xref: /btstack/src/ble/att_db.h (revision 1b2596b5303dd8caeea8565532c93cca8dab8cc4)
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, ATT_TRANSACTION_MODE_ACTIVE for prepared writes and ATT_TRANSACTION_MODE_EXECUTE
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 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);
86 
87 
88 // Read & Write Callbacks for handle range
89 typedef struct att_service_handler {
90   btstack_linked_item_t * item;
91   uint16_t start_handle;
92   uint16_t end_handle;
93   att_read_callback_t read_callback;
94   att_write_callback_t write_callback;
95 } att_service_handler_t;
96 
97 // MARK: ATT Operations
98 
99 /*
100  * @brief setup ATT database
101  */
102 void att_set_db(uint8_t const * db);
103 
104 /*
105  * @brief set callback for read of dynamic attributes
106  * @param callback
107  */
108 void att_set_read_callback(att_read_callback_t callback);
109 
110 /*
111  * @brief set callback for write of dynamic attributes
112  * @param callback
113  */
114 void att_set_write_callback(att_write_callback_t callback);
115 
116 /*
117  * @brief debug helper, dump ATT database to stdout using log_info
118  */
119 void att_dump_attributes(void);
120 
121 /*
122  * @brief process ATT request against database and put response into response buffer
123  * @param att_connection used for mtu and security properties
124  * @param request_buffer, request_len: ATT request from clinet
125  * @param response_buffer for result
126  * @returns len of data in response buffer. 0 = no response
127  */
128 uint16_t att_handle_request(att_connection_t * att_connection,
129                             uint8_t * request_buffer,
130                             uint16_t request_len,
131                             uint8_t * response_buffer);
132 
133 /*
134  * @brief setup value notification in response buffer for a given handle and value
135  * @param att_connection
136  * @param attribute_handle
137  * @param value
138  * @param value_len
139  * @param response_buffer for notification
140  */
141 uint16_t att_prepare_handle_value_notification(att_connection_t * att_connection,
142                                                uint16_t attribute_handle,
143                                                uint8_t *value,
144                                                uint16_t value_len,
145                                                uint8_t * response_buffer);
146 
147 /*
148  * @brief setup value indication in response buffer for a given handle and value
149  * @param att_connection
150  * @param attribute_handle
151  * @param value
152  * @param value_len
153  * @param response_buffer for indication
154  */
155 uint16_t att_prepare_handle_value_indication(att_connection_t * att_connection,
156                                              uint16_t attribute_handle,
157                                              uint8_t *value,
158                                              uint16_t value_len,
159                                              uint8_t * response_buffer);
160 
161 /*
162  * @brief transcation queue of prepared writes, e.g., after disconnect
163  */
164 void att_clear_transaction_queue(att_connection_t * att_connection);
165 
166 /**
167  * @brief register read/write callbacks for specific handle range
168  * @param att_service_handler_t
169  */
170 void att_register_service_handler(att_service_handler_t * handler);
171 
172 
173  // experimental client API
174 uint16_t att_uuid_for_handle(uint16_t attribute_handle);
175 
176 
177 // experimental GATT Server API
178 
179 // returns 1 if service found. only primary service.
180 int gatt_server_get_get_handle_range_for_service_with_uuid16(uint16_t uuid16, uint16_t * start_handle, uint16_t * end_handle);
181 
182 // returns 0 if not found
183 uint16_t gatt_server_get_value_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16);
184 
185 // returns 0 if not found
186 uint16_t gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(uint16_t start_handle, uint16_t end_handle, uint16_t uuid16);
187 
188 #if defined __cplusplus
189 }
190 #endif
191 
192 #endif // __ATT_H
193