esp-idf/components/esp_http_server/include/esp_http_server.h
Chip Weinberger 3824eba04d
feat(httpd): add support for asynchronous request handling
This commit adds support for handling multiple requests simultaneously by introducing two new functions: `httpd_req_async_handler_begin()` and `httpd_req_async_handler_complete()`. These functions allow creating an asynchronous copy of a request that can be used on a separate thread and marking the asynchronous request as completed, respectively.

Additionally, a new flag `for_async_req` has been added to the `httpd_sess_t` struct to indicate if a socket is being used for an asynchronous request and should not be purged from the LRU cache.

An example have been added to demonstrate the usage of these new functions.

Closes https://github.com/espressif/esp-idf/issues/10594

Signed-off-by: Harshit Malpani <harshit.malpani@espressif.com>
2023-05-19 10:05:42 +05:30

1786 lines
69 KiB
C

/*
* SPDX-FileCopyrightText: 2018-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef _ESP_HTTP_SERVER_H_
#define _ESP_HTTP_SERVER_H_
#include <stdio.h>
#include <string.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <http_parser.h>
#include <sdkconfig.h>
#include <esp_err.h>
#include <esp_event.h>
#include <esp_event_base.h>
#ifdef __cplusplus
extern "C" {
#endif
#define ESP_HTTPD_DEF_CTRL_PORT (32768) /*!< HTTP Server control socket port*/
ESP_EVENT_DECLARE_BASE(ESP_HTTP_SERVER_EVENT);
/**
* @brief HTTP Server events id
*/
typedef enum {
HTTP_SERVER_EVENT_ERROR = 0, /*!< This event occurs when there are any errors during execution */
HTTP_SERVER_EVENT_START, /*!< This event occurs when HTTP Server is started */
HTTP_SERVER_EVENT_ON_CONNECTED, /*!< Once the HTTP Server has been connected to the client, no data exchange has been performed */
HTTP_SERVER_EVENT_ON_HEADER, /*!< Occurs when receiving each header sent from the client */
HTTP_SERVER_EVENT_HEADERS_SENT, /*!< After sending all the headers to the client */
HTTP_SERVER_EVENT_ON_DATA, /*!< Occurs when receiving data from the client */
HTTP_SERVER_EVENT_SENT_DATA, /*!< Occurs when an ESP HTTP server session is finished */
HTTP_SERVER_EVENT_DISCONNECTED, /*!< The connection has been disconnected */
HTTP_SERVER_EVENT_STOP, /*!< This event occurs when HTTP Server is stopped */
} esp_http_server_event_id_t;
/** Argument structure for HTTP_SERVER_EVENT_ON_DATA and HTTP_SERVER_EVENT_SENT_DATA event */
typedef struct {
int fd; /*!< Session socket file descriptor */
int data_len; /*!< Data length */
} esp_http_server_event_data;
/*
note: esp_https_server.h includes a customized copy of this
initializer that should be kept in sync
*/
#define HTTPD_DEFAULT_CONFIG() { \
.task_priority = tskIDLE_PRIORITY+5, \
.stack_size = 4096, \
.core_id = tskNO_AFFINITY, \
.server_port = 80, \
.ctrl_port = ESP_HTTPD_DEF_CTRL_PORT, \
.max_open_sockets = 7, \
.max_uri_handlers = 8, \
.max_resp_headers = 8, \
.backlog_conn = 5, \
.lru_purge_enable = false, \
.recv_wait_timeout = 5, \
.send_wait_timeout = 5, \
.global_user_ctx = NULL, \
.global_user_ctx_free_fn = NULL, \
.global_transport_ctx = NULL, \
.global_transport_ctx_free_fn = NULL, \
.enable_so_linger = false, \
.linger_timeout = 0, \
.keep_alive_enable = false, \
.keep_alive_idle = 0, \
.keep_alive_interval = 0, \
.keep_alive_count = 0, \
.open_fn = NULL, \
.close_fn = NULL, \
.uri_match_fn = NULL \
}
#define ESP_ERR_HTTPD_BASE (0xb000) /*!< Starting number of HTTPD error codes */
#define ESP_ERR_HTTPD_HANDLERS_FULL (ESP_ERR_HTTPD_BASE + 1) /*!< All slots for registering URI handlers have been consumed */
#define ESP_ERR_HTTPD_HANDLER_EXISTS (ESP_ERR_HTTPD_BASE + 2) /*!< URI handler with same method and target URI already registered */
#define ESP_ERR_HTTPD_INVALID_REQ (ESP_ERR_HTTPD_BASE + 3) /*!< Invalid request pointer */
#define ESP_ERR_HTTPD_RESULT_TRUNC (ESP_ERR_HTTPD_BASE + 4) /*!< Result string truncated */
#define ESP_ERR_HTTPD_RESP_HDR (ESP_ERR_HTTPD_BASE + 5) /*!< Response header field larger than supported */
#define ESP_ERR_HTTPD_RESP_SEND (ESP_ERR_HTTPD_BASE + 6) /*!< Error occured while sending response packet */
#define ESP_ERR_HTTPD_ALLOC_MEM (ESP_ERR_HTTPD_BASE + 7) /*!< Failed to dynamically allocate memory for resource */
#define ESP_ERR_HTTPD_TASK (ESP_ERR_HTTPD_BASE + 8) /*!< Failed to launch server task/thread */
/* Symbol to be used as length parameter in httpd_resp_send APIs
* for setting buffer length to string length */
#define HTTPD_RESP_USE_STRLEN -1
/* ************** Group: Initialization ************** */
/** @name Initialization
* APIs related to the Initialization of the web server
* @{
*/
/**
* @brief HTTP Server Instance Handle
*
* Every instance of the server will have a unique handle.
*/
typedef void* httpd_handle_t;
/**
* @brief HTTP Method Type wrapper over "enum http_method"
* available in "http_parser" library
*/
typedef enum http_method httpd_method_t;
/**
* @brief Prototype for freeing context data (if any)
* @param[in] ctx object to free
*/
typedef void (*httpd_free_ctx_fn_t)(void *ctx);
/**
* @brief Function prototype for opening a session.
*
* Called immediately after the socket was opened to set up the send/recv functions and
* other parameters of the socket.
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
* @return
* - ESP_OK : On success
* - Any value other than ESP_OK will signal the server to close the socket immediately
*/
typedef esp_err_t (*httpd_open_func_t)(httpd_handle_t hd, int sockfd);
/**
* @brief Function prototype for closing a session.
*
* @note It's possible that the socket descriptor is invalid at this point, the function
* is called for all terminated sessions. Ensure proper handling of return codes.
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
*/
typedef void (*httpd_close_func_t)(httpd_handle_t hd, int sockfd);
/**
* @brief Function prototype for URI matching.
*
* @param[in] reference_uri URI/template with respect to which the other URI is matched
* @param[in] uri_to_match URI/template being matched to the reference URI/template
* @param[in] match_upto For specifying the actual length of `uri_to_match` up to
* which the matching algorithm is to be applied (The maximum
* value is `strlen(uri_to_match)`, independent of the length
* of `reference_uri`)
* @return true on match
*/
typedef bool (*httpd_uri_match_func_t)(const char *reference_uri,
const char *uri_to_match,
size_t match_upto);
/**
* @brief HTTP Server Configuration Structure
*
* @note Use HTTPD_DEFAULT_CONFIG() to initialize the configuration
* to a default value and then modify only those fields that are
* specifically determined by the use case.
*/
typedef struct httpd_config {
unsigned task_priority; /*!< Priority of FreeRTOS task which runs the server */
size_t stack_size; /*!< The maximum stack size allowed for the server task */
BaseType_t core_id; /*!< The core the HTTP server task will run on */
/**
* TCP Port number for receiving and transmitting HTTP traffic
*/
uint16_t server_port;
/**
* UDP Port number for asynchronously exchanging control signals
* between various components of the server
*/
uint16_t ctrl_port;
uint16_t max_open_sockets; /*!< Max number of sockets/clients connected at any time (3 sockets are reserved for internal working of the HTTP server) */
uint16_t max_uri_handlers; /*!< Maximum allowed uri handlers */
uint16_t max_resp_headers; /*!< Maximum allowed additional headers in HTTP response */
uint16_t backlog_conn; /*!< Number of backlog connections */
bool lru_purge_enable; /*!< Purge "Least Recently Used" connection */
uint16_t recv_wait_timeout; /*!< Timeout for recv function (in seconds)*/
uint16_t send_wait_timeout; /*!< Timeout for send function (in seconds)*/
/**
* Global user context.
*
* This field can be used to store arbitrary user data within the server context.
* The value can be retrieved using the server handle, available e.g. in the httpd_req_t struct.
*
* When shutting down, the server frees up the user context by
* calling free() on the global_user_ctx field. If you wish to use a custom
* function for freeing the global user context, please specify that here.
*/
void * global_user_ctx;
/**
* Free function for global user context
*/
httpd_free_ctx_fn_t global_user_ctx_free_fn;
/**
* Global transport context.
*
* Similar to global_user_ctx, but used for session encoding or encryption (e.g. to hold the SSL context).
* It will be freed using free(), unless global_transport_ctx_free_fn is specified.
*/
void * global_transport_ctx;
/**
* Free function for global transport context
*/
httpd_free_ctx_fn_t global_transport_ctx_free_fn;
bool enable_so_linger; /*!< bool to enable/disable linger */
int linger_timeout; /*!< linger timeout (in seconds) */
bool keep_alive_enable; /*!< Enable keep-alive timeout */
int keep_alive_idle; /*!< Keep-alive idle time. Default is 5 (second) */
int keep_alive_interval;/*!< Keep-alive interval time. Default is 5 (second) */
int keep_alive_count; /*!< Keep-alive packet retry send count. Default is 3 counts */
/**
* Custom session opening callback.
*
* Called on a new session socket just after accept(), but before reading any data.
*
* This is an opportunity to set up e.g. SSL encryption using global_transport_ctx
* and the send/recv/pending session overrides.
*
* If a context needs to be maintained between these functions, store it in the session using
* httpd_sess_set_transport_ctx() and retrieve it later with httpd_sess_get_transport_ctx()
*
* Returning a value other than ESP_OK will immediately close the new socket.
*/
httpd_open_func_t open_fn;
/**
* Custom session closing callback.
*
* Called when a session is deleted, before freeing user and transport contexts and before
* closing the socket. This is a place for custom de-init code common to all sockets.
*
* The server will only close the socket if no custom session closing callback is set.
* If a custom callback is used, `close(sockfd)` should be called in here for most cases.
*
* Set the user or transport context to NULL if it was freed here, so the server does not
* try to free it again.
*
* This function is run for all terminated sessions, including sessions where the socket
* was closed by the network stack - that is, the file descriptor may not be valid anymore.
*/
httpd_close_func_t close_fn;
/**
* URI matcher function.
*
* Called when searching for a matching URI:
* 1) whose request handler is to be executed right
* after an HTTP request is successfully parsed
* 2) in order to prevent duplication while registering
* a new URI handler using `httpd_register_uri_handler()`
*
* Available options are:
* 1) NULL : Internally do basic matching using `strncmp()`
* 2) `httpd_uri_match_wildcard()` : URI wildcard matcher
*
* Users can implement their own matching functions (See description
* of the `httpd_uri_match_func_t` function prototype)
*/
httpd_uri_match_func_t uri_match_fn;
} httpd_config_t;
/**
* @brief Starts the web server
*
* Create an instance of HTTP server and allocate memory/resources for it
* depending upon the specified configuration.
*
* Example usage:
* @code{c}
*
* //Function for starting the webserver
* httpd_handle_t start_webserver(void)
* {
* // Generate default configuration
* httpd_config_t config = HTTPD_DEFAULT_CONFIG();
*
* // Empty handle to http_server
* httpd_handle_t server = NULL;
*
* // Start the httpd server
* if (httpd_start(&server, &config) == ESP_OK) {
* // Register URI handlers
* httpd_register_uri_handler(server, &uri_get);
* httpd_register_uri_handler(server, &uri_post);
* }
* // If server failed to start, handle will be NULL
* return server;
* }
*
* @endcode
*
* @param[in] config Configuration for new instance of the server
* @param[out] handle Handle to newly created instance of the server. NULL on error
* @return
* - ESP_OK : Instance created successfully
* - ESP_ERR_INVALID_ARG : Null argument(s)
* - ESP_ERR_HTTPD_ALLOC_MEM : Failed to allocate memory for instance
* - ESP_ERR_HTTPD_TASK : Failed to launch server task
*/
esp_err_t httpd_start(httpd_handle_t *handle, const httpd_config_t *config);
/**
* @brief Stops the web server
*
* Deallocates memory/resources used by an HTTP server instance and
* deletes it. Once deleted the handle can no longer be used for accessing
* the instance.
*
* Example usage:
* @code{c}
*
* // Function for stopping the webserver
* void stop_webserver(httpd_handle_t server)
* {
* // Ensure handle is non NULL
* if (server != NULL) {
* // Stop the httpd server
* httpd_stop(server);
* }
* }
*
* @endcode
*
* @param[in] handle Handle to server returned by httpd_start
* @return
* - ESP_OK : Server stopped successfully
* - ESP_ERR_INVALID_ARG : Handle argument is Null
*/
esp_err_t httpd_stop(httpd_handle_t handle);
/** End of Group Initialization
* @}
*/
/* ************** Group: URI Handlers ************** */
/** @name URI Handlers
* APIs related to the URI handlers
* @{
*/
/* Max supported HTTP request header length */
#define HTTPD_MAX_REQ_HDR_LEN CONFIG_HTTPD_MAX_REQ_HDR_LEN
/* Max supported HTTP request URI length */
#define HTTPD_MAX_URI_LEN CONFIG_HTTPD_MAX_URI_LEN
/**
* @brief HTTP Request Data Structure
*/
typedef struct httpd_req {
httpd_handle_t handle; /*!< Handle to server instance */
int method; /*!< The type of HTTP request, -1 if unsupported method */
const char uri[HTTPD_MAX_URI_LEN + 1]; /*!< The URI of this request (1 byte extra for null termination) */
size_t content_len; /*!< Length of the request body */
void *aux; /*!< Internally used members */
/**
* User context pointer passed during URI registration.
*/
void *user_ctx;
/**
* Session Context Pointer
*
* A session context. Contexts are maintained across 'sessions' for a
* given open TCP connection. One session could have multiple request
* responses. The web server will ensure that the context persists
* across all these request and responses.
*
* By default, this is NULL. URI Handlers can set this to any meaningful
* value.
*
* If the underlying socket gets closed, and this pointer is non-NULL,
* the web server will free up the context by calling free(), unless
* free_ctx function is set.
*/
void *sess_ctx;
/**
* Pointer to free context hook
*
* Function to free session context
*
* If the web server's socket closes, it frees up the session context by
* calling free() on the sess_ctx member. If you wish to use a custom
* function for freeing the session context, please specify that here.
*/
httpd_free_ctx_fn_t free_ctx;
/**
* Flag indicating if Session Context changes should be ignored
*
* By default, if you change the sess_ctx in some URI handler, the http server
* will internally free the earlier context (if non NULL), after the URI handler
* returns. If you want to manage the allocation/reallocation/freeing of
* sess_ctx yourself, set this flag to true, so that the server will not
* perform any checks on it. The context will be cleared by the server
* (by calling free_ctx or free()) only if the socket gets closed.
*/
bool ignore_sess_ctx_changes;
} httpd_req_t;
/**
* @brief Structure for URI handler
*/
typedef struct httpd_uri {
const char *uri; /*!< The URI to handle */
httpd_method_t method; /*!< Method supported by the URI */
/**
* Handler to call for supported request method. This must
* return ESP_OK, or else the underlying socket will be closed.
*/
esp_err_t (*handler)(httpd_req_t *r);
/**
* Pointer to user context data which will be available to handler
*/
void *user_ctx;
#ifdef CONFIG_HTTPD_WS_SUPPORT
/**
* Flag for indicating a WebSocket endpoint.
* If this flag is true, then method must be HTTP_GET. Otherwise the handshake will not be handled.
*/
bool is_websocket;
/**
* Flag indicating that control frames (PING, PONG, CLOSE) are also passed to the handler
* This is used if a custom processing of the control frames is needed
*/
bool handle_ws_control_frames;
/**
* Pointer to subprotocol supported by URI
*/
const char *supported_subprotocol;
#endif
} httpd_uri_t;
/**
* @brief Registers a URI handler
*
* @note URI handlers can be registered in real time as long as the
* server handle is valid.
*
* Example usage:
* @code{c}
*
* esp_err_t my_uri_handler(httpd_req_t* req)
* {
* // Recv , Process and Send
* ....
* ....
* ....
*
* // Fail condition
* if (....) {
* // Return fail to close session //
* return ESP_FAIL;
* }
*
* // On success
* return ESP_OK;
* }
*
* // URI handler structure
* httpd_uri_t my_uri {
* .uri = "/my_uri/path/xyz",
* .method = HTTPD_GET,
* .handler = my_uri_handler,
* .user_ctx = NULL
* };
*
* // Register handler
* if (httpd_register_uri_handler(server_handle, &my_uri) != ESP_OK) {
* // If failed to register handler
* ....
* }
*
* @endcode
*
* @param[in] handle handle to HTTPD server instance
* @param[in] uri_handler pointer to handler that needs to be registered
*
* @return
* - ESP_OK : On successfully registering the handler
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_HANDLERS_FULL : If no slots left for new handler
* - ESP_ERR_HTTPD_HANDLER_EXISTS : If handler with same URI and
* method is already registered
*/
esp_err_t httpd_register_uri_handler(httpd_handle_t handle,
const httpd_uri_t *uri_handler);
/**
* @brief Unregister a URI handler
*
* @param[in] handle handle to HTTPD server instance
* @param[in] uri URI string
* @param[in] method HTTP method
*
* @return
* - ESP_OK : On successfully deregistering the handler
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_NOT_FOUND : Handler with specified URI and method not found
*/
esp_err_t httpd_unregister_uri_handler(httpd_handle_t handle,
const char *uri, httpd_method_t method);
/**
* @brief Unregister all URI handlers with the specified uri string
*
* @param[in] handle handle to HTTPD server instance
* @param[in] uri uri string specifying all handlers that need
* to be deregisterd
*
* @return
* - ESP_OK : On successfully deregistering all such handlers
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_NOT_FOUND : No handler registered with specified uri string
*/
esp_err_t httpd_unregister_uri(httpd_handle_t handle, const char* uri);
/** End of URI Handlers
* @}
*/
/* ************** Group: HTTP Error ************** */
/** @name HTTP Error
* Prototype for HTTP errors and error handling functions
* @{
*/
/**
* @brief Error codes sent as HTTP response in case of errors
* encountered during processing of an HTTP request
*/
typedef enum {
/* For any unexpected errors during parsing, like unexpected
* state transitions, or unhandled errors.
*/
HTTPD_500_INTERNAL_SERVER_ERROR = 0,
/* For methods not supported by http_parser. Presently
* http_parser halts parsing when such methods are
* encountered and so the server responds with 400 Bad
* Request error instead.
*/
HTTPD_501_METHOD_NOT_IMPLEMENTED,
/* When HTTP version is not 1.1 */
HTTPD_505_VERSION_NOT_SUPPORTED,
/* Returned when http_parser halts parsing due to incorrect
* syntax of request, unsupported method in request URI or
* due to chunked encoding / upgrade field present in headers
*/
HTTPD_400_BAD_REQUEST,
/* This response means the client must authenticate itself
* to get the requested response.
*/
HTTPD_401_UNAUTHORIZED,
/* The client does not have access rights to the content,
* so the server is refusing to give the requested resource.
* Unlike 401, the client's identity is known to the server.
*/
HTTPD_403_FORBIDDEN,
/* When requested URI is not found */
HTTPD_404_NOT_FOUND,
/* When URI found, but method has no handler registered */
HTTPD_405_METHOD_NOT_ALLOWED,
/* Intended for recv timeout. Presently it's being sent
* for other recv errors as well. Client should expect the
* server to immediately close the connection after
* responding with this.
*/
HTTPD_408_REQ_TIMEOUT,
/* Intended for responding to chunked encoding, which is
* not supported currently. Though unhandled http_parser
* callback for chunked request returns "400 Bad Request"
*/
HTTPD_411_LENGTH_REQUIRED,
/* URI length greater than CONFIG_HTTPD_MAX_URI_LEN */
HTTPD_414_URI_TOO_LONG,
/* Headers section larger than CONFIG_HTTPD_MAX_REQ_HDR_LEN */
HTTPD_431_REQ_HDR_FIELDS_TOO_LARGE,
/* Used internally for retrieving the total count of errors */
HTTPD_ERR_CODE_MAX
} httpd_err_code_t;
/**
* @brief Function prototype for HTTP error handling.
*
* This function is executed upon HTTP errors generated during
* internal processing of an HTTP request. This is used to override
* the default behavior on error, which is to send HTTP error response
* and close the underlying socket.
*
* @note
* - If implemented, the server will not automatically send out HTTP
* error response codes, therefore, httpd_resp_send_err() must be
* invoked inside this function if user wishes to generate HTTP
* error responses.
* - When invoked, the validity of `uri`, `method`, `content_len`
* and `user_ctx` fields of the httpd_req_t parameter is not
* guaranteed as the HTTP request may be partially received/parsed.
* - The function must return ESP_OK if underlying socket needs to
* be kept open. Any other value will ensure that the socket is
* closed. The return value is ignored when error is of type
* `HTTPD_500_INTERNAL_SERVER_ERROR` and the socket closed anyway.
*
* @param[in] req HTTP request for which the error needs to be handled
* @param[in] error Error type
*
* @return
* - ESP_OK : error handled successful
* - ESP_FAIL : failure indicates that the underlying socket needs to be closed
*/
typedef esp_err_t (*httpd_err_handler_func_t)(httpd_req_t *req,
httpd_err_code_t error);
/**
* @brief Function for registering HTTP error handlers
*
* This function maps a handler function to any supported error code
* given by `httpd_err_code_t`. See prototype `httpd_err_handler_func_t`
* above for details.
*
* @param[in] handle HTTP server handle
* @param[in] error Error type
* @param[in] handler_fn User implemented handler function
* (Pass NULL to unset any previously set handler)
*
* @return
* - ESP_OK : handler registered successfully
* - ESP_ERR_INVALID_ARG : invalid error code or server handle
*/
esp_err_t httpd_register_err_handler(httpd_handle_t handle,
httpd_err_code_t error,
httpd_err_handler_func_t handler_fn);
/** End of HTTP Error
* @}
*/
/* ************** Group: TX/RX ************** */
/** @name TX / RX
* Prototype for HTTPDs low-level send/recv functions
* @{
*/
#define HTTPD_SOCK_ERR_FAIL -1
#define HTTPD_SOCK_ERR_INVALID -2
#define HTTPD_SOCK_ERR_TIMEOUT -3
/**
* @brief Prototype for HTTPDs low-level send function
*
* @note User specified send function must handle errors internally,
* depending upon the set value of errno, and return specific
* HTTPD_SOCK_ERR_ codes, which will eventually be conveyed as
* return value of httpd_send() function
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
* @param[in] buf buffer with bytes to send
* @param[in] buf_len data size
* @param[in] flags flags for the send() function
* @return
* - Bytes : The number of bytes sent successfully
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket send()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket send()
*/
typedef int (*httpd_send_func_t)(httpd_handle_t hd, int sockfd, const char *buf, size_t buf_len, int flags);
/**
* @brief Prototype for HTTPDs low-level recv function
*
* @note User specified recv function must handle errors internally,
* depending upon the set value of errno, and return specific
* HTTPD_SOCK_ERR_ codes, which will eventually be conveyed as
* return value of httpd_req_recv() function
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
* @param[in] buf buffer with bytes to send
* @param[in] buf_len data size
* @param[in] flags flags for the send() function
* @return
* - Bytes : The number of bytes received successfully
* - 0 : Buffer length parameter is zero / connection closed by peer
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket recv()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket recv()
*/
typedef int (*httpd_recv_func_t)(httpd_handle_t hd, int sockfd, char *buf, size_t buf_len, int flags);
/**
* @brief Prototype for HTTPDs low-level "get pending bytes" function
*
* @note User specified pending function must handle errors internally,
* depending upon the set value of errno, and return specific
* HTTPD_SOCK_ERR_ codes, which will be handled accordingly in
* the server task.
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
* @return
* - Bytes : The number of bytes waiting to be received
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket pending()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket pending()
*/
typedef int (*httpd_pending_func_t)(httpd_handle_t hd, int sockfd);
/** End of TX / RX
* @}
*/
/* ************** Group: Request/Response ************** */
/** @name Request / Response
* APIs related to the data send/receive by URI handlers.
* These APIs are supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* @{
*/
/**
* @brief Override web server's receive function (by session FD)
*
* This function overrides the web server's receive function. This same function is
* used to read HTTP request packets.
*
* @note This API is supposed to be called either from the context of
* - an http session APIs where sockfd is a valid parameter
* - a URI handler where sockfd is obtained using httpd_req_to_sockfd()
*
* @param[in] hd HTTPD instance handle
* @param[in] sockfd Session socket FD
* @param[in] recv_func The receive function to be set for this session
*
* @return
* - ESP_OK : On successfully registering override
* - ESP_ERR_INVALID_ARG : Null arguments
*/
esp_err_t httpd_sess_set_recv_override(httpd_handle_t hd, int sockfd, httpd_recv_func_t recv_func);
/**
* @brief Override web server's send function (by session FD)
*
* This function overrides the web server's send function. This same function is
* used to send out any response to any HTTP request.
*
* @note This API is supposed to be called either from the context of
* - an http session APIs where sockfd is a valid parameter
* - a URI handler where sockfd is obtained using httpd_req_to_sockfd()
*
* @param[in] hd HTTPD instance handle
* @param[in] sockfd Session socket FD
* @param[in] send_func The send function to be set for this session
*
* @return
* - ESP_OK : On successfully registering override
* - ESP_ERR_INVALID_ARG : Null arguments
*/
esp_err_t httpd_sess_set_send_override(httpd_handle_t hd, int sockfd, httpd_send_func_t send_func);
/**
* @brief Override web server's pending function (by session FD)
*
* This function overrides the web server's pending function. This function is
* used to test for pending bytes in a socket.
*
* @note This API is supposed to be called either from the context of
* - an http session APIs where sockfd is a valid parameter
* - a URI handler where sockfd is obtained using httpd_req_to_sockfd()
*
* @param[in] hd HTTPD instance handle
* @param[in] sockfd Session socket FD
* @param[in] pending_func The receive function to be set for this session
*
* @return
* - ESP_OK : On successfully registering override
* - ESP_ERR_INVALID_ARG : Null arguments
*/
esp_err_t httpd_sess_set_pending_override(httpd_handle_t hd, int sockfd, httpd_pending_func_t pending_func);
/**
* @brief Start an asynchronous request. This function can be called
* in a request handler to get a request copy that can be used on a async thread.
*
* @note
* - This function is necessary in order to handle multiple requests simultaneously.
* See examples/async_requests for example usage.
* - You must call httpd_req_async_handler_complete() when you are done with the request.
*
* @param[in] r The request to create an async copy of
* @param[out] out A newly allocated request which can be used on an async thread
*
* @return
* - ESP_OK : async request object created
*/
esp_err_t httpd_req_async_handler_begin(httpd_req_t *r, httpd_req_t **out);
/**
* @brief Mark an asynchronous request as completed. This will
* - free the request memory
* - relinquish ownership of the underlying socket, so it can be reused.
* - allow the http server to close our socket if needed (lru_purge_enable)
*
* @note If async requests are not marked completed, eventually the server
* will no longer accept incoming connections. The server will log a
* "httpd_accept_conn: error in accept (23)" message if this happens.
*
* @param[in] r The request to mark async work as completed
*
* @return
* - ESP_OK : async request was marked completed
*/
esp_err_t httpd_req_async_handler_complete(httpd_req_t *r);
/**
* @brief Get the Socket Descriptor from the HTTP request
*
* This API will return the socket descriptor of the session for
* which URI handler was executed on reception of HTTP request.
* This is useful when user wants to call functions that require
* session socket fd, from within a URI handler, ie. :
* httpd_sess_get_ctx(),
* httpd_sess_trigger_close(),
* httpd_sess_update_lru_counter().
*
* @note This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
*
* @param[in] r The request whose socket descriptor should be found
*
* @return
* - Socket descriptor : The socket descriptor for this request
* - -1 : Invalid/NULL request pointer
*/
int httpd_req_to_sockfd(httpd_req_t *r);
/**
* @brief API to read content data from the HTTP request
*
* This API will read HTTP content data from the HTTP request into
* provided buffer. Use content_len provided in httpd_req_t structure
* to know the length of data to be fetched. If content_len is too
* large for the buffer then user may have to make multiple calls to
* this function, each time fetching 'buf_len' number of bytes,
* while the pointer to content data is incremented internally by
* the same number.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - If an error is returned, the URI handler must further return an error.
* This will ensure that the erroneous socket is closed and cleaned up by
* the web server.
* - Presently Chunked Encoding is not supported
*
* @param[in] r The request being responded to
* @param[in] buf Pointer to a buffer that the data will be read into
* @param[in] buf_len Length of the buffer
*
* @return
* - Bytes : Number of bytes read into the buffer successfully
* - 0 : Buffer length parameter is zero / connection closed by peer
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket recv()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket recv()
*/
int httpd_req_recv(httpd_req_t *r, char *buf, size_t buf_len);
/**
* @brief Search for a field in request headers and
* return the string length of it's value
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once httpd_resp_send() API is called all request headers
* are purged, so request headers need be copied into separate
* buffers if they are required later.
*
* @param[in] r The request being responded to
* @param[in] field The header field to be searched in the request
*
* @return
* - Length : If field is found in the request URL
* - Zero : Field not found / Invalid request / Null arguments
*/
size_t httpd_req_get_hdr_value_len(httpd_req_t *r, const char *field);
/**
* @brief Get the value string of a field from the request headers
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once httpd_resp_send() API is called all request headers
* are purged, so request headers need be copied into separate
* buffers if they are required later.
* - If output size is greater than input, then the value is truncated,
* accompanied by truncation error as return value.
* - Use httpd_req_get_hdr_value_len() to know the right buffer length
*
* @param[in] r The request being responded to
* @param[in] field The field to be searched in the header
* @param[out] val Pointer to the buffer into which the value will be copied if the field is found
* @param[in] val_size Size of the user buffer "val"
*
* @return
* - ESP_OK : Field found in the request header and value string copied
* - ESP_ERR_NOT_FOUND : Key not found
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid HTTP request pointer
* - ESP_ERR_HTTPD_RESULT_TRUNC : Value string truncated
*/
esp_err_t httpd_req_get_hdr_value_str(httpd_req_t *r, const char *field, char *val, size_t val_size);
/**
* @brief Get Query string length from the request URL
*
* @note This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid
*
* @param[in] r The request being responded to
*
* @return
* - Length : Query is found in the request URL
* - Zero : Query not found / Null arguments / Invalid request
*/
size_t httpd_req_get_url_query_len(httpd_req_t *r);
/**
* @brief Get Query string from the request URL
*
* @note
* - Presently, the user can fetch the full URL query string, but decoding
* will have to be performed by the user. Request headers can be read using
* httpd_req_get_hdr_value_str() to know the 'Content-Type' (eg. Content-Type:
* application/x-www-form-urlencoded) and then the appropriate decoding
* algorithm needs to be applied.
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid
* - If output size is greater than input, then the value is truncated,
* accompanied by truncation error as return value
* - Prior to calling this function, one can use httpd_req_get_url_query_len()
* to know the query string length beforehand and hence allocate the buffer
* of right size (usually query string length + 1 for null termination)
* for storing the query string
*
* @param[in] r The request being responded to
* @param[out] buf Pointer to the buffer into which the query string will be copied (if found)
* @param[in] buf_len Length of output buffer
*
* @return
* - ESP_OK : Query is found in the request URL and copied to buffer
* - ESP_ERR_NOT_FOUND : Query not found
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid HTTP request pointer
* - ESP_ERR_HTTPD_RESULT_TRUNC : Query string truncated
*/
esp_err_t httpd_req_get_url_query_str(httpd_req_t *r, char *buf, size_t buf_len);
/**
* @brief Helper function to get a URL query tag from a query
* string of the type param1=val1&param2=val2
*
* @note
* - The components of URL query string (keys and values) are not URLdecoded.
* The user must check for 'Content-Type' field in the request headers and
* then depending upon the specified encoding (URLencoded or otherwise) apply
* the appropriate decoding algorithm.
* - If actual value size is greater than val_size, then the value is truncated,
* accompanied by truncation error as return value.
*
* @param[in] qry Pointer to query string
* @param[in] key The key to be searched in the query string
* @param[out] val Pointer to the buffer into which the value will be copied if the key is found
* @param[in] val_size Size of the user buffer "val"
*
* @return
* - ESP_OK : Key is found in the URL query string and copied to buffer
* - ESP_ERR_NOT_FOUND : Key not found
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESULT_TRUNC : Value string truncated
*/
esp_err_t httpd_query_key_value(const char *qry, const char *key, char *val, size_t val_size);
/**
* @brief Get the value string of a cookie value from the "Cookie" request headers by cookie name.
*
* @param[in] req Pointer to the HTTP request
* @param[in] cookie_name The cookie name to be searched in the request
* @param[out] val Pointer to the buffer into which the value of cookie will be copied if the cookie is found
* @param[inout] val_size Pointer to size of the user buffer "val". This variable will contain cookie length if
* ESP_OK is returned and required buffer length incase ESP_ERR_HTTPD_RESULT_TRUNC is returned.
*
* @return
* - ESP_OK : Key is found in the cookie string and copied to buffer
* - ESP_ERR_NOT_FOUND : Key not found
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESULT_TRUNC : Value string truncated
* - ESP_ERR_NO_MEM : Memory allocation failure
*/
esp_err_t httpd_req_get_cookie_val(httpd_req_t *req, const char *cookie_name, char *val, size_t *val_size);
/**
* @brief Test if a URI matches the given wildcard template.
*
* Template may end with "?" to make the previous character optional (typically a slash),
* "*" for a wildcard match, and "?*" to make the previous character optional, and if present,
* allow anything to follow.
*
* Example:
* - * matches everything
* - /foo/? matches /foo and /foo/
* - /foo/\* (sans the backslash) matches /foo/ and /foo/bar, but not /foo or /fo
* - /foo/?* or /foo/\*? (sans the backslash) matches /foo/, /foo/bar, and also /foo, but not /foox or /fo
*
* The special characters "?" and "*" anywhere else in the template will be taken literally.
*
* @param[in] uri_template URI template (pattern)
* @param[in] uri_to_match URI to be matched
* @param[in] match_upto how many characters of the URI buffer to test
* (there may be trailing query string etc.)
*
* @return true if a match was found
*/
bool httpd_uri_match_wildcard(const char *uri_template, const char *uri_to_match, size_t match_upto);
/**
* @brief API to send a complete HTTP response.
*
* This API will send the data as an HTTP response to the request.
* This assumes that you have the entire response ready in a single
* buffer. If you wish to send response in incremental chunks use
* httpd_resp_send_chunk() instead.
*
* If no status code and content-type were set, by default this
* will send 200 OK status code and content type as text/html.
* You may call the following functions before this API to configure
* the response headers :
* httpd_resp_set_status() - for setting the HTTP status string,
* httpd_resp_set_type() - for setting the Content Type,
* httpd_resp_set_hdr() - for appending any additional field
* value entries in the response header
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once this API is called, the request has been responded to.
* - No additional data can then be sent for the request.
* - Once this API is called, all request headers are purged, so
* request headers need be copied into separate buffers if
* they are required later.
*
* @param[in] r The request being responded to
* @param[in] buf Buffer from where the content is to be fetched
* @param[in] buf_len Length of the buffer, HTTPD_RESP_USE_STRLEN to use strlen()
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null request pointer
* - ESP_ERR_HTTPD_RESP_HDR : Essential headers are too large for internal buffer
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request
*/
esp_err_t httpd_resp_send(httpd_req_t *r, const char *buf, ssize_t buf_len);
/**
* @brief API to send one HTTP chunk
*
* This API will send the data as an HTTP response to the
* request. This API will use chunked-encoding and send the response
* in the form of chunks. If you have the entire response contained in
* a single buffer, please use httpd_resp_send() instead.
*
* If no status code and content-type were set, by default this will
* send 200 OK status code and content type as text/html. You may
* call the following functions before this API to configure the
* response headers
* httpd_resp_set_status() - for setting the HTTP status string,
* httpd_resp_set_type() - for setting the Content Type,
* httpd_resp_set_hdr() - for appending any additional field
* value entries in the response header
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - When you are finished sending all your chunks, you must call
* this function with buf_len as 0.
* - Once this API is called, all request headers are purged, so
* request headers need be copied into separate buffers if they
* are required later.
*
* @param[in] r The request being responded to
* @param[in] buf Pointer to a buffer that stores the data
* @param[in] buf_len Length of the buffer, HTTPD_RESP_USE_STRLEN to use strlen()
*
* @return
* - ESP_OK : On successfully sending the response packet chunk
* - ESP_ERR_INVALID_ARG : Null request pointer
* - ESP_ERR_HTTPD_RESP_HDR : Essential headers are too large for internal buffer
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
esp_err_t httpd_resp_send_chunk(httpd_req_t *r, const char *buf, ssize_t buf_len);
/**
* @brief API to send a complete string as HTTP response.
*
* This API simply calls http_resp_send with buffer length
* set to string length assuming the buffer contains a null
* terminated string
*
* @param[in] r The request being responded to
* @param[in] str String to be sent as response body
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null request pointer
* - ESP_ERR_HTTPD_RESP_HDR : Essential headers are too large for internal buffer
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request
*/
static inline esp_err_t httpd_resp_sendstr(httpd_req_t *r, const char *str) {
return httpd_resp_send(r, str, (str == NULL) ? 0 : HTTPD_RESP_USE_STRLEN);
}
/**
* @brief API to send a string as an HTTP response chunk.
*
* This API simply calls http_resp_send_chunk with buffer length
* set to string length assuming the buffer contains a null
* terminated string
*
* @param[in] r The request being responded to
* @param[in] str String to be sent as response body (NULL to finish response packet)
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null request pointer
* - ESP_ERR_HTTPD_RESP_HDR : Essential headers are too large for internal buffer
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request
*/
static inline esp_err_t httpd_resp_sendstr_chunk(httpd_req_t *r, const char *str) {
return httpd_resp_send_chunk(r, str, (str == NULL) ? 0 : HTTPD_RESP_USE_STRLEN);
}
/* Some commonly used status codes */
#define HTTPD_200 "200 OK" /*!< HTTP Response 200 */
#define HTTPD_204 "204 No Content" /*!< HTTP Response 204 */
#define HTTPD_207 "207 Multi-Status" /*!< HTTP Response 207 */
#define HTTPD_400 "400 Bad Request" /*!< HTTP Response 400 */
#define HTTPD_404 "404 Not Found" /*!< HTTP Response 404 */
#define HTTPD_408 "408 Request Timeout" /*!< HTTP Response 408 */
#define HTTPD_500 "500 Internal Server Error" /*!< HTTP Response 500 */
/**
* @brief API to set the HTTP status code
*
* This API sets the status of the HTTP response to the value specified.
* By default, the '200 OK' response is sent as the response.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - This API only sets the status to this value. The status isn't
* sent out until any of the send APIs is executed.
* - Make sure that the lifetime of the status string is valid till
* send function is called.
*
* @param[in] r The request being responded to
* @param[in] status The HTTP status code of this response
*
* @return
* - ESP_OK : On success
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
esp_err_t httpd_resp_set_status(httpd_req_t *r, const char *status);
/* Some commonly used content types */
#define HTTPD_TYPE_JSON "application/json" /*!< HTTP Content type JSON */
#define HTTPD_TYPE_TEXT "text/html" /*!< HTTP Content type text/HTML */
#define HTTPD_TYPE_OCTET "application/octet-stream" /*!< HTTP Content type octext-stream */
/**
* @brief API to set the HTTP content type
*
* This API sets the 'Content Type' field of the response.
* The default content type is 'text/html'.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - This API only sets the content type to this value. The type
* isn't sent out until any of the send APIs is executed.
* - Make sure that the lifetime of the type string is valid till
* send function is called.
*
* @param[in] r The request being responded to
* @param[in] type The Content Type of the response
*
* @return
* - ESP_OK : On success
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
esp_err_t httpd_resp_set_type(httpd_req_t *r, const char *type);
/**
* @brief API to append any additional headers
*
* This API sets any additional header fields that need to be sent in the response.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - The header isn't sent out until any of the send APIs is executed.
* - The maximum allowed number of additional headers is limited to
* value of max_resp_headers in config structure.
* - Make sure that the lifetime of the field value strings are valid till
* send function is called.
*
* @param[in] r The request being responded to
* @param[in] field The field name of the HTTP header
* @param[in] value The value of this HTTP header
*
* @return
* - ESP_OK : On successfully appending new header
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESP_HDR : Total additional headers exceed max allowed
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
esp_err_t httpd_resp_set_hdr(httpd_req_t *r, const char *field, const char *value);
/**
* @brief For sending out error code in response to HTTP request.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once this API is called, all request headers are purged, so
* request headers need be copied into separate buffers if
* they are required later.
* - If you wish to send additional data in the body of the
* response, please use the lower-level functions directly.
*
* @param[in] req Pointer to the HTTP request for which the response needs to be sent
* @param[in] error Error type to send
* @param[in] msg Error message string (pass NULL for default message)
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
esp_err_t httpd_resp_send_err(httpd_req_t *req, httpd_err_code_t error, const char *msg);
/**
* @brief Helper function for HTTP 404
*
* Send HTTP 404 message. If you wish to send additional data in the body of the
* response, please use the lower-level functions directly.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once this API is called, all request headers are purged, so
* request headers need be copied into separate buffers if
* they are required later.
*
* @param[in] r The request being responded to
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
static inline esp_err_t httpd_resp_send_404(httpd_req_t *r) {
return httpd_resp_send_err(r, HTTPD_404_NOT_FOUND, NULL);
}
/**
* @brief Helper function for HTTP 408
*
* Send HTTP 408 message. If you wish to send additional data in the body of the
* response, please use the lower-level functions directly.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once this API is called, all request headers are purged, so
* request headers need be copied into separate buffers if
* they are required later.
*
* @param[in] r The request being responded to
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
static inline esp_err_t httpd_resp_send_408(httpd_req_t *r) {
return httpd_resp_send_err(r, HTTPD_408_REQ_TIMEOUT, NULL);
}
/**
* @brief Helper function for HTTP 500
*
* Send HTTP 500 message. If you wish to send additional data in the body of the
* response, please use the lower-level functions directly.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Once this API is called, all request headers are purged, so
* request headers need be copied into separate buffers if
* they are required later.
*
* @param[in] r The request being responded to
*
* @return
* - ESP_OK : On successfully sending the response packet
* - ESP_ERR_INVALID_ARG : Null arguments
* - ESP_ERR_HTTPD_RESP_SEND : Error in raw send
* - ESP_ERR_HTTPD_INVALID_REQ : Invalid request pointer
*/
static inline esp_err_t httpd_resp_send_500(httpd_req_t *r) {
return httpd_resp_send_err(r, HTTPD_500_INTERNAL_SERVER_ERROR, NULL);
}
/**
* @brief Raw HTTP send
*
* Call this API if you wish to construct your custom response packet.
* When using this, all essential header, eg. HTTP version, Status Code,
* Content Type and Length, Encoding, etc. will have to be constructed
* manually, and HTTP delimeters (CRLF) will need to be placed correctly
* for separating sub-sections of the HTTP response packet.
*
* If the send override function is set, this API will end up
* calling that function eventually to send data out.
*
* @note
* - This API is supposed to be called only from the context of
* a URI handler where httpd_req_t* request pointer is valid.
* - Unless the response has the correct HTTP structure (which the
* user must now ensure) it is not guaranteed that it will be
* recognized by the client. For most cases, you wouldn't have
* to call this API, but you would rather use either of :
* httpd_resp_send(),
* httpd_resp_send_chunk()
*
* @param[in] r The request being responded to
* @param[in] buf Buffer from where the fully constructed packet is to be read
* @param[in] buf_len Length of the buffer
*
* @return
* - Bytes : Number of bytes that were sent successfully
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket send()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket send()
*/
int httpd_send(httpd_req_t *r, const char *buf, size_t buf_len);
/**
* A low level API to send data on a given socket
*
* @note This API is not recommended to be used in any request handler.
* Use this only for advanced use cases, wherein some asynchronous
* data is to be sent over a socket.
*
* This internally calls the default send function, or the function registered by
* httpd_sess_set_send_override().
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
* @param[in] buf buffer with bytes to send
* @param[in] buf_len data size
* @param[in] flags flags for the send() function
* @return
* - Bytes : The number of bytes sent successfully
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket send()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket send()
*/
int httpd_socket_send(httpd_handle_t hd, int sockfd, const char *buf, size_t buf_len, int flags);
/**
* A low level API to receive data from a given socket
*
* @note This API is not recommended to be used in any request handler.
* Use this only for advanced use cases, wherein some asynchronous
* communication is required.
*
* This internally calls the default recv function, or the function registered by
* httpd_sess_set_recv_override().
*
* @param[in] hd server instance
* @param[in] sockfd session socket file descriptor
* @param[in] buf buffer with bytes to send
* @param[in] buf_len data size
* @param[in] flags flags for the send() function
* @return
* - Bytes : The number of bytes received successfully
* - 0 : Buffer length parameter is zero / connection closed by peer
* - HTTPD_SOCK_ERR_INVALID : Invalid arguments
* - HTTPD_SOCK_ERR_TIMEOUT : Timeout/interrupted while calling socket recv()
* - HTTPD_SOCK_ERR_FAIL : Unrecoverable error while calling socket recv()
*/
int httpd_socket_recv(httpd_handle_t hd, int sockfd, char *buf, size_t buf_len, int flags);
/** End of Request / Response
* @}
*/
/* ************** Group: Session ************** */
/** @name Session
* Functions for controlling sessions and accessing context data
* @{
*/
/**
* @brief Get session context from socket descriptor
*
* Typically if a session context is created, it is available to URI handlers
* through the httpd_req_t structure. But, there are cases where the web
* server's send/receive functions may require the context (for example, for
* accessing keying information etc). Since the send/receive function only have
* the socket descriptor at their disposal, this API provides them with a way to
* retrieve the session context.
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] sockfd The socket descriptor for which the context should be extracted.
*
* @return
* - void* : Pointer to the context associated with this session
* - NULL : Empty context / Invalid handle / Invalid socket fd
*/
void *httpd_sess_get_ctx(httpd_handle_t handle, int sockfd);
/**
* @brief Set session context by socket descriptor
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] sockfd The socket descriptor for which the context should be extracted.
* @param[in] ctx Context object to assign to the session
* @param[in] free_fn Function that should be called to free the context
*/
void httpd_sess_set_ctx(httpd_handle_t handle, int sockfd, void *ctx, httpd_free_ctx_fn_t free_fn);
/**
* @brief Get session 'transport' context by socket descriptor
* @see httpd_sess_get_ctx()
*
* This context is used by the send/receive functions, for example to manage SSL context.
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] sockfd The socket descriptor for which the context should be extracted.
* @return
* - void* : Pointer to the transport context associated with this session
* - NULL : Empty context / Invalid handle / Invalid socket fd
*/
void *httpd_sess_get_transport_ctx(httpd_handle_t handle, int sockfd);
/**
* @brief Set session 'transport' context by socket descriptor
* @see httpd_sess_set_ctx()
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] sockfd The socket descriptor for which the context should be extracted.
* @param[in] ctx Transport context object to assign to the session
* @param[in] free_fn Function that should be called to free the transport context
*/
void httpd_sess_set_transport_ctx(httpd_handle_t handle, int sockfd, void *ctx, httpd_free_ctx_fn_t free_fn);
/**
* @brief Get HTTPD global user context (it was set in the server config struct)
*
* @param[in] handle Handle to server returned by httpd_start
* @return global user context
*/
void *httpd_get_global_user_ctx(httpd_handle_t handle);
/**
* @brief Get HTTPD global transport context (it was set in the server config struct)
*
* @param[in] handle Handle to server returned by httpd_start
* @return global transport context
*/
void *httpd_get_global_transport_ctx(httpd_handle_t handle);
/**
* @brief Trigger an httpd session close externally
*
* @note Calling this API is only required in special circumstances wherein
* some application requires to close an httpd client session asynchronously.
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] sockfd The socket descriptor of the session to be closed
*
* @return
* - ESP_OK : On successfully initiating closure
* - ESP_FAIL : Failure to queue work
* - ESP_ERR_NOT_FOUND : Socket fd not found
* - ESP_ERR_INVALID_ARG : Null arguments
*/
esp_err_t httpd_sess_trigger_close(httpd_handle_t handle, int sockfd);
/**
* @brief Update LRU counter for a given socket
*
* LRU Counters are internally associated with each session to monitor
* how recently a session exchanged traffic. When LRU purge is enabled,
* if a client is requesting for connection but maximum number of
* sockets/sessions is reached, then the session having the earliest
* LRU counter is closed automatically.
*
* Updating the LRU counter manually prevents the socket from being purged
* due to the Least Recently Used (LRU) logic, even though it might not
* have received traffic for some time. This is useful when all open
* sockets/session are frequently exchanging traffic but the user specifically
* wants one of the sessions to be kept open, irrespective of when it last
* exchanged a packet.
*
* @note Calling this API is only necessary if the LRU Purge Enable option
* is enabled.
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] sockfd The socket descriptor of the session for which LRU counter
* is to be updated
*
* @return
* - ESP_OK : Socket found and LRU counter updated
* - ESP_ERR_NOT_FOUND : Socket not found
* - ESP_ERR_INVALID_ARG : Null arguments
*/
esp_err_t httpd_sess_update_lru_counter(httpd_handle_t handle, int sockfd);
/**
* @brief Returns list of current socket descriptors of active sessions
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in,out] fds In: Size of provided client_fds array
* Out: Number of valid client fds returned in client_fds,
* @param[out] client_fds Array of client fds
*
* @note Size of provided array has to be equal or greater then maximum number of opened
* sockets, configured upon initialization with max_open_sockets field in
* httpd_config_t structure.
*
* @return
* - ESP_OK : Successfully retrieved session list
* - ESP_ERR_INVALID_ARG : Wrong arguments or list is longer than provided array
*/
esp_err_t httpd_get_client_list(httpd_handle_t handle, size_t *fds, int *client_fds);
/** End of Session
* @}
*/
/* ************** Group: Work Queue ************** */
/** @name Work Queue
* APIs related to the HTTPD Work Queue
* @{
*/
/**
* @brief Prototype of the HTTPD work function
* Please refer to httpd_queue_work() for more details.
* @param[in] arg The arguments for this work function
*/
typedef void (*httpd_work_fn_t)(void *arg);
/**
* @brief Queue execution of a function in HTTPD's context
*
* This API queues a work function for asynchronous execution
*
* @note Some protocols require that the web server generate some asynchronous data
* and send it to the persistently opened connection. This facility is for use
* by such protocols.
*
* @param[in] handle Handle to server returned by httpd_start
* @param[in] work Pointer to the function to be executed in the HTTPD's context
* @param[in] arg Pointer to the arguments that should be passed to this function
*
* @return
* - ESP_OK : On successfully queueing the work
* - ESP_FAIL : Failure in ctrl socket
* - ESP_ERR_INVALID_ARG : Null arguments
*/
esp_err_t httpd_queue_work(httpd_handle_t handle, httpd_work_fn_t work, void *arg);
/** End of Group Work Queue
* @}
*/
/* ************** Group: WebSocket ************** */
/** @name WebSocket
* Functions and structs for WebSocket server
* @{
*/
#ifdef CONFIG_HTTPD_WS_SUPPORT
/**
* @brief Enum for WebSocket packet types (Opcode in the header)
* @note Please refer to RFC6455 Section 5.4 for more details
*/
typedef enum {
HTTPD_WS_TYPE_CONTINUE = 0x0,
HTTPD_WS_TYPE_TEXT = 0x1,
HTTPD_WS_TYPE_BINARY = 0x2,
HTTPD_WS_TYPE_CLOSE = 0x8,
HTTPD_WS_TYPE_PING = 0x9,
HTTPD_WS_TYPE_PONG = 0xA
} httpd_ws_type_t;
/**
* @brief Enum for client info description
*/
typedef enum {
HTTPD_WS_CLIENT_INVALID = 0x0,
HTTPD_WS_CLIENT_HTTP = 0x1,
HTTPD_WS_CLIENT_WEBSOCKET = 0x2,
} httpd_ws_client_info_t;
/**
* @brief WebSocket frame format
*/
typedef struct httpd_ws_frame {
bool final; /*!< Final frame:
For received frames this field indicates whether the `FIN` flag was set.
For frames to be transmitted, this field is only used if the `fragmented`
option is set as well. If `fragmented` is false, the `FIN` flag is set
by default, marking the ws_frame as a complete/unfragmented message
(esp_http_server doesn't automatically fragment messages) */
bool fragmented; /*!< Indication that the frame allocated for transmission is a message fragment,
so the `FIN` flag is set manually according to the `final` option.
This flag is never set for received messages */
httpd_ws_type_t type; /*!< WebSocket frame type */
uint8_t *payload; /*!< Pre-allocated data buffer */
size_t len; /*!< Length of the WebSocket data */
} httpd_ws_frame_t;
/**
* @brief Transfer complete callback
*/
typedef void (*transfer_complete_cb)(esp_err_t err, int socket, void *arg);
/**
* @brief Receive and parse a WebSocket frame
*
* @note Calling httpd_ws_recv_frame() with max_len as 0 will give actual frame size in pkt->len.
* The user can dynamically allocate space for pkt->payload as per this length and call httpd_ws_recv_frame() again to get the actual data.
* Please refer to the corresponding example for usage.
*
* @param[in] req Current request
* @param[out] pkt WebSocket packet
* @param[in] max_len Maximum length for receive
* @return
* - ESP_OK : On successful
* - ESP_FAIL : Socket errors occurs
* - ESP_ERR_INVALID_STATE : Handshake was already done beforehand
* - ESP_ERR_INVALID_ARG : Argument is invalid (null or non-WebSocket)
*/
esp_err_t httpd_ws_recv_frame(httpd_req_t *req, httpd_ws_frame_t *pkt, size_t max_len);
/**
* @brief Construct and send a WebSocket frame
* @param[in] req Current request
* @param[in] pkt WebSocket frame
* @return
* - ESP_OK : On successful
* - ESP_FAIL : When socket errors occurs
* - ESP_ERR_INVALID_STATE : Handshake was already done beforehand
* - ESP_ERR_INVALID_ARG : Argument is invalid (null or non-WebSocket)
*/
esp_err_t httpd_ws_send_frame(httpd_req_t *req, httpd_ws_frame_t *pkt);
/**
* @brief Low level send of a WebSocket frame out of the scope of current request
* using internally configured httpd send function
*
* This API should rarely be called directly, with an exception of asynchronous send using httpd_queue_work.
*
* @param[in] hd Server instance data
* @param[in] fd Socket descriptor for sending data
* @param[in] frame WebSocket frame
* @return
* - ESP_OK : On successful
* - ESP_FAIL : When socket errors occurs
* - ESP_ERR_INVALID_STATE : Handshake was already done beforehand
* - ESP_ERR_INVALID_ARG : Argument is invalid (null or non-WebSocket)
*/
esp_err_t httpd_ws_send_frame_async(httpd_handle_t hd, int fd, httpd_ws_frame_t *frame);
/**
* @brief Checks the supplied socket descriptor if it belongs to any active client
* of this server instance and if the websoket protocol is active
*
* @param[in] hd Server instance data
* @param[in] fd Socket descriptor
* @return
* - HTTPD_WS_CLIENT_INVALID : This fd is not a client of this httpd
* - HTTPD_WS_CLIENT_HTTP : This fd is an active client, protocol is not WS
* - HTTPD_WS_CLIENT_WEBSOCKET : This fd is an active client, protocol is WS
*/
httpd_ws_client_info_t httpd_ws_get_fd_info(httpd_handle_t hd, int fd);
/**
* @brief Sends data to to specified websocket synchronously
*
* @param[in] handle Server instance data
* @param[in] socket Socket descriptor
* @param[in] frame Websocket frame
* @return
* - ESP_OK : On successful
* - ESP_FAIL : When socket errors occurs
* - ESP_ERR_NO_MEM : Unable to allocate memory
*/
esp_err_t httpd_ws_send_data(httpd_handle_t handle, int socket, httpd_ws_frame_t *frame);
/**
* @brief Sends data to to specified websocket asynchronously
*
* @param[in] handle Server instance data
* @param[in] socket Socket descriptor
* @param[in] frame Websocket frame
* @param[in] callback Callback invoked after sending data
* @param[in] arg User data passed to provided callback
* @return
* - ESP_OK : On successful
* - ESP_FAIL : When socket errors occurs
* - ESP_ERR_NO_MEM : Unable to allocate memory
*/
esp_err_t httpd_ws_send_data_async(httpd_handle_t handle, int socket, httpd_ws_frame_t *frame,
transfer_complete_cb callback, void *arg);
#endif /* CONFIG_HTTPD_WS_SUPPORT */
/** End of WebSocket related stuff
* @}
*/
#ifdef __cplusplus
}
#endif
#endif /* ! _ESP_HTTP_SERVER_H_ */