xref: /btstack/src/hci.c (revision 452cf3bbef65d5b81b69306bd34b32156550853d)
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 static int hci_send_acl_packet_fragments(hci_connection_t *connection){
388 
389     // 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);
390 
391     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
392     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
393     if (hci_is_le_connection(connection) && hci_stack->le_data_packets_length > 0){
394         max_acl_data_packet_length = hci_stack->le_data_packets_length;
395     }
396 
397     // testing: reduce buffer to minimum
398     // max_acl_data_packet_length = 52;
399 
400     int err;
401     // multiple packets could be send on a synchronous HCI transport
402     while (1){
403 
404         // get current data
405         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4;
406         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
407         int more_fragments = 0;
408 
409         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
410         if (current_acl_data_packet_length > max_acl_data_packet_length){
411             more_fragments = 1;
412             current_acl_data_packet_length = max_acl_data_packet_length;
413         }
414 
415         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
416         if (acl_header_pos > 0){
417             uint16_t handle_and_flags = READ_BT_16(hci_stack->hci_packet_buffer, 0);
418             handle_and_flags = (handle_and_flags & 0xcfff) | (1 << 12);
419             bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
420         }
421 
422         // update header len
423         bt_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2, current_acl_data_packet_length);
424 
425         // count packet
426         connection->num_acl_packets_sent++;
427 
428         // send packet
429         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
430         const int size = current_acl_data_packet_length + 4;
431         // hexdump(packet, size);
432         err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
433 
434         // done yet?
435         if (!more_fragments) break;
436 
437         // update start of next fragment to send
438         hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
439 
440         // can send more?
441         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return err;
442     }
443 
444     // done
445     hci_stack->acl_fragmentation_pos = 0;
446     hci_stack->acl_fragmentation_total_size = 0;
447 
448     // free buffer now for synchronous transport
449     if (!hci_transport_synchronous()){
450         hci_release_packet_buffer();
451     }
452 
453     return err;
454 }
455 
456 // pre: caller has reserved the packet buffer
457 int hci_send_acl_packet_buffer(int size){
458 
459     // log_info("hci_send_acl_packet_buffer size %u", size);
460 
461     if (!hci_stack->hci_packet_buffer_reserved) {
462         log_error("hci_send_acl_packet_buffer called without reserving packet buffer");
463         return 0;
464     }
465 
466     uint8_t * packet = hci_stack->hci_packet_buffer;
467     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
468 
469     // check for free places on Bluetooth module
470     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
471         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
472         hci_release_packet_buffer();
473         return BTSTACK_ACL_BUFFERS_FULL;
474     }
475 
476     hci_connection_t *connection = hci_connection_for_handle( con_handle);
477     if (!connection) {
478         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
479         hci_release_packet_buffer();
480         return 0;
481     }
482     hci_connection_timestamp(connection);
483 
484     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
485 
486     // setup data
487     hci_stack->acl_fragmentation_total_size = size;
488     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
489 
490     return hci_send_acl_packet_fragments(connection);
491 }
492 
493 static void acl_handler(uint8_t *packet, int size){
494 
495     // log_info("acl_handler: size %u", size);
496 
497     // get info
498     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
499     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
500     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
501     uint16_t acl_length         = READ_ACL_LENGTH(packet);
502 
503     // ignore non-registered handle
504     if (!conn){
505         log_error( "hci.c: acl_handler called with non-registered handle %u!" , con_handle);
506         return;
507     }
508 
509     // assert packet is complete
510     if (acl_length + 4 != size){
511         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
512         return;
513     }
514 
515     // update idle timestamp
516     hci_connection_timestamp(conn);
517 
518     // handle different packet types
519     switch (acl_flags & 0x03) {
520 
521         case 0x01: // continuation fragment
522 
523             // sanity check
524             if (conn->acl_recombination_pos == 0) {
525                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
526                 return;
527             }
528 
529             // append fragment payload (header already stored)
530             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
531             conn->acl_recombination_pos += acl_length;
532 
533             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u", acl_length,
534             //        conn->acl_recombination_pos, conn->acl_recombination_length);
535 
536             // forward complete L2CAP packet if complete.
537             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
538 
539                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
540                 // reset recombination buffer
541                 conn->acl_recombination_length = 0;
542                 conn->acl_recombination_pos = 0;
543             }
544             break;
545 
546         case 0x02: { // first fragment
547 
548             // sanity check
549             if (conn->acl_recombination_pos) {
550                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x", con_handle);
551                 return;
552             }
553 
554             // peek into L2CAP packet!
555             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
556 
557             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u", acl_length, l2cap_length);
558 
559             // compare fragment size to L2CAP packet size
560             if (acl_length >= l2cap_length + 4){
561 
562                 // forward fragment as L2CAP packet
563                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
564 
565             } else {
566                 // store first fragment and tweak acl length for complete package
567                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
568                 conn->acl_recombination_pos    = acl_length + 4;
569                 conn->acl_recombination_length = l2cap_length;
570                 bt_store_16(conn->acl_recombination_buffer, 2, l2cap_length +4);
571             }
572             break;
573 
574         }
575         default:
576             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
577             return;
578     }
579 
580     // execute main loop
581     hci_run();
582 }
583 
584 static void hci_shutdown_connection(hci_connection_t *conn){
585     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
586 
587     run_loop_remove_timer(&conn->timeout);
588 
589     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
590     btstack_memory_hci_connection_free( conn );
591 
592     // now it's gone
593     hci_emit_nr_connections_changed();
594 }
595 
596 static const uint16_t packet_type_sizes[] = {
597     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
598     HCI_ACL_DH1_SIZE, 0, 0, 0,
599     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
600     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
601 };
602 static const uint8_t  packet_type_feature_requirement_bit[] = {
603      0, // 3 slot packets
604      1, // 5 slot packets
605     25, // EDR 2 mpbs
606     26, // EDR 3 mbps
607     39, // 3 slot EDR packts
608     40, // 5 slot EDR packet
609 };
610 static const uint16_t packet_type_feature_packet_mask[] = {
611     0x0f00, // 3 slot packets
612     0xf000, // 5 slot packets
613     0x1102, // EDR 2 mpbs
614     0x2204, // EDR 3 mbps
615     0x0300, // 3 slot EDR packts
616     0x3000, // 5 slot EDR packet
617 };
618 
619 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
620     // enable packet types based on size
621     uint16_t packet_types = 0;
622     int i;
623     for (i=0;i<16;i++){
624         if (packet_type_sizes[i] == 0) continue;
625         if (packet_type_sizes[i] <= buffer_size){
626             packet_types |= 1 << i;
627         }
628     }
629     // disable packet types due to missing local supported features
630     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
631         int bit_idx = packet_type_feature_requirement_bit[i];
632         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
633         if (feature_set) continue;
634         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
635         packet_types &= ~packet_type_feature_packet_mask[i];
636     }
637     // flip bits for "may not be used"
638     packet_types ^= 0x3306;
639     return packet_types;
640 }
641 
642 uint16_t hci_usable_acl_packet_types(void){
643     return hci_stack->packet_types;
644 }
645 
646 uint8_t* hci_get_outgoing_packet_buffer(void){
647     // hci packet buffer is >= acl data packet length
648     return hci_stack->hci_packet_buffer;
649 }
650 
651 uint16_t hci_max_acl_data_packet_length(void){
652     return hci_stack->acl_data_packet_length;
653 }
654 
655 int hci_non_flushable_packet_boundary_flag_supported(void){
656     // No. 54, byte 6, bit 6
657     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
658 }
659 
660 int hci_ssp_supported(void){
661     // No. 51, byte 6, bit 3
662     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
663 }
664 
665 int hci_classic_supported(void){
666     // No. 37, byte 4, bit 5, = No BR/EDR Support
667     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
668 }
669 
670 int hci_le_supported(void){
671 #ifdef HAVE_BLE
672     // No. 37, byte 4, bit 6 = LE Supported (Controller)
673     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
674 #else
675     return 0;
676 #endif
677 }
678 
679 // get addr type and address used in advertisement packets
680 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
681     *addr_type = hci_stack->adv_addr_type;
682     if (hci_stack->adv_addr_type){
683         memcpy(addr, hci_stack->adv_address, 6);
684     } else {
685         memcpy(addr, hci_stack->local_bd_addr, 6);
686     }
687 }
688 
689 #ifdef HAVE_BLE
690 void le_handle_advertisement_report(uint8_t *packet, int size){
691     int offset = 3;
692     int num_reports = packet[offset];
693     offset += 1;
694 
695     int i;
696     log_info("HCI: handle adv report with num reports: %d", num_reports);
697     for (i=0; i<num_reports;i++){
698         uint8_t data_length = packet[offset + 8];
699         uint8_t event_size = 10 + data_length;
700         uint8_t event[2 + event_size ];
701         int pos = 0;
702         event[pos++] = GAP_LE_ADVERTISING_REPORT;
703         event[pos++] = event_size;
704         memcpy(&event[pos], &packet[offset], 1+1+6); // event type + address type + address
705         offset += 8;
706         pos += 8;
707         event[pos++] = packet[offset + 1 + data_length]; // rssi
708         event[pos++] = packet[offset++]; //data_length;
709         memcpy(&event[pos], &packet[offset], data_length);
710         pos += data_length;
711         offset += data_length + 1; // rssi
712         hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
713         hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
714     }
715 }
716 #endif
717 
718 static void hci_initializing_event_handler(uint8_t * packet, uint16_t size){
719     uint8_t command_completed = 0;
720     if ((hci_stack->substate % 2) == 0) return;
721     // odd: waiting for event
722     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
723         uint16_t opcode = READ_BT_16(packet,3);
724         if (opcode == hci_stack->last_cmd_opcode){
725             command_completed = 1;
726             log_info("Command complete for expected opcode %04x -> new substate %u", opcode, hci_stack->substate);
727         } else {
728             log_info("Command complete for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
729         }
730     }
731     if (packet[0] == HCI_EVENT_COMMAND_STATUS){
732         uint8_t  status = packet[2];
733         uint16_t opcode = READ_BT_16(packet,4);
734         if (opcode == hci_stack->last_cmd_opcode){
735             if (status){
736                 command_completed = 1;
737                 log_error("Command status error 0x%02x for expected opcode %04x -> new substate %u", status, opcode, hci_stack->substate);
738             } else {
739                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
740             }
741         } else {
742             log_info("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
743         }
744     }
745 
746     if (!command_completed) return;
747 
748     switch(hci_stack->substate >> 1){
749         default:
750             hci_stack->substate++;
751             break;
752     }
753 }
754 
755 static void hci_initializing_state_machine(){
756         // log_info("hci_init: substate %u", hci_stack->substate);
757     if (hci_stack->substate % 2) {
758         // odd: waiting for command completion
759         return;
760     }
761     switch (hci_stack->substate >> 1){
762         case 0: // RESET
763             hci_state_reset();
764 
765             hci_send_cmd(&hci_reset);
766             if (hci_stack->config == NULL || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
767                 // skip baud change
768                 hci_stack->substate = 4; // >> 1 = 2
769             }
770             break;
771         case 1: // SEND BAUD CHANGE
772             hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
773             hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
774             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
775             break;
776         case 2: // LOCAL BAUD CHANGE
777             log_info("Local baud rate change");
778             hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
779             hci_stack->substate += 2;
780             // break missing here for fall through
781 
782         case 3:
783             log_info("Custom init");
784             // Custom initialization
785             if (hci_stack->control && hci_stack->control->next_cmd){
786                 int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
787                 if (valid_cmd){
788                     int size = 3 + hci_stack->hci_packet_buffer[2];
789                     hci_stack->last_cmd_opcode = READ_BT_16(hci_stack->hci_packet_buffer, 0);
790                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
791                     hci_stack->substate = 4; // more init commands
792                     break;
793                 }
794                 log_info("hci_run: init script done");
795             }
796             // otherwise continue
797             hci_send_cmd(&hci_read_bd_addr);
798             break;
799         case 4:
800             hci_send_cmd(&hci_read_buffer_size);
801             break;
802         case 5:
803             hci_send_cmd(&hci_read_local_supported_features);
804             break;
805         case 6:
806             if (hci_le_supported()){
807                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
808             } else {
809                 // Kensington Bluetoot 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
810                 hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
811             }
812 
813             // skip Classic init commands for LE only chipsets
814             if (!hci_classic_supported()){
815                 if (hci_le_supported()){
816                     hci_stack->substate = 11 << 1;    // skip all classic command
817                 } else {
818                     log_error("Neither BR/EDR nor LE supported");
819                     hci_stack->substate = 14 << 1;    // skip all
820                 }
821             }
822             break;
823         case 7:
824             if (hci_ssp_supported()){
825                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
826                 break;
827             }
828             hci_stack->substate += 2;
829             // break missing here for fall through
830 
831         case 8:
832             // ca. 15 sec
833             hci_send_cmd(&hci_write_page_timeout, 0x6000);
834             break;
835         case 9:
836             hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
837             break;
838         case 10:
839             if (hci_stack->local_name){
840                 hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
841             } else {
842                 char hostname[30];
843 #ifdef EMBEDDED
844                 // BTstack-11:22:33:44:55:66
845                 strcpy(hostname, "BTstack ");
846                 strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
847                 log_info("---> Name %s", hostname);
848 #else
849                 // hostname for POSIX systems
850                 gethostname(hostname, 30);
851                 hostname[29] = '\0';
852 #endif
853                 hci_send_cmd(&hci_write_local_name, hostname);
854             }
855             break;
856         case 11:
857             hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
858             if (!hci_le_supported()){
859                 // SKIP LE init for Classic only configuration
860                 hci_stack->substate = 14 << 1;
861             }
862             break;
863 
864 #ifdef HAVE_BLE
865         // LE INIT
866         case 12:
867             hci_send_cmd(&hci_le_read_buffer_size);
868             break;
869         case 13:
870             // LE Supported Host = 1, Simultaneous Host = 0
871             hci_send_cmd(&hci_write_le_host_supported, 1, 0);
872             break;
873         case 14:
874             // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
875             hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
876             break;
877 #endif
878 
879         // DONE
880         case 15:
881             // done.
882             hci_stack->state = HCI_STATE_WORKING;
883             hci_emit_state();
884             break;
885         default:
886             break;
887     }
888     hci_stack->substate++;
889 }
890 
891 // avoid huge local variables
892 #ifndef EMBEDDED
893 static device_name_t device_name;
894 #endif
895 static void event_handler(uint8_t *packet, int size){
896 
897     uint16_t event_length = packet[1];
898 
899     // assert packet is complete
900     if (size != event_length + 2){
901         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
902         return;
903     }
904 
905     bd_addr_t addr;
906     bd_addr_type_t addr_type;
907     uint8_t link_type;
908     hci_con_handle_t handle;
909     hci_connection_t * conn;
910     int i;
911 
912     // log_info("HCI:EVENT:%02x", packet[0]);
913 
914     switch (packet[0]) {
915 
916         case HCI_EVENT_COMMAND_COMPLETE:
917             // get num cmd packets
918             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u", hci_stack->num_cmd_packets, packet[2]);
919             hci_stack->num_cmd_packets = packet[2];
920 
921             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
922                 // from offset 5
923                 // status
924                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
925                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
926                 // ignore: SCO data packet len (8)
927                 hci_stack->acl_packets_total_num  = packet[9];
928                 // ignore: total num SCO packets
929                 if (hci_stack->state == HCI_STATE_INITIALIZING){
930                     // determine usable ACL payload size
931                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
932                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
933                     }
934                     log_info("hci_read_buffer_size: used size %u, count %u",
935                              hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num);
936                 }
937             }
938 #ifdef HAVE_BLE
939             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
940                 hci_stack->le_data_packets_length = READ_BT_16(packet, 6);
941                 hci_stack->le_acl_packets_total_num  = packet[8];
942                 log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
943             }
944 #endif
945             // Dump local address
946             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
947                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
948                 log_info("Local Address, Status: 0x%02x: Addr: %s",
949                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
950             }
951             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
952                 hci_emit_discoverable_enabled(hci_stack->discoverable);
953             }
954             // Note: HCI init checks
955             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
956                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
957                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
958                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
959                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
960                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
961                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
962 
963                 // determine usable ACL packet types based buffer size and supported features
964                 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]);
965                 log_info("packet types %04x", hci_stack->packet_types);
966 
967                 // Classic/LE
968                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
969             }
970             break;
971 
972         case HCI_EVENT_COMMAND_STATUS:
973             // get num cmd packets
974             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u", hci_stack->num_cmd_packets, packet[3]);
975             hci_stack->num_cmd_packets = packet[3];
976             break;
977 
978         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
979             int offset = 3;
980             for (i=0; i<packet[2];i++){
981                 handle = READ_BT_16(packet, offset);
982                 offset += 2;
983                 uint16_t num_packets = READ_BT_16(packet, offset);
984                 offset += 2;
985 
986                 conn = hci_connection_for_handle(handle);
987                 if (!conn){
988                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
989                     continue;
990                 }
991 
992                 if (conn->num_acl_packets_sent >= num_packets){
993                     conn->num_acl_packets_sent -= num_packets;
994                 } else {
995                     log_error("hci_number_completed_packets, more slots freed then sent.");
996                     conn->num_acl_packets_sent = 0;
997                 }
998                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_acl_packets_sent);
999             }
1000             break;
1001         }
1002         case HCI_EVENT_CONNECTION_REQUEST:
1003             bt_flip_addr(addr, &packet[2]);
1004             // TODO: eval COD 8-10
1005             link_type = packet[11];
1006             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), link_type);
1007             if (link_type == 1) { // ACL
1008                 conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1009                 if (!conn) {
1010                     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1011                 }
1012                 if (!conn) {
1013                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
1014                     hci_stack->decline_reason = 0x0d;
1015                     BD_ADDR_COPY(hci_stack->decline_addr, addr);
1016                     break;
1017                 }
1018                 conn->state = RECEIVED_CONNECTION_REQUEST;
1019                 hci_run();
1020             } else {
1021                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
1022                 hci_stack->decline_reason = 0x0a;
1023                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
1024             }
1025             break;
1026 
1027         case HCI_EVENT_CONNECTION_COMPLETE:
1028             // Connection management
1029             bt_flip_addr(addr, &packet[5]);
1030             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
1031             addr_type = BD_ADDR_TYPE_CLASSIC;
1032             conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1033             if (conn) {
1034                 if (!packet[2]){
1035                     conn->state = OPEN;
1036                     conn->con_handle = READ_BT_16(packet, 3);
1037                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
1038 
1039                     // restart timer
1040                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1041                     run_loop_add_timer(&conn->timeout);
1042 
1043                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1044 
1045                     hci_emit_nr_connections_changed();
1046                 } else {
1047                     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
1048                     uint8_t status = packet[2];
1049                     bd_addr_t bd_address;
1050                     memcpy(&bd_address, conn->address, 6);
1051 
1052                     // connection failed, remove entry
1053                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1054                     btstack_memory_hci_connection_free( conn );
1055 
1056                     // notify client if dedicated bonding
1057                     if (notify_dedicated_bonding_failed){
1058                         log_info("hci notify_dedicated_bonding_failed");
1059                         hci_emit_dedicated_bonding_result(bd_address, status);
1060                     }
1061 
1062                     // if authentication error, also delete link key
1063                     if (packet[2] == 0x05) {
1064                         hci_drop_link_key_for_bd_addr(&addr);
1065                     }
1066                 }
1067             }
1068             break;
1069 
1070         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
1071             handle = READ_BT_16(packet, 3);
1072             conn = hci_connection_for_handle(handle);
1073             if (!conn) break;
1074             if (!packet[2]){
1075                 uint8_t * features = &packet[5];
1076                 if (features[6] & (1 << 3)){
1077                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
1078                 }
1079             }
1080             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
1081             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
1082             if (conn->bonding_flags & BONDING_DEDICATED){
1083                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
1084             }
1085             break;
1086 
1087         case HCI_EVENT_LINK_KEY_REQUEST:
1088             log_info("HCI_EVENT_LINK_KEY_REQUEST");
1089             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
1090             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
1091             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
1092             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
1093             hci_run();
1094             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
1095             return;
1096 
1097         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
1098             bt_flip_addr(addr, &packet[2]);
1099             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1100             if (!conn) break;
1101             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
1102             link_key_type_t link_key_type = (link_key_type_t)packet[24];
1103             // Change Connection Encryption keeps link key type
1104             if (link_key_type != CHANGED_COMBINATION_KEY){
1105                 conn->link_key_type = link_key_type;
1106             }
1107             if (!hci_stack->remote_device_db) break;
1108             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
1109             // still forward event to allow dismiss of pairing dialog
1110             break;
1111         }
1112 
1113         case HCI_EVENT_PIN_CODE_REQUEST:
1114             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
1115             // non-bondable mode: pin code negative reply will be sent
1116             if (!hci_stack->bondable){
1117                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
1118                 hci_run();
1119                 return;
1120             }
1121             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
1122             if (!hci_stack->remote_device_db) break;
1123             bt_flip_addr(addr, &packet[2]);
1124             hci_stack->remote_device_db->delete_link_key(&addr);
1125             break;
1126 
1127         case HCI_EVENT_IO_CAPABILITY_REQUEST:
1128             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
1129             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
1130             break;
1131 
1132         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
1133             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1134             if (!hci_stack->ssp_auto_accept) break;
1135             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
1136             break;
1137 
1138         case HCI_EVENT_USER_PASSKEY_REQUEST:
1139             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
1140             if (!hci_stack->ssp_auto_accept) break;
1141             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
1142             break;
1143 
1144         case HCI_EVENT_ENCRYPTION_CHANGE:
1145             handle = READ_BT_16(packet, 3);
1146             conn = hci_connection_for_handle(handle);
1147             if (!conn) break;
1148             if (packet[2] == 0) {
1149                 if (packet[5]){
1150                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
1151                 } else {
1152                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
1153                 }
1154             }
1155             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1156             break;
1157 
1158         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
1159             handle = READ_BT_16(packet, 3);
1160             conn = hci_connection_for_handle(handle);
1161             if (!conn) break;
1162 
1163             // dedicated bonding: send result and disconnect
1164             if (conn->bonding_flags & BONDING_DEDICATED){
1165                 conn->bonding_flags &= ~BONDING_DEDICATED;
1166                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
1167                 conn->bonding_status = packet[2];
1168                 break;
1169             }
1170 
1171             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
1172                 // link key sufficient for requested security
1173                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
1174                 break;
1175             }
1176             // not enough
1177             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
1178             break;
1179 
1180 #ifndef EMBEDDED
1181         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
1182             if (!hci_stack->remote_device_db) break;
1183             if (packet[2]) break; // status not ok
1184             bt_flip_addr(addr, &packet[3]);
1185             // fix for invalid remote names - terminate on 0xff
1186             for (i=0; i<248;i++){
1187                 if (packet[9+i] == 0xff){
1188                     packet[9+i] = 0;
1189                     break;
1190                 }
1191             }
1192             memset(&device_name, 0, sizeof(device_name_t));
1193             strncpy((char*) device_name, (char*) &packet[9], 248);
1194             hci_stack->remote_device_db->put_name(&addr, &device_name);
1195             break;
1196 
1197         case HCI_EVENT_INQUIRY_RESULT:
1198         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:{
1199             if (!hci_stack->remote_device_db) break;
1200             // first send inq result packet
1201             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1202             // then send cached remote names
1203             int offset = 3;
1204             for (i=0; i<packet[2];i++){
1205                 bt_flip_addr(addr, &packet[offset]);
1206                 offset += 14; // 6 + 1 + 1 + 1 + 3 + 2;
1207                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
1208                     hci_emit_remote_name_cached(&addr, &device_name);
1209                 }
1210             }
1211             return;
1212         }
1213 #endif
1214 
1215         // HCI_EVENT_DISCONNECTION_COMPLETE
1216         // has been moved down, to first notify stack before shutting connection down
1217 
1218         case HCI_EVENT_HARDWARE_ERROR:
1219             if(hci_stack->control && hci_stack->control->hw_error){
1220                 (*hci_stack->control->hw_error)();
1221             } else {
1222                 // if no special requests, just reboot stack
1223                 hci_power_control_off();
1224                 hci_power_control_on();
1225             }
1226             break;
1227 
1228         case DAEMON_EVENT_HCI_PACKET_SENT:
1229             // free packet buffer for asynchronous transport
1230             if (hci_transport_synchronous()) break;
1231             hci_stack->hci_packet_buffer_reserved = 0;
1232             break;
1233 
1234 #ifdef HAVE_BLE
1235         case HCI_EVENT_LE_META:
1236             switch (packet[2]){
1237                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
1238                     log_info("advertising report received");
1239                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
1240                     le_handle_advertisement_report(packet, size);
1241                     break;
1242                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
1243                     // Connection management
1244                     bt_flip_addr(addr, &packet[8]);
1245                     addr_type = (bd_addr_type_t)packet[7];
1246                     log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
1247                     // LE connections are auto-accepted, so just create a connection if there isn't one already
1248                     conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
1249                     if (packet[3]){
1250                         if (conn){
1251                             // outgoing connection failed, remove entry
1252                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
1253                             btstack_memory_hci_connection_free( conn );
1254                         }
1255                         // if authentication error, also delete link key
1256                         if (packet[3] == 0x05) {
1257                             hci_drop_link_key_for_bd_addr(&addr);
1258                         }
1259                         break;
1260                     }
1261                     if (!conn){
1262                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
1263                     }
1264                     if (!conn){
1265                         // no memory
1266                         break;
1267                     }
1268 
1269                     conn->state = OPEN;
1270                     conn->con_handle = READ_BT_16(packet, 4);
1271 
1272                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
1273 
1274                     // restart timer
1275                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
1276                     // run_loop_add_timer(&conn->timeout);
1277 
1278                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
1279 
1280                     hci_emit_nr_connections_changed();
1281                     break;
1282 
1283             // log_info("LE buffer size: %u, count %u", READ_BT_16(packet,6), packet[8]);
1284 
1285                 default:
1286                     break;
1287             }
1288             break;
1289 #endif
1290         default:
1291             break;
1292     }
1293 
1294     // handle BT initialization
1295     if (hci_stack->state == HCI_STATE_INITIALIZING){
1296         hci_initializing_event_handler(packet, size);
1297     }
1298 
1299     // help with BT sleep
1300     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
1301         && hci_stack->substate == 1
1302         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
1303         hci_stack->substate++;
1304     }
1305 
1306     // notify upper stack
1307     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
1308 
1309     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
1310     if (packet[0] == HCI_EVENT_DISCONNECTION_COMPLETE){
1311         if (!packet[2]){
1312             handle = READ_BT_16(packet, 3);
1313             hci_connection_t * conn = hci_connection_for_handle(handle);
1314             if (conn) {
1315                 uint8_t status = conn->bonding_status;
1316                 bd_addr_t bd_address;
1317                 memcpy(&bd_address, conn->address, 6);
1318                 hci_shutdown_connection(conn);
1319                 if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
1320                     hci_emit_dedicated_bonding_result(bd_address, status);
1321                 }
1322             }
1323         }
1324     }
1325 
1326 	// execute main loop
1327 	hci_run();
1328 }
1329 
1330 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
1331     switch (packet_type) {
1332         case HCI_EVENT_PACKET:
1333             event_handler(packet, size);
1334             break;
1335         case HCI_ACL_DATA_PACKET:
1336             acl_handler(packet, size);
1337             break;
1338         default:
1339             break;
1340     }
1341 }
1342 
1343 /** Register HCI packet handlers */
1344 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
1345     hci_stack->packet_handler = handler;
1346 }
1347 
1348 static void hci_state_reset(){
1349     // no connections yet
1350     hci_stack->connections = NULL;
1351 
1352     // keep discoverable/connectable as this has been requested by the client(s)
1353     // hci_stack->discoverable = 0;
1354     // hci_stack->connectable = 0;
1355     // hci_stack->bondable = 1;
1356 
1357     // buffer is free
1358     hci_stack->hci_packet_buffer_reserved = 0;
1359 
1360     // no pending cmds
1361     hci_stack->decline_reason = 0;
1362     hci_stack->new_scan_enable_value = 0xff;
1363 
1364     // LE
1365     hci_stack->adv_addr_type = 0;
1366     memset(hci_stack->adv_address, 0, 6);
1367     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1368     hci_stack->le_scan_type = 0xff;
1369 }
1370 
1371 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1372 
1373 #ifdef HAVE_MALLOC
1374     if (!hci_stack) {
1375         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1376     }
1377 #else
1378     hci_stack = &hci_stack_static;
1379 #endif
1380     memset(hci_stack, 0, sizeof(hci_stack_t));
1381 
1382     // reference to use transport layer implementation
1383     hci_stack->hci_transport = transport;
1384 
1385     // references to used control implementation
1386     hci_stack->control = control;
1387 
1388     // reference to used config
1389     hci_stack->config = config;
1390 
1391     // higher level handler
1392     hci_stack->packet_handler = dummy_handler;
1393 
1394     // store and open remote device db
1395     hci_stack->remote_device_db = remote_device_db;
1396     if (hci_stack->remote_device_db) {
1397         hci_stack->remote_device_db->open();
1398     }
1399 
1400     // max acl payload size defined in config.h
1401     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1402 
1403     // register packet handlers with transport
1404     transport->register_packet_handler(&packet_handler);
1405 
1406     hci_stack->state = HCI_STATE_OFF;
1407 
1408     // class of device
1409     hci_stack->class_of_device = 0x007a020c; // Smartphone
1410 
1411     // bondable by default
1412     hci_stack->bondable = 1;
1413 
1414     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1415     hci_stack->ssp_enable = 1;
1416     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1417     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1418     hci_stack->ssp_auto_accept = 1;
1419 
1420     hci_state_reset();
1421 }
1422 
1423 void hci_close(){
1424     // close remote device db
1425     if (hci_stack->remote_device_db) {
1426         hci_stack->remote_device_db->close();
1427     }
1428     while (hci_stack->connections) {
1429         // cancel all l2cap connections
1430         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1431         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1432     }
1433     hci_power_control(HCI_POWER_OFF);
1434 
1435 #ifdef HAVE_MALLOC
1436     free(hci_stack);
1437 #endif
1438     hci_stack = NULL;
1439 }
1440 
1441 void hci_set_class_of_device(uint32_t class_of_device){
1442     hci_stack->class_of_device = class_of_device;
1443 }
1444 
1445 void hci_disable_l2cap_timeout_check(){
1446     disable_l2cap_timeouts = 1;
1447 }
1448 // State-Module-Driver overview
1449 // state                    module  low-level
1450 // HCI_STATE_OFF             off      close
1451 // HCI_STATE_INITIALIZING,   on       open
1452 // HCI_STATE_WORKING,        on       open
1453 // HCI_STATE_HALTING,        on       open
1454 // HCI_STATE_SLEEPING,    off/sleep   close
1455 // HCI_STATE_FALLING_ASLEEP  on       open
1456 
1457 static int hci_power_control_on(void){
1458 
1459     // power on
1460     int err = 0;
1461     if (hci_stack->control && hci_stack->control->on){
1462         err = (*hci_stack->control->on)(hci_stack->config);
1463     }
1464     if (err){
1465         log_error( "POWER_ON failed");
1466         hci_emit_hci_open_failed();
1467         return err;
1468     }
1469 
1470     // open low-level device
1471     err = hci_stack->hci_transport->open(hci_stack->config);
1472     if (err){
1473         log_error( "HCI_INIT failed, turning Bluetooth off again");
1474         if (hci_stack->control && hci_stack->control->off){
1475             (*hci_stack->control->off)(hci_stack->config);
1476         }
1477         hci_emit_hci_open_failed();
1478         return err;
1479     }
1480     return 0;
1481 }
1482 
1483 static void hci_power_control_off(void){
1484 
1485     log_info("hci_power_control_off");
1486 
1487     // close low-level device
1488     hci_stack->hci_transport->close(hci_stack->config);
1489 
1490     log_info("hci_power_control_off - hci_transport closed");
1491 
1492     // power off
1493     if (hci_stack->control && hci_stack->control->off){
1494         (*hci_stack->control->off)(hci_stack->config);
1495     }
1496 
1497     log_info("hci_power_control_off - control closed");
1498 
1499     hci_stack->state = HCI_STATE_OFF;
1500 }
1501 
1502 static void hci_power_control_sleep(void){
1503 
1504     log_info("hci_power_control_sleep");
1505 
1506 #if 0
1507     // don't close serial port during sleep
1508 
1509     // close low-level device
1510     hci_stack->hci_transport->close(hci_stack->config);
1511 #endif
1512 
1513     // sleep mode
1514     if (hci_stack->control && hci_stack->control->sleep){
1515         (*hci_stack->control->sleep)(hci_stack->config);
1516     }
1517 
1518     hci_stack->state = HCI_STATE_SLEEPING;
1519 }
1520 
1521 static int hci_power_control_wake(void){
1522 
1523     log_info("hci_power_control_wake");
1524 
1525     // wake on
1526     if (hci_stack->control && hci_stack->control->wake){
1527         (*hci_stack->control->wake)(hci_stack->config);
1528     }
1529 
1530 #if 0
1531     // open low-level device
1532     int err = hci_stack->hci_transport->open(hci_stack->config);
1533     if (err){
1534         log_error( "HCI_INIT failed, turning Bluetooth off again");
1535         if (hci_stack->control && hci_stack->control->off){
1536             (*hci_stack->control->off)(hci_stack->config);
1537         }
1538         hci_emit_hci_open_failed();
1539         return err;
1540     }
1541 #endif
1542 
1543     return 0;
1544 }
1545 
1546 static void hci_power_transition_to_initializing(void){
1547     // set up state machine
1548     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1549     hci_stack->hci_packet_buffer_reserved = 0;
1550     hci_stack->state = HCI_STATE_INITIALIZING;
1551     hci_stack->substate = 0;
1552 }
1553 
1554 int hci_power_control(HCI_POWER_MODE power_mode){
1555 
1556     log_info("hci_power_control: %u, current mode %u", power_mode, hci_stack->state);
1557 
1558     int err = 0;
1559     switch (hci_stack->state){
1560 
1561         case HCI_STATE_OFF:
1562             switch (power_mode){
1563                 case HCI_POWER_ON:
1564                     err = hci_power_control_on();
1565                     if (err) {
1566                         log_error("hci_power_control_on() error %u", err);
1567                         return err;
1568                     }
1569                     hci_power_transition_to_initializing();
1570                     break;
1571                 case HCI_POWER_OFF:
1572                     // do nothing
1573                     break;
1574                 case HCI_POWER_SLEEP:
1575                     // do nothing (with SLEEP == OFF)
1576                     break;
1577             }
1578             break;
1579 
1580         case HCI_STATE_INITIALIZING:
1581             switch (power_mode){
1582                 case HCI_POWER_ON:
1583                     // do nothing
1584                     break;
1585                 case HCI_POWER_OFF:
1586                     // no connections yet, just turn it off
1587                     hci_power_control_off();
1588                     break;
1589                 case HCI_POWER_SLEEP:
1590                     // no connections yet, just turn it off
1591                     hci_power_control_sleep();
1592                     break;
1593             }
1594             break;
1595 
1596         case HCI_STATE_WORKING:
1597             switch (power_mode){
1598                 case HCI_POWER_ON:
1599                     // do nothing
1600                     break;
1601                 case HCI_POWER_OFF:
1602                     // see hci_run
1603                     hci_stack->state = HCI_STATE_HALTING;
1604                     break;
1605                 case HCI_POWER_SLEEP:
1606                     // see hci_run
1607                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1608                     hci_stack->substate = 0;
1609                     break;
1610             }
1611             break;
1612 
1613         case HCI_STATE_HALTING:
1614             switch (power_mode){
1615                 case HCI_POWER_ON:
1616                     hci_power_transition_to_initializing();
1617                     break;
1618                 case HCI_POWER_OFF:
1619                     // do nothing
1620                     break;
1621                 case HCI_POWER_SLEEP:
1622                     // see hci_run
1623                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1624                     hci_stack->substate = 0;
1625                     break;
1626             }
1627             break;
1628 
1629         case HCI_STATE_FALLING_ASLEEP:
1630             switch (power_mode){
1631                 case HCI_POWER_ON:
1632 
1633 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1634                     // nothing to do, if H4 supports power management
1635                     if (bt_control_iphone_power_management_enabled()){
1636                         hci_stack->state = HCI_STATE_INITIALIZING;
1637                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1638                         break;
1639                     }
1640 #endif
1641                     hci_power_transition_to_initializing();
1642                     break;
1643                 case HCI_POWER_OFF:
1644                     // see hci_run
1645                     hci_stack->state = HCI_STATE_HALTING;
1646                     break;
1647                 case HCI_POWER_SLEEP:
1648                     // do nothing
1649                     break;
1650             }
1651             break;
1652 
1653         case HCI_STATE_SLEEPING:
1654             switch (power_mode){
1655                 case HCI_POWER_ON:
1656 
1657 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1658                     // nothing to do, if H4 supports power management
1659                     if (bt_control_iphone_power_management_enabled()){
1660                         hci_stack->state = HCI_STATE_INITIALIZING;
1661                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1662                         hci_update_scan_enable();
1663                         break;
1664                     }
1665 #endif
1666                     err = hci_power_control_wake();
1667                     if (err) return err;
1668                     hci_power_transition_to_initializing();
1669                     break;
1670                 case HCI_POWER_OFF:
1671                     hci_stack->state = HCI_STATE_HALTING;
1672                     break;
1673                 case HCI_POWER_SLEEP:
1674                     // do nothing
1675                     break;
1676             }
1677             break;
1678     }
1679 
1680     // create internal event
1681 	hci_emit_state();
1682 
1683 	// trigger next/first action
1684 	hci_run();
1685 
1686     return 0;
1687 }
1688 
1689 static void hci_update_scan_enable(void){
1690     // 2 = page scan, 1 = inq scan
1691     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1692     hci_run();
1693 }
1694 
1695 void hci_discoverable_control(uint8_t enable){
1696     if (enable) enable = 1; // normalize argument
1697 
1698     if (hci_stack->discoverable == enable){
1699         hci_emit_discoverable_enabled(hci_stack->discoverable);
1700         return;
1701     }
1702 
1703     hci_stack->discoverable = enable;
1704     hci_update_scan_enable();
1705 }
1706 
1707 void hci_connectable_control(uint8_t enable){
1708     if (enable) enable = 1; // normalize argument
1709 
1710     // don't emit event
1711     if (hci_stack->connectable == enable) return;
1712 
1713     hci_stack->connectable = enable;
1714     hci_update_scan_enable();
1715 }
1716 
1717 bd_addr_t * hci_local_bd_addr(void){
1718     return &hci_stack->local_bd_addr;
1719 }
1720 
1721 void hci_run(){
1722 
1723     hci_connection_t * connection;
1724     linked_item_t * it;
1725 
1726     if (!hci_can_send_command_packet_now()) return;
1727 
1728     // global/non-connection oriented commands
1729 
1730     // decline incoming connections
1731     if (hci_stack->decline_reason){
1732         uint8_t reason = hci_stack->decline_reason;
1733         hci_stack->decline_reason = 0;
1734         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1735         return;
1736     }
1737 
1738     // send scan enable
1739     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1740         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1741         hci_stack->new_scan_enable_value = 0xff;
1742         return;
1743     }
1744 
1745 #ifdef HAVE_BLE
1746     // handle le scan
1747     if (hci_stack->state == HCI_STATE_WORKING){
1748         switch(hci_stack->le_scanning_state){
1749             case LE_START_SCAN:
1750                 hci_stack->le_scanning_state = LE_SCANNING;
1751                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1752                 return;
1753 
1754             case LE_STOP_SCAN:
1755                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1756                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1757                 return;
1758             default:
1759                 break;
1760         }
1761         if (hci_stack->le_scan_type != 0xff){
1762             // defaults: active scanning, accept all advertisement packets
1763             int scan_type = hci_stack->le_scan_type;
1764             hci_stack->le_scan_type = 0xff;
1765             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);
1766             return;
1767         }
1768     }
1769 #endif
1770 
1771     // send pending HCI commands
1772     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1773         connection = (hci_connection_t *) it;
1774 
1775         switch(connection->state){
1776             case SEND_CREATE_CONNECTION:
1777                 switch(connection->address_type){
1778                     case BD_ADDR_TYPE_CLASSIC:
1779                         log_info("sending hci_create_connection");
1780                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1781                         break;
1782                     default:
1783 #ifdef HAVE_BLE
1784                         log_info("sending hci_le_create_connection");
1785                         hci_send_cmd(&hci_le_create_connection,
1786                                      0x0060,    // scan interval: 60 ms
1787                                      0x0030,    // scan interval: 30 ms
1788                                      0,         // don't use whitelist
1789                                      connection->address_type, // peer address type
1790                                      connection->address,      // peer bd addr
1791                                      hci_stack->adv_addr_type, // our addr type:
1792                                      0x0008,    // conn interval min
1793                                      0x0018,    // conn interval max
1794                                      0,         // conn latency
1795                                      0x0048,    // supervision timeout
1796                                      0x0001,    // min ce length
1797                                      0x0001     // max ce length
1798                                      );
1799 
1800                         connection->state = SENT_CREATE_CONNECTION;
1801 #endif
1802                         break;
1803                 }
1804                 return;
1805 
1806             case RECEIVED_CONNECTION_REQUEST:
1807                 log_info("sending hci_accept_connection_request");
1808                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1809                 hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1810                 return;
1811 
1812 #ifdef HAVE_BLE
1813             case SEND_CANCEL_CONNECTION:
1814                 connection->state = SENT_CANCEL_CONNECTION;
1815                 hci_send_cmd(&hci_le_create_connection_cancel);
1816                 return;
1817 #endif
1818             case SEND_DISCONNECT:
1819                 connection->state = SENT_DISCONNECT;
1820                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
1821                 return;
1822 
1823             default:
1824                 break;
1825         }
1826 
1827         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1828             log_info("responding to link key request");
1829             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1830             link_key_t link_key;
1831             link_key_type_t link_key_type;
1832             if ( hci_stack->remote_device_db
1833               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
1834               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
1835                connection->link_key_type = link_key_type;
1836                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1837             } else {
1838                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1839             }
1840             return;
1841         }
1842 
1843         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
1844             log_info("denying to pin request");
1845             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
1846             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1847             return;
1848         }
1849 
1850         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1851             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1852             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
1853             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
1854                 // tweak authentication requirements
1855                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
1856                 if (connection->bonding_flags & BONDING_DEDICATED){
1857                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
1858                 }
1859                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
1860                     authreq |= 1;
1861                 }
1862                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
1863             } else {
1864                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1865             }
1866             return;
1867         }
1868 
1869         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1870             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1871             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1872             return;
1873         }
1874 
1875         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1876             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1877             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1878             return;
1879         }
1880 
1881         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1882             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1883             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1884             return;
1885         }
1886 
1887         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
1888             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
1889             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
1890             return;
1891         }
1892         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
1893             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
1894             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
1895             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
1896             return;
1897         }
1898         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
1899             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
1900             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
1901             return;
1902         }
1903         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
1904             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
1905             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
1906             return;
1907         }
1908 #ifdef HAVE_BLE
1909         if (connection->le_conn_interval_min){
1910             uint16_t connection_interval_min = connection->le_conn_interval_min;
1911             connection->le_conn_interval_min = 0;
1912             hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection_interval_min,
1913                 connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
1914                 0x0000, 0xffff);
1915         }
1916 #endif
1917     }
1918 
1919     // send continuation fragments
1920     if (hci_stack->acl_fragmentation_total_size > 0) {
1921         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
1922         if (hci_can_send_prepared_acl_packet_now(con_handle)){
1923             hci_connection_t *connection = hci_connection_for_handle(con_handle);
1924             if (connection) {
1925                 hci_send_acl_packet_fragments(connection);
1926                 return;
1927             }
1928             // connection gone -> discard further fragments
1929             hci_stack->acl_fragmentation_total_size = 0;
1930             hci_stack->acl_fragmentation_pos = 0;
1931         }
1932     }
1933 
1934     switch (hci_stack->state){
1935         case HCI_STATE_INITIALIZING:
1936             hci_initializing_state_machine();
1937             break;
1938 
1939         case HCI_STATE_HALTING:
1940 
1941             log_info("HCI_STATE_HALTING");
1942             // close all open connections
1943             connection =  (hci_connection_t *) hci_stack->connections;
1944             if (connection){
1945 
1946                 // send disconnect
1947                 if (!hci_can_send_command_packet_now()) return;
1948 
1949                 log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
1950                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1951 
1952                 // send disconnected event right away - causes higher layer connections to get closed, too.
1953                 hci_shutdown_connection(connection);
1954                 return;
1955             }
1956             log_info("HCI_STATE_HALTING, calling off");
1957 
1958             // switch mode
1959             hci_power_control_off();
1960 
1961             log_info("HCI_STATE_HALTING, emitting state");
1962             hci_emit_state();
1963             log_info("HCI_STATE_HALTING, done");
1964             break;
1965 
1966         case HCI_STATE_FALLING_ASLEEP:
1967             switch(hci_stack->substate) {
1968                 case 0:
1969                     log_info("HCI_STATE_FALLING_ASLEEP");
1970                     // close all open connections
1971                     connection =  (hci_connection_t *) hci_stack->connections;
1972 
1973 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1974                     // don't close connections, if H4 supports power management
1975                     if (bt_control_iphone_power_management_enabled()){
1976                         connection = NULL;
1977                     }
1978 #endif
1979                     if (connection){
1980 
1981                         // send disconnect
1982                         if (!hci_can_send_command_packet_now()) return;
1983 
1984                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
1985                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1986 
1987                         // send disconnected event right away - causes higher layer connections to get closed, too.
1988                         hci_shutdown_connection(connection);
1989                         return;
1990                     }
1991 
1992                     if (hci_classic_supported()){
1993                         // disable page and inquiry scan
1994                         if (!hci_can_send_command_packet_now()) return;
1995 
1996                         log_info("HCI_STATE_HALTING, disabling inq scans");
1997                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
1998 
1999                         // continue in next sub state
2000                         hci_stack->substate++;
2001                         break;
2002                     }
2003                     // fall through for ble-only chips
2004 
2005                 case 2:
2006                     log_info("HCI_STATE_HALTING, calling sleep");
2007 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
2008                     // don't actually go to sleep, if H4 supports power management
2009                     if (bt_control_iphone_power_management_enabled()){
2010                         // SLEEP MODE reached
2011                         hci_stack->state = HCI_STATE_SLEEPING;
2012                         hci_emit_state();
2013                         break;
2014                     }
2015 #endif
2016                     // switch mode
2017                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
2018                     hci_emit_state();
2019                     break;
2020 
2021                 default:
2022                     break;
2023             }
2024             break;
2025 
2026         default:
2027             break;
2028     }
2029 }
2030 
2031 int hci_send_cmd_packet(uint8_t *packet, int size){
2032     bd_addr_t addr;
2033     hci_connection_t * conn;
2034     // house-keeping
2035 
2036     // create_connection?
2037     if (IS_COMMAND(packet, hci_create_connection)){
2038         bt_flip_addr(addr, &packet[3]);
2039         log_info("Create_connection to %s", bd_addr_to_str(addr));
2040 
2041         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2042         if (!conn){
2043             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
2044             if (!conn){
2045                 // notify client that alloc failed
2046                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2047                 return 0; // don't sent packet to controller
2048             }
2049             conn->state = SEND_CREATE_CONNECTION;
2050         }
2051         log_info("conn state %u", conn->state);
2052         switch (conn->state){
2053             // if connection active exists
2054             case OPEN:
2055                 // and OPEN, emit connection complete command, don't send to controller
2056                 hci_emit_connection_complete(conn, 0);
2057                 return 0;
2058             case SEND_CREATE_CONNECTION:
2059                 // connection created by hci, e.g. dedicated bonding
2060                 break;
2061             default:
2062                 // otherwise, just ignore as it is already in the open process
2063                 return 0;
2064         }
2065         conn->state = SENT_CREATE_CONNECTION;
2066     }
2067 
2068     if (IS_COMMAND(packet, hci_link_key_request_reply)){
2069         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
2070     }
2071     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
2072         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
2073     }
2074 
2075     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
2076         if (hci_stack->remote_device_db){
2077             bt_flip_addr(addr, &packet[3]);
2078             hci_stack->remote_device_db->delete_link_key(&addr);
2079         }
2080     }
2081 
2082     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
2083     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
2084         bt_flip_addr(addr, &packet[3]);
2085         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2086         if (conn){
2087             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
2088         }
2089     }
2090 
2091     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
2092     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
2093     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
2094     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
2095         bt_flip_addr(addr, &packet[3]);
2096         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
2097         if (conn){
2098             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
2099         }
2100     }
2101 
2102 #ifdef HAVE_BLE
2103     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
2104         hci_stack->adv_addr_type = packet[8];
2105     }
2106     if (IS_COMMAND(packet, hci_le_set_random_address)){
2107         bt_flip_addr(hci_stack->adv_address, &packet[3]);
2108     }
2109 #endif
2110 
2111     hci_stack->num_cmd_packets--;
2112     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
2113 
2114     // free packet buffer for synchronous transport implementations
2115     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
2116         hci_stack->hci_packet_buffer_reserved = 0;
2117     }
2118 
2119     return err;
2120 }
2121 
2122 // disconnect because of security block
2123 void hci_disconnect_security_block(hci_con_handle_t con_handle){
2124     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2125     if (!connection) return;
2126     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
2127 }
2128 
2129 
2130 // Configure Secure Simple Pairing
2131 
2132 // enable will enable SSP during init
2133 void hci_ssp_set_enable(int enable){
2134     hci_stack->ssp_enable = enable;
2135 }
2136 
2137 int hci_local_ssp_activated(){
2138     return hci_ssp_supported() && hci_stack->ssp_enable;
2139 }
2140 
2141 // if set, BTstack will respond to io capability request using authentication requirement
2142 void hci_ssp_set_io_capability(int io_capability){
2143     hci_stack->ssp_io_capability = io_capability;
2144 }
2145 void hci_ssp_set_authentication_requirement(int authentication_requirement){
2146     hci_stack->ssp_authentication_requirement = authentication_requirement;
2147 }
2148 
2149 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
2150 void hci_ssp_set_auto_accept(int auto_accept){
2151     hci_stack->ssp_auto_accept = auto_accept;
2152 }
2153 
2154 /**
2155  * pre: numcmds >= 0 - it's allowed to send a command to the controller
2156  */
2157 int hci_send_cmd(const hci_cmd_t *cmd, ...){
2158 
2159     if (!hci_can_send_command_packet_now()){
2160         log_error("hci_send_cmd called but cannot send packet now");
2161         return 0;
2162     }
2163 
2164     // for HCI INITIALIZATION
2165     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
2166     hci_stack->last_cmd_opcode = cmd->opcode;
2167 
2168     hci_reserve_packet_buffer();
2169     uint8_t * packet = hci_stack->hci_packet_buffer;
2170 
2171     va_list argptr;
2172     va_start(argptr, cmd);
2173     uint16_t size = hci_create_cmd_internal(packet, cmd, argptr);
2174     va_end(argptr);
2175 
2176     return hci_send_cmd_packet(packet, size);
2177 }
2178 
2179 // Create various non-HCI events.
2180 // TODO: generalize, use table similar to hci_create_command
2181 
2182 void hci_emit_state(){
2183     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
2184     uint8_t event[3];
2185     event[0] = BTSTACK_EVENT_STATE;
2186     event[1] = sizeof(event) - 2;
2187     event[2] = hci_stack->state;
2188     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2189     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2190 }
2191 
2192 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
2193     uint8_t event[13];
2194     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
2195     event[1] = sizeof(event) - 2;
2196     event[2] = status;
2197     bt_store_16(event, 3, conn->con_handle);
2198     bt_flip_addr(&event[5], conn->address);
2199     event[11] = 1; // ACL connection
2200     event[12] = 0; // encryption disabled
2201     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2202     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2203 }
2204 
2205 void hci_emit_le_connection_complete(hci_connection_t *conn, uint8_t status){
2206     uint8_t event[21];
2207     event[0] = HCI_EVENT_LE_META;
2208     event[1] = sizeof(event) - 2;
2209     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
2210     event[3] = status;
2211     bt_store_16(event, 4, conn->con_handle);
2212     event[6] = 0; // TODO: role
2213     event[7] = conn->address_type;
2214     bt_flip_addr(&event[8], conn->address);
2215     bt_store_16(event, 14, 0); // interval
2216     bt_store_16(event, 16, 0); // latency
2217     bt_store_16(event, 18, 0); // supervision timeout
2218     event[20] = 0; // master clock accuracy
2219     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2220     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2221 }
2222 
2223 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
2224     uint8_t event[6];
2225     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
2226     event[1] = sizeof(event) - 2;
2227     event[2] = 0; // status = OK
2228     bt_store_16(event, 3, handle);
2229     event[5] = reason;
2230     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2231     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2232 }
2233 
2234 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
2235     if (disable_l2cap_timeouts) return;
2236     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
2237     uint8_t event[4];
2238     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
2239     event[1] = sizeof(event) - 2;
2240     bt_store_16(event, 2, conn->con_handle);
2241     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
2242     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2243 }
2244 
2245 void hci_emit_nr_connections_changed(){
2246     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
2247     uint8_t event[3];
2248     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
2249     event[1] = sizeof(event) - 2;
2250     event[2] = nr_hci_connections();
2251     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2252     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2253 }
2254 
2255 void hci_emit_hci_open_failed(){
2256     log_info("BTSTACK_EVENT_POWERON_FAILED");
2257     uint8_t event[2];
2258     event[0] = BTSTACK_EVENT_POWERON_FAILED;
2259     event[1] = sizeof(event) - 2;
2260     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2261     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2262 }
2263 
2264 #ifndef EMBEDDED
2265 void hci_emit_btstack_version() {
2266     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2267     uint8_t event[6];
2268     event[0] = BTSTACK_EVENT_VERSION;
2269     event[1] = sizeof(event) - 2;
2270     event[2] = BTSTACK_MAJOR;
2271     event[3] = BTSTACK_MINOR;
2272     bt_store_16(event, 4, BTSTACK_REVISION);
2273     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2274     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2275 }
2276 #endif
2277 
2278 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2279     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2280     uint8_t event[3];
2281     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2282     event[1] = sizeof(event) - 2;
2283     event[2] = enabled;
2284     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2285     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2286 }
2287 
2288 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
2289     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2290     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2291     event[1] = sizeof(event) - 2 - 1;
2292     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2293     bt_flip_addr(&event[3], *addr);
2294     memcpy(&event[9], name, 248);
2295 
2296     event[9+248] = 0;   // assert \0 for log_info
2297     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
2298 
2299     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2300     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2301 }
2302 
2303 void hci_emit_discoverable_enabled(uint8_t enabled){
2304     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2305     uint8_t event[3];
2306     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2307     event[1] = sizeof(event) - 2;
2308     event[2] = enabled;
2309     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2310     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2311 }
2312 
2313 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2314     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2315     uint8_t event[5];
2316     int pos = 0;
2317     event[pos++] = GAP_SECURITY_LEVEL;
2318     event[pos++] = sizeof(event) - 2;
2319     bt_store_16(event, 2, con_handle);
2320     pos += 2;
2321     event[pos++] = level;
2322     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2323     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2324 }
2325 
2326 void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
2327     log_info("hci_emit_dedicated_bonding_result %u ", status);
2328     uint8_t event[9];
2329     int pos = 0;
2330     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2331     event[pos++] = sizeof(event) - 2;
2332     event[pos++] = status;
2333     bt_flip_addr( * (bd_addr_t *) &event[pos], address);
2334     pos += 6;
2335     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2336     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2337 }
2338 
2339 // query if remote side supports SSP
2340 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2341     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2342     if (!connection) return 0;
2343     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2344 }
2345 
2346 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2347     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2348 }
2349 
2350 // GAP API
2351 /**
2352  * @bbrief enable/disable bonding. default is enabled
2353  * @praram enabled
2354  */
2355 void gap_set_bondable_mode(int enable){
2356     hci_stack->bondable = enable ? 1 : 0;
2357 }
2358 
2359 /**
2360  * @brief map link keys to security levels
2361  */
2362 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2363     switch (link_key_type){
2364         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2365             return LEVEL_4;
2366         case COMBINATION_KEY:
2367         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2368             return LEVEL_3;
2369         default:
2370             return LEVEL_2;
2371     }
2372 }
2373 
2374 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2375     if (!connection) return LEVEL_0;
2376     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2377     return gap_security_level_for_link_key_type(connection->link_key_type);
2378 }
2379 
2380 
2381 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2382     log_info("gap_mitm_protection_required_for_security_level %u", level);
2383     return level > LEVEL_2;
2384 }
2385 
2386 /**
2387  * @brief get current security level
2388  */
2389 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2390     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2391     if (!connection) return LEVEL_0;
2392     return gap_security_level_for_connection(connection);
2393 }
2394 
2395 /**
2396  * @brief request connection to device to
2397  * @result GAP_AUTHENTICATION_RESULT
2398  */
2399 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2400     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2401     if (!connection){
2402         hci_emit_security_level(con_handle, LEVEL_0);
2403         return;
2404     }
2405     gap_security_level_t current_level = gap_security_level(con_handle);
2406     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2407     if (current_level >= requested_level){
2408         hci_emit_security_level(con_handle, current_level);
2409         return;
2410     }
2411 
2412     connection->requested_security_level = requested_level;
2413 
2414     // would enabling ecnryption suffice (>= LEVEL_2)?
2415     if (hci_stack->remote_device_db){
2416         link_key_type_t link_key_type;
2417         link_key_t      link_key;
2418         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2419             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2420                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2421                 return;
2422             }
2423         }
2424     }
2425 
2426     // try to authenticate connection
2427     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2428     hci_run();
2429 }
2430 
2431 /**
2432  * @brief start dedicated bonding with device. disconnect after bonding
2433  * @param device
2434  * @param request MITM protection
2435  * @result GAP_DEDICATED_BONDING_COMPLETE
2436  */
2437 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2438 
2439     // create connection state machine
2440     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2441 
2442     if (!connection){
2443         return BTSTACK_MEMORY_ALLOC_FAILED;
2444     }
2445 
2446     // delete linkn key
2447     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2448 
2449     // configure LEVEL_2/3, dedicated bonding
2450     connection->state = SEND_CREATE_CONNECTION;
2451     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2452     log_info("gap_dedicated_bonding, mitm %u -> level %u", mitm_protection_required, connection->requested_security_level);
2453     connection->bonding_flags = BONDING_DEDICATED;
2454 
2455     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2456 
2457     // handle: connnection failure (connection complete != ok)
2458     // handle: authentication failure
2459     // handle: disconnect on done
2460 
2461     hci_run();
2462 
2463     return 0;
2464 }
2465 
2466 void gap_set_local_name(const char * local_name){
2467     hci_stack->local_name = local_name;
2468 }
2469 
2470 le_command_status_t le_central_start_scan(){
2471     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2472     hci_stack->le_scanning_state = LE_START_SCAN;
2473     hci_run();
2474     return BLE_PERIPHERAL_OK;
2475 }
2476 
2477 le_command_status_t le_central_stop_scan(){
2478     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2479     hci_stack->le_scanning_state = LE_STOP_SCAN;
2480     hci_run();
2481     return BLE_PERIPHERAL_OK;
2482 }
2483 
2484 void le_central_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
2485     hci_stack->le_scan_type     = scan_type;
2486     hci_stack->le_scan_interval = scan_interval;
2487     hci_stack->le_scan_window   = scan_window;
2488     hci_run();
2489 }
2490 
2491 le_command_status_t le_central_connect(bd_addr_t * addr, bd_addr_type_t addr_type){
2492     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2493     if (!conn){
2494         log_info("le_central_connect: no connection exists yet, creating context");
2495         conn = create_connection_for_bd_addr_and_type(*addr, addr_type);
2496         if (!conn){
2497             // notify client that alloc failed
2498             hci_emit_le_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2499             log_info("le_central_connect: failed to alloc context");
2500             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2501         }
2502         conn->state = SEND_CREATE_CONNECTION;
2503         log_info("le_central_connect: send create connection next");
2504         hci_run();
2505         return BLE_PERIPHERAL_OK;
2506     }
2507 
2508     if (!hci_is_le_connection(conn) ||
2509         conn->state == SEND_CREATE_CONNECTION ||
2510         conn->state == SENT_CREATE_CONNECTION) {
2511         hci_emit_le_connection_complete(conn, ERROR_CODE_COMMAND_DISALLOWED);
2512         log_error("le_central_connect: classic connection or connect is already being created");
2513         return BLE_PERIPHERAL_IN_WRONG_STATE;
2514     }
2515 
2516     log_info("le_central_connect: context exists with state %u", conn->state);
2517     hci_emit_le_connection_complete(conn, 0);
2518     hci_run();
2519     return BLE_PERIPHERAL_OK;
2520 }
2521 
2522 // @assumption: only a single outgoing LE Connection exists
2523 static hci_connection_t * le_central_get_outgoing_connection(){
2524     linked_item_t *it;
2525     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2526         hci_connection_t * conn = (hci_connection_t *) it;
2527         if (!hci_is_le_connection(conn)) continue;
2528         switch (conn->state){
2529             case SEND_CREATE_CONNECTION:
2530             case SENT_CREATE_CONNECTION:
2531                 return conn;
2532             default:
2533                 break;
2534         };
2535     }
2536     return NULL;
2537 }
2538 
2539 le_command_status_t le_central_connect_cancel(){
2540     hci_connection_t * conn = le_central_get_outgoing_connection();
2541     switch (conn->state){
2542         case SEND_CREATE_CONNECTION:
2543             // skip sending create connection and emit event instead
2544             hci_emit_le_connection_complete(conn, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2545             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2546             btstack_memory_hci_connection_free( conn );
2547             break;
2548         case SENT_CREATE_CONNECTION:
2549             // request to send cancel connection
2550             conn->state = SEND_CANCEL_CONNECTION;
2551             hci_run();
2552             break;
2553         default:
2554             break;
2555     }
2556     return BLE_PERIPHERAL_OK;
2557 }
2558 
2559 /**
2560  * @brief Updates the connection parameters for a given LE connection
2561  * @param handle
2562  * @param conn_interval_min (unit: 1.25ms)
2563  * @param conn_interval_max (unit: 1.25ms)
2564  * @param conn_latency
2565  * @param supervision_timeout (unit: 10ms)
2566  * @returns 0 if ok
2567  */
2568 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
2569     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
2570     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2571     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2572     connection->le_conn_interval_min = conn_interval_min;
2573     connection->le_conn_interval_max = conn_interval_max;
2574     connection->le_conn_latency = conn_latency;
2575     connection->le_supervision_timeout = supervision_timeout;
2576     return 0;
2577 }
2578 
2579 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2580     hci_connection_t * conn = hci_connection_for_handle(handle);
2581     if (!conn){
2582         hci_emit_disconnection_complete(handle, 0);
2583         return BLE_PERIPHERAL_OK;
2584     }
2585     conn->state = SEND_DISCONNECT;
2586     hci_run();
2587     return BLE_PERIPHERAL_OK;
2588 }
2589 
2590 void hci_disconnect_all(){
2591     linked_list_iterator_t it;
2592     linked_list_iterator_init(&it, &hci_stack->connections);
2593     while (linked_list_iterator_has_next(&it)){
2594         hci_connection_t * con = (hci_connection_t*) linked_list_iterator_next(&it);
2595         if (con->state == SENT_DISCONNECT) continue;
2596         con->state = SEND_DISCONNECT;
2597     }
2598     hci_run();
2599 }
2600