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/servers/wsframecodec.h | 74 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 src/zenhttp/servers/wsframecodec.h (limited to 'src/zenhttp/servers/wsframecodec.h') diff --git a/src/zenhttp/servers/wsframecodec.h b/src/zenhttp/servers/wsframecodec.h new file mode 100644 index 000000000..2d90b6fa1 --- /dev/null +++ b/src/zenhttp/servers/wsframecodec.h @@ -0,0 +1,74 @@ +// Copyright Epic Games, Inc. All Rights Reserved. + +#pragma once + +#include + +#include +#include +#include +#include +#include +#include +#include + +namespace zen { + +/** + * Result of attempting to parse a single WebSocket frame from a byte buffer + */ +struct WsFrameParseResult +{ + bool IsValid = false; // true if a complete frame was successfully parsed + size_t BytesConsumed = 0; // number of bytes consumed from the input buffer + WebSocketOpcode Opcode = WebSocketOpcode::kText; + bool Fin = false; + std::vector Payload; +}; + +/** + * RFC 6455 WebSocket frame codec + * + * Provides static helpers for parsing client-to-server frames (which are + * always masked) and building server-to-client frames (which are never masked). + */ +struct WsFrameCodec +{ + /** + * Try to parse one complete frame from the front of the buffer. + * + * Returns a result with IsValid == false and BytesConsumed == 0 when + * there is not enough data yet. The caller should accumulate more data + * and retry. + */ + static WsFrameParseResult TryParseFrame(const uint8_t* Data, size_t Size); + + /** + * Build a server-to-client frame (no masking) + */ + static std::vector BuildFrame(WebSocketOpcode Opcode, std::span Payload); + + /** + * Build a close frame with a status code and optional reason string + */ + static std::vector BuildCloseFrame(uint16_t Code, std::string_view Reason = {}); + + /** + * Build a client-to-server frame (with masking per RFC 6455) + */ + static std::vector BuildMaskedFrame(WebSocketOpcode Opcode, std::span Payload); + + /** + * Build a masked close frame with status code and optional reason + */ + static std::vector BuildMaskedCloseFrame(uint16_t Code, std::string_view Reason = {}); + + /** + * Compute the Sec-WebSocket-Accept value per RFC 6455 section 4.2.2 + * + * accept = Base64(SHA1(clientKey + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")) + */ + static std::string ComputeAcceptKey(std::string_view ClientKey); +}; + +} // namespace zen -- cgit v1.2.3