diff --git a/src/common/dns_utils.cpp b/src/common/dns_utils.cpp index 6755a30b..60f00916 100644 --- a/src/common/dns_utils.cpp +++ b/src/common/dns_utils.cpp @@ -79,11 +79,16 @@ DNSResolver::~DNSResolver() std::vector DNSResolver::get_ipv4(const std::string& url) { + std::vector addresses; + + if (!check_address_syntax(url)) + { + return addresses; + } + // destructor takes care of cleanup ub_result_ptr result; - std::vector retval; - // call DNS resolver, blocking. if return value not zero, something went wrong if (!ub_resolve(m_data->m_ub_context, url.c_str(), LDNS_RR_TYPE_A, LDNS_RR_CLASS_IN, &(result.ptr))) { @@ -96,19 +101,25 @@ std::vector DNSResolver::get_ipv4(const std::string& url) // convert bytes to string, append if no error if (inet_ntop(AF_INET, result.ptr->data[i], as_str, sizeof(as_str))) { - retval.push_back(as_str); + addresses.push_back(as_str); } } } } - return retval; + return addresses; } std::vector DNSResolver::get_ipv6(const std::string& url) { + std::vector addresses; + + if (!check_address_syntax(url)) + { + return addresses; + } + ub_result_ptr result; - std::vector retval; // call DNS resolver, blocking. if return value not zero, something went wrong if (!ub_resolve(m_data->m_ub_context, url.c_str(), LDNS_RR_TYPE_AAAA, LDNS_RR_CLASS_IN, &(result.ptr))) @@ -122,20 +133,26 @@ std::vector DNSResolver::get_ipv6(const std::string& url) // convert bytes to string, append if no error if (inet_ntop(AF_INET6, result.ptr->data[i], as_str, sizeof(as_str))) { - retval.push_back(as_str); + addresses.push_back(as_str); } } } } - return retval; + return addresses; } std::vector DNSResolver::get_txt_record(const std::string& url) { - ub_result_ptr result; std::vector records; + if (!check_address_syntax(url)) + { + return records; + } + + ub_result_ptr result; + // call DNS resolver, blocking. if return value not zero, something went wrong if (!ub_resolve(m_data->m_ub_context, url.c_str(), LDNS_RR_TYPE_TXT, LDNS_RR_CLASS_IN, &(result.ptr))) { @@ -161,4 +178,14 @@ DNSResolver& DNSResolver::instance() return *staticInstance; } +bool DNSResolver::check_address_syntax(const std::string& addr) +{ + // if string doesn't contain a dot, we won't consider it a url for now. + if (addr.find(".") == std::string::npos) + { + return false; + } + return true; +} + } // namespace tools diff --git a/src/common/dns_utils.h b/src/common/dns_utils.h index e57e5586..375f6ba3 100644 --- a/src/common/dns_utils.h +++ b/src/common/dns_utils.h @@ -101,6 +101,15 @@ public: 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