xref: /btstack/src/hci.c (revision 4783d25609a5032739e1b6e67d2236f2d80f2100)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hci.c"
39 
40 /*
41  *  hci.c
42  *
43  *  Created by Matthias Ringwald on 4/29/09.
44  *
45  */
46 
47 #include "btstack_config.h"
48 
49 
50 #ifdef ENABLE_CLASSIC
51 #ifdef HAVE_EMBEDDED_TICK
52 #include "btstack_run_loop_embedded.h"
53 #endif
54 #endif
55 
56 #ifdef HAVE_PLATFORM_IPHONE_OS
57 #include "../port/ios/src/btstack_control_iphone.h"
58 #endif
59 
60 #ifdef ENABLE_BLE
61 #include "gap.h"
62 #endif
63 
64 #include <stdarg.h>
65 #include <string.h>
66 #include <stdio.h>
67 #include <inttypes.h>
68 
69 #include "btstack_debug.h"
70 #include "btstack_event.h"
71 #include "btstack_linked_list.h"
72 #include "btstack_memory.h"
73 #include "bluetooth_company_id.h"
74 #include "bluetooth_data_types.h"
75 #include "gap.h"
76 #include "hci.h"
77 #include "hci_cmd.h"
78 #include "hci_dump.h"
79 #include "ad_parser.h"
80 
81 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
82 #ifndef HCI_HOST_ACL_PACKET_NUM
83 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
84 #endif
85 #ifndef HCI_HOST_ACL_PACKET_LEN
86 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
87 #endif
88 #ifndef HCI_HOST_SCO_PACKET_NUM
89 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
90 #endif
91 #ifndef HCI_HOST_SCO_PACKET_LEN
92 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
93 #endif
94 #endif
95 
96 #define HCI_CONNECTION_TIMEOUT_MS 10000
97 
98 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
99 #define HCI_RESET_RESEND_TIMEOUT_MS 200
100 #endif
101 
102 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
103 #ifndef GAP_INQUIRY_MAX_NAME_LEN
104 #define GAP_INQUIRY_MAX_NAME_LEN 32
105 #endif
106 
107 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
108 #define GAP_INQUIRY_DURATION_MIN 0x01
109 #define GAP_INQUIRY_DURATION_MAX 0x30
110 #define GAP_INQUIRY_STATE_ACTIVE 0x80
111 #define GAP_INQUIRY_STATE_IDLE 0
112 #define GAP_INQUIRY_STATE_W2_CANCEL 0x81
113 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x82
114 
115 // GAP Remote Name Request
116 #define GAP_REMOTE_NAME_STATE_IDLE 0
117 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
118 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
119 
120 // GAP Pairing
121 #define GAP_PAIRING_STATE_IDLE                       0
122 #define GAP_PAIRING_STATE_SEND_PIN                   1
123 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
124 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
125 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
126 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
127 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
128 
129 
130 // prototypes
131 #ifdef ENABLE_CLASSIC
132 static void hci_update_scan_enable(void);
133 static void hci_emit_discoverable_enabled(uint8_t enabled);
134 static int  hci_local_ssp_activated(void);
135 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
136 static bool hci_ssp_supported(hci_connection_t * connection);
137 static void hci_notify_if_sco_can_send_now(void);
138 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
139 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
140 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
141 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
142 static void hci_connection_timestamp(hci_connection_t *connection);
143 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
144 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
145 #endif
146 
147 static int  hci_power_control_on(void);
148 static void hci_power_control_off(void);
149 static void hci_state_reset(void);
150 static void hci_emit_transport_packet_sent(void);
151 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
152 static void hci_emit_nr_connections_changed(void);
153 static void hci_emit_hci_open_failed(void);
154 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
155 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
156 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
157 static void hci_run(void);
158 static int  hci_is_le_connection(hci_connection_t * connection);
159 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
160 
161 #ifdef ENABLE_CLASSIC
162 static int hci_have_usb_transport(void);
163 #endif
164 
165 #ifdef ENABLE_BLE
166 #ifdef ENABLE_LE_CENTRAL
167 // called from test/ble_client/advertising_data_parser.c
168 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
169 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address);
170 static hci_connection_t * gap_get_outgoing_connection(void);
171 #endif
172 #endif
173 
174 // the STACK is here
175 #ifndef HAVE_MALLOC
176 static hci_stack_t   hci_stack_static;
177 #endif
178 static hci_stack_t * hci_stack = NULL;
179 
180 #ifdef ENABLE_CLASSIC
181 // default name
182 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
183 
184 // test helper
185 static uint8_t disable_l2cap_timeouts = 0;
186 #endif
187 
188 /**
189  * create connection for given address
190  *
191  * @return connection OR NULL, if no memory left
192  */
193 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
194     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
195     hci_connection_t * conn = btstack_memory_hci_connection_get();
196     if (!conn) return NULL;
197     bd_addr_copy(conn->address, addr);
198     conn->address_type = addr_type;
199     conn->con_handle = 0xffff;
200     conn->authentication_flags = AUTH_FLAGS_NONE;
201     conn->bonding_flags = 0;
202     conn->requested_security_level = LEVEL_0;
203 #ifdef ENABLE_CLASSIC
204     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     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
220     return conn;
221 }
222 
223 
224 /**
225  * get le connection parameter range
226 *
227  * @return le connection parameter range struct
228  */
229 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
230     *range = hci_stack->le_connection_parameter_range;
231 }
232 
233 /**
234  * set le connection parameter range
235  *
236  */
237 
238 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
239     hci_stack->le_connection_parameter_range = *range;
240 }
241 
242 /**
243  * @brief Test if connection parameters are inside in existing rage
244  * @param conn_interval_min (unit: 1.25ms)
245  * @param conn_interval_max (unit: 1.25ms)
246  * @param conn_latency
247  * @param supervision_timeout (unit: 10ms)
248  * @returns 1 if included
249  */
250 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){
251     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
252     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
253 
254     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
255     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
256 
257     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
258     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
259 
260     return 1;
261 }
262 
263 /**
264  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
265  * @note: default: 1
266  * @param max_peripheral_connections
267  */
268 #ifdef ENABLE_LE_PERIPHERAL
269 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
270     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
271 }
272 #endif
273 
274 /**
275  * get hci connections iterator
276  *
277  * @return hci connections iterator
278  */
279 
280 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
281     btstack_linked_list_iterator_init(it, &hci_stack->connections);
282 }
283 
284 /**
285  * get connection for a given handle
286  *
287  * @return connection OR NULL, if not found
288  */
289 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
290     btstack_linked_list_iterator_t it;
291     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
292     while (btstack_linked_list_iterator_has_next(&it)){
293         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
294         if ( item->con_handle == con_handle ) {
295             return item;
296         }
297     }
298     return NULL;
299 }
300 
301 /**
302  * get connection for given address
303  *
304  * @return connection OR NULL, if not found
305  */
306 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t  addr, bd_addr_type_t addr_type){
307     btstack_linked_list_iterator_t it;
308     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
309     while (btstack_linked_list_iterator_has_next(&it)){
310         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
311         if (connection->address_type != addr_type)  continue;
312         if (memcmp(addr, connection->address, 6) != 0) continue;
313         return connection;
314     }
315     return NULL;
316 }
317 
318 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
319     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
320 }
321 
322 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
323     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
324 }
325 
326 #ifdef ENABLE_CLASSIC
327 
328 #ifdef ENABLE_SCO_OVER_HCI
329 static int hci_number_sco_connections(void){
330     int connections = 0;
331     btstack_linked_list_iterator_t it;
332     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
333     while (btstack_linked_list_iterator_has_next(&it)){
334         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
335         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
336         connections++;
337     }
338     return connections;
339 }
340 #endif
341 
342 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
343     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
344 #ifdef HAVE_EMBEDDED_TICK
345     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
346         // connections might be timed out
347         hci_emit_l2cap_check_timeout(connection);
348     }
349 #else
350     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
351         // connections might be timed out
352         hci_emit_l2cap_check_timeout(connection);
353     }
354 #endif
355 }
356 
357 static void hci_connection_timestamp(hci_connection_t *connection){
358 #ifdef HAVE_EMBEDDED_TICK
359     connection->timestamp = btstack_run_loop_embedded_get_ticks();
360 #else
361     connection->timestamp = btstack_run_loop_get_time_ms();
362 #endif
363 }
364 
365 /**
366  * add authentication flags and reset timer
367  * @note: assumes classic connection
368  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
369  */
370 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
371     bd_addr_t addr;
372     reverse_bd_addr(bd_addr, addr);
373     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
374     if (conn) {
375         connectionSetAuthenticationFlags(conn, flags);
376         hci_connection_timestamp(conn);
377     }
378 }
379 
380 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
381     hci_connection_t * conn = hci_connection_for_handle(handle);
382     if (!conn) return 0;
383     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
384     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
385     return 0;
386 }
387 
388 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
389     if (!hci_stack->link_key_db) return;
390     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
391     hci_stack->link_key_db->delete_link_key(addr);
392 }
393 
394 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
395     if (!hci_stack->link_key_db) return;
396     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
397     hci_stack->link_key_db->put_link_key(addr, link_key, type);
398 }
399 
400 void gap_delete_all_link_keys(void){
401     bd_addr_t  addr;
402     link_key_t link_key;
403     link_key_type_t type;
404     btstack_link_key_iterator_t it;
405     int ok = gap_link_key_iterator_init(&it);
406     if (!ok) {
407         log_error("could not initialize iterator");
408         return;
409     }
410     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
411         gap_drop_link_key_for_bd_addr(addr);
412     }
413     gap_link_key_iterator_done(&it);
414 }
415 
416 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
417     if (!hci_stack->link_key_db) return 0;
418     if (!hci_stack->link_key_db->iterator_init) return 0;
419     return hci_stack->link_key_db->iterator_init(it);
420 }
421 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){
422     if (!hci_stack->link_key_db) return 0;
423     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
424 }
425 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
426     if (!hci_stack->link_key_db) return;
427     hci_stack->link_key_db->iterator_done(it);
428 }
429 #endif
430 
431 static int hci_is_le_connection(hci_connection_t * connection){
432     switch (connection->address_type){
433         case BD_ADDR_TYPE_LE_PUBLIC:
434         case BD_ADDR_TYPE_LE_RANDOM:
435         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
436         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
437             return 1;
438         default:
439             return 0;
440     }
441 }
442 
443 /**
444  * count connections
445  */
446 static int nr_hci_connections(void){
447     int count = 0;
448     btstack_linked_item_t *it;
449     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
450         count++;
451     }
452     return count;
453 }
454 
455 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
456 
457     unsigned int num_packets_sent_classic = 0;
458     unsigned int num_packets_sent_le = 0;
459 
460     btstack_linked_item_t *it;
461     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
462         hci_connection_t * connection = (hci_connection_t *) it;
463         if (hci_is_le_connection(connection)){
464             num_packets_sent_le += connection->num_packets_sent;
465         }
466         if (connection->address_type == BD_ADDR_TYPE_ACL){
467             num_packets_sent_classic += connection->num_packets_sent;
468         }
469     }
470     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
471     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
472     int free_slots_le = 0;
473 
474     if (free_slots_classic < 0){
475         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);
476         return 0;
477     }
478 
479     if (hci_stack->le_acl_packets_total_num){
480         // if we have LE slots, they are used
481         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
482         if (free_slots_le < 0){
483             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);
484             return 0;
485         }
486     } else {
487         // otherwise, classic slots are used for LE, too
488         free_slots_classic -= num_packets_sent_le;
489         if (free_slots_classic < 0){
490             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);
491             return 0;
492         }
493     }
494 
495     switch (address_type){
496         case BD_ADDR_TYPE_UNKNOWN:
497             log_error("hci_number_free_acl_slots: unknown address type");
498             return 0;
499 
500         case BD_ADDR_TYPE_ACL:
501             return free_slots_classic;
502 
503         default:
504            if (hci_stack->le_acl_packets_total_num){
505                return free_slots_le;
506            }
507            return free_slots_classic;
508     }
509 }
510 
511 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
512     // get connection type
513     hci_connection_t * connection = hci_connection_for_handle(con_handle);
514     if (!connection){
515         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
516         return 0;
517     }
518     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
519 }
520 
521 #ifdef ENABLE_CLASSIC
522 static int hci_number_free_sco_slots(void){
523     unsigned int num_sco_packets_sent  = 0;
524     btstack_linked_item_t *it;
525     if (hci_stack->synchronous_flow_control_enabled){
526         // explicit flow control
527         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
528             hci_connection_t * connection = (hci_connection_t *) it;
529             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
530             num_sco_packets_sent += connection->num_packets_sent;
531         }
532         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
533             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
534             return 0;
535         }
536         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
537     } else {
538         // implicit flow control -- TODO
539         int num_ready = 0;
540         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
541             hci_connection_t * connection = (hci_connection_t *) it;
542             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
543             if (connection->sco_tx_ready == 0) continue;
544             num_ready++;
545         }
546         return num_ready;
547     }
548 }
549 #endif
550 
551 // only used to send HCI Host Number Completed Packets
552 static int hci_can_send_comand_packet_transport(void){
553     if (hci_stack->hci_packet_buffer_reserved) return 0;
554 
555     // check for async hci transport implementations
556     if (hci_stack->hci_transport->can_send_packet_now){
557         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
558             return 0;
559         }
560     }
561     return 1;
562 }
563 
564 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
565 int hci_can_send_command_packet_now(void){
566     if (hci_can_send_comand_packet_transport() == 0) return 0;
567     return hci_stack->num_cmd_packets > 0;
568 }
569 
570 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
571     // check for async hci transport implementations
572     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
573     return hci_stack->hci_transport->can_send_packet_now(packet_type);
574 }
575 
576 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
577     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
578     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
579 }
580 
581 int hci_can_send_acl_le_packet_now(void){
582     if (hci_stack->hci_packet_buffer_reserved) return 0;
583     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
584 }
585 
586 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
587     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
588     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
589 }
590 
591 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
592     if (hci_stack->hci_packet_buffer_reserved) return 0;
593     return hci_can_send_prepared_acl_packet_now(con_handle);
594 }
595 
596 #ifdef ENABLE_CLASSIC
597 int hci_can_send_acl_classic_packet_now(void){
598     if (hci_stack->hci_packet_buffer_reserved) return 0;
599     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
600 }
601 
602 int hci_can_send_prepared_sco_packet_now(void){
603     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return 0;
604     if (hci_have_usb_transport()){
605         return hci_stack->sco_can_send_now;
606     } else {
607         return hci_number_free_sco_slots() > 0;
608     }
609 }
610 
611 int hci_can_send_sco_packet_now(void){
612     if (hci_stack->hci_packet_buffer_reserved) return 0;
613     return hci_can_send_prepared_sco_packet_now();
614 }
615 
616 void hci_request_sco_can_send_now_event(void){
617     hci_stack->sco_waiting_for_can_send_now = 1;
618     hci_notify_if_sco_can_send_now();
619 }
620 #endif
621 
622 // used for internal checks in l2cap.c
623 int hci_is_packet_buffer_reserved(void){
624     return hci_stack->hci_packet_buffer_reserved;
625 }
626 
627 // reserves outgoing packet buffer. @returns 1 if successful
628 int hci_reserve_packet_buffer(void){
629     if (hci_stack->hci_packet_buffer_reserved) {
630         log_error("hci_reserve_packet_buffer called but buffer already reserved");
631         return 0;
632     }
633     hci_stack->hci_packet_buffer_reserved = 1;
634     return 1;
635 }
636 
637 void hci_release_packet_buffer(void){
638     hci_stack->hci_packet_buffer_reserved = 0;
639 }
640 
641 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
642 static int hci_transport_synchronous(void){
643     return hci_stack->hci_transport->can_send_packet_now == NULL;
644 }
645 
646 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
647 
648     // 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);
649 
650     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
651     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
652     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0)){
653         max_acl_data_packet_length = hci_stack->le_data_packets_length;
654     }
655 
656 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
657     if (hci_is_le_connection(connection)){
658         max_acl_data_packet_length = connection->le_max_tx_octets;
659     }
660 #endif
661 
662     log_debug("hci_send_acl_packet_fragments entered");
663 
664     int err;
665     // multiple packets could be send on a synchronous HCI transport
666     while (true){
667 
668         log_debug("hci_send_acl_packet_fragments loop entered");
669 
670         // get current data
671         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
672         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
673         int more_fragments = 0;
674 
675         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
676         if (current_acl_data_packet_length > max_acl_data_packet_length){
677             more_fragments = 1;
678             current_acl_data_packet_length = max_acl_data_packet_length;
679         }
680 
681         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
682         if (acl_header_pos > 0){
683             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
684             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
685             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
686         }
687 
688         // update header len
689         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
690 
691         // count packet
692         connection->num_packets_sent++;
693         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", more_fragments);
694 
695         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
696         if (more_fragments){
697             // update start of next fragment to send
698             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
699         } else {
700             // done
701             hci_stack->acl_fragmentation_pos = 0;
702             hci_stack->acl_fragmentation_total_size = 0;
703         }
704 
705         // send packet
706         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
707         const int size = current_acl_data_packet_length + 4;
708         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
709         hci_stack->acl_fragmentation_tx_active = 1;
710         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
711 
712         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", more_fragments);
713 
714         // done yet?
715         if (!more_fragments) break;
716 
717         // can send more?
718         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
719     }
720 
721     log_debug("hci_send_acl_packet_fragments loop over");
722 
723     // release buffer now for synchronous transport
724     if (hci_transport_synchronous()){
725         hci_stack->acl_fragmentation_tx_active = 0;
726         hci_release_packet_buffer();
727         hci_emit_transport_packet_sent();
728     }
729 
730     return err;
731 }
732 
733 // pre: caller has reserved the packet buffer
734 int hci_send_acl_packet_buffer(int size){
735 
736     // log_info("hci_send_acl_packet_buffer size %u", size);
737 
738     if (!hci_stack->hci_packet_buffer_reserved) {
739         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
740         return 0;
741     }
742 
743     uint8_t * packet = hci_stack->hci_packet_buffer;
744     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
745 
746     // check for free places on Bluetooth module
747     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
748         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
749         hci_release_packet_buffer();
750         hci_emit_transport_packet_sent();
751         return BTSTACK_ACL_BUFFERS_FULL;
752     }
753 
754     hci_connection_t *connection = hci_connection_for_handle( con_handle);
755     if (!connection) {
756         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
757         hci_release_packet_buffer();
758         hci_emit_transport_packet_sent();
759         return 0;
760     }
761 
762 #ifdef ENABLE_CLASSIC
763     hci_connection_timestamp(connection);
764 #endif
765 
766     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
767 
768     // setup data
769     hci_stack->acl_fragmentation_total_size = size;
770     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
771 
772     return hci_send_acl_packet_fragments(connection);
773 }
774 
775 #ifdef ENABLE_CLASSIC
776 // pre: caller has reserved the packet buffer
777 int hci_send_sco_packet_buffer(int size){
778 
779     // log_info("hci_send_acl_packet_buffer size %u", size);
780 
781     if (!hci_stack->hci_packet_buffer_reserved) {
782         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
783         return 0;
784     }
785 
786     uint8_t * packet = hci_stack->hci_packet_buffer;
787 
788     // skip checks in loopback mode
789     if (!hci_stack->loopback_mode){
790         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
791 
792         // check for free places on Bluetooth module
793         if (!hci_can_send_prepared_sco_packet_now()) {
794             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
795             hci_release_packet_buffer();
796             hci_emit_transport_packet_sent();
797             return BTSTACK_ACL_BUFFERS_FULL;
798         }
799 
800         // track send packet in connection struct
801         hci_connection_t *connection = hci_connection_for_handle( con_handle);
802         if (!connection) {
803             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
804             hci_release_packet_buffer();
805             hci_emit_transport_packet_sent();
806             return 0;
807         }
808 
809         if (hci_have_usb_transport()){
810             // token used
811             hci_stack->sco_can_send_now = 0;
812         } else {
813             if (hci_stack->synchronous_flow_control_enabled){
814                 connection->num_packets_sent++;
815             } else {
816                 connection->sco_tx_ready--;
817             }
818         }
819     }
820 
821     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
822     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
823 
824     if (hci_transport_synchronous()){
825         hci_release_packet_buffer();
826         hci_emit_transport_packet_sent();
827     }
828 
829     return err;
830 }
831 #endif
832 
833 static void acl_handler(uint8_t *packet, int size){
834 
835     // log_info("acl_handler: size %u", size);
836 
837     // get info
838     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
839     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
840     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
841     uint16_t acl_length         = READ_ACL_LENGTH(packet);
842 
843     // ignore non-registered handle
844     if (!conn){
845         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
846         return;
847     }
848 
849     // assert packet is complete
850     if ((acl_length + 4) != size){
851         log_error("hci.c: acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
852         return;
853     }
854 
855 #ifdef ENABLE_CLASSIC
856     // update idle timestamp
857     hci_connection_timestamp(conn);
858 #endif
859 
860 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
861     hci_stack->host_completed_packets = 1;
862     conn->num_packets_completed++;
863 #endif
864 
865     // handle different packet types
866     switch (acl_flags & 0x03) {
867 
868         case 0x01: // continuation fragment
869 
870             // sanity checks
871             if (conn->acl_recombination_pos == 0) {
872                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
873                 return;
874             }
875             if ((conn->acl_recombination_pos + acl_length) > (4 + HCI_ACL_BUFFER_SIZE)){
876                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
877                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
878                 conn->acl_recombination_pos = 0;
879                 return;
880             }
881 
882             // append fragment payload (header already stored)
883             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
884                          &packet[4], acl_length);
885             conn->acl_recombination_pos += acl_length;
886 
887             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
888             //        conn->acl_recombination_pos, conn->acl_recombination_length);
889 
890             // forward complete L2CAP packet if complete.
891             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4 + 4)){ // pos already incl. ACL header
892                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
893                 // reset recombination buffer
894                 conn->acl_recombination_length = 0;
895                 conn->acl_recombination_pos = 0;
896             }
897             break;
898 
899         case 0x02: { // first fragment
900 
901             // sanity check
902             if (conn->acl_recombination_pos) {
903                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
904                 conn->acl_recombination_pos = 0;
905             }
906 
907             // peek into L2CAP packet!
908             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
909 
910             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
911 
912             // compare fragment size to L2CAP packet size
913             if (acl_length >= (l2cap_length + 4)){
914                 // forward fragment as L2CAP packet
915                 hci_emit_acl_packet(packet, acl_length + 4);
916             } else {
917 
918                 if (acl_length > HCI_ACL_BUFFER_SIZE){
919                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
920                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
921                     return;
922                 }
923 
924                 // store first fragment and tweak acl length for complete package
925                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
926                              packet, acl_length + 4);
927                 conn->acl_recombination_pos    = acl_length + 4;
928                 conn->acl_recombination_length = l2cap_length;
929                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
930             }
931             break;
932 
933         }
934         default:
935             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
936             return;
937     }
938 
939     // execute main loop
940     hci_run();
941 }
942 
943 static void hci_shutdown_connection(hci_connection_t *conn){
944     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
945 
946 #ifdef ENABLE_CLASSIC
947 #ifdef ENABLE_SCO_OVER_HCI
948     int addr_type = conn->address_type;
949 #endif
950 #endif
951 
952     btstack_run_loop_remove_timer(&conn->timeout);
953 
954     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
955     btstack_memory_hci_connection_free( conn );
956 
957     // now it's gone
958     hci_emit_nr_connections_changed();
959 
960 #ifdef ENABLE_CLASSIC
961 #ifdef ENABLE_SCO_OVER_HCI
962     // update SCO
963     if (addr_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
964         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
965     }
966 #endif
967 #endif
968 }
969 
970 #ifdef ENABLE_CLASSIC
971 
972 static const uint16_t packet_type_sizes[] = {
973     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
974     HCI_ACL_DH1_SIZE, 0, 0, 0,
975     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
976     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
977 };
978 static const uint8_t  packet_type_feature_requirement_bit[] = {
979      0, // 3 slot packets
980      1, // 5 slot packets
981     25, // EDR 2 mpbs
982     26, // EDR 3 mbps
983     39, // 3 slot EDR packts
984     40, // 5 slot EDR packet
985 };
986 static const uint16_t packet_type_feature_packet_mask[] = {
987     0x0f00, // 3 slot packets
988     0xf000, // 5 slot packets
989     0x1102, // EDR 2 mpbs
990     0x2204, // EDR 3 mbps
991     0x0300, // 3 slot EDR packts
992     0x3000, // 5 slot EDR packet
993 };
994 
995 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
996     // enable packet types based on size
997     uint16_t packet_types = 0;
998     unsigned int i;
999     for (i=0;i<16;i++){
1000         if (packet_type_sizes[i] == 0) continue;
1001         if (packet_type_sizes[i] <= buffer_size){
1002             packet_types |= 1 << i;
1003         }
1004     }
1005     // disable packet types due to missing local supported features
1006     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1007         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1008         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1009         if (feature_set) continue;
1010         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1011         packet_types &= ~packet_type_feature_packet_mask[i];
1012     }
1013     // flip bits for "may not be used"
1014     packet_types ^= 0x3306;
1015     return packet_types;
1016 }
1017 
1018 uint16_t hci_usable_acl_packet_types(void){
1019     return hci_stack->packet_types;
1020 }
1021 #endif
1022 
1023 uint8_t* hci_get_outgoing_packet_buffer(void){
1024     // hci packet buffer is >= acl data packet length
1025     return hci_stack->hci_packet_buffer;
1026 }
1027 
1028 uint16_t hci_max_acl_data_packet_length(void){
1029     return hci_stack->acl_data_packet_length;
1030 }
1031 
1032 #ifdef ENABLE_CLASSIC
1033 int hci_extended_sco_link_supported(void){
1034     // No. 31, byte 3, bit 7
1035     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1036 }
1037 #endif
1038 
1039 int hci_non_flushable_packet_boundary_flag_supported(void){
1040     // No. 54, byte 6, bit 6
1041     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
1042 }
1043 
1044 static int gap_ssp_supported(void){
1045     // No. 51, byte 6, bit 3
1046     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
1047 }
1048 
1049 static int hci_classic_supported(void){
1050 #ifdef ENABLE_CLASSIC
1051     // No. 37, byte 4, bit 5, = No BR/EDR Support
1052     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1053 #else
1054     return 0;
1055 #endif
1056 }
1057 
1058 static int hci_le_supported(void){
1059 #ifdef ENABLE_BLE
1060     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1061     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
1062 #else
1063     return 0;
1064 #endif
1065 }
1066 
1067 #ifdef ENABLE_BLE
1068 
1069 /**
1070  * @brief Get addr type and address used for LE in Advertisements, Scan Responses,
1071  */
1072 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1073     *addr_type = hci_stack->le_own_addr_type;
1074     if (hci_stack->le_own_addr_type){
1075         (void)memcpy(addr, hci_stack->le_random_address, 6);
1076     } else {
1077         (void)memcpy(addr, hci_stack->local_bd_addr, 6);
1078     }
1079 }
1080 
1081 #ifdef ENABLE_LE_CENTRAL
1082 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1083 
1084     int offset = 3;
1085     int num_reports = packet[offset];
1086     offset += 1;
1087 
1088     int i;
1089     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1090     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1091     for (i=0; (i<num_reports) && (offset < size);i++){
1092         // sanity checks on data_length:
1093         uint8_t data_length = packet[offset + 8];
1094         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1095         if ((offset + 9 + data_length + 1) > size)    return;
1096         // setup event
1097         uint8_t event_size = 10 + data_length;
1098         int pos = 0;
1099         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1100         event[pos++] = event_size;
1101         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1102         offset += 8;
1103         pos += 8;
1104         event[pos++] = packet[offset + 1 + data_length]; // rssi
1105         event[pos++] = data_length;
1106         offset++;
1107         (void)memcpy(&event[pos], &packet[offset], data_length);
1108         pos +=    data_length;
1109         offset += data_length + 1; // rssi
1110         hci_emit_event(event, pos, 1);
1111     }
1112 }
1113 #endif
1114 #endif
1115 
1116 #ifdef ENABLE_BLE
1117 #ifdef ENABLE_LE_PERIPHERAL
1118 static void hci_reenable_advertisements_if_needed(void){
1119     if (!hci_stack->le_advertisements_active && hci_stack->le_advertisements_enabled){
1120         // get number of active le slave connections
1121         int num_slave_connections = 0;
1122         btstack_linked_list_iterator_t it;
1123         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1124         while (btstack_linked_list_iterator_has_next(&it)){
1125             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1126             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1127             if (con->state != OPEN) continue;
1128             if (con->role  != HCI_ROLE_SLAVE) continue;
1129             if (!hci_is_le_connection(con)) continue;
1130             num_slave_connections++;
1131         }
1132         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1133         if (num_slave_connections < hci_stack->le_max_number_peripheral_connections){
1134             hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
1135         }
1136     }
1137 }
1138 #endif
1139 #endif
1140 
1141 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1142 
1143 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1144     if (!hci_stack->config) return 0;
1145     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1146     // Limit baud rate for Broadcom chipsets to 3 mbps
1147     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1148         baud_rate = 3000000;
1149     }
1150     return baud_rate;
1151 }
1152 
1153 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1154     UNUSED(ds);
1155 
1156     switch (hci_stack->substate){
1157         case HCI_INIT_W4_SEND_RESET:
1158             log_info("Resend HCI Reset");
1159             hci_stack->substate = HCI_INIT_SEND_RESET;
1160             hci_stack->num_cmd_packets = 1;
1161             hci_run();
1162             break;
1163         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1164             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1165             if (hci_stack->hci_transport->reset_link){
1166                 hci_stack->hci_transport->reset_link();
1167             }
1168 
1169             /* fall through */
1170 
1171         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1172             log_info("Resend HCI Reset - CSR Warm Boot");
1173             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1174             hci_stack->num_cmd_packets = 1;
1175             hci_run();
1176             break;
1177         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1178             if (hci_stack->hci_transport->set_baudrate){
1179                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1180                 log_info("Local baud rate change to %"PRIu32"(timeout handler)", baud_rate);
1181                 hci_stack->hci_transport->set_baudrate(baud_rate);
1182             }
1183             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1184             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1185                 if (hci_stack->hci_transport->reset_link){
1186                     log_info("Link Reset");
1187                     hci_stack->hci_transport->reset_link();
1188                 }
1189                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1190                 hci_run();
1191             }
1192             break;
1193         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1194             // otherwise continue
1195             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1196             hci_send_cmd(&hci_read_local_supported_commands);
1197             break;
1198         default:
1199             break;
1200     }
1201 }
1202 #endif
1203 
1204 static void hci_initializing_next_state(void){
1205     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1206 }
1207 
1208 // assumption: hci_can_send_command_packet_now() == true
1209 static void hci_initializing_run(void){
1210     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1211     switch (hci_stack->substate){
1212         case HCI_INIT_SEND_RESET:
1213             hci_state_reset();
1214 
1215 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1216             // prepare reset if command complete not received in 100ms
1217             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1218             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1219             btstack_run_loop_add_timer(&hci_stack->timeout);
1220 #endif
1221             // send command
1222             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1223             hci_send_cmd(&hci_reset);
1224             break;
1225         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1226             hci_send_cmd(&hci_read_local_version_information);
1227             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1228             break;
1229         case HCI_INIT_SEND_READ_LOCAL_NAME:
1230             hci_send_cmd(&hci_read_local_name);
1231             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1232             break;
1233 
1234 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1235         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1236             hci_state_reset();
1237             // prepare reset if command complete not received in 100ms
1238             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1239             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1240             btstack_run_loop_add_timer(&hci_stack->timeout);
1241             // send command
1242             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1243             hci_send_cmd(&hci_reset);
1244             break;
1245         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1246             hci_state_reset();
1247             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1248             hci_send_cmd(&hci_reset);
1249             break;
1250         case HCI_INIT_SEND_BAUD_CHANGE: {
1251             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1252             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1253             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1254             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1255             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1256             // STLC25000D: baudrate change happens within 0.5 s after command was send,
1257             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1258             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1259                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1260                 btstack_run_loop_add_timer(&hci_stack->timeout);
1261             }
1262             break;
1263         }
1264         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1265             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1266             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1267             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1268             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1269             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1270             break;
1271         }
1272         case HCI_INIT_CUSTOM_INIT:
1273             // Custom initialization
1274             if (hci_stack->chipset && hci_stack->chipset->next_command){
1275                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1276                 int send_cmd = 0;
1277                 switch (hci_stack->chipset_result){
1278                     case BTSTACK_CHIPSET_VALID_COMMAND:
1279                         send_cmd = 1;
1280                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1281                         break;
1282                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1283                         send_cmd = 1;
1284                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1285                         log_info("CSR Warm Boot");
1286                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1287                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1288                         btstack_run_loop_add_timer(&hci_stack->timeout);
1289                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1290                             && hci_stack->config
1291                             && hci_stack->chipset
1292                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1293                             && hci_stack->hci_transport->set_baudrate
1294                             && hci_transport_uart_get_main_baud_rate()){
1295                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1296                         } else {
1297                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1298                         }
1299                         break;
1300                     default:
1301                         break;
1302                 }
1303 
1304                 if (send_cmd){
1305                     int size = 3 + hci_stack->hci_packet_buffer[2];
1306                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1307                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1308                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1309                     break;
1310                 }
1311                 log_info("Init script done");
1312 
1313                 // Init script download on Broadcom chipsets causes:
1314                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1315                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1316                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1317 
1318                     // - baud rate to reset, restore UART baud rate if needed
1319                     int need_baud_change = hci_stack->config
1320                         && hci_stack->chipset
1321                         && hci_stack->chipset->set_baudrate_command
1322                         && hci_stack->hci_transport->set_baudrate
1323                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1324                     if (need_baud_change) {
1325                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1326                         log_info("Local baud rate change to %"PRIu32" after init script (bcm)", baud_rate);
1327                         hci_stack->hci_transport->set_baudrate(baud_rate);
1328                     }
1329 
1330                     uint16_t bcm_delay_ms = 300;
1331                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1332                     //   -> Work around: wait here.
1333                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1334                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1335                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1336                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1337                     btstack_run_loop_add_timer(&hci_stack->timeout);
1338                     break;
1339                 }
1340             }
1341             // otherwise continue
1342             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1343             hci_send_cmd(&hci_read_local_supported_commands);
1344             break;
1345         case HCI_INIT_SET_BD_ADDR:
1346             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1347             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1348             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1349             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1350             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1351             break;
1352 #endif
1353 
1354         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1355             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1356             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1357             hci_send_cmd(&hci_read_local_supported_commands);
1358             break;
1359         case HCI_INIT_READ_BD_ADDR:
1360             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1361             hci_send_cmd(&hci_read_bd_addr);
1362             break;
1363         case HCI_INIT_READ_BUFFER_SIZE:
1364             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1365             hci_send_cmd(&hci_read_buffer_size);
1366             break;
1367         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1368             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1369             hci_send_cmd(&hci_read_local_supported_features);
1370             break;
1371 
1372 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1373         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1374             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1375             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1376             break;
1377         case HCI_INIT_HOST_BUFFER_SIZE:
1378             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1379             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1380                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1381             break;
1382 #endif
1383 
1384         case HCI_INIT_SET_EVENT_MASK:
1385             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1386             if (hci_le_supported()){
1387                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1388             } else {
1389                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1390                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1391             }
1392             break;
1393 
1394 #ifdef ENABLE_CLASSIC
1395         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1396             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1397             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1398             break;
1399         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1400             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1401             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1402             break;
1403         case HCI_INIT_WRITE_DEFAULT_LINK_POLICY_SETTING:
1404             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_LINK_POLICY_SETTING;
1405             hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1406             break;
1407         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1408             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1409             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1410             break;
1411         case HCI_INIT_WRITE_LOCAL_NAME: {
1412             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1413             hci_reserve_packet_buffer();
1414             uint8_t * packet = hci_stack->hci_packet_buffer;
1415             // construct HCI Command and send
1416             uint16_t opcode = hci_write_local_name.opcode;
1417             hci_stack->last_cmd_opcode = opcode;
1418             packet[0] = opcode & 0xff;
1419             packet[1] = opcode >> 8;
1420             packet[2] = DEVICE_NAME_LEN;
1421             memset(&packet[3], 0, DEVICE_NAME_LEN);
1422             uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1423             uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1424             // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1425             (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1426             // expand '00:00:00:00:00:00' in name with bd_addr
1427             btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1428             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1429             break;
1430         }
1431         case HCI_INIT_WRITE_EIR_DATA: {
1432             hci_stack->substate = HCI_INIT_W4_WRITE_EIR_DATA;
1433             hci_reserve_packet_buffer();
1434             uint8_t * packet = hci_stack->hci_packet_buffer;
1435             // construct HCI Command in-place and send
1436             uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1437             hci_stack->last_cmd_opcode = opcode;
1438             uint16_t offset = 0;
1439             packet[offset++] = opcode & 0xff;
1440             packet[offset++] = opcode >> 8;
1441             packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1442             packet[offset++] = 0;  // FEC not required
1443             memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1444             if (hci_stack->eir_data){
1445                 // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1446                 ad_context_t context;
1447                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1448                     uint8_t data_type   = ad_iterator_get_data_type(&context);
1449                     uint8_t size        = ad_iterator_get_data_len(&context);
1450                     const uint8_t *data = ad_iterator_get_data(&context);
1451                     // copy item
1452                     packet[offset++] = size + 1;
1453                     packet[offset++] = data_type;
1454                     memcpy(&packet[offset], data, size);
1455                     // update name item
1456                     if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1457                         btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1458                     }
1459                     offset += size;
1460                 }
1461             } else {
1462                 uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1463                 uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1464                 packet[offset++] = bytes_to_copy + 1;
1465                 packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1466                 (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1467                 // expand '00:00:00:00:00:00' in name with bd_addr
1468                 btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1469             }
1470             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1471             break;
1472         }
1473         case HCI_INIT_WRITE_INQUIRY_MODE:
1474             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1475             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1476             break;
1477         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1478             hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1479             hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1480             break;
1481         case HCI_INIT_WRITE_SCAN_ENABLE:
1482             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1483             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1484             break;
1485         // only sent if ENABLE_SCO_OVER_HCI is defined
1486         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1487             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1488             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1489             break;
1490         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1491             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1492             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1493             break;
1494         // only sent if ENABLE_SCO_OVER_HCI and manufacturer is Broadcom
1495         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1496             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1497             log_info("BCM: Route SCO data via HCI transport");
1498             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1499             break;
1500 
1501 #endif
1502 #ifdef ENABLE_BLE
1503         // LE INIT
1504         case HCI_INIT_LE_READ_BUFFER_SIZE:
1505             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1506             hci_send_cmd(&hci_le_read_buffer_size);
1507             break;
1508         case HCI_INIT_LE_SET_EVENT_MASK:
1509             hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1510             hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1511             break;
1512         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1513             // LE Supported Host = 1, Simultaneous Host = 0
1514             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1515             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1516             break;
1517 #endif
1518 
1519 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1520         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1521             hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1522             hci_send_cmd(&hci_le_read_maximum_data_length);
1523             break;
1524         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1525             hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1526             hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1527             break;
1528 #endif
1529 
1530 #ifdef ENABLE_LE_CENTRAL
1531         case HCI_INIT_READ_WHITE_LIST_SIZE:
1532             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1533             hci_send_cmd(&hci_le_read_white_list_size);
1534             break;
1535         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1536             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, own address type, accept all advs
1537             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1538             hci_send_cmd(&hci_le_set_scan_parameters, 1, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->le_own_addr_type, 0);
1539             break;
1540 #endif
1541         default:
1542             return;
1543     }
1544 }
1545 
1546 static void hci_init_done(void){
1547     // done. tell the app
1548     log_info("hci_init_done -> HCI_STATE_WORKING");
1549     hci_stack->state = HCI_STATE_WORKING;
1550     hci_emit_state();
1551     hci_run();
1552 }
1553 
1554 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1555     bool command_completed = false;
1556     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1557         uint16_t opcode = little_endian_read_16(packet,3);
1558         if (opcode == hci_stack->last_cmd_opcode){
1559             command_completed = true;
1560             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1561         } else {
1562             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1563         }
1564     }
1565 
1566     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1567         uint8_t  status = packet[2];
1568         uint16_t opcode = little_endian_read_16(packet,4);
1569         if (opcode == hci_stack->last_cmd_opcode){
1570             if (status){
1571                 command_completed = true;
1572                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1573             } else {
1574                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1575             }
1576         } else {
1577             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1578         }
1579     }
1580 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1581     // Vendor == CSR
1582     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1583         // TODO: track actual command
1584         command_completed = true;
1585     }
1586 
1587     // Vendor == Toshiba
1588     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1589         // TODO: track actual command
1590         command_completed = true;
1591         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1592         hci_stack->num_cmd_packets = 1;
1593     }
1594 #endif
1595 
1596     return command_completed;
1597 }
1598 
1599 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1600 
1601     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1602 
1603     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1604 
1605 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1606 
1607     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1608     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1609     //
1610     // HCI Reset
1611     // Timeout 100 ms
1612     // HCI Reset
1613     // Command Complete Reset
1614     // HCI Read Local Version Information
1615     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1616     // hang...
1617     //
1618     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1619     if (!command_completed
1620             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1621             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1622 
1623         uint16_t opcode = little_endian_read_16(packet,3);
1624         if (opcode == hci_reset.opcode){
1625             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1626             return;
1627         }
1628     }
1629 
1630     // CSR & H5
1631     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1632     if (!command_completed
1633             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1634             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1635 
1636         uint16_t opcode = little_endian_read_16(packet,3);
1637         if (opcode == hci_reset.opcode){
1638             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1639             return;
1640         }
1641     }
1642 
1643     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1644     // fix: Correct substate and behave as command below
1645     if (command_completed){
1646         switch (hci_stack->substate){
1647             case HCI_INIT_SEND_RESET:
1648                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1649                 break;
1650             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1651                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1652                 break;
1653             default:
1654                 break;
1655         }
1656     }
1657 
1658 #endif
1659 
1660     if (!command_completed) return;
1661 
1662     bool need_baud_change = false;
1663     bool need_addr_change = false;
1664 
1665 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1666     need_baud_change = hci_stack->config
1667                         && hci_stack->chipset
1668                         && hci_stack->chipset->set_baudrate_command
1669                         && hci_stack->hci_transport->set_baudrate
1670                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1671 
1672     need_addr_change = hci_stack->custom_bd_addr_set
1673                         && hci_stack->chipset
1674                         && hci_stack->chipset->set_bd_addr_command;
1675 #endif
1676 
1677     switch(hci_stack->substate){
1678 
1679 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1680         case HCI_INIT_SEND_RESET:
1681             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1682             // fix: just correct substate and behave as command below
1683             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1684             btstack_run_loop_remove_timer(&hci_stack->timeout);
1685             break;
1686         case HCI_INIT_W4_SEND_RESET:
1687             btstack_run_loop_remove_timer(&hci_stack->timeout);
1688             break;
1689         case HCI_INIT_W4_SEND_READ_LOCAL_NAME:
1690             log_info("Received local name, need baud change %d", (int) need_baud_change);
1691             if (need_baud_change){
1692                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1693                 return;
1694             }
1695             // skip baud change
1696             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1697             return;
1698         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1699             // for STLC2500D, baud rate change already happened.
1700             // for others, baud rate gets changed now
1701             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1702                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1703                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change)", baud_rate);
1704                 hci_stack->hci_transport->set_baudrate(baud_rate);
1705             }
1706             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1707             return;
1708         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1709             btstack_run_loop_remove_timer(&hci_stack->timeout);
1710             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1711             return;
1712         case HCI_INIT_W4_CUSTOM_INIT:
1713             // repeat custom init
1714             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1715             return;
1716 #else
1717         case HCI_INIT_W4_SEND_RESET:
1718             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1719             return ;
1720 #endif
1721 
1722         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1723             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1724               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1725                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1726                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1727                 return;
1728             }
1729             if (need_addr_change){
1730                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1731                 return;
1732             }
1733             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1734             return;
1735 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1736         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1737             if (need_baud_change){
1738                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1739                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change_bcm))", baud_rate);
1740                 hci_stack->hci_transport->set_baudrate(baud_rate);
1741             }
1742             if (need_addr_change){
1743                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1744                 return;
1745             }
1746             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1747             return;
1748         case HCI_INIT_W4_SET_BD_ADDR:
1749             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1750             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1751             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1752                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1753                 return;
1754             }
1755             // skipping st warm boot
1756             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1757             return;
1758         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1759             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1760             return;
1761 #endif
1762         case HCI_INIT_W4_READ_BD_ADDR:
1763             // only read buffer size if supported
1764             if (hci_stack->local_supported_commands[0] & 0x01) {
1765                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1766                 return;
1767             }
1768             // skipping read buffer size
1769             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1770             return;
1771         case HCI_INIT_W4_SET_EVENT_MASK:
1772             // skip Classic init commands for LE only chipsets
1773             if (!hci_classic_supported()){
1774 #ifdef ENABLE_BLE
1775                 if (hci_le_supported()){
1776                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1777                     return;
1778                 }
1779 #endif
1780                 log_error("Neither BR/EDR nor LE supported");
1781                 hci_init_done();
1782                 return;
1783             }
1784             if (!gap_ssp_supported()){
1785                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1786                 return;
1787             }
1788             break;
1789 #ifdef ENABLE_BLE
1790         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1791             // skip write le host if not supported (e.g. on LE only EM9301)
1792             if (hci_stack->local_supported_commands[0] & 0x02) break;
1793             hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1794             return;
1795 
1796 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1797         case HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED:
1798             log_info("Supported commands %x", hci_stack->local_supported_commands[0] & 0x30);
1799             if ((hci_stack->local_supported_commands[0] & 0x30) == 0x30){
1800                 hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1801                 return;
1802             }
1803             // explicit fall through to reduce repetitions
1804 
1805 #ifdef ENABLE_LE_CENTRAL
1806             hci_stack->substate = HCI_INIT_READ_WHITE_LIST_SIZE;
1807 #else
1808             hci_init_done();
1809 #endif
1810             return;
1811 #endif  /* ENABLE_LE_DATA_LENGTH_EXTENSION */
1812 
1813 #endif  /* ENABLE_BLE */
1814 
1815         case HCI_INIT_W4_WRITE_INQUIRY_MODE:
1816             // skip write secure connections host support if not supported or disabled
1817             if (!hci_stack->secure_connections_enable || (hci_stack->local_supported_commands[1] & 0x02) == 0) {
1818                 hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;
1819                 return;
1820             }
1821             break;
1822 
1823 #ifdef ENABLE_SCO_OVER_HCI
1824         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1825             // skip write synchronous flow control if not supported
1826             if (hci_stack->local_supported_commands[0] & 0x04) break;
1827             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1828 
1829             /* fall through */
1830 
1831         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1832             // skip write default erroneous data reporting if not supported
1833             if (hci_stack->local_supported_commands[0] & 0x08) break;
1834             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1835 
1836             /* fall through */
1837 
1838         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1839             // skip bcm set sco pcm config on non-Broadcom chipsets
1840             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) break;
1841             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1842 
1843             /* fall through */
1844 
1845         case HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT:
1846             if (!hci_le_supported()){
1847                 // SKIP LE init for Classic only configuration
1848                 hci_init_done();
1849                 return;
1850             }
1851             break;
1852 
1853 #else /* !ENABLE_SCO_OVER_HCI */
1854 
1855         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1856 #ifdef ENABLE_BLE
1857             if (hci_le_supported()){
1858                 hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE;
1859                 return;
1860             }
1861 #endif
1862             // SKIP LE init for Classic only configuration
1863             hci_init_done();
1864             return;
1865 #endif /* ENABLE_SCO_OVER_HCI */
1866 
1867 // avoid compile error due to duplicate cases: HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT == HCI_INIT_DONE-1
1868 #if defined(ENABLE_BLE) || defined(ENABLE_LE_DATA_LENGTH_EXTENSION) || defined(ENABLE_LE_CENTRAL)
1869         // Response to command before init done state -> init done
1870         case (HCI_INIT_DONE-1):
1871             hci_init_done();
1872             return;
1873 #endif
1874 
1875         default:
1876             break;
1877     }
1878     hci_initializing_next_state();
1879 }
1880 
1881 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
1882     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
1883     bd_addr_t bd_address;
1884     (void)memcpy(&bd_address, conn->address, 6);
1885 
1886 #ifdef ENABLE_CLASSIC
1887     // cache needed data
1888     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1889 #endif
1890 
1891     // connection failed, remove entry
1892     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1893     btstack_memory_hci_connection_free( conn );
1894 
1895 #ifdef ENABLE_CLASSIC
1896     // notify client if dedicated bonding
1897     if (notify_dedicated_bonding_failed){
1898         log_info("hci notify_dedicated_bonding_failed");
1899         hci_emit_dedicated_bonding_result(bd_address, status);
1900     }
1901 
1902     // if authentication error, also delete link key
1903     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
1904         gap_drop_link_key_for_bd_addr(bd_address);
1905     }
1906 #endif
1907 }
1908 
1909 #ifdef ENABLE_CLASSIC
1910 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
1911     // SSP Controller
1912     if (features[6] & (1 << 3)){
1913         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
1914     }
1915     // eSCO
1916     if (features[3] & (1<<7)){
1917         conn->remote_supported_features[0] |= 1;
1918     }
1919     // Extended features
1920     if (features[7] & (1<<7)){
1921         conn->remote_supported_features[0] |= 2;
1922     }
1923 }
1924 
1925 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
1926     // SSP Host
1927     if (features[0] & (1 << 0)){
1928         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
1929     }
1930     // SC Host
1931     if (features[0] & (1 << 3)){
1932         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
1933     }
1934 }
1935 
1936 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
1937     // SC Controller
1938     if (features[1] & (1 << 0)){
1939         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
1940     }
1941 }
1942 
1943 static void hci_handle_remote_features_received(hci_connection_t * conn){
1944     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1945     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
1946     if (conn->bonding_flags & BONDING_DEDICATED){
1947         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1948     }
1949 }
1950 #endif
1951 
1952 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
1953     // handle BT initialization
1954     if (hci_stack->state == HCI_STATE_INITIALIZING) {
1955         hci_initializing_event_handler(packet, size);
1956     }
1957 
1958     // help with BT sleep
1959     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
1960         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
1961         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
1962         hci_initializing_next_state();
1963     }
1964 }
1965 
1966 #ifdef ENABLE_CLASSIC
1967 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
1968     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1969     conn->encryption_key_size = encryption_key_size;
1970 
1971     if ((conn->authentication_flags & CONNECTION_AUTHENTICATED) != 0) {
1972         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
1973         return;
1974     }
1975 
1976     // Request Authentication if not already done
1977     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
1978     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1979 }
1980 #endif
1981 
1982 static void event_handler(uint8_t *packet, int size){
1983 
1984     uint16_t event_length = packet[1];
1985 
1986     // assert packet is complete
1987     if (size != (event_length + 2)){
1988         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
1989         return;
1990     }
1991 
1992     bd_addr_t addr;
1993     bd_addr_type_t addr_type;
1994     hci_con_handle_t handle;
1995     hci_connection_t * conn;
1996     int i;
1997     int create_connection_cmd;
1998 
1999 #ifdef ENABLE_CLASSIC
2000     uint8_t link_type;
2001 #endif
2002 
2003     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2004 
2005     switch (hci_event_packet_get_type(packet)) {
2006 
2007         case HCI_EVENT_COMMAND_COMPLETE:
2008             // get num cmd packets - limit to 1 to reduce complexity
2009             hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2010 
2011             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_name)){
2012                 if (packet[5]) break;
2013                 // terminate, name 248 chars
2014                 packet[6+248] = 0;
2015                 log_info("local name: %s", &packet[6]);
2016             }
2017             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_buffer_size)){
2018                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2019                 if (hci_stack->state == HCI_STATE_INITIALIZING){
2020                     uint16_t acl_len = little_endian_read_16(packet, 6);
2021                     uint16_t sco_len = packet[8];
2022 
2023                     // determine usable ACL/SCO payload size
2024                     hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2025                     hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2026 
2027                     hci_stack->acl_packets_total_num  = little_endian_read_16(packet, 9);
2028                     hci_stack->sco_packets_total_num  = little_endian_read_16(packet, 11);
2029 
2030                     log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2031                              acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2032                              hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2033                 }
2034             }
2035             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_rssi)){
2036                 if (packet[5] == 0){
2037                     uint8_t event[5];
2038                     event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2039                     event[1] = 3;
2040                     (void)memcpy(&event[2], &packet[6], 3);
2041                     hci_emit_event(event, sizeof(event), 1);
2042                 }
2043             }
2044 #ifdef ENABLE_BLE
2045             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_buffer_size)){
2046                 hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2047                 hci_stack->le_acl_packets_total_num  = packet[8];
2048                 // determine usable ACL payload size
2049                 if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2050                     hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2051                 }
2052                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2053             }
2054 #endif
2055 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2056             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_maximum_data_length)){
2057                 hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2058                 hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2059                 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);
2060             }
2061 #endif
2062 #ifdef ENABLE_LE_CENTRAL
2063             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_white_list_size)){
2064                 hci_stack->le_whitelist_capacity = packet[6];
2065                 log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2066             }
2067 #endif
2068             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)) {
2069                 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1],
2070 				hci_stack->local_bd_addr);
2071                 log_info("Local Address, Status: 0x%02x: Addr: %s",
2072                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
2073 #ifdef ENABLE_CLASSIC
2074                 if (hci_stack->link_key_db){
2075                     hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2076                 }
2077 #endif
2078             }
2079 #ifdef ENABLE_CLASSIC
2080             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
2081                 hci_emit_discoverable_enabled(hci_stack->discoverable);
2082             }
2083             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_inquiry_cancel)){
2084                 if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2085                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2086                     uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2087                     hci_emit_event(event, sizeof(event), 1);
2088                 }
2089             }
2090 #endif
2091 
2092             // Note: HCI init checks
2093             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_features)){
2094                 (void)memcpy(hci_stack->local_supported_features,
2095 			     &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1],
2096 			     8);
2097 
2098 #ifdef ENABLE_CLASSIC
2099                 // determine usable ACL packet types based on host buffer size and supported features
2100                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2101                 log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2102 #endif
2103                 // Classic/LE
2104                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2105             }
2106             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_version_information)){
2107                 // hci_stack->hci_version    = little_endian_read_16(packet, 4);
2108                 // hci_stack->hci_revision   = little_endian_read_16(packet, 6);
2109                 uint16_t manufacturer = little_endian_read_16(packet, 10);
2110                 // map Cypress to Broadcom
2111                 if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2112                     log_info("Treat Cypress as Broadcom");
2113                     manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2114                     little_endian_store_16(packet, 10, manufacturer);
2115                 }
2116                 hci_stack->manufacturer = manufacturer;
2117                 // hci_stack->lmp_version    = little_endian_read_16(packet, 8);
2118                 // hci_stack->lmp_subversion = little_endian_read_16(packet, 12);
2119                 log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2120             }
2121             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){
2122                 hci_stack->local_supported_commands[0] =
2123                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+14] & 0x80) >> 7) |  // bit 0 = Octet 14, bit 7 / Read Buffer Size
2124                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+24] & 0x40) >> 5) |  // bit 1 = Octet 24, bit 6 / Write Le Host Supported
2125                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+10] & 0x10) >> 2) |  // bit 2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2126                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+18] & 0x08)     ) |  // bit 3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2127                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x01) << 4) |  // bit 4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2128                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+35] & 0x08) << 2) |  // bit 5 = Octet 35, bit 3 / LE Read Maximum Data Length
2129                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+35] & 0x20) << 1) |  // bit 6 = Octet 35, bit 5 / LE Set Default PHY
2130                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+20] & 0x10) << 3);   // bit 7 = Octet 20, bit 4 / Read Encryption Key Size
2131                 hci_stack->local_supported_commands[1] =
2132                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+ 2] & 0x40) >> 6) |  // bit 8 = Octet  2, bit 6 / Read Remote Extended Features
2133                     ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+32] & 0x08) >> 2);   // bit 9 = Octet 32, bit 3 / Write Secure Connections Host
2134                 log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2135             }
2136 #ifdef ENABLE_CLASSIC
2137             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_synchronous_flow_control_enable)){
2138                 if (packet[5] == 0){
2139                     hci_stack->synchronous_flow_control_enabled = 1;
2140                 }
2141             }
2142             else if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_encryption_key_size)){
2143                 uint8_t status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2144                 handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2145                 conn   = hci_connection_for_handle(handle);
2146                 if (!conn) break;
2147                 uint8_t key_size = 0;
2148                 if (status == 0){
2149                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2150                     log_info("Handle %x04x key Size: %u", handle, key_size);
2151                 } else {
2152                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2153                 }
2154                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2155             }
2156 #endif
2157             break;
2158 
2159         case HCI_EVENT_COMMAND_STATUS:
2160             // get num cmd packets - limit to 1 to reduce complexity
2161             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2162 
2163             // check command status to detected failed outgoing connections
2164             create_connection_cmd = 0;
2165 #ifdef ENABLE_CLASSIC
2166             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2167                 create_connection_cmd = 1;
2168             }
2169 #endif
2170 #ifdef ENABLE_LE_CENTRAL
2171             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2172                 create_connection_cmd = 1;
2173             }
2174 #endif
2175             if (create_connection_cmd) {
2176                 uint8_t status = hci_event_command_status_get_status(packet);
2177                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, hci_stack->outgoing_addr_type);
2178                 log_info("command status (create connection), status %x, connection %p, addr %s, type %x", status, conn, bd_addr_to_str(hci_stack->outgoing_addr), hci_stack->outgoing_addr_type);
2179 
2180                 // reset outgoing address info
2181                 memset(hci_stack->outgoing_addr, 0, 6);
2182                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2183 
2184                 // error => outgoing connection failed
2185                 if ((conn != NULL) && (status != 0)){
2186                     hci_handle_connection_failed(conn, status);
2187                 }
2188             }
2189             break;
2190 
2191         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2192             if (size < 3) return;
2193             uint16_t num_handles = packet[2];
2194             if (size != (3 + num_handles * 4)) return;
2195             uint16_t offset = 3;
2196             for (i=0; i<num_handles;i++){
2197                 handle = little_endian_read_16(packet, offset) & 0x0fff;
2198                 offset += 2;
2199                 uint16_t num_packets = little_endian_read_16(packet, offset);
2200                 offset += 2;
2201 
2202                 conn = hci_connection_for_handle(handle);
2203                 if (!conn){
2204                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2205                     continue;
2206                 }
2207 
2208                 if (conn->num_packets_sent >= num_packets){
2209                     conn->num_packets_sent -= num_packets;
2210                 } else {
2211                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2212                     conn->num_packets_sent = 0;
2213                 }
2214                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2215 
2216 #ifdef ENABLE_CLASSIC
2217                 // For SCO, we do the can_send_now_check here
2218                 hci_notify_if_sco_can_send_now();
2219 #endif
2220             }
2221             break;
2222         }
2223 
2224 #ifdef ENABLE_CLASSIC
2225         case HCI_EVENT_INQUIRY_COMPLETE:
2226             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2227                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2228                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2229                 hci_emit_event(event, sizeof(event), 1);
2230             }
2231             break;
2232         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2233             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2234                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2235             }
2236             break;
2237         case HCI_EVENT_CONNECTION_REQUEST:
2238             reverse_bd_addr(&packet[2], addr);
2239             if (hci_stack->gap_classic_accept_callback != NULL){
2240                 if ((*hci_stack->gap_classic_accept_callback)(addr) == 0){
2241                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2242                     bd_addr_copy(hci_stack->decline_addr, addr);
2243                     break;
2244                 }
2245             }
2246 
2247             // TODO: eval COD 8-10
2248             link_type = packet[11];
2249             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
2250             addr_type = (link_type == 1) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2251             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2252             if (!conn) {
2253                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2254             }
2255             if (!conn) {
2256                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2257                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2258                 bd_addr_copy(hci_stack->decline_addr, addr);
2259                 break;
2260             }
2261             conn->role  = HCI_ROLE_SLAVE;
2262             conn->state = RECEIVED_CONNECTION_REQUEST;
2263             // store info about eSCO
2264             if (link_type == 0x02){
2265                 conn->remote_supported_features[0] |= 1;
2266             }
2267             hci_run();
2268             break;
2269 
2270         case HCI_EVENT_CONNECTION_COMPLETE:
2271             // Connection management
2272             reverse_bd_addr(&packet[5], addr);
2273             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2274             addr_type = BD_ADDR_TYPE_ACL;
2275             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2276             if (conn) {
2277                 if (!packet[2]){
2278                     conn->state = OPEN;
2279                     conn->con_handle = little_endian_read_16(packet, 3);
2280 
2281                     // queue get remote feature
2282                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2283 
2284                     // queue set supervision timeout if we're master
2285                     if ((hci_stack->link_supervision_timeout != 0) && (conn->role == HCI_ROLE_MASTER)){
2286                         connectionSetAuthenticationFlags(conn, WRITE_SUPERVISION_TIMEOUT);
2287                     }
2288 
2289                     // restart timer
2290                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2291                     btstack_run_loop_add_timer(&conn->timeout);
2292 
2293                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2294 
2295                     hci_emit_nr_connections_changed();
2296                 } else {
2297                     // connection failed
2298                     hci_handle_connection_failed(conn, packet[2]);
2299                 }
2300             }
2301             break;
2302 
2303         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2304             reverse_bd_addr(&packet[5], addr);
2305             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2306             if (packet[2]){
2307                 // connection failed
2308                 break;
2309             }
2310             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2311             if (!conn) {
2312                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2313             }
2314             if (!conn) {
2315                 break;
2316             }
2317             conn->state = OPEN;
2318             conn->con_handle = little_endian_read_16(packet, 3);
2319 
2320 #ifdef ENABLE_SCO_OVER_HCI
2321             // update SCO
2322             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2323                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2324             }
2325             // trigger can send now
2326             if (hci_have_usb_transport()){
2327                 hci_stack->sco_can_send_now = 1;
2328             }
2329 #endif
2330             break;
2331 
2332         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2333             handle = little_endian_read_16(packet, 3);
2334             conn = hci_connection_for_handle(handle);
2335             if (!conn) break;
2336             if (!packet[2]){
2337                 const uint8_t * features = &packet[5];
2338                 hci_handle_remote_features_page_0(conn, features);
2339 
2340                 // read extended features if possible
2341                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2342                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2343                     break;
2344                 }
2345             }
2346             hci_handle_remote_features_received(conn);
2347             break;
2348 
2349         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2350             handle = little_endian_read_16(packet, 3);
2351             conn = hci_connection_for_handle(handle);
2352             if (!conn) break;
2353             // status = ok, page = 1
2354             if (!packet[2]) {
2355                 uint8_t page_number = packet[5];
2356                 uint8_t maximum_page_number = packet[6];
2357                 const uint8_t * features = &packet[7];
2358                 bool done = false;
2359                 switch (page_number){
2360                     case 1:
2361                         hci_handle_remote_features_page_1(conn, features);
2362                         if (maximum_page_number >= 2){
2363                             // get Secure Connections (Controller) from Page 2 if available
2364                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2365                         } else {
2366                             // otherwise, assume SC (Controller) == SC (Host)
2367                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2368                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2369                             }
2370                             done = true;
2371                         }
2372                         break;
2373                     case 2:
2374                         hci_handle_remote_features_page_2(conn, features);
2375                         done = true;
2376                         break;
2377                     default:
2378                         break;
2379                 }
2380                 if (!done) break;
2381             }
2382             hci_handle_remote_features_received(conn);
2383             break;
2384 
2385         case HCI_EVENT_LINK_KEY_REQUEST:
2386             log_info("HCI_EVENT_LINK_KEY_REQUEST");
2387             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
2388             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
2389             if (hci_stack->bondable && !hci_stack->link_key_db) break;
2390             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
2391             hci_run();
2392             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
2393             return;
2394 
2395         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2396             reverse_bd_addr(&packet[2], addr);
2397             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2398             if (!conn) break;
2399             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
2400             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2401             // Change Connection Encryption keeps link key type
2402             if (link_key_type != CHANGED_COMBINATION_KEY){
2403                 conn->link_key_type = link_key_type;
2404             }
2405             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2406             // still forward event to allow dismiss of pairing dialog
2407             break;
2408         }
2409 
2410         case HCI_EVENT_PIN_CODE_REQUEST:
2411             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
2412             // non-bondable mode: pin code negative reply will be sent
2413             if (!hci_stack->bondable){
2414                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
2415                 hci_run();
2416                 return;
2417             }
2418             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
2419             if (!hci_stack->link_key_db) break;
2420             hci_event_pin_code_request_get_bd_addr(packet, addr);
2421             hci_stack->link_key_db->delete_link_key(addr);
2422             break;
2423 
2424         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2425             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
2426             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
2427             break;
2428 
2429         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2430             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2431             if (!hci_stack->ssp_auto_accept) break;
2432             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
2433             break;
2434 
2435         case HCI_EVENT_USER_PASSKEY_REQUEST:
2436             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2437             if (!hci_stack->ssp_auto_accept) break;
2438             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
2439             break;
2440         case HCI_EVENT_MODE_CHANGE:
2441             handle = hci_event_mode_change_get_handle(packet);
2442             conn = hci_connection_for_handle(handle);
2443             if (!conn) break;
2444             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2445             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2446             break;
2447 #endif
2448 
2449         case HCI_EVENT_ENCRYPTION_CHANGE:
2450             handle = hci_event_encryption_change_get_connection_handle(packet);
2451             conn = hci_connection_for_handle(handle);
2452             if (!conn) break;
2453             if (hci_event_encryption_change_get_status(packet) == 0) {
2454                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2455                 if (encryption_enabled){
2456                     if (hci_is_le_connection(conn)){
2457                         // For LE, we accept connection as encrypted
2458                         conn->authentication_flags |= CONNECTION_ENCRYPTED;
2459                     }
2460 #ifdef ENABLE_CLASSIC
2461                     else {
2462                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
2463                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
2464                         bool connected_uses_aes_ccm = encryption_enabled == 2;
2465                         if (sc_used_during_pairing && !connected_uses_aes_ccm){
2466                             log_info("SC during pairing, but only E0 now -> abort");
2467                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2468                             break;
2469                         }
2470 
2471                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
2472                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
2473                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
2474                         } else {
2475                             // if not, pretend everything is perfect
2476                             hci_handle_read_encryption_key_size_complete(conn, 16);
2477                         }
2478                     }
2479 #endif
2480                 } else {
2481                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
2482                 }
2483             }
2484 
2485             break;
2486 
2487 #ifdef ENABLE_CLASSIC
2488         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
2489             handle = hci_event_authentication_complete_get_connection_handle(packet);
2490             conn = hci_connection_for_handle(handle);
2491             if (!conn) break;
2492 
2493             // ignore authentication event if we didn't request it
2494             if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) == 0) break;
2495 
2496             // dedicated bonding: send result and disconnect
2497             if (conn->bonding_flags & BONDING_DEDICATED){
2498                 conn->bonding_flags &= ~BONDING_DEDICATED;
2499                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
2500                 conn->bonding_status = packet[2];
2501                 break;
2502             }
2503 
2504             // authenticated only if auth status == 0
2505             if (hci_event_authentication_complete_get_status(packet) == 0){
2506                 // authenticated
2507                 conn->authentication_flags |= CONNECTION_AUTHENTICATED;
2508 
2509                 // If link key sufficient for requested security and not already encrypted, start encryption
2510                 if (((gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level)) &&
2511                     ((conn->authentication_flags & CONNECTION_ENCRYPTED) == 0)){
2512                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2513                     break;
2514                 }
2515             }
2516 
2517             // emit updated security level
2518             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
2519             break;
2520 #endif
2521 
2522         // HCI_EVENT_DISCONNECTION_COMPLETE
2523         // has been split, to first notify stack before shutting connection down
2524         // see end of function, too.
2525         case HCI_EVENT_DISCONNECTION_COMPLETE:
2526             if (packet[2]) break;   // status != 0
2527             handle = little_endian_read_16(packet, 3);
2528             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
2529             if (hci_stack->acl_fragmentation_total_size > 0) {
2530                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
2531                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0;
2532                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
2533                     hci_stack->acl_fragmentation_total_size = 0;
2534                     hci_stack->acl_fragmentation_pos = 0;
2535                     if (release_buffer){
2536                         hci_release_packet_buffer();
2537                     }
2538                 }
2539             }
2540 
2541             conn = hci_connection_for_handle(handle);
2542             if (!conn) break;
2543             // mark connection for shutdown
2544             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
2545 
2546             // emit dedicatd bonding event
2547             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
2548                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
2549             }
2550 
2551 #ifdef ENABLE_BLE
2552 #ifdef ENABLE_LE_PERIPHERAL
2553             // re-enable advertisements for le connections if active
2554             if (hci_is_le_connection(conn)){
2555                 hci_reenable_advertisements_if_needed();
2556             }
2557 #endif
2558 #endif
2559             break;
2560 
2561         case HCI_EVENT_HARDWARE_ERROR:
2562             log_error("Hardware Error: 0x%02x", packet[2]);
2563             if (hci_stack->hardware_error_callback){
2564                 (*hci_stack->hardware_error_callback)(packet[2]);
2565             } else {
2566                 // if no special requests, just reboot stack
2567                 hci_power_control_off();
2568                 hci_power_control_on();
2569             }
2570             break;
2571 
2572 #ifdef ENABLE_CLASSIC
2573         case HCI_EVENT_ROLE_CHANGE:
2574             if (packet[2]) break;   // status != 0
2575             reverse_bd_addr(&packet[3], addr);
2576             addr_type = BD_ADDR_TYPE_ACL;
2577             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2578             if (!conn) break;
2579             conn->role = packet[9];
2580             break;
2581 #endif
2582 
2583         case HCI_EVENT_TRANSPORT_PACKET_SENT:
2584             // release packet buffer only for asynchronous transport and if there are not further fragements
2585             if (hci_transport_synchronous()) {
2586                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
2587                 return; // instead of break: to avoid re-entering hci_run()
2588             }
2589             hci_stack->acl_fragmentation_tx_active = 0;
2590             if (hci_stack->acl_fragmentation_total_size) break;
2591             hci_release_packet_buffer();
2592 
2593             // L2CAP receives this event via the hci_emit_event below
2594 
2595 #ifdef ENABLE_CLASSIC
2596             // For SCO, we do the can_send_now_check here
2597             hci_notify_if_sco_can_send_now();
2598 #endif
2599             break;
2600 
2601 #ifdef ENABLE_CLASSIC
2602         case HCI_EVENT_SCO_CAN_SEND_NOW:
2603             // For SCO, we do the can_send_now_check here
2604             hci_stack->sco_can_send_now = 1;
2605             hci_notify_if_sco_can_send_now();
2606             return;
2607 
2608         // explode inquriy results for easier consumption
2609         case HCI_EVENT_INQUIRY_RESULT:
2610         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
2611         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
2612             gap_inquiry_explode(packet, size);
2613             break;
2614 #endif
2615 
2616 #ifdef ENABLE_BLE
2617         case HCI_EVENT_LE_META:
2618             switch (packet[2]){
2619 #ifdef ENABLE_LE_CENTRAL
2620                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
2621                     // log_info("advertising report received");
2622                     if (!hci_stack->le_scanning_enabled) break;
2623                     le_handle_advertisement_report(packet, size);
2624                     break;
2625 #endif
2626                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
2627                     // Connection management
2628                     reverse_bd_addr(&packet[8], addr);
2629                     addr_type = (bd_addr_type_t)packet[7];
2630                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2631                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2632 
2633 #ifdef ENABLE_LE_CENTRAL
2634                     // if auto-connect, remove from whitelist in both roles
2635                     if (hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST){
2636                         hci_remove_from_whitelist(addr_type, addr);
2637                     }
2638                     // handle error: error is reported only to the initiator -> outgoing connection
2639                     if (packet[3]){
2640 
2641                         // handle cancelled outgoing connection
2642                         // "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2643                         //  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2644                         //  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2645                         if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2646                             conn = gap_get_outgoing_connection();
2647                         }
2648 
2649                         // outgoing connection establishment is done
2650                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2651                         // remove entry
2652                         if (conn){
2653                             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2654                             btstack_memory_hci_connection_free( conn );
2655                         }
2656                         break;
2657                     }
2658 #endif
2659                     // on success, both hosts receive connection complete event
2660                     if (packet[6] == HCI_ROLE_MASTER){
2661 #ifdef ENABLE_LE_CENTRAL
2662                         // if we're master, it was an outgoing connection and we're done with it
2663                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2664 #endif
2665                     } else {
2666 #ifdef ENABLE_LE_PERIPHERAL
2667                         // if we're slave, it was an incoming connection, advertisements have stopped
2668                         hci_stack->le_advertisements_active = 0;
2669 #endif
2670                     }
2671                     // LE connections are auto-accepted, so just create a connection if there isn't one already
2672                     if (!conn){
2673                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2674                     }
2675                     // no memory, sorry.
2676                     if (!conn){
2677                         break;
2678                     }
2679 
2680                     conn->state = OPEN;
2681                     conn->role  = packet[6];
2682                     conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2683                     conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2684 
2685 #ifdef ENABLE_LE_PERIPHERAL
2686                     if (packet[6] == HCI_ROLE_SLAVE){
2687                         hci_reenable_advertisements_if_needed();
2688                     }
2689 #endif
2690 
2691                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2692 
2693                     // restart timer
2694                     // btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2695                     // btstack_run_loop_add_timer(&conn->timeout);
2696 
2697                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2698 
2699                     hci_emit_nr_connections_changed();
2700                     break;
2701 
2702                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
2703                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
2704                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
2705                     conn = hci_connection_for_handle(handle);
2706                     if (!conn) break;
2707                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
2708                     break;
2709 
2710                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
2711                     // connection
2712                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
2713                     conn = hci_connection_for_handle(handle);
2714                     if (conn) {
2715                         // read arguments
2716                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
2717                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
2718                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
2719                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
2720 
2721                         // validate against current connection parameter range
2722                         le_connection_parameter_range_t existing_range;
2723                         gap_get_connection_parameter_range(&existing_range);
2724                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
2725                         if (update_parameter){
2726                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
2727                             conn->le_conn_interval_min = le_conn_interval_min;
2728                             conn->le_conn_interval_max = le_conn_interval_max;
2729                             conn->le_conn_latency = le_conn_latency;
2730                             conn->le_supervision_timeout = le_supervision_timeout;
2731                         } else {
2732                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY;
2733                         }
2734                     }
2735                     break;
2736 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
2737                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
2738                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
2739                     conn = hci_connection_for_handle(handle);
2740                     if (conn) {
2741                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
2742                     }
2743                     break;
2744 #endif
2745                 default:
2746                     break;
2747             }
2748             break;
2749 #endif
2750         case HCI_EVENT_VENDOR_SPECIFIC:
2751             // Vendor specific commands often create vendor specific event instead of num completed packets
2752             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
2753             switch (hci_stack->manufacturer){
2754                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
2755                     hci_stack->num_cmd_packets = 1;
2756                     break;
2757                 default:
2758                     break;
2759             }
2760             break;
2761         default:
2762             break;
2763     }
2764 
2765     handle_event_for_current_stack_state(packet, size);
2766 
2767     // notify upper stack
2768 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
2769 
2770     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
2771     if (hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE){
2772         if (!packet[2]){
2773             handle = little_endian_read_16(packet, 3);
2774             hci_connection_t * aConn = hci_connection_for_handle(handle);
2775             if (aConn) {
2776                 // discard connection if app did not trigger a reconnect in the event handler
2777                 if (aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
2778                     hci_shutdown_connection(aConn);
2779                 }
2780             }
2781         }
2782     }
2783 
2784 	// execute main loop
2785 	hci_run();
2786 }
2787 
2788 #ifdef ENABLE_CLASSIC
2789 
2790 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
2791 static void sco_schedule_tx(hci_connection_t * conn);
2792 
2793 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
2794     log_debug("SCO TX Timeout");
2795     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
2796     hci_connection_t * conn = hci_connection_for_handle(con_handle);
2797     if (!conn) return;
2798 
2799     // trigger send
2800     conn->sco_tx_ready = 1;
2801     // extra packet if CVSD but SCO buffer is too short
2802     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
2803         conn->sco_tx_ready++;
2804     }
2805     hci_notify_if_sco_can_send_now();
2806 }
2807 
2808 
2809 #define SCO_TX_AFTER_RX_MS (6)
2810 
2811 static void sco_schedule_tx(hci_connection_t * conn){
2812 
2813     uint32_t now = btstack_run_loop_get_time_ms();
2814     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
2815     int time_delta_ms = sco_tx_ms - now;
2816 
2817     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
2818 
2819     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
2820     btstack_run_loop_set_timer(timer, time_delta_ms);
2821     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
2822     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
2823     btstack_run_loop_add_timer(timer);
2824 }
2825 
2826 static void sco_handler(uint8_t * packet, uint16_t size){
2827     // lookup connection struct
2828     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
2829     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
2830     if (!conn) return;
2831 
2832     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
2833     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
2834         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
2835             packet[2] = 0x3c;
2836             memmove(&packet[3], &packet[23], 63);
2837             size = 63;
2838         }
2839     }
2840 
2841     if (hci_have_usb_transport()){
2842         // Nothing to do
2843     } else {
2844         // 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);
2845         if (hci_stack->synchronous_flow_control_enabled == 0){
2846             uint32_t now = btstack_run_loop_get_time_ms();
2847 
2848             if (!conn->sco_rx_valid){
2849                 // ignore first 10 packets
2850                 conn->sco_rx_count++;
2851                 // log_debug("sco rx count %u", conn->sco_rx_count);
2852                 if (conn->sco_rx_count == 10) {
2853                     // use first timestamp as is and pretent it just started
2854                     conn->sco_rx_ms = now;
2855                     conn->sco_rx_valid = 1;
2856                     conn->sco_rx_count = 0;
2857                     sco_schedule_tx(conn);
2858                 }
2859             } else {
2860                 // track expected arrival timme
2861                 conn->sco_rx_count++;
2862                 conn->sco_rx_ms += 7;
2863                 int delta = (int32_t) (now - conn->sco_rx_ms);
2864                 if (delta > 0){
2865                     conn->sco_rx_ms++;
2866                 }
2867                 // log_debug("sco rx %u", conn->sco_rx_ms);
2868                 sco_schedule_tx(conn);
2869             }
2870         }
2871     }
2872     // deliver to app
2873     if (hci_stack->sco_packet_handler) {
2874         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
2875     }
2876 
2877 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
2878     conn->num_packets_completed++;
2879     hci_stack->host_completed_packets = 1;
2880     hci_run();
2881 #endif
2882 }
2883 #endif
2884 
2885 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
2886     hci_dump_packet(packet_type, 1, packet, size);
2887     switch (packet_type) {
2888         case HCI_EVENT_PACKET:
2889             event_handler(packet, size);
2890             break;
2891         case HCI_ACL_DATA_PACKET:
2892             acl_handler(packet, size);
2893             break;
2894 #ifdef ENABLE_CLASSIC
2895         case HCI_SCO_DATA_PACKET:
2896             sco_handler(packet, size);
2897             break;
2898 #endif
2899         default:
2900             break;
2901     }
2902 }
2903 
2904 /**
2905  * @brief Add event packet handler.
2906  */
2907 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
2908     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
2909 }
2910 
2911 
2912 /** Register HCI packet handlers */
2913 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
2914     hci_stack->acl_packet_handler = handler;
2915 }
2916 
2917 #ifdef ENABLE_CLASSIC
2918 /**
2919  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
2920  */
2921 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
2922     hci_stack->sco_packet_handler = handler;
2923 }
2924 #endif
2925 
2926 static void hci_state_reset(void){
2927     // no connections yet
2928     hci_stack->connections = NULL;
2929 
2930     // keep discoverable/connectable as this has been requested by the client(s)
2931     // hci_stack->discoverable = 0;
2932     // hci_stack->connectable = 0;
2933     // hci_stack->bondable = 1;
2934     // hci_stack->own_addr_type = 0;
2935 
2936     // buffer is free
2937     hci_stack->hci_packet_buffer_reserved = 0;
2938 
2939     // no pending cmds
2940     hci_stack->decline_reason = 0;
2941     hci_stack->new_scan_enable_value = 0xff;
2942 
2943     // LE
2944 #ifdef ENABLE_BLE
2945     memset(hci_stack->le_random_address, 0, 6);
2946     hci_stack->le_random_address_set = 0;
2947 #endif
2948 #ifdef ENABLE_LE_CENTRAL
2949     hci_stack->le_scanning_active  = 0;
2950     hci_stack->le_scan_type = 0xff;
2951     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2952     hci_stack->le_whitelist = 0;
2953     hci_stack->le_whitelist_capacity = 0;
2954 #endif
2955 }
2956 
2957 #ifdef ENABLE_CLASSIC
2958 /**
2959  * @brief Configure Bluetooth hardware control. Has to be called before power on.
2960  */
2961 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
2962     // store and open remote device db
2963     hci_stack->link_key_db = link_key_db;
2964     if (hci_stack->link_key_db) {
2965         hci_stack->link_key_db->open();
2966     }
2967 }
2968 #endif
2969 
2970 void hci_init(const hci_transport_t *transport, const void *config){
2971 
2972 #ifdef HAVE_MALLOC
2973     if (!hci_stack) {
2974         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
2975     }
2976 #else
2977     hci_stack = &hci_stack_static;
2978 #endif
2979     memset(hci_stack, 0, sizeof(hci_stack_t));
2980 
2981     // reference to use transport layer implementation
2982     hci_stack->hci_transport = transport;
2983 
2984     // reference to used config
2985     hci_stack->config = config;
2986 
2987     // setup pointer for outgoing packet buffer
2988     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
2989 
2990     // max acl payload size defined in config.h
2991     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
2992 
2993     // register packet handlers with transport
2994     transport->register_packet_handler(&packet_handler);
2995 
2996     hci_stack->state = HCI_STATE_OFF;
2997 
2998     // class of device
2999     hci_stack->class_of_device = 0x007a020c; // Smartphone
3000 
3001     // bondable by default
3002     hci_stack->bondable = 1;
3003 
3004 #ifdef ENABLE_CLASSIC
3005     // classic name
3006     hci_stack->local_name = default_classic_name;
3007 
3008     // Master slave policy
3009     hci_stack->master_slave_policy = 1;
3010 
3011     // Allow Role Switch
3012     hci_stack->allow_role_switch = 1;
3013 
3014     // Default / minimum security level = 2
3015     hci_stack->gap_security_level = LEVEL_2;
3016 
3017     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3, we use 16 as default
3018     hci_stack->gap_required_encyrption_key_size = 16;
3019 #endif
3020 
3021     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3022     hci_stack->ssp_enable = 1;
3023     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3024     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3025     hci_stack->ssp_auto_accept = 1;
3026 
3027     // Secure Connections: enable (requires support from Controller)
3028     hci_stack->secure_connections_enable = true;
3029 
3030     // voice setting - signed 16 bit pcm data with CVSD over the air
3031     hci_stack->sco_voice_setting = 0x60;
3032 
3033 #ifdef ENABLE_LE_CENTRAL
3034     // connection parameter to use for outgoing connections
3035     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3036     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3037     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3038     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3039     hci_stack->le_connection_latency      = 4;         // 4
3040     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3041     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3042     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3043 
3044     // default LE Scanning
3045     hci_stack->le_scan_interval = 0x1e0;
3046     hci_stack->le_scan_window   =  0x30;
3047 #endif
3048 
3049 #ifdef ENABLE_LE_PERIPHERAL
3050     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3051 #endif
3052 
3053     // connection parameter range used to answer connection parameter update requests in l2cap
3054     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3055     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3056     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3057     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3058     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3059     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3060 
3061     hci_state_reset();
3062 }
3063 
3064 /**
3065  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3066  */
3067 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3068     hci_stack->chipset = chipset_driver;
3069 
3070     // reset chipset driver - init is also called on power_up
3071     if (hci_stack->chipset && hci_stack->chipset->init){
3072         hci_stack->chipset->init(hci_stack->config);
3073     }
3074 }
3075 
3076 /**
3077  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3078  */
3079 void hci_set_control(const btstack_control_t *hardware_control){
3080     // references to used control implementation
3081     hci_stack->control = hardware_control;
3082     // init with transport config
3083     hardware_control->init(hci_stack->config);
3084 }
3085 
3086 void hci_close(void){
3087     // close remote device db
3088     if (hci_stack->link_key_db) {
3089         hci_stack->link_key_db->close();
3090     }
3091 
3092     btstack_linked_list_iterator_t lit;
3093     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3094     while (btstack_linked_list_iterator_has_next(&lit)){
3095         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3096         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3097         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3098         hci_shutdown_connection(connection);
3099     }
3100 
3101     hci_power_control(HCI_POWER_OFF);
3102 
3103 #ifdef HAVE_MALLOC
3104     free(hci_stack);
3105 #endif
3106     hci_stack = NULL;
3107 }
3108 
3109 #ifdef ENABLE_CLASSIC
3110 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3111     // validate ranage and set
3112     if (encryption_key_size < 7)  return;
3113     if (encryption_key_size > 16) return;
3114     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3115 }
3116 
3117 void gap_set_security_level(gap_security_level_t security_level){
3118     hci_stack->gap_security_level = security_level;
3119 }
3120 
3121 gap_security_level_t gap_get_security_level(void){
3122     return hci_stack->gap_security_level;
3123 }
3124 #endif
3125 
3126 #ifdef ENABLE_CLASSIC
3127 void gap_set_class_of_device(uint32_t class_of_device){
3128     hci_stack->class_of_device = class_of_device;
3129 }
3130 
3131 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3132     hci_stack->default_link_policy_settings = default_link_policy_settings;
3133 }
3134 
3135 void gap_set_allow_role_switch(bool allow_role_switch){
3136     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3137 }
3138 
3139 uint8_t hci_get_allow_role_switch(void){
3140     return  hci_stack->allow_role_switch;
3141 }
3142 
3143 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3144     hci_stack->link_supervision_timeout = link_supervision_timeout;
3145 }
3146 
3147 void hci_disable_l2cap_timeout_check(void){
3148     disable_l2cap_timeouts = 1;
3149 }
3150 #endif
3151 
3152 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
3153 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3154 void hci_set_bd_addr(bd_addr_t addr){
3155     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3156     hci_stack->custom_bd_addr_set = 1;
3157 }
3158 #endif
3159 
3160 // State-Module-Driver overview
3161 // state                    module  low-level
3162 // HCI_STATE_OFF             off      close
3163 // HCI_STATE_INITIALIZING,   on       open
3164 // HCI_STATE_WORKING,        on       open
3165 // HCI_STATE_HALTING,        on       open
3166 // HCI_STATE_SLEEPING,    off/sleep   close
3167 // HCI_STATE_FALLING_ASLEEP  on       open
3168 
3169 static int hci_power_control_on(void){
3170 
3171     // power on
3172     int err = 0;
3173     if (hci_stack->control && hci_stack->control->on){
3174         err = (*hci_stack->control->on)();
3175     }
3176     if (err){
3177         log_error( "POWER_ON failed");
3178         hci_emit_hci_open_failed();
3179         return err;
3180     }
3181 
3182     // int chipset driver
3183     if (hci_stack->chipset && hci_stack->chipset->init){
3184         hci_stack->chipset->init(hci_stack->config);
3185     }
3186 
3187     // init transport
3188     if (hci_stack->hci_transport->init){
3189         hci_stack->hci_transport->init(hci_stack->config);
3190     }
3191 
3192     // open transport
3193     err = hci_stack->hci_transport->open();
3194     if (err){
3195         log_error( "HCI_INIT failed, turning Bluetooth off again");
3196         if (hci_stack->control && hci_stack->control->off){
3197             (*hci_stack->control->off)();
3198         }
3199         hci_emit_hci_open_failed();
3200         return err;
3201     }
3202     return 0;
3203 }
3204 
3205 static void hci_power_control_off(void){
3206 
3207     log_info("hci_power_control_off");
3208 
3209     // close low-level device
3210     hci_stack->hci_transport->close();
3211 
3212     log_info("hci_power_control_off - hci_transport closed");
3213 
3214     // power off
3215     if (hci_stack->control && hci_stack->control->off){
3216         (*hci_stack->control->off)();
3217     }
3218 
3219     log_info("hci_power_control_off - control closed");
3220 
3221     hci_stack->state = HCI_STATE_OFF;
3222 }
3223 
3224 static void hci_power_control_sleep(void){
3225 
3226     log_info("hci_power_control_sleep");
3227 
3228 #if 0
3229     // don't close serial port during sleep
3230 
3231     // close low-level device
3232     hci_stack->hci_transport->close(hci_stack->config);
3233 #endif
3234 
3235     // sleep mode
3236     if (hci_stack->control && hci_stack->control->sleep){
3237         (*hci_stack->control->sleep)();
3238     }
3239 
3240     hci_stack->state = HCI_STATE_SLEEPING;
3241 }
3242 
3243 static int hci_power_control_wake(void){
3244 
3245     log_info("hci_power_control_wake");
3246 
3247     // wake on
3248     if (hci_stack->control && hci_stack->control->wake){
3249         (*hci_stack->control->wake)();
3250     }
3251 
3252 #if 0
3253     // open low-level device
3254     int err = hci_stack->hci_transport->open(hci_stack->config);
3255     if (err){
3256         log_error( "HCI_INIT failed, turning Bluetooth off again");
3257         if (hci_stack->control && hci_stack->control->off){
3258             (*hci_stack->control->off)();
3259         }
3260         hci_emit_hci_open_failed();
3261         return err;
3262     }
3263 #endif
3264 
3265     return 0;
3266 }
3267 
3268 static void hci_power_transition_to_initializing(void){
3269     // set up state machine
3270     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3271     hci_stack->hci_packet_buffer_reserved = 0;
3272     hci_stack->state = HCI_STATE_INITIALIZING;
3273     hci_stack->substate = HCI_INIT_SEND_RESET;
3274 }
3275 
3276 int hci_power_control(HCI_POWER_MODE power_mode){
3277 
3278     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
3279 
3280     int err = 0;
3281     switch (hci_stack->state){
3282 
3283         case HCI_STATE_OFF:
3284             switch (power_mode){
3285                 case HCI_POWER_ON:
3286                     err = hci_power_control_on();
3287                     if (err) {
3288                         log_error("hci_power_control_on() error %d", err);
3289                         return err;
3290                     }
3291                     hci_power_transition_to_initializing();
3292                     break;
3293                 case HCI_POWER_OFF:
3294                     // do nothing
3295                     break;
3296                 case HCI_POWER_SLEEP:
3297                     // do nothing (with SLEEP == OFF)
3298                     break;
3299             }
3300             break;
3301 
3302         case HCI_STATE_INITIALIZING:
3303             switch (power_mode){
3304                 case HCI_POWER_ON:
3305                     // do nothing
3306                     break;
3307                 case HCI_POWER_OFF:
3308                     // no connections yet, just turn it off
3309                     hci_power_control_off();
3310                     break;
3311                 case HCI_POWER_SLEEP:
3312                     // no connections yet, just turn it off
3313                     hci_power_control_sleep();
3314                     break;
3315             }
3316             break;
3317 
3318         case HCI_STATE_WORKING:
3319             switch (power_mode){
3320                 case HCI_POWER_ON:
3321                     // do nothing
3322                     break;
3323                 case HCI_POWER_OFF:
3324                     // see hci_run
3325                     hci_stack->state = HCI_STATE_HALTING;
3326                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3327                     break;
3328                 case HCI_POWER_SLEEP:
3329                     // see hci_run
3330                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3331                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3332                     break;
3333             }
3334             break;
3335 
3336         case HCI_STATE_HALTING:
3337             switch (power_mode){
3338                 case HCI_POWER_ON:
3339                     hci_power_transition_to_initializing();
3340                     break;
3341                 case HCI_POWER_OFF:
3342                     // do nothing
3343                     break;
3344                 case HCI_POWER_SLEEP:
3345                     // see hci_run
3346                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3347                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3348                     break;
3349             }
3350             break;
3351 
3352         case HCI_STATE_FALLING_ASLEEP:
3353             switch (power_mode){
3354                 case HCI_POWER_ON:
3355 
3356 #ifdef HAVE_PLATFORM_IPHONE_OS
3357                     // nothing to do, if H4 supports power management
3358                     if (btstack_control_iphone_power_management_enabled()){
3359                         hci_stack->state = HCI_STATE_INITIALIZING;
3360                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
3361                         break;
3362                     }
3363 #endif
3364                     hci_power_transition_to_initializing();
3365                     break;
3366                 case HCI_POWER_OFF:
3367                     // see hci_run
3368                     hci_stack->state = HCI_STATE_HALTING;
3369                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3370                     break;
3371                 case HCI_POWER_SLEEP:
3372                     // do nothing
3373                     break;
3374             }
3375             break;
3376 
3377         case HCI_STATE_SLEEPING:
3378             switch (power_mode){
3379                 case HCI_POWER_ON:
3380 
3381 #ifdef HAVE_PLATFORM_IPHONE_OS
3382                     // nothing to do, if H4 supports power management
3383                     if (btstack_control_iphone_power_management_enabled()){
3384                         hci_stack->state = HCI_STATE_INITIALIZING;
3385                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
3386                         hci_update_scan_enable();
3387                         break;
3388                     }
3389 #endif
3390                     err = hci_power_control_wake();
3391                     if (err) return err;
3392                     hci_power_transition_to_initializing();
3393                     break;
3394                 case HCI_POWER_OFF:
3395                     hci_stack->state = HCI_STATE_HALTING;
3396                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3397                     break;
3398                 case HCI_POWER_SLEEP:
3399                     // do nothing
3400                     break;
3401             }
3402             break;
3403     }
3404 
3405     // create internal event
3406 	hci_emit_state();
3407 
3408 	// trigger next/first action
3409 	hci_run();
3410 
3411     return 0;
3412 }
3413 
3414 
3415 #ifdef ENABLE_CLASSIC
3416 
3417 static void hci_update_scan_enable(void){
3418     // 2 = page scan, 1 = inq scan
3419     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
3420     hci_run();
3421 }
3422 
3423 void gap_discoverable_control(uint8_t enable){
3424     if (enable) enable = 1; // normalize argument
3425 
3426     if (hci_stack->discoverable == enable){
3427         hci_emit_discoverable_enabled(hci_stack->discoverable);
3428         return;
3429     }
3430 
3431     hci_stack->discoverable = enable;
3432     hci_update_scan_enable();
3433 }
3434 
3435 void gap_connectable_control(uint8_t enable){
3436     if (enable) enable = 1; // normalize argument
3437 
3438     // don't emit event
3439     if (hci_stack->connectable == enable) return;
3440 
3441     hci_stack->connectable = enable;
3442     hci_update_scan_enable();
3443 }
3444 #endif
3445 
3446 void gap_local_bd_addr(bd_addr_t address_buffer){
3447     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
3448 }
3449 
3450 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3451 static void hci_host_num_completed_packets(void){
3452 
3453     // create packet manually as arrays are not supported and num_commands should not get reduced
3454     hci_reserve_packet_buffer();
3455     uint8_t * packet = hci_get_outgoing_packet_buffer();
3456 
3457     uint16_t size = 0;
3458     uint16_t num_handles = 0;
3459     packet[size++] = 0x35;
3460     packet[size++] = 0x0c;
3461     size++;  // skip param len
3462     size++;  // skip num handles
3463 
3464     // add { handle, packets } entries
3465     btstack_linked_item_t * it;
3466     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3467         hci_connection_t * connection = (hci_connection_t *) it;
3468         if (connection->num_packets_completed){
3469             little_endian_store_16(packet, size, connection->con_handle);
3470             size += 2;
3471             little_endian_store_16(packet, size, connection->num_packets_completed);
3472             size += 2;
3473             //
3474             num_handles++;
3475             connection->num_packets_completed = 0;
3476         }
3477     }
3478 
3479     packet[2] = size - 3;
3480     packet[3] = num_handles;
3481 
3482     hci_stack->host_completed_packets = 0;
3483 
3484     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
3485     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
3486 
3487     // release packet buffer for synchronous transport implementations
3488     if (hci_transport_synchronous()){
3489         hci_release_packet_buffer();
3490         hci_emit_transport_packet_sent();
3491     }
3492 }
3493 #endif
3494 
3495 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
3496     UNUSED(ds);
3497     hci_stack->substate = HCI_HALTING_CLOSE;
3498     // allow packet handlers to defer final shutdown
3499     hci_emit_state();
3500     hci_run();
3501 }
3502 
3503 static bool hci_run_acl_fragments(void){
3504     if (hci_stack->acl_fragmentation_total_size > 0) {
3505         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
3506         hci_connection_t *connection = hci_connection_for_handle(con_handle);
3507         if (connection) {
3508             if (hci_can_send_prepared_acl_packet_now(con_handle)){
3509                 hci_send_acl_packet_fragments(connection);
3510                 return true;
3511             }
3512         } else {
3513             // connection gone -> discard further fragments
3514             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
3515             hci_stack->acl_fragmentation_total_size = 0;
3516             hci_stack->acl_fragmentation_pos = 0;
3517         }
3518     }
3519     return false;
3520 }
3521 
3522 #ifdef ENABLE_CLASSIC
3523 static bool hci_run_general_gap_classic(void){
3524 
3525     // decline incoming connections
3526     if (hci_stack->decline_reason){
3527         uint8_t reason = hci_stack->decline_reason;
3528         hci_stack->decline_reason = 0;
3529         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
3530         return true;
3531     }
3532     // send scan enable
3533     if ((hci_stack->state == HCI_STATE_WORKING) && (hci_stack->new_scan_enable_value != 0xff) && hci_classic_supported()){
3534         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
3535         hci_stack->new_scan_enable_value = 0xff;
3536         return true;
3537     }
3538     // start/stop inquiry
3539     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
3540         uint8_t duration = hci_stack->inquiry_state;
3541         hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
3542         hci_send_cmd(&hci_inquiry, GAP_IAC_GENERAL_INQUIRY, duration, 0);
3543         return true;
3544     }
3545     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
3546         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
3547         hci_send_cmd(&hci_inquiry_cancel);
3548         return true;
3549     }
3550     // remote name request
3551     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
3552         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
3553         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
3554                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
3555         return true;
3556     }
3557     // pairing
3558     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
3559         uint8_t state = hci_stack->gap_pairing_state;
3560         hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
3561         switch (state){
3562             case GAP_PAIRING_STATE_SEND_PIN:
3563                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, strlen(hci_stack->gap_pairing_input.gap_pairing_pin), hci_stack->gap_pairing_input.gap_pairing_pin);
3564                 break;
3565             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
3566                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
3567                 break;
3568             case GAP_PAIRING_STATE_SEND_PASSKEY:
3569                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
3570                 break;
3571             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
3572                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
3573                 break;
3574             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
3575                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
3576                 break;
3577             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
3578                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
3579                 break;
3580             default:
3581                 break;
3582         }
3583         return true;
3584     }
3585     return false;
3586 }
3587 #endif
3588 
3589 #ifdef ENABLE_BLE
3590 static bool hci_run_general_gap_le(void){
3591 
3592     // advertisements, active scanning, and creating connections requires random address to be set if using private address
3593 
3594     if (hci_stack->state != HCI_STATE_WORKING) return false;
3595     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0) ) return false;
3596 
3597 #ifdef ENABLE_LE_CENTRAL
3598     // parameter change requires scanning to be stopped first
3599     if (hci_stack->le_scan_type != 0xff) {
3600         if (hci_stack->le_scanning_active){
3601             hci_stack->le_scanning_active = 0;
3602             hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
3603         } else {
3604             int scan_type = (int) hci_stack->le_scan_type;
3605             hci_stack->le_scan_type = 0xff;
3606             hci_send_cmd(&hci_le_set_scan_parameters, scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->le_own_addr_type, 0);
3607         }
3608         return true;
3609     }
3610     // finally, we can enable/disable le scan
3611     if ((hci_stack->le_scanning_enabled != hci_stack->le_scanning_active)){
3612         hci_stack->le_scanning_active = hci_stack->le_scanning_enabled;
3613         hci_send_cmd(&hci_le_set_scan_enable, hci_stack->le_scanning_enabled, 0);
3614         return true;
3615     }
3616 #endif
3617 #ifdef ENABLE_LE_PERIPHERAL
3618     // le advertisement control
3619     if (hci_stack->le_advertisements_todo){
3620         log_info("hci_run: gap_le: adv todo: %x", hci_stack->le_advertisements_todo );
3621     }
3622     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_DISABLE){
3623         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_DISABLE;
3624         hci_send_cmd(&hci_le_set_advertise_enable, 0);
3625         return true;
3626     }
3627     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
3628         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3629         hci_send_cmd(&hci_le_set_advertising_parameters,
3630                      hci_stack->le_advertisements_interval_min,
3631                      hci_stack->le_advertisements_interval_max,
3632                      hci_stack->le_advertisements_type,
3633                      hci_stack->le_own_addr_type,
3634                      hci_stack->le_advertisements_direct_address_type,
3635                      hci_stack->le_advertisements_direct_address,
3636                      hci_stack->le_advertisements_channel_map,
3637                      hci_stack->le_advertisements_filter_policy);
3638         return true;
3639     }
3640     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
3641         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3642         uint8_t adv_data_clean[31];
3643         memset(adv_data_clean, 0, sizeof(adv_data_clean));
3644         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
3645                      hci_stack->le_advertisements_data_len);
3646         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
3647         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
3648         return true;
3649     }
3650     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
3651         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
3652         uint8_t scan_data_clean[31];
3653         memset(scan_data_clean, 0, sizeof(scan_data_clean));
3654         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
3655                      hci_stack->le_scan_response_data_len);
3656         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
3657         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
3658         return true;
3659     }
3660     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_ENABLE){
3661         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_ENABLE;
3662         hci_send_cmd(&hci_le_set_advertise_enable, 1);
3663         return true;
3664     }
3665 #endif
3666 
3667 #ifdef ENABLE_LE_CENTRAL
3668     //
3669     // LE Whitelist Management
3670     //
3671 
3672     // check if whitelist needs modification
3673     btstack_linked_list_iterator_t lit;
3674     int modification_pending = 0;
3675     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3676     while (btstack_linked_list_iterator_has_next(&lit)){
3677         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3678         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
3679             modification_pending = 1;
3680             break;
3681         }
3682     }
3683 
3684     if (modification_pending){
3685         // stop connnecting if modification pending
3686         if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
3687             hci_send_cmd(&hci_le_create_connection_cancel);
3688             return true;
3689         }
3690 
3691         // add/remove entries
3692         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3693         while (btstack_linked_list_iterator_has_next(&lit)){
3694             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3695             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
3696                 entry->state = LE_WHITELIST_ON_CONTROLLER;
3697                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
3698                 return true;
3699             }
3700             if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
3701                 bd_addr_t address;
3702                 bd_addr_type_t address_type = entry->address_type;
3703                 (void)memcpy(address, entry->address, 6);
3704                 btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
3705                 btstack_memory_whitelist_entry_free(entry);
3706                 hci_send_cmd(&hci_le_remove_device_from_white_list, address_type, address);
3707                 return true;
3708             }
3709         }
3710     }
3711 
3712     // start connecting
3713     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) &&
3714          !btstack_linked_list_empty(&hci_stack->le_whitelist)){
3715         bd_addr_t null_addr;
3716         memset(null_addr, 0, 6);
3717         hci_send_cmd(&hci_le_create_connection,
3718                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
3719                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
3720                      1,         // use whitelist
3721                      0,         // peer address type
3722                      null_addr, // peer bd addr
3723                      hci_stack->le_own_addr_type, // our addr type:
3724                      hci_stack->le_connection_interval_min,    // conn interval min
3725                      hci_stack->le_connection_interval_max,    // conn interval max
3726                      hci_stack->le_connection_latency,         // conn latency
3727                      hci_stack->le_supervision_timeout,        // conn latency
3728                      hci_stack->le_minimum_ce_length,          // min ce length
3729                      hci_stack->le_maximum_ce_length           // max ce length
3730         );
3731         return true;
3732     }
3733 #endif
3734     return false;
3735 }
3736 #endif
3737 
3738 static bool hci_run_general_pending_commmands(void){
3739     btstack_linked_item_t * it;
3740     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
3741         hci_connection_t * connection = (hci_connection_t *) it;
3742 
3743         switch(connection->state){
3744             case SEND_CREATE_CONNECTION:
3745                 switch(connection->address_type){
3746 #ifdef ENABLE_CLASSIC
3747                     case BD_ADDR_TYPE_ACL:
3748                         log_info("sending hci_create_connection");
3749                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
3750                         break;
3751 #endif
3752                     default:
3753 #ifdef ENABLE_BLE
3754 #ifdef ENABLE_LE_CENTRAL
3755                         // track outgoing connection
3756                         hci_stack->outgoing_addr_type = connection->address_type;
3757                         (void)memcpy(hci_stack->outgoing_addr,
3758                                      connection->address, 6);
3759                         log_info("sending hci_le_create_connection");
3760                         hci_send_cmd(&hci_le_create_connection,
3761                                      hci_stack->le_connection_scan_interval,    // conn scan interval
3762                                      hci_stack->le_connection_scan_window,      // conn scan windows
3763                                      0,         // don't use whitelist
3764                                      connection->address_type, // peer address type
3765                                      connection->address,      // peer bd addr
3766                                      hci_stack->le_own_addr_type, // our addr type:
3767                                      hci_stack->le_connection_interval_min,    // conn interval min
3768                                      hci_stack->le_connection_interval_max,    // conn interval max
3769                                      hci_stack->le_connection_latency,         // conn latency
3770                                      hci_stack->le_supervision_timeout,        // conn latency
3771                                      hci_stack->le_minimum_ce_length,          // min ce length
3772                                      hci_stack->le_maximum_ce_length          // max ce length
3773                         );
3774                         connection->state = SENT_CREATE_CONNECTION;
3775 #endif
3776 #endif
3777                         break;
3778                 }
3779                 return true;
3780 
3781 #ifdef ENABLE_CLASSIC
3782             case RECEIVED_CONNECTION_REQUEST:
3783                 connection->role  = HCI_ROLE_SLAVE;
3784                 if (connection->address_type == BD_ADDR_TYPE_ACL){
3785                     log_info("sending hci_accept_connection_request");
3786                     connection->state = ACCEPTED_CONNECTION_REQUEST;
3787                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
3788                 }
3789                 return true;
3790 #endif
3791 
3792 #ifdef ENABLE_BLE
3793 #ifdef ENABLE_LE_CENTRAL
3794             case SEND_CANCEL_CONNECTION:
3795                 connection->state = SENT_CANCEL_CONNECTION;
3796                 hci_send_cmd(&hci_le_create_connection_cancel);
3797                 return true;
3798 #endif
3799 #endif
3800             case SEND_DISCONNECT:
3801                 connection->state = SENT_DISCONNECT;
3802                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3803                 return true;
3804 
3805             default:
3806                 break;
3807         }
3808 
3809         // no further commands if connection is about to get shut down
3810         if (connection->state == SENT_DISCONNECT) continue;
3811 
3812         if (connection->authentication_flags & READ_RSSI){
3813             connectionClearAuthenticationFlags(connection, READ_RSSI);
3814             hci_send_cmd(&hci_read_rssi, connection->con_handle);
3815             return true;
3816         }
3817 
3818 #ifdef ENABLE_CLASSIC
3819 
3820         if (connection->authentication_flags & WRITE_SUPERVISION_TIMEOUT){
3821             connectionClearAuthenticationFlags(connection, WRITE_SUPERVISION_TIMEOUT);
3822             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
3823             return true;
3824         }
3825 
3826         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
3827             log_info("responding to link key request");
3828             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
3829 
3830             link_key_t link_key;
3831             link_key_type_t link_key_type;
3832             bool have_link_key = hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type);
3833 
3834             const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
3835             bool sc_enabled_remote = (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
3836             bool sc_downgrade = have_link_key && (gap_secure_connection_for_link_key_type(link_key_type) == 1) && !sc_enabled_remote;
3837             if (sc_downgrade){
3838                 log_info("Link key based on SC, but remote does not support SC -> disconnect");
3839                 connection->state = SENT_DISCONNECT;
3840                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
3841                 return true;
3842             }
3843 
3844             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level);
3845             if (have_link_key && security_level_sufficient){
3846                 connection->link_key_type = link_key_type;
3847                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
3848             } else {
3849                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
3850             }
3851             return true;
3852         }
3853 
3854         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
3855             log_info("denying to pin request");
3856             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
3857             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
3858             return true;
3859         }
3860 
3861         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
3862             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
3863             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
3864             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
3865                 // tweak authentication requirements
3866                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
3867                 if (connection->bonding_flags & BONDING_DEDICATED){
3868                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
3869                 }
3870                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
3871                     authreq |= 1;
3872                 }
3873                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
3874             } else {
3875                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
3876             }
3877             return true;
3878         }
3879 
3880         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
3881             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
3882             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
3883             return true;
3884         }
3885 
3886         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
3887             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
3888             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
3889             return true;
3890         }
3891 
3892         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
3893             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
3894             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
3895             return true;
3896         }
3897 
3898         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
3899             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
3900             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
3901             return true;
3902         }
3903 
3904         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
3905             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
3906             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
3907             return true;
3908         }
3909 
3910         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
3911             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
3912             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
3913             connection->state = SENT_DISCONNECT;
3914             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3915             return true;
3916         }
3917 
3918         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
3919             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
3920             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
3921             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
3922             return true;
3923         }
3924 
3925         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
3926             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
3927             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
3928             return true;
3929         }
3930         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
3931             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3932             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
3933             return true;
3934         }
3935 #endif
3936 
3937         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
3938             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
3939             if (connection->state != SENT_DISCONNECT){
3940                 connection->state = SENT_DISCONNECT;
3941                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
3942                 return true;
3943             }
3944         }
3945 
3946 #ifdef ENABLE_CLASSIC
3947         uint16_t sniff_min_interval;
3948         switch (connection->sniff_min_interval){
3949             case 0:
3950                 break;
3951             case 0xffff:
3952                 connection->sniff_min_interval = 0;
3953                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
3954                 return true;
3955             default:
3956                 sniff_min_interval = connection->sniff_min_interval;
3957                 connection->sniff_min_interval = 0;
3958                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
3959                 return true;
3960         }
3961 #endif
3962 
3963 #ifdef ENABLE_BLE
3964         switch (connection->le_con_parameter_update_state){
3965             // response to L2CAP CON PARAMETER UPDATE REQUEST
3966             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
3967                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
3968                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
3969                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
3970                              0x0000, 0xffff);
3971                 return true;
3972             case CON_PARAMETER_UPDATE_REPLY:
3973                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
3974                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
3975                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
3976                              0x0000, 0xffff);
3977                 return true;
3978             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
3979                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
3980                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
3981                 return true;
3982             default:
3983                 break;
3984         }
3985         if (connection->le_phy_update_all_phys != 0xff){
3986             uint8_t all_phys = connection->le_phy_update_all_phys;
3987             connection->le_phy_update_all_phys = 0xff;
3988             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);
3989             return true;
3990         }
3991 #endif
3992     }
3993     return false;
3994 }
3995 
3996 static void hci_run(void){
3997 
3998     bool done;
3999 
4000     // send continuation fragments first, as they block the prepared packet buffer
4001     done = hci_run_acl_fragments();
4002     if (done) return;
4003 
4004 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4005     // send host num completed packets next as they don't require num_cmd_packets > 0
4006     if (!hci_can_send_comand_packet_transport()) return;
4007     if (hci_stack->host_completed_packets){
4008         hci_host_num_completed_packets();
4009         return;
4010     }
4011 #endif
4012 
4013     if (!hci_can_send_command_packet_now()) return;
4014 
4015     // global/non-connection oriented commands
4016 
4017 
4018 #ifdef ENABLE_CLASSIC
4019     // general gap classic
4020     done = hci_run_general_gap_classic();
4021     if (done) return;
4022 #endif
4023 
4024 #ifdef ENABLE_BLE
4025     // general gap le
4026     done = hci_run_general_gap_le();
4027     if (done) return;
4028 #endif
4029 
4030     // send pending HCI commands
4031     done = hci_run_general_pending_commmands();
4032     if (done) return;
4033 
4034     // stack state sub statemachines
4035     hci_connection_t * connection;
4036     switch (hci_stack->state){
4037         case HCI_STATE_INITIALIZING:
4038             hci_initializing_run();
4039             break;
4040 
4041         case HCI_STATE_HALTING:
4042 
4043             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4044             switch (hci_stack->substate){
4045                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4046                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
4047 
4048 #ifdef ENABLE_BLE
4049 #ifdef ENABLE_LE_CENTRAL
4050                     // free whitelist entries
4051                     {
4052                         btstack_linked_list_iterator_t lit;
4053                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4054                         while (btstack_linked_list_iterator_has_next(&lit)){
4055                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4056                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4057                             btstack_memory_whitelist_entry_free(entry);
4058                         }
4059                     }
4060 #endif
4061 #endif
4062                     // close all open connections
4063                     connection =  (hci_connection_t *) hci_stack->connections;
4064                     if (connection){
4065                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
4066                         if (!hci_can_send_command_packet_now()) return;
4067 
4068                         // check state
4069                         if (connection->state == SENT_DISCONNECT) return;
4070                         connection->state = SENT_DISCONNECT;
4071 
4072                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
4073 
4074                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
4075                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
4076 
4077                         // ... which would be ignored anyway as we shutdown (free) the connection now
4078                         hci_shutdown_connection(connection);
4079 
4080                         // finally, send the disconnect command
4081                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4082                         return;
4083                     }
4084 
4085                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
4086                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
4087                         log_info("HCI_STATE_HALTING: wait 50 ms");
4088                         hci_stack->substate = HCI_HALTING_W4_TIMER;
4089                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
4090                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
4091                         btstack_run_loop_add_timer(&hci_stack->timeout);
4092                         break;
4093                     }
4094 
4095                     /* fall through */
4096 
4097                 case HCI_HALTING_CLOSE:
4098                     log_info("HCI_STATE_HALTING, calling off");
4099 
4100                     // switch mode
4101                     hci_power_control_off();
4102 
4103                     log_info("HCI_STATE_HALTING, emitting state");
4104                     hci_emit_state();
4105                     log_info("HCI_STATE_HALTING, done");
4106                     break;
4107 
4108                 case HCI_HALTING_W4_TIMER:
4109                     // keep waiting
4110 
4111                     break;
4112                 default:
4113                     break;
4114             }
4115 
4116             break;
4117 
4118         case HCI_STATE_FALLING_ASLEEP:
4119             switch(hci_stack->substate) {
4120                 case HCI_FALLING_ASLEEP_DISCONNECT:
4121                     log_info("HCI_STATE_FALLING_ASLEEP");
4122                     // close all open connections
4123                     connection =  (hci_connection_t *) hci_stack->connections;
4124 
4125 #ifdef HAVE_PLATFORM_IPHONE_OS
4126                     // don't close connections, if H4 supports power management
4127                     if (btstack_control_iphone_power_management_enabled()){
4128                         connection = NULL;
4129                     }
4130 #endif
4131                     if (connection){
4132 
4133                         // send disconnect
4134                         if (!hci_can_send_command_packet_now()) return;
4135 
4136                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
4137                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4138 
4139                         // send disconnected event right away - causes higher layer connections to get closed, too.
4140                         hci_shutdown_connection(connection);
4141                         return;
4142                     }
4143 
4144                     if (hci_classic_supported()){
4145                         // disable page and inquiry scan
4146                         if (!hci_can_send_command_packet_now()) return;
4147 
4148                         log_info("HCI_STATE_HALTING, disabling inq scans");
4149                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
4150 
4151                         // continue in next sub state
4152                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
4153                         break;
4154                     }
4155 
4156                     /* fall through */
4157 
4158                 case HCI_FALLING_ASLEEP_COMPLETE:
4159                     log_info("HCI_STATE_HALTING, calling sleep");
4160 #ifdef HAVE_PLATFORM_IPHONE_OS
4161                     // don't actually go to sleep, if H4 supports power management
4162                     if (btstack_control_iphone_power_management_enabled()){
4163                         // SLEEP MODE reached
4164                         hci_stack->state = HCI_STATE_SLEEPING;
4165                         hci_emit_state();
4166                         break;
4167                     }
4168 #endif
4169                     // switch mode
4170                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
4171                     hci_emit_state();
4172                     break;
4173 
4174                 default:
4175                     break;
4176             }
4177             break;
4178 
4179         default:
4180             break;
4181     }
4182 }
4183 
4184 int hci_send_cmd_packet(uint8_t *packet, int size){
4185     // house-keeping
4186 
4187     if (IS_COMMAND(packet, hci_write_loopback_mode)){
4188         hci_stack->loopback_mode = packet[3];
4189     }
4190 
4191 #ifdef ENABLE_CLASSIC
4192     bd_addr_t addr;
4193     hci_connection_t * conn;
4194 
4195     // create_connection?
4196     if (IS_COMMAND(packet, hci_create_connection)){
4197         reverse_bd_addr(&packet[3], addr);
4198         log_info("Create_connection to %s", bd_addr_to_str(addr));
4199 
4200         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4201         if (!conn){
4202             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4203             if (!conn){
4204                 // notify client that alloc failed
4205                 hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4206                 return -1; // packet not sent to controller
4207             }
4208             conn->state = SEND_CREATE_CONNECTION;
4209         }
4210         log_info("conn state %u", conn->state);
4211         switch (conn->state){
4212             // if connection active exists
4213             case OPEN:
4214                 // and OPEN, emit connection complete command
4215                 hci_emit_connection_complete(addr, conn->con_handle, 0);
4216                 return -1; // packet not sent to controller
4217             case RECEIVED_DISCONNECTION_COMPLETE:
4218                 // create connection triggered in disconnect complete event, let's do it now
4219                 break;
4220             case SEND_CREATE_CONNECTION:
4221                 // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
4222                 break;
4223             default:
4224                 // otherwise, just ignore as it is already in the open process
4225                 return -1; // packet not sent to controller
4226         }
4227         conn->state = SENT_CREATE_CONNECTION;
4228 
4229         // track outgoing connection
4230         hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
4231         (void)memcpy(hci_stack->outgoing_addr, addr, 6);
4232     }
4233 
4234     else if (IS_COMMAND(packet, hci_link_key_request_reply)){
4235         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
4236     }
4237     else if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
4238         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
4239     }
4240 
4241     else if (IS_COMMAND(packet, hci_delete_stored_link_key)){
4242         if (hci_stack->link_key_db){
4243             reverse_bd_addr(&packet[3], addr);
4244             hci_stack->link_key_db->delete_link_key(addr);
4245         }
4246     }
4247 
4248     else if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
4249     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
4250         reverse_bd_addr(&packet[3], addr);
4251         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4252         if (conn){
4253             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
4254         }
4255     }
4256 
4257     else if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
4258     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
4259     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
4260     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
4261         reverse_bd_addr(&packet[3], addr);
4262         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4263         if (conn){
4264             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
4265         }
4266     }
4267 
4268 #ifdef ENABLE_SCO_OVER_HCI
4269     // setup_synchronous_connection? Voice setting at offset 22
4270     else if (IS_COMMAND(packet, hci_setup_synchronous_connection)){
4271         // TODO: compare to current setting if sco connection already active
4272         hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
4273     }
4274     // accept_synchronus_connection? Voice setting at offset 18
4275     else if (IS_COMMAND(packet, hci_accept_synchronous_connection)){
4276         // TODO: compare to current setting if sco connection already active
4277         hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
4278     }
4279 #endif
4280 #endif
4281 
4282 #ifdef ENABLE_BLE
4283     else if (IS_COMMAND(packet, hci_le_set_random_address)){
4284         hci_stack->le_random_address_set = 1;
4285         reverse_bd_addr(&packet[3], hci_stack->le_random_address);
4286     }
4287 #ifdef ENABLE_LE_PERIPHERAL
4288     else if (IS_COMMAND(packet, hci_le_set_advertise_enable)){
4289         hci_stack->le_advertisements_active = packet[3];
4290     }
4291 #endif
4292 #ifdef ENABLE_LE_CENTRAL
4293     else if (IS_COMMAND(packet, hci_le_create_connection)){
4294         // white list used?
4295         uint8_t initiator_filter_policy = packet[7];
4296         switch (initiator_filter_policy){
4297             case 0:
4298                 // whitelist not used
4299                 hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
4300                 break;
4301             case 1:
4302                 hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
4303                 break;
4304             default:
4305                 log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
4306                 break;
4307         }
4308     }
4309     else if (IS_COMMAND(packet, hci_le_create_connection_cancel)){
4310         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
4311     }
4312 #endif
4313 #endif
4314 
4315     hci_stack->num_cmd_packets--;
4316 
4317     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4318     return hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4319 }
4320 
4321 // disconnect because of security block
4322 void hci_disconnect_security_block(hci_con_handle_t con_handle){
4323     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4324     if (!connection) return;
4325     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
4326 }
4327 
4328 
4329 // Configure Secure Simple Pairing
4330 
4331 #ifdef ENABLE_CLASSIC
4332 
4333 // enable will enable SSP during init
4334 void gap_ssp_set_enable(int enable){
4335     hci_stack->ssp_enable = enable;
4336 }
4337 
4338 static int hci_local_ssp_activated(void){
4339     return gap_ssp_supported() && hci_stack->ssp_enable;
4340 }
4341 
4342 // if set, BTstack will respond to io capability request using authentication requirement
4343 void gap_ssp_set_io_capability(int io_capability){
4344     hci_stack->ssp_io_capability = io_capability;
4345 }
4346 void gap_ssp_set_authentication_requirement(int authentication_requirement){
4347     hci_stack->ssp_authentication_requirement = authentication_requirement;
4348 }
4349 
4350 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
4351 void gap_ssp_set_auto_accept(int auto_accept){
4352     hci_stack->ssp_auto_accept = auto_accept;
4353 }
4354 
4355 void gap_secure_connections_enable(bool enable){
4356     hci_stack->secure_connections_enable = enable;
4357 }
4358 
4359 #endif
4360 
4361 // va_list part of hci_send_cmd
4362 int hci_send_cmd_va_arg(const hci_cmd_t *cmd, va_list argptr){
4363     if (!hci_can_send_command_packet_now()){
4364         log_error("hci_send_cmd called but cannot send packet now");
4365         return 0;
4366     }
4367 
4368     // for HCI INITIALIZATION
4369     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
4370     hci_stack->last_cmd_opcode = cmd->opcode;
4371 
4372     hci_reserve_packet_buffer();
4373     uint8_t * packet = hci_stack->hci_packet_buffer;
4374     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
4375     int err = hci_send_cmd_packet(packet, size);
4376 
4377     // release packet buffer on error or for synchronous transport implementations
4378     if ((err < 0) || hci_transport_synchronous()){
4379         hci_release_packet_buffer();
4380         hci_emit_transport_packet_sent();
4381     }
4382 
4383     return err;
4384 }
4385 
4386 /**
4387  * pre: numcmds >= 0 - it's allowed to send a command to the controller
4388  */
4389 int hci_send_cmd(const hci_cmd_t *cmd, ...){
4390     va_list argptr;
4391     va_start(argptr, cmd);
4392     int res = hci_send_cmd_va_arg(cmd, argptr);
4393     va_end(argptr);
4394     return res;
4395 }
4396 
4397 // Create various non-HCI events.
4398 // TODO: generalize, use table similar to hci_create_command
4399 
4400 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
4401     // dump packet
4402     if (dump) {
4403         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
4404     }
4405 
4406     // dispatch to all event handlers
4407     btstack_linked_list_iterator_t it;
4408     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
4409     while (btstack_linked_list_iterator_has_next(&it)){
4410         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
4411         entry->callback(HCI_EVENT_PACKET, 0, event, size);
4412     }
4413 }
4414 
4415 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
4416     if (!hci_stack->acl_packet_handler) return;
4417     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
4418 }
4419 
4420 #ifdef ENABLE_CLASSIC
4421 static void hci_notify_if_sco_can_send_now(void){
4422     // notify SCO sender if waiting
4423     if (!hci_stack->sco_waiting_for_can_send_now) return;
4424     if (hci_can_send_sco_packet_now()){
4425         hci_stack->sco_waiting_for_can_send_now = 0;
4426         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
4427         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
4428         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
4429     }
4430 }
4431 
4432 // parsing end emitting has been merged to reduce code size
4433 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
4434     uint8_t event[19+GAP_INQUIRY_MAX_NAME_LEN];
4435 
4436     uint8_t * eir_data;
4437     ad_context_t context;
4438     const uint8_t * name;
4439     uint8_t         name_len;
4440 
4441     if (size < 3) return;
4442 
4443     int event_type = hci_event_packet_get_type(packet);
4444     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
4445     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
4446 
4447     switch (event_type){
4448         case HCI_EVENT_INQUIRY_RESULT:
4449         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4450             if (size != (3 + (num_responses * 14))) return;
4451             break;
4452         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4453             if (size != 257) return;
4454             if (num_responses != 1) return;
4455             break;
4456         default:
4457             return;
4458     }
4459 
4460     // event[1] is set at the end
4461     int i;
4462     for (i=0; i<num_responses;i++){
4463         memset(event, 0, sizeof(event));
4464         event[0] = GAP_EVENT_INQUIRY_RESULT;
4465         uint8_t event_size = 18;    // if name is not set by EIR
4466 
4467         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
4468         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
4469         (void)memcpy(&event[9],
4470                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
4471                      3); // class of device
4472         (void)memcpy(&event[12],
4473                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
4474                      2); // clock offset
4475 
4476         switch (event_type){
4477             case HCI_EVENT_INQUIRY_RESULT:
4478                 // 14,15,16,17 = 0, size 18
4479                 break;
4480             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4481                 event[14] = 1;
4482                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4483                 // 16,17 = 0, size 18
4484                 break;
4485             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4486                 event[14] = 1;
4487                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4488                 // EIR packets only contain a single inquiry response
4489                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
4490                 name = NULL;
4491                 // Iterate over EIR data
4492                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
4493                     uint8_t data_type    = ad_iterator_get_data_type(&context);
4494                     uint8_t data_size    = ad_iterator_get_data_len(&context);
4495                     const uint8_t * data = ad_iterator_get_data(&context);
4496                     // Prefer Complete Local Name over Shortend Local Name
4497                     switch (data_type){
4498                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
4499                             if (name) continue;
4500                             /* fall through */
4501                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
4502                             name = data;
4503                             name_len = data_size;
4504                             break;
4505                         default:
4506                             break;
4507                     }
4508                 }
4509                 if (name){
4510                     event[16] = 1;
4511                     // truncate name if needed
4512                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
4513                     event[17] = len;
4514                     (void)memcpy(&event[18], name, len);
4515                     event_size += len;
4516                 }
4517                 break;
4518         }
4519         event[1] = event_size - 2;
4520         hci_emit_event(event, event_size, 1);
4521     }
4522 }
4523 #endif
4524 
4525 void hci_emit_state(void){
4526     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
4527     uint8_t event[3];
4528     event[0] = BTSTACK_EVENT_STATE;
4529     event[1] = sizeof(event) - 2;
4530     event[2] = hci_stack->state;
4531     hci_emit_event(event, sizeof(event), 1);
4532 }
4533 
4534 #ifdef ENABLE_CLASSIC
4535 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4536     uint8_t event[13];
4537     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
4538     event[1] = sizeof(event) - 2;
4539     event[2] = status;
4540     little_endian_store_16(event, 3, con_handle);
4541     reverse_bd_addr(address, &event[5]);
4542     event[11] = 1; // ACL connection
4543     event[12] = 0; // encryption disabled
4544     hci_emit_event(event, sizeof(event), 1);
4545 }
4546 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
4547     if (disable_l2cap_timeouts) return;
4548     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
4549     uint8_t event[4];
4550     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
4551     event[1] = sizeof(event) - 2;
4552     little_endian_store_16(event, 2, conn->con_handle);
4553     hci_emit_event(event, sizeof(event), 1);
4554 }
4555 #endif
4556 
4557 #ifdef ENABLE_BLE
4558 #ifdef ENABLE_LE_CENTRAL
4559 static void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4560     uint8_t event[21];
4561     event[0] = HCI_EVENT_LE_META;
4562     event[1] = sizeof(event) - 2;
4563     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
4564     event[3] = status;
4565     little_endian_store_16(event, 4, con_handle);
4566     event[6] = 0; // TODO: role
4567     event[7] = address_type;
4568     reverse_bd_addr(address, &event[8]);
4569     little_endian_store_16(event, 14, 0); // interval
4570     little_endian_store_16(event, 16, 0); // latency
4571     little_endian_store_16(event, 18, 0); // supervision timeout
4572     event[20] = 0; // master clock accuracy
4573     hci_emit_event(event, sizeof(event), 1);
4574 }
4575 #endif
4576 #endif
4577 
4578 static void hci_emit_transport_packet_sent(void){
4579     // notify upper stack that it might be possible to send again
4580     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
4581     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
4582 }
4583 
4584 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
4585     uint8_t event[6];
4586     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
4587     event[1] = sizeof(event) - 2;
4588     event[2] = 0; // status = OK
4589     little_endian_store_16(event, 3, con_handle);
4590     event[5] = reason;
4591     hci_emit_event(event, sizeof(event), 1);
4592 }
4593 
4594 static void hci_emit_nr_connections_changed(void){
4595     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
4596     uint8_t event[3];
4597     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
4598     event[1] = sizeof(event) - 2;
4599     event[2] = nr_hci_connections();
4600     hci_emit_event(event, sizeof(event), 1);
4601 }
4602 
4603 static void hci_emit_hci_open_failed(void){
4604     log_info("BTSTACK_EVENT_POWERON_FAILED");
4605     uint8_t event[2];
4606     event[0] = BTSTACK_EVENT_POWERON_FAILED;
4607     event[1] = sizeof(event) - 2;
4608     hci_emit_event(event, sizeof(event), 1);
4609 }
4610 
4611 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
4612     log_info("hci_emit_dedicated_bonding_result %u ", status);
4613     uint8_t event[9];
4614     int pos = 0;
4615     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
4616     event[pos++] = sizeof(event) - 2;
4617     event[pos++] = status;
4618     reverse_bd_addr(address, &event[pos]);
4619     hci_emit_event(event, sizeof(event), 1);
4620 }
4621 
4622 
4623 #ifdef ENABLE_CLASSIC
4624 
4625 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
4626     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
4627     uint8_t event[5];
4628     int pos = 0;
4629     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
4630     event[pos++] = sizeof(event) - 2;
4631     little_endian_store_16(event, 2, con_handle);
4632     pos += 2;
4633     event[pos++] = level;
4634     hci_emit_event(event, sizeof(event), 1);
4635 }
4636 
4637 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
4638     if (!connection) return LEVEL_0;
4639     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
4640     if ((connection->authentication_flags & CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
4641     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
4642     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
4643     // LEVEL 4 always requires 128 bit encrytion key size
4644     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
4645         security_level = LEVEL_3;
4646     }
4647     return security_level;
4648 }
4649 
4650 static void hci_emit_discoverable_enabled(uint8_t enabled){
4651     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
4652     uint8_t event[3];
4653     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
4654     event[1] = sizeof(event) - 2;
4655     event[2] = enabled;
4656     hci_emit_event(event, sizeof(event), 1);
4657 }
4658 
4659 // query if remote side supports eSCO
4660 int hci_remote_esco_supported(hci_con_handle_t con_handle){
4661     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4662     if (!connection) return 0;
4663     return (connection->remote_supported_features[0] & 1) != 0;
4664 }
4665 
4666 static bool hci_ssp_supported(hci_connection_t * connection){
4667     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
4668     return (connection->bonding_flags & mask) == mask;
4669 }
4670 
4671 // query if remote side supports SSP
4672 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
4673     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4674     if (!connection) return 0;
4675     return hci_ssp_supported(connection) ? 1 : 0;
4676 }
4677 
4678 int gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
4679     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
4680 }
4681 
4682 // GAP API
4683 /**
4684  * @bbrief enable/disable bonding. default is enabled
4685  * @praram enabled
4686  */
4687 void gap_set_bondable_mode(int enable){
4688     hci_stack->bondable = enable ? 1 : 0;
4689 }
4690 /**
4691  * @brief Get bondable mode.
4692  * @return 1 if bondable
4693  */
4694 int gap_get_bondable_mode(void){
4695     return hci_stack->bondable;
4696 }
4697 
4698 /**
4699  * @brief map link keys to security levels
4700  */
4701 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
4702     switch (link_key_type){
4703         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4704             return LEVEL_4;
4705         case COMBINATION_KEY:
4706         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4707             return LEVEL_3;
4708         default:
4709             return LEVEL_2;
4710     }
4711 }
4712 
4713 /**
4714  * @brief map link keys to secure connection yes/no
4715  */
4716 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
4717     switch (link_key_type){
4718         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4719         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4720             return 1;
4721         default:
4722             return 0;
4723     }
4724 }
4725 
4726 /**
4727  * @brief map link keys to authenticated
4728  */
4729 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
4730     switch (link_key_type){
4731         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4732         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4733             return 1;
4734         default:
4735             return 0;
4736     }
4737 }
4738 
4739 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
4740     log_info("gap_mitm_protection_required_for_security_level %u", level);
4741     return level > LEVEL_2;
4742 }
4743 
4744 /**
4745  * @brief get current security level
4746  */
4747 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
4748     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4749     if (!connection) return LEVEL_0;
4750     return gap_security_level_for_connection(connection);
4751 }
4752 
4753 /**
4754  * @brief request connection to device to
4755  * @result GAP_AUTHENTICATION_RESULT
4756  */
4757 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
4758     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4759     if (!connection){
4760         hci_emit_security_level(con_handle, LEVEL_0);
4761         return;
4762     }
4763     gap_security_level_t current_level = gap_security_level(con_handle);
4764     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
4765         requested_level, connection->requested_security_level, current_level);
4766 
4767     // assumption: earlier requested security higher than current level => security request is active
4768     if (current_level < connection->requested_security_level){
4769         if (connection->requested_security_level < requested_level){
4770             // increase requested level as new level is higher
4771 
4772             // TODO: handle re-authentication when done
4773 
4774             connection->requested_security_level = requested_level;
4775         }
4776         return;
4777     }
4778 
4779     // no request active, notify if security sufficient
4780     if (requested_level <= current_level){
4781         hci_emit_security_level(con_handle, current_level);
4782         return;
4783     }
4784 
4785     // start pairing to increase security level
4786     connection->requested_security_level = requested_level;
4787 
4788 #if 0
4789     // sending encryption request without a link key results in an error.
4790     // TODO: figure out how to use it properly
4791 
4792     // would enabling ecnryption suffice (>= LEVEL_2)?
4793     if (hci_stack->link_key_db){
4794         link_key_type_t link_key_type;
4795         link_key_t      link_key;
4796         if (hci_stack->link_key_db->get_link_key( &connection->address, &link_key, &link_key_type)){
4797             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
4798                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
4799                 return;
4800             }
4801         }
4802     }
4803 #endif
4804 
4805     // start to authenticate connection if not already active
4806     if ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
4807     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
4808     hci_run();
4809 }
4810 
4811 /**
4812  * @brief start dedicated bonding with device. disconnect after bonding
4813  * @param device
4814  * @param request MITM protection
4815  * @result GAP_DEDICATED_BONDING_COMPLETE
4816  */
4817 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
4818 
4819     // create connection state machine
4820     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
4821 
4822     if (!connection){
4823         return BTSTACK_MEMORY_ALLOC_FAILED;
4824     }
4825 
4826     // delete linkn key
4827     gap_drop_link_key_for_bd_addr(device);
4828 
4829     // configure LEVEL_2/3, dedicated bonding
4830     connection->state = SEND_CREATE_CONNECTION;
4831     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
4832     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
4833     connection->bonding_flags = BONDING_DEDICATED;
4834 
4835     // wait for GAP Security Result and send GAP Dedicated Bonding complete
4836 
4837     // handle: connnection failure (connection complete != ok)
4838     // handle: authentication failure
4839     // handle: disconnect on done
4840 
4841     hci_run();
4842 
4843     return 0;
4844 }
4845 #endif
4846 
4847 void gap_set_local_name(const char * local_name){
4848     hci_stack->local_name = local_name;
4849 }
4850 
4851 
4852 #ifdef ENABLE_BLE
4853 
4854 #ifdef ENABLE_LE_CENTRAL
4855 void gap_start_scan(void){
4856     hci_stack->le_scanning_enabled = 1;
4857     hci_run();
4858 }
4859 
4860 void gap_stop_scan(void){
4861     hci_stack->le_scanning_enabled = 0;
4862     hci_run();
4863 }
4864 
4865 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
4866     hci_stack->le_scan_type     = scan_type;
4867     hci_stack->le_scan_interval = scan_interval;
4868     hci_stack->le_scan_window   = scan_window;
4869     hci_run();
4870 }
4871 
4872 uint8_t gap_connect(bd_addr_t addr, bd_addr_type_t addr_type){
4873     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
4874     if (!conn){
4875         log_info("gap_connect: no connection exists yet, creating context");
4876         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
4877         if (!conn){
4878             // notify client that alloc failed
4879             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4880             log_info("gap_connect: failed to alloc hci_connection_t");
4881             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
4882         }
4883         conn->state = SEND_CREATE_CONNECTION;
4884         log_info("gap_connect: send create connection next");
4885         hci_run();
4886         return ERROR_CODE_SUCCESS;
4887     }
4888 
4889     if (!hci_is_le_connection(conn) ||
4890         (conn->state == SEND_CREATE_CONNECTION) ||
4891         (conn->state == SENT_CREATE_CONNECTION)) {
4892         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
4893         log_error("gap_connect: classic connection or connect is already being created");
4894         return GATT_CLIENT_IN_WRONG_STATE;
4895     }
4896 
4897     // check if connection was just disconnected
4898     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
4899         log_info("gap_connect: send create connection (again)");
4900         conn->state = SEND_CREATE_CONNECTION;
4901         hci_run();
4902         return ERROR_CODE_SUCCESS;
4903     }
4904 
4905     log_info("gap_connect: context exists with state %u", conn->state);
4906     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
4907     hci_run();
4908     return ERROR_CODE_SUCCESS;
4909 }
4910 
4911 // @assumption: only a single outgoing LE Connection exists
4912 static hci_connection_t * gap_get_outgoing_connection(void){
4913     btstack_linked_item_t *it;
4914     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4915         hci_connection_t * conn = (hci_connection_t *) it;
4916         if (!hci_is_le_connection(conn)) continue;
4917         switch (conn->state){
4918             case SEND_CREATE_CONNECTION:
4919             case SENT_CREATE_CONNECTION:
4920             case SENT_CANCEL_CONNECTION:
4921                 return conn;
4922             default:
4923                 break;
4924         };
4925     }
4926     return NULL;
4927 }
4928 
4929 uint8_t gap_connect_cancel(void){
4930     hci_connection_t * conn = gap_get_outgoing_connection();
4931     if (!conn) return 0;
4932     switch (conn->state){
4933         case SEND_CREATE_CONNECTION:
4934             // skip sending create connection and emit event instead
4935             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
4936             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
4937             btstack_memory_hci_connection_free( conn );
4938             break;
4939         case SENT_CREATE_CONNECTION:
4940             // request to send cancel connection
4941             conn->state = SEND_CANCEL_CONNECTION;
4942             hci_run();
4943             break;
4944         default:
4945             break;
4946     }
4947     return 0;
4948 }
4949 #endif
4950 
4951 #ifdef ENABLE_LE_CENTRAL
4952 /**
4953  * @brief Set connection parameters for outgoing connections
4954  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
4955  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
4956  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
4957  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
4958  * @param conn_latency, default: 4
4959  * @param supervision_timeout (unit: 10ms), default: 720 ms
4960  * @param min_ce_length (unit: 0.625ms), default: 10 ms
4961  * @param max_ce_length (unit: 0.625ms), default: 30 ms
4962  */
4963 
4964 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
4965     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
4966     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
4967     hci_stack->le_connection_scan_interval = conn_scan_interval;
4968     hci_stack->le_connection_scan_window = conn_scan_window;
4969     hci_stack->le_connection_interval_min = conn_interval_min;
4970     hci_stack->le_connection_interval_max = conn_interval_max;
4971     hci_stack->le_connection_latency = conn_latency;
4972     hci_stack->le_supervision_timeout = supervision_timeout;
4973     hci_stack->le_minimum_ce_length = min_ce_length;
4974     hci_stack->le_maximum_ce_length = max_ce_length;
4975 }
4976 #endif
4977 
4978 /**
4979  * @brief Updates the connection parameters for a given LE connection
4980  * @param handle
4981  * @param conn_interval_min (unit: 1.25ms)
4982  * @param conn_interval_max (unit: 1.25ms)
4983  * @param conn_latency
4984  * @param supervision_timeout (unit: 10ms)
4985  * @returns 0 if ok
4986  */
4987 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
4988     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
4989     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4990     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
4991     connection->le_conn_interval_min = conn_interval_min;
4992     connection->le_conn_interval_max = conn_interval_max;
4993     connection->le_conn_latency = conn_latency;
4994     connection->le_supervision_timeout = supervision_timeout;
4995     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
4996     hci_run();
4997     return 0;
4998 }
4999 
5000 /**
5001  * @brief Request an update of the connection parameter for a given LE connection
5002  * @param handle
5003  * @param conn_interval_min (unit: 1.25ms)
5004  * @param conn_interval_max (unit: 1.25ms)
5005  * @param conn_latency
5006  * @param supervision_timeout (unit: 10ms)
5007  * @returns 0 if ok
5008  */
5009 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5010     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5011     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5012     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5013     connection->le_conn_interval_min = conn_interval_min;
5014     connection->le_conn_interval_max = conn_interval_max;
5015     connection->le_conn_latency = conn_latency;
5016     connection->le_supervision_timeout = supervision_timeout;
5017     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5018     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5019     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5020     return 0;
5021 }
5022 
5023 #ifdef ENABLE_LE_PERIPHERAL
5024 
5025 static void gap_advertisments_changed(void){
5026     // disable advertisements before updating adv, scan data, or adv params
5027     if (hci_stack->le_advertisements_active){
5028         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE | LE_ADVERTISEMENT_TASKS_ENABLE;
5029     }
5030     hci_run();
5031 }
5032 
5033 /**
5034  * @brief Set Advertisement Data
5035  * @param advertising_data_length
5036  * @param advertising_data (max 31 octets)
5037  * @note data is not copied, pointer has to stay valid
5038  */
5039 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
5040     hci_stack->le_advertisements_data_len = advertising_data_length;
5041     hci_stack->le_advertisements_data = advertising_data;
5042     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
5043     gap_advertisments_changed();
5044 }
5045 
5046 /**
5047  * @brief Set Scan Response Data
5048  * @param advertising_data_length
5049  * @param advertising_data (max 31 octets)
5050  * @note data is not copied, pointer has to stay valid
5051  */
5052 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
5053     hci_stack->le_scan_response_data_len = scan_response_data_length;
5054     hci_stack->le_scan_response_data = scan_response_data;
5055     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
5056     gap_advertisments_changed();
5057 }
5058 
5059 /**
5060  * @brief Set Advertisement Parameters
5061  * @param adv_int_min
5062  * @param adv_int_max
5063  * @param adv_type
5064  * @param direct_address_type
5065  * @param direct_address
5066  * @param channel_map
5067  * @param filter_policy
5068  *
5069  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
5070  */
5071  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
5072     uint8_t direct_address_typ, bd_addr_t direct_address,
5073     uint8_t channel_map, uint8_t filter_policy) {
5074 
5075     hci_stack->le_advertisements_interval_min = adv_int_min;
5076     hci_stack->le_advertisements_interval_max = adv_int_max;
5077     hci_stack->le_advertisements_type = adv_type;
5078     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
5079     hci_stack->le_advertisements_channel_map = channel_map;
5080     hci_stack->le_advertisements_filter_policy = filter_policy;
5081     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
5082                  6);
5083 
5084     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5085     gap_advertisments_changed();
5086  }
5087 
5088 /**
5089  * @brief Enable/Disable Advertisements
5090  * @param enabled
5091  */
5092 void gap_advertisements_enable(int enabled){
5093     hci_stack->le_advertisements_enabled = enabled;
5094     if (enabled && !hci_stack->le_advertisements_active){
5095         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
5096     }
5097     if (!enabled && hci_stack->le_advertisements_active){
5098         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE;
5099     }
5100     hci_run();
5101 }
5102 
5103 #endif
5104 
5105 void hci_le_set_own_address_type(uint8_t own_address_type){
5106     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
5107     if (own_address_type == hci_stack->le_own_addr_type) return;
5108     hci_stack->le_own_addr_type = own_address_type;
5109 
5110 #ifdef ENABLE_LE_PERIPHERAL
5111     // update advertisement parameters, too
5112     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5113     gap_advertisments_changed();
5114 #endif
5115 #ifdef ENABLE_LE_CENTRAL
5116     // note: we don't update scan parameters or modify ongoing connection attempts
5117 #endif
5118 }
5119 
5120 #endif
5121 
5122 uint8_t gap_disconnect(hci_con_handle_t handle){
5123     hci_connection_t * conn = hci_connection_for_handle(handle);
5124     if (!conn){
5125         hci_emit_disconnection_complete(handle, 0);
5126         return 0;
5127     }
5128     // ignore if already disconnected
5129     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5130         return 0;
5131     }
5132     conn->state = SEND_DISCONNECT;
5133     hci_run();
5134     return 0;
5135 }
5136 
5137 int gap_read_rssi(hci_con_handle_t con_handle){
5138     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5139     if (hci_connection == NULL) return 0;
5140     connectionSetAuthenticationFlags(hci_connection, READ_RSSI);
5141     hci_run();
5142     return 1;
5143 }
5144 
5145 /**
5146  * @brief Get connection type
5147  * @param con_handle
5148  * @result connection_type
5149  */
5150 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
5151     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5152     if (!conn) return GAP_CONNECTION_INVALID;
5153     switch (conn->address_type){
5154         case BD_ADDR_TYPE_LE_PUBLIC:
5155         case BD_ADDR_TYPE_LE_RANDOM:
5156             return GAP_CONNECTION_LE;
5157         case BD_ADDR_TYPE_SCO:
5158             return GAP_CONNECTION_SCO;
5159         case BD_ADDR_TYPE_ACL:
5160             return GAP_CONNECTION_ACL;
5161         default:
5162             return GAP_CONNECTION_INVALID;
5163     }
5164 }
5165 
5166 #ifdef ENABLE_BLE
5167 
5168 uint8_t gap_le_set_phy(hci_con_handle_t connection_handle, uint8_t all_phys, uint8_t tx_phys, uint8_t rx_phys, uint8_t phy_options){
5169     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5170     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5171 
5172     conn->le_phy_update_all_phys    = all_phys;
5173     conn->le_phy_update_tx_phys     = tx_phys;
5174     conn->le_phy_update_rx_phys     = rx_phys;
5175     conn->le_phy_update_phy_options = phy_options;
5176 
5177     hci_run();
5178 
5179     return 0;
5180 }
5181 
5182 #ifdef ENABLE_LE_CENTRAL
5183 /**
5184  * @brief Auto Connection Establishment - Start Connecting to device
5185  * @param address_typ
5186  * @param address
5187  * @returns 0 if ok
5188  */
5189 int gap_auto_connection_start(bd_addr_type_t address_type, bd_addr_t address){
5190     // check capacity
5191     int num_entries = btstack_linked_list_count(&hci_stack->le_whitelist);
5192     if (num_entries >= hci_stack->le_whitelist_capacity) return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
5193     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
5194     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
5195     entry->address_type = address_type;
5196     (void)memcpy(entry->address, address, 6);
5197     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
5198     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
5199     hci_run();
5200     return 0;
5201 }
5202 
5203 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address){
5204     btstack_linked_list_iterator_t it;
5205     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5206     while (btstack_linked_list_iterator_has_next(&it)){
5207         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5208         if (entry->address_type != address_type) continue;
5209         if (memcmp(entry->address, address, 6) != 0) continue;
5210         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5211             // remove from controller if already present
5212             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5213             continue;
5214         }
5215         // direclty remove entry from whitelist
5216         btstack_linked_list_iterator_remove(&it);
5217         btstack_memory_whitelist_entry_free(entry);
5218     }
5219 }
5220 
5221 /**
5222  * @brief Auto Connection Establishment - Stop Connecting to device
5223  * @param address_typ
5224  * @param address
5225  * @returns 0 if ok
5226  */
5227 int gap_auto_connection_stop(bd_addr_type_t address_type, bd_addr_t address){
5228     hci_remove_from_whitelist(address_type, address);
5229     hci_run();
5230     return 0;
5231 }
5232 
5233 /**
5234  * @brief Auto Connection Establishment - Stop everything
5235  * @note  Convenience function to stop all active auto connection attempts
5236  */
5237 void gap_auto_connection_stop_all(void){
5238     btstack_linked_list_iterator_t it;
5239     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5240     while (btstack_linked_list_iterator_has_next(&it)){
5241         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5242         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5243             // remove from controller if already present
5244             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5245             continue;
5246         }
5247         // directly remove entry from whitelist
5248         btstack_linked_list_iterator_remove(&it);
5249         btstack_memory_whitelist_entry_free(entry);
5250     }
5251     hci_run();
5252 }
5253 
5254 uint16_t gap_le_connection_interval(hci_con_handle_t connection_handle){
5255     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5256     if (!conn) return 0;
5257     return conn->le_connection_interval;
5258 }
5259 #endif
5260 #endif
5261 
5262 #ifdef ENABLE_CLASSIC
5263 /**
5264  * @brief Set Extended Inquiry Response data
5265  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
5266  * @note has to be done before stack starts up
5267  */
5268 void gap_set_extended_inquiry_response(const uint8_t * data){
5269     hci_stack->eir_data = data;
5270 }
5271 
5272 /**
5273  * @brief Start GAP Classic Inquiry
5274  * @param duration in 1.28s units
5275  * @return 0 if ok
5276  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
5277  */
5278 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
5279     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
5280     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5281     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
5282         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
5283     }
5284     hci_stack->inquiry_state = duration_in_1280ms_units;
5285     hci_run();
5286     return 0;
5287 }
5288 
5289 /**
5290  * @brief Stop GAP Classic Inquiry
5291  * @returns 0 if ok
5292  */
5293 int gap_inquiry_stop(void){
5294     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
5295         // emit inquiry complete event, before it even started
5296         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
5297         hci_emit_event(event, sizeof(event), 1);
5298         return 0;
5299     }
5300     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
5301     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
5302     hci_run();
5303     return 0;
5304 }
5305 
5306 
5307 /**
5308  * @brief Remote Name Request
5309  * @param addr
5310  * @param page_scan_repetition_mode
5311  * @param clock_offset only used when bit 15 is set
5312  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
5313  */
5314 int gap_remote_name_request(bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
5315     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5316     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
5317     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
5318     hci_stack->remote_name_clock_offset = clock_offset;
5319     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
5320     hci_run();
5321     return 0;
5322 }
5323 
5324 static int gap_pairing_set_state_and_run(bd_addr_t addr, uint8_t state){
5325     hci_stack->gap_pairing_state = state;
5326     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
5327     hci_run();
5328     return 0;
5329 }
5330 
5331 /**
5332  * @brief Legacy Pairing Pin Code Response
5333  * @param addr
5334  * @param pin
5335  * @return 0 if ok
5336  */
5337 int gap_pin_code_response(bd_addr_t addr, const char * pin){
5338     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5339     hci_stack->gap_pairing_input.gap_pairing_pin = pin;
5340     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
5341 }
5342 
5343 /**
5344  * @brief Abort Legacy Pairing
5345  * @param addr
5346  * @param pin
5347  * @return 0 if ok
5348  */
5349 int gap_pin_code_negative(bd_addr_t addr){
5350     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5351     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
5352 }
5353 
5354 /**
5355  * @brief SSP Passkey Response
5356  * @param addr
5357  * @param passkey
5358  * @return 0 if ok
5359  */
5360 int gap_ssp_passkey_response(bd_addr_t addr, uint32_t passkey){
5361     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5362     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
5363     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
5364 }
5365 
5366 /**
5367  * @brief Abort SSP Passkey Entry/Pairing
5368  * @param addr
5369  * @param pin
5370  * @return 0 if ok
5371  */
5372 int gap_ssp_passkey_negative(bd_addr_t addr){
5373     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5374     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
5375 }
5376 
5377 /**
5378  * @brief Accept SSP Numeric Comparison
5379  * @param addr
5380  * @param passkey
5381  * @return 0 if ok
5382  */
5383 int gap_ssp_confirmation_response(bd_addr_t addr){
5384     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5385     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
5386 }
5387 
5388 /**
5389  * @brief Abort SSP Numeric Comparison/Pairing
5390  * @param addr
5391  * @param pin
5392  * @return 0 if ok
5393  */
5394 int gap_ssp_confirmation_negative(bd_addr_t addr){
5395     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5396     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
5397 }
5398 
5399 /**
5400  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
5401  * @param inquiry_mode see bluetooth_defines.h
5402  */
5403 void hci_set_inquiry_mode(inquiry_mode_t mode){
5404     hci_stack->inquiry_mode = mode;
5405 }
5406 
5407 /**
5408  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
5409  */
5410 void hci_set_sco_voice_setting(uint16_t voice_setting){
5411     hci_stack->sco_voice_setting = voice_setting;
5412 }
5413 
5414 /**
5415  * @brief Get SCO Voice Setting
5416  * @return current voice setting
5417  */
5418 uint16_t hci_get_sco_voice_setting(void){
5419     return hci_stack->sco_voice_setting;
5420 }
5421 
5422 static int hci_have_usb_transport(void){
5423     if (!hci_stack->hci_transport) return 0;
5424     const char * transport_name = hci_stack->hci_transport->name;
5425     if (!transport_name) return 0;
5426     return (transport_name[0] == 'H') && (transport_name[1] == '2');
5427 }
5428 
5429 /** @brief Get SCO packet length for current SCO Voice setting
5430  *  @note  Using SCO packets of the exact length is required for USB transfer
5431  *  @return Length of SCO packets in bytes (not audio frames)
5432  */
5433 int hci_get_sco_packet_length(void){
5434     int sco_packet_length = 0;
5435 
5436 #ifdef ENABLE_SCO_OVER_HCI
5437 
5438     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
5439     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
5440 
5441     if (hci_have_usb_transport()){
5442         // see Core Spec for H2 USB Transfer.
5443         // 3 byte SCO header + 24 bytes per connection
5444         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
5445         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
5446     } else {
5447         // 3 byte SCO header + SCO packet size over the air (60 bytes)
5448         sco_packet_length = 3 + 60 * multiplier;
5449         // assert that it still fits inside an SCO buffer
5450         if (sco_packet_length > hci_stack->sco_data_packet_length){
5451             sco_packet_length = 3 + 60;
5452         }
5453     }
5454 #endif
5455     return sco_packet_length;
5456 }
5457 
5458 /**
5459 * @brief Sets the master/slave policy
5460 * @param policy (0: attempt to become master, 1: let connecting device decide)
5461 */
5462 void hci_set_master_slave_policy(uint8_t policy){
5463     hci_stack->master_slave_policy = policy;
5464 }
5465 
5466 #endif
5467 
5468 HCI_STATE hci_get_state(void){
5469     return hci_stack->state;
5470 }
5471 
5472 #ifdef ENABLE_CLASSIC
5473 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr)){
5474     hci_stack->gap_classic_accept_callback = accept_callback;
5475 }
5476 #endif
5477 
5478 /**
5479  * @brief Set callback for Bluetooth Hardware Error
5480  */
5481 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
5482     hci_stack->hardware_error_callback = fn;
5483 }
5484 
5485 void hci_disconnect_all(void){
5486     btstack_linked_list_iterator_t it;
5487     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5488     while (btstack_linked_list_iterator_has_next(&it)){
5489         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5490         if (con->state == SENT_DISCONNECT) continue;
5491         con->state = SEND_DISCONNECT;
5492     }
5493     hci_run();
5494 }
5495 
5496 uint16_t hci_get_manufacturer(void){
5497     return hci_stack->manufacturer;
5498 }
5499 
5500 #ifdef ENABLE_BLE
5501 
5502 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
5503     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
5504     if (!hci_con) return NULL;
5505     return &hci_con->sm_connection;
5506 }
5507 
5508 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
5509 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
5510 
5511 int gap_encryption_key_size(hci_con_handle_t con_handle){
5512     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5513     if (hci_connection == NULL) return 0;
5514     if (hci_is_le_connection(hci_connection)){
5515         sm_connection_t * sm_conn = &hci_connection->sm_connection;
5516         if (sm_conn->sm_connection_encrypted) {
5517             return sm_conn->sm_actual_encryption_key_size;
5518         }
5519     }
5520 #ifdef ENABLE_CLASSIC
5521     else {
5522         if ((hci_connection->authentication_flags & CONNECTION_ENCRYPTED)){
5523             return hci_connection->encryption_key_size;
5524         }
5525     }
5526 #endif
5527     return 0;
5528 }
5529 
5530 int gap_authenticated(hci_con_handle_t con_handle){
5531     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5532     if (hci_connection == NULL) return 0;
5533 
5534     switch (hci_connection->address_type){
5535         case BD_ADDR_TYPE_LE_PUBLIC:
5536         case BD_ADDR_TYPE_LE_RANDOM:
5537             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5538             return hci_connection->sm_connection.sm_connection_authenticated;
5539 #ifdef ENABLE_CLASSIC
5540         case BD_ADDR_TYPE_SCO:
5541         case BD_ADDR_TYPE_ACL:
5542             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
5543 #endif
5544         default:
5545             return 0;
5546     }
5547 }
5548 
5549 int gap_secure_connection(hci_con_handle_t con_handle){
5550     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5551     if (hci_connection == NULL) return 0;
5552 
5553     switch (hci_connection->address_type){
5554         case BD_ADDR_TYPE_LE_PUBLIC:
5555         case BD_ADDR_TYPE_LE_RANDOM:
5556             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5557             return hci_connection->sm_connection.sm_connection_sc;
5558 #ifdef ENABLE_CLASSIC
5559         case BD_ADDR_TYPE_SCO:
5560         case BD_ADDR_TYPE_ACL:
5561             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
5562 #endif
5563         default:
5564             return 0;
5565     }
5566 }
5567 
5568 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
5569     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
5570     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
5571     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
5572     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
5573     return sm_conn->sm_connection_authorization_state;
5574 }
5575 #endif
5576 
5577 #ifdef ENABLE_CLASSIC
5578 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){
5579     hci_connection_t * conn = hci_connection_for_handle(con_handle);
5580     if (!conn) return GAP_CONNECTION_INVALID;
5581     conn->sniff_min_interval = sniff_min_interval;
5582     conn->sniff_max_interval = sniff_max_interval;
5583     conn->sniff_attempt = sniff_attempt;
5584     conn->sniff_timeout = sniff_timeout;
5585     hci_run();
5586     return 0;
5587 }
5588 
5589 /**
5590  * @brief Exit Sniff mode
5591  * @param con_handle
5592  @ @return 0 if ok
5593  */
5594 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
5595     hci_connection_t * conn = hci_connection_for_handle(con_handle);
5596     if (!conn) return GAP_CONNECTION_INVALID;
5597     conn->sniff_min_interval = 0xffff;
5598     hci_run();
5599     return 0;
5600 }
5601 #endif
5602 
5603 void hci_halting_defer(void){
5604     if (hci_stack->state != HCI_STATE_HALTING) return;
5605     switch (hci_stack->substate){
5606         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
5607         case HCI_HALTING_CLOSE:
5608             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
5609             break;
5610         default:
5611             break;
5612     }
5613 }
5614 
5615 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
5616 void hci_setup_test_connections_fuzz(void){
5617     hci_connection_t * conn;
5618 
5619     // default address: 66:55:44:33:00:01
5620     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
5621 
5622     // setup Controller info
5623     hci_stack->num_cmd_packets = 255;
5624     hci_stack->acl_packets_total_num = 255;
5625 
5626     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
5627     addr[5] = 0x01;
5628     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5629     conn->con_handle = addr[5];
5630     conn->role  = HCI_ROLE_SLAVE;
5631     conn->state = RECEIVED_CONNECTION_REQUEST;
5632     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5633 
5634     // setup incoming Classic SCO connection with con handle 0x0002
5635     addr[5] = 0x02;
5636     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
5637     conn->con_handle = addr[5];
5638     conn->role  = HCI_ROLE_SLAVE;
5639     conn->state = RECEIVED_CONNECTION_REQUEST;
5640     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5641 
5642     // setup ready Classic ACL connection with con handle 0x0003
5643     addr[5] = 0x03;
5644     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5645     conn->con_handle = addr[5];
5646     conn->role  = HCI_ROLE_SLAVE;
5647     conn->state = OPEN;
5648     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5649 
5650     // setup ready Classic SCO connection with con handle 0x0004
5651     addr[5] = 0x04;
5652     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
5653     conn->con_handle = addr[5];
5654     conn->role  = HCI_ROLE_SLAVE;
5655     conn->state = OPEN;
5656     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5657 
5658     // setup ready LE ACL connection with con handle 0x005 and public address
5659     addr[5] = 0x05;
5660     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
5661     conn->con_handle = addr[5];
5662     conn->role  = HCI_ROLE_SLAVE;
5663     conn->state = OPEN;
5664     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5665 }
5666 
5667 void hci_free_connections_fuzz(void){
5668     btstack_linked_list_iterator_t it;
5669     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5670     while (btstack_linked_list_iterator_has_next(&it)){
5671         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5672         btstack_linked_list_iterator_remove(&it);
5673         btstack_memory_hci_connection_free(con);
5674     }
5675 }
5676 void hci_simulate_working_fuzz(void){
5677     hci_init_done();
5678     hci_stack->num_cmd_packets = 255;
5679 }
5680 #endif
5681