xref: /btstack/src/hci.c (revision 54317d10ccc672c057016d2fae6aed8490dead86)
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 BLUEKITCHEN
24  * GMBH 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 ENABLE_BLE
57 #include "gap.h"
58 #include "ble/le_device_db.h"
59 #endif
60 
61 #include <stdarg.h>
62 #include <string.h>
63 #include <inttypes.h>
64 
65 #include "btstack_debug.h"
66 #include "btstack_event.h"
67 #include "btstack_linked_list.h"
68 #include "btstack_memory.h"
69 #include "bluetooth_company_id.h"
70 #include "bluetooth_data_types.h"
71 #include "gap.h"
72 #include "hci.h"
73 #include "hci_cmd.h"
74 #include "hci_dump.h"
75 #include "ad_parser.h"
76 
77 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
78 #ifndef HCI_HOST_ACL_PACKET_NUM
79 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
80 #endif
81 #ifndef HCI_HOST_ACL_PACKET_LEN
82 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
83 #endif
84 #ifndef HCI_HOST_SCO_PACKET_NUM
85 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
86 #endif
87 #ifndef HCI_HOST_SCO_PACKET_LEN
88 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
89 #endif
90 #endif
91 
92 #if defined(ENABLE_SCO_OVER_HCI) && defined(ENABLE_SCO_OVER_PCM)
93 #error "SCO data can either be routed over HCI or over PCM, but not over both. Please only enable ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM."
94 #endif
95 
96 #if defined(ENABLE_SCO_OVER_HCI) && defined(HAVE_SCO_TRANSPORT)
97 #error "SCO data can either be routed over HCI or over PCM, but not over both. Please only enable ENABLE_SCO_OVER_HCI or HAVE_SCO_TRANSPORT."
98 #endif
99 
100 #define HCI_CONNECTION_TIMEOUT_MS 10000
101 
102 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
103 #define HCI_RESET_RESEND_TIMEOUT_MS 200
104 #endif
105 
106 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
107 #ifndef GAP_INQUIRY_MAX_NAME_LEN
108 #define GAP_INQUIRY_MAX_NAME_LEN 32
109 #endif
110 
111 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
112 #define GAP_INQUIRY_DURATION_MIN       0x01
113 #define GAP_INQUIRY_DURATION_MAX       0x30
114 #define GAP_INQUIRY_STATE_IDLE         0x00
115 #define GAP_INQUIRY_STATE_W4_ACTIVE    0x80
116 #define GAP_INQUIRY_STATE_ACTIVE       0x81
117 #define GAP_INQUIRY_STATE_W2_CANCEL    0x82
118 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x83
119 
120 // GAP Remote Name Request
121 #define GAP_REMOTE_NAME_STATE_IDLE 0
122 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
123 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
124 
125 // GAP Pairing
126 #define GAP_PAIRING_STATE_IDLE                       0
127 #define GAP_PAIRING_STATE_SEND_PIN                   1
128 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
129 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
130 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
131 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
132 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
133 #define GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE  7
134 
135 // prototypes
136 #ifdef ENABLE_CLASSIC
137 static void hci_update_scan_enable(void);
138 static void hci_emit_discoverable_enabled(uint8_t enabled);
139 static int  hci_local_ssp_activated(void);
140 static bool hci_remote_ssp_supported(hci_con_handle_t con_handle);
141 static bool hci_ssp_supported(hci_connection_t * connection);
142 static void hci_notify_if_sco_can_send_now(void);
143 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
144 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
145 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
146 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
147 static void hci_connection_timestamp(hci_connection_t *connection);
148 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
149 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
150 #endif
151 
152 static int  hci_power_control_on(void);
153 static void hci_power_control_off(void);
154 static void hci_state_reset(void);
155 static void hci_halting_timeout_handler(btstack_timer_source_t * ds);
156 static void hci_emit_transport_packet_sent(void);
157 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
158 static void hci_emit_nr_connections_changed(void);
159 static void hci_emit_hci_open_failed(void);
160 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
161 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
162 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
163 static void hci_run(void);
164 static int  hci_is_le_connection(hci_connection_t * connection);
165 
166 #ifdef ENABLE_CLASSIC
167 static int hci_have_usb_transport(void);
168 static void hci_trigger_remote_features_for_connection(hci_connection_t * connection);
169 #endif
170 
171 #ifdef ENABLE_BLE
172 #ifdef ENABLE_LE_CENTRAL
173 // called from test/ble_client/advertising_data_parser.c
174 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
175 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address);
176 static void hci_whitelist_free(void);
177 static hci_connection_t * gap_get_outgoing_connection(void);
178 #endif
179 #endif
180 
181 // the STACK is here
182 #ifndef HAVE_MALLOC
183 static hci_stack_t   hci_stack_static;
184 #endif
185 static hci_stack_t * hci_stack = NULL;
186 
187 #ifdef ENABLE_CLASSIC
188 // default name
189 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
190 
191 // test helper
192 static uint8_t disable_l2cap_timeouts = 0;
193 #endif
194 
195 // reset connection state on create and on reconnect
196 // don't overwrite addr, con handle, role
197 static void hci_connection_init(hci_connection_t * conn){
198     conn->authentication_flags = AUTH_FLAG_NONE;
199     conn->bonding_flags = 0;
200     conn->requested_security_level = LEVEL_0;
201 #ifdef ENABLE_CLASSIC
202     conn->request_role = HCI_ROLE_INVALID;
203     conn->sniff_subrating_max_latency = 0xffff;
204     conn->qos_service_type = HCI_SERVICE_TYPE_INVALID;
205     conn->link_key_type = INVALID_LINK_KEY;
206     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
207     btstack_run_loop_set_timer_context(&conn->timeout, conn);
208     hci_connection_timestamp(conn);
209 #endif
210     conn->acl_recombination_length = 0;
211     conn->acl_recombination_pos = 0;
212     conn->num_packets_sent = 0;
213 
214     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
215 #ifdef ENABLE_BLE
216     conn->le_phy_update_all_phys = 0xff;
217 #endif
218 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
219     conn->le_max_tx_octets = 27;
220 #endif
221 #ifdef ENABLE_CLASSIC_PAIRING_OOB
222     conn->classic_oob_c_192 = NULL;
223     conn->classic_oob_r_192 = NULL;
224     conn->classic_oob_c_256 = NULL;
225     conn->classic_oob_r_256 = NULL;
226 #endif
227 }
228 
229 /**
230  * create connection for given address
231  *
232  * @return connection OR NULL, if no memory left
233  */
234 static hci_connection_t * create_connection_for_bd_addr_and_type(const bd_addr_t addr, bd_addr_type_t addr_type){
235     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
236 
237     hci_connection_t * conn = btstack_memory_hci_connection_get();
238     if (!conn) return NULL;
239     hci_connection_init(conn);
240 
241     bd_addr_copy(conn->address, addr);
242     conn->address_type = addr_type;
243     conn->con_handle = HCI_CON_HANDLE_INVALID;
244     conn->role = HCI_ROLE_INVALID;
245 
246     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
247 
248     return conn;
249 }
250 
251 
252 /**
253  * get le connection parameter range
254 *
255  * @return le connection parameter range struct
256  */
257 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
258     *range = hci_stack->le_connection_parameter_range;
259 }
260 
261 /**
262  * set le connection parameter range
263  *
264  */
265 
266 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
267     hci_stack->le_connection_parameter_range = *range;
268 }
269 
270 /**
271  * @brief Test if connection parameters are inside in existing rage
272  * @param conn_interval_min (unit: 1.25ms)
273  * @param conn_interval_max (unit: 1.25ms)
274  * @param conn_latency
275  * @param supervision_timeout (unit: 10ms)
276  * @return 1 if included
277  */
278 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){
279     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
280     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
281 
282     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
283     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
284 
285     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
286     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
287 
288     return 1;
289 }
290 
291 /**
292  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
293  * @note: default: 1
294  * @param max_peripheral_connections
295  */
296 #ifdef ENABLE_LE_PERIPHERAL
297 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
298     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
299 }
300 #endif
301 
302 /**
303  * get hci connections iterator
304  *
305  * @return hci connections iterator
306  */
307 
308 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
309     btstack_linked_list_iterator_init(it, &hci_stack->connections);
310 }
311 
312 /**
313  * get connection for a given handle
314  *
315  * @return connection OR NULL, if not found
316  */
317 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
318     btstack_linked_list_iterator_t it;
319     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
320     while (btstack_linked_list_iterator_has_next(&it)){
321         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
322         if ( item->con_handle == con_handle ) {
323             return item;
324         }
325     }
326     return NULL;
327 }
328 
329 /**
330  * get connection for given address
331  *
332  * @return connection OR NULL, if not found
333  */
334 hci_connection_t * hci_connection_for_bd_addr_and_type(const bd_addr_t  addr, bd_addr_type_t addr_type){
335     btstack_linked_list_iterator_t it;
336     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
337     while (btstack_linked_list_iterator_has_next(&it)){
338         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
339         if (connection->address_type != addr_type)  continue;
340         if (memcmp(addr, connection->address, 6) != 0) continue;
341         return connection;
342     }
343     return NULL;
344 }
345 
346 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
347     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
348 }
349 
350 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
351     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
352 }
353 
354 #ifdef ENABLE_CLASSIC
355 
356 #ifdef ENABLE_SCO_OVER_HCI
357 static int hci_number_sco_connections(void){
358     int connections = 0;
359     btstack_linked_list_iterator_t it;
360     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
361     while (btstack_linked_list_iterator_has_next(&it)){
362         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
363         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
364         connections++;
365     }
366     return connections;
367 }
368 #endif
369 
370 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
371     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
372 #ifdef HAVE_EMBEDDED_TICK
373     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
374         // connections might be timed out
375         hci_emit_l2cap_check_timeout(connection);
376     }
377 #else
378     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
379         // connections might be timed out
380         hci_emit_l2cap_check_timeout(connection);
381     }
382 #endif
383 }
384 
385 static void hci_connection_timestamp(hci_connection_t *connection){
386 #ifdef HAVE_EMBEDDED_TICK
387     connection->timestamp = btstack_run_loop_embedded_get_ticks();
388 #else
389     connection->timestamp = btstack_run_loop_get_time_ms();
390 #endif
391 }
392 
393 /**
394  * add authentication flags and reset timer
395  * @note: assumes classic connection
396  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
397  */
398 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
399     bd_addr_t addr;
400     reverse_bd_addr(bd_addr, addr);
401     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
402     if (conn) {
403         connectionSetAuthenticationFlags(conn, flags);
404         hci_connection_timestamp(conn);
405     }
406 }
407 
408 static bool hci_pairing_active(hci_connection_t * hci_connection){
409     return (hci_connection->authentication_flags & AUTH_FLAG_PAIRING_ACTIVE_MASK) != 0;
410 }
411 
412 static void hci_pairing_started(hci_connection_t * hci_connection, bool ssp){
413     if (hci_pairing_active(hci_connection)) return;
414     if (ssp){
415         hci_connection->authentication_flags |= AUTH_FLAG_SSP_PAIRING_ACTIVE;
416     } else {
417         hci_connection->authentication_flags |= AUTH_FLAG_LEGACY_PAIRING_ACTIVE;
418     }
419     // if we are initiator, we have sent an HCI Authenticate Request
420     bool initiator = (hci_connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0;
421 
422     // if we are responder, use minimal service security level as required level
423     if (!initiator){
424         hci_connection->requested_security_level = (gap_security_level_t) btstack_max((uint32_t) hci_connection->requested_security_level, (uint32_t) hci_stack->gap_minimal_service_security_level);
425     }
426 
427     log_info("pairing started, ssp %u, initiator %u, requested level %u", (int) ssp, (int) initiator, hci_connection->requested_security_level);
428 
429     uint8_t event[12];
430     event[0] = GAP_EVENT_PAIRING_STARTED;
431     event[1] = 10;
432     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
433     reverse_bd_addr(hci_connection->address, &event[4]);
434     event[10] = (uint8_t) ssp;
435     event[11] = (uint8_t) initiator;
436     hci_emit_event(event, sizeof(event), 1);
437 }
438 
439 static void hci_pairing_complete(hci_connection_t * hci_connection, uint8_t status){
440     hci_connection->requested_security_level = LEVEL_0;
441     if (!hci_pairing_active(hci_connection)) return;
442     hci_connection->authentication_flags &= ~AUTH_FLAG_PAIRING_ACTIVE_MASK;
443 #ifdef ENABLE_CLASSIC_PAIRING_OOB
444     hci_connection->classic_oob_c_192 = NULL;
445     hci_connection->classic_oob_r_192 = NULL;
446     hci_connection->classic_oob_c_256 = NULL;
447     hci_connection->classic_oob_r_256 = NULL;
448 #endif
449     log_info("pairing complete, status %02x", status);
450 
451     uint8_t event[11];
452     event[0] = GAP_EVENT_PAIRING_COMPLETE;
453     event[1] = 9;
454     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
455     reverse_bd_addr(hci_connection->address, &event[4]);
456     event[10] = status;
457     hci_emit_event(event, sizeof(event), 1);
458 }
459 
460 bool hci_authentication_active_for_handle(hci_con_handle_t handle){
461     hci_connection_t * conn = hci_connection_for_handle(handle);
462     if (!conn) return false;
463     return hci_pairing_active(conn);
464 }
465 
466 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
467     if (!hci_stack->link_key_db) return;
468     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
469     hci_stack->link_key_db->delete_link_key(addr);
470 }
471 
472 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
473     if (!hci_stack->link_key_db) return;
474     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
475     hci_stack->link_key_db->put_link_key(addr, link_key, type);
476 }
477 
478 bool gap_get_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t * type){
479 	if (!hci_stack->link_key_db) return false;
480 	int result = hci_stack->link_key_db->get_link_key(addr, link_key, type) != 0;
481 	log_info("link key for %s available %u, type %u", bd_addr_to_str(addr), result, (int) *type);
482 	return result;
483 }
484 
485 void gap_delete_all_link_keys(void){
486     bd_addr_t  addr;
487     link_key_t link_key;
488     link_key_type_t type;
489     btstack_link_key_iterator_t it;
490     int ok = gap_link_key_iterator_init(&it);
491     if (!ok) {
492         log_error("could not initialize iterator");
493         return;
494     }
495     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
496         gap_drop_link_key_for_bd_addr(addr);
497     }
498     gap_link_key_iterator_done(&it);
499 }
500 
501 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
502     if (!hci_stack->link_key_db) return 0;
503     if (!hci_stack->link_key_db->iterator_init) return 0;
504     return hci_stack->link_key_db->iterator_init(it);
505 }
506 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){
507     if (!hci_stack->link_key_db) return 0;
508     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
509 }
510 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
511     if (!hci_stack->link_key_db) return;
512     hci_stack->link_key_db->iterator_done(it);
513 }
514 #endif
515 
516 static bool hci_is_le_connection_type(bd_addr_type_t address_type){
517     switch (address_type){
518         case BD_ADDR_TYPE_LE_PUBLIC:
519         case BD_ADDR_TYPE_LE_RANDOM:
520         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
521         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
522             return true;
523         default:
524             return false;
525     }
526 }
527 
528 static int hci_is_le_connection(hci_connection_t * connection){
529     return hci_is_le_connection_type(connection->address_type);
530 }
531 
532 /**
533  * count connections
534  */
535 static int nr_hci_connections(void){
536     int count = 0;
537     btstack_linked_item_t *it;
538     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
539         count++;
540     }
541     return count;
542 }
543 
544 uint16_t hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
545 
546     unsigned int num_packets_sent_classic = 0;
547     unsigned int num_packets_sent_le = 0;
548 
549     btstack_linked_item_t *it;
550     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
551         hci_connection_t * connection = (hci_connection_t *) it;
552         if (hci_is_le_connection(connection)){
553             num_packets_sent_le += connection->num_packets_sent;
554         }
555         if (connection->address_type == BD_ADDR_TYPE_ACL){
556             num_packets_sent_classic += connection->num_packets_sent;
557         }
558     }
559     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
560     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
561     int free_slots_le = 0;
562 
563     if (free_slots_classic < 0){
564         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);
565         return 0;
566     }
567 
568     if (hci_stack->le_acl_packets_total_num){
569         // if we have LE slots, they are used
570         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
571         if (free_slots_le < 0){
572             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);
573             return 0;
574         }
575     } else {
576         // otherwise, classic slots are used for LE, too
577         free_slots_classic -= num_packets_sent_le;
578         if (free_slots_classic < 0){
579             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);
580             return 0;
581         }
582     }
583 
584     switch (address_type){
585         case BD_ADDR_TYPE_UNKNOWN:
586             log_error("hci_number_free_acl_slots: unknown address type");
587             return 0;
588 
589         case BD_ADDR_TYPE_ACL:
590             return (uint16_t) free_slots_classic;
591 
592         default:
593            if (hci_stack->le_acl_packets_total_num > 0){
594                return (uint16_t) free_slots_le;
595            }
596            return (uint16_t) free_slots_classic;
597     }
598 }
599 
600 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
601     // get connection type
602     hci_connection_t * connection = hci_connection_for_handle(con_handle);
603     if (!connection){
604         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
605         return 0;
606     }
607     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
608 }
609 
610 #ifdef ENABLE_CLASSIC
611 static int hci_number_free_sco_slots(void){
612     unsigned int num_sco_packets_sent  = 0;
613     btstack_linked_item_t *it;
614     if (hci_stack->synchronous_flow_control_enabled){
615         // explicit flow control
616         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
617             hci_connection_t * connection = (hci_connection_t *) it;
618             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
619             num_sco_packets_sent += connection->num_packets_sent;
620         }
621         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
622             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
623             return 0;
624         }
625         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
626     } else {
627         // implicit flow control -- TODO
628         int num_ready = 0;
629         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
630             hci_connection_t * connection = (hci_connection_t *) it;
631             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
632             if (connection->sco_tx_ready == 0) continue;
633             num_ready++;
634         }
635         return num_ready;
636     }
637 }
638 #endif
639 
640 // only used to send HCI Host Number Completed Packets
641 static int hci_can_send_comand_packet_transport(void){
642     if (hci_stack->hci_packet_buffer_reserved) return 0;
643 
644     // check for async hci transport implementations
645     if (hci_stack->hci_transport->can_send_packet_now){
646         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
647             return 0;
648         }
649     }
650     return 1;
651 }
652 
653 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
654 bool hci_can_send_command_packet_now(void){
655     if (hci_can_send_comand_packet_transport() == 0) return false;
656     return hci_stack->num_cmd_packets > 0u;
657 }
658 
659 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
660     // check for async hci transport implementations
661     if (!hci_stack->hci_transport->can_send_packet_now) return true;
662     return hci_stack->hci_transport->can_send_packet_now(packet_type);
663 }
664 
665 static bool hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
666     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
667     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
668 }
669 
670 bool hci_can_send_acl_le_packet_now(void){
671     if (hci_stack->hci_packet_buffer_reserved) return false;
672     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
673 }
674 
675 bool hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
676     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
677     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
678 }
679 
680 bool hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
681     if (hci_stack->hci_packet_buffer_reserved) return false;
682     return hci_can_send_prepared_acl_packet_now(con_handle);
683 }
684 
685 #ifdef ENABLE_CLASSIC
686 bool hci_can_send_acl_classic_packet_now(void){
687     if (hci_stack->hci_packet_buffer_reserved) return false;
688     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
689 }
690 
691 bool hci_can_send_prepared_sco_packet_now(void){
692     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return false;
693     if (hci_have_usb_transport()){
694         return hci_stack->sco_can_send_now;
695     } else {
696         return hci_number_free_sco_slots() > 0;
697     }
698 }
699 
700 bool hci_can_send_sco_packet_now(void){
701     if (hci_stack->hci_packet_buffer_reserved) return false;
702     return hci_can_send_prepared_sco_packet_now();
703 }
704 
705 void hci_request_sco_can_send_now_event(void){
706     hci_stack->sco_waiting_for_can_send_now = 1;
707     hci_notify_if_sco_can_send_now();
708 }
709 #endif
710 
711 // used for internal checks in l2cap.c
712 bool hci_is_packet_buffer_reserved(void){
713     return hci_stack->hci_packet_buffer_reserved;
714 }
715 
716 // reserves outgoing packet buffer.
717 // @return 1 if successful
718 bool hci_reserve_packet_buffer(void){
719     if (hci_stack->hci_packet_buffer_reserved) {
720         log_error("hci_reserve_packet_buffer called but buffer already reserved");
721         return false;
722     }
723     hci_stack->hci_packet_buffer_reserved = true;
724     return true;
725 }
726 
727 void hci_release_packet_buffer(void){
728     hci_stack->hci_packet_buffer_reserved = false;
729 }
730 
731 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
732 static int hci_transport_synchronous(void){
733     return hci_stack->hci_transport->can_send_packet_now == NULL;
734 }
735 
736 static uint8_t hci_send_acl_packet_fragments(hci_connection_t *connection){
737 
738     // 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);
739 
740     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
741     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
742     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0u)){
743         max_acl_data_packet_length = hci_stack->le_data_packets_length;
744     }
745 
746 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
747     if (hci_is_le_connection(connection) && (connection->le_max_tx_octets < max_acl_data_packet_length)){
748         max_acl_data_packet_length = connection->le_max_tx_octets;
749     }
750 #endif
751 
752     log_debug("hci_send_acl_packet_fragments entered");
753 
754     uint8_t status = ERROR_CODE_SUCCESS;
755     // multiple packets could be send on a synchronous HCI transport
756     while (true){
757 
758         log_debug("hci_send_acl_packet_fragments loop entered");
759 
760         // get current data
761         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4u;
762         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
763         bool more_fragments = false;
764 
765         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
766         if (current_acl_data_packet_length > max_acl_data_packet_length){
767             more_fragments = true;
768             current_acl_data_packet_length = max_acl_data_packet_length;
769         }
770 
771         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
772         if (acl_header_pos > 0u){
773             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
774             handle_and_flags = (handle_and_flags & 0xcfffu) | (1u << 12u);
775             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
776         }
777 
778         // update header len
779         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2u, current_acl_data_packet_length);
780 
781         // count packet
782         connection->num_packets_sent++;
783         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", (int) more_fragments);
784 
785         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
786         if (more_fragments){
787             // update start of next fragment to send
788             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
789         } else {
790             // done
791             hci_stack->acl_fragmentation_pos = 0;
792             hci_stack->acl_fragmentation_total_size = 0;
793         }
794 
795         // send packet
796         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
797         const int size = current_acl_data_packet_length + 4;
798         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
799         hci_stack->acl_fragmentation_tx_active = 1;
800         int err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
801         if (err != 0){
802             // no error from HCI Transport expected
803             status = ERROR_CODE_HARDWARE_FAILURE;
804         }
805 
806         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", (int) more_fragments);
807 
808         // done yet?
809         if (!more_fragments) break;
810 
811         // can send more?
812         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return status;
813     }
814 
815     log_debug("hci_send_acl_packet_fragments loop over");
816 
817     // release buffer now for synchronous transport
818     if (hci_transport_synchronous()){
819         hci_stack->acl_fragmentation_tx_active = 0;
820         hci_release_packet_buffer();
821         hci_emit_transport_packet_sent();
822     }
823 
824     return status;
825 }
826 
827 // pre: caller has reserved the packet buffer
828 uint8_t hci_send_acl_packet_buffer(int size){
829     btstack_assert(hci_stack->hci_packet_buffer_reserved);
830 
831     uint8_t * packet = hci_stack->hci_packet_buffer;
832     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
833 
834     // check for free places on Bluetooth module
835     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
836         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
837         hci_release_packet_buffer();
838         hci_emit_transport_packet_sent();
839         return BTSTACK_ACL_BUFFERS_FULL;
840     }
841 
842     hci_connection_t *connection = hci_connection_for_handle( con_handle);
843     if (!connection) {
844         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
845         hci_release_packet_buffer();
846         hci_emit_transport_packet_sent();
847         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
848     }
849 
850 #ifdef ENABLE_CLASSIC
851     hci_connection_timestamp(connection);
852 #endif
853 
854     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
855 
856     // setup data
857     hci_stack->acl_fragmentation_total_size = size;
858     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
859 
860     return hci_send_acl_packet_fragments(connection);
861 }
862 
863 #ifdef ENABLE_CLASSIC
864 // pre: caller has reserved the packet buffer
865 uint8_t hci_send_sco_packet_buffer(int size){
866     btstack_assert(hci_stack->hci_packet_buffer_reserved);
867 
868     uint8_t * packet = hci_stack->hci_packet_buffer;
869 
870     // skip checks in loopback mode
871     if (!hci_stack->loopback_mode){
872         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
873 
874         // check for free places on Bluetooth module
875         if (!hci_can_send_prepared_sco_packet_now()) {
876             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
877             hci_release_packet_buffer();
878             hci_emit_transport_packet_sent();
879             return BTSTACK_ACL_BUFFERS_FULL;
880         }
881 
882         // track send packet in connection struct
883         hci_connection_t *connection = hci_connection_for_handle( con_handle);
884         if (!connection) {
885             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
886             hci_release_packet_buffer();
887             hci_emit_transport_packet_sent();
888             return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
889         }
890 
891         if (hci_have_usb_transport()){
892             // token used
893             hci_stack->sco_can_send_now = false;
894         } else {
895             if (hci_stack->synchronous_flow_control_enabled){
896                 connection->num_packets_sent++;
897             } else {
898                 connection->sco_tx_ready--;
899             }
900         }
901     }
902 
903     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
904 
905 #ifdef HAVE_SCO_TRANSPORT
906     hci_stack->sco_transport->send_packet(packet, size);
907     hci_release_packet_buffer();
908     hci_emit_transport_packet_sent();
909 
910     return 0;
911 #else
912     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
913     if (hci_transport_synchronous()){
914         hci_release_packet_buffer();
915         hci_emit_transport_packet_sent();
916     }
917 
918     if (err != 0){
919         return ERROR_CODE_HARDWARE_FAILURE;
920     }
921     return ERROR_CODE_SUCCESS;
922 #endif
923 }
924 #endif
925 
926 static void acl_handler(uint8_t *packet, uint16_t size){
927 
928     // get info
929     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
930     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
931     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
932     uint16_t acl_length         = READ_ACL_LENGTH(packet);
933 
934     // ignore non-registered handle
935     if (!conn){
936         log_error("acl_handler called with non-registered handle %u!" , con_handle);
937         return;
938     }
939 
940     // assert packet is complete
941     if ((acl_length + 4u) != size){
942         log_error("acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
943         return;
944     }
945 
946 #ifdef ENABLE_CLASSIC
947     // update idle timestamp
948     hci_connection_timestamp(conn);
949 #endif
950 
951 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
952     hci_stack->host_completed_packets = 1;
953     conn->num_packets_completed++;
954 #endif
955 
956     // handle different packet types
957     switch (acl_flags & 0x03u) {
958 
959         case 0x01: // continuation fragment
960 
961             // sanity checks
962             if (conn->acl_recombination_pos == 0u) {
963                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
964                 return;
965             }
966             if ((conn->acl_recombination_pos + acl_length) > (4u + HCI_ACL_BUFFER_SIZE)){
967                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
968                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
969                 conn->acl_recombination_pos = 0;
970                 return;
971             }
972 
973             // append fragment payload (header already stored)
974             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
975                          &packet[4], acl_length);
976             conn->acl_recombination_pos += acl_length;
977 
978             // forward complete L2CAP packet if complete.
979             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4u + 4u)){ // pos already incl. ACL header
980                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
981                 // reset recombination buffer
982                 conn->acl_recombination_length = 0;
983                 conn->acl_recombination_pos = 0;
984             }
985             break;
986 
987         case 0x02: { // first fragment
988 
989             // sanity check
990             if (conn->acl_recombination_pos) {
991                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
992                 conn->acl_recombination_pos = 0;
993             }
994 
995             // peek into L2CAP packet!
996             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
997 
998             // compare fragment size to L2CAP packet size
999             if (acl_length >= (l2cap_length + 4u)){
1000                 // forward fragment as L2CAP packet
1001                 hci_emit_acl_packet(packet, acl_length + 4u);
1002             } else {
1003 
1004                 if (acl_length > HCI_ACL_BUFFER_SIZE){
1005                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
1006                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
1007                     return;
1008                 }
1009 
1010                 // store first fragment and tweak acl length for complete package
1011                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
1012                              packet, acl_length + 4u);
1013                 conn->acl_recombination_pos    = acl_length + 4u;
1014                 conn->acl_recombination_length = l2cap_length;
1015                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2u, l2cap_length +4u);
1016             }
1017             break;
1018 
1019         }
1020         default:
1021             log_error( "acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
1022             return;
1023     }
1024 
1025     // execute main loop
1026     hci_run();
1027 }
1028 
1029 static void hci_connection_stop_timer(hci_connection_t * conn){
1030     btstack_run_loop_remove_timer(&conn->timeout);
1031 #ifdef ENABLE_CLASSIC
1032     btstack_run_loop_remove_timer(&conn->timeout_sco);
1033 #endif
1034 }
1035 
1036 static void hci_shutdown_connection(hci_connection_t *conn){
1037     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
1038 
1039 #ifdef ENABLE_CLASSIC
1040 #if defined(ENABLE_SCO_OVER_HCI) || defined(HAVE_SCO_TRANSPORT)
1041     bd_addr_type_t addr_type = conn->address_type;
1042 #endif
1043 #ifdef HAVE_SCO_TRANSPORT
1044     hci_con_handle_t con_handle = conn->con_handle;
1045 #endif
1046 #endif
1047 
1048     hci_connection_stop_timer(conn);
1049 
1050     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1051     btstack_memory_hci_connection_free( conn );
1052 
1053     // now it's gone
1054     hci_emit_nr_connections_changed();
1055 
1056 #ifdef ENABLE_CLASSIC
1057 #ifdef ENABLE_SCO_OVER_HCI
1058     // update SCO
1059     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->hci_transport != NULL) && (hci_stack->hci_transport->set_sco_config != NULL)){
1060         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
1061     }
1062 #endif
1063 #ifdef HAVE_SCO_TRANSPORT
1064     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->sco_transport != NULL)){
1065         hci_stack->sco_transport->close(con_handle);
1066     }
1067 #endif
1068 #endif
1069 }
1070 
1071 #ifdef ENABLE_CLASSIC
1072 
1073 static const uint16_t packet_type_sizes[] = {
1074     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
1075     HCI_ACL_DH1_SIZE, 0, 0, 0,
1076     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
1077     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
1078 };
1079 static const uint8_t  packet_type_feature_requirement_bit[] = {
1080      0, // 3 slot packets
1081      1, // 5 slot packets
1082     25, // EDR 2 mpbs
1083     26, // EDR 3 mbps
1084     39, // 3 slot EDR packts
1085     40, // 5 slot EDR packet
1086 };
1087 static const uint16_t packet_type_feature_packet_mask[] = {
1088     0x0f00, // 3 slot packets
1089     0xf000, // 5 slot packets
1090     0x1102, // EDR 2 mpbs
1091     0x2204, // EDR 3 mbps
1092     0x0300, // 3 slot EDR packts
1093     0x3000, // 5 slot EDR packet
1094 };
1095 
1096 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
1097     // enable packet types based on size
1098     uint16_t packet_types = 0;
1099     unsigned int i;
1100     for (i=0;i<16;i++){
1101         if (packet_type_sizes[i] == 0) continue;
1102         if (packet_type_sizes[i] <= buffer_size){
1103             packet_types |= 1 << i;
1104         }
1105     }
1106     // disable packet types due to missing local supported features
1107     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1108         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1109         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1110         if (feature_set) continue;
1111         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1112         packet_types &= ~packet_type_feature_packet_mask[i];
1113     }
1114     // flip bits for "may not be used"
1115     packet_types ^= 0x3306;
1116     return packet_types;
1117 }
1118 
1119 uint16_t hci_usable_acl_packet_types(void){
1120     return hci_stack->packet_types;
1121 }
1122 #endif
1123 
1124 uint8_t* hci_get_outgoing_packet_buffer(void){
1125     // hci packet buffer is >= acl data packet length
1126     return hci_stack->hci_packet_buffer;
1127 }
1128 
1129 uint16_t hci_max_acl_data_packet_length(void){
1130     return hci_stack->acl_data_packet_length;
1131 }
1132 
1133 #ifdef ENABLE_CLASSIC
1134 bool hci_extended_sco_link_supported(void){
1135     // No. 31, byte 3, bit 7
1136     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1137 }
1138 #endif
1139 
1140 bool hci_non_flushable_packet_boundary_flag_supported(void){
1141     // No. 54, byte 6, bit 6
1142     return (hci_stack->local_supported_features[6u] & (1u << 6u)) != 0u;
1143 }
1144 
1145 #ifdef ENABLE_CLASSIC
1146 static int gap_ssp_supported(void){
1147     // No. 51, byte 6, bit 3
1148     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1149 }
1150 #endif
1151 
1152 static int hci_classic_supported(void){
1153 #ifdef ENABLE_CLASSIC
1154     // No. 37, byte 4, bit 5, = No BR/EDR Support
1155     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1156 #else
1157     return 0;
1158 #endif
1159 }
1160 
1161 static int hci_le_supported(void){
1162 #ifdef ENABLE_BLE
1163     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1164     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1165 #else
1166     return 0;
1167 #endif
1168 }
1169 
1170 #ifdef ENABLE_BLE
1171 
1172 static void hci_get_own_address_for_addr_type(uint8_t own_addr_type, bd_addr_t own_addr){
1173     if (own_addr_type == BD_ADDR_TYPE_LE_PUBLIC){
1174         (void)memcpy(own_addr, hci_stack->local_bd_addr, 6);
1175     } else {
1176         (void)memcpy(own_addr, hci_stack->le_random_address, 6);
1177     }
1178 }
1179 
1180 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1181     *addr_type = hci_stack->le_own_addr_type;
1182     hci_get_own_address_for_addr_type(hci_stack->le_own_addr_type, addr);
1183 }
1184 
1185 #ifdef ENABLE_LE_PERIPHERAL
1186 void gap_le_get_own_advertisements_address(uint8_t * addr_type, bd_addr_t addr){
1187     *addr_type = hci_stack->le_advertisements_own_addr_type;
1188     hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, addr);
1189 };
1190 #endif
1191 
1192 #ifdef ENABLE_LE_CENTRAL
1193 
1194 /**
1195  * @brief Get own addr type and address used for LE connections (Central)
1196  */
1197 void gap_le_get_own_connection_address(uint8_t * addr_type, bd_addr_t addr){
1198     *addr_type = hci_stack->le_connection_own_addr_type;
1199     hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, addr);
1200 }
1201 
1202 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1203 
1204     int offset = 3;
1205     int num_reports = packet[offset];
1206     offset += 1;
1207 
1208     int i;
1209     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1210     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1211     for (i=0; (i<num_reports) && (offset < size);i++){
1212         // sanity checks on data_length:
1213         uint8_t data_length = packet[offset + 8];
1214         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1215         if ((offset + 9u + data_length + 1u) > size)    return;
1216         // setup event
1217         uint8_t event_size = 10u + data_length;
1218         int pos = 0;
1219         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1220         event[pos++] = event_size;
1221         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1222         offset += 8;
1223         pos += 8;
1224         event[pos++] = packet[offset + 1 + data_length]; // rssi
1225         event[pos++] = data_length;
1226         offset++;
1227         (void)memcpy(&event[pos], &packet[offset], data_length);
1228         pos +=    data_length;
1229         offset += data_length + 1u; // rssi
1230         hci_emit_event(event, pos, 1);
1231     }
1232 }
1233 #endif
1234 #endif
1235 
1236 #ifdef ENABLE_BLE
1237 #ifdef ENABLE_LE_PERIPHERAL
1238 static void hci_update_advertisements_enabled_for_current_roles(void){
1239     if (hci_stack->le_advertisements_enabled){
1240         // get number of active le slave connections
1241         int num_slave_connections = 0;
1242         btstack_linked_list_iterator_t it;
1243         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1244         while (btstack_linked_list_iterator_has_next(&it)){
1245             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1246             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1247             if (con->state != OPEN) continue;
1248             if (con->role  != HCI_ROLE_SLAVE) continue;
1249             if (!hci_is_le_connection(con)) continue;
1250             num_slave_connections++;
1251         }
1252         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1253         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1254     } else {
1255         hci_stack->le_advertisements_enabled_for_current_roles = false;
1256     }
1257 }
1258 #endif
1259 #endif
1260 
1261 #ifdef ENABLE_CLASSIC
1262 static void gap_run_set_local_name(void){
1263     hci_reserve_packet_buffer();
1264     uint8_t * packet = hci_stack->hci_packet_buffer;
1265     // construct HCI Command and send
1266     uint16_t opcode = hci_write_local_name.opcode;
1267     hci_stack->last_cmd_opcode = opcode;
1268     packet[0] = opcode & 0xff;
1269     packet[1] = opcode >> 8;
1270     packet[2] = DEVICE_NAME_LEN;
1271     memset(&packet[3], 0, DEVICE_NAME_LEN);
1272     uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1273     uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1274     // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1275     (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1276     // expand '00:00:00:00:00:00' in name with bd_addr
1277     btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1278     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1279 }
1280 
1281 static void gap_run_set_eir_data(void){
1282     hci_reserve_packet_buffer();
1283     uint8_t * packet = hci_stack->hci_packet_buffer;
1284     // construct HCI Command in-place and send
1285     uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1286     hci_stack->last_cmd_opcode = opcode;
1287     uint16_t offset = 0;
1288     packet[offset++] = opcode & 0xff;
1289     packet[offset++] = opcode >> 8;
1290     packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1291     packet[offset++] = 0;  // FEC not required
1292     memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1293     if (hci_stack->eir_data){
1294         // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1295         ad_context_t context;
1296         for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1297             uint8_t data_type   = ad_iterator_get_data_type(&context);
1298             uint8_t size        = ad_iterator_get_data_len(&context);
1299             const uint8_t *data = ad_iterator_get_data(&context);
1300             // copy item
1301             packet[offset++] = size + 1;
1302             packet[offset++] = data_type;
1303             memcpy(&packet[offset], data, size);
1304             // update name item
1305             if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1306                 btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1307             }
1308             offset += size;
1309         }
1310     } else {
1311         uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1312         uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1313         packet[offset++] = bytes_to_copy + 1;
1314         packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1315         (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1316         // expand '00:00:00:00:00:00' in name with bd_addr
1317         btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1318     }
1319     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1320 }
1321 
1322 static void hci_run_gap_tasks_classic(void){
1323     if ((hci_stack->gap_tasks & GAP_TASK_SET_CLASS_OF_DEVICE) != 0) {
1324         hci_stack->gap_tasks &= ~GAP_TASK_SET_CLASS_OF_DEVICE;
1325         hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1326         return;
1327     }
1328     if ((hci_stack->gap_tasks & GAP_TASK_SET_LOCAL_NAME) != 0) {
1329         hci_stack->gap_tasks &= ~GAP_TASK_SET_LOCAL_NAME;
1330         gap_run_set_local_name();
1331         return;
1332     }
1333     if ((hci_stack->gap_tasks & GAP_TASK_SET_EIR_DATA) != 0) {
1334         hci_stack->gap_tasks &= ~GAP_TASK_SET_EIR_DATA;
1335         gap_run_set_eir_data();
1336         return;
1337     }
1338     if ((hci_stack->gap_tasks & GAP_TASK_SET_DEFAULT_LINK_POLICY) != 0) {
1339         hci_stack->gap_tasks &= ~GAP_TASK_SET_DEFAULT_LINK_POLICY;
1340         hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1341         return;
1342     }
1343     // write page scan activity
1344     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY) != 0) {
1345         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
1346         hci_send_cmd(&hci_write_page_scan_activity, hci_stack->new_page_scan_interval, hci_stack->new_page_scan_window);
1347         return;
1348     }
1349     // write page scan type
1350     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_TYPE) != 0) {
1351         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_TYPE;
1352         hci_send_cmd(&hci_write_page_scan_type, hci_stack->new_page_scan_type);
1353         return;
1354     }
1355     // write page timeout
1356     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_TIMEOUT) != 0) {
1357         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_TIMEOUT;
1358         hci_send_cmd(&hci_write_page_timeout, hci_stack->page_timeout);
1359         return;
1360     }
1361     // send scan enable
1362     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_SCAN_ENABLE) != 0) {
1363         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_SCAN_ENABLE;
1364         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1365         return;
1366     }
1367     // send write scan activity
1368     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_INQUIRY_SCAN_ACTIVITY) != 0) {
1369         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_INQUIRY_SCAN_ACTIVITY;
1370         hci_send_cmd(&hci_write_inquiry_scan_activity, hci_stack->inquiry_scan_interval, hci_stack->inquiry_scan_window);
1371         return;
1372     }
1373 }
1374 #endif
1375 
1376 #ifndef HAVE_HOST_CONTROLLER_API
1377 
1378 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1379     if (!hci_stack->config) return 0;
1380     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1381     // Limit baud rate for Broadcom chipsets to 3 mbps
1382     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1383         baud_rate = 3000000;
1384     }
1385     return baud_rate;
1386 }
1387 
1388 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1389     UNUSED(ds);
1390 
1391     switch (hci_stack->substate){
1392         case HCI_INIT_W4_SEND_RESET:
1393             log_info("Resend HCI Reset");
1394             hci_stack->substate = HCI_INIT_SEND_RESET;
1395             hci_stack->num_cmd_packets = 1;
1396             hci_run();
1397             break;
1398         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1399             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1400             if (hci_stack->hci_transport->reset_link){
1401                 hci_stack->hci_transport->reset_link();
1402             }
1403 
1404             /* fall through */
1405 
1406         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1407             log_info("Resend HCI Reset - CSR Warm Boot");
1408             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1409             hci_stack->num_cmd_packets = 1;
1410             hci_run();
1411             break;
1412         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1413             if (hci_stack->hci_transport->set_baudrate){
1414                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1415                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1416                 hci_stack->hci_transport->set_baudrate(baud_rate);
1417             }
1418             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1419             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1420                 if (hci_stack->hci_transport->reset_link){
1421                     log_info("Link Reset");
1422                     hci_stack->hci_transport->reset_link();
1423                 }
1424                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1425                 hci_run();
1426             }
1427             break;
1428         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1429             // otherwise continue
1430             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1431             hci_send_cmd(&hci_read_local_supported_commands);
1432             break;
1433         default:
1434             break;
1435     }
1436 }
1437 #endif
1438 
1439 static void hci_initializing_next_state(void){
1440     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1441 }
1442 
1443 static void hci_init_done(void){
1444     // done. tell the app
1445     log_info("hci_init_done -> HCI_STATE_WORKING");
1446     hci_stack->state = HCI_STATE_WORKING;
1447     hci_emit_state();
1448 }
1449 
1450 // assumption: hci_can_send_command_packet_now() == true
1451 static void hci_initializing_run(void){
1452     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1453 
1454     if (!hci_can_send_command_packet_now()) return;
1455 
1456 #ifndef HAVE_HOST_CONTROLLER_API
1457     bool need_baud_change = hci_stack->config
1458             && hci_stack->chipset
1459             && hci_stack->chipset->set_baudrate_command
1460             && hci_stack->hci_transport->set_baudrate
1461             && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1462 #endif
1463 
1464     switch (hci_stack->substate){
1465         case HCI_INIT_SEND_RESET:
1466             hci_state_reset();
1467 
1468 #ifndef HAVE_HOST_CONTROLLER_API
1469             // prepare reset if command complete not received in 100ms
1470             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1471             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1472             btstack_run_loop_add_timer(&hci_stack->timeout);
1473 #endif
1474             // send command
1475             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1476             hci_send_cmd(&hci_reset);
1477             break;
1478         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1479             hci_send_cmd(&hci_read_local_version_information);
1480             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1481             break;
1482 
1483 #ifndef HAVE_HOST_CONTROLLER_API
1484         case HCI_INIT_SEND_READ_LOCAL_NAME:
1485             hci_send_cmd(&hci_read_local_name);
1486             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1487             break;
1488         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1489             hci_state_reset();
1490             // prepare reset if command complete not received in 100ms
1491             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1492             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1493             btstack_run_loop_add_timer(&hci_stack->timeout);
1494             // send command
1495             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1496             hci_send_cmd(&hci_reset);
1497             break;
1498         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1499             hci_state_reset();
1500             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1501             hci_send_cmd(&hci_reset);
1502             break;
1503         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1504             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1505             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1506             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1507             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1508             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1509             break;
1510         }
1511         case HCI_INIT_SET_BD_ADDR:
1512             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1513             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1514             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1515             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1516             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1517             break;
1518         case HCI_INIT_SEND_BAUD_CHANGE:
1519             if (need_baud_change) {
1520                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1521                 hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1522                 hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1523                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1524                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1525                 // STLC25000D: baudrate change happens within 0.5 s after command was send,
1526                 // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1527                 if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1528                     btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1529                     btstack_run_loop_add_timer(&hci_stack->timeout);
1530                }
1531                break;
1532             }
1533 
1534             /* fall through */
1535 
1536         case HCI_INIT_CUSTOM_INIT:
1537             // Custom initialization
1538             if (hci_stack->chipset && hci_stack->chipset->next_command){
1539                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1540                 bool send_cmd = false;
1541                 switch (hci_stack->chipset_result){
1542                     case BTSTACK_CHIPSET_VALID_COMMAND:
1543                         send_cmd = true;
1544                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1545                         break;
1546                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1547                         send_cmd = true;
1548                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1549                         log_info("CSR Warm Boot");
1550                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1551                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1552                         btstack_run_loop_add_timer(&hci_stack->timeout);
1553                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1554                             && hci_stack->config
1555                             && hci_stack->chipset
1556                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1557                             && hci_stack->hci_transport->set_baudrate
1558                             && hci_transport_uart_get_main_baud_rate()){
1559                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1560                         } else {
1561                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1562                         }
1563                         break;
1564                     default:
1565                         break;
1566                 }
1567 
1568                 if (send_cmd){
1569                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1570                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1571                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1572                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1573                     break;
1574                 }
1575                 log_info("Init script done");
1576 
1577                 // Init script download on Broadcom chipsets causes:
1578                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1579                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1580                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1581 
1582                     // - baud rate to reset, restore UART baud rate if needed
1583                     if (need_baud_change) {
1584                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1585                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1586                         hci_stack->hci_transport->set_baudrate(baud_rate);
1587                     }
1588 
1589                     uint16_t bcm_delay_ms = 300;
1590                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1591                     //   -> Work around: wait here.
1592                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1593                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1594                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1595                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1596                     btstack_run_loop_add_timer(&hci_stack->timeout);
1597                     break;
1598                 }
1599             }
1600 #endif
1601             /* fall through */
1602 
1603         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1604             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1605             hci_send_cmd(&hci_read_local_supported_commands);
1606             break;
1607         case HCI_INIT_READ_BD_ADDR:
1608             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1609             hci_send_cmd(&hci_read_bd_addr);
1610             break;
1611         case HCI_INIT_READ_BUFFER_SIZE:
1612             // only read buffer size if supported
1613             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1614                 hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1615                 hci_send_cmd(&hci_read_buffer_size);
1616                 break;
1617             }
1618 
1619             /* fall through */
1620 
1621         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1622             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1623             hci_send_cmd(&hci_read_local_supported_features);
1624             break;
1625 
1626 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1627         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1628             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1629             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1630             break;
1631         case HCI_INIT_HOST_BUFFER_SIZE:
1632             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1633             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1634                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1635             break;
1636 #endif
1637 
1638         case HCI_INIT_SET_EVENT_MASK:
1639             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1640             if (hci_le_supported()){
1641                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x3FFFFFFFU);
1642             } else {
1643                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1644                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x1FFFFFFFU);
1645             }
1646             break;
1647 
1648 #ifdef ENABLE_CLASSIC
1649         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1650             if (hci_classic_supported() && gap_ssp_supported()){
1651                 hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1652                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1653                 break;
1654             }
1655 
1656             /* fall through */
1657 
1658         case HCI_INIT_WRITE_INQUIRY_MODE:
1659             if (hci_classic_supported()){
1660                 hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1661                 hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1662                 break;
1663             }
1664 
1665             /* fall through */
1666 
1667         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1668             // skip write secure connections host support if not supported or disabled
1669             if (hci_classic_supported() && hci_stack->secure_connections_enable && (hci_stack->local_supported_commands[1u] & 0x02u) != 0u) {
1670                 hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1671                 hci_stack->secure_connections_active = true;
1672                 hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1673                 break;
1674             }
1675 
1676 #ifdef ENABLE_SCO_OVER_HCI
1677             /* fall through */
1678 
1679         // only sent if ENABLE_SCO_OVER_HCI is defined
1680         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1681             // skip write synchronous flow control if not supported
1682             if (hci_classic_supported() && ((hci_stack->local_supported_commands[0] & 0x04) != 0)){
1683                 hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1684                 hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1685                 break;
1686             }
1687             /* fall through */
1688 
1689         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1690             // skip write default erroneous data reporting if not supported
1691             if (hci_classic_supported() && ((hci_stack->local_supported_commands[0] & 0x08) != 0)){
1692                 hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1693                 hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1694                 break;
1695             }
1696 #endif
1697 
1698 #if defined(ENABLE_SCO_OVER_HCI) || defined(ENABLE_SCO_OVER_PCM)
1699             /* fall through */
1700 
1701         // only sent if manufacturer is Broadcom and ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM is defined
1702         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1703             if (hci_classic_supported() && (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)){
1704                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1705 #ifdef ENABLE_SCO_OVER_HCI
1706                 log_info("BCM: Route SCO data via HCI transport");
1707                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1708 #endif
1709 #ifdef ENABLE_SCO_OVER_PCM
1710                 log_info("BCM: Route SCO data via PCM interface");
1711 #ifdef ENABLE_BCM_PCM_WBS
1712                 // 512 kHz bit clock for 2 channels x 16 bit x 16 kHz
1713                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 2, 0, 1, 1);
1714 #else
1715                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1716                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 1, 0, 1, 1);
1717 #endif
1718 #endif
1719                 break;
1720             }
1721 #endif
1722 
1723 #ifdef ENABLE_SCO_OVER_PCM
1724             /* fall through */
1725 
1726         case HCI_INIT_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
1727             if (hci_classic_supported() && (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)){
1728                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1729                 log_info("BCM: Config PCM interface for I2S");
1730 #ifdef ENABLE_BCM_PCM_WBS
1731                 // 512 kHz bit clock for 2 channels x 16 bit x 8 kHz
1732                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 2);
1733 #else
1734                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1735                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 1);
1736 #endif
1737                 break;
1738             }
1739 #endif
1740 #endif
1741 
1742 #ifdef ENABLE_BLE
1743             /* fall through */
1744 
1745         // LE INIT
1746         case HCI_INIT_LE_READ_BUFFER_SIZE:
1747             if (hci_le_supported()){
1748                 hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1749                 hci_send_cmd(&hci_le_read_buffer_size);
1750                 break;
1751             }
1752 
1753             /* fall through */
1754 
1755         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1756             // skip write le host if not supported (e.g. on LE only EM9301)
1757             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x02u) != 0)){
1758                 // LE Supported Host = 1, Simultaneous Host = 0
1759                 hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1760                 hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1761                 break;
1762             }
1763 
1764             /* fall through */
1765 
1766         case HCI_INIT_LE_SET_EVENT_MASK:
1767             if (hci_le_supported()){
1768                 hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1769                 hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1770                 break;
1771             }
1772 #endif
1773 
1774 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1775             /* fall through */
1776 
1777         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1778             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u)){
1779                 hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1780                 hci_send_cmd(&hci_le_read_maximum_data_length);
1781                 break;
1782             }
1783 
1784             /* fall through */
1785 
1786         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1787             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u)){
1788                 hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1789                 hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1790                 break;
1791             }
1792 #endif
1793 
1794 #ifdef ENABLE_LE_CENTRAL
1795             /* fall through */
1796 
1797         case HCI_INIT_READ_WHITE_LIST_SIZE:
1798             if (hci_le_supported()){
1799                 hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1800                 hci_send_cmd(&hci_le_read_white_list_size);
1801                 break;
1802             }
1803 
1804             /* fall through */
1805 
1806         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1807             if (hci_le_supported()){
1808                 hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1809                 hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
1810                 break;
1811             }
1812 #endif
1813 
1814             /* fall through */
1815 
1816         case HCI_INIT_DONE:
1817             hci_stack->substate = HCI_INIT_DONE;
1818 #ifdef ENABLE_CLASSIC
1819             // init sequence complete, check if GAP Tasks are completed
1820             if (hci_stack->gap_tasks != 0) {
1821                 hci_run_gap_tasks_classic();
1822                 break;
1823             }
1824 #endif
1825             hci_init_done();
1826             break;
1827 
1828         default:
1829             return;
1830     }
1831 }
1832 
1833 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1834     bool command_completed = false;
1835     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1836         uint16_t opcode = little_endian_read_16(packet,3);
1837         if (opcode == hci_stack->last_cmd_opcode){
1838             command_completed = true;
1839             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1840         } else {
1841             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1842         }
1843     }
1844 
1845     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1846         uint8_t  status = packet[2];
1847         uint16_t opcode = little_endian_read_16(packet,4);
1848         if (opcode == hci_stack->last_cmd_opcode){
1849             if (status){
1850                 command_completed = true;
1851                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1852             } else {
1853                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1854             }
1855         } else {
1856             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1857         }
1858     }
1859 #ifndef HAVE_HOST_CONTROLLER_API
1860     // Vendor == CSR
1861     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1862         // TODO: track actual command
1863         command_completed = true;
1864     }
1865 
1866     // Vendor == Toshiba
1867     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1868         // TODO: track actual command
1869         command_completed = true;
1870         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1871         hci_stack->num_cmd_packets = 1;
1872     }
1873 #endif
1874 
1875     return command_completed;
1876 }
1877 
1878 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1879 
1880     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1881 
1882     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1883 
1884 #ifndef HAVE_HOST_CONTROLLER_API
1885 
1886     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1887     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1888     //
1889     // HCI Reset
1890     // Timeout 100 ms
1891     // HCI Reset
1892     // Command Complete Reset
1893     // HCI Read Local Version Information
1894     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1895     // hang...
1896     //
1897     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1898     if (!command_completed
1899             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1900             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1901 
1902         uint16_t opcode = little_endian_read_16(packet,3);
1903         if (opcode == hci_reset.opcode){
1904             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1905             return;
1906         }
1907     }
1908 
1909     // CSR & H5
1910     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1911     if (!command_completed
1912             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1913             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1914 
1915         uint16_t opcode = little_endian_read_16(packet,3);
1916         if (opcode == hci_reset.opcode){
1917             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1918             return;
1919         }
1920     }
1921 
1922     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1923     // fix: Correct substate and behave as command below
1924     if (command_completed){
1925         switch (hci_stack->substate){
1926             case HCI_INIT_SEND_RESET:
1927                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1928                 break;
1929             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1930                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1931                 break;
1932             default:
1933                 break;
1934         }
1935     }
1936 
1937 #endif
1938 
1939     if (!command_completed) return;
1940 
1941     bool need_baud_change = false;
1942     bool need_addr_change = false;
1943 
1944 #ifndef HAVE_HOST_CONTROLLER_API
1945     need_baud_change = hci_stack->config
1946                         && hci_stack->chipset
1947                         && hci_stack->chipset->set_baudrate_command
1948                         && hci_stack->hci_transport->set_baudrate
1949                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1950 
1951     need_addr_change = hci_stack->custom_bd_addr_set
1952                         && hci_stack->chipset
1953                         && hci_stack->chipset->set_bd_addr_command;
1954 #endif
1955 
1956     switch(hci_stack->substate){
1957 
1958 #ifndef HAVE_HOST_CONTROLLER_API
1959         case HCI_INIT_SEND_RESET:
1960             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1961             // fix: just correct substate and behave as command below
1962 
1963             /* fall through */
1964 #endif
1965 
1966         case HCI_INIT_W4_SEND_RESET:
1967             btstack_run_loop_remove_timer(&hci_stack->timeout);
1968             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1969             return;
1970 
1971 #ifndef HAVE_HOST_CONTROLLER_API
1972         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1973             // for STLC2500D, baud rate change already happened.
1974             // for others, baud rate gets changed now
1975             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1976                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1977                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1978                 hci_stack->hci_transport->set_baudrate(baud_rate);
1979             }
1980             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1981             return;
1982         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1983             btstack_run_loop_remove_timer(&hci_stack->timeout);
1984             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1985             return;
1986         case HCI_INIT_W4_CUSTOM_INIT:
1987             // repeat custom init
1988             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1989             return;
1990 #endif
1991 
1992         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1993             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1994               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1995                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1996                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1997                 return;
1998             }
1999             if (need_addr_change){
2000                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
2001                 return;
2002             }
2003             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2004             return;
2005 #ifndef HAVE_HOST_CONTROLLER_API
2006         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
2007             if (need_baud_change){
2008                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
2009                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
2010                 hci_stack->hci_transport->set_baudrate(baud_rate);
2011             }
2012             if (need_addr_change){
2013                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
2014                 return;
2015             }
2016             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2017             return;
2018         case HCI_INIT_W4_SET_BD_ADDR:
2019             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
2020             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
2021             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
2022                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
2023                 return;
2024             }
2025             // skipping st warm boot
2026             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2027             return;
2028         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
2029             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2030             return;
2031 #endif
2032 
2033         case HCI_INIT_DONE:
2034             // set state if we came here by fall through
2035             hci_stack->substate = HCI_INIT_DONE;
2036             return;
2037 
2038         default:
2039             break;
2040     }
2041     hci_initializing_next_state();
2042 }
2043 
2044 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
2045     // CC2564C might emit Connection Complete for rejected incoming SCO connection
2046     // To prevent accidentally free'ing the CHI connection for the ACL connection,
2047     // check if the hci connection has been outgoing
2048     switch (conn->state){
2049         case SEND_CREATE_CONNECTION:
2050         case RECEIVED_CONNECTION_REQUEST:
2051             break;
2052         default:
2053             return;
2054     }
2055 
2056     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
2057     bd_addr_t bd_address;
2058     (void)memcpy(&bd_address, conn->address, 6);
2059 
2060 #ifdef ENABLE_CLASSIC
2061     // cache needed data
2062     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
2063 #endif
2064 
2065     // connection failed, remove entry
2066     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2067     btstack_memory_hci_connection_free( conn );
2068 
2069 #ifdef ENABLE_CLASSIC
2070     // notify client if dedicated bonding
2071     if (notify_dedicated_bonding_failed){
2072         log_info("hci notify_dedicated_bonding_failed");
2073         hci_emit_dedicated_bonding_result(bd_address, status);
2074     }
2075 
2076     // if authentication error, also delete link key
2077     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
2078         gap_drop_link_key_for_bd_addr(bd_address);
2079     }
2080 #else
2081     UNUSED(status);
2082 #endif
2083 }
2084 
2085 #ifdef ENABLE_CLASSIC
2086 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
2087     // SSP Controller
2088     if (features[6] & (1 << 3)){
2089         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
2090     }
2091     // eSCO
2092     if (features[3] & (1<<7)){
2093         conn->remote_supported_features[0] |= 1;
2094     }
2095     // Extended features
2096     if (features[7] & (1<<7)){
2097         conn->remote_supported_features[0] |= 2;
2098     }
2099 }
2100 
2101 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
2102     // SSP Host
2103     if (features[0] & (1 << 0)){
2104         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
2105     }
2106     // SC Host
2107     if (features[0] & (1 << 3)){
2108         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
2109     }
2110 }
2111 
2112 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
2113     // SC Controller
2114     if (features[1] & (1 << 0)){
2115         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2116     }
2117 }
2118 
2119 static void hci_handle_remote_features_received(hci_connection_t * conn){
2120     conn->bonding_flags &= ~BONDING_REMOTE_FEATURES_QUERY_ACTIVE;
2121     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
2122     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
2123     if (conn->bonding_flags & BONDING_DEDICATED){
2124         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2125     }
2126 }
2127 static bool hci_remote_sc_enabled(hci_connection_t * connection){
2128     const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2129     return (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
2130 }
2131 
2132 #endif
2133 
2134 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
2135     // handle BT initialization
2136     if (hci_stack->state == HCI_STATE_INITIALIZING) {
2137         hci_initializing_event_handler(packet, size);
2138     }
2139 
2140     // help with BT sleep
2141     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
2142         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
2143         && (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable))) {
2144         hci_initializing_next_state();
2145     }
2146 }
2147 
2148 #ifdef ENABLE_CLASSIC
2149 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
2150     conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2151     conn->encryption_key_size = encryption_key_size;
2152 
2153     if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) != 0) {
2154         conn->requested_security_level = LEVEL_0;
2155         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
2156         return;
2157     }
2158 
2159     // Request remote features if not already done
2160     hci_trigger_remote_features_for_connection(conn);
2161 
2162     // Request Authentication if not already done
2163     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
2164     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2165 }
2166 #endif
2167 
2168 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
2169     UNUSED(size);
2170 
2171     uint16_t manufacturer;
2172 #ifdef ENABLE_CLASSIC
2173     hci_con_handle_t handle;
2174     hci_connection_t * conn;
2175     uint8_t status;
2176 #endif
2177     // get num cmd packets - limit to 1 to reduce complexity
2178     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2179 
2180     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
2181     switch (opcode){
2182         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
2183             if (packet[5]) break;
2184             // terminate, name 248 chars
2185             packet[6+248] = 0;
2186             log_info("local name: %s", &packet[6]);
2187             break;
2188         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2189             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2190             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2191                 uint16_t acl_len = little_endian_read_16(packet, 6);
2192                 uint16_t sco_len = packet[8];
2193 
2194                 // determine usable ACL/SCO payload size
2195                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2196                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2197 
2198                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2199                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2200 
2201                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2202                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2203                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2204             }
2205             break;
2206         case HCI_OPCODE_HCI_READ_RSSI:
2207             if (packet[5] == ERROR_CODE_SUCCESS){
2208                 uint8_t event[5];
2209                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2210                 event[1] = 3;
2211                 (void)memcpy(&event[2], &packet[6], 3);
2212                 hci_emit_event(event, sizeof(event), 1);
2213             }
2214             break;
2215 #ifdef ENABLE_BLE
2216         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2217             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2218             hci_stack->le_acl_packets_total_num = packet[8];
2219             // determine usable ACL payload size
2220             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2221                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2222             }
2223             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2224             break;
2225 #endif
2226 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2227         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2228             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2229             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2230             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);
2231             break;
2232 #endif
2233 #ifdef ENABLE_LE_CENTRAL
2234         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2235             hci_stack->le_whitelist_capacity = packet[6];
2236             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2237             break;
2238 #endif
2239         case HCI_OPCODE_HCI_READ_BD_ADDR:
2240             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2241             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));
2242 #ifdef ENABLE_CLASSIC
2243             if (hci_stack->link_key_db){
2244                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2245             }
2246 #endif
2247             break;
2248 #ifdef ENABLE_CLASSIC
2249         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2250             hci_emit_discoverable_enabled(hci_stack->discoverable);
2251             break;
2252         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2253             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2254                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2255                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2256                 hci_emit_event(event, sizeof(event), 1);
2257             }
2258             break;
2259 #endif
2260         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2261             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2262 
2263 #ifdef ENABLE_CLASSIC
2264             // determine usable ACL packet types based on host buffer size and supported features
2265             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2266             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2267 #endif
2268             // Classic/LE
2269             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2270             break;
2271         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2272             manufacturer = little_endian_read_16(packet, 10);
2273             // map Cypress to Broadcom
2274             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2275                 log_info("Treat Cypress as Broadcom");
2276                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2277                 little_endian_store_16(packet, 10, manufacturer);
2278             }
2279             hci_stack->manufacturer = manufacturer;
2280             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2281             break;
2282         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2283             hci_stack->local_supported_commands[0] =
2284                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit  0 = Octet 14, bit 7 / Read Buffer Size
2285                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit  1 = Octet 24, bit 6 / Write Le Host Supported
2286                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit  2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2287                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     )  |  // bit  3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2288                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit  4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2289                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit  5 = Octet 35, bit 3 / LE Read Maximum Data Length
2290                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit  6 = Octet 35, bit 5 / LE Set Default PHY
2291                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit  7 = Octet 20, bit 4 / Read Encryption Key Size
2292             hci_stack->local_supported_commands[1] =
2293                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit  8 = Octet  2, bit 6 / Read Remote Extended Features
2294                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u) |  // bit  9 = Octet 32, bit 3 / Write Secure Connections Host
2295                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x02u) << 1u) |  // bit 10 = Octet 35, bit 1 / LE Set Address Resolution Enable
2296                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x02u) << 2u) |  // bit 11 = Octet 32, bit 1 / Remote OOB Extended Data Request Reply
2297                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x40u) >> 2u);   // bit 12 = Octet 32, bit 6 / Read Local OOB Extended Data command
2298             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2299             break;
2300 #ifdef ENABLE_CLASSIC
2301         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2302             if (packet[5]) return;
2303             hci_stack->synchronous_flow_control_enabled = 1;
2304             break;
2305         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2306             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2307             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2308             conn   = hci_connection_for_handle(handle);
2309             if (conn != NULL) {
2310                 uint8_t key_size = 0;
2311                 if (status == 0){
2312                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2313                     log_info("Handle %04x key Size: %u", handle, key_size);
2314                 } else {
2315                     key_size = 1;
2316                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2317                 }
2318                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2319             }
2320             break;
2321         // assert pairing complete event is emitted.
2322         // note: for SSP, Simple Pairing Complete Event is sufficient, but we want to be more robust
2323         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
2324         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
2325         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
2326             hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
2327             // lookup connection by gap pairing addr
2328             conn = hci_connection_for_bd_addr_and_type(hci_stack->gap_pairing_addr, BD_ADDR_TYPE_ACL);
2329             if (conn == NULL) break;
2330             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2331             break;
2332 
2333 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2334         case HCI_OPCODE_HCI_READ_LOCAL_OOB_DATA:
2335         case HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA:{
2336             uint8_t event[67];
2337             event[0] = GAP_EVENT_LOCAL_OOB_DATA;
2338             event[1] = 65;
2339             (void)memset(&event[2], 0, 65);
2340             if (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE] == ERROR_CODE_SUCCESS){
2341                 (void)memcpy(&event[3], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 32);
2342                 if (opcode == HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA){
2343                     event[2] = 3;
2344                     (void)memcpy(&event[35], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+33], 32);
2345                 } else {
2346                     event[2] = 1;
2347                 }
2348             }
2349             hci_emit_event(event, sizeof(event), 0);
2350             break;
2351         }
2352 
2353         // note: only needed if user does not provide OOB data
2354         case HCI_OPCODE_HCI_REMOTE_OOB_DATA_REQUEST_NEGATIVE_REPLY:
2355             conn = hci_connection_for_handle(hci_stack->classic_oob_con_handle);
2356             hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
2357             if (conn == NULL) break;
2358             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2359             break;
2360 #endif
2361 #endif
2362         default:
2363             break;
2364     }
2365 }
2366 
2367 #ifdef ENABLE_BLE
2368 static void event_handle_le_connection_complete(const uint8_t * packet){
2369 	bd_addr_t addr;
2370 	bd_addr_type_t addr_type;
2371 	hci_connection_t * conn;
2372 
2373 	// Connection management
2374 	reverse_bd_addr(&packet[8], addr);
2375 	addr_type = (bd_addr_type_t)packet[7];
2376 	log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2377 	conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2378 
2379 #ifdef ENABLE_LE_CENTRAL
2380 	// handle error: error is reported only to the initiator -> outgoing connection
2381 	if (packet[3]){
2382 
2383 		// handle cancelled outgoing connection
2384 		// "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2385 		//  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2386 		//  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2387 		if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2388 		    // reset state
2389             hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2390             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2391 			// get outgoing connection conn struct for direct connect
2392 			conn = gap_get_outgoing_connection();
2393 		}
2394 
2395 		// outgoing le connection establishment is done
2396 		if (conn){
2397 			// remove entry
2398 			btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2399 			btstack_memory_hci_connection_free( conn );
2400 		}
2401 		return;
2402 	}
2403 #endif
2404 
2405 	// on success, both hosts receive connection complete event
2406 	if (packet[6] == HCI_ROLE_MASTER){
2407 #ifdef ENABLE_LE_CENTRAL
2408 		// if we're master on an le connection, it was an outgoing connection and we're done with it
2409 		// note: no hci_connection_t object exists yet for connect with whitelist
2410 		if (hci_is_le_connection_type(addr_type)){
2411 			hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2412 			hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2413 		}
2414 #endif
2415 	} else {
2416 #ifdef ENABLE_LE_PERIPHERAL
2417 		// if we're slave, it was an incoming connection, advertisements have stopped
2418 		hci_stack->le_advertisements_active = false;
2419 #endif
2420 	}
2421 
2422 	// LE connections are auto-accepted, so just create a connection if there isn't one already
2423 	if (!conn){
2424 		conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2425 	}
2426 
2427 	// no memory, sorry.
2428 	if (!conn){
2429 		return;
2430 	}
2431 
2432 	conn->state = OPEN;
2433 	conn->role  = packet[6];
2434 	conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2435 	conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2436 
2437 #ifdef ENABLE_LE_PERIPHERAL
2438 	if (packet[6] == HCI_ROLE_SLAVE){
2439 		hci_update_advertisements_enabled_for_current_roles();
2440 	}
2441 #endif
2442 
2443     // init unenhanced att bearer mtu
2444     conn->att_connection.mtu = ATT_DEFAULT_MTU;
2445     conn->att_connection.mtu_exchanged = false;
2446 
2447     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2448 
2449 	// restart timer
2450 	// btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2451 	// btstack_run_loop_add_timer(&conn->timeout);
2452 
2453 	log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2454 
2455 	hci_emit_nr_connections_changed();
2456 }
2457 #endif
2458 
2459 #ifdef ENABLE_CLASSIC
2460 static bool hci_ssp_security_level_possible_for_io_cap(gap_security_level_t level, uint8_t io_cap_local, uint8_t io_cap_remote){
2461     if (io_cap_local == SSP_IO_CAPABILITY_UNKNOWN) return false;
2462     // LEVEL_4 is tested by l2cap
2463     // LEVEL 3 requires MITM protection -> check io capabilities if Authenticated is possible
2464     // @see: Core Spec v5.3, Vol 3, Part C, Table 5.7
2465     if (level >= LEVEL_3){
2466         // MITM not possible without keyboard or display
2467         if (io_cap_remote >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2468         if (io_cap_local  >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2469 
2470         // MITM possible if one side has keyboard and the other has keyboard or display
2471         if (io_cap_remote == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2472         if (io_cap_local  == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2473 
2474         // MITM not possible if one side has only display and other side has no keyboard
2475         if (io_cap_remote == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2476         if (io_cap_local  == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2477     }
2478     // LEVEL 2 requires SSP, which is a given
2479     return true;
2480 }
2481 
2482 static bool btstack_is_null(uint8_t * data, uint16_t size){
2483     uint16_t i;
2484     for (i=0; i < size ; i++){
2485         if (data[i] != 0) {
2486             return false;
2487         }
2488     }
2489     return true;
2490 }
2491 
2492 static void hci_ssp_assess_security_on_io_cap_request(hci_connection_t * conn){
2493     // get requested security level
2494     gap_security_level_t requested_security_level = conn->requested_security_level;
2495     if (hci_stack->gap_secure_connections_only_mode){
2496         requested_security_level = LEVEL_4;
2497     }
2498 
2499     // assess security: LEVEL 4 requires SC
2500     // skip this preliminary test if remote features are not available yet to work around potential issue in ESP32 controller
2501     if ((requested_security_level == LEVEL_4) &&
2502         ((conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0) &&
2503         !hci_remote_sc_enabled(conn)){
2504         log_info("Level 4 required, but SC not supported -> abort");
2505         hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2506         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2507         return;
2508     }
2509 
2510     // assess security based on io capabilities
2511     if (conn->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
2512         // responder: fully validate io caps of both sides as well as OOB data
2513         bool security_possible = false;
2514         security_possible = hci_ssp_security_level_possible_for_io_cap(requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io);
2515 
2516 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2517         // We assume that both Controller can reach LEVEL 4, if one side has received P-192 and the other has received P-256,
2518         // so we merge the OOB data availability
2519         uint8_t have_oob_data = conn->io_cap_response_oob_data;
2520         if (conn->classic_oob_c_192 != NULL){
2521             have_oob_data |= 1;
2522         }
2523         if (conn->classic_oob_c_256 != NULL){
2524             have_oob_data |= 2;
2525         }
2526         // for up to Level 3, either P-192 as well as P-256 will do
2527         // if we don't support SC, then a) conn->classic_oob_c_256 will be NULL and b) remote should not report P-256 available
2528         // if remote does not SC, we should not receive P-256 data either
2529         if ((requested_security_level <= LEVEL_3) && (have_oob_data != 0)){
2530             security_possible = true;
2531         }
2532         // for Level 4, P-256 is needed
2533         if ((requested_security_level == LEVEL_4 && ((have_oob_data & 2) != 0))){
2534             security_possible = true;
2535         }
2536 #endif
2537 
2538         if (security_possible == false){
2539             log_info("IOCap/OOB insufficient for level %u -> abort", requested_security_level);
2540             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2541             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2542             return;
2543         }
2544     } else {
2545         // initiator: remote io cap not yet, only check if we have ability for MITM protection if requested and OOB is not supported
2546 #ifndef ENABLE_CLASSIC_PAIRING_OOB
2547 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2548         if ((conn->requested_security_level >= LEVEL_3) && (hci_stack->ssp_io_capability >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT)){
2549             log_info("Level 3+ required, but no input/output -> abort");
2550             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2551             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2552             return;
2553         }
2554 #endif
2555 #endif
2556     }
2557 
2558 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2559     if (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN){
2560         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
2561     } else {
2562         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2563     }
2564 #endif
2565 }
2566 
2567 #endif
2568 
2569 static void event_handler(uint8_t *packet, uint16_t size){
2570 
2571     uint16_t event_length = packet[1];
2572 
2573     // assert packet is complete
2574     if (size != (event_length + 2u)){
2575         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2576         return;
2577     }
2578 
2579     bd_addr_type_t addr_type;
2580     hci_con_handle_t handle;
2581     hci_connection_t * conn;
2582     int i;
2583     int create_connection_cmd;
2584 
2585 #ifdef ENABLE_CLASSIC
2586     hci_link_type_t link_type;
2587     bd_addr_t addr;
2588 #endif
2589 
2590     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2591 
2592     switch (hci_event_packet_get_type(packet)) {
2593 
2594         case HCI_EVENT_COMMAND_COMPLETE:
2595             handle_command_complete_event(packet, size);
2596             break;
2597 
2598         case HCI_EVENT_COMMAND_STATUS:
2599             // get num cmd packets - limit to 1 to reduce complexity
2600             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2601 
2602             // check command status to detected failed outgoing connections
2603             create_connection_cmd = 0;
2604 #ifdef ENABLE_CLASSIC
2605             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2606                 create_connection_cmd = 1;
2607             }
2608             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_accept_synchronous_connection)){
2609                 create_connection_cmd = 1;
2610             }
2611 #endif
2612 #ifdef ENABLE_LE_CENTRAL
2613             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2614                 create_connection_cmd = 1;
2615             }
2616 #endif
2617             if (create_connection_cmd) {
2618                 uint8_t status = hci_event_command_status_get_status(packet);
2619                 addr_type = hci_stack->outgoing_addr_type;
2620                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, addr_type);
2621                 log_info("command status (create connection), status %x, connection %p, addr %s, type %x", status, conn, bd_addr_to_str(hci_stack->outgoing_addr), addr_type);
2622 
2623                 // reset outgoing address info
2624                 memset(hci_stack->outgoing_addr, 0, 6);
2625                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2626 
2627                 // on error
2628                 if (status != ERROR_CODE_SUCCESS){
2629 #ifdef ENABLE_LE_CENTRAL
2630                     if (hci_is_le_connection_type(addr_type)){
2631                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2632                         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2633                     }
2634 #endif
2635                     // error => outgoing connection failed
2636                     if (conn != NULL){
2637                         hci_handle_connection_failed(conn, status);
2638                     }
2639                 }
2640             }
2641 
2642 #ifdef ENABLE_CLASSIC
2643             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_inquiry)) {
2644                 uint8_t status = hci_event_command_status_get_status(packet);
2645                 log_info("command status (inquiry), status %x", status);
2646                 if (status == ERROR_CODE_SUCCESS) {
2647                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
2648                 } else {
2649                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2650                 }
2651             }
2652 #endif
2653             break;
2654 
2655         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2656             if (size < 3) return;
2657             uint16_t num_handles = packet[2];
2658             if (size != (3u + num_handles * 4u)) return;
2659             uint16_t offset = 3;
2660             for (i=0; i<num_handles;i++){
2661                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2662                 offset += 2u;
2663                 uint16_t num_packets = little_endian_read_16(packet, offset);
2664                 offset += 2u;
2665 
2666                 conn = hci_connection_for_handle(handle);
2667                 if (!conn){
2668                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2669                     continue;
2670                 }
2671 
2672                 if (conn->num_packets_sent >= num_packets){
2673                     conn->num_packets_sent -= num_packets;
2674                 } else {
2675                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2676                     conn->num_packets_sent = 0;
2677                 }
2678                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2679 
2680 #ifdef ENABLE_CLASSIC
2681                 // For SCO, we do the can_send_now_check here
2682                 hci_notify_if_sco_can_send_now();
2683 #endif
2684             }
2685             break;
2686         }
2687 
2688 #ifdef ENABLE_CLASSIC
2689         case HCI_EVENT_INQUIRY_COMPLETE:
2690             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2691                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2692                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2693                 hci_emit_event(event, sizeof(event), 1);
2694             }
2695             break;
2696         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2697             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2698                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2699             }
2700             break;
2701         case HCI_EVENT_CONNECTION_REQUEST:
2702             reverse_bd_addr(&packet[2], addr);
2703             link_type = (hci_link_type_t) packet[11];
2704 
2705             // CVE-2020-26555: reject incoming connection from device with same BD ADDR
2706             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0){
2707                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2708                 bd_addr_copy(hci_stack->decline_addr, addr);
2709                 break;
2710             }
2711 
2712             if (hci_stack->gap_classic_accept_callback != NULL){
2713                 if ((*hci_stack->gap_classic_accept_callback)(addr, link_type) == 0){
2714                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2715                     bd_addr_copy(hci_stack->decline_addr, addr);
2716                     break;
2717                 }
2718             }
2719 
2720             // TODO: eval COD 8-10
2721             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), (unsigned int) link_type);
2722             addr_type = (link_type == HCI_LINK_TYPE_ACL) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2723             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2724             if (!conn) {
2725                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2726             }
2727             if (!conn) {
2728                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2729                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2730                 bd_addr_copy(hci_stack->decline_addr, addr);
2731                 hci_run();
2732                 // avoid event to higher layer
2733                 return;
2734             }
2735             conn->role  = HCI_ROLE_SLAVE;
2736             conn->state = RECEIVED_CONNECTION_REQUEST;
2737             // store info about eSCO
2738             if (link_type == HCI_LINK_TYPE_ESCO){
2739                 conn->remote_supported_features[0] |= 1;
2740             }
2741             hci_run();
2742             break;
2743 
2744         case HCI_EVENT_CONNECTION_COMPLETE:
2745             // Connection management
2746             reverse_bd_addr(&packet[5], addr);
2747             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2748             addr_type = BD_ADDR_TYPE_ACL;
2749             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2750             if (conn) {
2751                 if (!packet[2]){
2752                     conn->state = OPEN;
2753                     conn->con_handle = little_endian_read_16(packet, 3);
2754 
2755                     // queue set supervision timeout if we're master
2756                     if ((hci_stack->link_supervision_timeout != HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT) && (conn->role == HCI_ROLE_MASTER)){
2757                         connectionSetAuthenticationFlags(conn, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
2758                     }
2759 
2760                     // restart timer
2761                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2762                     btstack_run_loop_add_timer(&conn->timeout);
2763 
2764                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2765 
2766                     hci_emit_nr_connections_changed();
2767                 } else {
2768                     // connection failed
2769                     hci_handle_connection_failed(conn, packet[2]);
2770                 }
2771             }
2772             break;
2773 
2774         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2775             reverse_bd_addr(&packet[5], addr);
2776             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2777             log_info("Synchronous Connection Complete for %p (status=%u) %s", conn, packet[2], bd_addr_to_str(addr));
2778             if (packet[2]){
2779                 // connection failed
2780                 if (conn){
2781                     hci_handle_connection_failed(conn, packet[2]);
2782                 }
2783                 break;
2784             }
2785             if (!conn) {
2786                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2787             }
2788             if (!conn) {
2789                 break;
2790             }
2791             conn->state = OPEN;
2792             conn->con_handle = little_endian_read_16(packet, 3);
2793 
2794 #ifdef ENABLE_SCO_OVER_HCI
2795             // update SCO
2796             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2797                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2798             }
2799             // trigger can send now
2800             if (hci_have_usb_transport()){
2801                 hci_stack->sco_can_send_now = true;
2802             }
2803 #endif
2804 #ifdef HAVE_SCO_TRANSPORT
2805             // configure sco transport
2806             if (hci_stack->sco_transport != NULL){
2807                 sco_format_t sco_format = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? SCO_FORMAT_8_BIT : SCO_FORMAT_16_BIT;
2808                 hci_stack->sco_transport->open(conn->con_handle, sco_format);
2809             }
2810 #endif
2811             break;
2812 
2813         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2814             handle = little_endian_read_16(packet, 3);
2815             conn = hci_connection_for_handle(handle);
2816             if (!conn) break;
2817             if (!packet[2]){
2818                 const uint8_t * features = &packet[5];
2819                 hci_handle_remote_features_page_0(conn, features);
2820 
2821                 // read extended features if possible
2822                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2823                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2824                     break;
2825                 }
2826             }
2827             hci_handle_remote_features_received(conn);
2828             break;
2829 
2830         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2831             handle = little_endian_read_16(packet, 3);
2832             conn = hci_connection_for_handle(handle);
2833             if (!conn) break;
2834             // status = ok, page = 1
2835             if (!packet[2]) {
2836                 uint8_t page_number = packet[5];
2837                 uint8_t maximum_page_number = packet[6];
2838                 const uint8_t * features = &packet[7];
2839                 bool done = false;
2840                 switch (page_number){
2841                     case 1:
2842                         hci_handle_remote_features_page_1(conn, features);
2843                         if (maximum_page_number >= 2){
2844                             // get Secure Connections (Controller) from Page 2 if available
2845                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2846                         } else {
2847                             // otherwise, assume SC (Controller) == SC (Host)
2848                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2849                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2850                             }
2851                             done = true;
2852                         }
2853                         break;
2854                     case 2:
2855                         hci_handle_remote_features_page_2(conn, features);
2856                         done = true;
2857                         break;
2858                     default:
2859                         break;
2860                 }
2861                 if (!done) break;
2862             }
2863             hci_handle_remote_features_received(conn);
2864             break;
2865 
2866         case HCI_EVENT_LINK_KEY_REQUEST:
2867 #ifndef ENABLE_EXPLICIT_LINK_KEY_REPLY
2868             hci_event_link_key_request_get_bd_addr(packet, addr);
2869             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2870             if (!conn) break;
2871 
2872             // lookup link key in db if not cached
2873             if ((conn->link_key_type == INVALID_LINK_KEY) && (hci_stack->link_key_db != NULL)){
2874                 hci_stack->link_key_db->get_link_key(conn->address, conn->link_key, &conn->link_key_type);
2875             }
2876 
2877             // response sent by hci_run()
2878             conn->authentication_flags |= AUTH_FLAG_HANDLE_LINK_KEY_REQUEST;
2879 #endif
2880             break;
2881 
2882         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2883             hci_event_link_key_request_get_bd_addr(packet, addr);
2884             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2885             if (!conn) break;
2886 
2887             hci_pairing_complete(conn, ERROR_CODE_SUCCESS);
2888 
2889             // CVE-2020-26555: ignore NULL link key
2890             // default link_key_type = INVALID_LINK_KEY asserts that NULL key won't be used for encryption
2891             if (btstack_is_null(&packet[8], 16)) break;
2892 
2893             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2894             // Change Connection Encryption keeps link key type
2895             if (link_key_type != CHANGED_COMBINATION_KEY){
2896                 conn->link_key_type = link_key_type;
2897             }
2898 
2899             // cache link key. link keys stored in little-endian format for legacy reasons
2900             memcpy(&conn->link_key, &packet[8], 16);
2901 
2902             // only store link key:
2903             // - if bondable enabled
2904             if (hci_stack->bondable == false) break;
2905             // - if security level sufficient
2906             if (gap_security_level_for_link_key_type(link_key_type) < conn->requested_security_level) break;
2907             // - for SSP, also check if remote side requested bonding as well
2908             if (conn->link_key_type != COMBINATION_KEY){
2909                 bool remote_bonding = conn->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2910                 if (!remote_bonding){
2911                     break;
2912                 }
2913             }
2914             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2915             break;
2916         }
2917 
2918         case HCI_EVENT_PIN_CODE_REQUEST:
2919             hci_event_pin_code_request_get_bd_addr(packet, addr);
2920             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2921             if (!conn) break;
2922 
2923             hci_pairing_started(conn, false);
2924             // abort pairing if: non-bondable mode (pin code request is not forwarded to app)
2925             if (!hci_stack->bondable ){
2926                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2927                 hci_pairing_complete(conn, ERROR_CODE_PAIRING_NOT_ALLOWED);
2928                 hci_run();
2929                 return;
2930             }
2931             // abort pairing if: LEVEL_4 required (pin code request is not forwarded to app)
2932             if ((hci_stack->gap_secure_connections_only_mode) || (conn->requested_security_level == LEVEL_4)){
2933                 log_info("Level 4 required, but SC not supported -> abort");
2934                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2935                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2936                 hci_run();
2937                 return;
2938             }
2939             break;
2940 
2941         case HCI_EVENT_IO_CAPABILITY_RESPONSE:
2942             hci_event_io_capability_response_get_bd_addr(packet, addr);
2943             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2944             if (!conn) break;
2945 
2946             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE);
2947             hci_pairing_started(conn, true);
2948             conn->io_cap_response_auth_req = hci_event_io_capability_response_get_authentication_requirements(packet);
2949             conn->io_cap_response_io       = hci_event_io_capability_response_get_io_capability(packet);
2950 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2951             conn->io_cap_response_oob_data = hci_event_io_capability_response_get_oob_data_present(packet);
2952 #endif
2953             break;
2954 
2955         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2956             hci_event_io_capability_response_get_bd_addr(packet, addr);
2957             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2958             if (!conn) break;
2959 
2960             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
2961             hci_connection_timestamp(conn);
2962             hci_pairing_started(conn, true);
2963             break;
2964 
2965 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2966         case HCI_EVENT_REMOTE_OOB_DATA_REQUEST:
2967             hci_event_remote_oob_data_request_get_bd_addr(packet, addr);
2968             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2969             if (!conn) break;
2970 
2971             hci_connection_timestamp(conn);
2972 
2973             hci_pairing_started(conn, true);
2974 
2975             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
2976             break;
2977 #endif
2978 
2979         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2980             hci_event_user_confirmation_request_get_bd_addr(packet, addr);
2981             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2982             if (!conn) break;
2983             if (hci_ssp_security_level_possible_for_io_cap(conn->requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io)) {
2984                 if (hci_stack->ssp_auto_accept){
2985                     hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
2986                 };
2987             } else {
2988                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2989                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
2990                 // don't forward event to app
2991                 hci_run();
2992                 return;
2993             }
2994             break;
2995 
2996         case HCI_EVENT_USER_PASSKEY_REQUEST:
2997             // Pairing using Passkey results in MITM protection. If Level 4 is required, support for SC is validated on IO Cap Request
2998             if (hci_stack->ssp_auto_accept){
2999                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
3000             };
3001             break;
3002 
3003         case HCI_EVENT_MODE_CHANGE:
3004             handle = hci_event_mode_change_get_handle(packet);
3005             conn = hci_connection_for_handle(handle);
3006             if (!conn) break;
3007             conn->connection_mode = hci_event_mode_change_get_mode(packet);
3008             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
3009             break;
3010 #endif
3011 
3012         case HCI_EVENT_ENCRYPTION_CHANGE:
3013             handle = hci_event_encryption_change_get_connection_handle(packet);
3014             conn = hci_connection_for_handle(handle);
3015             if (!conn) break;
3016             if (hci_event_encryption_change_get_status(packet) == 0u) {
3017                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
3018                 if (encryption_enabled){
3019                     if (hci_is_le_connection(conn)){
3020                         // For LE, we accept connection as encrypted
3021                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
3022                     }
3023 #ifdef ENABLE_CLASSIC
3024                     else {
3025 
3026                         // dedicated bonding: send result and disconnect
3027                         if (conn->bonding_flags & BONDING_DEDICATED){
3028                             conn->bonding_flags &= ~BONDING_DEDICATED;
3029                             conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
3030                             conn->bonding_status = packet[2];
3031                             break;
3032                         }
3033 
3034                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
3035                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
3036                         bool connected_uses_aes_ccm = encryption_enabled == 2;
3037                         if (hci_stack->secure_connections_active && sc_used_during_pairing && !connected_uses_aes_ccm){
3038                             log_info("SC during pairing, but only E0 now -> abort");
3039                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
3040                             break;
3041                         }
3042 
3043                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
3044                         if (connected_uses_aes_ccm){
3045                             conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3046                         }
3047 
3048 #ifdef ENABLE_TESTING_SUPPORT
3049                         // work around for issue with PTS dongle
3050                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3051 #endif
3052 
3053                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
3054                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
3055                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3056                         } else {
3057                             // if not, pretend everything is perfect
3058                             hci_handle_read_encryption_key_size_complete(conn, 16);
3059                         }
3060                     }
3061 #endif
3062                 } else {
3063                     conn->authentication_flags &= ~AUTH_FLAG_CONNECTION_ENCRYPTED;
3064                 }
3065             }
3066 
3067             break;
3068 
3069 #ifdef ENABLE_CLASSIC
3070         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
3071             handle = hci_event_authentication_complete_get_connection_handle(packet);
3072             conn = hci_connection_for_handle(handle);
3073             if (!conn) break;
3074 
3075             // clear authentication active flag
3076             conn->bonding_flags &= ~BONDING_SENT_AUTHENTICATE_REQUEST;
3077             hci_pairing_complete(conn, hci_event_authentication_complete_get_status(packet));
3078 
3079             // authenticated only if auth status == 0
3080             if (hci_event_authentication_complete_get_status(packet) == 0){
3081                 // authenticated
3082                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3083 
3084                 // If not already encrypted, start encryption
3085                 if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0){
3086                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3087                     break;
3088                 }
3089             }
3090 
3091             // emit updated security level
3092             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
3093             break;
3094 
3095         case HCI_EVENT_SIMPLE_PAIRING_COMPLETE:
3096             hci_event_simple_pairing_complete_get_bd_addr(packet, addr);
3097             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3098             if (!conn) break;
3099 
3100             // treat successfully paired connection as authenticated
3101             if (hci_event_simple_pairing_complete_get_status(packet) == ERROR_CODE_SUCCESS){
3102                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3103             }
3104 
3105             hci_pairing_complete(conn, hci_event_simple_pairing_complete_get_status(packet));
3106             break;
3107 #endif
3108 
3109         // HCI_EVENT_DISCONNECTION_COMPLETE
3110         // has been split, to first notify stack before shutting connection down
3111         // see end of function, too.
3112         case HCI_EVENT_DISCONNECTION_COMPLETE:
3113             if (packet[2]) break;   // status != 0
3114             handle = little_endian_read_16(packet, 3);
3115             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
3116             if (hci_stack->acl_fragmentation_total_size > 0u) {
3117                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
3118                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
3119                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
3120                     hci_stack->acl_fragmentation_total_size = 0;
3121                     hci_stack->acl_fragmentation_pos = 0;
3122                     if (release_buffer){
3123                         hci_release_packet_buffer();
3124                     }
3125                 }
3126             }
3127 
3128             conn = hci_connection_for_handle(handle);
3129             if (!conn) break;
3130 #ifdef ENABLE_CLASSIC
3131             // pairing failed if it was ongoing
3132             hci_pairing_complete(conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3133 #endif
3134 
3135             // emit dedicatd bonding event
3136             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
3137                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
3138             }
3139 
3140             // mark connection for shutdown, stop timers, reset state
3141             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
3142             hci_connection_stop_timer(conn);
3143             hci_connection_init(conn);
3144 
3145 #ifdef ENABLE_BLE
3146 #ifdef ENABLE_LE_PERIPHERAL
3147             // re-enable advertisements for le connections if active
3148             if (hci_is_le_connection(conn)){
3149                 hci_update_advertisements_enabled_for_current_roles();
3150             }
3151 #endif
3152 #endif
3153             break;
3154 
3155         case HCI_EVENT_HARDWARE_ERROR:
3156             log_error("Hardware Error: 0x%02x", packet[2]);
3157             if (hci_stack->hardware_error_callback){
3158                 (*hci_stack->hardware_error_callback)(packet[2]);
3159             } else {
3160                 // if no special requests, just reboot stack
3161                 hci_power_control_off();
3162                 hci_power_control_on();
3163             }
3164             break;
3165 
3166 #ifdef ENABLE_CLASSIC
3167         case HCI_EVENT_ROLE_CHANGE:
3168             if (packet[2]) break;   // status != 0
3169             reverse_bd_addr(&packet[3], addr);
3170             addr_type = BD_ADDR_TYPE_ACL;
3171             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3172             if (!conn) break;
3173             conn->role = packet[9];
3174             break;
3175 #endif
3176 
3177         case HCI_EVENT_TRANSPORT_PACKET_SENT:
3178             // release packet buffer only for asynchronous transport and if there are not further fragements
3179             if (hci_transport_synchronous()) {
3180                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
3181                 return; // instead of break: to avoid re-entering hci_run()
3182             }
3183             hci_stack->acl_fragmentation_tx_active = 0;
3184             if (hci_stack->acl_fragmentation_total_size) break;
3185             hci_release_packet_buffer();
3186 
3187             // L2CAP receives this event via the hci_emit_event below
3188 
3189 #ifdef ENABLE_CLASSIC
3190             // For SCO, we do the can_send_now_check here
3191             hci_notify_if_sco_can_send_now();
3192 #endif
3193             break;
3194 
3195 #ifdef ENABLE_CLASSIC
3196         case HCI_EVENT_SCO_CAN_SEND_NOW:
3197             // For SCO, we do the can_send_now_check here
3198             hci_stack->sco_can_send_now = true;
3199             hci_notify_if_sco_can_send_now();
3200             return;
3201 
3202         // explode inquriy results for easier consumption
3203         case HCI_EVENT_INQUIRY_RESULT:
3204         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
3205         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
3206             gap_inquiry_explode(packet, size);
3207             break;
3208 #endif
3209 
3210 #ifdef ENABLE_BLE
3211         case HCI_EVENT_LE_META:
3212             switch (packet[2]){
3213 #ifdef ENABLE_LE_CENTRAL
3214                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
3215                     // log_info("advertising report received");
3216                     if (!hci_stack->le_scanning_enabled) break;
3217                     le_handle_advertisement_report(packet, size);
3218                     break;
3219 #endif
3220                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
3221 					event_handle_le_connection_complete(packet);
3222                     break;
3223 
3224                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
3225                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
3226                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
3227                     conn = hci_connection_for_handle(handle);
3228                     if (!conn) break;
3229                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
3230                     break;
3231 
3232                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
3233                     // connection
3234                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
3235                     conn = hci_connection_for_handle(handle);
3236                     if (conn) {
3237                         // read arguments
3238                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
3239                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
3240                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
3241                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
3242 
3243                         // validate against current connection parameter range
3244                         le_connection_parameter_range_t existing_range;
3245                         gap_get_connection_parameter_range(&existing_range);
3246                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
3247                         if (update_parameter){
3248                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
3249                             conn->le_conn_interval_min = le_conn_interval_min;
3250                             conn->le_conn_interval_max = le_conn_interval_max;
3251                             conn->le_conn_latency = le_conn_latency;
3252                             conn->le_supervision_timeout = le_supervision_timeout;
3253                         } else {
3254                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NEGATIVE_REPLY;
3255                         }
3256                     }
3257                     break;
3258 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
3259                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
3260                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
3261                     conn = hci_connection_for_handle(handle);
3262                     if (conn) {
3263                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
3264                     }
3265                     break;
3266 #endif
3267                 default:
3268                     break;
3269             }
3270             break;
3271 #endif
3272         case HCI_EVENT_VENDOR_SPECIFIC:
3273             // Vendor specific commands often create vendor specific event instead of num completed packets
3274             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
3275             switch (hci_stack->manufacturer){
3276                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
3277                     hci_stack->num_cmd_packets = 1;
3278                     break;
3279                 default:
3280                     break;
3281             }
3282             break;
3283         default:
3284             break;
3285     }
3286 
3287     handle_event_for_current_stack_state(packet, size);
3288 
3289     // notify upper stack
3290 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
3291 
3292     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
3293     if ((hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE) && (packet[2] == 0)){
3294 		handle = little_endian_read_16(packet, 3);
3295 		hci_connection_t * aConn = hci_connection_for_handle(handle);
3296 		// discard connection if app did not trigger a reconnect in the event handler
3297 		if (aConn && aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
3298 			hci_shutdown_connection(aConn);
3299 		}
3300     }
3301 
3302 	// execute main loop
3303 	hci_run();
3304 }
3305 
3306 #ifdef ENABLE_CLASSIC
3307 
3308 #ifdef ENABLE_SCO_OVER_HCI
3309 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
3310 static void sco_schedule_tx(hci_connection_t * conn);
3311 
3312 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
3313     log_debug("SCO TX Timeout");
3314     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
3315     hci_connection_t * conn = hci_connection_for_handle(con_handle);
3316     if (!conn) return;
3317 
3318     // trigger send
3319     conn->sco_tx_ready = 1;
3320     // extra packet if CVSD but SCO buffer is too short
3321     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
3322         conn->sco_tx_ready++;
3323     }
3324     hci_notify_if_sco_can_send_now();
3325 }
3326 
3327 
3328 #define SCO_TX_AFTER_RX_MS (6)
3329 
3330 static void sco_schedule_tx(hci_connection_t * conn){
3331 
3332     uint32_t now = btstack_run_loop_get_time_ms();
3333     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
3334     int time_delta_ms = sco_tx_ms - now;
3335 
3336     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
3337 
3338     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
3339     btstack_run_loop_remove_timer(timer);
3340     btstack_run_loop_set_timer(timer, time_delta_ms);
3341     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
3342     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
3343     btstack_run_loop_add_timer(timer);
3344 }
3345 #endif
3346 
3347 static void sco_handler(uint8_t * packet, uint16_t size){
3348     // lookup connection struct
3349     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
3350     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
3351     if (!conn) return;
3352 
3353 #ifdef ENABLE_SCO_OVER_HCI
3354     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
3355     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
3356         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
3357             packet[2] = 0x3c;
3358             memmove(&packet[3], &packet[23], 63);
3359             size = 63;
3360         }
3361     }
3362 
3363     if (hci_have_usb_transport()){
3364         // Nothing to do
3365     } else {
3366         // 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);
3367         if (hci_stack->synchronous_flow_control_enabled == 0){
3368             uint32_t now = btstack_run_loop_get_time_ms();
3369 
3370             if (!conn->sco_rx_valid){
3371                 // ignore first 10 packets
3372                 conn->sco_rx_count++;
3373                 // log_debug("sco rx count %u", conn->sco_rx_count);
3374                 if (conn->sco_rx_count == 10) {
3375                     // use first timestamp as is and pretent it just started
3376                     conn->sco_rx_ms = now;
3377                     conn->sco_rx_valid = 1;
3378                     conn->sco_rx_count = 0;
3379                     sco_schedule_tx(conn);
3380                 }
3381             } else {
3382                 // track expected arrival timme
3383                 conn->sco_rx_count++;
3384                 conn->sco_rx_ms += 7;
3385                 int delta = (int32_t) (now - conn->sco_rx_ms);
3386                 if (delta > 0){
3387                     conn->sco_rx_ms++;
3388                 }
3389                 // log_debug("sco rx %u", conn->sco_rx_ms);
3390                 sco_schedule_tx(conn);
3391             }
3392         }
3393     }
3394 #endif
3395 
3396     // deliver to app
3397     if (hci_stack->sco_packet_handler) {
3398         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
3399     }
3400 
3401 #ifdef HAVE_SCO_TRANSPORT
3402     // We can send one packet for each received packet
3403     conn->sco_tx_ready++;
3404     hci_notify_if_sco_can_send_now();
3405 #endif
3406 
3407 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3408     conn->num_packets_completed++;
3409     hci_stack->host_completed_packets = 1;
3410     hci_run();
3411 #endif
3412 }
3413 #endif
3414 
3415 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
3416     hci_dump_packet(packet_type, 1, packet, size);
3417     switch (packet_type) {
3418         case HCI_EVENT_PACKET:
3419             event_handler(packet, size);
3420             break;
3421         case HCI_ACL_DATA_PACKET:
3422             acl_handler(packet, size);
3423             break;
3424 #ifdef ENABLE_CLASSIC
3425         case HCI_SCO_DATA_PACKET:
3426             sco_handler(packet, size);
3427             break;
3428 #endif
3429         default:
3430             break;
3431     }
3432 }
3433 
3434 /**
3435  * @brief Add event packet handler.
3436  */
3437 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
3438     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3439 }
3440 
3441 /**
3442  * @brief Remove event packet handler.
3443  */
3444 void hci_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){
3445     btstack_linked_list_remove(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3446 }
3447 
3448 /** Register HCI packet handlers */
3449 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
3450     hci_stack->acl_packet_handler = handler;
3451 }
3452 
3453 #ifdef ENABLE_CLASSIC
3454 /**
3455  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
3456  */
3457 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
3458     hci_stack->sco_packet_handler = handler;
3459 }
3460 #endif
3461 
3462 static void hci_state_reset(void){
3463     // no connections yet
3464     hci_stack->connections = NULL;
3465 
3466     // keep discoverable/connectable as this has been requested by the client(s)
3467     // hci_stack->discoverable = 0;
3468     // hci_stack->connectable = 0;
3469     // hci_stack->bondable = 1;
3470     // hci_stack->own_addr_type = 0;
3471 
3472     // buffer is free
3473     hci_stack->hci_packet_buffer_reserved = false;
3474 
3475     // no pending cmds
3476     hci_stack->decline_reason = 0;
3477 
3478     hci_stack->secure_connections_active = false;
3479 
3480 #ifdef ENABLE_CLASSIC
3481     hci_stack->inquiry_lap = GAP_IAC_GENERAL_INQUIRY;
3482     hci_stack->page_timeout = 0x6000;  // ca. 15 sec
3483 
3484     hci_stack->gap_tasks =
3485             GAP_TASK_SET_DEFAULT_LINK_POLICY |
3486             GAP_TASK_SET_CLASS_OF_DEVICE |
3487             GAP_TASK_SET_LOCAL_NAME |
3488             GAP_TASK_SET_EIR_DATA |
3489             GAP_TASK_WRITE_SCAN_ENABLE |
3490             GAP_TASK_WRITE_PAGE_TIMEOUT;
3491 #endif
3492 
3493 #ifdef ENABLE_CLASSIC_PAIRING_OOB
3494     hci_stack->classic_read_local_oob_data = false;
3495     hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
3496 #endif
3497 
3498     // LE
3499 #ifdef ENABLE_BLE
3500     memset(hci_stack->le_random_address, 0, 6);
3501     hci_stack->le_random_address_set = 0;
3502 #endif
3503 #ifdef ENABLE_LE_CENTRAL
3504     hci_stack->le_scanning_active  = false;
3505     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3506     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
3507     hci_stack->le_whitelist_capacity = 0;
3508 #endif
3509 #ifdef ENABLE_LE_PERIPHERAL
3510     hci_stack->le_advertisements_active = false;
3511     if ((hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_PARAMS_SET) != 0){
3512         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3513     }
3514     if (hci_stack->le_advertisements_data != NULL){
3515         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3516     }
3517 #endif
3518 }
3519 
3520 #ifdef ENABLE_CLASSIC
3521 /**
3522  * @brief Configure Bluetooth hardware control. Has to be called before power on.
3523  */
3524 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
3525     // store and open remote device db
3526     hci_stack->link_key_db = link_key_db;
3527     if (hci_stack->link_key_db) {
3528         hci_stack->link_key_db->open();
3529     }
3530 }
3531 #endif
3532 
3533 void hci_init(const hci_transport_t *transport, const void *config){
3534 
3535 #ifdef HAVE_MALLOC
3536     if (!hci_stack) {
3537         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
3538     }
3539 #else
3540     hci_stack = &hci_stack_static;
3541 #endif
3542     memset(hci_stack, 0, sizeof(hci_stack_t));
3543 
3544     // reference to use transport layer implementation
3545     hci_stack->hci_transport = transport;
3546 
3547     // reference to used config
3548     hci_stack->config = config;
3549 
3550     // setup pointer for outgoing packet buffer
3551     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3552 
3553     // max acl payload size defined in config.h
3554     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3555 
3556     // register packet handlers with transport
3557     transport->register_packet_handler(&packet_handler);
3558 
3559     hci_stack->state = HCI_STATE_OFF;
3560 
3561     // class of device
3562     hci_stack->class_of_device = 0x007a020c; // Smartphone
3563 
3564     // bondable by default
3565     hci_stack->bondable = 1;
3566 
3567 #ifdef ENABLE_CLASSIC
3568     // classic name
3569     hci_stack->local_name = default_classic_name;
3570 
3571     // Master slave policy
3572     hci_stack->master_slave_policy = 1;
3573 
3574     // Allow Role Switch
3575     hci_stack->allow_role_switch = 1;
3576 
3577     // Default / minimum security level = 2
3578     hci_stack->gap_security_level = LEVEL_2;
3579 
3580     // Default Security Mode 4
3581     hci_stack->gap_security_mode = GAP_SECURITY_MODE_4;
3582 
3583     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3584     hci_stack->gap_required_encyrption_key_size = 7;
3585 
3586     // Link Supervision Timeout
3587     hci_stack->link_supervision_timeout = HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT;
3588 
3589 #endif
3590 
3591     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3592     hci_stack->ssp_enable = 1;
3593     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3594     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3595     hci_stack->ssp_auto_accept = 1;
3596 
3597     // Secure Connections: enable (requires support from Controller)
3598     hci_stack->secure_connections_enable = true;
3599 
3600     // voice setting - signed 16 bit pcm data with CVSD over the air
3601     hci_stack->sco_voice_setting = 0x60;
3602 
3603 #ifdef ENABLE_LE_CENTRAL
3604     // connection parameter to use for outgoing connections
3605     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3606     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3607     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3608     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3609     hci_stack->le_connection_latency      = 4;         // 4
3610     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3611     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3612     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3613 
3614     // default LE Scanning
3615     hci_stack->le_scan_type     =   0x1; // active
3616     hci_stack->le_scan_interval = 0x1e0; // 300 ms
3617     hci_stack->le_scan_window   =  0x30; //  30 ms
3618 #endif
3619 
3620 #ifdef ENABLE_LE_PERIPHERAL
3621     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3622 #endif
3623 
3624     // connection parameter range used to answer connection parameter update requests in l2cap
3625     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3626     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3627     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3628     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3629     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3630     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3631 
3632     hci_state_reset();
3633 }
3634 
3635 void hci_deinit(void){
3636 #ifdef HAVE_MALLOC
3637     if (hci_stack) {
3638         free(hci_stack);
3639     }
3640 #endif
3641     hci_stack = NULL;
3642 
3643 #ifdef ENABLE_CLASSIC
3644     disable_l2cap_timeouts = 0;
3645 #endif
3646 }
3647 
3648 /**
3649  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3650  */
3651 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3652     hci_stack->chipset = chipset_driver;
3653 
3654     // reset chipset driver - init is also called on power_up
3655     if (hci_stack->chipset && hci_stack->chipset->init){
3656         hci_stack->chipset->init(hci_stack->config);
3657     }
3658 }
3659 
3660 /**
3661  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3662  */
3663 void hci_set_control(const btstack_control_t *hardware_control){
3664     // references to used control implementation
3665     hci_stack->control = hardware_control;
3666     // init with transport config
3667     hardware_control->init(hci_stack->config);
3668 }
3669 
3670 static void hci_discard_connections(void){
3671     btstack_linked_list_iterator_t lit;
3672     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3673     while (btstack_linked_list_iterator_has_next(&lit)){
3674         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3675         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3676         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3677         hci_shutdown_connection(connection);
3678     }
3679 }
3680 
3681 void hci_close(void){
3682 
3683 #ifdef ENABLE_CLASSIC
3684     // close remote device db
3685     if (hci_stack->link_key_db) {
3686         hci_stack->link_key_db->close();
3687     }
3688 #endif
3689 
3690     hci_discard_connections();
3691 
3692     hci_power_control(HCI_POWER_OFF);
3693 
3694 #ifdef HAVE_MALLOC
3695     free(hci_stack);
3696 #endif
3697     hci_stack = NULL;
3698 }
3699 
3700 #ifdef HAVE_SCO_TRANSPORT
3701 void hci_set_sco_transport(const btstack_sco_transport_t *sco_transport){
3702     hci_stack->sco_transport = sco_transport;
3703     sco_transport->register_packet_handler(&packet_handler);
3704 }
3705 #endif
3706 
3707 #ifdef ENABLE_CLASSIC
3708 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3709     // validate ranage and set
3710     if (encryption_key_size < 7)  return;
3711     if (encryption_key_size > 16) return;
3712     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3713 }
3714 
3715 uint8_t gap_set_security_mode(gap_security_mode_t security_mode){
3716     if ((security_mode == GAP_SECURITY_MODE_4) || (security_mode == GAP_SECURITY_MODE_2)){
3717         hci_stack->gap_security_mode = security_mode;
3718         return ERROR_CODE_SUCCESS;
3719     } else {
3720         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3721     }
3722 }
3723 
3724 gap_security_mode_t gap_get_security_mode(void){
3725     return hci_stack->gap_security_mode;
3726 }
3727 
3728 void gap_set_security_level(gap_security_level_t security_level){
3729     hci_stack->gap_security_level = security_level;
3730 }
3731 
3732 gap_security_level_t gap_get_security_level(void){
3733     if (hci_stack->gap_secure_connections_only_mode){
3734         return LEVEL_4;
3735     }
3736     return hci_stack->gap_security_level;
3737 }
3738 
3739 void gap_set_minimal_service_security_level(gap_security_level_t security_level){
3740     hci_stack->gap_minimal_service_security_level = security_level;
3741 }
3742 
3743 void gap_set_secure_connections_only_mode(bool enable){
3744     hci_stack->gap_secure_connections_only_mode = enable;
3745 }
3746 
3747 bool gap_get_secure_connections_only_mode(void){
3748     return hci_stack->gap_secure_connections_only_mode;
3749 }
3750 #endif
3751 
3752 #ifdef ENABLE_CLASSIC
3753 void gap_set_class_of_device(uint32_t class_of_device){
3754     hci_stack->class_of_device = class_of_device;
3755     hci_stack->gap_tasks |= GAP_TASK_SET_CLASS_OF_DEVICE;
3756     hci_run();
3757 }
3758 
3759 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3760     hci_stack->default_link_policy_settings = default_link_policy_settings;
3761     hci_stack->gap_tasks |= GAP_TASK_SET_DEFAULT_LINK_POLICY;
3762     hci_run();
3763 }
3764 
3765 void gap_set_allow_role_switch(bool allow_role_switch){
3766     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3767 }
3768 
3769 uint8_t hci_get_allow_role_switch(void){
3770     return  hci_stack->allow_role_switch;
3771 }
3772 
3773 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3774     hci_stack->link_supervision_timeout = link_supervision_timeout;
3775 }
3776 
3777 void hci_disable_l2cap_timeout_check(void){
3778     disable_l2cap_timeouts = 1;
3779 }
3780 #endif
3781 
3782 #ifndef HAVE_HOST_CONTROLLER_API
3783 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3784 void hci_set_bd_addr(bd_addr_t addr){
3785     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3786     hci_stack->custom_bd_addr_set = 1;
3787 }
3788 #endif
3789 
3790 // State-Module-Driver overview
3791 // state                    module  low-level
3792 // HCI_STATE_OFF             off      close
3793 // HCI_STATE_INITIALIZING,   on       open
3794 // HCI_STATE_WORKING,        on       open
3795 // HCI_STATE_HALTING,        on       open
3796 // HCI_STATE_SLEEPING,    off/sleep   close
3797 // HCI_STATE_FALLING_ASLEEP  on       open
3798 
3799 static int hci_power_control_on(void){
3800 
3801     // power on
3802     int err = 0;
3803     if (hci_stack->control && hci_stack->control->on){
3804         err = (*hci_stack->control->on)();
3805     }
3806     if (err){
3807         log_error( "POWER_ON failed");
3808         hci_emit_hci_open_failed();
3809         return err;
3810     }
3811 
3812     // int chipset driver
3813     if (hci_stack->chipset && hci_stack->chipset->init){
3814         hci_stack->chipset->init(hci_stack->config);
3815     }
3816 
3817     // init transport
3818     if (hci_stack->hci_transport->init){
3819         hci_stack->hci_transport->init(hci_stack->config);
3820     }
3821 
3822     // open transport
3823     err = hci_stack->hci_transport->open();
3824     if (err){
3825         log_error( "HCI_INIT failed, turning Bluetooth off again");
3826         if (hci_stack->control && hci_stack->control->off){
3827             (*hci_stack->control->off)();
3828         }
3829         hci_emit_hci_open_failed();
3830         return err;
3831     }
3832     return 0;
3833 }
3834 
3835 static void hci_power_control_off(void){
3836 
3837     log_info("hci_power_control_off");
3838 
3839     // close low-level device
3840     hci_stack->hci_transport->close();
3841 
3842     log_info("hci_power_control_off - hci_transport closed");
3843 
3844     // power off
3845     if (hci_stack->control && hci_stack->control->off){
3846         (*hci_stack->control->off)();
3847     }
3848 
3849     log_info("hci_power_control_off - control closed");
3850 
3851     hci_stack->state = HCI_STATE_OFF;
3852 }
3853 
3854 static void hci_power_control_sleep(void){
3855 
3856     log_info("hci_power_control_sleep");
3857 
3858 #if 0
3859     // don't close serial port during sleep
3860 
3861     // close low-level device
3862     hci_stack->hci_transport->close(hci_stack->config);
3863 #endif
3864 
3865     // sleep mode
3866     if (hci_stack->control && hci_stack->control->sleep){
3867         (*hci_stack->control->sleep)();
3868     }
3869 
3870     hci_stack->state = HCI_STATE_SLEEPING;
3871 }
3872 
3873 static int hci_power_control_wake(void){
3874 
3875     log_info("hci_power_control_wake");
3876 
3877     // wake on
3878     if (hci_stack->control && hci_stack->control->wake){
3879         (*hci_stack->control->wake)();
3880     }
3881 
3882 #if 0
3883     // open low-level device
3884     int err = hci_stack->hci_transport->open(hci_stack->config);
3885     if (err){
3886         log_error( "HCI_INIT failed, turning Bluetooth off again");
3887         if (hci_stack->control && hci_stack->control->off){
3888             (*hci_stack->control->off)();
3889         }
3890         hci_emit_hci_open_failed();
3891         return err;
3892     }
3893 #endif
3894 
3895     return 0;
3896 }
3897 
3898 static void hci_power_transition_to_initializing(void){
3899     // set up state machine
3900     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3901     hci_stack->hci_packet_buffer_reserved = false;
3902     hci_stack->state = HCI_STATE_INITIALIZING;
3903     hci_stack->substate = HCI_INIT_SEND_RESET;
3904 }
3905 
3906 // returns error
3907 static int hci_power_control_state_off(HCI_POWER_MODE power_mode){
3908     int err;
3909     switch (power_mode){
3910         case HCI_POWER_ON:
3911             err = hci_power_control_on();
3912             if (err != 0) {
3913                 log_error("hci_power_control_on() error %d", err);
3914                 return err;
3915             }
3916             hci_power_transition_to_initializing();
3917             break;
3918         case HCI_POWER_OFF:
3919             // do nothing
3920             break;
3921         case HCI_POWER_SLEEP:
3922             // do nothing (with SLEEP == OFF)
3923             break;
3924         default:
3925             btstack_assert(false);
3926             break;
3927     }
3928     return ERROR_CODE_SUCCESS;
3929 }
3930 
3931 static int hci_power_control_state_initializing(HCI_POWER_MODE power_mode){
3932     switch (power_mode){
3933         case HCI_POWER_ON:
3934             // do nothing
3935             break;
3936         case HCI_POWER_OFF:
3937             // no connections yet, just turn it off
3938             hci_power_control_off();
3939             break;
3940         case HCI_POWER_SLEEP:
3941             // no connections yet, just turn it off
3942             hci_power_control_sleep();
3943             break;
3944         default:
3945             btstack_assert(false);
3946             break;
3947     }
3948     return ERROR_CODE_SUCCESS;
3949 }
3950 
3951 static int hci_power_control_state_working(HCI_POWER_MODE power_mode) {
3952     switch (power_mode){
3953         case HCI_POWER_ON:
3954             // do nothing
3955             break;
3956         case HCI_POWER_OFF:
3957             // see hci_run
3958             hci_stack->state = HCI_STATE_HALTING;
3959             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3960             // setup watchdog timer for disconnect - only triggers if Controller does not respond anymore
3961             btstack_run_loop_set_timer(&hci_stack->timeout, 1000);
3962             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
3963             btstack_run_loop_add_timer(&hci_stack->timeout);
3964             break;
3965         case HCI_POWER_SLEEP:
3966             // see hci_run
3967             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3968             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3969             break;
3970         default:
3971             btstack_assert(false);
3972             break;
3973     }
3974     return ERROR_CODE_SUCCESS;
3975 }
3976 
3977 static int hci_power_control_state_halting(HCI_POWER_MODE power_mode) {
3978     switch (power_mode){
3979         case HCI_POWER_ON:
3980             hci_power_transition_to_initializing();
3981             break;
3982         case HCI_POWER_OFF:
3983             // do nothing
3984             break;
3985         case HCI_POWER_SLEEP:
3986             // see hci_run
3987             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3988             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3989             break;
3990         default:
3991             btstack_assert(false);
3992             break;
3993     }
3994     return ERROR_CODE_SUCCESS;
3995 }
3996 
3997 static int hci_power_control_state_falling_asleep(HCI_POWER_MODE power_mode) {
3998     switch (power_mode){
3999         case HCI_POWER_ON:
4000             hci_power_transition_to_initializing();
4001             break;
4002         case HCI_POWER_OFF:
4003             // see hci_run
4004             hci_stack->state = HCI_STATE_HALTING;
4005             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
4006             break;
4007         case HCI_POWER_SLEEP:
4008             // do nothing
4009             break;
4010         default:
4011             btstack_assert(false);
4012             break;
4013     }
4014     return ERROR_CODE_SUCCESS;
4015 }
4016 
4017 static int hci_power_control_state_sleeping(HCI_POWER_MODE power_mode) {
4018     int err;
4019     switch (power_mode){
4020         case HCI_POWER_ON:
4021             err = hci_power_control_wake();
4022             if (err) return err;
4023             hci_power_transition_to_initializing();
4024             break;
4025         case HCI_POWER_OFF:
4026             hci_stack->state = HCI_STATE_HALTING;
4027             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
4028             break;
4029         case HCI_POWER_SLEEP:
4030             // do nothing
4031             break;
4032         default:
4033             btstack_assert(false);
4034             break;
4035     }
4036     return ERROR_CODE_SUCCESS;
4037 }
4038 
4039 int hci_power_control(HCI_POWER_MODE power_mode){
4040     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
4041     int err = 0;
4042     switch (hci_stack->state){
4043         case HCI_STATE_OFF:
4044             err = hci_power_control_state_off(power_mode);
4045             break;
4046         case HCI_STATE_INITIALIZING:
4047             err = hci_power_control_state_initializing(power_mode);
4048             break;
4049         case HCI_STATE_WORKING:
4050             err = hci_power_control_state_working(power_mode);
4051             break;
4052         case HCI_STATE_HALTING:
4053             err = hci_power_control_state_halting(power_mode);
4054             break;
4055         case HCI_STATE_FALLING_ASLEEP:
4056             err = hci_power_control_state_falling_asleep(power_mode);
4057             break;
4058         case HCI_STATE_SLEEPING:
4059             err = hci_power_control_state_sleeping(power_mode);
4060             break;
4061         default:
4062             btstack_assert(false);
4063             break;
4064     }
4065     if (err != 0){
4066         return err;
4067     }
4068 
4069     // create internal event
4070 	hci_emit_state();
4071 
4072 	// trigger next/first action
4073 	hci_run();
4074 
4075     return 0;
4076 }
4077 
4078 
4079 static void hci_halting_run(void){
4080 
4081     log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4082 
4083     hci_connection_t * connection;
4084 
4085     switch (hci_stack->substate) {
4086         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4087             case HCI_HALTING_DISCONNECT_ALL_TIMER:
4088 
4089 #ifdef ENABLE_BLE
4090 #ifdef ENABLE_LE_CENTRAL
4091     hci_whitelist_free();
4092 #endif
4093 #endif
4094     // close all open connections
4095     connection = (hci_connection_t *) hci_stack->connections;
4096     if (connection) {
4097         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
4098         if (!hci_can_send_command_packet_now()) return;
4099 
4100         // check state
4101         if (connection->state == SENT_DISCONNECT) return;
4102         connection->state = SENT_DISCONNECT;
4103 
4104         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
4105 
4106         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
4107         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
4108 
4109         // ... which would be ignored anyway as we shutdown (free) the connection now
4110         hci_shutdown_connection(connection);
4111 
4112         // finally, send the disconnect command
4113         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4114         return;
4115     }
4116 
4117     btstack_run_loop_remove_timer(&hci_stack->timeout);
4118 
4119     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER) {
4120         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
4121         log_info("HCI_STATE_HALTING: wait 50 ms");
4122         hci_stack->substate = HCI_HALTING_W4_TIMER;
4123         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
4124         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
4125         btstack_run_loop_add_timer(&hci_stack->timeout);
4126         break;
4127     }
4128 
4129     /* fall through */
4130 
4131     case HCI_HALTING_CLOSE:
4132         // close left over connections (that had not been properly closed before)
4133         hci_discard_connections();
4134 
4135         log_info("HCI_STATE_HALTING, calling off");
4136 
4137         // switch mode
4138         hci_power_control_off();
4139 
4140         log_info("HCI_STATE_HALTING, emitting state");
4141         hci_emit_state();
4142         log_info("HCI_STATE_HALTING, done");
4143         break;
4144 
4145         case HCI_HALTING_W4_TIMER:
4146             // keep waiting
4147 
4148             break;
4149         default:
4150             break;
4151     }
4152 };
4153 
4154 static void hci_falling_asleep_run(void){
4155     hci_connection_t * connection;
4156     switch(hci_stack->substate) {
4157         case HCI_FALLING_ASLEEP_DISCONNECT:
4158             log_info("HCI_STATE_FALLING_ASLEEP");
4159             // close all open connections
4160             connection =  (hci_connection_t *) hci_stack->connections;
4161             if (connection){
4162 
4163                 // send disconnect
4164                 if (!hci_can_send_command_packet_now()) return;
4165 
4166                 log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
4167                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4168 
4169                 // send disconnected event right away - causes higher layer connections to get closed, too.
4170                 hci_shutdown_connection(connection);
4171                 return;
4172             }
4173 
4174             if (hci_classic_supported()){
4175                 // disable page and inquiry scan
4176                 if (!hci_can_send_command_packet_now()) return;
4177 
4178                 log_info("HCI_STATE_HALTING, disabling inq scans");
4179                 hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
4180 
4181                 // continue in next sub state
4182                 hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
4183                 break;
4184             }
4185 
4186             /* fall through */
4187 
4188             case HCI_FALLING_ASLEEP_COMPLETE:
4189                 log_info("HCI_STATE_HALTING, calling sleep");
4190                 // switch mode
4191                 hci_power_control_sleep();  // changes hci_stack->state to SLEEP
4192                 hci_emit_state();
4193                 break;
4194 
4195                 default:
4196                     break;
4197     }
4198 }
4199 
4200 #ifdef ENABLE_CLASSIC
4201 
4202 static void hci_update_scan_enable(void){
4203     // 2 = page scan, 1 = inq scan
4204     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
4205     hci_stack->gap_tasks |= GAP_TASK_WRITE_SCAN_ENABLE;
4206     hci_run();
4207 }
4208 
4209 void gap_discoverable_control(uint8_t enable){
4210     if (enable) enable = 1; // normalize argument
4211 
4212     if (hci_stack->discoverable == enable){
4213         hci_emit_discoverable_enabled(hci_stack->discoverable);
4214         return;
4215     }
4216 
4217     hci_stack->discoverable = enable;
4218     hci_update_scan_enable();
4219 }
4220 
4221 void gap_connectable_control(uint8_t enable){
4222     if (enable) enable = 1; // normalize argument
4223 
4224     // don't emit event
4225     if (hci_stack->connectable == enable) return;
4226 
4227     hci_stack->connectable = enable;
4228     hci_update_scan_enable();
4229 }
4230 #endif
4231 
4232 void gap_local_bd_addr(bd_addr_t address_buffer){
4233     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
4234 }
4235 
4236 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4237 static void hci_host_num_completed_packets(void){
4238 
4239     // create packet manually as arrays are not supported and num_commands should not get reduced
4240     hci_reserve_packet_buffer();
4241     uint8_t * packet = hci_get_outgoing_packet_buffer();
4242 
4243     uint16_t size = 0;
4244     uint16_t num_handles = 0;
4245     packet[size++] = 0x35;
4246     packet[size++] = 0x0c;
4247     size++;  // skip param len
4248     size++;  // skip num handles
4249 
4250     // add { handle, packets } entries
4251     btstack_linked_item_t * it;
4252     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
4253         hci_connection_t * connection = (hci_connection_t *) it;
4254         if (connection->num_packets_completed){
4255             little_endian_store_16(packet, size, connection->con_handle);
4256             size += 2;
4257             little_endian_store_16(packet, size, connection->num_packets_completed);
4258             size += 2;
4259             //
4260             num_handles++;
4261             connection->num_packets_completed = 0;
4262         }
4263     }
4264 
4265     packet[2] = size - 3;
4266     packet[3] = num_handles;
4267 
4268     hci_stack->host_completed_packets = 0;
4269 
4270     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4271     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4272 
4273     // release packet buffer for synchronous transport implementations
4274     if (hci_transport_synchronous()){
4275         hci_release_packet_buffer();
4276         hci_emit_transport_packet_sent();
4277     }
4278 }
4279 #endif
4280 
4281 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
4282     UNUSED(ds);
4283     hci_stack->substate = HCI_HALTING_CLOSE;
4284     // allow packet handlers to defer final shutdown
4285     hci_emit_state();
4286     hci_run();
4287 }
4288 
4289 static bool hci_run_acl_fragments(void){
4290     if (hci_stack->acl_fragmentation_total_size > 0u) {
4291         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
4292         hci_connection_t *connection = hci_connection_for_handle(con_handle);
4293         if (connection) {
4294             if (hci_can_send_prepared_acl_packet_now(con_handle)){
4295                 hci_send_acl_packet_fragments(connection);
4296                 return true;
4297             }
4298         } else {
4299             // connection gone -> discard further fragments
4300             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
4301             hci_stack->acl_fragmentation_total_size = 0;
4302             hci_stack->acl_fragmentation_pos = 0;
4303         }
4304     }
4305     return false;
4306 }
4307 
4308 #ifdef ENABLE_CLASSIC
4309 static bool hci_run_general_gap_classic(void){
4310 
4311     // assert stack is working and classic is active
4312     if (hci_classic_supported() == false)      return false;
4313     if (hci_stack->state != HCI_STATE_WORKING) return false;
4314 
4315     // decline incoming connections
4316     if (hci_stack->decline_reason){
4317         uint8_t reason = hci_stack->decline_reason;
4318         hci_stack->decline_reason = 0;
4319         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
4320         return true;
4321     }
4322 
4323     if (hci_stack->gap_tasks != 0){
4324         hci_run_gap_tasks_classic();
4325         return true;
4326     }
4327 
4328     // start/stop inquiry
4329     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
4330         uint8_t duration = hci_stack->inquiry_state;
4331         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_ACTIVE;
4332         hci_send_cmd(&hci_inquiry, hci_stack->inquiry_lap, duration, 0);
4333         return true;
4334     }
4335     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
4336         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
4337         hci_send_cmd(&hci_inquiry_cancel);
4338         return true;
4339     }
4340     // remote name request
4341     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
4342         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
4343         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
4344                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
4345         return true;
4346     }
4347 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4348     // Local OOB data
4349     if (hci_stack->classic_read_local_oob_data){
4350         hci_stack->classic_read_local_oob_data = false;
4351         if (hci_stack->local_supported_commands[1] & 0x10u){
4352             hci_send_cmd(&hci_read_local_extended_oob_data);
4353         } else {
4354             hci_send_cmd(&hci_read_local_oob_data);
4355         }
4356     }
4357 #endif
4358     // pairing
4359     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
4360         uint8_t state = hci_stack->gap_pairing_state;
4361         uint8_t pin_code[16];
4362         switch (state){
4363             case GAP_PAIRING_STATE_SEND_PIN:
4364                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4365                 memset(pin_code, 0, 16);
4366                 memcpy(pin_code, hci_stack->gap_pairing_input.gap_pairing_pin, hci_stack->gap_pairing_pin_len);
4367                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_pin_len, pin_code);
4368                 break;
4369             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
4370                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4371                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
4372                 break;
4373             case GAP_PAIRING_STATE_SEND_PASSKEY:
4374                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4375                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
4376                 break;
4377             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
4378                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4379                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
4380                 break;
4381             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
4382                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4383                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
4384                 break;
4385             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
4386                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4387                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
4388                 break;
4389             default:
4390                 break;
4391         }
4392         return true;
4393     }
4394     return false;
4395 }
4396 #endif
4397 
4398 #ifdef ENABLE_BLE
4399 static bool hci_run_general_gap_le(void){
4400 
4401     // advertisements, active scanning, and creating connections requires random address to be set if using private address
4402 
4403     if (hci_stack->state != HCI_STATE_WORKING) return false;
4404     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
4405 
4406 
4407     // Phase 1: collect what to stop
4408 
4409     bool scanning_stop = false;
4410     bool connecting_stop = false;
4411     bool advertising_stop = false;
4412 
4413 #ifndef ENABLE_LE_CENTRAL
4414     UNUSED(scanning_stop);
4415     UNUSED(connecting_stop);
4416 #endif
4417 #ifndef ENABLE_LE_PERIPHERAL
4418     UNUSED(advertising_stop);
4419 #endif
4420 
4421     // check if own address changes
4422     bool random_address_change = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADDRESS) != 0;
4423 
4424     // check if whitelist needs modification
4425     bool whitelist_modification_pending = false;
4426     btstack_linked_list_iterator_t lit;
4427     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4428     while (btstack_linked_list_iterator_has_next(&lit)){
4429         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4430         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
4431             whitelist_modification_pending = true;
4432             break;
4433         }
4434     }
4435     // check if resolving list needs modification
4436     bool resolving_list_modification_pending = false;
4437 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4438     bool resolving_list_supported = (hci_stack->local_supported_commands[1] & (1 << 2)) != 0;
4439 	if (resolving_list_supported && hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_DONE){
4440         resolving_list_modification_pending = true;
4441     }
4442 #endif
4443 
4444 #ifdef ENABLE_LE_CENTRAL
4445     // scanning control
4446     if (hci_stack->le_scanning_active) {
4447         // stop if:
4448         // - parameter change required
4449         // - it's disabled
4450         // - whitelist change required but used for scanning
4451         // - resolving list modified
4452         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
4453         if ((hci_stack->le_scanning_param_update) ||
4454             !hci_stack->le_scanning_enabled ||
4455             scanning_uses_whitelist ||
4456             resolving_list_modification_pending){
4457 
4458             scanning_stop = true;
4459         }
4460     }
4461 #endif
4462 
4463 #ifdef ENABLE_LE_CENTRAL
4464     // connecting control
4465     bool connecting_with_whitelist;
4466     switch (hci_stack->le_connecting_state){
4467         case LE_CONNECTING_DIRECT:
4468         case LE_CONNECTING_WHITELIST:
4469             // stop connecting if:
4470             // - connecting uses white and whitelist modification pending
4471             // - if it got disabled
4472             // - resolving list modified
4473             connecting_with_whitelist = hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST;
4474             if ((connecting_with_whitelist && whitelist_modification_pending) ||
4475                 (hci_stack->le_connecting_request == LE_CONNECTING_IDLE) ||
4476                 resolving_list_modification_pending) {
4477 
4478                 connecting_stop = true;
4479             }
4480             break;
4481         default:
4482             break;
4483     }
4484 #endif
4485 
4486 #ifdef ENABLE_LE_PERIPHERAL
4487     // le advertisement control
4488     if (hci_stack->le_advertisements_active){
4489         // stop if:
4490         // - parameter change required
4491         // - random address used in advertising and changes
4492         // - it's disabled
4493         // - whitelist change required but used for advertisement filter policy
4494         // - resolving list modified
4495         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy != 0;
4496         bool advertising_uses_random_address = hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC;
4497         bool advertising_change    = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS)  != 0;
4498         if (advertising_change ||
4499             (advertising_uses_random_address && random_address_change) ||
4500             (hci_stack->le_advertisements_enabled_for_current_roles == 0) ||
4501             (advertising_uses_whitelist && whitelist_modification_pending) ||
4502             resolving_list_modification_pending) {
4503 
4504             advertising_stop = true;
4505         }
4506     }
4507 #endif
4508 
4509 
4510     // Phase 2: stop everything that should be off during modifications
4511 
4512 #ifdef ENABLE_LE_CENTRAL
4513     if (scanning_stop){
4514         hci_stack->le_scanning_active = false;
4515         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
4516         return true;
4517     }
4518 #endif
4519 
4520 #ifdef ENABLE_LE_CENTRAL
4521     if (connecting_stop){
4522         hci_send_cmd(&hci_le_create_connection_cancel);
4523         return true;
4524     }
4525 #endif
4526 
4527 #ifdef ENABLE_LE_PERIPHERAL
4528     if (advertising_stop){
4529         hci_stack->le_advertisements_active = false;
4530         hci_send_cmd(&hci_le_set_advertise_enable, 0);
4531         return true;
4532     }
4533 #endif
4534 
4535     // Phase 3: modify
4536 
4537     if (random_address_change){
4538         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADDRESS;
4539         hci_send_cmd(&hci_le_set_random_address, hci_stack->le_random_address);
4540         return true;
4541     }
4542 
4543 #ifdef ENABLE_LE_CENTRAL
4544     if (hci_stack->le_scanning_param_update){
4545         hci_stack->le_scanning_param_update = false;
4546         hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
4547                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
4548         return true;
4549     }
4550 #endif
4551 
4552 #ifdef ENABLE_LE_PERIPHERAL
4553     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
4554         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
4555         hci_stack->le_advertisements_own_addr_type = hci_stack->le_own_addr_type;
4556         hci_send_cmd(&hci_le_set_advertising_parameters,
4557                      hci_stack->le_advertisements_interval_min,
4558                      hci_stack->le_advertisements_interval_max,
4559                      hci_stack->le_advertisements_type,
4560                      hci_stack->le_advertisements_own_addr_type,
4561                      hci_stack->le_advertisements_direct_address_type,
4562                      hci_stack->le_advertisements_direct_address,
4563                      hci_stack->le_advertisements_channel_map,
4564                      hci_stack->le_advertisements_filter_policy);
4565         return true;
4566     }
4567     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
4568         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
4569         uint8_t adv_data_clean[31];
4570         memset(adv_data_clean, 0, sizeof(adv_data_clean));
4571         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
4572                      hci_stack->le_advertisements_data_len);
4573         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
4574         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
4575         return true;
4576     }
4577     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
4578         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
4579         uint8_t scan_data_clean[31];
4580         memset(scan_data_clean, 0, sizeof(scan_data_clean));
4581         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
4582                      hci_stack->le_scan_response_data_len);
4583         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
4584         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
4585         return true;
4586     }
4587 #endif
4588 
4589 
4590 #ifdef ENABLE_LE_CENTRAL
4591     // if connect with whitelist was active and is not cancelled yet, wait until next time
4592     if (hci_stack->le_connecting_state == LE_CONNECTING_CANCEL) return false;
4593 #endif
4594 
4595     // LE Whitelist Management
4596     if (whitelist_modification_pending){
4597         // add/remove entries
4598         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4599         while (btstack_linked_list_iterator_has_next(&lit)){
4600             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4601 			if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
4602 				entry->state &= ~LE_WHITELIST_REMOVE_FROM_CONTROLLER;
4603 				hci_send_cmd(&hci_le_remove_device_from_white_list, entry->address_type, entry->address);
4604 				return true;
4605 			}
4606             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
4607 				entry->state &= ~LE_WHITELIST_ADD_TO_CONTROLLER;
4608                 entry->state |= LE_WHITELIST_ON_CONTROLLER;
4609                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
4610                 return true;
4611             }
4612             if ((entry->state & LE_WHITELIST_ON_CONTROLLER) == 0){
4613 				btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4614 				btstack_memory_whitelist_entry_free(entry);
4615             }
4616         }
4617     }
4618 
4619 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4620     // LE Resolving List Management
4621     if (resolving_list_supported) {
4622 		uint16_t i;
4623 		switch (hci_stack->le_resolving_list_state) {
4624 			case LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION:
4625 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
4626 				hci_send_cmd(&hci_le_set_address_resolution_enabled, 1);
4627 				return true;
4628 			case LE_RESOLVING_LIST_READ_SIZE:
4629 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_SEND_CLEAR;
4630 				hci_send_cmd(&hci_le_read_resolving_list_size);
4631 				return true;
4632 			case LE_RESOLVING_LIST_SEND_CLEAR:
4633 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
4634 				(void) memset(hci_stack->le_resolving_list_add_entries, 0xff,
4635 							  sizeof(hci_stack->le_resolving_list_add_entries));
4636 				(void) memset(hci_stack->le_resolving_list_remove_entries, 0,
4637 							  sizeof(hci_stack->le_resolving_list_remove_entries));
4638 				hci_send_cmd(&hci_le_clear_resolving_list);
4639 				return true;
4640 			case LE_RESOLVING_LIST_REMOVE_ENTRIES:
4641 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4642 					uint8_t offset = i >> 3;
4643 					uint8_t mask = 1 << (i & 7);
4644 					if ((hci_stack->le_resolving_list_remove_entries[offset] & mask) == 0) continue;
4645 					hci_stack->le_resolving_list_remove_entries[offset] &= ~mask;
4646 					bd_addr_t peer_identity_addreses;
4647 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4648 					sm_key_t peer_irk;
4649 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4650 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4651 
4652 #ifdef ENABLE_LE_WHITELIST_TOUCH_AFTER_RESOLVING_LIST_UPDATE
4653 					// trigger whitelist entry 'update' (work around for controller bug)
4654 					btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4655 					while (btstack_linked_list_iterator_has_next(&lit)) {
4656 						whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&lit);
4657 						if (entry->address_type != peer_identity_addr_type) continue;
4658 						if (memcmp(entry->address, peer_identity_addreses, 6) != 0) continue;
4659 						log_info("trigger whitelist update %s", bd_addr_to_str(peer_identity_addreses));
4660 						entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER;
4661 					}
4662 #endif
4663 
4664 					hci_send_cmd(&hci_le_remove_device_from_resolving_list, peer_identity_addr_type,
4665 								 peer_identity_addreses);
4666 					return true;
4667 				}
4668 
4669 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_ADD_ENTRIES;
4670 
4671 				/* fall through */
4672 
4673 			case LE_RESOLVING_LIST_ADD_ENTRIES:
4674 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4675 					uint8_t offset = i >> 3;
4676 					uint8_t mask = 1 << (i & 7);
4677 					if ((hci_stack->le_resolving_list_add_entries[offset] & mask) == 0) continue;
4678 					hci_stack->le_resolving_list_add_entries[offset] &= ~mask;
4679 					bd_addr_t peer_identity_addreses;
4680 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4681 					sm_key_t peer_irk;
4682 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4683 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4684 					const uint8_t *local_irk = gap_get_persistent_irk();
4685 					// command uses format specifier 'P' that stores 16-byte value without flip
4686 					uint8_t local_irk_flipped[16];
4687 					uint8_t peer_irk_flipped[16];
4688 					reverse_128(local_irk, local_irk_flipped);
4689 					reverse_128(peer_irk, peer_irk_flipped);
4690 					hci_send_cmd(&hci_le_add_device_to_resolving_list, peer_identity_addr_type, peer_identity_addreses,
4691 								 peer_irk_flipped, local_irk_flipped);
4692 					return true;
4693 				}
4694 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4695 				break;
4696 
4697 			default:
4698 				break;
4699 		}
4700 	}
4701     hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4702 #endif
4703 
4704     // Phase 4: restore state
4705 
4706 #ifdef ENABLE_LE_CENTRAL
4707     // re-start scanning
4708     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
4709         hci_stack->le_scanning_active = true;
4710         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
4711         return true;
4712     }
4713 #endif
4714 
4715 #ifdef ENABLE_LE_CENTRAL
4716     // re-start connecting
4717     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
4718         bd_addr_t null_addr;
4719         memset(null_addr, 0, 6);
4720         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4721         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4722         hci_send_cmd(&hci_le_create_connection,
4723                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
4724                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
4725                      1,         // use whitelist
4726                      0,         // peer address type
4727                      null_addr, // peer bd addr
4728                      hci_stack->le_connection_own_addr_type,   // our addr type:
4729                      hci_stack->le_connection_interval_min,    // conn interval min
4730                      hci_stack->le_connection_interval_max,    // conn interval max
4731                      hci_stack->le_connection_latency,         // conn latency
4732                      hci_stack->le_supervision_timeout,        // conn latency
4733                      hci_stack->le_minimum_ce_length,          // min ce length
4734                      hci_stack->le_maximum_ce_length           // max ce length
4735         );
4736         return true;
4737     }
4738 #endif
4739 
4740 #ifdef ENABLE_LE_PERIPHERAL
4741     // re-start advertising
4742     if (hci_stack->le_advertisements_enabled_for_current_roles && !hci_stack->le_advertisements_active){
4743         // check if advertisements should be enabled given
4744         hci_stack->le_advertisements_active = true;
4745         hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, hci_stack->le_advertisements_own_address);
4746         hci_send_cmd(&hci_le_set_advertise_enable, 1);
4747         return true;
4748     }
4749 #endif
4750 
4751     return false;
4752 }
4753 #endif
4754 
4755 static bool hci_run_general_pending_commands(void){
4756     btstack_linked_item_t * it;
4757     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4758         hci_connection_t * connection = (hci_connection_t *) it;
4759 
4760         switch(connection->state){
4761             case SEND_CREATE_CONNECTION:
4762                 switch(connection->address_type){
4763 #ifdef ENABLE_CLASSIC
4764                     case BD_ADDR_TYPE_ACL:
4765                         log_info("sending hci_create_connection");
4766                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
4767                         break;
4768 #endif
4769                     default:
4770 #ifdef ENABLE_BLE
4771 #ifdef ENABLE_LE_CENTRAL
4772                         log_info("sending hci_le_create_connection");
4773                         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4774                         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4775                         hci_send_cmd(&hci_le_create_connection,
4776                                      hci_stack->le_connection_scan_interval,    // conn scan interval
4777                                      hci_stack->le_connection_scan_window,      // conn scan windows
4778                                      0,         // don't use whitelist
4779                                      connection->address_type, // peer address type
4780                                      connection->address,      // peer bd addr
4781                                      hci_stack->le_connection_own_addr_type,   // our addr type:
4782                                      hci_stack->le_connection_interval_min,    // conn interval min
4783                                      hci_stack->le_connection_interval_max,    // conn interval max
4784                                      hci_stack->le_connection_latency,         // conn latency
4785                                      hci_stack->le_supervision_timeout,        // conn latency
4786                                      hci_stack->le_minimum_ce_length,          // min ce length
4787                                      hci_stack->le_maximum_ce_length          // max ce length
4788                         );
4789                         connection->state = SENT_CREATE_CONNECTION;
4790 #endif
4791 #endif
4792                         break;
4793                 }
4794                 return true;
4795 
4796 #ifdef ENABLE_CLASSIC
4797             case RECEIVED_CONNECTION_REQUEST:
4798                 connection->role  = HCI_ROLE_SLAVE;
4799                 if (connection->address_type == BD_ADDR_TYPE_ACL){
4800                     log_info("sending hci_accept_connection_request");
4801                     connection->state = ACCEPTED_CONNECTION_REQUEST;
4802                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
4803                     return true;
4804                 }
4805                 break;
4806 #endif
4807 
4808 #ifdef ENABLE_BLE
4809 #ifdef ENABLE_LE_CENTRAL
4810             case SEND_CANCEL_CONNECTION:
4811                 connection->state = SENT_CANCEL_CONNECTION;
4812                 hci_send_cmd(&hci_le_create_connection_cancel);
4813                 return true;
4814 #endif
4815 #endif
4816             case SEND_DISCONNECT:
4817                 connection->state = SENT_DISCONNECT;
4818                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4819                 return true;
4820 
4821             default:
4822                 break;
4823         }
4824 
4825         // no further commands if connection is about to get shut down
4826         if (connection->state == SENT_DISCONNECT) continue;
4827 
4828         if (connection->authentication_flags & AUTH_FLAG_READ_RSSI){
4829             connectionClearAuthenticationFlags(connection, AUTH_FLAG_READ_RSSI);
4830             hci_send_cmd(&hci_read_rssi, connection->con_handle);
4831             return true;
4832         }
4833 
4834 #ifdef ENABLE_CLASSIC
4835 
4836         if (connection->authentication_flags & AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT){
4837             connectionClearAuthenticationFlags(connection, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
4838             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
4839             return true;
4840         }
4841 
4842         // Handling link key request requires remote supported features
4843         if (((connection->authentication_flags & AUTH_FLAG_HANDLE_LINK_KEY_REQUEST) != 0)){
4844             log_info("responding to link key request, have link key db: %u", hci_stack->link_key_db != NULL);
4845             connectionClearAuthenticationFlags(connection, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
4846 
4847             bool have_link_key = connection->link_key_type != INVALID_LINK_KEY;
4848             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(connection->link_key_type) >= connection->requested_security_level);
4849             if (have_link_key && security_level_sufficient){
4850                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &connection->link_key);
4851             } else {
4852                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
4853             }
4854             return true;
4855         }
4856 
4857         if (connection->authentication_flags & AUTH_FLAG_DENY_PIN_CODE_REQUEST){
4858             log_info("denying to pin request");
4859             connectionClearAuthenticationFlags(connection, AUTH_FLAG_DENY_PIN_CODE_REQUEST);
4860             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
4861             return true;
4862         }
4863 
4864         // security assessment requires remote features
4865         if ((connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST) != 0){
4866             connectionClearAuthenticationFlags(connection, AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
4867             hci_ssp_assess_security_on_io_cap_request(connection);
4868             // no return here as hci_ssp_assess_security_on_io_cap_request only sets AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY or AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY
4869         }
4870 
4871         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY){
4872             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
4873             // set authentication requirements:
4874             // - MITM = ssp_authentication_requirement (USER) | requested_security_level (dynamic)
4875             // - BONDING MODE: dedicated if requested, bondable otherwise. Drop bondable if not set for remote
4876             uint8_t authreq = hci_stack->ssp_authentication_requirement & 1;
4877             if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
4878                 authreq |= 1;
4879             }
4880             bool bonding = hci_stack->bondable;
4881             if (connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
4882                 // if we have received IO Cap Response, we're in responder role
4883                 bool remote_bonding = connection->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4884                 if (bonding && !remote_bonding){
4885                     log_info("Remote not bonding, dropping local flag");
4886                     bonding = false;
4887                 }
4888             }
4889             if (bonding){
4890                 if (connection->bonding_flags & BONDING_DEDICATED){
4891                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4892                 } else {
4893                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
4894                 }
4895             }
4896             uint8_t have_oob_data = 0;
4897 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4898             if (connection->classic_oob_c_192 != NULL){
4899                     have_oob_data |= 1;
4900             }
4901             if (connection->classic_oob_c_256 != NULL){
4902                 have_oob_data |= 2;
4903             }
4904 #endif
4905             hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, have_oob_data, authreq);
4906             return true;
4907         }
4908 
4909         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY) {
4910             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
4911             hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
4912             return true;
4913         }
4914 
4915 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4916         if (connection->authentication_flags & AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY){
4917             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
4918             const uint8_t zero[16] = { 0 };
4919             const uint8_t * r_192 = zero;
4920             const uint8_t * c_192 = zero;
4921             const uint8_t * r_256 = zero;
4922             const uint8_t * c_256 = zero;
4923             // verify P-256 OOB
4924             if ((connection->classic_oob_c_256 != NULL) && ((hci_stack->local_supported_commands[1] & 0x08u) != 0)) {
4925                 c_256 = connection->classic_oob_c_256;
4926                 if (connection->classic_oob_r_256 != NULL) {
4927                     r_256 = connection->classic_oob_r_256;
4928                 }
4929             }
4930             // verify P-192 OOB
4931             if ((connection->classic_oob_c_192 != NULL)) {
4932                 c_192 = connection->classic_oob_c_192;
4933                 if (connection->classic_oob_r_192 != NULL) {
4934                     r_192 = connection->classic_oob_r_192;
4935                 }
4936             }
4937 
4938             // assess security
4939             bool need_level_4 = hci_stack->gap_secure_connections_only_mode || (connection->requested_security_level == LEVEL_4);
4940             bool can_reach_level_4 = hci_remote_sc_enabled(connection) && (c_256 != NULL);
4941             if (need_level_4 && !can_reach_level_4){
4942                 log_info("Level 4 required, but not possible -> abort");
4943                 hci_pairing_complete(connection, ERROR_CODE_INSUFFICIENT_SECURITY);
4944                 // send oob negative reply
4945                 c_256 = NULL;
4946                 c_192 = NULL;
4947             }
4948 
4949             // Reply
4950             if (c_256 != zero) {
4951                 hci_send_cmd(&hci_remote_oob_extended_data_request_reply, &connection->address, c_192, r_192, c_256, r_256);
4952             } else if (c_192 != zero){
4953                 hci_send_cmd(&hci_remote_oob_data_request_reply, &connection->address, c_192, r_192);
4954             } else {
4955                 hci_stack->classic_oob_con_handle = connection->con_handle;
4956                 hci_send_cmd(&hci_remote_oob_data_request_negative_reply, &connection->address);
4957             }
4958             return true;
4959         }
4960 #endif
4961 
4962         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_REPLY){
4963             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
4964             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
4965             return true;
4966         }
4967 
4968         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY){
4969             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
4970             hci_send_cmd(&hci_user_confirmation_request_negative_reply, &connection->address);
4971             return true;
4972         }
4973 
4974         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_PASSKEY_REPLY){
4975             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
4976             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
4977             return true;
4978         }
4979 
4980         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
4981             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
4982             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
4983             connection->state = SENT_DISCONNECT;
4984             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4985             return true;
4986         }
4987 
4988         if ((connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST) && ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0)){
4989             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
4990             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
4991             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
4992             return true;
4993         }
4994 
4995         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
4996             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
4997             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
4998             return true;
4999         }
5000 
5001         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
5002             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
5003             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
5004             return true;
5005         }
5006 
5007         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
5008             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
5009             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
5010             return true;
5011         }
5012 
5013         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
5014             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
5015             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
5016             return true;
5017         }
5018 
5019         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
5020             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
5021             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
5022             return true;
5023         }
5024 #endif
5025 
5026         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
5027             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
5028 #ifdef ENABLE_CLASSIC
5029             hci_pairing_complete(connection, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_SECURITY_REASONS);
5030 #endif
5031             if (connection->state != SENT_DISCONNECT){
5032                 connection->state = SENT_DISCONNECT;
5033                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
5034                 return true;
5035             }
5036         }
5037 
5038 #ifdef ENABLE_CLASSIC
5039         uint16_t sniff_min_interval;
5040         switch (connection->sniff_min_interval){
5041             case 0:
5042                 break;
5043             case 0xffff:
5044                 connection->sniff_min_interval = 0;
5045                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
5046                 return true;
5047             default:
5048                 sniff_min_interval = connection->sniff_min_interval;
5049                 connection->sniff_min_interval = 0;
5050                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
5051                 return true;
5052         }
5053 
5054         if (connection->sniff_subrating_max_latency != 0xffff){
5055             uint16_t max_latency = connection->sniff_subrating_max_latency;
5056             connection->sniff_subrating_max_latency = 0;
5057             hci_send_cmd(&hci_sniff_subrating, connection->con_handle, max_latency, connection->sniff_subrating_min_remote_timeout, connection->sniff_subrating_min_local_timeout);
5058             return true;
5059         }
5060 
5061         if (connection->qos_service_type != HCI_SERVICE_TYPE_INVALID){
5062             uint8_t service_type = (uint8_t) connection->qos_service_type;
5063             connection->qos_service_type = HCI_SERVICE_TYPE_INVALID;
5064             hci_send_cmd(&hci_qos_setup, connection->con_handle, 0, service_type, connection->qos_token_rate, connection->qos_peak_bandwidth, connection->qos_latency, connection->qos_delay_variation);
5065             return true;
5066         }
5067 
5068         if (connection->request_role != HCI_ROLE_INVALID){
5069             hci_role_t role = connection->request_role;
5070             connection->request_role = HCI_ROLE_INVALID;
5071             hci_send_cmd(&hci_switch_role_command, connection->address, role);
5072             return true;
5073         }
5074 #endif
5075 
5076 #ifdef ENABLE_BLE
5077         switch (connection->le_con_parameter_update_state){
5078             // response to L2CAP CON PARAMETER UPDATE REQUEST
5079             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
5080                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
5081                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
5082                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
5083                              0x0000, 0xffff);
5084                 return true;
5085             case CON_PARAMETER_UPDATE_REPLY:
5086                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
5087                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
5088                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
5089                              0x0000, 0xffff);
5090                 return true;
5091             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
5092                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
5093                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
5094                 return true;
5095             default:
5096                 break;
5097         }
5098         if (connection->le_phy_update_all_phys != 0xffu){
5099             uint8_t all_phys = connection->le_phy_update_all_phys;
5100             connection->le_phy_update_all_phys = 0xff;
5101             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);
5102             return true;
5103         }
5104 #endif
5105     }
5106     return false;
5107 }
5108 
5109 static void hci_run(void){
5110 
5111     // stack state sub statemachines
5112     // halting needs to be called even if we cannot send command packet now
5113     switch (hci_stack->state) {
5114         case HCI_STATE_INITIALIZING:
5115             hci_initializing_run();
5116             break;
5117         case HCI_STATE_HALTING:
5118             hci_halting_run();
5119             break;
5120         case HCI_STATE_FALLING_ASLEEP:
5121             hci_falling_asleep_run();
5122             break;
5123         default:
5124             break;
5125     }
5126 
5127     bool done;
5128 
5129     // send continuation fragments first, as they block the prepared packet buffer
5130     done = hci_run_acl_fragments();
5131     if (done) return;
5132 
5133 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
5134     // send host num completed packets next as they don't require num_cmd_packets > 0
5135     if (!hci_can_send_comand_packet_transport()) return;
5136     if (hci_stack->host_completed_packets){
5137         hci_host_num_completed_packets();
5138         return;
5139     }
5140 #endif
5141 
5142     if (!hci_can_send_command_packet_now()) return;
5143 
5144     // global/non-connection oriented commands
5145 
5146 
5147 #ifdef ENABLE_CLASSIC
5148     // general gap classic
5149     done = hci_run_general_gap_classic();
5150     if (done) return;
5151 #endif
5152 
5153 #ifdef ENABLE_BLE
5154     // general gap le
5155     done = hci_run_general_gap_le();
5156     if (done) return;
5157 #endif
5158 
5159     // send pending HCI commands
5160     hci_run_general_pending_commands();
5161 }
5162 
5163 uint8_t hci_send_cmd_packet(uint8_t *packet, int size){
5164     // house-keeping
5165 
5166 #ifdef ENABLE_CLASSIC
5167     bd_addr_t addr;
5168     hci_connection_t * conn;
5169 #endif
5170 #ifdef ENABLE_LE_CENTRAL
5171     uint8_t initiator_filter_policy;
5172 #endif
5173 
5174     uint16_t opcode = little_endian_read_16(packet, 0);
5175     switch (opcode) {
5176         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
5177             hci_stack->loopback_mode = packet[3];
5178             break;
5179 
5180 #ifdef ENABLE_CLASSIC
5181         case HCI_OPCODE_HCI_CREATE_CONNECTION:
5182             reverse_bd_addr(&packet[3], addr);
5183             log_info("Create_connection to %s", bd_addr_to_str(addr));
5184 
5185             // CVE-2020-26555: reject outgoing connection to device with same BD ADDR
5186             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0) {
5187                 hci_emit_connection_complete(addr, 0, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR);
5188                 return ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
5189             }
5190 
5191             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5192             if (!conn) {
5193                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5194                 if (!conn) {
5195                     // notify client that alloc failed
5196                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5197                     return BTSTACK_MEMORY_ALLOC_FAILED; // packet not sent to controller
5198                 }
5199                 conn->state = SEND_CREATE_CONNECTION;
5200                 conn->role  = HCI_ROLE_MASTER;
5201             }
5202 
5203             conn->con_handle = HCI_CON_HANDLE_INVALID;
5204             conn->role = HCI_ROLE_INVALID;
5205 
5206             log_info("conn state %u", conn->state);
5207             // TODO: L2CAP should not send create connection command, instead a (new) gap function should be used
5208             switch (conn->state) {
5209                 // if connection active exists
5210                 case OPEN:
5211                     // and OPEN, emit connection complete command
5212                     hci_emit_connection_complete(addr, conn->con_handle, ERROR_CODE_SUCCESS);
5213                     // packet not sent to controller
5214                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5215                 case RECEIVED_DISCONNECTION_COMPLETE:
5216                     // create connection triggered in disconnect complete event, let's do it now
5217                     break;
5218                 case SEND_CREATE_CONNECTION:
5219                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
5220                     break;
5221                 default:
5222                     // otherwise, just ignore as it is already in the open process
5223                     // packet not sent to controller
5224                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5225             }
5226             conn->state = SENT_CREATE_CONNECTION;
5227 
5228             // track outgoing connection
5229             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
5230             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
5231             break;
5232 
5233 #if defined (ENABLE_SCO_OVER_HCI) || defined (HAVE_SCO_TRANSPORT)
5234         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
5235             // setup_synchronous_connection? Voice setting at offset 22
5236             // TODO: compare to current setting if sco connection already active
5237             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
5238             break;
5239         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
5240             // accept_synchronous_connection? Voice setting at offset 18
5241             // TODO: compare to current setting if sco connection already active
5242             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
5243             // track outgoing connection
5244             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_SCO;
5245             reverse_bd_addr(&packet[3], hci_stack->outgoing_addr);
5246             break;
5247 #endif
5248 #endif
5249 
5250 #ifdef ENABLE_BLE
5251 #ifdef ENABLE_LE_CENTRAL
5252         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
5253             // white list used?
5254             initiator_filter_policy = packet[7];
5255             switch (initiator_filter_policy) {
5256                 case 0:
5257                     // whitelist not used
5258                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
5259                     break;
5260                 case 1:
5261                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
5262                     break;
5263                 default:
5264                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
5265                     break;
5266             }
5267             // track outgoing connection
5268             hci_stack->outgoing_addr_type = (bd_addr_type_t) packet[8]; // peer addres type
5269             reverse_bd_addr( &packet[9], hci_stack->outgoing_addr); // peer address
5270             break;
5271         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
5272             hci_stack->le_connecting_state = LE_CONNECTING_CANCEL;
5273             break;
5274 #endif
5275 #endif
5276         default:
5277             break;
5278     }
5279 
5280     hci_stack->num_cmd_packets--;
5281 
5282     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
5283     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
5284     if (err != 0){
5285         return ERROR_CODE_HARDWARE_FAILURE;
5286     }
5287     return ERROR_CODE_SUCCESS;
5288 }
5289 
5290 // disconnect because of security block
5291 void hci_disconnect_security_block(hci_con_handle_t con_handle){
5292     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5293     if (!connection) return;
5294     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
5295 }
5296 
5297 
5298 // Configure Secure Simple Pairing
5299 
5300 #ifdef ENABLE_CLASSIC
5301 
5302 // enable will enable SSP during init
5303 void gap_ssp_set_enable(int enable){
5304     hci_stack->ssp_enable = enable;
5305 }
5306 
5307 static int hci_local_ssp_activated(void){
5308     return gap_ssp_supported() && hci_stack->ssp_enable;
5309 }
5310 
5311 // if set, BTstack will respond to io capability request using authentication requirement
5312 void gap_ssp_set_io_capability(int io_capability){
5313     hci_stack->ssp_io_capability = io_capability;
5314 }
5315 void gap_ssp_set_authentication_requirement(int authentication_requirement){
5316     hci_stack->ssp_authentication_requirement = authentication_requirement;
5317 }
5318 
5319 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
5320 void gap_ssp_set_auto_accept(int auto_accept){
5321     hci_stack->ssp_auto_accept = auto_accept;
5322 }
5323 
5324 void gap_secure_connections_enable(bool enable){
5325     hci_stack->secure_connections_enable = enable;
5326 }
5327 
5328 #endif
5329 
5330 // va_list part of hci_send_cmd
5331 uint8_t hci_send_cmd_va_arg(const hci_cmd_t * cmd, va_list argptr){
5332     if (!hci_can_send_command_packet_now()){
5333         log_error("hci_send_cmd called but cannot send packet now");
5334         return ERROR_CODE_COMMAND_DISALLOWED;
5335     }
5336 
5337     // for HCI INITIALIZATION
5338     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
5339     hci_stack->last_cmd_opcode = cmd->opcode;
5340 
5341     hci_reserve_packet_buffer();
5342     uint8_t * packet = hci_stack->hci_packet_buffer;
5343     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
5344     uint8_t status = hci_send_cmd_packet(packet, size);
5345 
5346     // release packet buffer on error or for synchronous transport implementations
5347     if ((status != ERROR_CODE_SUCCESS) || hci_transport_synchronous()){
5348         hci_release_packet_buffer();
5349         hci_emit_transport_packet_sent();
5350     }
5351 
5352     return status;
5353 }
5354 
5355 /**
5356  * pre: numcmds >= 0 - it's allowed to send a command to the controller
5357  */
5358 uint8_t hci_send_cmd(const hci_cmd_t * cmd, ...){
5359     va_list argptr;
5360     va_start(argptr, cmd);
5361     uint8_t status = hci_send_cmd_va_arg(cmd, argptr);
5362     va_end(argptr);
5363     return status;
5364 }
5365 
5366 // Create various non-HCI events.
5367 // TODO: generalize, use table similar to hci_create_command
5368 
5369 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
5370     // dump packet
5371     if (dump) {
5372         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
5373     }
5374 
5375     // dispatch to all event handlers
5376     btstack_linked_list_iterator_t it;
5377     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
5378     while (btstack_linked_list_iterator_has_next(&it)){
5379         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
5380         entry->callback(HCI_EVENT_PACKET, 0, event, size);
5381     }
5382 }
5383 
5384 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
5385     if (!hci_stack->acl_packet_handler) return;
5386     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
5387 }
5388 
5389 #ifdef ENABLE_CLASSIC
5390 static void hci_notify_if_sco_can_send_now(void){
5391     // notify SCO sender if waiting
5392     if (!hci_stack->sco_waiting_for_can_send_now) return;
5393     if (hci_can_send_sco_packet_now()){
5394         hci_stack->sco_waiting_for_can_send_now = 0;
5395         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
5396         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
5397         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
5398     }
5399 }
5400 
5401 // parsing end emitting has been merged to reduce code size
5402 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
5403     uint8_t event[28+GAP_INQUIRY_MAX_NAME_LEN];
5404 
5405     uint8_t * eir_data;
5406     ad_context_t context;
5407     const uint8_t * name;
5408     uint8_t         name_len;
5409 
5410     if (size < 3) return;
5411 
5412     int event_type = hci_event_packet_get_type(packet);
5413     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
5414     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
5415 
5416     switch (event_type){
5417         case HCI_EVENT_INQUIRY_RESULT:
5418         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5419             if (size != (3 + (num_responses * 14))) return;
5420             break;
5421         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5422             if (size != 257) return;
5423             if (num_responses != 1) return;
5424             break;
5425         default:
5426             return;
5427     }
5428 
5429     // event[1] is set at the end
5430     int i;
5431     for (i=0; i<num_responses;i++){
5432         memset(event, 0, sizeof(event));
5433         event[0] = GAP_EVENT_INQUIRY_RESULT;
5434         uint8_t event_size = 27;    // if name is not set by EIR
5435 
5436         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
5437         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
5438         (void)memcpy(&event[9],
5439                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
5440                      3); // class of device
5441         (void)memcpy(&event[12],
5442                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
5443                      2); // clock offset
5444 
5445         switch (event_type){
5446             case HCI_EVENT_INQUIRY_RESULT:
5447                 // 14,15,16,17 = 0, size 18
5448                 break;
5449             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5450                 event[14] = 1;
5451                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5452                 // 16,17 = 0, size 18
5453                 break;
5454             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5455                 event[14] = 1;
5456                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5457                 // EIR packets only contain a single inquiry response
5458                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
5459                 name = NULL;
5460                 // Iterate over EIR data
5461                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
5462                     uint8_t data_type    = ad_iterator_get_data_type(&context);
5463                     uint8_t data_size    = ad_iterator_get_data_len(&context);
5464                     const uint8_t * data = ad_iterator_get_data(&context);
5465                     // Prefer Complete Local Name over Shortened Local Name
5466                     switch (data_type){
5467                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
5468                             if (name) continue;
5469                             /* fall through */
5470                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
5471                             name = data;
5472                             name_len = data_size;
5473                             break;
5474                         case BLUETOOTH_DATA_TYPE_DEVICE_ID:
5475                             if (data_size != 8) break;
5476                             event[16] = 1;
5477                             memcpy(&event[17], data, 8);
5478                             break;
5479                         default:
5480                             break;
5481                     }
5482                 }
5483                 if (name){
5484                     event[25] = 1;
5485                     // truncate name if needed
5486                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
5487                     event[26] = len;
5488                     (void)memcpy(&event[27], name, len);
5489                     event_size += len;
5490                 }
5491                 break;
5492             default:
5493                 return;
5494         }
5495         event[1] = event_size - 2;
5496         hci_emit_event(event, event_size, 1);
5497     }
5498 }
5499 #endif
5500 
5501 void hci_emit_state(void){
5502     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
5503     uint8_t event[3];
5504     event[0] = BTSTACK_EVENT_STATE;
5505     event[1] = sizeof(event) - 2u;
5506     event[2] = hci_stack->state;
5507     hci_emit_event(event, sizeof(event), 1);
5508 }
5509 
5510 #ifdef ENABLE_CLASSIC
5511 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5512     uint8_t event[13];
5513     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
5514     event[1] = sizeof(event) - 2;
5515     event[2] = status;
5516     little_endian_store_16(event, 3, con_handle);
5517     reverse_bd_addr(address, &event[5]);
5518     event[11] = 1; // ACL connection
5519     event[12] = 0; // encryption disabled
5520     hci_emit_event(event, sizeof(event), 1);
5521 }
5522 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
5523     if (disable_l2cap_timeouts) return;
5524     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
5525     uint8_t event[4];
5526     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
5527     event[1] = sizeof(event) - 2;
5528     little_endian_store_16(event, 2, conn->con_handle);
5529     hci_emit_event(event, sizeof(event), 1);
5530 }
5531 #endif
5532 
5533 #ifdef ENABLE_BLE
5534 #ifdef ENABLE_LE_CENTRAL
5535 static void hci_emit_le_connection_complete(uint8_t address_type, const bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5536     uint8_t event[21];
5537     event[0] = HCI_EVENT_LE_META;
5538     event[1] = sizeof(event) - 2u;
5539     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
5540     event[3] = status;
5541     little_endian_store_16(event, 4, con_handle);
5542     event[6] = 0; // TODO: role
5543     event[7] = address_type;
5544     reverse_bd_addr(address, &event[8]);
5545     little_endian_store_16(event, 14, 0); // interval
5546     little_endian_store_16(event, 16, 0); // latency
5547     little_endian_store_16(event, 18, 0); // supervision timeout
5548     event[20] = 0; // master clock accuracy
5549     hci_emit_event(event, sizeof(event), 1);
5550 }
5551 #endif
5552 #endif
5553 
5554 static void hci_emit_transport_packet_sent(void){
5555     // notify upper stack that it might be possible to send again
5556     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
5557     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
5558 }
5559 
5560 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
5561     uint8_t event[6];
5562     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
5563     event[1] = sizeof(event) - 2u;
5564     event[2] = 0; // status = OK
5565     little_endian_store_16(event, 3, con_handle);
5566     event[5] = reason;
5567     hci_emit_event(event, sizeof(event), 1);
5568 }
5569 
5570 static void hci_emit_nr_connections_changed(void){
5571     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
5572     uint8_t event[3];
5573     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
5574     event[1] = sizeof(event) - 2u;
5575     event[2] = nr_hci_connections();
5576     hci_emit_event(event, sizeof(event), 1);
5577 }
5578 
5579 static void hci_emit_hci_open_failed(void){
5580     log_info("BTSTACK_EVENT_POWERON_FAILED");
5581     uint8_t event[2];
5582     event[0] = BTSTACK_EVENT_POWERON_FAILED;
5583     event[1] = sizeof(event) - 2u;
5584     hci_emit_event(event, sizeof(event), 1);
5585 }
5586 
5587 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
5588     log_info("hci_emit_dedicated_bonding_result %u ", status);
5589     uint8_t event[9];
5590     int pos = 0;
5591     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
5592     event[pos++] = sizeof(event) - 2u;
5593     event[pos++] = status;
5594     reverse_bd_addr(address, &event[pos]);
5595     hci_emit_event(event, sizeof(event), 1);
5596 }
5597 
5598 
5599 #ifdef ENABLE_CLASSIC
5600 
5601 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
5602     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
5603     uint8_t event[5];
5604     int pos = 0;
5605     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
5606     event[pos++] = sizeof(event) - 2;
5607     little_endian_store_16(event, 2, con_handle);
5608     pos += 2;
5609     event[pos++] = level;
5610     hci_emit_event(event, sizeof(event), 1);
5611 }
5612 
5613 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
5614     if (!connection) return LEVEL_0;
5615     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
5616     // BIAS: we only consider Authenticated if the connection is already encrypted, which requires that both sides have link key
5617     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
5618     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
5619     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
5620     // LEVEL 4 always requires 128 bit encrytion key size
5621     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
5622         security_level = LEVEL_3;
5623     }
5624     return security_level;
5625 }
5626 
5627 static void hci_emit_discoverable_enabled(uint8_t enabled){
5628     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
5629     uint8_t event[3];
5630     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
5631     event[1] = sizeof(event) - 2;
5632     event[2] = enabled;
5633     hci_emit_event(event, sizeof(event), 1);
5634 }
5635 
5636 // query if remote side supports eSCO
5637 bool hci_remote_esco_supported(hci_con_handle_t con_handle){
5638     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5639     if (!connection) return false;
5640     return (connection->remote_supported_features[0] & 1) != 0;
5641 }
5642 
5643 static bool hci_ssp_supported(hci_connection_t * connection){
5644     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
5645     return (connection->bonding_flags & mask) == mask;
5646 }
5647 
5648 // query if remote side supports SSP
5649 bool hci_remote_ssp_supported(hci_con_handle_t con_handle){
5650     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5651     if (!connection) return false;
5652     return hci_ssp_supported(connection) ? 1 : 0;
5653 }
5654 
5655 bool gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
5656     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
5657 }
5658 
5659 /**
5660  * Check if remote supported features query has completed
5661  */
5662 bool hci_remote_features_available(hci_con_handle_t handle){
5663     hci_connection_t * connection = hci_connection_for_handle(handle);
5664     if (!connection) return false;
5665     return (connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0;
5666 }
5667 
5668 /**
5669  * Trigger remote supported features query
5670  */
5671 
5672 static void hci_trigger_remote_features_for_connection(hci_connection_t * connection){
5673     if ((connection->bonding_flags & (BONDING_REMOTE_FEATURES_QUERY_ACTIVE | BONDING_RECEIVED_REMOTE_FEATURES)) == 0){
5674         connection->bonding_flags |= BONDING_REMOTE_FEATURES_QUERY_ACTIVE | BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
5675     }
5676 }
5677 
5678 void hci_remote_features_query(hci_con_handle_t con_handle){
5679     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5680     if (!connection) return;
5681     hci_trigger_remote_features_for_connection(connection);
5682     hci_run();
5683 }
5684 
5685 // GAP API
5686 /**
5687  * @bbrief enable/disable bonding. default is enabled
5688  * @praram enabled
5689  */
5690 void gap_set_bondable_mode(int enable){
5691     hci_stack->bondable = enable ? 1 : 0;
5692 }
5693 /**
5694  * @brief Get bondable mode.
5695  * @return 1 if bondable
5696  */
5697 int gap_get_bondable_mode(void){
5698     return hci_stack->bondable;
5699 }
5700 
5701 /**
5702  * @brief map link keys to security levels
5703  */
5704 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
5705     switch (link_key_type){
5706         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5707             return LEVEL_4;
5708         case COMBINATION_KEY:
5709         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5710             return LEVEL_3;
5711         default:
5712             return LEVEL_2;
5713     }
5714 }
5715 
5716 /**
5717  * @brief map link keys to secure connection yes/no
5718  */
5719 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
5720     switch (link_key_type){
5721         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5722         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5723             return 1;
5724         default:
5725             return 0;
5726     }
5727 }
5728 
5729 /**
5730  * @brief map link keys to authenticated
5731  */
5732 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
5733     switch (link_key_type){
5734         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5735         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5736             return 1;
5737         default:
5738             return 0;
5739     }
5740 }
5741 
5742 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
5743     log_info("gap_mitm_protection_required_for_security_level %u", level);
5744     return level > LEVEL_2;
5745 }
5746 
5747 /**
5748  * @brief get current security level
5749  */
5750 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
5751     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5752     if (!connection) return LEVEL_0;
5753     return gap_security_level_for_connection(connection);
5754 }
5755 
5756 /**
5757  * @brief request connection to device to
5758  * @result GAP_AUTHENTICATION_RESULT
5759  */
5760 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
5761     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5762     if (!connection){
5763         hci_emit_security_level(con_handle, LEVEL_0);
5764         return;
5765     }
5766 
5767     btstack_assert(hci_is_le_connection(connection) == false);
5768 
5769     // Core Spec 5.2, GAP 5.2.2: "When in Secure Connections Only mode, all services (except those allowed to have Security Mode 4, Level 0)
5770     // available on the BR/EDR physical transport require Security Mode 4, Level 4 "
5771     if (hci_stack->gap_secure_connections_only_mode && (requested_level != LEVEL_0)){
5772         requested_level = LEVEL_4;
5773     }
5774 
5775     gap_security_level_t current_level = gap_security_level(con_handle);
5776     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
5777         requested_level, connection->requested_security_level, current_level);
5778 
5779     // authentication active if authentication request was sent or planned level > 0
5780     bool authentication_active = ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) || (connection->requested_security_level > LEVEL_0);
5781     if (authentication_active){
5782         // authentication already active
5783         if (connection->requested_security_level < requested_level){
5784             // increase requested level as new level is higher
5785             // TODO: handle re-authentication when done
5786             connection->requested_security_level = requested_level;
5787         }
5788     } else {
5789         // no request active, notify if security sufficient
5790         if (requested_level <= current_level){
5791             hci_emit_security_level(con_handle, current_level);
5792             return;
5793         }
5794 
5795         // store request
5796         connection->requested_security_level = requested_level;
5797 
5798         // request remote features if not already active
5799         hci_remote_features_query(con_handle);
5800 
5801         // start to authenticate connection
5802         connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
5803         hci_run();
5804     }
5805 }
5806 
5807 /**
5808  * @brief start dedicated bonding with device. disconnect after bonding
5809  * @param device
5810  * @param request MITM protection
5811  * @result GAP_DEDICATED_BONDING_COMPLETE
5812  */
5813 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
5814 
5815     // create connection state machine
5816     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
5817 
5818     if (!connection){
5819         return BTSTACK_MEMORY_ALLOC_FAILED;
5820     }
5821 
5822     // delete linkn key
5823     gap_drop_link_key_for_bd_addr(device);
5824 
5825     // configure LEVEL_2/3, dedicated bonding
5826     connection->state = SEND_CREATE_CONNECTION;
5827     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
5828     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
5829     connection->bonding_flags = BONDING_DEDICATED;
5830 
5831     // wait for GAP Security Result and send GAP Dedicated Bonding complete
5832 
5833     // handle: connnection failure (connection complete != ok)
5834     // handle: authentication failure
5835     // handle: disconnect on done
5836 
5837     hci_run();
5838 
5839     return 0;
5840 }
5841 
5842 void gap_set_local_name(const char * local_name){
5843     hci_stack->local_name = local_name;
5844     hci_stack->gap_tasks |= GAP_TASK_SET_LOCAL_NAME;
5845     // also update EIR if not set by user
5846     if (hci_stack->eir_data == NULL){
5847         hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
5848     }
5849     hci_run();
5850 }
5851 #endif
5852 
5853 
5854 #ifdef ENABLE_BLE
5855 
5856 #ifdef ENABLE_LE_CENTRAL
5857 void gap_start_scan(void){
5858     hci_stack->le_scanning_enabled = true;
5859     hci_run();
5860 }
5861 
5862 void gap_stop_scan(void){
5863     hci_stack->le_scanning_enabled = false;
5864     hci_run();
5865 }
5866 
5867 void gap_set_scan_params(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window, uint8_t scanning_filter_policy){
5868     hci_stack->le_scan_type          = scan_type;
5869     hci_stack->le_scan_filter_policy = scanning_filter_policy;
5870     hci_stack->le_scan_interval      = scan_interval;
5871     hci_stack->le_scan_window        = scan_window;
5872     hci_stack->le_scanning_param_update = true;
5873     hci_run();
5874 }
5875 
5876 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
5877     gap_set_scan_params(scan_type, scan_interval, scan_window, 0);
5878 }
5879 
5880 uint8_t gap_connect(const bd_addr_t addr, bd_addr_type_t addr_type){
5881     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
5882     if (!conn){
5883         // disallow if le connection is already outgoing
5884         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5885             log_error("le connection already active");
5886             return ERROR_CODE_COMMAND_DISALLOWED;
5887         }
5888 
5889         log_info("gap_connect: no connection exists yet, creating context");
5890         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
5891         if (!conn){
5892             // notify client that alloc failed
5893             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5894             log_info("gap_connect: failed to alloc hci_connection_t");
5895             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
5896         }
5897 
5898         // set le connecting state
5899         if (hci_is_le_connection_type(addr_type)){
5900             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
5901         }
5902 
5903         conn->state = SEND_CREATE_CONNECTION;
5904         log_info("gap_connect: send create connection next");
5905         hci_run();
5906         return ERROR_CODE_SUCCESS;
5907     }
5908 
5909     if (!hci_is_le_connection(conn) ||
5910         (conn->state == SEND_CREATE_CONNECTION) ||
5911         (conn->state == SENT_CREATE_CONNECTION)) {
5912         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
5913         log_error("gap_connect: classic connection or connect is already being created");
5914         return GATT_CLIENT_IN_WRONG_STATE;
5915     }
5916 
5917     // check if connection was just disconnected
5918     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5919         log_info("gap_connect: send create connection (again)");
5920         conn->state = SEND_CREATE_CONNECTION;
5921         hci_run();
5922         return ERROR_CODE_SUCCESS;
5923     }
5924 
5925     log_info("gap_connect: context exists with state %u", conn->state);
5926     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
5927     hci_run();
5928     return ERROR_CODE_SUCCESS;
5929 }
5930 
5931 // @assumption: only a single outgoing LE Connection exists
5932 static hci_connection_t * gap_get_outgoing_connection(void){
5933     btstack_linked_item_t *it;
5934     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5935         hci_connection_t * conn = (hci_connection_t *) it;
5936         if (!hci_is_le_connection(conn)) continue;
5937         switch (conn->state){
5938             case SEND_CREATE_CONNECTION:
5939             case SENT_CREATE_CONNECTION:
5940             case SENT_CANCEL_CONNECTION:
5941                 return conn;
5942             default:
5943                 break;
5944         };
5945     }
5946     return NULL;
5947 }
5948 
5949 uint8_t gap_connect_cancel(void){
5950     hci_connection_t * conn = gap_get_outgoing_connection();
5951     if (!conn) return 0;
5952     switch (conn->state){
5953         case SEND_CREATE_CONNECTION:
5954             // skip sending create connection and emit event instead
5955             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5956             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5957             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5958             btstack_memory_hci_connection_free( conn );
5959             break;
5960         case SENT_CREATE_CONNECTION:
5961             // request to send cancel connection
5962             conn->state = SEND_CANCEL_CONNECTION;
5963             hci_run();
5964             break;
5965         default:
5966             break;
5967     }
5968     return 0;
5969 }
5970 #endif
5971 
5972 #ifdef ENABLE_LE_CENTRAL
5973 /**
5974  * @brief Set connection parameters for outgoing connections
5975  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5976  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5977  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5978  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5979  * @param conn_latency, default: 4
5980  * @param supervision_timeout (unit: 10ms), default: 720 ms
5981  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5982  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5983  */
5984 
5985 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5986     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5987     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5988     hci_stack->le_connection_scan_interval = conn_scan_interval;
5989     hci_stack->le_connection_scan_window = conn_scan_window;
5990     hci_stack->le_connection_interval_min = conn_interval_min;
5991     hci_stack->le_connection_interval_max = conn_interval_max;
5992     hci_stack->le_connection_latency = conn_latency;
5993     hci_stack->le_supervision_timeout = supervision_timeout;
5994     hci_stack->le_minimum_ce_length = min_ce_length;
5995     hci_stack->le_maximum_ce_length = max_ce_length;
5996 }
5997 #endif
5998 
5999 /**
6000  * @brief Updates the connection parameters for a given LE connection
6001  * @param handle
6002  * @param conn_interval_min (unit: 1.25ms)
6003  * @param conn_interval_max (unit: 1.25ms)
6004  * @param conn_latency
6005  * @param supervision_timeout (unit: 10ms)
6006  * @return 0 if ok
6007  */
6008 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
6009     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
6010     hci_connection_t * connection = hci_connection_for_handle(con_handle);
6011     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6012     connection->le_conn_interval_min = conn_interval_min;
6013     connection->le_conn_interval_max = conn_interval_max;
6014     connection->le_conn_latency = conn_latency;
6015     connection->le_supervision_timeout = supervision_timeout;
6016     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
6017     hci_run();
6018     return 0;
6019 }
6020 
6021 /**
6022  * @brief Request an update of the connection parameter for a given LE connection
6023  * @param handle
6024  * @param conn_interval_min (unit: 1.25ms)
6025  * @param conn_interval_max (unit: 1.25ms)
6026  * @param conn_latency
6027  * @param supervision_timeout (unit: 10ms)
6028  * @return 0 if ok
6029  */
6030 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
6031     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
6032     hci_connection_t * connection = hci_connection_for_handle(con_handle);
6033     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6034     connection->le_conn_interval_min = conn_interval_min;
6035     connection->le_conn_interval_max = conn_interval_max;
6036     connection->le_conn_latency = conn_latency;
6037     connection->le_supervision_timeout = supervision_timeout;
6038     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
6039     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
6040     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
6041     return 0;
6042 }
6043 
6044 #ifdef ENABLE_LE_PERIPHERAL
6045 
6046 /**
6047  * @brief Set Advertisement Data
6048  * @param advertising_data_length
6049  * @param advertising_data (max 31 octets)
6050  * @note data is not copied, pointer has to stay valid
6051  */
6052 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
6053     hci_stack->le_advertisements_data_len = advertising_data_length;
6054     hci_stack->le_advertisements_data = advertising_data;
6055     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
6056     hci_run();
6057 }
6058 
6059 /**
6060  * @brief Set Scan Response Data
6061  * @param advertising_data_length
6062  * @param advertising_data (max 31 octets)
6063  * @note data is not copied, pointer has to stay valid
6064  */
6065 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
6066     hci_stack->le_scan_response_data_len = scan_response_data_length;
6067     hci_stack->le_scan_response_data = scan_response_data;
6068     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
6069     hci_run();
6070 }
6071 
6072 /**
6073  * @brief Set Advertisement Parameters
6074  * @param adv_int_min
6075  * @param adv_int_max
6076  * @param adv_type
6077  * @param direct_address_type
6078  * @param direct_address
6079  * @param channel_map
6080  * @param filter_policy
6081  *
6082  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
6083  */
6084  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
6085     uint8_t direct_address_typ, bd_addr_t direct_address,
6086     uint8_t channel_map, uint8_t filter_policy) {
6087 
6088     hci_stack->le_advertisements_interval_min = adv_int_min;
6089     hci_stack->le_advertisements_interval_max = adv_int_max;
6090     hci_stack->le_advertisements_type = adv_type;
6091     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
6092     hci_stack->le_advertisements_channel_map = channel_map;
6093     hci_stack->le_advertisements_filter_policy = filter_policy;
6094     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
6095                  6);
6096 
6097     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS | LE_ADVERTISEMENT_TASKS_PARAMS_SET;
6098     hci_run();
6099  }
6100 
6101 /**
6102  * @brief Enable/Disable Advertisements
6103  * @param enabled
6104  */
6105 void gap_advertisements_enable(int enabled){
6106     hci_stack->le_advertisements_enabled = enabled != 0;
6107     hci_update_advertisements_enabled_for_current_roles();
6108     hci_run();
6109 }
6110 
6111 #endif
6112 
6113 void hci_le_set_own_address_type(uint8_t own_address_type){
6114     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
6115     if (own_address_type == hci_stack->le_own_addr_type) return;
6116     hci_stack->le_own_addr_type = own_address_type;
6117 
6118 #ifdef ENABLE_LE_PERIPHERAL
6119     // update advertisement parameters, too
6120     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
6121     hci_run();
6122 #endif
6123 #ifdef ENABLE_LE_CENTRAL
6124     // note: we don't update scan parameters or modify ongoing connection attempts
6125 #endif
6126 }
6127 
6128 void hci_le_random_address_set(const bd_addr_t random_address){
6129     memcpy(hci_stack->le_random_address, random_address, 6);
6130     hci_stack->le_random_address_set = true;
6131     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADDRESS;
6132     hci_run();
6133 }
6134 
6135 #endif
6136 
6137 uint8_t gap_disconnect(hci_con_handle_t handle){
6138     hci_connection_t * conn = hci_connection_for_handle(handle);
6139     if (!conn){
6140         hci_emit_disconnection_complete(handle, 0);
6141         return 0;
6142     }
6143     // ignore if already disconnected
6144     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
6145         return 0;
6146     }
6147     conn->state = SEND_DISCONNECT;
6148     hci_run();
6149     return 0;
6150 }
6151 
6152 int gap_read_rssi(hci_con_handle_t con_handle){
6153     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6154     if (hci_connection == NULL) return 0;
6155     connectionSetAuthenticationFlags(hci_connection, AUTH_FLAG_READ_RSSI);
6156     hci_run();
6157     return 1;
6158 }
6159 
6160 /**
6161  * @brief Get connection type
6162  * @param con_handle
6163  * @result connection_type
6164  */
6165 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
6166     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6167     if (!conn) return GAP_CONNECTION_INVALID;
6168     switch (conn->address_type){
6169         case BD_ADDR_TYPE_LE_PUBLIC:
6170         case BD_ADDR_TYPE_LE_RANDOM:
6171             return GAP_CONNECTION_LE;
6172         case BD_ADDR_TYPE_SCO:
6173             return GAP_CONNECTION_SCO;
6174         case BD_ADDR_TYPE_ACL:
6175             return GAP_CONNECTION_ACL;
6176         default:
6177             return GAP_CONNECTION_INVALID;
6178     }
6179 }
6180 
6181 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
6182     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6183     if (!conn) return HCI_ROLE_INVALID;
6184     return (hci_role_t) conn->role;
6185 }
6186 
6187 
6188 #ifdef ENABLE_CLASSIC
6189 uint8_t gap_request_role(const bd_addr_t addr, hci_role_t role){
6190     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6191     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6192     conn->request_role = role;
6193     hci_run();
6194     return ERROR_CODE_SUCCESS;
6195 }
6196 #endif
6197 
6198 #ifdef ENABLE_BLE
6199 
6200 uint8_t gap_le_set_phy(hci_con_handle_t con_handle, uint8_t all_phys, uint8_t tx_phys, uint8_t rx_phys, uint8_t phy_options){
6201     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6202     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6203 
6204     conn->le_phy_update_all_phys    = all_phys;
6205     conn->le_phy_update_tx_phys     = tx_phys;
6206     conn->le_phy_update_rx_phys     = rx_phys;
6207     conn->le_phy_update_phy_options = phy_options;
6208 
6209     hci_run();
6210 
6211     return 0;
6212 }
6213 
6214 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6215     // check if already in list
6216     btstack_linked_list_iterator_t it;
6217     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6218     while (btstack_linked_list_iterator_has_next(&it)) {
6219         whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&it);
6220         if (entry->address_type != address_type) {
6221             continue;
6222         }
6223         if (memcmp(entry->address, address, 6) != 0) {
6224             continue;
6225         }
6226 		// disallow if already scheduled to add
6227 		if ((entry->state & LE_WHITELIST_ADD_TO_CONTROLLER) != 0){
6228 			return ERROR_CODE_COMMAND_DISALLOWED;
6229 		}
6230 		// still on controller, but scheduled to remove -> re-add
6231 		entry->state |= LE_WHITELIST_ADD_TO_CONTROLLER;
6232 		return ERROR_CODE_SUCCESS;
6233     }
6234     // alloc and add to list
6235     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
6236     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
6237     entry->address_type = address_type;
6238     (void)memcpy(entry->address, address, 6);
6239     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
6240     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
6241     return ERROR_CODE_SUCCESS;
6242 }
6243 
6244 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6245     btstack_linked_list_iterator_t it;
6246     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6247     while (btstack_linked_list_iterator_has_next(&it)){
6248         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6249         if (entry->address_type != address_type) {
6250             continue;
6251         }
6252         if (memcmp(entry->address, address, 6) != 0) {
6253             continue;
6254         }
6255         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6256             // remove from controller if already present
6257             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6258         }  else {
6259             // directly remove entry from whitelist
6260             btstack_linked_list_iterator_remove(&it);
6261             btstack_memory_whitelist_entry_free(entry);
6262         }
6263         return ERROR_CODE_SUCCESS;
6264     }
6265     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6266 }
6267 
6268 static void hci_whitelist_clear(void){
6269     btstack_linked_list_iterator_t it;
6270     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6271     while (btstack_linked_list_iterator_has_next(&it)){
6272         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6273         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6274             // remove from controller if already present
6275             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6276             continue;
6277         }
6278         // directly remove entry from whitelist
6279         btstack_linked_list_iterator_remove(&it);
6280         btstack_memory_whitelist_entry_free(entry);
6281     }
6282 }
6283 
6284 // free all entries unconditionally
6285 static void hci_whitelist_free(void){
6286     btstack_linked_list_iterator_t lit;
6287     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
6288     while (btstack_linked_list_iterator_has_next(&lit)){
6289         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
6290         btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
6291         btstack_memory_whitelist_entry_free(entry);
6292     }
6293 }
6294 
6295 /**
6296  * @brief Clear Whitelist
6297  * @return 0 if ok
6298  */
6299 uint8_t gap_whitelist_clear(void){
6300     hci_whitelist_clear();
6301     hci_run();
6302     return ERROR_CODE_SUCCESS;
6303 }
6304 
6305 /**
6306  * @brief Add Device to Whitelist
6307  * @param address_typ
6308  * @param address
6309  * @return 0 if ok
6310  */
6311 uint8_t gap_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6312     uint8_t status = hci_whitelist_add(address_type, address);
6313     if (status){
6314         return status;
6315     }
6316     hci_run();
6317     return ERROR_CODE_SUCCESS;
6318 }
6319 
6320 /**
6321  * @brief Remove Device from Whitelist
6322  * @param address_typ
6323  * @param address
6324  * @return 0 if ok
6325  */
6326 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6327     uint8_t status = hci_whitelist_remove(address_type, address);
6328     if (status){
6329         return status;
6330     }
6331     hci_run();
6332     return ERROR_CODE_SUCCESS;
6333 }
6334 
6335 #ifdef ENABLE_LE_CENTRAL
6336 /**
6337  * @brief Connect with Whitelist
6338  * @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
6339  * @return - if ok
6340  */
6341 uint8_t gap_connect_with_whitelist(void){
6342     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
6343         return ERROR_CODE_COMMAND_DISALLOWED;
6344     }
6345     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6346     hci_run();
6347     return ERROR_CODE_SUCCESS;
6348 }
6349 
6350 /**
6351  * @brief Auto Connection Establishment - Start Connecting to device
6352  * @param address_typ
6353  * @param address
6354  * @return 0 if ok
6355  */
6356 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, const bd_addr_t address){
6357     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6358         return ERROR_CODE_COMMAND_DISALLOWED;
6359     }
6360 
6361     uint8_t status = hci_whitelist_add(address_type, address);
6362     if (status == BTSTACK_MEMORY_ALLOC_FAILED) {
6363         return status;
6364     }
6365 
6366     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6367 
6368     hci_run();
6369     return ERROR_CODE_SUCCESS;
6370 }
6371 
6372 /**
6373  * @brief Auto Connection Establishment - Stop Connecting to device
6374  * @param address_typ
6375  * @param address
6376  * @return 0 if ok
6377  */
6378 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, const bd_addr_t address){
6379     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6380         return ERROR_CODE_COMMAND_DISALLOWED;
6381     }
6382 
6383     hci_whitelist_remove(address_type, address);
6384     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
6385         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6386     }
6387     hci_run();
6388     return 0;
6389 }
6390 
6391 /**
6392  * @brief Auto Connection Establishment - Stop everything
6393  * @note  Convenience function to stop all active auto connection attempts
6394  */
6395 uint8_t gap_auto_connection_stop_all(void){
6396     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
6397         return ERROR_CODE_COMMAND_DISALLOWED;
6398     }
6399     hci_whitelist_clear();
6400     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6401     hci_run();
6402     return ERROR_CODE_SUCCESS;
6403 }
6404 
6405 uint16_t gap_le_connection_interval(hci_con_handle_t con_handle){
6406     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6407     if (!conn) return 0;
6408     return conn->le_connection_interval;
6409 }
6410 #endif
6411 #endif
6412 
6413 #ifdef ENABLE_CLASSIC
6414 /**
6415  * @brief Set Extended Inquiry Response data
6416  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
6417  * @note has to be done before stack starts up
6418  */
6419 void gap_set_extended_inquiry_response(const uint8_t * data){
6420     hci_stack->eir_data = data;
6421     hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
6422     hci_run();
6423 }
6424 
6425 /**
6426  * @brief Start GAP Classic Inquiry
6427  * @param duration in 1.28s units
6428  * @return 0 if ok
6429  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
6430  */
6431 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
6432     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
6433     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6434     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
6435         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
6436     }
6437     hci_stack->inquiry_state = duration_in_1280ms_units;
6438     hci_run();
6439     return 0;
6440 }
6441 
6442 /**
6443  * @brief Stop GAP Classic Inquiry
6444  * @return 0 if ok
6445  */
6446 int gap_inquiry_stop(void){
6447     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
6448         // emit inquiry complete event, before it even started
6449         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
6450         hci_emit_event(event, sizeof(event), 1);
6451         return 0;
6452     }
6453     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
6454     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
6455     hci_run();
6456     return 0;
6457 }
6458 
6459 void gap_inquiry_set_lap(uint32_t lap){
6460     hci_stack->inquiry_lap = lap;
6461 }
6462 
6463 void gap_inquiry_set_scan_activity(uint16_t inquiry_scan_interval, uint16_t inquiry_scan_window){
6464     hci_stack->inquiry_scan_interval = inquiry_scan_interval;
6465     hci_stack->inquiry_scan_window   = inquiry_scan_window;
6466     hci_stack->gap_tasks |= GAP_TASK_WRITE_INQUIRY_SCAN_ACTIVITY;
6467     hci_run();
6468 }
6469 
6470 
6471 /**
6472  * @brief Remote Name Request
6473  * @param addr
6474  * @param page_scan_repetition_mode
6475  * @param clock_offset only used when bit 15 is set
6476  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
6477  */
6478 int gap_remote_name_request(const bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
6479     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6480     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
6481     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
6482     hci_stack->remote_name_clock_offset = clock_offset;
6483     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
6484     hci_run();
6485     return 0;
6486 }
6487 
6488 static int gap_pairing_set_state_and_run(const bd_addr_t addr, uint8_t state){
6489     hci_stack->gap_pairing_state = state;
6490     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
6491     hci_run();
6492     return 0;
6493 }
6494 
6495 /**
6496  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
6497  * @param addr
6498  * @param pin_data
6499  * @param pin_len
6500  * @return 0 if ok
6501  */
6502 int gap_pin_code_response_binary(const bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
6503     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6504     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
6505     hci_stack->gap_pairing_pin_len = pin_len;
6506     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
6507 }
6508 
6509 /**
6510  * @brief Legacy Pairing Pin Code Response
6511  * @param addr
6512  * @param pin
6513  * @return 0 if ok
6514  */
6515 int gap_pin_code_response(const bd_addr_t addr, const char * pin){
6516     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
6517 }
6518 
6519 /**
6520  * @brief Abort Legacy Pairing
6521  * @param addr
6522  * @param pin
6523  * @return 0 if ok
6524  */
6525 int gap_pin_code_negative(bd_addr_t addr){
6526     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6527     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
6528 }
6529 
6530 /**
6531  * @brief SSP Passkey Response
6532  * @param addr
6533  * @param passkey
6534  * @return 0 if ok
6535  */
6536 int gap_ssp_passkey_response(const bd_addr_t addr, uint32_t passkey){
6537     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6538     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
6539     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
6540 }
6541 
6542 /**
6543  * @brief Abort SSP Passkey Entry/Pairing
6544  * @param addr
6545  * @param pin
6546  * @return 0 if ok
6547  */
6548 int gap_ssp_passkey_negative(const bd_addr_t addr){
6549     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6550     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
6551 }
6552 
6553 /**
6554  * @brief Accept SSP Numeric Comparison
6555  * @param addr
6556  * @param passkey
6557  * @return 0 if ok
6558  */
6559 int gap_ssp_confirmation_response(const bd_addr_t addr){
6560     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6561     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
6562 }
6563 
6564 /**
6565  * @brief Abort SSP Numeric Comparison/Pairing
6566  * @param addr
6567  * @param pin
6568  * @return 0 if ok
6569  */
6570 int gap_ssp_confirmation_negative(const bd_addr_t addr){
6571     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6572     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
6573 }
6574 
6575 #if defined(ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY) || defined(ENABLE_EXPLICIT_LINK_KEY_REPLY)
6576 static uint8_t gap_set_auth_flag_and_run(const bd_addr_t addr, hci_authentication_flags_t flag){
6577     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6578     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6579     connectionSetAuthenticationFlags(conn, flag);
6580     hci_run();
6581     return ERROR_CODE_SUCCESS;
6582 }
6583 #endif
6584 
6585 #ifdef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
6586 uint8_t gap_ssp_io_capabilities_response(const bd_addr_t addr){
6587     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
6588 }
6589 
6590 uint8_t gap_ssp_io_capabilities_negative(const bd_addr_t addr){
6591     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
6592 }
6593 #endif
6594 
6595 #ifdef ENABLE_CLASSIC_PAIRING_OOB
6596 /**
6597  * @brief Report Remote OOB Data
6598  * @param bd_addr
6599  * @param c_192 Simple Pairing Hash C derived from P-192 public key
6600  * @param r_192 Simple Pairing Randomizer derived from P-192 public key
6601  * @param c_256 Simple Pairing Hash C derived from P-256 public key
6602  * @param r_256 Simple Pairing Randomizer derived from P-256 public key
6603  */
6604 uint8_t gap_ssp_remote_oob_data(const bd_addr_t addr, const uint8_t * c_192, const uint8_t * r_192, const uint8_t * c_256, const uint8_t * r_256){
6605     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6606     if (connection == NULL) {
6607         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6608     }
6609     connection->classic_oob_c_192 = c_192;
6610     connection->classic_oob_r_192 = r_192;
6611 
6612     // ignore P-256 if not supported by us
6613     if (hci_stack->secure_connections_active){
6614         connection->classic_oob_c_256 = c_256;
6615         connection->classic_oob_r_256 = r_256;
6616     }
6617 
6618     return ERROR_CODE_SUCCESS;
6619 }
6620 /**
6621  * @brief Generate new OOB data
6622  * @note OOB data will be provided in GAP_EVENT_LOCAL_OOB_DATA and be used in future pairing procedures
6623  */
6624 void gap_ssp_generate_oob_data(void){
6625     hci_stack->classic_read_local_oob_data = true;
6626     hci_run();
6627 }
6628 
6629 #endif
6630 
6631 #ifdef ENABLE_EXPLICIT_LINK_KEY_REPLY
6632 uint8_t gap_send_link_key_response(const bd_addr_t addr, link_key_t link_key, link_key_type_t type){
6633     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6634     if (connection == NULL) {
6635         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6636     }
6637 
6638     memcpy(connection->link_key, link_key, sizeof(link_key_t));
6639     connection->link_key_type = type;
6640 
6641     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
6642 }
6643 
6644 #endif // ENABLE_EXPLICIT_LINK_KEY_REPLY
6645 /**
6646  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
6647  * @param inquiry_mode see bluetooth_defines.h
6648  */
6649 void hci_set_inquiry_mode(inquiry_mode_t inquiry_mode){
6650     hci_stack->inquiry_mode = inquiry_mode;
6651 }
6652 
6653 /**
6654  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
6655  */
6656 void hci_set_sco_voice_setting(uint16_t voice_setting){
6657     hci_stack->sco_voice_setting = voice_setting;
6658 }
6659 
6660 /**
6661  * @brief Get SCO Voice Setting
6662  * @return current voice setting
6663  */
6664 uint16_t hci_get_sco_voice_setting(void){
6665     return hci_stack->sco_voice_setting;
6666 }
6667 
6668 static int hci_have_usb_transport(void){
6669     if (!hci_stack->hci_transport) return 0;
6670     const char * transport_name = hci_stack->hci_transport->name;
6671     if (!transport_name) return 0;
6672     return (transport_name[0] == 'H') && (transport_name[1] == '2');
6673 }
6674 
6675 /** @brief Get SCO packet length for current SCO Voice setting
6676  *  @note  Using SCO packets of the exact length is required for USB transfer
6677  *  @return Length of SCO packets in bytes (not audio frames)
6678  */
6679 uint16_t hci_get_sco_packet_length(void){
6680     uint16_t sco_packet_length = 0;
6681 
6682 #ifdef ENABLE_SCO_OVER_HCI
6683     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6684     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6685 
6686     if (hci_have_usb_transport()){
6687         // see Core Spec for H2 USB Transfer.
6688         // 3 byte SCO header + 24 bytes per connection
6689         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
6690         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
6691     } else {
6692         // 3 byte SCO header + SCO packet size over the air (60 bytes)
6693         sco_packet_length = 3 + 60 * multiplier;
6694         // assert that it still fits inside an SCO buffer
6695         if (sco_packet_length > hci_stack->sco_data_packet_length){
6696             sco_packet_length = 3 + 60;
6697         }
6698     }
6699 #endif
6700 
6701 #ifdef HAVE_SCO_TRANSPORT
6702     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6703     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6704     sco_packet_length = 3 + 60 * multiplier;
6705 #endif
6706     return sco_packet_length;
6707 }
6708 
6709 /**
6710 * @brief Sets the master/slave policy
6711 * @param policy (0: attempt to become master, 1: let connecting device decide)
6712 */
6713 void hci_set_master_slave_policy(uint8_t policy){
6714     hci_stack->master_slave_policy = policy;
6715 }
6716 
6717 #endif
6718 
6719 HCI_STATE hci_get_state(void){
6720     return hci_stack->state;
6721 }
6722 
6723 #ifdef ENABLE_CLASSIC
6724 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr, hci_link_type_t link_type)){
6725     hci_stack->gap_classic_accept_callback = accept_callback;
6726 }
6727 #endif
6728 
6729 /**
6730  * @brief Set callback for Bluetooth Hardware Error
6731  */
6732 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
6733     hci_stack->hardware_error_callback = fn;
6734 }
6735 
6736 void hci_disconnect_all(void){
6737     btstack_linked_list_iterator_t it;
6738     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6739     while (btstack_linked_list_iterator_has_next(&it)){
6740         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6741         if (con->state == SENT_DISCONNECT) continue;
6742         con->state = SEND_DISCONNECT;
6743     }
6744     hci_run();
6745 }
6746 
6747 uint16_t hci_get_manufacturer(void){
6748     return hci_stack->manufacturer;
6749 }
6750 
6751 #ifdef ENABLE_BLE
6752 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
6753     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
6754     if (!hci_con) return NULL;
6755     return &hci_con->sm_connection;
6756 }
6757 
6758 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
6759 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
6760 #endif
6761 
6762 int gap_encryption_key_size(hci_con_handle_t con_handle){
6763     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6764     if (hci_connection == NULL) return 0;
6765     if (hci_is_le_connection(hci_connection)){
6766 #ifdef ENABLE_BLE
6767         sm_connection_t * sm_conn = &hci_connection->sm_connection;
6768         if (sm_conn->sm_connection_encrypted) {
6769             return sm_conn->sm_actual_encryption_key_size;
6770         }
6771 #endif
6772     } else {
6773 #ifdef ENABLE_CLASSIC
6774         if ((hci_connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED)){
6775             return hci_connection->encryption_key_size;
6776         }
6777 #endif
6778     }
6779     return 0;
6780 }
6781 
6782 int gap_authenticated(hci_con_handle_t con_handle){
6783     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6784     if (hci_connection == NULL) return 0;
6785 
6786     switch (hci_connection->address_type){
6787 #ifdef ENABLE_BLE
6788         case BD_ADDR_TYPE_LE_PUBLIC:
6789         case BD_ADDR_TYPE_LE_RANDOM:
6790             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6791             return hci_connection->sm_connection.sm_connection_authenticated;
6792 #endif
6793 #ifdef ENABLE_CLASSIC
6794         case BD_ADDR_TYPE_SCO:
6795         case BD_ADDR_TYPE_ACL:
6796             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
6797 #endif
6798         default:
6799             return 0;
6800     }
6801 }
6802 
6803 int gap_secure_connection(hci_con_handle_t con_handle){
6804     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6805     if (hci_connection == NULL) return 0;
6806 
6807     switch (hci_connection->address_type){
6808 #ifdef ENABLE_BLE
6809         case BD_ADDR_TYPE_LE_PUBLIC:
6810         case BD_ADDR_TYPE_LE_RANDOM:
6811             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6812             return hci_connection->sm_connection.sm_connection_sc;
6813 #endif
6814 #ifdef ENABLE_CLASSIC
6815         case BD_ADDR_TYPE_SCO:
6816         case BD_ADDR_TYPE_ACL:
6817             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
6818 #endif
6819         default:
6820             return 0;
6821     }
6822 }
6823 
6824 bool gap_bonded(hci_con_handle_t con_handle){
6825 	hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6826 	if (hci_connection == NULL) return 0;
6827 
6828 #ifdef ENABLE_CLASSIC
6829 	link_key_t link_key;
6830 	link_key_type_t link_key_type;
6831 #endif
6832 	switch (hci_connection->address_type){
6833 #ifdef ENABLE_BLE
6834 		case BD_ADDR_TYPE_LE_PUBLIC:
6835 		case BD_ADDR_TYPE_LE_RANDOM:
6836 			return hci_connection->sm_connection.sm_le_db_index >= 0;
6837 #endif
6838 #ifdef ENABLE_CLASSIC
6839 		case BD_ADDR_TYPE_SCO:
6840 		case BD_ADDR_TYPE_ACL:
6841 			return hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(hci_connection->address, link_key, &link_key_type);
6842 #endif
6843 		default:
6844 			return false;
6845 	}
6846 }
6847 
6848 #ifdef ENABLE_BLE
6849 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
6850     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
6851     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
6852     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
6853     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
6854     return sm_conn->sm_connection_authorization_state;
6855 }
6856 #endif
6857 
6858 #ifdef ENABLE_CLASSIC
6859 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){
6860     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6861     if (!conn) return GAP_CONNECTION_INVALID;
6862     conn->sniff_min_interval = sniff_min_interval;
6863     conn->sniff_max_interval = sniff_max_interval;
6864     conn->sniff_attempt = sniff_attempt;
6865     conn->sniff_timeout = sniff_timeout;
6866     hci_run();
6867     return 0;
6868 }
6869 
6870 /**
6871  * @brief Exit Sniff mode
6872  * @param con_handle
6873  @ @return 0 if ok
6874  */
6875 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
6876     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6877     if (!conn) return GAP_CONNECTION_INVALID;
6878     conn->sniff_min_interval = 0xffff;
6879     hci_run();
6880     return 0;
6881 }
6882 
6883 uint8_t gap_sniff_subrating_configure(hci_con_handle_t con_handle, uint16_t max_latency, uint16_t min_remote_timeout, uint16_t min_local_timeout){
6884     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6885     if (!conn) return GAP_CONNECTION_INVALID;
6886     conn->sniff_subrating_max_latency = max_latency;
6887     conn->sniff_subrating_min_remote_timeout = min_remote_timeout;
6888     conn->sniff_subrating_min_local_timeout = min_local_timeout;
6889     hci_run();
6890     return ERROR_CODE_SUCCESS;
6891 }
6892 
6893 uint8_t gap_qos_set(hci_con_handle_t con_handle, hci_service_type_t service_type, uint32_t token_rate, uint32_t peak_bandwidth, uint32_t latency, uint32_t delay_variation){
6894     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6895     if (!conn) return GAP_CONNECTION_INVALID;
6896     conn->qos_service_type = service_type;
6897     conn->qos_token_rate = token_rate;
6898     conn->qos_peak_bandwidth = peak_bandwidth;
6899     conn->qos_latency = latency;
6900     conn->qos_delay_variation = delay_variation;
6901     hci_run();
6902     return ERROR_CODE_SUCCESS;
6903 }
6904 
6905 void gap_set_page_scan_activity(uint16_t page_scan_interval, uint16_t page_scan_window){
6906     hci_stack->new_page_scan_interval = page_scan_interval;
6907     hci_stack->new_page_scan_window = page_scan_window;
6908     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
6909     hci_run();
6910 }
6911 
6912 void gap_set_page_scan_type(page_scan_type_t page_scan_type){
6913     hci_stack->new_page_scan_type = (uint8_t) page_scan_type;
6914     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_TYPE;
6915     hci_run();
6916 }
6917 
6918 void gap_set_page_timeout(uint16_t page_timeout){
6919     hci_stack->page_timeout = page_timeout;
6920     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_TIMEOUT;
6921     hci_run();
6922 }
6923 
6924 #endif
6925 
6926 void hci_halting_defer(void){
6927     if (hci_stack->state != HCI_STATE_HALTING) return;
6928     switch (hci_stack->substate){
6929         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
6930         case HCI_HALTING_CLOSE:
6931             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
6932             break;
6933         default:
6934             break;
6935     }
6936 }
6937 
6938 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
6939 void hci_load_le_device_db_entry_into_resolving_list(uint16_t le_device_db_index){
6940     if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6941     if (le_device_db_index >= le_device_db_max_count()) return;
6942     uint8_t offset = le_device_db_index >> 3;
6943     uint8_t mask = 1 << (le_device_db_index & 7);
6944     hci_stack->le_resolving_list_add_entries[offset] |= mask;
6945     if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6946     	// note: go back to remove entries, otherwise, a remove + add will skip the add
6947         hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6948     }
6949 }
6950 
6951 void hci_remove_le_device_db_entry_from_resolving_list(uint16_t le_device_db_index){
6952 	if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6953 	if (le_device_db_index >= le_device_db_max_count()) return;
6954 	uint8_t offset = le_device_db_index >> 3;
6955 	uint8_t mask = 1 << (le_device_db_index & 7);
6956 	hci_stack->le_resolving_list_remove_entries[offset] |= mask;
6957 	if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6958 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6959 	}
6960 }
6961 
6962 uint8_t gap_load_resolving_list_from_le_device_db(void){
6963 	if ((hci_stack->local_supported_commands[1] & (1 << 2)) == 0) {
6964 		return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
6965 	}
6966 	if (hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION){
6967 		// restart le resolving list update
6968 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
6969 	}
6970 	return ERROR_CODE_SUCCESS;
6971 }
6972 #endif
6973 
6974 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
6975 void hci_setup_test_connections_fuzz(void){
6976     hci_connection_t * conn;
6977 
6978     // default address: 66:55:44:33:00:01
6979     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
6980 
6981     // setup Controller info
6982     hci_stack->num_cmd_packets = 255;
6983     hci_stack->acl_packets_total_num = 255;
6984 
6985     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
6986     addr[5] = 0x01;
6987     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6988     conn->con_handle = addr[5];
6989     conn->role  = HCI_ROLE_SLAVE;
6990     conn->state = RECEIVED_CONNECTION_REQUEST;
6991     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6992 
6993     // setup incoming Classic SCO connection with con handle 0x0002
6994     addr[5] = 0x02;
6995     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6996     conn->con_handle = addr[5];
6997     conn->role  = HCI_ROLE_SLAVE;
6998     conn->state = RECEIVED_CONNECTION_REQUEST;
6999     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
7000 
7001     // setup ready Classic ACL connection with con handle 0x0003
7002     addr[5] = 0x03;
7003     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
7004     conn->con_handle = addr[5];
7005     conn->role  = HCI_ROLE_SLAVE;
7006     conn->state = OPEN;
7007     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
7008 
7009     // setup ready Classic SCO connection with con handle 0x0004
7010     addr[5] = 0x04;
7011     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
7012     conn->con_handle = addr[5];
7013     conn->role  = HCI_ROLE_SLAVE;
7014     conn->state = OPEN;
7015     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
7016 
7017     // setup ready LE ACL connection with con handle 0x005 and public address
7018     addr[5] = 0x05;
7019     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
7020     conn->con_handle = addr[5];
7021     conn->role  = HCI_ROLE_SLAVE;
7022     conn->state = OPEN;
7023     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
7024     conn->sm_connection.sm_connection_encrypted = 1;
7025 }
7026 
7027 void hci_free_connections_fuzz(void){
7028     btstack_linked_list_iterator_t it;
7029     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
7030     while (btstack_linked_list_iterator_has_next(&it)){
7031         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
7032         btstack_linked_list_iterator_remove(&it);
7033         btstack_memory_hci_connection_free(con);
7034     }
7035 }
7036 void hci_simulate_working_fuzz(void){
7037     hci_init_done();
7038     hci_stack->num_cmd_packets = 255;
7039 }
7040 #endif
7041