xref: /btstack/src/hci.c (revision 23a77e1a6f85bdec52c8169960e87d6f16dbd58c)
1 /*
2  * Copyright (C) 2009-2012 by Matthias Ringwald
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 MATTHIAS RINGWALD 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 [email protected]
34  *
35  */
36 
37 /*
38  *  hci.c
39  *
40  *  Created by Matthias Ringwald on 4/29/09.
41  *
42  */
43 
44 #include "btstack-config.h"
45 
46 #include "hci.h"
47 #include "gap.h"
48 
49 #include <stdarg.h>
50 #include <string.h>
51 #include <stdio.h>
52 
53 #ifndef EMBEDDED
54 #ifdef _WIN32
55 #include "Winsock2.h"
56 #else
57 #include <unistd.h> // gethostbyname
58 #endif
59 #include <btstack/version.h>
60 #endif
61 
62 #include "btstack_memory.h"
63 #include "debug.h"
64 #include "hci_dump.h"
65 
66 #include <btstack/linked_list.h>
67 #include <btstack/hci_cmds.h>
68 
69 #define HCI_CONNECTION_TIMEOUT_MS 10000
70 
71 #define HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP 11
72 
73 #ifdef USE_BLUETOOL
74 #include "../platforms/ios/src/bt_control_iphone.h"
75 #endif
76 
77 static void hci_update_scan_enable(void);
78 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
79 static void hci_connection_timeout_handler(timer_source_t *timer);
80 static void hci_connection_timestamp(hci_connection_t *connection);
81 static int  hci_power_control_on(void);
82 static void hci_power_control_off(void);
83 static void hci_state_reset();
84 
85 // the STACK is here
86 #ifndef HAVE_MALLOC
87 static hci_stack_t   hci_stack_static;
88 #endif
89 static hci_stack_t * hci_stack = NULL;
90 
91 // test helper
92 static uint8_t disable_l2cap_timeouts = 0;
93 
94 /**
95  * create connection for given address
96  *
97  * @return connection OR NULL, if no memory left
98  */
99 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
100 
101     log_info("create_connection_for_addr %s", bd_addr_to_str(addr));
102     hci_connection_t * conn = btstack_memory_hci_connection_get();
103     if (!conn) return NULL;
104     BD_ADDR_COPY(conn->address, addr);
105     conn->address_type = addr_type;
106     conn->con_handle = 0xffff;
107     conn->authentication_flags = AUTH_FLAGS_NONE;
108     conn->bonding_flags = 0;
109     conn->requested_security_level = LEVEL_0;
110     linked_item_set_user(&conn->timeout.item, conn);
111     conn->timeout.process = hci_connection_timeout_handler;
112     hci_connection_timestamp(conn);
113     conn->acl_recombination_length = 0;
114     conn->acl_recombination_pos = 0;
115     conn->num_acl_packets_sent = 0;
116     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
117     linked_list_add(&hci_stack->connections, (linked_item_t *) conn);
118     return conn;
119 }
120 
121 
122 /**
123  * get le connection parameter range
124 *
125  * @return le connection parameter range struct
126  */
127 le_connection_parameter_range_t gap_le_get_connection_parameter_range(){
128     return hci_stack->le_connection_parameter_range;
129 }
130 
131 /**
132  * set le connection parameter range
133  *
134  */
135 
136 void gap_le_set_connection_parameter_range(le_connection_parameter_range_t range){
137     hci_stack->le_connection_parameter_range.le_conn_interval_min = range.le_conn_interval_min;
138     hci_stack->le_connection_parameter_range.le_conn_interval_max = range.le_conn_interval_max;
139     hci_stack->le_connection_parameter_range.le_conn_interval_min = range.le_conn_latency_min;
140     hci_stack->le_connection_parameter_range.le_conn_interval_max = range.le_conn_latency_max;
141     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = range.le_supervision_timeout_min;
142     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = range.le_supervision_timeout_max;
143 }
144 
145 /**
146  * get hci connections iterator
147  *
148  * @return hci connections iterator
149  */
150 
151 void hci_connections_get_iterator(linked_list_iterator_t *it){
152     linked_list_iterator_init(it, &hci_stack->connections);
153 }
154 
155 /**
156  * get connection for a given handle
157  *
158  * @return connection OR NULL, if not found
159  */
160 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
161     linked_list_iterator_t it;
162     linked_list_iterator_init(&it, &hci_stack->connections);
163     while (linked_list_iterator_has_next(&it)){
164         hci_connection_t * item = (hci_connection_t *) linked_list_iterator_next(&it);
165         if ( item->con_handle == con_handle ) {
166             return item;
167         }
168     }
169     return NULL;
170 }
171 
172 /**
173  * get connection for given address
174  *
175  * @return connection OR NULL, if not found
176  */
177 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t * addr, bd_addr_type_t addr_type){
178     linked_list_iterator_t it;
179     linked_list_iterator_init(&it, &hci_stack->connections);
180     while (linked_list_iterator_has_next(&it)){
181         hci_connection_t * connection = (hci_connection_t *) linked_list_iterator_next(&it);
182         if (connection->address_type != addr_type)  continue;
183         if (memcmp(addr, connection->address, 6) != 0) continue;
184         return connection;
185     }
186     return NULL;
187 }
188 
189 static void hci_connection_timeout_handler(timer_source_t *timer){
190     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
191 #ifdef HAVE_TIME
192     struct timeval tv;
193     gettimeofday(&tv, NULL);
194     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
195         // connections might be timed out
196         hci_emit_l2cap_check_timeout(connection);
197     }
198 #endif
199 #ifdef HAVE_TICK
200     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
201         // connections might be timed out
202         hci_emit_l2cap_check_timeout(connection);
203     }
204 #endif
205     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
206     run_loop_add_timer(timer);
207 }
208 
209 static void hci_connection_timestamp(hci_connection_t *connection){
210 #ifdef HAVE_TIME
211     gettimeofday(&connection->timestamp, NULL);
212 #endif
213 #ifdef HAVE_TICK
214     connection->timestamp = embedded_get_ticks();
215 #endif
216 }
217 
218 
219 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
220     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
221 }
222 
223 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
224     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
225 }
226 
227 
228 /**
229  * add authentication flags and reset timer
230  * @note: assumes classic connection
231  */
232 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
233     bd_addr_t addr;
234     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
235     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
236     if (conn) {
237         connectionSetAuthenticationFlags(conn, flags);
238         hci_connection_timestamp(conn);
239     }
240 }
241 
242 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
243     hci_connection_t * conn = hci_connection_for_handle(handle);
244     if (!conn) return 0;
245     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
246     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
247     return 0;
248 }
249 
250 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
251     if (hci_stack->remote_device_db) {
252         hci_stack->remote_device_db->delete_link_key(addr);
253     }
254 }
255 
256 int hci_is_le_connection(hci_connection_t * connection){
257     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
258     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
259 }
260 
261 
262 /**
263  * count connections
264  */
265 static int nr_hci_connections(void){
266     int count = 0;
267     linked_item_t *it;
268     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
269     return count;
270 }
271 
272 /**
273  * Dummy handler called by HCI
274  */
275 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
276 }
277 
278 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
279     hci_connection_t * connection = hci_connection_for_handle(handle);
280     if (!connection) {
281         log_error("hci_number_outgoing_packets: connection for handle %u does not exist!", handle);
282         return 0;
283     }
284     return connection->num_acl_packets_sent;
285 }
286 
287 uint8_t hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
288 
289     int num_packets_sent_classic = 0;
290     int num_packets_sent_le = 0;
291 
292     bd_addr_type_t address_type = BD_ADDR_TYPE_UNKNOWN;
293 
294     linked_item_t *it;
295     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
296         hci_connection_t * connection = (hci_connection_t *) it;
297         if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
298             num_packets_sent_classic += connection->num_acl_packets_sent;
299         } else {
300             num_packets_sent_le += connection->num_acl_packets_sent;
301         }
302         if (connection->con_handle == con_handle){
303             address_type = connection->address_type;
304         }
305     }
306 
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: handle 0x%04x not in connection list", con_handle);
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 
348 // @deprecated
349 int hci_can_send_packet_now(uint8_t packet_type){
350     switch (packet_type) {
351         case HCI_ACL_DATA_PACKET:
352             return hci_can_send_prepared_acl_packet_now(0);
353         case HCI_COMMAND_DATA_PACKET:
354             return hci_can_send_command_packet_now();
355         default:
356             return 0;
357     }
358 }
359 
360 // @deprecated
361 // same as hci_can_send_packet_now, but also checks if packet buffer is free for use
362 int hci_can_send_packet_now_using_packet_buffer(uint8_t packet_type){
363 
364     if (hci_stack->hci_packet_buffer_reserved) return 0;
365 
366     switch (packet_type) {
367         case HCI_ACL_DATA_PACKET:
368             return hci_can_send_acl_packet_now(0);
369         case HCI_COMMAND_DATA_PACKET:
370             return hci_can_send_command_packet_now();
371         default:
372             return 0;
373     }
374 }
375 
376 
377 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
378 int hci_can_send_command_packet_now(void){
379     if (hci_stack->hci_packet_buffer_reserved) return 0;
380 
381     // check for async hci transport implementations
382     if (hci_stack->hci_transport->can_send_packet_now){
383         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
384             return 0;
385         }
386     }
387 
388     return hci_stack->num_cmd_packets > 0;
389 }
390 
391 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
392     // check for async hci transport implementations
393     if (hci_stack->hci_transport->can_send_packet_now){
394         if (!hci_stack->hci_transport->can_send_packet_now(HCI_ACL_DATA_PACKET)){
395             return 0;
396         }
397     }
398     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
399 }
400 
401 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
402     if (hci_stack->hci_packet_buffer_reserved) return 0;
403     return hci_can_send_prepared_acl_packet_now(con_handle);
404 }
405 
406 // used for internal checks in l2cap[-le].c
407 int hci_is_packet_buffer_reserved(void){
408     return hci_stack->hci_packet_buffer_reserved;
409 }
410 
411 // reserves outgoing packet buffer. @returns 1 if successful
412 int hci_reserve_packet_buffer(void){
413     if (hci_stack->hci_packet_buffer_reserved) {
414         log_error("hci_reserve_packet_buffer called but buffer already reserved");
415         return 0;
416     }
417     hci_stack->hci_packet_buffer_reserved = 1;
418     return 1;
419 }
420 
421 void hci_release_packet_buffer(void){
422     hci_stack->hci_packet_buffer_reserved = 0;
423 }
424 
425 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
426 int hci_transport_synchronous(void){
427     return hci_stack->hci_transport->can_send_packet_now == NULL;
428 }
429 
430 uint16_t hci_max_acl_le_data_packet_length(void){
431     return hci_stack->le_data_packets_length > 0 ? hci_stack->le_data_packets_length : hci_stack->acl_data_packet_length;
432 }
433 
434 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
435 
436     // 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);
437 
438     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
439     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
440     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
441         max_acl_data_packet_length = hci_stack->le_data_packets_length;
442     }
443 
444     // testing: reduce buffer to minimum
445     // max_acl_data_packet_length = 52;
446 
447     int err;
448     // multiple packets could be send on a synchronous HCI transport
449     while (1){
450 
451         // get current data
452         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
453         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
454         int more_fragments = 0;
455 
456         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
457         if (current_acl_data_packet_length > max_acl_data_packet_length){
458             more_fragments = 1;
459             current_acl_data_packet_length = max_acl_data_packet_length;
460         }
461 
462         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
463         if (acl_header_pos > 0){
464             uint16_t handle_and_flags = READ_BT_16(hci_stack->hci_packet_buffer, 0);
465             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
466             bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
467         }
468 
469         // update header len
470         bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
471 
472         // count packet
473         connection->num_acl_packets_sent++;
474 
475         // send packet
476         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
477         const int size = current_acl_data_packet_length + 4;
478         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
479         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
480 
481         // done yet?
482         if (!more_fragments) break;
483 
484         // update start of next fragment to send
485         hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
486 
487         // can send more?
488         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
489     }
490 
491     // done
492     hci_stack->acl_fragmentation_pos = 0;
493     hci_stack->acl_fragmentation_total_size = 0;
494 
495     // release buffer now for synchronous transport
496     if (hci_transport_synchronous()){
497         hci_release_packet_buffer();
498     }
499 
500     return err;
501 }
502 
503 // pre: caller has reserved the packet buffer
504 int hci_send_acl_packet_buffer(int size){
505 
506     // log_info("hci_send_acl_packet_buffer size %u", size);
507 
508     if (!hci_stack->hci_packet_buffer_reserved) {
509         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
510         return 0;
511     }
512 
513     uint8_t * packet = hci_stack->hci_packet_buffer;
514     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
515 
516     // check for free places on Bluetooth module
517     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
518         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
519         hci_release_packet_buffer();
520         return BTSTACK_ACL_BUFFERS_FULL;
521     }
522 
523     hci_connection_t *connection = hci_connection_for_handle( con_handle);
524     if (!connection) {
525         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
526         hci_release_packet_buffer();
527         return 0;
528     }
529     hci_connection_timestamp(connection);
530 
531     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
532 
533     // setup data
534     hci_stack->acl_fragmentation_total_size = size;
535     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
536 
537     return hci_send_acl_packet_fragments(connection);
538 }
539 
540 static void acl_handler(uint8_t *packet, int size){
541 
542     // log_info("acl_handler: size %u", size);
543 
544     // get info
545     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
546     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
547     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
548     uint16_t acl_length         = READ_ACL_LENGTH(packet);
549 
550     // ignore non-registered handle
551     if (!conn){
552         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
553         return;
554     }
555 
556     // assert packet is complete
557     if (acl_length + 4 != size){
558         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
559         return;
560     }
561 
562     // update idle timestamp
563     hci_connection_timestamp(conn);
564 
565     // handle different packet types
566     switch (acl_flags & 0x03) {
567 
568         case 0x01: // continuation fragment
569 
570             // sanity checks
571             if (conn->acl_recombination_pos == 0) {
572                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
573                 return;
574             }
575             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
576                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
577                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
578                 conn->acl_recombination_pos = 0;
579                 return;
580             }
581 
582             // append fragment payload (header already stored)
583             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
584             conn->acl_recombination_pos += acl_length;
585 
586             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
587             //        conn->acl_recombination_pos, conn->acl_recombination_length);
588 
589             // forward complete L2CAP packet if complete.
590             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
591 
592                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, &conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
593                 // reset recombination buffer
594                 conn->acl_recombination_length = 0;
595                 conn->acl_recombination_pos = 0;
596             }
597             break;
598 
599         case 0x02: { // first fragment
600 
601             // sanity check
602             if (conn->acl_recombination_pos) {
603                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
604                 conn->acl_recombination_pos = 0;
605             }
606 
607             // peek into L2CAP packet!
608             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
609 
610             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
611 
612             // compare fragment size to L2CAP packet size
613             if (acl_length >= l2cap_length + 4){
614 
615                 // forward fragment as L2CAP packet
616                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
617 
618             } else {
619 
620                 if (acl_length > HCI_ACL_BUFFER_SIZE){
621                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
622                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
623                     return;
624                 }
625 
626                 // store first fragment and tweak acl length for complete package
627                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
628                 conn->acl_recombination_pos    = acl_length + 4;
629                 conn->acl_recombination_length = l2cap_length;
630                 bt_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
631             }
632             break;
633 
634         }
635         default:
636             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
637             return;
638     }
639 
640     // execute main loop
641     hci_run();
642 }
643 
644 static void hci_shutdown_connection(hci_connection_t *conn){
645     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
646 
647     run_loop_remove_timer(&conn->timeout);
648 
649     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
650     btstack_memory_hci_connection_free( conn );
651 
652     // now it's gone
653     hci_emit_nr_connections_changed();
654 }
655 
656 static const uint16_t packet_type_sizes[] = {
657     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
658     HCI_ACL_DH1_SIZE, 0, 0, 0,
659     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
660     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
661 };
662 static const uint8_t  packet_type_feature_requirement_bit[] = {
663      0, // 3 slot packets
664      1, // 5 slot packets
665     25, // EDR 2 mpbs
666     26, // EDR 3 mbps
667     39, // 3 slot EDR packts
668     40, // 5 slot EDR packet
669 };
670 static const uint16_t packet_type_feature_packet_mask[] = {
671     0x0f00, // 3 slot packets
672     0xf000, // 5 slot packets
673     0x1102, // EDR 2 mpbs
674     0x2204, // EDR 3 mbps
675     0x0300, // 3 slot EDR packts
676     0x3000, // 5 slot EDR packet
677 };
678 
679 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
680     // enable packet types based on size
681     uint16_t packet_types = 0;
682     unsigned int i;
683     for (i=0;i<16;i++){
684         if (packet_type_sizes[i] == 0) continue;
685         if (packet_type_sizes[i] <= buffer_size){
686             packet_types |= 1 << i;
687         }
688     }
689     // disable packet types due to missing local supported features
690     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
691         int bit_idx = packet_type_feature_requirement_bit[i];
692         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
693         if (feature_set) continue;
694         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
695         packet_types &= ~packet_type_feature_packet_mask[i];
696     }
697     // flip bits for "may not be used"
698     packet_types ^= 0x3306;
699     return packet_types;
700 }
701 
702 uint16_t hci_usable_acl_packet_types(void){
703     return hci_stack->packet_types;
704 }
705 
706 uint8_t* hci_get_outgoing_packet_buffer(void){
707     // hci packet buffer is >= acl data packet length
708     return hci_stack->hci_packet_buffer;
709 }
710 
711 uint16_t hci_max_acl_data_packet_length(void){
712     return hci_stack->acl_data_packet_length;
713 }
714 
715 int hci_non_flushable_packet_boundary_flag_supported(void){
716     // No. 54, byte 6, bit 6
717     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
718 }
719 
720 int hci_ssp_supported(void){
721     // No. 51, byte 6, bit 3
722     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
723 }
724 
725 int hci_classic_supported(void){
726     // No. 37, byte 4, bit 5, = No BR/EDR Support
727     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
728 }
729 
730 int hci_le_supported(void){
731 #ifdef HAVE_BLE
732     // No. 37, byte 4, bit 6 = LE Supported (Controller)
733     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
734 #else
735     return 0;
736 #endif
737 }
738 
739 // get addr type and address used in advertisement packets
740 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
741     *addr_type = hci_stack->adv_addr_type;
742     if (hci_stack->adv_addr_type){
743         memcpy(addr, hci_stack->adv_address, 6);
744     } else {
745         memcpy(addr, hci_stack->local_bd_addr, 6);
746     }
747 }
748 
749 #ifdef HAVE_BLE
750 void le_handle_advertisement_report(uint8_t *packet, int size){
751     int offset = 3;
752     int num_reports = packet[offset];
753     offset += 1;
754 
755     int i;
756     log_info("HCI: handle adv report with num reports: %d", num_reports);
757     for (i=0; i<num_reports;i++){
758         uint8_t data_length = packet[offset + 8];
759         uint8_t event_size = 10 + data_length;
760         uint8_t event[2 + event_size ];
761         int pos = 0;
762         event[pos++] = GAP_LE_ADVERTISING_REPORT;
763         event[pos++] = event_size;
764         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
765         offset += 8;
766         pos += 8;
767         event[pos++] = packet[offset + 1 + data_length]; // rssi
768         event[pos++] = packet[offset++]; //data_length;
769         memcpy(&event[pos], &packet[offset], data_length);
770         pos += data_length;
771         offset += data_length + 1; // rssi
772         hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
773         hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
774     }
775 }
776 #endif
777 
778 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
779     uint8_t command_completed = 0;
780     if ((hci_stack->substate % 2) == 0) return;
781     // odd: waiting for event
782     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
783         uint16_t opcode = READ_BT_16(packet,3);
784         if (opcode == hci_stack->last_cmd_opcode){
785             command_completed = 1;
786             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate);
787         } else {
788             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
789         }
790     }
791     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
792         uint8_t  status = packet[2];
793         uint16_t opcode = READ_BT_16(packet,4);
794         if (opcode == hci_stack->last_cmd_opcode){
795             if (status){
796                 command_completed = 1;
797                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate);
798             } else {
799                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
800             }
801         } else {
802             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
803         }
804     }
805 
806     if (!command_completed) return;
807 
808     switch(hci_stack->substate >> 1){
809         default:
810             hci_stack->substate++;
811             break;
812     }
813 }
814 
815 static void hci_initializing_state_machine(){
816         // log_info("hci_init: substate %u", hci_stack->substate);
817     if (hci_stack->substate % 2) {
818         // odd: waiting for command completion
819         return;
820     }
821     switch (hci_stack->substate >> 1){
822         case 0: // RESET
823             hci_state_reset();
824 
825             hci_send_cmd(&hci_reset);
826             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
827                 // skip baud change
828                 hci_stack->substate = 4; // >> 1 = 2
829             }
830             break;
831         case 1: // SEND BAUD CHANGE
832             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
833             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
834             hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
835             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
836             break;
837         case 2: // LOCAL BAUD CHANGE
838             log_info("Local baud rate change");
839             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
840             hci_stack->substate += 2;
841             // break missing here for fall through
842 
843         case 3:
844             log_info("Custom init");
845             // Custom initialization
846             if (hci_stack->control && hci_stack->control->next_cmd){
847                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
848                 if (valid_cmd){
849                     int size = 3 + hci_stack->hci_packet_buffer[2];
850                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
851                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
852                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
853                     hci_stack->substate = 4; // more init commands
854                     break;
855                 }
856                 log_info("hci_run: init script done");
857             }
858             // otherwise continue
859             hci_send_cmd(&hci_read_bd_addr);
860             break;
861         case 4:
862             hci_send_cmd(&hci_read_buffer_size);
863             break;
864         case 5:
865             hci_send_cmd(&hci_read_local_supported_features);
866             break;
867         case 6:
868             if (hci_le_supported()){
869                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
870             } else {
871                 // Kensington Bluetoot 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
872                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
873             }
874 
875             // skip Classic init commands for LE only chipsets
876             if (!hci_classic_supported()){
877                 if (hci_le_supported()){
878                     hci_stack->substate = 11 << 1;    // skip all classic command
879                 } else {
880                     log_error("Neither BR/EDR nor LE supported");
881                     hci_stack->substate = 14 << 1;    // skip all
882                 }
883             }
884             break;
885         case 7:
886             if (hci_ssp_supported()){
887                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
888                 break;
889             }
890             hci_stack->substate += 2;
891             // break missing here for fall through
892 
893         case 8:
894             // ca. 15 sec
895             hci_send_cmd(&hci_write_page_timeout, 0x6000);
896             break;
897         case 9:
898             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
899             break;
900         case 10:
901             if (hci_stack->local_name){
902                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
903             } else {
904                 char hostname[30];
905 #ifdef EMBEDDED
906                 // BTstack-11:22:33:44:55:66
907                 strcpy(hostname, "BTstack ");
908                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
909                 log_info("---> Name %s", hostname);
910 #else
911                 // hostname for POSIX systems
912                 gethostname(hostname, 30);
913                 hostname[29] = '\0';
914 #endif
915                 hci_send_cmd(&hci_write_local_name, hostname);
916             }
917             break;
918         case 11:
919             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
920             if (!hci_le_supported()){
921                 // SKIP LE init for Classic only configuration
922                 hci_stack->substate = 14 << 1;
923             }
924             break;
925 
926 #ifdef HAVE_BLE
927         // LE INIT
928         case 12:
929             hci_send_cmd(&hci_le_read_buffer_size);
930             break;
931         case 13:
932             // LE Supported Host = 1, Simultaneous Host = 0
933             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
934             break;
935         case 14:
936             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
937             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
938             break;
939 #endif
940 
941         // DONE
942         case 15:
943             // done.
944             hci_stack->state = HCI_STATE_WORKING;
945             hci_emit_state();
946             break;
947         default:
948             break;
949     }
950     hci_stack->substate++;
951 }
952 
953 // avoid huge local variables
954 #ifndef EMBEDDED
955 static device_name_t device_name;
956 #endif
957 static void event_handler(uint8_t *packet, int size){
958 
959     uint16_t event_length = packet[1];
960 
961     // assert packet is complete
962     if (size != event_length + 2){
963         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
964         return;
965     }
966 
967     bd_addr_t addr;
968     bd_addr_type_t addr_type;
969     uint8_t link_type;
970     hci_con_handle_t handle;
971     hci_connection_t * conn;
972     int i;
973 
974     // log_info("HCI:EVENT:%02x", packet[0]);
975 
976     switch (packet[0]) {
977 
978         case HCI_EVENT_COMMAND_COMPLETE:
979             // get num cmd packets
980             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
981             hci_stack->num_cmd_packets = packet[2];
982 
983             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
984                 // from offset 5
985                 // status
986                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
987                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
988                 // ignore: SCO data packet len (8)
989                 hci_stack->acl_packets_total_num  = packet[9];
990                 // ignore: total num SCO packets
991                 if (hci_stack->state == HCI_STATE_INITIALIZING){
992                     // determine usable ACL payload size
993                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
994                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
995                     }
996                     log_info("hci_read_buffer_size: used size %u, count %u",
997                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num);
998                 }
999             }
1000 #ifdef HAVE_BLE
1001             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
1002                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
1003                 hci_stack->le_acl_packets_total_num  = packet[8];
1004                     // determine usable ACL payload size
1005                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1006                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1007                     }
1008                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1009             }
1010 #endif
1011             // Dump local address
1012             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
1013                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
1014                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1015                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1016             }
1017             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1018                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1019             }
1020             // Note: HCI init checks
1021             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
1022                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1023                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
1024                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
1025                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
1026                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
1027                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
1028 
1029                 // determine usable ACL packet types based buffer size and supported features
1030                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(hci_stack->acl_data_packet_length, &hci_stack->local_supported_features[0]);
1031                 log_info("packet types %04x", hci_stack->packet_types);
1032 
1033                 // Classic/LE
1034                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1035             }
1036             break;
1037 
1038         case HCI_EVENT_COMMAND_STATUS:
1039             // get num cmd packets
1040             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1041             hci_stack->num_cmd_packets = packet[3];
1042             break;
1043 
1044         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1045             int offset = 3;
1046             for (i=0; i<packet[2];i++){
1047                 handle = READ_BT_16(packet, offset);
1048                 offset += 2;
1049                 uint16_t num_packets = READ_BT_16(packet, offset);
1050                 offset += 2;
1051 
1052                 conn = hci_connection_for_handle(handle);
1053                 if (!conn){
1054                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1055                     continue;
1056                 }
1057 
1058                 if (conn->num_acl_packets_sent >= num_packets){
1059                     conn->num_acl_packets_sent -= num_packets;
1060                 } else {
1061                     log_error("hci_number_completed_packets, more slots freed then sent.");
1062                     conn->num_acl_packets_sent = 0;
1063                 }
1064                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1065             }
1066             break;
1067         }
1068         case HCI_EVENT_CONNECTION_REQUEST:
1069             bt_flip_addr(addr, &packet[2]);
1070             // TODO: eval COD 8-10
1071             link_type = packet[11];
1072             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1073             if (link_type == 1) { // ACL
1074                 conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1075                 if (!conn) {
1076                     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1077                 }
1078                 if (!conn) {
1079                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1080                     hci_stack->decline_reason = 0x0d;
1081                     BD_ADDR_COPY(hci_stack->decline_addr, addr);
1082                     break;
1083                 }
1084                 conn->state = RECEIVED_CONNECTION_REQUEST;
1085                 hci_run();
1086             } else {
1087                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
1088                 hci_stack->decline_reason = 0x0a;
1089                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1090             }
1091             break;
1092 
1093         case HCI_EVENT_CONNECTION_COMPLETE:
1094             // Connection management
1095             bt_flip_addr(addr, &packet[5]);
1096             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1097             addr_type = BD_ADDR_TYPE_CLASSIC;
1098             conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1099             if (conn) {
1100                 if (!packet[2]){
1101                     conn->state = OPEN;
1102                     conn->con_handle = READ_BT_16(packet, 3);
1103                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1104 
1105                     // restart timer
1106                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1107                     run_loop_add_timer(&conn->timeout);
1108 
1109                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1110 
1111                     hci_emit_nr_connections_changed();
1112                 } else {
1113                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1114                     uint8_t status = packet[2];
1115                     bd_addr_t bd_address;
1116                     memcpy(&bd_address, conn->address, 6);
1117 
1118                     // connection failed, remove entry
1119                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1120                     btstack_memory_hci_connection_free( conn );
1121 
1122                     // notify client if dedicated bonding
1123                     if (notify_dedicated_bonding_failed){
1124                         log_info("hci notify_dedicated_bonding_failed");
1125                         hci_emit_dedicated_bonding_result(bd_address, status);
1126                     }
1127 
1128                     // if authentication error, also delete link key
1129                     if (packet[2] == 0x05) {
1130                         hci_drop_link_key_for_bd_addr(&addr);
1131                     }
1132                 }
1133             }
1134             break;
1135 
1136         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1137             handle = READ_BT_16(packet, 3);
1138             conn = hci_connection_for_handle(handle);
1139             if (!conn) break;
1140             if (!packet[2]){
1141                 uint8_t * features = &packet[5];
1142                 if (features[6] & (1 << 3)){
1143                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1144                 }
1145             }
1146             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1147             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1148             if (conn->bonding_flags & BONDING_DEDICATED){
1149                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1150             }
1151             break;
1152 
1153         case HCI_EVENT_LINK_KEY_REQUEST:
1154             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1155             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1156             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1157             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1158             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1159             hci_run();
1160             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1161             return;
1162 
1163         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1164             bt_flip_addr(addr, &packet[2]);
1165             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1166             if (!conn) break;
1167             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1168             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1169             // Change Connection Encryption keeps link key type
1170             if (link_key_type != CHANGED_COMBINATION_KEY){
1171                 conn->link_key_type = link_key_type;
1172             }
1173             if (!hci_stack->remote_device_db) break;
1174             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
1175             // still forward event to allow dismiss of pairing dialog
1176             break;
1177         }
1178 
1179         case HCI_EVENT_PIN_CODE_REQUEST:
1180             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1181             // non-bondable mode: pin code negative reply will be sent
1182             if (!hci_stack->bondable){
1183                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1184                 hci_run();
1185                 return;
1186             }
1187             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1188             if (!hci_stack->remote_device_db) break;
1189             bt_flip_addr(addr, &packet[2]);
1190             hci_stack->remote_device_db->delete_link_key(&addr);
1191             break;
1192 
1193         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1194             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1195             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1196             break;
1197 
1198         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1199             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1200             if (!hci_stack->ssp_auto_accept) break;
1201             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1202             break;
1203 
1204         case HCI_EVENT_USER_PASSKEY_REQUEST:
1205             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1206             if (!hci_stack->ssp_auto_accept) break;
1207             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1208             break;
1209 
1210         case HCI_EVENT_ENCRYPTION_CHANGE:
1211             handle = READ_BT_16(packet, 3);
1212             conn = hci_connection_for_handle(handle);
1213             if (!conn) break;
1214             if (packet[2] == 0) {
1215                 if (packet[5]){
1216                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1217                 } else {
1218                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1219                 }
1220             }
1221             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1222             break;
1223 
1224         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1225             handle = READ_BT_16(packet, 3);
1226             conn = hci_connection_for_handle(handle);
1227             if (!conn) break;
1228 
1229             // dedicated bonding: send result and disconnect
1230             if (conn->bonding_flags & BONDING_DEDICATED){
1231                 conn->bonding_flags &= ~BONDING_DEDICATED;
1232                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1233                 conn->bonding_status = packet[2];
1234                 break;
1235             }
1236 
1237             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1238                 // link key sufficient for requested security
1239                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1240                 break;
1241             }
1242             // not enough
1243             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1244             break;
1245 
1246 #ifndef EMBEDDED
1247         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1248             if (!hci_stack->remote_device_db) break;
1249             if (packet[2]) break; // status not ok
1250             bt_flip_addr(addr, &packet[3]);
1251             // fix for invalid remote names - terminate on 0xff
1252             for (i=0; i<248;i++){
1253                 if (packet[9+i] == 0xff){
1254                     packet[9+i] = 0;
1255                     break;
1256                 }
1257             }
1258             memset(&device_name, 0, sizeof(device_name_t));
1259             strncpy((char*) device_name, (char*) &packet[9], 248);
1260             hci_stack->remote_device_db->put_name(&addr, &device_name);
1261             break;
1262 
1263         case HCI_EVENT_INQUIRY_RESULT:
1264         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1265             if (!hci_stack->remote_device_db) break;
1266             // first send inq result packet
1267             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1268             // then send cached remote names
1269             int offset = 3;
1270             for (i=0; i<packet[2];i++){
1271                 bt_flip_addr(addr, &packet[offset]);
1272                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1273                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
1274                     hci_emit_remote_name_cached(&addr, &device_name);
1275                 }
1276             }
1277             return;
1278         }
1279 #endif
1280 
1281         // HCI_EVENT_DISCONNECTION_COMPLETE
1282         // has been moved down, to first notify stack before shutting connection down
1283 
1284         case HCI_EVENT_HARDWARE_ERROR:
1285             if(hci_stack->control && hci_stack->control->hw_error){
1286                 (*hci_stack->control->hw_error)();
1287             } else {
1288                 // if no special requests, just reboot stack
1289                 hci_power_control_off();
1290                 hci_power_control_on();
1291             }
1292             break;
1293 
1294         case DAEMON_EVENT_HCI_PACKET_SENT:
1295             // release packet buffer only for asynchronous transport and if there are not further fragements
1296             if (hci_transport_synchronous()) break;
1297             if (hci_stack->acl_fragmentation_total_size) break;
1298             hci_release_packet_buffer();
1299             break;
1300 
1301 #ifdef HAVE_BLE
1302         case HCI_EVENT_LE_META:
1303             switch (packet[2]){
1304                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1305                     log_info("advertising report received");
1306                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1307                     le_handle_advertisement_report(packet, size);
1308                     break;
1309                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1310                     // Connection management
1311                     bt_flip_addr(addr, &packet[8]);
1312                     addr_type = (bd_addr_type_t)packet[7];
1313                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1314                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1315                     conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1316                     if (packet[3]){
1317                         if (conn){
1318                             // outgoing connection failed, remove entry
1319                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1320                             btstack_memory_hci_connection_free( conn );
1321                         }
1322                         // if authentication error, also delete link key
1323                         if (packet[3] == 0x05) {
1324                             hci_drop_link_key_for_bd_addr(&addr);
1325                         }
1326                         break;
1327                     }
1328                     if (!conn){
1329                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1330                     }
1331                     if (!conn){
1332                         // no memory
1333                         break;
1334                     }
1335 
1336                     conn->state = OPEN;
1337                     conn->con_handle = READ_BT_16(packet, 4);
1338 
1339                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1340 
1341                     // restart timer
1342                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1343                     // run_loop_add_timer(&conn->timeout);
1344 
1345                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1346 
1347                     hci_emit_nr_connections_changed();
1348                     break;
1349 
1350             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1351 
1352                 default:
1353                     break;
1354             }
1355             break;
1356 #endif
1357         default:
1358             break;
1359     }
1360 
1361     // handle BT initialization
1362     if (hci_stack->state == HCI_STATE_INITIALIZING){
1363         hci_initializing_event_handler(packet, size);
1364     }
1365 
1366     // help with BT sleep
1367     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1368         && hci_stack->substate == 1
1369         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1370         hci_stack->substate++;
1371     }
1372 
1373     // notify upper stack
1374     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1375 
1376     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1377     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1378         if (!packet[2]){
1379             handle = READ_BT_16(packet, 3);
1380             hci_connection_t * conn = hci_connection_for_handle(handle);
1381             if (conn) {
1382                 uint8_t status = conn->bonding_status;
1383                 uint16_t flags = conn->bonding_flags;
1384                 bd_addr_t bd_address;
1385                 memcpy(&bd_address, conn->address, 6);
1386                 hci_shutdown_connection(conn);
1387                 // connection struct is gone, don't access anymore
1388                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1389                     hci_emit_dedicated_bonding_result(bd_address, status);
1390                 }
1391             }
1392         }
1393     }
1394 
1395 	// execute main loop
1396 	hci_run();
1397 }
1398 
1399 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1400     hci_dump_packet(packet_type, 1, packet, size);
1401     switch (packet_type) {
1402         case HCI_EVENT_PACKET:
1403             event_handler(packet, size);
1404             break;
1405         case HCI_ACL_DATA_PACKET:
1406             acl_handler(packet, size);
1407             break;
1408         default:
1409             break;
1410     }
1411 }
1412 
1413 /** Register HCI packet handlers */
1414 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1415     hci_stack->packet_handler = handler;
1416 }
1417 
1418 static void hci_state_reset(){
1419     // no connections yet
1420     hci_stack->connections = NULL;
1421 
1422     // keep discoverable/connectable as this has been requested by the client(s)
1423     // hci_stack->discoverable = 0;
1424     // hci_stack->connectable = 0;
1425     // hci_stack->bondable = 1;
1426 
1427     // buffer is free
1428     hci_stack->hci_packet_buffer_reserved = 0;
1429 
1430     // no pending cmds
1431     hci_stack->decline_reason = 0;
1432     hci_stack->new_scan_enable_value = 0xff;
1433 
1434     // LE
1435     hci_stack->adv_addr_type = 0;
1436     memset(hci_stack->adv_address, 0, 6);
1437     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1438     hci_stack->le_scan_type = 0xff;
1439     hci_stack->le_connection_parameter_range.le_conn_interval_min = 0x0006;
1440     hci_stack->le_connection_parameter_range.le_conn_interval_max = 0x0C80;
1441     hci_stack->le_connection_parameter_range.le_conn_latency_min = 0x0000;
1442     hci_stack->le_connection_parameter_range.le_conn_latency_max = 0x03E8;
1443     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = 0x000A;
1444     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 0x0C80;
1445 }
1446 
1447 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1448 
1449 #ifdef HAVE_MALLOC
1450     if (!hci_stack) {
1451         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1452     }
1453 #else
1454     hci_stack = &hci_stack_static;
1455 #endif
1456     memset(hci_stack, 0, sizeof(hci_stack_t));
1457 
1458     // reference to use transport layer implementation
1459     hci_stack->hci_transport = transport;
1460 
1461     // references to used control implementation
1462     hci_stack->control = control;
1463 
1464     // reference to used config
1465     hci_stack->config = config;
1466 
1467     // higher level handler
1468     hci_stack->packet_handler = dummy_handler;
1469 
1470     // store and open remote device db
1471     hci_stack->remote_device_db = remote_device_db;
1472     if (hci_stack->remote_device_db) {
1473         hci_stack->remote_device_db->open();
1474     }
1475 
1476     // max acl payload size defined in config.h
1477     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1478 
1479     // register packet handlers with transport
1480     transport->register_packet_handler(&packet_handler);
1481 
1482     hci_stack->state = HCI_STATE_OFF;
1483 
1484     // class of device
1485     hci_stack->class_of_device = 0x007a020c; // Smartphone
1486 
1487     // bondable by default
1488     hci_stack->bondable = 1;
1489 
1490     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1491     hci_stack->ssp_enable = 1;
1492     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1493     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1494     hci_stack->ssp_auto_accept = 1;
1495 
1496     hci_state_reset();
1497 }
1498 
1499 void hci_close(){
1500     // close remote device db
1501     if (hci_stack->remote_device_db) {
1502         hci_stack->remote_device_db->close();
1503     }
1504     while (hci_stack->connections) {
1505         // cancel all l2cap connections
1506         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1507         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1508     }
1509     hci_power_control(HCI_POWER_OFF);
1510 
1511 #ifdef HAVE_MALLOC
1512     free(hci_stack);
1513 #endif
1514     hci_stack = NULL;
1515 }
1516 
1517 void hci_set_class_of_device(uint32_t class_of_device){
1518     hci_stack->class_of_device = class_of_device;
1519 }
1520 
1521 void hci_disable_l2cap_timeout_check(){
1522     disable_l2cap_timeouts = 1;
1523 }
1524 // State-Module-Driver overview
1525 // state                    module  low-level
1526 // HCI_STATE_OFF             off      close
1527 // HCI_STATE_INITIALIZING,   on       open
1528 // HCI_STATE_WORKING,        on       open
1529 // HCI_STATE_HALTING,        on       open
1530 // HCI_STATE_SLEEPING,    off/sleep   close
1531 // HCI_STATE_FALLING_ASLEEP  on       open
1532 
1533 static int hci_power_control_on(void){
1534 
1535     // power on
1536     int err = 0;
1537     if (hci_stack->control && hci_stack->control->on){
1538         err = (*hci_stack->control->on)(hci_stack->config);
1539     }
1540     if (err){
1541         log_error( "POWER_ON failed");
1542         hci_emit_hci_open_failed();
1543         return err;
1544     }
1545 
1546     // open low-level device
1547     err = hci_stack->hci_transport->open(hci_stack->config);
1548     if (err){
1549         log_error( "HCI_INIT failed, turning Bluetooth off again");
1550         if (hci_stack->control && hci_stack->control->off){
1551             (*hci_stack->control->off)(hci_stack->config);
1552         }
1553         hci_emit_hci_open_failed();
1554         return err;
1555     }
1556     return 0;
1557 }
1558 
1559 static void hci_power_control_off(void){
1560 
1561     log_info("hci_power_control_off");
1562 
1563     // close low-level device
1564     hci_stack->hci_transport->close(hci_stack->config);
1565 
1566     log_info("hci_power_control_off - hci_transport closed");
1567 
1568     // power off
1569     if (hci_stack->control && hci_stack->control->off){
1570         (*hci_stack->control->off)(hci_stack->config);
1571     }
1572 
1573     log_info("hci_power_control_off - control closed");
1574 
1575     hci_stack->state = HCI_STATE_OFF;
1576 }
1577 
1578 static void hci_power_control_sleep(void){
1579 
1580     log_info("hci_power_control_sleep");
1581 
1582 #if 0
1583     // don't close serial port during sleep
1584 
1585     // close low-level device
1586     hci_stack->hci_transport->close(hci_stack->config);
1587 #endif
1588 
1589     // sleep mode
1590     if (hci_stack->control && hci_stack->control->sleep){
1591         (*hci_stack->control->sleep)(hci_stack->config);
1592     }
1593 
1594     hci_stack->state = HCI_STATE_SLEEPING;
1595 }
1596 
1597 static int hci_power_control_wake(void){
1598 
1599     log_info("hci_power_control_wake");
1600 
1601     // wake on
1602     if (hci_stack->control && hci_stack->control->wake){
1603         (*hci_stack->control->wake)(hci_stack->config);
1604     }
1605 
1606 #if 0
1607     // open low-level device
1608     int err = hci_stack->hci_transport->open(hci_stack->config);
1609     if (err){
1610         log_error( "HCI_INIT failed, turning Bluetooth off again");
1611         if (hci_stack->control && hci_stack->control->off){
1612             (*hci_stack->control->off)(hci_stack->config);
1613         }
1614         hci_emit_hci_open_failed();
1615         return err;
1616     }
1617 #endif
1618 
1619     return 0;
1620 }
1621 
1622 static void hci_power_transition_to_initializing(void){
1623     // set up state machine
1624     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1625     hci_stack->hci_packet_buffer_reserved = 0;
1626     hci_stack->state = HCI_STATE_INITIALIZING;
1627     hci_stack->substate = 0;
1628 }
1629 
1630 int hci_power_control(HCI_POWER_MODE power_mode){
1631 
1632     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1633 
1634     int err = 0;
1635     switch (hci_stack->state){
1636 
1637         case HCI_STATE_OFF:
1638             switch (power_mode){
1639                 case HCI_POWER_ON:
1640                     err = hci_power_control_on();
1641                     if (err) {
1642                         log_error("hci_power_control_on() error %u", err);
1643                         return err;
1644                     }
1645                     hci_power_transition_to_initializing();
1646                     break;
1647                 case HCI_POWER_OFF:
1648                     // do nothing
1649                     break;
1650                 case HCI_POWER_SLEEP:
1651                     // do nothing (with SLEEP == OFF)
1652                     break;
1653             }
1654             break;
1655 
1656         case HCI_STATE_INITIALIZING:
1657             switch (power_mode){
1658                 case HCI_POWER_ON:
1659                     // do nothing
1660                     break;
1661                 case HCI_POWER_OFF:
1662                     // no connections yet, just turn it off
1663                     hci_power_control_off();
1664                     break;
1665                 case HCI_POWER_SLEEP:
1666                     // no connections yet, just turn it off
1667                     hci_power_control_sleep();
1668                     break;
1669             }
1670             break;
1671 
1672         case HCI_STATE_WORKING:
1673             switch (power_mode){
1674                 case HCI_POWER_ON:
1675                     // do nothing
1676                     break;
1677                 case HCI_POWER_OFF:
1678                     // see hci_run
1679                     hci_stack->state = HCI_STATE_HALTING;
1680                     break;
1681                 case HCI_POWER_SLEEP:
1682                     // see hci_run
1683                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1684                     hci_stack->substate = 0;
1685                     break;
1686             }
1687             break;
1688 
1689         case HCI_STATE_HALTING:
1690             switch (power_mode){
1691                 case HCI_POWER_ON:
1692                     hci_power_transition_to_initializing();
1693                     break;
1694                 case HCI_POWER_OFF:
1695                     // do nothing
1696                     break;
1697                 case HCI_POWER_SLEEP:
1698                     // see hci_run
1699                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1700                     hci_stack->substate = 0;
1701                     break;
1702             }
1703             break;
1704 
1705         case HCI_STATE_FALLING_ASLEEP:
1706             switch (power_mode){
1707                 case HCI_POWER_ON:
1708 
1709 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1710                     // nothing to do, if H4 supports power management
1711                     if (bt_control_iphone_power_management_enabled()){
1712                         hci_stack->state = HCI_STATE_INITIALIZING;
1713                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1714                         break;
1715                     }
1716 #endif
1717                     hci_power_transition_to_initializing();
1718                     break;
1719                 case HCI_POWER_OFF:
1720                     // see hci_run
1721                     hci_stack->state = HCI_STATE_HALTING;
1722                     break;
1723                 case HCI_POWER_SLEEP:
1724                     // do nothing
1725                     break;
1726             }
1727             break;
1728 
1729         case HCI_STATE_SLEEPING:
1730             switch (power_mode){
1731                 case HCI_POWER_ON:
1732 
1733 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1734                     // nothing to do, if H4 supports power management
1735                     if (bt_control_iphone_power_management_enabled()){
1736                         hci_stack->state = HCI_STATE_INITIALIZING;
1737                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1738                         hci_update_scan_enable();
1739                         break;
1740                     }
1741 #endif
1742                     err = hci_power_control_wake();
1743                     if (err) return err;
1744                     hci_power_transition_to_initializing();
1745                     break;
1746                 case HCI_POWER_OFF:
1747                     hci_stack->state = HCI_STATE_HALTING;
1748                     break;
1749                 case HCI_POWER_SLEEP:
1750                     // do nothing
1751                     break;
1752             }
1753             break;
1754     }
1755 
1756     // create internal event
1757 	hci_emit_state();
1758 
1759 	// trigger next/first action
1760 	hci_run();
1761 
1762     return 0;
1763 }
1764 
1765 static void hci_update_scan_enable(void){
1766     // 2 = page scan, 1 = inq scan
1767     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1768     hci_run();
1769 }
1770 
1771 void hci_discoverable_control(uint8_t enable){
1772     if (enable) enable = 1; // normalize argument
1773 
1774     if (hci_stack->discoverable == enable){
1775         hci_emit_discoverable_enabled(hci_stack->discoverable);
1776         return;
1777     }
1778 
1779     hci_stack->discoverable = enable;
1780     hci_update_scan_enable();
1781 }
1782 
1783 void hci_connectable_control(uint8_t enable){
1784     if (enable) enable = 1; // normalize argument
1785 
1786     // don't emit event
1787     if (hci_stack->connectable == enable) return;
1788 
1789     hci_stack->connectable = enable;
1790     hci_update_scan_enable();
1791 }
1792 
1793 bd_addr_t * hci_local_bd_addr(void){
1794     return &hci_stack->local_bd_addr;
1795 }
1796 
1797 void hci_run(){
1798 
1799     hci_connection_t * connection;
1800     linked_item_t * it;
1801 
1802     // send continuation fragments first, as they block the prepared packet buffer
1803     if (hci_stack->acl_fragmentation_total_size > 0) {
1804         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1805         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1806             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1807             if (connection) {
1808                 hci_send_acl_packet_fragments(connection);
1809                 return;
1810             }
1811             // connection gone -> discard further fragments
1812             hci_stack->acl_fragmentation_total_size = 0;
1813             hci_stack->acl_fragmentation_pos = 0;
1814         }
1815     }
1816 
1817     if (!hci_can_send_command_packet_now()) return;
1818 
1819     // global/non-connection oriented commands
1820 
1821     // decline incoming connections
1822     if (hci_stack->decline_reason){
1823         uint8_t reason = hci_stack->decline_reason;
1824         hci_stack->decline_reason = 0;
1825         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1826         return;
1827     }
1828 
1829     // send scan enable
1830     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1831         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1832         hci_stack->new_scan_enable_value = 0xff;
1833         return;
1834     }
1835 
1836 #ifdef HAVE_BLE
1837     // handle le scan
1838     if (hci_stack->state == HCI_STATE_WORKING){
1839         switch(hci_stack->le_scanning_state){
1840             case LE_START_SCAN:
1841                 hci_stack->le_scanning_state = LE_SCANNING;
1842                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1843                 return;
1844 
1845             case LE_STOP_SCAN:
1846                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1847                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1848                 return;
1849             default:
1850                 break;
1851         }
1852         if (hci_stack->le_scan_type != 0xff){
1853             // defaults: active scanning, accept all advertisement packets
1854             int scan_type = hci_stack->le_scan_type;
1855             hci_stack->le_scan_type = 0xff;
1856             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);
1857             return;
1858         }
1859     }
1860 #endif
1861 
1862     // send pending HCI commands
1863     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1864         connection = (hci_connection_t *) it;
1865 
1866         switch(connection->state){
1867             case SEND_CREATE_CONNECTION:
1868                 switch(connection->address_type){
1869                     case BD_ADDR_TYPE_CLASSIC:
1870                         log_info("sending hci_create_connection");
1871                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1872                         break;
1873                     default:
1874 #ifdef HAVE_BLE
1875                         log_info("sending hci_le_create_connection");
1876                         hci_send_cmd(&hci_le_create_connection,
1877                                      0x0060,    // scan interval: 60 ms
1878                                      0x0030,    // scan interval: 30 ms
1879                                      0,         // don't use whitelist
1880                                      connection->address_type, // peer address type
1881                                      connection->address,      // peer bd addr
1882                                      hci_stack->adv_addr_type, // our addr type:
1883                                      0x0008,    // conn interval min
1884                                      0x0018,    // conn interval max
1885                                      0,         // conn latency
1886                                      0x0048,    // supervision timeout
1887                                      0x0001,    // min ce length
1888                                      0x0001     // max ce length
1889                                      );
1890 
1891                         connection->state = SENT_CREATE_CONNECTION;
1892 #endif
1893                         break;
1894                 }
1895                 return;
1896 
1897             case RECEIVED_CONNECTION_REQUEST:
1898                 log_info("sending hci_accept_connection_request");
1899                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1900                 hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1901                 return;
1902 
1903 #ifdef HAVE_BLE
1904             case SEND_CANCEL_CONNECTION:
1905                 connection->state = SENT_CANCEL_CONNECTION;
1906                 hci_send_cmd(&hci_le_create_connection_cancel);
1907                 return;
1908 #endif
1909             case SEND_DISCONNECT:
1910                 connection->state = SENT_DISCONNECT;
1911                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
1912                 return;
1913 
1914             default:
1915                 break;
1916         }
1917 
1918         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1919             log_info("responding to link key request");
1920             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1921             link_key_t link_key;
1922             link_key_type_t link_key_type;
1923             if ( hci_stack->remote_device_db
1924               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
1925               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
1926                connection->link_key_type = link_key_type;
1927                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1928             } else {
1929                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1930             }
1931             return;
1932         }
1933 
1934         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
1935             log_info("denying to pin request");
1936             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
1937             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1938             return;
1939         }
1940 
1941         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1942             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1943             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
1944             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
1945                 // tweak authentication requirements
1946                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
1947                 if (connection->bonding_flags & BONDING_DEDICATED){
1948                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
1949                 }
1950                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
1951                     authreq |= 1;
1952                 }
1953                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
1954             } else {
1955                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1956             }
1957             return;
1958         }
1959 
1960         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1961             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1962             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1963             return;
1964         }
1965 
1966         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1967             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1968             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1969             return;
1970         }
1971 
1972         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1973             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1974             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1975             return;
1976         }
1977 
1978         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
1979             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
1980             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
1981             return;
1982         }
1983         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
1984             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
1985             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
1986             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
1987             return;
1988         }
1989         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
1990             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
1991             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
1992             return;
1993         }
1994         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
1995             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
1996             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
1997             return;
1998         }
1999 
2000 #ifdef HAVE_BLE
2001         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2002             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2003 
2004             uint16_t connection_interval_min = connection->le_conn_interval_min;
2005             connection->le_conn_interval_min = 0;
2006             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2007                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2008                 0x0000, 0xffff);
2009         }
2010 #endif
2011     }
2012 
2013     switch (hci_stack->state){
2014         case HCI_STATE_INITIALIZING:
2015             hci_initializing_state_machine();
2016             break;
2017 
2018         case HCI_STATE_HALTING:
2019 
2020             log_info("HCI_STATE_HALTING");
2021             // close all open connections
2022             connection =  (hci_connection_t *) hci_stack->connections;
2023             if (connection){
2024 
2025                 // send disconnect
2026                 if (!hci_can_send_command_packet_now()) return;
2027 
2028                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2029                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2030 
2031                 // send disconnected event right away - causes higher layer connections to get closed, too.
2032                 hci_shutdown_connection(connection);
2033                 return;
2034             }
2035             log_info("HCI_STATE_HALTING, calling off");
2036 
2037             // switch mode
2038             hci_power_control_off();
2039 
2040             log_info("HCI_STATE_HALTING, emitting state");
2041             hci_emit_state();
2042             log_info("HCI_STATE_HALTING, done");
2043             break;
2044 
2045         case HCI_STATE_FALLING_ASLEEP:
2046             switch(hci_stack->substate) {
2047                 case 0:
2048                     log_info("HCI_STATE_FALLING_ASLEEP");
2049                     // close all open connections
2050                     connection =  (hci_connection_t *) hci_stack->connections;
2051 
2052 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2053                     // don't close connections, if H4 supports power management
2054                     if (bt_control_iphone_power_management_enabled()){
2055                         connection = NULL;
2056                     }
2057 #endif
2058                     if (connection){
2059 
2060                         // send disconnect
2061                         if (!hci_can_send_command_packet_now()) return;
2062 
2063                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2064                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2065 
2066                         // send disconnected event right away - causes higher layer connections to get closed, too.
2067                         hci_shutdown_connection(connection);
2068                         return;
2069                     }
2070 
2071                     if (hci_classic_supported()){
2072                         // disable page and inquiry scan
2073                         if (!hci_can_send_command_packet_now()) return;
2074 
2075                         log_info("HCI_STATE_HALTING, disabling inq scans");
2076                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2077 
2078                         // continue in next sub state
2079                         hci_stack->substate++;
2080                         break;
2081                     }
2082                     // fall through for ble-only chips
2083 
2084                 case 2:
2085                     log_info("HCI_STATE_HALTING, calling sleep");
2086 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2087                     // don't actually go to sleep, if H4 supports power management
2088                     if (bt_control_iphone_power_management_enabled()){
2089                         // SLEEP MODE reached
2090                         hci_stack->state = HCI_STATE_SLEEPING;
2091                         hci_emit_state();
2092                         break;
2093                     }
2094 #endif
2095                     // switch mode
2096                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2097                     hci_emit_state();
2098                     break;
2099 
2100                 default:
2101                     break;
2102             }
2103             break;
2104 
2105         default:
2106             break;
2107     }
2108 }
2109 
2110 int hci_send_cmd_packet(uint8_t *packet, int size){
2111     bd_addr_t addr;
2112     hci_connection_t * conn;
2113     // house-keeping
2114 
2115     // create_connection?
2116     if (IS_COMMAND(packet, hci_create_connection)){
2117         bt_flip_addr(addr, &packet[3]);
2118         log_info("Create_connection to %s", bd_addr_to_str(addr));
2119 
2120         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2121         if (!conn){
2122             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2123             if (!conn){
2124                 // notify client that alloc failed
2125                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2126                 return 0; // don't sent packet to controller
2127             }
2128             conn->state = SEND_CREATE_CONNECTION;
2129         }
2130         log_info("conn state %u", conn->state);
2131         switch (conn->state){
2132             // if connection active exists
2133             case OPEN:
2134                 // and OPEN, emit connection complete command, don't send to controller
2135                 hci_emit_connection_complete(conn, 0);
2136                 return 0;
2137             case SEND_CREATE_CONNECTION:
2138                 // connection created by hci, e.g. dedicated bonding
2139                 break;
2140             default:
2141                 // otherwise, just ignore as it is already in the open process
2142                 return 0;
2143         }
2144         conn->state = SENT_CREATE_CONNECTION;
2145     }
2146 
2147     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2148         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2149     }
2150     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2151         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2152     }
2153 
2154     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2155         if (hci_stack->remote_device_db){
2156             bt_flip_addr(addr, &packet[3]);
2157             hci_stack->remote_device_db->delete_link_key(&addr);
2158         }
2159     }
2160 
2161     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2162     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2163         bt_flip_addr(addr, &packet[3]);
2164         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2165         if (conn){
2166             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2167         }
2168     }
2169 
2170     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2171     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2172     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2173     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2174         bt_flip_addr(addr, &packet[3]);
2175         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2176         if (conn){
2177             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2178         }
2179     }
2180 
2181 #ifdef HAVE_BLE
2182     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2183         hci_stack->adv_addr_type = packet[8];
2184     }
2185     if (IS_COMMAND(packet, hci_le_set_random_address)){
2186         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2187     }
2188 #endif
2189 
2190     hci_stack->num_cmd_packets--;
2191 
2192     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2193     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2194 
2195     // release packet buffer for synchronous transport implementations
2196     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2197         hci_stack->hci_packet_buffer_reserved = 0;
2198     }
2199 
2200     return err;
2201 }
2202 
2203 // disconnect because of security block
2204 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2205     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2206     if (!connection) return;
2207     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2208 }
2209 
2210 
2211 // Configure Secure Simple Pairing
2212 
2213 // enable will enable SSP during init
2214 void hci_ssp_set_enable(int enable){
2215     hci_stack->ssp_enable = enable;
2216 }
2217 
2218 int hci_local_ssp_activated(){
2219     return hci_ssp_supported() && hci_stack->ssp_enable;
2220 }
2221 
2222 // if set, BTstack will respond to io capability request using authentication requirement
2223 void hci_ssp_set_io_capability(int io_capability){
2224     hci_stack->ssp_io_capability = io_capability;
2225 }
2226 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2227     hci_stack->ssp_authentication_requirement = authentication_requirement;
2228 }
2229 
2230 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2231 void hci_ssp_set_auto_accept(int auto_accept){
2232     hci_stack->ssp_auto_accept = auto_accept;
2233 }
2234 
2235 /**
2236  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2237  */
2238 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2239 
2240     if (!hci_can_send_command_packet_now()){
2241         log_error("hci_send_cmd called but cannot send packet now");
2242         return 0;
2243     }
2244 
2245     // for HCI INITIALIZATION
2246     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2247     hci_stack->last_cmd_opcode = cmd->opcode;
2248 
2249     hci_reserve_packet_buffer();
2250     uint8_t * packet = hci_stack->hci_packet_buffer;
2251 
2252     va_list argptr;
2253     va_start(argptr, cmd);
2254     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2255     va_end(argptr);
2256 
2257     return hci_send_cmd_packet(packet, size);
2258 }
2259 
2260 // Create various non-HCI events.
2261 // TODO: generalize, use table similar to hci_create_command
2262 
2263 void hci_emit_state(){
2264     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2265     uint8_t event[3];
2266     event[0] = BTSTACK_EVENT_STATE;
2267     event[1] = sizeof(event) - 2;
2268     event[2] = hci_stack->state;
2269     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2270     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2271 }
2272 
2273 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2274     uint8_t event[13];
2275     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2276     event[1] = sizeof(event) - 2;
2277     event[2] = status;
2278     bt_store_16(event, 3, conn->con_handle);
2279     bt_flip_addr(&event[5], conn->address);
2280     event[11] = 1; // ACL connection
2281     event[12] = 0; // encryption disabled
2282     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2283     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2284 }
2285 
2286 void hci_emit_le_connection_complete(hci_connection_t *conn, uint8_t status){
2287     uint8_t event[21];
2288     event[0] = HCI_EVENT_LE_META;
2289     event[1] = sizeof(event) - 2;
2290     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2291     event[3] = status;
2292     bt_store_16(event, 4, conn->con_handle);
2293     event[6] = 0; // TODO: role
2294     event[7] = conn->address_type;
2295     bt_flip_addr(&event[8], conn->address);
2296     bt_store_16(event, 14, 0); // interval
2297     bt_store_16(event, 16, 0); // latency
2298     bt_store_16(event, 18, 0); // supervision timeout
2299     event[20] = 0; // master clock accuracy
2300     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2301     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2302 }
2303 
2304 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2305     uint8_t event[6];
2306     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2307     event[1] = sizeof(event) - 2;
2308     event[2] = 0; // status = OK
2309     bt_store_16(event, 3, handle);
2310     event[5] = reason;
2311     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2312     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2313 }
2314 
2315 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2316     if (disable_l2cap_timeouts) return;
2317     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2318     uint8_t event[4];
2319     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2320     event[1] = sizeof(event) - 2;
2321     bt_store_16(event, 2, conn->con_handle);
2322     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2323     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2324 }
2325 
2326 void hci_emit_nr_connections_changed(){
2327     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2328     uint8_t event[3];
2329     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2330     event[1] = sizeof(event) - 2;
2331     event[2] = nr_hci_connections();
2332     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2333     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2334 }
2335 
2336 void hci_emit_hci_open_failed(){
2337     log_info("BTSTACK_EVENT_POWERON_FAILED");
2338     uint8_t event[2];
2339     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2340     event[1] = sizeof(event) - 2;
2341     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2342     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2343 }
2344 
2345 #ifndef EMBEDDED
2346 void hci_emit_btstack_version() {
2347     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2348     uint8_t event[6];
2349     event[0] = BTSTACK_EVENT_VERSION;
2350     event[1] = sizeof(event) - 2;
2351     event[2] = BTSTACK_MAJOR;
2352     event[3] = BTSTACK_MINOR;
2353     bt_store_16(event, 4, BTSTACK_REVISION);
2354     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2355     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2356 }
2357 #endif
2358 
2359 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2360     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2361     uint8_t event[3];
2362     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2363     event[1] = sizeof(event) - 2;
2364     event[2] = enabled;
2365     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2366     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2367 }
2368 
2369 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
2370     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2371     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2372     event[1] = sizeof(event) - 2 - 1;
2373     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2374     bt_flip_addr(&event[3], *addr);
2375     memcpy(&event[9], name, 248);
2376 
2377     event[9+248] = 0;   // assert \0 for log_info
2378     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
2379 
2380     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2381     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2382 }
2383 
2384 void hci_emit_discoverable_enabled(uint8_t enabled){
2385     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2386     uint8_t event[3];
2387     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2388     event[1] = sizeof(event) - 2;
2389     event[2] = enabled;
2390     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2391     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2392 }
2393 
2394 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2395     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2396     uint8_t event[5];
2397     int pos = 0;
2398     event[pos++] = GAP_SECURITY_LEVEL;
2399     event[pos++] = sizeof(event) - 2;
2400     bt_store_16(event, 2, con_handle);
2401     pos += 2;
2402     event[pos++] = level;
2403     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2404     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2405 }
2406 
2407 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2408     log_info("hci_emit_dedicated_bonding_result %u ", status);
2409     uint8_t event[9];
2410     int pos = 0;
2411     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2412     event[pos++] = sizeof(event) - 2;
2413     event[pos++] = status;
2414     bt_flip_addr( * (bd_addr_t *) &event[pos], address);
2415     pos += 6;
2416     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2417     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2418 }
2419 
2420 // query if remote side supports SSP
2421 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2422     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2423     if (!connection) return 0;
2424     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2425 }
2426 
2427 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2428     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2429 }
2430 
2431 // GAP API
2432 /**
2433  * @bbrief enable/disable bonding. default is enabled
2434  * @praram enabled
2435  */
2436 void gap_set_bondable_mode(int enable){
2437     hci_stack->bondable = enable ? 1 : 0;
2438 }
2439 
2440 /**
2441  * @brief map link keys to security levels
2442  */
2443 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2444     switch (link_key_type){
2445         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2446             return LEVEL_4;
2447         case COMBINATION_KEY:
2448         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2449             return LEVEL_3;
2450         default:
2451             return LEVEL_2;
2452     }
2453 }
2454 
2455 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2456     if (!connection) return LEVEL_0;
2457     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2458     return gap_security_level_for_link_key_type(connection->link_key_type);
2459 }
2460 
2461 
2462 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2463     log_info("gap_mitm_protection_required_for_security_level %u", level);
2464     return level > LEVEL_2;
2465 }
2466 
2467 /**
2468  * @brief get current security level
2469  */
2470 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2471     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2472     if (!connection) return LEVEL_0;
2473     return gap_security_level_for_connection(connection);
2474 }
2475 
2476 /**
2477  * @brief request connection to device to
2478  * @result GAP_AUTHENTICATION_RESULT
2479  */
2480 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2481     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2482     if (!connection){
2483         hci_emit_security_level(con_handle, LEVEL_0);
2484         return;
2485     }
2486     gap_security_level_t current_level = gap_security_level(con_handle);
2487     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2488     if (current_level >= requested_level){
2489         hci_emit_security_level(con_handle, current_level);
2490         return;
2491     }
2492 
2493     connection->requested_security_level = requested_level;
2494 
2495     // would enabling ecnryption suffice (>= LEVEL_2)?
2496     if (hci_stack->remote_device_db){
2497         link_key_type_t link_key_type;
2498         link_key_t      link_key;
2499         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2500             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2501                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2502                 return;
2503             }
2504         }
2505     }
2506 
2507     // try to authenticate connection
2508     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2509     hci_run();
2510 }
2511 
2512 /**
2513  * @brief start dedicated bonding with device. disconnect after bonding
2514  * @param device
2515  * @param request MITM protection
2516  * @result GAP_DEDICATED_BONDING_COMPLETE
2517  */
2518 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2519 
2520     // create connection state machine
2521     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2522 
2523     if (!connection){
2524         return BTSTACK_MEMORY_ALLOC_FAILED;
2525     }
2526 
2527     // delete linkn key
2528     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2529 
2530     // configure LEVEL_2/3, dedicated bonding
2531     connection->state = SEND_CREATE_CONNECTION;
2532     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2533     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2534     connection->bonding_flags = BONDING_DEDICATED;
2535 
2536     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2537 
2538     // handle: connnection failure (connection complete != ok)
2539     // handle: authentication failure
2540     // handle: disconnect on done
2541 
2542     hci_run();
2543 
2544     return 0;
2545 }
2546 
2547 void gap_set_local_name(const char * local_name){
2548     hci_stack->local_name = local_name;
2549 }
2550 
2551 le_command_status_t le_central_start_scan(){
2552     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2553     hci_stack->le_scanning_state = LE_START_SCAN;
2554     hci_run();
2555     return BLE_PERIPHERAL_OK;
2556 }
2557 
2558 le_command_status_t le_central_stop_scan(){
2559     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2560     hci_stack->le_scanning_state = LE_STOP_SCAN;
2561     hci_run();
2562     return BLE_PERIPHERAL_OK;
2563 }
2564 
2565 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2566     hci_stack->le_scan_type     = scan_type;
2567     hci_stack->le_scan_interval = scan_interval;
2568     hci_stack->le_scan_window   = scan_window;
2569     hci_run();
2570 }
2571 
2572 le_command_status_t le_central_connect(bd_addr_t * addr, bd_addr_type_t addr_type){
2573     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2574     if (!conn){
2575         log_info("le_central_connect: no connection exists yet, creating context");
2576         conn = create_connection_for_bd_addr_and_type(*addr, addr_type);
2577         if (!conn){
2578             // notify client that alloc failed
2579             hci_emit_le_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2580             log_info("le_central_connect: failed to alloc context");
2581             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2582         }
2583         conn->state = SEND_CREATE_CONNECTION;
2584         log_info("le_central_connect: send create connection next");
2585         hci_run();
2586         return BLE_PERIPHERAL_OK;
2587     }
2588 
2589     if (!hci_is_le_connection(conn) ||
2590         conn->state == SEND_CREATE_CONNECTION ||
2591         conn->state == SENT_CREATE_CONNECTION) {
2592         hci_emit_le_connection_complete(conn, ERROR_CODE_COMMAND_DISALLOWED);
2593         log_error("le_central_connect: classic connection or connect is already being created");
2594         return BLE_PERIPHERAL_IN_WRONG_STATE;
2595     }
2596 
2597     log_info("le_central_connect: context exists with state %u", conn->state);
2598     hci_emit_le_connection_complete(conn, 0);
2599     hci_run();
2600     return BLE_PERIPHERAL_OK;
2601 }
2602 
2603 // @assumption: only a single outgoing LE Connection exists
2604 static hci_connection_t * le_central_get_outgoing_connection(){
2605     linked_item_t *it;
2606     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2607         hci_connection_t * conn = (hci_connection_t *) it;
2608         if (!hci_is_le_connection(conn)) continue;
2609         switch (conn->state){
2610             case SEND_CREATE_CONNECTION:
2611             case SENT_CREATE_CONNECTION:
2612                 return conn;
2613             default:
2614                 break;
2615         };
2616     }
2617     return NULL;
2618 }
2619 
2620 le_command_status_t le_central_connect_cancel(){
2621     hci_connection_t * conn = le_central_get_outgoing_connection();
2622     switch (conn->state){
2623         case SEND_CREATE_CONNECTION:
2624             // skip sending create connection and emit event instead
2625             hci_emit_le_connection_complete(conn, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2626             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2627             btstack_memory_hci_connection_free( conn );
2628             break;
2629         case SENT_CREATE_CONNECTION:
2630             // request to send cancel connection
2631             conn->state = SEND_CANCEL_CONNECTION;
2632             hci_run();
2633             break;
2634         default:
2635             break;
2636     }
2637     return BLE_PERIPHERAL_OK;
2638 }
2639 
2640 /**
2641  * @brief Updates the connection parameters for a given LE connection
2642  * @param handle
2643  * @param conn_interval_min (unit: 1.25ms)
2644  * @param conn_interval_max (unit: 1.25ms)
2645  * @param conn_latency
2646  * @param supervision_timeout (unit: 10ms)
2647  * @returns 0 if ok
2648  */
2649 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2650     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2651     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2652     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2653     connection->le_conn_interval_min = conn_interval_min;
2654     connection->le_conn_interval_max = conn_interval_max;
2655     connection->le_conn_latency = conn_latency;
2656     connection->le_supervision_timeout = supervision_timeout;
2657     return 0;
2658 }
2659 
2660 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2661     hci_connection_t * conn = hci_connection_for_handle(handle);
2662     if (!conn){
2663         hci_emit_disconnection_complete(handle, 0);
2664         return BLE_PERIPHERAL_OK;
2665     }
2666     conn->state = SEND_DISCONNECT;
2667     hci_run();
2668     return BLE_PERIPHERAL_OK;
2669 }
2670 
2671 void hci_disconnect_all(){
2672     linked_list_iterator_t it;
2673     linked_list_iterator_init(&it, &hci_stack->connections);
2674     while (linked_list_iterator_has_next(&it)){
2675         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2676         if (con->state == SENT_DISCONNECT) continue;
2677         con->state = SEND_DISCONNECT;
2678     }
2679     hci_run();
2680 }
2681