xref: /btstack/src/hci.c (revision 0e5ac34f5e21c47174184f4aa304105b2982e14d)
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 static void hci_update_scan_enable(void);
80 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
81 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
82 static void hci_connection_timestamp(hci_connection_t *connection);
83 static int  hci_power_control_on(void);
84 static void hci_power_control_off(void);
85 static void hci_state_reset(void);
86 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
87 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
88 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
89 static void hci_emit_nr_connections_changed(void);
90 static void hci_emit_hci_open_failed(void);
91 static void hci_emit_discoverable_enabled(uint8_t enabled);
92 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
93 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
94 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
95 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
96 static void hci_notify_if_sco_can_send_now(void);
97 static void hci_run(void);
98 static int  hci_is_le_connection(hci_connection_t * connection);
99 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
100 static int  hci_local_ssp_activated(void);
101 static int  hci_remote_ssp_supported(hci_con_handle_t con_handle);
102 
103 #ifdef ENABLE_BLE
104 // called from test/ble_client/advertising_data_parser.c
105 void le_handle_advertisement_report(uint8_t *packet, int size);
106 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address);
107 #endif
108 
109 // the STACK is here
110 #ifndef HAVE_MALLOC
111 static hci_stack_t   hci_stack_static;
112 #endif
113 static hci_stack_t * hci_stack = NULL;
114 
115 // test helper
116 static uint8_t disable_l2cap_timeouts = 0;
117 
118 /**
119  * create connection for given address
120  *
121  * @return connection OR NULL, if no memory left
122  */
123 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
124     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
125     hci_connection_t * conn = btstack_memory_hci_connection_get();
126     if (!conn) return NULL;
127     memset(conn, 0, sizeof(hci_connection_t));
128     bd_addr_copy(conn->address, addr);
129     conn->address_type = addr_type;
130     conn->con_handle = 0xffff;
131     conn->authentication_flags = AUTH_FLAGS_NONE;
132     conn->bonding_flags = 0;
133     conn->requested_security_level = LEVEL_0;
134     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
135     btstack_run_loop_set_timer_context(&conn->timeout, conn);
136     hci_connection_timestamp(conn);
137     conn->acl_recombination_length = 0;
138     conn->acl_recombination_pos = 0;
139     conn->num_acl_packets_sent = 0;
140     conn->num_sco_packets_sent = 0;
141     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
142     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
143     return conn;
144 }
145 
146 
147 /**
148  * get le connection parameter range
149 *
150  * @return le connection parameter range struct
151  */
152 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
153     *range = hci_stack->le_connection_parameter_range;
154 }
155 
156 /**
157  * set le connection parameter range
158  *
159  */
160 
161 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
162     hci_stack->le_connection_parameter_range = *range;
163 }
164 
165 /**
166  * get hci connections iterator
167  *
168  * @return hci connections iterator
169  */
170 
171 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
172     btstack_linked_list_iterator_init(it, &hci_stack->connections);
173 }
174 
175 /**
176  * get connection for a given handle
177  *
178  * @return connection OR NULL, if not found
179  */
180 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
181     btstack_linked_list_iterator_t it;
182     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
183     while (btstack_linked_list_iterator_has_next(&it)){
184         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
185         if ( item->con_handle == con_handle ) {
186             return item;
187         }
188     }
189     return NULL;
190 }
191 
192 /**
193  * get connection for given address
194  *
195  * @return connection OR NULL, if not found
196  */
197 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t  addr, bd_addr_type_t addr_type){
198     btstack_linked_list_iterator_t it;
199     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
200     while (btstack_linked_list_iterator_has_next(&it)){
201         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
202         if (connection->address_type != addr_type)  continue;
203         if (memcmp(addr, connection->address, 6) != 0) continue;
204         return connection;
205     }
206     return NULL;
207 }
208 
209 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
210     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
211 #ifdef HAVE_EMBEDDED_TICK
212     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
213         // connections might be timed out
214         hci_emit_l2cap_check_timeout(connection);
215     }
216 #else
217     if (btstack_run_loop_get_time_ms() > connection->timestamp + HCI_CONNECTION_TIMEOUT_MS){
218         // connections might be timed out
219         hci_emit_l2cap_check_timeout(connection);
220     }
221 #endif
222 }
223 
224 static void hci_connection_timestamp(hci_connection_t *connection){
225 #ifdef HAVE_EMBEDDED_TICK
226     connection->timestamp = btstack_run_loop_embedded_get_ticks();
227 #else
228     connection->timestamp = btstack_run_loop_get_time_ms();
229 #endif
230 }
231 
232 
233 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
234     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
235 }
236 
237 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
238     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
239 }
240 
241 
242 /**
243  * add authentication flags and reset timer
244  * @note: assumes classic connection
245  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
246  */
247 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
248     bd_addr_t addr;
249     reverse_bd_addr(bd_addr, addr);
250     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
251     if (conn) {
252         connectionSetAuthenticationFlags(conn, flags);
253         hci_connection_timestamp(conn);
254     }
255 }
256 
257 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
258     hci_connection_t * conn = hci_connection_for_handle(handle);
259     if (!conn) return 0;
260     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
261     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
262     return 0;
263 }
264 
265 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
266     if (!hci_stack->link_key_db) return;
267     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
268     hci_stack->link_key_db->delete_link_key(addr);
269 }
270 
271 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
272     if (!hci_stack->link_key_db) return;
273     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
274     hci_stack->link_key_db->put_link_key(addr, link_key, type);
275 }
276 
277 static int hci_is_le_connection(hci_connection_t * connection){
278     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
279     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
280 }
281 
282 /**
283  * count connections
284  */
285 static int nr_hci_connections(void){
286     int count = 0;
287     btstack_linked_item_t *it;
288     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
289     return count;
290 }
291 
292 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
293 
294     int num_packets_sent_classic = 0;
295     int num_packets_sent_le = 0;
296 
297     btstack_linked_item_t *it;
298     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
299         hci_connection_t * connection = (hci_connection_t *) it;
300         if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
301             num_packets_sent_classic += connection->num_acl_packets_sent;
302         } else {
303             num_packets_sent_le += connection->num_acl_packets_sent;
304         }
305     }
306     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
307     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
308     int free_slots_le = 0;
309 
310     if (free_slots_classic < 0){
311         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);
312         return 0;
313     }
314 
315     if (hci_stack->le_acl_packets_total_num){
316         // if we have LE slots, they are used
317         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
318         if (free_slots_le < 0){
319             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);
320             return 0;
321         }
322     } else {
323         // otherwise, classic slots are used for LE, too
324         free_slots_classic -= num_packets_sent_le;
325         if (free_slots_classic < 0){
326             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);
327             return 0;
328         }
329     }
330 
331     switch (address_type){
332         case BD_ADDR_TYPE_UNKNOWN:
333             log_error("hci_number_free_acl_slots: unknown address type");
334             return 0;
335 
336         case BD_ADDR_TYPE_CLASSIC:
337             return free_slots_classic;
338 
339         default:
340            if (hci_stack->le_acl_packets_total_num){
341                return free_slots_le;
342            }
343            return free_slots_classic;
344     }
345 }
346 
347 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
348     // get connection type
349     hci_connection_t * connection = hci_connection_for_handle(con_handle);
350     if (!connection){
351         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
352         return 0;
353     }
354     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
355 }
356 
357 static int hci_number_free_sco_slots(void){
358     int num_sco_packets_sent = 0;
359     btstack_linked_item_t *it;
360     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
361         hci_connection_t * connection = (hci_connection_t *) it;
362         num_sco_packets_sent += connection->num_sco_packets_sent;
363     }
364     if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
365         log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
366         return 0;
367     }
368     // log_info("hci_number_free_sco_slots u", handle, num_sco_packets_sent);
369     return hci_stack->sco_packets_total_num - num_sco_packets_sent;
370 }
371 
372 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
373 int hci_can_send_command_packet_now(void){
374     if (hci_stack->hci_packet_buffer_reserved) return 0;
375 
376     // check for async hci transport implementations
377     if (hci_stack->hci_transport->can_send_packet_now){
378         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
379             return 0;
380         }
381     }
382 
383     return hci_stack->num_cmd_packets > 0;
384 }
385 
386 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
387     // check for async hci transport implementations
388     if (!hci_stack->hci_transport->can_send_packet_now) return 1;
389     return hci_stack->hci_transport->can_send_packet_now(packet_type);
390 }
391 
392 static int hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
393     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
394     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
395 }
396 
397 int hci_can_send_acl_classic_packet_now(void){
398     if (hci_stack->hci_packet_buffer_reserved) return 0;
399     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_CLASSIC);
400 }
401 
402 int hci_can_send_acl_le_packet_now(void){
403     if (hci_stack->hci_packet_buffer_reserved) return 0;
404     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
405 }
406 
407 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
408     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return 0;
409     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
410 }
411 
412 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
413     if (hci_stack->hci_packet_buffer_reserved) return 0;
414     return hci_can_send_prepared_acl_packet_now(con_handle);
415 }
416 
417 int hci_can_send_prepared_sco_packet_now(void){
418     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return 0;
419     if (!hci_stack->synchronous_flow_control_enabled) return 1;
420     return hci_number_free_sco_slots() > 0;
421 }
422 
423 int hci_can_send_sco_packet_now(void){
424     if (hci_stack->hci_packet_buffer_reserved) return 0;
425     return hci_can_send_prepared_sco_packet_now();
426 }
427 
428 void hci_request_sco_can_send_now_event(void){
429     hci_stack->sco_waiting_for_can_send_now = 1;
430     hci_notify_if_sco_can_send_now();
431 }
432 
433 // used for internal checks in l2cap.c
434 int hci_is_packet_buffer_reserved(void){
435     return hci_stack->hci_packet_buffer_reserved;
436 }
437 
438 // reserves outgoing packet buffer. @returns 1 if successful
439 int hci_reserve_packet_buffer(void){
440     if (hci_stack->hci_packet_buffer_reserved) {
441         log_error("hci_reserve_packet_buffer called but buffer already reserved");
442         return 0;
443     }
444     hci_stack->hci_packet_buffer_reserved = 1;
445     return 1;
446 }
447 
448 void hci_release_packet_buffer(void){
449     hci_stack->hci_packet_buffer_reserved = 0;
450 }
451 
452 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
453 static int hci_transport_synchronous(void){
454     return hci_stack->hci_transport->can_send_packet_now == NULL;
455 }
456 
457 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
458 
459     // 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);
460 
461     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
462     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
463     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
464         max_acl_data_packet_length = hci_stack->le_data_packets_length;
465     }
466 
467     // testing: reduce buffer to minimum
468     // max_acl_data_packet_length = 52;
469 
470     log_debug("hci_send_acl_packet_fragments entered");
471 
472     int err;
473     // multiple packets could be send on a synchronous HCI transport
474     while (1){
475 
476         log_debug("hci_send_acl_packet_fragments loop entered");
477 
478         // get current data
479         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
480         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
481         int more_fragments = 0;
482 
483         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
484         if (current_acl_data_packet_length > max_acl_data_packet_length){
485             more_fragments = 1;
486             current_acl_data_packet_length = max_acl_data_packet_length;
487         }
488 
489         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
490         if (acl_header_pos > 0){
491             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
492             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
493             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
494         }
495 
496         // update header len
497         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
498 
499         // count packet
500         connection->num_acl_packets_sent++;
501         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %u)", more_fragments);
502 
503         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
504         if (more_fragments){
505             // update start of next fragment to send
506             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
507         } else {
508             // done
509             hci_stack->acl_fragmentation_pos = 0;
510             hci_stack->acl_fragmentation_total_size = 0;
511         }
512 
513         // send packet
514         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
515         const int size = current_acl_data_packet_length + 4;
516         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
517         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
518 
519         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %u)", more_fragments);
520 
521         // done yet?
522         if (!more_fragments) break;
523 
524         // can send more?
525         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
526     }
527 
528     log_debug("hci_send_acl_packet_fragments loop over");
529 
530     // release buffer now for synchronous transport
531     if (hci_transport_synchronous()){
532         hci_release_packet_buffer();
533         // notify upper stack that it might be possible to send again
534         uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
535         hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
536     }
537 
538     return err;
539 }
540 
541 // pre: caller has reserved the packet buffer
542 int hci_send_acl_packet_buffer(int size){
543 
544     // log_info("hci_send_acl_packet_buffer size %u", size);
545 
546     if (!hci_stack->hci_packet_buffer_reserved) {
547         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
548         return 0;
549     }
550 
551     uint8_t * packet = hci_stack->hci_packet_buffer;
552     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
553 
554     // check for free places on Bluetooth module
555     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
556         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
557         hci_release_packet_buffer();
558         return BTSTACK_ACL_BUFFERS_FULL;
559     }
560 
561     hci_connection_t *connection = hci_connection_for_handle( con_handle);
562     if (!connection) {
563         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
564         hci_release_packet_buffer();
565         return 0;
566     }
567     hci_connection_timestamp(connection);
568 
569     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
570 
571     // setup data
572     hci_stack->acl_fragmentation_total_size = size;
573     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
574 
575     return hci_send_acl_packet_fragments(connection);
576 }
577 
578 // pre: caller has reserved the packet buffer
579 int hci_send_sco_packet_buffer(int size){
580 
581     // log_info("hci_send_acl_packet_buffer size %u", size);
582 
583     if (!hci_stack->hci_packet_buffer_reserved) {
584         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
585         return 0;
586     }
587 
588     uint8_t * packet = hci_stack->hci_packet_buffer;
589 
590     // skip checks in loopback mode
591     if (!hci_stack->loopback_mode){
592         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
593 
594         // check for free places on Bluetooth module
595         if (!hci_can_send_prepared_sco_packet_now()) {
596             log_error("hci_send_sco_packet_buffer called but no free ACL buffers on controller");
597             hci_release_packet_buffer();
598             return BTSTACK_ACL_BUFFERS_FULL;
599         }
600 
601         // track send packet in connection struct
602         hci_connection_t *connection = hci_connection_for_handle( con_handle);
603         if (!connection) {
604             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
605             hci_release_packet_buffer();
606             return 0;
607         }
608         connection->num_sco_packets_sent++;
609     }
610 
611     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
612     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
613 
614     if (hci_transport_synchronous()){
615         hci_release_packet_buffer();
616         // notify upper stack that it might be possible to send again
617         uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
618         hci_emit_event(&event[0], sizeof(event), 0);    // don't dump
619     }
620 
621     return err;
622 }
623 
624 static void acl_handler(uint8_t *packet, int size){
625 
626     // log_info("acl_handler: size %u", size);
627 
628     // get info
629     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
630     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
631     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
632     uint16_t acl_length         = READ_ACL_LENGTH(packet);
633 
634     // ignore non-registered handle
635     if (!conn){
636         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
637         return;
638     }
639 
640     // assert packet is complete
641     if (acl_length + 4 != size){
642         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
643         return;
644     }
645 
646     // update idle timestamp
647     hci_connection_timestamp(conn);
648 
649     // handle different packet types
650     switch (acl_flags & 0x03) {
651 
652         case 0x01: // continuation fragment
653 
654             // sanity checks
655             if (conn->acl_recombination_pos == 0) {
656                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
657                 return;
658             }
659             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
660                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
661                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
662                 conn->acl_recombination_pos = 0;
663                 return;
664             }
665 
666             // append fragment payload (header already stored)
667             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
668             conn->acl_recombination_pos += acl_length;
669 
670             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
671             //        conn->acl_recombination_pos, conn->acl_recombination_length);
672 
673             // forward complete L2CAP packet if complete.
674             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
675                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
676                 // reset recombination buffer
677                 conn->acl_recombination_length = 0;
678                 conn->acl_recombination_pos = 0;
679             }
680             break;
681 
682         case 0x02: { // first fragment
683 
684             // sanity check
685             if (conn->acl_recombination_pos) {
686                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
687                 conn->acl_recombination_pos = 0;
688             }
689 
690             // peek into L2CAP packet!
691             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
692 
693             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
694 
695             // compare fragment size to L2CAP packet size
696             if (acl_length >= l2cap_length + 4){
697                 // forward fragment as L2CAP packet
698                 hci_emit_acl_packet(packet, acl_length + 4);
699             } else {
700 
701                 if (acl_length > HCI_ACL_BUFFER_SIZE){
702                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
703                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
704                     return;
705                 }
706 
707                 // store first fragment and tweak acl length for complete package
708                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
709                 conn->acl_recombination_pos    = acl_length + 4;
710                 conn->acl_recombination_length = l2cap_length;
711                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
712             }
713             break;
714 
715         }
716         default:
717             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
718             return;
719     }
720 
721     // execute main loop
722     hci_run();
723 }
724 
725 static void hci_shutdown_connection(hci_connection_t *conn){
726     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
727 
728     btstack_run_loop_remove_timer(&conn->timeout);
729 
730     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
731     btstack_memory_hci_connection_free( conn );
732 
733     // now it's gone
734     hci_emit_nr_connections_changed();
735 }
736 
737 static const uint16_t packet_type_sizes[] = {
738     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
739     HCI_ACL_DH1_SIZE, 0, 0, 0,
740     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
741     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
742 };
743 static const uint8_t  packet_type_feature_requirement_bit[] = {
744      0, // 3 slot packets
745      1, // 5 slot packets
746     25, // EDR 2 mpbs
747     26, // EDR 3 mbps
748     39, // 3 slot EDR packts
749     40, // 5 slot EDR packet
750 };
751 static const uint16_t packet_type_feature_packet_mask[] = {
752     0x0f00, // 3 slot packets
753     0xf000, // 5 slot packets
754     0x1102, // EDR 2 mpbs
755     0x2204, // EDR 3 mbps
756     0x0300, // 3 slot EDR packts
757     0x3000, // 5 slot EDR packet
758 };
759 
760 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
761     // enable packet types based on size
762     uint16_t packet_types = 0;
763     unsigned int i;
764     for (i=0;i<16;i++){
765         if (packet_type_sizes[i] == 0) continue;
766         if (packet_type_sizes[i] <= buffer_size){
767             packet_types |= 1 << i;
768         }
769     }
770     // disable packet types due to missing local supported features
771     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
772         int bit_idx = packet_type_feature_requirement_bit[i];
773         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
774         if (feature_set) continue;
775         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
776         packet_types &= ~packet_type_feature_packet_mask[i];
777     }
778     // flip bits for "may not be used"
779     packet_types ^= 0x3306;
780     return packet_types;
781 }
782 
783 uint16_t hci_usable_acl_packet_types(void){
784     return hci_stack->packet_types;
785 }
786 
787 uint8_t* hci_get_outgoing_packet_buffer(void){
788     // hci packet buffer is >= acl data packet length
789     return hci_stack->hci_packet_buffer;
790 }
791 
792 uint16_t hci_max_acl_data_packet_length(void){
793     return hci_stack->acl_data_packet_length;
794 }
795 
796 int hci_extended_sco_link_supported(void){
797     // No. 31, byte 3, bit 7
798     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
799 }
800 
801 int hci_non_flushable_packet_boundary_flag_supported(void){
802     // No. 54, byte 6, bit 6
803     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
804 }
805 
806 static int gap_ssp_supported(void){
807     // No. 51, byte 6, bit 3
808     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
809 }
810 
811 static int hci_classic_supported(void){
812     // No. 37, byte 4, bit 5, = No BR/EDR Support
813     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
814 }
815 
816 static int hci_le_supported(void){
817 #ifdef ENABLE_BLE
818     // No. 37, byte 4, bit 6 = LE Supported (Controller)
819     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
820 #else
821     return 0;
822 #endif
823 }
824 
825 // get addr type and address used in advertisement packets
826 void gap_advertisements_get_address(uint8_t * addr_type, bd_addr_t  addr){
827     *addr_type = hci_stack->adv_addr_type;
828     if (hci_stack->adv_addr_type){
829         memcpy(addr, hci_stack->adv_address, 6);
830     } else {
831         memcpy(addr, hci_stack->local_bd_addr, 6);
832     }
833 }
834 
835 #ifdef ENABLE_BLE
836 void le_handle_advertisement_report(uint8_t *packet, int size){
837     int offset = 3;
838     int num_reports = packet[offset];
839     offset += 1;
840 
841     int i;
842     // log_info("HCI: handle adv report with num reports: %d", num_reports);
843     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
844     for (i=0; i<num_reports;i++){
845         uint8_t data_length = packet[offset + 8];
846         uint8_t event_size = 10 + data_length;
847         int pos = 0;
848         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
849         event[pos++] = event_size;
850         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
851         offset += 8;
852         pos += 8;
853         event[pos++] = packet[offset + 1 + data_length]; // rssi
854         event[pos++] = packet[offset++]; //data_length;
855         memcpy(&event[pos], &packet[offset], data_length);
856         pos += data_length;
857         offset += data_length + 1; // rssi
858         hci_emit_event(event, pos, 1);
859     }
860 }
861 #endif
862 
863 static uint32_t hci_transport_uart_get_main_baud_rate(void){
864     if (!hci_stack->config) return 0;
865     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
866     // Limit baud rate for Broadcom chipsets to 3 mbps
867     if (hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION && baud_rate > 3000000){
868         baud_rate = 3000000;
869     }
870     return baud_rate;
871 }
872 
873 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
874     switch (hci_stack->substate){
875         case HCI_INIT_W4_SEND_RESET:
876             log_info("Resend HCI Reset");
877             hci_stack->substate = HCI_INIT_SEND_RESET;
878             hci_stack->num_cmd_packets = 1;
879             hci_run();
880             break;
881         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
882             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
883             if (hci_stack->hci_transport->reset_link){
884                 hci_stack->hci_transport->reset_link();
885             }
886             // NOTE: explicit fallthrough to HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT
887         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
888             log_info("Resend HCI Reset - CSR Warm Boot");
889             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
890             hci_stack->num_cmd_packets = 1;
891             hci_run();
892             break;
893         case HCI_INIT_W4_SEND_BAUD_CHANGE:
894             if (hci_stack->hci_transport->set_baudrate){
895                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
896                 log_info("Local baud rate change to %"PRIu32"(timeout handler)", baud_rate);
897                 hci_stack->hci_transport->set_baudrate(baud_rate);
898             }
899             // For CSR, HCI Reset is sent on new baud rate
900             if (hci_stack->manufacturer == COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
901                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
902                 hci_run();
903             }
904             break;
905         default:
906             break;
907     }
908 }
909 
910 static void hci_initializing_next_state(void){
911     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
912 }
913 
914 // assumption: hci_can_send_command_packet_now() == true
915 static void hci_initializing_run(void){
916     log_info("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
917     switch (hci_stack->substate){
918         case HCI_INIT_SEND_RESET:
919             hci_state_reset();
920 
921 #ifndef HAVE_PLATFORM_IPHONE_OS
922             // prepare reset if command complete not received in 100ms
923             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
924             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
925             btstack_run_loop_add_timer(&hci_stack->timeout);
926 #endif
927             // send command
928             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
929             hci_send_cmd(&hci_reset);
930             break;
931         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
932             hci_send_cmd(&hci_read_local_version_information);
933             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
934             break;
935         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
936             hci_state_reset();
937             // prepare reset if command complete not received in 100ms
938             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
939             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
940             btstack_run_loop_add_timer(&hci_stack->timeout);
941             // send command
942             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
943             hci_send_cmd(&hci_reset);
944             break;
945         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
946             hci_state_reset();
947             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
948             hci_send_cmd(&hci_reset);
949             break;
950         case HCI_INIT_SEND_BAUD_CHANGE: {
951             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
952             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
953             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
954             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
955             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
956             // STLC25000D: baudrate change happens within 0.5 s after command was send,
957             // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
958             if (hci_stack->manufacturer == COMPANY_ID_ST_MICROELECTRONICS){
959                 btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
960                 btstack_run_loop_add_timer(&hci_stack->timeout);
961             }
962             break;
963         }
964         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
965             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
966             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
967             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
968             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
969             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
970             break;
971         }
972         case HCI_INIT_CUSTOM_INIT:
973             log_info("Custom init");
974             // Custom initialization
975             if (hci_stack->chipset && hci_stack->chipset->next_command){
976                 int valid_cmd = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
977                 if (valid_cmd){
978                     int size = 3 + hci_stack->hci_packet_buffer[2];
979                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
980                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
981                     switch (valid_cmd) {
982                         case 1:
983                         default:
984                             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
985                             break;
986                         case 2: // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
987                             log_info("CSR Warm Boot");
988                             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
989                             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
990                             btstack_run_loop_add_timer(&hci_stack->timeout);
991                             if (hci_stack->manufacturer == COMPANY_ID_CAMBRIDGE_SILICON_RADIO
992                                 && hci_stack->config
993                                 && hci_stack->chipset
994                                 // && hci_stack->chipset->set_baudrate_command -- there's no such command
995                                 && hci_stack->hci_transport->set_baudrate
996                                 && hci_transport_uart_get_main_baud_rate()){
997                                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
998                             } else {
999                                hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1000                             }
1001                             break;
1002                     }
1003                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1004                     break;
1005                 }
1006                 log_info("hci_run: init script done");
1007 
1008                 // Init script download causes baud rate to reset on Broadcom chipsets, restore UART baud rate if needed
1009                 if (hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION){
1010                     int need_baud_change = hci_stack->config
1011                         && hci_stack->chipset
1012                         && hci_stack->chipset->set_baudrate_command
1013                         && hci_stack->hci_transport->set_baudrate
1014                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1015                     if (need_baud_change) {
1016                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1017                         log_info("Local baud rate change to %"PRIu32" after init script (bcm)", baud_rate);
1018                         hci_stack->hci_transport->set_baudrate(baud_rate);
1019                     }
1020                 }
1021             }
1022             // otherwise continue
1023             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1024             hci_send_cmd(&hci_read_local_supported_commands);
1025             break;
1026         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1027             log_info("Resend hci_read_local_supported_commands after CSR Warm Boot double reset");
1028             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1029             hci_send_cmd(&hci_read_local_supported_commands);
1030             break;
1031         case HCI_INIT_SET_BD_ADDR:
1032             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1033             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1034             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1035             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1036             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1037             break;
1038         case HCI_INIT_READ_BD_ADDR:
1039             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1040             hci_send_cmd(&hci_read_bd_addr);
1041             break;
1042         case HCI_INIT_READ_BUFFER_SIZE:
1043             hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1044             hci_send_cmd(&hci_read_buffer_size);
1045             break;
1046         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1047             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1048             hci_send_cmd(&hci_read_local_supported_features);
1049             break;
1050         case HCI_INIT_SET_EVENT_MASK:
1051             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1052             if (hci_le_supported()){
1053                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1054             } else {
1055                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1056                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1057             }
1058             break;
1059         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1060             hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1061             hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1062             break;
1063         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1064             hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1065             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1066             break;
1067         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
1068             hci_stack->substate = HCI_INIT_W4_WRITE_CLASS_OF_DEVICE;
1069             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1070             break;
1071         case HCI_INIT_WRITE_LOCAL_NAME:
1072             hci_stack->substate = HCI_INIT_W4_WRITE_LOCAL_NAME;
1073             if (hci_stack->local_name){
1074                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
1075             } else {
1076                 char local_name[8+17+1];
1077                 // BTstack 11:22:33:44:55:66
1078                 memcpy(local_name, "BTstack ", 8);
1079                 memcpy(&local_name[8], bd_addr_to_str(hci_stack->local_bd_addr), 17);   // strlen(bd_addr_to_str(...)) = 17
1080                 local_name[8+17] = '\0';
1081                 log_info("---> Name %s", local_name);
1082                 hci_send_cmd(&hci_write_local_name, local_name);
1083             }
1084             break;
1085         case HCI_INIT_WRITE_EIR_DATA:
1086             hci_stack->substate = HCI_INIT_W4_WRITE_EIR_DATA;
1087             hci_send_cmd(&hci_write_extended_inquiry_response, 0, hci_stack->eir_data);
1088             break;
1089         case HCI_INIT_WRITE_INQUIRY_MODE:
1090             hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1091             hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1092             break;
1093         case HCI_INIT_WRITE_SCAN_ENABLE:
1094             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1095             hci_stack->substate = HCI_INIT_W4_WRITE_SCAN_ENABLE;
1096             break;
1097         // only sent if ENABLE_SCO_OVER_HCI is defined
1098         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1099             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1100             hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1101             break;
1102         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1103             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1104             hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1105             break;
1106 #ifdef ENABLE_BLE
1107         // LE INIT
1108         case HCI_INIT_LE_READ_BUFFER_SIZE:
1109             hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1110             hci_send_cmd(&hci_le_read_buffer_size);
1111             break;
1112         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1113             // LE Supported Host = 1, Simultaneous Host = 0
1114             hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1115             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1116             break;
1117         case HCI_INIT_READ_WHITE_LIST_SIZE:
1118             hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1119             hci_send_cmd(&hci_le_read_white_list_size);
1120             break;
1121         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1122             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
1123             hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1124             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
1125             break;
1126 #endif
1127         default:
1128             return;
1129     }
1130 }
1131 
1132 static void hci_init_done(void){
1133     // done. tell the app
1134     log_info("hci_init_done -> HCI_STATE_WORKING");
1135     hci_stack->state = HCI_STATE_WORKING;
1136     hci_emit_state();
1137     hci_run();
1138 }
1139 
1140 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
1141     uint8_t command_completed = 0;
1142 
1143     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1144         uint16_t opcode = little_endian_read_16(packet,3);
1145         if (opcode == hci_stack->last_cmd_opcode){
1146             command_completed = 1;
1147             log_info("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1148         } else {
1149             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1150         }
1151     }
1152 
1153     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1154         uint8_t  status = packet[2];
1155         uint16_t opcode = little_endian_read_16(packet,4);
1156         if (opcode == hci_stack->last_cmd_opcode){
1157             if (status){
1158                 command_completed = 1;
1159                 log_error("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1160             } else {
1161                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1162             }
1163         } else {
1164             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1165         }
1166     }
1167 
1168     // Vendor == CSR
1169     if (hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT && hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC){
1170         // TODO: track actual command
1171         command_completed = 1;
1172     }
1173 
1174     // Vendor == Toshiba
1175     if (hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE && hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC){
1176         // TODO: track actual command
1177         command_completed = 1;
1178     }
1179 
1180     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1181     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1182     //
1183     // HCI Reset
1184     // Timeout 100 ms
1185     // HCI Reset
1186     // Command Complete Reset
1187     // HCI Read Local Version Information
1188     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1189     // hang...
1190     //
1191     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1192     if (!command_completed
1193             && hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE
1194             && hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION){
1195 
1196         uint16_t opcode = little_endian_read_16(packet,3);
1197         if (opcode == hci_reset.opcode){
1198             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1199             return;
1200         }
1201     }
1202 
1203     // CSR & H5
1204     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1205     if (!command_completed
1206             && hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE
1207             && hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS){
1208 
1209         uint16_t opcode = little_endian_read_16(packet,3);
1210         if (opcode == hci_reset.opcode){
1211             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1212             return;
1213         }
1214     }
1215 
1216     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1217     // fix: Correct substate and behave as command below
1218     if (command_completed){
1219         switch (hci_stack->substate){
1220             case HCI_INIT_SEND_RESET:
1221                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1222                 break;
1223             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1224                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1225                 break;
1226             default:
1227                 break;
1228         }
1229     }
1230 
1231 
1232     if (!command_completed) return;
1233 
1234     int need_baud_change = hci_stack->config
1235                         && hci_stack->chipset
1236                         && hci_stack->chipset->set_baudrate_command
1237                         && hci_stack->hci_transport->set_baudrate
1238                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1239 
1240     int need_addr_change = hci_stack->custom_bd_addr_set
1241                         && hci_stack->chipset
1242                         && hci_stack->chipset->set_bd_addr_command;
1243 
1244     switch(hci_stack->substate){
1245         case HCI_INIT_SEND_RESET:
1246             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1247             // fix: just correct substate and behave as command below
1248             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1249             btstack_run_loop_remove_timer(&hci_stack->timeout);
1250             break;
1251         case HCI_INIT_W4_SEND_RESET:
1252             btstack_run_loop_remove_timer(&hci_stack->timeout);
1253             break;
1254         case HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION:
1255             log_info("Received local version info, need baud change %u", need_baud_change);
1256             if (need_baud_change){
1257                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE;
1258                 return;
1259             }
1260             // skip baud change
1261             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1262             return;
1263         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1264             // for STLC2500D, baud rate change already happened.
1265             // for others, baud rate gets changed now
1266             if ((hci_stack->manufacturer != COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1267                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1268                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change)", baud_rate);
1269                 hci_stack->hci_transport->set_baudrate(baud_rate);
1270             }
1271             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1272             return;
1273         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1274             btstack_run_loop_remove_timer(&hci_stack->timeout);
1275             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1276             return;
1277         case HCI_INIT_W4_CUSTOM_INIT:
1278             // repeat custom init
1279             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1280             return;
1281         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1282             if (need_baud_change && hci_stack->manufacturer == COMPANY_ID_BROADCOM_CORPORATION){
1283                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1284                 return;
1285             }
1286             if (need_addr_change){
1287                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1288                 return;
1289             }
1290             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1291             return;
1292         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1293             if (need_baud_change){
1294                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1295                 log_info("Local baud rate change to %"PRIu32"(w4_send_baud_change_bcm))", baud_rate);
1296                 hci_stack->hci_transport->set_baudrate(baud_rate);
1297             }
1298             if (need_addr_change){
1299                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1300                 return;
1301             }
1302             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1303             return;
1304         case HCI_INIT_W4_SET_BD_ADDR:
1305             // for STLC2500D, bd addr change only gets active after sending reset command
1306             if (hci_stack->manufacturer == COMPANY_ID_ST_MICROELECTRONICS){
1307                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1308                 return;
1309             }
1310             // skipping st warm boot
1311             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1312             return;
1313         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
1314             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1315             return;
1316         case HCI_INIT_W4_READ_BD_ADDR:
1317             // only read buffer size if supported
1318             if (hci_stack->local_supported_commands[0] & 0x01) {
1319                 hci_stack->substate = HCI_INIT_READ_BUFFER_SIZE;
1320                 return;
1321             }
1322             // skipping read buffer size
1323             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES;
1324             return;
1325         case HCI_INIT_W4_SET_EVENT_MASK:
1326             // skip Classic init commands for LE only chipsets
1327             if (!hci_classic_supported()){
1328                 if (hci_le_supported()){
1329                     hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE; // skip all classic command
1330                     return;
1331                 } else {
1332                     log_error("Neither BR/EDR nor LE supported");
1333                     hci_init_done();
1334                     return;
1335                 }
1336             }
1337             if (!gap_ssp_supported()){
1338                 hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
1339                 return;
1340             }
1341             break;
1342         case HCI_INIT_W4_WRITE_PAGE_TIMEOUT:
1343             break;
1344         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
1345             // skip write le host if not supported (e.g. on LE only EM9301)
1346             if (hci_stack->local_supported_commands[0] & 0x02) break;
1347             hci_stack->substate = HCI_INIT_LE_SET_SCAN_PARAMETERS;
1348             return;
1349         case HCI_INIT_W4_WRITE_LOCAL_NAME:
1350             // skip write eir data if no eir data set
1351             if (hci_stack->eir_data) break;
1352             hci_stack->substate = HCI_INIT_WRITE_INQUIRY_MODE;
1353             return;
1354 
1355 #ifdef ENABLE_SCO_OVER_HCI
1356         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1357         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1358             break;
1359         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1360             if (!hci_le_supported()){
1361                 // SKIP LE init for Classic only configuration
1362                 hci_init_done();
1363                 return;
1364             }
1365             break;
1366 #else
1367         case HCI_INIT_W4_WRITE_SCAN_ENABLE:
1368             if (!hci_le_supported()){
1369                 // SKIP LE init for Classic only configuration
1370                 hci_init_done();
1371                 return;
1372             }
1373 #endif
1374             break;
1375         // Response to command before init done state -> init done
1376         case (HCI_INIT_DONE-1):
1377             hci_init_done();
1378             return;
1379 
1380         default:
1381             break;
1382     }
1383     hci_initializing_next_state();
1384 }
1385 
1386 static void event_handler(uint8_t *packet, int size){
1387 
1388     uint16_t event_length = packet[1];
1389 
1390     // assert packet is complete
1391     if (size != event_length + 2){
1392         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
1393         return;
1394     }
1395 
1396     bd_addr_t addr;
1397     bd_addr_type_t addr_type;
1398     uint8_t link_type;
1399     hci_con_handle_t handle;
1400     hci_connection_t * conn;
1401     int i;
1402 
1403     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
1404 
1405     switch (hci_event_packet_get_type(packet)) {
1406 
1407         case HCI_EVENT_COMMAND_COMPLETE:
1408             // get num cmd packets
1409             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
1410             hci_stack->num_cmd_packets = packet[2];
1411 
1412             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_buffer_size)){
1413                 // from offset 5
1414                 // status
1415                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
1416                 hci_stack->acl_data_packet_length = little_endian_read_16(packet, 6);
1417                 hci_stack->sco_data_packet_length = packet[8];
1418                 hci_stack->acl_packets_total_num  = little_endian_read_16(packet, 9);
1419                 hci_stack->sco_packets_total_num  = little_endian_read_16(packet, 11);
1420 
1421                 if (hci_stack->state == HCI_STATE_INITIALIZING){
1422                     // determine usable ACL payload size
1423                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
1424                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1425                     }
1426                     log_info("hci_read_buffer_size: acl used size %u, count %u / sco size %u, count %u",
1427                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
1428                              hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
1429                 }
1430             }
1431 #ifdef ENABLE_BLE
1432             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_buffer_size)){
1433                 hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
1434                 hci_stack->le_acl_packets_total_num  = packet[8];
1435                     // determine usable ACL payload size
1436                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1437                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1438                     }
1439                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1440             }
1441             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_read_white_list_size)){
1442                 hci_stack->le_whitelist_capacity = little_endian_read_16(packet, 6);
1443                 log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
1444             }
1445 #endif
1446             // Dump local address
1447             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)) {
1448                 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1],
1449 				hci_stack->local_bd_addr);
1450                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1451                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1452                 if (hci_stack->link_key_db){
1453                     hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
1454                 }
1455             }
1456             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
1457                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1458             }
1459             // Note: HCI init checks
1460             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_features)){
1461                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1462 
1463                 // determine usable ACL packet types based on host buffer size and supported features
1464                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1465                 log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
1466 
1467                 // Classic/LE
1468                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1469             }
1470             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_version_information)){
1471                 // hci_stack->hci_version    = little_endian_read_16(packet, 4);
1472                 // hci_stack->hci_revision   = little_endian_read_16(packet, 6);
1473                 // hci_stack->lmp_version    = little_endian_read_16(packet, 8);
1474                 hci_stack->manufacturer   = little_endian_read_16(packet, 10);
1475                 // hci_stack->lmp_subversion = little_endian_read_16(packet, 12);
1476                 log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
1477                 // notify app
1478                 if (hci_stack->local_version_information_callback){
1479                     hci_stack->local_version_information_callback(packet);
1480                 }
1481             }
1482             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){
1483                 hci_stack->local_supported_commands[0] =
1484                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+14] & 0X80) >> 7 |  // Octet 14, bit 7
1485                     (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+24] & 0x40) >> 5;   // Octet 24, bit 6
1486             }
1487             if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_synchronous_flow_control_enable)){
1488                 if (packet[5] == 0){
1489                     hci_stack->synchronous_flow_control_enabled = 1;
1490                 }
1491             }
1492             break;
1493 
1494         case HCI_EVENT_COMMAND_STATUS:
1495             // get num cmd packets
1496             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1497             hci_stack->num_cmd_packets = packet[3];
1498             break;
1499 
1500         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1501             int offset = 3;
1502             for (i=0; i<packet[2];i++){
1503                 handle = little_endian_read_16(packet, offset);
1504                 offset += 2;
1505                 uint16_t num_packets = little_endian_read_16(packet, offset);
1506                 offset += 2;
1507 
1508                 conn = hci_connection_for_handle(handle);
1509                 if (!conn){
1510                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1511                     continue;
1512                 }
1513 
1514                 if (conn->address_type == BD_ADDR_TYPE_SCO){
1515                     if (conn->num_sco_packets_sent >= num_packets){
1516                         conn->num_sco_packets_sent -= num_packets;
1517                     } else {
1518                         log_error("hci_number_completed_packets, more sco slots freed then sent.");
1519                         conn->num_sco_packets_sent = 0;
1520                     }
1521                     hci_notify_if_sco_can_send_now();
1522                 } else {
1523                     if (conn->num_acl_packets_sent >= num_packets){
1524                         conn->num_acl_packets_sent -= num_packets;
1525                     } else {
1526                         log_error("hci_number_completed_packets, more acl slots freed then sent.");
1527                         conn->num_acl_packets_sent = 0;
1528                     }
1529                 }
1530                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1531             }
1532             break;
1533         }
1534         case HCI_EVENT_CONNECTION_REQUEST:
1535             reverse_bd_addr(&packet[2], addr);
1536             // TODO: eval COD 8-10
1537             link_type = packet[11];
1538             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1539             addr_type = link_type == 1 ? BD_ADDR_TYPE_CLASSIC : BD_ADDR_TYPE_SCO;
1540             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1541             if (!conn) {
1542                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1543             }
1544             if (!conn) {
1545                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1546                 hci_stack->decline_reason = 0x0d;
1547                 bd_addr_copy(hci_stack->decline_addr, addr);
1548                 break;
1549             }
1550             conn->role  = HCI_ROLE_SLAVE;
1551             conn->state = RECEIVED_CONNECTION_REQUEST;
1552             // store info about eSCO
1553             if (link_type == 0x02){
1554                 conn->remote_supported_feature_eSCO = 1;
1555             }
1556             hci_run();
1557             break;
1558 
1559         case HCI_EVENT_CONNECTION_COMPLETE:
1560             // Connection management
1561             reverse_bd_addr(&packet[5], addr);
1562             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1563             addr_type = BD_ADDR_TYPE_CLASSIC;
1564             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1565             if (conn) {
1566                 if (!packet[2]){
1567                     conn->state = OPEN;
1568                     conn->con_handle = little_endian_read_16(packet, 3);
1569                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1570 
1571                     // restart timer
1572                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1573                     btstack_run_loop_add_timer(&conn->timeout);
1574 
1575                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1576 
1577                     hci_emit_nr_connections_changed();
1578                 } else {
1579                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1580                     uint8_t status = packet[2];
1581                     bd_addr_t bd_address;
1582                     memcpy(&bd_address, conn->address, 6);
1583 
1584                     // connection failed, remove entry
1585                     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1586                     btstack_memory_hci_connection_free( conn );
1587 
1588                     // notify client if dedicated bonding
1589                     if (notify_dedicated_bonding_failed){
1590                         log_info("hci notify_dedicated_bonding_failed");
1591                         hci_emit_dedicated_bonding_result(bd_address, status);
1592                     }
1593 
1594                     // if authentication error, also delete link key
1595                     if (packet[2] == 0x05) {
1596                         gap_drop_link_key_for_bd_addr(addr);
1597                     }
1598                 }
1599             }
1600             break;
1601 
1602         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
1603             reverse_bd_addr(&packet[5], addr);
1604             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1605             if (packet[2]){
1606                 // connection failed
1607                 break;
1608             }
1609             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1610             if (!conn) {
1611                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1612             }
1613             if (!conn) {
1614                 break;
1615             }
1616             conn->state = OPEN;
1617             conn->con_handle = little_endian_read_16(packet, 3);
1618             break;
1619 
1620         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1621             handle = little_endian_read_16(packet, 3);
1622             conn = hci_connection_for_handle(handle);
1623             if (!conn) break;
1624             if (!packet[2]){
1625                 uint8_t * features = &packet[5];
1626                 if (features[6] & (1 << 3)){
1627                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1628                 }
1629                 if (features[3] & (1<<7)){
1630                     conn->remote_supported_feature_eSCO = 1;
1631                 }
1632             }
1633             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1634             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x, eSCO %u", conn->bonding_flags, conn->remote_supported_feature_eSCO);
1635             if (conn->bonding_flags & BONDING_DEDICATED){
1636                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1637             }
1638             break;
1639 
1640         case HCI_EVENT_LINK_KEY_REQUEST:
1641             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1642             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1643             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1644             if (hci_stack->bondable && !hci_stack->link_key_db) break;
1645             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1646             hci_run();
1647             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1648             return;
1649 
1650         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1651             reverse_bd_addr(&packet[2], addr);
1652             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1653             if (!conn) break;
1654             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1655             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1656             // Change Connection Encryption keeps link key type
1657             if (link_key_type != CHANGED_COMBINATION_KEY){
1658                 conn->link_key_type = link_key_type;
1659             }
1660             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
1661             // still forward event to allow dismiss of pairing dialog
1662             break;
1663         }
1664 
1665         case HCI_EVENT_PIN_CODE_REQUEST:
1666             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1667             // non-bondable mode: pin code negative reply will be sent
1668             if (!hci_stack->bondable){
1669                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1670                 hci_run();
1671                 return;
1672             }
1673             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1674             if (!hci_stack->link_key_db) break;
1675             hci_event_pin_code_request_get_bd_addr(packet, addr);
1676             hci_stack->link_key_db->delete_link_key(addr);
1677             break;
1678 
1679         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1680             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1681             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1682             break;
1683 
1684         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1685             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1686             if (!hci_stack->ssp_auto_accept) break;
1687             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1688             break;
1689 
1690         case HCI_EVENT_USER_PASSKEY_REQUEST:
1691             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1692             if (!hci_stack->ssp_auto_accept) break;
1693             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1694             break;
1695 
1696         case HCI_EVENT_ENCRYPTION_CHANGE:
1697             handle = little_endian_read_16(packet, 3);
1698             conn = hci_connection_for_handle(handle);
1699             if (!conn) break;
1700             if (packet[2] == 0) {
1701                 if (packet[5]){
1702                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1703                 } else {
1704                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1705                 }
1706             }
1707             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1708             break;
1709 
1710         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1711             handle = little_endian_read_16(packet, 3);
1712             conn = hci_connection_for_handle(handle);
1713             if (!conn) break;
1714 
1715             // dedicated bonding: send result and disconnect
1716             if (conn->bonding_flags & BONDING_DEDICATED){
1717                 conn->bonding_flags &= ~BONDING_DEDICATED;
1718                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1719                 conn->bonding_status = packet[2];
1720                 break;
1721             }
1722 
1723             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1724                 // link key sufficient for requested security
1725                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1726                 break;
1727             }
1728             // not enough
1729             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1730             break;
1731 
1732         // HCI_EVENT_DISCONNECTION_COMPLETE
1733         // has been split, to first notify stack before shutting connection down
1734         // see end of function, too.
1735         case HCI_EVENT_DISCONNECTION_COMPLETE:
1736             if (packet[2]) break;   // status != 0
1737             handle = little_endian_read_16(packet, 3);
1738             // drop outgoing ACL fragments if it is for closed connection
1739             if (hci_stack->acl_fragmentation_total_size > 0) {
1740                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
1741                     log_info("hci: drop fragmented ACL data for closed connection");
1742                      hci_stack->acl_fragmentation_total_size = 0;
1743                      hci_stack->acl_fragmentation_pos = 0;
1744                 }
1745             }
1746             // re-enable advertisements for le connections if active
1747             conn = hci_connection_for_handle(handle);
1748             if (!conn) break;
1749             if (hci_is_le_connection(conn) && hci_stack->le_advertisements_enabled){
1750                 hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
1751             }
1752             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1753             break;
1754 
1755         case HCI_EVENT_HARDWARE_ERROR:
1756             log_error("Hardware Error: 0x%02x", packet[2]);
1757             if (hci_stack->hardware_error_callback){
1758                 (*hci_stack->hardware_error_callback)(packet[2]);
1759             } else {
1760                 // if no special requests, just reboot stack
1761                 hci_power_control_off();
1762                 hci_power_control_on();
1763             }
1764             break;
1765 
1766         case HCI_EVENT_ROLE_CHANGE:
1767             if (packet[2]) break;   // status != 0
1768             handle = little_endian_read_16(packet, 3);
1769             conn = hci_connection_for_handle(handle);
1770             if (!conn) break;       // no conn
1771             conn->role = packet[9];
1772             break;
1773 
1774         case HCI_EVENT_TRANSPORT_PACKET_SENT:
1775             // release packet buffer only for asynchronous transport and if there are not further fragements
1776             if (hci_transport_synchronous()) {
1777                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
1778                 return; // instead of break: to avoid re-entering hci_run()
1779             }
1780             if (hci_stack->acl_fragmentation_total_size) break;
1781             hci_release_packet_buffer();
1782 
1783             // L2CAP receives this event via the hci_emit_event below
1784 
1785             // For SCO, we do the can_send_now_check here
1786             hci_notify_if_sco_can_send_now();
1787             break;
1788 
1789         case HCI_EVENT_SCO_CAN_SEND_NOW:
1790             // For SCO, we do the can_send_now_check here
1791             hci_notify_if_sco_can_send_now();
1792             return;
1793 
1794 #ifdef ENABLE_BLE
1795         case HCI_EVENT_LE_META:
1796             switch (packet[2]){
1797                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1798                     // log_info("advertising report received");
1799                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1800                     le_handle_advertisement_report(packet, size);
1801                     break;
1802                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1803                     // Connection management
1804                     reverse_bd_addr(&packet[8], addr);
1805                     addr_type = (bd_addr_type_t)packet[7];
1806                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1807                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1808                     // if auto-connect, remove from whitelist in both roles
1809                     if (hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST){
1810                         hci_remove_from_whitelist(addr_type, addr);
1811                     }
1812                     // handle error: error is reported only to the initiator -> outgoing connection
1813                     if (packet[3]){
1814                         // outgoing connection establishment is done
1815                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1816                         // remove entry
1817                         if (conn){
1818                             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1819                             btstack_memory_hci_connection_free( conn );
1820                         }
1821                         break;
1822                     }
1823                     // on success, both hosts receive connection complete event
1824                     if (packet[6] == HCI_ROLE_MASTER){
1825                         // if we're master, it was an outgoing connection and we're done with it
1826                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1827                     } else {
1828                         // if we're slave, it was an incoming connection, advertisements have stopped
1829                         hci_stack->le_advertisements_active = 0;
1830                     }
1831                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1832                     if (!conn){
1833                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1834                     }
1835                     // no memory, sorry.
1836                     if (!conn){
1837                         break;
1838                     }
1839 
1840                     conn->state = OPEN;
1841                     conn->role  = packet[6];
1842                     conn->con_handle = little_endian_read_16(packet, 4);
1843 
1844                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1845 
1846                     // restart timer
1847                     // btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1848                     // btstack_run_loop_add_timer(&conn->timeout);
1849 
1850                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1851 
1852                     hci_emit_nr_connections_changed();
1853                     break;
1854 
1855             // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
1856 
1857                 default:
1858                     break;
1859             }
1860             break;
1861 #endif
1862         default:
1863             break;
1864     }
1865 
1866     // handle BT initialization
1867     if (hci_stack->state == HCI_STATE_INITIALIZING){
1868         hci_initializing_event_handler(packet, size);
1869     }
1870 
1871     // help with BT sleep
1872     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1873         && hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE
1874         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)){
1875         hci_initializing_next_state();
1876     }
1877 
1878     // notify upper stack
1879 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
1880 
1881     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1882     if (hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE){
1883         if (!packet[2]){
1884             handle = little_endian_read_16(packet, 3);
1885             hci_connection_t * aConn = hci_connection_for_handle(handle);
1886             if (aConn) {
1887                 uint8_t status = aConn->bonding_status;
1888                 uint16_t flags = aConn->bonding_flags;
1889                 bd_addr_t bd_address;
1890                 memcpy(&bd_address, aConn->address, 6);
1891                 hci_shutdown_connection(aConn);
1892                 // connection struct is gone, don't access anymore
1893                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1894                     hci_emit_dedicated_bonding_result(bd_address, status);
1895                 }
1896             }
1897         }
1898     }
1899 
1900 	// execute main loop
1901 	hci_run();
1902 }
1903 
1904 static void sco_handler(uint8_t * packet, uint16_t size){
1905     if (!hci_stack->sco_packet_handler) return;
1906     hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
1907 }
1908 
1909 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1910     hci_dump_packet(packet_type, 1, packet, size);
1911     switch (packet_type) {
1912         case HCI_EVENT_PACKET:
1913             event_handler(packet, size);
1914             break;
1915         case HCI_ACL_DATA_PACKET:
1916             acl_handler(packet, size);
1917             break;
1918         case HCI_SCO_DATA_PACKET:
1919             sco_handler(packet, size);
1920         default:
1921             break;
1922     }
1923 }
1924 
1925 /**
1926  * @brief Add event packet handler.
1927  */
1928 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
1929     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
1930 }
1931 
1932 
1933 /** Register HCI packet handlers */
1934 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
1935     hci_stack->acl_packet_handler = handler;
1936 }
1937 
1938 /**
1939  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
1940  */
1941 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
1942     hci_stack->sco_packet_handler = handler;
1943 }
1944 
1945 static void hci_state_reset(void){
1946     // no connections yet
1947     hci_stack->connections = NULL;
1948 
1949     // keep discoverable/connectable as this has been requested by the client(s)
1950     // hci_stack->discoverable = 0;
1951     // hci_stack->connectable = 0;
1952     // hci_stack->bondable = 1;
1953 
1954     // buffer is free
1955     hci_stack->hci_packet_buffer_reserved = 0;
1956 
1957     // no pending cmds
1958     hci_stack->decline_reason = 0;
1959     hci_stack->new_scan_enable_value = 0xff;
1960 
1961     // LE
1962     hci_stack->adv_addr_type = 0;
1963     memset(hci_stack->adv_address, 0, 6);
1964     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1965     hci_stack->le_scan_type = 0xff;
1966     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
1967     hci_stack->le_whitelist = 0;
1968     hci_stack->le_whitelist_capacity = 0;
1969     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
1970     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
1971     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
1972     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
1973     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
1974     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
1975 }
1976 
1977 /**
1978  * @brief Configure Bluetooth hardware control. Has to be called before power on.
1979  */
1980 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
1981     // store and open remote device db
1982     hci_stack->link_key_db = link_key_db;
1983     if (hci_stack->link_key_db) {
1984         hci_stack->link_key_db->open();
1985     }
1986 }
1987 
1988 void hci_init(const hci_transport_t *transport, const void *config){
1989 
1990 #ifdef HAVE_MALLOC
1991     if (!hci_stack) {
1992         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1993     }
1994 #else
1995     hci_stack = &hci_stack_static;
1996 #endif
1997     memset(hci_stack, 0, sizeof(hci_stack_t));
1998 
1999     // reference to use transport layer implementation
2000     hci_stack->hci_transport = transport;
2001 
2002     // reference to used config
2003     hci_stack->config = config;
2004 
2005     // setup pointer for outgoing packet buffer
2006     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
2007 
2008     // max acl payload size defined in config.h
2009     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
2010 
2011     // register packet handlers with transport
2012     transport->register_packet_handler(&packet_handler);
2013 
2014     hci_stack->state = HCI_STATE_OFF;
2015 
2016     // class of device
2017     hci_stack->class_of_device = 0x007a020c; // Smartphone
2018 
2019     // bondable by default
2020     hci_stack->bondable = 1;
2021 
2022     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
2023     hci_stack->ssp_enable = 1;
2024     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
2025     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
2026     hci_stack->ssp_auto_accept = 1;
2027 
2028     // voice setting - signed 8 bit pcm data with CVSD over the air
2029     hci_stack->sco_voice_setting = 0x40;
2030 
2031     hci_state_reset();
2032 }
2033 
2034 /**
2035  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
2036  */
2037 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
2038     hci_stack->chipset = chipset_driver;
2039 
2040     // reset chipset driver - init is also called on power_up
2041     if (hci_stack->chipset && hci_stack->chipset->init){
2042         hci_stack->chipset->init(hci_stack->config);
2043     }
2044 }
2045 
2046 /**
2047  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
2048  */
2049 void hci_set_control(const btstack_control_t *hardware_control){
2050     // references to used control implementation
2051     hci_stack->control = hardware_control;
2052     // init with transport config
2053     hardware_control->init(hci_stack->config);
2054 }
2055 
2056 void hci_close(void){
2057     // close remote device db
2058     if (hci_stack->link_key_db) {
2059         hci_stack->link_key_db->close();
2060     }
2061 
2062     btstack_linked_list_iterator_t lit;
2063     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
2064     while (btstack_linked_list_iterator_has_next(&lit)){
2065         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
2066         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
2067         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
2068         hci_shutdown_connection(connection);
2069     }
2070 
2071     hci_power_control(HCI_POWER_OFF);
2072 
2073 #ifdef HAVE_MALLOC
2074     free(hci_stack);
2075 #endif
2076     hci_stack = NULL;
2077 }
2078 
2079 void gap_set_class_of_device(uint32_t class_of_device){
2080     hci_stack->class_of_device = class_of_device;
2081 }
2082 
2083 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
2084 void hci_set_bd_addr(bd_addr_t addr){
2085     memcpy(hci_stack->custom_bd_addr, addr, 6);
2086     hci_stack->custom_bd_addr_set = 1;
2087 }
2088 
2089 void hci_disable_l2cap_timeout_check(void){
2090     disable_l2cap_timeouts = 1;
2091 }
2092 // State-Module-Driver overview
2093 // state                    module  low-level
2094 // HCI_STATE_OFF             off      close
2095 // HCI_STATE_INITIALIZING,   on       open
2096 // HCI_STATE_WORKING,        on       open
2097 // HCI_STATE_HALTING,        on       open
2098 // HCI_STATE_SLEEPING,    off/sleep   close
2099 // HCI_STATE_FALLING_ASLEEP  on       open
2100 
2101 static int hci_power_control_on(void){
2102 
2103     // power on
2104     int err = 0;
2105     if (hci_stack->control && hci_stack->control->on){
2106         err = (*hci_stack->control->on)();
2107     }
2108     if (err){
2109         log_error( "POWER_ON failed");
2110         hci_emit_hci_open_failed();
2111         return err;
2112     }
2113 
2114     // int chipset driver
2115     if (hci_stack->chipset && hci_stack->chipset->init){
2116         hci_stack->chipset->init(hci_stack->config);
2117     }
2118 
2119     // init transport
2120     if (hci_stack->hci_transport->init){
2121         hci_stack->hci_transport->init(hci_stack->config);
2122     }
2123 
2124     // open transport
2125     err = hci_stack->hci_transport->open();
2126     if (err){
2127         log_error( "HCI_INIT failed, turning Bluetooth off again");
2128         if (hci_stack->control && hci_stack->control->off){
2129             (*hci_stack->control->off)();
2130         }
2131         hci_emit_hci_open_failed();
2132         return err;
2133     }
2134     return 0;
2135 }
2136 
2137 static void hci_power_control_off(void){
2138 
2139     log_info("hci_power_control_off");
2140 
2141     // close low-level device
2142     hci_stack->hci_transport->close();
2143 
2144     log_info("hci_power_control_off - hci_transport closed");
2145 
2146     // power off
2147     if (hci_stack->control && hci_stack->control->off){
2148         (*hci_stack->control->off)();
2149     }
2150 
2151     log_info("hci_power_control_off - control closed");
2152 
2153     hci_stack->state = HCI_STATE_OFF;
2154 }
2155 
2156 static void hci_power_control_sleep(void){
2157 
2158     log_info("hci_power_control_sleep");
2159 
2160 #if 0
2161     // don't close serial port during sleep
2162 
2163     // close low-level device
2164     hci_stack->hci_transport->close(hci_stack->config);
2165 #endif
2166 
2167     // sleep mode
2168     if (hci_stack->control && hci_stack->control->sleep){
2169         (*hci_stack->control->sleep)();
2170     }
2171 
2172     hci_stack->state = HCI_STATE_SLEEPING;
2173 }
2174 
2175 static int hci_power_control_wake(void){
2176 
2177     log_info("hci_power_control_wake");
2178 
2179     // wake on
2180     if (hci_stack->control && hci_stack->control->wake){
2181         (*hci_stack->control->wake)();
2182     }
2183 
2184 #if 0
2185     // open low-level device
2186     int err = hci_stack->hci_transport->open(hci_stack->config);
2187     if (err){
2188         log_error( "HCI_INIT failed, turning Bluetooth off again");
2189         if (hci_stack->control && hci_stack->control->off){
2190             (*hci_stack->control->off)();
2191         }
2192         hci_emit_hci_open_failed();
2193         return err;
2194     }
2195 #endif
2196 
2197     return 0;
2198 }
2199 
2200 static void hci_power_transition_to_initializing(void){
2201     // set up state machine
2202     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
2203     hci_stack->hci_packet_buffer_reserved = 0;
2204     hci_stack->state = HCI_STATE_INITIALIZING;
2205     hci_stack->substate = HCI_INIT_SEND_RESET;
2206 }
2207 
2208 int hci_power_control(HCI_POWER_MODE power_mode){
2209 
2210     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
2211 
2212     int err = 0;
2213     switch (hci_stack->state){
2214 
2215         case HCI_STATE_OFF:
2216             switch (power_mode){
2217                 case HCI_POWER_ON:
2218                     err = hci_power_control_on();
2219                     if (err) {
2220                         log_error("hci_power_control_on() error %u", err);
2221                         return err;
2222                     }
2223                     hci_power_transition_to_initializing();
2224                     break;
2225                 case HCI_POWER_OFF:
2226                     // do nothing
2227                     break;
2228                 case HCI_POWER_SLEEP:
2229                     // do nothing (with SLEEP == OFF)
2230                     break;
2231             }
2232             break;
2233 
2234         case HCI_STATE_INITIALIZING:
2235             switch (power_mode){
2236                 case HCI_POWER_ON:
2237                     // do nothing
2238                     break;
2239                 case HCI_POWER_OFF:
2240                     // no connections yet, just turn it off
2241                     hci_power_control_off();
2242                     break;
2243                 case HCI_POWER_SLEEP:
2244                     // no connections yet, just turn it off
2245                     hci_power_control_sleep();
2246                     break;
2247             }
2248             break;
2249 
2250         case HCI_STATE_WORKING:
2251             switch (power_mode){
2252                 case HCI_POWER_ON:
2253                     // do nothing
2254                     break;
2255                 case HCI_POWER_OFF:
2256                     // see hci_run
2257                     hci_stack->state = HCI_STATE_HALTING;
2258                     break;
2259                 case HCI_POWER_SLEEP:
2260                     // see hci_run
2261                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
2262                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
2263                     break;
2264             }
2265             break;
2266 
2267         case HCI_STATE_HALTING:
2268             switch (power_mode){
2269                 case HCI_POWER_ON:
2270                     hci_power_transition_to_initializing();
2271                     break;
2272                 case HCI_POWER_OFF:
2273                     // do nothing
2274                     break;
2275                 case HCI_POWER_SLEEP:
2276                     // see hci_run
2277                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
2278                     hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
2279                     break;
2280             }
2281             break;
2282 
2283         case HCI_STATE_FALLING_ASLEEP:
2284             switch (power_mode){
2285                 case HCI_POWER_ON:
2286 
2287 #ifdef HAVE_PLATFORM_IPHONE_OS
2288                     // nothing to do, if H4 supports power management
2289                     if (btstack_control_iphone_power_management_enabled()){
2290                         hci_stack->state = HCI_STATE_INITIALIZING;
2291                         hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE;   // init after sleep
2292                         break;
2293                     }
2294 #endif
2295                     hci_power_transition_to_initializing();
2296                     break;
2297                 case HCI_POWER_OFF:
2298                     // see hci_run
2299                     hci_stack->state = HCI_STATE_HALTING;
2300                     break;
2301                 case HCI_POWER_SLEEP:
2302                     // do nothing
2303                     break;
2304             }
2305             break;
2306 
2307         case HCI_STATE_SLEEPING:
2308             switch (power_mode){
2309                 case HCI_POWER_ON:
2310 
2311 #ifdef HAVE_PLATFORM_IPHONE_OS
2312                     // nothing to do, if H4 supports power management
2313                     if (btstack_control_iphone_power_management_enabled()){
2314                         hci_stack->state = HCI_STATE_INITIALIZING;
2315                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
2316                         hci_update_scan_enable();
2317                         break;
2318                     }
2319 #endif
2320                     err = hci_power_control_wake();
2321                     if (err) return err;
2322                     hci_power_transition_to_initializing();
2323                     break;
2324                 case HCI_POWER_OFF:
2325                     hci_stack->state = HCI_STATE_HALTING;
2326                     break;
2327                 case HCI_POWER_SLEEP:
2328                     // do nothing
2329                     break;
2330             }
2331             break;
2332     }
2333 
2334     // create internal event
2335 	hci_emit_state();
2336 
2337 	// trigger next/first action
2338 	hci_run();
2339 
2340     return 0;
2341 }
2342 
2343 static void hci_update_scan_enable(void){
2344     // 2 = page scan, 1 = inq scan
2345     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
2346     hci_run();
2347 }
2348 
2349 void gap_discoverable_control(uint8_t enable){
2350     if (enable) enable = 1; // normalize argument
2351 
2352     if (hci_stack->discoverable == enable){
2353         hci_emit_discoverable_enabled(hci_stack->discoverable);
2354         return;
2355     }
2356 
2357     hci_stack->discoverable = enable;
2358     hci_update_scan_enable();
2359 }
2360 
2361 void gap_connectable_control(uint8_t enable){
2362     if (enable) enable = 1; // normalize argument
2363 
2364     // don't emit event
2365     if (hci_stack->connectable == enable) return;
2366 
2367     hci_stack->connectable = enable;
2368     hci_update_scan_enable();
2369 }
2370 
2371 void gap_local_bd_addr(bd_addr_t address_buffer){
2372     memcpy(address_buffer, hci_stack->local_bd_addr, 6);
2373 }
2374 
2375 static void hci_run(void){
2376 
2377     // log_info("hci_run: entered");
2378     btstack_linked_item_t * it;
2379 
2380     // send continuation fragments first, as they block the prepared packet buffer
2381     if (hci_stack->acl_fragmentation_total_size > 0) {
2382         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
2383         hci_connection_t *connection = hci_connection_for_handle(con_handle);
2384         if (connection) {
2385             if (hci_can_send_prepared_acl_packet_now(con_handle)){
2386                 hci_send_acl_packet_fragments(connection);
2387                 return;
2388             }
2389         } else {
2390             // connection gone -> discard further fragments
2391             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
2392             hci_stack->acl_fragmentation_total_size = 0;
2393             hci_stack->acl_fragmentation_pos = 0;
2394         }
2395     }
2396 
2397     if (!hci_can_send_command_packet_now()) return;
2398 
2399     // global/non-connection oriented commands
2400 
2401     // decline incoming connections
2402     if (hci_stack->decline_reason){
2403         uint8_t reason = hci_stack->decline_reason;
2404         hci_stack->decline_reason = 0;
2405         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
2406         return;
2407     }
2408 
2409     // send scan enable
2410     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
2411         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
2412         hci_stack->new_scan_enable_value = 0xff;
2413         return;
2414     }
2415 
2416 #ifdef ENABLE_BLE
2417     if (hci_stack->state == HCI_STATE_WORKING){
2418         // handle le scan
2419         switch(hci_stack->le_scanning_state){
2420             case LE_START_SCAN:
2421                 hci_stack->le_scanning_state = LE_SCANNING;
2422                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
2423                 return;
2424 
2425             case LE_STOP_SCAN:
2426                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
2427                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
2428                 return;
2429             default:
2430                 break;
2431         }
2432         if (hci_stack->le_scan_type != 0xff){
2433             // defaults: active scanning, accept all advertisement packets
2434             int scan_type = hci_stack->le_scan_type;
2435             hci_stack->le_scan_type = 0xff;
2436             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);
2437             return;
2438         }
2439         // le advertisement control
2440         if (hci_stack->le_advertisements_todo){
2441             log_info("hci_run: gap_le: adv todo: %x", hci_stack->le_advertisements_todo );
2442         }
2443         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_DISABLE){
2444             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_DISABLE;
2445             hci_send_cmd(&hci_le_set_advertise_enable, 0);
2446             return;
2447         }
2448         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
2449             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
2450             hci_send_cmd(&hci_le_set_advertising_parameters,
2451                  hci_stack->le_advertisements_interval_min,
2452                  hci_stack->le_advertisements_interval_max,
2453                  hci_stack->le_advertisements_type,
2454                  hci_stack->le_advertisements_own_address_type,
2455                  hci_stack->le_advertisements_direct_address_type,
2456                  hci_stack->le_advertisements_direct_address,
2457                  hci_stack->le_advertisements_channel_map,
2458                  hci_stack->le_advertisements_filter_policy);
2459             return;
2460         }
2461         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
2462             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
2463             hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len,
2464                 hci_stack->le_advertisements_data);
2465             return;
2466         }
2467         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
2468             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
2469             hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len,
2470                 hci_stack->le_scan_response_data);
2471             return;
2472         }
2473         if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_ENABLE){
2474             hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_ENABLE;
2475             hci_send_cmd(&hci_le_set_advertise_enable, 1);
2476             return;
2477         }
2478 
2479         //
2480         // LE Whitelist Management
2481         //
2482 
2483         // check if whitelist needs modification
2484         btstack_linked_list_iterator_t lit;
2485         int modification_pending = 0;
2486         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2487         while (btstack_linked_list_iterator_has_next(&lit)){
2488             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2489             if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
2490                 modification_pending = 1;
2491                 break;
2492             }
2493         }
2494 
2495         if (modification_pending){
2496             // stop connnecting if modification pending
2497             if (hci_stack->le_connecting_state != LE_CONNECTING_IDLE){
2498                 hci_send_cmd(&hci_le_create_connection_cancel);
2499                 return;
2500             }
2501 
2502             // add/remove entries
2503             btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2504             while (btstack_linked_list_iterator_has_next(&lit)){
2505                 whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2506                 if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
2507                     entry->state = LE_WHITELIST_ON_CONTROLLER;
2508                     hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
2509                     return;
2510 
2511                 }
2512                 if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
2513                     bd_addr_t address;
2514                     bd_addr_type_t address_type = entry->address_type;
2515                     memcpy(address, entry->address, 6);
2516                     btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
2517                     btstack_memory_whitelist_entry_free(entry);
2518                     hci_send_cmd(&hci_le_remove_device_from_white_list, address_type, address);
2519                     return;
2520                 }
2521             }
2522         }
2523 
2524         // start connecting
2525         if ( hci_stack->le_connecting_state == LE_CONNECTING_IDLE &&
2526             !btstack_linked_list_empty(&hci_stack->le_whitelist)){
2527             bd_addr_t null_addr;
2528             memset(null_addr, 0, 6);
2529             hci_send_cmd(&hci_le_create_connection,
2530                  0x0060,    // scan interval: 60 ms
2531                  0x0030,    // scan interval: 30 ms
2532                  1,         // use whitelist
2533                  0,         // peer address type
2534                  null_addr,      // peer bd addr
2535                  hci_stack->adv_addr_type, // our addr type:
2536                  0x0008,    // conn interval min
2537                  0x0018,    // conn interval max
2538                  0,         // conn latency
2539                  0x0048,    // supervision timeout
2540                  0x0001,    // min ce length
2541                  0x0001     // max ce length
2542                  );
2543             return;
2544         }
2545     }
2546 #endif
2547 
2548     // send pending HCI commands
2549     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
2550         hci_connection_t * connection = (hci_connection_t *) it;
2551 
2552         switch(connection->state){
2553             case SEND_CREATE_CONNECTION:
2554                 switch(connection->address_type){
2555                     case BD_ADDR_TYPE_CLASSIC:
2556                         log_info("sending hci_create_connection");
2557                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
2558                         break;
2559                     default:
2560 #ifdef ENABLE_BLE
2561                         log_info("sending hci_le_create_connection");
2562                         hci_send_cmd(&hci_le_create_connection,
2563                                      0x0060,    // scan interval: 60 ms
2564                                      0x0030,    // scan interval: 30 ms
2565                                      0,         // don't use whitelist
2566                                      connection->address_type, // peer address type
2567                                      connection->address,      // peer bd addr
2568                                      hci_stack->adv_addr_type, // our addr type:
2569                                      0x0008,    // conn interval min
2570                                      0x0018,    // conn interval max
2571                                      0,         // conn latency
2572                                      0x0048,    // supervision timeout
2573                                      0x0001,    // min ce length
2574                                      0x0001     // max ce length
2575                                      );
2576 
2577                         connection->state = SENT_CREATE_CONNECTION;
2578 #endif
2579                         break;
2580                 }
2581                 return;
2582 
2583             case RECEIVED_CONNECTION_REQUEST:
2584                 log_info("sending hci_accept_connection_request, remote eSCO %u", connection->remote_supported_feature_eSCO);
2585                 connection->state = ACCEPTED_CONNECTION_REQUEST;
2586                 connection->role  = HCI_ROLE_SLAVE;
2587                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
2588                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
2589                 }
2590                 return;
2591 
2592 #ifdef ENABLE_BLE
2593             case SEND_CANCEL_CONNECTION:
2594                 connection->state = SENT_CANCEL_CONNECTION;
2595                 hci_send_cmd(&hci_le_create_connection_cancel);
2596                 return;
2597 #endif
2598             case SEND_DISCONNECT:
2599                 connection->state = SENT_DISCONNECT;
2600                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
2601                 return;
2602 
2603             default:
2604                 break;
2605         }
2606 
2607         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
2608             log_info("responding to link key request");
2609             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
2610             link_key_t link_key;
2611             link_key_type_t link_key_type;
2612             if ( hci_stack->link_key_db
2613               && hci_stack->link_key_db->get_link_key(connection->address, link_key, &link_key_type)
2614               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
2615                connection->link_key_type = link_key_type;
2616                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
2617             } else {
2618                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
2619             }
2620             return;
2621         }
2622 
2623         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
2624             log_info("denying to pin request");
2625             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
2626             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
2627             return;
2628         }
2629 
2630         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
2631             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
2632             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
2633             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
2634                 // tweak authentication requirements
2635                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
2636                 if (connection->bonding_flags & BONDING_DEDICATED){
2637                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2638                 }
2639                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
2640                     authreq |= 1;
2641                 }
2642                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
2643             } else {
2644                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
2645             }
2646             return;
2647         }
2648 
2649         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
2650             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
2651             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
2652             return;
2653         }
2654 
2655         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
2656             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
2657             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
2658             return;
2659         }
2660 
2661         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
2662             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
2663             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
2664             return;
2665         }
2666 
2667         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
2668             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
2669             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
2670             return;
2671         }
2672         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
2673             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
2674             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
2675             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
2676             return;
2677         }
2678         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
2679             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
2680             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
2681             return;
2682         }
2683         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2684             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2685             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2686             return;
2687         }
2688 
2689 #ifdef ENABLE_BLE
2690         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2691             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2692 
2693             uint16_t connection_interval_min = connection->le_conn_interval_min;
2694             connection->le_conn_interval_min = 0;
2695             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2696                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2697                 0x0000, 0xffff);
2698         }
2699 #endif
2700     }
2701 
2702     hci_connection_t * connection;
2703     switch (hci_stack->state){
2704         case HCI_STATE_INITIALIZING:
2705             hci_initializing_run();
2706             break;
2707 
2708         case HCI_STATE_HALTING:
2709 
2710             log_info("HCI_STATE_HALTING");
2711 
2712             // free whitelist entries
2713 #ifdef ENABLE_BLE
2714             {
2715                 btstack_linked_list_iterator_t lit;
2716                 btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
2717                 while (btstack_linked_list_iterator_has_next(&lit)){
2718                     whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
2719                     btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
2720                     btstack_memory_whitelist_entry_free(entry);
2721                 }
2722             }
2723 #endif
2724             // close all open connections
2725             connection =  (hci_connection_t *) hci_stack->connections;
2726             if (connection){
2727                 hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
2728                 if (!hci_can_send_command_packet_now()) return;
2729 
2730                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
2731 
2732                 // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
2733                 hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
2734 
2735                 // ... which would be ignored anyway as we shutdown (free) the connection now
2736                 hci_shutdown_connection(connection);
2737 
2738                 // finally, send the disconnect command
2739                 hci_send_cmd(&hci_disconnect, con_handle, 0x13);  // remote closed connection
2740                 return;
2741             }
2742             log_info("HCI_STATE_HALTING, calling off");
2743 
2744             // switch mode
2745             hci_power_control_off();
2746 
2747             log_info("HCI_STATE_HALTING, emitting state");
2748             hci_emit_state();
2749             log_info("HCI_STATE_HALTING, done");
2750             break;
2751 
2752         case HCI_STATE_FALLING_ASLEEP:
2753             switch(hci_stack->substate) {
2754                 case HCI_FALLING_ASLEEP_DISCONNECT:
2755                     log_info("HCI_STATE_FALLING_ASLEEP");
2756                     // close all open connections
2757                     connection =  (hci_connection_t *) hci_stack->connections;
2758 
2759 #ifdef HAVE_PLATFORM_IPHONE_OS
2760                     // don't close connections, if H4 supports power management
2761                     if (btstack_control_iphone_power_management_enabled()){
2762                         connection = NULL;
2763                     }
2764 #endif
2765                     if (connection){
2766 
2767                         // send disconnect
2768                         if (!hci_can_send_command_packet_now()) return;
2769 
2770                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2771                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2772 
2773                         // send disconnected event right away - causes higher layer connections to get closed, too.
2774                         hci_shutdown_connection(connection);
2775                         return;
2776                     }
2777 
2778                     if (hci_classic_supported()){
2779                         // disable page and inquiry scan
2780                         if (!hci_can_send_command_packet_now()) return;
2781 
2782                         log_info("HCI_STATE_HALTING, disabling inq scans");
2783                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2784 
2785                         // continue in next sub state
2786                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
2787                         break;
2788                     }
2789                     // fall through for ble-only chips
2790 
2791                 case HCI_FALLING_ASLEEP_COMPLETE:
2792                     log_info("HCI_STATE_HALTING, calling sleep");
2793 #ifdef HAVE_PLATFORM_IPHONE_OS
2794                     // don't actually go to sleep, if H4 supports power management
2795                     if (btstack_control_iphone_power_management_enabled()){
2796                         // SLEEP MODE reached
2797                         hci_stack->state = HCI_STATE_SLEEPING;
2798                         hci_emit_state();
2799                         break;
2800                     }
2801 #endif
2802                     // switch mode
2803                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2804                     hci_emit_state();
2805                     break;
2806 
2807                 default:
2808                     break;
2809             }
2810             break;
2811 
2812         default:
2813             break;
2814     }
2815 }
2816 
2817 int hci_send_cmd_packet(uint8_t *packet, int size){
2818     bd_addr_t addr;
2819     hci_connection_t * conn;
2820     // house-keeping
2821 
2822     // create_connection?
2823     if (IS_COMMAND(packet, hci_create_connection)){
2824         reverse_bd_addr(&packet[3], addr);
2825         log_info("Create_connection to %s", bd_addr_to_str(addr));
2826 
2827         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2828         if (!conn){
2829             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2830             if (!conn){
2831                 // notify client that alloc failed
2832                 hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
2833                 return 0; // don't sent packet to controller
2834             }
2835             conn->state = SEND_CREATE_CONNECTION;
2836         }
2837         log_info("conn state %u", conn->state);
2838         switch (conn->state){
2839             // if connection active exists
2840             case OPEN:
2841                 // and OPEN, emit connection complete command, don't send to controller
2842                 hci_emit_connection_complete(addr, conn->con_handle, 0);
2843                 return 0;
2844             case SEND_CREATE_CONNECTION:
2845                 // connection created by hci, e.g. dedicated bonding
2846                 break;
2847             default:
2848                 // otherwise, just ignore as it is already in the open process
2849                 return 0;
2850         }
2851         conn->state = SENT_CREATE_CONNECTION;
2852     }
2853     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2854         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2855     }
2856     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2857         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2858     }
2859 
2860     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2861         if (hci_stack->link_key_db){
2862             reverse_bd_addr(&packet[3], addr);
2863             hci_stack->link_key_db->delete_link_key(addr);
2864         }
2865     }
2866 
2867     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2868     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2869         reverse_bd_addr(&packet[3], addr);
2870         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2871         if (conn){
2872             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2873         }
2874     }
2875 
2876     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2877     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2878     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2879     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2880         reverse_bd_addr(&packet[3], addr);
2881         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2882         if (conn){
2883             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2884         }
2885     }
2886 
2887     if (IS_COMMAND(packet, hci_write_loopback_mode)){
2888         hci_stack->loopback_mode = packet[3];
2889     }
2890 
2891 #ifdef ENABLE_BLE
2892     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2893         hci_stack->adv_addr_type = packet[8];
2894     }
2895     if (IS_COMMAND(packet, hci_le_set_random_address)){
2896         reverse_bd_addr(&packet[3], hci_stack->adv_address);
2897     }
2898     if (IS_COMMAND(packet, hci_le_set_advertise_enable)){
2899         hci_stack->le_advertisements_active = packet[3];
2900     }
2901     if (IS_COMMAND(packet, hci_le_create_connection)){
2902         // white list used?
2903         uint8_t initiator_filter_policy = packet[7];
2904         switch (initiator_filter_policy){
2905             case 0:
2906                 // whitelist not used
2907                 hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
2908                 break;
2909             case 1:
2910                 hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
2911                 break;
2912             default:
2913                 log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
2914                 break;
2915         }
2916     }
2917     if (IS_COMMAND(packet, hci_le_create_connection_cancel)){
2918         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2919     }
2920 #endif
2921 
2922     hci_stack->num_cmd_packets--;
2923 
2924     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2925     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2926 
2927     // release packet buffer for synchronous transport implementations
2928     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2929         hci_stack->hci_packet_buffer_reserved = 0;
2930     }
2931 
2932     return err;
2933 }
2934 
2935 // disconnect because of security block
2936 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2937     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2938     if (!connection) return;
2939     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2940 }
2941 
2942 
2943 // Configure Secure Simple Pairing
2944 
2945 // enable will enable SSP during init
2946 void gap_ssp_set_enable(int enable){
2947     hci_stack->ssp_enable = enable;
2948 }
2949 
2950 static int hci_local_ssp_activated(void){
2951     return gap_ssp_supported() && hci_stack->ssp_enable;
2952 }
2953 
2954 // if set, BTstack will respond to io capability request using authentication requirement
2955 void gap_ssp_set_io_capability(int io_capability){
2956     hci_stack->ssp_io_capability = io_capability;
2957 }
2958 void gap_ssp_set_authentication_requirement(int authentication_requirement){
2959     hci_stack->ssp_authentication_requirement = authentication_requirement;
2960 }
2961 
2962 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2963 void gap_ssp_set_auto_accept(int auto_accept){
2964     hci_stack->ssp_auto_accept = auto_accept;
2965 }
2966 
2967 /**
2968  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2969  */
2970 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2971 
2972     if (!hci_can_send_command_packet_now()){
2973         log_error("hci_send_cmd called but cannot send packet now");
2974         return 0;
2975     }
2976 
2977     // for HCI INITIALIZATION
2978     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2979     hci_stack->last_cmd_opcode = cmd->opcode;
2980 
2981     hci_reserve_packet_buffer();
2982     uint8_t * packet = hci_stack->hci_packet_buffer;
2983 
2984     va_list argptr;
2985     va_start(argptr, cmd);
2986     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
2987     va_end(argptr);
2988 
2989     return hci_send_cmd_packet(packet, size);
2990 }
2991 
2992 // Create various non-HCI events.
2993 // TODO: generalize, use table similar to hci_create_command
2994 
2995 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
2996     // dump packet
2997     if (dump) {
2998         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
2999     }
3000 
3001     // dispatch to all event handlers
3002     btstack_linked_list_iterator_t it;
3003     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
3004     while (btstack_linked_list_iterator_has_next(&it)){
3005         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
3006         entry->callback(HCI_EVENT_PACKET, 0, event, size);
3007     }
3008 }
3009 
3010 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
3011     if (!hci_stack->acl_packet_handler) return;
3012     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
3013 }
3014 
3015 static void hci_notify_if_sco_can_send_now(void){
3016     // notify SCO sender if waiting
3017     if (!hci_stack->sco_waiting_for_can_send_now) return;
3018     if (hci_can_send_sco_packet_now()){
3019         hci_stack->sco_waiting_for_can_send_now = 0;
3020         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
3021         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
3022         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
3023     }
3024 }
3025 
3026 void hci_emit_state(void){
3027     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
3028     uint8_t event[3];
3029     event[0] = BTSTACK_EVENT_STATE;
3030     event[1] = sizeof(event) - 2;
3031     event[2] = hci_stack->state;
3032     hci_emit_event(event, sizeof(event), 1);
3033 }
3034 
3035 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
3036     uint8_t event[13];
3037     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
3038     event[1] = sizeof(event) - 2;
3039     event[2] = status;
3040     little_endian_store_16(event, 3, con_handle);
3041     reverse_bd_addr(address, &event[5]);
3042     event[11] = 1; // ACL connection
3043     event[12] = 0; // encryption disabled
3044     hci_emit_event(event, sizeof(event), 1);
3045 }
3046 
3047 static void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
3048     uint8_t event[21];
3049     event[0] = HCI_EVENT_LE_META;
3050     event[1] = sizeof(event) - 2;
3051     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
3052     event[3] = status;
3053     little_endian_store_16(event, 4, con_handle);
3054     event[6] = 0; // TODO: role
3055     event[7] = address_type;
3056     reverse_bd_addr(address, &event[8]);
3057     little_endian_store_16(event, 14, 0); // interval
3058     little_endian_store_16(event, 16, 0); // latency
3059     little_endian_store_16(event, 18, 0); // supervision timeout
3060     event[20] = 0; // master clock accuracy
3061     hci_emit_event(event, sizeof(event), 1);
3062 }
3063 
3064 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
3065     uint8_t event[6];
3066     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
3067     event[1] = sizeof(event) - 2;
3068     event[2] = 0; // status = OK
3069     little_endian_store_16(event, 3, con_handle);
3070     event[5] = reason;
3071     hci_emit_event(event, sizeof(event), 1);
3072 }
3073 
3074 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
3075     if (disable_l2cap_timeouts) return;
3076     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
3077     uint8_t event[4];
3078     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
3079     event[1] = sizeof(event) - 2;
3080     little_endian_store_16(event, 2, conn->con_handle);
3081     hci_emit_event(event, sizeof(event), 1);
3082 }
3083 
3084 static void hci_emit_nr_connections_changed(void){
3085     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
3086     uint8_t event[3];
3087     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
3088     event[1] = sizeof(event) - 2;
3089     event[2] = nr_hci_connections();
3090     hci_emit_event(event, sizeof(event), 1);
3091 }
3092 
3093 static void hci_emit_hci_open_failed(void){
3094     log_info("BTSTACK_EVENT_POWERON_FAILED");
3095     uint8_t event[2];
3096     event[0] = BTSTACK_EVENT_POWERON_FAILED;
3097     event[1] = sizeof(event) - 2;
3098     hci_emit_event(event, sizeof(event), 1);
3099 }
3100 
3101 static void hci_emit_discoverable_enabled(uint8_t enabled){
3102     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
3103     uint8_t event[3];
3104     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
3105     event[1] = sizeof(event) - 2;
3106     event[2] = enabled;
3107     hci_emit_event(event, sizeof(event), 1);
3108 }
3109 
3110 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
3111     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
3112     uint8_t event[5];
3113     int pos = 0;
3114     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
3115     event[pos++] = sizeof(event) - 2;
3116     little_endian_store_16(event, 2, con_handle);
3117     pos += 2;
3118     event[pos++] = level;
3119     hci_emit_event(event, sizeof(event), 1);
3120 }
3121 
3122 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
3123     log_info("hci_emit_dedicated_bonding_result %u ", status);
3124     uint8_t event[9];
3125     int pos = 0;
3126     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
3127     event[pos++] = sizeof(event) - 2;
3128     event[pos++] = status;
3129     reverse_bd_addr(address, &event[pos]);
3130     hci_emit_event(event, sizeof(event), 1);
3131 }
3132 
3133 // query if remote side supports eSCO
3134 int hci_remote_esco_supported(hci_con_handle_t con_handle){
3135     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3136     if (!connection) return 0;
3137     return connection->remote_supported_feature_eSCO;
3138 }
3139 
3140 // query if remote side supports SSP
3141 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
3142     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3143     if (!connection) return 0;
3144     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
3145 }
3146 
3147 int gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
3148     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
3149 }
3150 
3151 // GAP API
3152 /**
3153  * @bbrief enable/disable bonding. default is enabled
3154  * @praram enabled
3155  */
3156 void gap_set_bondable_mode(int enable){
3157     hci_stack->bondable = enable ? 1 : 0;
3158 }
3159 /**
3160  * @brief Get bondable mode.
3161  * @return 1 if bondable
3162  */
3163 int gap_get_bondable_mode(void){
3164     return hci_stack->bondable;
3165 }
3166 
3167 /**
3168  * @brief map link keys to security levels
3169  */
3170 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
3171     switch (link_key_type){
3172         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
3173             return LEVEL_4;
3174         case COMBINATION_KEY:
3175         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
3176             return LEVEL_3;
3177         default:
3178             return LEVEL_2;
3179     }
3180 }
3181 
3182 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
3183     if (!connection) return LEVEL_0;
3184     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
3185     return gap_security_level_for_link_key_type(connection->link_key_type);
3186 }
3187 
3188 
3189 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
3190     log_info("gap_mitm_protection_required_for_security_level %u", level);
3191     return level > LEVEL_2;
3192 }
3193 
3194 /**
3195  * @brief get current security level
3196  */
3197 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
3198     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3199     if (!connection) return LEVEL_0;
3200     return gap_security_level_for_connection(connection);
3201 }
3202 
3203 /**
3204  * @brief request connection to device to
3205  * @result GAP_AUTHENTICATION_RESULT
3206  */
3207 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
3208     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3209     if (!connection){
3210         hci_emit_security_level(con_handle, LEVEL_0);
3211         return;
3212     }
3213     gap_security_level_t current_level = gap_security_level(con_handle);
3214     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
3215     if (current_level >= requested_level){
3216         hci_emit_security_level(con_handle, current_level);
3217         return;
3218     }
3219 
3220     connection->requested_security_level = requested_level;
3221 
3222 #if 0
3223     // sending encryption request without a link key results in an error.
3224     // TODO: figure out how to use it properly
3225 
3226     // would enabling ecnryption suffice (>= LEVEL_2)?
3227     if (hci_stack->link_key_db){
3228         link_key_type_t link_key_type;
3229         link_key_t      link_key;
3230         if (hci_stack->link_key_db->get_link_key( &connection->address, &link_key, &link_key_type)){
3231             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
3232                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3233                 return;
3234             }
3235         }
3236     }
3237 #endif
3238 
3239     // try to authenticate connection
3240     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
3241     hci_run();
3242 }
3243 
3244 /**
3245  * @brief start dedicated bonding with device. disconnect after bonding
3246  * @param device
3247  * @param request MITM protection
3248  * @result GAP_DEDICATED_BONDING_COMPLETE
3249  */
3250 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
3251 
3252     // create connection state machine
3253     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
3254 
3255     if (!connection){
3256         return BTSTACK_MEMORY_ALLOC_FAILED;
3257     }
3258 
3259     // delete linkn key
3260     gap_drop_link_key_for_bd_addr(device);
3261 
3262     // configure LEVEL_2/3, dedicated bonding
3263     connection->state = SEND_CREATE_CONNECTION;
3264     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
3265     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
3266     connection->bonding_flags = BONDING_DEDICATED;
3267 
3268     // wait for GAP Security Result and send GAP Dedicated Bonding complete
3269 
3270     // handle: connnection failure (connection complete != ok)
3271     // handle: authentication failure
3272     // handle: disconnect on done
3273 
3274     hci_run();
3275 
3276     return 0;
3277 }
3278 
3279 void gap_set_local_name(const char * local_name){
3280     hci_stack->local_name = local_name;
3281 }
3282 
3283 void gap_start_scan(void){
3284     if (hci_stack->le_scanning_state == LE_SCANNING) return;
3285     hci_stack->le_scanning_state = LE_START_SCAN;
3286     hci_run();
3287 }
3288 
3289 void gap_stop_scan(void){
3290     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return;
3291     hci_stack->le_scanning_state = LE_STOP_SCAN;
3292     hci_run();
3293 }
3294 
3295 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
3296     hci_stack->le_scan_type     = scan_type;
3297     hci_stack->le_scan_interval = scan_interval;
3298     hci_stack->le_scan_window   = scan_window;
3299     hci_run();
3300 }
3301 
3302 uint8_t gap_connect(bd_addr_t addr, bd_addr_type_t addr_type){
3303     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3304     if (!conn){
3305         log_info("gap_connect: no connection exists yet, creating context");
3306         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
3307         if (!conn){
3308             // notify client that alloc failed
3309             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
3310             log_info("gap_connect: failed to alloc hci_connection_t");
3311             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
3312         }
3313         conn->state = SEND_CREATE_CONNECTION;
3314         log_info("gap_connect: send create connection next");
3315         hci_run();
3316         return 0;
3317     }
3318 
3319     if (!hci_is_le_connection(conn) ||
3320         conn->state == SEND_CREATE_CONNECTION ||
3321         conn->state == SENT_CREATE_CONNECTION) {
3322         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
3323         log_error("gap_connect: classic connection or connect is already being created");
3324         return GATT_CLIENT_IN_WRONG_STATE;
3325     }
3326 
3327     log_info("gap_connect: context exists with state %u", conn->state);
3328     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
3329     hci_run();
3330     return 0;
3331 }
3332 
3333 // @assumption: only a single outgoing LE Connection exists
3334 static hci_connection_t * gap_get_outgoing_connection(void){
3335     btstack_linked_item_t *it;
3336     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
3337         hci_connection_t * conn = (hci_connection_t *) it;
3338         if (!hci_is_le_connection(conn)) continue;
3339         switch (conn->state){
3340             case SEND_CREATE_CONNECTION:
3341             case SENT_CREATE_CONNECTION:
3342                 return conn;
3343             default:
3344                 break;
3345         };
3346     }
3347     return NULL;
3348 }
3349 
3350 uint8_t gap_connect_cancel(void){
3351     hci_connection_t * conn = gap_get_outgoing_connection();
3352     if (!conn) return 0;
3353     switch (conn->state){
3354         case SEND_CREATE_CONNECTION:
3355             // skip sending create connection and emit event instead
3356             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
3357             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
3358             btstack_memory_hci_connection_free( conn );
3359             break;
3360         case SENT_CREATE_CONNECTION:
3361             // request to send cancel connection
3362             conn->state = SEND_CANCEL_CONNECTION;
3363             hci_run();
3364             break;
3365         default:
3366             break;
3367     }
3368     return 0;
3369 }
3370 
3371 /**
3372  * @brief Updates the connection parameters for a given LE connection
3373  * @param handle
3374  * @param conn_interval_min (unit: 1.25ms)
3375  * @param conn_interval_max (unit: 1.25ms)
3376  * @param conn_latency
3377  * @param supervision_timeout (unit: 10ms)
3378  * @returns 0 if ok
3379  */
3380 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
3381     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
3382     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3383     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3384     connection->le_conn_interval_min = conn_interval_min;
3385     connection->le_conn_interval_max = conn_interval_max;
3386     connection->le_conn_latency = conn_latency;
3387     connection->le_supervision_timeout = supervision_timeout;
3388     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
3389     hci_run();
3390     return 0;
3391 }
3392 
3393 /**
3394  * @brief Request an update of the connection parameter for a given LE connection
3395  * @param handle
3396  * @param conn_interval_min (unit: 1.25ms)
3397  * @param conn_interval_max (unit: 1.25ms)
3398  * @param conn_latency
3399  * @param supervision_timeout (unit: 10ms)
3400  * @returns 0 if ok
3401  */
3402 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
3403     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
3404     hci_connection_t * connection = hci_connection_for_handle(con_handle);
3405     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3406     connection->le_conn_interval_min = conn_interval_min;
3407     connection->le_conn_interval_max = conn_interval_max;
3408     connection->le_conn_latency = conn_latency;
3409     connection->le_supervision_timeout = supervision_timeout;
3410     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
3411     hci_run();
3412     return 0;
3413 }
3414 
3415 static void gap_advertisments_changed(void){
3416     // disable advertisements before updating adv, scan data, or adv params
3417     if (hci_stack->le_advertisements_active){
3418         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE | LE_ADVERTISEMENT_TASKS_ENABLE;
3419     }
3420     hci_run();
3421 }
3422 
3423 /**
3424  * @brief Set Advertisement Data
3425  * @param advertising_data_length
3426  * @param advertising_data (max 31 octets)
3427  * @note data is not copied, pointer has to stay valid
3428  */
3429 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
3430     hci_stack->le_advertisements_data_len = advertising_data_length;
3431     hci_stack->le_advertisements_data = advertising_data;
3432     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3433     gap_advertisments_changed();
3434 }
3435 
3436 /**
3437  * @brief Set Scan Response Data
3438  * @param advertising_data_length
3439  * @param advertising_data (max 31 octets)
3440  * @note data is not copied, pointer has to stay valid
3441  */
3442 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
3443     hci_stack->le_scan_response_data_len = scan_response_data_length;
3444     hci_stack->le_scan_response_data = scan_response_data;
3445     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
3446     gap_advertisments_changed();
3447 }
3448 
3449 /**
3450  * @brief Set Advertisement Parameters
3451  * @param adv_int_min
3452  * @param adv_int_max
3453  * @param adv_type
3454  * @param own_address_type
3455  * @param direct_address_type
3456  * @param direct_address
3457  * @param channel_map
3458  * @param filter_policy
3459  *
3460  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
3461  */
3462  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
3463     uint8_t own_address_type, uint8_t direct_address_typ, bd_addr_t direct_address,
3464     uint8_t channel_map, uint8_t filter_policy) {
3465 
3466     hci_stack->le_advertisements_interval_min = adv_int_min;
3467     hci_stack->le_advertisements_interval_max = adv_int_max;
3468     hci_stack->le_advertisements_type = adv_type;
3469     hci_stack->le_advertisements_own_address_type = own_address_type;
3470     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
3471     hci_stack->le_advertisements_channel_map = channel_map;
3472     hci_stack->le_advertisements_filter_policy = filter_policy;
3473     memcpy(hci_stack->le_advertisements_direct_address, direct_address, 6);
3474 
3475     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3476     gap_advertisments_changed();
3477  }
3478 
3479 /**
3480  * @brief Enable/Disable Advertisements
3481  * @param enabled
3482  */
3483 void gap_advertisements_enable(int enabled){
3484     hci_stack->le_advertisements_enabled = enabled;
3485     if (enabled && !hci_stack->le_advertisements_active){
3486         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_ENABLE;
3487     }
3488     if (!enabled && hci_stack->le_advertisements_active){
3489         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_DISABLE;
3490     }
3491     hci_run();
3492 }
3493 
3494 
3495 uint8_t gap_disconnect(hci_con_handle_t handle){
3496     hci_connection_t * conn = hci_connection_for_handle(handle);
3497     if (!conn){
3498         hci_emit_disconnection_complete(handle, 0);
3499         return 0;
3500     }
3501     conn->state = SEND_DISCONNECT;
3502     hci_run();
3503     return 0;
3504 }
3505 
3506 /**
3507  * @brief Get connection type
3508  * @param con_handle
3509  * @result connection_type
3510  */
3511 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
3512     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
3513     if (!conn) return GAP_CONNECTION_INVALID;
3514     switch (conn->address_type){
3515         case BD_ADDR_TYPE_LE_PUBLIC:
3516         case BD_ADDR_TYPE_LE_RANDOM:
3517             return GAP_CONNECTION_LE;
3518         case BD_ADDR_TYPE_SCO:
3519             return GAP_CONNECTION_SCO;
3520         case BD_ADDR_TYPE_CLASSIC:
3521             return GAP_CONNECTION_ACL;
3522         default:
3523             return GAP_CONNECTION_INVALID;
3524     }
3525 }
3526 
3527 #ifdef ENABLE_BLE
3528 
3529 /**
3530  * @brief Auto Connection Establishment - Start Connecting to device
3531  * @param address_typ
3532  * @param address
3533  * @returns 0 if ok
3534  */
3535 int gap_auto_connection_start(bd_addr_type_t address_type, bd_addr_t address){
3536     // check capacity
3537     int num_entries = btstack_linked_list_count(&hci_stack->le_whitelist);
3538     if (num_entries >= hci_stack->le_whitelist_capacity) return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
3539     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
3540     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
3541     entry->address_type = address_type;
3542     memcpy(entry->address, address, 6);
3543     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
3544     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
3545     hci_run();
3546     return 0;
3547 }
3548 
3549 static void hci_remove_from_whitelist(bd_addr_type_t address_type, bd_addr_t address){
3550     btstack_linked_list_iterator_t it;
3551     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
3552     while (btstack_linked_list_iterator_has_next(&it)){
3553         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
3554         if (entry->address_type != address_type) continue;
3555         if (memcmp(entry->address, address, 6) != 0) continue;
3556         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
3557             // remove from controller if already present
3558             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3559             continue;
3560         }
3561         // direclty remove entry from whitelist
3562         btstack_linked_list_iterator_remove(&it);
3563         btstack_memory_whitelist_entry_free(entry);
3564     }
3565 }
3566 
3567 /**
3568  * @brief Auto Connection Establishment - Stop Connecting to device
3569  * @param address_typ
3570  * @param address
3571  * @returns 0 if ok
3572  */
3573 int gap_auto_connection_stop(bd_addr_type_t address_type, bd_addr_t address){
3574     hci_remove_from_whitelist(address_type, address);
3575     hci_run();
3576     return 0;
3577 }
3578 
3579 /**
3580  * @brief Auto Connection Establishment - Stop everything
3581  * @note  Convenience function to stop all active auto connection attempts
3582  */
3583 void gap_auto_connection_stop_all(void){
3584     btstack_linked_list_iterator_t it;
3585     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
3586     while (btstack_linked_list_iterator_has_next(&it)){
3587         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
3588         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
3589             // remove from controller if already present
3590             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
3591             continue;
3592         }
3593         // directly remove entry from whitelist
3594         btstack_linked_list_iterator_remove(&it);
3595         btstack_memory_whitelist_entry_free(entry);
3596     }
3597     hci_run();
3598 }
3599 
3600 #endif
3601 
3602 /**
3603  * @brief Set Extended Inquiry Response data
3604  * @param eir_data size 240 bytes, is not copied make sure memory is accessible during stack startup
3605  * @note has to be done before stack starts up
3606  */
3607 void gap_set_extended_inquiry_response(const uint8_t * data){
3608     hci_stack->eir_data = data;
3609 }
3610 
3611 /**
3612  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
3613  * @param inquriy_mode see bluetooth_defines.h
3614  */
3615 void hci_set_inquiry_mode(inquiry_mode_t mode){
3616     hci_stack->inquiry_mode = mode;
3617 }
3618 
3619 /**
3620  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
3621  */
3622 void hci_set_sco_voice_setting(uint16_t voice_setting){
3623     hci_stack->sco_voice_setting = voice_setting;
3624 }
3625 
3626 /**
3627  * @brief Get SCO Voice Setting
3628  * @return current voice setting
3629  */
3630 uint16_t hci_get_sco_voice_setting(void){
3631     return hci_stack->sco_voice_setting;
3632 }
3633 
3634 /** @brief Get SCO packet length for current SCO Voice setting
3635  *  @note  Using SCO packets of the exact length is required for USB transfer
3636  *  @return Length of SCO packets in bytes (not audio frames)
3637  */
3638 int hci_get_sco_packet_length(void){
3639     // see Core Spec for H2 USB Transfer.
3640     if (hci_stack->sco_voice_setting & 0x0020) return 51;
3641     return 27;
3642 }
3643 
3644 /**
3645  * @brief Set callback for Bluetooth Hardware Error
3646  */
3647 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
3648     hci_stack->hardware_error_callback = fn;
3649 }
3650 
3651 /**
3652  * @brief Set callback for local information from Bluetooth controller right after HCI Reset
3653  * @note Can be used to select chipset driver dynamically during startup
3654  */
3655 void hci_set_local_version_information_callback(void (*fn)(uint8_t * local_version_information)){
3656     hci_stack->local_version_information_callback = fn;
3657 }
3658 
3659 void hci_disconnect_all(void){
3660     btstack_linked_list_iterator_t it;
3661     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
3662     while (btstack_linked_list_iterator_has_next(&it)){
3663         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
3664         if (con->state == SENT_DISCONNECT) continue;
3665         con->state = SEND_DISCONNECT;
3666     }
3667     hci_run();
3668 }
3669