequest) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(Event.Type.SEND_ASR_REQUEST, abortSessionRequest);

  }



  public void sendSessionTerminationAnswer(SessionTermAnswer sessionTermAnswer) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(null, sessionTermAnswer);

  }



  protected void send(Event.Type type, AppEvent event) throws InternalException {

    try {

      sendAndStateLock.lock();

      if (type != null) {

        handleEvent(new Event(type, event));

      }

      session.send(event.getMessage(), this);

    }

    catch (Exception e) {

      throw new InternalException(e);

    }

    finally {

      sendAndStateLock.unlock();

    }

  }



  public boolean isStateless() {

    return sessionData.isStateless();

  }



  @SuppressWarnings("unchecked")

  protected void setState(ServerAuthSessionState newState) {

    IAppSessionState oldState = sessionData.getServerAuthSessionState();

    sessionData.setServerAuthSessionState(newState);

    for (StateChangeListener i : stateListeners) {

      i.stateChanged(this,(Enum) oldState, (Enum) newState);

    }

  }



  @SuppressWarnings("unchecked")

  public <E> E getState(Class<E> eClass) {

    return eClass == ServerAuthSessionState.class ? (E) sessionData.getServerAuthSessionState() : null;

  }



  public boolean handleEvent(StateEvent event) throws InternalException, OverloadException {

    return isStateless() ? handleEventForStatelessSession(event) : handleEventForStatefullSession(event);

  }



  public boolean handleEventForStatelessSession(StateEvent event) throws InternalException, OverloadException {

    try {

      switch (sessionData.getServerAuthSessionState()) {

      case IDLE:

        switch ((Event.Type) event.getType()) {

        case RECEIVE_AUTH_REQUEST:

          // Current State: IDLE

          // Event: Service-specific authorization request received, and successfully processed

          // Action: Send service specific answer

          // New State: IDLE

        	setState(IDLE);

          listener.doAuthRequestEvent(this, (AppRequestEvent) event.getData());

          break;

        default:

          logger.debug("Unknown event {}", event.getType());

          break;

        }

        break;

      }

    }

    catch (Throwable t) {

      throw new InternalException(t);

    }



    return true;

  }



  public boolean handleEventForStatefullSession(StateEvent event) throws InternalException, OverloadException {

    ServerAuthSessionState state = sessionData.getServerAuthSessionState(); 

    ServerAuthSessionState oldState = state;

    try {

      switch (state) {

      case IDLE: {

        switch ((Event.Type) event.getType()) {

        case RECEIVE_AUTH_REQUEST:

          try {

            // Current State: IDLE

            // Event: Service-specific authorization request received, and user is authorized

            // Action: Send successful service specific answer

            // New State: OPEN

        	  setState(OPEN);

            listener.doAuthRequestEvent(this, (AppRequestEvent) event.getData());

          }

          catch (Exception e) {

            setState(IDLE);

          }

          break;

        case RECEIVE_STR_REQUEST:

          try {

            // Current State: ANY

            // Event: STR Received

            // Action: Send STA, Cleanup

            // New State: IDLE

        	  setState(IDLE);

            listener.doSessionTerminationRequestEvent(this, (SessionTermRequest) event.getData());

          }

          catch (Exception e) {

            logger.debug("Can not handle event", e);

          }

          break;

        case SEND_ASR_REQUEST:

          setState(DISCONNECTED);

          break;

        case TIMEOUT_EXPIRES:

          if (context != null) {

            context.accessTimeoutElapses(this);

          }

          setState(IDLE);

          break;

        default:

          logger.debug("Unknown event {}", event.getType());

          break;

        }

        break;

      }

      case OPEN: {

        switch ((Event.Type) event.getType()) {

        case RECEIVE_AUTH_REQUEST:

          try {

            // Current State: OPEN

            // Event: Service-specific authorization request received, and user is authorized

            // Action: Send successful service specific answer

            // New State: OPEN

            listener.doAuthRequestEvent(this, (AppRequestEvent) event.getData());

          }

          catch (Exception e) {

            // Current State: OPEN

            // Event: Service-specific authorization request received, and user is not authorized

            // Action: Send failed service specific answer, Cleanup

            // New State: IDLE

            setState(IDLE);

          }

          break;

        case RECEIVE_STR_REQUEST:

          try {

            setState(IDLE);

            listener.doSessionTerminationRequestEvent(this, (SessionTermRequest) event.getData());

          }

          catch (Exception e) {

            logger.debug("Can not handle event", e);

          }

          break;

        case SEND_ASR_REQUEST:

          // Current State: OPEN

          // Event: Home server wants to terminate the service

          // Action: Send ASR

          // New State: DISCON

          setState(DISCONNECTED);

          break;

        case TIMEOUT_EXPIRES:

          // Current State: OPEN

          // Event: Authorization-Lifetime (and Auth-Grace-Period) expires on home server.

          // Action: Cleanup

          // New State: IDLE



          // Current State: OPEN

          // Event: Session-Timeout expires on home server

          // Action: Cleanup

          // New State: IDLE

          if (context != null) {

            context.accessTimeoutElapses(this);

          }

          setState(IDLE);

          break;

        default:

          logger.debug("Unknown event {}", event.getType());

          break;

        }

        break;

      }

      case DISCONNECTED: {

        switch ((Event.Type) event.getType()) {

        case SEND_ASR_FAILURE:

          // Current State: DISCON

          // Event: Failure to send ASR

          // Action: Wait, Re-send ASR

          // New State: DISCON

          setState(DISCONNECTED);

          break;

        case RECEIVE_ASR_ANSWER:

          // Current State: DISCON

          // Event: ASR successfully sent and ASA Received with Result-Code

          // Action: Cleanup

          // New State: IDLE

          setState(IDLE);

          listener.doAbortSessionAnswerEvent(this, (AbortSessionAnswer) event.getData());

          break;

        default:

          logger.debug("Unknown event {}", event.getType());

          break;

        }

        break;

      }

      default: {

        logger.debug("Unknown state {}", state);

        break;

      }

      }



      // post processing

      if (oldState != state) {

        if (OPEN.equals(state) && context != null) {

          if(context != null) {

            cancelTsTimer();

            startTsTimer();

          }

          //          scheduler.schedule(new Runnable() {

          //            public void run() {

          //              if (context != null) {

          //                try {

          //                  handleEvent(new Event(TIMEOUT_EXPIRES, null));

          //                }

          //                catch (Exception e) {

          //                  logger.debug("Can not handle event", e);

          //                }

          //              }

          //            }

          //          }, context.createAccessTimer(), TimeUnit.MILLISECONDS);

        }

      }

    }

    catch (Throwable t) {

      throw new InternalException(t);

    }



    return true;

  }



  public void receivedSuccessMessage(Request request, Answer answer) {

    AnswerDelivery rd = new AnswerDelivery();

    rd.session = this;

    rd.request = request;

    rd.answer = answer;

    super.scheduler.execute(rd);

  }



  public void timeoutExpired(Request request) {

    try {

      if (request.getCommandCode() == AbortSessionRequestImpl.code) {

        handleEvent(new Event(Event.Type.SEND_ASR_FAILURE, new AbortSessionRequestImpl(request)));

      }

      else {

        logger.debug("Timeout for unknown request {}", request);

      }

    }

    catch (Exception e) {

      logger.debug("Can not handle event", e);

    }

  }



  public Answer processRequest(Request request) {

    RequestDelivery rd = new RequestDelivery();

    rd.session = this;

    rd.request = request;

    super.scheduler.execute(rd);

    return null;

  }



  /* (non-Javadoc)

   * @see org.jdiameter.common.impl.app.AppSessionImpl#isReplicable()

   */

  @Override

  public boolean isReplicable() {

    return true;

  }



  protected void startTsTimer() {

    try {

      sendAndStateLock.lock();

      sessionData.setTsTimerId(super.timerFacility.schedule(sessionData.getSessionId(), TIMER_NAME_TS, sessionData.getTsTimeout()));

    }

    finally {

      sendAndStateLock.unlock();

    }

  }



  protected void cancelTsTimer() {

    try {

      sendAndStateLock.lock();

      Serializable tsTimerId = sessionData.getTsTimerId();

      if(tsTimerId != null) {

        super.timerFacility.cancel(tsTimerId);

        sessionData.setTsTimerId(null);

      }

    }

    finally {

      sendAndStateLock.unlock();

    }

  }



  /* (non-Javadoc)

   * @see org.jdiameter.common.impl.app.AppSessionImpl#onTimer(java.lang.String)

   */

  @Override

  public void onTimer(String timerName) {

    if(timerName.equals(TIMER_NAME_TS)) {

      try {

        sendAndStateLock.lock();

        sessionData.setTsTimerId(null);

        handleEvent(new Event(TIMEOUT_EXPIRES, null));

      }

      catch (Exception e) {

        logger.debug("Can not handle event", e);

      }

      finally {

        sendAndStateLock.unlock();

      }

    }

  }



  @Override

  public int hashCode() {

    final int prime = 31;

    int result = super.hashCode();

    result = prime * result + ((sessionData == null) ? 0 : sessionData.hashCode());

    return result;

  }



  @Override

  public boolean equals(Object obj) {

    if (this == obj)

      return true;

    if (!super.equals(obj))

      return false;

    if (getClass() != obj.getClass())

      return false;

    ServerAuthSessionImpl other = (ServerAuthSessionImpl) obj;

    if (sessionData == null) {

      if (other.sessionData != null)

        return false;

    }

    else if (!sessionData.equals(other.sessionData))

      return false;

    return true;

  }



  @Override

  public void release() {

    if (isValid()) {

      try {

        sendAndStateLock.lock();

        super.release();

        this.context = null;

        this.listener = null;

      }

      catch (Exception e) {

        logger.debug("Failed to release session", e);

      }

      finally {

        sendAndStateLock.unlock();

      }

    }

    else {

      logger.debug("Trying to release an already invalid session, with Session ID '{}'", getSessionId());

    }

  }



  private class RequestDelivery implements Runnable {

    ServerAuthSession session;

    Request request;



    public void run() {

      if (request != null) {

        if (request.getCommandCode() == factory.getAuthMessageCommandCode()) {

          try {

            sendAndStateLock.lock();

            handleEvent(new Event(RECEIVE_AUTH_REQUEST, factory.createAuthRequest(request)));

          }

          catch (Exception e) {

            logger.debug("Can not handle event", e);

          }

          finally {

            sendAndStateLock.unlock();

          }

        }

        else {

          try {

            listener.doOtherEvent(session, factory.createAuthRequest(request), null);

          }

          catch (Exception e) {

            logger.debug("Can not handle event", e);

          }

        }

      }

    }

  }



  private class AnswerDelivery implements Runnable {

    ServerAuthSession session;

    Answer answer;

    Request request;



    public void run() {

      try {

        sendAndStateLock.lock();

        if (request.getCommandCode() == factory.getAuthMessageCommandCode()) {

          handleEvent(new Event(RECEIVE_AUTH_REQUEST, factory.createAuthRequest(request)));

        }

        else if (request.getCommandCode() == AbortSessionRequestImpl.code) {

          handleEvent(new Event(RECEIVE_ASR_ANSWER, new AbortSessionAnswerImpl(answer)));

        }

        else {

          listener.doOtherEvent(session, factory.createAuthRequest(request), new AppAnswerEventImpl(answer));

        }

      }

      catch (Exception e) {

        logger.debug("Can not handle event", e);

      }

      finally {

        sendAndStateLock.unlock();

      }

    }

  }



}