/servers/diameter/core/jdiameter/impl/src/main/java/org/jdiameter/client/impl/app/gq/GqClientSessionImpl.java

/*

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 * Copyright 2011, 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.client.impl.app.gq;



import static org.jdiameter.api.Message.SESSION_TERMINATION_REQUEST;

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

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

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

import static org.jdiameter.common.api.app.auth.ClientAuthSessionState.PENDING;



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.Avp;

import org.jdiameter.api.AvpSet;

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.gq.GqClientSession;

import org.jdiameter.api.auth.ClientAuthSessionListener;

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

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

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

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.ClientAuthSessionState;

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

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

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

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

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.jdiameter.common.impl.app.auth.ReAuthAnswerImpl;

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

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

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

import org.jdiameter.client.impl.app.auth.IClientAuthSessionData;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;



/**

 * Client Gq Application session implementation

 * 

 * @author <a href="mailto:webdev@web-ukraine.info"> Yulian Oifa </a>

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

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

 */

public class GqClientSessionImpl extends AppAuthSessionImpl implements GqClientSession, EventListener<Request, Answer>, NetworkReqListener {



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



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

  protected Lock sendAndStateLock = new ReentrantLock();



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

  protected transient IAuthMessageFactory factory;

  protected transient IClientAuthActionContext context;

  protected transient ClientAuthSessionListener listener;



  protected static final String TIMER_NAME_TS = "GQ_TS";

  protected IClientAuthSessionData sessionData;



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



  public GqClientSessionImpl(IClientAuthSessionData sessionData,ISessionFactory sf,ClientAuthSessionListener lst, IAuthMessageFactory fct, StateChangeListener<AppSession> scListener,IClientAuthActionContext context,  boolean stateless) {

    super(sf, sessionData);

    if (lst == null) {

      throw new IllegalArgumentException("Listener can not be null");

    }

    if (fct.getApplicationId() == null) {

      throw new IllegalArgumentException("ApplicationId can not be null");

    }

    super.appId = fct.getApplicationId();

    this.listener = lst;

    this.factory = fct;

    this.context = context;

    this.sessionData = sessionData;

    this.sessionData.setStateless(stateless);

    super.addStateChangeNotification(scListener);

  }



  // ClientAuthSession Implementation methods ---------------------------------



  public void sendAbortSessionAnswer(AbortSessionAnswer answer) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(Event.Type.SEND_SESSION_ABORT_ANSWER, answer);

  }



  public void sendAuthRequest(AppRequestEvent request) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(Event.Type.SEND_AUTH_REQUEST, request);

  }



  public void sendReAuthAnswer(ReAuthAnswer answer) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(Event.Type.SEND_AUTH_ANSWER, answer);

  }



  public void sendSessionTerminationRequest(SessionTermRequest request) throws InternalException, IllegalDiameterStateException, RouteException, OverloadException {

    send(Event.Type.SEND_SESSION_TERMINATION_REQUEST, request);

  }



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

    //This is called from app thread, it may be due to callback from our delivery thread, but we dont care

    try {

      sendAndStateLock.lock();

      if (type != null) {

        handleEvent(new Event(type, event));

      }

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

      // Store last destination information

      AvpSet avps = event.getMessage().getAvps();

      Avp destRealmAvp = avps.getAvp(Avp.DESTINATION_REALM);

      if(destRealmAvp != null) {

        sessionData.setDestinationRealm(destRealmAvp.getDiameterIdentity());

      }

      Avp destHostAvp = avps.getAvp(Avp.DESTINATION_HOST);

      if(destHostAvp != null) {

        sessionData.setDestinationHost(destHostAvp.getDiameterIdentity());

      }

    }

    catch (Exception e) {

      throw new InternalException(e);

    }

    finally {

      sendAndStateLock.unlock();

    }

  }



  public boolean isStateless() {

    return this.sessionData.isStateless();

  }



  @SuppressWarnings("unchecked")

  protected void setState(ClientAuthSessionState newState) {

    IAppSessionState oldState = sessionData.getClientAuthSessionState();

    sessionData.setClientAuthSessionState(newState);

    for (StateChangeListener i : stateListeners) {

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

    }

  }



  @SuppressWarnings("unchecked")

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

    return eClass == ClientAuthSessionState.class ? (E) sessionData.getClientAuthSessionState() : null;

  }



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

    return sessionData.isStateless() ? handleEventForStatelessSession(event) : handleEventForStatefulSession(event);

  }



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

    try {

      ClientAuthSessionState state = sessionData.getClientAuthSessionState();

      ClientAuthSessionState oldState = state;



      switch (state) {

        case IDLE:

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

            case SEND_AUTH_REQUEST:

              // Current State: IDLE 

              // Event: Client or Device Requests access

              // Action: Send service specific auth req

              // New State: PENDING

              setState(PENDING);

              break;

            default:

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

              break;

          }

          break;

        case PENDING:

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

            case RECEIVE_AUTH_ANSWER:

              try {

                // Current State: PENDING

                // Event: Successful service-specific authorization answer received with Auth-Session-State set to NO_STATE_MAINTAINED

                // Action: Grant Access

                // New State: OPEN

                listener.doAuthAnswerEvent(this, null, (AppAnswerEvent) event.getData());

                setState(OPEN);

              }

              catch (Exception e) {

                // Current State: PENDING

                // Event: Failed service-specific authorization answer received

                // Action: Cleanup

                // New State: IDLE

                setState(IDLE);

              }

              break;

            case SEND_SESSION_TERMINATION_REQUEST:

              // Current State: OPEN

              // Event: Service to user is terminated

              // Action: Disconnect User/Device

              // New State: IDLE

              setState(IDLE);

              break;

            default:

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

              break;

          }

          break;

        case OPEN:

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

            case SEND_SESSION_ABORT_ANSWER:

            case SEND_SESSION_TERMINATION_REQUEST:

              // Current State: OPEN

              // Event: Service to user is terminated

              // Action: Disconnect User/Device

              // New State: IDLE

              setState(IDLE);

              break;

            case TIMEOUT_EXPIRES:

              // Current State: OPEN

              // Event: Session-Timeout Expires on Access Device

              // Action: Send STR

              // New State: DISCON

              if (context != null) {

                context.accessTimeoutElapses(this);

                Request str = createSessionTermRequest();

                context.disconnectUserOrDev(this, str);

                session.send(str, this);

              }

              // IDLE is the same as DISCON

              setState(IDLE);

              break;

            default:

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

              break;

          }

          break;

      }



      // post processing

      if (oldState != state) {

        if (DISCONNECTED.equals(state) || IDLE.equals(state)) {

          cancelTsTimer();

        }

        else if (OPEN.equals(state) && context != null && context.getAccessTimeout() > 0) {

          cancelTsTimer();

          startTsTimer();

        }

      }

    }

    catch (Throwable t) {

      throw new InternalException(t);

    }



    return true;

  }



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

    ClientAuthSessionState state = sessionData.getClientAuthSessionState();

    ClientAuthSessionState oldState = state;



    try {

      switch (state) {

        case IDLE: {

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

            case SEND_AUTH_REQUEST:

              // Current State: IDLE 

              // Event: Client or Device Requests access

              // Action: Send service specific auth req

              // New State: PENDING

              setState(PENDING);

              break;

            case RECEIVE_ABORT_SESSION_REQUEST:

              // Current State: IDLE

              // Event: ASR Received for unknown session

              // Action: Send ASA with Result-Code = UNKNOWN_SESSION_ID

              // New State: IDLE

              // FIXME: Should send ASA with UNKNOWN_SESSION_ID instead ?

              listener.doAbortSessionRequestEvent(this, (AbortSessionRequest) event.getData());

              break;

            default:

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

              break;

          }

          break;

        }

        case PENDING: {

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

            case RECEIVE_AUTH_ANSWER:

              try {

                // Current State: PENDING

                // Event: Successful service-specific authorization answer received with default Auth-Session-State value

                // Action: Grant Access

                // New State: OPEN

                listener.doAuthAnswerEvent(this, null, (AppAnswerEvent) event.getData());

                setState(OPEN);

              }

              catch (InternalException e) {

                // Current State: PENDING

                // Event: Successful service-specific authorization answer received but service not provided

                // Action: Send STR

                // New State: DISCON



                // Current State: PENDING

                // Event: Error Processing successful service-specific authorization answer

                // Action: Send STR

                // New State: DISCON

                setState(DISCONNECTED);

              }

              catch (Exception e) {

                // Current State: PENDING

                // Event: Failed service-specific authorization answer received

                // Action: Cleanup

                // New State: IDLE

                setState(IDLE);

              }

              break;

            case SEND_SESSION_TERMINATION_REQUEST:

              // Current State: OPEN

              // Event: Service to user is terminated

              // Action: Disconnect User/Device

              // New State: IDLE

            	setState(DISCONNECTED);

            	break;

            default:

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

              break;

          }

          break;

        }

        case OPEN: {

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

            case SEND_AUTH_REQUEST:

              // Current State: OPEN 

              // Event: User or client device requests access to service

              // Action: Send service specific auth req 

              // New State: OPEN

              break;

            case RECEIVE_AUTH_ANSWER:

              try {

                // Current State: OPEN 

                // Event: Successful service-specific authorization answer received

                // Action: Provide Service

                // New State: OPEN

                listener.doAuthAnswerEvent(this, null, (AppAnswerEvent) event.getData());

              }

              catch (Exception e) {

                // Current State: OPEN 

                // Event: ASR Received, client will comply with request to end the session

                // Action: Send ASA with Result-Code = SUCCESS, Send STR

                // New State: DISCON

                setState(DISCONNECTED);

              }

              break;

            case RECEIVE_FAILED_AUTH_ANSWER:

              // Current State: OPEN 

              // Event: Failed Service-specific authorization answer received

              // Action: Disconnect User/Device

              // New State: IDLE

              if (context != null) {

                Request str = createSessionTermRequest();

                context.disconnectUserOrDev(this, str);

                session.send(str, this);

              }

              setState(IDLE);

              break;

            case RECEIVE_ABORT_SESSION_REQUEST:

              // Current State: OPEN 

              // Event: ASR Received (client to take comply or not)  

              // Action: TBD

              // New State: TBD (comply = DISCON, !comply = OPEN)

              listener.doAbortSessionRequestEvent(this, (AbortSessionRequestImpl) event.getData());

              break;

            case SEND_SESSION_TERMINATION_REQUEST:

              setState(DISCONNECTED);

              break;

            case TIMEOUT_EXPIRES:

              // Current State: OPEN 

              // Event: Session-Timeout Expires on Access Device

              // Action: Send STR

              // New State: DISCON



              // Current State: OPEN 

              // Event: Authorization-Lifetime + Auth-Grace-Period expires on access device

              // Action: Send STR

              // New State: DISCON

              if (context != null) {

                context.accessTimeoutElapses(this);

                Request str = createSessionTermRequest();

                context.disconnectUserOrDev(this, str);

                session.send(str, this);

              }

              setState(DISCONNECTED);

              break;

          }

          break;

        }

        case DISCONNECTED: {

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

            case RECEIVE_ABORT_SESSION_REQUEST:

              // Current State: DISCON

              // Event: ASR Received

              // Action: Send ASA

              // New State: DISCON

              listener.doAbortSessionRequestEvent(this, (AbortSessionRequest) event.getData());

              break;

            case RECEIVE_SESSION_TERINATION_ANSWER:

              // Current State: DISCON

              // Event: STA Received

              // Action: Disconnect User/Device

              // New State: IDLE

              listener.doSessionTerminationAnswerEvent(this, ((SessionTermAnswerImpl) event.getData()));

              setState(IDLE);

              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 && context.getAccessTimeout() > 0) {

          cancelTsTimer();

          startTsTimer();

        }

      }

    }

    catch (Throwable t) {

      throw new InternalException(t);

    }



    return true;

  }



  public void receivedSuccessMessage(Request request, Answer answer) {

    AnswerDelivery ad = new AnswerDelivery();

    ad.session = this;

    ad.request = request;

    ad.answer = answer;

    super.scheduler.execute(ad);

  }



  public void timeoutExpired(Request request) {

    try {

      //FIXME: should this also be async ?

      handleEvent(new Event(Event.Type.RECEIVE_FAILED_AUTH_ANSWER, new AppRequestEventImpl(request)));

    }

    catch (Exception e) {

      logger.debug("Can not handle timeout 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() throws IllegalArgumentException, InternalException {

    try {

      sendAndStateLock.lock();

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

    }

    finally {

      sendAndStateLock.unlock();

    }

  }



  protected void cancelTsTimer() {

    try {

      sendAndStateLock.lock();

      Serializable timerId = sessionData.getTsTimerId();

      if(timerId != null) {

        super.timerFacility.cancel(timerId);

        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);

        if (context != null) {

          try {

            handleEvent(new Event(Event.Type.TIMEOUT_EXPIRES, null));

          }

          catch (Exception e) {

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

          }

        }

      }

      finally {

        sendAndStateLock.unlock();

      }

    }

  }



  protected AbortSessionAnswer createAbortSessionAnswer(Answer answer) {

    return new AbortSessionAnswerImpl(answer);

  }



  protected AbortSessionRequest createAbortSessionRequest(Request request) {

    return new AbortSessionRequestImpl(request);

  }



  protected ReAuthAnswer createReAuthAnswer(Answer answer) {

    return new ReAuthAnswerImpl(answer);

  }



  protected ReAuthRequest createReAuthRequest(Request request) {

    return new ReAuthRequestImpl(request);

  }



  protected SessionTermAnswer createSessionTermAnswer(Answer answer) {

    return new SessionTermAnswerImpl(answer);

  }



  protected SessionTermRequest createSessionTermRequest(Request request) {

    return new SessionTermRequestImpl(request);

  }



  protected Request createSessionTermRequest() {

    return session.createRequest(SESSION_TERMINATION_REQUEST, appId, sessionData.getDestinationRealm(), sessionData.getDestinationHost());

  }



  @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;

    GqClientSessionImpl other = (GqClientSessionImpl) obj;

    if (sessionData == null) {

      if (other.sessionData != null)

        return false;

    }

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

      return false;

    return true;

  }



  private class RequestDelivery implements Runnable {

    GqClientSession session;

    Request request;



    public void run() {

      try {

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

          handleEvent(new Event(Event.Type.RECEIVE_ABORT_SESSION_REQUEST, createAbortSessionRequest(request)));

        }

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

          listener.doReAuthRequestEvent(session, createReAuthRequest(request));

        }

        else {        	

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

        }

      }

      catch (Exception e) {

        logger.debug("Can not process received request", e);

      }

    }

  }



  private class AnswerDelivery implements Runnable {

    GqClientSession session;

    Answer answer;

    Request request;



    public void run() {

      try {

        sendAndStateLock.lock();

        // FIXME: baranowb: this shouldn't be like that?

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

          handleEvent(new Event(Event.Type.RECEIVE_AUTH_ANSWER, factory.createAuthAnswer(answer)));          

        }

        else if (answer.getCommandCode() == SessionTermAnswerImpl.code) {        	

          handleEvent(new Event(Event.Type.RECEIVE_SESSION_TERINATION_ANSWER, createSessionTermAnswer(answer)));

        }

        else {        	

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

        }

      }

      catch (Exception e) {

        logger.debug("Can not process received message", e);

      }

      finally {

        sendAndStateLock.unlock();

      }

    }

  }

}