xref: /btstack/src/ble/att_db.h (revision 3c4cc6427fe05577c00b7d2593f58c7abcf9eab7)
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
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33  * Please inquire about commercial licensing options at
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36  */
37 
38 
39 #ifndef ATT_DB_H
40 #define ATT_DB_H
41 
42 #include <stdint.h>
43 #include "bluetooth.h"
44 #include "btstack_linked_list.h"
45 #include "btstack_defines.h"
46 
47 #if defined __cplusplus
48 extern "C" {
49 #endif
50 
51 // custom BTstack error codes
52 #define ATT_ERROR_HCI_DISCONNECT_RECEIVED         0x1f
53 
54 // custom BTstack ATT error codes
55 #define ATT_ERROR_DATA_MISMATCH                   0x7e
56 #define ATT_ERROR_TIMEOUT                         0x7F
57 #define ATT_ERROR_WRITE_RESPONSE_PENDING         0x100
58 
59 // custom BTstack ATT Response Pending for att_read_callback
60 #define ATT_READ_RESPONSE_PENDING                 0xffff
61 
62 // internally used to signal write response pending
63 #define ATT_INTERNAL_WRITE_RESPONSE_PENDING       0xfffe
64 
65 typedef struct att_connection {
66     hci_con_handle_t con_handle;
67     uint16_t mtu;       // initialized to ATT_DEFAULT_MTU (23), negotiated during MTU exchange
68     uint16_t max_mtu;   // local maximal L2CAP_MTU, set to l2cap_max_le_mtu()
69     uint8_t  encryption_key_size;
70     uint8_t  authenticated;
71     uint8_t  authorized;
72     uint8_t  secure_connection;
73 } att_connection_t;
74 
75 // ATT Client Read Callback for Dynamic Data
76 // - if buffer == NULL, don't copy data, just return size of value
77 // - if buffer != NULL, copy data and return number bytes copied
78 // If ENABLE_ATT_DELAYED_READ_RESPONSE is defined, you may return ATT_READ_RESPONSE_PENDING if data isn't available yet
79 // @param con_handle of hci le connection
80 // @param attribute_handle to be read
81 // @param offset defines start of attribute value
82 // @param buffer
83 // @param buffer_size
84 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);
85 
86 // ATT Client Write Callback for Dynamic Data
87 // @param con_handle of hci le connection
88 // @param attribute_handle to be written
89 // @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
90 // @param offset into the value - used for queued writes and long attributes
91 // @param buffer
92 // @param buffer_size
93 // @param signature used for signed write commmands
94 // @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
95 //
96 // Each Prepared Write Request triggers a callback with transaction mode ATT_TRANSACTION_MODE_ACTIVE.
97 // 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.
98 // 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.
99 // Otherwise, all callbacks will be called with ATT_TRANSACTION_MODE_CANCEL.
100 //
101 // If the additional validation step is not needed, just return 0 for all callbacks with transaction mode ATT_TRANSACTION_MODE_VALIDATE.
102 //
103 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);
104 
105 // Read & Write Callbacks for handle range
106 typedef struct att_service_handler {
107     btstack_linked_item_t * item;
108     uint16_t start_handle;
109     uint16_t end_handle;
110     att_read_callback_t read_callback;
111     att_write_callback_t write_callback;
112     btstack_packet_handler_t packet_handler;
113 } att_service_handler_t;
114 
115 // MARK: ATT Operations
116 
117 /*
118  * @brief setup ATT database
119  */
120 void att_set_db(uint8_t const * db);
121 
122 /*
123  * @brief set callback for read of dynamic attributes
124  * @param callback
125  */
126 void att_set_read_callback(att_read_callback_t callback);
127 
128 /*
129  * @brief set callback for write of dynamic attributes
130  * @param callback
131  */
132 void att_set_write_callback(att_write_callback_t callback);
133 
134 /*
135  * @brief debug helper, dump ATT database to stdout using log_info
136  */
137 void att_dump_attributes(void);
138 
139 /*
140  * @brief process ATT request against database and put response into response buffer
141  * @param att_connection used for mtu and security properties
142  * @param request_buffer, request_len: ATT request from clinet
143  * @param response_buffer for result
144  * @returns len of data in response buffer. 0 = no response,
145  *          ATT_READ_RESPONSE_PENDING if it was returned at least once for dynamic data (requires ENABLE_ATT_DELAYED_READ_RESPONSE)
146  */
147 uint16_t att_handle_request(att_connection_t * att_connection,
148                             uint8_t * request_buffer,
149                             uint16_t request_len,
150                             uint8_t * response_buffer);
151 
152 /*
153  * @brief setup value notification in response buffer for a given handle and value
154  * @param att_connection
155  * @param attribute_handle
156  * @param value
157  * @param value_len
158  * @param response_buffer for notification
159  */
160 uint16_t att_prepare_handle_value_notification(att_connection_t * att_connection,
161                                                uint16_t attribute_handle,
162                                                const uint8_t *value,
163                                                uint16_t value_len,
164                                                uint8_t * response_buffer);
165 
166 /*
167  * @brief setup value indication in response buffer for a given handle and value
168  * @param att_connection
169  * @param attribute_handle
170  * @param value
171  * @param value_len
172  * @param response_buffer for indication
173  */
174 uint16_t att_prepare_handle_value_indication(att_connection_t * att_connection,
175                                              uint16_t attribute_handle,
176                                              const uint8_t *value,
177                                              uint16_t value_len,
178                                              uint8_t * response_buffer);
179 
180 /*
181  * @brief transcation queue of prepared writes, e.g., after disconnect
182  */
183 void att_clear_transaction_queue(att_connection_t * att_connection);
184 
185 // att_read_callback helpers for a various data types
186 
187 /*
188  * @brief Handle read of blob like data for att_read_callback
189  * @param blob of data
190  * @param blob_size of blob
191  * @param offset from att_read_callback
192  * @param buffer from att_read_callback
193  * @param buffer_size from att_read_callback
194  * @returns value size for buffer == 0 and num bytes copied otherwise
195  */
196 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);
197 
198 /*
199  * @brief Handle read of little endian unsigned 32 bit value for att_read_callback
200  * @param value
201  * @param offset from att_read_callback
202  * @param buffer from att_read_callback
203  * @param buffer_size from att_read_callback
204  * @returns value size for buffer == 0 and num bytes copied otherwise
205  */
206 uint16_t att_read_callback_handle_little_endian_32(uint32_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size);
207 
208 /*
209  * @brief Handle read of little endian unsigned 16 bit value for att_read_callback
210  * @param value
211  * @param offset from att_read_callback
212  * @param buffer from att_read_callback
213  * @param buffer_size from att_read_callback
214  * @returns value size for buffer == 0 and num bytes copied otherwise
215  */
216 uint16_t att_read_callback_handle_little_endian_16(uint16_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size);
217 
218 /*
219  * @brief Handle read of single byte for att_read_callback
220  * @param blob of data
221  * @param blob_size of blob
222  * @param offset from att_read_callback
223  * @param buffer from att_read_callback
224  * @param buffer_size from att_read_callback
225  * @returns value size for buffer == 0 and num bytes copied otherwise
226  */
227 uint16_t att_read_callback_handle_byte(uint8_t value, uint16_t offset, uint8_t * buffer, uint16_t buffer_size);
228 
229 
230 // experimental client API
231 uint16_t att_uuid_for_handle(uint16_t attribute_handle);
232 
233 
234 // experimental GATT Server API
235 
236 // returns 1 if service found. only primary service.
237 int gatt_server_get_get_handle_range_for_service_with_uuid16(uint16_t uuid16, uint16_t * start_handle, uint16_t * end_handle);
238 
239 // returns 0 if not found
240 uint16_t gatt_server_get_value_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16);
241 
242 // returns 0 if not found
243 uint16_t gatt_server_get_descriptor_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t characteristic_uuid16, uint16_t descriptor_uuid16);
244 uint16_t gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t characteristic_uuid16);
245 uint16_t gatt_server_get_server_configuration_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t characteristic_uuid16);
246 
247 
248 // returns 1 if service found. only primary service.
249 int gatt_server_get_get_handle_range_for_service_with_uuid128(const uint8_t * uuid128, uint16_t * start_handle, uint16_t * end_handle);
250 
251 // returns 0 if not found
252 uint16_t gatt_server_get_value_handle_for_characteristic_with_uuid128(uint16_t start_handle, uint16_t end_handle, const uint8_t * uuid128);
253 
254 // returns 0 if not found
255 uint16_t gatt_server_get_client_configuration_handle_for_characteristic_with_uuid128(uint16_t start_handle, uint16_t end_handle, const uint8_t * uuid128);
256 
257 // non-user functionality for att_server
258 
259 /*
260  * @brief Check if writes to handle should be persistent
261  * @param handle
262  * @returns 1 if persistent
263  */
264 int att_is_persistent_ccc(uint16_t handle);
265 
266 
267 #if defined __cplusplus
268 }
269 #endif
270 
271 #endif // ATT_H
272