xref: /btstack/src/hci.c (revision 55975f88a1db5cecd46df279b877020fc1d01501)
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_next_state(){
815     hci_stack->substate = (hci_init_state_t )( ((int) hci_stack->substate) + 1);
816 }
817 
818 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
819     uint8_t command_completed = 0;
820     if ((hci_stack->substate % 2) == 0) return;
821     // odd: waiting for event
822     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
823         uint16_t opcode = READ_BT_16(packet,3);
824         if (opcode == hci_stack->last_cmd_opcode){
825             command_completed = 1;
826             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate >> 1);
827         } else {
828             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
829         }
830     }
831     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
832         uint8_t  status = packet[2];
833         uint16_t opcode = READ_BT_16(packet,4);
834         if (opcode == hci_stack->last_cmd_opcode){
835             if (status){
836                 command_completed = 1;
837                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate >> 1);
838             } else {
839                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
840             }
841         } else {
842             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
843         }
844     }
845 
846     if (!command_completed) return;
847 
848     switch(hci_stack->substate >> 1){
849         default:
850             hci_initializing_next_state();
851             break;
852     }
853 }
854 
855 static void hci_initializing_state_machine(){
856     if (hci_stack->substate % 2) {
857         // odd: waiting for command completion
858         return;
859     }
860     // log_info("hci_init: substate %u", hci_stack->substate >> 1);
861     switch (hci_stack->substate){
862         case HCI_INIT_SEND_RESET:
863             hci_state_reset();
864 
865             hci_send_cmd(&hci_reset);
866             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
867                 // skip baud change
868                 hci_stack->substate = HCI_INIT_LOCAL_BAUD_CHANGE; // to end up at HCI_INIT_SET_BD_ADDR
869             }
870             break;
871         case HCI_INIT_SEND_BAUD_CHANGE:
872             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
873             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
874             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
875             break;
876         case HCI_INIT_LOCAL_BAUD_CHANGE:
877             log_info("Local baud rate change");
878             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
879             hci_stack->substate = HCI_INIT_SET_BD_ADDR;
880             // break missing here for fall through
881 
882         case HCI_INIT_SET_BD_ADDR:
883             if ( hci_stack->custom_bd_addr_set && hci_stack->control && hci_stack->control->set_bd_addr_cmd){
884                 log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
885                 hci_stack->control->set_bd_addr_cmd(hci_stack->config, hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
886                 hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
887                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
888                 break;
889             }
890             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
891             // break missing here for fall through
892 
893         case HCI_INIT_CUSTOM_INIT:
894             log_info("Custom init");
895             // Custom initialization
896             if (hci_stack->control && hci_stack->control->next_cmd){
897                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
898                 if (valid_cmd){
899                     int size = 3 + hci_stack->hci_packet_buffer[2];
900                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
901                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
902                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
903                     hci_stack->substate = 3 << 1; // more init commands
904                     break;
905                 }
906                 log_info("hci_run: init script done");
907             }
908             // otherwise continue
909             hci_send_cmd(&hci_read_bd_addr);
910             break;
911         case HCI_INIT_READ_BUFFER_SIZE:
912             hci_send_cmd(&hci_read_buffer_size);
913             break;
914         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATUES:
915             hci_send_cmd(&hci_read_local_supported_features);
916             break;
917         case HCI_INIT_SET_EVENT_MASK:
918             if (hci_le_supported()){
919                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
920             } else {
921                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
922                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
923             }
924 
925             // skip Classic init commands for LE only chipsets
926             if (!hci_classic_supported()){
927                 if (hci_le_supported()){
928                     hci_stack->substate = HCI_INIT_WRITE_SCAN_ENABLE; // skip all classic command
929                 } else {
930                     log_error("Neither BR/EDR nor LE supported");
931                     hci_stack->substate = HCI_INIT_LE_SET_SCAN_PARAMETERS;    // skip all
932                 }
933             }
934             break;
935         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
936             if (hci_ssp_supported()){
937                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
938                 break;
939             }
940             hci_stack->substate = HCI_INIT_WRITE_PAGE_TIMEOUT;
941             // break missing here for fall through
942 
943         case HCI_INIT_WRITE_PAGE_TIMEOUT:
944             hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
945             break;
946         case HCI_INIT_WRITE_CLASS_OF_DEVICE:
947             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
948             break;
949 
950         case HCI_INIT_WRITE_LOCAL_NAME:
951             if (hci_stack->local_name){
952                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
953             } else {
954                 char hostname[30];
955 #ifdef EMBEDDED
956                 // BTstack-11:22:33:44:55:66
957                 strcpy(hostname, "BTstack ");
958                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
959                 log_info("---> Name %s", hostname);
960 #else
961                 // hostname for POSIX systems
962                 gethostname(hostname, 30);
963                 hostname[29] = '\0';
964 #endif
965                 hci_send_cmd(&hci_write_local_name, hostname);
966             }
967             break;
968         case HCI_INIT_WRITE_SCAN_ENABLE:
969             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
970             if (!hci_le_supported()){
971                 // SKIP LE init for Classic only configuration
972                 hci_stack->substate = HCI_INIT_LE_SET_SCAN_PARAMETERS;
973             }
974             break;
975 
976 #ifdef HAVE_BLE
977         // LE INIT
978         case HCI_INIT_LE_READ_BUFFER_SIZE:
979             hci_send_cmd(&hci_le_read_buffer_size);
980             break;
981         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
982             // LE Supported Host = 1, Simultaneous Host = 0
983             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
984             break;
985         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
986             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
987             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
988             break;
989 #endif
990 
991         // DONE
992         case HCI_INIT_DONE:
993             // done.
994             hci_stack->state = HCI_STATE_WORKING;
995             hci_emit_state();
996             break;
997         default:
998             break;
999     }
1000     hci_initializing_next_state();
1001 }
1002 
1003 // avoid huge local variables
1004 #ifndef EMBEDDED
1005 static device_name_t device_name;
1006 #endif
1007 static void event_handler(uint8_t *packet, int size){
1008 
1009     uint16_t event_length = packet[1];
1010 
1011     // assert packet is complete
1012     if (size != event_length + 2){
1013         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
1014         return;
1015     }
1016 
1017     bd_addr_t addr;
1018     bd_addr_type_t addr_type;
1019     uint8_t link_type;
1020     hci_con_handle_t handle;
1021     hci_connection_t * conn;
1022     int i;
1023 
1024     // log_info("HCI:EVENT:%02x", packet[0]);
1025 
1026     switch (packet[0]) {
1027 
1028         case HCI_EVENT_COMMAND_COMPLETE:
1029             // get num cmd packets
1030             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
1031             hci_stack->num_cmd_packets = packet[2];
1032 
1033             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
1034                 // from offset 5
1035                 // status
1036                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
1037                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
1038                 hci_stack->sco_data_packet_length = packet[8];
1039                 hci_stack->acl_packets_total_num  = READ_BT_16(packet, 9);
1040                 hci_stack->sco_packets_total_num  = READ_BT_16(packet, 11);
1041 
1042                 if (hci_stack->state == HCI_STATE_INITIALIZING){
1043                     // determine usable ACL payload size
1044                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
1045                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1046                     }
1047                     log_info("hci_read_buffer_size: acl used size %u, count %u / sco size %u, count %u",
1048                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
1049                              hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
1050                 }
1051             }
1052 #ifdef HAVE_BLE
1053             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
1054                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
1055                 hci_stack->le_acl_packets_total_num  = packet[8];
1056                     // determine usable ACL payload size
1057                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1058                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1059                     }
1060                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1061             }
1062 #endif
1063             // Dump local address
1064             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
1065                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
1066                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1067                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1068             }
1069             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1070                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1071             }
1072             // Note: HCI init checks
1073             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
1074                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1075                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
1076                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
1077                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
1078                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
1079                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
1080 
1081                 // determine usable ACL packet types based on host buffer size and supported features
1082                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1083                 log_info("packet types %04x", hci_stack->packet_types);
1084 
1085                 // Classic/LE
1086                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1087             }
1088             break;
1089 
1090         case HCI_EVENT_COMMAND_STATUS:
1091             // get num cmd packets
1092             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1093             hci_stack->num_cmd_packets = packet[3];
1094             break;
1095 
1096         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1097             int offset = 3;
1098             for (i=0; i<packet[2];i++){
1099                 handle = READ_BT_16(packet, offset);
1100                 offset += 2;
1101                 uint16_t num_packets = READ_BT_16(packet, offset);
1102                 offset += 2;
1103 
1104                 conn = hci_connection_for_handle(handle);
1105                 if (!conn){
1106                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1107                     continue;
1108                 }
1109 
1110                 if (conn->address_type == BD_ADDR_TYPE_SCO){
1111                     if (conn->num_sco_packets_sent >= num_packets){
1112                         conn->num_sco_packets_sent -= num_packets;
1113                     } else {
1114                         log_error("hci_number_completed_packets, more sco slots freed then sent.");
1115                         conn->num_sco_packets_sent = 0;
1116                     }
1117 
1118                 } else {
1119                     if (conn->num_acl_packets_sent >= num_packets){
1120                         conn->num_acl_packets_sent -= num_packets;
1121                     } else {
1122                         log_error("hci_number_completed_packets, more acl slots freed then sent.");
1123                         conn->num_acl_packets_sent = 0;
1124                     }
1125                 }
1126                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1127             }
1128             break;
1129         }
1130         case HCI_EVENT_CONNECTION_REQUEST:
1131             bt_flip_addr(addr, &packet[2]);
1132             // TODO: eval COD 8-10
1133             link_type = packet[11];
1134             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1135             addr_type = link_type == 1 ? BD_ADDR_TYPE_CLASSIC : BD_ADDR_TYPE_SCO;
1136             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1137             if (!conn) {
1138                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1139             }
1140             if (!conn) {
1141                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1142                 hci_stack->decline_reason = 0x0d;
1143                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1144                 break;
1145             }
1146             conn->state = RECEIVED_CONNECTION_REQUEST;
1147             hci_run();
1148             break;
1149 
1150         case HCI_EVENT_CONNECTION_COMPLETE:
1151             // Connection management
1152             bt_flip_addr(addr, &packet[5]);
1153             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1154             addr_type = BD_ADDR_TYPE_CLASSIC;
1155             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1156             if (conn) {
1157                 if (!packet[2]){
1158                     conn->state = OPEN;
1159                     conn->con_handle = READ_BT_16(packet, 3);
1160                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1161 
1162                     // restart timer
1163                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1164                     run_loop_add_timer(&conn->timeout);
1165 
1166                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1167 
1168                     hci_emit_nr_connections_changed();
1169                 } else {
1170                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1171                     uint8_t status = packet[2];
1172                     bd_addr_t bd_address;
1173                     memcpy(&bd_address, conn->address, 6);
1174 
1175                     // connection failed, remove entry
1176                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1177                     btstack_memory_hci_connection_free( conn );
1178 
1179                     // notify client if dedicated bonding
1180                     if (notify_dedicated_bonding_failed){
1181                         log_info("hci notify_dedicated_bonding_failed");
1182                         hci_emit_dedicated_bonding_result(bd_address, status);
1183                     }
1184 
1185                     // if authentication error, also delete link key
1186                     if (packet[2] == 0x05) {
1187                         hci_drop_link_key_for_bd_addr(addr);
1188                     }
1189                 }
1190             }
1191             break;
1192 
1193         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
1194             bt_flip_addr(addr, &packet[5]);
1195             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1196             if (packet[2]){
1197                 // connection failed
1198                 break;
1199             }
1200             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1201             if (!conn) {
1202                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1203             }
1204             if (!conn) {
1205                 break;
1206             }
1207             conn->state = OPEN;
1208             conn->con_handle = READ_BT_16(packet, 3);
1209             break;
1210 
1211         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1212             handle = READ_BT_16(packet, 3);
1213             conn = hci_connection_for_handle(handle);
1214             if (!conn) break;
1215             if (!packet[2]){
1216                 uint8_t * features = &packet[5];
1217                 if (features[6] & (1 << 3)){
1218                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1219                 }
1220             }
1221             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1222             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1223             if (conn->bonding_flags & BONDING_DEDICATED){
1224                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1225             }
1226             break;
1227 
1228         case HCI_EVENT_LINK_KEY_REQUEST:
1229             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1230             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1231             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1232             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1233             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1234             hci_run();
1235             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1236             return;
1237 
1238         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1239             bt_flip_addr(addr, &packet[2]);
1240             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1241             if (!conn) break;
1242             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1243             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1244             // Change Connection Encryption keeps link key type
1245             if (link_key_type != CHANGED_COMBINATION_KEY){
1246                 conn->link_key_type = link_key_type;
1247             }
1248             if (!hci_stack->remote_device_db) break;
1249             hci_stack->remote_device_db->put_link_key(addr, &packet[8], conn->link_key_type);
1250             // still forward event to allow dismiss of pairing dialog
1251             break;
1252         }
1253 
1254         case HCI_EVENT_PIN_CODE_REQUEST:
1255             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1256             // non-bondable mode: pin code negative reply will be sent
1257             if (!hci_stack->bondable){
1258                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1259                 hci_run();
1260                 return;
1261             }
1262             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1263             if (!hci_stack->remote_device_db) break;
1264             bt_flip_addr(addr, &packet[2]);
1265             hci_stack->remote_device_db->delete_link_key(addr);
1266             break;
1267 
1268         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1269             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1270             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1271             break;
1272 
1273         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1274             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1275             if (!hci_stack->ssp_auto_accept) break;
1276             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1277             break;
1278 
1279         case HCI_EVENT_USER_PASSKEY_REQUEST:
1280             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1281             if (!hci_stack->ssp_auto_accept) break;
1282             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1283             break;
1284 
1285         case HCI_EVENT_ENCRYPTION_CHANGE:
1286             handle = READ_BT_16(packet, 3);
1287             conn = hci_connection_for_handle(handle);
1288             if (!conn) break;
1289             if (packet[2] == 0) {
1290                 if (packet[5]){
1291                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1292                 } else {
1293                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1294                 }
1295             }
1296             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1297             break;
1298 
1299         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1300             handle = READ_BT_16(packet, 3);
1301             conn = hci_connection_for_handle(handle);
1302             if (!conn) break;
1303 
1304             // dedicated bonding: send result and disconnect
1305             if (conn->bonding_flags & BONDING_DEDICATED){
1306                 conn->bonding_flags &= ~BONDING_DEDICATED;
1307                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1308                 conn->bonding_status = packet[2];
1309                 break;
1310             }
1311 
1312             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1313                 // link key sufficient for requested security
1314                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1315                 break;
1316             }
1317             // not enough
1318             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1319             break;
1320 
1321 #ifndef EMBEDDED
1322         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1323             if (!hci_stack->remote_device_db) break;
1324             if (packet[2]) break; // status not ok
1325             bt_flip_addr(addr, &packet[3]);
1326             // fix for invalid remote names - terminate on 0xff
1327             for (i=0; i<248;i++){
1328                 if (packet[9+i] == 0xff){
1329                     packet[9+i] = 0;
1330                     break;
1331                 }
1332             }
1333             memset(&device_name, 0, sizeof(device_name_t));
1334             strncpy((char*) device_name, (char*) &packet[9], 248);
1335             hci_stack->remote_device_db->put_name(addr, &device_name);
1336             break;
1337 
1338         case HCI_EVENT_INQUIRY_RESULT:
1339         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1340             if (!hci_stack->remote_device_db) break;
1341             // first send inq result packet
1342             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1343             // then send cached remote names
1344             int offset = 3;
1345             for (i=0; i<packet[2];i++){
1346                 bt_flip_addr(addr, &packet[offset]);
1347                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1348                 if (hci_stack->remote_device_db->get_name(addr, &device_name)){
1349                     hci_emit_remote_name_cached(addr, &device_name);
1350                 }
1351             }
1352             return;
1353         }
1354 #endif
1355 
1356         // HCI_EVENT_DISCONNECTION_COMPLETE
1357         // has been split, to first notify stack before shutting connection down
1358         // see end of function, too.
1359         case HCI_EVENT_DISCONNECTION_COMPLETE:
1360             if (packet[2]) break;   // status != 0
1361             handle = READ_BT_16(packet, 3);
1362             hci_connection_t * conn = hci_connection_for_handle(handle);
1363             if (!conn) break;       // no conn struct anymore
1364             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1365             break;
1366 
1367         case HCI_EVENT_HARDWARE_ERROR:
1368             if(hci_stack->control && hci_stack->control->hw_error){
1369                 (*hci_stack->control->hw_error)();
1370             } else {
1371                 // if no special requests, just reboot stack
1372                 hci_power_control_off();
1373                 hci_power_control_on();
1374             }
1375             break;
1376 
1377         case DAEMON_EVENT_HCI_PACKET_SENT:
1378             // release packet buffer only for asynchronous transport and if there are not further fragements
1379             if (hci_transport_synchronous()) {
1380                 log_error("Synchronous HCI Transport shouldn't send DAEMON_EVENT_HCI_PACKET_SENT");
1381                 return; // instead of break: to avoid re-entering hci_run()
1382             }
1383             if (hci_stack->acl_fragmentation_total_size) break;
1384             hci_release_packet_buffer();
1385             break;
1386 
1387 #ifdef HAVE_BLE
1388         case HCI_EVENT_LE_META:
1389             switch (packet[2]){
1390                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1391                     log_info("advertising report received");
1392                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1393                     le_handle_advertisement_report(packet, size);
1394                     break;
1395                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1396                     // Connection management
1397                     bt_flip_addr(addr, &packet[8]);
1398                     addr_type = (bd_addr_type_t)packet[7];
1399                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1400                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1401                     conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
1402                     if (packet[3]){
1403                         if (conn){
1404                             // outgoing connection failed, remove entry
1405                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1406                             btstack_memory_hci_connection_free( conn );
1407                         }
1408                         // if authentication error, also delete link key
1409                         if (packet[3] == 0x05) {
1410                             hci_drop_link_key_for_bd_addr(addr);
1411                         }
1412                         break;
1413                     }
1414                     if (!conn){
1415                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1416                     }
1417                     if (!conn){
1418                         // no memory
1419                         break;
1420                     }
1421 
1422                     conn->state = OPEN;
1423                     conn->con_handle = READ_BT_16(packet, 4);
1424 
1425                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1426 
1427                     // restart timer
1428                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1429                     // run_loop_add_timer(&conn->timeout);
1430 
1431                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1432 
1433                     hci_emit_nr_connections_changed();
1434                     break;
1435 
1436             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1437 
1438                 default:
1439                     break;
1440             }
1441             break;
1442 #endif
1443         default:
1444             break;
1445     }
1446 
1447     // handle BT initialization
1448     if (hci_stack->state == HCI_STATE_INITIALIZING){
1449         hci_initializing_event_handler(packet, size);
1450     }
1451 
1452     // help with BT sleep
1453     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1454         && hci_stack->substate == HCI_INIT_W4_SEND_RESET
1455         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1456         hci_initializing_next_state();
1457     }
1458 
1459     // notify upper stack
1460     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1461 
1462     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1463     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1464         if (!packet[2]){
1465             handle = READ_BT_16(packet, 3);
1466             hci_connection_t * conn = hci_connection_for_handle(handle);
1467             if (conn) {
1468                 uint8_t status = conn->bonding_status;
1469                 uint16_t flags = conn->bonding_flags;
1470                 bd_addr_t bd_address;
1471                 memcpy(&bd_address, conn->address, 6);
1472                 hci_shutdown_connection(conn);
1473                 // connection struct is gone, don't access anymore
1474                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1475                     hci_emit_dedicated_bonding_result(bd_address, status);
1476                 }
1477             }
1478         }
1479     }
1480 
1481 	// execute main loop
1482 	hci_run();
1483 }
1484 
1485 static void sco_handler(uint8_t * packet, uint16_t size){
1486     // not handled yet
1487 }
1488 
1489 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1490     hci_dump_packet(packet_type, 1, packet, size);
1491     switch (packet_type) {
1492         case HCI_EVENT_PACKET:
1493             event_handler(packet, size);
1494             break;
1495         case HCI_ACL_DATA_PACKET:
1496             acl_handler(packet, size);
1497             break;
1498         case HCI_SCO_DATA_PACKET:
1499             sco_handler(packet, size);
1500         default:
1501             break;
1502     }
1503 }
1504 
1505 /** Register HCI packet handlers */
1506 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1507     hci_stack->packet_handler = handler;
1508 }
1509 
1510 static void hci_state_reset(){
1511     // no connections yet
1512     hci_stack->connections = NULL;
1513 
1514     // keep discoverable/connectable as this has been requested by the client(s)
1515     // hci_stack->discoverable = 0;
1516     // hci_stack->connectable = 0;
1517     // hci_stack->bondable = 1;
1518 
1519     // buffer is free
1520     hci_stack->hci_packet_buffer_reserved = 0;
1521 
1522     // no pending cmds
1523     hci_stack->decline_reason = 0;
1524     hci_stack->new_scan_enable_value = 0xff;
1525 
1526     // LE
1527     hci_stack->adv_addr_type = 0;
1528     memset(hci_stack->adv_address, 0, 6);
1529     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1530     hci_stack->le_scan_type = 0xff;
1531     hci_stack->le_connection_parameter_range.le_conn_interval_min = 0x0006;
1532     hci_stack->le_connection_parameter_range.le_conn_interval_max = 0x0C80;
1533     hci_stack->le_connection_parameter_range.le_conn_latency_min = 0x0000;
1534     hci_stack->le_connection_parameter_range.le_conn_latency_max = 0x03E8;
1535     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = 0x000A;
1536     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 0x0C80;
1537 }
1538 
1539 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1540 
1541 #ifdef HAVE_MALLOC
1542     if (!hci_stack) {
1543         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1544     }
1545 #else
1546     hci_stack = &hci_stack_static;
1547 #endif
1548     memset(hci_stack, 0, sizeof(hci_stack_t));
1549 
1550     // reference to use transport layer implementation
1551     hci_stack->hci_transport = transport;
1552 
1553     // references to used control implementation
1554     hci_stack->control = control;
1555 
1556     // reference to used config
1557     hci_stack->config = config;
1558 
1559     // higher level handler
1560     hci_stack->packet_handler = dummy_handler;
1561 
1562     // store and open remote device db
1563     hci_stack->remote_device_db = remote_device_db;
1564     if (hci_stack->remote_device_db) {
1565         hci_stack->remote_device_db->open();
1566     }
1567 
1568     // max acl payload size defined in config.h
1569     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1570 
1571     // register packet handlers with transport
1572     transport->register_packet_handler(&packet_handler);
1573 
1574     hci_stack->state = HCI_STATE_OFF;
1575 
1576     // class of device
1577     hci_stack->class_of_device = 0x007a020c; // Smartphone
1578 
1579     // bondable by default
1580     hci_stack->bondable = 1;
1581 
1582     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1583     hci_stack->ssp_enable = 1;
1584     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1585     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1586     hci_stack->ssp_auto_accept = 1;
1587 
1588     hci_state_reset();
1589 }
1590 
1591 void hci_close(){
1592     // close remote device db
1593     if (hci_stack->remote_device_db) {
1594         hci_stack->remote_device_db->close();
1595     }
1596     while (hci_stack->connections) {
1597         // cancel all l2cap connections
1598         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1599         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1600     }
1601     hci_power_control(HCI_POWER_OFF);
1602 
1603 #ifdef HAVE_MALLOC
1604     free(hci_stack);
1605 #endif
1606     hci_stack = NULL;
1607 }
1608 
1609 void hci_set_class_of_device(uint32_t class_of_device){
1610     hci_stack->class_of_device = class_of_device;
1611 }
1612 
1613 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
1614 void hci_set_bd_addr(bd_addr_t addr){
1615     memcpy(hci_stack->custom_bd_addr, addr, 6);
1616     hci_stack->custom_bd_addr_set = 1;
1617 }
1618 
1619 void hci_disable_l2cap_timeout_check(){
1620     disable_l2cap_timeouts = 1;
1621 }
1622 // State-Module-Driver overview
1623 // state                    module  low-level
1624 // HCI_STATE_OFF             off      close
1625 // HCI_STATE_INITIALIZING,   on       open
1626 // HCI_STATE_WORKING,        on       open
1627 // HCI_STATE_HALTING,        on       open
1628 // HCI_STATE_SLEEPING,    off/sleep   close
1629 // HCI_STATE_FALLING_ASLEEP  on       open
1630 
1631 static int hci_power_control_on(void){
1632 
1633     // power on
1634     int err = 0;
1635     if (hci_stack->control && hci_stack->control->on){
1636         err = (*hci_stack->control->on)(hci_stack->config);
1637     }
1638     if (err){
1639         log_error( "POWER_ON failed");
1640         hci_emit_hci_open_failed();
1641         return err;
1642     }
1643 
1644     // open low-level device
1645     err = hci_stack->hci_transport->open(hci_stack->config);
1646     if (err){
1647         log_error( "HCI_INIT failed, turning Bluetooth off again");
1648         if (hci_stack->control && hci_stack->control->off){
1649             (*hci_stack->control->off)(hci_stack->config);
1650         }
1651         hci_emit_hci_open_failed();
1652         return err;
1653     }
1654     return 0;
1655 }
1656 
1657 static void hci_power_control_off(void){
1658 
1659     log_info("hci_power_control_off");
1660 
1661     // close low-level device
1662     hci_stack->hci_transport->close(hci_stack->config);
1663 
1664     log_info("hci_power_control_off - hci_transport closed");
1665 
1666     // power off
1667     if (hci_stack->control && hci_stack->control->off){
1668         (*hci_stack->control->off)(hci_stack->config);
1669     }
1670 
1671     log_info("hci_power_control_off - control closed");
1672 
1673     hci_stack->state = HCI_STATE_OFF;
1674 }
1675 
1676 static void hci_power_control_sleep(void){
1677 
1678     log_info("hci_power_control_sleep");
1679 
1680 #if 0
1681     // don't close serial port during sleep
1682 
1683     // close low-level device
1684     hci_stack->hci_transport->close(hci_stack->config);
1685 #endif
1686 
1687     // sleep mode
1688     if (hci_stack->control && hci_stack->control->sleep){
1689         (*hci_stack->control->sleep)(hci_stack->config);
1690     }
1691 
1692     hci_stack->state = HCI_STATE_SLEEPING;
1693 }
1694 
1695 static int hci_power_control_wake(void){
1696 
1697     log_info("hci_power_control_wake");
1698 
1699     // wake on
1700     if (hci_stack->control && hci_stack->control->wake){
1701         (*hci_stack->control->wake)(hci_stack->config);
1702     }
1703 
1704 #if 0
1705     // open low-level device
1706     int err = hci_stack->hci_transport->open(hci_stack->config);
1707     if (err){
1708         log_error( "HCI_INIT failed, turning Bluetooth off again");
1709         if (hci_stack->control && hci_stack->control->off){
1710             (*hci_stack->control->off)(hci_stack->config);
1711         }
1712         hci_emit_hci_open_failed();
1713         return err;
1714     }
1715 #endif
1716 
1717     return 0;
1718 }
1719 
1720 static void hci_power_transition_to_initializing(void){
1721     // set up state machine
1722     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1723     hci_stack->hci_packet_buffer_reserved = 0;
1724     hci_stack->state = HCI_STATE_INITIALIZING;
1725     hci_stack->substate = HCI_INIT_SEND_RESET;
1726 }
1727 
1728 int hci_power_control(HCI_POWER_MODE power_mode){
1729 
1730     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1731 
1732     int err = 0;
1733     switch (hci_stack->state){
1734 
1735         case HCI_STATE_OFF:
1736             switch (power_mode){
1737                 case HCI_POWER_ON:
1738                     err = hci_power_control_on();
1739                     if (err) {
1740                         log_error("hci_power_control_on() error %u", err);
1741                         return err;
1742                     }
1743                     hci_power_transition_to_initializing();
1744                     break;
1745                 case HCI_POWER_OFF:
1746                     // do nothing
1747                     break;
1748                 case HCI_POWER_SLEEP:
1749                     // do nothing (with SLEEP == OFF)
1750                     break;
1751             }
1752             break;
1753 
1754         case HCI_STATE_INITIALIZING:
1755             switch (power_mode){
1756                 case HCI_POWER_ON:
1757                     // do nothing
1758                     break;
1759                 case HCI_POWER_OFF:
1760                     // no connections yet, just turn it off
1761                     hci_power_control_off();
1762                     break;
1763                 case HCI_POWER_SLEEP:
1764                     // no connections yet, just turn it off
1765                     hci_power_control_sleep();
1766                     break;
1767             }
1768             break;
1769 
1770         case HCI_STATE_WORKING:
1771             switch (power_mode){
1772                 case HCI_POWER_ON:
1773                     // do nothing
1774                     break;
1775                 case HCI_POWER_OFF:
1776                     // see hci_run
1777                     hci_stack->state = HCI_STATE_HALTING;
1778                     break;
1779                 case HCI_POWER_SLEEP:
1780                     // see hci_run
1781                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1782                     hci_stack->substate = HCI_INIT_SEND_RESET;
1783                     break;
1784             }
1785             break;
1786 
1787         case HCI_STATE_HALTING:
1788             switch (power_mode){
1789                 case HCI_POWER_ON:
1790                     hci_power_transition_to_initializing();
1791                     break;
1792                 case HCI_POWER_OFF:
1793                     // do nothing
1794                     break;
1795                 case HCI_POWER_SLEEP:
1796                     // see hci_run
1797                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1798                     hci_stack->substate = HCI_INIT_SEND_RESET;
1799                     break;
1800             }
1801             break;
1802 
1803         case HCI_STATE_FALLING_ASLEEP:
1804             switch (power_mode){
1805                 case HCI_POWER_ON:
1806 
1807 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1808                     // nothing to do, if H4 supports power management
1809                     if (bt_control_iphone_power_management_enabled()){
1810                         hci_stack->state = HCI_STATE_INITIALIZING;
1811                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
1812                         break;
1813                     }
1814 #endif
1815                     hci_power_transition_to_initializing();
1816                     break;
1817                 case HCI_POWER_OFF:
1818                     // see hci_run
1819                     hci_stack->state = HCI_STATE_HALTING;
1820                     break;
1821                 case HCI_POWER_SLEEP:
1822                     // do nothing
1823                     break;
1824             }
1825             break;
1826 
1827         case HCI_STATE_SLEEPING:
1828             switch (power_mode){
1829                 case HCI_POWER_ON:
1830 
1831 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1832                     // nothing to do, if H4 supports power management
1833                     if (bt_control_iphone_power_management_enabled()){
1834                         hci_stack->state = HCI_STATE_INITIALIZING;
1835                         hci_stack->substate = HCI_INIT_AFTER_SLEEP;
1836                         hci_update_scan_enable();
1837                         break;
1838                     }
1839 #endif
1840                     err = hci_power_control_wake();
1841                     if (err) return err;
1842                     hci_power_transition_to_initializing();
1843                     break;
1844                 case HCI_POWER_OFF:
1845                     hci_stack->state = HCI_STATE_HALTING;
1846                     break;
1847                 case HCI_POWER_SLEEP:
1848                     // do nothing
1849                     break;
1850             }
1851             break;
1852     }
1853 
1854     // create internal event
1855 	hci_emit_state();
1856 
1857 	// trigger next/first action
1858 	hci_run();
1859 
1860     return 0;
1861 }
1862 
1863 static void hci_update_scan_enable(void){
1864     // 2 = page scan, 1 = inq scan
1865     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1866     hci_run();
1867 }
1868 
1869 void hci_discoverable_control(uint8_t enable){
1870     if (enable) enable = 1; // normalize argument
1871 
1872     if (hci_stack->discoverable == enable){
1873         hci_emit_discoverable_enabled(hci_stack->discoverable);
1874         return;
1875     }
1876 
1877     hci_stack->discoverable = enable;
1878     hci_update_scan_enable();
1879 }
1880 
1881 void hci_connectable_control(uint8_t enable){
1882     if (enable) enable = 1; // normalize argument
1883 
1884     // don't emit event
1885     if (hci_stack->connectable == enable) return;
1886 
1887     hci_stack->connectable = enable;
1888     hci_update_scan_enable();
1889 }
1890 
1891 void hci_local_bd_addr(bd_addr_t address_buffer){
1892     memcpy(address_buffer, hci_stack->local_bd_addr, 6);
1893 }
1894 
1895 void hci_run(){
1896 
1897     hci_connection_t * connection;
1898     linked_item_t * it;
1899 
1900     // send continuation fragments first, as they block the prepared packet buffer
1901     if (hci_stack->acl_fragmentation_total_size > 0) {
1902         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1903         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1904             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1905             if (connection) {
1906                 hci_send_acl_packet_fragments(connection);
1907                 return;
1908             }
1909             // connection gone -> discard further fragments
1910             hci_stack->acl_fragmentation_total_size = 0;
1911             hci_stack->acl_fragmentation_pos = 0;
1912         }
1913     }
1914 
1915     if (!hci_can_send_command_packet_now()) return;
1916 
1917     // global/non-connection oriented commands
1918 
1919     // decline incoming connections
1920     if (hci_stack->decline_reason){
1921         uint8_t reason = hci_stack->decline_reason;
1922         hci_stack->decline_reason = 0;
1923         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1924         return;
1925     }
1926 
1927     // send scan enable
1928     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1929         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1930         hci_stack->new_scan_enable_value = 0xff;
1931         return;
1932     }
1933 
1934 #ifdef HAVE_BLE
1935     // handle le scan
1936     if (hci_stack->state == HCI_STATE_WORKING){
1937         switch(hci_stack->le_scanning_state){
1938             case LE_START_SCAN:
1939                 hci_stack->le_scanning_state = LE_SCANNING;
1940                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1941                 return;
1942 
1943             case LE_STOP_SCAN:
1944                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1945                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1946                 return;
1947             default:
1948                 break;
1949         }
1950         if (hci_stack->le_scan_type != 0xff){
1951             // defaults: active scanning, accept all advertisement packets
1952             int scan_type = hci_stack->le_scan_type;
1953             hci_stack->le_scan_type = 0xff;
1954             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);
1955             return;
1956         }
1957     }
1958 #endif
1959 
1960     // send pending HCI commands
1961     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1962         connection = (hci_connection_t *) it;
1963 
1964         switch(connection->state){
1965             case SEND_CREATE_CONNECTION:
1966                 switch(connection->address_type){
1967                     case BD_ADDR_TYPE_CLASSIC:
1968                         log_info("sending hci_create_connection");
1969                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1970                         break;
1971                     default:
1972 #ifdef HAVE_BLE
1973                         log_info("sending hci_le_create_connection");
1974                         hci_send_cmd(&hci_le_create_connection,
1975                                      0x0060,    // scan interval: 60 ms
1976                                      0x0030,    // scan interval: 30 ms
1977                                      0,         // don't use whitelist
1978                                      connection->address_type, // peer address type
1979                                      connection->address,      // peer bd addr
1980                                      hci_stack->adv_addr_type, // our addr type:
1981                                      0x0008,    // conn interval min
1982                                      0x0018,    // conn interval max
1983                                      0,         // conn latency
1984                                      0x0048,    // supervision timeout
1985                                      0x0001,    // min ce length
1986                                      0x0001     // max ce length
1987                                      );
1988 
1989                         connection->state = SENT_CREATE_CONNECTION;
1990 #endif
1991                         break;
1992                 }
1993                 return;
1994 
1995             case RECEIVED_CONNECTION_REQUEST:
1996                 log_info("sending hci_accept_connection_request");
1997                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1998                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
1999                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
2000                 } else {
2001                     // TODO: allows to customize synchronous connection parameters
2002                     hci_send_cmd(&hci_accept_synchronous_connection_command, connection->address, 8000, 8000, 0xFFFF, 0x0060, 0xFF, 0x003F);
2003                 }
2004                 return;
2005 
2006 #ifdef HAVE_BLE
2007             case SEND_CANCEL_CONNECTION:
2008                 connection->state = SENT_CANCEL_CONNECTION;
2009                 hci_send_cmd(&hci_le_create_connection_cancel);
2010                 return;
2011 #endif
2012             case SEND_DISCONNECT:
2013                 connection->state = SENT_DISCONNECT;
2014                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
2015                 return;
2016 
2017             default:
2018                 break;
2019         }
2020 
2021         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
2022             log_info("responding to link key request");
2023             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
2024             link_key_t link_key;
2025             link_key_type_t link_key_type;
2026             if ( hci_stack->remote_device_db
2027               && hci_stack->remote_device_db->get_link_key(connection->address, link_key, &link_key_type)
2028               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
2029                connection->link_key_type = link_key_type;
2030                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
2031             } else {
2032                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
2033             }
2034             return;
2035         }
2036 
2037         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
2038             log_info("denying to pin request");
2039             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
2040             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
2041             return;
2042         }
2043 
2044         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
2045             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
2046             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
2047             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
2048                 // tweak authentication requirements
2049                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
2050                 if (connection->bonding_flags & BONDING_DEDICATED){
2051                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2052                 }
2053                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
2054                     authreq |= 1;
2055                 }
2056                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
2057             } else {
2058                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
2059             }
2060             return;
2061         }
2062 
2063         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
2064             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
2065             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
2066             return;
2067         }
2068 
2069         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
2070             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
2071             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
2072             return;
2073         }
2074 
2075         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
2076             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
2077             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
2078             return;
2079         }
2080 
2081         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
2082             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
2083             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
2084             return;
2085         }
2086         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
2087             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
2088             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
2089             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
2090             return;
2091         }
2092         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
2093             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
2094             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
2095             return;
2096         }
2097         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2098             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2099             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2100             return;
2101         }
2102 
2103 #ifdef HAVE_BLE
2104         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2105             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2106 
2107             uint16_t connection_interval_min = connection->le_conn_interval_min;
2108             connection->le_conn_interval_min = 0;
2109             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2110                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2111                 0x0000, 0xffff);
2112         }
2113 #endif
2114     }
2115 
2116     switch (hci_stack->state){
2117         case HCI_STATE_INITIALIZING:
2118             hci_initializing_state_machine();
2119             break;
2120 
2121         case HCI_STATE_HALTING:
2122 
2123             log_info("HCI_STATE_HALTING");
2124             // close all open connections
2125             connection =  (hci_connection_t *) hci_stack->connections;
2126             if (connection){
2127 
2128                 // send disconnect
2129                 if (!hci_can_send_command_packet_now()) return;
2130 
2131                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2132                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2133 
2134                 // send disconnected event right away - causes higher layer connections to get closed, too.
2135                 hci_shutdown_connection(connection);
2136                 return;
2137             }
2138             log_info("HCI_STATE_HALTING, calling off");
2139 
2140             // switch mode
2141             hci_power_control_off();
2142 
2143             log_info("HCI_STATE_HALTING, emitting state");
2144             hci_emit_state();
2145             log_info("HCI_STATE_HALTING, done");
2146             break;
2147 
2148         case HCI_STATE_FALLING_ASLEEP:
2149             switch(hci_stack->substate) {
2150                 case 0:
2151                     log_info("HCI_STATE_FALLING_ASLEEP");
2152                     // close all open connections
2153                     connection =  (hci_connection_t *) hci_stack->connections;
2154 
2155 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2156                     // don't close connections, if H4 supports power management
2157                     if (bt_control_iphone_power_management_enabled()){
2158                         connection = NULL;
2159                     }
2160 #endif
2161                     if (connection){
2162 
2163                         // send disconnect
2164                         if (!hci_can_send_command_packet_now()) return;
2165 
2166                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2167                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2168 
2169                         // send disconnected event right away - causes higher layer connections to get closed, too.
2170                         hci_shutdown_connection(connection);
2171                         return;
2172                     }
2173 
2174                     if (hci_classic_supported()){
2175                         // disable page and inquiry scan
2176                         if (!hci_can_send_command_packet_now()) return;
2177 
2178                         log_info("HCI_STATE_HALTING, disabling inq scans");
2179                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2180 
2181                         // continue in next sub state
2182                         hci_initializing_next_state();
2183                         break;
2184                     }
2185                     // fall through for ble-only chips
2186 
2187                 case 2:
2188                     log_info("HCI_STATE_HALTING, calling sleep");
2189 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2190                     // don't actually go to sleep, if H4 supports power management
2191                     if (bt_control_iphone_power_management_enabled()){
2192                         // SLEEP MODE reached
2193                         hci_stack->state = HCI_STATE_SLEEPING;
2194                         hci_emit_state();
2195                         break;
2196                     }
2197 #endif
2198                     // switch mode
2199                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2200                     hci_emit_state();
2201                     break;
2202 
2203                 default:
2204                     break;
2205             }
2206             break;
2207 
2208         default:
2209             break;
2210     }
2211 }
2212 
2213 int hci_send_cmd_packet(uint8_t *packet, int size){
2214     bd_addr_t addr;
2215     hci_connection_t * conn;
2216     // house-keeping
2217 
2218     // create_connection?
2219     if (IS_COMMAND(packet, hci_create_connection)){
2220         bt_flip_addr(addr, &packet[3]);
2221         log_info("Create_connection to %s", bd_addr_to_str(addr));
2222 
2223         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2224         if (!conn){
2225             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2226             if (!conn){
2227                 // notify client that alloc failed
2228                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2229                 return 0; // don't sent packet to controller
2230             }
2231             conn->state = SEND_CREATE_CONNECTION;
2232         }
2233         log_info("conn state %u", conn->state);
2234         switch (conn->state){
2235             // if connection active exists
2236             case OPEN:
2237                 // and OPEN, emit connection complete command, don't send to controller
2238                 hci_emit_connection_complete(conn, 0);
2239                 return 0;
2240             case SEND_CREATE_CONNECTION:
2241                 // connection created by hci, e.g. dedicated bonding
2242                 break;
2243             default:
2244                 // otherwise, just ignore as it is already in the open process
2245                 return 0;
2246         }
2247         conn->state = SENT_CREATE_CONNECTION;
2248     }
2249     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2250         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2251     }
2252     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2253         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2254     }
2255 
2256     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2257         if (hci_stack->remote_device_db){
2258             bt_flip_addr(addr, &packet[3]);
2259             hci_stack->remote_device_db->delete_link_key(addr);
2260         }
2261     }
2262 
2263     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2264     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2265         bt_flip_addr(addr, &packet[3]);
2266         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2267         if (conn){
2268             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2269         }
2270     }
2271 
2272     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2273     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2274     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2275     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2276         bt_flip_addr(addr, &packet[3]);
2277         conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2278         if (conn){
2279             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2280         }
2281     }
2282 
2283 #ifdef HAVE_BLE
2284     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2285         hci_stack->adv_addr_type = packet[8];
2286     }
2287     if (IS_COMMAND(packet, hci_le_set_random_address)){
2288         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2289     }
2290 #endif
2291 
2292     hci_stack->num_cmd_packets--;
2293 
2294     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2295     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2296 
2297     // release packet buffer for synchronous transport implementations
2298     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2299         hci_stack->hci_packet_buffer_reserved = 0;
2300     }
2301 
2302     return err;
2303 }
2304 
2305 // disconnect because of security block
2306 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2307     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2308     if (!connection) return;
2309     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2310 }
2311 
2312 
2313 // Configure Secure Simple Pairing
2314 
2315 // enable will enable SSP during init
2316 void hci_ssp_set_enable(int enable){
2317     hci_stack->ssp_enable = enable;
2318 }
2319 
2320 int hci_local_ssp_activated(){
2321     return hci_ssp_supported() && hci_stack->ssp_enable;
2322 }
2323 
2324 // if set, BTstack will respond to io capability request using authentication requirement
2325 void hci_ssp_set_io_capability(int io_capability){
2326     hci_stack->ssp_io_capability = io_capability;
2327 }
2328 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2329     hci_stack->ssp_authentication_requirement = authentication_requirement;
2330 }
2331 
2332 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2333 void hci_ssp_set_auto_accept(int auto_accept){
2334     hci_stack->ssp_auto_accept = auto_accept;
2335 }
2336 
2337 /**
2338  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2339  */
2340 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2341 
2342     if (!hci_can_send_command_packet_now()){
2343         log_error("hci_send_cmd called but cannot send packet now");
2344         return 0;
2345     }
2346 
2347     // for HCI INITIALIZATION
2348     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2349     hci_stack->last_cmd_opcode = cmd->opcode;
2350 
2351     hci_reserve_packet_buffer();
2352     uint8_t * packet = hci_stack->hci_packet_buffer;
2353 
2354     va_list argptr;
2355     va_start(argptr, cmd);
2356     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2357     va_end(argptr);
2358 
2359     return hci_send_cmd_packet(packet, size);
2360 }
2361 
2362 // Create various non-HCI events.
2363 // TODO: generalize, use table similar to hci_create_command
2364 
2365 void hci_emit_state(){
2366     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2367     uint8_t event[3];
2368     event[0] = BTSTACK_EVENT_STATE;
2369     event[1] = sizeof(event) - 2;
2370     event[2] = hci_stack->state;
2371     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2372     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2373 }
2374 
2375 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2376     uint8_t event[13];
2377     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2378     event[1] = sizeof(event) - 2;
2379     event[2] = status;
2380     bt_store_16(event, 3, conn->con_handle);
2381     bt_flip_addr(&event[5], conn->address);
2382     event[11] = 1; // ACL connection
2383     event[12] = 0; // encryption disabled
2384     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2385     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2386 }
2387 
2388 void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t address, uint16_t conn_handle, uint8_t status){
2389     uint8_t event[21];
2390     event[0] = HCI_EVENT_LE_META;
2391     event[1] = sizeof(event) - 2;
2392     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2393     event[3] = status;
2394     bt_store_16(event, 4, conn_handle);
2395     event[6] = 0; // TODO: role
2396     event[7] = address_type;
2397     bt_flip_addr(&event[8], address);
2398     bt_store_16(event, 14, 0); // interval
2399     bt_store_16(event, 16, 0); // latency
2400     bt_store_16(event, 18, 0); // supervision timeout
2401     event[20] = 0; // master clock accuracy
2402     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2403     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2404 }
2405 
2406 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2407     uint8_t event[6];
2408     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2409     event[1] = sizeof(event) - 2;
2410     event[2] = 0; // status = OK
2411     bt_store_16(event, 3, handle);
2412     event[5] = reason;
2413     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2414     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2415 }
2416 
2417 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2418     if (disable_l2cap_timeouts) return;
2419     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2420     uint8_t event[4];
2421     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2422     event[1] = sizeof(event) - 2;
2423     bt_store_16(event, 2, conn->con_handle);
2424     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2425     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2426 }
2427 
2428 void hci_emit_nr_connections_changed(){
2429     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2430     uint8_t event[3];
2431     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2432     event[1] = sizeof(event) - 2;
2433     event[2] = nr_hci_connections();
2434     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2435     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2436 }
2437 
2438 void hci_emit_hci_open_failed(){
2439     log_info("BTSTACK_EVENT_POWERON_FAILED");
2440     uint8_t event[2];
2441     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2442     event[1] = sizeof(event) - 2;
2443     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2444     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2445 }
2446 
2447 #ifndef EMBEDDED
2448 void hci_emit_btstack_version() {
2449     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2450     uint8_t event[6];
2451     event[0] = BTSTACK_EVENT_VERSION;
2452     event[1] = sizeof(event) - 2;
2453     event[2] = BTSTACK_MAJOR;
2454     event[3] = BTSTACK_MINOR;
2455     bt_store_16(event, 4, BTSTACK_REVISION);
2456     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2457     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2458 }
2459 #endif
2460 
2461 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2462     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2463     uint8_t event[3];
2464     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2465     event[1] = sizeof(event) - 2;
2466     event[2] = enabled;
2467     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2468     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2469 }
2470 
2471 void hci_emit_remote_name_cached(bd_addr_t addr, device_name_t *name){
2472     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2473     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2474     event[1] = sizeof(event) - 2 - 1;
2475     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2476     bt_flip_addr(&event[3], addr);
2477     memcpy(&event[9], name, 248);
2478 
2479     event[9+248] = 0;   // assert \0 for log_info
2480     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(addr), &event[9]);
2481 
2482     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2483     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2484 }
2485 
2486 void hci_emit_discoverable_enabled(uint8_t enabled){
2487     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2488     uint8_t event[3];
2489     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2490     event[1] = sizeof(event) - 2;
2491     event[2] = enabled;
2492     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2493     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2494 }
2495 
2496 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2497     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2498     uint8_t event[5];
2499     int pos = 0;
2500     event[pos++] = GAP_SECURITY_LEVEL;
2501     event[pos++] = sizeof(event) - 2;
2502     bt_store_16(event, 2, con_handle);
2503     pos += 2;
2504     event[pos++] = level;
2505     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2506     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2507 }
2508 
2509 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2510     log_info("hci_emit_dedicated_bonding_result %u ", status);
2511     uint8_t event[9];
2512     int pos = 0;
2513     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2514     event[pos++] = sizeof(event) - 2;
2515     event[pos++] = status;
2516     bt_flip_addr( &event[pos], address);
2517     pos += 6;
2518     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2519     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2520 }
2521 
2522 // query if remote side supports SSP
2523 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2524     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2525     if (!connection) return 0;
2526     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2527 }
2528 
2529 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2530     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2531 }
2532 
2533 // GAP API
2534 /**
2535  * @bbrief enable/disable bonding. default is enabled
2536  * @praram enabled
2537  */
2538 void gap_set_bondable_mode(int enable){
2539     hci_stack->bondable = enable ? 1 : 0;
2540 }
2541 
2542 /**
2543  * @brief map link keys to security levels
2544  */
2545 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2546     switch (link_key_type){
2547         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2548             return LEVEL_4;
2549         case COMBINATION_KEY:
2550         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2551             return LEVEL_3;
2552         default:
2553             return LEVEL_2;
2554     }
2555 }
2556 
2557 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2558     if (!connection) return LEVEL_0;
2559     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2560     return gap_security_level_for_link_key_type(connection->link_key_type);
2561 }
2562 
2563 
2564 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2565     log_info("gap_mitm_protection_required_for_security_level %u", level);
2566     return level > LEVEL_2;
2567 }
2568 
2569 /**
2570  * @brief get current security level
2571  */
2572 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2573     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2574     if (!connection) return LEVEL_0;
2575     return gap_security_level_for_connection(connection);
2576 }
2577 
2578 /**
2579  * @brief request connection to device to
2580  * @result GAP_AUTHENTICATION_RESULT
2581  */
2582 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2583     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2584     if (!connection){
2585         hci_emit_security_level(con_handle, LEVEL_0);
2586         return;
2587     }
2588     gap_security_level_t current_level = gap_security_level(con_handle);
2589     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2590     if (current_level >= requested_level){
2591         hci_emit_security_level(con_handle, current_level);
2592         return;
2593     }
2594 
2595     connection->requested_security_level = requested_level;
2596 
2597 #if 0
2598     // sending encryption request without a link key results in an error.
2599     // TODO: figure out how to use it properly
2600 
2601     // would enabling ecnryption suffice (>= LEVEL_2)?
2602     if (hci_stack->remote_device_db){
2603         link_key_type_t link_key_type;
2604         link_key_t      link_key;
2605         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2606             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2607                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2608                 return;
2609             }
2610         }
2611     }
2612 #endif
2613 
2614     // try to authenticate connection
2615     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2616     hci_run();
2617 }
2618 
2619 /**
2620  * @brief start dedicated bonding with device. disconnect after bonding
2621  * @param device
2622  * @param request MITM protection
2623  * @result GAP_DEDICATED_BONDING_COMPLETE
2624  */
2625 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2626 
2627     // create connection state machine
2628     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2629 
2630     if (!connection){
2631         return BTSTACK_MEMORY_ALLOC_FAILED;
2632     }
2633 
2634     // delete linkn key
2635     hci_drop_link_key_for_bd_addr(device);
2636 
2637     // configure LEVEL_2/3, dedicated bonding
2638     connection->state = SEND_CREATE_CONNECTION;
2639     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2640     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2641     connection->bonding_flags = BONDING_DEDICATED;
2642 
2643     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2644 
2645     // handle: connnection failure (connection complete != ok)
2646     // handle: authentication failure
2647     // handle: disconnect on done
2648 
2649     hci_run();
2650 
2651     return 0;
2652 }
2653 
2654 void gap_set_local_name(const char * local_name){
2655     hci_stack->local_name = local_name;
2656 }
2657 
2658 le_command_status_t le_central_start_scan(){
2659     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2660     hci_stack->le_scanning_state = LE_START_SCAN;
2661     hci_run();
2662     return BLE_PERIPHERAL_OK;
2663 }
2664 
2665 le_command_status_t le_central_stop_scan(){
2666     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2667     hci_stack->le_scanning_state = LE_STOP_SCAN;
2668     hci_run();
2669     return BLE_PERIPHERAL_OK;
2670 }
2671 
2672 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2673     hci_stack->le_scan_type     = scan_type;
2674     hci_stack->le_scan_interval = scan_interval;
2675     hci_stack->le_scan_window   = scan_window;
2676     hci_run();
2677 }
2678 
2679 le_command_status_t le_central_connect(bd_addr_t  addr, bd_addr_type_t addr_type){
2680     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2681     if (!conn){
2682         log_info("le_central_connect: no connection exists yet, creating context");
2683         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2684         if (!conn){
2685             // notify client that alloc failed
2686             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
2687             log_info("le_central_connect: failed to alloc hci_connection_t");
2688             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2689         }
2690         conn->state = SEND_CREATE_CONNECTION;
2691         log_info("le_central_connect: send create connection next");
2692         hci_run();
2693         return BLE_PERIPHERAL_OK;
2694     }
2695 
2696     if (!hci_is_le_connection(conn) ||
2697         conn->state == SEND_CREATE_CONNECTION ||
2698         conn->state == SENT_CREATE_CONNECTION) {
2699         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
2700         log_error("le_central_connect: classic connection or connect is already being created");
2701         return BLE_PERIPHERAL_IN_WRONG_STATE;
2702     }
2703 
2704     log_info("le_central_connect: context exists with state %u", conn->state);
2705     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, 0);
2706     hci_run();
2707     return BLE_PERIPHERAL_OK;
2708 }
2709 
2710 // @assumption: only a single outgoing LE Connection exists
2711 static hci_connection_t * le_central_get_outgoing_connection(){
2712     linked_item_t *it;
2713     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2714         hci_connection_t * conn = (hci_connection_t *) it;
2715         if (!hci_is_le_connection(conn)) continue;
2716         switch (conn->state){
2717             case SEND_CREATE_CONNECTION:
2718             case SENT_CREATE_CONNECTION:
2719                 return conn;
2720             default:
2721                 break;
2722         };
2723     }
2724     return NULL;
2725 }
2726 
2727 le_command_status_t le_central_connect_cancel(){
2728     hci_connection_t * conn = le_central_get_outgoing_connection();
2729     switch (conn->state){
2730         case SEND_CREATE_CONNECTION:
2731             // skip sending create connection and emit event instead
2732             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2733             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2734             btstack_memory_hci_connection_free( conn );
2735             break;
2736         case SENT_CREATE_CONNECTION:
2737             // request to send cancel connection
2738             conn->state = SEND_CANCEL_CONNECTION;
2739             hci_run();
2740             break;
2741         default:
2742             break;
2743     }
2744     return BLE_PERIPHERAL_OK;
2745 }
2746 
2747 /**
2748  * @brief Updates the connection parameters for a given LE connection
2749  * @param handle
2750  * @param conn_interval_min (unit: 1.25ms)
2751  * @param conn_interval_max (unit: 1.25ms)
2752  * @param conn_latency
2753  * @param supervision_timeout (unit: 10ms)
2754  * @returns 0 if ok
2755  */
2756 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2757     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2758     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2759     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2760     connection->le_conn_interval_min = conn_interval_min;
2761     connection->le_conn_interval_max = conn_interval_max;
2762     connection->le_conn_latency = conn_latency;
2763     connection->le_supervision_timeout = supervision_timeout;
2764     return 0;
2765 }
2766 
2767 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2768     hci_connection_t * conn = hci_connection_for_handle(handle);
2769     if (!conn){
2770         hci_emit_disconnection_complete(handle, 0);
2771         return BLE_PERIPHERAL_OK;
2772     }
2773     conn->state = SEND_DISCONNECT;
2774     hci_run();
2775     return BLE_PERIPHERAL_OK;
2776 }
2777 
2778 void hci_disconnect_all(){
2779     linked_list_iterator_t it;
2780     linked_list_iterator_init(&it, &hci_stack->connections);
2781     while (linked_list_iterator_has_next(&it)){
2782         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2783         if (con->state == SENT_DISCONNECT) continue;
2784         con->state = SEND_DISCONNECT;
2785     }
2786     hci_run();
2787 }
2788