feat: add body check callback

user can set callback,check request and early response.

include/cinatra/connection.hpp

@@ -36,15 +36,19 @@ class connection : public base_connection,
       asio::io_service &io_service, ssl_configure ssl_conf,
       std::size_t max_req_size, long keep_alive_timeout, http_handler &handler,
       std::string &static_dir,
-      std::function<bool(request &req, response &res)> *upload_check)
+      std::function<bool(request &req, response &res)> *upload_check,
+      std::string &checker_resp,
+      std::function<bool(request &req, response &res)> *req_body_check)
       : socket_(io_service),
         MAX_REQ_SIZE_(max_req_size),
         KEEP_ALIVE_TIMEOUT_(keep_alive_timeout),
         timer_(io_service),
         http_handler_(handler),
         req_(res_),
         static_dir_(static_dir),
-        upload_check_(upload_check) {
+        upload_check_(upload_check),
+        checker_resp_(checker_resp),
+        req_body_check_(req_body_check) {
     if constexpr (is_ssl_) {
       init_ssl_context(std::move(ssl_conf));
     }
@@ -408,12 +412,6 @@ class connection : public base_connection,
       return;
     }
 
-    size_t body_len = req_.body_len();
-    if (body_len > max_body_len_) {
-      response_back();
-      return;
-    }
-
     int ret = req_.parse_header(len_);
 
     if (ret == parse_status::has_error) {
@@ -448,7 +446,16 @@ class connection : public base_connection,
   void handle_request(std::size_t bytes_transferred) {
     auto type = get_content_type();
     req_.set_http_type(type);
+
     if (req_.has_body()) {
+      if (req_body_check_) {
+        bool r = (*req_body_check_)(req_, res_);
+        if (!r) {
+          response_back(status_type::entity_too_large,
+                        std::move(checker_resp_));
+          return;
+        }
+      }
       switch (type) {
         case cinatra::content_type::string:
         case cinatra::content_type::websocket:
@@ -1476,6 +1483,8 @@ class connection : public base_connection,
   // callback handler to application layer
   const http_handler &http_handler_;
   std::function<bool(request &req, response &res)> *upload_check_ = nullptr;
+  std::string checker_resp_;
+  std::function<bool(request &req, response &res)> *req_body_check_ = nullptr;
   std::any tag_;
   std::function<void(request &, std::string &)> multipart_begin_ = nullptr;
 

include/cinatra/http_server.hpp

@@ -245,6 +245,13 @@ class http_server_ : private noncopyable {
     upload_check_ = std::move(checker);
   }
 
+  // should be called before listen
+  void set_body_check(std::function<bool(request &req, response &res)> checker,
+                      std::string resp_str = "") {
+    checker_resp_ = resp_str;
+    req_body_check_ = std::move(checker);
+  }
+
   void mapping_to_root_path(std::string relate_path) {
     relate_paths_.emplace_back("." + std::move(relate_path));
   }
@@ -280,7 +287,8 @@ class http_server_ : private noncopyable {
     auto new_conn = std::make_shared<connection<ScoketType>>(
         io_service_pool_.get_io_service(), ssl_conf_, max_req_buf_size_,
         keep_alive_timeout_, http_handler_, upload_dir_,
-        upload_check_ ? &upload_check_ : nullptr);
+        upload_check_ ? &upload_check_ : nullptr, checker_resp_,
+        req_body_check_ ? &req_body_check_ : nullptr);
 
     acceptor_->async_accept(
         new_conn->tcp_socket(), [this, new_conn](const std::error_code &e) {
@@ -603,6 +611,8 @@ class http_server_ : private noncopyable {
   std::function<bool(request &req, response &res)> download_check_;
   std::vector<std::string> relate_paths_;
   std::function<bool(request &req, response &res)> upload_check_ = nullptr;
+  std::string checker_resp_;
+  std::function<bool(request &req, response &res)> req_body_check_ = nullptr;
 
   std::function<void(request &req, response &res)> not_found_ = nullptr;
   std::function<void(request &, std::string &)> multipart_begin_ = nullptr;