xref: /btstack/src/hci.c (revision 59d59ecfa4121af665436066144b11a47ef5a52a)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hci.c"
39 
40 /*
41  *  hci.c
42  *
43  *  Created by Matthias Ringwald on 4/29/09.
44  *
45  */
46 
47 #include "btstack_config.h"
48 
49 
50 #ifdef ENABLE_CLASSIC
51 #ifdef HAVE_EMBEDDED_TICK
52 #include "btstack_run_loop_embedded.h"
53 #endif
54 #endif
55 
56 #ifdef HAVE_PLATFORM_IPHONE_OS
57 #include "../port/ios/src/btstack_control_iphone.h"
58 #endif
59 
60 #ifdef ENABLE_BLE
61 #include "gap.h"
62 #include "ble/le_device_db.h"
63 #endif
64 
65 #include <stdarg.h>
66 #include <string.h>
67 #include <inttypes.h>
68 
69 #include "btstack_debug.h"
70 #include "btstack_event.h"
71 #include "btstack_linked_list.h"
72 #include "btstack_memory.h"
73 #include "bluetooth_company_id.h"
74 #include "bluetooth_data_types.h"
75 #include "gap.h"
76 #include "hci.h"
77 #include "hci_cmd.h"
78 #include "hci_dump.h"
79 #include "ad_parser.h"
80 
81 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
82 #ifndef HCI_HOST_ACL_PACKET_NUM
83 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
84 #endif
85 #ifndef HCI_HOST_ACL_PACKET_LEN
86 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
87 #endif
88 #ifndef HCI_HOST_SCO_PACKET_NUM
89 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
90 #endif
91 #ifndef HCI_HOST_SCO_PACKET_LEN
92 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
93 #endif
94 #endif
95 
96 #if defined(ENABLE_SCO_OVER_HCI) && defined(ENABLE_SCO_OVER_PCM)
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 ENABLE_SCO_OVER_PCM."
98 #endif
99 
100 #if defined(ENABLE_SCO_OVER_HCI) && defined(HAVE_SCO_TRANSPORT)
101 #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."
102 #endif
103 
104 #define HCI_CONNECTION_TIMEOUT_MS 10000
105 
106 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
107 #define HCI_RESET_RESEND_TIMEOUT_MS 200
108 #endif
109 
110 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
111 #ifndef GAP_INQUIRY_MAX_NAME_LEN
112 #define GAP_INQUIRY_MAX_NAME_LEN 32
113 #endif
114 
115 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
116 #define GAP_INQUIRY_DURATION_MIN       0x01
117 #define GAP_INQUIRY_DURATION_MAX       0x30
118 #define GAP_INQUIRY_STATE_IDLE         0x00
119 #define GAP_INQUIRY_STATE_W4_ACTIVE    0x80
120 #define GAP_INQUIRY_STATE_ACTIVE       0x81
121 #define GAP_INQUIRY_STATE_W2_CANCEL    0x82
122 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x83
123 
124 // GAP Remote Name Request
125 #define GAP_REMOTE_NAME_STATE_IDLE 0
126 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
127 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
128 
129 // GAP Pairing
130 #define GAP_PAIRING_STATE_IDLE                       0
131 #define GAP_PAIRING_STATE_SEND_PIN                   1
132 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
133 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
134 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
135 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
136 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
137 #define GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE  7
138 
139 // prototypes
140 #ifdef ENABLE_CLASSIC
141 static void hci_update_scan_enable(void);
142 static void hci_emit_discoverable_enabled(uint8_t enabled);
143 static int  hci_local_ssp_activated(void);
144 static bool hci_remote_ssp_supported(hci_con_handle_t con_handle);
145 static bool hci_ssp_supported(hci_connection_t * connection);
146 static void hci_notify_if_sco_can_send_now(void);
147 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
148 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
149 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
150 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
151 static void hci_connection_timestamp(hci_connection_t *connection);
152 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
153 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
154 #endif
155 
156 static int  hci_power_control_on(void);
157 static void hci_power_control_off(void);
158 static void hci_state_reset(void);
159 static void hci_emit_transport_packet_sent(void);
160 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
161 static void hci_emit_nr_connections_changed(void);
162 static void hci_emit_hci_open_failed(void);
163 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
164 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
165 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
166 static void hci_run(void);
167 static int  hci_is_le_connection(hci_connection_t * connection);
168 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
169 
170 #ifdef ENABLE_CLASSIC
171 static int hci_have_usb_transport(void);
172 #endif
173 
174 #ifdef ENABLE_BLE
175 #ifdef ENABLE_LE_CENTRAL
176 // called from test/ble_client/advertising_data_parser.c
177 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
178 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address);
179 static hci_connection_t * gap_get_outgoing_connection(void);
180 #endif
181 #endif
182 
183 // the STACK is here
184 #ifndef HAVE_MALLOC
185 static hci_stack_t   hci_stack_static;
186 #endif
187 static hci_stack_t * hci_stack = NULL;
188 
189 #ifdef ENABLE_CLASSIC
190 // default name
191 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
192 
193 // test helper
194 static uint8_t disable_l2cap_timeouts = 0;
195 #endif
196 
197 /**
198  * create connection for given address
199  *
200  * @return connection OR NULL, if no memory left
201  */
202 static hci_connection_t * create_connection_for_bd_addr_and_type(const bd_addr_t addr, bd_addr_type_t addr_type){
203     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
204     hci_connection_t * conn = btstack_memory_hci_connection_get();
205     if (!conn) return NULL;
206     bd_addr_copy(conn->address, addr);
207     conn->role = HCI_ROLE_INVALID;
208     conn->address_type = addr_type;
209     conn->con_handle = 0xffff;
210     conn->authentication_flags = AUTH_FLAG_NONE;
211     conn->bonding_flags = 0;
212     conn->requested_security_level = LEVEL_0;
213 #ifdef ENABLE_CLASSIC
214     conn->request_role = HCI_ROLE_INVALID;
215     conn->sniff_subrating_max_latency = 0xffff;
216     conn->qos_service_type = HCI_SERVICE_TYPE_INVALID;
217     conn->link_key_type = INVALID_LINK_KEY;
218     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
219     btstack_run_loop_set_timer_context(&conn->timeout, conn);
220     hci_connection_timestamp(conn);
221 #endif
222     conn->acl_recombination_length = 0;
223     conn->acl_recombination_pos = 0;
224     conn->num_packets_sent = 0;
225 
226     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
227 #ifdef ENABLE_BLE
228     conn->le_phy_update_all_phys = 0xff;
229 #endif
230 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
231     conn->le_max_tx_octets = 27;
232 #endif
233     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
234     return conn;
235 }
236 
237 
238 /**
239  * get le connection parameter range
240 *
241  * @return le connection parameter range struct
242  */
243 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
244     *range = hci_stack->le_connection_parameter_range;
245 }
246 
247 /**
248  * set le connection parameter range
249  *
250  */
251 
252 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
253     hci_stack->le_connection_parameter_range = *range;
254 }
255 
256 /**
257  * @brief Test if connection parameters are inside in existing rage
258  * @param conn_interval_min (unit: 1.25ms)
259  * @param conn_interval_max (unit: 1.25ms)
260  * @param conn_latency
261  * @param supervision_timeout (unit: 10ms)
262  * @returns 1 if included
263  */
264 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){
265     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
266     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
267 
268     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
269     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
270 
271     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
272     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
273 
274     return 1;
275 }
276 
277 /**
278  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
279  * @note: default: 1
280  * @param max_peripheral_connections
281  */
282 #ifdef ENABLE_LE_PERIPHERAL
283 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
284     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
285 }
286 #endif
287 
288 /**
289  * get hci connections iterator
290  *
291  * @return hci connections iterator
292  */
293 
294 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
295     btstack_linked_list_iterator_init(it, &hci_stack->connections);
296 }
297 
298 /**
299  * get connection for a given handle
300  *
301  * @return connection OR NULL, if not found
302  */
303 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
304     btstack_linked_list_iterator_t it;
305     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
306     while (btstack_linked_list_iterator_has_next(&it)){
307         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
308         if ( item->con_handle == con_handle ) {
309             return item;
310         }
311     }
312     return NULL;
313 }
314 
315 /**
316  * get connection for given address
317  *
318  * @return connection OR NULL, if not found
319  */
320 hci_connection_t * hci_connection_for_bd_addr_and_type(const bd_addr_t  addr, bd_addr_type_t addr_type){
321     btstack_linked_list_iterator_t it;
322     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
323     while (btstack_linked_list_iterator_has_next(&it)){
324         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
325         if (connection->address_type != addr_type)  continue;
326         if (memcmp(addr, connection->address, 6) != 0) continue;
327         return connection;
328     }
329     return NULL;
330 }
331 
332 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
333     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
334 }
335 
336 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
337     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
338 }
339 
340 #ifdef ENABLE_CLASSIC
341 
342 #ifdef ENABLE_SCO_OVER_HCI
343 static int hci_number_sco_connections(void){
344     int connections = 0;
345     btstack_linked_list_iterator_t it;
346     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
347     while (btstack_linked_list_iterator_has_next(&it)){
348         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
349         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
350         connections++;
351     }
352     return connections;
353 }
354 #endif
355 
356 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
357     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
358 #ifdef HAVE_EMBEDDED_TICK
359     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
360         // connections might be timed out
361         hci_emit_l2cap_check_timeout(connection);
362     }
363 #else
364     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
365         // connections might be timed out
366         hci_emit_l2cap_check_timeout(connection);
367     }
368 #endif
369 }
370 
371 static void hci_connection_timestamp(hci_connection_t *connection){
372 #ifdef HAVE_EMBEDDED_TICK
373     connection->timestamp = btstack_run_loop_embedded_get_ticks();
374 #else
375     connection->timestamp = btstack_run_loop_get_time_ms();
376 #endif
377 }
378 
379 /**
380  * add authentication flags and reset timer
381  * @note: assumes classic connection
382  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
383  */
384 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
385     bd_addr_t addr;
386     reverse_bd_addr(bd_addr, addr);
387     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
388     if (conn) {
389         connectionSetAuthenticationFlags(conn, flags);
390         hci_connection_timestamp(conn);
391     }
392 }
393 
394 static bool hci_pairing_active(hci_connection_t * hci_connection){
395     return (hci_connection->authentication_flags & AUTH_FLAG_PAIRING_ACTIVE_MASK) != 0;
396 }
397 
398 static void hci_pairing_started(hci_connection_t * hci_connection, bool ssp){
399     if (hci_pairing_active(hci_connection)) return;
400     if (ssp){
401         hci_connection->authentication_flags |= AUTH_FLAG_SSP_PAIRING_ACTIVE;
402     } else {
403         hci_connection->authentication_flags |= AUTH_FLAG_LEGACY_PAIRING_ACTIVE;
404     }
405     // if we are initiator, we have sent an HCI Authenticate Request
406     bool initiator = (hci_connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0;
407 
408     // if we are responder, use minimal service security level as required level
409     if (!initiator){
410         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);
411     }
412 
413     log_info("pairing started, ssp %u, initiator %u, requested level %u", (int) ssp, (int) initiator, hci_connection->requested_security_level);
414 
415     uint8_t event[12];
416     event[0] = GAP_EVENT_PAIRING_STARTED;
417     event[1] = 10;
418     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
419     reverse_bd_addr(hci_connection->address, &event[4]);
420     event[10] = (uint8_t) ssp;
421     event[11] = (uint8_t) initiator;
422     hci_emit_event(event, sizeof(event), 1);
423 }
424 
425 static void hci_pairing_complete(hci_connection_t * hci_connection, uint8_t status){
426     hci_connection->requested_security_level = LEVEL_0;
427     if (!hci_pairing_active(hci_connection)) return;
428     hci_connection->authentication_flags &= ~AUTH_FLAG_PAIRING_ACTIVE_MASK;
429     log_info("pairing complete, status %02x", status);
430 
431     uint8_t event[12];
432     event[0] = GAP_EVENT_PAIRING_COMPLETE;
433     event[1] = 9;
434     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
435     reverse_bd_addr(hci_connection->address, &event[4]);
436     event[10] = status;
437     hci_emit_event(event, sizeof(event), 1);
438 }
439 
440 bool hci_authentication_active_for_handle(hci_con_handle_t handle){
441     hci_connection_t * conn = hci_connection_for_handle(handle);
442     if (!conn) return false;
443     return hci_pairing_active(conn);
444 }
445 
446 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
447     if (!hci_stack->link_key_db) return;
448     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
449     hci_stack->link_key_db->delete_link_key(addr);
450 }
451 
452 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
453     if (!hci_stack->link_key_db) return;
454     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
455     hci_stack->link_key_db->put_link_key(addr, link_key, type);
456 }
457 
458 bool gap_get_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t * type){
459 	if (!hci_stack->link_key_db) return false;
460 	int result = hci_stack->link_key_db->get_link_key(addr, link_key, type) != 0;
461 	log_info("link key for %s available %u, type %u", bd_addr_to_str(addr), result, (int) *type);
462 	return result;
463 }
464 
465 void gap_delete_all_link_keys(void){
466     bd_addr_t  addr;
467     link_key_t link_key;
468     link_key_type_t type;
469     btstack_link_key_iterator_t it;
470     int ok = gap_link_key_iterator_init(&it);
471     if (!ok) {
472         log_error("could not initialize iterator");
473         return;
474     }
475     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
476         gap_drop_link_key_for_bd_addr(addr);
477     }
478     gap_link_key_iterator_done(&it);
479 }
480 
481 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
482     if (!hci_stack->link_key_db) return 0;
483     if (!hci_stack->link_key_db->iterator_init) return 0;
484     return hci_stack->link_key_db->iterator_init(it);
485 }
486 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){
487     if (!hci_stack->link_key_db) return 0;
488     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
489 }
490 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
491     if (!hci_stack->link_key_db) return;
492     hci_stack->link_key_db->iterator_done(it);
493 }
494 #endif
495 
496 static bool hci_is_le_connection_type(bd_addr_type_t address_type){
497     switch (address_type){
498         case BD_ADDR_TYPE_LE_PUBLIC:
499         case BD_ADDR_TYPE_LE_RANDOM:
500         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
501         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
502             return true;
503         default:
504             return false;
505     }
506 }
507 
508 static int hci_is_le_connection(hci_connection_t * connection){
509     return hci_is_le_connection_type(connection->address_type);
510 }
511 
512 /**
513  * count connections
514  */
515 static int nr_hci_connections(void){
516     int count = 0;
517     btstack_linked_item_t *it;
518     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
519         count++;
520     }
521     return count;
522 }
523 
524 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
525 
526     unsigned int num_packets_sent_classic = 0;
527     unsigned int num_packets_sent_le = 0;
528 
529     btstack_linked_item_t *it;
530     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
531         hci_connection_t * connection = (hci_connection_t *) it;
532         if (hci_is_le_connection(connection)){
533             num_packets_sent_le += connection->num_packets_sent;
534         }
535         if (connection->address_type == BD_ADDR_TYPE_ACL){
536             num_packets_sent_classic += connection->num_packets_sent;
537         }
538     }
539     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
540     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
541     int free_slots_le = 0;
542 
543     if (free_slots_classic < 0){
544         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);
545         return 0;
546     }
547 
548     if (hci_stack->le_acl_packets_total_num){
549         // if we have LE slots, they are used
550         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
551         if (free_slots_le < 0){
552             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);
553             return 0;
554         }
555     } else {
556         // otherwise, classic slots are used for LE, too
557         free_slots_classic -= num_packets_sent_le;
558         if (free_slots_classic < 0){
559             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);
560             return 0;
561         }
562     }
563 
564     switch (address_type){
565         case BD_ADDR_TYPE_UNKNOWN:
566             log_error("hci_number_free_acl_slots: unknown address type");
567             return 0;
568 
569         case BD_ADDR_TYPE_ACL:
570             return free_slots_classic;
571 
572         default:
573            if (hci_stack->le_acl_packets_total_num){
574                return free_slots_le;
575            }
576            return free_slots_classic;
577     }
578 }
579 
580 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
581     // get connection type
582     hci_connection_t * connection = hci_connection_for_handle(con_handle);
583     if (!connection){
584         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
585         return 0;
586     }
587     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
588 }
589 
590 #ifdef ENABLE_CLASSIC
591 static int hci_number_free_sco_slots(void){
592     unsigned int num_sco_packets_sent  = 0;
593     btstack_linked_item_t *it;
594     if (hci_stack->synchronous_flow_control_enabled){
595         // explicit flow control
596         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
597             hci_connection_t * connection = (hci_connection_t *) it;
598             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
599             num_sco_packets_sent += connection->num_packets_sent;
600         }
601         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
602             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
603             return 0;
604         }
605         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
606     } else {
607         // implicit flow control -- TODO
608         int num_ready = 0;
609         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
610             hci_connection_t * connection = (hci_connection_t *) it;
611             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
612             if (connection->sco_tx_ready == 0) continue;
613             num_ready++;
614         }
615         return num_ready;
616     }
617 }
618 #endif
619 
620 // only used to send HCI Host Number Completed Packets
621 static int hci_can_send_comand_packet_transport(void){
622     if (hci_stack->hci_packet_buffer_reserved) return 0;
623 
624     // check for async hci transport implementations
625     if (hci_stack->hci_transport->can_send_packet_now){
626         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
627             return 0;
628         }
629     }
630     return 1;
631 }
632 
633 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
634 bool hci_can_send_command_packet_now(void){
635     if (hci_can_send_comand_packet_transport() == 0) return false;
636     return hci_stack->num_cmd_packets > 0u;
637 }
638 
639 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
640     // check for async hci transport implementations
641     if (!hci_stack->hci_transport->can_send_packet_now) return true;
642     return hci_stack->hci_transport->can_send_packet_now(packet_type);
643 }
644 
645 static bool hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
646     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
647     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
648 }
649 
650 bool hci_can_send_acl_le_packet_now(void){
651     if (hci_stack->hci_packet_buffer_reserved) return false;
652     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
653 }
654 
655 bool hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
656     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
657     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
658 }
659 
660 bool hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
661     if (hci_stack->hci_packet_buffer_reserved) return false;
662     return hci_can_send_prepared_acl_packet_now(con_handle);
663 }
664 
665 #ifdef ENABLE_CLASSIC
666 bool hci_can_send_acl_classic_packet_now(void){
667     if (hci_stack->hci_packet_buffer_reserved) return false;
668     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
669 }
670 
671 bool hci_can_send_prepared_sco_packet_now(void){
672     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return false;
673     if (hci_have_usb_transport()){
674         return hci_stack->sco_can_send_now;
675     } else {
676         return hci_number_free_sco_slots() > 0;
677     }
678 }
679 
680 bool hci_can_send_sco_packet_now(void){
681     if (hci_stack->hci_packet_buffer_reserved) return false;
682     return hci_can_send_prepared_sco_packet_now();
683 }
684 
685 void hci_request_sco_can_send_now_event(void){
686     hci_stack->sco_waiting_for_can_send_now = 1;
687     hci_notify_if_sco_can_send_now();
688 }
689 #endif
690 
691 // used for internal checks in l2cap.c
692 bool hci_is_packet_buffer_reserved(void){
693     return hci_stack->hci_packet_buffer_reserved;
694 }
695 
696 // reserves outgoing packet buffer. @returns 1 if successful
697 bool hci_reserve_packet_buffer(void){
698     if (hci_stack->hci_packet_buffer_reserved) {
699         log_error("hci_reserve_packet_buffer called but buffer already reserved");
700         return false;
701     }
702     hci_stack->hci_packet_buffer_reserved = true;
703     return true;
704 }
705 
706 void hci_release_packet_buffer(void){
707     hci_stack->hci_packet_buffer_reserved = false;
708 }
709 
710 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
711 static int hci_transport_synchronous(void){
712     return hci_stack->hci_transport->can_send_packet_now == NULL;
713 }
714 
715 static uint8_t hci_send_acl_packet_fragments(hci_connection_t *connection){
716 
717     // 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);
718 
719     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
720     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
721     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0u)){
722         max_acl_data_packet_length = hci_stack->le_data_packets_length;
723     }
724 
725 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
726     if (hci_is_le_connection(connection) && (connection->le_max_tx_octets < max_acl_data_packet_length)){
727         max_acl_data_packet_length = connection->le_max_tx_octets;
728     }
729 #endif
730 
731     log_debug("hci_send_acl_packet_fragments entered");
732 
733     uint8_t status = ERROR_CODE_SUCCESS;
734     // multiple packets could be send on a synchronous HCI transport
735     while (true){
736 
737         log_debug("hci_send_acl_packet_fragments loop entered");
738 
739         // get current data
740         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4u;
741         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
742         bool more_fragments = false;
743 
744         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
745         if (current_acl_data_packet_length > max_acl_data_packet_length){
746             more_fragments = true;
747             current_acl_data_packet_length = max_acl_data_packet_length;
748         }
749 
750         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
751         if (acl_header_pos > 0u){
752             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
753             handle_and_flags = (handle_and_flags & 0xcfffu) | (1u << 12u);
754             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
755         }
756 
757         // update header len
758         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2u, current_acl_data_packet_length);
759 
760         // count packet
761         connection->num_packets_sent++;
762         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", (int) more_fragments);
763 
764         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
765         if (more_fragments){
766             // update start of next fragment to send
767             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
768         } else {
769             // done
770             hci_stack->acl_fragmentation_pos = 0;
771             hci_stack->acl_fragmentation_total_size = 0;
772         }
773 
774         // send packet
775         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
776         const int size = current_acl_data_packet_length + 4;
777         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
778         hci_stack->acl_fragmentation_tx_active = 1;
779         int err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
780         if (err != 0){
781             // no error from HCI Transport expected
782             status = ERROR_CODE_HARDWARE_FAILURE;
783         }
784 
785         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", (int) more_fragments);
786 
787         // done yet?
788         if (!more_fragments) break;
789 
790         // can send more?
791         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return status;
792     }
793 
794     log_debug("hci_send_acl_packet_fragments loop over");
795 
796     // release buffer now for synchronous transport
797     if (hci_transport_synchronous()){
798         hci_stack->acl_fragmentation_tx_active = 0;
799         hci_release_packet_buffer();
800         hci_emit_transport_packet_sent();
801     }
802 
803     return status;
804 }
805 
806 // pre: caller has reserved the packet buffer
807 uint8_t hci_send_acl_packet_buffer(int size){
808     btstack_assert(hci_stack->hci_packet_buffer_reserved);
809 
810     uint8_t * packet = hci_stack->hci_packet_buffer;
811     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
812 
813     // check for free places on Bluetooth module
814     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
815         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
816         hci_release_packet_buffer();
817         hci_emit_transport_packet_sent();
818         return BTSTACK_ACL_BUFFERS_FULL;
819     }
820 
821     hci_connection_t *connection = hci_connection_for_handle( con_handle);
822     if (!connection) {
823         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
824         hci_release_packet_buffer();
825         hci_emit_transport_packet_sent();
826         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
827     }
828 
829 #ifdef ENABLE_CLASSIC
830     hci_connection_timestamp(connection);
831 #endif
832 
833     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
834 
835     // setup data
836     hci_stack->acl_fragmentation_total_size = size;
837     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
838 
839     return hci_send_acl_packet_fragments(connection);
840 }
841 
842 #ifdef ENABLE_CLASSIC
843 // pre: caller has reserved the packet buffer
844 uint8_t hci_send_sco_packet_buffer(int size){
845     btstack_assert(hci_stack->hci_packet_buffer_reserved);
846 
847     uint8_t * packet = hci_stack->hci_packet_buffer;
848 
849     // skip checks in loopback mode
850     if (!hci_stack->loopback_mode){
851         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
852 
853         // check for free places on Bluetooth module
854         if (!hci_can_send_prepared_sco_packet_now()) {
855             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
856             hci_release_packet_buffer();
857             hci_emit_transport_packet_sent();
858             return BTSTACK_ACL_BUFFERS_FULL;
859         }
860 
861         // track send packet in connection struct
862         hci_connection_t *connection = hci_connection_for_handle( con_handle);
863         if (!connection) {
864             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
865             hci_release_packet_buffer();
866             hci_emit_transport_packet_sent();
867             return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
868         }
869 
870         if (hci_have_usb_transport()){
871             // token used
872             hci_stack->sco_can_send_now = false;
873         } else {
874             if (hci_stack->synchronous_flow_control_enabled){
875                 connection->num_packets_sent++;
876             } else {
877                 connection->sco_tx_ready--;
878             }
879         }
880     }
881 
882     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
883 
884 #ifdef HAVE_SCO_TRANSPORT
885     hci_stack->sco_transport->send_packet(packet, size);
886     hci_release_packet_buffer();
887     hci_emit_transport_packet_sent();
888 
889     return 0;
890 #else
891     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
892     if (hci_transport_synchronous()){
893         hci_release_packet_buffer();
894         hci_emit_transport_packet_sent();
895     }
896 
897     if (err != 0){
898         return ERROR_CODE_HARDWARE_FAILURE;
899     }
900     return ERROR_CODE_SUCCESS;
901 #endif
902 }
903 #endif
904 
905 static void acl_handler(uint8_t *packet, uint16_t size){
906 
907     // get info
908     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
909     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
910     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
911     uint16_t acl_length         = READ_ACL_LENGTH(packet);
912 
913     // ignore non-registered handle
914     if (!conn){
915         log_error("acl_handler called with non-registered handle %u!" , con_handle);
916         return;
917     }
918 
919     // assert packet is complete
920     if ((acl_length + 4u) != size){
921         log_error("acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
922         return;
923     }
924 
925 #ifdef ENABLE_CLASSIC
926     // update idle timestamp
927     hci_connection_timestamp(conn);
928 #endif
929 
930 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
931     hci_stack->host_completed_packets = 1;
932     conn->num_packets_completed++;
933 #endif
934 
935     // handle different packet types
936     switch (acl_flags & 0x03u) {
937 
938         case 0x01: // continuation fragment
939 
940             // sanity checks
941             if (conn->acl_recombination_pos == 0u) {
942                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
943                 return;
944             }
945             if ((conn->acl_recombination_pos + acl_length) > (4u + HCI_ACL_BUFFER_SIZE)){
946                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
947                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
948                 conn->acl_recombination_pos = 0;
949                 return;
950             }
951 
952             // append fragment payload (header already stored)
953             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
954                          &packet[4], acl_length);
955             conn->acl_recombination_pos += acl_length;
956 
957             // forward complete L2CAP packet if complete.
958             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4u + 4u)){ // pos already incl. ACL header
959                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
960                 // reset recombination buffer
961                 conn->acl_recombination_length = 0;
962                 conn->acl_recombination_pos = 0;
963             }
964             break;
965 
966         case 0x02: { // first fragment
967 
968             // sanity check
969             if (conn->acl_recombination_pos) {
970                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
971                 conn->acl_recombination_pos = 0;
972             }
973 
974             // peek into L2CAP packet!
975             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
976 
977             // compare fragment size to L2CAP packet size
978             if (acl_length >= (l2cap_length + 4u)){
979                 // forward fragment as L2CAP packet
980                 hci_emit_acl_packet(packet, acl_length + 4u);
981             } else {
982 
983                 if (acl_length > HCI_ACL_BUFFER_SIZE){
984                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
985                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
986                     return;
987                 }
988 
989                 // store first fragment and tweak acl length for complete package
990                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
991                              packet, acl_length + 4u);
992                 conn->acl_recombination_pos    = acl_length + 4u;
993                 conn->acl_recombination_length = l2cap_length;
994                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2u, l2cap_length +4u);
995             }
996             break;
997 
998         }
999         default:
1000             log_error( "acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
1001             return;
1002     }
1003 
1004     // execute main loop
1005     hci_run();
1006 }
1007 
1008 static void hci_shutdown_connection(hci_connection_t *conn){
1009     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
1010 
1011 #ifdef ENABLE_CLASSIC
1012 #if defined(ENABLE_SCO_OVER_HCI) || defined(HAVE_SCO_TRANSPORT)
1013     bd_addr_type_t addr_type = conn->address_type;
1014 #endif
1015 #ifdef HAVE_SCO_TRANSPORT
1016     hci_con_handle_t con_handle = conn->con_handle;
1017 #endif
1018 #endif
1019 
1020     btstack_run_loop_remove_timer(&conn->timeout);
1021 
1022     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1023     btstack_memory_hci_connection_free( conn );
1024 
1025     // now it's gone
1026     hci_emit_nr_connections_changed();
1027 
1028 #ifdef ENABLE_CLASSIC
1029 #ifdef ENABLE_SCO_OVER_HCI
1030     // update SCO
1031     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->hci_transport != NULL) && (hci_stack->hci_transport->set_sco_config != NULL)){
1032         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
1033     }
1034 #endif
1035 #ifdef HAVE_SCO_TRANSPORT
1036     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->sco_transport != NULL)){
1037         hci_stack->sco_transport->close(con_handle);
1038     }
1039 #endif
1040 #endif
1041 }
1042 
1043 #ifdef ENABLE_CLASSIC
1044 
1045 static const uint16_t packet_type_sizes[] = {
1046     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
1047     HCI_ACL_DH1_SIZE, 0, 0, 0,
1048     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
1049     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
1050 };
1051 static const uint8_t  packet_type_feature_requirement_bit[] = {
1052      0, // 3 slot packets
1053      1, // 5 slot packets
1054     25, // EDR 2 mpbs
1055     26, // EDR 3 mbps
1056     39, // 3 slot EDR packts
1057     40, // 5 slot EDR packet
1058 };
1059 static const uint16_t packet_type_feature_packet_mask[] = {
1060     0x0f00, // 3 slot packets
1061     0xf000, // 5 slot packets
1062     0x1102, // EDR 2 mpbs
1063     0x2204, // EDR 3 mbps
1064     0x0300, // 3 slot EDR packts
1065     0x3000, // 5 slot EDR packet
1066 };
1067 
1068 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
1069     // enable packet types based on size
1070     uint16_t packet_types = 0;
1071     unsigned int i;
1072     for (i=0;i<16;i++){
1073         if (packet_type_sizes[i] == 0) continue;
1074         if (packet_type_sizes[i] <= buffer_size){
1075             packet_types |= 1 << i;
1076         }
1077     }
1078     // disable packet types due to missing local supported features
1079     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1080         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1081         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1082         if (feature_set) continue;
1083         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1084         packet_types &= ~packet_type_feature_packet_mask[i];
1085     }
1086     // flip bits for "may not be used"
1087     packet_types ^= 0x3306;
1088     return packet_types;
1089 }
1090 
1091 uint16_t hci_usable_acl_packet_types(void){
1092     return hci_stack->packet_types;
1093 }
1094 #endif
1095 
1096 uint8_t* hci_get_outgoing_packet_buffer(void){
1097     // hci packet buffer is >= acl data packet length
1098     return hci_stack->hci_packet_buffer;
1099 }
1100 
1101 uint16_t hci_max_acl_data_packet_length(void){
1102     return hci_stack->acl_data_packet_length;
1103 }
1104 
1105 #ifdef ENABLE_CLASSIC
1106 bool hci_extended_sco_link_supported(void){
1107     // No. 31, byte 3, bit 7
1108     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1109 }
1110 #endif
1111 
1112 bool hci_non_flushable_packet_boundary_flag_supported(void){
1113     // No. 54, byte 6, bit 6
1114     return (hci_stack->local_supported_features[6u] & (1u << 6u)) != 0u;
1115 }
1116 
1117 static int gap_ssp_supported(void){
1118     // No. 51, byte 6, bit 3
1119     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1120 }
1121 
1122 static int hci_classic_supported(void){
1123 #ifdef ENABLE_CLASSIC
1124     // No. 37, byte 4, bit 5, = No BR/EDR Support
1125     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1126 #else
1127     return 0;
1128 #endif
1129 }
1130 
1131 static int hci_le_supported(void){
1132 #ifdef ENABLE_BLE
1133     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1134     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1135 #else
1136     return 0;
1137 #endif
1138 }
1139 
1140 #ifdef ENABLE_BLE
1141 
1142 static void hci_get_own_address_for_addr_type(uint8_t own_addr_type, bd_addr_t own_addr){
1143     if (own_addr_type == BD_ADDR_TYPE_LE_PUBLIC){
1144         (void)memcpy(own_addr, hci_stack->local_bd_addr, 6);
1145     } else {
1146         (void)memcpy(own_addr, hci_stack->le_random_address, 6);
1147     }
1148 }
1149 
1150 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1151     *addr_type = hci_stack->le_own_addr_type;
1152     hci_get_own_address_for_addr_type(hci_stack->le_own_addr_type, addr);
1153 }
1154 
1155 #ifdef ENABLE_LE_PERIPHERAL
1156 void gap_le_get_own_advertisements_address(uint8_t * addr_type, bd_addr_t addr){
1157     *addr_type = hci_stack->le_advertisements_own_addr_type;
1158     hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, addr);
1159 };
1160 #endif
1161 
1162 #ifdef ENABLE_LE_CENTRAL
1163 
1164 /**
1165  * @brief Get own addr type and address used for LE connections (Central)
1166  */
1167 void gap_le_get_own_connection_address(uint8_t * addr_type, bd_addr_t addr){
1168     *addr_type = hci_stack->le_connection_own_addr_type;
1169     hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, addr);
1170 }
1171 
1172 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1173 
1174     int offset = 3;
1175     int num_reports = packet[offset];
1176     offset += 1;
1177 
1178     int i;
1179     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1180     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1181     for (i=0; (i<num_reports) && (offset < size);i++){
1182         // sanity checks on data_length:
1183         uint8_t data_length = packet[offset + 8];
1184         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1185         if ((offset + 9u + data_length + 1u) > size)    return;
1186         // setup event
1187         uint8_t event_size = 10u + data_length;
1188         int pos = 0;
1189         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1190         event[pos++] = event_size;
1191         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1192         offset += 8;
1193         pos += 8;
1194         event[pos++] = packet[offset + 1 + data_length]; // rssi
1195         event[pos++] = data_length;
1196         offset++;
1197         (void)memcpy(&event[pos], &packet[offset], data_length);
1198         pos +=    data_length;
1199         offset += data_length + 1u; // rssi
1200         hci_emit_event(event, pos, 1);
1201     }
1202 }
1203 #endif
1204 #endif
1205 
1206 #ifdef ENABLE_BLE
1207 #ifdef ENABLE_LE_PERIPHERAL
1208 static void hci_update_advertisements_enabled_for_current_roles(void){
1209     if (hci_stack->le_advertisements_enabled){
1210         // get number of active le slave connections
1211         int num_slave_connections = 0;
1212         btstack_linked_list_iterator_t it;
1213         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1214         while (btstack_linked_list_iterator_has_next(&it)){
1215             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1216             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1217             if (con->state != OPEN) continue;
1218             if (con->role  != HCI_ROLE_SLAVE) continue;
1219             if (!hci_is_le_connection(con)) continue;
1220             num_slave_connections++;
1221         }
1222         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1223         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1224     } else {
1225         hci_stack->le_advertisements_enabled_for_current_roles = false;
1226     }
1227 }
1228 #endif
1229 #endif
1230 
1231 #ifdef ENABLE_CLASSIC
1232 static void gap_run_set_local_name(void){
1233     hci_reserve_packet_buffer();
1234     uint8_t * packet = hci_stack->hci_packet_buffer;
1235     // construct HCI Command and send
1236     uint16_t opcode = hci_write_local_name.opcode;
1237     hci_stack->last_cmd_opcode = opcode;
1238     packet[0] = opcode & 0xff;
1239     packet[1] = opcode >> 8;
1240     packet[2] = DEVICE_NAME_LEN;
1241     memset(&packet[3], 0, DEVICE_NAME_LEN);
1242     uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1243     uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1244     // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1245     (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1246     // expand '00:00:00:00:00:00' in name with bd_addr
1247     btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1248     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1249 }
1250 
1251 static void gap_run_set_eir_data(void){
1252     hci_reserve_packet_buffer();
1253     uint8_t * packet = hci_stack->hci_packet_buffer;
1254     // construct HCI Command in-place and send
1255     uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1256     hci_stack->last_cmd_opcode = opcode;
1257     uint16_t offset = 0;
1258     packet[offset++] = opcode & 0xff;
1259     packet[offset++] = opcode >> 8;
1260     packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1261     packet[offset++] = 0;  // FEC not required
1262     memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1263     if (hci_stack->eir_data){
1264         // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1265         ad_context_t context;
1266         for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1267             uint8_t data_type   = ad_iterator_get_data_type(&context);
1268             uint8_t size        = ad_iterator_get_data_len(&context);
1269             const uint8_t *data = ad_iterator_get_data(&context);
1270             // copy item
1271             packet[offset++] = size + 1;
1272             packet[offset++] = data_type;
1273             memcpy(&packet[offset], data, size);
1274             // update name item
1275             if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1276                 btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1277             }
1278             offset += size;
1279         }
1280     } else {
1281         uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1282         uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1283         packet[offset++] = bytes_to_copy + 1;
1284         packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1285         (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1286         // expand '00:00:00:00:00:00' in name with bd_addr
1287         btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1288     }
1289     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1290 }
1291 #endif
1292 
1293 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1294 
1295 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1296     if (!hci_stack->config) return 0;
1297     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1298     // Limit baud rate for Broadcom chipsets to 3 mbps
1299     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1300         baud_rate = 3000000;
1301     }
1302     return baud_rate;
1303 }
1304 
1305 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1306     UNUSED(ds);
1307 
1308     switch (hci_stack->substate){
1309         case HCI_INIT_W4_SEND_RESET:
1310             log_info("Resend HCI Reset");
1311             hci_stack->substate = HCI_INIT_SEND_RESET;
1312             hci_stack->num_cmd_packets = 1;
1313             hci_run();
1314             break;
1315         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1316             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1317             if (hci_stack->hci_transport->reset_link){
1318                 hci_stack->hci_transport->reset_link();
1319             }
1320 
1321             /* fall through */
1322 
1323         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1324             log_info("Resend HCI Reset - CSR Warm Boot");
1325             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1326             hci_stack->num_cmd_packets = 1;
1327             hci_run();
1328             break;
1329         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1330             if (hci_stack->hci_transport->set_baudrate){
1331                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1332                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1333                 hci_stack->hci_transport->set_baudrate(baud_rate);
1334             }
1335             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1336             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1337                 if (hci_stack->hci_transport->reset_link){
1338                     log_info("Link Reset");
1339                     hci_stack->hci_transport->reset_link();
1340                 }
1341                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1342                 hci_run();
1343             }
1344             break;
1345         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1346             // otherwise continue
1347             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1348             hci_send_cmd(&hci_read_local_supported_commands);
1349             break;
1350         default:
1351             break;
1352     }
1353 }
1354 #endif
1355 
1356 static void hci_initializing_next_state(void){
1357     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1358 }
1359 
1360 // assumption: hci_can_send_command_packet_now() == true
1361 static void hci_initializing_run(void){
1362     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1363     switch (hci_stack->substate){
1364         case HCI_INIT_SEND_RESET:
1365             hci_state_reset();
1366 
1367 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1368             // prepare reset if command complete not received in 100ms
1369             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1370             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1371             btstack_run_loop_add_timer(&hci_stack->timeout);
1372 #endif
1373             // send command
1374             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1375             hci_send_cmd(&hci_reset);
1376             break;
1377         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1378             hci_send_cmd(&hci_read_local_version_information);
1379             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1380             break;
1381         case HCI_INIT_SEND_READ_LOCAL_NAME:
1382             hci_send_cmd(&hci_read_local_name);
1383             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1384             break;
1385 
1386 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1387         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1388             hci_state_reset();
1389             // prepare reset if command complete not received in 100ms
1390             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1391             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1392             btstack_run_loop_add_timer(&hci_stack->timeout);
1393             // send command
1394             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1395             hci_send_cmd(&hci_reset);
1396             break;
1397         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1398             hci_state_reset();
1399             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1400             hci_send_cmd(&hci_reset);
1401             break;
1402         case HCI_INIT_SEND_BAUD_CHANGE: {
1403             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1404             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1405             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1406             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1407             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1408             // STLC25000D: baudrate change happens within 0.5 s after command was send,
1409             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1410             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1411                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1412                 btstack_run_loop_add_timer(&hci_stack->timeout);
1413             }
1414             break;
1415         }
1416         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1417             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1418             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1419             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1420             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1421             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1422             break;
1423         }
1424         case HCI_INIT_CUSTOM_INIT:
1425             // Custom initialization
1426             if (hci_stack->chipset && hci_stack->chipset->next_command){
1427                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1428                 bool send_cmd = false;
1429                 switch (hci_stack->chipset_result){
1430                     case BTSTACK_CHIPSET_VALID_COMMAND:
1431                         send_cmd = true;
1432                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1433                         break;
1434                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1435                         send_cmd = true;
1436                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1437                         log_info("CSR Warm Boot");
1438                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1439                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1440                         btstack_run_loop_add_timer(&hci_stack->timeout);
1441                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1442                             && hci_stack->config
1443                             && hci_stack->chipset
1444                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1445                             && hci_stack->hci_transport->set_baudrate
1446                             && hci_transport_uart_get_main_baud_rate()){
1447                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1448                         } else {
1449                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1450                         }
1451                         break;
1452                     default:
1453                         break;
1454                 }
1455 
1456                 if (send_cmd){
1457                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1458                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1459                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1460                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1461                     break;
1462                 }
1463                 log_info("Init script done");
1464 
1465                 // Init script download on Broadcom chipsets causes:
1466                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1467                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1468                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1469 
1470                     // - baud rate to reset, restore UART baud rate if needed
1471                     int need_baud_change = hci_stack->config
1472                         && hci_stack->chipset
1473                         && hci_stack->chipset->set_baudrate_command
1474                         && hci_stack->hci_transport->set_baudrate
1475                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1476                     if (need_baud_change) {
1477                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1478                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1479                         hci_stack->hci_transport->set_baudrate(baud_rate);
1480                     }
1481 
1482                     uint16_t bcm_delay_ms = 300;
1483                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1484                     //   -> Work around: wait here.
1485                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1486                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1487                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_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                     break;
1491                 }
1492             }
1493             // otherwise continue
1494             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1495             hci_send_cmd(&hci_read_local_supported_commands);
1496             break;
1497         case HCI_INIT_SET_BD_ADDR:
1498             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1499             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1500             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1501             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1502             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1503             break;
1504 #endif
1505 
1506         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1507             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1508             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1509             hci_send_cmd(&hci_read_local_supported_commands);
1510             break;
1511         case HCI_INIT_READ_BD_ADDR:
1512             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1513             hci_send_cmd(&hci_read_bd_addr);
1514             break;
1515         case HCI_INIT_READ_BUFFER_SIZE:
1516             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1517             hci_send_cmd(&hci_read_buffer_size);
1518             break;
1519         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1520             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1521             hci_send_cmd(&hci_read_local_supported_features);
1522             break;
1523 
1524 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1525         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1526             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1527             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1528             break;
1529         case HCI_INIT_HOST_BUFFER_SIZE:
1530             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1531             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1532                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1533             break;
1534 #endif
1535 
1536         case HCI_INIT_SET_EVENT_MASK:
1537             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1538             if (hci_le_supported()){
1539                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x3FFFFFFFU);
1540             } else {
1541                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1542                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x1FFFFFFFU);
1543             }
1544             break;
1545 
1546 #ifdef ENABLE_CLASSIC
1547         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1548             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1549             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1550             break;
1551         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1552             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1553             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1554             break;
1555         case HCI_INIT_WRITE_INQUIRY_MODE:
1556             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1557             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1558             break;
1559         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1560             hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1561 			hci_stack->secure_connections_active = true;
1562             hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1563             break;
1564         case HCI_INIT_WRITE_SCAN_ENABLE:
1565             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1566             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1567             break;
1568         // only sent if ENABLE_SCO_OVER_HCI is defined
1569         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1570             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1571             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1572             break;
1573         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1574             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1575             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1576             break;
1577         // only sent if manufacturer is Broadcom and ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM is defined
1578         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1579             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1580 #ifdef ENABLE_SCO_OVER_HCI
1581             log_info("BCM: Route SCO data via HCI transport");
1582             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1583 #endif
1584 #ifdef ENABLE_SCO_OVER_PCM
1585             log_info("BCM: Route SCO data via PCM interface");
1586 #ifdef ENABLE_BCM_PCM_WBS
1587             // 512 kHz bit clock for 2 channels x 16 bit x 8 kHz
1588             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 2, 0, 1, 1);
1589 #else
1590             // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1591             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 1, 0, 1, 1);
1592 #endif
1593 #endif
1594             break;
1595 #ifdef ENABLE_SCO_OVER_PCM
1596         case HCI_INIT_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
1597             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1598             log_info("BCM: Config PCM interface for I2S");
1599 #ifdef ENABLE_BCM_PCM_WBS
1600             // 512 kHz bit clock for 2 channels x 16 bit x 8 kHz
1601             hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 2);
1602 #else
1603             // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1604             hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 1);
1605 #endif
1606             break;
1607 #endif
1608 #endif
1609 
1610 #ifdef ENABLE_BLE
1611         // LE INIT
1612         case HCI_INIT_LE_READ_BUFFER_SIZE:
1613             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1614             hci_send_cmd(&hci_le_read_buffer_size);
1615             break;
1616         case HCI_INIT_LE_SET_EVENT_MASK:
1617             hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1618             hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1619             break;
1620         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1621             // LE Supported Host = 1, Simultaneous Host = 0
1622             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1623             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1624             break;
1625 #endif
1626 
1627 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1628         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1629             hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1630             hci_send_cmd(&hci_le_read_maximum_data_length);
1631             break;
1632         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1633             hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1634             hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1635             break;
1636 #endif
1637 
1638 #ifdef ENABLE_LE_CENTRAL
1639         case HCI_INIT_READ_WHITE_LIST_SIZE:
1640             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1641             hci_send_cmd(&hci_le_read_white_list_size);
1642             break;
1643         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1644             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1645             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);
1646             break;
1647 #endif
1648         default:
1649             return;
1650     }
1651 }
1652 
1653 static void hci_init_done(void){
1654     // done. tell the app
1655     log_info("hci_init_done -> HCI_STATE_WORKING");
1656     hci_stack->state = HCI_STATE_WORKING;
1657     hci_emit_state();
1658     hci_run();
1659 }
1660 
1661 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1662     bool command_completed = false;
1663     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1664         uint16_t opcode = little_endian_read_16(packet,3);
1665         if (opcode == hci_stack->last_cmd_opcode){
1666             command_completed = true;
1667             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1668         } else {
1669             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1670         }
1671     }
1672 
1673     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1674         uint8_t  status = packet[2];
1675         uint16_t opcode = little_endian_read_16(packet,4);
1676         if (opcode == hci_stack->last_cmd_opcode){
1677             if (status){
1678                 command_completed = true;
1679                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1680             } else {
1681                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1682             }
1683         } else {
1684             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1685         }
1686     }
1687 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1688     // Vendor == CSR
1689     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1690         // TODO: track actual command
1691         command_completed = true;
1692     }
1693 
1694     // Vendor == Toshiba
1695     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1696         // TODO: track actual command
1697         command_completed = true;
1698         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1699         hci_stack->num_cmd_packets = 1;
1700     }
1701 #endif
1702 
1703     return command_completed;
1704 }
1705 
1706 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1707 
1708     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1709 
1710     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1711 
1712 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1713 
1714     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1715     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1716     //
1717     // HCI Reset
1718     // Timeout 100 ms
1719     // HCI Reset
1720     // Command Complete Reset
1721     // HCI Read Local Version Information
1722     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1723     // hang...
1724     //
1725     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1726     if (!command_completed
1727             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1728             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1729 
1730         uint16_t opcode = little_endian_read_16(packet,3);
1731         if (opcode == hci_reset.opcode){
1732             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1733             return;
1734         }
1735     }
1736 
1737     // CSR & H5
1738     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1739     if (!command_completed
1740             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1741             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1742 
1743         uint16_t opcode = little_endian_read_16(packet,3);
1744         if (opcode == hci_reset.opcode){
1745             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1746             return;
1747         }
1748     }
1749 
1750     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1751     // fix: Correct substate and behave as command below
1752     if (command_completed){
1753         switch (hci_stack->substate){
1754             case HCI_INIT_SEND_RESET:
1755                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1756                 break;
1757             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1758                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1759                 break;
1760             default:
1761                 break;
1762         }
1763     }
1764 
1765 #endif
1766 
1767     if (!command_completed) return;
1768 
1769     bool need_baud_change = false;
1770     bool need_addr_change = false;
1771 
1772 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1773     need_baud_change = hci_stack->config
1774                         && hci_stack->chipset
1775                         && hci_stack->chipset->set_baudrate_command
1776                         && hci_stack->hci_transport->set_baudrate
1777                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1778 
1779     need_addr_change = hci_stack->custom_bd_addr_set
1780                         && hci_stack->chipset
1781                         && hci_stack->chipset->set_bd_addr_command;
1782 #endif
1783 
1784     switch(hci_stack->substate){
1785 
1786 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1787         case HCI_INIT_SEND_RESET:
1788             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1789             // fix: just correct substate and behave as command below
1790             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1791             btstack_run_loop_remove_timer(&hci_stack->timeout);
1792             break;
1793         case HCI_INIT_W4_SEND_RESET:
1794             btstack_run_loop_remove_timer(&hci_stack->timeout);
1795             break;
1796         case HCI_INIT_W4_SEND_READ_LOCAL_NAME:
1797             log_info("Received local name, need baud change %d", (int) need_baud_change);
1798             if (need_baud_change){
1799                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1800                 return;
1801             }
1802             // skip baud change
1803             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1804             return;
1805         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1806             // for STLC2500D, baud rate change already happened.
1807             // for others, baud rate gets changed now
1808             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1809                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1810                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1811                 hci_stack->hci_transport->set_baudrate(baud_rate);
1812             }
1813             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1814             return;
1815         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1816             btstack_run_loop_remove_timer(&hci_stack->timeout);
1817             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1818             return;
1819         case HCI_INIT_W4_CUSTOM_INIT:
1820             // repeat custom init
1821             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1822             return;
1823 #else
1824         case HCI_INIT_W4_SEND_RESET:
1825             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1826             return ;
1827 #endif
1828 
1829         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1830             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1831               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1832                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1833                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1834                 return;
1835             }
1836             if (need_addr_change){
1837                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1838                 return;
1839             }
1840             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1841             return;
1842 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1843         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1844             if (need_baud_change){
1845                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1846                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
1847                 hci_stack->hci_transport->set_baudrate(baud_rate);
1848             }
1849             if (need_addr_change){
1850                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1851                 return;
1852             }
1853             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1854             return;
1855         case HCI_INIT_W4_SET_BD_ADDR:
1856             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1857             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1858             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1859                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1860                 return;
1861             }
1862             // skipping st warm boot
1863             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1864             return;
1865         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1866             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1867             return;
1868 #endif
1869         case HCI_INIT_W4_READ_BD_ADDR:
1870             // only read buffer size if supported
1871             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1872                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1873                 return;
1874             }
1875             // skipping read buffer size
1876             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1877             return;
1878         case HCI_INIT_W4_SET_EVENT_MASK:
1879             // skip Classic init commands for LE only chipsets
1880             if (!hci_classic_supported()){
1881 #ifdef ENABLE_BLE
1882                 if (hci_le_supported()){
1883                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1884                     return;
1885                 }
1886 #endif
1887                 log_error("Neither BR/EDR nor LE supported");
1888                 hci_init_done();
1889                 return;
1890             }
1891             if (!gap_ssp_supported()){
1892                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1893                 return;
1894             }
1895             break;
1896 #ifdef ENABLE_BLE
1897         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1898             // skip write le host if not supported (e.g. on LE only EM9301)
1899             if (hci_stack->local_supported_commands[0u] & 0x02u) break;
1900             hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1901             return;
1902 
1903 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1904         case HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED:
1905             log_info("Supported commands %x", hci_stack->local_supported_commands[0] & 0x30);
1906             if ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u){
1907                 hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1908                 return;
1909             }
1910             // explicit fall through to reduce repetitions
1911 
1912 #ifdef ENABLE_LE_CENTRAL
1913             hci_stack->substate = HCI_INIT_READ_WHITE_LIST_SIZE;
1914 #else
1915             hci_init_done();
1916 #endif
1917             return;
1918 #endif  /* ENABLE_LE_DATA_LENGTH_EXTENSION */
1919 
1920 #endif  /* ENABLE_BLE */
1921 
1922         case HCI_INIT_W4_WRITE_INQUIRY_MODE:
1923             // skip write secure connections host support if not supported or disabled
1924             if (!hci_stack->secure_connections_enable || (hci_stack->local_supported_commands[1u] & 0x02u) == 0u) {
1925                 hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;
1926                 return;
1927             }
1928             break;
1929 
1930 #ifdef ENABLE_SCO_OVER_HCI
1931         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1932             // skip write synchronous flow control if not supported
1933             if (hci_stack->local_supported_commands[0] & 0x04) break;
1934             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1935 
1936             /* fall through */
1937 
1938         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1939             // skip write default erroneous data reporting if not supported
1940             if (hci_stack->local_supported_commands[0] & 0x08) break;
1941             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1942 
1943             /* fall through */
1944 
1945         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1946             // skip bcm set sco pcm config on non-Broadcom chipsets
1947             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) break;
1948             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1949 
1950             /* fall through */
1951 
1952         case HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT:
1953             if (!hci_le_supported()){
1954                 // SKIP LE init for Classic only configuration
1955                 hci_init_done();
1956                 return;
1957             }
1958             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1959             break;
1960 
1961 #else /* !ENABLE_SCO_OVER_HCI */
1962 
1963         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1964 #ifdef ENABLE_SCO_OVER_PCM
1965             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) {
1966                 hci_stack->substate = HCI_INIT_BCM_WRITE_SCO_PCM_INT;
1967                 return;
1968             }
1969 #endif
1970             /* fall through */
1971 
1972         case HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
1973 #ifdef ENABLE_BLE
1974             if (hci_le_supported()){
1975                 hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE;
1976                 return;
1977             }
1978 #endif
1979             // SKIP LE init for Classic only configuration
1980             hci_init_done();
1981             return;
1982 #endif /* ENABLE_SCO_OVER_HCI */
1983 
1984 // avoid compile error due to duplicate cases: HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT == HCI_INIT_DONE-1
1985 #if defined(ENABLE_BLE) || defined(ENABLE_LE_DATA_LENGTH_EXTENSION) || defined(ENABLE_LE_CENTRAL)
1986         // Response to command before init done state -> init done
1987         case (HCI_INIT_DONE-1):
1988             hci_init_done();
1989             return;
1990 #endif
1991 
1992         default:
1993             break;
1994     }
1995     hci_initializing_next_state();
1996 }
1997 
1998 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
1999     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
2000     bd_addr_t bd_address;
2001     (void)memcpy(&bd_address, conn->address, 6);
2002 
2003 #ifdef ENABLE_CLASSIC
2004     // cache needed data
2005     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
2006 #endif
2007 
2008     // connection failed, remove entry
2009     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2010     btstack_memory_hci_connection_free( conn );
2011 
2012 #ifdef ENABLE_CLASSIC
2013     // notify client if dedicated bonding
2014     if (notify_dedicated_bonding_failed){
2015         log_info("hci notify_dedicated_bonding_failed");
2016         hci_emit_dedicated_bonding_result(bd_address, status);
2017     }
2018 
2019     // if authentication error, also delete link key
2020     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
2021         gap_drop_link_key_for_bd_addr(bd_address);
2022     }
2023 #else
2024     UNUSED(status);
2025 #endif
2026 }
2027 
2028 #ifdef ENABLE_CLASSIC
2029 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
2030     // SSP Controller
2031     if (features[6] & (1 << 3)){
2032         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
2033     }
2034     // eSCO
2035     if (features[3] & (1<<7)){
2036         conn->remote_supported_features[0] |= 1;
2037     }
2038     // Extended features
2039     if (features[7] & (1<<7)){
2040         conn->remote_supported_features[0] |= 2;
2041     }
2042 }
2043 
2044 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
2045     // SSP Host
2046     if (features[0] & (1 << 0)){
2047         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
2048     }
2049     // SC Host
2050     if (features[0] & (1 << 3)){
2051         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
2052     }
2053 }
2054 
2055 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
2056     // SC Controller
2057     if (features[1] & (1 << 0)){
2058         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2059     }
2060 }
2061 
2062 static void hci_handle_remote_features_received(hci_connection_t * conn){
2063     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
2064     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
2065     if (conn->bonding_flags & BONDING_DEDICATED){
2066         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2067     }
2068 }
2069 static bool hci_remote_sc_enabled(hci_connection_t * connection){
2070     const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2071     return (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
2072 }
2073 
2074 #endif
2075 
2076 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
2077     // handle BT initialization
2078     if (hci_stack->state == HCI_STATE_INITIALIZING) {
2079         hci_initializing_event_handler(packet, size);
2080     }
2081 
2082     // help with BT sleep
2083     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
2084         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
2085         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
2086         hci_initializing_next_state();
2087     }
2088 }
2089 
2090 #ifdef ENABLE_CLASSIC
2091 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
2092     conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2093     conn->encryption_key_size = encryption_key_size;
2094 
2095     if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) != 0) {
2096         conn->requested_security_level = LEVEL_0;
2097         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
2098         return;
2099     }
2100 
2101     // Request Authentication if not already done
2102     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
2103     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2104 }
2105 #endif
2106 
2107 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
2108     UNUSED(size);
2109 
2110     uint16_t manufacturer;
2111 #ifdef ENABLE_CLASSIC
2112     hci_con_handle_t handle;
2113     hci_connection_t * conn;
2114     uint8_t status;
2115 #endif
2116     // get num cmd packets - limit to 1 to reduce complexity
2117     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2118 
2119     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
2120     switch (opcode){
2121         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
2122             if (packet[5]) break;
2123             // terminate, name 248 chars
2124             packet[6+248] = 0;
2125             log_info("local name: %s", &packet[6]);
2126             break;
2127         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2128             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2129             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2130                 uint16_t acl_len = little_endian_read_16(packet, 6);
2131                 uint16_t sco_len = packet[8];
2132 
2133                 // determine usable ACL/SCO payload size
2134                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2135                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2136 
2137                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2138                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2139 
2140                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2141                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2142                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2143             }
2144             break;
2145         case HCI_OPCODE_HCI_READ_RSSI:
2146             if (packet[5] == ERROR_CODE_SUCCESS){
2147                 uint8_t event[5];
2148                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2149                 event[1] = 3;
2150                 (void)memcpy(&event[2], &packet[6], 3);
2151                 hci_emit_event(event, sizeof(event), 1);
2152             }
2153             break;
2154 #ifdef ENABLE_BLE
2155         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2156             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2157             hci_stack->le_acl_packets_total_num = packet[8];
2158             // determine usable ACL payload size
2159             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2160                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2161             }
2162             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2163             break;
2164 #endif
2165 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2166         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2167             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2168             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2169             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);
2170             break;
2171 #endif
2172 #ifdef ENABLE_LE_CENTRAL
2173         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2174             hci_stack->le_whitelist_capacity = packet[6];
2175             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2176             break;
2177 #endif
2178         case HCI_OPCODE_HCI_READ_BD_ADDR:
2179             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2180             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));
2181 #ifdef ENABLE_CLASSIC
2182             if (hci_stack->link_key_db){
2183                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2184             }
2185 #endif
2186             break;
2187 #ifdef ENABLE_CLASSIC
2188         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2189             hci_emit_discoverable_enabled(hci_stack->discoverable);
2190             break;
2191         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2192             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2193                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2194                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2195                 hci_emit_event(event, sizeof(event), 1);
2196             }
2197             break;
2198 #endif
2199         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2200             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2201 
2202 #ifdef ENABLE_CLASSIC
2203             // determine usable ACL packet types based on host buffer size and supported features
2204             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2205             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2206 #endif
2207             // Classic/LE
2208             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2209             break;
2210         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2211             manufacturer = little_endian_read_16(packet, 10);
2212             // map Cypress to Broadcom
2213             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2214                 log_info("Treat Cypress as Broadcom");
2215                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2216                 little_endian_store_16(packet, 10, manufacturer);
2217             }
2218             hci_stack->manufacturer = manufacturer;
2219             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2220             break;
2221         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2222             hci_stack->local_supported_commands[0] =
2223                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit  0 = Octet 14, bit 7 / Read Buffer Size
2224                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit  1 = Octet 24, bit 6 / Write Le Host Supported
2225                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit  2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2226                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     )  |  // bit  3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2227                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit  4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2228                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit  5 = Octet 35, bit 3 / LE Read Maximum Data Length
2229                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit  6 = Octet 35, bit 5 / LE Set Default PHY
2230                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit  7 = Octet 20, bit 4 / Read Encryption Key Size
2231             hci_stack->local_supported_commands[1] =
2232                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit  8 = Octet  2, bit 6 / Read Remote Extended Features
2233                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u) |  // bit  9 = Octet 32, bit 3 / Write Secure Connections Host
2234                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x02u) << 1u) |  // bit 10 = Octet 35, bit 1 / LE Set Address Resolution Enable
2235                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x02u) << 2u) |  // bit 11 = Octet 32, bit 1 / Remote OOB Extended Data Request Reply
2236                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x40u) >> 2u);   // bit 12 = Octet 32, bit 6 / Read Local OOB Extended Data command
2237             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2238             break;
2239 #ifdef ENABLE_CLASSIC
2240         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2241             if (packet[5]) return;
2242             hci_stack->synchronous_flow_control_enabled = 1;
2243             break;
2244         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2245             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2246             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2247             conn   = hci_connection_for_handle(handle);
2248             if (conn != NULL) {
2249                 uint8_t key_size = 0;
2250                 if (status == 0){
2251                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2252                     log_info("Handle %04x key Size: %u", handle, key_size);
2253                 } else {
2254                     key_size = 1;
2255                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2256                 }
2257                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2258             }
2259             break;
2260         // assert pairing complete event is emitted.
2261         // note: for SSP, Simple Pairing Complete Event is sufficient, but we want to be more robust
2262         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
2263         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
2264         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
2265             // lookup connection by gap pairing addr
2266             conn = hci_connection_for_bd_addr_and_type(hci_stack->gap_pairing_addr, BD_ADDR_TYPE_ACL);
2267             if (conn == NULL) break;
2268             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2269             break;
2270 
2271 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2272         case HCI_OPCODE_HCI_READ_LOCAL_OOB_DATA:
2273         case HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA:{
2274             uint8_t event[67];
2275             event[0] = GAP_EVENT_LOCAL_OOB_DATA;
2276             event[1] = 65;
2277             (void)memset(&event[2], 0, 65);
2278             if (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE] == ERROR_CODE_SUCCESS){
2279                 (void)memcpy(&event[3], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 32);
2280                 if (opcode == HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA){
2281                     event[2] = 3;
2282                     (void)memcpy(&event[35], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+33], 32);
2283                 } else {
2284                     event[2] = 1;
2285                 }
2286             }
2287             hci_emit_event(event, sizeof(event), 0);
2288             break;
2289         }
2290 
2291         // note: only needed if user does not provide OOB data
2292         case HCI_OPCODE_HCI_REMOTE_OOB_DATA_REQUEST_NEGATIVE_REPLY:
2293             conn = hci_connection_for_handle(hci_stack->classic_oob_con_handle);
2294             hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
2295             if (conn == NULL) break;
2296             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2297             break;
2298 #endif
2299 #endif
2300         default:
2301             break;
2302     }
2303 }
2304 
2305 #ifdef ENABLE_BLE
2306 static void event_handle_le_connection_complete(const uint8_t * packet){
2307 	bd_addr_t addr;
2308 	bd_addr_type_t addr_type;
2309 	hci_connection_t * conn;
2310 
2311 	// Connection management
2312 	reverse_bd_addr(&packet[8], addr);
2313 	addr_type = (bd_addr_type_t)packet[7];
2314 	log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2315 	conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2316 
2317 #ifdef ENABLE_LE_CENTRAL
2318 	// handle error: error is reported only to the initiator -> outgoing connection
2319 	if (packet[3]){
2320 
2321 		// handle cancelled outgoing connection
2322 		// "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2323 		//  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2324 		//  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2325 		if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2326 		    // reset state
2327             hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2328             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2329 			// get outgoing connection conn struct for direct connect
2330 			conn = gap_get_outgoing_connection();
2331 		}
2332 
2333 		// outgoing le connection establishment is done
2334 		if (conn){
2335 			// remove entry
2336 			btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2337 			btstack_memory_hci_connection_free( conn );
2338 		}
2339 		return;
2340 	}
2341 #endif
2342 
2343 	// on success, both hosts receive connection complete event
2344 	if (packet[6] == HCI_ROLE_MASTER){
2345 #ifdef ENABLE_LE_CENTRAL
2346 		// if we're master on an le connection, it was an outgoing connection and we're done with it
2347 		// note: no hci_connection_t object exists yet for connect with whitelist
2348 		if (hci_is_le_connection_type(addr_type)){
2349 			hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2350 			hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2351 		}
2352 #endif
2353 	} else {
2354 #ifdef ENABLE_LE_PERIPHERAL
2355 		// if we're slave, it was an incoming connection, advertisements have stopped
2356 		hci_stack->le_advertisements_active = false;
2357 #endif
2358 	}
2359 
2360 	// LE connections are auto-accepted, so just create a connection if there isn't one already
2361 	if (!conn){
2362 		conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2363 	}
2364 
2365 	// no memory, sorry.
2366 	if (!conn){
2367 		return;
2368 	}
2369 
2370 	conn->state = OPEN;
2371 	conn->role  = packet[6];
2372 	conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2373 	conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2374 
2375 #ifdef ENABLE_LE_PERIPHERAL
2376 	if (packet[6] == HCI_ROLE_SLAVE){
2377 		hci_update_advertisements_enabled_for_current_roles();
2378 	}
2379 #endif
2380 
2381     // init unenhanced att bearer mtu
2382     conn->att_connection.mtu = ATT_DEFAULT_MTU;
2383     conn->att_connection.mtu_exchanged = false;
2384 
2385     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2386 
2387 	// restart timer
2388 	// btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2389 	// btstack_run_loop_add_timer(&conn->timeout);
2390 
2391 	log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2392 
2393 	hci_emit_nr_connections_changed();
2394 }
2395 #endif
2396 
2397 #ifdef ENABLE_CLASSIC
2398 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){
2399     if (io_cap_local == SSP_IO_CAPABILITY_UNKNOWN) return false;
2400     // LEVEL_4 is tested by l2cap
2401     // LEVEL 3 requires MITM protection -> check io capabilities if Authenticated is possible
2402     // @see: Core Spec v5.3, Vol 3, Part C, Table 5.7
2403     if (level >= LEVEL_3){
2404         // MITM not possible without keyboard or display
2405         if (io_cap_remote >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2406         if (io_cap_local  >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2407 
2408         // MITM possible if one side has keyboard and the other has keyboard or display
2409         if (io_cap_remote == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2410         if (io_cap_local  == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2411 
2412         // MITM not possible if one side has only display and other side has no keyboard
2413         if (io_cap_remote == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2414         if (io_cap_local  == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2415     }
2416     // LEVEL 2 requires SSP, which is a given
2417     return true;
2418 }
2419 
2420 static bool btstack_is_null(uint8_t * data, uint16_t size){
2421     uint16_t i;
2422     for (i=0; i < size ; i++){
2423         if (data[i] != 0) {
2424             return false;
2425         }
2426     }
2427     return true;
2428 }
2429 
2430 static void hci_ssp_assess_security_on_io_cap_request(hci_connection_t * conn){
2431     // assess security: LEVEL 4 requires SC
2432     if ((hci_stack->gap_secure_connections_only_mode || (conn->requested_security_level == LEVEL_4)) && !hci_remote_sc_enabled(conn)){
2433         log_info("Level 4 required, but SC not supported -> abort");
2434         hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2435         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2436         return;
2437     }
2438 
2439     // assess security based on io capabilities
2440     if (conn->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
2441         // get requested security level
2442         gap_security_level_t requested_security_level = conn->requested_security_level;
2443         if (hci_stack->gap_secure_connections_only_mode){
2444             requested_security_level = LEVEL_4;
2445         }
2446 
2447         // responder: fully validate io caps of both sides as well as OOB data
2448         bool security_possible = false;
2449         security_possible = hci_ssp_security_level_possible_for_io_cap(requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io);
2450 
2451 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2452         // We assume that both Controller can reach LEVEL 4, if one side has received P-192 and the other has received P-256,
2453         // so we merge the OOB data availability
2454         uint8_t have_oob_data = conn->io_cap_response_oob_data;
2455         if (conn->classic_oob_c_192 != NULL){
2456             have_oob_data |= 1;
2457         }
2458         if (conn->classic_oob_c_256 != NULL){
2459             have_oob_data |= 2;
2460         }
2461         // for up to Level 3, either P-192 as well as P-256 will do
2462         // 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
2463         // if remote does not SC, we should not receive P-256 data either
2464         if ((requested_security_level <= LEVEL_3) && (have_oob_data != 0)){
2465             security_possible = true;
2466         }
2467         // for Level 4, P-256 is needed
2468         if ((requested_security_level == LEVEL_4 && ((have_oob_data & 2) != 0))){
2469             security_possible = true;
2470         }
2471 #endif
2472 
2473         if (security_possible == false){
2474             log_info("IOCap/OOB insufficient for level %u -> abort", conn->requested_security_level);
2475             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2476             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2477             return;
2478         }
2479     } else {
2480         // initiator: remote io cap not yet, only check if we have ability for MITM protection if requested and OOB is not supported
2481 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2482         if ((conn->requested_security_level >= LEVEL_3) && (hci_stack->ssp_io_capability >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT)){
2483             log_info("Level 3+ required, but no input/output -> abort");
2484             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2485             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2486             return;
2487         }
2488 #endif
2489     }
2490 
2491 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2492     if (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN){
2493         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
2494     } else {
2495         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2496     }
2497 #endif
2498 }
2499 
2500 #endif
2501 
2502 static void event_handler(uint8_t *packet, uint16_t size){
2503 
2504     uint16_t event_length = packet[1];
2505 
2506     // assert packet is complete
2507     if (size != (event_length + 2u)){
2508         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2509         return;
2510     }
2511 
2512     bd_addr_type_t addr_type;
2513     hci_con_handle_t handle;
2514     hci_connection_t * conn;
2515     int i;
2516     int create_connection_cmd;
2517 
2518 #ifdef ENABLE_CLASSIC
2519     hci_link_type_t link_type;
2520     bd_addr_t addr;
2521 #endif
2522 
2523     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2524 
2525     switch (hci_event_packet_get_type(packet)) {
2526 
2527         case HCI_EVENT_COMMAND_COMPLETE:
2528             handle_command_complete_event(packet, size);
2529             break;
2530 
2531         case HCI_EVENT_COMMAND_STATUS:
2532             // get num cmd packets - limit to 1 to reduce complexity
2533             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2534 
2535             // check command status to detected failed outgoing connections
2536             create_connection_cmd = 0;
2537 #ifdef ENABLE_CLASSIC
2538             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2539                 create_connection_cmd = 1;
2540             }
2541 #endif
2542 #ifdef ENABLE_LE_CENTRAL
2543             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2544                 create_connection_cmd = 1;
2545             }
2546 #endif
2547             if (create_connection_cmd) {
2548                 uint8_t status = hci_event_command_status_get_status(packet);
2549                 addr_type = hci_stack->outgoing_addr_type;
2550                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, addr_type);
2551                 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);
2552 
2553                 // reset outgoing address info
2554                 memset(hci_stack->outgoing_addr, 0, 6);
2555                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2556 
2557                 // on error
2558                 if (status != ERROR_CODE_SUCCESS){
2559 #ifdef ENABLE_LE_CENTRAL
2560                     if (hci_is_le_connection_type(addr_type)){
2561                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2562                         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2563                     }
2564 #endif
2565                     // error => outgoing connection failed
2566                     if (conn != NULL){
2567                         hci_handle_connection_failed(conn, status);
2568                     }
2569                 }
2570             }
2571 
2572 #ifdef ENABLE_CLASSIC
2573             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_inquiry)) {
2574                 uint8_t status = hci_event_command_status_get_status(packet);
2575                 log_info("command status (inquiry), status %x", status);
2576                 if (status == ERROR_CODE_SUCCESS) {
2577                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
2578                 } else {
2579                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2580                 }
2581             }
2582 #endif
2583             break;
2584 
2585         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2586             if (size < 3) return;
2587             uint16_t num_handles = packet[2];
2588             if (size != (3u + num_handles * 4u)) return;
2589             uint16_t offset = 3;
2590             for (i=0; i<num_handles;i++){
2591                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2592                 offset += 2u;
2593                 uint16_t num_packets = little_endian_read_16(packet, offset);
2594                 offset += 2u;
2595 
2596                 conn = hci_connection_for_handle(handle);
2597                 if (!conn){
2598                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2599                     continue;
2600                 }
2601 
2602                 if (conn->num_packets_sent >= num_packets){
2603                     conn->num_packets_sent -= num_packets;
2604                 } else {
2605                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2606                     conn->num_packets_sent = 0;
2607                 }
2608                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2609 
2610 #ifdef ENABLE_CLASSIC
2611                 // For SCO, we do the can_send_now_check here
2612                 hci_notify_if_sco_can_send_now();
2613 #endif
2614             }
2615             break;
2616         }
2617 
2618 #ifdef ENABLE_CLASSIC
2619         case HCI_EVENT_INQUIRY_COMPLETE:
2620             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2621                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2622                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2623                 hci_emit_event(event, sizeof(event), 1);
2624             }
2625             break;
2626         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2627             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2628                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2629             }
2630             break;
2631         case HCI_EVENT_CONNECTION_REQUEST:
2632             reverse_bd_addr(&packet[2], addr);
2633             link_type = (hci_link_type_t) packet[11];
2634 
2635             // CVE-2020-26555: reject incoming connection from device with same BD ADDR
2636             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0){
2637                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2638                 bd_addr_copy(hci_stack->decline_addr, addr);
2639                 break;
2640             }
2641 
2642             if (hci_stack->gap_classic_accept_callback != NULL){
2643                 if ((*hci_stack->gap_classic_accept_callback)(addr, link_type) == 0){
2644                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2645                     bd_addr_copy(hci_stack->decline_addr, addr);
2646                     break;
2647                 }
2648             }
2649 
2650             // TODO: eval COD 8-10
2651             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), (unsigned int) link_type);
2652             addr_type = (link_type == HCI_LINK_TYPE_ACL) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2653             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2654             if (!conn) {
2655                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2656             }
2657             if (!conn) {
2658                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2659                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2660                 bd_addr_copy(hci_stack->decline_addr, addr);
2661                 break;
2662             }
2663             conn->role  = HCI_ROLE_SLAVE;
2664             conn->state = RECEIVED_CONNECTION_REQUEST;
2665             // store info about eSCO
2666             if (link_type == HCI_LINK_TYPE_ESCO){
2667                 conn->remote_supported_features[0] |= 1;
2668             }
2669             hci_run();
2670             break;
2671 
2672         case HCI_EVENT_CONNECTION_COMPLETE:
2673             // Connection management
2674             reverse_bd_addr(&packet[5], addr);
2675             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2676             addr_type = BD_ADDR_TYPE_ACL;
2677             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2678             if (conn) {
2679                 if (!packet[2]){
2680                     conn->state = OPEN;
2681                     conn->con_handle = little_endian_read_16(packet, 3);
2682 
2683                     // queue get remote feature
2684                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2685 
2686                     // queue set supervision timeout if we're master
2687                     if ((hci_stack->link_supervision_timeout != HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT) && (conn->role == HCI_ROLE_MASTER)){
2688                         connectionSetAuthenticationFlags(conn, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
2689                     }
2690 
2691                     // restart timer
2692                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2693                     btstack_run_loop_add_timer(&conn->timeout);
2694 
2695                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2696 
2697                     hci_emit_nr_connections_changed();
2698                 } else {
2699                     // connection failed
2700                     hci_handle_connection_failed(conn, packet[2]);
2701                 }
2702             }
2703             break;
2704 
2705         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2706             reverse_bd_addr(&packet[5], addr);
2707             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2708             if (packet[2]){
2709                 // connection failed
2710                 break;
2711             }
2712             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2713             if (!conn) {
2714                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2715             }
2716             if (!conn) {
2717                 break;
2718             }
2719             conn->state = OPEN;
2720             conn->con_handle = little_endian_read_16(packet, 3);
2721 
2722 #ifdef ENABLE_SCO_OVER_HCI
2723             // update SCO
2724             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2725                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2726             }
2727             // trigger can send now
2728             if (hci_have_usb_transport()){
2729                 hci_stack->sco_can_send_now = true;
2730             }
2731 #endif
2732 #ifdef HAVE_SCO_TRANSPORT
2733             // configure sco transport
2734             if (hci_stack->sco_transport != NULL){
2735                 sco_format_t sco_format = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? SCO_FORMAT_8_BIT : SCO_FORMAT_16_BIT;
2736                 hci_stack->sco_transport->open(conn->con_handle, sco_format);
2737             }
2738 #endif
2739             break;
2740 
2741         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2742             handle = little_endian_read_16(packet, 3);
2743             conn = hci_connection_for_handle(handle);
2744             if (!conn) break;
2745             if (!packet[2]){
2746                 const uint8_t * features = &packet[5];
2747                 hci_handle_remote_features_page_0(conn, features);
2748 
2749                 // read extended features if possible
2750                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2751                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2752                     break;
2753                 }
2754             }
2755             hci_handle_remote_features_received(conn);
2756             break;
2757 
2758         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2759             handle = little_endian_read_16(packet, 3);
2760             conn = hci_connection_for_handle(handle);
2761             if (!conn) break;
2762             // status = ok, page = 1
2763             if (!packet[2]) {
2764                 uint8_t page_number = packet[5];
2765                 uint8_t maximum_page_number = packet[6];
2766                 const uint8_t * features = &packet[7];
2767                 bool done = false;
2768                 switch (page_number){
2769                     case 1:
2770                         hci_handle_remote_features_page_1(conn, features);
2771                         if (maximum_page_number >= 2){
2772                             // get Secure Connections (Controller) from Page 2 if available
2773                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2774                         } else {
2775                             // otherwise, assume SC (Controller) == SC (Host)
2776                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2777                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2778                             }
2779                             done = true;
2780                         }
2781                         break;
2782                     case 2:
2783                         hci_handle_remote_features_page_2(conn, features);
2784                         done = true;
2785                         break;
2786                     default:
2787                         break;
2788                 }
2789                 if (!done) break;
2790             }
2791             hci_handle_remote_features_received(conn);
2792             break;
2793 
2794         case HCI_EVENT_LINK_KEY_REQUEST:
2795             // request handled by hci_run()
2796             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
2797             break;
2798 
2799         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2800             hci_event_link_key_request_get_bd_addr(packet, addr);
2801             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2802             if (!conn) break;
2803 
2804             hci_pairing_complete(conn, ERROR_CODE_SUCCESS);
2805 
2806             // CVE-2020-26555: ignore NULL link key
2807             // default link_key_type = INVALID_LINK_KEY asserts that NULL key won't be used for encryption
2808             if (btstack_is_null(&packet[8], 16)) break;
2809 
2810             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2811             // Change Connection Encryption keeps link key type
2812             if (link_key_type != CHANGED_COMBINATION_KEY){
2813                 conn->link_key_type = link_key_type;
2814             }
2815 
2816             // cache link key. link keys stored in little-endian format for legacy reasons
2817             memcpy(&conn->link_key, &packet[8], 16);
2818 
2819             // only store link key:
2820             // - if bondable enabled
2821             if (hci_stack->bondable == false) break;
2822             // - if security level sufficient
2823             if (gap_security_level_for_link_key_type(link_key_type) < conn->requested_security_level) break;
2824             // - for SSP, also check if remote side requested bonding as well
2825             if (conn->link_key_type != COMBINATION_KEY){
2826                 bool remote_bonding = conn->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2827                 if (!remote_bonding){
2828                     break;
2829                 }
2830             }
2831             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2832             break;
2833         }
2834 
2835         case HCI_EVENT_PIN_CODE_REQUEST:
2836             hci_event_pin_code_request_get_bd_addr(packet, addr);
2837             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2838             if (!conn) break;
2839 
2840             hci_pairing_started(conn, false);
2841             // abort pairing if: non-bondable mode (pin code request is not forwarded to app)
2842             if (!hci_stack->bondable ){
2843                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2844                 hci_pairing_complete(conn, ERROR_CODE_PAIRING_NOT_ALLOWED);
2845                 hci_run();
2846                 return;
2847             }
2848             // abort pairing if: LEVEL_4 required (pin code request is not forwarded to app)
2849             if ((hci_stack->gap_secure_connections_only_mode) || (conn->requested_security_level == LEVEL_4)){
2850                 log_info("Level 4 required, but SC not supported -> abort");
2851                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2852                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2853                 hci_run();
2854                 return;
2855             }
2856             break;
2857 
2858         case HCI_EVENT_IO_CAPABILITY_RESPONSE:
2859             hci_event_io_capability_response_get_bd_addr(packet, addr);
2860             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2861             if (!conn) break;
2862 
2863             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE);
2864             hci_pairing_started(conn, true);
2865             conn->io_cap_response_auth_req = hci_event_io_capability_response_get_authentication_requirements(packet);
2866             conn->io_cap_response_io       = hci_event_io_capability_response_get_io_capability(packet);
2867 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2868             conn->io_cap_response_oob_data = hci_event_io_capability_response_get_oob_data_present(packet);
2869 #endif
2870             break;
2871 
2872         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2873             hci_event_io_capability_response_get_bd_addr(packet, addr);
2874             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2875             if (!conn) break;
2876 
2877             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
2878             hci_connection_timestamp(conn);
2879             hci_pairing_started(conn, true);
2880             break;
2881 
2882 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2883         case HCI_EVENT_REMOTE_OOB_DATA_REQUEST:
2884             hci_event_remote_oob_data_request_get_bd_addr(packet, addr);
2885             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2886             if (!conn) break;
2887 
2888             hci_connection_timestamp(conn);
2889 
2890             hci_pairing_started(conn, true);
2891 
2892             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
2893             break;
2894 #endif
2895 
2896         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2897             hci_event_user_confirmation_request_get_bd_addr(packet, addr);
2898             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2899             if (!conn) break;
2900             if (hci_ssp_security_level_possible_for_io_cap(conn->requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io)) {
2901                 if (hci_stack->ssp_auto_accept){
2902                     hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
2903                 };
2904             } else {
2905                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2906                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
2907                 // don't forward event to app
2908                 hci_run();
2909                 return;
2910             }
2911             break;
2912 
2913         case HCI_EVENT_USER_PASSKEY_REQUEST:
2914             // Pairing using Passkey results in MITM protection. If Level 4 is required, support for SC is validated on IO Cap Request
2915             if (hci_stack->ssp_auto_accept){
2916                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
2917             };
2918             break;
2919 
2920         case HCI_EVENT_MODE_CHANGE:
2921             handle = hci_event_mode_change_get_handle(packet);
2922             conn = hci_connection_for_handle(handle);
2923             if (!conn) break;
2924             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2925             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2926             break;
2927 #endif
2928 
2929         case HCI_EVENT_ENCRYPTION_CHANGE:
2930             handle = hci_event_encryption_change_get_connection_handle(packet);
2931             conn = hci_connection_for_handle(handle);
2932             if (!conn) break;
2933             if (hci_event_encryption_change_get_status(packet) == 0u) {
2934                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2935                 if (encryption_enabled){
2936                     if (hci_is_le_connection(conn)){
2937                         // For LE, we accept connection as encrypted
2938                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2939                     }
2940 #ifdef ENABLE_CLASSIC
2941                     else {
2942 
2943                         // dedicated bonding: send result and disconnect
2944                         if (conn->bonding_flags & BONDING_DEDICATED){
2945                             conn->bonding_flags &= ~BONDING_DEDICATED;
2946                             conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
2947                             conn->bonding_status = packet[2];
2948                             break;
2949                         }
2950 
2951                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
2952                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
2953                         bool connected_uses_aes_ccm = encryption_enabled == 2;
2954                         if (hci_stack->secure_connections_active && sc_used_during_pairing && !connected_uses_aes_ccm){
2955                             log_info("SC during pairing, but only E0 now -> abort");
2956                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2957                             break;
2958                         }
2959 
2960                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
2961                         if (connected_uses_aes_ccm){
2962                             conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
2963                         }
2964 
2965 #ifdef ENABLE_TESTING_SUPPORT
2966                         // work around for issue with PTS dongle
2967                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
2968 #endif
2969 
2970                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
2971                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
2972                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
2973                         } else {
2974                             // if not, pretend everything is perfect
2975                             hci_handle_read_encryption_key_size_complete(conn, 16);
2976                         }
2977                     }
2978 #endif
2979                 } else {
2980                     conn->authentication_flags &= ~AUTH_FLAG_CONNECTION_ENCRYPTED;
2981                 }
2982             }
2983 
2984             break;
2985 
2986 #ifdef ENABLE_CLASSIC
2987         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
2988             handle = hci_event_authentication_complete_get_connection_handle(packet);
2989             conn = hci_connection_for_handle(handle);
2990             if (!conn) break;
2991 
2992             // clear authentication active flag
2993             conn->bonding_flags &= ~BONDING_SENT_AUTHENTICATE_REQUEST;
2994             hci_pairing_complete(conn, hci_event_authentication_complete_get_status(packet));
2995 
2996             // authenticated only if auth status == 0
2997             if (hci_event_authentication_complete_get_status(packet) == 0){
2998                 // authenticated
2999                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3000 
3001                 // If not already encrypted, start encryption
3002                 if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0){
3003                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3004                     break;
3005                 }
3006             }
3007 
3008             // emit updated security level
3009             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
3010             break;
3011 
3012         case HCI_EVENT_SIMPLE_PAIRING_COMPLETE:
3013             hci_event_simple_pairing_complete_get_bd_addr(packet, addr);
3014             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3015             if (!conn) break;
3016 
3017             // treat successfully paired connection as authenticated
3018             if (hci_event_simple_pairing_complete_get_status(packet) == ERROR_CODE_SUCCESS){
3019                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3020             }
3021 
3022             hci_pairing_complete(conn, hci_event_simple_pairing_complete_get_status(packet));
3023             break;
3024 #endif
3025 
3026         // HCI_EVENT_DISCONNECTION_COMPLETE
3027         // has been split, to first notify stack before shutting connection down
3028         // see end of function, too.
3029         case HCI_EVENT_DISCONNECTION_COMPLETE:
3030             if (packet[2]) break;   // status != 0
3031             handle = little_endian_read_16(packet, 3);
3032             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
3033             if (hci_stack->acl_fragmentation_total_size > 0u) {
3034                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
3035                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
3036                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
3037                     hci_stack->acl_fragmentation_total_size = 0;
3038                     hci_stack->acl_fragmentation_pos = 0;
3039                     if (release_buffer){
3040                         hci_release_packet_buffer();
3041                     }
3042                 }
3043             }
3044 
3045             conn = hci_connection_for_handle(handle);
3046             if (!conn) break;
3047 #ifdef ENABLE_CLASSIC
3048             // pairing failed if it was ongoing
3049             hci_pairing_complete(conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3050 #endif
3051             // mark connection for shutdown
3052             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
3053 
3054             // emit dedicatd bonding event
3055             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
3056                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
3057             }
3058 
3059 #ifdef ENABLE_BLE
3060 #ifdef ENABLE_LE_PERIPHERAL
3061             // re-enable advertisements for le connections if active
3062             if (hci_is_le_connection(conn)){
3063                 hci_update_advertisements_enabled_for_current_roles();
3064             }
3065 #endif
3066 #endif
3067             break;
3068 
3069         case HCI_EVENT_HARDWARE_ERROR:
3070             log_error("Hardware Error: 0x%02x", packet[2]);
3071             if (hci_stack->hardware_error_callback){
3072                 (*hci_stack->hardware_error_callback)(packet[2]);
3073             } else {
3074                 // if no special requests, just reboot stack
3075                 hci_power_control_off();
3076                 hci_power_control_on();
3077             }
3078             break;
3079 
3080 #ifdef ENABLE_CLASSIC
3081         case HCI_EVENT_ROLE_CHANGE:
3082             if (packet[2]) break;   // status != 0
3083             reverse_bd_addr(&packet[3], addr);
3084             addr_type = BD_ADDR_TYPE_ACL;
3085             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3086             if (!conn) break;
3087             conn->role = packet[9];
3088             break;
3089 #endif
3090 
3091         case HCI_EVENT_TRANSPORT_PACKET_SENT:
3092             // release packet buffer only for asynchronous transport and if there are not further fragements
3093             if (hci_transport_synchronous()) {
3094                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
3095                 return; // instead of break: to avoid re-entering hci_run()
3096             }
3097             hci_stack->acl_fragmentation_tx_active = 0;
3098             if (hci_stack->acl_fragmentation_total_size) break;
3099             hci_release_packet_buffer();
3100 
3101             // L2CAP receives this event via the hci_emit_event below
3102 
3103 #ifdef ENABLE_CLASSIC
3104             // For SCO, we do the can_send_now_check here
3105             hci_notify_if_sco_can_send_now();
3106 #endif
3107             break;
3108 
3109 #ifdef ENABLE_CLASSIC
3110         case HCI_EVENT_SCO_CAN_SEND_NOW:
3111             // For SCO, we do the can_send_now_check here
3112             hci_stack->sco_can_send_now = true;
3113             hci_notify_if_sco_can_send_now();
3114             return;
3115 
3116         // explode inquriy results for easier consumption
3117         case HCI_EVENT_INQUIRY_RESULT:
3118         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
3119         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
3120             gap_inquiry_explode(packet, size);
3121             break;
3122 #endif
3123 
3124 #ifdef ENABLE_BLE
3125         case HCI_EVENT_LE_META:
3126             switch (packet[2]){
3127 #ifdef ENABLE_LE_CENTRAL
3128                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
3129                     // log_info("advertising report received");
3130                     if (!hci_stack->le_scanning_enabled) break;
3131                     le_handle_advertisement_report(packet, size);
3132                     break;
3133 #endif
3134                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
3135 					event_handle_le_connection_complete(packet);
3136                     break;
3137 
3138                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
3139                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
3140                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
3141                     conn = hci_connection_for_handle(handle);
3142                     if (!conn) break;
3143                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
3144                     break;
3145 
3146                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
3147                     // connection
3148                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
3149                     conn = hci_connection_for_handle(handle);
3150                     if (conn) {
3151                         // read arguments
3152                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
3153                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
3154                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
3155                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
3156 
3157                         // validate against current connection parameter range
3158                         le_connection_parameter_range_t existing_range;
3159                         gap_get_connection_parameter_range(&existing_range);
3160                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
3161                         if (update_parameter){
3162                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
3163                             conn->le_conn_interval_min = le_conn_interval_min;
3164                             conn->le_conn_interval_max = le_conn_interval_max;
3165                             conn->le_conn_latency = le_conn_latency;
3166                             conn->le_supervision_timeout = le_supervision_timeout;
3167                         } else {
3168                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NEGATIVE_REPLY;
3169                         }
3170                     }
3171                     break;
3172 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
3173                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
3174                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
3175                     conn = hci_connection_for_handle(handle);
3176                     if (conn) {
3177                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
3178                     }
3179                     break;
3180 #endif
3181                 default:
3182                     break;
3183             }
3184             break;
3185 #endif
3186         case HCI_EVENT_VENDOR_SPECIFIC:
3187             // Vendor specific commands often create vendor specific event instead of num completed packets
3188             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
3189             switch (hci_stack->manufacturer){
3190                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
3191                     hci_stack->num_cmd_packets = 1;
3192                     break;
3193                 default:
3194                     break;
3195             }
3196             break;
3197         default:
3198             break;
3199     }
3200 
3201     handle_event_for_current_stack_state(packet, size);
3202 
3203     // notify upper stack
3204 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
3205 
3206     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
3207     if ((hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE) && (packet[2] == 0)){
3208 		handle = little_endian_read_16(packet, 3);
3209 		hci_connection_t * aConn = hci_connection_for_handle(handle);
3210 		// discard connection if app did not trigger a reconnect in the event handler
3211 		if (aConn && aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
3212 			hci_shutdown_connection(aConn);
3213 		}
3214     }
3215 
3216 	// execute main loop
3217 	hci_run();
3218 }
3219 
3220 #ifdef ENABLE_CLASSIC
3221 
3222 #ifdef ENABLE_SCO_OVER_HCI
3223 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
3224 static void sco_schedule_tx(hci_connection_t * conn);
3225 
3226 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
3227     log_debug("SCO TX Timeout");
3228     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
3229     hci_connection_t * conn = hci_connection_for_handle(con_handle);
3230     if (!conn) return;
3231 
3232     // trigger send
3233     conn->sco_tx_ready = 1;
3234     // extra packet if CVSD but SCO buffer is too short
3235     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
3236         conn->sco_tx_ready++;
3237     }
3238     hci_notify_if_sco_can_send_now();
3239 }
3240 
3241 
3242 #define SCO_TX_AFTER_RX_MS (6)
3243 
3244 static void sco_schedule_tx(hci_connection_t * conn){
3245 
3246     uint32_t now = btstack_run_loop_get_time_ms();
3247     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
3248     int time_delta_ms = sco_tx_ms - now;
3249 
3250     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
3251 
3252     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
3253     btstack_run_loop_remove_timer(timer);
3254     btstack_run_loop_set_timer(timer, time_delta_ms);
3255     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
3256     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
3257     btstack_run_loop_add_timer(timer);
3258 }
3259 #endif
3260 
3261 static void sco_handler(uint8_t * packet, uint16_t size){
3262     // lookup connection struct
3263     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
3264     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
3265     if (!conn) return;
3266 
3267 #ifdef ENABLE_SCO_OVER_HCI
3268     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
3269     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
3270         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
3271             packet[2] = 0x3c;
3272             memmove(&packet[3], &packet[23], 63);
3273             size = 63;
3274         }
3275     }
3276 
3277     if (hci_have_usb_transport()){
3278         // Nothing to do
3279     } else {
3280         // 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);
3281         if (hci_stack->synchronous_flow_control_enabled == 0){
3282             uint32_t now = btstack_run_loop_get_time_ms();
3283 
3284             if (!conn->sco_rx_valid){
3285                 // ignore first 10 packets
3286                 conn->sco_rx_count++;
3287                 // log_debug("sco rx count %u", conn->sco_rx_count);
3288                 if (conn->sco_rx_count == 10) {
3289                     // use first timestamp as is and pretent it just started
3290                     conn->sco_rx_ms = now;
3291                     conn->sco_rx_valid = 1;
3292                     conn->sco_rx_count = 0;
3293                     sco_schedule_tx(conn);
3294                 }
3295             } else {
3296                 // track expected arrival timme
3297                 conn->sco_rx_count++;
3298                 conn->sco_rx_ms += 7;
3299                 int delta = (int32_t) (now - conn->sco_rx_ms);
3300                 if (delta > 0){
3301                     conn->sco_rx_ms++;
3302                 }
3303                 // log_debug("sco rx %u", conn->sco_rx_ms);
3304                 sco_schedule_tx(conn);
3305             }
3306         }
3307     }
3308 #endif
3309 
3310     // deliver to app
3311     if (hci_stack->sco_packet_handler) {
3312         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
3313     }
3314 
3315 #ifdef HAVE_SCO_TRANSPORT
3316     // We can send one packet for each received packet
3317     conn->sco_tx_ready++;
3318     hci_notify_if_sco_can_send_now();
3319 #endif
3320 
3321 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3322     conn->num_packets_completed++;
3323     hci_stack->host_completed_packets = 1;
3324     hci_run();
3325 #endif
3326 }
3327 #endif
3328 
3329 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
3330     hci_dump_packet(packet_type, 1, packet, size);
3331     switch (packet_type) {
3332         case HCI_EVENT_PACKET:
3333             event_handler(packet, size);
3334             break;
3335         case HCI_ACL_DATA_PACKET:
3336             acl_handler(packet, size);
3337             break;
3338 #ifdef ENABLE_CLASSIC
3339         case HCI_SCO_DATA_PACKET:
3340             sco_handler(packet, size);
3341             break;
3342 #endif
3343         default:
3344             break;
3345     }
3346 }
3347 
3348 /**
3349  * @brief Add event packet handler.
3350  */
3351 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
3352     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3353 }
3354 
3355 
3356 /** Register HCI packet handlers */
3357 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
3358     hci_stack->acl_packet_handler = handler;
3359 }
3360 
3361 #ifdef ENABLE_CLASSIC
3362 /**
3363  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
3364  */
3365 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
3366     hci_stack->sco_packet_handler = handler;
3367 }
3368 #endif
3369 
3370 static void hci_state_reset(void){
3371     // no connections yet
3372     hci_stack->connections = NULL;
3373 
3374     // keep discoverable/connectable as this has been requested by the client(s)
3375     // hci_stack->discoverable = 0;
3376     // hci_stack->connectable = 0;
3377     // hci_stack->bondable = 1;
3378     // hci_stack->own_addr_type = 0;
3379 
3380     // buffer is free
3381     hci_stack->hci_packet_buffer_reserved = false;
3382 
3383     // no pending cmds
3384     hci_stack->decline_reason = 0;
3385     hci_stack->new_scan_enable_value = 0xff;
3386 
3387     hci_stack->secure_connections_active = false;
3388 
3389 #ifdef ENABLE_CLASSIC
3390     hci_stack->new_page_scan_interval = 0xffff;
3391     hci_stack->new_page_scan_window = 0xffff;
3392     hci_stack->new_page_scan_type = 0xff;
3393     hci_stack->inquiry_lap = GAP_IAC_GENERAL_INQUIRY;
3394     hci_stack->gap_tasks =
3395             GAP_TASK_SET_DEFAULT_LINK_POLICY |
3396             GAP_TASK_SET_CLASS_OF_DEVICE |
3397             GAP_TASK_SET_LOCAL_NAME |
3398             GAP_TASK_SET_EIR_DATA;
3399 #endif
3400 
3401 #ifdef ENABLE_CLASSIC_PAIRING_OOB
3402     hci_stack->classic_read_local_oob_data = true;
3403     hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
3404 #endif
3405 
3406     // LE
3407 #ifdef ENABLE_BLE
3408     memset(hci_stack->le_random_address, 0, 6);
3409     hci_stack->le_random_address_set = 0;
3410 #endif
3411 #ifdef ENABLE_LE_CENTRAL
3412     hci_stack->le_scanning_active  = false;
3413     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3414     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
3415     hci_stack->le_whitelist_capacity = 0;
3416 #endif
3417 #ifdef ENABLE_LE_PERIPHERAL
3418     hci_stack->le_advertisements_active = false;
3419     if ((hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_PARAMS_SET) != 0){
3420         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3421     }
3422     if (hci_stack->le_advertisements_data != NULL){
3423         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3424     }
3425 #endif
3426 }
3427 
3428 #ifdef ENABLE_CLASSIC
3429 /**
3430  * @brief Configure Bluetooth hardware control. Has to be called before power on.
3431  */
3432 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
3433     // store and open remote device db
3434     hci_stack->link_key_db = link_key_db;
3435     if (hci_stack->link_key_db) {
3436         hci_stack->link_key_db->open();
3437     }
3438 }
3439 #endif
3440 
3441 void hci_init(const hci_transport_t *transport, const void *config){
3442 
3443 #ifdef HAVE_MALLOC
3444     if (!hci_stack) {
3445         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
3446     }
3447 #else
3448     hci_stack = &hci_stack_static;
3449 #endif
3450     memset(hci_stack, 0, sizeof(hci_stack_t));
3451 
3452     // reference to use transport layer implementation
3453     hci_stack->hci_transport = transport;
3454 
3455     // reference to used config
3456     hci_stack->config = config;
3457 
3458     // setup pointer for outgoing packet buffer
3459     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3460 
3461     // max acl payload size defined in config.h
3462     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3463 
3464     // register packet handlers with transport
3465     transport->register_packet_handler(&packet_handler);
3466 
3467     hci_stack->state = HCI_STATE_OFF;
3468 
3469     // class of device
3470     hci_stack->class_of_device = 0x007a020c; // Smartphone
3471 
3472     // bondable by default
3473     hci_stack->bondable = 1;
3474 
3475 #ifdef ENABLE_CLASSIC
3476     // classic name
3477     hci_stack->local_name = default_classic_name;
3478 
3479     // Master slave policy
3480     hci_stack->master_slave_policy = 1;
3481 
3482     // Allow Role Switch
3483     hci_stack->allow_role_switch = 1;
3484 
3485     // Default / minimum security level = 2
3486     hci_stack->gap_security_level = LEVEL_2;
3487 
3488     // Default Security Mode 4
3489     hci_stack->gap_security_mode = GAP_SECURITY_MODE_4;
3490 
3491     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3492     hci_stack->gap_required_encyrption_key_size = 7;
3493 
3494     // Link Supervision Timeout
3495     hci_stack->link_supervision_timeout = HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT;
3496 
3497 #endif
3498 
3499     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3500     hci_stack->ssp_enable = 1;
3501     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3502     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3503     hci_stack->ssp_auto_accept = 1;
3504 
3505     // Secure Connections: enable (requires support from Controller)
3506     hci_stack->secure_connections_enable = true;
3507 
3508     // voice setting - signed 16 bit pcm data with CVSD over the air
3509     hci_stack->sco_voice_setting = 0x60;
3510 
3511 #ifdef ENABLE_LE_CENTRAL
3512     // connection parameter to use for outgoing connections
3513     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3514     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3515     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3516     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3517     hci_stack->le_connection_latency      = 4;         // 4
3518     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3519     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3520     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3521 
3522     // default LE Scanning
3523     hci_stack->le_scan_type     =   0x1; // active
3524     hci_stack->le_scan_interval = 0x1e0; // 300 ms
3525     hci_stack->le_scan_window   =  0x30; //  30 ms
3526 #endif
3527 
3528 #ifdef ENABLE_LE_PERIPHERAL
3529     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3530 #endif
3531 
3532     // connection parameter range used to answer connection parameter update requests in l2cap
3533     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3534     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3535     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3536     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3537     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3538     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3539 
3540     hci_state_reset();
3541 }
3542 
3543 void hci_deinit(void){
3544 #ifdef HAVE_MALLOC
3545     if (hci_stack) {
3546         free(hci_stack);
3547     }
3548 #endif
3549     hci_stack = NULL;
3550 
3551 #ifdef ENABLE_CLASSIC
3552     disable_l2cap_timeouts = 0;
3553 #endif
3554 }
3555 
3556 /**
3557  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3558  */
3559 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3560     hci_stack->chipset = chipset_driver;
3561 
3562     // reset chipset driver - init is also called on power_up
3563     if (hci_stack->chipset && hci_stack->chipset->init){
3564         hci_stack->chipset->init(hci_stack->config);
3565     }
3566 }
3567 
3568 /**
3569  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3570  */
3571 void hci_set_control(const btstack_control_t *hardware_control){
3572     // references to used control implementation
3573     hci_stack->control = hardware_control;
3574     // init with transport config
3575     hardware_control->init(hci_stack->config);
3576 }
3577 
3578 void hci_close(void){
3579 
3580 #ifdef ENABLE_CLASSIC
3581     // close remote device db
3582     if (hci_stack->link_key_db) {
3583         hci_stack->link_key_db->close();
3584     }
3585 #endif
3586 
3587     btstack_linked_list_iterator_t lit;
3588     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3589     while (btstack_linked_list_iterator_has_next(&lit)){
3590         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3591         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3592         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3593         hci_shutdown_connection(connection);
3594     }
3595 
3596     hci_power_control(HCI_POWER_OFF);
3597 
3598 #ifdef HAVE_MALLOC
3599     free(hci_stack);
3600 #endif
3601     hci_stack = NULL;
3602 }
3603 
3604 #ifdef HAVE_SCO_TRANSPORT
3605 void hci_set_sco_transport(const btstack_sco_transport_t *sco_transport){
3606     hci_stack->sco_transport = sco_transport;
3607     sco_transport->register_packet_handler(&packet_handler);
3608 }
3609 #endif
3610 
3611 #ifdef ENABLE_CLASSIC
3612 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3613     // validate ranage and set
3614     if (encryption_key_size < 7)  return;
3615     if (encryption_key_size > 16) return;
3616     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3617 }
3618 
3619 uint8_t gap_set_security_mode(gap_security_mode_t security_mode){
3620     if ((security_mode == GAP_SECURITY_MODE_4) || (security_mode == GAP_SECURITY_MODE_2)){
3621         hci_stack->gap_security_mode = security_mode;
3622         return ERROR_CODE_SUCCESS;
3623     } else {
3624         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3625     }
3626 }
3627 
3628 gap_security_mode_t gap_get_security_mode(void){
3629     return hci_stack->gap_security_mode;
3630 }
3631 
3632 void gap_set_security_level(gap_security_level_t security_level){
3633     hci_stack->gap_security_level = security_level;
3634 }
3635 
3636 gap_security_level_t gap_get_security_level(void){
3637     if (hci_stack->gap_secure_connections_only_mode){
3638         return LEVEL_4;
3639     }
3640     return hci_stack->gap_security_level;
3641 }
3642 
3643 void gap_set_minimal_service_security_level(gap_security_level_t security_level){
3644     hci_stack->gap_minimal_service_security_level = security_level;
3645 }
3646 
3647 void gap_set_secure_connections_only_mode(bool enable){
3648     hci_stack->gap_secure_connections_only_mode = enable;
3649 }
3650 
3651 bool gap_get_secure_connections_only_mode(void){
3652     return hci_stack->gap_secure_connections_only_mode;
3653 }
3654 #endif
3655 
3656 #ifdef ENABLE_CLASSIC
3657 void gap_set_class_of_device(uint32_t class_of_device){
3658     hci_stack->class_of_device = class_of_device;
3659     hci_stack->gap_tasks |= GAP_TASK_SET_CLASS_OF_DEVICE;
3660     hci_run();
3661 }
3662 
3663 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3664     hci_stack->default_link_policy_settings = default_link_policy_settings;
3665     hci_stack->gap_tasks |= GAP_TASK_SET_DEFAULT_LINK_POLICY;
3666     hci_run();
3667 }
3668 
3669 void gap_set_allow_role_switch(bool allow_role_switch){
3670     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3671 }
3672 
3673 uint8_t hci_get_allow_role_switch(void){
3674     return  hci_stack->allow_role_switch;
3675 }
3676 
3677 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3678     hci_stack->link_supervision_timeout = link_supervision_timeout;
3679 }
3680 
3681 void hci_disable_l2cap_timeout_check(void){
3682     disable_l2cap_timeouts = 1;
3683 }
3684 #endif
3685 
3686 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
3687 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3688 void hci_set_bd_addr(bd_addr_t addr){
3689     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3690     hci_stack->custom_bd_addr_set = 1;
3691 }
3692 #endif
3693 
3694 // State-Module-Driver overview
3695 // state                    module  low-level
3696 // HCI_STATE_OFF             off      close
3697 // HCI_STATE_INITIALIZING,   on       open
3698 // HCI_STATE_WORKING,        on       open
3699 // HCI_STATE_HALTING,        on       open
3700 // HCI_STATE_SLEEPING,    off/sleep   close
3701 // HCI_STATE_FALLING_ASLEEP  on       open
3702 
3703 static int hci_power_control_on(void){
3704 
3705     // power on
3706     int err = 0;
3707     if (hci_stack->control && hci_stack->control->on){
3708         err = (*hci_stack->control->on)();
3709     }
3710     if (err){
3711         log_error( "POWER_ON failed");
3712         hci_emit_hci_open_failed();
3713         return err;
3714     }
3715 
3716     // int chipset driver
3717     if (hci_stack->chipset && hci_stack->chipset->init){
3718         hci_stack->chipset->init(hci_stack->config);
3719     }
3720 
3721     // init transport
3722     if (hci_stack->hci_transport->init){
3723         hci_stack->hci_transport->init(hci_stack->config);
3724     }
3725 
3726     // open transport
3727     err = hci_stack->hci_transport->open();
3728     if (err){
3729         log_error( "HCI_INIT failed, turning Bluetooth off again");
3730         if (hci_stack->control && hci_stack->control->off){
3731             (*hci_stack->control->off)();
3732         }
3733         hci_emit_hci_open_failed();
3734         return err;
3735     }
3736     return 0;
3737 }
3738 
3739 static void hci_power_control_off(void){
3740 
3741     log_info("hci_power_control_off");
3742 
3743     // close low-level device
3744     hci_stack->hci_transport->close();
3745 
3746     log_info("hci_power_control_off - hci_transport closed");
3747 
3748     // power off
3749     if (hci_stack->control && hci_stack->control->off){
3750         (*hci_stack->control->off)();
3751     }
3752 
3753     log_info("hci_power_control_off - control closed");
3754 
3755     hci_stack->state = HCI_STATE_OFF;
3756 }
3757 
3758 static void hci_power_control_sleep(void){
3759 
3760     log_info("hci_power_control_sleep");
3761 
3762 #if 0
3763     // don't close serial port during sleep
3764 
3765     // close low-level device
3766     hci_stack->hci_transport->close(hci_stack->config);
3767 #endif
3768 
3769     // sleep mode
3770     if (hci_stack->control && hci_stack->control->sleep){
3771         (*hci_stack->control->sleep)();
3772     }
3773 
3774     hci_stack->state = HCI_STATE_SLEEPING;
3775 }
3776 
3777 static int hci_power_control_wake(void){
3778 
3779     log_info("hci_power_control_wake");
3780 
3781     // wake on
3782     if (hci_stack->control && hci_stack->control->wake){
3783         (*hci_stack->control->wake)();
3784     }
3785 
3786 #if 0
3787     // open low-level device
3788     int err = hci_stack->hci_transport->open(hci_stack->config);
3789     if (err){
3790         log_error( "HCI_INIT failed, turning Bluetooth off again");
3791         if (hci_stack->control && hci_stack->control->off){
3792             (*hci_stack->control->off)();
3793         }
3794         hci_emit_hci_open_failed();
3795         return err;
3796     }
3797 #endif
3798 
3799     return 0;
3800 }
3801 
3802 static void hci_power_transition_to_initializing(void){
3803     // set up state machine
3804     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3805     hci_stack->hci_packet_buffer_reserved = false;
3806     hci_stack->state = HCI_STATE_INITIALIZING;
3807     hci_stack->substate = HCI_INIT_SEND_RESET;
3808 }
3809 
3810 // returns error
3811 static int hci_power_control_state_off(HCI_POWER_MODE power_mode){
3812     int err;
3813     switch (power_mode){
3814         case HCI_POWER_ON:
3815             err = hci_power_control_on();
3816             if (err != 0) {
3817                 log_error("hci_power_control_on() error %d", err);
3818                 return err;
3819             }
3820             hci_power_transition_to_initializing();
3821             break;
3822         case HCI_POWER_OFF:
3823             // do nothing
3824             break;
3825         case HCI_POWER_SLEEP:
3826             // do nothing (with SLEEP == OFF)
3827             break;
3828         default:
3829             btstack_assert(false);
3830             break;
3831     }
3832     return ERROR_CODE_SUCCESS;
3833 }
3834 
3835 static int hci_power_control_state_initializing(HCI_POWER_MODE power_mode){
3836     switch (power_mode){
3837         case HCI_POWER_ON:
3838             // do nothing
3839             break;
3840         case HCI_POWER_OFF:
3841             // no connections yet, just turn it off
3842             hci_power_control_off();
3843             break;
3844         case HCI_POWER_SLEEP:
3845             // no connections yet, just turn it off
3846             hci_power_control_sleep();
3847             break;
3848         default:
3849             btstack_assert(false);
3850             break;
3851     }
3852     return ERROR_CODE_SUCCESS;
3853 }
3854 
3855 static int hci_power_control_state_working(HCI_POWER_MODE power_mode) {
3856     switch (power_mode){
3857         case HCI_POWER_ON:
3858             // do nothing
3859             break;
3860         case HCI_POWER_OFF:
3861             // see hci_run
3862             hci_stack->state = HCI_STATE_HALTING;
3863             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3864             break;
3865         case HCI_POWER_SLEEP:
3866             // see hci_run
3867             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3868             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3869             break;
3870         default:
3871             btstack_assert(false);
3872             break;
3873     }
3874     return ERROR_CODE_SUCCESS;
3875 }
3876 
3877 static int hci_power_control_state_halting(HCI_POWER_MODE power_mode) {
3878     switch (power_mode){
3879         case HCI_POWER_ON:
3880             hci_power_transition_to_initializing();
3881             break;
3882         case HCI_POWER_OFF:
3883             // do nothing
3884             break;
3885         case HCI_POWER_SLEEP:
3886             // see hci_run
3887             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3888             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3889             break;
3890         default:
3891             btstack_assert(false);
3892             break;
3893     }
3894     return ERROR_CODE_SUCCESS;
3895 }
3896 
3897 static int hci_power_control_state_falling_asleep(HCI_POWER_MODE power_mode) {
3898     switch (power_mode){
3899         case HCI_POWER_ON:
3900 
3901 #ifdef HAVE_PLATFORM_IPHONE_OS
3902             // nothing to do, if H4 supports power management
3903                     if (btstack_control_iphone_power_management_enabled()){
3904                         hci_stack->state = HCI_STATE_INITIALIZING;
3905                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
3906                         break;
3907                     }
3908 #endif
3909             hci_power_transition_to_initializing();
3910             break;
3911         case HCI_POWER_OFF:
3912             // see hci_run
3913             hci_stack->state = HCI_STATE_HALTING;
3914             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3915             break;
3916         case HCI_POWER_SLEEP:
3917             // do nothing
3918             break;
3919         default:
3920             btstack_assert(false);
3921             break;
3922     }
3923     return ERROR_CODE_SUCCESS;
3924 }
3925 
3926 static int hci_power_control_state_sleeping(HCI_POWER_MODE power_mode) {
3927     int err;
3928     switch (power_mode){
3929         case HCI_POWER_ON:
3930 #ifdef HAVE_PLATFORM_IPHONE_OS
3931             // nothing to do, if H4 supports power management
3932                     if (btstack_control_iphone_power_management_enabled()){
3933                         hci_stack->state = HCI_STATE_INITIALIZING;
3934                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
3935                         hci_update_scan_enable();
3936                         break;
3937                     }
3938 #endif
3939             err = hci_power_control_wake();
3940             if (err) return err;
3941             hci_power_transition_to_initializing();
3942             break;
3943         case HCI_POWER_OFF:
3944             hci_stack->state = HCI_STATE_HALTING;
3945             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3946             break;
3947         case HCI_POWER_SLEEP:
3948             // do nothing
3949             break;
3950         default:
3951             btstack_assert(false);
3952             break;
3953     }
3954     return ERROR_CODE_SUCCESS;
3955 }
3956 
3957 int hci_power_control(HCI_POWER_MODE power_mode){
3958     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
3959     int err = 0;
3960     switch (hci_stack->state){
3961         case HCI_STATE_OFF:
3962             err = hci_power_control_state_off(power_mode);
3963             break;
3964         case HCI_STATE_INITIALIZING:
3965             err = hci_power_control_state_initializing(power_mode);
3966             break;
3967         case HCI_STATE_WORKING:
3968             err = hci_power_control_state_working(power_mode);
3969             break;
3970         case HCI_STATE_HALTING:
3971             err = hci_power_control_state_halting(power_mode);
3972             break;
3973         case HCI_STATE_FALLING_ASLEEP:
3974             err = hci_power_control_state_falling_asleep(power_mode);
3975             break;
3976         case HCI_STATE_SLEEPING:
3977             err = hci_power_control_state_sleeping(power_mode);
3978             break;
3979         default:
3980             btstack_assert(false);
3981             break;
3982     }
3983     if (err != 0){
3984         return err;
3985     }
3986 
3987     // create internal event
3988 	hci_emit_state();
3989 
3990 	// trigger next/first action
3991 	hci_run();
3992 
3993     return 0;
3994 }
3995 
3996 
3997 #ifdef ENABLE_CLASSIC
3998 
3999 static void hci_update_scan_enable(void){
4000     // 2 = page scan, 1 = inq scan
4001     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
4002     hci_run();
4003 }
4004 
4005 void gap_discoverable_control(uint8_t enable){
4006     if (enable) enable = 1; // normalize argument
4007 
4008     if (hci_stack->discoverable == enable){
4009         hci_emit_discoverable_enabled(hci_stack->discoverable);
4010         return;
4011     }
4012 
4013     hci_stack->discoverable = enable;
4014     hci_update_scan_enable();
4015 }
4016 
4017 void gap_connectable_control(uint8_t enable){
4018     if (enable) enable = 1; // normalize argument
4019 
4020     // don't emit event
4021     if (hci_stack->connectable == enable) return;
4022 
4023     hci_stack->connectable = enable;
4024     hci_update_scan_enable();
4025 }
4026 #endif
4027 
4028 void gap_local_bd_addr(bd_addr_t address_buffer){
4029     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
4030 }
4031 
4032 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4033 static void hci_host_num_completed_packets(void){
4034 
4035     // create packet manually as arrays are not supported and num_commands should not get reduced
4036     hci_reserve_packet_buffer();
4037     uint8_t * packet = hci_get_outgoing_packet_buffer();
4038 
4039     uint16_t size = 0;
4040     uint16_t num_handles = 0;
4041     packet[size++] = 0x35;
4042     packet[size++] = 0x0c;
4043     size++;  // skip param len
4044     size++;  // skip num handles
4045 
4046     // add { handle, packets } entries
4047     btstack_linked_item_t * it;
4048     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
4049         hci_connection_t * connection = (hci_connection_t *) it;
4050         if (connection->num_packets_completed){
4051             little_endian_store_16(packet, size, connection->con_handle);
4052             size += 2;
4053             little_endian_store_16(packet, size, connection->num_packets_completed);
4054             size += 2;
4055             //
4056             num_handles++;
4057             connection->num_packets_completed = 0;
4058         }
4059     }
4060 
4061     packet[2] = size - 3;
4062     packet[3] = num_handles;
4063 
4064     hci_stack->host_completed_packets = 0;
4065 
4066     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4067     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4068 
4069     // release packet buffer for synchronous transport implementations
4070     if (hci_transport_synchronous()){
4071         hci_release_packet_buffer();
4072         hci_emit_transport_packet_sent();
4073     }
4074 }
4075 #endif
4076 
4077 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
4078     UNUSED(ds);
4079     hci_stack->substate = HCI_HALTING_CLOSE;
4080     // allow packet handlers to defer final shutdown
4081     hci_emit_state();
4082     hci_run();
4083 }
4084 
4085 static bool hci_run_acl_fragments(void){
4086     if (hci_stack->acl_fragmentation_total_size > 0u) {
4087         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
4088         hci_connection_t *connection = hci_connection_for_handle(con_handle);
4089         if (connection) {
4090             if (hci_can_send_prepared_acl_packet_now(con_handle)){
4091                 hci_send_acl_packet_fragments(connection);
4092                 return true;
4093             }
4094         } else {
4095             // connection gone -> discard further fragments
4096             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
4097             hci_stack->acl_fragmentation_total_size = 0;
4098             hci_stack->acl_fragmentation_pos = 0;
4099         }
4100     }
4101     return false;
4102 }
4103 
4104 #ifdef ENABLE_CLASSIC
4105 static bool hci_run_general_gap_classic(void){
4106 
4107     // assert stack is working and classic is active
4108     if (hci_classic_supported() == false)      return false;
4109     if (hci_stack->state != HCI_STATE_WORKING) return false;
4110 
4111     // decline incoming connections
4112     if (hci_stack->decline_reason){
4113         uint8_t reason = hci_stack->decline_reason;
4114         hci_stack->decline_reason = 0;
4115         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
4116         return true;
4117     }
4118 
4119     if ((hci_stack->gap_tasks & GAP_TASK_SET_CLASS_OF_DEVICE) != 0) {
4120         hci_stack->gap_tasks &= ~GAP_TASK_SET_CLASS_OF_DEVICE;
4121         hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
4122         return true;
4123     }
4124     if ((hci_stack->gap_tasks & GAP_TASK_SET_LOCAL_NAME) != 0) {
4125         hci_stack->gap_tasks &= ~GAP_TASK_SET_LOCAL_NAME;
4126         gap_run_set_local_name();
4127         return true;
4128     }
4129     if ((hci_stack->gap_tasks & GAP_TASK_SET_EIR_DATA) != 0) {
4130         hci_stack->gap_tasks &= ~GAP_TASK_SET_EIR_DATA;
4131         gap_run_set_eir_data();
4132         return true;
4133     }
4134     if ((hci_stack->gap_tasks & GAP_TASK_SET_DEFAULT_LINK_POLICY) != 0) {
4135         hci_stack->gap_tasks &= ~GAP_TASK_SET_DEFAULT_LINK_POLICY;
4136         hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
4137         return true;
4138     }
4139     // write page scan activity
4140     if (hci_stack->new_page_scan_interval != 0xffff) {
4141         uint16_t new_page_scan_interval = hci_stack->new_page_scan_interval;
4142         uint16_t new_page_scan_window = hci_stack->new_page_scan_window;
4143         hci_stack->new_page_scan_interval = 0xffff;
4144         hci_stack->new_page_scan_window = 0xffff;
4145         hci_send_cmd(&hci_write_page_scan_activity, new_page_scan_interval, new_page_scan_window);
4146         return true;
4147     }
4148     // write page scan type
4149     if (hci_stack->new_page_scan_type != 0xff) {
4150         uint8_t new_page_scan_type = hci_stack->new_page_scan_type;
4151         hci_stack->new_page_scan_type = 0xff;
4152         hci_send_cmd(&hci_write_page_scan_type, new_page_scan_type);
4153         return true;
4154     }
4155     // send scan enable
4156     if (hci_stack->new_scan_enable_value != 0xff) {
4157         uint8_t new_scan_enable_value = hci_stack->new_scan_enable_value;
4158         hci_stack->new_scan_enable_value = 0xff;
4159         hci_send_cmd(&hci_write_scan_enable, new_scan_enable_value);
4160         return true;
4161     }
4162 
4163     // start/stop inquiry
4164     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
4165         uint8_t duration = hci_stack->inquiry_state;
4166         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_ACTIVE;
4167         hci_send_cmd(&hci_inquiry, hci_stack->inquiry_lap, duration, 0);
4168         return true;
4169     }
4170     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
4171         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
4172         hci_send_cmd(&hci_inquiry_cancel);
4173         return true;
4174     }
4175     // remote name request
4176     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
4177         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
4178         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
4179                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
4180         return true;
4181     }
4182 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4183     // Local OOB data
4184     if (hci_stack->classic_read_local_oob_data){
4185         hci_stack->classic_read_local_oob_data = false;
4186         if (hci_stack->local_supported_commands[1] & 0x10u){
4187             hci_send_cmd(&hci_read_local_extended_oob_data);
4188         } else {
4189             hci_send_cmd(&hci_read_local_oob_data);
4190         }
4191     }
4192 #endif
4193     // pairing
4194     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
4195         uint8_t state = hci_stack->gap_pairing_state;
4196         uint8_t pin_code[16];
4197         switch (state){
4198             case GAP_PAIRING_STATE_SEND_PIN:
4199                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4200                 memset(pin_code, 0, 16);
4201                 memcpy(pin_code, hci_stack->gap_pairing_input.gap_pairing_pin, hci_stack->gap_pairing_pin_len);
4202                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_pin_len, pin_code);
4203                 break;
4204             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
4205                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4206                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
4207                 break;
4208             case GAP_PAIRING_STATE_SEND_PASSKEY:
4209                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4210                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
4211                 break;
4212             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
4213                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4214                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
4215                 break;
4216             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
4217                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4218                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
4219                 break;
4220             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
4221                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4222                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
4223                 break;
4224             default:
4225                 break;
4226         }
4227         return true;
4228     }
4229     return false;
4230 }
4231 #endif
4232 
4233 #ifdef ENABLE_BLE
4234 static bool hci_run_general_gap_le(void){
4235 
4236     // advertisements, active scanning, and creating connections requires random address to be set if using private address
4237 
4238     if (hci_stack->state != HCI_STATE_WORKING) return false;
4239     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
4240 
4241 
4242     // Phase 1: collect what to stop
4243 
4244     bool scanning_stop = false;
4245     bool connecting_stop = false;
4246     bool advertising_stop = false;
4247 
4248 #ifndef ENABLE_LE_CENTRAL
4249     UNUSED(scanning_stop);
4250     UNUSED(connecting_stop);
4251 #endif
4252 #ifndef ENABLE_LE_PERIPHERAL
4253     UNUSED(advertising_stop);
4254 #endif
4255 
4256     // check if whitelist needs modification
4257     bool whitelist_modification_pending = false;
4258     btstack_linked_list_iterator_t lit;
4259     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4260     while (btstack_linked_list_iterator_has_next(&lit)){
4261         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4262         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
4263             whitelist_modification_pending = true;
4264             break;
4265         }
4266     }
4267     // check if resolving list needs modification
4268     bool resolving_list_modification_pending = false;
4269 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4270     bool resolving_list_supported = (hci_stack->local_supported_commands[1] & (1 << 2)) != 0;
4271 	if (resolving_list_supported && hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_DONE){
4272         resolving_list_modification_pending = true;
4273     }
4274 #endif
4275 
4276 #ifdef ENABLE_LE_CENTRAL
4277     // scanning control
4278     if (hci_stack->le_scanning_active) {
4279         // stop if:
4280         // - parameter change required
4281         // - it's disabled
4282         // - whitelist change required but used for scanning
4283         // - resolving list modified
4284         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
4285         if ((hci_stack->le_scanning_param_update) ||
4286             !hci_stack->le_scanning_enabled ||
4287             scanning_uses_whitelist ||
4288             resolving_list_modification_pending){
4289 
4290             scanning_stop = true;
4291         }
4292     }
4293 #endif
4294 
4295 #ifdef ENABLE_LE_CENTRAL
4296     // connecting control
4297     bool connecting_with_whitelist;
4298     switch (hci_stack->le_connecting_state){
4299         case LE_CONNECTING_DIRECT:
4300         case LE_CONNECTING_WHITELIST:
4301             // stop connecting if:
4302             // - connecting uses white and whitelist modification pending
4303             // - if it got disabled
4304             // - resolving list modified
4305             connecting_with_whitelist = hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST;
4306             if ((connecting_with_whitelist && whitelist_modification_pending) ||
4307                 (hci_stack->le_connecting_request == LE_CONNECTING_IDLE) ||
4308                 resolving_list_modification_pending) {
4309 
4310                 connecting_stop = true;
4311             }
4312             break;
4313         default:
4314             break;
4315     }
4316 #endif
4317 
4318 #ifdef ENABLE_LE_PERIPHERAL
4319     // le advertisement control
4320     if (hci_stack->le_advertisements_active){
4321         // stop if:
4322         // - parameter change required
4323         // - it's disabled
4324         // - whitelist change required but used for advertisement filter policy
4325         // - resolving list modified
4326         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy != 0;
4327         bool advertising_change = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS) != 0;
4328         if (advertising_change ||
4329             (hci_stack->le_advertisements_enabled_for_current_roles == 0) ||
4330             (advertising_uses_whitelist & whitelist_modification_pending) ||
4331             resolving_list_modification_pending) {
4332 
4333             advertising_stop = true;
4334         }
4335     }
4336 #endif
4337 
4338 
4339     // Phase 2: stop everything that should be off during modifications
4340 
4341 #ifdef ENABLE_LE_CENTRAL
4342     if (scanning_stop){
4343         hci_stack->le_scanning_active = false;
4344         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
4345         return true;
4346     }
4347 #endif
4348 
4349 #ifdef ENABLE_LE_CENTRAL
4350     if (connecting_stop){
4351         hci_send_cmd(&hci_le_create_connection_cancel);
4352         return true;
4353     }
4354 #endif
4355 
4356 #ifdef ENABLE_LE_PERIPHERAL
4357     if (advertising_stop){
4358         hci_stack->le_advertisements_active = false;
4359         hci_send_cmd(&hci_le_set_advertise_enable, 0);
4360         return true;
4361     }
4362 #endif
4363 
4364     // Phase 3: modify
4365 
4366 #ifdef ENABLE_LE_CENTRAL
4367     if (hci_stack->le_scanning_param_update){
4368         hci_stack->le_scanning_param_update = false;
4369         hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
4370                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
4371         return true;
4372     }
4373 #endif
4374 
4375 #ifdef ENABLE_LE_PERIPHERAL
4376     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
4377         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
4378         hci_stack->le_advertisements_own_addr_type = hci_stack->le_own_addr_type;
4379         hci_send_cmd(&hci_le_set_advertising_parameters,
4380                      hci_stack->le_advertisements_interval_min,
4381                      hci_stack->le_advertisements_interval_max,
4382                      hci_stack->le_advertisements_type,
4383                      hci_stack->le_advertisements_own_addr_type,
4384                      hci_stack->le_advertisements_direct_address_type,
4385                      hci_stack->le_advertisements_direct_address,
4386                      hci_stack->le_advertisements_channel_map,
4387                      hci_stack->le_advertisements_filter_policy);
4388         return true;
4389     }
4390     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
4391         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
4392         uint8_t adv_data_clean[31];
4393         memset(adv_data_clean, 0, sizeof(adv_data_clean));
4394         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
4395                      hci_stack->le_advertisements_data_len);
4396         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
4397         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
4398         return true;
4399     }
4400     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
4401         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
4402         uint8_t scan_data_clean[31];
4403         memset(scan_data_clean, 0, sizeof(scan_data_clean));
4404         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
4405                      hci_stack->le_scan_response_data_len);
4406         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
4407         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
4408         return true;
4409     }
4410 #endif
4411 
4412 
4413 #ifdef ENABLE_LE_CENTRAL
4414     // if connect with whitelist was active and is not cancelled yet, wait until next time
4415     if (hci_stack->le_connecting_state == LE_CONNECTING_CANCEL) return false;
4416 #endif
4417 
4418     // LE Whitelist Management
4419     if (whitelist_modification_pending){
4420         // add/remove entries
4421         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4422         while (btstack_linked_list_iterator_has_next(&lit)){
4423             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4424 			if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
4425 				entry->state &= ~LE_WHITELIST_REMOVE_FROM_CONTROLLER;
4426 				hci_send_cmd(&hci_le_remove_device_from_white_list, entry->address_type, entry->address);
4427 				return true;
4428 			}
4429             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
4430 				entry->state &= ~LE_WHITELIST_ADD_TO_CONTROLLER;
4431                 entry->state |= LE_WHITELIST_ON_CONTROLLER;
4432                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
4433                 return true;
4434             }
4435             if ((entry->state & LE_WHITELIST_ON_CONTROLLER) == 0){
4436 				btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4437 				btstack_memory_whitelist_entry_free(entry);
4438             }
4439         }
4440     }
4441 
4442 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4443     // LE Resolving List Management
4444     if (resolving_list_supported) {
4445 		uint16_t i;
4446 		switch (hci_stack->le_resolving_list_state) {
4447 			case LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION:
4448 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
4449 				hci_send_cmd(&hci_le_set_address_resolution_enabled, 1);
4450 				return true;
4451 			case LE_RESOLVING_LIST_READ_SIZE:
4452 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_SEND_CLEAR;
4453 				hci_send_cmd(&hci_le_read_resolving_list_size);
4454 				return true;
4455 			case LE_RESOLVING_LIST_SEND_CLEAR:
4456 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
4457 				(void) memset(hci_stack->le_resolving_list_add_entries, 0xff,
4458 							  sizeof(hci_stack->le_resolving_list_add_entries));
4459 				(void) memset(hci_stack->le_resolving_list_remove_entries, 0,
4460 							  sizeof(hci_stack->le_resolving_list_remove_entries));
4461 				hci_send_cmd(&hci_le_clear_resolving_list);
4462 				return true;
4463 			case LE_RESOLVING_LIST_REMOVE_ENTRIES:
4464 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4465 					uint8_t offset = i >> 3;
4466 					uint8_t mask = 1 << (i & 7);
4467 					if ((hci_stack->le_resolving_list_remove_entries[offset] & mask) == 0) continue;
4468 					hci_stack->le_resolving_list_remove_entries[offset] &= ~mask;
4469 					bd_addr_t peer_identity_addreses;
4470 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4471 					sm_key_t peer_irk;
4472 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4473 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4474 
4475 #ifdef ENABLE_LE_WHITELIST_TOUCH_AFTER_RESOLVING_LIST_UPDATE
4476 					// trigger whitelist entry 'update' (work around for controller bug)
4477 					btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4478 					while (btstack_linked_list_iterator_has_next(&lit)) {
4479 						whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&lit);
4480 						if (entry->address_type != peer_identity_addr_type) continue;
4481 						if (memcmp(entry->address, peer_identity_addreses, 6) != 0) continue;
4482 						log_info("trigger whitelist update %s", bd_addr_to_str(peer_identity_addreses));
4483 						entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER;
4484 					}
4485 #endif
4486 
4487 					hci_send_cmd(&hci_le_remove_device_from_resolving_list, peer_identity_addr_type,
4488 								 peer_identity_addreses);
4489 					return true;
4490 				}
4491 
4492 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_ADD_ENTRIES;
4493 
4494 				/* fall through */
4495 
4496 			case LE_RESOLVING_LIST_ADD_ENTRIES:
4497 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4498 					uint8_t offset = i >> 3;
4499 					uint8_t mask = 1 << (i & 7);
4500 					if ((hci_stack->le_resolving_list_add_entries[offset] & mask) == 0) continue;
4501 					hci_stack->le_resolving_list_add_entries[offset] &= ~mask;
4502 					bd_addr_t peer_identity_addreses;
4503 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4504 					sm_key_t peer_irk;
4505 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4506 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4507 					const uint8_t *local_irk = gap_get_persistent_irk();
4508 					// command uses format specifier 'P' that stores 16-byte value without flip
4509 					uint8_t local_irk_flipped[16];
4510 					uint8_t peer_irk_flipped[16];
4511 					reverse_128(local_irk, local_irk_flipped);
4512 					reverse_128(peer_irk, peer_irk_flipped);
4513 					hci_send_cmd(&hci_le_add_device_to_resolving_list, peer_identity_addr_type, peer_identity_addreses,
4514 								 peer_irk_flipped, local_irk_flipped);
4515 					return true;
4516 				}
4517 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4518 				break;
4519 
4520 			default:
4521 				break;
4522 		}
4523 	}
4524     hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4525 #endif
4526 
4527     // Phase 4: restore state
4528 
4529 #ifdef ENABLE_LE_CENTRAL
4530     // re-start scanning
4531     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
4532         hci_stack->le_scanning_active = true;
4533         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
4534         return true;
4535     }
4536 #endif
4537 
4538 #ifdef ENABLE_LE_CENTRAL
4539     // re-start connecting
4540     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
4541         bd_addr_t null_addr;
4542         memset(null_addr, 0, 6);
4543         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4544         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4545         hci_send_cmd(&hci_le_create_connection,
4546                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
4547                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
4548                      1,         // use whitelist
4549                      0,         // peer address type
4550                      null_addr, // peer bd addr
4551                      hci_stack->le_connection_own_addr_type,   // our addr type:
4552                      hci_stack->le_connection_interval_min,    // conn interval min
4553                      hci_stack->le_connection_interval_max,    // conn interval max
4554                      hci_stack->le_connection_latency,         // conn latency
4555                      hci_stack->le_supervision_timeout,        // conn latency
4556                      hci_stack->le_minimum_ce_length,          // min ce length
4557                      hci_stack->le_maximum_ce_length           // max ce length
4558         );
4559         return true;
4560     }
4561 #endif
4562 
4563 #ifdef ENABLE_LE_PERIPHERAL
4564     // re-start advertising
4565     if (hci_stack->le_advertisements_enabled_for_current_roles && !hci_stack->le_advertisements_active){
4566         // check if advertisements should be enabled given
4567         hci_stack->le_advertisements_active = true;
4568         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_advertisements_own_address);
4569         hci_send_cmd(&hci_le_set_advertise_enable, 1);
4570         return true;
4571     }
4572 #endif
4573 
4574     return false;
4575 }
4576 #endif
4577 
4578 static bool hci_run_general_pending_commands(void){
4579     btstack_linked_item_t * it;
4580     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4581         hci_connection_t * connection = (hci_connection_t *) it;
4582 
4583         switch(connection->state){
4584             case SEND_CREATE_CONNECTION:
4585                 switch(connection->address_type){
4586 #ifdef ENABLE_CLASSIC
4587                     case BD_ADDR_TYPE_ACL:
4588                         log_info("sending hci_create_connection");
4589                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
4590                         break;
4591 #endif
4592                     default:
4593 #ifdef ENABLE_BLE
4594 #ifdef ENABLE_LE_CENTRAL
4595                         log_info("sending hci_le_create_connection");
4596                         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4597                         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4598                         hci_send_cmd(&hci_le_create_connection,
4599                                      hci_stack->le_connection_scan_interval,    // conn scan interval
4600                                      hci_stack->le_connection_scan_window,      // conn scan windows
4601                                      0,         // don't use whitelist
4602                                      connection->address_type, // peer address type
4603                                      connection->address,      // peer bd addr
4604                                      hci_stack->le_connection_own_addr_type,   // our addr type:
4605                                      hci_stack->le_connection_interval_min,    // conn interval min
4606                                      hci_stack->le_connection_interval_max,    // conn interval max
4607                                      hci_stack->le_connection_latency,         // conn latency
4608                                      hci_stack->le_supervision_timeout,        // conn latency
4609                                      hci_stack->le_minimum_ce_length,          // min ce length
4610                                      hci_stack->le_maximum_ce_length          // max ce length
4611                         );
4612                         connection->state = SENT_CREATE_CONNECTION;
4613 #endif
4614 #endif
4615                         break;
4616                 }
4617                 return true;
4618 
4619 #ifdef ENABLE_CLASSIC
4620             case RECEIVED_CONNECTION_REQUEST:
4621                 connection->role  = HCI_ROLE_SLAVE;
4622                 if (connection->address_type == BD_ADDR_TYPE_ACL){
4623                     log_info("sending hci_accept_connection_request");
4624                     connection->state = ACCEPTED_CONNECTION_REQUEST;
4625                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
4626                 }
4627                 return true;
4628 #endif
4629 
4630 #ifdef ENABLE_BLE
4631 #ifdef ENABLE_LE_CENTRAL
4632             case SEND_CANCEL_CONNECTION:
4633                 connection->state = SENT_CANCEL_CONNECTION;
4634                 hci_send_cmd(&hci_le_create_connection_cancel);
4635                 return true;
4636 #endif
4637 #endif
4638             case SEND_DISCONNECT:
4639                 connection->state = SENT_DISCONNECT;
4640                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4641                 return true;
4642 
4643             default:
4644                 break;
4645         }
4646 
4647         // no further commands if connection is about to get shut down
4648         if (connection->state == SENT_DISCONNECT) continue;
4649 
4650         if (connection->authentication_flags & AUTH_FLAG_READ_RSSI){
4651             connectionClearAuthenticationFlags(connection, AUTH_FLAG_READ_RSSI);
4652             hci_send_cmd(&hci_read_rssi, connection->con_handle);
4653             return true;
4654         }
4655 
4656 #ifdef ENABLE_CLASSIC
4657 
4658         if (connection->authentication_flags & AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT){
4659             connectionClearAuthenticationFlags(connection, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
4660             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
4661             return true;
4662         }
4663 
4664         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
4665             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
4666             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
4667             return true;
4668         }
4669 
4670         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
4671             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
4672             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
4673             return true;
4674         }
4675 
4676         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
4677             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
4678             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
4679             return true;
4680         }
4681 
4682         // Handling link key request requires remote supported features
4683         if (((connection->authentication_flags & AUTH_FLAG_HANDLE_LINK_KEY_REQUEST) != 0)){
4684             log_info("responding to link key request, have link key db: %u", hci_stack->link_key_db != NULL);
4685             connectionClearAuthenticationFlags(connection, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
4686 
4687             // lookup link key using cached key first
4688             bool have_link_key = connection->link_key_type != INVALID_LINK_KEY;
4689             if (!have_link_key && (hci_stack->link_key_db != NULL)){
4690                 have_link_key = hci_stack->link_key_db->get_link_key(connection->address, connection->link_key, &connection->link_key_type);
4691             }
4692 
4693             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(connection->link_key_type) >= connection->requested_security_level);
4694             if (have_link_key && security_level_sufficient){
4695                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &connection->link_key);
4696             } else {
4697                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
4698             }
4699             return true;
4700         }
4701 
4702         if (connection->authentication_flags & AUTH_FLAG_DENY_PIN_CODE_REQUEST){
4703             log_info("denying to pin request");
4704             connectionClearAuthenticationFlags(connection, AUTH_FLAG_DENY_PIN_CODE_REQUEST);
4705             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
4706             return true;
4707         }
4708 
4709         // security assessment requires remote features
4710         if (((connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST) != 0) && ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0)){
4711             connectionClearAuthenticationFlags(connection, AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
4712             hci_ssp_assess_security_on_io_cap_request(connection);
4713             // 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
4714         }
4715 
4716         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY){
4717             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
4718             // set authentication requirements:
4719             // - MITM = ssp_authentication_requirement (USER) | requested_security_level (dynamic)
4720             // - BONDING MODE: dedicated if requested, bondable otherwise. Drop bondable if not set for remote
4721             uint8_t authreq = hci_stack->ssp_authentication_requirement & 1;
4722             if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
4723                 authreq |= 1;
4724             }
4725             bool bonding = hci_stack->bondable;
4726             if (connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
4727                 // if we have received IO Cap Response, we're in responder role
4728                 bool remote_bonding = connection->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4729                 if (bonding && !remote_bonding){
4730                     log_info("Remote not bonding, dropping local flag");
4731                     bonding = false;
4732                 }
4733             }
4734             if (bonding){
4735                 if (connection->bonding_flags & BONDING_DEDICATED){
4736                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4737                 } else {
4738                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
4739                 }
4740             }
4741             uint8_t have_oob_data = 0;
4742 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4743             if (connection->classic_oob_c_192 != NULL){
4744                     have_oob_data |= 1;
4745             }
4746             if (connection->classic_oob_c_256 != NULL){
4747                 have_oob_data |= 2;
4748             }
4749 #endif
4750             hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, have_oob_data, authreq);
4751             return true;
4752         }
4753 
4754         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY) {
4755             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
4756             hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
4757             return true;
4758         }
4759 
4760 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4761         if (connection->authentication_flags & AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY){
4762             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
4763             const uint8_t zero[16] = { 0 };
4764             const uint8_t * r_192 = zero;
4765             const uint8_t * c_192 = zero;
4766             const uint8_t * r_256 = zero;
4767             const uint8_t * c_256 = zero;
4768             // verify P-256 OOB
4769             if ((connection->classic_oob_c_256 != NULL) && ((hci_stack->local_supported_commands[1] & 0x08u) != 0)) {
4770                 c_256 = connection->classic_oob_c_256;
4771                 if (connection->classic_oob_r_256 != NULL) {
4772                     r_256 = connection->classic_oob_r_256;
4773                 }
4774             }
4775             // verify P-192 OOB
4776             if ((connection->classic_oob_c_192 != NULL)) {
4777                 c_192 = connection->classic_oob_c_192;
4778                 if (connection->classic_oob_r_192 != NULL) {
4779                     r_192 = connection->classic_oob_r_192;
4780                 }
4781             }
4782 
4783             // assess security
4784             bool need_level_4 = hci_stack->gap_secure_connections_only_mode || (connection->requested_security_level == LEVEL_4);
4785             bool can_reach_level_4 = hci_remote_sc_enabled(connection) && (c_256 != NULL);
4786             if (need_level_4 && !can_reach_level_4){
4787                 log_info("Level 4 required, but not possible -> abort");
4788                 hci_pairing_complete(connection, ERROR_CODE_INSUFFICIENT_SECURITY);
4789                 // send oob negative reply
4790                 c_256 = NULL;
4791                 c_192 = NULL;
4792             }
4793 
4794             // Reply
4795             if (c_256 != zero) {
4796                 hci_send_cmd(&hci_remote_oob_extended_data_request_reply, &connection->address, c_192, r_192, c_256, r_256);
4797             } else if (c_192 != zero){
4798                 hci_send_cmd(&hci_remote_oob_data_request_reply, &connection->address, c_192, r_192);
4799             } else {
4800                 hci_stack->classic_oob_con_handle = connection->con_handle;
4801                 hci_send_cmd(&hci_remote_oob_data_request_negative_reply, &connection->address);
4802             }
4803             return true;
4804         }
4805 #endif
4806 
4807         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_REPLY){
4808             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
4809             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
4810             return true;
4811         }
4812 
4813         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY){
4814             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
4815             hci_send_cmd(&hci_user_confirmation_request_negative_reply, &connection->address);
4816             return true;
4817         }
4818 
4819         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_PASSKEY_REPLY){
4820             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
4821             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
4822             return true;
4823         }
4824 
4825         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
4826             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
4827             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
4828             connection->state = SENT_DISCONNECT;
4829             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4830             return true;
4831         }
4832 
4833         if ((connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST) && ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0)){
4834             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
4835             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
4836             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
4837             return true;
4838         }
4839 
4840         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
4841             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
4842             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
4843             return true;
4844         }
4845         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
4846             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
4847             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
4848             return true;
4849         }
4850 #endif
4851 
4852         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
4853             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
4854 #ifdef ENABLE_CLASSIC
4855             hci_pairing_complete(connection, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_SECURITY_REASONS);
4856 #endif
4857             if (connection->state != SENT_DISCONNECT){
4858                 connection->state = SENT_DISCONNECT;
4859                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4860                 return true;
4861             }
4862         }
4863 
4864 #ifdef ENABLE_CLASSIC
4865         uint16_t sniff_min_interval;
4866         switch (connection->sniff_min_interval){
4867             case 0:
4868                 break;
4869             case 0xffff:
4870                 connection->sniff_min_interval = 0;
4871                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
4872                 return true;
4873             default:
4874                 sniff_min_interval = connection->sniff_min_interval;
4875                 connection->sniff_min_interval = 0;
4876                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
4877                 return true;
4878         }
4879 
4880         if (connection->sniff_subrating_max_latency != 0xffff){
4881             uint16_t max_latency = connection->sniff_subrating_max_latency;
4882             connection->sniff_subrating_max_latency = 0;
4883             hci_send_cmd(&hci_sniff_subrating, connection->con_handle, max_latency, connection->sniff_subrating_min_remote_timeout, connection->sniff_subrating_min_local_timeout);
4884             return true;
4885         }
4886 
4887         if (connection->qos_service_type != HCI_SERVICE_TYPE_INVALID){
4888             uint8_t service_type = (uint8_t) connection->qos_service_type;
4889             connection->qos_service_type = HCI_SERVICE_TYPE_INVALID;
4890             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);
4891             return true;
4892         }
4893 
4894         if (connection->request_role != HCI_ROLE_INVALID){
4895             hci_role_t role = connection->request_role;
4896             connection->request_role = HCI_ROLE_INVALID;
4897             hci_send_cmd(&hci_switch_role_command, connection->address, role);
4898             return true;
4899         }
4900 #endif
4901 
4902 #ifdef ENABLE_BLE
4903         switch (connection->le_con_parameter_update_state){
4904             // response to L2CAP CON PARAMETER UPDATE REQUEST
4905             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
4906                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4907                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
4908                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4909                              0x0000, 0xffff);
4910                 return true;
4911             case CON_PARAMETER_UPDATE_REPLY:
4912                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4913                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
4914                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4915                              0x0000, 0xffff);
4916                 return true;
4917             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
4918                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4919                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
4920                 return true;
4921             default:
4922                 break;
4923         }
4924         if (connection->le_phy_update_all_phys != 0xffu){
4925             uint8_t all_phys = connection->le_phy_update_all_phys;
4926             connection->le_phy_update_all_phys = 0xff;
4927             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);
4928             return true;
4929         }
4930 #endif
4931     }
4932     return false;
4933 }
4934 
4935 static void hci_run(void){
4936 
4937     bool done;
4938 
4939     // send continuation fragments first, as they block the prepared packet buffer
4940     done = hci_run_acl_fragments();
4941     if (done) return;
4942 
4943 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4944     // send host num completed packets next as they don't require num_cmd_packets > 0
4945     if (!hci_can_send_comand_packet_transport()) return;
4946     if (hci_stack->host_completed_packets){
4947         hci_host_num_completed_packets();
4948         return;
4949     }
4950 #endif
4951 
4952     if (!hci_can_send_command_packet_now()) return;
4953 
4954     // global/non-connection oriented commands
4955 
4956 
4957 #ifdef ENABLE_CLASSIC
4958     // general gap classic
4959     done = hci_run_general_gap_classic();
4960     if (done) return;
4961 #endif
4962 
4963 #ifdef ENABLE_BLE
4964     // general gap le
4965     done = hci_run_general_gap_le();
4966     if (done) return;
4967 #endif
4968 
4969     // send pending HCI commands
4970     done = hci_run_general_pending_commands();
4971     if (done) return;
4972 
4973     // stack state sub statemachines
4974     hci_connection_t * connection;
4975     switch (hci_stack->state){
4976         case HCI_STATE_INITIALIZING:
4977             hci_initializing_run();
4978             break;
4979 
4980         case HCI_STATE_HALTING:
4981 
4982             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4983             switch (hci_stack->substate){
4984                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4985                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
4986 
4987 #ifdef ENABLE_BLE
4988 #ifdef ENABLE_LE_CENTRAL
4989                     // free whitelist entries
4990                     {
4991                         btstack_linked_list_iterator_t lit;
4992                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4993                         while (btstack_linked_list_iterator_has_next(&lit)){
4994                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4995                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4996                             btstack_memory_whitelist_entry_free(entry);
4997                         }
4998                     }
4999 #endif
5000 #endif
5001                     // close all open connections
5002                     connection =  (hci_connection_t *) hci_stack->connections;
5003                     if (connection){
5004                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
5005                         if (!hci_can_send_command_packet_now()) return;
5006 
5007                         // check state
5008                         if (connection->state == SENT_DISCONNECT) return;
5009                         connection->state = SENT_DISCONNECT;
5010 
5011                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
5012 
5013                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
5014                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
5015 
5016                         // ... which would be ignored anyway as we shutdown (free) the connection now
5017                         hci_shutdown_connection(connection);
5018 
5019                         // finally, send the disconnect command
5020                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5021                         return;
5022                     }
5023 
5024                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
5025                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
5026                         log_info("HCI_STATE_HALTING: wait 50 ms");
5027                         hci_stack->substate = HCI_HALTING_W4_TIMER;
5028                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
5029                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
5030                         btstack_run_loop_add_timer(&hci_stack->timeout);
5031                         break;
5032                     }
5033 
5034                     /* fall through */
5035 
5036                 case HCI_HALTING_CLOSE:
5037                     log_info("HCI_STATE_HALTING, calling off");
5038 
5039                     // switch mode
5040                     hci_power_control_off();
5041 
5042                     log_info("HCI_STATE_HALTING, emitting state");
5043                     hci_emit_state();
5044                     log_info("HCI_STATE_HALTING, done");
5045                     break;
5046 
5047                 case HCI_HALTING_W4_TIMER:
5048                     // keep waiting
5049 
5050                     break;
5051                 default:
5052                     break;
5053             }
5054 
5055             break;
5056 
5057         case HCI_STATE_FALLING_ASLEEP:
5058             switch(hci_stack->substate) {
5059                 case HCI_FALLING_ASLEEP_DISCONNECT:
5060                     log_info("HCI_STATE_FALLING_ASLEEP");
5061                     // close all open connections
5062                     connection =  (hci_connection_t *) hci_stack->connections;
5063 
5064 #ifdef HAVE_PLATFORM_IPHONE_OS
5065                     // don't close connections, if H4 supports power management
5066                     if (btstack_control_iphone_power_management_enabled()){
5067                         connection = NULL;
5068                     }
5069 #endif
5070                     if (connection){
5071 
5072                         // send disconnect
5073                         if (!hci_can_send_command_packet_now()) return;
5074 
5075                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
5076                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5077 
5078                         // send disconnected event right away - causes higher layer connections to get closed, too.
5079                         hci_shutdown_connection(connection);
5080                         return;
5081                     }
5082 
5083                     if (hci_classic_supported()){
5084                         // disable page and inquiry scan
5085                         if (!hci_can_send_command_packet_now()) return;
5086 
5087                         log_info("HCI_STATE_HALTING, disabling inq scans");
5088                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
5089 
5090                         // continue in next sub state
5091                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
5092                         break;
5093                     }
5094 
5095                     /* fall through */
5096 
5097                 case HCI_FALLING_ASLEEP_COMPLETE:
5098                     log_info("HCI_STATE_HALTING, calling sleep");
5099 #ifdef HAVE_PLATFORM_IPHONE_OS
5100                     // don't actually go to sleep, if H4 supports power management
5101                     if (btstack_control_iphone_power_management_enabled()){
5102                         // SLEEP MODE reached
5103                         hci_stack->state = HCI_STATE_SLEEPING;
5104                         hci_emit_state();
5105                         break;
5106                     }
5107 #endif
5108                     // switch mode
5109                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
5110                     hci_emit_state();
5111                     break;
5112 
5113                 default:
5114                     break;
5115             }
5116             break;
5117 
5118         default:
5119             break;
5120     }
5121 }
5122 
5123 uint8_t hci_send_cmd_packet(uint8_t *packet, int size){
5124     // house-keeping
5125 
5126 #ifdef ENABLE_CLASSIC
5127     bd_addr_t addr;
5128     hci_connection_t * conn;
5129 #endif
5130 #ifdef ENABLE_LE_CENTRAL
5131     uint8_t initiator_filter_policy;
5132 #endif
5133 
5134     uint16_t opcode = little_endian_read_16(packet, 0);
5135     switch (opcode) {
5136         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
5137             hci_stack->loopback_mode = packet[3];
5138             break;
5139 
5140 #ifdef ENABLE_CLASSIC
5141         case HCI_OPCODE_HCI_CREATE_CONNECTION:
5142             reverse_bd_addr(&packet[3], addr);
5143             log_info("Create_connection to %s", bd_addr_to_str(addr));
5144 
5145             // CVE-2020-26555: reject outgoing connection to device with same BD ADDR
5146             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0) {
5147                 hci_emit_connection_complete(addr, 0, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR);
5148                 return ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
5149             }
5150 
5151             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5152             if (!conn) {
5153                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5154                 if (!conn) {
5155                     // notify client that alloc failed
5156                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5157                     return BTSTACK_MEMORY_ALLOC_FAILED; // packet not sent to controller
5158                 }
5159                 conn->state = SEND_CREATE_CONNECTION;
5160                 conn->role  = HCI_ROLE_MASTER;
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         case HCI_OPCODE_HCI_DELETE_STORED_LINK_KEY:
5189             if (hci_stack->link_key_db) {
5190                 reverse_bd_addr(&packet[3], addr);
5191                 hci_stack->link_key_db->delete_link_key(addr);
5192             }
5193             break;
5194 
5195 #if defined (ENABLE_SCO_OVER_HCI) || defined (HAVE_SCO_TRANSPORT)
5196         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
5197             // setup_synchronous_connection? Voice setting at offset 22
5198             // TODO: compare to current setting if sco connection already active
5199             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
5200             break;
5201         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
5202             // accept_synchronus_connection? Voice setting at offset 18
5203             // TODO: compare to current setting if sco connection already active
5204             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
5205             break;
5206 #endif
5207 #endif
5208 
5209 #ifdef ENABLE_BLE
5210         case HCI_OPCODE_HCI_LE_SET_RANDOM_ADDRESS:
5211             hci_stack->le_random_address_set = 1;
5212             reverse_bd_addr(&packet[3], hci_stack->le_random_address);
5213             break;
5214 #ifdef ENABLE_LE_PERIPHERAL
5215         case HCI_OPCODE_HCI_LE_SET_ADVERTISE_ENABLE:
5216             hci_stack->le_advertisements_active = packet[3] != 0;
5217             break;
5218 #endif
5219 #ifdef ENABLE_LE_CENTRAL
5220         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
5221             // white list used?
5222             initiator_filter_policy = packet[7];
5223             switch (initiator_filter_policy) {
5224                 case 0:
5225                     // whitelist not used
5226                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
5227                     break;
5228                 case 1:
5229                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
5230                     break;
5231                 default:
5232                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
5233                     break;
5234             }
5235             // track outgoing connection
5236             hci_stack->outgoing_addr_type = (bd_addr_type_t) packet[8]; // peer addres type
5237             reverse_bd_addr( &packet[9], hci_stack->outgoing_addr); // peer address
5238             break;
5239         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
5240             hci_stack->le_connecting_state = LE_CONNECTING_CANCEL;
5241             break;
5242 #endif
5243 #endif
5244         default:
5245             break;
5246     }
5247 
5248     hci_stack->num_cmd_packets--;
5249 
5250     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
5251     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
5252     if (err != 0){
5253         return ERROR_CODE_HARDWARE_FAILURE;
5254     }
5255     return ERROR_CODE_SUCCESS;
5256 }
5257 
5258 // disconnect because of security block
5259 void hci_disconnect_security_block(hci_con_handle_t con_handle){
5260     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5261     if (!connection) return;
5262     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
5263 }
5264 
5265 
5266 // Configure Secure Simple Pairing
5267 
5268 #ifdef ENABLE_CLASSIC
5269 
5270 // enable will enable SSP during init
5271 void gap_ssp_set_enable(int enable){
5272     hci_stack->ssp_enable = enable;
5273 }
5274 
5275 static int hci_local_ssp_activated(void){
5276     return gap_ssp_supported() && hci_stack->ssp_enable;
5277 }
5278 
5279 // if set, BTstack will respond to io capability request using authentication requirement
5280 void gap_ssp_set_io_capability(int io_capability){
5281     hci_stack->ssp_io_capability = io_capability;
5282 }
5283 void gap_ssp_set_authentication_requirement(int authentication_requirement){
5284     hci_stack->ssp_authentication_requirement = authentication_requirement;
5285 }
5286 
5287 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
5288 void gap_ssp_set_auto_accept(int auto_accept){
5289     hci_stack->ssp_auto_accept = auto_accept;
5290 }
5291 
5292 void gap_secure_connections_enable(bool enable){
5293     hci_stack->secure_connections_enable = enable;
5294 }
5295 
5296 #endif
5297 
5298 // va_list part of hci_send_cmd
5299 uint8_t hci_send_cmd_va_arg(const hci_cmd_t * cmd, va_list argptr){
5300     if (!hci_can_send_command_packet_now()){
5301         log_error("hci_send_cmd called but cannot send packet now");
5302         return ERROR_CODE_COMMAND_DISALLOWED;
5303     }
5304 
5305     // for HCI INITIALIZATION
5306     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
5307     hci_stack->last_cmd_opcode = cmd->opcode;
5308 
5309     hci_reserve_packet_buffer();
5310     uint8_t * packet = hci_stack->hci_packet_buffer;
5311     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
5312     uint8_t status = hci_send_cmd_packet(packet, size);
5313 
5314     // release packet buffer on error or for synchronous transport implementations
5315     if ((status != ERROR_CODE_SUCCESS) || hci_transport_synchronous()){
5316         hci_release_packet_buffer();
5317         hci_emit_transport_packet_sent();
5318     }
5319 
5320     return status;
5321 }
5322 
5323 /**
5324  * pre: numcmds >= 0 - it's allowed to send a command to the controller
5325  */
5326 uint8_t hci_send_cmd(const hci_cmd_t * cmd, ...){
5327     va_list argptr;
5328     va_start(argptr, cmd);
5329     uint8_t status = hci_send_cmd_va_arg(cmd, argptr);
5330     va_end(argptr);
5331     return status;
5332 }
5333 
5334 // Create various non-HCI events.
5335 // TODO: generalize, use table similar to hci_create_command
5336 
5337 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
5338     // dump packet
5339     if (dump) {
5340         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
5341     }
5342 
5343     // dispatch to all event handlers
5344     btstack_linked_list_iterator_t it;
5345     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
5346     while (btstack_linked_list_iterator_has_next(&it)){
5347         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
5348         entry->callback(HCI_EVENT_PACKET, 0, event, size);
5349     }
5350 }
5351 
5352 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
5353     if (!hci_stack->acl_packet_handler) return;
5354     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
5355 }
5356 
5357 #ifdef ENABLE_CLASSIC
5358 static void hci_notify_if_sco_can_send_now(void){
5359     // notify SCO sender if waiting
5360     if (!hci_stack->sco_waiting_for_can_send_now) return;
5361     if (hci_can_send_sco_packet_now()){
5362         hci_stack->sco_waiting_for_can_send_now = 0;
5363         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
5364         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
5365         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
5366     }
5367 }
5368 
5369 // parsing end emitting has been merged to reduce code size
5370 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
5371     uint8_t event[28+GAP_INQUIRY_MAX_NAME_LEN];
5372 
5373     uint8_t * eir_data;
5374     ad_context_t context;
5375     const uint8_t * name;
5376     uint8_t         name_len;
5377 
5378     if (size < 3) return;
5379 
5380     int event_type = hci_event_packet_get_type(packet);
5381     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
5382     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
5383 
5384     switch (event_type){
5385         case HCI_EVENT_INQUIRY_RESULT:
5386         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5387             if (size != (3 + (num_responses * 14))) return;
5388             break;
5389         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5390             if (size != 257) return;
5391             if (num_responses != 1) return;
5392             break;
5393         default:
5394             return;
5395     }
5396 
5397     // event[1] is set at the end
5398     int i;
5399     for (i=0; i<num_responses;i++){
5400         memset(event, 0, sizeof(event));
5401         event[0] = GAP_EVENT_INQUIRY_RESULT;
5402         uint8_t event_size = 27;    // if name is not set by EIR
5403 
5404         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
5405         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
5406         (void)memcpy(&event[9],
5407                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
5408                      3); // class of device
5409         (void)memcpy(&event[12],
5410                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
5411                      2); // clock offset
5412 
5413         switch (event_type){
5414             case HCI_EVENT_INQUIRY_RESULT:
5415                 // 14,15,16,17 = 0, size 18
5416                 break;
5417             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5418                 event[14] = 1;
5419                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5420                 // 16,17 = 0, size 18
5421                 break;
5422             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5423                 event[14] = 1;
5424                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5425                 // EIR packets only contain a single inquiry response
5426                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
5427                 name = NULL;
5428                 // Iterate over EIR data
5429                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
5430                     uint8_t data_type    = ad_iterator_get_data_type(&context);
5431                     uint8_t data_size    = ad_iterator_get_data_len(&context);
5432                     const uint8_t * data = ad_iterator_get_data(&context);
5433                     // Prefer Complete Local Name over Shortened Local Name
5434                     switch (data_type){
5435                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
5436                             if (name) continue;
5437                             /* fall through */
5438                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
5439                             name = data;
5440                             name_len = data_size;
5441                             break;
5442                         case BLUETOOTH_DATA_TYPE_DEVICE_ID:
5443                             if (data_size != 8) break;
5444                             event[16] = 1;
5445                             memcpy(&event[17], data, 8);
5446                             break;
5447                         default:
5448                             break;
5449                     }
5450                 }
5451                 if (name){
5452                     event[25] = 1;
5453                     // truncate name if needed
5454                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
5455                     event[26] = len;
5456                     (void)memcpy(&event[27], name, len);
5457                     event_size += len;
5458                 }
5459                 break;
5460             default:
5461                 return;
5462         }
5463         event[1] = event_size - 2;
5464         hci_emit_event(event, event_size, 1);
5465     }
5466 }
5467 #endif
5468 
5469 void hci_emit_state(void){
5470     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
5471     uint8_t event[3];
5472     event[0] = BTSTACK_EVENT_STATE;
5473     event[1] = sizeof(event) - 2u;
5474     event[2] = hci_stack->state;
5475     hci_emit_event(event, sizeof(event), 1);
5476 }
5477 
5478 #ifdef ENABLE_CLASSIC
5479 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5480     uint8_t event[13];
5481     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
5482     event[1] = sizeof(event) - 2;
5483     event[2] = status;
5484     little_endian_store_16(event, 3, con_handle);
5485     reverse_bd_addr(address, &event[5]);
5486     event[11] = 1; // ACL connection
5487     event[12] = 0; // encryption disabled
5488     hci_emit_event(event, sizeof(event), 1);
5489 }
5490 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
5491     if (disable_l2cap_timeouts) return;
5492     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
5493     uint8_t event[4];
5494     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
5495     event[1] = sizeof(event) - 2;
5496     little_endian_store_16(event, 2, conn->con_handle);
5497     hci_emit_event(event, sizeof(event), 1);
5498 }
5499 #endif
5500 
5501 #ifdef ENABLE_BLE
5502 #ifdef ENABLE_LE_CENTRAL
5503 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){
5504     uint8_t event[21];
5505     event[0] = HCI_EVENT_LE_META;
5506     event[1] = sizeof(event) - 2u;
5507     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
5508     event[3] = status;
5509     little_endian_store_16(event, 4, con_handle);
5510     event[6] = 0; // TODO: role
5511     event[7] = address_type;
5512     reverse_bd_addr(address, &event[8]);
5513     little_endian_store_16(event, 14, 0); // interval
5514     little_endian_store_16(event, 16, 0); // latency
5515     little_endian_store_16(event, 18, 0); // supervision timeout
5516     event[20] = 0; // master clock accuracy
5517     hci_emit_event(event, sizeof(event), 1);
5518 }
5519 #endif
5520 #endif
5521 
5522 static void hci_emit_transport_packet_sent(void){
5523     // notify upper stack that it might be possible to send again
5524     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
5525     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
5526 }
5527 
5528 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
5529     uint8_t event[6];
5530     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
5531     event[1] = sizeof(event) - 2u;
5532     event[2] = 0; // status = OK
5533     little_endian_store_16(event, 3, con_handle);
5534     event[5] = reason;
5535     hci_emit_event(event, sizeof(event), 1);
5536 }
5537 
5538 static void hci_emit_nr_connections_changed(void){
5539     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
5540     uint8_t event[3];
5541     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
5542     event[1] = sizeof(event) - 2u;
5543     event[2] = nr_hci_connections();
5544     hci_emit_event(event, sizeof(event), 1);
5545 }
5546 
5547 static void hci_emit_hci_open_failed(void){
5548     log_info("BTSTACK_EVENT_POWERON_FAILED");
5549     uint8_t event[2];
5550     event[0] = BTSTACK_EVENT_POWERON_FAILED;
5551     event[1] = sizeof(event) - 2u;
5552     hci_emit_event(event, sizeof(event), 1);
5553 }
5554 
5555 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
5556     log_info("hci_emit_dedicated_bonding_result %u ", status);
5557     uint8_t event[9];
5558     int pos = 0;
5559     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
5560     event[pos++] = sizeof(event) - 2u;
5561     event[pos++] = status;
5562     reverse_bd_addr(address, &event[pos]);
5563     hci_emit_event(event, sizeof(event), 1);
5564 }
5565 
5566 
5567 #ifdef ENABLE_CLASSIC
5568 
5569 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
5570     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
5571     uint8_t event[5];
5572     int pos = 0;
5573     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
5574     event[pos++] = sizeof(event) - 2;
5575     little_endian_store_16(event, 2, con_handle);
5576     pos += 2;
5577     event[pos++] = level;
5578     hci_emit_event(event, sizeof(event), 1);
5579 }
5580 
5581 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
5582     if (!connection) return LEVEL_0;
5583     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
5584     // BIAS: we only consider Authenticated if the connection is already encrypted, which requires that both sides have link key
5585     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
5586     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
5587     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
5588     // LEVEL 4 always requires 128 bit encrytion key size
5589     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
5590         security_level = LEVEL_3;
5591     }
5592     return security_level;
5593 }
5594 
5595 static void hci_emit_discoverable_enabled(uint8_t enabled){
5596     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
5597     uint8_t event[3];
5598     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
5599     event[1] = sizeof(event) - 2;
5600     event[2] = enabled;
5601     hci_emit_event(event, sizeof(event), 1);
5602 }
5603 
5604 // query if remote side supports eSCO
5605 bool hci_remote_esco_supported(hci_con_handle_t con_handle){
5606     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5607     if (!connection) return false;
5608     return (connection->remote_supported_features[0] & 1) != 0;
5609 }
5610 
5611 static bool hci_ssp_supported(hci_connection_t * connection){
5612     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
5613     return (connection->bonding_flags & mask) == mask;
5614 }
5615 
5616 // query if remote side supports SSP
5617 bool hci_remote_ssp_supported(hci_con_handle_t con_handle){
5618     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5619     if (!connection) return false;
5620     return hci_ssp_supported(connection) ? 1 : 0;
5621 }
5622 
5623 bool gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
5624     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
5625 }
5626 
5627 // GAP API
5628 /**
5629  * @bbrief enable/disable bonding. default is enabled
5630  * @praram enabled
5631  */
5632 void gap_set_bondable_mode(int enable){
5633     hci_stack->bondable = enable ? 1 : 0;
5634 }
5635 /**
5636  * @brief Get bondable mode.
5637  * @return 1 if bondable
5638  */
5639 int gap_get_bondable_mode(void){
5640     return hci_stack->bondable;
5641 }
5642 
5643 /**
5644  * @brief map link keys to security levels
5645  */
5646 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
5647     switch (link_key_type){
5648         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5649             return LEVEL_4;
5650         case COMBINATION_KEY:
5651         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5652             return LEVEL_3;
5653         default:
5654             return LEVEL_2;
5655     }
5656 }
5657 
5658 /**
5659  * @brief map link keys to secure connection yes/no
5660  */
5661 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
5662     switch (link_key_type){
5663         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5664         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5665             return 1;
5666         default:
5667             return 0;
5668     }
5669 }
5670 
5671 /**
5672  * @brief map link keys to authenticated
5673  */
5674 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
5675     switch (link_key_type){
5676         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5677         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5678             return 1;
5679         default:
5680             return 0;
5681     }
5682 }
5683 
5684 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
5685     log_info("gap_mitm_protection_required_for_security_level %u", level);
5686     return level > LEVEL_2;
5687 }
5688 
5689 /**
5690  * @brief get current security level
5691  */
5692 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
5693     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5694     if (!connection) return LEVEL_0;
5695     return gap_security_level_for_connection(connection);
5696 }
5697 
5698 /**
5699  * @brief request connection to device to
5700  * @result GAP_AUTHENTICATION_RESULT
5701  */
5702 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
5703     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5704     if (!connection){
5705         hci_emit_security_level(con_handle, LEVEL_0);
5706         return;
5707     }
5708 
5709     btstack_assert(hci_is_le_connection(connection) == false);
5710 
5711     // 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)
5712     // available on the BR/EDR physical transport require Security Mode 4, Level 4 "
5713     if (hci_stack->gap_secure_connections_only_mode && (requested_level != LEVEL_0)){
5714         requested_level = LEVEL_4;
5715     }
5716 
5717     gap_security_level_t current_level = gap_security_level(con_handle);
5718     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
5719         requested_level, connection->requested_security_level, current_level);
5720 
5721     // authentication active if authentication request was sent or planned level > 0
5722     bool authentication_active = ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) || (connection->requested_security_level > LEVEL_0);
5723     if (authentication_active){
5724         // authentication already active
5725         if (connection->requested_security_level < requested_level){
5726             // increase requested level as new level is higher
5727             // TODO: handle re-authentication when done
5728             connection->requested_security_level = requested_level;
5729         }
5730     } else {
5731         // no request active, notify if security sufficient
5732         if (requested_level <= current_level){
5733             hci_emit_security_level(con_handle, current_level);
5734             return;
5735         }
5736 
5737         // store request
5738         connection->requested_security_level = requested_level;
5739 
5740         // start to authenticate connection
5741         connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
5742         hci_run();
5743     }
5744 }
5745 
5746 /**
5747  * @brief start dedicated bonding with device. disconnect after bonding
5748  * @param device
5749  * @param request MITM protection
5750  * @result GAP_DEDICATED_BONDING_COMPLETE
5751  */
5752 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
5753 
5754     // create connection state machine
5755     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
5756 
5757     if (!connection){
5758         return BTSTACK_MEMORY_ALLOC_FAILED;
5759     }
5760 
5761     // delete linkn key
5762     gap_drop_link_key_for_bd_addr(device);
5763 
5764     // configure LEVEL_2/3, dedicated bonding
5765     connection->state = SEND_CREATE_CONNECTION;
5766     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
5767     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
5768     connection->bonding_flags = BONDING_DEDICATED;
5769 
5770     // wait for GAP Security Result and send GAP Dedicated Bonding complete
5771 
5772     // handle: connnection failure (connection complete != ok)
5773     // handle: authentication failure
5774     // handle: disconnect on done
5775 
5776     hci_run();
5777 
5778     return 0;
5779 }
5780 #endif
5781 
5782 void gap_set_local_name(const char * local_name){
5783     hci_stack->local_name = local_name;
5784     hci_stack->gap_tasks |= GAP_TASK_SET_LOCAL_NAME;
5785     // also update EIR if not set by user
5786     if (hci_stack->eir_data == NULL){
5787         hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
5788     }
5789     hci_run();
5790 }
5791 
5792 
5793 #ifdef ENABLE_BLE
5794 
5795 #ifdef ENABLE_LE_CENTRAL
5796 void gap_start_scan(void){
5797     hci_stack->le_scanning_enabled = true;
5798     hci_run();
5799 }
5800 
5801 void gap_stop_scan(void){
5802     hci_stack->le_scanning_enabled = false;
5803     hci_run();
5804 }
5805 
5806 void gap_set_scan_params(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window, uint8_t scanning_filter_policy){
5807     hci_stack->le_scan_type          = scan_type;
5808     hci_stack->le_scan_filter_policy = scanning_filter_policy;
5809     hci_stack->le_scan_interval      = scan_interval;
5810     hci_stack->le_scan_window        = scan_window;
5811     hci_stack->le_scanning_param_update = true;
5812     hci_run();
5813 }
5814 
5815 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
5816     gap_set_scan_params(scan_type, scan_interval, scan_window, 0);
5817 }
5818 
5819 uint8_t gap_connect(const bd_addr_t addr, bd_addr_type_t addr_type){
5820     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
5821     if (!conn){
5822         // disallow if le connection is already outgoing
5823         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5824             log_error("le connection already active");
5825             return ERROR_CODE_COMMAND_DISALLOWED;
5826         }
5827 
5828         log_info("gap_connect: no connection exists yet, creating context");
5829         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
5830         if (!conn){
5831             // notify client that alloc failed
5832             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5833             log_info("gap_connect: failed to alloc hci_connection_t");
5834             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
5835         }
5836 
5837         // set le connecting state
5838         if (hci_is_le_connection_type(addr_type)){
5839             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
5840         }
5841 
5842         conn->state = SEND_CREATE_CONNECTION;
5843         log_info("gap_connect: send create connection next");
5844         hci_run();
5845         return ERROR_CODE_SUCCESS;
5846     }
5847 
5848     if (!hci_is_le_connection(conn) ||
5849         (conn->state == SEND_CREATE_CONNECTION) ||
5850         (conn->state == SENT_CREATE_CONNECTION)) {
5851         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
5852         log_error("gap_connect: classic connection or connect is already being created");
5853         return GATT_CLIENT_IN_WRONG_STATE;
5854     }
5855 
5856     // check if connection was just disconnected
5857     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5858         log_info("gap_connect: send create connection (again)");
5859         conn->state = SEND_CREATE_CONNECTION;
5860         hci_run();
5861         return ERROR_CODE_SUCCESS;
5862     }
5863 
5864     log_info("gap_connect: context exists with state %u", conn->state);
5865     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
5866     hci_run();
5867     return ERROR_CODE_SUCCESS;
5868 }
5869 
5870 // @assumption: only a single outgoing LE Connection exists
5871 static hci_connection_t * gap_get_outgoing_connection(void){
5872     btstack_linked_item_t *it;
5873     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5874         hci_connection_t * conn = (hci_connection_t *) it;
5875         if (!hci_is_le_connection(conn)) continue;
5876         switch (conn->state){
5877             case SEND_CREATE_CONNECTION:
5878             case SENT_CREATE_CONNECTION:
5879             case SENT_CANCEL_CONNECTION:
5880                 return conn;
5881             default:
5882                 break;
5883         };
5884     }
5885     return NULL;
5886 }
5887 
5888 uint8_t gap_connect_cancel(void){
5889     hci_connection_t * conn = gap_get_outgoing_connection();
5890     if (!conn) return 0;
5891     switch (conn->state){
5892         case SEND_CREATE_CONNECTION:
5893             // skip sending create connection and emit event instead
5894             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5895             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5896             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5897             btstack_memory_hci_connection_free( conn );
5898             break;
5899         case SENT_CREATE_CONNECTION:
5900             // request to send cancel connection
5901             conn->state = SEND_CANCEL_CONNECTION;
5902             hci_run();
5903             break;
5904         default:
5905             break;
5906     }
5907     return 0;
5908 }
5909 #endif
5910 
5911 #ifdef ENABLE_LE_CENTRAL
5912 /**
5913  * @brief Set connection parameters for outgoing connections
5914  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5915  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5916  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5917  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5918  * @param conn_latency, default: 4
5919  * @param supervision_timeout (unit: 10ms), default: 720 ms
5920  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5921  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5922  */
5923 
5924 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5925     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5926     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5927     hci_stack->le_connection_scan_interval = conn_scan_interval;
5928     hci_stack->le_connection_scan_window = conn_scan_window;
5929     hci_stack->le_connection_interval_min = conn_interval_min;
5930     hci_stack->le_connection_interval_max = conn_interval_max;
5931     hci_stack->le_connection_latency = conn_latency;
5932     hci_stack->le_supervision_timeout = supervision_timeout;
5933     hci_stack->le_minimum_ce_length = min_ce_length;
5934     hci_stack->le_maximum_ce_length = max_ce_length;
5935 }
5936 #endif
5937 
5938 /**
5939  * @brief Updates the connection parameters for a given LE connection
5940  * @param handle
5941  * @param conn_interval_min (unit: 1.25ms)
5942  * @param conn_interval_max (unit: 1.25ms)
5943  * @param conn_latency
5944  * @param supervision_timeout (unit: 10ms)
5945  * @returns 0 if ok
5946  */
5947 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5948     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5949     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5950     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5951     connection->le_conn_interval_min = conn_interval_min;
5952     connection->le_conn_interval_max = conn_interval_max;
5953     connection->le_conn_latency = conn_latency;
5954     connection->le_supervision_timeout = supervision_timeout;
5955     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5956     hci_run();
5957     return 0;
5958 }
5959 
5960 /**
5961  * @brief Request an update of the connection parameter for a given LE connection
5962  * @param handle
5963  * @param conn_interval_min (unit: 1.25ms)
5964  * @param conn_interval_max (unit: 1.25ms)
5965  * @param conn_latency
5966  * @param supervision_timeout (unit: 10ms)
5967  * @returns 0 if ok
5968  */
5969 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5970     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5971     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5972     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5973     connection->le_conn_interval_min = conn_interval_min;
5974     connection->le_conn_interval_max = conn_interval_max;
5975     connection->le_conn_latency = conn_latency;
5976     connection->le_supervision_timeout = supervision_timeout;
5977     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5978     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5979     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5980     return 0;
5981 }
5982 
5983 #ifdef ENABLE_LE_PERIPHERAL
5984 
5985 /**
5986  * @brief Set Advertisement Data
5987  * @param advertising_data_length
5988  * @param advertising_data (max 31 octets)
5989  * @note data is not copied, pointer has to stay valid
5990  */
5991 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
5992     hci_stack->le_advertisements_data_len = advertising_data_length;
5993     hci_stack->le_advertisements_data = advertising_data;
5994     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
5995     hci_run();
5996 }
5997 
5998 /**
5999  * @brief Set Scan Response Data
6000  * @param advertising_data_length
6001  * @param advertising_data (max 31 octets)
6002  * @note data is not copied, pointer has to stay valid
6003  */
6004 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
6005     hci_stack->le_scan_response_data_len = scan_response_data_length;
6006     hci_stack->le_scan_response_data = scan_response_data;
6007     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
6008     hci_run();
6009 }
6010 
6011 /**
6012  * @brief Set Advertisement Parameters
6013  * @param adv_int_min
6014  * @param adv_int_max
6015  * @param adv_type
6016  * @param direct_address_type
6017  * @param direct_address
6018  * @param channel_map
6019  * @param filter_policy
6020  *
6021  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
6022  */
6023  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
6024     uint8_t direct_address_typ, bd_addr_t direct_address,
6025     uint8_t channel_map, uint8_t filter_policy) {
6026 
6027     hci_stack->le_advertisements_interval_min = adv_int_min;
6028     hci_stack->le_advertisements_interval_max = adv_int_max;
6029     hci_stack->le_advertisements_type = adv_type;
6030     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
6031     hci_stack->le_advertisements_channel_map = channel_map;
6032     hci_stack->le_advertisements_filter_policy = filter_policy;
6033     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
6034                  6);
6035 
6036     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS | LE_ADVERTISEMENT_TASKS_PARAMS_SET;
6037     hci_run();
6038  }
6039 
6040 /**
6041  * @brief Enable/Disable Advertisements
6042  * @param enabled
6043  */
6044 void gap_advertisements_enable(int enabled){
6045     hci_stack->le_advertisements_enabled = enabled != 0;
6046     hci_update_advertisements_enabled_for_current_roles();
6047     hci_run();
6048 }
6049 
6050 #endif
6051 
6052 void hci_le_set_own_address_type(uint8_t own_address_type){
6053     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
6054     if (own_address_type == hci_stack->le_own_addr_type) return;
6055     hci_stack->le_own_addr_type = own_address_type;
6056 
6057 #ifdef ENABLE_LE_PERIPHERAL
6058     // update advertisement parameters, too
6059     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
6060     hci_run();
6061 #endif
6062 #ifdef ENABLE_LE_CENTRAL
6063     // note: we don't update scan parameters or modify ongoing connection attempts
6064 #endif
6065 }
6066 
6067 #endif
6068 
6069 uint8_t gap_disconnect(hci_con_handle_t handle){
6070     hci_connection_t * conn = hci_connection_for_handle(handle);
6071     if (!conn){
6072         hci_emit_disconnection_complete(handle, 0);
6073         return 0;
6074     }
6075     // ignore if already disconnected
6076     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
6077         return 0;
6078     }
6079     conn->state = SEND_DISCONNECT;
6080     hci_run();
6081     return 0;
6082 }
6083 
6084 int gap_read_rssi(hci_con_handle_t con_handle){
6085     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6086     if (hci_connection == NULL) return 0;
6087     connectionSetAuthenticationFlags(hci_connection, AUTH_FLAG_READ_RSSI);
6088     hci_run();
6089     return 1;
6090 }
6091 
6092 /**
6093  * @brief Get connection type
6094  * @param con_handle
6095  * @result connection_type
6096  */
6097 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
6098     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6099     if (!conn) return GAP_CONNECTION_INVALID;
6100     switch (conn->address_type){
6101         case BD_ADDR_TYPE_LE_PUBLIC:
6102         case BD_ADDR_TYPE_LE_RANDOM:
6103             return GAP_CONNECTION_LE;
6104         case BD_ADDR_TYPE_SCO:
6105             return GAP_CONNECTION_SCO;
6106         case BD_ADDR_TYPE_ACL:
6107             return GAP_CONNECTION_ACL;
6108         default:
6109             return GAP_CONNECTION_INVALID;
6110     }
6111 }
6112 
6113 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
6114     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6115     if (!conn) return HCI_ROLE_INVALID;
6116     return (hci_role_t) conn->role;
6117 }
6118 
6119 
6120 #ifdef ENABLE_CLASSIC
6121 uint8_t gap_request_role(const bd_addr_t addr, hci_role_t role){
6122     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6123     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6124     conn->request_role = role;
6125     hci_run();
6126     return ERROR_CODE_SUCCESS;
6127 }
6128 #endif
6129 
6130 #ifdef ENABLE_BLE
6131 
6132 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){
6133     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6134     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6135 
6136     conn->le_phy_update_all_phys    = all_phys;
6137     conn->le_phy_update_tx_phys     = tx_phys;
6138     conn->le_phy_update_rx_phys     = rx_phys;
6139     conn->le_phy_update_phy_options = phy_options;
6140 
6141     hci_run();
6142 
6143     return 0;
6144 }
6145 
6146 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6147     // check if already in list
6148     btstack_linked_list_iterator_t it;
6149     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6150     while (btstack_linked_list_iterator_has_next(&it)) {
6151         whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&it);
6152         if (entry->address_type != address_type) {
6153             continue;
6154         }
6155         if (memcmp(entry->address, address, 6) != 0) {
6156             continue;
6157         }
6158 		// disallow if already scheduled to add
6159 		if ((entry->state & LE_WHITELIST_ADD_TO_CONTROLLER) != 0){
6160 			return ERROR_CODE_COMMAND_DISALLOWED;
6161 		}
6162 		// still on controller, but scheduled to remove -> re-add
6163 		entry->state |= LE_WHITELIST_ADD_TO_CONTROLLER;
6164 		return ERROR_CODE_SUCCESS;
6165     }
6166     // alloc and add to list
6167     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
6168     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
6169     entry->address_type = address_type;
6170     (void)memcpy(entry->address, address, 6);
6171     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
6172     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
6173     return ERROR_CODE_SUCCESS;
6174 }
6175 
6176 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6177     btstack_linked_list_iterator_t it;
6178     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6179     while (btstack_linked_list_iterator_has_next(&it)){
6180         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6181         if (entry->address_type != address_type) {
6182             continue;
6183         }
6184         if (memcmp(entry->address, address, 6) != 0) {
6185             continue;
6186         }
6187         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6188             // remove from controller if already present
6189             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6190         }  else {
6191             // directly remove entry from whitelist
6192             btstack_linked_list_iterator_remove(&it);
6193             btstack_memory_whitelist_entry_free(entry);
6194         }
6195         return ERROR_CODE_SUCCESS;
6196     }
6197     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6198 }
6199 
6200 static void hci_whitelist_clear(void){
6201     btstack_linked_list_iterator_t it;
6202     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6203     while (btstack_linked_list_iterator_has_next(&it)){
6204         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6205         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6206             // remove from controller if already present
6207             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6208             continue;
6209         }
6210         // directly remove entry from whitelist
6211         btstack_linked_list_iterator_remove(&it);
6212         btstack_memory_whitelist_entry_free(entry);
6213     }
6214 }
6215 
6216 /**
6217  * @brief Clear Whitelist
6218  * @returns 0 if ok
6219  */
6220 uint8_t gap_whitelist_clear(void){
6221     hci_whitelist_clear();
6222     hci_run();
6223     return ERROR_CODE_SUCCESS;
6224 }
6225 
6226 /**
6227  * @brief Add Device to Whitelist
6228  * @param address_typ
6229  * @param address
6230  * @returns 0 if ok
6231  */
6232 uint8_t gap_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6233     uint8_t status = hci_whitelist_add(address_type, address);
6234     if (status){
6235         return status;
6236     }
6237     hci_run();
6238     return ERROR_CODE_SUCCESS;
6239 }
6240 
6241 /**
6242  * @brief Remove Device from Whitelist
6243  * @param address_typ
6244  * @param address
6245  * @returns 0 if ok
6246  */
6247 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6248     uint8_t status = hci_whitelist_remove(address_type, address);
6249     if (status){
6250         return status;
6251     }
6252     hci_run();
6253     return ERROR_CODE_SUCCESS;
6254 }
6255 
6256 #ifdef ENABLE_LE_CENTRAL
6257 /**
6258  *  @brief Connect with Whitelist
6259  *  @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
6260  *  @returns - if ok
6261  */
6262 uint8_t gap_connect_with_whitelist(void){
6263     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
6264         return ERROR_CODE_COMMAND_DISALLOWED;
6265     }
6266     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6267     hci_run();
6268     return ERROR_CODE_SUCCESS;
6269 }
6270 
6271 /**
6272  * @brief Auto Connection Establishment - Start Connecting to device
6273  * @param address_typ
6274  * @param address
6275  * @returns 0 if ok
6276  */
6277 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, const bd_addr_t address){
6278     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6279         return ERROR_CODE_COMMAND_DISALLOWED;
6280     }
6281 
6282     uint8_t status = hci_whitelist_add(address_type, address);
6283     if (status == BTSTACK_MEMORY_ALLOC_FAILED) {
6284         return status;
6285     }
6286 
6287     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6288 
6289     hci_run();
6290     return ERROR_CODE_SUCCESS;
6291 }
6292 
6293 /**
6294  * @brief Auto Connection Establishment - Stop Connecting to device
6295  * @param address_typ
6296  * @param address
6297  * @returns 0 if ok
6298  */
6299 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, const bd_addr_t address){
6300     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6301         return ERROR_CODE_COMMAND_DISALLOWED;
6302     }
6303 
6304     hci_whitelist_remove(address_type, address);
6305     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
6306         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6307     }
6308     hci_run();
6309     return 0;
6310 }
6311 
6312 /**
6313  * @brief Auto Connection Establishment - Stop everything
6314  * @note  Convenience function to stop all active auto connection attempts
6315  */
6316 uint8_t gap_auto_connection_stop_all(void){
6317     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
6318         return ERROR_CODE_COMMAND_DISALLOWED;
6319     }
6320     hci_whitelist_clear();
6321     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6322     hci_run();
6323     return ERROR_CODE_SUCCESS;
6324 }
6325 
6326 uint16_t gap_le_connection_interval(hci_con_handle_t con_handle){
6327     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6328     if (!conn) return 0;
6329     return conn->le_connection_interval;
6330 }
6331 #endif
6332 #endif
6333 
6334 #ifdef ENABLE_CLASSIC
6335 /**
6336  * @brief Set Extended Inquiry Response data
6337  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
6338  * @note has to be done before stack starts up
6339  */
6340 void gap_set_extended_inquiry_response(const uint8_t * data){
6341     hci_stack->eir_data = data;
6342     hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
6343     hci_run();
6344 }
6345 
6346 /**
6347  * @brief Start GAP Classic Inquiry
6348  * @param duration in 1.28s units
6349  * @return 0 if ok
6350  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
6351  */
6352 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
6353     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
6354     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6355     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
6356         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
6357     }
6358     hci_stack->inquiry_state = duration_in_1280ms_units;
6359     hci_run();
6360     return 0;
6361 }
6362 
6363 /**
6364  * @brief Stop GAP Classic Inquiry
6365  * @returns 0 if ok
6366  */
6367 int gap_inquiry_stop(void){
6368     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
6369         // emit inquiry complete event, before it even started
6370         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
6371         hci_emit_event(event, sizeof(event), 1);
6372         return 0;
6373     }
6374     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
6375     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
6376     hci_run();
6377     return 0;
6378 }
6379 
6380 void gap_inquiry_set_lap(uint32_t lap){
6381     hci_stack->inquiry_lap = lap;
6382 }
6383 
6384 
6385 /**
6386  * @brief Remote Name Request
6387  * @param addr
6388  * @param page_scan_repetition_mode
6389  * @param clock_offset only used when bit 15 is set
6390  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
6391  */
6392 int gap_remote_name_request(const bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
6393     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6394     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
6395     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
6396     hci_stack->remote_name_clock_offset = clock_offset;
6397     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
6398     hci_run();
6399     return 0;
6400 }
6401 
6402 static int gap_pairing_set_state_and_run(const bd_addr_t addr, uint8_t state){
6403     hci_stack->gap_pairing_state = state;
6404     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
6405     hci_run();
6406     return 0;
6407 }
6408 
6409 /**
6410  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
6411  * @param addr
6412  * @param pin_data
6413  * @param pin_len
6414  * @return 0 if ok
6415  */
6416 int gap_pin_code_response_binary(const bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
6417     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6418     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
6419     hci_stack->gap_pairing_pin_len = pin_len;
6420     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
6421 }
6422 
6423 /**
6424  * @brief Legacy Pairing Pin Code Response
6425  * @param addr
6426  * @param pin
6427  * @return 0 if ok
6428  */
6429 int gap_pin_code_response(const bd_addr_t addr, const char * pin){
6430     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
6431 }
6432 
6433 /**
6434  * @brief Abort Legacy Pairing
6435  * @param addr
6436  * @param pin
6437  * @return 0 if ok
6438  */
6439 int gap_pin_code_negative(bd_addr_t addr){
6440     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6441     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
6442 }
6443 
6444 /**
6445  * @brief SSP Passkey Response
6446  * @param addr
6447  * @param passkey
6448  * @return 0 if ok
6449  */
6450 int gap_ssp_passkey_response(const bd_addr_t addr, uint32_t passkey){
6451     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6452     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
6453     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
6454 }
6455 
6456 /**
6457  * @brief Abort SSP Passkey Entry/Pairing
6458  * @param addr
6459  * @param pin
6460  * @return 0 if ok
6461  */
6462 int gap_ssp_passkey_negative(const bd_addr_t addr){
6463     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6464     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
6465 }
6466 
6467 /**
6468  * @brief Accept SSP Numeric Comparison
6469  * @param addr
6470  * @param passkey
6471  * @return 0 if ok
6472  */
6473 int gap_ssp_confirmation_response(const bd_addr_t addr){
6474     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6475     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
6476 }
6477 
6478 /**
6479  * @brief Abort SSP Numeric Comparison/Pairing
6480  * @param addr
6481  * @param pin
6482  * @return 0 if ok
6483  */
6484 int gap_ssp_confirmation_negative(const bd_addr_t addr){
6485     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6486     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
6487 }
6488 
6489 #ifdef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
6490 
6491 static uint8_t gap_set_auth_flag_and_run(const bd_addr_t addr, hci_authentication_flags_t flag){
6492     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6493     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6494     connectionSetAuthenticationFlags(conn, flag);
6495     hci_run();
6496     return ERROR_CODE_SUCCESS;
6497 }
6498 
6499 uint8_t gap_ssp_io_capabilities_response(const bd_addr_t addr){
6500     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
6501 }
6502 
6503 uint8_t gap_ssp_io_capabilities_negative(const bd_addr_t addr){
6504     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
6505 }
6506 #endif
6507 
6508 #ifdef ENABLE_CLASSIC_PAIRING_OOB
6509 /**
6510  * @brief Report Remote OOB Data
6511  * @param bd_addr
6512  * @param c_192 Simple Pairing Hash C derived from P-192 public key
6513  * @param r_192 Simple Pairing Randomizer derived from P-192 public key
6514  * @param c_256 Simple Pairing Hash C derived from P-256 public key
6515  * @param r_256 Simple Pairing Randomizer derived from P-256 public key
6516  */
6517 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){
6518     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6519     if (connection == NULL) {
6520         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6521     }
6522     connection->classic_oob_c_192 = c_192;
6523     connection->classic_oob_r_192 = r_192;
6524 
6525     // ignore P-256 if not supported by us
6526     if (hci_stack->secure_connections_active){
6527         connection->classic_oob_c_256 = c_256;
6528         connection->classic_oob_r_256 = r_256;
6529     }
6530 
6531     return ERROR_CODE_SUCCESS;
6532 }
6533 /**
6534  * @brief Generate new OOB data
6535  * @note OOB data will be provided in GAP_EVENT_LOCAL_OOB_DATA and be used in future pairing procedures
6536  */
6537 void gap_ssp_generate_oob_data(void){
6538     hci_stack->classic_read_local_oob_data = true;
6539     hci_run();
6540 }
6541 
6542 #endif
6543 
6544 /**
6545  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
6546  * @param inquiry_mode see bluetooth_defines.h
6547  */
6548 void hci_set_inquiry_mode(inquiry_mode_t inquiry_mode){
6549     hci_stack->inquiry_mode = inquiry_mode;
6550 }
6551 
6552 /**
6553  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
6554  */
6555 void hci_set_sco_voice_setting(uint16_t voice_setting){
6556     hci_stack->sco_voice_setting = voice_setting;
6557 }
6558 
6559 /**
6560  * @brief Get SCO Voice Setting
6561  * @return current voice setting
6562  */
6563 uint16_t hci_get_sco_voice_setting(void){
6564     return hci_stack->sco_voice_setting;
6565 }
6566 
6567 static int hci_have_usb_transport(void){
6568     if (!hci_stack->hci_transport) return 0;
6569     const char * transport_name = hci_stack->hci_transport->name;
6570     if (!transport_name) return 0;
6571     return (transport_name[0] == 'H') && (transport_name[1] == '2');
6572 }
6573 
6574 /** @brief Get SCO packet length for current SCO Voice setting
6575  *  @note  Using SCO packets of the exact length is required for USB transfer
6576  *  @return Length of SCO packets in bytes (not audio frames)
6577  */
6578 uint16_t hci_get_sco_packet_length(void){
6579     uint16_t sco_packet_length = 0;
6580 
6581 #ifdef ENABLE_SCO_OVER_HCI
6582     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6583     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6584 
6585     if (hci_have_usb_transport()){
6586         // see Core Spec for H2 USB Transfer.
6587         // 3 byte SCO header + 24 bytes per connection
6588         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
6589         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
6590     } else {
6591         // 3 byte SCO header + SCO packet size over the air (60 bytes)
6592         sco_packet_length = 3 + 60 * multiplier;
6593         // assert that it still fits inside an SCO buffer
6594         if (sco_packet_length > hci_stack->sco_data_packet_length){
6595             sco_packet_length = 3 + 60;
6596         }
6597     }
6598 #endif
6599 
6600 #ifdef HAVE_SCO_TRANSPORT
6601     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6602     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6603     sco_packet_length = 3 + 60 * multiplier;
6604 #endif
6605     return sco_packet_length;
6606 }
6607 
6608 /**
6609 * @brief Sets the master/slave policy
6610 * @param policy (0: attempt to become master, 1: let connecting device decide)
6611 */
6612 void hci_set_master_slave_policy(uint8_t policy){
6613     hci_stack->master_slave_policy = policy;
6614 }
6615 
6616 #endif
6617 
6618 HCI_STATE hci_get_state(void){
6619     return hci_stack->state;
6620 }
6621 
6622 #ifdef ENABLE_CLASSIC
6623 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr, hci_link_type_t link_type)){
6624     hci_stack->gap_classic_accept_callback = accept_callback;
6625 }
6626 #endif
6627 
6628 /**
6629  * @brief Set callback for Bluetooth Hardware Error
6630  */
6631 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
6632     hci_stack->hardware_error_callback = fn;
6633 }
6634 
6635 void hci_disconnect_all(void){
6636     btstack_linked_list_iterator_t it;
6637     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6638     while (btstack_linked_list_iterator_has_next(&it)){
6639         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6640         if (con->state == SENT_DISCONNECT) continue;
6641         con->state = SEND_DISCONNECT;
6642     }
6643     hci_run();
6644 }
6645 
6646 uint16_t hci_get_manufacturer(void){
6647     return hci_stack->manufacturer;
6648 }
6649 
6650 #ifdef ENABLE_BLE
6651 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
6652     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
6653     if (!hci_con) return NULL;
6654     return &hci_con->sm_connection;
6655 }
6656 
6657 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
6658 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
6659 #endif
6660 
6661 int gap_encryption_key_size(hci_con_handle_t con_handle){
6662     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6663     if (hci_connection == NULL) return 0;
6664     if (hci_is_le_connection(hci_connection)){
6665 #ifdef ENABLE_BLE
6666         sm_connection_t * sm_conn = &hci_connection->sm_connection;
6667         if (sm_conn->sm_connection_encrypted) {
6668             return sm_conn->sm_actual_encryption_key_size;
6669         }
6670 #endif
6671     } else {
6672 #ifdef ENABLE_CLASSIC
6673         if ((hci_connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED)){
6674             return hci_connection->encryption_key_size;
6675         }
6676 #endif
6677     }
6678     return 0;
6679 }
6680 
6681 int gap_authenticated(hci_con_handle_t con_handle){
6682     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6683     if (hci_connection == NULL) return 0;
6684 
6685     switch (hci_connection->address_type){
6686 #ifdef ENABLE_BLE
6687         case BD_ADDR_TYPE_LE_PUBLIC:
6688         case BD_ADDR_TYPE_LE_RANDOM:
6689             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6690             return hci_connection->sm_connection.sm_connection_authenticated;
6691 #endif
6692 #ifdef ENABLE_CLASSIC
6693         case BD_ADDR_TYPE_SCO:
6694         case BD_ADDR_TYPE_ACL:
6695             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
6696 #endif
6697         default:
6698             return 0;
6699     }
6700 }
6701 
6702 int gap_secure_connection(hci_con_handle_t con_handle){
6703     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6704     if (hci_connection == NULL) return 0;
6705 
6706     switch (hci_connection->address_type){
6707 #ifdef ENABLE_BLE
6708         case BD_ADDR_TYPE_LE_PUBLIC:
6709         case BD_ADDR_TYPE_LE_RANDOM:
6710             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6711             return hci_connection->sm_connection.sm_connection_sc;
6712 #endif
6713 #ifdef ENABLE_CLASSIC
6714         case BD_ADDR_TYPE_SCO:
6715         case BD_ADDR_TYPE_ACL:
6716             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
6717 #endif
6718         default:
6719             return 0;
6720     }
6721 }
6722 
6723 bool gap_bonded(hci_con_handle_t con_handle){
6724 	hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6725 	if (hci_connection == NULL) return 0;
6726 
6727 #ifdef ENABLE_CLASSIC
6728 	link_key_t link_key;
6729 	link_key_type_t link_key_type;
6730 #endif
6731 	switch (hci_connection->address_type){
6732 #ifdef ENABLE_BLE
6733 		case BD_ADDR_TYPE_LE_PUBLIC:
6734 		case BD_ADDR_TYPE_LE_RANDOM:
6735 			return hci_connection->sm_connection.sm_le_db_index >= 0;
6736 #endif
6737 #ifdef ENABLE_CLASSIC
6738 		case BD_ADDR_TYPE_SCO:
6739 		case BD_ADDR_TYPE_ACL:
6740 			return hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(hci_connection->address, link_key, &link_key_type);
6741 #endif
6742 		default:
6743 			return false;
6744 	}
6745 }
6746 
6747 #ifdef ENABLE_BLE
6748 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
6749     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
6750     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
6751     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
6752     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
6753     return sm_conn->sm_connection_authorization_state;
6754 }
6755 #endif
6756 
6757 #ifdef ENABLE_CLASSIC
6758 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){
6759     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6760     if (!conn) return GAP_CONNECTION_INVALID;
6761     conn->sniff_min_interval = sniff_min_interval;
6762     conn->sniff_max_interval = sniff_max_interval;
6763     conn->sniff_attempt = sniff_attempt;
6764     conn->sniff_timeout = sniff_timeout;
6765     hci_run();
6766     return 0;
6767 }
6768 
6769 /**
6770  * @brief Exit Sniff mode
6771  * @param con_handle
6772  @ @return 0 if ok
6773  */
6774 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
6775     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6776     if (!conn) return GAP_CONNECTION_INVALID;
6777     conn->sniff_min_interval = 0xffff;
6778     hci_run();
6779     return 0;
6780 }
6781 
6782 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){
6783     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6784     if (!conn) return GAP_CONNECTION_INVALID;
6785     conn->sniff_subrating_max_latency = max_latency;
6786     conn->sniff_subrating_min_remote_timeout = min_remote_timeout;
6787     conn->sniff_subrating_min_local_timeout = min_local_timeout;
6788     hci_run();
6789     return ERROR_CODE_SUCCESS;
6790 }
6791 
6792 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){
6793     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6794     if (!conn) return GAP_CONNECTION_INVALID;
6795     conn->qos_service_type = service_type;
6796     conn->qos_token_rate = token_rate;
6797     conn->qos_peak_bandwidth = peak_bandwidth;
6798     conn->qos_latency = latency;
6799     conn->qos_delay_variation = delay_variation;
6800     hci_run();
6801     return ERROR_CODE_SUCCESS;
6802 }
6803 
6804 void gap_set_page_scan_activity(uint16_t page_scan_interval, uint16_t page_scan_window){
6805     hci_stack->new_page_scan_interval = page_scan_interval;
6806     hci_stack->new_page_scan_window = page_scan_window;
6807     hci_run();
6808 }
6809 
6810 void gap_set_page_scan_type(page_scan_type_t page_scan_type){
6811     hci_stack->new_page_scan_type = (uint8_t) page_scan_type;
6812     hci_run();
6813 }
6814 
6815 #endif
6816 
6817 void hci_halting_defer(void){
6818     if (hci_stack->state != HCI_STATE_HALTING) return;
6819     switch (hci_stack->substate){
6820         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
6821         case HCI_HALTING_CLOSE:
6822             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
6823             break;
6824         default:
6825             break;
6826     }
6827 }
6828 
6829 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
6830 void hci_load_le_device_db_entry_into_resolving_list(uint16_t le_device_db_index){
6831     if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6832     if (le_device_db_index >= le_device_db_max_count()) return;
6833     uint8_t offset = le_device_db_index >> 3;
6834     uint8_t mask = 1 << (le_device_db_index & 7);
6835     hci_stack->le_resolving_list_add_entries[offset] |= mask;
6836     if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6837     	// note: go back to remove entries, otherwise, a remove + add will skip the add
6838         hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6839     }
6840 }
6841 
6842 void hci_remove_le_device_db_entry_from_resolving_list(uint16_t le_device_db_index){
6843 	if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6844 	if (le_device_db_index >= le_device_db_max_count()) return;
6845 	uint8_t offset = le_device_db_index >> 3;
6846 	uint8_t mask = 1 << (le_device_db_index & 7);
6847 	hci_stack->le_resolving_list_remove_entries[offset] |= mask;
6848 	if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6849 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6850 	}
6851 }
6852 
6853 uint8_t gap_load_resolving_list_from_le_device_db(void){
6854 	if ((hci_stack->local_supported_commands[1] & (1 << 2)) == 0) {
6855 		return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
6856 	}
6857 	if (hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION){
6858 		// restart le resolving list update
6859 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
6860 	}
6861 	return ERROR_CODE_SUCCESS;
6862 }
6863 #endif
6864 
6865 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
6866 void hci_setup_test_connections_fuzz(void){
6867     hci_connection_t * conn;
6868 
6869     // default address: 66:55:44:33:00:01
6870     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
6871 
6872     // setup Controller info
6873     hci_stack->num_cmd_packets = 255;
6874     hci_stack->acl_packets_total_num = 255;
6875 
6876     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
6877     addr[5] = 0x01;
6878     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6879     conn->con_handle = addr[5];
6880     conn->role  = HCI_ROLE_SLAVE;
6881     conn->state = RECEIVED_CONNECTION_REQUEST;
6882     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6883 
6884     // setup incoming Classic SCO connection with con handle 0x0002
6885     addr[5] = 0x02;
6886     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6887     conn->con_handle = addr[5];
6888     conn->role  = HCI_ROLE_SLAVE;
6889     conn->state = RECEIVED_CONNECTION_REQUEST;
6890     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6891 
6892     // setup ready Classic ACL connection with con handle 0x0003
6893     addr[5] = 0x03;
6894     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6895     conn->con_handle = addr[5];
6896     conn->role  = HCI_ROLE_SLAVE;
6897     conn->state = OPEN;
6898     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6899 
6900     // setup ready Classic SCO connection with con handle 0x0004
6901     addr[5] = 0x04;
6902     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6903     conn->con_handle = addr[5];
6904     conn->role  = HCI_ROLE_SLAVE;
6905     conn->state = OPEN;
6906     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6907 
6908     // setup ready LE ACL connection with con handle 0x005 and public address
6909     addr[5] = 0x05;
6910     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
6911     conn->con_handle = addr[5];
6912     conn->role  = HCI_ROLE_SLAVE;
6913     conn->state = OPEN;
6914     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6915     conn->sm_connection.sm_connection_encrypted = 1;
6916 }
6917 
6918 void hci_free_connections_fuzz(void){
6919     btstack_linked_list_iterator_t it;
6920     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6921     while (btstack_linked_list_iterator_has_next(&it)){
6922         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6923         btstack_linked_list_iterator_remove(&it);
6924         btstack_memory_hci_connection_free(con);
6925     }
6926 }
6927 void hci_simulate_working_fuzz(void){
6928     hci_init_done();
6929     hci_stack->num_cmd_packets = 255;
6930 }
6931 #endif
6932