// Copyright (c) 2014, The Monero Project
//
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#include <vector>
#include <string>
namespace tools
{
struct DNSResolverData;
/**
* @brief Provides high-level access to DNS resolution
*
* This class is designed to provide a high-level abstraction to DNS resolution
* functionality, including access to TXT records and such. It will also
* handle DNSSEC validation of the results.
*/
class DNSResolver
{
public:
/**
* @brief Constructs an instance of DNSResolver
*
* Constructs a class instance and does setup stuff for the backend resolver.
*/
DNSResolver();
/**
* @brief takes care of freeing C pointers and such
*/
~DNSResolver();
/**
* @brief gets ipv4 addresses from DNS query of a URL
*
* returns a vector of all IPv4 "A" records for given URL.
* If no "A" records found, returns an empty vector.
*
* @param url A string containing a URL to query for
*
* @return vector of strings containing ipv4 addresses
*/
std::vector<std::string> get_ipv4(const std::string& url);
/**
* @brief gets ipv6 addresses from DNS query
*
* returns a vector of all IPv6 "A" records for given URL.
* If no "A" records found, returns an empty vector.
*
* @param url A string containing a URL to query for
*
* @return vector of strings containing ipv6 addresses
*/
std::vector<std::string> get_ipv6(const std::string& url);
/**
* @brief gets all TXT records from a DNS query for the supplied URL;
* if no TXT record present returns an empty vector.
*
* @param url A string containing a URL to query for
*
* @return A vector of strings containing a TXT record; or an empty vector
*/
// TODO: modify this to accomodate DNSSEC
std::vector<std::string> get_txt_record(const std::string& url);
/**
* @brief Gets the singleton instance of DNSResolver
*
* @return returns a pointer to the singleton
*/
static DNSResolver& instance();
private:
/**
* @brief Checks a string to see if it looks like a URL
*
* @param addr the string to be checked
*
* @return true if it looks enough like a URL, false if not
*/
bool check_address_syntax(const std::string& addr);
DNSResolverData *m_data;
}; // class DNSResolver
} // namespace tools
