xref: /btstack/example/le_credit_based_flow_control_mode_server.c (revision e3ba22907f903f11cd12321c31e7936b8dd1157e)
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__ "le_credit_based_flow_control_mode_server.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(le_credit_based_flow_control_mode_server): LE Credit-Based Flow-Control Mode Server - Receive data over L2CAP
42  *
43  * @text iOS 11 and newer supports L2CAP channels in LE Credit-Based Flow-Control Mode for fast transfer over LE
44  *       [https://github.com/bluekitchen/CBL2CAPChannel-Demo](Basic iOS example on GitHub)
45  */
46  // *****************************************************************************
47 
48 #include <inttypes.h>
49 #include <stdint.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 
54 #include "btstack.h"
55 #include "le_credit_based_flow_control_mode_server.h"
56 
57 // #define TEST_STREAM_DATA
58 #define TEST_PACKET_SIZE 1000
59 
60 #define REPORT_INTERVAL_MS 3000
61 #define MAX_NR_CONNECTIONS 3
62 
63 const uint16_t TSPX_le_psm = 0x25;
64 
65 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
66 static void sm_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
67 
68 const uint8_t adv_data[] = {
69     // Flags general discoverable, BR/EDR not supported
70     0x02, 0x01, 0x06,
71     // Name
72     0x0E, 0x09, 'L', 'E', ' ', 'C', 'B', 'M',  ' ', 'S', 'e', 'r', 'v', 'e', 'r',
73 };
74 const uint8_t adv_data_len = sizeof(adv_data);
75 
76 static btstack_packet_callback_registration_t hci_event_callback_registration;
77 static btstack_packet_callback_registration_t l2cap_event_callback_registration;
78 static btstack_packet_callback_registration_t sm_event_callback_registration;
79 
80 // support for multiple clients
81 typedef struct {
82     char name;
83     hci_con_handle_t connection_handle;
84     uint16_t cid;
85     int  counter;
86     char test_data[TEST_PACKET_SIZE];
87     int  test_data_len;
88     uint32_t test_data_sent;
89     uint32_t test_data_start;
90 } le_cbm_connection_t;
91 
92 static le_cbm_connection_t le_cbm_connection;
93 
94 static uint16_t initial_credits = L2CAP_LE_AUTOMATIC_CREDITS;
95 static uint8_t data_channel_buffer[TEST_PACKET_SIZE];
96 
97 /*
98  * @section Track throughput
99  * @text We calculate the throughput by setting a start time and measuring the amount of
100  * data sent. After a configurable REPORT_INTERVAL_MS, we print the throughput in kB/s
101  * and reset the counter and start time.
102  */
103 
104 /* LISTING_START(tracking): Tracking throughput */
105 
106 static void test_reset(le_cbm_connection_t * context){
107     context->test_data_start = btstack_run_loop_get_time_ms();
108     context->test_data_sent = 0;
109 }
110 
111 static void test_track_data(le_cbm_connection_t * context, int bytes_transferred){
112     context->test_data_sent += bytes_transferred;
113     // evaluate
114     uint32_t now = btstack_run_loop_get_time_ms();
115     uint32_t time_passed = now - context->test_data_start;
116     if (time_passed < REPORT_INTERVAL_MS) return;
117     // print speed
118     int bytes_per_second = context->test_data_sent * 1000 / time_passed;
119     printf("%c: %"PRIu32" bytes sent-> %u.%03u kB/s\n", context->name, context->test_data_sent, bytes_per_second / 1000, bytes_per_second % 1000);
120 
121     // restart
122     context->test_data_start = now;
123     context->test_data_sent  = 0;
124 }
125 /* LISTING_END(tracking): Tracking throughput */
126 
127 #ifdef TEST_STREAM_DATA
128 /* LISTING_END */
129 /*
130  * @section Streamer
131  *
132  * @text The streamer function checks if notifications are enabled and if a notification can be sent now.
133  * It creates some test data - a single letter that gets increased every time - and tracks the data sent.
134  */
135 
136  /* LISTING_START(streamer): Streaming code */
137 static void streamer(void){
138 
139     if (le_data_channel_connection.cid == 0) return;
140 
141     // create test data
142     le_data_channel_connection.counter++;
143     if (le_data_channel_connection.counter > 'Z') le_data_channel_connection.counter = 'A';
144     memset(le_data_channel_connection.test_data, le_data_channel_connection.counter, le_data_channel_connection.test_data_len);
145 
146     // send
147     l2cap_cbm_send_data(le_data_channel_connection.cid, (uint8_t *) le_data_channel_connection.test_data, le_data_channel_connection.test_data_len);
148 
149     // track
150     test_track_data(&le_data_channel_connection, le_data_channel_connection.test_data_len);
151 
152     // request another packet
153     l2cap_cbm_request_can_send_now_event(le_data_channel_connection.cid);
154 }
155 /* LISTING_END */
156 #endif
157 
158 
159 /*
160  * @section HCI + L2CAP Packet Handler
161  *
162  * @text The packet handler is used to stop the notifications and reset the MTU on connect
163  * It would also be a good place to request the connection parameter update as indicated
164  * in the commented code block.
165  */
166 
167 /* LISTING_START(packetHandler): Packet Handler */
168 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
169     UNUSED(channel);
170 
171     bd_addr_t event_address;
172     uint16_t psm;
173     uint16_t cid;
174     uint16_t conn_interval;
175     hci_con_handle_t handle;
176     uint8_t status;
177 
178     switch (packet_type) {
179         case HCI_EVENT_PACKET:
180             switch (hci_event_packet_get_type(packet)) {
181                 case BTSTACK_EVENT_STATE:
182                 // BTstack activated, get started
183                 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING) {
184                     printf("To start streaming, please run the le_credit_based_flow_control_mode_client example on other device.\n");
185                 }
186                 break;
187                 case HCI_EVENT_DISCONNECTION_COMPLETE:
188                     // free connection
189                     printf("%c: Disconnect, reason 0x%02x\n", le_cbm_connection.name, hci_event_disconnection_complete_get_reason(packet));
190                     le_cbm_connection.connection_handle = HCI_CON_HANDLE_INVALID;
191                     break;
192                 case HCI_EVENT_LE_META:
193                     switch (hci_event_le_meta_get_subevent_code(packet)) {
194                         case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
195                             // print connection parameters (without using float operations)
196                             conn_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
197                             printf("%c: Connection Interval: %u.%02u ms\n", le_cbm_connection.name, conn_interval * 125 / 100, 25 * (conn_interval & 3));
198                             printf("%c: Connection Latency: %u\n", le_cbm_connection.name, hci_subevent_le_connection_complete_get_conn_latency(packet));
199 
200                             // min con interval 15 ms - supported from iOS 11
201                             gap_request_connection_parameter_update(le_cbm_connection.connection_handle, 12, 12, 0, 0x0048);
202                             printf("Connected, requesting conn param update for handle 0x%04x\n", le_cbm_connection.connection_handle);
203                             //
204                             test_reset(&le_cbm_connection);
205                             break;
206                         case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
207                             // print connection parameters (without using float operations)
208                             conn_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
209                             printf("LE Connection Update:\n");
210                             printf("%c: Connection Interval: %u.%02u ms\n", le_cbm_connection.name, conn_interval * 125 / 100, 25 * (conn_interval & 3));
211                             printf("%c: Connection Latency: %u\n", le_cbm_connection.name, hci_subevent_le_connection_update_complete_get_conn_latency(packet));
212                             break;
213                         default:
214                             break;
215                     }
216                     break;
217 
218                 case L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE:
219                     printf("L2CAP Connection Parameter Update Complete, result: 0x%02x\n", l2cap_event_connection_parameter_update_response_get_result(packet));
220                     break;
221 
222                 // LE Credit-based Flow-Control Mode
223 
224                 case L2CAP_EVENT_CBM_INCOMING_CONNECTION:
225                     psm = l2cap_event_cbm_incoming_connection_get_psm(packet);
226                     cid = l2cap_event_cbm_incoming_connection_get_local_cid(packet);
227                     if (psm != TSPX_le_psm) break;
228                     printf("L2CAP: Accepting incoming connection request for 0x%02x, PSM %02x\n", cid, psm);
229                     l2cap_cbm_accept_connection(cid, data_channel_buffer, sizeof(data_channel_buffer), initial_credits);
230                     break;
231 
232                 case L2CAP_EVENT_CBM_CHANNEL_OPENED:
233                     // inform about new l2cap connection
234                     l2cap_event_cbm_channel_opened_get_address(packet, event_address);
235                     psm = l2cap_event_cbm_channel_opened_get_psm(packet);
236                     cid = l2cap_event_cbm_channel_opened_get_local_cid(packet);
237                     handle = l2cap_event_cbm_channel_opened_get_handle(packet);
238                     status = l2cap_event_cbm_channel_opened_get_status(packet);
239                     if (status == ERROR_CODE_SUCCESS) {
240                         printf("L2CAP: Channel successfully opened: %s, handle 0x%04x, psm 0x%02x, local cid 0x%02x, remote cid 0x%02x\n",
241                                bd_addr_to_str(event_address), handle, psm, cid,  little_endian_read_16(packet, 15));
242                         // setup new
243                         le_cbm_connection.counter = 'A';
244                         le_cbm_connection.cid = cid;
245                         le_cbm_connection.connection_handle = handle;
246                         le_cbm_connection.test_data_len = btstack_min(l2cap_event_cbm_channel_opened_get_remote_mtu(packet), sizeof(le_cbm_connection.test_data));
247                         printf("Test packet size: %u\n", le_cbm_connection.test_data_len);
248                         test_reset(&le_cbm_connection);
249 #ifdef TEST_STREAM_DATA
250                         l2cap_cbm_request_can_send_now_event(le_data_channel_connection.cid);
251 #endif
252                     } else {
253                         printf("L2CAP: Connection to device %s failed, status 0x%02x\n", bd_addr_to_str(event_address), status);
254                     }
255                     break;
256 
257                 case L2CAP_EVENT_CHANNEL_CLOSED:
258                     printf("L2CAP: Channel closed\n");
259                     le_cbm_connection.cid = 0;
260                     break;
261 
262 #ifdef TEST_STREAM_DATA
263                 case L2CAP_EVENT_CBM_CAN_SEND_NOW:
264                     streamer();
265                     break;
266 #endif
267 
268                 default:
269                     break;
270             }
271             break;
272 
273         case L2CAP_DATA_PACKET:
274             test_track_data(&le_cbm_connection, size);
275             break;
276 
277         default:
278             break;
279     }
280 }
281 
282 /*
283  * @section SM Packet Handler
284  *
285  * @text The packet handler is used to handle pairing requests
286  */
287 static void sm_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
288     UNUSED(channel);
289     UNUSED(size);
290 
291     if (packet_type != HCI_EVENT_PACKET) return;
292 
293     switch (hci_event_packet_get_type(packet)) {
294         case SM_EVENT_JUST_WORKS_REQUEST:
295             printf("Just Works requested\n");
296             sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));
297             break;
298         case SM_EVENT_NUMERIC_COMPARISON_REQUEST:
299             printf("Confirming numeric comparison: %"PRIu32"\n", sm_event_numeric_comparison_request_get_passkey(packet));
300             sm_numeric_comparison_confirm(sm_event_passkey_display_number_get_handle(packet));
301             break;
302         case SM_EVENT_PASSKEY_DISPLAY_NUMBER:
303             printf("Display Passkey: %"PRIu32"\n", sm_event_passkey_display_number_get_passkey(packet));
304             break;
305         default:
306             break;
307     }
308 }
309 
310 /* @section Main Application Setup
311  *
312  * @text Listing MainConfiguration shows main application code.
313  * It initializes L2CAP, the Security Manager, and configures the ATT Server with the pre-compiled
314  * ATT Database generated from $le_credit_based_flow_control_mode_server.gatt$. Finally, it configures the advertisements
315  * and boots the Bluetooth stack.
316  */
317 
318 int btstack_main(void);
319 int btstack_main(void)
320 {
321     l2cap_init();
322 
323     // setup SM: Display only
324     sm_init();
325 
326     // setup ATT server: iOS disconnects if ATT MTU Exchange fails
327     att_server_init(profile_data, NULL, NULL);
328 
329     // register for HCI events
330     hci_event_callback_registration.callback = &packet_handler;
331     hci_add_event_handler(&hci_event_callback_registration);
332 
333     // register for SM events
334     sm_event_callback_registration.callback = &sm_packet_handler;
335     sm_add_event_handler(&sm_event_callback_registration);
336 
337     // register for L2CAP events
338     l2cap_event_callback_registration.callback = &packet_handler;
339     l2cap_add_event_handler(&l2cap_event_callback_registration);
340 
341     // le data channel setup
342     l2cap_cbm_register_service(&packet_handler, TSPX_le_psm, LEVEL_0);
343 
344     // setup advertisements
345     uint16_t adv_int_min = 0x0030;
346     uint16_t adv_int_max = 0x0030;
347     uint8_t adv_type = 0;
348     bd_addr_t null_addr;
349     memset(null_addr, 0, 6);
350     gap_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 0, null_addr, 0x07, 0x00);
351     gap_advertisements_set_data(adv_data_len, (uint8_t *) adv_data);
352     gap_advertisements_enable(1);
353 
354     // turn on!
355 	hci_power_control(HCI_POWER_ON);
356 
357     return 0;
358 }
359 /* EXAMPLE_END */
360