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 // custom BTstack ATT Response Pending 58 #define ATT_READ_RESPONSE_PENDING 0xffff 59 60 typedef struct att_connection { 61 hci_con_handle_t con_handle; 62 uint16_t mtu; // initialized to ATT_DEFAULT_MTU (23), negotiated during MTU exchange 63 uint16_t max_mtu; // local maximal L2CAP_MTU, set to l2cap_max_le_mtu() 64 uint8_t encryption_key_size; 65 uint8_t authenticated; 66 uint8_t authorized; 67 } att_connection_t; 68 69 // ATT Client Read Callback for Dynamic Data 70 // - if buffer == NULL, don't copy data, just return size of value 71 // - if buffer != NULL, copy data and return number bytes copied 72 // If ENABLE_ATT_DELAYED_READ_RESPONSE is defined, you may return ATT_READ_RESPONSE_PENDING if data isn't available yet 73 // @param con_handle of hci le connection 74 // @param attribute_handle to be read 75 // @param offset defines start of attribute value 76 // @param buffer 77 // @param buffer_size 78 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); 79 80 // ATT Client Write Callback for Dynamic Data 81 // @param con_handle of hci le connection 82 // @param attribute_handle to be written 83 // @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 84 // @param offset into the value - used for queued writes and long attributes 85 // @param buffer 86 // @param buffer_size 87 // @param signature used for signed write commmands 88 // @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 89 // 90 // Each Prepared Write Request triggers a callback with transaction mode ATT_TRANSACTION_MODE_ACTIVE. 91 // 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. 92 // 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. 93 // Otherwise, all callbacks will be called with ATT_TRANSACTION_MODE_CANCEL. 94 // 95 // If the additional validation step is not needed, just return 0 for all callbacks with transaction mode ATT_TRANSACTION_MODE_VALIDATE. 96 // 97 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); 98 99 // Read & Write Callbacks for handle range 100 typedef struct att_service_handler { 101 btstack_linked_item_t * item; 102 uint16_t start_handle; 103 uint16_t end_handle; 104 att_read_callback_t read_callback; 105 att_write_callback_t write_callback; 106 } att_service_handler_t; 107 108 // MARK: ATT Operations 109 110 /* 111 * @brief setup ATT database 112 */ 113 void att_set_db(uint8_t const * db); 114 115 /* 116 * @brief set callback for read of dynamic attributes 117 * @param callback 118 */ 119 void att_set_read_callback(att_read_callback_t callback); 120 121 /* 122 * @brief set callback for write of dynamic attributes 123 * @param callback 124 */ 125 void att_set_write_callback(att_write_callback_t callback); 126 127 /* 128 * @brief debug helper, dump ATT database to stdout using log_info 129 */ 130 void att_dump_attributes(void); 131 132 /* 133 * @brief process ATT request against database and put response into response buffer 134 * @param att_connection used for mtu and security properties 135 * @param request_buffer, request_len: ATT request from clinet 136 * @param response_buffer for result 137 * @returns len of data in response buffer. 0 = no response, 138 * ATT_READ_RESPONSE_PENDING if it was returned at least once for dynamic data (requires ENABLE_ATT_DELAYED_READ_RESPONSE) 139 */ 140 uint16_t att_handle_request(att_connection_t * att_connection, 141 uint8_t * request_buffer, 142 uint16_t request_len, 143 uint8_t * response_buffer); 144 145 /* 146 * @brief setup value notification in response buffer for a given handle and value 147 * @param att_connection 148 * @param attribute_handle 149 * @param value 150 * @param value_len 151 * @param response_buffer for notification 152 */ 153 uint16_t att_prepare_handle_value_notification(att_connection_t * att_connection, 154 uint16_t attribute_handle, 155 uint8_t *value, 156 uint16_t value_len, 157 uint8_t * response_buffer); 158 159 /* 160 * @brief setup value indication in response buffer for a given handle and value 161 * @param att_connection 162 * @param attribute_handle 163 * @param value 164 * @param value_len 165 * @param response_buffer for indication 166 */ 167 uint16_t att_prepare_handle_value_indication(att_connection_t * att_connection, 168 uint16_t attribute_handle, 169 uint8_t *value, 170 uint16_t value_len, 171 uint8_t * response_buffer); 172 173 /* 174 * @brief transcation queue of prepared writes, e.g., after disconnect 175 */ 176 void att_clear_transaction_queue(att_connection_t * att_connection); 177 178 // att_read_callback helpers for a various data types 179 180 /* 181 * @brief Handle read of blob like data for att_read_callback 182 * @param blob of data 183 * @param blob_size of blob 184 * @param offset from att_read_callback 185 * @param buffer from att_read_callback 186 * @param buffer_size from att_read_callback 187 * @returns value size for buffer == 0 and num bytes copied otherwise 188 */ 189 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); 190 191 /* 192 * @brief Handle read of little endian unsigned 32 bit value for att_read_callback 193 * @param value 194 * @param offset from att_read_callback 195 * @param buffer from att_read_callback 196 * @param buffer_size from att_read_callback 197 * @returns value size for buffer == 0 and num bytes copied otherwise 198 */ 199 uint16_t att_read_callback_handle_little_endian_32(uint32_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 200 201 /* 202 * @brief Handle read of little endian unsigned 16 bit value for att_read_callback 203 * @param value 204 * @param offset from att_read_callback 205 * @param buffer from att_read_callback 206 * @param buffer_size from att_read_callback 207 * @returns value size for buffer == 0 and num bytes copied otherwise 208 */ 209 uint16_t att_read_callback_handle_little_endian_16(uint16_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 210 211 /* 212 * @brief Handle read of single byte for att_read_callback 213 * @param blob of data 214 * @param blob_size of blob 215 * @param offset from att_read_callback 216 * @param buffer from att_read_callback 217 * @param buffer_size from att_read_callback 218 * @returns value size for buffer == 0 and num bytes copied otherwise 219 */ 220 uint16_t att_read_callback_handle_byte(uint8_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size); 221 222 223 // experimental client API 224 uint16_t att_uuid_for_handle(uint16_t attribute_handle); 225 226 227 // experimental GATT Server API 228 229 // returns 1 if service found. only primary service. 230 int gatt_server_get_get_handle_range_for_service_with_uuid16(uint16_t uuid16, uint16_t * start_handle, uint16_t * end_handle); 231 232 // returns 0 if not found 233 uint16_t gatt_server_get_value_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16); 234 235 // returns 0 if not found 236 uint16_t gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16); 237 238 // non-user functionality for att_server 239 240 /* 241 * @brief Check if writes to handle should be persistent 242 * @param handle 243 * @returns 1 if persistent 244 */ 245 int att_is_persistent_ccc(uint16_t handle); 246 247 248 #if defined __cplusplus 249 } 250 #endif 251 252 #endif // __ATT_H 253