xref: /btstack/src/hci.c (revision 6c26b087476c4858600668a8fc09217a9cc8ecff)
1 /*
2  * Copyright (C) 2009-2012 by Matthias Ringwald
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at [email protected]
34  *
35  */
36 
37 /*
38  *  hci.c
39  *
40  *  Created by Matthias Ringwald on 4/29/09.
41  *
42  */
43 
44 #include "btstack-config.h"
45 
46 #include "hci.h"
47 #include "gap.h"
48 
49 #include <stdarg.h>
50 #include <string.h>
51 #include <stdio.h>
52 
53 #ifndef EMBEDDED
54 #include <unistd.h> // gethostbyname
55 #include <btstack/version.h>
56 #endif
57 
58 #include "btstack_memory.h"
59 #include "debug.h"
60 #include "hci_dump.h"
61 
62 #include <btstack/hci_cmds.h>
63 
64 #define HCI_CONNECTION_TIMEOUT_MS 10000
65 
66 #define HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP 11
67 
68 #ifdef USE_BLUETOOL
69 #include "../platforms/ios/src/bt_control_iphone.h"
70 #endif
71 
72 static void hci_update_scan_enable(void);
73 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
74 static void hci_connection_timeout_handler(timer_source_t *timer);
75 static void hci_connection_timestamp(hci_connection_t *connection);
76 static int  hci_power_control_on(void);
77 static void hci_power_control_off(void);
78 static void hci_state_reset();
79 
80 // the STACK is here
81 #ifndef HAVE_MALLOC
82 static hci_stack_t   hci_stack_static;
83 #endif
84 static hci_stack_t * hci_stack = NULL;
85 
86 // test helper
87 static uint8_t disable_l2cap_timeouts = 0;
88 
89 /**
90  * create connection for given address
91  *
92  * @return connection OR NULL, if no memory left
93  */
94 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
95 
96     log_info("create_connection_for_addr %s", bd_addr_to_str(addr));
97     hci_connection_t * conn = btstack_memory_hci_connection_get();
98     if (!conn) return NULL;
99     BD_ADDR_COPY(conn->address, addr);
100     conn->address_type = addr_type;
101     conn->con_handle = 0xffff;
102     conn->authentication_flags = AUTH_FLAGS_NONE;
103     conn->bonding_flags = 0;
104     conn->requested_security_level = LEVEL_0;
105     linked_item_set_user(&conn->timeout.item, conn);
106     conn->timeout.process = hci_connection_timeout_handler;
107     hci_connection_timestamp(conn);
108     conn->acl_recombination_length = 0;
109     conn->acl_recombination_pos = 0;
110     conn->num_acl_packets_sent = 0;
111     linked_list_add(&hci_stack->connections, (linked_item_t *) conn);
112     return conn;
113 }
114 
115 /**
116  * get connection for a given handle
117  *
118  * @return connection OR NULL, if not found
119  */
120 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
121     linked_item_t *it;
122     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
123         if ( ((hci_connection_t *) it)->con_handle == con_handle){
124             return (hci_connection_t *) it;
125         }
126     }
127     return NULL;
128 }
129 
130 /**
131  * get connection for given address
132  *
133  * @return connection OR NULL, if not found
134  */
135 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t * addr, bd_addr_type_t addr_type){
136     linked_item_t *it;
137     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
138         hci_connection_t * connection = (hci_connection_t *) it;
139         if (connection->address_type != addr_type)  continue;
140         if (memcmp(addr, connection->address, 6) != 0) continue;
141         return connection;
142     }
143     return NULL;
144 }
145 
146 static void hci_connection_timeout_handler(timer_source_t *timer){
147     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
148 #ifdef HAVE_TIME
149     struct timeval tv;
150     gettimeofday(&tv, NULL);
151     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
152         // connections might be timed out
153         hci_emit_l2cap_check_timeout(connection);
154     }
155 #endif
156 #ifdef HAVE_TICK
157     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
158         // connections might be timed out
159         hci_emit_l2cap_check_timeout(connection);
160     }
161 #endif
162     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
163     run_loop_add_timer(timer);
164 }
165 
166 static void hci_connection_timestamp(hci_connection_t *connection){
167 #ifdef HAVE_TIME
168     gettimeofday(&connection->timestamp, NULL);
169 #endif
170 #ifdef HAVE_TICK
171     connection->timestamp = embedded_get_ticks();
172 #endif
173 }
174 
175 
176 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
177     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
178 }
179 
180 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
181     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
182 }
183 
184 
185 /**
186  * add authentication flags and reset timer
187  * @note: assumes classic connection
188  */
189 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
190     bd_addr_t addr;
191     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
192     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
193     if (conn) {
194         connectionSetAuthenticationFlags(conn, flags);
195         hci_connection_timestamp(conn);
196     }
197 }
198 
199 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
200     hci_connection_t * conn = hci_connection_for_handle(handle);
201     if (!conn) return 0;
202     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
203     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
204     return 0;
205 }
206 
207 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
208     if (hci_stack->remote_device_db) {
209         hci_stack->remote_device_db->delete_link_key(addr);
210     }
211 }
212 
213 int hci_is_le_connection(hci_connection_t * connection){
214     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
215     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
216 }
217 
218 
219 /**
220  * count connections
221  */
222 static int nr_hci_connections(void){
223     int count = 0;
224     linked_item_t *it;
225     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
226     return count;
227 }
228 
229 /**
230  * Dummy handler called by HCI
231  */
232 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
233 }
234 
235 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
236     hci_connection_t * connection = hci_connection_for_handle(handle);
237     if (!connection) {
238         log_error("hci_number_outgoing_packets: connection for handle %u does not exist!", handle);
239         return 0;
240     }
241     return connection->num_acl_packets_sent;
242 }
243 
244 uint8_t hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
245 
246     int num_packets_sent_classic = 0;
247     int num_packets_sent_le = 0;
248 
249     bd_addr_type_t address_type = BD_ADDR_TYPE_UNKNOWN;
250 
251     linked_item_t *it;
252     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
253         hci_connection_t * connection = (hci_connection_t *) it;
254         if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
255             num_packets_sent_classic += connection->num_acl_packets_sent;
256         } else {
257             num_packets_sent_le += connection->num_acl_packets_sent;
258         }
259         if (connection->con_handle == con_handle){
260             address_type = connection->address_type;
261         }
262     }
263 
264     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
265     int free_slots_le = 0;
266 
267     if (free_slots_classic < 0){
268         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);
269         return 0;
270     }
271 
272     if (hci_stack->le_acl_packets_total_num){
273         // if we have LE slots, they are used
274         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
275         if (free_slots_le < 0){
276             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);
277             return 0;
278         }
279     } else {
280         // otherwise, classic slots are used for LE, too
281         free_slots_classic -= num_packets_sent_le;
282         if (free_slots_classic < 0){
283             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);
284             return 0;
285         }
286     }
287 
288     switch (address_type){
289         case BD_ADDR_TYPE_UNKNOWN:
290             log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
291             return 0;
292 
293         case BD_ADDR_TYPE_CLASSIC:
294             return free_slots_classic;
295 
296         default:
297            if (hci_stack->le_acl_packets_total_num){
298                return free_slots_le;
299            }
300            return free_slots_classic;
301     }
302 }
303 
304 
305 // @deprecated
306 int hci_can_send_packet_now(uint8_t packet_type){
307     switch (packet_type) {
308         case HCI_ACL_DATA_PACKET:
309             return hci_can_send_prepared_acl_packet_now(0);
310         case HCI_COMMAND_DATA_PACKET:
311             return hci_can_send_command_packet_now();
312         default:
313             return 0;
314     }
315 }
316 
317 // @deprecated
318 // same as hci_can_send_packet_now, but also checks if packet buffer is free for use
319 int hci_can_send_packet_now_using_packet_buffer(uint8_t packet_type){
320 
321     if (hci_stack->hci_packet_buffer_reserved) return 0;
322 
323     switch (packet_type) {
324         case HCI_ACL_DATA_PACKET:
325             return hci_can_send_acl_packet_now(0);
326         case HCI_COMMAND_DATA_PACKET:
327             return hci_can_send_command_packet_now();
328         default:
329             return 0;
330     }
331 }
332 
333 
334 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
335 int hci_can_send_command_packet_now(void){
336     if (hci_stack->hci_packet_buffer_reserved) return 0;
337 
338     // check for async hci transport implementations
339     if (hci_stack->hci_transport->can_send_packet_now){
340         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
341             return 0;
342         }
343     }
344 
345     return hci_stack->num_cmd_packets > 0;
346 }
347 
348 int hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
349     // check for async hci transport implementations
350     if (hci_stack->hci_transport->can_send_packet_now){
351         if (!hci_stack->hci_transport->can_send_packet_now(HCI_ACL_DATA_PACKET)){
352             return 0;
353         }
354     }
355     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
356 }
357 
358 int hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
359     if (hci_stack->hci_packet_buffer_reserved) return 0;
360     return hci_can_send_prepared_acl_packet_now(con_handle);
361 }
362 
363 // used for internal checks in l2cap[-le].c
364 int hci_is_packet_buffer_reserved(void){
365     return hci_stack->hci_packet_buffer_reserved;
366 }
367 
368 // reserves outgoing packet buffer. @returns 1 if successful
369 int hci_reserve_packet_buffer(void){
370     if (hci_stack->hci_packet_buffer_reserved) {
371         log_error("hci_reserve_packet_buffer called but buffer already reserved");
372         return 0;
373     }
374     hci_stack->hci_packet_buffer_reserved = 1;
375     return 1;
376 }
377 
378 void hci_release_packet_buffer(void){
379     hci_stack->hci_packet_buffer_reserved = 0;
380 }
381 
382 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
383 int hci_transport_synchronous(void){
384     return hci_stack->hci_transport->can_send_packet_now == NULL;
385 }
386 
387 uint16_t hci_max_acl_le_data_packet_length(void){
388     return hci_stack->le_data_packets_length > 0 ? hci_stack->le_data_packets_length : hci_stack->acl_data_packet_length;
389 }
390 
391 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
392 
393     // 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);
394 
395     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
396     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
397     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
398         max_acl_data_packet_length = hci_stack->le_data_packets_length;
399     }
400 
401     // testing: reduce buffer to minimum
402     // max_acl_data_packet_length = 52;
403 
404     int err;
405     // multiple packets could be send on a synchronous HCI transport
406     while (1){
407 
408         // get current data
409         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
410         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
411         int more_fragments = 0;
412 
413         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
414         if (current_acl_data_packet_length > max_acl_data_packet_length){
415             more_fragments = 1;
416             current_acl_data_packet_length = max_acl_data_packet_length;
417         }
418 
419         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
420         if (acl_header_pos > 0){
421             uint16_t handle_and_flags = READ_BT_16(hci_stack->hci_packet_buffer, 0);
422             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
423             bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
424         }
425 
426         // update header len
427         bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
428 
429         // count packet
430         connection->num_acl_packets_sent++;
431 
432         // send packet
433         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
434         const int size = current_acl_data_packet_length + 4;
435         // hexdump(packet, size);
436         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
437 
438         // done yet?
439         if (!more_fragments) break;
440 
441         // update start of next fragment to send
442         hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
443 
444         // can send more?
445         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
446     }
447 
448     // done
449     hci_stack->acl_fragmentation_pos = 0;
450     hci_stack->acl_fragmentation_total_size = 0;
451 
452     // free buffer now for synchronous transport
453     if (!hci_transport_synchronous()){
454         hci_release_packet_buffer();
455     }
456 
457     return err;
458 }
459 
460 // pre: caller has reserved the packet buffer
461 int hci_send_acl_packet_buffer(int size){
462 
463     // log_info("hci_send_acl_packet_buffer size %u", size);
464 
465     if (!hci_stack->hci_packet_buffer_reserved) {
466         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
467         return 0;
468     }
469 
470     uint8_t * packet = hci_stack->hci_packet_buffer;
471     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
472 
473     // check for free places on Bluetooth module
474     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
475         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
476         hci_release_packet_buffer();
477         return BTSTACK_ACL_BUFFERS_FULL;
478     }
479 
480     hci_connection_t *connection = hci_connection_for_handle( con_handle);
481     if (!connection) {
482         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
483         hci_release_packet_buffer();
484         return 0;
485     }
486     hci_connection_timestamp(connection);
487 
488     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
489 
490     // setup data
491     hci_stack->acl_fragmentation_total_size = size;
492     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
493 
494     return hci_send_acl_packet_fragments(connection);
495 }
496 
497 static void acl_handler(uint8_t *packet, int size){
498 
499     // log_info("acl_handler: size %u", size);
500 
501     // get info
502     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
503     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
504     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
505     uint16_t acl_length         = READ_ACL_LENGTH(packet);
506 
507     // ignore non-registered handle
508     if (!conn){
509         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
510         return;
511     }
512 
513     // assert packet is complete
514     if (acl_length + 4 != size){
515         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
516         return;
517     }
518 
519     // update idle timestamp
520     hci_connection_timestamp(conn);
521 
522     // handle different packet types
523     switch (acl_flags & 0x03) {
524 
525         case 0x01: // continuation fragment
526 
527             // sanity check
528             if (conn->acl_recombination_pos == 0) {
529                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
530                 return;
531             }
532 
533             // append fragment payload (header already stored)
534             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
535             conn->acl_recombination_pos += acl_length;
536 
537             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
538             //        conn->acl_recombination_pos, conn->acl_recombination_length);
539 
540             // forward complete L2CAP packet if complete.
541             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
542 
543                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
544                 // reset recombination buffer
545                 conn->acl_recombination_length = 0;
546                 conn->acl_recombination_pos = 0;
547             }
548             break;
549 
550         case 0x02: { // first fragment
551 
552             // sanity check
553             if (conn->acl_recombination_pos) {
554                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x", con_handle);
555                 return;
556             }
557 
558             // peek into L2CAP packet!
559             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
560 
561             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
562 
563             // compare fragment size to L2CAP packet size
564             if (acl_length >= l2cap_length + 4){
565 
566                 // forward fragment as L2CAP packet
567                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
568 
569             } else {
570                 // store first fragment and tweak acl length for complete package
571                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
572                 conn->acl_recombination_pos    = acl_length + 4;
573                 conn->acl_recombination_length = l2cap_length;
574                 bt_store_16(conn->acl_recombination_buffer, 2, l2cap_length +4);
575             }
576             break;
577 
578         }
579         default:
580             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
581             return;
582     }
583 
584     // execute main loop
585     hci_run();
586 }
587 
588 static void hci_shutdown_connection(hci_connection_t *conn){
589     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
590 
591     run_loop_remove_timer(&conn->timeout);
592 
593     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
594     btstack_memory_hci_connection_free( conn );
595 
596     // now it's gone
597     hci_emit_nr_connections_changed();
598 }
599 
600 static const uint16_t packet_type_sizes[] = {
601     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
602     HCI_ACL_DH1_SIZE, 0, 0, 0,
603     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
604     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
605 };
606 static const uint8_t  packet_type_feature_requirement_bit[] = {
607      0, // 3 slot packets
608      1, // 5 slot packets
609     25, // EDR 2 mpbs
610     26, // EDR 3 mbps
611     39, // 3 slot EDR packts
612     40, // 5 slot EDR packet
613 };
614 static const uint16_t packet_type_feature_packet_mask[] = {
615     0x0f00, // 3 slot packets
616     0xf000, // 5 slot packets
617     0x1102, // EDR 2 mpbs
618     0x2204, // EDR 3 mbps
619     0x0300, // 3 slot EDR packts
620     0x3000, // 5 slot EDR packet
621 };
622 
623 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
624     // enable packet types based on size
625     uint16_t packet_types = 0;
626     int i;
627     for (i=0;i<16;i++){
628         if (packet_type_sizes[i] == 0) continue;
629         if (packet_type_sizes[i] <= buffer_size){
630             packet_types |= 1 << i;
631         }
632     }
633     // disable packet types due to missing local supported features
634     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
635         int bit_idx = packet_type_feature_requirement_bit[i];
636         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
637         if (feature_set) continue;
638         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
639         packet_types &= ~packet_type_feature_packet_mask[i];
640     }
641     // flip bits for "may not be used"
642     packet_types ^= 0x3306;
643     return packet_types;
644 }
645 
646 uint16_t hci_usable_acl_packet_types(void){
647     return hci_stack->packet_types;
648 }
649 
650 uint8_t* hci_get_outgoing_packet_buffer(void){
651     // hci packet buffer is >= acl data packet length
652     return hci_stack->hci_packet_buffer;
653 }
654 
655 uint16_t hci_max_acl_data_packet_length(void){
656     return hci_stack->acl_data_packet_length;
657 }
658 
659 int hci_non_flushable_packet_boundary_flag_supported(void){
660     // No. 54, byte 6, bit 6
661     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
662 }
663 
664 int hci_ssp_supported(void){
665     // No. 51, byte 6, bit 3
666     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
667 }
668 
669 int hci_classic_supported(void){
670     // No. 37, byte 4, bit 5, = No BR/EDR Support
671     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
672 }
673 
674 int hci_le_supported(void){
675 #ifdef HAVE_BLE
676     // No. 37, byte 4, bit 6 = LE Supported (Controller)
677     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
678 #else
679     return 0;
680 #endif
681 }
682 
683 // get addr type and address used in advertisement packets
684 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
685     *addr_type = hci_stack->adv_addr_type;
686     if (hci_stack->adv_addr_type){
687         memcpy(addr, hci_stack->adv_address, 6);
688     } else {
689         memcpy(addr, hci_stack->local_bd_addr, 6);
690     }
691 }
692 
693 #ifdef HAVE_BLE
694 void le_handle_advertisement_report(uint8_t *packet, int size){
695     int offset = 3;
696     int num_reports = packet[offset];
697     offset += 1;
698 
699     int i;
700     log_info("HCI: handle adv report with num reports: %d", num_reports);
701     for (i=0; i<num_reports;i++){
702         uint8_t data_length = packet[offset + 8];
703         uint8_t event_size = 10 + data_length;
704         uint8_t event[2 + event_size ];
705         int pos = 0;
706         event[pos++] = GAP_LE_ADVERTISING_REPORT;
707         event[pos++] = event_size;
708         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
709         offset += 8;
710         pos += 8;
711         event[pos++] = packet[offset + 1 + data_length]; // rssi
712         event[pos++] = packet[offset++]; //data_length;
713         memcpy(&event[pos], &packet[offset], data_length);
714         pos += data_length;
715         offset += data_length + 1; // rssi
716         hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
717         hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
718     }
719 }
720 #endif
721 
722 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
723     uint8_t command_completed = 0;
724     if ((hci_stack->substate % 2) == 0) return;
725     // odd: waiting for event
726     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
727         uint16_t opcode = READ_BT_16(packet,3);
728         if (opcode == hci_stack->last_cmd_opcode){
729             command_completed = 1;
730             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate);
731         } else {
732             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
733         }
734     }
735     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
736         uint8_t  status = packet[2];
737         uint16_t opcode = READ_BT_16(packet,4);
738         if (opcode == hci_stack->last_cmd_opcode){
739             if (status){
740                 command_completed = 1;
741                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate);
742             } else {
743                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
744             }
745         } else {
746             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
747         }
748     }
749 
750     if (!command_completed) return;
751 
752     switch(hci_stack->substate >> 1){
753         default:
754             hci_stack->substate++;
755             break;
756     }
757 }
758 
759 static void hci_initializing_state_machine(){
760         // log_info("hci_init: substate %u", hci_stack->substate);
761     if (hci_stack->substate % 2) {
762         // odd: waiting for command completion
763         return;
764     }
765     switch (hci_stack->substate >> 1){
766         case 0: // RESET
767             hci_state_reset();
768 
769             hci_send_cmd(&hci_reset);
770             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
771                 // skip baud change
772                 hci_stack->substate = 4; // >> 1 = 2
773             }
774             break;
775         case 1: // SEND BAUD CHANGE
776             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
777             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
778             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
779             break;
780         case 2: // LOCAL BAUD CHANGE
781             log_info("Local baud rate change");
782             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
783             hci_stack->substate += 2;
784             // break missing here for fall through
785 
786         case 3:
787             log_info("Custom init");
788             // Custom initialization
789             if (hci_stack->control && hci_stack->control->next_cmd){
790                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
791                 if (valid_cmd){
792                     int size = 3 + hci_stack->hci_packet_buffer[2];
793                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
794                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
795                     hci_stack->substate = 4; // more init commands
796                     break;
797                 }
798                 log_info("hci_run: init script done");
799             }
800             // otherwise continue
801             hci_send_cmd(&hci_read_bd_addr);
802             break;
803         case 4:
804             hci_send_cmd(&hci_read_buffer_size);
805             break;
806         case 5:
807             hci_send_cmd(&hci_read_local_supported_features);
808             break;
809         case 6:
810             if (hci_le_supported()){
811                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
812             } else {
813                 // Kensington Bluetoot 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
814                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
815             }
816 
817             // skip Classic init commands for LE only chipsets
818             if (!hci_classic_supported()){
819                 if (hci_le_supported()){
820                     hci_stack->substate = 11 << 1;    // skip all classic command
821                 } else {
822                     log_error("Neither BR/EDR nor LE supported");
823                     hci_stack->substate = 14 << 1;    // skip all
824                 }
825             }
826             break;
827         case 7:
828             if (hci_ssp_supported()){
829                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
830                 break;
831             }
832             hci_stack->substate += 2;
833             // break missing here for fall through
834 
835         case 8:
836             // ca. 15 sec
837             hci_send_cmd(&hci_write_page_timeout, 0x6000);
838             break;
839         case 9:
840             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
841             break;
842         case 10:
843             if (hci_stack->local_name){
844                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
845             } else {
846                 char hostname[30];
847 #ifdef EMBEDDED
848                 // BTstack-11:22:33:44:55:66
849                 strcpy(hostname, "BTstack ");
850                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
851                 log_info("---> Name %s", hostname);
852 #else
853                 // hostname for POSIX systems
854                 gethostname(hostname, 30);
855                 hostname[29] = '\0';
856 #endif
857                 hci_send_cmd(&hci_write_local_name, hostname);
858             }
859             break;
860         case 11:
861             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
862             if (!hci_le_supported()){
863                 // SKIP LE init for Classic only configuration
864                 hci_stack->substate = 14 << 1;
865             }
866             break;
867 
868 #ifdef HAVE_BLE
869         // LE INIT
870         case 12:
871             hci_send_cmd(&hci_le_read_buffer_size);
872             break;
873         case 13:
874             // LE Supported Host = 1, Simultaneous Host = 0
875             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
876             break;
877         case 14:
878             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
879             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
880             break;
881 #endif
882 
883         // DONE
884         case 15:
885             // done.
886             hci_stack->state = HCI_STATE_WORKING;
887             hci_emit_state();
888             break;
889         default:
890             break;
891     }
892     hci_stack->substate++;
893 }
894 
895 // avoid huge local variables
896 #ifndef EMBEDDED
897 static device_name_t device_name;
898 #endif
899 static void event_handler(uint8_t *packet, int size){
900 
901     uint16_t event_length = packet[1];
902 
903     // assert packet is complete
904     if (size != event_length + 2){
905         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
906         return;
907     }
908 
909     bd_addr_t addr;
910     bd_addr_type_t addr_type;
911     uint8_t link_type;
912     hci_con_handle_t handle;
913     hci_connection_t * conn;
914     int i;
915 
916     // log_info("HCI:EVENT:%02x", packet[0]);
917 
918     switch (packet[0]) {
919 
920         case HCI_EVENT_COMMAND_COMPLETE:
921             // get num cmd packets
922             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
923             hci_stack->num_cmd_packets = packet[2];
924 
925             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
926                 // from offset 5
927                 // status
928                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
929                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
930                 // ignore: SCO data packet len (8)
931                 hci_stack->acl_packets_total_num  = packet[9];
932                 // ignore: total num SCO packets
933                 if (hci_stack->state == HCI_STATE_INITIALIZING){
934                     // determine usable ACL payload size
935                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
936                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
937                     }
938                     log_info("hci_read_buffer_size: used size %u, count %u",
939                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num);
940                 }
941             }
942 #ifdef HAVE_BLE
943             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
944                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
945                 hci_stack->le_acl_packets_total_num  = packet[8];
946                     // determine usable ACL payload size
947                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
948                         hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
949                     }
950                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
951             }
952 #endif
953             // Dump local address
954             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
955                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
956                 log_info("Local Address, Status: 0x%02x: Addr: %s",
957                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
958             }
959             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
960                 hci_emit_discoverable_enabled(hci_stack->discoverable);
961             }
962             // Note: HCI init checks
963             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
964                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
965                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
966                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
967                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
968                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
969                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
970 
971                 // determine usable ACL packet types based buffer size and supported features
972                 hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(hci_stack->acl_data_packet_length, &hci_stack->local_supported_features[0]);
973                 log_info("packet types %04x", hci_stack->packet_types);
974 
975                 // Classic/LE
976                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
977             }
978             break;
979 
980         case HCI_EVENT_COMMAND_STATUS:
981             // get num cmd packets
982             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
983             hci_stack->num_cmd_packets = packet[3];
984             break;
985 
986         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
987             int offset = 3;
988             for (i=0; i<packet[2];i++){
989                 handle = READ_BT_16(packet, offset);
990                 offset += 2;
991                 uint16_t num_packets = READ_BT_16(packet, offset);
992                 offset += 2;
993 
994                 conn = hci_connection_for_handle(handle);
995                 if (!conn){
996                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
997                     continue;
998                 }
999 
1000                 if (conn->num_acl_packets_sent >= num_packets){
1001                     conn->num_acl_packets_sent -= num_packets;
1002                 } else {
1003                     log_error("hci_number_completed_packets, more slots freed then sent.");
1004                     conn->num_acl_packets_sent = 0;
1005                 }
1006                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
1007             }
1008             break;
1009         }
1010         case HCI_EVENT_CONNECTION_REQUEST:
1011             bt_flip_addr(addr, &packet[2]);
1012             // TODO: eval COD 8-10
1013             link_type = packet[11];
1014             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1015             if (link_type == 1) { // ACL
1016                 conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1017                 if (!conn) {
1018                     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1019                 }
1020                 if (!conn) {
1021                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1022                     hci_stack->decline_reason = 0x0d;
1023                     BD_ADDR_COPY(hci_stack->decline_addr, addr);
1024                     break;
1025                 }
1026                 conn->state = RECEIVED_CONNECTION_REQUEST;
1027                 hci_run();
1028             } else {
1029                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
1030                 hci_stack->decline_reason = 0x0a;
1031                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1032             }
1033             break;
1034 
1035         case HCI_EVENT_CONNECTION_COMPLETE:
1036             // Connection management
1037             bt_flip_addr(addr, &packet[5]);
1038             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1039             addr_type = BD_ADDR_TYPE_CLASSIC;
1040             conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1041             if (conn) {
1042                 if (!packet[2]){
1043                     conn->state = OPEN;
1044                     conn->con_handle = READ_BT_16(packet, 3);
1045                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1046 
1047                     // restart timer
1048                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1049                     run_loop_add_timer(&conn->timeout);
1050 
1051                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1052 
1053                     hci_emit_nr_connections_changed();
1054                 } else {
1055                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1056                     uint8_t status = packet[2];
1057                     bd_addr_t bd_address;
1058                     memcpy(&bd_address, conn->address, 6);
1059 
1060                     // connection failed, remove entry
1061                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1062                     btstack_memory_hci_connection_free( conn );
1063 
1064                     // notify client if dedicated bonding
1065                     if (notify_dedicated_bonding_failed){
1066                         log_info("hci notify_dedicated_bonding_failed");
1067                         hci_emit_dedicated_bonding_result(bd_address, status);
1068                     }
1069 
1070                     // if authentication error, also delete link key
1071                     if (packet[2] == 0x05) {
1072                         hci_drop_link_key_for_bd_addr(&addr);
1073                     }
1074                 }
1075             }
1076             break;
1077 
1078         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1079             handle = READ_BT_16(packet, 3);
1080             conn = hci_connection_for_handle(handle);
1081             if (!conn) break;
1082             if (!packet[2]){
1083                 uint8_t * features = &packet[5];
1084                 if (features[6] & (1 << 3)){
1085                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1086                 }
1087             }
1088             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1089             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1090             if (conn->bonding_flags & BONDING_DEDICATED){
1091                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1092             }
1093             break;
1094 
1095         case HCI_EVENT_LINK_KEY_REQUEST:
1096             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1097             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1098             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1099             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1100             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1101             hci_run();
1102             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1103             return;
1104 
1105         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1106             bt_flip_addr(addr, &packet[2]);
1107             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1108             if (!conn) break;
1109             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1110             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1111             // Change Connection Encryption keeps link key type
1112             if (link_key_type != CHANGED_COMBINATION_KEY){
1113                 conn->link_key_type = link_key_type;
1114             }
1115             if (!hci_stack->remote_device_db) break;
1116             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
1117             // still forward event to allow dismiss of pairing dialog
1118             break;
1119         }
1120 
1121         case HCI_EVENT_PIN_CODE_REQUEST:
1122             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1123             // non-bondable mode: pin code negative reply will be sent
1124             if (!hci_stack->bondable){
1125                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1126                 hci_run();
1127                 return;
1128             }
1129             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1130             if (!hci_stack->remote_device_db) break;
1131             bt_flip_addr(addr, &packet[2]);
1132             hci_stack->remote_device_db->delete_link_key(&addr);
1133             break;
1134 
1135         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1136             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1137             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1138             break;
1139 
1140         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1141             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1142             if (!hci_stack->ssp_auto_accept) break;
1143             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1144             break;
1145 
1146         case HCI_EVENT_USER_PASSKEY_REQUEST:
1147             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1148             if (!hci_stack->ssp_auto_accept) break;
1149             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1150             break;
1151 
1152         case HCI_EVENT_ENCRYPTION_CHANGE:
1153             handle = READ_BT_16(packet, 3);
1154             conn = hci_connection_for_handle(handle);
1155             if (!conn) break;
1156             if (packet[2] == 0) {
1157                 if (packet[5]){
1158                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1159                 } else {
1160                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1161                 }
1162             }
1163             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1164             break;
1165 
1166         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1167             handle = READ_BT_16(packet, 3);
1168             conn = hci_connection_for_handle(handle);
1169             if (!conn) break;
1170 
1171             // dedicated bonding: send result and disconnect
1172             if (conn->bonding_flags & BONDING_DEDICATED){
1173                 conn->bonding_flags &= ~BONDING_DEDICATED;
1174                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1175                 conn->bonding_status = packet[2];
1176                 break;
1177             }
1178 
1179             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1180                 // link key sufficient for requested security
1181                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1182                 break;
1183             }
1184             // not enough
1185             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1186             break;
1187 
1188 #ifndef EMBEDDED
1189         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1190             if (!hci_stack->remote_device_db) break;
1191             if (packet[2]) break; // status not ok
1192             bt_flip_addr(addr, &packet[3]);
1193             // fix for invalid remote names - terminate on 0xff
1194             for (i=0; i<248;i++){
1195                 if (packet[9+i] == 0xff){
1196                     packet[9+i] = 0;
1197                     break;
1198                 }
1199             }
1200             memset(&device_name, 0, sizeof(device_name_t));
1201             strncpy((char*) device_name, (char*) &packet[9], 248);
1202             hci_stack->remote_device_db->put_name(&addr, &device_name);
1203             break;
1204 
1205         case HCI_EVENT_INQUIRY_RESULT:
1206         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1207             if (!hci_stack->remote_device_db) break;
1208             // first send inq result packet
1209             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1210             // then send cached remote names
1211             int offset = 3;
1212             for (i=0; i<packet[2];i++){
1213                 bt_flip_addr(addr, &packet[offset]);
1214                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1215                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
1216                     hci_emit_remote_name_cached(&addr, &device_name);
1217                 }
1218             }
1219             return;
1220         }
1221 #endif
1222 
1223         // HCI_EVENT_DISCONNECTION_COMPLETE
1224         // has been moved down, to first notify stack before shutting connection down
1225 
1226         case HCI_EVENT_HARDWARE_ERROR:
1227             if(hci_stack->control && hci_stack->control->hw_error){
1228                 (*hci_stack->control->hw_error)();
1229             } else {
1230                 // if no special requests, just reboot stack
1231                 hci_power_control_off();
1232                 hci_power_control_on();
1233             }
1234             break;
1235 
1236         case DAEMON_EVENT_HCI_PACKET_SENT:
1237             // free packet buffer for asynchronous transport
1238             if (hci_transport_synchronous()) break;
1239             hci_stack->hci_packet_buffer_reserved = 0;
1240             break;
1241 
1242 #ifdef HAVE_BLE
1243         case HCI_EVENT_LE_META:
1244             switch (packet[2]){
1245                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1246                     log_info("advertising report received");
1247                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1248                     le_handle_advertisement_report(packet, size);
1249                     break;
1250                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1251                     // Connection management
1252                     bt_flip_addr(addr, &packet[8]);
1253                     addr_type = (bd_addr_type_t)packet[7];
1254                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1255                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1256                     conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1257                     if (packet[3]){
1258                         if (conn){
1259                             // outgoing connection failed, remove entry
1260                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1261                             btstack_memory_hci_connection_free( conn );
1262                         }
1263                         // if authentication error, also delete link key
1264                         if (packet[3] == 0x05) {
1265                             hci_drop_link_key_for_bd_addr(&addr);
1266                         }
1267                         break;
1268                     }
1269                     if (!conn){
1270                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1271                     }
1272                     if (!conn){
1273                         // no memory
1274                         break;
1275                     }
1276 
1277                     conn->state = OPEN;
1278                     conn->con_handle = READ_BT_16(packet, 4);
1279 
1280                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1281 
1282                     // restart timer
1283                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1284                     // run_loop_add_timer(&conn->timeout);
1285 
1286                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1287 
1288                     hci_emit_nr_connections_changed();
1289                     break;
1290 
1291             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1292 
1293                 default:
1294                     break;
1295             }
1296             break;
1297 #endif
1298         default:
1299             break;
1300     }
1301 
1302     // handle BT initialization
1303     if (hci_stack->state == HCI_STATE_INITIALIZING){
1304         hci_initializing_event_handler(packet, size);
1305     }
1306 
1307     // help with BT sleep
1308     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1309         && hci_stack->substate == 1
1310         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1311         hci_stack->substate++;
1312     }
1313 
1314     // notify upper stack
1315     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1316 
1317     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1318     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1319         if (!packet[2]){
1320             handle = READ_BT_16(packet, 3);
1321             hci_connection_t * conn = hci_connection_for_handle(handle);
1322             if (conn) {
1323                 uint8_t status = conn->bonding_status;
1324                 bd_addr_t bd_address;
1325                 memcpy(&bd_address, conn->address, 6);
1326                 hci_shutdown_connection(conn);
1327                 if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1328                     hci_emit_dedicated_bonding_result(bd_address, status);
1329                 }
1330             }
1331         }
1332     }
1333 
1334 	// execute main loop
1335 	hci_run();
1336 }
1337 
1338 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1339     switch (packet_type) {
1340         case HCI_EVENT_PACKET:
1341             event_handler(packet, size);
1342             break;
1343         case HCI_ACL_DATA_PACKET:
1344             acl_handler(packet, size);
1345             break;
1346         default:
1347             break;
1348     }
1349 }
1350 
1351 /** Register HCI packet handlers */
1352 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1353     hci_stack->packet_handler = handler;
1354 }
1355 
1356 static void hci_state_reset(){
1357     // no connections yet
1358     hci_stack->connections = NULL;
1359 
1360     // keep discoverable/connectable as this has been requested by the client(s)
1361     // hci_stack->discoverable = 0;
1362     // hci_stack->connectable = 0;
1363     // hci_stack->bondable = 1;
1364 
1365     // buffer is free
1366     hci_stack->hci_packet_buffer_reserved = 0;
1367 
1368     // no pending cmds
1369     hci_stack->decline_reason = 0;
1370     hci_stack->new_scan_enable_value = 0xff;
1371 
1372     // LE
1373     hci_stack->adv_addr_type = 0;
1374     memset(hci_stack->adv_address, 0, 6);
1375     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1376     hci_stack->le_scan_type = 0xff;
1377 }
1378 
1379 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1380 
1381 #ifdef HAVE_MALLOC
1382     if (!hci_stack) {
1383         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1384     }
1385 #else
1386     hci_stack = &hci_stack_static;
1387 #endif
1388     memset(hci_stack, 0, sizeof(hci_stack_t));
1389 
1390     // reference to use transport layer implementation
1391     hci_stack->hci_transport = transport;
1392 
1393     // references to used control implementation
1394     hci_stack->control = control;
1395 
1396     // reference to used config
1397     hci_stack->config = config;
1398 
1399     // higher level handler
1400     hci_stack->packet_handler = dummy_handler;
1401 
1402     // store and open remote device db
1403     hci_stack->remote_device_db = remote_device_db;
1404     if (hci_stack->remote_device_db) {
1405         hci_stack->remote_device_db->open();
1406     }
1407 
1408     // max acl payload size defined in config.h
1409     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1410 
1411     // register packet handlers with transport
1412     transport->register_packet_handler(&packet_handler);
1413 
1414     hci_stack->state = HCI_STATE_OFF;
1415 
1416     // class of device
1417     hci_stack->class_of_device = 0x007a020c; // Smartphone
1418 
1419     // bondable by default
1420     hci_stack->bondable = 1;
1421 
1422     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1423     hci_stack->ssp_enable = 1;
1424     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1425     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1426     hci_stack->ssp_auto_accept = 1;
1427 
1428     hci_state_reset();
1429 }
1430 
1431 void hci_close(){
1432     // close remote device db
1433     if (hci_stack->remote_device_db) {
1434         hci_stack->remote_device_db->close();
1435     }
1436     while (hci_stack->connections) {
1437         // cancel all l2cap connections
1438         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1439         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1440     }
1441     hci_power_control(HCI_POWER_OFF);
1442 
1443 #ifdef HAVE_MALLOC
1444     free(hci_stack);
1445 #endif
1446     hci_stack = NULL;
1447 }
1448 
1449 void hci_set_class_of_device(uint32_t class_of_device){
1450     hci_stack->class_of_device = class_of_device;
1451 }
1452 
1453 void hci_disable_l2cap_timeout_check(){
1454     disable_l2cap_timeouts = 1;
1455 }
1456 // State-Module-Driver overview
1457 // state                    module  low-level
1458 // HCI_STATE_OFF             off      close
1459 // HCI_STATE_INITIALIZING,   on       open
1460 // HCI_STATE_WORKING,        on       open
1461 // HCI_STATE_HALTING,        on       open
1462 // HCI_STATE_SLEEPING,    off/sleep   close
1463 // HCI_STATE_FALLING_ASLEEP  on       open
1464 
1465 static int hci_power_control_on(void){
1466 
1467     // power on
1468     int err = 0;
1469     if (hci_stack->control && hci_stack->control->on){
1470         err = (*hci_stack->control->on)(hci_stack->config);
1471     }
1472     if (err){
1473         log_error( "POWER_ON failed");
1474         hci_emit_hci_open_failed();
1475         return err;
1476     }
1477 
1478     // open low-level device
1479     err = hci_stack->hci_transport->open(hci_stack->config);
1480     if (err){
1481         log_error( "HCI_INIT failed, turning Bluetooth off again");
1482         if (hci_stack->control && hci_stack->control->off){
1483             (*hci_stack->control->off)(hci_stack->config);
1484         }
1485         hci_emit_hci_open_failed();
1486         return err;
1487     }
1488     return 0;
1489 }
1490 
1491 static void hci_power_control_off(void){
1492 
1493     log_info("hci_power_control_off");
1494 
1495     // close low-level device
1496     hci_stack->hci_transport->close(hci_stack->config);
1497 
1498     log_info("hci_power_control_off - hci_transport closed");
1499 
1500     // power off
1501     if (hci_stack->control && hci_stack->control->off){
1502         (*hci_stack->control->off)(hci_stack->config);
1503     }
1504 
1505     log_info("hci_power_control_off - control closed");
1506 
1507     hci_stack->state = HCI_STATE_OFF;
1508 }
1509 
1510 static void hci_power_control_sleep(void){
1511 
1512     log_info("hci_power_control_sleep");
1513 
1514 #if 0
1515     // don't close serial port during sleep
1516 
1517     // close low-level device
1518     hci_stack->hci_transport->close(hci_stack->config);
1519 #endif
1520 
1521     // sleep mode
1522     if (hci_stack->control && hci_stack->control->sleep){
1523         (*hci_stack->control->sleep)(hci_stack->config);
1524     }
1525 
1526     hci_stack->state = HCI_STATE_SLEEPING;
1527 }
1528 
1529 static int hci_power_control_wake(void){
1530 
1531     log_info("hci_power_control_wake");
1532 
1533     // wake on
1534     if (hci_stack->control && hci_stack->control->wake){
1535         (*hci_stack->control->wake)(hci_stack->config);
1536     }
1537 
1538 #if 0
1539     // open low-level device
1540     int err = hci_stack->hci_transport->open(hci_stack->config);
1541     if (err){
1542         log_error( "HCI_INIT failed, turning Bluetooth off again");
1543         if (hci_stack->control && hci_stack->control->off){
1544             (*hci_stack->control->off)(hci_stack->config);
1545         }
1546         hci_emit_hci_open_failed();
1547         return err;
1548     }
1549 #endif
1550 
1551     return 0;
1552 }
1553 
1554 static void hci_power_transition_to_initializing(void){
1555     // set up state machine
1556     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1557     hci_stack->hci_packet_buffer_reserved = 0;
1558     hci_stack->state = HCI_STATE_INITIALIZING;
1559     hci_stack->substate = 0;
1560 }
1561 
1562 int hci_power_control(HCI_POWER_MODE power_mode){
1563 
1564     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1565 
1566     int err = 0;
1567     switch (hci_stack->state){
1568 
1569         case HCI_STATE_OFF:
1570             switch (power_mode){
1571                 case HCI_POWER_ON:
1572                     err = hci_power_control_on();
1573                     if (err) {
1574                         log_error("hci_power_control_on() error %u", err);
1575                         return err;
1576                     }
1577                     hci_power_transition_to_initializing();
1578                     break;
1579                 case HCI_POWER_OFF:
1580                     // do nothing
1581                     break;
1582                 case HCI_POWER_SLEEP:
1583                     // do nothing (with SLEEP == OFF)
1584                     break;
1585             }
1586             break;
1587 
1588         case HCI_STATE_INITIALIZING:
1589             switch (power_mode){
1590                 case HCI_POWER_ON:
1591                     // do nothing
1592                     break;
1593                 case HCI_POWER_OFF:
1594                     // no connections yet, just turn it off
1595                     hci_power_control_off();
1596                     break;
1597                 case HCI_POWER_SLEEP:
1598                     // no connections yet, just turn it off
1599                     hci_power_control_sleep();
1600                     break;
1601             }
1602             break;
1603 
1604         case HCI_STATE_WORKING:
1605             switch (power_mode){
1606                 case HCI_POWER_ON:
1607                     // do nothing
1608                     break;
1609                 case HCI_POWER_OFF:
1610                     // see hci_run
1611                     hci_stack->state = HCI_STATE_HALTING;
1612                     break;
1613                 case HCI_POWER_SLEEP:
1614                     // see hci_run
1615                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1616                     hci_stack->substate = 0;
1617                     break;
1618             }
1619             break;
1620 
1621         case HCI_STATE_HALTING:
1622             switch (power_mode){
1623                 case HCI_POWER_ON:
1624                     hci_power_transition_to_initializing();
1625                     break;
1626                 case HCI_POWER_OFF:
1627                     // do nothing
1628                     break;
1629                 case HCI_POWER_SLEEP:
1630                     // see hci_run
1631                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1632                     hci_stack->substate = 0;
1633                     break;
1634             }
1635             break;
1636 
1637         case HCI_STATE_FALLING_ASLEEP:
1638             switch (power_mode){
1639                 case HCI_POWER_ON:
1640 
1641 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1642                     // nothing to do, if H4 supports power management
1643                     if (bt_control_iphone_power_management_enabled()){
1644                         hci_stack->state = HCI_STATE_INITIALIZING;
1645                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1646                         break;
1647                     }
1648 #endif
1649                     hci_power_transition_to_initializing();
1650                     break;
1651                 case HCI_POWER_OFF:
1652                     // see hci_run
1653                     hci_stack->state = HCI_STATE_HALTING;
1654                     break;
1655                 case HCI_POWER_SLEEP:
1656                     // do nothing
1657                     break;
1658             }
1659             break;
1660 
1661         case HCI_STATE_SLEEPING:
1662             switch (power_mode){
1663                 case HCI_POWER_ON:
1664 
1665 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1666                     // nothing to do, if H4 supports power management
1667                     if (bt_control_iphone_power_management_enabled()){
1668                         hci_stack->state = HCI_STATE_INITIALIZING;
1669                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1670                         hci_update_scan_enable();
1671                         break;
1672                     }
1673 #endif
1674                     err = hci_power_control_wake();
1675                     if (err) return err;
1676                     hci_power_transition_to_initializing();
1677                     break;
1678                 case HCI_POWER_OFF:
1679                     hci_stack->state = HCI_STATE_HALTING;
1680                     break;
1681                 case HCI_POWER_SLEEP:
1682                     // do nothing
1683                     break;
1684             }
1685             break;
1686     }
1687 
1688     // create internal event
1689 	hci_emit_state();
1690 
1691 	// trigger next/first action
1692 	hci_run();
1693 
1694     return 0;
1695 }
1696 
1697 static void hci_update_scan_enable(void){
1698     // 2 = page scan, 1 = inq scan
1699     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1700     hci_run();
1701 }
1702 
1703 void hci_discoverable_control(uint8_t enable){
1704     if (enable) enable = 1; // normalize argument
1705 
1706     if (hci_stack->discoverable == enable){
1707         hci_emit_discoverable_enabled(hci_stack->discoverable);
1708         return;
1709     }
1710 
1711     hci_stack->discoverable = enable;
1712     hci_update_scan_enable();
1713 }
1714 
1715 void hci_connectable_control(uint8_t enable){
1716     if (enable) enable = 1; // normalize argument
1717 
1718     // don't emit event
1719     if (hci_stack->connectable == enable) return;
1720 
1721     hci_stack->connectable = enable;
1722     hci_update_scan_enable();
1723 }
1724 
1725 bd_addr_t * hci_local_bd_addr(void){
1726     return &hci_stack->local_bd_addr;
1727 }
1728 
1729 void hci_run(){
1730 
1731     hci_connection_t * connection;
1732     linked_item_t * it;
1733 
1734     if (!hci_can_send_command_packet_now()) return;
1735 
1736     // global/non-connection oriented commands
1737 
1738     // decline incoming connections
1739     if (hci_stack->decline_reason){
1740         uint8_t reason = hci_stack->decline_reason;
1741         hci_stack->decline_reason = 0;
1742         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1743         return;
1744     }
1745 
1746     // send scan enable
1747     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1748         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1749         hci_stack->new_scan_enable_value = 0xff;
1750         return;
1751     }
1752 
1753 #ifdef HAVE_BLE
1754     // handle le scan
1755     if (hci_stack->state == HCI_STATE_WORKING){
1756         switch(hci_stack->le_scanning_state){
1757             case LE_START_SCAN:
1758                 hci_stack->le_scanning_state = LE_SCANNING;
1759                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1760                 return;
1761 
1762             case LE_STOP_SCAN:
1763                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1764                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1765                 return;
1766             default:
1767                 break;
1768         }
1769         if (hci_stack->le_scan_type != 0xff){
1770             // defaults: active scanning, accept all advertisement packets
1771             int scan_type = hci_stack->le_scan_type;
1772             hci_stack->le_scan_type = 0xff;
1773             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);
1774             return;
1775         }
1776     }
1777 #endif
1778 
1779     // send pending HCI commands
1780     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1781         connection = (hci_connection_t *) it;
1782 
1783         switch(connection->state){
1784             case SEND_CREATE_CONNECTION:
1785                 switch(connection->address_type){
1786                     case BD_ADDR_TYPE_CLASSIC:
1787                         log_info("sending hci_create_connection");
1788                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1789                         break;
1790                     default:
1791 #ifdef HAVE_BLE
1792                         log_info("sending hci_le_create_connection");
1793                         hci_send_cmd(&hci_le_create_connection,
1794                                      0x0060,    // scan interval: 60 ms
1795                                      0x0030,    // scan interval: 30 ms
1796                                      0,         // don't use whitelist
1797                                      connection->address_type, // peer address type
1798                                      connection->address,      // peer bd addr
1799                                      hci_stack->adv_addr_type, // our addr type:
1800                                      0x0008,    // conn interval min
1801                                      0x0018,    // conn interval max
1802                                      0,         // conn latency
1803                                      0x0048,    // supervision timeout
1804                                      0x0001,    // min ce length
1805                                      0x0001     // max ce length
1806                                      );
1807 
1808                         connection->state = SENT_CREATE_CONNECTION;
1809 #endif
1810                         break;
1811                 }
1812                 return;
1813 
1814             case RECEIVED_CONNECTION_REQUEST:
1815                 log_info("sending hci_accept_connection_request");
1816                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1817                 hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1818                 return;
1819 
1820 #ifdef HAVE_BLE
1821             case SEND_CANCEL_CONNECTION:
1822                 connection->state = SENT_CANCEL_CONNECTION;
1823                 hci_send_cmd(&hci_le_create_connection_cancel);
1824                 return;
1825 #endif
1826             case SEND_DISCONNECT:
1827                 connection->state = SENT_DISCONNECT;
1828                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
1829                 return;
1830 
1831             default:
1832                 break;
1833         }
1834 
1835         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1836             log_info("responding to link key request");
1837             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1838             link_key_t link_key;
1839             link_key_type_t link_key_type;
1840             if ( hci_stack->remote_device_db
1841               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
1842               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
1843                connection->link_key_type = link_key_type;
1844                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1845             } else {
1846                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1847             }
1848             return;
1849         }
1850 
1851         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
1852             log_info("denying to pin request");
1853             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
1854             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1855             return;
1856         }
1857 
1858         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1859             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1860             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
1861             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
1862                 // tweak authentication requirements
1863                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
1864                 if (connection->bonding_flags & BONDING_DEDICATED){
1865                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
1866                 }
1867                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
1868                     authreq |= 1;
1869                 }
1870                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
1871             } else {
1872                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1873             }
1874             return;
1875         }
1876 
1877         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1878             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1879             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1880             return;
1881         }
1882 
1883         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1884             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1885             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1886             return;
1887         }
1888 
1889         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1890             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1891             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1892             return;
1893         }
1894 
1895         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
1896             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
1897             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
1898             return;
1899         }
1900         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
1901             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
1902             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
1903             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
1904             return;
1905         }
1906         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
1907             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
1908             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
1909             return;
1910         }
1911         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
1912             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
1913             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
1914             return;
1915         }
1916 #ifdef HAVE_BLE
1917         if (connection->le_conn_interval_min){
1918             uint16_t connection_interval_min = connection->le_conn_interval_min;
1919             connection->le_conn_interval_min = 0;
1920             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
1921                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
1922                 0x0000, 0xffff);
1923         }
1924 #endif
1925     }
1926 
1927     // send continuation fragments
1928     if (hci_stack->acl_fragmentation_total_size > 0) {
1929         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1930         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1931             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1932             if (connection) {
1933                 hci_send_acl_packet_fragments(connection);
1934                 return;
1935             }
1936             // connection gone -> discard further fragments
1937             hci_stack->acl_fragmentation_total_size = 0;
1938             hci_stack->acl_fragmentation_pos = 0;
1939         }
1940     }
1941 
1942     switch (hci_stack->state){
1943         case HCI_STATE_INITIALIZING:
1944             hci_initializing_state_machine();
1945             break;
1946 
1947         case HCI_STATE_HALTING:
1948 
1949             log_info("HCI_STATE_HALTING");
1950             // close all open connections
1951             connection =  (hci_connection_t *) hci_stack->connections;
1952             if (connection){
1953 
1954                 // send disconnect
1955                 if (!hci_can_send_command_packet_now()) return;
1956 
1957                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
1958                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1959 
1960                 // send disconnected event right away - causes higher layer connections to get closed, too.
1961                 hci_shutdown_connection(connection);
1962                 return;
1963             }
1964             log_info("HCI_STATE_HALTING, calling off");
1965 
1966             // switch mode
1967             hci_power_control_off();
1968 
1969             log_info("HCI_STATE_HALTING, emitting state");
1970             hci_emit_state();
1971             log_info("HCI_STATE_HALTING, done");
1972             break;
1973 
1974         case HCI_STATE_FALLING_ASLEEP:
1975             switch(hci_stack->substate) {
1976                 case 0:
1977                     log_info("HCI_STATE_FALLING_ASLEEP");
1978                     // close all open connections
1979                     connection =  (hci_connection_t *) hci_stack->connections;
1980 
1981 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1982                     // don't close connections, if H4 supports power management
1983                     if (bt_control_iphone_power_management_enabled()){
1984                         connection = NULL;
1985                     }
1986 #endif
1987                     if (connection){
1988 
1989                         // send disconnect
1990                         if (!hci_can_send_command_packet_now()) return;
1991 
1992                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
1993                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1994 
1995                         // send disconnected event right away - causes higher layer connections to get closed, too.
1996                         hci_shutdown_connection(connection);
1997                         return;
1998                     }
1999 
2000                     if (hci_classic_supported()){
2001                         // disable page and inquiry scan
2002                         if (!hci_can_send_command_packet_now()) return;
2003 
2004                         log_info("HCI_STATE_HALTING, disabling inq scans");
2005                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
2006 
2007                         // continue in next sub state
2008                         hci_stack->substate++;
2009                         break;
2010                     }
2011                     // fall through for ble-only chips
2012 
2013                 case 2:
2014                     log_info("HCI_STATE_HALTING, calling sleep");
2015 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2016                     // don't actually go to sleep, if H4 supports power management
2017                     if (bt_control_iphone_power_management_enabled()){
2018                         // SLEEP MODE reached
2019                         hci_stack->state = HCI_STATE_SLEEPING;
2020                         hci_emit_state();
2021                         break;
2022                     }
2023 #endif
2024                     // switch mode
2025                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2026                     hci_emit_state();
2027                     break;
2028 
2029                 default:
2030                     break;
2031             }
2032             break;
2033 
2034         default:
2035             break;
2036     }
2037 }
2038 
2039 int hci_send_cmd_packet(uint8_t *packet, int size){
2040     bd_addr_t addr;
2041     hci_connection_t * conn;
2042     // house-keeping
2043 
2044     // create_connection?
2045     if (IS_COMMAND(packet, hci_create_connection)){
2046         bt_flip_addr(addr, &packet[3]);
2047         log_info("Create_connection to %s", bd_addr_to_str(addr));
2048 
2049         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2050         if (!conn){
2051             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2052             if (!conn){
2053                 // notify client that alloc failed
2054                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2055                 return 0; // don't sent packet to controller
2056             }
2057             conn->state = SEND_CREATE_CONNECTION;
2058         }
2059         log_info("conn state %u", conn->state);
2060         switch (conn->state){
2061             // if connection active exists
2062             case OPEN:
2063                 // and OPEN, emit connection complete command, don't send to controller
2064                 hci_emit_connection_complete(conn, 0);
2065                 return 0;
2066             case SEND_CREATE_CONNECTION:
2067                 // connection created by hci, e.g. dedicated bonding
2068                 break;
2069             default:
2070                 // otherwise, just ignore as it is already in the open process
2071                 return 0;
2072         }
2073         conn->state = SENT_CREATE_CONNECTION;
2074     }
2075 
2076     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2077         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2078     }
2079     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2080         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2081     }
2082 
2083     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2084         if (hci_stack->remote_device_db){
2085             bt_flip_addr(addr, &packet[3]);
2086             hci_stack->remote_device_db->delete_link_key(&addr);
2087         }
2088     }
2089 
2090     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2091     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2092         bt_flip_addr(addr, &packet[3]);
2093         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2094         if (conn){
2095             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2096         }
2097     }
2098 
2099     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2100     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2101     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2102     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2103         bt_flip_addr(addr, &packet[3]);
2104         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2105         if (conn){
2106             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2107         }
2108     }
2109 
2110 #ifdef HAVE_BLE
2111     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2112         hci_stack->adv_addr_type = packet[8];
2113     }
2114     if (IS_COMMAND(packet, hci_le_set_random_address)){
2115         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2116     }
2117 #endif
2118 
2119     hci_stack->num_cmd_packets--;
2120     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2121 
2122     // free packet buffer for synchronous transport implementations
2123     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2124         hci_stack->hci_packet_buffer_reserved = 0;
2125     }
2126 
2127     return err;
2128 }
2129 
2130 // disconnect because of security block
2131 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2132     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2133     if (!connection) return;
2134     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2135 }
2136 
2137 
2138 // Configure Secure Simple Pairing
2139 
2140 // enable will enable SSP during init
2141 void hci_ssp_set_enable(int enable){
2142     hci_stack->ssp_enable = enable;
2143 }
2144 
2145 int hci_local_ssp_activated(){
2146     return hci_ssp_supported() && hci_stack->ssp_enable;
2147 }
2148 
2149 // if set, BTstack will respond to io capability request using authentication requirement
2150 void hci_ssp_set_io_capability(int io_capability){
2151     hci_stack->ssp_io_capability = io_capability;
2152 }
2153 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2154     hci_stack->ssp_authentication_requirement = authentication_requirement;
2155 }
2156 
2157 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2158 void hci_ssp_set_auto_accept(int auto_accept){
2159     hci_stack->ssp_auto_accept = auto_accept;
2160 }
2161 
2162 /**
2163  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2164  */
2165 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2166 
2167     if (!hci_can_send_command_packet_now()){
2168         log_error("hci_send_cmd called but cannot send packet now");
2169         return 0;
2170     }
2171 
2172     // for HCI INITIALIZATION
2173     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2174     hci_stack->last_cmd_opcode = cmd->opcode;
2175 
2176     hci_reserve_packet_buffer();
2177     uint8_t * packet = hci_stack->hci_packet_buffer;
2178 
2179     va_list argptr;
2180     va_start(argptr, cmd);
2181     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2182     va_end(argptr);
2183 
2184     return hci_send_cmd_packet(packet, size);
2185 }
2186 
2187 // Create various non-HCI events.
2188 // TODO: generalize, use table similar to hci_create_command
2189 
2190 void hci_emit_state(){
2191     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2192     uint8_t event[3];
2193     event[0] = BTSTACK_EVENT_STATE;
2194     event[1] = sizeof(event) - 2;
2195     event[2] = hci_stack->state;
2196     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2197     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2198 }
2199 
2200 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2201     uint8_t event[13];
2202     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2203     event[1] = sizeof(event) - 2;
2204     event[2] = status;
2205     bt_store_16(event, 3, conn->con_handle);
2206     bt_flip_addr(&event[5], conn->address);
2207     event[11] = 1; // ACL connection
2208     event[12] = 0; // encryption disabled
2209     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2210     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2211 }
2212 
2213 void hci_emit_le_connection_complete(hci_connection_t *conn, uint8_t status){
2214     uint8_t event[21];
2215     event[0] = HCI_EVENT_LE_META;
2216     event[1] = sizeof(event) - 2;
2217     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2218     event[3] = status;
2219     bt_store_16(event, 4, conn->con_handle);
2220     event[6] = 0; // TODO: role
2221     event[7] = conn->address_type;
2222     bt_flip_addr(&event[8], conn->address);
2223     bt_store_16(event, 14, 0); // interval
2224     bt_store_16(event, 16, 0); // latency
2225     bt_store_16(event, 18, 0); // supervision timeout
2226     event[20] = 0; // master clock accuracy
2227     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2228     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2229 }
2230 
2231 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2232     uint8_t event[6];
2233     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2234     event[1] = sizeof(event) - 2;
2235     event[2] = 0; // status = OK
2236     bt_store_16(event, 3, handle);
2237     event[5] = reason;
2238     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2239     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2240 }
2241 
2242 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2243     if (disable_l2cap_timeouts) return;
2244     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2245     uint8_t event[4];
2246     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2247     event[1] = sizeof(event) - 2;
2248     bt_store_16(event, 2, conn->con_handle);
2249     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2250     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2251 }
2252 
2253 void hci_emit_nr_connections_changed(){
2254     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2255     uint8_t event[3];
2256     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2257     event[1] = sizeof(event) - 2;
2258     event[2] = nr_hci_connections();
2259     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2260     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2261 }
2262 
2263 void hci_emit_hci_open_failed(){
2264     log_info("BTSTACK_EVENT_POWERON_FAILED");
2265     uint8_t event[2];
2266     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2267     event[1] = sizeof(event) - 2;
2268     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2269     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2270 }
2271 
2272 #ifndef EMBEDDED
2273 void hci_emit_btstack_version() {
2274     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2275     uint8_t event[6];
2276     event[0] = BTSTACK_EVENT_VERSION;
2277     event[1] = sizeof(event) - 2;
2278     event[2] = BTSTACK_MAJOR;
2279     event[3] = BTSTACK_MINOR;
2280     bt_store_16(event, 4, BTSTACK_REVISION);
2281     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2282     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2283 }
2284 #endif
2285 
2286 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2287     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2288     uint8_t event[3];
2289     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2290     event[1] = sizeof(event) - 2;
2291     event[2] = enabled;
2292     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2293     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2294 }
2295 
2296 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
2297     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2298     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2299     event[1] = sizeof(event) - 2 - 1;
2300     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2301     bt_flip_addr(&event[3], *addr);
2302     memcpy(&event[9], name, 248);
2303 
2304     event[9+248] = 0;   // assert \0 for log_info
2305     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
2306 
2307     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2308     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2309 }
2310 
2311 void hci_emit_discoverable_enabled(uint8_t enabled){
2312     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2313     uint8_t event[3];
2314     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2315     event[1] = sizeof(event) - 2;
2316     event[2] = enabled;
2317     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2318     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2319 }
2320 
2321 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2322     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2323     uint8_t event[5];
2324     int pos = 0;
2325     event[pos++] = GAP_SECURITY_LEVEL;
2326     event[pos++] = sizeof(event) - 2;
2327     bt_store_16(event, 2, con_handle);
2328     pos += 2;
2329     event[pos++] = level;
2330     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2331     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2332 }
2333 
2334 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2335     log_info("hci_emit_dedicated_bonding_result %u ", status);
2336     uint8_t event[9];
2337     int pos = 0;
2338     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2339     event[pos++] = sizeof(event) - 2;
2340     event[pos++] = status;
2341     bt_flip_addr( * (bd_addr_t *) &event[pos], address);
2342     pos += 6;
2343     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2344     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2345 }
2346 
2347 // query if remote side supports SSP
2348 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2349     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2350     if (!connection) return 0;
2351     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2352 }
2353 
2354 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2355     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2356 }
2357 
2358 // GAP API
2359 /**
2360  * @bbrief enable/disable bonding. default is enabled
2361  * @praram enabled
2362  */
2363 void gap_set_bondable_mode(int enable){
2364     hci_stack->bondable = enable ? 1 : 0;
2365 }
2366 
2367 /**
2368  * @brief map link keys to security levels
2369  */
2370 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2371     switch (link_key_type){
2372         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2373             return LEVEL_4;
2374         case COMBINATION_KEY:
2375         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2376             return LEVEL_3;
2377         default:
2378             return LEVEL_2;
2379     }
2380 }
2381 
2382 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2383     if (!connection) return LEVEL_0;
2384     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2385     return gap_security_level_for_link_key_type(connection->link_key_type);
2386 }
2387 
2388 
2389 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2390     log_info("gap_mitm_protection_required_for_security_level %u", level);
2391     return level > LEVEL_2;
2392 }
2393 
2394 /**
2395  * @brief get current security level
2396  */
2397 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2398     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2399     if (!connection) return LEVEL_0;
2400     return gap_security_level_for_connection(connection);
2401 }
2402 
2403 /**
2404  * @brief request connection to device to
2405  * @result GAP_AUTHENTICATION_RESULT
2406  */
2407 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2408     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2409     if (!connection){
2410         hci_emit_security_level(con_handle, LEVEL_0);
2411         return;
2412     }
2413     gap_security_level_t current_level = gap_security_level(con_handle);
2414     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2415     if (current_level >= requested_level){
2416         hci_emit_security_level(con_handle, current_level);
2417         return;
2418     }
2419 
2420     connection->requested_security_level = requested_level;
2421 
2422     // would enabling ecnryption suffice (>= LEVEL_2)?
2423     if (hci_stack->remote_device_db){
2424         link_key_type_t link_key_type;
2425         link_key_t      link_key;
2426         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2427             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2428                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2429                 return;
2430             }
2431         }
2432     }
2433 
2434     // try to authenticate connection
2435     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2436     hci_run();
2437 }
2438 
2439 /**
2440  * @brief start dedicated bonding with device. disconnect after bonding
2441  * @param device
2442  * @param request MITM protection
2443  * @result GAP_DEDICATED_BONDING_COMPLETE
2444  */
2445 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2446 
2447     // create connection state machine
2448     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2449 
2450     if (!connection){
2451         return BTSTACK_MEMORY_ALLOC_FAILED;
2452     }
2453 
2454     // delete linkn key
2455     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2456 
2457     // configure LEVEL_2/3, dedicated bonding
2458     connection->state = SEND_CREATE_CONNECTION;
2459     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2460     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2461     connection->bonding_flags = BONDING_DEDICATED;
2462 
2463     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2464 
2465     // handle: connnection failure (connection complete != ok)
2466     // handle: authentication failure
2467     // handle: disconnect on done
2468 
2469     hci_run();
2470 
2471     return 0;
2472 }
2473 
2474 void gap_set_local_name(const char * local_name){
2475     hci_stack->local_name = local_name;
2476 }
2477 
2478 le_command_status_t le_central_start_scan(){
2479     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2480     hci_stack->le_scanning_state = LE_START_SCAN;
2481     hci_run();
2482     return BLE_PERIPHERAL_OK;
2483 }
2484 
2485 le_command_status_t le_central_stop_scan(){
2486     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2487     hci_stack->le_scanning_state = LE_STOP_SCAN;
2488     hci_run();
2489     return BLE_PERIPHERAL_OK;
2490 }
2491 
2492 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2493     hci_stack->le_scan_type     = scan_type;
2494     hci_stack->le_scan_interval = scan_interval;
2495     hci_stack->le_scan_window   = scan_window;
2496     hci_run();
2497 }
2498 
2499 le_command_status_t le_central_connect(bd_addr_t * addr, bd_addr_type_t addr_type){
2500     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2501     if (!conn){
2502         log_info("le_central_connect: no connection exists yet, creating context");
2503         conn = create_connection_for_bd_addr_and_type(*addr, addr_type);
2504         if (!conn){
2505             // notify client that alloc failed
2506             hci_emit_le_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2507             log_info("le_central_connect: failed to alloc context");
2508             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2509         }
2510         conn->state = SEND_CREATE_CONNECTION;
2511         log_info("le_central_connect: send create connection next");
2512         hci_run();
2513         return BLE_PERIPHERAL_OK;
2514     }
2515 
2516     if (!hci_is_le_connection(conn) ||
2517         conn->state == SEND_CREATE_CONNECTION ||
2518         conn->state == SENT_CREATE_CONNECTION) {
2519         hci_emit_le_connection_complete(conn, ERROR_CODE_COMMAND_DISALLOWED);
2520         log_error("le_central_connect: classic connection or connect is already being created");
2521         return BLE_PERIPHERAL_IN_WRONG_STATE;
2522     }
2523 
2524     log_info("le_central_connect: context exists with state %u", conn->state);
2525     hci_emit_le_connection_complete(conn, 0);
2526     hci_run();
2527     return BLE_PERIPHERAL_OK;
2528 }
2529 
2530 // @assumption: only a single outgoing LE Connection exists
2531 static hci_connection_t * le_central_get_outgoing_connection(){
2532     linked_item_t *it;
2533     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2534         hci_connection_t * conn = (hci_connection_t *) it;
2535         if (!hci_is_le_connection(conn)) continue;
2536         switch (conn->state){
2537             case SEND_CREATE_CONNECTION:
2538             case SENT_CREATE_CONNECTION:
2539                 return conn;
2540             default:
2541                 break;
2542         };
2543     }
2544     return NULL;
2545 }
2546 
2547 le_command_status_t le_central_connect_cancel(){
2548     hci_connection_t * conn = le_central_get_outgoing_connection();
2549     switch (conn->state){
2550         case SEND_CREATE_CONNECTION:
2551             // skip sending create connection and emit event instead
2552             hci_emit_le_connection_complete(conn, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2553             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2554             btstack_memory_hci_connection_free( conn );
2555             break;
2556         case SENT_CREATE_CONNECTION:
2557             // request to send cancel connection
2558             conn->state = SEND_CANCEL_CONNECTION;
2559             hci_run();
2560             break;
2561         default:
2562             break;
2563     }
2564     return BLE_PERIPHERAL_OK;
2565 }
2566 
2567 /**
2568  * @brief Updates the connection parameters for a given LE connection
2569  * @param handle
2570  * @param conn_interval_min (unit: 1.25ms)
2571  * @param conn_interval_max (unit: 1.25ms)
2572  * @param conn_latency
2573  * @param supervision_timeout (unit: 10ms)
2574  * @returns 0 if ok
2575  */
2576 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2577     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2578     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2579     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2580     connection->le_conn_interval_min = conn_interval_min;
2581     connection->le_conn_interval_max = conn_interval_max;
2582     connection->le_conn_latency = conn_latency;
2583     connection->le_supervision_timeout = supervision_timeout;
2584     return 0;
2585 }
2586 
2587 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2588     hci_connection_t * conn = hci_connection_for_handle(handle);
2589     if (!conn){
2590         hci_emit_disconnection_complete(handle, 0);
2591         return BLE_PERIPHERAL_OK;
2592     }
2593     conn->state = SEND_DISCONNECT;
2594     hci_run();
2595     return BLE_PERIPHERAL_OK;
2596 }
2597 
2598 void hci_disconnect_all(){
2599     linked_list_iterator_t it;
2600     linked_list_iterator_init(&it, &hci_stack->connections);
2601     while (linked_list_iterator_has_next(&it)){
2602         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2603         if (con->state == SENT_DISCONNECT) continue;
2604         con->state = SEND_DISCONNECT;
2605     }
2606     hci_run();
2607 }
2608