xref: /btstack/example/hog_host_demo.c (revision 2901a9b7af2a81f193187d7d58a554b5f7f1928c)
1 /*
2  * Copyright (C) 2020 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 #define BTSTACK_FILE__ "hog_boot_host_demo.c"
39 
40 /*
41  * hog_boot_host_demo.c
42  */
43 
44 /* EXAMPLE_START(hog_boot_host_demo): HID Boot Host LE
45  *
46  * @text This example implements a minimal HID-over-GATT Boot Host. It scans for LE HID devices, connects to it,
47  * discovers the Characteristics relevant for the HID Service and enables Notifications on them.
48  * It then dumps all Boot Keyboard and Mouse Input Reports
49  */
50 
51 #include <inttypes.h>
52 #include <stdio.h>
53 #include <btstack_tlv.h>
54 
55 #include "btstack_config.h"
56 #include "btstack.h"
57 
58 // TAG to store remote device address and type in TLV
59 #define TLV_TAG_HOGD ((((uint32_t) 'H') << 24 ) | (((uint32_t) 'O') << 16) | (((uint32_t) 'G') << 8) | 'D')
60 
61 typedef struct {
62     bd_addr_t addr;
63     bd_addr_type_t addr_type;
64 } le_device_addr_t;
65 
66 static enum {
67     W4_WORKING,
68     W4_HID_DEVICE_FOUND,
69     W4_CONNECTED,
70     W4_ENCRYPTED,
71     W4_HID_CLIENT_CONNECTED,
72     READY,
73     W4_TIMEOUT_THEN_SCAN,
74     W4_TIMEOUT_THEN_RECONNECT,
75 } app_state;
76 
77 static le_device_addr_t remote_device;
78 static hci_con_handle_t connection_handle;
79 static uint16_t hids_cid;
80 
81 // used to implement connection timeout and reconnect timer
82 static btstack_timer_source_t connection_timer;
83 
84 // register for events from HCI/GAP and SM
85 static btstack_packet_callback_registration_t hci_event_callback_registration;
86 static btstack_packet_callback_registration_t sm_event_callback_registration;
87 
88 // used to store remote device in TLV
89 static const btstack_tlv_t * btstack_tlv_singleton_impl;
90 static void *                btstack_tlv_singleton_context;
91 
92 // Simplified US Keyboard with Shift modifier
93 
94 #define CHAR_ILLEGAL     0xff
95 #define CHAR_RETURN     '\n'
96 #define CHAR_ESCAPE      27
97 #define CHAR_TAB         '\t'
98 #define CHAR_BACKSPACE   0x7f
99 
100 /**
101  * English (US)
102  */
103 static const uint8_t keytable_us_none [] = {
104         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*   0-3 */
105         'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',                   /*  4-13 */
106         'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',                   /* 14-23 */
107         'u', 'v', 'w', 'x', 'y', 'z',                                       /* 24-29 */
108         '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',                   /* 30-39 */
109         CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
110         '-', '=', '[', ']', '\\', CHAR_ILLEGAL, ';', '\'', 0x60, ',',       /* 45-54 */
111         '.', '/', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
112         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
113         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
114         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
115         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
116         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
117         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
118         '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
119         '6', '7', '8', '9', '0', '.', 0xa7,                                 /* 97-100 */
120 };
121 
122 static const uint8_t keytable_us_shift[] = {
123         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*  0-3  */
124         'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',                   /*  4-13 */
125         'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',                   /* 14-23 */
126         'U', 'V', 'W', 'X', 'Y', 'Z',                                       /* 24-29 */
127         '!', '@', '#', '$', '%', '^', '&', '*', '(', ')',                   /* 30-39 */
128         CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
129         '_', '+', '{', '}', '|', CHAR_ILLEGAL, ':', '"', 0x7E, '<',         /* 45-54 */
130         '>', '?', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
131         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
132         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
133         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
134         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
135         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
136         CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
137         '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
138         '6', '7', '8', '9', '0', '.', 0xb1,                                 /* 97-100 */
139 };
140 
141 /**
142  * @section HOG Boot Keyboard Handler
143  * @text Boot Keyboard Input Report contains a report of format
144  * [ modifier, reserved, 6 x usage for key 1..6 from keyboard usage]
145  * Track new usages, map key usage to actual character and simulate terminal
146  */
147 
148 /* last_keys stores keyboard report to detect new key down events */
149 #define NUM_KEYS 6
150 static uint8_t last_keys[NUM_KEYS];
151 
152 static void handle_boot_keyboard_event(const uint8_t * report, uint16_t report_len){
153     UNUSED(report_len);
154 
155     uint8_t new_keys[NUM_KEYS];
156     memset(new_keys, 0, sizeof(new_keys));
157     int new_keys_count = 0;
158 
159     bool shift = (report[0] & 0x22) != 0;
160 
161     uint8_t key_index;
162     for (key_index = 0; key_index < NUM_KEYS; key_index++){
163 
164         uint16_t usage = report[2 + key_index];
165         if (usage == 0) continue;
166         if (usage >= sizeof(keytable_us_none)) continue;
167 
168         // store new keys
169         new_keys[new_keys_count++] = usage;
170 
171         // check if usage was used last time (and ignore in that case)
172         int i;
173         for (i=0;i<NUM_KEYS;i++){
174             if (usage == last_keys[i]){
175                 usage = 0;
176             }
177         }
178         if (usage == 0) continue;
179 
180         // lookup character based on usage + shift modifier
181         uint8_t key;
182         if (shift){
183             key = keytable_us_shift[usage];
184         } else {
185             key = keytable_us_none[usage];
186         }
187         if (key == CHAR_ILLEGAL) continue;
188         if (key == CHAR_BACKSPACE){
189             printf("\b \b");    // go back one char, print space, go back one char again
190             continue;
191         }
192         printf("%c", key);
193     }
194 
195     // store current as last report
196     memcpy(last_keys, new_keys, NUM_KEYS);
197 }
198 
199 /**
200  * @section HOG Boot Mouse Handler
201  * @text Boot Mouse Input Report contains a report of format
202  * [ buttons, dx, dy, dz = scroll wheel]
203  * Decode packet and print on stdout
204  *
205  * @param report
206  * @param report_len
207  */
208 static void handle_boot_mouse_event(const uint8_t * report, uint16_t report_len){
209     UNUSED(report_len);
210 
211     uint8_t buttons =          report[0];
212     int8_t dx       = (int8_t) report[1];
213     int8_t dy       = (int8_t) report[2];
214     int8_t dwheel   = (int8_t) report[3];
215     printf("Mouse: %i, %i - wheel %i - buttons 0x%02x\n", dx, dy, dwheel, buttons);
216 }
217 
218 /**
219  * @section Test if advertisement contains HID UUID
220  * @param packet
221  * @param size
222  * @returns true if it does
223  */
224 static bool adv_event_contains_hid_service(const uint8_t * packet){
225     const uint8_t * ad_data = gap_event_advertising_report_get_data(packet);
226     uint16_t ad_len = gap_event_advertising_report_get_data_length(packet);
227     return ad_data_contains_uuid16(ad_len, ad_data, ORG_BLUETOOTH_SERVICE_HUMAN_INTERFACE_DEVICE);
228 }
229 
230 /**
231  * Start scanning
232  */
233 static void hog_start_scan(void){
234     printf("Scanning for LE HID devices...\n");
235     app_state = W4_HID_DEVICE_FOUND;
236     // Passive scanning, 100% (scan interval = scan window)
237     gap_set_scan_parameters(0,48,48);
238     gap_start_scan();
239 }
240 
241 /**
242  * Handle timeout for outgoing connection
243  * @param ts
244  */
245 static void hog_connection_timeout(btstack_timer_source_t * ts){
246     UNUSED(ts);
247     printf("Timeout - abort connection\n");
248     gap_connect_cancel();
249     hog_start_scan();
250 }
251 
252 
253 /**
254  * Connect to remote device but set timer for timeout
255  */
256 static void hog_connect(void) {
257     // set timer
258     btstack_run_loop_set_timer(&connection_timer, 10000);
259     btstack_run_loop_set_timer_handler(&connection_timer, &hog_connection_timeout);
260     btstack_run_loop_add_timer(&connection_timer);
261     app_state = W4_CONNECTED;
262     gap_connect(remote_device.addr, remote_device.addr_type);
263 }
264 
265 /**
266  * Handle timer event to trigger reconnect
267  * @param ts
268  */
269 static void hog_reconnect_timeout(btstack_timer_source_t * ts){
270     UNUSED(ts);
271     switch (app_state){
272         case W4_TIMEOUT_THEN_RECONNECT:
273             hog_connect();
274             break;
275         case W4_TIMEOUT_THEN_SCAN:
276             hog_start_scan();
277             break;
278         default:
279             break;
280     }
281 }
282 
283 /**
284  * Start connecting after boot up: connect to last used device if possible, start scan otherwise
285  */
286 static void hog_start_connect(void){
287     // check if we have a bonded device
288     btstack_tlv_get_instance(&btstack_tlv_singleton_impl, &btstack_tlv_singleton_context);
289     if (btstack_tlv_singleton_impl){
290         int len = btstack_tlv_singleton_impl->get_tag(btstack_tlv_singleton_context, TLV_TAG_HOGD, (uint8_t *) &remote_device, sizeof(remote_device));
291         if (len == sizeof(remote_device)){
292             printf("Bonded, connect to device with %s address %s ...\n", remote_device.addr_type == 0 ? "public" : "random" , bd_addr_to_str(remote_device.addr));
293             hog_connect();
294             return;
295         }
296     }
297     // otherwise, scan for HID devices
298     hog_start_scan();
299 }
300 
301 /**
302  * In case of error, disconnect and start scanning again
303  */
304 static void handle_outgoing_connection_error(void){
305     printf("Error occurred, disconnect and start over\n");
306     gap_disconnect(connection_handle);
307     hog_start_scan();
308 }
309 
310 /**
311  * Handle GATT Client Events dependent on current state
312  *
313  * @param packet_type
314  * @param channel
315  * @param packet
316  * @param size
317  */
318 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
319     UNUSED(packet_type);
320     UNUSED(channel);
321     UNUSED(size);
322 
323     uint8_t status;
324     uint8_t report_id;
325 
326     if (hci_event_packet_get_type(packet) != HCI_EVENT_GATTSERVICE_META){
327         return;
328     }
329 
330     switch (hci_event_gattservice_meta_get_subevent_code(packet)){
331         case GATTSERVICE_SUBEVENT_HID_SERVICE_CONNECTED:
332             status = gattservice_subevent_hid_service_connected_get_status(packet);
333             switch (status){
334                 case ERROR_CODE_SUCCESS:
335                     printf("HID service client connected, found %d services\n",
336                         gattservice_subevent_hid_service_connected_get_num_instances(packet));
337 
338                                         // store device as bonded
339                     if (btstack_tlv_singleton_impl){
340                         btstack_tlv_singleton_impl->store_tag(btstack_tlv_singleton_context, TLV_TAG_HOGD, (const uint8_t *) &remote_device, sizeof(remote_device));
341                     }
342                     // done
343                     printf("Ready - please start typing or mousing..\n");
344                     app_state = READY;
345                     break;
346                 default:
347                     printf("HID service client connection failed, err 0x%02x.\n", status);
348                     handle_outgoing_connection_error();
349                     break;
350             }
351             break;
352         case GATTSERVICE_SUBEVENT_HID_REPORT:
353             report_id = gattservice_subevent_hid_report_get_report_id(packet);
354             switch (report_id){
355                 case HID_BOOT_MODE_MOUSE_ID:
356                     handle_boot_mouse_event(
357                         gattservice_subevent_hid_report_get_report(packet),
358                         gattservice_subevent_hid_report_get_report_len(packet));
359                     break;
360                 case HID_BOOT_MODE_KEYBOARD_ID:
361                     handle_boot_keyboard_event(
362                         gattservice_subevent_hid_report_get_report(packet),
363                         gattservice_subevent_hid_report_get_report_len(packet));
364                     break;
365                 default:
366                     break;
367             }
368             break;
369 
370         default:
371             break;
372     }
373 }
374 
375 /* LISTING_START(packetHandler): Packet Handler */
376 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
377     /* LISTING_PAUSE */
378     UNUSED(channel);
379     UNUSED(size);
380     uint8_t event;
381     uint8_t status;
382     /* LISTING_RESUME */
383     switch (packet_type) {
384         case HCI_EVENT_PACKET:
385             event = hci_event_packet_get_type(packet);
386             switch (event) {
387                 case BTSTACK_EVENT_STATE:
388                     if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) break;
389                     btstack_assert(app_state == W4_WORKING);
390 
391                     hog_start_connect();
392                     break;
393                 case GAP_EVENT_ADVERTISING_REPORT:
394                     if (app_state != W4_HID_DEVICE_FOUND) break;
395                     if (adv_event_contains_hid_service(packet) == false) break;
396                     // stop scan
397                     gap_stop_scan();
398                     // store remote device address and type
399                     gap_event_advertising_report_get_address(packet, remote_device.addr);
400                     remote_device.addr_type = gap_event_advertising_report_get_address_type(packet);
401                     // connect
402                     printf("Found, connect to device with %s address %s ...\n", remote_device.addr_type == 0 ? "public" : "random" , bd_addr_to_str(remote_device.addr));
403                     hog_connect();
404                     break;
405                 case HCI_EVENT_DISCONNECTION_COMPLETE:
406                     if (app_state != READY) break;
407                     connection_handle = HCI_CON_HANDLE_INVALID;
408                     switch (app_state){
409                         case READY:
410                             printf("\nDisconnected, try to reconnect...\n");
411                             app_state = W4_TIMEOUT_THEN_RECONNECT;
412                             break;
413                         default:
414                             printf("\nDisconnected, start over...\n");
415                             app_state = W4_TIMEOUT_THEN_SCAN;
416                             break;
417                     }
418                     // set timer
419                     btstack_run_loop_set_timer(&connection_timer, 100);
420                     btstack_run_loop_set_timer_handler(&connection_timer, &hog_reconnect_timeout);
421                     btstack_run_loop_add_timer(&connection_timer);
422                     break;
423                 case HCI_EVENT_LE_META:
424                     // wait for connection complete
425                     if (hci_event_le_meta_get_subevent_code(packet) != HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
426                     if (app_state != W4_CONNECTED) return;
427                     btstack_run_loop_remove_timer(&connection_timer);
428                     connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
429                     // request security
430                     app_state = W4_ENCRYPTED;
431                     sm_request_pairing(connection_handle);
432                     break;
433                 case HCI_EVENT_ENCRYPTION_CHANGE:
434                     if (connection_handle != hci_event_encryption_change_get_connection_handle(packet)) break;
435                     printf("Connection encrypted: %u\n", hci_event_encryption_change_get_encryption_enabled(packet));
436                     if (hci_event_encryption_change_get_encryption_enabled(packet) == 0){
437                         printf("Encryption failed -> abort\n");
438                         handle_outgoing_connection_error();
439                         break;
440                     }
441                     // continue - query primary services
442                     printf("Search for HID service.\n");
443                     app_state = W4_HID_CLIENT_CONNECTED;
444 
445                     status = hids_client_connect(connection_handle, handle_gatt_client_event, HID_PROTOCOL_MODE_BOOT, &hids_cid);
446                     if (status != ERROR_CODE_SUCCESS){
447                         printf("HID client connection failed, status 0x%02x\n", status);
448                     }
449                     break;
450                 default:
451                     break;
452             }
453             break;
454         default:
455             break;
456     }
457 }
458 /* LISTING_END */
459 
460 /* @section HCI packet handler
461  *
462  * @text The SM packet handler receives Security Manager Events required for pairing.
463  * It also receives events generated during Identity Resolving
464  * see Listing SMPacketHandler.
465  */
466 
467 /* LISTING_START(SMPacketHandler): Scanning and receiving advertisements */
468 
469 static void sm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
470     UNUSED(channel);
471     UNUSED(size);
472 
473     if (packet_type != HCI_EVENT_PACKET) return;
474 
475     switch (hci_event_packet_get_type(packet)) {
476         case SM_EVENT_JUST_WORKS_REQUEST:
477             printf("Just works requested\n");
478             sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));
479             break;
480         case SM_EVENT_NUMERIC_COMPARISON_REQUEST:
481             printf("Confirming numeric comparison: %"PRIu32"\n", sm_event_numeric_comparison_request_get_passkey(packet));
482             sm_numeric_comparison_confirm(sm_event_passkey_display_number_get_handle(packet));
483             break;
484         case SM_EVENT_PASSKEY_DISPLAY_NUMBER:
485             printf("Display Passkey: %"PRIu32"\n", sm_event_passkey_display_number_get_passkey(packet));
486             break;
487         case SM_EVENT_PAIRING_COMPLETE:
488             switch (sm_event_pairing_complete_get_status(packet)){
489                 case ERROR_CODE_SUCCESS:
490                     printf("Pairing complete, success\n");
491                     break;
492                 case ERROR_CODE_CONNECTION_TIMEOUT:
493                     printf("Pairing failed, timeout\n");
494                     break;
495                 case ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION:
496                     printf("Pairing faileed, disconnected\n");
497                     break;
498                 case ERROR_CODE_AUTHENTICATION_FAILURE:
499                     printf("Pairing failed, reason = %u\n", sm_event_pairing_complete_get_reason(packet));
500                     break;
501                 default:
502                     break;
503             }
504             break;
505         default:
506             break;
507     }
508 }
509 /* LISTING_END */
510 
511 int btstack_main(int argc, const char * argv[]);
512 int btstack_main(int argc, const char * argv[]){
513 
514     (void)argc;
515     (void)argv;
516 
517     /* LISTING_START(HogBootHostSetup): HID-over-GATT Boot Host Setup */
518 
519     // register for events from HCI
520     hci_event_callback_registration.callback = &packet_handler;
521     hci_add_event_handler(&hci_event_callback_registration);
522 
523     // register for events from Security Manager
524     sm_event_callback_registration.callback = &sm_packet_handler;
525     sm_add_event_handler(&sm_event_callback_registration);
526 
527     // setup le device db
528     le_device_db_init();
529 
530     //
531     l2cap_init();
532     sm_init();
533     gatt_client_init();
534     hids_client_init();
535 
536     /* LISTING_END */
537 
538     // Disable stdout buffering
539     setbuf(stdout, NULL);
540 
541     app_state = W4_WORKING;
542 
543     // Turn on the device
544     hci_power_control(HCI_POWER_ON);
545     return 0;
546 }
547 
548 /* EXAMPLE_END */
549