dns.h

Go to the documentation of this file.

/*
 * Copyright (C) 2017 Kaspar Schleiser <kaspar@schleiser.de>
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */
 
#pragma once

 
#include <errno.h>
#include <stdint.h>
#include <unistd.h>
 
#include "net/dns/msg.h"
 
#include "net/sock/udp.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifdef MODULE_AUTO_INIT_SOCK_DNS
#ifndef CONFIG_AUTO_INIT_SOCK_DNS_IP_VERSION
    /* IPv6 is preferred */
    #if defined(SOCK_HAS_IPV6)
        #define CONFIG_AUTO_INIT_SOCK_DNS_IP_VERSION 6
    #elif defined(SOCK_HAS_IPV4)
        #define CONFIG_AUTO_INIT_SOCK_DNS_IP_VERSION 4
    #else
        #error "Neither IPv4 nor IPv6 included in build"
    #endif
#endif

#ifndef CONFIG_AUTO_INIT_SOCK_DNS_SERVER_ADDR
    /* Default to Quad9 Public DNS */
    #if CONFIG_AUTO_INIT_SOCK_DNS_IP_VERSION == 6
        #define CONFIG_AUTO_INIT_SOCK_DNS_SERVER_ADDR "2620:fe::fe"
    #elif CONFIG_AUTO_INIT_SOCK_DNS_IP_VERSION == 4
        #define CONFIG_AUTO_INIT_SOCK_DNS_SERVER_ADDR "9.9.9.9"
    #endif
#endif

#ifndef CONFIG_AUTO_INIT_SOCK_DNS_SERVER_PORT
#define CONFIG_AUTO_INIT_SOCK_DNS_SERVER_PORT SOCK_DNS_PORT
#endif
#endif /* MODULE_AUTO_INIT_SOCK_DNS */

#define SOCK_DNS_PORT           (53)
#define SOCK_DNS_RETRIES        (2)
 
#define SOCK_DNS_MAX_NAME_LEN   (CONFIG_DNS_MSG_LEN - sizeof(dns_hdr_t) - 4)

int sock_dns_query(const char *domain_name, void *addr_out, int family);

extern sock_udp_ep_t sock_dns_server;
 
#ifdef __cplusplus
}
#endif