NRF9160 DNS getaddrinfo error

RE: NRF9160 DNS getaddrinfo error

Lamdev — Tue, 13 Jun 2023 08:58:56 GMT

Hello,

Thanks for your help,

I found this solution that works great and come from Modem Shell example and more precisely in in sock folder.

I share solution maybe this can help someone.

int getIP_fromHost(void){
    
    // struct addrinfo res;
    // struct addrinfo hint;

    int err = -EINVAL;

    struct sock_info *socket_info = reserve_socket_id();
    if (socket_info == NULL) {
		printk("socket creation failed; MAX SOCKETS exceeeded");
        return 1;
	}

    /* Get address */
	err = sock_getaddrinfo(socket_info, 1, 2, "your_udp_server", 1800, 0);
	if (err) {
		printk("err get address : %d \r\n",err);
        return 1;
	}

    char addr_str[INET_ADDRSTRLEN];
    for (struct addrinfo *ai = socket_info->addrinfo; ai != NULL; ai = ai->ai_next) {
        zsock_inet_ntop(ai->ai_family, &((struct sockaddr_in *)ai->ai_addr)->sin_addr, addr_str, sizeof(addr_str));
       	printk("IP address: %s\n", addr_str);
    }

    strcpy(ip_UDPServer,addr_str);
    
    // Clean up.
    freeaddrinfo(socket_info->addrinfo); 

    return 0;
}

static struct sock_info *reserve_socket_id(void)
{
	struct sock_info *socket_info = NULL;
	int socket_id = 0;

	while (socket_id < MAX_SOCKETS) {
		if (!sockets[socket_id].in_use) {
			socket_info = &(sockets[socket_id]);
			//sock_info_clear(socket_info);

            //freeaddrinfo(socket_info->addrinfo);
            memset(socket_info, 0, sizeof(struct sock_info));
            socket_info->id = -1;
	        socket_info->fd = -1;
	        socket_info->log_receive_data = true;
	        socket_info->recv_data_len_expected = -1;
	        socket_info->recv_print_format = SOCK_RECV_PRINT_FORMAT_STR;


			socket_info->id = socket_id;
			socket_info->send_info.parent = socket_info;
			break;
		}
		socket_id++;
	}
	return socket_info;
}

static int sock_getaddrinfo(struct sock_info *socket_info, int family, int type, char *address, int port, int pdn_cid)
{
	int err;

	struct addrinfo hints = {
		.ai_family = AF_INET,       //1
		.ai_socktype = SOCK_DGRAM,  //2
        .ai_next = NULL,
        .ai_addr = NULL,
        .ai_protocol = 0   //any protocol
	};
		
    //char pdn_serv[12];
	//char *service = NULL;

	

	err = getaddrinfo(address, NULL, &hints, &socket_info->addrinfo);
		
    if (err) {
			if (err == DNS_EAI_SYSTEM) {
				printk("getaddrinfo() failed, err %d errno %d", err, errno);
			} else {
				printk("getaddrinfo() failed, err %d", err);
			}
			return -EADDRNOTAVAIL;
		}

	/* Set port to address info */
		
	((struct sockaddr_in *)socket_info->addrinfo->ai_addr)->sin_port =htons(1800);
		
	return 0;
}

Best reagrds,

Lam

RE: NRF9160 DNS getaddrinfo error

Charlie — Mon, 05 Jun 2023 16:58:10 GMT

Hi Lam,

I added the following codes(commented lines) in NCS240 nrf\samples\nrf9160\upd\src\main.c.

// #define DOMAIN_NAME "gate04.telemesure.net"

static int server_init(void)
{
	struct sockaddr_in *server4 = ((struct sockaddr_in *)&host_addr);

        // int err;
        // struct sockaddr_in *ipaddr;
        // uint8_t *ip;
        // struct addrinfo *result;
        // struct addrinfo hints = {
        //         .ai_family = AF_INET,      /* Allow IPv4 or IPv6 */
        //         .ai_socktype = SOCK_DGRAM, /* Datagram socket */
        //         .ai_protocol = 0          /* Any protocol */
        // };
        // char *service = NULL;
        // err = getaddrinfo(DOMAIN_NAME, service, &hints, &result);
        // if (err != 0) {
        //         printk("getaddrinfo, error: %d\n", err);
        // }
        // ipaddr = (struct sockaddr_in *)result->ai_addr;
	// ip = (uint8_t *)&(ipaddr->sin_addr.s_addr);
	// printk("Server IP address: %d.%d.%d.%d\n", ip[0], ip[1], ip[2], ip[3]);

	server4->sin_family = AF_INET;
	server4->sin_port = htons(CONFIG_UDP_SERVER_PORT);

	inet_pton(AF_INET, CONFIG_UDP_SERVER_ADDRESS_STATIC,
		  &server4->sin_addr);

	return 0;
}

and get the IP address 54.36.99.9 which is the same as what I get from PC ping command.

2023-06-05T16:51:48.374Z DEBUG modem << *** Booting Zephyr OS build v3.3.99-ncs1 ***
2023-06-05T16:51:48.380Z DEBUG modem << UDP sample has started
2023-06-05T16:51:51.377Z DEBUG modem << LTE cell changed: Cell ID: 51546114, Tracking area: 30601
2023-06-05T16:51:51.682Z DEBUG modem << RRC mode: Connected
2023-06-05T16:51:52.748Z DEBUG modem << Network registration status: Connected - home network
2023-06-05T16:51:52.764Z DEBUG modem << PSM parameter update: TAU: 3600, Active time: 0
2023-06-05T16:51:53.028Z DEBUG modem << Server IP address: 54.36.99.9

Remember to set CONFIG_SERIAL=y in prj.conf in order to get log printout.

Best regards,

Charlie

RE: NRF9160 DNS getaddrinfo error

Lamdev — Mon, 05 Jun 2023 07:50:59 GMT

Hi Charlie,

Yes the code running without error but the IP address that i receive not match on the address IP of my hostname.

host.slb.com is not my hostname but correspond to the ip adress that i get from the code but it's a wrong IP address.

Do i have something to configure to enable resolution of a hostname other than implement my code ?

My UDP server is : gate04.telemesure.net

Best regards,

Lam

RE: NRF9160 DNS getaddrinfo error

Charlie — Mon, 05 Jun 2023 07:35:55 GMT

Hi Lam,

I am not sure if I understand your questions correctly.

Do you mean you do not get an error report but can still not get IP from the host host.slb.com?

I tried to ping host.slb.com on my PC and it can not be found. Did you try another hostname like google.com?

Best regards,

Charlie

RE: NRF9160 DNS getaddrinfo error

Lamdev — Fri, 02 Jun 2023 12:25:59 GMT

Hi,

Thanks for your answer,

I don't have implement this function because i'm thinking i don't need to especially reserve a socket because i only use one.

Now, i have implement this function and i don't have any error and find an IP address for this hostname : host.slb.com

I don't know tis hostname and this not match to the hostname i configure at the start.

static struct sock_info *reserve_socket_id(void)
{
	struct sock_info *socket_info = NULL;
	int socket_id = 0;

	while (socket_id < MAX_SOCKETS) {
		if (!sockets[socket_id].in_use) {
			socket_info = &(sockets[socket_id]);
			//sock_info_clear(socket_info);

            freeaddrinfo(socket_info->addrinfo);
            memset(socket_info, 0, sizeof(struct sock_info));
            socket_info->id = -1;
	        socket_info->fd = -1;
	        socket_info->log_receive_data = true;
	        socket_info->recv_data_len_expected = -1;
	        socket_info->recv_print_format = SOCK_RECV_PRINT_FORMAT_STR;


			socket_info->id = socket_id;
			socket_info->send_info.parent = socket_info;
			break;
		}
		socket_id++;
	}
	return socket_info;
}

Do you have any advice ?

Best regards,

Lam

RE: NRF9160 DNS getaddrinfo error

Charlie — Fri, 02 Jun 2023 09:12:13 GMT

Hi Lamdev,

Looks "reserve_socket_id()" also does some initialization job for socke_info creation. Is there any special reason you comment it out?

Best regard,

Charlie