Method stateRecvIdentityResponse

Control/L3MobilityManagement.cpp:482–560

Receive the identity response which may be IMSI or IMEI

// Receive the identity response which may be IMSI or IMEI
MachineStatus LUStart::stateRecvIdentityResponse(const GSM::L3IdentityResponse *resp)
{
	//const GSM::L3IdentityResponse *resp = dynamic_cast<typeof(resp)>(l3msg);
	LOG(INFO) << *resp;
	MobileIDType idtype = resp->mobileID().type();
	// Meaningful IdentityResponse?

	// Store the result, even if it was not what we asked for.
	if (idtype == IMSIType) {
		string imsi = string(resp->mobileID().digits());

		{
			// Check for perfidy on the part of the MS.  We're checking that it did not send two different IMSIs in the same attempt,
			// something that will probably never happen.
			string prevImsi = getImsi();
			if (prevImsi.size() && prevImsi != imsi) {
				LOG(ERR) << "MS returned two different IMSIs";
				MMRejectCause failCause = L3RejectCause::InvalidMandatoryInformation;
				// There is no ludata()->store yet so just set it directly:
				gTMSITable.tmsiTabSetRejected(imsi,(int)failCause);
				// I dont know what the cause should be here, but if this ever happens, we dont care.
				channel()->l3sendm(L3LocationUpdatingReject(failCause));
				return closeChannel(L3RRCause::NormalEvent,RELEASE);
			}
		}

		tran()->setSubscriberImsi(imsi,false);
		//gMMLayer.mmBlockImsi(imsi);

		// If this is the second attempt, we could check if this IMSI matches what we had on record,
		// and if so just reject immediately, but this doesn't happen often and I'm just going to let it proceed again
		// with the whole registration process.
		LOG(DEBUG) <<LOGVAR(imsi) <<LOGVAR(ludata()->mSecondAttempt) <<LOGVAR(ludata()->mPrevRegisterAttemptImsi) <<LOGVAR(ludata()->getTmsiStatus());
		if (ludata()->mSecondAttempt == 0) {
			// The MS sent a TMSI that was unrecognized, so we queried for the IMSI.
			assert(ludata()->getTmsiStatus() == tmsiNone);
		} else {
			// The second attempt means that registration by TMSI failed, so we queried for the imsi.
			// If the IMSI matches what is in the TMSI table, it is a genuine failure.
			devassert(ludata()->mPrevRegisterAttemptImsi.size());
			if (ludata()->mPrevRegisterAttemptImsi == imsi) {
				// It was not a TMSI collision; this subscriber is really unauthorized.
				// The register procedure already called regSetFail.
				devassert(ludata()->mRegistrationResult.isValid());
				return callMachStart(new LUFinish(tran()));
			}
			// We already assigned the new imsi above.  We just fall through to try another registration.
			assert(ludata()->getTmsiStatus() == tmsiFailed);
		}
	} else if (idtype == IMEIType) {
		// We do not check whether the IMEI matches what we may have stored already because
		// we dont care if the user has switched their SIM card to a new handset.
		ludata()->store.setImei(string(resp->mobileID().digits()));
	} else {
		LOG(WARNING) << "MS Identity Response unexpected type: " << idtype;
		return MachineStatusOK;	// Just ignore it.  T3270 is still running.  Maybe it will return what we asked for later.
	}