From 0a41fd42aa43080fbc991e7d976dde70aeaec594 Mon Sep 17 00:00:00 2001 From: Stefan Boberg Date: Fri, 27 Feb 2026 17:13:40 +0100 Subject: add full WebSocket (RFC 6455) client/server support for zenhttp (#792) * This branch adds full WebSocket (RFC 6455) support to the HTTP server layer, covering both transport backends, a client, and tests. - **`websocket.h`** -- Core interfaces: `WebSocketOpcode`, `WebSocketMessage`, `WebSocketConnection` (ref-counted), and `IWebSocketHandler`. Services opt in to WebSocket support by implementing `IWebSocketHandler` alongside their existing `HttpService`. - **`httpwsclient.h`** -- `HttpWsClient`: an ASIO-backed `ws://` client with both standalone (own thread) and shared `io_context` modes. Supports connect timeout and optional auth token injection via `IWsClientHandler` callbacks. - **`wsasio.cpp/h`** -- `WsAsioConnection`: WebSocket over ASIO TCP. Takes over the socket after the HTTP 101 handshake and runs an async read/write loop with a queued write path (guarded by `RwLock`). - **`wshttpsys.cpp/h`** -- `WsHttpSysConnection`: WebSocket over http.sys opaque-mode connections (Windows only). Uses `HttpReceiveRequestEntityBody` / `HttpSendResponseEntityBody` via IOCP, sharing the same threadpool as normal http.sys traffic. Self-ref lifetime management ensures graceful drain of outstanding async ops. - **`httpsys_iocontext.h`** -- Tagged `OVERLAPPED` wrapper (`HttpSysIoContext`) used to distinguish normal HTTP transactions from WebSocket read/write completions in the single IOCP callback. - **`wsframecodec.cpp/h`** -- `WsFrameCodec`: static helpers for parsing (unmasked and masked) and building (unmasked server frames and masked client frames) RFC 6455 frames across all three payload length encodings (7-bit, 16-bit, 64-bit). Also computes `Sec-WebSocket-Accept` keys. - **`clients/httpwsclient.cpp`** -- `HttpWsClient::Impl`: ASIO-based client that performs the HTTP upgrade handshake, then hands off to the frame codec for the read loop. Manages its own `io_context` thread or plugs into an external one. - **`httpasio.cpp`** -- ASIO server now detects `Upgrade: websocket` requests, checks the matching `HttpService` for `IWebSocketHandler` via `dynamic_cast`, performs the RFC 6455 handshake (101 response), and spins up a `WsAsioConnection`. - **`httpsys.cpp`** -- Same upgrade detection and handshake logic for the http.sys backend, using `WsHttpSysConnection` and `HTTP_SEND_RESPONSE_FLAG_OPAQUE`. - **`httpparser.cpp/h`** -- Extended to surface the `Upgrade` / `Connection` / `Sec-WebSocket-Key` headers needed by the handshake. - **`httpcommon.h`** -- Minor additions (probably new header constants or response codes for the WS upgrade). - **`httpserver.h`** -- Small interface changes to support WebSocket registration. - **`zenhttp.cpp` / `xmake.lua`** -- New source files wired in; build config updated. - **Unit tests** (`websocket.framecodec`): round-trip encode/decode for text, binary, close frames; all three payload sizes; masked and unmasked variants; RFC 6455 `Sec-WebSocket-Accept` test vector. - **Integration tests** (`websocket.integration`): full ASIO server tests covering handshake (101), normal HTTP coexistence, echo, server-push broadcast, client close handshake, ping/pong auto-response, sequential messages, and rejection of upgrades on non-WS services. - **Client tests** (`websocket.client`): `HttpWsClient` connect+echo+close, connection failure (bad port -> close code 1006), and server-initiated close. * changed HttpRequestParser::ParseCurrentHeader to use switch instead of if/else chain * remove spurious printf --------- Co-authored-by: Stefan Boberg --- src/zenhttp/clients/httpwsclient.cpp | 568 +++++++++++++++++++++++++++++++++++ 1 file changed, 568 insertions(+) create mode 100644 src/zenhttp/clients/httpwsclient.cpp (limited to 'src/zenhttp/clients/httpwsclient.cpp') diff --git a/src/zenhttp/clients/httpwsclient.cpp b/src/zenhttp/clients/httpwsclient.cpp new file mode 100644 index 000000000..36a6f081b --- /dev/null +++ b/src/zenhttp/clients/httpwsclient.cpp @@ -0,0 +1,568 @@ +// Copyright Epic Games, Inc. All Rights Reserved. + +#include + +#include "../servers/wsframecodec.h" + +#include +#include +#include + +ZEN_THIRD_PARTY_INCLUDES_START +#include +ZEN_THIRD_PARTY_INCLUDES_END + +#include +#include +#include + +namespace zen { + +////////////////////////////////////////////////////////////////////////// + +struct HttpWsClient::Impl +{ + Impl(std::string_view Url, IWsClientHandler& Handler, const HttpWsClientSettings& Settings) + : m_Handler(Handler) + , m_Settings(Settings) + , m_Log(logging::Get(Settings.LogCategory)) + , m_OwnedIoContext(std::make_unique()) + , m_IoContext(*m_OwnedIoContext) + { + ParseUrl(Url); + } + + Impl(std::string_view Url, IWsClientHandler& Handler, asio::io_context& IoContext, const HttpWsClientSettings& Settings) + : m_Handler(Handler) + , m_Settings(Settings) + , m_Log(logging::Get(Settings.LogCategory)) + , m_IoContext(IoContext) + { + ParseUrl(Url); + } + + ~Impl() + { + // Release work guard so io_context::run() can return + m_WorkGuard.reset(); + + // Close the socket to cancel pending async ops + if (m_Socket) + { + asio::error_code Ec; + m_Socket->close(Ec); + } + + if (m_IoThread.joinable()) + { + m_IoThread.join(); + } + } + + void ParseUrl(std::string_view Url) + { + // Expected format: ws://host:port/path + if (Url.substr(0, 5) == "ws://") + { + Url.remove_prefix(5); + } + + auto SlashPos = Url.find('/'); + std::string_view HostPort; + if (SlashPos != std::string_view::npos) + { + HostPort = Url.substr(0, SlashPos); + m_Path = std::string(Url.substr(SlashPos)); + } + else + { + HostPort = Url; + m_Path = "/"; + } + + auto ColonPos = HostPort.find(':'); + if (ColonPos != std::string_view::npos) + { + m_Host = std::string(HostPort.substr(0, ColonPos)); + m_Port = std::string(HostPort.substr(ColonPos + 1)); + } + else + { + m_Host = std::string(HostPort); + m_Port = "80"; + } + } + + void Connect() + { + if (m_OwnedIoContext) + { + m_WorkGuard = std::make_unique(m_IoContext); + m_IoThread = std::thread([this] { m_IoContext.run(); }); + } + + asio::post(m_IoContext, [this] { DoResolve(); }); + } + + void DoResolve() + { + m_Resolver = std::make_unique(m_IoContext); + + m_Resolver->async_resolve(m_Host, m_Port, [this](const asio::error_code& Ec, asio::ip::tcp::resolver::results_type Results) { + if (Ec) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket resolve failed for {}:{}: {}", m_Host, m_Port, Ec.message()); + m_Handler.OnWsClose(1006, "resolve failed"); + return; + } + + DoConnect(Results); + }); + } + + void DoConnect(const asio::ip::tcp::resolver::results_type& Endpoints) + { + m_Socket = std::make_unique(m_IoContext); + + // Start connect timeout timer + m_Timer = std::make_unique(m_IoContext, m_Settings.ConnectTimeout); + m_Timer->async_wait([this](const asio::error_code& Ec) { + if (!Ec && !m_IsOpen.load(std::memory_order_relaxed)) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket connect timeout for {}:{}", m_Host, m_Port); + if (m_Socket) + { + asio::error_code CloseEc; + m_Socket->close(CloseEc); + } + } + }); + + asio::async_connect(*m_Socket, Endpoints, [this](const asio::error_code& Ec, const asio::ip::tcp::endpoint&) { + if (Ec) + { + m_Timer->cancel(); + ZEN_LOG_DEBUG(m_Log, "WebSocket connect failed for {}:{}: {}", m_Host, m_Port, Ec.message()); + m_Handler.OnWsClose(1006, "connect failed"); + return; + } + + DoHandshake(); + }); + } + + void DoHandshake() + { + // Generate random Sec-WebSocket-Key (16 random bytes, base64 encoded) + uint8_t KeyBytes[16]; + { + static thread_local std::mt19937 s_Rng(std::random_device{}()); + for (int i = 0; i < 4; ++i) + { + uint32_t Val = s_Rng(); + std::memcpy(KeyBytes + i * 4, &Val, 4); + } + } + + char KeyBase64[Base64::GetEncodedDataSize(16) + 1]; + uint32_t KeyLen = Base64::Encode(KeyBytes, 16, KeyBase64); + KeyBase64[KeyLen] = '\0'; + m_WebSocketKey = std::string(KeyBase64, KeyLen); + + // Build the HTTP upgrade request + ExtendableStringBuilder<512> Request; + Request << "GET " << m_Path << " HTTP/1.1\r\n" + << "Host: " << m_Host << ":" << m_Port << "\r\n" + << "Upgrade: websocket\r\n" + << "Connection: Upgrade\r\n" + << "Sec-WebSocket-Key: " << m_WebSocketKey << "\r\n" + << "Sec-WebSocket-Version: 13\r\n"; + + // Add Authorization header if access token provider is set + if (m_Settings.AccessTokenProvider) + { + HttpClientAccessToken Token = (*m_Settings.AccessTokenProvider)(); + if (Token.IsValid()) + { + Request << "Authorization: Bearer " << Token.Value << "\r\n"; + } + } + + Request << "\r\n"; + + std::string_view ReqStr = Request.ToView(); + + m_HandshakeBuffer = std::make_shared(ReqStr); + + asio::async_write(*m_Socket, + asio::buffer(m_HandshakeBuffer->data(), m_HandshakeBuffer->size()), + [this](const asio::error_code& Ec, std::size_t) { + if (Ec) + { + m_Timer->cancel(); + ZEN_LOG_DEBUG(m_Log, "WebSocket handshake write failed: {}", Ec.message()); + m_Handler.OnWsClose(1006, "handshake write failed"); + return; + } + + DoReadHandshakeResponse(); + }); + } + + void DoReadHandshakeResponse() + { + asio::async_read_until(*m_Socket, m_ReadBuffer, "\r\n\r\n", [this](const asio::error_code& Ec, std::size_t) { + m_Timer->cancel(); + + if (Ec) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket handshake read failed: {}", Ec.message()); + m_Handler.OnWsClose(1006, "handshake read failed"); + return; + } + + // Parse the response + const auto& Data = m_ReadBuffer.data(); + std::string Response(asio::buffers_begin(Data), asio::buffers_end(Data)); + + // Consume the headers from the read buffer (any extra data stays for frame parsing) + auto HeaderEnd = Response.find("\r\n\r\n"); + if (HeaderEnd != std::string::npos) + { + m_ReadBuffer.consume(HeaderEnd + 4); + } + + // Validate 101 response + if (Response.find("101") == std::string::npos) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket handshake rejected (no 101): {}", Response.substr(0, 80)); + m_Handler.OnWsClose(1006, "handshake rejected"); + return; + } + + // Validate Sec-WebSocket-Accept + std::string ExpectedAccept = WsFrameCodec::ComputeAcceptKey(m_WebSocketKey); + if (Response.find(ExpectedAccept) == std::string::npos) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket handshake: invalid Sec-WebSocket-Accept"); + m_Handler.OnWsClose(1006, "invalid accept key"); + return; + } + + m_IsOpen.store(true); + m_Handler.OnWsOpen(); + EnqueueRead(); + }); + } + + ////////////////////////////////////////////////////////////////////////// + // + // Read loop + // + + void EnqueueRead() + { + if (!m_IsOpen.load(std::memory_order_relaxed)) + { + return; + } + + asio::async_read(*m_Socket, m_ReadBuffer, asio::transfer_at_least(1), [this](const asio::error_code& Ec, std::size_t) { + OnDataReceived(Ec); + }); + } + + void OnDataReceived(const asio::error_code& Ec) + { + if (Ec) + { + if (Ec != asio::error::eof && Ec != asio::error::operation_aborted) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket read error: {}", Ec.message()); + } + + if (m_IsOpen.exchange(false)) + { + m_Handler.OnWsClose(1006, "connection lost"); + } + return; + } + + ProcessReceivedData(); + + if (m_IsOpen.load(std::memory_order_relaxed)) + { + EnqueueRead(); + } + } + + void ProcessReceivedData() + { + while (m_ReadBuffer.size() > 0) + { + const auto& InputBuffer = m_ReadBuffer.data(); + const auto* RawData = static_cast(InputBuffer.data()); + const auto Size = InputBuffer.size(); + + WsFrameParseResult Frame = WsFrameCodec::TryParseFrame(RawData, Size); + if (!Frame.IsValid) + { + break; + } + + m_ReadBuffer.consume(Frame.BytesConsumed); + + switch (Frame.Opcode) + { + case WebSocketOpcode::kText: + case WebSocketOpcode::kBinary: + { + WebSocketMessage Msg; + Msg.Opcode = Frame.Opcode; + Msg.Payload = IoBuffer(IoBuffer::Clone, Frame.Payload.data(), Frame.Payload.size()); + m_Handler.OnWsMessage(Msg); + break; + } + + case WebSocketOpcode::kPing: + { + // Auto-respond with masked pong + std::vector PongFrame = WsFrameCodec::BuildMaskedFrame(WebSocketOpcode::kPong, Frame.Payload); + EnqueueWrite(std::move(PongFrame)); + break; + } + + case WebSocketOpcode::kPong: + break; + + case WebSocketOpcode::kClose: + { + uint16_t Code = 1000; + std::string_view Reason; + + if (Frame.Payload.size() >= 2) + { + Code = (uint16_t(Frame.Payload[0]) << 8) | uint16_t(Frame.Payload[1]); + if (Frame.Payload.size() > 2) + { + Reason = + std::string_view(reinterpret_cast(Frame.Payload.data() + 2), Frame.Payload.size() - 2); + } + } + + // Echo masked close frame if we haven't sent one yet + if (!m_CloseSent) + { + m_CloseSent = true; + std::vector CloseFrame = WsFrameCodec::BuildMaskedCloseFrame(Code); + EnqueueWrite(std::move(CloseFrame)); + } + + m_IsOpen.store(false); + m_Handler.OnWsClose(Code, Reason); + return; + } + + default: + ZEN_LOG_WARN(m_Log, "Unknown WebSocket opcode: {:#x}", static_cast(Frame.Opcode)); + break; + } + } + } + + ////////////////////////////////////////////////////////////////////////// + // + // Write queue + // + + void EnqueueWrite(std::vector Frame) + { + bool ShouldFlush = false; + + m_WriteLock.WithExclusiveLock([&] { + m_WriteQueue.push_back(std::move(Frame)); + if (!m_IsWriting) + { + m_IsWriting = true; + ShouldFlush = true; + } + }); + + if (ShouldFlush) + { + FlushWriteQueue(); + } + } + + void FlushWriteQueue() + { + std::vector Frame; + + m_WriteLock.WithExclusiveLock([&] { + if (m_WriteQueue.empty()) + { + m_IsWriting = false; + return; + } + Frame = std::move(m_WriteQueue.front()); + m_WriteQueue.pop_front(); + }); + + if (Frame.empty()) + { + return; + } + + auto OwnedFrame = std::make_shared>(std::move(Frame)); + + asio::async_write(*m_Socket, + asio::buffer(OwnedFrame->data(), OwnedFrame->size()), + [this, OwnedFrame](const asio::error_code& Ec, std::size_t) { OnWriteComplete(Ec); }); + } + + void OnWriteComplete(const asio::error_code& Ec) + { + if (Ec) + { + if (Ec != asio::error::operation_aborted) + { + ZEN_LOG_DEBUG(m_Log, "WebSocket write error: {}", Ec.message()); + } + + m_WriteLock.WithExclusiveLock([&] { + m_IsWriting = false; + m_WriteQueue.clear(); + }); + + if (m_IsOpen.exchange(false)) + { + m_Handler.OnWsClose(1006, "write error"); + } + return; + } + + FlushWriteQueue(); + } + + ////////////////////////////////////////////////////////////////////////// + // + // Public operations + // + + void SendText(std::string_view Text) + { + if (!m_IsOpen.load(std::memory_order_relaxed)) + { + return; + } + + std::span Payload(reinterpret_cast(Text.data()), Text.size()); + std::vector Frame = WsFrameCodec::BuildMaskedFrame(WebSocketOpcode::kText, Payload); + EnqueueWrite(std::move(Frame)); + } + + void SendBinary(std::span Data) + { + if (!m_IsOpen.load(std::memory_order_relaxed)) + { + return; + } + + std::vector Frame = WsFrameCodec::BuildMaskedFrame(WebSocketOpcode::kBinary, Data); + EnqueueWrite(std::move(Frame)); + } + + void DoClose(uint16_t Code, std::string_view Reason) + { + if (!m_IsOpen.exchange(false)) + { + return; + } + + if (!m_CloseSent) + { + m_CloseSent = true; + std::vector CloseFrame = WsFrameCodec::BuildMaskedCloseFrame(Code, Reason); + EnqueueWrite(std::move(CloseFrame)); + } + } + + IWsClientHandler& m_Handler; + HttpWsClientSettings m_Settings; + LoggerRef m_Log; + + std::string m_Host; + std::string m_Port; + std::string m_Path; + + // io_context: owned (standalone) or external (shared) + std::unique_ptr m_OwnedIoContext; + asio::io_context& m_IoContext; + std::unique_ptr m_WorkGuard; + std::thread m_IoThread; + + // Connection state + std::unique_ptr m_Resolver; + std::unique_ptr m_Socket; + std::unique_ptr m_Timer; + asio::streambuf m_ReadBuffer; + std::string m_WebSocketKey; + std::shared_ptr m_HandshakeBuffer; + + // Write queue + RwLock m_WriteLock; + std::deque> m_WriteQueue; + bool m_IsWriting = false; + + std::atomic m_IsOpen{false}; + bool m_CloseSent = false; +}; + +////////////////////////////////////////////////////////////////////////// + +HttpWsClient::HttpWsClient(std::string_view Url, IWsClientHandler& Handler, const HttpWsClientSettings& Settings) +: m_Impl(std::make_unique(Url, Handler, Settings)) +{ +} + +HttpWsClient::HttpWsClient(std::string_view Url, + IWsClientHandler& Handler, + asio::io_context& IoContext, + const HttpWsClientSettings& Settings) +: m_Impl(std::make_unique(Url, Handler, IoContext, Settings)) +{ +} + +HttpWsClient::~HttpWsClient() = default; + +void +HttpWsClient::Connect() +{ + m_Impl->Connect(); +} + +void +HttpWsClient::SendText(std::string_view Text) +{ + m_Impl->SendText(Text); +} + +void +HttpWsClient::SendBinary(std::span Data) +{ + m_Impl->SendBinary(Data); +} + +void +HttpWsClient::Close(uint16_t Code, std::string_view Reason) +{ + m_Impl->DoClose(Code, Reason); +} + +bool +HttpWsClient::IsOpen() const +{ + return m_Impl->m_IsOpen.load(std::memory_order_relaxed); +} + +} // namespace zen -- cgit v1.2.3