C++ TransactionEntry::MTCSendTrying方法代码示例

bool SIPInterface::checkInvite( osip_message_t * msg)
{
	LOG(DEBUG);

	// This code dispatches new transactions coming from the network-side SIP interface.
	// All transactions originating here are going to be mobile-terminated.
	// Yes, this method is too long and needs to be broken up into smaller steps.

	// Is there even a method?
	const char *method = msg->sip_method;
	if (!method) return false;

	// Check for INVITE or MESSAGE methods.
	// Check channel availability now, too.
	GSM::ChannelType requiredChannel;
	bool channelAvailable = false;
	GSM::L3CMServiceType serviceType;
	// pretty sure strings are garbage collected
	string proxy = get_return_address(msg);
	if (strcmp(method,"INVITE") == 0) {
		// INVITE is for MTC.
		// Set the required channel type to match the assignment style.
		if (gConfig.defines("Control.VEA")) {
			// Very early assignment.
			requiredChannel = GSM::TCHFType;
			channelAvailable = gBTS.TCHAvailable();
		} else {
			// Early assignment
			requiredChannel = GSM::SDCCHType;
			channelAvailable = gBTS.SDCCHAvailable() && gBTS.TCHAvailable();
		}
		serviceType = L3CMServiceType::MobileTerminatedCall;
	}
	else if (strcmp(method,"MESSAGE") == 0) {
		// MESSAGE is for MTSMS.
		requiredChannel = GSM::SDCCHType;
		channelAvailable = gBTS.SDCCHAvailable();
		serviceType = L3CMServiceType::MobileTerminatedShortMessage;
	}
	else {
		// Not a method handled here.
		LOG(DEBUG) << "non-initiating SIP method " << method;
		return false;
	}

	// Get request username (IMSI) from invite. 
	const char* IMSI = extractIMSI(msg);
	if (!IMSI) {
		// FIXME -- Send appropriate error (404) on SIP interface.
		LOG(WARNING) << "Incoming INVITE/MESSAGE with no IMSI";
		return false;
	}
	L3MobileIdentity mobileID(IMSI);

	// Get the SIP call ID.
	const char * callIDNum = extractCallID(msg);	
	if (!callIDNum) {
		// FIXME -- Send appropriate error on SIP interface.
		LOG(WARNING) << "Incoming INVITE/MESSAGE with no call ID";
		return false;
	}


	// Find any active transaction for this IMSI with an assigned TCH or SDCCH.
	GSM::LogicalChannel *chan = gTransactionTable.findChannel(mobileID);
	if (chan) {
		// If the type is TCH and the service is SMS, get the SACCH.
		// Otherwise, for now, just say chan=NULL.
		if (serviceType==L3CMServiceType::MobileTerminatedShortMessage && chan->type()==FACCHType) {
			chan = chan->SACCH();
		} else {
			// FIXME -- This will change to support multiple transactions.
			chan = NULL;
		}
	}

	// Check SIP map.  Repeated entry?  Page again.
	if (mSIPMap.map().readNoBlock(callIDNum) != NULL) { 
		TransactionEntry* transaction= gTransactionTable.find(mobileID,callIDNum);
		// There's a FIFO but no trasnaction record?
		if (!transaction) {
			LOG(WARNING) << "repeated INVITE/MESSAGE with no transaction record";
			// Delete the bogus FIFO.
			mSIPMap.remove(callIDNum);
			return false;
		}
		// There is transaction already.  Send trying, if appropriate.
		if (serviceType!=L3CMServiceType::MobileTerminatedShortMessage) transaction->MTCSendTrying();
		// And if no channel is established yet, page again.
		if (!chan) {
			LOG(INFO) << "repeated SIP INVITE/MESSAGE, repaging for transaction " << *transaction; 
			gBTS.pager().addID(mobileID,requiredChannel,*transaction);
		}
		return false;
	}

	// So we will need a new channel.
	// Check gBTS for channel availability.
	if (!chan && !channelAvailable) {
		// FIXME -- Send 503 "Service Unavailable" response on SIP interface.
//.........这里部分代码省略.........