xref: /btstack/src/hci.c (revision 6c927b22a98b3f4b0e3ed7d77829cb530efde76d)
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 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 /*
39  *  hci.c
40  *
41  *  Created by Matthias Ringwald on 4/29/09.
42  *
43  */
44 
45 #include "btstack_config.h"
46 
47 
48 #ifdef HAVE_TICK
49 #include "btstack_run_loop_embedded.h"
50 #endif
51 
52 #ifdef HAVE_PLATFORM_IPHONE_OS
53 #include "../port/ios/src/btstack_control_iphone.h"
54 #endif
55 
56 #ifdef ENABLE_BLE
57 #include "gap.h"
58 #endif
59 
60 #include <stdarg.h>
61 #include <string.h>
62 #include <stdio.h>
63 #include <inttypes.h>
64 
65 #include "btstack_debug.h"
66 #include "btstack_linked_list.h"
67 #include "btstack_memory.h"
68 #include "gap.h"
69 #include "hci.h"
70 #include "hci_cmd.h"
71 #include "hci_dump.h"
72 
73 
74 #define HCI_CONNECTION_TIMEOUT_MS 10000
75 
76 // prototypes
77 static void hci_update_scan_enable(void);
78 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
79 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
80 static void hci_connection_timestamp(hci_connection_t *connection);
81 static int  hci_power_control_on(void);
82 static void hci_power_control_off(void);
83 static void hci_state_reset(void);
84 static void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status);
85 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
86 static void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason);
87 static void hci_emit_nr_connections_changed(void);
88 static void hci_emit_hci_open_failed(void);
89 static void hci_emit_discoverable_enabled(uint8_t enabled);
90 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
91 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
92 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
93 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
94 static void hci_notify_if_sco_can_send_now(void);
95 static void hci_run(void);
96 static int  hci_is_le_connection(hci_connection_t * connection);
97 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
98 static int  hci_local_ssp_activated(void);
99 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
100 
101 #ifdef ENABLE_BLE
102 // called from test/ble_client/advertising_data_parser.c
103 void le_handle_advertisement_report(uint8_t *packet, int size);
104 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address);
105 #endif
106 
107 // the STACK is here
108 #ifndef HAVE_MALLOC
109 static hci_stack_t   hci_stack_static;
110 #endif
111 static hci_stack_t * hci_stack = NULL;
112 
113 // test helper
114 static uint8_t disable_l2cap_timeouts = 0;
115 
116 /**
117  * create connection for given address
118  *
119  * @return connection OR NULL, if no memory left
120  */
121 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
122     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
123     hci_connection_t * conn = btstack_memory_hci_connection_get();
124     if (!conn) return NULL;
125     memset(conn, 0, sizeof(hci_connection_t));
126     bd_addr_copy(conn->address, addr);
127     conn->address_type = addr_type;
128     conn->con_handle = 0xffff;
129     conn->authentication_flags = AUTH_FLAGS_NONE;
130     conn->bonding_flags = 0;
131     conn->requested_security_level = LEVEL_0;
132     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
133     btstack_run_loop_set_timer_context(&conn->timeout, conn);
134     hci_connection_timestamp(conn);
135     conn->acl_recombination_length = 0;
136     conn->acl_recombination_pos = 0;
137     conn->num_acl_packets_sent = 0;
138     conn->num_sco_packets_sent = 0;
139     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
140     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
141     return conn;
142 }
143 
144 
145 /**
146  * get le connection parameter range
147 *
148  * @return le connection parameter range struct
149  */
150 void gap_get_connection_parameter_range(le_connection_parameter_range_t range){
151     range = hci_stack->le_connection_parameter_range;
152 }
153 
154 /**
155  * set le connection parameter range
156  *
157  */
158 
159 void gap_set_connection_parameter_range(le_connection_parameter_range_t range){
160     hci_stack->le_connection_parameter_range = range;
161 }
162 
163 /**
164  * get hci connections iterator
165  *
166  * @return hci connections iterator
167  */
168 
169 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
170     btstack_linked_list_iterator_init(it, &hci_stack->connections);
171 }
172 
173 /**
174  * get connection for a given handle
175  *
176  * @return connection OR NULL, if not found
177  */
178 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
179     btstack_linked_list_iterator_t it;
180     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
181     while (btstack_linked_list_iterator_has_next(&it)){
182         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
183         if ( item->con_handle == con_handle ) {
184             return item;
185         }
186     }
187     return NULL;
188 }
189 
190 /**
191  * get connection for given address
192  *
193  * @return connection OR NULL, if not found
194  */
195 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t  addr, bd_addr_type_t addr_type){
196     btstack_linked_list_iterator_t it;
197     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
198     while (btstack_linked_list_iterator_has_next(&it)){
199         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
200         if (connection->address_type != addr_type)  continue;
201         if (memcmp(addr, connection->address, 6) != 0) continue;
202         return connection;
203     }
204     return NULL;
205 }
206 
207 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
208     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
209 #ifdef HAVE_TIME
210     struct timeval tv;
211     gettimeofday(&tv, NULL);
212     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
213         // connections might be timed out
214         hci_emit_l2cap_check_timeout(connection);
215     }
216 #endif
217 #ifdef HAVE_TICK
218     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
219         // connections might be timed out
220         hci_emit_l2cap_check_timeout(connection);
221     }
222 #endif
223 #ifdef HAVE_TIME_MS
224     if (btstack_run_loop_get_time_ms() > connection->timestamp + HCI_CONNECTION_TIMEOUT_MS){
225         // connections might be timed out
226         hci_emit_l2cap_check_timeout(connection);
227     }
228 #endif
229     btstack_run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
230     btstack_run_loop_add_timer(timer);
231 }
232 
233 static void hci_connection_timestamp(hci_connection_t *connection){
234 #ifdef HAVE_TIME
235     gettimeofday(&connection->timestamp, NULL);
236 #endif
237 #ifdef HAVE_TICK
238     connection->timestamp = btstack_run_loop_embedded_get_ticks();
239 #endif
240 #ifdef HAVE_TIME_MS
241     connection->timestamp = btstack_run_loop_get_time_ms();
242 #endif
243 }
244 
245 
246 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
247     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
248 }
249 
250 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
251     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
252 }
253 
254 
255 /**
256  * add authentication flags and reset timer
257  * @note: assumes classic connection
258  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
259  */
260 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
261     bd_addr_t addr;
262     reverse_bd_addr(bd_addr, addr);
263     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
264     if (conn) {
265         connectionSetAuthenticationFlags(conn, flags);
266         hci_connection_timestamp(conn);
267     }
268 }
269 
270 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
271     hci_connection_t * conn = hci_connection_for_handle(handle);
272     if (!conn) return 0;
273     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
274     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
275     return 0;
276 }
277 
278 void hci_drop_link_key_for_bd_addr(bd_addr_t addr){
279     if (hci_stack->link_key_db) {
280         hci_stack->link_key_db->delete_link_key(addr);
281     }
282 }
283 
284 static int hci_is_le_connection(hci_connection_t * connection){
285     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
286     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
287 }
288 
289 
290 /**
291  * count connections
292  */
293 static int nr_hci_connections(void){
294     int count = 0;
295     btstack_linked_item_t *it;
296     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
297     return count;
298 }
299 
300 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
301 
302     int num_packets_sent_classic = 0;
303     int num_packets_sent_le = 0;
304 
305     btstack_linked_item_t *it;
306     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
307         hci_connection_t * connection = (hci_connection_t *) it;
308         if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
309             num_packets_sent_classic += connection->num_acl_packets_sent;
310         } else {
311             num_packets_sent_le += connection->num_acl_packets_sent;
312         }
313     }
314 
315     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
316     int free_slots_le = 0;
317 
318     if (free_slots_classic < 0){
319         log_error("hci_number_free_acl_slots: outgoing classic packets (%u) > total classic packets (%u)", num_packets_sent_classic, hci_stack->acl_packets_total_num);
320         return 0;
321     }
322 
323     if (hci_stack->le_acl_packets_total_num){
324         // if we have LE slots, they are used
325         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
326         if (free_slots_le < 0){
327             log_error("hci_number_free_acl_slots: outgoing le packets (%u) > total le packets (%u)", num_packets_sent_le, hci_stack->le_acl_packets_total_num);
328             return 0;
329         }
330     } else {
331         // otherwise, classic slots are used for LE, too
332         free_slots_classic -= num_packets_sent_le;
333         if (free_slots_classic < 0){
334             log_error("hci_number_free_acl_slots: outgoing classic + le packets (%u + %u) > total packets (%u)", num_packets_sent_classic, num_packets_sent_le, hci_stack->acl_packets_total_num);
335             return 0;
336         }
337     }
338 
339     switch (address_type){
340         case BD_ADDR_TYPE_UNKNOWN:
341             log_error("hci_number_free_acl_slots: unknown address type");
342             return 0;
343 
344         case BD_ADDR_TYPE_CLASSIC:
345             return free_slots_classic;
346 
347         default:
348            if (hci_stack->le_acl_packets_total_num){
349                return free_slots_le;
350            }
351            return free_slots_classic;
352     }
353 }
354 
355 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
356     // get connection type
357     hci_connection_t * connection = hci_connection_for_handle(con_handle);
358     if (!connection){
359         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
360         return 0;
361     }
362     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
363 }
364 
365 static int hci_number_free_sco_slots(void){
366     int num_sco_packets_sent = 0;
367     btstack_linked_item_t *it;
368     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
369         hci_connection_t * connection = (hci_connection_t *) it;
370         num_sco_packets_sent += connection->num_sco_packets_sent;
371     }
372     if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
373         log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
374         return 0;
375     }
376     // log_info("hci_number_free_sco_slots u", handle, num_sco_packets_sent);
377     return hci_stack->sco_packets_total_num - num_sco_packets_sent;
378 }
379 
380 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
381 int hci_can_send_command_packet_now(void){
382     if (hci_stack->hci_packet_buffer_reserved) return 0;
383 
384     // check for async hci transport implementations
385     if (hci_stack->hci_transport->can_send_packet_now){
386         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
387             return 0;
388         }
389     }
390 
391     return hci_stack->num_cmd_packets > 0;
392 }
393 
394 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
395     // check for async hci transport implementations
396     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
397     return hci_stack->hci_transport->can_send_packet_now(packet_type);
398 }
399 
400 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
401     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
402     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
403 }
404 
405 int hci_can_send_acl_classic_packet_now(void){
406     if (hci_stack->hci_packet_buffer_reserved) return 0;
407     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_CLASSIC);
408 }
409 
410 int hci_can_send_acl_le_packet_now(void){
411     if (hci_stack->hci_packet_buffer_reserved) return 0;
412     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
413 }
414 
415 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
416     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
417     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
418 }
419 
420 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
421     if (hci_stack->hci_packet_buffer_reserved) return 0;
422     return hci_can_send_prepared_acl_packet_now(con_handle);
423 }
424 
425 int hci_can_send_prepared_sco_packet_now(void){
426     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) {
427         hci_stack->sco_waiting_for_can_send_now = 1;
428         return 0;
429     }
430     if (!hci_stack->synchronous_flow_control_enabled) return 1;
431     return hci_number_free_sco_slots() > 0;
432 }
433 
434 int hci_can_send_sco_packet_now(void){
435     if (hci_stack->hci_packet_buffer_reserved) {
436         hci_stack->sco_waiting_for_can_send_now = 1;
437         return 0;
438     }
439     return hci_can_send_prepared_sco_packet_now();
440 }
441 
442 // used for internal checks in l2cap.c
443 int hci_is_packet_buffer_reserved(void){
444     return hci_stack->hci_packet_buffer_reserved;
445 }
446 
447 // reserves outgoing packet buffer. @returns 1 if successful
448 int hci_reserve_packet_buffer(void){
449     if (hci_stack->hci_packet_buffer_reserved) {
450         log_error("hci_reserve_packet_buffer called but buffer already reserved");
451         return 0;
452     }
453     hci_stack->hci_packet_buffer_reserved = 1;
454     return 1;
455 }
456 
457 void hci_release_packet_buffer(void){
458     hci_stack->hci_packet_buffer_reserved = 0;
459 }
460 
461 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
462 static int hci_transport_synchronous(void){
463     return hci_stack->hci_transport->can_send_packet_now == NULL;
464 }
465 
466 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
467 
468     // log_info("hci_send_acl_packet_fragments  %u/%u (con 0x%04x)", hci_stack->acl_fragmentation_pos, hci_stack->acl_fragmentation_total_size, connection->con_handle);
469 
470     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
471     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
472     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
473         max_acl_data_packet_length = hci_stack->le_data_packets_length;
474     }
475 
476     // testing: reduce buffer to minimum
477     // max_acl_data_packet_length = 52;
478 
479     int err;
480     // multiple packets could be send on a synchronous HCI transport
481     while (1){
482 
483         // get current data
484         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
485         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
486         int more_fragments = 0;
487 
488         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
489         if (current_acl_data_packet_length > max_acl_data_packet_length){
490             more_fragments = 1;
491             current_acl_data_packet_length = max_acl_data_packet_length;
492         }
493 
494         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
495         if (acl_header_pos > 0){
496             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
497             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
498             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
499         }
500 
501         // update header len
502         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
503 
504         // count packet
505         connection->num_acl_packets_sent++;
506 
507         // send packet
508         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
509         const int size = current_acl_data_packet_length + 4;
510         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
511         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
512 
513         // done yet?
514         if (!more_fragments) break;
515 
516         // update start of next fragment to send
517         hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
518 
519         // can send more?
520         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
521     }
522 
523     // done
524     hci_stack->acl_fragmentation_pos = 0;
525     hci_stack->acl_fragmentation_total_size = 0;
526 
527     // release buffer now for synchronous transport
528     if (hci_transport_synchronous()){
529         hci_release_packet_buffer();
530         // notify upper stack that iit might be possible to send again
531         uint8_t event[] = { DAEMON_EVENT_HCI_PACKET_SENT, 0};
532         hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
533     }
534 
535     return err;
536 }
537 
538 // pre: caller has reserved the packet buffer
539 int hci_send_acl_packet_buffer(int size){
540 
541     // log_info("hci_send_acl_packet_buffer size %u", size);
542 
543     if (!hci_stack->hci_packet_buffer_reserved) {
544         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
545         return 0;
546     }
547 
548     uint8_t * packet = hci_stack->hci_packet_buffer;
549     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
550 
551     // check for free places on Bluetooth module
552     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
553         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
554         hci_release_packet_buffer();
555         return BTSTACK_ACL_BUFFERS_FULL;
556     }
557 
558     hci_connection_t *connection = hci_connection_for_handle( con_handle);
559     if (!connection) {
560         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
561         hci_release_packet_buffer();
562         return 0;
563     }
564     hci_connection_timestamp(connection);
565 
566     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
567 
568     // setup data
569     hci_stack->acl_fragmentation_total_size = size;
570     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
571 
572     return hci_send_acl_packet_fragments(connection);
573 }
574 
575 // pre: caller has reserved the packet buffer
576 int hci_send_sco_packet_buffer(int size){
577 
578     // log_info("hci_send_acl_packet_buffer size %u", size);
579 
580     if (!hci_stack->hci_packet_buffer_reserved) {
581         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
582         return 0;
583     }
584 
585     uint8_t * packet = hci_stack->hci_packet_buffer;
586 
587     // skip checks in loopback mode
588     if (!hci_stack->loopback_mode){
589         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
590 
591         // check for free places on Bluetooth module
592         if (!hci_can_send_prepared_sco_packet_now()) {
593             log_error("hci_send_sco_packet_buffer called but no free ACL buffers on controller");
594             hci_release_packet_buffer();
595             return BTSTACK_ACL_BUFFERS_FULL;
596         }
597 
598         // track send packet in connection struct
599         hci_connection_t *connection = hci_connection_for_handle( con_handle);
600         if (!connection) {
601             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
602             hci_release_packet_buffer();
603             return 0;
604         }
605         connection->num_sco_packets_sent++;
606     }
607 
608     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
609     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
610 
611     if (hci_transport_synchronous()){
612         hci_release_packet_buffer();
613         // notify upper stack that iit might be possible to send again
614         uint8_t event[] = { DAEMON_EVENT_HCI_PACKET_SENT, 0};
615         hci_emit_event(&event[0], sizeof(event), 0);    // don't dump
616     }
617 
618     return err;
619 }
620 
621 static void acl_handler(uint8_t *packet, int size){
622 
623     // log_info("acl_handler: size %u", size);
624 
625     // get info
626     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
627     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
628     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
629     uint16_t acl_length         = READ_ACL_LENGTH(packet);
630 
631     // ignore non-registered handle
632     if (!conn){
633         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
634         return;
635     }
636 
637     // assert packet is complete
638     if (acl_length + 4 != size){
639         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
640         return;
641     }
642 
643     // update idle timestamp
644     hci_connection_timestamp(conn);
645 
646     // handle different packet types
647     switch (acl_flags & 0x03) {
648 
649         case 0x01: // continuation fragment
650 
651             // sanity checks
652             if (conn->acl_recombination_pos == 0) {
653                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
654                 return;
655             }
656             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
657                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
658                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
659                 conn->acl_recombination_pos = 0;
660                 return;
661             }
662 
663             // append fragment payload (header already stored)
664             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
665             conn->acl_recombination_pos += acl_length;
666 
667             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
668             //        conn->acl_recombination_pos, conn->acl_recombination_length);
669 
670             // forward complete L2CAP packet if complete.
671             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
672                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
673                 // reset recombination buffer
674                 conn->acl_recombination_length = 0;
675                 conn->acl_recombination_pos = 0;
676             }
677             break;
678 
679         case 0x02: { // first fragment
680 
681             // sanity check
682             if (conn->acl_recombination_pos) {
683                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
684                 conn->acl_recombination_pos = 0;
685             }
686 
687             // peek into L2CAP packet!
688             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
689 
690             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
691 
692             // compare fragment size to L2CAP packet size
693             if (acl_length >= l2cap_length + 4){
694                 // forward fragment as L2CAP packet
695                 hci_emit_acl_packet(packet, acl_length + 4);
696             } else {
697 
698                 if (acl_length > HCI_ACL_BUFFER_SIZE){
699                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
700                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
701                     return;
702                 }
703 
704                 // store first fragment and tweak acl length for complete package
705                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
706                 conn->acl_recombination_pos    = acl_length + 4;
707                 conn->acl_recombination_length = l2cap_length;
708                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
709             }
710             break;
711 
712         }
713         default:
714             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
715             return;
716     }
717 
718     // execute main loop
719     hci_run();
720 }
721 
722 static void hci_shutdown_connection(hci_connection_t *conn){
723     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
724 
725     btstack_run_loop_remove_timer(&conn->timeout);
726 
727     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
728     btstack_memory_hci_connection_free( conn );
729 
730     // now it's gone
731     hci_emit_nr_connections_changed();
732 }
733 
734 static const uint16_t packet_type_sizes[] = {
735     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
736     HCI_ACL_DH1_SIZE, 0, 0, 0,
737     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
738     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
739 };
740 static const uint8_t  packet_type_feature_requirement_bit[] = {
741      0, // 3 slot packets
742      1, // 5 slot packets
743     25, // EDR 2 mpbs
744     26, // EDR 3 mbps
745     39, // 3 slot EDR packts
746     40, // 5 slot EDR packet
747 };
748 static const uint16_t packet_type_feature_packet_mask[] = {
749     0x0f00, // 3 slot packets
750     0xf000, // 5 slot packets
751     0x1102, // EDR 2 mpbs
752     0x2204, // EDR 3 mbps
753     0x0300, // 3 slot EDR packts
754     0x3000, // 5 slot EDR packet
755 };
756 
757 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
758     // enable packet types based on size
759     uint16_t packet_types = 0;
760     unsigned int i;
761     for (i=0;i<16;i++){
762         if (packet_type_sizes[i] == 0) continue;
763         if (packet_type_sizes[i] <= buffer_size){
764             packet_types |= 1 << i;
765         }
766     }
767     // disable packet types due to missing local supported features
768     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
769         int bit_idx = packet_type_feature_requirement_bit[i];
770         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
771         if (feature_set) continue;
772         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
773         packet_types &= ~packet_type_feature_packet_mask[i];
774     }
775     // flip bits for "may not be used"
776     packet_types ^= 0x3306;
777     return packet_types;
778 }
779 
780 uint16_t hci_usable_acl_packet_types(void){
781     return hci_stack->packet_types;
782 }
783 
784 uint8_t* hci_get_outgoing_packet_buffer(void){
785     // hci packet buffer is >= acl data packet length
786     return hci_stack->hci_packet_buffer;
787 }
788 
789 uint16_t hci_max_acl_data_packet_length(void){
790     return hci_stack->acl_data_packet_length;
791 }
792 
793 int hci_non_flushable_packet_boundary_flag_supported(void){
794     // No. 54, byte 6, bit 6
795     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
796 }
797 
798 static int hci_ssp_supported(void){
799     // No. 51, byte 6, bit 3
800     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
801 }
802 
803 static int hci_classic_supported(void){
804     // No. 37, byte 4, bit 5, = No BR/EDR Support
805     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
806 }
807 
808 static int hci_le_supported(void){
809 #ifdef ENABLE_BLE
810     // No. 37, byte 4, bit 6 = LE Supported (Controller)
811     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
812 #else
813     return 0;
814 #endif
815 }
816 
817 // get addr type and address used in advertisement packets
818 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t  addr){
819     *addr_type = hci_stack->adv_addr_type;
820     if (hci_stack->adv_addr_type){
821         memcpy(addr, hci_stack->adv_address, 6);
822     } else {
823         memcpy(addr, hci_stack->local_bd_addr, 6);
824     }
825 }
826 
827 #ifdef ENABLE_BLE
828 void le_handle_advertisement_report(uint8_t *packet, int size){
829     int offset = 3;
830     int num_reports = packet[offset];
831     offset += 1;
832 
833     int i;
834     log_info("HCI: handle adv report with num reports: %d", num_reports);
835     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
836     for (i=0; i<num_reports;i++){
837         uint8_t data_length = packet[offset + 8];
838         uint8_t event_size = 10 + data_length;
839         int pos = 0;
840         event[pos++] = GAP_LE_EVENT_ADVERTISING_REPORT;
841         event[pos++] = event_size;
842         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
843         offset += 8;
844         pos += 8;
845         event[pos++] = packet[offset + 1 + data_length]; // rssi
846         event[pos++] = packet[offset++]; //data_length;
847         memcpy(&event[pos], &packet[offset], data_length);
848         pos += data_length;
849         offset += data_length + 1; // rssi
850         hci_emit_event(event, pos, 1);
851     }
852 }
853 #endif
854 
855 static uint32_t hci_transport_uart_get_main_baud_rate(void){
856     if (!hci_stack->config) return 0;
857     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
858     // Limit baud rate for Broadcom chipsets to 3 mbps
859     if (hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION && baud_rate > 3000000){
860         baud_rate = 3000000;
861     }
862     return baud_rate;
863 }
864 
865 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
866     switch (hci_stack->substate){
867         case HCI_INIT_W4_SEND_RESET:
868             log_info("Resend HCI Reset");
869             hci_stack->substate = HCI_INIT_SEND_RESET;
870             hci_stack->num_cmd_packets = 1;
871             hci_run();
872             break;
873         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
874             log_info("Resend HCI Reset - CSR Warm Boot");
875             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
876             hci_stack->num_cmd_packets = 1;
877             hci_run();
878             break;
879         case HCI_INIT_W4_SEND_BAUD_CHANGE: {
880 			uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
881             log_info("Local baud rate change to %"PRIu32"(timeout handler)", baud_rate);
882             hci_stack->hci_transport->set_baudrate(baud_rate);
883             // For CSR, HCI Reset is sent on new baud rate
884             if (hci_stack->manufacturer == COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
885                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
886                 hci_run();
887             }
888             break;
889         }
890         default:
891             break;
892     }
893 }
894 
895 static void hci_initializing_next_state(void){
896     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
897 }
898 
899 // assumption: hci_can_send_command_packet_now() == true
900 static void hci_initializing_run(void){
901     log_info("hci_initializing_run: substate %u", hci_stack->substate);
902     switch (hci_stack->substate){
903         case HCI_INIT_SEND_RESET:
904             hci_state_reset();
905 
906 #ifndef HAVE_PLATFORM_IPHONE_OS
907             // prepare reset if command complete not received in 100ms
908             btstack_run_loop_set_timer(&hci_stack->timeout, 100);
909             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
910             btstack_run_loop_add_timer(&hci_stack->timeout);
911 #endif
912             // send command
913             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
914             hci_send_cmd(&hci_reset);
915             break;
916         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
917             hci_send_cmd(&hci_read_local_version_information);
918             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
919             break;
920         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
921             hci_state_reset();
922             // prepare reset if command complete not received in 100ms
923             btstack_run_loop_set_timer(&hci_stack->timeout, 100);
924             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
925             btstack_run_loop_add_timer(&hci_stack->timeout);
926             // send command
927             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
928             hci_send_cmd(&hci_reset);
929             break;
930         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
931             hci_state_reset();
932             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
933             hci_send_cmd(&hci_reset);
934             break;
935         case HCI_INIT_SEND_BAUD_CHANGE: {
936             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
937             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
938             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
939             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
940             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
941             // STLC25000D: baudrate change happens within 0.5 s after command was send,
942             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
943             if (hci_stack->manufacturer == COMPANY_ID_ST_MICROELECTRONICS){
944                 btstack_run_loop_set_timer(&hci_stack->timeout, 100);
945                 btstack_run_loop_add_timer(&hci_stack->timeout);
946             }
947             break;
948         }
949         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
950             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
951             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
952             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
953             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
954             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
955             break;
956         }
957         case HCI_INIT_CUSTOM_INIT:
958             log_info("Custom init");
959             // Custom initialization
960             if (hci_stack->chipset && hci_stack->chipset->next_command){
961                 int valid_cmd = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
962                 if (valid_cmd){
963                     int size = 3 + hci_stack->hci_packet_buffer[2];
964                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
965                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
966                     switch (valid_cmd) {
967                         case 1:
968                         default:
969                             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
970                             break;
971                         case 2: // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
972                             log_info("CSR Warm Boot");
973                             btstack_run_loop_set_timer(&hci_stack->timeout, 100);
974                             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
975                             btstack_run_loop_add_timer(&hci_stack->timeout);
976                             if (hci_stack->manufacturer == COMPANY_ID_CAMBRIDGE_SILICON_RADIO
977                                 && hci_stack->config
978                                 && hci_stack->chipset
979                                 // && hci_stack->chipset->set_baudrate_command -- there's no such command
980                                 && hci_stack->hci_transport->set_baudrate
981                                 && hci_transport_uart_get_main_baud_rate()){
982                                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
983                             } else {
984                                hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
985                             }
986                             break;
987                     }
988                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
989                     break;
990                 }
991                 log_info("hci_run: init script done");
992 
993                 // Init script download causes baud rate to reset on Broadcom chipsets, restore UART baud rate if needed
994                 if (hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION){
995                     int need_baud_change = hci_stack->config
996                         && hci_stack->chipset
997                         && hci_stack->chipset->set_baudrate_command
998                         && hci_stack->hci_transport->set_baudrate
999                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1000                     if (need_baud_change) {
1001                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1002                         log_info("Local baud rate change to %"PRIu32" after init script (bcm)", baud_rate);
1003                         hci_stack->hci_transport->set_baudrate(baud_rate);
1004                     }
1005                 }
1006             }
1007             // otherwise continue
1008             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1009             hci_send_cmd(&hci_read_local_supported_commands);
1010             break;
1011         case HCI_INIT_SET_BD_ADDR:
1012             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1013             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1014             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1015             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1016             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1017             break;
1018         case HCI_INIT_READ_BD_ADDR:
1019             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1020             hci_send_cmd(&hci_read_bd_addr);
1021             break;
1022         case HCI_INIT_READ_BUFFER_SIZE:
1023             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1024             hci_send_cmd(&hci_read_buffer_size);
1025             break;
1026         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1027             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1028             hci_send_cmd(&hci_read_local_supported_features);
1029             break;
1030         case HCI_INIT_SET_EVENT_MASK:
1031             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1032             if (hci_le_supported()){
1033                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1034             } else {
1035                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1036                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1037             }
1038             break;
1039         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1040             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1041             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1042             break;
1043         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1044             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1045             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1046             break;
1047         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1048             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1049             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1050             break;
1051         case HCI_INIT_WRITE_LOCAL_NAME:
1052             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1053             if (hci_stack->local_name){
1054                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
1055             } else {
1056                 char local_name[30];
1057                 // BTstack-11:22:33:44:55:66
1058                 strcpy(local_name, "BTstack ");
1059                 strcat(local_name, bd_addr_to_str(hci_stack->local_bd_addr));
1060                 log_info("---> Name %s", local_name);
1061                 hci_send_cmd(&hci_write_local_name, local_name);
1062             }
1063             break;
1064         case HCI_INIT_WRITE_SCAN_ENABLE:
1065             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1066             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1067             break;
1068         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1069             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1070             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1071             break;
1072 #ifdef ENABLE_BLE
1073         // LE INIT
1074         case HCI_INIT_LE_READ_BUFFER_SIZE:
1075             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1076             hci_send_cmd(&hci_le_read_buffer_size);
1077             break;
1078         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1079             // LE Supported Host = 1, Simultaneous Host = 0
1080             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1081             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1082             break;
1083         case HCI_INIT_READ_WHITE_LIST_SIZE:
1084             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1085             hci_send_cmd(&hci_le_read_white_list_size);
1086             break;
1087         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1088             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
1089             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1090             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
1091             break;
1092 #endif
1093         default:
1094             return;
1095     }
1096 }
1097 
1098 static void hci_init_done(void){
1099     // done. tell the app
1100     log_info("hci_init_done -> HCI_STATE_WORKING");
1101     hci_stack->state = HCI_STATE_WORKING;
1102     hci_emit_state();
1103     hci_run();
1104 }
1105 
1106 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
1107     uint8_t command_completed = 0;
1108 
1109     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
1110         uint16_t opcode = little_endian_read_16(packet,3);
1111         if (opcode == hci_stack->last_cmd_opcode){
1112             command_completed = 1;
1113             log_info("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1114         } else {
1115             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1116         }
1117     }
1118 
1119     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
1120         uint8_t  status = packet[2];
1121         uint16_t opcode = little_endian_read_16(packet,4);
1122         if (opcode == hci_stack->last_cmd_opcode){
1123             if (status){
1124                 command_completed = 1;
1125                 log_error("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1126             } else {
1127                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1128             }
1129         } else {
1130             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1131         }
1132     }
1133 
1134     // Vendor == CSR
1135     if (hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT && packet[0] == HCI_EVENT_VENDOR_SPECIFIC){
1136         // TODO: track actual command
1137         command_completed = 1;
1138     }
1139 
1140     // Vendor == Toshiba
1141     if (hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE && packet[0] == HCI_EVENT_VENDOR_SPECIFIC){
1142         // TODO: track actual command
1143         command_completed = 1;
1144     }
1145 
1146     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1147     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1148     //
1149     // HCI Reset
1150     // Timeout 100 ms
1151     // HCI Reset
1152     // Command Complete Reset
1153     // HCI Read Local Version Information
1154     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1155     // hang...
1156     //
1157     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1158     if (!command_completed
1159             && packet[0] == HCI_EVENT_COMMAND_COMPLETE
1160             && hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION){
1161 
1162         uint16_t opcode = little_endian_read_16(packet,3);
1163         if (opcode == hci_reset.opcode){
1164             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1165             return;
1166         }
1167     }
1168 
1169 
1170 
1171     if (!command_completed) return;
1172 
1173     int need_baud_change = hci_stack->config
1174                         && hci_stack->chipset
1175                         && hci_stack->chipset->set_baudrate_command
1176                         && hci_stack->hci_transport->set_baudrate
1177                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1178 
1179     int need_addr_change = hci_stack->custom_bd_addr_set
1180                         && hci_stack->chipset
1181                         && hci_stack->chipset->set_bd_addr_command;
1182 
1183     switch(hci_stack->substate){
1184         case HCI_INIT_W4_SEND_RESET:
1185             btstack_run_loop_remove_timer(&hci_stack->timeout);
1186             break;
1187         case HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION:
1188             log_info("Received local version info, need baud change %u", need_baud_change);
1189             if (need_baud_change){
1190                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1191                 return;
1192             }
1193             // skip baud change
1194             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1195             return;
1196         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1197             // for STLC2500D, baud rate change already happened.
1198             // for others, baud rate gets changed now
1199             if (hci_stack->manufacturer != COMPANY_ID_ST_MICROELECTRONICS){
1200                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1201                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change)", baud_rate);
1202                 hci_stack->hci_transport->set_baudrate(baud_rate);
1203             }
1204             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1205             return;
1206         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1207             btstack_run_loop_remove_timer(&hci_stack->timeout);
1208             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1209             return;
1210         case HCI_INIT_W4_CUSTOM_INIT:
1211             // repeat custom init
1212             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1213             return;
1214         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1215             if (need_baud_change && hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION){
1216                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1217                 return;
1218             }
1219             if (need_addr_change){
1220                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1221                 return;
1222             }
1223             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1224             return;
1225         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM: {
1226             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1227             log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change_bcm))", baud_rate);
1228             hci_stack->hci_transport->set_baudrate(baud_rate);
1229             if (need_addr_change){
1230                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1231                 return;
1232             }
1233             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1234             return;
1235         }
1236         case HCI_INIT_W4_SET_BD_ADDR:
1237             // for STLC2500D, bd addr change only gets active after sending reset command
1238             if (hci_stack->manufacturer == COMPANY_ID_ST_MICROELECTRONICS){
1239                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1240                 return;
1241             }
1242             // skipping st warm boot
1243             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1244             return;
1245         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1246             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1247             return;
1248         case HCI_INIT_W4_READ_BD_ADDR:
1249             // only read buffer size if supported
1250             if (hci_stack->local_supported_commands[0] & 0x01) {
1251                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1252                 return;
1253             }
1254             // skipping read buffer size
1255             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1256             return;
1257         case HCI_INIT_W4_SET_EVENT_MASK:
1258             // skip Classic init commands for LE only chipsets
1259             if (!hci_classic_supported()){
1260                 if (hci_le_supported()){
1261                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1262                     return;
1263                 } else {
1264                     log_error("Neither BR/EDR nor LE supported");
1265                     hci_init_done();
1266                     return;
1267                 }
1268             }
1269             if (!hci_ssp_supported()){
1270                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1271                 return;
1272             }
1273             break;
1274         case HCI_INIT_W4_WRITE_PAGE_TIMEOUT:
1275             break;
1276         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1277             // skip write le host if not supported (e.g. on LE only EM9301)
1278             if (hci_stack->local_supported_commands[0] & 0x02) break;
1279             hci_stack->substate = HCI_INIT_LE_SET_SCAN_PARAMETERS;
1280             return;
1281 
1282 #ifdef HAVE_SCO_OVER_HCI
1283         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1284             // just go to next state
1285             break;
1286         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1287             if (!hci_le_supported()){
1288                 // SKIP LE init for Classic only configuration
1289                 hci_init_done();
1290                 return;
1291             }
1292             break;
1293 #else
1294         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1295             if (!hci_le_supported()){
1296                 // SKIP LE init for Classic only configuration
1297                 hci_init_done();
1298                 return;
1299             }
1300 #endif
1301             break;
1302         // Response to command before init done state -> init done
1303         case (HCI_INIT_DONE-1):
1304             hci_init_done();
1305             return;
1306 
1307         default:
1308             break;
1309     }
1310     hci_initializing_next_state();
1311 }
1312 
1313 static void event_handler(uint8_t *packet, int size){
1314 
1315     uint16_t event_length = packet[1];
1316 
1317     // assert packet is complete
1318     if (size != event_length + 2){
1319         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
1320         return;
1321     }
1322 
1323     bd_addr_t addr;
1324     bd_addr_type_t addr_type;
1325     uint8_t link_type;
1326     hci_con_handle_t handle;
1327     hci_connection_t * conn;
1328     int i;
1329 
1330     // log_info("HCI:EVENT:%02x", packet[0]);
1331 
1332     switch (packet[0]) {
1333 
1334         case HCI_EVENT_COMMAND_COMPLETE:
1335             // get num cmd packets
1336             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
1337             hci_stack->num_cmd_packets = packet[2];
1338 
1339             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_buffer_size)){
1340                 // from offset 5
1341                 // status
1342                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
1343                 hci_stack->acl_data_packet_length = little_endian_read_16(packet, 6);
1344                 hci_stack->sco_data_packet_length = packet[8];
1345                 hci_stack->acl_packets_total_num  = little_endian_read_16(packet, 9);
1346                 hci_stack->sco_packets_total_num  = little_endian_read_16(packet, 11);
1347 
1348                 if (hci_stack->state == HCI_STATE_INITIALIZING){
1349                     // determine usable ACL payload size
1350                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
1351                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1352                     }
1353                     log_info("hci_read_buffer_size: acl used size %u, count %u / sco size %u, count %u",
1354                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
1355                              hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
1356                 }
1357             }
1358 #ifdef ENABLE_BLE
1359             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_buffer_size)){
1360                 hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
1361                 hci_stack->le_acl_packets_total_num  = packet[8];
1362                     // determine usable ACL payload size
1363                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1364                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1365                     }
1366                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1367             }
1368             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_white_list_size)){
1369                 hci_stack->le_whitelist_capacity = little_endian_read_16(packet, 6);
1370                 log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
1371             }
1372 #endif
1373             // Dump local address
1374             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)) {
1375                 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1],
1376 				hci_stack->local_bd_addr);
1377                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1378                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1379             }
1380             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
1381                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1382             }
1383             // Note: HCI init checks
1384             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_features)){
1385                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1386 
1387                 // determine usable ACL packet types based on host buffer size and supported features
1388                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1389                 log_info("packet types %04x", hci_stack->packet_types);
1390 
1391                 // Classic/LE
1392                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1393             }
1394             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_version_information)){
1395                 // hci_stack->hci_version    = little_endian_read_16(packet, 4);
1396                 // hci_stack->hci_revision   = little_endian_read_16(packet, 6);
1397                 // hci_stack->lmp_version    = little_endian_read_16(packet, 8);
1398                 hci_stack->manufacturer   = little_endian_read_16(packet, 10);
1399                 // hci_stack->lmp_subversion = little_endian_read_16(packet, 12);
1400                 log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
1401             }
1402             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){
1403                 hci_stack->local_supported_commands[0] =
1404                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+14] & 0X80) >> 7 |  // Octet 14, bit 7
1405                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+24] & 0x40) >> 5;   // Octet 24, bit 6
1406             }
1407             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_synchronous_flow_control_enable)){
1408                 if (packet[5] == 0){
1409                     hci_stack->synchronous_flow_control_enabled = 1;
1410                 }
1411             }
1412             break;
1413 
1414         case HCI_EVENT_COMMAND_STATUS:
1415             // get num cmd packets
1416             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1417             hci_stack->num_cmd_packets = packet[3];
1418             break;
1419 
1420         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1421             int offset = 3;
1422             for (i=0; i<packet[2];i++){
1423                 handle = little_endian_read_16(packet, offset);
1424                 offset += 2;
1425                 uint16_t num_packets = little_endian_read_16(packet, offset);
1426                 offset += 2;
1427 
1428                 conn = hci_connection_for_handle(handle);
1429                 if (!conn){
1430                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1431                     continue;
1432                 }
1433 
1434                 if (conn->address_type == BD_ADDR_TYPE_SCO){
1435                     if (conn->num_sco_packets_sent >= num_packets){
1436                         conn->num_sco_packets_sent -= num_packets;
1437                     } else {
1438                         log_error("hci_number_completed_packets, more sco slots freed then sent.");
1439                         conn->num_sco_packets_sent = 0;
1440                     }
1441                     hci_notify_if_sco_can_send_now();
1442                 } else {
1443                     if (conn->num_acl_packets_sent >= num_packets){
1444                         conn->num_acl_packets_sent -= num_packets;
1445                     } else {
1446                         log_error("hci_number_completed_packets, more acl slots freed then sent.");
1447                         conn->num_acl_packets_sent = 0;
1448                     }
1449                 }
1450                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1451             }
1452             break;
1453         }
1454         case HCI_EVENT_CONNECTION_REQUEST:
1455             reverse_bd_addr(&packet[2], addr);
1456             // TODO: eval COD 8-10
1457             link_type = packet[11];
1458             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1459             addr_type = link_type == 1 ? BD_ADDR_TYPE_CLASSIC : BD_ADDR_TYPE_SCO;
1460             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1461             if (!conn) {
1462                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1463             }
1464             if (!conn) {
1465                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1466                 hci_stack->decline_reason = 0x0d;
1467                 bd_addr_copy(hci_stack->decline_addr, addr);
1468                 break;
1469             }
1470             conn->role  = HCI_ROLE_SLAVE;
1471             conn->state = RECEIVED_CONNECTION_REQUEST;
1472             // store info about eSCO
1473             if (link_type == 0x02){
1474                 conn->remote_supported_feature_eSCO = 1;
1475             }
1476             hci_run();
1477             break;
1478 
1479         case HCI_EVENT_CONNECTION_COMPLETE:
1480             // Connection management
1481             reverse_bd_addr(&packet[5], addr);
1482             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1483             addr_type = BD_ADDR_TYPE_CLASSIC;
1484             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1485             if (conn) {
1486                 if (!packet[2]){
1487                     conn->state = OPEN;
1488                     conn->con_handle = little_endian_read_16(packet, 3);
1489                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1490 
1491                     // restart timer
1492                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1493                     btstack_run_loop_add_timer(&conn->timeout);
1494 
1495                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1496 
1497                     hci_emit_nr_connections_changed();
1498                 } else {
1499                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1500                     uint8_t status = packet[2];
1501                     bd_addr_t bd_address;
1502                     memcpy(&bd_address, conn->address, 6);
1503 
1504                     // connection failed, remove entry
1505                     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1506                     btstack_memory_hci_connection_free( conn );
1507 
1508                     // notify client if dedicated bonding
1509                     if (notify_dedicated_bonding_failed){
1510                         log_info("hci notify_dedicated_bonding_failed");
1511                         hci_emit_dedicated_bonding_result(bd_address, status);
1512                     }
1513 
1514                     // if authentication error, also delete link key
1515                     if (packet[2] == 0x05) {
1516                         hci_drop_link_key_for_bd_addr(addr);
1517                     }
1518                 }
1519             }
1520             break;
1521 
1522         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
1523             reverse_bd_addr(&packet[5], addr);
1524             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1525             if (packet[2]){
1526                 // connection failed
1527                 break;
1528             }
1529             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1530             if (!conn) {
1531                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1532             }
1533             if (!conn) {
1534                 break;
1535             }
1536             conn->state = OPEN;
1537             conn->con_handle = little_endian_read_16(packet, 3);
1538             break;
1539 
1540         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1541             handle = little_endian_read_16(packet, 3);
1542             conn = hci_connection_for_handle(handle);
1543             if (!conn) break;
1544             if (!packet[2]){
1545                 uint8_t * features = &packet[5];
1546                 if (features[6] & (1 << 3)){
1547                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1548                 }
1549                 if (features[3] & (1<<7)){
1550                     conn->remote_supported_feature_eSCO = 1;
1551                 }
1552             }
1553             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1554             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x, eSCO %u", conn->bonding_flags, conn->remote_supported_feature_eSCO);
1555             if (conn->bonding_flags & BONDING_DEDICATED){
1556                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1557             }
1558             break;
1559 
1560         case HCI_EVENT_LINK_KEY_REQUEST:
1561             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1562             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1563             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1564             if (hci_stack->bondable && !hci_stack->link_key_db) break;
1565             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1566             hci_run();
1567             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1568             return;
1569 
1570         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1571             reverse_bd_addr(&packet[2], addr);
1572             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1573             if (!conn) break;
1574             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1575             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1576             // Change Connection Encryption keeps link key type
1577             if (link_key_type != CHANGED_COMBINATION_KEY){
1578                 conn->link_key_type = link_key_type;
1579             }
1580             if (!hci_stack->link_key_db) break;
1581             hci_stack->link_key_db->put_link_key(addr, &packet[8], conn->link_key_type);
1582             // still forward event to allow dismiss of pairing dialog
1583             break;
1584         }
1585 
1586         case HCI_EVENT_PIN_CODE_REQUEST:
1587             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1588             // non-bondable mode: pin code negative reply will be sent
1589             if (!hci_stack->bondable){
1590                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1591                 hci_run();
1592                 return;
1593             }
1594             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1595             if (!hci_stack->link_key_db) break;
1596             reverse_bd_addr(&packet[2], addr);
1597             hci_stack->link_key_db->delete_link_key(addr);
1598             break;
1599 
1600         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1601             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1602             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1603             break;
1604 
1605         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1606             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1607             if (!hci_stack->ssp_auto_accept) break;
1608             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1609             break;
1610 
1611         case HCI_EVENT_USER_PASSKEY_REQUEST:
1612             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1613             if (!hci_stack->ssp_auto_accept) break;
1614             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1615             break;
1616 
1617         case HCI_EVENT_ENCRYPTION_CHANGE:
1618             handle = little_endian_read_16(packet, 3);
1619             conn = hci_connection_for_handle(handle);
1620             if (!conn) break;
1621             if (packet[2] == 0) {
1622                 if (packet[5]){
1623                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1624                 } else {
1625                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1626                 }
1627             }
1628             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1629             break;
1630 
1631         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1632             handle = little_endian_read_16(packet, 3);
1633             conn = hci_connection_for_handle(handle);
1634             if (!conn) break;
1635 
1636             // dedicated bonding: send result and disconnect
1637             if (conn->bonding_flags & BONDING_DEDICATED){
1638                 conn->bonding_flags &= ~BONDING_DEDICATED;
1639                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1640                 conn->bonding_status = packet[2];
1641                 break;
1642             }
1643 
1644             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1645                 // link key sufficient for requested security
1646                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1647                 break;
1648             }
1649             // not enough
1650             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1651             break;
1652 
1653         // HCI_EVENT_DISCONNECTION_COMPLETE
1654         // has been split, to first notify stack before shutting connection down
1655         // see end of function, too.
1656         case HCI_EVENT_DISCONNECTION_COMPLETE:
1657             if (packet[2]) break;   // status != 0
1658             handle = little_endian_read_16(packet, 3);
1659             conn = hci_connection_for_handle(handle);
1660             if (!conn) break;       // no conn struct anymore
1661             // re-enable advertisements for le connections if active
1662             if (hci_is_le_connection(conn) && hci_stack->le_advertisements_enabled){
1663                 hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
1664             }
1665             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1666             break;
1667 
1668         case HCI_EVENT_HARDWARE_ERROR:
1669             if (hci_stack->hardware_error_callback){
1670                 (*hci_stack->hardware_error_callback)();
1671             } else {
1672                 // if no special requests, just reboot stack
1673                 hci_power_control_off();
1674                 hci_power_control_on();
1675             }
1676             break;
1677 
1678         case HCI_EVENT_ROLE_CHANGE:
1679             if (packet[2]) break;   // status != 0
1680             handle = little_endian_read_16(packet, 3);
1681             conn = hci_connection_for_handle(handle);
1682             if (!conn) break;       // no conn
1683             conn->role = packet[9];
1684             break;
1685 
1686         case DAEMON_EVENT_HCI_PACKET_SENT:
1687             // release packet buffer only for asynchronous transport and if there are not further fragements
1688             if (hci_transport_synchronous()) {
1689                 log_error("Synchronous HCI Transport shouldn't send DAEMON_EVENT_HCI_PACKET_SENT");
1690                 return; // instead of break: to avoid re-entering hci_run()
1691             }
1692             if (hci_stack->acl_fragmentation_total_size) break;
1693             hci_release_packet_buffer();
1694 
1695             // L2CAP receives this event via the hci_add_event_handler
1696             // For SCO, we do the can send now check here
1697             hci_notify_if_sco_can_send_now();
1698             break;
1699 
1700 #ifdef ENABLE_BLE
1701         case HCI_EVENT_LE_META:
1702             switch (packet[2]){
1703                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1704                     log_info("advertising report received");
1705                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1706                     le_handle_advertisement_report(packet, size);
1707                     break;
1708                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1709                     // Connection management
1710                     reverse_bd_addr(&packet[8], addr);
1711                     addr_type = (bd_addr_type_t)packet[7];
1712                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1713                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1714                     // if auto-connect, remove from whitelist in both roles
1715                     if (hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST){
1716                         hci_remove_from_whitelist(addr_type, addr);
1717                     }
1718                     // handle error: error is reported only to the initiator -> outgoing connection
1719                     if (packet[3]){
1720                         // outgoing connection establishment is done
1721                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1722                         // remove entry
1723                         if (conn){
1724                             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1725                             btstack_memory_hci_connection_free( conn );
1726                         }
1727                         break;
1728                     }
1729                     // on success, both hosts receive connection complete event
1730                     if (packet[6] == HCI_ROLE_MASTER){
1731                         // if we're master, it was an outgoing connection and we're done with it
1732                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1733                     } else {
1734                         // if we're slave, it was an incoming connection, advertisements have stopped
1735                         hci_stack->le_advertisements_active = 0;
1736                     }
1737                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1738                     if (!conn){
1739                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1740                     }
1741                     // no memory, sorry.
1742                     if (!conn){
1743                         break;
1744                     }
1745 
1746                     conn->state = OPEN;
1747                     conn->role  = packet[6];
1748                     conn->con_handle = little_endian_read_16(packet, 4);
1749 
1750                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1751 
1752                     // restart timer
1753                     // btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1754                     // btstack_run_loop_add_timer(&conn->timeout);
1755 
1756                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1757 
1758                     hci_emit_nr_connections_changed();
1759                     break;
1760 
1761             // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
1762 
1763                 default:
1764                     break;
1765             }
1766             break;
1767 #endif
1768         default:
1769             break;
1770     }
1771 
1772     // handle BT initialization
1773     if (hci_stack->state == HCI_STATE_INITIALIZING){
1774         hci_initializing_event_handler(packet, size);
1775     }
1776 
1777     // help with BT sleep
1778     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1779         && hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE
1780         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
1781         hci_initializing_next_state();
1782     }
1783 
1784     // notify upper stack
1785 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
1786 
1787     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1788     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1789         if (!packet[2]){
1790             handle = little_endian_read_16(packet, 3);
1791             hci_connection_t * aConn = hci_connection_for_handle(handle);
1792             if (aConn) {
1793                 uint8_t status = aConn->bonding_status;
1794                 uint16_t flags = aConn->bonding_flags;
1795                 bd_addr_t bd_address;
1796                 memcpy(&bd_address, aConn->address, 6);
1797                 hci_shutdown_connection(aConn);
1798                 // connection struct is gone, don't access anymore
1799                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1800                     hci_emit_dedicated_bonding_result(bd_address, status);
1801                 }
1802             }
1803         }
1804     }
1805 
1806 	// execute main loop
1807 	hci_run();
1808 }
1809 
1810 static void sco_handler(uint8_t * packet, uint16_t size){
1811     if (!hci_stack->sco_packet_handler) return;
1812     hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, packet, size);
1813 }
1814 
1815 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1816     hci_dump_packet(packet_type, 1, packet, size);
1817     switch (packet_type) {
1818         case HCI_EVENT_PACKET:
1819             event_handler(packet, size);
1820             break;
1821         case HCI_ACL_DATA_PACKET:
1822             acl_handler(packet, size);
1823             break;
1824         case HCI_SCO_DATA_PACKET:
1825             sco_handler(packet, size);
1826         default:
1827             break;
1828     }
1829 }
1830 
1831 /**
1832  * @brief Add event packet handler.
1833  */
1834 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
1835     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
1836 }
1837 
1838 
1839 /** Register HCI packet handlers */
1840 void hci_register_acl_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1841     hci_stack->acl_packet_handler = handler;
1842 }
1843 
1844 /**
1845  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
1846  */
1847 void hci_register_sco_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1848     hci_stack->sco_packet_handler = handler;
1849 }
1850 
1851 static void hci_state_reset(void){
1852     // no connections yet
1853     hci_stack->connections = NULL;
1854 
1855     // keep discoverable/connectable as this has been requested by the client(s)
1856     // hci_stack->discoverable = 0;
1857     // hci_stack->connectable = 0;
1858     // hci_stack->bondable = 1;
1859 
1860     // buffer is free
1861     hci_stack->hci_packet_buffer_reserved = 0;
1862 
1863     // no pending cmds
1864     hci_stack->decline_reason = 0;
1865     hci_stack->new_scan_enable_value = 0xff;
1866 
1867     // LE
1868     hci_stack->adv_addr_type = 0;
1869     memset(hci_stack->adv_address, 0, 6);
1870     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1871     hci_stack->le_scan_type = 0xff;
1872     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1873     hci_stack->le_whitelist = 0;
1874     hci_stack->le_whitelist_capacity = 0;
1875     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
1876     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
1877     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
1878     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
1879     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
1880     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
1881 }
1882 
1883 /**
1884  * @brief Configure Bluetooth hardware control. Has to be called before power on.
1885  */
1886 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
1887     // store and open remote device db
1888     hci_stack->link_key_db = link_key_db;
1889     if (hci_stack->link_key_db) {
1890         hci_stack->link_key_db->open();
1891     }
1892 }
1893 
1894 void hci_init(const hci_transport_t *transport, const void *config){
1895 
1896 #ifdef HAVE_MALLOC
1897     if (!hci_stack) {
1898         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1899     }
1900 #else
1901     hci_stack = &hci_stack_static;
1902 #endif
1903     memset(hci_stack, 0, sizeof(hci_stack_t));
1904 
1905     // reference to use transport layer implementation
1906     hci_stack->hci_transport = transport;
1907 
1908     // reference to used config
1909     hci_stack->config = config;
1910 
1911     // max acl payload size defined in config.h
1912     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1913 
1914     // register packet handlers with transport
1915     transport->register_packet_handler(&packet_handler);
1916 
1917     hci_stack->state = HCI_STATE_OFF;
1918 
1919     // class of device
1920     hci_stack->class_of_device = 0x007a020c; // Smartphone
1921 
1922     // bondable by default
1923     hci_stack->bondable = 1;
1924 
1925     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1926     hci_stack->ssp_enable = 1;
1927     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1928     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1929     hci_stack->ssp_auto_accept = 1;
1930 
1931     // voice setting - signed 8 bit pcm data with CVSD over the air
1932     hci_stack->sco_voice_setting = 0x40;
1933 
1934     hci_state_reset();
1935 }
1936 
1937 /**
1938  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
1939  */
1940 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
1941     hci_stack->chipset = chipset_driver;
1942 
1943     // reset chipset driver - init is also called on power_up
1944     if (hci_stack->chipset && hci_stack->chipset->init){
1945         hci_stack->chipset->init(hci_stack->config);
1946     }
1947 }
1948 
1949 /**
1950  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
1951  */
1952 void hci_set_control(const btstack_control_t *hardware_control){
1953     // references to used control implementation
1954     hci_stack->control = hardware_control;
1955     // init with transport config
1956     hardware_control->init(hci_stack->config);
1957 }
1958 
1959 void hci_close(void){
1960     // close remote device db
1961     if (hci_stack->link_key_db) {
1962         hci_stack->link_key_db->close();
1963     }
1964     while (hci_stack->connections) {
1965         // cancel all l2cap connections
1966         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1967         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1968     }
1969     hci_power_control(HCI_POWER_OFF);
1970 
1971 #ifdef HAVE_MALLOC
1972     free(hci_stack);
1973 #endif
1974     hci_stack = NULL;
1975 }
1976 
1977 void hci_set_class_of_device(uint32_t class_of_device){
1978     hci_stack->class_of_device = class_of_device;
1979 }
1980 
1981 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
1982 void hci_set_bd_addr(bd_addr_t addr){
1983     memcpy(hci_stack->custom_bd_addr, addr, 6);
1984     hci_stack->custom_bd_addr_set = 1;
1985 }
1986 
1987 void hci_disable_l2cap_timeout_check(void){
1988     disable_l2cap_timeouts = 1;
1989 }
1990 // State-Module-Driver overview
1991 // state                    module  low-level
1992 // HCI_STATE_OFF             off      close
1993 // HCI_STATE_INITIALIZING,   on       open
1994 // HCI_STATE_WORKING,        on       open
1995 // HCI_STATE_HALTING,        on       open
1996 // HCI_STATE_SLEEPING,    off/sleep   close
1997 // HCI_STATE_FALLING_ASLEEP  on       open
1998 
1999 static int hci_power_control_on(void){
2000 
2001     // power on
2002     int err = 0;
2003     if (hci_stack->control && hci_stack->control->on){
2004         err = (*hci_stack->control->on)();
2005     }
2006     if (err){
2007         log_error( "POWER_ON failed");
2008         hci_emit_hci_open_failed();
2009         return err;
2010     }
2011 
2012     // int chipset driver
2013     if (hci_stack->chipset && hci_stack->chipset->init){
2014         hci_stack->chipset->init(hci_stack->config);
2015     }
2016 
2017     // init transport
2018     if (hci_stack->hci_transport->init){
2019         hci_stack->hci_transport->init(hci_stack->config);
2020     }
2021 
2022     // open transport
2023     err = hci_stack->hci_transport->open();
2024     if (err){
2025         log_error( "HCI_INIT failed, turning Bluetooth off again");
2026         if (hci_stack->control && hci_stack->control->off){
2027             (*hci_stack->control->off)();
2028         }
2029         hci_emit_hci_open_failed();
2030         return err;
2031     }
2032     return 0;
2033 }
2034 
2035 static void hci_power_control_off(void){
2036 
2037     log_info("hci_power_control_off");
2038 
2039     // close low-level device
2040     hci_stack->hci_transport->close();
2041 
2042     log_info("hci_power_control_off - hci_transport closed");
2043 
2044     // power off
2045     if (hci_stack->control && hci_stack->control->off){
2046         (*hci_stack->control->off)();
2047     }
2048 
2049     log_info("hci_power_control_off - control closed");
2050 
2051     hci_stack->state = HCI_STATE_OFF;
2052 }
2053 
2054 static void hci_power_control_sleep(void){
2055 
2056     log_info("hci_power_control_sleep");
2057 
2058 #if 0
2059     // don't close serial port during sleep
2060 
2061     // close low-level device
2062     hci_stack->hci_transport->close(hci_stack->config);
2063 #endif
2064 
2065     // sleep mode
2066     if (hci_stack->control && hci_stack->control->sleep){
2067         (*hci_stack->control->sleep)();
2068     }
2069 
2070     hci_stack->state = HCI_STATE_SLEEPING;
2071 }
2072 
2073 static int hci_power_control_wake(void){
2074 
2075     log_info("hci_power_control_wake");
2076 
2077     // wake on
2078     if (hci_stack->control && hci_stack->control->wake){
2079         (*hci_stack->control->wake)();
2080     }
2081 
2082 #if 0
2083     // open low-level device
2084     int err = hci_stack->hci_transport->open(hci_stack->config);
2085     if (err){
2086         log_error( "HCI_INIT failed, turning Bluetooth off again");
2087         if (hci_stack->control && hci_stack->control->off){
2088             (*hci_stack->control->off)();
2089         }
2090         hci_emit_hci_open_failed();
2091         return err;
2092     }
2093 #endif
2094 
2095     return 0;
2096 }
2097 
2098 static void hci_power_transition_to_initializing(void){
2099     // set up state machine
2100     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
2101     hci_stack->hci_packet_buffer_reserved = 0;
2102     hci_stack->state = HCI_STATE_INITIALIZING;
2103     hci_stack->substate = HCI_INIT_SEND_RESET;
2104 }
2105 
2106 int hci_power_control(HCI_POWER_MODE power_mode){
2107 
2108     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
2109 
2110     int err = 0;
2111     switch (hci_stack->state){
2112 
2113         case HCI_STATE_OFF:
2114             switch (power_mode){
2115                 case HCI_POWER_ON:
2116                     err = hci_power_control_on();
2117                     if (err) {
2118                         log_error("hci_power_control_on() error %u", err);
2119                         return err;
2120                     }
2121                     hci_power_transition_to_initializing();
2122                     break;
2123                 case HCI_POWER_OFF:
2124                     // do nothing
2125                     break;
2126                 case HCI_POWER_SLEEP:
2127                     // do nothing (with SLEEP == OFF)
2128                     break;
2129             }
2130             break;
2131 
2132         case HCI_STATE_INITIALIZING:
2133             switch (power_mode){
2134                 case HCI_POWER_ON:
2135                     // do nothing
2136                     break;
2137                 case HCI_POWER_OFF:
2138                     // no connections yet, just turn it off
2139                     hci_power_control_off();
2140                     break;
2141                 case HCI_POWER_SLEEP:
2142                     // no connections yet, just turn it off
2143                     hci_power_control_sleep();
2144                     break;
2145             }
2146             break;
2147 
2148         case HCI_STATE_WORKING:
2149             switch (power_mode){
2150                 case HCI_POWER_ON:
2151                     // do nothing
2152                     break;
2153                 case HCI_POWER_OFF:
2154                     // see hci_run
2155                     hci_stack->state = HCI_STATE_HALTING;
2156                     break;
2157                 case HCI_POWER_SLEEP:
2158                     // see hci_run
2159                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
2160                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
2161                     break;
2162             }
2163             break;
2164 
2165         case HCI_STATE_HALTING:
2166             switch (power_mode){
2167                 case HCI_POWER_ON:
2168                     hci_power_transition_to_initializing();
2169                     break;
2170                 case HCI_POWER_OFF:
2171                     // do nothing
2172                     break;
2173                 case HCI_POWER_SLEEP:
2174                     // see hci_run
2175                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
2176                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
2177                     break;
2178             }
2179             break;
2180 
2181         case HCI_STATE_FALLING_ASLEEP:
2182             switch (power_mode){
2183                 case HCI_POWER_ON:
2184 
2185 #ifdef HAVE_PLATFORM_IPHONE_OS
2186                     // nothing to do, if H4 supports power management
2187                     if (btstack_control_iphone_power_management_enabled()){
2188                         hci_stack->state = HCI_STATE_INITIALIZING;
2189                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
2190                         break;
2191                     }
2192 #endif
2193                     hci_power_transition_to_initializing();
2194                     break;
2195                 case HCI_POWER_OFF:
2196                     // see hci_run
2197                     hci_stack->state = HCI_STATE_HALTING;
2198                     break;
2199                 case HCI_POWER_SLEEP:
2200                     // do nothing
2201                     break;
2202             }
2203             break;
2204 
2205         case HCI_STATE_SLEEPING:
2206             switch (power_mode){
2207                 case HCI_POWER_ON:
2208 
2209 #ifdef HAVE_PLATFORM_IPHONE_OS
2210                     // nothing to do, if H4 supports power management
2211                     if (btstack_control_iphone_power_management_enabled()){
2212                         hci_stack->state = HCI_STATE_INITIALIZING;
2213                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
2214                         hci_update_scan_enable();
2215                         break;
2216                     }
2217 #endif
2218                     err = hci_power_control_wake();
2219                     if (err) return err;
2220                     hci_power_transition_to_initializing();
2221                     break;
2222                 case HCI_POWER_OFF:
2223                     hci_stack->state = HCI_STATE_HALTING;
2224                     break;
2225                 case HCI_POWER_SLEEP:
2226                     // do nothing
2227                     break;
2228             }
2229             break;
2230     }
2231 
2232     // create internal event
2233 	hci_emit_state();
2234 
2235 	// trigger next/first action
2236 	hci_run();
2237 
2238     return 0;
2239 }
2240 
2241 static void hci_update_scan_enable(void){
2242     // 2 = page scan, 1 = inq scan
2243     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
2244     hci_run();
2245 }
2246 
2247 void hci_discoverable_control(uint8_t enable){
2248     if (enable) enable = 1; // normalize argument
2249 
2250     if (hci_stack->discoverable == enable){
2251         hci_emit_discoverable_enabled(hci_stack->discoverable);
2252         return;
2253     }
2254 
2255     hci_stack->discoverable = enable;
2256     hci_update_scan_enable();
2257 }
2258 
2259 void hci_connectable_control(uint8_t enable){
2260     if (enable) enable = 1; // normalize argument
2261 
2262     // don't emit event
2263     if (hci_stack->connectable == enable) return;
2264 
2265     hci_stack->connectable = enable;
2266     hci_update_scan_enable();
2267 }
2268 
2269 void hci_local_bd_addr(bd_addr_t address_buffer){
2270     memcpy(address_buffer, hci_stack->local_bd_addr, 6);
2271 }
2272 
2273 static void hci_run(void){
2274 
2275     // log_info("hci_run: entered");
2276     btstack_linked_item_t * it;
2277 
2278     // send continuation fragments first, as they block the prepared packet buffer
2279     if (hci_stack->acl_fragmentation_total_size > 0) {
2280         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
2281         if (hci_can_send_prepared_acl_packet_now(con_handle)){
2282             hci_connection_t *connection = hci_connection_for_handle(con_handle);
2283             if (connection) {
2284                 hci_send_acl_packet_fragments(connection);
2285                 return;
2286             }
2287             // connection gone -> discard further fragments
2288             hci_stack->acl_fragmentation_total_size = 0;
2289             hci_stack->acl_fragmentation_pos = 0;
2290         }
2291     }
2292 
2293     if (!hci_can_send_command_packet_now()) return;
2294 
2295     // global/non-connection oriented commands
2296 
2297     // decline incoming connections
2298     if (hci_stack->decline_reason){
2299         uint8_t reason = hci_stack->decline_reason;
2300         hci_stack->decline_reason = 0;
2301         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
2302         return;
2303     }
2304 
2305     // send scan enable
2306     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
2307         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
2308         hci_stack->new_scan_enable_value = 0xff;
2309         return;
2310     }
2311 
2312 #ifdef ENABLE_BLE
2313     if (hci_stack->state == HCI_STATE_WORKING){
2314         // handle le scan
2315         switch(hci_stack->le_scanning_state){
2316             case LE_START_SCAN:
2317                 hci_stack->le_scanning_state = LE_SCANNING;
2318                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
2319                 return;
2320 
2321             case LE_STOP_SCAN:
2322                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
2323                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
2324                 return;
2325             default:
2326                 break;
2327         }
2328         if (hci_stack->le_scan_type != 0xff){
2329             // defaults: active scanning, accept all advertisement packets
2330             int scan_type = hci_stack->le_scan_type;
2331             hci_stack->le_scan_type = 0xff;
2332             hci_send_cmd(&hci_le_set_scan_parameters, scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->adv_addr_type, 0);
2333             return;
2334         }
2335         // le advertisement control
2336         if (hci_stack->le_advertisements_todo){
2337             log_info("hci_run: gap_le: adv todo: %x", hci_stack->le_advertisements_todo );
2338         }
2339         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_DISABLE){
2340             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_DISABLE;
2341             hci_send_cmd(&hci_le_set_advertise_enable, 0);
2342             return;
2343         }
2344         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
2345             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
2346             hci_send_cmd(&hci_le_set_advertising_parameters,
2347                  hci_stack->le_advertisements_interval_min,
2348                  hci_stack->le_advertisements_interval_max,
2349                  hci_stack->le_advertisements_type,
2350                  hci_stack->le_advertisements_own_address_type,
2351                  hci_stack->le_advertisements_direct_address_type,
2352                  hci_stack->le_advertisements_direct_address,
2353                  hci_stack->le_advertisements_channel_map,
2354                  hci_stack->le_advertisements_filter_policy);
2355             return;
2356         }
2357         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_DATA){
2358             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_DATA;
2359             hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len,
2360                 hci_stack->le_advertisements_data);
2361             return;
2362         }
2363         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_ENABLE){
2364             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_ENABLE;
2365             hci_send_cmd(&hci_le_set_advertise_enable, 1);
2366             return;
2367         }
2368 
2369         //
2370         // LE Whitelist Management
2371         //
2372 
2373         // check if whitelist needs modification
2374         btstack_linked_list_iterator_t lit;
2375         int modification_pending = 0;
2376         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2377         while (btstack_linked_list_iterator_has_next(&lit)){
2378             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2379             if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
2380                 modification_pending = 1;
2381                 break;
2382             }
2383         }
2384 
2385         if (modification_pending){
2386             // stop connnecting if modification pending
2387             if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
2388                 hci_send_cmd(&hci_le_create_connection_cancel);
2389                 return;
2390             }
2391 
2392             // add/remove entries
2393             btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2394             while (btstack_linked_list_iterator_has_next(&lit)){
2395                 whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2396                 if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
2397                     entry->state = LE_WHITELIST_ON_CONTROLLER;
2398                     hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
2399                     return;
2400 
2401                 }
2402                 if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
2403                     bd_addr_t address;
2404                     bd_addr_type_t address_type = entry->address_type;
2405                     memcpy(address, entry->address, 6);
2406                     btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
2407                     btstack_memory_whitelist_entry_free(entry);
2408                     hci_send_cmd(&hci_le_remove_device_from_white_list, address_type, address);
2409                     return;
2410                 }
2411             }
2412         }
2413 
2414         // start connecting
2415         if ( hci_stack->le_connecting_state == LE_CONNECTING_IDLE &&
2416             !btstack_linked_list_empty(&hci_stack->le_whitelist)){
2417             bd_addr_t null_addr;
2418             memset(null_addr, 0, 6);
2419             hci_send_cmd(&hci_le_create_connection,
2420                  0x0060,    // scan interval: 60 ms
2421                  0x0030,    // scan interval: 30 ms
2422                  1,         // use whitelist
2423                  0,         // peer address type
2424                  null_addr,      // peer bd addr
2425                  hci_stack->adv_addr_type, // our addr type:
2426                  0x0008,    // conn interval min
2427                  0x0018,    // conn interval max
2428                  0,         // conn latency
2429                  0x0048,    // supervision timeout
2430                  0x0001,    // min ce length
2431                  0x0001     // max ce length
2432                  );
2433             return;
2434         }
2435     }
2436 #endif
2437 
2438     // send pending HCI commands
2439     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
2440         hci_connection_t * connection = (hci_connection_t *) it;
2441 
2442         switch(connection->state){
2443             case SEND_CREATE_CONNECTION:
2444                 switch(connection->address_type){
2445                     case BD_ADDR_TYPE_CLASSIC:
2446                         log_info("sending hci_create_connection");
2447                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
2448                         break;
2449                     default:
2450 #ifdef ENABLE_BLE
2451                         log_info("sending hci_le_create_connection");
2452                         hci_send_cmd(&hci_le_create_connection,
2453                                      0x0060,    // scan interval: 60 ms
2454                                      0x0030,    // scan interval: 30 ms
2455                                      0,         // don't use whitelist
2456                                      connection->address_type, // peer address type
2457                                      connection->address,      // peer bd addr
2458                                      hci_stack->adv_addr_type, // our addr type:
2459                                      0x0008,    // conn interval min
2460                                      0x0018,    // conn interval max
2461                                      0,         // conn latency
2462                                      0x0048,    // supervision timeout
2463                                      0x0001,    // min ce length
2464                                      0x0001     // max ce length
2465                                      );
2466 
2467                         connection->state = SENT_CREATE_CONNECTION;
2468 #endif
2469                         break;
2470                 }
2471                 return;
2472 
2473             case RECEIVED_CONNECTION_REQUEST:
2474                 log_info("sending hci_accept_connection_request, remote eSCO %u", connection->remote_supported_feature_eSCO);
2475                 connection->state = ACCEPTED_CONNECTION_REQUEST;
2476                 connection->role  = HCI_ROLE_SLAVE;
2477                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
2478                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
2479                 } else {
2480                     // remote supported feature eSCO is set if link type is eSCO
2481                     uint16_t max_latency;
2482                     uint8_t  retransmission_effort;
2483                     uint16_t packet_types;
2484                     // remote supported feature eSCO is set if link type is eSCO
2485                     if (connection->remote_supported_feature_eSCO){
2486                         // eSCO: S4 - max latency == transmission interval = 0x000c == 12 ms,
2487                         max_latency = 0x000c;
2488                         retransmission_effort = 0x02;
2489                         packet_types = 0x388;
2490                     } else {
2491                         // SCO: max latency, retransmission interval: N/A. any packet type
2492                         max_latency = 0xffff;
2493                         retransmission_effort = 0xff;
2494                         packet_types = 0x003f;
2495                     }
2496                     hci_send_cmd(&hci_accept_synchronous_connection, connection->address, 8000, 8000, max_latency, hci_stack->sco_voice_setting, retransmission_effort, packet_types);
2497                 }
2498                 return;
2499 
2500 #ifdef ENABLE_BLE
2501             case SEND_CANCEL_CONNECTION:
2502                 connection->state = SENT_CANCEL_CONNECTION;
2503                 hci_send_cmd(&hci_le_create_connection_cancel);
2504                 return;
2505 #endif
2506             case SEND_DISCONNECT:
2507                 connection->state = SENT_DISCONNECT;
2508                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
2509                 return;
2510 
2511             default:
2512                 break;
2513         }
2514 
2515         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
2516             log_info("responding to link key request");
2517             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
2518             link_key_t link_key;
2519             link_key_type_t link_key_type;
2520             if ( hci_stack->link_key_db
2521               && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type)
2522               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
2523                connection->link_key_type = link_key_type;
2524                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
2525             } else {
2526                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
2527             }
2528             return;
2529         }
2530 
2531         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
2532             log_info("denying to pin request");
2533             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
2534             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
2535             return;
2536         }
2537 
2538         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
2539             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
2540             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
2541             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
2542                 // tweak authentication requirements
2543                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
2544                 if (connection->bonding_flags & BONDING_DEDICATED){
2545                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2546                 }
2547                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
2548                     authreq |= 1;
2549                 }
2550                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
2551             } else {
2552                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
2553             }
2554             return;
2555         }
2556 
2557         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
2558             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
2559             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
2560             return;
2561         }
2562 
2563         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
2564             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
2565             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
2566             return;
2567         }
2568 
2569         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
2570             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
2571             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
2572             return;
2573         }
2574 
2575         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
2576             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
2577             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
2578             return;
2579         }
2580         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
2581             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
2582             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
2583             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
2584             return;
2585         }
2586         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
2587             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
2588             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
2589             return;
2590         }
2591         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2592             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2593             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2594             return;
2595         }
2596 
2597 #ifdef ENABLE_BLE
2598         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2599             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2600 
2601             uint16_t connection_interval_min = connection->le_conn_interval_min;
2602             connection->le_conn_interval_min = 0;
2603             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2604                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2605                 0x0000, 0xffff);
2606         }
2607 #endif
2608     }
2609 
2610     hci_connection_t * connection;
2611     switch (hci_stack->state){
2612         case HCI_STATE_INITIALIZING:
2613             hci_initializing_run();
2614             break;
2615 
2616         case HCI_STATE_HALTING:
2617 
2618             log_info("HCI_STATE_HALTING");
2619 
2620             // free whitelist entries
2621 #ifdef ENABLE_BLE
2622             {
2623                 btstack_linked_list_iterator_t lit;
2624                 btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2625                 while (btstack_linked_list_iterator_has_next(&lit)){
2626                     whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2627                     btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
2628                     btstack_memory_whitelist_entry_free(entry);
2629                 }
2630             }
2631 #endif
2632             // close all open connections
2633             connection =  (hci_connection_t *) hci_stack->connections;
2634             if (connection){
2635                 uint16_t con_handle = (uint16_t) connection->con_handle;
2636                 if (!hci_can_send_command_packet_now()) return;
2637 
2638                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
2639 
2640                 // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
2641                 hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
2642 
2643                 // ... which would be ignored anyway as we shutdown (free) the connection now
2644                 hci_shutdown_connection(connection);
2645 
2646                 // finally, send the disconnect command
2647                 hci_send_cmd(&hci_disconnect, con_handle, 0x13);  // remote closed connection
2648                 return;
2649             }
2650             log_info("HCI_STATE_HALTING, calling off");
2651 
2652             // switch mode
2653             hci_power_control_off();
2654 
2655             log_info("HCI_STATE_HALTING, emitting state");
2656             hci_emit_state();
2657             log_info("HCI_STATE_HALTING, done");
2658             break;
2659 
2660         case HCI_STATE_FALLING_ASLEEP:
2661             switch(hci_stack->substate) {
2662                 case HCI_FALLING_ASLEEP_DISCONNECT:
2663                     log_info("HCI_STATE_FALLING_ASLEEP");
2664                     // close all open connections
2665                     connection =  (hci_connection_t *) hci_stack->connections;
2666 
2667 #ifdef HAVE_PLATFORM_IPHONE_OS
2668                     // don't close connections, if H4 supports power management
2669                     if (btstack_control_iphone_power_management_enabled()){
2670                         connection = NULL;
2671                     }
2672 #endif
2673                     if (connection){
2674 
2675                         // send disconnect
2676                         if (!hci_can_send_command_packet_now()) return;
2677 
2678                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2679                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2680 
2681                         // send disconnected event right away - causes higher layer connections to get closed, too.
2682                         hci_shutdown_connection(connection);
2683                         return;
2684                     }
2685 
2686                     if (hci_classic_supported()){
2687                         // disable page and inquiry scan
2688                         if (!hci_can_send_command_packet_now()) return;
2689 
2690                         log_info("HCI_STATE_HALTING, disabling inq scans");
2691                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2692 
2693                         // continue in next sub state
2694                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
2695                         break;
2696                     }
2697                     // fall through for ble-only chips
2698 
2699                 case HCI_FALLING_ASLEEP_COMPLETE:
2700                     log_info("HCI_STATE_HALTING, calling sleep");
2701 #ifdef HAVE_PLATFORM_IPHONE_OS
2702                     // don't actually go to sleep, if H4 supports power management
2703                     if (btstack_control_iphone_power_management_enabled()){
2704                         // SLEEP MODE reached
2705                         hci_stack->state = HCI_STATE_SLEEPING;
2706                         hci_emit_state();
2707                         break;
2708                     }
2709 #endif
2710                     // switch mode
2711                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2712                     hci_emit_state();
2713                     break;
2714 
2715                 default:
2716                     break;
2717             }
2718             break;
2719 
2720         default:
2721             break;
2722     }
2723 }
2724 
2725 int hci_send_cmd_packet(uint8_t *packet, int size){
2726     bd_addr_t addr;
2727     hci_connection_t * conn;
2728     // house-keeping
2729 
2730     // create_connection?
2731     if (IS_COMMAND(packet, hci_create_connection)){
2732         reverse_bd_addr(&packet[3], addr);
2733         log_info("Create_connection to %s", bd_addr_to_str(addr));
2734 
2735         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2736         if (!conn){
2737             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2738             if (!conn){
2739                 // notify client that alloc failed
2740                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2741                 return 0; // don't sent packet to controller
2742             }
2743             conn->state = SEND_CREATE_CONNECTION;
2744         }
2745         log_info("conn state %u", conn->state);
2746         switch (conn->state){
2747             // if connection active exists
2748             case OPEN:
2749                 // and OPEN, emit connection complete command, don't send to controller
2750                 hci_emit_connection_complete(conn, 0);
2751                 return 0;
2752             case SEND_CREATE_CONNECTION:
2753                 // connection created by hci, e.g. dedicated bonding
2754                 break;
2755             default:
2756                 // otherwise, just ignore as it is already in the open process
2757                 return 0;
2758         }
2759         conn->state = SENT_CREATE_CONNECTION;
2760     }
2761     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2762         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2763     }
2764     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2765         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2766     }
2767 
2768     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2769         if (hci_stack->link_key_db){
2770             reverse_bd_addr(&packet[3], addr);
2771             hci_stack->link_key_db->delete_link_key(addr);
2772         }
2773     }
2774 
2775     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2776     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2777         reverse_bd_addr(&packet[3], addr);
2778         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2779         if (conn){
2780             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2781         }
2782     }
2783 
2784     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2785     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2786     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2787     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2788         reverse_bd_addr(&packet[3], addr);
2789         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2790         if (conn){
2791             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2792         }
2793     }
2794 
2795     if (IS_COMMAND(packet, hci_write_loopback_mode)){
2796         hci_stack->loopback_mode = packet[3];
2797     }
2798 
2799 #ifdef ENABLE_BLE
2800     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2801         hci_stack->adv_addr_type = packet[8];
2802     }
2803     if (IS_COMMAND(packet, hci_le_set_random_address)){
2804         reverse_bd_addr(&packet[3], hci_stack->adv_address);
2805     }
2806     if (IS_COMMAND(packet, hci_le_set_advertise_enable)){
2807         hci_stack->le_advertisements_active = packet[3];
2808     }
2809     if (IS_COMMAND(packet, hci_le_create_connection)){
2810         // white list used?
2811         uint8_t initiator_filter_policy = packet[7];
2812         switch (initiator_filter_policy){
2813             case 0:
2814                 // whitelist not used
2815                 hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
2816                 break;
2817             case 1:
2818                 hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
2819                 break;
2820             default:
2821                 log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
2822                 break;
2823         }
2824     }
2825     if (IS_COMMAND(packet, hci_le_create_connection_cancel)){
2826         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2827     }
2828 #endif
2829 
2830     hci_stack->num_cmd_packets--;
2831 
2832     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2833     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2834 
2835     // release packet buffer for synchronous transport implementations
2836     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2837         hci_stack->hci_packet_buffer_reserved = 0;
2838     }
2839 
2840     return err;
2841 }
2842 
2843 // disconnect because of security block
2844 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2845     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2846     if (!connection) return;
2847     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2848 }
2849 
2850 
2851 // Configure Secure Simple Pairing
2852 
2853 // enable will enable SSP during init
2854 void hci_ssp_set_enable(int enable){
2855     hci_stack->ssp_enable = enable;
2856 }
2857 
2858 static int hci_local_ssp_activated(void){
2859     return hci_ssp_supported() && hci_stack->ssp_enable;
2860 }
2861 
2862 // if set, BTstack will respond to io capability request using authentication requirement
2863 void hci_ssp_set_io_capability(int io_capability){
2864     hci_stack->ssp_io_capability = io_capability;
2865 }
2866 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2867     hci_stack->ssp_authentication_requirement = authentication_requirement;
2868 }
2869 
2870 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2871 void hci_ssp_set_auto_accept(int auto_accept){
2872     hci_stack->ssp_auto_accept = auto_accept;
2873 }
2874 
2875 /**
2876  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2877  */
2878 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2879 
2880     if (!hci_can_send_command_packet_now()){
2881         log_error("hci_send_cmd called but cannot send packet now");
2882         return 0;
2883     }
2884 
2885     // for HCI INITIALIZATION
2886     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2887     hci_stack->last_cmd_opcode = cmd->opcode;
2888 
2889     hci_reserve_packet_buffer();
2890     uint8_t * packet = hci_stack->hci_packet_buffer;
2891 
2892     va_list argptr;
2893     va_start(argptr, cmd);
2894     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
2895     va_end(argptr);
2896 
2897     return hci_send_cmd_packet(packet, size);
2898 }
2899 
2900 // Create various non-HCI events.
2901 // TODO: generalize, use table similar to hci_create_command
2902 
2903 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
2904     // dump packet
2905     if (dump) {
2906         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
2907     }
2908 
2909     // dispatch to all event handlers
2910     btstack_linked_list_iterator_t it;
2911     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
2912     while (btstack_linked_list_iterator_has_next(&it)){
2913         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
2914         entry->callback(HCI_EVENT_PACKET, 0, event, size);
2915     }
2916 }
2917 
2918 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
2919     if (!hci_stack->acl_packet_handler) return;
2920     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, packet, size);
2921 }
2922 
2923 static void hci_notify_if_sco_can_send_now(void){
2924     // notify SCO sender if waiting
2925     if (!hci_stack->sco_waiting_for_can_send_now) return;
2926     if (hci_can_send_sco_packet_now()){
2927         hci_stack->sco_waiting_for_can_send_now = 0;
2928         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
2929         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
2930         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2931     }
2932 }
2933 
2934 void hci_emit_state(void){
2935     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2936     uint8_t event[3];
2937     event[0] = BTSTACK_EVENT_STATE;
2938     event[1] = sizeof(event) - 2;
2939     event[2] = hci_stack->state;
2940     hci_emit_event(event, sizeof(event), 1);
2941 }
2942 
2943 static void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2944     uint8_t event[13];
2945     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2946     event[1] = sizeof(event) - 2;
2947     event[2] = status;
2948     little_endian_store_16(event, 3, conn->con_handle);
2949     reverse_bd_addr(conn->address, &event[5]);
2950     event[11] = 1; // ACL connection
2951     event[12] = 0; // encryption disabled
2952     hci_emit_event(event, sizeof(event), 1);
2953 }
2954 
2955 static void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, uint16_t conn_handle, uint8_t status){
2956     uint8_t event[21];
2957     event[0] = HCI_EVENT_LE_META;
2958     event[1] = sizeof(event) - 2;
2959     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2960     event[3] = status;
2961     little_endian_store_16(event, 4, conn_handle);
2962     event[6] = 0; // TODO: role
2963     event[7] = address_type;
2964     reverse_bd_addr(address, &event[8]);
2965     little_endian_store_16(event, 14, 0); // interval
2966     little_endian_store_16(event, 16, 0); // latency
2967     little_endian_store_16(event, 18, 0); // supervision timeout
2968     event[20] = 0; // master clock accuracy
2969     hci_emit_event(event, sizeof(event), 1);
2970 }
2971 
2972 static void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2973     uint8_t event[6];
2974     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2975     event[1] = sizeof(event) - 2;
2976     event[2] = 0; // status = OK
2977     little_endian_store_16(event, 3, handle);
2978     event[5] = reason;
2979     hci_emit_event(event, sizeof(event), 1);
2980 }
2981 
2982 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2983     if (disable_l2cap_timeouts) return;
2984     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2985     uint8_t event[4];
2986     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2987     event[1] = sizeof(event) - 2;
2988     little_endian_store_16(event, 2, conn->con_handle);
2989     hci_emit_event(event, sizeof(event), 1);
2990 }
2991 
2992 static void hci_emit_nr_connections_changed(void){
2993     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2994     uint8_t event[3];
2995     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2996     event[1] = sizeof(event) - 2;
2997     event[2] = nr_hci_connections();
2998     hci_emit_event(event, sizeof(event), 1);
2999 }
3000 
3001 static void hci_emit_hci_open_failed(void){
3002     log_info("BTSTACK_EVENT_POWERON_FAILED");
3003     uint8_t event[2];
3004     event[0] = BTSTACK_EVENT_POWERON_FAILED;
3005     event[1] = sizeof(event) - 2;
3006     hci_emit_event(event, sizeof(event), 1);
3007 }
3008 
3009 static void hci_emit_discoverable_enabled(uint8_t enabled){
3010     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
3011     uint8_t event[3];
3012     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
3013     event[1] = sizeof(event) - 2;
3014     event[2] = enabled;
3015     hci_emit_event(event, sizeof(event), 1);
3016 }
3017 
3018 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
3019     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
3020     uint8_t event[5];
3021     int pos = 0;
3022     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
3023     event[pos++] = sizeof(event) - 2;
3024     little_endian_store_16(event, 2, con_handle);
3025     pos += 2;
3026     event[pos++] = level;
3027     hci_emit_event(event, sizeof(event), 1);
3028 }
3029 
3030 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
3031     log_info("hci_emit_dedicated_bonding_result %u ", status);
3032     uint8_t event[9];
3033     int pos = 0;
3034     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
3035     event[pos++] = sizeof(event) - 2;
3036     event[pos++] = status;
3037     reverse_bd_addr(address, &event[pos]);
3038     pos += 6;
3039     hci_emit_event(event, sizeof(event), 1);
3040 }
3041 
3042 // query if remote side supports eSCO
3043 int hci_remote_esco_supported(hci_con_handle_t con_handle){
3044     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3045     if (!connection) return 0;
3046     return connection->remote_supported_feature_eSCO;
3047 }
3048 
3049 // query if remote side supports SSP
3050 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
3051     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3052     if (!connection) return 0;
3053     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
3054 }
3055 
3056 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
3057     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
3058 }
3059 
3060 // GAP API
3061 /**
3062  * @bbrief enable/disable bonding. default is enabled
3063  * @praram enabled
3064  */
3065 void gap_set_bondable_mode(int enable){
3066     hci_stack->bondable = enable ? 1 : 0;
3067 }
3068 /**
3069  * @brief Get bondable mode.
3070  * @return 1 if bondable
3071  */
3072 int gap_get_bondable_mode(void){
3073     return hci_stack->bondable;
3074 }
3075 
3076 /**
3077  * @brief map link keys to security levels
3078  */
3079 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
3080     switch (link_key_type){
3081         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
3082             return LEVEL_4;
3083         case COMBINATION_KEY:
3084         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
3085             return LEVEL_3;
3086         default:
3087             return LEVEL_2;
3088     }
3089 }
3090 
3091 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
3092     if (!connection) return LEVEL_0;
3093     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
3094     return gap_security_level_for_link_key_type(connection->link_key_type);
3095 }
3096 
3097 
3098 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
3099     log_info("gap_mitm_protection_required_for_security_level %u", level);
3100     return level > LEVEL_2;
3101 }
3102 
3103 /**
3104  * @brief get current security level
3105  */
3106 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
3107     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3108     if (!connection) return LEVEL_0;
3109     return gap_security_level_for_connection(connection);
3110 }
3111 
3112 /**
3113  * @brief request connection to device to
3114  * @result GAP_AUTHENTICATION_RESULT
3115  */
3116 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
3117     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3118     if (!connection){
3119         hci_emit_security_level(con_handle, LEVEL_0);
3120         return;
3121     }
3122     gap_security_level_t current_level = gap_security_level(con_handle);
3123     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
3124     if (current_level >= requested_level){
3125         hci_emit_security_level(con_handle, current_level);
3126         return;
3127     }
3128 
3129     connection->requested_security_level = requested_level;
3130 
3131 #if 0
3132     // sending encryption request without a link key results in an error.
3133     // TODO: figure out how to use it properly
3134 
3135     // would enabling ecnryption suffice (>= LEVEL_2)?
3136     if (hci_stack->link_key_db){
3137         link_key_type_t link_key_type;
3138         link_key_t      link_key;
3139         if (hci_stack->link_key_db->get_link_key( &connection->address, &link_key, &link_key_type)){
3140             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
3141                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3142                 return;
3143             }
3144         }
3145     }
3146 #endif
3147 
3148     // try to authenticate connection
3149     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
3150     hci_run();
3151 }
3152 
3153 /**
3154  * @brief start dedicated bonding with device. disconnect after bonding
3155  * @param device
3156  * @param request MITM protection
3157  * @result GAP_DEDICATED_BONDING_COMPLETE
3158  */
3159 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
3160 
3161     // create connection state machine
3162     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
3163 
3164     if (!connection){
3165         return BTSTACK_MEMORY_ALLOC_FAILED;
3166     }
3167 
3168     // delete linkn key
3169     hci_drop_link_key_for_bd_addr(device);
3170 
3171     // configure LEVEL_2/3, dedicated bonding
3172     connection->state = SEND_CREATE_CONNECTION;
3173     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
3174     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
3175     connection->bonding_flags = BONDING_DEDICATED;
3176 
3177     // wait for GAP Security Result and send GAP Dedicated Bonding complete
3178 
3179     // handle: connnection failure (connection complete != ok)
3180     // handle: authentication failure
3181     // handle: disconnect on done
3182 
3183     hci_run();
3184 
3185     return 0;
3186 }
3187 
3188 void gap_set_local_name(const char * local_name){
3189     hci_stack->local_name = local_name;
3190 }
3191 
3192 void gap_start_scan(void){
3193     if (hci_stack->le_scanning_state == LE_SCANNING) return;
3194     hci_stack->le_scanning_state = LE_START_SCAN;
3195     hci_run();
3196 }
3197 
3198 void gap_stop_scan(void){
3199     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return;
3200     hci_stack->le_scanning_state = LE_STOP_SCAN;
3201     hci_run();
3202 }
3203 
3204 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
3205     hci_stack->le_scan_type     = scan_type;
3206     hci_stack->le_scan_interval = scan_interval;
3207     hci_stack->le_scan_window   = scan_window;
3208     hci_run();
3209 }
3210 
3211 uint8_t gap_connect(bd_addr_t addr, bd_addr_type_t addr_type){
3212     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3213     if (!conn){
3214         log_info("gap_connect: no connection exists yet, creating context");
3215         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
3216         if (!conn){
3217             // notify client that alloc failed
3218             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
3219             log_info("gap_connect: failed to alloc hci_connection_t");
3220             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
3221         }
3222         conn->state = SEND_CREATE_CONNECTION;
3223         log_info("gap_connect: send create connection next");
3224         hci_run();
3225         return 0;
3226     }
3227 
3228     if (!hci_is_le_connection(conn) ||
3229         conn->state == SEND_CREATE_CONNECTION ||
3230         conn->state == SENT_CREATE_CONNECTION) {
3231         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
3232         log_error("gap_connect: classic connection or connect is already being created");
3233         return GATT_CLIENT_IN_WRONG_STATE;
3234     }
3235 
3236     log_info("gap_connect: context exists with state %u", conn->state);
3237     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
3238     hci_run();
3239     return 0;
3240 }
3241 
3242 // @assumption: only a single outgoing LE Connection exists
3243 static hci_connection_t * gap_get_outgoing_connection(void){
3244     btstack_linked_item_t *it;
3245     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3246         hci_connection_t * conn = (hci_connection_t *) it;
3247         if (!hci_is_le_connection(conn)) continue;
3248         switch (conn->state){
3249             case SEND_CREATE_CONNECTION:
3250             case SENT_CREATE_CONNECTION:
3251                 return conn;
3252             default:
3253                 break;
3254         };
3255     }
3256     return NULL;
3257 }
3258 
3259 uint8_t gap_connect_cancel(void){
3260     hci_connection_t * conn = gap_get_outgoing_connection();
3261     if (!conn) return 0;
3262     switch (conn->state){
3263         case SEND_CREATE_CONNECTION:
3264             // skip sending create connection and emit event instead
3265             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
3266             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
3267             btstack_memory_hci_connection_free( conn );
3268             break;
3269         case SENT_CREATE_CONNECTION:
3270             // request to send cancel connection
3271             conn->state = SEND_CANCEL_CONNECTION;
3272             hci_run();
3273             break;
3274         default:
3275             break;
3276     }
3277     return 0;
3278 }
3279 
3280 /**
3281  * @brief Updates the connection parameters for a given LE connection
3282  * @param handle
3283  * @param conn_interval_min (unit: 1.25ms)
3284  * @param conn_interval_max (unit: 1.25ms)
3285  * @param conn_latency
3286  * @param supervision_timeout (unit: 10ms)
3287  * @returns 0 if ok
3288  */
3289 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
3290     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
3291     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3292     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3293     connection->le_conn_interval_min = conn_interval_min;
3294     connection->le_conn_interval_max = conn_interval_max;
3295     connection->le_conn_latency = conn_latency;
3296     connection->le_supervision_timeout = supervision_timeout;
3297     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
3298     hci_run();
3299     return 0;
3300 }
3301 
3302 /**
3303  * @brief Request an update of the connection parameter for a given LE connection
3304  * @param handle
3305  * @param conn_interval_min (unit: 1.25ms)
3306  * @param conn_interval_max (unit: 1.25ms)
3307  * @param conn_latency
3308  * @param supervision_timeout (unit: 10ms)
3309  * @returns 0 if ok
3310  */
3311 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
3312     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
3313     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3314     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3315     connection->le_conn_interval_min = conn_interval_min;
3316     connection->le_conn_interval_max = conn_interval_max;
3317     connection->le_conn_latency = conn_latency;
3318     connection->le_supervision_timeout = supervision_timeout;
3319     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
3320     hci_run();
3321     return 0;
3322 }
3323 
3324 /**
3325  * @brief Set Advertisement Data
3326  * @param advertising_data_length
3327  * @param advertising_data (max 31 octets)
3328  * @note data is not copied, pointer has to stay valid
3329  */
3330 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
3331     hci_stack->le_advertisements_data_len = advertising_data_length;
3332     hci_stack->le_advertisements_data = advertising_data;
3333     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_DATA;
3334     // disable advertisements before setting data
3335     if (hci_stack->le_advertisements_active){
3336         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE | LE_ADVERTISEMENT_TASKS_ENABLE;
3337     }
3338     hci_run();
3339 }
3340 
3341 /**
3342  * @brief Set Advertisement Parameters
3343  * @param adv_int_min
3344  * @param adv_int_max
3345  * @param adv_type
3346  * @param own_address_type
3347  * @param direct_address_type
3348  * @param direct_address
3349  * @param channel_map
3350  * @param filter_policy
3351  *
3352  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
3353  */
3354  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
3355     uint8_t own_address_type, uint8_t direct_address_typ, bd_addr_t direct_address,
3356     uint8_t channel_map, uint8_t filter_policy) {
3357 
3358     hci_stack->le_advertisements_interval_min = adv_int_min;
3359     hci_stack->le_advertisements_interval_max = adv_int_max;
3360     hci_stack->le_advertisements_type = adv_type;
3361     hci_stack->le_advertisements_own_address_type = own_address_type;
3362     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
3363     hci_stack->le_advertisements_channel_map = channel_map;
3364     hci_stack->le_advertisements_filter_policy = filter_policy;
3365     memcpy(hci_stack->le_advertisements_direct_address, direct_address, 6);
3366 
3367     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3368     // disable advertisements before changing params
3369     if (hci_stack->le_advertisements_active){
3370         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE | LE_ADVERTISEMENT_TASKS_ENABLE;
3371     }
3372     hci_run();
3373  }
3374 
3375 /**
3376  * @brief Enable/Disable Advertisements
3377  * @param enabled
3378  */
3379 void gap_advertisements_enable(int enabled){
3380     hci_stack->le_advertisements_enabled = enabled;
3381     if (enabled && !hci_stack->le_advertisements_active){
3382         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
3383     }
3384     if (!enabled && hci_stack->le_advertisements_active){
3385         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE;
3386     }
3387     hci_run();
3388 }
3389 
3390 
3391 uint8_t gap_disconnect(hci_con_handle_t handle){
3392     hci_connection_t * conn = hci_connection_for_handle(handle);
3393     if (!conn){
3394         hci_emit_disconnection_complete(handle, 0);
3395         return 0;
3396     }
3397     conn->state = SEND_DISCONNECT;
3398     hci_run();
3399     return 0;
3400 }
3401 
3402 /**
3403  * @brief Get connection type
3404  * @param con_handle
3405  * @result connection_type
3406  */
3407 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
3408     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
3409     if (!conn) return GAP_CONNECTION_INVALID;
3410     switch (conn->address_type){
3411         case BD_ADDR_TYPE_LE_PUBLIC:
3412         case BD_ADDR_TYPE_LE_RANDOM:
3413             return GAP_CONNECTION_LE;
3414         case BD_ADDR_TYPE_SCO:
3415             return GAP_CONNECTION_SCO;
3416         case BD_ADDR_TYPE_CLASSIC:
3417             return GAP_CONNECTION_ACL;
3418         default:
3419             return GAP_CONNECTION_INVALID;
3420     }
3421 }
3422 
3423 #ifdef ENABLE_BLE
3424 
3425 /**
3426  * @brief Auto Connection Establishment - Start Connecting to device
3427  * @param address_typ
3428  * @param address
3429  * @returns 0 if ok
3430  */
3431 int gap_auto_connection_start(bd_addr_type_t address_type, bd_addr_t address){
3432     // check capacity
3433     int num_entries = btstack_linked_list_count(&hci_stack->le_whitelist);
3434     if (num_entries >= hci_stack->le_whitelist_capacity) return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
3435     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
3436     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
3437     entry->address_type = address_type;
3438     memcpy(entry->address, address, 6);
3439     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
3440     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
3441     hci_run();
3442     return 0;
3443 }
3444 
3445 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address){
3446     btstack_linked_list_iterator_t it;
3447     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
3448     while (btstack_linked_list_iterator_has_next(&it)){
3449         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
3450         if (entry->address_type != address_type) continue;
3451         if (memcmp(entry->address, address, 6) != 0) continue;
3452         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
3453             // remove from controller if already present
3454             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3455             continue;
3456         }
3457         // direclty remove entry from whitelist
3458         btstack_linked_list_iterator_remove(&it);
3459         btstack_memory_whitelist_entry_free(entry);
3460     }
3461 }
3462 
3463 /**
3464  * @brief Auto Connection Establishment - Stop Connecting to device
3465  * @param address_typ
3466  * @param address
3467  * @returns 0 if ok
3468  */
3469 int gap_auto_connection_stop(bd_addr_type_t address_type, bd_addr_t address){
3470     hci_remove_from_whitelist(address_type, address);
3471     hci_run();
3472     return 0;
3473 }
3474 
3475 /**
3476  * @brief Auto Connection Establishment - Stop everything
3477  * @note  Convenience function to stop all active auto connection attempts
3478  */
3479 void gap_auto_connection_stop_all(void){
3480     btstack_linked_list_iterator_t it;
3481     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
3482     while (btstack_linked_list_iterator_has_next(&it)){
3483         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
3484         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
3485             // remove from controller if already present
3486             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3487             continue;
3488         }
3489         // directly remove entry from whitelist
3490         btstack_linked_list_iterator_remove(&it);
3491         btstack_memory_whitelist_entry_free(entry);
3492     }
3493     hci_run();
3494 }
3495 
3496 #endif
3497 
3498 /**
3499  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
3500  */
3501 void hci_set_sco_voice_setting(uint16_t voice_setting){
3502     hci_stack->sco_voice_setting = voice_setting;
3503 }
3504 
3505 /**
3506  * @brief Get SCO Voice Setting
3507  * @return current voice setting
3508  */
3509 uint16_t hci_get_sco_voice_setting(){
3510     return hci_stack->sco_voice_setting;
3511 }
3512 
3513 /** @brief Get SCO packet length for current SCO Voice setting
3514  *  @note  Using SCO packets of the exact length is required for USB transfer
3515  *  @return Length of SCO packets in bytes (not audio frames)
3516  */
3517 int hci_get_sco_packet_length(void){
3518     // see Core Spec for H2 USB Transfer.
3519     if (hci_stack->sco_voice_setting & 0x0020) return 51;
3520     return 27;
3521 }
3522 
3523 /**
3524  * @brief Set callback for Bluetooth Hardware Error
3525  */
3526 void hci_set_hardware_error_callback(void (*fn)(void)){
3527     hci_stack->hardware_error_callback = fn;
3528 }
3529 
3530 void hci_disconnect_all(void){
3531     btstack_linked_list_iterator_t it;
3532     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
3533     while (btstack_linked_list_iterator_has_next(&it)){
3534         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
3535         if (con->state == SENT_DISCONNECT) continue;
3536         con->state = SEND_DISCONNECT;
3537     }
3538     hci_run();
3539 }
3540