xref: /btstack/src/hci.c (revision e2602ea29f83ef9f1ad713e20d436b6cd073fd6f)
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 "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 
77 // the STACK is here
78 #ifndef HAVE_MALLOC
79 static hci_stack_t   hci_stack_static;
80 #endif
81 static hci_stack_t * hci_stack = NULL;
82 
83 // test helper
84 static uint8_t disable_l2cap_timeouts = 0;
85 
86 /**
87  * create connection for given address
88  *
89  * @return connection OR NULL, if no memory left
90  */
91 static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr, bd_addr_type_t addr_type){
92 
93     printf("create_connection_for_addr %s\n", bd_addr_to_str(addr));
94     hci_connection_t * conn = (hci_connection_t *) btstack_memory_hci_connection_get();
95     if (!conn) return NULL;
96     BD_ADDR_COPY(conn->address, addr);
97     conn->address_type = addr_type;
98     conn->con_handle = 0xffff;
99     conn->authentication_flags = AUTH_FLAGS_NONE;
100     conn->bonding_flags = 0;
101     conn->requested_security_level = LEVEL_0;
102     linked_item_set_user(&conn->timeout.item, conn);
103     conn->timeout.process = hci_connection_timeout_handler;
104     hci_connection_timestamp(conn);
105     conn->acl_recombination_length = 0;
106     conn->acl_recombination_pos = 0;
107     conn->num_acl_packets_sent = 0;
108     linked_list_add(&hci_stack->connections, (linked_item_t *) conn);
109     return conn;
110 }
111 
112 /**
113  * get connection for a given handle
114  *
115  * @return connection OR NULL, if not found
116  */
117 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
118     linked_item_t *it;
119     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
120         if ( ((hci_connection_t *) it)->con_handle == con_handle){
121             return (hci_connection_t *) it;
122         }
123     }
124     return NULL;
125 }
126 
127 /**
128  * get connection for given address
129  *
130  * @return connection OR NULL, if not found
131  */
132 hci_connection_t * hci_connection_for_bd_addr_and_type(bd_addr_t * addr, bd_addr_type_t addr_type){
133     linked_item_t *it;
134     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
135         hci_connection_t * connection = (hci_connection_t *) it;
136         if (connection->address_type != addr_type)  continue;
137         if (memcmp(addr, connection->address, 6) != 0) continue;
138         return connection;
139     }
140     return NULL;
141 }
142 
143 static void hci_connection_timeout_handler(timer_source_t *timer){
144     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
145 #ifdef HAVE_TIME
146     struct timeval tv;
147     gettimeofday(&tv, NULL);
148     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
149         // connections might be timed out
150         hci_emit_l2cap_check_timeout(connection);
151     }
152 #endif
153 #ifdef HAVE_TICK
154     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
155         // connections might be timed out
156         hci_emit_l2cap_check_timeout(connection);
157     }
158 #endif
159     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
160     run_loop_add_timer(timer);
161 }
162 
163 static void hci_connection_timestamp(hci_connection_t *connection){
164 #ifdef HAVE_TIME
165     gettimeofday(&connection->timestamp, NULL);
166 #endif
167 #ifdef HAVE_TICK
168     connection->timestamp = embedded_get_ticks();
169 #endif
170 }
171 
172 
173 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
174     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
175 }
176 
177 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
178     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
179 }
180 
181 
182 /**
183  * add authentication flags and reset timer
184  * @note: assumes classic connection
185  */
186 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
187     bd_addr_t addr;
188     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
189     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
190     if (conn) {
191         connectionSetAuthenticationFlags(conn, flags);
192         hci_connection_timestamp(conn);
193     }
194 }
195 
196 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
197     hci_connection_t * conn = hci_connection_for_handle(handle);
198     if (!conn) return 0;
199     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
200     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
201     return 0;
202 }
203 
204 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
205     if (hci_stack->remote_device_db) {
206         hci_stack->remote_device_db->delete_link_key(addr);
207     }
208 }
209 
210 int hci_is_le_connection(hci_connection_t * connection){
211     return  connection->address_type == BD_ADDR_TYPE_LE_PUBLIC ||
212     connection->address_type == BD_ADDR_TYPE_LE_RANDOM;
213 }
214 
215 
216 /**
217  * count connections
218  */
219 static int nr_hci_connections(void){
220     int count = 0;
221     linked_item_t *it;
222     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
223     return count;
224 }
225 
226 /**
227  * Dummy handler called by HCI
228  */
229 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
230 }
231 
232 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
233     hci_connection_t * connection = hci_connection_for_handle(handle);
234     if (!connection) {
235         log_error("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
236         return 0;
237     }
238     return connection->num_acl_packets_sent;
239 }
240 
241 uint8_t hci_number_free_acl_slots(){
242     uint8_t free_slots = hci_stack->total_num_acl_packets;
243     linked_item_t *it;
244     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
245         hci_connection_t * connection = (hci_connection_t *) it;
246         if (free_slots < connection->num_acl_packets_sent) {
247             log_error("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
248             return 0;
249         }
250         free_slots -= connection->num_acl_packets_sent;
251     }
252     return free_slots;
253 }
254 
255 int hci_can_send_packet_now(uint8_t packet_type){
256 
257     // check for async hci transport implementations
258     if (hci_stack->hci_transport->can_send_packet_now){
259         if (!hci_stack->hci_transport->can_send_packet_now(packet_type)){
260             return 0;
261         }
262     }
263 
264     // check regular Bluetooth flow control
265     switch (packet_type) {
266         case HCI_ACL_DATA_PACKET:
267             return hci_number_free_acl_slots();
268         case HCI_COMMAND_DATA_PACKET:
269             return hci_stack->num_cmd_packets;
270         default:
271             return 0;
272     }
273 }
274 
275 // same as hci_can_send_packet_now, but also checks if packet buffer is free for use
276 int hci_can_send_packet_now_using_packet_buffer(uint8_t packet_type){
277     if (hci_stack->hci_packet_buffer_reserved) return 0;
278     return hci_can_send_packet_now(packet_type);
279 }
280 
281 // used for internal checks in l2cap[-le].c
282 int hci_is_packet_buffer_reserved(void){
283     return hci_stack->hci_packet_buffer_reserved;
284 }
285 
286 // reserves outgoing packet buffer. @returns 1 if successful
287 int hci_reserve_packet_buffer(void){
288     if (hci_stack->hci_packet_buffer_reserved) return 0;
289     hci_stack->hci_packet_buffer_reserved = 1;
290     return 1;
291 }
292 
293 void hci_release_packet_buffer(void){
294     hci_stack->hci_packet_buffer_reserved = 0;
295 }
296 
297 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
298 int hci_transport_synchronous(void){
299     return hci_stack->hci_transport->can_send_packet_now == NULL;
300 }
301 
302 int hci_send_acl_packet(uint8_t *packet, int size){
303 
304     // check for free places on BT module
305     if (!hci_number_free_acl_slots()) return BTSTACK_ACL_BUFFERS_FULL;
306 
307     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
308     hci_connection_t *connection = hci_connection_for_handle( con_handle);
309     if (!connection) return 0;
310     hci_connection_timestamp(connection);
311 
312     // count packet
313     connection->num_acl_packets_sent++;
314     // log_info("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
315 
316     // send packet
317     int err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
318 
319     // free packet buffer for synchronous transport implementations
320     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
321         hci_stack->hci_packet_buffer_reserved = 0;
322     }
323 
324     return err;
325 }
326 
327 static void acl_handler(uint8_t *packet, int size){
328 
329     // log_info("acl_handler: size %u", size);
330 
331     // get info
332     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
333     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
334     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
335     uint16_t acl_length         = READ_ACL_LENGTH(packet);
336 
337     // ignore non-registered handle
338     if (!conn){
339         log_error( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
340         return;
341     }
342 
343     // assert packet is complete
344     if (acl_length + 4 != size){
345         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
346         return;
347     }
348 
349     // update idle timestamp
350     hci_connection_timestamp(conn);
351 
352     // handle different packet types
353     switch (acl_flags & 0x03) {
354 
355         case 0x01: // continuation fragment
356 
357             // sanity check
358             if (conn->acl_recombination_pos == 0) {
359                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
360                 return;
361             }
362 
363             // append fragment payload (header already stored)
364             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
365             conn->acl_recombination_pos += acl_length;
366 
367             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n", acl_length,
368             //        conn->acl_recombination_pos, conn->acl_recombination_length);
369 
370             // forward complete L2CAP packet if complete.
371             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
372 
373                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
374                 // reset recombination buffer
375                 conn->acl_recombination_length = 0;
376                 conn->acl_recombination_pos = 0;
377             }
378             break;
379 
380         case 0x02: { // first fragment
381 
382             // sanity check
383             if (conn->acl_recombination_pos) {
384                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
385                 return;
386             }
387 
388             // peek into L2CAP packet!
389             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
390 
391             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
392 
393             // compare fragment size to L2CAP packet size
394             if (acl_length >= l2cap_length + 4){
395 
396                 // forward fragment as L2CAP packet
397                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
398 
399             } else {
400                 // store first fragment and tweak acl length for complete package
401                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
402                 conn->acl_recombination_pos    = acl_length + 4;
403                 conn->acl_recombination_length = l2cap_length;
404                 bt_store_16(conn->acl_recombination_buffer, 2, l2cap_length +4);
405             }
406             break;
407 
408         }
409         default:
410             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
411             return;
412     }
413 
414     // execute main loop
415     hci_run();
416 }
417 
418 static void hci_shutdown_connection(hci_connection_t *conn){
419     log_info("Connection closed: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
420 
421     run_loop_remove_timer(&conn->timeout);
422 
423     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
424     btstack_memory_hci_connection_free( conn );
425 
426     // now it's gone
427     hci_emit_nr_connections_changed();
428 }
429 
430 static const uint16_t packet_type_sizes[] = {
431     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
432     HCI_ACL_DH1_SIZE, 0, 0, 0,
433     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
434     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
435 };
436 static const uint8_t  packet_type_feature_requirement_bit[] = {
437      0, // 3 slot packets
438      1, // 5 slot packets
439     25, // EDR 2 mpbs
440     26, // EDR 3 mbps
441     39, // 3 slot EDR packts
442     40, // 5 slot EDR packet
443 };
444 static const uint16_t packet_type_feature_packet_mask[] = {
445     0x0f00, // 3 slot packets
446     0xf000, // 5 slot packets
447     0x1102, // EDR 2 mpbs
448     0x2204, // EDR 3 mbps
449     0x0300, // 3 slot EDR packts
450     0x3000, // 5 slot EDR packet
451 };
452 
453 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
454     // enable packet types based on size
455     uint16_t packet_types = 0;
456     int i;
457     for (i=0;i<16;i++){
458         if (packet_type_sizes[i] == 0) continue;
459         if (packet_type_sizes[i] <= buffer_size){
460             packet_types |= 1 << i;
461         }
462     }
463     // disable packet types due to missing local supported features
464     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
465         int bit_idx = packet_type_feature_requirement_bit[i];
466         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
467         if (feature_set) continue;
468         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
469         packet_types &= ~packet_type_feature_packet_mask[i];
470     }
471     // flip bits for "may not be used"
472     packet_types ^= 0x3306;
473     return packet_types;
474 }
475 
476 uint16_t hci_usable_acl_packet_types(void){
477     return hci_stack->packet_types;
478 }
479 
480 uint8_t* hci_get_outgoing_packet_buffer(void){
481     // hci packet buffer is >= acl data packet length
482     return hci_stack->hci_packet_buffer;
483 }
484 
485 uint16_t hci_max_acl_data_packet_length(void){
486     return hci_stack->acl_data_packet_length;
487 }
488 
489 int hci_non_flushable_packet_boundary_flag_supported(void){
490     // No. 54, byte 6, bit 6
491     return (hci_stack->local_supported_features[6] & (1 << 6)) != 0;
492 }
493 
494 int hci_ssp_supported(void){
495     // No. 51, byte 6, bit 3
496     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
497 }
498 
499 int hci_classic_supported(void){
500     // No. 37, byte 4, bit 5, = No BR/EDR Support
501     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
502 }
503 
504 int hci_le_supported(void){
505 #ifdef HAVE_BLE
506     // No. 37, byte 4, bit 6 = LE Supported (Controller)
507     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
508 #else
509     return 0;
510 #endif
511 }
512 
513 // get addr type and address used in advertisement packets
514 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
515     *addr_type = hci_stack->adv_addr_type;
516     if (hci_stack->adv_addr_type){
517         memcpy(addr, hci_stack->adv_address, 6);
518     } else {
519         memcpy(addr, hci_stack->local_bd_addr, 6);
520     }
521 }
522 
523 #ifdef HAVE_BLE
524 static void le_handle_advertisement_report(uint8_t *packet, int size){
525     int num_reports = packet[3];
526     int i;
527     int total_data_length = 0;
528     int data_offset = 0;
529 
530     for (i=0; i<num_reports;i++){
531         total_data_length += packet[4+num_reports*8+i];
532     }
533 
534     for (i=0; i<num_reports;i++){
535         int pos = 0;
536         uint8_t data_length = packet[4+num_reports*8+i];
537         uint8_t event_size = 10 + data_length;
538         uint8_t event[2 + event_size ];
539         event[pos++] = GAP_LE_ADVERTISING_REPORT;
540         event[pos++] = event_size;
541         event[pos++] = packet[4+i]; // event_type;
542         event[pos++] = packet[4+num_reports+i]; // address_type;
543         memcpy(&event[pos], &packet[4+num_reports*2+i*6], 6); // bt address
544         pos += 6;
545         event[pos++] = packet[4+num_reports*9+total_data_length + i];
546         event[pos++] = data_length;
547         memcpy(&event[pos], &packet[4+num_reports*9+data_offset], data_length);
548         data_offset += data_length;
549         pos += data_length;
550         hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
551     }
552 }
553 #endif
554 
555 // avoid huge local variables
556 #ifndef EMBEDDED
557 static device_name_t device_name;
558 #endif
559 static void event_handler(uint8_t *packet, int size){
560 
561     uint16_t event_length = packet[1];
562 
563     // assert packet is complete
564     if (size != event_length + 2){
565         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
566         return;
567     }
568 
569     bd_addr_t addr;
570     bd_addr_type_t addr_type;
571     uint8_t link_type;
572     hci_con_handle_t handle;
573     hci_connection_t * conn;
574     int i;
575 
576     // printf("HCI:EVENT:%02x\n", packet[0]);
577 
578     switch (packet[0]) {
579 
580         case HCI_EVENT_COMMAND_COMPLETE:
581             // get num cmd packets
582             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u\n", hci_stack->num_cmd_packets, packet[2]);
583             hci_stack->num_cmd_packets = packet[2];
584 
585             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
586                 // from offset 5
587                 // status
588                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
589                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
590                 // ignore: SCO data packet len (8)
591                 hci_stack->total_num_acl_packets  = packet[9];
592                 // ignore: total num SCO packets
593                 if (hci_stack->state == HCI_STATE_INITIALIZING){
594                     // determine usable ACL payload size
595                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
596                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
597                     }
598                     log_info("hci_read_buffer_size: used size %u, count %u\n",
599                              hci_stack->acl_data_packet_length, hci_stack->total_num_acl_packets);
600                 }
601             }
602 #ifdef HAVE_BLE
603             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
604                 hci_stack->le_data_packet_length = READ_BT_16(packet, 6);
605                 hci_stack->total_num_le_packets  = packet[8];
606                 log_info("hci_le_read_buffer_size: size %u, count %u\n", hci_stack->le_data_packet_length, hci_stack->total_num_le_packets);
607 
608                 // use LE buffers if no clasic buffers have been reported
609                 if (hci_stack->total_num_acl_packets == 0){
610                     log_info("use le buffers instead of classic ones");
611                     hci_stack->total_num_acl_packets  = hci_stack->total_num_le_packets;
612                     hci_stack->acl_data_packet_length = hci_stack->le_data_packet_length;
613                     // determine usable ACL payload size
614                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
615                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
616                     }
617                 }
618             }
619 #endif
620             // Dump local address
621             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
622                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
623                 log_info("Local Address, Status: 0x%02x: Addr: %s\n",
624                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
625             }
626             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
627                 hci_emit_discoverable_enabled(hci_stack->discoverable);
628             }
629             // Note: HCI init checks
630             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
631                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
632                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
633                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
634                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
635                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
636                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
637 
638                 // determine usable ACL packet types based buffer size and supported features
639                 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]);
640                 log_info("packet types %04x", hci_stack->packet_types);
641 
642                 // Classic/LE
643                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
644             }
645             break;
646 
647         case HCI_EVENT_COMMAND_STATUS:
648             // get num cmd packets
649             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u\n", hci_stack->num_cmd_packets, packet[3]);
650             hci_stack->num_cmd_packets = packet[3];
651             break;
652 
653         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
654             for (i=0; i<packet[2];i++){
655                 handle = READ_BT_16(packet, 3 + 2*i);
656                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
657                 conn = hci_connection_for_handle(handle);
658                 if (!conn){
659                     log_error("hci_number_completed_packet lists unused con handle %u\n", handle);
660                     continue;
661                 }
662                 conn->num_acl_packets_sent -= num_packets;
663                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
664             }
665             break;
666 
667         case HCI_EVENT_CONNECTION_REQUEST:
668             bt_flip_addr(addr, &packet[2]);
669             // TODO: eval COD 8-10
670             link_type = packet[11];
671             log_info("Connection_incoming: %s, type %u\n", bd_addr_to_str(addr), link_type);
672             if (link_type == 1) { // ACL
673                 conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
674                 if (!conn) {
675                     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
676                 }
677                 if (!conn) {
678                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
679                     hci_stack->decline_reason = 0x0d;
680                     BD_ADDR_COPY(hci_stack->decline_addr, addr);
681                     break;
682                 }
683                 conn->state = RECEIVED_CONNECTION_REQUEST;
684                 hci_run();
685             } else {
686                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
687                 hci_stack->decline_reason = 0x0a;
688                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
689             }
690             break;
691 
692         case HCI_EVENT_CONNECTION_COMPLETE:
693             // Connection management
694             bt_flip_addr(addr, &packet[5]);
695             log_info("Connection_complete (status=%u) %s\n", packet[2], bd_addr_to_str(addr));
696             addr_type = BD_ADDR_TYPE_CLASSIC;
697             conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
698             if (conn) {
699                 if (!packet[2]){
700                     conn->state = OPEN;
701                     conn->con_handle = READ_BT_16(packet, 3);
702                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
703 
704                     // restart timer
705                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
706                     run_loop_add_timer(&conn->timeout);
707 
708                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
709 
710                     hci_emit_nr_connections_changed();
711                 } else {
712                     // notify client if dedicated bonding
713                     if (conn->bonding_flags & BONDING_DEDICATED){
714                         hci_emit_dedicated_bonding_result(conn, packet[2]);
715                     }
716 
717                     // connection failed, remove entry
718                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
719                     btstack_memory_hci_connection_free( conn );
720 
721                     // if authentication error, also delete link key
722                     if (packet[2] == 0x05) {
723                         hci_drop_link_key_for_bd_addr(&addr);
724                     }
725                 }
726             }
727             break;
728 
729         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
730             handle = READ_BT_16(packet, 3);
731             conn = hci_connection_for_handle(handle);
732             if (!conn) break;
733             if (!packet[2]){
734                 uint8_t * features = &packet[5];
735                 if (features[6] & (1 << 3)){
736                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
737                 }
738             }
739             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
740             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
741             if (conn->bonding_flags & BONDING_DEDICATED){
742                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
743             }
744             break;
745 
746         case HCI_EVENT_LINK_KEY_REQUEST:
747             log_info("HCI_EVENT_LINK_KEY_REQUEST\n");
748             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
749             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
750             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
751             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
752             hci_run();
753             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
754             return;
755 
756         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
757             bt_flip_addr(addr, &packet[2]);
758             conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
759             if (!conn) break;
760             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
761             link_key_type_t link_key_type = (link_key_type_t)packet[24];
762             // Change Connection Encryption keeps link key type
763             if (link_key_type != CHANGED_COMBINATION_KEY){
764                 conn->link_key_type = link_key_type;
765             }
766             if (!hci_stack->remote_device_db) break;
767             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
768             // still forward event to allow dismiss of pairing dialog
769             break;
770         }
771 
772         case HCI_EVENT_PIN_CODE_REQUEST:
773             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
774             // non-bondable mode: pin code negative reply will be sent
775             if (!hci_stack->bondable){
776                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
777                 hci_run();
778                 return;
779             }
780             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
781             if (!hci_stack->remote_device_db) break;
782             bt_flip_addr(addr, &packet[2]);
783             hci_stack->remote_device_db->delete_link_key(&addr);
784             break;
785 
786         case HCI_EVENT_IO_CAPABILITY_REQUEST:
787             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
788             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
789             break;
790 
791         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
792             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
793             if (!hci_stack->ssp_auto_accept) break;
794             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
795             break;
796 
797         case HCI_EVENT_USER_PASSKEY_REQUEST:
798             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
799             if (!hci_stack->ssp_auto_accept) break;
800             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
801             break;
802 
803         case HCI_EVENT_ENCRYPTION_CHANGE:
804             handle = READ_BT_16(packet, 3);
805             conn = hci_connection_for_handle(handle);
806             if (!conn) break;
807             if (packet[2] == 0) {
808                 if (packet[5]){
809                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
810                 } else {
811                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
812                 }
813             }
814             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
815             break;
816 
817         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
818             handle = READ_BT_16(packet, 3);
819             conn = hci_connection_for_handle(handle);
820             if (!conn) break;
821 
822             // dedicated bonding: send result and disconnect
823             if (conn->bonding_flags & BONDING_DEDICATED){
824                 conn->bonding_flags &= ~BONDING_DEDICATED;
825                 hci_emit_dedicated_bonding_result( conn, packet[2]);
826                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
827                 break;
828             }
829 
830             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
831                 // link key sufficient for requested security
832                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
833                 break;
834             }
835             // not enough
836             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
837             break;
838 
839 #ifndef EMBEDDED
840         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
841             if (!hci_stack->remote_device_db) break;
842             if (packet[2]) break; // status not ok
843             bt_flip_addr(addr, &packet[3]);
844             // fix for invalid remote names - terminate on 0xff
845             for (i=0; i<248;i++){
846                 if (packet[9+i] == 0xff){
847                     packet[9+i] = 0;
848                     break;
849                 }
850             }
851             memset(&device_name, 0, sizeof(device_name_t));
852             strncpy((char*) device_name, (char*) &packet[9], 248);
853             hci_stack->remote_device_db->put_name(&addr, &device_name);
854             break;
855 
856         case HCI_EVENT_INQUIRY_RESULT:
857         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
858             if (!hci_stack->remote_device_db) break;
859             // first send inq result packet
860             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
861             // then send cached remote names
862             for (i=0; i<packet[2];i++){
863                 bt_flip_addr(addr, &packet[3+i*6]);
864                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
865                     hci_emit_remote_name_cached(&addr, &device_name);
866                 }
867             }
868             return;
869 #endif
870 
871         case HCI_EVENT_DISCONNECTION_COMPLETE:
872             if (!packet[2]){
873                 handle = READ_BT_16(packet, 3);
874                 hci_connection_t * conn = hci_connection_for_handle(handle);
875                 if (conn) {
876                     hci_shutdown_connection(conn);
877                 }
878             }
879             break;
880 
881         case HCI_EVENT_HARDWARE_ERROR:
882             if(hci_stack->control && hci_stack->control->hw_error){
883                 (*hci_stack->control->hw_error)();
884             }
885             break;
886 
887         case DAEMON_EVENT_HCI_PACKET_SENT:
888             // free packet buffer for asynchronous transport
889             if (hci_transport_synchronous()) break;
890             hci_stack->hci_packet_buffer_reserved = 0;
891             break;
892 
893 #ifdef HAVE_BLE
894         case HCI_EVENT_LE_META:
895             switch (packet[2]){
896                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
897                     if (hci_stack->le_scanning_state != LE_SCANNING) break;
898                     le_handle_advertisement_report(packet, size);
899                     break;
900                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
901                     // Connection management
902                     bt_flip_addr(addr, &packet[8]);
903                     addr_type = (bd_addr_type_t)packet[7];
904                     log_info("LE Connection_complete (status=%u) type %u, %s\n", packet[3], addr_type, bd_addr_to_str(addr));
905                     // LE connections are auto-accepted, so just create a connection if there isn't one already
906                     conn = hci_connection_for_bd_addr_and_type(&addr, addr_type);
907                     if (packet[3]){
908                         if (conn){
909                             // outgoing connection failed, remove entry
910                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
911                             btstack_memory_hci_connection_free( conn );
912                         }
913                         // if authentication error, also delete link key
914                         if (packet[3] == 0x05) {
915                             hci_drop_link_key_for_bd_addr(&addr);
916                         }
917                         break;
918                     }
919                     if (!conn){
920                         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
921                     }
922                     if (!conn){
923                         // no memory
924                         break;
925                     }
926 
927                     conn->state = OPEN;
928                     conn->con_handle = READ_BT_16(packet, 4);
929 
930                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
931 
932                     // restart timer
933                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
934                     // run_loop_add_timer(&conn->timeout);
935 
936                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
937 
938                     hci_emit_nr_connections_changed();
939                     break;
940 
941             // printf("LE buffer size: %u, count %u\n", READ_BT_16(packet,6), packet[8]);
942 
943                 default:
944                     break;
945             }
946             break;
947 #endif
948 
949         default:
950             break;
951     }
952 
953     // handle BT initialization
954     if (hci_stack->state == HCI_STATE_INITIALIZING){
955         if (hci_stack->substate % 2){
956             // odd: waiting for event
957             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
958                 // wait for explicit COMMAND COMPLETE on RESET
959                 if (hci_stack->substate > 1 || COMMAND_COMPLETE_EVENT(packet, hci_reset)) {
960                     hci_stack->substate++;
961                 }
962             }
963         }
964     }
965 
966     // help with BT sleep
967     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
968         && hci_stack->substate == 1
969         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
970         hci_stack->substate++;
971     }
972 
973     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
974 
975 	// execute main loop
976 	hci_run();
977 }
978 
979 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
980     switch (packet_type) {
981         case HCI_EVENT_PACKET:
982             event_handler(packet, size);
983             break;
984         case HCI_ACL_DATA_PACKET:
985             acl_handler(packet, size);
986             break;
987         default:
988             break;
989     }
990 }
991 
992 /** Register HCI packet handlers */
993 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
994     hci_stack->packet_handler = handler;
995 }
996 
997 void hci_state_reset(){
998     // no connections yet
999     hci_stack->connections = NULL;
1000     hci_stack->discoverable = 0;
1001     hci_stack->connectable = 0;
1002     hci_stack->bondable = 1;
1003 
1004     // no pending cmds
1005     hci_stack->decline_reason = 0;
1006     hci_stack->new_scan_enable_value = 0xff;
1007 
1008     // LE
1009     hci_stack->adv_addr_type = 0;
1010     memset(hci_stack->adv_address, 0, 6);
1011     hci_stack->le_scanning_state = LE_SCAN_IDLE;
1012     hci_stack->le_scan_type = 0xff;
1013 }
1014 
1015 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
1016 
1017 #ifdef HAVE_MALLOC
1018     if (!hci_stack) {
1019         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
1020     }
1021 #else
1022     hci_stack = &hci_stack_static;
1023 #endif
1024     memset(hci_stack, 0, sizeof(hci_stack_t));
1025 
1026     // reference to use transport layer implementation
1027     hci_stack->hci_transport = transport;
1028 
1029     // references to used control implementation
1030     hci_stack->control = control;
1031 
1032     // reference to used config
1033     hci_stack->config = config;
1034 
1035     // higher level handler
1036     hci_stack->packet_handler = dummy_handler;
1037 
1038     // store and open remote device db
1039     hci_stack->remote_device_db = remote_device_db;
1040     if (hci_stack->remote_device_db) {
1041         hci_stack->remote_device_db->open();
1042     }
1043 
1044     // max acl payload size defined in config.h
1045     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
1046 
1047     // register packet handlers with transport
1048     transport->register_packet_handler(&packet_handler);
1049 
1050     hci_stack->state = HCI_STATE_OFF;
1051 
1052     // class of device
1053     hci_stack->class_of_device = 0x007a020c; // Smartphone
1054 
1055     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
1056     hci_stack->ssp_enable = 1;
1057     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1058     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1059     hci_stack->ssp_auto_accept = 1;
1060 
1061     hci_state_reset();
1062 }
1063 
1064 void hci_close(){
1065     // close remote device db
1066     if (hci_stack->remote_device_db) {
1067         hci_stack->remote_device_db->close();
1068     }
1069     while (hci_stack->connections) {
1070         // cancel all l2cap connections
1071         hci_emit_disconnection_complete(((hci_connection_t *) hci_stack->connections)->con_handle, 0x16); // terminated by local host
1072         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1073     }
1074     hci_power_control(HCI_POWER_OFF);
1075 
1076 #ifdef HAVE_MALLOC
1077     free(hci_stack);
1078 #endif
1079     hci_stack = NULL;
1080 }
1081 
1082 void hci_set_class_of_device(uint32_t class_of_device){
1083     hci_stack->class_of_device = class_of_device;
1084 }
1085 
1086 void hci_disable_l2cap_timeout_check(){
1087     disable_l2cap_timeouts = 1;
1088 }
1089 // State-Module-Driver overview
1090 // state                    module  low-level
1091 // HCI_STATE_OFF             off      close
1092 // HCI_STATE_INITIALIZING,   on       open
1093 // HCI_STATE_WORKING,        on       open
1094 // HCI_STATE_HALTING,        on       open
1095 // HCI_STATE_SLEEPING,    off/sleep   close
1096 // HCI_STATE_FALLING_ASLEEP  on       open
1097 
1098 static int hci_power_control_on(void){
1099 
1100     // power on
1101     int err = 0;
1102     if (hci_stack->control && hci_stack->control->on){
1103         err = (*hci_stack->control->on)(hci_stack->config);
1104     }
1105     if (err){
1106         log_error( "POWER_ON failed\n");
1107         hci_emit_hci_open_failed();
1108         return err;
1109     }
1110 
1111     // open low-level device
1112     err = hci_stack->hci_transport->open(hci_stack->config);
1113     if (err){
1114         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
1115         if (hci_stack->control && hci_stack->control->off){
1116             (*hci_stack->control->off)(hci_stack->config);
1117         }
1118         hci_emit_hci_open_failed();
1119         return err;
1120     }
1121     return 0;
1122 }
1123 
1124 static void hci_power_control_off(void){
1125 
1126     log_info("hci_power_control_off\n");
1127 
1128     // close low-level device
1129     hci_stack->hci_transport->close(hci_stack->config);
1130 
1131     log_info("hci_power_control_off - hci_transport closed\n");
1132 
1133     // power off
1134     if (hci_stack->control && hci_stack->control->off){
1135         (*hci_stack->control->off)(hci_stack->config);
1136     }
1137 
1138     log_info("hci_power_control_off - control closed\n");
1139 
1140     hci_stack->state = HCI_STATE_OFF;
1141 }
1142 
1143 static void hci_power_control_sleep(void){
1144 
1145     log_info("hci_power_control_sleep\n");
1146 
1147 #if 0
1148     // don't close serial port during sleep
1149 
1150     // close low-level device
1151     hci_stack->hci_transport->close(hci_stack->config);
1152 #endif
1153 
1154     // sleep mode
1155     if (hci_stack->control && hci_stack->control->sleep){
1156         (*hci_stack->control->sleep)(hci_stack->config);
1157     }
1158 
1159     hci_stack->state = HCI_STATE_SLEEPING;
1160 }
1161 
1162 static int hci_power_control_wake(void){
1163 
1164     log_info("hci_power_control_wake\n");
1165 
1166     // wake on
1167     if (hci_stack->control && hci_stack->control->wake){
1168         (*hci_stack->control->wake)(hci_stack->config);
1169     }
1170 
1171 #if 0
1172     // open low-level device
1173     int err = hci_stack->hci_transport->open(hci_stack->config);
1174     if (err){
1175         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
1176         if (hci_stack->control && hci_stack->control->off){
1177             (*hci_stack->control->off)(hci_stack->config);
1178         }
1179         hci_emit_hci_open_failed();
1180         return err;
1181     }
1182 #endif
1183 
1184     return 0;
1185 }
1186 
1187 
1188 int hci_power_control(HCI_POWER_MODE power_mode){
1189 
1190     log_info("hci_power_control: %u, current mode %u\n", power_mode, hci_stack->state);
1191 
1192     int err = 0;
1193     switch (hci_stack->state){
1194 
1195         case HCI_STATE_OFF:
1196             switch (power_mode){
1197                 case HCI_POWER_ON:
1198                     err = hci_power_control_on();
1199                     if (err) return err;
1200                     // set up state machine
1201                     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1202                     hci_stack->state = HCI_STATE_INITIALIZING;
1203                     hci_stack->substate = 0;
1204                     break;
1205                 case HCI_POWER_OFF:
1206                     // do nothing
1207                     break;
1208                 case HCI_POWER_SLEEP:
1209                     // do nothing (with SLEEP == OFF)
1210                     break;
1211             }
1212             break;
1213 
1214         case HCI_STATE_INITIALIZING:
1215             switch (power_mode){
1216                 case HCI_POWER_ON:
1217                     // do nothing
1218                     break;
1219                 case HCI_POWER_OFF:
1220                     // no connections yet, just turn it off
1221                     hci_power_control_off();
1222                     break;
1223                 case HCI_POWER_SLEEP:
1224                     // no connections yet, just turn it off
1225                     hci_power_control_sleep();
1226                     break;
1227             }
1228             break;
1229 
1230         case HCI_STATE_WORKING:
1231             switch (power_mode){
1232                 case HCI_POWER_ON:
1233                     // do nothing
1234                     break;
1235                 case HCI_POWER_OFF:
1236                     // see hci_run
1237                     hci_stack->state = HCI_STATE_HALTING;
1238                     break;
1239                 case HCI_POWER_SLEEP:
1240                     // see hci_run
1241                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1242                     hci_stack->substate = 0;
1243                     break;
1244             }
1245             break;
1246 
1247         case HCI_STATE_HALTING:
1248             switch (power_mode){
1249                 case HCI_POWER_ON:
1250                     // set up state machine
1251                     hci_stack->state = HCI_STATE_INITIALIZING;
1252                     hci_stack->substate = 0;
1253                     break;
1254                 case HCI_POWER_OFF:
1255                     // do nothing
1256                     break;
1257                 case HCI_POWER_SLEEP:
1258                     // see hci_run
1259                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1260                     hci_stack->substate = 0;
1261                     break;
1262             }
1263             break;
1264 
1265         case HCI_STATE_FALLING_ASLEEP:
1266             switch (power_mode){
1267                 case HCI_POWER_ON:
1268 
1269 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1270                     // nothing to do, if H4 supports power management
1271                     if (bt_control_iphone_power_management_enabled()){
1272                         hci_stack->state = HCI_STATE_INITIALIZING;
1273                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1274                         break;
1275                     }
1276 #endif
1277                     // set up state machine
1278                     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1279                     hci_stack->state = HCI_STATE_INITIALIZING;
1280                     hci_stack->substate = 0;
1281                     break;
1282                 case HCI_POWER_OFF:
1283                     // see hci_run
1284                     hci_stack->state = HCI_STATE_HALTING;
1285                     break;
1286                 case HCI_POWER_SLEEP:
1287                     // do nothing
1288                     break;
1289             }
1290             break;
1291 
1292         case HCI_STATE_SLEEPING:
1293             switch (power_mode){
1294                 case HCI_POWER_ON:
1295 
1296 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1297                     // nothing to do, if H4 supports power management
1298                     if (bt_control_iphone_power_management_enabled()){
1299                         hci_stack->state = HCI_STATE_INITIALIZING;
1300                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1301                         hci_update_scan_enable();
1302                         break;
1303                     }
1304 #endif
1305                     err = hci_power_control_wake();
1306                     if (err) return err;
1307                     // set up state machine
1308                     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1309                     hci_stack->state = HCI_STATE_INITIALIZING;
1310                     hci_stack->substate = 0;
1311                     break;
1312                 case HCI_POWER_OFF:
1313                     hci_stack->state = HCI_STATE_HALTING;
1314                     break;
1315                 case HCI_POWER_SLEEP:
1316                     // do nothing
1317                     break;
1318             }
1319             break;
1320     }
1321 
1322     // create internal event
1323 	hci_emit_state();
1324 
1325 	// trigger next/first action
1326 	hci_run();
1327 
1328     return 0;
1329 }
1330 
1331 static void hci_update_scan_enable(void){
1332     // 2 = page scan, 1 = inq scan
1333     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1334     hci_run();
1335 }
1336 
1337 void hci_discoverable_control(uint8_t enable){
1338     if (enable) enable = 1; // normalize argument
1339 
1340     if (hci_stack->discoverable == enable){
1341         hci_emit_discoverable_enabled(hci_stack->discoverable);
1342         return;
1343     }
1344 
1345     hci_stack->discoverable = enable;
1346     hci_update_scan_enable();
1347 }
1348 
1349 void hci_connectable_control(uint8_t enable){
1350     if (enable) enable = 1; // normalize argument
1351 
1352     // don't emit event
1353     if (hci_stack->connectable == enable) return;
1354 
1355     hci_stack->connectable = enable;
1356     hci_update_scan_enable();
1357 }
1358 
1359 bd_addr_t * hci_local_bd_addr(void){
1360     return &hci_stack->local_bd_addr;
1361 }
1362 
1363 void hci_run(){
1364 
1365     hci_connection_t * connection;
1366     linked_item_t * it;
1367 
1368     if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) return;
1369 
1370     // global/non-connection oriented commands
1371 
1372     // decline incoming connections
1373     if (hci_stack->decline_reason){
1374         uint8_t reason = hci_stack->decline_reason;
1375         hci_stack->decline_reason = 0;
1376         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1377         return;
1378     }
1379 
1380     // send scan enable
1381     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1382         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1383         hci_stack->new_scan_enable_value = 0xff;
1384         return;
1385     }
1386 
1387 #ifdef HAVE_BLE
1388     // handle le scan
1389     if (hci_stack->state == HCI_STATE_WORKING){
1390         switch(hci_stack->le_scanning_state){
1391             case LE_START_SCAN:
1392                 hci_stack->le_scanning_state = LE_SCANNING;
1393                 hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
1394                 return;
1395 
1396             case LE_STOP_SCAN:
1397                 hci_stack->le_scanning_state = LE_SCAN_IDLE;
1398                 hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
1399                 return;
1400             default:
1401                 break;
1402         }
1403         if (hci_stack->le_scan_type != 0xff){
1404             // defaults: active scanning, accept all advertisement packets
1405             int scan_type = hci_stack->le_scan_type;
1406             hci_stack->le_scan_type = 0xff;
1407             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);
1408             return;
1409         }
1410     }
1411 #endif
1412 
1413     // send pending HCI commands
1414     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1415         connection = (hci_connection_t *) it;
1416 
1417         switch(connection->state){
1418             case SEND_CREATE_CONNECTION:
1419                 switch(connection->address_type){
1420                     case BD_ADDR_TYPE_CLASSIC:
1421                         log_info("sending hci_create_connection\n");
1422                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1423                         break;
1424                     default:
1425 #ifdef HAVE_BLE
1426                         log_info("sending hci_le_create_connection\n");
1427                         hci_send_cmd(&hci_le_create_connection,
1428                                      1000,      // scan interval: 625 ms
1429                                      1000,      // scan interval: 625 ms
1430                                      0,         // don't use whitelist
1431                                      connection->address_type, // peer address type
1432                                      connection->address,       // peer bd addr
1433                                      0,         // our addr type: public
1434                                      80,        // conn interval min
1435                                      80,        // conn interval max (3200 * 0.625)
1436                                      0,         // conn latency
1437                                      2000,      // supervision timeout
1438                                      0,         // min ce length
1439                                      1000       // max ce length
1440                                      );
1441 
1442                         connection->state = SENT_CREATE_CONNECTION;
1443 #endif
1444                         break;
1445                 }
1446                 return;
1447 
1448             case RECEIVED_CONNECTION_REQUEST:
1449                 log_info("sending hci_accept_connection_request\n");
1450                 connection->state = ACCEPTED_CONNECTION_REQUEST;
1451                 hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1452                 return;
1453 
1454 #ifdef HAVE_BLE
1455             case SEND_CANCEL_CONNECTION:
1456                 connection->state = SENT_CANCEL_CONNECTION;
1457                 hci_send_cmd(&hci_le_create_connection_cancel);
1458                 return;
1459 #endif
1460             case SEND_DISCONNECT:
1461                 connection->state = SENT_DISCONNECT;
1462                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13); // remote closed connection
1463                 return;
1464 
1465             default:
1466                 break;
1467         }
1468 
1469 
1470 
1471         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1472             log_info("responding to link key request\n");
1473             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1474             link_key_t link_key;
1475             link_key_type_t link_key_type;
1476             if ( hci_stack->remote_device_db
1477               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
1478               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
1479                connection->link_key_type = link_key_type;
1480                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1481             } else {
1482                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1483             }
1484             return;
1485         }
1486 
1487         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
1488             log_info("denying to pin request\n");
1489             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
1490             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1491             return;
1492         }
1493 
1494         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1495             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1496             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
1497             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
1498                 // tweak authentication requirements
1499                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
1500                 if (connection->bonding_flags & BONDING_DEDICATED){
1501                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
1502                 }
1503                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
1504                     authreq |= 1;
1505                 }
1506                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
1507             } else {
1508                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1509             }
1510             return;
1511         }
1512 
1513         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1514             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1515             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1516             return;
1517         }
1518 
1519         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1520             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1521             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1522             return;
1523         }
1524 
1525         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1526             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1527             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1528             return;
1529         }
1530 
1531         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
1532             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
1533             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
1534             return;
1535         }
1536         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
1537             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
1538             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
1539             return;
1540         }
1541         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
1542             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
1543             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
1544             return;
1545         }
1546         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
1547             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
1548             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
1549             return;
1550         }
1551     }
1552 
1553     switch (hci_stack->state){
1554         case HCI_STATE_INITIALIZING:
1555             // log_info("hci_init: substate %u\n", hci_stack->substate);
1556             if (hci_stack->substate % 2) {
1557                 // odd: waiting for command completion
1558                 return;
1559             }
1560             switch (hci_stack->substate >> 1){
1561                 case 0: // RESET
1562                     hci_state_reset();
1563 
1564                     hci_send_cmd(&hci_reset);
1565                     if (hci_stack->config == 0 || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
1566                         // skip baud change
1567                         hci_stack->substate = 4; // >> 1 = 2
1568                     }
1569                     break;
1570                 case 1: // SEND BAUD CHANGE
1571                     hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
1572                     hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1573                     break;
1574                 case 2: // LOCAL BAUD CHANGE
1575                     hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
1576                     hci_stack->substate += 2;
1577                     // break missing here for fall through
1578 
1579                 case 3:
1580                     // Custom initialization
1581                     if (hci_stack->control && hci_stack->control->next_cmd){
1582                         int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
1583                         if (valid_cmd){
1584                             int size = 3 + hci_stack->hci_packet_buffer[2];
1585                             hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1586                             hci_stack->substate = 4; // more init commands
1587                             break;
1588                         }
1589                         log_info("hci_run: init script done\n\r");
1590                     }
1591                     // otherwise continue
1592 					hci_send_cmd(&hci_read_bd_addr);
1593 					break;
1594 				case 4:
1595 					hci_send_cmd(&hci_read_buffer_size);
1596 					break;
1597                 case 5:
1598                     hci_send_cmd(&hci_read_local_supported_features);
1599                     break;
1600                 case 6:
1601                     if (hci_le_supported()){
1602                         hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1603                     } else {
1604                         // Kensington Bluetoot 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1605                         hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1606                     }
1607 
1608                     // skip Classic init commands for LE only chipsets
1609                     if (!hci_classic_supported()){
1610                         if (hci_le_supported()){
1611                             hci_stack->substate = 11 << 1;    // skip all classic command
1612                         } else {
1613                             log_error("Neither BR/EDR nor LE supported");
1614                             hci_stack->substate = 14 << 1;    // skip all
1615                         }
1616                     }
1617                     break;
1618                 case 7:
1619                     if (hci_ssp_supported()){
1620                         hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1621                         break;
1622                     }
1623                     hci_stack->substate += 2;
1624                     // break missing here for fall through
1625 
1626                 case 8:
1627                     // ca. 15 sec
1628                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
1629                     break;
1630                 case 9:
1631                     hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1632                     break;
1633                 case 10:
1634                     if (hci_stack->local_name){
1635                         hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
1636                     } else {
1637                         char hostname[30];
1638 #ifdef EMBEDDED
1639                         // BTstack-11:22:33:44:55:66
1640                         strcpy(hostname, "BTstack ");
1641                         strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
1642                         printf("---> Name %s\n", hostname);
1643 #else
1644                         // hostname for POSIX systems
1645                         gethostname(hostname, 30);
1646                         hostname[29] = '\0';
1647 #endif
1648                         hci_send_cmd(&hci_write_local_name, hostname);
1649                     }
1650                     break;
1651                 case 11:
1652 					hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1653                     if (!hci_le_supported()){
1654                         // SKIP LE init for Classic only configuration
1655                         hci_stack->substate = 14 << 1;
1656                     }
1657 					break;
1658 
1659 #ifdef HAVE_BLE
1660                 // LE INIT
1661                 case 12:
1662                     hci_send_cmd(&hci_le_read_buffer_size);
1663                     break;
1664                 case 13:
1665                     // LE Supported Host = 1, Simultaneous Host = 0
1666                     hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1667                     break;
1668                 case 14:
1669                     // LE Scan Parameters: active scanning, 300 ms interval, 30 ms window, public address, accept all advs
1670                     hci_send_cmd(&hci_le_set_scan_parameters, 1, 0x1e0, 0x30, 0, 0);
1671                     break;
1672 #endif
1673 
1674                 // DONE
1675                 case 15:
1676                     // done.
1677                     hci_stack->state = HCI_STATE_WORKING;
1678                     hci_emit_state();
1679                     break;
1680                 default:
1681                     break;
1682             }
1683             hci_stack->substate++;
1684             break;
1685 
1686         case HCI_STATE_HALTING:
1687 
1688             log_info("HCI_STATE_HALTING\n");
1689             // close all open connections
1690             connection =  (hci_connection_t *) hci_stack->connections;
1691             if (connection){
1692 
1693                 // send disconnect
1694                 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) return;
1695 
1696                 log_info("HCI_STATE_HALTING, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1697                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1698 
1699                 // send disconnected event right away - causes higher layer connections to get closed, too.
1700                 hci_shutdown_connection(connection);
1701                 return;
1702             }
1703             log_info("HCI_STATE_HALTING, calling off\n");
1704 
1705             // switch mode
1706             hci_power_control_off();
1707 
1708             log_info("HCI_STATE_HALTING, emitting state\n");
1709             hci_emit_state();
1710             log_info("HCI_STATE_HALTING, done\n");
1711             break;
1712 
1713         case HCI_STATE_FALLING_ASLEEP:
1714             switch(hci_stack->substate) {
1715                 case 0:
1716                     log_info("HCI_STATE_FALLING_ASLEEP\n");
1717                     // close all open connections
1718                     connection =  (hci_connection_t *) hci_stack->connections;
1719 
1720 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1721                     // don't close connections, if H4 supports power management
1722                     if (bt_control_iphone_power_management_enabled()){
1723                         connection = NULL;
1724                     }
1725 #endif
1726                     if (connection){
1727 
1728                         // send disconnect
1729                         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1730 
1731                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1732                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1733 
1734                         // send disconnected event right away - causes higher layer connections to get closed, too.
1735                         hci_shutdown_connection(connection);
1736                         return;
1737                     }
1738 
1739                     if (hci_classic_supported()){
1740                         // disable page and inquiry scan
1741                         if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) return;
1742 
1743                         log_info("HCI_STATE_HALTING, disabling inq scans\n");
1744                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
1745 
1746                         // continue in next sub state
1747                         hci_stack->substate++;
1748                         break;
1749                     }
1750                     // fall through for ble-only chips
1751 
1752                 case 2:
1753                     log_info("HCI_STATE_HALTING, calling sleep\n");
1754 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1755                     // don't actually go to sleep, if H4 supports power management
1756                     if (bt_control_iphone_power_management_enabled()){
1757                         // SLEEP MODE reached
1758                         hci_stack->state = HCI_STATE_SLEEPING;
1759                         hci_emit_state();
1760                         break;
1761                     }
1762 #endif
1763                     // switch mode
1764                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
1765                     hci_emit_state();
1766                     break;
1767 
1768                 default:
1769                     break;
1770             }
1771             break;
1772 
1773         default:
1774             break;
1775     }
1776 }
1777 
1778 int hci_send_cmd_packet(uint8_t *packet, int size){
1779     bd_addr_t addr;
1780     hci_connection_t * conn;
1781     // house-keeping
1782 
1783     // create_connection?
1784     if (IS_COMMAND(packet, hci_create_connection)){
1785         bt_flip_addr(addr, &packet[3]);
1786         log_info("Create_connection to %s\n", bd_addr_to_str(addr));
1787 
1788         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1789         if (!conn){
1790             conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_CLASSIC);
1791             if (!conn){
1792                 // notify client that alloc failed
1793                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
1794                 return 0; // don't sent packet to controller
1795             }
1796             conn->state = SEND_CREATE_CONNECTION;
1797         }
1798         log_info("conn state %u", conn->state);
1799         switch (conn->state){
1800             // if connection active exists
1801             case OPEN:
1802                 // and OPEN, emit connection complete command, don't send to controller
1803                 hci_emit_connection_complete(conn, 0);
1804                 return 0;
1805             case SEND_CREATE_CONNECTION:
1806                 // connection created by hci, e.g. dedicated bonding
1807                 break;
1808             default:
1809                 // otherwise, just ignore as it is already in the open process
1810                 return 0;
1811         }
1812         conn->state = SENT_CREATE_CONNECTION;
1813     }
1814 
1815     if (IS_COMMAND(packet, hci_link_key_request_reply)){
1816         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
1817     }
1818     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
1819         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
1820     }
1821 
1822     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
1823         if (hci_stack->remote_device_db){
1824             bt_flip_addr(addr, &packet[3]);
1825             hci_stack->remote_device_db->delete_link_key(&addr);
1826         }
1827     }
1828 
1829     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
1830     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
1831         bt_flip_addr(addr, &packet[3]);
1832         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1833         if (conn){
1834             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
1835         }
1836     }
1837 
1838     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
1839     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
1840     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
1841     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
1842         bt_flip_addr(addr, &packet[3]);
1843         conn = hci_connection_for_bd_addr_and_type(&addr, BD_ADDR_TYPE_CLASSIC);
1844         if (conn){
1845             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
1846         }
1847     }
1848 
1849 #ifdef HAVE_BLE
1850     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
1851         hci_stack->adv_addr_type = packet[8];
1852     }
1853     if (IS_COMMAND(packet, hci_le_set_random_address)){
1854         bt_flip_addr(hci_stack->adv_address, &packet[3]);
1855     }
1856 #endif
1857 
1858     hci_stack->num_cmd_packets--;
1859     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
1860 
1861     // free packet buffer for synchronous transport implementations
1862     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
1863         hci_stack->hci_packet_buffer_reserved = 0;
1864     }
1865 
1866     return err;
1867 }
1868 
1869 // disconnect because of security block
1870 void hci_disconnect_security_block(hci_con_handle_t con_handle){
1871     hci_connection_t * connection = hci_connection_for_handle(con_handle);
1872     if (!connection) return;
1873     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
1874 }
1875 
1876 
1877 // Configure Secure Simple Pairing
1878 
1879 // enable will enable SSP during init
1880 void hci_ssp_set_enable(int enable){
1881     hci_stack->ssp_enable = enable;
1882 }
1883 
1884 int hci_local_ssp_activated(){
1885     return hci_ssp_supported() && hci_stack->ssp_enable;
1886 }
1887 
1888 // if set, BTstack will respond to io capability request using authentication requirement
1889 void hci_ssp_set_io_capability(int io_capability){
1890     hci_stack->ssp_io_capability = io_capability;
1891 }
1892 void hci_ssp_set_authentication_requirement(int authentication_requirement){
1893     hci_stack->ssp_authentication_requirement = authentication_requirement;
1894 }
1895 
1896 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
1897 void hci_ssp_set_auto_accept(int auto_accept){
1898     hci_stack->ssp_auto_accept = auto_accept;
1899 }
1900 
1901 /**
1902  * pre: numcmds >= 0 - it's allowed to send a command to the controller
1903  */
1904 int hci_send_cmd(const hci_cmd_t *cmd, ...){
1905     va_list argptr;
1906     va_start(argptr, cmd);
1907     uint16_t size = hci_create_cmd_internal(hci_stack->hci_packet_buffer, cmd, argptr);
1908     va_end(argptr);
1909     return hci_send_cmd_packet(hci_stack->hci_packet_buffer, size);
1910 }
1911 
1912 // Create various non-HCI events.
1913 // TODO: generalize, use table similar to hci_create_command
1914 
1915 void hci_emit_state(){
1916     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
1917     uint8_t event[3];
1918     event[0] = BTSTACK_EVENT_STATE;
1919     event[1] = sizeof(event) - 2;
1920     event[2] = hci_stack->state;
1921     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1922     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1923 }
1924 
1925 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
1926     uint8_t event[13];
1927     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
1928     event[1] = sizeof(event) - 2;
1929     event[2] = status;
1930     bt_store_16(event, 3, conn->con_handle);
1931     bt_flip_addr(&event[5], conn->address);
1932     event[11] = 1; // ACL connection
1933     event[12] = 0; // encryption disabled
1934     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
1935     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1936 }
1937 
1938 void hci_emit_le_connection_complete(hci_connection_t *conn, uint8_t status){
1939     uint8_t event[21];
1940     event[0] = HCI_EVENT_LE_META;
1941     event[1] = sizeof(event) - 2;
1942     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
1943     event[3] = status;
1944     bt_store_16(event, 4, conn->con_handle);
1945     event[6] = 0; // TODO: role
1946     event[7] = conn->address_type;
1947     bt_flip_addr(&event[8], conn->address);
1948     bt_store_16(event, 14, 0); // interval
1949     bt_store_16(event, 16, 0); // latency
1950     bt_store_16(event, 18, 0); // supervision timeout
1951     event[20] = 0; // master clock accuracy
1952     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
1953     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1954 }
1955 
1956 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
1957     uint8_t event[6];
1958     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
1959     event[1] = sizeof(event) - 2;
1960     event[2] = 0; // status = OK
1961     bt_store_16(event, 3, handle);
1962     event[5] = reason;
1963     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
1964     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1965 }
1966 
1967 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
1968     if (disable_l2cap_timeouts) return;
1969     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
1970     uint8_t event[4];
1971     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
1972     event[1] = sizeof(event) - 2;
1973     bt_store_16(event, 2, conn->con_handle);
1974     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event));
1975     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1976 }
1977 
1978 void hci_emit_nr_connections_changed(){
1979     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
1980     uint8_t event[3];
1981     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
1982     event[1] = sizeof(event) - 2;
1983     event[2] = nr_hci_connections();
1984     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1985     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1986 }
1987 
1988 void hci_emit_hci_open_failed(){
1989     log_info("BTSTACK_EVENT_POWERON_FAILED");
1990     uint8_t event[2];
1991     event[0] = BTSTACK_EVENT_POWERON_FAILED;
1992     event[1] = sizeof(event) - 2;
1993     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1994     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1995 }
1996 
1997 #ifndef EMBEDDED
1998 void hci_emit_btstack_version() {
1999     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
2000     uint8_t event[6];
2001     event[0] = BTSTACK_EVENT_VERSION;
2002     event[1] = sizeof(event) - 2;
2003     event[2] = BTSTACK_MAJOR;
2004     event[3] = BTSTACK_MINOR;
2005     bt_store_16(event, 4, BTSTACK_REVISION);
2006     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2007     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2008 }
2009 #endif
2010 
2011 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
2012     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
2013     uint8_t event[3];
2014     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
2015     event[1] = sizeof(event) - 2;
2016     event[2] = enabled;
2017     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2018     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2019 }
2020 
2021 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
2022     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
2023     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
2024     event[1] = sizeof(event) - 2 - 1;
2025     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
2026     bt_flip_addr(&event[3], *addr);
2027     memcpy(&event[9], name, 248);
2028 
2029     event[9+248] = 0;   // assert \0 for log_info
2030     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
2031 
2032     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
2033     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
2034 }
2035 
2036 void hci_emit_discoverable_enabled(uint8_t enabled){
2037     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
2038     uint8_t event[3];
2039     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
2040     event[1] = sizeof(event) - 2;
2041     event[2] = enabled;
2042     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2043     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2044 }
2045 
2046 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
2047     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
2048     uint8_t event[5];
2049     int pos = 0;
2050     event[pos++] = GAP_SECURITY_LEVEL;
2051     event[pos++] = sizeof(event) - 2;
2052     bt_store_16(event, 2, con_handle);
2053     pos += 2;
2054     event[pos++] = level;
2055     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2056     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2057 }
2058 
2059 void hci_emit_dedicated_bonding_result(hci_connection_t * connection, uint8_t status){
2060     log_info("hci_emit_dedicated_bonding_result %u ", status);
2061     uint8_t event[9];
2062     int pos = 0;
2063     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
2064     event[pos++] = sizeof(event) - 2;
2065     event[pos++] = status;
2066     bt_flip_addr( * (bd_addr_t *) &event[pos], connection->address);
2067     pos += 6;
2068     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
2069     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
2070 }
2071 
2072 // query if remote side supports SSP
2073 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
2074     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2075     if (!connection) return 0;
2076     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
2077 }
2078 
2079 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
2080     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
2081 }
2082 
2083 // GAP API
2084 /**
2085  * @bbrief enable/disable bonding. default is enabled
2086  * @praram enabled
2087  */
2088 void gap_set_bondable_mode(int enable){
2089     hci_stack->bondable = enable ? 1 : 0;
2090 }
2091 
2092 /**
2093  * @brief map link keys to security levels
2094  */
2095 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
2096     switch (link_key_type){
2097         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
2098             return LEVEL_4;
2099         case COMBINATION_KEY:
2100         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
2101             return LEVEL_3;
2102         default:
2103             return LEVEL_2;
2104     }
2105 }
2106 
2107 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
2108     if (!connection) return LEVEL_0;
2109     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
2110     return gap_security_level_for_link_key_type(connection->link_key_type);
2111 }
2112 
2113 
2114 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
2115     printf("gap_mitm_protection_required_for_security_level %u\n", level);
2116     return level > LEVEL_2;
2117 }
2118 
2119 /**
2120  * @brief get current security level
2121  */
2122 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
2123     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2124     if (!connection) return LEVEL_0;
2125     return gap_security_level_for_connection(connection);
2126 }
2127 
2128 /**
2129  * @brief request connection to device to
2130  * @result GAP_AUTHENTICATION_RESULT
2131  */
2132 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
2133     hci_connection_t * connection = hci_connection_for_handle(con_handle);
2134     if (!connection){
2135         hci_emit_security_level(con_handle, LEVEL_0);
2136         return;
2137     }
2138     gap_security_level_t current_level = gap_security_level(con_handle);
2139     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
2140     if (current_level >= requested_level){
2141         hci_emit_security_level(con_handle, current_level);
2142         return;
2143     }
2144 
2145     connection->requested_security_level = requested_level;
2146 
2147     // would enabling ecnryption suffice (>= LEVEL_2)?
2148     if (hci_stack->remote_device_db){
2149         link_key_type_t link_key_type;
2150         link_key_t      link_key;
2151         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2152             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2153                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2154                 return;
2155             }
2156         }
2157     }
2158 
2159     // try to authenticate connection
2160     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2161     hci_run();
2162 }
2163 
2164 /**
2165  * @brief start dedicated bonding with device. disconnect after bonding
2166  * @param device
2167  * @param request MITM protection
2168  * @result GAP_DEDICATED_BONDING_COMPLETE
2169  */
2170 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2171 
2172     // create connection state machine
2173     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_CLASSIC);
2174 
2175     if (!connection){
2176         return BTSTACK_MEMORY_ALLOC_FAILED;
2177     }
2178 
2179     // delete linkn key
2180     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2181 
2182     // configure LEVEL_2/3, dedicated bonding
2183     connection->state = SEND_CREATE_CONNECTION;
2184     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2185     printf("gap_dedicated_bonding, mitm %u -> level %u\n", mitm_protection_required, connection->requested_security_level);
2186     connection->bonding_flags = BONDING_DEDICATED;
2187 
2188     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2189 
2190     // handle: connnection failure (connection complete != ok)
2191     // handle: authentication failure
2192     // handle: disconnect on done
2193 
2194     hci_run();
2195 
2196     return 0;
2197 }
2198 
2199 void gap_set_local_name(const char * local_name){
2200     hci_stack->local_name = local_name;
2201 }
2202 
2203 le_command_status_t le_central_start_scan(){
2204     if (hci_stack->le_scanning_state == LE_SCANNING) return BLE_PERIPHERAL_OK;
2205     hci_stack->le_scanning_state = LE_START_SCAN;
2206     hci_run();
2207     return BLE_PERIPHERAL_OK;
2208 }
2209 
2210 le_command_status_t le_central_stop_scan(){
2211     if ( hci_stack->le_scanning_state == LE_SCAN_IDLE) return BLE_PERIPHERAL_OK;
2212     hci_stack->le_scanning_state = LE_STOP_SCAN;
2213     hci_run();
2214     return BLE_PERIPHERAL_OK;
2215 }
2216 
2217 
2218 le_command_status_t le_central_connect(bd_addr_t * addr, bd_addr_type_t addr_type){
2219     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2220     log_info("le_central_connect, conn struct %p", conn);
2221     if (!conn){
2222         conn = create_connection_for_bd_addr_and_type(*addr, addr_type);
2223         if (!conn){
2224             // notify client that alloc failed
2225             hci_emit_le_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
2226             return BLE_PERIPHERAL_NOT_CONNECTED; // don't sent packet to controller
2227         }
2228         conn->state = SEND_CREATE_CONNECTION;
2229         log_info("le_central_connect, state %u", conn->state);
2230         hci_run();
2231         return BLE_PERIPHERAL_OK;
2232     }
2233 
2234     if (!hci_is_le_connection(conn) ||
2235         conn->state == SEND_CREATE_CONNECTION ||
2236         conn->state == SENT_CREATE_CONNECTION) {
2237         hci_emit_le_connection_complete(conn, ERROR_CODE_COMMAND_DISALLOWED);
2238         return BLE_PERIPHERAL_IN_WRONG_STATE;
2239     }
2240 
2241     log_info("le_central_connect, state %u", conn->state);
2242     hci_emit_le_connection_complete(conn, 0);
2243     hci_run();
2244     return BLE_PERIPHERAL_OK;
2245 }
2246 
2247 // @assumption: only a single outgoing LE Connection exists
2248 static hci_connection_t * le_central_get_outgoing_connection(){
2249     linked_item_t *it;
2250     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
2251         hci_connection_t * conn = (hci_connection_t *) it;
2252         if (!hci_is_le_connection(conn)) continue;
2253         switch (conn->state){
2254             case SEND_CREATE_CONNECTION:
2255             case SENT_CREATE_CONNECTION:
2256                 return conn;
2257             default:
2258                 break;
2259         };
2260     }
2261     return NULL;
2262 }
2263 
2264 le_command_status_t le_central_connect_cancel(){
2265     hci_connection_t * conn = le_central_get_outgoing_connection();
2266     switch (conn->state){
2267         case SEND_CREATE_CONNECTION:
2268             // skip sending create connection and emit event instead
2269             hci_emit_le_connection_complete(conn, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
2270             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
2271             btstack_memory_hci_connection_free( conn );
2272             break;
2273         case SENT_CREATE_CONNECTION:
2274             // request to send cancel connection
2275             conn->state = SEND_CANCEL_CONNECTION;
2276             hci_run();
2277             break;
2278         default:
2279             break;
2280     }
2281     return BLE_PERIPHERAL_OK;
2282 }
2283 
2284 le_command_status_t gap_disconnect(hci_con_handle_t handle){
2285     hci_connection_t * conn = hci_connection_for_handle(handle);
2286     if (!conn){
2287         hci_emit_disconnection_complete(handle, 0);
2288         return BLE_PERIPHERAL_OK;
2289     }
2290     conn->state = SEND_DISCONNECT;
2291     hci_run();
2292     return BLE_PERIPHERAL_OK;
2293 }
2294