// Copyright 2018 Espressif Systems (Shanghai) PTE LTD // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #ifndef _HTTPD_PRIV_H_ #define _HTTPD_PRIV_H_ #include #include #include #include #include #include #include #include "osal.h" #ifdef __cplusplus extern "C" { #endif /* Size of request data block/chunk (not to be confused with chunked encoded data) * that is received and parsed in one turn of the parsing process. This should not * exceed the scratch buffer size and should at least be 8 bytes */ #define PARSER_BLOCK_SIZE 128 /* Calculate the maximum size needed for the scratch buffer */ #define HTTPD_SCRATCH_BUF MAX(HTTPD_MAX_REQ_HDR_LEN, HTTPD_MAX_URI_LEN) /* Formats a log string to prepend context function name */ #define LOG_FMT(x) "%s: " x, __func__ /** * @brief Thread related data for internal use */ struct thread_data { othread_t handle; /*!< Handle to thread/task */ enum { THREAD_IDLE = 0, THREAD_RUNNING, THREAD_STOPPING, THREAD_STOPPED, } status; /*!< State of the thread */ }; /** * @brief A database of all the open sockets in the system. */ struct sock_db { int fd; /*!< The file descriptor for this socket */ void *ctx; /*!< A custom context for this socket */ bool ignore_sess_ctx_changes; /*!< Flag indicating if session context changes should be ignored */ void *transport_ctx; /*!< A custom 'transport' context for this socket, to be used by send/recv/pending */ httpd_handle_t handle; /*!< Server handle */ httpd_free_ctx_fn_t free_ctx; /*!< Function for freeing the context */ httpd_free_ctx_fn_t free_transport_ctx; /*!< Function for freeing the 'transport' context */ httpd_send_func_t send_fn; /*!< Send function for this socket */ httpd_recv_func_t recv_fn; /*!< Receive function for this socket */ httpd_pending_func_t pending_fn; /*!< Pending function for this socket */ uint64_t lru_counter; /*!< LRU Counter indicating when the socket was last used */ char pending_data[PARSER_BLOCK_SIZE]; /*!< Buffer for pending data to be received */ size_t pending_len; /*!< Length of pending data to be received */ }; /** * @brief Auxiliary data structure for use during reception and processing * of requests and temporarily keeping responses */ struct httpd_req_aux { struct sock_db *sd; /*!< Pointer to socket database */ char scratch[HTTPD_SCRATCH_BUF + 1]; /*!< Temporary buffer for our operations (1 byte extra for null termination) */ size_t remaining_len; /*!< Amount of data remaining to be fetched */ char *status; /*!< HTTP response's status code */ char *content_type; /*!< HTTP response's content type */ bool first_chunk_sent; /*!< Used to indicate if first chunk sent */ unsigned req_hdrs_count; /*!< Count of total headers in request packet */ unsigned resp_hdrs_count; /*!< Count of additional headers in response packet */ struct resp_hdr { const char *field; const char *value; } *resp_hdrs; /*!< Additional headers in response packet */ struct http_parser_url url_parse_res; /*!< URL parsing result, used for retrieving URL elements */ }; /** * @brief Server data for each instance. This is exposed publicly as * httpd_handle_t but internal structure/members are kept private. */ struct httpd_data { httpd_config_t config; /*!< HTTPD server configuration */ int listen_fd; /*!< Server listener FD */ int ctrl_fd; /*!< Ctrl message receiver FD */ int msg_fd; /*!< Ctrl message sender FD */ struct thread_data hd_td; /*!< Information for the HTTPD thread */ struct sock_db *hd_sd; /*!< The socket database */ httpd_uri_t **hd_calls; /*!< Registered URI handlers */ struct httpd_req hd_req; /*!< The current HTTPD request */ struct httpd_req_aux hd_req_aux; /*!< Additional data about the HTTPD request kept unexposed */ /* Array of registered error handler functions */ httpd_err_handler_func_t *err_handler_fns; }; /******************* Group : Session Management ********************/ /** @name Session Management * Functions related to HTTP session management * @{ */ /** * @brief Retrieve a session by its descriptor * * @param[in] hd Server instance data * @param[in] sockfd Socket FD * @return pointer into the socket DB, or NULL if not found */ struct sock_db *httpd_sess_get(struct httpd_data *hd, int sockfd); /** * @brief Delete sessions whose FDs have became invalid. * This is a recovery strategy e.g. after select() fails. * * @param[in] hd Server instance data */ void httpd_sess_delete_invalid(struct httpd_data *hd); /** * @brief Initializes an http session by resetting the sockets database. * * @param[in] hd Server instance data */ void httpd_sess_init(struct httpd_data *hd); /** * @brief Starts a new session for client requesting connection and adds * it's descriptor to the socket database. * * @param[in] hd Server instance data * @param[in] newfd Descriptor of the new client to be added to the session. * * @return * - ESP_OK : on successfully queuing the work * - ESP_FAIL : in case of control socket error while sending */ esp_err_t httpd_sess_new(struct httpd_data *hd, int newfd); /** * @brief Processes incoming HTTP requests * * @param[in] hd Server instance data * @param[in] clifd Descriptor of the client from which data is to be received * * @return * - ESP_OK : on successfully receiving, parsing and responding to a request * - ESP_FAIL : in case of failure in any of the stages of processing */ esp_err_t httpd_sess_process(struct httpd_data *hd, int clifd); /** * @brief Remove client descriptor from the session / socket database * and close the connection for this client. * * @note The returned descriptor should be used by httpd_sess_iterate() * to continue the iteration correctly. This ensures that the * iteration is not restarted abruptly which may cause reading from * a socket which has been already processed and thus blocking * the server loop until data appears on that socket. * * @param[in] hd Server instance data * @param[in] clifd Descriptor of the client to be removed from the session. * * @return * - +VE : Client descriptor preceding the one being deleted * - -1 : No descriptor preceding the one being deleted */ int httpd_sess_delete(struct httpd_data *hd, int clifd); /** * @brief Free session context * * @param[in] ctx Pointer to session context * @param[in] free_fn Free function to call on session context */ void httpd_sess_free_ctx(void *ctx, httpd_free_ctx_fn_t free_fn); /** * @brief Add descriptors present in the socket database to an fdset and * update the value of maxfd which are needed by the select function * for looking through all available sockets for incoming data. * * @param[in] hd Server instance data * @param[out] fdset File descriptor set to be updated. * @param[out] maxfd Maximum value among all file descriptors. */ void httpd_sess_set_descriptors(struct httpd_data *hd, fd_set *fdset, int *maxfd); /** * @brief Iterates through the list of client fds in the session /socket database. * Passing the value of a client fd returns the fd for the next client * in the database. In order to iterate from the beginning pass -1 as fd. * * @param[in] hd Server instance data * @param[in] fd Last accessed client descriptor. * -1 to reset iterator to start of database. * * @return * - +VE : Client descriptor next in the database * - -1 : End of iteration */ int httpd_sess_iterate(struct httpd_data *hd, int fd); /** * @brief Checks if session can accept another connection from new client. * If sockets database is full then this returns false. * * @param[in] hd Server instance data * * @return True if session can accept new clients */ bool httpd_is_sess_available(struct httpd_data *hd); /** * @brief Checks if session has any pending data/packets * for processing * * This is needed as httpd_unrecv may un-receive next * packet in the stream. If only partial packet was * received then select() would mark the fd for processing * as remaining part of the packet would still be in socket * recv queue. But if a complete packet got unreceived * then it would not be processed until further data is * received on the socket. This is when this function * comes in use, as it checks the socket's pending data * buffer. * * @param[in] hd Server instance data * @param[in] fd Client descriptor * * @return True if there is any pending data */ bool httpd_sess_pending(struct httpd_data *hd, int fd); /** * @brief Removes the least recently used client from the session * * This may be useful if new clients are requesting for connection but * max number of connections is reached, in which case the client which * is inactive for the longest will be removed from the session. * * @param[in] hd Server instance data * * @return * - ESP_OK : if session closure initiated successfully * - ESP_FAIL : if failed */ esp_err_t httpd_sess_close_lru(struct httpd_data *hd); /** End of Group : Session Management * @} */ /****************** Group : URI Handling ********************/ /** @name URI Handling * Methods for accessing URI handlers * @{ */ /** * @brief For an HTTP request, searches through all the registered URI handlers * and invokes the appropriate one if found * * @param[in] hd Server instance data for which handler needs to be invoked * * @return * - ESP_OK : if handler found and executed successfully * - ESP_FAIL : otherwise */ esp_err_t httpd_uri(struct httpd_data *hd); /** * @brief Unregister all URI handlers * * @param[in] hd Server instance data */ void httpd_unregister_all_uri_handlers(struct httpd_data *hd); /** * @brief Validates the request to prevent users from calling APIs, that are to * be called only inside a URI handler, outside the handler context * * @param[in] req Pointer to HTTP request that needs to be validated * * @return * - true : if valid request * - false : otherwise */ bool httpd_validate_req_ptr(httpd_req_t *r); /* httpd_validate_req_ptr() adds some overhead to frequently used APIs, * and is useful mostly for debugging, so it's preferable to disable * the check by default and enable it only if necessary */ #ifdef CONFIG_HTTPD_VALIDATE_REQ #define httpd_valid_req(r) httpd_validate_req_ptr(r) #else #define httpd_valid_req(r) true #endif /** End of Group : URI Handling * @} */ /****************** Group : Processing ********************/ /** @name Processing * Methods for processing HTTP requests * @{ */ /** * @brief Initiates the processing of HTTP request * * Receives incoming TCP packet on a socket, then parses the packet as * HTTP request and fills httpd_req_t data structure with the extracted * URI, headers are ready to be fetched from scratch buffer and calling * http_recv() after this reads the body of the request. * * @param[in] hd Server instance data * @param[in] sd Pointer to socket which is needed for receiving TCP packets. * * @return * - ESP_OK : if request packet is valid * - ESP_FAIL : otherwise */ esp_err_t httpd_req_new(struct httpd_data *hd, struct sock_db *sd); /** * @brief For an HTTP request, resets the resources allocated for it and * purges any data left to be received * * @param[in] hd Server instance data * * @return * - ESP_OK : if request packet deleted and resources cleaned. * - ESP_FAIL : otherwise. */ esp_err_t httpd_req_delete(struct httpd_data *hd); /** * @brief For handling HTTP errors by invoking registered * error handler function * * @param[in] req Pointer to the HTTP request for which error occurred * @param[in] error Error type * * @return * - ESP_OK : error handled successful * - ESP_FAIL : failure indicates that the underlying socket needs to be closed */ esp_err_t httpd_req_handle_err(httpd_req_t *req, httpd_err_code_t error); /** End of Group : Parsing * @} */ /****************** Group : Send/Receive ********************/ /** @name Send and Receive * Methods for transmitting and receiving HTTP requests and responses * @{ */ /** * @brief For sending out data in response to an HTTP request. * * @param[in] req Pointer to the HTTP request for which the response needs to be sent * @param[in] buf Pointer to the buffer from where the body of the response is taken * @param[in] buf_len Length of the buffer * * @return * - Length of data : if successful * - ESP_FAIL : if failed */ int httpd_send(httpd_req_t *req, const char *buf, size_t buf_len); /** * @brief For receiving HTTP request data * * @note The exposed API httpd_recv() is simply this function with last parameter * set as false. This function is used internally during reception and * processing of a new request. The option to halt after receiving pending * data prevents the server from requesting more data than is needed for * completing a packet in case when all the remaining part of the packet is * in the pending buffer. * * @param[in] req Pointer to new HTTP request which only has the socket descriptor * @param[out] buf Pointer to the buffer which will be filled with the received data * @param[in] buf_len Length of the buffer * @param[in] halt_after_pending When set true, halts immediately after receiving from * pending buffer * * @return * - Length of data : if successful * - ESP_FAIL : if failed */ int httpd_recv_with_opt(httpd_req_t *r, char *buf, size_t buf_len, bool halt_after_pending); /** * @brief For un-receiving HTTP request data * * This function copies data into internal buffer pending_data so that * when httpd_recv is called, it first fetches this pending data and * then only starts receiving from the socket * * @note If data is too large for the internal buffer then only * part of the data is unreceived, reflected in the returned * length. Make sure that such truncation is checked for and * handled properly. * * @param[in] req Pointer to new HTTP request which only has the socket descriptor * @param[in] buf Pointer to the buffer from where data needs to be un-received * @param[in] buf_len Length of the buffer * * @return Length of data copied into pending buffer */ size_t httpd_unrecv(struct httpd_req *r, const char *buf, size_t buf_len); /** * @brief This is the low level default send function of the HTTPD. This should * NEVER be called directly. The semantics of this is exactly similar to * send() of the BSD socket API. * * @param[in] hd Server instance data * @param[in] sockfd Socket descriptor for sending data * @param[in] buf Pointer to the buffer from where the body of the response is taken * @param[in] buf_len Length of the buffer * @param[in] flags Flags for mode selection * * @return * - Length of data : if successful * - -1 : if failed (appropriate errno is set) */ int httpd_default_send(httpd_handle_t hd, int sockfd, const char *buf, size_t buf_len, int flags); /** * @brief This is the low level default recv function of the HTTPD. This should * NEVER be called directly. The semantics of this is exactly similar to * recv() of the BSD socket API. * * @param[in] hd Server instance data * @param[in] sockfd Socket descriptor for sending data * @param[out] buf Pointer to the buffer which will be filled with the received data * @param[in] buf_len Length of the buffer * @param[in] flags Flags for mode selection * * @return * - Length of data : if successful * - -1 : if failed (appropriate errno is set) */ int httpd_default_recv(httpd_handle_t hd, int sockfd, char *buf, size_t buf_len, int flags); /** End of Group : Send and Receive * @} */ #ifdef __cplusplus } #endif #endif /* ! _HTTPD_PRIV_H_ */