xref: /btstack/src/hci.c (revision a3b69fde2a072dd4de0a84fe13f4210754a06b30)
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 #endif
63 
64 #include <stdarg.h>
65 #include <string.h>
66 #include <inttypes.h>
67 
68 #include "btstack_debug.h"
69 #include "btstack_event.h"
70 #include "btstack_linked_list.h"
71 #include "btstack_memory.h"
72 #include "bluetooth_company_id.h"
73 #include "bluetooth_data_types.h"
74 #include "gap.h"
75 #include "hci.h"
76 #include "hci_cmd.h"
77 #include "hci_dump.h"
78 #include "ad_parser.h"
79 
80 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
81 #ifndef HCI_HOST_ACL_PACKET_NUM
82 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
83 #endif
84 #ifndef HCI_HOST_ACL_PACKET_LEN
85 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
86 #endif
87 #ifndef HCI_HOST_SCO_PACKET_NUM
88 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
89 #endif
90 #ifndef HCI_HOST_SCO_PACKET_LEN
91 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
92 #endif
93 #endif
94 
95 #define HCI_CONNECTION_TIMEOUT_MS 10000
96 
97 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
98 #define HCI_RESET_RESEND_TIMEOUT_MS 200
99 #endif
100 
101 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
102 #ifndef GAP_INQUIRY_MAX_NAME_LEN
103 #define GAP_INQUIRY_MAX_NAME_LEN 32
104 #endif
105 
106 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
107 #define GAP_INQUIRY_DURATION_MIN 0x01
108 #define GAP_INQUIRY_DURATION_MAX 0x30
109 #define GAP_INQUIRY_STATE_ACTIVE 0x80
110 #define GAP_INQUIRY_STATE_IDLE 0
111 #define GAP_INQUIRY_STATE_W2_CANCEL 0x81
112 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x82
113 
114 // GAP Remote Name Request
115 #define GAP_REMOTE_NAME_STATE_IDLE 0
116 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
117 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
118 
119 // GAP Pairing
120 #define GAP_PAIRING_STATE_IDLE                       0
121 #define GAP_PAIRING_STATE_SEND_PIN                   1
122 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
123 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
124 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
125 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
126 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
127 
128 
129 // prototypes
130 #ifdef ENABLE_CLASSIC
131 static void hci_update_scan_enable(void);
132 static void hci_emit_discoverable_enabled(uint8_t enabled);
133 static int  hci_local_ssp_activated(void);
134 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
135 static bool hci_ssp_supported(hci_connection_t * connection);
136 static void hci_notify_if_sco_can_send_now(void);
137 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
138 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
139 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
140 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
141 static void hci_connection_timestamp(hci_connection_t *connection);
142 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
143 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
144 #endif
145 
146 static int  hci_power_control_on(void);
147 static void hci_power_control_off(void);
148 static void hci_state_reset(void);
149 static void hci_emit_transport_packet_sent(void);
150 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
151 static void hci_emit_nr_connections_changed(void);
152 static void hci_emit_hci_open_failed(void);
153 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
154 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
155 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
156 static void hci_run(void);
157 static int  hci_is_le_connection(hci_connection_t * connection);
158 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
159 
160 #ifdef ENABLE_CLASSIC
161 static int hci_have_usb_transport(void);
162 #endif
163 
164 #ifdef ENABLE_BLE
165 #ifdef ENABLE_LE_CENTRAL
166 // called from test/ble_client/advertising_data_parser.c
167 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
168 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, bd_addr_t address);
169 static hci_connection_t * gap_get_outgoing_connection(void);
170 #endif
171 #endif
172 
173 // the STACK is here
174 #ifndef HAVE_MALLOC
175 static hci_stack_t   hci_stack_static;
176 #endif
177 static hci_stack_t * hci_stack = NULL;
178 
179 #ifdef ENABLE_CLASSIC
180 // default name
181 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
182 
183 // test helper
184 static uint8_t disable_l2cap_timeouts = 0;
185 #endif
186 
187 /**
188  * create connection for given address
189  *
190  * @return connection OR NULL, if no memory left
191  */
192 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
193     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
194     hci_connection_t * conn = btstack_memory_hci_connection_get();
195     if (!conn) return NULL;
196     bd_addr_copy(conn->address, addr);
197     conn->role = HCI_ROLE_INVALID;
198     conn->address_type = addr_type;
199     conn->con_handle = 0xffff;
200     conn->authentication_flags = AUTH_FLAGS_NONE;
201     conn->bonding_flags = 0;
202     conn->requested_security_level = LEVEL_0;
203 #ifdef ENABLE_CLASSIC
204     conn->request_role = HCI_ROLE_INVALID;
205     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
206     btstack_run_loop_set_timer_context(&conn->timeout, conn);
207     hci_connection_timestamp(conn);
208 #endif
209     conn->acl_recombination_length = 0;
210     conn->acl_recombination_pos = 0;
211     conn->num_packets_sent = 0;
212 
213     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
214 #ifdef ENABLE_BLE
215     conn->le_phy_update_all_phys = 0xff;
216 #endif
217 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
218     conn->le_max_tx_octets = 27;
219 #endif
220     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
221     return conn;
222 }
223 
224 
225 /**
226  * get le connection parameter range
227 *
228  * @return le connection parameter range struct
229  */
230 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
231     *range = hci_stack->le_connection_parameter_range;
232 }
233 
234 /**
235  * set le connection parameter range
236  *
237  */
238 
239 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
240     hci_stack->le_connection_parameter_range = *range;
241 }
242 
243 /**
244  * @brief Test if connection parameters are inside in existing rage
245  * @param conn_interval_min (unit: 1.25ms)
246  * @param conn_interval_max (unit: 1.25ms)
247  * @param conn_latency
248  * @param supervision_timeout (unit: 10ms)
249  * @returns 1 if included
250  */
251 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){
252     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
253     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
254 
255     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
256     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
257 
258     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
259     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
260 
261     return 1;
262 }
263 
264 /**
265  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
266  * @note: default: 1
267  * @param max_peripheral_connections
268  */
269 #ifdef ENABLE_LE_PERIPHERAL
270 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
271     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
272 }
273 #endif
274 
275 /**
276  * get hci connections iterator
277  *
278  * @return hci connections iterator
279  */
280 
281 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
282     btstack_linked_list_iterator_init(it, &hci_stack->connections);
283 }
284 
285 /**
286  * get connection for a given handle
287  *
288  * @return connection OR NULL, if not found
289  */
290 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
291     btstack_linked_list_iterator_t it;
292     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
293     while (btstack_linked_list_iterator_has_next(&it)){
294         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
295         if ( item->con_handle == con_handle ) {
296             return item;
297         }
298     }
299     return NULL;
300 }
301 
302 /**
303  * get connection for given address
304  *
305  * @return connection OR NULL, if not found
306  */
307 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t  addr, bd_addr_type_t addr_type){
308     btstack_linked_list_iterator_t it;
309     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
310     while (btstack_linked_list_iterator_has_next(&it)){
311         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
312         if (connection->address_type != addr_type)  continue;
313         if (memcmp(addr, connection->address, 6) != 0) continue;
314         return connection;
315     }
316     return NULL;
317 }
318 
319 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
320     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
321 }
322 
323 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
324     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
325 }
326 
327 #ifdef ENABLE_CLASSIC
328 
329 #ifdef ENABLE_SCO_OVER_HCI
330 static int hci_number_sco_connections(void){
331     int connections = 0;
332     btstack_linked_list_iterator_t it;
333     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
334     while (btstack_linked_list_iterator_has_next(&it)){
335         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
336         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
337         connections++;
338     }
339     return connections;
340 }
341 #endif
342 
343 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
344     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
345 #ifdef HAVE_EMBEDDED_TICK
346     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
347         // connections might be timed out
348         hci_emit_l2cap_check_timeout(connection);
349     }
350 #else
351     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
352         // connections might be timed out
353         hci_emit_l2cap_check_timeout(connection);
354     }
355 #endif
356 }
357 
358 static void hci_connection_timestamp(hci_connection_t *connection){
359 #ifdef HAVE_EMBEDDED_TICK
360     connection->timestamp = btstack_run_loop_embedded_get_ticks();
361 #else
362     connection->timestamp = btstack_run_loop_get_time_ms();
363 #endif
364 }
365 
366 /**
367  * add authentication flags and reset timer
368  * @note: assumes classic connection
369  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
370  */
371 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
372     bd_addr_t addr;
373     reverse_bd_addr(bd_addr, addr);
374     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
375     if (conn) {
376         connectionSetAuthenticationFlags(conn, flags);
377         hci_connection_timestamp(conn);
378     }
379 }
380 
381 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
382     hci_connection_t * conn = hci_connection_for_handle(handle);
383     if (!conn) return 0;
384     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
385     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
386     return 0;
387 }
388 
389 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
390     if (!hci_stack->link_key_db) return;
391     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
392     hci_stack->link_key_db->delete_link_key(addr);
393 }
394 
395 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
396     if (!hci_stack->link_key_db) return;
397     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
398     hci_stack->link_key_db->put_link_key(addr, link_key, type);
399 }
400 
401 void gap_delete_all_link_keys(void){
402     bd_addr_t  addr;
403     link_key_t link_key;
404     link_key_type_t type;
405     btstack_link_key_iterator_t it;
406     int ok = gap_link_key_iterator_init(&it);
407     if (!ok) {
408         log_error("could not initialize iterator");
409         return;
410     }
411     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
412         gap_drop_link_key_for_bd_addr(addr);
413     }
414     gap_link_key_iterator_done(&it);
415 }
416 
417 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
418     if (!hci_stack->link_key_db) return 0;
419     if (!hci_stack->link_key_db->iterator_init) return 0;
420     return hci_stack->link_key_db->iterator_init(it);
421 }
422 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){
423     if (!hci_stack->link_key_db) return 0;
424     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
425 }
426 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
427     if (!hci_stack->link_key_db) return;
428     hci_stack->link_key_db->iterator_done(it);
429 }
430 #endif
431 
432 static bool hci_is_le_connection_type(bd_addr_type_t address_type){
433     switch (address_type){
434         case BD_ADDR_TYPE_LE_PUBLIC:
435         case BD_ADDR_TYPE_LE_RANDOM:
436         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
437         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
438             return true;
439         default:
440             return false;
441     }
442 }
443 
444 static int hci_is_le_connection(hci_connection_t * connection){
445     return hci_is_le_connection_type(connection->address_type);
446 }
447 
448 /**
449  * count connections
450  */
451 static int nr_hci_connections(void){
452     int count = 0;
453     btstack_linked_item_t *it;
454     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
455         count++;
456     }
457     return count;
458 }
459 
460 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
461 
462     unsigned int num_packets_sent_classic = 0;
463     unsigned int num_packets_sent_le = 0;
464 
465     btstack_linked_item_t *it;
466     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
467         hci_connection_t * connection = (hci_connection_t *) it;
468         if (hci_is_le_connection(connection)){
469             num_packets_sent_le += connection->num_packets_sent;
470         }
471         if (connection->address_type == BD_ADDR_TYPE_ACL){
472             num_packets_sent_classic += connection->num_packets_sent;
473         }
474     }
475     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
476     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
477     int free_slots_le = 0;
478 
479     if (free_slots_classic < 0){
480         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);
481         return 0;
482     }
483 
484     if (hci_stack->le_acl_packets_total_num){
485         // if we have LE slots, they are used
486         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
487         if (free_slots_le < 0){
488             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);
489             return 0;
490         }
491     } else {
492         // otherwise, classic slots are used for LE, too
493         free_slots_classic -= num_packets_sent_le;
494         if (free_slots_classic < 0){
495             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);
496             return 0;
497         }
498     }
499 
500     switch (address_type){
501         case BD_ADDR_TYPE_UNKNOWN:
502             log_error("hci_number_free_acl_slots: unknown address type");
503             return 0;
504 
505         case BD_ADDR_TYPE_ACL:
506             return free_slots_classic;
507 
508         default:
509            if (hci_stack->le_acl_packets_total_num){
510                return free_slots_le;
511            }
512            return free_slots_classic;
513     }
514 }
515 
516 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
517     // get connection type
518     hci_connection_t * connection = hci_connection_for_handle(con_handle);
519     if (!connection){
520         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
521         return 0;
522     }
523     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
524 }
525 
526 #ifdef ENABLE_CLASSIC
527 static int hci_number_free_sco_slots(void){
528     unsigned int num_sco_packets_sent  = 0;
529     btstack_linked_item_t *it;
530     if (hci_stack->synchronous_flow_control_enabled){
531         // explicit flow control
532         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
533             hci_connection_t * connection = (hci_connection_t *) it;
534             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
535             num_sco_packets_sent += connection->num_packets_sent;
536         }
537         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
538             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
539             return 0;
540         }
541         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
542     } else {
543         // implicit flow control -- TODO
544         int num_ready = 0;
545         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
546             hci_connection_t * connection = (hci_connection_t *) it;
547             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
548             if (connection->sco_tx_ready == 0) continue;
549             num_ready++;
550         }
551         return num_ready;
552     }
553 }
554 #endif
555 
556 // only used to send HCI Host Number Completed Packets
557 static int hci_can_send_comand_packet_transport(void){
558     if (hci_stack->hci_packet_buffer_reserved) return 0;
559 
560     // check for async hci transport implementations
561     if (hci_stack->hci_transport->can_send_packet_now){
562         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
563             return 0;
564         }
565     }
566     return 1;
567 }
568 
569 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
570 int hci_can_send_command_packet_now(void){
571     if (hci_can_send_comand_packet_transport() == 0) return 0;
572     return hci_stack->num_cmd_packets > 0u;
573 }
574 
575 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
576     // check for async hci transport implementations
577     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
578     return hci_stack->hci_transport->can_send_packet_now(packet_type);
579 }
580 
581 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
582     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
583     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
584 }
585 
586 int hci_can_send_acl_le_packet_now(void){
587     if (hci_stack->hci_packet_buffer_reserved) return 0;
588     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
589 }
590 
591 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
592     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
593     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
594 }
595 
596 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
597     if (hci_stack->hci_packet_buffer_reserved) return 0;
598     return hci_can_send_prepared_acl_packet_now(con_handle);
599 }
600 
601 #ifdef ENABLE_CLASSIC
602 int hci_can_send_acl_classic_packet_now(void){
603     if (hci_stack->hci_packet_buffer_reserved) return 0;
604     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
605 }
606 
607 int hci_can_send_prepared_sco_packet_now(void){
608     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return 0;
609     if (hci_have_usb_transport()){
610         return hci_stack->sco_can_send_now;
611     } else {
612         return hci_number_free_sco_slots() > 0;
613     }
614 }
615 
616 int hci_can_send_sco_packet_now(void){
617     if (hci_stack->hci_packet_buffer_reserved) return 0;
618     return hci_can_send_prepared_sco_packet_now();
619 }
620 
621 void hci_request_sco_can_send_now_event(void){
622     hci_stack->sco_waiting_for_can_send_now = 1;
623     hci_notify_if_sco_can_send_now();
624 }
625 #endif
626 
627 // used for internal checks in l2cap.c
628 int hci_is_packet_buffer_reserved(void){
629     return hci_stack->hci_packet_buffer_reserved;
630 }
631 
632 // reserves outgoing packet buffer. @returns 1 if successful
633 int hci_reserve_packet_buffer(void){
634     if (hci_stack->hci_packet_buffer_reserved) {
635         log_error("hci_reserve_packet_buffer called but buffer already reserved");
636         return 0;
637     }
638     hci_stack->hci_packet_buffer_reserved = 1;
639     return 1;
640 }
641 
642 void hci_release_packet_buffer(void){
643     hci_stack->hci_packet_buffer_reserved = 0;
644 }
645 
646 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
647 static int hci_transport_synchronous(void){
648     return hci_stack->hci_transport->can_send_packet_now == NULL;
649 }
650 
651 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
652 
653     // 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);
654 
655     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
656     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
657     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0u)){
658         max_acl_data_packet_length = hci_stack->le_data_packets_length;
659     }
660 
661 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
662     if (hci_is_le_connection(connection)){
663         max_acl_data_packet_length = connection->le_max_tx_octets;
664     }
665 #endif
666 
667     log_debug("hci_send_acl_packet_fragments entered");
668 
669     int err;
670     // multiple packets could be send on a synchronous HCI transport
671     while (true){
672 
673         log_debug("hci_send_acl_packet_fragments loop entered");
674 
675         // get current data
676         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4u;
677         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
678         int more_fragments = 0;
679 
680         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
681         if (current_acl_data_packet_length > max_acl_data_packet_length){
682             more_fragments = 1;
683             current_acl_data_packet_length = max_acl_data_packet_length;
684         }
685 
686         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
687         if (acl_header_pos > 0u){
688             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
689             handle_and_flags = (handle_and_flags & 0xcfffu) | (1u << 12u);
690             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
691         }
692 
693         // update header len
694         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2u, current_acl_data_packet_length);
695 
696         // count packet
697         connection->num_packets_sent++;
698         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", more_fragments);
699 
700         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
701         if (more_fragments){
702             // update start of next fragment to send
703             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
704         } else {
705             // done
706             hci_stack->acl_fragmentation_pos = 0;
707             hci_stack->acl_fragmentation_total_size = 0;
708         }
709 
710         // send packet
711         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
712         const int size = current_acl_data_packet_length + 4;
713         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
714         hci_stack->acl_fragmentation_tx_active = 1;
715         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
716 
717         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", more_fragments);
718 
719         // done yet?
720         if (!more_fragments) break;
721 
722         // can send more?
723         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
724     }
725 
726     log_debug("hci_send_acl_packet_fragments loop over");
727 
728     // release buffer now for synchronous transport
729     if (hci_transport_synchronous()){
730         hci_stack->acl_fragmentation_tx_active = 0;
731         hci_release_packet_buffer();
732         hci_emit_transport_packet_sent();
733     }
734 
735     return err;
736 }
737 
738 // pre: caller has reserved the packet buffer
739 int hci_send_acl_packet_buffer(int size){
740 
741     // log_info("hci_send_acl_packet_buffer size %u", size);
742 
743     if (!hci_stack->hci_packet_buffer_reserved) {
744         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
745         return 0;
746     }
747 
748     uint8_t * packet = hci_stack->hci_packet_buffer;
749     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
750 
751     // check for free places on Bluetooth module
752     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
753         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
754         hci_release_packet_buffer();
755         hci_emit_transport_packet_sent();
756         return BTSTACK_ACL_BUFFERS_FULL;
757     }
758 
759     hci_connection_t *connection = hci_connection_for_handle( con_handle);
760     if (!connection) {
761         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
762         hci_release_packet_buffer();
763         hci_emit_transport_packet_sent();
764         return 0;
765     }
766 
767 #ifdef ENABLE_CLASSIC
768     hci_connection_timestamp(connection);
769 #endif
770 
771     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
772 
773     // setup data
774     hci_stack->acl_fragmentation_total_size = size;
775     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
776 
777     return hci_send_acl_packet_fragments(connection);
778 }
779 
780 #ifdef ENABLE_CLASSIC
781 // pre: caller has reserved the packet buffer
782 int hci_send_sco_packet_buffer(int size){
783 
784     // log_info("hci_send_acl_packet_buffer size %u", size);
785 
786     if (!hci_stack->hci_packet_buffer_reserved) {
787         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
788         return 0;
789     }
790 
791     uint8_t * packet = hci_stack->hci_packet_buffer;
792 
793     // skip checks in loopback mode
794     if (!hci_stack->loopback_mode){
795         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
796 
797         // check for free places on Bluetooth module
798         if (!hci_can_send_prepared_sco_packet_now()) {
799             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
800             hci_release_packet_buffer();
801             hci_emit_transport_packet_sent();
802             return BTSTACK_ACL_BUFFERS_FULL;
803         }
804 
805         // track send packet in connection struct
806         hci_connection_t *connection = hci_connection_for_handle( con_handle);
807         if (!connection) {
808             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
809             hci_release_packet_buffer();
810             hci_emit_transport_packet_sent();
811             return 0;
812         }
813 
814         if (hci_have_usb_transport()){
815             // token used
816             hci_stack->sco_can_send_now = 0;
817         } else {
818             if (hci_stack->synchronous_flow_control_enabled){
819                 connection->num_packets_sent++;
820             } else {
821                 connection->sco_tx_ready--;
822             }
823         }
824     }
825 
826     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
827     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
828 
829     if (hci_transport_synchronous()){
830         hci_release_packet_buffer();
831         hci_emit_transport_packet_sent();
832     }
833 
834     return err;
835 }
836 #endif
837 
838 static void acl_handler(uint8_t *packet, uint16_t size){
839 
840     // get info
841     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
842     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
843     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
844     uint16_t acl_length         = READ_ACL_LENGTH(packet);
845 
846     // ignore non-registered handle
847     if (!conn){
848         log_error("acl_handler called with non-registered handle %u!" , con_handle);
849         return;
850     }
851 
852     // assert packet is complete
853     if ((acl_length + 4u) != size){
854         log_error("acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
855         return;
856     }
857 
858 #ifdef ENABLE_CLASSIC
859     // update idle timestamp
860     hci_connection_timestamp(conn);
861 #endif
862 
863 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
864     hci_stack->host_completed_packets = 1;
865     conn->num_packets_completed++;
866 #endif
867 
868     // handle different packet types
869     switch (acl_flags & 0x03u) {
870 
871         case 0x01: // continuation fragment
872 
873             // sanity checks
874             if (conn->acl_recombination_pos == 0u) {
875                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
876                 return;
877             }
878             if ((conn->acl_recombination_pos + acl_length) > (4u + HCI_ACL_BUFFER_SIZE)){
879                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
880                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
881                 conn->acl_recombination_pos = 0;
882                 return;
883             }
884 
885             // append fragment payload (header already stored)
886             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
887                          &packet[4], acl_length);
888             conn->acl_recombination_pos += acl_length;
889 
890             // forward complete L2CAP packet if complete.
891             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4u + 4u)){ // pos already incl. ACL header
892                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
893                 // reset recombination buffer
894                 conn->acl_recombination_length = 0;
895                 conn->acl_recombination_pos = 0;
896             }
897             break;
898 
899         case 0x02: { // first fragment
900 
901             // sanity check
902             if (conn->acl_recombination_pos) {
903                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
904                 conn->acl_recombination_pos = 0;
905             }
906 
907             // peek into L2CAP packet!
908             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
909 
910             // compare fragment size to L2CAP packet size
911             if (acl_length >= (l2cap_length + 4u)){
912                 // forward fragment as L2CAP packet
913                 hci_emit_acl_packet(packet, acl_length + 4u);
914             } else {
915 
916                 if (acl_length > HCI_ACL_BUFFER_SIZE){
917                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
918                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
919                     return;
920                 }
921 
922                 // store first fragment and tweak acl length for complete package
923                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
924                              packet, acl_length + 4u);
925                 conn->acl_recombination_pos    = acl_length + 4u;
926                 conn->acl_recombination_length = l2cap_length;
927                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2u, l2cap_length +4u);
928             }
929             break;
930 
931         }
932         default:
933             log_error( "acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
934             return;
935     }
936 
937     // execute main loop
938     hci_run();
939 }
940 
941 static void hci_shutdown_connection(hci_connection_t *conn){
942     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
943 
944 #ifdef ENABLE_CLASSIC
945 #ifdef ENABLE_SCO_OVER_HCI
946     int addr_type = conn->address_type;
947 #endif
948 #endif
949 
950     btstack_run_loop_remove_timer(&conn->timeout);
951 
952     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
953     btstack_memory_hci_connection_free( conn );
954 
955     // now it's gone
956     hci_emit_nr_connections_changed();
957 
958 #ifdef ENABLE_CLASSIC
959 #ifdef ENABLE_SCO_OVER_HCI
960     // update SCO
961     if (addr_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
962         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
963     }
964 #endif
965 #endif
966 }
967 
968 #ifdef ENABLE_CLASSIC
969 
970 static const uint16_t packet_type_sizes[] = {
971     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
972     HCI_ACL_DH1_SIZE, 0, 0, 0,
973     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
974     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
975 };
976 static const uint8_t  packet_type_feature_requirement_bit[] = {
977      0, // 3 slot packets
978      1, // 5 slot packets
979     25, // EDR 2 mpbs
980     26, // EDR 3 mbps
981     39, // 3 slot EDR packts
982     40, // 5 slot EDR packet
983 };
984 static const uint16_t packet_type_feature_packet_mask[] = {
985     0x0f00, // 3 slot packets
986     0xf000, // 5 slot packets
987     0x1102, // EDR 2 mpbs
988     0x2204, // EDR 3 mbps
989     0x0300, // 3 slot EDR packts
990     0x3000, // 5 slot EDR packet
991 };
992 
993 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
994     // enable packet types based on size
995     uint16_t packet_types = 0;
996     unsigned int i;
997     for (i=0;i<16;i++){
998         if (packet_type_sizes[i] == 0) continue;
999         if (packet_type_sizes[i] <= buffer_size){
1000             packet_types |= 1 << i;
1001         }
1002     }
1003     // disable packet types due to missing local supported features
1004     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1005         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1006         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1007         if (feature_set) continue;
1008         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1009         packet_types &= ~packet_type_feature_packet_mask[i];
1010     }
1011     // flip bits for "may not be used"
1012     packet_types ^= 0x3306;
1013     return packet_types;
1014 }
1015 
1016 uint16_t hci_usable_acl_packet_types(void){
1017     return hci_stack->packet_types;
1018 }
1019 #endif
1020 
1021 uint8_t* hci_get_outgoing_packet_buffer(void){
1022     // hci packet buffer is >= acl data packet length
1023     return hci_stack->hci_packet_buffer;
1024 }
1025 
1026 uint16_t hci_max_acl_data_packet_length(void){
1027     return hci_stack->acl_data_packet_length;
1028 }
1029 
1030 #ifdef ENABLE_CLASSIC
1031 int hci_extended_sco_link_supported(void){
1032     // No. 31, byte 3, bit 7
1033     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1034 }
1035 #endif
1036 
1037 int hci_non_flushable_packet_boundary_flag_supported(void){
1038     // No. 54, byte 6, bit 6
1039     return (hci_stack->local_supported_features[6u] & (1u << 6u)) != 0u;
1040 }
1041 
1042 static int gap_ssp_supported(void){
1043     // No. 51, byte 6, bit 3
1044     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1045 }
1046 
1047 static int hci_classic_supported(void){
1048 #ifdef ENABLE_CLASSIC
1049     // No. 37, byte 4, bit 5, = No BR/EDR Support
1050     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1051 #else
1052     return 0;
1053 #endif
1054 }
1055 
1056 static int hci_le_supported(void){
1057 #ifdef ENABLE_BLE
1058     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1059     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1060 #else
1061     return 0;
1062 #endif
1063 }
1064 
1065 #ifdef ENABLE_BLE
1066 
1067 /**
1068  * @brief Get addr type and address used for LE in Advertisements, Scan Responses,
1069  */
1070 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1071     *addr_type = hci_stack->le_own_addr_type;
1072     if (hci_stack->le_own_addr_type){
1073         (void)memcpy(addr, hci_stack->le_random_address, 6);
1074     } else {
1075         (void)memcpy(addr, hci_stack->local_bd_addr, 6);
1076     }
1077 }
1078 
1079 #ifdef ENABLE_LE_CENTRAL
1080 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1081 
1082     int offset = 3;
1083     int num_reports = packet[offset];
1084     offset += 1;
1085 
1086     int i;
1087     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1088     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1089     for (i=0; (i<num_reports) && (offset < size);i++){
1090         // sanity checks on data_length:
1091         uint8_t data_length = packet[offset + 8];
1092         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1093         if ((offset + 9u + data_length + 1u) > size)    return;
1094         // setup event
1095         uint8_t event_size = 10u + data_length;
1096         int pos = 0;
1097         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1098         event[pos++] = event_size;
1099         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1100         offset += 8;
1101         pos += 8;
1102         event[pos++] = packet[offset + 1 + data_length]; // rssi
1103         event[pos++] = data_length;
1104         offset++;
1105         (void)memcpy(&event[pos], &packet[offset], data_length);
1106         pos +=    data_length;
1107         offset += data_length + 1u; // rssi
1108         hci_emit_event(event, pos, 1);
1109     }
1110 }
1111 #endif
1112 #endif
1113 
1114 #ifdef ENABLE_BLE
1115 #ifdef ENABLE_LE_PERIPHERAL
1116 static void hci_update_advertisements_enabled_for_current_roles(void){
1117     if (hci_stack->le_advertisements_enabled){
1118         // get number of active le slave connections
1119         int num_slave_connections = 0;
1120         btstack_linked_list_iterator_t it;
1121         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1122         while (btstack_linked_list_iterator_has_next(&it)){
1123             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1124             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1125             if (con->state != OPEN) continue;
1126             if (con->role  != HCI_ROLE_SLAVE) continue;
1127             if (!hci_is_le_connection(con)) continue;
1128             num_slave_connections++;
1129         }
1130         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1131         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1132     } else {
1133         hci_stack->le_advertisements_enabled_for_current_roles = false;
1134     }
1135 }
1136 #endif
1137 #endif
1138 
1139 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1140 
1141 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1142     if (!hci_stack->config) return 0;
1143     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1144     // Limit baud rate for Broadcom chipsets to 3 mbps
1145     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1146         baud_rate = 3000000;
1147     }
1148     return baud_rate;
1149 }
1150 
1151 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1152     UNUSED(ds);
1153 
1154     switch (hci_stack->substate){
1155         case HCI_INIT_W4_SEND_RESET:
1156             log_info("Resend HCI Reset");
1157             hci_stack->substate = HCI_INIT_SEND_RESET;
1158             hci_stack->num_cmd_packets = 1;
1159             hci_run();
1160             break;
1161         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1162             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1163             if (hci_stack->hci_transport->reset_link){
1164                 hci_stack->hci_transport->reset_link();
1165             }
1166 
1167             /* fall through */
1168 
1169         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1170             log_info("Resend HCI Reset - CSR Warm Boot");
1171             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1172             hci_stack->num_cmd_packets = 1;
1173             hci_run();
1174             break;
1175         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1176             if (hci_stack->hci_transport->set_baudrate){
1177                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1178                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1179                 hci_stack->hci_transport->set_baudrate(baud_rate);
1180             }
1181             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1182             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1183                 if (hci_stack->hci_transport->reset_link){
1184                     log_info("Link Reset");
1185                     hci_stack->hci_transport->reset_link();
1186                 }
1187                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1188                 hci_run();
1189             }
1190             break;
1191         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1192             // otherwise continue
1193             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1194             hci_send_cmd(&hci_read_local_supported_commands);
1195             break;
1196         default:
1197             break;
1198     }
1199 }
1200 #endif
1201 
1202 static void hci_initializing_next_state(void){
1203     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1204 }
1205 
1206 // assumption: hci_can_send_command_packet_now() == true
1207 static void hci_initializing_run(void){
1208     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1209     switch (hci_stack->substate){
1210         case HCI_INIT_SEND_RESET:
1211             hci_state_reset();
1212 
1213 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1214             // prepare reset if command complete not received in 100ms
1215             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1216             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1217             btstack_run_loop_add_timer(&hci_stack->timeout);
1218 #endif
1219             // send command
1220             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1221             hci_send_cmd(&hci_reset);
1222             break;
1223         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1224             hci_send_cmd(&hci_read_local_version_information);
1225             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1226             break;
1227         case HCI_INIT_SEND_READ_LOCAL_NAME:
1228             hci_send_cmd(&hci_read_local_name);
1229             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1230             break;
1231 
1232 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1233         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1234             hci_state_reset();
1235             // prepare reset if command complete not received in 100ms
1236             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1237             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1238             btstack_run_loop_add_timer(&hci_stack->timeout);
1239             // send command
1240             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1241             hci_send_cmd(&hci_reset);
1242             break;
1243         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1244             hci_state_reset();
1245             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1246             hci_send_cmd(&hci_reset);
1247             break;
1248         case HCI_INIT_SEND_BAUD_CHANGE: {
1249             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1250             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1251             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1252             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1253             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1254             // STLC25000D: baudrate change happens within 0.5 s after command was send,
1255             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1256             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1257                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1258                 btstack_run_loop_add_timer(&hci_stack->timeout);
1259             }
1260             break;
1261         }
1262         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1263             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1264             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1265             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1266             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1267             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1268             break;
1269         }
1270         case HCI_INIT_CUSTOM_INIT:
1271             // Custom initialization
1272             if (hci_stack->chipset && hci_stack->chipset->next_command){
1273                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1274                 int send_cmd = 0;
1275                 switch (hci_stack->chipset_result){
1276                     case BTSTACK_CHIPSET_VALID_COMMAND:
1277                         send_cmd = 1;
1278                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1279                         break;
1280                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1281                         send_cmd = 1;
1282                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1283                         log_info("CSR Warm Boot");
1284                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1285                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1286                         btstack_run_loop_add_timer(&hci_stack->timeout);
1287                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1288                             && hci_stack->config
1289                             && hci_stack->chipset
1290                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1291                             && hci_stack->hci_transport->set_baudrate
1292                             && hci_transport_uart_get_main_baud_rate()){
1293                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1294                         } else {
1295                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1296                         }
1297                         break;
1298                     default:
1299                         break;
1300                 }
1301 
1302                 if (send_cmd){
1303                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1304                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1305                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1306                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1307                     break;
1308                 }
1309                 log_info("Init script done");
1310 
1311                 // Init script download on Broadcom chipsets causes:
1312                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1313                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1314                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1315 
1316                     // - baud rate to reset, restore UART baud rate if needed
1317                     int need_baud_change = hci_stack->config
1318                         && hci_stack->chipset
1319                         && hci_stack->chipset->set_baudrate_command
1320                         && hci_stack->hci_transport->set_baudrate
1321                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1322                     if (need_baud_change) {
1323                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1324                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1325                         hci_stack->hci_transport->set_baudrate(baud_rate);
1326                     }
1327 
1328                     uint16_t bcm_delay_ms = 300;
1329                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1330                     //   -> Work around: wait here.
1331                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1332                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1333                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1334                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1335                     btstack_run_loop_add_timer(&hci_stack->timeout);
1336                     break;
1337                 }
1338             }
1339             // otherwise continue
1340             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1341             hci_send_cmd(&hci_read_local_supported_commands);
1342             break;
1343         case HCI_INIT_SET_BD_ADDR:
1344             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1345             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1346             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1347             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1348             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1349             break;
1350 #endif
1351 
1352         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1353             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1354             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1355             hci_send_cmd(&hci_read_local_supported_commands);
1356             break;
1357         case HCI_INIT_READ_BD_ADDR:
1358             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1359             hci_send_cmd(&hci_read_bd_addr);
1360             break;
1361         case HCI_INIT_READ_BUFFER_SIZE:
1362             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1363             hci_send_cmd(&hci_read_buffer_size);
1364             break;
1365         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1366             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1367             hci_send_cmd(&hci_read_local_supported_features);
1368             break;
1369 
1370 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1371         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1372             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1373             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1374             break;
1375         case HCI_INIT_HOST_BUFFER_SIZE:
1376             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1377             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1378                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1379             break;
1380 #endif
1381 
1382         case HCI_INIT_SET_EVENT_MASK:
1383             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1384             if (hci_le_supported()){
1385                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1386             } else {
1387                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1388                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1389             }
1390             break;
1391 
1392 #ifdef ENABLE_CLASSIC
1393         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1394             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1395             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1396             break;
1397         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1398             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1399             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1400             break;
1401         case HCI_INIT_WRITE_DEFAULT_LINK_POLICY_SETTING:
1402             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_LINK_POLICY_SETTING;
1403             hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1404             break;
1405         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1406             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1407             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1408             break;
1409         case HCI_INIT_WRITE_LOCAL_NAME: {
1410             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1411             hci_reserve_packet_buffer();
1412             uint8_t * packet = hci_stack->hci_packet_buffer;
1413             // construct HCI Command and send
1414             uint16_t opcode = hci_write_local_name.opcode;
1415             hci_stack->last_cmd_opcode = opcode;
1416             packet[0] = opcode & 0xff;
1417             packet[1] = opcode >> 8;
1418             packet[2] = DEVICE_NAME_LEN;
1419             memset(&packet[3], 0, DEVICE_NAME_LEN);
1420             uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1421             uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1422             // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1423             (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1424             // expand '00:00:00:00:00:00' in name with bd_addr
1425             btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1426             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1427             break;
1428         }
1429         case HCI_INIT_WRITE_EIR_DATA: {
1430             hci_stack->substate = HCI_INIT_W4_WRITE_EIR_DATA;
1431             hci_reserve_packet_buffer();
1432             uint8_t * packet = hci_stack->hci_packet_buffer;
1433             // construct HCI Command in-place and send
1434             uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1435             hci_stack->last_cmd_opcode = opcode;
1436             uint16_t offset = 0;
1437             packet[offset++] = opcode & 0xff;
1438             packet[offset++] = opcode >> 8;
1439             packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1440             packet[offset++] = 0;  // FEC not required
1441             memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1442             if (hci_stack->eir_data){
1443                 // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1444                 ad_context_t context;
1445                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1446                     uint8_t data_type   = ad_iterator_get_data_type(&context);
1447                     uint8_t size        = ad_iterator_get_data_len(&context);
1448                     const uint8_t *data = ad_iterator_get_data(&context);
1449                     // copy item
1450                     packet[offset++] = size + 1;
1451                     packet[offset++] = data_type;
1452                     memcpy(&packet[offset], data, size);
1453                     // update name item
1454                     if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1455                         btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1456                     }
1457                     offset += size;
1458                 }
1459             } else {
1460                 uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1461                 uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1462                 packet[offset++] = bytes_to_copy + 1;
1463                 packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1464                 (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1465                 // expand '00:00:00:00:00:00' in name with bd_addr
1466                 btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1467             }
1468             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1469             break;
1470         }
1471         case HCI_INIT_WRITE_INQUIRY_MODE:
1472             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1473             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1474             break;
1475         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1476             hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1477             hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1478             break;
1479         case HCI_INIT_WRITE_SCAN_ENABLE:
1480             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1481             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1482             break;
1483         // only sent if ENABLE_SCO_OVER_HCI is defined
1484         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1485             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1486             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1487             break;
1488         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1489             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1490             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1491             break;
1492         // only sent if ENABLE_SCO_OVER_HCI and manufacturer is Broadcom
1493         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1494             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1495             log_info("BCM: Route SCO data via HCI transport");
1496             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1497             break;
1498 
1499 #endif
1500 #ifdef ENABLE_BLE
1501         // LE INIT
1502         case HCI_INIT_LE_READ_BUFFER_SIZE:
1503             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1504             hci_send_cmd(&hci_le_read_buffer_size);
1505             break;
1506         case HCI_INIT_LE_SET_EVENT_MASK:
1507             hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1508             hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1509             break;
1510         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1511             // LE Supported Host = 1, Simultaneous Host = 0
1512             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1513             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1514             break;
1515 #endif
1516 
1517 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1518         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1519             hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1520             hci_send_cmd(&hci_le_read_maximum_data_length);
1521             break;
1522         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1523             hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1524             hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1525             break;
1526 #endif
1527 
1528 #ifdef ENABLE_LE_CENTRAL
1529         case HCI_INIT_READ_WHITE_LIST_SIZE:
1530             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1531             hci_send_cmd(&hci_le_read_white_list_size);
1532             break;
1533         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1534             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, own address type, accept all advs
1535             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1536             hci_send_cmd(&hci_le_set_scan_parameters, 1, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->le_own_addr_type, 0);
1537             break;
1538 #endif
1539         default:
1540             return;
1541     }
1542 }
1543 
1544 static void hci_init_done(void){
1545     // done. tell the app
1546     log_info("hci_init_done -> HCI_STATE_WORKING");
1547     hci_stack->state = HCI_STATE_WORKING;
1548     hci_emit_state();
1549     hci_run();
1550 }
1551 
1552 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1553     bool command_completed = false;
1554     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1555         uint16_t opcode = little_endian_read_16(packet,3);
1556         if (opcode == hci_stack->last_cmd_opcode){
1557             command_completed = true;
1558             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1559         } else {
1560             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1561         }
1562     }
1563 
1564     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1565         uint8_t  status = packet[2];
1566         uint16_t opcode = little_endian_read_16(packet,4);
1567         if (opcode == hci_stack->last_cmd_opcode){
1568             if (status){
1569                 command_completed = true;
1570                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1571             } else {
1572                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1573             }
1574         } else {
1575             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1576         }
1577     }
1578 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1579     // Vendor == CSR
1580     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1581         // TODO: track actual command
1582         command_completed = true;
1583     }
1584 
1585     // Vendor == Toshiba
1586     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1587         // TODO: track actual command
1588         command_completed = true;
1589         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1590         hci_stack->num_cmd_packets = 1;
1591     }
1592 #endif
1593 
1594     return command_completed;
1595 }
1596 
1597 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1598 
1599     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1600 
1601     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1602 
1603 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1604 
1605     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1606     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1607     //
1608     // HCI Reset
1609     // Timeout 100 ms
1610     // HCI Reset
1611     // Command Complete Reset
1612     // HCI Read Local Version Information
1613     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1614     // hang...
1615     //
1616     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1617     if (!command_completed
1618             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1619             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1620 
1621         uint16_t opcode = little_endian_read_16(packet,3);
1622         if (opcode == hci_reset.opcode){
1623             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1624             return;
1625         }
1626     }
1627 
1628     // CSR & H5
1629     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1630     if (!command_completed
1631             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1632             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1633 
1634         uint16_t opcode = little_endian_read_16(packet,3);
1635         if (opcode == hci_reset.opcode){
1636             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1637             return;
1638         }
1639     }
1640 
1641     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1642     // fix: Correct substate and behave as command below
1643     if (command_completed){
1644         switch (hci_stack->substate){
1645             case HCI_INIT_SEND_RESET:
1646                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1647                 break;
1648             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1649                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1650                 break;
1651             default:
1652                 break;
1653         }
1654     }
1655 
1656 #endif
1657 
1658     if (!command_completed) return;
1659 
1660     bool need_baud_change = false;
1661     bool need_addr_change = false;
1662 
1663 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1664     need_baud_change = hci_stack->config
1665                         && hci_stack->chipset
1666                         && hci_stack->chipset->set_baudrate_command
1667                         && hci_stack->hci_transport->set_baudrate
1668                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1669 
1670     need_addr_change = hci_stack->custom_bd_addr_set
1671                         && hci_stack->chipset
1672                         && hci_stack->chipset->set_bd_addr_command;
1673 #endif
1674 
1675     switch(hci_stack->substate){
1676 
1677 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1678         case HCI_INIT_SEND_RESET:
1679             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1680             // fix: just correct substate and behave as command below
1681             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1682             btstack_run_loop_remove_timer(&hci_stack->timeout);
1683             break;
1684         case HCI_INIT_W4_SEND_RESET:
1685             btstack_run_loop_remove_timer(&hci_stack->timeout);
1686             break;
1687         case HCI_INIT_W4_SEND_READ_LOCAL_NAME:
1688             log_info("Received local name, need baud change %d", (int) need_baud_change);
1689             if (need_baud_change){
1690                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1691                 return;
1692             }
1693             // skip baud change
1694             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1695             return;
1696         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1697             // for STLC2500D, baud rate change already happened.
1698             // for others, baud rate gets changed now
1699             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1700                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1701                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1702                 hci_stack->hci_transport->set_baudrate(baud_rate);
1703             }
1704             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1705             return;
1706         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1707             btstack_run_loop_remove_timer(&hci_stack->timeout);
1708             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1709             return;
1710         case HCI_INIT_W4_CUSTOM_INIT:
1711             // repeat custom init
1712             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1713             return;
1714 #else
1715         case HCI_INIT_W4_SEND_RESET:
1716             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1717             return ;
1718 #endif
1719 
1720         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1721             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1722               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1723                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1724                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1725                 return;
1726             }
1727             if (need_addr_change){
1728                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1729                 return;
1730             }
1731             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1732             return;
1733 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1734         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1735             if (need_baud_change){
1736                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1737                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
1738                 hci_stack->hci_transport->set_baudrate(baud_rate);
1739             }
1740             if (need_addr_change){
1741                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1742                 return;
1743             }
1744             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1745             return;
1746         case HCI_INIT_W4_SET_BD_ADDR:
1747             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1748             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1749             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1750                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1751                 return;
1752             }
1753             // skipping st warm boot
1754             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1755             return;
1756         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1757             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1758             return;
1759 #endif
1760         case HCI_INIT_W4_READ_BD_ADDR:
1761             // only read buffer size if supported
1762             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1763                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1764                 return;
1765             }
1766             // skipping read buffer size
1767             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1768             return;
1769         case HCI_INIT_W4_SET_EVENT_MASK:
1770             // skip Classic init commands for LE only chipsets
1771             if (!hci_classic_supported()){
1772 #ifdef ENABLE_BLE
1773                 if (hci_le_supported()){
1774                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1775                     return;
1776                 }
1777 #endif
1778                 log_error("Neither BR/EDR nor LE supported");
1779                 hci_init_done();
1780                 return;
1781             }
1782             if (!gap_ssp_supported()){
1783                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1784                 return;
1785             }
1786             break;
1787 #ifdef ENABLE_BLE
1788         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1789             // skip write le host if not supported (e.g. on LE only EM9301)
1790             if (hci_stack->local_supported_commands[0u] & 0x02u) break;
1791             hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1792             return;
1793 
1794 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1795         case HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED:
1796             log_info("Supported commands %x", hci_stack->local_supported_commands[0] & 0x30);
1797             if ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u){
1798                 hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1799                 return;
1800             }
1801             // explicit fall through to reduce repetitions
1802 
1803 #ifdef ENABLE_LE_CENTRAL
1804             hci_stack->substate = HCI_INIT_READ_WHITE_LIST_SIZE;
1805 #else
1806             hci_init_done();
1807 #endif
1808             return;
1809 #endif  /* ENABLE_LE_DATA_LENGTH_EXTENSION */
1810 
1811 #endif  /* ENABLE_BLE */
1812 
1813         case HCI_INIT_W4_WRITE_INQUIRY_MODE:
1814             // skip write secure connections host support if not supported or disabled
1815             if (!hci_stack->secure_connections_enable || (hci_stack->local_supported_commands[1u] & 0x02u) == 0u) {
1816                 hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;
1817                 return;
1818             }
1819             break;
1820 
1821 #ifdef ENABLE_SCO_OVER_HCI
1822         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1823             // skip write synchronous flow control if not supported
1824             if (hci_stack->local_supported_commands[0] & 0x04) break;
1825             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1826 
1827             /* fall through */
1828 
1829         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1830             // skip write default erroneous data reporting if not supported
1831             if (hci_stack->local_supported_commands[0] & 0x08) break;
1832             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1833 
1834             /* fall through */
1835 
1836         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1837             // skip bcm set sco pcm config on non-Broadcom chipsets
1838             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) break;
1839             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1840 
1841             /* fall through */
1842 
1843         case HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT:
1844             if (!hci_le_supported()){
1845                 // SKIP LE init for Classic only configuration
1846                 hci_init_done();
1847                 return;
1848             }
1849             break;
1850 
1851 #else /* !ENABLE_SCO_OVER_HCI */
1852 
1853         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1854 #ifdef ENABLE_BLE
1855             if (hci_le_supported()){
1856                 hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE;
1857                 return;
1858             }
1859 #endif
1860             // SKIP LE init for Classic only configuration
1861             hci_init_done();
1862             return;
1863 #endif /* ENABLE_SCO_OVER_HCI */
1864 
1865 // avoid compile error due to duplicate cases: HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT == HCI_INIT_DONE-1
1866 #if defined(ENABLE_BLE) || defined(ENABLE_LE_DATA_LENGTH_EXTENSION) || defined(ENABLE_LE_CENTRAL)
1867         // Response to command before init done state -> init done
1868         case (HCI_INIT_DONE-1):
1869             hci_init_done();
1870             return;
1871 #endif
1872 
1873         default:
1874             break;
1875     }
1876     hci_initializing_next_state();
1877 }
1878 
1879 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
1880     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
1881     bd_addr_t bd_address;
1882     (void)memcpy(&bd_address, conn->address, 6);
1883 
1884 #ifdef ENABLE_CLASSIC
1885     // cache needed data
1886     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1887 #endif
1888 
1889     // connection failed, remove entry
1890     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1891     btstack_memory_hci_connection_free( conn );
1892 
1893 #ifdef ENABLE_CLASSIC
1894     // notify client if dedicated bonding
1895     if (notify_dedicated_bonding_failed){
1896         log_info("hci notify_dedicated_bonding_failed");
1897         hci_emit_dedicated_bonding_result(bd_address, status);
1898     }
1899 
1900     // if authentication error, also delete link key
1901     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
1902         gap_drop_link_key_for_bd_addr(bd_address);
1903     }
1904 #else
1905     UNUSED(status);
1906 #endif
1907 }
1908 
1909 #ifdef ENABLE_CLASSIC
1910 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
1911     // SSP Controller
1912     if (features[6] & (1 << 3)){
1913         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
1914     }
1915     // eSCO
1916     if (features[3] & (1<<7)){
1917         conn->remote_supported_features[0] |= 1;
1918     }
1919     // Extended features
1920     if (features[7] & (1<<7)){
1921         conn->remote_supported_features[0] |= 2;
1922     }
1923 }
1924 
1925 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
1926     // SSP Host
1927     if (features[0] & (1 << 0)){
1928         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
1929     }
1930     // SC Host
1931     if (features[0] & (1 << 3)){
1932         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
1933     }
1934 }
1935 
1936 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
1937     // SC Controller
1938     if (features[1] & (1 << 0)){
1939         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
1940     }
1941 }
1942 
1943 static void hci_handle_remote_features_received(hci_connection_t * conn){
1944     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1945     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
1946     if (conn->bonding_flags & BONDING_DEDICATED){
1947         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1948     }
1949 }
1950 #endif
1951 
1952 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
1953     // handle BT initialization
1954     if (hci_stack->state == HCI_STATE_INITIALIZING) {
1955         hci_initializing_event_handler(packet, size);
1956     }
1957 
1958     // help with BT sleep
1959     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
1960         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
1961         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
1962         hci_initializing_next_state();
1963     }
1964 }
1965 
1966 #ifdef ENABLE_CLASSIC
1967 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
1968     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1969     conn->encryption_key_size = encryption_key_size;
1970 
1971     if ((conn->authentication_flags & CONNECTION_AUTHENTICATED) != 0) {
1972         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
1973         return;
1974     }
1975 
1976     // Request Authentication if not already done
1977     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
1978     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1979 }
1980 #endif
1981 
1982 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
1983     UNUSED(size);
1984 
1985     uint16_t manufacturer;
1986 #ifdef ENABLE_CLASSIC
1987     hci_con_handle_t handle;
1988     hci_connection_t * conn;
1989     uint8_t status;
1990 #endif
1991     // get num cmd packets - limit to 1 to reduce complexity
1992     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
1993 
1994     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
1995     switch (opcode){
1996         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
1997             if (packet[5]) break;
1998             // terminate, name 248 chars
1999             packet[6+248] = 0;
2000             log_info("local name: %s", &packet[6]);
2001             break;
2002         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2003             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2004             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2005                 uint16_t acl_len = little_endian_read_16(packet, 6);
2006                 uint16_t sco_len = packet[8];
2007 
2008                 // determine usable ACL/SCO payload size
2009                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2010                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2011 
2012                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2013                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2014 
2015                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2016                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2017                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2018             }
2019             break;
2020         case HCI_OPCODE_HCI_READ_RSSI:
2021             if (packet[5] == ERROR_CODE_SUCCESS){
2022                 uint8_t event[5];
2023                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2024                 event[1] = 3;
2025                 (void)memcpy(&event[2], &packet[6], 3);
2026                 hci_emit_event(event, sizeof(event), 1);
2027             }
2028             break;
2029 #ifdef ENABLE_BLE
2030         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2031             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2032             hci_stack->le_acl_packets_total_num = packet[8];
2033             // determine usable ACL payload size
2034             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2035                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2036             }
2037             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2038             break;
2039 #endif
2040 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2041         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2042             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2043             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2044             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);
2045             break;
2046 #endif
2047 #ifdef ENABLE_LE_CENTRAL
2048         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2049             hci_stack->le_whitelist_capacity = packet[6];
2050             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2051             break;
2052 #endif
2053         case HCI_OPCODE_HCI_READ_BD_ADDR:
2054             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2055             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));
2056 #ifdef ENABLE_CLASSIC
2057             if (hci_stack->link_key_db){
2058                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2059             }
2060 #endif
2061             break;
2062 #ifdef ENABLE_CLASSIC
2063         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2064             hci_emit_discoverable_enabled(hci_stack->discoverable);
2065             break;
2066         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2067             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2068                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2069                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2070                 hci_emit_event(event, sizeof(event), 1);
2071             }
2072             break;
2073 #endif
2074         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2075             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2076 
2077 #ifdef ENABLE_CLASSIC
2078             // determine usable ACL packet types based on host buffer size and supported features
2079             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2080             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2081 #endif
2082             // Classic/LE
2083             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2084             break;
2085         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2086             manufacturer = little_endian_read_16(packet, 10);
2087             // map Cypress to Broadcom
2088             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2089                 log_info("Treat Cypress as Broadcom");
2090                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2091                 little_endian_store_16(packet, 10, manufacturer);
2092             }
2093             hci_stack->manufacturer = manufacturer;
2094             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2095             break;
2096         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2097             hci_stack->local_supported_commands[0] =
2098                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit 0 = Octet 14, bit 7 / Read Buffer Size
2099                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit 1 = Octet 24, bit 6 / Write Le Host Supported
2100                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit 2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2101                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     ) |  // bit 3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2102                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit 4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2103                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit 5 = Octet 35, bit 3 / LE Read Maximum Data Length
2104                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit 6 = Octet 35, bit 5 / LE Set Default PHY
2105                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit 7 = Octet 20, bit 4 / Read Encryption Key Size
2106             hci_stack->local_supported_commands[1] =
2107                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit 8 = Octet  2, bit 6 / Read Remote Extended Features
2108                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u);   // bit 9 = Octet 32, bit 3 / Write Secure Connections Host
2109             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2110             break;
2111 #ifdef ENABLE_CLASSIC
2112         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2113             if (packet[5]) return;
2114             hci_stack->synchronous_flow_control_enabled = 1;
2115             break;
2116         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2117             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2118             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2119             conn   = hci_connection_for_handle(handle);
2120             if (conn != NULL) {
2121                 uint8_t key_size = 0;
2122                 if (status == 0){
2123                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2124                     log_info("Handle %04x key Size: %u", handle, key_size);
2125                 } else {
2126                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2127                 }
2128                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2129             }
2130             break;
2131 #endif
2132         default:
2133             break;
2134     }
2135 }
2136 
2137 static void event_handler(uint8_t *packet, uint16_t size){
2138 
2139     uint16_t event_length = packet[1];
2140 
2141     // assert packet is complete
2142     if (size != (event_length + 2u)){
2143         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2144         return;
2145     }
2146 
2147     bd_addr_t addr;
2148     bd_addr_type_t addr_type;
2149     hci_con_handle_t handle;
2150     hci_connection_t * conn;
2151     int i;
2152     int create_connection_cmd;
2153 
2154 #ifdef ENABLE_CLASSIC
2155     uint8_t link_type;
2156 #endif
2157 
2158     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2159 
2160     switch (hci_event_packet_get_type(packet)) {
2161 
2162         case HCI_EVENT_COMMAND_COMPLETE:
2163             handle_command_complete_event(packet, size);
2164             break;
2165 
2166         case HCI_EVENT_COMMAND_STATUS:
2167             // get num cmd packets - limit to 1 to reduce complexity
2168             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2169 
2170             // check command status to detected failed outgoing connections
2171             create_connection_cmd = 0;
2172 #ifdef ENABLE_CLASSIC
2173             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2174                 create_connection_cmd = 1;
2175             }
2176 #endif
2177 #ifdef ENABLE_LE_CENTRAL
2178             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2179                 create_connection_cmd = 1;
2180             }
2181 #endif
2182             if (create_connection_cmd) {
2183                 uint8_t status = hci_event_command_status_get_status(packet);
2184                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, hci_stack->outgoing_addr_type);
2185                 log_info("command status (create connection), status %x, connection %p, addr %s, type %x", status, conn, bd_addr_to_str(hci_stack->outgoing_addr), hci_stack->outgoing_addr_type);
2186 
2187                 // reset outgoing address info
2188                 memset(hci_stack->outgoing_addr, 0, 6);
2189                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2190 
2191                 // error => outgoing connection failed
2192                 if ((conn != NULL) && (status != 0u)){
2193                     hci_handle_connection_failed(conn, status);
2194                 }
2195             }
2196             break;
2197 
2198         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2199             if (size < 3) return;
2200             uint16_t num_handles = packet[2];
2201             if (size != (3u + num_handles * 4u)) return;
2202             uint16_t offset = 3;
2203             for (i=0; i<num_handles;i++){
2204                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2205                 offset += 2u;
2206                 uint16_t num_packets = little_endian_read_16(packet, offset);
2207                 offset += 2u;
2208 
2209                 conn = hci_connection_for_handle(handle);
2210                 if (!conn){
2211                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2212                     continue;
2213                 }
2214 
2215                 if (conn->num_packets_sent >= num_packets){
2216                     conn->num_packets_sent -= num_packets;
2217                 } else {
2218                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2219                     conn->num_packets_sent = 0;
2220                 }
2221                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2222 
2223 #ifdef ENABLE_CLASSIC
2224                 // For SCO, we do the can_send_now_check here
2225                 hci_notify_if_sco_can_send_now();
2226 #endif
2227             }
2228             break;
2229         }
2230 
2231 #ifdef ENABLE_CLASSIC
2232         case HCI_EVENT_INQUIRY_COMPLETE:
2233             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2234                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2235                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2236                 hci_emit_event(event, sizeof(event), 1);
2237             }
2238             break;
2239         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2240             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2241                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2242             }
2243             break;
2244         case HCI_EVENT_CONNECTION_REQUEST:
2245             reverse_bd_addr(&packet[2], addr);
2246             if (hci_stack->gap_classic_accept_callback != NULL){
2247                 if ((*hci_stack->gap_classic_accept_callback)(addr) == 0){
2248                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2249                     bd_addr_copy(hci_stack->decline_addr, addr);
2250                     break;
2251                 }
2252             }
2253 
2254             // TODO: eval COD 8-10
2255             link_type = packet[11];
2256             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
2257             addr_type = (link_type == 1) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2258             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2259             if (!conn) {
2260                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2261             }
2262             if (!conn) {
2263                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2264                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2265                 bd_addr_copy(hci_stack->decline_addr, addr);
2266                 break;
2267             }
2268             conn->role  = HCI_ROLE_SLAVE;
2269             conn->state = RECEIVED_CONNECTION_REQUEST;
2270             // store info about eSCO
2271             if (link_type == 0x02){
2272                 conn->remote_supported_features[0] |= 1;
2273             }
2274             hci_run();
2275             break;
2276 
2277         case HCI_EVENT_CONNECTION_COMPLETE:
2278             // Connection management
2279             reverse_bd_addr(&packet[5], addr);
2280             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2281             addr_type = BD_ADDR_TYPE_ACL;
2282             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2283             if (conn) {
2284                 if (!packet[2]){
2285                     conn->state = OPEN;
2286                     conn->con_handle = little_endian_read_16(packet, 3);
2287 
2288                     // queue get remote feature
2289                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2290 
2291                     // queue set supervision timeout if we're master
2292                     if ((hci_stack->link_supervision_timeout != 0) && (conn->role == HCI_ROLE_MASTER)){
2293                         connectionSetAuthenticationFlags(conn, WRITE_SUPERVISION_TIMEOUT);
2294                     }
2295 
2296                     // restart timer
2297                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2298                     btstack_run_loop_add_timer(&conn->timeout);
2299 
2300                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2301 
2302                     hci_emit_nr_connections_changed();
2303                 } else {
2304                     // connection failed
2305                     hci_handle_connection_failed(conn, packet[2]);
2306                 }
2307             }
2308             break;
2309 
2310         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2311             reverse_bd_addr(&packet[5], addr);
2312             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2313             if (packet[2]){
2314                 // connection failed
2315                 break;
2316             }
2317             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2318             if (!conn) {
2319                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2320             }
2321             if (!conn) {
2322                 break;
2323             }
2324             conn->state = OPEN;
2325             conn->con_handle = little_endian_read_16(packet, 3);
2326 
2327 #ifdef ENABLE_SCO_OVER_HCI
2328             // update SCO
2329             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2330                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2331             }
2332             // trigger can send now
2333             if (hci_have_usb_transport()){
2334                 hci_stack->sco_can_send_now = 1;
2335             }
2336 #endif
2337             break;
2338 
2339         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2340             handle = little_endian_read_16(packet, 3);
2341             conn = hci_connection_for_handle(handle);
2342             if (!conn) break;
2343             if (!packet[2]){
2344                 const uint8_t * features = &packet[5];
2345                 hci_handle_remote_features_page_0(conn, features);
2346 
2347                 // read extended features if possible
2348                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2349                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2350                     break;
2351                 }
2352             }
2353             hci_handle_remote_features_received(conn);
2354             break;
2355 
2356         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2357             handle = little_endian_read_16(packet, 3);
2358             conn = hci_connection_for_handle(handle);
2359             if (!conn) break;
2360             // status = ok, page = 1
2361             if (!packet[2]) {
2362                 uint8_t page_number = packet[5];
2363                 uint8_t maximum_page_number = packet[6];
2364                 const uint8_t * features = &packet[7];
2365                 bool done = false;
2366                 switch (page_number){
2367                     case 1:
2368                         hci_handle_remote_features_page_1(conn, features);
2369                         if (maximum_page_number >= 2){
2370                             // get Secure Connections (Controller) from Page 2 if available
2371                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2372                         } else {
2373                             // otherwise, assume SC (Controller) == SC (Host)
2374                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2375                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2376                             }
2377                             done = true;
2378                         }
2379                         break;
2380                     case 2:
2381                         hci_handle_remote_features_page_2(conn, features);
2382                         done = true;
2383                         break;
2384                     default:
2385                         break;
2386                 }
2387                 if (!done) break;
2388             }
2389             hci_handle_remote_features_received(conn);
2390             break;
2391 
2392         case HCI_EVENT_LINK_KEY_REQUEST:
2393             log_info("HCI_EVENT_LINK_KEY_REQUEST");
2394             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
2395             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
2396             if (hci_stack->bondable && !hci_stack->link_key_db) break;
2397             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
2398             hci_run();
2399             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
2400             return;
2401 
2402         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2403             reverse_bd_addr(&packet[2], addr);
2404             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2405             if (!conn) break;
2406             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
2407             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2408             // Change Connection Encryption keeps link key type
2409             if (link_key_type != CHANGED_COMBINATION_KEY){
2410                 conn->link_key_type = link_key_type;
2411             }
2412             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2413             // still forward event to allow dismiss of pairing dialog
2414             break;
2415         }
2416 
2417         case HCI_EVENT_PIN_CODE_REQUEST:
2418             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
2419             // non-bondable mode: pin code negative reply will be sent
2420             if (!hci_stack->bondable){
2421                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
2422                 hci_run();
2423                 return;
2424             }
2425             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
2426             if (!hci_stack->link_key_db) break;
2427             hci_event_pin_code_request_get_bd_addr(packet, addr);
2428             hci_stack->link_key_db->delete_link_key(addr);
2429             break;
2430 
2431         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2432             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
2433             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
2434             break;
2435 
2436         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2437             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2438             if (!hci_stack->ssp_auto_accept) break;
2439             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
2440             break;
2441 
2442         case HCI_EVENT_USER_PASSKEY_REQUEST:
2443             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2444             if (!hci_stack->ssp_auto_accept) break;
2445             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
2446             break;
2447         case HCI_EVENT_MODE_CHANGE:
2448             handle = hci_event_mode_change_get_handle(packet);
2449             conn = hci_connection_for_handle(handle);
2450             if (!conn) break;
2451             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2452             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2453             break;
2454 #endif
2455 
2456         case HCI_EVENT_ENCRYPTION_CHANGE:
2457             handle = hci_event_encryption_change_get_connection_handle(packet);
2458             conn = hci_connection_for_handle(handle);
2459             if (!conn) break;
2460             if (hci_event_encryption_change_get_status(packet) == 0u) {
2461                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2462                 if (encryption_enabled){
2463                     if (hci_is_le_connection(conn)){
2464                         // For LE, we accept connection as encrypted
2465                         conn->authentication_flags |= CONNECTION_ENCRYPTED;
2466                     }
2467 #ifdef ENABLE_CLASSIC
2468                     else {
2469                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
2470                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
2471                         bool connected_uses_aes_ccm = encryption_enabled == 2;
2472                         if (sc_used_during_pairing && !connected_uses_aes_ccm){
2473                             log_info("SC during pairing, but only E0 now -> abort");
2474                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2475                             break;
2476                         }
2477 
2478                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
2479                         if (connected_uses_aes_ccm){
2480                             conn->authentication_flags |= CONNECTION_AUTHENTICATED;
2481                         }
2482 
2483                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
2484                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
2485                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
2486                         } else {
2487                             // if not, pretend everything is perfect
2488                             hci_handle_read_encryption_key_size_complete(conn, 16);
2489                         }
2490                     }
2491 #endif
2492                 } else {
2493                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
2494                 }
2495             }
2496 
2497             break;
2498 
2499 #ifdef ENABLE_CLASSIC
2500         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
2501             handle = hci_event_authentication_complete_get_connection_handle(packet);
2502             conn = hci_connection_for_handle(handle);
2503             if (!conn) break;
2504 
2505             // ignore authentication event if we didn't request it
2506             if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) == 0) break;
2507 
2508             // dedicated bonding: send result and disconnect
2509             if (conn->bonding_flags & BONDING_DEDICATED){
2510                 conn->bonding_flags &= ~BONDING_DEDICATED;
2511                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
2512                 conn->bonding_status = packet[2];
2513                 break;
2514             }
2515 
2516             // authenticated only if auth status == 0
2517             if (hci_event_authentication_complete_get_status(packet) == 0){
2518                 // authenticated
2519                 conn->authentication_flags |= CONNECTION_AUTHENTICATED;
2520 
2521                 // If link key sufficient for requested security and not already encrypted, start encryption
2522                 if (((gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level)) &&
2523                     ((conn->authentication_flags & CONNECTION_ENCRYPTED) == 0)){
2524                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2525                     break;
2526                 }
2527             }
2528 
2529             // emit updated security level
2530             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
2531             break;
2532 #endif
2533 
2534         // HCI_EVENT_DISCONNECTION_COMPLETE
2535         // has been split, to first notify stack before shutting connection down
2536         // see end of function, too.
2537         case HCI_EVENT_DISCONNECTION_COMPLETE:
2538             if (packet[2]) break;   // status != 0
2539             handle = little_endian_read_16(packet, 3);
2540             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
2541             if (hci_stack->acl_fragmentation_total_size > 0u) {
2542                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
2543                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
2544                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
2545                     hci_stack->acl_fragmentation_total_size = 0;
2546                     hci_stack->acl_fragmentation_pos = 0;
2547                     if (release_buffer){
2548                         hci_release_packet_buffer();
2549                     }
2550                 }
2551             }
2552 
2553             conn = hci_connection_for_handle(handle);
2554             if (!conn) break;
2555             // mark connection for shutdown
2556             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
2557 
2558             // emit dedicatd bonding event
2559             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
2560                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
2561             }
2562 
2563 #ifdef ENABLE_BLE
2564 #ifdef ENABLE_LE_PERIPHERAL
2565             // re-enable advertisements for le connections if active
2566             if (hci_is_le_connection(conn)){
2567                 hci_update_advertisements_enabled_for_current_roles();
2568             }
2569 #endif
2570 #endif
2571             break;
2572 
2573         case HCI_EVENT_HARDWARE_ERROR:
2574             log_error("Hardware Error: 0x%02x", packet[2]);
2575             if (hci_stack->hardware_error_callback){
2576                 (*hci_stack->hardware_error_callback)(packet[2]);
2577             } else {
2578                 // if no special requests, just reboot stack
2579                 hci_power_control_off();
2580                 hci_power_control_on();
2581             }
2582             break;
2583 
2584 #ifdef ENABLE_CLASSIC
2585         case HCI_EVENT_ROLE_CHANGE:
2586             if (packet[2]) break;   // status != 0
2587             reverse_bd_addr(&packet[3], addr);
2588             addr_type = BD_ADDR_TYPE_ACL;
2589             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2590             if (!conn) break;
2591             conn->role = packet[9];
2592             break;
2593 #endif
2594 
2595         case HCI_EVENT_TRANSPORT_PACKET_SENT:
2596             // release packet buffer only for asynchronous transport and if there are not further fragements
2597             if (hci_transport_synchronous()) {
2598                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
2599                 return; // instead of break: to avoid re-entering hci_run()
2600             }
2601             hci_stack->acl_fragmentation_tx_active = 0;
2602             if (hci_stack->acl_fragmentation_total_size) break;
2603             hci_release_packet_buffer();
2604 
2605             // L2CAP receives this event via the hci_emit_event below
2606 
2607 #ifdef ENABLE_CLASSIC
2608             // For SCO, we do the can_send_now_check here
2609             hci_notify_if_sco_can_send_now();
2610 #endif
2611             break;
2612 
2613 #ifdef ENABLE_CLASSIC
2614         case HCI_EVENT_SCO_CAN_SEND_NOW:
2615             // For SCO, we do the can_send_now_check here
2616             hci_stack->sco_can_send_now = 1;
2617             hci_notify_if_sco_can_send_now();
2618             return;
2619 
2620         // explode inquriy results for easier consumption
2621         case HCI_EVENT_INQUIRY_RESULT:
2622         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
2623         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
2624             gap_inquiry_explode(packet, size);
2625             break;
2626 #endif
2627 
2628 #ifdef ENABLE_BLE
2629         case HCI_EVENT_LE_META:
2630             switch (packet[2]){
2631 #ifdef ENABLE_LE_CENTRAL
2632                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
2633                     // log_info("advertising report received");
2634                     if (!hci_stack->le_scanning_enabled) break;
2635                     le_handle_advertisement_report(packet, size);
2636                     break;
2637 #endif
2638                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
2639                     // Connection management
2640                     reverse_bd_addr(&packet[8], addr);
2641                     addr_type = (bd_addr_type_t)packet[7];
2642                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2643                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2644 
2645 #ifdef ENABLE_LE_CENTRAL
2646                     // if auto-connect, remove from whitelist in both roles
2647                     if (hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST){
2648                         hci_whitelist_remove(addr_type, addr);
2649                     }
2650                     // handle error: error is reported only to the initiator -> outgoing connection
2651                     if (packet[3]){
2652 
2653                         // handle cancelled outgoing connection
2654                         // "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2655                         //  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2656                         //  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2657                         if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2658                             conn = gap_get_outgoing_connection();
2659                         }
2660 
2661                         // remove entry
2662                         if (conn){
2663                             // outgoing le connection establishment is done
2664                             if (hci_is_le_connection(conn)){
2665                                 hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2666                                 hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2667                             }
2668                             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2669                             btstack_memory_hci_connection_free( conn );
2670                         }
2671                         break;
2672                     }
2673 #endif
2674 
2675                     // on success, both hosts receive connection complete event
2676                     if (packet[6] == HCI_ROLE_MASTER){
2677 #ifdef ENABLE_LE_CENTRAL
2678                         // if we're master on an le connection, it was an outgoing connection and we're done with it
2679                         if (hci_is_le_connection(conn)){
2680                             hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2681                             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2682                         }
2683 #endif
2684                     } else {
2685 #ifdef ENABLE_LE_PERIPHERAL
2686                         // if we're slave, it was an incoming connection, advertisements have stopped
2687                         hci_stack->le_advertisements_active = 0;
2688 #endif
2689                     }
2690                     // LE connections are auto-accepted, so just create a connection if there isn't one already
2691                     if (!conn){
2692                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2693                     }
2694                     // no memory, sorry.
2695                     if (!conn){
2696                         break;
2697                     }
2698 
2699                     conn->state = OPEN;
2700                     conn->role  = packet[6];
2701                     conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2702                     conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2703 
2704 #ifdef ENABLE_LE_PERIPHERAL
2705                     if (packet[6] == HCI_ROLE_SLAVE){
2706                         hci_update_advertisements_enabled_for_current_roles();
2707                     }
2708 #endif
2709 
2710                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2711 
2712                     // restart timer
2713                     // btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2714                     // btstack_run_loop_add_timer(&conn->timeout);
2715 
2716                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2717 
2718                     hci_emit_nr_connections_changed();
2719                     break;
2720 
2721                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
2722                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
2723                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
2724                     conn = hci_connection_for_handle(handle);
2725                     if (!conn) break;
2726                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
2727                     break;
2728 
2729                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
2730                     // connection
2731                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
2732                     conn = hci_connection_for_handle(handle);
2733                     if (conn) {
2734                         // read arguments
2735                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
2736                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
2737                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
2738                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
2739 
2740                         // validate against current connection parameter range
2741                         le_connection_parameter_range_t existing_range;
2742                         gap_get_connection_parameter_range(&existing_range);
2743                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
2744                         if (update_parameter){
2745                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
2746                             conn->le_conn_interval_min = le_conn_interval_min;
2747                             conn->le_conn_interval_max = le_conn_interval_max;
2748                             conn->le_conn_latency = le_conn_latency;
2749                             conn->le_supervision_timeout = le_supervision_timeout;
2750                         } else {
2751                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY;
2752                         }
2753                     }
2754                     break;
2755 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
2756                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
2757                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
2758                     conn = hci_connection_for_handle(handle);
2759                     if (conn) {
2760                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
2761                     }
2762                     break;
2763 #endif
2764                 default:
2765                     break;
2766             }
2767             break;
2768 #endif
2769         case HCI_EVENT_VENDOR_SPECIFIC:
2770             // Vendor specific commands often create vendor specific event instead of num completed packets
2771             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
2772             switch (hci_stack->manufacturer){
2773                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
2774                     hci_stack->num_cmd_packets = 1;
2775                     break;
2776                 default:
2777                     break;
2778             }
2779             break;
2780         default:
2781             break;
2782     }
2783 
2784     handle_event_for_current_stack_state(packet, size);
2785 
2786     // notify upper stack
2787 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
2788 
2789     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
2790     if (hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE){
2791         if (!packet[2]){
2792             handle = little_endian_read_16(packet, 3);
2793             hci_connection_t * aConn = hci_connection_for_handle(handle);
2794             if (aConn) {
2795                 // discard connection if app did not trigger a reconnect in the event handler
2796                 if (aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
2797                     hci_shutdown_connection(aConn);
2798                 }
2799             }
2800         }
2801     }
2802 
2803 	// execute main loop
2804 	hci_run();
2805 }
2806 
2807 #ifdef ENABLE_CLASSIC
2808 
2809 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
2810 static void sco_schedule_tx(hci_connection_t * conn);
2811 
2812 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
2813     log_debug("SCO TX Timeout");
2814     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
2815     hci_connection_t * conn = hci_connection_for_handle(con_handle);
2816     if (!conn) return;
2817 
2818     // trigger send
2819     conn->sco_tx_ready = 1;
2820     // extra packet if CVSD but SCO buffer is too short
2821     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
2822         conn->sco_tx_ready++;
2823     }
2824     hci_notify_if_sco_can_send_now();
2825 }
2826 
2827 
2828 #define SCO_TX_AFTER_RX_MS (6)
2829 
2830 static void sco_schedule_tx(hci_connection_t * conn){
2831 
2832     uint32_t now = btstack_run_loop_get_time_ms();
2833     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
2834     int time_delta_ms = sco_tx_ms - now;
2835 
2836     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
2837 
2838     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
2839     btstack_run_loop_set_timer(timer, time_delta_ms);
2840     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
2841     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
2842     btstack_run_loop_add_timer(timer);
2843 }
2844 
2845 static void sco_handler(uint8_t * packet, uint16_t size){
2846     // lookup connection struct
2847     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
2848     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
2849     if (!conn) return;
2850 
2851     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
2852     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
2853         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
2854             packet[2] = 0x3c;
2855             memmove(&packet[3], &packet[23], 63);
2856             size = 63;
2857         }
2858     }
2859 
2860     if (hci_have_usb_transport()){
2861         // Nothing to do
2862     } else {
2863         // 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);
2864         if (hci_stack->synchronous_flow_control_enabled == 0){
2865             uint32_t now = btstack_run_loop_get_time_ms();
2866 
2867             if (!conn->sco_rx_valid){
2868                 // ignore first 10 packets
2869                 conn->sco_rx_count++;
2870                 // log_debug("sco rx count %u", conn->sco_rx_count);
2871                 if (conn->sco_rx_count == 10) {
2872                     // use first timestamp as is and pretent it just started
2873                     conn->sco_rx_ms = now;
2874                     conn->sco_rx_valid = 1;
2875                     conn->sco_rx_count = 0;
2876                     sco_schedule_tx(conn);
2877                 }
2878             } else {
2879                 // track expected arrival timme
2880                 conn->sco_rx_count++;
2881                 conn->sco_rx_ms += 7;
2882                 int delta = (int32_t) (now - conn->sco_rx_ms);
2883                 if (delta > 0){
2884                     conn->sco_rx_ms++;
2885                 }
2886                 // log_debug("sco rx %u", conn->sco_rx_ms);
2887                 sco_schedule_tx(conn);
2888             }
2889         }
2890     }
2891     // deliver to app
2892     if (hci_stack->sco_packet_handler) {
2893         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
2894     }
2895 
2896 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
2897     conn->num_packets_completed++;
2898     hci_stack->host_completed_packets = 1;
2899     hci_run();
2900 #endif
2901 }
2902 #endif
2903 
2904 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
2905     hci_dump_packet(packet_type, 1, packet, size);
2906     switch (packet_type) {
2907         case HCI_EVENT_PACKET:
2908             event_handler(packet, size);
2909             break;
2910         case HCI_ACL_DATA_PACKET:
2911             acl_handler(packet, size);
2912             break;
2913 #ifdef ENABLE_CLASSIC
2914         case HCI_SCO_DATA_PACKET:
2915             sco_handler(packet, size);
2916             break;
2917 #endif
2918         default:
2919             break;
2920     }
2921 }
2922 
2923 /**
2924  * @brief Add event packet handler.
2925  */
2926 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
2927     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
2928 }
2929 
2930 
2931 /** Register HCI packet handlers */
2932 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
2933     hci_stack->acl_packet_handler = handler;
2934 }
2935 
2936 #ifdef ENABLE_CLASSIC
2937 /**
2938  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
2939  */
2940 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
2941     hci_stack->sco_packet_handler = handler;
2942 }
2943 #endif
2944 
2945 static void hci_state_reset(void){
2946     // no connections yet
2947     hci_stack->connections = NULL;
2948 
2949     // keep discoverable/connectable as this has been requested by the client(s)
2950     // hci_stack->discoverable = 0;
2951     // hci_stack->connectable = 0;
2952     // hci_stack->bondable = 1;
2953     // hci_stack->own_addr_type = 0;
2954 
2955     // buffer is free
2956     hci_stack->hci_packet_buffer_reserved = 0;
2957 
2958     // no pending cmds
2959     hci_stack->decline_reason = 0;
2960     hci_stack->new_scan_enable_value = 0xff;
2961 
2962     // LE
2963 #ifdef ENABLE_BLE
2964     memset(hci_stack->le_random_address, 0, 6);
2965     hci_stack->le_random_address_set = 0;
2966 #endif
2967 #ifdef ENABLE_LE_CENTRAL
2968     hci_stack->le_scanning_active  = 0;
2969     hci_stack->le_scan_type = 0xff;
2970     hci_stack->le_scan_filter_policy = 0;
2971     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2972     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2973     hci_stack->le_whitelist = 0;
2974     hci_stack->le_whitelist_capacity = 0;
2975 #endif
2976 }
2977 
2978 #ifdef ENABLE_CLASSIC
2979 /**
2980  * @brief Configure Bluetooth hardware control. Has to be called before power on.
2981  */
2982 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
2983     // store and open remote device db
2984     hci_stack->link_key_db = link_key_db;
2985     if (hci_stack->link_key_db) {
2986         hci_stack->link_key_db->open();
2987     }
2988 }
2989 #endif
2990 
2991 void hci_init(const hci_transport_t *transport, const void *config){
2992 
2993 #ifdef HAVE_MALLOC
2994     if (!hci_stack) {
2995         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
2996     }
2997 #else
2998     hci_stack = &hci_stack_static;
2999 #endif
3000     memset(hci_stack, 0, sizeof(hci_stack_t));
3001 
3002     // reference to use transport layer implementation
3003     hci_stack->hci_transport = transport;
3004 
3005     // reference to used config
3006     hci_stack->config = config;
3007 
3008     // setup pointer for outgoing packet buffer
3009     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3010 
3011     // max acl payload size defined in config.h
3012     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3013 
3014     // register packet handlers with transport
3015     transport->register_packet_handler(&packet_handler);
3016 
3017     hci_stack->state = HCI_STATE_OFF;
3018 
3019     // class of device
3020     hci_stack->class_of_device = 0x007a020c; // Smartphone
3021 
3022     // bondable by default
3023     hci_stack->bondable = 1;
3024 
3025 #ifdef ENABLE_CLASSIC
3026     // classic name
3027     hci_stack->local_name = default_classic_name;
3028 
3029     // Master slave policy
3030     hci_stack->master_slave_policy = 1;
3031 
3032     // Allow Role Switch
3033     hci_stack->allow_role_switch = 1;
3034 
3035     // Default / minimum security level = 2
3036     hci_stack->gap_security_level = LEVEL_2;
3037 
3038     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3039     hci_stack->gap_required_encyrption_key_size = 7;
3040 #endif
3041 
3042     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3043     hci_stack->ssp_enable = 1;
3044     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3045     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3046     hci_stack->ssp_auto_accept = 1;
3047 
3048     // Secure Connections: enable (requires support from Controller)
3049     hci_stack->secure_connections_enable = true;
3050 
3051     // voice setting - signed 16 bit pcm data with CVSD over the air
3052     hci_stack->sco_voice_setting = 0x60;
3053 
3054 #ifdef ENABLE_LE_CENTRAL
3055     // connection parameter to use for outgoing connections
3056     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3057     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3058     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3059     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3060     hci_stack->le_connection_latency      = 4;         // 4
3061     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3062     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3063     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3064 
3065     // default LE Scanning
3066     hci_stack->le_scan_interval = 0x1e0;
3067     hci_stack->le_scan_window   =  0x30;
3068 #endif
3069 
3070 #ifdef ENABLE_LE_PERIPHERAL
3071     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3072 #endif
3073 
3074     // connection parameter range used to answer connection parameter update requests in l2cap
3075     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3076     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3077     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3078     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3079     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3080     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3081 
3082     hci_state_reset();
3083 }
3084 
3085 /**
3086  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3087  */
3088 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3089     hci_stack->chipset = chipset_driver;
3090 
3091     // reset chipset driver - init is also called on power_up
3092     if (hci_stack->chipset && hci_stack->chipset->init){
3093         hci_stack->chipset->init(hci_stack->config);
3094     }
3095 }
3096 
3097 /**
3098  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3099  */
3100 void hci_set_control(const btstack_control_t *hardware_control){
3101     // references to used control implementation
3102     hci_stack->control = hardware_control;
3103     // init with transport config
3104     hardware_control->init(hci_stack->config);
3105 }
3106 
3107 void hci_close(void){
3108     // close remote device db
3109     if (hci_stack->link_key_db) {
3110         hci_stack->link_key_db->close();
3111     }
3112 
3113     btstack_linked_list_iterator_t lit;
3114     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3115     while (btstack_linked_list_iterator_has_next(&lit)){
3116         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3117         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3118         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3119         hci_shutdown_connection(connection);
3120     }
3121 
3122     hci_power_control(HCI_POWER_OFF);
3123 
3124 #ifdef HAVE_MALLOC
3125     free(hci_stack);
3126 #endif
3127     hci_stack = NULL;
3128 }
3129 
3130 #ifdef ENABLE_CLASSIC
3131 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3132     // validate ranage and set
3133     if (encryption_key_size < 7)  return;
3134     if (encryption_key_size > 16) return;
3135     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3136 }
3137 
3138 void gap_set_security_level(gap_security_level_t security_level){
3139     hci_stack->gap_security_level = security_level;
3140 }
3141 
3142 gap_security_level_t gap_get_security_level(void){
3143     return hci_stack->gap_security_level;
3144 }
3145 #endif
3146 
3147 #ifdef ENABLE_CLASSIC
3148 void gap_set_class_of_device(uint32_t class_of_device){
3149     hci_stack->class_of_device = class_of_device;
3150 }
3151 
3152 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3153     hci_stack->default_link_policy_settings = default_link_policy_settings;
3154 }
3155 
3156 void gap_set_allow_role_switch(bool allow_role_switch){
3157     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3158 }
3159 
3160 uint8_t hci_get_allow_role_switch(void){
3161     return  hci_stack->allow_role_switch;
3162 }
3163 
3164 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3165     hci_stack->link_supervision_timeout = link_supervision_timeout;
3166 }
3167 
3168 void hci_disable_l2cap_timeout_check(void){
3169     disable_l2cap_timeouts = 1;
3170 }
3171 #endif
3172 
3173 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
3174 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3175 void hci_set_bd_addr(bd_addr_t addr){
3176     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3177     hci_stack->custom_bd_addr_set = 1;
3178 }
3179 #endif
3180 
3181 // State-Module-Driver overview
3182 // state                    module  low-level
3183 // HCI_STATE_OFF             off      close
3184 // HCI_STATE_INITIALIZING,   on       open
3185 // HCI_STATE_WORKING,        on       open
3186 // HCI_STATE_HALTING,        on       open
3187 // HCI_STATE_SLEEPING,    off/sleep   close
3188 // HCI_STATE_FALLING_ASLEEP  on       open
3189 
3190 static int hci_power_control_on(void){
3191 
3192     // power on
3193     int err = 0;
3194     if (hci_stack->control && hci_stack->control->on){
3195         err = (*hci_stack->control->on)();
3196     }
3197     if (err){
3198         log_error( "POWER_ON failed");
3199         hci_emit_hci_open_failed();
3200         return err;
3201     }
3202 
3203     // int chipset driver
3204     if (hci_stack->chipset && hci_stack->chipset->init){
3205         hci_stack->chipset->init(hci_stack->config);
3206     }
3207 
3208     // init transport
3209     if (hci_stack->hci_transport->init){
3210         hci_stack->hci_transport->init(hci_stack->config);
3211     }
3212 
3213     // open transport
3214     err = hci_stack->hci_transport->open();
3215     if (err){
3216         log_error( "HCI_INIT failed, turning Bluetooth off again");
3217         if (hci_stack->control && hci_stack->control->off){
3218             (*hci_stack->control->off)();
3219         }
3220         hci_emit_hci_open_failed();
3221         return err;
3222     }
3223     return 0;
3224 }
3225 
3226 static void hci_power_control_off(void){
3227 
3228     log_info("hci_power_control_off");
3229 
3230     // close low-level device
3231     hci_stack->hci_transport->close();
3232 
3233     log_info("hci_power_control_off - hci_transport closed");
3234 
3235     // power off
3236     if (hci_stack->control && hci_stack->control->off){
3237         (*hci_stack->control->off)();
3238     }
3239 
3240     log_info("hci_power_control_off - control closed");
3241 
3242     hci_stack->state = HCI_STATE_OFF;
3243 }
3244 
3245 static void hci_power_control_sleep(void){
3246 
3247     log_info("hci_power_control_sleep");
3248 
3249 #if 0
3250     // don't close serial port during sleep
3251 
3252     // close low-level device
3253     hci_stack->hci_transport->close(hci_stack->config);
3254 #endif
3255 
3256     // sleep mode
3257     if (hci_stack->control && hci_stack->control->sleep){
3258         (*hci_stack->control->sleep)();
3259     }
3260 
3261     hci_stack->state = HCI_STATE_SLEEPING;
3262 }
3263 
3264 static int hci_power_control_wake(void){
3265 
3266     log_info("hci_power_control_wake");
3267 
3268     // wake on
3269     if (hci_stack->control && hci_stack->control->wake){
3270         (*hci_stack->control->wake)();
3271     }
3272 
3273 #if 0
3274     // open low-level device
3275     int err = hci_stack->hci_transport->open(hci_stack->config);
3276     if (err){
3277         log_error( "HCI_INIT failed, turning Bluetooth off again");
3278         if (hci_stack->control && hci_stack->control->off){
3279             (*hci_stack->control->off)();
3280         }
3281         hci_emit_hci_open_failed();
3282         return err;
3283     }
3284 #endif
3285 
3286     return 0;
3287 }
3288 
3289 static void hci_power_transition_to_initializing(void){
3290     // set up state machine
3291     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3292     hci_stack->hci_packet_buffer_reserved = 0;
3293     hci_stack->state = HCI_STATE_INITIALIZING;
3294     hci_stack->substate = HCI_INIT_SEND_RESET;
3295 }
3296 
3297 int hci_power_control(HCI_POWER_MODE power_mode){
3298 
3299     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
3300 
3301     int err = 0;
3302     switch (hci_stack->state){
3303 
3304         case HCI_STATE_OFF:
3305             switch (power_mode){
3306                 case HCI_POWER_ON:
3307                     err = hci_power_control_on();
3308                     if (err) {
3309                         log_error("hci_power_control_on() error %d", err);
3310                         return err;
3311                     }
3312                     hci_power_transition_to_initializing();
3313                     break;
3314                 case HCI_POWER_OFF:
3315                     // do nothing
3316                     break;
3317                 case HCI_POWER_SLEEP:
3318                     // do nothing (with SLEEP == OFF)
3319                     break;
3320             }
3321             break;
3322 
3323         case HCI_STATE_INITIALIZING:
3324             switch (power_mode){
3325                 case HCI_POWER_ON:
3326                     // do nothing
3327                     break;
3328                 case HCI_POWER_OFF:
3329                     // no connections yet, just turn it off
3330                     hci_power_control_off();
3331                     break;
3332                 case HCI_POWER_SLEEP:
3333                     // no connections yet, just turn it off
3334                     hci_power_control_sleep();
3335                     break;
3336             }
3337             break;
3338 
3339         case HCI_STATE_WORKING:
3340             switch (power_mode){
3341                 case HCI_POWER_ON:
3342                     // do nothing
3343                     break;
3344                 case HCI_POWER_OFF:
3345                     // see hci_run
3346                     hci_stack->state = HCI_STATE_HALTING;
3347                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3348                     break;
3349                 case HCI_POWER_SLEEP:
3350                     // see hci_run
3351                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3352                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3353                     break;
3354             }
3355             break;
3356 
3357         case HCI_STATE_HALTING:
3358             switch (power_mode){
3359                 case HCI_POWER_ON:
3360                     hci_power_transition_to_initializing();
3361                     break;
3362                 case HCI_POWER_OFF:
3363                     // do nothing
3364                     break;
3365                 case HCI_POWER_SLEEP:
3366                     // see hci_run
3367                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3368                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3369                     break;
3370             }
3371             break;
3372 
3373         case HCI_STATE_FALLING_ASLEEP:
3374             switch (power_mode){
3375                 case HCI_POWER_ON:
3376 
3377 #ifdef HAVE_PLATFORM_IPHONE_OS
3378                     // nothing to do, if H4 supports power management
3379                     if (btstack_control_iphone_power_management_enabled()){
3380                         hci_stack->state = HCI_STATE_INITIALIZING;
3381                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
3382                         break;
3383                     }
3384 #endif
3385                     hci_power_transition_to_initializing();
3386                     break;
3387                 case HCI_POWER_OFF:
3388                     // see hci_run
3389                     hci_stack->state = HCI_STATE_HALTING;
3390                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3391                     break;
3392                 case HCI_POWER_SLEEP:
3393                     // do nothing
3394                     break;
3395             }
3396             break;
3397 
3398         case HCI_STATE_SLEEPING:
3399             switch (power_mode){
3400                 case HCI_POWER_ON:
3401 
3402 #ifdef HAVE_PLATFORM_IPHONE_OS
3403                     // nothing to do, if H4 supports power management
3404                     if (btstack_control_iphone_power_management_enabled()){
3405                         hci_stack->state = HCI_STATE_INITIALIZING;
3406                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
3407                         hci_update_scan_enable();
3408                         break;
3409                     }
3410 #endif
3411                     err = hci_power_control_wake();
3412                     if (err) return err;
3413                     hci_power_transition_to_initializing();
3414                     break;
3415                 case HCI_POWER_OFF:
3416                     hci_stack->state = HCI_STATE_HALTING;
3417                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3418                     break;
3419                 case HCI_POWER_SLEEP:
3420                     // do nothing
3421                     break;
3422             }
3423             break;
3424     }
3425 
3426     // create internal event
3427 	hci_emit_state();
3428 
3429 	// trigger next/first action
3430 	hci_run();
3431 
3432     return 0;
3433 }
3434 
3435 
3436 #ifdef ENABLE_CLASSIC
3437 
3438 static void hci_update_scan_enable(void){
3439     // 2 = page scan, 1 = inq scan
3440     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
3441     hci_run();
3442 }
3443 
3444 void gap_discoverable_control(uint8_t enable){
3445     if (enable) enable = 1; // normalize argument
3446 
3447     if (hci_stack->discoverable == enable){
3448         hci_emit_discoverable_enabled(hci_stack->discoverable);
3449         return;
3450     }
3451 
3452     hci_stack->discoverable = enable;
3453     hci_update_scan_enable();
3454 }
3455 
3456 void gap_connectable_control(uint8_t enable){
3457     if (enable) enable = 1; // normalize argument
3458 
3459     // don't emit event
3460     if (hci_stack->connectable == enable) return;
3461 
3462     hci_stack->connectable = enable;
3463     hci_update_scan_enable();
3464 }
3465 #endif
3466 
3467 void gap_local_bd_addr(bd_addr_t address_buffer){
3468     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
3469 }
3470 
3471 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3472 static void hci_host_num_completed_packets(void){
3473 
3474     // create packet manually as arrays are not supported and num_commands should not get reduced
3475     hci_reserve_packet_buffer();
3476     uint8_t * packet = hci_get_outgoing_packet_buffer();
3477 
3478     uint16_t size = 0;
3479     uint16_t num_handles = 0;
3480     packet[size++] = 0x35;
3481     packet[size++] = 0x0c;
3482     size++;  // skip param len
3483     size++;  // skip num handles
3484 
3485     // add { handle, packets } entries
3486     btstack_linked_item_t * it;
3487     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3488         hci_connection_t * connection = (hci_connection_t *) it;
3489         if (connection->num_packets_completed){
3490             little_endian_store_16(packet, size, connection->con_handle);
3491             size += 2;
3492             little_endian_store_16(packet, size, connection->num_packets_completed);
3493             size += 2;
3494             //
3495             num_handles++;
3496             connection->num_packets_completed = 0;
3497         }
3498     }
3499 
3500     packet[2] = size - 3;
3501     packet[3] = num_handles;
3502 
3503     hci_stack->host_completed_packets = 0;
3504 
3505     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
3506     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
3507 
3508     // release packet buffer for synchronous transport implementations
3509     if (hci_transport_synchronous()){
3510         hci_release_packet_buffer();
3511         hci_emit_transport_packet_sent();
3512     }
3513 }
3514 #endif
3515 
3516 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
3517     UNUSED(ds);
3518     hci_stack->substate = HCI_HALTING_CLOSE;
3519     // allow packet handlers to defer final shutdown
3520     hci_emit_state();
3521     hci_run();
3522 }
3523 
3524 static bool hci_run_acl_fragments(void){
3525     if (hci_stack->acl_fragmentation_total_size > 0u) {
3526         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
3527         hci_connection_t *connection = hci_connection_for_handle(con_handle);
3528         if (connection) {
3529             if (hci_can_send_prepared_acl_packet_now(con_handle)){
3530                 hci_send_acl_packet_fragments(connection);
3531                 return true;
3532             }
3533         } else {
3534             // connection gone -> discard further fragments
3535             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
3536             hci_stack->acl_fragmentation_total_size = 0;
3537             hci_stack->acl_fragmentation_pos = 0;
3538         }
3539     }
3540     return false;
3541 }
3542 
3543 #ifdef ENABLE_CLASSIC
3544 static bool hci_run_general_gap_classic(void){
3545 
3546     // decline incoming connections
3547     if (hci_stack->decline_reason){
3548         uint8_t reason = hci_stack->decline_reason;
3549         hci_stack->decline_reason = 0;
3550         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
3551         return true;
3552     }
3553     // send scan enable
3554     if ((hci_stack->state == HCI_STATE_WORKING) && (hci_stack->new_scan_enable_value != 0xff) && hci_classic_supported()){
3555         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
3556         hci_stack->new_scan_enable_value = 0xff;
3557         return true;
3558     }
3559     // start/stop inquiry
3560     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
3561         uint8_t duration = hci_stack->inquiry_state;
3562         hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
3563         hci_send_cmd(&hci_inquiry, GAP_IAC_GENERAL_INQUIRY, duration, 0);
3564         return true;
3565     }
3566     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
3567         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
3568         hci_send_cmd(&hci_inquiry_cancel);
3569         return true;
3570     }
3571     // remote name request
3572     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
3573         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
3574         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
3575                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
3576         return true;
3577     }
3578     // pairing
3579     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
3580         uint8_t state = hci_stack->gap_pairing_state;
3581         hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
3582         switch (state){
3583             case GAP_PAIRING_STATE_SEND_PIN:
3584                 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);
3585                 break;
3586             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
3587                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
3588                 break;
3589             case GAP_PAIRING_STATE_SEND_PASSKEY:
3590                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
3591                 break;
3592             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
3593                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
3594                 break;
3595             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
3596                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
3597                 break;
3598             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
3599                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
3600                 break;
3601             default:
3602                 break;
3603         }
3604         return true;
3605     }
3606     return false;
3607 }
3608 #endif
3609 
3610 #ifdef ENABLE_BLE
3611 static bool hci_run_general_gap_le(void){
3612 
3613     // advertisements, active scanning, and creating connections requires random address to be set if using private address
3614 
3615     if (hci_stack->state != HCI_STATE_WORKING) return false;
3616     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
3617 
3618     // check if whitelist needs modification
3619     bool whitelist_modification_pending = false;
3620     btstack_linked_list_iterator_t lit;
3621     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3622     while (btstack_linked_list_iterator_has_next(&lit)){
3623         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3624         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
3625             whitelist_modification_pending = true;
3626             break;
3627         }
3628     }
3629 
3630 #ifdef ENABLE_LE_CENTRAL
3631     // scanning control
3632     bool scanning_stop = false;
3633     if (hci_stack->le_scanning_active) {
3634         // stop if:
3635         // - parameter change required
3636         // - it's disabled
3637         // - whitelist change required but used for scanning
3638         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
3639         if ((hci_stack->le_scan_type != 0xffu) || !hci_stack->le_scanning_enabled || scanning_uses_whitelist){
3640             scanning_stop = false;
3641         }
3642     }
3643 
3644     if (scanning_stop){
3645         hci_stack->le_scanning_active = 0;
3646         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
3647         return true;
3648     }
3649 
3650     if (hci_stack->le_scan_type != 0xffu){
3651         int scan_type = (int) hci_stack->le_scan_type;
3652         hci_stack->le_scan_type = 0xff;
3653         hci_send_cmd(&hci_le_set_scan_parameters, scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
3654                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
3655         return true;
3656     }
3657 #endif
3658 
3659 #ifdef ENABLE_LE_CENTRAL
3660     // connecting control
3661     bool connecting_stop = false;
3662     if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
3663         // stop connecting if:
3664         // - connecting uses white and whitelist modification pending
3665         // - if it got disabled
3666         bool connecting_uses_whitelist = hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST;
3667         if ((connecting_uses_whitelist && whitelist_modification_pending) || (hci_stack->le_connecting_request == LE_CONNECTING_IDLE)) {
3668             connecting_stop = true;
3669         }
3670     }
3671 
3672     if (connecting_stop){
3673         hci_send_cmd(&hci_le_create_connection_cancel);
3674         return true;
3675     }
3676 #endif
3677 
3678 #ifdef ENABLE_LE_PERIPHERAL
3679     // le advertisement control
3680     bool advertising_stop = false;
3681     if (hci_stack->le_advertisements_active){
3682         // stop if:
3683         // - parameter change required
3684         // - it's disabled
3685         // - whitelist change required but used for scanning
3686         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy > 0;
3687         if ((hci_stack->le_advertisements_todo != 0) || !hci_stack->le_advertisements_enabled_for_current_roles || advertising_uses_whitelist) {
3688             advertising_stop = true;
3689         }
3690     }
3691 
3692     if (advertising_stop){
3693         hci_stack->le_advertisements_active = 0;
3694         hci_send_cmd(&hci_le_set_advertise_enable, 0);
3695         return true;
3696     }
3697 
3698     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
3699         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3700         hci_send_cmd(&hci_le_set_advertising_parameters,
3701                      hci_stack->le_advertisements_interval_min,
3702                      hci_stack->le_advertisements_interval_max,
3703                      hci_stack->le_advertisements_type,
3704                      hci_stack->le_own_addr_type,
3705                      hci_stack->le_advertisements_direct_address_type,
3706                      hci_stack->le_advertisements_direct_address,
3707                      hci_stack->le_advertisements_channel_map,
3708                      hci_stack->le_advertisements_filter_policy);
3709         return true;
3710     }
3711     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
3712         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3713         uint8_t adv_data_clean[31];
3714         memset(adv_data_clean, 0, sizeof(adv_data_clean));
3715         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
3716                      hci_stack->le_advertisements_data_len);
3717         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
3718         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
3719         return true;
3720     }
3721     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
3722         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
3723         uint8_t scan_data_clean[31];
3724         memset(scan_data_clean, 0, sizeof(scan_data_clean));
3725         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
3726                      hci_stack->le_scan_response_data_len);
3727         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
3728         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
3729         return true;
3730     }
3731 #endif
3732 
3733     //
3734     // LE Whitelist Management
3735     //
3736 
3737     if (whitelist_modification_pending){
3738 
3739         // add/remove entries
3740         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3741         while (btstack_linked_list_iterator_has_next(&lit)){
3742             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3743             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
3744                 entry->state = LE_WHITELIST_ON_CONTROLLER;
3745                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
3746                 return true;
3747             }
3748             if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
3749                 bd_addr_t address;
3750                 bd_addr_type_t address_type = entry->address_type;
3751                 (void)memcpy(address, entry->address, 6);
3752                 btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
3753                 btstack_memory_whitelist_entry_free(entry);
3754                 hci_send_cmd(&hci_le_remove_device_from_white_list, address_type, address);
3755                 return true;
3756             }
3757         }
3758     }
3759 
3760 #ifdef ENABLE_LE_PERIPHERAL
3761     // re-start advertising
3762     if (hci_stack->le_advertisements_enabled_for_current_roles && (hci_stack->le_advertisements_active == 0)){
3763         // check if advertisements should be enabled given
3764         hci_stack->le_advertisements_active = 1;
3765         hci_send_cmd(&hci_le_set_advertise_enable, 1);
3766         return true;
3767     }
3768 #endif
3769 
3770 #ifdef ENABLE_LE_CENTRAL
3771     // re-start scanning
3772     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
3773         hci_stack->le_scanning_active = true;
3774         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
3775         return true;
3776     }
3777 #endif
3778 
3779 #ifdef ENABLE_LE_CENTRAL
3780     // re-start connecting
3781     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
3782         bd_addr_t null_addr;
3783         memset(null_addr, 0, 6);
3784         hci_send_cmd(&hci_le_create_connection,
3785                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
3786                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
3787                      1,         // use whitelist
3788                      0,         // peer address type
3789                      null_addr, // peer bd addr
3790                      hci_stack->le_own_addr_type, // our addr type:
3791                      hci_stack->le_connection_interval_min,    // conn interval min
3792                      hci_stack->le_connection_interval_max,    // conn interval max
3793                      hci_stack->le_connection_latency,         // conn latency
3794                      hci_stack->le_supervision_timeout,        // conn latency
3795                      hci_stack->le_minimum_ce_length,          // min ce length
3796                      hci_stack->le_maximum_ce_length           // max ce length
3797         );
3798         return true;
3799     }
3800 #endif
3801     return false;
3802 }
3803 #endif
3804 
3805 static bool hci_run_general_pending_commands(void){
3806     btstack_linked_item_t * it;
3807     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
3808         hci_connection_t * connection = (hci_connection_t *) it;
3809 
3810         switch(connection->state){
3811             case SEND_CREATE_CONNECTION:
3812                 switch(connection->address_type){
3813 #ifdef ENABLE_CLASSIC
3814                     case BD_ADDR_TYPE_ACL:
3815                         log_info("sending hci_create_connection");
3816                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
3817                         break;
3818 #endif
3819                     default:
3820 #ifdef ENABLE_BLE
3821 #ifdef ENABLE_LE_CENTRAL
3822                         // track outgoing connection
3823                         hci_stack->outgoing_addr_type = connection->address_type;
3824                         (void)memcpy(hci_stack->outgoing_addr,
3825                                      connection->address, 6);
3826                         log_info("sending hci_le_create_connection");
3827                         hci_send_cmd(&hci_le_create_connection,
3828                                      hci_stack->le_connection_scan_interval,    // conn scan interval
3829                                      hci_stack->le_connection_scan_window,      // conn scan windows
3830                                      0,         // don't use whitelist
3831                                      connection->address_type, // peer address type
3832                                      connection->address,      // peer bd addr
3833                                      hci_stack->le_own_addr_type, // our addr type:
3834                                      hci_stack->le_connection_interval_min,    // conn interval min
3835                                      hci_stack->le_connection_interval_max,    // conn interval max
3836                                      hci_stack->le_connection_latency,         // conn latency
3837                                      hci_stack->le_supervision_timeout,        // conn latency
3838                                      hci_stack->le_minimum_ce_length,          // min ce length
3839                                      hci_stack->le_maximum_ce_length          // max ce length
3840                         );
3841                         connection->state = SENT_CREATE_CONNECTION;
3842 #endif
3843 #endif
3844                         break;
3845                 }
3846                 return true;
3847 
3848 #ifdef ENABLE_CLASSIC
3849             case RECEIVED_CONNECTION_REQUEST:
3850                 connection->role  = HCI_ROLE_SLAVE;
3851                 if (connection->address_type == BD_ADDR_TYPE_ACL){
3852                     log_info("sending hci_accept_connection_request");
3853                     connection->state = ACCEPTED_CONNECTION_REQUEST;
3854                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
3855                 }
3856                 return true;
3857 #endif
3858 
3859 #ifdef ENABLE_BLE
3860 #ifdef ENABLE_LE_CENTRAL
3861             case SEND_CANCEL_CONNECTION:
3862                 connection->state = SENT_CANCEL_CONNECTION;
3863                 hci_send_cmd(&hci_le_create_connection_cancel);
3864                 return true;
3865 #endif
3866 #endif
3867             case SEND_DISCONNECT:
3868                 connection->state = SENT_DISCONNECT;
3869                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3870                 return true;
3871 
3872             default:
3873                 break;
3874         }
3875 
3876         // no further commands if connection is about to get shut down
3877         if (connection->state == SENT_DISCONNECT) continue;
3878 
3879         if (connection->authentication_flags & READ_RSSI){
3880             connectionClearAuthenticationFlags(connection, READ_RSSI);
3881             hci_send_cmd(&hci_read_rssi, connection->con_handle);
3882             return true;
3883         }
3884 
3885 #ifdef ENABLE_CLASSIC
3886 
3887         if (connection->authentication_flags & WRITE_SUPERVISION_TIMEOUT){
3888             connectionClearAuthenticationFlags(connection, WRITE_SUPERVISION_TIMEOUT);
3889             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
3890             return true;
3891         }
3892 
3893         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
3894             log_info("responding to link key request");
3895             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
3896 
3897             link_key_t link_key;
3898             link_key_type_t link_key_type;
3899             bool have_link_key = hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type);
3900 
3901             const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
3902             bool sc_enabled_remote = (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
3903             bool sc_downgrade = have_link_key && (gap_secure_connection_for_link_key_type(link_key_type) == 1) && !sc_enabled_remote;
3904             if (sc_downgrade){
3905                 log_info("Link key based on SC, but remote does not support SC -> disconnect");
3906                 connection->state = SENT_DISCONNECT;
3907                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
3908                 return true;
3909             }
3910 
3911             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level);
3912             if (have_link_key && security_level_sufficient){
3913                 connection->link_key_type = link_key_type;
3914                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
3915             } else {
3916                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
3917             }
3918             return true;
3919         }
3920 
3921         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
3922             log_info("denying to pin request");
3923             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
3924             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
3925             return true;
3926         }
3927 
3928         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
3929             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
3930             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
3931             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
3932                 // tweak authentication requirements
3933                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
3934                 if (connection->bonding_flags & BONDING_DEDICATED){
3935                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
3936                 }
3937                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
3938                     authreq |= 1;
3939                 }
3940                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
3941             } else {
3942                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
3943             }
3944             return true;
3945         }
3946 
3947         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
3948             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
3949             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
3950             return true;
3951         }
3952 
3953         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
3954             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
3955             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
3956             return true;
3957         }
3958 
3959         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
3960             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
3961             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
3962             return true;
3963         }
3964 
3965         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
3966             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
3967             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
3968             return true;
3969         }
3970 
3971         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
3972             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
3973             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
3974             return true;
3975         }
3976 
3977         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
3978             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
3979             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
3980             connection->state = SENT_DISCONNECT;
3981             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3982             return true;
3983         }
3984 
3985         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
3986             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
3987             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
3988             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
3989             return true;
3990         }
3991 
3992         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
3993             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
3994             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
3995             return true;
3996         }
3997         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
3998             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3999             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
4000             return true;
4001         }
4002 #endif
4003 
4004         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
4005             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
4006             if (connection->state != SENT_DISCONNECT){
4007                 connection->state = SENT_DISCONNECT;
4008                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4009                 return true;
4010             }
4011         }
4012 
4013 #ifdef ENABLE_CLASSIC
4014         uint16_t sniff_min_interval;
4015         switch (connection->sniff_min_interval){
4016             case 0:
4017                 break;
4018             case 0xffff:
4019                 connection->sniff_min_interval = 0;
4020                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
4021                 return true;
4022             default:
4023                 sniff_min_interval = connection->sniff_min_interval;
4024                 connection->sniff_min_interval = 0;
4025                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
4026                 return true;
4027         }
4028 
4029         if (connection->request_role != HCI_ROLE_INVALID){
4030             hci_role_t  role = connection->request_role;
4031             connection->request_role = HCI_ROLE_INVALID;
4032             hci_send_cmd(&hci_switch_role_command, connection->address, role);
4033             return true;
4034         }
4035 #endif
4036 
4037 #ifdef ENABLE_BLE
4038         switch (connection->le_con_parameter_update_state){
4039             // response to L2CAP CON PARAMETER UPDATE REQUEST
4040             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
4041                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4042                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
4043                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4044                              0x0000, 0xffff);
4045                 return true;
4046             case CON_PARAMETER_UPDATE_REPLY:
4047                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4048                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
4049                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4050                              0x0000, 0xffff);
4051                 return true;
4052             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
4053                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4054                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
4055                 return true;
4056             default:
4057                 break;
4058         }
4059         if (connection->le_phy_update_all_phys != 0xffu){
4060             uint8_t all_phys = connection->le_phy_update_all_phys;
4061             connection->le_phy_update_all_phys = 0xff;
4062             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);
4063             return true;
4064         }
4065 #endif
4066     }
4067     return false;
4068 }
4069 
4070 static void hci_run(void){
4071 
4072     bool done;
4073 
4074     // send continuation fragments first, as they block the prepared packet buffer
4075     done = hci_run_acl_fragments();
4076     if (done) return;
4077 
4078 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4079     // send host num completed packets next as they don't require num_cmd_packets > 0
4080     if (!hci_can_send_comand_packet_transport()) return;
4081     if (hci_stack->host_completed_packets){
4082         hci_host_num_completed_packets();
4083         return;
4084     }
4085 #endif
4086 
4087     if (!hci_can_send_command_packet_now()) return;
4088 
4089     // global/non-connection oriented commands
4090 
4091 
4092 #ifdef ENABLE_CLASSIC
4093     // general gap classic
4094     done = hci_run_general_gap_classic();
4095     if (done) return;
4096 #endif
4097 
4098 #ifdef ENABLE_BLE
4099     // general gap le
4100     done = hci_run_general_gap_le();
4101     if (done) return;
4102 #endif
4103 
4104     // send pending HCI commands
4105     done = hci_run_general_pending_commands();
4106     if (done) return;
4107 
4108     // stack state sub statemachines
4109     hci_connection_t * connection;
4110     switch (hci_stack->state){
4111         case HCI_STATE_INITIALIZING:
4112             hci_initializing_run();
4113             break;
4114 
4115         case HCI_STATE_HALTING:
4116 
4117             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4118             switch (hci_stack->substate){
4119                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4120                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
4121 
4122 #ifdef ENABLE_BLE
4123 #ifdef ENABLE_LE_CENTRAL
4124                     // free whitelist entries
4125                     {
4126                         btstack_linked_list_iterator_t lit;
4127                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4128                         while (btstack_linked_list_iterator_has_next(&lit)){
4129                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4130                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4131                             btstack_memory_whitelist_entry_free(entry);
4132                         }
4133                     }
4134 #endif
4135 #endif
4136                     // close all open connections
4137                     connection =  (hci_connection_t *) hci_stack->connections;
4138                     if (connection){
4139                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
4140                         if (!hci_can_send_command_packet_now()) return;
4141 
4142                         // check state
4143                         if (connection->state == SENT_DISCONNECT) return;
4144                         connection->state = SENT_DISCONNECT;
4145 
4146                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
4147 
4148                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
4149                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
4150 
4151                         // ... which would be ignored anyway as we shutdown (free) the connection now
4152                         hci_shutdown_connection(connection);
4153 
4154                         // finally, send the disconnect command
4155                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4156                         return;
4157                     }
4158 
4159                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
4160                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
4161                         log_info("HCI_STATE_HALTING: wait 50 ms");
4162                         hci_stack->substate = HCI_HALTING_W4_TIMER;
4163                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
4164                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
4165                         btstack_run_loop_add_timer(&hci_stack->timeout);
4166                         break;
4167                     }
4168 
4169                     /* fall through */
4170 
4171                 case HCI_HALTING_CLOSE:
4172                     log_info("HCI_STATE_HALTING, calling off");
4173 
4174                     // switch mode
4175                     hci_power_control_off();
4176 
4177                     log_info("HCI_STATE_HALTING, emitting state");
4178                     hci_emit_state();
4179                     log_info("HCI_STATE_HALTING, done");
4180                     break;
4181 
4182                 case HCI_HALTING_W4_TIMER:
4183                     // keep waiting
4184 
4185                     break;
4186                 default:
4187                     break;
4188             }
4189 
4190             break;
4191 
4192         case HCI_STATE_FALLING_ASLEEP:
4193             switch(hci_stack->substate) {
4194                 case HCI_FALLING_ASLEEP_DISCONNECT:
4195                     log_info("HCI_STATE_FALLING_ASLEEP");
4196                     // close all open connections
4197                     connection =  (hci_connection_t *) hci_stack->connections;
4198 
4199 #ifdef HAVE_PLATFORM_IPHONE_OS
4200                     // don't close connections, if H4 supports power management
4201                     if (btstack_control_iphone_power_management_enabled()){
4202                         connection = NULL;
4203                     }
4204 #endif
4205                     if (connection){
4206 
4207                         // send disconnect
4208                         if (!hci_can_send_command_packet_now()) return;
4209 
4210                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
4211                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4212 
4213                         // send disconnected event right away - causes higher layer connections to get closed, too.
4214                         hci_shutdown_connection(connection);
4215                         return;
4216                     }
4217 
4218                     if (hci_classic_supported()){
4219                         // disable page and inquiry scan
4220                         if (!hci_can_send_command_packet_now()) return;
4221 
4222                         log_info("HCI_STATE_HALTING, disabling inq scans");
4223                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
4224 
4225                         // continue in next sub state
4226                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
4227                         break;
4228                     }
4229 
4230                     /* fall through */
4231 
4232                 case HCI_FALLING_ASLEEP_COMPLETE:
4233                     log_info("HCI_STATE_HALTING, calling sleep");
4234 #ifdef HAVE_PLATFORM_IPHONE_OS
4235                     // don't actually go to sleep, if H4 supports power management
4236                     if (btstack_control_iphone_power_management_enabled()){
4237                         // SLEEP MODE reached
4238                         hci_stack->state = HCI_STATE_SLEEPING;
4239                         hci_emit_state();
4240                         break;
4241                     }
4242 #endif
4243                     // switch mode
4244                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
4245                     hci_emit_state();
4246                     break;
4247 
4248                 default:
4249                     break;
4250             }
4251             break;
4252 
4253         default:
4254             break;
4255     }
4256 }
4257 
4258 int hci_send_cmd_packet(uint8_t *packet, int size){
4259     // house-keeping
4260 
4261 #ifdef ENABLE_CLASSIC
4262     bd_addr_t addr;
4263     hci_connection_t * conn;
4264 #endif
4265 #ifdef ENABLE_LE_CENTRAL
4266     uint8_t initiator_filter_policy;
4267 #endif
4268 
4269     uint16_t opcode = little_endian_read_16(packet, 0);
4270     switch (opcode) {
4271         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
4272             hci_stack->loopback_mode = packet[3];
4273             break;
4274 
4275 #ifdef ENABLE_CLASSIC
4276         case HCI_OPCODE_HCI_CREATE_CONNECTION:
4277             reverse_bd_addr(&packet[3], addr);
4278             log_info("Create_connection to %s", bd_addr_to_str(addr));
4279 
4280             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4281             if (!conn) {
4282                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4283                 if (!conn) {
4284                     // notify client that alloc failed
4285                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4286                     return -1; // packet not sent to controller
4287                 }
4288                 conn->state = SEND_CREATE_CONNECTION;
4289                 conn->role  = HCI_ROLE_MASTER;
4290             }
4291             log_info("conn state %u", conn->state);
4292             switch (conn->state) {
4293                 // if connection active exists
4294                 case OPEN:
4295                     // and OPEN, emit connection complete command
4296                     hci_emit_connection_complete(addr, conn->con_handle, 0);
4297                     return -1; // packet not sent to controller
4298                 case RECEIVED_DISCONNECTION_COMPLETE:
4299                     // create connection triggered in disconnect complete event, let's do it now
4300                     break;
4301                 case SEND_CREATE_CONNECTION:
4302                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
4303                     break;
4304                 default:
4305                     // otherwise, just ignore as it is already in the open process
4306                     return -1; // packet not sent to controller
4307             }
4308             conn->state = SENT_CREATE_CONNECTION;
4309 
4310             // track outgoing connection
4311             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
4312             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
4313             break;
4314         case HCI_OPCODE_HCI_LINK_KEY_REQUEST_REPLY:
4315             hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
4316             break;
4317         case HCI_OPCODE_HCI_LINK_KEY_REQUEST_NEGATIVE_REPLY:
4318             hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
4319             break;
4320         case HCI_OPCODE_HCI_DELETE_STORED_LINK_KEY:
4321             if (hci_stack->link_key_db) {
4322                 reverse_bd_addr(&packet[3], addr);
4323                 hci_stack->link_key_db->delete_link_key(addr);
4324             }
4325             break;
4326         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
4327         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_REPLY:
4328             reverse_bd_addr(&packet[3], addr);
4329             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4330             if (conn) {
4331                 connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
4332             }
4333             break;
4334         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
4335         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_REPLY:
4336         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
4337         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_REPLY:
4338             reverse_bd_addr(&packet[3], addr);
4339             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4340             if (conn) {
4341                 connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
4342             }
4343             break;
4344 
4345 #ifdef ENABLE_SCO_OVER_HCI
4346         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
4347             // setup_synchronous_connection? Voice setting at offset 22
4348             // TODO: compare to current setting if sco connection already active
4349             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
4350             break;
4351         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
4352             // accept_synchronus_connection? Voice setting at offset 18
4353             // TODO: compare to current setting if sco connection already active
4354             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
4355             break;
4356 #endif
4357 #endif
4358 
4359 #ifdef ENABLE_BLE
4360         case HCI_OPCODE_HCI_LE_SET_RANDOM_ADDRESS:
4361             hci_stack->le_random_address_set = 1;
4362             reverse_bd_addr(&packet[3], hci_stack->le_random_address);
4363             break;
4364 #ifdef ENABLE_LE_PERIPHERAL
4365         case HCI_OPCODE_HCI_LE_SET_ADVERTISE_ENABLE:
4366             hci_stack->le_advertisements_active = packet[3];
4367             break;
4368 #endif
4369 #ifdef ENABLE_LE_CENTRAL
4370         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
4371             // white list used?
4372             initiator_filter_policy = packet[7];
4373             switch (initiator_filter_policy) {
4374                 case 0:
4375                     // whitelist not used
4376                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
4377                     break;
4378                 case 1:
4379                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
4380                     break;
4381                 default:
4382                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
4383                     break;
4384             }
4385             break;
4386         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
4387             hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
4388             break;
4389 #endif
4390 #endif
4391         default:
4392             break;
4393     }
4394 
4395     hci_stack->num_cmd_packets--;
4396 
4397     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4398     return hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4399 }
4400 
4401 // disconnect because of security block
4402 void hci_disconnect_security_block(hci_con_handle_t con_handle){
4403     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4404     if (!connection) return;
4405     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
4406 }
4407 
4408 
4409 // Configure Secure Simple Pairing
4410 
4411 #ifdef ENABLE_CLASSIC
4412 
4413 // enable will enable SSP during init
4414 void gap_ssp_set_enable(int enable){
4415     hci_stack->ssp_enable = enable;
4416 }
4417 
4418 static int hci_local_ssp_activated(void){
4419     return gap_ssp_supported() && hci_stack->ssp_enable;
4420 }
4421 
4422 // if set, BTstack will respond to io capability request using authentication requirement
4423 void gap_ssp_set_io_capability(int io_capability){
4424     hci_stack->ssp_io_capability = io_capability;
4425 }
4426 void gap_ssp_set_authentication_requirement(int authentication_requirement){
4427     hci_stack->ssp_authentication_requirement = authentication_requirement;
4428 }
4429 
4430 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
4431 void gap_ssp_set_auto_accept(int auto_accept){
4432     hci_stack->ssp_auto_accept = auto_accept;
4433 }
4434 
4435 void gap_secure_connections_enable(bool enable){
4436     hci_stack->secure_connections_enable = enable;
4437 }
4438 
4439 #endif
4440 
4441 // va_list part of hci_send_cmd
4442 int hci_send_cmd_va_arg(const hci_cmd_t *cmd, va_list argptr){
4443     if (!hci_can_send_command_packet_now()){
4444         log_error("hci_send_cmd called but cannot send packet now");
4445         return 0;
4446     }
4447 
4448     // for HCI INITIALIZATION
4449     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
4450     hci_stack->last_cmd_opcode = cmd->opcode;
4451 
4452     hci_reserve_packet_buffer();
4453     uint8_t * packet = hci_stack->hci_packet_buffer;
4454     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
4455     int err = hci_send_cmd_packet(packet, size);
4456 
4457     // release packet buffer on error or for synchronous transport implementations
4458     if ((err < 0) || hci_transport_synchronous()){
4459         hci_release_packet_buffer();
4460         hci_emit_transport_packet_sent();
4461     }
4462 
4463     return err;
4464 }
4465 
4466 /**
4467  * pre: numcmds >= 0 - it's allowed to send a command to the controller
4468  */
4469 int hci_send_cmd(const hci_cmd_t *cmd, ...){
4470     va_list argptr;
4471     va_start(argptr, cmd);
4472     int res = hci_send_cmd_va_arg(cmd, argptr);
4473     va_end(argptr);
4474     return res;
4475 }
4476 
4477 // Create various non-HCI events.
4478 // TODO: generalize, use table similar to hci_create_command
4479 
4480 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
4481     // dump packet
4482     if (dump) {
4483         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
4484     }
4485 
4486     // dispatch to all event handlers
4487     btstack_linked_list_iterator_t it;
4488     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
4489     while (btstack_linked_list_iterator_has_next(&it)){
4490         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
4491         entry->callback(HCI_EVENT_PACKET, 0, event, size);
4492     }
4493 }
4494 
4495 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
4496     if (!hci_stack->acl_packet_handler) return;
4497     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
4498 }
4499 
4500 #ifdef ENABLE_CLASSIC
4501 static void hci_notify_if_sco_can_send_now(void){
4502     // notify SCO sender if waiting
4503     if (!hci_stack->sco_waiting_for_can_send_now) return;
4504     if (hci_can_send_sco_packet_now()){
4505         hci_stack->sco_waiting_for_can_send_now = 0;
4506         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
4507         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
4508         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
4509     }
4510 }
4511 
4512 // parsing end emitting has been merged to reduce code size
4513 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
4514     uint8_t event[19+GAP_INQUIRY_MAX_NAME_LEN];
4515 
4516     uint8_t * eir_data;
4517     ad_context_t context;
4518     const uint8_t * name;
4519     uint8_t         name_len;
4520 
4521     if (size < 3) return;
4522 
4523     int event_type = hci_event_packet_get_type(packet);
4524     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
4525     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
4526 
4527     switch (event_type){
4528         case HCI_EVENT_INQUIRY_RESULT:
4529         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4530             if (size != (3 + (num_responses * 14))) return;
4531             break;
4532         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4533             if (size != 257) return;
4534             if (num_responses != 1) return;
4535             break;
4536         default:
4537             return;
4538     }
4539 
4540     // event[1] is set at the end
4541     int i;
4542     for (i=0; i<num_responses;i++){
4543         memset(event, 0, sizeof(event));
4544         event[0] = GAP_EVENT_INQUIRY_RESULT;
4545         uint8_t event_size = 18;    // if name is not set by EIR
4546 
4547         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
4548         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
4549         (void)memcpy(&event[9],
4550                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
4551                      3); // class of device
4552         (void)memcpy(&event[12],
4553                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
4554                      2); // clock offset
4555 
4556         switch (event_type){
4557             case HCI_EVENT_INQUIRY_RESULT:
4558                 // 14,15,16,17 = 0, size 18
4559                 break;
4560             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4561                 event[14] = 1;
4562                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4563                 // 16,17 = 0, size 18
4564                 break;
4565             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4566                 event[14] = 1;
4567                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4568                 // EIR packets only contain a single inquiry response
4569                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
4570                 name = NULL;
4571                 // Iterate over EIR data
4572                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
4573                     uint8_t data_type    = ad_iterator_get_data_type(&context);
4574                     uint8_t data_size    = ad_iterator_get_data_len(&context);
4575                     const uint8_t * data = ad_iterator_get_data(&context);
4576                     // Prefer Complete Local Name over Shortend Local Name
4577                     switch (data_type){
4578                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
4579                             if (name) continue;
4580                             /* fall through */
4581                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
4582                             name = data;
4583                             name_len = data_size;
4584                             break;
4585                         default:
4586                             break;
4587                     }
4588                 }
4589                 if (name){
4590                     event[16] = 1;
4591                     // truncate name if needed
4592                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
4593                     event[17] = len;
4594                     (void)memcpy(&event[18], name, len);
4595                     event_size += len;
4596                 }
4597                 break;
4598         }
4599         event[1] = event_size - 2;
4600         hci_emit_event(event, event_size, 1);
4601     }
4602 }
4603 #endif
4604 
4605 void hci_emit_state(void){
4606     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
4607     uint8_t event[3];
4608     event[0] = BTSTACK_EVENT_STATE;
4609     event[1] = sizeof(event) - 2u;
4610     event[2] = hci_stack->state;
4611     hci_emit_event(event, sizeof(event), 1);
4612 }
4613 
4614 #ifdef ENABLE_CLASSIC
4615 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4616     uint8_t event[13];
4617     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
4618     event[1] = sizeof(event) - 2;
4619     event[2] = status;
4620     little_endian_store_16(event, 3, con_handle);
4621     reverse_bd_addr(address, &event[5]);
4622     event[11] = 1; // ACL connection
4623     event[12] = 0; // encryption disabled
4624     hci_emit_event(event, sizeof(event), 1);
4625 }
4626 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
4627     if (disable_l2cap_timeouts) return;
4628     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
4629     uint8_t event[4];
4630     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
4631     event[1] = sizeof(event) - 2;
4632     little_endian_store_16(event, 2, conn->con_handle);
4633     hci_emit_event(event, sizeof(event), 1);
4634 }
4635 #endif
4636 
4637 #ifdef ENABLE_BLE
4638 #ifdef ENABLE_LE_CENTRAL
4639 static void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4640     uint8_t event[21];
4641     event[0] = HCI_EVENT_LE_META;
4642     event[1] = sizeof(event) - 2u;
4643     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
4644     event[3] = status;
4645     little_endian_store_16(event, 4, con_handle);
4646     event[6] = 0; // TODO: role
4647     event[7] = address_type;
4648     reverse_bd_addr(address, &event[8]);
4649     little_endian_store_16(event, 14, 0); // interval
4650     little_endian_store_16(event, 16, 0); // latency
4651     little_endian_store_16(event, 18, 0); // supervision timeout
4652     event[20] = 0; // master clock accuracy
4653     hci_emit_event(event, sizeof(event), 1);
4654 }
4655 #endif
4656 #endif
4657 
4658 static void hci_emit_transport_packet_sent(void){
4659     // notify upper stack that it might be possible to send again
4660     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
4661     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
4662 }
4663 
4664 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
4665     uint8_t event[6];
4666     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
4667     event[1] = sizeof(event) - 2u;
4668     event[2] = 0; // status = OK
4669     little_endian_store_16(event, 3, con_handle);
4670     event[5] = reason;
4671     hci_emit_event(event, sizeof(event), 1);
4672 }
4673 
4674 static void hci_emit_nr_connections_changed(void){
4675     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
4676     uint8_t event[3];
4677     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
4678     event[1] = sizeof(event) - 2u;
4679     event[2] = nr_hci_connections();
4680     hci_emit_event(event, sizeof(event), 1);
4681 }
4682 
4683 static void hci_emit_hci_open_failed(void){
4684     log_info("BTSTACK_EVENT_POWERON_FAILED");
4685     uint8_t event[2];
4686     event[0] = BTSTACK_EVENT_POWERON_FAILED;
4687     event[1] = sizeof(event) - 2u;
4688     hci_emit_event(event, sizeof(event), 1);
4689 }
4690 
4691 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
4692     log_info("hci_emit_dedicated_bonding_result %u ", status);
4693     uint8_t event[9];
4694     int pos = 0;
4695     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
4696     event[pos++] = sizeof(event) - 2u;
4697     event[pos++] = status;
4698     reverse_bd_addr(address, &event[pos]);
4699     hci_emit_event(event, sizeof(event), 1);
4700 }
4701 
4702 
4703 #ifdef ENABLE_CLASSIC
4704 
4705 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
4706     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
4707     uint8_t event[5];
4708     int pos = 0;
4709     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
4710     event[pos++] = sizeof(event) - 2;
4711     little_endian_store_16(event, 2, con_handle);
4712     pos += 2;
4713     event[pos++] = level;
4714     hci_emit_event(event, sizeof(event), 1);
4715 }
4716 
4717 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
4718     if (!connection) return LEVEL_0;
4719     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
4720     if ((connection->authentication_flags & CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
4721     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
4722     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
4723     // LEVEL 4 always requires 128 bit encrytion key size
4724     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
4725         security_level = LEVEL_3;
4726     }
4727     return security_level;
4728 }
4729 
4730 static void hci_emit_discoverable_enabled(uint8_t enabled){
4731     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
4732     uint8_t event[3];
4733     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
4734     event[1] = sizeof(event) - 2;
4735     event[2] = enabled;
4736     hci_emit_event(event, sizeof(event), 1);
4737 }
4738 
4739 // query if remote side supports eSCO
4740 int hci_remote_esco_supported(hci_con_handle_t con_handle){
4741     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4742     if (!connection) return 0;
4743     return (connection->remote_supported_features[0] & 1) != 0;
4744 }
4745 
4746 static bool hci_ssp_supported(hci_connection_t * connection){
4747     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
4748     return (connection->bonding_flags & mask) == mask;
4749 }
4750 
4751 // query if remote side supports SSP
4752 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
4753     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4754     if (!connection) return 0;
4755     return hci_ssp_supported(connection) ? 1 : 0;
4756 }
4757 
4758 int gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
4759     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
4760 }
4761 
4762 // GAP API
4763 /**
4764  * @bbrief enable/disable bonding. default is enabled
4765  * @praram enabled
4766  */
4767 void gap_set_bondable_mode(int enable){
4768     hci_stack->bondable = enable ? 1 : 0;
4769 }
4770 /**
4771  * @brief Get bondable mode.
4772  * @return 1 if bondable
4773  */
4774 int gap_get_bondable_mode(void){
4775     return hci_stack->bondable;
4776 }
4777 
4778 /**
4779  * @brief map link keys to security levels
4780  */
4781 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
4782     switch (link_key_type){
4783         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4784             return LEVEL_4;
4785         case COMBINATION_KEY:
4786         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4787             return LEVEL_3;
4788         default:
4789             return LEVEL_2;
4790     }
4791 }
4792 
4793 /**
4794  * @brief map link keys to secure connection yes/no
4795  */
4796 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
4797     switch (link_key_type){
4798         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4799         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4800             return 1;
4801         default:
4802             return 0;
4803     }
4804 }
4805 
4806 /**
4807  * @brief map link keys to authenticated
4808  */
4809 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
4810     switch (link_key_type){
4811         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4812         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4813             return 1;
4814         default:
4815             return 0;
4816     }
4817 }
4818 
4819 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
4820     log_info("gap_mitm_protection_required_for_security_level %u", level);
4821     return level > LEVEL_2;
4822 }
4823 
4824 /**
4825  * @brief get current security level
4826  */
4827 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
4828     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4829     if (!connection) return LEVEL_0;
4830     return gap_security_level_for_connection(connection);
4831 }
4832 
4833 /**
4834  * @brief request connection to device to
4835  * @result GAP_AUTHENTICATION_RESULT
4836  */
4837 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
4838     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4839     if (!connection){
4840         hci_emit_security_level(con_handle, LEVEL_0);
4841         return;
4842     }
4843     gap_security_level_t current_level = gap_security_level(con_handle);
4844     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
4845         requested_level, connection->requested_security_level, current_level);
4846 
4847     // assumption: earlier requested security higher than current level => security request is active
4848     if (current_level < connection->requested_security_level){
4849         if (connection->requested_security_level < requested_level){
4850             // increase requested level as new level is higher
4851 
4852             // TODO: handle re-authentication when done
4853 
4854             connection->requested_security_level = requested_level;
4855         }
4856         return;
4857     }
4858 
4859     // no request active, notify if security sufficient
4860     if (requested_level <= current_level){
4861         hci_emit_security_level(con_handle, current_level);
4862         return;
4863     }
4864 
4865     // start pairing to increase security level
4866     connection->requested_security_level = requested_level;
4867 
4868 #if 0
4869     // sending encryption request without a link key results in an error.
4870     // TODO: figure out how to use it properly
4871 
4872     // would enabling ecnryption suffice (>= LEVEL_2)?
4873     if (hci_stack->link_key_db){
4874         link_key_type_t link_key_type;
4875         link_key_t      link_key;
4876         if (hci_stack->link_key_db->get_link_key( &connection->address, &link_key, &link_key_type)){
4877             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
4878                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
4879                 return;
4880             }
4881         }
4882     }
4883 #endif
4884 
4885     // start to authenticate connection if not already active
4886     if ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
4887     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
4888     hci_run();
4889 }
4890 
4891 /**
4892  * @brief start dedicated bonding with device. disconnect after bonding
4893  * @param device
4894  * @param request MITM protection
4895  * @result GAP_DEDICATED_BONDING_COMPLETE
4896  */
4897 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
4898 
4899     // create connection state machine
4900     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
4901 
4902     if (!connection){
4903         return BTSTACK_MEMORY_ALLOC_FAILED;
4904     }
4905 
4906     // delete linkn key
4907     gap_drop_link_key_for_bd_addr(device);
4908 
4909     // configure LEVEL_2/3, dedicated bonding
4910     connection->state = SEND_CREATE_CONNECTION;
4911     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
4912     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
4913     connection->bonding_flags = BONDING_DEDICATED;
4914 
4915     // wait for GAP Security Result and send GAP Dedicated Bonding complete
4916 
4917     // handle: connnection failure (connection complete != ok)
4918     // handle: authentication failure
4919     // handle: disconnect on done
4920 
4921     hci_run();
4922 
4923     return 0;
4924 }
4925 #endif
4926 
4927 void gap_set_local_name(const char * local_name){
4928     hci_stack->local_name = local_name;
4929 }
4930 
4931 
4932 #ifdef ENABLE_BLE
4933 
4934 #ifdef ENABLE_LE_CENTRAL
4935 void gap_start_scan(void){
4936     hci_stack->le_scanning_enabled = true;
4937     hci_run();
4938 }
4939 
4940 void gap_stop_scan(void){
4941     hci_stack->le_scanning_enabled = false;
4942     hci_run();
4943 }
4944 
4945 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
4946     hci_stack->le_scan_type     = scan_type;
4947     hci_stack->le_scan_interval = scan_interval;
4948     hci_stack->le_scan_window   = scan_window;
4949     hci_run();
4950 }
4951 
4952 uint8_t gap_connect(bd_addr_t addr, bd_addr_type_t addr_type){
4953     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
4954     if (!conn){
4955         // disallow if le connection is already outgoing
4956         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
4957             log_error("le connection already active");
4958             return ERROR_CODE_COMMAND_DISALLOWED;
4959         }
4960 
4961         log_info("gap_connect: no connection exists yet, creating context");
4962         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
4963         if (!conn){
4964             // notify client that alloc failed
4965             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4966             log_info("gap_connect: failed to alloc hci_connection_t");
4967             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
4968         }
4969 
4970         // set le connecting state
4971         if (hci_is_le_connection_type(addr_type)){
4972             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
4973         }
4974 
4975         conn->state = SEND_CREATE_CONNECTION;
4976         log_info("gap_connect: send create connection next");
4977         hci_run();
4978         return ERROR_CODE_SUCCESS;
4979     }
4980 
4981     if (!hci_is_le_connection(conn) ||
4982         (conn->state == SEND_CREATE_CONNECTION) ||
4983         (conn->state == SENT_CREATE_CONNECTION)) {
4984         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
4985         log_error("gap_connect: classic connection or connect is already being created");
4986         return GATT_CLIENT_IN_WRONG_STATE;
4987     }
4988 
4989     // check if connection was just disconnected
4990     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
4991         log_info("gap_connect: send create connection (again)");
4992         conn->state = SEND_CREATE_CONNECTION;
4993         hci_run();
4994         return ERROR_CODE_SUCCESS;
4995     }
4996 
4997     log_info("gap_connect: context exists with state %u", conn->state);
4998     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
4999     hci_run();
5000     return ERROR_CODE_SUCCESS;
5001 }
5002 
5003 // @assumption: only a single outgoing LE Connection exists
5004 static hci_connection_t * gap_get_outgoing_connection(void){
5005     btstack_linked_item_t *it;
5006     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5007         hci_connection_t * conn = (hci_connection_t *) it;
5008         if (!hci_is_le_connection(conn)) continue;
5009         switch (conn->state){
5010             case SEND_CREATE_CONNECTION:
5011             case SENT_CREATE_CONNECTION:
5012             case SENT_CANCEL_CONNECTION:
5013                 return conn;
5014             default:
5015                 break;
5016         };
5017     }
5018     return NULL;
5019 }
5020 
5021 uint8_t gap_connect_cancel(void){
5022     hci_connection_t * conn = gap_get_outgoing_connection();
5023     if (!conn) return 0;
5024     switch (conn->state){
5025         case SEND_CREATE_CONNECTION:
5026             // skip sending create connection and emit event instead
5027             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5028             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5029             btstack_memory_hci_connection_free( conn );
5030             break;
5031         case SENT_CREATE_CONNECTION:
5032             // request to send cancel connection
5033             conn->state = SEND_CANCEL_CONNECTION;
5034             hci_run();
5035             break;
5036         default:
5037             break;
5038     }
5039     return 0;
5040 }
5041 #endif
5042 
5043 #ifdef ENABLE_LE_CENTRAL
5044 /**
5045  * @brief Set connection parameters for outgoing connections
5046  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5047  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5048  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5049  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5050  * @param conn_latency, default: 4
5051  * @param supervision_timeout (unit: 10ms), default: 720 ms
5052  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5053  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5054  */
5055 
5056 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5057     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5058     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5059     hci_stack->le_connection_scan_interval = conn_scan_interval;
5060     hci_stack->le_connection_scan_window = conn_scan_window;
5061     hci_stack->le_connection_interval_min = conn_interval_min;
5062     hci_stack->le_connection_interval_max = conn_interval_max;
5063     hci_stack->le_connection_latency = conn_latency;
5064     hci_stack->le_supervision_timeout = supervision_timeout;
5065     hci_stack->le_minimum_ce_length = min_ce_length;
5066     hci_stack->le_maximum_ce_length = max_ce_length;
5067 }
5068 #endif
5069 
5070 /**
5071  * @brief Updates the connection parameters for a given LE connection
5072  * @param handle
5073  * @param conn_interval_min (unit: 1.25ms)
5074  * @param conn_interval_max (unit: 1.25ms)
5075  * @param conn_latency
5076  * @param supervision_timeout (unit: 10ms)
5077  * @returns 0 if ok
5078  */
5079 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5080     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5081     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5082     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5083     connection->le_conn_interval_min = conn_interval_min;
5084     connection->le_conn_interval_max = conn_interval_max;
5085     connection->le_conn_latency = conn_latency;
5086     connection->le_supervision_timeout = supervision_timeout;
5087     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5088     hci_run();
5089     return 0;
5090 }
5091 
5092 /**
5093  * @brief Request an update of the connection parameter for a given LE connection
5094  * @param handle
5095  * @param conn_interval_min (unit: 1.25ms)
5096  * @param conn_interval_max (unit: 1.25ms)
5097  * @param conn_latency
5098  * @param supervision_timeout (unit: 10ms)
5099  * @returns 0 if ok
5100  */
5101 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5102     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5103     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5104     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5105     connection->le_conn_interval_min = conn_interval_min;
5106     connection->le_conn_interval_max = conn_interval_max;
5107     connection->le_conn_latency = conn_latency;
5108     connection->le_supervision_timeout = supervision_timeout;
5109     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5110     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5111     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5112     return 0;
5113 }
5114 
5115 #ifdef ENABLE_LE_PERIPHERAL
5116 
5117 /**
5118  * @brief Set Advertisement Data
5119  * @param advertising_data_length
5120  * @param advertising_data (max 31 octets)
5121  * @note data is not copied, pointer has to stay valid
5122  */
5123 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
5124     hci_stack->le_advertisements_data_len = advertising_data_length;
5125     hci_stack->le_advertisements_data = advertising_data;
5126     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
5127     hci_run();
5128 }
5129 
5130 /**
5131  * @brief Set Scan Response Data
5132  * @param advertising_data_length
5133  * @param advertising_data (max 31 octets)
5134  * @note data is not copied, pointer has to stay valid
5135  */
5136 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
5137     hci_stack->le_scan_response_data_len = scan_response_data_length;
5138     hci_stack->le_scan_response_data = scan_response_data;
5139     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
5140     hci_run();
5141 }
5142 
5143 /**
5144  * @brief Set Advertisement Parameters
5145  * @param adv_int_min
5146  * @param adv_int_max
5147  * @param adv_type
5148  * @param direct_address_type
5149  * @param direct_address
5150  * @param channel_map
5151  * @param filter_policy
5152  *
5153  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
5154  */
5155  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
5156     uint8_t direct_address_typ, bd_addr_t direct_address,
5157     uint8_t channel_map, uint8_t filter_policy) {
5158 
5159     hci_stack->le_advertisements_interval_min = adv_int_min;
5160     hci_stack->le_advertisements_interval_max = adv_int_max;
5161     hci_stack->le_advertisements_type = adv_type;
5162     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
5163     hci_stack->le_advertisements_channel_map = channel_map;
5164     hci_stack->le_advertisements_filter_policy = filter_policy;
5165     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
5166                  6);
5167 
5168     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5169     hci_run();
5170  }
5171 
5172 /**
5173  * @brief Enable/Disable Advertisements
5174  * @param enabled
5175  */
5176 void gap_advertisements_enable(int enabled){
5177     hci_stack->le_advertisements_enabled = enabled;
5178     hci_update_advertisements_enabled_for_current_roles();
5179     hci_run();
5180 }
5181 
5182 #endif
5183 
5184 void hci_le_set_own_address_type(uint8_t own_address_type){
5185     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
5186     if (own_address_type == hci_stack->le_own_addr_type) return;
5187     hci_stack->le_own_addr_type = own_address_type;
5188 
5189 #ifdef ENABLE_LE_PERIPHERAL
5190     // update advertisement parameters, too
5191     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5192     hci_run();
5193 #endif
5194 #ifdef ENABLE_LE_CENTRAL
5195     // note: we don't update scan parameters or modify ongoing connection attempts
5196 #endif
5197 }
5198 
5199 #endif
5200 
5201 uint8_t gap_disconnect(hci_con_handle_t handle){
5202     hci_connection_t * conn = hci_connection_for_handle(handle);
5203     if (!conn){
5204         hci_emit_disconnection_complete(handle, 0);
5205         return 0;
5206     }
5207     // ignore if already disconnected
5208     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5209         return 0;
5210     }
5211     conn->state = SEND_DISCONNECT;
5212     hci_run();
5213     return 0;
5214 }
5215 
5216 int gap_read_rssi(hci_con_handle_t con_handle){
5217     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5218     if (hci_connection == NULL) return 0;
5219     connectionSetAuthenticationFlags(hci_connection, READ_RSSI);
5220     hci_run();
5221     return 1;
5222 }
5223 
5224 /**
5225  * @brief Get connection type
5226  * @param con_handle
5227  * @result connection_type
5228  */
5229 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
5230     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5231     if (!conn) return GAP_CONNECTION_INVALID;
5232     switch (conn->address_type){
5233         case BD_ADDR_TYPE_LE_PUBLIC:
5234         case BD_ADDR_TYPE_LE_RANDOM:
5235             return GAP_CONNECTION_LE;
5236         case BD_ADDR_TYPE_SCO:
5237             return GAP_CONNECTION_SCO;
5238         case BD_ADDR_TYPE_ACL:
5239             return GAP_CONNECTION_ACL;
5240         default:
5241             return GAP_CONNECTION_INVALID;
5242     }
5243 }
5244 
5245 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
5246     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5247     if (!conn) return HCI_ROLE_INVALID;
5248     return (hci_role_t) conn->role;
5249 }
5250 
5251 
5252 #ifdef ENABLE_CLASSIC
5253 uint8_t gap_request_role(bd_addr_t addr, hci_role_t role){
5254     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5255     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5256     conn->request_role = role;
5257     hci_run();
5258     return ERROR_CODE_SUCCESS;
5259 }
5260 #endif
5261 
5262 #ifdef ENABLE_BLE
5263 
5264 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){
5265     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5266     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5267 
5268     conn->le_phy_update_all_phys    = all_phys;
5269     conn->le_phy_update_tx_phys     = tx_phys;
5270     conn->le_phy_update_rx_phys     = rx_phys;
5271     conn->le_phy_update_phy_options = phy_options;
5272 
5273     hci_run();
5274 
5275     return 0;
5276 }
5277 
5278 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, bd_addr_t address){
5279     // check capacity
5280     int num_entries = btstack_linked_list_count(&hci_stack->le_whitelist);
5281     if (num_entries >= hci_stack->le_whitelist_capacity) return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
5282     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
5283     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
5284     entry->address_type = address_type;
5285     (void)memcpy(entry->address, address, 6);
5286     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
5287     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
5288     return ERROR_CODE_SUCCESS;
5289 }
5290 
5291 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, bd_addr_t address){
5292     btstack_linked_list_iterator_t it;
5293     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5294     while (btstack_linked_list_iterator_has_next(&it)){
5295         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5296         if (entry->address_type != address_type) continue;
5297         if (memcmp(entry->address, address, 6) != 0) continue;
5298         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5299             // remove from controller if already present
5300             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5301         }  else {
5302             // directly remove entry from whitelist
5303             btstack_linked_list_iterator_remove(&it);
5304             btstack_memory_whitelist_entry_free(entry);
5305         }
5306         return ERROR_CODE_SUCCESS;
5307     }
5308     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5309 }
5310 
5311 static void hci_whitelist_clear(void){
5312     btstack_linked_list_iterator_t it;
5313     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5314     while (btstack_linked_list_iterator_has_next(&it)){
5315         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5316         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5317             // remove from controller if already present
5318             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5319             continue;
5320         }
5321         // directly remove entry from whitelist
5322         btstack_linked_list_iterator_remove(&it);
5323         btstack_memory_whitelist_entry_free(entry);
5324     }
5325 }
5326 
5327 /**
5328  * @brief Clear Whitelist
5329  * @returns 0 if ok
5330  */
5331 uint8_t gap_whitelist_clear(void){
5332     hci_whitelist_clear();
5333     hci_run();
5334     return ERROR_CODE_SUCCESS;
5335 }
5336 
5337 /**
5338  * @brief Add Device to Whitelist
5339  * @param address_typ
5340  * @param address
5341  * @returns 0 if ok
5342  */
5343 uint8_t gap_whitelist_add(bd_addr_type_t address_type, bd_addr_t address){
5344     uint8_t status = hci_whitelist_add(address_type, address);
5345     if (status){
5346         return status;
5347     }
5348     hci_run();
5349     return ERROR_CODE_SUCCESS;
5350 }
5351 
5352 /**
5353  * @brief Remove Device from Whitelist
5354  * @param address_typ
5355  * @param address
5356  * @returns 0 if ok
5357  */
5358 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, bd_addr_t address){
5359     uint8_t status = hci_whitelist_remove(address_type, address);
5360     if (status){
5361         return status;
5362     }
5363     hci_run();
5364     return ERROR_CODE_SUCCESS;
5365 }
5366 
5367 #ifdef ENABLE_LE_CENTRAL
5368 /**
5369  *  @brief Connect with Whitelist
5370  *  @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
5371  *  @returns - if ok
5372  */
5373 uint8_t gap_connect_with_whitelist(void){
5374     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5375         return ERROR_CODE_COMMAND_DISALLOWED;
5376     }
5377     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
5378     hci_run();
5379     return ERROR_CODE_SUCCESS;
5380 }
5381 
5382 /**
5383  * @brief Auto Connection Establishment - Start Connecting to device
5384  * @param address_typ
5385  * @param address
5386  * @returns 0 if ok
5387  */
5388 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, bd_addr_t address){
5389     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
5390         return ERROR_CODE_COMMAND_DISALLOWED;
5391     }
5392 
5393     uint8_t status = hci_whitelist_add(address_type, address);
5394     if (status != ERROR_CODE_SUCCESS) {
5395         return status;
5396     }
5397 
5398     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
5399 
5400     hci_run();
5401     return ERROR_CODE_SUCCESS;
5402 }
5403 
5404 /**
5405  * @brief Auto Connection Establishment - Stop Connecting to device
5406  * @param address_typ
5407  * @param address
5408  * @returns 0 if ok
5409  */
5410 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, bd_addr_t address){
5411     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
5412         return ERROR_CODE_COMMAND_DISALLOWED;
5413     }
5414 
5415     hci_whitelist_remove(address_type, address);
5416     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
5417         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5418     }
5419     hci_run();
5420     return 0;
5421 }
5422 
5423 /**
5424  * @brief Auto Connection Establishment - Stop everything
5425  * @note  Convenience function to stop all active auto connection attempts
5426  */
5427 uint8_t gap_auto_connection_stop_all(void){
5428     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
5429         return ERROR_CODE_COMMAND_DISALLOWED;
5430     }
5431     hci_whitelist_clear();
5432     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5433     hci_run();
5434     return ERROR_CODE_SUCCESS;
5435 }
5436 
5437 uint16_t gap_le_connection_interval(hci_con_handle_t connection_handle){
5438     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5439     if (!conn) return 0;
5440     return conn->le_connection_interval;
5441 }
5442 #endif
5443 #endif
5444 
5445 #ifdef ENABLE_CLASSIC
5446 /**
5447  * @brief Set Extended Inquiry Response data
5448  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
5449  * @note has to be done before stack starts up
5450  */
5451 void gap_set_extended_inquiry_response(const uint8_t * data){
5452     hci_stack->eir_data = data;
5453 }
5454 
5455 /**
5456  * @brief Start GAP Classic Inquiry
5457  * @param duration in 1.28s units
5458  * @return 0 if ok
5459  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
5460  */
5461 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
5462     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
5463     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5464     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
5465         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
5466     }
5467     hci_stack->inquiry_state = duration_in_1280ms_units;
5468     hci_run();
5469     return 0;
5470 }
5471 
5472 /**
5473  * @brief Stop GAP Classic Inquiry
5474  * @returns 0 if ok
5475  */
5476 int gap_inquiry_stop(void){
5477     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
5478         // emit inquiry complete event, before it even started
5479         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
5480         hci_emit_event(event, sizeof(event), 1);
5481         return 0;
5482     }
5483     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
5484     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
5485     hci_run();
5486     return 0;
5487 }
5488 
5489 
5490 /**
5491  * @brief Remote Name Request
5492  * @param addr
5493  * @param page_scan_repetition_mode
5494  * @param clock_offset only used when bit 15 is set
5495  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
5496  */
5497 int gap_remote_name_request(bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
5498     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5499     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
5500     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
5501     hci_stack->remote_name_clock_offset = clock_offset;
5502     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
5503     hci_run();
5504     return 0;
5505 }
5506 
5507 static int gap_pairing_set_state_and_run(bd_addr_t addr, uint8_t state){
5508     hci_stack->gap_pairing_state = state;
5509     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
5510     hci_run();
5511     return 0;
5512 }
5513 
5514 /**
5515  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
5516  * @param addr
5517  * @param pin_data
5518  * @param pin_len
5519  * @return 0 if ok
5520  */
5521 int gap_pin_code_response_binary(bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
5522     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5523     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
5524     hci_stack->gap_pairing_pin_len = pin_len;
5525     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
5526 }
5527 
5528 /**
5529  * @brief Legacy Pairing Pin Code Response
5530  * @param addr
5531  * @param pin
5532  * @return 0 if ok
5533  */
5534 int gap_pin_code_response(bd_addr_t addr, const char * pin){
5535     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
5536 }
5537 
5538 /**
5539  * @brief Abort Legacy Pairing
5540  * @param addr
5541  * @param pin
5542  * @return 0 if ok
5543  */
5544 int gap_pin_code_negative(bd_addr_t addr){
5545     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5546     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
5547 }
5548 
5549 /**
5550  * @brief SSP Passkey Response
5551  * @param addr
5552  * @param passkey
5553  * @return 0 if ok
5554  */
5555 int gap_ssp_passkey_response(bd_addr_t addr, uint32_t passkey){
5556     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5557     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
5558     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
5559 }
5560 
5561 /**
5562  * @brief Abort SSP Passkey Entry/Pairing
5563  * @param addr
5564  * @param pin
5565  * @return 0 if ok
5566  */
5567 int gap_ssp_passkey_negative(bd_addr_t addr){
5568     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5569     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
5570 }
5571 
5572 /**
5573  * @brief Accept SSP Numeric Comparison
5574  * @param addr
5575  * @param passkey
5576  * @return 0 if ok
5577  */
5578 int gap_ssp_confirmation_response(bd_addr_t addr){
5579     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5580     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
5581 }
5582 
5583 /**
5584  * @brief Abort SSP Numeric Comparison/Pairing
5585  * @param addr
5586  * @param pin
5587  * @return 0 if ok
5588  */
5589 int gap_ssp_confirmation_negative(bd_addr_t addr){
5590     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5591     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
5592 }
5593 
5594 /**
5595  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
5596  * @param inquiry_mode see bluetooth_defines.h
5597  */
5598 void hci_set_inquiry_mode(inquiry_mode_t mode){
5599     hci_stack->inquiry_mode = mode;
5600 }
5601 
5602 /**
5603  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
5604  */
5605 void hci_set_sco_voice_setting(uint16_t voice_setting){
5606     hci_stack->sco_voice_setting = voice_setting;
5607 }
5608 
5609 /**
5610  * @brief Get SCO Voice Setting
5611  * @return current voice setting
5612  */
5613 uint16_t hci_get_sco_voice_setting(void){
5614     return hci_stack->sco_voice_setting;
5615 }
5616 
5617 static int hci_have_usb_transport(void){
5618     if (!hci_stack->hci_transport) return 0;
5619     const char * transport_name = hci_stack->hci_transport->name;
5620     if (!transport_name) return 0;
5621     return (transport_name[0] == 'H') && (transport_name[1] == '2');
5622 }
5623 
5624 /** @brief Get SCO packet length for current SCO Voice setting
5625  *  @note  Using SCO packets of the exact length is required for USB transfer
5626  *  @return Length of SCO packets in bytes (not audio frames)
5627  */
5628 int hci_get_sco_packet_length(void){
5629     int sco_packet_length = 0;
5630 
5631 #ifdef ENABLE_SCO_OVER_HCI
5632 
5633     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
5634     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
5635 
5636     if (hci_have_usb_transport()){
5637         // see Core Spec for H2 USB Transfer.
5638         // 3 byte SCO header + 24 bytes per connection
5639         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
5640         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
5641     } else {
5642         // 3 byte SCO header + SCO packet size over the air (60 bytes)
5643         sco_packet_length = 3 + 60 * multiplier;
5644         // assert that it still fits inside an SCO buffer
5645         if (sco_packet_length > hci_stack->sco_data_packet_length){
5646             sco_packet_length = 3 + 60;
5647         }
5648     }
5649 #endif
5650     return sco_packet_length;
5651 }
5652 
5653 /**
5654 * @brief Sets the master/slave policy
5655 * @param policy (0: attempt to become master, 1: let connecting device decide)
5656 */
5657 void hci_set_master_slave_policy(uint8_t policy){
5658     hci_stack->master_slave_policy = policy;
5659 }
5660 
5661 #endif
5662 
5663 HCI_STATE hci_get_state(void){
5664     return hci_stack->state;
5665 }
5666 
5667 #ifdef ENABLE_CLASSIC
5668 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr)){
5669     hci_stack->gap_classic_accept_callback = accept_callback;
5670 }
5671 #endif
5672 
5673 /**
5674  * @brief Set callback for Bluetooth Hardware Error
5675  */
5676 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
5677     hci_stack->hardware_error_callback = fn;
5678 }
5679 
5680 void hci_disconnect_all(void){
5681     btstack_linked_list_iterator_t it;
5682     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5683     while (btstack_linked_list_iterator_has_next(&it)){
5684         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5685         if (con->state == SENT_DISCONNECT) continue;
5686         con->state = SEND_DISCONNECT;
5687     }
5688     hci_run();
5689 }
5690 
5691 uint16_t hci_get_manufacturer(void){
5692     return hci_stack->manufacturer;
5693 }
5694 
5695 #ifdef ENABLE_BLE
5696 
5697 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
5698     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
5699     if (!hci_con) return NULL;
5700     return &hci_con->sm_connection;
5701 }
5702 
5703 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
5704 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
5705 
5706 int gap_encryption_key_size(hci_con_handle_t con_handle){
5707     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5708     if (hci_connection == NULL) return 0;
5709     if (hci_is_le_connection(hci_connection)){
5710         sm_connection_t * sm_conn = &hci_connection->sm_connection;
5711         if (sm_conn->sm_connection_encrypted) {
5712             return sm_conn->sm_actual_encryption_key_size;
5713         }
5714     }
5715 #ifdef ENABLE_CLASSIC
5716     else {
5717         if ((hci_connection->authentication_flags & CONNECTION_ENCRYPTED)){
5718             return hci_connection->encryption_key_size;
5719         }
5720     }
5721 #endif
5722     return 0;
5723 }
5724 
5725 int gap_authenticated(hci_con_handle_t con_handle){
5726     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5727     if (hci_connection == NULL) return 0;
5728 
5729     switch (hci_connection->address_type){
5730         case BD_ADDR_TYPE_LE_PUBLIC:
5731         case BD_ADDR_TYPE_LE_RANDOM:
5732             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5733             return hci_connection->sm_connection.sm_connection_authenticated;
5734 #ifdef ENABLE_CLASSIC
5735         case BD_ADDR_TYPE_SCO:
5736         case BD_ADDR_TYPE_ACL:
5737             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
5738 #endif
5739         default:
5740             return 0;
5741     }
5742 }
5743 
5744 int gap_secure_connection(hci_con_handle_t con_handle){
5745     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5746     if (hci_connection == NULL) return 0;
5747 
5748     switch (hci_connection->address_type){
5749         case BD_ADDR_TYPE_LE_PUBLIC:
5750         case BD_ADDR_TYPE_LE_RANDOM:
5751             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5752             return hci_connection->sm_connection.sm_connection_sc;
5753 #ifdef ENABLE_CLASSIC
5754         case BD_ADDR_TYPE_SCO:
5755         case BD_ADDR_TYPE_ACL:
5756             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
5757 #endif
5758         default:
5759             return 0;
5760     }
5761 }
5762 
5763 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
5764     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
5765     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
5766     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
5767     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
5768     return sm_conn->sm_connection_authorization_state;
5769 }
5770 #endif
5771 
5772 #ifdef ENABLE_CLASSIC
5773 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){
5774     hci_connection_t * conn = hci_connection_for_handle(con_handle);
5775     if (!conn) return GAP_CONNECTION_INVALID;
5776     conn->sniff_min_interval = sniff_min_interval;
5777     conn->sniff_max_interval = sniff_max_interval;
5778     conn->sniff_attempt = sniff_attempt;
5779     conn->sniff_timeout = sniff_timeout;
5780     hci_run();
5781     return 0;
5782 }
5783 
5784 /**
5785  * @brief Exit Sniff mode
5786  * @param con_handle
5787  @ @return 0 if ok
5788  */
5789 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
5790     hci_connection_t * conn = hci_connection_for_handle(con_handle);
5791     if (!conn) return GAP_CONNECTION_INVALID;
5792     conn->sniff_min_interval = 0xffff;
5793     hci_run();
5794     return 0;
5795 }
5796 #endif
5797 
5798 void hci_halting_defer(void){
5799     if (hci_stack->state != HCI_STATE_HALTING) return;
5800     switch (hci_stack->substate){
5801         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
5802         case HCI_HALTING_CLOSE:
5803             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
5804             break;
5805         default:
5806             break;
5807     }
5808 }
5809 
5810 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
5811 void hci_setup_test_connections_fuzz(void){
5812     hci_connection_t * conn;
5813 
5814     // default address: 66:55:44:33:00:01
5815     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
5816 
5817     // setup Controller info
5818     hci_stack->num_cmd_packets = 255;
5819     hci_stack->acl_packets_total_num = 255;
5820 
5821     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
5822     addr[5] = 0x01;
5823     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5824     conn->con_handle = addr[5];
5825     conn->role  = HCI_ROLE_SLAVE;
5826     conn->state = RECEIVED_CONNECTION_REQUEST;
5827     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5828 
5829     // setup incoming Classic SCO connection with con handle 0x0002
5830     addr[5] = 0x02;
5831     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
5832     conn->con_handle = addr[5];
5833     conn->role  = HCI_ROLE_SLAVE;
5834     conn->state = RECEIVED_CONNECTION_REQUEST;
5835     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5836 
5837     // setup ready Classic ACL connection with con handle 0x0003
5838     addr[5] = 0x03;
5839     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5840     conn->con_handle = addr[5];
5841     conn->role  = HCI_ROLE_SLAVE;
5842     conn->state = OPEN;
5843     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5844 
5845     // setup ready Classic SCO connection with con handle 0x0004
5846     addr[5] = 0x04;
5847     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
5848     conn->con_handle = addr[5];
5849     conn->role  = HCI_ROLE_SLAVE;
5850     conn->state = OPEN;
5851     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5852 
5853     // setup ready LE ACL connection with con handle 0x005 and public address
5854     addr[5] = 0x05;
5855     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
5856     conn->con_handle = addr[5];
5857     conn->role  = HCI_ROLE_SLAVE;
5858     conn->state = OPEN;
5859     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5860 }
5861 
5862 void hci_free_connections_fuzz(void){
5863     btstack_linked_list_iterator_t it;
5864     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5865     while (btstack_linked_list_iterator_has_next(&it)){
5866         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5867         btstack_linked_list_iterator_remove(&it);
5868         btstack_memory_hci_connection_free(con);
5869     }
5870 }
5871 void hci_simulate_working_fuzz(void){
5872     hci_init_done();
5873     hci_stack->num_cmd_packets = 255;
5874 }
5875 #endif
5876