danicoin/src/common/dns_utils.h
Thomas Winget 1dece111cc Added function to check syntax of URL for DNS lookup
For now, simply checks for '.' character, but that will be easy to
change in the future if necessary/desired.
2014-09-23 22:59:57 +02:00

117 lines
3.7 KiB
C++

// Copyright (c) 2014, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#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