xref: /btstack/src/hci.c (revision c77e88389f20390e6cf1974c314856f02ef7648f)
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 #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 
74 // the STACK is here
75 static hci_stack_t       hci_stack;
76 
77 /**
78  * get connection for a given handle
79  *
80  * @return connection OR NULL, if not found
81  */
82 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
83     linked_item_t *it;
84     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
85         if ( ((hci_connection_t *) it)->con_handle == con_handle){
86             return (hci_connection_t *) it;
87         }
88     }
89     return NULL;
90 }
91 
92 static void hci_connection_timeout_handler(timer_source_t *timer){
93     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
94 #ifdef HAVE_TIME
95     struct timeval tv;
96     gettimeofday(&tv, NULL);
97     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
98         // connections might be timed out
99         hci_emit_l2cap_check_timeout(connection);
100     }
101 #endif
102 #ifdef HAVE_TICK
103     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
104         // connections might be timed out
105         hci_emit_l2cap_check_timeout(connection);
106     }
107 #endif
108     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
109     run_loop_add_timer(timer);
110 }
111 
112 static void hci_connection_timestamp(hci_connection_t *connection){
113 #ifdef HAVE_TIME
114     gettimeofday(&connection->timestamp, NULL);
115 #endif
116 #ifdef HAVE_TICK
117     connection->timestamp = embedded_get_ticks();
118 #endif
119 }
120 
121 /**
122  * create connection for given address
123  *
124  * @return connection OR NULL, if no memory left
125  */
126 static hci_connection_t * create_connection_for_addr(bd_addr_t addr){
127     hci_connection_t * conn = (hci_connection_t *) btstack_memory_hci_connection_get();
128     if (!conn) return NULL;
129     BD_ADDR_COPY(conn->address, addr);
130     conn->con_handle = 0xffff;
131     conn->authentication_flags = AUTH_FLAGS_NONE;
132     conn->bonding_flags = 0;
133     linked_item_set_user(&conn->timeout.item, conn);
134     conn->timeout.process = hci_connection_timeout_handler;
135     hci_connection_timestamp(conn);
136     conn->acl_recombination_length = 0;
137     conn->acl_recombination_pos = 0;
138     conn->num_acl_packets_sent = 0;
139     linked_list_add(&hci_stack.connections, (linked_item_t *) conn);
140     return conn;
141 }
142 
143 /**
144  * get connection for given address
145  *
146  * @return connection OR NULL, if not found
147  */
148 static hci_connection_t * connection_for_address(bd_addr_t address){
149     linked_item_t *it;
150     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
151         if ( ! BD_ADDR_CMP( ((hci_connection_t *) it)->address, address) ){
152             return (hci_connection_t *) it;
153         }
154     }
155     return NULL;
156 }
157 
158 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
159     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
160 }
161 
162 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
163     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
164 }
165 
166 
167 /**
168  * add authentication flags and reset timer
169  */
170 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
171     bd_addr_t addr;
172     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
173     hci_connection_t * conn = connection_for_address(addr);
174     if (conn) {
175         connectionSetAuthenticationFlags(conn, flags);
176         hci_connection_timestamp(conn);
177     }
178 }
179 
180 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
181     hci_connection_t * conn = hci_connection_for_handle(handle);
182     if (!conn) return 0;
183     if (!conn->authentication_flags) return 0;
184     if (conn->authentication_flags & SENT_LINK_KEY_REPLY) return 0;
185     if (conn->authentication_flags & RECV_LINK_KEY_NOTIFICATION) return 0;
186     return 1;
187 }
188 
189 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
190     if (hci_stack.remote_device_db) {
191         hci_stack.remote_device_db->delete_link_key(addr);
192     }
193 }
194 
195 
196 /**
197  * count connections
198  */
199 static int nr_hci_connections(void){
200     int count = 0;
201     linked_item_t *it;
202     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next, count++);
203     return count;
204 }
205 
206 /**
207  * Dummy handler called by HCI
208  */
209 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
210 }
211 
212 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
213     hci_connection_t * connection = hci_connection_for_handle(handle);
214     if (!connection) {
215         log_error("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
216         return 0;
217     }
218     return connection->num_acl_packets_sent;
219 }
220 
221 uint8_t hci_number_free_acl_slots(){
222     uint8_t free_slots = hci_stack.total_num_acl_packets;
223     linked_item_t *it;
224     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
225         hci_connection_t * connection = (hci_connection_t *) it;
226         if (free_slots < connection->num_acl_packets_sent) {
227             log_error("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
228             return 0;
229         }
230         free_slots -= connection->num_acl_packets_sent;
231     }
232     return free_slots;
233 }
234 
235 int hci_can_send_packet_now(uint8_t packet_type){
236 
237     // check for async hci transport implementations
238     if (hci_stack.hci_transport->can_send_packet_now){
239         if (!hci_stack.hci_transport->can_send_packet_now(packet_type)){
240             return 0;
241         }
242     }
243 
244     // check regular Bluetooth flow control
245     switch (packet_type) {
246         case HCI_ACL_DATA_PACKET:
247             return hci_number_free_acl_slots();
248         case HCI_COMMAND_DATA_PACKET:
249             return hci_stack.num_cmd_packets;
250         default:
251             return 0;
252     }
253 }
254 
255 int hci_send_acl_packet(uint8_t *packet, int size){
256 
257     // check for free places on BT module
258     if (!hci_number_free_acl_slots()) return BTSTACK_ACL_BUFFERS_FULL;
259 
260     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
261     hci_connection_t *connection = hci_connection_for_handle( con_handle);
262     if (!connection) return 0;
263     hci_connection_timestamp(connection);
264 
265     // count packet
266     connection->num_acl_packets_sent++;
267     // log_info("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
268 
269     // send packet
270     int err = hci_stack.hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
271 
272     return err;
273 }
274 
275 static void acl_handler(uint8_t *packet, int size){
276 
277     // log_info("acl_handler: size %u", size);
278 
279     // get info
280     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
281     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
282     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
283     uint16_t acl_length         = READ_ACL_LENGTH(packet);
284 
285     // ignore non-registered handle
286     if (!conn){
287         log_error( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
288         return;
289     }
290 
291     // assert packet is complete
292     if (acl_length + 4 != size){
293         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
294         return;
295     }
296 
297     // update idle timestamp
298     hci_connection_timestamp(conn);
299 
300     // handle different packet types
301     switch (acl_flags & 0x03) {
302 
303         case 0x01: // continuation fragment
304 
305             // sanity check
306             if (conn->acl_recombination_pos == 0) {
307                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
308                 return;
309             }
310 
311             // append fragment payload (header already stored)
312             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
313             conn->acl_recombination_pos += acl_length;
314 
315             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n", acl_length,
316             //        conn->acl_recombination_pos, conn->acl_recombination_length);
317 
318             // forward complete L2CAP packet if complete.
319             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
320 
321                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
322                 // reset recombination buffer
323                 conn->acl_recombination_length = 0;
324                 conn->acl_recombination_pos = 0;
325             }
326             break;
327 
328         case 0x02: { // first fragment
329 
330             // sanity check
331             if (conn->acl_recombination_pos) {
332                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
333                 return;
334             }
335 
336             // peek into L2CAP packet!
337             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
338 
339             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
340 
341             // compare fragment size to L2CAP packet size
342             if (acl_length >= l2cap_length + 4){
343 
344                 // forward fragment as L2CAP packet
345                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
346 
347             } else {
348                 // store first fragment and tweak acl length for complete package
349                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
350                 conn->acl_recombination_pos    = acl_length + 4;
351                 conn->acl_recombination_length = l2cap_length;
352                 bt_store_16(conn->acl_recombination_buffer, 2, l2cap_length +4);
353             }
354             break;
355 
356         }
357         default:
358             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
359             return;
360     }
361 
362     // execute main loop
363     hci_run();
364 }
365 
366 static void hci_shutdown_connection(hci_connection_t *conn){
367     log_info("Connection closed: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
368 
369     // cancel all l2cap connections
370     hci_emit_disconnection_complete(conn->con_handle, 0x16);    // terminated by local host
371 
372     run_loop_remove_timer(&conn->timeout);
373 
374     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
375     btstack_memory_hci_connection_free( conn );
376 
377     // now it's gone
378     hci_emit_nr_connections_changed();
379 }
380 
381 static const uint16_t packet_type_sizes[] = {
382     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
383     HCI_ACL_DH1_SIZE, 0, 0, 0,
384     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
385     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
386 };
387 static const uint8_t  packet_type_feature_requirement_bit[] = {
388      0, // 3 slot packets
389      1, // 5 slot packets
390     25, // EDR 2 mpbs
391     26, // EDR 3 mbps
392     39, // 3 slot EDR packts
393     40, // 5 slot EDR packet
394 };
395 static const uint16_t packet_type_feature_packet_mask[] = {
396     0x0f00, // 3 slot packets
397     0xf000, // 5 slot packets
398     0x1102, // EDR 2 mpbs
399     0x2204, // EDR 3 mbps
400     0x0300, // 3 slot EDR packts
401     0x3000, // 5 slot EDR packet
402 };
403 
404 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
405     // enable packet types based on size
406     uint16_t packet_types = 0;
407     int i;
408     for (i=0;i<16;i++){
409         if (packet_type_sizes[i] == 0) continue;
410         if (packet_type_sizes[i] <= buffer_size){
411             packet_types |= 1 << i;
412         }
413     }
414     // disable packet types due to missing local supported features
415     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
416         int bit_idx = packet_type_feature_requirement_bit[i];
417         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
418         if (feature_set) continue;
419         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
420         packet_types &= ~packet_type_feature_packet_mask[i];
421     }
422     // flip bits for "may not be used"
423     packet_types ^= 0x3306;
424     return packet_types;
425 }
426 
427 uint16_t hci_usable_acl_packet_types(void){
428     return hci_stack.packet_types;
429 }
430 
431 uint8_t* hci_get_outgoing_acl_packet_buffer(void){
432     // hci packet buffer is >= acl data packet length
433     return hci_stack.hci_packet_buffer;
434 }
435 
436 uint16_t hci_max_acl_data_packet_length(void){
437     return hci_stack.acl_data_packet_length;
438 }
439 
440 int hci_ssp_supported(void){
441     // No 51, byte 6, bit 3
442     return (hci_stack.local_supported_features[6] & (1 << 3)) != 0;
443 }
444 
445 int hci_classic_supported(void){
446     // No 37, byte 4, bit 5, = No BR/EDR Support
447     return (hci_stack.local_supported_features[4] & (1 << 5)) == 0;
448 }
449 
450 int hci_le_supported(void){
451     // No 37, byte 4, bit 6 = LE Supported (Controller)
452 #ifdef HAVE_BLE
453     return (hci_stack.local_supported_features[4] & (1 << 6)) != 0;
454 #else
455     return 0;
456 #endif
457 }
458 
459 // get addr type and address used in advertisement packets
460 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
461     *addr_type = hci_stack.adv_addr_type;
462     if (hci_stack.adv_addr_type){
463         memcpy(addr, hci_stack.adv_address, 6);
464     } else {
465         memcpy(addr, hci_stack.local_bd_addr, 6);
466     }
467 }
468 
469 // avoid huge local variables
470 #ifndef EMBEDDED
471 static device_name_t device_name;
472 #endif
473 static void event_handler(uint8_t *packet, int size){
474 
475     uint16_t event_length = packet[1];
476 
477     // assert packet is complete
478     if (size != event_length + 2){
479         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
480         return;
481     }
482 
483     bd_addr_t addr;
484     uint8_t link_type;
485     hci_con_handle_t handle;
486     hci_connection_t * conn;
487     int i;
488 
489     // printf("HCI:EVENT:%02x\n", packet[0]);
490 
491     switch (packet[0]) {
492 
493         case HCI_EVENT_COMMAND_COMPLETE:
494             // get num cmd packets
495             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u\n", hci_stack.num_cmd_packets, packet[2]);
496             hci_stack.num_cmd_packets = packet[2];
497 
498             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
499                 // from offset 5
500                 // status
501                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
502                 hci_stack.acl_data_packet_length = READ_BT_16(packet, 6);
503                 // ignore: SCO data packet len (8)
504                 hci_stack.total_num_acl_packets  = packet[9];
505                 // ignore: total num SCO packets
506                 if (hci_stack.state == HCI_STATE_INITIALIZING){
507                     // determine usable ACL payload size
508                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack.acl_data_packet_length){
509                         hci_stack.acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
510                     }
511                     log_info("hci_read_buffer_size: used size %u, count %u\n",
512                              hci_stack.acl_data_packet_length, hci_stack.total_num_acl_packets);
513                 }
514             }
515 #ifdef HAVE_BLE
516             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
517                 hci_stack.le_data_packet_length = READ_BT_16(packet, 6);
518                 hci_stack.total_num_le_packets  = packet[8];
519                 log_info("hci_le_read_buffer_size: size %u, count %u\n", hci_stack.le_data_packet_length, hci_stack.total_num_le_packets);
520             }
521 #endif
522             // Dump local address
523             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
524                 bt_flip_addr(hci_stack.local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
525                 log_info("Local Address, Status: 0x%02x: Addr: %s\n",
526                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack.local_bd_addr));
527             }
528             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
529                 hci_emit_discoverable_enabled(hci_stack.discoverable);
530             }
531             // Note: HCI init checks
532             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
533                 memcpy(hci_stack.local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
534                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
535                     hci_stack.local_supported_features[0], hci_stack.local_supported_features[1],
536                     hci_stack.local_supported_features[2], hci_stack.local_supported_features[3],
537                     hci_stack.local_supported_features[4], hci_stack.local_supported_features[5],
538                     hci_stack.local_supported_features[6], hci_stack.local_supported_features[7]);
539 
540                 // determine usable ACL packet types based buffer size and supported features
541                 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]);
542                 log_info("packet types %04x", hci_stack.packet_types);
543 
544                 // Classic/LE
545                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
546             }
547             break;
548 
549         case HCI_EVENT_COMMAND_STATUS:
550             // get num cmd packets
551             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u\n", hci_stack.num_cmd_packets, packet[3]);
552             hci_stack.num_cmd_packets = packet[3];
553             break;
554 
555         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
556             for (i=0; i<packet[2];i++){
557                 handle = READ_BT_16(packet, 3 + 2*i);
558                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
559                 conn = hci_connection_for_handle(handle);
560                 if (!conn){
561                     log_error("hci_number_completed_packet lists unused con handle %u\n", handle);
562                     continue;
563                 }
564                 conn->num_acl_packets_sent -= num_packets;
565                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
566             }
567             break;
568 
569         case HCI_EVENT_CONNECTION_REQUEST:
570             bt_flip_addr(addr, &packet[2]);
571             // TODO: eval COD 8-10
572             link_type = packet[11];
573             log_info("Connection_incoming: %s, type %u\n", bd_addr_to_str(addr), link_type);
574             if (link_type == 1) { // ACL
575                 conn = connection_for_address(addr);
576                 if (!conn) {
577                     conn = create_connection_for_addr(addr);
578                 }
579                 if (!conn) {
580                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
581                     hci_stack.decline_reason = 0x0d;
582                     BD_ADDR_COPY(hci_stack.decline_addr, addr);
583                     break;
584                 }
585                 conn->state = RECEIVED_CONNECTION_REQUEST;
586                 hci_run();
587             } else {
588                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
589                 hci_stack.decline_reason = 0x0a;
590                 BD_ADDR_COPY(hci_stack.decline_addr, addr);
591             }
592             break;
593 
594         case HCI_EVENT_CONNECTION_COMPLETE:
595             // Connection management
596             bt_flip_addr(addr, &packet[5]);
597             log_info("Connection_complete (status=%u) %s\n", packet[2], bd_addr_to_str(addr));
598             conn = connection_for_address(addr);
599             if (conn) {
600                 if (!packet[2]){
601                     conn->state = OPEN;
602                     conn->con_handle = READ_BT_16(packet, 3);
603                     conn->bonding_flags = BONDING_REQUEST_REMOTE_FEATURES;
604 
605                     // restart timer
606                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
607                     run_loop_add_timer(&conn->timeout);
608 
609                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
610 
611                     hci_emit_nr_connections_changed();
612                 } else {
613                     // connection failed, remove entry
614                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
615                     btstack_memory_hci_connection_free( conn );
616 
617                     // if authentication error, also delete link key
618                     if (packet[2] == 0x05) {
619                         hci_drop_link_key_for_bd_addr(&addr);
620                     }
621                 }
622             }
623             break;
624 
625         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
626             handle = READ_BT_16(packet, 3);
627             conn = hci_connection_for_handle(handle);
628             if (!conn) break;
629             if (!packet[2]){
630                 uint8_t * features = &packet[5];
631                 if (features[6] & (1 << 3)){
632                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
633                 }
634             }
635             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
636             break;
637 
638         case HCI_EVENT_LINK_KEY_REQUEST:
639             log_info("HCI_EVENT_LINK_KEY_REQUEST\n");
640             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
641             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
642             if (hci_stack.bondable && !hci_stack.remote_device_db) break;
643             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
644             hci_run();
645             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
646             return;
647 
648         case HCI_EVENT_LINK_KEY_NOTIFICATION:
649             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_NOTIFICATION);
650             if (!hci_stack.remote_device_db) break;
651             bt_flip_addr(addr, &packet[2]);
652             // @TODO determine link key type
653             hci_stack.remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], LINK_KEY_TYPE_UNAUTHENTICATED);
654             // still forward event to allow dismiss of pairing dialog
655             break;
656 
657         case HCI_EVENT_PIN_CODE_REQUEST:
658             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_PIN_CODE_REQUEST);
659             // non-bondable mode: pin code negative reply will be sent
660             if (!hci_stack.bondable){
661                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_PIN_CODE_REQUEST);
662                 hci_run();
663                 return;
664             }
665             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
666             if (!hci_stack.remote_device_db) break;
667             bt_flip_addr(addr, &packet[2]);
668             hci_stack.remote_device_db->delete_link_key(&addr);
669             break;
670 
671         case HCI_EVENT_IO_CAPABILITY_REQUEST:
672             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
673             if (!hci_stack.bondable || hci_stack.ssp_io_capability == SSP_IO_CAPABILITY_UNKNOWN) break;
674             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
675             break;
676 
677         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
678             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_USER_CONFIRM_REQUEST);
679             if (!hci_stack.ssp_auto_accept) break;
680             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
681             break;
682 
683         case HCI_EVENT_USER_PASSKEY_REQUEST:
684             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_USER_PASSKEY_REQUEST);
685             if (!hci_stack.ssp_auto_accept) break;
686             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
687             break;
688 
689         case HCI_EVENT_ENCRYPTION_CHANGE:
690             if (packet[2]) break;   // error status
691             handle = READ_BT_16(packet, 3);
692             conn = hci_connection_for_handle(handle);
693             if (!conn) break;
694             if (packet[5]){
695                 conn->authentication_flags |= CONNECTION_ENCRYPTED;
696                 // @TODO set authentication depending on pairing process
697             } else {
698                 conn->authentication_flags &= ~(CONNECTION_ENCRYPTED | CONNECTION_AUTHENTICATED);
699             }
700             break;
701 
702 #ifndef EMBEDDED
703         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
704             if (!hci_stack.remote_device_db) break;
705             if (packet[2]) break; // status not ok
706             bt_flip_addr(addr, &packet[3]);
707             // fix for invalid remote names - terminate on 0xff
708             for (i=0; i<248;i++){
709                 if (packet[9+i] == 0xff){
710                     packet[9+i] = 0;
711                     break;
712                 }
713             }
714             memset(&device_name, 0, sizeof(device_name_t));
715             strncpy((char*) device_name, (char*) &packet[9], 248);
716             hci_stack.remote_device_db->put_name(&addr, &device_name);
717             break;
718 
719         case HCI_EVENT_INQUIRY_RESULT:
720         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
721             if (!hci_stack.remote_device_db) break;
722             // first send inq result packet
723             hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
724             // then send cached remote names
725             for (i=0; i<packet[2];i++){
726                 bt_flip_addr(addr, &packet[3+i*6]);
727                 if (hci_stack.remote_device_db->get_name(&addr, &device_name)){
728                     hci_emit_remote_name_cached(&addr, &device_name);
729                 }
730             }
731             return;
732 #endif
733 
734         case HCI_EVENT_DISCONNECTION_COMPLETE:
735             if (!packet[2]){
736                 handle = READ_BT_16(packet, 3);
737                 hci_connection_t * conn = hci_connection_for_handle(handle);
738                 if (conn) {
739                     hci_shutdown_connection(conn);
740                 }
741             }
742             break;
743 
744         case HCI_EVENT_HARDWARE_ERROR:
745             if(hci_stack.control && hci_stack.control->hw_error){
746                 (*hci_stack.control->hw_error)();
747             }
748             break;
749 
750 #ifdef HAVE_BLE
751         case HCI_EVENT_LE_META:
752             switch (packet[2]) {
753                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
754                     // Connection management
755                     bt_flip_addr(addr, &packet[8]);
756                     log_info("LE Connection_complete (status=%u) %s\n", packet[3], bd_addr_to_str(addr));
757                     // LE connections are auto-accepted, so just create a connection if there isn't one already
758                     conn = connection_for_address(addr);
759                     if (packet[3]){
760                         if (conn){
761                             // outgoing connection failed, remove entry
762                             linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
763                             btstack_memory_hci_connection_free( conn );
764 
765                         }
766                         // if authentication error, also delete link key
767                         if (packet[3] == 0x05) {
768                             hci_drop_link_key_for_bd_addr(&addr);
769                         }
770                         break;
771                     }
772                     if (!conn){
773                         conn = create_connection_for_addr(addr);
774                     }
775                     if (!conn){
776                         // no memory
777                         break;
778                     }
779 
780                     conn->state = OPEN;
781                     conn->con_handle = READ_BT_16(packet, 4);
782 
783                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
784 
785                     // restart timer
786                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
787                     // run_loop_add_timer(&conn->timeout);
788 
789                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
790 
791                     hci_emit_nr_connections_changed();
792                     break;
793 
794             // printf("LE buffer size: %u, count %u\n", READ_BT_16(packet,6), packet[8]);
795 
796                 default:
797                     break;
798             }
799             break;
800 #endif
801 
802         default:
803             break;
804     }
805 
806     // handle BT initialization
807     if (hci_stack.state == HCI_STATE_INITIALIZING){
808         if (hci_stack.substate % 2){
809             // odd: waiting for event
810             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
811                 // wait for explicit COMMAND COMPLETE on RESET
812                 if (hci_stack.substate > 1 || COMMAND_COMPLETE_EVENT(packet, hci_reset)) {
813                     hci_stack.substate++;
814                 }
815             }
816         }
817     }
818 
819     // help with BT sleep
820     if (hci_stack.state == HCI_STATE_FALLING_ASLEEP
821         && hci_stack.substate == 1
822         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
823         hci_stack.substate++;
824     }
825 
826     hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
827 
828 	// execute main loop
829 	hci_run();
830 }
831 
832 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
833     switch (packet_type) {
834         case HCI_EVENT_PACKET:
835             event_handler(packet, size);
836             break;
837         case HCI_ACL_DATA_PACKET:
838             acl_handler(packet, size);
839             break;
840         default:
841             break;
842     }
843 }
844 
845 /** Register HCI packet handlers */
846 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
847     hci_stack.packet_handler = handler;
848 }
849 
850 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
851 
852     // reference to use transport layer implementation
853     hci_stack.hci_transport = transport;
854 
855     // references to used control implementation
856     hci_stack.control = control;
857 
858     // reference to used config
859     hci_stack.config = config;
860 
861     // no connections yet
862     hci_stack.connections = NULL;
863     hci_stack.discoverable = 0;
864     hci_stack.connectable = 0;
865     hci_stack.bondable = 1;
866 
867     // no pending cmds
868     hci_stack.decline_reason = 0;
869     hci_stack.new_scan_enable_value = 0xff;
870 
871     // higher level handler
872     hci_stack.packet_handler = dummy_handler;
873 
874     // store and open remote device db
875     hci_stack.remote_device_db = remote_device_db;
876     if (hci_stack.remote_device_db) {
877         hci_stack.remote_device_db->open();
878     }
879 
880     // max acl payload size defined in config.h
881     hci_stack.acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
882 
883     // register packet handlers with transport
884     transport->register_packet_handler(&packet_handler);
885 
886     hci_stack.state = HCI_STATE_OFF;
887 
888     // class of device
889     hci_stack.class_of_device = 0x007a020c; // Smartphone
890 
891     // Secure Simple Pairing default: enable, no I/O capabilities, auto accept
892     hci_stack.ssp_enable = 1;
893     hci_stack.ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
894     hci_stack.ssp_authentication_requirement = 0;
895     hci_stack.ssp_auto_accept = 1;
896 
897     // LE
898     hci_stack.adv_addr_type = 0;
899     memset(hci_stack.adv_address, 0, 6);
900 }
901 
902 void hci_close(){
903     // close remote device db
904     if (hci_stack.remote_device_db) {
905         hci_stack.remote_device_db->close();
906     }
907     while (hci_stack.connections) {
908         hci_shutdown_connection((hci_connection_t *) hci_stack.connections);
909 }
910     hci_power_control(HCI_POWER_OFF);
911 }
912 
913 // State-Module-Driver overview
914 // state                    module  low-level
915 // HCI_STATE_OFF             off      close
916 // HCI_STATE_INITIALIZING,   on       open
917 // HCI_STATE_WORKING,        on       open
918 // HCI_STATE_HALTING,        on       open
919 // HCI_STATE_SLEEPING,    off/sleep   close
920 // HCI_STATE_FALLING_ASLEEP  on       open
921 
922 static int hci_power_control_on(void){
923 
924     // power on
925     int err = 0;
926     if (hci_stack.control && hci_stack.control->on){
927         err = (*hci_stack.control->on)(hci_stack.config);
928     }
929     if (err){
930         log_error( "POWER_ON failed\n");
931         hci_emit_hci_open_failed();
932         return err;
933     }
934 
935     // open low-level device
936     err = hci_stack.hci_transport->open(hci_stack.config);
937     if (err){
938         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
939         if (hci_stack.control && hci_stack.control->off){
940             (*hci_stack.control->off)(hci_stack.config);
941         }
942         hci_emit_hci_open_failed();
943         return err;
944     }
945     return 0;
946 }
947 
948 static void hci_power_control_off(void){
949 
950     log_info("hci_power_control_off\n");
951 
952     // close low-level device
953     hci_stack.hci_transport->close(hci_stack.config);
954 
955     log_info("hci_power_control_off - hci_transport closed\n");
956 
957     // power off
958     if (hci_stack.control && hci_stack.control->off){
959         (*hci_stack.control->off)(hci_stack.config);
960     }
961 
962     log_info("hci_power_control_off - control closed\n");
963 
964     hci_stack.state = HCI_STATE_OFF;
965 }
966 
967 static void hci_power_control_sleep(void){
968 
969     log_info("hci_power_control_sleep\n");
970 
971 #if 0
972     // don't close serial port during sleep
973 
974     // close low-level device
975     hci_stack.hci_transport->close(hci_stack.config);
976 #endif
977 
978     // sleep mode
979     if (hci_stack.control && hci_stack.control->sleep){
980         (*hci_stack.control->sleep)(hci_stack.config);
981     }
982 
983     hci_stack.state = HCI_STATE_SLEEPING;
984 }
985 
986 static int hci_power_control_wake(void){
987 
988     log_info("hci_power_control_wake\n");
989 
990     // wake on
991     if (hci_stack.control && hci_stack.control->wake){
992         (*hci_stack.control->wake)(hci_stack.config);
993     }
994 
995 #if 0
996     // open low-level device
997     int err = hci_stack.hci_transport->open(hci_stack.config);
998     if (err){
999         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
1000         if (hci_stack.control && hci_stack.control->off){
1001             (*hci_stack.control->off)(hci_stack.config);
1002         }
1003         hci_emit_hci_open_failed();
1004         return err;
1005     }
1006 #endif
1007 
1008     return 0;
1009 }
1010 
1011 
1012 int hci_power_control(HCI_POWER_MODE power_mode){
1013 
1014     log_info("hci_power_control: %u, current mode %u\n", power_mode, hci_stack.state);
1015 
1016     int err = 0;
1017     switch (hci_stack.state){
1018 
1019         case HCI_STATE_OFF:
1020             switch (power_mode){
1021                 case HCI_POWER_ON:
1022                     err = hci_power_control_on();
1023                     if (err) return err;
1024                     // set up state machine
1025                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
1026                     hci_stack.state = HCI_STATE_INITIALIZING;
1027                     hci_stack.substate = 0;
1028                     break;
1029                 case HCI_POWER_OFF:
1030                     // do nothing
1031                     break;
1032                 case HCI_POWER_SLEEP:
1033                     // do nothing (with SLEEP == OFF)
1034                     break;
1035             }
1036             break;
1037 
1038         case HCI_STATE_INITIALIZING:
1039             switch (power_mode){
1040                 case HCI_POWER_ON:
1041                     // do nothing
1042                     break;
1043                 case HCI_POWER_OFF:
1044                     // no connections yet, just turn it off
1045                     hci_power_control_off();
1046                     break;
1047                 case HCI_POWER_SLEEP:
1048                     // no connections yet, just turn it off
1049                     hci_power_control_sleep();
1050                     break;
1051             }
1052             break;
1053 
1054         case HCI_STATE_WORKING:
1055             switch (power_mode){
1056                 case HCI_POWER_ON:
1057                     // do nothing
1058                     break;
1059                 case HCI_POWER_OFF:
1060                     // see hci_run
1061                     hci_stack.state = HCI_STATE_HALTING;
1062                     break;
1063                 case HCI_POWER_SLEEP:
1064                     // see hci_run
1065                     hci_stack.state = HCI_STATE_FALLING_ASLEEP;
1066                     hci_stack.substate = 0;
1067                     break;
1068             }
1069             break;
1070 
1071         case HCI_STATE_HALTING:
1072             switch (power_mode){
1073                 case HCI_POWER_ON:
1074                     // set up state machine
1075                     hci_stack.state = HCI_STATE_INITIALIZING;
1076                     hci_stack.substate = 0;
1077                     break;
1078                 case HCI_POWER_OFF:
1079                     // do nothing
1080                     break;
1081                 case HCI_POWER_SLEEP:
1082                     // see hci_run
1083                     hci_stack.state = HCI_STATE_FALLING_ASLEEP;
1084                     hci_stack.substate = 0;
1085                     break;
1086             }
1087             break;
1088 
1089         case HCI_STATE_FALLING_ASLEEP:
1090             switch (power_mode){
1091                 case HCI_POWER_ON:
1092 
1093 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1094                     // nothing to do, if H4 supports power management
1095                     if (bt_control_iphone_power_management_enabled()){
1096                         hci_stack.state = HCI_STATE_INITIALIZING;
1097                         hci_stack.substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1098                         break;
1099                     }
1100 #endif
1101                     // set up state machine
1102                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
1103                     hci_stack.state = HCI_STATE_INITIALIZING;
1104                     hci_stack.substate = 0;
1105                     break;
1106                 case HCI_POWER_OFF:
1107                     // see hci_run
1108                     hci_stack.state = HCI_STATE_HALTING;
1109                     break;
1110                 case HCI_POWER_SLEEP:
1111                     // do nothing
1112                     break;
1113             }
1114             break;
1115 
1116         case HCI_STATE_SLEEPING:
1117             switch (power_mode){
1118                 case HCI_POWER_ON:
1119 
1120 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1121                     // nothing to do, if H4 supports power management
1122                     if (bt_control_iphone_power_management_enabled()){
1123                         hci_stack.state = HCI_STATE_INITIALIZING;
1124                         hci_stack.substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1125                         hci_update_scan_enable();
1126                         break;
1127                     }
1128 #endif
1129                     err = hci_power_control_wake();
1130                     if (err) return err;
1131                     // set up state machine
1132                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
1133                     hci_stack.state = HCI_STATE_INITIALIZING;
1134                     hci_stack.substate = 0;
1135                     break;
1136                 case HCI_POWER_OFF:
1137                     hci_stack.state = HCI_STATE_HALTING;
1138                     break;
1139                 case HCI_POWER_SLEEP:
1140                     // do nothing
1141                     break;
1142             }
1143             break;
1144     }
1145 
1146     // create internal event
1147 	hci_emit_state();
1148 
1149 	// trigger next/first action
1150 	hci_run();
1151 
1152     return 0;
1153 }
1154 
1155 static void hci_update_scan_enable(void){
1156     // 2 = page scan, 1 = inq scan
1157     hci_stack.new_scan_enable_value  = hci_stack.connectable << 1 | hci_stack.discoverable;
1158     hci_run();
1159 }
1160 
1161 void hci_discoverable_control(uint8_t enable){
1162     if (enable) enable = 1; // normalize argument
1163 
1164     if (hci_stack.discoverable == enable){
1165         hci_emit_discoverable_enabled(hci_stack.discoverable);
1166         return;
1167     }
1168 
1169     hci_stack.discoverable = enable;
1170     hci_update_scan_enable();
1171 }
1172 
1173 void hci_connectable_control(uint8_t enable){
1174     if (enable) enable = 1; // normalize argument
1175 
1176     // don't emit event
1177     if (hci_stack.connectable == enable) return;
1178 
1179     hci_stack.connectable = enable;
1180     hci_update_scan_enable();
1181 }
1182 
1183 bd_addr_t * hci_local_bd_addr(void){
1184     return &hci_stack.local_bd_addr;
1185 }
1186 
1187 void hci_run(){
1188 
1189     hci_connection_t * connection;
1190     linked_item_t * it;
1191 
1192     if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1193 
1194     // global/non-connection oriented commands
1195 
1196     // decline incoming connections
1197     if (hci_stack.decline_reason){
1198         uint8_t reason = hci_stack.decline_reason;
1199         hci_stack.decline_reason = 0;
1200         hci_send_cmd(&hci_reject_connection_request, hci_stack.decline_addr, reason);
1201         return;
1202     }
1203 
1204     // send scan enable
1205     if (hci_stack.state == HCI_STATE_WORKING && hci_stack.new_scan_enable_value != 0xff && hci_classic_supported()){
1206         hci_send_cmd(&hci_write_scan_enable, hci_stack.new_scan_enable_value);
1207         hci_stack.new_scan_enable_value = 0xff;
1208         return;
1209     }
1210 
1211     // send pending HCI commands
1212     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
1213 
1214         connection = (hci_connection_t *) it;
1215 
1216         if (connection->state == RECEIVED_CONNECTION_REQUEST){
1217             log_info("sending hci_accept_connection_request\n");
1218             hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1219             connection->state = ACCEPTED_CONNECTION_REQUEST;
1220             return;
1221         }
1222 
1223         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1224             link_key_t link_key;
1225             link_key_type_t link_key_type;
1226             log_info("responding to link key request\n");
1227             if ( hci_stack.bondable && hci_stack.remote_device_db && hci_stack.remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
1228                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1229             } else {
1230                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1231             }
1232             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1233             return;
1234         }
1235 
1236         if (connection->authentication_flags & HANDLE_PIN_CODE_REQUEST){
1237             log_info("denying to pin request\n");
1238             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1239             connectionClearAuthenticationFlags(connection, HANDLE_PIN_CODE_REQUEST);
1240             return;
1241         }
1242 
1243         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1244             if (hci_stack.bondable){
1245                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack.ssp_io_capability, NULL, hci_stack.ssp_authentication_requirement);
1246             } else {
1247                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1248             }
1249             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1250             return;
1251         }
1252 
1253         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1254             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1255             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1256             return;
1257         }
1258 
1259         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1260             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1261             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1262             return;
1263         }
1264 
1265         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1266             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1267             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1268         }
1269     }
1270 
1271     switch (hci_stack.state){
1272         case HCI_STATE_INITIALIZING:
1273             // log_info("hci_init: substate %u\n", hci_stack.substate);
1274             if (hci_stack.substate % 2) {
1275                 // odd: waiting for command completion
1276                 return;
1277             }
1278             switch (hci_stack.substate >> 1){
1279                 case 0: // RESET
1280                     hci_send_cmd(&hci_reset);
1281 
1282                     if (hci_stack.config == 0 || ((hci_uart_config_t *)hci_stack.config)->baudrate_main == 0){
1283                         // skip baud change
1284                         hci_stack.substate = 4; // >> 1 = 2
1285                     }
1286                     break;
1287                 case 1: // SEND BAUD CHANGE
1288                     hci_stack.control->baudrate_cmd(hci_stack.config, ((hci_uart_config_t *)hci_stack.config)->baudrate_main, hci_stack.hci_packet_buffer);
1289                     hci_send_cmd_packet(hci_stack.hci_packet_buffer, 3 + hci_stack.hci_packet_buffer[2]);
1290                     break;
1291                 case 2: // LOCAL BAUD CHANGE
1292                     hci_stack.hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack.config)->baudrate_main);
1293                     hci_stack.substate += 2;
1294                     // break missing here for fall through
1295 
1296                 case 3:
1297                     // Custom initialization
1298                     if (hci_stack.control && hci_stack.control->next_cmd){
1299                         int valid_cmd = (*hci_stack.control->next_cmd)(hci_stack.config, hci_stack.hci_packet_buffer);
1300                         if (valid_cmd){
1301                             int size = 3 + hci_stack.hci_packet_buffer[2];
1302                             hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack.hci_packet_buffer, size);
1303                             hci_stack.substate = 4; // more init commands
1304                             break;
1305                         }
1306                         log_info("hci_run: init script done\n\r");
1307                     }
1308                     // otherwise continue
1309 					hci_send_cmd(&hci_read_bd_addr);
1310 					break;
1311 				case 4:
1312 					hci_send_cmd(&hci_read_buffer_size);
1313 					break;
1314                 case 5:
1315                     hci_send_cmd(&hci_read_local_supported_features);
1316                     break;
1317                 case 6:
1318                     if (hci_le_supported()){
1319                         hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1320                     } else {
1321                         // Kensington Bluetoot 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1322                         hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1323                     }
1324 
1325                     // skip Classic init commands for LE only chipsets
1326                     if (!hci_classic_supported()){
1327                         if (hci_le_supported()){
1328                             hci_stack.substate = 11 << 1;    // skip all classic command
1329                         } else {
1330                             log_error("Neither BR/EDR nor LE supported");
1331                             hci_stack.substate = 13 << 1;    // skip all
1332                         }
1333                     }
1334                     break;
1335                 case 7:
1336                     if (hci_ssp_supported()){
1337                         hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack.ssp_enable);
1338                         break;
1339                     }
1340                     hci_stack.substate += 2;
1341                     // break missing here for fall through
1342 
1343                 case 8:
1344                     // ca. 15 sec
1345                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
1346                     break;
1347                 case 9:
1348                     hci_send_cmd(&hci_write_class_of_device, hci_stack.class_of_device);
1349                     break;
1350                 case 10:
1351                     if (hci_stack.local_name){
1352                         hci_send_cmd(&hci_write_local_name, hci_stack.local_name);
1353                     } else {
1354                         char hostname[30];
1355 #ifdef EMBEDDED
1356                         // BTstack-11:22:33:44:55:66
1357                         strcpy(hostname, "BTstack ");
1358                         strcat(hostname, bd_addr_to_str(hci_stack.local_bd_addr));
1359                         printf("---> Name %s\n", hostname);
1360 #else
1361                         // hostname for POSIX systems
1362                         gethostname(hostname, 30);
1363                         hostname[29] = '\0';
1364 #endif
1365                         hci_send_cmd(&hci_write_local_name, hostname);
1366                     }
1367                     break;
1368                 case 11:
1369 					hci_send_cmd(&hci_write_scan_enable, (hci_stack.connectable << 1) | hci_stack.discoverable); // page scan
1370                     if (!hci_le_supported()){
1371                         // SKIP LE init for Classic only configuration
1372                         hci_stack.substate = 13 << 1;
1373                     }
1374 					break;
1375 
1376 #ifdef HAVE_BLE
1377                 // LE INIT
1378                 case 12:
1379                     hci_send_cmd(&hci_le_read_buffer_size);
1380                     break;
1381                 case 13:
1382                     // LE Supported Host = 1, Simultaneous Host = 0
1383                     hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1384                     break;
1385 #endif
1386 
1387                 // DONE
1388                 case 14:
1389                     // done.
1390                     hci_stack.state = HCI_STATE_WORKING;
1391                     hci_emit_state();
1392                     break;
1393                 default:
1394                     break;
1395             }
1396             hci_stack.substate++;
1397             break;
1398 
1399         case HCI_STATE_HALTING:
1400 
1401             log_info("HCI_STATE_HALTING\n");
1402             // close all open connections
1403             connection =  (hci_connection_t *) hci_stack.connections;
1404             if (connection){
1405 
1406                 // send disconnect
1407                 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1408 
1409                 log_info("HCI_STATE_HALTING, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1410                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1411 
1412                 // send disconnected event right away - causes higher layer connections to get closed, too.
1413                 hci_shutdown_connection(connection);
1414                 return;
1415             }
1416             log_info("HCI_STATE_HALTING, calling off\n");
1417 
1418             // switch mode
1419             hci_power_control_off();
1420 
1421             log_info("HCI_STATE_HALTING, emitting state\n");
1422             hci_emit_state();
1423             log_info("HCI_STATE_HALTING, done\n");
1424             break;
1425 
1426         case HCI_STATE_FALLING_ASLEEP:
1427             switch(hci_stack.substate) {
1428                 case 0:
1429                     log_info("HCI_STATE_FALLING_ASLEEP\n");
1430                     // close all open connections
1431                     connection =  (hci_connection_t *) hci_stack.connections;
1432 
1433 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1434                     // don't close connections, if H4 supports power management
1435                     if (bt_control_iphone_power_management_enabled()){
1436                         connection = NULL;
1437                     }
1438 #endif
1439                     if (connection){
1440 
1441                         // send disconnect
1442                         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1443 
1444                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1445                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1446 
1447                         // send disconnected event right away - causes higher layer connections to get closed, too.
1448                         hci_shutdown_connection(connection);
1449                         return;
1450                     }
1451 
1452                     if (hci_classic_supported()){
1453                         // disable page and inquiry scan
1454                         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1455 
1456                         log_info("HCI_STATE_HALTING, disabling inq scans\n");
1457                         hci_send_cmd(&hci_write_scan_enable, hci_stack.connectable << 1); // drop inquiry scan but keep page scan
1458 
1459                         // continue in next sub state
1460                         hci_stack.substate++;
1461                         break;
1462                     }
1463                     // fall through for ble-only chips
1464 
1465                 case 2:
1466                     log_info("HCI_STATE_HALTING, calling sleep\n");
1467 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1468                     // don't actually go to sleep, if H4 supports power management
1469                     if (bt_control_iphone_power_management_enabled()){
1470                         // SLEEP MODE reached
1471                         hci_stack.state = HCI_STATE_SLEEPING;
1472                         hci_emit_state();
1473                         break;
1474                     }
1475 #endif
1476                     // switch mode
1477                     hci_power_control_sleep();  // changes hci_stack.state to SLEEP
1478                     hci_emit_state();
1479                     break;
1480 
1481                 default:
1482                     break;
1483             }
1484             break;
1485 
1486         default:
1487             break;
1488     }
1489 }
1490 
1491 int hci_send_cmd_packet(uint8_t *packet, int size){
1492     bd_addr_t addr;
1493     hci_connection_t * conn;
1494     // house-keeping
1495 
1496     // create_connection?
1497     if (IS_COMMAND(packet, hci_create_connection)){
1498         bt_flip_addr(addr, &packet[3]);
1499         log_info("Create_connection to %s\n", bd_addr_to_str(addr));
1500         conn = connection_for_address(addr);
1501         if (conn) {
1502             // if connection exists
1503             if (conn->state == OPEN) {
1504                 // and OPEN, emit connection complete command
1505                 hci_emit_connection_complete(conn, 0);
1506             }
1507             //    otherwise, just ignore as it is already in the open process
1508             return 0; // don't sent packet to controller
1509 
1510         }
1511         // create connection struct and register, state = SENT_CREATE_CONNECTION
1512         conn = create_connection_for_addr(addr);
1513         if (!conn){
1514             // notify client that alloc failed
1515             hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
1516             return 0; // don't sent packet to controller
1517         }
1518         conn->state = SENT_CREATE_CONNECTION;
1519     }
1520 
1521     if (IS_COMMAND(packet, hci_link_key_request_reply)){
1522         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
1523     }
1524     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
1525         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
1526     }
1527     // if (IS_COMMAND(packet, hci_pin_code_request_reply)){
1528     //     hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_REPLY);
1529     // }
1530     // if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)){
1531     //     hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_NEGATIVE_REPLY);
1532     // }
1533 
1534     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
1535         if (hci_stack.remote_device_db){
1536             bt_flip_addr(addr, &packet[3]);
1537             hci_stack.remote_device_db->delete_link_key(&addr);
1538         }
1539     }
1540 
1541 #ifdef HAVE_BLE
1542     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
1543         hci_stack.adv_addr_type = packet[8];
1544     }
1545     if (IS_COMMAND(packet, hci_le_set_random_address)){
1546         bt_flip_addr(hci_stack.adv_address, &packet[3]);
1547     }
1548 #endif
1549 
1550 
1551     hci_stack.num_cmd_packets--;
1552     return hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
1553 }
1554 
1555 // Configure Secure Simple Pairing
1556 
1557 // enable will enable SSP during init
1558 void hci_ssp_set_enable(int enable){
1559     hci_stack.ssp_enable = enable;
1560 }
1561 
1562 // if set, BTstack will respond to io capability request using authentication requirement
1563 void hci_ssp_set_io_capability(int io_capability){
1564     hci_stack.ssp_io_capability = io_capability;
1565 }
1566 void hci_ssp_set_authentication_requirement(int authentication_requirement){
1567     hci_stack.ssp_authentication_requirement = authentication_requirement;
1568 }
1569 
1570 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
1571 void hci_ssp_set_auto_accept(int auto_accept){
1572     hci_stack.ssp_auto_accept = auto_accept;
1573 }
1574 
1575 /**
1576  * pre: numcmds >= 0 - it's allowed to send a command to the controller
1577  */
1578 int hci_send_cmd(const hci_cmd_t *cmd, ...){
1579     va_list argptr;
1580     va_start(argptr, cmd);
1581     uint16_t size = hci_create_cmd_internal(hci_stack.hci_packet_buffer, cmd, argptr);
1582     va_end(argptr);
1583     return hci_send_cmd_packet(hci_stack.hci_packet_buffer, size);
1584 }
1585 
1586 // Create various non-HCI events.
1587 // TODO: generalize, use table similar to hci_create_command
1588 
1589 void hci_emit_state(){
1590     log_info("BTSTACK_EVENT_STATE %u", hci_stack.state);
1591     uint8_t event[3];
1592     event[0] = BTSTACK_EVENT_STATE;
1593     event[1] = sizeof(event) - 2;
1594     event[2] = hci_stack.state;
1595     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1596     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1597 }
1598 
1599 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
1600     uint8_t event[13];
1601     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
1602     event[1] = sizeof(event) - 2;
1603     event[2] = status;
1604     bt_store_16(event, 3, conn->con_handle);
1605     bt_flip_addr(&event[5], conn->address);
1606     event[11] = 1; // ACL connection
1607     event[12] = 0; // encryption disabled
1608     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1609     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1610 }
1611 
1612 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
1613     uint8_t event[6];
1614     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
1615     event[1] = sizeof(event) - 2;
1616     event[2] = 0; // status = OK
1617     bt_store_16(event, 3, handle);
1618     event[5] = reason;
1619     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1620     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1621 }
1622 
1623 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
1624     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
1625     uint8_t event[4];
1626     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
1627     event[1] = sizeof(event) - 2;
1628     bt_store_16(event, 2, conn->con_handle);
1629     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1630     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1631 }
1632 
1633 void hci_emit_nr_connections_changed(){
1634     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
1635     uint8_t event[3];
1636     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
1637     event[1] = sizeof(event) - 2;
1638     event[2] = nr_hci_connections();
1639     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1640     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1641 }
1642 
1643 void hci_emit_hci_open_failed(){
1644     log_info("BTSTACK_EVENT_POWERON_FAILED");
1645     uint8_t event[2];
1646     event[0] = BTSTACK_EVENT_POWERON_FAILED;
1647     event[1] = sizeof(event) - 2;
1648     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1649     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1650 }
1651 
1652 #ifndef EMBEDDED
1653 void hci_emit_btstack_version() {
1654     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
1655     uint8_t event[6];
1656     event[0] = BTSTACK_EVENT_VERSION;
1657     event[1] = sizeof(event) - 2;
1658     event[2] = BTSTACK_MAJOR;
1659     event[3] = BTSTACK_MINOR;
1660     bt_store_16(event, 4, BTSTACK_REVISION);
1661     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1662     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1663 }
1664 #endif
1665 
1666 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
1667     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
1668     uint8_t event[3];
1669     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
1670     event[1] = sizeof(event) - 2;
1671     event[2] = enabled;
1672     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1673     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1674 }
1675 
1676 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
1677     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
1678     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
1679     event[1] = sizeof(event) - 2 - 1;
1680     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
1681     bt_flip_addr(&event[3], *addr);
1682     memcpy(&event[9], name, 248);
1683 
1684     event[9+248] = 0;   // assert \0 for log_info
1685     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
1686 
1687     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
1688     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
1689 }
1690 
1691 void hci_emit_discoverable_enabled(uint8_t enabled){
1692     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
1693     uint8_t event[3];
1694     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
1695     event[1] = sizeof(event) - 2;
1696     event[2] = enabled;
1697     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1698     hci_stack.packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1699 }
1700 
1701 // GAP API
1702 /**
1703  * @bbrief enable/disable bonding. default is enabled
1704  * @praram enabled
1705  */
1706 void gap_set_bondable_mode(int enable){
1707     hci_stack.bondable = enable ? 1 : 0;
1708 }
1709 
1710 /**
1711  * @brief get current security level
1712  */
1713 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
1714     return LEVEL_0;
1715 }
1716 
1717 /**
1718  * @brief request connection to device to
1719  * @result GAP_AUTHENTICATION_RESULT
1720  */
1721 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
1722 }
1723