turnsocket.cxx

这是国外的resip协议栈

         {
            // Missing RemoteAddress or ChannelNumber attribute
            WarningLog(<< "DataInd missing attributes.");
            return asio::error_code(reTurn::MissingAttributes, asio::error::misc_category);
         }

         StunTuple remoteTuple;
         remoteTuple.setTransportType(mRelayTuple.getTransportType());
         StunMessage::setTupleFromStunAtrAddress(remoteTuple, stunMessage.mTurnPeerAddress);

         RemotePeer* remotePeer = mChannelManager.findRemotePeerByPeerAddress(remoteTuple);
         if(!remotePeer)
         {
            // Remote Peer not found - discard data
            WarningLog(<< "Data received from unknown RemotePeer - discarding");
            return asio::error_code(reTurn::UnknownRemoteAddress, asio::error::misc_category);
         }

         if(remotePeer->getServerToClientChannel() != 0 && remotePeer->getServerToClientChannel() != stunMessage.mTurnChannelNumber)
         {
            // Mismatched channel number
            WarningLog(<< "Channel number received in DataInd (" << (int)stunMessage.mTurnChannelNumber << ") does not match existing number for RemotePeer (" << (int)remotePeer->getServerToClientChannel() << ").");
            return asio::error_code(reTurn::InvalidChannelNumberReceived, asio::error::misc_category);
         }

         if(!remotePeer->isServerToClientChannelConfirmed())
         {
            remotePeer->setServerToClientChannel(stunMessage.mTurnChannelNumber);
            remotePeer->setServerToClientChannelConfirmed();
            mChannelManager.addRemotePeerServerToClientChannelLookup(remotePeer);
         }

         if(mLocalBinding.getTransportType() == StunTuple::UDP)
         {
            // If UDP, then send TurnChannelConfirmationInd
            StunMessage channelConfirmationInd;
            channelConfirmationInd.createHeader(StunMessage::StunClassIndication, StunMessage::TurnChannelConfirmationMethod);
            channelConfirmationInd.mHasTurnPeerAddress = true;
            channelConfirmationInd.mTurnPeerAddress = stunMessage.mTurnPeerAddress;
            channelConfirmationInd.mHasTurnChannelNumber = true;
            channelConfirmationInd.mTurnChannelNumber = stunMessage.mTurnChannelNumber;

            // send channelConfirmationInd to local client
            unsigned int bufferSize = 8 /* Stun Header */ + 36 /* Remote Address (v6) */ + 8 /* TurnChannelNumber */ + 4 /* Turn Frame size */;
            resip::Data buffer(bufferSize, resip::Data::Preallocate);
            unsigned int writeSize = channelConfirmationInd.stunEncodeFramedMessage((char*)buffer.data(), bufferSize);

            DebugLog(<< "Channel confirmation indication send for channel: " << stunMessage.mTurnChannelNumber);

            errorCode = rawWrite(buffer.data(), writeSize);
         }

         if(stunMessage.mHasTurnData)
         {
            if(stunMessage.mTurnData->size() > size)
            {
               // Passed in buffer is not large enough
               WarningLog(<< "Passed in buffer not large enough.");
               return asio::error_code(reTurn::BufferTooSmall, asio::error::misc_category);
            }

            memcpy(buffer, stunMessage.mTurnData->data(), stunMessage.mTurnData->size());
            size = (unsigned int)stunMessage.mTurnData->size();

            if(sourceAddress != 0)
            {
               *sourceAddress = remoteTuple.getAddress();
            }
            if(sourcePort != 0)
            {
               *sourcePort = remoteTuple.getPort();
            }
         }
         else
         {
            size = 0;
         }
      }
      else if(stunMessage.mClass == StunMessage::StunClassIndication && stunMessage.mMethod == StunMessage::TurnChannelConfirmationMethod)
      {
         if(!stunMessage.mHasTurnPeerAddress || !stunMessage.mHasTurnChannelNumber)
         {
            // Missing RemoteAddress or ChannelNumber attribute
            WarningLog(<< "DataInd missing attributes.");
            return asio::error_code(reTurn::MissingAttributes, asio::error::misc_category);
         }

         StunTuple remoteTuple;
         remoteTuple.setTransportType(mRelayTuple.getTransportType());
         StunMessage::setTupleFromStunAtrAddress(remoteTuple, stunMessage.mTurnPeerAddress);

         RemotePeer* remotePeer = mChannelManager.findRemotePeerByClientToServerChannel(stunMessage.mTurnChannelNumber);
         if(!remotePeer)
         {
            // Remote Peer not found - discard
            WarningLog(<< "Received ChannelConfirmationInd for unknown channel (" << stunMessage.mTurnChannelNumber << ") - discarding");
            return asio::error_code(reTurn::InvalidChannelNumberReceived, asio::error::misc_category);
         }

         if(remotePeer->getPeerTuple() != remoteTuple)
         {
            // Mismatched remote address
            WarningLog(<< "RemoteAddress associated with channel (" << remotePeer->getPeerTuple() << ") does not match ChannelConfirmationInd (" << remoteTuple << ").");
            return asio::error_code(reTurn::UnknownRemoteAddress, asio::error::misc_category);
         }

         remotePeer->setClientToServerChannelConfirmed();
         size = 0;
      }
      else if(stunMessage.mClass == StunMessage::StunClassRequest && stunMessage.mMethod == StunMessage::BindMethod)
      {
         // Note: handling of BindRequest is not fully backwards compatible with RFC3489 - it is inline with bis11
         StunMessage response;

         // form the outgoing message
         response.mClass = StunMessage::StunClassSuccessResponse;
         response.mMethod = StunMessage::BindMethod;

         // Copy over TransactionId
         response.mHeader.magicCookieAndTid = stunMessage.mHeader.magicCookieAndTid;

         // Add XOrMappedAddress to response 
         response.mHasXorMappedAddress = true;
         StunMessage::setStunAtrAddressFromTuple(response.mXorMappedAddress, stunMessage.mRemoteTuple);

         // send bind response to local client
         unsigned int bufferSize = 8 /* Stun Header */ + 36 /* XorMapped Address (v6) */ + 4 /* Turn Frame size */;
         resip::Data buffer(bufferSize, resip::Data::Preallocate);
         unsigned int writeSize = response.stunEncodeFramedMessage((char*)buffer.data(), bufferSize);

         errorCode = rawWrite(buffer.data(), writeSize);
         size = 0; // go back to receiving
      }
      else if(stunMessage.mClass == StunMessage::StunClassIndication && stunMessage.mMethod == StunMessage::BindMethod)
      {
         // Nothing to do
         size = 0;
      }
      else if(stunMessage.mClass == StunMessage::StunClassSuccessResponse || stunMessage.mClass == StunMessage::StunClassErrorResponse)
      {
         // Received a stray or response retranmission - ignore
         size = 0;
      }
      else
      {
         // TODO - handle others ????
      }
   }
   else
   {
      WarningLog(<< "Read Invalid StunMsg.");
      return asio::error_code(reTurn::ErrorParsingMessage, asio::error::misc_category);
   }
   return errorCode;
}

void 
TurnSocket::startReadTimer(unsigned int timeout)
{
   if(timeout != 0)
   {
      mReadTimer.expires_from_now(boost::posix_time::milliseconds(timeout));
      mReadTimer.async_wait(boost::bind(&TurnSocket::handleRawReadTimeout, this, asio::placeholders::error));
   }
}

void 
TurnSocket::handleRawRead(const asio::error_code& errorCode, size_t bytesRead)
{
   mBytesRead = bytesRead;
   mReadErrorCode = errorCode;
   mReadTimer.cancel();
}

void 
TurnSocket::handleRawReadTimeout(const asio::error_code& errorCode)
{
   if(!errorCode)
   {
      cancelSocket();
   }
}

asio::error_code 
TurnSocket::checkIfAllocationRefreshRequired()
{
   if(mHaveAllocation && (time(0) >= mAllocationRefreshTime))
   {
      // Do refresh
      return refreshAllocation();
   }
   return asio::error_code();  // 0
}

StunMessage* 
TurnSocket::sendRequestAndGetResponse(StunMessage& request, asio::error_code& errorCode)
{
   unsigned int writesize = request.stunEncodeFramedMessage(mWriteBuffer, sizeof(mWriteBuffer));
   bool sendRequest = true;
   bool reliableTransport = mLocalBinding.getTransportType() != StunTuple::UDP;
   unsigned int timeout = reliableTransport ? TCP_RESPONSE_TIME : UDP_RT0;
   unsigned int totalTime = 0;
   unsigned int requestsSent = 0;
   unsigned int readsize = 0;

   while(true)
   {
      if(sendRequest)
      {
         // Send request to Turn Server
         if(requestsSent > 0)
         {
            DebugLog(<< "TurnSocket: retranmitting request...");
         }
         requestsSent++;
         errorCode = rawWrite(mWriteBuffer, writesize);
         if(errorCode)
         {
            return 0;
         }
         sendRequest = false;
      }

      // Wait for response
      errorCode = rawRead(timeout, &readsize);
      if(errorCode)
      {
         if(errorCode == asio::error::operation_aborted)
         {
            totalTime += timeout;
            if(reliableTransport || requestsSent == UDP_MAX_RETRANSMITS)
            {
               InfoLog(<< "Timed out waiting for Stun response!");
               errorCode = asio::error_code(reTurn::ResponseTimeout, asio::error::misc_category);
               return 0;
            }

            // timed out and should retransmit - calculate next timeout
            if(requestsSent == UDP_MAX_RETRANSMITS - 1)
            {
               timeout = UDP_FINAL_REQUEST_TIME;
            } 
            else
            {
               timeout = (timeout*2);
            }
            sendRequest = true;
            continue;
         }
         return 0;
      }

      if(readsize > 4)
      {
         unsigned short channelNumber;
         memcpy(&channelNumber, &mReadBuffer[0], 2);
         channelNumber = ntohs(channelNumber);

         if(channelNumber == 0) // Channel 0 is Stun/Turn messaging
         {
            StunMessage* response = new StunMessage(mLocalBinding, mConnectedTuple, &mReadBuffer[4], readsize-4);

            if(response->isValid())
            {
               if(!response->checkMessageIntegrity(request.mHmacKey))
               {
                  WarningLog(<< "Stun response message integrity is bad!");
                  delete response;
                  errorCode = asio::error_code(reTurn::BadMessageIntegrity, asio::error::misc_category);
                  return 0;
               }
   
               // Check that TID matches request
               if(!(response->mHeader.magicCookieAndTid == request.mHeader.magicCookieAndTid))
               {
                  InfoLog(<< "Stun response TID does not match request - discarding!");
                  delete response;
                  continue;  // read next message
               }
   
               errorCode = asio::error_code(reTurn::Success, asio::error::misc_category);
               return response;
            }
            else
            {
               WarningLog(<< "Stun response message is invalid!");
               delete response;
               errorCode = asio::error_code(reTurn::ErrorParsingMessage, asio::error::misc_category);  
               return 0;
            }
         }
         else  // Channel != 0 indicates Turn Data
         {
            // TODO - handle buffering of Turn data that is receive while waiting for a Request/Response
            errorCode = asio::error_code(reTurn::FrameError, asio::error::misc_category);  
            return 0;
         }
      }
      else
      {
         // Less data than frame size received
         errorCode = asio::error_code(reTurn::FrameError, asio::error::misc_category);  
         return 0;
      }
   }
}

} // namespace


/* ====================================================================

 Original contribution Copyright (C) 2007 Plantronics, Inc.
 Provided under the terms of the Vovida Software License, Version 2.0.

 The Vovida Software License, Version 2.0 
 
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    notice, this list of conditions and the following disclaimer.
 
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    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution. 
 
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 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
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 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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