1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 39 #ifndef __ATT_H 40 #define __ATT_H 41 42 #include <stdint.h> 43 #include "bluetooth.h" 44 #include "btstack_linked_list.h" 45 46 #if defined __cplusplus 47 extern "C" { 48 #endif 49 50 // custom BTstack error codes 51 #define ATT_ERROR_HCI_DISCONNECT_RECEIVED 0x1f 52 53 // custom BTstack ATT error codes 54 #define ATT_ERROR_DATA_MISMATCH 0x7e 55 #define ATT_ERROR_TIMEOUT 0x7F 56 57 typedef struct att_connection { 58 hci_con_handle_t con_handle; 59 uint16_t mtu; // initialized to ATT_DEFAULT_MTU (23), negotiated during MTU exchange 60 uint16_t max_mtu; // local maximal L2CAP_MTU, set to l2cap_max_le_mtu() 61 uint8_t encryption_key_size; 62 uint8_t authenticated; 63 uint8_t authorized; 64 } att_connection_t; 65 66 // ATT Client Read Callback for Dynamic Data 67 // - if buffer == NULL, don't copy data, just return size of value 68 // - if buffer != NULL, copy data and return number bytes copied 69 // @param con_handle of hci le connection 70 // @param attribute_handle to be read 71 // @param offset defines start of attribute value 72 // @param buffer 73 // @param buffer_size 74 typedef uint16_t (*att_read_callback_t)(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 75 76 // ATT Client Write Callback for Dynamic Data 77 // @param con_handle of hci le connection 78 // @param attribute_handle to be written 79 // @param transaction - ATT_TRANSACTION_MODE_NONE for regular writes. For prepared writes: ATT_TRANSACTION_MODE_ACTIVE, ATT_TRANSACTION_MODE_VALIDATE, ATT_TRANSACTION_MODE_EXECUTE, ATT_TRANSACTION_MODE_CANCEL 80 // @param offset into the value - used for queued writes and long attributes 81 // @param buffer 82 // @param buffer_size 83 // @param signature used for signed write commmands 84 // @returns 0 if write was ok, ATT_ERROR_PREPARE_QUEUE_FULL if no space in queue, ATT_ERROR_INVALID_OFFSET if offset is larger than max buffer 85 // 86 // Each Prepared Write Request triggers a callback with transaction mode ATT_TRANSACTION_MODE_ACTIVE. 87 // On Execute Write, the callback will be called with ATT_TRANSACTION_MODE_VALIDATE and allows to validate all queued writes and return an application error. 88 // If none of the registered callbacks return an error for ATT_TRANSACTION_MODE_VALIDATE and the callback will be called with ATT_TRANSACTION_MODE_EXECUTE. 89 // Otherwise, all callbacks will be called with ATT_TRANSACTION_MODE_CANCEL. 90 // 91 // If the additional validation step is not needed, just return 0 for all callbacks with transaction mode ATT_TRANSACTION_MODE_VALIDATE. 92 // 93 typedef int (*att_write_callback_t)(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size); 94 95 // Read & Write Callbacks for handle range 96 typedef struct att_service_handler { 97 btstack_linked_item_t * item; 98 uint16_t start_handle; 99 uint16_t end_handle; 100 att_read_callback_t read_callback; 101 att_write_callback_t write_callback; 102 } att_service_handler_t; 103 104 // MARK: ATT Operations 105 106 /* 107 * @brief setup ATT database 108 */ 109 void att_set_db(uint8_t const * db); 110 111 /* 112 * @brief set callback for read of dynamic attributes 113 * @param callback 114 */ 115 void att_set_read_callback(att_read_callback_t callback); 116 117 /* 118 * @brief set callback for write of dynamic attributes 119 * @param callback 120 */ 121 void att_set_write_callback(att_write_callback_t callback); 122 123 /* 124 * @brief debug helper, dump ATT database to stdout using log_info 125 */ 126 void att_dump_attributes(void); 127 128 /* 129 * @brief process ATT request against database and put response into response buffer 130 * @param att_connection used for mtu and security properties 131 * @param request_buffer, request_len: ATT request from clinet 132 * @param response_buffer for result 133 * @returns len of data in response buffer. 0 = no response 134 */ 135 uint16_t att_handle_request(att_connection_t * att_connection, 136 uint8_t * request_buffer, 137 uint16_t request_len, 138 uint8_t * response_buffer); 139 140 /* 141 * @brief setup value notification in response buffer for a given handle and value 142 * @param att_connection 143 * @param attribute_handle 144 * @param value 145 * @param value_len 146 * @param response_buffer for notification 147 */ 148 uint16_t att_prepare_handle_value_notification(att_connection_t * att_connection, 149 uint16_t attribute_handle, 150 uint8_t *value, 151 uint16_t value_len, 152 uint8_t * response_buffer); 153 154 /* 155 * @brief setup value indication in response buffer for a given handle and value 156 * @param att_connection 157 * @param attribute_handle 158 * @param value 159 * @param value_len 160 * @param response_buffer for indication 161 */ 162 uint16_t att_prepare_handle_value_indication(att_connection_t * att_connection, 163 uint16_t attribute_handle, 164 uint8_t *value, 165 uint16_t value_len, 166 uint8_t * response_buffer); 167 168 /* 169 * @brief transcation queue of prepared writes, e.g., after disconnect 170 */ 171 void att_clear_transaction_queue(att_connection_t * att_connection); 172 173 // att_read_callback helpers for a various data types 174 175 /* 176 * @brief Handle read of blob like data for att_read_callback 177 * @param blob of data 178 * @param blob_size of blob 179 * @param offset from att_read_callback 180 * @param buffer from att_read_callback 181 * @param buffer_size from att_read_callback 182 * @returns value size for buffer == 0 and num bytes copied otherwise 183 */ 184 uint16_t att_read_callback_handle_blob(const uint8_t * blob, uint16_t blob_size, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 185 186 /* 187 * @brief Handle read of little endian unsigned 32 bit value for att_read_callback 188 * @param value 189 * @param offset from att_read_callback 190 * @param buffer from att_read_callback 191 * @param buffer_size from att_read_callback 192 * @returns value size for buffer == 0 and num bytes copied otherwise 193 */ 194 uint16_t att_read_callback_handle_little_endian_32(uint32_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 195 196 /* 197 * @brief Handle read of little endian unsigned 16 bit value for att_read_callback 198 * @param value 199 * @param offset from att_read_callback 200 * @param buffer from att_read_callback 201 * @param buffer_size from att_read_callback 202 * @returns value size for buffer == 0 and num bytes copied otherwise 203 */ 204 uint16_t att_read_callback_handle_little_endian_16(uint16_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 205 206 /* 207 * @brief Handle read of single byte for att_read_callback 208 * @param blob of data 209 * @param blob_size of blob 210 * @param offset from att_read_callback 211 * @param buffer from att_read_callback 212 * @param buffer_size from att_read_callback 213 * @returns value size for buffer == 0 and num bytes copied otherwise 214 */ 215 uint16_t att_read_callback_handle_byte(uint8_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 216 217 218 // experimental client API 219 uint16_t att_uuid_for_handle(uint16_t attribute_handle); 220 221 222 // experimental GATT Server API 223 224 // returns 1 if service found. only primary service. 225 int gatt_server_get_get_handle_range_for_service_with_uuid16(uint16_t uuid16, uint16_t * start_handle, uint16_t * end_handle); 226 227 // returns 0 if not found 228 uint16_t gatt_server_get_value_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16); 229 230 // returns 0 if not found 231 uint16_t gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16); 232 233 // non-user functionality for att_server 234 235 /* 236 * @brief Check if writes to handle should be persistent 237 * @param handle 238 * @returns 1 if persistent 239 */ 240 int att_is_persistent_ccc(uint16_t handle); 241 242 243 #if defined __cplusplus 244 } 245 #endif 246 247 #endif // __ATT_H 248