xref: /btstack/src/hci.c (revision 9cbd2215b07cfcc4a5e2f3b73b27ec83500d44bb)
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 <inttypes.h>
67 
68 #include "btstack_debug.h"
69 #include "btstack_event.h"
70 #include "btstack_linked_list.h"
71 #include "btstack_memory.h"
72 #include "bluetooth_company_id.h"
73 #include "bluetooth_data_types.h"
74 #include "gap.h"
75 #include "hci.h"
76 #include "hci_cmd.h"
77 #include "hci_dump.h"
78 #include "ad_parser.h"
79 
80 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
81 #ifndef HCI_HOST_ACL_PACKET_NUM
82 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
83 #endif
84 #ifndef HCI_HOST_ACL_PACKET_LEN
85 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
86 #endif
87 #ifndef HCI_HOST_SCO_PACKET_NUM
88 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
89 #endif
90 #ifndef HCI_HOST_SCO_PACKET_LEN
91 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
92 #endif
93 #endif
94 
95 #define HCI_CONNECTION_TIMEOUT_MS 10000
96 
97 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
98 #define HCI_RESET_RESEND_TIMEOUT_MS 200
99 #endif
100 
101 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
102 #ifndef GAP_INQUIRY_MAX_NAME_LEN
103 #define GAP_INQUIRY_MAX_NAME_LEN 32
104 #endif
105 
106 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
107 #define GAP_INQUIRY_DURATION_MIN 0x01
108 #define GAP_INQUIRY_DURATION_MAX 0x30
109 #define GAP_INQUIRY_STATE_ACTIVE 0x80
110 #define GAP_INQUIRY_STATE_IDLE 0
111 #define GAP_INQUIRY_STATE_W2_CANCEL 0x81
112 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x82
113 
114 // GAP Remote Name Request
115 #define GAP_REMOTE_NAME_STATE_IDLE 0
116 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
117 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
118 
119 // GAP Pairing
120 #define GAP_PAIRING_STATE_IDLE                       0
121 #define GAP_PAIRING_STATE_SEND_PIN                   1
122 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
123 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
124 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
125 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
126 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
127 
128 
129 // prototypes
130 #ifdef ENABLE_CLASSIC
131 static void hci_update_scan_enable(void);
132 static void hci_emit_discoverable_enabled(uint8_t enabled);
133 static int  hci_local_ssp_activated(void);
134 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
135 static bool hci_ssp_supported(hci_connection_t * connection);
136 static void hci_notify_if_sco_can_send_now(void);
137 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
138 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
139 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
140 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
141 static void hci_connection_timestamp(hci_connection_t *connection);
142 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
143 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
144 #endif
145 
146 static int  hci_power_control_on(void);
147 static void hci_power_control_off(void);
148 static void hci_state_reset(void);
149 static void hci_emit_transport_packet_sent(void);
150 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
151 static void hci_emit_nr_connections_changed(void);
152 static void hci_emit_hci_open_failed(void);
153 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
154 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
155 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
156 static void hci_run(void);
157 static int  hci_is_le_connection(hci_connection_t * connection);
158 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
159 
160 #ifdef ENABLE_CLASSIC
161 static int hci_have_usb_transport(void);
162 #endif
163 
164 #ifdef ENABLE_BLE
165 #ifdef ENABLE_LE_CENTRAL
166 // called from test/ble_client/advertising_data_parser.c
167 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
168 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address);
169 static hci_connection_t * gap_get_outgoing_connection(void);
170 #endif
171 #endif
172 
173 // the STACK is here
174 #ifndef HAVE_MALLOC
175 static hci_stack_t   hci_stack_static;
176 #endif
177 static hci_stack_t * hci_stack = NULL;
178 
179 #ifdef ENABLE_CLASSIC
180 // default name
181 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
182 
183 // test helper
184 static uint8_t disable_l2cap_timeouts = 0;
185 #endif
186 
187 /**
188  * create connection for given address
189  *
190  * @return connection OR NULL, if no memory left
191  */
192 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
193     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
194     hci_connection_t * conn = btstack_memory_hci_connection_get();
195     if (!conn) return NULL;
196     bd_addr_copy(conn->address, addr);
197     conn->address_type = addr_type;
198     conn->con_handle = 0xffff;
199     conn->authentication_flags = AUTH_FLAGS_NONE;
200     conn->bonding_flags = 0;
201     conn->requested_security_level = LEVEL_0;
202 #ifdef ENABLE_CLASSIC
203     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
204     btstack_run_loop_set_timer_context(&conn->timeout, conn);
205     hci_connection_timestamp(conn);
206 #endif
207     conn->acl_recombination_length = 0;
208     conn->acl_recombination_pos = 0;
209     conn->num_packets_sent = 0;
210 
211     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
212 #ifdef ENABLE_BLE
213     conn->le_phy_update_all_phys = 0xff;
214 #endif
215 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
216     conn->le_max_tx_octets = 27;
217 #endif
218     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
219     return conn;
220 }
221 
222 
223 /**
224  * get le connection parameter range
225 *
226  * @return le connection parameter range struct
227  */
228 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
229     *range = hci_stack->le_connection_parameter_range;
230 }
231 
232 /**
233  * set le connection parameter range
234  *
235  */
236 
237 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
238     hci_stack->le_connection_parameter_range = *range;
239 }
240 
241 /**
242  * @brief Test if connection parameters are inside in existing rage
243  * @param conn_interval_min (unit: 1.25ms)
244  * @param conn_interval_max (unit: 1.25ms)
245  * @param conn_latency
246  * @param supervision_timeout (unit: 10ms)
247  * @returns 1 if included
248  */
249 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){
250     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
251     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
252 
253     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
254     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
255 
256     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
257     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
258 
259     return 1;
260 }
261 
262 /**
263  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
264  * @note: default: 1
265  * @param max_peripheral_connections
266  */
267 #ifdef ENABLE_LE_PERIPHERAL
268 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
269     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
270 }
271 #endif
272 
273 /**
274  * get hci connections iterator
275  *
276  * @return hci connections iterator
277  */
278 
279 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
280     btstack_linked_list_iterator_init(it, &hci_stack->connections);
281 }
282 
283 /**
284  * get connection for a given handle
285  *
286  * @return connection OR NULL, if not found
287  */
288 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
289     btstack_linked_list_iterator_t it;
290     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
291     while (btstack_linked_list_iterator_has_next(&it)){
292         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
293         if ( item->con_handle == con_handle ) {
294             return item;
295         }
296     }
297     return NULL;
298 }
299 
300 /**
301  * get connection for given address
302  *
303  * @return connection OR NULL, if not found
304  */
305 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t  addr, bd_addr_type_t addr_type){
306     btstack_linked_list_iterator_t it;
307     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
308     while (btstack_linked_list_iterator_has_next(&it)){
309         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
310         if (connection->address_type != addr_type)  continue;
311         if (memcmp(addr, connection->address, 6) != 0) continue;
312         return connection;
313     }
314     return NULL;
315 }
316 
317 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
318     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
319 }
320 
321 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
322     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
323 }
324 
325 #ifdef ENABLE_CLASSIC
326 
327 #ifdef ENABLE_SCO_OVER_HCI
328 static int hci_number_sco_connections(void){
329     int connections = 0;
330     btstack_linked_list_iterator_t it;
331     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
332     while (btstack_linked_list_iterator_has_next(&it)){
333         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
334         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
335         connections++;
336     }
337     return connections;
338 }
339 #endif
340 
341 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
342     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
343 #ifdef HAVE_EMBEDDED_TICK
344     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
345         // connections might be timed out
346         hci_emit_l2cap_check_timeout(connection);
347     }
348 #else
349     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
350         // connections might be timed out
351         hci_emit_l2cap_check_timeout(connection);
352     }
353 #endif
354 }
355 
356 static void hci_connection_timestamp(hci_connection_t *connection){
357 #ifdef HAVE_EMBEDDED_TICK
358     connection->timestamp = btstack_run_loop_embedded_get_ticks();
359 #else
360     connection->timestamp = btstack_run_loop_get_time_ms();
361 #endif
362 }
363 
364 /**
365  * add authentication flags and reset timer
366  * @note: assumes classic connection
367  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
368  */
369 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
370     bd_addr_t addr;
371     reverse_bd_addr(bd_addr, addr);
372     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
373     if (conn) {
374         connectionSetAuthenticationFlags(conn, flags);
375         hci_connection_timestamp(conn);
376     }
377 }
378 
379 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
380     hci_connection_t * conn = hci_connection_for_handle(handle);
381     if (!conn) return 0;
382     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
383     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
384     return 0;
385 }
386 
387 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
388     if (!hci_stack->link_key_db) return;
389     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
390     hci_stack->link_key_db->delete_link_key(addr);
391 }
392 
393 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
394     if (!hci_stack->link_key_db) return;
395     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
396     hci_stack->link_key_db->put_link_key(addr, link_key, type);
397 }
398 
399 void gap_delete_all_link_keys(void){
400     bd_addr_t  addr;
401     link_key_t link_key;
402     link_key_type_t type;
403     btstack_link_key_iterator_t it;
404     int ok = gap_link_key_iterator_init(&it);
405     if (!ok) {
406         log_error("could not initialize iterator");
407         return;
408     }
409     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
410         gap_drop_link_key_for_bd_addr(addr);
411     }
412     gap_link_key_iterator_done(&it);
413 }
414 
415 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
416     if (!hci_stack->link_key_db) return 0;
417     if (!hci_stack->link_key_db->iterator_init) return 0;
418     return hci_stack->link_key_db->iterator_init(it);
419 }
420 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){
421     if (!hci_stack->link_key_db) return 0;
422     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
423 }
424 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
425     if (!hci_stack->link_key_db) return;
426     hci_stack->link_key_db->iterator_done(it);
427 }
428 #endif
429 
430 static int hci_is_le_connection(hci_connection_t * connection){
431     switch (connection->address_type){
432         case BD_ADDR_TYPE_LE_PUBLIC:
433         case BD_ADDR_TYPE_LE_RANDOM:
434         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
435         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
436             return 1;
437         default:
438             return 0;
439     }
440 }
441 
442 /**
443  * count connections
444  */
445 static int nr_hci_connections(void){
446     int count = 0;
447     btstack_linked_item_t *it;
448     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
449         count++;
450     }
451     return count;
452 }
453 
454 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
455 
456     unsigned int num_packets_sent_classic = 0;
457     unsigned int num_packets_sent_le = 0;
458 
459     btstack_linked_item_t *it;
460     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
461         hci_connection_t * connection = (hci_connection_t *) it;
462         if (hci_is_le_connection(connection)){
463             num_packets_sent_le += connection->num_packets_sent;
464         }
465         if (connection->address_type == BD_ADDR_TYPE_ACL){
466             num_packets_sent_classic += connection->num_packets_sent;
467         }
468     }
469     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
470     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
471     int free_slots_le = 0;
472 
473     if (free_slots_classic < 0){
474         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);
475         return 0;
476     }
477 
478     if (hci_stack->le_acl_packets_total_num){
479         // if we have LE slots, they are used
480         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
481         if (free_slots_le < 0){
482             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);
483             return 0;
484         }
485     } else {
486         // otherwise, classic slots are used for LE, too
487         free_slots_classic -= num_packets_sent_le;
488         if (free_slots_classic < 0){
489             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);
490             return 0;
491         }
492     }
493 
494     switch (address_type){
495         case BD_ADDR_TYPE_UNKNOWN:
496             log_error("hci_number_free_acl_slots: unknown address type");
497             return 0;
498 
499         case BD_ADDR_TYPE_ACL:
500             return free_slots_classic;
501 
502         default:
503            if (hci_stack->le_acl_packets_total_num){
504                return free_slots_le;
505            }
506            return free_slots_classic;
507     }
508 }
509 
510 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
511     // get connection type
512     hci_connection_t * connection = hci_connection_for_handle(con_handle);
513     if (!connection){
514         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
515         return 0;
516     }
517     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
518 }
519 
520 #ifdef ENABLE_CLASSIC
521 static int hci_number_free_sco_slots(void){
522     unsigned int num_sco_packets_sent  = 0;
523     btstack_linked_item_t *it;
524     if (hci_stack->synchronous_flow_control_enabled){
525         // explicit flow control
526         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
527             hci_connection_t * connection = (hci_connection_t *) it;
528             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
529             num_sco_packets_sent += connection->num_packets_sent;
530         }
531         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
532             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
533             return 0;
534         }
535         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
536     } else {
537         // implicit flow control -- TODO
538         int num_ready = 0;
539         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
540             hci_connection_t * connection = (hci_connection_t *) it;
541             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
542             if (connection->sco_tx_ready == 0) continue;
543             num_ready++;
544         }
545         return num_ready;
546     }
547 }
548 #endif
549 
550 // only used to send HCI Host Number Completed Packets
551 static int hci_can_send_comand_packet_transport(void){
552     if (hci_stack->hci_packet_buffer_reserved) return 0;
553 
554     // check for async hci transport implementations
555     if (hci_stack->hci_transport->can_send_packet_now){
556         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
557             return 0;
558         }
559     }
560     return 1;
561 }
562 
563 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
564 int hci_can_send_command_packet_now(void){
565     if (hci_can_send_comand_packet_transport() == 0) return 0;
566     return hci_stack->num_cmd_packets > 0;
567 }
568 
569 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
570     // check for async hci transport implementations
571     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
572     return hci_stack->hci_transport->can_send_packet_now(packet_type);
573 }
574 
575 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
576     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
577     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
578 }
579 
580 int hci_can_send_acl_le_packet_now(void){
581     if (hci_stack->hci_packet_buffer_reserved) return 0;
582     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
583 }
584 
585 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
586     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
587     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
588 }
589 
590 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
591     if (hci_stack->hci_packet_buffer_reserved) return 0;
592     return hci_can_send_prepared_acl_packet_now(con_handle);
593 }
594 
595 #ifdef ENABLE_CLASSIC
596 int hci_can_send_acl_classic_packet_now(void){
597     if (hci_stack->hci_packet_buffer_reserved) return 0;
598     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
599 }
600 
601 int hci_can_send_prepared_sco_packet_now(void){
602     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return 0;
603     if (hci_have_usb_transport()){
604         return hci_stack->sco_can_send_now;
605     } else {
606         return hci_number_free_sco_slots() > 0;
607     }
608 }
609 
610 int hci_can_send_sco_packet_now(void){
611     if (hci_stack->hci_packet_buffer_reserved) return 0;
612     return hci_can_send_prepared_sco_packet_now();
613 }
614 
615 void hci_request_sco_can_send_now_event(void){
616     hci_stack->sco_waiting_for_can_send_now = 1;
617     hci_notify_if_sco_can_send_now();
618 }
619 #endif
620 
621 // used for internal checks in l2cap.c
622 int hci_is_packet_buffer_reserved(void){
623     return hci_stack->hci_packet_buffer_reserved;
624 }
625 
626 // reserves outgoing packet buffer. @returns 1 if successful
627 int hci_reserve_packet_buffer(void){
628     if (hci_stack->hci_packet_buffer_reserved) {
629         log_error("hci_reserve_packet_buffer called but buffer already reserved");
630         return 0;
631     }
632     hci_stack->hci_packet_buffer_reserved = 1;
633     return 1;
634 }
635 
636 void hci_release_packet_buffer(void){
637     hci_stack->hci_packet_buffer_reserved = 0;
638 }
639 
640 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
641 static int hci_transport_synchronous(void){
642     return hci_stack->hci_transport->can_send_packet_now == NULL;
643 }
644 
645 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
646 
647     // 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);
648 
649     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
650     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
651     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0)){
652         max_acl_data_packet_length = hci_stack->le_data_packets_length;
653     }
654 
655 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
656     if (hci_is_le_connection(connection)){
657         max_acl_data_packet_length = connection->le_max_tx_octets;
658     }
659 #endif
660 
661     log_debug("hci_send_acl_packet_fragments entered");
662 
663     int err;
664     // multiple packets could be send on a synchronous HCI transport
665     while (true){
666 
667         log_debug("hci_send_acl_packet_fragments loop entered");
668 
669         // get current data
670         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
671         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
672         int more_fragments = 0;
673 
674         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
675         if (current_acl_data_packet_length > max_acl_data_packet_length){
676             more_fragments = 1;
677             current_acl_data_packet_length = max_acl_data_packet_length;
678         }
679 
680         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
681         if (acl_header_pos > 0){
682             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
683             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
684             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
685         }
686 
687         // update header len
688         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
689 
690         // count packet
691         connection->num_packets_sent++;
692         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", more_fragments);
693 
694         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
695         if (more_fragments){
696             // update start of next fragment to send
697             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
698         } else {
699             // done
700             hci_stack->acl_fragmentation_pos = 0;
701             hci_stack->acl_fragmentation_total_size = 0;
702         }
703 
704         // send packet
705         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
706         const int size = current_acl_data_packet_length + 4;
707         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
708         hci_stack->acl_fragmentation_tx_active = 1;
709         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
710 
711         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", more_fragments);
712 
713         // done yet?
714         if (!more_fragments) break;
715 
716         // can send more?
717         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
718     }
719 
720     log_debug("hci_send_acl_packet_fragments loop over");
721 
722     // release buffer now for synchronous transport
723     if (hci_transport_synchronous()){
724         hci_stack->acl_fragmentation_tx_active = 0;
725         hci_release_packet_buffer();
726         hci_emit_transport_packet_sent();
727     }
728 
729     return err;
730 }
731 
732 // pre: caller has reserved the packet buffer
733 int hci_send_acl_packet_buffer(int size){
734 
735     // log_info("hci_send_acl_packet_buffer size %u", size);
736 
737     if (!hci_stack->hci_packet_buffer_reserved) {
738         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
739         return 0;
740     }
741 
742     uint8_t * packet = hci_stack->hci_packet_buffer;
743     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
744 
745     // check for free places on Bluetooth module
746     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
747         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
748         hci_release_packet_buffer();
749         hci_emit_transport_packet_sent();
750         return BTSTACK_ACL_BUFFERS_FULL;
751     }
752 
753     hci_connection_t *connection = hci_connection_for_handle( con_handle);
754     if (!connection) {
755         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
756         hci_release_packet_buffer();
757         hci_emit_transport_packet_sent();
758         return 0;
759     }
760 
761 #ifdef ENABLE_CLASSIC
762     hci_connection_timestamp(connection);
763 #endif
764 
765     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
766 
767     // setup data
768     hci_stack->acl_fragmentation_total_size = size;
769     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
770 
771     return hci_send_acl_packet_fragments(connection);
772 }
773 
774 #ifdef ENABLE_CLASSIC
775 // pre: caller has reserved the packet buffer
776 int hci_send_sco_packet_buffer(int size){
777 
778     // log_info("hci_send_acl_packet_buffer size %u", size);
779 
780     if (!hci_stack->hci_packet_buffer_reserved) {
781         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
782         return 0;
783     }
784 
785     uint8_t * packet = hci_stack->hci_packet_buffer;
786 
787     // skip checks in loopback mode
788     if (!hci_stack->loopback_mode){
789         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
790 
791         // check for free places on Bluetooth module
792         if (!hci_can_send_prepared_sco_packet_now()) {
793             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
794             hci_release_packet_buffer();
795             hci_emit_transport_packet_sent();
796             return BTSTACK_ACL_BUFFERS_FULL;
797         }
798 
799         // track send packet in connection struct
800         hci_connection_t *connection = hci_connection_for_handle( con_handle);
801         if (!connection) {
802             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
803             hci_release_packet_buffer();
804             hci_emit_transport_packet_sent();
805             return 0;
806         }
807 
808         if (hci_have_usb_transport()){
809             // token used
810             hci_stack->sco_can_send_now = 0;
811         } else {
812             if (hci_stack->synchronous_flow_control_enabled){
813                 connection->num_packets_sent++;
814             } else {
815                 connection->sco_tx_ready--;
816             }
817         }
818     }
819 
820     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
821     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
822 
823     if (hci_transport_synchronous()){
824         hci_release_packet_buffer();
825         hci_emit_transport_packet_sent();
826     }
827 
828     return err;
829 }
830 #endif
831 
832 static void acl_handler(uint8_t *packet, int size){
833 
834     // log_info("acl_handler: size %u", size);
835 
836     // get info
837     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
838     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
839     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
840     uint16_t acl_length         = READ_ACL_LENGTH(packet);
841 
842     // ignore non-registered handle
843     if (!conn){
844         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
845         return;
846     }
847 
848     // assert packet is complete
849     if ((acl_length + 4) != size){
850         log_error("hci.c: acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
851         return;
852     }
853 
854 #ifdef ENABLE_CLASSIC
855     // update idle timestamp
856     hci_connection_timestamp(conn);
857 #endif
858 
859 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
860     hci_stack->host_completed_packets = 1;
861     conn->num_packets_completed++;
862 #endif
863 
864     // handle different packet types
865     switch (acl_flags & 0x03) {
866 
867         case 0x01: // continuation fragment
868 
869             // sanity checks
870             if (conn->acl_recombination_pos == 0) {
871                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
872                 return;
873             }
874             if ((conn->acl_recombination_pos + acl_length) > (4 + HCI_ACL_BUFFER_SIZE)){
875                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
876                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
877                 conn->acl_recombination_pos = 0;
878                 return;
879             }
880 
881             // append fragment payload (header already stored)
882             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
883                          &packet[4], acl_length);
884             conn->acl_recombination_pos += acl_length;
885 
886             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
887             //        conn->acl_recombination_pos, conn->acl_recombination_length);
888 
889             // forward complete L2CAP packet if complete.
890             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4 + 4)){ // pos already incl. ACL header
891                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
892                 // reset recombination buffer
893                 conn->acl_recombination_length = 0;
894                 conn->acl_recombination_pos = 0;
895             }
896             break;
897 
898         case 0x02: { // first fragment
899 
900             // sanity check
901             if (conn->acl_recombination_pos) {
902                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
903                 conn->acl_recombination_pos = 0;
904             }
905 
906             // peek into L2CAP packet!
907             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
908 
909             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
910 
911             // compare fragment size to L2CAP packet size
912             if (acl_length >= (l2cap_length + 4)){
913                 // forward fragment as L2CAP packet
914                 hci_emit_acl_packet(packet, acl_length + 4);
915             } else {
916 
917                 if (acl_length > HCI_ACL_BUFFER_SIZE){
918                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
919                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
920                     return;
921                 }
922 
923                 // store first fragment and tweak acl length for complete package
924                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
925                              packet, acl_length + 4);
926                 conn->acl_recombination_pos    = acl_length + 4;
927                 conn->acl_recombination_length = l2cap_length;
928                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
929             }
930             break;
931 
932         }
933         default:
934             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
935             return;
936     }
937 
938     // execute main loop
939     hci_run();
940 }
941 
942 static void hci_shutdown_connection(hci_connection_t *conn){
943     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
944 
945 #ifdef ENABLE_CLASSIC
946 #ifdef ENABLE_SCO_OVER_HCI
947     int addr_type = conn->address_type;
948 #endif
949 #endif
950 
951     btstack_run_loop_remove_timer(&conn->timeout);
952 
953     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
954     btstack_memory_hci_connection_free( conn );
955 
956     // now it's gone
957     hci_emit_nr_connections_changed();
958 
959 #ifdef ENABLE_CLASSIC
960 #ifdef ENABLE_SCO_OVER_HCI
961     // update SCO
962     if (addr_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
963         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
964     }
965 #endif
966 #endif
967 }
968 
969 #ifdef ENABLE_CLASSIC
970 
971 static const uint16_t packet_type_sizes[] = {
972     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
973     HCI_ACL_DH1_SIZE, 0, 0, 0,
974     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
975     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
976 };
977 static const uint8_t  packet_type_feature_requirement_bit[] = {
978      0, // 3 slot packets
979      1, // 5 slot packets
980     25, // EDR 2 mpbs
981     26, // EDR 3 mbps
982     39, // 3 slot EDR packts
983     40, // 5 slot EDR packet
984 };
985 static const uint16_t packet_type_feature_packet_mask[] = {
986     0x0f00, // 3 slot packets
987     0xf000, // 5 slot packets
988     0x1102, // EDR 2 mpbs
989     0x2204, // EDR 3 mbps
990     0x0300, // 3 slot EDR packts
991     0x3000, // 5 slot EDR packet
992 };
993 
994 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
995     // enable packet types based on size
996     uint16_t packet_types = 0;
997     unsigned int i;
998     for (i=0;i<16;i++){
999         if (packet_type_sizes[i] == 0) continue;
1000         if (packet_type_sizes[i] <= buffer_size){
1001             packet_types |= 1 << i;
1002         }
1003     }
1004     // disable packet types due to missing local supported features
1005     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1006         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1007         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1008         if (feature_set) continue;
1009         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1010         packet_types &= ~packet_type_feature_packet_mask[i];
1011     }
1012     // flip bits for "may not be used"
1013     packet_types ^= 0x3306;
1014     return packet_types;
1015 }
1016 
1017 uint16_t hci_usable_acl_packet_types(void){
1018     return hci_stack->packet_types;
1019 }
1020 #endif
1021 
1022 uint8_t* hci_get_outgoing_packet_buffer(void){
1023     // hci packet buffer is >= acl data packet length
1024     return hci_stack->hci_packet_buffer;
1025 }
1026 
1027 uint16_t hci_max_acl_data_packet_length(void){
1028     return hci_stack->acl_data_packet_length;
1029 }
1030 
1031 #ifdef ENABLE_CLASSIC
1032 int hci_extended_sco_link_supported(void){
1033     // No. 31, byte 3, bit 7
1034     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1035 }
1036 #endif
1037 
1038 int hci_non_flushable_packet_boundary_flag_supported(void){
1039     // No. 54, byte 6, bit 6
1040     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
1041 }
1042 
1043 static int gap_ssp_supported(void){
1044     // No. 51, byte 6, bit 3
1045     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
1046 }
1047 
1048 static int hci_classic_supported(void){
1049 #ifdef ENABLE_CLASSIC
1050     // No. 37, byte 4, bit 5, = No BR/EDR Support
1051     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1052 #else
1053     return 0;
1054 #endif
1055 }
1056 
1057 static int hci_le_supported(void){
1058 #ifdef ENABLE_BLE
1059     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1060     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
1061 #else
1062     return 0;
1063 #endif
1064 }
1065 
1066 #ifdef ENABLE_BLE
1067 
1068 /**
1069  * @brief Get addr type and address used for LE in Advertisements, Scan Responses,
1070  */
1071 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1072     *addr_type = hci_stack->le_own_addr_type;
1073     if (hci_stack->le_own_addr_type){
1074         (void)memcpy(addr, hci_stack->le_random_address, 6);
1075     } else {
1076         (void)memcpy(addr, hci_stack->local_bd_addr, 6);
1077     }
1078 }
1079 
1080 #ifdef ENABLE_LE_CENTRAL
1081 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1082 
1083     int offset = 3;
1084     int num_reports = packet[offset];
1085     offset += 1;
1086 
1087     int i;
1088     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1089     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1090     for (i=0; (i<num_reports) && (offset < size);i++){
1091         // sanity checks on data_length:
1092         uint8_t data_length = packet[offset + 8];
1093         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1094         if ((offset + 9 + data_length + 1) > size)    return;
1095         // setup event
1096         uint8_t event_size = 10 + data_length;
1097         int pos = 0;
1098         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1099         event[pos++] = event_size;
1100         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1101         offset += 8;
1102         pos += 8;
1103         event[pos++] = packet[offset + 1 + data_length]; // rssi
1104         event[pos++] = data_length;
1105         offset++;
1106         (void)memcpy(&event[pos], &packet[offset], data_length);
1107         pos +=    data_length;
1108         offset += data_length + 1; // rssi
1109         hci_emit_event(event, pos, 1);
1110     }
1111 }
1112 #endif
1113 #endif
1114 
1115 #ifdef ENABLE_BLE
1116 #ifdef ENABLE_LE_PERIPHERAL
1117 static void hci_reenable_advertisements_if_needed(void){
1118     if (!hci_stack->le_advertisements_active && hci_stack->le_advertisements_enabled){
1119         // get number of active le slave connections
1120         int num_slave_connections = 0;
1121         btstack_linked_list_iterator_t it;
1122         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1123         while (btstack_linked_list_iterator_has_next(&it)){
1124             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1125             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1126             if (con->state != OPEN) continue;
1127             if (con->role  != HCI_ROLE_SLAVE) continue;
1128             if (!hci_is_le_connection(con)) continue;
1129             num_slave_connections++;
1130         }
1131         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1132         if (num_slave_connections < hci_stack->le_max_number_peripheral_connections){
1133             hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
1134         }
1135     }
1136 }
1137 #endif
1138 #endif
1139 
1140 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1141 
1142 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1143     if (!hci_stack->config) return 0;
1144     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1145     // Limit baud rate for Broadcom chipsets to 3 mbps
1146     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1147         baud_rate = 3000000;
1148     }
1149     return baud_rate;
1150 }
1151 
1152 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1153     UNUSED(ds);
1154 
1155     switch (hci_stack->substate){
1156         case HCI_INIT_W4_SEND_RESET:
1157             log_info("Resend HCI Reset");
1158             hci_stack->substate = HCI_INIT_SEND_RESET;
1159             hci_stack->num_cmd_packets = 1;
1160             hci_run();
1161             break;
1162         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1163             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1164             if (hci_stack->hci_transport->reset_link){
1165                 hci_stack->hci_transport->reset_link();
1166             }
1167 
1168             /* fall through */
1169 
1170         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1171             log_info("Resend HCI Reset - CSR Warm Boot");
1172             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1173             hci_stack->num_cmd_packets = 1;
1174             hci_run();
1175             break;
1176         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1177             if (hci_stack->hci_transport->set_baudrate){
1178                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1179                 log_info("Local baud rate change to %"PRIu32"(timeout handler)", baud_rate);
1180                 hci_stack->hci_transport->set_baudrate(baud_rate);
1181             }
1182             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1183             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1184                 if (hci_stack->hci_transport->reset_link){
1185                     log_info("Link Reset");
1186                     hci_stack->hci_transport->reset_link();
1187                 }
1188                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1189                 hci_run();
1190             }
1191             break;
1192         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1193             // otherwise continue
1194             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1195             hci_send_cmd(&hci_read_local_supported_commands);
1196             break;
1197         default:
1198             break;
1199     }
1200 }
1201 #endif
1202 
1203 static void hci_initializing_next_state(void){
1204     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1205 }
1206 
1207 // assumption: hci_can_send_command_packet_now() == true
1208 static void hci_initializing_run(void){
1209     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1210     switch (hci_stack->substate){
1211         case HCI_INIT_SEND_RESET:
1212             hci_state_reset();
1213 
1214 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1215             // prepare reset if command complete not received in 100ms
1216             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1217             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1218             btstack_run_loop_add_timer(&hci_stack->timeout);
1219 #endif
1220             // send command
1221             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1222             hci_send_cmd(&hci_reset);
1223             break;
1224         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1225             hci_send_cmd(&hci_read_local_version_information);
1226             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1227             break;
1228         case HCI_INIT_SEND_READ_LOCAL_NAME:
1229             hci_send_cmd(&hci_read_local_name);
1230             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1231             break;
1232 
1233 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1234         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1235             hci_state_reset();
1236             // prepare reset if command complete not received in 100ms
1237             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1238             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1239             btstack_run_loop_add_timer(&hci_stack->timeout);
1240             // send command
1241             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1242             hci_send_cmd(&hci_reset);
1243             break;
1244         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1245             hci_state_reset();
1246             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1247             hci_send_cmd(&hci_reset);
1248             break;
1249         case HCI_INIT_SEND_BAUD_CHANGE: {
1250             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1251             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1252             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1253             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1254             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1255             // STLC25000D: baudrate change happens within 0.5 s after command was send,
1256             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1257             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1258                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1259                 btstack_run_loop_add_timer(&hci_stack->timeout);
1260             }
1261             break;
1262         }
1263         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1264             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1265             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1266             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1267             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1268             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1269             break;
1270         }
1271         case HCI_INIT_CUSTOM_INIT:
1272             // Custom initialization
1273             if (hci_stack->chipset && hci_stack->chipset->next_command){
1274                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1275                 int send_cmd = 0;
1276                 switch (hci_stack->chipset_result){
1277                     case BTSTACK_CHIPSET_VALID_COMMAND:
1278                         send_cmd = 1;
1279                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1280                         break;
1281                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1282                         send_cmd = 1;
1283                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1284                         log_info("CSR Warm Boot");
1285                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1286                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1287                         btstack_run_loop_add_timer(&hci_stack->timeout);
1288                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1289                             && hci_stack->config
1290                             && hci_stack->chipset
1291                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1292                             && hci_stack->hci_transport->set_baudrate
1293                             && hci_transport_uart_get_main_baud_rate()){
1294                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1295                         } else {
1296                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1297                         }
1298                         break;
1299                     default:
1300                         break;
1301                 }
1302 
1303                 if (send_cmd){
1304                     int size = 3 + hci_stack->hci_packet_buffer[2];
1305                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1306                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1307                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1308                     break;
1309                 }
1310                 log_info("Init script done");
1311 
1312                 // Init script download on Broadcom chipsets causes:
1313                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1314                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1315                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1316 
1317                     // - baud rate to reset, restore UART baud rate if needed
1318                     int need_baud_change = hci_stack->config
1319                         && hci_stack->chipset
1320                         && hci_stack->chipset->set_baudrate_command
1321                         && hci_stack->hci_transport->set_baudrate
1322                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1323                     if (need_baud_change) {
1324                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1325                         log_info("Local baud rate change to %"PRIu32" after init script (bcm)", baud_rate);
1326                         hci_stack->hci_transport->set_baudrate(baud_rate);
1327                     }
1328 
1329                     uint16_t bcm_delay_ms = 300;
1330                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1331                     //   -> Work around: wait here.
1332                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1333                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1334                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1335                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1336                     btstack_run_loop_add_timer(&hci_stack->timeout);
1337                     break;
1338                 }
1339             }
1340             // otherwise continue
1341             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1342             hci_send_cmd(&hci_read_local_supported_commands);
1343             break;
1344         case HCI_INIT_SET_BD_ADDR:
1345             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1346             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1347             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1348             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1349             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1350             break;
1351 #endif
1352 
1353         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1354             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1355             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1356             hci_send_cmd(&hci_read_local_supported_commands);
1357             break;
1358         case HCI_INIT_READ_BD_ADDR:
1359             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1360             hci_send_cmd(&hci_read_bd_addr);
1361             break;
1362         case HCI_INIT_READ_BUFFER_SIZE:
1363             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1364             hci_send_cmd(&hci_read_buffer_size);
1365             break;
1366         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1367             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1368             hci_send_cmd(&hci_read_local_supported_features);
1369             break;
1370 
1371 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1372         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1373             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1374             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1375             break;
1376         case HCI_INIT_HOST_BUFFER_SIZE:
1377             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1378             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1379                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1380             break;
1381 #endif
1382 
1383         case HCI_INIT_SET_EVENT_MASK:
1384             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1385             if (hci_le_supported()){
1386                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1387             } else {
1388                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1389                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1390             }
1391             break;
1392 
1393 #ifdef ENABLE_CLASSIC
1394         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1395             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1396             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1397             break;
1398         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1399             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1400             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1401             break;
1402         case HCI_INIT_WRITE_DEFAULT_LINK_POLICY_SETTING:
1403             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_LINK_POLICY_SETTING;
1404             hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1405             break;
1406         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1407             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1408             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1409             break;
1410         case HCI_INIT_WRITE_LOCAL_NAME: {
1411             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1412             hci_reserve_packet_buffer();
1413             uint8_t * packet = hci_stack->hci_packet_buffer;
1414             // construct HCI Command and send
1415             uint16_t opcode = hci_write_local_name.opcode;
1416             hci_stack->last_cmd_opcode = opcode;
1417             packet[0] = opcode & 0xff;
1418             packet[1] = opcode >> 8;
1419             packet[2] = DEVICE_NAME_LEN;
1420             memset(&packet[3], 0, DEVICE_NAME_LEN);
1421             uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1422             uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1423             // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1424             (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1425             // expand '00:00:00:00:00:00' in name with bd_addr
1426             btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1427             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1428             break;
1429         }
1430         case HCI_INIT_WRITE_EIR_DATA: {
1431             hci_stack->substate = HCI_INIT_W4_WRITE_EIR_DATA;
1432             hci_reserve_packet_buffer();
1433             uint8_t * packet = hci_stack->hci_packet_buffer;
1434             // construct HCI Command in-place and send
1435             uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1436             hci_stack->last_cmd_opcode = opcode;
1437             uint16_t offset = 0;
1438             packet[offset++] = opcode & 0xff;
1439             packet[offset++] = opcode >> 8;
1440             packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1441             packet[offset++] = 0;  // FEC not required
1442             memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1443             if (hci_stack->eir_data){
1444                 // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1445                 ad_context_t context;
1446                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1447                     uint8_t data_type   = ad_iterator_get_data_type(&context);
1448                     uint8_t size        = ad_iterator_get_data_len(&context);
1449                     const uint8_t *data = ad_iterator_get_data(&context);
1450                     // copy item
1451                     packet[offset++] = size + 1;
1452                     packet[offset++] = data_type;
1453                     memcpy(&packet[offset], data, size);
1454                     // update name item
1455                     if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1456                         btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1457                     }
1458                     offset += size;
1459                 }
1460             } else {
1461                 uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1462                 uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1463                 packet[offset++] = bytes_to_copy + 1;
1464                 packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1465                 (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1466                 // expand '00:00:00:00:00:00' in name with bd_addr
1467                 btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1468             }
1469             hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1470             break;
1471         }
1472         case HCI_INIT_WRITE_INQUIRY_MODE:
1473             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1474             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1475             break;
1476         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1477             hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1478             hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1479             break;
1480         case HCI_INIT_WRITE_SCAN_ENABLE:
1481             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1482             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1483             break;
1484         // only sent if ENABLE_SCO_OVER_HCI is defined
1485         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1486             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1487             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1488             break;
1489         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1490             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1491             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1492             break;
1493         // only sent if ENABLE_SCO_OVER_HCI and manufacturer is Broadcom
1494         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1495             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1496             log_info("BCM: Route SCO data via HCI transport");
1497             hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1498             break;
1499 
1500 #endif
1501 #ifdef ENABLE_BLE
1502         // LE INIT
1503         case HCI_INIT_LE_READ_BUFFER_SIZE:
1504             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1505             hci_send_cmd(&hci_le_read_buffer_size);
1506             break;
1507         case HCI_INIT_LE_SET_EVENT_MASK:
1508             hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1509             hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1510             break;
1511         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1512             // LE Supported Host = 1, Simultaneous Host = 0
1513             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1514             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1515             break;
1516 #endif
1517 
1518 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1519         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1520             hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1521             hci_send_cmd(&hci_le_read_maximum_data_length);
1522             break;
1523         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1524             hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1525             hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1526             break;
1527 #endif
1528 
1529 #ifdef ENABLE_LE_CENTRAL
1530         case HCI_INIT_READ_WHITE_LIST_SIZE:
1531             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1532             hci_send_cmd(&hci_le_read_white_list_size);
1533             break;
1534         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1535             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, own address type, accept all advs
1536             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1537             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);
1538             break;
1539 #endif
1540         default:
1541             return;
1542     }
1543 }
1544 
1545 static void hci_init_done(void){
1546     // done. tell the app
1547     log_info("hci_init_done -> HCI_STATE_WORKING");
1548     hci_stack->state = HCI_STATE_WORKING;
1549     hci_emit_state();
1550     hci_run();
1551 }
1552 
1553 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1554     bool command_completed = false;
1555     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1556         uint16_t opcode = little_endian_read_16(packet,3);
1557         if (opcode == hci_stack->last_cmd_opcode){
1558             command_completed = true;
1559             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1560         } else {
1561             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1562         }
1563     }
1564 
1565     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1566         uint8_t  status = packet[2];
1567         uint16_t opcode = little_endian_read_16(packet,4);
1568         if (opcode == hci_stack->last_cmd_opcode){
1569             if (status){
1570                 command_completed = true;
1571                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1572             } else {
1573                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1574             }
1575         } else {
1576             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1577         }
1578     }
1579 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1580     // Vendor == CSR
1581     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1582         // TODO: track actual command
1583         command_completed = true;
1584     }
1585 
1586     // Vendor == Toshiba
1587     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1588         // TODO: track actual command
1589         command_completed = true;
1590         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1591         hci_stack->num_cmd_packets = 1;
1592     }
1593 #endif
1594 
1595     return command_completed;
1596 }
1597 
1598 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1599 
1600     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1601 
1602     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1603 
1604 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1605 
1606     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1607     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1608     //
1609     // HCI Reset
1610     // Timeout 100 ms
1611     // HCI Reset
1612     // Command Complete Reset
1613     // HCI Read Local Version Information
1614     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1615     // hang...
1616     //
1617     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1618     if (!command_completed
1619             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1620             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1621 
1622         uint16_t opcode = little_endian_read_16(packet,3);
1623         if (opcode == hci_reset.opcode){
1624             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1625             return;
1626         }
1627     }
1628 
1629     // CSR & H5
1630     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1631     if (!command_completed
1632             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1633             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1634 
1635         uint16_t opcode = little_endian_read_16(packet,3);
1636         if (opcode == hci_reset.opcode){
1637             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1638             return;
1639         }
1640     }
1641 
1642     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1643     // fix: Correct substate and behave as command below
1644     if (command_completed){
1645         switch (hci_stack->substate){
1646             case HCI_INIT_SEND_RESET:
1647                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1648                 break;
1649             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1650                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1651                 break;
1652             default:
1653                 break;
1654         }
1655     }
1656 
1657 #endif
1658 
1659     if (!command_completed) return;
1660 
1661     bool need_baud_change = false;
1662     bool need_addr_change = false;
1663 
1664 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1665     need_baud_change = hci_stack->config
1666                         && hci_stack->chipset
1667                         && hci_stack->chipset->set_baudrate_command
1668                         && hci_stack->hci_transport->set_baudrate
1669                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1670 
1671     need_addr_change = hci_stack->custom_bd_addr_set
1672                         && hci_stack->chipset
1673                         && hci_stack->chipset->set_bd_addr_command;
1674 #endif
1675 
1676     switch(hci_stack->substate){
1677 
1678 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1679         case HCI_INIT_SEND_RESET:
1680             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1681             // fix: just correct substate and behave as command below
1682             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1683             btstack_run_loop_remove_timer(&hci_stack->timeout);
1684             break;
1685         case HCI_INIT_W4_SEND_RESET:
1686             btstack_run_loop_remove_timer(&hci_stack->timeout);
1687             break;
1688         case HCI_INIT_W4_SEND_READ_LOCAL_NAME:
1689             log_info("Received local name, need baud change %d", (int) need_baud_change);
1690             if (need_baud_change){
1691                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1692                 return;
1693             }
1694             // skip baud change
1695             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1696             return;
1697         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1698             // for STLC2500D, baud rate change already happened.
1699             // for others, baud rate gets changed now
1700             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1701                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1702                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change)", baud_rate);
1703                 hci_stack->hci_transport->set_baudrate(baud_rate);
1704             }
1705             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1706             return;
1707         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1708             btstack_run_loop_remove_timer(&hci_stack->timeout);
1709             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1710             return;
1711         case HCI_INIT_W4_CUSTOM_INIT:
1712             // repeat custom init
1713             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1714             return;
1715 #else
1716         case HCI_INIT_W4_SEND_RESET:
1717             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1718             return ;
1719 #endif
1720 
1721         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1722             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1723               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1724                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1725                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1726                 return;
1727             }
1728             if (need_addr_change){
1729                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1730                 return;
1731             }
1732             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1733             return;
1734 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
1735         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1736             if (need_baud_change){
1737                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1738                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change_bcm))", baud_rate);
1739                 hci_stack->hci_transport->set_baudrate(baud_rate);
1740             }
1741             if (need_addr_change){
1742                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1743                 return;
1744             }
1745             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1746             return;
1747         case HCI_INIT_W4_SET_BD_ADDR:
1748             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1749             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1750             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1751                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1752                 return;
1753             }
1754             // skipping st warm boot
1755             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1756             return;
1757         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1758             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1759             return;
1760 #endif
1761         case HCI_INIT_W4_READ_BD_ADDR:
1762             // only read buffer size if supported
1763             if (hci_stack->local_supported_commands[0] & 0x01) {
1764                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1765                 return;
1766             }
1767             // skipping read buffer size
1768             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1769             return;
1770         case HCI_INIT_W4_SET_EVENT_MASK:
1771             // skip Classic init commands for LE only chipsets
1772             if (!hci_classic_supported()){
1773 #ifdef ENABLE_BLE
1774                 if (hci_le_supported()){
1775                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1776                     return;
1777                 }
1778 #endif
1779                 log_error("Neither BR/EDR nor LE supported");
1780                 hci_init_done();
1781                 return;
1782             }
1783             if (!gap_ssp_supported()){
1784                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1785                 return;
1786             }
1787             break;
1788 #ifdef ENABLE_BLE
1789         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1790             // skip write le host if not supported (e.g. on LE only EM9301)
1791             if (hci_stack->local_supported_commands[0] & 0x02) break;
1792             hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1793             return;
1794 
1795 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1796         case HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED:
1797             log_info("Supported commands %x", hci_stack->local_supported_commands[0] & 0x30);
1798             if ((hci_stack->local_supported_commands[0] & 0x30) == 0x30){
1799                 hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
1800                 return;
1801             }
1802             // explicit fall through to reduce repetitions
1803 
1804 #ifdef ENABLE_LE_CENTRAL
1805             hci_stack->substate = HCI_INIT_READ_WHITE_LIST_SIZE;
1806 #else
1807             hci_init_done();
1808 #endif
1809             return;
1810 #endif  /* ENABLE_LE_DATA_LENGTH_EXTENSION */
1811 
1812 #endif  /* ENABLE_BLE */
1813 
1814         case HCI_INIT_W4_WRITE_INQUIRY_MODE:
1815             // skip write secure connections host support if not supported or disabled
1816             if (!hci_stack->secure_connections_enable || (hci_stack->local_supported_commands[1] & 0x02) == 0) {
1817                 hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;
1818                 return;
1819             }
1820             break;
1821 
1822 #ifdef ENABLE_SCO_OVER_HCI
1823         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1824             // skip write synchronous flow control if not supported
1825             if (hci_stack->local_supported_commands[0] & 0x04) break;
1826             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1827 
1828             /* fall through */
1829 
1830         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1831             // skip write default erroneous data reporting if not supported
1832             if (hci_stack->local_supported_commands[0] & 0x08) break;
1833             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1834 
1835             /* fall through */
1836 
1837         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1838             // skip bcm set sco pcm config on non-Broadcom chipsets
1839             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) break;
1840             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1841 
1842             /* fall through */
1843 
1844         case HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT:
1845             if (!hci_le_supported()){
1846                 // SKIP LE init for Classic only configuration
1847                 hci_init_done();
1848                 return;
1849             }
1850             break;
1851 
1852 #else /* !ENABLE_SCO_OVER_HCI */
1853 
1854         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1855 #ifdef ENABLE_BLE
1856             if (hci_le_supported()){
1857                 hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE;
1858                 return;
1859             }
1860 #endif
1861             // SKIP LE init for Classic only configuration
1862             hci_init_done();
1863             return;
1864 #endif /* ENABLE_SCO_OVER_HCI */
1865 
1866 // avoid compile error due to duplicate cases: HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT == HCI_INIT_DONE-1
1867 #if defined(ENABLE_BLE) || defined(ENABLE_LE_DATA_LENGTH_EXTENSION) || defined(ENABLE_LE_CENTRAL)
1868         // Response to command before init done state -> init done
1869         case (HCI_INIT_DONE-1):
1870             hci_init_done();
1871             return;
1872 #endif
1873 
1874         default:
1875             break;
1876     }
1877     hci_initializing_next_state();
1878 }
1879 
1880 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
1881     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
1882     bd_addr_t bd_address;
1883     (void)memcpy(&bd_address, conn->address, 6);
1884 
1885 #ifdef ENABLE_CLASSIC
1886     // cache needed data
1887     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1888 #endif
1889 
1890     // connection failed, remove entry
1891     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1892     btstack_memory_hci_connection_free( conn );
1893 
1894 #ifdef ENABLE_CLASSIC
1895     // notify client if dedicated bonding
1896     if (notify_dedicated_bonding_failed){
1897         log_info("hci notify_dedicated_bonding_failed");
1898         hci_emit_dedicated_bonding_result(bd_address, status);
1899     }
1900 
1901     // if authentication error, also delete link key
1902     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
1903         gap_drop_link_key_for_bd_addr(bd_address);
1904     }
1905 #endif
1906 }
1907 
1908 #ifdef ENABLE_CLASSIC
1909 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
1910     // SSP Controller
1911     if (features[6] & (1 << 3)){
1912         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
1913     }
1914     // eSCO
1915     if (features[3] & (1<<7)){
1916         conn->remote_supported_features[0] |= 1;
1917     }
1918     // Extended features
1919     if (features[7] & (1<<7)){
1920         conn->remote_supported_features[0] |= 2;
1921     }
1922 }
1923 
1924 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
1925     // SSP Host
1926     if (features[0] & (1 << 0)){
1927         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
1928     }
1929     // SC Host
1930     if (features[0] & (1 << 3)){
1931         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
1932     }
1933 }
1934 
1935 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
1936     // SC Controller
1937     if (features[1] & (1 << 0)){
1938         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
1939     }
1940 }
1941 
1942 static void hci_handle_remote_features_received(hci_connection_t * conn){
1943     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1944     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
1945     if (conn->bonding_flags & BONDING_DEDICATED){
1946         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1947     }
1948 }
1949 #endif
1950 
1951 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
1952     // handle BT initialization
1953     if (hci_stack->state == HCI_STATE_INITIALIZING) {
1954         hci_initializing_event_handler(packet, size);
1955     }
1956 
1957     // help with BT sleep
1958     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
1959         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
1960         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
1961         hci_initializing_next_state();
1962     }
1963 }
1964 
1965 #ifdef ENABLE_CLASSIC
1966 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
1967     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1968     conn->encryption_key_size = encryption_key_size;
1969 
1970     if ((conn->authentication_flags & CONNECTION_AUTHENTICATED) != 0) {
1971         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
1972         return;
1973     }
1974 
1975     // Request Authentication if not already done
1976     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
1977     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1978 }
1979 #endif
1980 
1981 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
1982 
1983     uint16_t manufacturer;
1984 #ifdef ENABLE_CLASSIC
1985     hci_con_handle_t handle;
1986     hci_connection_t * conn;
1987     uint8_t status;
1988 #endif
1989     // get num cmd packets - limit to 1 to reduce complexity
1990     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
1991 
1992     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
1993     switch (opcode){
1994         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
1995             if (packet[5]) break;
1996             // terminate, name 248 chars
1997             packet[6+248] = 0;
1998             log_info("local name: %s", &packet[6]);
1999             break;
2000         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2001             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2002             if (hci_stack->state != HCI_STATE_INITIALIZING) break;
2003             uint16_t acl_len = little_endian_read_16(packet, 6);
2004             uint16_t sco_len = packet[8];
2005 
2006             // determine usable ACL/SCO payload size
2007             hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2008             hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2009 
2010             hci_stack->acl_packets_total_num  = little_endian_read_16(packet, 9);
2011             hci_stack->sco_packets_total_num  = little_endian_read_16(packet, 11);
2012 
2013             log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2014                      acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2015                      hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2016             break;
2017         case HCI_OPCODE_HCI_READ_RSSI:
2018             if (packet[5] == ERROR_CODE_SUCCESS){
2019                 uint8_t event[5];
2020                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2021                 event[1] = 3;
2022                 (void)memcpy(&event[2], &packet[6], 3);
2023                 hci_emit_event(event, sizeof(event), 1);
2024             }
2025             break;
2026 #ifdef ENABLE_BLE
2027         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2028             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2029             hci_stack->le_acl_packets_total_num = packet[8];
2030             // determine usable ACL payload size
2031             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2032                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2033             }
2034             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2035             break;
2036 #endif
2037 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2038         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2039             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2040             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2041             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);
2042             break;
2043 #endif
2044 #ifdef ENABLE_LE_CENTRAL
2045         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2046             hci_stack->le_whitelist_capacity = packet[6];
2047             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2048             break;
2049 #endif
2050         case HCI_OPCODE_HCI_READ_BD_ADDR:
2051             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2052             log_info("Local Address, Status: 0x%02x: Addr: %s", packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
2053 #ifdef ENABLE_CLASSIC
2054             if (hci_stack->link_key_db){
2055                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2056             }
2057 #endif
2058             break;
2059 #ifdef ENABLE_CLASSIC
2060         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2061             hci_emit_discoverable_enabled(hci_stack->discoverable);
2062             break;
2063         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2064             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2065                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2066                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2067                 hci_emit_event(event, sizeof(event), 1);
2068             }
2069             break;
2070 #endif
2071         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2072             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2073 
2074 #ifdef ENABLE_CLASSIC
2075             // determine usable ACL packet types based on host buffer size and supported features
2076             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2077             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2078 #endif
2079             // Classic/LE
2080             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2081             break;
2082         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2083             manufacturer = little_endian_read_16(packet, 10);
2084             // map Cypress to Broadcom
2085             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2086                 log_info("Treat Cypress as Broadcom");
2087                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2088                 little_endian_store_16(packet, 10, manufacturer);
2089             }
2090             hci_stack->manufacturer = manufacturer;
2091             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2092             break;
2093         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2094             hci_stack->local_supported_commands[0] =
2095                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+14] & 0x80) >> 7) |  // bit 0 = Octet 14, bit 7 / Read Buffer Size
2096                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+24] & 0x40) >> 5) |  // bit 1 = Octet 24, bit 6 / Write Le Host Supported
2097                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+10] & 0x10) >> 2) |  // bit 2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2098                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+18] & 0x08)     ) |  // bit 3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2099                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x01) << 4) |  // bit 4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2100                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+35] & 0x08) << 2) |  // bit 5 = Octet 35, bit 3 / LE Read Maximum Data Length
2101                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+35] & 0x20) << 1) |  // bit 6 = Octet 35, bit 5 / LE Set Default PHY
2102                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+20] & 0x10) << 3);   // bit 7 = Octet 20, bit 4 / Read Encryption Key Size
2103             hci_stack->local_supported_commands[1] =
2104                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+ 2] & 0x40) >> 6) |  // bit 8 = Octet  2, bit 6 / Read Remote Extended Features
2105                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+32] & 0x08) >> 2);   // bit 9 = Octet 32, bit 3 / Write Secure Connections Host
2106             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2107             break;
2108 #ifdef ENABLE_CLASSIC
2109         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2110             if (packet[5]) return;
2111             hci_stack->synchronous_flow_control_enabled = 1;
2112             break;
2113         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2114             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2115             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2116             conn   = hci_connection_for_handle(handle);
2117             if (!conn) return;
2118             uint8_t key_size = 0;
2119             if (status == 0){
2120                 key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2121                 log_info("Handle %x04x key Size: %u", handle, key_size);
2122             } else {
2123                 log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2124             }
2125             hci_handle_read_encryption_key_size_complete(conn, key_size);
2126             break;
2127 #endif
2128         default:
2129             break;
2130     }
2131 }
2132 
2133 static void event_handler(uint8_t *packet, int size){
2134 
2135     uint16_t event_length = packet[1];
2136 
2137     // assert packet is complete
2138     if (size != (event_length + 2)){
2139         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2140         return;
2141     }
2142 
2143     bd_addr_t addr;
2144     bd_addr_type_t addr_type;
2145     hci_con_handle_t handle;
2146     hci_connection_t * conn;
2147     int i;
2148     int create_connection_cmd;
2149 
2150 #ifdef ENABLE_CLASSIC
2151     uint8_t link_type;
2152 #endif
2153 
2154     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2155 
2156     switch (hci_event_packet_get_type(packet)) {
2157 
2158         case HCI_EVENT_COMMAND_COMPLETE:
2159             handle_command_complete_event(packet, size);
2160             break;
2161 
2162         case HCI_EVENT_COMMAND_STATUS:
2163             // get num cmd packets - limit to 1 to reduce complexity
2164             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2165 
2166             // check command status to detected failed outgoing connections
2167             create_connection_cmd = 0;
2168 #ifdef ENABLE_CLASSIC
2169             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2170                 create_connection_cmd = 1;
2171             }
2172 #endif
2173 #ifdef ENABLE_LE_CENTRAL
2174             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2175                 create_connection_cmd = 1;
2176             }
2177 #endif
2178             if (create_connection_cmd) {
2179                 uint8_t status = hci_event_command_status_get_status(packet);
2180                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, hci_stack->outgoing_addr_type);
2181                 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);
2182 
2183                 // reset outgoing address info
2184                 memset(hci_stack->outgoing_addr, 0, 6);
2185                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2186 
2187                 // error => outgoing connection failed
2188                 if ((conn != NULL) && (status != 0)){
2189                     hci_handle_connection_failed(conn, status);
2190                 }
2191             }
2192             break;
2193 
2194         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2195             if (size < 3) return;
2196             uint16_t num_handles = packet[2];
2197             if (size != (3 + num_handles * 4)) return;
2198             uint16_t offset = 3;
2199             for (i=0; i<num_handles;i++){
2200                 handle = little_endian_read_16(packet, offset) & 0x0fff;
2201                 offset += 2;
2202                 uint16_t num_packets = little_endian_read_16(packet, offset);
2203                 offset += 2;
2204 
2205                 conn = hci_connection_for_handle(handle);
2206                 if (!conn){
2207                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2208                     continue;
2209                 }
2210 
2211                 if (conn->num_packets_sent >= num_packets){
2212                     conn->num_packets_sent -= num_packets;
2213                 } else {
2214                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2215                     conn->num_packets_sent = 0;
2216                 }
2217                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2218 
2219 #ifdef ENABLE_CLASSIC
2220                 // For SCO, we do the can_send_now_check here
2221                 hci_notify_if_sco_can_send_now();
2222 #endif
2223             }
2224             break;
2225         }
2226 
2227 #ifdef ENABLE_CLASSIC
2228         case HCI_EVENT_INQUIRY_COMPLETE:
2229             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2230                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2231                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2232                 hci_emit_event(event, sizeof(event), 1);
2233             }
2234             break;
2235         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2236             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2237                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2238             }
2239             break;
2240         case HCI_EVENT_CONNECTION_REQUEST:
2241             reverse_bd_addr(&packet[2], addr);
2242             if (hci_stack->gap_classic_accept_callback != NULL){
2243                 if ((*hci_stack->gap_classic_accept_callback)(addr) == 0){
2244                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2245                     bd_addr_copy(hci_stack->decline_addr, addr);
2246                     break;
2247                 }
2248             }
2249 
2250             // TODO: eval COD 8-10
2251             link_type = packet[11];
2252             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
2253             addr_type = (link_type == 1) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2254             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2255             if (!conn) {
2256                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2257             }
2258             if (!conn) {
2259                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2260                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2261                 bd_addr_copy(hci_stack->decline_addr, addr);
2262                 break;
2263             }
2264             conn->role  = HCI_ROLE_SLAVE;
2265             conn->state = RECEIVED_CONNECTION_REQUEST;
2266             // store info about eSCO
2267             if (link_type == 0x02){
2268                 conn->remote_supported_features[0] |= 1;
2269             }
2270             hci_run();
2271             break;
2272 
2273         case HCI_EVENT_CONNECTION_COMPLETE:
2274             // Connection management
2275             reverse_bd_addr(&packet[5], addr);
2276             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2277             addr_type = BD_ADDR_TYPE_ACL;
2278             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2279             if (conn) {
2280                 if (!packet[2]){
2281                     conn->state = OPEN;
2282                     conn->con_handle = little_endian_read_16(packet, 3);
2283 
2284                     // queue get remote feature
2285                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2286 
2287                     // queue set supervision timeout if we're master
2288                     if ((hci_stack->link_supervision_timeout != 0) && (conn->role == HCI_ROLE_MASTER)){
2289                         connectionSetAuthenticationFlags(conn, WRITE_SUPERVISION_TIMEOUT);
2290                     }
2291 
2292                     // restart timer
2293                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2294                     btstack_run_loop_add_timer(&conn->timeout);
2295 
2296                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2297 
2298                     hci_emit_nr_connections_changed();
2299                 } else {
2300                     // connection failed
2301                     hci_handle_connection_failed(conn, packet[2]);
2302                 }
2303             }
2304             break;
2305 
2306         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2307             reverse_bd_addr(&packet[5], addr);
2308             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2309             if (packet[2]){
2310                 // connection failed
2311                 break;
2312             }
2313             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2314             if (!conn) {
2315                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2316             }
2317             if (!conn) {
2318                 break;
2319             }
2320             conn->state = OPEN;
2321             conn->con_handle = little_endian_read_16(packet, 3);
2322 
2323 #ifdef ENABLE_SCO_OVER_HCI
2324             // update SCO
2325             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2326                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2327             }
2328             // trigger can send now
2329             if (hci_have_usb_transport()){
2330                 hci_stack->sco_can_send_now = 1;
2331             }
2332 #endif
2333             break;
2334 
2335         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2336             handle = little_endian_read_16(packet, 3);
2337             conn = hci_connection_for_handle(handle);
2338             if (!conn) break;
2339             if (!packet[2]){
2340                 const uint8_t * features = &packet[5];
2341                 hci_handle_remote_features_page_0(conn, features);
2342 
2343                 // read extended features if possible
2344                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2345                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2346                     break;
2347                 }
2348             }
2349             hci_handle_remote_features_received(conn);
2350             break;
2351 
2352         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2353             handle = little_endian_read_16(packet, 3);
2354             conn = hci_connection_for_handle(handle);
2355             if (!conn) break;
2356             // status = ok, page = 1
2357             if (!packet[2]) {
2358                 uint8_t page_number = packet[5];
2359                 uint8_t maximum_page_number = packet[6];
2360                 const uint8_t * features = &packet[7];
2361                 bool done = false;
2362                 switch (page_number){
2363                     case 1:
2364                         hci_handle_remote_features_page_1(conn, features);
2365                         if (maximum_page_number >= 2){
2366                             // get Secure Connections (Controller) from Page 2 if available
2367                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2368                         } else {
2369                             // otherwise, assume SC (Controller) == SC (Host)
2370                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2371                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2372                             }
2373                             done = true;
2374                         }
2375                         break;
2376                     case 2:
2377                         hci_handle_remote_features_page_2(conn, features);
2378                         done = true;
2379                         break;
2380                     default:
2381                         break;
2382                 }
2383                 if (!done) break;
2384             }
2385             hci_handle_remote_features_received(conn);
2386             break;
2387 
2388         case HCI_EVENT_LINK_KEY_REQUEST:
2389             log_info("HCI_EVENT_LINK_KEY_REQUEST");
2390             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
2391             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
2392             if (hci_stack->bondable && !hci_stack->link_key_db) break;
2393             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
2394             hci_run();
2395             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
2396             return;
2397 
2398         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2399             reverse_bd_addr(&packet[2], addr);
2400             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2401             if (!conn) break;
2402             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
2403             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2404             // Change Connection Encryption keeps link key type
2405             if (link_key_type != CHANGED_COMBINATION_KEY){
2406                 conn->link_key_type = link_key_type;
2407             }
2408             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2409             // still forward event to allow dismiss of pairing dialog
2410             break;
2411         }
2412 
2413         case HCI_EVENT_PIN_CODE_REQUEST:
2414             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
2415             // non-bondable mode: pin code negative reply will be sent
2416             if (!hci_stack->bondable){
2417                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
2418                 hci_run();
2419                 return;
2420             }
2421             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
2422             if (!hci_stack->link_key_db) break;
2423             hci_event_pin_code_request_get_bd_addr(packet, addr);
2424             hci_stack->link_key_db->delete_link_key(addr);
2425             break;
2426 
2427         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2428             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
2429             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
2430             break;
2431 
2432         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
2433             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2434             if (!hci_stack->ssp_auto_accept) break;
2435             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
2436             break;
2437 
2438         case HCI_EVENT_USER_PASSKEY_REQUEST:
2439             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
2440             if (!hci_stack->ssp_auto_accept) break;
2441             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
2442             break;
2443         case HCI_EVENT_MODE_CHANGE:
2444             handle = hci_event_mode_change_get_handle(packet);
2445             conn = hci_connection_for_handle(handle);
2446             if (!conn) break;
2447             conn->connection_mode = hci_event_mode_change_get_mode(packet);
2448             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
2449             break;
2450 #endif
2451 
2452         case HCI_EVENT_ENCRYPTION_CHANGE:
2453             handle = hci_event_encryption_change_get_connection_handle(packet);
2454             conn = hci_connection_for_handle(handle);
2455             if (!conn) break;
2456             if (hci_event_encryption_change_get_status(packet) == 0) {
2457                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
2458                 if (encryption_enabled){
2459                     if (hci_is_le_connection(conn)){
2460                         // For LE, we accept connection as encrypted
2461                         conn->authentication_flags |= CONNECTION_ENCRYPTED;
2462                     }
2463 #ifdef ENABLE_CLASSIC
2464                     else {
2465                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
2466                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
2467                         bool connected_uses_aes_ccm = encryption_enabled == 2;
2468                         if (sc_used_during_pairing && !connected_uses_aes_ccm){
2469                             log_info("SC during pairing, but only E0 now -> abort");
2470                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2471                             break;
2472                         }
2473 
2474                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
2475                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
2476                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
2477                         } else {
2478                             // if not, pretend everything is perfect
2479                             hci_handle_read_encryption_key_size_complete(conn, 16);
2480                         }
2481                     }
2482 #endif
2483                 } else {
2484                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
2485                 }
2486             }
2487 
2488             break;
2489 
2490 #ifdef ENABLE_CLASSIC
2491         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
2492             handle = hci_event_authentication_complete_get_connection_handle(packet);
2493             conn = hci_connection_for_handle(handle);
2494             if (!conn) break;
2495 
2496             // ignore authentication event if we didn't request it
2497             if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) == 0) break;
2498 
2499             // dedicated bonding: send result and disconnect
2500             if (conn->bonding_flags & BONDING_DEDICATED){
2501                 conn->bonding_flags &= ~BONDING_DEDICATED;
2502                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
2503                 conn->bonding_status = packet[2];
2504                 break;
2505             }
2506 
2507             // authenticated only if auth status == 0
2508             if (hci_event_authentication_complete_get_status(packet) == 0){
2509                 // authenticated
2510                 conn->authentication_flags |= CONNECTION_AUTHENTICATED;
2511 
2512                 // If link key sufficient for requested security and not already encrypted, start encryption
2513                 if (((gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level)) &&
2514                     ((conn->authentication_flags & CONNECTION_ENCRYPTED) == 0)){
2515                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2516                     break;
2517                 }
2518             }
2519 
2520             // emit updated security level
2521             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
2522             break;
2523 #endif
2524 
2525         // HCI_EVENT_DISCONNECTION_COMPLETE
2526         // has been split, to first notify stack before shutting connection down
2527         // see end of function, too.
2528         case HCI_EVENT_DISCONNECTION_COMPLETE:
2529             if (packet[2]) break;   // status != 0
2530             handle = little_endian_read_16(packet, 3);
2531             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
2532             if (hci_stack->acl_fragmentation_total_size > 0) {
2533                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
2534                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0;
2535                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
2536                     hci_stack->acl_fragmentation_total_size = 0;
2537                     hci_stack->acl_fragmentation_pos = 0;
2538                     if (release_buffer){
2539                         hci_release_packet_buffer();
2540                     }
2541                 }
2542             }
2543 
2544             conn = hci_connection_for_handle(handle);
2545             if (!conn) break;
2546             // mark connection for shutdown
2547             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
2548 
2549             // emit dedicatd bonding event
2550             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
2551                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
2552             }
2553 
2554 #ifdef ENABLE_BLE
2555 #ifdef ENABLE_LE_PERIPHERAL
2556             // re-enable advertisements for le connections if active
2557             if (hci_is_le_connection(conn)){
2558                 hci_reenable_advertisements_if_needed();
2559             }
2560 #endif
2561 #endif
2562             break;
2563 
2564         case HCI_EVENT_HARDWARE_ERROR:
2565             log_error("Hardware Error: 0x%02x", packet[2]);
2566             if (hci_stack->hardware_error_callback){
2567                 (*hci_stack->hardware_error_callback)(packet[2]);
2568             } else {
2569                 // if no special requests, just reboot stack
2570                 hci_power_control_off();
2571                 hci_power_control_on();
2572             }
2573             break;
2574 
2575 #ifdef ENABLE_CLASSIC
2576         case HCI_EVENT_ROLE_CHANGE:
2577             if (packet[2]) break;   // status != 0
2578             reverse_bd_addr(&packet[3], addr);
2579             addr_type = BD_ADDR_TYPE_ACL;
2580             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2581             if (!conn) break;
2582             conn->role = packet[9];
2583             break;
2584 #endif
2585 
2586         case HCI_EVENT_TRANSPORT_PACKET_SENT:
2587             // release packet buffer only for asynchronous transport and if there are not further fragements
2588             if (hci_transport_synchronous()) {
2589                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
2590                 return; // instead of break: to avoid re-entering hci_run()
2591             }
2592             hci_stack->acl_fragmentation_tx_active = 0;
2593             if (hci_stack->acl_fragmentation_total_size) break;
2594             hci_release_packet_buffer();
2595 
2596             // L2CAP receives this event via the hci_emit_event below
2597 
2598 #ifdef ENABLE_CLASSIC
2599             // For SCO, we do the can_send_now_check here
2600             hci_notify_if_sco_can_send_now();
2601 #endif
2602             break;
2603 
2604 #ifdef ENABLE_CLASSIC
2605         case HCI_EVENT_SCO_CAN_SEND_NOW:
2606             // For SCO, we do the can_send_now_check here
2607             hci_stack->sco_can_send_now = 1;
2608             hci_notify_if_sco_can_send_now();
2609             return;
2610 
2611         // explode inquriy results for easier consumption
2612         case HCI_EVENT_INQUIRY_RESULT:
2613         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
2614         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
2615             gap_inquiry_explode(packet, size);
2616             break;
2617 #endif
2618 
2619 #ifdef ENABLE_BLE
2620         case HCI_EVENT_LE_META:
2621             switch (packet[2]){
2622 #ifdef ENABLE_LE_CENTRAL
2623                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
2624                     // log_info("advertising report received");
2625                     if (!hci_stack->le_scanning_enabled) break;
2626                     le_handle_advertisement_report(packet, size);
2627                     break;
2628 #endif
2629                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
2630                     // Connection management
2631                     reverse_bd_addr(&packet[8], addr);
2632                     addr_type = (bd_addr_type_t)packet[7];
2633                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2634                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2635 
2636 #ifdef ENABLE_LE_CENTRAL
2637                     // if auto-connect, remove from whitelist in both roles
2638                     if (hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST){
2639                         hci_remove_from_whitelist(addr_type, addr);
2640                     }
2641                     // handle error: error is reported only to the initiator -> outgoing connection
2642                     if (packet[3]){
2643 
2644                         // handle cancelled outgoing connection
2645                         // "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2646                         //  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2647                         //  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2648                         if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2649                             conn = gap_get_outgoing_connection();
2650                         }
2651 
2652                         // outgoing connection establishment is done
2653                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2654                         // remove entry
2655                         if (conn){
2656                             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2657                             btstack_memory_hci_connection_free( conn );
2658                         }
2659                         break;
2660                     }
2661 #endif
2662                     // on success, both hosts receive connection complete event
2663                     if (packet[6] == HCI_ROLE_MASTER){
2664 #ifdef ENABLE_LE_CENTRAL
2665                         // if we're master, it was an outgoing connection and we're done with it
2666                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2667 #endif
2668                     } else {
2669 #ifdef ENABLE_LE_PERIPHERAL
2670                         // if we're slave, it was an incoming connection, advertisements have stopped
2671                         hci_stack->le_advertisements_active = 0;
2672 #endif
2673                     }
2674                     // LE connections are auto-accepted, so just create a connection if there isn't one already
2675                     if (!conn){
2676                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2677                     }
2678                     // no memory, sorry.
2679                     if (!conn){
2680                         break;
2681                     }
2682 
2683                     conn->state = OPEN;
2684                     conn->role  = packet[6];
2685                     conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2686                     conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2687 
2688 #ifdef ENABLE_LE_PERIPHERAL
2689                     if (packet[6] == HCI_ROLE_SLAVE){
2690                         hci_reenable_advertisements_if_needed();
2691                     }
2692 #endif
2693 
2694                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2695 
2696                     // restart timer
2697                     // btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2698                     // btstack_run_loop_add_timer(&conn->timeout);
2699 
2700                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2701 
2702                     hci_emit_nr_connections_changed();
2703                     break;
2704 
2705                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
2706                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
2707                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
2708                     conn = hci_connection_for_handle(handle);
2709                     if (!conn) break;
2710                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
2711                     break;
2712 
2713                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
2714                     // connection
2715                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
2716                     conn = hci_connection_for_handle(handle);
2717                     if (conn) {
2718                         // read arguments
2719                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
2720                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
2721                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
2722                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
2723 
2724                         // validate against current connection parameter range
2725                         le_connection_parameter_range_t existing_range;
2726                         gap_get_connection_parameter_range(&existing_range);
2727                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
2728                         if (update_parameter){
2729                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
2730                             conn->le_conn_interval_min = le_conn_interval_min;
2731                             conn->le_conn_interval_max = le_conn_interval_max;
2732                             conn->le_conn_latency = le_conn_latency;
2733                             conn->le_supervision_timeout = le_supervision_timeout;
2734                         } else {
2735                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY;
2736                         }
2737                     }
2738                     break;
2739 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
2740                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
2741                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
2742                     conn = hci_connection_for_handle(handle);
2743                     if (conn) {
2744                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
2745                     }
2746                     break;
2747 #endif
2748                 default:
2749                     break;
2750             }
2751             break;
2752 #endif
2753         case HCI_EVENT_VENDOR_SPECIFIC:
2754             // Vendor specific commands often create vendor specific event instead of num completed packets
2755             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
2756             switch (hci_stack->manufacturer){
2757                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
2758                     hci_stack->num_cmd_packets = 1;
2759                     break;
2760                 default:
2761                     break;
2762             }
2763             break;
2764         default:
2765             break;
2766     }
2767 
2768     handle_event_for_current_stack_state(packet, size);
2769 
2770     // notify upper stack
2771 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
2772 
2773     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
2774     if (hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE){
2775         if (!packet[2]){
2776             handle = little_endian_read_16(packet, 3);
2777             hci_connection_t * aConn = hci_connection_for_handle(handle);
2778             if (aConn) {
2779                 // discard connection if app did not trigger a reconnect in the event handler
2780                 if (aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
2781                     hci_shutdown_connection(aConn);
2782                 }
2783             }
2784         }
2785     }
2786 
2787 	// execute main loop
2788 	hci_run();
2789 }
2790 
2791 #ifdef ENABLE_CLASSIC
2792 
2793 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
2794 static void sco_schedule_tx(hci_connection_t * conn);
2795 
2796 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
2797     log_debug("SCO TX Timeout");
2798     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
2799     hci_connection_t * conn = hci_connection_for_handle(con_handle);
2800     if (!conn) return;
2801 
2802     // trigger send
2803     conn->sco_tx_ready = 1;
2804     // extra packet if CVSD but SCO buffer is too short
2805     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
2806         conn->sco_tx_ready++;
2807     }
2808     hci_notify_if_sco_can_send_now();
2809 }
2810 
2811 
2812 #define SCO_TX_AFTER_RX_MS (6)
2813 
2814 static void sco_schedule_tx(hci_connection_t * conn){
2815 
2816     uint32_t now = btstack_run_loop_get_time_ms();
2817     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
2818     int time_delta_ms = sco_tx_ms - now;
2819 
2820     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
2821 
2822     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
2823     btstack_run_loop_set_timer(timer, time_delta_ms);
2824     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
2825     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
2826     btstack_run_loop_add_timer(timer);
2827 }
2828 
2829 static void sco_handler(uint8_t * packet, uint16_t size){
2830     // lookup connection struct
2831     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
2832     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
2833     if (!conn) return;
2834 
2835     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
2836     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
2837         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
2838             packet[2] = 0x3c;
2839             memmove(&packet[3], &packet[23], 63);
2840             size = 63;
2841         }
2842     }
2843 
2844     if (hci_have_usb_transport()){
2845         // Nothing to do
2846     } else {
2847         // 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);
2848         if (hci_stack->synchronous_flow_control_enabled == 0){
2849             uint32_t now = btstack_run_loop_get_time_ms();
2850 
2851             if (!conn->sco_rx_valid){
2852                 // ignore first 10 packets
2853                 conn->sco_rx_count++;
2854                 // log_debug("sco rx count %u", conn->sco_rx_count);
2855                 if (conn->sco_rx_count == 10) {
2856                     // use first timestamp as is and pretent it just started
2857                     conn->sco_rx_ms = now;
2858                     conn->sco_rx_valid = 1;
2859                     conn->sco_rx_count = 0;
2860                     sco_schedule_tx(conn);
2861                 }
2862             } else {
2863                 // track expected arrival timme
2864                 conn->sco_rx_count++;
2865                 conn->sco_rx_ms += 7;
2866                 int delta = (int32_t) (now - conn->sco_rx_ms);
2867                 if (delta > 0){
2868                     conn->sco_rx_ms++;
2869                 }
2870                 // log_debug("sco rx %u", conn->sco_rx_ms);
2871                 sco_schedule_tx(conn);
2872             }
2873         }
2874     }
2875     // deliver to app
2876     if (hci_stack->sco_packet_handler) {
2877         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
2878     }
2879 
2880 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
2881     conn->num_packets_completed++;
2882     hci_stack->host_completed_packets = 1;
2883     hci_run();
2884 #endif
2885 }
2886 #endif
2887 
2888 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
2889     hci_dump_packet(packet_type, 1, packet, size);
2890     switch (packet_type) {
2891         case HCI_EVENT_PACKET:
2892             event_handler(packet, size);
2893             break;
2894         case HCI_ACL_DATA_PACKET:
2895             acl_handler(packet, size);
2896             break;
2897 #ifdef ENABLE_CLASSIC
2898         case HCI_SCO_DATA_PACKET:
2899             sco_handler(packet, size);
2900             break;
2901 #endif
2902         default:
2903             break;
2904     }
2905 }
2906 
2907 /**
2908  * @brief Add event packet handler.
2909  */
2910 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
2911     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
2912 }
2913 
2914 
2915 /** Register HCI packet handlers */
2916 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
2917     hci_stack->acl_packet_handler = handler;
2918 }
2919 
2920 #ifdef ENABLE_CLASSIC
2921 /**
2922  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
2923  */
2924 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
2925     hci_stack->sco_packet_handler = handler;
2926 }
2927 #endif
2928 
2929 static void hci_state_reset(void){
2930     // no connections yet
2931     hci_stack->connections = NULL;
2932 
2933     // keep discoverable/connectable as this has been requested by the client(s)
2934     // hci_stack->discoverable = 0;
2935     // hci_stack->connectable = 0;
2936     // hci_stack->bondable = 1;
2937     // hci_stack->own_addr_type = 0;
2938 
2939     // buffer is free
2940     hci_stack->hci_packet_buffer_reserved = 0;
2941 
2942     // no pending cmds
2943     hci_stack->decline_reason = 0;
2944     hci_stack->new_scan_enable_value = 0xff;
2945 
2946     // LE
2947 #ifdef ENABLE_BLE
2948     memset(hci_stack->le_random_address, 0, 6);
2949     hci_stack->le_random_address_set = 0;
2950 #endif
2951 #ifdef ENABLE_LE_CENTRAL
2952     hci_stack->le_scanning_active  = 0;
2953     hci_stack->le_scan_type = 0xff;
2954     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2955     hci_stack->le_whitelist = 0;
2956     hci_stack->le_whitelist_capacity = 0;
2957 #endif
2958 }
2959 
2960 #ifdef ENABLE_CLASSIC
2961 /**
2962  * @brief Configure Bluetooth hardware control. Has to be called before power on.
2963  */
2964 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
2965     // store and open remote device db
2966     hci_stack->link_key_db = link_key_db;
2967     if (hci_stack->link_key_db) {
2968         hci_stack->link_key_db->open();
2969     }
2970 }
2971 #endif
2972 
2973 void hci_init(const hci_transport_t *transport, const void *config){
2974 
2975 #ifdef HAVE_MALLOC
2976     if (!hci_stack) {
2977         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
2978     }
2979 #else
2980     hci_stack = &hci_stack_static;
2981 #endif
2982     memset(hci_stack, 0, sizeof(hci_stack_t));
2983 
2984     // reference to use transport layer implementation
2985     hci_stack->hci_transport = transport;
2986 
2987     // reference to used config
2988     hci_stack->config = config;
2989 
2990     // setup pointer for outgoing packet buffer
2991     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
2992 
2993     // max acl payload size defined in config.h
2994     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
2995 
2996     // register packet handlers with transport
2997     transport->register_packet_handler(&packet_handler);
2998 
2999     hci_stack->state = HCI_STATE_OFF;
3000 
3001     // class of device
3002     hci_stack->class_of_device = 0x007a020c; // Smartphone
3003 
3004     // bondable by default
3005     hci_stack->bondable = 1;
3006 
3007 #ifdef ENABLE_CLASSIC
3008     // classic name
3009     hci_stack->local_name = default_classic_name;
3010 
3011     // Master slave policy
3012     hci_stack->master_slave_policy = 1;
3013 
3014     // Allow Role Switch
3015     hci_stack->allow_role_switch = 1;
3016 
3017     // Default / minimum security level = 2
3018     hci_stack->gap_security_level = LEVEL_2;
3019 
3020     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3, we use 16 as default
3021     hci_stack->gap_required_encyrption_key_size = 16;
3022 #endif
3023 
3024     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3025     hci_stack->ssp_enable = 1;
3026     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3027     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3028     hci_stack->ssp_auto_accept = 1;
3029 
3030     // Secure Connections: enable (requires support from Controller)
3031     hci_stack->secure_connections_enable = true;
3032 
3033     // voice setting - signed 16 bit pcm data with CVSD over the air
3034     hci_stack->sco_voice_setting = 0x60;
3035 
3036 #ifdef ENABLE_LE_CENTRAL
3037     // connection parameter to use for outgoing connections
3038     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3039     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3040     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3041     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3042     hci_stack->le_connection_latency      = 4;         // 4
3043     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3044     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3045     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3046 
3047     // default LE Scanning
3048     hci_stack->le_scan_interval = 0x1e0;
3049     hci_stack->le_scan_window   =  0x30;
3050 #endif
3051 
3052 #ifdef ENABLE_LE_PERIPHERAL
3053     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3054 #endif
3055 
3056     // connection parameter range used to answer connection parameter update requests in l2cap
3057     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3058     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3059     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3060     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3061     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3062     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3063 
3064     hci_state_reset();
3065 }
3066 
3067 /**
3068  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3069  */
3070 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3071     hci_stack->chipset = chipset_driver;
3072 
3073     // reset chipset driver - init is also called on power_up
3074     if (hci_stack->chipset && hci_stack->chipset->init){
3075         hci_stack->chipset->init(hci_stack->config);
3076     }
3077 }
3078 
3079 /**
3080  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3081  */
3082 void hci_set_control(const btstack_control_t *hardware_control){
3083     // references to used control implementation
3084     hci_stack->control = hardware_control;
3085     // init with transport config
3086     hardware_control->init(hci_stack->config);
3087 }
3088 
3089 void hci_close(void){
3090     // close remote device db
3091     if (hci_stack->link_key_db) {
3092         hci_stack->link_key_db->close();
3093     }
3094 
3095     btstack_linked_list_iterator_t lit;
3096     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3097     while (btstack_linked_list_iterator_has_next(&lit)){
3098         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3099         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3100         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3101         hci_shutdown_connection(connection);
3102     }
3103 
3104     hci_power_control(HCI_POWER_OFF);
3105 
3106 #ifdef HAVE_MALLOC
3107     free(hci_stack);
3108 #endif
3109     hci_stack = NULL;
3110 }
3111 
3112 #ifdef ENABLE_CLASSIC
3113 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3114     // validate ranage and set
3115     if (encryption_key_size < 7)  return;
3116     if (encryption_key_size > 16) return;
3117     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3118 }
3119 
3120 void gap_set_security_level(gap_security_level_t security_level){
3121     hci_stack->gap_security_level = security_level;
3122 }
3123 
3124 gap_security_level_t gap_get_security_level(void){
3125     return hci_stack->gap_security_level;
3126 }
3127 #endif
3128 
3129 #ifdef ENABLE_CLASSIC
3130 void gap_set_class_of_device(uint32_t class_of_device){
3131     hci_stack->class_of_device = class_of_device;
3132 }
3133 
3134 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3135     hci_stack->default_link_policy_settings = default_link_policy_settings;
3136 }
3137 
3138 void gap_set_allow_role_switch(bool allow_role_switch){
3139     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3140 }
3141 
3142 uint8_t hci_get_allow_role_switch(void){
3143     return  hci_stack->allow_role_switch;
3144 }
3145 
3146 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3147     hci_stack->link_supervision_timeout = link_supervision_timeout;
3148 }
3149 
3150 void hci_disable_l2cap_timeout_check(void){
3151     disable_l2cap_timeouts = 1;
3152 }
3153 #endif
3154 
3155 #if !defined(HAVE_PLATFORM_IPHONE_OS) && !defined (HAVE_HOST_CONTROLLER_API)
3156 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3157 void hci_set_bd_addr(bd_addr_t addr){
3158     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3159     hci_stack->custom_bd_addr_set = 1;
3160 }
3161 #endif
3162 
3163 // State-Module-Driver overview
3164 // state                    module  low-level
3165 // HCI_STATE_OFF             off      close
3166 // HCI_STATE_INITIALIZING,   on       open
3167 // HCI_STATE_WORKING,        on       open
3168 // HCI_STATE_HALTING,        on       open
3169 // HCI_STATE_SLEEPING,    off/sleep   close
3170 // HCI_STATE_FALLING_ASLEEP  on       open
3171 
3172 static int hci_power_control_on(void){
3173 
3174     // power on
3175     int err = 0;
3176     if (hci_stack->control && hci_stack->control->on){
3177         err = (*hci_stack->control->on)();
3178     }
3179     if (err){
3180         log_error( "POWER_ON failed");
3181         hci_emit_hci_open_failed();
3182         return err;
3183     }
3184 
3185     // int chipset driver
3186     if (hci_stack->chipset && hci_stack->chipset->init){
3187         hci_stack->chipset->init(hci_stack->config);
3188     }
3189 
3190     // init transport
3191     if (hci_stack->hci_transport->init){
3192         hci_stack->hci_transport->init(hci_stack->config);
3193     }
3194 
3195     // open transport
3196     err = hci_stack->hci_transport->open();
3197     if (err){
3198         log_error( "HCI_INIT failed, turning Bluetooth off again");
3199         if (hci_stack->control && hci_stack->control->off){
3200             (*hci_stack->control->off)();
3201         }
3202         hci_emit_hci_open_failed();
3203         return err;
3204     }
3205     return 0;
3206 }
3207 
3208 static void hci_power_control_off(void){
3209 
3210     log_info("hci_power_control_off");
3211 
3212     // close low-level device
3213     hci_stack->hci_transport->close();
3214 
3215     log_info("hci_power_control_off - hci_transport closed");
3216 
3217     // power off
3218     if (hci_stack->control && hci_stack->control->off){
3219         (*hci_stack->control->off)();
3220     }
3221 
3222     log_info("hci_power_control_off - control closed");
3223 
3224     hci_stack->state = HCI_STATE_OFF;
3225 }
3226 
3227 static void hci_power_control_sleep(void){
3228 
3229     log_info("hci_power_control_sleep");
3230 
3231 #if 0
3232     // don't close serial port during sleep
3233 
3234     // close low-level device
3235     hci_stack->hci_transport->close(hci_stack->config);
3236 #endif
3237 
3238     // sleep mode
3239     if (hci_stack->control && hci_stack->control->sleep){
3240         (*hci_stack->control->sleep)();
3241     }
3242 
3243     hci_stack->state = HCI_STATE_SLEEPING;
3244 }
3245 
3246 static int hci_power_control_wake(void){
3247 
3248     log_info("hci_power_control_wake");
3249 
3250     // wake on
3251     if (hci_stack->control && hci_stack->control->wake){
3252         (*hci_stack->control->wake)();
3253     }
3254 
3255 #if 0
3256     // open low-level device
3257     int err = hci_stack->hci_transport->open(hci_stack->config);
3258     if (err){
3259         log_error( "HCI_INIT failed, turning Bluetooth off again");
3260         if (hci_stack->control && hci_stack->control->off){
3261             (*hci_stack->control->off)();
3262         }
3263         hci_emit_hci_open_failed();
3264         return err;
3265     }
3266 #endif
3267 
3268     return 0;
3269 }
3270 
3271 static void hci_power_transition_to_initializing(void){
3272     // set up state machine
3273     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3274     hci_stack->hci_packet_buffer_reserved = 0;
3275     hci_stack->state = HCI_STATE_INITIALIZING;
3276     hci_stack->substate = HCI_INIT_SEND_RESET;
3277 }
3278 
3279 int hci_power_control(HCI_POWER_MODE power_mode){
3280 
3281     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
3282 
3283     int err = 0;
3284     switch (hci_stack->state){
3285 
3286         case HCI_STATE_OFF:
3287             switch (power_mode){
3288                 case HCI_POWER_ON:
3289                     err = hci_power_control_on();
3290                     if (err) {
3291                         log_error("hci_power_control_on() error %d", err);
3292                         return err;
3293                     }
3294                     hci_power_transition_to_initializing();
3295                     break;
3296                 case HCI_POWER_OFF:
3297                     // do nothing
3298                     break;
3299                 case HCI_POWER_SLEEP:
3300                     // do nothing (with SLEEP == OFF)
3301                     break;
3302             }
3303             break;
3304 
3305         case HCI_STATE_INITIALIZING:
3306             switch (power_mode){
3307                 case HCI_POWER_ON:
3308                     // do nothing
3309                     break;
3310                 case HCI_POWER_OFF:
3311                     // no connections yet, just turn it off
3312                     hci_power_control_off();
3313                     break;
3314                 case HCI_POWER_SLEEP:
3315                     // no connections yet, just turn it off
3316                     hci_power_control_sleep();
3317                     break;
3318             }
3319             break;
3320 
3321         case HCI_STATE_WORKING:
3322             switch (power_mode){
3323                 case HCI_POWER_ON:
3324                     // do nothing
3325                     break;
3326                 case HCI_POWER_OFF:
3327                     // see hci_run
3328                     hci_stack->state = HCI_STATE_HALTING;
3329                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3330                     break;
3331                 case HCI_POWER_SLEEP:
3332                     // see hci_run
3333                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3334                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3335                     break;
3336             }
3337             break;
3338 
3339         case HCI_STATE_HALTING:
3340             switch (power_mode){
3341                 case HCI_POWER_ON:
3342                     hci_power_transition_to_initializing();
3343                     break;
3344                 case HCI_POWER_OFF:
3345                     // do nothing
3346                     break;
3347                 case HCI_POWER_SLEEP:
3348                     // see hci_run
3349                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3350                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3351                     break;
3352             }
3353             break;
3354 
3355         case HCI_STATE_FALLING_ASLEEP:
3356             switch (power_mode){
3357                 case HCI_POWER_ON:
3358 
3359 #ifdef HAVE_PLATFORM_IPHONE_OS
3360                     // nothing to do, if H4 supports power management
3361                     if (btstack_control_iphone_power_management_enabled()){
3362                         hci_stack->state = HCI_STATE_INITIALIZING;
3363                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
3364                         break;
3365                     }
3366 #endif
3367                     hci_power_transition_to_initializing();
3368                     break;
3369                 case HCI_POWER_OFF:
3370                     // see hci_run
3371                     hci_stack->state = HCI_STATE_HALTING;
3372                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3373                     break;
3374                 case HCI_POWER_SLEEP:
3375                     // do nothing
3376                     break;
3377             }
3378             break;
3379 
3380         case HCI_STATE_SLEEPING:
3381             switch (power_mode){
3382                 case HCI_POWER_ON:
3383 
3384 #ifdef HAVE_PLATFORM_IPHONE_OS
3385                     // nothing to do, if H4 supports power management
3386                     if (btstack_control_iphone_power_management_enabled()){
3387                         hci_stack->state = HCI_STATE_INITIALIZING;
3388                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
3389                         hci_update_scan_enable();
3390                         break;
3391                     }
3392 #endif
3393                     err = hci_power_control_wake();
3394                     if (err) return err;
3395                     hci_power_transition_to_initializing();
3396                     break;
3397                 case HCI_POWER_OFF:
3398                     hci_stack->state = HCI_STATE_HALTING;
3399                     hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3400                     break;
3401                 case HCI_POWER_SLEEP:
3402                     // do nothing
3403                     break;
3404             }
3405             break;
3406     }
3407 
3408     // create internal event
3409 	hci_emit_state();
3410 
3411 	// trigger next/first action
3412 	hci_run();
3413 
3414     return 0;
3415 }
3416 
3417 
3418 #ifdef ENABLE_CLASSIC
3419 
3420 static void hci_update_scan_enable(void){
3421     // 2 = page scan, 1 = inq scan
3422     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
3423     hci_run();
3424 }
3425 
3426 void gap_discoverable_control(uint8_t enable){
3427     if (enable) enable = 1; // normalize argument
3428 
3429     if (hci_stack->discoverable == enable){
3430         hci_emit_discoverable_enabled(hci_stack->discoverable);
3431         return;
3432     }
3433 
3434     hci_stack->discoverable = enable;
3435     hci_update_scan_enable();
3436 }
3437 
3438 void gap_connectable_control(uint8_t enable){
3439     if (enable) enable = 1; // normalize argument
3440 
3441     // don't emit event
3442     if (hci_stack->connectable == enable) return;
3443 
3444     hci_stack->connectable = enable;
3445     hci_update_scan_enable();
3446 }
3447 #endif
3448 
3449 void gap_local_bd_addr(bd_addr_t address_buffer){
3450     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
3451 }
3452 
3453 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3454 static void hci_host_num_completed_packets(void){
3455 
3456     // create packet manually as arrays are not supported and num_commands should not get reduced
3457     hci_reserve_packet_buffer();
3458     uint8_t * packet = hci_get_outgoing_packet_buffer();
3459 
3460     uint16_t size = 0;
3461     uint16_t num_handles = 0;
3462     packet[size++] = 0x35;
3463     packet[size++] = 0x0c;
3464     size++;  // skip param len
3465     size++;  // skip num handles
3466 
3467     // add { handle, packets } entries
3468     btstack_linked_item_t * it;
3469     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3470         hci_connection_t * connection = (hci_connection_t *) it;
3471         if (connection->num_packets_completed){
3472             little_endian_store_16(packet, size, connection->con_handle);
3473             size += 2;
3474             little_endian_store_16(packet, size, connection->num_packets_completed);
3475             size += 2;
3476             //
3477             num_handles++;
3478             connection->num_packets_completed = 0;
3479         }
3480     }
3481 
3482     packet[2] = size - 3;
3483     packet[3] = num_handles;
3484 
3485     hci_stack->host_completed_packets = 0;
3486 
3487     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
3488     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
3489 
3490     // release packet buffer for synchronous transport implementations
3491     if (hci_transport_synchronous()){
3492         hci_release_packet_buffer();
3493         hci_emit_transport_packet_sent();
3494     }
3495 }
3496 #endif
3497 
3498 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
3499     UNUSED(ds);
3500     hci_stack->substate = HCI_HALTING_CLOSE;
3501     // allow packet handlers to defer final shutdown
3502     hci_emit_state();
3503     hci_run();
3504 }
3505 
3506 static bool hci_run_acl_fragments(void){
3507     if (hci_stack->acl_fragmentation_total_size > 0) {
3508         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
3509         hci_connection_t *connection = hci_connection_for_handle(con_handle);
3510         if (connection) {
3511             if (hci_can_send_prepared_acl_packet_now(con_handle)){
3512                 hci_send_acl_packet_fragments(connection);
3513                 return true;
3514             }
3515         } else {
3516             // connection gone -> discard further fragments
3517             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
3518             hci_stack->acl_fragmentation_total_size = 0;
3519             hci_stack->acl_fragmentation_pos = 0;
3520         }
3521     }
3522     return false;
3523 }
3524 
3525 #ifdef ENABLE_CLASSIC
3526 static bool hci_run_general_gap_classic(void){
3527 
3528     // decline incoming connections
3529     if (hci_stack->decline_reason){
3530         uint8_t reason = hci_stack->decline_reason;
3531         hci_stack->decline_reason = 0;
3532         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
3533         return true;
3534     }
3535     // send scan enable
3536     if ((hci_stack->state == HCI_STATE_WORKING) && (hci_stack->new_scan_enable_value != 0xff) && hci_classic_supported()){
3537         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
3538         hci_stack->new_scan_enable_value = 0xff;
3539         return true;
3540     }
3541     // start/stop inquiry
3542     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
3543         uint8_t duration = hci_stack->inquiry_state;
3544         hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
3545         hci_send_cmd(&hci_inquiry, GAP_IAC_GENERAL_INQUIRY, duration, 0);
3546         return true;
3547     }
3548     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
3549         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
3550         hci_send_cmd(&hci_inquiry_cancel);
3551         return true;
3552     }
3553     // remote name request
3554     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
3555         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
3556         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
3557                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
3558         return true;
3559     }
3560     // pairing
3561     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
3562         uint8_t state = hci_stack->gap_pairing_state;
3563         hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
3564         switch (state){
3565             case GAP_PAIRING_STATE_SEND_PIN:
3566                 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);
3567                 break;
3568             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
3569                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
3570                 break;
3571             case GAP_PAIRING_STATE_SEND_PASSKEY:
3572                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
3573                 break;
3574             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
3575                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
3576                 break;
3577             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
3578                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
3579                 break;
3580             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
3581                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
3582                 break;
3583             default:
3584                 break;
3585         }
3586         return true;
3587     }
3588     return false;
3589 }
3590 #endif
3591 
3592 #ifdef ENABLE_BLE
3593 static bool hci_run_general_gap_le(void){
3594 
3595     // advertisements, active scanning, and creating connections requires random address to be set if using private address
3596 
3597     if (hci_stack->state != HCI_STATE_WORKING) return false;
3598     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0) ) return false;
3599 
3600 #ifdef ENABLE_LE_CENTRAL
3601     // parameter change requires scanning to be stopped first
3602     if (hci_stack->le_scan_type != 0xff) {
3603         if (hci_stack->le_scanning_active){
3604             hci_stack->le_scanning_active = 0;
3605             hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
3606         } else {
3607             int scan_type = (int) hci_stack->le_scan_type;
3608             hci_stack->le_scan_type = 0xff;
3609             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);
3610         }
3611         return true;
3612     }
3613     // finally, we can enable/disable le scan
3614     if ((hci_stack->le_scanning_enabled != hci_stack->le_scanning_active)){
3615         hci_stack->le_scanning_active = hci_stack->le_scanning_enabled;
3616         hci_send_cmd(&hci_le_set_scan_enable, hci_stack->le_scanning_enabled, 0);
3617         return true;
3618     }
3619 #endif
3620 #ifdef ENABLE_LE_PERIPHERAL
3621     // le advertisement control
3622     if (hci_stack->le_advertisements_todo){
3623         log_info("hci_run: gap_le: adv todo: %x", hci_stack->le_advertisements_todo );
3624     }
3625     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_DISABLE){
3626         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_DISABLE;
3627         hci_send_cmd(&hci_le_set_advertise_enable, 0);
3628         return true;
3629     }
3630     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
3631         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3632         hci_send_cmd(&hci_le_set_advertising_parameters,
3633                      hci_stack->le_advertisements_interval_min,
3634                      hci_stack->le_advertisements_interval_max,
3635                      hci_stack->le_advertisements_type,
3636                      hci_stack->le_own_addr_type,
3637                      hci_stack->le_advertisements_direct_address_type,
3638                      hci_stack->le_advertisements_direct_address,
3639                      hci_stack->le_advertisements_channel_map,
3640                      hci_stack->le_advertisements_filter_policy);
3641         return true;
3642     }
3643     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
3644         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3645         uint8_t adv_data_clean[31];
3646         memset(adv_data_clean, 0, sizeof(adv_data_clean));
3647         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
3648                      hci_stack->le_advertisements_data_len);
3649         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
3650         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
3651         return true;
3652     }
3653     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
3654         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
3655         uint8_t scan_data_clean[31];
3656         memset(scan_data_clean, 0, sizeof(scan_data_clean));
3657         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
3658                      hci_stack->le_scan_response_data_len);
3659         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
3660         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
3661         return true;
3662     }
3663     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_ENABLE){
3664         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_ENABLE;
3665         hci_send_cmd(&hci_le_set_advertise_enable, 1);
3666         return true;
3667     }
3668 #endif
3669 
3670 #ifdef ENABLE_LE_CENTRAL
3671     //
3672     // LE Whitelist Management
3673     //
3674 
3675     // check if whitelist needs modification
3676     btstack_linked_list_iterator_t lit;
3677     int modification_pending = 0;
3678     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3679     while (btstack_linked_list_iterator_has_next(&lit)){
3680         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3681         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
3682             modification_pending = 1;
3683             break;
3684         }
3685     }
3686 
3687     if (modification_pending){
3688         // stop connnecting if modification pending
3689         if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
3690             hci_send_cmd(&hci_le_create_connection_cancel);
3691             return true;
3692         }
3693 
3694         // add/remove entries
3695         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
3696         while (btstack_linked_list_iterator_has_next(&lit)){
3697             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
3698             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
3699                 entry->state = LE_WHITELIST_ON_CONTROLLER;
3700                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
3701                 return true;
3702             }
3703             if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
3704                 bd_addr_t address;
3705                 bd_addr_type_t address_type = entry->address_type;
3706                 (void)memcpy(address, entry->address, 6);
3707                 btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
3708                 btstack_memory_whitelist_entry_free(entry);
3709                 hci_send_cmd(&hci_le_remove_device_from_white_list, address_type, address);
3710                 return true;
3711             }
3712         }
3713     }
3714 
3715     // start connecting
3716     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) &&
3717          !btstack_linked_list_empty(&hci_stack->le_whitelist)){
3718         bd_addr_t null_addr;
3719         memset(null_addr, 0, 6);
3720         hci_send_cmd(&hci_le_create_connection,
3721                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
3722                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
3723                      1,         // use whitelist
3724                      0,         // peer address type
3725                      null_addr, // peer bd addr
3726                      hci_stack->le_own_addr_type, // our addr type:
3727                      hci_stack->le_connection_interval_min,    // conn interval min
3728                      hci_stack->le_connection_interval_max,    // conn interval max
3729                      hci_stack->le_connection_latency,         // conn latency
3730                      hci_stack->le_supervision_timeout,        // conn latency
3731                      hci_stack->le_minimum_ce_length,          // min ce length
3732                      hci_stack->le_maximum_ce_length           // max ce length
3733         );
3734         return true;
3735     }
3736 #endif
3737     return false;
3738 }
3739 #endif
3740 
3741 static bool hci_run_general_pending_commmands(void){
3742     btstack_linked_item_t * it;
3743     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
3744         hci_connection_t * connection = (hci_connection_t *) it;
3745 
3746         switch(connection->state){
3747             case SEND_CREATE_CONNECTION:
3748                 switch(connection->address_type){
3749 #ifdef ENABLE_CLASSIC
3750                     case BD_ADDR_TYPE_ACL:
3751                         log_info("sending hci_create_connection");
3752                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
3753                         break;
3754 #endif
3755                     default:
3756 #ifdef ENABLE_BLE
3757 #ifdef ENABLE_LE_CENTRAL
3758                         // track outgoing connection
3759                         hci_stack->outgoing_addr_type = connection->address_type;
3760                         (void)memcpy(hci_stack->outgoing_addr,
3761                                      connection->address, 6);
3762                         log_info("sending hci_le_create_connection");
3763                         hci_send_cmd(&hci_le_create_connection,
3764                                      hci_stack->le_connection_scan_interval,    // conn scan interval
3765                                      hci_stack->le_connection_scan_window,      // conn scan windows
3766                                      0,         // don't use whitelist
3767                                      connection->address_type, // peer address type
3768                                      connection->address,      // peer bd addr
3769                                      hci_stack->le_own_addr_type, // our addr type:
3770                                      hci_stack->le_connection_interval_min,    // conn interval min
3771                                      hci_stack->le_connection_interval_max,    // conn interval max
3772                                      hci_stack->le_connection_latency,         // conn latency
3773                                      hci_stack->le_supervision_timeout,        // conn latency
3774                                      hci_stack->le_minimum_ce_length,          // min ce length
3775                                      hci_stack->le_maximum_ce_length          // max ce length
3776                         );
3777                         connection->state = SENT_CREATE_CONNECTION;
3778 #endif
3779 #endif
3780                         break;
3781                 }
3782                 return true;
3783 
3784 #ifdef ENABLE_CLASSIC
3785             case RECEIVED_CONNECTION_REQUEST:
3786                 connection->role  = HCI_ROLE_SLAVE;
3787                 if (connection->address_type == BD_ADDR_TYPE_ACL){
3788                     log_info("sending hci_accept_connection_request");
3789                     connection->state = ACCEPTED_CONNECTION_REQUEST;
3790                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
3791                 }
3792                 return true;
3793 #endif
3794 
3795 #ifdef ENABLE_BLE
3796 #ifdef ENABLE_LE_CENTRAL
3797             case SEND_CANCEL_CONNECTION:
3798                 connection->state = SENT_CANCEL_CONNECTION;
3799                 hci_send_cmd(&hci_le_create_connection_cancel);
3800                 return true;
3801 #endif
3802 #endif
3803             case SEND_DISCONNECT:
3804                 connection->state = SENT_DISCONNECT;
3805                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3806                 return true;
3807 
3808             default:
3809                 break;
3810         }
3811 
3812         // no further commands if connection is about to get shut down
3813         if (connection->state == SENT_DISCONNECT) continue;
3814 
3815         if (connection->authentication_flags & READ_RSSI){
3816             connectionClearAuthenticationFlags(connection, READ_RSSI);
3817             hci_send_cmd(&hci_read_rssi, connection->con_handle);
3818             return true;
3819         }
3820 
3821 #ifdef ENABLE_CLASSIC
3822 
3823         if (connection->authentication_flags & WRITE_SUPERVISION_TIMEOUT){
3824             connectionClearAuthenticationFlags(connection, WRITE_SUPERVISION_TIMEOUT);
3825             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
3826             return true;
3827         }
3828 
3829         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
3830             log_info("responding to link key request");
3831             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
3832 
3833             link_key_t link_key;
3834             link_key_type_t link_key_type;
3835             bool have_link_key = hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type);
3836 
3837             const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
3838             bool sc_enabled_remote = (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
3839             bool sc_downgrade = have_link_key && (gap_secure_connection_for_link_key_type(link_key_type) == 1) && !sc_enabled_remote;
3840             if (sc_downgrade){
3841                 log_info("Link key based on SC, but remote does not support SC -> disconnect");
3842                 connection->state = SENT_DISCONNECT;
3843                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
3844                 return true;
3845             }
3846 
3847             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level);
3848             if (have_link_key && security_level_sufficient){
3849                 connection->link_key_type = link_key_type;
3850                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
3851             } else {
3852                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
3853             }
3854             return true;
3855         }
3856 
3857         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
3858             log_info("denying to pin request");
3859             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
3860             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
3861             return true;
3862         }
3863 
3864         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
3865             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
3866             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
3867             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
3868                 // tweak authentication requirements
3869                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
3870                 if (connection->bonding_flags & BONDING_DEDICATED){
3871                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
3872                 }
3873                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
3874                     authreq |= 1;
3875                 }
3876                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
3877             } else {
3878                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
3879             }
3880             return true;
3881         }
3882 
3883         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
3884             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
3885             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
3886             return true;
3887         }
3888 
3889         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
3890             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
3891             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
3892             return true;
3893         }
3894 
3895         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
3896             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
3897             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
3898             return true;
3899         }
3900 
3901         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
3902             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
3903             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
3904             return true;
3905         }
3906 
3907         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
3908             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
3909             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
3910             return true;
3911         }
3912 
3913         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
3914             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
3915             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
3916             connection->state = SENT_DISCONNECT;
3917             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3918             return true;
3919         }
3920 
3921         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
3922             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
3923             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
3924             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
3925             return true;
3926         }
3927 
3928         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
3929             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
3930             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
3931             return true;
3932         }
3933         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
3934             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3935             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
3936             return true;
3937         }
3938 #endif
3939 
3940         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
3941             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
3942             if (connection->state != SENT_DISCONNECT){
3943                 connection->state = SENT_DISCONNECT;
3944                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
3945                 return true;
3946             }
3947         }
3948 
3949 #ifdef ENABLE_CLASSIC
3950         uint16_t sniff_min_interval;
3951         switch (connection->sniff_min_interval){
3952             case 0:
3953                 break;
3954             case 0xffff:
3955                 connection->sniff_min_interval = 0;
3956                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
3957                 return true;
3958             default:
3959                 sniff_min_interval = connection->sniff_min_interval;
3960                 connection->sniff_min_interval = 0;
3961                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
3962                 return true;
3963         }
3964 #endif
3965 
3966 #ifdef ENABLE_BLE
3967         switch (connection->le_con_parameter_update_state){
3968             // response to L2CAP CON PARAMETER UPDATE REQUEST
3969             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
3970                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
3971                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
3972                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
3973                              0x0000, 0xffff);
3974                 return true;
3975             case CON_PARAMETER_UPDATE_REPLY:
3976                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
3977                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
3978                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
3979                              0x0000, 0xffff);
3980                 return true;
3981             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
3982                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
3983                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
3984                 return true;
3985             default:
3986                 break;
3987         }
3988         if (connection->le_phy_update_all_phys != 0xff){
3989             uint8_t all_phys = connection->le_phy_update_all_phys;
3990             connection->le_phy_update_all_phys = 0xff;
3991             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);
3992             return true;
3993         }
3994 #endif
3995     }
3996     return false;
3997 }
3998 
3999 static void hci_run(void){
4000 
4001     bool done;
4002 
4003     // send continuation fragments first, as they block the prepared packet buffer
4004     done = hci_run_acl_fragments();
4005     if (done) return;
4006 
4007 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4008     // send host num completed packets next as they don't require num_cmd_packets > 0
4009     if (!hci_can_send_comand_packet_transport()) return;
4010     if (hci_stack->host_completed_packets){
4011         hci_host_num_completed_packets();
4012         return;
4013     }
4014 #endif
4015 
4016     if (!hci_can_send_command_packet_now()) return;
4017 
4018     // global/non-connection oriented commands
4019 
4020 
4021 #ifdef ENABLE_CLASSIC
4022     // general gap classic
4023     done = hci_run_general_gap_classic();
4024     if (done) return;
4025 #endif
4026 
4027 #ifdef ENABLE_BLE
4028     // general gap le
4029     done = hci_run_general_gap_le();
4030     if (done) return;
4031 #endif
4032 
4033     // send pending HCI commands
4034     done = hci_run_general_pending_commmands();
4035     if (done) return;
4036 
4037     // stack state sub statemachines
4038     hci_connection_t * connection;
4039     switch (hci_stack->state){
4040         case HCI_STATE_INITIALIZING:
4041             hci_initializing_run();
4042             break;
4043 
4044         case HCI_STATE_HALTING:
4045 
4046             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
4047             switch (hci_stack->substate){
4048                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
4049                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
4050 
4051 #ifdef ENABLE_BLE
4052 #ifdef ENABLE_LE_CENTRAL
4053                     // free whitelist entries
4054                     {
4055                         btstack_linked_list_iterator_t lit;
4056                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4057                         while (btstack_linked_list_iterator_has_next(&lit)){
4058                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4059                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4060                             btstack_memory_whitelist_entry_free(entry);
4061                         }
4062                     }
4063 #endif
4064 #endif
4065                     // close all open connections
4066                     connection =  (hci_connection_t *) hci_stack->connections;
4067                     if (connection){
4068                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
4069                         if (!hci_can_send_command_packet_now()) return;
4070 
4071                         // check state
4072                         if (connection->state == SENT_DISCONNECT) return;
4073                         connection->state = SENT_DISCONNECT;
4074 
4075                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
4076 
4077                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
4078                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
4079 
4080                         // ... which would be ignored anyway as we shutdown (free) the connection now
4081                         hci_shutdown_connection(connection);
4082 
4083                         // finally, send the disconnect command
4084                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4085                         return;
4086                     }
4087 
4088                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
4089                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
4090                         log_info("HCI_STATE_HALTING: wait 50 ms");
4091                         hci_stack->substate = HCI_HALTING_W4_TIMER;
4092                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
4093                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
4094                         btstack_run_loop_add_timer(&hci_stack->timeout);
4095                         break;
4096                     }
4097 
4098                     /* fall through */
4099 
4100                 case HCI_HALTING_CLOSE:
4101                     log_info("HCI_STATE_HALTING, calling off");
4102 
4103                     // switch mode
4104                     hci_power_control_off();
4105 
4106                     log_info("HCI_STATE_HALTING, emitting state");
4107                     hci_emit_state();
4108                     log_info("HCI_STATE_HALTING, done");
4109                     break;
4110 
4111                 case HCI_HALTING_W4_TIMER:
4112                     // keep waiting
4113 
4114                     break;
4115                 default:
4116                     break;
4117             }
4118 
4119             break;
4120 
4121         case HCI_STATE_FALLING_ASLEEP:
4122             switch(hci_stack->substate) {
4123                 case HCI_FALLING_ASLEEP_DISCONNECT:
4124                     log_info("HCI_STATE_FALLING_ASLEEP");
4125                     // close all open connections
4126                     connection =  (hci_connection_t *) hci_stack->connections;
4127 
4128 #ifdef HAVE_PLATFORM_IPHONE_OS
4129                     // don't close connections, if H4 supports power management
4130                     if (btstack_control_iphone_power_management_enabled()){
4131                         connection = NULL;
4132                     }
4133 #endif
4134                     if (connection){
4135 
4136                         // send disconnect
4137                         if (!hci_can_send_command_packet_now()) return;
4138 
4139                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
4140                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4141 
4142                         // send disconnected event right away - causes higher layer connections to get closed, too.
4143                         hci_shutdown_connection(connection);
4144                         return;
4145                     }
4146 
4147                     if (hci_classic_supported()){
4148                         // disable page and inquiry scan
4149                         if (!hci_can_send_command_packet_now()) return;
4150 
4151                         log_info("HCI_STATE_HALTING, disabling inq scans");
4152                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
4153 
4154                         // continue in next sub state
4155                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
4156                         break;
4157                     }
4158 
4159                     /* fall through */
4160 
4161                 case HCI_FALLING_ASLEEP_COMPLETE:
4162                     log_info("HCI_STATE_HALTING, calling sleep");
4163 #ifdef HAVE_PLATFORM_IPHONE_OS
4164                     // don't actually go to sleep, if H4 supports power management
4165                     if (btstack_control_iphone_power_management_enabled()){
4166                         // SLEEP MODE reached
4167                         hci_stack->state = HCI_STATE_SLEEPING;
4168                         hci_emit_state();
4169                         break;
4170                     }
4171 #endif
4172                     // switch mode
4173                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
4174                     hci_emit_state();
4175                     break;
4176 
4177                 default:
4178                     break;
4179             }
4180             break;
4181 
4182         default:
4183             break;
4184     }
4185 }
4186 
4187 int hci_send_cmd_packet(uint8_t *packet, int size){
4188     // house-keeping
4189 
4190 #ifdef ENABLE_CLASSIC
4191     bd_addr_t addr;
4192     hci_connection_t * conn;
4193     uint8_t initiator_filter_policy;
4194 #endif
4195 
4196     uint16_t opcode = little_endian_read_16(packet, 0);
4197     switch (opcode) {
4198         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
4199             hci_stack->loopback_mode = packet[3];
4200             break;
4201 
4202 #ifdef ENABLE_CLASSIC
4203         case HCI_OPCODE_HCI_CREATE_CONNECTION:
4204             reverse_bd_addr(&packet[3], addr);
4205             log_info("Create_connection to %s", bd_addr_to_str(addr));
4206 
4207             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4208             if (!conn) {
4209                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4210                 if (!conn) {
4211                     // notify client that alloc failed
4212                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4213                     return -1; // packet not sent to controller
4214                 }
4215                 conn->state = SEND_CREATE_CONNECTION;
4216             }
4217             log_info("conn state %u", conn->state);
4218             switch (conn->state) {
4219                 // if connection active exists
4220                 case OPEN:
4221                     // and OPEN, emit connection complete command
4222                     hci_emit_connection_complete(addr, conn->con_handle, 0);
4223                     return -1; // packet not sent to controller
4224                 case RECEIVED_DISCONNECTION_COMPLETE:
4225                     // create connection triggered in disconnect complete event, let's do it now
4226                     break;
4227                 case SEND_CREATE_CONNECTION:
4228                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
4229                     break;
4230                 default:
4231                     // otherwise, just ignore as it is already in the open process
4232                     return -1; // packet not sent to controller
4233             }
4234             conn->state = SENT_CREATE_CONNECTION;
4235 
4236             // track outgoing connection
4237             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
4238             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
4239             break;
4240         case HCI_OPCODE_HCI_LINK_KEY_REQUEST_REPLY:
4241             hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
4242             break;
4243         case HCI_OPCODE_HCI_LINK_KEY_REQUEST_NEGATIVE_REPLY:
4244             hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
4245             break;
4246         case HCI_OPCODE_HCI_DELETE_STORED_LINK_KEY:
4247             if (hci_stack->link_key_db) {
4248                 reverse_bd_addr(&packet[3], addr);
4249                 hci_stack->link_key_db->delete_link_key(addr);
4250             }
4251             break;
4252         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
4253         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_REPLY:
4254             reverse_bd_addr(&packet[3], addr);
4255             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4256             if (conn) {
4257                 connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
4258             }
4259             break;
4260         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
4261         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_REPLY:
4262         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
4263         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_REPLY:
4264             reverse_bd_addr(&packet[3], addr);
4265             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
4266             if (conn) {
4267                 connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
4268             }
4269             break;
4270 
4271 #ifdef ENABLE_SCO_OVER_HCI
4272         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
4273             // setup_synchronous_connection? Voice setting at offset 22
4274             // TODO: compare to current setting if sco connection already active
4275             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
4276             break;
4277         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
4278             // accept_synchronus_connection? Voice setting at offset 18
4279             // TODO: compare to current setting if sco connection already active
4280             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
4281             break;
4282 #endif
4283 #endif
4284 
4285 #ifdef ENABLE_BLE
4286         case HCI_OPCODE_HCI_LE_SET_RANDOM_ADDRESS:
4287             hci_stack->le_random_address_set = 1;
4288             reverse_bd_addr(&packet[3], hci_stack->le_random_address);
4289             break;
4290 #ifdef ENABLE_LE_PERIPHERAL
4291         case HCI_OPCODE_HCI_LE_SET_ADVERTISE_ENABLE:
4292             hci_stack->le_advertisements_active = packet[3];
4293             break;
4294 #endif
4295 #ifdef ENABLE_LE_CENTRAL
4296         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
4297             // white list used?
4298             initiator_filter_policy = packet[7];
4299             switch (initiator_filter_policy) {
4300                 case 0:
4301                     // whitelist not used
4302                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
4303                     break;
4304                 case 1:
4305                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
4306                     break;
4307                 default:
4308                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
4309                     break;
4310             }
4311             break;
4312         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
4313             hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
4314             break;
4315 #endif
4316 #endif
4317         default:
4318             break;
4319     }
4320 
4321     hci_stack->num_cmd_packets--;
4322 
4323     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4324     return hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4325 }
4326 
4327 // disconnect because of security block
4328 void hci_disconnect_security_block(hci_con_handle_t con_handle){
4329     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4330     if (!connection) return;
4331     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
4332 }
4333 
4334 
4335 // Configure Secure Simple Pairing
4336 
4337 #ifdef ENABLE_CLASSIC
4338 
4339 // enable will enable SSP during init
4340 void gap_ssp_set_enable(int enable){
4341     hci_stack->ssp_enable = enable;
4342 }
4343 
4344 static int hci_local_ssp_activated(void){
4345     return gap_ssp_supported() && hci_stack->ssp_enable;
4346 }
4347 
4348 // if set, BTstack will respond to io capability request using authentication requirement
4349 void gap_ssp_set_io_capability(int io_capability){
4350     hci_stack->ssp_io_capability = io_capability;
4351 }
4352 void gap_ssp_set_authentication_requirement(int authentication_requirement){
4353     hci_stack->ssp_authentication_requirement = authentication_requirement;
4354 }
4355 
4356 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
4357 void gap_ssp_set_auto_accept(int auto_accept){
4358     hci_stack->ssp_auto_accept = auto_accept;
4359 }
4360 
4361 void gap_secure_connections_enable(bool enable){
4362     hci_stack->secure_connections_enable = enable;
4363 }
4364 
4365 #endif
4366 
4367 // va_list part of hci_send_cmd
4368 int hci_send_cmd_va_arg(const hci_cmd_t *cmd, va_list argptr){
4369     if (!hci_can_send_command_packet_now()){
4370         log_error("hci_send_cmd called but cannot send packet now");
4371         return 0;
4372     }
4373 
4374     // for HCI INITIALIZATION
4375     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
4376     hci_stack->last_cmd_opcode = cmd->opcode;
4377 
4378     hci_reserve_packet_buffer();
4379     uint8_t * packet = hci_stack->hci_packet_buffer;
4380     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
4381     int err = hci_send_cmd_packet(packet, size);
4382 
4383     // release packet buffer on error or for synchronous transport implementations
4384     if ((err < 0) || hci_transport_synchronous()){
4385         hci_release_packet_buffer();
4386         hci_emit_transport_packet_sent();
4387     }
4388 
4389     return err;
4390 }
4391 
4392 /**
4393  * pre: numcmds >= 0 - it's allowed to send a command to the controller
4394  */
4395 int hci_send_cmd(const hci_cmd_t *cmd, ...){
4396     va_list argptr;
4397     va_start(argptr, cmd);
4398     int res = hci_send_cmd_va_arg(cmd, argptr);
4399     va_end(argptr);
4400     return res;
4401 }
4402 
4403 // Create various non-HCI events.
4404 // TODO: generalize, use table similar to hci_create_command
4405 
4406 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
4407     // dump packet
4408     if (dump) {
4409         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
4410     }
4411 
4412     // dispatch to all event handlers
4413     btstack_linked_list_iterator_t it;
4414     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
4415     while (btstack_linked_list_iterator_has_next(&it)){
4416         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
4417         entry->callback(HCI_EVENT_PACKET, 0, event, size);
4418     }
4419 }
4420 
4421 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
4422     if (!hci_stack->acl_packet_handler) return;
4423     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
4424 }
4425 
4426 #ifdef ENABLE_CLASSIC
4427 static void hci_notify_if_sco_can_send_now(void){
4428     // notify SCO sender if waiting
4429     if (!hci_stack->sco_waiting_for_can_send_now) return;
4430     if (hci_can_send_sco_packet_now()){
4431         hci_stack->sco_waiting_for_can_send_now = 0;
4432         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
4433         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
4434         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
4435     }
4436 }
4437 
4438 // parsing end emitting has been merged to reduce code size
4439 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
4440     uint8_t event[19+GAP_INQUIRY_MAX_NAME_LEN];
4441 
4442     uint8_t * eir_data;
4443     ad_context_t context;
4444     const uint8_t * name;
4445     uint8_t         name_len;
4446 
4447     if (size < 3) return;
4448 
4449     int event_type = hci_event_packet_get_type(packet);
4450     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
4451     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
4452 
4453     switch (event_type){
4454         case HCI_EVENT_INQUIRY_RESULT:
4455         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4456             if (size != (3 + (num_responses * 14))) return;
4457             break;
4458         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4459             if (size != 257) return;
4460             if (num_responses != 1) return;
4461             break;
4462         default:
4463             return;
4464     }
4465 
4466     // event[1] is set at the end
4467     int i;
4468     for (i=0; i<num_responses;i++){
4469         memset(event, 0, sizeof(event));
4470         event[0] = GAP_EVENT_INQUIRY_RESULT;
4471         uint8_t event_size = 18;    // if name is not set by EIR
4472 
4473         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
4474         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
4475         (void)memcpy(&event[9],
4476                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
4477                      3); // class of device
4478         (void)memcpy(&event[12],
4479                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
4480                      2); // clock offset
4481 
4482         switch (event_type){
4483             case HCI_EVENT_INQUIRY_RESULT:
4484                 // 14,15,16,17 = 0, size 18
4485                 break;
4486             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
4487                 event[14] = 1;
4488                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4489                 // 16,17 = 0, size 18
4490                 break;
4491             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
4492                 event[14] = 1;
4493                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
4494                 // EIR packets only contain a single inquiry response
4495                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
4496                 name = NULL;
4497                 // Iterate over EIR data
4498                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
4499                     uint8_t data_type    = ad_iterator_get_data_type(&context);
4500                     uint8_t data_size    = ad_iterator_get_data_len(&context);
4501                     const uint8_t * data = ad_iterator_get_data(&context);
4502                     // Prefer Complete Local Name over Shortend Local Name
4503                     switch (data_type){
4504                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
4505                             if (name) continue;
4506                             /* fall through */
4507                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
4508                             name = data;
4509                             name_len = data_size;
4510                             break;
4511                         default:
4512                             break;
4513                     }
4514                 }
4515                 if (name){
4516                     event[16] = 1;
4517                     // truncate name if needed
4518                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
4519                     event[17] = len;
4520                     (void)memcpy(&event[18], name, len);
4521                     event_size += len;
4522                 }
4523                 break;
4524         }
4525         event[1] = event_size - 2;
4526         hci_emit_event(event, event_size, 1);
4527     }
4528 }
4529 #endif
4530 
4531 void hci_emit_state(void){
4532     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
4533     uint8_t event[3];
4534     event[0] = BTSTACK_EVENT_STATE;
4535     event[1] = sizeof(event) - 2;
4536     event[2] = hci_stack->state;
4537     hci_emit_event(event, sizeof(event), 1);
4538 }
4539 
4540 #ifdef ENABLE_CLASSIC
4541 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4542     uint8_t event[13];
4543     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
4544     event[1] = sizeof(event) - 2;
4545     event[2] = status;
4546     little_endian_store_16(event, 3, con_handle);
4547     reverse_bd_addr(address, &event[5]);
4548     event[11] = 1; // ACL connection
4549     event[12] = 0; // encryption disabled
4550     hci_emit_event(event, sizeof(event), 1);
4551 }
4552 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
4553     if (disable_l2cap_timeouts) return;
4554     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
4555     uint8_t event[4];
4556     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
4557     event[1] = sizeof(event) - 2;
4558     little_endian_store_16(event, 2, conn->con_handle);
4559     hci_emit_event(event, sizeof(event), 1);
4560 }
4561 #endif
4562 
4563 #ifdef ENABLE_BLE
4564 #ifdef ENABLE_LE_CENTRAL
4565 static void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
4566     uint8_t event[21];
4567     event[0] = HCI_EVENT_LE_META;
4568     event[1] = sizeof(event) - 2;
4569     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
4570     event[3] = status;
4571     little_endian_store_16(event, 4, con_handle);
4572     event[6] = 0; // TODO: role
4573     event[7] = address_type;
4574     reverse_bd_addr(address, &event[8]);
4575     little_endian_store_16(event, 14, 0); // interval
4576     little_endian_store_16(event, 16, 0); // latency
4577     little_endian_store_16(event, 18, 0); // supervision timeout
4578     event[20] = 0; // master clock accuracy
4579     hci_emit_event(event, sizeof(event), 1);
4580 }
4581 #endif
4582 #endif
4583 
4584 static void hci_emit_transport_packet_sent(void){
4585     // notify upper stack that it might be possible to send again
4586     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
4587     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
4588 }
4589 
4590 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
4591     uint8_t event[6];
4592     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
4593     event[1] = sizeof(event) - 2;
4594     event[2] = 0; // status = OK
4595     little_endian_store_16(event, 3, con_handle);
4596     event[5] = reason;
4597     hci_emit_event(event, sizeof(event), 1);
4598 }
4599 
4600 static void hci_emit_nr_connections_changed(void){
4601     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
4602     uint8_t event[3];
4603     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
4604     event[1] = sizeof(event) - 2;
4605     event[2] = nr_hci_connections();
4606     hci_emit_event(event, sizeof(event), 1);
4607 }
4608 
4609 static void hci_emit_hci_open_failed(void){
4610     log_info("BTSTACK_EVENT_POWERON_FAILED");
4611     uint8_t event[2];
4612     event[0] = BTSTACK_EVENT_POWERON_FAILED;
4613     event[1] = sizeof(event) - 2;
4614     hci_emit_event(event, sizeof(event), 1);
4615 }
4616 
4617 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
4618     log_info("hci_emit_dedicated_bonding_result %u ", status);
4619     uint8_t event[9];
4620     int pos = 0;
4621     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
4622     event[pos++] = sizeof(event) - 2;
4623     event[pos++] = status;
4624     reverse_bd_addr(address, &event[pos]);
4625     hci_emit_event(event, sizeof(event), 1);
4626 }
4627 
4628 
4629 #ifdef ENABLE_CLASSIC
4630 
4631 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
4632     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
4633     uint8_t event[5];
4634     int pos = 0;
4635     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
4636     event[pos++] = sizeof(event) - 2;
4637     little_endian_store_16(event, 2, con_handle);
4638     pos += 2;
4639     event[pos++] = level;
4640     hci_emit_event(event, sizeof(event), 1);
4641 }
4642 
4643 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
4644     if (!connection) return LEVEL_0;
4645     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
4646     if ((connection->authentication_flags & CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
4647     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
4648     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
4649     // LEVEL 4 always requires 128 bit encrytion key size
4650     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
4651         security_level = LEVEL_3;
4652     }
4653     return security_level;
4654 }
4655 
4656 static void hci_emit_discoverable_enabled(uint8_t enabled){
4657     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
4658     uint8_t event[3];
4659     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
4660     event[1] = sizeof(event) - 2;
4661     event[2] = enabled;
4662     hci_emit_event(event, sizeof(event), 1);
4663 }
4664 
4665 // query if remote side supports eSCO
4666 int hci_remote_esco_supported(hci_con_handle_t con_handle){
4667     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4668     if (!connection) return 0;
4669     return (connection->remote_supported_features[0] & 1) != 0;
4670 }
4671 
4672 static bool hci_ssp_supported(hci_connection_t * connection){
4673     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
4674     return (connection->bonding_flags & mask) == mask;
4675 }
4676 
4677 // query if remote side supports SSP
4678 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
4679     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4680     if (!connection) return 0;
4681     return hci_ssp_supported(connection) ? 1 : 0;
4682 }
4683 
4684 int gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
4685     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
4686 }
4687 
4688 // GAP API
4689 /**
4690  * @bbrief enable/disable bonding. default is enabled
4691  * @praram enabled
4692  */
4693 void gap_set_bondable_mode(int enable){
4694     hci_stack->bondable = enable ? 1 : 0;
4695 }
4696 /**
4697  * @brief Get bondable mode.
4698  * @return 1 if bondable
4699  */
4700 int gap_get_bondable_mode(void){
4701     return hci_stack->bondable;
4702 }
4703 
4704 /**
4705  * @brief map link keys to security levels
4706  */
4707 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
4708     switch (link_key_type){
4709         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4710             return LEVEL_4;
4711         case COMBINATION_KEY:
4712         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4713             return LEVEL_3;
4714         default:
4715             return LEVEL_2;
4716     }
4717 }
4718 
4719 /**
4720  * @brief map link keys to secure connection yes/no
4721  */
4722 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
4723     switch (link_key_type){
4724         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4725         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4726             return 1;
4727         default:
4728             return 0;
4729     }
4730 }
4731 
4732 /**
4733  * @brief map link keys to authenticated
4734  */
4735 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
4736     switch (link_key_type){
4737         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
4738         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
4739             return 1;
4740         default:
4741             return 0;
4742     }
4743 }
4744 
4745 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
4746     log_info("gap_mitm_protection_required_for_security_level %u", level);
4747     return level > LEVEL_2;
4748 }
4749 
4750 /**
4751  * @brief get current security level
4752  */
4753 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
4754     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4755     if (!connection) return LEVEL_0;
4756     return gap_security_level_for_connection(connection);
4757 }
4758 
4759 /**
4760  * @brief request connection to device to
4761  * @result GAP_AUTHENTICATION_RESULT
4762  */
4763 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
4764     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4765     if (!connection){
4766         hci_emit_security_level(con_handle, LEVEL_0);
4767         return;
4768     }
4769     gap_security_level_t current_level = gap_security_level(con_handle);
4770     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
4771         requested_level, connection->requested_security_level, current_level);
4772 
4773     // assumption: earlier requested security higher than current level => security request is active
4774     if (current_level < connection->requested_security_level){
4775         if (connection->requested_security_level < requested_level){
4776             // increase requested level as new level is higher
4777 
4778             // TODO: handle re-authentication when done
4779 
4780             connection->requested_security_level = requested_level;
4781         }
4782         return;
4783     }
4784 
4785     // no request active, notify if security sufficient
4786     if (requested_level <= current_level){
4787         hci_emit_security_level(con_handle, current_level);
4788         return;
4789     }
4790 
4791     // start pairing to increase security level
4792     connection->requested_security_level = requested_level;
4793 
4794 #if 0
4795     // sending encryption request without a link key results in an error.
4796     // TODO: figure out how to use it properly
4797 
4798     // would enabling ecnryption suffice (>= LEVEL_2)?
4799     if (hci_stack->link_key_db){
4800         link_key_type_t link_key_type;
4801         link_key_t      link_key;
4802         if (hci_stack->link_key_db->get_link_key( &connection->address, &link_key, &link_key_type)){
4803             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
4804                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
4805                 return;
4806             }
4807         }
4808     }
4809 #endif
4810 
4811     // start to authenticate connection if not already active
4812     if ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
4813     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
4814     hci_run();
4815 }
4816 
4817 /**
4818  * @brief start dedicated bonding with device. disconnect after bonding
4819  * @param device
4820  * @param request MITM protection
4821  * @result GAP_DEDICATED_BONDING_COMPLETE
4822  */
4823 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
4824 
4825     // create connection state machine
4826     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
4827 
4828     if (!connection){
4829         return BTSTACK_MEMORY_ALLOC_FAILED;
4830     }
4831 
4832     // delete linkn key
4833     gap_drop_link_key_for_bd_addr(device);
4834 
4835     // configure LEVEL_2/3, dedicated bonding
4836     connection->state = SEND_CREATE_CONNECTION;
4837     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
4838     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
4839     connection->bonding_flags = BONDING_DEDICATED;
4840 
4841     // wait for GAP Security Result and send GAP Dedicated Bonding complete
4842 
4843     // handle: connnection failure (connection complete != ok)
4844     // handle: authentication failure
4845     // handle: disconnect on done
4846 
4847     hci_run();
4848 
4849     return 0;
4850 }
4851 #endif
4852 
4853 void gap_set_local_name(const char * local_name){
4854     hci_stack->local_name = local_name;
4855 }
4856 
4857 
4858 #ifdef ENABLE_BLE
4859 
4860 #ifdef ENABLE_LE_CENTRAL
4861 void gap_start_scan(void){
4862     hci_stack->le_scanning_enabled = 1;
4863     hci_run();
4864 }
4865 
4866 void gap_stop_scan(void){
4867     hci_stack->le_scanning_enabled = 0;
4868     hci_run();
4869 }
4870 
4871 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
4872     hci_stack->le_scan_type     = scan_type;
4873     hci_stack->le_scan_interval = scan_interval;
4874     hci_stack->le_scan_window   = scan_window;
4875     hci_run();
4876 }
4877 
4878 uint8_t gap_connect(bd_addr_t addr, bd_addr_type_t addr_type){
4879     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
4880     if (!conn){
4881         log_info("gap_connect: no connection exists yet, creating context");
4882         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
4883         if (!conn){
4884             // notify client that alloc failed
4885             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
4886             log_info("gap_connect: failed to alloc hci_connection_t");
4887             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
4888         }
4889         conn->state = SEND_CREATE_CONNECTION;
4890         log_info("gap_connect: send create connection next");
4891         hci_run();
4892         return ERROR_CODE_SUCCESS;
4893     }
4894 
4895     if (!hci_is_le_connection(conn) ||
4896         (conn->state == SEND_CREATE_CONNECTION) ||
4897         (conn->state == SENT_CREATE_CONNECTION)) {
4898         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
4899         log_error("gap_connect: classic connection or connect is already being created");
4900         return GATT_CLIENT_IN_WRONG_STATE;
4901     }
4902 
4903     // check if connection was just disconnected
4904     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
4905         log_info("gap_connect: send create connection (again)");
4906         conn->state = SEND_CREATE_CONNECTION;
4907         hci_run();
4908         return ERROR_CODE_SUCCESS;
4909     }
4910 
4911     log_info("gap_connect: context exists with state %u", conn->state);
4912     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
4913     hci_run();
4914     return ERROR_CODE_SUCCESS;
4915 }
4916 
4917 // @assumption: only a single outgoing LE Connection exists
4918 static hci_connection_t * gap_get_outgoing_connection(void){
4919     btstack_linked_item_t *it;
4920     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4921         hci_connection_t * conn = (hci_connection_t *) it;
4922         if (!hci_is_le_connection(conn)) continue;
4923         switch (conn->state){
4924             case SEND_CREATE_CONNECTION:
4925             case SENT_CREATE_CONNECTION:
4926             case SENT_CANCEL_CONNECTION:
4927                 return conn;
4928             default:
4929                 break;
4930         };
4931     }
4932     return NULL;
4933 }
4934 
4935 uint8_t gap_connect_cancel(void){
4936     hci_connection_t * conn = gap_get_outgoing_connection();
4937     if (!conn) return 0;
4938     switch (conn->state){
4939         case SEND_CREATE_CONNECTION:
4940             // skip sending create connection and emit event instead
4941             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
4942             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
4943             btstack_memory_hci_connection_free( conn );
4944             break;
4945         case SENT_CREATE_CONNECTION:
4946             // request to send cancel connection
4947             conn->state = SEND_CANCEL_CONNECTION;
4948             hci_run();
4949             break;
4950         default:
4951             break;
4952     }
4953     return 0;
4954 }
4955 #endif
4956 
4957 #ifdef ENABLE_LE_CENTRAL
4958 /**
4959  * @brief Set connection parameters for outgoing connections
4960  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
4961  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
4962  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
4963  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
4964  * @param conn_latency, default: 4
4965  * @param supervision_timeout (unit: 10ms), default: 720 ms
4966  * @param min_ce_length (unit: 0.625ms), default: 10 ms
4967  * @param max_ce_length (unit: 0.625ms), default: 30 ms
4968  */
4969 
4970 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
4971     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
4972     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
4973     hci_stack->le_connection_scan_interval = conn_scan_interval;
4974     hci_stack->le_connection_scan_window = conn_scan_window;
4975     hci_stack->le_connection_interval_min = conn_interval_min;
4976     hci_stack->le_connection_interval_max = conn_interval_max;
4977     hci_stack->le_connection_latency = conn_latency;
4978     hci_stack->le_supervision_timeout = supervision_timeout;
4979     hci_stack->le_minimum_ce_length = min_ce_length;
4980     hci_stack->le_maximum_ce_length = max_ce_length;
4981 }
4982 #endif
4983 
4984 /**
4985  * @brief Updates the connection parameters for a given LE connection
4986  * @param handle
4987  * @param conn_interval_min (unit: 1.25ms)
4988  * @param conn_interval_max (unit: 1.25ms)
4989  * @param conn_latency
4990  * @param supervision_timeout (unit: 10ms)
4991  * @returns 0 if ok
4992  */
4993 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
4994     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
4995     hci_connection_t * connection = hci_connection_for_handle(con_handle);
4996     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
4997     connection->le_conn_interval_min = conn_interval_min;
4998     connection->le_conn_interval_max = conn_interval_max;
4999     connection->le_conn_latency = conn_latency;
5000     connection->le_supervision_timeout = supervision_timeout;
5001     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5002     hci_run();
5003     return 0;
5004 }
5005 
5006 /**
5007  * @brief Request an update of the connection parameter for a given LE connection
5008  * @param handle
5009  * @param conn_interval_min (unit: 1.25ms)
5010  * @param conn_interval_max (unit: 1.25ms)
5011  * @param conn_latency
5012  * @param supervision_timeout (unit: 10ms)
5013  * @returns 0 if ok
5014  */
5015 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5016     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5017     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5018     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5019     connection->le_conn_interval_min = conn_interval_min;
5020     connection->le_conn_interval_max = conn_interval_max;
5021     connection->le_conn_latency = conn_latency;
5022     connection->le_supervision_timeout = supervision_timeout;
5023     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
5024     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
5025     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
5026     return 0;
5027 }
5028 
5029 #ifdef ENABLE_LE_PERIPHERAL
5030 
5031 static void gap_advertisments_changed(void){
5032     // disable advertisements before updating adv, scan data, or adv params
5033     if (hci_stack->le_advertisements_active){
5034         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE | LE_ADVERTISEMENT_TASKS_ENABLE;
5035     }
5036     hci_run();
5037 }
5038 
5039 /**
5040  * @brief Set Advertisement Data
5041  * @param advertising_data_length
5042  * @param advertising_data (max 31 octets)
5043  * @note data is not copied, pointer has to stay valid
5044  */
5045 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
5046     hci_stack->le_advertisements_data_len = advertising_data_length;
5047     hci_stack->le_advertisements_data = advertising_data;
5048     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
5049     gap_advertisments_changed();
5050 }
5051 
5052 /**
5053  * @brief Set Scan Response Data
5054  * @param advertising_data_length
5055  * @param advertising_data (max 31 octets)
5056  * @note data is not copied, pointer has to stay valid
5057  */
5058 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
5059     hci_stack->le_scan_response_data_len = scan_response_data_length;
5060     hci_stack->le_scan_response_data = scan_response_data;
5061     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
5062     gap_advertisments_changed();
5063 }
5064 
5065 /**
5066  * @brief Set Advertisement Parameters
5067  * @param adv_int_min
5068  * @param adv_int_max
5069  * @param adv_type
5070  * @param direct_address_type
5071  * @param direct_address
5072  * @param channel_map
5073  * @param filter_policy
5074  *
5075  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
5076  */
5077  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
5078     uint8_t direct_address_typ, bd_addr_t direct_address,
5079     uint8_t channel_map, uint8_t filter_policy) {
5080 
5081     hci_stack->le_advertisements_interval_min = adv_int_min;
5082     hci_stack->le_advertisements_interval_max = adv_int_max;
5083     hci_stack->le_advertisements_type = adv_type;
5084     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
5085     hci_stack->le_advertisements_channel_map = channel_map;
5086     hci_stack->le_advertisements_filter_policy = filter_policy;
5087     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
5088                  6);
5089 
5090     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5091     gap_advertisments_changed();
5092  }
5093 
5094 /**
5095  * @brief Enable/Disable Advertisements
5096  * @param enabled
5097  */
5098 void gap_advertisements_enable(int enabled){
5099     hci_stack->le_advertisements_enabled = enabled;
5100     if (enabled && !hci_stack->le_advertisements_active){
5101         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
5102     }
5103     if (!enabled && hci_stack->le_advertisements_active){
5104         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE;
5105     }
5106     hci_run();
5107 }
5108 
5109 #endif
5110 
5111 void hci_le_set_own_address_type(uint8_t own_address_type){
5112     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
5113     if (own_address_type == hci_stack->le_own_addr_type) return;
5114     hci_stack->le_own_addr_type = own_address_type;
5115 
5116 #ifdef ENABLE_LE_PERIPHERAL
5117     // update advertisement parameters, too
5118     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
5119     gap_advertisments_changed();
5120 #endif
5121 #ifdef ENABLE_LE_CENTRAL
5122     // note: we don't update scan parameters or modify ongoing connection attempts
5123 #endif
5124 }
5125 
5126 #endif
5127 
5128 uint8_t gap_disconnect(hci_con_handle_t handle){
5129     hci_connection_t * conn = hci_connection_for_handle(handle);
5130     if (!conn){
5131         hci_emit_disconnection_complete(handle, 0);
5132         return 0;
5133     }
5134     // ignore if already disconnected
5135     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5136         return 0;
5137     }
5138     conn->state = SEND_DISCONNECT;
5139     hci_run();
5140     return 0;
5141 }
5142 
5143 int gap_read_rssi(hci_con_handle_t con_handle){
5144     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5145     if (hci_connection == NULL) return 0;
5146     connectionSetAuthenticationFlags(hci_connection, READ_RSSI);
5147     hci_run();
5148     return 1;
5149 }
5150 
5151 /**
5152  * @brief Get connection type
5153  * @param con_handle
5154  * @result connection_type
5155  */
5156 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
5157     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5158     if (!conn) return GAP_CONNECTION_INVALID;
5159     switch (conn->address_type){
5160         case BD_ADDR_TYPE_LE_PUBLIC:
5161         case BD_ADDR_TYPE_LE_RANDOM:
5162             return GAP_CONNECTION_LE;
5163         case BD_ADDR_TYPE_SCO:
5164             return GAP_CONNECTION_SCO;
5165         case BD_ADDR_TYPE_ACL:
5166             return GAP_CONNECTION_ACL;
5167         default:
5168             return GAP_CONNECTION_INVALID;
5169     }
5170 }
5171 
5172 #ifdef ENABLE_BLE
5173 
5174 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){
5175     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5176     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5177 
5178     conn->le_phy_update_all_phys    = all_phys;
5179     conn->le_phy_update_tx_phys     = tx_phys;
5180     conn->le_phy_update_rx_phys     = rx_phys;
5181     conn->le_phy_update_phy_options = phy_options;
5182 
5183     hci_run();
5184 
5185     return 0;
5186 }
5187 
5188 #ifdef ENABLE_LE_CENTRAL
5189 /**
5190  * @brief Auto Connection Establishment - Start Connecting to device
5191  * @param address_typ
5192  * @param address
5193  * @returns 0 if ok
5194  */
5195 int gap_auto_connection_start(bd_addr_type_t address_type, bd_addr_t address){
5196     // check capacity
5197     int num_entries = btstack_linked_list_count(&hci_stack->le_whitelist);
5198     if (num_entries >= hci_stack->le_whitelist_capacity) return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
5199     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
5200     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
5201     entry->address_type = address_type;
5202     (void)memcpy(entry->address, address, 6);
5203     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
5204     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
5205     hci_run();
5206     return 0;
5207 }
5208 
5209 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address){
5210     btstack_linked_list_iterator_t it;
5211     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5212     while (btstack_linked_list_iterator_has_next(&it)){
5213         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5214         if (entry->address_type != address_type) continue;
5215         if (memcmp(entry->address, address, 6) != 0) continue;
5216         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5217             // remove from controller if already present
5218             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5219             continue;
5220         }
5221         // direclty remove entry from whitelist
5222         btstack_linked_list_iterator_remove(&it);
5223         btstack_memory_whitelist_entry_free(entry);
5224     }
5225 }
5226 
5227 /**
5228  * @brief Auto Connection Establishment - Stop Connecting to device
5229  * @param address_typ
5230  * @param address
5231  * @returns 0 if ok
5232  */
5233 int gap_auto_connection_stop(bd_addr_type_t address_type, bd_addr_t address){
5234     hci_remove_from_whitelist(address_type, address);
5235     hci_run();
5236     return 0;
5237 }
5238 
5239 /**
5240  * @brief Auto Connection Establishment - Stop everything
5241  * @note  Convenience function to stop all active auto connection attempts
5242  */
5243 void gap_auto_connection_stop_all(void){
5244     btstack_linked_list_iterator_t it;
5245     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
5246     while (btstack_linked_list_iterator_has_next(&it)){
5247         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
5248         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
5249             // remove from controller if already present
5250             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
5251             continue;
5252         }
5253         // directly remove entry from whitelist
5254         btstack_linked_list_iterator_remove(&it);
5255         btstack_memory_whitelist_entry_free(entry);
5256     }
5257     hci_run();
5258 }
5259 
5260 uint16_t gap_le_connection_interval(hci_con_handle_t connection_handle){
5261     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
5262     if (!conn) return 0;
5263     return conn->le_connection_interval;
5264 }
5265 #endif
5266 #endif
5267 
5268 #ifdef ENABLE_CLASSIC
5269 /**
5270  * @brief Set Extended Inquiry Response data
5271  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
5272  * @note has to be done before stack starts up
5273  */
5274 void gap_set_extended_inquiry_response(const uint8_t * data){
5275     hci_stack->eir_data = data;
5276 }
5277 
5278 /**
5279  * @brief Start GAP Classic Inquiry
5280  * @param duration in 1.28s units
5281  * @return 0 if ok
5282  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
5283  */
5284 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
5285     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
5286     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5287     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
5288         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
5289     }
5290     hci_stack->inquiry_state = duration_in_1280ms_units;
5291     hci_run();
5292     return 0;
5293 }
5294 
5295 /**
5296  * @brief Stop GAP Classic Inquiry
5297  * @returns 0 if ok
5298  */
5299 int gap_inquiry_stop(void){
5300     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
5301         // emit inquiry complete event, before it even started
5302         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
5303         hci_emit_event(event, sizeof(event), 1);
5304         return 0;
5305     }
5306     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
5307     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
5308     hci_run();
5309     return 0;
5310 }
5311 
5312 
5313 /**
5314  * @brief Remote Name Request
5315  * @param addr
5316  * @param page_scan_repetition_mode
5317  * @param clock_offset only used when bit 15 is set
5318  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
5319  */
5320 int gap_remote_name_request(bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
5321     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5322     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
5323     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
5324     hci_stack->remote_name_clock_offset = clock_offset;
5325     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
5326     hci_run();
5327     return 0;
5328 }
5329 
5330 static int gap_pairing_set_state_and_run(bd_addr_t addr, uint8_t state){
5331     hci_stack->gap_pairing_state = state;
5332     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
5333     hci_run();
5334     return 0;
5335 }
5336 
5337 /**
5338  * @brief Legacy Pairing Pin Code Response
5339  * @param addr
5340  * @param pin
5341  * @return 0 if ok
5342  */
5343 int gap_pin_code_response(bd_addr_t addr, const char * pin){
5344     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5345     hci_stack->gap_pairing_input.gap_pairing_pin = pin;
5346     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
5347 }
5348 
5349 /**
5350  * @brief Abort Legacy Pairing
5351  * @param addr
5352  * @param pin
5353  * @return 0 if ok
5354  */
5355 int gap_pin_code_negative(bd_addr_t addr){
5356     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5357     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
5358 }
5359 
5360 /**
5361  * @brief SSP Passkey Response
5362  * @param addr
5363  * @param passkey
5364  * @return 0 if ok
5365  */
5366 int gap_ssp_passkey_response(bd_addr_t addr, uint32_t passkey){
5367     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5368     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
5369     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
5370 }
5371 
5372 /**
5373  * @brief Abort SSP Passkey Entry/Pairing
5374  * @param addr
5375  * @param pin
5376  * @return 0 if ok
5377  */
5378 int gap_ssp_passkey_negative(bd_addr_t addr){
5379     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5380     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
5381 }
5382 
5383 /**
5384  * @brief Accept SSP Numeric Comparison
5385  * @param addr
5386  * @param passkey
5387  * @return 0 if ok
5388  */
5389 int gap_ssp_confirmation_response(bd_addr_t addr){
5390     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5391     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
5392 }
5393 
5394 /**
5395  * @brief Abort SSP Numeric Comparison/Pairing
5396  * @param addr
5397  * @param pin
5398  * @return 0 if ok
5399  */
5400 int gap_ssp_confirmation_negative(bd_addr_t addr){
5401     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
5402     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
5403 }
5404 
5405 /**
5406  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
5407  * @param inquiry_mode see bluetooth_defines.h
5408  */
5409 void hci_set_inquiry_mode(inquiry_mode_t mode){
5410     hci_stack->inquiry_mode = mode;
5411 }
5412 
5413 /**
5414  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
5415  */
5416 void hci_set_sco_voice_setting(uint16_t voice_setting){
5417     hci_stack->sco_voice_setting = voice_setting;
5418 }
5419 
5420 /**
5421  * @brief Get SCO Voice Setting
5422  * @return current voice setting
5423  */
5424 uint16_t hci_get_sco_voice_setting(void){
5425     return hci_stack->sco_voice_setting;
5426 }
5427 
5428 static int hci_have_usb_transport(void){
5429     if (!hci_stack->hci_transport) return 0;
5430     const char * transport_name = hci_stack->hci_transport->name;
5431     if (!transport_name) return 0;
5432     return (transport_name[0] == 'H') && (transport_name[1] == '2');
5433 }
5434 
5435 /** @brief Get SCO packet length for current SCO Voice setting
5436  *  @note  Using SCO packets of the exact length is required for USB transfer
5437  *  @return Length of SCO packets in bytes (not audio frames)
5438  */
5439 int hci_get_sco_packet_length(void){
5440     int sco_packet_length = 0;
5441 
5442 #ifdef ENABLE_SCO_OVER_HCI
5443 
5444     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
5445     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
5446 
5447     if (hci_have_usb_transport()){
5448         // see Core Spec for H2 USB Transfer.
5449         // 3 byte SCO header + 24 bytes per connection
5450         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
5451         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
5452     } else {
5453         // 3 byte SCO header + SCO packet size over the air (60 bytes)
5454         sco_packet_length = 3 + 60 * multiplier;
5455         // assert that it still fits inside an SCO buffer
5456         if (sco_packet_length > hci_stack->sco_data_packet_length){
5457             sco_packet_length = 3 + 60;
5458         }
5459     }
5460 #endif
5461     return sco_packet_length;
5462 }
5463 
5464 /**
5465 * @brief Sets the master/slave policy
5466 * @param policy (0: attempt to become master, 1: let connecting device decide)
5467 */
5468 void hci_set_master_slave_policy(uint8_t policy){
5469     hci_stack->master_slave_policy = policy;
5470 }
5471 
5472 #endif
5473 
5474 HCI_STATE hci_get_state(void){
5475     return hci_stack->state;
5476 }
5477 
5478 #ifdef ENABLE_CLASSIC
5479 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr)){
5480     hci_stack->gap_classic_accept_callback = accept_callback;
5481 }
5482 #endif
5483 
5484 /**
5485  * @brief Set callback for Bluetooth Hardware Error
5486  */
5487 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
5488     hci_stack->hardware_error_callback = fn;
5489 }
5490 
5491 void hci_disconnect_all(void){
5492     btstack_linked_list_iterator_t it;
5493     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5494     while (btstack_linked_list_iterator_has_next(&it)){
5495         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5496         if (con->state == SENT_DISCONNECT) continue;
5497         con->state = SEND_DISCONNECT;
5498     }
5499     hci_run();
5500 }
5501 
5502 uint16_t hci_get_manufacturer(void){
5503     return hci_stack->manufacturer;
5504 }
5505 
5506 #ifdef ENABLE_BLE
5507 
5508 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
5509     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
5510     if (!hci_con) return NULL;
5511     return &hci_con->sm_connection;
5512 }
5513 
5514 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
5515 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
5516 
5517 int gap_encryption_key_size(hci_con_handle_t con_handle){
5518     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5519     if (hci_connection == NULL) return 0;
5520     if (hci_is_le_connection(hci_connection)){
5521         sm_connection_t * sm_conn = &hci_connection->sm_connection;
5522         if (sm_conn->sm_connection_encrypted) {
5523             return sm_conn->sm_actual_encryption_key_size;
5524         }
5525     }
5526 #ifdef ENABLE_CLASSIC
5527     else {
5528         if ((hci_connection->authentication_flags & CONNECTION_ENCRYPTED)){
5529             return hci_connection->encryption_key_size;
5530         }
5531     }
5532 #endif
5533     return 0;
5534 }
5535 
5536 int gap_authenticated(hci_con_handle_t con_handle){
5537     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5538     if (hci_connection == NULL) return 0;
5539 
5540     switch (hci_connection->address_type){
5541         case BD_ADDR_TYPE_LE_PUBLIC:
5542         case BD_ADDR_TYPE_LE_RANDOM:
5543             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5544             return hci_connection->sm_connection.sm_connection_authenticated;
5545 #ifdef ENABLE_CLASSIC
5546         case BD_ADDR_TYPE_SCO:
5547         case BD_ADDR_TYPE_ACL:
5548             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
5549 #endif
5550         default:
5551             return 0;
5552     }
5553 }
5554 
5555 int gap_secure_connection(hci_con_handle_t con_handle){
5556     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
5557     if (hci_connection == NULL) return 0;
5558 
5559     switch (hci_connection->address_type){
5560         case BD_ADDR_TYPE_LE_PUBLIC:
5561         case BD_ADDR_TYPE_LE_RANDOM:
5562             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
5563             return hci_connection->sm_connection.sm_connection_sc;
5564 #ifdef ENABLE_CLASSIC
5565         case BD_ADDR_TYPE_SCO:
5566         case BD_ADDR_TYPE_ACL:
5567             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
5568 #endif
5569         default:
5570             return 0;
5571     }
5572 }
5573 
5574 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
5575     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
5576     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
5577     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
5578     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
5579     return sm_conn->sm_connection_authorization_state;
5580 }
5581 #endif
5582 
5583 #ifdef ENABLE_CLASSIC
5584 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){
5585     hci_connection_t * conn = hci_connection_for_handle(con_handle);
5586     if (!conn) return GAP_CONNECTION_INVALID;
5587     conn->sniff_min_interval = sniff_min_interval;
5588     conn->sniff_max_interval = sniff_max_interval;
5589     conn->sniff_attempt = sniff_attempt;
5590     conn->sniff_timeout = sniff_timeout;
5591     hci_run();
5592     return 0;
5593 }
5594 
5595 /**
5596  * @brief Exit Sniff mode
5597  * @param con_handle
5598  @ @return 0 if ok
5599  */
5600 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
5601     hci_connection_t * conn = hci_connection_for_handle(con_handle);
5602     if (!conn) return GAP_CONNECTION_INVALID;
5603     conn->sniff_min_interval = 0xffff;
5604     hci_run();
5605     return 0;
5606 }
5607 #endif
5608 
5609 void hci_halting_defer(void){
5610     if (hci_stack->state != HCI_STATE_HALTING) return;
5611     switch (hci_stack->substate){
5612         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
5613         case HCI_HALTING_CLOSE:
5614             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
5615             break;
5616         default:
5617             break;
5618     }
5619 }
5620 
5621 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
5622 void hci_setup_test_connections_fuzz(void){
5623     hci_connection_t * conn;
5624 
5625     // default address: 66:55:44:33:00:01
5626     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
5627 
5628     // setup Controller info
5629     hci_stack->num_cmd_packets = 255;
5630     hci_stack->acl_packets_total_num = 255;
5631 
5632     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
5633     addr[5] = 0x01;
5634     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5635     conn->con_handle = addr[5];
5636     conn->role  = HCI_ROLE_SLAVE;
5637     conn->state = RECEIVED_CONNECTION_REQUEST;
5638     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5639 
5640     // setup incoming Classic SCO connection with con handle 0x0002
5641     addr[5] = 0x02;
5642     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
5643     conn->con_handle = addr[5];
5644     conn->role  = HCI_ROLE_SLAVE;
5645     conn->state = RECEIVED_CONNECTION_REQUEST;
5646     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5647 
5648     // setup ready Classic ACL connection with con handle 0x0003
5649     addr[5] = 0x03;
5650     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5651     conn->con_handle = addr[5];
5652     conn->role  = HCI_ROLE_SLAVE;
5653     conn->state = OPEN;
5654     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5655 
5656     // setup ready Classic SCO connection with con handle 0x0004
5657     addr[5] = 0x04;
5658     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
5659     conn->con_handle = addr[5];
5660     conn->role  = HCI_ROLE_SLAVE;
5661     conn->state = OPEN;
5662     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5663 
5664     // setup ready LE ACL connection with con handle 0x005 and public address
5665     addr[5] = 0x05;
5666     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
5667     conn->con_handle = addr[5];
5668     conn->role  = HCI_ROLE_SLAVE;
5669     conn->state = OPEN;
5670     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
5671 }
5672 
5673 void hci_free_connections_fuzz(void){
5674     btstack_linked_list_iterator_t it;
5675     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
5676     while (btstack_linked_list_iterator_has_next(&it)){
5677         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
5678         btstack_linked_list_iterator_remove(&it);
5679         btstack_memory_hci_connection_free(con);
5680     }
5681 }
5682 void hci_simulate_working_fuzz(void){
5683     hci_init_done();
5684     hci_stack->num_cmd_packets = 255;
5685 }
5686 #endif
5687