xref: /btstack/example/hid_host_demo.c (revision 8c3fe4521ae67c63a131dd9394cf1d678701d066)
1 /*
2  * Copyright (C) 2017 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__ "hid_host_demo.c"
39 
40 /*
41  * hid_host_demo.c
42  */
43 
44 /* EXAMPLE_START(hid_host_demo): HID Host Demo
45  *
46  * @text This example implements an HID Host. For now, it connnects to a fixed device, queries the HID SDP
47  * record and opens the HID Control + Interrupt channels
48  */
49 
50 #include <inttypes.h>
51 #include <stdio.h>
52 
53 #include "btstack_config.h"
54 #include "btstack.h"
55 
56 #define MAX_ATTRIBUTE_VALUE_SIZE 300
57 
58 // SDP
59 static uint8_t            hid_descriptor[MAX_ATTRIBUTE_VALUE_SIZE];
60 static uint16_t           hid_descriptor_len;
61 
62 static uint16_t           hid_control_psm;
63 static uint16_t           hid_interrupt_psm;
64 
65 static uint8_t            attribute_value[MAX_ATTRIBUTE_VALUE_SIZE];
66 static const unsigned int attribute_value_buffer_size = MAX_ATTRIBUTE_VALUE_SIZE;
67 
68 // L2CAP
69 static uint16_t           l2cap_hid_control_cid;
70 static uint16_t           l2cap_hid_interrupt_cid;
71 
72 // MBP 2016
73 static const char * remote_addr_string = "F4-0F-24-3B-1B-E1";
74 // iMpulse static const char * remote_addr_string = "64:6E:6C:C1:AA:B5";
75 
76 static bd_addr_t remote_addr;
77 
78 static btstack_packet_callback_registration_t hci_event_callback_registration;
79 
80 // Simplified US Keyboard with Shift modifier
81 
82 #define CHAR_ILLEGAL     0xff
83 #define CHAR_RETURN     '\n'
84 #define CHAR_ESCAPE      27
85 #define CHAR_TAB         '\t'
86 #define CHAR_BACKSPACE   0x7f
87 
88 /**
89  * English (US)
90  */
91 static const uint8_t keytable_us_none [] = {
92     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*   0-3 */
93     'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',                   /*  4-13 */
94     'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',                   /* 14-23 */
95     'u', 'v', 'w', 'x', 'y', 'z',                                       /* 24-29 */
96     '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',                   /* 30-39 */
97     CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
98     '-', '=', '[', ']', '\\', CHAR_ILLEGAL, ';', '\'', 0x60, ',',       /* 45-54 */
99     '.', '/', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
100     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
101     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
102     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
103     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
104     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
105     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
106     '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
107     '6', '7', '8', '9', '0', '.', 0xa7,                                 /* 97-100 */
108 };
109 
110 static const uint8_t keytable_us_shift[] = {
111     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*  0-3  */
112     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',                   /*  4-13 */
113     'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',                   /* 14-23 */
114     'U', 'V', 'W', 'X', 'Y', 'Z',                                       /* 24-29 */
115     '!', '@', '#', '$', '%', '^', '&', '*', '(', ')',                   /* 30-39 */
116     CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
117     '_', '+', '{', '}', '|', CHAR_ILLEGAL, ':', '"', 0x7E, '<',         /* 45-54 */
118     '>', '?', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
119     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
120     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
121     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
122     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
123     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
124     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
125     '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
126     '6', '7', '8', '9', '0', '.', 0xb1,                                 /* 97-100 */
127 };
128 
129 
130 /* @section Main application configuration
131  *
132  * @text In the application configuration, L2CAP is initialized
133  */
134 
135 /* LISTING_START(PanuSetup): Panu setup */
136 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
137 static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
138 
139 static void hid_host_setup(void){
140 
141     // Initialize L2CAP
142     l2cap_init();
143 
144     // register for HCI events
145     hci_event_callback_registration.callback = &packet_handler;
146     hci_add_event_handler(&hci_event_callback_registration);
147 
148     // Allow sniff mode requests by HID device
149     gap_set_default_link_policy_settings(LM_LINK_POLICY_ENABLE_SNIFF_MODE);
150 
151     // Disable stdout buffering
152     setbuf(stdout, NULL);
153 }
154 /* LISTING_END */
155 
156 /* @section SDP parser callback
157  *
158  * @text The SDP parsers retrieves the BNEP PAN UUID as explained in
159  * Section [on SDP BNEP Query example](#sec:sdpbnepqueryExample}.
160  */
161 
162 static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
163 
164     UNUSED(packet_type);
165     UNUSED(channel);
166     UNUSED(size);
167 
168     des_iterator_t attribute_list_it;
169     des_iterator_t additional_des_it;
170     des_iterator_t prot_it;
171     uint8_t       *des_element;
172     uint8_t       *element;
173     uint32_t       uuid;
174     uint8_t        status;
175 
176     switch (hci_event_packet_get_type(packet)){
177         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
178             if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
179                 attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
180                 if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
181                     switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
182                         case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
183                             for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
184                                 if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
185                                 des_element = des_iterator_get_element(&attribute_list_it);
186                                 des_iterator_init(&prot_it, des_element);
187                                 element = des_iterator_get_element(&prot_it);
188                                 if (!element) continue;
189                                 if (de_get_element_type(element) != DE_UUID) continue;
190                                 uuid = de_get_uuid32(element);
191                                 des_iterator_next(&prot_it);
192                                 switch (uuid){
193                                     case BLUETOOTH_PROTOCOL_L2CAP:
194                                         if (!des_iterator_has_more(&prot_it)) continue;
195                                         de_element_get_uint16(des_iterator_get_element(&prot_it), &hid_control_psm);
196                                         printf("HID Control PSM: 0x%04x\n", (int) hid_control_psm);
197                                         break;
198                                     default:
199                                         break;
200                                 }
201                             }
202                             break;
203                         case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS:
204                             for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
205                                 if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
206                                 des_element = des_iterator_get_element(&attribute_list_it);
207                                 for (des_iterator_init(&additional_des_it, des_element); des_iterator_has_more(&additional_des_it); des_iterator_next(&additional_des_it)) {
208                                     if (des_iterator_get_type(&additional_des_it) != DE_DES) continue;
209                                     des_element = des_iterator_get_element(&additional_des_it);
210                                     des_iterator_init(&prot_it, des_element);
211                                     element = des_iterator_get_element(&prot_it);
212                                     if (!element) continue;
213                                     if (de_get_element_type(element) != DE_UUID) continue;
214                                     uuid = de_get_uuid32(element);
215                                     des_iterator_next(&prot_it);
216                                     switch (uuid){
217                                         case BLUETOOTH_PROTOCOL_L2CAP:
218                                             if (!des_iterator_has_more(&prot_it)) continue;
219                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &hid_interrupt_psm);
220                                             printf("HID Interrupt PSM: 0x%04x\n", (int) hid_interrupt_psm);
221                                             break;
222                                         default:
223                                             break;
224                                     }
225                                 }
226                             }
227                             break;
228                         case BLUETOOTH_ATTRIBUTE_HID_DESCRIPTOR_LIST:
229                             for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
230                                 if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
231                                 des_element = des_iterator_get_element(&attribute_list_it);
232                                 for (des_iterator_init(&additional_des_it, des_element); des_iterator_has_more(&additional_des_it); des_iterator_next(&additional_des_it)) {
233                                     if (des_iterator_get_type(&additional_des_it) != DE_STRING) continue;
234                                     element = des_iterator_get_element(&additional_des_it);
235                                     const uint8_t * descriptor = de_get_string(element);
236                                     hid_descriptor_len = de_get_data_size(element);
237                                     memcpy(hid_descriptor, descriptor, hid_descriptor_len);
238                                     printf("HID Descriptor:\n");
239                                     printf_hexdump(hid_descriptor, hid_descriptor_len);
240                                 }
241                             }
242                             break;
243                         default:
244                             break;
245                     }
246                 }
247             } else {
248                 fprintf(stderr, "SDP attribute value buffer size exceeded: available %d, required %d\n", attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet));
249             }
250             break;
251 
252         case SDP_EVENT_QUERY_COMPLETE:
253             if (!hid_control_psm) {
254                 hid_control_psm = BLUETOOTH_PSM_HID_CONTROL;
255                 printf("HID Control PSM missing, using default 0x%04x\n", hid_control_psm);
256             }
257             if (!hid_interrupt_psm) {
258                 hid_interrupt_psm = BLUETOOTH_PSM_HID_INTERRUPT;
259                 printf("HID Interrupt PSM missing, using default 0x%04x\n", hid_interrupt_psm);
260                 break;
261             }
262             printf("Setup HID\n");
263             status = l2cap_create_channel(packet_handler, remote_addr, hid_control_psm, 48, &l2cap_hid_control_cid);
264             if (status){
265                 printf("Connecting to HID Control failed: 0x%02x\n", status);
266             }
267             break;
268     }
269 }
270 
271 /*
272  * @section HID Report Handler
273  *
274  * @text Use BTstack's compact HID Parser to process incoming HID Report
275  * Iterate over all fields and process fields with usage page = 0x07 / Keyboard
276  * Check if SHIFT is down and process first character (don't handle multiple key presses)
277  *
278  */
279 #define NUM_KEYS 6
280 static uint8_t last_keys[NUM_KEYS];
281 static void hid_host_handle_interrupt_report(const uint8_t * report, uint16_t report_len){
282     // check if HID Input Report
283     if (report_len < 1) return;
284     if (*report != 0xa1) return;
285     report++;
286     report_len--;
287     btstack_hid_parser_t parser;
288     btstack_hid_parser_init(&parser, hid_descriptor, hid_descriptor_len, HID_REPORT_TYPE_INPUT, report, report_len);
289     int shift = 0;
290     uint8_t new_keys[NUM_KEYS];
291     memset(new_keys, 0, sizeof(new_keys));
292     int     new_keys_count = 0;
293     while (btstack_hid_parser_has_more(&parser)){
294         uint16_t usage_page;
295         uint16_t usage;
296         int32_t  value;
297         btstack_hid_parser_get_field(&parser, &usage_page, &usage, &value);
298         if (usage_page != 0x07) continue;
299         switch (usage){
300             case 0xe1:
301             case 0xe6:
302                 if (value){
303                     shift = 1;
304                 }
305                 continue;
306             case 0x00:
307                 continue;
308             default:
309                 break;
310         }
311         if (usage >= sizeof(keytable_us_none)) continue;
312 
313         // store new keys
314         new_keys[new_keys_count++] = usage;
315 
316         // check if usage was used last time (and ignore in that case)
317         int i;
318         for (i=0;i<NUM_KEYS;i++){
319             if (usage == last_keys[i]){
320                 usage = 0;
321             }
322         }
323         if (usage == 0) continue;
324 
325         uint8_t key;
326         if (shift){
327             key = keytable_us_shift[usage];
328         } else {
329             key = keytable_us_none[usage];
330         }
331         if (key == CHAR_ILLEGAL) continue;
332         if (key == CHAR_BACKSPACE){
333             printf("\b \b");    // go back one char, print space, go back one char again
334             continue;
335         }
336         printf("%c", key);
337     }
338     memcpy(last_keys, new_keys, NUM_KEYS);
339 }
340 
341 /*
342  * @section Packet Handler
343  *
344  * @text The packet handler responds to various HCI Events.
345  */
346 
347 /* LISTING_START(packetHandler): Packet Handler */
348 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)
349 {
350     /* LISTING_PAUSE */
351     uint8_t   event;
352     bd_addr_t event_addr;
353     uint8_t   status;
354     uint16_t  l2cap_cid;
355 
356     /* LISTING_RESUME */
357     switch (packet_type) {
358 		case HCI_EVENT_PACKET:
359             event = hci_event_packet_get_type(packet);
360             switch (event) {
361                 /* @text When BTSTACK_EVENT_STATE with state HCI_STATE_WORKING
362                  * is received and the example is started in client mode, the remote SDP HID query is started.
363                  */
364                 case BTSTACK_EVENT_STATE:
365                     if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
366                         printf("Start SDP HID query for remote HID Device.\n");
367                         sdp_client_query_uuid16(&handle_sdp_client_query_result, remote_addr, BLUETOOTH_SERVICE_CLASS_HUMAN_INTERFACE_DEVICE_SERVICE);
368                     }
369                     break;
370 
371                 /* LISTING_PAUSE */
372                 case HCI_EVENT_PIN_CODE_REQUEST:
373 					// inform about pin code request
374                     printf("Pin code request - using '0000'\n");
375                     hci_event_pin_code_request_get_bd_addr(packet, event_addr);
376                     gap_pin_code_response(event_addr, "0000");
377 					break;
378 
379                 case HCI_EVENT_USER_CONFIRMATION_REQUEST:
380                     // inform about user confirmation request
381                     printf("SSP User Confirmation Request with numeric value '%"PRIu32"'\n", little_endian_read_32(packet, 8));
382                     printf("SSP User Confirmation Auto accept\n");
383                     break;
384 
385                 /* LISTING_RESUME */
386 
387                 case L2CAP_EVENT_CHANNEL_OPENED:
388                     status = packet[2];
389                     if (status){
390                         printf("L2CAP Connection failed: 0x%02x\n", status);
391                         break;
392                     }
393                     l2cap_cid  = little_endian_read_16(packet, 13);
394                     if (!l2cap_cid) break;
395                     if (l2cap_cid == l2cap_hid_control_cid){
396                         status = l2cap_create_channel(packet_handler, remote_addr, hid_interrupt_psm, 48, &l2cap_hid_interrupt_cid);
397                         if (status){
398                             printf("Connecting to HID Control failed: 0x%02x\n", status);
399                             break;
400                         }
401                     }
402                     if (l2cap_cid == l2cap_hid_interrupt_cid){
403                         printf("HID Connection established\n");
404                     }
405                     break;
406                 default:
407                     break;
408             }
409             break;
410         case L2CAP_DATA_PACKET:
411             // for now, just dump incoming data
412             if (channel == l2cap_hid_interrupt_cid){
413                 hid_host_handle_interrupt_report(packet,  size);
414             } else if (channel == l2cap_hid_control_cid){
415                 printf("HID Control: ");
416                 printf_hexdump(packet, size);
417             } else {
418                 break;
419             }
420         default:
421             break;
422     }
423 }
424 /* LISTING_END */
425 
426 int btstack_main(int argc, const char * argv[]);
427 int btstack_main(int argc, const char * argv[]){
428 
429     (void)argc;
430     (void)argv;
431 
432     hid_host_setup();
433 
434     // parse human readable Bluetooth address
435     sscanf_bd_addr(remote_addr_string, remote_addr);
436 
437     // Turn on the device
438     hci_power_control(HCI_POWER_ON);
439     return 0;
440 }
441 
442 /* EXAMPLE_END */
443