diff options
Diffstat (limited to 'doq.cc')
| -rw-r--r-- | doq.cc | 822 |
1 files changed, 822 insertions, 0 deletions
@@ -0,0 +1,822 @@ +/* + * This file is part of PowerDNS or dnsdist. + * Copyright -- PowerDNS.COM B.V. and its contributors + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * In addition, for the avoidance of any doubt, permission is granted to + * link this program with OpenSSL and to (re)distribute the binaries + * produced as the result of such linking. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "doq.hh" + +#ifdef HAVE_DNS_OVER_QUIC +#include <quiche.h> + +#include "dolog.hh" +#include "iputils.hh" +#include "misc.hh" +#include "sstuff.hh" +#include "threadname.hh" + +#include "dnsdist-dnsparser.hh" +#include "dnsdist-ecs.hh" +#include "dnsdist-proxy-protocol.hh" +#include "dnsdist-tcp.hh" +#include "dnsdist-random.hh" + +#include "doq-common.hh" + +using namespace dnsdist::doq; + +#if 0 +#define DEBUGLOG_ENABLED +#define DEBUGLOG(x) std::cerr << x << std::endl; +#else +#define DEBUGLOG(x) +#endif + +class Connection +{ +public: + Connection(const ComboAddress& peer, QuicheConfig config, QuicheConnection conn) : + d_peer(peer), d_conn(std::move(conn)), d_config(std::move(config)) + { + } + Connection(const Connection&) = delete; + Connection(Connection&&) = default; + Connection& operator=(const Connection&) = delete; + Connection& operator=(Connection&&) = default; + ~Connection() = default; + + ComboAddress d_peer; + QuicheConnection d_conn; + QuicheConfig d_config; + + std::unordered_map<uint64_t, PacketBuffer> d_streamBuffers; + std::unordered_map<uint64_t, PacketBuffer> d_streamOutBuffers; +}; + +static void sendBackDOQUnit(DOQUnitUniquePtr&& unit, const char* description); + +struct DOQServerConfig +{ + DOQServerConfig(QuicheConfig&& config_, uint32_t internalPipeBufferSize) : + config(std::move(config_)) + { + { + auto [sender, receiver] = pdns::channel::createObjectQueue<DOQUnit>(pdns::channel::SenderBlockingMode::SenderNonBlocking, pdns::channel::ReceiverBlockingMode::ReceiverNonBlocking, internalPipeBufferSize); + d_responseSender = std::move(sender); + d_responseReceiver = std::move(receiver); + } + } + DOQServerConfig(const DOQServerConfig&) = delete; + DOQServerConfig(DOQServerConfig&&) = default; + DOQServerConfig& operator=(const DOQServerConfig&) = delete; + DOQServerConfig& operator=(DOQServerConfig&&) = default; + ~DOQServerConfig() = default; + + using ConnectionsMap = std::map<PacketBuffer, Connection>; + + LocalHolders holders; + ConnectionsMap d_connections; + QuicheConfig config; + ClientState* clientState{nullptr}; + std::shared_ptr<DOQFrontend> df{nullptr}; + pdns::channel::Sender<DOQUnit> d_responseSender; + pdns::channel::Receiver<DOQUnit> d_responseReceiver; +}; + +/* these might seem useless, but they are needed because + they need to be declared _after_ the definition of DOQServerConfig + so that we can use a unique_ptr in DOQFrontend */ +DOQFrontend::DOQFrontend() = default; +DOQFrontend::~DOQFrontend() = default; + +class DOQTCPCrossQuerySender final : public TCPQuerySender +{ +public: + DOQTCPCrossQuerySender() = default; + + [[nodiscard]] bool active() const override + { + return true; + } + + void handleResponse([[maybe_unused]] const struct timeval& now, TCPResponse&& response) override + { + if (!response.d_idstate.doqu) { + return; + } + + auto unit = std::move(response.d_idstate.doqu); + if (unit->dsc == nullptr) { + return; + } + + unit->response = std::move(response.d_buffer); + unit->ids = std::move(response.d_idstate); + DNSResponse dnsResponse(unit->ids, unit->response, unit->downstream); + + dnsheader cleartextDH{}; + memcpy(&cleartextDH, dnsResponse.getHeader().get(), sizeof(cleartextDH)); + + if (!response.isAsync()) { + + static thread_local LocalStateHolder<vector<DNSDistResponseRuleAction>> localRespRuleActions = g_respruleactions.getLocal(); + static thread_local LocalStateHolder<vector<DNSDistResponseRuleAction>> localCacheInsertedRespRuleActions = g_cacheInsertedRespRuleActions.getLocal(); + + dnsResponse.ids.doqu = std::move(unit); + + if (!processResponse(dnsResponse.ids.doqu->response, *localRespRuleActions, *localCacheInsertedRespRuleActions, dnsResponse, false)) { + if (dnsResponse.ids.doqu) { + + sendBackDOQUnit(std::move(dnsResponse.ids.doqu), "Response dropped by rules"); + } + return; + } + + if (dnsResponse.isAsynchronous()) { + return; + } + + unit = std::move(dnsResponse.ids.doqu); + } + + if (!unit->ids.selfGenerated) { + double udiff = unit->ids.queryRealTime.udiff(); + vinfolog("Got answer from %s, relayed to %s (quic, %d bytes), took %f us", unit->downstream->d_config.remote.toStringWithPort(), unit->ids.origRemote.toStringWithPort(), unit->response.size(), udiff); + + auto backendProtocol = unit->downstream->getProtocol(); + if (backendProtocol == dnsdist::Protocol::DoUDP && unit->tcp) { + backendProtocol = dnsdist::Protocol::DoTCP; + } + handleResponseSent(unit->ids, udiff, unit->ids.origRemote, unit->downstream->d_config.remote, unit->response.size(), cleartextDH, backendProtocol, true); + } + + ++dnsdist::metrics::g_stats.responses; + if (unit->ids.cs != nullptr) { + ++unit->ids.cs->responses; + } + + sendBackDOQUnit(std::move(unit), "Cross-protocol response"); + } + + void handleXFRResponse(const struct timeval& now, TCPResponse&& response) override + { + return handleResponse(now, std::move(response)); + } + + void notifyIOError([[maybe_unused]] const struct timeval& now, TCPResponse&& response) override + { + if (!response.d_idstate.doqu) { + return; + } + + auto unit = std::move(response.d_idstate.doqu); + if (unit->dsc == nullptr) { + return; + } + + /* this will signal an error */ + unit->response.clear(); + unit->ids = std::move(response.d_idstate); + sendBackDOQUnit(std::move(unit), "Cross-protocol error"); + } +}; + +class DOQCrossProtocolQuery : public CrossProtocolQuery +{ +public: + DOQCrossProtocolQuery(DOQUnitUniquePtr&& unit, bool isResponse) + { + if (isResponse) { + /* happens when a response becomes async */ + query = InternalQuery(std::move(unit->response), std::move(unit->ids)); + } + else { + /* we need to duplicate the query here because we might need + the existing query later if we get a truncated answer */ + query = InternalQuery(PacketBuffer(unit->query), std::move(unit->ids)); + } + + /* it might have been moved when we moved unit->ids */ + if (unit) { + query.d_idstate.doqu = std::move(unit); + } + + /* we _could_ remove it from the query buffer and put in query's d_proxyProtocolPayload, + clearing query.d_proxyProtocolPayloadAdded and unit->proxyProtocolPayloadSize. + Leave it for now because we know that the onky case where the payload has been + added is when we tried over UDP, got a TC=1 answer and retried over TCP/DoT, + and we know the TCP/DoT code can handle it. */ + query.d_proxyProtocolPayloadAdded = query.d_idstate.doqu->proxyProtocolPayloadSize > 0; + downstream = query.d_idstate.doqu->downstream; + } + + void handleInternalError() + { + sendBackDOQUnit(std::move(query.d_idstate.doqu), "DOQ internal error"); + } + + std::shared_ptr<TCPQuerySender> getTCPQuerySender() override + { + query.d_idstate.doqu->downstream = downstream; + return s_sender; + } + + DNSQuestion getDQ() override + { + auto& ids = query.d_idstate; + DNSQuestion dnsQuestion(ids, query.d_buffer); + return dnsQuestion; + } + + DNSResponse getDR() override + { + auto& ids = query.d_idstate; + DNSResponse dnsResponse(ids, query.d_buffer, downstream); + return dnsResponse; + } + + DOQUnitUniquePtr&& releaseDU() + { + return std::move(query.d_idstate.doqu); + } + +private: + static std::shared_ptr<DOQTCPCrossQuerySender> s_sender; +}; + +std::shared_ptr<DOQTCPCrossQuerySender> DOQCrossProtocolQuery::s_sender = std::make_shared<DOQTCPCrossQuerySender>(); + +static bool tryWriteResponse(Connection& conn, const uint64_t streamID, PacketBuffer& response) +{ + size_t pos = 0; + while (pos < response.size()) { + auto res = quiche_conn_stream_send(conn.d_conn.get(), streamID, &response.at(pos), response.size() - pos, true); + if (res == QUICHE_ERR_DONE) { + response.erase(response.begin(), response.begin() + static_cast<ssize_t>(pos)); + return false; + } + if (res < 0) { + quiche_conn_stream_shutdown(conn.d_conn.get(), streamID, QUICHE_SHUTDOWN_WRITE, static_cast<uint64_t>(DOQ_Error_Codes::DOQ_INTERNAL_ERROR)); + return true; + } + pos += res; + } + + return true; +} + +static void handleResponse(DOQFrontend& frontend, Connection& conn, const uint64_t streamID, PacketBuffer& response) +{ + if (response.empty()) { + ++frontend.d_errorResponses; + quiche_conn_stream_shutdown(conn.d_conn.get(), streamID, QUICHE_SHUTDOWN_WRITE, static_cast<uint64_t>(DOQ_Error_Codes::DOQ_UNSPECIFIED_ERROR)); + return; + } + ++frontend.d_validResponses; + auto responseSize = static_cast<uint16_t>(response.size()); + const std::array<uint8_t, 2> sizeBytes = {static_cast<uint8_t>(responseSize / 256), static_cast<uint8_t>(responseSize % 256)}; + response.insert(response.begin(), sizeBytes.begin(), sizeBytes.end()); + if (!tryWriteResponse(conn, streamID, response)) { + conn.d_streamOutBuffers[streamID] = std::move(response); + } +} + +void DOQFrontend::setup() +{ + auto config = QuicheConfig(quiche_config_new(QUICHE_PROTOCOL_VERSION), quiche_config_free); + d_quicheParams.d_alpn = std::string(DOQ_ALPN.begin(), DOQ_ALPN.end()); + configureQuiche(config, d_quicheParams, false); + d_server_config = std::make_unique<DOQServerConfig>(std::move(config), d_internalPipeBufferSize); +} + +void DOQFrontend::reloadCertificates() +{ + auto config = QuicheConfig(quiche_config_new(QUICHE_PROTOCOL_VERSION), quiche_config_free); + d_quicheParams.d_alpn = std::string(DOQ_ALPN.begin(), DOQ_ALPN.end()); + configureQuiche(config, d_quicheParams, false); + std::atomic_store_explicit(&d_server_config->config, std::move(config), std::memory_order_release); +} + +static std::optional<std::reference_wrapper<Connection>> getConnection(DOQServerConfig::ConnectionsMap& connMap, const PacketBuffer& connID) +{ + auto iter = connMap.find(connID); + if (iter == connMap.end()) { + return std::nullopt; + } + return iter->second; +} + +static void sendBackDOQUnit(DOQUnitUniquePtr&& unit, const char* description) +{ + if (unit->dsc == nullptr) { + return; + } + try { + if (!unit->dsc->d_responseSender.send(std::move(unit))) { + ++dnsdist::metrics::g_stats.doqResponsePipeFull; + vinfolog("Unable to pass a %s to the DoQ worker thread because the pipe is full", description); + } + } + catch (const std::exception& e) { + vinfolog("Unable to pass a %s to the DoQ worker thread because we couldn't write to the pipe: %s", description, e.what()); + } +} + +static std::optional<std::reference_wrapper<Connection>> createConnection(DOQServerConfig& config, const PacketBuffer& serverSideID, const PacketBuffer& originalDestinationID, const ComboAddress& local, const ComboAddress& peer) +{ + auto quicheConfig = std::atomic_load_explicit(&config.config, std::memory_order_acquire); + auto quicheConn = QuicheConnection(quiche_accept(serverSideID.data(), serverSideID.size(), + originalDestinationID.data(), originalDestinationID.size(), + // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast) + reinterpret_cast<const struct sockaddr*>(&local), + local.getSocklen(), + // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast) + reinterpret_cast<const struct sockaddr*>(&peer), + peer.getSocklen(), + quicheConfig.get()), + quiche_conn_free); + + if (config.df && !config.df->d_quicheParams.d_keyLogFile.empty()) { + quiche_conn_set_keylog_path(quicheConn.get(), config.df->d_quicheParams.d_keyLogFile.c_str()); + } + + auto conn = Connection(peer, std::move(quicheConfig), std::move(quicheConn)); + auto pair = config.d_connections.emplace(serverSideID, std::move(conn)); + return pair.first->second; +} + +std::unique_ptr<CrossProtocolQuery> getDOQCrossProtocolQueryFromDQ(DNSQuestion& dnsQuestion, bool isResponse) +{ + if (!dnsQuestion.ids.doqu) { + throw std::runtime_error("Trying to create a DoQ cross protocol query without a valid DoQ unit"); + } + + auto unit = std::move(dnsQuestion.ids.doqu); + if (&dnsQuestion.ids != &unit->ids) { + unit->ids = std::move(dnsQuestion.ids); + } + + unit->ids.origID = dnsQuestion.getHeader()->id; + + if (!isResponse) { + if (unit->query.data() != dnsQuestion.getMutableData().data()) { + unit->query = std::move(dnsQuestion.getMutableData()); + } + } + else { + if (unit->response.data() != dnsQuestion.getMutableData().data()) { + unit->response = std::move(dnsQuestion.getMutableData()); + } + } + + return std::make_unique<DOQCrossProtocolQuery>(std::move(unit), isResponse); +} + +static void processDOQQuery(DOQUnitUniquePtr&& doqUnit) +{ + const auto handleImmediateResponse = [](DOQUnitUniquePtr&& unit, [[maybe_unused]] const char* reason) { + DEBUGLOG("handleImmediateResponse() reason=" << reason); + auto conn = getConnection(unit->dsc->df->d_server_config->d_connections, unit->serverConnID); + handleResponse(*unit->dsc->df, *conn, unit->streamID, unit->response); + unit->ids.doqu.reset(); + }; + + auto& ids = doqUnit->ids; + ids.doqu = std::move(doqUnit); + auto& unit = ids.doqu; + uint16_t queryId = 0; + ComboAddress remote; + + try { + + remote = unit->ids.origRemote; + DOQServerConfig* dsc = unit->dsc; + auto& holders = dsc->holders; + ClientState& clientState = *dsc->clientState; + + if (!holders.acl->match(remote)) { + vinfolog("Query from %s (DoQ) dropped because of ACL", remote.toStringWithPort()); + ++dnsdist::metrics::g_stats.aclDrops; + unit->response.clear(); + + handleImmediateResponse(std::move(unit), "DoQ query dropped because of ACL"); + return; + } + + if (unit->query.size() < sizeof(dnsheader)) { + ++dnsdist::metrics::g_stats.nonCompliantQueries; + ++clientState.nonCompliantQueries; + unit->response.clear(); + + handleImmediateResponse(std::move(unit), "DoQ non-compliant query"); + return; + } + + ++clientState.queries; + ++dnsdist::metrics::g_stats.queries; + unit->ids.queryRealTime.start(); + + { + /* don't keep that pointer around, it will be invalidated if the buffer is ever resized */ + dnsheader_aligned dnsHeader(unit->query.data()); + + if (!checkQueryHeaders(*dnsHeader, clientState)) { + dnsdist::PacketMangling::editDNSHeaderFromPacket(unit->query, [](dnsheader& header) { + header.rcode = RCode::ServFail; + header.qr = true; + return true; + }); + unit->response = std::move(unit->query); + + handleImmediateResponse(std::move(unit), "DoQ invalid headers"); + return; + } + + if (dnsHeader->qdcount == 0) { + dnsdist::PacketMangling::editDNSHeaderFromPacket(unit->query, [](dnsheader& header) { + header.rcode = RCode::NotImp; + header.qr = true; + return true; + }); + unit->response = std::move(unit->query); + + handleImmediateResponse(std::move(unit), "DoQ empty query"); + return; + } + + queryId = ntohs(dnsHeader->id); + } + + auto downstream = unit->downstream; + // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast) + unit->ids.qname = DNSName(reinterpret_cast<const char*>(unit->query.data()), static_cast<int>(unit->query.size()), sizeof(dnsheader), false, &unit->ids.qtype, &unit->ids.qclass); + DNSQuestion dnsQuestion(unit->ids, unit->query); + dnsdist::PacketMangling::editDNSHeaderFromPacket(dnsQuestion.getMutableData(), [&ids](dnsheader& header) { + const uint16_t* flags = getFlagsFromDNSHeader(&header); + ids.origFlags = *flags; + return true; + }); + unit->ids.cs = &clientState; + + auto result = processQuery(dnsQuestion, holders, downstream); + if (result == ProcessQueryResult::Drop) { + handleImmediateResponse(std::move(unit), "DoQ dropped query"); + return; + } + if (result == ProcessQueryResult::Asynchronous) { + return; + } + if (result == ProcessQueryResult::SendAnswer) { + if (unit->response.empty()) { + unit->response = std::move(unit->query); + } + if (unit->response.size() >= sizeof(dnsheader)) { + const dnsheader_aligned dnsHeader(unit->response.data()); + + handleResponseSent(unit->ids.qname, QType(unit->ids.qtype), 0., unit->ids.origDest, ComboAddress(), unit->response.size(), *dnsHeader, dnsdist::Protocol::DoQ, dnsdist::Protocol::DoQ, false); + } + handleImmediateResponse(std::move(unit), "DoQ self-answered response"); + return; + } + + ++dnsdist::metrics::g_stats.responses; + if (unit->ids.cs != nullptr) { + ++unit->ids.cs->responses; + } + + if (result != ProcessQueryResult::PassToBackend) { + handleImmediateResponse(std::move(unit), "DoQ no backend available"); + return; + } + + if (downstream == nullptr) { + handleImmediateResponse(std::move(unit), "DoQ no backend available"); + return; + } + + unit->downstream = downstream; + + std::string proxyProtocolPayload; + /* we need to do this _before_ creating the cross protocol query because + after that the buffer will have been moved */ + if (downstream->d_config.useProxyProtocol) { + proxyProtocolPayload = getProxyProtocolPayload(dnsQuestion); + } + + unit->ids.origID = htons(queryId); + unit->tcp = true; + + /* this moves unit->ids, careful! */ + auto cpq = std::make_unique<DOQCrossProtocolQuery>(std::move(unit), false); + cpq->query.d_proxyProtocolPayload = std::move(proxyProtocolPayload); + + if (downstream->passCrossProtocolQuery(std::move(cpq))) { + return; + } + // NOLINTNEXTLINE(bugprone-use-after-move): it was only moved if the call succeeded + unit = cpq->releaseDU(); + handleImmediateResponse(std::move(unit), "DoQ internal error"); + return; + } + catch (const std::exception& e) { + vinfolog("Got an error in DOQ question thread while parsing a query from %s, id %d: %s", remote.toStringWithPort(), queryId, e.what()); + handleImmediateResponse(std::move(unit), "DoQ internal error"); + return; + } +} + +static void doq_dispatch_query(DOQServerConfig& dsc, PacketBuffer&& query, const ComboAddress& local, const ComboAddress& remote, const PacketBuffer& serverConnID, const uint64_t streamID) +{ + try { + auto unit = std::make_unique<DOQUnit>(std::move(query)); + unit->dsc = &dsc; + unit->ids.origDest = local; + unit->ids.origRemote = remote; + unit->ids.protocol = dnsdist::Protocol::DoQ; + unit->serverConnID = serverConnID; + unit->streamID = streamID; + + processDOQQuery(std::move(unit)); + } + catch (const std::exception& exp) { + vinfolog("Had error handling DoQ DNS packet from %s: %s", remote.toStringWithPort(), exp.what()); + } +} + +static void flushResponses(pdns::channel::Receiver<DOQUnit>& receiver) +{ + for (;;) { + try { + auto tmp = receiver.receive(); + if (!tmp) { + return; + } + + auto unit = std::move(*tmp); + auto conn = getConnection(unit->dsc->df->d_server_config->d_connections, unit->serverConnID); + if (conn) { + handleResponse(*unit->dsc->df, *conn, unit->streamID, unit->response); + } + } + catch (const std::exception& e) { + errlog("Error while processing response received over DoQ: %s", e.what()); + } + catch (...) { + errlog("Unspecified error while processing response received over DoQ"); + } + } +} + +static void flushStalledResponses(Connection& conn) +{ + for (auto streamIt = conn.d_streamOutBuffers.begin(); streamIt != conn.d_streamOutBuffers.end();) { + const auto& streamID = streamIt->first; + auto& response = streamIt->second; + if (quiche_conn_stream_writable(conn.d_conn.get(), streamID, response.size()) == 1) { + if (tryWriteResponse(conn, streamID, response)) { + streamIt = conn.d_streamOutBuffers.erase(streamIt); + continue; + } + } + ++streamIt; + } +} + +static void handleReadableStream(DOQFrontend& frontend, ClientState& clientState, Connection& conn, uint64_t streamID, const ComboAddress& client, const PacketBuffer& serverConnID) +{ + auto& streamBuffer = conn.d_streamBuffers[streamID]; + while (true) { + bool fin = false; + auto existingLength = streamBuffer.size(); + streamBuffer.resize(existingLength + 512); + auto received = quiche_conn_stream_recv(conn.d_conn.get(), streamID, + &streamBuffer.at(existingLength), 512, + &fin); + if (received == 0 || received == QUICHE_ERR_DONE) { + streamBuffer.resize(existingLength); + return; + } + if (received < 0) { + ++dnsdist::metrics::g_stats.nonCompliantQueries; + ++clientState.nonCompliantQueries; + quiche_conn_stream_shutdown(conn.d_conn.get(), streamID, QUICHE_SHUTDOWN_WRITE, static_cast<uint64_t>(DOQ_Error_Codes::DOQ_PROTOCOL_ERROR)); + return; + } + + streamBuffer.resize(existingLength + received); + if (fin) { + break; + } + } + + if (streamBuffer.size() < (sizeof(uint16_t) + sizeof(dnsheader))) { + ++dnsdist::metrics::g_stats.nonCompliantQueries; + ++clientState.nonCompliantQueries; + quiche_conn_stream_shutdown(conn.d_conn.get(), streamID, QUICHE_SHUTDOWN_WRITE, static_cast<uint64_t>(DOQ_Error_Codes::DOQ_PROTOCOL_ERROR)); + return; + } + + uint16_t payloadLength = streamBuffer.at(0) * 256 + streamBuffer.at(1); + streamBuffer.erase(streamBuffer.begin(), streamBuffer.begin() + 2); + if (payloadLength != streamBuffer.size()) { + ++dnsdist::metrics::g_stats.nonCompliantQueries; + ++clientState.nonCompliantQueries; + quiche_conn_stream_shutdown(conn.d_conn.get(), streamID, QUICHE_SHUTDOWN_WRITE, static_cast<uint64_t>(DOQ_Error_Codes::DOQ_PROTOCOL_ERROR)); + return; + } + DEBUGLOG("Dispatching query"); + doq_dispatch_query(*(frontend.d_server_config), std::move(streamBuffer), clientState.local, client, serverConnID, streamID); + conn.d_streamBuffers.erase(streamID); +} + +static void handleSocketReadable(DOQFrontend& frontend, ClientState& clientState, Socket& sock, PacketBuffer& buffer) +{ + // destination connection ID, will have to be sent as original destination connection ID + PacketBuffer serverConnID; + // source connection ID, will have to be sent as destination connection ID + PacketBuffer clientConnID; + PacketBuffer tokenBuf; + while (true) { + ComboAddress client; + buffer.resize(4096); + if (!sock.recvFromAsync(buffer, client) || buffer.empty()) { + return; + } + DEBUGLOG("Received DoQ datagram of size " << buffer.size() << " from " << client.toStringWithPort()); + + uint32_t version{0}; + uint8_t type{0}; + std::array<uint8_t, QUICHE_MAX_CONN_ID_LEN> scid{}; + size_t scid_len = scid.size(); + std::array<uint8_t, QUICHE_MAX_CONN_ID_LEN> dcid{}; + size_t dcid_len = dcid.size(); + std::array<uint8_t, MAX_TOKEN_LEN> token{}; + size_t token_len = token.size(); + + auto res = quiche_header_info(buffer.data(), buffer.size(), LOCAL_CONN_ID_LEN, + &version, &type, + scid.data(), &scid_len, + dcid.data(), &dcid_len, + token.data(), &token_len); + if (res != 0) { + DEBUGLOG("Error in quiche_header_info: " << res); + continue; + } + + serverConnID.assign(dcid.begin(), dcid.begin() + dcid_len); + clientConnID.assign(scid.begin(), scid.begin() + scid_len); + auto conn = getConnection(frontend.d_server_config->d_connections, serverConnID); + + if (!conn) { + DEBUGLOG("Connection not found"); + if (type != static_cast<uint8_t>(DOQ_Packet_Types::QUIC_PACKET_TYPE_INITIAL)) { + DEBUGLOG("Packet is not initial"); + continue; + } + + if (!quiche_version_is_supported(version)) { + DEBUGLOG("Unsupported version"); + ++frontend.d_doqUnsupportedVersionErrors; + handleVersionNegociation(sock, clientConnID, serverConnID, client, buffer); + continue; + } + + if (token_len == 0) { + /* stateless retry */ + DEBUGLOG("No token received"); + handleStatelessRetry(sock, clientConnID, serverConnID, client, version, buffer); + continue; + } + + tokenBuf.assign(token.begin(), token.begin() + token_len); + auto originalDestinationID = validateToken(tokenBuf, client); + if (!originalDestinationID) { + ++frontend.d_doqInvalidTokensReceived; + DEBUGLOG("Discarding invalid token"); + continue; + } + + DEBUGLOG("Creating a new connection"); + conn = createConnection(*frontend.d_server_config, serverConnID, *originalDestinationID, clientState.local, client); + if (!conn) { + continue; + } + } + DEBUGLOG("Connection found"); + quiche_recv_info recv_info = { + // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast) + reinterpret_cast<struct sockaddr*>(&client), + client.getSocklen(), + // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast) + reinterpret_cast<struct sockaddr*>(&clientState.local), + clientState.local.getSocklen(), + }; + + auto done = quiche_conn_recv(conn->get().d_conn.get(), buffer.data(), buffer.size(), &recv_info); + if (done < 0) { + continue; + } + + if (quiche_conn_is_established(conn->get().d_conn.get()) || quiche_conn_is_in_early_data(conn->get().d_conn.get())) { + auto readable = std::unique_ptr<quiche_stream_iter, decltype(&quiche_stream_iter_free)>(quiche_conn_readable(conn->get().d_conn.get()), quiche_stream_iter_free); + + uint64_t streamID = 0; + while (quiche_stream_iter_next(readable.get(), &streamID)) { + handleReadableStream(frontend, clientState, *conn, streamID, client, serverConnID); + } + + flushEgress(sock, conn->get().d_conn, client, buffer); + } + else { + DEBUGLOG("Connection not established"); + } + } +} + +// this is the entrypoint from dnsdist.cc +void doqThread(ClientState* clientState) +{ + try { + std::shared_ptr<DOQFrontend>& frontend = clientState->doqFrontend; + + frontend->d_server_config->clientState = clientState; + frontend->d_server_config->df = clientState->doqFrontend; + + setThreadName("dnsdist/doq"); + + Socket sock(clientState->udpFD); + sock.setNonBlocking(); + + auto mplexer = std::unique_ptr<FDMultiplexer>(FDMultiplexer::getMultiplexerSilent()); + + auto responseReceiverFD = frontend->d_server_config->d_responseReceiver.getDescriptor(); + mplexer->addReadFD(sock.getHandle(), [](int, FDMultiplexer::funcparam_t&) {}); + mplexer->addReadFD(responseReceiverFD, [](int, FDMultiplexer::funcparam_t&) {}); + std::vector<int> readyFDs; + PacketBuffer buffer(4096); + while (true) { + readyFDs.clear(); + mplexer->getAvailableFDs(readyFDs, 500); + + try { + if (std::find(readyFDs.begin(), readyFDs.end(), sock.getHandle()) != readyFDs.end()) { + handleSocketReadable(*frontend, *clientState, sock, buffer); + } + + if (std::find(readyFDs.begin(), readyFDs.end(), responseReceiverFD) != readyFDs.end()) { + flushResponses(frontend->d_server_config->d_responseReceiver); + } + + for (auto conn = frontend->d_server_config->d_connections.begin(); conn != frontend->d_server_config->d_connections.end();) { + quiche_conn_on_timeout(conn->second.d_conn.get()); + + flushEgress(sock, conn->second.d_conn, conn->second.d_peer, buffer); + + if (quiche_conn_is_closed(conn->second.d_conn.get())) { +#ifdef DEBUGLOG_ENABLED + quiche_stats stats; + quiche_path_stats path_stats; + + quiche_conn_stats(conn->second.d_conn.get(), &stats); + quiche_conn_path_stats(conn->second.d_conn.get(), 0, &path_stats); + + DEBUGLOG("Connection (DoQ) closed, recv=" << stats.recv << " sent=" << stats.sent << " lost=" << stats.lost << " rtt=" << path_stats.rtt << "ns cwnd=" << path_stats.cwnd); +#endif + conn = frontend->d_server_config->d_connections.erase(conn); + } + else { + flushStalledResponses(conn->second); + ++conn; + } + } + } + catch (const std::exception& exp) { + vinfolog("Caught exception in the main DoQ thread: %s", exp.what()); + } + catch (...) { + vinfolog("Unknown exception in the main DoQ thread"); + } + } + } + catch (const std::exception& e) { + DEBUGLOG("Caught fatal error in the main DoQ thread: " << e.what()); + } +} + +#endif /* HAVE_DNS_OVER_QUIC */ |