xref: /btstack/example/gatt_streamer_server.c (revision ce6f85e79d1d141c1b45dfa16b2671762457cbb4)
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 BLUEKITCHEN
24  * GMBH 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 #define BTSTACK_FILE__ "gatt_streamer_server.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(gatt_streamer_server): Performance - Stream Data over GATT (Server)
42  *
43  * @text All newer operating systems provide GATT Client functionality.
44  * This example shows how to get a maximal throughput via BLE:
45  * - send whenever possible,
46  * - use the max ATT MTU.
47  *
48  * @text In theory, we should also update the connection parameters, but we already get
49  * a connection interval of 30 ms and there's no public way to use a shorter
50  * interval with iOS (if we're not implementing an HID device).
51  *
52  * @text Note: To start the streaming, run the example.
53  * On remote device use some GATT Explorer, e.g. LightBlue, BLExplr to enable notifications.
54  */
55  // *****************************************************************************
56 
57 #include <inttypes.h>
58 #include <stdint.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 
63 #include "btstack.h"
64 
65 // le_streamer.gatt contains the declaration of the provided GATT Services + Characteristics
66 // le_streamer.h    contains the binary representation of le_streamer.gatt
67 // it is generated by the build system by calling: $BTSTACK_ROOT/tool/compile_gatt.py le_streamer.gatt le_streamer.h
68 // it needs to be regenerated when the GATT Database declared in le_streamer.gatt file is modified
69 #include "gatt_streamer_server.h"
70 
71 #define REPORT_INTERVAL_MS 3000
72 #define MAX_NR_CONNECTIONS 3
73 
74 
75 static void  hci_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
76 static void  att_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
77 static int   att_write_callback(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size);
78 static void  streamer(void);
79 
80 // Flags general discoverable, BR/EDR supported (== not supported flag not set) when ENABLE_GATT_OVER_CLASSIC is enabled
81 #ifdef ENABLE_GATT_OVER_CLASSIC
82 #define APP_AD_FLAGS 0x02
83 #else
84 #define APP_AD_FLAGS 0x06
85 #endif
86 
87 const uint8_t adv_data[] = {
88     // Flags general discoverable
89     0x02, BLUETOOTH_DATA_TYPE_FLAGS, APP_AD_FLAGS,
90     // Name
91     0x0c, BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME, 'L', 'E', ' ', 'S', 't', 'r', 'e', 'a', 'm', 'e', 'r',
92     // Incomplete List of 16-bit Service Class UUIDs -- FF10 - only valid for testing!
93     0x03, BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS, 0x10, 0xff,
94 };
95 const uint8_t adv_data_len = sizeof(adv_data);
96 
97 static btstack_packet_callback_registration_t hci_event_callback_registration;
98 
99 // support for multiple clients
100 typedef struct {
101     char name;
102     int le_notification_enabled;
103     uint16_t value_handle;
104     hci_con_handle_t connection_handle;
105     int  counter;
106     char test_data[200];
107     int  test_data_len;
108     uint32_t test_data_sent;
109     uint32_t test_data_start;
110 } le_streamer_connection_t;
111 static le_streamer_connection_t le_streamer_connections[MAX_NR_CONNECTIONS];
112 
113 // round robin sending
114 static int connection_index;
115 
116 #ifdef ENABLE_GATT_OVER_CLASSIC
117 static uint8_t gatt_service_buffer[70];
118 #endif
119 
120 static void init_connections(void){
121     // track connections
122     int i;
123     for (i=0;i<MAX_NR_CONNECTIONS;i++){
124         le_streamer_connections[i].connection_handle = HCI_CON_HANDLE_INVALID;
125         le_streamer_connections[i].name = 'A' + i;
126     }
127 }
128 
129 static le_streamer_connection_t * connection_for_conn_handle(hci_con_handle_t conn_handle){
130     int i;
131     for (i=0;i<MAX_NR_CONNECTIONS;i++){
132         if (le_streamer_connections[i].connection_handle == conn_handle) return &le_streamer_connections[i];
133     }
134     return NULL;
135 }
136 
137 static void next_connection_index(void){
138     connection_index++;
139     if (connection_index == MAX_NR_CONNECTIONS){
140         connection_index = 0;
141     }
142 }
143 
144 /* @section Main Application Setup
145  *
146  * @text Listing MainConfiguration shows main application code.
147  * It initializes L2CAP, the Security Manager, and configures the ATT Server with the pre-compiled
148  * ATT Database generated from $le_streamer.gatt$. Finally, it configures the advertisements
149  * and boots the Bluetooth stack.
150  */
151 
152 /* LISTING_START(MainConfiguration): Init L2CAP, SM, ATT Server, and enable advertisements */
153 
154 static void le_streamer_setup(void){
155 
156     l2cap_init();
157 
158     // setup SM: Display only
159     sm_init();
160 
161 #ifdef ENABLE_GATT_OVER_CLASSIC
162     // init SDP, create record for GATT and register with SDP
163     sdp_init();
164     memset(gatt_service_buffer, 0, sizeof(gatt_service_buffer));
165     gatt_create_sdp_record(gatt_service_buffer, 0x10001, ATT_SERVICE_GATT_SERVICE_START_HANDLE, ATT_SERVICE_GATT_SERVICE_END_HANDLE);
166     sdp_register_service(gatt_service_buffer);
167     printf("SDP service record size: %u\n", de_get_len(gatt_service_buffer));
168 
169     // configure Classic GAP
170     gap_set_local_name("GATT Streamer BR/EDR 00:00:00:00:00:00");
171     gap_ssp_set_io_capability(SSP_IO_CAPABILITY_DISPLAY_YES_NO);
172     gap_discoverable_control(1);
173 #endif
174 
175     // setup ATT server
176     att_server_init(profile_data, NULL, att_write_callback);
177 
178     // register for HCI events
179     hci_event_callback_registration.callback = &hci_packet_handler;
180     hci_add_event_handler(&hci_event_callback_registration);
181 
182     // register for ATT events
183     att_server_register_packet_handler(att_packet_handler);
184 
185     // setup advertisements
186     uint16_t adv_int_min = 0x0030;
187     uint16_t adv_int_max = 0x0030;
188     uint8_t adv_type = 0;
189     bd_addr_t null_addr;
190     memset(null_addr, 0, 6);
191     gap_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 0, null_addr, 0x07, 0x00);
192     gap_advertisements_set_data(adv_data_len, (uint8_t*) adv_data);
193     gap_advertisements_enable(1);
194 
195     // init client state
196     init_connections();
197 }
198 /* LISTING_END */
199 
200 /*
201  * @section Track throughput
202  * @text We calculate the throughput by setting a start time and measuring the amount of
203  * data sent. After a configurable REPORT_INTERVAL_MS, we print the throughput in kB/s
204  * and reset the counter and start time.
205  */
206 
207 /* LISTING_START(tracking): Tracking throughput */
208 
209 static void test_reset(le_streamer_connection_t * context){
210     context->test_data_start = btstack_run_loop_get_time_ms();
211     context->test_data_sent = 0;
212 }
213 
214 static void test_track_sent(le_streamer_connection_t * context, int bytes_sent){
215     context->test_data_sent += bytes_sent;
216     // evaluate
217     uint32_t now = btstack_run_loop_get_time_ms();
218     uint32_t time_passed = now - context->test_data_start;
219     if (time_passed < REPORT_INTERVAL_MS) return;
220     // print speed
221     int bytes_per_second = context->test_data_sent * 1000 / time_passed;
222     printf("%c: %"PRIu32" bytes sent-> %u.%03u kB/s\n", context->name, context->test_data_sent, bytes_per_second / 1000, bytes_per_second % 1000);
223 
224     // restart
225     context->test_data_start = now;
226     context->test_data_sent  = 0;
227 }
228 /* LISTING_END(tracking): Tracking throughput */
229 
230 /*
231  * @section HCI Packet Handler
232  *
233  * @text The packet handler is used track incoming connections and to stop notifications on disconnect
234  * It is also a good place to request the connection parameter update as indicated
235  * in the commented code block.
236  */
237 
238 /* LISTING_START(hciPacketHandler): Packet Handler */
239 static void hci_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
240     UNUSED(channel);
241     UNUSED(size);
242 
243     if (packet_type != HCI_EVENT_PACKET) return;
244 
245     uint16_t conn_interval;
246     hci_con_handle_t con_handle;
247     static const char * const phy_names[] = {
248         "1 M", "2 M", "Codec"
249     };
250 
251     switch (hci_event_packet_get_type(packet)) {
252         case BTSTACK_EVENT_STATE:
253             // BTstack activated, get started
254             if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING) {
255                 printf("To start the streaming, please run the le_streamer_client example on other device, or use some GATT Explorer, e.g. LightBlue, BLExplr.\n");
256             }
257             break;
258         case HCI_EVENT_DISCONNECTION_COMPLETE:
259             con_handle = hci_event_disconnection_complete_get_connection_handle(packet);
260             printf("- LE Connection 0x%04x: disconnect, reason %02x\n", con_handle, hci_event_disconnection_complete_get_reason(packet));
261             break;
262         case HCI_EVENT_LE_META:
263             switch (hci_event_le_meta_get_subevent_code(packet)) {
264                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
265                     // print connection parameters (without using float operations)
266                     con_handle    = hci_subevent_le_connection_complete_get_connection_handle(packet);
267                     conn_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
268                     printf("- LE Connection 0x%04x: connected - connection interval %u.%02u ms, latency %u\n", con_handle, conn_interval * 125 / 100,
269                         25 * (conn_interval & 3), hci_subevent_le_connection_complete_get_conn_latency(packet));
270 
271                     // request min con interval 15 ms for iOS 11+
272                     printf("- LE Connection 0x%04x: request 15 ms connection interval\n", con_handle);
273                     gap_request_connection_parameter_update(con_handle, 12, 12, 0, 0x0048);
274                     break;
275                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
276                     // print connection parameters (without using float operations)
277                     con_handle    = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
278                     conn_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
279                     printf("- LE Connection 0x%04x: connection update - connection interval %u.%02u ms, latency %u\n", con_handle, conn_interval * 125 / 100,
280                         25 * (conn_interval & 3), hci_subevent_le_connection_update_complete_get_conn_latency(packet));
281                     break;
282                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
283                     con_handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
284                     printf("- LE Connection 0x%04x: data length change - max %u bytes per packet\n", con_handle,
285                            hci_subevent_le_data_length_change_get_max_tx_octets(packet));
286                     break;
287                 case HCI_SUBEVENT_LE_PHY_UPDATE_COMPLETE:
288                     con_handle = hci_subevent_le_phy_update_complete_get_connection_handle(packet);
289                     printf("- LE Connection 0x%04x: PHY update - using LE %s PHY now\n", con_handle,
290                            phy_names[hci_subevent_le_phy_update_complete_get_tx_phy(packet)]);
291                     break;
292                 default:
293                     break;
294             }
295             break;
296 
297         default:
298             break;
299     }
300 }
301 
302 /* LISTING_END */
303 
304 /*
305  * @section ATT Packet Handler
306  *
307  * @text The packet handler is used to track the ATT MTU Exchange and trigger ATT send
308  */
309 
310 /* LISTING_START(attPacketHandler): Packet Handler */
311 static void att_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
312     UNUSED(channel);
313     UNUSED(size);
314 
315     int mtu;
316     le_streamer_connection_t * context;
317     switch (packet_type) {
318         case HCI_EVENT_PACKET:
319             switch (hci_event_packet_get_type(packet)) {
320                 case ATT_EVENT_CONNECTED:
321                     // setup new
322                     context = connection_for_conn_handle(HCI_CON_HANDLE_INVALID);
323                     if (!context) break;
324                     context->counter = 'A';
325                     context->connection_handle = att_event_connected_get_handle(packet);
326                     context->test_data_len = btstack_min(att_server_get_mtu(context->connection_handle) - 3, sizeof(context->test_data));
327                     printf("%c: ATT connected, handle 0x%04x, test data len %u\n", context->name, context->connection_handle, context->test_data_len);
328                     break;
329                 case ATT_EVENT_MTU_EXCHANGE_COMPLETE:
330                     mtu = att_event_mtu_exchange_complete_get_MTU(packet) - 3;
331                     context = connection_for_conn_handle(att_event_mtu_exchange_complete_get_handle(packet));
332                     if (!context) break;
333                     context->test_data_len = btstack_min(mtu - 3, sizeof(context->test_data));
334                     printf("%c: ATT MTU = %u => use test data of len %u\n", context->name, mtu, context->test_data_len);
335                     break;
336                 case ATT_EVENT_CAN_SEND_NOW:
337                     streamer();
338                     break;
339                 case ATT_EVENT_DISCONNECTED:
340                     context = connection_for_conn_handle(att_event_disconnected_get_handle(packet));
341                     if (!context) break;
342                     // free connection
343                     printf("%c: ATT disconnected, handle 0x%04x\n", context->name, context->connection_handle);
344                     context->le_notification_enabled = 0;
345                     context->connection_handle = HCI_CON_HANDLE_INVALID;
346                     break;
347                 default:
348                     break;
349             }
350             break;
351         default:
352             break;
353     }
354 }
355 /* LISTING_END */
356 
357 /*
358  * @section Streamer
359  *
360  * @text The streamer function checks if notifications are enabled and if a notification can be sent now.
361  * It creates some test data - a single letter that gets increased every time - and tracks the data sent.
362  */
363 
364  /* LISTING_START(streamer): Streaming code */
365 static void streamer(void){
366 
367     // find next active streaming connection
368     int old_connection_index = connection_index;
369     while (1){
370         // active found?
371         if ((le_streamer_connections[connection_index].connection_handle != HCI_CON_HANDLE_INVALID) &&
372             (le_streamer_connections[connection_index].le_notification_enabled)) break;
373 
374         // check next
375         next_connection_index();
376 
377         // none found
378         if (connection_index == old_connection_index) return;
379     }
380 
381     le_streamer_connection_t * context = &le_streamer_connections[connection_index];
382 
383     // create test data
384     context->counter++;
385     if (context->counter > 'Z') context->counter = 'A';
386     memset(context->test_data, context->counter, context->test_data_len);
387 
388     // send
389     att_server_notify(context->connection_handle, context->value_handle, (uint8_t*) context->test_data, context->test_data_len);
390 
391     // track
392     test_track_sent(context, context->test_data_len);
393 
394     // request next send event
395     att_server_request_can_send_now_event(context->connection_handle);
396 
397     // check next
398     next_connection_index();
399 }
400 /* LISTING_END */
401 
402 /*
403  * @section ATT Write
404  *
405  * @text The only valid ATT write in this example is to the Client Characteristic Configuration, which configures notification
406  * and indication. If the ATT handle matches the client configuration handle, the new configuration value is stored.
407  * If notifications get enabled, an ATT_EVENT_CAN_SEND_NOW is requested. See Listing attWrite.
408  */
409 
410 /* LISTING_START(attWrite): ATT Write */
411 static int att_write_callback(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size){
412     UNUSED(offset);
413 
414     // printf("att_write_callback att_handle 0x%04x, transaction mode %u\n", att_handle, transaction_mode);
415     if (transaction_mode != ATT_TRANSACTION_MODE_NONE) return 0;
416     le_streamer_connection_t * context = connection_for_conn_handle(con_handle);
417     switch(att_handle){
418         case ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_CLIENT_CONFIGURATION_HANDLE:
419         case ATT_CHARACTERISTIC_0000FF12_0000_1000_8000_00805F9B34FB_01_CLIENT_CONFIGURATION_HANDLE:
420             context->le_notification_enabled = little_endian_read_16(buffer, 0) == GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION;
421             printf("%c: Notifications enabled %u\n", context->name, context->le_notification_enabled);
422             if (context->le_notification_enabled){
423                 switch (att_handle){
424                     case ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_CLIENT_CONFIGURATION_HANDLE:
425                         context->value_handle = ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE;
426                         break;
427                     case ATT_CHARACTERISTIC_0000FF12_0000_1000_8000_00805F9B34FB_01_CLIENT_CONFIGURATION_HANDLE:
428                         context->value_handle = ATT_CHARACTERISTIC_0000FF12_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE;
429                         break;
430                     default:
431                         break;
432                 }
433                 att_server_request_can_send_now_event(context->connection_handle);
434             }
435             test_reset(context);
436             break;
437         case ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE:
438         case ATT_CHARACTERISTIC_0000FF12_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE:
439             test_track_sent(context, buffer_size);
440             break;
441         default:
442             printf("Write to 0x%04x, len %u\n", att_handle, buffer_size);
443             break;
444     }
445     return 0;
446 }
447 /* LISTING_END */
448 
449 int btstack_main(void);
450 int btstack_main(void)
451 {
452     le_streamer_setup();
453 
454     // turn on!
455 	hci_power_control(HCI_POWER_ON);
456 
457     return 0;
458 }
459 /* EXAMPLE_END */
460