xref: /btstack/example/hid_host_demo.c (revision a8d51f092f1b660d0f6921369ad2bc3f9368296c)
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 Classic
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 L2CAP Services for reconnections
145     l2cap_register_service(packet_handler, PSM_HID_INTERRUPT, 0xffff, gap_get_security_level());
146     l2cap_register_service(packet_handler, PSM_HID_CONTROL, 0xffff, gap_get_security_level());
147 
148     // Allow sniff mode requests by HID device and support role switch
149     gap_set_default_link_policy_settings(LM_LINK_POLICY_ENABLE_SNIFF_MODE | LM_LINK_POLICY_ENABLE_ROLE_SWITCH);
150 
151     // try to become master on incoming connections
152     hci_set_master_slave_policy(HCI_ROLE_MASTER);
153 
154     // register for HCI events
155     hci_event_callback_registration.callback = &packet_handler;
156     hci_add_event_handler(&hci_event_callback_registration);
157 
158     // Disable stdout buffering
159     setbuf(stdout, NULL);
160 }
161 /* LISTING_END */
162 
163 /* @section SDP parser callback
164  *
165  * @text The SDP parsers retrieves the BNEP PAN UUID as explained in
166  * Section [on SDP BNEP Query example](#sec:sdpbnepqueryExample}.
167  */
168 
169 static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
170 
171     UNUSED(packet_type);
172     UNUSED(channel);
173     UNUSED(size);
174 
175     des_iterator_t attribute_list_it;
176     des_iterator_t additional_des_it;
177     des_iterator_t prot_it;
178     uint8_t       *des_element;
179     uint8_t       *element;
180     uint32_t       uuid;
181     uint8_t        status;
182 
183     switch (hci_event_packet_get_type(packet)){
184         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
185             if (sdp_event_query_attribute_byte_get_attribute_length(packet) <= attribute_value_buffer_size) {
186                 attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
187                 if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)) {
188                     switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) {
189                         case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST:
190                             for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
191                                 if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
192                                 des_element = des_iterator_get_element(&attribute_list_it);
193                                 des_iterator_init(&prot_it, des_element);
194                                 element = des_iterator_get_element(&prot_it);
195                                 if (!element) continue;
196                                 if (de_get_element_type(element) != DE_UUID) continue;
197                                 uuid = de_get_uuid32(element);
198                                 des_iterator_next(&prot_it);
199                                 switch (uuid){
200                                     case BLUETOOTH_PROTOCOL_L2CAP:
201                                         if (!des_iterator_has_more(&prot_it)) continue;
202                                         de_element_get_uint16(des_iterator_get_element(&prot_it), &hid_control_psm);
203                                         printf("HID Control PSM: 0x%04x\n", (int) hid_control_psm);
204                                         break;
205                                     default:
206                                         break;
207                                 }
208                             }
209                             break;
210                         case BLUETOOTH_ATTRIBUTE_ADDITIONAL_PROTOCOL_DESCRIPTOR_LISTS:
211                             for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
212                                 if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
213                                 des_element = des_iterator_get_element(&attribute_list_it);
214                                 for (des_iterator_init(&additional_des_it, des_element); des_iterator_has_more(&additional_des_it); des_iterator_next(&additional_des_it)) {
215                                     if (des_iterator_get_type(&additional_des_it) != DE_DES) continue;
216                                     des_element = des_iterator_get_element(&additional_des_it);
217                                     des_iterator_init(&prot_it, des_element);
218                                     element = des_iterator_get_element(&prot_it);
219                                     if (!element) continue;
220                                     if (de_get_element_type(element) != DE_UUID) continue;
221                                     uuid = de_get_uuid32(element);
222                                     des_iterator_next(&prot_it);
223                                     switch (uuid){
224                                         case BLUETOOTH_PROTOCOL_L2CAP:
225                                             if (!des_iterator_has_more(&prot_it)) continue;
226                                             de_element_get_uint16(des_iterator_get_element(&prot_it), &hid_interrupt_psm);
227                                             printf("HID Interrupt PSM: 0x%04x\n", (int) hid_interrupt_psm);
228                                             break;
229                                         default:
230                                             break;
231                                     }
232                                 }
233                             }
234                             break;
235                         case BLUETOOTH_ATTRIBUTE_HID_DESCRIPTOR_LIST:
236                             for (des_iterator_init(&attribute_list_it, attribute_value); des_iterator_has_more(&attribute_list_it); des_iterator_next(&attribute_list_it)) {
237                                 if (des_iterator_get_type(&attribute_list_it) != DE_DES) continue;
238                                 des_element = des_iterator_get_element(&attribute_list_it);
239                                 for (des_iterator_init(&additional_des_it, des_element); des_iterator_has_more(&additional_des_it); des_iterator_next(&additional_des_it)) {
240                                     if (des_iterator_get_type(&additional_des_it) != DE_STRING) continue;
241                                     element = des_iterator_get_element(&additional_des_it);
242                                     const uint8_t * descriptor = de_get_string(element);
243                                     hid_descriptor_len = de_get_data_size(element);
244                                     memcpy(hid_descriptor, descriptor, hid_descriptor_len);
245                                     printf("HID Descriptor:\n");
246                                     printf_hexdump(hid_descriptor, hid_descriptor_len);
247                                 }
248                             }
249                             break;
250                         default:
251                             break;
252                     }
253                 }
254             } else {
255                 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));
256             }
257             break;
258 
259         case SDP_EVENT_QUERY_COMPLETE:
260             if (sdp_event_query_complete_get_status(packet) != ERROR_CODE_SUCCESS){
261                 printf("SDP Query failed\n");
262                 break;
263             }
264             if ((l2cap_hid_interrupt_cid != 0) && (l2cap_hid_control_cid != 0)){
265                 printf("HID device re-connected\n");
266                 break;
267             }
268             if (!hid_control_psm) {
269                 hid_control_psm = BLUETOOTH_PSM_HID_CONTROL;
270                 printf("HID Control PSM missing, using default 0x%04x\n", hid_control_psm);
271             }
272             if (!hid_interrupt_psm) {
273                 hid_interrupt_psm = BLUETOOTH_PSM_HID_INTERRUPT;
274                 printf("HID Interrupt PSM missing, using default 0x%04x\n", hid_interrupt_psm);
275                 break;
276             }
277             printf("Setup HID\n");
278             status = l2cap_create_channel(packet_handler, remote_addr, hid_control_psm, 48, &l2cap_hid_control_cid);
279             if (status){
280                 printf("Connecting to HID Control failed: 0x%02x\n", status);
281             }
282             break;
283 
284         default:
285             break;
286     }
287 }
288 
289 /*
290  * @section HID Report Handler
291  *
292  * @text Use BTstack's compact HID Parser to process incoming HID Report
293  * Iterate over all fields and process fields with usage page = 0x07 / Keyboard
294  * Check if SHIFT is down and process first character (don't handle multiple key presses)
295  *
296  */
297 #define NUM_KEYS 6
298 static uint8_t last_keys[NUM_KEYS];
299 static void hid_host_handle_interrupt_report(const uint8_t * report, uint16_t report_len){
300     // check if HID Input Report
301     if (report_len < 1) return;
302     if (*report != 0xa1) return;
303     report++;
304     report_len--;
305     btstack_hid_parser_t parser;
306     btstack_hid_parser_init(&parser, hid_descriptor, hid_descriptor_len, HID_REPORT_TYPE_INPUT, report, report_len);
307     int shift = 0;
308     uint8_t new_keys[NUM_KEYS];
309     memset(new_keys, 0, sizeof(new_keys));
310     int     new_keys_count = 0;
311     while (btstack_hid_parser_has_more(&parser)){
312         uint16_t usage_page;
313         uint16_t usage;
314         int32_t  value;
315         btstack_hid_parser_get_field(&parser, &usage_page, &usage, &value);
316         if (usage_page != 0x07) continue;
317         switch (usage){
318             case 0xe1:
319             case 0xe6:
320                 if (value){
321                     shift = 1;
322                 }
323                 continue;
324             case 0x00:
325                 continue;
326             default:
327                 break;
328         }
329         if (usage >= sizeof(keytable_us_none)) continue;
330 
331         // store new keys
332         new_keys[new_keys_count++] = usage;
333 
334         // check if usage was used last time (and ignore in that case)
335         int i;
336         for (i=0;i<NUM_KEYS;i++){
337             if (usage == last_keys[i]){
338                 usage = 0;
339             }
340         }
341         if (usage == 0) continue;
342 
343         uint8_t key;
344         if (shift){
345             key = keytable_us_shift[usage];
346         } else {
347             key = keytable_us_none[usage];
348         }
349         if (key == CHAR_ILLEGAL) continue;
350         if (key == CHAR_BACKSPACE){
351             printf("\b \b");    // go back one char, print space, go back one char again
352             continue;
353         }
354         printf("%c", key);
355     }
356     memcpy(last_keys, new_keys, NUM_KEYS);
357 }
358 
359 /*
360  * @section Packet Handler
361  *
362  * @text The packet handler responds to various HCI Events.
363  */
364 
365 /* LISTING_START(packetHandler): Packet Handler */
366 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)
367 {
368     /* LISTING_PAUSE */
369     uint8_t   event;
370     bd_addr_t event_addr;
371     uint8_t   status;
372     uint16_t  l2cap_cid;
373 
374     /* LISTING_RESUME */
375     switch (packet_type) {
376 		case HCI_EVENT_PACKET:
377             event = hci_event_packet_get_type(packet);
378             switch (event) {
379                 /* @text When BTSTACK_EVENT_STATE with state HCI_STATE_WORKING
380                  * is received and the example is started in client mode, the remote SDP HID query is started.
381                  */
382                 case BTSTACK_EVENT_STATE:
383                     if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
384                         printf("Start SDP HID query for remote HID Device %s.\n", bd_addr_to_str(remote_addr));
385                         sdp_client_query_uuid16(&handle_sdp_client_query_result, remote_addr, BLUETOOTH_SERVICE_CLASS_HUMAN_INTERFACE_DEVICE_SERVICE);
386                     }
387                     break;
388 
389                 /* LISTING_PAUSE */
390                 case HCI_EVENT_PIN_CODE_REQUEST:
391 					// inform about pin code request
392                     printf("Pin code request - using '0000'\n");
393                     hci_event_pin_code_request_get_bd_addr(packet, event_addr);
394                     gap_pin_code_response(event_addr, "0000");
395 					break;
396 
397                 case HCI_EVENT_USER_CONFIRMATION_REQUEST:
398                     // inform about user confirmation request
399                     printf("SSP User Confirmation Request with numeric value '%"PRIu32"'\n", little_endian_read_32(packet, 8));
400                     printf("SSP User Confirmation Auto accept\n");
401                     break;
402 
403                 /* LISTING_RESUME */
404                 case L2CAP_EVENT_INCOMING_CONNECTION:
405                     l2cap_cid = l2cap_event_incoming_connection_get_local_cid(packet);
406                     switch (l2cap_event_incoming_connection_get_psm(packet)){
407                         case PSM_HID_CONTROL:
408                         case PSM_HID_INTERRUPT:
409                             l2cap_accept_connection(l2cap_cid);
410                             break;
411                         default:
412                             l2cap_decline_connection(l2cap_cid);
413                             break;
414                     }
415                     break;
416                 case L2CAP_EVENT_CHANNEL_OPENED:
417                     status = packet[2];
418                     if (status){
419                         printf("L2CAP Connection failed: 0x%02x\n", status);
420                         break;
421                     }
422                     l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet);
423                     switch (l2cap_event_channel_opened_get_psm(packet)){
424                         case PSM_HID_CONTROL:
425                             if (l2cap_event_channel_opened_get_incoming(packet) == 0) {
426                                 status = l2cap_create_channel(packet_handler, remote_addr, hid_interrupt_psm, 48, &l2cap_hid_interrupt_cid);
427                                 if (status){
428                                     printf("Connecting to HID Interrupt failed: 0x%02x\n", status);
429                                     break;
430                                 }
431                             }
432                             l2cap_hid_control_cid = l2cap_cid;
433                             break;
434                         case PSM_HID_INTERRUPT:
435                             l2cap_hid_interrupt_cid = l2cap_cid;
436                             break;
437                         default:
438                             break;
439                     }
440 
441                     if ((l2cap_hid_control_cid != 0) && (l2cap_hid_interrupt_cid != 0)){
442                         if (hid_descriptor_len == 0){
443                             printf("Start SDP HID query to get HID Descriptor\n");
444                             sdp_client_query_uuid16(&handle_sdp_client_query_result, remote_addr, BLUETOOTH_SERVICE_CLASS_HUMAN_INTERFACE_DEVICE_SERVICE);
445                         } else {
446                             printf("HID Connection established\n");
447                         }
448                     }
449                     break;
450                 case L2CAP_EVENT_CHANNEL_CLOSED:
451                     if ((l2cap_hid_control_cid != 0) && (l2cap_hid_interrupt_cid != 0)){
452                         printf("HID Connection closed\n");
453                         hid_descriptor_len = 0;
454                     }
455                     l2cap_cid = l2cap_event_channel_closed_get_local_cid(packet);
456                     if (l2cap_cid == l2cap_hid_control_cid){
457                         l2cap_hid_control_cid = 0;
458                     }
459                     if (l2cap_cid == l2cap_hid_interrupt_cid){
460                         l2cap_hid_interrupt_cid = 0;
461                     }
462                 default:
463                     break;
464             }
465             break;
466         case L2CAP_DATA_PACKET:
467             // for now, just dump incoming data
468             if (channel == l2cap_hid_interrupt_cid){
469                 hid_host_handle_interrupt_report(packet,  size);
470             } else if (channel == l2cap_hid_control_cid){
471                 printf("HID Control: ");
472                 printf_hexdump(packet, size);
473             } else {
474                 break;
475             }
476         default:
477             break;
478     }
479 }
480 /* LISTING_END */
481 
482 int btstack_main(int argc, const char * argv[]);
483 int btstack_main(int argc, const char * argv[]){
484 
485     (void)argc;
486     (void)argv;
487 
488     hid_host_setup();
489 
490     // parse human readable Bluetooth address
491     sscanf_bd_addr(remote_addr_string, remote_addr);
492 
493     // Turn on the device
494     hci_power_control(HCI_POWER_ON);
495     return 0;
496 }
497 
498 /* EXAMPLE_END */
499