fix(libhttp): WebSocket 单条消息大小限制防 OOM (P1-3)

- 新增 setMaxWsMessageSize/getMaxWsMessageSize（默认 16MB，与 Beast 默认一致）
- 服务端 doWsUpgrade/doWssUpgrade 与代理流 onProxyConnect/onProxySslHandshake 创建后调用 read_message_max
- 超限消息由 Beast 在分配内存前拒绝并关闭连接
- 更新审计文档 P1-3 状态、README v3.4.1

libhttp/README.md

@@ -13,6 +13,7 @@ C++20 network library for the UniServe microservice framework, providing unified
 - **Static Files**: `setStaticDirectory()` for serving static files
 - **Thread Pool**: Multi-threaded I/O with `asio::strand` for thread safety
 - **Client Management**: WebSocket client tracking, broadcast, and targeted send
+- **WS Message Size Limit**: `setMaxWsMessageSize()` caps single WebSocket message (default 16MB, aligned with Beast; applies to server and proxy streams) to prevent OOM
 
 ### HttpClient
 - **HTTP Client**: Synchronous HTTP requests via libcurl (GET/POST/PUT/DELETE/PATCH/HEAD/OPTIONS)
@@ -167,6 +168,10 @@ void use(MiddlewareHandler middleware);
 void setStaticDirectory(const std::string& path);
 ```
 
+// WebSocket 单条消息大小上限（字节）。默认 16MB，与 Beast 默认一致；超限由 Beast 拒绝并关闭连接（防 OOM）。
+void setMaxWsMessageSize(std::size_t bytes);
+std::size_t getMaxWsMessageSize() const;
+
 **WebSocket Routes**
 ```cpp
 void ws(const std::string& path, WebSocketMessageHandler handler);
@@ -283,6 +288,7 @@ using WebSocketClientBase = HttpClient;
 
 ## Version History
 
+- **v3.4.1**: WebSocket 单条消息大小限制（P1-3）。新增 `setMaxWsMessageSize()`/`getMaxWsMessageSize()`（默认 16MB，与 Beast 默认一致），服务端 `doWsUpgrade`/`doWssUpgrade` 与代理 `onProxyConnect`/`onProxySslHandshake` 创建流后调用 `read_message_max()`，超限消息由 Beast 在分配内存前拒绝并关闭连接，防 OOM。
 - **v3.4.0**: HttpClient 响应大小限制（防 OOM）。`request_stream_sync` 改为真流式（按块回调，不二次缓冲）；新增 `set_max_response_size()`/`get_max_response_size()`（默认 10MB，对齐 WAF，0 表示不限制），超限时 `write_callback` 返回 0 中止传输并抛异常。
 - **v3.3.0**: Split HttpServer into 6 modular translation units by functional area (core/lifecycle, listener, routes, request dispatch, WS management, WS session/proxy) for dramatically faster incremental builds. Added internal detail header `inc/us/detail/HttpServerImpl.hpp` for shared definitions across TU boundaries.
 - **v3.2.0**: Split into two shared libraries — `libus_http.so` (server only, no curl) and `libus_httpclient.so` (HttpClient, depends on curl). HttpClient implementation moved to `src/HttpClient.cpp`; `HttpClient.hpp` is declaration-only.

libhttp/inc/us/HttpServer.hpp

@@ -119,6 +119,11 @@ public:
     void setMaxBodySize(std::size_t bytes) { max_body_size_ = bytes; }
     std::size_t getMaxBodySize() const { return max_body_size_; }
 
+    // WebSocket 单条消息大小上限（字节）。默认 16MB，与 Beast 默认一致（防 OOM）。
+    // 超限时 Beast 拒绝该消息并关闭连接（P1-3）。
+    void setMaxWsMessageSize(std::size_t bytes) { max_ws_message_size_ = bytes; }
+    std::size_t getMaxWsMessageSize() const { return max_ws_message_size_; }
+
     class debug {
     public:
         static void print_all_header_fields(const http::request<http::string_body>& req);
@@ -134,6 +139,7 @@ private:
     std::atomic<bool> running_{false};
 
     std::size_t max_body_size_ = 10 * 1024 * 1024; // 默认 10MB,与 WAF 对齐
+    std::size_t max_ws_message_size_ = 16 * 1024 * 1024; // 默认 16MB,与 Beast 默认一致
 
     bool ssl_enabled_{false};
     std::string cert_file_;

libhttp/src/HttpServer_WsSession.cpp

@@ -19,6 +19,8 @@ void HttpServer::Session::doWsUpgrade() {
     auto self = shared_from_this();
     ws_stream_ = std::make_unique<ws_stream>(stream_);
     ws_stream_->text(true);
+    // P1-3：限制单条 WS 消息大小，超限由 Beast 拒绝并关闭连接（防 OOM）
+    ws_stream_->read_message_max(server_->getMaxWsMessageSize());
 
     ws_stream_->async_accept(
         request_,
@@ -31,6 +33,8 @@ void HttpServer::Session::doWssUpgrade() {
     auto self = shared_from_this();
     wss_stream_ = std::make_unique<wss_stream>(*ssl_stream_);
     wss_stream_->text(true);
+    // P1-3：限制单条 WS 消息大小，超限由 Beast 拒绝并关闭连接（防 OOM）
+    wss_stream_->read_message_max(server_->getMaxWsMessageSize());
 
     wss_stream_->async_accept(
         request_,
@@ -261,6 +265,9 @@ void HttpServer::Session::onProxyConnect(beast::error_code ec, tcp::endpoint /*e
         proxy_ws_stream_ = std::make_unique<proxy_ws_stream>(proxy_tcp_stream_->socket());
         proxy_tcp_stream_->expires_never();
 
+        // P1-3：限制代理方向单条 WS 消息大小（防 OOM）
+        proxy_ws_stream_->read_message_max(server_->getMaxWsMessageSize());
+
         proxy_ws_stream_->set_option(websocket::stream_base::decorator(
             [](websocket::request_type& req) {
                 req.set(http::field::user_agent, "UniServe-WsProxy");
@@ -286,6 +293,9 @@ void HttpServer::Session::onProxySslHandshake(beast::error_code ec) {
     proxy_wss_stream_ = std::make_unique<proxy_wss_stream>(*proxy_ssl_stream_);
     proxy_tcp_stream_->expires_never();
 
+    // P1-3：限制代理方向单条 WS 消息大小（防 OOM）
+    proxy_wss_stream_->read_message_max(server_->getMaxWsMessageSize());
+
     proxy_wss_stream_->set_option(websocket::stream_base::decorator(
         [](websocket::request_type& req) {
             req.set(http::field::user_agent, "UniServe-WsProxy");