xref: /btstack/src/hci.c (revision 0e40986336dfe5710fa510041bc2a03f87ce7589)
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 ENABLE_BLE
57 #include "gap.h"
58 #include "ble/le_device_db.h"
59 #endif
60 
61 #include <stdarg.h>
62 #include <string.h>
63 #include <inttypes.h>
64 
65 #include "btstack_debug.h"
66 #include "btstack_event.h"
67 #include "btstack_linked_list.h"
68 #include "btstack_memory.h"
69 #include "bluetooth_company_id.h"
70 #include "bluetooth_data_types.h"
71 #include "gap.h"
72 #include "hci.h"
73 #include "hci_cmd.h"
74 #include "hci_dump.h"
75 #include "ad_parser.h"
76 
77 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
78 #ifndef HCI_HOST_ACL_PACKET_NUM
79 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
80 #endif
81 #ifndef HCI_HOST_ACL_PACKET_LEN
82 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
83 #endif
84 #ifndef HCI_HOST_SCO_PACKET_NUM
85 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
86 #endif
87 #ifndef HCI_HOST_SCO_PACKET_LEN
88 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
89 #endif
90 #endif
91 
92 #if defined(ENABLE_SCO_OVER_HCI) && defined(ENABLE_SCO_OVER_PCM)
93 #error "SCO data can either be routed over HCI or over PCM, but not over both. Please only enable ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM."
94 #endif
95 
96 #if defined(ENABLE_SCO_OVER_HCI) && defined(HAVE_SCO_TRANSPORT)
97 #error "SCO data can either be routed over HCI or over PCM, but not over both. Please only enable ENABLE_SCO_OVER_HCI or HAVE_SCO_TRANSPORT."
98 #endif
99 
100 #define HCI_CONNECTION_TIMEOUT_MS 10000
101 
102 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
103 #define HCI_RESET_RESEND_TIMEOUT_MS 200
104 #endif
105 
106 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
107 #ifndef GAP_INQUIRY_MAX_NAME_LEN
108 #define GAP_INQUIRY_MAX_NAME_LEN 32
109 #endif
110 
111 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
112 #define GAP_INQUIRY_DURATION_MIN       0x01
113 #define GAP_INQUIRY_DURATION_MAX       0x30
114 #define GAP_INQUIRY_STATE_IDLE         0x00
115 #define GAP_INQUIRY_STATE_W4_ACTIVE    0x80
116 #define GAP_INQUIRY_STATE_ACTIVE       0x81
117 #define GAP_INQUIRY_STATE_W2_CANCEL    0x82
118 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x83
119 
120 // GAP Remote Name Request
121 #define GAP_REMOTE_NAME_STATE_IDLE 0
122 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
123 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
124 
125 // GAP Pairing
126 #define GAP_PAIRING_STATE_IDLE                       0
127 #define GAP_PAIRING_STATE_SEND_PIN                   1
128 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
129 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
130 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
131 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
132 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
133 #define GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE  7
134 
135 // prototypes
136 #ifdef ENABLE_CLASSIC
137 static void hci_update_scan_enable(void);
138 static void hci_emit_discoverable_enabled(uint8_t enabled);
139 static int  hci_local_ssp_activated(void);
140 static bool hci_remote_ssp_supported(hci_con_handle_t con_handle);
141 static bool hci_ssp_supported(hci_connection_t * connection);
142 static void hci_notify_if_sco_can_send_now(void);
143 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
144 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
145 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
146 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
147 static void hci_connection_timestamp(hci_connection_t *connection);
148 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
149 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
150 #endif
151 
152 static int  hci_power_control_on(void);
153 static void hci_power_control_off(void);
154 static void hci_state_reset(void);
155 static void hci_emit_transport_packet_sent(void);
156 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
157 static void hci_emit_nr_connections_changed(void);
158 static void hci_emit_hci_open_failed(void);
159 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
160 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
161 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
162 static void hci_run(void);
163 static int  hci_is_le_connection(hci_connection_t * connection);
164 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
165 
166 #ifdef ENABLE_CLASSIC
167 static int hci_have_usb_transport(void);
168 #endif
169 
170 #ifdef ENABLE_BLE
171 #ifdef ENABLE_LE_CENTRAL
172 // called from test/ble_client/advertising_data_parser.c
173 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
174 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address);
175 static hci_connection_t * gap_get_outgoing_connection(void);
176 #endif
177 #endif
178 
179 // the STACK is here
180 #ifndef HAVE_MALLOC
181 static hci_stack_t   hci_stack_static;
182 #endif
183 static hci_stack_t * hci_stack = NULL;
184 
185 #ifdef ENABLE_CLASSIC
186 // default name
187 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
188 
189 // test helper
190 static uint8_t disable_l2cap_timeouts = 0;
191 #endif
192 
193 // reset connection state on create and on reconnect
194 // don't overwrite addr, con handle, role
195 static void hci_connection_init(hci_connection_t * conn){
196     conn->authentication_flags = AUTH_FLAG_NONE;
197     conn->bonding_flags = 0;
198     conn->requested_security_level = LEVEL_0;
199 #ifdef ENABLE_CLASSIC
200     conn->request_role = HCI_ROLE_INVALID;
201     conn->sniff_subrating_max_latency = 0xffff;
202     conn->qos_service_type = HCI_SERVICE_TYPE_INVALID;
203     conn->link_key_type = INVALID_LINK_KEY;
204     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
205     btstack_run_loop_set_timer_context(&conn->timeout, conn);
206     hci_connection_timestamp(conn);
207 #endif
208     conn->acl_recombination_length = 0;
209     conn->acl_recombination_pos = 0;
210     conn->num_packets_sent = 0;
211 
212     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
213 #ifdef ENABLE_BLE
214     conn->le_phy_update_all_phys = 0xff;
215 #endif
216 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
217     conn->le_max_tx_octets = 27;
218 #endif
219 #ifdef ENABLE_CLASSIC_PAIRING_OOB
220     conn->classic_oob_c_192 = NULL;
221     conn->classic_oob_r_192 = NULL;
222     conn->classic_oob_c_256 = NULL;
223     conn->classic_oob_r_256 = NULL;
224 #endif
225 }
226 
227 /**
228  * create connection for given address
229  *
230  * @return connection OR NULL, if no memory left
231  */
232 static hci_connection_t * create_connection_for_bd_addr_and_type(const bd_addr_t addr, bd_addr_type_t addr_type){
233     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
234 
235     hci_connection_t * conn = btstack_memory_hci_connection_get();
236     if (!conn) return NULL;
237     hci_connection_init(conn);
238 
239     bd_addr_copy(conn->address, addr);
240     conn->address_type = addr_type;
241     conn->con_handle = HCI_CON_HANDLE_INVALID;
242     conn->role = HCI_ROLE_INVALID;
243 
244     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
245 
246     return conn;
247 }
248 
249 
250 /**
251  * get le connection parameter range
252 *
253  * @return le connection parameter range struct
254  */
255 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
256     *range = hci_stack->le_connection_parameter_range;
257 }
258 
259 /**
260  * set le connection parameter range
261  *
262  */
263 
264 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
265     hci_stack->le_connection_parameter_range = *range;
266 }
267 
268 /**
269  * @brief Test if connection parameters are inside in existing rage
270  * @param conn_interval_min (unit: 1.25ms)
271  * @param conn_interval_max (unit: 1.25ms)
272  * @param conn_latency
273  * @param supervision_timeout (unit: 10ms)
274  * @returns 1 if included
275  */
276 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){
277     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
278     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
279 
280     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
281     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
282 
283     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
284     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
285 
286     return 1;
287 }
288 
289 /**
290  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
291  * @note: default: 1
292  * @param max_peripheral_connections
293  */
294 #ifdef ENABLE_LE_PERIPHERAL
295 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
296     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
297 }
298 #endif
299 
300 /**
301  * get hci connections iterator
302  *
303  * @return hci connections iterator
304  */
305 
306 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
307     btstack_linked_list_iterator_init(it, &hci_stack->connections);
308 }
309 
310 /**
311  * get connection for a given handle
312  *
313  * @return connection OR NULL, if not found
314  */
315 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
316     btstack_linked_list_iterator_t it;
317     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
318     while (btstack_linked_list_iterator_has_next(&it)){
319         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
320         if ( item->con_handle == con_handle ) {
321             return item;
322         }
323     }
324     return NULL;
325 }
326 
327 /**
328  * get connection for given address
329  *
330  * @return connection OR NULL, if not found
331  */
332 hci_connection_t * hci_connection_for_bd_addr_and_type(const bd_addr_t  addr, bd_addr_type_t addr_type){
333     btstack_linked_list_iterator_t it;
334     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
335     while (btstack_linked_list_iterator_has_next(&it)){
336         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
337         if (connection->address_type != addr_type)  continue;
338         if (memcmp(addr, connection->address, 6) != 0) continue;
339         return connection;
340     }
341     return NULL;
342 }
343 
344 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
345     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
346 }
347 
348 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
349     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
350 }
351 
352 #ifdef ENABLE_CLASSIC
353 
354 #ifdef ENABLE_SCO_OVER_HCI
355 static int hci_number_sco_connections(void){
356     int connections = 0;
357     btstack_linked_list_iterator_t it;
358     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
359     while (btstack_linked_list_iterator_has_next(&it)){
360         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
361         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
362         connections++;
363     }
364     return connections;
365 }
366 #endif
367 
368 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
369     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
370 #ifdef HAVE_EMBEDDED_TICK
371     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
372         // connections might be timed out
373         hci_emit_l2cap_check_timeout(connection);
374     }
375 #else
376     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
377         // connections might be timed out
378         hci_emit_l2cap_check_timeout(connection);
379     }
380 #endif
381 }
382 
383 static void hci_connection_timestamp(hci_connection_t *connection){
384 #ifdef HAVE_EMBEDDED_TICK
385     connection->timestamp = btstack_run_loop_embedded_get_ticks();
386 #else
387     connection->timestamp = btstack_run_loop_get_time_ms();
388 #endif
389 }
390 
391 /**
392  * add authentication flags and reset timer
393  * @note: assumes classic connection
394  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
395  */
396 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
397     bd_addr_t addr;
398     reverse_bd_addr(bd_addr, addr);
399     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
400     if (conn) {
401         connectionSetAuthenticationFlags(conn, flags);
402         hci_connection_timestamp(conn);
403     }
404 }
405 
406 static bool hci_pairing_active(hci_connection_t * hci_connection){
407     return (hci_connection->authentication_flags & AUTH_FLAG_PAIRING_ACTIVE_MASK) != 0;
408 }
409 
410 static void hci_pairing_started(hci_connection_t * hci_connection, bool ssp){
411     if (hci_pairing_active(hci_connection)) return;
412     if (ssp){
413         hci_connection->authentication_flags |= AUTH_FLAG_SSP_PAIRING_ACTIVE;
414     } else {
415         hci_connection->authentication_flags |= AUTH_FLAG_LEGACY_PAIRING_ACTIVE;
416     }
417     // if we are initiator, we have sent an HCI Authenticate Request
418     bool initiator = (hci_connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0;
419 
420     // if we are responder, use minimal service security level as required level
421     if (!initiator){
422         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);
423     }
424 
425     log_info("pairing started, ssp %u, initiator %u, requested level %u", (int) ssp, (int) initiator, hci_connection->requested_security_level);
426 
427     uint8_t event[12];
428     event[0] = GAP_EVENT_PAIRING_STARTED;
429     event[1] = 10;
430     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
431     reverse_bd_addr(hci_connection->address, &event[4]);
432     event[10] = (uint8_t) ssp;
433     event[11] = (uint8_t) initiator;
434     hci_emit_event(event, sizeof(event), 1);
435 }
436 
437 static void hci_pairing_complete(hci_connection_t * hci_connection, uint8_t status){
438     hci_connection->requested_security_level = LEVEL_0;
439     if (!hci_pairing_active(hci_connection)) return;
440     hci_connection->authentication_flags &= ~AUTH_FLAG_PAIRING_ACTIVE_MASK;
441 #ifdef ENABLE_CLASSIC_PAIRING_OOB
442     hci_connection->classic_oob_c_192 = NULL;
443     hci_connection->classic_oob_r_192 = NULL;
444     hci_connection->classic_oob_c_256 = NULL;
445     hci_connection->classic_oob_r_256 = NULL;
446 #endif
447     log_info("pairing complete, status %02x", status);
448 
449     uint8_t event[12];
450     event[0] = GAP_EVENT_PAIRING_COMPLETE;
451     event[1] = 9;
452     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
453     reverse_bd_addr(hci_connection->address, &event[4]);
454     event[10] = status;
455     hci_emit_event(event, sizeof(event), 1);
456 }
457 
458 bool hci_authentication_active_for_handle(hci_con_handle_t handle){
459     hci_connection_t * conn = hci_connection_for_handle(handle);
460     if (!conn) return false;
461     return hci_pairing_active(conn);
462 }
463 
464 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
465     if (!hci_stack->link_key_db) return;
466     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
467     hci_stack->link_key_db->delete_link_key(addr);
468 }
469 
470 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
471     if (!hci_stack->link_key_db) return;
472     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
473     hci_stack->link_key_db->put_link_key(addr, link_key, type);
474 }
475 
476 bool gap_get_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t * type){
477 	if (!hci_stack->link_key_db) return false;
478 	int result = hci_stack->link_key_db->get_link_key(addr, link_key, type) != 0;
479 	log_info("link key for %s available %u, type %u", bd_addr_to_str(addr), result, (int) *type);
480 	return result;
481 }
482 
483 void gap_delete_all_link_keys(void){
484     bd_addr_t  addr;
485     link_key_t link_key;
486     link_key_type_t type;
487     btstack_link_key_iterator_t it;
488     int ok = gap_link_key_iterator_init(&it);
489     if (!ok) {
490         log_error("could not initialize iterator");
491         return;
492     }
493     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
494         gap_drop_link_key_for_bd_addr(addr);
495     }
496     gap_link_key_iterator_done(&it);
497 }
498 
499 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
500     if (!hci_stack->link_key_db) return 0;
501     if (!hci_stack->link_key_db->iterator_init) return 0;
502     return hci_stack->link_key_db->iterator_init(it);
503 }
504 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){
505     if (!hci_stack->link_key_db) return 0;
506     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
507 }
508 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
509     if (!hci_stack->link_key_db) return;
510     hci_stack->link_key_db->iterator_done(it);
511 }
512 #endif
513 
514 static bool hci_is_le_connection_type(bd_addr_type_t address_type){
515     switch (address_type){
516         case BD_ADDR_TYPE_LE_PUBLIC:
517         case BD_ADDR_TYPE_LE_RANDOM:
518         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
519         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
520             return true;
521         default:
522             return false;
523     }
524 }
525 
526 static int hci_is_le_connection(hci_connection_t * connection){
527     return hci_is_le_connection_type(connection->address_type);
528 }
529 
530 /**
531  * count connections
532  */
533 static int nr_hci_connections(void){
534     int count = 0;
535     btstack_linked_item_t *it;
536     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
537         count++;
538     }
539     return count;
540 }
541 
542 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
543 
544     unsigned int num_packets_sent_classic = 0;
545     unsigned int num_packets_sent_le = 0;
546 
547     btstack_linked_item_t *it;
548     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
549         hci_connection_t * connection = (hci_connection_t *) it;
550         if (hci_is_le_connection(connection)){
551             num_packets_sent_le += connection->num_packets_sent;
552         }
553         if (connection->address_type == BD_ADDR_TYPE_ACL){
554             num_packets_sent_classic += connection->num_packets_sent;
555         }
556     }
557     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
558     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
559     int free_slots_le = 0;
560 
561     if (free_slots_classic < 0){
562         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);
563         return 0;
564     }
565 
566     if (hci_stack->le_acl_packets_total_num){
567         // if we have LE slots, they are used
568         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
569         if (free_slots_le < 0){
570             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);
571             return 0;
572         }
573     } else {
574         // otherwise, classic slots are used for LE, too
575         free_slots_classic -= num_packets_sent_le;
576         if (free_slots_classic < 0){
577             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);
578             return 0;
579         }
580     }
581 
582     switch (address_type){
583         case BD_ADDR_TYPE_UNKNOWN:
584             log_error("hci_number_free_acl_slots: unknown address type");
585             return 0;
586 
587         case BD_ADDR_TYPE_ACL:
588             return free_slots_classic;
589 
590         default:
591            if (hci_stack->le_acl_packets_total_num){
592                return free_slots_le;
593            }
594            return free_slots_classic;
595     }
596 }
597 
598 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
599     // get connection type
600     hci_connection_t * connection = hci_connection_for_handle(con_handle);
601     if (!connection){
602         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
603         return 0;
604     }
605     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
606 }
607 
608 #ifdef ENABLE_CLASSIC
609 static int hci_number_free_sco_slots(void){
610     unsigned int num_sco_packets_sent  = 0;
611     btstack_linked_item_t *it;
612     if (hci_stack->synchronous_flow_control_enabled){
613         // explicit flow control
614         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
615             hci_connection_t * connection = (hci_connection_t *) it;
616             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
617             num_sco_packets_sent += connection->num_packets_sent;
618         }
619         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
620             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
621             return 0;
622         }
623         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
624     } else {
625         // implicit flow control -- TODO
626         int num_ready = 0;
627         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
628             hci_connection_t * connection = (hci_connection_t *) it;
629             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
630             if (connection->sco_tx_ready == 0) continue;
631             num_ready++;
632         }
633         return num_ready;
634     }
635 }
636 #endif
637 
638 // only used to send HCI Host Number Completed Packets
639 static int hci_can_send_comand_packet_transport(void){
640     if (hci_stack->hci_packet_buffer_reserved) return 0;
641 
642     // check for async hci transport implementations
643     if (hci_stack->hci_transport->can_send_packet_now){
644         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
645             return 0;
646         }
647     }
648     return 1;
649 }
650 
651 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
652 bool hci_can_send_command_packet_now(void){
653     if (hci_can_send_comand_packet_transport() == 0) return false;
654     return hci_stack->num_cmd_packets > 0u;
655 }
656 
657 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
658     // check for async hci transport implementations
659     if (!hci_stack->hci_transport->can_send_packet_now) return true;
660     return hci_stack->hci_transport->can_send_packet_now(packet_type);
661 }
662 
663 static bool hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
664     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
665     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
666 }
667 
668 bool hci_can_send_acl_le_packet_now(void){
669     if (hci_stack->hci_packet_buffer_reserved) return false;
670     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
671 }
672 
673 bool hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
674     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
675     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
676 }
677 
678 bool hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
679     if (hci_stack->hci_packet_buffer_reserved) return false;
680     return hci_can_send_prepared_acl_packet_now(con_handle);
681 }
682 
683 #ifdef ENABLE_CLASSIC
684 bool hci_can_send_acl_classic_packet_now(void){
685     if (hci_stack->hci_packet_buffer_reserved) return false;
686     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
687 }
688 
689 bool hci_can_send_prepared_sco_packet_now(void){
690     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return false;
691     if (hci_have_usb_transport()){
692         return hci_stack->sco_can_send_now;
693     } else {
694         return hci_number_free_sco_slots() > 0;
695     }
696 }
697 
698 bool hci_can_send_sco_packet_now(void){
699     if (hci_stack->hci_packet_buffer_reserved) return false;
700     return hci_can_send_prepared_sco_packet_now();
701 }
702 
703 void hci_request_sco_can_send_now_event(void){
704     hci_stack->sco_waiting_for_can_send_now = 1;
705     hci_notify_if_sco_can_send_now();
706 }
707 #endif
708 
709 // used for internal checks in l2cap.c
710 bool hci_is_packet_buffer_reserved(void){
711     return hci_stack->hci_packet_buffer_reserved;
712 }
713 
714 // reserves outgoing packet buffer. @returns 1 if successful
715 bool hci_reserve_packet_buffer(void){
716     if (hci_stack->hci_packet_buffer_reserved) {
717         log_error("hci_reserve_packet_buffer called but buffer already reserved");
718         return false;
719     }
720     hci_stack->hci_packet_buffer_reserved = true;
721     return true;
722 }
723 
724 void hci_release_packet_buffer(void){
725     hci_stack->hci_packet_buffer_reserved = false;
726 }
727 
728 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
729 static int hci_transport_synchronous(void){
730     return hci_stack->hci_transport->can_send_packet_now == NULL;
731 }
732 
733 static uint8_t hci_send_acl_packet_fragments(hci_connection_t *connection){
734 
735     // 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);
736 
737     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
738     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
739     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0u)){
740         max_acl_data_packet_length = hci_stack->le_data_packets_length;
741     }
742 
743 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
744     if (hci_is_le_connection(connection) && (connection->le_max_tx_octets < max_acl_data_packet_length)){
745         max_acl_data_packet_length = connection->le_max_tx_octets;
746     }
747 #endif
748 
749     log_debug("hci_send_acl_packet_fragments entered");
750 
751     uint8_t status = ERROR_CODE_SUCCESS;
752     // multiple packets could be send on a synchronous HCI transport
753     while (true){
754 
755         log_debug("hci_send_acl_packet_fragments loop entered");
756 
757         // get current data
758         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4u;
759         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
760         bool more_fragments = false;
761 
762         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
763         if (current_acl_data_packet_length > max_acl_data_packet_length){
764             more_fragments = true;
765             current_acl_data_packet_length = max_acl_data_packet_length;
766         }
767 
768         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
769         if (acl_header_pos > 0u){
770             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
771             handle_and_flags = (handle_and_flags & 0xcfffu) | (1u << 12u);
772             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
773         }
774 
775         // update header len
776         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2u, current_acl_data_packet_length);
777 
778         // count packet
779         connection->num_packets_sent++;
780         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", (int) more_fragments);
781 
782         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
783         if (more_fragments){
784             // update start of next fragment to send
785             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
786         } else {
787             // done
788             hci_stack->acl_fragmentation_pos = 0;
789             hci_stack->acl_fragmentation_total_size = 0;
790         }
791 
792         // send packet
793         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
794         const int size = current_acl_data_packet_length + 4;
795         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
796         hci_stack->acl_fragmentation_tx_active = 1;
797         int err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
798         if (err != 0){
799             // no error from HCI Transport expected
800             status = ERROR_CODE_HARDWARE_FAILURE;
801         }
802 
803         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", (int) more_fragments);
804 
805         // done yet?
806         if (!more_fragments) break;
807 
808         // can send more?
809         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return status;
810     }
811 
812     log_debug("hci_send_acl_packet_fragments loop over");
813 
814     // release buffer now for synchronous transport
815     if (hci_transport_synchronous()){
816         hci_stack->acl_fragmentation_tx_active = 0;
817         hci_release_packet_buffer();
818         hci_emit_transport_packet_sent();
819     }
820 
821     return status;
822 }
823 
824 // pre: caller has reserved the packet buffer
825 uint8_t hci_send_acl_packet_buffer(int size){
826     btstack_assert(hci_stack->hci_packet_buffer_reserved);
827 
828     uint8_t * packet = hci_stack->hci_packet_buffer;
829     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
830 
831     // check for free places on Bluetooth module
832     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
833         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
834         hci_release_packet_buffer();
835         hci_emit_transport_packet_sent();
836         return BTSTACK_ACL_BUFFERS_FULL;
837     }
838 
839     hci_connection_t *connection = hci_connection_for_handle( con_handle);
840     if (!connection) {
841         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
842         hci_release_packet_buffer();
843         hci_emit_transport_packet_sent();
844         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
845     }
846 
847 #ifdef ENABLE_CLASSIC
848     hci_connection_timestamp(connection);
849 #endif
850 
851     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
852 
853     // setup data
854     hci_stack->acl_fragmentation_total_size = size;
855     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
856 
857     return hci_send_acl_packet_fragments(connection);
858 }
859 
860 #ifdef ENABLE_CLASSIC
861 // pre: caller has reserved the packet buffer
862 uint8_t hci_send_sco_packet_buffer(int size){
863     btstack_assert(hci_stack->hci_packet_buffer_reserved);
864 
865     uint8_t * packet = hci_stack->hci_packet_buffer;
866 
867     // skip checks in loopback mode
868     if (!hci_stack->loopback_mode){
869         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
870 
871         // check for free places on Bluetooth module
872         if (!hci_can_send_prepared_sco_packet_now()) {
873             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
874             hci_release_packet_buffer();
875             hci_emit_transport_packet_sent();
876             return BTSTACK_ACL_BUFFERS_FULL;
877         }
878 
879         // track send packet in connection struct
880         hci_connection_t *connection = hci_connection_for_handle( con_handle);
881         if (!connection) {
882             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
883             hci_release_packet_buffer();
884             hci_emit_transport_packet_sent();
885             return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
886         }
887 
888         if (hci_have_usb_transport()){
889             // token used
890             hci_stack->sco_can_send_now = false;
891         } else {
892             if (hci_stack->synchronous_flow_control_enabled){
893                 connection->num_packets_sent++;
894             } else {
895                 connection->sco_tx_ready--;
896             }
897         }
898     }
899 
900     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
901 
902 #ifdef HAVE_SCO_TRANSPORT
903     hci_stack->sco_transport->send_packet(packet, size);
904     hci_release_packet_buffer();
905     hci_emit_transport_packet_sent();
906 
907     return 0;
908 #else
909     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
910     if (hci_transport_synchronous()){
911         hci_release_packet_buffer();
912         hci_emit_transport_packet_sent();
913     }
914 
915     if (err != 0){
916         return ERROR_CODE_HARDWARE_FAILURE;
917     }
918     return ERROR_CODE_SUCCESS;
919 #endif
920 }
921 #endif
922 
923 static void acl_handler(uint8_t *packet, uint16_t size){
924 
925     // get info
926     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
927     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
928     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
929     uint16_t acl_length         = READ_ACL_LENGTH(packet);
930 
931     // ignore non-registered handle
932     if (!conn){
933         log_error("acl_handler called with non-registered handle %u!" , con_handle);
934         return;
935     }
936 
937     // assert packet is complete
938     if ((acl_length + 4u) != size){
939         log_error("acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
940         return;
941     }
942 
943 #ifdef ENABLE_CLASSIC
944     // update idle timestamp
945     hci_connection_timestamp(conn);
946 #endif
947 
948 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
949     hci_stack->host_completed_packets = 1;
950     conn->num_packets_completed++;
951 #endif
952 
953     // handle different packet types
954     switch (acl_flags & 0x03u) {
955 
956         case 0x01: // continuation fragment
957 
958             // sanity checks
959             if (conn->acl_recombination_pos == 0u) {
960                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
961                 return;
962             }
963             if ((conn->acl_recombination_pos + acl_length) > (4u + HCI_ACL_BUFFER_SIZE)){
964                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
965                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
966                 conn->acl_recombination_pos = 0;
967                 return;
968             }
969 
970             // append fragment payload (header already stored)
971             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
972                          &packet[4], acl_length);
973             conn->acl_recombination_pos += acl_length;
974 
975             // forward complete L2CAP packet if complete.
976             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4u + 4u)){ // pos already incl. ACL header
977                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
978                 // reset recombination buffer
979                 conn->acl_recombination_length = 0;
980                 conn->acl_recombination_pos = 0;
981             }
982             break;
983 
984         case 0x02: { // first fragment
985 
986             // sanity check
987             if (conn->acl_recombination_pos) {
988                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
989                 conn->acl_recombination_pos = 0;
990             }
991 
992             // peek into L2CAP packet!
993             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
994 
995             // compare fragment size to L2CAP packet size
996             if (acl_length >= (l2cap_length + 4u)){
997                 // forward fragment as L2CAP packet
998                 hci_emit_acl_packet(packet, acl_length + 4u);
999             } else {
1000 
1001                 if (acl_length > HCI_ACL_BUFFER_SIZE){
1002                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
1003                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
1004                     return;
1005                 }
1006 
1007                 // store first fragment and tweak acl length for complete package
1008                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
1009                              packet, acl_length + 4u);
1010                 conn->acl_recombination_pos    = acl_length + 4u;
1011                 conn->acl_recombination_length = l2cap_length;
1012                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2u, l2cap_length +4u);
1013             }
1014             break;
1015 
1016         }
1017         default:
1018             log_error( "acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
1019             return;
1020     }
1021 
1022     // execute main loop
1023     hci_run();
1024 }
1025 
1026 static void hci_connection_stop_timer(hci_connection_t * conn){
1027     btstack_run_loop_remove_timer(&conn->timeout);
1028 #ifdef ENABLE_CLASSIC
1029     btstack_run_loop_remove_timer(&conn->timeout_sco);
1030 #endif
1031 }
1032 
1033 static void hci_shutdown_connection(hci_connection_t *conn){
1034     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
1035 
1036 #ifdef ENABLE_CLASSIC
1037 #if defined(ENABLE_SCO_OVER_HCI) || defined(HAVE_SCO_TRANSPORT)
1038     bd_addr_type_t addr_type = conn->address_type;
1039 #endif
1040 #ifdef HAVE_SCO_TRANSPORT
1041     hci_con_handle_t con_handle = conn->con_handle;
1042 #endif
1043 #endif
1044 
1045     hci_connection_stop_timer(conn);
1046 
1047     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1048     btstack_memory_hci_connection_free( conn );
1049 
1050     // now it's gone
1051     hci_emit_nr_connections_changed();
1052 
1053 #ifdef ENABLE_CLASSIC
1054 #ifdef ENABLE_SCO_OVER_HCI
1055     // update SCO
1056     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->hci_transport != NULL) && (hci_stack->hci_transport->set_sco_config != NULL)){
1057         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
1058     }
1059 #endif
1060 #ifdef HAVE_SCO_TRANSPORT
1061     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->sco_transport != NULL)){
1062         hci_stack->sco_transport->close(con_handle);
1063     }
1064 #endif
1065 #endif
1066 }
1067 
1068 #ifdef ENABLE_CLASSIC
1069 
1070 static const uint16_t packet_type_sizes[] = {
1071     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
1072     HCI_ACL_DH1_SIZE, 0, 0, 0,
1073     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
1074     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
1075 };
1076 static const uint8_t  packet_type_feature_requirement_bit[] = {
1077      0, // 3 slot packets
1078      1, // 5 slot packets
1079     25, // EDR 2 mpbs
1080     26, // EDR 3 mbps
1081     39, // 3 slot EDR packts
1082     40, // 5 slot EDR packet
1083 };
1084 static const uint16_t packet_type_feature_packet_mask[] = {
1085     0x0f00, // 3 slot packets
1086     0xf000, // 5 slot packets
1087     0x1102, // EDR 2 mpbs
1088     0x2204, // EDR 3 mbps
1089     0x0300, // 3 slot EDR packts
1090     0x3000, // 5 slot EDR packet
1091 };
1092 
1093 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
1094     // enable packet types based on size
1095     uint16_t packet_types = 0;
1096     unsigned int i;
1097     for (i=0;i<16;i++){
1098         if (packet_type_sizes[i] == 0) continue;
1099         if (packet_type_sizes[i] <= buffer_size){
1100             packet_types |= 1 << i;
1101         }
1102     }
1103     // disable packet types due to missing local supported features
1104     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1105         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1106         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1107         if (feature_set) continue;
1108         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1109         packet_types &= ~packet_type_feature_packet_mask[i];
1110     }
1111     // flip bits for "may not be used"
1112     packet_types ^= 0x3306;
1113     return packet_types;
1114 }
1115 
1116 uint16_t hci_usable_acl_packet_types(void){
1117     return hci_stack->packet_types;
1118 }
1119 #endif
1120 
1121 uint8_t* hci_get_outgoing_packet_buffer(void){
1122     // hci packet buffer is >= acl data packet length
1123     return hci_stack->hci_packet_buffer;
1124 }
1125 
1126 uint16_t hci_max_acl_data_packet_length(void){
1127     return hci_stack->acl_data_packet_length;
1128 }
1129 
1130 #ifdef ENABLE_CLASSIC
1131 bool hci_extended_sco_link_supported(void){
1132     // No. 31, byte 3, bit 7
1133     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1134 }
1135 #endif
1136 
1137 bool hci_non_flushable_packet_boundary_flag_supported(void){
1138     // No. 54, byte 6, bit 6
1139     return (hci_stack->local_supported_features[6u] & (1u << 6u)) != 0u;
1140 }
1141 
1142 static int gap_ssp_supported(void){
1143     // No. 51, byte 6, bit 3
1144     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1145 }
1146 
1147 static int hci_classic_supported(void){
1148 #ifdef ENABLE_CLASSIC
1149     // No. 37, byte 4, bit 5, = No BR/EDR Support
1150     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1151 #else
1152     return 0;
1153 #endif
1154 }
1155 
1156 static int hci_le_supported(void){
1157 #ifdef ENABLE_BLE
1158     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1159     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1160 #else
1161     return 0;
1162 #endif
1163 }
1164 
1165 #ifdef ENABLE_BLE
1166 
1167 static void hci_get_own_address_for_addr_type(uint8_t own_addr_type, bd_addr_t own_addr){
1168     if (own_addr_type == BD_ADDR_TYPE_LE_PUBLIC){
1169         (void)memcpy(own_addr, hci_stack->local_bd_addr, 6);
1170     } else {
1171         (void)memcpy(own_addr, hci_stack->le_random_address, 6);
1172     }
1173 }
1174 
1175 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1176     *addr_type = hci_stack->le_own_addr_type;
1177     hci_get_own_address_for_addr_type(hci_stack->le_own_addr_type, addr);
1178 }
1179 
1180 #ifdef ENABLE_LE_PERIPHERAL
1181 void gap_le_get_own_advertisements_address(uint8_t * addr_type, bd_addr_t addr){
1182     *addr_type = hci_stack->le_advertisements_own_addr_type;
1183     hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, addr);
1184 };
1185 #endif
1186 
1187 #ifdef ENABLE_LE_CENTRAL
1188 
1189 /**
1190  * @brief Get own addr type and address used for LE connections (Central)
1191  */
1192 void gap_le_get_own_connection_address(uint8_t * addr_type, bd_addr_t addr){
1193     *addr_type = hci_stack->le_connection_own_addr_type;
1194     hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, addr);
1195 }
1196 
1197 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1198 
1199     int offset = 3;
1200     int num_reports = packet[offset];
1201     offset += 1;
1202 
1203     int i;
1204     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1205     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1206     for (i=0; (i<num_reports) && (offset < size);i++){
1207         // sanity checks on data_length:
1208         uint8_t data_length = packet[offset + 8];
1209         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1210         if ((offset + 9u + data_length + 1u) > size)    return;
1211         // setup event
1212         uint8_t event_size = 10u + data_length;
1213         int pos = 0;
1214         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1215         event[pos++] = event_size;
1216         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1217         offset += 8;
1218         pos += 8;
1219         event[pos++] = packet[offset + 1 + data_length]; // rssi
1220         event[pos++] = data_length;
1221         offset++;
1222         (void)memcpy(&event[pos], &packet[offset], data_length);
1223         pos +=    data_length;
1224         offset += data_length + 1u; // rssi
1225         hci_emit_event(event, pos, 1);
1226     }
1227 }
1228 #endif
1229 #endif
1230 
1231 #ifdef ENABLE_BLE
1232 #ifdef ENABLE_LE_PERIPHERAL
1233 static void hci_update_advertisements_enabled_for_current_roles(void){
1234     if (hci_stack->le_advertisements_enabled){
1235         // get number of active le slave connections
1236         int num_slave_connections = 0;
1237         btstack_linked_list_iterator_t it;
1238         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1239         while (btstack_linked_list_iterator_has_next(&it)){
1240             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1241             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1242             if (con->state != OPEN) continue;
1243             if (con->role  != HCI_ROLE_SLAVE) continue;
1244             if (!hci_is_le_connection(con)) continue;
1245             num_slave_connections++;
1246         }
1247         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1248         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1249     } else {
1250         hci_stack->le_advertisements_enabled_for_current_roles = false;
1251     }
1252 }
1253 #endif
1254 #endif
1255 
1256 #ifdef ENABLE_CLASSIC
1257 static void gap_run_set_local_name(void){
1258     hci_reserve_packet_buffer();
1259     uint8_t * packet = hci_stack->hci_packet_buffer;
1260     // construct HCI Command and send
1261     uint16_t opcode = hci_write_local_name.opcode;
1262     hci_stack->last_cmd_opcode = opcode;
1263     packet[0] = opcode & 0xff;
1264     packet[1] = opcode >> 8;
1265     packet[2] = DEVICE_NAME_LEN;
1266     memset(&packet[3], 0, DEVICE_NAME_LEN);
1267     uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1268     uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1269     // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1270     (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1271     // expand '00:00:00:00:00:00' in name with bd_addr
1272     btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1273     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1274 }
1275 
1276 static void gap_run_set_eir_data(void){
1277     hci_reserve_packet_buffer();
1278     uint8_t * packet = hci_stack->hci_packet_buffer;
1279     // construct HCI Command in-place and send
1280     uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1281     hci_stack->last_cmd_opcode = opcode;
1282     uint16_t offset = 0;
1283     packet[offset++] = opcode & 0xff;
1284     packet[offset++] = opcode >> 8;
1285     packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1286     packet[offset++] = 0;  // FEC not required
1287     memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1288     if (hci_stack->eir_data){
1289         // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1290         ad_context_t context;
1291         for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1292             uint8_t data_type   = ad_iterator_get_data_type(&context);
1293             uint8_t size        = ad_iterator_get_data_len(&context);
1294             const uint8_t *data = ad_iterator_get_data(&context);
1295             // copy item
1296             packet[offset++] = size + 1;
1297             packet[offset++] = data_type;
1298             memcpy(&packet[offset], data, size);
1299             // update name item
1300             if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1301                 btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1302             }
1303             offset += size;
1304         }
1305     } else {
1306         uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1307         uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1308         packet[offset++] = bytes_to_copy + 1;
1309         packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1310         (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1311         // expand '00:00:00:00:00:00' in name with bd_addr
1312         btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1313     }
1314     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1315 }
1316 
1317 static void hci_run_gap_tasks_classic(void){
1318     if ((hci_stack->gap_tasks & GAP_TASK_SET_CLASS_OF_DEVICE) != 0) {
1319         hci_stack->gap_tasks &= ~GAP_TASK_SET_CLASS_OF_DEVICE;
1320         hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1321         return;
1322     }
1323     if ((hci_stack->gap_tasks & GAP_TASK_SET_LOCAL_NAME) != 0) {
1324         hci_stack->gap_tasks &= ~GAP_TASK_SET_LOCAL_NAME;
1325         gap_run_set_local_name();
1326         return;
1327     }
1328     if ((hci_stack->gap_tasks & GAP_TASK_SET_EIR_DATA) != 0) {
1329         hci_stack->gap_tasks &= ~GAP_TASK_SET_EIR_DATA;
1330         gap_run_set_eir_data();
1331         return;
1332     }
1333     if ((hci_stack->gap_tasks & GAP_TASK_SET_DEFAULT_LINK_POLICY) != 0) {
1334         hci_stack->gap_tasks &= ~GAP_TASK_SET_DEFAULT_LINK_POLICY;
1335         hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1336         return;
1337     }
1338     // write page scan activity
1339     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY) != 0) {
1340         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
1341         hci_send_cmd(&hci_write_page_scan_activity, hci_stack->new_page_scan_interval, hci_stack->new_page_scan_window);
1342         return;
1343     }
1344     // write page scan type
1345     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_TYPE) != 0) {
1346         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_TYPE;
1347         hci_send_cmd(&hci_write_page_scan_type, hci_stack->new_page_scan_type);
1348         return;
1349     }
1350     // send scan enable
1351     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_SCAN_ENABLE) != 0) {
1352         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_SCAN_ENABLE;
1353         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1354         return;
1355     }
1356 }
1357 #endif
1358 
1359 #ifndef HAVE_HOST_CONTROLLER_API
1360 
1361 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1362     if (!hci_stack->config) return 0;
1363     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1364     // Limit baud rate for Broadcom chipsets to 3 mbps
1365     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1366         baud_rate = 3000000;
1367     }
1368     return baud_rate;
1369 }
1370 
1371 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1372     UNUSED(ds);
1373 
1374     switch (hci_stack->substate){
1375         case HCI_INIT_W4_SEND_RESET:
1376             log_info("Resend HCI Reset");
1377             hci_stack->substate = HCI_INIT_SEND_RESET;
1378             hci_stack->num_cmd_packets = 1;
1379             hci_run();
1380             break;
1381         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1382             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1383             if (hci_stack->hci_transport->reset_link){
1384                 hci_stack->hci_transport->reset_link();
1385             }
1386 
1387             /* fall through */
1388 
1389         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1390             log_info("Resend HCI Reset - CSR Warm Boot");
1391             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1392             hci_stack->num_cmd_packets = 1;
1393             hci_run();
1394             break;
1395         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1396             if (hci_stack->hci_transport->set_baudrate){
1397                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1398                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1399                 hci_stack->hci_transport->set_baudrate(baud_rate);
1400             }
1401             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1402             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1403                 if (hci_stack->hci_transport->reset_link){
1404                     log_info("Link Reset");
1405                     hci_stack->hci_transport->reset_link();
1406                 }
1407                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1408                 hci_run();
1409             }
1410             break;
1411         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1412             // otherwise continue
1413             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1414             hci_send_cmd(&hci_read_local_supported_commands);
1415             break;
1416         default:
1417             break;
1418     }
1419 }
1420 #endif
1421 
1422 static void hci_initializing_next_state(void){
1423     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1424 }
1425 
1426 static void hci_init_done(void){
1427     // done. tell the app
1428     log_info("hci_init_done -> HCI_STATE_WORKING");
1429     hci_stack->state = HCI_STATE_WORKING;
1430     hci_emit_state();
1431 }
1432 
1433 // assumption: hci_can_send_command_packet_now() == true
1434 static void hci_initializing_run(void){
1435     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1436 
1437 #ifndef HAVE_HOST_CONTROLLER_API
1438     bool need_baud_change = hci_stack->config
1439             && hci_stack->chipset
1440             && hci_stack->chipset->set_baudrate_command
1441             && hci_stack->hci_transport->set_baudrate
1442             && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1443 #endif
1444 
1445     switch (hci_stack->substate){
1446         case HCI_INIT_SEND_RESET:
1447             hci_state_reset();
1448 
1449 #ifndef HAVE_HOST_CONTROLLER_API
1450             // prepare reset if command complete not received in 100ms
1451             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1452             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1453             btstack_run_loop_add_timer(&hci_stack->timeout);
1454 #endif
1455             // send command
1456             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1457             hci_send_cmd(&hci_reset);
1458             break;
1459         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1460             hci_send_cmd(&hci_read_local_version_information);
1461             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1462             break;
1463 
1464 #ifndef HAVE_HOST_CONTROLLER_API
1465         case HCI_INIT_SEND_READ_LOCAL_NAME:
1466             hci_send_cmd(&hci_read_local_name);
1467             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1468             break;
1469         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1470             hci_state_reset();
1471             // prepare reset if command complete not received in 100ms
1472             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1473             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1474             btstack_run_loop_add_timer(&hci_stack->timeout);
1475             // send command
1476             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1477             hci_send_cmd(&hci_reset);
1478             break;
1479         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1480             hci_state_reset();
1481             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1482             hci_send_cmd(&hci_reset);
1483             break;
1484         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1485             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1486             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1487             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1488             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1489             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1490             break;
1491         }
1492         case HCI_INIT_SET_BD_ADDR:
1493             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1494             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1495             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1496             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1497             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1498             break;
1499         case HCI_INIT_SEND_BAUD_CHANGE:
1500             if (need_baud_change) {
1501                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1502                 hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1503                 hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1504                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1505                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1506                 // STLC25000D: baudrate change happens within 0.5 s after command was send,
1507                 // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1508                 if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1509                     btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1510                     btstack_run_loop_add_timer(&hci_stack->timeout);
1511                }
1512                break;
1513             }
1514 
1515             /* fall through */
1516 
1517         case HCI_INIT_CUSTOM_INIT:
1518             // Custom initialization
1519             if (hci_stack->chipset && hci_stack->chipset->next_command){
1520                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1521                 bool send_cmd = false;
1522                 switch (hci_stack->chipset_result){
1523                     case BTSTACK_CHIPSET_VALID_COMMAND:
1524                         send_cmd = true;
1525                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1526                         break;
1527                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1528                         send_cmd = true;
1529                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1530                         log_info("CSR Warm Boot");
1531                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1532                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1533                         btstack_run_loop_add_timer(&hci_stack->timeout);
1534                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1535                             && hci_stack->config
1536                             && hci_stack->chipset
1537                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1538                             && hci_stack->hci_transport->set_baudrate
1539                             && hci_transport_uart_get_main_baud_rate()){
1540                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1541                         } else {
1542                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1543                         }
1544                         break;
1545                     default:
1546                         break;
1547                 }
1548 
1549                 if (send_cmd){
1550                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1551                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1552                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1553                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1554                     break;
1555                 }
1556                 log_info("Init script done");
1557 
1558                 // Init script download on Broadcom chipsets causes:
1559                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1560                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1561                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1562 
1563                     // - baud rate to reset, restore UART baud rate if needed
1564                     if (need_baud_change) {
1565                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1566                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1567                         hci_stack->hci_transport->set_baudrate(baud_rate);
1568                     }
1569 
1570                     uint16_t bcm_delay_ms = 300;
1571                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1572                     //   -> Work around: wait here.
1573                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1574                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1575                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1576                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1577                     btstack_run_loop_add_timer(&hci_stack->timeout);
1578                     break;
1579                 }
1580             }
1581             /* fall through */
1582 #endif
1583 
1584         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1585             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1586             hci_send_cmd(&hci_read_local_supported_commands);
1587             break;
1588         case HCI_INIT_READ_BD_ADDR:
1589             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1590             hci_send_cmd(&hci_read_bd_addr);
1591             break;
1592         case HCI_INIT_READ_BUFFER_SIZE:
1593             // only read buffer size if supported
1594             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1595                 hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1596                 hci_send_cmd(&hci_read_buffer_size);
1597                 break;
1598             }
1599             /* fall through */
1600 
1601         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1602             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1603             hci_send_cmd(&hci_read_local_supported_features);
1604             break;
1605 
1606 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1607         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1608             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1609             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1610             break;
1611         case HCI_INIT_HOST_BUFFER_SIZE:
1612             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1613             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1614                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1615             break;
1616 #endif
1617 
1618         case HCI_INIT_SET_EVENT_MASK:
1619             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1620             if (hci_le_supported()){
1621                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x3FFFFFFFU);
1622             } else {
1623                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1624                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x1FFFFFFFU);
1625             }
1626             break;
1627 
1628 #ifdef ENABLE_CLASSIC
1629         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1630             if (hci_classic_supported() && gap_ssp_supported()){
1631                 hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1632                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1633                 break;
1634             }
1635             /* fall through */
1636 
1637         case HCI_INIT_WRITE_INQUIRY_MODE:
1638             if (hci_classic_supported()){
1639                 hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1640                 hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1641                 break;
1642             }
1643             /* fall through */
1644 
1645         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1646             // skip write secure connections host support if not supported or disabled
1647             if (hci_classic_supported() && hci_stack->secure_connections_enable && (hci_stack->local_supported_commands[1u] & 0x02u) != 0u) {
1648                 hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1649                 hci_stack->secure_connections_active = true;
1650                 hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1651                 break;
1652             }
1653             /* fall through */
1654 
1655         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1656             if (hci_classic_supported()){
1657                 hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1658                 hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1659                 break;
1660             }
1661             /* fall through */
1662 
1663 #ifdef ENABLE_SCO_OVER_HCI
1664         // only sent if ENABLE_SCO_OVER_HCI is defined
1665         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1666             // skip write synchronous flow control if not supported
1667             if (hci_classic_supported() && ((hci_stack->local_supported_commands[0] & 0x04) != 0)){
1668                 hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1669                 hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1670                 break;
1671             }
1672             /* fall through */
1673 
1674         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1675             // skip write default erroneous data reporting if not supported
1676             if (hci_classic_supported() && ((hci_stack->local_supported_commands[0] & 0x08) != 0)){
1677                 hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1678                 hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1679                 break;
1680             }
1681             /* fall through */
1682 #endif
1683 
1684 #if defined(ENABLE_SCO_OVER_HCI) || defined(ENABLE_SCO_OVER_PCM)
1685         // only sent if manufacturer is Broadcom and ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM is defined
1686         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1687             if (hci_classic_supported() && (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)){
1688                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1689 #ifdef ENABLE_SCO_OVER_HCI
1690                 log_info("BCM: Route SCO data via HCI transport");
1691                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1692 #endif
1693 #ifdef ENABLE_SCO_OVER_PCM
1694                 log_info("BCM: Route SCO data via PCM interface");
1695 #ifdef ENABLE_BCM_PCM_WBS
1696                 // 512 kHz bit clock for 2 channels x 16 bit x 16 kHz
1697                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 2, 0, 1, 1);
1698 #else
1699                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1700                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 1, 0, 1, 1);
1701 #endif
1702 #endif
1703                 break;
1704             }
1705             /* fall through */
1706 #endif
1707 
1708 #ifdef ENABLE_SCO_OVER_PCM
1709         case HCI_INIT_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
1710             if (hci_classic_supported() && (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)){
1711                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1712                 log_info("BCM: Config PCM interface for I2S");
1713 #ifdef ENABLE_BCM_PCM_WBS
1714                 // 512 kHz bit clock for 2 channels x 16 bit x 8 kHz
1715                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 2);
1716 #else
1717                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1718                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 1);
1719 #endif
1720                 break;
1721             }
1722             /* fall through */
1723 #endif
1724 #endif
1725 
1726 #ifdef ENABLE_BLE
1727         // LE INIT
1728         case HCI_INIT_LE_READ_BUFFER_SIZE:
1729             if (hci_le_supported()){
1730                 hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1731                 hci_send_cmd(&hci_le_read_buffer_size);
1732                 break;
1733             }
1734             /* fall through */
1735 
1736         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1737             // skip write le host if not supported (e.g. on LE only EM9301)
1738             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x02u) != 0)){
1739                 // LE Supported Host = 1, Simultaneous Host = 0
1740                 hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1741                 hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1742                 break;
1743             }
1744             /* fall through */
1745 
1746         case HCI_INIT_LE_SET_EVENT_MASK:
1747             if (hci_le_supported()){
1748                 hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1749                 hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1750                 break;
1751             }
1752             /* fall through */
1753 
1754 #endif
1755 
1756 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1757         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1758             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u)){
1759                 hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1760                 hci_send_cmd(&hci_le_read_maximum_data_length);
1761                 break;
1762             }
1763             /* fall through */
1764 
1765         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1766             if (hci_le_supported() && ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u)){
1767                 hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1768                 hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1769                 break;
1770             }
1771             /* fall through */
1772 #endif
1773 
1774 #ifdef ENABLE_LE_CENTRAL
1775         case HCI_INIT_READ_WHITE_LIST_SIZE:
1776             if (hci_le_supported()){
1777                 hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1778                 hci_send_cmd(&hci_le_read_white_list_size);
1779                 break;
1780             }
1781             /* fall through */
1782 
1783         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1784             if (hci_le_supported()){
1785                 hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1786                 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);
1787                 break;
1788             }
1789             /* fall through */
1790 #endif
1791 
1792         case HCI_INIT_DONE:
1793             hci_stack->substate = HCI_INIT_DONE;
1794 #ifdef ENABLE_CLASSIC
1795             // init sequence complete, check if GAP Tasks are completed
1796             if (hci_stack->gap_tasks != 0) {
1797                 hci_run_gap_tasks_classic();
1798                 break;
1799             }
1800 #endif
1801             hci_init_done();
1802             break;
1803 
1804         default:
1805             return;
1806     }
1807 }
1808 
1809 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1810     bool command_completed = false;
1811     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1812         uint16_t opcode = little_endian_read_16(packet,3);
1813         if (opcode == hci_stack->last_cmd_opcode){
1814             command_completed = true;
1815             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1816         } else {
1817             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1818         }
1819     }
1820 
1821     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1822         uint8_t  status = packet[2];
1823         uint16_t opcode = little_endian_read_16(packet,4);
1824         if (opcode == hci_stack->last_cmd_opcode){
1825             if (status){
1826                 command_completed = true;
1827                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1828             } else {
1829                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1830             }
1831         } else {
1832             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1833         }
1834     }
1835 #ifndef HAVE_HOST_CONTROLLER_API
1836     // Vendor == CSR
1837     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1838         // TODO: track actual command
1839         command_completed = true;
1840     }
1841 
1842     // Vendor == Toshiba
1843     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1844         // TODO: track actual command
1845         command_completed = true;
1846         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1847         hci_stack->num_cmd_packets = 1;
1848     }
1849 #endif
1850 
1851     return command_completed;
1852 }
1853 
1854 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1855 
1856     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1857 
1858     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1859 
1860 #ifndef HAVE_HOST_CONTROLLER_API
1861 
1862     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1863     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1864     //
1865     // HCI Reset
1866     // Timeout 100 ms
1867     // HCI Reset
1868     // Command Complete Reset
1869     // HCI Read Local Version Information
1870     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1871     // hang...
1872     //
1873     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1874     if (!command_completed
1875             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1876             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1877 
1878         uint16_t opcode = little_endian_read_16(packet,3);
1879         if (opcode == hci_reset.opcode){
1880             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1881             return;
1882         }
1883     }
1884 
1885     // CSR & H5
1886     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1887     if (!command_completed
1888             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1889             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1890 
1891         uint16_t opcode = little_endian_read_16(packet,3);
1892         if (opcode == hci_reset.opcode){
1893             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1894             return;
1895         }
1896     }
1897 
1898     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1899     // fix: Correct substate and behave as command below
1900     if (command_completed){
1901         switch (hci_stack->substate){
1902             case HCI_INIT_SEND_RESET:
1903                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1904                 break;
1905             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1906                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1907                 break;
1908             default:
1909                 break;
1910         }
1911     }
1912 
1913 #endif
1914 
1915     if (!command_completed) return;
1916 
1917     bool need_baud_change = false;
1918     bool need_addr_change = false;
1919 
1920 #ifndef HAVE_HOST_CONTROLLER_API
1921     need_baud_change = hci_stack->config
1922                         && hci_stack->chipset
1923                         && hci_stack->chipset->set_baudrate_command
1924                         && hci_stack->hci_transport->set_baudrate
1925                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1926 
1927     need_addr_change = hci_stack->custom_bd_addr_set
1928                         && hci_stack->chipset
1929                         && hci_stack->chipset->set_bd_addr_command;
1930 #endif
1931 
1932     switch(hci_stack->substate){
1933 
1934 #ifndef HAVE_HOST_CONTROLLER_API
1935         case HCI_INIT_SEND_RESET:
1936             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1937             // fix: just correct substate and behave as command below
1938 
1939             /* fall through */
1940 #endif
1941 
1942         case HCI_INIT_W4_SEND_RESET:
1943             btstack_run_loop_remove_timer(&hci_stack->timeout);
1944             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1945             return;
1946 
1947 #ifndef HAVE_HOST_CONTROLLER_API
1948         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1949             // for STLC2500D, baud rate change already happened.
1950             // for others, baud rate gets changed now
1951             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1952                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1953                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1954                 hci_stack->hci_transport->set_baudrate(baud_rate);
1955             }
1956             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1957             return;
1958         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1959             btstack_run_loop_remove_timer(&hci_stack->timeout);
1960             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1961             return;
1962         case HCI_INIT_W4_CUSTOM_INIT:
1963             // repeat custom init
1964             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1965             return;
1966 #endif
1967 
1968         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1969             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1970               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1971                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1972                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1973                 return;
1974             }
1975             if (need_addr_change){
1976                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1977                 return;
1978             }
1979             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1980             return;
1981 #ifndef HAVE_HOST_CONTROLLER_API
1982         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1983             if (need_baud_change){
1984                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1985                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
1986                 hci_stack->hci_transport->set_baudrate(baud_rate);
1987             }
1988             if (need_addr_change){
1989                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1990                 return;
1991             }
1992             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1993             return;
1994         case HCI_INIT_W4_SET_BD_ADDR:
1995             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1996             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1997             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1998                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1999                 return;
2000             }
2001             // skipping st warm boot
2002             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2003             return;
2004         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
2005             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2006             return;
2007 #endif
2008 
2009         case HCI_INIT_DONE:
2010             // set state if we came here by fall through
2011             hci_stack->substate = HCI_INIT_DONE;
2012             return;
2013 
2014         default:
2015             break;
2016     }
2017     hci_initializing_next_state();
2018 }
2019 
2020 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
2021     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
2022     bd_addr_t bd_address;
2023     (void)memcpy(&bd_address, conn->address, 6);
2024 
2025 #ifdef ENABLE_CLASSIC
2026     // cache needed data
2027     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
2028 #endif
2029 
2030     // connection failed, remove entry
2031     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2032     btstack_memory_hci_connection_free( conn );
2033 
2034 #ifdef ENABLE_CLASSIC
2035     // notify client if dedicated bonding
2036     if (notify_dedicated_bonding_failed){
2037         log_info("hci notify_dedicated_bonding_failed");
2038         hci_emit_dedicated_bonding_result(bd_address, status);
2039     }
2040 
2041     // if authentication error, also delete link key
2042     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
2043         gap_drop_link_key_for_bd_addr(bd_address);
2044     }
2045 #else
2046     UNUSED(status);
2047 #endif
2048 }
2049 
2050 #ifdef ENABLE_CLASSIC
2051 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
2052     // SSP Controller
2053     if (features[6] & (1 << 3)){
2054         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
2055     }
2056     // eSCO
2057     if (features[3] & (1<<7)){
2058         conn->remote_supported_features[0] |= 1;
2059     }
2060     // Extended features
2061     if (features[7] & (1<<7)){
2062         conn->remote_supported_features[0] |= 2;
2063     }
2064 }
2065 
2066 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
2067     // SSP Host
2068     if (features[0] & (1 << 0)){
2069         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
2070     }
2071     // SC Host
2072     if (features[0] & (1 << 3)){
2073         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
2074     }
2075 }
2076 
2077 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
2078     // SC Controller
2079     if (features[1] & (1 << 0)){
2080         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2081     }
2082 }
2083 
2084 static void hci_handle_remote_features_received(hci_connection_t * conn){
2085     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
2086     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
2087     if (conn->bonding_flags & BONDING_DEDICATED){
2088         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2089     }
2090 }
2091 static bool hci_remote_sc_enabled(hci_connection_t * connection){
2092     const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2093     return (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
2094 }
2095 
2096 #endif
2097 
2098 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
2099     // handle BT initialization
2100     if (hci_stack->state == HCI_STATE_INITIALIZING) {
2101         hci_initializing_event_handler(packet, size);
2102     }
2103 
2104     // help with BT sleep
2105     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
2106         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
2107         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
2108         hci_initializing_next_state();
2109     }
2110 }
2111 
2112 #ifdef ENABLE_CLASSIC
2113 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
2114     conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2115     conn->encryption_key_size = encryption_key_size;
2116 
2117     if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) != 0) {
2118         conn->requested_security_level = LEVEL_0;
2119         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
2120         return;
2121     }
2122 
2123     // Request remote features if not already done
2124     if ((conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) == 0) {
2125         conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2126     }
2127 
2128     // Request Authentication if not already done
2129     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
2130     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2131 }
2132 #endif
2133 
2134 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
2135     UNUSED(size);
2136 
2137     uint16_t manufacturer;
2138 #ifdef ENABLE_CLASSIC
2139     hci_con_handle_t handle;
2140     hci_connection_t * conn;
2141     uint8_t status;
2142 #endif
2143     // get num cmd packets - limit to 1 to reduce complexity
2144     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2145 
2146     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
2147     switch (opcode){
2148         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
2149             if (packet[5]) break;
2150             // terminate, name 248 chars
2151             packet[6+248] = 0;
2152             log_info("local name: %s", &packet[6]);
2153             break;
2154         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2155             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2156             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2157                 uint16_t acl_len = little_endian_read_16(packet, 6);
2158                 uint16_t sco_len = packet[8];
2159 
2160                 // determine usable ACL/SCO payload size
2161                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2162                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2163 
2164                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2165                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2166 
2167                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2168                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2169                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2170             }
2171             break;
2172         case HCI_OPCODE_HCI_READ_RSSI:
2173             if (packet[5] == ERROR_CODE_SUCCESS){
2174                 uint8_t event[5];
2175                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2176                 event[1] = 3;
2177                 (void)memcpy(&event[2], &packet[6], 3);
2178                 hci_emit_event(event, sizeof(event), 1);
2179             }
2180             break;
2181 #ifdef ENABLE_BLE
2182         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2183             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2184             hci_stack->le_acl_packets_total_num = packet[8];
2185             // determine usable ACL payload size
2186             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2187                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2188             }
2189             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2190             break;
2191 #endif
2192 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2193         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2194             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2195             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2196             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);
2197             break;
2198 #endif
2199 #ifdef ENABLE_LE_CENTRAL
2200         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2201             hci_stack->le_whitelist_capacity = packet[6];
2202             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2203             break;
2204 #endif
2205         case HCI_OPCODE_HCI_READ_BD_ADDR:
2206             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2207             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));
2208 #ifdef ENABLE_CLASSIC
2209             if (hci_stack->link_key_db){
2210                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2211             }
2212 #endif
2213             break;
2214 #ifdef ENABLE_CLASSIC
2215         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2216             hci_emit_discoverable_enabled(hci_stack->discoverable);
2217             break;
2218         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2219             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2220                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2221                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2222                 hci_emit_event(event, sizeof(event), 1);
2223             }
2224             break;
2225 #endif
2226         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2227             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2228 
2229 #ifdef ENABLE_CLASSIC
2230             // determine usable ACL packet types based on host buffer size and supported features
2231             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2232             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2233 #endif
2234             // Classic/LE
2235             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2236             break;
2237         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2238             manufacturer = little_endian_read_16(packet, 10);
2239             // map Cypress to Broadcom
2240             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2241                 log_info("Treat Cypress as Broadcom");
2242                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2243                 little_endian_store_16(packet, 10, manufacturer);
2244             }
2245             hci_stack->manufacturer = manufacturer;
2246             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2247             break;
2248         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2249             hci_stack->local_supported_commands[0] =
2250                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit  0 = Octet 14, bit 7 / Read Buffer Size
2251                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit  1 = Octet 24, bit 6 / Write Le Host Supported
2252                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit  2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2253                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     )  |  // bit  3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2254                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit  4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2255                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit  5 = Octet 35, bit 3 / LE Read Maximum Data Length
2256                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit  6 = Octet 35, bit 5 / LE Set Default PHY
2257                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit  7 = Octet 20, bit 4 / Read Encryption Key Size
2258             hci_stack->local_supported_commands[1] =
2259                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit  8 = Octet  2, bit 6 / Read Remote Extended Features
2260                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u) |  // bit  9 = Octet 32, bit 3 / Write Secure Connections Host
2261                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x02u) << 1u) |  // bit 10 = Octet 35, bit 1 / LE Set Address Resolution Enable
2262                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x02u) << 2u) |  // bit 11 = Octet 32, bit 1 / Remote OOB Extended Data Request Reply
2263                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x40u) >> 2u);   // bit 12 = Octet 32, bit 6 / Read Local OOB Extended Data command
2264             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2265             break;
2266 #ifdef ENABLE_CLASSIC
2267         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2268             if (packet[5]) return;
2269             hci_stack->synchronous_flow_control_enabled = 1;
2270             break;
2271         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2272             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2273             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2274             conn   = hci_connection_for_handle(handle);
2275             if (conn != NULL) {
2276                 uint8_t key_size = 0;
2277                 if (status == 0){
2278                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2279                     log_info("Handle %04x key Size: %u", handle, key_size);
2280                 } else {
2281                     key_size = 1;
2282                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2283                 }
2284                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2285             }
2286             break;
2287         // assert pairing complete event is emitted.
2288         // note: for SSP, Simple Pairing Complete Event is sufficient, but we want to be more robust
2289         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
2290         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
2291         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
2292             hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
2293             // lookup connection by gap pairing addr
2294             conn = hci_connection_for_bd_addr_and_type(hci_stack->gap_pairing_addr, BD_ADDR_TYPE_ACL);
2295             if (conn == NULL) break;
2296             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2297             break;
2298 
2299 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2300         case HCI_OPCODE_HCI_READ_LOCAL_OOB_DATA:
2301         case HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA:{
2302             uint8_t event[67];
2303             event[0] = GAP_EVENT_LOCAL_OOB_DATA;
2304             event[1] = 65;
2305             (void)memset(&event[2], 0, 65);
2306             if (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE] == ERROR_CODE_SUCCESS){
2307                 (void)memcpy(&event[3], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 32);
2308                 if (opcode == HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA){
2309                     event[2] = 3;
2310                     (void)memcpy(&event[35], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+33], 32);
2311                 } else {
2312                     event[2] = 1;
2313                 }
2314             }
2315             hci_emit_event(event, sizeof(event), 0);
2316             break;
2317         }
2318 
2319         // note: only needed if user does not provide OOB data
2320         case HCI_OPCODE_HCI_REMOTE_OOB_DATA_REQUEST_NEGATIVE_REPLY:
2321             conn = hci_connection_for_handle(hci_stack->classic_oob_con_handle);
2322             hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
2323             if (conn == NULL) break;
2324             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2325             break;
2326 #endif
2327 #endif
2328         default:
2329             break;
2330     }
2331 }
2332 
2333 #ifdef ENABLE_BLE
2334 static void event_handle_le_connection_complete(const uint8_t * packet){
2335 	bd_addr_t addr;
2336 	bd_addr_type_t addr_type;
2337 	hci_connection_t * conn;
2338 
2339 	// Connection management
2340 	reverse_bd_addr(&packet[8], addr);
2341 	addr_type = (bd_addr_type_t)packet[7];
2342 	log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2343 	conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2344 
2345 #ifdef ENABLE_LE_CENTRAL
2346 	// handle error: error is reported only to the initiator -> outgoing connection
2347 	if (packet[3]){
2348 
2349 		// handle cancelled outgoing connection
2350 		// "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2351 		//  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2352 		//  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2353 		if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2354 		    // reset state
2355             hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2356             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2357 			// get outgoing connection conn struct for direct connect
2358 			conn = gap_get_outgoing_connection();
2359 		}
2360 
2361 		// outgoing le connection establishment is done
2362 		if (conn){
2363 			// remove entry
2364 			btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2365 			btstack_memory_hci_connection_free( conn );
2366 		}
2367 		return;
2368 	}
2369 #endif
2370 
2371 	// on success, both hosts receive connection complete event
2372 	if (packet[6] == HCI_ROLE_MASTER){
2373 #ifdef ENABLE_LE_CENTRAL
2374 		// if we're master on an le connection, it was an outgoing connection and we're done with it
2375 		// note: no hci_connection_t object exists yet for connect with whitelist
2376 		if (hci_is_le_connection_type(addr_type)){
2377 			hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2378 			hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2379 		}
2380 #endif
2381 	} else {
2382 #ifdef ENABLE_LE_PERIPHERAL
2383 		// if we're slave, it was an incoming connection, advertisements have stopped
2384 		hci_stack->le_advertisements_active = false;
2385 #endif
2386 	}
2387 
2388 	// LE connections are auto-accepted, so just create a connection if there isn't one already
2389 	if (!conn){
2390 		conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2391 	}
2392 
2393 	// no memory, sorry.
2394 	if (!conn){
2395 		return;
2396 	}
2397 
2398 	conn->state = OPEN;
2399 	conn->role  = packet[6];
2400 	conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2401 	conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2402 
2403 #ifdef ENABLE_LE_PERIPHERAL
2404 	if (packet[6] == HCI_ROLE_SLAVE){
2405 		hci_update_advertisements_enabled_for_current_roles();
2406 	}
2407 #endif
2408 
2409     // init unenhanced att bearer mtu
2410     conn->att_connection.mtu = ATT_DEFAULT_MTU;
2411     conn->att_connection.mtu_exchanged = false;
2412 
2413     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2414 
2415 	// restart timer
2416 	// btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2417 	// btstack_run_loop_add_timer(&conn->timeout);
2418 
2419 	log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2420 
2421 	hci_emit_nr_connections_changed();
2422 }
2423 #endif
2424 
2425 #ifdef ENABLE_CLASSIC
2426 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){
2427     if (io_cap_local == SSP_IO_CAPABILITY_UNKNOWN) return false;
2428     // LEVEL_4 is tested by l2cap
2429     // LEVEL 3 requires MITM protection -> check io capabilities if Authenticated is possible
2430     // @see: Core Spec v5.3, Vol 3, Part C, Table 5.7
2431     if (level >= LEVEL_3){
2432         // MITM not possible without keyboard or display
2433         if (io_cap_remote >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2434         if (io_cap_local  >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2435 
2436         // MITM possible if one side has keyboard and the other has keyboard or display
2437         if (io_cap_remote == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2438         if (io_cap_local  == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2439 
2440         // MITM not possible if one side has only display and other side has no keyboard
2441         if (io_cap_remote == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2442         if (io_cap_local  == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2443     }
2444     // LEVEL 2 requires SSP, which is a given
2445     return true;
2446 }
2447 
2448 static bool btstack_is_null(uint8_t * data, uint16_t size){
2449     uint16_t i;
2450     for (i=0; i < size ; i++){
2451         if (data[i] != 0) {
2452             return false;
2453         }
2454     }
2455     return true;
2456 }
2457 
2458 static void hci_ssp_assess_security_on_io_cap_request(hci_connection_t * conn){
2459     // get requested security level
2460     gap_security_level_t requested_security_level = conn->requested_security_level;
2461     if (hci_stack->gap_secure_connections_only_mode){
2462         requested_security_level = LEVEL_4;
2463     }
2464 
2465     // assess security: LEVEL 4 requires SC
2466     // skip this preliminary test if remote features are not available yet to work around potential issue in ESP32 controller
2467     if ((requested_security_level == LEVEL_4) &&
2468         ((conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0) &&
2469         !hci_remote_sc_enabled(conn)){
2470         log_info("Level 4 required, but SC not supported -> abort");
2471         hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2472         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2473         return;
2474     }
2475 
2476     // assess security based on io capabilities
2477     if (conn->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
2478         // responder: fully validate io caps of both sides as well as OOB data
2479         bool security_possible = false;
2480         security_possible = hci_ssp_security_level_possible_for_io_cap(requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io);
2481 
2482 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2483         // We assume that both Controller can reach LEVEL 4, if one side has received P-192 and the other has received P-256,
2484         // so we merge the OOB data availability
2485         uint8_t have_oob_data = conn->io_cap_response_oob_data;
2486         if (conn->classic_oob_c_192 != NULL){
2487             have_oob_data |= 1;
2488         }
2489         if (conn->classic_oob_c_256 != NULL){
2490             have_oob_data |= 2;
2491         }
2492         // for up to Level 3, either P-192 as well as P-256 will do
2493         // 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
2494         // if remote does not SC, we should not receive P-256 data either
2495         if ((requested_security_level <= LEVEL_3) && (have_oob_data != 0)){
2496             security_possible = true;
2497         }
2498         // for Level 4, P-256 is needed
2499         if ((requested_security_level == LEVEL_4 && ((have_oob_data & 2) != 0))){
2500             security_possible = true;
2501         }
2502 #endif
2503 
2504         if (security_possible == false){
2505             log_info("IOCap/OOB insufficient for level %u -> abort", requested_security_level);
2506             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2507             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2508             return;
2509         }
2510     } else {
2511         // initiator: remote io cap not yet, only check if we have ability for MITM protection if requested and OOB is not supported
2512 #ifndef ENABLE_CLASSIC_PAIRING_OOB
2513 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2514         if ((conn->requested_security_level >= LEVEL_3) && (hci_stack->ssp_io_capability >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT)){
2515             log_info("Level 3+ required, but no input/output -> abort");
2516             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2517             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2518             return;
2519         }
2520 #endif
2521 #endif
2522     }
2523 
2524 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2525     if (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN){
2526         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
2527     } else {
2528         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2529     }
2530 #endif
2531 }
2532 
2533 #endif
2534 
2535 static void event_handler(uint8_t *packet, uint16_t size){
2536 
2537     uint16_t event_length = packet[1];
2538 
2539     // assert packet is complete
2540     if (size != (event_length + 2u)){
2541         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2542         return;
2543     }
2544 
2545     bd_addr_type_t addr_type;
2546     hci_con_handle_t handle;
2547     hci_connection_t * conn;
2548     int i;
2549     int create_connection_cmd;
2550 
2551 #ifdef ENABLE_CLASSIC
2552     hci_link_type_t link_type;
2553     bd_addr_t addr;
2554 #endif
2555 
2556     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2557 
2558     switch (hci_event_packet_get_type(packet)) {
2559 
2560         case HCI_EVENT_COMMAND_COMPLETE:
2561             handle_command_complete_event(packet, size);
2562             break;
2563 
2564         case HCI_EVENT_COMMAND_STATUS:
2565             // get num cmd packets - limit to 1 to reduce complexity
2566             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2567 
2568             // check command status to detected failed outgoing connections
2569             create_connection_cmd = 0;
2570 #ifdef ENABLE_CLASSIC
2571             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2572                 create_connection_cmd = 1;
2573             }
2574 #endif
2575 #ifdef ENABLE_LE_CENTRAL
2576             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2577                 create_connection_cmd = 1;
2578             }
2579 #endif
2580             if (create_connection_cmd) {
2581                 uint8_t status = hci_event_command_status_get_status(packet);
2582                 addr_type = hci_stack->outgoing_addr_type;
2583                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, addr_type);
2584                 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);
2585 
2586                 // reset outgoing address info
2587                 memset(hci_stack->outgoing_addr, 0, 6);
2588                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2589 
2590                 // on error
2591                 if (status != ERROR_CODE_SUCCESS){
2592 #ifdef ENABLE_LE_CENTRAL
2593                     if (hci_is_le_connection_type(addr_type)){
2594                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2595                         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2596                     }
2597 #endif
2598                     // error => outgoing connection failed
2599                     if (conn != NULL){
2600                         hci_handle_connection_failed(conn, status);
2601                     }
2602                 }
2603             }
2604 
2605 #ifdef ENABLE_CLASSIC
2606             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_inquiry)) {
2607                 uint8_t status = hci_event_command_status_get_status(packet);
2608                 log_info("command status (inquiry), status %x", status);
2609                 if (status == ERROR_CODE_SUCCESS) {
2610                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
2611                 } else {
2612                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2613                 }
2614             }
2615 #endif
2616             break;
2617 
2618         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2619             if (size < 3) return;
2620             uint16_t num_handles = packet[2];
2621             if (size != (3u + num_handles * 4u)) return;
2622             uint16_t offset = 3;
2623             for (i=0; i<num_handles;i++){
2624                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2625                 offset += 2u;
2626                 uint16_t num_packets = little_endian_read_16(packet, offset);
2627                 offset += 2u;
2628 
2629                 conn = hci_connection_for_handle(handle);
2630                 if (!conn){
2631                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2632                     continue;
2633                 }
2634 
2635                 if (conn->num_packets_sent >= num_packets){
2636                     conn->num_packets_sent -= num_packets;
2637                 } else {
2638                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2639                     conn->num_packets_sent = 0;
2640                 }
2641                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2642 
2643 #ifdef ENABLE_CLASSIC
2644                 // For SCO, we do the can_send_now_check here
2645                 hci_notify_if_sco_can_send_now();
2646 #endif
2647             }
2648             break;
2649         }
2650 
2651 #ifdef ENABLE_CLASSIC
2652         case HCI_EVENT_INQUIRY_COMPLETE:
2653             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2654                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2655                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2656                 hci_emit_event(event, sizeof(event), 1);
2657             }
2658             break;
2659         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2660             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2661                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2662             }
2663             break;
2664         case HCI_EVENT_CONNECTION_REQUEST:
2665             reverse_bd_addr(&packet[2], addr);
2666             link_type = (hci_link_type_t) packet[11];
2667 
2668             // CVE-2020-26555: reject incoming connection from device with same BD ADDR
2669             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0){
2670                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2671                 bd_addr_copy(hci_stack->decline_addr, addr);
2672                 break;
2673             }
2674 
2675             if (hci_stack->gap_classic_accept_callback != NULL){
2676                 if ((*hci_stack->gap_classic_accept_callback)(addr, link_type) == 0){
2677                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2678                     bd_addr_copy(hci_stack->decline_addr, addr);
2679                     break;
2680                 }
2681             }
2682 
2683             // TODO: eval COD 8-10
2684             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), (unsigned int) link_type);
2685             addr_type = (link_type == HCI_LINK_TYPE_ACL) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2686             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2687             if (!conn) {
2688                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2689             }
2690             if (!conn) {
2691                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2692                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2693                 bd_addr_copy(hci_stack->decline_addr, addr);
2694                 break;
2695             }
2696             conn->role  = HCI_ROLE_SLAVE;
2697             conn->state = RECEIVED_CONNECTION_REQUEST;
2698             // store info about eSCO
2699             if (link_type == HCI_LINK_TYPE_ESCO){
2700                 conn->remote_supported_features[0] |= 1;
2701             }
2702             hci_run();
2703             break;
2704 
2705         case HCI_EVENT_CONNECTION_COMPLETE:
2706             // Connection management
2707             reverse_bd_addr(&packet[5], addr);
2708             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2709             addr_type = BD_ADDR_TYPE_ACL;
2710             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2711             if (conn) {
2712                 if (!packet[2]){
2713                     conn->state = OPEN;
2714                     conn->con_handle = little_endian_read_16(packet, 3);
2715 
2716                     // queue set supervision timeout if we're master
2717                     if ((hci_stack->link_supervision_timeout != HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT) && (conn->role == HCI_ROLE_MASTER)){
2718                         connectionSetAuthenticationFlags(conn, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
2719                     }
2720 
2721                     // restart timer
2722                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2723                     btstack_run_loop_add_timer(&conn->timeout);
2724 
2725                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2726 
2727                     hci_emit_nr_connections_changed();
2728                 } else {
2729                     // connection failed
2730                     hci_handle_connection_failed(conn, packet[2]);
2731                 }
2732             }
2733             break;
2734 
2735         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2736             reverse_bd_addr(&packet[5], addr);
2737             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2738             if (packet[2]){
2739                 // connection failed
2740                 break;
2741             }
2742             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2743             if (!conn) {
2744                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2745             }
2746             if (!conn) {
2747                 break;
2748             }
2749             conn->state = OPEN;
2750             conn->con_handle = little_endian_read_16(packet, 3);
2751 
2752 #ifdef ENABLE_SCO_OVER_HCI
2753             // update SCO
2754             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2755                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2756             }
2757             // trigger can send now
2758             if (hci_have_usb_transport()){
2759                 hci_stack->sco_can_send_now = true;
2760             }
2761 #endif
2762 #ifdef HAVE_SCO_TRANSPORT
2763             // configure sco transport
2764             if (hci_stack->sco_transport != NULL){
2765                 sco_format_t sco_format = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? SCO_FORMAT_8_BIT : SCO_FORMAT_16_BIT;
2766                 hci_stack->sco_transport->open(conn->con_handle, sco_format);
2767             }
2768 #endif
2769             break;
2770 
2771         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2772             handle = little_endian_read_16(packet, 3);
2773             conn = hci_connection_for_handle(handle);
2774             if (!conn) break;
2775             if (!packet[2]){
2776                 const uint8_t * features = &packet[5];
2777                 hci_handle_remote_features_page_0(conn, features);
2778 
2779                 // read extended features if possible
2780                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2781                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2782                     break;
2783                 }
2784             }
2785             hci_handle_remote_features_received(conn);
2786             break;
2787 
2788         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2789             handle = little_endian_read_16(packet, 3);
2790             conn = hci_connection_for_handle(handle);
2791             if (!conn) break;
2792             // status = ok, page = 1
2793             if (!packet[2]) {
2794                 uint8_t page_number = packet[5];
2795                 uint8_t maximum_page_number = packet[6];
2796                 const uint8_t * features = &packet[7];
2797                 bool done = false;
2798                 switch (page_number){
2799                     case 1:
2800                         hci_handle_remote_features_page_1(conn, features);
2801                         if (maximum_page_number >= 2){
2802                             // get Secure Connections (Controller) from Page 2 if available
2803                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2804                         } else {
2805                             // otherwise, assume SC (Controller) == SC (Host)
2806                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2807                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2808                             }
2809                             done = true;
2810                         }
2811                         break;
2812                     case 2:
2813                         hci_handle_remote_features_page_2(conn, features);
2814                         done = true;
2815                         break;
2816                     default:
2817                         break;
2818                 }
2819                 if (!done) break;
2820             }
2821             hci_handle_remote_features_received(conn);
2822             break;
2823 
2824         case HCI_EVENT_LINK_KEY_REQUEST:
2825 #ifndef ENABLE_EXPLICIT_LINK_KEY_REPLY
2826             hci_event_link_key_request_get_bd_addr(packet, addr);
2827             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2828             if (!conn) break;
2829 
2830             // lookup link key in db if not cached
2831             if ((conn->link_key_type == INVALID_LINK_KEY) && (hci_stack->link_key_db != NULL)){
2832                 hci_stack->link_key_db->get_link_key(conn->address, conn->link_key, &conn->link_key_type);
2833             }
2834 
2835             // response sent by hci_run()
2836             conn->authentication_flags |= AUTH_FLAG_HANDLE_LINK_KEY_REQUEST;
2837 #endif
2838             break;
2839 
2840         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2841             hci_event_link_key_request_get_bd_addr(packet, addr);
2842             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2843             if (!conn) break;
2844 
2845             hci_pairing_complete(conn, ERROR_CODE_SUCCESS);
2846 
2847             // CVE-2020-26555: ignore NULL link key
2848             // default link_key_type = INVALID_LINK_KEY asserts that NULL key won't be used for encryption
2849             if (btstack_is_null(&packet[8], 16)) break;
2850 
2851             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2852             // Change Connection Encryption keeps link key type
2853             if (link_key_type != CHANGED_COMBINATION_KEY){
2854                 conn->link_key_type = link_key_type;
2855             }
2856 
2857             // cache link key. link keys stored in little-endian format for legacy reasons
2858             memcpy(&conn->link_key, &packet[8], 16);
2859 
2860             // only store link key:
2861             // - if bondable enabled
2862             if (hci_stack->bondable == false) break;
2863             // - if security level sufficient
2864             if (gap_security_level_for_link_key_type(link_key_type) < conn->requested_security_level) break;
2865             // - for SSP, also check if remote side requested bonding as well
2866             if (conn->link_key_type != COMBINATION_KEY){
2867                 bool remote_bonding = conn->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2868                 if (!remote_bonding){
2869                     break;
2870                 }
2871             }
2872             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2873             break;
2874         }
2875 
2876         case HCI_EVENT_PIN_CODE_REQUEST:
2877             hci_event_pin_code_request_get_bd_addr(packet, addr);
2878             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2879             if (!conn) break;
2880 
2881             hci_pairing_started(conn, false);
2882             // abort pairing if: non-bondable mode (pin code request is not forwarded to app)
2883             if (!hci_stack->bondable ){
2884                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2885                 hci_pairing_complete(conn, ERROR_CODE_PAIRING_NOT_ALLOWED);
2886                 hci_run();
2887                 return;
2888             }
2889             // abort pairing if: LEVEL_4 required (pin code request is not forwarded to app)
2890             if ((hci_stack->gap_secure_connections_only_mode) || (conn->requested_security_level == LEVEL_4)){
2891                 log_info("Level 4 required, but SC not supported -> abort");
2892                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2893                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2894                 hci_run();
2895                 return;
2896             }
2897             break;
2898 
2899         case HCI_EVENT_IO_CAPABILITY_RESPONSE:
2900             hci_event_io_capability_response_get_bd_addr(packet, addr);
2901             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2902             if (!conn) break;
2903 
2904             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE);
2905             hci_pairing_started(conn, true);
2906             conn->io_cap_response_auth_req = hci_event_io_capability_response_get_authentication_requirements(packet);
2907             conn->io_cap_response_io       = hci_event_io_capability_response_get_io_capability(packet);
2908 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2909             conn->io_cap_response_oob_data = hci_event_io_capability_response_get_oob_data_present(packet);
2910 #endif
2911             break;
2912 
2913         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2914             hci_event_io_capability_response_get_bd_addr(packet, addr);
2915             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2916             if (!conn) break;
2917 
2918             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
2919             hci_connection_timestamp(conn);
2920             hci_pairing_started(conn, true);
2921             break;
2922 
2923 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2924         case HCI_EVENT_REMOTE_OOB_DATA_REQUEST:
2925             hci_event_remote_oob_data_request_get_bd_addr(packet, addr);
2926             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2927             if (!conn) break;
2928 
2929             hci_connection_timestamp(conn);
2930 
2931             hci_pairing_started(conn, true);
2932 
2933             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
2934             break;
2935 #endif
2936 
2937         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2938             hci_event_user_confirmation_request_get_bd_addr(packet, addr);
2939             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2940             if (!conn) break;
2941             if (hci_ssp_security_level_possible_for_io_cap(conn->requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io)) {
2942                 if (hci_stack->ssp_auto_accept){
2943                     hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
2944                 };
2945             } else {
2946                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2947                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
2948                 // don't forward event to app
2949                 hci_run();
2950                 return;
2951             }
2952             break;
2953 
2954         case HCI_EVENT_USER_PASSKEY_REQUEST:
2955             // Pairing using Passkey results in MITM protection. If Level 4 is required, support for SC is validated on IO Cap Request
2956             if (hci_stack->ssp_auto_accept){
2957                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
2958             };
2959             break;
2960 
2961         case HCI_EVENT_MODE_CHANGE:
2962             handle = hci_event_mode_change_get_handle(packet);
2963             conn = hci_connection_for_handle(handle);
2964             if (!conn) break;
2965             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2966             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2967             break;
2968 #endif
2969 
2970         case HCI_EVENT_ENCRYPTION_CHANGE:
2971             handle = hci_event_encryption_change_get_connection_handle(packet);
2972             conn = hci_connection_for_handle(handle);
2973             if (!conn) break;
2974             if (hci_event_encryption_change_get_status(packet) == 0u) {
2975                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2976                 if (encryption_enabled){
2977                     if (hci_is_le_connection(conn)){
2978                         // For LE, we accept connection as encrypted
2979                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2980                     }
2981 #ifdef ENABLE_CLASSIC
2982                     else {
2983 
2984                         // dedicated bonding: send result and disconnect
2985                         if (conn->bonding_flags & BONDING_DEDICATED){
2986                             conn->bonding_flags &= ~BONDING_DEDICATED;
2987                             conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
2988                             conn->bonding_status = packet[2];
2989                             break;
2990                         }
2991 
2992                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
2993                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
2994                         bool connected_uses_aes_ccm = encryption_enabled == 2;
2995                         if (hci_stack->secure_connections_active && sc_used_during_pairing && !connected_uses_aes_ccm){
2996                             log_info("SC during pairing, but only E0 now -> abort");
2997                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2998                             break;
2999                         }
3000 
3001                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
3002                         if (connected_uses_aes_ccm){
3003                             conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3004                         }
3005 
3006 #ifdef ENABLE_TESTING_SUPPORT
3007                         // work around for issue with PTS dongle
3008                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3009 #endif
3010 
3011                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
3012                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
3013                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3014                         } else {
3015                             // if not, pretend everything is perfect
3016                             hci_handle_read_encryption_key_size_complete(conn, 16);
3017                         }
3018                     }
3019 #endif
3020                 } else {
3021                     conn->authentication_flags &= ~AUTH_FLAG_CONNECTION_ENCRYPTED;
3022                 }
3023             }
3024 
3025             break;
3026 
3027 #ifdef ENABLE_CLASSIC
3028         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
3029             handle = hci_event_authentication_complete_get_connection_handle(packet);
3030             conn = hci_connection_for_handle(handle);
3031             if (!conn) break;
3032 
3033             // clear authentication active flag
3034             conn->bonding_flags &= ~BONDING_SENT_AUTHENTICATE_REQUEST;
3035             hci_pairing_complete(conn, hci_event_authentication_complete_get_status(packet));
3036 
3037             // authenticated only if auth status == 0
3038             if (hci_event_authentication_complete_get_status(packet) == 0){
3039                 // authenticated
3040                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3041 
3042                 // If not already encrypted, start encryption
3043                 if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0){
3044                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3045                     break;
3046                 }
3047             }
3048 
3049             // emit updated security level
3050             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
3051             break;
3052 
3053         case HCI_EVENT_SIMPLE_PAIRING_COMPLETE:
3054             hci_event_simple_pairing_complete_get_bd_addr(packet, addr);
3055             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3056             if (!conn) break;
3057 
3058             // treat successfully paired connection as authenticated
3059             if (hci_event_simple_pairing_complete_get_status(packet) == ERROR_CODE_SUCCESS){
3060                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3061             }
3062 
3063             hci_pairing_complete(conn, hci_event_simple_pairing_complete_get_status(packet));
3064             break;
3065 #endif
3066 
3067         // HCI_EVENT_DISCONNECTION_COMPLETE
3068         // has been split, to first notify stack before shutting connection down
3069         // see end of function, too.
3070         case HCI_EVENT_DISCONNECTION_COMPLETE:
3071             if (packet[2]) break;   // status != 0
3072             handle = little_endian_read_16(packet, 3);
3073             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
3074             if (hci_stack->acl_fragmentation_total_size > 0u) {
3075                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
3076                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
3077                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
3078                     hci_stack->acl_fragmentation_total_size = 0;
3079                     hci_stack->acl_fragmentation_pos = 0;
3080                     if (release_buffer){
3081                         hci_release_packet_buffer();
3082                     }
3083                 }
3084             }
3085 
3086             conn = hci_connection_for_handle(handle);
3087             if (!conn) break;
3088 #ifdef ENABLE_CLASSIC
3089             // pairing failed if it was ongoing
3090             hci_pairing_complete(conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3091 #endif
3092 
3093             // emit dedicatd bonding event
3094             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
3095                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
3096             }
3097 
3098             // mark connection for shutdown, stop timers, reset state
3099             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
3100             hci_connection_stop_timer(conn);
3101             hci_connection_init(conn);
3102 
3103 #ifdef ENABLE_BLE
3104 #ifdef ENABLE_LE_PERIPHERAL
3105             // re-enable advertisements for le connections if active
3106             if (hci_is_le_connection(conn)){
3107                 hci_update_advertisements_enabled_for_current_roles();
3108             }
3109 #endif
3110 #endif
3111             break;
3112 
3113         case HCI_EVENT_HARDWARE_ERROR:
3114             log_error("Hardware Error: 0x%02x", packet[2]);
3115             if (hci_stack->hardware_error_callback){
3116                 (*hci_stack->hardware_error_callback)(packet[2]);
3117             } else {
3118                 // if no special requests, just reboot stack
3119                 hci_power_control_off();
3120                 hci_power_control_on();
3121             }
3122             break;
3123 
3124 #ifdef ENABLE_CLASSIC
3125         case HCI_EVENT_ROLE_CHANGE:
3126             if (packet[2]) break;   // status != 0
3127             reverse_bd_addr(&packet[3], addr);
3128             addr_type = BD_ADDR_TYPE_ACL;
3129             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3130             if (!conn) break;
3131             conn->role = packet[9];
3132             break;
3133 #endif
3134 
3135         case HCI_EVENT_TRANSPORT_PACKET_SENT:
3136             // release packet buffer only for asynchronous transport and if there are not further fragements
3137             if (hci_transport_synchronous()) {
3138                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
3139                 return; // instead of break: to avoid re-entering hci_run()
3140             }
3141             hci_stack->acl_fragmentation_tx_active = 0;
3142             if (hci_stack->acl_fragmentation_total_size) break;
3143             hci_release_packet_buffer();
3144 
3145             // L2CAP receives this event via the hci_emit_event below
3146 
3147 #ifdef ENABLE_CLASSIC
3148             // For SCO, we do the can_send_now_check here
3149             hci_notify_if_sco_can_send_now();
3150 #endif
3151             break;
3152 
3153 #ifdef ENABLE_CLASSIC
3154         case HCI_EVENT_SCO_CAN_SEND_NOW:
3155             // For SCO, we do the can_send_now_check here
3156             hci_stack->sco_can_send_now = true;
3157             hci_notify_if_sco_can_send_now();
3158             return;
3159 
3160         // explode inquriy results for easier consumption
3161         case HCI_EVENT_INQUIRY_RESULT:
3162         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
3163         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
3164             gap_inquiry_explode(packet, size);
3165             break;
3166 #endif
3167 
3168 #ifdef ENABLE_BLE
3169         case HCI_EVENT_LE_META:
3170             switch (packet[2]){
3171 #ifdef ENABLE_LE_CENTRAL
3172                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
3173                     // log_info("advertising report received");
3174                     if (!hci_stack->le_scanning_enabled) break;
3175                     le_handle_advertisement_report(packet, size);
3176                     break;
3177 #endif
3178                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
3179 					event_handle_le_connection_complete(packet);
3180                     break;
3181 
3182                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
3183                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
3184                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
3185                     conn = hci_connection_for_handle(handle);
3186                     if (!conn) break;
3187                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
3188                     break;
3189 
3190                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
3191                     // connection
3192                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
3193                     conn = hci_connection_for_handle(handle);
3194                     if (conn) {
3195                         // read arguments
3196                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
3197                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
3198                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
3199                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
3200 
3201                         // validate against current connection parameter range
3202                         le_connection_parameter_range_t existing_range;
3203                         gap_get_connection_parameter_range(&existing_range);
3204                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
3205                         if (update_parameter){
3206                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
3207                             conn->le_conn_interval_min = le_conn_interval_min;
3208                             conn->le_conn_interval_max = le_conn_interval_max;
3209                             conn->le_conn_latency = le_conn_latency;
3210                             conn->le_supervision_timeout = le_supervision_timeout;
3211                         } else {
3212                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NEGATIVE_REPLY;
3213                         }
3214                     }
3215                     break;
3216 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
3217                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
3218                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
3219                     conn = hci_connection_for_handle(handle);
3220                     if (conn) {
3221                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
3222                     }
3223                     break;
3224 #endif
3225                 default:
3226                     break;
3227             }
3228             break;
3229 #endif
3230         case HCI_EVENT_VENDOR_SPECIFIC:
3231             // Vendor specific commands often create vendor specific event instead of num completed packets
3232             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
3233             switch (hci_stack->manufacturer){
3234                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
3235                     hci_stack->num_cmd_packets = 1;
3236                     break;
3237                 default:
3238                     break;
3239             }
3240             break;
3241         default:
3242             break;
3243     }
3244 
3245     handle_event_for_current_stack_state(packet, size);
3246 
3247     // notify upper stack
3248 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
3249 
3250     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
3251     if ((hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE) && (packet[2] == 0)){
3252 		handle = little_endian_read_16(packet, 3);
3253 		hci_connection_t * aConn = hci_connection_for_handle(handle);
3254 		// discard connection if app did not trigger a reconnect in the event handler
3255 		if (aConn && aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
3256 			hci_shutdown_connection(aConn);
3257 		}
3258     }
3259 
3260 	// execute main loop
3261 	hci_run();
3262 }
3263 
3264 #ifdef ENABLE_CLASSIC
3265 
3266 #ifdef ENABLE_SCO_OVER_HCI
3267 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
3268 static void sco_schedule_tx(hci_connection_t * conn);
3269 
3270 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
3271     log_debug("SCO TX Timeout");
3272     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
3273     hci_connection_t * conn = hci_connection_for_handle(con_handle);
3274     if (!conn) return;
3275 
3276     // trigger send
3277     conn->sco_tx_ready = 1;
3278     // extra packet if CVSD but SCO buffer is too short
3279     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
3280         conn->sco_tx_ready++;
3281     }
3282     hci_notify_if_sco_can_send_now();
3283 }
3284 
3285 
3286 #define SCO_TX_AFTER_RX_MS (6)
3287 
3288 static void sco_schedule_tx(hci_connection_t * conn){
3289 
3290     uint32_t now = btstack_run_loop_get_time_ms();
3291     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
3292     int time_delta_ms = sco_tx_ms - now;
3293 
3294     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
3295 
3296     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
3297     btstack_run_loop_remove_timer(timer);
3298     btstack_run_loop_set_timer(timer, time_delta_ms);
3299     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
3300     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
3301     btstack_run_loop_add_timer(timer);
3302 }
3303 #endif
3304 
3305 static void sco_handler(uint8_t * packet, uint16_t size){
3306     // lookup connection struct
3307     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
3308     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
3309     if (!conn) return;
3310 
3311 #ifdef ENABLE_SCO_OVER_HCI
3312     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
3313     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
3314         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
3315             packet[2] = 0x3c;
3316             memmove(&packet[3], &packet[23], 63);
3317             size = 63;
3318         }
3319     }
3320 
3321     if (hci_have_usb_transport()){
3322         // Nothing to do
3323     } else {
3324         // 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);
3325         if (hci_stack->synchronous_flow_control_enabled == 0){
3326             uint32_t now = btstack_run_loop_get_time_ms();
3327 
3328             if (!conn->sco_rx_valid){
3329                 // ignore first 10 packets
3330                 conn->sco_rx_count++;
3331                 // log_debug("sco rx count %u", conn->sco_rx_count);
3332                 if (conn->sco_rx_count == 10) {
3333                     // use first timestamp as is and pretent it just started
3334                     conn->sco_rx_ms = now;
3335                     conn->sco_rx_valid = 1;
3336                     conn->sco_rx_count = 0;
3337                     sco_schedule_tx(conn);
3338                 }
3339             } else {
3340                 // track expected arrival timme
3341                 conn->sco_rx_count++;
3342                 conn->sco_rx_ms += 7;
3343                 int delta = (int32_t) (now - conn->sco_rx_ms);
3344                 if (delta > 0){
3345                     conn->sco_rx_ms++;
3346                 }
3347                 // log_debug("sco rx %u", conn->sco_rx_ms);
3348                 sco_schedule_tx(conn);
3349             }
3350         }
3351     }
3352 #endif
3353 
3354     // deliver to app
3355     if (hci_stack->sco_packet_handler) {
3356         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
3357     }
3358 
3359 #ifdef HAVE_SCO_TRANSPORT
3360     // We can send one packet for each received packet
3361     conn->sco_tx_ready++;
3362     hci_notify_if_sco_can_send_now();
3363 #endif
3364 
3365 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3366     conn->num_packets_completed++;
3367     hci_stack->host_completed_packets = 1;
3368     hci_run();
3369 #endif
3370 }
3371 #endif
3372 
3373 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
3374     hci_dump_packet(packet_type, 1, packet, size);
3375     switch (packet_type) {
3376         case HCI_EVENT_PACKET:
3377             event_handler(packet, size);
3378             break;
3379         case HCI_ACL_DATA_PACKET:
3380             acl_handler(packet, size);
3381             break;
3382 #ifdef ENABLE_CLASSIC
3383         case HCI_SCO_DATA_PACKET:
3384             sco_handler(packet, size);
3385             break;
3386 #endif
3387         default:
3388             break;
3389     }
3390 }
3391 
3392 /**
3393  * @brief Add event packet handler.
3394  */
3395 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
3396     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3397 }
3398 
3399 /**
3400  * @brief Remove event packet handler.
3401  */
3402 void hci_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){
3403     btstack_linked_list_remove(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3404 }
3405 
3406 /** Register HCI packet handlers */
3407 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
3408     hci_stack->acl_packet_handler = handler;
3409 }
3410 
3411 #ifdef ENABLE_CLASSIC
3412 /**
3413  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
3414  */
3415 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
3416     hci_stack->sco_packet_handler = handler;
3417 }
3418 #endif
3419 
3420 static void hci_state_reset(void){
3421     // no connections yet
3422     hci_stack->connections = NULL;
3423 
3424     // keep discoverable/connectable as this has been requested by the client(s)
3425     // hci_stack->discoverable = 0;
3426     // hci_stack->connectable = 0;
3427     // hci_stack->bondable = 1;
3428     // hci_stack->own_addr_type = 0;
3429 
3430     // buffer is free
3431     hci_stack->hci_packet_buffer_reserved = false;
3432 
3433     // no pending cmds
3434     hci_stack->decline_reason = 0;
3435 
3436     hci_stack->secure_connections_active = false;
3437 
3438 #ifdef ENABLE_CLASSIC
3439     hci_stack->inquiry_lap = GAP_IAC_GENERAL_INQUIRY;
3440     hci_stack->gap_tasks =
3441             GAP_TASK_SET_DEFAULT_LINK_POLICY |
3442             GAP_TASK_SET_CLASS_OF_DEVICE |
3443             GAP_TASK_SET_LOCAL_NAME |
3444             GAP_TASK_SET_EIR_DATA |
3445             GAP_TASK_WRITE_SCAN_ENABLE;
3446 #endif
3447 
3448 #ifdef ENABLE_CLASSIC_PAIRING_OOB
3449     hci_stack->classic_read_local_oob_data = false;
3450     hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
3451 #endif
3452 
3453     // LE
3454 #ifdef ENABLE_BLE
3455     memset(hci_stack->le_random_address, 0, 6);
3456     hci_stack->le_random_address_set = 0;
3457 #endif
3458 #ifdef ENABLE_LE_CENTRAL
3459     hci_stack->le_scanning_active  = false;
3460     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3461     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
3462     hci_stack->le_whitelist_capacity = 0;
3463 #endif
3464 #ifdef ENABLE_LE_PERIPHERAL
3465     hci_stack->le_advertisements_active = false;
3466     if ((hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_PARAMS_SET) != 0){
3467         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3468     }
3469     if (hci_stack->le_advertisements_data != NULL){
3470         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3471     }
3472 #endif
3473 }
3474 
3475 #ifdef ENABLE_CLASSIC
3476 /**
3477  * @brief Configure Bluetooth hardware control. Has to be called before power on.
3478  */
3479 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
3480     // store and open remote device db
3481     hci_stack->link_key_db = link_key_db;
3482     if (hci_stack->link_key_db) {
3483         hci_stack->link_key_db->open();
3484     }
3485 }
3486 #endif
3487 
3488 void hci_init(const hci_transport_t *transport, const void *config){
3489 
3490 #ifdef HAVE_MALLOC
3491     if (!hci_stack) {
3492         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
3493     }
3494 #else
3495     hci_stack = &hci_stack_static;
3496 #endif
3497     memset(hci_stack, 0, sizeof(hci_stack_t));
3498 
3499     // reference to use transport layer implementation
3500     hci_stack->hci_transport = transport;
3501 
3502     // reference to used config
3503     hci_stack->config = config;
3504 
3505     // setup pointer for outgoing packet buffer
3506     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3507 
3508     // max acl payload size defined in config.h
3509     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3510 
3511     // register packet handlers with transport
3512     transport->register_packet_handler(&packet_handler);
3513 
3514     hci_stack->state = HCI_STATE_OFF;
3515 
3516     // class of device
3517     hci_stack->class_of_device = 0x007a020c; // Smartphone
3518 
3519     // bondable by default
3520     hci_stack->bondable = 1;
3521 
3522 #ifdef ENABLE_CLASSIC
3523     // classic name
3524     hci_stack->local_name = default_classic_name;
3525 
3526     // Master slave policy
3527     hci_stack->master_slave_policy = 1;
3528 
3529     // Allow Role Switch
3530     hci_stack->allow_role_switch = 1;
3531 
3532     // Default / minimum security level = 2
3533     hci_stack->gap_security_level = LEVEL_2;
3534 
3535     // Default Security Mode 4
3536     hci_stack->gap_security_mode = GAP_SECURITY_MODE_4;
3537 
3538     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3539     hci_stack->gap_required_encyrption_key_size = 7;
3540 
3541     // Link Supervision Timeout
3542     hci_stack->link_supervision_timeout = HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT;
3543 
3544 #endif
3545 
3546     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3547     hci_stack->ssp_enable = 1;
3548     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3549     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3550     hci_stack->ssp_auto_accept = 1;
3551 
3552     // Secure Connections: enable (requires support from Controller)
3553     hci_stack->secure_connections_enable = true;
3554 
3555     // voice setting - signed 16 bit pcm data with CVSD over the air
3556     hci_stack->sco_voice_setting = 0x60;
3557 
3558 #ifdef ENABLE_LE_CENTRAL
3559     // connection parameter to use for outgoing connections
3560     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3561     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3562     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3563     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3564     hci_stack->le_connection_latency      = 4;         // 4
3565     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3566     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3567     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3568 
3569     // default LE Scanning
3570     hci_stack->le_scan_type     =   0x1; // active
3571     hci_stack->le_scan_interval = 0x1e0; // 300 ms
3572     hci_stack->le_scan_window   =  0x30; //  30 ms
3573 #endif
3574 
3575 #ifdef ENABLE_LE_PERIPHERAL
3576     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3577 #endif
3578 
3579     // connection parameter range used to answer connection parameter update requests in l2cap
3580     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3581     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3582     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3583     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3584     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3585     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3586 
3587     hci_state_reset();
3588 }
3589 
3590 void hci_deinit(void){
3591 #ifdef HAVE_MALLOC
3592     if (hci_stack) {
3593         free(hci_stack);
3594     }
3595 #endif
3596     hci_stack = NULL;
3597 
3598 #ifdef ENABLE_CLASSIC
3599     disable_l2cap_timeouts = 0;
3600 #endif
3601 }
3602 
3603 /**
3604  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3605  */
3606 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3607     hci_stack->chipset = chipset_driver;
3608 
3609     // reset chipset driver - init is also called on power_up
3610     if (hci_stack->chipset && hci_stack->chipset->init){
3611         hci_stack->chipset->init(hci_stack->config);
3612     }
3613 }
3614 
3615 /**
3616  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3617  */
3618 void hci_set_control(const btstack_control_t *hardware_control){
3619     // references to used control implementation
3620     hci_stack->control = hardware_control;
3621     // init with transport config
3622     hardware_control->init(hci_stack->config);
3623 }
3624 
3625 void hci_close(void){
3626 
3627 #ifdef ENABLE_CLASSIC
3628     // close remote device db
3629     if (hci_stack->link_key_db) {
3630         hci_stack->link_key_db->close();
3631     }
3632 #endif
3633 
3634     btstack_linked_list_iterator_t lit;
3635     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3636     while (btstack_linked_list_iterator_has_next(&lit)){
3637         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3638         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3639         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3640         hci_shutdown_connection(connection);
3641     }
3642 
3643     hci_power_control(HCI_POWER_OFF);
3644 
3645 #ifdef HAVE_MALLOC
3646     free(hci_stack);
3647 #endif
3648     hci_stack = NULL;
3649 }
3650 
3651 #ifdef HAVE_SCO_TRANSPORT
3652 void hci_set_sco_transport(const btstack_sco_transport_t *sco_transport){
3653     hci_stack->sco_transport = sco_transport;
3654     sco_transport->register_packet_handler(&packet_handler);
3655 }
3656 #endif
3657 
3658 #ifdef ENABLE_CLASSIC
3659 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3660     // validate ranage and set
3661     if (encryption_key_size < 7)  return;
3662     if (encryption_key_size > 16) return;
3663     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3664 }
3665 
3666 uint8_t gap_set_security_mode(gap_security_mode_t security_mode){
3667     if ((security_mode == GAP_SECURITY_MODE_4) || (security_mode == GAP_SECURITY_MODE_2)){
3668         hci_stack->gap_security_mode = security_mode;
3669         return ERROR_CODE_SUCCESS;
3670     } else {
3671         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3672     }
3673 }
3674 
3675 gap_security_mode_t gap_get_security_mode(void){
3676     return hci_stack->gap_security_mode;
3677 }
3678 
3679 void gap_set_security_level(gap_security_level_t security_level){
3680     hci_stack->gap_security_level = security_level;
3681 }
3682 
3683 gap_security_level_t gap_get_security_level(void){
3684     if (hci_stack->gap_secure_connections_only_mode){
3685         return LEVEL_4;
3686     }
3687     return hci_stack->gap_security_level;
3688 }
3689 
3690 void gap_set_minimal_service_security_level(gap_security_level_t security_level){
3691     hci_stack->gap_minimal_service_security_level = security_level;
3692 }
3693 
3694 void gap_set_secure_connections_only_mode(bool enable){
3695     hci_stack->gap_secure_connections_only_mode = enable;
3696 }
3697 
3698 bool gap_get_secure_connections_only_mode(void){
3699     return hci_stack->gap_secure_connections_only_mode;
3700 }
3701 #endif
3702 
3703 #ifdef ENABLE_CLASSIC
3704 void gap_set_class_of_device(uint32_t class_of_device){
3705     hci_stack->class_of_device = class_of_device;
3706     hci_stack->gap_tasks |= GAP_TASK_SET_CLASS_OF_DEVICE;
3707     hci_run();
3708 }
3709 
3710 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3711     hci_stack->default_link_policy_settings = default_link_policy_settings;
3712     hci_stack->gap_tasks |= GAP_TASK_SET_DEFAULT_LINK_POLICY;
3713     hci_run();
3714 }
3715 
3716 void gap_set_allow_role_switch(bool allow_role_switch){
3717     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3718 }
3719 
3720 uint8_t hci_get_allow_role_switch(void){
3721     return  hci_stack->allow_role_switch;
3722 }
3723 
3724 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3725     hci_stack->link_supervision_timeout = link_supervision_timeout;
3726 }
3727 
3728 void hci_disable_l2cap_timeout_check(void){
3729     disable_l2cap_timeouts = 1;
3730 }
3731 #endif
3732 
3733 #ifndef HAVE_HOST_CONTROLLER_API
3734 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3735 void hci_set_bd_addr(bd_addr_t addr){
3736     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3737     hci_stack->custom_bd_addr_set = 1;
3738 }
3739 #endif
3740 
3741 // State-Module-Driver overview
3742 // state                    module  low-level
3743 // HCI_STATE_OFF             off      close
3744 // HCI_STATE_INITIALIZING,   on       open
3745 // HCI_STATE_WORKING,        on       open
3746 // HCI_STATE_HALTING,        on       open
3747 // HCI_STATE_SLEEPING,    off/sleep   close
3748 // HCI_STATE_FALLING_ASLEEP  on       open
3749 
3750 static int hci_power_control_on(void){
3751 
3752     // power on
3753     int err = 0;
3754     if (hci_stack->control && hci_stack->control->on){
3755         err = (*hci_stack->control->on)();
3756     }
3757     if (err){
3758         log_error( "POWER_ON failed");
3759         hci_emit_hci_open_failed();
3760         return err;
3761     }
3762 
3763     // int chipset driver
3764     if (hci_stack->chipset && hci_stack->chipset->init){
3765         hci_stack->chipset->init(hci_stack->config);
3766     }
3767 
3768     // init transport
3769     if (hci_stack->hci_transport->init){
3770         hci_stack->hci_transport->init(hci_stack->config);
3771     }
3772 
3773     // open transport
3774     err = hci_stack->hci_transport->open();
3775     if (err){
3776         log_error( "HCI_INIT failed, turning Bluetooth off again");
3777         if (hci_stack->control && hci_stack->control->off){
3778             (*hci_stack->control->off)();
3779         }
3780         hci_emit_hci_open_failed();
3781         return err;
3782     }
3783     return 0;
3784 }
3785 
3786 static void hci_power_control_off(void){
3787 
3788     log_info("hci_power_control_off");
3789 
3790     // close low-level device
3791     hci_stack->hci_transport->close();
3792 
3793     log_info("hci_power_control_off - hci_transport closed");
3794 
3795     // power off
3796     if (hci_stack->control && hci_stack->control->off){
3797         (*hci_stack->control->off)();
3798     }
3799 
3800     log_info("hci_power_control_off - control closed");
3801 
3802     hci_stack->state = HCI_STATE_OFF;
3803 }
3804 
3805 static void hci_power_control_sleep(void){
3806 
3807     log_info("hci_power_control_sleep");
3808 
3809 #if 0
3810     // don't close serial port during sleep
3811 
3812     // close low-level device
3813     hci_stack->hci_transport->close(hci_stack->config);
3814 #endif
3815 
3816     // sleep mode
3817     if (hci_stack->control && hci_stack->control->sleep){
3818         (*hci_stack->control->sleep)();
3819     }
3820 
3821     hci_stack->state = HCI_STATE_SLEEPING;
3822 }
3823 
3824 static int hci_power_control_wake(void){
3825 
3826     log_info("hci_power_control_wake");
3827 
3828     // wake on
3829     if (hci_stack->control && hci_stack->control->wake){
3830         (*hci_stack->control->wake)();
3831     }
3832 
3833 #if 0
3834     // open low-level device
3835     int err = hci_stack->hci_transport->open(hci_stack->config);
3836     if (err){
3837         log_error( "HCI_INIT failed, turning Bluetooth off again");
3838         if (hci_stack->control && hci_stack->control->off){
3839             (*hci_stack->control->off)();
3840         }
3841         hci_emit_hci_open_failed();
3842         return err;
3843     }
3844 #endif
3845 
3846     return 0;
3847 }
3848 
3849 static void hci_power_transition_to_initializing(void){
3850     // set up state machine
3851     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3852     hci_stack->hci_packet_buffer_reserved = false;
3853     hci_stack->state = HCI_STATE_INITIALIZING;
3854     hci_stack->substate = HCI_INIT_SEND_RESET;
3855 }
3856 
3857 // returns error
3858 static int hci_power_control_state_off(HCI_POWER_MODE power_mode){
3859     int err;
3860     switch (power_mode){
3861         case HCI_POWER_ON:
3862             err = hci_power_control_on();
3863             if (err != 0) {
3864                 log_error("hci_power_control_on() error %d", err);
3865                 return err;
3866             }
3867             hci_power_transition_to_initializing();
3868             break;
3869         case HCI_POWER_OFF:
3870             // do nothing
3871             break;
3872         case HCI_POWER_SLEEP:
3873             // do nothing (with SLEEP == OFF)
3874             break;
3875         default:
3876             btstack_assert(false);
3877             break;
3878     }
3879     return ERROR_CODE_SUCCESS;
3880 }
3881 
3882 static int hci_power_control_state_initializing(HCI_POWER_MODE power_mode){
3883     switch (power_mode){
3884         case HCI_POWER_ON:
3885             // do nothing
3886             break;
3887         case HCI_POWER_OFF:
3888             // no connections yet, just turn it off
3889             hci_power_control_off();
3890             break;
3891         case HCI_POWER_SLEEP:
3892             // no connections yet, just turn it off
3893             hci_power_control_sleep();
3894             break;
3895         default:
3896             btstack_assert(false);
3897             break;
3898     }
3899     return ERROR_CODE_SUCCESS;
3900 }
3901 
3902 static int hci_power_control_state_working(HCI_POWER_MODE power_mode) {
3903     switch (power_mode){
3904         case HCI_POWER_ON:
3905             // do nothing
3906             break;
3907         case HCI_POWER_OFF:
3908             // see hci_run
3909             hci_stack->state = HCI_STATE_HALTING;
3910             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3911             break;
3912         case HCI_POWER_SLEEP:
3913             // see hci_run
3914             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3915             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3916             break;
3917         default:
3918             btstack_assert(false);
3919             break;
3920     }
3921     return ERROR_CODE_SUCCESS;
3922 }
3923 
3924 static int hci_power_control_state_halting(HCI_POWER_MODE power_mode) {
3925     switch (power_mode){
3926         case HCI_POWER_ON:
3927             hci_power_transition_to_initializing();
3928             break;
3929         case HCI_POWER_OFF:
3930             // do nothing
3931             break;
3932         case HCI_POWER_SLEEP:
3933             // see hci_run
3934             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3935             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3936             break;
3937         default:
3938             btstack_assert(false);
3939             break;
3940     }
3941     return ERROR_CODE_SUCCESS;
3942 }
3943 
3944 static int hci_power_control_state_falling_asleep(HCI_POWER_MODE power_mode) {
3945     switch (power_mode){
3946         case HCI_POWER_ON:
3947             hci_power_transition_to_initializing();
3948             break;
3949         case HCI_POWER_OFF:
3950             // see hci_run
3951             hci_stack->state = HCI_STATE_HALTING;
3952             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3953             break;
3954         case HCI_POWER_SLEEP:
3955             // do nothing
3956             break;
3957         default:
3958             btstack_assert(false);
3959             break;
3960     }
3961     return ERROR_CODE_SUCCESS;
3962 }
3963 
3964 static int hci_power_control_state_sleeping(HCI_POWER_MODE power_mode) {
3965     int err;
3966     switch (power_mode){
3967         case HCI_POWER_ON:
3968             err = hci_power_control_wake();
3969             if (err) return err;
3970             hci_power_transition_to_initializing();
3971             break;
3972         case HCI_POWER_OFF:
3973             hci_stack->state = HCI_STATE_HALTING;
3974             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3975             break;
3976         case HCI_POWER_SLEEP:
3977             // do nothing
3978             break;
3979         default:
3980             btstack_assert(false);
3981             break;
3982     }
3983     return ERROR_CODE_SUCCESS;
3984 }
3985 
3986 int hci_power_control(HCI_POWER_MODE power_mode){
3987     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
3988     int err = 0;
3989     switch (hci_stack->state){
3990         case HCI_STATE_OFF:
3991             err = hci_power_control_state_off(power_mode);
3992             break;
3993         case HCI_STATE_INITIALIZING:
3994             err = hci_power_control_state_initializing(power_mode);
3995             break;
3996         case HCI_STATE_WORKING:
3997             err = hci_power_control_state_working(power_mode);
3998             break;
3999         case HCI_STATE_HALTING:
4000             err = hci_power_control_state_halting(power_mode);
4001             break;
4002         case HCI_STATE_FALLING_ASLEEP:
4003             err = hci_power_control_state_falling_asleep(power_mode);
4004             break;
4005         case HCI_STATE_SLEEPING:
4006             err = hci_power_control_state_sleeping(power_mode);
4007             break;
4008         default:
4009             btstack_assert(false);
4010             break;
4011     }
4012     if (err != 0){
4013         return err;
4014     }
4015 
4016     // create internal event
4017 	hci_emit_state();
4018 
4019 	// trigger next/first action
4020 	hci_run();
4021 
4022     return 0;
4023 }
4024 
4025 
4026 #ifdef ENABLE_CLASSIC
4027 
4028 static void hci_update_scan_enable(void){
4029     // 2 = page scan, 1 = inq scan
4030     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
4031     hci_stack->gap_tasks |= GAP_TASK_WRITE_SCAN_ENABLE;
4032     hci_run();
4033 }
4034 
4035 void gap_discoverable_control(uint8_t enable){
4036     if (enable) enable = 1; // normalize argument
4037 
4038     if (hci_stack->discoverable == enable){
4039         hci_emit_discoverable_enabled(hci_stack->discoverable);
4040         return;
4041     }
4042 
4043     hci_stack->discoverable = enable;
4044     hci_update_scan_enable();
4045 }
4046 
4047 void gap_connectable_control(uint8_t enable){
4048     if (enable) enable = 1; // normalize argument
4049 
4050     // don't emit event
4051     if (hci_stack->connectable == enable) return;
4052 
4053     hci_stack->connectable = enable;
4054     hci_update_scan_enable();
4055 }
4056 #endif
4057 
4058 void gap_local_bd_addr(bd_addr_t address_buffer){
4059     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
4060 }
4061 
4062 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4063 static void hci_host_num_completed_packets(void){
4064 
4065     // create packet manually as arrays are not supported and num_commands should not get reduced
4066     hci_reserve_packet_buffer();
4067     uint8_t * packet = hci_get_outgoing_packet_buffer();
4068 
4069     uint16_t size = 0;
4070     uint16_t num_handles = 0;
4071     packet[size++] = 0x35;
4072     packet[size++] = 0x0c;
4073     size++;  // skip param len
4074     size++;  // skip num handles
4075 
4076     // add { handle, packets } entries
4077     btstack_linked_item_t * it;
4078     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
4079         hci_connection_t * connection = (hci_connection_t *) it;
4080         if (connection->num_packets_completed){
4081             little_endian_store_16(packet, size, connection->con_handle);
4082             size += 2;
4083             little_endian_store_16(packet, size, connection->num_packets_completed);
4084             size += 2;
4085             //
4086             num_handles++;
4087             connection->num_packets_completed = 0;
4088         }
4089     }
4090 
4091     packet[2] = size - 3;
4092     packet[3] = num_handles;
4093 
4094     hci_stack->host_completed_packets = 0;
4095 
4096     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4097     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4098 
4099     // release packet buffer for synchronous transport implementations
4100     if (hci_transport_synchronous()){
4101         hci_release_packet_buffer();
4102         hci_emit_transport_packet_sent();
4103     }
4104 }
4105 #endif
4106 
4107 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
4108     UNUSED(ds);
4109     hci_stack->substate = HCI_HALTING_CLOSE;
4110     // allow packet handlers to defer final shutdown
4111     hci_emit_state();
4112     hci_run();
4113 }
4114 
4115 static bool hci_run_acl_fragments(void){
4116     if (hci_stack->acl_fragmentation_total_size > 0u) {
4117         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
4118         hci_connection_t *connection = hci_connection_for_handle(con_handle);
4119         if (connection) {
4120             if (hci_can_send_prepared_acl_packet_now(con_handle)){
4121                 hci_send_acl_packet_fragments(connection);
4122                 return true;
4123             }
4124         } else {
4125             // connection gone -> discard further fragments
4126             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
4127             hci_stack->acl_fragmentation_total_size = 0;
4128             hci_stack->acl_fragmentation_pos = 0;
4129         }
4130     }
4131     return false;
4132 }
4133 
4134 #ifdef ENABLE_CLASSIC
4135 static bool hci_run_general_gap_classic(void){
4136 
4137     // assert stack is working and classic is active
4138     if (hci_classic_supported() == false)      return false;
4139     if (hci_stack->state != HCI_STATE_WORKING) return false;
4140 
4141     // decline incoming connections
4142     if (hci_stack->decline_reason){
4143         uint8_t reason = hci_stack->decline_reason;
4144         hci_stack->decline_reason = 0;
4145         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
4146         return true;
4147     }
4148 
4149     if (hci_stack->gap_tasks != 0){
4150         hci_run_gap_tasks_classic();
4151         return true;
4152     }
4153 
4154     // start/stop inquiry
4155     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
4156         uint8_t duration = hci_stack->inquiry_state;
4157         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_ACTIVE;
4158         hci_send_cmd(&hci_inquiry, hci_stack->inquiry_lap, duration, 0);
4159         return true;
4160     }
4161     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
4162         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
4163         hci_send_cmd(&hci_inquiry_cancel);
4164         return true;
4165     }
4166     // remote name request
4167     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
4168         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
4169         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
4170                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
4171         return true;
4172     }
4173 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4174     // Local OOB data
4175     if (hci_stack->classic_read_local_oob_data){
4176         hci_stack->classic_read_local_oob_data = false;
4177         if (hci_stack->local_supported_commands[1] & 0x10u){
4178             hci_send_cmd(&hci_read_local_extended_oob_data);
4179         } else {
4180             hci_send_cmd(&hci_read_local_oob_data);
4181         }
4182     }
4183 #endif
4184     // pairing
4185     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
4186         uint8_t state = hci_stack->gap_pairing_state;
4187         uint8_t pin_code[16];
4188         switch (state){
4189             case GAP_PAIRING_STATE_SEND_PIN:
4190                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4191                 memset(pin_code, 0, 16);
4192                 memcpy(pin_code, hci_stack->gap_pairing_input.gap_pairing_pin, hci_stack->gap_pairing_pin_len);
4193                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_pin_len, pin_code);
4194                 break;
4195             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
4196                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4197                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
4198                 break;
4199             case GAP_PAIRING_STATE_SEND_PASSKEY:
4200                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4201                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
4202                 break;
4203             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
4204                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4205                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
4206                 break;
4207             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
4208                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4209                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
4210                 break;
4211             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
4212                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4213                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
4214                 break;
4215             default:
4216                 break;
4217         }
4218         return true;
4219     }
4220     return false;
4221 }
4222 #endif
4223 
4224 #ifdef ENABLE_BLE
4225 static bool hci_run_general_gap_le(void){
4226 
4227     // advertisements, active scanning, and creating connections requires random address to be set if using private address
4228 
4229     if (hci_stack->state != HCI_STATE_WORKING) return false;
4230     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
4231 
4232 
4233     // Phase 1: collect what to stop
4234 
4235     bool scanning_stop = false;
4236     bool connecting_stop = false;
4237     bool advertising_stop = false;
4238 
4239 #ifndef ENABLE_LE_CENTRAL
4240     UNUSED(scanning_stop);
4241     UNUSED(connecting_stop);
4242 #endif
4243 #ifndef ENABLE_LE_PERIPHERAL
4244     UNUSED(advertising_stop);
4245 #endif
4246 
4247     // check if own address changes
4248     bool random_address_change = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADDRESS) != 0;
4249 
4250     // check if whitelist needs modification
4251     bool whitelist_modification_pending = false;
4252     btstack_linked_list_iterator_t lit;
4253     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4254     while (btstack_linked_list_iterator_has_next(&lit)){
4255         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4256         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
4257             whitelist_modification_pending = true;
4258             break;
4259         }
4260     }
4261     // check if resolving list needs modification
4262     bool resolving_list_modification_pending = false;
4263 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4264     bool resolving_list_supported = (hci_stack->local_supported_commands[1] & (1 << 2)) != 0;
4265 	if (resolving_list_supported && hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_DONE){
4266         resolving_list_modification_pending = true;
4267     }
4268 #endif
4269 
4270 #ifdef ENABLE_LE_CENTRAL
4271     // scanning control
4272     if (hci_stack->le_scanning_active) {
4273         // stop if:
4274         // - parameter change required
4275         // - it's disabled
4276         // - whitelist change required but used for scanning
4277         // - resolving list modified
4278         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
4279         if ((hci_stack->le_scanning_param_update) ||
4280             !hci_stack->le_scanning_enabled ||
4281             scanning_uses_whitelist ||
4282             resolving_list_modification_pending){
4283 
4284             scanning_stop = true;
4285         }
4286     }
4287 #endif
4288 
4289 #ifdef ENABLE_LE_CENTRAL
4290     // connecting control
4291     bool connecting_with_whitelist;
4292     switch (hci_stack->le_connecting_state){
4293         case LE_CONNECTING_DIRECT:
4294         case LE_CONNECTING_WHITELIST:
4295             // stop connecting if:
4296             // - connecting uses white and whitelist modification pending
4297             // - if it got disabled
4298             // - resolving list modified
4299             connecting_with_whitelist = hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST;
4300             if ((connecting_with_whitelist && whitelist_modification_pending) ||
4301                 (hci_stack->le_connecting_request == LE_CONNECTING_IDLE) ||
4302                 resolving_list_modification_pending) {
4303 
4304                 connecting_stop = true;
4305             }
4306             break;
4307         default:
4308             break;
4309     }
4310 #endif
4311 
4312 #ifdef ENABLE_LE_PERIPHERAL
4313     // le advertisement control
4314     if (hci_stack->le_advertisements_active){
4315         // stop if:
4316         // - parameter change required
4317         // - random address used in advertising and changes
4318         // - it's disabled
4319         // - whitelist change required but used for advertisement filter policy
4320         // - resolving list modified
4321         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy != 0;
4322         bool advertising_uses_random_address = hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC;
4323         bool advertising_change    = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS)  != 0;
4324         if (advertising_change ||
4325             (advertising_uses_random_address && random_address_change) ||
4326             (hci_stack->le_advertisements_enabled_for_current_roles == 0) ||
4327             (advertising_uses_whitelist && whitelist_modification_pending) ||
4328             resolving_list_modification_pending) {
4329 
4330             advertising_stop = true;
4331         }
4332     }
4333 #endif
4334 
4335 
4336     // Phase 2: stop everything that should be off during modifications
4337 
4338 #ifdef ENABLE_LE_CENTRAL
4339     if (scanning_stop){
4340         hci_stack->le_scanning_active = false;
4341         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
4342         return true;
4343     }
4344 #endif
4345 
4346 #ifdef ENABLE_LE_CENTRAL
4347     if (connecting_stop){
4348         hci_send_cmd(&hci_le_create_connection_cancel);
4349         return true;
4350     }
4351 #endif
4352 
4353 #ifdef ENABLE_LE_PERIPHERAL
4354     if (advertising_stop){
4355         hci_stack->le_advertisements_active = false;
4356         hci_send_cmd(&hci_le_set_advertise_enable, 0);
4357         return true;
4358     }
4359 #endif
4360 
4361     // Phase 3: modify
4362 
4363     if (random_address_change){
4364         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADDRESS;
4365         hci_send_cmd(&hci_le_set_random_address, hci_stack->le_random_address);
4366         return true;
4367     }
4368 
4369 #ifdef ENABLE_LE_CENTRAL
4370     if (hci_stack->le_scanning_param_update){
4371         hci_stack->le_scanning_param_update = false;
4372         hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
4373                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
4374         return true;
4375     }
4376 #endif
4377 
4378 #ifdef ENABLE_LE_PERIPHERAL
4379     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
4380         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
4381         hci_stack->le_advertisements_own_addr_type = hci_stack->le_own_addr_type;
4382         hci_send_cmd(&hci_le_set_advertising_parameters,
4383                      hci_stack->le_advertisements_interval_min,
4384                      hci_stack->le_advertisements_interval_max,
4385                      hci_stack->le_advertisements_type,
4386                      hci_stack->le_advertisements_own_addr_type,
4387                      hci_stack->le_advertisements_direct_address_type,
4388                      hci_stack->le_advertisements_direct_address,
4389                      hci_stack->le_advertisements_channel_map,
4390                      hci_stack->le_advertisements_filter_policy);
4391         return true;
4392     }
4393     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
4394         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
4395         uint8_t adv_data_clean[31];
4396         memset(adv_data_clean, 0, sizeof(adv_data_clean));
4397         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
4398                      hci_stack->le_advertisements_data_len);
4399         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
4400         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
4401         return true;
4402     }
4403     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
4404         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
4405         uint8_t scan_data_clean[31];
4406         memset(scan_data_clean, 0, sizeof(scan_data_clean));
4407         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
4408                      hci_stack->le_scan_response_data_len);
4409         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
4410         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
4411         return true;
4412     }
4413 #endif
4414 
4415 
4416 #ifdef ENABLE_LE_CENTRAL
4417     // if connect with whitelist was active and is not cancelled yet, wait until next time
4418     if (hci_stack->le_connecting_state == LE_CONNECTING_CANCEL) return false;
4419 #endif
4420 
4421     // LE Whitelist Management
4422     if (whitelist_modification_pending){
4423         // add/remove entries
4424         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4425         while (btstack_linked_list_iterator_has_next(&lit)){
4426             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4427 			if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
4428 				entry->state &= ~LE_WHITELIST_REMOVE_FROM_CONTROLLER;
4429 				hci_send_cmd(&hci_le_remove_device_from_white_list, entry->address_type, entry->address);
4430 				return true;
4431 			}
4432             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
4433 				entry->state &= ~LE_WHITELIST_ADD_TO_CONTROLLER;
4434                 entry->state |= LE_WHITELIST_ON_CONTROLLER;
4435                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
4436                 return true;
4437             }
4438             if ((entry->state & LE_WHITELIST_ON_CONTROLLER) == 0){
4439 				btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4440 				btstack_memory_whitelist_entry_free(entry);
4441             }
4442         }
4443     }
4444 
4445 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4446     // LE Resolving List Management
4447     if (resolving_list_supported) {
4448 		uint16_t i;
4449 		switch (hci_stack->le_resolving_list_state) {
4450 			case LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION:
4451 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
4452 				hci_send_cmd(&hci_le_set_address_resolution_enabled, 1);
4453 				return true;
4454 			case LE_RESOLVING_LIST_READ_SIZE:
4455 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_SEND_CLEAR;
4456 				hci_send_cmd(&hci_le_read_resolving_list_size);
4457 				return true;
4458 			case LE_RESOLVING_LIST_SEND_CLEAR:
4459 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
4460 				(void) memset(hci_stack->le_resolving_list_add_entries, 0xff,
4461 							  sizeof(hci_stack->le_resolving_list_add_entries));
4462 				(void) memset(hci_stack->le_resolving_list_remove_entries, 0,
4463 							  sizeof(hci_stack->le_resolving_list_remove_entries));
4464 				hci_send_cmd(&hci_le_clear_resolving_list);
4465 				return true;
4466 			case LE_RESOLVING_LIST_REMOVE_ENTRIES:
4467 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4468 					uint8_t offset = i >> 3;
4469 					uint8_t mask = 1 << (i & 7);
4470 					if ((hci_stack->le_resolving_list_remove_entries[offset] & mask) == 0) continue;
4471 					hci_stack->le_resolving_list_remove_entries[offset] &= ~mask;
4472 					bd_addr_t peer_identity_addreses;
4473 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4474 					sm_key_t peer_irk;
4475 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4476 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4477 
4478 #ifdef ENABLE_LE_WHITELIST_TOUCH_AFTER_RESOLVING_LIST_UPDATE
4479 					// trigger whitelist entry 'update' (work around for controller bug)
4480 					btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4481 					while (btstack_linked_list_iterator_has_next(&lit)) {
4482 						whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&lit);
4483 						if (entry->address_type != peer_identity_addr_type) continue;
4484 						if (memcmp(entry->address, peer_identity_addreses, 6) != 0) continue;
4485 						log_info("trigger whitelist update %s", bd_addr_to_str(peer_identity_addreses));
4486 						entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER;
4487 					}
4488 #endif
4489 
4490 					hci_send_cmd(&hci_le_remove_device_from_resolving_list, peer_identity_addr_type,
4491 								 peer_identity_addreses);
4492 					return true;
4493 				}
4494 
4495 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_ADD_ENTRIES;
4496 
4497 				/* fall through */
4498 
4499 			case LE_RESOLVING_LIST_ADD_ENTRIES:
4500 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4501 					uint8_t offset = i >> 3;
4502 					uint8_t mask = 1 << (i & 7);
4503 					if ((hci_stack->le_resolving_list_add_entries[offset] & mask) == 0) continue;
4504 					hci_stack->le_resolving_list_add_entries[offset] &= ~mask;
4505 					bd_addr_t peer_identity_addreses;
4506 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4507 					sm_key_t peer_irk;
4508 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4509 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4510 					const uint8_t *local_irk = gap_get_persistent_irk();
4511 					// command uses format specifier 'P' that stores 16-byte value without flip
4512 					uint8_t local_irk_flipped[16];
4513 					uint8_t peer_irk_flipped[16];
4514 					reverse_128(local_irk, local_irk_flipped);
4515 					reverse_128(peer_irk, peer_irk_flipped);
4516 					hci_send_cmd(&hci_le_add_device_to_resolving_list, peer_identity_addr_type, peer_identity_addreses,
4517 								 peer_irk_flipped, local_irk_flipped);
4518 					return true;
4519 				}
4520 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4521 				break;
4522 
4523 			default:
4524 				break;
4525 		}
4526 	}
4527     hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4528 #endif
4529 
4530     // Phase 4: restore state
4531 
4532 #ifdef ENABLE_LE_CENTRAL
4533     // re-start scanning
4534     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
4535         hci_stack->le_scanning_active = true;
4536         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
4537         return true;
4538     }
4539 #endif
4540 
4541 #ifdef ENABLE_LE_CENTRAL
4542     // re-start connecting
4543     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
4544         bd_addr_t null_addr;
4545         memset(null_addr, 0, 6);
4546         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4547         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4548         hci_send_cmd(&hci_le_create_connection,
4549                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
4550                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
4551                      1,         // use whitelist
4552                      0,         // peer address type
4553                      null_addr, // peer bd addr
4554                      hci_stack->le_connection_own_addr_type,   // our addr type:
4555                      hci_stack->le_connection_interval_min,    // conn interval min
4556                      hci_stack->le_connection_interval_max,    // conn interval max
4557                      hci_stack->le_connection_latency,         // conn latency
4558                      hci_stack->le_supervision_timeout,        // conn latency
4559                      hci_stack->le_minimum_ce_length,          // min ce length
4560                      hci_stack->le_maximum_ce_length           // max ce length
4561         );
4562         return true;
4563     }
4564 #endif
4565 
4566 #ifdef ENABLE_LE_PERIPHERAL
4567     // re-start advertising
4568     if (hci_stack->le_advertisements_enabled_for_current_roles && !hci_stack->le_advertisements_active){
4569         // check if advertisements should be enabled given
4570         hci_stack->le_advertisements_active = true;
4571         hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, hci_stack->le_advertisements_own_address);
4572         hci_send_cmd(&hci_le_set_advertise_enable, 1);
4573         return true;
4574     }
4575 #endif
4576 
4577     return false;
4578 }
4579 #endif
4580 
4581 static bool hci_run_general_pending_commands(void){
4582     btstack_linked_item_t * it;
4583     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4584         hci_connection_t * connection = (hci_connection_t *) it;
4585 
4586         switch(connection->state){
4587             case SEND_CREATE_CONNECTION:
4588                 switch(connection->address_type){
4589 #ifdef ENABLE_CLASSIC
4590                     case BD_ADDR_TYPE_ACL:
4591                         log_info("sending hci_create_connection");
4592                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
4593                         break;
4594 #endif
4595                     default:
4596 #ifdef ENABLE_BLE
4597 #ifdef ENABLE_LE_CENTRAL
4598                         log_info("sending hci_le_create_connection");
4599                         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4600                         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4601                         hci_send_cmd(&hci_le_create_connection,
4602                                      hci_stack->le_connection_scan_interval,    // conn scan interval
4603                                      hci_stack->le_connection_scan_window,      // conn scan windows
4604                                      0,         // don't use whitelist
4605                                      connection->address_type, // peer address type
4606                                      connection->address,      // peer bd addr
4607                                      hci_stack->le_connection_own_addr_type,   // our addr type:
4608                                      hci_stack->le_connection_interval_min,    // conn interval min
4609                                      hci_stack->le_connection_interval_max,    // conn interval max
4610                                      hci_stack->le_connection_latency,         // conn latency
4611                                      hci_stack->le_supervision_timeout,        // conn latency
4612                                      hci_stack->le_minimum_ce_length,          // min ce length
4613                                      hci_stack->le_maximum_ce_length          // max ce length
4614                         );
4615                         connection->state = SENT_CREATE_CONNECTION;
4616 #endif
4617 #endif
4618                         break;
4619                 }
4620                 return true;
4621 
4622 #ifdef ENABLE_CLASSIC
4623             case RECEIVED_CONNECTION_REQUEST:
4624                 connection->role  = HCI_ROLE_SLAVE;
4625                 if (connection->address_type == BD_ADDR_TYPE_ACL){
4626                     log_info("sending hci_accept_connection_request");
4627                     connection->state = ACCEPTED_CONNECTION_REQUEST;
4628                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
4629                 }
4630                 return true;
4631 #endif
4632 
4633 #ifdef ENABLE_BLE
4634 #ifdef ENABLE_LE_CENTRAL
4635             case SEND_CANCEL_CONNECTION:
4636                 connection->state = SENT_CANCEL_CONNECTION;
4637                 hci_send_cmd(&hci_le_create_connection_cancel);
4638                 return true;
4639 #endif
4640 #endif
4641             case SEND_DISCONNECT:
4642                 connection->state = SENT_DISCONNECT;
4643                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4644                 return true;
4645 
4646             default:
4647                 break;
4648         }
4649 
4650         // no further commands if connection is about to get shut down
4651         if (connection->state == SENT_DISCONNECT) continue;
4652 
4653         if (connection->authentication_flags & AUTH_FLAG_READ_RSSI){
4654             connectionClearAuthenticationFlags(connection, AUTH_FLAG_READ_RSSI);
4655             hci_send_cmd(&hci_read_rssi, connection->con_handle);
4656             return true;
4657         }
4658 
4659 #ifdef ENABLE_CLASSIC
4660 
4661         if (connection->authentication_flags & AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT){
4662             connectionClearAuthenticationFlags(connection, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
4663             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
4664             return true;
4665         }
4666 
4667         // Handling link key request requires remote supported features
4668         if (((connection->authentication_flags & AUTH_FLAG_HANDLE_LINK_KEY_REQUEST) != 0)){
4669             log_info("responding to link key request, have link key db: %u", hci_stack->link_key_db != NULL);
4670             connectionClearAuthenticationFlags(connection, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
4671 
4672             bool have_link_key = connection->link_key_type != INVALID_LINK_KEY;
4673             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(connection->link_key_type) >= connection->requested_security_level);
4674             if (have_link_key && security_level_sufficient){
4675                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &connection->link_key);
4676             } else {
4677                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
4678             }
4679             return true;
4680         }
4681 
4682         if (connection->authentication_flags & AUTH_FLAG_DENY_PIN_CODE_REQUEST){
4683             log_info("denying to pin request");
4684             connectionClearAuthenticationFlags(connection, AUTH_FLAG_DENY_PIN_CODE_REQUEST);
4685             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
4686             return true;
4687         }
4688 
4689         // security assessment requires remote features
4690         if ((connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST) != 0){
4691             connectionClearAuthenticationFlags(connection, AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
4692             hci_ssp_assess_security_on_io_cap_request(connection);
4693             // 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
4694         }
4695 
4696         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY){
4697             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
4698             // set authentication requirements:
4699             // - MITM = ssp_authentication_requirement (USER) | requested_security_level (dynamic)
4700             // - BONDING MODE: dedicated if requested, bondable otherwise. Drop bondable if not set for remote
4701             uint8_t authreq = hci_stack->ssp_authentication_requirement & 1;
4702             if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
4703                 authreq |= 1;
4704             }
4705             bool bonding = hci_stack->bondable;
4706             if (connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
4707                 // if we have received IO Cap Response, we're in responder role
4708                 bool remote_bonding = connection->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4709                 if (bonding && !remote_bonding){
4710                     log_info("Remote not bonding, dropping local flag");
4711                     bonding = false;
4712                 }
4713             }
4714             if (bonding){
4715                 if (connection->bonding_flags & BONDING_DEDICATED){
4716                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4717                 } else {
4718                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
4719                 }
4720             }
4721             uint8_t have_oob_data = 0;
4722 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4723             if (connection->classic_oob_c_192 != NULL){
4724                     have_oob_data |= 1;
4725             }
4726             if (connection->classic_oob_c_256 != NULL){
4727                 have_oob_data |= 2;
4728             }
4729 #endif
4730             hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, have_oob_data, authreq);
4731             return true;
4732         }
4733 
4734         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY) {
4735             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
4736             hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
4737             return true;
4738         }
4739 
4740 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4741         if (connection->authentication_flags & AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY){
4742             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
4743             const uint8_t zero[16] = { 0 };
4744             const uint8_t * r_192 = zero;
4745             const uint8_t * c_192 = zero;
4746             const uint8_t * r_256 = zero;
4747             const uint8_t * c_256 = zero;
4748             // verify P-256 OOB
4749             if ((connection->classic_oob_c_256 != NULL) && ((hci_stack->local_supported_commands[1] & 0x08u) != 0)) {
4750                 c_256 = connection->classic_oob_c_256;
4751                 if (connection->classic_oob_r_256 != NULL) {
4752                     r_256 = connection->classic_oob_r_256;
4753                 }
4754             }
4755             // verify P-192 OOB
4756             if ((connection->classic_oob_c_192 != NULL)) {
4757                 c_192 = connection->classic_oob_c_192;
4758                 if (connection->classic_oob_r_192 != NULL) {
4759                     r_192 = connection->classic_oob_r_192;
4760                 }
4761             }
4762 
4763             // assess security
4764             bool need_level_4 = hci_stack->gap_secure_connections_only_mode || (connection->requested_security_level == LEVEL_4);
4765             bool can_reach_level_4 = hci_remote_sc_enabled(connection) && (c_256 != NULL);
4766             if (need_level_4 && !can_reach_level_4){
4767                 log_info("Level 4 required, but not possible -> abort");
4768                 hci_pairing_complete(connection, ERROR_CODE_INSUFFICIENT_SECURITY);
4769                 // send oob negative reply
4770                 c_256 = NULL;
4771                 c_192 = NULL;
4772             }
4773 
4774             // Reply
4775             if (c_256 != zero) {
4776                 hci_send_cmd(&hci_remote_oob_extended_data_request_reply, &connection->address, c_192, r_192, c_256, r_256);
4777             } else if (c_192 != zero){
4778                 hci_send_cmd(&hci_remote_oob_data_request_reply, &connection->address, c_192, r_192);
4779             } else {
4780                 hci_stack->classic_oob_con_handle = connection->con_handle;
4781                 hci_send_cmd(&hci_remote_oob_data_request_negative_reply, &connection->address);
4782             }
4783             return true;
4784         }
4785 #endif
4786 
4787         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_REPLY){
4788             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
4789             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
4790             return true;
4791         }
4792 
4793         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY){
4794             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
4795             hci_send_cmd(&hci_user_confirmation_request_negative_reply, &connection->address);
4796             return true;
4797         }
4798 
4799         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_PASSKEY_REPLY){
4800             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
4801             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
4802             return true;
4803         }
4804 
4805         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
4806             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
4807             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
4808             connection->state = SENT_DISCONNECT;
4809             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4810             return true;
4811         }
4812 
4813         if ((connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST) && ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0)){
4814             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
4815             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
4816             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
4817             return true;
4818         }
4819 
4820         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
4821             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
4822             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
4823             return true;
4824         }
4825 
4826         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
4827             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
4828             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
4829             return true;
4830         }
4831 
4832         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
4833             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
4834             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
4835             return true;
4836         }
4837 
4838         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
4839             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
4840             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
4841             return true;
4842         }
4843 
4844         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
4845             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
4846             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
4847             return true;
4848         }
4849 #endif
4850 
4851         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
4852             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
4853 #ifdef ENABLE_CLASSIC
4854             hci_pairing_complete(connection, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_SECURITY_REASONS);
4855 #endif
4856             if (connection->state != SENT_DISCONNECT){
4857                 connection->state = SENT_DISCONNECT;
4858                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4859                 return true;
4860             }
4861         }
4862 
4863 #ifdef ENABLE_CLASSIC
4864         uint16_t sniff_min_interval;
4865         switch (connection->sniff_min_interval){
4866             case 0:
4867                 break;
4868             case 0xffff:
4869                 connection->sniff_min_interval = 0;
4870                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
4871                 return true;
4872             default:
4873                 sniff_min_interval = connection->sniff_min_interval;
4874                 connection->sniff_min_interval = 0;
4875                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
4876                 return true;
4877         }
4878 
4879         if (connection->sniff_subrating_max_latency != 0xffff){
4880             uint16_t max_latency = connection->sniff_subrating_max_latency;
4881             connection->sniff_subrating_max_latency = 0;
4882             hci_send_cmd(&hci_sniff_subrating, connection->con_handle, max_latency, connection->sniff_subrating_min_remote_timeout, connection->sniff_subrating_min_local_timeout);
4883             return true;
4884         }
4885 
4886         if (connection->qos_service_type != HCI_SERVICE_TYPE_INVALID){
4887             uint8_t service_type = (uint8_t) connection->qos_service_type;
4888             connection->qos_service_type = HCI_SERVICE_TYPE_INVALID;
4889             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);
4890             return true;
4891         }
4892 
4893         if (connection->request_role != HCI_ROLE_INVALID){
4894             hci_role_t role = connection->request_role;
4895             connection->request_role = HCI_ROLE_INVALID;
4896             hci_send_cmd(&hci_switch_role_command, connection->address, role);
4897             return true;
4898         }
4899 #endif
4900 
4901 #ifdef ENABLE_BLE
4902         switch (connection->le_con_parameter_update_state){
4903             // response to L2CAP CON PARAMETER UPDATE REQUEST
4904             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
4905                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4906                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
4907                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4908                              0x0000, 0xffff);
4909                 return true;
4910             case CON_PARAMETER_UPDATE_REPLY:
4911                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4912                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
4913                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4914                              0x0000, 0xffff);
4915                 return true;
4916             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
4917                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4918                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
4919                 return true;
4920             default:
4921                 break;
4922         }
4923         if (connection->le_phy_update_all_phys != 0xffu){
4924             uint8_t all_phys = connection->le_phy_update_all_phys;
4925             connection->le_phy_update_all_phys = 0xff;
4926             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);
4927             return true;
4928         }
4929 #endif
4930     }
4931     return false;
4932 }
4933 
4934 static void hci_run(void){
4935 
4936     bool done;
4937 
4938     // send continuation fragments first, as they block the prepared packet buffer
4939     done = hci_run_acl_fragments();
4940     if (done) return;
4941 
4942 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4943     // send host num completed packets next as they don't require num_cmd_packets > 0
4944     if (!hci_can_send_comand_packet_transport()) return;
4945     if (hci_stack->host_completed_packets){
4946         hci_host_num_completed_packets();
4947         return;
4948     }
4949 #endif
4950 
4951     if (!hci_can_send_command_packet_now()) return;
4952 
4953     // global/non-connection oriented commands
4954 
4955 
4956 #ifdef ENABLE_CLASSIC
4957     // general gap classic
4958     done = hci_run_general_gap_classic();
4959     if (done) return;
4960 #endif
4961 
4962 #ifdef ENABLE_BLE
4963     // general gap le
4964     done = hci_run_general_gap_le();
4965     if (done) return;
4966 #endif
4967 
4968     // send pending HCI commands
4969     done = hci_run_general_pending_commands();
4970     if (done) return;
4971 
4972     // stack state sub statemachines
4973     hci_connection_t * connection;
4974     switch (hci_stack->state){
4975         case HCI_STATE_INITIALIZING:
4976             hci_initializing_run();
4977             break;
4978 
4979         case HCI_STATE_HALTING:
4980 
4981             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4982             switch (hci_stack->substate){
4983                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4984                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
4985 
4986 #ifdef ENABLE_BLE
4987 #ifdef ENABLE_LE_CENTRAL
4988                     // free whitelist entries
4989                     {
4990                         btstack_linked_list_iterator_t lit;
4991                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4992                         while (btstack_linked_list_iterator_has_next(&lit)){
4993                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4994                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4995                             btstack_memory_whitelist_entry_free(entry);
4996                         }
4997                     }
4998 #endif
4999 #endif
5000                     // close all open connections
5001                     connection =  (hci_connection_t *) hci_stack->connections;
5002                     if (connection){
5003                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
5004                         if (!hci_can_send_command_packet_now()) return;
5005 
5006                         // check state
5007                         if (connection->state == SENT_DISCONNECT) return;
5008                         connection->state = SENT_DISCONNECT;
5009 
5010                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
5011 
5012                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
5013                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
5014 
5015                         // ... which would be ignored anyway as we shutdown (free) the connection now
5016                         hci_shutdown_connection(connection);
5017 
5018                         // finally, send the disconnect command
5019                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5020                         return;
5021                     }
5022 
5023                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
5024                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
5025                         log_info("HCI_STATE_HALTING: wait 50 ms");
5026                         hci_stack->substate = HCI_HALTING_W4_TIMER;
5027                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
5028                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
5029                         btstack_run_loop_add_timer(&hci_stack->timeout);
5030                         break;
5031                     }
5032 
5033                     /* fall through */
5034 
5035                 case HCI_HALTING_CLOSE:
5036                     log_info("HCI_STATE_HALTING, calling off");
5037 
5038                     // switch mode
5039                     hci_power_control_off();
5040 
5041                     log_info("HCI_STATE_HALTING, emitting state");
5042                     hci_emit_state();
5043                     log_info("HCI_STATE_HALTING, done");
5044                     break;
5045 
5046                 case HCI_HALTING_W4_TIMER:
5047                     // keep waiting
5048 
5049                     break;
5050                 default:
5051                     break;
5052             }
5053 
5054             break;
5055 
5056         case HCI_STATE_FALLING_ASLEEP:
5057             switch(hci_stack->substate) {
5058                 case HCI_FALLING_ASLEEP_DISCONNECT:
5059                     log_info("HCI_STATE_FALLING_ASLEEP");
5060                     // close all open connections
5061                     connection =  (hci_connection_t *) hci_stack->connections;
5062                     if (connection){
5063 
5064                         // send disconnect
5065                         if (!hci_can_send_command_packet_now()) return;
5066 
5067                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
5068                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5069 
5070                         // send disconnected event right away - causes higher layer connections to get closed, too.
5071                         hci_shutdown_connection(connection);
5072                         return;
5073                     }
5074 
5075                     if (hci_classic_supported()){
5076                         // disable page and inquiry scan
5077                         if (!hci_can_send_command_packet_now()) return;
5078 
5079                         log_info("HCI_STATE_HALTING, disabling inq scans");
5080                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
5081 
5082                         // continue in next sub state
5083                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
5084                         break;
5085                     }
5086 
5087                     /* fall through */
5088 
5089                 case HCI_FALLING_ASLEEP_COMPLETE:
5090                     log_info("HCI_STATE_HALTING, calling sleep");
5091                     // switch mode
5092                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
5093                     hci_emit_state();
5094                     break;
5095 
5096                 default:
5097                     break;
5098             }
5099             break;
5100 
5101         default:
5102             break;
5103     }
5104 }
5105 
5106 uint8_t hci_send_cmd_packet(uint8_t *packet, int size){
5107     // house-keeping
5108 
5109 #ifdef ENABLE_CLASSIC
5110     bd_addr_t addr;
5111     hci_connection_t * conn;
5112 #endif
5113 #ifdef ENABLE_LE_CENTRAL
5114     uint8_t initiator_filter_policy;
5115 #endif
5116 
5117     uint16_t opcode = little_endian_read_16(packet, 0);
5118     switch (opcode) {
5119         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
5120             hci_stack->loopback_mode = packet[3];
5121             break;
5122 
5123 #ifdef ENABLE_CLASSIC
5124         case HCI_OPCODE_HCI_CREATE_CONNECTION:
5125             reverse_bd_addr(&packet[3], addr);
5126             log_info("Create_connection to %s", bd_addr_to_str(addr));
5127 
5128             // CVE-2020-26555: reject outgoing connection to device with same BD ADDR
5129             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0) {
5130                 hci_emit_connection_complete(addr, 0, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR);
5131                 return ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
5132             }
5133 
5134             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5135             if (!conn) {
5136                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5137                 if (!conn) {
5138                     // notify client that alloc failed
5139                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5140                     return BTSTACK_MEMORY_ALLOC_FAILED; // packet not sent to controller
5141                 }
5142                 conn->state = SEND_CREATE_CONNECTION;
5143                 conn->role  = HCI_ROLE_MASTER;
5144             }
5145 
5146             conn->con_handle = HCI_CON_HANDLE_INVALID;
5147             conn->role = HCI_ROLE_INVALID;
5148 
5149             log_info("conn state %u", conn->state);
5150             // TODO: L2CAP should not send create connection command, instead a (new) gap function should be used
5151             switch (conn->state) {
5152                 // if connection active exists
5153                 case OPEN:
5154                     // and OPEN, emit connection complete command
5155                     hci_emit_connection_complete(addr, conn->con_handle, ERROR_CODE_SUCCESS);
5156                     // packet not sent to controller
5157                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5158                 case RECEIVED_DISCONNECTION_COMPLETE:
5159                     // create connection triggered in disconnect complete event, let's do it now
5160                     break;
5161                 case SEND_CREATE_CONNECTION:
5162                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
5163                     break;
5164                 default:
5165                     // otherwise, just ignore as it is already in the open process
5166                     // packet not sent to controller
5167                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5168             }
5169             conn->state = SENT_CREATE_CONNECTION;
5170 
5171             // track outgoing connection
5172             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
5173             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
5174             break;
5175 
5176 #if defined (ENABLE_SCO_OVER_HCI) || defined (HAVE_SCO_TRANSPORT)
5177         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
5178             // setup_synchronous_connection? Voice setting at offset 22
5179             // TODO: compare to current setting if sco connection already active
5180             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
5181             break;
5182         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
5183             // accept_synchronous_connection? Voice setting at offset 18
5184             // TODO: compare to current setting if sco connection already active
5185             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
5186             break;
5187 #endif
5188 #endif
5189 
5190 #ifdef ENABLE_BLE
5191 #ifdef ENABLE_LE_CENTRAL
5192         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
5193             // white list used?
5194             initiator_filter_policy = packet[7];
5195             switch (initiator_filter_policy) {
5196                 case 0:
5197                     // whitelist not used
5198                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
5199                     break;
5200                 case 1:
5201                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
5202                     break;
5203                 default:
5204                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
5205                     break;
5206             }
5207             // track outgoing connection
5208             hci_stack->outgoing_addr_type = (bd_addr_type_t) packet[8]; // peer addres type
5209             reverse_bd_addr( &packet[9], hci_stack->outgoing_addr); // peer address
5210             break;
5211         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
5212             hci_stack->le_connecting_state = LE_CONNECTING_CANCEL;
5213             break;
5214 #endif
5215 #endif
5216         default:
5217             break;
5218     }
5219 
5220     hci_stack->num_cmd_packets--;
5221 
5222     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
5223     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
5224     if (err != 0){
5225         return ERROR_CODE_HARDWARE_FAILURE;
5226     }
5227     return ERROR_CODE_SUCCESS;
5228 }
5229 
5230 // disconnect because of security block
5231 void hci_disconnect_security_block(hci_con_handle_t con_handle){
5232     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5233     if (!connection) return;
5234     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
5235 }
5236 
5237 
5238 // Configure Secure Simple Pairing
5239 
5240 #ifdef ENABLE_CLASSIC
5241 
5242 // enable will enable SSP during init
5243 void gap_ssp_set_enable(int enable){
5244     hci_stack->ssp_enable = enable;
5245 }
5246 
5247 static int hci_local_ssp_activated(void){
5248     return gap_ssp_supported() && hci_stack->ssp_enable;
5249 }
5250 
5251 // if set, BTstack will respond to io capability request using authentication requirement
5252 void gap_ssp_set_io_capability(int io_capability){
5253     hci_stack->ssp_io_capability = io_capability;
5254 }
5255 void gap_ssp_set_authentication_requirement(int authentication_requirement){
5256     hci_stack->ssp_authentication_requirement = authentication_requirement;
5257 }
5258 
5259 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
5260 void gap_ssp_set_auto_accept(int auto_accept){
5261     hci_stack->ssp_auto_accept = auto_accept;
5262 }
5263 
5264 void gap_secure_connections_enable(bool enable){
5265     hci_stack->secure_connections_enable = enable;
5266 }
5267 
5268 #endif
5269 
5270 // va_list part of hci_send_cmd
5271 uint8_t hci_send_cmd_va_arg(const hci_cmd_t * cmd, va_list argptr){
5272     if (!hci_can_send_command_packet_now()){
5273         log_error("hci_send_cmd called but cannot send packet now");
5274         return ERROR_CODE_COMMAND_DISALLOWED;
5275     }
5276 
5277     // for HCI INITIALIZATION
5278     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
5279     hci_stack->last_cmd_opcode = cmd->opcode;
5280 
5281     hci_reserve_packet_buffer();
5282     uint8_t * packet = hci_stack->hci_packet_buffer;
5283     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
5284     uint8_t status = hci_send_cmd_packet(packet, size);
5285 
5286     // release packet buffer on error or for synchronous transport implementations
5287     if ((status != ERROR_CODE_SUCCESS) || hci_transport_synchronous()){
5288         hci_release_packet_buffer();
5289         hci_emit_transport_packet_sent();
5290     }
5291 
5292     return status;
5293 }
5294 
5295 /**
5296  * pre: numcmds >= 0 - it's allowed to send a command to the controller
5297  */
5298 uint8_t hci_send_cmd(const hci_cmd_t * cmd, ...){
5299     va_list argptr;
5300     va_start(argptr, cmd);
5301     uint8_t status = hci_send_cmd_va_arg(cmd, argptr);
5302     va_end(argptr);
5303     return status;
5304 }
5305 
5306 // Create various non-HCI events.
5307 // TODO: generalize, use table similar to hci_create_command
5308 
5309 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
5310     // dump packet
5311     if (dump) {
5312         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
5313     }
5314 
5315     // dispatch to all event handlers
5316     btstack_linked_list_iterator_t it;
5317     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
5318     while (btstack_linked_list_iterator_has_next(&it)){
5319         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
5320         entry->callback(HCI_EVENT_PACKET, 0, event, size);
5321     }
5322 }
5323 
5324 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
5325     if (!hci_stack->acl_packet_handler) return;
5326     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
5327 }
5328 
5329 #ifdef ENABLE_CLASSIC
5330 static void hci_notify_if_sco_can_send_now(void){
5331     // notify SCO sender if waiting
5332     if (!hci_stack->sco_waiting_for_can_send_now) return;
5333     if (hci_can_send_sco_packet_now()){
5334         hci_stack->sco_waiting_for_can_send_now = 0;
5335         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
5336         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
5337         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
5338     }
5339 }
5340 
5341 // parsing end emitting has been merged to reduce code size
5342 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
5343     uint8_t event[28+GAP_INQUIRY_MAX_NAME_LEN];
5344 
5345     uint8_t * eir_data;
5346     ad_context_t context;
5347     const uint8_t * name;
5348     uint8_t         name_len;
5349 
5350     if (size < 3) return;
5351 
5352     int event_type = hci_event_packet_get_type(packet);
5353     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
5354     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
5355 
5356     switch (event_type){
5357         case HCI_EVENT_INQUIRY_RESULT:
5358         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5359             if (size != (3 + (num_responses * 14))) return;
5360             break;
5361         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5362             if (size != 257) return;
5363             if (num_responses != 1) return;
5364             break;
5365         default:
5366             return;
5367     }
5368 
5369     // event[1] is set at the end
5370     int i;
5371     for (i=0; i<num_responses;i++){
5372         memset(event, 0, sizeof(event));
5373         event[0] = GAP_EVENT_INQUIRY_RESULT;
5374         uint8_t event_size = 27;    // if name is not set by EIR
5375 
5376         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
5377         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
5378         (void)memcpy(&event[9],
5379                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
5380                      3); // class of device
5381         (void)memcpy(&event[12],
5382                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
5383                      2); // clock offset
5384 
5385         switch (event_type){
5386             case HCI_EVENT_INQUIRY_RESULT:
5387                 // 14,15,16,17 = 0, size 18
5388                 break;
5389             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5390                 event[14] = 1;
5391                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5392                 // 16,17 = 0, size 18
5393                 break;
5394             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5395                 event[14] = 1;
5396                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5397                 // EIR packets only contain a single inquiry response
5398                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
5399                 name = NULL;
5400                 // Iterate over EIR data
5401                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
5402                     uint8_t data_type    = ad_iterator_get_data_type(&context);
5403                     uint8_t data_size    = ad_iterator_get_data_len(&context);
5404                     const uint8_t * data = ad_iterator_get_data(&context);
5405                     // Prefer Complete Local Name over Shortened Local Name
5406                     switch (data_type){
5407                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
5408                             if (name) continue;
5409                             /* fall through */
5410                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
5411                             name = data;
5412                             name_len = data_size;
5413                             break;
5414                         case BLUETOOTH_DATA_TYPE_DEVICE_ID:
5415                             if (data_size != 8) break;
5416                             event[16] = 1;
5417                             memcpy(&event[17], data, 8);
5418                             break;
5419                         default:
5420                             break;
5421                     }
5422                 }
5423                 if (name){
5424                     event[25] = 1;
5425                     // truncate name if needed
5426                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
5427                     event[26] = len;
5428                     (void)memcpy(&event[27], name, len);
5429                     event_size += len;
5430                 }
5431                 break;
5432             default:
5433                 return;
5434         }
5435         event[1] = event_size - 2;
5436         hci_emit_event(event, event_size, 1);
5437     }
5438 }
5439 #endif
5440 
5441 void hci_emit_state(void){
5442     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
5443     uint8_t event[3];
5444     event[0] = BTSTACK_EVENT_STATE;
5445     event[1] = sizeof(event) - 2u;
5446     event[2] = hci_stack->state;
5447     hci_emit_event(event, sizeof(event), 1);
5448 }
5449 
5450 #ifdef ENABLE_CLASSIC
5451 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5452     uint8_t event[13];
5453     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
5454     event[1] = sizeof(event) - 2;
5455     event[2] = status;
5456     little_endian_store_16(event, 3, con_handle);
5457     reverse_bd_addr(address, &event[5]);
5458     event[11] = 1; // ACL connection
5459     event[12] = 0; // encryption disabled
5460     hci_emit_event(event, sizeof(event), 1);
5461 }
5462 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
5463     if (disable_l2cap_timeouts) return;
5464     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
5465     uint8_t event[4];
5466     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
5467     event[1] = sizeof(event) - 2;
5468     little_endian_store_16(event, 2, conn->con_handle);
5469     hci_emit_event(event, sizeof(event), 1);
5470 }
5471 #endif
5472 
5473 #ifdef ENABLE_BLE
5474 #ifdef ENABLE_LE_CENTRAL
5475 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){
5476     uint8_t event[21];
5477     event[0] = HCI_EVENT_LE_META;
5478     event[1] = sizeof(event) - 2u;
5479     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
5480     event[3] = status;
5481     little_endian_store_16(event, 4, con_handle);
5482     event[6] = 0; // TODO: role
5483     event[7] = address_type;
5484     reverse_bd_addr(address, &event[8]);
5485     little_endian_store_16(event, 14, 0); // interval
5486     little_endian_store_16(event, 16, 0); // latency
5487     little_endian_store_16(event, 18, 0); // supervision timeout
5488     event[20] = 0; // master clock accuracy
5489     hci_emit_event(event, sizeof(event), 1);
5490 }
5491 #endif
5492 #endif
5493 
5494 static void hci_emit_transport_packet_sent(void){
5495     // notify upper stack that it might be possible to send again
5496     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
5497     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
5498 }
5499 
5500 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
5501     uint8_t event[6];
5502     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
5503     event[1] = sizeof(event) - 2u;
5504     event[2] = 0; // status = OK
5505     little_endian_store_16(event, 3, con_handle);
5506     event[5] = reason;
5507     hci_emit_event(event, sizeof(event), 1);
5508 }
5509 
5510 static void hci_emit_nr_connections_changed(void){
5511     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
5512     uint8_t event[3];
5513     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
5514     event[1] = sizeof(event) - 2u;
5515     event[2] = nr_hci_connections();
5516     hci_emit_event(event, sizeof(event), 1);
5517 }
5518 
5519 static void hci_emit_hci_open_failed(void){
5520     log_info("BTSTACK_EVENT_POWERON_FAILED");
5521     uint8_t event[2];
5522     event[0] = BTSTACK_EVENT_POWERON_FAILED;
5523     event[1] = sizeof(event) - 2u;
5524     hci_emit_event(event, sizeof(event), 1);
5525 }
5526 
5527 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
5528     log_info("hci_emit_dedicated_bonding_result %u ", status);
5529     uint8_t event[9];
5530     int pos = 0;
5531     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
5532     event[pos++] = sizeof(event) - 2u;
5533     event[pos++] = status;
5534     reverse_bd_addr(address, &event[pos]);
5535     hci_emit_event(event, sizeof(event), 1);
5536 }
5537 
5538 
5539 #ifdef ENABLE_CLASSIC
5540 
5541 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
5542     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
5543     uint8_t event[5];
5544     int pos = 0;
5545     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
5546     event[pos++] = sizeof(event) - 2;
5547     little_endian_store_16(event, 2, con_handle);
5548     pos += 2;
5549     event[pos++] = level;
5550     hci_emit_event(event, sizeof(event), 1);
5551 }
5552 
5553 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
5554     if (!connection) return LEVEL_0;
5555     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
5556     // BIAS: we only consider Authenticated if the connection is already encrypted, which requires that both sides have link key
5557     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
5558     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
5559     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
5560     // LEVEL 4 always requires 128 bit encrytion key size
5561     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
5562         security_level = LEVEL_3;
5563     }
5564     return security_level;
5565 }
5566 
5567 static void hci_emit_discoverable_enabled(uint8_t enabled){
5568     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
5569     uint8_t event[3];
5570     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
5571     event[1] = sizeof(event) - 2;
5572     event[2] = enabled;
5573     hci_emit_event(event, sizeof(event), 1);
5574 }
5575 
5576 // query if remote side supports eSCO
5577 bool hci_remote_esco_supported(hci_con_handle_t con_handle){
5578     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5579     if (!connection) return false;
5580     return (connection->remote_supported_features[0] & 1) != 0;
5581 }
5582 
5583 static bool hci_ssp_supported(hci_connection_t * connection){
5584     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
5585     return (connection->bonding_flags & mask) == mask;
5586 }
5587 
5588 // query if remote side supports SSP
5589 bool hci_remote_ssp_supported(hci_con_handle_t con_handle){
5590     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5591     if (!connection) return false;
5592     return hci_ssp_supported(connection) ? 1 : 0;
5593 }
5594 
5595 bool gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
5596     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
5597 }
5598 
5599 /**
5600  * Check if remote supported features query has completed
5601  */
5602 bool hci_remote_features_available(hci_con_handle_t handle){
5603     hci_connection_t * connection = hci_connection_for_handle(handle);
5604     if (!connection) return false;
5605     return (connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0;
5606 }
5607 
5608 /**
5609  * Trigger remote supported features query
5610  */
5611 void hci_remote_features_query(hci_con_handle_t con_handle){
5612     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5613     if (!connection) return;
5614     if ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0) return;
5615     connection->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
5616     hci_run();
5617 }
5618 
5619 // GAP API
5620 /**
5621  * @bbrief enable/disable bonding. default is enabled
5622  * @praram enabled
5623  */
5624 void gap_set_bondable_mode(int enable){
5625     hci_stack->bondable = enable ? 1 : 0;
5626 }
5627 /**
5628  * @brief Get bondable mode.
5629  * @return 1 if bondable
5630  */
5631 int gap_get_bondable_mode(void){
5632     return hci_stack->bondable;
5633 }
5634 
5635 /**
5636  * @brief map link keys to security levels
5637  */
5638 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
5639     switch (link_key_type){
5640         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5641             return LEVEL_4;
5642         case COMBINATION_KEY:
5643         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5644             return LEVEL_3;
5645         default:
5646             return LEVEL_2;
5647     }
5648 }
5649 
5650 /**
5651  * @brief map link keys to secure connection yes/no
5652  */
5653 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
5654     switch (link_key_type){
5655         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5656         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5657             return 1;
5658         default:
5659             return 0;
5660     }
5661 }
5662 
5663 /**
5664  * @brief map link keys to authenticated
5665  */
5666 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
5667     switch (link_key_type){
5668         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5669         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5670             return 1;
5671         default:
5672             return 0;
5673     }
5674 }
5675 
5676 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
5677     log_info("gap_mitm_protection_required_for_security_level %u", level);
5678     return level > LEVEL_2;
5679 }
5680 
5681 /**
5682  * @brief get current security level
5683  */
5684 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
5685     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5686     if (!connection) return LEVEL_0;
5687     return gap_security_level_for_connection(connection);
5688 }
5689 
5690 /**
5691  * @brief request connection to device to
5692  * @result GAP_AUTHENTICATION_RESULT
5693  */
5694 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
5695     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5696     if (!connection){
5697         hci_emit_security_level(con_handle, LEVEL_0);
5698         return;
5699     }
5700 
5701     btstack_assert(hci_is_le_connection(connection) == false);
5702 
5703     // 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)
5704     // available on the BR/EDR physical transport require Security Mode 4, Level 4 "
5705     if (hci_stack->gap_secure_connections_only_mode && (requested_level != LEVEL_0)){
5706         requested_level = LEVEL_4;
5707     }
5708 
5709     gap_security_level_t current_level = gap_security_level(con_handle);
5710     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
5711         requested_level, connection->requested_security_level, current_level);
5712 
5713     // authentication active if authentication request was sent or planned level > 0
5714     bool authentication_active = ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) || (connection->requested_security_level > LEVEL_0);
5715     if (authentication_active){
5716         // authentication already active
5717         if (connection->requested_security_level < requested_level){
5718             // increase requested level as new level is higher
5719             // TODO: handle re-authentication when done
5720             connection->requested_security_level = requested_level;
5721         }
5722     } else {
5723         // no request active, notify if security sufficient
5724         if (requested_level <= current_level){
5725             hci_emit_security_level(con_handle, current_level);
5726             return;
5727         }
5728 
5729         // store request
5730         connection->requested_security_level = requested_level;
5731 
5732         // request remote features if not already active
5733         hci_remote_features_query(con_handle);
5734 
5735         // start to authenticate connection
5736         connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
5737         hci_run();
5738     }
5739 }
5740 
5741 /**
5742  * @brief start dedicated bonding with device. disconnect after bonding
5743  * @param device
5744  * @param request MITM protection
5745  * @result GAP_DEDICATED_BONDING_COMPLETE
5746  */
5747 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
5748 
5749     // create connection state machine
5750     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
5751 
5752     if (!connection){
5753         return BTSTACK_MEMORY_ALLOC_FAILED;
5754     }
5755 
5756     // delete linkn key
5757     gap_drop_link_key_for_bd_addr(device);
5758 
5759     // configure LEVEL_2/3, dedicated bonding
5760     connection->state = SEND_CREATE_CONNECTION;
5761     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
5762     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
5763     connection->bonding_flags = BONDING_DEDICATED;
5764 
5765     // wait for GAP Security Result and send GAP Dedicated Bonding complete
5766 
5767     // handle: connnection failure (connection complete != ok)
5768     // handle: authentication failure
5769     // handle: disconnect on done
5770 
5771     hci_run();
5772 
5773     return 0;
5774 }
5775 
5776 void gap_set_local_name(const char * local_name){
5777     hci_stack->local_name = local_name;
5778     hci_stack->gap_tasks |= GAP_TASK_SET_LOCAL_NAME;
5779     // also update EIR if not set by user
5780     if (hci_stack->eir_data == NULL){
5781         hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
5782     }
5783     hci_run();
5784 }
5785 #endif
5786 
5787 
5788 #ifdef ENABLE_BLE
5789 
5790 #ifdef ENABLE_LE_CENTRAL
5791 void gap_start_scan(void){
5792     hci_stack->le_scanning_enabled = true;
5793     hci_run();
5794 }
5795 
5796 void gap_stop_scan(void){
5797     hci_stack->le_scanning_enabled = false;
5798     hci_run();
5799 }
5800 
5801 void gap_set_scan_params(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window, uint8_t scanning_filter_policy){
5802     hci_stack->le_scan_type          = scan_type;
5803     hci_stack->le_scan_filter_policy = scanning_filter_policy;
5804     hci_stack->le_scan_interval      = scan_interval;
5805     hci_stack->le_scan_window        = scan_window;
5806     hci_stack->le_scanning_param_update = true;
5807     hci_run();
5808 }
5809 
5810 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
5811     gap_set_scan_params(scan_type, scan_interval, scan_window, 0);
5812 }
5813 
5814 uint8_t gap_connect(const bd_addr_t addr, bd_addr_type_t addr_type){
5815     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
5816     if (!conn){
5817         // disallow if le connection is already outgoing
5818         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5819             log_error("le connection already active");
5820             return ERROR_CODE_COMMAND_DISALLOWED;
5821         }
5822 
5823         log_info("gap_connect: no connection exists yet, creating context");
5824         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
5825         if (!conn){
5826             // notify client that alloc failed
5827             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5828             log_info("gap_connect: failed to alloc hci_connection_t");
5829             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
5830         }
5831 
5832         // set le connecting state
5833         if (hci_is_le_connection_type(addr_type)){
5834             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
5835         }
5836 
5837         conn->state = SEND_CREATE_CONNECTION;
5838         log_info("gap_connect: send create connection next");
5839         hci_run();
5840         return ERROR_CODE_SUCCESS;
5841     }
5842 
5843     if (!hci_is_le_connection(conn) ||
5844         (conn->state == SEND_CREATE_CONNECTION) ||
5845         (conn->state == SENT_CREATE_CONNECTION)) {
5846         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
5847         log_error("gap_connect: classic connection or connect is already being created");
5848         return GATT_CLIENT_IN_WRONG_STATE;
5849     }
5850 
5851     // check if connection was just disconnected
5852     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5853         log_info("gap_connect: send create connection (again)");
5854         conn->state = SEND_CREATE_CONNECTION;
5855         hci_run();
5856         return ERROR_CODE_SUCCESS;
5857     }
5858 
5859     log_info("gap_connect: context exists with state %u", conn->state);
5860     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
5861     hci_run();
5862     return ERROR_CODE_SUCCESS;
5863 }
5864 
5865 // @assumption: only a single outgoing LE Connection exists
5866 static hci_connection_t * gap_get_outgoing_connection(void){
5867     btstack_linked_item_t *it;
5868     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5869         hci_connection_t * conn = (hci_connection_t *) it;
5870         if (!hci_is_le_connection(conn)) continue;
5871         switch (conn->state){
5872             case SEND_CREATE_CONNECTION:
5873             case SENT_CREATE_CONNECTION:
5874             case SENT_CANCEL_CONNECTION:
5875                 return conn;
5876             default:
5877                 break;
5878         };
5879     }
5880     return NULL;
5881 }
5882 
5883 uint8_t gap_connect_cancel(void){
5884     hci_connection_t * conn = gap_get_outgoing_connection();
5885     if (!conn) return 0;
5886     switch (conn->state){
5887         case SEND_CREATE_CONNECTION:
5888             // skip sending create connection and emit event instead
5889             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5890             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5891             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5892             btstack_memory_hci_connection_free( conn );
5893             break;
5894         case SENT_CREATE_CONNECTION:
5895             // request to send cancel connection
5896             conn->state = SEND_CANCEL_CONNECTION;
5897             hci_run();
5898             break;
5899         default:
5900             break;
5901     }
5902     return 0;
5903 }
5904 #endif
5905 
5906 #ifdef ENABLE_LE_CENTRAL
5907 /**
5908  * @brief Set connection parameters for outgoing connections
5909  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5910  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5911  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5912  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5913  * @param conn_latency, default: 4
5914  * @param supervision_timeout (unit: 10ms), default: 720 ms
5915  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5916  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5917  */
5918 
5919 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5920     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5921     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5922     hci_stack->le_connection_scan_interval = conn_scan_interval;
5923     hci_stack->le_connection_scan_window = conn_scan_window;
5924     hci_stack->le_connection_interval_min = conn_interval_min;
5925     hci_stack->le_connection_interval_max = conn_interval_max;
5926     hci_stack->le_connection_latency = conn_latency;
5927     hci_stack->le_supervision_timeout = supervision_timeout;
5928     hci_stack->le_minimum_ce_length = min_ce_length;
5929     hci_stack->le_maximum_ce_length = max_ce_length;
5930 }
5931 #endif
5932 
5933 /**
5934  * @brief Updates the connection parameters for a given LE connection
5935  * @param handle
5936  * @param conn_interval_min (unit: 1.25ms)
5937  * @param conn_interval_max (unit: 1.25ms)
5938  * @param conn_latency
5939  * @param supervision_timeout (unit: 10ms)
5940  * @returns 0 if ok
5941  */
5942 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5943     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5944     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5945     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5946     connection->le_conn_interval_min = conn_interval_min;
5947     connection->le_conn_interval_max = conn_interval_max;
5948     connection->le_conn_latency = conn_latency;
5949     connection->le_supervision_timeout = supervision_timeout;
5950     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5951     hci_run();
5952     return 0;
5953 }
5954 
5955 /**
5956  * @brief Request an update of the connection parameter for a given LE connection
5957  * @param handle
5958  * @param conn_interval_min (unit: 1.25ms)
5959  * @param conn_interval_max (unit: 1.25ms)
5960  * @param conn_latency
5961  * @param supervision_timeout (unit: 10ms)
5962  * @returns 0 if ok
5963  */
5964 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5965     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5966     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5967     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5968     connection->le_conn_interval_min = conn_interval_min;
5969     connection->le_conn_interval_max = conn_interval_max;
5970     connection->le_conn_latency = conn_latency;
5971     connection->le_supervision_timeout = supervision_timeout;
5972     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5973     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5974     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5975     return 0;
5976 }
5977 
5978 #ifdef ENABLE_LE_PERIPHERAL
5979 
5980 /**
5981  * @brief Set Advertisement Data
5982  * @param advertising_data_length
5983  * @param advertising_data (max 31 octets)
5984  * @note data is not copied, pointer has to stay valid
5985  */
5986 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
5987     hci_stack->le_advertisements_data_len = advertising_data_length;
5988     hci_stack->le_advertisements_data = advertising_data;
5989     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
5990     hci_run();
5991 }
5992 
5993 /**
5994  * @brief Set Scan Response Data
5995  * @param advertising_data_length
5996  * @param advertising_data (max 31 octets)
5997  * @note data is not copied, pointer has to stay valid
5998  */
5999 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
6000     hci_stack->le_scan_response_data_len = scan_response_data_length;
6001     hci_stack->le_scan_response_data = scan_response_data;
6002     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
6003     hci_run();
6004 }
6005 
6006 /**
6007  * @brief Set Advertisement Parameters
6008  * @param adv_int_min
6009  * @param adv_int_max
6010  * @param adv_type
6011  * @param direct_address_type
6012  * @param direct_address
6013  * @param channel_map
6014  * @param filter_policy
6015  *
6016  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
6017  */
6018  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
6019     uint8_t direct_address_typ, bd_addr_t direct_address,
6020     uint8_t channel_map, uint8_t filter_policy) {
6021 
6022     hci_stack->le_advertisements_interval_min = adv_int_min;
6023     hci_stack->le_advertisements_interval_max = adv_int_max;
6024     hci_stack->le_advertisements_type = adv_type;
6025     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
6026     hci_stack->le_advertisements_channel_map = channel_map;
6027     hci_stack->le_advertisements_filter_policy = filter_policy;
6028     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
6029                  6);
6030 
6031     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS | LE_ADVERTISEMENT_TASKS_PARAMS_SET;
6032     hci_run();
6033  }
6034 
6035 /**
6036  * @brief Enable/Disable Advertisements
6037  * @param enabled
6038  */
6039 void gap_advertisements_enable(int enabled){
6040     hci_stack->le_advertisements_enabled = enabled != 0;
6041     hci_update_advertisements_enabled_for_current_roles();
6042     hci_run();
6043 }
6044 
6045 #endif
6046 
6047 void hci_le_set_own_address_type(uint8_t own_address_type){
6048     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
6049     if (own_address_type == hci_stack->le_own_addr_type) return;
6050     hci_stack->le_own_addr_type = own_address_type;
6051 
6052 #ifdef ENABLE_LE_PERIPHERAL
6053     // update advertisement parameters, too
6054     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
6055     hci_run();
6056 #endif
6057 #ifdef ENABLE_LE_CENTRAL
6058     // note: we don't update scan parameters or modify ongoing connection attempts
6059 #endif
6060 }
6061 
6062 void hci_le_random_address_set(const bd_addr_t random_address){
6063     memcpy(hci_stack->le_random_address, random_address, 6);
6064     hci_stack->le_random_address_set = true;
6065     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADDRESS;
6066     hci_run();
6067 }
6068 
6069 #endif
6070 
6071 uint8_t gap_disconnect(hci_con_handle_t handle){
6072     hci_connection_t * conn = hci_connection_for_handle(handle);
6073     if (!conn){
6074         hci_emit_disconnection_complete(handle, 0);
6075         return 0;
6076     }
6077     // ignore if already disconnected
6078     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
6079         return 0;
6080     }
6081     conn->state = SEND_DISCONNECT;
6082     hci_run();
6083     return 0;
6084 }
6085 
6086 int gap_read_rssi(hci_con_handle_t con_handle){
6087     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6088     if (hci_connection == NULL) return 0;
6089     connectionSetAuthenticationFlags(hci_connection, AUTH_FLAG_READ_RSSI);
6090     hci_run();
6091     return 1;
6092 }
6093 
6094 /**
6095  * @brief Get connection type
6096  * @param con_handle
6097  * @result connection_type
6098  */
6099 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
6100     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6101     if (!conn) return GAP_CONNECTION_INVALID;
6102     switch (conn->address_type){
6103         case BD_ADDR_TYPE_LE_PUBLIC:
6104         case BD_ADDR_TYPE_LE_RANDOM:
6105             return GAP_CONNECTION_LE;
6106         case BD_ADDR_TYPE_SCO:
6107             return GAP_CONNECTION_SCO;
6108         case BD_ADDR_TYPE_ACL:
6109             return GAP_CONNECTION_ACL;
6110         default:
6111             return GAP_CONNECTION_INVALID;
6112     }
6113 }
6114 
6115 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
6116     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6117     if (!conn) return HCI_ROLE_INVALID;
6118     return (hci_role_t) conn->role;
6119 }
6120 
6121 
6122 #ifdef ENABLE_CLASSIC
6123 uint8_t gap_request_role(const bd_addr_t addr, hci_role_t role){
6124     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6125     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6126     conn->request_role = role;
6127     hci_run();
6128     return ERROR_CODE_SUCCESS;
6129 }
6130 #endif
6131 
6132 #ifdef ENABLE_BLE
6133 
6134 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){
6135     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6136     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6137 
6138     conn->le_phy_update_all_phys    = all_phys;
6139     conn->le_phy_update_tx_phys     = tx_phys;
6140     conn->le_phy_update_rx_phys     = rx_phys;
6141     conn->le_phy_update_phy_options = phy_options;
6142 
6143     hci_run();
6144 
6145     return 0;
6146 }
6147 
6148 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6149     // check if already in list
6150     btstack_linked_list_iterator_t it;
6151     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6152     while (btstack_linked_list_iterator_has_next(&it)) {
6153         whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&it);
6154         if (entry->address_type != address_type) {
6155             continue;
6156         }
6157         if (memcmp(entry->address, address, 6) != 0) {
6158             continue;
6159         }
6160 		// disallow if already scheduled to add
6161 		if ((entry->state & LE_WHITELIST_ADD_TO_CONTROLLER) != 0){
6162 			return ERROR_CODE_COMMAND_DISALLOWED;
6163 		}
6164 		// still on controller, but scheduled to remove -> re-add
6165 		entry->state |= LE_WHITELIST_ADD_TO_CONTROLLER;
6166 		return ERROR_CODE_SUCCESS;
6167     }
6168     // alloc and add to list
6169     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
6170     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
6171     entry->address_type = address_type;
6172     (void)memcpy(entry->address, address, 6);
6173     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
6174     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
6175     return ERROR_CODE_SUCCESS;
6176 }
6177 
6178 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6179     btstack_linked_list_iterator_t it;
6180     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6181     while (btstack_linked_list_iterator_has_next(&it)){
6182         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6183         if (entry->address_type != address_type) {
6184             continue;
6185         }
6186         if (memcmp(entry->address, address, 6) != 0) {
6187             continue;
6188         }
6189         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6190             // remove from controller if already present
6191             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6192         }  else {
6193             // directly remove entry from whitelist
6194             btstack_linked_list_iterator_remove(&it);
6195             btstack_memory_whitelist_entry_free(entry);
6196         }
6197         return ERROR_CODE_SUCCESS;
6198     }
6199     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6200 }
6201 
6202 static void hci_whitelist_clear(void){
6203     btstack_linked_list_iterator_t it;
6204     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6205     while (btstack_linked_list_iterator_has_next(&it)){
6206         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6207         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6208             // remove from controller if already present
6209             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6210             continue;
6211         }
6212         // directly remove entry from whitelist
6213         btstack_linked_list_iterator_remove(&it);
6214         btstack_memory_whitelist_entry_free(entry);
6215     }
6216 }
6217 
6218 /**
6219  * @brief Clear Whitelist
6220  * @returns 0 if ok
6221  */
6222 uint8_t gap_whitelist_clear(void){
6223     hci_whitelist_clear();
6224     hci_run();
6225     return ERROR_CODE_SUCCESS;
6226 }
6227 
6228 /**
6229  * @brief Add Device to Whitelist
6230  * @param address_typ
6231  * @param address
6232  * @returns 0 if ok
6233  */
6234 uint8_t gap_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6235     uint8_t status = hci_whitelist_add(address_type, address);
6236     if (status){
6237         return status;
6238     }
6239     hci_run();
6240     return ERROR_CODE_SUCCESS;
6241 }
6242 
6243 /**
6244  * @brief Remove Device from Whitelist
6245  * @param address_typ
6246  * @param address
6247  * @returns 0 if ok
6248  */
6249 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6250     uint8_t status = hci_whitelist_remove(address_type, address);
6251     if (status){
6252         return status;
6253     }
6254     hci_run();
6255     return ERROR_CODE_SUCCESS;
6256 }
6257 
6258 #ifdef ENABLE_LE_CENTRAL
6259 /**
6260  *  @brief Connect with Whitelist
6261  *  @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
6262  *  @returns - if ok
6263  */
6264 uint8_t gap_connect_with_whitelist(void){
6265     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
6266         return ERROR_CODE_COMMAND_DISALLOWED;
6267     }
6268     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6269     hci_run();
6270     return ERROR_CODE_SUCCESS;
6271 }
6272 
6273 /**
6274  * @brief Auto Connection Establishment - Start Connecting to device
6275  * @param address_typ
6276  * @param address
6277  * @returns 0 if ok
6278  */
6279 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, const bd_addr_t address){
6280     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6281         return ERROR_CODE_COMMAND_DISALLOWED;
6282     }
6283 
6284     uint8_t status = hci_whitelist_add(address_type, address);
6285     if (status == BTSTACK_MEMORY_ALLOC_FAILED) {
6286         return status;
6287     }
6288 
6289     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6290 
6291     hci_run();
6292     return ERROR_CODE_SUCCESS;
6293 }
6294 
6295 /**
6296  * @brief Auto Connection Establishment - Stop Connecting to device
6297  * @param address_typ
6298  * @param address
6299  * @returns 0 if ok
6300  */
6301 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, const bd_addr_t address){
6302     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6303         return ERROR_CODE_COMMAND_DISALLOWED;
6304     }
6305 
6306     hci_whitelist_remove(address_type, address);
6307     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
6308         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6309     }
6310     hci_run();
6311     return 0;
6312 }
6313 
6314 /**
6315  * @brief Auto Connection Establishment - Stop everything
6316  * @note  Convenience function to stop all active auto connection attempts
6317  */
6318 uint8_t gap_auto_connection_stop_all(void){
6319     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
6320         return ERROR_CODE_COMMAND_DISALLOWED;
6321     }
6322     hci_whitelist_clear();
6323     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6324     hci_run();
6325     return ERROR_CODE_SUCCESS;
6326 }
6327 
6328 uint16_t gap_le_connection_interval(hci_con_handle_t con_handle){
6329     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6330     if (!conn) return 0;
6331     return conn->le_connection_interval;
6332 }
6333 #endif
6334 #endif
6335 
6336 #ifdef ENABLE_CLASSIC
6337 /**
6338  * @brief Set Extended Inquiry Response data
6339  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
6340  * @note has to be done before stack starts up
6341  */
6342 void gap_set_extended_inquiry_response(const uint8_t * data){
6343     hci_stack->eir_data = data;
6344     hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
6345     hci_run();
6346 }
6347 
6348 /**
6349  * @brief Start GAP Classic Inquiry
6350  * @param duration in 1.28s units
6351  * @return 0 if ok
6352  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
6353  */
6354 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
6355     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
6356     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6357     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
6358         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
6359     }
6360     hci_stack->inquiry_state = duration_in_1280ms_units;
6361     hci_run();
6362     return 0;
6363 }
6364 
6365 /**
6366  * @brief Stop GAP Classic Inquiry
6367  * @returns 0 if ok
6368  */
6369 int gap_inquiry_stop(void){
6370     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
6371         // emit inquiry complete event, before it even started
6372         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
6373         hci_emit_event(event, sizeof(event), 1);
6374         return 0;
6375     }
6376     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
6377     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
6378     hci_run();
6379     return 0;
6380 }
6381 
6382 void gap_inquiry_set_lap(uint32_t lap){
6383     hci_stack->inquiry_lap = lap;
6384 }
6385 
6386 
6387 /**
6388  * @brief Remote Name Request
6389  * @param addr
6390  * @param page_scan_repetition_mode
6391  * @param clock_offset only used when bit 15 is set
6392  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
6393  */
6394 int gap_remote_name_request(const bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
6395     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6396     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
6397     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
6398     hci_stack->remote_name_clock_offset = clock_offset;
6399     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
6400     hci_run();
6401     return 0;
6402 }
6403 
6404 static int gap_pairing_set_state_and_run(const bd_addr_t addr, uint8_t state){
6405     hci_stack->gap_pairing_state = state;
6406     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
6407     hci_run();
6408     return 0;
6409 }
6410 
6411 /**
6412  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
6413  * @param addr
6414  * @param pin_data
6415  * @param pin_len
6416  * @return 0 if ok
6417  */
6418 int gap_pin_code_response_binary(const bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
6419     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6420     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
6421     hci_stack->gap_pairing_pin_len = pin_len;
6422     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
6423 }
6424 
6425 /**
6426  * @brief Legacy Pairing Pin Code Response
6427  * @param addr
6428  * @param pin
6429  * @return 0 if ok
6430  */
6431 int gap_pin_code_response(const bd_addr_t addr, const char * pin){
6432     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
6433 }
6434 
6435 /**
6436  * @brief Abort Legacy Pairing
6437  * @param addr
6438  * @param pin
6439  * @return 0 if ok
6440  */
6441 int gap_pin_code_negative(bd_addr_t addr){
6442     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6443     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
6444 }
6445 
6446 /**
6447  * @brief SSP Passkey Response
6448  * @param addr
6449  * @param passkey
6450  * @return 0 if ok
6451  */
6452 int gap_ssp_passkey_response(const bd_addr_t addr, uint32_t passkey){
6453     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6454     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
6455     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
6456 }
6457 
6458 /**
6459  * @brief Abort SSP Passkey Entry/Pairing
6460  * @param addr
6461  * @param pin
6462  * @return 0 if ok
6463  */
6464 int gap_ssp_passkey_negative(const bd_addr_t addr){
6465     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6466     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
6467 }
6468 
6469 /**
6470  * @brief Accept SSP Numeric Comparison
6471  * @param addr
6472  * @param passkey
6473  * @return 0 if ok
6474  */
6475 int gap_ssp_confirmation_response(const bd_addr_t addr){
6476     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6477     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
6478 }
6479 
6480 /**
6481  * @brief Abort SSP Numeric Comparison/Pairing
6482  * @param addr
6483  * @param pin
6484  * @return 0 if ok
6485  */
6486 int gap_ssp_confirmation_negative(const bd_addr_t addr){
6487     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6488     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
6489 }
6490 
6491 #if defined(ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY) || defined(ENABLE_EXPLICIT_LINK_KEY_REPLY)
6492 static uint8_t gap_set_auth_flag_and_run(const bd_addr_t addr, hci_authentication_flags_t flag){
6493     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6494     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6495     connectionSetAuthenticationFlags(conn, flag);
6496     hci_run();
6497     return ERROR_CODE_SUCCESS;
6498 }
6499 #endif
6500 
6501 #ifdef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
6502 uint8_t gap_ssp_io_capabilities_response(const bd_addr_t addr){
6503     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
6504 }
6505 
6506 uint8_t gap_ssp_io_capabilities_negative(const bd_addr_t addr){
6507     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
6508 }
6509 #endif
6510 
6511 #ifdef ENABLE_CLASSIC_PAIRING_OOB
6512 /**
6513  * @brief Report Remote OOB Data
6514  * @param bd_addr
6515  * @param c_192 Simple Pairing Hash C derived from P-192 public key
6516  * @param r_192 Simple Pairing Randomizer derived from P-192 public key
6517  * @param c_256 Simple Pairing Hash C derived from P-256 public key
6518  * @param r_256 Simple Pairing Randomizer derived from P-256 public key
6519  */
6520 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){
6521     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6522     if (connection == NULL) {
6523         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6524     }
6525     connection->classic_oob_c_192 = c_192;
6526     connection->classic_oob_r_192 = r_192;
6527 
6528     // ignore P-256 if not supported by us
6529     if (hci_stack->secure_connections_active){
6530         connection->classic_oob_c_256 = c_256;
6531         connection->classic_oob_r_256 = r_256;
6532     }
6533 
6534     return ERROR_CODE_SUCCESS;
6535 }
6536 /**
6537  * @brief Generate new OOB data
6538  * @note OOB data will be provided in GAP_EVENT_LOCAL_OOB_DATA and be used in future pairing procedures
6539  */
6540 void gap_ssp_generate_oob_data(void){
6541     hci_stack->classic_read_local_oob_data = true;
6542     hci_run();
6543 }
6544 
6545 #endif
6546 
6547 #ifdef ENABLE_EXPLICIT_LINK_KEY_REPLY
6548 uint8_t gap_send_link_key_response(const bd_addr_t addr, link_key_t link_key, link_key_type_t type){
6549     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6550     if (connection == NULL) {
6551         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6552     }
6553 
6554     memcpy(connection->link_key, link_key, sizeof(link_key_t));
6555     connection->link_key_type = type;
6556 
6557     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
6558 }
6559 
6560 #endif // ENABLE_EXPLICIT_LINK_KEY_REPLY
6561 /**
6562  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
6563  * @param inquiry_mode see bluetooth_defines.h
6564  */
6565 void hci_set_inquiry_mode(inquiry_mode_t inquiry_mode){
6566     hci_stack->inquiry_mode = inquiry_mode;
6567 }
6568 
6569 /**
6570  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
6571  */
6572 void hci_set_sco_voice_setting(uint16_t voice_setting){
6573     hci_stack->sco_voice_setting = voice_setting;
6574 }
6575 
6576 /**
6577  * @brief Get SCO Voice Setting
6578  * @return current voice setting
6579  */
6580 uint16_t hci_get_sco_voice_setting(void){
6581     return hci_stack->sco_voice_setting;
6582 }
6583 
6584 static int hci_have_usb_transport(void){
6585     if (!hci_stack->hci_transport) return 0;
6586     const char * transport_name = hci_stack->hci_transport->name;
6587     if (!transport_name) return 0;
6588     return (transport_name[0] == 'H') && (transport_name[1] == '2');
6589 }
6590 
6591 /** @brief Get SCO packet length for current SCO Voice setting
6592  *  @note  Using SCO packets of the exact length is required for USB transfer
6593  *  @return Length of SCO packets in bytes (not audio frames)
6594  */
6595 uint16_t hci_get_sco_packet_length(void){
6596     uint16_t sco_packet_length = 0;
6597 
6598 #ifdef ENABLE_SCO_OVER_HCI
6599     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6600     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6601 
6602     if (hci_have_usb_transport()){
6603         // see Core Spec for H2 USB Transfer.
6604         // 3 byte SCO header + 24 bytes per connection
6605         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
6606         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
6607     } else {
6608         // 3 byte SCO header + SCO packet size over the air (60 bytes)
6609         sco_packet_length = 3 + 60 * multiplier;
6610         // assert that it still fits inside an SCO buffer
6611         if (sco_packet_length > hci_stack->sco_data_packet_length){
6612             sco_packet_length = 3 + 60;
6613         }
6614     }
6615 #endif
6616 
6617 #ifdef HAVE_SCO_TRANSPORT
6618     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6619     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6620     sco_packet_length = 3 + 60 * multiplier;
6621 #endif
6622     return sco_packet_length;
6623 }
6624 
6625 /**
6626 * @brief Sets the master/slave policy
6627 * @param policy (0: attempt to become master, 1: let connecting device decide)
6628 */
6629 void hci_set_master_slave_policy(uint8_t policy){
6630     hci_stack->master_slave_policy = policy;
6631 }
6632 
6633 #endif
6634 
6635 HCI_STATE hci_get_state(void){
6636     return hci_stack->state;
6637 }
6638 
6639 #ifdef ENABLE_CLASSIC
6640 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr, hci_link_type_t link_type)){
6641     hci_stack->gap_classic_accept_callback = accept_callback;
6642 }
6643 #endif
6644 
6645 /**
6646  * @brief Set callback for Bluetooth Hardware Error
6647  */
6648 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
6649     hci_stack->hardware_error_callback = fn;
6650 }
6651 
6652 void hci_disconnect_all(void){
6653     btstack_linked_list_iterator_t it;
6654     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6655     while (btstack_linked_list_iterator_has_next(&it)){
6656         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6657         if (con->state == SENT_DISCONNECT) continue;
6658         con->state = SEND_DISCONNECT;
6659     }
6660     hci_run();
6661 }
6662 
6663 uint16_t hci_get_manufacturer(void){
6664     return hci_stack->manufacturer;
6665 }
6666 
6667 #ifdef ENABLE_BLE
6668 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
6669     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
6670     if (!hci_con) return NULL;
6671     return &hci_con->sm_connection;
6672 }
6673 
6674 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
6675 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
6676 #endif
6677 
6678 int gap_encryption_key_size(hci_con_handle_t con_handle){
6679     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6680     if (hci_connection == NULL) return 0;
6681     if (hci_is_le_connection(hci_connection)){
6682 #ifdef ENABLE_BLE
6683         sm_connection_t * sm_conn = &hci_connection->sm_connection;
6684         if (sm_conn->sm_connection_encrypted) {
6685             return sm_conn->sm_actual_encryption_key_size;
6686         }
6687 #endif
6688     } else {
6689 #ifdef ENABLE_CLASSIC
6690         if ((hci_connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED)){
6691             return hci_connection->encryption_key_size;
6692         }
6693 #endif
6694     }
6695     return 0;
6696 }
6697 
6698 int gap_authenticated(hci_con_handle_t con_handle){
6699     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6700     if (hci_connection == NULL) return 0;
6701 
6702     switch (hci_connection->address_type){
6703 #ifdef ENABLE_BLE
6704         case BD_ADDR_TYPE_LE_PUBLIC:
6705         case BD_ADDR_TYPE_LE_RANDOM:
6706             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6707             return hci_connection->sm_connection.sm_connection_authenticated;
6708 #endif
6709 #ifdef ENABLE_CLASSIC
6710         case BD_ADDR_TYPE_SCO:
6711         case BD_ADDR_TYPE_ACL:
6712             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
6713 #endif
6714         default:
6715             return 0;
6716     }
6717 }
6718 
6719 int gap_secure_connection(hci_con_handle_t con_handle){
6720     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6721     if (hci_connection == NULL) return 0;
6722 
6723     switch (hci_connection->address_type){
6724 #ifdef ENABLE_BLE
6725         case BD_ADDR_TYPE_LE_PUBLIC:
6726         case BD_ADDR_TYPE_LE_RANDOM:
6727             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6728             return hci_connection->sm_connection.sm_connection_sc;
6729 #endif
6730 #ifdef ENABLE_CLASSIC
6731         case BD_ADDR_TYPE_SCO:
6732         case BD_ADDR_TYPE_ACL:
6733             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
6734 #endif
6735         default:
6736             return 0;
6737     }
6738 }
6739 
6740 bool gap_bonded(hci_con_handle_t con_handle){
6741 	hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6742 	if (hci_connection == NULL) return 0;
6743 
6744 #ifdef ENABLE_CLASSIC
6745 	link_key_t link_key;
6746 	link_key_type_t link_key_type;
6747 #endif
6748 	switch (hci_connection->address_type){
6749 #ifdef ENABLE_BLE
6750 		case BD_ADDR_TYPE_LE_PUBLIC:
6751 		case BD_ADDR_TYPE_LE_RANDOM:
6752 			return hci_connection->sm_connection.sm_le_db_index >= 0;
6753 #endif
6754 #ifdef ENABLE_CLASSIC
6755 		case BD_ADDR_TYPE_SCO:
6756 		case BD_ADDR_TYPE_ACL:
6757 			return hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(hci_connection->address, link_key, &link_key_type);
6758 #endif
6759 		default:
6760 			return false;
6761 	}
6762 }
6763 
6764 #ifdef ENABLE_BLE
6765 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
6766     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
6767     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
6768     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
6769     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
6770     return sm_conn->sm_connection_authorization_state;
6771 }
6772 #endif
6773 
6774 #ifdef ENABLE_CLASSIC
6775 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){
6776     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6777     if (!conn) return GAP_CONNECTION_INVALID;
6778     conn->sniff_min_interval = sniff_min_interval;
6779     conn->sniff_max_interval = sniff_max_interval;
6780     conn->sniff_attempt = sniff_attempt;
6781     conn->sniff_timeout = sniff_timeout;
6782     hci_run();
6783     return 0;
6784 }
6785 
6786 /**
6787  * @brief Exit Sniff mode
6788  * @param con_handle
6789  @ @return 0 if ok
6790  */
6791 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
6792     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6793     if (!conn) return GAP_CONNECTION_INVALID;
6794     conn->sniff_min_interval = 0xffff;
6795     hci_run();
6796     return 0;
6797 }
6798 
6799 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){
6800     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6801     if (!conn) return GAP_CONNECTION_INVALID;
6802     conn->sniff_subrating_max_latency = max_latency;
6803     conn->sniff_subrating_min_remote_timeout = min_remote_timeout;
6804     conn->sniff_subrating_min_local_timeout = min_local_timeout;
6805     hci_run();
6806     return ERROR_CODE_SUCCESS;
6807 }
6808 
6809 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){
6810     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6811     if (!conn) return GAP_CONNECTION_INVALID;
6812     conn->qos_service_type = service_type;
6813     conn->qos_token_rate = token_rate;
6814     conn->qos_peak_bandwidth = peak_bandwidth;
6815     conn->qos_latency = latency;
6816     conn->qos_delay_variation = delay_variation;
6817     hci_run();
6818     return ERROR_CODE_SUCCESS;
6819 }
6820 
6821 void gap_set_page_scan_activity(uint16_t page_scan_interval, uint16_t page_scan_window){
6822     hci_stack->new_page_scan_interval = page_scan_interval;
6823     hci_stack->new_page_scan_window = page_scan_window;
6824     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
6825     hci_run();
6826 }
6827 
6828 void gap_set_page_scan_type(page_scan_type_t page_scan_type){
6829     hci_stack->new_page_scan_type = (uint8_t) page_scan_type;
6830     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_TYPE;
6831     hci_run();
6832 }
6833 
6834 #endif
6835 
6836 void hci_halting_defer(void){
6837     if (hci_stack->state != HCI_STATE_HALTING) return;
6838     switch (hci_stack->substate){
6839         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
6840         case HCI_HALTING_CLOSE:
6841             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
6842             break;
6843         default:
6844             break;
6845     }
6846 }
6847 
6848 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
6849 void hci_load_le_device_db_entry_into_resolving_list(uint16_t le_device_db_index){
6850     if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6851     if (le_device_db_index >= le_device_db_max_count()) return;
6852     uint8_t offset = le_device_db_index >> 3;
6853     uint8_t mask = 1 << (le_device_db_index & 7);
6854     hci_stack->le_resolving_list_add_entries[offset] |= mask;
6855     if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6856     	// note: go back to remove entries, otherwise, a remove + add will skip the add
6857         hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6858     }
6859 }
6860 
6861 void hci_remove_le_device_db_entry_from_resolving_list(uint16_t le_device_db_index){
6862 	if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6863 	if (le_device_db_index >= le_device_db_max_count()) return;
6864 	uint8_t offset = le_device_db_index >> 3;
6865 	uint8_t mask = 1 << (le_device_db_index & 7);
6866 	hci_stack->le_resolving_list_remove_entries[offset] |= mask;
6867 	if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6868 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6869 	}
6870 }
6871 
6872 uint8_t gap_load_resolving_list_from_le_device_db(void){
6873 	if ((hci_stack->local_supported_commands[1] & (1 << 2)) == 0) {
6874 		return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
6875 	}
6876 	if (hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION){
6877 		// restart le resolving list update
6878 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
6879 	}
6880 	return ERROR_CODE_SUCCESS;
6881 }
6882 #endif
6883 
6884 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
6885 void hci_setup_test_connections_fuzz(void){
6886     hci_connection_t * conn;
6887 
6888     // default address: 66:55:44:33:00:01
6889     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
6890 
6891     // setup Controller info
6892     hci_stack->num_cmd_packets = 255;
6893     hci_stack->acl_packets_total_num = 255;
6894 
6895     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
6896     addr[5] = 0x01;
6897     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6898     conn->con_handle = addr[5];
6899     conn->role  = HCI_ROLE_SLAVE;
6900     conn->state = RECEIVED_CONNECTION_REQUEST;
6901     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6902 
6903     // setup incoming Classic SCO connection with con handle 0x0002
6904     addr[5] = 0x02;
6905     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6906     conn->con_handle = addr[5];
6907     conn->role  = HCI_ROLE_SLAVE;
6908     conn->state = RECEIVED_CONNECTION_REQUEST;
6909     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6910 
6911     // setup ready Classic ACL connection with con handle 0x0003
6912     addr[5] = 0x03;
6913     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6914     conn->con_handle = addr[5];
6915     conn->role  = HCI_ROLE_SLAVE;
6916     conn->state = OPEN;
6917     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6918 
6919     // setup ready Classic SCO connection with con handle 0x0004
6920     addr[5] = 0x04;
6921     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6922     conn->con_handle = addr[5];
6923     conn->role  = HCI_ROLE_SLAVE;
6924     conn->state = OPEN;
6925     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6926 
6927     // setup ready LE ACL connection with con handle 0x005 and public address
6928     addr[5] = 0x05;
6929     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
6930     conn->con_handle = addr[5];
6931     conn->role  = HCI_ROLE_SLAVE;
6932     conn->state = OPEN;
6933     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6934     conn->sm_connection.sm_connection_encrypted = 1;
6935 }
6936 
6937 void hci_free_connections_fuzz(void){
6938     btstack_linked_list_iterator_t it;
6939     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6940     while (btstack_linked_list_iterator_has_next(&it)){
6941         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6942         btstack_linked_list_iterator_remove(&it);
6943         btstack_memory_hci_connection_free(con);
6944     }
6945 }
6946 void hci_simulate_working_fuzz(void){
6947     hci_init_done();
6948     hci_stack->num_cmd_packets = 255;
6949 }
6950 #endif
6951