ServerInviteSession.cxx

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#include "resip/stack/MultipartMixedContents.hxx"
#include "resip/stack/MultipartAlternativeContents.hxx"
#include "resip/dum/Dialog.hxx"
#include "resip/dum/DialogEventStateManager.hxx"
#include "resip/dum/DialogUsageManager.hxx"
#include "resip/dum/DumTimeout.hxx"
#include "resip/dum/InviteSessionHandler.hxx"
#include "resip/dum/ServerInviteSession.hxx"
#include "resip/dum/MasterProfile.hxx"
#include "resip/dum/UsageUseException.hxx"
#include "resip/dum/DumHelper.hxx"
#include "resip/dum/DumCommand.hxx"
#include "rutil/Random.hxx"
#include "rutil/Logger.hxx"
#include "rutil/compat.hxx"
#include "rutil/WinLeakCheck.hxx"
 
#include <utility>
 
using namespace resip;
 
#define RESIPROCATE_SUBSYSTEM Subsystem::DUM
 
ServerInviteSession::ServerInviteSession(DialogUsageManager& dum, Dialog& dialog, const SipMessage& request)
   : InviteSession(dum, dialog),
     mFirstRequest(request),
     m1xx(new SipMessage),
     mCurrentRetransmit1xxSeq(0),
     mLocalRSeq(0),
     mAnswerSentReliably(false)
{
   resip_assert(request.isRequest());
   mState = UAS_Start;
}
 
ServerInviteSessionHandle 
ServerInviteSession::getHandle()
{
   return ServerInviteSessionHandle(mDum, getBaseHandle().getId());
}
 
void 
ServerInviteSession::redirect(const NameAddrs& contacts, int code)
{
   InfoLog (<< toData(mState) << ": redirect(" << code << ")"); // -> " << contacts);
 
   switch (mState)
   {
      case UAS_EarlyNoOffer:
      case UAS_EarlyOffer:
      case UAS_EarlyProvidedAnswer:
      case UAS_EarlyProvidedOffer:
      case UAS_NegotiatedReliable:
      case UAS_FirstSentAnswerReliable:
      case UAS_FirstSentOfferReliable:
      case UAS_NoOffer:
      case UAS_NoOfferReliable:
      case UAS_ProvidedOfferReliable:
      case UAS_OfferReliableProvidedAnswer:
      case UAS_NoAnswerReliableWaitingPrack:
      case UAS_NoAnswerReliable:
      case UAS_Offer:
      case UAS_OfferProvidedAnswer:
      case UAS_OfferReliable: 
      case UAS_ProvidedOffer:
      case UAS_ReceivedUpdate:
      case UAS_SentUpdate:
      {
         // !jf! the cleanup for 3xx may be a bit strange if we are in the middle of
         // an offer/answer exchange with PRACK. 
         // e.g. we sent 183 reliably and then 302 before PRACK was received. Ideally,
         // we should send 200PRACK
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, mFirstRequest, code);
         response->header(h_Contacts) = contacts;
         send(response);
 
         if (mDum.mDialogEventStateManager)
         {
            mDum.mDialogEventStateManager->onTerminated(mDialog, *response, InviteSessionHandler::Rejected);
         }
 
         transition(Terminated);
 
         mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::Referred); 
         mDum.destroy(this);
         break;
      }
 
      case UAS_Accepted:
      case UAS_WaitingToOffer:
      case UAS_WaitingToRequestOffer:
      case UAS_WaitingToHangup:
      case UAS_SentUpdateAccepted:
      case UAS_ReceivedUpdateWaitingAnswer:
      case UAS_Start:
      default:
         resip_assert(0);
         throw UsageUseException("Can't redirect after accepted", __FILE__, __LINE__);
         break;
   }
}
 
class ServerInviteSessionRedirectCommand : public DumCommandAdapter
{
public:
   ServerInviteSessionRedirectCommand(const ServerInviteSessionHandle& serverInviteSessionHandle, const NameAddrs& contacts, int code)
      : mServerInviteSessionHandle(serverInviteSessionHandle),
      mContacts(contacts),
      mCode(code)
   {
 
   }
 
   void executeCommand() override
   {
      if(mServerInviteSessionHandle.isValid())
      {
         mServerInviteSessionHandle->redirect(mContacts, mCode);
      }
   }
 
   EncodeStream& encodeBrief(EncodeStream& strm) const override
   {
      return strm << "ServerInviteSessionRedirectCommand";
   }
private:
   ServerInviteSessionHandle mServerInviteSessionHandle;
   NameAddrs mContacts;
   int mCode;
};
 
void 
ServerInviteSession::redirectCommand(const NameAddrs& contacts, int code)
{
   mDum.post(new ServerInviteSessionRedirectCommand(getHandle(), contacts, code));
}
 
void 
ServerInviteSession::provisional(int code, bool earlyFlag)
{
   InfoLog (<< toData(mState) << ": provisional(" << code << ")");
 
   switch (mState)
   {
      case UAS_Offer:
         transition(UAS_EarlyOffer);
         sendProvisional(code, earlyFlag);
         break;
 
      case UAS_OfferProvidedAnswer:
      case UAS_EarlyProvidedAnswer:
         transition(UAS_EarlyProvidedAnswer);
         sendProvisional(code, earlyFlag);
         break;
 
      case UAS_ProvidedOffer:
      case UAS_EarlyProvidedOffer:
         transition(UAS_EarlyProvidedOffer);
         sendProvisional(code, earlyFlag);
         break;
         
      case UAS_EarlyOffer:
         transition(UAS_EarlyOffer);
         sendProvisional(code, earlyFlag);
         break;
         
      case UAS_NoOffer:
      case UAS_EarlyNoOffer:
         transition(UAS_EarlyNoOffer);
         sendProvisional(code, earlyFlag);
         break;
         
      case UAS_NoOfferReliable:
      case UAS_NegotiatedReliable:
      case UAS_FirstSentAnswerReliable:
      case UAS_NoAnswerReliableWaitingPrack: 
      case UAS_FirstSentOfferReliable:
         if(mUnacknowledgedReliableProvisional.get())
         {
            InfoLog (<< "Waiting for PRACK. queued provisional, code=" << code << ", early=" << (earlyFlag ? "YES" : "NO") );
            queueResponse(code, earlyFlag);
         }
         else
         {
            sendProvisional(code, earlyFlag);
         }
         break;
         
      case UAS_NoAnswerReliable:
      case UAS_OfferReliable: 
         if(sendProvisional(code, earlyFlag))
         {
            // If sent reliably then change state
            transition(UAS_NoAnswerReliableWaitingPrack);
         }
         break;
 
      case UAS_ProvidedOfferReliable:
         if(sendProvisional(code, earlyFlag))
         {
            // If sent reliably then change state
            transition(UAS_FirstSentOfferReliable);
         }
         break;
 
      case UAS_OfferReliableProvidedAnswer: 
         if(mUnacknowledgedReliableProvisional.get())  // First 18x may not have contained answer and still be outstanding
         {
            InfoLog (<< "Waiting for PRACK. queued provisional, code=" << code << ", early=" << (earlyFlag ? "YES" : "NO") );
            queueResponse(code, earlyFlag);
         }
         else if(sendProvisional(code, earlyFlag) && earlyFlag)
         {
            // If sent reliably and earlyFlag set (answer actually sent) then change state
            transition(UAS_FirstSentAnswerReliable);
         }
         break;
         
      case UAS_Accepted:
      case UAS_WaitingToOffer:
      case UAS_WaitingToRequestOffer:
      case UAS_ReceivedUpdate:
      case UAS_ReceivedUpdateWaitingAnswer:
      case UAS_SentUpdate:
      case UAS_SentUpdateAccepted:
      case UAS_Start:
      case UAS_WaitingToHangup:
      default:
         resip_assert(0);
         break;
   }
}
 
class ServerInviteSessionProvisionalCommand : public DumCommandAdapter
{
public:
   ServerInviteSessionProvisionalCommand(const ServerInviteSessionHandle& serverInviteSessionHandle, int statusCode, bool earlyFlag)
      : mServerInviteSessionHandle(serverInviteSessionHandle),
        mStatusCode(statusCode),
        mEarlyFlag(earlyFlag)
   {
   }
 
   void executeCommand() override
   {
      if(mServerInviteSessionHandle.isValid())
      {
         mServerInviteSessionHandle->provisional(mStatusCode, mEarlyFlag);
      }
   }
 
   EncodeStream& encodeBrief(EncodeStream& strm) const override
   {
      return strm << "ServerInviteSessionProvisionalCommand";
   }
private:
   ServerInviteSessionHandle mServerInviteSessionHandle;
   int mStatusCode;
   bool mEarlyFlag;
};
 
void 
ServerInviteSession::provisionalCommand(int statusCode, bool earlyFlag)
{
   mDum.post(new ServerInviteSessionProvisionalCommand(getHandle(), statusCode, earlyFlag));
}
 
void
ServerInviteSession::provideOffer(const Contents& offer,
                                  DialogUsageManager::EncryptionLevel level, 
                                  const Contents* alternative,
                                  bool sendOfferAtAccept)
{
   InfoLog (<< toData(mState) << ": provideOffer");
   switch (mState)
   {
      case UAS_NoOffer:
         transition(UAS_ProvidedOffer);
         mProposedLocalOfferAnswer = InviteSession::makeOfferAnswer(offer, alternative);
         mProposedEncryptionLevel = level;
         break;
 
      case UAS_EarlyNoOffer:
         transition(UAS_EarlyProvidedOffer);
         mProposedLocalOfferAnswer = InviteSession::makeOfferAnswer(offer, alternative);
         mProposedEncryptionLevel = level;
         break;
         
      case UAS_NoOfferReliable:
         transition(UAS_ProvidedOfferReliable);
         mProposedLocalOfferAnswer = InviteSession::makeOfferAnswer(offer, alternative);
         mProposedEncryptionLevel = level;
         break;
 
      case UAS_NegotiatedReliable:
         mProposedLocalOfferAnswer = InviteSession::makeOfferAnswer(offer, alternative);
         mProposedEncryptionLevel = level;
         if (sendOfferAtAccept)
         {
            transition(UAS_ProvidedOffer);
         }
         else
         {
            transition(UAS_SentUpdate);
            sendUpdate(offer);
         }
         break;
         
      case UAS_Accepted:
         // queue the offer to be sent after the ACK is received
         transition(UAS_WaitingToOffer);
         mProposedLocalOfferAnswer = InviteSession::makeOfferAnswer(offer);
         mProposedEncryptionLevel = level;
         break;
 
      case UAS_WaitingToOffer:
         InviteSession::provideOffer(offer, level, alternative);
         break;
 
      case UAS_FirstSentAnswerReliable:
          // Queue up offer to be sent after PRACK arrives
         mProposedLocalOfferAnswer = InviteSession::makeOfferAnswer(offer);
         mProposedEncryptionLevel = level;
         break;
 
      case UAS_EarlyProvidedAnswer:
      case UAS_EarlyProvidedOffer:
      case UAS_FirstSentOfferReliable:
      case UAS_Offer:
      case UAS_EarlyOffer:
      case UAS_OfferReliable: 
      case UAS_OfferProvidedAnswer:
      case UAS_ProvidedOffer:
      case UAS_ProvidedOfferReliable:
      case UAS_ReceivedUpdate:
      case UAS_ReceivedUpdateWaitingAnswer:
      case UAS_SentUpdate:
      case UAS_SentUpdateAccepted:
      case UAS_Start:
      case UAS_WaitingToHangup:
      case UAS_WaitingToRequestOffer:
      case UAS_AcceptedWaitingAnswer:
         WarningLog (<< "Incorrect state to provideOffer: " << toData(mState));
         throw DialogUsage::Exception("Can't provide an offer", __FILE__,__LINE__);
         break;
      default:
         InviteSession::provideOffer(offer, level, alternative);
         break;
   }
}
 
void
ServerInviteSession::provideOffer(const Contents& offer,
                                  DialogUsageManager::EncryptionLevel level, 
                                  const Contents* alternative)
{
   this->provideOffer(offer, level, alternative, false);
}
 
void 
ServerInviteSession::provideOffer(const Contents& offer,
                                  bool sendOfferAtAccept)
{
   this->provideOffer(offer, mCurrentEncryptionLevel, 0, sendOfferAtAccept);
}
 
void 
ServerInviteSession::provideOffer(const Contents& offer)
{
   this->provideOffer(offer, mCurrentEncryptionLevel, 0, false);
}
 
void
ServerInviteSession::requestOffer()
{
   InfoLog (<< toData(mState) << ": requestOffer");
   switch (mState)
   {
      case UAS_Accepted:
         // queue the request to be sent after the ACK is received
         transition(UAS_WaitingToRequestOffer);
         break;
 
      case UAS_WaitingToRequestOffer:
         InviteSession::requestOffer();
         break;
 
      default:
         InviteSession::requestOffer();
         break;
   }
}
 
void 
ServerInviteSession::provideAnswer(const Contents& answer)
{
   InfoLog (<< toData(mState) << ": provideAnswer");
   mAnswerSentReliably = false;
   switch (mState)
   {
      case UAS_Offer:
         transition(UAS_OfferProvidedAnswer);
         mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
         mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
         break;
 
      case UAS_EarlyOffer:
         transition(UAS_EarlyProvidedAnswer);
         mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
         mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
         break;
         
      case UAS_OfferReliable: 
         mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
         mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
         transition(UAS_OfferReliableProvidedAnswer);
         break;
 
      case UAS_NoAnswerReliableWaitingPrack: 
         // Store answer and wait for PRACK
         mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
         mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
         break;
 
      case UAS_ReceivedUpdate:
         {
            transition(UAS_NegotiatedReliable);
 
            // Send answer in 200/Update
            auto response = std::make_shared<SipMessage>();
            mDialog.makeResponse(*response, *mLastRemoteSessionModification, 200);
            InviteSession::setOfferAnswer(*response, answer, 0);
            mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
            mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
            InfoLog (<< "Sending " << response->brief());
            DumHelper::setOutgoingEncryptionLevel(*response, mCurrentEncryptionLevel);
            send(response);
         }
         break;
         
      case UAS_ReceivedUpdateWaitingAnswer:
         {
            auto response = std::make_shared<SipMessage>();
            mDialog.makeResponse(*response, *mLastRemoteSessionModification, 200);
            InviteSession::setOfferAnswer(*response, answer, 0);
            mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
            mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
            InfoLog (<< "Sending " << response->brief());
            DumHelper::setOutgoingEncryptionLevel(*response, mCurrentEncryptionLevel);
            send(response);
 
            // send the queued 200/Invite
            updateCheckQueue();
         }
         break;
 
      case UAS_NoAnswerReliable:
         mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
         mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
         transition(UAS_OfferReliableProvidedAnswer);
         break;
 
      // If we received an offer in a PRACK then we transition to NegotiateReliable and expect
      // provideAnswer to be called to send the 200/Prack containing the answer.
      case UAS_NegotiatedReliable:
         if (mPrackWithOffer)
         {
            mCurrentRemoteOfferAnswer = std::move(mProposedRemoteOfferAnswer);
            mCurrentLocalOfferAnswer = InviteSession::makeOfferAnswer(answer);
            auto p200 = std::make_shared<SipMessage>();
            mDialog.makeResponse(*p200, *mPrackWithOffer, 200);
            setOfferAnswer(*p200, mCurrentLocalOfferAnswer.get());
            mAnswerSentReliably = true;
            mPrackWithOffer.reset();
            send(p200);
         }
         else
         {
             resip_assert(0);
         }
         break;
 
      case UAS_Accepted:
      case UAS_WaitingToOffer:
      case UAS_WaitingToRequestOffer:
      case UAS_EarlyNoOffer:
      case UAS_EarlyProvidedAnswer:
      case UAS_EarlyProvidedOffer:
      case UAS_FirstSentAnswerReliable:
      case UAS_FirstSentOfferReliable:
      case UAS_NoOffer:
      case UAS_NoOfferReliable:
      case UAS_OfferProvidedAnswer:
      case UAS_ProvidedOffer:
      case UAS_ProvidedOfferReliable:
      case UAS_SentUpdate:
      case UAS_SentUpdateAccepted:
      case UAS_Start:
      case UAS_WaitingToHangup:
      case UAS_AcceptedWaitingAnswer:
         WarningLog (<< "Incorrect state to provideAnswer: " << toData(mState));
         throw DialogUsage::Exception("Can't provide an answer", __FILE__,__LINE__);
         break;
      default:
         InviteSession::provideAnswer(answer);
         break;
   }
}
 
void
ServerInviteSession::end()
{
   end(NotSpecified);
}
 
void
ServerInviteSession::end(const Data& userReason)
{
   mUserEndReason = userReason;
   end(InviteSession::UserSpecified);
}
 
void
ServerInviteSession::end(const ParserContainer<Token>& endReasons)
{
   mUserEndReasons = endReasons;
   end(InviteSession::UserSpecified);
}
 
void 
ServerInviteSession::end(EndReason reason)
{
   InfoLog (<< toData(mState) << ": end");
   if (mEndReason == NotSpecified)
   {
      mEndReason = reason;   
   }
   
   switch (mState)
   {
      case UAS_EarlyNoOffer:
      case UAS_EarlyOffer:
      case UAS_EarlyProvidedAnswer:
      case UAS_EarlyProvidedOffer:
      case UAS_NoOffer:
      case UAS_Offer:
      case UAS_OfferProvidedAnswer:
      case UAS_ProvidedOffer:
      case UAS_ProvidedOfferReliable:
         reject(480);
         break;         
         
      case UAS_OfferReliable: 
      case UAS_OfferReliableProvidedAnswer:
      case UAS_NegotiatedReliable:
      case UAS_FirstSentOfferReliable:
      case UAS_FirstSentAnswerReliable:
      case UAS_NoAnswerReliableWaitingPrack:
      case UAS_NoAnswerReliable:
      case UAS_NoOfferReliable:
      case UAS_ReceivedUpdate:   // !slg! todo: send 488U
      case UAS_ReceivedUpdateWaitingAnswer: // !slg! todo: send 488U
      case UAS_SentUpdate:
      case UAS_SentUpdateGlare:
      case UAS_SentUpdateAccepted:
         reject(480);
         break;
         
      case UAS_Start:
         resip_assert(0);
         break;
 
      case UAS_Accepted:
      case UAS_WaitingToOffer:
      case UAS_WaitingToRequestOffer:
      case UAS_AcceptedWaitingAnswer:
         if(mCurrentRetransmit200)  // If retransmit200 timer is active then ACK is not received yet - wait for it
         {
            transition(UAS_WaitingToHangup);
         }
         else
         {
             // ACK has likely timed out - hangup immediately
             const auto msg = sendBye();
             transition(Terminated);
             mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::LocalBye, msg.get());
         }
         break;
 
      case UAS_WaitingToHangup:     // This can happen if we are waiting for an ACK to hangup and the ACK timesout
          break;
         
      default:
         InviteSession::end(reason);
         break;
   }
}
 
void 
ServerInviteSession::reject(int code, WarningCategory *warning)
{
   reject(code, nullptr, warning);
}
 
void 
ServerInviteSession::reject(int code, const Contents* contents, WarningCategory *warning)
{
   InfoLog (<< toData(mState) << ": reject(" << code << ")");
 
   switch (mState)
   {
      case UAS_EarlyNoOffer:
      case UAS_EarlyOffer:
      case UAS_EarlyProvidedAnswer:
      case UAS_EarlyProvidedOffer:
      case UAS_NoOffer:
      case UAS_Offer:
      case UAS_OfferProvidedAnswer:
      case UAS_ProvidedOffer:
      case UAS_ProvidedOfferReliable:
 
      case UAS_AcceptedWaitingAnswer:
      case UAS_NegotiatedReliable:
      case UAS_FirstSentAnswerReliable:
      case UAS_NoAnswerReliableWaitingPrack:
      case UAS_NoAnswerReliable:
      case UAS_FirstSentOfferReliable:
      case UAS_NoOfferReliable:
      case UAS_OfferReliable: 
      case UAS_OfferReliableProvidedAnswer:
      case UAS_ReceivedUpdate:   // Note:  This rejects the entire InviteSession - there is no way right now to reject only the Offer that was received via an Update
      case UAS_ReceivedUpdateWaitingAnswer:  // yes it's wrong to call reject after accept - however we can get here from end() as well.  We haven't sent our 200/Inv on the wire yet, so we can just reject the Invite session to end it
      case UAS_SentUpdate:
      case UAS_SentUpdateGlare:
      case UAS_SentUpdateAccepted:  // yes it's wrong to call reject after accept - however we can get here from end() as well.  We haven't sent our 200/Inv on the wire yet, so we can just reject the Invite session to end it
      {
         // !jf! the cleanup for 3xx may be a bit strange if we are in the middle of
         // an offer/answer exchange with PRACK. 
         // e.g. we sent 183 reliably and then 302 before PRACK was received. Ideally,
         // we should send 200PRACK
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, mFirstRequest, code);
         // In case we wanted to reject the request by including content
         if (contents)
         {
            response->setContents(contents);
         }
         if(warning)
         {
            response->header(h_Warnings).push_back(*warning);
         }
         send(response);
 
         if (mDum.mDialogEventStateManager)
         {
            mDum.mDialogEventStateManager->onTerminated(mDialog, *response, InviteSessionHandler::Rejected);
         }
 
         transition(Terminated);
         mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::Rejected); 
         mDum.destroy(this);
         break;
      }
 
      case UAS_Accepted:
      case UAS_WaitingToOffer:
      case UAS_WaitingToRequestOffer:
      case UAS_Start:
      case UAS_WaitingToHangup:
         resip_assert(0);
         break;
 
      default:
         InviteSession::reject(code, contents, warning);
         break;
   }
}
 
void 
ServerInviteSession::accept(int code)
{
   InfoLog (<< toData(mState) << ": accept(" << code << ")");
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   switch (mState)
   {
      case UAS_Offer:
      case UAS_EarlyOffer:
      case UAS_FirstSentOfferReliable:
         resip_assert(0);
         break;
 
      case UAS_OfferProvidedAnswer:
      case UAS_EarlyProvidedAnswer:
         transition(UAS_Accepted);
         sendAccept(code, mCurrentLocalOfferAnswer.get());
         handler->onConnected(getSessionHandle(), *mInvite200);
         break;
         
      case UAS_NoOffer:
      case UAS_EarlyNoOffer:
         resip_assert(0);
         break;
 
      case UAS_ProvidedOffer:
      case UAS_ProvidedOfferReliable:
      case UAS_EarlyProvidedOffer:
         transition(UAS_AcceptedWaitingAnswer);
         sendAccept(code, mProposedLocalOfferAnswer.get());
         break;
         
      case UAS_Accepted:
      case UAS_WaitingToOffer:
      case UAS_WaitingToRequestOffer:
         resip_assert(0);  // Already Accepted
         break;
         
      case UAS_FirstSentAnswerReliable:
      case UAS_NoAnswerReliableWaitingPrack:
         // queue 2xx
         // waiting for PRACK
         InfoLog (<< "Waiting for PRACK. queued 200 OK" );
         queueResponse(code, false);
         break;
         
      case UAS_NegotiatedReliable:
         if (mUnacknowledgedReliableProvisional)
         {
            InfoLog (<< "Waiting for PRACK. queued provisional" );
            queueResponse(code, false);
         }
         else
         {
            transition(UAS_Accepted);
            sendAccept(code, 0);
            handler->onConnected(getSessionHandle(), *mInvite200);
         }
         break;
 
      case UAS_OfferReliableProvidedAnswer: 
         transition(UAS_Accepted);
         sendAccept(code, mCurrentLocalOfferAnswer.get());
         handler->onConnected(getSessionHandle(), *mInvite200);
         break;
 
      case UAS_SentUpdate:
         transition(UAS_SentUpdateAccepted);
         queueResponse(code, false);
         break;
 
      case UAS_ReceivedUpdate:
         transition(UAS_ReceivedUpdateWaitingAnswer);
         queueResponse(code, false);
         break;
         
      case UAS_NoAnswerReliable:
      case UAS_NoOfferReliable:
      case UAS_OfferReliable: 
      case UAS_ReceivedUpdateWaitingAnswer:
      case UAS_SentUpdateAccepted:
      case UAS_Start:
      case UAS_WaitingToHangup:
      default:
         resip_assert(0);
         break;
   }
}
 
class ServerInviteSessionAcceptCommand : public DumCommandAdapter
{
public:
   ServerInviteSessionAcceptCommand(const ServerInviteSessionHandle& serverInviteSessionHandle, int statusCode)
      : mServerInviteSessionHandle(serverInviteSessionHandle),
        mStatusCode(statusCode)
   {
   }
 
   void executeCommand() override
   {
      if(mServerInviteSessionHandle.isValid())
      {
         mServerInviteSessionHandle->accept(mStatusCode);
      }
   }
 
   EncodeStream& encodeBrief(EncodeStream& strm) const override
   {
      return strm << "ServerInviteSessionAcceptCommand";
   }
private:
   ServerInviteSessionHandle mServerInviteSessionHandle;
   int mStatusCode;
};
 
void 
ServerInviteSession::acceptCommand(int statusCode)
{
   mDum.post(new ServerInviteSessionAcceptCommand(getHandle(), statusCode));
}
 
void 
ServerInviteSession::dispatch(const SipMessage& msg)
{
   if (msg.isRequest())
   {
      if (msg.header(h_RequestLine).method() == INFO)
      {
         InviteSession::dispatchInfo(msg);
         return;
      }
      if (msg.header(h_RequestLine).method() == MESSAGE)
      {
         InviteSession::dispatchMessage(msg);
         return;
      }
   }
 
   switch (mState)
   {
      case UAS_Start:
         dispatchStart(msg);
         break;
 
      case UAS_Offer:
      case UAS_EarlyOffer:
      case UAS_EarlyProvidedAnswer:
      case UAS_NoOffer:
      case UAS_ProvidedOffer:
      case UAS_ProvidedOfferReliable:
      case UAS_EarlyNoOffer:
      case UAS_EarlyProvidedOffer:
      case UAS_OfferProvidedAnswer:
      case UAS_NoOfferReliable:
      case UAS_OfferReliable:
      case UAS_NoAnswerReliable:
         dispatchOfferOrEarly(msg);
         break;
      case UAS_OfferReliableProvidedAnswer: 
         dispatchOfferReliableProvidedAnswer(msg);
         break;
      case UAS_Accepted:
         dispatchAccepted(msg);
         break;
      case UAS_WaitingToOffer:
         dispatchWaitingToOffer(msg);
         break;
      case UAS_WaitingToRequestOffer:
         dispatchWaitingToRequestOffer(msg);
         break;
      case UAS_AcceptedWaitingAnswer:
         dispatchAcceptedWaitingAnswer(msg);
         break;         
      case UAS_FirstSentAnswerReliable:
         dispatchFirstSentAnswerReliable(msg);
         break;
      case UAS_NoAnswerReliableWaitingPrack:
         dispatchNoAnswerReliableWaitingPrack(msg);
         break;
      case UAS_FirstSentOfferReliable:
         dispatchFirstSentOfferReliable(msg);
         break;
      case UAS_ReceivedUpdate:
         dispatchReceivedUpdate(msg);
         break;
      case UAS_ReceivedUpdateWaitingAnswer:
         dispatchReceivedUpdateWaitingAnswer(msg);
         break;
      case UAS_SentUpdate:
         dispatchSentUpdate(msg);
         break;
      case UAS_SentUpdateGlare:
         dispatchSentUpdateGlare(msg);
         break;
      case UAS_WaitingToHangup:
         dispatchWaitingToHangup(msg);
         break;
      case UAS_SentUpdateAccepted:
         dispatchSentUpdateAccepted(msg);
         break;
      case UAS_NegotiatedReliable:
         dispatchNegotiatedReliable(msg);
         break;
      default:
         InviteSession::dispatch(msg);
         break;
   }
}
 
void 
ServerInviteSession::dispatch(const DumTimeout& timeout)
{
   if (timeout.type() == DumTimeout::Retransmit1xx)
   {
      if (timeout.seq() == mCurrentRetransmit1xxSeq)  // If timer isn't stopped and this timer is for last 1xx sent, then resend
      {
         send(m1xx);
         startRetransmit1xxTimer();
      }
   }
   else if (timeout.type() == DumTimeout::Resubmit1xxRel)
   {
      if (timeout.seq() == mCurrentRetransmit1xxSeq)  // If timer isn't stopped and this timer is for last 1xx sent, then resend
      {
         // This is not a retransmission, it is a resubmission - ensure the RSeq number is incremented
         if(m1xx->exists(h_RSeq))
         {
            // increment RSeq
            m1xx->header(h_RSeq).value()++;
 
            // Remove any body/sdp
            m1xx->setContents(0);
 
            mUnacknowledgedReliableProvisional = m1xx;
            send(m1xx);
            startResubmit1xxRelTimer();
         }
      }
   }
   else if (timeout.type() == DumTimeout::Retransmit1xxRel)
   {
      if (mUnacknowledgedReliableProvisional.get() &&  
          mUnacknowledgedReliableProvisional->header(h_RSeq).value() == timeout.seq())
      {
         unsigned int duration = 2*timeout.secondarySeq();
         if(duration>=64*Timer::T1)
         {
            InfoLog (<< "Reliable provisional timeout, duration=" << duration );
            auto i504 = std::make_shared<SipMessage>();
            mDialog.makeResponse(*i504, mFirstRequest, 504);
            send(i504);
 
            transition(Terminated);
 
            if (mDum.mDialogEventStateManager)
            {
               SipMessage msg;  // should onTerminated require this msg?
               mDum.mDialogEventStateManager->onTerminated(mDialog, msg, InviteSessionHandler::Timeout);
            }
 
            mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::Timeout);
            mDum.destroy(this);
            return;
         }
         else
         {
            InfoLog (<< "Reliable provisional retransmit, duration=" << duration );
            send(mUnacknowledgedReliableProvisional);
            mDum.addTimerMs(DumTimeout::Retransmit1xxRel, duration, getBaseHandle(), timeout.seq(), duration);
         }
      }
   }
   else if (timeout.type() == DumTimeout::Glare)
   {
      if (mState == UAS_SentUpdateGlare)
      {
         transition(UAS_SentUpdate);
         InfoLog (<< "Retransmitting the UPDATE (glare condition timer)");
         mDialog.makeRequest(*mLastLocalSessionModification, UPDATE);  // increments CSeq
         send(mLastLocalSessionModification);
      }
      else
      {
         InviteSession::dispatch(timeout);
      }
   }
   else
   {
      InviteSession::dispatch(timeout);
   }
}
 
void
ServerInviteSession::dispatchStart(const SipMessage& msg)
{
   resip_assert(msg.isRequest());
   resip_assert(msg.header(h_CSeq).method() == INVITE);
 
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
   storePeerCapabilities(msg);
 
   if (mDum.mDialogEventStateManager)
   {
      mDum.mDialogEventStateManager->onTryingUas(mDialog, msg);
   }
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnInviteOffer:
         *mLastRemoteSessionModification = msg;
         transition(UAS_Offer);
         mProposedRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
         mCurrentEncryptionLevel = getEncryptionLevel(msg);
         handler->onNewSession(getHandle(), InviteSession::Offer, msg);
         if(!isTerminated())  
         {
            handler->onOffer(getSessionHandle(), msg, *offerAnswer);
         }
         break;
      case OnInvite:
         *mLastRemoteSessionModification = msg;
         transition(UAS_NoOffer);
         handler->onNewSession(getHandle(), InviteSession::None, msg);
         if(!isTerminated())  
         {
            handler->onOfferRequired(getSessionHandle(), msg);
         }
         break;
      case OnInviteReliableOffer:
         *mLastRemoteSessionModification = msg;
         transition(UAS_OfferReliable);
         mProposedRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
         mCurrentEncryptionLevel = getEncryptionLevel(msg);
         handler->onNewSession(getHandle(), InviteSession::Offer, msg);
         if(!isTerminated())  
         {
            handler->onOffer(getSessionHandle(), msg, *offerAnswer);
         }
         break;
      case OnInviteReliable:
         *mLastRemoteSessionModification = msg;
         transition(UAS_NoOfferReliable);
         handler->onNewSession(getHandle(), InviteSession::None, msg);
         if(!isTerminated())  
         {
            handler->onOfferRequired(getSessionHandle(), msg);
         }
         break;
      default:
         resip_assert(0);
         break;
   }
}
 
// UAS_Offer, UAS_EarlyOffer, UAS_EarlyProvidedAnswer, UAS_NoOffer, UAS_ProvidedOffer,
// UAS_ProvidedOfferReliable, UAS_EarlyNoOffer, UAS_EarlyProvidedOffer, UAS_OfferProvidedAnswer,
// UAS_NoOfferReliable, UAS_OfferReliable, UAS_NoAnswerReliable
void
ServerInviteSession::dispatchOfferOrEarly(const SipMessage& msg)
{
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
      case OnBye:
         dispatchBye(msg);
         break;
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchAccepted(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   std::unique_ptr<Contents> offerAnswer = InviteSession::getOfferAnswer(msg);
   InfoLog (<< "dispatchAccepted: " << msg.brief());
   
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnInvite:
      case OnInviteReliable:
      case OnInviteOffer:
      case OnInviteReliableOffer:
      case OnUpdate:
      case OnUpdateOffer:
      {
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, msg, 491);
         send(response);
         break;
      }
 
      case OnAck:
      case OnAckAnswer:  // .bwc. unsolicited body in ACK; it would probably make sense to just ignore.
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         transition(Connected);
         handler->onConnectedConfirmed(getSessionHandle(), msg);  
         break;
      
      case OnCancel:
      {
         // Cancel and 200 crossed
         auto c200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*c200, msg, 200);
         send(c200);
         break;
      }
 
      case OnBye:
      {
         auto b200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*b200, msg, 200);
         send(b200);
 
         transition(Terminated);
         handler->onTerminated(getSessionHandle(), InviteSessionHandler::RemoteBye, &msg);
         mDum.destroy(this);
         break;
      }
        
      case OnPrack:
      {
         // should never get a prack here - we always queue up our 200/Inv response
         InfoLog (<< "spurious PRACK in state=" << toData(mState));
         auto p481 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*p481, msg, 481);
         send(p481);
         break;
      }
      
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchWaitingToOffer(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
   InfoLog (<< "dispatchWaitingToOffer: " << msg.brief());
   
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnInvite:
      case OnInviteReliable:
      case OnInviteOffer:
      case OnInviteReliableOffer:
      case OnUpdate:
      case OnUpdateOffer:
      {
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, msg, 491);
         send(response);
         break;
      }
 
      case OnAck:
         resip_assert(mProposedLocalOfferAnswer.get());
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         provideProposedOffer(); 
         break;
      
      case OnAckAnswer:
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         sendBye();
         transition(Terminated);
         handler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg); 
         break;
      
      case OnCancel:
      {
         // Cancel and 200 crossed
         auto c200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*c200, msg, 200);
         send(c200);
         break;
      }
 
      case OnBye:
      {
         auto b200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*b200, msg, 200);
         send(b200);
 
         transition(Terminated);
         handler->onTerminated(getSessionHandle(), InviteSessionHandler::RemoteBye, &msg);
         mDum.destroy(this);
         break;
      }
              
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchWaitingToRequestOffer(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
   InfoLog (<< "dispatchWaitingToRequestOffer: " << msg.brief());
   
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnInvite:
      case OnInviteReliable:
      case OnInviteOffer:
      case OnInviteReliableOffer:
      case OnUpdate:
      case OnUpdateOffer:
      {
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, msg, 491);
         send(response);
         break;
      }
 
      case OnAck:
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         requestOffer(); 
         break;
 
      case OnAckAnswer:
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         sendBye();
         transition(Terminated);
         handler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg); 
         break;
      
      case OnCancel:
      {
         // Cancel and 200 crossed
         auto c200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*c200, msg, 200);
         send(c200);
         break;
      }
 
      case OnBye:
      {
         auto b200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*b200, msg, 200);
         send(b200);
 
         transition(Terminated);
         handler->onTerminated(getSessionHandle(), InviteSessionHandler::RemoteBye, &msg);
         mDum.destroy(this);
         break;
      }
              
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchAcceptedWaitingAnswer(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnInvite:
      case OnInviteReliable:
      case OnInviteOffer:
      case OnInviteReliableOffer:
      case OnUpdate:
      case OnUpdateOffer:
      {
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, msg, 491);
         send(response);
         break;
      }
 
      case OnAckAnswer:
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         transition(Connected);
         setCurrentLocalOfferAnswer(msg);
         mCurrentEncryptionLevel = getEncryptionLevel(msg);
         mCurrentRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
         handler->onAnswer(getSessionHandle(), msg, *offerAnswer);
         if(!isTerminated())  // onAnswer callback may call end() or reject()
         {
            handler->onConnected(getSessionHandle(), msg);
         }
         break;
 
      case OnAck:
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
         mEndReason = IllegalNegotiation;
         sendBye();
         transition(Terminated);
         handler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg);
         break;
         
      case OnCancel:
      {
         // no transition
         auto c200 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*c200, msg, 200);
         send(c200);
         break;
      }
 
      case OnPrack:
      {
         // should never get a prack here - we always queue up our 200/Inv response
         InfoLog (<< "spurious PRACK in state=" << toData(mState));
         auto p481 = std::make_shared<SipMessage>();
         mDialog.makeResponse(*p481, msg, 481);
         send(p481);
         break;
      }
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchFirstSentOfferReliable(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
 
      case OnPrack:
         if(handlePrack(msg))
         {
            if (offerAnswer)  // Answer
            {
               transition(UAS_NegotiatedReliable);
               auto p200 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p200, msg, 200);
               send(p200);
 
               setCurrentLocalOfferAnswer(msg);
               mCurrentRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
               mCurrentEncryptionLevel = getEncryptionLevel(msg);
               handler->onPrack(getHandle(), msg);
               handler->onAnswer(getSessionHandle(), msg, *offerAnswer);
            }
            else
            {
               mEndReason = IllegalNegotiation;
               transition(Terminated);
               handler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg);
 
               // 406 the Prack
               auto p406 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p406, msg, 406);
               send(p406);
 
               // 406 the Invite
               auto i406 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*i406, mFirstRequest, 406);
               send(i406);
 
               mDum.destroy(this);
            }
         }
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
bool
ServerInviteSession::handlePrack(const SipMessage& msg)
{
   InfoLog (<< "handlePrack");
 
   if(mUnacknowledgedReliableProvisional.get() && 
      mUnacknowledgedReliableProvisional->header(h_RSeq).value() == msg.header(h_RAck).rSequence() &&
      mUnacknowledgedReliableProvisional->header(h_CSeq).sequence() == msg.header(h_RAck).cSequence() &&
      mUnacknowledgedReliableProvisional->header(h_CSeq).method() == msg.header(h_RAck).method())
   {
       mUnacknowledgedReliableProvisional.reset();  // Clear storage we have received our PRACK
 
       InfoLog (<< "Found matching provisional for PRACK.");
       return true;
   }
 
   InfoLog (<< "spurious PRACK in state=" << toData(mState));
   auto p481 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*p481, msg, 481);
   send(p481);
   return false;
}
 
void
ServerInviteSession::prackCheckQueue()
{
   InfoLog (<< "prackCheckQueue: " << mQueuedResponses.size() );
   if (!mQueuedResponses.empty() && mQueuedResponses.front().first < 200)
   {
      InfoLog (<< "Sending queued provisional" );
      sendProvisional(mQueuedResponses.front().first, mQueuedResponses.front().second);
      mQueuedResponses.pop_front();
   }
   else if (!mQueuedResponses.empty() && mQueuedResponses.front().first < 300)
   {
      InfoLog (<< "Sending queued 200 OK" );
      InviteSessionHandler* handler = mDum.mInviteSessionHandler;
      transition(UAS_Accepted);
      Contents* sdp = 0;
      if( !mAnswerSentReliably && mCurrentLocalOfferAnswer.get())
      {
         sdp = mCurrentLocalOfferAnswer.get();
      }
      sendAccept(mQueuedResponses.front().first, sdp);
      handler->onConnected(getSessionHandle(), *mInvite200);
      mQueuedResponses.clear();  // shouldn't be any provisionals or 200's behind us in queue - just clear the entire queue
   }
}
 
void
ServerInviteSession::updateCheckQueue()
{
   // TODO  - should we be skipping over or ignoring any provisionals in the queue?
   InfoLog (<< "updateCheckQueue: " << mQueuedResponses.size() );
   if (!mQueuedResponses.empty() && 
       mQueuedResponses.front().first >= 200 &&
       mQueuedResponses.front().first < 300)
   {
      InfoLog (<< "Sending queued 200 OK" );
      InviteSessionHandler* handler = mDum.mInviteSessionHandler;
      transition(UAS_Accepted);
      sendAccept(mQueuedResponses.front().first, 0);
      handler->onConnected(getSessionHandle(), *mInvite200);
      mQueuedResponses.pop_front();
   }
}
 
void 
ServerInviteSession::dispatchOfferReliableProvidedAnswer(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
         dispatchBye(msg);
         break;
 
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
 
      case OnPrack:
         if(handlePrack(msg))
         {
            if (offerAnswer)
            {
               // 2nd offer, we haven't answered the first one - log error an proceed by igoring body
               ErrLog (<< "PRACK with new offer when in state=" << toData(mState));
 
               mEndReason = IllegalNegotiation;
               transition(Terminated);
               handler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg);
 
               // 406 the Prack
               auto p406 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p406, msg, 406);
               send(p406);
 
               // 406 the Invite
               auto i406 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*i406, mFirstRequest, 406);
               send(i406);
 
               mDum.destroy(this);
            }
            else
            {
               // Send 200/PRACK
               auto p200 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p200, msg, 200);
               send(p200);
 
               // If we have a provisional to send with answer then transition to UAS_FirstSentAnswerReliable
               if (!mQueuedResponses.empty() && 
                   mQueuedResponses.front().first < 200 &&
                   mQueuedResponses.front().second)  // Early flag is on
               {
                  transition(UAS_FirstSentAnswerReliable);
               }
               handler->onPrack(getHandle(), msg);
               prackCheckQueue();
            }
         }
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void 
ServerInviteSession::dispatchFirstSentAnswerReliable(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
         dispatchBye(msg);
         break;
 
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
 
      case OnPrack:
         if(handlePrack(msg))
         {
            if (offerAnswer)  // New offer
            {
               // If we have an offer in the prack and the dum user also tried to provide a new offer, then
               // reject the dum api offer and pass the one from the wire to the application
               if (mProposedLocalOfferAnswer)
               {
                   handler->onOfferRejected(getSessionHandle(), 0); 
               }
               // dispatch offer here and respond with 200OK in provideAnswer
               transition(UAS_NegotiatedReliable);
               mPrackWithOffer = std::make_shared<SipMessage>(msg);
               mProposedRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
               mCurrentEncryptionLevel = getEncryptionLevel(msg);
               handler->onPrack(getHandle(), msg);
               if(!isTerminated())  
               {
                  handler->onOffer(getSessionHandle(), msg, *offerAnswer);
               }
            }
            else
            {
               auto p200 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p200, msg, 200);
               send(p200);
               // check if we have a queued up offer then sent it - if not check prack queue
               if (mProposedLocalOfferAnswer)
               {
                  transition(UAS_SentUpdate);
                  handler->onPrack(getHandle(), msg);
                  sendUpdate(*mProposedLocalOfferAnswer);
               }
               else
               {
                  transition(UAS_NegotiatedReliable);
                  handler->onPrack(getHandle(), msg);
                  prackCheckQueue();
               }
            }
         }
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void 
ServerInviteSession::dispatchNoAnswerReliableWaitingPrack(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
 
      case OnPrack:
         if(handlePrack(msg))
         {
            if (offerAnswer)
            {
               // 2nd offer, we haven't answered the first one - log error an proceed by ignoring body
               ErrLog (<< "PRACK with new offer when in state=" << toData(mState));
 
               mEndReason = IllegalNegotiation;
               transition(Terminated);
               handler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg);
 
               // 406 the Prack
               auto p406 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p406, msg, 406);
               send(p406);
 
               // 406 the Invite
               auto i406 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*i406, mFirstRequest, 406);
               send(i406);
 
               mDum.destroy(this);
            }
            else
            {
               // Send 200/PRACK
               auto p200 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p200, msg, 200);
               send(p200);
 
               transition(UAS_NoAnswerReliable);
               handler->onPrack(getHandle(), msg);
 
               // If we have a provisional to send with answer then transition to UAS_FirstSentAnswerReliable,
               // otherwise if there is no answer, go to UAS_NoAnswerReliableWaitingPrack.
               if (!mQueuedResponses.empty() && mQueuedResponses.front().first < 200)
               {
                  if (mQueuedResponses.front().second)  // Early flag is on
                  {
                     transition(UAS_FirstSentAnswerReliable);
                  }
                  else
                  {
                     transition(UAS_NoAnswerReliableWaitingPrack);
                  }
               }
               prackCheckQueue();
            }
         }
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchSentUpdate(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      case OnUpdateOffer:
      {
         // Glare
         auto response = std::make_shared<SipMessage>();
         mDialog.makeResponse(*response, msg, 491);
         send(response);
         break;
      }
 
      case On200Update:
         transition(UAS_NegotiatedReliable);
         if (offerAnswer)
         {
            setCurrentLocalOfferAnswer(msg);
            mCurrentRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
            mCurrentEncryptionLevel = getEncryptionLevel(msg);
            handler->onAnswer(getSessionHandle(), msg, *offerAnswer);
         }
         prackCheckQueue();  // needed for when provideOffer then accept are both called in FirstSentAnswerReliable
         break;
 
     case OnUpdateRejected:
     case OnGeneralFailure:  // handle 481 or 408 responses
         transition(UAS_NegotiatedReliable);
         mProposedLocalOfferAnswer.reset();
         handler->onOfferRejected(getSessionHandle(), &msg);
         prackCheckQueue();  // needed for when provideOffer then accept are both called in FirstSentAnswerReliable
         break;
 
      case On491Update:
         transition(UAS_SentUpdateGlare);
         start491Timer();
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchSentUpdateGlare(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      case OnUpdateOffer:
         handler->onOfferRejected(getSessionHandle(), &msg);
         // handle as if we received in NegotiatedReliable
         dispatchNegotiatedReliable(msg);
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchSentUpdateAccepted(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
 
      case On200Update:
         transition(UAS_Accepted);
         if (offerAnswer)
         {
            setCurrentLocalOfferAnswer(msg);
            mCurrentRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
            mCurrentEncryptionLevel = getEncryptionLevel(msg);
            handler->onAnswer(getSessionHandle(), msg, *offerAnswer);
         }
         updateCheckQueue();
         break;
 
      case OnUpdateRejected:
      case OnGeneralFailure:   // handle 481 or 408 responses
         transition(UAS_Accepted);
         mProposedLocalOfferAnswer.reset();
         handler->onOfferRejected(getSessionHandle(), &msg);
         updateCheckQueue();
         break;
 
      case On491Update:
         // strange case - we send an offer then called accept and the offer/update got 491'd - treating the same as any offer error
         transition(UAS_Accepted);
         mProposedLocalOfferAnswer.reset();
         handler->onOfferRejected(getSessionHandle(), &msg);
         updateCheckQueue();
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchReceivedUpdate(const SipMessage& msg)
{
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      case OnUpdateOffer:
         // If we receive an UPDATE before we have generated a final response to a previous UPDATE on the 
         // same dialog, then we MUST return a 500 response with a Retry-After header (random duration 0-10 seconds)
         {
            auto u500 = std::make_shared<SipMessage>();
            mDialog.makeResponse(*u500, msg, 500);
            u500->header(h_RetryAfter).value() = Random::getRandom() % 10;
            send(u500);
         }
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchReceivedUpdateWaitingAnswer(const SipMessage& msg)
{
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnUpdate:
      case OnUpdateOffer:
         // A UAS that receives an UPDATE before it has generated a final response to a previous UPDATE on the 
         // same dialog MUST return a 500 response
         {
            auto u500 = std::make_shared<SipMessage>();
            mDialog.makeResponse(*u500, msg, 500);
            send(u500);
         }
         break;
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchNegotiatedReliable(const SipMessage& msg)
{
   InviteSessionHandler* handler = mDum.mInviteSessionHandler;
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnCancel:
         dispatchCancel(msg);
         break;
 
      case OnBye:
          dispatchBye(msg);
          break;
 
      case OnPrack:
         if(handlePrack(msg))
         {
            if (offerAnswer)  // New offer
            {
               // dispatch offer here and respond with 200OK in provideAnswer
               mPrackWithOffer = std::make_shared<SipMessage>(msg);
               mProposedRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
               mCurrentEncryptionLevel = getEncryptionLevel(msg);
               handler->onPrack(getHandle(), msg);
               if(!isTerminated())  
               {
                  handler->onOffer(getSessionHandle(), msg, *offerAnswer);
               }
            }
            else
            {
               auto p200 = std::make_shared<SipMessage>();
               mDialog.makeResponse(*p200, msg, 200);
               send(p200);
               handler->onPrack(getHandle(), msg);
               prackCheckQueue();
            }
         }
         break;
 
      case OnUpdateOffer:
         *mLastRemoteSessionModification = msg;
         transition(UAS_ReceivedUpdate);
         mProposedRemoteOfferAnswer = InviteSession::makeOfferAnswer(*offerAnswer);
         mCurrentEncryptionLevel = getEncryptionLevel(msg);
         if(!isTerminated())  
         {
            handler->onOffer(getSessionHandle(), msg, *offerAnswer);
         }
         break;
         
      case OnUpdate:
      {
          // Update with no SDP is a target refresh ?slg? just respond immediately - do we need a callback?
          // Note: target refresh handling is in Dialog::handleTargetRefresh
          auto response = std::make_shared<SipMessage>();
          mDialog.makeResponse(*response, msg, 200);
          send(response);
          break;
      }
 
      default:
         if(msg.isRequest())
         {
            dispatchUnknown(msg);
         }
         break;
   }
}
 
void
ServerInviteSession::dispatchWaitingToHangup(const SipMessage& msg)
{
   const auto offerAnswer = InviteSession::getOfferAnswer(msg);
 
   switch (toEvent(msg, offerAnswer.get()))
   {
      case OnAck:
      case OnAckAnswer:
      {
         mCurrentRetransmit200 = 0; // stop the 200 retransmit timer
 
         const auto msg = sendBye();
         transition(Terminated);
         mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::LocalBye, msg.get());
         break;
      }
      
      default:
         break;
   }
}
 
void
ServerInviteSession::dispatchCancel(const SipMessage& msg)
{
   auto c200 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*c200, msg, 200);
   send(c200);
 
   auto i487 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*i487, mFirstRequest, 487);
   send(i487);
 
   transition(Terminated);
 
   if (mDum.mDialogEventStateManager)
   {
      mDum.mDialogEventStateManager->onTerminated(mDialog, msg, InviteSessionHandler::RemoteCancel);
   }
 
   mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::RemoteCancel, &msg);
   mDum.destroy(this);
}
 
void
ServerInviteSession::dispatchBye(const SipMessage& msg)
{
   auto b200 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*b200, msg, 200);
   send(b200);
// !dcm! -- pretty sure we shouldn't 487 after the BYE/200
   auto i487 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*i487, mFirstRequest, 487);
   send(i487);
 
   transition(Terminated);
 
   mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::RemoteBye, &msg);
   mDum.destroy(this);
}
 
void
ServerInviteSession::dispatchUnknown(const SipMessage& msg)
{
   InfoLog (<< "Unknown request (" << msg.brief() << ") received in state=" << toData(mState) << ", rejecting request and terminating call.");
 
   auto r500 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*r500, msg, 500);
   send(r500);
   
   auto i400 = std::make_shared<SipMessage>();
   mDialog.makeResponse(*i400, mFirstRequest, 400);
   send(i400);
 
   transition(Terminated);
   mDum.mInviteSessionHandler->onTerminated(getSessionHandle(), InviteSessionHandler::Error, &msg);
   mDum.destroy(this);
}
 
void 
ServerInviteSession::startRetransmit1xxTimer()
{
   // RFC3261 13.3.1 says the UAS must send a non-100 provisional response every minute, to handle the posiblity of lost provisional responses
   int retransmissionTime = mDialog.mDialogSet.getUserProfile()->get1xxRetransmissionTime();
   if(retransmissionTime > 0 && m1xx->header(resip::h_StatusLine).statusCode() > 100)
   {
      mDum.addTimer(DumTimeout::Retransmit1xx, retransmissionTime, getBaseHandle(), ++mCurrentRetransmit1xxSeq);
   }
}
 
void 
ServerInviteSession::startResubmit1xxRelTimer()
{
   // RFC3262 section says the UAS SHOULD send reliable provisional responses once every two and half minutes
   int resubmitTime = mDialog.mDialogSet.getUserProfile()->get1xxRelResubmitTime();
   if(resubmitTime > 0 && m1xx->header(resip::h_StatusLine).statusCode() > 100)
   {
      mDum.addTimer(DumTimeout::Resubmit1xxRel, resubmitTime, getBaseHandle(), ++mCurrentRetransmit1xxSeq);  // This timer serves the same purpose at the unreliable retransmit timer - use the same sequence number
   }
}
 
void
ServerInviteSession::startRetransmit1xxRelTimer()
{
   unsigned int seq = m1xx->header(h_RSeq).value();
   mDum.addTimerMs(DumTimeout::Retransmit1xxRel, Timer::T1, getBaseHandle(), seq, Timer::T1);
}
 
bool
ServerInviteSession::sendProvisional(int code, bool earlyFlag)
{
   m1xx->setContents(0);
   mDialog.makeResponse(*m1xx, mFirstRequest, code);
 
   bool sendReliably = code > 100 &&   // Must be a non-100 response
                       ((mFirstRequest.exists(h_Requires) && mFirstRequest.header(h_Requires).find(Token(Symbols::C100rel))) ||     // Far end requires it (note:  we must at least support it or the invite would have been rejected already)
                         mDum.getMasterProfile()->getUasReliableProvisionalMode() == MasterProfile::Required ||                     // OR we require it (note: far end must at least support it or the invite would have been rejected)
                         (mFirstRequest.exists(h_Supporteds) && mFirstRequest.header(h_Supporteds).find(Token(Symbols::C100rel)) && // OR far ends supports it and we support it 
                          mDum.getMasterProfile()->getUasReliableProvisionalMode() == MasterProfile::Supported));                   // (note:  SupportedEssential is not trapped here, cases for it are added below)
 
   switch (mState)
   {
      case UAS_OfferProvidedAnswer:
      case UAS_EarlyProvidedAnswer:
         if (code > 100 && earlyFlag && mCurrentLocalOfferAnswer.get()) // early media
         {
            setOfferAnswer(*m1xx, mCurrentLocalOfferAnswer.get());
         }
         break;
 
      case UAS_FirstSentAnswerReliable: // This is possible if someone called provisional() from the onPrack callback (since we change states after we call onPrack)
      case UAS_OfferReliableProvidedAnswer:  // MAY send answer in reliable response - send only if earlyFlag is set
         if (code > 100 && earlyFlag && !mAnswerSentReliably && mCurrentLocalOfferAnswer.get()) // early media
         {
            setOfferAnswer(*m1xx, mCurrentLocalOfferAnswer.get());
            mAnswerSentReliably = true;
            sendReliably = true;  // If UasReliableProvisionalMode is SupportEssential this may flip sendReliably to true
         }
         break;
 
      case UAS_NoOfferReliable:
         if(sendReliably)
         {
             // Invite requires reliable responses - since there was no offer in the INVITE we MUST 
             // provide an offer in the first reliable response.  We would be in the ProvidedOfferReliable
             // state if that was the case.  Looks like provisional was called too early!
             DebugLog( << "Sending a reliable provisional after receiving an INVITE with no offer, requires provideOffer to be called first (RFC3262-Section 5).");
             resip_assert(false);
             return false;
         }
         break;
 
      case UAS_ProvidedOfferReliable:
         //  ignore early flag if we must sendReliably, since first reliable 1xx MUST contain Offer
         if (code > 100 && (earlyFlag || sendReliably) && mProposedLocalOfferAnswer.get())  
         {
            setOfferAnswer(*m1xx, mProposedLocalOfferAnswer.get());
            sendReliably = true; // If UasReliableProvisionalMode is SupportEssential this may flip sendReliably to true
         }
         break;
 
      case UAS_ProvidedOffer:
      case UAS_EarlyProvidedOffer:
         if (code > 100 && earlyFlag && mProposedLocalOfferAnswer.get()) 
         {
            setOfferAnswer(*m1xx, mProposedLocalOfferAnswer.get());
         }
         break;
 
      default:
         break;
   }
   DumHelper::setOutgoingEncryptionLevel(*m1xx, mProposedEncryptionLevel);
 
   if(sendReliably)
   {
      DebugLog ( << "Sending provisional reliably" );
      if (!m1xx->exists(h_Requires) ||
          !m1xx->header(h_Requires).find(Token(Symbols::C100rel)))
      {
         m1xx->header(h_Requires).push_back(Token(Symbols::C100rel));
      }
      m1xx->header(h_RSeq).value() = ++mLocalRSeq;
 
      // We are supposed to advertised our Allow header in reliable provisionals - Add Advertised 
      // Capabilities - allows UAC to detect UPDATE support before 200 response
      mDum.setAdvertisedCapabilities(*m1xx, mDialog.mDialogSet.getUserProfile());
 
      resip_assert(!mUnacknowledgedReliableProvisional.get());
      mUnacknowledgedReliableProvisional = m1xx;
      startRetransmit1xxRelTimer();  // handles retransmissions until PRACK arrives
      startResubmit1xxRelTimer(); // handles - RFC3262 section says the UAS SHOULD send provisional reliable responses once every two and half minutes
   }
   else
   {
      // Make sure there is no RSeq or Requires 100rel
      if(m1xx->exists(h_RSeq))
      {
         m1xx->remove(h_RSeq);
      }
      if(m1xx->exists(h_Requires))
      {
         ParserContainer<Token>::iterator it = m1xx->header(h_Requires).begin();
         for(; it != m1xx->header(h_Requires).end(); it++)
         {
            if((*it) == Token(Symbols::C100rel))
            {
               m1xx->header(h_Requires).erase(it);
               break;
            }
         }
      }
      startRetransmit1xxTimer();
   }
 
   if (mDum.mDialogEventStateManager)
   {
      mDum.mDialogEventStateManager->onEarly(mDialog, getSessionHandle());
   }
 
   send(m1xx);
   return sendReliably;
}
 
void
ServerInviteSession::queueResponse(int code, bool earlyFlag)
{
   InfoLog (<< "Response " << code << " queued." );
   mQueuedResponses.emplace_back(std::make_pair(code, earlyFlag));
}
 
void
ServerInviteSession::sendAccept(int code, Contents* offerAnswer)
{
   mDialog.makeResponse(*mInvite200, mFirstRequest, code);
   handleSessionTimerRequest(*mInvite200, mFirstRequest);
   if (offerAnswer && !mAnswerSentReliably )
   {
      setOfferAnswer(*mInvite200, offerAnswer);
      mAnswerSentReliably = true;
   }
   mCurrentRetransmit1xxSeq++; // Stop the 1xx timer - causes timer to be ignored on expiry
   startRetransmit200Timer();  // 2xx timer
   DumHelper::setOutgoingEncryptionLevel(*mInvite200, mCurrentEncryptionLevel);
 
   if (mDum.mDialogEventStateManager)
   {
      mDum.mDialogEventStateManager->onConfirmed(mDialog, getSessionHandle());
   }
 
   send(mInvite200);
}
 
void
ServerInviteSession::sendUpdate(const Contents& offerAnswer)
{
   if (updateMethodSupported())
   {
      mDialog.makeRequest(*mLastLocalSessionModification, UPDATE);
      InviteSession::setOfferAnswer(*mLastLocalSessionModification, offerAnswer);
      DumHelper::setOutgoingEncryptionLevel(*mLastLocalSessionModification, mProposedEncryptionLevel);
      send(mLastLocalSessionModification);
   }
   else
   {
      throw UsageUseException("Can't send UPDATE to peer", __FILE__, __LINE__);
   }
}
 
/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 
 *    distribution.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 *    and "Vovida Open Communication Application Library (VOCAL)" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact vocal@vovida.org.
 *
 * 4. Products derived from this software may not be called "VOCAL", nor
 *    may "VOCAL" appear in their name, without prior written
 *    permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 *
 */