xref: /btstack/src/hci.c (revision 83dc1a98635e0897f3bc004d9d1e08586d1e2649)
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_emit_transport_packet_sent(void);
156 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
157 static void hci_emit_nr_connections_changed(void);
158 static void hci_emit_hci_open_failed(void);
159 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
160 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
161 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
162 static void hci_run(void);
163 static int  hci_is_le_connection(hci_connection_t * connection);
164 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
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 static int 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 free_slots_classic;
591 
592         default:
593            if (hci_stack->le_acl_packets_total_num){
594                return free_slots_le;
595            }
596            return 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 static int gap_ssp_supported(void){
1146     // No. 51, byte 6, bit 3
1147     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1148 }
1149 
1150 static int hci_classic_supported(void){
1151 #ifdef ENABLE_CLASSIC
1152     // No. 37, byte 4, bit 5, = No BR/EDR Support
1153     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1154 #else
1155     return 0;
1156 #endif
1157 }
1158 
1159 static int hci_le_supported(void){
1160 #ifdef ENABLE_BLE
1161     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1162     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1163 #else
1164     return 0;
1165 #endif
1166 }
1167 
1168 #ifdef ENABLE_BLE
1169 
1170 static void hci_get_own_address_for_addr_type(uint8_t own_addr_type, bd_addr_t own_addr){
1171     if (own_addr_type == BD_ADDR_TYPE_LE_PUBLIC){
1172         (void)memcpy(own_addr, hci_stack->local_bd_addr, 6);
1173     } else {
1174         (void)memcpy(own_addr, hci_stack->le_random_address, 6);
1175     }
1176 }
1177 
1178 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1179     *addr_type = hci_stack->le_own_addr_type;
1180     hci_get_own_address_for_addr_type(hci_stack->le_own_addr_type, addr);
1181 }
1182 
1183 #ifdef ENABLE_LE_PERIPHERAL
1184 void gap_le_get_own_advertisements_address(uint8_t * addr_type, bd_addr_t addr){
1185     *addr_type = hci_stack->le_advertisements_own_addr_type;
1186     hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, addr);
1187 };
1188 #endif
1189 
1190 #ifdef ENABLE_LE_CENTRAL
1191 
1192 /**
1193  * @brief Get own addr type and address used for LE connections (Central)
1194  */
1195 void gap_le_get_own_connection_address(uint8_t * addr_type, bd_addr_t addr){
1196     *addr_type = hci_stack->le_connection_own_addr_type;
1197     hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, addr);
1198 }
1199 
1200 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1201 
1202     int offset = 3;
1203     int num_reports = packet[offset];
1204     offset += 1;
1205 
1206     int i;
1207     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1208     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1209     for (i=0; (i<num_reports) && (offset < size);i++){
1210         // sanity checks on data_length:
1211         uint8_t data_length = packet[offset + 8];
1212         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1213         if ((offset + 9u + data_length + 1u) > size)    return;
1214         // setup event
1215         uint8_t event_size = 10u + data_length;
1216         int pos = 0;
1217         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1218         event[pos++] = event_size;
1219         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1220         offset += 8;
1221         pos += 8;
1222         event[pos++] = packet[offset + 1 + data_length]; // rssi
1223         event[pos++] = data_length;
1224         offset++;
1225         (void)memcpy(&event[pos], &packet[offset], data_length);
1226         pos +=    data_length;
1227         offset += data_length + 1u; // rssi
1228         hci_emit_event(event, pos, 1);
1229     }
1230 }
1231 #endif
1232 #endif
1233 
1234 #ifdef ENABLE_BLE
1235 #ifdef ENABLE_LE_PERIPHERAL
1236 static void hci_update_advertisements_enabled_for_current_roles(void){
1237     if (hci_stack->le_advertisements_enabled){
1238         // get number of active le slave connections
1239         int num_slave_connections = 0;
1240         btstack_linked_list_iterator_t it;
1241         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1242         while (btstack_linked_list_iterator_has_next(&it)){
1243             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1244             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1245             if (con->state != OPEN) continue;
1246             if (con->role  != HCI_ROLE_SLAVE) continue;
1247             if (!hci_is_le_connection(con)) continue;
1248             num_slave_connections++;
1249         }
1250         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1251         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1252     } else {
1253         hci_stack->le_advertisements_enabled_for_current_roles = false;
1254     }
1255 }
1256 #endif
1257 #endif
1258 
1259 #ifdef ENABLE_CLASSIC
1260 static void gap_run_set_local_name(void){
1261     hci_reserve_packet_buffer();
1262     uint8_t * packet = hci_stack->hci_packet_buffer;
1263     // construct HCI Command and send
1264     uint16_t opcode = hci_write_local_name.opcode;
1265     hci_stack->last_cmd_opcode = opcode;
1266     packet[0] = opcode & 0xff;
1267     packet[1] = opcode >> 8;
1268     packet[2] = DEVICE_NAME_LEN;
1269     memset(&packet[3], 0, DEVICE_NAME_LEN);
1270     uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1271     uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1272     // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1273     (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1274     // expand '00:00:00:00:00:00' in name with bd_addr
1275     btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1276     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1277 }
1278 
1279 static void gap_run_set_eir_data(void){
1280     hci_reserve_packet_buffer();
1281     uint8_t * packet = hci_stack->hci_packet_buffer;
1282     // construct HCI Command in-place and send
1283     uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1284     hci_stack->last_cmd_opcode = opcode;
1285     uint16_t offset = 0;
1286     packet[offset++] = opcode & 0xff;
1287     packet[offset++] = opcode >> 8;
1288     packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1289     packet[offset++] = 0;  // FEC not required
1290     memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1291     if (hci_stack->eir_data){
1292         // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1293         ad_context_t context;
1294         for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1295             uint8_t data_type   = ad_iterator_get_data_type(&context);
1296             uint8_t size        = ad_iterator_get_data_len(&context);
1297             const uint8_t *data = ad_iterator_get_data(&context);
1298             // copy item
1299             packet[offset++] = size + 1;
1300             packet[offset++] = data_type;
1301             memcpy(&packet[offset], data, size);
1302             // update name item
1303             if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1304                 btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1305             }
1306             offset += size;
1307         }
1308     } else {
1309         uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1310         uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1311         packet[offset++] = bytes_to_copy + 1;
1312         packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1313         (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1314         // expand '00:00:00:00:00:00' in name with bd_addr
1315         btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1316     }
1317     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1318 }
1319 
1320 static void hci_run_gap_tasks_classic(void){
1321     if ((hci_stack->gap_tasks & GAP_TASK_SET_CLASS_OF_DEVICE) != 0) {
1322         hci_stack->gap_tasks &= ~GAP_TASK_SET_CLASS_OF_DEVICE;
1323         hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1324         return;
1325     }
1326     if ((hci_stack->gap_tasks & GAP_TASK_SET_LOCAL_NAME) != 0) {
1327         hci_stack->gap_tasks &= ~GAP_TASK_SET_LOCAL_NAME;
1328         gap_run_set_local_name();
1329         return;
1330     }
1331     if ((hci_stack->gap_tasks & GAP_TASK_SET_EIR_DATA) != 0) {
1332         hci_stack->gap_tasks &= ~GAP_TASK_SET_EIR_DATA;
1333         gap_run_set_eir_data();
1334         return;
1335     }
1336     if ((hci_stack->gap_tasks & GAP_TASK_SET_DEFAULT_LINK_POLICY) != 0) {
1337         hci_stack->gap_tasks &= ~GAP_TASK_SET_DEFAULT_LINK_POLICY;
1338         hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1339         return;
1340     }
1341     // write page scan activity
1342     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY) != 0) {
1343         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
1344         hci_send_cmd(&hci_write_page_scan_activity, hci_stack->new_page_scan_interval, hci_stack->new_page_scan_window);
1345         return;
1346     }
1347     // write page scan type
1348     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_TYPE) != 0) {
1349         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_TYPE;
1350         hci_send_cmd(&hci_write_page_scan_type, hci_stack->new_page_scan_type);
1351         return;
1352     }
1353     // write page timeout
1354     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_TIMEOUT) != 0) {
1355         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_TIMEOUT;
1356         hci_send_cmd(&hci_write_page_timeout, hci_stack->page_timeout);
1357         return;
1358     }
1359     // send scan enable
1360     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_SCAN_ENABLE) != 0) {
1361         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_SCAN_ENABLE;
1362         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1363         return;
1364     }
1365     // send write scan activity
1366     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_INQUIRY_SCAN_ACTIVITY) != 0) {
1367         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_INQUIRY_SCAN_ACTIVITY;
1368         hci_send_cmd(&hci_write_inquiry_scan_activity, hci_stack->inquiry_scan_interval, hci_stack->inquiry_scan_window);
1369         return;
1370     }
1371 }
1372 #endif
1373 
1374 #ifndef HAVE_HOST_CONTROLLER_API
1375 
1376 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1377     if (!hci_stack->config) return 0;
1378     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1379     // Limit baud rate for Broadcom chipsets to 3 mbps
1380     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1381         baud_rate = 3000000;
1382     }
1383     return baud_rate;
1384 }
1385 
1386 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1387     UNUSED(ds);
1388 
1389     switch (hci_stack->substate){
1390         case HCI_INIT_W4_SEND_RESET:
1391             log_info("Resend HCI Reset");
1392             hci_stack->substate = HCI_INIT_SEND_RESET;
1393             hci_stack->num_cmd_packets = 1;
1394             hci_run();
1395             break;
1396         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1397             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1398             if (hci_stack->hci_transport->reset_link){
1399                 hci_stack->hci_transport->reset_link();
1400             }
1401 
1402             /* fall through */
1403 
1404         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1405             log_info("Resend HCI Reset - CSR Warm Boot");
1406             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1407             hci_stack->num_cmd_packets = 1;
1408             hci_run();
1409             break;
1410         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1411             if (hci_stack->hci_transport->set_baudrate){
1412                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1413                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1414                 hci_stack->hci_transport->set_baudrate(baud_rate);
1415             }
1416             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1417             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1418                 if (hci_stack->hci_transport->reset_link){
1419                     log_info("Link Reset");
1420                     hci_stack->hci_transport->reset_link();
1421                 }
1422                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1423                 hci_run();
1424             }
1425             break;
1426         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1427             // otherwise continue
1428             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1429             hci_send_cmd(&hci_read_local_supported_commands);
1430             break;
1431         default:
1432             break;
1433     }
1434 }
1435 #endif
1436 
1437 static void hci_initializing_next_state(void){
1438     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1439 }
1440 
1441 static void hci_init_done(void){
1442     // done. tell the app
1443     log_info("hci_init_done -> HCI_STATE_WORKING");
1444     hci_stack->state = HCI_STATE_WORKING;
1445     hci_emit_state();
1446 }
1447 
1448 // assumption: hci_can_send_command_packet_now() == true
1449 static void hci_initializing_run(void){
1450     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1451 
1452 #ifndef HAVE_HOST_CONTROLLER_API
1453     bool need_baud_change = hci_stack->config
1454             && hci_stack->chipset
1455             && hci_stack->chipset->set_baudrate_command
1456             && hci_stack->hci_transport->set_baudrate
1457             && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1458 #endif
1459 
1460     switch (hci_stack->substate){
1461         case HCI_INIT_SEND_RESET:
1462             hci_state_reset();
1463 
1464 #ifndef HAVE_HOST_CONTROLLER_API
1465             // prepare reset if command complete not received in 100ms
1466             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1467             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1468             btstack_run_loop_add_timer(&hci_stack->timeout);
1469 #endif
1470             // send command
1471             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1472             hci_send_cmd(&hci_reset);
1473             break;
1474         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1475             hci_send_cmd(&hci_read_local_version_information);
1476             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1477             break;
1478 
1479 #ifndef HAVE_HOST_CONTROLLER_API
1480         case HCI_INIT_SEND_READ_LOCAL_NAME:
1481             hci_send_cmd(&hci_read_local_name);
1482             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1483             break;
1484         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1485             hci_state_reset();
1486             // prepare reset if command complete not received in 100ms
1487             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1488             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1489             btstack_run_loop_add_timer(&hci_stack->timeout);
1490             // send command
1491             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1492             hci_send_cmd(&hci_reset);
1493             break;
1494         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1495             hci_state_reset();
1496             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1497             hci_send_cmd(&hci_reset);
1498             break;
1499         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1500             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1501             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1502             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1503             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1504             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1505             break;
1506         }
1507         case HCI_INIT_SET_BD_ADDR:
1508             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1509             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1510             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1511             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1512             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1513             break;
1514         case HCI_INIT_SEND_BAUD_CHANGE:
1515             if (need_baud_change) {
1516                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1517                 hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1518                 hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1519                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1520                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1521                 // STLC25000D: baudrate change happens within 0.5 s after command was send,
1522                 // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1523                 if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1524                     btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1525                     btstack_run_loop_add_timer(&hci_stack->timeout);
1526                }
1527                break;
1528             }
1529 
1530             /* fall through */
1531 
1532         case HCI_INIT_CUSTOM_INIT:
1533             // Custom initialization
1534             if (hci_stack->chipset && hci_stack->chipset->next_command){
1535                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1536                 bool send_cmd = false;
1537                 switch (hci_stack->chipset_result){
1538                     case BTSTACK_CHIPSET_VALID_COMMAND:
1539                         send_cmd = true;
1540                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1541                         break;
1542                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1543                         send_cmd = true;
1544                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1545                         log_info("CSR Warm Boot");
1546                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1547                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1548                         btstack_run_loop_add_timer(&hci_stack->timeout);
1549                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1550                             && hci_stack->config
1551                             && hci_stack->chipset
1552                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1553                             && hci_stack->hci_transport->set_baudrate
1554                             && hci_transport_uart_get_main_baud_rate()){
1555                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1556                         } else {
1557                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1558                         }
1559                         break;
1560                     default:
1561                         break;
1562                 }
1563 
1564                 if (send_cmd){
1565                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1566                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1567                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1568                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1569                     break;
1570                 }
1571                 log_info("Init script done");
1572 
1573                 // Init script download on Broadcom chipsets causes:
1574                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1575                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1576                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1577 
1578                     // - baud rate to reset, restore UART baud rate if needed
1579                     if (need_baud_change) {
1580                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1581                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1582                         hci_stack->hci_transport->set_baudrate(baud_rate);
1583                     }
1584 
1585                     uint16_t bcm_delay_ms = 300;
1586                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1587                     //   -> Work around: wait here.
1588                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1589                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1590                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1591                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1592                     btstack_run_loop_add_timer(&hci_stack->timeout);
1593                     break;
1594                 }
1595             }
1596 #endif
1597             /* fall through */
1598 
1599         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1600             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1601             hci_send_cmd(&hci_read_local_supported_commands);
1602             break;
1603         case HCI_INIT_READ_BD_ADDR:
1604             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1605             hci_send_cmd(&hci_read_bd_addr);
1606             break;
1607         case HCI_INIT_READ_BUFFER_SIZE:
1608             // only read buffer size if supported
1609             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1610                 hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1611                 hci_send_cmd(&hci_read_buffer_size);
1612                 break;
1613             }
1614 
1615             /* fall through */
1616 
1617         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1618             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1619             hci_send_cmd(&hci_read_local_supported_features);
1620             break;
1621 
1622 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1623         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1624             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1625             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1626             break;
1627         case HCI_INIT_HOST_BUFFER_SIZE:
1628             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1629             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1630                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1631             break;
1632 #endif
1633 
1634         case HCI_INIT_SET_EVENT_MASK:
1635             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1636             if (hci_le_supported()){
1637                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x3FFFFFFFU);
1638             } else {
1639                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1640                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x1FFFFFFFU);
1641             }
1642             break;
1643 
1644 #ifdef ENABLE_CLASSIC
1645         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1646             if (hci_classic_supported() && gap_ssp_supported()){
1647                 hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1648                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1649                 break;
1650             }
1651 
1652             /* fall through */
1653 
1654         case HCI_INIT_WRITE_INQUIRY_MODE:
1655             if (hci_classic_supported()){
1656                 hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1657                 hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1658                 break;
1659             }
1660 
1661             /* fall through */
1662 
1663         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1664             // skip write secure connections host support if not supported or disabled
1665             if (hci_classic_supported() && hci_stack->secure_connections_enable && (hci_stack->local_supported_commands[1u] & 0x02u) != 0u) {
1666                 hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1667                 hci_stack->secure_connections_active = true;
1668                 hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1669                 break;
1670             }
1671 
1672 #ifdef ENABLE_SCO_OVER_HCI
1673             /* fall through */
1674 
1675         // only sent if ENABLE_SCO_OVER_HCI is defined
1676         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1677             // skip write synchronous flow control if not supported
1678             if (hci_classic_supported() && ((hci_stack->local_supported_commands[0] & 0x04) != 0)){
1679                 hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1680                 hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1681                 break;
1682             }
1683             /* fall through */
1684 
1685         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1686             // skip write default erroneous data reporting if not supported
1687             if (hci_classic_supported() && ((hci_stack->local_supported_commands[0] & 0x08) != 0)){
1688                 hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1689                 hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1690                 break;
1691             }
1692 #endif
1693 
1694 #if defined(ENABLE_SCO_OVER_HCI) || defined(ENABLE_SCO_OVER_PCM)
1695             /* fall through */
1696 
1697         // only sent if manufacturer is Broadcom and ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM is defined
1698         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1699             if (hci_classic_supported() && (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)){
1700                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1701 #ifdef ENABLE_SCO_OVER_HCI
1702                 log_info("BCM: Route SCO data via HCI transport");
1703                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1704 #endif
1705 #ifdef ENABLE_SCO_OVER_PCM
1706                 log_info("BCM: Route SCO data via PCM interface");
1707 #ifdef ENABLE_BCM_PCM_WBS
1708                 // 512 kHz bit clock for 2 channels x 16 bit x 16 kHz
1709                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 2, 0, 1, 1);
1710 #else
1711                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1712                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 1, 0, 1, 1);
1713 #endif
1714 #endif
1715                 break;
1716             }
1717 #endif
1718 
1719 #ifdef ENABLE_SCO_OVER_PCM
1720             /* fall through */
1721 
1722         case HCI_INIT_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
1723             if (hci_classic_supported() && (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)){
1724                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1725                 log_info("BCM: Config PCM interface for I2S");
1726 #ifdef ENABLE_BCM_PCM_WBS
1727                 // 512 kHz bit clock for 2 channels x 16 bit x 8 kHz
1728                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 2);
1729 #else
1730                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1731                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 1);
1732 #endif
1733                 break;
1734             }
1735 #endif
1736 #endif
1737 
1738 #ifdef ENABLE_BLE
1739             /* fall through */
1740 
1741         // LE INIT
1742         case HCI_INIT_LE_READ_BUFFER_SIZE:
1743             if (hci_le_supported()){
1744                 hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1745                 hci_send_cmd(&hci_le_read_buffer_size);
1746                 break;
1747             }
1748 
1749             /* fall through */
1750 
1751         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1752             // skip write le host if not supported (e.g. on LE only EM9301)
1753             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x02u) != 0)){
1754                 // LE Supported Host = 1, Simultaneous Host = 0
1755                 hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1756                 hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1757                 break;
1758             }
1759 
1760             /* fall through */
1761 
1762         case HCI_INIT_LE_SET_EVENT_MASK:
1763             if (hci_le_supported()){
1764                 hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1765                 hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1766                 break;
1767             }
1768 #endif
1769 
1770 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1771             /* fall through */
1772 
1773         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1774             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u)){
1775                 hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1776                 hci_send_cmd(&hci_le_read_maximum_data_length);
1777                 break;
1778             }
1779 
1780             /* fall through */
1781 
1782         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1783             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u)){
1784                 hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1785                 hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1786                 break;
1787             }
1788 #endif
1789 
1790 #ifdef ENABLE_LE_CENTRAL
1791             /* fall through */
1792 
1793         case HCI_INIT_READ_WHITE_LIST_SIZE:
1794             if (hci_le_supported()){
1795                 hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1796                 hci_send_cmd(&hci_le_read_white_list_size);
1797                 break;
1798             }
1799 
1800             /* fall through */
1801 
1802         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1803             if (hci_le_supported()){
1804                 hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1805                 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);
1806                 break;
1807             }
1808 #endif
1809 
1810             /* fall through */
1811 
1812         case HCI_INIT_DONE:
1813             hci_stack->substate = HCI_INIT_DONE;
1814 #ifdef ENABLE_CLASSIC
1815             // init sequence complete, check if GAP Tasks are completed
1816             if (hci_stack->gap_tasks != 0) {
1817                 hci_run_gap_tasks_classic();
1818                 break;
1819             }
1820 #endif
1821             hci_init_done();
1822             break;
1823 
1824         default:
1825             return;
1826     }
1827 }
1828 
1829 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1830     bool command_completed = false;
1831     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1832         uint16_t opcode = little_endian_read_16(packet,3);
1833         if (opcode == hci_stack->last_cmd_opcode){
1834             command_completed = true;
1835             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1836         } else {
1837             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1838         }
1839     }
1840 
1841     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1842         uint8_t  status = packet[2];
1843         uint16_t opcode = little_endian_read_16(packet,4);
1844         if (opcode == hci_stack->last_cmd_opcode){
1845             if (status){
1846                 command_completed = true;
1847                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1848             } else {
1849                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1850             }
1851         } else {
1852             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1853         }
1854     }
1855 #ifndef HAVE_HOST_CONTROLLER_API
1856     // Vendor == CSR
1857     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1858         // TODO: track actual command
1859         command_completed = true;
1860     }
1861 
1862     // Vendor == Toshiba
1863     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1864         // TODO: track actual command
1865         command_completed = true;
1866         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1867         hci_stack->num_cmd_packets = 1;
1868     }
1869 #endif
1870 
1871     return command_completed;
1872 }
1873 
1874 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1875 
1876     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1877 
1878     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1879 
1880 #ifndef HAVE_HOST_CONTROLLER_API
1881 
1882     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1883     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1884     //
1885     // HCI Reset
1886     // Timeout 100 ms
1887     // HCI Reset
1888     // Command Complete Reset
1889     // HCI Read Local Version Information
1890     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1891     // hang...
1892     //
1893     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1894     if (!command_completed
1895             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1896             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1897 
1898         uint16_t opcode = little_endian_read_16(packet,3);
1899         if (opcode == hci_reset.opcode){
1900             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1901             return;
1902         }
1903     }
1904 
1905     // CSR & H5
1906     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1907     if (!command_completed
1908             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1909             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1910 
1911         uint16_t opcode = little_endian_read_16(packet,3);
1912         if (opcode == hci_reset.opcode){
1913             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1914             return;
1915         }
1916     }
1917 
1918     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1919     // fix: Correct substate and behave as command below
1920     if (command_completed){
1921         switch (hci_stack->substate){
1922             case HCI_INIT_SEND_RESET:
1923                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1924                 break;
1925             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1926                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1927                 break;
1928             default:
1929                 break;
1930         }
1931     }
1932 
1933 #endif
1934 
1935     if (!command_completed) return;
1936 
1937     bool need_baud_change = false;
1938     bool need_addr_change = false;
1939 
1940 #ifndef HAVE_HOST_CONTROLLER_API
1941     need_baud_change = hci_stack->config
1942                         && hci_stack->chipset
1943                         && hci_stack->chipset->set_baudrate_command
1944                         && hci_stack->hci_transport->set_baudrate
1945                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1946 
1947     need_addr_change = hci_stack->custom_bd_addr_set
1948                         && hci_stack->chipset
1949                         && hci_stack->chipset->set_bd_addr_command;
1950 #endif
1951 
1952     switch(hci_stack->substate){
1953 
1954 #ifndef HAVE_HOST_CONTROLLER_API
1955         case HCI_INIT_SEND_RESET:
1956             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1957             // fix: just correct substate and behave as command below
1958 
1959             /* fall through */
1960 #endif
1961 
1962         case HCI_INIT_W4_SEND_RESET:
1963             btstack_run_loop_remove_timer(&hci_stack->timeout);
1964             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1965             return;
1966 
1967 #ifndef HAVE_HOST_CONTROLLER_API
1968         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1969             // for STLC2500D, baud rate change already happened.
1970             // for others, baud rate gets changed now
1971             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1972                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1973                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1974                 hci_stack->hci_transport->set_baudrate(baud_rate);
1975             }
1976             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1977             return;
1978         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1979             btstack_run_loop_remove_timer(&hci_stack->timeout);
1980             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1981             return;
1982         case HCI_INIT_W4_CUSTOM_INIT:
1983             // repeat custom init
1984             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1985             return;
1986 #endif
1987 
1988         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1989             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1990               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1991                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1992                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1993                 return;
1994             }
1995             if (need_addr_change){
1996                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1997                 return;
1998             }
1999             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2000             return;
2001 #ifndef HAVE_HOST_CONTROLLER_API
2002         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
2003             if (need_baud_change){
2004                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
2005                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
2006                 hci_stack->hci_transport->set_baudrate(baud_rate);
2007             }
2008             if (need_addr_change){
2009                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
2010                 return;
2011             }
2012             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2013             return;
2014         case HCI_INIT_W4_SET_BD_ADDR:
2015             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
2016             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
2017             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
2018                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
2019                 return;
2020             }
2021             // skipping st warm boot
2022             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2023             return;
2024         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
2025             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2026             return;
2027 #endif
2028 
2029         case HCI_INIT_DONE:
2030             // set state if we came here by fall through
2031             hci_stack->substate = HCI_INIT_DONE;
2032             return;
2033 
2034         default:
2035             break;
2036     }
2037     hci_initializing_next_state();
2038 }
2039 
2040 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
2041     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
2042     bd_addr_t bd_address;
2043     (void)memcpy(&bd_address, conn->address, 6);
2044 
2045 #ifdef ENABLE_CLASSIC
2046     // cache needed data
2047     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
2048 #endif
2049 
2050     // connection failed, remove entry
2051     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2052     btstack_memory_hci_connection_free( conn );
2053 
2054 #ifdef ENABLE_CLASSIC
2055     // notify client if dedicated bonding
2056     if (notify_dedicated_bonding_failed){
2057         log_info("hci notify_dedicated_bonding_failed");
2058         hci_emit_dedicated_bonding_result(bd_address, status);
2059     }
2060 
2061     // if authentication error, also delete link key
2062     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
2063         gap_drop_link_key_for_bd_addr(bd_address);
2064     }
2065 #else
2066     UNUSED(status);
2067 #endif
2068 }
2069 
2070 #ifdef ENABLE_CLASSIC
2071 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
2072     // SSP Controller
2073     if (features[6] & (1 << 3)){
2074         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
2075     }
2076     // eSCO
2077     if (features[3] & (1<<7)){
2078         conn->remote_supported_features[0] |= 1;
2079     }
2080     // Extended features
2081     if (features[7] & (1<<7)){
2082         conn->remote_supported_features[0] |= 2;
2083     }
2084 }
2085 
2086 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
2087     // SSP Host
2088     if (features[0] & (1 << 0)){
2089         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
2090     }
2091     // SC Host
2092     if (features[0] & (1 << 3)){
2093         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
2094     }
2095 }
2096 
2097 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
2098     // SC Controller
2099     if (features[1] & (1 << 0)){
2100         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2101     }
2102 }
2103 
2104 static void hci_handle_remote_features_received(hci_connection_t * conn){
2105     conn->bonding_flags &= ~BONDING_REMOTE_FEATURES_QUERY_ACTIVE;
2106     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
2107     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
2108     if (conn->bonding_flags & BONDING_DEDICATED){
2109         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2110     }
2111 }
2112 static bool hci_remote_sc_enabled(hci_connection_t * connection){
2113     const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2114     return (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
2115 }
2116 
2117 #endif
2118 
2119 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
2120     // handle BT initialization
2121     if (hci_stack->state == HCI_STATE_INITIALIZING) {
2122         hci_initializing_event_handler(packet, size);
2123     }
2124 
2125     // help with BT sleep
2126     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
2127         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
2128         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
2129         hci_initializing_next_state();
2130     }
2131 }
2132 
2133 #ifdef ENABLE_CLASSIC
2134 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
2135     conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2136     conn->encryption_key_size = encryption_key_size;
2137 
2138     if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) != 0) {
2139         conn->requested_security_level = LEVEL_0;
2140         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
2141         return;
2142     }
2143 
2144     // Request remote features if not already done
2145     hci_trigger_remote_features_for_connection(conn);
2146 
2147     // Request Authentication if not already done
2148     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
2149     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2150 }
2151 #endif
2152 
2153 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
2154     UNUSED(size);
2155 
2156     uint16_t manufacturer;
2157 #ifdef ENABLE_CLASSIC
2158     hci_con_handle_t handle;
2159     hci_connection_t * conn;
2160     uint8_t status;
2161 #endif
2162     // get num cmd packets - limit to 1 to reduce complexity
2163     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2164 
2165     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
2166     switch (opcode){
2167         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
2168             if (packet[5]) break;
2169             // terminate, name 248 chars
2170             packet[6+248] = 0;
2171             log_info("local name: %s", &packet[6]);
2172             break;
2173         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2174             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2175             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2176                 uint16_t acl_len = little_endian_read_16(packet, 6);
2177                 uint16_t sco_len = packet[8];
2178 
2179                 // determine usable ACL/SCO payload size
2180                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2181                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2182 
2183                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2184                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2185 
2186                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2187                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2188                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2189             }
2190             break;
2191         case HCI_OPCODE_HCI_READ_RSSI:
2192             if (packet[5] == ERROR_CODE_SUCCESS){
2193                 uint8_t event[5];
2194                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2195                 event[1] = 3;
2196                 (void)memcpy(&event[2], &packet[6], 3);
2197                 hci_emit_event(event, sizeof(event), 1);
2198             }
2199             break;
2200 #ifdef ENABLE_BLE
2201         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2202             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2203             hci_stack->le_acl_packets_total_num = packet[8];
2204             // determine usable ACL payload size
2205             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2206                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2207             }
2208             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2209             break;
2210 #endif
2211 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2212         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2213             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2214             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2215             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);
2216             break;
2217 #endif
2218 #ifdef ENABLE_LE_CENTRAL
2219         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2220             hci_stack->le_whitelist_capacity = packet[6];
2221             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2222             break;
2223 #endif
2224         case HCI_OPCODE_HCI_READ_BD_ADDR:
2225             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2226             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));
2227 #ifdef ENABLE_CLASSIC
2228             if (hci_stack->link_key_db){
2229                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2230             }
2231 #endif
2232             break;
2233 #ifdef ENABLE_CLASSIC
2234         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2235             hci_emit_discoverable_enabled(hci_stack->discoverable);
2236             break;
2237         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2238             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2239                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2240                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2241                 hci_emit_event(event, sizeof(event), 1);
2242             }
2243             break;
2244 #endif
2245         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2246             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2247 
2248 #ifdef ENABLE_CLASSIC
2249             // determine usable ACL packet types based on host buffer size and supported features
2250             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2251             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2252 #endif
2253             // Classic/LE
2254             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2255             break;
2256         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2257             manufacturer = little_endian_read_16(packet, 10);
2258             // map Cypress to Broadcom
2259             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2260                 log_info("Treat Cypress as Broadcom");
2261                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2262                 little_endian_store_16(packet, 10, manufacturer);
2263             }
2264             hci_stack->manufacturer = manufacturer;
2265             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2266             break;
2267         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2268             hci_stack->local_supported_commands[0] =
2269                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit  0 = Octet 14, bit 7 / Read Buffer Size
2270                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit  1 = Octet 24, bit 6 / Write Le Host Supported
2271                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit  2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2272                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     )  |  // bit  3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2273                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit  4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2274                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit  5 = Octet 35, bit 3 / LE Read Maximum Data Length
2275                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit  6 = Octet 35, bit 5 / LE Set Default PHY
2276                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit  7 = Octet 20, bit 4 / Read Encryption Key Size
2277             hci_stack->local_supported_commands[1] =
2278                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit  8 = Octet  2, bit 6 / Read Remote Extended Features
2279                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u) |  // bit  9 = Octet 32, bit 3 / Write Secure Connections Host
2280                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x02u) << 1u) |  // bit 10 = Octet 35, bit 1 / LE Set Address Resolution Enable
2281                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x02u) << 2u) |  // bit 11 = Octet 32, bit 1 / Remote OOB Extended Data Request Reply
2282                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x40u) >> 2u);   // bit 12 = Octet 32, bit 6 / Read Local OOB Extended Data command
2283             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2284             break;
2285 #ifdef ENABLE_CLASSIC
2286         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2287             if (packet[5]) return;
2288             hci_stack->synchronous_flow_control_enabled = 1;
2289             break;
2290         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2291             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2292             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2293             conn   = hci_connection_for_handle(handle);
2294             if (conn != NULL) {
2295                 uint8_t key_size = 0;
2296                 if (status == 0){
2297                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2298                     log_info("Handle %04x key Size: %u", handle, key_size);
2299                 } else {
2300                     key_size = 1;
2301                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2302                 }
2303                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2304             }
2305             break;
2306         // assert pairing complete event is emitted.
2307         // note: for SSP, Simple Pairing Complete Event is sufficient, but we want to be more robust
2308         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
2309         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
2310         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
2311             hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
2312             // lookup connection by gap pairing addr
2313             conn = hci_connection_for_bd_addr_and_type(hci_stack->gap_pairing_addr, BD_ADDR_TYPE_ACL);
2314             if (conn == NULL) break;
2315             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2316             break;
2317 
2318 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2319         case HCI_OPCODE_HCI_READ_LOCAL_OOB_DATA:
2320         case HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA:{
2321             uint8_t event[67];
2322             event[0] = GAP_EVENT_LOCAL_OOB_DATA;
2323             event[1] = 65;
2324             (void)memset(&event[2], 0, 65);
2325             if (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE] == ERROR_CODE_SUCCESS){
2326                 (void)memcpy(&event[3], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 32);
2327                 if (opcode == HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA){
2328                     event[2] = 3;
2329                     (void)memcpy(&event[35], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+33], 32);
2330                 } else {
2331                     event[2] = 1;
2332                 }
2333             }
2334             hci_emit_event(event, sizeof(event), 0);
2335             break;
2336         }
2337 
2338         // note: only needed if user does not provide OOB data
2339         case HCI_OPCODE_HCI_REMOTE_OOB_DATA_REQUEST_NEGATIVE_REPLY:
2340             conn = hci_connection_for_handle(hci_stack->classic_oob_con_handle);
2341             hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
2342             if (conn == NULL) break;
2343             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2344             break;
2345 #endif
2346 #endif
2347         default:
2348             break;
2349     }
2350 }
2351 
2352 #ifdef ENABLE_BLE
2353 static void event_handle_le_connection_complete(const uint8_t * packet){
2354 	bd_addr_t addr;
2355 	bd_addr_type_t addr_type;
2356 	hci_connection_t * conn;
2357 
2358 	// Connection management
2359 	reverse_bd_addr(&packet[8], addr);
2360 	addr_type = (bd_addr_type_t)packet[7];
2361 	log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2362 	conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2363 
2364 #ifdef ENABLE_LE_CENTRAL
2365 	// handle error: error is reported only to the initiator -> outgoing connection
2366 	if (packet[3]){
2367 
2368 		// handle cancelled outgoing connection
2369 		// "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2370 		//  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2371 		//  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2372 		if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2373 		    // reset state
2374             hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2375             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2376 			// get outgoing connection conn struct for direct connect
2377 			conn = gap_get_outgoing_connection();
2378 		}
2379 
2380 		// outgoing le connection establishment is done
2381 		if (conn){
2382 			// remove entry
2383 			btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2384 			btstack_memory_hci_connection_free( conn );
2385 		}
2386 		return;
2387 	}
2388 #endif
2389 
2390 	// on success, both hosts receive connection complete event
2391 	if (packet[6] == HCI_ROLE_MASTER){
2392 #ifdef ENABLE_LE_CENTRAL
2393 		// if we're master on an le connection, it was an outgoing connection and we're done with it
2394 		// note: no hci_connection_t object exists yet for connect with whitelist
2395 		if (hci_is_le_connection_type(addr_type)){
2396 			hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2397 			hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2398 		}
2399 #endif
2400 	} else {
2401 #ifdef ENABLE_LE_PERIPHERAL
2402 		// if we're slave, it was an incoming connection, advertisements have stopped
2403 		hci_stack->le_advertisements_active = false;
2404 #endif
2405 	}
2406 
2407 	// LE connections are auto-accepted, so just create a connection if there isn't one already
2408 	if (!conn){
2409 		conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2410 	}
2411 
2412 	// no memory, sorry.
2413 	if (!conn){
2414 		return;
2415 	}
2416 
2417 	conn->state = OPEN;
2418 	conn->role  = packet[6];
2419 	conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2420 	conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2421 
2422 #ifdef ENABLE_LE_PERIPHERAL
2423 	if (packet[6] == HCI_ROLE_SLAVE){
2424 		hci_update_advertisements_enabled_for_current_roles();
2425 	}
2426 #endif
2427 
2428     // init unenhanced att bearer mtu
2429     conn->att_connection.mtu = ATT_DEFAULT_MTU;
2430     conn->att_connection.mtu_exchanged = false;
2431 
2432     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2433 
2434 	// restart timer
2435 	// btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2436 	// btstack_run_loop_add_timer(&conn->timeout);
2437 
2438 	log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2439 
2440 	hci_emit_nr_connections_changed();
2441 }
2442 #endif
2443 
2444 #ifdef ENABLE_CLASSIC
2445 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){
2446     if (io_cap_local == SSP_IO_CAPABILITY_UNKNOWN) return false;
2447     // LEVEL_4 is tested by l2cap
2448     // LEVEL 3 requires MITM protection -> check io capabilities if Authenticated is possible
2449     // @see: Core Spec v5.3, Vol 3, Part C, Table 5.7
2450     if (level >= LEVEL_3){
2451         // MITM not possible without keyboard or display
2452         if (io_cap_remote >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2453         if (io_cap_local  >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2454 
2455         // MITM possible if one side has keyboard and the other has keyboard or display
2456         if (io_cap_remote == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2457         if (io_cap_local  == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2458 
2459         // MITM not possible if one side has only display and other side has no keyboard
2460         if (io_cap_remote == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2461         if (io_cap_local  == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2462     }
2463     // LEVEL 2 requires SSP, which is a given
2464     return true;
2465 }
2466 
2467 static bool btstack_is_null(uint8_t * data, uint16_t size){
2468     uint16_t i;
2469     for (i=0; i < size ; i++){
2470         if (data[i] != 0) {
2471             return false;
2472         }
2473     }
2474     return true;
2475 }
2476 
2477 static void hci_ssp_assess_security_on_io_cap_request(hci_connection_t * conn){
2478     // get requested security level
2479     gap_security_level_t requested_security_level = conn->requested_security_level;
2480     if (hci_stack->gap_secure_connections_only_mode){
2481         requested_security_level = LEVEL_4;
2482     }
2483 
2484     // assess security: LEVEL 4 requires SC
2485     // skip this preliminary test if remote features are not available yet to work around potential issue in ESP32 controller
2486     if ((requested_security_level == LEVEL_4) &&
2487         ((conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0) &&
2488         !hci_remote_sc_enabled(conn)){
2489         log_info("Level 4 required, but SC not supported -> abort");
2490         hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2491         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2492         return;
2493     }
2494 
2495     // assess security based on io capabilities
2496     if (conn->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
2497         // responder: fully validate io caps of both sides as well as OOB data
2498         bool security_possible = false;
2499         security_possible = hci_ssp_security_level_possible_for_io_cap(requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io);
2500 
2501 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2502         // We assume that both Controller can reach LEVEL 4, if one side has received P-192 and the other has received P-256,
2503         // so we merge the OOB data availability
2504         uint8_t have_oob_data = conn->io_cap_response_oob_data;
2505         if (conn->classic_oob_c_192 != NULL){
2506             have_oob_data |= 1;
2507         }
2508         if (conn->classic_oob_c_256 != NULL){
2509             have_oob_data |= 2;
2510         }
2511         // for up to Level 3, either P-192 as well as P-256 will do
2512         // 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
2513         // if remote does not SC, we should not receive P-256 data either
2514         if ((requested_security_level <= LEVEL_3) && (have_oob_data != 0)){
2515             security_possible = true;
2516         }
2517         // for Level 4, P-256 is needed
2518         if ((requested_security_level == LEVEL_4 && ((have_oob_data & 2) != 0))){
2519             security_possible = true;
2520         }
2521 #endif
2522 
2523         if (security_possible == false){
2524             log_info("IOCap/OOB insufficient for level %u -> abort", requested_security_level);
2525             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2526             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2527             return;
2528         }
2529     } else {
2530         // initiator: remote io cap not yet, only check if we have ability for MITM protection if requested and OOB is not supported
2531 #ifndef ENABLE_CLASSIC_PAIRING_OOB
2532 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2533         if ((conn->requested_security_level >= LEVEL_3) && (hci_stack->ssp_io_capability >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT)){
2534             log_info("Level 3+ required, but no input/output -> abort");
2535             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2536             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2537             return;
2538         }
2539 #endif
2540 #endif
2541     }
2542 
2543 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2544     if (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN){
2545         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
2546     } else {
2547         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2548     }
2549 #endif
2550 }
2551 
2552 #endif
2553 
2554 static void event_handler(uint8_t *packet, uint16_t size){
2555 
2556     uint16_t event_length = packet[1];
2557 
2558     // assert packet is complete
2559     if (size != (event_length + 2u)){
2560         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2561         return;
2562     }
2563 
2564     bd_addr_type_t addr_type;
2565     hci_con_handle_t handle;
2566     hci_connection_t * conn;
2567     int i;
2568     int create_connection_cmd;
2569 
2570 #ifdef ENABLE_CLASSIC
2571     hci_link_type_t link_type;
2572     bd_addr_t addr;
2573 #endif
2574 
2575     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2576 
2577     switch (hci_event_packet_get_type(packet)) {
2578 
2579         case HCI_EVENT_COMMAND_COMPLETE:
2580             handle_command_complete_event(packet, size);
2581             break;
2582 
2583         case HCI_EVENT_COMMAND_STATUS:
2584             // get num cmd packets - limit to 1 to reduce complexity
2585             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2586 
2587             // check command status to detected failed outgoing connections
2588             create_connection_cmd = 0;
2589 #ifdef ENABLE_CLASSIC
2590             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2591                 create_connection_cmd = 1;
2592             }
2593 #endif
2594 #ifdef ENABLE_LE_CENTRAL
2595             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2596                 create_connection_cmd = 1;
2597             }
2598 #endif
2599             if (create_connection_cmd) {
2600                 uint8_t status = hci_event_command_status_get_status(packet);
2601                 addr_type = hci_stack->outgoing_addr_type;
2602                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, addr_type);
2603                 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);
2604 
2605                 // reset outgoing address info
2606                 memset(hci_stack->outgoing_addr, 0, 6);
2607                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2608 
2609                 // on error
2610                 if (status != ERROR_CODE_SUCCESS){
2611 #ifdef ENABLE_LE_CENTRAL
2612                     if (hci_is_le_connection_type(addr_type)){
2613                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2614                         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2615                     }
2616 #endif
2617                     // error => outgoing connection failed
2618                     if (conn != NULL){
2619                         hci_handle_connection_failed(conn, status);
2620                     }
2621                 }
2622             }
2623 
2624 #ifdef ENABLE_CLASSIC
2625             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_inquiry)) {
2626                 uint8_t status = hci_event_command_status_get_status(packet);
2627                 log_info("command status (inquiry), status %x", status);
2628                 if (status == ERROR_CODE_SUCCESS) {
2629                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
2630                 } else {
2631                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2632                 }
2633             }
2634 #endif
2635             break;
2636 
2637         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2638             if (size < 3) return;
2639             uint16_t num_handles = packet[2];
2640             if (size != (3u + num_handles * 4u)) return;
2641             uint16_t offset = 3;
2642             for (i=0; i<num_handles;i++){
2643                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2644                 offset += 2u;
2645                 uint16_t num_packets = little_endian_read_16(packet, offset);
2646                 offset += 2u;
2647 
2648                 conn = hci_connection_for_handle(handle);
2649                 if (!conn){
2650                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2651                     continue;
2652                 }
2653 
2654                 if (conn->num_packets_sent >= num_packets){
2655                     conn->num_packets_sent -= num_packets;
2656                 } else {
2657                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2658                     conn->num_packets_sent = 0;
2659                 }
2660                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2661 
2662 #ifdef ENABLE_CLASSIC
2663                 // For SCO, we do the can_send_now_check here
2664                 hci_notify_if_sco_can_send_now();
2665 #endif
2666             }
2667             break;
2668         }
2669 
2670 #ifdef ENABLE_CLASSIC
2671         case HCI_EVENT_INQUIRY_COMPLETE:
2672             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2673                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2674                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2675                 hci_emit_event(event, sizeof(event), 1);
2676             }
2677             break;
2678         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2679             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2680                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2681             }
2682             break;
2683         case HCI_EVENT_CONNECTION_REQUEST:
2684             reverse_bd_addr(&packet[2], addr);
2685             link_type = (hci_link_type_t) packet[11];
2686 
2687             // CVE-2020-26555: reject incoming connection from device with same BD ADDR
2688             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0){
2689                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2690                 bd_addr_copy(hci_stack->decline_addr, addr);
2691                 break;
2692             }
2693 
2694             if (hci_stack->gap_classic_accept_callback != NULL){
2695                 if ((*hci_stack->gap_classic_accept_callback)(addr, link_type) == 0){
2696                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2697                     bd_addr_copy(hci_stack->decline_addr, addr);
2698                     break;
2699                 }
2700             }
2701 
2702             // TODO: eval COD 8-10
2703             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), (unsigned int) link_type);
2704             addr_type = (link_type == HCI_LINK_TYPE_ACL) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2705             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2706             if (!conn) {
2707                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2708             }
2709             if (!conn) {
2710                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2711                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2712                 bd_addr_copy(hci_stack->decline_addr, addr);
2713                 break;
2714             }
2715             conn->role  = HCI_ROLE_SLAVE;
2716             conn->state = RECEIVED_CONNECTION_REQUEST;
2717             // store info about eSCO
2718             if (link_type == HCI_LINK_TYPE_ESCO){
2719                 conn->remote_supported_features[0] |= 1;
2720             }
2721             hci_run();
2722             break;
2723 
2724         case HCI_EVENT_CONNECTION_COMPLETE:
2725             // Connection management
2726             reverse_bd_addr(&packet[5], addr);
2727             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2728             addr_type = BD_ADDR_TYPE_ACL;
2729             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2730             if (conn) {
2731                 if (!packet[2]){
2732                     conn->state = OPEN;
2733                     conn->con_handle = little_endian_read_16(packet, 3);
2734 
2735                     // queue set supervision timeout if we're master
2736                     if ((hci_stack->link_supervision_timeout != HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT) && (conn->role == HCI_ROLE_MASTER)){
2737                         connectionSetAuthenticationFlags(conn, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
2738                     }
2739 
2740                     // restart timer
2741                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2742                     btstack_run_loop_add_timer(&conn->timeout);
2743 
2744                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2745 
2746                     hci_emit_nr_connections_changed();
2747                 } else {
2748                     // connection failed
2749                     hci_handle_connection_failed(conn, packet[2]);
2750                 }
2751             }
2752             break;
2753 
2754         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2755             reverse_bd_addr(&packet[5], addr);
2756             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2757             if (packet[2]){
2758                 // connection failed
2759                 break;
2760             }
2761             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2762             if (!conn) {
2763                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2764             }
2765             if (!conn) {
2766                 break;
2767             }
2768             conn->state = OPEN;
2769             conn->con_handle = little_endian_read_16(packet, 3);
2770 
2771 #ifdef ENABLE_SCO_OVER_HCI
2772             // update SCO
2773             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2774                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2775             }
2776             // trigger can send now
2777             if (hci_have_usb_transport()){
2778                 hci_stack->sco_can_send_now = true;
2779             }
2780 #endif
2781 #ifdef HAVE_SCO_TRANSPORT
2782             // configure sco transport
2783             if (hci_stack->sco_transport != NULL){
2784                 sco_format_t sco_format = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? SCO_FORMAT_8_BIT : SCO_FORMAT_16_BIT;
2785                 hci_stack->sco_transport->open(conn->con_handle, sco_format);
2786             }
2787 #endif
2788             break;
2789 
2790         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2791             handle = little_endian_read_16(packet, 3);
2792             conn = hci_connection_for_handle(handle);
2793             if (!conn) break;
2794             if (!packet[2]){
2795                 const uint8_t * features = &packet[5];
2796                 hci_handle_remote_features_page_0(conn, features);
2797 
2798                 // read extended features if possible
2799                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2800                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2801                     break;
2802                 }
2803             }
2804             hci_handle_remote_features_received(conn);
2805             break;
2806 
2807         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2808             handle = little_endian_read_16(packet, 3);
2809             conn = hci_connection_for_handle(handle);
2810             if (!conn) break;
2811             // status = ok, page = 1
2812             if (!packet[2]) {
2813                 uint8_t page_number = packet[5];
2814                 uint8_t maximum_page_number = packet[6];
2815                 const uint8_t * features = &packet[7];
2816                 bool done = false;
2817                 switch (page_number){
2818                     case 1:
2819                         hci_handle_remote_features_page_1(conn, features);
2820                         if (maximum_page_number >= 2){
2821                             // get Secure Connections (Controller) from Page 2 if available
2822                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2823                         } else {
2824                             // otherwise, assume SC (Controller) == SC (Host)
2825                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2826                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2827                             }
2828                             done = true;
2829                         }
2830                         break;
2831                     case 2:
2832                         hci_handle_remote_features_page_2(conn, features);
2833                         done = true;
2834                         break;
2835                     default:
2836                         break;
2837                 }
2838                 if (!done) break;
2839             }
2840             hci_handle_remote_features_received(conn);
2841             break;
2842 
2843         case HCI_EVENT_LINK_KEY_REQUEST:
2844 #ifndef ENABLE_EXPLICIT_LINK_KEY_REPLY
2845             hci_event_link_key_request_get_bd_addr(packet, addr);
2846             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2847             if (!conn) break;
2848 
2849             // lookup link key in db if not cached
2850             if ((conn->link_key_type == INVALID_LINK_KEY) && (hci_stack->link_key_db != NULL)){
2851                 hci_stack->link_key_db->get_link_key(conn->address, conn->link_key, &conn->link_key_type);
2852             }
2853 
2854             // response sent by hci_run()
2855             conn->authentication_flags |= AUTH_FLAG_HANDLE_LINK_KEY_REQUEST;
2856 #endif
2857             break;
2858 
2859         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2860             hci_event_link_key_request_get_bd_addr(packet, addr);
2861             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2862             if (!conn) break;
2863 
2864             hci_pairing_complete(conn, ERROR_CODE_SUCCESS);
2865 
2866             // CVE-2020-26555: ignore NULL link key
2867             // default link_key_type = INVALID_LINK_KEY asserts that NULL key won't be used for encryption
2868             if (btstack_is_null(&packet[8], 16)) break;
2869 
2870             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2871             // Change Connection Encryption keeps link key type
2872             if (link_key_type != CHANGED_COMBINATION_KEY){
2873                 conn->link_key_type = link_key_type;
2874             }
2875 
2876             // cache link key. link keys stored in little-endian format for legacy reasons
2877             memcpy(&conn->link_key, &packet[8], 16);
2878 
2879             // only store link key:
2880             // - if bondable enabled
2881             if (hci_stack->bondable == false) break;
2882             // - if security level sufficient
2883             if (gap_security_level_for_link_key_type(link_key_type) < conn->requested_security_level) break;
2884             // - for SSP, also check if remote side requested bonding as well
2885             if (conn->link_key_type != COMBINATION_KEY){
2886                 bool remote_bonding = conn->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2887                 if (!remote_bonding){
2888                     break;
2889                 }
2890             }
2891             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2892             break;
2893         }
2894 
2895         case HCI_EVENT_PIN_CODE_REQUEST:
2896             hci_event_pin_code_request_get_bd_addr(packet, addr);
2897             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2898             if (!conn) break;
2899 
2900             hci_pairing_started(conn, false);
2901             // abort pairing if: non-bondable mode (pin code request is not forwarded to app)
2902             if (!hci_stack->bondable ){
2903                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2904                 hci_pairing_complete(conn, ERROR_CODE_PAIRING_NOT_ALLOWED);
2905                 hci_run();
2906                 return;
2907             }
2908             // abort pairing if: LEVEL_4 required (pin code request is not forwarded to app)
2909             if ((hci_stack->gap_secure_connections_only_mode) || (conn->requested_security_level == LEVEL_4)){
2910                 log_info("Level 4 required, but SC not supported -> abort");
2911                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2912                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2913                 hci_run();
2914                 return;
2915             }
2916             break;
2917 
2918         case HCI_EVENT_IO_CAPABILITY_RESPONSE:
2919             hci_event_io_capability_response_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_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE);
2924             hci_pairing_started(conn, true);
2925             conn->io_cap_response_auth_req = hci_event_io_capability_response_get_authentication_requirements(packet);
2926             conn->io_cap_response_io       = hci_event_io_capability_response_get_io_capability(packet);
2927 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2928             conn->io_cap_response_oob_data = hci_event_io_capability_response_get_oob_data_present(packet);
2929 #endif
2930             break;
2931 
2932         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2933             hci_event_io_capability_response_get_bd_addr(packet, addr);
2934             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2935             if (!conn) break;
2936 
2937             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
2938             hci_connection_timestamp(conn);
2939             hci_pairing_started(conn, true);
2940             break;
2941 
2942 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2943         case HCI_EVENT_REMOTE_OOB_DATA_REQUEST:
2944             hci_event_remote_oob_data_request_get_bd_addr(packet, addr);
2945             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2946             if (!conn) break;
2947 
2948             hci_connection_timestamp(conn);
2949 
2950             hci_pairing_started(conn, true);
2951 
2952             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
2953             break;
2954 #endif
2955 
2956         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2957             hci_event_user_confirmation_request_get_bd_addr(packet, addr);
2958             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2959             if (!conn) break;
2960             if (hci_ssp_security_level_possible_for_io_cap(conn->requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io)) {
2961                 if (hci_stack->ssp_auto_accept){
2962                     hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
2963                 };
2964             } else {
2965                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2966                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
2967                 // don't forward event to app
2968                 hci_run();
2969                 return;
2970             }
2971             break;
2972 
2973         case HCI_EVENT_USER_PASSKEY_REQUEST:
2974             // Pairing using Passkey results in MITM protection. If Level 4 is required, support for SC is validated on IO Cap Request
2975             if (hci_stack->ssp_auto_accept){
2976                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
2977             };
2978             break;
2979 
2980         case HCI_EVENT_MODE_CHANGE:
2981             handle = hci_event_mode_change_get_handle(packet);
2982             conn = hci_connection_for_handle(handle);
2983             if (!conn) break;
2984             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2985             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2986             break;
2987 #endif
2988 
2989         case HCI_EVENT_ENCRYPTION_CHANGE:
2990             handle = hci_event_encryption_change_get_connection_handle(packet);
2991             conn = hci_connection_for_handle(handle);
2992             if (!conn) break;
2993             if (hci_event_encryption_change_get_status(packet) == 0u) {
2994                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2995                 if (encryption_enabled){
2996                     if (hci_is_le_connection(conn)){
2997                         // For LE, we accept connection as encrypted
2998                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2999                     }
3000 #ifdef ENABLE_CLASSIC
3001                     else {
3002 
3003                         // dedicated bonding: send result and disconnect
3004                         if (conn->bonding_flags & BONDING_DEDICATED){
3005                             conn->bonding_flags &= ~BONDING_DEDICATED;
3006                             conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
3007                             conn->bonding_status = packet[2];
3008                             break;
3009                         }
3010 
3011                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
3012                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
3013                         bool connected_uses_aes_ccm = encryption_enabled == 2;
3014                         if (hci_stack->secure_connections_active && sc_used_during_pairing && !connected_uses_aes_ccm){
3015                             log_info("SC during pairing, but only E0 now -> abort");
3016                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
3017                             break;
3018                         }
3019 
3020                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
3021                         if (connected_uses_aes_ccm){
3022                             conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3023                         }
3024 
3025 #ifdef ENABLE_TESTING_SUPPORT
3026                         // work around for issue with PTS dongle
3027                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3028 #endif
3029 
3030                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
3031                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
3032                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3033                         } else {
3034                             // if not, pretend everything is perfect
3035                             hci_handle_read_encryption_key_size_complete(conn, 16);
3036                         }
3037                     }
3038 #endif
3039                 } else {
3040                     conn->authentication_flags &= ~AUTH_FLAG_CONNECTION_ENCRYPTED;
3041                 }
3042             }
3043 
3044             break;
3045 
3046 #ifdef ENABLE_CLASSIC
3047         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
3048             handle = hci_event_authentication_complete_get_connection_handle(packet);
3049             conn = hci_connection_for_handle(handle);
3050             if (!conn) break;
3051 
3052             // clear authentication active flag
3053             conn->bonding_flags &= ~BONDING_SENT_AUTHENTICATE_REQUEST;
3054             hci_pairing_complete(conn, hci_event_authentication_complete_get_status(packet));
3055 
3056             // authenticated only if auth status == 0
3057             if (hci_event_authentication_complete_get_status(packet) == 0){
3058                 // authenticated
3059                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3060 
3061                 // If not already encrypted, start encryption
3062                 if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0){
3063                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3064                     break;
3065                 }
3066             }
3067 
3068             // emit updated security level
3069             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
3070             break;
3071 
3072         case HCI_EVENT_SIMPLE_PAIRING_COMPLETE:
3073             hci_event_simple_pairing_complete_get_bd_addr(packet, addr);
3074             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3075             if (!conn) break;
3076 
3077             // treat successfully paired connection as authenticated
3078             if (hci_event_simple_pairing_complete_get_status(packet) == ERROR_CODE_SUCCESS){
3079                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3080             }
3081 
3082             hci_pairing_complete(conn, hci_event_simple_pairing_complete_get_status(packet));
3083             break;
3084 #endif
3085 
3086         // HCI_EVENT_DISCONNECTION_COMPLETE
3087         // has been split, to first notify stack before shutting connection down
3088         // see end of function, too.
3089         case HCI_EVENT_DISCONNECTION_COMPLETE:
3090             if (packet[2]) break;   // status != 0
3091             handle = little_endian_read_16(packet, 3);
3092             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
3093             if (hci_stack->acl_fragmentation_total_size > 0u) {
3094                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
3095                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
3096                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
3097                     hci_stack->acl_fragmentation_total_size = 0;
3098                     hci_stack->acl_fragmentation_pos = 0;
3099                     if (release_buffer){
3100                         hci_release_packet_buffer();
3101                     }
3102                 }
3103             }
3104 
3105             conn = hci_connection_for_handle(handle);
3106             if (!conn) break;
3107 #ifdef ENABLE_CLASSIC
3108             // pairing failed if it was ongoing
3109             hci_pairing_complete(conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3110 #endif
3111 
3112             // emit dedicatd bonding event
3113             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
3114                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
3115             }
3116 
3117             // mark connection for shutdown, stop timers, reset state
3118             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
3119             hci_connection_stop_timer(conn);
3120             hci_connection_init(conn);
3121 
3122 #ifdef ENABLE_BLE
3123 #ifdef ENABLE_LE_PERIPHERAL
3124             // re-enable advertisements for le connections if active
3125             if (hci_is_le_connection(conn)){
3126                 hci_update_advertisements_enabled_for_current_roles();
3127             }
3128 #endif
3129 #endif
3130             break;
3131 
3132         case HCI_EVENT_HARDWARE_ERROR:
3133             log_error("Hardware Error: 0x%02x", packet[2]);
3134             if (hci_stack->hardware_error_callback){
3135                 (*hci_stack->hardware_error_callback)(packet[2]);
3136             } else {
3137                 // if no special requests, just reboot stack
3138                 hci_power_control_off();
3139                 hci_power_control_on();
3140             }
3141             break;
3142 
3143 #ifdef ENABLE_CLASSIC
3144         case HCI_EVENT_ROLE_CHANGE:
3145             if (packet[2]) break;   // status != 0
3146             reverse_bd_addr(&packet[3], addr);
3147             addr_type = BD_ADDR_TYPE_ACL;
3148             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3149             if (!conn) break;
3150             conn->role = packet[9];
3151             break;
3152 #endif
3153 
3154         case HCI_EVENT_TRANSPORT_PACKET_SENT:
3155             // release packet buffer only for asynchronous transport and if there are not further fragements
3156             if (hci_transport_synchronous()) {
3157                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
3158                 return; // instead of break: to avoid re-entering hci_run()
3159             }
3160             hci_stack->acl_fragmentation_tx_active = 0;
3161             if (hci_stack->acl_fragmentation_total_size) break;
3162             hci_release_packet_buffer();
3163 
3164             // L2CAP receives this event via the hci_emit_event below
3165 
3166 #ifdef ENABLE_CLASSIC
3167             // For SCO, we do the can_send_now_check here
3168             hci_notify_if_sco_can_send_now();
3169 #endif
3170             break;
3171 
3172 #ifdef ENABLE_CLASSIC
3173         case HCI_EVENT_SCO_CAN_SEND_NOW:
3174             // For SCO, we do the can_send_now_check here
3175             hci_stack->sco_can_send_now = true;
3176             hci_notify_if_sco_can_send_now();
3177             return;
3178 
3179         // explode inquriy results for easier consumption
3180         case HCI_EVENT_INQUIRY_RESULT:
3181         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
3182         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
3183             gap_inquiry_explode(packet, size);
3184             break;
3185 #endif
3186 
3187 #ifdef ENABLE_BLE
3188         case HCI_EVENT_LE_META:
3189             switch (packet[2]){
3190 #ifdef ENABLE_LE_CENTRAL
3191                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
3192                     // log_info("advertising report received");
3193                     if (!hci_stack->le_scanning_enabled) break;
3194                     le_handle_advertisement_report(packet, size);
3195                     break;
3196 #endif
3197                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
3198 					event_handle_le_connection_complete(packet);
3199                     break;
3200 
3201                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
3202                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
3203                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
3204                     conn = hci_connection_for_handle(handle);
3205                     if (!conn) break;
3206                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
3207                     break;
3208 
3209                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
3210                     // connection
3211                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
3212                     conn = hci_connection_for_handle(handle);
3213                     if (conn) {
3214                         // read arguments
3215                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
3216                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
3217                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
3218                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
3219 
3220                         // validate against current connection parameter range
3221                         le_connection_parameter_range_t existing_range;
3222                         gap_get_connection_parameter_range(&existing_range);
3223                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
3224                         if (update_parameter){
3225                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
3226                             conn->le_conn_interval_min = le_conn_interval_min;
3227                             conn->le_conn_interval_max = le_conn_interval_max;
3228                             conn->le_conn_latency = le_conn_latency;
3229                             conn->le_supervision_timeout = le_supervision_timeout;
3230                         } else {
3231                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NEGATIVE_REPLY;
3232                         }
3233                     }
3234                     break;
3235 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
3236                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
3237                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
3238                     conn = hci_connection_for_handle(handle);
3239                     if (conn) {
3240                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
3241                     }
3242                     break;
3243 #endif
3244                 default:
3245                     break;
3246             }
3247             break;
3248 #endif
3249         case HCI_EVENT_VENDOR_SPECIFIC:
3250             // Vendor specific commands often create vendor specific event instead of num completed packets
3251             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
3252             switch (hci_stack->manufacturer){
3253                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
3254                     hci_stack->num_cmd_packets = 1;
3255                     break;
3256                 default:
3257                     break;
3258             }
3259             break;
3260         default:
3261             break;
3262     }
3263 
3264     handle_event_for_current_stack_state(packet, size);
3265 
3266     // notify upper stack
3267 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
3268 
3269     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
3270     if ((hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE) && (packet[2] == 0)){
3271 		handle = little_endian_read_16(packet, 3);
3272 		hci_connection_t * aConn = hci_connection_for_handle(handle);
3273 		// discard connection if app did not trigger a reconnect in the event handler
3274 		if (aConn && aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
3275 			hci_shutdown_connection(aConn);
3276 		}
3277     }
3278 
3279 	// execute main loop
3280 	hci_run();
3281 }
3282 
3283 #ifdef ENABLE_CLASSIC
3284 
3285 #ifdef ENABLE_SCO_OVER_HCI
3286 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
3287 static void sco_schedule_tx(hci_connection_t * conn);
3288 
3289 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
3290     log_debug("SCO TX Timeout");
3291     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
3292     hci_connection_t * conn = hci_connection_for_handle(con_handle);
3293     if (!conn) return;
3294 
3295     // trigger send
3296     conn->sco_tx_ready = 1;
3297     // extra packet if CVSD but SCO buffer is too short
3298     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
3299         conn->sco_tx_ready++;
3300     }
3301     hci_notify_if_sco_can_send_now();
3302 }
3303 
3304 
3305 #define SCO_TX_AFTER_RX_MS (6)
3306 
3307 static void sco_schedule_tx(hci_connection_t * conn){
3308 
3309     uint32_t now = btstack_run_loop_get_time_ms();
3310     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
3311     int time_delta_ms = sco_tx_ms - now;
3312 
3313     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
3314 
3315     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
3316     btstack_run_loop_remove_timer(timer);
3317     btstack_run_loop_set_timer(timer, time_delta_ms);
3318     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
3319     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
3320     btstack_run_loop_add_timer(timer);
3321 }
3322 #endif
3323 
3324 static void sco_handler(uint8_t * packet, uint16_t size){
3325     // lookup connection struct
3326     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
3327     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
3328     if (!conn) return;
3329 
3330 #ifdef ENABLE_SCO_OVER_HCI
3331     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
3332     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
3333         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
3334             packet[2] = 0x3c;
3335             memmove(&packet[3], &packet[23], 63);
3336             size = 63;
3337         }
3338     }
3339 
3340     if (hci_have_usb_transport()){
3341         // Nothing to do
3342     } else {
3343         // 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);
3344         if (hci_stack->synchronous_flow_control_enabled == 0){
3345             uint32_t now = btstack_run_loop_get_time_ms();
3346 
3347             if (!conn->sco_rx_valid){
3348                 // ignore first 10 packets
3349                 conn->sco_rx_count++;
3350                 // log_debug("sco rx count %u", conn->sco_rx_count);
3351                 if (conn->sco_rx_count == 10) {
3352                     // use first timestamp as is and pretent it just started
3353                     conn->sco_rx_ms = now;
3354                     conn->sco_rx_valid = 1;
3355                     conn->sco_rx_count = 0;
3356                     sco_schedule_tx(conn);
3357                 }
3358             } else {
3359                 // track expected arrival timme
3360                 conn->sco_rx_count++;
3361                 conn->sco_rx_ms += 7;
3362                 int delta = (int32_t) (now - conn->sco_rx_ms);
3363                 if (delta > 0){
3364                     conn->sco_rx_ms++;
3365                 }
3366                 // log_debug("sco rx %u", conn->sco_rx_ms);
3367                 sco_schedule_tx(conn);
3368             }
3369         }
3370     }
3371 #endif
3372 
3373     // deliver to app
3374     if (hci_stack->sco_packet_handler) {
3375         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
3376     }
3377 
3378 #ifdef HAVE_SCO_TRANSPORT
3379     // We can send one packet for each received packet
3380     conn->sco_tx_ready++;
3381     hci_notify_if_sco_can_send_now();
3382 #endif
3383 
3384 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3385     conn->num_packets_completed++;
3386     hci_stack->host_completed_packets = 1;
3387     hci_run();
3388 #endif
3389 }
3390 #endif
3391 
3392 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
3393     hci_dump_packet(packet_type, 1, packet, size);
3394     switch (packet_type) {
3395         case HCI_EVENT_PACKET:
3396             event_handler(packet, size);
3397             break;
3398         case HCI_ACL_DATA_PACKET:
3399             acl_handler(packet, size);
3400             break;
3401 #ifdef ENABLE_CLASSIC
3402         case HCI_SCO_DATA_PACKET:
3403             sco_handler(packet, size);
3404             break;
3405 #endif
3406         default:
3407             break;
3408     }
3409 }
3410 
3411 /**
3412  * @brief Add event packet handler.
3413  */
3414 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
3415     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3416 }
3417 
3418 /**
3419  * @brief Remove event packet handler.
3420  */
3421 void hci_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){
3422     btstack_linked_list_remove(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3423 }
3424 
3425 /** Register HCI packet handlers */
3426 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
3427     hci_stack->acl_packet_handler = handler;
3428 }
3429 
3430 #ifdef ENABLE_CLASSIC
3431 /**
3432  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
3433  */
3434 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
3435     hci_stack->sco_packet_handler = handler;
3436 }
3437 #endif
3438 
3439 static void hci_state_reset(void){
3440     // no connections yet
3441     hci_stack->connections = NULL;
3442 
3443     // keep discoverable/connectable as this has been requested by the client(s)
3444     // hci_stack->discoverable = 0;
3445     // hci_stack->connectable = 0;
3446     // hci_stack->bondable = 1;
3447     // hci_stack->own_addr_type = 0;
3448 
3449     // buffer is free
3450     hci_stack->hci_packet_buffer_reserved = false;
3451 
3452     // no pending cmds
3453     hci_stack->decline_reason = 0;
3454 
3455     hci_stack->secure_connections_active = false;
3456 
3457 #ifdef ENABLE_CLASSIC
3458     hci_stack->inquiry_lap = GAP_IAC_GENERAL_INQUIRY;
3459     hci_stack->page_timeout = 0x6000;  // ca. 15 sec
3460 
3461     hci_stack->gap_tasks =
3462             GAP_TASK_SET_DEFAULT_LINK_POLICY |
3463             GAP_TASK_SET_CLASS_OF_DEVICE |
3464             GAP_TASK_SET_LOCAL_NAME |
3465             GAP_TASK_SET_EIR_DATA |
3466             GAP_TASK_WRITE_SCAN_ENABLE |
3467             GAP_TASK_WRITE_PAGE_TIMEOUT;
3468 #endif
3469 
3470 #ifdef ENABLE_CLASSIC_PAIRING_OOB
3471     hci_stack->classic_read_local_oob_data = false;
3472     hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
3473 #endif
3474 
3475     // LE
3476 #ifdef ENABLE_BLE
3477     memset(hci_stack->le_random_address, 0, 6);
3478     hci_stack->le_random_address_set = 0;
3479 #endif
3480 #ifdef ENABLE_LE_CENTRAL
3481     hci_stack->le_scanning_active  = false;
3482     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3483     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
3484     hci_stack->le_whitelist_capacity = 0;
3485 #endif
3486 #ifdef ENABLE_LE_PERIPHERAL
3487     hci_stack->le_advertisements_active = false;
3488     if ((hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_PARAMS_SET) != 0){
3489         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3490     }
3491     if (hci_stack->le_advertisements_data != NULL){
3492         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3493     }
3494 #endif
3495 }
3496 
3497 #ifdef ENABLE_CLASSIC
3498 /**
3499  * @brief Configure Bluetooth hardware control. Has to be called before power on.
3500  */
3501 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
3502     // store and open remote device db
3503     hci_stack->link_key_db = link_key_db;
3504     if (hci_stack->link_key_db) {
3505         hci_stack->link_key_db->open();
3506     }
3507 }
3508 #endif
3509 
3510 void hci_init(const hci_transport_t *transport, const void *config){
3511 
3512 #ifdef HAVE_MALLOC
3513     if (!hci_stack) {
3514         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
3515     }
3516 #else
3517     hci_stack = &hci_stack_static;
3518 #endif
3519     memset(hci_stack, 0, sizeof(hci_stack_t));
3520 
3521     // reference to use transport layer implementation
3522     hci_stack->hci_transport = transport;
3523 
3524     // reference to used config
3525     hci_stack->config = config;
3526 
3527     // setup pointer for outgoing packet buffer
3528     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3529 
3530     // max acl payload size defined in config.h
3531     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3532 
3533     // register packet handlers with transport
3534     transport->register_packet_handler(&packet_handler);
3535 
3536     hci_stack->state = HCI_STATE_OFF;
3537 
3538     // class of device
3539     hci_stack->class_of_device = 0x007a020c; // Smartphone
3540 
3541     // bondable by default
3542     hci_stack->bondable = 1;
3543 
3544 #ifdef ENABLE_CLASSIC
3545     // classic name
3546     hci_stack->local_name = default_classic_name;
3547 
3548     // Master slave policy
3549     hci_stack->master_slave_policy = 1;
3550 
3551     // Allow Role Switch
3552     hci_stack->allow_role_switch = 1;
3553 
3554     // Default / minimum security level = 2
3555     hci_stack->gap_security_level = LEVEL_2;
3556 
3557     // Default Security Mode 4
3558     hci_stack->gap_security_mode = GAP_SECURITY_MODE_4;
3559 
3560     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3561     hci_stack->gap_required_encyrption_key_size = 7;
3562 
3563     // Link Supervision Timeout
3564     hci_stack->link_supervision_timeout = HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT;
3565 
3566 #endif
3567 
3568     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3569     hci_stack->ssp_enable = 1;
3570     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3571     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3572     hci_stack->ssp_auto_accept = 1;
3573 
3574     // Secure Connections: enable (requires support from Controller)
3575     hci_stack->secure_connections_enable = true;
3576 
3577     // voice setting - signed 16 bit pcm data with CVSD over the air
3578     hci_stack->sco_voice_setting = 0x60;
3579 
3580 #ifdef ENABLE_LE_CENTRAL
3581     // connection parameter to use for outgoing connections
3582     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3583     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3584     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3585     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3586     hci_stack->le_connection_latency      = 4;         // 4
3587     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3588     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3589     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3590 
3591     // default LE Scanning
3592     hci_stack->le_scan_type     =   0x1; // active
3593     hci_stack->le_scan_interval = 0x1e0; // 300 ms
3594     hci_stack->le_scan_window   =  0x30; //  30 ms
3595 #endif
3596 
3597 #ifdef ENABLE_LE_PERIPHERAL
3598     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3599 #endif
3600 
3601     // connection parameter range used to answer connection parameter update requests in l2cap
3602     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3603     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3604     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3605     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3606     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3607     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3608 
3609     hci_state_reset();
3610 }
3611 
3612 void hci_deinit(void){
3613 #ifdef HAVE_MALLOC
3614     if (hci_stack) {
3615         free(hci_stack);
3616     }
3617 #endif
3618     hci_stack = NULL;
3619 
3620 #ifdef ENABLE_CLASSIC
3621     disable_l2cap_timeouts = 0;
3622 #endif
3623 }
3624 
3625 /**
3626  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3627  */
3628 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3629     hci_stack->chipset = chipset_driver;
3630 
3631     // reset chipset driver - init is also called on power_up
3632     if (hci_stack->chipset && hci_stack->chipset->init){
3633         hci_stack->chipset->init(hci_stack->config);
3634     }
3635 }
3636 
3637 /**
3638  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3639  */
3640 void hci_set_control(const btstack_control_t *hardware_control){
3641     // references to used control implementation
3642     hci_stack->control = hardware_control;
3643     // init with transport config
3644     hardware_control->init(hci_stack->config);
3645 }
3646 
3647 void hci_close(void){
3648 
3649 #ifdef ENABLE_CLASSIC
3650     // close remote device db
3651     if (hci_stack->link_key_db) {
3652         hci_stack->link_key_db->close();
3653     }
3654 #endif
3655 
3656     btstack_linked_list_iterator_t lit;
3657     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3658     while (btstack_linked_list_iterator_has_next(&lit)){
3659         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3660         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3661         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3662         hci_shutdown_connection(connection);
3663     }
3664 
3665     hci_power_control(HCI_POWER_OFF);
3666 
3667 #ifdef HAVE_MALLOC
3668     free(hci_stack);
3669 #endif
3670     hci_stack = NULL;
3671 }
3672 
3673 #ifdef HAVE_SCO_TRANSPORT
3674 void hci_set_sco_transport(const btstack_sco_transport_t *sco_transport){
3675     hci_stack->sco_transport = sco_transport;
3676     sco_transport->register_packet_handler(&packet_handler);
3677 }
3678 #endif
3679 
3680 #ifdef ENABLE_CLASSIC
3681 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3682     // validate ranage and set
3683     if (encryption_key_size < 7)  return;
3684     if (encryption_key_size > 16) return;
3685     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3686 }
3687 
3688 uint8_t gap_set_security_mode(gap_security_mode_t security_mode){
3689     if ((security_mode == GAP_SECURITY_MODE_4) || (security_mode == GAP_SECURITY_MODE_2)){
3690         hci_stack->gap_security_mode = security_mode;
3691         return ERROR_CODE_SUCCESS;
3692     } else {
3693         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3694     }
3695 }
3696 
3697 gap_security_mode_t gap_get_security_mode(void){
3698     return hci_stack->gap_security_mode;
3699 }
3700 
3701 void gap_set_security_level(gap_security_level_t security_level){
3702     hci_stack->gap_security_level = security_level;
3703 }
3704 
3705 gap_security_level_t gap_get_security_level(void){
3706     if (hci_stack->gap_secure_connections_only_mode){
3707         return LEVEL_4;
3708     }
3709     return hci_stack->gap_security_level;
3710 }
3711 
3712 void gap_set_minimal_service_security_level(gap_security_level_t security_level){
3713     hci_stack->gap_minimal_service_security_level = security_level;
3714 }
3715 
3716 void gap_set_secure_connections_only_mode(bool enable){
3717     hci_stack->gap_secure_connections_only_mode = enable;
3718 }
3719 
3720 bool gap_get_secure_connections_only_mode(void){
3721     return hci_stack->gap_secure_connections_only_mode;
3722 }
3723 #endif
3724 
3725 #ifdef ENABLE_CLASSIC
3726 void gap_set_class_of_device(uint32_t class_of_device){
3727     hci_stack->class_of_device = class_of_device;
3728     hci_stack->gap_tasks |= GAP_TASK_SET_CLASS_OF_DEVICE;
3729     hci_run();
3730 }
3731 
3732 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3733     hci_stack->default_link_policy_settings = default_link_policy_settings;
3734     hci_stack->gap_tasks |= GAP_TASK_SET_DEFAULT_LINK_POLICY;
3735     hci_run();
3736 }
3737 
3738 void gap_set_allow_role_switch(bool allow_role_switch){
3739     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3740 }
3741 
3742 uint8_t hci_get_allow_role_switch(void){
3743     return  hci_stack->allow_role_switch;
3744 }
3745 
3746 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3747     hci_stack->link_supervision_timeout = link_supervision_timeout;
3748 }
3749 
3750 void hci_disable_l2cap_timeout_check(void){
3751     disable_l2cap_timeouts = 1;
3752 }
3753 #endif
3754 
3755 #ifndef HAVE_HOST_CONTROLLER_API
3756 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3757 void hci_set_bd_addr(bd_addr_t addr){
3758     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3759     hci_stack->custom_bd_addr_set = 1;
3760 }
3761 #endif
3762 
3763 // State-Module-Driver overview
3764 // state                    module  low-level
3765 // HCI_STATE_OFF             off      close
3766 // HCI_STATE_INITIALIZING,   on       open
3767 // HCI_STATE_WORKING,        on       open
3768 // HCI_STATE_HALTING,        on       open
3769 // HCI_STATE_SLEEPING,    off/sleep   close
3770 // HCI_STATE_FALLING_ASLEEP  on       open
3771 
3772 static int hci_power_control_on(void){
3773 
3774     // power on
3775     int err = 0;
3776     if (hci_stack->control && hci_stack->control->on){
3777         err = (*hci_stack->control->on)();
3778     }
3779     if (err){
3780         log_error( "POWER_ON failed");
3781         hci_emit_hci_open_failed();
3782         return err;
3783     }
3784 
3785     // int chipset driver
3786     if (hci_stack->chipset && hci_stack->chipset->init){
3787         hci_stack->chipset->init(hci_stack->config);
3788     }
3789 
3790     // init transport
3791     if (hci_stack->hci_transport->init){
3792         hci_stack->hci_transport->init(hci_stack->config);
3793     }
3794 
3795     // open transport
3796     err = hci_stack->hci_transport->open();
3797     if (err){
3798         log_error( "HCI_INIT failed, turning Bluetooth off again");
3799         if (hci_stack->control && hci_stack->control->off){
3800             (*hci_stack->control->off)();
3801         }
3802         hci_emit_hci_open_failed();
3803         return err;
3804     }
3805     return 0;
3806 }
3807 
3808 static void hci_power_control_off(void){
3809 
3810     log_info("hci_power_control_off");
3811 
3812     // close low-level device
3813     hci_stack->hci_transport->close();
3814 
3815     log_info("hci_power_control_off - hci_transport closed");
3816 
3817     // power off
3818     if (hci_stack->control && hci_stack->control->off){
3819         (*hci_stack->control->off)();
3820     }
3821 
3822     log_info("hci_power_control_off - control closed");
3823 
3824     hci_stack->state = HCI_STATE_OFF;
3825 }
3826 
3827 static void hci_power_control_sleep(void){
3828 
3829     log_info("hci_power_control_sleep");
3830 
3831 #if 0
3832     // don't close serial port during sleep
3833 
3834     // close low-level device
3835     hci_stack->hci_transport->close(hci_stack->config);
3836 #endif
3837 
3838     // sleep mode
3839     if (hci_stack->control && hci_stack->control->sleep){
3840         (*hci_stack->control->sleep)();
3841     }
3842 
3843     hci_stack->state = HCI_STATE_SLEEPING;
3844 }
3845 
3846 static int hci_power_control_wake(void){
3847 
3848     log_info("hci_power_control_wake");
3849 
3850     // wake on
3851     if (hci_stack->control && hci_stack->control->wake){
3852         (*hci_stack->control->wake)();
3853     }
3854 
3855 #if 0
3856     // open low-level device
3857     int err = hci_stack->hci_transport->open(hci_stack->config);
3858     if (err){
3859         log_error( "HCI_INIT failed, turning Bluetooth off again");
3860         if (hci_stack->control && hci_stack->control->off){
3861             (*hci_stack->control->off)();
3862         }
3863         hci_emit_hci_open_failed();
3864         return err;
3865     }
3866 #endif
3867 
3868     return 0;
3869 }
3870 
3871 static void hci_power_transition_to_initializing(void){
3872     // set up state machine
3873     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3874     hci_stack->hci_packet_buffer_reserved = false;
3875     hci_stack->state = HCI_STATE_INITIALIZING;
3876     hci_stack->substate = HCI_INIT_SEND_RESET;
3877 }
3878 
3879 // returns error
3880 static int hci_power_control_state_off(HCI_POWER_MODE power_mode){
3881     int err;
3882     switch (power_mode){
3883         case HCI_POWER_ON:
3884             err = hci_power_control_on();
3885             if (err != 0) {
3886                 log_error("hci_power_control_on() error %d", err);
3887                 return err;
3888             }
3889             hci_power_transition_to_initializing();
3890             break;
3891         case HCI_POWER_OFF:
3892             // do nothing
3893             break;
3894         case HCI_POWER_SLEEP:
3895             // do nothing (with SLEEP == OFF)
3896             break;
3897         default:
3898             btstack_assert(false);
3899             break;
3900     }
3901     return ERROR_CODE_SUCCESS;
3902 }
3903 
3904 static int hci_power_control_state_initializing(HCI_POWER_MODE power_mode){
3905     switch (power_mode){
3906         case HCI_POWER_ON:
3907             // do nothing
3908             break;
3909         case HCI_POWER_OFF:
3910             // no connections yet, just turn it off
3911             hci_power_control_off();
3912             break;
3913         case HCI_POWER_SLEEP:
3914             // no connections yet, just turn it off
3915             hci_power_control_sleep();
3916             break;
3917         default:
3918             btstack_assert(false);
3919             break;
3920     }
3921     return ERROR_CODE_SUCCESS;
3922 }
3923 
3924 static int hci_power_control_state_working(HCI_POWER_MODE power_mode) {
3925     switch (power_mode){
3926         case HCI_POWER_ON:
3927             // do nothing
3928             break;
3929         case HCI_POWER_OFF:
3930             // see hci_run
3931             hci_stack->state = HCI_STATE_HALTING;
3932             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3933             break;
3934         case HCI_POWER_SLEEP:
3935             // see hci_run
3936             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3937             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3938             break;
3939         default:
3940             btstack_assert(false);
3941             break;
3942     }
3943     return ERROR_CODE_SUCCESS;
3944 }
3945 
3946 static int hci_power_control_state_halting(HCI_POWER_MODE power_mode) {
3947     switch (power_mode){
3948         case HCI_POWER_ON:
3949             hci_power_transition_to_initializing();
3950             break;
3951         case HCI_POWER_OFF:
3952             // do nothing
3953             break;
3954         case HCI_POWER_SLEEP:
3955             // see hci_run
3956             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3957             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3958             break;
3959         default:
3960             btstack_assert(false);
3961             break;
3962     }
3963     return ERROR_CODE_SUCCESS;
3964 }
3965 
3966 static int hci_power_control_state_falling_asleep(HCI_POWER_MODE power_mode) {
3967     switch (power_mode){
3968         case HCI_POWER_ON:
3969             hci_power_transition_to_initializing();
3970             break;
3971         case HCI_POWER_OFF:
3972             // see hci_run
3973             hci_stack->state = HCI_STATE_HALTING;
3974             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3975             break;
3976         case HCI_POWER_SLEEP:
3977             // do nothing
3978             break;
3979         default:
3980             btstack_assert(false);
3981             break;
3982     }
3983     return ERROR_CODE_SUCCESS;
3984 }
3985 
3986 static int hci_power_control_state_sleeping(HCI_POWER_MODE power_mode) {
3987     int err;
3988     switch (power_mode){
3989         case HCI_POWER_ON:
3990             err = hci_power_control_wake();
3991             if (err) return err;
3992             hci_power_transition_to_initializing();
3993             break;
3994         case HCI_POWER_OFF:
3995             hci_stack->state = HCI_STATE_HALTING;
3996             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3997             break;
3998         case HCI_POWER_SLEEP:
3999             // do nothing
4000             break;
4001         default:
4002             btstack_assert(false);
4003             break;
4004     }
4005     return ERROR_CODE_SUCCESS;
4006 }
4007 
4008 int hci_power_control(HCI_POWER_MODE power_mode){
4009     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
4010     int err = 0;
4011     switch (hci_stack->state){
4012         case HCI_STATE_OFF:
4013             err = hci_power_control_state_off(power_mode);
4014             break;
4015         case HCI_STATE_INITIALIZING:
4016             err = hci_power_control_state_initializing(power_mode);
4017             break;
4018         case HCI_STATE_WORKING:
4019             err = hci_power_control_state_working(power_mode);
4020             break;
4021         case HCI_STATE_HALTING:
4022             err = hci_power_control_state_halting(power_mode);
4023             break;
4024         case HCI_STATE_FALLING_ASLEEP:
4025             err = hci_power_control_state_falling_asleep(power_mode);
4026             break;
4027         case HCI_STATE_SLEEPING:
4028             err = hci_power_control_state_sleeping(power_mode);
4029             break;
4030         default:
4031             btstack_assert(false);
4032             break;
4033     }
4034     if (err != 0){
4035         return err;
4036     }
4037 
4038     // create internal event
4039 	hci_emit_state();
4040 
4041 	// trigger next/first action
4042 	hci_run();
4043 
4044     return 0;
4045 }
4046 
4047 
4048 #ifdef ENABLE_CLASSIC
4049 
4050 static void hci_update_scan_enable(void){
4051     // 2 = page scan, 1 = inq scan
4052     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
4053     hci_stack->gap_tasks |= GAP_TASK_WRITE_SCAN_ENABLE;
4054     hci_run();
4055 }
4056 
4057 void gap_discoverable_control(uint8_t enable){
4058     if (enable) enable = 1; // normalize argument
4059 
4060     if (hci_stack->discoverable == enable){
4061         hci_emit_discoverable_enabled(hci_stack->discoverable);
4062         return;
4063     }
4064 
4065     hci_stack->discoverable = enable;
4066     hci_update_scan_enable();
4067 }
4068 
4069 void gap_connectable_control(uint8_t enable){
4070     if (enable) enable = 1; // normalize argument
4071 
4072     // don't emit event
4073     if (hci_stack->connectable == enable) return;
4074 
4075     hci_stack->connectable = enable;
4076     hci_update_scan_enable();
4077 }
4078 #endif
4079 
4080 void gap_local_bd_addr(bd_addr_t address_buffer){
4081     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
4082 }
4083 
4084 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4085 static void hci_host_num_completed_packets(void){
4086 
4087     // create packet manually as arrays are not supported and num_commands should not get reduced
4088     hci_reserve_packet_buffer();
4089     uint8_t * packet = hci_get_outgoing_packet_buffer();
4090 
4091     uint16_t size = 0;
4092     uint16_t num_handles = 0;
4093     packet[size++] = 0x35;
4094     packet[size++] = 0x0c;
4095     size++;  // skip param len
4096     size++;  // skip num handles
4097 
4098     // add { handle, packets } entries
4099     btstack_linked_item_t * it;
4100     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
4101         hci_connection_t * connection = (hci_connection_t *) it;
4102         if (connection->num_packets_completed){
4103             little_endian_store_16(packet, size, connection->con_handle);
4104             size += 2;
4105             little_endian_store_16(packet, size, connection->num_packets_completed);
4106             size += 2;
4107             //
4108             num_handles++;
4109             connection->num_packets_completed = 0;
4110         }
4111     }
4112 
4113     packet[2] = size - 3;
4114     packet[3] = num_handles;
4115 
4116     hci_stack->host_completed_packets = 0;
4117 
4118     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4119     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4120 
4121     // release packet buffer for synchronous transport implementations
4122     if (hci_transport_synchronous()){
4123         hci_release_packet_buffer();
4124         hci_emit_transport_packet_sent();
4125     }
4126 }
4127 #endif
4128 
4129 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
4130     UNUSED(ds);
4131     hci_stack->substate = HCI_HALTING_CLOSE;
4132     // allow packet handlers to defer final shutdown
4133     hci_emit_state();
4134     hci_run();
4135 }
4136 
4137 static bool hci_run_acl_fragments(void){
4138     if (hci_stack->acl_fragmentation_total_size > 0u) {
4139         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
4140         hci_connection_t *connection = hci_connection_for_handle(con_handle);
4141         if (connection) {
4142             if (hci_can_send_prepared_acl_packet_now(con_handle)){
4143                 hci_send_acl_packet_fragments(connection);
4144                 return true;
4145             }
4146         } else {
4147             // connection gone -> discard further fragments
4148             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
4149             hci_stack->acl_fragmentation_total_size = 0;
4150             hci_stack->acl_fragmentation_pos = 0;
4151         }
4152     }
4153     return false;
4154 }
4155 
4156 #ifdef ENABLE_CLASSIC
4157 static bool hci_run_general_gap_classic(void){
4158 
4159     // assert stack is working and classic is active
4160     if (hci_classic_supported() == false)      return false;
4161     if (hci_stack->state != HCI_STATE_WORKING) return false;
4162 
4163     // decline incoming connections
4164     if (hci_stack->decline_reason){
4165         uint8_t reason = hci_stack->decline_reason;
4166         hci_stack->decline_reason = 0;
4167         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
4168         return true;
4169     }
4170 
4171     if (hci_stack->gap_tasks != 0){
4172         hci_run_gap_tasks_classic();
4173         return true;
4174     }
4175 
4176     // start/stop inquiry
4177     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
4178         uint8_t duration = hci_stack->inquiry_state;
4179         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_ACTIVE;
4180         hci_send_cmd(&hci_inquiry, hci_stack->inquiry_lap, duration, 0);
4181         return true;
4182     }
4183     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
4184         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
4185         hci_send_cmd(&hci_inquiry_cancel);
4186         return true;
4187     }
4188     // remote name request
4189     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
4190         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
4191         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
4192                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
4193         return true;
4194     }
4195 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4196     // Local OOB data
4197     if (hci_stack->classic_read_local_oob_data){
4198         hci_stack->classic_read_local_oob_data = false;
4199         if (hci_stack->local_supported_commands[1] & 0x10u){
4200             hci_send_cmd(&hci_read_local_extended_oob_data);
4201         } else {
4202             hci_send_cmd(&hci_read_local_oob_data);
4203         }
4204     }
4205 #endif
4206     // pairing
4207     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
4208         uint8_t state = hci_stack->gap_pairing_state;
4209         uint8_t pin_code[16];
4210         switch (state){
4211             case GAP_PAIRING_STATE_SEND_PIN:
4212                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4213                 memset(pin_code, 0, 16);
4214                 memcpy(pin_code, hci_stack->gap_pairing_input.gap_pairing_pin, hci_stack->gap_pairing_pin_len);
4215                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_pin_len, pin_code);
4216                 break;
4217             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
4218                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4219                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
4220                 break;
4221             case GAP_PAIRING_STATE_SEND_PASSKEY:
4222                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4223                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
4224                 break;
4225             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
4226                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4227                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
4228                 break;
4229             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
4230                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4231                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
4232                 break;
4233             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
4234                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4235                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
4236                 break;
4237             default:
4238                 break;
4239         }
4240         return true;
4241     }
4242     return false;
4243 }
4244 #endif
4245 
4246 #ifdef ENABLE_BLE
4247 static bool hci_run_general_gap_le(void){
4248 
4249     // advertisements, active scanning, and creating connections requires random address to be set if using private address
4250 
4251     if (hci_stack->state != HCI_STATE_WORKING) return false;
4252     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
4253 
4254 
4255     // Phase 1: collect what to stop
4256 
4257     bool scanning_stop = false;
4258     bool connecting_stop = false;
4259     bool advertising_stop = false;
4260 
4261 #ifndef ENABLE_LE_CENTRAL
4262     UNUSED(scanning_stop);
4263     UNUSED(connecting_stop);
4264 #endif
4265 #ifndef ENABLE_LE_PERIPHERAL
4266     UNUSED(advertising_stop);
4267 #endif
4268 
4269     // check if own address changes
4270     bool random_address_change = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADDRESS) != 0;
4271 
4272     // check if whitelist needs modification
4273     bool whitelist_modification_pending = false;
4274     btstack_linked_list_iterator_t lit;
4275     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4276     while (btstack_linked_list_iterator_has_next(&lit)){
4277         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4278         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
4279             whitelist_modification_pending = true;
4280             break;
4281         }
4282     }
4283     // check if resolving list needs modification
4284     bool resolving_list_modification_pending = false;
4285 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4286     bool resolving_list_supported = (hci_stack->local_supported_commands[1] & (1 << 2)) != 0;
4287 	if (resolving_list_supported && hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_DONE){
4288         resolving_list_modification_pending = true;
4289     }
4290 #endif
4291 
4292 #ifdef ENABLE_LE_CENTRAL
4293     // scanning control
4294     if (hci_stack->le_scanning_active) {
4295         // stop if:
4296         // - parameter change required
4297         // - it's disabled
4298         // - whitelist change required but used for scanning
4299         // - resolving list modified
4300         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
4301         if ((hci_stack->le_scanning_param_update) ||
4302             !hci_stack->le_scanning_enabled ||
4303             scanning_uses_whitelist ||
4304             resolving_list_modification_pending){
4305 
4306             scanning_stop = true;
4307         }
4308     }
4309 #endif
4310 
4311 #ifdef ENABLE_LE_CENTRAL
4312     // connecting control
4313     bool connecting_with_whitelist;
4314     switch (hci_stack->le_connecting_state){
4315         case LE_CONNECTING_DIRECT:
4316         case LE_CONNECTING_WHITELIST:
4317             // stop connecting if:
4318             // - connecting uses white and whitelist modification pending
4319             // - if it got disabled
4320             // - resolving list modified
4321             connecting_with_whitelist = hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST;
4322             if ((connecting_with_whitelist && whitelist_modification_pending) ||
4323                 (hci_stack->le_connecting_request == LE_CONNECTING_IDLE) ||
4324                 resolving_list_modification_pending) {
4325 
4326                 connecting_stop = true;
4327             }
4328             break;
4329         default:
4330             break;
4331     }
4332 #endif
4333 
4334 #ifdef ENABLE_LE_PERIPHERAL
4335     // le advertisement control
4336     if (hci_stack->le_advertisements_active){
4337         // stop if:
4338         // - parameter change required
4339         // - random address used in advertising and changes
4340         // - it's disabled
4341         // - whitelist change required but used for advertisement filter policy
4342         // - resolving list modified
4343         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy != 0;
4344         bool advertising_uses_random_address = hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC;
4345         bool advertising_change    = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS)  != 0;
4346         if (advertising_change ||
4347             (advertising_uses_random_address && random_address_change) ||
4348             (hci_stack->le_advertisements_enabled_for_current_roles == 0) ||
4349             (advertising_uses_whitelist && whitelist_modification_pending) ||
4350             resolving_list_modification_pending) {
4351 
4352             advertising_stop = true;
4353         }
4354     }
4355 #endif
4356 
4357 
4358     // Phase 2: stop everything that should be off during modifications
4359 
4360 #ifdef ENABLE_LE_CENTRAL
4361     if (scanning_stop){
4362         hci_stack->le_scanning_active = false;
4363         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
4364         return true;
4365     }
4366 #endif
4367 
4368 #ifdef ENABLE_LE_CENTRAL
4369     if (connecting_stop){
4370         hci_send_cmd(&hci_le_create_connection_cancel);
4371         return true;
4372     }
4373 #endif
4374 
4375 #ifdef ENABLE_LE_PERIPHERAL
4376     if (advertising_stop){
4377         hci_stack->le_advertisements_active = false;
4378         hci_send_cmd(&hci_le_set_advertise_enable, 0);
4379         return true;
4380     }
4381 #endif
4382 
4383     // Phase 3: modify
4384 
4385     if (random_address_change){
4386         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADDRESS;
4387         hci_send_cmd(&hci_le_set_random_address, hci_stack->le_random_address);
4388         return true;
4389     }
4390 
4391 #ifdef ENABLE_LE_CENTRAL
4392     if (hci_stack->le_scanning_param_update){
4393         hci_stack->le_scanning_param_update = false;
4394         hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
4395                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
4396         return true;
4397     }
4398 #endif
4399 
4400 #ifdef ENABLE_LE_PERIPHERAL
4401     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
4402         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
4403         hci_stack->le_advertisements_own_addr_type = hci_stack->le_own_addr_type;
4404         hci_send_cmd(&hci_le_set_advertising_parameters,
4405                      hci_stack->le_advertisements_interval_min,
4406                      hci_stack->le_advertisements_interval_max,
4407                      hci_stack->le_advertisements_type,
4408                      hci_stack->le_advertisements_own_addr_type,
4409                      hci_stack->le_advertisements_direct_address_type,
4410                      hci_stack->le_advertisements_direct_address,
4411                      hci_stack->le_advertisements_channel_map,
4412                      hci_stack->le_advertisements_filter_policy);
4413         return true;
4414     }
4415     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
4416         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
4417         uint8_t adv_data_clean[31];
4418         memset(adv_data_clean, 0, sizeof(adv_data_clean));
4419         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
4420                      hci_stack->le_advertisements_data_len);
4421         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
4422         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
4423         return true;
4424     }
4425     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
4426         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
4427         uint8_t scan_data_clean[31];
4428         memset(scan_data_clean, 0, sizeof(scan_data_clean));
4429         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
4430                      hci_stack->le_scan_response_data_len);
4431         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
4432         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
4433         return true;
4434     }
4435 #endif
4436 
4437 
4438 #ifdef ENABLE_LE_CENTRAL
4439     // if connect with whitelist was active and is not cancelled yet, wait until next time
4440     if (hci_stack->le_connecting_state == LE_CONNECTING_CANCEL) return false;
4441 #endif
4442 
4443     // LE Whitelist Management
4444     if (whitelist_modification_pending){
4445         // add/remove entries
4446         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4447         while (btstack_linked_list_iterator_has_next(&lit)){
4448             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4449 			if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
4450 				entry->state &= ~LE_WHITELIST_REMOVE_FROM_CONTROLLER;
4451 				hci_send_cmd(&hci_le_remove_device_from_white_list, entry->address_type, entry->address);
4452 				return true;
4453 			}
4454             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
4455 				entry->state &= ~LE_WHITELIST_ADD_TO_CONTROLLER;
4456                 entry->state |= LE_WHITELIST_ON_CONTROLLER;
4457                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
4458                 return true;
4459             }
4460             if ((entry->state & LE_WHITELIST_ON_CONTROLLER) == 0){
4461 				btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4462 				btstack_memory_whitelist_entry_free(entry);
4463             }
4464         }
4465     }
4466 
4467 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4468     // LE Resolving List Management
4469     if (resolving_list_supported) {
4470 		uint16_t i;
4471 		switch (hci_stack->le_resolving_list_state) {
4472 			case LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION:
4473 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
4474 				hci_send_cmd(&hci_le_set_address_resolution_enabled, 1);
4475 				return true;
4476 			case LE_RESOLVING_LIST_READ_SIZE:
4477 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_SEND_CLEAR;
4478 				hci_send_cmd(&hci_le_read_resolving_list_size);
4479 				return true;
4480 			case LE_RESOLVING_LIST_SEND_CLEAR:
4481 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
4482 				(void) memset(hci_stack->le_resolving_list_add_entries, 0xff,
4483 							  sizeof(hci_stack->le_resolving_list_add_entries));
4484 				(void) memset(hci_stack->le_resolving_list_remove_entries, 0,
4485 							  sizeof(hci_stack->le_resolving_list_remove_entries));
4486 				hci_send_cmd(&hci_le_clear_resolving_list);
4487 				return true;
4488 			case LE_RESOLVING_LIST_REMOVE_ENTRIES:
4489 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4490 					uint8_t offset = i >> 3;
4491 					uint8_t mask = 1 << (i & 7);
4492 					if ((hci_stack->le_resolving_list_remove_entries[offset] & mask) == 0) continue;
4493 					hci_stack->le_resolving_list_remove_entries[offset] &= ~mask;
4494 					bd_addr_t peer_identity_addreses;
4495 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4496 					sm_key_t peer_irk;
4497 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4498 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4499 
4500 #ifdef ENABLE_LE_WHITELIST_TOUCH_AFTER_RESOLVING_LIST_UPDATE
4501 					// trigger whitelist entry 'update' (work around for controller bug)
4502 					btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4503 					while (btstack_linked_list_iterator_has_next(&lit)) {
4504 						whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&lit);
4505 						if (entry->address_type != peer_identity_addr_type) continue;
4506 						if (memcmp(entry->address, peer_identity_addreses, 6) != 0) continue;
4507 						log_info("trigger whitelist update %s", bd_addr_to_str(peer_identity_addreses));
4508 						entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER;
4509 					}
4510 #endif
4511 
4512 					hci_send_cmd(&hci_le_remove_device_from_resolving_list, peer_identity_addr_type,
4513 								 peer_identity_addreses);
4514 					return true;
4515 				}
4516 
4517 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_ADD_ENTRIES;
4518 
4519 				/* fall through */
4520 
4521 			case LE_RESOLVING_LIST_ADD_ENTRIES:
4522 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4523 					uint8_t offset = i >> 3;
4524 					uint8_t mask = 1 << (i & 7);
4525 					if ((hci_stack->le_resolving_list_add_entries[offset] & mask) == 0) continue;
4526 					hci_stack->le_resolving_list_add_entries[offset] &= ~mask;
4527 					bd_addr_t peer_identity_addreses;
4528 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4529 					sm_key_t peer_irk;
4530 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4531 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4532 					const uint8_t *local_irk = gap_get_persistent_irk();
4533 					// command uses format specifier 'P' that stores 16-byte value without flip
4534 					uint8_t local_irk_flipped[16];
4535 					uint8_t peer_irk_flipped[16];
4536 					reverse_128(local_irk, local_irk_flipped);
4537 					reverse_128(peer_irk, peer_irk_flipped);
4538 					hci_send_cmd(&hci_le_add_device_to_resolving_list, peer_identity_addr_type, peer_identity_addreses,
4539 								 peer_irk_flipped, local_irk_flipped);
4540 					return true;
4541 				}
4542 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4543 				break;
4544 
4545 			default:
4546 				break;
4547 		}
4548 	}
4549     hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4550 #endif
4551 
4552     // Phase 4: restore state
4553 
4554 #ifdef ENABLE_LE_CENTRAL
4555     // re-start scanning
4556     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
4557         hci_stack->le_scanning_active = true;
4558         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
4559         return true;
4560     }
4561 #endif
4562 
4563 #ifdef ENABLE_LE_CENTRAL
4564     // re-start connecting
4565     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
4566         bd_addr_t null_addr;
4567         memset(null_addr, 0, 6);
4568         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4569         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4570         hci_send_cmd(&hci_le_create_connection,
4571                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
4572                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
4573                      1,         // use whitelist
4574                      0,         // peer address type
4575                      null_addr, // peer bd addr
4576                      hci_stack->le_connection_own_addr_type,   // our addr type:
4577                      hci_stack->le_connection_interval_min,    // conn interval min
4578                      hci_stack->le_connection_interval_max,    // conn interval max
4579                      hci_stack->le_connection_latency,         // conn latency
4580                      hci_stack->le_supervision_timeout,        // conn latency
4581                      hci_stack->le_minimum_ce_length,          // min ce length
4582                      hci_stack->le_maximum_ce_length           // max ce length
4583         );
4584         return true;
4585     }
4586 #endif
4587 
4588 #ifdef ENABLE_LE_PERIPHERAL
4589     // re-start advertising
4590     if (hci_stack->le_advertisements_enabled_for_current_roles && !hci_stack->le_advertisements_active){
4591         // check if advertisements should be enabled given
4592         hci_stack->le_advertisements_active = true;
4593         hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, hci_stack->le_advertisements_own_address);
4594         hci_send_cmd(&hci_le_set_advertise_enable, 1);
4595         return true;
4596     }
4597 #endif
4598 
4599     return false;
4600 }
4601 #endif
4602 
4603 static bool hci_run_general_pending_commands(void){
4604     btstack_linked_item_t * it;
4605     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4606         hci_connection_t * connection = (hci_connection_t *) it;
4607 
4608         switch(connection->state){
4609             case SEND_CREATE_CONNECTION:
4610                 switch(connection->address_type){
4611 #ifdef ENABLE_CLASSIC
4612                     case BD_ADDR_TYPE_ACL:
4613                         log_info("sending hci_create_connection");
4614                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
4615                         break;
4616 #endif
4617                     default:
4618 #ifdef ENABLE_BLE
4619 #ifdef ENABLE_LE_CENTRAL
4620                         log_info("sending hci_le_create_connection");
4621                         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4622                         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4623                         hci_send_cmd(&hci_le_create_connection,
4624                                      hci_stack->le_connection_scan_interval,    // conn scan interval
4625                                      hci_stack->le_connection_scan_window,      // conn scan windows
4626                                      0,         // don't use whitelist
4627                                      connection->address_type, // peer address type
4628                                      connection->address,      // peer bd addr
4629                                      hci_stack->le_connection_own_addr_type,   // our addr type:
4630                                      hci_stack->le_connection_interval_min,    // conn interval min
4631                                      hci_stack->le_connection_interval_max,    // conn interval max
4632                                      hci_stack->le_connection_latency,         // conn latency
4633                                      hci_stack->le_supervision_timeout,        // conn latency
4634                                      hci_stack->le_minimum_ce_length,          // min ce length
4635                                      hci_stack->le_maximum_ce_length          // max ce length
4636                         );
4637                         connection->state = SENT_CREATE_CONNECTION;
4638 #endif
4639 #endif
4640                         break;
4641                 }
4642                 return true;
4643 
4644 #ifdef ENABLE_CLASSIC
4645             case RECEIVED_CONNECTION_REQUEST:
4646                 connection->role  = HCI_ROLE_SLAVE;
4647                 if (connection->address_type == BD_ADDR_TYPE_ACL){
4648                     log_info("sending hci_accept_connection_request");
4649                     connection->state = ACCEPTED_CONNECTION_REQUEST;
4650                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
4651                 }
4652                 return true;
4653 #endif
4654 
4655 #ifdef ENABLE_BLE
4656 #ifdef ENABLE_LE_CENTRAL
4657             case SEND_CANCEL_CONNECTION:
4658                 connection->state = SENT_CANCEL_CONNECTION;
4659                 hci_send_cmd(&hci_le_create_connection_cancel);
4660                 return true;
4661 #endif
4662 #endif
4663             case SEND_DISCONNECT:
4664                 connection->state = SENT_DISCONNECT;
4665                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4666                 return true;
4667 
4668             default:
4669                 break;
4670         }
4671 
4672         // no further commands if connection is about to get shut down
4673         if (connection->state == SENT_DISCONNECT) continue;
4674 
4675         if (connection->authentication_flags & AUTH_FLAG_READ_RSSI){
4676             connectionClearAuthenticationFlags(connection, AUTH_FLAG_READ_RSSI);
4677             hci_send_cmd(&hci_read_rssi, connection->con_handle);
4678             return true;
4679         }
4680 
4681 #ifdef ENABLE_CLASSIC
4682 
4683         if (connection->authentication_flags & AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT){
4684             connectionClearAuthenticationFlags(connection, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
4685             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
4686             return true;
4687         }
4688 
4689         // Handling link key request requires remote supported features
4690         if (((connection->authentication_flags & AUTH_FLAG_HANDLE_LINK_KEY_REQUEST) != 0)){
4691             log_info("responding to link key request, have link key db: %u", hci_stack->link_key_db != NULL);
4692             connectionClearAuthenticationFlags(connection, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
4693 
4694             bool have_link_key = connection->link_key_type != INVALID_LINK_KEY;
4695             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(connection->link_key_type) >= connection->requested_security_level);
4696             if (have_link_key && security_level_sufficient){
4697                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &connection->link_key);
4698             } else {
4699                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
4700             }
4701             return true;
4702         }
4703 
4704         if (connection->authentication_flags & AUTH_FLAG_DENY_PIN_CODE_REQUEST){
4705             log_info("denying to pin request");
4706             connectionClearAuthenticationFlags(connection, AUTH_FLAG_DENY_PIN_CODE_REQUEST);
4707             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
4708             return true;
4709         }
4710 
4711         // security assessment requires remote features
4712         if ((connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST) != 0){
4713             connectionClearAuthenticationFlags(connection, AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
4714             hci_ssp_assess_security_on_io_cap_request(connection);
4715             // 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
4716         }
4717 
4718         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY){
4719             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
4720             // set authentication requirements:
4721             // - MITM = ssp_authentication_requirement (USER) | requested_security_level (dynamic)
4722             // - BONDING MODE: dedicated if requested, bondable otherwise. Drop bondable if not set for remote
4723             uint8_t authreq = hci_stack->ssp_authentication_requirement & 1;
4724             if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
4725                 authreq |= 1;
4726             }
4727             bool bonding = hci_stack->bondable;
4728             if (connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
4729                 // if we have received IO Cap Response, we're in responder role
4730                 bool remote_bonding = connection->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4731                 if (bonding && !remote_bonding){
4732                     log_info("Remote not bonding, dropping local flag");
4733                     bonding = false;
4734                 }
4735             }
4736             if (bonding){
4737                 if (connection->bonding_flags & BONDING_DEDICATED){
4738                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4739                 } else {
4740                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
4741                 }
4742             }
4743             uint8_t have_oob_data = 0;
4744 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4745             if (connection->classic_oob_c_192 != NULL){
4746                     have_oob_data |= 1;
4747             }
4748             if (connection->classic_oob_c_256 != NULL){
4749                 have_oob_data |= 2;
4750             }
4751 #endif
4752             hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, have_oob_data, authreq);
4753             return true;
4754         }
4755 
4756         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY) {
4757             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
4758             hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
4759             return true;
4760         }
4761 
4762 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4763         if (connection->authentication_flags & AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY){
4764             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
4765             const uint8_t zero[16] = { 0 };
4766             const uint8_t * r_192 = zero;
4767             const uint8_t * c_192 = zero;
4768             const uint8_t * r_256 = zero;
4769             const uint8_t * c_256 = zero;
4770             // verify P-256 OOB
4771             if ((connection->classic_oob_c_256 != NULL) && ((hci_stack->local_supported_commands[1] & 0x08u) != 0)) {
4772                 c_256 = connection->classic_oob_c_256;
4773                 if (connection->classic_oob_r_256 != NULL) {
4774                     r_256 = connection->classic_oob_r_256;
4775                 }
4776             }
4777             // verify P-192 OOB
4778             if ((connection->classic_oob_c_192 != NULL)) {
4779                 c_192 = connection->classic_oob_c_192;
4780                 if (connection->classic_oob_r_192 != NULL) {
4781                     r_192 = connection->classic_oob_r_192;
4782                 }
4783             }
4784 
4785             // assess security
4786             bool need_level_4 = hci_stack->gap_secure_connections_only_mode || (connection->requested_security_level == LEVEL_4);
4787             bool can_reach_level_4 = hci_remote_sc_enabled(connection) && (c_256 != NULL);
4788             if (need_level_4 && !can_reach_level_4){
4789                 log_info("Level 4 required, but not possible -> abort");
4790                 hci_pairing_complete(connection, ERROR_CODE_INSUFFICIENT_SECURITY);
4791                 // send oob negative reply
4792                 c_256 = NULL;
4793                 c_192 = NULL;
4794             }
4795 
4796             // Reply
4797             if (c_256 != zero) {
4798                 hci_send_cmd(&hci_remote_oob_extended_data_request_reply, &connection->address, c_192, r_192, c_256, r_256);
4799             } else if (c_192 != zero){
4800                 hci_send_cmd(&hci_remote_oob_data_request_reply, &connection->address, c_192, r_192);
4801             } else {
4802                 hci_stack->classic_oob_con_handle = connection->con_handle;
4803                 hci_send_cmd(&hci_remote_oob_data_request_negative_reply, &connection->address);
4804             }
4805             return true;
4806         }
4807 #endif
4808 
4809         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_REPLY){
4810             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
4811             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
4812             return true;
4813         }
4814 
4815         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY){
4816             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
4817             hci_send_cmd(&hci_user_confirmation_request_negative_reply, &connection->address);
4818             return true;
4819         }
4820 
4821         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_PASSKEY_REPLY){
4822             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
4823             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
4824             return true;
4825         }
4826 
4827         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
4828             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
4829             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
4830             connection->state = SENT_DISCONNECT;
4831             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4832             return true;
4833         }
4834 
4835         if ((connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST) && ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0)){
4836             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
4837             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
4838             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
4839             return true;
4840         }
4841 
4842         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
4843             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
4844             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
4845             return true;
4846         }
4847 
4848         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
4849             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
4850             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
4851             return true;
4852         }
4853 
4854         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
4855             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
4856             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
4857             return true;
4858         }
4859 
4860         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
4861             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
4862             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
4863             return true;
4864         }
4865 
4866         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
4867             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
4868             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
4869             return true;
4870         }
4871 #endif
4872 
4873         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
4874             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
4875 #ifdef ENABLE_CLASSIC
4876             hci_pairing_complete(connection, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_SECURITY_REASONS);
4877 #endif
4878             if (connection->state != SENT_DISCONNECT){
4879                 connection->state = SENT_DISCONNECT;
4880                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4881                 return true;
4882             }
4883         }
4884 
4885 #ifdef ENABLE_CLASSIC
4886         uint16_t sniff_min_interval;
4887         switch (connection->sniff_min_interval){
4888             case 0:
4889                 break;
4890             case 0xffff:
4891                 connection->sniff_min_interval = 0;
4892                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
4893                 return true;
4894             default:
4895                 sniff_min_interval = connection->sniff_min_interval;
4896                 connection->sniff_min_interval = 0;
4897                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
4898                 return true;
4899         }
4900 
4901         if (connection->sniff_subrating_max_latency != 0xffff){
4902             uint16_t max_latency = connection->sniff_subrating_max_latency;
4903             connection->sniff_subrating_max_latency = 0;
4904             hci_send_cmd(&hci_sniff_subrating, connection->con_handle, max_latency, connection->sniff_subrating_min_remote_timeout, connection->sniff_subrating_min_local_timeout);
4905             return true;
4906         }
4907 
4908         if (connection->qos_service_type != HCI_SERVICE_TYPE_INVALID){
4909             uint8_t service_type = (uint8_t) connection->qos_service_type;
4910             connection->qos_service_type = HCI_SERVICE_TYPE_INVALID;
4911             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);
4912             return true;
4913         }
4914 
4915         if (connection->request_role != HCI_ROLE_INVALID){
4916             hci_role_t role = connection->request_role;
4917             connection->request_role = HCI_ROLE_INVALID;
4918             hci_send_cmd(&hci_switch_role_command, connection->address, role);
4919             return true;
4920         }
4921 #endif
4922 
4923 #ifdef ENABLE_BLE
4924         switch (connection->le_con_parameter_update_state){
4925             // response to L2CAP CON PARAMETER UPDATE REQUEST
4926             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
4927                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4928                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
4929                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4930                              0x0000, 0xffff);
4931                 return true;
4932             case CON_PARAMETER_UPDATE_REPLY:
4933                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4934                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
4935                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4936                              0x0000, 0xffff);
4937                 return true;
4938             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
4939                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4940                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
4941                 return true;
4942             default:
4943                 break;
4944         }
4945         if (connection->le_phy_update_all_phys != 0xffu){
4946             uint8_t all_phys = connection->le_phy_update_all_phys;
4947             connection->le_phy_update_all_phys = 0xff;
4948             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);
4949             return true;
4950         }
4951 #endif
4952     }
4953     return false;
4954 }
4955 
4956 static void hci_run(void){
4957 
4958     bool done;
4959 
4960     // send continuation fragments first, as they block the prepared packet buffer
4961     done = hci_run_acl_fragments();
4962     if (done) return;
4963 
4964 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4965     // send host num completed packets next as they don't require num_cmd_packets > 0
4966     if (!hci_can_send_comand_packet_transport()) return;
4967     if (hci_stack->host_completed_packets){
4968         hci_host_num_completed_packets();
4969         return;
4970     }
4971 #endif
4972 
4973     if (!hci_can_send_command_packet_now()) return;
4974 
4975     // global/non-connection oriented commands
4976 
4977 
4978 #ifdef ENABLE_CLASSIC
4979     // general gap classic
4980     done = hci_run_general_gap_classic();
4981     if (done) return;
4982 #endif
4983 
4984 #ifdef ENABLE_BLE
4985     // general gap le
4986     done = hci_run_general_gap_le();
4987     if (done) return;
4988 #endif
4989 
4990     // send pending HCI commands
4991     done = hci_run_general_pending_commands();
4992     if (done) return;
4993 
4994     // stack state sub statemachines
4995     hci_connection_t * connection;
4996     switch (hci_stack->state){
4997         case HCI_STATE_INITIALIZING:
4998             hci_initializing_run();
4999             break;
5000 
5001         case HCI_STATE_HALTING:
5002 
5003             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
5004             switch (hci_stack->substate){
5005                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
5006                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
5007 
5008 #ifdef ENABLE_BLE
5009 #ifdef ENABLE_LE_CENTRAL
5010                     hci_whitelist_free();
5011 #endif
5012 #endif
5013                     // close all open connections
5014                     connection =  (hci_connection_t *) hci_stack->connections;
5015                     if (connection){
5016                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
5017                         if (!hci_can_send_command_packet_now()) return;
5018 
5019                         // check state
5020                         if (connection->state == SENT_DISCONNECT) return;
5021                         connection->state = SENT_DISCONNECT;
5022 
5023                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
5024 
5025                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
5026                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
5027 
5028                         // ... which would be ignored anyway as we shutdown (free) the connection now
5029                         hci_shutdown_connection(connection);
5030 
5031                         // finally, send the disconnect command
5032                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5033                         return;
5034                     }
5035 
5036                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
5037                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
5038                         log_info("HCI_STATE_HALTING: wait 50 ms");
5039                         hci_stack->substate = HCI_HALTING_W4_TIMER;
5040                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
5041                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
5042                         btstack_run_loop_add_timer(&hci_stack->timeout);
5043                         break;
5044                     }
5045 
5046                     /* fall through */
5047 
5048                 case HCI_HALTING_CLOSE:
5049                     log_info("HCI_STATE_HALTING, calling off");
5050 
5051                     // switch mode
5052                     hci_power_control_off();
5053 
5054                     log_info("HCI_STATE_HALTING, emitting state");
5055                     hci_emit_state();
5056                     log_info("HCI_STATE_HALTING, done");
5057                     break;
5058 
5059                 case HCI_HALTING_W4_TIMER:
5060                     // keep waiting
5061 
5062                     break;
5063                 default:
5064                     break;
5065             }
5066 
5067             break;
5068 
5069         case HCI_STATE_FALLING_ASLEEP:
5070             switch(hci_stack->substate) {
5071                 case HCI_FALLING_ASLEEP_DISCONNECT:
5072                     log_info("HCI_STATE_FALLING_ASLEEP");
5073                     // close all open connections
5074                     connection =  (hci_connection_t *) hci_stack->connections;
5075                     if (connection){
5076 
5077                         // send disconnect
5078                         if (!hci_can_send_command_packet_now()) return;
5079 
5080                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
5081                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5082 
5083                         // send disconnected event right away - causes higher layer connections to get closed, too.
5084                         hci_shutdown_connection(connection);
5085                         return;
5086                     }
5087 
5088                     if (hci_classic_supported()){
5089                         // disable page and inquiry scan
5090                         if (!hci_can_send_command_packet_now()) return;
5091 
5092                         log_info("HCI_STATE_HALTING, disabling inq scans");
5093                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
5094 
5095                         // continue in next sub state
5096                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
5097                         break;
5098                     }
5099 
5100                     /* fall through */
5101 
5102                 case HCI_FALLING_ASLEEP_COMPLETE:
5103                     log_info("HCI_STATE_HALTING, calling sleep");
5104                     // switch mode
5105                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
5106                     hci_emit_state();
5107                     break;
5108 
5109                 default:
5110                     break;
5111             }
5112             break;
5113 
5114         default:
5115             break;
5116     }
5117 }
5118 
5119 uint8_t hci_send_cmd_packet(uint8_t *packet, int size){
5120     // house-keeping
5121 
5122 #ifdef ENABLE_CLASSIC
5123     bd_addr_t addr;
5124     hci_connection_t * conn;
5125 #endif
5126 #ifdef ENABLE_LE_CENTRAL
5127     uint8_t initiator_filter_policy;
5128 #endif
5129 
5130     uint16_t opcode = little_endian_read_16(packet, 0);
5131     switch (opcode) {
5132         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
5133             hci_stack->loopback_mode = packet[3];
5134             break;
5135 
5136 #ifdef ENABLE_CLASSIC
5137         case HCI_OPCODE_HCI_CREATE_CONNECTION:
5138             reverse_bd_addr(&packet[3], addr);
5139             log_info("Create_connection to %s", bd_addr_to_str(addr));
5140 
5141             // CVE-2020-26555: reject outgoing connection to device with same BD ADDR
5142             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0) {
5143                 hci_emit_connection_complete(addr, 0, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR);
5144                 return ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
5145             }
5146 
5147             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5148             if (!conn) {
5149                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5150                 if (!conn) {
5151                     // notify client that alloc failed
5152                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5153                     return BTSTACK_MEMORY_ALLOC_FAILED; // packet not sent to controller
5154                 }
5155                 conn->state = SEND_CREATE_CONNECTION;
5156                 conn->role  = HCI_ROLE_MASTER;
5157             }
5158 
5159             conn->con_handle = HCI_CON_HANDLE_INVALID;
5160             conn->role = HCI_ROLE_INVALID;
5161 
5162             log_info("conn state %u", conn->state);
5163             // TODO: L2CAP should not send create connection command, instead a (new) gap function should be used
5164             switch (conn->state) {
5165                 // if connection active exists
5166                 case OPEN:
5167                     // and OPEN, emit connection complete command
5168                     hci_emit_connection_complete(addr, conn->con_handle, ERROR_CODE_SUCCESS);
5169                     // packet not sent to controller
5170                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5171                 case RECEIVED_DISCONNECTION_COMPLETE:
5172                     // create connection triggered in disconnect complete event, let's do it now
5173                     break;
5174                 case SEND_CREATE_CONNECTION:
5175                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
5176                     break;
5177                 default:
5178                     // otherwise, just ignore as it is already in the open process
5179                     // packet not sent to controller
5180                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5181             }
5182             conn->state = SENT_CREATE_CONNECTION;
5183 
5184             // track outgoing connection
5185             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
5186             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
5187             break;
5188 
5189 #if defined (ENABLE_SCO_OVER_HCI) || defined (HAVE_SCO_TRANSPORT)
5190         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
5191             // setup_synchronous_connection? Voice setting at offset 22
5192             // TODO: compare to current setting if sco connection already active
5193             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
5194             break;
5195         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
5196             // accept_synchronous_connection? Voice setting at offset 18
5197             // TODO: compare to current setting if sco connection already active
5198             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
5199             break;
5200 #endif
5201 #endif
5202 
5203 #ifdef ENABLE_BLE
5204 #ifdef ENABLE_LE_CENTRAL
5205         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
5206             // white list used?
5207             initiator_filter_policy = packet[7];
5208             switch (initiator_filter_policy) {
5209                 case 0:
5210                     // whitelist not used
5211                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
5212                     break;
5213                 case 1:
5214                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
5215                     break;
5216                 default:
5217                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
5218                     break;
5219             }
5220             // track outgoing connection
5221             hci_stack->outgoing_addr_type = (bd_addr_type_t) packet[8]; // peer addres type
5222             reverse_bd_addr( &packet[9], hci_stack->outgoing_addr); // peer address
5223             break;
5224         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
5225             hci_stack->le_connecting_state = LE_CONNECTING_CANCEL;
5226             break;
5227 #endif
5228 #endif
5229         default:
5230             break;
5231     }
5232 
5233     hci_stack->num_cmd_packets--;
5234 
5235     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
5236     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
5237     if (err != 0){
5238         return ERROR_CODE_HARDWARE_FAILURE;
5239     }
5240     return ERROR_CODE_SUCCESS;
5241 }
5242 
5243 // disconnect because of security block
5244 void hci_disconnect_security_block(hci_con_handle_t con_handle){
5245     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5246     if (!connection) return;
5247     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
5248 }
5249 
5250 
5251 // Configure Secure Simple Pairing
5252 
5253 #ifdef ENABLE_CLASSIC
5254 
5255 // enable will enable SSP during init
5256 void gap_ssp_set_enable(int enable){
5257     hci_stack->ssp_enable = enable;
5258 }
5259 
5260 static int hci_local_ssp_activated(void){
5261     return gap_ssp_supported() && hci_stack->ssp_enable;
5262 }
5263 
5264 // if set, BTstack will respond to io capability request using authentication requirement
5265 void gap_ssp_set_io_capability(int io_capability){
5266     hci_stack->ssp_io_capability = io_capability;
5267 }
5268 void gap_ssp_set_authentication_requirement(int authentication_requirement){
5269     hci_stack->ssp_authentication_requirement = authentication_requirement;
5270 }
5271 
5272 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
5273 void gap_ssp_set_auto_accept(int auto_accept){
5274     hci_stack->ssp_auto_accept = auto_accept;
5275 }
5276 
5277 void gap_secure_connections_enable(bool enable){
5278     hci_stack->secure_connections_enable = enable;
5279 }
5280 
5281 #endif
5282 
5283 // va_list part of hci_send_cmd
5284 uint8_t hci_send_cmd_va_arg(const hci_cmd_t * cmd, va_list argptr){
5285     if (!hci_can_send_command_packet_now()){
5286         log_error("hci_send_cmd called but cannot send packet now");
5287         return ERROR_CODE_COMMAND_DISALLOWED;
5288     }
5289 
5290     // for HCI INITIALIZATION
5291     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
5292     hci_stack->last_cmd_opcode = cmd->opcode;
5293 
5294     hci_reserve_packet_buffer();
5295     uint8_t * packet = hci_stack->hci_packet_buffer;
5296     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
5297     uint8_t status = hci_send_cmd_packet(packet, size);
5298 
5299     // release packet buffer on error or for synchronous transport implementations
5300     if ((status != ERROR_CODE_SUCCESS) || hci_transport_synchronous()){
5301         hci_release_packet_buffer();
5302         hci_emit_transport_packet_sent();
5303     }
5304 
5305     return status;
5306 }
5307 
5308 /**
5309  * pre: numcmds >= 0 - it's allowed to send a command to the controller
5310  */
5311 uint8_t hci_send_cmd(const hci_cmd_t * cmd, ...){
5312     va_list argptr;
5313     va_start(argptr, cmd);
5314     uint8_t status = hci_send_cmd_va_arg(cmd, argptr);
5315     va_end(argptr);
5316     return status;
5317 }
5318 
5319 // Create various non-HCI events.
5320 // TODO: generalize, use table similar to hci_create_command
5321 
5322 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
5323     // dump packet
5324     if (dump) {
5325         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
5326     }
5327 
5328     // dispatch to all event handlers
5329     btstack_linked_list_iterator_t it;
5330     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
5331     while (btstack_linked_list_iterator_has_next(&it)){
5332         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
5333         entry->callback(HCI_EVENT_PACKET, 0, event, size);
5334     }
5335 }
5336 
5337 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
5338     if (!hci_stack->acl_packet_handler) return;
5339     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
5340 }
5341 
5342 #ifdef ENABLE_CLASSIC
5343 static void hci_notify_if_sco_can_send_now(void){
5344     // notify SCO sender if waiting
5345     if (!hci_stack->sco_waiting_for_can_send_now) return;
5346     if (hci_can_send_sco_packet_now()){
5347         hci_stack->sco_waiting_for_can_send_now = 0;
5348         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
5349         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
5350         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
5351     }
5352 }
5353 
5354 // parsing end emitting has been merged to reduce code size
5355 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
5356     uint8_t event[28+GAP_INQUIRY_MAX_NAME_LEN];
5357 
5358     uint8_t * eir_data;
5359     ad_context_t context;
5360     const uint8_t * name;
5361     uint8_t         name_len;
5362 
5363     if (size < 3) return;
5364 
5365     int event_type = hci_event_packet_get_type(packet);
5366     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
5367     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
5368 
5369     switch (event_type){
5370         case HCI_EVENT_INQUIRY_RESULT:
5371         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5372             if (size != (3 + (num_responses * 14))) return;
5373             break;
5374         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5375             if (size != 257) return;
5376             if (num_responses != 1) return;
5377             break;
5378         default:
5379             return;
5380     }
5381 
5382     // event[1] is set at the end
5383     int i;
5384     for (i=0; i<num_responses;i++){
5385         memset(event, 0, sizeof(event));
5386         event[0] = GAP_EVENT_INQUIRY_RESULT;
5387         uint8_t event_size = 27;    // if name is not set by EIR
5388 
5389         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
5390         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
5391         (void)memcpy(&event[9],
5392                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
5393                      3); // class of device
5394         (void)memcpy(&event[12],
5395                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
5396                      2); // clock offset
5397 
5398         switch (event_type){
5399             case HCI_EVENT_INQUIRY_RESULT:
5400                 // 14,15,16,17 = 0, size 18
5401                 break;
5402             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5403                 event[14] = 1;
5404                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5405                 // 16,17 = 0, size 18
5406                 break;
5407             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5408                 event[14] = 1;
5409                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5410                 // EIR packets only contain a single inquiry response
5411                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
5412                 name = NULL;
5413                 // Iterate over EIR data
5414                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
5415                     uint8_t data_type    = ad_iterator_get_data_type(&context);
5416                     uint8_t data_size    = ad_iterator_get_data_len(&context);
5417                     const uint8_t * data = ad_iterator_get_data(&context);
5418                     // Prefer Complete Local Name over Shortened Local Name
5419                     switch (data_type){
5420                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
5421                             if (name) continue;
5422                             /* fall through */
5423                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
5424                             name = data;
5425                             name_len = data_size;
5426                             break;
5427                         case BLUETOOTH_DATA_TYPE_DEVICE_ID:
5428                             if (data_size != 8) break;
5429                             event[16] = 1;
5430                             memcpy(&event[17], data, 8);
5431                             break;
5432                         default:
5433                             break;
5434                     }
5435                 }
5436                 if (name){
5437                     event[25] = 1;
5438                     // truncate name if needed
5439                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
5440                     event[26] = len;
5441                     (void)memcpy(&event[27], name, len);
5442                     event_size += len;
5443                 }
5444                 break;
5445             default:
5446                 return;
5447         }
5448         event[1] = event_size - 2;
5449         hci_emit_event(event, event_size, 1);
5450     }
5451 }
5452 #endif
5453 
5454 void hci_emit_state(void){
5455     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
5456     uint8_t event[3];
5457     event[0] = BTSTACK_EVENT_STATE;
5458     event[1] = sizeof(event) - 2u;
5459     event[2] = hci_stack->state;
5460     hci_emit_event(event, sizeof(event), 1);
5461 }
5462 
5463 #ifdef ENABLE_CLASSIC
5464 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5465     uint8_t event[13];
5466     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
5467     event[1] = sizeof(event) - 2;
5468     event[2] = status;
5469     little_endian_store_16(event, 3, con_handle);
5470     reverse_bd_addr(address, &event[5]);
5471     event[11] = 1; // ACL connection
5472     event[12] = 0; // encryption disabled
5473     hci_emit_event(event, sizeof(event), 1);
5474 }
5475 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
5476     if (disable_l2cap_timeouts) return;
5477     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
5478     uint8_t event[4];
5479     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
5480     event[1] = sizeof(event) - 2;
5481     little_endian_store_16(event, 2, conn->con_handle);
5482     hci_emit_event(event, sizeof(event), 1);
5483 }
5484 #endif
5485 
5486 #ifdef ENABLE_BLE
5487 #ifdef ENABLE_LE_CENTRAL
5488 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){
5489     uint8_t event[21];
5490     event[0] = HCI_EVENT_LE_META;
5491     event[1] = sizeof(event) - 2u;
5492     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
5493     event[3] = status;
5494     little_endian_store_16(event, 4, con_handle);
5495     event[6] = 0; // TODO: role
5496     event[7] = address_type;
5497     reverse_bd_addr(address, &event[8]);
5498     little_endian_store_16(event, 14, 0); // interval
5499     little_endian_store_16(event, 16, 0); // latency
5500     little_endian_store_16(event, 18, 0); // supervision timeout
5501     event[20] = 0; // master clock accuracy
5502     hci_emit_event(event, sizeof(event), 1);
5503 }
5504 #endif
5505 #endif
5506 
5507 static void hci_emit_transport_packet_sent(void){
5508     // notify upper stack that it might be possible to send again
5509     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
5510     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
5511 }
5512 
5513 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
5514     uint8_t event[6];
5515     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
5516     event[1] = sizeof(event) - 2u;
5517     event[2] = 0; // status = OK
5518     little_endian_store_16(event, 3, con_handle);
5519     event[5] = reason;
5520     hci_emit_event(event, sizeof(event), 1);
5521 }
5522 
5523 static void hci_emit_nr_connections_changed(void){
5524     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
5525     uint8_t event[3];
5526     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
5527     event[1] = sizeof(event) - 2u;
5528     event[2] = nr_hci_connections();
5529     hci_emit_event(event, sizeof(event), 1);
5530 }
5531 
5532 static void hci_emit_hci_open_failed(void){
5533     log_info("BTSTACK_EVENT_POWERON_FAILED");
5534     uint8_t event[2];
5535     event[0] = BTSTACK_EVENT_POWERON_FAILED;
5536     event[1] = sizeof(event) - 2u;
5537     hci_emit_event(event, sizeof(event), 1);
5538 }
5539 
5540 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
5541     log_info("hci_emit_dedicated_bonding_result %u ", status);
5542     uint8_t event[9];
5543     int pos = 0;
5544     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
5545     event[pos++] = sizeof(event) - 2u;
5546     event[pos++] = status;
5547     reverse_bd_addr(address, &event[pos]);
5548     hci_emit_event(event, sizeof(event), 1);
5549 }
5550 
5551 
5552 #ifdef ENABLE_CLASSIC
5553 
5554 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
5555     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
5556     uint8_t event[5];
5557     int pos = 0;
5558     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
5559     event[pos++] = sizeof(event) - 2;
5560     little_endian_store_16(event, 2, con_handle);
5561     pos += 2;
5562     event[pos++] = level;
5563     hci_emit_event(event, sizeof(event), 1);
5564 }
5565 
5566 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
5567     if (!connection) return LEVEL_0;
5568     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
5569     // BIAS: we only consider Authenticated if the connection is already encrypted, which requires that both sides have link key
5570     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
5571     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
5572     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
5573     // LEVEL 4 always requires 128 bit encrytion key size
5574     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
5575         security_level = LEVEL_3;
5576     }
5577     return security_level;
5578 }
5579 
5580 static void hci_emit_discoverable_enabled(uint8_t enabled){
5581     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
5582     uint8_t event[3];
5583     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
5584     event[1] = sizeof(event) - 2;
5585     event[2] = enabled;
5586     hci_emit_event(event, sizeof(event), 1);
5587 }
5588 
5589 // query if remote side supports eSCO
5590 bool hci_remote_esco_supported(hci_con_handle_t con_handle){
5591     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5592     if (!connection) return false;
5593     return (connection->remote_supported_features[0] & 1) != 0;
5594 }
5595 
5596 static bool hci_ssp_supported(hci_connection_t * connection){
5597     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
5598     return (connection->bonding_flags & mask) == mask;
5599 }
5600 
5601 // query if remote side supports SSP
5602 bool hci_remote_ssp_supported(hci_con_handle_t con_handle){
5603     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5604     if (!connection) return false;
5605     return hci_ssp_supported(connection) ? 1 : 0;
5606 }
5607 
5608 bool gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
5609     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
5610 }
5611 
5612 /**
5613  * Check if remote supported features query has completed
5614  */
5615 bool hci_remote_features_available(hci_con_handle_t handle){
5616     hci_connection_t * connection = hci_connection_for_handle(handle);
5617     if (!connection) return false;
5618     return (connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0;
5619 }
5620 
5621 /**
5622  * Trigger remote supported features query
5623  */
5624 
5625 static void hci_trigger_remote_features_for_connection(hci_connection_t * connection){
5626     if ((connection->bonding_flags & (BONDING_REMOTE_FEATURES_QUERY_ACTIVE | BONDING_RECEIVED_REMOTE_FEATURES)) == 0){
5627         connection->bonding_flags |= BONDING_REMOTE_FEATURES_QUERY_ACTIVE | BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
5628     }
5629 }
5630 
5631 void hci_remote_features_query(hci_con_handle_t con_handle){
5632     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5633     if (!connection) return;
5634     hci_trigger_remote_features_for_connection(connection);
5635     hci_run();
5636 }
5637 
5638 // GAP API
5639 /**
5640  * @bbrief enable/disable bonding. default is enabled
5641  * @praram enabled
5642  */
5643 void gap_set_bondable_mode(int enable){
5644     hci_stack->bondable = enable ? 1 : 0;
5645 }
5646 /**
5647  * @brief Get bondable mode.
5648  * @return 1 if bondable
5649  */
5650 int gap_get_bondable_mode(void){
5651     return hci_stack->bondable;
5652 }
5653 
5654 /**
5655  * @brief map link keys to security levels
5656  */
5657 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
5658     switch (link_key_type){
5659         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5660             return LEVEL_4;
5661         case COMBINATION_KEY:
5662         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5663             return LEVEL_3;
5664         default:
5665             return LEVEL_2;
5666     }
5667 }
5668 
5669 /**
5670  * @brief map link keys to secure connection yes/no
5671  */
5672 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
5673     switch (link_key_type){
5674         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5675         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5676             return 1;
5677         default:
5678             return 0;
5679     }
5680 }
5681 
5682 /**
5683  * @brief map link keys to authenticated
5684  */
5685 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
5686     switch (link_key_type){
5687         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5688         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5689             return 1;
5690         default:
5691             return 0;
5692     }
5693 }
5694 
5695 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
5696     log_info("gap_mitm_protection_required_for_security_level %u", level);
5697     return level > LEVEL_2;
5698 }
5699 
5700 /**
5701  * @brief get current security level
5702  */
5703 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
5704     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5705     if (!connection) return LEVEL_0;
5706     return gap_security_level_for_connection(connection);
5707 }
5708 
5709 /**
5710  * @brief request connection to device to
5711  * @result GAP_AUTHENTICATION_RESULT
5712  */
5713 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
5714     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5715     if (!connection){
5716         hci_emit_security_level(con_handle, LEVEL_0);
5717         return;
5718     }
5719 
5720     btstack_assert(hci_is_le_connection(connection) == false);
5721 
5722     // 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)
5723     // available on the BR/EDR physical transport require Security Mode 4, Level 4 "
5724     if (hci_stack->gap_secure_connections_only_mode && (requested_level != LEVEL_0)){
5725         requested_level = LEVEL_4;
5726     }
5727 
5728     gap_security_level_t current_level = gap_security_level(con_handle);
5729     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
5730         requested_level, connection->requested_security_level, current_level);
5731 
5732     // authentication active if authentication request was sent or planned level > 0
5733     bool authentication_active = ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) || (connection->requested_security_level > LEVEL_0);
5734     if (authentication_active){
5735         // authentication already active
5736         if (connection->requested_security_level < requested_level){
5737             // increase requested level as new level is higher
5738             // TODO: handle re-authentication when done
5739             connection->requested_security_level = requested_level;
5740         }
5741     } else {
5742         // no request active, notify if security sufficient
5743         if (requested_level <= current_level){
5744             hci_emit_security_level(con_handle, current_level);
5745             return;
5746         }
5747 
5748         // store request
5749         connection->requested_security_level = requested_level;
5750 
5751         // request remote features if not already active
5752         hci_remote_features_query(con_handle);
5753 
5754         // start to authenticate connection
5755         connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
5756         hci_run();
5757     }
5758 }
5759 
5760 /**
5761  * @brief start dedicated bonding with device. disconnect after bonding
5762  * @param device
5763  * @param request MITM protection
5764  * @result GAP_DEDICATED_BONDING_COMPLETE
5765  */
5766 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
5767 
5768     // create connection state machine
5769     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
5770 
5771     if (!connection){
5772         return BTSTACK_MEMORY_ALLOC_FAILED;
5773     }
5774 
5775     // delete linkn key
5776     gap_drop_link_key_for_bd_addr(device);
5777 
5778     // configure LEVEL_2/3, dedicated bonding
5779     connection->state = SEND_CREATE_CONNECTION;
5780     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
5781     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
5782     connection->bonding_flags = BONDING_DEDICATED;
5783 
5784     // wait for GAP Security Result and send GAP Dedicated Bonding complete
5785 
5786     // handle: connnection failure (connection complete != ok)
5787     // handle: authentication failure
5788     // handle: disconnect on done
5789 
5790     hci_run();
5791 
5792     return 0;
5793 }
5794 
5795 void gap_set_local_name(const char * local_name){
5796     hci_stack->local_name = local_name;
5797     hci_stack->gap_tasks |= GAP_TASK_SET_LOCAL_NAME;
5798     // also update EIR if not set by user
5799     if (hci_stack->eir_data == NULL){
5800         hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
5801     }
5802     hci_run();
5803 }
5804 #endif
5805 
5806 
5807 #ifdef ENABLE_BLE
5808 
5809 #ifdef ENABLE_LE_CENTRAL
5810 void gap_start_scan(void){
5811     hci_stack->le_scanning_enabled = true;
5812     hci_run();
5813 }
5814 
5815 void gap_stop_scan(void){
5816     hci_stack->le_scanning_enabled = false;
5817     hci_run();
5818 }
5819 
5820 void gap_set_scan_params(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window, uint8_t scanning_filter_policy){
5821     hci_stack->le_scan_type          = scan_type;
5822     hci_stack->le_scan_filter_policy = scanning_filter_policy;
5823     hci_stack->le_scan_interval      = scan_interval;
5824     hci_stack->le_scan_window        = scan_window;
5825     hci_stack->le_scanning_param_update = true;
5826     hci_run();
5827 }
5828 
5829 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
5830     gap_set_scan_params(scan_type, scan_interval, scan_window, 0);
5831 }
5832 
5833 uint8_t gap_connect(const bd_addr_t addr, bd_addr_type_t addr_type){
5834     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
5835     if (!conn){
5836         // disallow if le connection is already outgoing
5837         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5838             log_error("le connection already active");
5839             return ERROR_CODE_COMMAND_DISALLOWED;
5840         }
5841 
5842         log_info("gap_connect: no connection exists yet, creating context");
5843         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
5844         if (!conn){
5845             // notify client that alloc failed
5846             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5847             log_info("gap_connect: failed to alloc hci_connection_t");
5848             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
5849         }
5850 
5851         // set le connecting state
5852         if (hci_is_le_connection_type(addr_type)){
5853             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
5854         }
5855 
5856         conn->state = SEND_CREATE_CONNECTION;
5857         log_info("gap_connect: send create connection next");
5858         hci_run();
5859         return ERROR_CODE_SUCCESS;
5860     }
5861 
5862     if (!hci_is_le_connection(conn) ||
5863         (conn->state == SEND_CREATE_CONNECTION) ||
5864         (conn->state == SENT_CREATE_CONNECTION)) {
5865         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
5866         log_error("gap_connect: classic connection or connect is already being created");
5867         return GATT_CLIENT_IN_WRONG_STATE;
5868     }
5869 
5870     // check if connection was just disconnected
5871     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5872         log_info("gap_connect: send create connection (again)");
5873         conn->state = SEND_CREATE_CONNECTION;
5874         hci_run();
5875         return ERROR_CODE_SUCCESS;
5876     }
5877 
5878     log_info("gap_connect: context exists with state %u", conn->state);
5879     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
5880     hci_run();
5881     return ERROR_CODE_SUCCESS;
5882 }
5883 
5884 // @assumption: only a single outgoing LE Connection exists
5885 static hci_connection_t * gap_get_outgoing_connection(void){
5886     btstack_linked_item_t *it;
5887     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5888         hci_connection_t * conn = (hci_connection_t *) it;
5889         if (!hci_is_le_connection(conn)) continue;
5890         switch (conn->state){
5891             case SEND_CREATE_CONNECTION:
5892             case SENT_CREATE_CONNECTION:
5893             case SENT_CANCEL_CONNECTION:
5894                 return conn;
5895             default:
5896                 break;
5897         };
5898     }
5899     return NULL;
5900 }
5901 
5902 uint8_t gap_connect_cancel(void){
5903     hci_connection_t * conn = gap_get_outgoing_connection();
5904     if (!conn) return 0;
5905     switch (conn->state){
5906         case SEND_CREATE_CONNECTION:
5907             // skip sending create connection and emit event instead
5908             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5909             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5910             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5911             btstack_memory_hci_connection_free( conn );
5912             break;
5913         case SENT_CREATE_CONNECTION:
5914             // request to send cancel connection
5915             conn->state = SEND_CANCEL_CONNECTION;
5916             hci_run();
5917             break;
5918         default:
5919             break;
5920     }
5921     return 0;
5922 }
5923 #endif
5924 
5925 #ifdef ENABLE_LE_CENTRAL
5926 /**
5927  * @brief Set connection parameters for outgoing connections
5928  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5929  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5930  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5931  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5932  * @param conn_latency, default: 4
5933  * @param supervision_timeout (unit: 10ms), default: 720 ms
5934  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5935  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5936  */
5937 
5938 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5939     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5940     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5941     hci_stack->le_connection_scan_interval = conn_scan_interval;
5942     hci_stack->le_connection_scan_window = conn_scan_window;
5943     hci_stack->le_connection_interval_min = conn_interval_min;
5944     hci_stack->le_connection_interval_max = conn_interval_max;
5945     hci_stack->le_connection_latency = conn_latency;
5946     hci_stack->le_supervision_timeout = supervision_timeout;
5947     hci_stack->le_minimum_ce_length = min_ce_length;
5948     hci_stack->le_maximum_ce_length = max_ce_length;
5949 }
5950 #endif
5951 
5952 /**
5953  * @brief Updates the connection parameters for a given LE connection
5954  * @param handle
5955  * @param conn_interval_min (unit: 1.25ms)
5956  * @param conn_interval_max (unit: 1.25ms)
5957  * @param conn_latency
5958  * @param supervision_timeout (unit: 10ms)
5959  * @return 0 if ok
5960  */
5961 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5962     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5963     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5964     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5965     connection->le_conn_interval_min = conn_interval_min;
5966     connection->le_conn_interval_max = conn_interval_max;
5967     connection->le_conn_latency = conn_latency;
5968     connection->le_supervision_timeout = supervision_timeout;
5969     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5970     hci_run();
5971     return 0;
5972 }
5973 
5974 /**
5975  * @brief Request an update of the connection parameter for a given LE connection
5976  * @param handle
5977  * @param conn_interval_min (unit: 1.25ms)
5978  * @param conn_interval_max (unit: 1.25ms)
5979  * @param conn_latency
5980  * @param supervision_timeout (unit: 10ms)
5981  * @return 0 if ok
5982  */
5983 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5984     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5985     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5986     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5987     connection->le_conn_interval_min = conn_interval_min;
5988     connection->le_conn_interval_max = conn_interval_max;
5989     connection->le_conn_latency = conn_latency;
5990     connection->le_supervision_timeout = supervision_timeout;
5991     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5992     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5993     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5994     return 0;
5995 }
5996 
5997 #ifdef ENABLE_LE_PERIPHERAL
5998 
5999 /**
6000  * @brief Set Advertisement Data
6001  * @param advertising_data_length
6002  * @param advertising_data (max 31 octets)
6003  * @note data is not copied, pointer has to stay valid
6004  */
6005 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
6006     hci_stack->le_advertisements_data_len = advertising_data_length;
6007     hci_stack->le_advertisements_data = advertising_data;
6008     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
6009     hci_run();
6010 }
6011 
6012 /**
6013  * @brief Set Scan Response Data
6014  * @param advertising_data_length
6015  * @param advertising_data (max 31 octets)
6016  * @note data is not copied, pointer has to stay valid
6017  */
6018 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
6019     hci_stack->le_scan_response_data_len = scan_response_data_length;
6020     hci_stack->le_scan_response_data = scan_response_data;
6021     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
6022     hci_run();
6023 }
6024 
6025 /**
6026  * @brief Set Advertisement Parameters
6027  * @param adv_int_min
6028  * @param adv_int_max
6029  * @param adv_type
6030  * @param direct_address_type
6031  * @param direct_address
6032  * @param channel_map
6033  * @param filter_policy
6034  *
6035  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
6036  */
6037  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
6038     uint8_t direct_address_typ, bd_addr_t direct_address,
6039     uint8_t channel_map, uint8_t filter_policy) {
6040 
6041     hci_stack->le_advertisements_interval_min = adv_int_min;
6042     hci_stack->le_advertisements_interval_max = adv_int_max;
6043     hci_stack->le_advertisements_type = adv_type;
6044     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
6045     hci_stack->le_advertisements_channel_map = channel_map;
6046     hci_stack->le_advertisements_filter_policy = filter_policy;
6047     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
6048                  6);
6049 
6050     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS | LE_ADVERTISEMENT_TASKS_PARAMS_SET;
6051     hci_run();
6052  }
6053 
6054 /**
6055  * @brief Enable/Disable Advertisements
6056  * @param enabled
6057  */
6058 void gap_advertisements_enable(int enabled){
6059     hci_stack->le_advertisements_enabled = enabled != 0;
6060     hci_update_advertisements_enabled_for_current_roles();
6061     hci_run();
6062 }
6063 
6064 #endif
6065 
6066 void hci_le_set_own_address_type(uint8_t own_address_type){
6067     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
6068     if (own_address_type == hci_stack->le_own_addr_type) return;
6069     hci_stack->le_own_addr_type = own_address_type;
6070 
6071 #ifdef ENABLE_LE_PERIPHERAL
6072     // update advertisement parameters, too
6073     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
6074     hci_run();
6075 #endif
6076 #ifdef ENABLE_LE_CENTRAL
6077     // note: we don't update scan parameters or modify ongoing connection attempts
6078 #endif
6079 }
6080 
6081 void hci_le_random_address_set(const bd_addr_t random_address){
6082     memcpy(hci_stack->le_random_address, random_address, 6);
6083     hci_stack->le_random_address_set = true;
6084     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADDRESS;
6085     hci_run();
6086 }
6087 
6088 #endif
6089 
6090 uint8_t gap_disconnect(hci_con_handle_t handle){
6091     hci_connection_t * conn = hci_connection_for_handle(handle);
6092     if (!conn){
6093         hci_emit_disconnection_complete(handle, 0);
6094         return 0;
6095     }
6096     // ignore if already disconnected
6097     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
6098         return 0;
6099     }
6100     conn->state = SEND_DISCONNECT;
6101     hci_run();
6102     return 0;
6103 }
6104 
6105 int gap_read_rssi(hci_con_handle_t con_handle){
6106     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6107     if (hci_connection == NULL) return 0;
6108     connectionSetAuthenticationFlags(hci_connection, AUTH_FLAG_READ_RSSI);
6109     hci_run();
6110     return 1;
6111 }
6112 
6113 /**
6114  * @brief Get connection type
6115  * @param con_handle
6116  * @result connection_type
6117  */
6118 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
6119     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6120     if (!conn) return GAP_CONNECTION_INVALID;
6121     switch (conn->address_type){
6122         case BD_ADDR_TYPE_LE_PUBLIC:
6123         case BD_ADDR_TYPE_LE_RANDOM:
6124             return GAP_CONNECTION_LE;
6125         case BD_ADDR_TYPE_SCO:
6126             return GAP_CONNECTION_SCO;
6127         case BD_ADDR_TYPE_ACL:
6128             return GAP_CONNECTION_ACL;
6129         default:
6130             return GAP_CONNECTION_INVALID;
6131     }
6132 }
6133 
6134 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
6135     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6136     if (!conn) return HCI_ROLE_INVALID;
6137     return (hci_role_t) conn->role;
6138 }
6139 
6140 
6141 #ifdef ENABLE_CLASSIC
6142 uint8_t gap_request_role(const bd_addr_t addr, hci_role_t role){
6143     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6144     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6145     conn->request_role = role;
6146     hci_run();
6147     return ERROR_CODE_SUCCESS;
6148 }
6149 #endif
6150 
6151 #ifdef ENABLE_BLE
6152 
6153 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){
6154     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6155     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6156 
6157     conn->le_phy_update_all_phys    = all_phys;
6158     conn->le_phy_update_tx_phys     = tx_phys;
6159     conn->le_phy_update_rx_phys     = rx_phys;
6160     conn->le_phy_update_phy_options = phy_options;
6161 
6162     hci_run();
6163 
6164     return 0;
6165 }
6166 
6167 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6168     // check if already in list
6169     btstack_linked_list_iterator_t it;
6170     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6171     while (btstack_linked_list_iterator_has_next(&it)) {
6172         whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&it);
6173         if (entry->address_type != address_type) {
6174             continue;
6175         }
6176         if (memcmp(entry->address, address, 6) != 0) {
6177             continue;
6178         }
6179 		// disallow if already scheduled to add
6180 		if ((entry->state & LE_WHITELIST_ADD_TO_CONTROLLER) != 0){
6181 			return ERROR_CODE_COMMAND_DISALLOWED;
6182 		}
6183 		// still on controller, but scheduled to remove -> re-add
6184 		entry->state |= LE_WHITELIST_ADD_TO_CONTROLLER;
6185 		return ERROR_CODE_SUCCESS;
6186     }
6187     // alloc and add to list
6188     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
6189     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
6190     entry->address_type = address_type;
6191     (void)memcpy(entry->address, address, 6);
6192     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
6193     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
6194     return ERROR_CODE_SUCCESS;
6195 }
6196 
6197 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6198     btstack_linked_list_iterator_t it;
6199     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6200     while (btstack_linked_list_iterator_has_next(&it)){
6201         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6202         if (entry->address_type != address_type) {
6203             continue;
6204         }
6205         if (memcmp(entry->address, address, 6) != 0) {
6206             continue;
6207         }
6208         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6209             // remove from controller if already present
6210             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6211         }  else {
6212             // directly remove entry from whitelist
6213             btstack_linked_list_iterator_remove(&it);
6214             btstack_memory_whitelist_entry_free(entry);
6215         }
6216         return ERROR_CODE_SUCCESS;
6217     }
6218     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6219 }
6220 
6221 static void hci_whitelist_clear(void){
6222     btstack_linked_list_iterator_t it;
6223     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6224     while (btstack_linked_list_iterator_has_next(&it)){
6225         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6226         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6227             // remove from controller if already present
6228             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6229             continue;
6230         }
6231         // directly remove entry from whitelist
6232         btstack_linked_list_iterator_remove(&it);
6233         btstack_memory_whitelist_entry_free(entry);
6234     }
6235 }
6236 
6237 // free all entries unconditionally
6238 static void hci_whitelist_free(void){
6239     btstack_linked_list_iterator_t lit;
6240     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
6241     while (btstack_linked_list_iterator_has_next(&lit)){
6242         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
6243         btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
6244         btstack_memory_whitelist_entry_free(entry);
6245     }
6246 }
6247 
6248 /**
6249  * @brief Clear Whitelist
6250  * @return 0 if ok
6251  */
6252 uint8_t gap_whitelist_clear(void){
6253     hci_whitelist_clear();
6254     hci_run();
6255     return ERROR_CODE_SUCCESS;
6256 }
6257 
6258 /**
6259  * @brief Add Device to Whitelist
6260  * @param address_typ
6261  * @param address
6262  * @return 0 if ok
6263  */
6264 uint8_t gap_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6265     uint8_t status = hci_whitelist_add(address_type, address);
6266     if (status){
6267         return status;
6268     }
6269     hci_run();
6270     return ERROR_CODE_SUCCESS;
6271 }
6272 
6273 /**
6274  * @brief Remove Device from Whitelist
6275  * @param address_typ
6276  * @param address
6277  * @return 0 if ok
6278  */
6279 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6280     uint8_t status = hci_whitelist_remove(address_type, address);
6281     if (status){
6282         return status;
6283     }
6284     hci_run();
6285     return ERROR_CODE_SUCCESS;
6286 }
6287 
6288 #ifdef ENABLE_LE_CENTRAL
6289 /**
6290  * @brief Connect with Whitelist
6291  * @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
6292  * @return - if ok
6293  */
6294 uint8_t gap_connect_with_whitelist(void){
6295     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
6296         return ERROR_CODE_COMMAND_DISALLOWED;
6297     }
6298     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6299     hci_run();
6300     return ERROR_CODE_SUCCESS;
6301 }
6302 
6303 /**
6304  * @brief Auto Connection Establishment - Start Connecting to device
6305  * @param address_typ
6306  * @param address
6307  * @return 0 if ok
6308  */
6309 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, const bd_addr_t address){
6310     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6311         return ERROR_CODE_COMMAND_DISALLOWED;
6312     }
6313 
6314     uint8_t status = hci_whitelist_add(address_type, address);
6315     if (status == BTSTACK_MEMORY_ALLOC_FAILED) {
6316         return status;
6317     }
6318 
6319     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6320 
6321     hci_run();
6322     return ERROR_CODE_SUCCESS;
6323 }
6324 
6325 /**
6326  * @brief Auto Connection Establishment - Stop Connecting to device
6327  * @param address_typ
6328  * @param address
6329  * @return 0 if ok
6330  */
6331 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, const bd_addr_t address){
6332     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6333         return ERROR_CODE_COMMAND_DISALLOWED;
6334     }
6335 
6336     hci_whitelist_remove(address_type, address);
6337     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
6338         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6339     }
6340     hci_run();
6341     return 0;
6342 }
6343 
6344 /**
6345  * @brief Auto Connection Establishment - Stop everything
6346  * @note  Convenience function to stop all active auto connection attempts
6347  */
6348 uint8_t gap_auto_connection_stop_all(void){
6349     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
6350         return ERROR_CODE_COMMAND_DISALLOWED;
6351     }
6352     hci_whitelist_clear();
6353     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6354     hci_run();
6355     return ERROR_CODE_SUCCESS;
6356 }
6357 
6358 uint16_t gap_le_connection_interval(hci_con_handle_t con_handle){
6359     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6360     if (!conn) return 0;
6361     return conn->le_connection_interval;
6362 }
6363 #endif
6364 #endif
6365 
6366 #ifdef ENABLE_CLASSIC
6367 /**
6368  * @brief Set Extended Inquiry Response data
6369  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
6370  * @note has to be done before stack starts up
6371  */
6372 void gap_set_extended_inquiry_response(const uint8_t * data){
6373     hci_stack->eir_data = data;
6374     hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
6375     hci_run();
6376 }
6377 
6378 /**
6379  * @brief Start GAP Classic Inquiry
6380  * @param duration in 1.28s units
6381  * @return 0 if ok
6382  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
6383  */
6384 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
6385     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
6386     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6387     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
6388         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
6389     }
6390     hci_stack->inquiry_state = duration_in_1280ms_units;
6391     hci_run();
6392     return 0;
6393 }
6394 
6395 /**
6396  * @brief Stop GAP Classic Inquiry
6397  * @return 0 if ok
6398  */
6399 int gap_inquiry_stop(void){
6400     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
6401         // emit inquiry complete event, before it even started
6402         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
6403         hci_emit_event(event, sizeof(event), 1);
6404         return 0;
6405     }
6406     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
6407     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
6408     hci_run();
6409     return 0;
6410 }
6411 
6412 void gap_inquiry_set_lap(uint32_t lap){
6413     hci_stack->inquiry_lap = lap;
6414 }
6415 
6416 void gap_inquiry_set_scan_activity(uint16_t inquiry_scan_interval, uint16_t inquiry_scan_window){
6417     hci_stack->inquiry_scan_interval = inquiry_scan_interval;
6418     hci_stack->inquiry_scan_window   = inquiry_scan_window;
6419     hci_stack->gap_tasks |= GAP_TASK_WRITE_INQUIRY_SCAN_ACTIVITY;
6420     hci_run();
6421 }
6422 
6423 
6424 /**
6425  * @brief Remote Name Request
6426  * @param addr
6427  * @param page_scan_repetition_mode
6428  * @param clock_offset only used when bit 15 is set
6429  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
6430  */
6431 int gap_remote_name_request(const bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
6432     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6433     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
6434     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
6435     hci_stack->remote_name_clock_offset = clock_offset;
6436     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
6437     hci_run();
6438     return 0;
6439 }
6440 
6441 static int gap_pairing_set_state_and_run(const bd_addr_t addr, uint8_t state){
6442     hci_stack->gap_pairing_state = state;
6443     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
6444     hci_run();
6445     return 0;
6446 }
6447 
6448 /**
6449  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
6450  * @param addr
6451  * @param pin_data
6452  * @param pin_len
6453  * @return 0 if ok
6454  */
6455 int gap_pin_code_response_binary(const bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
6456     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6457     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
6458     hci_stack->gap_pairing_pin_len = pin_len;
6459     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
6460 }
6461 
6462 /**
6463  * @brief Legacy Pairing Pin Code Response
6464  * @param addr
6465  * @param pin
6466  * @return 0 if ok
6467  */
6468 int gap_pin_code_response(const bd_addr_t addr, const char * pin){
6469     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
6470 }
6471 
6472 /**
6473  * @brief Abort Legacy Pairing
6474  * @param addr
6475  * @param pin
6476  * @return 0 if ok
6477  */
6478 int gap_pin_code_negative(bd_addr_t addr){
6479     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6480     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
6481 }
6482 
6483 /**
6484  * @brief SSP Passkey Response
6485  * @param addr
6486  * @param passkey
6487  * @return 0 if ok
6488  */
6489 int gap_ssp_passkey_response(const bd_addr_t addr, uint32_t passkey){
6490     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6491     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
6492     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
6493 }
6494 
6495 /**
6496  * @brief Abort SSP Passkey Entry/Pairing
6497  * @param addr
6498  * @param pin
6499  * @return 0 if ok
6500  */
6501 int gap_ssp_passkey_negative(const bd_addr_t addr){
6502     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6503     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
6504 }
6505 
6506 /**
6507  * @brief Accept SSP Numeric Comparison
6508  * @param addr
6509  * @param passkey
6510  * @return 0 if ok
6511  */
6512 int gap_ssp_confirmation_response(const bd_addr_t addr){
6513     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6514     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
6515 }
6516 
6517 /**
6518  * @brief Abort SSP Numeric Comparison/Pairing
6519  * @param addr
6520  * @param pin
6521  * @return 0 if ok
6522  */
6523 int gap_ssp_confirmation_negative(const bd_addr_t addr){
6524     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6525     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
6526 }
6527 
6528 #if defined(ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY) || defined(ENABLE_EXPLICIT_LINK_KEY_REPLY)
6529 static uint8_t gap_set_auth_flag_and_run(const bd_addr_t addr, hci_authentication_flags_t flag){
6530     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6531     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6532     connectionSetAuthenticationFlags(conn, flag);
6533     hci_run();
6534     return ERROR_CODE_SUCCESS;
6535 }
6536 #endif
6537 
6538 #ifdef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
6539 uint8_t gap_ssp_io_capabilities_response(const bd_addr_t addr){
6540     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
6541 }
6542 
6543 uint8_t gap_ssp_io_capabilities_negative(const bd_addr_t addr){
6544     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
6545 }
6546 #endif
6547 
6548 #ifdef ENABLE_CLASSIC_PAIRING_OOB
6549 /**
6550  * @brief Report Remote OOB Data
6551  * @param bd_addr
6552  * @param c_192 Simple Pairing Hash C derived from P-192 public key
6553  * @param r_192 Simple Pairing Randomizer derived from P-192 public key
6554  * @param c_256 Simple Pairing Hash C derived from P-256 public key
6555  * @param r_256 Simple Pairing Randomizer derived from P-256 public key
6556  */
6557 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){
6558     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6559     if (connection == NULL) {
6560         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6561     }
6562     connection->classic_oob_c_192 = c_192;
6563     connection->classic_oob_r_192 = r_192;
6564 
6565     // ignore P-256 if not supported by us
6566     if (hci_stack->secure_connections_active){
6567         connection->classic_oob_c_256 = c_256;
6568         connection->classic_oob_r_256 = r_256;
6569     }
6570 
6571     return ERROR_CODE_SUCCESS;
6572 }
6573 /**
6574  * @brief Generate new OOB data
6575  * @note OOB data will be provided in GAP_EVENT_LOCAL_OOB_DATA and be used in future pairing procedures
6576  */
6577 void gap_ssp_generate_oob_data(void){
6578     hci_stack->classic_read_local_oob_data = true;
6579     hci_run();
6580 }
6581 
6582 #endif
6583 
6584 #ifdef ENABLE_EXPLICIT_LINK_KEY_REPLY
6585 uint8_t gap_send_link_key_response(const bd_addr_t addr, link_key_t link_key, link_key_type_t type){
6586     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6587     if (connection == NULL) {
6588         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6589     }
6590 
6591     memcpy(connection->link_key, link_key, sizeof(link_key_t));
6592     connection->link_key_type = type;
6593 
6594     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
6595 }
6596 
6597 #endif // ENABLE_EXPLICIT_LINK_KEY_REPLY
6598 /**
6599  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
6600  * @param inquiry_mode see bluetooth_defines.h
6601  */
6602 void hci_set_inquiry_mode(inquiry_mode_t inquiry_mode){
6603     hci_stack->inquiry_mode = inquiry_mode;
6604 }
6605 
6606 /**
6607  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
6608  */
6609 void hci_set_sco_voice_setting(uint16_t voice_setting){
6610     hci_stack->sco_voice_setting = voice_setting;
6611 }
6612 
6613 /**
6614  * @brief Get SCO Voice Setting
6615  * @return current voice setting
6616  */
6617 uint16_t hci_get_sco_voice_setting(void){
6618     return hci_stack->sco_voice_setting;
6619 }
6620 
6621 static int hci_have_usb_transport(void){
6622     if (!hci_stack->hci_transport) return 0;
6623     const char * transport_name = hci_stack->hci_transport->name;
6624     if (!transport_name) return 0;
6625     return (transport_name[0] == 'H') && (transport_name[1] == '2');
6626 }
6627 
6628 /** @brief Get SCO packet length for current SCO Voice setting
6629  *  @note  Using SCO packets of the exact length is required for USB transfer
6630  *  @return Length of SCO packets in bytes (not audio frames)
6631  */
6632 uint16_t hci_get_sco_packet_length(void){
6633     uint16_t sco_packet_length = 0;
6634 
6635 #ifdef ENABLE_SCO_OVER_HCI
6636     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6637     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6638 
6639     if (hci_have_usb_transport()){
6640         // see Core Spec for H2 USB Transfer.
6641         // 3 byte SCO header + 24 bytes per connection
6642         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
6643         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
6644     } else {
6645         // 3 byte SCO header + SCO packet size over the air (60 bytes)
6646         sco_packet_length = 3 + 60 * multiplier;
6647         // assert that it still fits inside an SCO buffer
6648         if (sco_packet_length > hci_stack->sco_data_packet_length){
6649             sco_packet_length = 3 + 60;
6650         }
6651     }
6652 #endif
6653 
6654 #ifdef HAVE_SCO_TRANSPORT
6655     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6656     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6657     sco_packet_length = 3 + 60 * multiplier;
6658 #endif
6659     return sco_packet_length;
6660 }
6661 
6662 /**
6663 * @brief Sets the master/slave policy
6664 * @param policy (0: attempt to become master, 1: let connecting device decide)
6665 */
6666 void hci_set_master_slave_policy(uint8_t policy){
6667     hci_stack->master_slave_policy = policy;
6668 }
6669 
6670 #endif
6671 
6672 HCI_STATE hci_get_state(void){
6673     return hci_stack->state;
6674 }
6675 
6676 #ifdef ENABLE_CLASSIC
6677 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr, hci_link_type_t link_type)){
6678     hci_stack->gap_classic_accept_callback = accept_callback;
6679 }
6680 #endif
6681 
6682 /**
6683  * @brief Set callback for Bluetooth Hardware Error
6684  */
6685 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
6686     hci_stack->hardware_error_callback = fn;
6687 }
6688 
6689 void hci_disconnect_all(void){
6690     btstack_linked_list_iterator_t it;
6691     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6692     while (btstack_linked_list_iterator_has_next(&it)){
6693         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6694         if (con->state == SENT_DISCONNECT) continue;
6695         con->state = SEND_DISCONNECT;
6696     }
6697     hci_run();
6698 }
6699 
6700 uint16_t hci_get_manufacturer(void){
6701     return hci_stack->manufacturer;
6702 }
6703 
6704 #ifdef ENABLE_BLE
6705 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
6706     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
6707     if (!hci_con) return NULL;
6708     return &hci_con->sm_connection;
6709 }
6710 
6711 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
6712 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
6713 #endif
6714 
6715 int gap_encryption_key_size(hci_con_handle_t con_handle){
6716     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6717     if (hci_connection == NULL) return 0;
6718     if (hci_is_le_connection(hci_connection)){
6719 #ifdef ENABLE_BLE
6720         sm_connection_t * sm_conn = &hci_connection->sm_connection;
6721         if (sm_conn->sm_connection_encrypted) {
6722             return sm_conn->sm_actual_encryption_key_size;
6723         }
6724 #endif
6725     } else {
6726 #ifdef ENABLE_CLASSIC
6727         if ((hci_connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED)){
6728             return hci_connection->encryption_key_size;
6729         }
6730 #endif
6731     }
6732     return 0;
6733 }
6734 
6735 int gap_authenticated(hci_con_handle_t con_handle){
6736     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6737     if (hci_connection == NULL) return 0;
6738 
6739     switch (hci_connection->address_type){
6740 #ifdef ENABLE_BLE
6741         case BD_ADDR_TYPE_LE_PUBLIC:
6742         case BD_ADDR_TYPE_LE_RANDOM:
6743             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6744             return hci_connection->sm_connection.sm_connection_authenticated;
6745 #endif
6746 #ifdef ENABLE_CLASSIC
6747         case BD_ADDR_TYPE_SCO:
6748         case BD_ADDR_TYPE_ACL:
6749             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
6750 #endif
6751         default:
6752             return 0;
6753     }
6754 }
6755 
6756 int gap_secure_connection(hci_con_handle_t con_handle){
6757     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6758     if (hci_connection == NULL) return 0;
6759 
6760     switch (hci_connection->address_type){
6761 #ifdef ENABLE_BLE
6762         case BD_ADDR_TYPE_LE_PUBLIC:
6763         case BD_ADDR_TYPE_LE_RANDOM:
6764             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6765             return hci_connection->sm_connection.sm_connection_sc;
6766 #endif
6767 #ifdef ENABLE_CLASSIC
6768         case BD_ADDR_TYPE_SCO:
6769         case BD_ADDR_TYPE_ACL:
6770             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
6771 #endif
6772         default:
6773             return 0;
6774     }
6775 }
6776 
6777 bool gap_bonded(hci_con_handle_t con_handle){
6778 	hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6779 	if (hci_connection == NULL) return 0;
6780 
6781 #ifdef ENABLE_CLASSIC
6782 	link_key_t link_key;
6783 	link_key_type_t link_key_type;
6784 #endif
6785 	switch (hci_connection->address_type){
6786 #ifdef ENABLE_BLE
6787 		case BD_ADDR_TYPE_LE_PUBLIC:
6788 		case BD_ADDR_TYPE_LE_RANDOM:
6789 			return hci_connection->sm_connection.sm_le_db_index >= 0;
6790 #endif
6791 #ifdef ENABLE_CLASSIC
6792 		case BD_ADDR_TYPE_SCO:
6793 		case BD_ADDR_TYPE_ACL:
6794 			return hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(hci_connection->address, link_key, &link_key_type);
6795 #endif
6796 		default:
6797 			return false;
6798 	}
6799 }
6800 
6801 #ifdef ENABLE_BLE
6802 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
6803     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
6804     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
6805     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
6806     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
6807     return sm_conn->sm_connection_authorization_state;
6808 }
6809 #endif
6810 
6811 #ifdef ENABLE_CLASSIC
6812 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){
6813     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6814     if (!conn) return GAP_CONNECTION_INVALID;
6815     conn->sniff_min_interval = sniff_min_interval;
6816     conn->sniff_max_interval = sniff_max_interval;
6817     conn->sniff_attempt = sniff_attempt;
6818     conn->sniff_timeout = sniff_timeout;
6819     hci_run();
6820     return 0;
6821 }
6822 
6823 /**
6824  * @brief Exit Sniff mode
6825  * @param con_handle
6826  @ @return 0 if ok
6827  */
6828 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
6829     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6830     if (!conn) return GAP_CONNECTION_INVALID;
6831     conn->sniff_min_interval = 0xffff;
6832     hci_run();
6833     return 0;
6834 }
6835 
6836 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){
6837     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6838     if (!conn) return GAP_CONNECTION_INVALID;
6839     conn->sniff_subrating_max_latency = max_latency;
6840     conn->sniff_subrating_min_remote_timeout = min_remote_timeout;
6841     conn->sniff_subrating_min_local_timeout = min_local_timeout;
6842     hci_run();
6843     return ERROR_CODE_SUCCESS;
6844 }
6845 
6846 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){
6847     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6848     if (!conn) return GAP_CONNECTION_INVALID;
6849     conn->qos_service_type = service_type;
6850     conn->qos_token_rate = token_rate;
6851     conn->qos_peak_bandwidth = peak_bandwidth;
6852     conn->qos_latency = latency;
6853     conn->qos_delay_variation = delay_variation;
6854     hci_run();
6855     return ERROR_CODE_SUCCESS;
6856 }
6857 
6858 void gap_set_page_scan_activity(uint16_t page_scan_interval, uint16_t page_scan_window){
6859     hci_stack->new_page_scan_interval = page_scan_interval;
6860     hci_stack->new_page_scan_window = page_scan_window;
6861     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
6862     hci_run();
6863 }
6864 
6865 void gap_set_page_scan_type(page_scan_type_t page_scan_type){
6866     hci_stack->new_page_scan_type = (uint8_t) page_scan_type;
6867     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_TYPE;
6868     hci_run();
6869 }
6870 
6871 void gap_set_page_timeout(uint16_t page_timeout){
6872     hci_stack->page_timeout = page_timeout;
6873     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_TIMEOUT;
6874     hci_run();
6875 }
6876 
6877 #endif
6878 
6879 void hci_halting_defer(void){
6880     if (hci_stack->state != HCI_STATE_HALTING) return;
6881     switch (hci_stack->substate){
6882         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
6883         case HCI_HALTING_CLOSE:
6884             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
6885             break;
6886         default:
6887             break;
6888     }
6889 }
6890 
6891 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
6892 void hci_load_le_device_db_entry_into_resolving_list(uint16_t le_device_db_index){
6893     if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6894     if (le_device_db_index >= le_device_db_max_count()) return;
6895     uint8_t offset = le_device_db_index >> 3;
6896     uint8_t mask = 1 << (le_device_db_index & 7);
6897     hci_stack->le_resolving_list_add_entries[offset] |= mask;
6898     if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6899     	// note: go back to remove entries, otherwise, a remove + add will skip the add
6900         hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6901     }
6902 }
6903 
6904 void hci_remove_le_device_db_entry_from_resolving_list(uint16_t le_device_db_index){
6905 	if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6906 	if (le_device_db_index >= le_device_db_max_count()) return;
6907 	uint8_t offset = le_device_db_index >> 3;
6908 	uint8_t mask = 1 << (le_device_db_index & 7);
6909 	hci_stack->le_resolving_list_remove_entries[offset] |= mask;
6910 	if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6911 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6912 	}
6913 }
6914 
6915 uint8_t gap_load_resolving_list_from_le_device_db(void){
6916 	if ((hci_stack->local_supported_commands[1] & (1 << 2)) == 0) {
6917 		return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
6918 	}
6919 	if (hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION){
6920 		// restart le resolving list update
6921 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
6922 	}
6923 	return ERROR_CODE_SUCCESS;
6924 }
6925 #endif
6926 
6927 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
6928 void hci_setup_test_connections_fuzz(void){
6929     hci_connection_t * conn;
6930 
6931     // default address: 66:55:44:33:00:01
6932     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
6933 
6934     // setup Controller info
6935     hci_stack->num_cmd_packets = 255;
6936     hci_stack->acl_packets_total_num = 255;
6937 
6938     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
6939     addr[5] = 0x01;
6940     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6941     conn->con_handle = addr[5];
6942     conn->role  = HCI_ROLE_SLAVE;
6943     conn->state = RECEIVED_CONNECTION_REQUEST;
6944     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6945 
6946     // setup incoming Classic SCO connection with con handle 0x0002
6947     addr[5] = 0x02;
6948     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6949     conn->con_handle = addr[5];
6950     conn->role  = HCI_ROLE_SLAVE;
6951     conn->state = RECEIVED_CONNECTION_REQUEST;
6952     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6953 
6954     // setup ready Classic ACL connection with con handle 0x0003
6955     addr[5] = 0x03;
6956     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6957     conn->con_handle = addr[5];
6958     conn->role  = HCI_ROLE_SLAVE;
6959     conn->state = OPEN;
6960     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6961 
6962     // setup ready Classic SCO connection with con handle 0x0004
6963     addr[5] = 0x04;
6964     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6965     conn->con_handle = addr[5];
6966     conn->role  = HCI_ROLE_SLAVE;
6967     conn->state = OPEN;
6968     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6969 
6970     // setup ready LE ACL connection with con handle 0x005 and public address
6971     addr[5] = 0x05;
6972     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
6973     conn->con_handle = addr[5];
6974     conn->role  = HCI_ROLE_SLAVE;
6975     conn->state = OPEN;
6976     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6977     conn->sm_connection.sm_connection_encrypted = 1;
6978 }
6979 
6980 void hci_free_connections_fuzz(void){
6981     btstack_linked_list_iterator_t it;
6982     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6983     while (btstack_linked_list_iterator_has_next(&it)){
6984         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6985         btstack_linked_list_iterator_remove(&it);
6986         btstack_memory_hci_connection_free(con);
6987     }
6988 }
6989 void hci_simulate_working_fuzz(void){
6990     hci_init_done();
6991     hci_stack->num_cmd_packets = 255;
6992 }
6993 #endif
6994