| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "dns_tls_frontend.h" |
| |
| #include <arpa/inet.h> |
| #include <netdb.h> |
| #include <openssl/err.h> |
| #include <openssl/evp.h> |
| #include <openssl/ssl.h> |
| #include <openssl/x509.h> |
| #include <sys/eventfd.h> |
| #include <sys/poll.h> |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #define LOG_TAG "DnsTlsFrontend" |
| #include <android-base/logging.h> |
| #include <netdutils/InternetAddresses.h> |
| #include <netdutils/SocketOption.h> |
| #include "dns_tls_certificate.h" |
| |
| using android::netdutils::enableSockopt; |
| using android::netdutils::ScopedAddrinfo; |
| |
| namespace { |
| static bssl::UniquePtr<X509> stringToX509Certs(const char* certs) { |
| bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(certs, strlen(certs))); |
| return bssl::UniquePtr<X509>(PEM_read_bio_X509(bio.get(), nullptr, nullptr, nullptr)); |
| } |
| |
| // Convert a string buffer containing an RSA Private Key into an OpenSSL RSA struct. |
| static bssl::UniquePtr<RSA> stringToRSAPrivateKey(const char* key) { |
| bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(key, strlen(key))); |
| return bssl::UniquePtr<RSA>(PEM_read_bio_RSAPrivateKey(bio.get(), nullptr, nullptr, nullptr)); |
| } |
| |
| std::string addr2str(const sockaddr* sa, socklen_t sa_len) { |
| char host_str[NI_MAXHOST] = {0}; |
| int rv = getnameinfo(sa, sa_len, host_str, sizeof(host_str), nullptr, 0, NI_NUMERICHOST); |
| if (rv == 0) return std::string(host_str); |
| return std::string(); |
| } |
| |
| } // namespace |
| |
| namespace test { |
| |
| bool DnsTlsFrontend::startServer() { |
| OpenSSL_add_ssl_algorithms(); |
| |
| // reset queries_ to 0 every time startServer called |
| // which would help us easy to check queries_ via calling waitForQueries |
| queries_ = 0; |
| |
| ctx_.reset(SSL_CTX_new(TLS_server_method())); |
| if (!ctx_) { |
| LOG(ERROR) << "SSL context creation failed"; |
| return false; |
| } |
| |
| SSL_CTX_set_ecdh_auto(ctx_.get(), 1); |
| |
| bssl::UniquePtr<X509> ca_certs(stringToX509Certs(kCertificate)); |
| if (!ca_certs) { |
| LOG(ERROR) << "StringToX509Certs failed"; |
| return false; |
| } |
| |
| if (SSL_CTX_use_certificate(ctx_.get(), ca_certs.get()) <= 0) { |
| LOG(ERROR) << "SSL_CTX_use_certificate failed"; |
| return false; |
| } |
| |
| bssl::UniquePtr<RSA> private_key(stringToRSAPrivateKey(kPrivatekey)); |
| if (SSL_CTX_use_RSAPrivateKey(ctx_.get(), private_key.get()) <= 0) { |
| LOG(ERROR) << "Error loading client RSA Private Key data."; |
| return false; |
| } |
| |
| // Set up TCP server socket for clients. |
| addrinfo frontend_ai_hints{ |
| .ai_flags = AI_PASSIVE, |
| .ai_family = AF_UNSPEC, |
| .ai_socktype = SOCK_STREAM, |
| }; |
| addrinfo* frontend_ai_res = nullptr; |
| int rv = getaddrinfo(listen_address_.c_str(), listen_service_.c_str(), &frontend_ai_hints, |
| &frontend_ai_res); |
| ScopedAddrinfo frontend_ai_res_cleanup(frontend_ai_res); |
| if (rv) { |
| LOG(ERROR) << "frontend getaddrinfo(" << listen_address_.c_str() << ", " |
| << listen_service_.c_str() << ") failed: " << gai_strerror(rv); |
| return false; |
| } |
| |
| for (const addrinfo* ai = frontend_ai_res; ai; ai = ai->ai_next) { |
| android::base::unique_fd s(socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol)); |
| if (s.get() < 0) { |
| PLOG(INFO) << "ignore creating socket failed " << s.get(); |
| continue; |
| } |
| enableSockopt(s.get(), SOL_SOCKET, SO_REUSEPORT).ignoreError(); |
| enableSockopt(s.get(), SOL_SOCKET, SO_REUSEADDR).ignoreError(); |
| std::string host_str = addr2str(ai->ai_addr, ai->ai_addrlen); |
| if (bind(s.get(), ai->ai_addr, ai->ai_addrlen)) { |
| PLOG(INFO) << "failed to bind TCP " << host_str.c_str() << ":" |
| << listen_service_.c_str(); |
| continue; |
| } |
| LOG(INFO) << "bound to TCP " << host_str.c_str() << ":" << listen_service_.c_str(); |
| socket_ = std::move(s); |
| break; |
| } |
| |
| if (listen(socket_.get(), 1) < 0) { |
| PLOG(INFO) << "failed to listen socket " << socket_.get(); |
| return false; |
| } |
| |
| // Set up UDP client socket to backend. |
| addrinfo backend_ai_hints{.ai_family = AF_UNSPEC, .ai_socktype = SOCK_DGRAM}; |
| addrinfo* backend_ai_res = nullptr; |
| rv = getaddrinfo(backend_address_.c_str(), backend_service_.c_str(), &backend_ai_hints, |
| &backend_ai_res); |
| ScopedAddrinfo backend_ai_res_cleanup(backend_ai_res); |
| if (rv) { |
| LOG(ERROR) << "backend getaddrinfo(" << listen_address_.c_str() << ", " |
| << listen_service_.c_str() << ") failed: " << gai_strerror(rv); |
| return false; |
| } |
| backend_socket_.reset(socket(backend_ai_res->ai_family, backend_ai_res->ai_socktype, |
| backend_ai_res->ai_protocol)); |
| if (backend_socket_.get() < 0) { |
| PLOG(INFO) << "backend socket " << backend_socket_.get() << " creation failed"; |
| return false; |
| } |
| |
| // connect() always fails in the test DnsTlsSocketTest.SlowDestructor because of |
| // no backend server. Don't check it. |
| connect(backend_socket_.get(), backend_ai_res->ai_addr, backend_ai_res->ai_addrlen); |
| |
| // Set up eventfd socket. |
| event_fd_.reset(eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC)); |
| if (event_fd_.get() == -1) { |
| PLOG(INFO) << "failed to create eventfd " << event_fd_.get(); |
| return false; |
| } |
| |
| { |
| std::lock_guard lock(update_mutex_); |
| handler_thread_ = std::thread(&DnsTlsFrontend::requestHandler, this); |
| } |
| LOG(INFO) << "server started successfully"; |
| return true; |
| } |
| |
| void DnsTlsFrontend::requestHandler() { |
| LOG(DEBUG) << "Request handler started"; |
| enum { EVENT_FD = 0, LISTEN_FD = 1 }; |
| pollfd fds[2] = {{.fd = event_fd_.get(), .events = POLLIN}, |
| {.fd = socket_.get(), .events = POLLIN}}; |
| android::base::unique_fd clientFd; |
| |
| while (true) { |
| int poll_code = poll(fds, std::size(fds), -1); |
| if (poll_code <= 0) { |
| PLOG(WARNING) << "Poll failed with error " << poll_code; |
| break; |
| } |
| |
| if (fds[EVENT_FD].revents & (POLLIN | POLLERR)) { |
| handleEventFd(); |
| break; |
| } |
| if (fds[LISTEN_FD].revents & (POLLIN | POLLERR)) { |
| sockaddr_storage addr; |
| socklen_t len = sizeof(addr); |
| |
| LOG(DEBUG) << "Trying to accept a client"; |
| android::base::unique_fd client( |
| accept4(socket_.get(), reinterpret_cast<sockaddr*>(&addr), &len, SOCK_CLOEXEC)); |
| if (client.get() < 0) { |
| // Stop |
| PLOG(INFO) << "failed to accept client socket " << client.get(); |
| break; |
| } |
| |
| if (hangOnHandshake_) { |
| LOG(DEBUG) << "TEST ONLY: unresponsive to SSL handshake"; |
| |
| // The previous fd already stored in clientFd will be closed automatically. |
| clientFd = std::move(client); |
| continue; |
| } |
| |
| bssl::UniquePtr<SSL> ssl(SSL_new(ctx_.get())); |
| SSL_set_fd(ssl.get(), client.get()); |
| |
| LOG(DEBUG) << "Doing SSL handshake"; |
| bool success = false; |
| if (SSL_accept(ssl.get()) <= 0) { |
| LOG(INFO) << "SSL negotiation failure"; |
| } else { |
| LOG(DEBUG) << "SSL handshake complete"; |
| success = handleOneRequest(ssl.get()); |
| } |
| |
| if (success) { |
| // Increment queries_ as late as possible, because it represents |
| // a query that is fully processed, and the response returned to the |
| // client, including cleanup actions. |
| ++queries_; |
| } |
| } |
| } |
| LOG(DEBUG) << "Ending loop"; |
| } |
| |
| bool DnsTlsFrontend::handleOneRequest(SSL* ssl) { |
| uint8_t queryHeader[2]; |
| if (SSL_read(ssl, &queryHeader, 2) != 2) { |
| LOG(INFO) << "Not enough header bytes"; |
| return false; |
| } |
| const uint16_t qlen = (queryHeader[0] << 8) | queryHeader[1]; |
| uint8_t query[qlen]; |
| size_t qbytes = 0; |
| while (qbytes < qlen) { |
| int ret = SSL_read(ssl, query + qbytes, qlen - qbytes); |
| if (ret <= 0) { |
| LOG(INFO) << "Error while reading query"; |
| return false; |
| } |
| qbytes += ret; |
| } |
| int sent = send(backend_socket_.get(), query, qlen, 0); |
| if (sent != qlen) { |
| LOG(INFO) << "Failed to send query"; |
| return false; |
| } |
| const int max_size = 4096; |
| uint8_t recv_buffer[max_size]; |
| int rlen = recv(backend_socket_.get(), recv_buffer, max_size, 0); |
| if (rlen <= 0) { |
| LOG(INFO) << "Failed to receive response"; |
| return false; |
| } |
| uint8_t responseHeader[2]; |
| responseHeader[0] = rlen >> 8; |
| responseHeader[1] = rlen; |
| if (SSL_write(ssl, responseHeader, 2) != 2) { |
| LOG(INFO) << "Failed to write response header"; |
| return false; |
| } |
| if (SSL_write(ssl, recv_buffer, rlen) != rlen) { |
| LOG(INFO) << "Failed to write response body"; |
| return false; |
| } |
| return true; |
| } |
| |
| bool DnsTlsFrontend::stopServer() { |
| std::lock_guard lock(update_mutex_); |
| if (!running()) { |
| LOG(INFO) << "server not running"; |
| return false; |
| } |
| |
| LOG(INFO) << "stopping frontend"; |
| if (!sendToEventFd()) { |
| return false; |
| } |
| handler_thread_.join(); |
| socket_.reset(); |
| backend_socket_.reset(); |
| event_fd_.reset(); |
| ctx_.reset(); |
| LOG(INFO) << "frontend stopped successfully"; |
| return true; |
| } |
| |
| // TODO: use a condition variable instead of polling |
| // TODO: also clear queries_ to eliminate potential race conditions |
| bool DnsTlsFrontend::waitForQueries(int expected_count) const { |
| constexpr int intervalMs = 20; |
| constexpr int timeoutMs = 5000; |
| int limit = timeoutMs / intervalMs; |
| for (int count = 0; count <= limit; ++count) { |
| bool done = queries_ >= expected_count; |
| // Always sleep at least one more interval after we are done, to wait for |
| // any immediate post-query actions that the client may take (such as |
| // marking this server as reachable during validation). |
| usleep(intervalMs * 1000); |
| if (done) { |
| // For ensuring that calls have sufficient headroom for slow machines |
| LOG(DEBUG) << "Query arrived in " << count << "/" << limit << " of allotted time"; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool DnsTlsFrontend::sendToEventFd() { |
| const uint64_t data = 1; |
| if (const ssize_t rt = write(event_fd_.get(), &data, sizeof(data)); rt != sizeof(data)) { |
| PLOG(INFO) << "failed to write eventfd, rt=" << rt; |
| return false; |
| } |
| return true; |
| } |
| |
| void DnsTlsFrontend::handleEventFd() { |
| int64_t data; |
| if (const ssize_t rt = read(event_fd_.get(), &data, sizeof(data)); rt != sizeof(data)) { |
| PLOG(INFO) << "ignore reading eventfd failed, rt=" << rt; |
| } |
| } |
| |
| } // namespace test |