nrf_getaddrinfo() working example

[kratenko]

I'm using bsdlib (v0.7.7) on nrf9160 without Zephyr. Our products are working fine in the field, but so far you need to specify the host by IP address. I'm trying to implement add DNS using nrf_getaddrinfo() but I fail to get any useful response. I cannot find any example using nrf_getaddrinfo(), and the API docs don't really explain how to use any of the parameters.

	struct nrf_addrinfo hints;
	memset (&hints, 0, sizeof (hints));
	hints.ai_family = NRF_AF_INET;
	hints.ai_socktype = NRF_SOCK_STREAM;

	struct nrf_addrinfo *info;
	int got = nrf_getaddrinfo("<our-url-here>", "http", &hints, &info);

I tried some variations of the parameters. All I ever get in response is 22, which tells me "Invalid argument". So I guess I'm using some parameter incorrectly. But I failed in guessing so far.

Could you provide a very basic working example usinf nrf_getaddrinfo() that requests the IP4 for a given domain string, that shows how every parameter is set. ATM all I can think of is doing DNS myself using UDP, but I would rather use the implemented solution.

I'm doing this in Germany using a 1nce sim card, so it is using Deutsche Telekom.

Edit:

To be on the safe side, I included a call to nrf_setdnsaddr() on modem setup (call reports success).
I took the code from this answer: https://devzone.nordicsemi.com/f/nordic-q-a/50029/nrf9160-modem-firmware-v1-0-0-setting-custom-dns-server/235419#235419

	struct nrf_in_addr dns;
	dns.s_addr = 134744072; // Google DNS, 8.8.8.8
	const int err = nrf_setdnsaddr(NRF_AF_INET, &dns);
	Log("LTE| set DNS: %d\n", err);

[Didrik Rokhaug]

Hi kratenko,

We have no examples using bsdlib and nrf_sockets directly.

But, you can see how Zephyr's getaddrinfo parameters are translated in the link posted.

I can not remember seeing a sample where the service is set to anything else than NULL in NCS.

Best regards,

Didrik

[kratenko]

'm back on this issue over a year later. Still, nothing works for me and I fail to find any information on what I'm doing wrong.

I searched github for uses of `nrf_getaddrinfo()` - there are a few, and they do not seem to do anything different from my code, see this one, for example: https://github.com/machdep/nrf9160/blob/5a2113b19f60f69bccd3d2c33b06caf25b51ae3f/src/main.c#L239

Maybe there is some configuration or anything, that I need to do in the modem, before I can use this? But there is no information on that anywhere, and no documentation on this function to be found. All I get is errno 22 = `invalid argument` - which does not tell me anything.

Any Ideas?

[Didrik Rokhaug]

Hi,

Are you using NB-IoT?

If so, it might be that the network doesn't support ePCO, and therefore don't provide a DNS server to the device.

Could you try to use the %XEPCO AT command to configure the device to use "legacy" PCO?

Best regards,

Didrik