xref: /btstack/src/hci.c (revision dde9ff1e1989698c4502e3c8fea2b7ddfa85caf8)
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 #define BTSTACK_FILE__ "hci.c"
39 
40 /*
41  *  hci.c
42  *
43  *  Created by Matthias Ringwald on 4/29/09.
44  *
45  */
46 
47 #include "btstack_config.h"
48 
49 
50 #ifdef ENABLE_CLASSIC
51 #ifdef HAVE_EMBEDDED_TICK
52 #include "btstack_run_loop_embedded.h"
53 #endif
54 #endif
55 
56 #ifdef HAVE_PLATFORM_IPHONE_OS
57 #include "../port/ios/src/btstack_control_iphone.h"
58 #endif
59 
60 #ifdef ENABLE_BLE
61 #include "gap.h"
62 #include "ble/le_device_db.h"
63 #endif
64 
65 #include <stdarg.h>
66 #include <string.h>
67 #include <inttypes.h>
68 
69 #include "btstack_debug.h"
70 #include "btstack_event.h"
71 #include "btstack_linked_list.h"
72 #include "btstack_memory.h"
73 #include "bluetooth_company_id.h"
74 #include "bluetooth_data_types.h"
75 #include "gap.h"
76 #include "hci.h"
77 #include "hci_cmd.h"
78 #include "hci_dump.h"
79 #include "ad_parser.h"
80 
81 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
82 #ifndef HCI_HOST_ACL_PACKET_NUM
83 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
84 #endif
85 #ifndef HCI_HOST_ACL_PACKET_LEN
86 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
87 #endif
88 #ifndef HCI_HOST_SCO_PACKET_NUM
89 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
90 #endif
91 #ifndef HCI_HOST_SCO_PACKET_LEN
92 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
93 #endif
94 #endif
95 
96 #define HCI_CONNECTION_TIMEOUT_MS 10000
97 
98 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
99 #define HCI_RESET_RESEND_TIMEOUT_MS 200
100 #endif
101 
102 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
103 #ifndef GAP_INQUIRY_MAX_NAME_LEN
104 #define GAP_INQUIRY_MAX_NAME_LEN 32
105 #endif
106 
107 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
108 #define GAP_INQUIRY_DURATION_MIN 0x01
109 #define GAP_INQUIRY_DURATION_MAX 0x30
110 #define GAP_INQUIRY_STATE_ACTIVE 0x80
111 #define GAP_INQUIRY_STATE_IDLE 0
112 #define GAP_INQUIRY_STATE_W2_CANCEL 0x81
113 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x82
114 
115 // GAP Remote Name Request
116 #define GAP_REMOTE_NAME_STATE_IDLE 0
117 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
118 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
119 
120 // GAP Pairing
121 #define GAP_PAIRING_STATE_IDLE                       0
122 #define GAP_PAIRING_STATE_SEND_PIN                   1
123 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
124 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
125 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
126 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
127 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
128 
129 
130 // prototypes
131 #ifdef ENABLE_CLASSIC
132 static void hci_update_scan_enable(void);
133 static void hci_emit_discoverable_enabled(uint8_t enabled);
134 static int  hci_local_ssp_activated(void);
135 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
136 static bool hci_ssp_supported(hci_connection_t * connection);
137 static void hci_notify_if_sco_can_send_now(void);
138 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
139 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
140 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
141 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
142 static void hci_connection_timestamp(hci_connection_t *connection);
143 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
144 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
145 #endif
146 
147 static int  hci_power_control_on(void);
148 static void hci_power_control_off(void);
149 static void hci_state_reset(void);
150 static void hci_emit_transport_packet_sent(void);
151 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
152 static void hci_emit_nr_connections_changed(void);
153 static void hci_emit_hci_open_failed(void);
154 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
155 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
156 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
157 static void hci_run(void);
158 static int  hci_is_le_connection(hci_connection_t * connection);
159 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
160 
161 #ifdef ENABLE_CLASSIC
162 static int hci_have_usb_transport(void);
163 #endif
164 
165 #ifdef ENABLE_BLE
166 #ifdef ENABLE_LE_CENTRAL
167 // called from test/ble_client/advertising_data_parser.c
168 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
169 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address);
170 static hci_connection_t * gap_get_outgoing_connection(void);
171 #endif
172 #endif
173 
174 // the STACK is here
175 #ifndef HAVE_MALLOC
176 static hci_stack_t   hci_stack_static;
177 #endif
178 static hci_stack_t * hci_stack = NULL;
179 
180 #ifdef ENABLE_CLASSIC
181 // default name
182 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
183 
184 // test helper
185 static uint8_t disable_l2cap_timeouts = 0;
186 #endif
187 
188 /**
189  * create connection for given address
190  *
191  * @return connection OR NULL, if no memory left
192  */
193 static hci_connection_t * create_connection_for_bd_addr_and_type(const bd_addr_t addr, bd_addr_type_t addr_type){
194     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
195     hci_connection_t * conn = btstack_memory_hci_connection_get();
196     if (!conn) return NULL;
197     bd_addr_copy(conn->address, addr);
198     conn->role = HCI_ROLE_INVALID;
199     conn->address_type = addr_type;
200     conn->con_handle = 0xffff;
201     conn->authentication_flags = AUTH_FLAGS_NONE;
202     conn->bonding_flags = 0;
203     conn->requested_security_level = LEVEL_0;
204 #ifdef ENABLE_CLASSIC
205     conn->request_role = HCI_ROLE_INVALID;
206     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
207     btstack_run_loop_set_timer_context(&conn->timeout, conn);
208     hci_connection_timestamp(conn);
209 #endif
210     conn->acl_recombination_length = 0;
211     conn->acl_recombination_pos = 0;
212     conn->num_packets_sent = 0;
213 
214     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
215 #ifdef ENABLE_BLE
216     conn->le_phy_update_all_phys = 0xff;
217 #endif
218 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
219     conn->le_max_tx_octets = 27;
220 #endif
221     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
222     return conn;
223 }
224 
225 
226 /**
227  * get le connection parameter range
228 *
229  * @return le connection parameter range struct
230  */
231 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
232     *range = hci_stack->le_connection_parameter_range;
233 }
234 
235 /**
236  * set le connection parameter range
237  *
238  */
239 
240 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
241     hci_stack->le_connection_parameter_range = *range;
242 }
243 
244 /**
245  * @brief Test if connection parameters are inside in existing rage
246  * @param conn_interval_min (unit: 1.25ms)
247  * @param conn_interval_max (unit: 1.25ms)
248  * @param conn_latency
249  * @param supervision_timeout (unit: 10ms)
250  * @returns 1 if included
251  */
252 int gap_connection_parameter_range_included(le_connection_parameter_range_t * existing_range, uint16_t le_conn_interval_min, uint16_t le_conn_interval_max, uint16_t le_conn_latency, uint16_t le_supervision_timeout){
253     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
254     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
255 
256     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
257     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
258 
259     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
260     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
261 
262     return 1;
263 }
264 
265 /**
266  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
267  * @note: default: 1
268  * @param max_peripheral_connections
269  */
270 #ifdef ENABLE_LE_PERIPHERAL
271 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
272     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
273 }
274 #endif
275 
276 /**
277  * get hci connections iterator
278  *
279  * @return hci connections iterator
280  */
281 
282 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
283     btstack_linked_list_iterator_init(it, &hci_stack->connections);
284 }
285 
286 /**
287  * get connection for a given handle
288  *
289  * @return connection OR NULL, if not found
290  */
291 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
292     btstack_linked_list_iterator_t it;
293     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
294     while (btstack_linked_list_iterator_has_next(&it)){
295         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
296         if ( item->con_handle == con_handle ) {
297             return item;
298         }
299     }
300     return NULL;
301 }
302 
303 /**
304  * get connection for given address
305  *
306  * @return connection OR NULL, if not found
307  */
308 hci_connection_t * hci_connection_for_bd_addr_and_type(const bd_addr_t  addr, bd_addr_type_t addr_type){
309     btstack_linked_list_iterator_t it;
310     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
311     while (btstack_linked_list_iterator_has_next(&it)){
312         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
313         if (connection->address_type != addr_type)  continue;
314         if (memcmp(addr, connection->address, 6) != 0) continue;
315         return connection;
316     }
317     return NULL;
318 }
319 
320 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
321     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
322 }
323 
324 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
325     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
326 }
327 
328 #ifdef ENABLE_CLASSIC
329 
330 #ifdef ENABLE_SCO_OVER_HCI
331 static int hci_number_sco_connections(void){
332     int connections = 0;
333     btstack_linked_list_iterator_t it;
334     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
335     while (btstack_linked_list_iterator_has_next(&it)){
336         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
337         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
338         connections++;
339     }
340     return connections;
341 }
342 #endif
343 
344 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
345     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
346 #ifdef HAVE_EMBEDDED_TICK
347     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
348         // connections might be timed out
349         hci_emit_l2cap_check_timeout(connection);
350     }
351 #else
352     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
353         // connections might be timed out
354         hci_emit_l2cap_check_timeout(connection);
355     }
356 #endif
357 }
358 
359 static void hci_connection_timestamp(hci_connection_t *connection){
360 #ifdef HAVE_EMBEDDED_TICK
361     connection->timestamp = btstack_run_loop_embedded_get_ticks();
362 #else
363     connection->timestamp = btstack_run_loop_get_time_ms();
364 #endif
365 }
366 
367 /**
368  * add authentication flags and reset timer
369  * @note: assumes classic connection
370  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
371  */
372 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
373     bd_addr_t addr;
374     reverse_bd_addr(bd_addr, addr);
375     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
376     if (conn) {
377         connectionSetAuthenticationFlags(conn, flags);
378         hci_connection_timestamp(conn);
379     }
380 }
381 
382 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
383     hci_connection_t * conn = hci_connection_for_handle(handle);
384     if (!conn) return 0;
385     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
386     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
387     return 0;
388 }
389 
390 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
391     if (!hci_stack->link_key_db) return;
392     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
393     hci_stack->link_key_db->delete_link_key(addr);
394 }
395 
396 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
397     if (!hci_stack->link_key_db) return;
398     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
399     hci_stack->link_key_db->put_link_key(addr, link_key, type);
400 }
401 
402 bool gap_get_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t * type){
403 	if (!hci_stack->link_key_db) return false;
404 	int result = hci_stack->link_key_db->get_link_key(addr, link_key, type) != 0;
405 	log_info("link key for %s available %u, type %u", bd_addr_to_str(addr), result, (int) *type);
406 	return result;
407 }
408 
409 void gap_delete_all_link_keys(void){
410     bd_addr_t  addr;
411     link_key_t link_key;
412     link_key_type_t type;
413     btstack_link_key_iterator_t it;
414     int ok = gap_link_key_iterator_init(&it);
415     if (!ok) {
416         log_error("could not initialize iterator");
417         return;
418     }
419     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
420         gap_drop_link_key_for_bd_addr(addr);
421     }
422     gap_link_key_iterator_done(&it);
423 }
424 
425 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
426     if (!hci_stack->link_key_db) return 0;
427     if (!hci_stack->link_key_db->iterator_init) return 0;
428     return hci_stack->link_key_db->iterator_init(it);
429 }
430 int gap_link_key_iterator_get_next(btstack_link_key_iterator_t * it, bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * type){
431     if (!hci_stack->link_key_db) return 0;
432     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
433 }
434 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
435     if (!hci_stack->link_key_db) return;
436     hci_stack->link_key_db->iterator_done(it);
437 }
438 #endif
439 
440 static bool hci_is_le_connection_type(bd_addr_type_t address_type){
441     switch (address_type){
442         case BD_ADDR_TYPE_LE_PUBLIC:
443         case BD_ADDR_TYPE_LE_RANDOM:
444         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
445         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
446             return true;
447         default:
448             return false;
449     }
450 }
451 
452 static int hci_is_le_connection(hci_connection_t * connection){
453     return hci_is_le_connection_type(connection->address_type);
454 }
455 
456 /**
457  * count connections
458  */
459 static int nr_hci_connections(void){
460     int count = 0;
461     btstack_linked_item_t *it;
462     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
463         count++;
464     }
465     return count;
466 }
467 
468 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
469 
470     unsigned int num_packets_sent_classic = 0;
471     unsigned int num_packets_sent_le = 0;
472 
473     btstack_linked_item_t *it;
474     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
475         hci_connection_t * connection = (hci_connection_t *) it;
476         if (hci_is_le_connection(connection)){
477             num_packets_sent_le += connection->num_packets_sent;
478         }
479         if (connection->address_type == BD_ADDR_TYPE_ACL){
480             num_packets_sent_classic += connection->num_packets_sent;
481         }
482     }
483     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
484     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
485     int free_slots_le = 0;
486 
487     if (free_slots_classic < 0){
488         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);
489         return 0;
490     }
491 
492     if (hci_stack->le_acl_packets_total_num){
493         // if we have LE slots, they are used
494         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
495         if (free_slots_le < 0){
496             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);
497             return 0;
498         }
499     } else {
500         // otherwise, classic slots are used for LE, too
501         free_slots_classic -= num_packets_sent_le;
502         if (free_slots_classic < 0){
503             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);
504             return 0;
505         }
506     }
507 
508     switch (address_type){
509         case BD_ADDR_TYPE_UNKNOWN:
510             log_error("hci_number_free_acl_slots: unknown address type");
511             return 0;
512 
513         case BD_ADDR_TYPE_ACL:
514             return free_slots_classic;
515 
516         default:
517            if (hci_stack->le_acl_packets_total_num){
518                return free_slots_le;
519            }
520            return free_slots_classic;
521     }
522 }
523 
524 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
525     // get connection type
526     hci_connection_t * connection = hci_connection_for_handle(con_handle);
527     if (!connection){
528         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
529         return 0;
530     }
531     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
532 }
533 
534 #ifdef ENABLE_CLASSIC
535 static int hci_number_free_sco_slots(void){
536     unsigned int num_sco_packets_sent  = 0;
537     btstack_linked_item_t *it;
538     if (hci_stack->synchronous_flow_control_enabled){
539         // explicit flow control
540         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
541             hci_connection_t * connection = (hci_connection_t *) it;
542             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
543             num_sco_packets_sent += connection->num_packets_sent;
544         }
545         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
546             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
547             return 0;
548         }
549         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
550     } else {
551         // implicit flow control -- TODO
552         int num_ready = 0;
553         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
554             hci_connection_t * connection = (hci_connection_t *) it;
555             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
556             if (connection->sco_tx_ready == 0) continue;
557             num_ready++;
558         }
559         return num_ready;
560     }
561 }
562 #endif
563 
564 // only used to send HCI Host Number Completed Packets
565 static int hci_can_send_comand_packet_transport(void){
566     if (hci_stack->hci_packet_buffer_reserved) return 0;
567 
568     // check for async hci transport implementations
569     if (hci_stack->hci_transport->can_send_packet_now){
570         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
571             return 0;
572         }
573     }
574     return 1;
575 }
576 
577 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
578 int hci_can_send_command_packet_now(void){
579     if (hci_can_send_comand_packet_transport() == 0) return 0;
580     return hci_stack->num_cmd_packets > 0u;
581 }
582 
583 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
584     // check for async hci transport implementations
585     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
586     return hci_stack->hci_transport->can_send_packet_now(packet_type);
587 }
588 
589 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
590     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
591     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
592 }
593 
594 int hci_can_send_acl_le_packet_now(void){
595     if (hci_stack->hci_packet_buffer_reserved) return 0;
596     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
597 }
598 
599 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
600     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
601     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
602 }
603 
604 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
605     if (hci_stack->hci_packet_buffer_reserved) return 0;
606     return hci_can_send_prepared_acl_packet_now(con_handle);
607 }
608 
609 #ifdef ENABLE_CLASSIC
610 int hci_can_send_acl_classic_packet_now(void){
611     if (hci_stack->hci_packet_buffer_reserved) return 0;
612     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
613 }
614 
615 int hci_can_send_prepared_sco_packet_now(void){
616     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return 0;
617     if (hci_have_usb_transport()){
618         return hci_stack->sco_can_send_now;
619     } else {
620         return hci_number_free_sco_slots() > 0;
621     }
622 }
623 
624 int hci_can_send_sco_packet_now(void){
625     if (hci_stack->hci_packet_buffer_reserved) return 0;
626     return hci_can_send_prepared_sco_packet_now();
627 }
628 
629 void hci_request_sco_can_send_now_event(void){
630     hci_stack->sco_waiting_for_can_send_now = 1;
631     hci_notify_if_sco_can_send_now();
632 }
633 #endif
634 
635 // used for internal checks in l2cap.c
636 int hci_is_packet_buffer_reserved(void){
637     return hci_stack->hci_packet_buffer_reserved;
638 }
639 
640 // reserves outgoing packet buffer. @returns 1 if successful
641 int hci_reserve_packet_buffer(void){
642     if (hci_stack->hci_packet_buffer_reserved) {
643         log_error("hci_reserve_packet_buffer called but buffer already reserved");
644         return 0;
645     }
646     hci_stack->hci_packet_buffer_reserved = 1;
647     return 1;
648 }
649 
650 void hci_release_packet_buffer(void){
651     hci_stack->hci_packet_buffer_reserved = 0;
652 }
653 
654 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
655 static int hci_transport_synchronous(void){
656     return hci_stack->hci_transport->can_send_packet_now == NULL;
657 }
658 
659 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
660 
661     // 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);
662 
663     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
664     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
665     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0u)){
666         max_acl_data_packet_length = hci_stack->le_data_packets_length;
667     }
668 
669 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
670     if (hci_is_le_connection(connection)){
671         max_acl_data_packet_length = connection->le_max_tx_octets;
672     }
673 #endif
674 
675     log_debug("hci_send_acl_packet_fragments entered");
676 
677     int err;
678     // multiple packets could be send on a synchronous HCI transport
679     while (true){
680 
681         log_debug("hci_send_acl_packet_fragments loop entered");
682 
683         // get current data
684         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4u;
685         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
686         int more_fragments = 0;
687 
688         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
689         if (current_acl_data_packet_length > max_acl_data_packet_length){
690             more_fragments = 1;
691             current_acl_data_packet_length = max_acl_data_packet_length;
692         }
693 
694         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
695         if (acl_header_pos > 0u){
696             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
697             handle_and_flags = (handle_and_flags & 0xcfffu) | (1u << 12u);
698             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
699         }
700 
701         // update header len
702         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2u, current_acl_data_packet_length);
703 
704         // count packet
705         connection->num_packets_sent++;
706         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", more_fragments);
707 
708         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
709         if (more_fragments){
710             // update start of next fragment to send
711             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
712         } else {
713             // done
714             hci_stack->acl_fragmentation_pos = 0;
715             hci_stack->acl_fragmentation_total_size = 0;
716         }
717 
718         // send packet
719         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
720         const int size = current_acl_data_packet_length + 4;
721         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
722         hci_stack->acl_fragmentation_tx_active = 1;
723         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
724 
725         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", more_fragments);
726 
727         // done yet?
728         if (!more_fragments) break;
729 
730         // can send more?
731         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
732     }
733 
734     log_debug("hci_send_acl_packet_fragments loop over");
735 
736     // release buffer now for synchronous transport
737     if (hci_transport_synchronous()){
738         hci_stack->acl_fragmentation_tx_active = 0;
739         hci_release_packet_buffer();
740         hci_emit_transport_packet_sent();
741     }
742 
743     return err;
744 }
745 
746 // pre: caller has reserved the packet buffer
747 int hci_send_acl_packet_buffer(int size){
748 
749     // log_info("hci_send_acl_packet_buffer size %u", size);
750 
751     if (!hci_stack->hci_packet_buffer_reserved) {
752         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
753         return 0;
754     }
755 
756     uint8_t * packet = hci_stack->hci_packet_buffer;
757     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
758 
759     // check for free places on Bluetooth module
760     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
761         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
762         hci_release_packet_buffer();
763         hci_emit_transport_packet_sent();
764         return BTSTACK_ACL_BUFFERS_FULL;
765     }
766 
767     hci_connection_t *connection = hci_connection_for_handle( con_handle);
768     if (!connection) {
769         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
770         hci_release_packet_buffer();
771         hci_emit_transport_packet_sent();
772         return 0;
773     }
774 
775 #ifdef ENABLE_CLASSIC
776     hci_connection_timestamp(connection);
777 #endif
778 
779     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
780 
781     // setup data
782     hci_stack->acl_fragmentation_total_size = size;
783     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
784 
785     return hci_send_acl_packet_fragments(connection);
786 }
787 
788 #ifdef ENABLE_CLASSIC
789 // pre: caller has reserved the packet buffer
790 int hci_send_sco_packet_buffer(int size){
791 
792     // log_info("hci_send_acl_packet_buffer size %u", size);
793 
794     if (!hci_stack->hci_packet_buffer_reserved) {
795         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
796         return 0;
797     }
798 
799     uint8_t * packet = hci_stack->hci_packet_buffer;
800 
801     // skip checks in loopback mode
802     if (!hci_stack->loopback_mode){
803         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
804 
805         // check for free places on Bluetooth module
806         if (!hci_can_send_prepared_sco_packet_now()) {
807             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
808             hci_release_packet_buffer();
809             hci_emit_transport_packet_sent();
810             return BTSTACK_ACL_BUFFERS_FULL;
811         }
812 
813         // track send packet in connection struct
814         hci_connection_t *connection = hci_connection_for_handle( con_handle);
815         if (!connection) {
816             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
817             hci_release_packet_buffer();
818             hci_emit_transport_packet_sent();
819             return 0;
820         }
821 
822         if (hci_have_usb_transport()){
823             // token used
824             hci_stack->sco_can_send_now = 0;
825         } else {
826             if (hci_stack->synchronous_flow_control_enabled){
827                 connection->num_packets_sent++;
828             } else {
829                 connection->sco_tx_ready--;
830             }
831         }
832     }
833 
834     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
835     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
836 
837     if (hci_transport_synchronous()){
838         hci_release_packet_buffer();
839         hci_emit_transport_packet_sent();
840     }
841 
842     return err;
843 }
844 #endif
845 
846 static void acl_handler(uint8_t *packet, uint16_t size){
847 
848     // get info
849     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
850     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
851     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
852     uint16_t acl_length         = READ_ACL_LENGTH(packet);
853 
854     // ignore non-registered handle
855     if (!conn){
856         log_error("acl_handler called with non-registered handle %u!" , con_handle);
857         return;
858     }
859 
860     // assert packet is complete
861     if ((acl_length + 4u) != size){
862         log_error("acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
863         return;
864     }
865 
866 #ifdef ENABLE_CLASSIC
867     // update idle timestamp
868     hci_connection_timestamp(conn);
869 #endif
870 
871 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
872     hci_stack->host_completed_packets = 1;
873     conn->num_packets_completed++;
874 #endif
875 
876     // handle different packet types
877     switch (acl_flags & 0x03u) {
878 
879         case 0x01: // continuation fragment
880 
881             // sanity checks
882             if (conn->acl_recombination_pos == 0u) {
883                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
884                 return;
885             }
886             if ((conn->acl_recombination_pos + acl_length) > (4u + HCI_ACL_BUFFER_SIZE)){
887                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
888                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
889                 conn->acl_recombination_pos = 0;
890                 return;
891             }
892 
893             // append fragment payload (header already stored)
894             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
895                          &packet[4], acl_length);
896             conn->acl_recombination_pos += acl_length;
897 
898             // forward complete L2CAP packet if complete.
899             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4u + 4u)){ // pos already incl. ACL header
900                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
901                 // reset recombination buffer
902                 conn->acl_recombination_length = 0;
903                 conn->acl_recombination_pos = 0;
904             }
905             break;
906 
907         case 0x02: { // first fragment
908 
909             // sanity check
910             if (conn->acl_recombination_pos) {
911                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
912                 conn->acl_recombination_pos = 0;
913             }
914 
915             // peek into L2CAP packet!
916             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
917 
918             // compare fragment size to L2CAP packet size
919             if (acl_length >= (l2cap_length + 4u)){
920                 // forward fragment as L2CAP packet
921                 hci_emit_acl_packet(packet, acl_length + 4u);
922             } else {
923 
924                 if (acl_length > HCI_ACL_BUFFER_SIZE){
925                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
926                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
927                     return;
928                 }
929 
930                 // store first fragment and tweak acl length for complete package
931                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
932                              packet, acl_length + 4u);
933                 conn->acl_recombination_pos    = acl_length + 4u;
934                 conn->acl_recombination_length = l2cap_length;
935                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2u, l2cap_length +4u);
936             }
937             break;
938 
939         }
940         default:
941             log_error( "acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
942             return;
943     }
944 
945     // execute main loop
946     hci_run();
947 }
948 
949 static void hci_shutdown_connection(hci_connection_t *conn){
950     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
951 
952 #ifdef ENABLE_CLASSIC
953 #ifdef ENABLE_SCO_OVER_HCI
954     int addr_type = conn->address_type;
955 #endif
956 #endif
957 
958     btstack_run_loop_remove_timer(&conn->timeout);
959 
960     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
961     btstack_memory_hci_connection_free( conn );
962 
963     // now it's gone
964     hci_emit_nr_connections_changed();
965 
966 #ifdef ENABLE_CLASSIC
967 #ifdef ENABLE_SCO_OVER_HCI
968     // update SCO
969     if (addr_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
970         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
971     }
972 #endif
973 #endif
974 }
975 
976 #ifdef ENABLE_CLASSIC
977 
978 static const uint16_t packet_type_sizes[] = {
979     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
980     HCI_ACL_DH1_SIZE, 0, 0, 0,
981     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
982     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
983 };
984 static const uint8_t  packet_type_feature_requirement_bit[] = {
985      0, // 3 slot packets
986      1, // 5 slot packets
987     25, // EDR 2 mpbs
988     26, // EDR 3 mbps
989     39, // 3 slot EDR packts
990     40, // 5 slot EDR packet
991 };
992 static const uint16_t packet_type_feature_packet_mask[] = {
993     0x0f00, // 3 slot packets
994     0xf000, // 5 slot packets
995     0x1102, // EDR 2 mpbs
996     0x2204, // EDR 3 mbps
997     0x0300, // 3 slot EDR packts
998     0x3000, // 5 slot EDR packet
999 };
1000 
1001 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
1002     // enable packet types based on size
1003     uint16_t packet_types = 0;
1004     unsigned int i;
1005     for (i=0;i<16;i++){
1006         if (packet_type_sizes[i] == 0) continue;
1007         if (packet_type_sizes[i] <= buffer_size){
1008             packet_types |= 1 << i;
1009         }
1010     }
1011     // disable packet types due to missing local supported features
1012     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1013         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1014         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1015         if (feature_set) continue;
1016         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1017         packet_types &= ~packet_type_feature_packet_mask[i];
1018     }
1019     // flip bits for "may not be used"
1020     packet_types ^= 0x3306;
1021     return packet_types;
1022 }
1023 
1024 uint16_t hci_usable_acl_packet_types(void){
1025     return hci_stack->packet_types;
1026 }
1027 #endif
1028 
1029 uint8_t* hci_get_outgoing_packet_buffer(void){
1030     // hci packet buffer is >= acl data packet length
1031     return hci_stack->hci_packet_buffer;
1032 }
1033 
1034 uint16_t hci_max_acl_data_packet_length(void){
1035     return hci_stack->acl_data_packet_length;
1036 }
1037 
1038 #ifdef ENABLE_CLASSIC
1039 int hci_extended_sco_link_supported(void){
1040     // No. 31, byte 3, bit 7
1041     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1042 }
1043 #endif
1044 
1045 int hci_non_flushable_packet_boundary_flag_supported(void){
1046     // No. 54, byte 6, bit 6
1047     return (hci_stack->local_supported_features[6u] & (1u << 6u)) != 0u;
1048 }
1049 
1050 static int gap_ssp_supported(void){
1051     // No. 51, byte 6, bit 3
1052     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1053 }
1054 
1055 static int hci_classic_supported(void){
1056 #ifdef ENABLE_CLASSIC
1057     // No. 37, byte 4, bit 5, = No BR/EDR Support
1058     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1059 #else
1060     return 0;
1061 #endif
1062 }
1063 
1064 static int hci_le_supported(void){
1065 #ifdef ENABLE_BLE
1066     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1067     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1068 #else
1069     return 0;
1070 #endif
1071 }
1072 
1073 #ifdef ENABLE_BLE
1074 
1075 /**
1076  * @brief Get addr type and address used for LE in Advertisements, Scan Responses,
1077  */
1078 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1079     *addr_type = hci_stack->le_own_addr_type;
1080     if (hci_stack->le_own_addr_type){
1081         (void)memcpy(addr, hci_stack->le_random_address, 6);
1082     } else {
1083         (void)memcpy(addr, hci_stack->local_bd_addr, 6);
1084     }
1085 }
1086 
1087 #ifdef ENABLE_LE_CENTRAL
1088 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1089 
1090     int offset = 3;
1091     int num_reports = packet[offset];
1092     offset += 1;
1093 
1094     int i;
1095     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1096     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1097     for (i=0; (i<num_reports) && (offset < size);i++){
1098         // sanity checks on data_length:
1099         uint8_t data_length = packet[offset + 8];
1100         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1101         if ((offset + 9u + data_length + 1u) > size)    return;
1102         // setup event
1103         uint8_t event_size = 10u + data_length;
1104         int pos = 0;
1105         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1106         event[pos++] = event_size;
1107         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1108         offset += 8;
1109         pos += 8;
1110         event[pos++] = packet[offset + 1 + data_length]; // rssi
1111         event[pos++] = data_length;
1112         offset++;
1113         (void)memcpy(&event[pos], &packet[offset], data_length);
1114         pos +=    data_length;
1115         offset += data_length + 1u; // rssi
1116         hci_emit_event(event, pos, 1);
1117     }
1118 }
1119 #endif
1120 #endif
1121 
1122 #ifdef ENABLE_BLE
1123 #ifdef ENABLE_LE_PERIPHERAL
1124 static void hci_update_advertisements_enabled_for_current_roles(void){
1125     if (hci_stack->le_advertisements_enabled){
1126         // get number of active le slave connections
1127         int num_slave_connections = 0;
1128         btstack_linked_list_iterator_t it;
1129         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1130         while (btstack_linked_list_iterator_has_next(&it)){
1131             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1132             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1133             if (con->state != OPEN) continue;
1134             if (con->role  != HCI_ROLE_SLAVE) continue;
1135             if (!hci_is_le_connection(con)) continue;
1136             num_slave_connections++;
1137         }
1138         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1139         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1140     } else {
1141         hci_stack->le_advertisements_enabled_for_current_roles = false;
1142     }
1143 }
1144 #endif
1145 #endif
1146 
1147 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1148 
1149 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1150     if (!hci_stack->config) return 0;
1151     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1152     // Limit baud rate for Broadcom chipsets to 3 mbps
1153     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1154         baud_rate = 3000000;
1155     }
1156     return baud_rate;
1157 }
1158 
1159 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1160     UNUSED(ds);
1161 
1162     switch (hci_stack->substate){
1163         case HCI_INIT_W4_SEND_RESET:
1164             log_info("Resend HCI Reset");
1165             hci_stack->substate = HCI_INIT_SEND_RESET;
1166             hci_stack->num_cmd_packets = 1;
1167             hci_run();
1168             break;
1169         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1170             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1171             if (hci_stack->hci_transport->reset_link){
1172                 hci_stack->hci_transport->reset_link();
1173             }
1174 
1175             /* fall through */
1176 
1177         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1178             log_info("Resend HCI Reset - CSR Warm Boot");
1179             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1180             hci_stack->num_cmd_packets = 1;
1181             hci_run();
1182             break;
1183         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1184             if (hci_stack->hci_transport->set_baudrate){
1185                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1186                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1187                 hci_stack->hci_transport->set_baudrate(baud_rate);
1188             }
1189             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1190             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1191                 if (hci_stack->hci_transport->reset_link){
1192                     log_info("Link Reset");
1193                     hci_stack->hci_transport->reset_link();
1194                 }
1195                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1196                 hci_run();
1197             }
1198             break;
1199         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1200             // otherwise continue
1201             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1202             hci_send_cmd(&hci_read_local_supported_commands);
1203             break;
1204         default:
1205             break;
1206     }
1207 }
1208 #endif
1209 
1210 static void hci_initializing_next_state(void){
1211     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1212 }
1213 
1214 // assumption: hci_can_send_command_packet_now() == true
1215 static void hci_initializing_run(void){
1216     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1217     switch (hci_stack->substate){
1218         case HCI_INIT_SEND_RESET:
1219             hci_state_reset();
1220 
1221 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1222             // prepare reset if command complete not received in 100ms
1223             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1224             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1225             btstack_run_loop_add_timer(&hci_stack->timeout);
1226 #endif
1227             // send command
1228             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1229             hci_send_cmd(&hci_reset);
1230             break;
1231         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1232             hci_send_cmd(&hci_read_local_version_information);
1233             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1234             break;
1235         case HCI_INIT_SEND_READ_LOCAL_NAME:
1236             hci_send_cmd(&hci_read_local_name);
1237             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1238             break;
1239 
1240 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1241         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1242             hci_state_reset();
1243             // prepare reset if command complete not received in 100ms
1244             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1245             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1246             btstack_run_loop_add_timer(&hci_stack->timeout);
1247             // send command
1248             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1249             hci_send_cmd(&hci_reset);
1250             break;
1251         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1252             hci_state_reset();
1253             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1254             hci_send_cmd(&hci_reset);
1255             break;
1256         case HCI_INIT_SEND_BAUD_CHANGE: {
1257             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1258             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1259             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1260             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1261             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1262             // STLC25000D: baudrate change happens within 0.5 s after command was send,
1263             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1264             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1265                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1266                 btstack_run_loop_add_timer(&hci_stack->timeout);
1267             }
1268             break;
1269         }
1270         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1271             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1272             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1273             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1274             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1275             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1276             break;
1277         }
1278         case HCI_INIT_CUSTOM_INIT:
1279             // Custom initialization
1280             if (hci_stack->chipset && hci_stack->chipset->next_command){
1281                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1282                 int send_cmd = 0;
1283                 switch (hci_stack->chipset_result){
1284                     case BTSTACK_CHIPSET_VALID_COMMAND:
1285                         send_cmd = 1;
1286                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1287                         break;
1288                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1289                         send_cmd = 1;
1290                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1291                         log_info("CSR Warm Boot");
1292                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1293                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1294                         btstack_run_loop_add_timer(&hci_stack->timeout);
1295                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1296                             && hci_stack->config
1297                             && hci_stack->chipset
1298                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1299                             && hci_stack->hci_transport->set_baudrate
1300                             && hci_transport_uart_get_main_baud_rate()){
1301                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1302                         } else {
1303                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1304                         }
1305                         break;
1306                     default:
1307                         break;
1308                 }
1309 
1310                 if (send_cmd){
1311                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1312                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1313                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1314                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1315                     break;
1316                 }
1317                 log_info("Init script done");
1318 
1319                 // Init script download on Broadcom chipsets causes:
1320                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1321                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1322                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1323 
1324                     // - baud rate to reset, restore UART baud rate if needed
1325                     int need_baud_change = hci_stack->config
1326                         && hci_stack->chipset
1327                         && hci_stack->chipset->set_baudrate_command
1328                         && hci_stack->hci_transport->set_baudrate
1329                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1330                     if (need_baud_change) {
1331                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1332                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1333                         hci_stack->hci_transport->set_baudrate(baud_rate);
1334                     }
1335 
1336                     uint16_t bcm_delay_ms = 300;
1337                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1338                     //   -> Work around: wait here.
1339                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1340                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1341                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1342                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1343                     btstack_run_loop_add_timer(&hci_stack->timeout);
1344                     break;
1345                 }
1346             }
1347             // otherwise continue
1348             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1349             hci_send_cmd(&hci_read_local_supported_commands);
1350             break;
1351         case HCI_INIT_SET_BD_ADDR:
1352             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1353             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1354             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1355             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1356             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1357             break;
1358 #endif
1359 
1360         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1361             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1362             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1363             hci_send_cmd(&hci_read_local_supported_commands);
1364             break;
1365         case HCI_INIT_READ_BD_ADDR:
1366             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1367             hci_send_cmd(&hci_read_bd_addr);
1368             break;
1369         case HCI_INIT_READ_BUFFER_SIZE:
1370             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1371             hci_send_cmd(&hci_read_buffer_size);
1372             break;
1373         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1374             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1375             hci_send_cmd(&hci_read_local_supported_features);
1376             break;
1377 
1378 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1379         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1380             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1381             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1382             break;
1383         case HCI_INIT_HOST_BUFFER_SIZE:
1384             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1385             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1386                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1387             break;
1388 #endif
1389 
1390         case HCI_INIT_SET_EVENT_MASK:
1391             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1392             if (hci_le_supported()){
1393                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1394             } else {
1395                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1396                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1397             }
1398             break;
1399 
1400 #ifdef ENABLE_CLASSIC
1401         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1402             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1403             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1404             break;
1405         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1406             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1407             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1408             break;
1409         case HCI_INIT_WRITE_DEFAULT_LINK_POLICY_SETTING:
1410             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_LINK_POLICY_SETTING;
1411             hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1412             break;
1413         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1414             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1415             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1416             break;
1417         case HCI_INIT_WRITE_LOCAL_NAME: {
1418             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1419             hci_reserve_packet_buffer();
1420             uint8_t * packet = hci_stack->hci_packet_buffer;
1421             // construct HCI Command and send
1422             uint16_t opcode = hci_write_local_name.opcode;
1423             hci_stack->last_cmd_opcode = opcode;
1424             packet[0] = opcode & 0xff;
1425             packet[1] = opcode >> 8;
1426             packet[2] = DEVICE_NAME_LEN;
1427             memset(&packet[3], 0, DEVICE_NAME_LEN);
1428             uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1429             uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1430             // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1431             (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1432             // expand '00:00:00:00:00:00' in name with bd_addr
1433             btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1434             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1435             break;
1436         }
1437         case HCI_INIT_WRITE_EIR_DATA: {
1438             hci_stack->substate = HCI_INIT_W4_WRITE_EIR_DATA;
1439             hci_reserve_packet_buffer();
1440             uint8_t * packet = hci_stack->hci_packet_buffer;
1441             // construct HCI Command in-place and send
1442             uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1443             hci_stack->last_cmd_opcode = opcode;
1444             uint16_t offset = 0;
1445             packet[offset++] = opcode & 0xff;
1446             packet[offset++] = opcode >> 8;
1447             packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1448             packet[offset++] = 0;  // FEC not required
1449             memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1450             if (hci_stack->eir_data){
1451                 // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1452                 ad_context_t context;
1453                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1454                     uint8_t data_type   = ad_iterator_get_data_type(&context);
1455                     uint8_t size        = ad_iterator_get_data_len(&context);
1456                     const uint8_t *data = ad_iterator_get_data(&context);
1457                     // copy item
1458                     packet[offset++] = size + 1;
1459                     packet[offset++] = data_type;
1460                     memcpy(&packet[offset], data, size);
1461                     // update name item
1462                     if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1463                         btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1464                     }
1465                     offset += size;
1466                 }
1467             } else {
1468                 uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1469                 uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1470                 packet[offset++] = bytes_to_copy + 1;
1471                 packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1472                 (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1473                 // expand '00:00:00:00:00:00' in name with bd_addr
1474                 btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1475             }
1476             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1477             break;
1478         }
1479         case HCI_INIT_WRITE_INQUIRY_MODE:
1480             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1481             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1482             break;
1483         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1484             hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1485 			hci_stack->secure_connections_active = true;
1486             hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1487             break;
1488         case HCI_INIT_WRITE_SCAN_ENABLE:
1489             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1490             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1491             break;
1492         // only sent if ENABLE_SCO_OVER_HCI is defined
1493         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1494             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1495             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1496             break;
1497         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1498             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1499             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1500             break;
1501         // only sent if ENABLE_SCO_OVER_HCI and manufacturer is Broadcom
1502         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1503             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1504             log_info("BCM: Route SCO data via HCI transport");
1505             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1506             break;
1507 
1508 #endif
1509 #ifdef ENABLE_BLE
1510         // LE INIT
1511         case HCI_INIT_LE_READ_BUFFER_SIZE:
1512             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1513             hci_send_cmd(&hci_le_read_buffer_size);
1514             break;
1515         case HCI_INIT_LE_SET_EVENT_MASK:
1516             hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1517             hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1518             break;
1519         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1520             // LE Supported Host = 1, Simultaneous Host = 0
1521             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1522             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1523             break;
1524 #endif
1525 
1526 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1527         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1528             hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1529             hci_send_cmd(&hci_le_read_maximum_data_length);
1530             break;
1531         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1532             hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1533             hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1534             break;
1535 #endif
1536 
1537 #ifdef ENABLE_LE_CENTRAL
1538         case HCI_INIT_READ_WHITE_LIST_SIZE:
1539             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1540             hci_send_cmd(&hci_le_read_white_list_size);
1541             break;
1542         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1543             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1544             hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
1545             break;
1546 #endif
1547         default:
1548             return;
1549     }
1550 }
1551 
1552 static void hci_init_done(void){
1553     // done. tell the app
1554     log_info("hci_init_done -> HCI_STATE_WORKING");
1555     hci_stack->state = HCI_STATE_WORKING;
1556     hci_emit_state();
1557     hci_run();
1558 }
1559 
1560 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1561     bool command_completed = false;
1562     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1563         uint16_t opcode = little_endian_read_16(packet,3);
1564         if (opcode == hci_stack->last_cmd_opcode){
1565             command_completed = true;
1566             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1567         } else {
1568             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1569         }
1570     }
1571 
1572     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1573         uint8_t  status = packet[2];
1574         uint16_t opcode = little_endian_read_16(packet,4);
1575         if (opcode == hci_stack->last_cmd_opcode){
1576             if (status){
1577                 command_completed = true;
1578                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1579             } else {
1580                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1581             }
1582         } else {
1583             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1584         }
1585     }
1586 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1587     // Vendor == CSR
1588     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1589         // TODO: track actual command
1590         command_completed = true;
1591     }
1592 
1593     // Vendor == Toshiba
1594     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1595         // TODO: track actual command
1596         command_completed = true;
1597         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1598         hci_stack->num_cmd_packets = 1;
1599     }
1600 #endif
1601 
1602     return command_completed;
1603 }
1604 
1605 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1606 
1607     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1608 
1609     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1610 
1611 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1612 
1613     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1614     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1615     //
1616     // HCI Reset
1617     // Timeout 100 ms
1618     // HCI Reset
1619     // Command Complete Reset
1620     // HCI Read Local Version Information
1621     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1622     // hang...
1623     //
1624     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1625     if (!command_completed
1626             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1627             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1628 
1629         uint16_t opcode = little_endian_read_16(packet,3);
1630         if (opcode == hci_reset.opcode){
1631             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1632             return;
1633         }
1634     }
1635 
1636     // CSR & H5
1637     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1638     if (!command_completed
1639             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1640             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1641 
1642         uint16_t opcode = little_endian_read_16(packet,3);
1643         if (opcode == hci_reset.opcode){
1644             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1645             return;
1646         }
1647     }
1648 
1649     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1650     // fix: Correct substate and behave as command below
1651     if (command_completed){
1652         switch (hci_stack->substate){
1653             case HCI_INIT_SEND_RESET:
1654                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1655                 break;
1656             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1657                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1658                 break;
1659             default:
1660                 break;
1661         }
1662     }
1663 
1664 #endif
1665 
1666     if (!command_completed) return;
1667 
1668     bool need_baud_change = false;
1669     bool need_addr_change = false;
1670 
1671 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1672     need_baud_change = hci_stack->config
1673                         && hci_stack->chipset
1674                         && hci_stack->chipset->set_baudrate_command
1675                         && hci_stack->hci_transport->set_baudrate
1676                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1677 
1678     need_addr_change = hci_stack->custom_bd_addr_set
1679                         && hci_stack->chipset
1680                         && hci_stack->chipset->set_bd_addr_command;
1681 #endif
1682 
1683     switch(hci_stack->substate){
1684 
1685 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1686         case HCI_INIT_SEND_RESET:
1687             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1688             // fix: just correct substate and behave as command below
1689             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1690             btstack_run_loop_remove_timer(&hci_stack->timeout);
1691             break;
1692         case HCI_INIT_W4_SEND_RESET:
1693             btstack_run_loop_remove_timer(&hci_stack->timeout);
1694             break;
1695         case HCI_INIT_W4_SEND_READ_LOCAL_NAME:
1696             log_info("Received local name, need baud change %d", (int) need_baud_change);
1697             if (need_baud_change){
1698                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1699                 return;
1700             }
1701             // skip baud change
1702             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1703             return;
1704         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1705             // for STLC2500D, baud rate change already happened.
1706             // for others, baud rate gets changed now
1707             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1708                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1709                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1710                 hci_stack->hci_transport->set_baudrate(baud_rate);
1711             }
1712             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1713             return;
1714         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1715             btstack_run_loop_remove_timer(&hci_stack->timeout);
1716             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1717             return;
1718         case HCI_INIT_W4_CUSTOM_INIT:
1719             // repeat custom init
1720             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1721             return;
1722 #else
1723         case HCI_INIT_W4_SEND_RESET:
1724             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1725             return ;
1726 #endif
1727 
1728         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1729             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1730               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1731                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1732                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1733                 return;
1734             }
1735             if (need_addr_change){
1736                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1737                 return;
1738             }
1739             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1740             return;
1741 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1742         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1743             if (need_baud_change){
1744                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1745                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
1746                 hci_stack->hci_transport->set_baudrate(baud_rate);
1747             }
1748             if (need_addr_change){
1749                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1750                 return;
1751             }
1752             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1753             return;
1754         case HCI_INIT_W4_SET_BD_ADDR:
1755             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1756             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1757             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1758                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1759                 return;
1760             }
1761             // skipping st warm boot
1762             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1763             return;
1764         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1765             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1766             return;
1767 #endif
1768         case HCI_INIT_W4_READ_BD_ADDR:
1769             // only read buffer size if supported
1770             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1771                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1772                 return;
1773             }
1774             // skipping read buffer size
1775             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1776             return;
1777         case HCI_INIT_W4_SET_EVENT_MASK:
1778             // skip Classic init commands for LE only chipsets
1779             if (!hci_classic_supported()){
1780 #ifdef ENABLE_BLE
1781                 if (hci_le_supported()){
1782                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1783                     return;
1784                 }
1785 #endif
1786                 log_error("Neither BR/EDR nor LE supported");
1787                 hci_init_done();
1788                 return;
1789             }
1790             if (!gap_ssp_supported()){
1791                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1792                 return;
1793             }
1794             break;
1795 #ifdef ENABLE_BLE
1796         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1797             // skip write le host if not supported (e.g. on LE only EM9301)
1798             if (hci_stack->local_supported_commands[0u] & 0x02u) break;
1799             hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1800             return;
1801 
1802 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1803         case HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED:
1804             log_info("Supported commands %x", hci_stack->local_supported_commands[0] & 0x30);
1805             if ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u){
1806                 hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1807                 return;
1808             }
1809             // explicit fall through to reduce repetitions
1810 
1811 #ifdef ENABLE_LE_CENTRAL
1812             hci_stack->substate = HCI_INIT_READ_WHITE_LIST_SIZE;
1813 #else
1814             hci_init_done();
1815 #endif
1816             return;
1817 #endif  /* ENABLE_LE_DATA_LENGTH_EXTENSION */
1818 
1819 #endif  /* ENABLE_BLE */
1820 
1821         case HCI_INIT_W4_WRITE_INQUIRY_MODE:
1822             // skip write secure connections host support if not supported or disabled
1823             if (!hci_stack->secure_connections_enable || (hci_stack->local_supported_commands[1u] & 0x02u) == 0u) {
1824                 hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;
1825                 return;
1826             }
1827             break;
1828 
1829 #ifdef ENABLE_SCO_OVER_HCI
1830         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1831             // skip write synchronous flow control if not supported
1832             if (hci_stack->local_supported_commands[0] & 0x04) break;
1833             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1834 
1835             /* fall through */
1836 
1837         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1838             // skip write default erroneous data reporting if not supported
1839             if (hci_stack->local_supported_commands[0] & 0x08) break;
1840             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1841 
1842             /* fall through */
1843 
1844         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1845             // skip bcm set sco pcm config on non-Broadcom chipsets
1846             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) break;
1847             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1848 
1849             /* fall through */
1850 
1851         case HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT:
1852             if (!hci_le_supported()){
1853                 // SKIP LE init for Classic only configuration
1854                 hci_init_done();
1855                 return;
1856             }
1857             break;
1858 
1859 #else /* !ENABLE_SCO_OVER_HCI */
1860 
1861         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1862 #ifdef ENABLE_BLE
1863             if (hci_le_supported()){
1864                 hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE;
1865                 return;
1866             }
1867 #endif
1868             // SKIP LE init for Classic only configuration
1869             hci_init_done();
1870             return;
1871 #endif /* ENABLE_SCO_OVER_HCI */
1872 
1873 // avoid compile error due to duplicate cases: HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT == HCI_INIT_DONE-1
1874 #if defined(ENABLE_BLE) || defined(ENABLE_LE_DATA_LENGTH_EXTENSION) || defined(ENABLE_LE_CENTRAL)
1875         // Response to command before init done state -> init done
1876         case (HCI_INIT_DONE-1):
1877             hci_init_done();
1878             return;
1879 #endif
1880 
1881         default:
1882             break;
1883     }
1884     hci_initializing_next_state();
1885 }
1886 
1887 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
1888     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
1889     bd_addr_t bd_address;
1890     (void)memcpy(&bd_address, conn->address, 6);
1891 
1892 #ifdef ENABLE_CLASSIC
1893     // cache needed data
1894     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1895 #endif
1896 
1897     // connection failed, remove entry
1898     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1899     btstack_memory_hci_connection_free( conn );
1900 
1901 #ifdef ENABLE_CLASSIC
1902     // notify client if dedicated bonding
1903     if (notify_dedicated_bonding_failed){
1904         log_info("hci notify_dedicated_bonding_failed");
1905         hci_emit_dedicated_bonding_result(bd_address, status);
1906     }
1907 
1908     // if authentication error, also delete link key
1909     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
1910         gap_drop_link_key_for_bd_addr(bd_address);
1911     }
1912 #else
1913     UNUSED(status);
1914 #endif
1915 }
1916 
1917 #ifdef ENABLE_CLASSIC
1918 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
1919     // SSP Controller
1920     if (features[6] & (1 << 3)){
1921         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
1922     }
1923     // eSCO
1924     if (features[3] & (1<<7)){
1925         conn->remote_supported_features[0] |= 1;
1926     }
1927     // Extended features
1928     if (features[7] & (1<<7)){
1929         conn->remote_supported_features[0] |= 2;
1930     }
1931 }
1932 
1933 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
1934     // SSP Host
1935     if (features[0] & (1 << 0)){
1936         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
1937     }
1938     // SC Host
1939     if (features[0] & (1 << 3)){
1940         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
1941     }
1942 }
1943 
1944 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
1945     // SC Controller
1946     if (features[1] & (1 << 0)){
1947         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
1948     }
1949 }
1950 
1951 static void hci_handle_remote_features_received(hci_connection_t * conn){
1952     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1953     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
1954     if (conn->bonding_flags & BONDING_DEDICATED){
1955         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1956     }
1957 }
1958 #endif
1959 
1960 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
1961     // handle BT initialization
1962     if (hci_stack->state == HCI_STATE_INITIALIZING) {
1963         hci_initializing_event_handler(packet, size);
1964     }
1965 
1966     // help with BT sleep
1967     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
1968         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
1969         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
1970         hci_initializing_next_state();
1971     }
1972 }
1973 
1974 #ifdef ENABLE_CLASSIC
1975 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
1976     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1977     conn->encryption_key_size = encryption_key_size;
1978 
1979     if ((conn->authentication_flags & CONNECTION_AUTHENTICATED) != 0) {
1980         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
1981         return;
1982     }
1983 
1984     // Request Authentication if not already done
1985     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
1986     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1987 }
1988 #endif
1989 
1990 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
1991     UNUSED(size);
1992 
1993     uint16_t manufacturer;
1994 #ifdef ENABLE_CLASSIC
1995     hci_con_handle_t handle;
1996     hci_connection_t * conn;
1997     uint8_t status;
1998 #endif
1999     // get num cmd packets - limit to 1 to reduce complexity
2000     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2001 
2002     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
2003     switch (opcode){
2004         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
2005             if (packet[5]) break;
2006             // terminate, name 248 chars
2007             packet[6+248] = 0;
2008             log_info("local name: %s", &packet[6]);
2009             break;
2010         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2011             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2012             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2013                 uint16_t acl_len = little_endian_read_16(packet, 6);
2014                 uint16_t sco_len = packet[8];
2015 
2016                 // determine usable ACL/SCO payload size
2017                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2018                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2019 
2020                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2021                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2022 
2023                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2024                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2025                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2026             }
2027             break;
2028         case HCI_OPCODE_HCI_READ_RSSI:
2029             if (packet[5] == ERROR_CODE_SUCCESS){
2030                 uint8_t event[5];
2031                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2032                 event[1] = 3;
2033                 (void)memcpy(&event[2], &packet[6], 3);
2034                 hci_emit_event(event, sizeof(event), 1);
2035             }
2036             break;
2037 #ifdef ENABLE_BLE
2038         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2039             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2040             hci_stack->le_acl_packets_total_num = packet[8];
2041             // determine usable ACL payload size
2042             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2043                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2044             }
2045             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2046             break;
2047 #endif
2048 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2049         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2050             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2051             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2052             log_info("hci_le_read_maximum_data_length: tx octets %u, tx time %u us", hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
2053             break;
2054 #endif
2055 #ifdef ENABLE_LE_CENTRAL
2056         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2057             hci_stack->le_whitelist_capacity = packet[6];
2058             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2059             break;
2060 #endif
2061         case HCI_OPCODE_HCI_READ_BD_ADDR:
2062             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2063             log_info("Local Address, Status: 0x%02x: Addr: %s", packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
2064 #ifdef ENABLE_CLASSIC
2065             if (hci_stack->link_key_db){
2066                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2067             }
2068 #endif
2069             break;
2070 #ifdef ENABLE_CLASSIC
2071         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2072             hci_emit_discoverable_enabled(hci_stack->discoverable);
2073             break;
2074         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2075             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2076                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2077                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2078                 hci_emit_event(event, sizeof(event), 1);
2079             }
2080             break;
2081 #endif
2082         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2083             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2084 
2085 #ifdef ENABLE_CLASSIC
2086             // determine usable ACL packet types based on host buffer size and supported features
2087             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2088             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2089 #endif
2090             // Classic/LE
2091             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2092             break;
2093         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2094             manufacturer = little_endian_read_16(packet, 10);
2095             // map Cypress to Broadcom
2096             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2097                 log_info("Treat Cypress as Broadcom");
2098                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2099                 little_endian_store_16(packet, 10, manufacturer);
2100             }
2101             hci_stack->manufacturer = manufacturer;
2102             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2103             break;
2104         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2105             hci_stack->local_supported_commands[0] =
2106                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit  0 = Octet 14, bit 7 / Read Buffer Size
2107                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit  1 = Octet 24, bit 6 / Write Le Host Supported
2108                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit  2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2109                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     )  |  // bit  3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2110                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit  4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2111                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit  5 = Octet 35, bit 3 / LE Read Maximum Data Length
2112                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit  6 = Octet 35, bit 5 / LE Set Default PHY
2113                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit  7 = Octet 20, bit 4 / Read Encryption Key Size
2114             hci_stack->local_supported_commands[1] =
2115                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit  8 = Octet  2, bit 6 / Read Remote Extended Features
2116                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u) |  // bit  9 = Octet 32, bit 3 / Write Secure Connections Host
2117                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x02u) << 1u);   // bit 10 = Octet 35, bit 1 / LE Set Address Resolution Enable
2118             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2119             break;
2120 #ifdef ENABLE_CLASSIC
2121         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2122             if (packet[5]) return;
2123             hci_stack->synchronous_flow_control_enabled = 1;
2124             break;
2125         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2126             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2127             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2128             conn   = hci_connection_for_handle(handle);
2129             if (conn != NULL) {
2130                 uint8_t key_size = 0;
2131                 if (status == 0){
2132                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2133                     log_info("Handle %04x key Size: %u", handle, key_size);
2134                 } else {
2135                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2136                 }
2137                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2138             }
2139             break;
2140 #endif
2141         default:
2142             break;
2143     }
2144 }
2145 
2146 #ifdef ENABLE_BLE
2147 static void event_handle_le_connection_complete(const uint8_t * packet){
2148 	bd_addr_t addr;
2149 	bd_addr_type_t addr_type;
2150 	hci_connection_t * conn;
2151 
2152 	// Connection management
2153 	reverse_bd_addr(&packet[8], addr);
2154 	addr_type = (bd_addr_type_t)packet[7];
2155 	log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2156 	conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2157 
2158 #ifdef ENABLE_LE_CENTRAL
2159 	// handle error: error is reported only to the initiator -> outgoing connection
2160 	if (packet[3]){
2161 
2162 		// handle cancelled outgoing connection
2163 		// "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2164 		//  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2165 		//  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2166 		if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2167 			// whitelist connect
2168 			if (hci_is_le_connection_type(addr_type)){
2169 				hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2170 				hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2171 			}
2172 			// get outgoing connection conn struct for direct connect
2173 			conn = gap_get_outgoing_connection();
2174 		}
2175 
2176 		// outgoing le connection establishment is done
2177 		if (conn){
2178 			// remove entry
2179 			btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2180 			btstack_memory_hci_connection_free( conn );
2181 		}
2182 		return;
2183 	}
2184 #endif
2185 
2186 	// on success, both hosts receive connection complete event
2187 	if (packet[6] == HCI_ROLE_MASTER){
2188 #ifdef ENABLE_LE_CENTRAL
2189 		// if we're master on an le connection, it was an outgoing connection and we're done with it
2190 		// note: no hci_connection_t object exists yet for connect with whitelist
2191 		if (hci_is_le_connection_type(addr_type)){
2192 			hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2193 			hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2194 		}
2195 #endif
2196 	} else {
2197 #ifdef ENABLE_LE_PERIPHERAL
2198 		// if we're slave, it was an incoming connection, advertisements have stopped
2199 		hci_stack->le_advertisements_active = false;
2200 #endif
2201 	}
2202 
2203 	// LE connections are auto-accepted, so just create a connection if there isn't one already
2204 	if (!conn){
2205 		conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2206 	}
2207 
2208 	// no memory, sorry.
2209 	if (!conn){
2210 		return;
2211 	}
2212 
2213 	conn->state = OPEN;
2214 	conn->role  = packet[6];
2215 	conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2216 	conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2217 
2218 #ifdef ENABLE_LE_PERIPHERAL
2219 	if (packet[6] == HCI_ROLE_SLAVE){
2220 		hci_update_advertisements_enabled_for_current_roles();
2221 	}
2222 #endif
2223 
2224     // init unenhanced att bearer mtu
2225     conn->att_connection.mtu = ATT_DEFAULT_MTU;
2226     conn->att_connection.mtu_exchanged = false;
2227 
2228     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2229 
2230 	// restart timer
2231 	// btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2232 	// btstack_run_loop_add_timer(&conn->timeout);
2233 
2234 	log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2235 
2236 	hci_emit_nr_connections_changed();
2237 }
2238 #endif
2239 
2240 static void event_handler(uint8_t *packet, uint16_t size){
2241 
2242     uint16_t event_length = packet[1];
2243 
2244     // assert packet is complete
2245     if (size != (event_length + 2u)){
2246         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2247         return;
2248     }
2249 
2250     bd_addr_type_t addr_type;
2251     hci_con_handle_t handle;
2252     hci_connection_t * conn;
2253     int i;
2254     int create_connection_cmd;
2255 
2256 #ifdef ENABLE_CLASSIC
2257     uint8_t link_type;
2258     bd_addr_t addr;
2259 #endif
2260 
2261     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2262 
2263     switch (hci_event_packet_get_type(packet)) {
2264 
2265         case HCI_EVENT_COMMAND_COMPLETE:
2266             handle_command_complete_event(packet, size);
2267             break;
2268 
2269         case HCI_EVENT_COMMAND_STATUS:
2270             // get num cmd packets - limit to 1 to reduce complexity
2271             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2272 
2273             // check command status to detected failed outgoing connections
2274             create_connection_cmd = 0;
2275 #ifdef ENABLE_CLASSIC
2276             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2277                 create_connection_cmd = 1;
2278             }
2279 #endif
2280 #ifdef ENABLE_LE_CENTRAL
2281             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2282                 create_connection_cmd = 1;
2283             }
2284 #endif
2285             if (create_connection_cmd) {
2286                 uint8_t status = hci_event_command_status_get_status(packet);
2287                 addr_type = hci_stack->outgoing_addr_type;
2288                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, addr_type);
2289                 log_info("command status (create connection), status %x, connection %p, addr %s, type %x", status, conn, bd_addr_to_str(hci_stack->outgoing_addr), addr_type);
2290 
2291                 // reset outgoing address info
2292                 memset(hci_stack->outgoing_addr, 0, 6);
2293                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2294 
2295                 // on error
2296                 if (status != ERROR_CODE_SUCCESS){
2297 #ifdef ENABLE_LE_CENTRAL
2298                     if (hci_is_le_connection_type(addr_type)){
2299                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2300                         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2301                     }
2302 #endif
2303                     // error => outgoing connection failed
2304                     if (conn != NULL){
2305                         hci_handle_connection_failed(conn, status);
2306                     }
2307                 }
2308             }
2309             break;
2310 
2311         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2312             if (size < 3) return;
2313             uint16_t num_handles = packet[2];
2314             if (size != (3u + num_handles * 4u)) return;
2315             uint16_t offset = 3;
2316             for (i=0; i<num_handles;i++){
2317                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2318                 offset += 2u;
2319                 uint16_t num_packets = little_endian_read_16(packet, offset);
2320                 offset += 2u;
2321 
2322                 conn = hci_connection_for_handle(handle);
2323                 if (!conn){
2324                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2325                     continue;
2326                 }
2327 
2328                 if (conn->num_packets_sent >= num_packets){
2329                     conn->num_packets_sent -= num_packets;
2330                 } else {
2331                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2332                     conn->num_packets_sent = 0;
2333                 }
2334                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2335 
2336 #ifdef ENABLE_CLASSIC
2337                 // For SCO, we do the can_send_now_check here
2338                 hci_notify_if_sco_can_send_now();
2339 #endif
2340             }
2341             break;
2342         }
2343 
2344 #ifdef ENABLE_CLASSIC
2345         case HCI_EVENT_INQUIRY_COMPLETE:
2346             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2347                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2348                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2349                 hci_emit_event(event, sizeof(event), 1);
2350             }
2351             break;
2352         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2353             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2354                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2355             }
2356             break;
2357         case HCI_EVENT_CONNECTION_REQUEST:
2358             reverse_bd_addr(&packet[2], addr);
2359             if (hci_stack->gap_classic_accept_callback != NULL){
2360                 if ((*hci_stack->gap_classic_accept_callback)(addr) == 0){
2361                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2362                     bd_addr_copy(hci_stack->decline_addr, addr);
2363                     break;
2364                 }
2365             }
2366 
2367             // TODO: eval COD 8-10
2368             link_type = packet[11];
2369             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
2370             addr_type = (link_type == 1) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2371             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2372             if (!conn) {
2373                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2374             }
2375             if (!conn) {
2376                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2377                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2378                 bd_addr_copy(hci_stack->decline_addr, addr);
2379                 break;
2380             }
2381             conn->role  = HCI_ROLE_SLAVE;
2382             conn->state = RECEIVED_CONNECTION_REQUEST;
2383             // store info about eSCO
2384             if (link_type == 0x02){
2385                 conn->remote_supported_features[0] |= 1;
2386             }
2387             hci_run();
2388             break;
2389 
2390         case HCI_EVENT_CONNECTION_COMPLETE:
2391             // Connection management
2392             reverse_bd_addr(&packet[5], addr);
2393             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2394             addr_type = BD_ADDR_TYPE_ACL;
2395             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2396             if (conn) {
2397                 if (!packet[2]){
2398                     conn->state = OPEN;
2399                     conn->con_handle = little_endian_read_16(packet, 3);
2400 
2401                     // queue get remote feature
2402                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2403 
2404                     // queue set supervision timeout if we're master
2405                     if ((hci_stack->link_supervision_timeout != 0) && (conn->role == HCI_ROLE_MASTER)){
2406                         connectionSetAuthenticationFlags(conn, WRITE_SUPERVISION_TIMEOUT);
2407                     }
2408 
2409                     // restart timer
2410                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2411                     btstack_run_loop_add_timer(&conn->timeout);
2412 
2413                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2414 
2415                     hci_emit_nr_connections_changed();
2416                 } else {
2417                     // connection failed
2418                     hci_handle_connection_failed(conn, packet[2]);
2419                 }
2420             }
2421             break;
2422 
2423         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2424             reverse_bd_addr(&packet[5], addr);
2425             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2426             if (packet[2]){
2427                 // connection failed
2428                 break;
2429             }
2430             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2431             if (!conn) {
2432                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2433             }
2434             if (!conn) {
2435                 break;
2436             }
2437             conn->state = OPEN;
2438             conn->con_handle = little_endian_read_16(packet, 3);
2439 
2440 #ifdef ENABLE_SCO_OVER_HCI
2441             // update SCO
2442             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2443                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2444             }
2445             // trigger can send now
2446             if (hci_have_usb_transport()){
2447                 hci_stack->sco_can_send_now = 1;
2448             }
2449 #endif
2450             break;
2451 
2452         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2453             handle = little_endian_read_16(packet, 3);
2454             conn = hci_connection_for_handle(handle);
2455             if (!conn) break;
2456             if (!packet[2]){
2457                 const uint8_t * features = &packet[5];
2458                 hci_handle_remote_features_page_0(conn, features);
2459 
2460                 // read extended features if possible
2461                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2462                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2463                     break;
2464                 }
2465             }
2466             hci_handle_remote_features_received(conn);
2467             break;
2468 
2469         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2470             handle = little_endian_read_16(packet, 3);
2471             conn = hci_connection_for_handle(handle);
2472             if (!conn) break;
2473             // status = ok, page = 1
2474             if (!packet[2]) {
2475                 uint8_t page_number = packet[5];
2476                 uint8_t maximum_page_number = packet[6];
2477                 const uint8_t * features = &packet[7];
2478                 bool done = false;
2479                 switch (page_number){
2480                     case 1:
2481                         hci_handle_remote_features_page_1(conn, features);
2482                         if (maximum_page_number >= 2){
2483                             // get Secure Connections (Controller) from Page 2 if available
2484                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2485                         } else {
2486                             // otherwise, assume SC (Controller) == SC (Host)
2487                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2488                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2489                             }
2490                             done = true;
2491                         }
2492                         break;
2493                     case 2:
2494                         hci_handle_remote_features_page_2(conn, features);
2495                         done = true;
2496                         break;
2497                     default:
2498                         break;
2499                 }
2500                 if (!done) break;
2501             }
2502             hci_handle_remote_features_received(conn);
2503             break;
2504 
2505         case HCI_EVENT_LINK_KEY_REQUEST:
2506             log_info("HCI_EVENT_LINK_KEY_REQUEST");
2507             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
2508             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
2509             if (hci_stack->bondable && !hci_stack->link_key_db) break;
2510             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
2511             hci_run();
2512             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
2513             return;
2514 
2515         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2516             reverse_bd_addr(&packet[2], addr);
2517             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2518             if (!conn) break;
2519             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
2520             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2521             // Change Connection Encryption keeps link key type
2522             if (link_key_type != CHANGED_COMBINATION_KEY){
2523                 conn->link_key_type = link_key_type;
2524             }
2525             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2526             // still forward event to allow dismiss of pairing dialog
2527             break;
2528         }
2529 
2530         case HCI_EVENT_PIN_CODE_REQUEST:
2531             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
2532             // non-bondable mode: pin code negative reply will be sent
2533             if (!hci_stack->bondable){
2534                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
2535                 hci_run();
2536                 return;
2537             }
2538             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
2539             if (!hci_stack->link_key_db) break;
2540             hci_event_pin_code_request_get_bd_addr(packet, addr);
2541             hci_stack->link_key_db->delete_link_key(addr);
2542             break;
2543 
2544         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2545             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
2546             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
2547             break;
2548 
2549         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2550             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2551             if (!hci_stack->ssp_auto_accept) break;
2552             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
2553             break;
2554 
2555         case HCI_EVENT_USER_PASSKEY_REQUEST:
2556             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2557             if (!hci_stack->ssp_auto_accept) break;
2558             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
2559             break;
2560         case HCI_EVENT_MODE_CHANGE:
2561             handle = hci_event_mode_change_get_handle(packet);
2562             conn = hci_connection_for_handle(handle);
2563             if (!conn) break;
2564             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2565             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2566             break;
2567 #endif
2568 
2569         case HCI_EVENT_ENCRYPTION_CHANGE:
2570             handle = hci_event_encryption_change_get_connection_handle(packet);
2571             conn = hci_connection_for_handle(handle);
2572             if (!conn) break;
2573             if (hci_event_encryption_change_get_status(packet) == 0u) {
2574                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2575                 if (encryption_enabled){
2576                     if (hci_is_le_connection(conn)){
2577                         // For LE, we accept connection as encrypted
2578                         conn->authentication_flags |= CONNECTION_ENCRYPTED;
2579                     }
2580 #ifdef ENABLE_CLASSIC
2581                     else {
2582                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
2583                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
2584                         bool connected_uses_aes_ccm = encryption_enabled == 2;
2585                         if (hci_stack->secure_connections_active && sc_used_during_pairing && !connected_uses_aes_ccm){
2586                             log_info("SC during pairing, but only E0 now -> abort");
2587                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2588                             break;
2589                         }
2590 
2591                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
2592                         if (connected_uses_aes_ccm){
2593                             conn->authentication_flags |= CONNECTION_AUTHENTICATED;
2594                         }
2595 
2596                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
2597                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
2598                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
2599                         } else {
2600                             // if not, pretend everything is perfect
2601                             hci_handle_read_encryption_key_size_complete(conn, 16);
2602                         }
2603                     }
2604 #endif
2605                 } else {
2606                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
2607                 }
2608             }
2609 
2610             break;
2611 
2612 #ifdef ENABLE_CLASSIC
2613         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
2614             handle = hci_event_authentication_complete_get_connection_handle(packet);
2615             conn = hci_connection_for_handle(handle);
2616             if (!conn) break;
2617 
2618             // ignore authentication event if we didn't request it
2619             if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) == 0) break;
2620 
2621             // dedicated bonding: send result and disconnect
2622             if (conn->bonding_flags & BONDING_DEDICATED){
2623                 conn->bonding_flags &= ~BONDING_DEDICATED;
2624                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
2625                 conn->bonding_status = packet[2];
2626                 break;
2627             }
2628 
2629             // authenticated only if auth status == 0
2630             if (hci_event_authentication_complete_get_status(packet) == 0){
2631                 // authenticated
2632                 conn->authentication_flags |= CONNECTION_AUTHENTICATED;
2633 
2634                 // If link key sufficient for requested security and not already encrypted, start encryption
2635                 if (((gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level)) &&
2636                     ((conn->authentication_flags & CONNECTION_ENCRYPTED) == 0)){
2637                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2638                     break;
2639                 }
2640             }
2641 
2642             // emit updated security level
2643             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
2644             break;
2645 #endif
2646 
2647         // HCI_EVENT_DISCONNECTION_COMPLETE
2648         // has been split, to first notify stack before shutting connection down
2649         // see end of function, too.
2650         case HCI_EVENT_DISCONNECTION_COMPLETE:
2651             if (packet[2]) break;   // status != 0
2652             handle = little_endian_read_16(packet, 3);
2653             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
2654             if (hci_stack->acl_fragmentation_total_size > 0u) {
2655                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
2656                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
2657                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
2658                     hci_stack->acl_fragmentation_total_size = 0;
2659                     hci_stack->acl_fragmentation_pos = 0;
2660                     if (release_buffer){
2661                         hci_release_packet_buffer();
2662                     }
2663                 }
2664             }
2665 
2666             conn = hci_connection_for_handle(handle);
2667             if (!conn) break;
2668             // mark connection for shutdown
2669             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
2670 
2671             // emit dedicatd bonding event
2672             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
2673                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
2674             }
2675 
2676 #ifdef ENABLE_BLE
2677 #ifdef ENABLE_LE_PERIPHERAL
2678             // re-enable advertisements for le connections if active
2679             if (hci_is_le_connection(conn)){
2680                 hci_update_advertisements_enabled_for_current_roles();
2681             }
2682 #endif
2683 #endif
2684             break;
2685 
2686         case HCI_EVENT_HARDWARE_ERROR:
2687             log_error("Hardware Error: 0x%02x", packet[2]);
2688             if (hci_stack->hardware_error_callback){
2689                 (*hci_stack->hardware_error_callback)(packet[2]);
2690             } else {
2691                 // if no special requests, just reboot stack
2692                 hci_power_control_off();
2693                 hci_power_control_on();
2694             }
2695             break;
2696 
2697 #ifdef ENABLE_CLASSIC
2698         case HCI_EVENT_ROLE_CHANGE:
2699             if (packet[2]) break;   // status != 0
2700             reverse_bd_addr(&packet[3], addr);
2701             addr_type = BD_ADDR_TYPE_ACL;
2702             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2703             if (!conn) break;
2704             conn->role = packet[9];
2705             break;
2706 #endif
2707 
2708         case HCI_EVENT_TRANSPORT_PACKET_SENT:
2709             // release packet buffer only for asynchronous transport and if there are not further fragements
2710             if (hci_transport_synchronous()) {
2711                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
2712                 return; // instead of break: to avoid re-entering hci_run()
2713             }
2714             hci_stack->acl_fragmentation_tx_active = 0;
2715             if (hci_stack->acl_fragmentation_total_size) break;
2716             hci_release_packet_buffer();
2717 
2718             // L2CAP receives this event via the hci_emit_event below
2719 
2720 #ifdef ENABLE_CLASSIC
2721             // For SCO, we do the can_send_now_check here
2722             hci_notify_if_sco_can_send_now();
2723 #endif
2724             break;
2725 
2726 #ifdef ENABLE_CLASSIC
2727         case HCI_EVENT_SCO_CAN_SEND_NOW:
2728             // For SCO, we do the can_send_now_check here
2729             hci_stack->sco_can_send_now = 1;
2730             hci_notify_if_sco_can_send_now();
2731             return;
2732 
2733         // explode inquriy results for easier consumption
2734         case HCI_EVENT_INQUIRY_RESULT:
2735         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
2736         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
2737             gap_inquiry_explode(packet, size);
2738             break;
2739 #endif
2740 
2741 #ifdef ENABLE_BLE
2742         case HCI_EVENT_LE_META:
2743             switch (packet[2]){
2744 #ifdef ENABLE_LE_CENTRAL
2745                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
2746                     // log_info("advertising report received");
2747                     if (!hci_stack->le_scanning_enabled) break;
2748                     le_handle_advertisement_report(packet, size);
2749                     break;
2750 #endif
2751                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
2752 					event_handle_le_connection_complete(packet);
2753                     break;
2754 
2755                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
2756                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
2757                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
2758                     conn = hci_connection_for_handle(handle);
2759                     if (!conn) break;
2760                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
2761                     break;
2762 
2763                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
2764                     // connection
2765                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
2766                     conn = hci_connection_for_handle(handle);
2767                     if (conn) {
2768                         // read arguments
2769                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
2770                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
2771                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
2772                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
2773 
2774                         // validate against current connection parameter range
2775                         le_connection_parameter_range_t existing_range;
2776                         gap_get_connection_parameter_range(&existing_range);
2777                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
2778                         if (update_parameter){
2779                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
2780                             conn->le_conn_interval_min = le_conn_interval_min;
2781                             conn->le_conn_interval_max = le_conn_interval_max;
2782                             conn->le_conn_latency = le_conn_latency;
2783                             conn->le_supervision_timeout = le_supervision_timeout;
2784                         } else {
2785                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NEGATIVE_REPLY;
2786                         }
2787                     }
2788                     break;
2789 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
2790                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
2791                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
2792                     conn = hci_connection_for_handle(handle);
2793                     if (conn) {
2794                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
2795                     }
2796                     break;
2797 #endif
2798                 default:
2799                     break;
2800             }
2801             break;
2802 #endif
2803         case HCI_EVENT_VENDOR_SPECIFIC:
2804             // Vendor specific commands often create vendor specific event instead of num completed packets
2805             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
2806             switch (hci_stack->manufacturer){
2807                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
2808                     hci_stack->num_cmd_packets = 1;
2809                     break;
2810                 default:
2811                     break;
2812             }
2813             break;
2814         default:
2815             break;
2816     }
2817 
2818     handle_event_for_current_stack_state(packet, size);
2819 
2820     // notify upper stack
2821 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
2822 
2823     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
2824     if ((hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE) && (packet[2] == 0)){
2825 		handle = little_endian_read_16(packet, 3);
2826 		hci_connection_t * aConn = hci_connection_for_handle(handle);
2827 		// discard connection if app did not trigger a reconnect in the event handler
2828 		if (aConn && aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
2829 			hci_shutdown_connection(aConn);
2830 		}
2831     }
2832 
2833 	// execute main loop
2834 	hci_run();
2835 }
2836 
2837 #ifdef ENABLE_CLASSIC
2838 
2839 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
2840 static void sco_schedule_tx(hci_connection_t * conn);
2841 
2842 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
2843     log_debug("SCO TX Timeout");
2844     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
2845     hci_connection_t * conn = hci_connection_for_handle(con_handle);
2846     if (!conn) return;
2847 
2848     // trigger send
2849     conn->sco_tx_ready = 1;
2850     // extra packet if CVSD but SCO buffer is too short
2851     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
2852         conn->sco_tx_ready++;
2853     }
2854     hci_notify_if_sco_can_send_now();
2855 }
2856 
2857 
2858 #define SCO_TX_AFTER_RX_MS (6)
2859 
2860 static void sco_schedule_tx(hci_connection_t * conn){
2861 
2862     uint32_t now = btstack_run_loop_get_time_ms();
2863     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
2864     int time_delta_ms = sco_tx_ms - now;
2865 
2866     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
2867 
2868     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
2869     btstack_run_loop_set_timer(timer, time_delta_ms);
2870     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
2871     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
2872     btstack_run_loop_add_timer(timer);
2873 }
2874 
2875 static void sco_handler(uint8_t * packet, uint16_t size){
2876     // lookup connection struct
2877     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
2878     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
2879     if (!conn) return;
2880 
2881     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
2882     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
2883         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
2884             packet[2] = 0x3c;
2885             memmove(&packet[3], &packet[23], 63);
2886             size = 63;
2887         }
2888     }
2889 
2890     if (hci_have_usb_transport()){
2891         // Nothing to do
2892     } else {
2893         // log_debug("sco flow %u, handle 0x%04x, packets sent %u, bytes send %u", hci_stack->synchronous_flow_control_enabled, (int) con_handle, conn->num_packets_sent, conn->num_sco_bytes_sent);
2894         if (hci_stack->synchronous_flow_control_enabled == 0){
2895             uint32_t now = btstack_run_loop_get_time_ms();
2896 
2897             if (!conn->sco_rx_valid){
2898                 // ignore first 10 packets
2899                 conn->sco_rx_count++;
2900                 // log_debug("sco rx count %u", conn->sco_rx_count);
2901                 if (conn->sco_rx_count == 10) {
2902                     // use first timestamp as is and pretent it just started
2903                     conn->sco_rx_ms = now;
2904                     conn->sco_rx_valid = 1;
2905                     conn->sco_rx_count = 0;
2906                     sco_schedule_tx(conn);
2907                 }
2908             } else {
2909                 // track expected arrival timme
2910                 conn->sco_rx_count++;
2911                 conn->sco_rx_ms += 7;
2912                 int delta = (int32_t) (now - conn->sco_rx_ms);
2913                 if (delta > 0){
2914                     conn->sco_rx_ms++;
2915                 }
2916                 // log_debug("sco rx %u", conn->sco_rx_ms);
2917                 sco_schedule_tx(conn);
2918             }
2919         }
2920     }
2921     // deliver to app
2922     if (hci_stack->sco_packet_handler) {
2923         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
2924     }
2925 
2926 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
2927     conn->num_packets_completed++;
2928     hci_stack->host_completed_packets = 1;
2929     hci_run();
2930 #endif
2931 }
2932 #endif
2933 
2934 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
2935     hci_dump_packet(packet_type, 1, packet, size);
2936     switch (packet_type) {
2937         case HCI_EVENT_PACKET:
2938             event_handler(packet, size);
2939             break;
2940         case HCI_ACL_DATA_PACKET:
2941             acl_handler(packet, size);
2942             break;
2943 #ifdef ENABLE_CLASSIC
2944         case HCI_SCO_DATA_PACKET:
2945             sco_handler(packet, size);
2946             break;
2947 #endif
2948         default:
2949             break;
2950     }
2951 }
2952 
2953 /**
2954  * @brief Add event packet handler.
2955  */
2956 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
2957     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
2958 }
2959 
2960 
2961 /** Register HCI packet handlers */
2962 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
2963     hci_stack->acl_packet_handler = handler;
2964 }
2965 
2966 #ifdef ENABLE_CLASSIC
2967 /**
2968  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
2969  */
2970 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
2971     hci_stack->sco_packet_handler = handler;
2972 }
2973 #endif
2974 
2975 static void hci_state_reset(void){
2976     // no connections yet
2977     hci_stack->connections = NULL;
2978 
2979     // keep discoverable/connectable as this has been requested by the client(s)
2980     // hci_stack->discoverable = 0;
2981     // hci_stack->connectable = 0;
2982     // hci_stack->bondable = 1;
2983     // hci_stack->own_addr_type = 0;
2984 
2985     // buffer is free
2986     hci_stack->hci_packet_buffer_reserved = 0;
2987 
2988     // no pending cmds
2989     hci_stack->decline_reason = 0;
2990     hci_stack->new_scan_enable_value = 0xff;
2991 
2992     hci_stack->secure_connections_active = false;
2993 
2994     // LE
2995 #ifdef ENABLE_BLE
2996     memset(hci_stack->le_random_address, 0, 6);
2997     hci_stack->le_random_address_set = 0;
2998 #endif
2999 #ifdef ENABLE_LE_CENTRAL
3000     hci_stack->le_scanning_active  = 0;
3001     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3002     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
3003     hci_stack->le_whitelist_capacity = 0;
3004 #endif
3005 }
3006 
3007 #ifdef ENABLE_CLASSIC
3008 /**
3009  * @brief Configure Bluetooth hardware control. Has to be called before power on.
3010  */
3011 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
3012     // store and open remote device db
3013     hci_stack->link_key_db = link_key_db;
3014     if (hci_stack->link_key_db) {
3015         hci_stack->link_key_db->open();
3016     }
3017 }
3018 #endif
3019 
3020 void hci_init(const hci_transport_t *transport, const void *config){
3021 
3022 #ifdef HAVE_MALLOC
3023     if (!hci_stack) {
3024         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
3025     }
3026 #else
3027     hci_stack = &hci_stack_static;
3028 #endif
3029     memset(hci_stack, 0, sizeof(hci_stack_t));
3030 
3031     // reference to use transport layer implementation
3032     hci_stack->hci_transport = transport;
3033 
3034     // reference to used config
3035     hci_stack->config = config;
3036 
3037     // setup pointer for outgoing packet buffer
3038     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3039 
3040     // max acl payload size defined in config.h
3041     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3042 
3043     // register packet handlers with transport
3044     transport->register_packet_handler(&packet_handler);
3045 
3046     hci_stack->state = HCI_STATE_OFF;
3047 
3048     // class of device
3049     hci_stack->class_of_device = 0x007a020c; // Smartphone
3050 
3051     // bondable by default
3052     hci_stack->bondable = 1;
3053 
3054 #ifdef ENABLE_CLASSIC
3055     // classic name
3056     hci_stack->local_name = default_classic_name;
3057 
3058     // Master slave policy
3059     hci_stack->master_slave_policy = 1;
3060 
3061     // Allow Role Switch
3062     hci_stack->allow_role_switch = 1;
3063 
3064     // Default / minimum security level = 2
3065     hci_stack->gap_security_level = LEVEL_2;
3066 
3067     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3068     hci_stack->gap_required_encyrption_key_size = 7;
3069 #endif
3070 
3071     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3072     hci_stack->ssp_enable = 1;
3073     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3074     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3075     hci_stack->ssp_auto_accept = 1;
3076 
3077     // Secure Connections: enable (requires support from Controller)
3078     hci_stack->secure_connections_enable = true;
3079 
3080     // voice setting - signed 16 bit pcm data with CVSD over the air
3081     hci_stack->sco_voice_setting = 0x60;
3082 
3083 #ifdef ENABLE_LE_CENTRAL
3084     // connection parameter to use for outgoing connections
3085     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3086     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3087     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3088     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3089     hci_stack->le_connection_latency      = 4;         // 4
3090     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3091     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3092     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3093 
3094     // default LE Scanning
3095     hci_stack->le_scan_type     =   0x1; // active
3096     hci_stack->le_scan_interval = 0x1e0; // 300 ms
3097     hci_stack->le_scan_window   =  0x30; //  30 ms
3098 #endif
3099 
3100 #ifdef ENABLE_LE_PERIPHERAL
3101     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3102 #endif
3103 
3104     // connection parameter range used to answer connection parameter update requests in l2cap
3105     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3106     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3107     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3108     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3109     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3110     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3111 
3112     hci_state_reset();
3113 }
3114 
3115 /**
3116  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3117  */
3118 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3119     hci_stack->chipset = chipset_driver;
3120 
3121     // reset chipset driver - init is also called on power_up
3122     if (hci_stack->chipset && hci_stack->chipset->init){
3123         hci_stack->chipset->init(hci_stack->config);
3124     }
3125 }
3126 
3127 /**
3128  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3129  */
3130 void hci_set_control(const btstack_control_t *hardware_control){
3131     // references to used control implementation
3132     hci_stack->control = hardware_control;
3133     // init with transport config
3134     hardware_control->init(hci_stack->config);
3135 }
3136 
3137 void hci_close(void){
3138     // close remote device db
3139     if (hci_stack->link_key_db) {
3140         hci_stack->link_key_db->close();
3141     }
3142 
3143     btstack_linked_list_iterator_t lit;
3144     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3145     while (btstack_linked_list_iterator_has_next(&lit)){
3146         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3147         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3148         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3149         hci_shutdown_connection(connection);
3150     }
3151 
3152     hci_power_control(HCI_POWER_OFF);
3153 
3154 #ifdef HAVE_MALLOC
3155     free(hci_stack);
3156 #endif
3157     hci_stack = NULL;
3158 }
3159 
3160 #ifdef ENABLE_CLASSIC
3161 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3162     // validate ranage and set
3163     if (encryption_key_size < 7)  return;
3164     if (encryption_key_size > 16) return;
3165     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3166 }
3167 
3168 void gap_set_security_level(gap_security_level_t security_level){
3169     hci_stack->gap_security_level = security_level;
3170 }
3171 
3172 gap_security_level_t gap_get_security_level(void){
3173     return hci_stack->gap_security_level;
3174 }
3175 #endif
3176 
3177 #ifdef ENABLE_CLASSIC
3178 void gap_set_class_of_device(uint32_t class_of_device){
3179     hci_stack->class_of_device = class_of_device;
3180 }
3181 
3182 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3183     hci_stack->default_link_policy_settings = default_link_policy_settings;
3184 }
3185 
3186 void gap_set_allow_role_switch(bool allow_role_switch){
3187     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3188 }
3189 
3190 uint8_t hci_get_allow_role_switch(void){
3191     return  hci_stack->allow_role_switch;
3192 }
3193 
3194 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3195     hci_stack->link_supervision_timeout = link_supervision_timeout;
3196 }
3197 
3198 void hci_disable_l2cap_timeout_check(void){
3199     disable_l2cap_timeouts = 1;
3200 }
3201 #endif
3202 
3203 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
3204 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3205 void hci_set_bd_addr(bd_addr_t addr){
3206     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3207     hci_stack->custom_bd_addr_set = 1;
3208 }
3209 #endif
3210 
3211 // State-Module-Driver overview
3212 // state                    module  low-level
3213 // HCI_STATE_OFF             off      close
3214 // HCI_STATE_INITIALIZING,   on       open
3215 // HCI_STATE_WORKING,        on       open
3216 // HCI_STATE_HALTING,        on       open
3217 // HCI_STATE_SLEEPING,    off/sleep   close
3218 // HCI_STATE_FALLING_ASLEEP  on       open
3219 
3220 static int hci_power_control_on(void){
3221 
3222     // power on
3223     int err = 0;
3224     if (hci_stack->control && hci_stack->control->on){
3225         err = (*hci_stack->control->on)();
3226     }
3227     if (err){
3228         log_error( "POWER_ON failed");
3229         hci_emit_hci_open_failed();
3230         return err;
3231     }
3232 
3233     // int chipset driver
3234     if (hci_stack->chipset && hci_stack->chipset->init){
3235         hci_stack->chipset->init(hci_stack->config);
3236     }
3237 
3238     // init transport
3239     if (hci_stack->hci_transport->init){
3240         hci_stack->hci_transport->init(hci_stack->config);
3241     }
3242 
3243     // open transport
3244     err = hci_stack->hci_transport->open();
3245     if (err){
3246         log_error( "HCI_INIT failed, turning Bluetooth off again");
3247         if (hci_stack->control && hci_stack->control->off){
3248             (*hci_stack->control->off)();
3249         }
3250         hci_emit_hci_open_failed();
3251         return err;
3252     }
3253     return 0;
3254 }
3255 
3256 static void hci_power_control_off(void){
3257 
3258     log_info("hci_power_control_off");
3259 
3260     // close low-level device
3261     hci_stack->hci_transport->close();
3262 
3263     log_info("hci_power_control_off - hci_transport closed");
3264 
3265     // power off
3266     if (hci_stack->control && hci_stack->control->off){
3267         (*hci_stack->control->off)();
3268     }
3269 
3270     log_info("hci_power_control_off - control closed");
3271 
3272     hci_stack->state = HCI_STATE_OFF;
3273 }
3274 
3275 static void hci_power_control_sleep(void){
3276 
3277     log_info("hci_power_control_sleep");
3278 
3279 #if 0
3280     // don't close serial port during sleep
3281 
3282     // close low-level device
3283     hci_stack->hci_transport->close(hci_stack->config);
3284 #endif
3285 
3286     // sleep mode
3287     if (hci_stack->control && hci_stack->control->sleep){
3288         (*hci_stack->control->sleep)();
3289     }
3290 
3291     hci_stack->state = HCI_STATE_SLEEPING;
3292 }
3293 
3294 static int hci_power_control_wake(void){
3295 
3296     log_info("hci_power_control_wake");
3297 
3298     // wake on
3299     if (hci_stack->control && hci_stack->control->wake){
3300         (*hci_stack->control->wake)();
3301     }
3302 
3303 #if 0
3304     // open low-level device
3305     int err = hci_stack->hci_transport->open(hci_stack->config);
3306     if (err){
3307         log_error( "HCI_INIT failed, turning Bluetooth off again");
3308         if (hci_stack->control && hci_stack->control->off){
3309             (*hci_stack->control->off)();
3310         }
3311         hci_emit_hci_open_failed();
3312         return err;
3313     }
3314 #endif
3315 
3316     return 0;
3317 }
3318 
3319 static void hci_power_transition_to_initializing(void){
3320     // set up state machine
3321     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3322     hci_stack->hci_packet_buffer_reserved = 0;
3323     hci_stack->state = HCI_STATE_INITIALIZING;
3324     hci_stack->substate = HCI_INIT_SEND_RESET;
3325 }
3326 
3327 int hci_power_control(HCI_POWER_MODE power_mode){
3328 
3329     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
3330 
3331     int err = 0;
3332     switch (hci_stack->state){
3333 
3334         case HCI_STATE_OFF:
3335             switch (power_mode){
3336                 case HCI_POWER_ON:
3337                     err = hci_power_control_on();
3338                     if (err) {
3339                         log_error("hci_power_control_on() error %d", err);
3340                         return err;
3341                     }
3342                     hci_power_transition_to_initializing();
3343                     break;
3344                 case HCI_POWER_OFF:
3345                     // do nothing
3346                     break;
3347                 case HCI_POWER_SLEEP:
3348                     // do nothing (with SLEEP == OFF)
3349                     break;
3350                 default:
3351                     btstack_assert(false);
3352                     break;
3353             }
3354             break;
3355 
3356         case HCI_STATE_INITIALIZING:
3357             switch (power_mode){
3358                 case HCI_POWER_ON:
3359                     // do nothing
3360                     break;
3361                 case HCI_POWER_OFF:
3362                     // no connections yet, just turn it off
3363                     hci_power_control_off();
3364                     break;
3365                 case HCI_POWER_SLEEP:
3366                     // no connections yet, just turn it off
3367                     hci_power_control_sleep();
3368                     break;
3369                 default:
3370                     btstack_assert(false);
3371                     break;
3372             }
3373             break;
3374 
3375         case HCI_STATE_WORKING:
3376             switch (power_mode){
3377                 case HCI_POWER_ON:
3378                     // do nothing
3379                     break;
3380                 case HCI_POWER_OFF:
3381                     // see hci_run
3382                     hci_stack->state = HCI_STATE_HALTING;
3383                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3384                     break;
3385                 case HCI_POWER_SLEEP:
3386                     // see hci_run
3387                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3388                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3389                     break;
3390                 default:
3391                     btstack_assert(false);
3392                     break;
3393             }
3394             break;
3395 
3396         case HCI_STATE_HALTING:
3397             switch (power_mode){
3398                 case HCI_POWER_ON:
3399                     hci_power_transition_to_initializing();
3400                     break;
3401                 case HCI_POWER_OFF:
3402                     // do nothing
3403                     break;
3404                 case HCI_POWER_SLEEP:
3405                     // see hci_run
3406                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3407                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3408                     break;
3409                 default:
3410                     btstack_assert(false);
3411                     break;
3412             }
3413             break;
3414 
3415         case HCI_STATE_FALLING_ASLEEP:
3416             switch (power_mode){
3417                 case HCI_POWER_ON:
3418 
3419 #ifdef HAVE_PLATFORM_IPHONE_OS
3420                     // nothing to do, if H4 supports power management
3421                     if (btstack_control_iphone_power_management_enabled()){
3422                         hci_stack->state = HCI_STATE_INITIALIZING;
3423                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
3424                         break;
3425                     }
3426 #endif
3427                     hci_power_transition_to_initializing();
3428                     break;
3429                 case HCI_POWER_OFF:
3430                     // see hci_run
3431                     hci_stack->state = HCI_STATE_HALTING;
3432                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3433                     break;
3434                 case HCI_POWER_SLEEP:
3435                     // do nothing
3436                     break;
3437                 default:
3438                     btstack_assert(false);
3439                     break;
3440             }
3441             break;
3442 
3443         case HCI_STATE_SLEEPING:
3444             switch (power_mode){
3445                 case HCI_POWER_ON:
3446 
3447 #ifdef HAVE_PLATFORM_IPHONE_OS
3448                     // nothing to do, if H4 supports power management
3449                     if (btstack_control_iphone_power_management_enabled()){
3450                         hci_stack->state = HCI_STATE_INITIALIZING;
3451                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
3452                         hci_update_scan_enable();
3453                         break;
3454                     }
3455 #endif
3456                     err = hci_power_control_wake();
3457                     if (err) return err;
3458                     hci_power_transition_to_initializing();
3459                     break;
3460                 case HCI_POWER_OFF:
3461                     hci_stack->state = HCI_STATE_HALTING;
3462                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3463                     break;
3464                 case HCI_POWER_SLEEP:
3465                     // do nothing
3466                     break;
3467                 default:
3468                     btstack_assert(false);
3469                     break;
3470             }
3471             break;
3472 
3473         default:
3474             btstack_assert(false);
3475             break;
3476     }
3477 
3478     // create internal event
3479 	hci_emit_state();
3480 
3481 	// trigger next/first action
3482 	hci_run();
3483 
3484     return 0;
3485 }
3486 
3487 
3488 #ifdef ENABLE_CLASSIC
3489 
3490 static void hci_update_scan_enable(void){
3491     // 2 = page scan, 1 = inq scan
3492     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
3493     hci_run();
3494 }
3495 
3496 void gap_discoverable_control(uint8_t enable){
3497     if (enable) enable = 1; // normalize argument
3498 
3499     if (hci_stack->discoverable == enable){
3500         hci_emit_discoverable_enabled(hci_stack->discoverable);
3501         return;
3502     }
3503 
3504     hci_stack->discoverable = enable;
3505     hci_update_scan_enable();
3506 }
3507 
3508 void gap_connectable_control(uint8_t enable){
3509     if (enable) enable = 1; // normalize argument
3510 
3511     // don't emit event
3512     if (hci_stack->connectable == enable) return;
3513 
3514     hci_stack->connectable = enable;
3515     hci_update_scan_enable();
3516 }
3517 #endif
3518 
3519 void gap_local_bd_addr(bd_addr_t address_buffer){
3520     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
3521 }
3522 
3523 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3524 static void hci_host_num_completed_packets(void){
3525 
3526     // create packet manually as arrays are not supported and num_commands should not get reduced
3527     hci_reserve_packet_buffer();
3528     uint8_t * packet = hci_get_outgoing_packet_buffer();
3529 
3530     uint16_t size = 0;
3531     uint16_t num_handles = 0;
3532     packet[size++] = 0x35;
3533     packet[size++] = 0x0c;
3534     size++;  // skip param len
3535     size++;  // skip num handles
3536 
3537     // add { handle, packets } entries
3538     btstack_linked_item_t * it;
3539     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3540         hci_connection_t * connection = (hci_connection_t *) it;
3541         if (connection->num_packets_completed){
3542             little_endian_store_16(packet, size, connection->con_handle);
3543             size += 2;
3544             little_endian_store_16(packet, size, connection->num_packets_completed);
3545             size += 2;
3546             //
3547             num_handles++;
3548             connection->num_packets_completed = 0;
3549         }
3550     }
3551 
3552     packet[2] = size - 3;
3553     packet[3] = num_handles;
3554 
3555     hci_stack->host_completed_packets = 0;
3556 
3557     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
3558     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
3559 
3560     // release packet buffer for synchronous transport implementations
3561     if (hci_transport_synchronous()){
3562         hci_release_packet_buffer();
3563         hci_emit_transport_packet_sent();
3564     }
3565 }
3566 #endif
3567 
3568 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
3569     UNUSED(ds);
3570     hci_stack->substate = HCI_HALTING_CLOSE;
3571     // allow packet handlers to defer final shutdown
3572     hci_emit_state();
3573     hci_run();
3574 }
3575 
3576 static bool hci_run_acl_fragments(void){
3577     if (hci_stack->acl_fragmentation_total_size > 0u) {
3578         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
3579         hci_connection_t *connection = hci_connection_for_handle(con_handle);
3580         if (connection) {
3581             if (hci_can_send_prepared_acl_packet_now(con_handle)){
3582                 hci_send_acl_packet_fragments(connection);
3583                 return true;
3584             }
3585         } else {
3586             // connection gone -> discard further fragments
3587             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
3588             hci_stack->acl_fragmentation_total_size = 0;
3589             hci_stack->acl_fragmentation_pos = 0;
3590         }
3591     }
3592     return false;
3593 }
3594 
3595 #ifdef ENABLE_CLASSIC
3596 static bool hci_run_general_gap_classic(void){
3597 
3598     // decline incoming connections
3599     if (hci_stack->decline_reason){
3600         uint8_t reason = hci_stack->decline_reason;
3601         hci_stack->decline_reason = 0;
3602         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
3603         return true;
3604     }
3605     // send scan enable
3606     if ((hci_stack->state == HCI_STATE_WORKING) && (hci_stack->new_scan_enable_value != 0xff) && hci_classic_supported()){
3607         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
3608         hci_stack->new_scan_enable_value = 0xff;
3609         return true;
3610     }
3611     // start/stop inquiry
3612     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
3613         uint8_t duration = hci_stack->inquiry_state;
3614         hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
3615         hci_send_cmd(&hci_inquiry, GAP_IAC_GENERAL_INQUIRY, duration, 0);
3616         return true;
3617     }
3618     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
3619         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
3620         hci_send_cmd(&hci_inquiry_cancel);
3621         return true;
3622     }
3623     // remote name request
3624     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
3625         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
3626         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
3627                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
3628         return true;
3629     }
3630     // pairing
3631     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
3632         uint8_t state = hci_stack->gap_pairing_state;
3633         hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
3634         switch (state){
3635             case GAP_PAIRING_STATE_SEND_PIN:
3636                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_pin_len, hci_stack->gap_pairing_input.gap_pairing_pin);
3637                 break;
3638             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
3639                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
3640                 break;
3641             case GAP_PAIRING_STATE_SEND_PASSKEY:
3642                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
3643                 break;
3644             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
3645                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
3646                 break;
3647             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
3648                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
3649                 break;
3650             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
3651                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
3652                 break;
3653             default:
3654                 break;
3655         }
3656         return true;
3657     }
3658     return false;
3659 }
3660 #endif
3661 
3662 #ifdef ENABLE_BLE
3663 static bool hci_run_general_gap_le(void){
3664 
3665     // advertisements, active scanning, and creating connections requires random address to be set if using private address
3666 
3667     if (hci_stack->state != HCI_STATE_WORKING) return false;
3668     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
3669 
3670 
3671     // Phase 1: collect what to stop
3672 
3673     bool scanning_stop = false;
3674     bool connecting_stop = false;
3675     bool advertising_stop = false;
3676 
3677 #ifndef ENABLE_LE_CENTRAL
3678     UNUSED(scanning_stop);
3679     UNUSED(connecting_stop);
3680 #endif
3681 #ifndef ENABLE_LE_PERIPHERAL
3682     UNUSED(advertising_stop);
3683 #endif
3684 
3685     // check if whitelist needs modification
3686     bool whitelist_modification_pending = false;
3687     btstack_linked_list_iterator_t lit;
3688     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3689     while (btstack_linked_list_iterator_has_next(&lit)){
3690         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3691         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
3692             whitelist_modification_pending = true;
3693             break;
3694         }
3695     }
3696     // check if resolving list needs modification
3697     bool resolving_list_modification_pending = false;
3698 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
3699     bool resolving_list_supported = (hci_stack->local_supported_commands[1] & (1 << 2)) != 0;
3700 	if (resolving_list_supported && hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_DONE){
3701         resolving_list_modification_pending = true;
3702     }
3703 #endif
3704 
3705 #ifdef ENABLE_LE_CENTRAL
3706     // scanning control
3707     if (hci_stack->le_scanning_active) {
3708         // stop if:
3709         // - parameter change required
3710         // - it's disabled
3711         // - whitelist change required but used for scanning
3712         // - resolving list modified
3713         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
3714         if ((hci_stack->le_scanning_param_update) ||
3715             !hci_stack->le_scanning_enabled ||
3716             scanning_uses_whitelist ||
3717             resolving_list_modification_pending){
3718 
3719             scanning_stop = true;
3720         }
3721     }
3722 #endif
3723 
3724 #ifdef ENABLE_LE_CENTRAL
3725     // connecting control
3726     if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
3727         // stop connecting if:
3728         // - connecting uses white and whitelist modification pending
3729         // - if it got disabled
3730         // - resolving list modified
3731         bool connecting_uses_whitelist = hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST;
3732         if ((connecting_uses_whitelist && whitelist_modification_pending) ||
3733             (hci_stack->le_connecting_request == LE_CONNECTING_IDLE) ||
3734             resolving_list_modification_pending) {
3735 
3736             connecting_stop = true;
3737         }
3738     }
3739 #endif
3740 
3741 #ifdef ENABLE_LE_PERIPHERAL
3742     // le advertisement control
3743     if (hci_stack->le_advertisements_active){
3744         // stop if:
3745         // - parameter change required
3746         // - it's disabled
3747         // - whitelist change required but used for advertisement filter policy
3748         // - resolving list modified
3749         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy > 0;
3750         if ((hci_stack->le_advertisements_todo != 0) ||
3751             !hci_stack->le_advertisements_enabled_for_current_roles ||
3752             (advertising_uses_whitelist & whitelist_modification_pending) ||
3753             resolving_list_modification_pending) {
3754 
3755             advertising_stop = true;
3756         }
3757     }
3758 #endif
3759 
3760 
3761     // Phase 2: stop everything that should be off during modifications
3762 
3763 #ifdef ENABLE_LE_CENTRAL
3764     if (scanning_stop){
3765         hci_stack->le_scanning_active = false;
3766         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
3767         return true;
3768     }
3769 #endif
3770 
3771 #ifdef ENABLE_LE_CENTRAL
3772     if (connecting_stop){
3773         if (hci_stack->le_connecting_state != LE_CONNECTING_CANCEL){
3774             hci_send_cmd(&hci_le_create_connection_cancel);
3775             return true;
3776         }
3777     }
3778 #endif
3779 
3780 #ifdef ENABLE_LE_PERIPHERAL
3781     if (advertising_stop){
3782         hci_stack->le_advertisements_active = false;
3783         hci_send_cmd(&hci_le_set_advertise_enable, 0);
3784         return true;
3785     }
3786 #endif
3787 
3788     // Phase 3: modify
3789 
3790 #ifdef ENABLE_LE_CENTRAL
3791     if (hci_stack->le_scanning_param_update){
3792         hci_stack->le_scanning_param_update = false;
3793         hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
3794                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
3795         return true;
3796     }
3797 #endif
3798 
3799 #ifdef ENABLE_LE_PERIPHERAL
3800     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
3801         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3802         hci_send_cmd(&hci_le_set_advertising_parameters,
3803                      hci_stack->le_advertisements_interval_min,
3804                      hci_stack->le_advertisements_interval_max,
3805                      hci_stack->le_advertisements_type,
3806                      hci_stack->le_own_addr_type,
3807                      hci_stack->le_advertisements_direct_address_type,
3808                      hci_stack->le_advertisements_direct_address,
3809                      hci_stack->le_advertisements_channel_map,
3810                      hci_stack->le_advertisements_filter_policy);
3811         return true;
3812     }
3813     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
3814         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3815         uint8_t adv_data_clean[31];
3816         memset(adv_data_clean, 0, sizeof(adv_data_clean));
3817         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
3818                      hci_stack->le_advertisements_data_len);
3819         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
3820         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
3821         return true;
3822     }
3823     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
3824         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
3825         uint8_t scan_data_clean[31];
3826         memset(scan_data_clean, 0, sizeof(scan_data_clean));
3827         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
3828                      hci_stack->le_scan_response_data_len);
3829         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
3830         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
3831         return true;
3832     }
3833 #endif
3834 
3835 
3836 #ifdef ENABLE_LE_CENTRAL
3837     // if connect with whitelist was active and is not cancelled yet, wait until next time
3838     if (hci_stack->le_connecting_state == LE_CONNECTING_CANCEL) return false;
3839 #endif
3840 
3841     // LE Whitelist Management
3842     if (whitelist_modification_pending){
3843         // add/remove entries
3844         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3845         while (btstack_linked_list_iterator_has_next(&lit)){
3846             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3847 			if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
3848 				entry->state &= ~LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3849 				hci_send_cmd(&hci_le_remove_device_from_white_list, entry->address_type, entry->address);
3850 				return true;
3851 			}
3852             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
3853 				entry->state &= ~LE_WHITELIST_ADD_TO_CONTROLLER;
3854                 entry->state |= LE_WHITELIST_ON_CONTROLLER;
3855                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
3856                 return true;
3857             }
3858             if ((entry->state & LE_WHITELIST_ON_CONTROLLER) == 0){
3859 				btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
3860 				btstack_memory_whitelist_entry_free(entry);
3861             }
3862         }
3863     }
3864 
3865 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
3866     // LE Resolving List Management
3867     if (resolving_list_supported) {
3868 		uint16_t i;
3869 		switch (hci_stack->le_resolving_list_state) {
3870 			case LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION:
3871 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
3872 				hci_send_cmd(&hci_le_set_address_resolution_enabled, 1);
3873 				return true;
3874 			case LE_RESOLVING_LIST_READ_SIZE:
3875 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_SEND_CLEAR;
3876 				hci_send_cmd(&hci_le_read_resolving_list_size);
3877 				return true;
3878 			case LE_RESOLVING_LIST_SEND_CLEAR:
3879 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
3880 				(void) memset(hci_stack->le_resolving_list_add_entries, 0xff,
3881 							  sizeof(hci_stack->le_resolving_list_add_entries));
3882 				(void) memset(hci_stack->le_resolving_list_remove_entries, 0,
3883 							  sizeof(hci_stack->le_resolving_list_remove_entries));
3884 				hci_send_cmd(&hci_le_clear_resolving_list);
3885 				return true;
3886 			case LE_RESOLVING_LIST_REMOVE_ENTRIES:
3887 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
3888 					uint8_t offset = i >> 3;
3889 					uint8_t mask = 1 << (i & 7);
3890 					if ((hci_stack->le_resolving_list_remove_entries[offset] & mask) == 0) continue;
3891 					hci_stack->le_resolving_list_remove_entries[offset] &= ~mask;
3892 					bd_addr_t peer_identity_addreses;
3893 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
3894 					sm_key_t peer_irk;
3895 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
3896 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
3897 
3898 #ifdef ENABLE_LE_WHITELIST_TOUCH_AFTER_RESOLVING_LIST_UPDATE
3899 					// trigger whitelist entry 'update' (work around for controller bug)
3900 					btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3901 					while (btstack_linked_list_iterator_has_next(&lit)) {
3902 						whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&lit);
3903 						if (entry->address_type != peer_identity_addr_type) continue;
3904 						if (memcmp(entry->address, peer_identity_addreses, 6) != 0) continue;
3905 						log_info("trigger whitelist update %s", bd_addr_to_str(peer_identity_addreses));
3906 						entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER;
3907 					}
3908 #endif
3909 
3910 					hci_send_cmd(&hci_le_remove_device_from_resolving_list, peer_identity_addr_type,
3911 								 peer_identity_addreses);
3912 					return true;
3913 				}
3914 
3915 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_ADD_ENTRIES;
3916 
3917 				/* fall through */
3918 
3919 			case LE_RESOLVING_LIST_ADD_ENTRIES:
3920 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
3921 					uint8_t offset = i >> 3;
3922 					uint8_t mask = 1 << (i & 7);
3923 					if ((hci_stack->le_resolving_list_add_entries[offset] & mask) == 0) continue;
3924 					hci_stack->le_resolving_list_add_entries[offset] &= ~mask;
3925 					bd_addr_t peer_identity_addreses;
3926 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
3927 					sm_key_t peer_irk;
3928 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
3929 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
3930 					const uint8_t *local_irk = gap_get_persistent_irk();
3931 					// command uses format specifier 'P' that stores 16-byte value without flip
3932 					uint8_t local_irk_flipped[16];
3933 					uint8_t peer_irk_flipped[16];
3934 					reverse_128(local_irk, local_irk_flipped);
3935 					reverse_128(peer_irk, peer_irk_flipped);
3936 					hci_send_cmd(&hci_le_add_device_to_resolving_list, peer_identity_addr_type, peer_identity_addreses,
3937 								 peer_irk_flipped, local_irk_flipped);
3938 					return true;
3939 				}
3940 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
3941 				break;
3942 
3943 			default:
3944 				break;
3945 		}
3946 	}
3947     hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
3948 #endif
3949 
3950     // Phase 4: restore state
3951 
3952 #ifdef ENABLE_LE_CENTRAL
3953     // re-start scanning
3954     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
3955         hci_stack->le_scanning_active = true;
3956         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
3957         return true;
3958     }
3959 #endif
3960 
3961 #ifdef ENABLE_LE_CENTRAL
3962     // re-start connecting
3963     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
3964         bd_addr_t null_addr;
3965         memset(null_addr, 0, 6);
3966         hci_send_cmd(&hci_le_create_connection,
3967                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
3968                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
3969                      1,         // use whitelist
3970                      0,         // peer address type
3971                      null_addr, // peer bd addr
3972                      hci_stack->le_own_addr_type, // our addr type:
3973                      hci_stack->le_connection_interval_min,    // conn interval min
3974                      hci_stack->le_connection_interval_max,    // conn interval max
3975                      hci_stack->le_connection_latency,         // conn latency
3976                      hci_stack->le_supervision_timeout,        // conn latency
3977                      hci_stack->le_minimum_ce_length,          // min ce length
3978                      hci_stack->le_maximum_ce_length           // max ce length
3979         );
3980         return true;
3981     }
3982 #endif
3983 
3984 #ifdef ENABLE_LE_PERIPHERAL
3985     // re-start advertising
3986     if (hci_stack->le_advertisements_enabled_for_current_roles && !hci_stack->le_advertisements_active){
3987         // check if advertisements should be enabled given
3988         hci_stack->le_advertisements_active = true;
3989         hci_send_cmd(&hci_le_set_advertise_enable, 1);
3990         return true;
3991     }
3992 #endif
3993 
3994     return false;
3995 }
3996 #endif
3997 
3998 static bool hci_run_general_pending_commands(void){
3999     btstack_linked_item_t * it;
4000     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4001         hci_connection_t * connection = (hci_connection_t *) it;
4002 
4003         switch(connection->state){
4004             case SEND_CREATE_CONNECTION:
4005                 switch(connection->address_type){
4006 #ifdef ENABLE_CLASSIC
4007                     case BD_ADDR_TYPE_ACL:
4008                         log_info("sending hci_create_connection");
4009                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
4010                         break;
4011 #endif
4012                     default:
4013 #ifdef ENABLE_BLE
4014 #ifdef ENABLE_LE_CENTRAL
4015                         log_info("sending hci_le_create_connection");
4016                         hci_send_cmd(&hci_le_create_connection,
4017                                      hci_stack->le_connection_scan_interval,    // conn scan interval
4018                                      hci_stack->le_connection_scan_window,      // conn scan windows
4019                                      0,         // don't use whitelist
4020                                      connection->address_type, // peer address type
4021                                      connection->address,      // peer bd addr
4022                                      hci_stack->le_own_addr_type, // our addr type:
4023                                      hci_stack->le_connection_interval_min,    // conn interval min
4024                                      hci_stack->le_connection_interval_max,    // conn interval max
4025                                      hci_stack->le_connection_latency,         // conn latency
4026                                      hci_stack->le_supervision_timeout,        // conn latency
4027                                      hci_stack->le_minimum_ce_length,          // min ce length
4028                                      hci_stack->le_maximum_ce_length          // max ce length
4029                         );
4030                         connection->state = SENT_CREATE_CONNECTION;
4031 #endif
4032 #endif
4033                         break;
4034                 }
4035                 return true;
4036 
4037 #ifdef ENABLE_CLASSIC
4038             case RECEIVED_CONNECTION_REQUEST:
4039                 connection->role  = HCI_ROLE_SLAVE;
4040                 if (connection->address_type == BD_ADDR_TYPE_ACL){
4041                     log_info("sending hci_accept_connection_request");
4042                     connection->state = ACCEPTED_CONNECTION_REQUEST;
4043                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
4044                 }
4045                 return true;
4046 #endif
4047 
4048 #ifdef ENABLE_BLE
4049 #ifdef ENABLE_LE_CENTRAL
4050             case SEND_CANCEL_CONNECTION:
4051                 connection->state = SENT_CANCEL_CONNECTION;
4052                 hci_send_cmd(&hci_le_create_connection_cancel);
4053                 return true;
4054 #endif
4055 #endif
4056             case SEND_DISCONNECT:
4057                 connection->state = SENT_DISCONNECT;
4058                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4059                 return true;
4060 
4061             default:
4062                 break;
4063         }
4064 
4065         // no further commands if connection is about to get shut down
4066         if (connection->state == SENT_DISCONNECT) continue;
4067 
4068         if (connection->authentication_flags & READ_RSSI){
4069             connectionClearAuthenticationFlags(connection, READ_RSSI);
4070             hci_send_cmd(&hci_read_rssi, connection->con_handle);
4071             return true;
4072         }
4073 
4074 #ifdef ENABLE_CLASSIC
4075 
4076         if (connection->authentication_flags & WRITE_SUPERVISION_TIMEOUT){
4077             connectionClearAuthenticationFlags(connection, WRITE_SUPERVISION_TIMEOUT);
4078             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
4079             return true;
4080         }
4081 
4082         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
4083             log_info("responding to link key request");
4084             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
4085 
4086             link_key_t link_key;
4087             link_key_type_t link_key_type;
4088             bool have_link_key = hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type);
4089 
4090             const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
4091             bool sc_enabled_remote = (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
4092             bool sc_downgrade = have_link_key && (gap_secure_connection_for_link_key_type(link_key_type) == 1) && !sc_enabled_remote;
4093             if (sc_downgrade){
4094                 log_info("Link key based on SC, but remote does not support SC -> disconnect");
4095                 connection->state = SENT_DISCONNECT;
4096                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4097                 return true;
4098             }
4099 
4100             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level);
4101             if (have_link_key && security_level_sufficient){
4102                 connection->link_key_type = link_key_type;
4103                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
4104             } else {
4105                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
4106             }
4107             return true;
4108         }
4109 
4110         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
4111             log_info("denying to pin request");
4112             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
4113             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
4114             return true;
4115         }
4116 
4117         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
4118             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
4119             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
4120             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
4121                 // tweak authentication requirements
4122                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
4123                 if (connection->bonding_flags & BONDING_DEDICATED){
4124                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4125                 }
4126                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
4127                     authreq |= 1;
4128                 }
4129                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
4130             } else {
4131                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
4132             }
4133             return true;
4134         }
4135 
4136         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
4137             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
4138             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
4139             return true;
4140         }
4141 
4142         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
4143             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
4144             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
4145             return true;
4146         }
4147 
4148         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
4149             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
4150             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
4151             return true;
4152         }
4153 
4154         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
4155             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
4156             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
4157             return true;
4158         }
4159 
4160         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
4161             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
4162             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
4163             return true;
4164         }
4165 
4166         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
4167             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
4168             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
4169             connection->state = SENT_DISCONNECT;
4170             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4171             return true;
4172         }
4173 
4174         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
4175             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
4176             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
4177             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
4178             return true;
4179         }
4180 
4181         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
4182             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
4183             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
4184             return true;
4185         }
4186         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
4187             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
4188             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
4189             return true;
4190         }
4191 #endif
4192 
4193         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
4194             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
4195             if (connection->state != SENT_DISCONNECT){
4196                 connection->state = SENT_DISCONNECT;
4197                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4198                 return true;
4199             }
4200         }
4201 
4202 #ifdef ENABLE_CLASSIC
4203         uint16_t sniff_min_interval;
4204         switch (connection->sniff_min_interval){
4205             case 0:
4206                 break;
4207             case 0xffff:
4208                 connection->sniff_min_interval = 0;
4209                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
4210                 return true;
4211             default:
4212                 sniff_min_interval = connection->sniff_min_interval;
4213                 connection->sniff_min_interval = 0;
4214                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
4215                 return true;
4216         }
4217 
4218         if (connection->request_role != HCI_ROLE_INVALID){
4219             hci_role_t  role = connection->request_role;
4220             connection->request_role = HCI_ROLE_INVALID;
4221             hci_send_cmd(&hci_switch_role_command, connection->address, role);
4222             return true;
4223         }
4224 #endif
4225 
4226 #ifdef ENABLE_BLE
4227         switch (connection->le_con_parameter_update_state){
4228             // response to L2CAP CON PARAMETER UPDATE REQUEST
4229             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
4230                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4231                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
4232                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4233                              0x0000, 0xffff);
4234                 return true;
4235             case CON_PARAMETER_UPDATE_REPLY:
4236                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4237                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
4238                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4239                              0x0000, 0xffff);
4240                 return true;
4241             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
4242                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4243                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
4244                 return true;
4245             default:
4246                 break;
4247         }
4248         if (connection->le_phy_update_all_phys != 0xffu){
4249             uint8_t all_phys = connection->le_phy_update_all_phys;
4250             connection->le_phy_update_all_phys = 0xff;
4251             hci_send_cmd(&hci_le_set_phy, connection->con_handle, all_phys, connection->le_phy_update_tx_phys, connection->le_phy_update_rx_phys, connection->le_phy_update_phy_options);
4252             return true;
4253         }
4254 #endif
4255     }
4256     return false;
4257 }
4258 
4259 static void hci_run(void){
4260 
4261     bool done;
4262 
4263     // send continuation fragments first, as they block the prepared packet buffer
4264     done = hci_run_acl_fragments();
4265     if (done) return;
4266 
4267 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4268     // send host num completed packets next as they don't require num_cmd_packets > 0
4269     if (!hci_can_send_comand_packet_transport()) return;
4270     if (hci_stack->host_completed_packets){
4271         hci_host_num_completed_packets();
4272         return;
4273     }
4274 #endif
4275 
4276     if (!hci_can_send_command_packet_now()) return;
4277 
4278     // global/non-connection oriented commands
4279 
4280 
4281 #ifdef ENABLE_CLASSIC
4282     // general gap classic
4283     done = hci_run_general_gap_classic();
4284     if (done) return;
4285 #endif
4286 
4287 #ifdef ENABLE_BLE
4288     // general gap le
4289     done = hci_run_general_gap_le();
4290     if (done) return;
4291 #endif
4292 
4293     // send pending HCI commands
4294     done = hci_run_general_pending_commands();
4295     if (done) return;
4296 
4297     // stack state sub statemachines
4298     hci_connection_t * connection;
4299     switch (hci_stack->state){
4300         case HCI_STATE_INITIALIZING:
4301             hci_initializing_run();
4302             break;
4303 
4304         case HCI_STATE_HALTING:
4305 
4306             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4307             switch (hci_stack->substate){
4308                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4309                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
4310 
4311 #ifdef ENABLE_BLE
4312 #ifdef ENABLE_LE_CENTRAL
4313                     // free whitelist entries
4314                     {
4315                         btstack_linked_list_iterator_t lit;
4316                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4317                         while (btstack_linked_list_iterator_has_next(&lit)){
4318                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4319                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4320                             btstack_memory_whitelist_entry_free(entry);
4321                         }
4322                     }
4323 #endif
4324 #endif
4325                     // close all open connections
4326                     connection =  (hci_connection_t *) hci_stack->connections;
4327                     if (connection){
4328                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
4329                         if (!hci_can_send_command_packet_now()) return;
4330 
4331                         // check state
4332                         if (connection->state == SENT_DISCONNECT) return;
4333                         connection->state = SENT_DISCONNECT;
4334 
4335                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
4336 
4337                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
4338                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
4339 
4340                         // ... which would be ignored anyway as we shutdown (free) the connection now
4341                         hci_shutdown_connection(connection);
4342 
4343                         // finally, send the disconnect command
4344                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4345                         return;
4346                     }
4347 
4348                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
4349                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
4350                         log_info("HCI_STATE_HALTING: wait 50 ms");
4351                         hci_stack->substate = HCI_HALTING_W4_TIMER;
4352                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
4353                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
4354                         btstack_run_loop_add_timer(&hci_stack->timeout);
4355                         break;
4356                     }
4357 
4358                     /* fall through */
4359 
4360                 case HCI_HALTING_CLOSE:
4361                     log_info("HCI_STATE_HALTING, calling off");
4362 
4363                     // switch mode
4364                     hci_power_control_off();
4365 
4366                     log_info("HCI_STATE_HALTING, emitting state");
4367                     hci_emit_state();
4368                     log_info("HCI_STATE_HALTING, done");
4369                     break;
4370 
4371                 case HCI_HALTING_W4_TIMER:
4372                     // keep waiting
4373 
4374                     break;
4375                 default:
4376                     break;
4377             }
4378 
4379             break;
4380 
4381         case HCI_STATE_FALLING_ASLEEP:
4382             switch(hci_stack->substate) {
4383                 case HCI_FALLING_ASLEEP_DISCONNECT:
4384                     log_info("HCI_STATE_FALLING_ASLEEP");
4385                     // close all open connections
4386                     connection =  (hci_connection_t *) hci_stack->connections;
4387 
4388 #ifdef HAVE_PLATFORM_IPHONE_OS
4389                     // don't close connections, if H4 supports power management
4390                     if (btstack_control_iphone_power_management_enabled()){
4391                         connection = NULL;
4392                     }
4393 #endif
4394                     if (connection){
4395 
4396                         // send disconnect
4397                         if (!hci_can_send_command_packet_now()) return;
4398 
4399                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
4400                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4401 
4402                         // send disconnected event right away - causes higher layer connections to get closed, too.
4403                         hci_shutdown_connection(connection);
4404                         return;
4405                     }
4406 
4407                     if (hci_classic_supported()){
4408                         // disable page and inquiry scan
4409                         if (!hci_can_send_command_packet_now()) return;
4410 
4411                         log_info("HCI_STATE_HALTING, disabling inq scans");
4412                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
4413 
4414                         // continue in next sub state
4415                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
4416                         break;
4417                     }
4418 
4419                     /* fall through */
4420 
4421                 case HCI_FALLING_ASLEEP_COMPLETE:
4422                     log_info("HCI_STATE_HALTING, calling sleep");
4423 #ifdef HAVE_PLATFORM_IPHONE_OS
4424                     // don't actually go to sleep, if H4 supports power management
4425                     if (btstack_control_iphone_power_management_enabled()){
4426                         // SLEEP MODE reached
4427                         hci_stack->state = HCI_STATE_SLEEPING;
4428                         hci_emit_state();
4429                         break;
4430                     }
4431 #endif
4432                     // switch mode
4433                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
4434                     hci_emit_state();
4435                     break;
4436 
4437                 default:
4438                     break;
4439             }
4440             break;
4441 
4442         default:
4443             break;
4444     }
4445 }
4446 
4447 int hci_send_cmd_packet(uint8_t *packet, int size){
4448     // house-keeping
4449 
4450 #ifdef ENABLE_CLASSIC
4451     bd_addr_t addr;
4452     hci_connection_t * conn;
4453 #endif
4454 #ifdef ENABLE_LE_CENTRAL
4455     uint8_t initiator_filter_policy;
4456 #endif
4457 
4458     uint16_t opcode = little_endian_read_16(packet, 0);
4459     switch (opcode) {
4460         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
4461             hci_stack->loopback_mode = packet[3];
4462             break;
4463 
4464 #ifdef ENABLE_CLASSIC
4465         case HCI_OPCODE_HCI_CREATE_CONNECTION:
4466             reverse_bd_addr(&packet[3], addr);
4467             log_info("Create_connection to %s", bd_addr_to_str(addr));
4468 
4469             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4470             if (!conn) {
4471                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4472                 if (!conn) {
4473                     // notify client that alloc failed
4474                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4475                     return -1; // packet not sent to controller
4476                 }
4477                 conn->state = SEND_CREATE_CONNECTION;
4478                 conn->role  = HCI_ROLE_MASTER;
4479             }
4480             log_info("conn state %u", conn->state);
4481             switch (conn->state) {
4482                 // if connection active exists
4483                 case OPEN:
4484                     // and OPEN, emit connection complete command
4485                     hci_emit_connection_complete(addr, conn->con_handle, 0);
4486                     return -1; // packet not sent to controller
4487                 case RECEIVED_DISCONNECTION_COMPLETE:
4488                     // create connection triggered in disconnect complete event, let's do it now
4489                     break;
4490                 case SEND_CREATE_CONNECTION:
4491                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
4492                     break;
4493                 default:
4494                     // otherwise, just ignore as it is already in the open process
4495                     return -1; // packet not sent to controller
4496             }
4497             conn->state = SENT_CREATE_CONNECTION;
4498 
4499             // track outgoing connection
4500             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
4501             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
4502             break;
4503         case HCI_OPCODE_HCI_LINK_KEY_REQUEST_REPLY:
4504             hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
4505             break;
4506         case HCI_OPCODE_HCI_LINK_KEY_REQUEST_NEGATIVE_REPLY:
4507             hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
4508             break;
4509         case HCI_OPCODE_HCI_DELETE_STORED_LINK_KEY:
4510             if (hci_stack->link_key_db) {
4511                 reverse_bd_addr(&packet[3], addr);
4512                 hci_stack->link_key_db->delete_link_key(addr);
4513             }
4514             break;
4515         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
4516         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_REPLY:
4517             reverse_bd_addr(&packet[3], addr);
4518             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4519             if (conn) {
4520                 connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
4521             }
4522             break;
4523         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
4524         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_REPLY:
4525         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
4526         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_REPLY:
4527             reverse_bd_addr(&packet[3], addr);
4528             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4529             if (conn) {
4530                 connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
4531             }
4532             break;
4533 
4534 #ifdef ENABLE_SCO_OVER_HCI
4535         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
4536             // setup_synchronous_connection? Voice setting at offset 22
4537             // TODO: compare to current setting if sco connection already active
4538             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
4539             break;
4540         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
4541             // accept_synchronus_connection? Voice setting at offset 18
4542             // TODO: compare to current setting if sco connection already active
4543             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
4544             break;
4545 #endif
4546 #endif
4547 
4548 #ifdef ENABLE_BLE
4549         case HCI_OPCODE_HCI_LE_SET_RANDOM_ADDRESS:
4550             hci_stack->le_random_address_set = 1;
4551             reverse_bd_addr(&packet[3], hci_stack->le_random_address);
4552             break;
4553 #ifdef ENABLE_LE_PERIPHERAL
4554         case HCI_OPCODE_HCI_LE_SET_ADVERTISE_ENABLE:
4555             hci_stack->le_advertisements_active = packet[3] != 0;
4556             break;
4557 #endif
4558 #ifdef ENABLE_LE_CENTRAL
4559         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
4560             // white list used?
4561             initiator_filter_policy = packet[7];
4562             switch (initiator_filter_policy) {
4563                 case 0:
4564                     // whitelist not used
4565                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
4566                     break;
4567                 case 1:
4568                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
4569                     break;
4570                 default:
4571                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
4572                     break;
4573             }
4574             // track outgoing connection
4575             hci_stack->outgoing_addr_type = (bd_addr_type_t) packet[8]; // peer addres type
4576             reverse_bd_addr( &packet[9], hci_stack->outgoing_addr); // peer address
4577             break;
4578         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
4579             hci_stack->le_connecting_state = LE_CONNECTING_CANCEL;
4580             break;
4581 #endif
4582 #endif
4583         default:
4584             break;
4585     }
4586 
4587     hci_stack->num_cmd_packets--;
4588 
4589     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4590     return hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4591 }
4592 
4593 // disconnect because of security block
4594 void hci_disconnect_security_block(hci_con_handle_t con_handle){
4595     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4596     if (!connection) return;
4597     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
4598 }
4599 
4600 
4601 // Configure Secure Simple Pairing
4602 
4603 #ifdef ENABLE_CLASSIC
4604 
4605 // enable will enable SSP during init
4606 void gap_ssp_set_enable(int enable){
4607     hci_stack->ssp_enable = enable;
4608 }
4609 
4610 static int hci_local_ssp_activated(void){
4611     return gap_ssp_supported() && hci_stack->ssp_enable;
4612 }
4613 
4614 // if set, BTstack will respond to io capability request using authentication requirement
4615 void gap_ssp_set_io_capability(int io_capability){
4616     hci_stack->ssp_io_capability = io_capability;
4617 }
4618 void gap_ssp_set_authentication_requirement(int authentication_requirement){
4619     hci_stack->ssp_authentication_requirement = authentication_requirement;
4620 }
4621 
4622 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
4623 void gap_ssp_set_auto_accept(int auto_accept){
4624     hci_stack->ssp_auto_accept = auto_accept;
4625 }
4626 
4627 void gap_secure_connections_enable(bool enable){
4628     hci_stack->secure_connections_enable = enable;
4629 }
4630 
4631 #endif
4632 
4633 // va_list part of hci_send_cmd
4634 int hci_send_cmd_va_arg(const hci_cmd_t *cmd, va_list argptr){
4635     if (!hci_can_send_command_packet_now()){
4636         log_error("hci_send_cmd called but cannot send packet now");
4637         return 0;
4638     }
4639 
4640     // for HCI INITIALIZATION
4641     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
4642     hci_stack->last_cmd_opcode = cmd->opcode;
4643 
4644     hci_reserve_packet_buffer();
4645     uint8_t * packet = hci_stack->hci_packet_buffer;
4646     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
4647     int err = hci_send_cmd_packet(packet, size);
4648 
4649     // release packet buffer on error or for synchronous transport implementations
4650     if ((err < 0) || hci_transport_synchronous()){
4651         hci_release_packet_buffer();
4652         hci_emit_transport_packet_sent();
4653     }
4654 
4655     return err;
4656 }
4657 
4658 /**
4659  * pre: numcmds >= 0 - it's allowed to send a command to the controller
4660  */
4661 int hci_send_cmd(const hci_cmd_t *cmd, ...){
4662     va_list argptr;
4663     va_start(argptr, cmd);
4664     int res = hci_send_cmd_va_arg(cmd, argptr);
4665     va_end(argptr);
4666     return res;
4667 }
4668 
4669 // Create various non-HCI events.
4670 // TODO: generalize, use table similar to hci_create_command
4671 
4672 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
4673     // dump packet
4674     if (dump) {
4675         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
4676     }
4677 
4678     // dispatch to all event handlers
4679     btstack_linked_list_iterator_t it;
4680     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
4681     while (btstack_linked_list_iterator_has_next(&it)){
4682         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
4683         entry->callback(HCI_EVENT_PACKET, 0, event, size);
4684     }
4685 }
4686 
4687 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
4688     if (!hci_stack->acl_packet_handler) return;
4689     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
4690 }
4691 
4692 #ifdef ENABLE_CLASSIC
4693 static void hci_notify_if_sco_can_send_now(void){
4694     // notify SCO sender if waiting
4695     if (!hci_stack->sco_waiting_for_can_send_now) return;
4696     if (hci_can_send_sco_packet_now()){
4697         hci_stack->sco_waiting_for_can_send_now = 0;
4698         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
4699         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
4700         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
4701     }
4702 }
4703 
4704 // parsing end emitting has been merged to reduce code size
4705 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
4706     uint8_t event[19+GAP_INQUIRY_MAX_NAME_LEN];
4707 
4708     uint8_t * eir_data;
4709     ad_context_t context;
4710     const uint8_t * name;
4711     uint8_t         name_len;
4712 
4713     if (size < 3) return;
4714 
4715     int event_type = hci_event_packet_get_type(packet);
4716     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
4717     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
4718 
4719     switch (event_type){
4720         case HCI_EVENT_INQUIRY_RESULT:
4721         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4722             if (size != (3 + (num_responses * 14))) return;
4723             break;
4724         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4725             if (size != 257) return;
4726             if (num_responses != 1) return;
4727             break;
4728         default:
4729             return;
4730     }
4731 
4732     // event[1] is set at the end
4733     int i;
4734     for (i=0; i<num_responses;i++){
4735         memset(event, 0, sizeof(event));
4736         event[0] = GAP_EVENT_INQUIRY_RESULT;
4737         uint8_t event_size = 18;    // if name is not set by EIR
4738 
4739         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
4740         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
4741         (void)memcpy(&event[9],
4742                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
4743                      3); // class of device
4744         (void)memcpy(&event[12],
4745                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
4746                      2); // clock offset
4747 
4748         switch (event_type){
4749             case HCI_EVENT_INQUIRY_RESULT:
4750                 // 14,15,16,17 = 0, size 18
4751                 break;
4752             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4753                 event[14] = 1;
4754                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4755                 // 16,17 = 0, size 18
4756                 break;
4757             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4758                 event[14] = 1;
4759                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4760                 // EIR packets only contain a single inquiry response
4761                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
4762                 name = NULL;
4763                 // Iterate over EIR data
4764                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
4765                     uint8_t data_type    = ad_iterator_get_data_type(&context);
4766                     uint8_t data_size    = ad_iterator_get_data_len(&context);
4767                     const uint8_t * data = ad_iterator_get_data(&context);
4768                     // Prefer Complete Local Name over Shortend Local Name
4769                     switch (data_type){
4770                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
4771                             if (name) continue;
4772                             /* fall through */
4773                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
4774                             name = data;
4775                             name_len = data_size;
4776                             break;
4777                         default:
4778                             break;
4779                     }
4780                 }
4781                 if (name){
4782                     event[16] = 1;
4783                     // truncate name if needed
4784                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
4785                     event[17] = len;
4786                     (void)memcpy(&event[18], name, len);
4787                     event_size += len;
4788                 }
4789                 break;
4790             default:
4791                 return;
4792         }
4793         event[1] = event_size - 2;
4794         hci_emit_event(event, event_size, 1);
4795     }
4796 }
4797 #endif
4798 
4799 void hci_emit_state(void){
4800     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
4801     uint8_t event[3];
4802     event[0] = BTSTACK_EVENT_STATE;
4803     event[1] = sizeof(event) - 2u;
4804     event[2] = hci_stack->state;
4805     hci_emit_event(event, sizeof(event), 1);
4806 }
4807 
4808 #ifdef ENABLE_CLASSIC
4809 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4810     uint8_t event[13];
4811     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
4812     event[1] = sizeof(event) - 2;
4813     event[2] = status;
4814     little_endian_store_16(event, 3, con_handle);
4815     reverse_bd_addr(address, &event[5]);
4816     event[11] = 1; // ACL connection
4817     event[12] = 0; // encryption disabled
4818     hci_emit_event(event, sizeof(event), 1);
4819 }
4820 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
4821     if (disable_l2cap_timeouts) return;
4822     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
4823     uint8_t event[4];
4824     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
4825     event[1] = sizeof(event) - 2;
4826     little_endian_store_16(event, 2, conn->con_handle);
4827     hci_emit_event(event, sizeof(event), 1);
4828 }
4829 #endif
4830 
4831 #ifdef ENABLE_BLE
4832 #ifdef ENABLE_LE_CENTRAL
4833 static void hci_emit_le_connection_complete(uint8_t address_type, const bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4834     uint8_t event[21];
4835     event[0] = HCI_EVENT_LE_META;
4836     event[1] = sizeof(event) - 2u;
4837     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
4838     event[3] = status;
4839     little_endian_store_16(event, 4, con_handle);
4840     event[6] = 0; // TODO: role
4841     event[7] = address_type;
4842     reverse_bd_addr(address, &event[8]);
4843     little_endian_store_16(event, 14, 0); // interval
4844     little_endian_store_16(event, 16, 0); // latency
4845     little_endian_store_16(event, 18, 0); // supervision timeout
4846     event[20] = 0; // master clock accuracy
4847     hci_emit_event(event, sizeof(event), 1);
4848 }
4849 #endif
4850 #endif
4851 
4852 static void hci_emit_transport_packet_sent(void){
4853     // notify upper stack that it might be possible to send again
4854     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
4855     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
4856 }
4857 
4858 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
4859     uint8_t event[6];
4860     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
4861     event[1] = sizeof(event) - 2u;
4862     event[2] = 0; // status = OK
4863     little_endian_store_16(event, 3, con_handle);
4864     event[5] = reason;
4865     hci_emit_event(event, sizeof(event), 1);
4866 }
4867 
4868 static void hci_emit_nr_connections_changed(void){
4869     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
4870     uint8_t event[3];
4871     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
4872     event[1] = sizeof(event) - 2u;
4873     event[2] = nr_hci_connections();
4874     hci_emit_event(event, sizeof(event), 1);
4875 }
4876 
4877 static void hci_emit_hci_open_failed(void){
4878     log_info("BTSTACK_EVENT_POWERON_FAILED");
4879     uint8_t event[2];
4880     event[0] = BTSTACK_EVENT_POWERON_FAILED;
4881     event[1] = sizeof(event) - 2u;
4882     hci_emit_event(event, sizeof(event), 1);
4883 }
4884 
4885 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
4886     log_info("hci_emit_dedicated_bonding_result %u ", status);
4887     uint8_t event[9];
4888     int pos = 0;
4889     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
4890     event[pos++] = sizeof(event) - 2u;
4891     event[pos++] = status;
4892     reverse_bd_addr(address, &event[pos]);
4893     hci_emit_event(event, sizeof(event), 1);
4894 }
4895 
4896 
4897 #ifdef ENABLE_CLASSIC
4898 
4899 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
4900     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
4901     uint8_t event[5];
4902     int pos = 0;
4903     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
4904     event[pos++] = sizeof(event) - 2;
4905     little_endian_store_16(event, 2, con_handle);
4906     pos += 2;
4907     event[pos++] = level;
4908     hci_emit_event(event, sizeof(event), 1);
4909 }
4910 
4911 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
4912     if (!connection) return LEVEL_0;
4913     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
4914     if ((connection->authentication_flags & CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
4915     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
4916     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
4917     // LEVEL 4 always requires 128 bit encrytion key size
4918     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
4919         security_level = LEVEL_3;
4920     }
4921     return security_level;
4922 }
4923 
4924 static void hci_emit_discoverable_enabled(uint8_t enabled){
4925     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
4926     uint8_t event[3];
4927     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
4928     event[1] = sizeof(event) - 2;
4929     event[2] = enabled;
4930     hci_emit_event(event, sizeof(event), 1);
4931 }
4932 
4933 // query if remote side supports eSCO
4934 int hci_remote_esco_supported(hci_con_handle_t con_handle){
4935     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4936     if (!connection) return 0;
4937     return (connection->remote_supported_features[0] & 1) != 0;
4938 }
4939 
4940 static bool hci_ssp_supported(hci_connection_t * connection){
4941     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
4942     return (connection->bonding_flags & mask) == mask;
4943 }
4944 
4945 // query if remote side supports SSP
4946 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
4947     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4948     if (!connection) return 0;
4949     return hci_ssp_supported(connection) ? 1 : 0;
4950 }
4951 
4952 int gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
4953     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
4954 }
4955 
4956 // GAP API
4957 /**
4958  * @bbrief enable/disable bonding. default is enabled
4959  * @praram enabled
4960  */
4961 void gap_set_bondable_mode(int enable){
4962     hci_stack->bondable = enable ? 1 : 0;
4963 }
4964 /**
4965  * @brief Get bondable mode.
4966  * @return 1 if bondable
4967  */
4968 int gap_get_bondable_mode(void){
4969     return hci_stack->bondable;
4970 }
4971 
4972 /**
4973  * @brief map link keys to security levels
4974  */
4975 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
4976     switch (link_key_type){
4977         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4978             return LEVEL_4;
4979         case COMBINATION_KEY:
4980         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4981             return LEVEL_3;
4982         default:
4983             return LEVEL_2;
4984     }
4985 }
4986 
4987 /**
4988  * @brief map link keys to secure connection yes/no
4989  */
4990 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
4991     switch (link_key_type){
4992         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4993         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4994             return 1;
4995         default:
4996             return 0;
4997     }
4998 }
4999 
5000 /**
5001  * @brief map link keys to authenticated
5002  */
5003 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
5004     switch (link_key_type){
5005         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5006         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5007             return 1;
5008         default:
5009             return 0;
5010     }
5011 }
5012 
5013 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
5014     log_info("gap_mitm_protection_required_for_security_level %u", level);
5015     return level > LEVEL_2;
5016 }
5017 
5018 /**
5019  * @brief get current security level
5020  */
5021 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
5022     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5023     if (!connection) return LEVEL_0;
5024     return gap_security_level_for_connection(connection);
5025 }
5026 
5027 /**
5028  * @brief request connection to device to
5029  * @result GAP_AUTHENTICATION_RESULT
5030  */
5031 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
5032     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5033     if (!connection){
5034         hci_emit_security_level(con_handle, LEVEL_0);
5035         return;
5036     }
5037 
5038     btstack_assert(hci_is_le_connection(connection) == false);
5039 
5040     gap_security_level_t current_level = gap_security_level(con_handle);
5041     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
5042         requested_level, connection->requested_security_level, current_level);
5043 
5044     // assumption: earlier requested security higher than current level => security request is active
5045     if (current_level < connection->requested_security_level){
5046         if (connection->requested_security_level < requested_level){
5047             // increase requested level as new level is higher
5048 
5049             // TODO: handle re-authentication when done
5050 
5051             connection->requested_security_level = requested_level;
5052         }
5053         return;
5054     }
5055 
5056     // no request active, notify if security sufficient
5057     if (requested_level <= current_level){
5058         hci_emit_security_level(con_handle, current_level);
5059         return;
5060     }
5061 
5062     // store request
5063     connection->requested_security_level = requested_level;
5064 
5065     // start to authenticate connection if authentication not already active
5066     if ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
5067     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
5068     hci_run();
5069 }
5070 
5071 /**
5072  * @brief start dedicated bonding with device. disconnect after bonding
5073  * @param device
5074  * @param request MITM protection
5075  * @result GAP_DEDICATED_BONDING_COMPLETE
5076  */
5077 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
5078 
5079     // create connection state machine
5080     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
5081 
5082     if (!connection){
5083         return BTSTACK_MEMORY_ALLOC_FAILED;
5084     }
5085 
5086     // delete linkn key
5087     gap_drop_link_key_for_bd_addr(device);
5088 
5089     // configure LEVEL_2/3, dedicated bonding
5090     connection->state = SEND_CREATE_CONNECTION;
5091     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
5092     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
5093     connection->bonding_flags = BONDING_DEDICATED;
5094 
5095     // wait for GAP Security Result and send GAP Dedicated Bonding complete
5096 
5097     // handle: connnection failure (connection complete != ok)
5098     // handle: authentication failure
5099     // handle: disconnect on done
5100 
5101     hci_run();
5102 
5103     return 0;
5104 }
5105 #endif
5106 
5107 void gap_set_local_name(const char * local_name){
5108     hci_stack->local_name = local_name;
5109 }
5110 
5111 
5112 #ifdef ENABLE_BLE
5113 
5114 #ifdef ENABLE_LE_CENTRAL
5115 void gap_start_scan(void){
5116     hci_stack->le_scanning_enabled = true;
5117     hci_run();
5118 }
5119 
5120 void gap_stop_scan(void){
5121     hci_stack->le_scanning_enabled = false;
5122     hci_run();
5123 }
5124 
5125 void gap_set_scan_params(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window, uint8_t scanning_filter_policy){
5126     hci_stack->le_scan_type          = scan_type;
5127     hci_stack->le_scan_filter_policy = scanning_filter_policy;
5128     hci_stack->le_scan_interval      = scan_interval;
5129     hci_stack->le_scan_window        = scan_window;
5130     hci_stack->le_scanning_param_update = true;
5131     hci_run();
5132 }
5133 
5134 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
5135     gap_set_scan_params(scan_type, scan_interval, scan_window, 0);
5136 }
5137 
5138 uint8_t gap_connect(const bd_addr_t addr, bd_addr_type_t addr_type){
5139     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
5140     if (!conn){
5141         // disallow if le connection is already outgoing
5142         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5143             log_error("le connection already active");
5144             return ERROR_CODE_COMMAND_DISALLOWED;
5145         }
5146 
5147         log_info("gap_connect: no connection exists yet, creating context");
5148         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
5149         if (!conn){
5150             // notify client that alloc failed
5151             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5152             log_info("gap_connect: failed to alloc hci_connection_t");
5153             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
5154         }
5155 
5156         // set le connecting state
5157         if (hci_is_le_connection_type(addr_type)){
5158             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
5159         }
5160 
5161         conn->state = SEND_CREATE_CONNECTION;
5162         log_info("gap_connect: send create connection next");
5163         hci_run();
5164         return ERROR_CODE_SUCCESS;
5165     }
5166 
5167     if (!hci_is_le_connection(conn) ||
5168         (conn->state == SEND_CREATE_CONNECTION) ||
5169         (conn->state == SENT_CREATE_CONNECTION)) {
5170         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
5171         log_error("gap_connect: classic connection or connect is already being created");
5172         return GATT_CLIENT_IN_WRONG_STATE;
5173     }
5174 
5175     // check if connection was just disconnected
5176     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5177         log_info("gap_connect: send create connection (again)");
5178         conn->state = SEND_CREATE_CONNECTION;
5179         hci_run();
5180         return ERROR_CODE_SUCCESS;
5181     }
5182 
5183     log_info("gap_connect: context exists with state %u", conn->state);
5184     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
5185     hci_run();
5186     return ERROR_CODE_SUCCESS;
5187 }
5188 
5189 // @assumption: only a single outgoing LE Connection exists
5190 static hci_connection_t * gap_get_outgoing_connection(void){
5191     btstack_linked_item_t *it;
5192     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5193         hci_connection_t * conn = (hci_connection_t *) it;
5194         if (!hci_is_le_connection(conn)) continue;
5195         switch (conn->state){
5196             case SEND_CREATE_CONNECTION:
5197             case SENT_CREATE_CONNECTION:
5198             case SENT_CANCEL_CONNECTION:
5199                 return conn;
5200             default:
5201                 break;
5202         };
5203     }
5204     return NULL;
5205 }
5206 
5207 uint8_t gap_connect_cancel(void){
5208     hci_connection_t * conn = gap_get_outgoing_connection();
5209     if (!conn) return 0;
5210     switch (conn->state){
5211         case SEND_CREATE_CONNECTION:
5212             // skip sending create connection and emit event instead
5213             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5214             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5215             btstack_memory_hci_connection_free( conn );
5216             break;
5217         case SENT_CREATE_CONNECTION:
5218             // request to send cancel connection
5219             conn->state = SEND_CANCEL_CONNECTION;
5220             hci_run();
5221             break;
5222         default:
5223             break;
5224     }
5225     return 0;
5226 }
5227 #endif
5228 
5229 #ifdef ENABLE_LE_CENTRAL
5230 /**
5231  * @brief Set connection parameters for outgoing connections
5232  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5233  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5234  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5235  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5236  * @param conn_latency, default: 4
5237  * @param supervision_timeout (unit: 10ms), default: 720 ms
5238  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5239  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5240  */
5241 
5242 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5243     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5244     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5245     hci_stack->le_connection_scan_interval = conn_scan_interval;
5246     hci_stack->le_connection_scan_window = conn_scan_window;
5247     hci_stack->le_connection_interval_min = conn_interval_min;
5248     hci_stack->le_connection_interval_max = conn_interval_max;
5249     hci_stack->le_connection_latency = conn_latency;
5250     hci_stack->le_supervision_timeout = supervision_timeout;
5251     hci_stack->le_minimum_ce_length = min_ce_length;
5252     hci_stack->le_maximum_ce_length = max_ce_length;
5253 }
5254 #endif
5255 
5256 /**
5257  * @brief Updates the connection parameters for a given LE connection
5258  * @param handle
5259  * @param conn_interval_min (unit: 1.25ms)
5260  * @param conn_interval_max (unit: 1.25ms)
5261  * @param conn_latency
5262  * @param supervision_timeout (unit: 10ms)
5263  * @returns 0 if ok
5264  */
5265 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5266     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5267     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5268     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5269     connection->le_conn_interval_min = conn_interval_min;
5270     connection->le_conn_interval_max = conn_interval_max;
5271     connection->le_conn_latency = conn_latency;
5272     connection->le_supervision_timeout = supervision_timeout;
5273     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5274     hci_run();
5275     return 0;
5276 }
5277 
5278 /**
5279  * @brief Request an update of the connection parameter for a given LE connection
5280  * @param handle
5281  * @param conn_interval_min (unit: 1.25ms)
5282  * @param conn_interval_max (unit: 1.25ms)
5283  * @param conn_latency
5284  * @param supervision_timeout (unit: 10ms)
5285  * @returns 0 if ok
5286  */
5287 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5288     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5289     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5290     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5291     connection->le_conn_interval_min = conn_interval_min;
5292     connection->le_conn_interval_max = conn_interval_max;
5293     connection->le_conn_latency = conn_latency;
5294     connection->le_supervision_timeout = supervision_timeout;
5295     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5296     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5297     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5298     return 0;
5299 }
5300 
5301 #ifdef ENABLE_LE_PERIPHERAL
5302 
5303 /**
5304  * @brief Set Advertisement Data
5305  * @param advertising_data_length
5306  * @param advertising_data (max 31 octets)
5307  * @note data is not copied, pointer has to stay valid
5308  */
5309 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
5310     hci_stack->le_advertisements_data_len = advertising_data_length;
5311     hci_stack->le_advertisements_data = advertising_data;
5312     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
5313     hci_run();
5314 }
5315 
5316 /**
5317  * @brief Set Scan Response Data
5318  * @param advertising_data_length
5319  * @param advertising_data (max 31 octets)
5320  * @note data is not copied, pointer has to stay valid
5321  */
5322 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
5323     hci_stack->le_scan_response_data_len = scan_response_data_length;
5324     hci_stack->le_scan_response_data = scan_response_data;
5325     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
5326     hci_run();
5327 }
5328 
5329 /**
5330  * @brief Set Advertisement Parameters
5331  * @param adv_int_min
5332  * @param adv_int_max
5333  * @param adv_type
5334  * @param direct_address_type
5335  * @param direct_address
5336  * @param channel_map
5337  * @param filter_policy
5338  *
5339  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
5340  */
5341  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
5342     uint8_t direct_address_typ, bd_addr_t direct_address,
5343     uint8_t channel_map, uint8_t filter_policy) {
5344 
5345     hci_stack->le_advertisements_interval_min = adv_int_min;
5346     hci_stack->le_advertisements_interval_max = adv_int_max;
5347     hci_stack->le_advertisements_type = adv_type;
5348     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
5349     hci_stack->le_advertisements_channel_map = channel_map;
5350     hci_stack->le_advertisements_filter_policy = filter_policy;
5351     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
5352                  6);
5353 
5354     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5355     hci_run();
5356  }
5357 
5358 /**
5359  * @brief Enable/Disable Advertisements
5360  * @param enabled
5361  */
5362 void gap_advertisements_enable(int enabled){
5363     hci_stack->le_advertisements_enabled = enabled != 0;
5364     hci_update_advertisements_enabled_for_current_roles();
5365     hci_run();
5366 }
5367 
5368 #endif
5369 
5370 void hci_le_set_own_address_type(uint8_t own_address_type){
5371     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
5372     if (own_address_type == hci_stack->le_own_addr_type) return;
5373     hci_stack->le_own_addr_type = own_address_type;
5374 
5375 #ifdef ENABLE_LE_PERIPHERAL
5376     // update advertisement parameters, too
5377     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5378     hci_run();
5379 #endif
5380 #ifdef ENABLE_LE_CENTRAL
5381     // note: we don't update scan parameters or modify ongoing connection attempts
5382 #endif
5383 }
5384 
5385 #endif
5386 
5387 uint8_t gap_disconnect(hci_con_handle_t handle){
5388     hci_connection_t * conn = hci_connection_for_handle(handle);
5389     if (!conn){
5390         hci_emit_disconnection_complete(handle, 0);
5391         return 0;
5392     }
5393     // ignore if already disconnected
5394     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5395         return 0;
5396     }
5397     conn->state = SEND_DISCONNECT;
5398     hci_run();
5399     return 0;
5400 }
5401 
5402 int gap_read_rssi(hci_con_handle_t con_handle){
5403     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5404     if (hci_connection == NULL) return 0;
5405     connectionSetAuthenticationFlags(hci_connection, READ_RSSI);
5406     hci_run();
5407     return 1;
5408 }
5409 
5410 /**
5411  * @brief Get connection type
5412  * @param con_handle
5413  * @result connection_type
5414  */
5415 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
5416     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5417     if (!conn) return GAP_CONNECTION_INVALID;
5418     switch (conn->address_type){
5419         case BD_ADDR_TYPE_LE_PUBLIC:
5420         case BD_ADDR_TYPE_LE_RANDOM:
5421             return GAP_CONNECTION_LE;
5422         case BD_ADDR_TYPE_SCO:
5423             return GAP_CONNECTION_SCO;
5424         case BD_ADDR_TYPE_ACL:
5425             return GAP_CONNECTION_ACL;
5426         default:
5427             return GAP_CONNECTION_INVALID;
5428     }
5429 }
5430 
5431 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
5432     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5433     if (!conn) return HCI_ROLE_INVALID;
5434     return (hci_role_t) conn->role;
5435 }
5436 
5437 
5438 #ifdef ENABLE_CLASSIC
5439 uint8_t gap_request_role(const bd_addr_t addr, hci_role_t role){
5440     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5441     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5442     conn->request_role = role;
5443     hci_run();
5444     return ERROR_CODE_SUCCESS;
5445 }
5446 #endif
5447 
5448 #ifdef ENABLE_BLE
5449 
5450 uint8_t gap_le_set_phy(hci_con_handle_t connection_handle, uint8_t all_phys, uint8_t tx_phys, uint8_t rx_phys, uint8_t phy_options){
5451     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5452     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5453 
5454     conn->le_phy_update_all_phys    = all_phys;
5455     conn->le_phy_update_tx_phys     = tx_phys;
5456     conn->le_phy_update_rx_phys     = rx_phys;
5457     conn->le_phy_update_phy_options = phy_options;
5458 
5459     hci_run();
5460 
5461     return 0;
5462 }
5463 
5464 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
5465     // check if already in list
5466     btstack_linked_list_iterator_t it;
5467     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5468     while (btstack_linked_list_iterator_has_next(&it)) {
5469         whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&it);
5470         if (entry->address_type != address_type) {
5471             continue;
5472         }
5473         if (memcmp(entry->address, address, 6) != 0) {
5474             continue;
5475         }
5476 		// disallow if already scheduled to add
5477 		if ((entry->state & LE_WHITELIST_ADD_TO_CONTROLLER) != 0){
5478 			return ERROR_CODE_COMMAND_DISALLOWED;
5479 		}
5480 		// still on controller, but scheduled to remove -> re-add
5481 		entry->state |= LE_WHITELIST_ADD_TO_CONTROLLER;
5482 		return ERROR_CODE_SUCCESS;
5483     }
5484     // alloc and add to list
5485     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
5486     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
5487     entry->address_type = address_type;
5488     (void)memcpy(entry->address, address, 6);
5489     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
5490     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
5491     return ERROR_CODE_SUCCESS;
5492 }
5493 
5494 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
5495     btstack_linked_list_iterator_t it;
5496     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5497     while (btstack_linked_list_iterator_has_next(&it)){
5498         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5499         if (entry->address_type != address_type) {
5500             continue;
5501         }
5502         if (memcmp(entry->address, address, 6) != 0) {
5503             continue;
5504         }
5505         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5506             // remove from controller if already present
5507             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5508         }  else {
5509             // directly remove entry from whitelist
5510             btstack_linked_list_iterator_remove(&it);
5511             btstack_memory_whitelist_entry_free(entry);
5512         }
5513         return ERROR_CODE_SUCCESS;
5514     }
5515     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5516 }
5517 
5518 static void hci_whitelist_clear(void){
5519     btstack_linked_list_iterator_t it;
5520     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5521     while (btstack_linked_list_iterator_has_next(&it)){
5522         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5523         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5524             // remove from controller if already present
5525             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5526             continue;
5527         }
5528         // directly remove entry from whitelist
5529         btstack_linked_list_iterator_remove(&it);
5530         btstack_memory_whitelist_entry_free(entry);
5531     }
5532 }
5533 
5534 /**
5535  * @brief Clear Whitelist
5536  * @returns 0 if ok
5537  */
5538 uint8_t gap_whitelist_clear(void){
5539     hci_whitelist_clear();
5540     hci_run();
5541     return ERROR_CODE_SUCCESS;
5542 }
5543 
5544 /**
5545  * @brief Add Device to Whitelist
5546  * @param address_typ
5547  * @param address
5548  * @returns 0 if ok
5549  */
5550 uint8_t gap_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
5551     uint8_t status = hci_whitelist_add(address_type, address);
5552     if (status){
5553         return status;
5554     }
5555     hci_run();
5556     return ERROR_CODE_SUCCESS;
5557 }
5558 
5559 /**
5560  * @brief Remove Device from Whitelist
5561  * @param address_typ
5562  * @param address
5563  * @returns 0 if ok
5564  */
5565 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
5566     uint8_t status = hci_whitelist_remove(address_type, address);
5567     if (status){
5568         return status;
5569     }
5570     hci_run();
5571     return ERROR_CODE_SUCCESS;
5572 }
5573 
5574 #ifdef ENABLE_LE_CENTRAL
5575 /**
5576  *  @brief Connect with Whitelist
5577  *  @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
5578  *  @returns - if ok
5579  */
5580 uint8_t gap_connect_with_whitelist(void){
5581     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5582         return ERROR_CODE_COMMAND_DISALLOWED;
5583     }
5584     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
5585     hci_run();
5586     return ERROR_CODE_SUCCESS;
5587 }
5588 
5589 /**
5590  * @brief Auto Connection Establishment - Start Connecting to device
5591  * @param address_typ
5592  * @param address
5593  * @returns 0 if ok
5594  */
5595 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, const bd_addr_t address){
5596     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
5597         return ERROR_CODE_COMMAND_DISALLOWED;
5598     }
5599 
5600     uint8_t status = hci_whitelist_add(address_type, address);
5601     if (status == BTSTACK_MEMORY_ALLOC_FAILED) {
5602         return status;
5603     }
5604 
5605     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
5606 
5607     hci_run();
5608     return ERROR_CODE_SUCCESS;
5609 }
5610 
5611 /**
5612  * @brief Auto Connection Establishment - Stop Connecting to device
5613  * @param address_typ
5614  * @param address
5615  * @returns 0 if ok
5616  */
5617 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, const bd_addr_t address){
5618     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
5619         return ERROR_CODE_COMMAND_DISALLOWED;
5620     }
5621 
5622     hci_whitelist_remove(address_type, address);
5623     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
5624         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5625     }
5626     hci_run();
5627     return 0;
5628 }
5629 
5630 /**
5631  * @brief Auto Connection Establishment - Stop everything
5632  * @note  Convenience function to stop all active auto connection attempts
5633  */
5634 uint8_t gap_auto_connection_stop_all(void){
5635     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
5636         return ERROR_CODE_COMMAND_DISALLOWED;
5637     }
5638     hci_whitelist_clear();
5639     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5640     hci_run();
5641     return ERROR_CODE_SUCCESS;
5642 }
5643 
5644 uint16_t gap_le_connection_interval(hci_con_handle_t connection_handle){
5645     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5646     if (!conn) return 0;
5647     return conn->le_connection_interval;
5648 }
5649 #endif
5650 #endif
5651 
5652 #ifdef ENABLE_CLASSIC
5653 /**
5654  * @brief Set Extended Inquiry Response data
5655  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
5656  * @note has to be done before stack starts up
5657  */
5658 void gap_set_extended_inquiry_response(const uint8_t * data){
5659     hci_stack->eir_data = data;
5660 }
5661 
5662 /**
5663  * @brief Start GAP Classic Inquiry
5664  * @param duration in 1.28s units
5665  * @return 0 if ok
5666  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
5667  */
5668 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
5669     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
5670     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5671     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
5672         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
5673     }
5674     hci_stack->inquiry_state = duration_in_1280ms_units;
5675     hci_run();
5676     return 0;
5677 }
5678 
5679 /**
5680  * @brief Stop GAP Classic Inquiry
5681  * @returns 0 if ok
5682  */
5683 int gap_inquiry_stop(void){
5684     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
5685         // emit inquiry complete event, before it even started
5686         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
5687         hci_emit_event(event, sizeof(event), 1);
5688         return 0;
5689     }
5690     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
5691     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
5692     hci_run();
5693     return 0;
5694 }
5695 
5696 
5697 /**
5698  * @brief Remote Name Request
5699  * @param addr
5700  * @param page_scan_repetition_mode
5701  * @param clock_offset only used when bit 15 is set
5702  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
5703  */
5704 int gap_remote_name_request(const bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
5705     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5706     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
5707     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
5708     hci_stack->remote_name_clock_offset = clock_offset;
5709     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
5710     hci_run();
5711     return 0;
5712 }
5713 
5714 static int gap_pairing_set_state_and_run(const bd_addr_t addr, uint8_t state){
5715     hci_stack->gap_pairing_state = state;
5716     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
5717     hci_run();
5718     return 0;
5719 }
5720 
5721 /**
5722  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
5723  * @param addr
5724  * @param pin_data
5725  * @param pin_len
5726  * @return 0 if ok
5727  */
5728 int gap_pin_code_response_binary(const bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
5729     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5730     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
5731     hci_stack->gap_pairing_pin_len = pin_len;
5732     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
5733 }
5734 
5735 /**
5736  * @brief Legacy Pairing Pin Code Response
5737  * @param addr
5738  * @param pin
5739  * @return 0 if ok
5740  */
5741 int gap_pin_code_response(const bd_addr_t addr, const char * pin){
5742     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
5743 }
5744 
5745 /**
5746  * @brief Abort Legacy Pairing
5747  * @param addr
5748  * @param pin
5749  * @return 0 if ok
5750  */
5751 int gap_pin_code_negative(bd_addr_t addr){
5752     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5753     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
5754 }
5755 
5756 /**
5757  * @brief SSP Passkey Response
5758  * @param addr
5759  * @param passkey
5760  * @return 0 if ok
5761  */
5762 int gap_ssp_passkey_response(const bd_addr_t addr, uint32_t passkey){
5763     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5764     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
5765     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
5766 }
5767 
5768 /**
5769  * @brief Abort SSP Passkey Entry/Pairing
5770  * @param addr
5771  * @param pin
5772  * @return 0 if ok
5773  */
5774 int gap_ssp_passkey_negative(const bd_addr_t addr){
5775     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5776     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
5777 }
5778 
5779 /**
5780  * @brief Accept SSP Numeric Comparison
5781  * @param addr
5782  * @param passkey
5783  * @return 0 if ok
5784  */
5785 int gap_ssp_confirmation_response(const bd_addr_t addr){
5786     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5787     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
5788 }
5789 
5790 /**
5791  * @brief Abort SSP Numeric Comparison/Pairing
5792  * @param addr
5793  * @param pin
5794  * @return 0 if ok
5795  */
5796 int gap_ssp_confirmation_negative(const bd_addr_t addr){
5797     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5798     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
5799 }
5800 
5801 /**
5802  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
5803  * @param inquiry_mode see bluetooth_defines.h
5804  */
5805 void hci_set_inquiry_mode(inquiry_mode_t mode){
5806     hci_stack->inquiry_mode = mode;
5807 }
5808 
5809 /**
5810  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
5811  */
5812 void hci_set_sco_voice_setting(uint16_t voice_setting){
5813     hci_stack->sco_voice_setting = voice_setting;
5814 }
5815 
5816 /**
5817  * @brief Get SCO Voice Setting
5818  * @return current voice setting
5819  */
5820 uint16_t hci_get_sco_voice_setting(void){
5821     return hci_stack->sco_voice_setting;
5822 }
5823 
5824 static int hci_have_usb_transport(void){
5825     if (!hci_stack->hci_transport) return 0;
5826     const char * transport_name = hci_stack->hci_transport->name;
5827     if (!transport_name) return 0;
5828     return (transport_name[0] == 'H') && (transport_name[1] == '2');
5829 }
5830 
5831 /** @brief Get SCO packet length for current SCO Voice setting
5832  *  @note  Using SCO packets of the exact length is required for USB transfer
5833  *  @return Length of SCO packets in bytes (not audio frames)
5834  */
5835 int hci_get_sco_packet_length(void){
5836     int sco_packet_length = 0;
5837 
5838 #ifdef ENABLE_SCO_OVER_HCI
5839 
5840     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
5841     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
5842 
5843     if (hci_have_usb_transport()){
5844         // see Core Spec for H2 USB Transfer.
5845         // 3 byte SCO header + 24 bytes per connection
5846         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
5847         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
5848     } else {
5849         // 3 byte SCO header + SCO packet size over the air (60 bytes)
5850         sco_packet_length = 3 + 60 * multiplier;
5851         // assert that it still fits inside an SCO buffer
5852         if (sco_packet_length > hci_stack->sco_data_packet_length){
5853             sco_packet_length = 3 + 60;
5854         }
5855     }
5856 #endif
5857     return sco_packet_length;
5858 }
5859 
5860 /**
5861 * @brief Sets the master/slave policy
5862 * @param policy (0: attempt to become master, 1: let connecting device decide)
5863 */
5864 void hci_set_master_slave_policy(uint8_t policy){
5865     hci_stack->master_slave_policy = policy;
5866 }
5867 
5868 #endif
5869 
5870 HCI_STATE hci_get_state(void){
5871     return hci_stack->state;
5872 }
5873 
5874 #ifdef ENABLE_CLASSIC
5875 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr)){
5876     hci_stack->gap_classic_accept_callback = accept_callback;
5877 }
5878 #endif
5879 
5880 /**
5881  * @brief Set callback for Bluetooth Hardware Error
5882  */
5883 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
5884     hci_stack->hardware_error_callback = fn;
5885 }
5886 
5887 void hci_disconnect_all(void){
5888     btstack_linked_list_iterator_t it;
5889     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5890     while (btstack_linked_list_iterator_has_next(&it)){
5891         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5892         if (con->state == SENT_DISCONNECT) continue;
5893         con->state = SEND_DISCONNECT;
5894     }
5895     hci_run();
5896 }
5897 
5898 uint16_t hci_get_manufacturer(void){
5899     return hci_stack->manufacturer;
5900 }
5901 
5902 #ifdef ENABLE_BLE
5903 
5904 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
5905     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
5906     if (!hci_con) return NULL;
5907     return &hci_con->sm_connection;
5908 }
5909 
5910 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
5911 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
5912 
5913 int gap_encryption_key_size(hci_con_handle_t con_handle){
5914     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5915     if (hci_connection == NULL) return 0;
5916     if (hci_is_le_connection(hci_connection)){
5917         sm_connection_t * sm_conn = &hci_connection->sm_connection;
5918         if (sm_conn->sm_connection_encrypted) {
5919             return sm_conn->sm_actual_encryption_key_size;
5920         }
5921     }
5922 #ifdef ENABLE_CLASSIC
5923     else {
5924         if ((hci_connection->authentication_flags & CONNECTION_ENCRYPTED)){
5925             return hci_connection->encryption_key_size;
5926         }
5927     }
5928 #endif
5929     return 0;
5930 }
5931 
5932 int gap_authenticated(hci_con_handle_t con_handle){
5933     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5934     if (hci_connection == NULL) return 0;
5935 
5936     switch (hci_connection->address_type){
5937         case BD_ADDR_TYPE_LE_PUBLIC:
5938         case BD_ADDR_TYPE_LE_RANDOM:
5939             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5940             return hci_connection->sm_connection.sm_connection_authenticated;
5941 #ifdef ENABLE_CLASSIC
5942         case BD_ADDR_TYPE_SCO:
5943         case BD_ADDR_TYPE_ACL:
5944             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
5945 #endif
5946         default:
5947             return 0;
5948     }
5949 }
5950 
5951 int gap_secure_connection(hci_con_handle_t con_handle){
5952     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5953     if (hci_connection == NULL) return 0;
5954 
5955     switch (hci_connection->address_type){
5956         case BD_ADDR_TYPE_LE_PUBLIC:
5957         case BD_ADDR_TYPE_LE_RANDOM:
5958             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5959             return hci_connection->sm_connection.sm_connection_sc;
5960 #ifdef ENABLE_CLASSIC
5961         case BD_ADDR_TYPE_SCO:
5962         case BD_ADDR_TYPE_ACL:
5963             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
5964 #endif
5965         default:
5966             return 0;
5967     }
5968 }
5969 
5970 bool gap_bonded(hci_con_handle_t con_handle){
5971 	hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5972 	if (hci_connection == NULL) return 0;
5973 
5974 #ifdef ENABLE_CLASSIC
5975 	link_key_t link_key;
5976 	link_key_type_t link_key_type;
5977 #endif
5978 	switch (hci_connection->address_type){
5979 		case BD_ADDR_TYPE_LE_PUBLIC:
5980 		case BD_ADDR_TYPE_LE_RANDOM:
5981 			return hci_connection->sm_connection.sm_le_db_index >= 0;
5982 #ifdef ENABLE_CLASSIC
5983 		case BD_ADDR_TYPE_SCO:
5984 		case BD_ADDR_TYPE_ACL:
5985 			return hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(hci_connection->address, link_key, &link_key_type);
5986 #endif
5987 		default:
5988 			return false;
5989 	}
5990 }
5991 
5992 
5993 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
5994     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
5995     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
5996     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
5997     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
5998     return sm_conn->sm_connection_authorization_state;
5999 }
6000 #endif
6001 
6002 #ifdef ENABLE_CLASSIC
6003 uint8_t gap_sniff_mode_enter(hci_con_handle_t con_handle, uint16_t sniff_min_interval, uint16_t sniff_max_interval, uint16_t sniff_attempt, uint16_t sniff_timeout){
6004     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6005     if (!conn) return GAP_CONNECTION_INVALID;
6006     conn->sniff_min_interval = sniff_min_interval;
6007     conn->sniff_max_interval = sniff_max_interval;
6008     conn->sniff_attempt = sniff_attempt;
6009     conn->sniff_timeout = sniff_timeout;
6010     hci_run();
6011     return 0;
6012 }
6013 
6014 /**
6015  * @brief Exit Sniff mode
6016  * @param con_handle
6017  @ @return 0 if ok
6018  */
6019 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
6020     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6021     if (!conn) return GAP_CONNECTION_INVALID;
6022     conn->sniff_min_interval = 0xffff;
6023     hci_run();
6024     return 0;
6025 }
6026 #endif
6027 
6028 void hci_halting_defer(void){
6029     if (hci_stack->state != HCI_STATE_HALTING) return;
6030     switch (hci_stack->substate){
6031         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
6032         case HCI_HALTING_CLOSE:
6033             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
6034             break;
6035         default:
6036             break;
6037     }
6038 }
6039 
6040 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
6041 void hci_load_le_device_db_entry_into_resolving_list(uint16_t le_device_db_index){
6042     if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6043     if (le_device_db_index >= le_device_db_max_count()) return;
6044     uint8_t offset = le_device_db_index >> 3;
6045     uint8_t mask = 1 << (le_device_db_index & 7);
6046     hci_stack->le_resolving_list_add_entries[offset] |= mask;
6047     if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6048     	// note: go back to remove entries, otherwise, a remove + add will skip the add
6049         hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6050     }
6051 }
6052 
6053 void hci_remove_le_device_db_entry_from_resolving_list(uint16_t le_device_db_index){
6054 	if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6055 	if (le_device_db_index >= le_device_db_max_count()) return;
6056 	uint8_t offset = le_device_db_index >> 3;
6057 	uint8_t mask = 1 << (le_device_db_index & 7);
6058 	hci_stack->le_resolving_list_remove_entries[offset] |= mask;
6059 	if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6060 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6061 	}
6062 }
6063 
6064 uint8_t gap_load_resolving_list_from_le_device_db(void){
6065 	if ((hci_stack->local_supported_commands[1] & (1 << 2)) == 0) {
6066 		return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
6067 	}
6068 	if (hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION){
6069 		// restart le resolving list update
6070 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
6071 	}
6072 	return ERROR_CODE_SUCCESS;
6073 }
6074 #endif
6075 
6076 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
6077 void hci_setup_test_connections_fuzz(void){
6078     hci_connection_t * conn;
6079 
6080     // default address: 66:55:44:33:00:01
6081     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
6082 
6083     // setup Controller info
6084     hci_stack->num_cmd_packets = 255;
6085     hci_stack->acl_packets_total_num = 255;
6086 
6087     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
6088     addr[5] = 0x01;
6089     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6090     conn->con_handle = addr[5];
6091     conn->role  = HCI_ROLE_SLAVE;
6092     conn->state = RECEIVED_CONNECTION_REQUEST;
6093     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6094 
6095     // setup incoming Classic SCO connection with con handle 0x0002
6096     addr[5] = 0x02;
6097     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6098     conn->con_handle = addr[5];
6099     conn->role  = HCI_ROLE_SLAVE;
6100     conn->state = RECEIVED_CONNECTION_REQUEST;
6101     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6102 
6103     // setup ready Classic ACL connection with con handle 0x0003
6104     addr[5] = 0x03;
6105     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6106     conn->con_handle = addr[5];
6107     conn->role  = HCI_ROLE_SLAVE;
6108     conn->state = OPEN;
6109     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6110 
6111     // setup ready Classic SCO connection with con handle 0x0004
6112     addr[5] = 0x04;
6113     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6114     conn->con_handle = addr[5];
6115     conn->role  = HCI_ROLE_SLAVE;
6116     conn->state = OPEN;
6117     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6118 
6119     // setup ready LE ACL connection with con handle 0x005 and public address
6120     addr[5] = 0x05;
6121     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
6122     conn->con_handle = addr[5];
6123     conn->role  = HCI_ROLE_SLAVE;
6124     conn->state = OPEN;
6125     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6126 }
6127 
6128 void hci_free_connections_fuzz(void){
6129     btstack_linked_list_iterator_t it;
6130     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6131     while (btstack_linked_list_iterator_has_next(&it)){
6132         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6133         btstack_linked_list_iterator_remove(&it);
6134         btstack_memory_hci_connection_free(con);
6135     }
6136 }
6137 void hci_simulate_working_fuzz(void){
6138     hci_init_done();
6139     hci_stack->num_cmd_packets = 255;
6140 }
6141 #endif
6142