xref: /btstack/src/hci.c (revision a8b124471dfe21102ceed42648b4103360000c12)
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 #define HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP 11
73 
74 #ifdef USE_BLUETOOL
75 #include "../platforms/ios/src/bt_control_iphone.h"
76 #endif
77 
78 static void hci_update_scan_enable(void);
79 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
80 static void hci_connection_timeout_handler(timer_source_t *timer);
81 static void hci_connection_timestamp(hci_connection_t *connection);
82 static int  hci_power_control_on(void);
83 static void hci_power_control_off(void);
84 static void hci_state_reset();
85 
86 // the STACK is here
87 #ifndef HAVE_MALLOC
88 static hci_stack_t   hci_stack_static;
89 #endif
90 static hci_stack_t * hci_stack = NULL;
91 
92 // test helper
93 static uint8_t disable_l2cap_timeouts = 0;
94 
95 /**
96  * create connection for given address
97  *
98  * @return connection OR NULL, if no memory left
99  */
100 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
101     log_info("create_connection_for_addr %s", bd_addr_to_str(addr));
102     hci_connection_t * conn = btstack_memory_hci_connection_get();
103     if (!conn) return NULL;
104     memset(conn, 0, sizeof(hci_connection_t));
105     BD_ADDR_COPY(conn->address, addr);
106     conn->address_type = addr_type;
107     conn->con_handle = 0xffff;
108     conn->authentication_flags = AUTH_FLAGS_NONE;
109     conn->bonding_flags = 0;
110     conn->requested_security_level = LEVEL_0;
111     linked_item_set_user(&conn->timeout.item, conn);
112     conn->timeout.process = hci_connection_timeout_handler;
113     hci_connection_timestamp(conn);
114     conn->acl_recombination_length = 0;
115     conn->acl_recombination_pos = 0;
116     conn->num_acl_packets_sent = 0;
117     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
118     linked_list_add(&hci_stack->connections, (linked_item_t *) conn);
119     return conn;
120 }
121 
122 
123 /**
124  * get le connection parameter range
125 *
126  * @return le connection parameter range struct
127  */
128 le_connection_parameter_range_t gap_le_get_connection_parameter_range(){
129     return hci_stack->le_connection_parameter_range;
130 }
131 
132 /**
133  * set le connection parameter range
134  *
135  */
136 
137 void gap_le_set_connection_parameter_range(le_connection_parameter_range_t range){
138     hci_stack->le_connection_parameter_range.le_conn_interval_min = range.le_conn_interval_min;
139     hci_stack->le_connection_parameter_range.le_conn_interval_max = range.le_conn_interval_max;
140     hci_stack->le_connection_parameter_range.le_conn_interval_min = range.le_conn_latency_min;
141     hci_stack->le_connection_parameter_range.le_conn_interval_max = range.le_conn_latency_max;
142     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = range.le_supervision_timeout_min;
143     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = range.le_supervision_timeout_max;
144 }
145 
146 /**
147  * get hci connections iterator
148  *
149  * @return hci connections iterator
150  */
151 
152 void hci_connections_get_iterator(linked_list_iterator_t *it){
153     linked_list_iterator_init(it, &hci_stack->connections);
154 }
155 
156 /**
157  * get connection for a given handle
158  *
159  * @return connection OR NULL, if not found
160  */
161 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
162     linked_list_iterator_t it;
163     linked_list_iterator_init(&it, &hci_stack->connections);
164     while (linked_list_iterator_has_next(&it)){
165         hci_connection_t * item = (hci_connection_t *) linked_list_iterator_next(&it);
166         if ( item->con_handle == con_handle ) {
167             return item;
168         }
169     }
170     return NULL;
171 }
172 
173 /**
174  * get connection for given address
175  *
176  * @return connection OR NULL, if not found
177  */
178 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t * addr, bd_addr_type_t addr_type){
179     linked_list_iterator_t it;
180     linked_list_iterator_init(&it, &hci_stack->connections);
181     while (linked_list_iterator_has_next(&it)){
182         hci_connection_t * connection = (hci_connection_t *) linked_list_iterator_next(&it);
183         if (connection->address_type != addr_type)  continue;
184         if (memcmp(addr, connection->address, 6) != 0) continue;
185         return connection;
186     }
187     return NULL;
188 }
189 
190 static void hci_connection_timeout_handler(timer_source_t *timer){
191     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
192 #ifdef HAVE_TIME
193     struct timeval tv;
194     gettimeofday(&tv, NULL);
195     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
196         // connections might be timed out
197         hci_emit_l2cap_check_timeout(connection);
198     }
199 #endif
200 #ifdef HAVE_TICK
201     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
202         // connections might be timed out
203         hci_emit_l2cap_check_timeout(connection);
204     }
205 #endif
206     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
207     run_loop_add_timer(timer);
208 }
209 
210 static void hci_connection_timestamp(hci_connection_t *connection){
211 #ifdef HAVE_TIME
212     gettimeofday(&connection->timestamp, NULL);
213 #endif
214 #ifdef HAVE_TICK
215     connection->timestamp = embedded_get_ticks();
216 #endif
217 }
218 
219 
220 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
221     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
222 }
223 
224 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
225     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
226 }
227 
228 
229 /**
230  * add authentication flags and reset timer
231  * @note: assumes classic connection
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_t *) 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 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
350 int hci_can_send_command_packet_now(void){
351     if (hci_stack->hci_packet_buffer_reserved) return 0;
352 
353     // check for async hci transport implementations
354     if (hci_stack->hci_transport->can_send_packet_now){
355         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
356             return 0;
357         }
358     }
359 
360     return hci_stack->num_cmd_packets > 0;
361 }
362 
363 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
364     // check for async hci transport implementations
365     if (hci_stack->hci_transport->can_send_packet_now){
366         if (!hci_stack->hci_transport->can_send_packet_now(HCI_ACL_DATA_PACKET)){
367             return 0;
368         }
369     }
370     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
371 }
372 
373 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
374     if (hci_stack->hci_packet_buffer_reserved) return 0;
375     return hci_can_send_prepared_acl_packet_now(con_handle);
376 }
377 
378 // used for internal checks in l2cap[-le].c
379 int hci_is_packet_buffer_reserved(void){
380     return hci_stack->hci_packet_buffer_reserved;
381 }
382 
383 // reserves outgoing packet buffer. @returns 1 if successful
384 int hci_reserve_packet_buffer(void){
385     if (hci_stack->hci_packet_buffer_reserved) {
386         log_error("hci_reserve_packet_buffer called but buffer already reserved");
387         return 0;
388     }
389     hci_stack->hci_packet_buffer_reserved = 1;
390     return 1;
391 }
392 
393 void hci_release_packet_buffer(void){
394     hci_stack->hci_packet_buffer_reserved = 0;
395 }
396 
397 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
398 int hci_transport_synchronous(void){
399     return hci_stack->hci_transport->can_send_packet_now == NULL;
400 }
401 
402 uint16_t hci_max_acl_le_data_packet_length(void){
403     return hci_stack->le_data_packets_length > 0 ? hci_stack->le_data_packets_length : hci_stack->acl_data_packet_length;
404 }
405 
406 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
407 
408     // 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);
409 
410     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
411     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
412     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
413         max_acl_data_packet_length = hci_stack->le_data_packets_length;
414     }
415 
416     // testing: reduce buffer to minimum
417     // max_acl_data_packet_length = 52;
418 
419     int err;
420     // multiple packets could be send on a synchronous HCI transport
421     while (1){
422 
423         // get current data
424         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
425         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
426         int more_fragments = 0;
427 
428         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
429         if (current_acl_data_packet_length > max_acl_data_packet_length){
430             more_fragments = 1;
431             current_acl_data_packet_length = max_acl_data_packet_length;
432         }
433 
434         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
435         if (acl_header_pos > 0){
436             uint16_t handle_and_flags = READ_BT_16(hci_stack->hci_packet_buffer, 0);
437             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
438             bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
439         }
440 
441         // update header len
442         bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
443 
444         // count packet
445         connection->num_acl_packets_sent++;
446 
447         // send packet
448         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
449         const int size = current_acl_data_packet_length + 4;
450         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
451         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
452 
453         // done yet?
454         if (!more_fragments) break;
455 
456         // update start of next fragment to send
457         hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
458 
459         // can send more?
460         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
461     }
462 
463     // done
464     hci_stack->acl_fragmentation_pos = 0;
465     hci_stack->acl_fragmentation_total_size = 0;
466 
467     // release buffer now for synchronous transport
468     if (hci_transport_synchronous()){
469         hci_release_packet_buffer();
470     }
471 
472     return err;
473 }
474 
475 // pre: caller has reserved the packet buffer
476 int hci_send_acl_packet_buffer(int size){
477 
478     // log_info("hci_send_acl_packet_buffer size %u", size);
479 
480     if (!hci_stack->hci_packet_buffer_reserved) {
481         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
482         return 0;
483     }
484 
485     uint8_t * packet = hci_stack->hci_packet_buffer;
486     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
487 
488     // check for free places on Bluetooth module
489     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
490         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
491         hci_release_packet_buffer();
492         return BTSTACK_ACL_BUFFERS_FULL;
493     }
494 
495     hci_connection_t *connection = hci_connection_for_handle( con_handle);
496     if (!connection) {
497         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
498         hci_release_packet_buffer();
499         return 0;
500     }
501     hci_connection_timestamp(connection);
502 
503     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
504 
505     // setup data
506     hci_stack->acl_fragmentation_total_size = size;
507     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
508 
509     return hci_send_acl_packet_fragments(connection);
510 }
511 
512 static void acl_handler(uint8_t *packet, int size){
513 
514     // log_info("acl_handler: size %u", size);
515 
516     // get info
517     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
518     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
519     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
520     uint16_t acl_length         = READ_ACL_LENGTH(packet);
521 
522     // ignore non-registered handle
523     if (!conn){
524         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
525         return;
526     }
527 
528     // assert packet is complete
529     if (acl_length + 4 != size){
530         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
531         return;
532     }
533 
534     // update idle timestamp
535     hci_connection_timestamp(conn);
536 
537     // handle different packet types
538     switch (acl_flags & 0x03) {
539 
540         case 0x01: // continuation fragment
541 
542             // sanity checks
543             if (conn->acl_recombination_pos == 0) {
544                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
545                 return;
546             }
547             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
548                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
549                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
550                 conn->acl_recombination_pos = 0;
551                 return;
552             }
553 
554             // append fragment payload (header already stored)
555             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
556             conn->acl_recombination_pos += acl_length;
557 
558             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
559             //        conn->acl_recombination_pos, conn->acl_recombination_length);
560 
561             // forward complete L2CAP packet if complete.
562             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
563 
564                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, &conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
565                 // reset recombination buffer
566                 conn->acl_recombination_length = 0;
567                 conn->acl_recombination_pos = 0;
568             }
569             break;
570 
571         case 0x02: { // first fragment
572 
573             // sanity check
574             if (conn->acl_recombination_pos) {
575                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
576                 conn->acl_recombination_pos = 0;
577             }
578 
579             // peek into L2CAP packet!
580             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
581 
582             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
583 
584             // compare fragment size to L2CAP packet size
585             if (acl_length >= l2cap_length + 4){
586 
587                 // forward fragment as L2CAP packet
588                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
589 
590             } else {
591 
592                 if (acl_length > HCI_ACL_BUFFER_SIZE){
593                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
594                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
595                     return;
596                 }
597 
598                 // store first fragment and tweak acl length for complete package
599                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
600                 conn->acl_recombination_pos    = acl_length + 4;
601                 conn->acl_recombination_length = l2cap_length;
602                 bt_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
603             }
604             break;
605 
606         }
607         default:
608             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
609             return;
610     }
611 
612     // execute main loop
613     hci_run();
614 }
615 
616 static void hci_shutdown_connection(hci_connection_t *conn){
617     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
618 
619     run_loop_remove_timer(&conn->timeout);
620 
621     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
622     btstack_memory_hci_connection_free( conn );
623 
624     // now it's gone
625     hci_emit_nr_connections_changed();
626 }
627 
628 static const uint16_t packet_type_sizes[] = {
629     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
630     HCI_ACL_DH1_SIZE, 0, 0, 0,
631     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
632     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
633 };
634 static const uint8_t  packet_type_feature_requirement_bit[] = {
635      0, // 3 slot packets
636      1, // 5 slot packets
637     25, // EDR 2 mpbs
638     26, // EDR 3 mbps
639     39, // 3 slot EDR packts
640     40, // 5 slot EDR packet
641 };
642 static const uint16_t packet_type_feature_packet_mask[] = {
643     0x0f00, // 3 slot packets
644     0xf000, // 5 slot packets
645     0x1102, // EDR 2 mpbs
646     0x2204, // EDR 3 mbps
647     0x0300, // 3 slot EDR packts
648     0x3000, // 5 slot EDR packet
649 };
650 
651 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
652     // enable packet types based on size
653     uint16_t packet_types = 0;
654     unsigned int i;
655     for (i=0;i<16;i++){
656         if (packet_type_sizes[i] == 0) continue;
657         if (packet_type_sizes[i] <= buffer_size){
658             packet_types |= 1 << i;
659         }
660     }
661     // disable packet types due to missing local supported features
662     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
663         int bit_idx = packet_type_feature_requirement_bit[i];
664         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
665         if (feature_set) continue;
666         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
667         packet_types &= ~packet_type_feature_packet_mask[i];
668     }
669     // flip bits for "may not be used"
670     packet_types ^= 0x3306;
671     return packet_types;
672 }
673 
674 uint16_t hci_usable_acl_packet_types(void){
675     return hci_stack->packet_types;
676 }
677 
678 uint8_t* hci_get_outgoing_packet_buffer(void){
679     // hci packet buffer is >= acl data packet length
680     return hci_stack->hci_packet_buffer;
681 }
682 
683 uint16_t hci_max_acl_data_packet_length(void){
684     return hci_stack->acl_data_packet_length;
685 }
686 
687 int hci_non_flushable_packet_boundary_flag_supported(void){
688     // No. 54, byte 6, bit 6
689     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
690 }
691 
692 int hci_ssp_supported(void){
693     // No. 51, byte 6, bit 3
694     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
695 }
696 
697 int hci_classic_supported(void){
698     // No. 37, byte 4, bit 5, = No BR/EDR Support
699     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
700 }
701 
702 int hci_le_supported(void){
703 #ifdef HAVE_BLE
704     // No. 37, byte 4, bit 6 = LE Supported (Controller)
705     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
706 #else
707     return 0;
708 #endif
709 }
710 
711 // get addr type and address used in advertisement packets
712 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
713     *addr_type = hci_stack->adv_addr_type;
714     if (hci_stack->adv_addr_type){
715         memcpy(addr, hci_stack->adv_address, 6);
716     } else {
717         memcpy(addr, hci_stack->local_bd_addr, 6);
718     }
719 }
720 
721 #ifdef HAVE_BLE
722 void le_handle_advertisement_report(uint8_t *packet, int size){
723     int offset = 3;
724     int num_reports = packet[offset];
725     offset += 1;
726 
727     int i;
728     log_info("HCI: handle adv report with num reports: %d", num_reports);
729     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
730     for (i=0; i<num_reports;i++){
731         uint8_t data_length = packet[offset + 8];
732         uint8_t event_size = 10 + data_length;
733         int pos = 0;
734         event[pos++] = GAP_LE_ADVERTISING_REPORT;
735         event[pos++] = event_size;
736         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
737         offset += 8;
738         pos += 8;
739         event[pos++] = packet[offset + 1 + data_length]; // rssi
740         event[pos++] = packet[offset++]; //data_length;
741         memcpy(&event[pos], &packet[offset], data_length);
742         pos += data_length;
743         offset += data_length + 1; // rssi
744         hci_dump_packet( HCI_EVENT_PACKET, 0, event, pos);
745         hci_stack->packet_handler(HCI_EVENT_PACKET, event, pos);
746     }
747 }
748 #endif
749 
750 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
751     uint8_t command_completed = 0;
752     if ((hci_stack->substate % 2) == 0) return;
753     // odd: waiting for event
754     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
755         uint16_t opcode = READ_BT_16(packet,3);
756         if (opcode == hci_stack->last_cmd_opcode){
757             command_completed = 1;
758             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate >> 1);
759         } else {
760             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
761         }
762     }
763     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
764         uint8_t  status = packet[2];
765         uint16_t opcode = READ_BT_16(packet,4);
766         if (opcode == hci_stack->last_cmd_opcode){
767             if (status){
768                 command_completed = 1;
769                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate >> 1);
770             } else {
771                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
772             }
773         } else {
774             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
775         }
776     }
777 
778     if (!command_completed) return;
779 
780     switch(hci_stack->substate >> 1){
781         default:
782             hci_stack->substate++;
783             break;
784     }
785 }
786 
787 static void hci_initializing_state_machine(){
788     if (hci_stack->substate % 2) {
789         // odd: waiting for command completion
790         return;
791     }
792     // log_info("hci_init: substate %u", hci_stack->substate >> 1);
793     switch (hci_stack->substate >> 1){
794         case 0: // RESET
795             hci_state_reset();
796 
797             hci_send_cmd(&hci_reset);
798             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
799                 // skip baud change
800                 hci_stack->substate = 2 << 1;
801             }
802             break;
803         case 1: // SEND BAUD CHANGE
804             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
805             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
806             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
807             break;
808         case 2: // LOCAL BAUD CHANGE
809             log_info("Local baud rate change");
810             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
811             hci_stack->substate += 2;
812             // break missing here for fall through
813 
814         case 3: // SET BD ADDR
815             if ( hci_stack->custom_bd_addr_set && hci_stack->control && hci_stack->control->set_bd_addr_cmd){
816                 log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
817                 hci_stack->control->set_bd_addr_cmd(hci_stack->config, hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
818                 hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
819                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
820                 break;
821             }
822             hci_stack->substate += 2;
823             // break missing here for fall through
824 
825         case 4:
826             log_info("Custom init");
827             // Custom initialization
828             if (hci_stack->control && hci_stack->control->next_cmd){
829                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
830                 if (valid_cmd){
831                     int size = 3 + hci_stack->hci_packet_buffer[2];
832                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
833                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
834                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
835                     hci_stack->substate = 3 << 1; // more init commands
836                     break;
837                 }
838                 log_info("hci_run: init script done");
839             }
840             // otherwise continue
841             hci_send_cmd(&hci_read_bd_addr);
842             break;
843         case 5:
844             hci_send_cmd(&hci_read_buffer_size);
845             break;
846         case 6:
847             hci_send_cmd(&hci_read_local_supported_features);
848             break;
849         case 7:
850             if (hci_le_supported()){
851                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
852             } else {
853                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
854                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
855             }
856 
857             // skip Classic init commands for LE only chipsets
858             if (!hci_classic_supported()){
859                 if (hci_le_supported()){
860                     hci_stack->substate = 12 << 1;    // skip all classic command
861                 } else {
862                     log_error("Neither BR/EDR nor LE supported");
863                     hci_stack->substate = 15 << 1;    // skip all
864                 }
865             }
866             break;
867         case 8:
868             if (hci_ssp_supported()){
869                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
870                 break;
871             }
872             hci_stack->substate += 2;
873             // break missing here for fall through
874 
875         case 9:
876             // ca. 15 sec
877             hci_send_cmd(&hci_write_page_timeout, 0x6000);
878             break;
879         case 10:
880             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
881             break;
882         case 11:
883             if (hci_stack->local_name){
884                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
885             } else {
886                 char hostname[30];
887 #ifdef EMBEDDED
888                 // BTstack-11:22:33:44:55:66
889                 strcpy(hostname, "BTstack ");
890                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
891                 log_info("---> Name %s", hostname);
892 #else
893                 // hostname for POSIX systems
894                 gethostname(hostname, 30);
895                 hostname[29] = '\0';
896 #endif
897                 hci_send_cmd(&hci_write_local_name, hostname);
898             }
899             break;
900         case 12:
901             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
902             if (!hci_le_supported()){
903                 // SKIP LE init for Classic only configuration
904                 hci_stack->substate = 15 << 1;
905             }
906             break;
907 
908 #ifdef HAVE_BLE
909         // LE INIT
910         case 13:
911             hci_send_cmd(&hci_le_read_buffer_size);
912             break;
913         case 14:
914             // LE Supported Host = 1, Simultaneous Host = 0
915             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
916             break;
917         case 15:
918             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
919             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
920             break;
921 #endif
922 
923         // DONE
924         case 16:
925             // done.
926             hci_stack->state = HCI_STATE_WORKING;
927             hci_emit_state();
928             break;
929         default:
930             break;
931     }
932     hci_stack->substate++;
933 }
934 
935 // avoid huge local variables
936 #ifndef EMBEDDED
937 static device_name_t device_name;
938 #endif
939 static void event_handler(uint8_t *packet, int size){
940 
941     uint16_t event_length = packet[1];
942 
943     // assert packet is complete
944     if (size != event_length + 2){
945         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
946         return;
947     }
948 
949     bd_addr_t addr;
950     bd_addr_type_t addr_type;
951     uint8_t link_type;
952     hci_con_handle_t handle;
953     hci_connection_t * conn;
954     int i;
955 
956     // log_info("HCI:EVENT:%02x", packet[0]);
957 
958     switch (packet[0]) {
959 
960         case HCI_EVENT_COMMAND_COMPLETE:
961             // get num cmd packets
962             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
963             hci_stack->num_cmd_packets = packet[2];
964 
965             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
966                 // from offset 5
967                 // status
968                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
969                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
970                 hci_stack->sco_data_packet_length = packet[8];
971                 hci_stack->acl_packets_total_num  = packet[9];
972                 hci_stack->sco_packets_total_num  = packet[10];
973 
974                 if (hci_stack->state == HCI_STATE_INITIALIZING){
975                     // determine usable ACL payload size
976                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
977                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
978                     }
979                     log_info("hci_read_buffer_size: used size %u, count %u",
980                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num);
981                 }
982             }
983 #ifdef HAVE_BLE
984             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
985                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
986                 hci_stack->le_acl_packets_total_num  = packet[8];
987                     // determine usable ACL payload size
988                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
989                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
990                     }
991                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
992             }
993 #endif
994             // Dump local address
995             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
996                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
997                 log_info("Local Address, Status: 0x%02x: Addr: %s",
998                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
999             }
1000             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1001                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1002             }
1003             // Note: HCI init checks
1004             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
1005                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1006                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
1007                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
1008                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
1009                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
1010                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
1011 
1012                 // determine usable ACL packet types based on host buffer size and supported features
1013                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1014                 log_info("packet types %04x", hci_stack->packet_types);
1015 
1016                 // Classic/LE
1017                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1018             }
1019             break;
1020 
1021         case HCI_EVENT_COMMAND_STATUS:
1022             // get num cmd packets
1023             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1024             hci_stack->num_cmd_packets = packet[3];
1025             break;
1026 
1027         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1028             int offset = 3;
1029             for (i=0; i<packet[2];i++){
1030                 handle = READ_BT_16(packet, offset);
1031                 offset += 2;
1032                 uint16_t num_packets = READ_BT_16(packet, offset);
1033                 offset += 2;
1034 
1035                 conn = hci_connection_for_handle(handle);
1036                 if (!conn){
1037                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1038                     continue;
1039                 }
1040 
1041                 if (conn->num_acl_packets_sent >= num_packets){
1042                     conn->num_acl_packets_sent -= num_packets;
1043                 } else {
1044                     log_error("hci_number_completed_packets, more slots freed then sent.");
1045                     conn->num_acl_packets_sent = 0;
1046                 }
1047                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1048             }
1049             break;
1050         }
1051         case HCI_EVENT_CONNECTION_REQUEST:
1052             bt_flip_addr(addr, &packet[2]);
1053             // TODO: eval COD 8-10
1054             link_type = packet[11];
1055             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1056             if (link_type == 1) { // ACL
1057                 conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1058                 if (!conn) {
1059                     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1060                 }
1061                 if (!conn) {
1062                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1063                     hci_stack->decline_reason = 0x0d;
1064                     BD_ADDR_COPY(hci_stack->decline_addr, addr);
1065                     break;
1066                 }
1067                 conn->state = RECEIVED_CONNECTION_REQUEST;
1068                 hci_run();
1069             } else {
1070                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
1071                 hci_stack->decline_reason = 0x0a;
1072                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1073             }
1074             break;
1075 
1076         case HCI_EVENT_CONNECTION_COMPLETE:
1077             // Connection management
1078             bt_flip_addr(addr, &packet[5]);
1079             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1080             addr_type = BD_ADDR_TYPE_CLASSIC;
1081             conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1082             if (conn) {
1083                 if (!packet[2]){
1084                     conn->state = OPEN;
1085                     conn->con_handle = READ_BT_16(packet, 3);
1086                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1087 
1088                     // restart timer
1089                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1090                     run_loop_add_timer(&conn->timeout);
1091 
1092                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1093 
1094                     hci_emit_nr_connections_changed();
1095                 } else {
1096                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1097                     uint8_t status = packet[2];
1098                     bd_addr_t bd_address;
1099                     memcpy(&bd_address, conn->address, 6);
1100 
1101                     // connection failed, remove entry
1102                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1103                     btstack_memory_hci_connection_free( conn );
1104 
1105                     // notify client if dedicated bonding
1106                     if (notify_dedicated_bonding_failed){
1107                         log_info("hci notify_dedicated_bonding_failed");
1108                         hci_emit_dedicated_bonding_result(bd_address, status);
1109                     }
1110 
1111                     // if authentication error, also delete link key
1112                     if (packet[2] == 0x05) {
1113                         hci_drop_link_key_for_bd_addr(&addr);
1114                     }
1115                 }
1116             }
1117             break;
1118 
1119         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1120             handle = READ_BT_16(packet, 3);
1121             conn = hci_connection_for_handle(handle);
1122             if (!conn) break;
1123             if (!packet[2]){
1124                 uint8_t * features = &packet[5];
1125                 if (features[6] & (1 << 3)){
1126                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1127                 }
1128             }
1129             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1130             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1131             if (conn->bonding_flags & BONDING_DEDICATED){
1132                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1133             }
1134             break;
1135 
1136         case HCI_EVENT_LINK_KEY_REQUEST:
1137             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1138             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1139             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1140             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1141             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1142             hci_run();
1143             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1144             return;
1145 
1146         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1147             bt_flip_addr(addr, &packet[2]);
1148             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1149             if (!conn) break;
1150             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1151             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1152             // Change Connection Encryption keeps link key type
1153             if (link_key_type != CHANGED_COMBINATION_KEY){
1154                 conn->link_key_type = link_key_type;
1155             }
1156             if (!hci_stack->remote_device_db) break;
1157             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
1158             // still forward event to allow dismiss of pairing dialog
1159             break;
1160         }
1161 
1162         case HCI_EVENT_PIN_CODE_REQUEST:
1163             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1164             // non-bondable mode: pin code negative reply will be sent
1165             if (!hci_stack->bondable){
1166                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1167                 hci_run();
1168                 return;
1169             }
1170             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1171             if (!hci_stack->remote_device_db) break;
1172             bt_flip_addr(addr, &packet[2]);
1173             hci_stack->remote_device_db->delete_link_key(&addr);
1174             break;
1175 
1176         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1177             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1178             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1179             break;
1180 
1181         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1182             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1183             if (!hci_stack->ssp_auto_accept) break;
1184             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1185             break;
1186 
1187         case HCI_EVENT_USER_PASSKEY_REQUEST:
1188             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1189             if (!hci_stack->ssp_auto_accept) break;
1190             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1191             break;
1192 
1193         case HCI_EVENT_ENCRYPTION_CHANGE:
1194             handle = READ_BT_16(packet, 3);
1195             conn = hci_connection_for_handle(handle);
1196             if (!conn) break;
1197             if (packet[2] == 0) {
1198                 if (packet[5]){
1199                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1200                 } else {
1201                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1202                 }
1203             }
1204             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1205             break;
1206 
1207         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1208             handle = READ_BT_16(packet, 3);
1209             conn = hci_connection_for_handle(handle);
1210             if (!conn) break;
1211 
1212             // dedicated bonding: send result and disconnect
1213             if (conn->bonding_flags & BONDING_DEDICATED){
1214                 conn->bonding_flags &= ~BONDING_DEDICATED;
1215                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1216                 conn->bonding_status = packet[2];
1217                 break;
1218             }
1219 
1220             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1221                 // link key sufficient for requested security
1222                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1223                 break;
1224             }
1225             // not enough
1226             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1227             break;
1228 
1229 #ifndef EMBEDDED
1230         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1231             if (!hci_stack->remote_device_db) break;
1232             if (packet[2]) break; // status not ok
1233             bt_flip_addr(addr, &packet[3]);
1234             // fix for invalid remote names - terminate on 0xff
1235             for (i=0; i<248;i++){
1236                 if (packet[9+i] == 0xff){
1237                     packet[9+i] = 0;
1238                     break;
1239                 }
1240             }
1241             memset(&device_name, 0, sizeof(device_name_t));
1242             strncpy((char*) device_name, (char*) &packet[9], 248);
1243             hci_stack->remote_device_db->put_name(&addr, &device_name);
1244             break;
1245 
1246         case HCI_EVENT_INQUIRY_RESULT:
1247         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1248             if (!hci_stack->remote_device_db) break;
1249             // first send inq result packet
1250             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1251             // then send cached remote names
1252             int offset = 3;
1253             for (i=0; i<packet[2];i++){
1254                 bt_flip_addr(addr, &packet[offset]);
1255                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1256                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
1257                     hci_emit_remote_name_cached(&addr, &device_name);
1258                 }
1259             }
1260             return;
1261         }
1262 #endif
1263 
1264         // HCI_EVENT_DISCONNECTION_COMPLETE
1265         // has been split, to first notify stack before shutting connection down
1266         // see end of function, too.
1267         case HCI_EVENT_DISCONNECTION_COMPLETE:
1268             if (packet[2]) break;   // status != 0
1269             handle = READ_BT_16(packet, 3);
1270             hci_connection_t * conn = hci_connection_for_handle(handle);
1271             if (!conn) break;       // no conn struct anymore
1272             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1273             break;
1274 
1275         case HCI_EVENT_HARDWARE_ERROR:
1276             if(hci_stack->control && hci_stack->control->hw_error){
1277                 (*hci_stack->control->hw_error)();
1278             } else {
1279                 // if no special requests, just reboot stack
1280                 hci_power_control_off();
1281                 hci_power_control_on();
1282             }
1283             break;
1284 
1285         case DAEMON_EVENT_HCI_PACKET_SENT:
1286             // release packet buffer only for asynchronous transport and if there are not further fragements
1287             if (hci_transport_synchronous()) {
1288                 log_error("Synchronous HCI Transport shouldn't send DAEMON_EVENT_HCI_PACKET_SENT");
1289                 return; // instead of break: to avoid re-entering hci_run()
1290             }
1291             if (hci_stack->acl_fragmentation_total_size) break;
1292             hci_release_packet_buffer();
1293             break;
1294 
1295 #ifdef HAVE_BLE
1296         case HCI_EVENT_LE_META:
1297             switch (packet[2]){
1298                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1299                     log_info("advertising report received");
1300                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1301                     le_handle_advertisement_report(packet, size);
1302                     break;
1303                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1304                     // Connection management
1305                     bt_flip_addr(addr, &packet[8]);
1306                     addr_type = (bd_addr_type_t)packet[7];
1307                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1308                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1309                     conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1310                     if (packet[3]){
1311                         if (conn){
1312                             // outgoing connection failed, remove entry
1313                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1314                             btstack_memory_hci_connection_free( conn );
1315                         }
1316                         // if authentication error, also delete link key
1317                         if (packet[3] == 0x05) {
1318                             hci_drop_link_key_for_bd_addr(&addr);
1319                         }
1320                         break;
1321                     }
1322                     if (!conn){
1323                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1324                     }
1325                     if (!conn){
1326                         // no memory
1327                         break;
1328                     }
1329 
1330                     conn->state = OPEN;
1331                     conn->con_handle = READ_BT_16(packet, 4);
1332 
1333                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1334 
1335                     // restart timer
1336                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1337                     // run_loop_add_timer(&conn->timeout);
1338 
1339                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1340 
1341                     hci_emit_nr_connections_changed();
1342                     break;
1343 
1344             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1345 
1346                 default:
1347                     break;
1348             }
1349             break;
1350 #endif
1351         default:
1352             break;
1353     }
1354 
1355     // handle BT initialization
1356     if (hci_stack->state == HCI_STATE_INITIALIZING){
1357         hci_initializing_event_handler(packet, size);
1358     }
1359 
1360     // help with BT sleep
1361     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1362         && hci_stack->substate == 1
1363         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1364         hci_stack->substate++;
1365     }
1366 
1367     // notify upper stack
1368     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1369 
1370     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1371     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1372         if (!packet[2]){
1373             handle = READ_BT_16(packet, 3);
1374             hci_connection_t * conn = hci_connection_for_handle(handle);
1375             if (conn) {
1376                 uint8_t status = conn->bonding_status;
1377                 uint16_t flags = conn->bonding_flags;
1378                 bd_addr_t bd_address;
1379                 memcpy(&bd_address, conn->address, 6);
1380                 hci_shutdown_connection(conn);
1381                 // connection struct is gone, don't access anymore
1382                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1383                     hci_emit_dedicated_bonding_result(bd_address, status);
1384                 }
1385             }
1386         }
1387     }
1388 
1389 	// execute main loop
1390 	hci_run();
1391 }
1392 
1393 static void sco_handler(uint8_t * packet, uint16_t size){
1394     // not handled yet
1395 }
1396 
1397 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1398     hci_dump_packet(packet_type, 1, packet, size);
1399     switch (packet_type) {
1400         case HCI_EVENT_PACKET:
1401             event_handler(packet, size);
1402             break;
1403         case HCI_ACL_DATA_PACKET:
1404             acl_handler(packet, size);
1405             break;
1406         case HCI_SCO_DATA_PACKET:
1407             sco_handler(packet, size);
1408         default:
1409             break;
1410     }
1411 }
1412 
1413 /** Register HCI packet handlers */
1414 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1415     hci_stack->packet_handler = handler;
1416 }
1417 
1418 static void hci_state_reset(){
1419     // no connections yet
1420     hci_stack->connections = NULL;
1421 
1422     // keep discoverable/connectable as this has been requested by the client(s)
1423     // hci_stack->discoverable = 0;
1424     // hci_stack->connectable = 0;
1425     // hci_stack->bondable = 1;
1426 
1427     // buffer is free
1428     hci_stack->hci_packet_buffer_reserved = 0;
1429 
1430     // no pending cmds
1431     hci_stack->decline_reason = 0;
1432     hci_stack->new_scan_enable_value = 0xff;
1433 
1434     // LE
1435     hci_stack->adv_addr_type = 0;
1436     memset(hci_stack->adv_address, 0, 6);
1437     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1438     hci_stack->le_scan_type = 0xff;
1439     hci_stack->le_connection_parameter_range.le_conn_interval_min = 0x0006;
1440     hci_stack->le_connection_parameter_range.le_conn_interval_max = 0x0C80;
1441     hci_stack->le_connection_parameter_range.le_conn_latency_min = 0x0000;
1442     hci_stack->le_connection_parameter_range.le_conn_latency_max = 0x03E8;
1443     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = 0x000A;
1444     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 0x0C80;
1445 }
1446 
1447 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1448 
1449 #ifdef HAVE_MALLOC
1450     if (!hci_stack) {
1451         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1452     }
1453 #else
1454     hci_stack = &hci_stack_static;
1455 #endif
1456     memset(hci_stack, 0, sizeof(hci_stack_t));
1457 
1458     // reference to use transport layer implementation
1459     hci_stack->hci_transport = transport;
1460 
1461     // references to used control implementation
1462     hci_stack->control = control;
1463 
1464     // reference to used config
1465     hci_stack->config = config;
1466 
1467     // higher level handler
1468     hci_stack->packet_handler = dummy_handler;
1469 
1470     // store and open remote device db
1471     hci_stack->remote_device_db = remote_device_db;
1472     if (hci_stack->remote_device_db) {
1473         hci_stack->remote_device_db->open();
1474     }
1475 
1476     // max acl payload size defined in config.h
1477     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1478 
1479     // register packet handlers with transport
1480     transport->register_packet_handler(&packet_handler);
1481 
1482     hci_stack->state = HCI_STATE_OFF;
1483 
1484     // class of device
1485     hci_stack->class_of_device = 0x007a020c; // Smartphone
1486 
1487     // bondable by default
1488     hci_stack->bondable = 1;
1489 
1490     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1491     hci_stack->ssp_enable = 1;
1492     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1493     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1494     hci_stack->ssp_auto_accept = 1;
1495 
1496     hci_state_reset();
1497 }
1498 
1499 void hci_close(){
1500     // close remote device db
1501     if (hci_stack->remote_device_db) {
1502         hci_stack->remote_device_db->close();
1503     }
1504     while (hci_stack->connections) {
1505         // cancel all l2cap connections
1506         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1507         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1508     }
1509     hci_power_control(HCI_POWER_OFF);
1510 
1511 #ifdef HAVE_MALLOC
1512     free(hci_stack);
1513 #endif
1514     hci_stack = NULL;
1515 }
1516 
1517 void hci_set_class_of_device(uint32_t class_of_device){
1518     hci_stack->class_of_device = class_of_device;
1519 }
1520 
1521 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
1522 void hci_set_bd_addr(bd_addr_t addr){
1523     memcpy(hci_stack->custom_bd_addr, addr, 6);
1524     hci_stack->custom_bd_addr_set = 1;
1525 }
1526 
1527 void hci_disable_l2cap_timeout_check(){
1528     disable_l2cap_timeouts = 1;
1529 }
1530 // State-Module-Driver overview
1531 // state                    module  low-level
1532 // HCI_STATE_OFF             off      close
1533 // HCI_STATE_INITIALIZING,   on       open
1534 // HCI_STATE_WORKING,        on       open
1535 // HCI_STATE_HALTING,        on       open
1536 // HCI_STATE_SLEEPING,    off/sleep   close
1537 // HCI_STATE_FALLING_ASLEEP  on       open
1538 
1539 static int hci_power_control_on(void){
1540 
1541     // power on
1542     int err = 0;
1543     if (hci_stack->control && hci_stack->control->on){
1544         err = (*hci_stack->control->on)(hci_stack->config);
1545     }
1546     if (err){
1547         log_error( "POWER_ON failed");
1548         hci_emit_hci_open_failed();
1549         return err;
1550     }
1551 
1552     // open low-level device
1553     err = hci_stack->hci_transport->open(hci_stack->config);
1554     if (err){
1555         log_error( "HCI_INIT failed, turning Bluetooth off again");
1556         if (hci_stack->control && hci_stack->control->off){
1557             (*hci_stack->control->off)(hci_stack->config);
1558         }
1559         hci_emit_hci_open_failed();
1560         return err;
1561     }
1562     return 0;
1563 }
1564 
1565 static void hci_power_control_off(void){
1566 
1567     log_info("hci_power_control_off");
1568 
1569     // close low-level device
1570     hci_stack->hci_transport->close(hci_stack->config);
1571 
1572     log_info("hci_power_control_off - hci_transport closed");
1573 
1574     // power off
1575     if (hci_stack->control && hci_stack->control->off){
1576         (*hci_stack->control->off)(hci_stack->config);
1577     }
1578 
1579     log_info("hci_power_control_off - control closed");
1580 
1581     hci_stack->state = HCI_STATE_OFF;
1582 }
1583 
1584 static void hci_power_control_sleep(void){
1585 
1586     log_info("hci_power_control_sleep");
1587 
1588 #if 0
1589     // don't close serial port during sleep
1590 
1591     // close low-level device
1592     hci_stack->hci_transport->close(hci_stack->config);
1593 #endif
1594 
1595     // sleep mode
1596     if (hci_stack->control && hci_stack->control->sleep){
1597         (*hci_stack->control->sleep)(hci_stack->config);
1598     }
1599 
1600     hci_stack->state = HCI_STATE_SLEEPING;
1601 }
1602 
1603 static int hci_power_control_wake(void){
1604 
1605     log_info("hci_power_control_wake");
1606 
1607     // wake on
1608     if (hci_stack->control && hci_stack->control->wake){
1609         (*hci_stack->control->wake)(hci_stack->config);
1610     }
1611 
1612 #if 0
1613     // open low-level device
1614     int err = hci_stack->hci_transport->open(hci_stack->config);
1615     if (err){
1616         log_error( "HCI_INIT failed, turning Bluetooth off again");
1617         if (hci_stack->control && hci_stack->control->off){
1618             (*hci_stack->control->off)(hci_stack->config);
1619         }
1620         hci_emit_hci_open_failed();
1621         return err;
1622     }
1623 #endif
1624 
1625     return 0;
1626 }
1627 
1628 static void hci_power_transition_to_initializing(void){
1629     // set up state machine
1630     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1631     hci_stack->hci_packet_buffer_reserved = 0;
1632     hci_stack->state = HCI_STATE_INITIALIZING;
1633     hci_stack->substate = 0;
1634 }
1635 
1636 int hci_power_control(HCI_POWER_MODE power_mode){
1637 
1638     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1639 
1640     int err = 0;
1641     switch (hci_stack->state){
1642 
1643         case HCI_STATE_OFF:
1644             switch (power_mode){
1645                 case HCI_POWER_ON:
1646                     err = hci_power_control_on();
1647                     if (err) {
1648                         log_error("hci_power_control_on() error %u", err);
1649                         return err;
1650                     }
1651                     hci_power_transition_to_initializing();
1652                     break;
1653                 case HCI_POWER_OFF:
1654                     // do nothing
1655                     break;
1656                 case HCI_POWER_SLEEP:
1657                     // do nothing (with SLEEP == OFF)
1658                     break;
1659             }
1660             break;
1661 
1662         case HCI_STATE_INITIALIZING:
1663             switch (power_mode){
1664                 case HCI_POWER_ON:
1665                     // do nothing
1666                     break;
1667                 case HCI_POWER_OFF:
1668                     // no connections yet, just turn it off
1669                     hci_power_control_off();
1670                     break;
1671                 case HCI_POWER_SLEEP:
1672                     // no connections yet, just turn it off
1673                     hci_power_control_sleep();
1674                     break;
1675             }
1676             break;
1677 
1678         case HCI_STATE_WORKING:
1679             switch (power_mode){
1680                 case HCI_POWER_ON:
1681                     // do nothing
1682                     break;
1683                 case HCI_POWER_OFF:
1684                     // see hci_run
1685                     hci_stack->state = HCI_STATE_HALTING;
1686                     break;
1687                 case HCI_POWER_SLEEP:
1688                     // see hci_run
1689                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1690                     hci_stack->substate = 0;
1691                     break;
1692             }
1693             break;
1694 
1695         case HCI_STATE_HALTING:
1696             switch (power_mode){
1697                 case HCI_POWER_ON:
1698                     hci_power_transition_to_initializing();
1699                     break;
1700                 case HCI_POWER_OFF:
1701                     // do nothing
1702                     break;
1703                 case HCI_POWER_SLEEP:
1704                     // see hci_run
1705                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1706                     hci_stack->substate = 0;
1707                     break;
1708             }
1709             break;
1710 
1711         case HCI_STATE_FALLING_ASLEEP:
1712             switch (power_mode){
1713                 case HCI_POWER_ON:
1714 
1715 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1716                     // nothing to do, if H4 supports power management
1717                     if (bt_control_iphone_power_management_enabled()){
1718                         hci_stack->state = HCI_STATE_INITIALIZING;
1719                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1720                         break;
1721                     }
1722 #endif
1723                     hci_power_transition_to_initializing();
1724                     break;
1725                 case HCI_POWER_OFF:
1726                     // see hci_run
1727                     hci_stack->state = HCI_STATE_HALTING;
1728                     break;
1729                 case HCI_POWER_SLEEP:
1730                     // do nothing
1731                     break;
1732             }
1733             break;
1734 
1735         case HCI_STATE_SLEEPING:
1736             switch (power_mode){
1737                 case HCI_POWER_ON:
1738 
1739 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1740                     // nothing to do, if H4 supports power management
1741                     if (bt_control_iphone_power_management_enabled()){
1742                         hci_stack->state = HCI_STATE_INITIALIZING;
1743                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1744                         hci_update_scan_enable();
1745                         break;
1746                     }
1747 #endif
1748                     err = hci_power_control_wake();
1749                     if (err) return err;
1750                     hci_power_transition_to_initializing();
1751                     break;
1752                 case HCI_POWER_OFF:
1753                     hci_stack->state = HCI_STATE_HALTING;
1754                     break;
1755                 case HCI_POWER_SLEEP:
1756                     // do nothing
1757                     break;
1758             }
1759             break;
1760     }
1761 
1762     // create internal event
1763 	hci_emit_state();
1764 
1765 	// trigger next/first action
1766 	hci_run();
1767 
1768     return 0;
1769 }
1770 
1771 static void hci_update_scan_enable(void){
1772     // 2 = page scan, 1 = inq scan
1773     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1774     hci_run();
1775 }
1776 
1777 void hci_discoverable_control(uint8_t enable){
1778     if (enable) enable = 1; // normalize argument
1779 
1780     if (hci_stack->discoverable == enable){
1781         hci_emit_discoverable_enabled(hci_stack->discoverable);
1782         return;
1783     }
1784 
1785     hci_stack->discoverable = enable;
1786     hci_update_scan_enable();
1787 }
1788 
1789 void hci_connectable_control(uint8_t enable){
1790     if (enable) enable = 1; // normalize argument
1791 
1792     // don't emit event
1793     if (hci_stack->connectable == enable) return;
1794 
1795     hci_stack->connectable = enable;
1796     hci_update_scan_enable();
1797 }
1798 
1799 bd_addr_t * hci_local_bd_addr(void){
1800     return &hci_stack->local_bd_addr;
1801 }
1802 
1803 void hci_run(){
1804 
1805     hci_connection_t * connection;
1806     linked_item_t * it;
1807 
1808     // send continuation fragments first, as they block the prepared packet buffer
1809     if (hci_stack->acl_fragmentation_total_size > 0) {
1810         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1811         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1812             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1813             if (connection) {
1814                 hci_send_acl_packet_fragments(connection);
1815                 return;
1816             }
1817             // connection gone -> discard further fragments
1818             hci_stack->acl_fragmentation_total_size = 0;
1819             hci_stack->acl_fragmentation_pos = 0;
1820         }
1821     }
1822 
1823     if (!hci_can_send_command_packet_now()) return;
1824 
1825     // global/non-connection oriented commands
1826 
1827     // decline incoming connections
1828     if (hci_stack->decline_reason){
1829         uint8_t reason = hci_stack->decline_reason;
1830         hci_stack->decline_reason = 0;
1831         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1832         return;
1833     }
1834 
1835     // send scan enable
1836     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1837         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1838         hci_stack->new_scan_enable_value = 0xff;
1839         return;
1840     }
1841 
1842 #ifdef HAVE_BLE
1843     // handle le scan
1844     if (hci_stack->state == HCI_STATE_WORKING){
1845         switch(hci_stack->le_scanning_state){
1846             case LE_START_SCAN:
1847                 hci_stack->le_scanning_state = LE_SCANNING;
1848                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1849                 return;
1850 
1851             case LE_STOP_SCAN:
1852                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1853                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1854                 return;
1855             default:
1856                 break;
1857         }
1858         if (hci_stack->le_scan_type != 0xff){
1859             // defaults: active scanning, accept all advertisement packets
1860             int scan_type = hci_stack->le_scan_type;
1861             hci_stack->le_scan_type = 0xff;
1862             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);
1863             return;
1864         }
1865     }
1866 #endif
1867 
1868     // send pending HCI commands
1869     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1870         connection = (hci_connection_t *) it;
1871 
1872         switch(connection->state){
1873             case SEND_CREATE_CONNECTION:
1874                 switch(connection->address_type){
1875                     case BD_ADDR_TYPE_CLASSIC:
1876                         log_info("sending hci_create_connection");
1877                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1878                         break;
1879                     default:
1880 #ifdef HAVE_BLE
1881                         log_info("sending hci_le_create_connection");
1882                         hci_send_cmd(&hci_le_create_connection,
1883                                      0x0060,    // scan interval: 60 ms
1884                                      0x0030,    // scan interval: 30 ms
1885                                      0,         // don't use whitelist
1886                                      connection->address_type, // peer address type
1887                                      connection->address,      // peer bd addr
1888                                      hci_stack->adv_addr_type, // our addr type:
1889                                      0x0008,    // conn interval min
1890                                      0x0018,    // conn interval max
1891                                      0,         // conn latency
1892                                      0x0048,    // supervision timeout
1893                                      0x0001,    // min ce length
1894                                      0x0001     // max ce length
1895                                      );
1896 
1897                         connection->state = SENT_CREATE_CONNECTION;
1898 #endif
1899                         break;
1900                 }
1901                 return;
1902 
1903             case RECEIVED_CONNECTION_REQUEST:
1904                 log_info("sending hci_accept_connection_request");
1905                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1906                 hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1907                 return;
1908 
1909 #ifdef HAVE_BLE
1910             case SEND_CANCEL_CONNECTION:
1911                 connection->state = SENT_CANCEL_CONNECTION;
1912                 hci_send_cmd(&hci_le_create_connection_cancel);
1913                 return;
1914 #endif
1915             case SEND_DISCONNECT:
1916                 connection->state = SENT_DISCONNECT;
1917                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
1918                 return;
1919 
1920             default:
1921                 break;
1922         }
1923 
1924         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1925             log_info("responding to link key request");
1926             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1927             link_key_t link_key;
1928             link_key_type_t link_key_type;
1929             if ( hci_stack->remote_device_db
1930               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
1931               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
1932                connection->link_key_type = link_key_type;
1933                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1934             } else {
1935                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1936             }
1937             return;
1938         }
1939 
1940         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
1941             log_info("denying to pin request");
1942             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
1943             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1944             return;
1945         }
1946 
1947         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1948             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1949             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
1950             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
1951                 // tweak authentication requirements
1952                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
1953                 if (connection->bonding_flags & BONDING_DEDICATED){
1954                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
1955                 }
1956                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
1957                     authreq |= 1;
1958                 }
1959                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
1960             } else {
1961                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1962             }
1963             return;
1964         }
1965 
1966         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1967             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1968             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1969             return;
1970         }
1971 
1972         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1973             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1974             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1975             return;
1976         }
1977 
1978         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1979             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1980             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1981             return;
1982         }
1983 
1984         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
1985             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
1986             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
1987             return;
1988         }
1989         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
1990             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
1991             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
1992             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
1993             return;
1994         }
1995         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
1996             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
1997             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
1998             return;
1999         }
2000         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2001             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2002             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2003             return;
2004         }
2005 
2006 #ifdef HAVE_BLE
2007         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2008             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2009 
2010             uint16_t connection_interval_min = connection->le_conn_interval_min;
2011             connection->le_conn_interval_min = 0;
2012             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2013                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2014                 0x0000, 0xffff);
2015         }
2016 #endif
2017     }
2018 
2019     switch (hci_stack->state){
2020         case HCI_STATE_INITIALIZING:
2021             hci_initializing_state_machine();
2022             break;
2023 
2024         case HCI_STATE_HALTING:
2025 
2026             log_info("HCI_STATE_HALTING");
2027             // close all open connections
2028             connection =  (hci_connection_t *) hci_stack->connections;
2029             if (connection){
2030 
2031                 // send disconnect
2032                 if (!hci_can_send_command_packet_now()) return;
2033 
2034                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2035                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2036 
2037                 // send disconnected event right away - causes higher layer connections to get closed, too.
2038                 hci_shutdown_connection(connection);
2039                 return;
2040             }
2041             log_info("HCI_STATE_HALTING, calling off");
2042 
2043             // switch mode
2044             hci_power_control_off();
2045 
2046             log_info("HCI_STATE_HALTING, emitting state");
2047             hci_emit_state();
2048             log_info("HCI_STATE_HALTING, done");
2049             break;
2050 
2051         case HCI_STATE_FALLING_ASLEEP:
2052             switch(hci_stack->substate) {
2053                 case 0:
2054                     log_info("HCI_STATE_FALLING_ASLEEP");
2055                     // close all open connections
2056                     connection =  (hci_connection_t *) hci_stack->connections;
2057 
2058 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2059                     // don't close connections, if H4 supports power management
2060                     if (bt_control_iphone_power_management_enabled()){
2061                         connection = NULL;
2062                     }
2063 #endif
2064                     if (connection){
2065 
2066                         // send disconnect
2067                         if (!hci_can_send_command_packet_now()) return;
2068 
2069                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2070                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2071 
2072                         // send disconnected event right away - causes higher layer connections to get closed, too.
2073                         hci_shutdown_connection(connection);
2074                         return;
2075                     }
2076 
2077                     if (hci_classic_supported()){
2078                         // disable page and inquiry scan
2079                         if (!hci_can_send_command_packet_now()) return;
2080 
2081                         log_info("HCI_STATE_HALTING, disabling inq scans");
2082                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2083 
2084                         // continue in next sub state
2085                         hci_stack->substate++;
2086                         break;
2087                     }
2088                     // fall through for ble-only chips
2089 
2090                 case 2:
2091                     log_info("HCI_STATE_HALTING, calling sleep");
2092 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2093                     // don't actually go to sleep, if H4 supports power management
2094                     if (bt_control_iphone_power_management_enabled()){
2095                         // SLEEP MODE reached
2096                         hci_stack->state = HCI_STATE_SLEEPING;
2097                         hci_emit_state();
2098                         break;
2099                     }
2100 #endif
2101                     // switch mode
2102                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2103                     hci_emit_state();
2104                     break;
2105 
2106                 default:
2107                     break;
2108             }
2109             break;
2110 
2111         default:
2112             break;
2113     }
2114 }
2115 
2116 int hci_send_cmd_packet(uint8_t *packet, int size){
2117     bd_addr_t addr;
2118     hci_connection_t * conn;
2119     // house-keeping
2120 
2121     // create_connection?
2122     if (IS_COMMAND(packet, hci_create_connection)){
2123         bt_flip_addr(addr, &packet[3]);
2124         log_info("Create_connection to %s", bd_addr_to_str(addr));
2125 
2126         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2127         if (!conn){
2128             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2129             if (!conn){
2130                 // notify client that alloc failed
2131                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2132                 return 0; // don't sent packet to controller
2133             }
2134             conn->state = SEND_CREATE_CONNECTION;
2135         }
2136         log_info("conn state %u", conn->state);
2137         switch (conn->state){
2138             // if connection active exists
2139             case OPEN:
2140                 // and OPEN, emit connection complete command, don't send to controller
2141                 hci_emit_connection_complete(conn, 0);
2142                 return 0;
2143             case SEND_CREATE_CONNECTION:
2144                 // connection created by hci, e.g. dedicated bonding
2145                 break;
2146             default:
2147                 // otherwise, just ignore as it is already in the open process
2148                 return 0;
2149         }
2150         conn->state = SENT_CREATE_CONNECTION;
2151     }
2152 
2153     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2154         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2155     }
2156     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2157         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2158     }
2159 
2160     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2161         if (hci_stack->remote_device_db){
2162             bt_flip_addr(addr, &packet[3]);
2163             hci_stack->remote_device_db->delete_link_key(&addr);
2164         }
2165     }
2166 
2167     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2168     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2169         bt_flip_addr(addr, &packet[3]);
2170         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2171         if (conn){
2172             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2173         }
2174     }
2175 
2176     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2177     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2178     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2179     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2180         bt_flip_addr(addr, &packet[3]);
2181         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2182         if (conn){
2183             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2184         }
2185     }
2186 
2187 #ifdef HAVE_BLE
2188     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2189         hci_stack->adv_addr_type = packet[8];
2190     }
2191     if (IS_COMMAND(packet, hci_le_set_random_address)){
2192         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2193     }
2194 #endif
2195 
2196     hci_stack->num_cmd_packets--;
2197 
2198     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2199     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2200 
2201     // release packet buffer for synchronous transport implementations
2202     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2203         hci_stack->hci_packet_buffer_reserved = 0;
2204     }
2205 
2206     return err;
2207 }
2208 
2209 // disconnect because of security block
2210 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2211     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2212     if (!connection) return;
2213     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2214 }
2215 
2216 
2217 // Configure Secure Simple Pairing
2218 
2219 // enable will enable SSP during init
2220 void hci_ssp_set_enable(int enable){
2221     hci_stack->ssp_enable = enable;
2222 }
2223 
2224 int hci_local_ssp_activated(){
2225     return hci_ssp_supported() && hci_stack->ssp_enable;
2226 }
2227 
2228 // if set, BTstack will respond to io capability request using authentication requirement
2229 void hci_ssp_set_io_capability(int io_capability){
2230     hci_stack->ssp_io_capability = io_capability;
2231 }
2232 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2233     hci_stack->ssp_authentication_requirement = authentication_requirement;
2234 }
2235 
2236 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2237 void hci_ssp_set_auto_accept(int auto_accept){
2238     hci_stack->ssp_auto_accept = auto_accept;
2239 }
2240 
2241 /**
2242  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2243  */
2244 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2245 
2246     if (!hci_can_send_command_packet_now()){
2247         log_error("hci_send_cmd called but cannot send packet now");
2248         return 0;
2249     }
2250 
2251     // for HCI INITIALIZATION
2252     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2253     hci_stack->last_cmd_opcode = cmd->opcode;
2254 
2255     hci_reserve_packet_buffer();
2256     uint8_t * packet = hci_stack->hci_packet_buffer;
2257 
2258     va_list argptr;
2259     va_start(argptr, cmd);
2260     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2261     va_end(argptr);
2262 
2263     return hci_send_cmd_packet(packet, size);
2264 }
2265 
2266 // Create various non-HCI events.
2267 // TODO: generalize, use table similar to hci_create_command
2268 
2269 void hci_emit_state(){
2270     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2271     uint8_t event[3];
2272     event[0] = BTSTACK_EVENT_STATE;
2273     event[1] = sizeof(event) - 2;
2274     event[2] = hci_stack->state;
2275     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2276     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2277 }
2278 
2279 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2280     uint8_t event[13];
2281     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2282     event[1] = sizeof(event) - 2;
2283     event[2] = status;
2284     bt_store_16(event, 3, conn->con_handle);
2285     bt_flip_addr(&event[5], conn->address);
2286     event[11] = 1; // ACL connection
2287     event[12] = 0; // encryption disabled
2288     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2289     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2290 }
2291 
2292 void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t * address, uint16_t conn_handle, uint8_t status){
2293     uint8_t event[21];
2294     event[0] = HCI_EVENT_LE_META;
2295     event[1] = sizeof(event) - 2;
2296     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2297     event[3] = status;
2298     bt_store_16(event, 4, conn_handle);
2299     event[6] = 0; // TODO: role
2300     event[7] = address_type;
2301     bt_flip_addr(&event[8], *address);
2302     bt_store_16(event, 14, 0); // interval
2303     bt_store_16(event, 16, 0); // latency
2304     bt_store_16(event, 18, 0); // supervision timeout
2305     event[20] = 0; // master clock accuracy
2306     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2307     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2308 }
2309 
2310 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2311     uint8_t event[6];
2312     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2313     event[1] = sizeof(event) - 2;
2314     event[2] = 0; // status = OK
2315     bt_store_16(event, 3, handle);
2316     event[5] = reason;
2317     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2318     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2319 }
2320 
2321 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2322     if (disable_l2cap_timeouts) return;
2323     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2324     uint8_t event[4];
2325     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2326     event[1] = sizeof(event) - 2;
2327     bt_store_16(event, 2, conn->con_handle);
2328     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2329     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2330 }
2331 
2332 void hci_emit_nr_connections_changed(){
2333     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2334     uint8_t event[3];
2335     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2336     event[1] = sizeof(event) - 2;
2337     event[2] = nr_hci_connections();
2338     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2339     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2340 }
2341 
2342 void hci_emit_hci_open_failed(){
2343     log_info("BTSTACK_EVENT_POWERON_FAILED");
2344     uint8_t event[2];
2345     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2346     event[1] = sizeof(event) - 2;
2347     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2348     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2349 }
2350 
2351 #ifndef EMBEDDED
2352 void hci_emit_btstack_version() {
2353     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2354     uint8_t event[6];
2355     event[0] = BTSTACK_EVENT_VERSION;
2356     event[1] = sizeof(event) - 2;
2357     event[2] = BTSTACK_MAJOR;
2358     event[3] = BTSTACK_MINOR;
2359     bt_store_16(event, 4, BTSTACK_REVISION);
2360     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2361     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2362 }
2363 #endif
2364 
2365 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2366     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2367     uint8_t event[3];
2368     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2369     event[1] = sizeof(event) - 2;
2370     event[2] = enabled;
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_remote_name_cached(bd_addr_t *addr, device_name_t *name){
2376     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2377     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2378     event[1] = sizeof(event) - 2 - 1;
2379     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2380     bt_flip_addr(&event[3], *addr);
2381     memcpy(&event[9], name, 248);
2382 
2383     event[9+248] = 0;   // assert \0 for log_info
2384     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
2385 
2386     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2387     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2388 }
2389 
2390 void hci_emit_discoverable_enabled(uint8_t enabled){
2391     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2392     uint8_t event[3];
2393     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2394     event[1] = sizeof(event) - 2;
2395     event[2] = enabled;
2396     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2397     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2398 }
2399 
2400 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2401     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2402     uint8_t event[5];
2403     int pos = 0;
2404     event[pos++] = GAP_SECURITY_LEVEL;
2405     event[pos++] = sizeof(event) - 2;
2406     bt_store_16(event, 2, con_handle);
2407     pos += 2;
2408     event[pos++] = level;
2409     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2410     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2411 }
2412 
2413 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2414     log_info("hci_emit_dedicated_bonding_result %u ", status);
2415     uint8_t event[9];
2416     int pos = 0;
2417     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2418     event[pos++] = sizeof(event) - 2;
2419     event[pos++] = status;
2420     bt_flip_addr( * (bd_addr_t *) &event[pos], address);
2421     pos += 6;
2422     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2423     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2424 }
2425 
2426 // query if remote side supports SSP
2427 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2428     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2429     if (!connection) return 0;
2430     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2431 }
2432 
2433 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2434     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2435 }
2436 
2437 // GAP API
2438 /**
2439  * @bbrief enable/disable bonding. default is enabled
2440  * @praram enabled
2441  */
2442 void gap_set_bondable_mode(int enable){
2443     hci_stack->bondable = enable ? 1 : 0;
2444 }
2445 
2446 /**
2447  * @brief map link keys to security levels
2448  */
2449 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2450     switch (link_key_type){
2451         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2452             return LEVEL_4;
2453         case COMBINATION_KEY:
2454         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2455             return LEVEL_3;
2456         default:
2457             return LEVEL_2;
2458     }
2459 }
2460 
2461 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2462     if (!connection) return LEVEL_0;
2463     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2464     return gap_security_level_for_link_key_type(connection->link_key_type);
2465 }
2466 
2467 
2468 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2469     log_info("gap_mitm_protection_required_for_security_level %u", level);
2470     return level > LEVEL_2;
2471 }
2472 
2473 /**
2474  * @brief get current security level
2475  */
2476 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2477     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2478     if (!connection) return LEVEL_0;
2479     return gap_security_level_for_connection(connection);
2480 }
2481 
2482 /**
2483  * @brief request connection to device to
2484  * @result GAP_AUTHENTICATION_RESULT
2485  */
2486 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2487     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2488     if (!connection){
2489         hci_emit_security_level(con_handle, LEVEL_0);
2490         return;
2491     }
2492     gap_security_level_t current_level = gap_security_level(con_handle);
2493     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2494     if (current_level >= requested_level){
2495         hci_emit_security_level(con_handle, current_level);
2496         return;
2497     }
2498 
2499     connection->requested_security_level = requested_level;
2500 
2501 #if 0
2502     // sending encryption request without a link key results in an error.
2503     // TODO: figure out how to use it properly
2504 
2505     // would enabling ecnryption suffice (>= LEVEL_2)?
2506     if (hci_stack->remote_device_db){
2507         link_key_type_t link_key_type;
2508         link_key_t      link_key;
2509         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2510             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2511                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2512                 return;
2513             }
2514         }
2515     }
2516 #endif
2517 
2518     // try to authenticate connection
2519     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2520     hci_run();
2521 }
2522 
2523 /**
2524  * @brief start dedicated bonding with device. disconnect after bonding
2525  * @param device
2526  * @param request MITM protection
2527  * @result GAP_DEDICATED_BONDING_COMPLETE
2528  */
2529 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2530 
2531     // create connection state machine
2532     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2533 
2534     if (!connection){
2535         return BTSTACK_MEMORY_ALLOC_FAILED;
2536     }
2537 
2538     // delete linkn key
2539     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2540 
2541     // configure LEVEL_2/3, dedicated bonding
2542     connection->state = SEND_CREATE_CONNECTION;
2543     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2544     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2545     connection->bonding_flags = BONDING_DEDICATED;
2546 
2547     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2548 
2549     // handle: connnection failure (connection complete != ok)
2550     // handle: authentication failure
2551     // handle: disconnect on done
2552 
2553     hci_run();
2554 
2555     return 0;
2556 }
2557 
2558 void gap_set_local_name(const char * local_name){
2559     hci_stack->local_name = local_name;
2560 }
2561 
2562 le_command_status_t le_central_start_scan(){
2563     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2564     hci_stack->le_scanning_state = LE_START_SCAN;
2565     hci_run();
2566     return BLE_PERIPHERAL_OK;
2567 }
2568 
2569 le_command_status_t le_central_stop_scan(){
2570     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2571     hci_stack->le_scanning_state = LE_STOP_SCAN;
2572     hci_run();
2573     return BLE_PERIPHERAL_OK;
2574 }
2575 
2576 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2577     hci_stack->le_scan_type     = scan_type;
2578     hci_stack->le_scan_interval = scan_interval;
2579     hci_stack->le_scan_window   = scan_window;
2580     hci_run();
2581 }
2582 
2583 le_command_status_t le_central_connect(bd_addr_t * addr, bd_addr_type_t addr_type){
2584     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2585     if (!conn){
2586         log_info("le_central_connect: no connection exists yet, creating context");
2587         conn = create_connection_for_bd_addr_and_type(*addr, addr_type);
2588         if (!conn){
2589             // notify client that alloc failed
2590             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
2591             log_info("le_central_connect: failed to alloc hci_connection_t");
2592             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2593         }
2594         conn->state = SEND_CREATE_CONNECTION;
2595         log_info("le_central_connect: send create connection next");
2596         hci_run();
2597         return BLE_PERIPHERAL_OK;
2598     }
2599 
2600     if (!hci_is_le_connection(conn) ||
2601         conn->state == SEND_CREATE_CONNECTION ||
2602         conn->state == SENT_CREATE_CONNECTION) {
2603         hci_emit_le_connection_complete(conn->address_type, &conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
2604         log_error("le_central_connect: classic connection or connect is already being created");
2605         return BLE_PERIPHERAL_IN_WRONG_STATE;
2606     }
2607 
2608     log_info("le_central_connect: context exists with state %u", conn->state);
2609     hci_emit_le_connection_complete(conn->address_type, &conn->address, conn->con_handle, 0);
2610     hci_run();
2611     return BLE_PERIPHERAL_OK;
2612 }
2613 
2614 // @assumption: only a single outgoing LE Connection exists
2615 static hci_connection_t * le_central_get_outgoing_connection(){
2616     linked_item_t *it;
2617     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2618         hci_connection_t * conn = (hci_connection_t *) it;
2619         if (!hci_is_le_connection(conn)) continue;
2620         switch (conn->state){
2621             case SEND_CREATE_CONNECTION:
2622             case SENT_CREATE_CONNECTION:
2623                 return conn;
2624             default:
2625                 break;
2626         };
2627     }
2628     return NULL;
2629 }
2630 
2631 le_command_status_t le_central_connect_cancel(){
2632     hci_connection_t * conn = le_central_get_outgoing_connection();
2633     switch (conn->state){
2634         case SEND_CREATE_CONNECTION:
2635             // skip sending create connection and emit event instead
2636             hci_emit_le_connection_complete(conn->address_type, &conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2637             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2638             btstack_memory_hci_connection_free( conn );
2639             break;
2640         case SENT_CREATE_CONNECTION:
2641             // request to send cancel connection
2642             conn->state = SEND_CANCEL_CONNECTION;
2643             hci_run();
2644             break;
2645         default:
2646             break;
2647     }
2648     return BLE_PERIPHERAL_OK;
2649 }
2650 
2651 /**
2652  * @brief Updates the connection parameters for a given LE connection
2653  * @param handle
2654  * @param conn_interval_min (unit: 1.25ms)
2655  * @param conn_interval_max (unit: 1.25ms)
2656  * @param conn_latency
2657  * @param supervision_timeout (unit: 10ms)
2658  * @returns 0 if ok
2659  */
2660 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2661     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2662     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2663     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2664     connection->le_conn_interval_min = conn_interval_min;
2665     connection->le_conn_interval_max = conn_interval_max;
2666     connection->le_conn_latency = conn_latency;
2667     connection->le_supervision_timeout = supervision_timeout;
2668     return 0;
2669 }
2670 
2671 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2672     hci_connection_t * conn = hci_connection_for_handle(handle);
2673     if (!conn){
2674         hci_emit_disconnection_complete(handle, 0);
2675         return BLE_PERIPHERAL_OK;
2676     }
2677     conn->state = SEND_DISCONNECT;
2678     hci_run();
2679     return BLE_PERIPHERAL_OK;
2680 }
2681 
2682 void hci_disconnect_all(){
2683     linked_list_iterator_t it;
2684     linked_list_iterator_init(&it, &hci_stack->connections);
2685     while (linked_list_iterator_has_next(&it)){
2686         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2687         if (con->state == SENT_DISCONNECT) continue;
2688         con->state = SEND_DISCONNECT;
2689     }
2690     hci_run();
2691 }
2692