dns_responder: Wrap the response build into a function (c8913992) · Commits · e / os / android_packages_modules_DnsResolver

tests/dns_responder/dns_responder.cpp

+27 −21

Original line number	Diff line number	Diff line
		@@ -459,11 +459,11 @@ void DNSResponder::removeMapping(const std::string& name, ns_type type) {
		std::lock_guard lock(mappings_mutex_);
		auto it = mappings_.find(QueryKey(name, type));
		if (it != mappings_.end()) {
		LOG(ERROR) << "Cannot remove mapping mapping from (" << name << ", " << dnstype2str(type)
		<< "), not present";
		mappings_.erase(it);
		return;
		}
		mappings_.erase(it);
		LOG(ERROR) << "Cannot remove mapping from (" << name << ", " << dnstype2str(type)
		<< "), not present";
		}

		void DNSResponder::setResponseProbability(double response_probability) {
		@@ -667,24 +667,9 @@ bool DNSResponder::handleDNSRequest(const char* buffer, ssize_t len, char* respo
		}
		}

		for (const DNSQuestion& question : header.questions) {
		if (question.qclass != ns_class::ns_c_in && question.qclass != ns_class::ns_c_any) {
		LOG(INFO) << "unsupported question class " << question.qclass;
		return makeErrorResponse(&header, ns_rcode::ns_r_notimpl, response, response_len);
		}

		if (!addAnswerRecords(question, &header.answers)) {
		return makeErrorResponse(&header, ns_rcode::ns_r_servfail, response, response_len);
		}
		}

		header.qr = true;
		char* response_cur = header.write(response, response + *response_len);
		if (response_cur == nullptr) {
		return false;
		}
		*response_len = response_cur - response;
		return true;
		// Make the response. The query has been read into \|header\| which is used to build and return
		// the response as well.
		return makeResponse(&header, response, response_len);
		}

		bool DNSResponder::addAnswerRecords(const DNSQuestion& question,
		@@ -796,6 +781,27 @@ bool DNSResponder::makeErrorResponse(DNSHeader* header, ns_rcode rcode, char* re
		return true;
		}

		bool DNSResponder::makeResponse(DNSHeader* header, char* response, size_t* response_len) const {
		for (const DNSQuestion& question : header->questions) {
		if (question.qclass != ns_class::ns_c_in && question.qclass != ns_class::ns_c_any) {
		LOG(INFO) << "unsupported question class " << question.qclass;
		return makeErrorResponse(header, ns_rcode::ns_r_notimpl, response, response_len);
		}

		if (!addAnswerRecords(question, &header->answers)) {
		return makeErrorResponse(header, ns_rcode::ns_r_servfail, response, response_len);
		}
		}

		header->qr = true;
		char* response_cur = header->write(response, response + *response_len);
		if (response_cur == nullptr) {
		return false;
		}
		*response_len = response_cur - response;
		return true;
		}

		void DNSResponder::setDeferredResp(bool deferred_resp) {
		std::lock_guard<std::mutex> guard(cv_mutex_for_deferred_resp_);
		deferred_resp_ = deferred_resp;

tests/dns_responder/dns_responder.h

+8 −7

Original line number	Diff line number	Diff line
		@@ -116,6 +116,13 @@ inline const std::string kDefaultListenService = "53";
		*/
		class DNSResponder {
		public:
		enum class Edns : uint8_t {
		ON,
		FORMERR_ON_EDNS, // DNS server not supporting EDNS will reply FORMERR.
		FORMERR_UNCOND, // DNS server reply FORMERR unconditionally
		DROP // DNS server not supporting EDNS will not do any response.
		};

		DNSResponder(std::string listen_address = kDefaultListenAddr,
		std::string listen_service = kDefaultListenService,
		ns_rcode error_rcode = ns_rcode::ns_r_servfail);
		@@ -125,13 +132,6 @@ class DNSResponder {

		~DNSResponder();

		enum class Edns : uint8_t {
		ON,
		FORMERR_ON_EDNS, // DNS server not supporting EDNS will reply FORMERR.
		FORMERR_UNCOND, // DNS server reply FORMERR unconditionally
		DROP // DNS server not supporting EDNS will not do any response.
		};

		void addMapping(const std::string& name, ns_type type, const std::string& addr);
		void removeMapping(const std::string& name, ns_type type);
		void setResponseProbability(double response_probability);
		@@ -184,6 +184,7 @@ class DNSResponder {
		size_t* response_len) const;
		bool makeErrorResponse(DNSHeader* header, ns_rcode rcode, char* response,
		size_t* response_len) const;
		bool makeResponse(DNSHeader* header, char* response, size_t* response_len) const;

		// Add a new file descriptor to be polled by the handler thread.
		bool addFd(int fd, uint32_t events);