xref: /btstack/src/hci.c (revision e35edcc121f2d8c6e357d758e82968ac2e1b79de)
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 int hci_number_free_sco_slots_for_handle(hci_con_handle_t handle){
350     int num_sco_packets_sent = 0;
351     linked_item_t *it;
352     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
353         hci_connection_t * connection = (hci_connection_t *) it;
354         num_sco_packets_sent += connection->num_sco_packets_sent;
355     }
356     if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
357         log_info("hci_number_free_sco_slots_for_handle: outgoing packets (%u) > total packets ()", num_sco_packets_sent, hci_stack->sco_packets_total_num);
358         return 0;
359     }
360     return hci_stack->sco_packets_total_num - num_sco_packets_sent;
361 }
362 
363 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
364 int hci_can_send_command_packet_now(void){
365     if (hci_stack->hci_packet_buffer_reserved) return 0;
366 
367     // check for async hci transport implementations
368     if (hci_stack->hci_transport->can_send_packet_now){
369         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
370             return 0;
371         }
372     }
373 
374     return hci_stack->num_cmd_packets > 0;
375 }
376 
377 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
378     // check for async hci transport implementations
379     if (hci_stack->hci_transport->can_send_packet_now){
380         if (!hci_stack->hci_transport->can_send_packet_now(HCI_ACL_DATA_PACKET)){
381             return 0;
382         }
383     }
384     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
385 }
386 
387 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
388     if (hci_stack->hci_packet_buffer_reserved) return 0;
389     return hci_can_send_prepared_acl_packet_now(con_handle);
390 }
391 
392 int hci_can_send_prepared_sco_packet_now(hci_con_handle_t con_handle){
393     if (hci_stack->hci_transport->can_send_packet_now){
394         if (!hci_stack->hci_transport->can_send_packet_now(HCI_SCO_DATA_PACKET)){
395             return 0;
396         }
397     }
398     return hci_number_free_sco_slots_for_handle(con_handle) > 0;
399 }
400 
401 int hci_can_send_sco_packet_now(hci_con_handle_t con_handle){
402     if (hci_stack->hci_packet_buffer_reserved) return 0;
403     return hci_can_send_prepared_sco_packet_now(con_handle);
404 }
405 
406 // used for internal checks in l2cap[-le].c
407 int hci_is_packet_buffer_reserved(void){
408     return hci_stack->hci_packet_buffer_reserved;
409 }
410 
411 // reserves outgoing packet buffer. @returns 1 if successful
412 int hci_reserve_packet_buffer(void){
413     if (hci_stack->hci_packet_buffer_reserved) {
414         log_error("hci_reserve_packet_buffer called but buffer already reserved");
415         return 0;
416     }
417     hci_stack->hci_packet_buffer_reserved = 1;
418     return 1;
419 }
420 
421 void hci_release_packet_buffer(void){
422     hci_stack->hci_packet_buffer_reserved = 0;
423 }
424 
425 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
426 int hci_transport_synchronous(void){
427     return hci_stack->hci_transport->can_send_packet_now == NULL;
428 }
429 
430 uint16_t hci_max_acl_le_data_packet_length(void){
431     return hci_stack->le_data_packets_length > 0 ? hci_stack->le_data_packets_length : hci_stack->acl_data_packet_length;
432 }
433 
434 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
435 
436     // log_info("hci_send_acl_packet_fragments  %u/%u (con 0x%04x)", hci_stack->acl_fragmentation_pos, hci_stack->acl_fragmentation_total_size, connection->con_handle);
437 
438     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
439     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
440     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
441         max_acl_data_packet_length = hci_stack->le_data_packets_length;
442     }
443 
444     // testing: reduce buffer to minimum
445     // max_acl_data_packet_length = 52;
446 
447     int err;
448     // multiple packets could be send on a synchronous HCI transport
449     while (1){
450 
451         // get current data
452         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
453         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
454         int more_fragments = 0;
455 
456         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
457         if (current_acl_data_packet_length > max_acl_data_packet_length){
458             more_fragments = 1;
459             current_acl_data_packet_length = max_acl_data_packet_length;
460         }
461 
462         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
463         if (acl_header_pos > 0){
464             uint16_t handle_and_flags = READ_BT_16(hci_stack->hci_packet_buffer, 0);
465             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
466             bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
467         }
468 
469         // update header len
470         bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
471 
472         // count packet
473         connection->num_acl_packets_sent++;
474 
475         // send packet
476         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
477         const int size = current_acl_data_packet_length + 4;
478         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
479         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
480 
481         // done yet?
482         if (!more_fragments) break;
483 
484         // update start of next fragment to send
485         hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
486 
487         // can send more?
488         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
489     }
490 
491     // done
492     hci_stack->acl_fragmentation_pos = 0;
493     hci_stack->acl_fragmentation_total_size = 0;
494 
495     // release buffer now for synchronous transport
496     if (hci_transport_synchronous()){
497         hci_release_packet_buffer();
498     }
499 
500     return err;
501 }
502 
503 // pre: caller has reserved the packet buffer
504 int hci_send_acl_packet_buffer(int size){
505 
506     // log_info("hci_send_acl_packet_buffer size %u", size);
507 
508     if (!hci_stack->hci_packet_buffer_reserved) {
509         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
510         return 0;
511     }
512 
513     uint8_t * packet = hci_stack->hci_packet_buffer;
514     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
515 
516     // check for free places on Bluetooth module
517     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
518         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
519         hci_release_packet_buffer();
520         return BTSTACK_ACL_BUFFERS_FULL;
521     }
522 
523     hci_connection_t *connection = hci_connection_for_handle( con_handle);
524     if (!connection) {
525         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
526         hci_release_packet_buffer();
527         return 0;
528     }
529     hci_connection_timestamp(connection);
530 
531     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
532 
533     // setup data
534     hci_stack->acl_fragmentation_total_size = size;
535     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
536 
537     return hci_send_acl_packet_fragments(connection);
538 }
539 
540 // pre: caller has reserved the packet buffer
541 int hci_send_sco_packet_buffer(int size){
542 
543     // log_info("hci_send_acl_packet_buffer size %u", size);
544 
545     if (!hci_stack->hci_packet_buffer_reserved) {
546         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
547         return 0;
548     }
549 
550     uint8_t * packet = hci_stack->hci_packet_buffer;
551     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
552 
553     // check for free places on Bluetooth module
554     if (!hci_can_send_prepared_sco_packet_now(con_handle)) {
555         log_error("hci_send_sco_packet_buffer called but no free ACL buffers on controller");
556         hci_release_packet_buffer();
557         return BTSTACK_ACL_BUFFERS_FULL;
558     }
559 
560     // track send packet in connection struct
561     hci_connection_t *connection = hci_connection_for_handle( con_handle);
562     if (!connection) {
563         log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
564         hci_release_packet_buffer();
565         return 0;
566     }
567     connection->num_sco_packets_sent++;
568 
569     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
570     return hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
571 }
572 
573 static void acl_handler(uint8_t *packet, int size){
574 
575     // log_info("acl_handler: size %u", size);
576 
577     // get info
578     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
579     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
580     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
581     uint16_t acl_length         = READ_ACL_LENGTH(packet);
582 
583     // ignore non-registered handle
584     if (!conn){
585         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
586         return;
587     }
588 
589     // assert packet is complete
590     if (acl_length + 4 != size){
591         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
592         return;
593     }
594 
595     // update idle timestamp
596     hci_connection_timestamp(conn);
597 
598     // handle different packet types
599     switch (acl_flags & 0x03) {
600 
601         case 0x01: // continuation fragment
602 
603             // sanity checks
604             if (conn->acl_recombination_pos == 0) {
605                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
606                 return;
607             }
608             if (conn->acl_recombination_pos + acl_length > 4 + HCI_ACL_BUFFER_SIZE){
609                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
610                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
611                 conn->acl_recombination_pos = 0;
612                 return;
613             }
614 
615             // append fragment payload (header already stored)
616             memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos], &packet[4], acl_length );
617             conn->acl_recombination_pos += acl_length;
618 
619             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
620             //        conn->acl_recombination_pos, conn->acl_recombination_length);
621 
622             // forward complete L2CAP packet if complete.
623             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
624 
625                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, &conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
626                 // reset recombination buffer
627                 conn->acl_recombination_length = 0;
628                 conn->acl_recombination_pos = 0;
629             }
630             break;
631 
632         case 0x02: { // first fragment
633 
634             // sanity check
635             if (conn->acl_recombination_pos) {
636                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
637                 conn->acl_recombination_pos = 0;
638             }
639 
640             // peek into L2CAP packet!
641             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
642 
643             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
644 
645             // compare fragment size to L2CAP packet size
646             if (acl_length >= l2cap_length + 4){
647 
648                 // forward fragment as L2CAP packet
649                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
650 
651             } else {
652 
653                 if (acl_length > HCI_ACL_BUFFER_SIZE){
654                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
655                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
656                     return;
657                 }
658 
659                 // store first fragment and tweak acl length for complete package
660                 memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], packet, acl_length + 4);
661                 conn->acl_recombination_pos    = acl_length + 4;
662                 conn->acl_recombination_length = l2cap_length;
663                 bt_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2, l2cap_length +4);
664             }
665             break;
666 
667         }
668         default:
669             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
670             return;
671     }
672 
673     // execute main loop
674     hci_run();
675 }
676 
677 static void hci_shutdown_connection(hci_connection_t *conn){
678     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
679 
680     run_loop_remove_timer(&conn->timeout);
681 
682     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
683     btstack_memory_hci_connection_free( conn );
684 
685     // now it's gone
686     hci_emit_nr_connections_changed();
687 }
688 
689 static const uint16_t packet_type_sizes[] = {
690     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
691     HCI_ACL_DH1_SIZE, 0, 0, 0,
692     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
693     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
694 };
695 static const uint8_t  packet_type_feature_requirement_bit[] = {
696      0, // 3 slot packets
697      1, // 5 slot packets
698     25, // EDR 2 mpbs
699     26, // EDR 3 mbps
700     39, // 3 slot EDR packts
701     40, // 5 slot EDR packet
702 };
703 static const uint16_t packet_type_feature_packet_mask[] = {
704     0x0f00, // 3 slot packets
705     0xf000, // 5 slot packets
706     0x1102, // EDR 2 mpbs
707     0x2204, // EDR 3 mbps
708     0x0300, // 3 slot EDR packts
709     0x3000, // 5 slot EDR packet
710 };
711 
712 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
713     // enable packet types based on size
714     uint16_t packet_types = 0;
715     unsigned int i;
716     for (i=0;i<16;i++){
717         if (packet_type_sizes[i] == 0) continue;
718         if (packet_type_sizes[i] <= buffer_size){
719             packet_types |= 1 << i;
720         }
721     }
722     // disable packet types due to missing local supported features
723     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
724         int bit_idx = packet_type_feature_requirement_bit[i];
725         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
726         if (feature_set) continue;
727         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
728         packet_types &= ~packet_type_feature_packet_mask[i];
729     }
730     // flip bits for "may not be used"
731     packet_types ^= 0x3306;
732     return packet_types;
733 }
734 
735 uint16_t hci_usable_acl_packet_types(void){
736     return hci_stack->packet_types;
737 }
738 
739 uint8_t* hci_get_outgoing_packet_buffer(void){
740     // hci packet buffer is >= acl data packet length
741     return hci_stack->hci_packet_buffer;
742 }
743 
744 uint16_t hci_max_acl_data_packet_length(void){
745     return hci_stack->acl_data_packet_length;
746 }
747 
748 int hci_non_flushable_packet_boundary_flag_supported(void){
749     // No. 54, byte 6, bit 6
750     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
751 }
752 
753 int hci_ssp_supported(void){
754     // No. 51, byte 6, bit 3
755     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
756 }
757 
758 int hci_classic_supported(void){
759     // No. 37, byte 4, bit 5, = No BR/EDR Support
760     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
761 }
762 
763 int hci_le_supported(void){
764 #ifdef HAVE_BLE
765     // No. 37, byte 4, bit 6 = LE Supported (Controller)
766     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
767 #else
768     return 0;
769 #endif
770 }
771 
772 // get addr type and address used in advertisement packets
773 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
774     *addr_type = hci_stack->adv_addr_type;
775     if (hci_stack->adv_addr_type){
776         memcpy(addr, hci_stack->adv_address, 6);
777     } else {
778         memcpy(addr, hci_stack->local_bd_addr, 6);
779     }
780 }
781 
782 #ifdef HAVE_BLE
783 void le_handle_advertisement_report(uint8_t *packet, int size){
784     int offset = 3;
785     int num_reports = packet[offset];
786     offset += 1;
787 
788     int i;
789     log_info("HCI: handle adv report with num reports: %d", num_reports);
790     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
791     for (i=0; i<num_reports;i++){
792         uint8_t data_length = packet[offset + 8];
793         uint8_t event_size = 10 + data_length;
794         int pos = 0;
795         event[pos++] = GAP_LE_ADVERTISING_REPORT;
796         event[pos++] = event_size;
797         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
798         offset += 8;
799         pos += 8;
800         event[pos++] = packet[offset + 1 + data_length]; // rssi
801         event[pos++] = packet[offset++]; //data_length;
802         memcpy(&event[pos], &packet[offset], data_length);
803         pos += data_length;
804         offset += data_length + 1; // rssi
805         hci_dump_packet( HCI_EVENT_PACKET, 0, event, pos);
806         hci_stack->packet_handler(HCI_EVENT_PACKET, event, pos);
807     }
808 }
809 #endif
810 
811 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
812     uint8_t command_completed = 0;
813     if ((hci_stack->substate % 2) == 0) return;
814     // odd: waiting for event
815     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
816         uint16_t opcode = READ_BT_16(packet,3);
817         if (opcode == hci_stack->last_cmd_opcode){
818             command_completed = 1;
819             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate >> 1);
820         } else {
821             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
822         }
823     }
824     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
825         uint8_t  status = packet[2];
826         uint16_t opcode = READ_BT_16(packet,4);
827         if (opcode == hci_stack->last_cmd_opcode){
828             if (status){
829                 command_completed = 1;
830                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate >> 1);
831             } else {
832                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
833             }
834         } else {
835             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
836         }
837     }
838 
839     if (!command_completed) return;
840 
841     switch(hci_stack->substate >> 1){
842         default:
843             hci_stack->substate++;
844             break;
845     }
846 }
847 
848 static void hci_initializing_state_machine(){
849     if (hci_stack->substate % 2) {
850         // odd: waiting for command completion
851         return;
852     }
853     // log_info("hci_init: substate %u", hci_stack->substate >> 1);
854     switch (hci_stack->substate >> 1){
855         case 0: // RESET
856             hci_state_reset();
857 
858             hci_send_cmd(&hci_reset);
859             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
860                 // skip baud change
861                 hci_stack->substate = 2 << 1;
862             }
863             break;
864         case 1: // SEND BAUD CHANGE
865             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
866             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
867             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
868             break;
869         case 2: // LOCAL BAUD CHANGE
870             log_info("Local baud rate change");
871             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
872             hci_stack->substate += 2;
873             // break missing here for fall through
874 
875         case 3: // SET BD ADDR
876             if ( hci_stack->custom_bd_addr_set && hci_stack->control && hci_stack->control->set_bd_addr_cmd){
877                 log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
878                 hci_stack->control->set_bd_addr_cmd(hci_stack->config, hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
879                 hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
880                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
881                 break;
882             }
883             hci_stack->substate += 2;
884             // break missing here for fall through
885 
886         case 4:
887             log_info("Custom init");
888             // Custom initialization
889             if (hci_stack->control && hci_stack->control->next_cmd){
890                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
891                 if (valid_cmd){
892                     int size = 3 + hci_stack->hci_packet_buffer[2];
893                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
894                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
895                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
896                     hci_stack->substate = 3 << 1; // more init commands
897                     break;
898                 }
899                 log_info("hci_run: init script done");
900             }
901             // otherwise continue
902             hci_send_cmd(&hci_read_bd_addr);
903             break;
904         case 5:
905             hci_send_cmd(&hci_read_buffer_size);
906             break;
907         case 6:
908             hci_send_cmd(&hci_read_local_supported_features);
909             break;
910         case 7:
911             if (hci_le_supported()){
912                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
913             } else {
914                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
915                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
916             }
917 
918             // skip Classic init commands for LE only chipsets
919             if (!hci_classic_supported()){
920                 if (hci_le_supported()){
921                     hci_stack->substate = 12 << 1;    // skip all classic command
922                 } else {
923                     log_error("Neither BR/EDR nor LE supported");
924                     hci_stack->substate = 15 << 1;    // skip all
925                 }
926             }
927             break;
928         case 8:
929             if (hci_ssp_supported()){
930                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
931                 break;
932             }
933             hci_stack->substate += 2;
934             // break missing here for fall through
935 
936         case 9:
937             // ca. 15 sec
938             hci_send_cmd(&hci_write_page_timeout, 0x6000);
939             break;
940         case 10:
941             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
942             break;
943         case 11:
944             if (hci_stack->local_name){
945                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
946             } else {
947                 char hostname[30];
948 #ifdef EMBEDDED
949                 // BTstack-11:22:33:44:55:66
950                 strcpy(hostname, "BTstack ");
951                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
952                 log_info("---> Name %s", hostname);
953 #else
954                 // hostname for POSIX systems
955                 gethostname(hostname, 30);
956                 hostname[29] = '\0';
957 #endif
958                 hci_send_cmd(&hci_write_local_name, hostname);
959             }
960             break;
961         case 12:
962             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
963             if (!hci_le_supported()){
964                 // SKIP LE init for Classic only configuration
965                 hci_stack->substate = 15 << 1;
966             }
967             break;
968 
969 #ifdef HAVE_BLE
970         // LE INIT
971         case 13:
972             hci_send_cmd(&hci_le_read_buffer_size);
973             break;
974         case 14:
975             // LE Supported Host = 1, Simultaneous Host = 0
976             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
977             break;
978         case 15:
979             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
980             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
981             break;
982 #endif
983 
984         // DONE
985         case 16:
986             // done.
987             hci_stack->state = HCI_STATE_WORKING;
988             hci_emit_state();
989             break;
990         default:
991             break;
992     }
993     hci_stack->substate++;
994 }
995 
996 // avoid huge local variables
997 #ifndef EMBEDDED
998 static device_name_t device_name;
999 #endif
1000 static void event_handler(uint8_t *packet, int size){
1001 
1002     uint16_t event_length = packet[1];
1003 
1004     // assert packet is complete
1005     if (size != event_length + 2){
1006         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
1007         return;
1008     }
1009 
1010     bd_addr_t addr;
1011     bd_addr_type_t addr_type;
1012     uint8_t link_type;
1013     hci_con_handle_t handle;
1014     hci_connection_t * conn;
1015     int i;
1016 
1017     // log_info("HCI:EVENT:%02x", packet[0]);
1018 
1019     switch (packet[0]) {
1020 
1021         case HCI_EVENT_COMMAND_COMPLETE:
1022             // get num cmd packets
1023             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
1024             hci_stack->num_cmd_packets = packet[2];
1025 
1026             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
1027                 // from offset 5
1028                 // status
1029                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
1030                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
1031                 hci_stack->sco_data_packet_length = packet[8];
1032                 hci_stack->acl_packets_total_num  = packet[9];
1033                 hci_stack->sco_packets_total_num  = packet[10];
1034 
1035                 if (hci_stack->state == HCI_STATE_INITIALIZING){
1036                     // determine usable ACL payload size
1037                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
1038                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1039                     }
1040                     log_info("hci_read_buffer_size: used size %u, count %u",
1041                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num);
1042                 }
1043             }
1044 #ifdef HAVE_BLE
1045             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
1046                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
1047                 hci_stack->le_acl_packets_total_num  = packet[8];
1048                     // determine usable ACL payload size
1049                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
1050                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
1051                     }
1052                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
1053             }
1054 #endif
1055             // Dump local address
1056             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
1057                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
1058                 log_info("Local Address, Status: 0x%02x: Addr: %s",
1059                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
1060             }
1061             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1062                 hci_emit_discoverable_enabled(hci_stack->discoverable);
1063             }
1064             // Note: HCI init checks
1065             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
1066                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
1067                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
1068                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
1069                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
1070                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
1071                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
1072 
1073                 // determine usable ACL packet types based on host buffer size and supported features
1074                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
1075                 log_info("packet types %04x", hci_stack->packet_types);
1076 
1077                 // Classic/LE
1078                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
1079             }
1080             break;
1081 
1082         case HCI_EVENT_COMMAND_STATUS:
1083             // get num cmd packets
1084             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
1085             hci_stack->num_cmd_packets = packet[3];
1086             break;
1087 
1088         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
1089             int offset = 3;
1090             for (i=0; i<packet[2];i++){
1091                 handle = READ_BT_16(packet, offset);
1092                 offset += 2;
1093                 uint16_t num_packets = READ_BT_16(packet, offset);
1094                 offset += 2;
1095 
1096                 conn = hci_connection_for_handle(handle);
1097                 if (!conn){
1098                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
1099                     continue;
1100                 }
1101 
1102                 if (conn->address_type == BD_ADDR_TYPE_SCO){
1103                     if (conn->num_sco_packets_sent >= num_packets){
1104                         conn->num_sco_packets_sent -= num_packets;
1105                     } else {
1106                         log_error("hci_number_completed_packets, more sco slots freed then sent.");
1107                         conn->num_sco_packets_sent = 0;
1108                     }
1109 
1110                 } else {
1111                     if (conn->num_acl_packets_sent >= num_packets){
1112                         conn->num_acl_packets_sent -= num_packets;
1113                     } else {
1114                         log_error("hci_number_completed_packets, more acl slots freed then sent.");
1115                         conn->num_acl_packets_sent = 0;
1116                     }
1117                 }
1118                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1119             }
1120             break;
1121         }
1122         case HCI_EVENT_CONNECTION_REQUEST:
1123             bt_flip_addr(addr, &packet[2]);
1124             // TODO: eval COD 8-10
1125             link_type = packet[11];
1126             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1127             addr_type = link_type == 1 ? BD_ADDR_TYPE_CLASSIC : BD_ADDR_TYPE_SCO;
1128             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1129             if (!conn) {
1130                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1131             }
1132             if (!conn) {
1133                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1134                 hci_stack->decline_reason = 0x0d;
1135                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1136                 break;
1137             }
1138             conn->state = RECEIVED_CONNECTION_REQUEST;
1139             hci_run();
1140             break;
1141 
1142         case HCI_EVENT_CONNECTION_COMPLETE:
1143             // Connection management
1144             bt_flip_addr(addr, &packet[5]);
1145             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1146             addr_type = BD_ADDR_TYPE_CLASSIC;
1147             conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1148             if (conn) {
1149                 if (!packet[2]){
1150                     conn->state = OPEN;
1151                     conn->con_handle = READ_BT_16(packet, 3);
1152                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1153 
1154                     // restart timer
1155                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1156                     run_loop_add_timer(&conn->timeout);
1157 
1158                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1159 
1160                     hci_emit_nr_connections_changed();
1161                 } else {
1162                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1163                     uint8_t status = packet[2];
1164                     bd_addr_t bd_address;
1165                     memcpy(&bd_address, conn->address, 6);
1166 
1167                     // connection failed, remove entry
1168                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1169                     btstack_memory_hci_connection_free( conn );
1170 
1171                     // notify client if dedicated bonding
1172                     if (notify_dedicated_bonding_failed){
1173                         log_info("hci notify_dedicated_bonding_failed");
1174                         hci_emit_dedicated_bonding_result(bd_address, status);
1175                     }
1176 
1177                     // if authentication error, also delete link key
1178                     if (packet[2] == 0x05) {
1179                         hci_drop_link_key_for_bd_addr(&addr);
1180                     }
1181                 }
1182             }
1183             break;
1184 
1185         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
1186             bt_flip_addr(addr, &packet[5]);
1187             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1188             if (!packet[2]){
1189                 // connection failed
1190                 break;
1191             }
1192             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_SCO);
1193             if (!conn) {
1194                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
1195             }
1196             if (!conn) {
1197                 break;
1198             }
1199             break;
1200 
1201         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1202             handle = READ_BT_16(packet, 3);
1203             conn = hci_connection_for_handle(handle);
1204             if (!conn) break;
1205             if (!packet[2]){
1206                 uint8_t * features = &packet[5];
1207                 if (features[6] & (1 << 3)){
1208                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1209                 }
1210             }
1211             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1212             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1213             if (conn->bonding_flags & BONDING_DEDICATED){
1214                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1215             }
1216             break;
1217 
1218         case HCI_EVENT_LINK_KEY_REQUEST:
1219             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1220             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1221             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1222             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1223             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1224             hci_run();
1225             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1226             return;
1227 
1228         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1229             bt_flip_addr(addr, &packet[2]);
1230             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1231             if (!conn) break;
1232             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1233             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1234             // Change Connection Encryption keeps link key type
1235             if (link_key_type != CHANGED_COMBINATION_KEY){
1236                 conn->link_key_type = link_key_type;
1237             }
1238             if (!hci_stack->remote_device_db) break;
1239             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
1240             // still forward event to allow dismiss of pairing dialog
1241             break;
1242         }
1243 
1244         case HCI_EVENT_PIN_CODE_REQUEST:
1245             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1246             // non-bondable mode: pin code negative reply will be sent
1247             if (!hci_stack->bondable){
1248                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1249                 hci_run();
1250                 return;
1251             }
1252             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1253             if (!hci_stack->remote_device_db) break;
1254             bt_flip_addr(addr, &packet[2]);
1255             hci_stack->remote_device_db->delete_link_key(&addr);
1256             break;
1257 
1258         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1259             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1260             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1261             break;
1262 
1263         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1264             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1265             if (!hci_stack->ssp_auto_accept) break;
1266             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1267             break;
1268 
1269         case HCI_EVENT_USER_PASSKEY_REQUEST:
1270             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1271             if (!hci_stack->ssp_auto_accept) break;
1272             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1273             break;
1274 
1275         case HCI_EVENT_ENCRYPTION_CHANGE:
1276             handle = READ_BT_16(packet, 3);
1277             conn = hci_connection_for_handle(handle);
1278             if (!conn) break;
1279             if (packet[2] == 0) {
1280                 if (packet[5]){
1281                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1282                 } else {
1283                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1284                 }
1285             }
1286             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1287             break;
1288 
1289         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1290             handle = READ_BT_16(packet, 3);
1291             conn = hci_connection_for_handle(handle);
1292             if (!conn) break;
1293 
1294             // dedicated bonding: send result and disconnect
1295             if (conn->bonding_flags & BONDING_DEDICATED){
1296                 conn->bonding_flags &= ~BONDING_DEDICATED;
1297                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1298                 conn->bonding_status = packet[2];
1299                 break;
1300             }
1301 
1302             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1303                 // link key sufficient for requested security
1304                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1305                 break;
1306             }
1307             // not enough
1308             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1309             break;
1310 
1311 #ifndef EMBEDDED
1312         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1313             if (!hci_stack->remote_device_db) break;
1314             if (packet[2]) break; // status not ok
1315             bt_flip_addr(addr, &packet[3]);
1316             // fix for invalid remote names - terminate on 0xff
1317             for (i=0; i<248;i++){
1318                 if (packet[9+i] == 0xff){
1319                     packet[9+i] = 0;
1320                     break;
1321                 }
1322             }
1323             memset(&device_name, 0, sizeof(device_name_t));
1324             strncpy((char*) device_name, (char*) &packet[9], 248);
1325             hci_stack->remote_device_db->put_name(&addr, &device_name);
1326             break;
1327 
1328         case HCI_EVENT_INQUIRY_RESULT:
1329         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1330             if (!hci_stack->remote_device_db) break;
1331             // first send inq result packet
1332             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1333             // then send cached remote names
1334             int offset = 3;
1335             for (i=0; i<packet[2];i++){
1336                 bt_flip_addr(addr, &packet[offset]);
1337                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1338                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
1339                     hci_emit_remote_name_cached(&addr, &device_name);
1340                 }
1341             }
1342             return;
1343         }
1344 #endif
1345 
1346         // HCI_EVENT_DISCONNECTION_COMPLETE
1347         // has been split, to first notify stack before shutting connection down
1348         // see end of function, too.
1349         case HCI_EVENT_DISCONNECTION_COMPLETE:
1350             if (packet[2]) break;   // status != 0
1351             handle = READ_BT_16(packet, 3);
1352             hci_connection_t * conn = hci_connection_for_handle(handle);
1353             if (!conn) break;       // no conn struct anymore
1354             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
1355             break;
1356 
1357         case HCI_EVENT_HARDWARE_ERROR:
1358             if(hci_stack->control && hci_stack->control->hw_error){
1359                 (*hci_stack->control->hw_error)();
1360             } else {
1361                 // if no special requests, just reboot stack
1362                 hci_power_control_off();
1363                 hci_power_control_on();
1364             }
1365             break;
1366 
1367         case DAEMON_EVENT_HCI_PACKET_SENT:
1368             // release packet buffer only for asynchronous transport and if there are not further fragements
1369             if (hci_transport_synchronous()) {
1370                 log_error("Synchronous HCI Transport shouldn't send DAEMON_EVENT_HCI_PACKET_SENT");
1371                 return; // instead of break: to avoid re-entering hci_run()
1372             }
1373             if (hci_stack->acl_fragmentation_total_size) break;
1374             hci_release_packet_buffer();
1375             break;
1376 
1377 #ifdef HAVE_BLE
1378         case HCI_EVENT_LE_META:
1379             switch (packet[2]){
1380                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1381                     log_info("advertising report received");
1382                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1383                     le_handle_advertisement_report(packet, size);
1384                     break;
1385                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1386                     // Connection management
1387                     bt_flip_addr(addr, &packet[8]);
1388                     addr_type = (bd_addr_type_t)packet[7];
1389                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1390                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1391                     conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1392                     if (packet[3]){
1393                         if (conn){
1394                             // outgoing connection failed, remove entry
1395                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1396                             btstack_memory_hci_connection_free( conn );
1397                         }
1398                         // if authentication error, also delete link key
1399                         if (packet[3] == 0x05) {
1400                             hci_drop_link_key_for_bd_addr(&addr);
1401                         }
1402                         break;
1403                     }
1404                     if (!conn){
1405                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1406                     }
1407                     if (!conn){
1408                         // no memory
1409                         break;
1410                     }
1411 
1412                     conn->state = OPEN;
1413                     conn->con_handle = READ_BT_16(packet, 4);
1414 
1415                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1416 
1417                     // restart timer
1418                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1419                     // run_loop_add_timer(&conn->timeout);
1420 
1421                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1422 
1423                     hci_emit_nr_connections_changed();
1424                     break;
1425 
1426             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1427 
1428                 default:
1429                     break;
1430             }
1431             break;
1432 #endif
1433         default:
1434             break;
1435     }
1436 
1437     // handle BT initialization
1438     if (hci_stack->state == HCI_STATE_INITIALIZING){
1439         hci_initializing_event_handler(packet, size);
1440     }
1441 
1442     // help with BT sleep
1443     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1444         && hci_stack->substate == 1
1445         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1446         hci_stack->substate++;
1447     }
1448 
1449     // notify upper stack
1450     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1451 
1452     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1453     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1454         if (!packet[2]){
1455             handle = READ_BT_16(packet, 3);
1456             hci_connection_t * conn = hci_connection_for_handle(handle);
1457             if (conn) {
1458                 uint8_t status = conn->bonding_status;
1459                 uint16_t flags = conn->bonding_flags;
1460                 bd_addr_t bd_address;
1461                 memcpy(&bd_address, conn->address, 6);
1462                 hci_shutdown_connection(conn);
1463                 // connection struct is gone, don't access anymore
1464                 if (flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1465                     hci_emit_dedicated_bonding_result(bd_address, status);
1466                 }
1467             }
1468         }
1469     }
1470 
1471 	// execute main loop
1472 	hci_run();
1473 }
1474 
1475 static void sco_handler(uint8_t * packet, uint16_t size){
1476     // not handled yet
1477 }
1478 
1479 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1480     hci_dump_packet(packet_type, 1, packet, size);
1481     switch (packet_type) {
1482         case HCI_EVENT_PACKET:
1483             event_handler(packet, size);
1484             break;
1485         case HCI_ACL_DATA_PACKET:
1486             acl_handler(packet, size);
1487             break;
1488         case HCI_SCO_DATA_PACKET:
1489             sco_handler(packet, size);
1490         default:
1491             break;
1492     }
1493 }
1494 
1495 /** Register HCI packet handlers */
1496 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1497     hci_stack->packet_handler = handler;
1498 }
1499 
1500 static void hci_state_reset(){
1501     // no connections yet
1502     hci_stack->connections = NULL;
1503 
1504     // keep discoverable/connectable as this has been requested by the client(s)
1505     // hci_stack->discoverable = 0;
1506     // hci_stack->connectable = 0;
1507     // hci_stack->bondable = 1;
1508 
1509     // buffer is free
1510     hci_stack->hci_packet_buffer_reserved = 0;
1511 
1512     // no pending cmds
1513     hci_stack->decline_reason = 0;
1514     hci_stack->new_scan_enable_value = 0xff;
1515 
1516     // LE
1517     hci_stack->adv_addr_type = 0;
1518     memset(hci_stack->adv_address, 0, 6);
1519     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1520     hci_stack->le_scan_type = 0xff;
1521     hci_stack->le_connection_parameter_range.le_conn_interval_min = 0x0006;
1522     hci_stack->le_connection_parameter_range.le_conn_interval_max = 0x0C80;
1523     hci_stack->le_connection_parameter_range.le_conn_latency_min = 0x0000;
1524     hci_stack->le_connection_parameter_range.le_conn_latency_max = 0x03E8;
1525     hci_stack->le_connection_parameter_range.le_supervision_timeout_min = 0x000A;
1526     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 0x0C80;
1527 }
1528 
1529 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1530 
1531 #ifdef HAVE_MALLOC
1532     if (!hci_stack) {
1533         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1534     }
1535 #else
1536     hci_stack = &hci_stack_static;
1537 #endif
1538     memset(hci_stack, 0, sizeof(hci_stack_t));
1539 
1540     // reference to use transport layer implementation
1541     hci_stack->hci_transport = transport;
1542 
1543     // references to used control implementation
1544     hci_stack->control = control;
1545 
1546     // reference to used config
1547     hci_stack->config = config;
1548 
1549     // higher level handler
1550     hci_stack->packet_handler = dummy_handler;
1551 
1552     // store and open remote device db
1553     hci_stack->remote_device_db = remote_device_db;
1554     if (hci_stack->remote_device_db) {
1555         hci_stack->remote_device_db->open();
1556     }
1557 
1558     // max acl payload size defined in config.h
1559     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1560 
1561     // register packet handlers with transport
1562     transport->register_packet_handler(&packet_handler);
1563 
1564     hci_stack->state = HCI_STATE_OFF;
1565 
1566     // class of device
1567     hci_stack->class_of_device = 0x007a020c; // Smartphone
1568 
1569     // bondable by default
1570     hci_stack->bondable = 1;
1571 
1572     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1573     hci_stack->ssp_enable = 1;
1574     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1575     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1576     hci_stack->ssp_auto_accept = 1;
1577 
1578     hci_state_reset();
1579 }
1580 
1581 void hci_close(){
1582     // close remote device db
1583     if (hci_stack->remote_device_db) {
1584         hci_stack->remote_device_db->close();
1585     }
1586     while (hci_stack->connections) {
1587         // cancel all l2cap connections
1588         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1589         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1590     }
1591     hci_power_control(HCI_POWER_OFF);
1592 
1593 #ifdef HAVE_MALLOC
1594     free(hci_stack);
1595 #endif
1596     hci_stack = NULL;
1597 }
1598 
1599 void hci_set_class_of_device(uint32_t class_of_device){
1600     hci_stack->class_of_device = class_of_device;
1601 }
1602 
1603 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
1604 void hci_set_bd_addr(bd_addr_t addr){
1605     memcpy(hci_stack->custom_bd_addr, addr, 6);
1606     hci_stack->custom_bd_addr_set = 1;
1607 }
1608 
1609 void hci_disable_l2cap_timeout_check(){
1610     disable_l2cap_timeouts = 1;
1611 }
1612 // State-Module-Driver overview
1613 // state                    module  low-level
1614 // HCI_STATE_OFF             off      close
1615 // HCI_STATE_INITIALIZING,   on       open
1616 // HCI_STATE_WORKING,        on       open
1617 // HCI_STATE_HALTING,        on       open
1618 // HCI_STATE_SLEEPING,    off/sleep   close
1619 // HCI_STATE_FALLING_ASLEEP  on       open
1620 
1621 static int hci_power_control_on(void){
1622 
1623     // power on
1624     int err = 0;
1625     if (hci_stack->control && hci_stack->control->on){
1626         err = (*hci_stack->control->on)(hci_stack->config);
1627     }
1628     if (err){
1629         log_error( "POWER_ON failed");
1630         hci_emit_hci_open_failed();
1631         return err;
1632     }
1633 
1634     // open low-level device
1635     err = hci_stack->hci_transport->open(hci_stack->config);
1636     if (err){
1637         log_error( "HCI_INIT failed, turning Bluetooth off again");
1638         if (hci_stack->control && hci_stack->control->off){
1639             (*hci_stack->control->off)(hci_stack->config);
1640         }
1641         hci_emit_hci_open_failed();
1642         return err;
1643     }
1644     return 0;
1645 }
1646 
1647 static void hci_power_control_off(void){
1648 
1649     log_info("hci_power_control_off");
1650 
1651     // close low-level device
1652     hci_stack->hci_transport->close(hci_stack->config);
1653 
1654     log_info("hci_power_control_off - hci_transport closed");
1655 
1656     // power off
1657     if (hci_stack->control && hci_stack->control->off){
1658         (*hci_stack->control->off)(hci_stack->config);
1659     }
1660 
1661     log_info("hci_power_control_off - control closed");
1662 
1663     hci_stack->state = HCI_STATE_OFF;
1664 }
1665 
1666 static void hci_power_control_sleep(void){
1667 
1668     log_info("hci_power_control_sleep");
1669 
1670 #if 0
1671     // don't close serial port during sleep
1672 
1673     // close low-level device
1674     hci_stack->hci_transport->close(hci_stack->config);
1675 #endif
1676 
1677     // sleep mode
1678     if (hci_stack->control && hci_stack->control->sleep){
1679         (*hci_stack->control->sleep)(hci_stack->config);
1680     }
1681 
1682     hci_stack->state = HCI_STATE_SLEEPING;
1683 }
1684 
1685 static int hci_power_control_wake(void){
1686 
1687     log_info("hci_power_control_wake");
1688 
1689     // wake on
1690     if (hci_stack->control && hci_stack->control->wake){
1691         (*hci_stack->control->wake)(hci_stack->config);
1692     }
1693 
1694 #if 0
1695     // open low-level device
1696     int err = hci_stack->hci_transport->open(hci_stack->config);
1697     if (err){
1698         log_error( "HCI_INIT failed, turning Bluetooth off again");
1699         if (hci_stack->control && hci_stack->control->off){
1700             (*hci_stack->control->off)(hci_stack->config);
1701         }
1702         hci_emit_hci_open_failed();
1703         return err;
1704     }
1705 #endif
1706 
1707     return 0;
1708 }
1709 
1710 static void hci_power_transition_to_initializing(void){
1711     // set up state machine
1712     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1713     hci_stack->hci_packet_buffer_reserved = 0;
1714     hci_stack->state = HCI_STATE_INITIALIZING;
1715     hci_stack->substate = 0;
1716 }
1717 
1718 int hci_power_control(HCI_POWER_MODE power_mode){
1719 
1720     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1721 
1722     int err = 0;
1723     switch (hci_stack->state){
1724 
1725         case HCI_STATE_OFF:
1726             switch (power_mode){
1727                 case HCI_POWER_ON:
1728                     err = hci_power_control_on();
1729                     if (err) {
1730                         log_error("hci_power_control_on() error %u", err);
1731                         return err;
1732                     }
1733                     hci_power_transition_to_initializing();
1734                     break;
1735                 case HCI_POWER_OFF:
1736                     // do nothing
1737                     break;
1738                 case HCI_POWER_SLEEP:
1739                     // do nothing (with SLEEP == OFF)
1740                     break;
1741             }
1742             break;
1743 
1744         case HCI_STATE_INITIALIZING:
1745             switch (power_mode){
1746                 case HCI_POWER_ON:
1747                     // do nothing
1748                     break;
1749                 case HCI_POWER_OFF:
1750                     // no connections yet, just turn it off
1751                     hci_power_control_off();
1752                     break;
1753                 case HCI_POWER_SLEEP:
1754                     // no connections yet, just turn it off
1755                     hci_power_control_sleep();
1756                     break;
1757             }
1758             break;
1759 
1760         case HCI_STATE_WORKING:
1761             switch (power_mode){
1762                 case HCI_POWER_ON:
1763                     // do nothing
1764                     break;
1765                 case HCI_POWER_OFF:
1766                     // see hci_run
1767                     hci_stack->state = HCI_STATE_HALTING;
1768                     break;
1769                 case HCI_POWER_SLEEP:
1770                     // see hci_run
1771                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1772                     hci_stack->substate = 0;
1773                     break;
1774             }
1775             break;
1776 
1777         case HCI_STATE_HALTING:
1778             switch (power_mode){
1779                 case HCI_POWER_ON:
1780                     hci_power_transition_to_initializing();
1781                     break;
1782                 case HCI_POWER_OFF:
1783                     // do nothing
1784                     break;
1785                 case HCI_POWER_SLEEP:
1786                     // see hci_run
1787                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1788                     hci_stack->substate = 0;
1789                     break;
1790             }
1791             break;
1792 
1793         case HCI_STATE_FALLING_ASLEEP:
1794             switch (power_mode){
1795                 case HCI_POWER_ON:
1796 
1797 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1798                     // nothing to do, if H4 supports power management
1799                     if (bt_control_iphone_power_management_enabled()){
1800                         hci_stack->state = HCI_STATE_INITIALIZING;
1801                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1802                         break;
1803                     }
1804 #endif
1805                     hci_power_transition_to_initializing();
1806                     break;
1807                 case HCI_POWER_OFF:
1808                     // see hci_run
1809                     hci_stack->state = HCI_STATE_HALTING;
1810                     break;
1811                 case HCI_POWER_SLEEP:
1812                     // do nothing
1813                     break;
1814             }
1815             break;
1816 
1817         case HCI_STATE_SLEEPING:
1818             switch (power_mode){
1819                 case HCI_POWER_ON:
1820 
1821 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1822                     // nothing to do, if H4 supports power management
1823                     if (bt_control_iphone_power_management_enabled()){
1824                         hci_stack->state = HCI_STATE_INITIALIZING;
1825                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1826                         hci_update_scan_enable();
1827                         break;
1828                     }
1829 #endif
1830                     err = hci_power_control_wake();
1831                     if (err) return err;
1832                     hci_power_transition_to_initializing();
1833                     break;
1834                 case HCI_POWER_OFF:
1835                     hci_stack->state = HCI_STATE_HALTING;
1836                     break;
1837                 case HCI_POWER_SLEEP:
1838                     // do nothing
1839                     break;
1840             }
1841             break;
1842     }
1843 
1844     // create internal event
1845 	hci_emit_state();
1846 
1847 	// trigger next/first action
1848 	hci_run();
1849 
1850     return 0;
1851 }
1852 
1853 static void hci_update_scan_enable(void){
1854     // 2 = page scan, 1 = inq scan
1855     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1856     hci_run();
1857 }
1858 
1859 void hci_discoverable_control(uint8_t enable){
1860     if (enable) enable = 1; // normalize argument
1861 
1862     if (hci_stack->discoverable == enable){
1863         hci_emit_discoverable_enabled(hci_stack->discoverable);
1864         return;
1865     }
1866 
1867     hci_stack->discoverable = enable;
1868     hci_update_scan_enable();
1869 }
1870 
1871 void hci_connectable_control(uint8_t enable){
1872     if (enable) enable = 1; // normalize argument
1873 
1874     // don't emit event
1875     if (hci_stack->connectable == enable) return;
1876 
1877     hci_stack->connectable = enable;
1878     hci_update_scan_enable();
1879 }
1880 
1881 bd_addr_t * hci_local_bd_addr(void){
1882     return &hci_stack->local_bd_addr;
1883 }
1884 
1885 void hci_run(){
1886 
1887     hci_connection_t * connection;
1888     linked_item_t * it;
1889 
1890     // send continuation fragments first, as they block the prepared packet buffer
1891     if (hci_stack->acl_fragmentation_total_size > 0) {
1892         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1893         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1894             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1895             if (connection) {
1896                 hci_send_acl_packet_fragments(connection);
1897                 return;
1898             }
1899             // connection gone -> discard further fragments
1900             hci_stack->acl_fragmentation_total_size = 0;
1901             hci_stack->acl_fragmentation_pos = 0;
1902         }
1903     }
1904 
1905     if (!hci_can_send_command_packet_now()) return;
1906 
1907     // global/non-connection oriented commands
1908 
1909     // decline incoming connections
1910     if (hci_stack->decline_reason){
1911         uint8_t reason = hci_stack->decline_reason;
1912         hci_stack->decline_reason = 0;
1913         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1914         return;
1915     }
1916 
1917     // send scan enable
1918     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1919         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1920         hci_stack->new_scan_enable_value = 0xff;
1921         return;
1922     }
1923 
1924 #ifdef HAVE_BLE
1925     // handle le scan
1926     if (hci_stack->state == HCI_STATE_WORKING){
1927         switch(hci_stack->le_scanning_state){
1928             case LE_START_SCAN:
1929                 hci_stack->le_scanning_state = LE_SCANNING;
1930                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1931                 return;
1932 
1933             case LE_STOP_SCAN:
1934                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1935                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1936                 return;
1937             default:
1938                 break;
1939         }
1940         if (hci_stack->le_scan_type != 0xff){
1941             // defaults: active scanning, accept all advertisement packets
1942             int scan_type = hci_stack->le_scan_type;
1943             hci_stack->le_scan_type = 0xff;
1944             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);
1945             return;
1946         }
1947     }
1948 #endif
1949 
1950     // send pending HCI commands
1951     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1952         connection = (hci_connection_t *) it;
1953 
1954         switch(connection->state){
1955             case SEND_CREATE_CONNECTION:
1956                 switch(connection->address_type){
1957                     case BD_ADDR_TYPE_CLASSIC:
1958                         log_info("sending hci_create_connection");
1959                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1960                         break;
1961                     default:
1962 #ifdef HAVE_BLE
1963                         log_info("sending hci_le_create_connection");
1964                         hci_send_cmd(&hci_le_create_connection,
1965                                      0x0060,    // scan interval: 60 ms
1966                                      0x0030,    // scan interval: 30 ms
1967                                      0,         // don't use whitelist
1968                                      connection->address_type, // peer address type
1969                                      connection->address,      // peer bd addr
1970                                      hci_stack->adv_addr_type, // our addr type:
1971                                      0x0008,    // conn interval min
1972                                      0x0018,    // conn interval max
1973                                      0,         // conn latency
1974                                      0x0048,    // supervision timeout
1975                                      0x0001,    // min ce length
1976                                      0x0001     // max ce length
1977                                      );
1978 
1979                         connection->state = SENT_CREATE_CONNECTION;
1980 #endif
1981                         break;
1982                 }
1983                 return;
1984 
1985             case RECEIVED_CONNECTION_REQUEST:
1986                 log_info("sending hci_accept_connection_request");
1987                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1988                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
1989                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1990                 } else {
1991                     // TODO: allows to customize synchronous connection parameters
1992                     hci_send_cmd(&hci_accept_synchronous_connection_command, connection->address, 8000, 8000, 0xFFFF, 0x0060, 0xFF, 0x003F);
1993                 }
1994                 return;
1995 
1996 #ifdef HAVE_BLE
1997             case SEND_CANCEL_CONNECTION:
1998                 connection->state = SENT_CANCEL_CONNECTION;
1999                 hci_send_cmd(&hci_le_create_connection_cancel);
2000                 return;
2001 #endif
2002             case SEND_DISCONNECT:
2003                 connection->state = SENT_DISCONNECT;
2004                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
2005                 return;
2006 
2007             default:
2008                 break;
2009         }
2010 
2011         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
2012             log_info("responding to link key request");
2013             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
2014             link_key_t link_key;
2015             link_key_type_t link_key_type;
2016             if ( hci_stack->remote_device_db
2017               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
2018               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
2019                connection->link_key_type = link_key_type;
2020                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
2021             } else {
2022                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
2023             }
2024             return;
2025         }
2026 
2027         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
2028             log_info("denying to pin request");
2029             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
2030             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
2031             return;
2032         }
2033 
2034         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
2035             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
2036             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
2037             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
2038                 // tweak authentication requirements
2039                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
2040                 if (connection->bonding_flags & BONDING_DEDICATED){
2041                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2042                 }
2043                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
2044                     authreq |= 1;
2045                 }
2046                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
2047             } else {
2048                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
2049             }
2050             return;
2051         }
2052 
2053         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
2054             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
2055             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
2056             return;
2057         }
2058 
2059         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
2060             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
2061             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
2062             return;
2063         }
2064 
2065         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
2066             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
2067             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
2068             return;
2069         }
2070 
2071         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
2072             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
2073             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
2074             return;
2075         }
2076         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
2077             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
2078             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
2079             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
2080             return;
2081         }
2082         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
2083             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
2084             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
2085             return;
2086         }
2087         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
2088             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
2089             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
2090             return;
2091         }
2092 
2093 #ifdef HAVE_BLE
2094         if (connection->le_con_parameter_update_state == CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS){
2095             connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
2096 
2097             uint16_t connection_interval_min = connection->le_conn_interval_min;
2098             connection->le_conn_interval_min = 0;
2099             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
2100                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
2101                 0x0000, 0xffff);
2102         }
2103 #endif
2104     }
2105 
2106     switch (hci_stack->state){
2107         case HCI_STATE_INITIALIZING:
2108             hci_initializing_state_machine();
2109             break;
2110 
2111         case HCI_STATE_HALTING:
2112 
2113             log_info("HCI_STATE_HALTING");
2114             // close all open connections
2115             connection =  (hci_connection_t *) hci_stack->connections;
2116             if (connection){
2117 
2118                 // send disconnect
2119                 if (!hci_can_send_command_packet_now()) return;
2120 
2121                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2122                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2123 
2124                 // send disconnected event right away - causes higher layer connections to get closed, too.
2125                 hci_shutdown_connection(connection);
2126                 return;
2127             }
2128             log_info("HCI_STATE_HALTING, calling off");
2129 
2130             // switch mode
2131             hci_power_control_off();
2132 
2133             log_info("HCI_STATE_HALTING, emitting state");
2134             hci_emit_state();
2135             log_info("HCI_STATE_HALTING, done");
2136             break;
2137 
2138         case HCI_STATE_FALLING_ASLEEP:
2139             switch(hci_stack->substate) {
2140                 case 0:
2141                     log_info("HCI_STATE_FALLING_ASLEEP");
2142                     // close all open connections
2143                     connection =  (hci_connection_t *) hci_stack->connections;
2144 
2145 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2146                     // don't close connections, if H4 supports power management
2147                     if (bt_control_iphone_power_management_enabled()){
2148                         connection = NULL;
2149                     }
2150 #endif
2151                     if (connection){
2152 
2153                         // send disconnect
2154                         if (!hci_can_send_command_packet_now()) return;
2155 
2156                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
2157                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
2158 
2159                         // send disconnected event right away - causes higher layer connections to get closed, too.
2160                         hci_shutdown_connection(connection);
2161                         return;
2162                     }
2163 
2164                     if (hci_classic_supported()){
2165                         // disable page and inquiry scan
2166                         if (!hci_can_send_command_packet_now()) return;
2167 
2168                         log_info("HCI_STATE_HALTING, disabling inq scans");
2169                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2170 
2171                         // continue in next sub state
2172                         hci_stack->substate++;
2173                         break;
2174                     }
2175                     // fall through for ble-only chips
2176 
2177                 case 2:
2178                     log_info("HCI_STATE_HALTING, calling sleep");
2179 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2180                     // don't actually go to sleep, if H4 supports power management
2181                     if (bt_control_iphone_power_management_enabled()){
2182                         // SLEEP MODE reached
2183                         hci_stack->state = HCI_STATE_SLEEPING;
2184                         hci_emit_state();
2185                         break;
2186                     }
2187 #endif
2188                     // switch mode
2189                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2190                     hci_emit_state();
2191                     break;
2192 
2193                 default:
2194                     break;
2195             }
2196             break;
2197 
2198         default:
2199             break;
2200     }
2201 }
2202 
2203 int hci_send_cmd_packet(uint8_t *packet, int size){
2204     bd_addr_t addr;
2205     hci_connection_t * conn;
2206     // house-keeping
2207 
2208     // create_connection?
2209     if (IS_COMMAND(packet, hci_create_connection)){
2210         bt_flip_addr(addr, &packet[3]);
2211         log_info("Create_connection to %s", bd_addr_to_str(addr));
2212 
2213         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2214         if (!conn){
2215             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2216             if (!conn){
2217                 // notify client that alloc failed
2218                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2219                 return 0; // don't sent packet to controller
2220             }
2221             conn->state = SEND_CREATE_CONNECTION;
2222         }
2223         log_info("conn state %u", conn->state);
2224         switch (conn->state){
2225             // if connection active exists
2226             case OPEN:
2227                 // and OPEN, emit connection complete command, don't send to controller
2228                 hci_emit_connection_complete(conn, 0);
2229                 return 0;
2230             case SEND_CREATE_CONNECTION:
2231                 // connection created by hci, e.g. dedicated bonding
2232                 break;
2233             default:
2234                 // otherwise, just ignore as it is already in the open process
2235                 return 0;
2236         }
2237         conn->state = SENT_CREATE_CONNECTION;
2238     }
2239     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2240         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2241     }
2242     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2243         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2244     }
2245 
2246     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2247         if (hci_stack->remote_device_db){
2248             bt_flip_addr(addr, &packet[3]);
2249             hci_stack->remote_device_db->delete_link_key(&addr);
2250         }
2251     }
2252 
2253     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2254     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2255         bt_flip_addr(addr, &packet[3]);
2256         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2257         if (conn){
2258             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2259         }
2260     }
2261 
2262     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2263     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2264     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2265     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2266         bt_flip_addr(addr, &packet[3]);
2267         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2268         if (conn){
2269             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2270         }
2271     }
2272 
2273 #ifdef HAVE_BLE
2274     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2275         hci_stack->adv_addr_type = packet[8];
2276     }
2277     if (IS_COMMAND(packet, hci_le_set_random_address)){
2278         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2279     }
2280 #endif
2281 
2282     hci_stack->num_cmd_packets--;
2283 
2284     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
2285     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2286 
2287     // release packet buffer for synchronous transport implementations
2288     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2289         hci_stack->hci_packet_buffer_reserved = 0;
2290     }
2291 
2292     return err;
2293 }
2294 
2295 // disconnect because of security block
2296 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2297     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2298     if (!connection) return;
2299     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2300 }
2301 
2302 
2303 // Configure Secure Simple Pairing
2304 
2305 // enable will enable SSP during init
2306 void hci_ssp_set_enable(int enable){
2307     hci_stack->ssp_enable = enable;
2308 }
2309 
2310 int hci_local_ssp_activated(){
2311     return hci_ssp_supported() && hci_stack->ssp_enable;
2312 }
2313 
2314 // if set, BTstack will respond to io capability request using authentication requirement
2315 void hci_ssp_set_io_capability(int io_capability){
2316     hci_stack->ssp_io_capability = io_capability;
2317 }
2318 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2319     hci_stack->ssp_authentication_requirement = authentication_requirement;
2320 }
2321 
2322 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2323 void hci_ssp_set_auto_accept(int auto_accept){
2324     hci_stack->ssp_auto_accept = auto_accept;
2325 }
2326 
2327 /**
2328  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2329  */
2330 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2331 
2332     if (!hci_can_send_command_packet_now()){
2333         log_error("hci_send_cmd called but cannot send packet now");
2334         return 0;
2335     }
2336 
2337     // for HCI INITIALIZATION
2338     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2339     hci_stack->last_cmd_opcode = cmd->opcode;
2340 
2341     hci_reserve_packet_buffer();
2342     uint8_t * packet = hci_stack->hci_packet_buffer;
2343 
2344     va_list argptr;
2345     va_start(argptr, cmd);
2346     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2347     va_end(argptr);
2348 
2349     return hci_send_cmd_packet(packet, size);
2350 }
2351 
2352 // Create various non-HCI events.
2353 // TODO: generalize, use table similar to hci_create_command
2354 
2355 void hci_emit_state(){
2356     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2357     uint8_t event[3];
2358     event[0] = BTSTACK_EVENT_STATE;
2359     event[1] = sizeof(event) - 2;
2360     event[2] = hci_stack->state;
2361     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2362     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2363 }
2364 
2365 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2366     uint8_t event[13];
2367     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2368     event[1] = sizeof(event) - 2;
2369     event[2] = status;
2370     bt_store_16(event, 3, conn->con_handle);
2371     bt_flip_addr(&event[5], conn->address);
2372     event[11] = 1; // ACL connection
2373     event[12] = 0; // encryption disabled
2374     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2375     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2376 }
2377 
2378 void hci_emit_le_connection_complete(uint8_t address_type, bd_addr_t * address, uint16_t conn_handle, uint8_t status){
2379     uint8_t event[21];
2380     event[0] = HCI_EVENT_LE_META;
2381     event[1] = sizeof(event) - 2;
2382     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2383     event[3] = status;
2384     bt_store_16(event, 4, conn_handle);
2385     event[6] = 0; // TODO: role
2386     event[7] = address_type;
2387     bt_flip_addr(&event[8], *address);
2388     bt_store_16(event, 14, 0); // interval
2389     bt_store_16(event, 16, 0); // latency
2390     bt_store_16(event, 18, 0); // supervision timeout
2391     event[20] = 0; // master clock accuracy
2392     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2393     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2394 }
2395 
2396 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2397     uint8_t event[6];
2398     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2399     event[1] = sizeof(event) - 2;
2400     event[2] = 0; // status = OK
2401     bt_store_16(event, 3, handle);
2402     event[5] = reason;
2403     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2404     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2405 }
2406 
2407 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2408     if (disable_l2cap_timeouts) return;
2409     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2410     uint8_t event[4];
2411     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2412     event[1] = sizeof(event) - 2;
2413     bt_store_16(event, 2, conn->con_handle);
2414     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2415     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2416 }
2417 
2418 void hci_emit_nr_connections_changed(){
2419     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2420     uint8_t event[3];
2421     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2422     event[1] = sizeof(event) - 2;
2423     event[2] = nr_hci_connections();
2424     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2425     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2426 }
2427 
2428 void hci_emit_hci_open_failed(){
2429     log_info("BTSTACK_EVENT_POWERON_FAILED");
2430     uint8_t event[2];
2431     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2432     event[1] = sizeof(event) - 2;
2433     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2434     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2435 }
2436 
2437 #ifndef EMBEDDED
2438 void hci_emit_btstack_version() {
2439     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2440     uint8_t event[6];
2441     event[0] = BTSTACK_EVENT_VERSION;
2442     event[1] = sizeof(event) - 2;
2443     event[2] = BTSTACK_MAJOR;
2444     event[3] = BTSTACK_MINOR;
2445     bt_store_16(event, 4, BTSTACK_REVISION);
2446     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2447     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2448 }
2449 #endif
2450 
2451 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2452     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2453     uint8_t event[3];
2454     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2455     event[1] = sizeof(event) - 2;
2456     event[2] = enabled;
2457     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2458     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2459 }
2460 
2461 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
2462     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2463     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2464     event[1] = sizeof(event) - 2 - 1;
2465     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2466     bt_flip_addr(&event[3], *addr);
2467     memcpy(&event[9], name, 248);
2468 
2469     event[9+248] = 0;   // assert \0 for log_info
2470     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
2471 
2472     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2473     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2474 }
2475 
2476 void hci_emit_discoverable_enabled(uint8_t enabled){
2477     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2478     uint8_t event[3];
2479     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2480     event[1] = sizeof(event) - 2;
2481     event[2] = enabled;
2482     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2483     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2484 }
2485 
2486 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2487     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2488     uint8_t event[5];
2489     int pos = 0;
2490     event[pos++] = GAP_SECURITY_LEVEL;
2491     event[pos++] = sizeof(event) - 2;
2492     bt_store_16(event, 2, con_handle);
2493     pos += 2;
2494     event[pos++] = level;
2495     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2496     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2497 }
2498 
2499 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2500     log_info("hci_emit_dedicated_bonding_result %u ", status);
2501     uint8_t event[9];
2502     int pos = 0;
2503     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2504     event[pos++] = sizeof(event) - 2;
2505     event[pos++] = status;
2506     bt_flip_addr( * (bd_addr_t *) &event[pos], address);
2507     pos += 6;
2508     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2509     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2510 }
2511 
2512 // query if remote side supports SSP
2513 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2514     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2515     if (!connection) return 0;
2516     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2517 }
2518 
2519 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2520     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2521 }
2522 
2523 // GAP API
2524 /**
2525  * @bbrief enable/disable bonding. default is enabled
2526  * @praram enabled
2527  */
2528 void gap_set_bondable_mode(int enable){
2529     hci_stack->bondable = enable ? 1 : 0;
2530 }
2531 
2532 /**
2533  * @brief map link keys to security levels
2534  */
2535 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2536     switch (link_key_type){
2537         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2538             return LEVEL_4;
2539         case COMBINATION_KEY:
2540         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2541             return LEVEL_3;
2542         default:
2543             return LEVEL_2;
2544     }
2545 }
2546 
2547 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2548     if (!connection) return LEVEL_0;
2549     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2550     return gap_security_level_for_link_key_type(connection->link_key_type);
2551 }
2552 
2553 
2554 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2555     log_info("gap_mitm_protection_required_for_security_level %u", level);
2556     return level > LEVEL_2;
2557 }
2558 
2559 /**
2560  * @brief get current security level
2561  */
2562 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2563     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2564     if (!connection) return LEVEL_0;
2565     return gap_security_level_for_connection(connection);
2566 }
2567 
2568 /**
2569  * @brief request connection to device to
2570  * @result GAP_AUTHENTICATION_RESULT
2571  */
2572 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2573     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2574     if (!connection){
2575         hci_emit_security_level(con_handle, LEVEL_0);
2576         return;
2577     }
2578     gap_security_level_t current_level = gap_security_level(con_handle);
2579     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2580     if (current_level >= requested_level){
2581         hci_emit_security_level(con_handle, current_level);
2582         return;
2583     }
2584 
2585     connection->requested_security_level = requested_level;
2586 
2587 #if 0
2588     // sending encryption request without a link key results in an error.
2589     // TODO: figure out how to use it properly
2590 
2591     // would enabling ecnryption suffice (>= LEVEL_2)?
2592     if (hci_stack->remote_device_db){
2593         link_key_type_t link_key_type;
2594         link_key_t      link_key;
2595         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2596             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2597                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2598                 return;
2599             }
2600         }
2601     }
2602 #endif
2603 
2604     // try to authenticate connection
2605     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2606     hci_run();
2607 }
2608 
2609 /**
2610  * @brief start dedicated bonding with device. disconnect after bonding
2611  * @param device
2612  * @param request MITM protection
2613  * @result GAP_DEDICATED_BONDING_COMPLETE
2614  */
2615 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2616 
2617     // create connection state machine
2618     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2619 
2620     if (!connection){
2621         return BTSTACK_MEMORY_ALLOC_FAILED;
2622     }
2623 
2624     // delete linkn key
2625     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2626 
2627     // configure LEVEL_2/3, dedicated bonding
2628     connection->state = SEND_CREATE_CONNECTION;
2629     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2630     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2631     connection->bonding_flags = BONDING_DEDICATED;
2632 
2633     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2634 
2635     // handle: connnection failure (connection complete != ok)
2636     // handle: authentication failure
2637     // handle: disconnect on done
2638 
2639     hci_run();
2640 
2641     return 0;
2642 }
2643 
2644 void gap_set_local_name(const char * local_name){
2645     hci_stack->local_name = local_name;
2646 }
2647 
2648 le_command_status_t le_central_start_scan(){
2649     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2650     hci_stack->le_scanning_state = LE_START_SCAN;
2651     hci_run();
2652     return BLE_PERIPHERAL_OK;
2653 }
2654 
2655 le_command_status_t le_central_stop_scan(){
2656     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2657     hci_stack->le_scanning_state = LE_STOP_SCAN;
2658     hci_run();
2659     return BLE_PERIPHERAL_OK;
2660 }
2661 
2662 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2663     hci_stack->le_scan_type     = scan_type;
2664     hci_stack->le_scan_interval = scan_interval;
2665     hci_stack->le_scan_window   = scan_window;
2666     hci_run();
2667 }
2668 
2669 le_command_status_t le_central_connect(bd_addr_t * addr, bd_addr_type_t addr_type){
2670     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2671     if (!conn){
2672         log_info("le_central_connect: no connection exists yet, creating context");
2673         conn = create_connection_for_bd_addr_and_type(*addr, addr_type);
2674         if (!conn){
2675             // notify client that alloc failed
2676             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
2677             log_info("le_central_connect: failed to alloc hci_connection_t");
2678             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2679         }
2680         conn->state = SEND_CREATE_CONNECTION;
2681         log_info("le_central_connect: send create connection next");
2682         hci_run();
2683         return BLE_PERIPHERAL_OK;
2684     }
2685 
2686     if (!hci_is_le_connection(conn) ||
2687         conn->state == SEND_CREATE_CONNECTION ||
2688         conn->state == SENT_CREATE_CONNECTION) {
2689         hci_emit_le_connection_complete(conn->address_type, &conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
2690         log_error("le_central_connect: classic connection or connect is already being created");
2691         return BLE_PERIPHERAL_IN_WRONG_STATE;
2692     }
2693 
2694     log_info("le_central_connect: context exists with state %u", conn->state);
2695     hci_emit_le_connection_complete(conn->address_type, &conn->address, conn->con_handle, 0);
2696     hci_run();
2697     return BLE_PERIPHERAL_OK;
2698 }
2699 
2700 // @assumption: only a single outgoing LE Connection exists
2701 static hci_connection_t * le_central_get_outgoing_connection(){
2702     linked_item_t *it;
2703     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2704         hci_connection_t * conn = (hci_connection_t *) it;
2705         if (!hci_is_le_connection(conn)) continue;
2706         switch (conn->state){
2707             case SEND_CREATE_CONNECTION:
2708             case SENT_CREATE_CONNECTION:
2709                 return conn;
2710             default:
2711                 break;
2712         };
2713     }
2714     return NULL;
2715 }
2716 
2717 le_command_status_t le_central_connect_cancel(){
2718     hci_connection_t * conn = le_central_get_outgoing_connection();
2719     switch (conn->state){
2720         case SEND_CREATE_CONNECTION:
2721             // skip sending create connection and emit event instead
2722             hci_emit_le_connection_complete(conn->address_type, &conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2723             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2724             btstack_memory_hci_connection_free( conn );
2725             break;
2726         case SENT_CREATE_CONNECTION:
2727             // request to send cancel connection
2728             conn->state = SEND_CANCEL_CONNECTION;
2729             hci_run();
2730             break;
2731         default:
2732             break;
2733     }
2734     return BLE_PERIPHERAL_OK;
2735 }
2736 
2737 /**
2738  * @brief Updates the connection parameters for a given LE connection
2739  * @param handle
2740  * @param conn_interval_min (unit: 1.25ms)
2741  * @param conn_interval_max (unit: 1.25ms)
2742  * @param conn_latency
2743  * @param supervision_timeout (unit: 10ms)
2744  * @returns 0 if ok
2745  */
2746 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2747     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2748     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2749     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2750     connection->le_conn_interval_min = conn_interval_min;
2751     connection->le_conn_interval_max = conn_interval_max;
2752     connection->le_conn_latency = conn_latency;
2753     connection->le_supervision_timeout = supervision_timeout;
2754     return 0;
2755 }
2756 
2757 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2758     hci_connection_t * conn = hci_connection_for_handle(handle);
2759     if (!conn){
2760         hci_emit_disconnection_complete(handle, 0);
2761         return BLE_PERIPHERAL_OK;
2762     }
2763     conn->state = SEND_DISCONNECT;
2764     hci_run();
2765     return BLE_PERIPHERAL_OK;
2766 }
2767 
2768 void hci_disconnect_all(){
2769     linked_list_iterator_t it;
2770     linked_list_iterator_init(&it, &hci_stack->connections);
2771     while (linked_list_iterator_has_next(&it)){
2772         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2773         if (con->state == SENT_DISCONNECT) continue;
2774         con->state = SEND_DISCONNECT;
2775     }
2776     hci_run();
2777 }
2778