xref: /btstack/src/hci.c (revision e90bae0148b168505f3c9b81279423e4ad8096b5)
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 /*
39  *  hci.c
40  *
41  *  Created by Matthias Ringwald on 4/29/09.
42  *
43  */
44 
45 #include "btstack_config.h"
46 
47 
48 #ifdef HAVE_EMBEDDED_TICK
49 #include "btstack_run_loop_embedded.h"
50 #endif
51 
52 #ifdef HAVE_PLATFORM_IPHONE_OS
53 #include "../port/ios/src/btstack_control_iphone.h"
54 #endif
55 
56 #ifdef ENABLE_BLE
57 #include "gap.h"
58 #endif
59 
60 #include <stdarg.h>
61 #include <string.h>
62 #include <stdio.h>
63 #include <inttypes.h>
64 
65 #include "btstack_debug.h"
66 #include "btstack_event.h"
67 #include "btstack_linked_list.h"
68 #include "btstack_memory.h"
69 #include "gap.h"
70 #include "hci.h"
71 #include "hci_cmd.h"
72 #include "hci_dump.h"
73 
74 
75 #define HCI_CONNECTION_TIMEOUT_MS 10000
76 #define HCI_RESET_RESEND_TIMEOUT_MS 200
77 
78 // prototypes
79 #ifdef ENABLE_CLASSIC
80 static void hci_update_scan_enable(void);
81 static void hci_emit_discoverable_enabled(uint8_t enabled);
82 static int  hci_local_ssp_activated(void);
83 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
84 static void hci_notify_if_sco_can_send_now(void);
85 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
86 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
87 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
88 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
89 static void hci_connection_timestamp(hci_connection_t *connection);
90 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
91 #endif
92 static int  hci_power_control_on(void);
93 static void hci_power_control_off(void);
94 static void hci_state_reset(void);
95 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
96 static void hci_emit_nr_connections_changed(void);
97 static void hci_emit_hci_open_failed(void);
98 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
99 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
100 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
101 static void hci_run(void);
102 static int  hci_is_le_connection(hci_connection_t * connection);
103 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
104 
105 #ifdef ENABLE_BLE
106 // called from test/ble_client/advertising_data_parser.c
107 void le_handle_advertisement_report(uint8_t *packet, int size);
108 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address);
109 #endif
110 
111 // the STACK is here
112 #ifndef HAVE_MALLOC
113 static hci_stack_t   hci_stack_static;
114 #endif
115 static hci_stack_t * hci_stack = NULL;
116 
117 // test helper
118 static uint8_t disable_l2cap_timeouts = 0;
119 
120 /**
121  * create connection for given address
122  *
123  * @return connection OR NULL, if no memory left
124  */
125 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
126     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
127     hci_connection_t * conn = btstack_memory_hci_connection_get();
128     if (!conn) return NULL;
129     memset(conn, 0, sizeof(hci_connection_t));
130     bd_addr_copy(conn->address, addr);
131     conn->address_type = addr_type;
132     conn->con_handle = 0xffff;
133     conn->authentication_flags = AUTH_FLAGS_NONE;
134     conn->bonding_flags = 0;
135     conn->requested_security_level = LEVEL_0;
136 #ifdef ENABLE_CLASSIC
137     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
138     btstack_run_loop_set_timer_context(&conn->timeout, conn);
139     hci_connection_timestamp(conn);
140 #endif
141     conn->acl_recombination_length = 0;
142     conn->acl_recombination_pos = 0;
143     conn->num_acl_packets_sent = 0;
144     conn->num_sco_packets_sent = 0;
145     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
146     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
147     return conn;
148 }
149 
150 
151 /**
152  * get le connection parameter range
153 *
154  * @return le connection parameter range struct
155  */
156 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
157     *range = hci_stack->le_connection_parameter_range;
158 }
159 
160 /**
161  * set le connection parameter range
162  *
163  */
164 
165 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
166     hci_stack->le_connection_parameter_range = *range;
167 }
168 
169 /**
170  * get hci connections iterator
171  *
172  * @return hci connections iterator
173  */
174 
175 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
176     btstack_linked_list_iterator_init(it, &hci_stack->connections);
177 }
178 
179 /**
180  * get connection for a given handle
181  *
182  * @return connection OR NULL, if not found
183  */
184 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
185     btstack_linked_list_iterator_t it;
186     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
187     while (btstack_linked_list_iterator_has_next(&it)){
188         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
189         if ( item->con_handle == con_handle ) {
190             return item;
191         }
192     }
193     return NULL;
194 }
195 
196 /**
197  * get connection for given address
198  *
199  * @return connection OR NULL, if not found
200  */
201 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t  addr, bd_addr_type_t addr_type){
202     btstack_linked_list_iterator_t it;
203     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
204     while (btstack_linked_list_iterator_has_next(&it)){
205         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
206         if (connection->address_type != addr_type)  continue;
207         if (memcmp(addr, connection->address, 6) != 0) continue;
208         return connection;
209     }
210     return NULL;
211 }
212 
213 
214 #ifdef ENABLE_CLASSIC
215 
216 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
217     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
218 #ifdef HAVE_EMBEDDED_TICK
219     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
220         // connections might be timed out
221         hci_emit_l2cap_check_timeout(connection);
222     }
223 #else
224     if (btstack_run_loop_get_time_ms() > connection->timestamp + HCI_CONNECTION_TIMEOUT_MS){
225         // connections might be timed out
226         hci_emit_l2cap_check_timeout(connection);
227     }
228 #endif
229 }
230 
231 static void hci_connection_timestamp(hci_connection_t *connection){
232 #ifdef HAVE_EMBEDDED_TICK
233     connection->timestamp = btstack_run_loop_embedded_get_ticks();
234 #else
235     connection->timestamp = btstack_run_loop_get_time_ms();
236 #endif
237 }
238 
239 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
240     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
241 }
242 
243 
244 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
245     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
246 }
247 
248 /**
249  * add authentication flags and reset timer
250  * @note: assumes classic connection
251  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
252  */
253 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
254     bd_addr_t addr;
255     reverse_bd_addr(bd_addr, addr);
256     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
257     if (conn) {
258         connectionSetAuthenticationFlags(conn, flags);
259         hci_connection_timestamp(conn);
260     }
261 }
262 
263 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
264     hci_connection_t * conn = hci_connection_for_handle(handle);
265     if (!conn) return 0;
266     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
267     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
268     return 0;
269 }
270 
271 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
272     if (!hci_stack->link_key_db) return;
273     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
274     hci_stack->link_key_db->delete_link_key(addr);
275 }
276 
277 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
278     if (!hci_stack->link_key_db) return;
279     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
280     hci_stack->link_key_db->put_link_key(addr, link_key, type);
281 }
282 #endif
283 
284 static int hci_is_le_connection(hci_connection_t * connection){
285     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
286     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
287 }
288 
289 /**
290  * count connections
291  */
292 static int nr_hci_connections(void){
293     int count = 0;
294     btstack_linked_item_t *it;
295     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
296     return count;
297 }
298 
299 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
300 
301     unsigned int num_packets_sent_classic = 0;
302     unsigned int num_packets_sent_le = 0;
303 
304     btstack_linked_item_t *it;
305     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
306         hci_connection_t * connection = (hci_connection_t *) it;
307         if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
308             num_packets_sent_classic += connection->num_acl_packets_sent;
309         } else {
310             num_packets_sent_le += connection->num_acl_packets_sent;
311         }
312     }
313     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
314     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
315     int free_slots_le = 0;
316 
317     if (free_slots_classic < 0){
318         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);
319         return 0;
320     }
321 
322     if (hci_stack->le_acl_packets_total_num){
323         // if we have LE slots, they are used
324         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
325         if (free_slots_le < 0){
326             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);
327             return 0;
328         }
329     } else {
330         // otherwise, classic slots are used for LE, too
331         free_slots_classic -= num_packets_sent_le;
332         if (free_slots_classic < 0){
333             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);
334             return 0;
335         }
336     }
337 
338     switch (address_type){
339         case BD_ADDR_TYPE_UNKNOWN:
340             log_error("hci_number_free_acl_slots: unknown address type");
341             return 0;
342 
343         case BD_ADDR_TYPE_CLASSIC:
344             return free_slots_classic;
345 
346         default:
347            if (hci_stack->le_acl_packets_total_num){
348                return free_slots_le;
349            }
350            return free_slots_classic;
351     }
352 }
353 
354 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
355     // get connection type
356     hci_connection_t * connection = hci_connection_for_handle(con_handle);
357     if (!connection){
358         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
359         return 0;
360     }
361     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
362 }
363 
364 #ifdef ENABLE_CLASSIC
365 static int hci_number_free_sco_slots(void){
366     unsigned int num_sco_packets_sent  = 0;
367     btstack_linked_item_t *it;
368     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
369         hci_connection_t * connection = (hci_connection_t *) it;
370         num_sco_packets_sent += connection->num_sco_packets_sent;
371     }
372     if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
373         log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
374         return 0;
375     }
376     // log_info("hci_number_free_sco_slots u", handle, num_sco_packets_sent);
377     return hci_stack->sco_packets_total_num - num_sco_packets_sent;
378 }
379 #endif
380 
381 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
382 int hci_can_send_command_packet_now(void){
383     if (hci_stack->hci_packet_buffer_reserved) return 0;
384 
385     // check for async hci transport implementations
386     if (hci_stack->hci_transport->can_send_packet_now){
387         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
388             return 0;
389         }
390     }
391 
392     return hci_stack->num_cmd_packets > 0;
393 }
394 
395 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
396     // check for async hci transport implementations
397     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
398     return hci_stack->hci_transport->can_send_packet_now(packet_type);
399 }
400 
401 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
402     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
403     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
404 }
405 
406 int hci_can_send_acl_le_packet_now(void){
407     if (hci_stack->hci_packet_buffer_reserved) return 0;
408     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
409 }
410 
411 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
412     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
413     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
414 }
415 
416 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
417     if (hci_stack->hci_packet_buffer_reserved) return 0;
418     return hci_can_send_prepared_acl_packet_now(con_handle);
419 }
420 
421 #ifdef ENABLE_CLASSIC
422 int hci_can_send_acl_classic_packet_now(void){
423     if (hci_stack->hci_packet_buffer_reserved) return 0;
424     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_CLASSIC);
425 }
426 
427 int hci_can_send_prepared_sco_packet_now(void){
428     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return 0;
429     if (!hci_stack->synchronous_flow_control_enabled) return 1;
430     return hci_number_free_sco_slots() > 0;
431 }
432 
433 int hci_can_send_sco_packet_now(void){
434     if (hci_stack->hci_packet_buffer_reserved) return 0;
435     return hci_can_send_prepared_sco_packet_now();
436 }
437 
438 void hci_request_sco_can_send_now_event(void){
439     hci_stack->sco_waiting_for_can_send_now = 1;
440     hci_notify_if_sco_can_send_now();
441 }
442 #endif
443 
444 // used for internal checks in l2cap.c
445 int hci_is_packet_buffer_reserved(void){
446     return hci_stack->hci_packet_buffer_reserved;
447 }
448 
449 // reserves outgoing packet buffer. @returns 1 if successful
450 int hci_reserve_packet_buffer(void){
451     if (hci_stack->hci_packet_buffer_reserved) {
452         log_error("hci_reserve_packet_buffer called but buffer already reserved");
453         return 0;
454     }
455     hci_stack->hci_packet_buffer_reserved = 1;
456     return 1;
457 }
458 
459 void hci_release_packet_buffer(void){
460     hci_stack->hci_packet_buffer_reserved = 0;
461 }
462 
463 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
464 static int hci_transport_synchronous(void){
465     return hci_stack->hci_transport->can_send_packet_now == NULL;
466 }
467 
468 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
469 
470     // 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);
471 
472     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
473     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
474     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
475         max_acl_data_packet_length = hci_stack->le_data_packets_length;
476     }
477 
478     // testing: reduce buffer to minimum
479     // max_acl_data_packet_length = 52;
480 
481     log_debug("hci_send_acl_packet_fragments entered");
482 
483     int err;
484     // multiple packets could be send on a synchronous HCI transport
485     while (1){
486 
487         log_debug("hci_send_acl_packet_fragments loop entered");
488 
489         // get current data
490         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
491         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
492         int more_fragments = 0;
493 
494         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
495         if (current_acl_data_packet_length > max_acl_data_packet_length){
496             more_fragments = 1;
497             current_acl_data_packet_length = max_acl_data_packet_length;
498         }
499 
500         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
501         if (acl_header_pos > 0){
502             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
503             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
504             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
505         }
506 
507         // update header len
508         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
509 
510         // count packet
511         connection->num_acl_packets_sent++;
512         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", more_fragments);
513 
514         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
515         if (more_fragments){
516             // update start of next fragment to send
517             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
518         } else {
519             // done
520             hci_stack->acl_fragmentation_pos = 0;
521             hci_stack->acl_fragmentation_total_size = 0;
522         }
523 
524         // send packet
525         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
526         const int size = current_acl_data_packet_length + 4;
527         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
528         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
529 
530         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", more_fragments);
531 
532         // done yet?
533         if (!more_fragments) break;
534 
535         // can send more?
536         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
537     }
538 
539     log_debug("hci_send_acl_packet_fragments loop over");
540 
541     // release buffer now for synchronous transport
542     if (hci_transport_synchronous()){
543         hci_release_packet_buffer();
544         // notify upper stack that it might be possible to send again
545         uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
546         hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
547     }
548 
549     return err;
550 }
551 
552 // pre: caller has reserved the packet buffer
553 int hci_send_acl_packet_buffer(int size){
554 
555     // log_info("hci_send_acl_packet_buffer size %u", size);
556 
557     if (!hci_stack->hci_packet_buffer_reserved) {
558         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
559         return 0;
560     }
561 
562     uint8_t * packet = hci_stack->hci_packet_buffer;
563     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
564 
565     // check for free places on Bluetooth module
566     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
567         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
568         hci_release_packet_buffer();
569         return BTSTACK_ACL_BUFFERS_FULL;
570     }
571 
572     hci_connection_t *connection = hci_connection_for_handle( con_handle);
573     if (!connection) {
574         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
575         hci_release_packet_buffer();
576         return 0;
577     }
578 
579 #ifdef ENABLE_CLASSIC
580     hci_connection_timestamp(connection);
581 #endif
582 
583     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
584 
585     // setup data
586     hci_stack->acl_fragmentation_total_size = size;
587     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
588 
589     return hci_send_acl_packet_fragments(connection);
590 }
591 
592 #ifdef ENABLE_CLASSIC
593 // pre: caller has reserved the packet buffer
594 int hci_send_sco_packet_buffer(int size){
595 
596     // log_info("hci_send_acl_packet_buffer size %u", size);
597 
598     if (!hci_stack->hci_packet_buffer_reserved) {
599         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
600         return 0;
601     }
602 
603     uint8_t * packet = hci_stack->hci_packet_buffer;
604 
605     // skip checks in loopback mode
606     if (!hci_stack->loopback_mode){
607         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
608 
609         // check for free places on Bluetooth module
610         if (!hci_can_send_prepared_sco_packet_now()) {
611             log_error("hci_send_sco_packet_buffer called but no free ACL buffers on controller");
612             hci_release_packet_buffer();
613             return BTSTACK_ACL_BUFFERS_FULL;
614         }
615 
616         // track send packet in connection struct
617         hci_connection_t *connection = hci_connection_for_handle( con_handle);
618         if (!connection) {
619             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
620             hci_release_packet_buffer();
621             return 0;
622         }
623         connection->num_sco_packets_sent++;
624     }
625 
626     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
627     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
628 
629     if (hci_transport_synchronous()){
630         hci_release_packet_buffer();
631         // notify upper stack that it might be possible to send again
632         uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
633         hci_emit_event(&event[0], sizeof(event), 0);    // don't dump
634     }
635 
636     return err;
637 }
638 #endif
639 
640 static void acl_handler(uint8_t *packet, int size){
641 
642     // log_info("acl_handler: size %u", size);
643 
644     // get info
645     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
646     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
647     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
648     uint16_t acl_length         = READ_ACL_LENGTH(packet);
649 
650     // ignore non-registered handle
651     if (!conn){
652         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
653         return;
654     }
655 
656     // assert packet is complete
657     if (acl_length + 4 != size){
658         log_error("hci.c: acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
659         return;
660     }
661 
662 #ifdef ENABLE_CLASSIC
663     // update idle timestamp
664     hci_connection_timestamp(conn);
665 #endif
666 
667     // handle different packet types
668     switch (acl_flags & 0x03) {
669 
670         case 0x01: // continuation fragment
671 
672             // sanity checks
673             if (conn->acl_recombination_pos == 0) {
674                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
675                 return;
676             }
677             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
678                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
679                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
680                 conn->acl_recombination_pos = 0;
681                 return;
682             }
683 
684             // append fragment payload (header already stored)
685             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
686             conn->acl_recombination_pos += acl_length;
687 
688             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
689             //        conn->acl_recombination_pos, conn->acl_recombination_length);
690 
691             // forward complete L2CAP packet if complete.
692             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
693                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
694                 // reset recombination buffer
695                 conn->acl_recombination_length = 0;
696                 conn->acl_recombination_pos = 0;
697             }
698             break;
699 
700         case 0x02: { // first fragment
701 
702             // sanity check
703             if (conn->acl_recombination_pos) {
704                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
705                 conn->acl_recombination_pos = 0;
706             }
707 
708             // peek into L2CAP packet!
709             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
710 
711             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
712 
713             // compare fragment size to L2CAP packet size
714             if (acl_length >= l2cap_length + 4){
715                 // forward fragment as L2CAP packet
716                 hci_emit_acl_packet(packet, acl_length + 4);
717             } else {
718 
719                 if (acl_length > HCI_ACL_BUFFER_SIZE){
720                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
721                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
722                     return;
723                 }
724 
725                 // store first fragment and tweak acl length for complete package
726                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
727                 conn->acl_recombination_pos    = acl_length + 4;
728                 conn->acl_recombination_length = l2cap_length;
729                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
730             }
731             break;
732 
733         }
734         default:
735             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
736             return;
737     }
738 
739     // execute main loop
740     hci_run();
741 }
742 
743 static void hci_shutdown_connection(hci_connection_t *conn){
744     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
745 
746     btstack_run_loop_remove_timer(&conn->timeout);
747 
748     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
749     btstack_memory_hci_connection_free( conn );
750 
751     // now it's gone
752     hci_emit_nr_connections_changed();
753 }
754 
755 #ifdef ENABLE_CLASSIC
756 
757 static const uint16_t packet_type_sizes[] = {
758     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
759     HCI_ACL_DH1_SIZE, 0, 0, 0,
760     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
761     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
762 };
763 static const uint8_t  packet_type_feature_requirement_bit[] = {
764      0, // 3 slot packets
765      1, // 5 slot packets
766     25, // EDR 2 mpbs
767     26, // EDR 3 mbps
768     39, // 3 slot EDR packts
769     40, // 5 slot EDR packet
770 };
771 static const uint16_t packet_type_feature_packet_mask[] = {
772     0x0f00, // 3 slot packets
773     0xf000, // 5 slot packets
774     0x1102, // EDR 2 mpbs
775     0x2204, // EDR 3 mbps
776     0x0300, // 3 slot EDR packts
777     0x3000, // 5 slot EDR packet
778 };
779 
780 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
781     // enable packet types based on size
782     uint16_t packet_types = 0;
783     unsigned int i;
784     for (i=0;i<16;i++){
785         if (packet_type_sizes[i] == 0) continue;
786         if (packet_type_sizes[i] <= buffer_size){
787             packet_types |= 1 << i;
788         }
789     }
790     // disable packet types due to missing local supported features
791     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
792         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
793         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
794         if (feature_set) continue;
795         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
796         packet_types &= ~packet_type_feature_packet_mask[i];
797     }
798     // flip bits for "may not be used"
799     packet_types ^= 0x3306;
800     return packet_types;
801 }
802 
803 uint16_t hci_usable_acl_packet_types(void){
804     return hci_stack->packet_types;
805 }
806 #endif
807 
808 uint8_t* hci_get_outgoing_packet_buffer(void){
809     // hci packet buffer is >= acl data packet length
810     return hci_stack->hci_packet_buffer;
811 }
812 
813 uint16_t hci_max_acl_data_packet_length(void){
814     return hci_stack->acl_data_packet_length;
815 }
816 
817 int hci_extended_sco_link_supported(void){
818     // No. 31, byte 3, bit 7
819     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
820 }
821 
822 int hci_non_flushable_packet_boundary_flag_supported(void){
823     // No. 54, byte 6, bit 6
824     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
825 }
826 
827 static int gap_ssp_supported(void){
828     // No. 51, byte 6, bit 3
829     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
830 }
831 
832 static int hci_classic_supported(void){
833 #ifdef ENABLE_CLASSIC
834     // No. 37, byte 4, bit 5, = No BR/EDR Support
835     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
836 #else
837     return 0;
838 #endif
839 }
840 
841 static int hci_le_supported(void){
842 #ifdef ENABLE_BLE
843     // No. 37, byte 4, bit 6 = LE Supported (Controller)
844     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
845 #else
846     return 0;
847 #endif
848 }
849 
850 // get addr type and address used in advertisement packets
851 void gap_advertisements_get_address(uint8_t * addr_type, bd_addr_t  addr){
852     *addr_type = hci_stack->adv_addr_type;
853     if (hci_stack->adv_addr_type){
854         memcpy(addr, hci_stack->adv_address, 6);
855     } else {
856         memcpy(addr, hci_stack->local_bd_addr, 6);
857     }
858 }
859 
860 #ifdef ENABLE_BLE
861 void le_handle_advertisement_report(uint8_t *packet, int size){
862     int offset = 3;
863     int num_reports = packet[offset];
864     offset += 1;
865 
866     int i;
867     // log_info("HCI: handle adv report with num reports: %d", num_reports);
868     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
869     for (i=0; i<num_reports;i++){
870         uint8_t data_length = packet[offset + 8];
871         uint8_t event_size = 10 + data_length;
872         int pos = 0;
873         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
874         event[pos++] = event_size;
875         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
876         offset += 8;
877         pos += 8;
878         event[pos++] = packet[offset + 1 + data_length]; // rssi
879         event[pos++] = packet[offset++]; //data_length;
880         memcpy(&event[pos], &packet[offset], data_length);
881         pos += data_length;
882         offset += data_length + 1; // rssi
883         hci_emit_event(event, pos, 1);
884     }
885 }
886 #endif
887 
888 static uint32_t hci_transport_uart_get_main_baud_rate(void){
889     if (!hci_stack->config) return 0;
890     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
891     // Limit baud rate for Broadcom chipsets to 3 mbps
892     if (hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION && baud_rate > 3000000){
893         baud_rate = 3000000;
894     }
895     return baud_rate;
896 }
897 
898 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
899     switch (hci_stack->substate){
900         case HCI_INIT_W4_SEND_RESET:
901             log_info("Resend HCI Reset");
902             hci_stack->substate = HCI_INIT_SEND_RESET;
903             hci_stack->num_cmd_packets = 1;
904             hci_run();
905             break;
906         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
907             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
908             if (hci_stack->hci_transport->reset_link){
909                 hci_stack->hci_transport->reset_link();
910             }
911             // no break - explicit fallthrough to HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT
912         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
913             log_info("Resend HCI Reset - CSR Warm Boot");
914             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
915             hci_stack->num_cmd_packets = 1;
916             hci_run();
917             break;
918         case HCI_INIT_W4_SEND_BAUD_CHANGE:
919             if (hci_stack->hci_transport->set_baudrate){
920                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
921                 log_info("Local baud rate change to %"PRIu32"(timeout handler)", baud_rate);
922                 hci_stack->hci_transport->set_baudrate(baud_rate);
923             }
924             // For CSR, HCI Reset is sent on new baud rate
925             if (hci_stack->manufacturer == COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
926                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
927                 hci_run();
928             }
929             break;
930         default:
931             break;
932     }
933 }
934 
935 static void hci_initializing_next_state(void){
936     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
937 }
938 
939 // assumption: hci_can_send_command_packet_now() == true
940 static void hci_initializing_run(void){
941     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
942     switch (hci_stack->substate){
943         case HCI_INIT_SEND_RESET:
944             hci_state_reset();
945 
946 #ifndef HAVE_PLATFORM_IPHONE_OS
947             // prepare reset if command complete not received in 100ms
948             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
949             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
950             btstack_run_loop_add_timer(&hci_stack->timeout);
951 #endif
952             // send command
953             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
954             hci_send_cmd(&hci_reset);
955             break;
956         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
957             hci_send_cmd(&hci_read_local_version_information);
958             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
959             break;
960         case HCI_INIT_SEND_READ_LOCAL_NAME:
961             hci_send_cmd(&hci_read_local_name);
962             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
963             break;
964         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
965             hci_state_reset();
966             // prepare reset if command complete not received in 100ms
967             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
968             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
969             btstack_run_loop_add_timer(&hci_stack->timeout);
970             // send command
971             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
972             hci_send_cmd(&hci_reset);
973             break;
974         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
975             hci_state_reset();
976             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
977             hci_send_cmd(&hci_reset);
978             break;
979         case HCI_INIT_SEND_BAUD_CHANGE: {
980             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
981             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
982             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
983             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
984             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
985             // STLC25000D: baudrate change happens within 0.5 s after command was send,
986             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
987             if (hci_stack->manufacturer == COMPANY_ID_ST_MICROELECTRONICS){
988                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
989                 btstack_run_loop_add_timer(&hci_stack->timeout);
990             }
991             break;
992         }
993         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
994             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
995             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
996             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
997             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
998             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
999             break;
1000         }
1001         case HCI_INIT_CUSTOM_INIT:
1002             // Custom initialization
1003             if (hci_stack->chipset && hci_stack->chipset->next_command){
1004                 int valid_cmd = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1005                 if (valid_cmd){
1006                     int size = 3 + hci_stack->hci_packet_buffer[2];
1007                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1008                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1009                     switch (valid_cmd) {
1010                         case 1:
1011                         default:
1012                             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1013                             break;
1014                         case 2: // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1015                             log_info("CSR Warm Boot");
1016                             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1017                             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1018                             btstack_run_loop_add_timer(&hci_stack->timeout);
1019                             if (hci_stack->manufacturer == COMPANY_ID_CAMBRIDGE_SILICON_RADIO
1020                                 && hci_stack->config
1021                                 && hci_stack->chipset
1022                                 // && hci_stack->chipset->set_baudrate_command -- there's no such command
1023                                 && hci_stack->hci_transport->set_baudrate
1024                                 && hci_transport_uart_get_main_baud_rate()){
1025                                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1026                             } else {
1027                                hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1028                             }
1029                             break;
1030                     }
1031                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1032                     break;
1033                 }
1034                 log_info("Init script done");
1035 
1036                 // Init script download causes baud rate to reset on Broadcom chipsets, restore UART baud rate if needed
1037                 if (hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION){
1038                     int need_baud_change = hci_stack->config
1039                         && hci_stack->chipset
1040                         && hci_stack->chipset->set_baudrate_command
1041                         && hci_stack->hci_transport->set_baudrate
1042                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1043                     if (need_baud_change) {
1044                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1045                         log_info("Local baud rate change to %"PRIu32" after init script (bcm)", baud_rate);
1046                         hci_stack->hci_transport->set_baudrate(baud_rate);
1047                     }
1048                 }
1049             }
1050             // otherwise continue
1051             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1052             hci_send_cmd(&hci_read_local_supported_commands);
1053             break;
1054         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1055             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1056             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1057             hci_send_cmd(&hci_read_local_supported_commands);
1058             break;
1059         case HCI_INIT_SET_BD_ADDR:
1060             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1061             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1062             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1063             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1064             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1065             break;
1066         case HCI_INIT_READ_BD_ADDR:
1067             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1068             hci_send_cmd(&hci_read_bd_addr);
1069             break;
1070         case HCI_INIT_READ_BUFFER_SIZE:
1071             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1072             hci_send_cmd(&hci_read_buffer_size);
1073             break;
1074         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1075             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1076             hci_send_cmd(&hci_read_local_supported_features);
1077             break;
1078         case HCI_INIT_SET_EVENT_MASK:
1079             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1080             if (hci_le_supported()){
1081                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1082             } else {
1083                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1084                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1085             }
1086             break;
1087 #ifdef ENABLE_CLASSIC
1088         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1089             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1090             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1091             break;
1092         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1093             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1094             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1095             break;
1096         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1097             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1098             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1099             break;
1100         case HCI_INIT_WRITE_LOCAL_NAME:
1101             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1102             if (hci_stack->local_name){
1103                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
1104             } else {
1105                 char local_name[8+17+1];
1106                 // BTstack 11:22:33:44:55:66
1107                 memcpy(local_name, "BTstack ", 8);
1108                 memcpy(&local_name[8], bd_addr_to_str(hci_stack->local_bd_addr), 17);   // strlen(bd_addr_to_str(...)) = 17
1109                 local_name[8+17] = '\0';
1110                 log_info("---> Name %s", local_name);
1111                 hci_send_cmd(&hci_write_local_name, local_name);
1112             }
1113             break;
1114         case HCI_INIT_WRITE_EIR_DATA:
1115             hci_stack->substate = HCI_INIT_W4_WRITE_EIR_DATA;
1116             hci_send_cmd(&hci_write_extended_inquiry_response, 0, hci_stack->eir_data);
1117             break;
1118         case HCI_INIT_WRITE_INQUIRY_MODE:
1119             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1120             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1121             break;
1122         case HCI_INIT_WRITE_SCAN_ENABLE:
1123             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1124             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1125             break;
1126         // only sent if ENABLE_SCO_OVER_HCI is defined
1127         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1128             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1129             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1130             break;
1131         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1132             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1133             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1134             break;
1135 #endif
1136 #ifdef ENABLE_BLE
1137         // LE INIT
1138         case HCI_INIT_LE_READ_BUFFER_SIZE:
1139             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1140             hci_send_cmd(&hci_le_read_buffer_size);
1141             break;
1142         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1143             // LE Supported Host = 1, Simultaneous Host = 0
1144             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1145             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1146             break;
1147         case HCI_INIT_READ_WHITE_LIST_SIZE:
1148             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1149             hci_send_cmd(&hci_le_read_white_list_size);
1150             break;
1151         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1152             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
1153             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1154             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
1155             break;
1156 #endif
1157         default:
1158             return;
1159     }
1160 }
1161 
1162 static void hci_init_done(void){
1163     // done. tell the app
1164     log_info("hci_init_done -> HCI_STATE_WORKING");
1165     hci_stack->state = HCI_STATE_WORKING;
1166     hci_emit_state();
1167     hci_run();
1168 }
1169 
1170 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
1171     uint8_t command_completed = 0;
1172 
1173     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1174         uint16_t opcode = little_endian_read_16(packet,3);
1175         if (opcode == hci_stack->last_cmd_opcode){
1176             command_completed = 1;
1177             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1178         } else {
1179             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1180         }
1181     }
1182 
1183     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1184         uint8_t  status = packet[2];
1185         uint16_t opcode = little_endian_read_16(packet,4);
1186         if (opcode == hci_stack->last_cmd_opcode){
1187             if (status){
1188                 command_completed = 1;
1189                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1190             } else {
1191                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1192             }
1193         } else {
1194             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1195         }
1196     }
1197 
1198     // Vendor == CSR
1199     if (hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT && hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC){
1200         // TODO: track actual command
1201         command_completed = 1;
1202     }
1203 
1204     // Vendor == Toshiba
1205     if (hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE && hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC){
1206         // TODO: track actual command
1207         command_completed = 1;
1208     }
1209 
1210     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1211     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1212     //
1213     // HCI Reset
1214     // Timeout 100 ms
1215     // HCI Reset
1216     // Command Complete Reset
1217     // HCI Read Local Version Information
1218     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1219     // hang...
1220     //
1221     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1222     if (!command_completed
1223             && hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE
1224             && hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION){
1225 
1226         uint16_t opcode = little_endian_read_16(packet,3);
1227         if (opcode == hci_reset.opcode){
1228             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1229             return;
1230         }
1231     }
1232 
1233     // CSR & H5
1234     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1235     if (!command_completed
1236             && hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE
1237             && hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS){
1238 
1239         uint16_t opcode = little_endian_read_16(packet,3);
1240         if (opcode == hci_reset.opcode){
1241             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1242             return;
1243         }
1244     }
1245 
1246     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1247     // fix: Correct substate and behave as command below
1248     if (command_completed){
1249         switch (hci_stack->substate){
1250             case HCI_INIT_SEND_RESET:
1251                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1252                 break;
1253             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1254                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1255                 break;
1256             default:
1257                 break;
1258         }
1259     }
1260 
1261 
1262     if (!command_completed) return;
1263 
1264     int need_baud_change = hci_stack->config
1265                         && hci_stack->chipset
1266                         && hci_stack->chipset->set_baudrate_command
1267                         && hci_stack->hci_transport->set_baudrate
1268                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1269 
1270     int need_addr_change = hci_stack->custom_bd_addr_set
1271                         && hci_stack->chipset
1272                         && hci_stack->chipset->set_bd_addr_command;
1273 
1274     switch(hci_stack->substate){
1275         case HCI_INIT_SEND_RESET:
1276             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1277             // fix: just correct substate and behave as command below
1278             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1279             btstack_run_loop_remove_timer(&hci_stack->timeout);
1280             break;
1281         case HCI_INIT_W4_SEND_RESET:
1282             btstack_run_loop_remove_timer(&hci_stack->timeout);
1283             break;
1284         case HCI_INIT_W4_SEND_READ_LOCAL_NAME:
1285             log_info("Received local name, need baud change %d", need_baud_change);
1286             if (need_baud_change){
1287                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1288                 return;
1289             }
1290             // skip baud change
1291             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1292             return;
1293         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1294             // for STLC2500D, baud rate change already happened.
1295             // for others, baud rate gets changed now
1296             if ((hci_stack->manufacturer != COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1297                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1298                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change)", baud_rate);
1299                 hci_stack->hci_transport->set_baudrate(baud_rate);
1300             }
1301             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1302             return;
1303         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1304             btstack_run_loop_remove_timer(&hci_stack->timeout);
1305             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1306             return;
1307         case HCI_INIT_W4_CUSTOM_INIT:
1308             // repeat custom init
1309             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1310             return;
1311         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1312             if (need_baud_change && hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION){
1313                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1314                 return;
1315             }
1316             if (need_addr_change){
1317                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1318                 return;
1319             }
1320             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1321             return;
1322         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1323             if (need_baud_change){
1324                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1325                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change_bcm))", baud_rate);
1326                 hci_stack->hci_transport->set_baudrate(baud_rate);
1327             }
1328             if (need_addr_change){
1329                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1330                 return;
1331             }
1332             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1333             return;
1334         case HCI_INIT_W4_SET_BD_ADDR:
1335             // for STLC2500D, bd addr change only gets active after sending reset command
1336             if (hci_stack->manufacturer == COMPANY_ID_ST_MICROELECTRONICS){
1337                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1338                 return;
1339             }
1340             // skipping st warm boot
1341             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1342             return;
1343         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1344             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1345             return;
1346         case HCI_INIT_W4_READ_BD_ADDR:
1347             // only read buffer size if supported
1348             if (hci_stack->local_supported_commands[0] & 0x01) {
1349                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1350                 return;
1351             }
1352             // skipping read buffer size
1353             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1354             return;
1355         case HCI_INIT_W4_SET_EVENT_MASK:
1356             // skip Classic init commands for LE only chipsets
1357             if (!hci_classic_supported()){
1358                 if (hci_le_supported()){
1359                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1360                     return;
1361                 } else {
1362                     log_error("Neither BR/EDR nor LE supported");
1363                     hci_init_done();
1364                     return;
1365                 }
1366             }
1367             if (!gap_ssp_supported()){
1368                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1369                 return;
1370             }
1371             break;
1372         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1373             // skip write le host if not supported (e.g. on LE only EM9301)
1374             if (hci_stack->local_supported_commands[0] & 0x02) break;
1375             hci_stack->substate = HCI_INIT_LE_SET_SCAN_PARAMETERS;
1376             return;
1377         case HCI_INIT_W4_WRITE_LOCAL_NAME:
1378             // skip write eir data if no eir data set
1379             if (hci_stack->eir_data) break;
1380             hci_stack->substate = HCI_INIT_WRITE_INQUIRY_MODE;
1381             return;
1382 
1383 #ifdef ENABLE_SCO_OVER_HCI
1384         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1385             // skip write synchronous flow control if not supported
1386             if (hci_stack->local_supported_commands[0] & 0x04) break;
1387             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1388             // explicit fall through to reduce repetitions
1389 
1390         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1391             // skip write default erroneous data reporting if not supported
1392             if (hci_stack->local_supported_commands[0] & 0x08) break;
1393             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1394             // explicit fall through to reduce repetitions
1395 
1396         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1397             if (!hci_le_supported()){
1398                 // SKIP LE init for Classic only configuration
1399                 hci_init_done();
1400                 return;
1401             }
1402             break;
1403 #else
1404         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1405             if (!hci_le_supported()){
1406                 // SKIP LE init for Classic only configuration
1407                 hci_init_done();
1408                 return;
1409             }
1410 #endif
1411             break;
1412         // Response to command before init done state -> init done
1413         case (HCI_INIT_DONE-1):
1414             hci_init_done();
1415             return;
1416 
1417         default:
1418             break;
1419     }
1420     hci_initializing_next_state();
1421 }
1422 
1423 static void event_handler(uint8_t *packet, int size){
1424 
1425     uint16_t event_length = packet[1];
1426 
1427     // assert packet is complete
1428     if (size != event_length + 2){
1429         log_error("hci.c: event_handler called with event packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
1430         return;
1431     }
1432 
1433     bd_addr_t addr;
1434     bd_addr_type_t addr_type;
1435     uint8_t link_type;
1436     hci_con_handle_t handle;
1437     hci_connection_t * conn;
1438     int i;
1439 
1440     // warnings
1441     (void) link_type;
1442 
1443     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
1444 
1445     switch (hci_event_packet_get_type(packet)) {
1446 
1447         case HCI_EVENT_COMMAND_COMPLETE:
1448             // get num cmd packets
1449             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
1450             hci_stack->num_cmd_packets = packet[2];
1451 
1452             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_buffer_size)){
1453                 // from offset 5
1454                 // status
1455                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
1456                 hci_stack->acl_data_packet_length = little_endian_read_16(packet, 6);
1457                 hci_stack->sco_data_packet_length = packet[8];
1458                 hci_stack->acl_packets_total_num  = little_endian_read_16(packet, 9);
1459                 hci_stack->sco_packets_total_num  = little_endian_read_16(packet, 11);
1460 
1461                 if (hci_stack->state == HCI_STATE_INITIALIZING){
1462                     // determine usable ACL payload size
1463                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
1464                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1465                     }
1466                     log_info("hci_read_buffer_size: acl used size %u, count %u / sco size %u, count %u",
1467                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
1468                              hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
1469                 }
1470             }
1471 #ifdef ENABLE_BLE
1472             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_buffer_size)){
1473                 hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
1474                 hci_stack->le_acl_packets_total_num  = packet[8];
1475                     // determine usable ACL payload size
1476                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1477                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1478                     }
1479                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1480             }
1481             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_white_list_size)){
1482                 hci_stack->le_whitelist_capacity = little_endian_read_16(packet, 6);
1483                 log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
1484             }
1485 #endif
1486             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)) {
1487                 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1],
1488 				hci_stack->local_bd_addr);
1489                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1490                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1491 #ifdef ENABLE_CLASSIC
1492                 if (hci_stack->link_key_db){
1493                     hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
1494                 }
1495 #endif
1496             }
1497 #ifdef ENABLE_CLASSIC
1498             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
1499                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1500             }
1501 #endif
1502 
1503             // Note: HCI init checks
1504             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_features)){
1505                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1506 
1507 #ifdef ENABLE_CLASSIC
1508                 // determine usable ACL packet types based on host buffer size and supported features
1509                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1510                 log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
1511 #endif
1512                 // Classic/LE
1513                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1514             }
1515             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_version_information)){
1516                 // hci_stack->hci_version    = little_endian_read_16(packet, 4);
1517                 // hci_stack->hci_revision   = little_endian_read_16(packet, 6);
1518                 // hci_stack->lmp_version    = little_endian_read_16(packet, 8);
1519                 hci_stack->manufacturer   = little_endian_read_16(packet, 10);
1520                 // hci_stack->lmp_subversion = little_endian_read_16(packet, 12);
1521                 log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
1522                 // notify app
1523                 if (hci_stack->local_version_information_callback){
1524                     hci_stack->local_version_information_callback(packet);
1525                 }
1526             }
1527             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){
1528                 hci_stack->local_supported_commands[0] =
1529                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+14] & 0x80) >> 7 |  // bit 0 = Octet 14, bit 7
1530                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+24] & 0x40) >> 5 |  // bit 1 = Octet 24, bit 6
1531                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+10] & 0x10) >> 2 |  // bit 2 = Octet 10, bit 4
1532                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+18] & 0x08);        // bit 3 = Octet 18, bit 3
1533                     log_info("Local supported commands summary 0x%02x", hci_stack->local_supported_commands[0]);
1534             }
1535             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_synchronous_flow_control_enable)){
1536                 if (packet[5] == 0){
1537                     hci_stack->synchronous_flow_control_enabled = 1;
1538                 }
1539             }
1540             break;
1541 
1542         case HCI_EVENT_COMMAND_STATUS:
1543             // get num cmd packets
1544             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1545             hci_stack->num_cmd_packets = packet[3];
1546             break;
1547 
1548         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1549             int offset = 3;
1550             for (i=0; i<packet[2];i++){
1551                 handle = little_endian_read_16(packet, offset);
1552                 offset += 2;
1553                 uint16_t num_packets = little_endian_read_16(packet, offset);
1554                 offset += 2;
1555 
1556                 conn = hci_connection_for_handle(handle);
1557                 if (!conn){
1558                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1559                     continue;
1560                 }
1561 
1562                 if (conn->address_type == BD_ADDR_TYPE_SCO){
1563 #ifdef ENABLE_CLASSIC
1564                     if (conn->num_sco_packets_sent >= num_packets){
1565                         conn->num_sco_packets_sent -= num_packets;
1566                     } else {
1567                         log_error("hci_number_completed_packets, more sco slots freed then sent.");
1568                         conn->num_sco_packets_sent = 0;
1569                     }
1570                     hci_notify_if_sco_can_send_now();
1571 #endif
1572                 } else {
1573                     if (conn->num_acl_packets_sent >= num_packets){
1574                         conn->num_acl_packets_sent -= num_packets;
1575                     } else {
1576                         log_error("hci_number_completed_packets, more acl slots freed then sent.");
1577                         conn->num_acl_packets_sent = 0;
1578                     }
1579                 }
1580                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1581             }
1582             break;
1583         }
1584 
1585 #ifdef ENABLE_CLASSIC
1586         case HCI_EVENT_CONNECTION_REQUEST:
1587             reverse_bd_addr(&packet[2], addr);
1588             // TODO: eval COD 8-10
1589             link_type = packet[11];
1590             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1591             addr_type = link_type == 1 ? BD_ADDR_TYPE_CLASSIC : BD_ADDR_TYPE_SCO;
1592             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1593             if (!conn) {
1594                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1595             }
1596             if (!conn) {
1597                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1598                 hci_stack->decline_reason = 0x0d;
1599                 bd_addr_copy(hci_stack->decline_addr, addr);
1600                 break;
1601             }
1602             conn->role  = HCI_ROLE_SLAVE;
1603             conn->state = RECEIVED_CONNECTION_REQUEST;
1604             // store info about eSCO
1605             if (link_type == 0x02){
1606                 conn->remote_supported_feature_eSCO = 1;
1607             }
1608             hci_run();
1609             break;
1610 
1611         case HCI_EVENT_CONNECTION_COMPLETE:
1612             // Connection management
1613             reverse_bd_addr(&packet[5], addr);
1614             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1615             addr_type = BD_ADDR_TYPE_CLASSIC;
1616             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1617             if (conn) {
1618                 if (!packet[2]){
1619                     conn->state = OPEN;
1620                     conn->con_handle = little_endian_read_16(packet, 3);
1621                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1622 
1623                     // restart timer
1624                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1625                     btstack_run_loop_add_timer(&conn->timeout);
1626 
1627                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1628 
1629                     hci_emit_nr_connections_changed();
1630                 } else {
1631                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1632                     uint8_t status = packet[2];
1633                     bd_addr_t bd_address;
1634                     memcpy(&bd_address, conn->address, 6);
1635 
1636                     // connection failed, remove entry
1637                     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1638                     btstack_memory_hci_connection_free( conn );
1639 
1640                     // notify client if dedicated bonding
1641                     if (notify_dedicated_bonding_failed){
1642                         log_info("hci notify_dedicated_bonding_failed");
1643                         hci_emit_dedicated_bonding_result(bd_address, status);
1644                     }
1645 
1646                     // if authentication error, also delete link key
1647                     if (packet[2] == 0x05) {
1648                         gap_drop_link_key_for_bd_addr(addr);
1649                     }
1650                 }
1651             }
1652             break;
1653 
1654         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
1655             reverse_bd_addr(&packet[5], addr);
1656             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1657             if (packet[2]){
1658                 // connection failed
1659                 break;
1660             }
1661             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1662             if (!conn) {
1663                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1664             }
1665             if (!conn) {
1666                 break;
1667             }
1668             conn->state = OPEN;
1669             conn->con_handle = little_endian_read_16(packet, 3);
1670             break;
1671 
1672         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1673             handle = little_endian_read_16(packet, 3);
1674             conn = hci_connection_for_handle(handle);
1675             if (!conn) break;
1676             if (!packet[2]){
1677                 uint8_t * features = &packet[5];
1678                 if (features[6] & (1 << 3)){
1679                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1680                 }
1681                 if (features[3] & (1<<7)){
1682                     conn->remote_supported_feature_eSCO = 1;
1683                 }
1684             }
1685             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1686             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x, eSCO %u", conn->bonding_flags, conn->remote_supported_feature_eSCO);
1687             if (conn->bonding_flags & BONDING_DEDICATED){
1688                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1689             }
1690             break;
1691 
1692         case HCI_EVENT_LINK_KEY_REQUEST:
1693             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1694             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1695             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1696             if (hci_stack->bondable && !hci_stack->link_key_db) break;
1697             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1698             hci_run();
1699             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1700             return;
1701 
1702         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1703             reverse_bd_addr(&packet[2], addr);
1704             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1705             if (!conn) break;
1706             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1707             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1708             // Change Connection Encryption keeps link key type
1709             if (link_key_type != CHANGED_COMBINATION_KEY){
1710                 conn->link_key_type = link_key_type;
1711             }
1712             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
1713             // still forward event to allow dismiss of pairing dialog
1714             break;
1715         }
1716 
1717         case HCI_EVENT_PIN_CODE_REQUEST:
1718             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1719             // non-bondable mode: pin code negative reply will be sent
1720             if (!hci_stack->bondable){
1721                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1722                 hci_run();
1723                 return;
1724             }
1725             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1726             if (!hci_stack->link_key_db) break;
1727             hci_event_pin_code_request_get_bd_addr(packet, addr);
1728             hci_stack->link_key_db->delete_link_key(addr);
1729             break;
1730 
1731         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1732             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1733             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1734             break;
1735 
1736         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1737             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1738             if (!hci_stack->ssp_auto_accept) break;
1739             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1740             break;
1741 
1742         case HCI_EVENT_USER_PASSKEY_REQUEST:
1743             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1744             if (!hci_stack->ssp_auto_accept) break;
1745             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1746             break;
1747 #endif
1748 
1749         case HCI_EVENT_ENCRYPTION_CHANGE:
1750             handle = little_endian_read_16(packet, 3);
1751             conn = hci_connection_for_handle(handle);
1752             if (!conn) break;
1753             if (packet[2] == 0) {
1754                 if (packet[5]){
1755                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1756                 } else {
1757                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1758                 }
1759             }
1760 #ifdef ENABLE_CLASSIC
1761             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1762 #endif
1763             break;
1764 
1765 #ifdef ENABLE_CLASSIC
1766         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1767             handle = little_endian_read_16(packet, 3);
1768             conn = hci_connection_for_handle(handle);
1769             if (!conn) break;
1770 
1771             // dedicated bonding: send result and disconnect
1772             if (conn->bonding_flags & BONDING_DEDICATED){
1773                 conn->bonding_flags &= ~BONDING_DEDICATED;
1774                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1775                 conn->bonding_status = packet[2];
1776                 break;
1777             }
1778 
1779             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1780                 // link key sufficient for requested security
1781                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1782                 break;
1783             }
1784             // not enough
1785             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1786             break;
1787 #endif
1788 
1789         // HCI_EVENT_DISCONNECTION_COMPLETE
1790         // has been split, to first notify stack before shutting connection down
1791         // see end of function, too.
1792         case HCI_EVENT_DISCONNECTION_COMPLETE:
1793             if (packet[2]) break;   // status != 0
1794             handle = little_endian_read_16(packet, 3);
1795             // drop outgoing ACL fragments if it is for closed connection
1796             if (hci_stack->acl_fragmentation_total_size > 0) {
1797                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
1798                     log_info("hci: drop fragmented ACL data for closed connection");
1799                      hci_stack->acl_fragmentation_total_size = 0;
1800                      hci_stack->acl_fragmentation_pos = 0;
1801                 }
1802             }
1803 
1804             // re-enable advertisements for le connections if active
1805             conn = hci_connection_for_handle(handle);
1806             if (!conn) break;
1807 #ifdef ENABLE_BLE
1808             if (hci_is_le_connection(conn) && hci_stack->le_advertisements_enabled){
1809                 hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
1810             }
1811 #endif
1812             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1813             break;
1814 
1815         case HCI_EVENT_HARDWARE_ERROR:
1816             log_error("Hardware Error: 0x%02x", packet[2]);
1817             if (hci_stack->hardware_error_callback){
1818                 (*hci_stack->hardware_error_callback)(packet[2]);
1819             } else {
1820                 // if no special requests, just reboot stack
1821                 hci_power_control_off();
1822                 hci_power_control_on();
1823             }
1824             break;
1825 
1826         case HCI_EVENT_ROLE_CHANGE:
1827             if (packet[2]) break;   // status != 0
1828             handle = little_endian_read_16(packet, 3);
1829             conn = hci_connection_for_handle(handle);
1830             if (!conn) break;       // no conn
1831             conn->role = packet[9];
1832             break;
1833 
1834         case HCI_EVENT_TRANSPORT_PACKET_SENT:
1835             // release packet buffer only for asynchronous transport and if there are not further fragements
1836             if (hci_transport_synchronous()) {
1837                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
1838                 return; // instead of break: to avoid re-entering hci_run()
1839             }
1840             if (hci_stack->acl_fragmentation_total_size) break;
1841             hci_release_packet_buffer();
1842 
1843             // L2CAP receives this event via the hci_emit_event below
1844 
1845 #ifdef ENABLE_CLASSIC
1846             // For SCO, we do the can_send_now_check here
1847             hci_notify_if_sco_can_send_now();
1848 #endif
1849             break;
1850 
1851 #ifdef ENABLE_CLASSIC
1852         case HCI_EVENT_SCO_CAN_SEND_NOW:
1853             // For SCO, we do the can_send_now_check here
1854             hci_notify_if_sco_can_send_now();
1855             return;
1856 #endif
1857 
1858 #ifdef ENABLE_BLE
1859         case HCI_EVENT_LE_META:
1860             switch (packet[2]){
1861                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1862                     // log_info("advertising report received");
1863                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1864                     le_handle_advertisement_report(packet, size);
1865                     break;
1866                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1867                     // Connection management
1868                     reverse_bd_addr(&packet[8], addr);
1869                     addr_type = (bd_addr_type_t)packet[7];
1870                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1871                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1872                     // if auto-connect, remove from whitelist in both roles
1873                     if (hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST){
1874                         hci_remove_from_whitelist(addr_type, addr);
1875                     }
1876                     // handle error: error is reported only to the initiator -> outgoing connection
1877                     if (packet[3]){
1878                         // outgoing connection establishment is done
1879                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1880                         // remove entry
1881                         if (conn){
1882                             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1883                             btstack_memory_hci_connection_free( conn );
1884                         }
1885                         break;
1886                     }
1887                     // on success, both hosts receive connection complete event
1888                     if (packet[6] == HCI_ROLE_MASTER){
1889                         // if we're master, it was an outgoing connection and we're done with it
1890                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1891                     } else {
1892                         // if we're slave, it was an incoming connection, advertisements have stopped
1893                         hci_stack->le_advertisements_active = 0;
1894                     }
1895                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1896                     if (!conn){
1897                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1898                     }
1899                     // no memory, sorry.
1900                     if (!conn){
1901                         break;
1902                     }
1903 
1904                     conn->state = OPEN;
1905                     conn->role  = packet[6];
1906                     conn->con_handle = little_endian_read_16(packet, 4);
1907 
1908                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1909 
1910                     // restart timer
1911                     // btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1912                     // btstack_run_loop_add_timer(&conn->timeout);
1913 
1914                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1915 
1916                     hci_emit_nr_connections_changed();
1917                     break;
1918 
1919             // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
1920 
1921                 default:
1922                     break;
1923             }
1924             break;
1925 #endif
1926         default:
1927             break;
1928     }
1929 
1930     // handle BT initialization
1931     if (hci_stack->state == HCI_STATE_INITIALIZING){
1932         hci_initializing_event_handler(packet, size);
1933     }
1934 
1935     // help with BT sleep
1936     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1937         && hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE
1938         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
1939         hci_initializing_next_state();
1940     }
1941 
1942     // notify upper stack
1943 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
1944 
1945     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1946     if (hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE){
1947         if (!packet[2]){
1948             handle = little_endian_read_16(packet, 3);
1949             hci_connection_t * aConn = hci_connection_for_handle(handle);
1950             if (aConn) {
1951                 uint8_t status = aConn->bonding_status;
1952                 uint16_t flags = aConn->bonding_flags;
1953                 bd_addr_t bd_address;
1954                 memcpy(&bd_address, aConn->address, 6);
1955                 hci_shutdown_connection(aConn);
1956                 // connection struct is gone, don't access anymore
1957                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1958                     hci_emit_dedicated_bonding_result(bd_address, status);
1959                 }
1960             }
1961         }
1962     }
1963 
1964 	// execute main loop
1965 	hci_run();
1966 }
1967 
1968 #ifdef ENABLE_CLASSIC
1969 static void sco_handler(uint8_t * packet, uint16_t size){
1970     if (!hci_stack->sco_packet_handler) return;
1971     hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
1972 }
1973 #endif
1974 
1975 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1976     hci_dump_packet(packet_type, 1, packet, size);
1977     switch (packet_type) {
1978         case HCI_EVENT_PACKET:
1979             event_handler(packet, size);
1980             break;
1981         case HCI_ACL_DATA_PACKET:
1982             acl_handler(packet, size);
1983             break;
1984 #ifdef ENABLE_CLASSIC
1985         case HCI_SCO_DATA_PACKET:
1986             sco_handler(packet, size);
1987             break;
1988 #endif
1989         default:
1990             break;
1991     }
1992 }
1993 
1994 /**
1995  * @brief Add event packet handler.
1996  */
1997 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
1998     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
1999 }
2000 
2001 
2002 /** Register HCI packet handlers */
2003 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
2004     hci_stack->acl_packet_handler = handler;
2005 }
2006 
2007 #ifdef ENABLE_CLASSIC
2008 /**
2009  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
2010  */
2011 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
2012     hci_stack->sco_packet_handler = handler;
2013 }
2014 #endif
2015 
2016 static void hci_state_reset(void){
2017     // no connections yet
2018     hci_stack->connections = NULL;
2019 
2020     // keep discoverable/connectable as this has been requested by the client(s)
2021     // hci_stack->discoverable = 0;
2022     // hci_stack->connectable = 0;
2023     // hci_stack->bondable = 1;
2024 
2025     // buffer is free
2026     hci_stack->hci_packet_buffer_reserved = 0;
2027 
2028     // no pending cmds
2029     hci_stack->decline_reason = 0;
2030     hci_stack->new_scan_enable_value = 0xff;
2031 
2032     // LE
2033     hci_stack->adv_addr_type = 0;
2034     hci_stack->le_advertisements_random_address_set = 0;
2035     memset(hci_stack->adv_address, 0, 6);
2036     hci_stack->le_scanning_state = LE_SCAN_IDLE;
2037     hci_stack->le_scan_type = 0xff;
2038     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2039     hci_stack->le_whitelist = 0;
2040     hci_stack->le_whitelist_capacity = 0;
2041     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
2042     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
2043     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
2044     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
2045     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
2046     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
2047 }
2048 
2049 #ifdef ENABLE_CLASSIC
2050 /**
2051  * @brief Configure Bluetooth hardware control. Has to be called before power on.
2052  */
2053 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
2054     // store and open remote device db
2055     hci_stack->link_key_db = link_key_db;
2056     if (hci_stack->link_key_db) {
2057         hci_stack->link_key_db->open();
2058     }
2059 }
2060 #endif
2061 
2062 void hci_init(const hci_transport_t *transport, const void *config){
2063 
2064 #ifdef HAVE_MALLOC
2065     if (!hci_stack) {
2066         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
2067     }
2068 #else
2069     hci_stack = &hci_stack_static;
2070 #endif
2071     memset(hci_stack, 0, sizeof(hci_stack_t));
2072 
2073     // reference to use transport layer implementation
2074     hci_stack->hci_transport = transport;
2075 
2076     // reference to used config
2077     hci_stack->config = config;
2078 
2079     // setup pointer for outgoing packet buffer
2080     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
2081 
2082     // max acl payload size defined in config.h
2083     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
2084 
2085     // register packet handlers with transport
2086     transport->register_packet_handler(&packet_handler);
2087 
2088     hci_stack->state = HCI_STATE_OFF;
2089 
2090     // class of device
2091     hci_stack->class_of_device = 0x007a020c; // Smartphone
2092 
2093     // bondable by default
2094     hci_stack->bondable = 1;
2095 
2096     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
2097     hci_stack->ssp_enable = 1;
2098     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
2099     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
2100     hci_stack->ssp_auto_accept = 1;
2101 
2102     // voice setting - signed 8 bit pcm data with CVSD over the air
2103     hci_stack->sco_voice_setting = 0x40;
2104 
2105     hci_state_reset();
2106 }
2107 
2108 /**
2109  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
2110  */
2111 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
2112     hci_stack->chipset = chipset_driver;
2113 
2114     // reset chipset driver - init is also called on power_up
2115     if (hci_stack->chipset && hci_stack->chipset->init){
2116         hci_stack->chipset->init(hci_stack->config);
2117     }
2118 }
2119 
2120 /**
2121  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
2122  */
2123 void hci_set_control(const btstack_control_t *hardware_control){
2124     // references to used control implementation
2125     hci_stack->control = hardware_control;
2126     // init with transport config
2127     hardware_control->init(hci_stack->config);
2128 }
2129 
2130 void hci_close(void){
2131     // close remote device db
2132     if (hci_stack->link_key_db) {
2133         hci_stack->link_key_db->close();
2134     }
2135 
2136     btstack_linked_list_iterator_t lit;
2137     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
2138     while (btstack_linked_list_iterator_has_next(&lit)){
2139         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
2140         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
2141         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
2142         hci_shutdown_connection(connection);
2143     }
2144 
2145     hci_power_control(HCI_POWER_OFF);
2146 
2147 #ifdef HAVE_MALLOC
2148     free(hci_stack);
2149 #endif
2150     hci_stack = NULL;
2151 }
2152 
2153 #ifdef ENABLE_CLASSIC
2154 void gap_set_class_of_device(uint32_t class_of_device){
2155     hci_stack->class_of_device = class_of_device;
2156 }
2157 #endif
2158 
2159 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
2160 void hci_set_bd_addr(bd_addr_t addr){
2161     memcpy(hci_stack->custom_bd_addr, addr, 6);
2162     hci_stack->custom_bd_addr_set = 1;
2163 }
2164 
2165 void hci_disable_l2cap_timeout_check(void){
2166     disable_l2cap_timeouts = 1;
2167 }
2168 // State-Module-Driver overview
2169 // state                    module  low-level
2170 // HCI_STATE_OFF             off      close
2171 // HCI_STATE_INITIALIZING,   on       open
2172 // HCI_STATE_WORKING,        on       open
2173 // HCI_STATE_HALTING,        on       open
2174 // HCI_STATE_SLEEPING,    off/sleep   close
2175 // HCI_STATE_FALLING_ASLEEP  on       open
2176 
2177 static int hci_power_control_on(void){
2178 
2179     // power on
2180     int err = 0;
2181     if (hci_stack->control && hci_stack->control->on){
2182         err = (*hci_stack->control->on)();
2183     }
2184     if (err){
2185         log_error( "POWER_ON failed");
2186         hci_emit_hci_open_failed();
2187         return err;
2188     }
2189 
2190     // int chipset driver
2191     if (hci_stack->chipset && hci_stack->chipset->init){
2192         hci_stack->chipset->init(hci_stack->config);
2193     }
2194 
2195     // init transport
2196     if (hci_stack->hci_transport->init){
2197         hci_stack->hci_transport->init(hci_stack->config);
2198     }
2199 
2200     // open transport
2201     err = hci_stack->hci_transport->open();
2202     if (err){
2203         log_error( "HCI_INIT failed, turning Bluetooth off again");
2204         if (hci_stack->control && hci_stack->control->off){
2205             (*hci_stack->control->off)();
2206         }
2207         hci_emit_hci_open_failed();
2208         return err;
2209     }
2210     return 0;
2211 }
2212 
2213 static void hci_power_control_off(void){
2214 
2215     log_info("hci_power_control_off");
2216 
2217     // close low-level device
2218     hci_stack->hci_transport->close();
2219 
2220     log_info("hci_power_control_off - hci_transport closed");
2221 
2222     // power off
2223     if (hci_stack->control && hci_stack->control->off){
2224         (*hci_stack->control->off)();
2225     }
2226 
2227     log_info("hci_power_control_off - control closed");
2228 
2229     hci_stack->state = HCI_STATE_OFF;
2230 }
2231 
2232 static void hci_power_control_sleep(void){
2233 
2234     log_info("hci_power_control_sleep");
2235 
2236 #if 0
2237     // don't close serial port during sleep
2238 
2239     // close low-level device
2240     hci_stack->hci_transport->close(hci_stack->config);
2241 #endif
2242 
2243     // sleep mode
2244     if (hci_stack->control && hci_stack->control->sleep){
2245         (*hci_stack->control->sleep)();
2246     }
2247 
2248     hci_stack->state = HCI_STATE_SLEEPING;
2249 }
2250 
2251 static int hci_power_control_wake(void){
2252 
2253     log_info("hci_power_control_wake");
2254 
2255     // wake on
2256     if (hci_stack->control && hci_stack->control->wake){
2257         (*hci_stack->control->wake)();
2258     }
2259 
2260 #if 0
2261     // open low-level device
2262     int err = hci_stack->hci_transport->open(hci_stack->config);
2263     if (err){
2264         log_error( "HCI_INIT failed, turning Bluetooth off again");
2265         if (hci_stack->control && hci_stack->control->off){
2266             (*hci_stack->control->off)();
2267         }
2268         hci_emit_hci_open_failed();
2269         return err;
2270     }
2271 #endif
2272 
2273     return 0;
2274 }
2275 
2276 static void hci_power_transition_to_initializing(void){
2277     // set up state machine
2278     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
2279     hci_stack->hci_packet_buffer_reserved = 0;
2280     hci_stack->state = HCI_STATE_INITIALIZING;
2281     hci_stack->substate = HCI_INIT_SEND_RESET;
2282 }
2283 
2284 int hci_power_control(HCI_POWER_MODE power_mode){
2285 
2286     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
2287 
2288     int err = 0;
2289     switch (hci_stack->state){
2290 
2291         case HCI_STATE_OFF:
2292             switch (power_mode){
2293                 case HCI_POWER_ON:
2294                     err = hci_power_control_on();
2295                     if (err) {
2296                         log_error("hci_power_control_on() error %d", err);
2297                         return err;
2298                     }
2299                     hci_power_transition_to_initializing();
2300                     break;
2301                 case HCI_POWER_OFF:
2302                     // do nothing
2303                     break;
2304                 case HCI_POWER_SLEEP:
2305                     // do nothing (with SLEEP == OFF)
2306                     break;
2307             }
2308             break;
2309 
2310         case HCI_STATE_INITIALIZING:
2311             switch (power_mode){
2312                 case HCI_POWER_ON:
2313                     // do nothing
2314                     break;
2315                 case HCI_POWER_OFF:
2316                     // no connections yet, just turn it off
2317                     hci_power_control_off();
2318                     break;
2319                 case HCI_POWER_SLEEP:
2320                     // no connections yet, just turn it off
2321                     hci_power_control_sleep();
2322                     break;
2323             }
2324             break;
2325 
2326         case HCI_STATE_WORKING:
2327             switch (power_mode){
2328                 case HCI_POWER_ON:
2329                     // do nothing
2330                     break;
2331                 case HCI_POWER_OFF:
2332                     // see hci_run
2333                     hci_stack->state = HCI_STATE_HALTING;
2334                     break;
2335                 case HCI_POWER_SLEEP:
2336                     // see hci_run
2337                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
2338                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
2339                     break;
2340             }
2341             break;
2342 
2343         case HCI_STATE_HALTING:
2344             switch (power_mode){
2345                 case HCI_POWER_ON:
2346                     hci_power_transition_to_initializing();
2347                     break;
2348                 case HCI_POWER_OFF:
2349                     // do nothing
2350                     break;
2351                 case HCI_POWER_SLEEP:
2352                     // see hci_run
2353                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
2354                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
2355                     break;
2356             }
2357             break;
2358 
2359         case HCI_STATE_FALLING_ASLEEP:
2360             switch (power_mode){
2361                 case HCI_POWER_ON:
2362 
2363 #ifdef HAVE_PLATFORM_IPHONE_OS
2364                     // nothing to do, if H4 supports power management
2365                     if (btstack_control_iphone_power_management_enabled()){
2366                         hci_stack->state = HCI_STATE_INITIALIZING;
2367                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
2368                         break;
2369                     }
2370 #endif
2371                     hci_power_transition_to_initializing();
2372                     break;
2373                 case HCI_POWER_OFF:
2374                     // see hci_run
2375                     hci_stack->state = HCI_STATE_HALTING;
2376                     break;
2377                 case HCI_POWER_SLEEP:
2378                     // do nothing
2379                     break;
2380             }
2381             break;
2382 
2383         case HCI_STATE_SLEEPING:
2384             switch (power_mode){
2385                 case HCI_POWER_ON:
2386 
2387 #ifdef HAVE_PLATFORM_IPHONE_OS
2388                     // nothing to do, if H4 supports power management
2389                     if (btstack_control_iphone_power_management_enabled()){
2390                         hci_stack->state = HCI_STATE_INITIALIZING;
2391                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
2392                         hci_update_scan_enable();
2393                         break;
2394                     }
2395 #endif
2396                     err = hci_power_control_wake();
2397                     if (err) return err;
2398                     hci_power_transition_to_initializing();
2399                     break;
2400                 case HCI_POWER_OFF:
2401                     hci_stack->state = HCI_STATE_HALTING;
2402                     break;
2403                 case HCI_POWER_SLEEP:
2404                     // do nothing
2405                     break;
2406             }
2407             break;
2408     }
2409 
2410     // create internal event
2411 	hci_emit_state();
2412 
2413 	// trigger next/first action
2414 	hci_run();
2415 
2416     return 0;
2417 }
2418 
2419 
2420 #ifdef ENABLE_CLASSIC
2421 
2422 static void hci_update_scan_enable(void){
2423     // 2 = page scan, 1 = inq scan
2424     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
2425     hci_run();
2426 }
2427 
2428 void gap_discoverable_control(uint8_t enable){
2429     if (enable) enable = 1; // normalize argument
2430 
2431     if (hci_stack->discoverable == enable){
2432         hci_emit_discoverable_enabled(hci_stack->discoverable);
2433         return;
2434     }
2435 
2436     hci_stack->discoverable = enable;
2437     hci_update_scan_enable();
2438 }
2439 
2440 void gap_connectable_control(uint8_t enable){
2441     if (enable) enable = 1; // normalize argument
2442 
2443     // don't emit event
2444     if (hci_stack->connectable == enable) return;
2445 
2446     hci_stack->connectable = enable;
2447     hci_update_scan_enable();
2448 }
2449 #endif
2450 
2451 void gap_local_bd_addr(bd_addr_t address_buffer){
2452     memcpy(address_buffer, hci_stack->local_bd_addr, 6);
2453 }
2454 
2455 static void hci_run(void){
2456 
2457     // log_info("hci_run: entered");
2458     btstack_linked_item_t * it;
2459 
2460     // send continuation fragments first, as they block the prepared packet buffer
2461     if (hci_stack->acl_fragmentation_total_size > 0) {
2462         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
2463         hci_connection_t *connection = hci_connection_for_handle(con_handle);
2464         if (connection) {
2465             if (hci_can_send_prepared_acl_packet_now(con_handle)){
2466                 hci_send_acl_packet_fragments(connection);
2467                 return;
2468             }
2469         } else {
2470             // connection gone -> discard further fragments
2471             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
2472             hci_stack->acl_fragmentation_total_size = 0;
2473             hci_stack->acl_fragmentation_pos = 0;
2474         }
2475     }
2476 
2477     if (!hci_can_send_command_packet_now()) return;
2478 
2479     // global/non-connection oriented commands
2480 
2481 #ifdef ENABLE_CLASSIC
2482     // decline incoming connections
2483     if (hci_stack->decline_reason){
2484         uint8_t reason = hci_stack->decline_reason;
2485         hci_stack->decline_reason = 0;
2486         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
2487         return;
2488     }
2489 
2490     // send scan enable
2491     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
2492         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
2493         hci_stack->new_scan_enable_value = 0xff;
2494         return;
2495     }
2496 #endif
2497 
2498 #ifdef ENABLE_BLE
2499     if (hci_stack->state == HCI_STATE_WORKING){
2500         // handle le scan
2501         switch(hci_stack->le_scanning_state){
2502             case LE_START_SCAN:
2503                 hci_stack->le_scanning_state = LE_SCANNING;
2504                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
2505                 return;
2506 
2507             case LE_STOP_SCAN:
2508                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
2509                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
2510                 return;
2511             default:
2512                 break;
2513         }
2514         if (hci_stack->le_scan_type != 0xff){
2515             // defaults: active scanning, accept all advertisement packets
2516             int scan_type = hci_stack->le_scan_type;
2517             hci_stack->le_scan_type = 0xff;
2518             hci_send_cmd(&hci_le_set_scan_parameters, scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->adv_addr_type, 0);
2519             return;
2520         }
2521         // le advertisement control
2522         if (hci_stack->le_advertisements_todo){
2523             log_info("hci_run: gap_le: adv todo: %x", hci_stack->le_advertisements_todo );
2524         }
2525         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_DISABLE){
2526             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_DISABLE;
2527             hci_send_cmd(&hci_le_set_advertise_enable, 0);
2528             return;
2529         }
2530         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
2531             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
2532             hci_send_cmd(&hci_le_set_advertising_parameters,
2533                  hci_stack->le_advertisements_interval_min,
2534                  hci_stack->le_advertisements_interval_max,
2535                  hci_stack->le_advertisements_type,
2536                  hci_stack->le_advertisements_own_address_type,
2537                  hci_stack->le_advertisements_direct_address_type,
2538                  hci_stack->le_advertisements_direct_address,
2539                  hci_stack->le_advertisements_channel_map,
2540                  hci_stack->le_advertisements_filter_policy);
2541             return;
2542         }
2543         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
2544             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
2545             hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len,
2546                 hci_stack->le_advertisements_data);
2547             return;
2548         }
2549         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
2550             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
2551             hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len,
2552                 hci_stack->le_scan_response_data);
2553             return;
2554         }
2555         // Random address needs to be set before enabling advertisements
2556         if ((hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_ENABLE)
2557         &&  (hci_stack->le_advertisements_own_address_type == 0 || hci_stack->le_advertisements_random_address_set)){
2558             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_ENABLE;
2559             hci_send_cmd(&hci_le_set_advertise_enable, 1);
2560             return;
2561         }
2562 
2563         //
2564         // LE Whitelist Management
2565         //
2566 
2567         // check if whitelist needs modification
2568         btstack_linked_list_iterator_t lit;
2569         int modification_pending = 0;
2570         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2571         while (btstack_linked_list_iterator_has_next(&lit)){
2572             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2573             if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
2574                 modification_pending = 1;
2575                 break;
2576             }
2577         }
2578 
2579         if (modification_pending){
2580             // stop connnecting if modification pending
2581             if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
2582                 hci_send_cmd(&hci_le_create_connection_cancel);
2583                 return;
2584             }
2585 
2586             // add/remove entries
2587             btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2588             while (btstack_linked_list_iterator_has_next(&lit)){
2589                 whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2590                 if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
2591                     entry->state = LE_WHITELIST_ON_CONTROLLER;
2592                     hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
2593                     return;
2594 
2595                 }
2596                 if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
2597                     bd_addr_t address;
2598                     bd_addr_type_t address_type = entry->address_type;
2599                     memcpy(address, entry->address, 6);
2600                     btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
2601                     btstack_memory_whitelist_entry_free(entry);
2602                     hci_send_cmd(&hci_le_remove_device_from_white_list, address_type, address);
2603                     return;
2604                 }
2605             }
2606         }
2607 
2608         // start connecting
2609         if ( hci_stack->le_connecting_state == LE_CONNECTING_IDLE &&
2610             !btstack_linked_list_empty(&hci_stack->le_whitelist)){
2611             bd_addr_t null_addr;
2612             memset(null_addr, 0, 6);
2613             hci_send_cmd(&hci_le_create_connection,
2614                  0x0060,    // scan interval: 60 ms
2615                  0x0030,    // scan interval: 30 ms
2616                  1,         // use whitelist
2617                  0,         // peer address type
2618                  null_addr,      // peer bd addr
2619                  hci_stack->adv_addr_type, // our addr type:
2620                  0x0008,    // conn interval min
2621                  0x0018,    // conn interval max
2622                  0,         // conn latency
2623                  0x0048,    // supervision timeout
2624                  0x0001,    // min ce length
2625                  0x0001     // max ce length
2626                  );
2627             return;
2628         }
2629     }
2630 #endif
2631 
2632     // send pending HCI commands
2633     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
2634         hci_connection_t * connection = (hci_connection_t *) it;
2635 
2636         switch(connection->state){
2637             case SEND_CREATE_CONNECTION:
2638                 switch(connection->address_type){
2639 #ifdef ENABLE_CLASSIC
2640                     case BD_ADDR_TYPE_CLASSIC:
2641                         log_info("sending hci_create_connection");
2642                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
2643                         break;
2644 #endif
2645                     default:
2646 #ifdef ENABLE_BLE
2647                         log_info("sending hci_le_create_connection");
2648                         hci_send_cmd(&hci_le_create_connection,
2649                                      0x0060,    // scan interval: 60 ms
2650                                      0x0030,    // scan interval: 30 ms
2651                                      0,         // don't use whitelist
2652                                      connection->address_type, // peer address type
2653                                      connection->address,      // peer bd addr
2654                                      hci_stack->adv_addr_type, // our addr type:
2655                                      0x0008,    // conn interval min
2656                                      0x0018,    // conn interval max
2657                                      0,         // conn latency
2658                                      0x0048,    // supervision timeout
2659                                      0x0001,    // min ce length
2660                                      0x0001     // max ce length
2661                                      );
2662 
2663                         connection->state = SENT_CREATE_CONNECTION;
2664 #endif
2665                         break;
2666                 }
2667                 return;
2668 
2669 #ifdef ENABLE_CLASSIC
2670             case RECEIVED_CONNECTION_REQUEST:
2671                 log_info("sending hci_accept_connection_request, remote eSCO %u", connection->remote_supported_feature_eSCO);
2672                 connection->state = ACCEPTED_CONNECTION_REQUEST;
2673                 connection->role  = HCI_ROLE_SLAVE;
2674                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
2675                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
2676                 }
2677                 return;
2678 #endif
2679 
2680 #ifdef ENABLE_BLE
2681             case SEND_CANCEL_CONNECTION:
2682                 connection->state = SENT_CANCEL_CONNECTION;
2683                 hci_send_cmd(&hci_le_create_connection_cancel);
2684                 return;
2685 #endif
2686             case SEND_DISCONNECT:
2687                 connection->state = SENT_DISCONNECT;
2688                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
2689                 return;
2690 
2691             default:
2692                 break;
2693         }
2694 
2695 #ifdef ENABLE_CLASSIC
2696         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
2697             log_info("responding to link key request");
2698             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
2699             link_key_t link_key;
2700             link_key_type_t link_key_type;
2701             if ( hci_stack->link_key_db
2702               && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type)
2703               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
2704                connection->link_key_type = link_key_type;
2705                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
2706             } else {
2707                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
2708             }
2709             return;
2710         }
2711 
2712         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
2713             log_info("denying to pin request");
2714             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
2715             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
2716             return;
2717         }
2718 
2719         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
2720             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
2721             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
2722             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
2723                 // tweak authentication requirements
2724                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
2725                 if (connection->bonding_flags & BONDING_DEDICATED){
2726                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2727                 }
2728                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
2729                     authreq |= 1;
2730                 }
2731                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
2732             } else {
2733                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
2734             }
2735             return;
2736         }
2737 
2738         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
2739             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
2740             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
2741             return;
2742         }
2743 
2744         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
2745             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
2746             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
2747             return;
2748         }
2749 #endif
2750 
2751         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
2752             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
2753             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
2754             return;
2755         }
2756 
2757         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
2758             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
2759             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
2760             return;
2761         }
2762         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
2763             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
2764             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
2765             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
2766             return;
2767         }
2768         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
2769             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
2770             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
2771             return;
2772         }
2773         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2774             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2775             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2776             return;
2777         }
2778 
2779 #ifdef ENABLE_BLE
2780         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2781             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2782 
2783             uint16_t connection_interval_min = connection->le_conn_interval_min;
2784             connection->le_conn_interval_min = 0;
2785             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2786                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2787                 0x0000, 0xffff);
2788         }
2789 #endif
2790     }
2791 
2792     hci_connection_t * connection;
2793     switch (hci_stack->state){
2794         case HCI_STATE_INITIALIZING:
2795             hci_initializing_run();
2796             break;
2797 
2798         case HCI_STATE_HALTING:
2799 
2800             log_info("HCI_STATE_HALTING");
2801 
2802             // free whitelist entries
2803 #ifdef ENABLE_BLE
2804             {
2805                 btstack_linked_list_iterator_t lit;
2806                 btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2807                 while (btstack_linked_list_iterator_has_next(&lit)){
2808                     whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2809                     btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
2810                     btstack_memory_whitelist_entry_free(entry);
2811                 }
2812             }
2813 #endif
2814             // close all open connections
2815             connection =  (hci_connection_t *) hci_stack->connections;
2816             if (connection){
2817                 hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
2818                 if (!hci_can_send_command_packet_now()) return;
2819 
2820                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
2821 
2822                 // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
2823                 hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
2824 
2825                 // ... which would be ignored anyway as we shutdown (free) the connection now
2826                 hci_shutdown_connection(connection);
2827 
2828                 // finally, send the disconnect command
2829                 hci_send_cmd(&hci_disconnect, con_handle, 0x13);  // remote closed connection
2830                 return;
2831             }
2832             log_info("HCI_STATE_HALTING, calling off");
2833 
2834             // switch mode
2835             hci_power_control_off();
2836 
2837             log_info("HCI_STATE_HALTING, emitting state");
2838             hci_emit_state();
2839             log_info("HCI_STATE_HALTING, done");
2840             break;
2841 
2842         case HCI_STATE_FALLING_ASLEEP:
2843             switch(hci_stack->substate) {
2844                 case HCI_FALLING_ASLEEP_DISCONNECT:
2845                     log_info("HCI_STATE_FALLING_ASLEEP");
2846                     // close all open connections
2847                     connection =  (hci_connection_t *) hci_stack->connections;
2848 
2849 #ifdef HAVE_PLATFORM_IPHONE_OS
2850                     // don't close connections, if H4 supports power management
2851                     if (btstack_control_iphone_power_management_enabled()){
2852                         connection = NULL;
2853                     }
2854 #endif
2855                     if (connection){
2856 
2857                         // send disconnect
2858                         if (!hci_can_send_command_packet_now()) return;
2859 
2860                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2861                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2862 
2863                         // send disconnected event right away - causes higher layer connections to get closed, too.
2864                         hci_shutdown_connection(connection);
2865                         return;
2866                     }
2867 
2868                     if (hci_classic_supported()){
2869                         // disable page and inquiry scan
2870                         if (!hci_can_send_command_packet_now()) return;
2871 
2872                         log_info("HCI_STATE_HALTING, disabling inq scans");
2873                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2874 
2875                         // continue in next sub state
2876                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
2877                         break;
2878                     }
2879                     // no break - fall through for ble-only chips
2880 
2881                 case HCI_FALLING_ASLEEP_COMPLETE:
2882                     log_info("HCI_STATE_HALTING, calling sleep");
2883 #ifdef HAVE_PLATFORM_IPHONE_OS
2884                     // don't actually go to sleep, if H4 supports power management
2885                     if (btstack_control_iphone_power_management_enabled()){
2886                         // SLEEP MODE reached
2887                         hci_stack->state = HCI_STATE_SLEEPING;
2888                         hci_emit_state();
2889                         break;
2890                     }
2891 #endif
2892                     // switch mode
2893                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2894                     hci_emit_state();
2895                     break;
2896 
2897                 default:
2898                     break;
2899             }
2900             break;
2901 
2902         default:
2903             break;
2904     }
2905 }
2906 
2907 int hci_send_cmd_packet(uint8_t *packet, int size){
2908     // house-keeping
2909 
2910     if (IS_COMMAND(packet, hci_write_loopback_mode)){
2911         hci_stack->loopback_mode = packet[3];
2912     }
2913 
2914 #ifdef ENABLE_CLASSIC
2915     bd_addr_t addr;
2916     hci_connection_t * conn;
2917 
2918     // create_connection?
2919     if (IS_COMMAND(packet, hci_create_connection)){
2920         reverse_bd_addr(&packet[3], addr);
2921         log_info("Create_connection to %s", bd_addr_to_str(addr));
2922 
2923         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2924         if (!conn){
2925             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2926             if (!conn){
2927                 // notify client that alloc failed
2928                 hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
2929                 return 0; // don't sent packet to controller
2930             }
2931             conn->state = SEND_CREATE_CONNECTION;
2932         }
2933         log_info("conn state %u", conn->state);
2934         switch (conn->state){
2935             // if connection active exists
2936             case OPEN:
2937                 // and OPEN, emit connection complete command, don't send to controller
2938                 hci_emit_connection_complete(addr, conn->con_handle, 0);
2939                 return 0;
2940             case SEND_CREATE_CONNECTION:
2941                 // connection created by hci, e.g. dedicated bonding
2942                 break;
2943             default:
2944                 // otherwise, just ignore as it is already in the open process
2945                 return 0;
2946         }
2947         conn->state = SENT_CREATE_CONNECTION;
2948     }
2949 
2950     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2951         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2952     }
2953     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2954         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2955     }
2956 
2957     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2958         if (hci_stack->link_key_db){
2959             reverse_bd_addr(&packet[3], addr);
2960             hci_stack->link_key_db->delete_link_key(addr);
2961         }
2962     }
2963 
2964     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2965     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2966         reverse_bd_addr(&packet[3], addr);
2967         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2968         if (conn){
2969             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2970         }
2971     }
2972 
2973     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2974     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2975     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2976     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2977         reverse_bd_addr(&packet[3], addr);
2978         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2979         if (conn){
2980             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2981         }
2982     }
2983 #endif
2984 
2985 #ifdef ENABLE_BLE
2986     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2987         hci_stack->adv_addr_type = packet[8];
2988     }
2989     if (IS_COMMAND(packet, hci_le_set_random_address)){
2990         hci_stack->le_advertisements_random_address_set = 1;
2991         reverse_bd_addr(&packet[3], hci_stack->adv_address);
2992     }
2993     if (IS_COMMAND(packet, hci_le_set_advertise_enable)){
2994         hci_stack->le_advertisements_active = packet[3];
2995     }
2996     if (IS_COMMAND(packet, hci_le_create_connection)){
2997         // white list used?
2998         uint8_t initiator_filter_policy = packet[7];
2999         switch (initiator_filter_policy){
3000             case 0:
3001                 // whitelist not used
3002                 hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
3003                 break;
3004             case 1:
3005                 hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
3006                 break;
3007             default:
3008                 log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
3009                 break;
3010         }
3011     }
3012     if (IS_COMMAND(packet, hci_le_create_connection_cancel)){
3013         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3014     }
3015 #endif
3016 
3017     hci_stack->num_cmd_packets--;
3018 
3019     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
3020     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
3021 
3022     // release packet buffer for synchronous transport implementations
3023     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
3024         hci_stack->hci_packet_buffer_reserved = 0;
3025     }
3026 
3027     return err;
3028 }
3029 
3030 // disconnect because of security block
3031 void hci_disconnect_security_block(hci_con_handle_t con_handle){
3032     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3033     if (!connection) return;
3034     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
3035 }
3036 
3037 
3038 // Configure Secure Simple Pairing
3039 
3040 #ifdef ENABLE_CLASSIC
3041 
3042 // enable will enable SSP during init
3043 void gap_ssp_set_enable(int enable){
3044     hci_stack->ssp_enable = enable;
3045 }
3046 
3047 static int hci_local_ssp_activated(void){
3048     return gap_ssp_supported() && hci_stack->ssp_enable;
3049 }
3050 
3051 // if set, BTstack will respond to io capability request using authentication requirement
3052 void gap_ssp_set_io_capability(int io_capability){
3053     hci_stack->ssp_io_capability = io_capability;
3054 }
3055 void gap_ssp_set_authentication_requirement(int authentication_requirement){
3056     hci_stack->ssp_authentication_requirement = authentication_requirement;
3057 }
3058 
3059 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
3060 void gap_ssp_set_auto_accept(int auto_accept){
3061     hci_stack->ssp_auto_accept = auto_accept;
3062 }
3063 #endif
3064 
3065 /**
3066  * pre: numcmds >= 0 - it's allowed to send a command to the controller
3067  */
3068 int hci_send_cmd(const hci_cmd_t *cmd, ...){
3069 
3070     if (!hci_can_send_command_packet_now()){
3071         log_error("hci_send_cmd called but cannot send packet now");
3072         return 0;
3073     }
3074 
3075     // for HCI INITIALIZATION
3076     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
3077     hci_stack->last_cmd_opcode = cmd->opcode;
3078 
3079     hci_reserve_packet_buffer();
3080     uint8_t * packet = hci_stack->hci_packet_buffer;
3081 
3082     va_list argptr;
3083     va_start(argptr, cmd);
3084     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
3085     va_end(argptr);
3086 
3087     return hci_send_cmd_packet(packet, size);
3088 }
3089 
3090 // Create various non-HCI events.
3091 // TODO: generalize, use table similar to hci_create_command
3092 
3093 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
3094     // dump packet
3095     if (dump) {
3096         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
3097     }
3098 
3099     // dispatch to all event handlers
3100     btstack_linked_list_iterator_t it;
3101     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
3102     while (btstack_linked_list_iterator_has_next(&it)){
3103         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
3104         entry->callback(HCI_EVENT_PACKET, 0, event, size);
3105     }
3106 }
3107 
3108 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
3109     if (!hci_stack->acl_packet_handler) return;
3110     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
3111 }
3112 
3113 #ifdef ENABLE_CLASSIC
3114 static void hci_notify_if_sco_can_send_now(void){
3115     // notify SCO sender if waiting
3116     if (!hci_stack->sco_waiting_for_can_send_now) return;
3117     if (hci_can_send_sco_packet_now()){
3118         hci_stack->sco_waiting_for_can_send_now = 0;
3119         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
3120         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
3121         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
3122     }
3123 }
3124 #endif
3125 
3126 void hci_emit_state(void){
3127     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
3128     uint8_t event[3];
3129     event[0] = BTSTACK_EVENT_STATE;
3130     event[1] = sizeof(event) - 2;
3131     event[2] = hci_stack->state;
3132     hci_emit_event(event, sizeof(event), 1);
3133 }
3134 
3135 #ifdef ENABLE_CLASSIC
3136 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
3137     uint8_t event[13];
3138     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
3139     event[1] = sizeof(event) - 2;
3140     event[2] = status;
3141     little_endian_store_16(event, 3, con_handle);
3142     reverse_bd_addr(address, &event[5]);
3143     event[11] = 1; // ACL connection
3144     event[12] = 0; // encryption disabled
3145     hci_emit_event(event, sizeof(event), 1);
3146 }
3147 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
3148     if (disable_l2cap_timeouts) return;
3149     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
3150     uint8_t event[4];
3151     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
3152     event[1] = sizeof(event) - 2;
3153     little_endian_store_16(event, 2, conn->con_handle);
3154     hci_emit_event(event, sizeof(event), 1);
3155 }
3156 #endif
3157 
3158 #ifdef ENABLE_BLE
3159 static void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
3160     uint8_t event[21];
3161     event[0] = HCI_EVENT_LE_META;
3162     event[1] = sizeof(event) - 2;
3163     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
3164     event[3] = status;
3165     little_endian_store_16(event, 4, con_handle);
3166     event[6] = 0; // TODO: role
3167     event[7] = address_type;
3168     reverse_bd_addr(address, &event[8]);
3169     little_endian_store_16(event, 14, 0); // interval
3170     little_endian_store_16(event, 16, 0); // latency
3171     little_endian_store_16(event, 18, 0); // supervision timeout
3172     event[20] = 0; // master clock accuracy
3173     hci_emit_event(event, sizeof(event), 1);
3174 }
3175 #endif
3176 
3177 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
3178     uint8_t event[6];
3179     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
3180     event[1] = sizeof(event) - 2;
3181     event[2] = 0; // status = OK
3182     little_endian_store_16(event, 3, con_handle);
3183     event[5] = reason;
3184     hci_emit_event(event, sizeof(event), 1);
3185 }
3186 
3187 static void hci_emit_nr_connections_changed(void){
3188     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
3189     uint8_t event[3];
3190     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
3191     event[1] = sizeof(event) - 2;
3192     event[2] = nr_hci_connections();
3193     hci_emit_event(event, sizeof(event), 1);
3194 }
3195 
3196 static void hci_emit_hci_open_failed(void){
3197     log_info("BTSTACK_EVENT_POWERON_FAILED");
3198     uint8_t event[2];
3199     event[0] = BTSTACK_EVENT_POWERON_FAILED;
3200     event[1] = sizeof(event) - 2;
3201     hci_emit_event(event, sizeof(event), 1);
3202 }
3203 
3204 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
3205     log_info("hci_emit_dedicated_bonding_result %u ", status);
3206     uint8_t event[9];
3207     int pos = 0;
3208     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
3209     event[pos++] = sizeof(event) - 2;
3210     event[pos++] = status;
3211     reverse_bd_addr(address, &event[pos]);
3212     hci_emit_event(event, sizeof(event), 1);
3213 }
3214 
3215 
3216 #ifdef ENABLE_CLASSIC
3217 
3218 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
3219     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
3220     uint8_t event[5];
3221     int pos = 0;
3222     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
3223     event[pos++] = sizeof(event) - 2;
3224     little_endian_store_16(event, 2, con_handle);
3225     pos += 2;
3226     event[pos++] = level;
3227     hci_emit_event(event, sizeof(event), 1);
3228 }
3229 
3230 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
3231     if (!connection) return LEVEL_0;
3232     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
3233     return gap_security_level_for_link_key_type(connection->link_key_type);
3234 }
3235 
3236 static void hci_emit_discoverable_enabled(uint8_t enabled){
3237     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
3238     uint8_t event[3];
3239     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
3240     event[1] = sizeof(event) - 2;
3241     event[2] = enabled;
3242     hci_emit_event(event, sizeof(event), 1);
3243 }
3244 
3245 // query if remote side supports eSCO
3246 int hci_remote_esco_supported(hci_con_handle_t con_handle){
3247     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3248     if (!connection) return 0;
3249     return connection->remote_supported_feature_eSCO;
3250 }
3251 
3252 // query if remote side supports SSP
3253 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
3254     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3255     if (!connection) return 0;
3256     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
3257 }
3258 
3259 int gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
3260     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
3261 }
3262 
3263 // GAP API
3264 /**
3265  * @bbrief enable/disable bonding. default is enabled
3266  * @praram enabled
3267  */
3268 void gap_set_bondable_mode(int enable){
3269     hci_stack->bondable = enable ? 1 : 0;
3270 }
3271 /**
3272  * @brief Get bondable mode.
3273  * @return 1 if bondable
3274  */
3275 int gap_get_bondable_mode(void){
3276     return hci_stack->bondable;
3277 }
3278 
3279 /**
3280  * @brief map link keys to security levels
3281  */
3282 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
3283     switch (link_key_type){
3284         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
3285             return LEVEL_4;
3286         case COMBINATION_KEY:
3287         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
3288             return LEVEL_3;
3289         default:
3290             return LEVEL_2;
3291     }
3292 }
3293 
3294 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
3295     log_info("gap_mitm_protection_required_for_security_level %u", level);
3296     return level > LEVEL_2;
3297 }
3298 
3299 /**
3300  * @brief get current security level
3301  */
3302 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
3303     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3304     if (!connection) return LEVEL_0;
3305     return gap_security_level_for_connection(connection);
3306 }
3307 
3308 /**
3309  * @brief request connection to device to
3310  * @result GAP_AUTHENTICATION_RESULT
3311  */
3312 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
3313     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3314     if (!connection){
3315         hci_emit_security_level(con_handle, LEVEL_0);
3316         return;
3317     }
3318     gap_security_level_t current_level = gap_security_level(con_handle);
3319     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
3320     if (current_level >= requested_level){
3321         hci_emit_security_level(con_handle, current_level);
3322         return;
3323     }
3324 
3325     connection->requested_security_level = requested_level;
3326 
3327 #if 0
3328     // sending encryption request without a link key results in an error.
3329     // TODO: figure out how to use it properly
3330 
3331     // would enabling ecnryption suffice (>= LEVEL_2)?
3332     if (hci_stack->link_key_db){
3333         link_key_type_t link_key_type;
3334         link_key_t      link_key;
3335         if (hci_stack->link_key_db->get_link_key( &connection->address, &link_key, &link_key_type)){
3336             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
3337                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3338                 return;
3339             }
3340         }
3341     }
3342 #endif
3343 
3344     // try to authenticate connection
3345     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
3346     hci_run();
3347 }
3348 
3349 /**
3350  * @brief start dedicated bonding with device. disconnect after bonding
3351  * @param device
3352  * @param request MITM protection
3353  * @result GAP_DEDICATED_BONDING_COMPLETE
3354  */
3355 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
3356 
3357     // create connection state machine
3358     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
3359 
3360     if (!connection){
3361         return BTSTACK_MEMORY_ALLOC_FAILED;
3362     }
3363 
3364     // delete linkn key
3365     gap_drop_link_key_for_bd_addr(device);
3366 
3367     // configure LEVEL_2/3, dedicated bonding
3368     connection->state = SEND_CREATE_CONNECTION;
3369     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
3370     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
3371     connection->bonding_flags = BONDING_DEDICATED;
3372 
3373     // wait for GAP Security Result and send GAP Dedicated Bonding complete
3374 
3375     // handle: connnection failure (connection complete != ok)
3376     // handle: authentication failure
3377     // handle: disconnect on done
3378 
3379     hci_run();
3380 
3381     return 0;
3382 }
3383 #endif
3384 
3385 void gap_set_local_name(const char * local_name){
3386     hci_stack->local_name = local_name;
3387 }
3388 
3389 
3390 #ifdef ENABLE_BLE
3391 
3392 void gap_start_scan(void){
3393     if (hci_stack->le_scanning_state == LE_SCANNING) return;
3394     hci_stack->le_scanning_state = LE_START_SCAN;
3395     hci_run();
3396 }
3397 
3398 void gap_stop_scan(void){
3399     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return;
3400     hci_stack->le_scanning_state = LE_STOP_SCAN;
3401     hci_run();
3402 }
3403 
3404 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
3405     hci_stack->le_scan_type     = scan_type;
3406     hci_stack->le_scan_interval = scan_interval;
3407     hci_stack->le_scan_window   = scan_window;
3408     hci_run();
3409 }
3410 
3411 uint8_t gap_connect(bd_addr_t addr, bd_addr_type_t addr_type){
3412     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3413     if (!conn){
3414         log_info("gap_connect: no connection exists yet, creating context");
3415         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
3416         if (!conn){
3417             // notify client that alloc failed
3418             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
3419             log_info("gap_connect: failed to alloc hci_connection_t");
3420             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
3421         }
3422         conn->state = SEND_CREATE_CONNECTION;
3423         log_info("gap_connect: send create connection next");
3424         hci_run();
3425         return 0;
3426     }
3427 
3428     if (!hci_is_le_connection(conn) ||
3429         conn->state == SEND_CREATE_CONNECTION ||
3430         conn->state == SENT_CREATE_CONNECTION) {
3431         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
3432         log_error("gap_connect: classic connection or connect is already being created");
3433         return GATT_CLIENT_IN_WRONG_STATE;
3434     }
3435 
3436     log_info("gap_connect: context exists with state %u", conn->state);
3437     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
3438     hci_run();
3439     return 0;
3440 }
3441 
3442 // @assumption: only a single outgoing LE Connection exists
3443 static hci_connection_t * gap_get_outgoing_connection(void){
3444     btstack_linked_item_t *it;
3445     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3446         hci_connection_t * conn = (hci_connection_t *) it;
3447         if (!hci_is_le_connection(conn)) continue;
3448         switch (conn->state){
3449             case SEND_CREATE_CONNECTION:
3450             case SENT_CREATE_CONNECTION:
3451                 return conn;
3452             default:
3453                 break;
3454         };
3455     }
3456     return NULL;
3457 }
3458 
3459 uint8_t gap_connect_cancel(void){
3460     hci_connection_t * conn = gap_get_outgoing_connection();
3461     if (!conn) return 0;
3462     switch (conn->state){
3463         case SEND_CREATE_CONNECTION:
3464             // skip sending create connection and emit event instead
3465             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
3466             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
3467             btstack_memory_hci_connection_free( conn );
3468             break;
3469         case SENT_CREATE_CONNECTION:
3470             // request to send cancel connection
3471             conn->state = SEND_CANCEL_CONNECTION;
3472             hci_run();
3473             break;
3474         default:
3475             break;
3476     }
3477     return 0;
3478 }
3479 
3480 /**
3481  * @brief Updates the connection parameters for a given LE connection
3482  * @param handle
3483  * @param conn_interval_min (unit: 1.25ms)
3484  * @param conn_interval_max (unit: 1.25ms)
3485  * @param conn_latency
3486  * @param supervision_timeout (unit: 10ms)
3487  * @returns 0 if ok
3488  */
3489 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
3490     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
3491     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3492     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3493     connection->le_conn_interval_min = conn_interval_min;
3494     connection->le_conn_interval_max = conn_interval_max;
3495     connection->le_conn_latency = conn_latency;
3496     connection->le_supervision_timeout = supervision_timeout;
3497     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
3498     hci_run();
3499     return 0;
3500 }
3501 
3502 /**
3503  * @brief Request an update of the connection parameter for a given LE connection
3504  * @param handle
3505  * @param conn_interval_min (unit: 1.25ms)
3506  * @param conn_interval_max (unit: 1.25ms)
3507  * @param conn_latency
3508  * @param supervision_timeout (unit: 10ms)
3509  * @returns 0 if ok
3510  */
3511 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
3512     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
3513     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3514     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3515     connection->le_conn_interval_min = conn_interval_min;
3516     connection->le_conn_interval_max = conn_interval_max;
3517     connection->le_conn_latency = conn_latency;
3518     connection->le_supervision_timeout = supervision_timeout;
3519     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
3520     hci_run();
3521     return 0;
3522 }
3523 
3524 static void gap_advertisments_changed(void){
3525     // disable advertisements before updating adv, scan data, or adv params
3526     if (hci_stack->le_advertisements_active){
3527         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE | LE_ADVERTISEMENT_TASKS_ENABLE;
3528     }
3529     hci_run();
3530 }
3531 
3532 /**
3533  * @brief Set Advertisement Data
3534  * @param advertising_data_length
3535  * @param advertising_data (max 31 octets)
3536  * @note data is not copied, pointer has to stay valid
3537  */
3538 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
3539     hci_stack->le_advertisements_data_len = advertising_data_length;
3540     hci_stack->le_advertisements_data = advertising_data;
3541     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3542     gap_advertisments_changed();
3543 }
3544 
3545 /**
3546  * @brief Set Scan Response Data
3547  * @param advertising_data_length
3548  * @param advertising_data (max 31 octets)
3549  * @note data is not copied, pointer has to stay valid
3550  */
3551 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
3552     hci_stack->le_scan_response_data_len = scan_response_data_length;
3553     hci_stack->le_scan_response_data = scan_response_data;
3554     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
3555     gap_advertisments_changed();
3556 }
3557 
3558 /**
3559  * @brief Set Advertisement Parameters
3560  * @param adv_int_min
3561  * @param adv_int_max
3562  * @param adv_type
3563  * @param own_address_type
3564  * @param direct_address_type
3565  * @param direct_address
3566  * @param channel_map
3567  * @param filter_policy
3568  *
3569  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
3570  */
3571  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
3572     uint8_t own_address_type, uint8_t direct_address_typ, bd_addr_t direct_address,
3573     uint8_t channel_map, uint8_t filter_policy) {
3574 
3575     hci_stack->le_advertisements_interval_min = adv_int_min;
3576     hci_stack->le_advertisements_interval_max = adv_int_max;
3577     hci_stack->le_advertisements_type = adv_type;
3578     hci_stack->le_advertisements_own_address_type = own_address_type;
3579     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
3580     hci_stack->le_advertisements_channel_map = channel_map;
3581     hci_stack->le_advertisements_filter_policy = filter_policy;
3582     memcpy(hci_stack->le_advertisements_direct_address, direct_address, 6);
3583 
3584     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3585     gap_advertisments_changed();
3586  }
3587 
3588 void hci_le_advertisements_set_own_address_type(uint8_t own_address_type){
3589     hci_stack->le_advertisements_own_address_type = own_address_type;
3590     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3591     gap_advertisments_changed();
3592 }
3593 
3594 /**
3595  * @brief Enable/Disable Advertisements
3596  * @param enabled
3597  */
3598 void gap_advertisements_enable(int enabled){
3599     hci_stack->le_advertisements_enabled = enabled;
3600     if (enabled && !hci_stack->le_advertisements_active){
3601         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
3602     }
3603     if (!enabled && hci_stack->le_advertisements_active){
3604         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE;
3605     }
3606     hci_run();
3607 }
3608 
3609 #endif
3610 
3611 uint8_t gap_disconnect(hci_con_handle_t handle){
3612     hci_connection_t * conn = hci_connection_for_handle(handle);
3613     if (!conn){
3614         hci_emit_disconnection_complete(handle, 0);
3615         return 0;
3616     }
3617     conn->state = SEND_DISCONNECT;
3618     hci_run();
3619     return 0;
3620 }
3621 
3622 /**
3623  * @brief Get connection type
3624  * @param con_handle
3625  * @result connection_type
3626  */
3627 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
3628     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
3629     if (!conn) return GAP_CONNECTION_INVALID;
3630     switch (conn->address_type){
3631         case BD_ADDR_TYPE_LE_PUBLIC:
3632         case BD_ADDR_TYPE_LE_RANDOM:
3633             return GAP_CONNECTION_LE;
3634         case BD_ADDR_TYPE_SCO:
3635             return GAP_CONNECTION_SCO;
3636         case BD_ADDR_TYPE_CLASSIC:
3637             return GAP_CONNECTION_ACL;
3638         default:
3639             return GAP_CONNECTION_INVALID;
3640     }
3641 }
3642 
3643 #ifdef ENABLE_BLE
3644 
3645 /**
3646  * @brief Auto Connection Establishment - Start Connecting to device
3647  * @param address_typ
3648  * @param address
3649  * @returns 0 if ok
3650  */
3651 int gap_auto_connection_start(bd_addr_type_t address_type, bd_addr_t address){
3652     // check capacity
3653     int num_entries = btstack_linked_list_count(&hci_stack->le_whitelist);
3654     if (num_entries >= hci_stack->le_whitelist_capacity) return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
3655     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
3656     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
3657     entry->address_type = address_type;
3658     memcpy(entry->address, address, 6);
3659     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
3660     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
3661     hci_run();
3662     return 0;
3663 }
3664 
3665 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address){
3666     btstack_linked_list_iterator_t it;
3667     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
3668     while (btstack_linked_list_iterator_has_next(&it)){
3669         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
3670         if (entry->address_type != address_type) continue;
3671         if (memcmp(entry->address, address, 6) != 0) continue;
3672         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
3673             // remove from controller if already present
3674             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3675             continue;
3676         }
3677         // direclty remove entry from whitelist
3678         btstack_linked_list_iterator_remove(&it);
3679         btstack_memory_whitelist_entry_free(entry);
3680     }
3681 }
3682 
3683 /**
3684  * @brief Auto Connection Establishment - Stop Connecting to device
3685  * @param address_typ
3686  * @param address
3687  * @returns 0 if ok
3688  */
3689 int gap_auto_connection_stop(bd_addr_type_t address_type, bd_addr_t address){
3690     hci_remove_from_whitelist(address_type, address);
3691     hci_run();
3692     return 0;
3693 }
3694 
3695 /**
3696  * @brief Auto Connection Establishment - Stop everything
3697  * @note  Convenience function to stop all active auto connection attempts
3698  */
3699 void gap_auto_connection_stop_all(void){
3700     btstack_linked_list_iterator_t it;
3701     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
3702     while (btstack_linked_list_iterator_has_next(&it)){
3703         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
3704         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
3705             // remove from controller if already present
3706             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3707             continue;
3708         }
3709         // directly remove entry from whitelist
3710         btstack_linked_list_iterator_remove(&it);
3711         btstack_memory_whitelist_entry_free(entry);
3712     }
3713     hci_run();
3714 }
3715 
3716 #endif
3717 
3718 #ifdef ENABLE_CLASSIC
3719 /**
3720  * @brief Set Extended Inquiry Response data
3721  * @param eir_data size 240 bytes, is not copied make sure memory is accessible during stack startup
3722  * @note has to be done before stack starts up
3723  */
3724 void gap_set_extended_inquiry_response(const uint8_t * data){
3725     hci_stack->eir_data = data;
3726 }
3727 
3728 /**
3729  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
3730  * @param inquriy_mode see bluetooth_defines.h
3731  */
3732 void hci_set_inquiry_mode(inquiry_mode_t mode){
3733     hci_stack->inquiry_mode = mode;
3734 }
3735 
3736 /**
3737  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
3738  */
3739 void hci_set_sco_voice_setting(uint16_t voice_setting){
3740     hci_stack->sco_voice_setting = voice_setting;
3741 }
3742 
3743 /**
3744  * @brief Get SCO Voice Setting
3745  * @return current voice setting
3746  */
3747 uint16_t hci_get_sco_voice_setting(void){
3748     return hci_stack->sco_voice_setting;
3749 }
3750 
3751 /** @brief Get SCO packet length for current SCO Voice setting
3752  *  @note  Using SCO packets of the exact length is required for USB transfer
3753  *  @return Length of SCO packets in bytes (not audio frames)
3754  */
3755 int hci_get_sco_packet_length(void){
3756     // see Core Spec for H2 USB Transfer.
3757     if (hci_stack->sco_voice_setting & 0x0020) return 51;
3758     return 27;
3759 }
3760 #endif
3761 
3762 /**
3763  * @brief Set callback for Bluetooth Hardware Error
3764  */
3765 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
3766     hci_stack->hardware_error_callback = fn;
3767 }
3768 
3769 /**
3770  * @brief Set callback for local information from Bluetooth controller right after HCI Reset
3771  * @note Can be used to select chipset driver dynamically during startup
3772  */
3773 void hci_set_local_version_information_callback(void (*fn)(uint8_t * local_version_information)){
3774     hci_stack->local_version_information_callback = fn;
3775 }
3776 
3777 void hci_disconnect_all(void){
3778     btstack_linked_list_iterator_t it;
3779     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
3780     while (btstack_linked_list_iterator_has_next(&it)){
3781         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
3782         if (con->state == SENT_DISCONNECT) continue;
3783         con->state = SEND_DISCONNECT;
3784     }
3785     hci_run();
3786 }
3787 
3788 uint16_t hci_get_manufacturer(void){
3789     return hci_stack->manufacturer;
3790 }
3791