// Copyright 2017 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 __ESP_EXAMPLE_SH2_LIB_H_ #define __ESP_EXAMPLE_SH2_LIB_H_ #include #include /* * This is a thin API wrapper over nghttp2 that offers simplified APIs for usage * in the application. The intention of this wrapper is to act as a stepping * stone to quickly get started with using the HTTP/2 client. Since the focus is * on simplicity, not all the features of HTTP/2 are supported through this * wrapper. Once you are fairly comfortable with nghttp2, feel free to directly * use nghttp2 APIs or make changes to sh2lib.c for realising your objectives. * * TODO: * - Allowing to query response code, content-type etc in the receive callback * - A simple function for per-stream header callback */ /** * @brief Handle for working with sh2lib APIs */ struct sh2lib_handle { /* Ideally, CTX is per-program, so we could potentially take it out of this * per-connection structure */ SSL_CTX *ssl_ctx; /*!< Pointer to the SSL context */ SSL *ssl; /*!< Pointer to the SSL handle */ nghttp2_session *http2_sess; /*!< Pointer to the HTTP2 session handle */ int sockfd; /*!< Socket file descriptor */ char *hostname; /*!< The hostname we are connected to */ }; /** Flag indicating receive stream is reset */ #define DATA_RECV_RST_STREAM 1 /** Flag indicating frame is completely received */ #define DATA_RECV_FRAME_COMPLETE 2 /** * @brief Function Prototype for data receive callback * * This function gets called whenever data is received on any stream. The * function is also called for indicating events like frame receive complete, or * end of stream. The function may get called multiple times as long as data is * received on the stream. * * @param[in] handle Pointer to the sh2lib handle. * @param[in] data Pointer to a buffer that contains the data received. * @param[in] len The length of valid data stored at the 'data' pointer. * @param[in] flags Flags indicating whether the stream is reset (DATA_RECV_RST_STREAM) or * this particularly frame is completely received * DATA_RECV_FRAME_COMPLETE). * * @return The function should return 0 */ typedef int (*sh2lib_frame_data_recv_cb_t)(struct sh2lib_handle *handle, const char *data, size_t len, int flags); /** * @brief Function Prototype for callback to send data in PUT/POST * * This function gets called whenever nghttp2 wishes to send data, like for * PUT/POST requests to the server. The function keeps getting called until this * function sets the flag NGHTTP2_DATA_FLAG_EOF to indicate end of data. * * @param[in] handle Pointer to the sh2lib handle. * @param[out] data Pointer to a buffer that should contain the data to send. * @param[in] len The maximum length of data that can be sent out by this function. * @param[out] data_flags Pointer to the data flags. The NGHTTP2_DATA_FLAG_EOF * should be set in the data flags to indicate end of new data. * * @return The function should return the number of valid bytes stored in the * data pointer */ typedef int (*sh2lib_putpost_data_cb_t)(struct sh2lib_handle *handle, char *data, size_t len, uint32_t *data_flags); /** * @brief Connect to a URI using HTTP/2 * * This API opens an HTTP/2 connection with the provided URI. If successful, the * hd pointer is populated with a valid handle for subsequent communication. * * Only 'https' URIs are supported. * * @param[out] hd Pointer to a variable of the type 'struct sh2lib_handle'. * @param[in] uri Pointer to the URI that should be connected to. * * @return * - ESP_OK if the connection was successful * - ESP_FAIL if the connection fails */ int sh2lib_connect(struct sh2lib_handle *hd, const char *uri); /** * @brief Free a sh2lib handle * * This API frees-up an sh2lib handle, thus closing any open connections that * may be associated with this handle, and freeing up any resources. * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle'. * */ void sh2lib_free(struct sh2lib_handle *hd); /** * @brief Setup an HTTP GET request stream * * This API sets up an HTTP GET request to be sent out to the server. A new * stream is created for handling the request. Once the request is setup, the * API sh2lib_execute() must be called to actually perform the socket I/O with * the server. * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle'. * @param[in] path Pointer to the string that contains the resource to * perform the HTTP GET operation on (for example, /users). * @param[in] recv_cb The callback function that should be called for * processing the request's response * * @return * - ESP_OK if request setup is successful * - ESP_FAIL if the request setup fails */ int sh2lib_do_get(struct sh2lib_handle *hd, const char *path, sh2lib_frame_data_recv_cb_t recv_cb); /** * @brief Setup an HTTP POST request stream * * This API sets up an HTTP POST request to be sent out to the server. A new * stream is created for handling the request. Once the request is setup, the * API sh2lib_execute() must be called to actually perform the socket I/O with * the server. * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle'. * @param[in] path Pointer to the string that contains the resource to * perform the HTTP POST operation on (for example, /users). * @param[in] send_cb The callback function that should be called for * sending data as part of this request. * @param[in] recv_cb The callback function that should be called for * processing the request's response * * @return * - ESP_OK if request setup is successful * - ESP_FAIL if the request setup fails */ int sh2lib_do_post(struct sh2lib_handle *hd, const char *path, sh2lib_putpost_data_cb_t send_cb, sh2lib_frame_data_recv_cb_t recv_cb); /** * @brief Setup an HTTP PUT request stream * * This API sets up an HTTP PUT request to be sent out to the server. A new * stream is created for handling the request. Once the request is setup, the * API sh2lib_execute() must be called to actually perform the socket I/O with * the server. * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle'. * @param[in] path Pointer to the string that contains the resource to * perform the HTTP PUT operation on (for example, /users). * @param[in] send_cb The callback function that should be called for * sending data as part of this request. * @param[in] recv_cb The callback function that should be called for * processing the request's response * * @return * - ESP_OK if request setup is successful * - ESP_FAIL if the request setup fails */ int sh2lib_do_put(struct sh2lib_handle *hd, const char *path, sh2lib_putpost_data_cb_t send_cb, sh2lib_frame_data_recv_cb_t recv_cb); /** * @brief Execute send/receive on an HTTP/2 connection * * While the API sh2lib_do_get(), sh2lib_do_post() setup the requests to be * initiated with the server, this API performs the actual data send/receive * operations on the HTTP/2 connection. The callback functions are accordingly * called during the processing of these requests. * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle' * * @return * - ESP_OK if the connection was successful * - ESP_FAIL if the connection fails */ int sh2lib_execute(struct sh2lib_handle *hd); #define SH2LIB_MAKE_NV(NAME, VALUE) \ { \ (uint8_t *)NAME, (uint8_t *)VALUE, strlen(NAME), strlen(VALUE), \ NGHTTP2_NV_FLAG_NONE \ } /** * @brief Setup an HTTP GET request stream with custom name-value pairs * * For a simpler version of the API, please refer to sh2lib_do_get(). * * This API sets up an HTTP GET request to be sent out to the server. A new * stream is created for handling the request. Once the request is setup, the * API sh2lib_execute() must be called to actually perform the socket I/O with * the server. * * Please note that the following name value pairs MUST be a part of the request * - name:value * - ":method":"GET" * - ":scheme":"https" * - ":path": (for example, /users) * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle'. * @param[in] nva An array of name-value pairs that should be part of the request. * @param[in] nvlen The number of elements in the array pointed to by 'nva'. * @param[in] recv_cb The callback function that should be called for * processing the request's response * * @return * - ESP_OK if request setup is successful * - ESP_FAIL if the request setup fails */ int sh2lib_do_get_with_nv(struct sh2lib_handle *hd, const nghttp2_nv *nva, size_t nvlen, sh2lib_frame_data_recv_cb_t recv_cb); /** * @brief Setup an HTTP PUT/POST request stream with custom name-value pairs * * For a simpler version of the API, please refer to sh2lib_do_put() or * sh2lib_do_post(). * * This API sets up an HTTP PUT/POST request to be sent out to the server. A new * stream is created for handling the request. Once the request is setup, the * API sh2lib_execute() must be called to actually perform the socket I/O with * the server. * * Please note that the following name value pairs MUST be a part of the request * - name:value * - ":method":"PUT" (or POST) * - ":scheme":"https" * - ":path": (for example, /users) * * @param[in] hd Pointer to a variable of the type 'struct sh2lib_handle'. * @param[in] nva An array of name-value pairs that should be part of the request. * @param[in] nvlen The number of elements in the array pointed to by 'nva'. * @param[in] send_cb The callback function that should be called for * sending data as part of this request. * @param[in] recv_cb The callback function that should be called for * processing the request's response * * @return * - ESP_OK if request setup is successful * - ESP_FAIL if the request setup fails */ int sh2lib_do_putpost_with_nv(struct sh2lib_handle *hd, const nghttp2_nv *nva, size_t nvlen, sh2lib_putpost_data_cb_t send_cb, sh2lib_frame_data_recv_cb_t recv_cb); #endif /* ! __ESP_EXAMPLE_SH2_LIB_H_ */