xref: /btstack/src/hci.c (revision e0dbca836d24c7b5fd8ef62976cf5e397ef40224)
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 "config.h"
45 
46 #include "hci.h"
47 
48 #include <stdarg.h>
49 #include <string.h>
50 #include <stdio.h>
51 
52 #ifndef EMBEDDED
53 #include <unistd.h> // gethostbyname
54 #include <btstack/version.h>
55 #endif
56 
57 #include "btstack_memory.h"
58 #include "debug.h"
59 #include "hci_dump.h"
60 
61 #include <btstack/hci_cmds.h>
62 
63 #define HCI_CONNECTION_TIMEOUT_MS 10000
64 
65 #define HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP 10
66 
67 #ifdef USE_BLUETOOL
68 #include "bt_control_iphone.h"
69 #endif
70 
71 static void hci_update_scan_enable(void);
72 
73 // the STACK is here
74 static hci_stack_t       hci_stack;
75 
76 /**
77  * get connection for a given handle
78  *
79  * @return connection OR NULL, if not found
80  */
81 hci_connection_t * connection_for_handle(hci_con_handle_t con_handle){
82     linked_item_t *it;
83     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
84         if ( ((hci_connection_t *) it)->con_handle == con_handle){
85             return (hci_connection_t *) it;
86         }
87     }
88     return NULL;
89 }
90 
91 static void hci_connection_timeout_handler(timer_source_t *timer){
92     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
93 #ifdef HAVE_TIME
94     struct timeval tv;
95     gettimeofday(&tv, NULL);
96     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
97         // connections might be timed out
98         hci_emit_l2cap_check_timeout(connection);
99     }
100 #endif
101 #ifdef HAVE_TICK
102     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
103         // connections might be timed out
104         hci_emit_l2cap_check_timeout(connection);
105     }
106 #endif
107     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
108     run_loop_add_timer(timer);
109 }
110 
111 static void hci_connection_timestamp(hci_connection_t *connection){
112 #ifdef HAVE_TIME
113     gettimeofday(&connection->timestamp, NULL);
114 #endif
115 #ifdef HAVE_TICK
116     connection->timestamp = embedded_get_ticks();
117 #endif
118 }
119 
120 /**
121  * create connection for given address
122  *
123  * @return connection OR NULL, if no memory left
124  */
125 static hci_connection_t * create_connection_for_addr(bd_addr_t addr){
126     hci_connection_t * conn = (hci_connection_t *) btstack_memory_hci_connection_get();
127     if (!conn) return NULL;
128     BD_ADDR_COPY(conn->address, addr);
129     conn->con_handle = 0xffff;
130     conn->authentication_flags = AUTH_FLAGS_NONE;
131     linked_item_set_user(&conn->timeout.item, conn);
132     conn->timeout.process = hci_connection_timeout_handler;
133     hci_connection_timestamp(conn);
134     conn->acl_recombination_length = 0;
135     conn->acl_recombination_pos = 0;
136     conn->num_acl_packets_sent = 0;
137     linked_list_add(&hci_stack.connections, (linked_item_t *) conn);
138     return conn;
139 }
140 
141 /**
142  * get connection for given address
143  *
144  * @return connection OR NULL, if not found
145  */
146 static hci_connection_t * connection_for_address(bd_addr_t address){
147     linked_item_t *it;
148     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
149         if ( ! BD_ADDR_CMP( ((hci_connection_t *) it)->address, address) ){
150             return (hci_connection_t *) it;
151         }
152     }
153     return NULL;
154 }
155 
156 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
157     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
158 }
159 
160 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
161     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
162 }
163 
164 
165 /**
166  * add authentication flags and reset timer
167  */
168 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
169     bd_addr_t addr;
170     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
171     hci_connection_t * conn = connection_for_address(addr);
172     if (conn) {
173         connectionSetAuthenticationFlags(conn, flags);
174         hci_connection_timestamp(conn);
175     }
176 }
177 
178 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
179     hci_connection_t * conn = connection_for_handle(handle);
180     if (!conn) return 0;
181     if (!conn->authentication_flags) return 0;
182     if (conn->authentication_flags & SENT_LINK_KEY_REPLY) return 0;
183     if (conn->authentication_flags & RECV_LINK_KEY_NOTIFICATION) return 0;
184     return 1;
185 }
186 
187 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
188     if (hci_stack.remote_device_db) {
189         hci_stack.remote_device_db->delete_link_key(addr);
190     }
191 }
192 
193 
194 /**
195  * count connections
196  */
197 static int nr_hci_connections(void){
198     int count = 0;
199     linked_item_t *it;
200     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next, count++);
201     return count;
202 }
203 
204 /**
205  * Dummy handler called by HCI
206  */
207 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
208 }
209 
210 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
211     hci_connection_t * connection = connection_for_handle(handle);
212     if (!connection) {
213         log_error("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
214         return 0;
215     }
216     return connection->num_acl_packets_sent;
217 }
218 
219 uint8_t hci_number_free_acl_slots(){
220     uint8_t free_slots = hci_stack.total_num_acl_packets;
221     linked_item_t *it;
222     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
223         hci_connection_t * connection = (hci_connection_t *) it;
224         if (free_slots < connection->num_acl_packets_sent) {
225             log_error("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
226             return 0;
227         }
228         free_slots -= connection->num_acl_packets_sent;
229     }
230     return free_slots;
231 }
232 
233 int hci_can_send_packet_now(uint8_t packet_type){
234 
235     // check for async hci transport implementations
236     if (hci_stack.hci_transport->can_send_packet_now){
237         if (!hci_stack.hci_transport->can_send_packet_now(packet_type)){
238             return 0;
239         }
240     }
241 
242     // check regular Bluetooth flow control
243     switch (packet_type) {
244         case HCI_ACL_DATA_PACKET:
245             return hci_number_free_acl_slots();
246         case HCI_COMMAND_DATA_PACKET:
247             return hci_stack.num_cmd_packets;
248         default:
249             return 0;
250     }
251 }
252 
253 int hci_send_acl_packet(uint8_t *packet, int size){
254 
255     // check for free places on BT module
256     if (!hci_number_free_acl_slots()) return BTSTACK_ACL_BUFFERS_FULL;
257 
258     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
259     hci_connection_t *connection = connection_for_handle( con_handle);
260     if (!connection) return 0;
261     hci_connection_timestamp(connection);
262 
263     // count packet
264     connection->num_acl_packets_sent++;
265     // log_info("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
266 
267     // send packet
268     int err = hci_stack.hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
269 
270     return err;
271 }
272 
273 static void acl_handler(uint8_t *packet, int size){
274 
275     // get info
276     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
277     hci_connection_t *conn      = connection_for_handle(con_handle);
278     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
279     uint16_t acl_length         = READ_ACL_LENGTH(packet);
280 
281     // ignore non-registered handle
282     if (!conn){
283         log_error( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
284         return;
285     }
286 
287     // update idle timestamp
288     hci_connection_timestamp(conn);
289 
290     // handle different packet types
291     switch (acl_flags & 0x03) {
292 
293         case 0x01: // continuation fragment
294 
295             // sanity check
296             if (conn->acl_recombination_pos == 0) {
297                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
298                 return;
299             }
300 
301             // append fragment payload (header already stored)
302             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
303             conn->acl_recombination_pos += acl_length;
304 
305             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n", acl_length,
306             //        conn->acl_recombination_pos, conn->acl_recombination_length);
307 
308             // forward complete L2CAP packet if complete.
309             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
310 
311                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
312                 // reset recombination buffer
313                 conn->acl_recombination_length = 0;
314                 conn->acl_recombination_pos = 0;
315             }
316             break;
317 
318         case 0x02: { // first fragment
319 
320             // sanity check
321             if (conn->acl_recombination_pos) {
322                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
323                 return;
324             }
325 
326             // peek into L2CAP packet!
327             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
328 
329             // log_error( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
330 
331             // compare fragment size to L2CAP packet size
332             if (acl_length >= l2cap_length + 4){
333 
334                 // forward fragment as L2CAP packet
335                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
336 
337             } else {
338                 // store first fragment and tweak acl length for complete package
339                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
340                 conn->acl_recombination_pos    = acl_length + 4;
341                 conn->acl_recombination_length = l2cap_length;
342                 bt_store_16(conn->acl_recombination_buffer, 2, l2cap_length +4);
343             }
344             break;
345 
346         }
347         default:
348             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
349             return;
350     }
351 
352     // execute main loop
353     hci_run();
354 }
355 
356 static void hci_shutdown_connection(hci_connection_t *conn){
357     log_info("Connection closed: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
358 
359     // cancel all l2cap connections
360     hci_emit_disconnection_complete(conn->con_handle, 0x16);    // terminated by local host
361 
362     run_loop_remove_timer(&conn->timeout);
363 
364     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
365     btstack_memory_hci_connection_free( conn );
366 
367     // now it's gone
368     hci_emit_nr_connections_changed();
369 }
370 
371 static const uint16_t packet_type_sizes[] = {
372     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
373     HCI_ACL_DH1_SIZE, 0, 0, 0,
374     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
375     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
376 };
377 
378 static uint16_t hci_acl_packet_types_for_buffer_size(uint16_t buffer_size){
379     uint16_t packet_types = 0;
380     int i;
381     for (i=0;i<16;i++){
382         if (packet_type_sizes[i] == 0) continue;
383         if (packet_type_sizes[i] <= buffer_size){
384             packet_types |= 1 << i;
385         }
386     }
387     // flip bits for "may not be used"
388     packet_types ^= 0x3306;
389     return packet_types;
390 }
391 
392 uint16_t hci_usable_acl_packet_types(void){
393     return hci_stack.packet_types;
394 }
395 
396 uint8_t* hci_get_outgoing_acl_packet_buffer(void){
397     // hci packet buffer is >= acl data packet length
398     return hci_stack.hci_packet_buffer;
399 }
400 
401 uint16_t hci_max_acl_data_packet_length(){
402     return hci_stack.acl_data_packet_length;
403 }
404 
405 // avoid huge local variables
406 #ifndef EMBEDDED
407 static device_name_t device_name;
408 #endif
409 static void event_handler(uint8_t *packet, int size){
410     bd_addr_t addr;
411     uint8_t link_type;
412     hci_con_handle_t handle;
413     hci_connection_t * conn;
414     int i;
415 
416     // printf("HCI:EVENT:%02x\n", packet[0]);
417 
418     switch (packet[0]) {
419 
420         case HCI_EVENT_COMMAND_COMPLETE:
421             // get num cmd packets
422             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u\n", hci_stack.num_cmd_packets, packet[2]);
423             hci_stack.num_cmd_packets = packet[2];
424 
425             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
426                 // from offset 5
427                 // status
428                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
429                 hci_stack.acl_data_packet_length = READ_BT_16(packet, 6);
430                 // ignore: SCO data packet len (8)
431                 hci_stack.total_num_acl_packets  = packet[9];
432                 // ignore: total num SCO packets
433                 if (hci_stack.state == HCI_STATE_INITIALIZING){
434                     // determine usable ACL payload size
435                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack.acl_data_packet_length){
436                         hci_stack.acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
437                     }
438                     // determine usable ACL packet types
439                     hci_stack.packet_types = hci_acl_packet_types_for_buffer_size(hci_stack.acl_data_packet_length);
440 
441                     log_info("hci_read_buffer_size: used size %u, count %u, packet types %04x\n",
442                              hci_stack.acl_data_packet_length, hci_stack.total_num_acl_packets, hci_stack.packet_types);
443                 }
444             }
445             // Dump local address
446             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
447                 bt_flip_addr(hci_stack.local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
448                 log_info("Local Address, Status: 0x%02x: Addr: %s\n",
449                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack.local_bd_addr));
450             }
451             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
452                 hci_emit_discoverable_enabled(hci_stack.discoverable);
453             }
454             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
455                 memcpy(hci_stack.local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], 8);
456                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
457                     hci_stack.local_supported_features[0], hci_stack.local_supported_features[1],
458                     hci_stack.local_supported_features[2], hci_stack.local_supported_features[3],
459                     hci_stack.local_supported_features[4], hci_stack.local_supported_features[5],
460                     hci_stack.local_supported_features[6], hci_stack.local_supported_features[7]);
461             }
462             break;
463 
464         case HCI_EVENT_COMMAND_STATUS:
465             // get num cmd packets
466             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u\n", hci_stack.num_cmd_packets, packet[3]);
467             hci_stack.num_cmd_packets = packet[3];
468             break;
469 
470         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
471             for (i=0; i<packet[2];i++){
472                 handle = READ_BT_16(packet, 3 + 2*i);
473                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
474                 conn = connection_for_handle(handle);
475                 if (!conn){
476                     log_error("hci_number_completed_packet lists unused con handle %u\n", handle);
477                     continue;
478                 }
479                 conn->num_acl_packets_sent -= num_packets;
480                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
481             }
482             break;
483 
484         case HCI_EVENT_CONNECTION_REQUEST:
485             bt_flip_addr(addr, &packet[2]);
486             // TODO: eval COD 8-10
487             link_type = packet[11];
488             log_info("Connection_incoming: %s, type %u\n", bd_addr_to_str(addr), link_type);
489             if (link_type == 1) { // ACL
490                 conn = connection_for_address(addr);
491                 if (!conn) {
492                     conn = create_connection_for_addr(addr);
493                 }
494                 if (!conn) {
495                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
496                     hci_stack.decline_reason = 0x0d;
497                     BD_ADDR_COPY(hci_stack.decline_addr, addr);
498                     break;
499                 }
500                 conn->state = RECEIVED_CONNECTION_REQUEST;
501                 hci_run();
502             } else {
503                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
504                 hci_stack.decline_reason = 0x0a;
505                 BD_ADDR_COPY(hci_stack.decline_addr, addr);
506             }
507             break;
508 
509         case HCI_EVENT_CONNECTION_COMPLETE:
510             // Connection management
511             bt_flip_addr(addr, &packet[5]);
512             log_info("Connection_complete (status=%u) %s\n", packet[2], bd_addr_to_str(addr));
513             conn = connection_for_address(addr);
514             if (conn) {
515                 if (!packet[2]){
516                     conn->state = OPEN;
517                     conn->con_handle = READ_BT_16(packet, 3);
518 
519                     // restart timer
520                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
521                     run_loop_add_timer(&conn->timeout);
522 
523                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
524 
525                     hci_emit_nr_connections_changed();
526                 } else {
527                     // connection failed, remove entry
528                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
529                     btstack_memory_hci_connection_free( conn );
530 
531                     // if authentication error, also delete link key
532                     if (packet[2] == 0x05) {
533                         hci_drop_link_key_for_bd_addr(&addr);
534                     }
535                 }
536             }
537             break;
538 
539         case HCI_EVENT_LINK_KEY_REQUEST:
540             log_info("HCI_EVENT_LINK_KEY_REQUEST\n");
541             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
542             if (!hci_stack.remote_device_db) break;
543             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
544             hci_run();
545             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
546             return;
547 
548         case HCI_EVENT_LINK_KEY_NOTIFICATION:
549             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_NOTIFICATION);
550             if (!hci_stack.remote_device_db) break;
551             bt_flip_addr(addr, &packet[2]);
552             hci_stack.remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8]);
553             // still forward event to allow dismiss of pairing dialog
554             break;
555 
556         case HCI_EVENT_PIN_CODE_REQUEST:
557             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_PIN_CODE_REQUEST);
558             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
559             if (!hci_stack.remote_device_db) break;
560             bt_flip_addr(addr, &packet[2]);
561             hci_stack.remote_device_db->delete_link_key(&addr);
562             break;
563 
564 #ifndef EMBEDDED
565         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
566             if (!hci_stack.remote_device_db) break;
567             if (packet[2]) break; // status not ok
568             bt_flip_addr(addr, &packet[3]);
569             // fix for invalid remote names - terminate on 0xff
570             for (i=0; i<248;i++){
571                 if (packet[9+i] == 0xff){
572                     packet[9+i] = 0;
573                     break;
574                 }
575             }
576             memset(&device_name, 0, sizeof(device_name_t));
577             strncpy((char*) device_name, (char*) &packet[9], 248);
578             hci_stack.remote_device_db->put_name(&addr, &device_name);
579             break;
580 
581         case HCI_EVENT_INQUIRY_RESULT:
582         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
583             if (!hci_stack.remote_device_db) break;
584             // first send inq result packet
585             hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
586             // then send cached remote names
587             for (i=0; i<packet[2];i++){
588                 bt_flip_addr(addr, &packet[3+i*6]);
589                 if (hci_stack.remote_device_db->get_name(&addr, &device_name)){
590                     hci_emit_remote_name_cached(&addr, &device_name);
591                 }
592             }
593             return;
594 #endif
595 
596         case HCI_EVENT_DISCONNECTION_COMPLETE:
597             if (!packet[2]){
598                 handle = READ_BT_16(packet, 3);
599                 hci_connection_t * conn = connection_for_handle(handle);
600                 if (conn) {
601                     hci_shutdown_connection(conn);
602                 }
603             }
604             break;
605 
606         case HCI_EVENT_HARDWARE_ERROR:
607             if(hci_stack.control->hw_error){
608                 (*hci_stack.control->hw_error)();
609             }
610             break;
611 
612 #ifdef HAVE_BLE
613         case HCI_EVENT_LE_META:
614             switch (packet[2]) {
615                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
616                     // Connection management
617                     bt_flip_addr(addr, &packet[8]);
618                     log_info("LE Connection_complete (status=%u) %s\n", packet[3], bd_addr_to_str(addr));
619                     // LE connections are auto-accepted, so just create a connection if there isn't one already
620                     conn = connection_for_address(addr);
621                     if (packet[3]){
622                         if (conn){
623                             // outgoing connection failed, remove entry
624                             linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
625                             btstack_memory_hci_connection_free( conn );
626 
627                         }
628                         // if authentication error, also delete link key
629                         if (packet[3] == 0x05) {
630                             hci_drop_link_key_for_bd_addr(&addr);
631                         }
632                         break;
633                     }
634                     if (!conn){
635                         conn = create_connection_for_addr(addr);
636                     }
637                     if (!conn){
638                         // no memory
639                         break;
640                     }
641 
642                     conn->state = OPEN;
643                     conn->con_handle = READ_BT_16(packet, 4);
644 
645                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
646 
647                     // restart timer
648                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
649                     // run_loop_add_timer(&conn->timeout);
650 
651                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
652 
653                     hci_emit_nr_connections_changed();
654                     break;
655 
656                 default:
657                     break;
658             }
659             break;
660 #endif
661 
662         default:
663             break;
664     }
665 
666     // handle BT initialization
667     if (hci_stack.state == HCI_STATE_INITIALIZING){
668         // handle H4 synchronization loss on restart
669         // if (hci_stack.substate == 1 && packet[0] == HCI_EVENT_HARDWARE_ERROR){
670         //    hci_stack.substate = 0;
671         // }
672         // handle normal init sequence
673         if (hci_stack.substate % 2){
674             // odd: waiting for event
675             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
676                 hci_stack.substate++;
677             }
678         }
679     }
680 
681     // help with BT sleep
682     if (hci_stack.state == HCI_STATE_FALLING_ASLEEP
683         && hci_stack.substate == 1
684         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
685         hci_stack.substate++;
686     }
687 
688     hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
689 
690 	// execute main loop
691 	hci_run();
692 }
693 
694 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
695     switch (packet_type) {
696         case HCI_EVENT_PACKET:
697             event_handler(packet, size);
698             break;
699         case HCI_ACL_DATA_PACKET:
700             acl_handler(packet, size);
701             break;
702         default:
703             break;
704     }
705 }
706 
707 /** Register HCI packet handlers */
708 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
709     hci_stack.packet_handler = handler;
710 }
711 
712 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
713 
714     // reference to use transport layer implementation
715     hci_stack.hci_transport = transport;
716 
717     // references to used control implementation
718     hci_stack.control = control;
719 
720     // reference to used config
721     hci_stack.config = config;
722 
723     // no connections yet
724     hci_stack.connections = NULL;
725     hci_stack.discoverable = 0;
726     hci_stack.connectable = 0;
727 
728     // no pending cmds
729     hci_stack.decline_reason = 0;
730     hci_stack.new_scan_enable_value = 0xff;
731 
732     // higher level handler
733     hci_stack.packet_handler = dummy_handler;
734 
735     // store and open remote device db
736     hci_stack.remote_device_db = remote_device_db;
737     if (hci_stack.remote_device_db) {
738         hci_stack.remote_device_db->open();
739     }
740 
741     // max acl payload size defined in config.h
742     hci_stack.acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
743 
744     // register packet handlers with transport
745     transport->register_packet_handler(&packet_handler);
746 
747     hci_stack.state = HCI_STATE_OFF;
748 
749     // class of device
750     hci_stack.class_of_device = 0x007a020c; // Smartphone
751 }
752 
753 void hci_close(){
754     // close remote device db
755     if (hci_stack.remote_device_db) {
756         hci_stack.remote_device_db->close();
757     }
758     while (hci_stack.connections) {
759         hci_shutdown_connection((hci_connection_t *) hci_stack.connections);
760 }
761     hci_power_control(HCI_POWER_OFF);
762 }
763 
764 // State-Module-Driver overview
765 // state                    module  low-level
766 // HCI_STATE_OFF             off      close
767 // HCI_STATE_INITIALIZING,   on       open
768 // HCI_STATE_WORKING,        on       open
769 // HCI_STATE_HALTING,        on       open
770 // HCI_STATE_SLEEPING,    off/sleep   close
771 // HCI_STATE_FALLING_ASLEEP  on       open
772 
773 static int hci_power_control_on(void){
774 
775     // power on
776     int err = 0;
777     if (hci_stack.control && hci_stack.control->on){
778         err = (*hci_stack.control->on)(hci_stack.config);
779     }
780     if (err){
781         log_error( "POWER_ON failed\n");
782         hci_emit_hci_open_failed();
783         return err;
784     }
785 
786     // open low-level device
787     err = hci_stack.hci_transport->open(hci_stack.config);
788     if (err){
789         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
790         if (hci_stack.control && hci_stack.control->off){
791             (*hci_stack.control->off)(hci_stack.config);
792         }
793         hci_emit_hci_open_failed();
794         return err;
795     }
796     return 0;
797 }
798 
799 static void hci_power_control_off(void){
800 
801     log_info("hci_power_control_off\n");
802 
803     // close low-level device
804     hci_stack.hci_transport->close(hci_stack.config);
805 
806     log_info("hci_power_control_off - hci_transport closed\n");
807 
808     // power off
809     if (hci_stack.control && hci_stack.control->off){
810         (*hci_stack.control->off)(hci_stack.config);
811     }
812 
813     log_info("hci_power_control_off - control closed\n");
814 
815     hci_stack.state = HCI_STATE_OFF;
816 }
817 
818 static void hci_power_control_sleep(void){
819 
820     log_info("hci_power_control_sleep\n");
821 
822 #if 0
823     // don't close serial port during sleep
824 
825     // close low-level device
826     hci_stack.hci_transport->close(hci_stack.config);
827 #endif
828 
829     // sleep mode
830     if (hci_stack.control && hci_stack.control->sleep){
831         (*hci_stack.control->sleep)(hci_stack.config);
832     }
833 
834     hci_stack.state = HCI_STATE_SLEEPING;
835 }
836 
837 static int hci_power_control_wake(void){
838 
839     log_info("hci_power_control_wake\n");
840 
841     // wake on
842     if (hci_stack.control && hci_stack.control->wake){
843         (*hci_stack.control->wake)(hci_stack.config);
844     }
845 
846 #if 0
847     // open low-level device
848     int err = hci_stack.hci_transport->open(hci_stack.config);
849     if (err){
850         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
851         if (hci_stack.control && hci_stack.control->off){
852             (*hci_stack.control->off)(hci_stack.config);
853         }
854         hci_emit_hci_open_failed();
855         return err;
856     }
857 #endif
858 
859     return 0;
860 }
861 
862 
863 int hci_power_control(HCI_POWER_MODE power_mode){
864 
865     log_info("hci_power_control: %u, current mode %u\n", power_mode, hci_stack.state);
866 
867     int err = 0;
868     switch (hci_stack.state){
869 
870         case HCI_STATE_OFF:
871             switch (power_mode){
872                 case HCI_POWER_ON:
873                     err = hci_power_control_on();
874                     if (err) return err;
875                     // set up state machine
876                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
877                     hci_stack.state = HCI_STATE_INITIALIZING;
878                     hci_stack.substate = 0;
879                     break;
880                 case HCI_POWER_OFF:
881                     // do nothing
882                     break;
883                 case HCI_POWER_SLEEP:
884                     // do nothing (with SLEEP == OFF)
885                     break;
886             }
887             break;
888 
889         case HCI_STATE_INITIALIZING:
890             switch (power_mode){
891                 case HCI_POWER_ON:
892                     // do nothing
893                     break;
894                 case HCI_POWER_OFF:
895                     // no connections yet, just turn it off
896                     hci_power_control_off();
897                     break;
898                 case HCI_POWER_SLEEP:
899                     // no connections yet, just turn it off
900                     hci_power_control_sleep();
901                     break;
902             }
903             break;
904 
905         case HCI_STATE_WORKING:
906             switch (power_mode){
907                 case HCI_POWER_ON:
908                     // do nothing
909                     break;
910                 case HCI_POWER_OFF:
911                     // see hci_run
912                     hci_stack.state = HCI_STATE_HALTING;
913                     break;
914                 case HCI_POWER_SLEEP:
915                     // see hci_run
916                     hci_stack.state = HCI_STATE_FALLING_ASLEEP;
917                     hci_stack.substate = 0;
918                     break;
919             }
920             break;
921 
922         case HCI_STATE_HALTING:
923             switch (power_mode){
924                 case HCI_POWER_ON:
925                     // set up state machine
926                     hci_stack.state = HCI_STATE_INITIALIZING;
927                     hci_stack.substate = 0;
928                     break;
929                 case HCI_POWER_OFF:
930                     // do nothing
931                     break;
932                 case HCI_POWER_SLEEP:
933                     // see hci_run
934                     hci_stack.state = HCI_STATE_FALLING_ASLEEP;
935                     hci_stack.substate = 0;
936                     break;
937             }
938             break;
939 
940         case HCI_STATE_FALLING_ASLEEP:
941             switch (power_mode){
942                 case HCI_POWER_ON:
943 
944 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
945                     // nothing to do, if H4 supports power management
946                     if (bt_control_iphone_power_management_enabled()){
947                         hci_stack.state = HCI_STATE_INITIALIZING;
948                         hci_stack.substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
949                         break;
950                     }
951 #endif
952                     // set up state machine
953                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
954                     hci_stack.state = HCI_STATE_INITIALIZING;
955                     hci_stack.substate = 0;
956                     break;
957                 case HCI_POWER_OFF:
958                     // see hci_run
959                     hci_stack.state = HCI_STATE_HALTING;
960                     break;
961                 case HCI_POWER_SLEEP:
962                     // do nothing
963                     break;
964             }
965             break;
966 
967         case HCI_STATE_SLEEPING:
968             switch (power_mode){
969                 case HCI_POWER_ON:
970 
971 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
972                     // nothing to do, if H4 supports power management
973                     if (bt_control_iphone_power_management_enabled()){
974                         hci_stack.state = HCI_STATE_INITIALIZING;
975                         hci_stack.substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
976                         hci_update_scan_enable();
977                         break;
978                     }
979 #endif
980                     err = hci_power_control_wake();
981                     if (err) return err;
982                     // set up state machine
983                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
984                     hci_stack.state = HCI_STATE_INITIALIZING;
985                     hci_stack.substate = 0;
986                     break;
987                 case HCI_POWER_OFF:
988                     hci_stack.state = HCI_STATE_HALTING;
989                     break;
990                 case HCI_POWER_SLEEP:
991                     // do nothing
992                     break;
993             }
994             break;
995     }
996 
997     // create internal event
998 	hci_emit_state();
999 
1000 	// trigger next/first action
1001 	hci_run();
1002 
1003     return 0;
1004 }
1005 
1006 static void hci_update_scan_enable(void){
1007     // 2 = page scan, 1 = inq scan
1008     hci_stack.new_scan_enable_value  = hci_stack.connectable << 1 | hci_stack.discoverable;
1009     hci_run();
1010 }
1011 
1012 void hci_discoverable_control(uint8_t enable){
1013     if (enable) enable = 1; // normalize argument
1014 
1015     if (hci_stack.discoverable == enable){
1016         hci_emit_discoverable_enabled(hci_stack.discoverable);
1017         return;
1018     }
1019 
1020     hci_stack.discoverable = enable;
1021     hci_update_scan_enable();
1022 }
1023 
1024 void hci_connectable_control(uint8_t enable){
1025     if (enable) enable = 1; // normalize argument
1026 
1027     // don't emit event
1028     if (hci_stack.connectable == enable) return;
1029 
1030     hci_stack.connectable = enable;
1031     hci_update_scan_enable();
1032 }
1033 
1034 void hci_run(){
1035 
1036     hci_connection_t * connection;
1037     linked_item_t * it;
1038 
1039     if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1040 
1041     // global/non-connection oriented commands
1042 
1043     // decline incoming connections
1044     if (hci_stack.decline_reason){
1045         uint8_t reason = hci_stack.decline_reason;
1046         hci_stack.decline_reason = 0;
1047         hci_send_cmd(&hci_reject_connection_request, hci_stack.decline_addr, reason);
1048     }
1049 
1050     if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1051 
1052     // send scan enable
1053     if (hci_stack.state == HCI_STATE_WORKING && hci_stack.new_scan_enable_value != 0xff){
1054         hci_send_cmd(&hci_write_scan_enable, hci_stack.new_scan_enable_value);
1055         hci_stack.new_scan_enable_value = 0xff;
1056     }
1057 
1058     // send pending HCI commands
1059     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
1060 
1061         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1062 
1063         connection = (hci_connection_t *) it;
1064 
1065         if (connection->state == RECEIVED_CONNECTION_REQUEST){
1066             log_info("sending hci_accept_connection_request\n");
1067             hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1068             connection->state = ACCEPTED_CONNECTION_REQUEST;
1069         }
1070 
1071         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1072 
1073         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1074             link_key_t link_key;
1075             log_info("responding to link key request\n");
1076             if ( hci_stack.remote_device_db->get_link_key( &connection->address, &link_key)){
1077                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1078             } else {
1079                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1080             }
1081             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1082         }
1083     }
1084 
1085     if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1086 
1087     switch (hci_stack.state){
1088         case HCI_STATE_INITIALIZING:
1089             // log_info("hci_init: substate %u\n", hci_stack.substate);
1090             if (hci_stack.substate % 2) {
1091                 // odd: waiting for command completion
1092                 return;
1093             }
1094             switch (hci_stack.substate >> 1){
1095                 case 0: // RESET
1096                     hci_send_cmd(&hci_reset);
1097                     if (hci_stack.config == 0 || ((hci_uart_config_t *)hci_stack.config)->baudrate_main == 0){
1098                         // skip baud change
1099                         hci_stack.substate = 4; // >> 1 = 2
1100                     }
1101                     break;
1102                 case 1: // SEND BAUD CHANGE
1103                     hci_stack.control->baudrate_cmd(hci_stack.config, ((hci_uart_config_t *)hci_stack.config)->baudrate_main, hci_stack.hci_packet_buffer);
1104                     hci_send_cmd_packet(hci_stack.hci_packet_buffer, 3 + hci_stack.hci_packet_buffer[2]);
1105                     break;
1106                 case 2: // LOCAL BAUD CHANGE
1107                     hci_stack.hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack.config)->baudrate_main);
1108                     hci_stack.substate += 2;
1109                     // break missing here for fall through
1110 
1111                 case 3:
1112                     // custom initialization
1113                     if (hci_stack.control && hci_stack.control->next_cmd){
1114                         int valid_cmd = (*hci_stack.control->next_cmd)(hci_stack.config, hci_stack.hci_packet_buffer);
1115                         if (valid_cmd){
1116                             int size = 3 + hci_stack.hci_packet_buffer[2];
1117                             hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack.hci_packet_buffer, size);
1118                             hci_stack.substate = 4; // more init commands
1119                             break;
1120                         }
1121                         log_info("hci_run: init script done\n\r");
1122                     }
1123                     // otherwise continue
1124 					hci_send_cmd(&hci_read_bd_addr);
1125 					break;
1126 				case 4:
1127 					hci_send_cmd(&hci_read_buffer_size);
1128 					break;
1129                 case 5:
1130                     // ca. 15 sec
1131                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
1132                     break;
1133                 case 6:
1134                     hci_send_cmd(&hci_read_local_supported_features);
1135                     break;
1136                 case 7:
1137                     hci_send_cmd(&hci_write_class_of_device, hci_stack.class_of_device);
1138                     break;
1139                 case 8:
1140                     if (hci_stack.local_name){
1141                         hci_send_cmd(&hci_write_local_name, hci_stack.local_name);
1142                     } else {
1143                         char hostname[30];
1144 #ifdef EMBEDDED
1145                         // BTstack-11:22:33:44:55:66
1146                         strcpy(hostname, "BTstack ");
1147                         strcat(hostname, bd_addr_to_str(hci_stack.local_bd_addr));
1148                         printf("---> Name %s\n", hostname);
1149 #else
1150                         // hostname for POSIX systems
1151                         gethostname(hostname, 30);
1152                         hostname[29] = '\0';
1153 #endif
1154                         hci_send_cmd(&hci_write_local_name, hostname);
1155                     }
1156                     break;
1157                 case 9:
1158                     hci_send_cmd(&hci_set_event_mask,0xffffffff, 0xFFFFFFFF); ///0x1DFFFFFF
1159                     break;
1160                 case 10:
1161 					hci_send_cmd(&hci_write_scan_enable, (hci_stack.connectable << 1) | hci_stack.discoverable); // page scan
1162 					break;
1163                 case 11:
1164                     // done.
1165                     hci_stack.state = HCI_STATE_WORKING;
1166                     hci_emit_state();
1167                     break;
1168                 default:
1169                     break;
1170             }
1171             hci_stack.substate++;
1172             break;
1173 
1174         case HCI_STATE_HALTING:
1175 
1176             log_info("HCI_STATE_HALTING\n");
1177             // close all open connections
1178             connection =  (hci_connection_t *) hci_stack.connections;
1179             if (connection){
1180 
1181                 // send disconnect
1182                 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1183 
1184                 log_info("HCI_STATE_HALTING, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1185                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1186 
1187                 // send disconnected event right away - causes higher layer connections to get closed, too.
1188                 hci_shutdown_connection(connection);
1189                 return;
1190             }
1191             log_info("HCI_STATE_HALTING, calling off\n");
1192 
1193             // switch mode
1194             hci_power_control_off();
1195 
1196             log_info("HCI_STATE_HALTING, emitting state\n");
1197             hci_emit_state();
1198             log_info("HCI_STATE_HALTING, done\n");
1199             break;
1200 
1201         case HCI_STATE_FALLING_ASLEEP:
1202             switch(hci_stack.substate) {
1203                 case 0:
1204                     log_info("HCI_STATE_FALLING_ASLEEP\n");
1205                     // close all open connections
1206                     connection =  (hci_connection_t *) hci_stack.connections;
1207 
1208 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1209                     // don't close connections, if H4 supports power management
1210                     if (bt_control_iphone_power_management_enabled()){
1211                         connection = NULL;
1212                     }
1213 #endif
1214                     if (connection){
1215 
1216                         // send disconnect
1217                         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1218 
1219                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1220                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1221 
1222                         // send disconnected event right away - causes higher layer connections to get closed, too.
1223                         hci_shutdown_connection(connection);
1224                         return;
1225                     }
1226 
1227                     // disable page and inquiry scan
1228                     if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1229 
1230                     log_info("HCI_STATE_HALTING, disabling inq cans\n");
1231                     hci_send_cmd(&hci_write_scan_enable, hci_stack.connectable << 1); // drop inquiry scan but keep page scan
1232 
1233                     // continue in next sub state
1234                     hci_stack.substate++;
1235                     break;
1236                 case 1:
1237                     // wait for command complete "hci_write_scan_enable" in event_handler();
1238                     break;
1239                 case 2:
1240                     log_info("HCI_STATE_HALTING, calling sleep\n");
1241 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1242                     // don't actually go to sleep, if H4 supports power management
1243                     if (bt_control_iphone_power_management_enabled()){
1244                         // SLEEP MODE reached
1245                         hci_stack.state = HCI_STATE_SLEEPING;
1246                         hci_emit_state();
1247                         break;
1248                     }
1249 #endif
1250                     // switch mode
1251                     hci_power_control_sleep();  // changes hci_stack.state to SLEEP
1252                     hci_emit_state();
1253                     break;
1254 
1255                 default:
1256                     break;
1257             }
1258             break;
1259 
1260         default:
1261             break;
1262     }
1263 }
1264 
1265 int hci_send_cmd_packet(uint8_t *packet, int size){
1266     bd_addr_t addr;
1267     hci_connection_t * conn;
1268     // house-keeping
1269 
1270     // create_connection?
1271     if (IS_COMMAND(packet, hci_create_connection)){
1272         bt_flip_addr(addr, &packet[3]);
1273         log_info("Create_connection to %s\n", bd_addr_to_str(addr));
1274         conn = connection_for_address(addr);
1275         if (conn) {
1276             // if connection exists
1277             if (conn->state == OPEN) {
1278                 // and OPEN, emit connection complete command
1279                 hci_emit_connection_complete(conn, 0);
1280             }
1281             //    otherwise, just ignore as it is already in the open process
1282             return 0; // don't sent packet to controller
1283 
1284         }
1285         // create connection struct and register, state = SENT_CREATE_CONNECTION
1286         conn = create_connection_for_addr(addr);
1287         if (!conn){
1288             // notify client that alloc failed
1289             hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
1290             return 0; // don't sent packet to controller
1291         }
1292         conn->state = SENT_CREATE_CONNECTION;
1293     }
1294 
1295     if (IS_COMMAND(packet, hci_link_key_request_reply)){
1296         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
1297     }
1298     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
1299         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
1300     }
1301     if (IS_COMMAND(packet, hci_pin_code_request_reply)){
1302         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_REPLY);
1303     }
1304     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)){
1305         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_NEGATIVE_REPLY);
1306     }
1307 
1308     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
1309         if (hci_stack.remote_device_db){
1310             bt_flip_addr(addr, &packet[3]);
1311             hci_stack.remote_device_db->delete_link_key(&addr);
1312         }
1313     }
1314 
1315     hci_stack.num_cmd_packets--;
1316     return hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
1317 }
1318 
1319 /**
1320  * pre: numcmds >= 0 - it's allowed to send a command to the controller
1321  */
1322 int hci_send_cmd(const hci_cmd_t *cmd, ...){
1323     va_list argptr;
1324     va_start(argptr, cmd);
1325     uint16_t size = hci_create_cmd_internal(hci_stack.hci_packet_buffer, cmd, argptr);
1326     va_end(argptr);
1327     return hci_send_cmd_packet(hci_stack.hci_packet_buffer, size);
1328 }
1329 
1330 // Create various non-HCI events.
1331 // TODO: generalize, use table similar to hci_create_command
1332 
1333 void hci_emit_state(){
1334     log_info("BTSTACK_EVENT_STATE %u", hci_stack.state);
1335     uint8_t event[3];
1336     event[0] = BTSTACK_EVENT_STATE;
1337     event[1] = sizeof(event) - 2;
1338     event[2] = hci_stack.state;
1339     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1340     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1341 }
1342 
1343 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
1344     uint8_t event[13];
1345     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
1346     event[1] = sizeof(event) - 2;
1347     event[2] = status;
1348     bt_store_16(event, 3, conn->con_handle);
1349     bt_flip_addr(&event[5], conn->address);
1350     event[11] = 1; // ACL connection
1351     event[12] = 0; // encryption disabled
1352     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1353     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1354 }
1355 
1356 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
1357     uint8_t event[6];
1358     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
1359     event[1] = sizeof(event) - 2;
1360     event[2] = 0; // status = OK
1361     bt_store_16(event, 3, handle);
1362     event[5] = reason;
1363     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1364     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1365 }
1366 
1367 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
1368     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
1369     uint8_t event[4];
1370     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
1371     event[1] = sizeof(event) - 2;
1372     bt_store_16(event, 2, conn->con_handle);
1373     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1374     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1375 }
1376 
1377 void hci_emit_nr_connections_changed(){
1378     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
1379     uint8_t event[3];
1380     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
1381     event[1] = sizeof(event) - 2;
1382     event[2] = nr_hci_connections();
1383     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1384     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1385 }
1386 
1387 void hci_emit_hci_open_failed(){
1388     log_info("BTSTACK_EVENT_POWERON_FAILED");
1389     uint8_t event[2];
1390     event[0] = BTSTACK_EVENT_POWERON_FAILED;
1391     event[1] = sizeof(event) - 2;
1392     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1393     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1394 }
1395 
1396 #ifndef EMBEDDED
1397 void hci_emit_btstack_version() {
1398     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
1399     uint8_t event[6];
1400     event[0] = BTSTACK_EVENT_VERSION;
1401     event[1] = sizeof(event) - 2;
1402     event[2] = BTSTACK_MAJOR;
1403     event[3] = BTSTACK_MINOR;
1404     bt_store_16(event, 4, BTSTACK_REVISION);
1405     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1406     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1407 }
1408 #endif
1409 
1410 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
1411     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
1412     uint8_t event[3];
1413     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
1414     event[1] = sizeof(event) - 2;
1415     event[2] = enabled;
1416     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1417     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1418 }
1419 
1420 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
1421     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
1422     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
1423     event[1] = sizeof(event) - 2 - 1;
1424     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
1425     bt_flip_addr(&event[3], *addr);
1426     memcpy(&event[9], name, 248);
1427 
1428     event[9+248] = 0;   // assert \0 for log_info
1429     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
1430 
1431     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
1432     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
1433 }
1434 
1435 void hci_emit_discoverable_enabled(uint8_t enabled){
1436     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
1437     uint8_t event[3];
1438     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
1439     event[1] = sizeof(event) - 2;
1440     event[2] = enabled;
1441     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1442     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1443 }
1444