xref: /btstack/src/hci.c (revision 556d11b334d641eaea2ae2d64d2a2b2476a6c29f)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /*
39  *  hci.c
40  *
41  *  Created by Matthias Ringwald on 4/29/09.
42  *
43  */
44 
45 #include "btstack-config.h"
46 
47 #include "hci.h"
48 #include "gap.h"
49 
50 #include <stdarg.h>
51 #include <string.h>
52 #include <stdio.h>
53 
54 #ifndef EMBEDDED
55 #ifdef _WIN32
56 #include "Winsock2.h"
57 #else
58 #include <unistd.h> // gethostbyname
59 #endif
60 #include <btstack/version.h>
61 #endif
62 
63 #include "btstack_memory.h"
64 #include "debug.h"
65 #include "hci_dump.h"
66 
67 #include <btstack/linked_list.h>
68 #include <btstack/hci_cmds.h>
69 
70 #define HCI_CONNECTION_TIMEOUT_MS 10000
71 
72 #ifdef USE_BLUETOOL
73 #include "../platforms/ios/src/bt_control_iphone.h"
74 #endif
75 
76 static void hci_update_scan_enable(void);
77 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
78 static void hci_connection_timeout_handler(timer_source_t *timer);
79 static void hci_connection_timestamp(hci_connection_t *connection);
80 static int  hci_power_control_on(void);
81 static void hci_power_control_off(void);
82 static void hci_state_reset();
83 
84 // the STACK is here
85 #ifndef HAVE_MALLOC
86 static hci_stack_t   hci_stack_static;
87 #endif
88 static hci_stack_t * hci_stack = NULL;
89 
90 // test helper
91 static uint8_t disable_l2cap_timeouts = 0;
92 
93 /**
94  * create connection for given address
95  *
96  * @return connection OR NULL, if no memory left
97  */
98 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
99     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
100     hci_connection_t * conn = btstack_memory_hci_connection_get();
101     if (!conn) return NULL;
102     memset(conn, 0, sizeof(hci_connection_t));
103     BD_ADDR_COPY(conn->address, addr);
104     conn->address_type = addr_type;
105     conn->con_handle = 0xffff;
106     conn->authentication_flags = AUTH_FLAGS_NONE;
107     conn->bonding_flags = 0;
108     conn->requested_security_level = LEVEL_0;
109     linked_item_set_user(&conn->timeout.item, conn);
110     conn->timeout.process = hci_connection_timeout_handler;
111     hci_connection_timestamp(conn);
112     conn->acl_recombination_length = 0;
113     conn->acl_recombination_pos = 0;
114     conn->num_acl_packets_sent = 0;
115     conn->num_sco_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  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
232  */
233 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
234     bd_addr_t addr;
235     bt_flip_addr(addr, bd_addr);
236     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
237     if (conn) {
238         connectionSetAuthenticationFlags(conn, flags);
239         hci_connection_timestamp(conn);
240     }
241 }
242 
243 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
244     hci_connection_t * conn = hci_connection_for_handle(handle);
245     if (!conn) return 0;
246     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
247     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
248     return 0;
249 }
250 
251 void hci_drop_link_key_for_bd_addr(bd_addr_t addr){
252     if (hci_stack->remote_device_db) {
253         hci_stack->remote_device_db->delete_link_key(addr);
254     }
255 }
256 
257 int hci_is_le_connection(hci_connection_t * connection){
258     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
259     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
260 }
261 
262 
263 /**
264  * count connections
265  */
266 static int nr_hci_connections(void){
267     int count = 0;
268     linked_item_t *it;
269     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
270     return count;
271 }
272 
273 /**
274  * Dummy handler called by HCI
275  */
276 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
277 }
278 
279 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
280     hci_connection_t * connection = hci_connection_for_handle(handle);
281     if (!connection) {
282         log_error("hci_number_outgoing_packets: connection for handle %u does not exist!", handle);
283         return 0;
284     }
285     return connection->num_acl_packets_sent;
286 }
287 
288 uint8_t hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
289 
290     int num_packets_sent_classic = 0;
291     int num_packets_sent_le = 0;
292 
293     bd_addr_type_t address_type = BD_ADDR_TYPE_UNKNOWN;
294 
295     linked_item_t *it;
296     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
297         hci_connection_t * connection = (hci_connection_t *) it;
298         if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
299             num_packets_sent_classic += connection->num_acl_packets_sent;
300         } else {
301             num_packets_sent_le += connection->num_acl_packets_sent;
302         }
303         // ignore connections that are not open, e.g., in state RECEIVED_DISCONNECTION_COMPLETE
304         if (connection->con_handle == con_handle && connection->state == OPEN){
305             address_type = connection->address_type;
306         }
307     }
308 
309     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
310     int free_slots_le = 0;
311 
312     if (free_slots_classic < 0){
313         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);
314         return 0;
315     }
316 
317     if (hci_stack->le_acl_packets_total_num){
318         // if we have LE slots, they are used
319         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
320         if (free_slots_le < 0){
321             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);
322             return 0;
323         }
324     } else {
325         // otherwise, classic slots are used for LE, too
326         free_slots_classic -= num_packets_sent_le;
327         if (free_slots_classic < 0){
328             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);
329             return 0;
330         }
331     }
332 
333     switch (address_type){
334         case BD_ADDR_TYPE_UNKNOWN:
335             log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
336             return 0;
337 
338         case BD_ADDR_TYPE_CLASSIC:
339             return free_slots_classic;
340 
341         default:
342            if (hci_stack->le_acl_packets_total_num){
343                return free_slots_le;
344            }
345            return free_slots_classic;
346     }
347 }
348 
349 int hci_number_free_sco_slots_for_handle(hci_con_handle_t handle){
350     int num_sco_packets_sent = 0;
351     linked_item_t *it;
352     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
353         hci_connection_t * connection = (hci_connection_t *) it;
354         num_sco_packets_sent += connection->num_sco_packets_sent;
355     }
356     if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
357         log_info("hci_number_free_sco_slots_for_handle: outgoing packets (%u) > total packets ()", num_sco_packets_sent, hci_stack->sco_packets_total_num);
358         return 0;
359     }
360     return hci_stack->sco_packets_total_num - num_sco_packets_sent;
361 }
362 
363 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
364 int hci_can_send_command_packet_now(void){
365     if (hci_stack->hci_packet_buffer_reserved) return 0;
366 
367     // check for async hci transport implementations
368     if (hci_stack->hci_transport->can_send_packet_now){
369         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
370             return 0;
371         }
372     }
373 
374     return hci_stack->num_cmd_packets > 0;
375 }
376 
377 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
378     // check for async hci transport implementations
379     if (hci_stack->hci_transport->can_send_packet_now){
380         if (!hci_stack->hci_transport->can_send_packet_now(HCI_ACL_DATA_PACKET)){
381             return 0;
382         }
383     }
384     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
385 }
386 
387 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
388     if (hci_stack->hci_packet_buffer_reserved) return 0;
389     return hci_can_send_prepared_acl_packet_now(con_handle);
390 }
391 
392 int hci_can_send_prepared_sco_packet_now(hci_con_handle_t con_handle){
393     if (hci_stack->hci_transport->can_send_packet_now){
394         if (!hci_stack->hci_transport->can_send_packet_now(HCI_SCO_DATA_PACKET)){
395             return 0;
396         }
397     }
398     return hci_number_free_sco_slots_for_handle(con_handle) > 0;
399 }
400 
401 int hci_can_send_sco_packet_now(hci_con_handle_t con_handle){
402     if (hci_stack->hci_packet_buffer_reserved) return 0;
403     return hci_can_send_prepared_sco_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         // notify upper stack that iit might be possible to send again
499         uint8_t event[] = { DAEMON_EVENT_HCI_PACKET_SENT, 0};
500         hci_stack->packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));
501     }
502 
503     return err;
504 }
505 
506 // pre: caller has reserved the packet buffer
507 int hci_send_acl_packet_buffer(int size){
508 
509     // log_info("hci_send_acl_packet_buffer size %u", size);
510 
511     if (!hci_stack->hci_packet_buffer_reserved) {
512         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
513         return 0;
514     }
515 
516     uint8_t * packet = hci_stack->hci_packet_buffer;
517     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
518 
519     // check for free places on Bluetooth module
520     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
521         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
522         hci_release_packet_buffer();
523         return BTSTACK_ACL_BUFFERS_FULL;
524     }
525 
526     hci_connection_t *connection = hci_connection_for_handle( con_handle);
527     if (!connection) {
528         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
529         hci_release_packet_buffer();
530         return 0;
531     }
532     hci_connection_timestamp(connection);
533 
534     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
535 
536     // setup data
537     hci_stack->acl_fragmentation_total_size = size;
538     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
539 
540     return hci_send_acl_packet_fragments(connection);
541 }
542 
543 // pre: caller has reserved the packet buffer
544 int hci_send_sco_packet_buffer(int size){
545 
546     // log_info("hci_send_acl_packet_buffer size %u", size);
547 
548     if (!hci_stack->hci_packet_buffer_reserved) {
549         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
550         return 0;
551     }
552 
553     uint8_t * packet = hci_stack->hci_packet_buffer;
554     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
555 
556     // check for free places on Bluetooth module
557     if (!hci_can_send_prepared_sco_packet_now(con_handle)) {
558         log_error("hci_send_sco_packet_buffer called but no free ACL buffers on controller");
559         hci_release_packet_buffer();
560         return BTSTACK_ACL_BUFFERS_FULL;
561     }
562 
563     // track send packet in connection struct
564     hci_connection_t *connection = hci_connection_for_handle( con_handle);
565     if (!connection) {
566         log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
567         hci_release_packet_buffer();
568         return 0;
569     }
570     connection->num_sco_packets_sent++;
571 
572     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
573     return hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
574 }
575 
576 static void acl_handler(uint8_t *packet, int size){
577 
578     // log_info("acl_handler: size %u", size);
579 
580     // get info
581     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
582     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
583     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
584     uint16_t acl_length         = READ_ACL_LENGTH(packet);
585 
586     // ignore non-registered handle
587     if (!conn){
588         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
589         return;
590     }
591 
592     // assert packet is complete
593     if (acl_length + 4 != size){
594         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
595         return;
596     }
597 
598     // update idle timestamp
599     hci_connection_timestamp(conn);
600 
601     // handle different packet types
602     switch (acl_flags & 0x03) {
603 
604         case 0x01: // continuation fragment
605 
606             // sanity checks
607             if (conn->acl_recombination_pos == 0) {
608                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
609                 return;
610             }
611             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
612                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
613                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
614                 conn->acl_recombination_pos = 0;
615                 return;
616             }
617 
618             // append fragment payload (header already stored)
619             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
620             conn->acl_recombination_pos += acl_length;
621 
622             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
623             //        conn->acl_recombination_pos, conn->acl_recombination_length);
624 
625             // forward complete L2CAP packet if complete.
626             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
627 
628                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, &conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
629                 // reset recombination buffer
630                 conn->acl_recombination_length = 0;
631                 conn->acl_recombination_pos = 0;
632             }
633             break;
634 
635         case 0x02: { // first fragment
636 
637             // sanity check
638             if (conn->acl_recombination_pos) {
639                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
640                 conn->acl_recombination_pos = 0;
641             }
642 
643             // peek into L2CAP packet!
644             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
645 
646             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
647 
648             // compare fragment size to L2CAP packet size
649             if (acl_length >= l2cap_length + 4){
650 
651                 // forward fragment as L2CAP packet
652                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
653 
654             } else {
655 
656                 if (acl_length > HCI_ACL_BUFFER_SIZE){
657                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
658                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
659                     return;
660                 }
661 
662                 // store first fragment and tweak acl length for complete package
663                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
664                 conn->acl_recombination_pos    = acl_length + 4;
665                 conn->acl_recombination_length = l2cap_length;
666                 bt_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
667             }
668             break;
669 
670         }
671         default:
672             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
673             return;
674     }
675 
676     // execute main loop
677     hci_run();
678 }
679 
680 static void hci_shutdown_connection(hci_connection_t *conn){
681     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
682 
683     run_loop_remove_timer(&conn->timeout);
684 
685     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
686     btstack_memory_hci_connection_free( conn );
687 
688     // now it's gone
689     hci_emit_nr_connections_changed();
690 }
691 
692 static const uint16_t packet_type_sizes[] = {
693     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
694     HCI_ACL_DH1_SIZE, 0, 0, 0,
695     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
696     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
697 };
698 static const uint8_t  packet_type_feature_requirement_bit[] = {
699      0, // 3 slot packets
700      1, // 5 slot packets
701     25, // EDR 2 mpbs
702     26, // EDR 3 mbps
703     39, // 3 slot EDR packts
704     40, // 5 slot EDR packet
705 };
706 static const uint16_t packet_type_feature_packet_mask[] = {
707     0x0f00, // 3 slot packets
708     0xf000, // 5 slot packets
709     0x1102, // EDR 2 mpbs
710     0x2204, // EDR 3 mbps
711     0x0300, // 3 slot EDR packts
712     0x3000, // 5 slot EDR packet
713 };
714 
715 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
716     // enable packet types based on size
717     uint16_t packet_types = 0;
718     unsigned int i;
719     for (i=0;i<16;i++){
720         if (packet_type_sizes[i] == 0) continue;
721         if (packet_type_sizes[i] <= buffer_size){
722             packet_types |= 1 << i;
723         }
724     }
725     // disable packet types due to missing local supported features
726     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
727         int bit_idx = packet_type_feature_requirement_bit[i];
728         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
729         if (feature_set) continue;
730         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
731         packet_types &= ~packet_type_feature_packet_mask[i];
732     }
733     // flip bits for "may not be used"
734     packet_types ^= 0x3306;
735     return packet_types;
736 }
737 
738 uint16_t hci_usable_acl_packet_types(void){
739     return hci_stack->packet_types;
740 }
741 
742 uint8_t* hci_get_outgoing_packet_buffer(void){
743     // hci packet buffer is >= acl data packet length
744     return hci_stack->hci_packet_buffer;
745 }
746 
747 uint16_t hci_max_acl_data_packet_length(void){
748     return hci_stack->acl_data_packet_length;
749 }
750 
751 int hci_non_flushable_packet_boundary_flag_supported(void){
752     // No. 54, byte 6, bit 6
753     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
754 }
755 
756 int hci_ssp_supported(void){
757     // No. 51, byte 6, bit 3
758     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
759 }
760 
761 int hci_classic_supported(void){
762     // No. 37, byte 4, bit 5, = No BR/EDR Support
763     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
764 }
765 
766 int hci_le_supported(void){
767 #ifdef HAVE_BLE
768     // No. 37, byte 4, bit 6 = LE Supported (Controller)
769     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
770 #else
771     return 0;
772 #endif
773 }
774 
775 // get addr type and address used in advertisement packets
776 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t  addr){
777     *addr_type = hci_stack->adv_addr_type;
778     if (hci_stack->adv_addr_type){
779         memcpy(addr, hci_stack->adv_address, 6);
780     } else {
781         memcpy(addr, hci_stack->local_bd_addr, 6);
782     }
783 }
784 
785 #ifdef HAVE_BLE
786 void le_handle_advertisement_report(uint8_t *packet, int size){
787     int offset = 3;
788     int num_reports = packet[offset];
789     offset += 1;
790 
791     int i;
792     log_info("HCI: handle adv report with num reports: %d", num_reports);
793     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
794     for (i=0; i<num_reports;i++){
795         uint8_t data_length = packet[offset + 8];
796         uint8_t event_size = 10 + data_length;
797         int pos = 0;
798         event[pos++] = GAP_LE_ADVERTISING_REPORT;
799         event[pos++] = event_size;
800         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
801         offset += 8;
802         pos += 8;
803         event[pos++] = packet[offset + 1 + data_length]; // rssi
804         event[pos++] = packet[offset++]; //data_length;
805         memcpy(&event[pos], &packet[offset], data_length);
806         pos += data_length;
807         offset += data_length + 1; // rssi
808         hci_dump_packet( HCI_EVENT_PACKET, 0, event, pos);
809         hci_stack->packet_handler(HCI_EVENT_PACKET, event, pos);
810     }
811 }
812 #endif
813 
814 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
815     uint8_t command_completed = 0;
816     if ((hci_stack->substate % 2) == 0) return;
817     // odd: waiting for event
818     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
819         uint16_t opcode = READ_BT_16(packet,3);
820         if (opcode == hci_stack->last_cmd_opcode){
821             command_completed = 1;
822             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate >> 1);
823         } else {
824             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
825         }
826     }
827     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
828         uint8_t  status = packet[2];
829         uint16_t opcode = READ_BT_16(packet,4);
830         if (opcode == hci_stack->last_cmd_opcode){
831             if (status){
832                 command_completed = 1;
833                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate >> 1);
834             } else {
835                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
836             }
837         } else {
838             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
839         }
840     }
841 
842     if (!command_completed) return;
843 
844     switch(hci_stack->substate >> 1){
845         default:
846             hci_stack->substate++;
847             break;
848     }
849 }
850 
851 static void hci_initializing_state_machine(){
852     if (hci_stack->substate % 2) {
853         // odd: waiting for command completion
854         return;
855     }
856     // log_info("hci_init: substate %u", hci_stack->substate >> 1);
857     switch (hci_stack->substate >> 1){
858         case 0: // RESET
859             hci_state_reset();
860 
861             hci_send_cmd(&hci_reset);
862             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
863                 // skip baud change
864                 hci_stack->substate = 2 << 1;
865             }
866             break;
867         case 1: // SEND BAUD CHANGE
868             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
869             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
870             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
871             break;
872         case 2: // LOCAL BAUD CHANGE
873             log_info("Local baud rate change");
874             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
875             hci_stack->substate += 2;
876             // break missing here for fall through
877 
878         case 3: // SET BD ADDR
879             if ( hci_stack->custom_bd_addr_set && hci_stack->control && hci_stack->control->set_bd_addr_cmd){
880                 log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
881                 hci_stack->control->set_bd_addr_cmd(hci_stack->config, hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
882                 hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
883                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
884                 break;
885             }
886             hci_stack->substate += 2;
887             // break missing here for fall through
888 
889         case 4:
890             log_info("Custom init");
891             // Custom initialization
892             if (hci_stack->control && hci_stack->control->next_cmd){
893                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
894                 if (valid_cmd){
895                     int size = 3 + hci_stack->hci_packet_buffer[2];
896                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
897                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
898                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
899                     hci_stack->substate = 3 << 1; // more init commands
900                     break;
901                 }
902                 log_info("hci_run: init script done");
903             }
904             // otherwise continue
905             hci_send_cmd(&hci_read_bd_addr);
906             break;
907         case 5:
908             hci_send_cmd(&hci_read_buffer_size);
909             break;
910         case 6:
911             hci_send_cmd(&hci_read_local_supported_features);
912             break;
913         case 7:
914             if (hci_le_supported()){
915                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
916             } else {
917                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
918                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
919             }
920 
921             // skip Classic init commands for LE only chipsets
922             if (!hci_classic_supported()){
923                 if (hci_le_supported()){
924                     hci_stack->substate = 12 << 1;    // skip all classic command
925                 } else {
926                     log_error("Neither BR/EDR nor LE supported");
927                     hci_stack->substate = 15 << 1;    // skip all
928                 }
929             }
930             break;
931         case 8:
932             if (hci_ssp_supported()){
933                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
934                 break;
935             }
936             hci_stack->substate += 2;
937             // break missing here for fall through
938 
939         case 9:
940             // ca. 15 sec
941             hci_send_cmd(&hci_write_page_timeout, 0x6000);
942             break;
943         case 10:
944             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
945             break;
946         case 11:
947             if (hci_stack->local_name){
948                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
949             } else {
950                 char hostname[30];
951 #ifdef EMBEDDED
952                 // BTstack-11:22:33:44:55:66
953                 strcpy(hostname, "BTstack ");
954                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
955                 log_info("---> Name %s", hostname);
956 #else
957                 // hostname for POSIX systems
958                 gethostname(hostname, 30);
959                 hostname[29] = '\0';
960 #endif
961                 hci_send_cmd(&hci_write_local_name, hostname);
962             }
963             break;
964         case 12:
965             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
966             if (!hci_le_supported()){
967                 // SKIP LE init for Classic only configuration
968                 hci_stack->substate = 15 << 1;
969             }
970             break;
971 
972 #ifdef HAVE_BLE
973         // LE INIT
974         case 13:
975             hci_send_cmd(&hci_le_read_buffer_size);
976             break;
977         case 14:
978             // LE Supported Host = 1, Simultaneous Host = 0
979             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
980             break;
981         case 15:
982             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
983             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
984             break;
985 #endif
986 
987         // DONE
988         case 16:
989             // done.
990             hci_stack->state = HCI_STATE_WORKING;
991             hci_emit_state();
992             break;
993         default:
994             break;
995     }
996     hci_stack->substate++;
997 }
998 
999 // avoid huge local variables
1000 #ifndef EMBEDDED
1001 static device_name_t device_name;
1002 #endif
1003 static void event_handler(uint8_t *packet, int size){
1004 
1005     uint16_t event_length = packet[1];
1006 
1007     // assert packet is complete
1008     if (size != event_length + 2){
1009         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
1010         return;
1011     }
1012 
1013     bd_addr_t addr;
1014     bd_addr_type_t addr_type;
1015     uint8_t link_type;
1016     hci_con_handle_t handle;
1017     hci_connection_t * conn;
1018     int i;
1019 
1020     // log_info("HCI:EVENT:%02x", packet[0]);
1021 
1022     switch (packet[0]) {
1023 
1024         case HCI_EVENT_COMMAND_COMPLETE:
1025             // get num cmd packets
1026             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
1027             hci_stack->num_cmd_packets = packet[2];
1028 
1029             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
1030                 // from offset 5
1031                 // status
1032                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
1033                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
1034                 hci_stack->sco_data_packet_length = packet[8];
1035                 hci_stack->acl_packets_total_num  = READ_BT_16(packet, 9);
1036                 hci_stack->sco_packets_total_num  = READ_BT_16(packet, 11);
1037 
1038                 if (hci_stack->state == HCI_STATE_INITIALIZING){
1039                     // determine usable ACL payload size
1040                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
1041                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1042                     }
1043                     log_info("hci_read_buffer_size: acl used size %u, count %u / sco size %u, count %u",
1044                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
1045                              hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
1046                 }
1047             }
1048 #ifdef HAVE_BLE
1049             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
1050                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
1051                 hci_stack->le_acl_packets_total_num  = packet[8];
1052                     // determine usable ACL payload size
1053                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1054                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1055                     }
1056                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1057             }
1058 #endif
1059             // Dump local address
1060             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
1061                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
1062                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1063                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1064             }
1065             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1066                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1067             }
1068             // Note: HCI init checks
1069             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
1070                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1071                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
1072                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
1073                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
1074                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
1075                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
1076 
1077                 // determine usable ACL packet types based on host buffer size and supported features
1078                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1079                 log_info("packet types %04x", hci_stack->packet_types);
1080 
1081                 // Classic/LE
1082                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1083             }
1084             break;
1085 
1086         case HCI_EVENT_COMMAND_STATUS:
1087             // get num cmd packets
1088             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1089             hci_stack->num_cmd_packets = packet[3];
1090             break;
1091 
1092         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1093             int offset = 3;
1094             for (i=0; i<packet[2];i++){
1095                 handle = READ_BT_16(packet, offset);
1096                 offset += 2;
1097                 uint16_t num_packets = READ_BT_16(packet, offset);
1098                 offset += 2;
1099 
1100                 conn = hci_connection_for_handle(handle);
1101                 if (!conn){
1102                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1103                     continue;
1104                 }
1105 
1106                 if (conn->address_type == BD_ADDR_TYPE_SCO){
1107                     if (conn->num_sco_packets_sent >= num_packets){
1108                         conn->num_sco_packets_sent -= num_packets;
1109                     } else {
1110                         log_error("hci_number_completed_packets, more sco slots freed then sent.");
1111                         conn->num_sco_packets_sent = 0;
1112                     }
1113 
1114                 } else {
1115                     if (conn->num_acl_packets_sent >= num_packets){
1116                         conn->num_acl_packets_sent -= num_packets;
1117                     } else {
1118                         log_error("hci_number_completed_packets, more acl slots freed then sent.");
1119                         conn->num_acl_packets_sent = 0;
1120                     }
1121                 }
1122                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1123             }
1124             break;
1125         }
1126         case HCI_EVENT_CONNECTION_REQUEST:
1127             bt_flip_addr(addr, &packet[2]);
1128             // TODO: eval COD 8-10
1129             link_type = packet[11];
1130             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1131             addr_type = link_type == 1 ? BD_ADDR_TYPE_CLASSIC : BD_ADDR_TYPE_SCO;
1132             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1133             if (!conn) {
1134                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1135             }
1136             if (!conn) {
1137                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1138                 hci_stack->decline_reason = 0x0d;
1139                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1140                 break;
1141             }
1142             conn->state = RECEIVED_CONNECTION_REQUEST;
1143             hci_run();
1144             break;
1145 
1146         case HCI_EVENT_CONNECTION_COMPLETE:
1147             // Connection management
1148             bt_flip_addr(addr, &packet[5]);
1149             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1150             addr_type = BD_ADDR_TYPE_CLASSIC;
1151             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1152             if (conn) {
1153                 if (!packet[2]){
1154                     conn->state = OPEN;
1155                     conn->con_handle = READ_BT_16(packet, 3);
1156                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1157 
1158                     // restart timer
1159                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1160                     run_loop_add_timer(&conn->timeout);
1161 
1162                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1163 
1164                     hci_emit_nr_connections_changed();
1165                 } else {
1166                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1167                     uint8_t status = packet[2];
1168                     bd_addr_t bd_address;
1169                     memcpy(&bd_address, conn->address, 6);
1170 
1171                     // connection failed, remove entry
1172                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1173                     btstack_memory_hci_connection_free( conn );
1174 
1175                     // notify client if dedicated bonding
1176                     if (notify_dedicated_bonding_failed){
1177                         log_info("hci notify_dedicated_bonding_failed");
1178                         hci_emit_dedicated_bonding_result(bd_address, status);
1179                     }
1180 
1181                     // if authentication error, also delete link key
1182                     if (packet[2] == 0x05) {
1183                         hci_drop_link_key_for_bd_addr(addr);
1184                     }
1185                 }
1186             }
1187             break;
1188 
1189         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
1190             bt_flip_addr(addr, &packet[5]);
1191             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1192             if (packet[2]){
1193                 // connection failed
1194                 break;
1195             }
1196             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1197             if (!conn) {
1198                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1199             }
1200             if (!conn) {
1201                 break;
1202             }
1203             conn->state = OPEN;
1204             conn->con_handle = READ_BT_16(packet, 3);
1205             break;
1206 
1207         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1208             handle = READ_BT_16(packet, 3);
1209             conn = hci_connection_for_handle(handle);
1210             if (!conn) break;
1211             if (!packet[2]){
1212                 uint8_t * features = &packet[5];
1213                 if (features[6] & (1 << 3)){
1214                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1215                 }
1216             }
1217             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1218             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1219             if (conn->bonding_flags & BONDING_DEDICATED){
1220                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1221             }
1222             break;
1223 
1224         case HCI_EVENT_LINK_KEY_REQUEST:
1225             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1226             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1227             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1228             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1229             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1230             hci_run();
1231             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1232             return;
1233 
1234         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1235             bt_flip_addr(addr, &packet[2]);
1236             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1237             if (!conn) break;
1238             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1239             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1240             // Change Connection Encryption keeps link key type
1241             if (link_key_type != CHANGED_COMBINATION_KEY){
1242                 conn->link_key_type = link_key_type;
1243             }
1244             if (!hci_stack->remote_device_db) break;
1245             hci_stack->remote_device_db->put_link_key(addr, &packet[8], conn->link_key_type);
1246             // still forward event to allow dismiss of pairing dialog
1247             break;
1248         }
1249 
1250         case HCI_EVENT_PIN_CODE_REQUEST:
1251             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1252             // non-bondable mode: pin code negative reply will be sent
1253             if (!hci_stack->bondable){
1254                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1255                 hci_run();
1256                 return;
1257             }
1258             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1259             if (!hci_stack->remote_device_db) break;
1260             bt_flip_addr(addr, &packet[2]);
1261             hci_stack->remote_device_db->delete_link_key(addr);
1262             break;
1263 
1264         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1265             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1266             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1267             break;
1268 
1269         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1270             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1271             if (!hci_stack->ssp_auto_accept) break;
1272             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1273             break;
1274 
1275         case HCI_EVENT_USER_PASSKEY_REQUEST:
1276             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1277             if (!hci_stack->ssp_auto_accept) break;
1278             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1279             break;
1280 
1281         case HCI_EVENT_ENCRYPTION_CHANGE:
1282             handle = READ_BT_16(packet, 3);
1283             conn = hci_connection_for_handle(handle);
1284             if (!conn) break;
1285             if (packet[2] == 0) {
1286                 if (packet[5]){
1287                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1288                 } else {
1289                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1290                 }
1291             }
1292             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1293             break;
1294 
1295         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1296             handle = READ_BT_16(packet, 3);
1297             conn = hci_connection_for_handle(handle);
1298             if (!conn) break;
1299 
1300             // dedicated bonding: send result and disconnect
1301             if (conn->bonding_flags & BONDING_DEDICATED){
1302                 conn->bonding_flags &= ~BONDING_DEDICATED;
1303                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1304                 conn->bonding_status = packet[2];
1305                 break;
1306             }
1307 
1308             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1309                 // link key sufficient for requested security
1310                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1311                 break;
1312             }
1313             // not enough
1314             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1315             break;
1316 
1317 #ifndef EMBEDDED
1318         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1319             if (!hci_stack->remote_device_db) break;
1320             if (packet[2]) break; // status not ok
1321             bt_flip_addr(addr, &packet[3]);
1322             // fix for invalid remote names - terminate on 0xff
1323             for (i=0; i<248;i++){
1324                 if (packet[9+i] == 0xff){
1325                     packet[9+i] = 0;
1326                     break;
1327                 }
1328             }
1329             memset(&device_name, 0, sizeof(device_name_t));
1330             strncpy((char*) device_name, (char*) &packet[9], 248);
1331             hci_stack->remote_device_db->put_name(addr, &device_name);
1332             break;
1333 
1334         case HCI_EVENT_INQUIRY_RESULT:
1335         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1336             if (!hci_stack->remote_device_db) break;
1337             // first send inq result packet
1338             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1339             // then send cached remote names
1340             int offset = 3;
1341             for (i=0; i<packet[2];i++){
1342                 bt_flip_addr(addr, &packet[offset]);
1343                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1344                 if (hci_stack->remote_device_db->get_name(addr, &device_name)){
1345                     hci_emit_remote_name_cached(addr, &device_name);
1346                 }
1347             }
1348             return;
1349         }
1350 #endif
1351 
1352         // HCI_EVENT_DISCONNECTION_COMPLETE
1353         // has been split, to first notify stack before shutting connection down
1354         // see end of function, too.
1355         case HCI_EVENT_DISCONNECTION_COMPLETE:
1356             if (packet[2]) break;   // status != 0
1357             handle = READ_BT_16(packet, 3);
1358             hci_connection_t * conn = hci_connection_for_handle(handle);
1359             if (!conn) break;       // no conn struct anymore
1360             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1361             break;
1362 
1363         case HCI_EVENT_HARDWARE_ERROR:
1364             if(hci_stack->control && hci_stack->control->hw_error){
1365                 (*hci_stack->control->hw_error)();
1366             } else {
1367                 // if no special requests, just reboot stack
1368                 hci_power_control_off();
1369                 hci_power_control_on();
1370             }
1371             break;
1372 
1373         case DAEMON_EVENT_HCI_PACKET_SENT:
1374             // release packet buffer only for asynchronous transport and if there are not further fragements
1375             if (hci_transport_synchronous()) {
1376                 log_error("Synchronous HCI Transport shouldn't send DAEMON_EVENT_HCI_PACKET_SENT");
1377                 return; // instead of break: to avoid re-entering hci_run()
1378             }
1379             if (hci_stack->acl_fragmentation_total_size) break;
1380             hci_release_packet_buffer();
1381             break;
1382 
1383 #ifdef HAVE_BLE
1384         case HCI_EVENT_LE_META:
1385             switch (packet[2]){
1386                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1387                     log_info("advertising report received");
1388                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1389                     le_handle_advertisement_report(packet, size);
1390                     break;
1391                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1392                     // Connection management
1393                     bt_flip_addr(addr, &packet[8]);
1394                     addr_type = (bd_addr_type_t)packet[7];
1395                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1396                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1397                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1398                     if (packet[3]){
1399                         if (conn){
1400                             // outgoing connection failed, remove entry
1401                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1402                             btstack_memory_hci_connection_free( conn );
1403                         }
1404                         // if authentication error, also delete link key
1405                         if (packet[3] == 0x05) {
1406                             hci_drop_link_key_for_bd_addr(addr);
1407                         }
1408                         break;
1409                     }
1410                     if (!conn){
1411                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1412                     }
1413                     if (!conn){
1414                         // no memory
1415                         break;
1416                     }
1417 
1418                     conn->state = OPEN;
1419                     conn->con_handle = READ_BT_16(packet, 4);
1420 
1421                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1422 
1423                     // restart timer
1424                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1425                     // run_loop_add_timer(&conn->timeout);
1426 
1427                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1428 
1429                     hci_emit_nr_connections_changed();
1430                     break;
1431 
1432             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1433 
1434                 default:
1435                     break;
1436             }
1437             break;
1438 #endif
1439         default:
1440             break;
1441     }
1442 
1443     // handle BT initialization
1444     if (hci_stack->state == HCI_STATE_INITIALIZING){
1445         hci_initializing_event_handler(packet, size);
1446     }
1447 
1448     // help with BT sleep
1449     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1450         && hci_stack->substate == 1
1451         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1452         hci_stack->substate++;
1453     }
1454 
1455     // notify upper stack
1456     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1457 
1458     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1459     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1460         if (!packet[2]){
1461             handle = READ_BT_16(packet, 3);
1462             hci_connection_t * conn = hci_connection_for_handle(handle);
1463             if (conn) {
1464                 uint8_t status = conn->bonding_status;
1465                 uint16_t flags = conn->bonding_flags;
1466                 bd_addr_t bd_address;
1467                 memcpy(&bd_address, conn->address, 6);
1468                 hci_shutdown_connection(conn);
1469                 // connection struct is gone, don't access anymore
1470                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1471                     hci_emit_dedicated_bonding_result(bd_address, status);
1472                 }
1473             }
1474         }
1475     }
1476 
1477 	// execute main loop
1478 	hci_run();
1479 }
1480 
1481 static void sco_handler(uint8_t * packet, uint16_t size){
1482     // not handled yet
1483 }
1484 
1485 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1486     hci_dump_packet(packet_type, 1, packet, size);
1487     switch (packet_type) {
1488         case HCI_EVENT_PACKET:
1489             event_handler(packet, size);
1490             break;
1491         case HCI_ACL_DATA_PACKET:
1492             acl_handler(packet, size);
1493             break;
1494         case HCI_SCO_DATA_PACKET:
1495             sco_handler(packet, size);
1496         default:
1497             break;
1498     }
1499 }
1500 
1501 /** Register HCI packet handlers */
1502 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1503     hci_stack->packet_handler = handler;
1504 }
1505 
1506 static void hci_state_reset(){
1507     // no connections yet
1508     hci_stack->connections = NULL;
1509 
1510     // keep discoverable/connectable as this has been requested by the client(s)
1511     // hci_stack->discoverable = 0;
1512     // hci_stack->connectable = 0;
1513     // hci_stack->bondable = 1;
1514 
1515     // buffer is free
1516     hci_stack->hci_packet_buffer_reserved = 0;
1517 
1518     // no pending cmds
1519     hci_stack->decline_reason = 0;
1520     hci_stack->new_scan_enable_value = 0xff;
1521 
1522     // LE
1523     hci_stack->adv_addr_type = 0;
1524     memset(hci_stack->adv_address, 0, 6);
1525     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1526     hci_stack->le_scan_type = 0xff;
1527     hci_stack->le_connection_parameter_range.le_conn_interval_min = 0x0006;
1528     hci_stack->le_connection_parameter_range.le_conn_interval_max = 0x0C80;
1529     hci_stack->le_connection_parameter_range.le_conn_latency_min = 0x0000;
1530     hci_stack->le_connection_parameter_range.le_conn_latency_max = 0x03E8;
1531     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = 0x000A;
1532     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 0x0C80;
1533 }
1534 
1535 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1536 
1537 #ifdef HAVE_MALLOC
1538     if (!hci_stack) {
1539         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1540     }
1541 #else
1542     hci_stack = &hci_stack_static;
1543 #endif
1544     memset(hci_stack, 0, sizeof(hci_stack_t));
1545 
1546     // reference to use transport layer implementation
1547     hci_stack->hci_transport = transport;
1548 
1549     // references to used control implementation
1550     hci_stack->control = control;
1551 
1552     // reference to used config
1553     hci_stack->config = config;
1554 
1555     // higher level handler
1556     hci_stack->packet_handler = dummy_handler;
1557 
1558     // store and open remote device db
1559     hci_stack->remote_device_db = remote_device_db;
1560     if (hci_stack->remote_device_db) {
1561         hci_stack->remote_device_db->open();
1562     }
1563 
1564     // max acl payload size defined in config.h
1565     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1566 
1567     // register packet handlers with transport
1568     transport->register_packet_handler(&packet_handler);
1569 
1570     hci_stack->state = HCI_STATE_OFF;
1571 
1572     // class of device
1573     hci_stack->class_of_device = 0x007a020c; // Smartphone
1574 
1575     // bondable by default
1576     hci_stack->bondable = 1;
1577 
1578     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1579     hci_stack->ssp_enable = 1;
1580     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1581     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1582     hci_stack->ssp_auto_accept = 1;
1583 
1584     hci_state_reset();
1585 }
1586 
1587 void hci_close(){
1588     // close remote device db
1589     if (hci_stack->remote_device_db) {
1590         hci_stack->remote_device_db->close();
1591     }
1592     while (hci_stack->connections) {
1593         // cancel all l2cap connections
1594         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1595         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1596     }
1597     hci_power_control(HCI_POWER_OFF);
1598 
1599 #ifdef HAVE_MALLOC
1600     free(hci_stack);
1601 #endif
1602     hci_stack = NULL;
1603 }
1604 
1605 void hci_set_class_of_device(uint32_t class_of_device){
1606     hci_stack->class_of_device = class_of_device;
1607 }
1608 
1609 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
1610 void hci_set_bd_addr(bd_addr_t addr){
1611     memcpy(hci_stack->custom_bd_addr, addr, 6);
1612     hci_stack->custom_bd_addr_set = 1;
1613 }
1614 
1615 void hci_disable_l2cap_timeout_check(){
1616     disable_l2cap_timeouts = 1;
1617 }
1618 // State-Module-Driver overview
1619 // state                    module  low-level
1620 // HCI_STATE_OFF             off      close
1621 // HCI_STATE_INITIALIZING,   on       open
1622 // HCI_STATE_WORKING,        on       open
1623 // HCI_STATE_HALTING,        on       open
1624 // HCI_STATE_SLEEPING,    off/sleep   close
1625 // HCI_STATE_FALLING_ASLEEP  on       open
1626 
1627 static int hci_power_control_on(void){
1628 
1629     // power on
1630     int err = 0;
1631     if (hci_stack->control && hci_stack->control->on){
1632         err = (*hci_stack->control->on)(hci_stack->config);
1633     }
1634     if (err){
1635         log_error( "POWER_ON failed");
1636         hci_emit_hci_open_failed();
1637         return err;
1638     }
1639 
1640     // open low-level device
1641     err = hci_stack->hci_transport->open(hci_stack->config);
1642     if (err){
1643         log_error( "HCI_INIT failed, turning Bluetooth off again");
1644         if (hci_stack->control && hci_stack->control->off){
1645             (*hci_stack->control->off)(hci_stack->config);
1646         }
1647         hci_emit_hci_open_failed();
1648         return err;
1649     }
1650     return 0;
1651 }
1652 
1653 static void hci_power_control_off(void){
1654 
1655     log_info("hci_power_control_off");
1656 
1657     // close low-level device
1658     hci_stack->hci_transport->close(hci_stack->config);
1659 
1660     log_info("hci_power_control_off - hci_transport closed");
1661 
1662     // power off
1663     if (hci_stack->control && hci_stack->control->off){
1664         (*hci_stack->control->off)(hci_stack->config);
1665     }
1666 
1667     log_info("hci_power_control_off - control closed");
1668 
1669     hci_stack->state = HCI_STATE_OFF;
1670 }
1671 
1672 static void hci_power_control_sleep(void){
1673 
1674     log_info("hci_power_control_sleep");
1675 
1676 #if 0
1677     // don't close serial port during sleep
1678 
1679     // close low-level device
1680     hci_stack->hci_transport->close(hci_stack->config);
1681 #endif
1682 
1683     // sleep mode
1684     if (hci_stack->control && hci_stack->control->sleep){
1685         (*hci_stack->control->sleep)(hci_stack->config);
1686     }
1687 
1688     hci_stack->state = HCI_STATE_SLEEPING;
1689 }
1690 
1691 static int hci_power_control_wake(void){
1692 
1693     log_info("hci_power_control_wake");
1694 
1695     // wake on
1696     if (hci_stack->control && hci_stack->control->wake){
1697         (*hci_stack->control->wake)(hci_stack->config);
1698     }
1699 
1700 #if 0
1701     // open low-level device
1702     int err = hci_stack->hci_transport->open(hci_stack->config);
1703     if (err){
1704         log_error( "HCI_INIT failed, turning Bluetooth off again");
1705         if (hci_stack->control && hci_stack->control->off){
1706             (*hci_stack->control->off)(hci_stack->config);
1707         }
1708         hci_emit_hci_open_failed();
1709         return err;
1710     }
1711 #endif
1712 
1713     return 0;
1714 }
1715 
1716 static void hci_power_transition_to_initializing(void){
1717     // set up state machine
1718     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1719     hci_stack->hci_packet_buffer_reserved = 0;
1720     hci_stack->state = HCI_STATE_INITIALIZING;
1721     hci_stack->substate = 0;
1722 }
1723 
1724 int hci_power_control(HCI_POWER_MODE power_mode){
1725 
1726     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1727 
1728     int err = 0;
1729     switch (hci_stack->state){
1730 
1731         case HCI_STATE_OFF:
1732             switch (power_mode){
1733                 case HCI_POWER_ON:
1734                     err = hci_power_control_on();
1735                     if (err) {
1736                         log_error("hci_power_control_on() error %u", err);
1737                         return err;
1738                     }
1739                     hci_power_transition_to_initializing();
1740                     break;
1741                 case HCI_POWER_OFF:
1742                     // do nothing
1743                     break;
1744                 case HCI_POWER_SLEEP:
1745                     // do nothing (with SLEEP == OFF)
1746                     break;
1747             }
1748             break;
1749 
1750         case HCI_STATE_INITIALIZING:
1751             switch (power_mode){
1752                 case HCI_POWER_ON:
1753                     // do nothing
1754                     break;
1755                 case HCI_POWER_OFF:
1756                     // no connections yet, just turn it off
1757                     hci_power_control_off();
1758                     break;
1759                 case HCI_POWER_SLEEP:
1760                     // no connections yet, just turn it off
1761                     hci_power_control_sleep();
1762                     break;
1763             }
1764             break;
1765 
1766         case HCI_STATE_WORKING:
1767             switch (power_mode){
1768                 case HCI_POWER_ON:
1769                     // do nothing
1770                     break;
1771                 case HCI_POWER_OFF:
1772                     // see hci_run
1773                     hci_stack->state = HCI_STATE_HALTING;
1774                     break;
1775                 case HCI_POWER_SLEEP:
1776                     // see hci_run
1777                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1778                     hci_stack->substate = 0;
1779                     break;
1780             }
1781             break;
1782 
1783         case HCI_STATE_HALTING:
1784             switch (power_mode){
1785                 case HCI_POWER_ON:
1786                     hci_power_transition_to_initializing();
1787                     break;
1788                 case HCI_POWER_OFF:
1789                     // do nothing
1790                     break;
1791                 case HCI_POWER_SLEEP:
1792                     // see hci_run
1793                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1794                     hci_stack->substate = 0;
1795                     break;
1796             }
1797             break;
1798 
1799         case HCI_STATE_FALLING_ASLEEP:
1800             switch (power_mode){
1801                 case HCI_POWER_ON:
1802 
1803 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1804                     // nothing to do, if H4 supports power management
1805                     if (bt_control_iphone_power_management_enabled()){
1806                         hci_stack->state = HCI_STATE_INITIALIZING;
1807                         hci_stack->substate = HCI_INTI_AFTER_SLEEP;
1808                         break;
1809                     }
1810 #endif
1811                     hci_power_transition_to_initializing();
1812                     break;
1813                 case HCI_POWER_OFF:
1814                     // see hci_run
1815                     hci_stack->state = HCI_STATE_HALTING;
1816                     break;
1817                 case HCI_POWER_SLEEP:
1818                     // do nothing
1819                     break;
1820             }
1821             break;
1822 
1823         case HCI_STATE_SLEEPING:
1824             switch (power_mode){
1825                 case HCI_POWER_ON:
1826 
1827 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1828                     // nothing to do, if H4 supports power management
1829                     if (bt_control_iphone_power_management_enabled()){
1830                         hci_stack->state = HCI_STATE_INITIALIZING;
1831                         hci_stack->substate = HCI_INTI_AFTER_SLEEP;
1832                         hci_update_scan_enable();
1833                         break;
1834                     }
1835 #endif
1836                     err = hci_power_control_wake();
1837                     if (err) return err;
1838                     hci_power_transition_to_initializing();
1839                     break;
1840                 case HCI_POWER_OFF:
1841                     hci_stack->state = HCI_STATE_HALTING;
1842                     break;
1843                 case HCI_POWER_SLEEP:
1844                     // do nothing
1845                     break;
1846             }
1847             break;
1848     }
1849 
1850     // create internal event
1851 	hci_emit_state();
1852 
1853 	// trigger next/first action
1854 	hci_run();
1855 
1856     return 0;
1857 }
1858 
1859 static void hci_update_scan_enable(void){
1860     // 2 = page scan, 1 = inq scan
1861     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1862     hci_run();
1863 }
1864 
1865 void hci_discoverable_control(uint8_t enable){
1866     if (enable) enable = 1; // normalize argument
1867 
1868     if (hci_stack->discoverable == enable){
1869         hci_emit_discoverable_enabled(hci_stack->discoverable);
1870         return;
1871     }
1872 
1873     hci_stack->discoverable = enable;
1874     hci_update_scan_enable();
1875 }
1876 
1877 void hci_connectable_control(uint8_t enable){
1878     if (enable) enable = 1; // normalize argument
1879 
1880     // don't emit event
1881     if (hci_stack->connectable == enable) return;
1882 
1883     hci_stack->connectable = enable;
1884     hci_update_scan_enable();
1885 }
1886 
1887 void hci_local_bd_addr(bd_addr_t address_buffer){
1888     memcpy(address_buffer, hci_stack->local_bd_addr, 6);
1889 }
1890 
1891 void hci_run(){
1892 
1893     hci_connection_t * connection;
1894     linked_item_t * it;
1895 
1896     // send continuation fragments first, as they block the prepared packet buffer
1897     if (hci_stack->acl_fragmentation_total_size > 0) {
1898         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1899         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1900             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1901             if (connection) {
1902                 hci_send_acl_packet_fragments(connection);
1903                 return;
1904             }
1905             // connection gone -> discard further fragments
1906             hci_stack->acl_fragmentation_total_size = 0;
1907             hci_stack->acl_fragmentation_pos = 0;
1908         }
1909     }
1910 
1911     if (!hci_can_send_command_packet_now()) return;
1912 
1913     // global/non-connection oriented commands
1914 
1915     // decline incoming connections
1916     if (hci_stack->decline_reason){
1917         uint8_t reason = hci_stack->decline_reason;
1918         hci_stack->decline_reason = 0;
1919         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1920         return;
1921     }
1922 
1923     // send scan enable
1924     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1925         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1926         hci_stack->new_scan_enable_value = 0xff;
1927         return;
1928     }
1929 
1930 #ifdef HAVE_BLE
1931     // handle le scan
1932     if (hci_stack->state == HCI_STATE_WORKING){
1933         switch(hci_stack->le_scanning_state){
1934             case LE_START_SCAN:
1935                 hci_stack->le_scanning_state = LE_SCANNING;
1936                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1937                 return;
1938 
1939             case LE_STOP_SCAN:
1940                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1941                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1942                 return;
1943             default:
1944                 break;
1945         }
1946         if (hci_stack->le_scan_type != 0xff){
1947             // defaults: active scanning, accept all advertisement packets
1948             int scan_type = hci_stack->le_scan_type;
1949             hci_stack->le_scan_type = 0xff;
1950             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);
1951             return;
1952         }
1953     }
1954 #endif
1955 
1956     // send pending HCI commands
1957     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1958         connection = (hci_connection_t *) it;
1959 
1960         switch(connection->state){
1961             case SEND_CREATE_CONNECTION:
1962                 switch(connection->address_type){
1963                     case BD_ADDR_TYPE_CLASSIC:
1964                         log_info("sending hci_create_connection");
1965                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1966                         break;
1967                     default:
1968 #ifdef HAVE_BLE
1969                         log_info("sending hci_le_create_connection");
1970                         hci_send_cmd(&hci_le_create_connection,
1971                                      0x0060,    // scan interval: 60 ms
1972                                      0x0030,    // scan interval: 30 ms
1973                                      0,         // don't use whitelist
1974                                      connection->address_type, // peer address type
1975                                      connection->address,      // peer bd addr
1976                                      hci_stack->adv_addr_type, // our addr type:
1977                                      0x0008,    // conn interval min
1978                                      0x0018,    // conn interval max
1979                                      0,         // conn latency
1980                                      0x0048,    // supervision timeout
1981                                      0x0001,    // min ce length
1982                                      0x0001     // max ce length
1983                                      );
1984 
1985                         connection->state = SENT_CREATE_CONNECTION;
1986 #endif
1987                         break;
1988                 }
1989                 return;
1990 
1991             case RECEIVED_CONNECTION_REQUEST:
1992                 log_info("sending hci_accept_connection_request");
1993                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1994                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
1995                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1996                 } else {
1997                     // TODO: allows to customize synchronous connection parameters
1998                     hci_send_cmd(&hci_accept_synchronous_connection_command, connection->address, 8000, 8000, 0xFFFF, 0x0060, 0xFF, 0x003F);
1999                 }
2000                 return;
2001 
2002 #ifdef HAVE_BLE
2003             case SEND_CANCEL_CONNECTION:
2004                 connection->state = SENT_CANCEL_CONNECTION;
2005                 hci_send_cmd(&hci_le_create_connection_cancel);
2006                 return;
2007 #endif
2008             case SEND_DISCONNECT:
2009                 connection->state = SENT_DISCONNECT;
2010                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
2011                 return;
2012 
2013             default:
2014                 break;
2015         }
2016 
2017         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
2018             log_info("responding to link key request");
2019             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
2020             link_key_t link_key;
2021             link_key_type_t link_key_type;
2022             if ( hci_stack->remote_device_db
2023               && hci_stack->remote_device_db->get_link_key(connection->address, link_key, &link_key_type)
2024               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
2025                connection->link_key_type = link_key_type;
2026                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
2027             } else {
2028                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
2029             }
2030             return;
2031         }
2032 
2033         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
2034             log_info("denying to pin request");
2035             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
2036             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
2037             return;
2038         }
2039 
2040         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
2041             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
2042             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
2043             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
2044                 // tweak authentication requirements
2045                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
2046                 if (connection->bonding_flags & BONDING_DEDICATED){
2047                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2048                 }
2049                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
2050                     authreq |= 1;
2051                 }
2052                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
2053             } else {
2054                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
2055             }
2056             return;
2057         }
2058 
2059         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
2060             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
2061             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
2062             return;
2063         }
2064 
2065         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
2066             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
2067             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
2068             return;
2069         }
2070 
2071         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
2072             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
2073             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
2074             return;
2075         }
2076 
2077         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
2078             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
2079             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
2080             return;
2081         }
2082         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
2083             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
2084             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
2085             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
2086             return;
2087         }
2088         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
2089             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
2090             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
2091             return;
2092         }
2093         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2094             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2095             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2096             return;
2097         }
2098 
2099 #ifdef HAVE_BLE
2100         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2101             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2102 
2103             uint16_t connection_interval_min = connection->le_conn_interval_min;
2104             connection->le_conn_interval_min = 0;
2105             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2106                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2107                 0x0000, 0xffff);
2108         }
2109 #endif
2110     }
2111 
2112     switch (hci_stack->state){
2113         case HCI_STATE_INITIALIZING:
2114             hci_initializing_state_machine();
2115             break;
2116 
2117         case HCI_STATE_HALTING:
2118 
2119             log_info("HCI_STATE_HALTING");
2120             // close all open connections
2121             connection =  (hci_connection_t *) hci_stack->connections;
2122             if (connection){
2123 
2124                 // send disconnect
2125                 if (!hci_can_send_command_packet_now()) return;
2126 
2127                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2128                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2129 
2130                 // send disconnected event right away - causes higher layer connections to get closed, too.
2131                 hci_shutdown_connection(connection);
2132                 return;
2133             }
2134             log_info("HCI_STATE_HALTING, calling off");
2135 
2136             // switch mode
2137             hci_power_control_off();
2138 
2139             log_info("HCI_STATE_HALTING, emitting state");
2140             hci_emit_state();
2141             log_info("HCI_STATE_HALTING, done");
2142             break;
2143 
2144         case HCI_STATE_FALLING_ASLEEP:
2145             switch(hci_stack->substate) {
2146                 case 0:
2147                     log_info("HCI_STATE_FALLING_ASLEEP");
2148                     // close all open connections
2149                     connection =  (hci_connection_t *) hci_stack->connections;
2150 
2151 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2152                     // don't close connections, if H4 supports power management
2153                     if (bt_control_iphone_power_management_enabled()){
2154                         connection = NULL;
2155                     }
2156 #endif
2157                     if (connection){
2158 
2159                         // send disconnect
2160                         if (!hci_can_send_command_packet_now()) return;
2161 
2162                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2163                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2164 
2165                         // send disconnected event right away - causes higher layer connections to get closed, too.
2166                         hci_shutdown_connection(connection);
2167                         return;
2168                     }
2169 
2170                     if (hci_classic_supported()){
2171                         // disable page and inquiry scan
2172                         if (!hci_can_send_command_packet_now()) return;
2173 
2174                         log_info("HCI_STATE_HALTING, disabling inq scans");
2175                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2176 
2177                         // continue in next sub state
2178                         hci_stack->substate++;
2179                         break;
2180                     }
2181                     // fall through for ble-only chips
2182 
2183                 case 2:
2184                     log_info("HCI_STATE_HALTING, calling sleep");
2185 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2186                     // don't actually go to sleep, if H4 supports power management
2187                     if (bt_control_iphone_power_management_enabled()){
2188                         // SLEEP MODE reached
2189                         hci_stack->state = HCI_STATE_SLEEPING;
2190                         hci_emit_state();
2191                         break;
2192                     }
2193 #endif
2194                     // switch mode
2195                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2196                     hci_emit_state();
2197                     break;
2198 
2199                 default:
2200                     break;
2201             }
2202             break;
2203 
2204         default:
2205             break;
2206     }
2207 }
2208 
2209 int hci_send_cmd_packet(uint8_t *packet, int size){
2210     bd_addr_t addr;
2211     hci_connection_t * conn;
2212     // house-keeping
2213 
2214     // create_connection?
2215     if (IS_COMMAND(packet, hci_create_connection)){
2216         bt_flip_addr(addr, &packet[3]);
2217         log_info("Create_connection to %s", bd_addr_to_str(addr));
2218 
2219         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2220         if (!conn){
2221             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2222             if (!conn){
2223                 // notify client that alloc failed
2224                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2225                 return 0; // don't sent packet to controller
2226             }
2227             conn->state = SEND_CREATE_CONNECTION;
2228         }
2229         log_info("conn state %u", conn->state);
2230         switch (conn->state){
2231             // if connection active exists
2232             case OPEN:
2233                 // and OPEN, emit connection complete command, don't send to controller
2234                 hci_emit_connection_complete(conn, 0);
2235                 return 0;
2236             case SEND_CREATE_CONNECTION:
2237                 // connection created by hci, e.g. dedicated bonding
2238                 break;
2239             default:
2240                 // otherwise, just ignore as it is already in the open process
2241                 return 0;
2242         }
2243         conn->state = SENT_CREATE_CONNECTION;
2244     }
2245     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2246         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2247     }
2248     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2249         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2250     }
2251 
2252     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2253         if (hci_stack->remote_device_db){
2254             bt_flip_addr(addr, &packet[3]);
2255             hci_stack->remote_device_db->delete_link_key(addr);
2256         }
2257     }
2258 
2259     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2260     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2261         bt_flip_addr(addr, &packet[3]);
2262         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2263         if (conn){
2264             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2265         }
2266     }
2267 
2268     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2269     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2270     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2271     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2272         bt_flip_addr(addr, &packet[3]);
2273         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2274         if (conn){
2275             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2276         }
2277     }
2278 
2279 #ifdef HAVE_BLE
2280     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2281         hci_stack->adv_addr_type = packet[8];
2282     }
2283     if (IS_COMMAND(packet, hci_le_set_random_address)){
2284         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2285     }
2286 #endif
2287 
2288     hci_stack->num_cmd_packets--;
2289 
2290     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2291     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2292 
2293     // release packet buffer for synchronous transport implementations
2294     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2295         hci_stack->hci_packet_buffer_reserved = 0;
2296     }
2297 
2298     return err;
2299 }
2300 
2301 // disconnect because of security block
2302 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2303     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2304     if (!connection) return;
2305     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2306 }
2307 
2308 
2309 // Configure Secure Simple Pairing
2310 
2311 // enable will enable SSP during init
2312 void hci_ssp_set_enable(int enable){
2313     hci_stack->ssp_enable = enable;
2314 }
2315 
2316 int hci_local_ssp_activated(){
2317     return hci_ssp_supported() && hci_stack->ssp_enable;
2318 }
2319 
2320 // if set, BTstack will respond to io capability request using authentication requirement
2321 void hci_ssp_set_io_capability(int io_capability){
2322     hci_stack->ssp_io_capability = io_capability;
2323 }
2324 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2325     hci_stack->ssp_authentication_requirement = authentication_requirement;
2326 }
2327 
2328 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2329 void hci_ssp_set_auto_accept(int auto_accept){
2330     hci_stack->ssp_auto_accept = auto_accept;
2331 }
2332 
2333 /**
2334  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2335  */
2336 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2337 
2338     if (!hci_can_send_command_packet_now()){
2339         log_error("hci_send_cmd called but cannot send packet now");
2340         return 0;
2341     }
2342 
2343     // for HCI INITIALIZATION
2344     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2345     hci_stack->last_cmd_opcode = cmd->opcode;
2346 
2347     hci_reserve_packet_buffer();
2348     uint8_t * packet = hci_stack->hci_packet_buffer;
2349 
2350     va_list argptr;
2351     va_start(argptr, cmd);
2352     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2353     va_end(argptr);
2354 
2355     return hci_send_cmd_packet(packet, size);
2356 }
2357 
2358 // Create various non-HCI events.
2359 // TODO: generalize, use table similar to hci_create_command
2360 
2361 void hci_emit_state(){
2362     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2363     uint8_t event[3];
2364     event[0] = BTSTACK_EVENT_STATE;
2365     event[1] = sizeof(event) - 2;
2366     event[2] = hci_stack->state;
2367     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2368     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2369 }
2370 
2371 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2372     uint8_t event[13];
2373     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2374     event[1] = sizeof(event) - 2;
2375     event[2] = status;
2376     bt_store_16(event, 3, conn->con_handle);
2377     bt_flip_addr(&event[5], conn->address);
2378     event[11] = 1; // ACL connection
2379     event[12] = 0; // encryption disabled
2380     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2381     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2382 }
2383 
2384 void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, uint16_t conn_handle, uint8_t status){
2385     uint8_t event[21];
2386     event[0] = HCI_EVENT_LE_META;
2387     event[1] = sizeof(event) - 2;
2388     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2389     event[3] = status;
2390     bt_store_16(event, 4, conn_handle);
2391     event[6] = 0; // TODO: role
2392     event[7] = address_type;
2393     bt_flip_addr(&event[8], address);
2394     bt_store_16(event, 14, 0); // interval
2395     bt_store_16(event, 16, 0); // latency
2396     bt_store_16(event, 18, 0); // supervision timeout
2397     event[20] = 0; // master clock accuracy
2398     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2399     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2400 }
2401 
2402 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2403     uint8_t event[6];
2404     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2405     event[1] = sizeof(event) - 2;
2406     event[2] = 0; // status = OK
2407     bt_store_16(event, 3, handle);
2408     event[5] = reason;
2409     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2410     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2411 }
2412 
2413 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2414     if (disable_l2cap_timeouts) return;
2415     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2416     uint8_t event[4];
2417     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2418     event[1] = sizeof(event) - 2;
2419     bt_store_16(event, 2, conn->con_handle);
2420     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2421     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2422 }
2423 
2424 void hci_emit_nr_connections_changed(){
2425     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2426     uint8_t event[3];
2427     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2428     event[1] = sizeof(event) - 2;
2429     event[2] = nr_hci_connections();
2430     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2431     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2432 }
2433 
2434 void hci_emit_hci_open_failed(){
2435     log_info("BTSTACK_EVENT_POWERON_FAILED");
2436     uint8_t event[2];
2437     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2438     event[1] = sizeof(event) - 2;
2439     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2440     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2441 }
2442 
2443 #ifndef EMBEDDED
2444 void hci_emit_btstack_version() {
2445     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2446     uint8_t event[6];
2447     event[0] = BTSTACK_EVENT_VERSION;
2448     event[1] = sizeof(event) - 2;
2449     event[2] = BTSTACK_MAJOR;
2450     event[3] = BTSTACK_MINOR;
2451     bt_store_16(event, 4, BTSTACK_REVISION);
2452     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2453     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2454 }
2455 #endif
2456 
2457 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2458     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2459     uint8_t event[3];
2460     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2461     event[1] = sizeof(event) - 2;
2462     event[2] = enabled;
2463     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2464     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2465 }
2466 
2467 void hci_emit_remote_name_cached(bd_addr_t addr, device_name_t *name){
2468     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2469     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2470     event[1] = sizeof(event) - 2 - 1;
2471     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2472     bt_flip_addr(&event[3], addr);
2473     memcpy(&event[9], name, 248);
2474 
2475     event[9+248] = 0;   // assert \0 for log_info
2476     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(addr), &event[9]);
2477 
2478     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2479     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2480 }
2481 
2482 void hci_emit_discoverable_enabled(uint8_t enabled){
2483     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2484     uint8_t event[3];
2485     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2486     event[1] = sizeof(event) - 2;
2487     event[2] = enabled;
2488     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2489     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2490 }
2491 
2492 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2493     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2494     uint8_t event[5];
2495     int pos = 0;
2496     event[pos++] = GAP_SECURITY_LEVEL;
2497     event[pos++] = sizeof(event) - 2;
2498     bt_store_16(event, 2, con_handle);
2499     pos += 2;
2500     event[pos++] = level;
2501     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2502     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2503 }
2504 
2505 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2506     log_info("hci_emit_dedicated_bonding_result %u ", status);
2507     uint8_t event[9];
2508     int pos = 0;
2509     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2510     event[pos++] = sizeof(event) - 2;
2511     event[pos++] = status;
2512     bt_flip_addr( &event[pos], address);
2513     pos += 6;
2514     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2515     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2516 }
2517 
2518 // query if remote side supports SSP
2519 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2520     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2521     if (!connection) return 0;
2522     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2523 }
2524 
2525 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2526     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2527 }
2528 
2529 // GAP API
2530 /**
2531  * @bbrief enable/disable bonding. default is enabled
2532  * @praram enabled
2533  */
2534 void gap_set_bondable_mode(int enable){
2535     hci_stack->bondable = enable ? 1 : 0;
2536 }
2537 
2538 /**
2539  * @brief map link keys to security levels
2540  */
2541 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2542     switch (link_key_type){
2543         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2544             return LEVEL_4;
2545         case COMBINATION_KEY:
2546         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2547             return LEVEL_3;
2548         default:
2549             return LEVEL_2;
2550     }
2551 }
2552 
2553 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2554     if (!connection) return LEVEL_0;
2555     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2556     return gap_security_level_for_link_key_type(connection->link_key_type);
2557 }
2558 
2559 
2560 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2561     log_info("gap_mitm_protection_required_for_security_level %u", level);
2562     return level > LEVEL_2;
2563 }
2564 
2565 /**
2566  * @brief get current security level
2567  */
2568 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2569     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2570     if (!connection) return LEVEL_0;
2571     return gap_security_level_for_connection(connection);
2572 }
2573 
2574 /**
2575  * @brief request connection to device to
2576  * @result GAP_AUTHENTICATION_RESULT
2577  */
2578 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2579     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2580     if (!connection){
2581         hci_emit_security_level(con_handle, LEVEL_0);
2582         return;
2583     }
2584     gap_security_level_t current_level = gap_security_level(con_handle);
2585     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2586     if (current_level >= requested_level){
2587         hci_emit_security_level(con_handle, current_level);
2588         return;
2589     }
2590 
2591     connection->requested_security_level = requested_level;
2592 
2593 #if 0
2594     // sending encryption request without a link key results in an error.
2595     // TODO: figure out how to use it properly
2596 
2597     // would enabling ecnryption suffice (>= LEVEL_2)?
2598     if (hci_stack->remote_device_db){
2599         link_key_type_t link_key_type;
2600         link_key_t      link_key;
2601         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2602             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2603                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2604                 return;
2605             }
2606         }
2607     }
2608 #endif
2609 
2610     // try to authenticate connection
2611     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2612     hci_run();
2613 }
2614 
2615 /**
2616  * @brief start dedicated bonding with device. disconnect after bonding
2617  * @param device
2618  * @param request MITM protection
2619  * @result GAP_DEDICATED_BONDING_COMPLETE
2620  */
2621 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2622 
2623     // create connection state machine
2624     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2625 
2626     if (!connection){
2627         return BTSTACK_MEMORY_ALLOC_FAILED;
2628     }
2629 
2630     // delete linkn key
2631     hci_drop_link_key_for_bd_addr(device);
2632 
2633     // configure LEVEL_2/3, dedicated bonding
2634     connection->state = SEND_CREATE_CONNECTION;
2635     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2636     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2637     connection->bonding_flags = BONDING_DEDICATED;
2638 
2639     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2640 
2641     // handle: connnection failure (connection complete != ok)
2642     // handle: authentication failure
2643     // handle: disconnect on done
2644 
2645     hci_run();
2646 
2647     return 0;
2648 }
2649 
2650 void gap_set_local_name(const char * local_name){
2651     hci_stack->local_name = local_name;
2652 }
2653 
2654 le_command_status_t le_central_start_scan(){
2655     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2656     hci_stack->le_scanning_state = LE_START_SCAN;
2657     hci_run();
2658     return BLE_PERIPHERAL_OK;
2659 }
2660 
2661 le_command_status_t le_central_stop_scan(){
2662     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2663     hci_stack->le_scanning_state = LE_STOP_SCAN;
2664     hci_run();
2665     return BLE_PERIPHERAL_OK;
2666 }
2667 
2668 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2669     hci_stack->le_scan_type     = scan_type;
2670     hci_stack->le_scan_interval = scan_interval;
2671     hci_stack->le_scan_window   = scan_window;
2672     hci_run();
2673 }
2674 
2675 le_command_status_t le_central_connect(bd_addr_t  addr, bd_addr_type_t addr_type){
2676     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2677     if (!conn){
2678         log_info("le_central_connect: no connection exists yet, creating context");
2679         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2680         if (!conn){
2681             // notify client that alloc failed
2682             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
2683             log_info("le_central_connect: failed to alloc hci_connection_t");
2684             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2685         }
2686         conn->state = SEND_CREATE_CONNECTION;
2687         log_info("le_central_connect: send create connection next");
2688         hci_run();
2689         return BLE_PERIPHERAL_OK;
2690     }
2691 
2692     if (!hci_is_le_connection(conn) ||
2693         conn->state == SEND_CREATE_CONNECTION ||
2694         conn->state == SENT_CREATE_CONNECTION) {
2695         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
2696         log_error("le_central_connect: classic connection or connect is already being created");
2697         return BLE_PERIPHERAL_IN_WRONG_STATE;
2698     }
2699 
2700     log_info("le_central_connect: context exists with state %u", conn->state);
2701     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
2702     hci_run();
2703     return BLE_PERIPHERAL_OK;
2704 }
2705 
2706 // @assumption: only a single outgoing LE Connection exists
2707 static hci_connection_t * le_central_get_outgoing_connection(){
2708     linked_item_t *it;
2709     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2710         hci_connection_t * conn = (hci_connection_t *) it;
2711         if (!hci_is_le_connection(conn)) continue;
2712         switch (conn->state){
2713             case SEND_CREATE_CONNECTION:
2714             case SENT_CREATE_CONNECTION:
2715                 return conn;
2716             default:
2717                 break;
2718         };
2719     }
2720     return NULL;
2721 }
2722 
2723 le_command_status_t le_central_connect_cancel(){
2724     hci_connection_t * conn = le_central_get_outgoing_connection();
2725     switch (conn->state){
2726         case SEND_CREATE_CONNECTION:
2727             // skip sending create connection and emit event instead
2728             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2729             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2730             btstack_memory_hci_connection_free( conn );
2731             break;
2732         case SENT_CREATE_CONNECTION:
2733             // request to send cancel connection
2734             conn->state = SEND_CANCEL_CONNECTION;
2735             hci_run();
2736             break;
2737         default:
2738             break;
2739     }
2740     return BLE_PERIPHERAL_OK;
2741 }
2742 
2743 /**
2744  * @brief Updates the connection parameters for a given LE connection
2745  * @param handle
2746  * @param conn_interval_min (unit: 1.25ms)
2747  * @param conn_interval_max (unit: 1.25ms)
2748  * @param conn_latency
2749  * @param supervision_timeout (unit: 10ms)
2750  * @returns 0 if ok
2751  */
2752 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2753     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2754     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2755     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2756     connection->le_conn_interval_min = conn_interval_min;
2757     connection->le_conn_interval_max = conn_interval_max;
2758     connection->le_conn_latency = conn_latency;
2759     connection->le_supervision_timeout = supervision_timeout;
2760     return 0;
2761 }
2762 
2763 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2764     hci_connection_t * conn = hci_connection_for_handle(handle);
2765     if (!conn){
2766         hci_emit_disconnection_complete(handle, 0);
2767         return BLE_PERIPHERAL_OK;
2768     }
2769     conn->state = SEND_DISCONNECT;
2770     hci_run();
2771     return BLE_PERIPHERAL_OK;
2772 }
2773 
2774 void hci_disconnect_all(){
2775     linked_list_iterator_t it;
2776     linked_list_iterator_init(&it, &hci_stack->connections);
2777     while (linked_list_iterator_has_next(&it)){
2778         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2779         if (con->state == SENT_DISCONNECT) continue;
2780         con->state = SEND_DISCONNECT;
2781     }
2782     hci_run();
2783 }
2784