Openthread SRP/DNS/mDNS problem

[Alessio Galliazzo]

Hi Guys,

I'm working with a P-NUCLEO-WB55 traying to implement an OpenThread network. I'm using the latest stable software package (1.15.0) with STMCubeIDE.

I found some problem browsing response from the otDnsClientBrowse function. In particular, in the callback, otDnsBrowseResponseGetServiceName return  OT_ERROR_NONE but no data on the label (param. 1) is filled.

I tryed to initialize all the buffer to 0 and, after the call, the data is still 0.

I share the code in here to reproduce the problem:

otIp6Address otLocalMLEIDAddress;
 
void _CP_DNS_BrowseCallback(otError aError, const otDnsBrowseResponse *aResponse, void *aContext){
	#define LBL_LEN	255
	aError = aError;
	otError record_not_found = OT_ERROR_NONE;
	char label[LBL_LEN];
	char svc_name[LBL_LEN];
	uint16_t index = 0;
	otDnsServiceInfo s_info;
	otDnsBrowseResponseGetServiceName(aResponse, svc_name, LBL_LEN);
 
	if (aError == OT_ERROR_NONE){
		while(otDnsBrowseResponseGetServiceInstance(aResponse, index, label, LBL_LEN) == OT_ERROR_NONE){
			index ++;
			if(otDnsBrowseResponseGetServiceInfo(aResponse, label, &s_info) == OT_ERROR_NONE){
				if(strstr(label, "CoAP_MQTT_Bridge") != 0){
					memcpy(&otMainServerAddress, &s_info.mHostAddress, sizeof(otIp6Address));
					break;
				}
			}
		}
	} 
}
 
 
 
void CP_InitializeSRP_DNS(coap_protocol_info_t * ci) {
	otError error = OT_ERROR_NONE;
	otDnsTxtEntry txt_entry;
 
	_CP_GetOMR();
 
	// At this point, thanks to the call to _CP_GetOMR(),
	// otLocalMLEIDAddress should contain the OMR for the thread node
 
 
	// Registering the local service to the SRP server
	service.mInstanceName = ci->EUI64; // Let's start with the EUI64 as service name
	service.mName = "_coap._udp"; // I'm publishing a CoAP service
	service.mPort = OT_DEFAULT_COAP_PORT;
	service.mPriority = 1;
	service.mWeight = 1;
	service.mSubTypeLabels = NULL;
	service.mTxtEntries = &txt_entry; // This is a test I did, I need futher investigation about the utility in my case
	service.mNumTxtEntries = 1;
 
	otServiceConfig conf;
	otNetworkDataIterator it = 0;
	while (conf.mServiceData[0] != 0x5d) {
		error = otNetDataGetNextService(NULL, &it, &conf);
	}
 
	memcpy(&SRP.mAddress.mFields.m8, &conf.mServerConfig.mServerData, 16);
	SRP.mPort = conf.mServerConfig.mServerData[16] << 8 | conf.mServerConfig.mServerData[17];
	error = otSrpClientSetHostAddresses(NULL, &otLocalMLEIDAddress, 1);
	error = otSrpClientAddService(NULL, &service);
	error = otSrpClientSetHostName(NULL, ci->EUI64);
	error = otSrpClientStart(NULL, &SRP);
 
       // At this time the service is properly registered on the SRP server, we need to know if a CoAP to MQTT bridge is available in the network
 
	// Querying the server for a CoAP to MQTT bridge
 	otDnsQueryConfig * dns_cfg = otDnsClientGetDefaultConfig(NULL); 
 	dns_cfg->mMaxTxAttempts = 5;
 	dns_cfg->mResponseTimeout = 1000;
 	memcpy(&dns_cfg->mServerSockAddr, &SRP, sizeof(otSockAddr));
 	dns_cfg->mServerSockAddr.mPort = 53;
 	otDnsClientBrowse(NULL, "_coap._udp.default.service.arpa", _CP_DNS_BrowseCallback, ci, dns_cfg);
}

I tesded the CLI example you provide with the software pack and that works fine, I suppose the problem somewhere between the M4 and M0 core but, of course, I can be wrong!

If I'm doing something wrong please feel free to comment! I'm quite new to both OpenThread and STM32 microcontroller.

As you can see server is properly answering the DNS query as shown in the next picture

Also the DNS subsystem is active and I can enter the callback in debug, in the 

OpenThread_CallBack_Processing, case MSG_M0TOM4_DNS_BROWSE_CB the  p_notification->Data[1] that should contain the address of an otDnsBrowseResponse  pointer is set to 0x2003e3fc but if I check the value pointed I get a series of zeros:

Thanks in adavance

Alessio

[Alessio Galliazzo]

Sorry to bother again guys,

have anyone from ST some infos about? Is there a way I can get the sources for the wireless copro so I can check deeper in the debug?