xref: /btstack/src/hci.c (revision 68a0fcf7e245a4ad0824398b64b876fd4233fc06)
1 /*
2  * Copyright (C) 2009-2012 by Matthias Ringwald
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at [email protected]
34  *
35  */
36 
37 /*
38  *  hci.c
39  *
40  *  Created by Matthias Ringwald on 4/29/09.
41  *
42  */
43 
44 #include "btstack-config.h"
45 
46 #include "hci.h"
47 #include "gap.h"
48 
49 #include <stdarg.h>
50 #include <string.h>
51 #include <stdio.h>
52 
53 #ifndef EMBEDDED
54 #include <unistd.h> // gethostbyname
55 #include <btstack/version.h>
56 #endif
57 
58 #include "btstack_memory.h"
59 #include "debug.h"
60 #include "hci_dump.h"
61 
62 #include <btstack/hci_cmds.h>
63 
64 #define HCI_CONNECTION_TIMEOUT_MS 10000
65 
66 #define HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP 11
67 
68 #ifdef USE_BLUETOOL
69 #include "bt_control_iphone.h"
70 #endif
71 
72 static void hci_update_scan_enable(void);
73 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
74 
75 // the STACK is here
76 #ifndef HAVE_MALLOC
77 static hci_stack_t   hci_stack_static;
78 #endif
79 static hci_stack_t * hci_stack = NULL;
80 
81 // test helper
82 static uint8_t disable_l2cap_timeouts = 0;
83 
84 
85 /**
86  * get connection for a given handle
87  *
88  * @return connection OR NULL, if not found
89  */
90 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
91     linked_item_t *it;
92     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
93         if ( ((hci_connection_t *) it)->con_handle == con_handle){
94             return (hci_connection_t *) it;
95         }
96     }
97     return NULL;
98 }
99 
100 hci_connection_t * hci_connection_for_bd_addr(bd_addr_t * addr){
101     linked_item_t *it;
102     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
103         hci_connection_t * connection = (hci_connection_t *) it;
104         if (memcmp(addr, connection->address, 6) == 0) {
105             return connection;
106         }
107     }
108     return NULL;
109 }
110 
111 static void hci_connection_timeout_handler(timer_source_t *timer){
112     hci_connection_t * connection = (hci_connection_t *) linked_item_get_user(&timer->item);
113 #ifdef HAVE_TIME
114     struct timeval tv;
115     gettimeofday(&tv, NULL);
116     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
117         // connections might be timed out
118         hci_emit_l2cap_check_timeout(connection);
119     }
120 #endif
121 #ifdef HAVE_TICK
122     if (embedded_get_ticks() > connection->timestamp + embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
123         // connections might be timed out
124         hci_emit_l2cap_check_timeout(connection);
125     }
126 #endif
127     run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
128     run_loop_add_timer(timer);
129 }
130 
131 static void hci_connection_timestamp(hci_connection_t *connection){
132 #ifdef HAVE_TIME
133     gettimeofday(&connection->timestamp, NULL);
134 #endif
135 #ifdef HAVE_TICK
136     connection->timestamp = embedded_get_ticks();
137 #endif
138 }
139 
140 /**
141  * create connection for given address
142  *
143  * @return connection OR NULL, if no memory left
144  */
145 static hci_connection_t * create_connection_for_addr(bd_addr_t addr){
146 
147     printf("create_connection_for_addr %s\n", bd_addr_to_str(addr));
148     hci_connection_t * conn = (hci_connection_t *) btstack_memory_hci_connection_get();
149     if (!conn) return NULL;
150     BD_ADDR_COPY(conn->address, addr);
151     conn->con_handle = 0xffff;
152     conn->authentication_flags = AUTH_FLAGS_NONE;
153     conn->bonding_flags = 0;
154     conn->requested_security_level = LEVEL_0;
155     linked_item_set_user(&conn->timeout.item, conn);
156     conn->timeout.process = hci_connection_timeout_handler;
157     hci_connection_timestamp(conn);
158     conn->acl_recombination_length = 0;
159     conn->acl_recombination_pos = 0;
160     conn->num_acl_packets_sent = 0;
161     linked_list_add(&hci_stack->connections, (linked_item_t *) conn);
162     return conn;
163 }
164 
165 /**
166  * get connection for given address
167  *
168  * @return connection OR NULL, if not found
169  */
170 static hci_connection_t * connection_for_address(bd_addr_t address){
171     linked_item_t *it;
172     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
173         if ( ! BD_ADDR_CMP( ((hci_connection_t *) it)->address, address) ){
174             return (hci_connection_t *) it;
175         }
176     }
177     return NULL;
178 }
179 
180 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
181     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
182 }
183 
184 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
185     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
186 }
187 
188 
189 /**
190  * add authentication flags and reset timer
191  */
192 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
193     bd_addr_t addr;
194     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
195     hci_connection_t * conn = connection_for_address(addr);
196     if (conn) {
197         connectionSetAuthenticationFlags(conn, flags);
198         hci_connection_timestamp(conn);
199     }
200 }
201 
202 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
203     hci_connection_t * conn = hci_connection_for_handle(handle);
204     if (!conn) return 0;
205     if (conn->authentication_flags & LEGACY_PAIRING_ACTIVE) return 1;
206     if (conn->authentication_flags & SSP_PAIRING_ACTIVE) return 1;
207     return 0;
208 }
209 
210 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
211     if (hci_stack->remote_device_db) {
212         hci_stack->remote_device_db->delete_link_key(addr);
213     }
214 }
215 
216 
217 /**
218  * count connections
219  */
220 static int nr_hci_connections(void){
221     int count = 0;
222     linked_item_t *it;
223     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next, count++);
224     return count;
225 }
226 
227 /**
228  * Dummy handler called by HCI
229  */
230 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
231 }
232 
233 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
234     hci_connection_t * connection = hci_connection_for_handle(handle);
235     if (!connection) {
236         log_error("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
237         return 0;
238     }
239     return connection->num_acl_packets_sent;
240 }
241 
242 uint8_t hci_number_free_acl_slots(){
243     uint8_t free_slots = hci_stack->total_num_acl_packets;
244     linked_item_t *it;
245     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
246         hci_connection_t * connection = (hci_connection_t *) it;
247         if (free_slots < connection->num_acl_packets_sent) {
248             log_error("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
249             return 0;
250         }
251         free_slots -= connection->num_acl_packets_sent;
252     }
253     return free_slots;
254 }
255 
256 int hci_can_send_packet_now(uint8_t packet_type){
257 
258     // check for async hci transport implementations
259     if (hci_stack->hci_transport->can_send_packet_now){
260         if (!hci_stack->hci_transport->can_send_packet_now(packet_type)){
261             return 0;
262         }
263     }
264 
265     // check regular Bluetooth flow control
266     switch (packet_type) {
267         case HCI_ACL_DATA_PACKET:
268             return hci_number_free_acl_slots();
269         case HCI_COMMAND_DATA_PACKET:
270             return hci_stack->num_cmd_packets;
271         default:
272             return 0;
273     }
274 }
275 
276 // same as hci_can_send_packet_now, but also checks if packet buffer is free for use
277 int hci_can_send_packet_now_using_packet_buffer(uint8_t packet_type){
278     if (hci_stack->hci_packet_buffer_reserved) return 0;
279     return hci_can_send_packet_now(packet_type);
280 }
281 
282 // used for internal checks in l2cap[-le].c
283 int hci_is_packet_buffer_reserved(void){
284     return hci_stack->hci_packet_buffer_reserved;
285 }
286 
287 // reserves outgoing packet buffer. @returns 1 if successful
288 int hci_reserve_packet_buffer(void){
289     if (hci_stack->hci_packet_buffer_reserved) return 0;
290     hci_stack->hci_packet_buffer_reserved = 1;
291     return 1;
292 }
293 
294 void hci_release_packet_buffer(void){
295     hci_stack->hci_packet_buffer_reserved = 0;
296 }
297 
298 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
299 int hci_transport_synchronous(void){
300     return hci_stack->hci_transport->can_send_packet_now == NULL;
301 }
302 
303 int hci_send_acl_packet(uint8_t *packet, int size){
304 
305     // check for free places on BT module
306     if (!hci_number_free_acl_slots()) return BTSTACK_ACL_BUFFERS_FULL;
307 
308     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
309     hci_connection_t *connection = hci_connection_for_handle( con_handle);
310     if (!connection) return 0;
311     hci_connection_timestamp(connection);
312 
313     // count packet
314     connection->num_acl_packets_sent++;
315     // log_info("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
316 
317     // send packet
318     int err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
319 
320     // free packet buffer for synchronous transport implementations
321     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
322         hci_stack->hci_packet_buffer_reserved = 0;
323     }
324 
325     return err;
326 }
327 
328 static void acl_handler(uint8_t *packet, int size){
329 
330     // log_info("acl_handler: size %u", size);
331 
332     // get info
333     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
334     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
335     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
336     uint16_t acl_length         = READ_ACL_LENGTH(packet);
337 
338     // ignore non-registered handle
339     if (!conn){
340         log_error( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
341         return;
342     }
343 
344     // assert packet is complete
345     if (acl_length + 4 != size){
346         log_error("hci.c: acl_handler called with ACL packet of wrong size %u, expected %u => dropping packet", size, acl_length + 4);
347         return;
348     }
349 
350     // update idle timestamp
351     hci_connection_timestamp(conn);
352 
353     // handle different packet types
354     switch (acl_flags & 0x03) {
355 
356         case 0x01: // continuation fragment
357 
358             // sanity check
359             if (conn->acl_recombination_pos == 0) {
360                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
361                 return;
362             }
363 
364             // append fragment payload (header already stored)
365             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
366             conn->acl_recombination_pos += acl_length;
367 
368             // log_error( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n", acl_length,
369             //        conn->acl_recombination_pos, conn->acl_recombination_length);
370 
371             // forward complete L2CAP packet if complete.
372             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
373 
374                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
375                 // reset recombination buffer
376                 conn->acl_recombination_length = 0;
377                 conn->acl_recombination_pos = 0;
378             }
379             break;
380 
381         case 0x02: { // first fragment
382 
383             // sanity check
384             if (conn->acl_recombination_pos) {
385                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
386                 return;
387             }
388 
389             // peek into L2CAP packet!
390             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
391 
392             // log_info( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
393 
394             // compare fragment size to L2CAP packet size
395             if (acl_length >= l2cap_length + 4){
396 
397                 // forward fragment as L2CAP packet
398                 hci_stack->packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
399 
400             } else {
401                 // store first fragment and tweak acl length for complete package
402                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
403                 conn->acl_recombination_pos    = acl_length + 4;
404                 conn->acl_recombination_length = l2cap_length;
405                 bt_store_16(conn->acl_recombination_buffer, 2, l2cap_length +4);
406             }
407             break;
408 
409         }
410         default:
411             log_error( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
412             return;
413     }
414 
415     // execute main loop
416     hci_run();
417 }
418 
419 static void hci_shutdown_connection(hci_connection_t *conn){
420     log_info("Connection closed: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
421 
422     // cancel all l2cap connections
423     hci_emit_disconnection_complete(conn->con_handle, 0x16);    // terminated by local host
424 
425     run_loop_remove_timer(&conn->timeout);
426 
427     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
428     btstack_memory_hci_connection_free( conn );
429 
430     // now it's gone
431     hci_emit_nr_connections_changed();
432 }
433 
434 static const uint16_t packet_type_sizes[] = {
435     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
436     HCI_ACL_DH1_SIZE, 0, 0, 0,
437     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
438     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
439 };
440 static const uint8_t  packet_type_feature_requirement_bit[] = {
441      0, // 3 slot packets
442      1, // 5 slot packets
443     25, // EDR 2 mpbs
444     26, // EDR 3 mbps
445     39, // 3 slot EDR packts
446     40, // 5 slot EDR packet
447 };
448 static const uint16_t packet_type_feature_packet_mask[] = {
449     0x0f00, // 3 slot packets
450     0xf000, // 5 slot packets
451     0x1102, // EDR 2 mpbs
452     0x2204, // EDR 3 mbps
453     0x0300, // 3 slot EDR packts
454     0x3000, // 5 slot EDR packet
455 };
456 
457 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
458     // enable packet types based on size
459     uint16_t packet_types = 0;
460     int i;
461     for (i=0;i<16;i++){
462         if (packet_type_sizes[i] == 0) continue;
463         if (packet_type_sizes[i] <= buffer_size){
464             packet_types |= 1 << i;
465         }
466     }
467     // disable packet types due to missing local supported features
468     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
469         int bit_idx = packet_type_feature_requirement_bit[i];
470         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
471         if (feature_set) continue;
472         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
473         packet_types &= ~packet_type_feature_packet_mask[i];
474     }
475     // flip bits for "may not be used"
476     packet_types ^= 0x3306;
477     return packet_types;
478 }
479 
480 uint16_t hci_usable_acl_packet_types(void){
481     return hci_stack->packet_types;
482 }
483 
484 uint8_t* hci_get_outgoing_packet_buffer(void){
485     // hci packet buffer is >= acl data packet length
486     return hci_stack->hci_packet_buffer;
487 }
488 
489 uint16_t hci_max_acl_data_packet_length(void){
490     return hci_stack->acl_data_packet_length;
491 }
492 
493 int hci_ssp_supported(void){
494     // No 51, byte 6, bit 3
495     return (hci_stack->local_supported_features[6] & (1 << 3)) != 0;
496 }
497 
498 int hci_classic_supported(void){
499     // No 37, byte 4, bit 5, = No BR/EDR Support
500     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
501 }
502 
503 int hci_le_supported(void){
504     // No 37, byte 4, bit 6 = LE Supported (Controller)
505 #ifdef HAVE_BLE
506     return (hci_stack->local_supported_features[4] & (1 << 6)) != 0;
507 #else
508     return 0;
509 #endif
510 }
511 
512 // get addr type and address used in advertisement packets
513 void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t * addr){
514     *addr_type = hci_stack->adv_addr_type;
515     if (hci_stack->adv_addr_type){
516         memcpy(addr, hci_stack->adv_address, 6);
517     } else {
518         memcpy(addr, hci_stack->local_bd_addr, 6);
519     }
520 }
521 
522 // avoid huge local variables
523 #ifndef EMBEDDED
524 static device_name_t device_name;
525 #endif
526 static void event_handler(uint8_t *packet, int size){
527 
528     uint16_t event_length = packet[1];
529 
530     // assert packet is complete
531     if (size != event_length + 2){
532         log_error("hci.c: event_handler called with event packet of wrong size %u, expected %u => dropping packet", size, event_length + 2);
533         return;
534     }
535 
536     bd_addr_t addr;
537     uint8_t link_type;
538     hci_con_handle_t handle;
539     hci_connection_t * conn;
540     int i;
541 
542     // printf("HCI:EVENT:%02x\n", packet[0]);
543 
544     switch (packet[0]) {
545 
546         case HCI_EVENT_COMMAND_COMPLETE:
547             // get num cmd packets
548             // log_info("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u\n", hci_stack->num_cmd_packets, packet[2]);
549             hci_stack->num_cmd_packets = packet[2];
550 
551             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
552                 // from offset 5
553                 // status
554                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
555                 hci_stack->acl_data_packet_length = READ_BT_16(packet, 6);
556                 // ignore: SCO data packet len (8)
557                 hci_stack->total_num_acl_packets  = packet[9];
558                 // ignore: total num SCO packets
559                 if (hci_stack->state == HCI_STATE_INITIALIZING){
560                     // determine usable ACL payload size
561                     if (HCI_ACL_PAYLOAD_SIZE < hci_stack->acl_data_packet_length){
562                         hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
563                     }
564                     log_info("hci_read_buffer_size: used size %u, count %u\n",
565                              hci_stack->acl_data_packet_length, hci_stack->total_num_acl_packets);
566                 }
567             }
568 #ifdef HAVE_BLE
569             if (COMMAND_COMPLETE_EVENT(packet, hci_le_read_buffer_size)){
570                 hci_stack->le_data_packet_length = READ_BT_16(packet, 6);
571                 hci_stack->total_num_le_packets  = packet[8];
572                 log_info("hci_le_read_buffer_size: size %u, count %u\n", hci_stack->le_data_packet_length, hci_stack->total_num_le_packets);
573             }
574 #endif
575             // Dump local address
576             if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)) {
577                 bt_flip_addr(hci_stack->local_bd_addr, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1]);
578                 log_info("Local Address, Status: 0x%02x: Addr: %s\n",
579                     packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
580             }
581             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
582                 hci_emit_discoverable_enabled(hci_stack->discoverable);
583             }
584             // Note: HCI init checks
585             if (COMMAND_COMPLETE_EVENT(packet, hci_read_local_supported_features)){
586                 memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 8);
587                 log_info("Local Supported Features: 0x%02x%02x%02x%02x%02x%02x%02x%02x",
588                     hci_stack->local_supported_features[0], hci_stack->local_supported_features[1],
589                     hci_stack->local_supported_features[2], hci_stack->local_supported_features[3],
590                     hci_stack->local_supported_features[4], hci_stack->local_supported_features[5],
591                     hci_stack->local_supported_features[6], hci_stack->local_supported_features[7]);
592 
593                 // determine usable ACL packet types based buffer size and supported features
594                 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]);
595                 log_info("packet types %04x", hci_stack->packet_types);
596 
597                 // Classic/LE
598                 log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
599             }
600             break;
601 
602         case HCI_EVENT_COMMAND_STATUS:
603             // get num cmd packets
604             // log_info("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u\n", hci_stack->num_cmd_packets, packet[3]);
605             hci_stack->num_cmd_packets = packet[3];
606             break;
607 
608         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
609             for (i=0; i<packet[2];i++){
610                 handle = READ_BT_16(packet, 3 + 2*i);
611                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
612                 conn = hci_connection_for_handle(handle);
613                 if (!conn){
614                     log_error("hci_number_completed_packet lists unused con handle %u\n", handle);
615                     continue;
616                 }
617                 conn->num_acl_packets_sent -= num_packets;
618                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
619             }
620             break;
621 
622         case HCI_EVENT_CONNECTION_REQUEST:
623             bt_flip_addr(addr, &packet[2]);
624             // TODO: eval COD 8-10
625             link_type = packet[11];
626             log_info("Connection_incoming: %s, type %u\n", bd_addr_to_str(addr), link_type);
627             if (link_type == 1) { // ACL
628                 conn = connection_for_address(addr);
629                 if (!conn) {
630                     conn = create_connection_for_addr(addr);
631                 }
632                 if (!conn) {
633                     // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
634                     hci_stack->decline_reason = 0x0d;
635                     BD_ADDR_COPY(hci_stack->decline_addr, addr);
636                     break;
637                 }
638                 conn->state = RECEIVED_CONNECTION_REQUEST;
639                 hci_run();
640             } else {
641                 // SYNCHRONOUS CONNECTION LIMIT TO A DEVICE EXCEEDED (0X0A)
642                 hci_stack->decline_reason = 0x0a;
643                 BD_ADDR_COPY(hci_stack->decline_addr, addr);
644             }
645             break;
646 
647         case HCI_EVENT_CONNECTION_COMPLETE:
648             // Connection management
649             bt_flip_addr(addr, &packet[5]);
650             log_info("Connection_complete (status=%u) %s\n", packet[2], bd_addr_to_str(addr));
651             conn = connection_for_address(addr);
652             if (conn) {
653                 if (!packet[2]){
654                     conn->state = OPEN;
655                     conn->con_handle = READ_BT_16(packet, 3);
656                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES;
657 
658                     // restart timer
659                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
660                     run_loop_add_timer(&conn->timeout);
661 
662                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
663 
664                     hci_emit_nr_connections_changed();
665                 } else {
666                     // notify client if dedicated bonding
667                     if (conn->bonding_flags & BONDING_DEDICATED){
668                         hci_emit_dedicated_bonding_result(conn, packet[2]);
669                     }
670 
671                     // connection failed, remove entry
672                     linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
673                     btstack_memory_hci_connection_free( conn );
674 
675                     // if authentication error, also delete link key
676                     if (packet[2] == 0x05) {
677                         hci_drop_link_key_for_bd_addr(&addr);
678                     }
679                 }
680             }
681             break;
682 
683         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
684             handle = READ_BT_16(packet, 3);
685             conn = hci_connection_for_handle(handle);
686             if (!conn) break;
687             if (!packet[2]){
688                 uint8_t * features = &packet[5];
689                 if (features[6] & (1 << 3)){
690                     conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP;
691                 }
692             }
693             conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
694             log_info("HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE, bonding flags %x", conn->bonding_flags);
695             if (conn->bonding_flags & BONDING_DEDICATED){
696                 conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
697             }
698             break;
699 
700         case HCI_EVENT_LINK_KEY_REQUEST:
701             log_info("HCI_EVENT_LINK_KEY_REQUEST\n");
702             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
703             // non-bondable mode: link key negative reply will be sent by HANDLE_LINK_KEY_REQUEST
704             if (hci_stack->bondable && !hci_stack->remote_device_db) break;
705             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], HANDLE_LINK_KEY_REQUEST);
706             hci_run();
707             // request handled by hci_run() as HANDLE_LINK_KEY_REQUEST gets set
708             return;
709 
710         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
711             bt_flip_addr(addr, &packet[2]);
712             conn = connection_for_address(addr);
713             if (!conn) break;
714             conn->authentication_flags |= RECV_LINK_KEY_NOTIFICATION;
715             link_key_type_t link_key_type = packet[24];
716             // Change Connection Encryption keeps link key type
717             if (link_key_type != CHANGED_COMBINATION_KEY){
718                 conn->link_key_type = link_key_type;
719             }
720             if (!hci_stack->remote_device_db) break;
721             hci_stack->remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8], conn->link_key_type);
722             // still forward event to allow dismiss of pairing dialog
723             break;
724         }
725 
726         case HCI_EVENT_PIN_CODE_REQUEST:
727             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], LEGACY_PAIRING_ACTIVE);
728             // non-bondable mode: pin code negative reply will be sent
729             if (!hci_stack->bondable){
730                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], DENY_PIN_CODE_REQUEST);
731                 hci_run();
732                 return;
733             }
734             // PIN CODE REQUEST means the link key request didn't succee -> delete stored link key
735             if (!hci_stack->remote_device_db) break;
736             bt_flip_addr(addr, &packet[2]);
737             hci_stack->remote_device_db->delete_link_key(&addr);
738             break;
739 
740         case HCI_EVENT_IO_CAPABILITY_REQUEST:
741             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_IO_CAPABILITIES_REQUEST);
742             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_IO_CAPABILITIES_REPLY);
743             break;
744 
745         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
746             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
747             if (!hci_stack->ssp_auto_accept) break;
748             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_CONFIRM_REPLY);
749             break;
750 
751         case HCI_EVENT_USER_PASSKEY_REQUEST:
752             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SSP_PAIRING_ACTIVE);
753             if (!hci_stack->ssp_auto_accept) break;
754             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], SEND_USER_PASSKEY_REPLY);
755             break;
756 
757         case HCI_EVENT_ENCRYPTION_CHANGE:
758             handle = READ_BT_16(packet, 3);
759             conn = hci_connection_for_handle(handle);
760             if (!conn) break;
761             if (packet[2] == 0) {
762                 if (packet[5]){
763                     conn->authentication_flags |= CONNECTION_ENCRYPTED;
764                 } else {
765                     conn->authentication_flags &= ~CONNECTION_ENCRYPTED;
766                 }
767             }
768             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
769             break;
770 
771         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
772             handle = READ_BT_16(packet, 3);
773             conn = hci_connection_for_handle(handle);
774             if (!conn) break;
775 
776             // dedicated bonding: send result and disconnect
777             if (conn->bonding_flags & BONDING_DEDICATED){
778                 conn->bonding_flags &= ~BONDING_DEDICATED;
779                 hci_emit_dedicated_bonding_result( conn, packet[2]);
780                 conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
781                 break;
782             }
783 
784             if (packet[2] == 0 && gap_security_level_for_link_key_type(conn->link_key_type) >= conn->requested_security_level){
785                 // link key sufficient for requested security
786                 conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
787                 break;
788             }
789             // not enough
790             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
791             break;
792 
793 #ifndef EMBEDDED
794         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
795             if (!hci_stack->remote_device_db) break;
796             if (packet[2]) break; // status not ok
797             bt_flip_addr(addr, &packet[3]);
798             // fix for invalid remote names - terminate on 0xff
799             for (i=0; i<248;i++){
800                 if (packet[9+i] == 0xff){
801                     packet[9+i] = 0;
802                     break;
803                 }
804             }
805             memset(&device_name, 0, sizeof(device_name_t));
806             strncpy((char*) device_name, (char*) &packet[9], 248);
807             hci_stack->remote_device_db->put_name(&addr, &device_name);
808             break;
809 
810         case HCI_EVENT_INQUIRY_RESULT:
811         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
812             if (!hci_stack->remote_device_db) break;
813             // first send inq result packet
814             hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
815             // then send cached remote names
816             for (i=0; i<packet[2];i++){
817                 bt_flip_addr(addr, &packet[3+i*6]);
818                 if (hci_stack->remote_device_db->get_name(&addr, &device_name)){
819                     hci_emit_remote_name_cached(&addr, &device_name);
820                 }
821             }
822             return;
823 #endif
824 
825         case HCI_EVENT_DISCONNECTION_COMPLETE:
826             if (!packet[2]){
827                 handle = READ_BT_16(packet, 3);
828                 hci_connection_t * conn = hci_connection_for_handle(handle);
829                 if (conn) {
830                     hci_shutdown_connection(conn);
831                 }
832             }
833             break;
834 
835         case HCI_EVENT_HARDWARE_ERROR:
836             if(hci_stack->control && hci_stack->control->hw_error){
837                 (*hci_stack->control->hw_error)();
838             }
839             break;
840 
841         case DAEMON_EVENT_HCI_PACKET_SENT:
842             // free packet buffer for asynchronous transport
843             if (hci_transport_synchronous()) break;
844             hci_stack->hci_packet_buffer_reserved = 0;
845             break;
846 
847 #ifdef HAVE_BLE
848         case HCI_EVENT_LE_META:
849             switch (packet[2]) {
850                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
851                     // Connection management
852                     bt_flip_addr(addr, &packet[8]);
853                     log_info("LE Connection_complete (status=%u) %s\n", packet[3], bd_addr_to_str(addr));
854                     // LE connections are auto-accepted, so just create a connection if there isn't one already
855                     conn = connection_for_address(addr);
856                     if (packet[3]){
857                         if (conn){
858                             // outgoing connection failed, remove entry
859                             linked_list_remove(&hci_stack->connections, (linked_item_t *) conn);
860                             btstack_memory_hci_connection_free( conn );
861 
862                         }
863                         // if authentication error, also delete link key
864                         if (packet[3] == 0x05) {
865                             hci_drop_link_key_for_bd_addr(&addr);
866                         }
867                         break;
868                     }
869                     if (!conn){
870                         conn = create_connection_for_addr(addr);
871                     }
872                     if (!conn){
873                         // no memory
874                         break;
875                     }
876 
877                     conn->state = OPEN;
878                     conn->con_handle = READ_BT_16(packet, 4);
879 
880                     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
881 
882                     // restart timer
883                     // run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
884                     // run_loop_add_timer(&conn->timeout);
885 
886                     log_info("New connection: handle %u, %s\n", conn->con_handle, bd_addr_to_str(conn->address));
887 
888                     hci_emit_nr_connections_changed();
889                     break;
890 
891             // printf("LE buffer size: %u, count %u\n", READ_BT_16(packet,6), packet[8]);
892 
893                 default:
894                     break;
895             }
896             break;
897 #endif
898 
899         default:
900             break;
901     }
902 
903     // handle BT initialization
904     if (hci_stack->state == HCI_STATE_INITIALIZING){
905         if (hci_stack->substate % 2){
906             // odd: waiting for event
907             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
908                 // wait for explicit COMMAND COMPLETE on RESET
909                 if (hci_stack->substate > 1 || COMMAND_COMPLETE_EVENT(packet, hci_reset)) {
910                     hci_stack->substate++;
911                 }
912             }
913         }
914     }
915 
916     // help with BT sleep
917     if (hci_stack->state == HCI_STATE_FALLING_ASLEEP
918         && hci_stack->substate == 1
919         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
920         hci_stack->substate++;
921     }
922 
923     hci_stack->packet_handler(HCI_EVENT_PACKET, packet, size);
924 
925 	// execute main loop
926 	hci_run();
927 }
928 
929 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
930     switch (packet_type) {
931         case HCI_EVENT_PACKET:
932             event_handler(packet, size);
933             break;
934         case HCI_ACL_DATA_PACKET:
935             acl_handler(packet, size);
936             break;
937         default:
938             break;
939     }
940 }
941 
942 /** Register HCI packet handlers */
943 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
944     hci_stack->packet_handler = handler;
945 }
946 
947 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t const* remote_device_db){
948 
949 #ifdef HAVE_MALLOC
950     if (!hci_stack) {
951         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
952     }
953 #else
954     hci_stack = &hci_stack_static;
955 #endif
956     memset(hci_stack, 0, sizeof(hci_stack_t));
957 
958     // reference to use transport layer implementation
959     hci_stack->hci_transport = transport;
960 
961     // references to used control implementation
962     hci_stack->control = control;
963 
964     // reference to used config
965     hci_stack->config = config;
966 
967     // no connections yet
968     hci_stack->connections = NULL;
969     hci_stack->discoverable = 0;
970     hci_stack->connectable = 0;
971     hci_stack->bondable = 1;
972 
973     // no pending cmds
974     hci_stack->decline_reason = 0;
975     hci_stack->new_scan_enable_value = 0xff;
976 
977     // higher level handler
978     hci_stack->packet_handler = dummy_handler;
979 
980     // store and open remote device db
981     hci_stack->remote_device_db = remote_device_db;
982     if (hci_stack->remote_device_db) {
983         hci_stack->remote_device_db->open();
984     }
985 
986     // max acl payload size defined in config.h
987     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
988 
989     // register packet handlers with transport
990     transport->register_packet_handler(&packet_handler);
991 
992     hci_stack->state = HCI_STATE_OFF;
993 
994     // class of device
995     hci_stack->class_of_device = 0x007a020c; // Smartphone
996 
997     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
998     hci_stack->ssp_enable = 1;
999     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
1000     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
1001     hci_stack->ssp_auto_accept = 1;
1002 
1003     // LE
1004     hci_stack->adv_addr_type = 0;
1005     memset(hci_stack->adv_address, 0, 6);
1006 }
1007 
1008 void hci_close(){
1009     // close remote device db
1010     if (hci_stack->remote_device_db) {
1011         hci_stack->remote_device_db->close();
1012     }
1013     while (hci_stack->connections) {
1014         hci_shutdown_connection((hci_connection_t *) hci_stack->connections);
1015     }
1016     hci_power_control(HCI_POWER_OFF);
1017 
1018 #ifdef HAVE_MALLOC
1019     free(hci_stack);
1020 #endif
1021     hci_stack = NULL;
1022 }
1023 
1024 void hci_set_class_of_device(uint32_t class_of_device){
1025     hci_stack->class_of_device = class_of_device;
1026 }
1027 
1028 void hci_disable_l2cap_timeout_check(){
1029     disable_l2cap_timeouts = 1;
1030 }
1031 // State-Module-Driver overview
1032 // state                    module  low-level
1033 // HCI_STATE_OFF             off      close
1034 // HCI_STATE_INITIALIZING,   on       open
1035 // HCI_STATE_WORKING,        on       open
1036 // HCI_STATE_HALTING,        on       open
1037 // HCI_STATE_SLEEPING,    off/sleep   close
1038 // HCI_STATE_FALLING_ASLEEP  on       open
1039 
1040 static int hci_power_control_on(void){
1041 
1042     // power on
1043     int err = 0;
1044     if (hci_stack->control && hci_stack->control->on){
1045         err = (*hci_stack->control->on)(hci_stack->config);
1046     }
1047     if (err){
1048         log_error( "POWER_ON failed\n");
1049         hci_emit_hci_open_failed();
1050         return err;
1051     }
1052 
1053     // open low-level device
1054     err = hci_stack->hci_transport->open(hci_stack->config);
1055     if (err){
1056         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
1057         if (hci_stack->control && hci_stack->control->off){
1058             (*hci_stack->control->off)(hci_stack->config);
1059         }
1060         hci_emit_hci_open_failed();
1061         return err;
1062     }
1063     return 0;
1064 }
1065 
1066 static void hci_power_control_off(void){
1067 
1068     log_info("hci_power_control_off\n");
1069 
1070     // close low-level device
1071     hci_stack->hci_transport->close(hci_stack->config);
1072 
1073     log_info("hci_power_control_off - hci_transport closed\n");
1074 
1075     // power off
1076     if (hci_stack->control && hci_stack->control->off){
1077         (*hci_stack->control->off)(hci_stack->config);
1078     }
1079 
1080     log_info("hci_power_control_off - control closed\n");
1081 
1082     hci_stack->state = HCI_STATE_OFF;
1083 }
1084 
1085 static void hci_power_control_sleep(void){
1086 
1087     log_info("hci_power_control_sleep\n");
1088 
1089 #if 0
1090     // don't close serial port during sleep
1091 
1092     // close low-level device
1093     hci_stack->hci_transport->close(hci_stack->config);
1094 #endif
1095 
1096     // sleep mode
1097     if (hci_stack->control && hci_stack->control->sleep){
1098         (*hci_stack->control->sleep)(hci_stack->config);
1099     }
1100 
1101     hci_stack->state = HCI_STATE_SLEEPING;
1102 }
1103 
1104 static int hci_power_control_wake(void){
1105 
1106     log_info("hci_power_control_wake\n");
1107 
1108     // wake on
1109     if (hci_stack->control && hci_stack->control->wake){
1110         (*hci_stack->control->wake)(hci_stack->config);
1111     }
1112 
1113 #if 0
1114     // open low-level device
1115     int err = hci_stack->hci_transport->open(hci_stack->config);
1116     if (err){
1117         log_error( "HCI_INIT failed, turning Bluetooth off again\n");
1118         if (hci_stack->control && hci_stack->control->off){
1119             (*hci_stack->control->off)(hci_stack->config);
1120         }
1121         hci_emit_hci_open_failed();
1122         return err;
1123     }
1124 #endif
1125 
1126     return 0;
1127 }
1128 
1129 
1130 int hci_power_control(HCI_POWER_MODE power_mode){
1131 
1132     log_info("hci_power_control: %u, current mode %u\n", power_mode, hci_stack->state);
1133 
1134     int err = 0;
1135     switch (hci_stack->state){
1136 
1137         case HCI_STATE_OFF:
1138             switch (power_mode){
1139                 case HCI_POWER_ON:
1140                     err = hci_power_control_on();
1141                     if (err) return err;
1142                     // set up state machine
1143                     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1144                     hci_stack->state = HCI_STATE_INITIALIZING;
1145                     hci_stack->substate = 0;
1146                     break;
1147                 case HCI_POWER_OFF:
1148                     // do nothing
1149                     break;
1150                 case HCI_POWER_SLEEP:
1151                     // do nothing (with SLEEP == OFF)
1152                     break;
1153             }
1154             break;
1155 
1156         case HCI_STATE_INITIALIZING:
1157             switch (power_mode){
1158                 case HCI_POWER_ON:
1159                     // do nothing
1160                     break;
1161                 case HCI_POWER_OFF:
1162                     // no connections yet, just turn it off
1163                     hci_power_control_off();
1164                     break;
1165                 case HCI_POWER_SLEEP:
1166                     // no connections yet, just turn it off
1167                     hci_power_control_sleep();
1168                     break;
1169             }
1170             break;
1171 
1172         case HCI_STATE_WORKING:
1173             switch (power_mode){
1174                 case HCI_POWER_ON:
1175                     // do nothing
1176                     break;
1177                 case HCI_POWER_OFF:
1178                     // see hci_run
1179                     hci_stack->state = HCI_STATE_HALTING;
1180                     break;
1181                 case HCI_POWER_SLEEP:
1182                     // see hci_run
1183                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1184                     hci_stack->substate = 0;
1185                     break;
1186             }
1187             break;
1188 
1189         case HCI_STATE_HALTING:
1190             switch (power_mode){
1191                 case HCI_POWER_ON:
1192                     // set up state machine
1193                     hci_stack->state = HCI_STATE_INITIALIZING;
1194                     hci_stack->substate = 0;
1195                     break;
1196                 case HCI_POWER_OFF:
1197                     // do nothing
1198                     break;
1199                 case HCI_POWER_SLEEP:
1200                     // see hci_run
1201                     hci_stack->state = HCI_STATE_FALLING_ASLEEP;
1202                     hci_stack->substate = 0;
1203                     break;
1204             }
1205             break;
1206 
1207         case HCI_STATE_FALLING_ASLEEP:
1208             switch (power_mode){
1209                 case HCI_POWER_ON:
1210 
1211 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1212                     // nothing to do, if H4 supports power management
1213                     if (bt_control_iphone_power_management_enabled()){
1214                         hci_stack->state = HCI_STATE_INITIALIZING;
1215                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1216                         break;
1217                     }
1218 #endif
1219                     // set up state machine
1220                     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1221                     hci_stack->state = HCI_STATE_INITIALIZING;
1222                     hci_stack->substate = 0;
1223                     break;
1224                 case HCI_POWER_OFF:
1225                     // see hci_run
1226                     hci_stack->state = HCI_STATE_HALTING;
1227                     break;
1228                 case HCI_POWER_SLEEP:
1229                     // do nothing
1230                     break;
1231             }
1232             break;
1233 
1234         case HCI_STATE_SLEEPING:
1235             switch (power_mode){
1236                 case HCI_POWER_ON:
1237 
1238 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1239                     // nothing to do, if H4 supports power management
1240                     if (bt_control_iphone_power_management_enabled()){
1241                         hci_stack->state = HCI_STATE_INITIALIZING;
1242                         hci_stack->substate = HCI_INTIALIZING_SUBSTATE_AFTER_SLEEP;
1243                         hci_update_scan_enable();
1244                         break;
1245                     }
1246 #endif
1247                     err = hci_power_control_wake();
1248                     if (err) return err;
1249                     // set up state machine
1250                     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
1251                     hci_stack->state = HCI_STATE_INITIALIZING;
1252                     hci_stack->substate = 0;
1253                     break;
1254                 case HCI_POWER_OFF:
1255                     hci_stack->state = HCI_STATE_HALTING;
1256                     break;
1257                 case HCI_POWER_SLEEP:
1258                     // do nothing
1259                     break;
1260             }
1261             break;
1262     }
1263 
1264     // create internal event
1265 	hci_emit_state();
1266 
1267 	// trigger next/first action
1268 	hci_run();
1269 
1270     return 0;
1271 }
1272 
1273 static void hci_update_scan_enable(void){
1274     // 2 = page scan, 1 = inq scan
1275     hci_stack->new_scan_enable_value  = hci_stack->connectable << 1 | hci_stack->discoverable;
1276     hci_run();
1277 }
1278 
1279 void hci_discoverable_control(uint8_t enable){
1280     if (enable) enable = 1; // normalize argument
1281 
1282     if (hci_stack->discoverable == enable){
1283         hci_emit_discoverable_enabled(hci_stack->discoverable);
1284         return;
1285     }
1286 
1287     hci_stack->discoverable = enable;
1288     hci_update_scan_enable();
1289 }
1290 
1291 void hci_connectable_control(uint8_t enable){
1292     if (enable) enable = 1; // normalize argument
1293 
1294     // don't emit event
1295     if (hci_stack->connectable == enable) return;
1296 
1297     hci_stack->connectable = enable;
1298     hci_update_scan_enable();
1299 }
1300 
1301 bd_addr_t * hci_local_bd_addr(void){
1302     return &hci_stack->local_bd_addr;
1303 }
1304 
1305 void hci_run(){
1306 
1307     hci_connection_t * connection;
1308     linked_item_t * it;
1309 
1310     if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) return;
1311 
1312     // global/non-connection oriented commands
1313 
1314     // decline incoming connections
1315     if (hci_stack->decline_reason){
1316         uint8_t reason = hci_stack->decline_reason;
1317         hci_stack->decline_reason = 0;
1318         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
1319         return;
1320     }
1321 
1322     // send scan enable
1323     if (hci_stack->state == HCI_STATE_WORKING && hci_stack->new_scan_enable_value != 0xff && hci_classic_supported()){
1324         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1325         hci_stack->new_scan_enable_value = 0xff;
1326         return;
1327     }
1328 
1329     // send pending HCI commands
1330     for (it = (linked_item_t *) hci_stack->connections; it ; it = it->next){
1331 
1332         connection = (hci_connection_t *) it;
1333 
1334         if (connection->state == SEND_CREATE_CONNECTION){
1335             log_info("sending hci_create_connection\n");
1336             hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, 1);
1337             return;
1338         }
1339 
1340         if (connection->state == RECEIVED_CONNECTION_REQUEST){
1341             log_info("sending hci_accept_connection_request\n");
1342             connection->state = ACCEPTED_CONNECTION_REQUEST;
1343             hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
1344             return;
1345         }
1346 
1347         if (connection->authentication_flags & HANDLE_LINK_KEY_REQUEST){
1348             log_info("responding to link key request\n");
1349             connectionClearAuthenticationFlags(connection, HANDLE_LINK_KEY_REQUEST);
1350             link_key_t link_key;
1351             link_key_type_t link_key_type;
1352             if ( hci_stack->remote_device_db
1353               && hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)
1354               && gap_security_level_for_link_key_type(link_key_type) >= connection->requested_security_level){
1355                connection->link_key_type = link_key_type;
1356                hci_send_cmd(&hci_link_key_request_reply, connection->address, &link_key);
1357             } else {
1358                hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
1359             }
1360             return;
1361         }
1362 
1363         if (connection->authentication_flags & DENY_PIN_CODE_REQUEST){
1364             log_info("denying to pin request\n");
1365             connectionClearAuthenticationFlags(connection, DENY_PIN_CODE_REQUEST);
1366             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
1367             return;
1368         }
1369 
1370         if (connection->authentication_flags & SEND_IO_CAPABILITIES_REPLY){
1371             connectionClearAuthenticationFlags(connection, SEND_IO_CAPABILITIES_REPLY);
1372             log_info("IO Capability Request received, stack bondable %u, io cap %u", hci_stack->bondable, hci_stack->ssp_io_capability);
1373             if (hci_stack->bondable && (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN)){
1374                 // tweak authentication requirements
1375                 uint8_t authreq = hci_stack->ssp_authentication_requirement;
1376                 if (connection->bonding_flags & BONDING_DEDICATED){
1377                     authreq = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
1378                 }
1379                 if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
1380                     authreq |= 1;
1381                 }
1382                 hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, NULL, authreq);
1383             } else {
1384                 hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
1385             }
1386             return;
1387         }
1388 
1389         if (connection->authentication_flags & SEND_USER_CONFIRM_REPLY){
1390             connectionClearAuthenticationFlags(connection, SEND_USER_CONFIRM_REPLY);
1391             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
1392             return;
1393         }
1394 
1395         if (connection->authentication_flags & SEND_USER_PASSKEY_REPLY){
1396             connectionClearAuthenticationFlags(connection, SEND_USER_PASSKEY_REPLY);
1397             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
1398             return;
1399         }
1400 
1401         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES){
1402             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES;
1403             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
1404             return;
1405         }
1406 
1407         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
1408             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
1409             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x0005);  // authentication failure
1410             return;
1411         }
1412         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
1413             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
1414             hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // authentication done
1415             return;
1416         }
1417         if (connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST){
1418             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
1419             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
1420             return;
1421         }
1422         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
1423             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
1424             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
1425             return;
1426         }
1427     }
1428 
1429     switch (hci_stack->state){
1430         case HCI_STATE_INITIALIZING:
1431             // log_info("hci_init: substate %u\n", hci_stack->substate);
1432             if (hci_stack->substate % 2) {
1433                 // odd: waiting for command completion
1434                 return;
1435             }
1436             switch (hci_stack->substate >> 1){
1437                 case 0: // RESET
1438                     hci_send_cmd(&hci_reset);
1439 
1440                     if (hci_stack->config == 0 || ((hci_uart_config_t *)hci_stack->config)->baudrate_main == 0){
1441                         // skip baud change
1442                         hci_stack->substate = 4; // >> 1 = 2
1443                     }
1444                     break;
1445                 case 1: // SEND BAUD CHANGE
1446                     hci_stack->control->baudrate_cmd(hci_stack->config, ((hci_uart_config_t *)hci_stack->config)->baudrate_main, hci_stack->hci_packet_buffer);
1447                     hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3 + hci_stack->hci_packet_buffer[2]);
1448                     break;
1449                 case 2: // LOCAL BAUD CHANGE
1450                     hci_stack->hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack->config)->baudrate_main);
1451                     hci_stack->substate += 2;
1452                     // break missing here for fall through
1453 
1454                 case 3:
1455                     // Custom initialization
1456                     if (hci_stack->control && hci_stack->control->next_cmd){
1457                         int valid_cmd = (*hci_stack->control->next_cmd)(hci_stack->config, hci_stack->hci_packet_buffer);
1458                         if (valid_cmd){
1459                             int size = 3 + hci_stack->hci_packet_buffer[2];
1460                             hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1461                             hci_stack->substate = 4; // more init commands
1462                             break;
1463                         }
1464                         log_info("hci_run: init script done\n\r");
1465                     }
1466                     // otherwise continue
1467 					hci_send_cmd(&hci_read_bd_addr);
1468 					break;
1469 				case 4:
1470 					hci_send_cmd(&hci_read_buffer_size);
1471 					break;
1472                 case 5:
1473                     hci_send_cmd(&hci_read_local_supported_features);
1474                     break;
1475                 case 6:
1476                     if (hci_le_supported()){
1477                         hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x3FFFFFFF);
1478                     } else {
1479                         // Kensington Bluetoot 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1480                         hci_send_cmd(&hci_set_event_mask,0xffffffff, 0x1FFFFFFF);
1481                     }
1482 
1483                     // skip Classic init commands for LE only chipsets
1484                     if (!hci_classic_supported()){
1485                         if (hci_le_supported()){
1486                             hci_stack->substate = 11 << 1;    // skip all classic command
1487                         } else {
1488                             log_error("Neither BR/EDR nor LE supported");
1489                             hci_stack->substate = 13 << 1;    // skip all
1490                         }
1491                     }
1492                     break;
1493                 case 7:
1494                     if (hci_ssp_supported()){
1495                         hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1496                         break;
1497                     }
1498                     hci_stack->substate += 2;
1499                     // break missing here for fall through
1500 
1501                 case 8:
1502                     // ca. 15 sec
1503                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
1504                     break;
1505                 case 9:
1506                     hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1507                     break;
1508                 case 10:
1509                     if (hci_stack->local_name){
1510                         hci_send_cmd(&hci_write_local_name, hci_stack->local_name);
1511                     } else {
1512                         char hostname[30];
1513 #ifdef EMBEDDED
1514                         // BTstack-11:22:33:44:55:66
1515                         strcpy(hostname, "BTstack ");
1516                         strcat(hostname, bd_addr_to_str(hci_stack->local_bd_addr));
1517                         printf("---> Name %s\n", hostname);
1518 #else
1519                         // hostname for POSIX systems
1520                         gethostname(hostname, 30);
1521                         hostname[29] = '\0';
1522 #endif
1523                         hci_send_cmd(&hci_write_local_name, hostname);
1524                     }
1525                     break;
1526                 case 11:
1527 					hci_send_cmd(&hci_write_scan_enable, (hci_stack->connectable << 1) | hci_stack->discoverable); // page scan
1528                     if (!hci_le_supported()){
1529                         // SKIP LE init for Classic only configuration
1530                         hci_stack->substate = 13 << 1;
1531                     }
1532 					break;
1533 
1534 #ifdef HAVE_BLE
1535                 // LE INIT
1536                 case 12:
1537                     hci_send_cmd(&hci_le_read_buffer_size);
1538                     break;
1539                 case 13:
1540                     // LE Supported Host = 1, Simultaneous Host = 0
1541                     hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1542                     break;
1543 #endif
1544 
1545                 // DONE
1546                 case 14:
1547                     // done.
1548                     hci_stack->state = HCI_STATE_WORKING;
1549                     hci_emit_state();
1550                     break;
1551                 default:
1552                     break;
1553             }
1554             hci_stack->substate++;
1555             break;
1556 
1557         case HCI_STATE_HALTING:
1558 
1559             log_info("HCI_STATE_HALTING\n");
1560             // close all open connections
1561             connection =  (hci_connection_t *) hci_stack->connections;
1562             if (connection){
1563 
1564                 // send disconnect
1565                 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) return;
1566 
1567                 log_info("HCI_STATE_HALTING, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1568                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1569 
1570                 // send disconnected event right away - causes higher layer connections to get closed, too.
1571                 hci_shutdown_connection(connection);
1572                 return;
1573             }
1574             log_info("HCI_STATE_HALTING, calling off\n");
1575 
1576             // switch mode
1577             hci_power_control_off();
1578 
1579             log_info("HCI_STATE_HALTING, emitting state\n");
1580             hci_emit_state();
1581             log_info("HCI_STATE_HALTING, done\n");
1582             break;
1583 
1584         case HCI_STATE_FALLING_ASLEEP:
1585             switch(hci_stack->substate) {
1586                 case 0:
1587                     log_info("HCI_STATE_FALLING_ASLEEP\n");
1588                     // close all open connections
1589                     connection =  (hci_connection_t *) hci_stack->connections;
1590 
1591 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1592                     // don't close connections, if H4 supports power management
1593                     if (bt_control_iphone_power_management_enabled()){
1594                         connection = NULL;
1595                     }
1596 #endif
1597                     if (connection){
1598 
1599                         // send disconnect
1600                         if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) return;
1601 
1602                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u\n", connection, (uint16_t)connection->con_handle);
1603                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
1604 
1605                         // send disconnected event right away - causes higher layer connections to get closed, too.
1606                         hci_shutdown_connection(connection);
1607                         return;
1608                     }
1609 
1610                     if (hci_classic_supported()){
1611                         // disable page and inquiry scan
1612                         if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) return;
1613 
1614                         log_info("HCI_STATE_HALTING, disabling inq scans\n");
1615                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
1616 
1617                         // continue in next sub state
1618                         hci_stack->substate++;
1619                         break;
1620                     }
1621                     // fall through for ble-only chips
1622 
1623                 case 2:
1624                     log_info("HCI_STATE_HALTING, calling sleep\n");
1625 #if defined(USE_POWERMANAGEMENT) && defined(USE_BLUETOOL)
1626                     // don't actually go to sleep, if H4 supports power management
1627                     if (bt_control_iphone_power_management_enabled()){
1628                         // SLEEP MODE reached
1629                         hci_stack->state = HCI_STATE_SLEEPING;
1630                         hci_emit_state();
1631                         break;
1632                     }
1633 #endif
1634                     // switch mode
1635                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
1636                     hci_emit_state();
1637                     break;
1638 
1639                 default:
1640                     break;
1641             }
1642             break;
1643 
1644         default:
1645             break;
1646     }
1647 }
1648 
1649 int hci_send_cmd_packet(uint8_t *packet, int size){
1650     bd_addr_t addr;
1651     hci_connection_t * conn;
1652     // house-keeping
1653 
1654     // create_connection?
1655     if (IS_COMMAND(packet, hci_create_connection)){
1656         bt_flip_addr(addr, &packet[3]);
1657         log_info("Create_connection to %s\n", bd_addr_to_str(addr));
1658 
1659         conn = connection_for_address(addr);
1660         if (!conn){
1661             conn = create_connection_for_addr(addr);
1662             if (!conn){
1663                 // notify client that alloc failed
1664                 hci_emit_connection_complete(conn, BTSTACK_MEMORY_ALLOC_FAILED);
1665                 return 0; // don't sent packet to controller
1666             }
1667             conn->state = SEND_CREATE_CONNECTION;
1668         }
1669         log_info("conn state %u", conn->state);
1670         switch (conn->state){
1671             // if connection active exists
1672             case OPEN:
1673                 // and OPEN, emit connection complete command, don't send to controller
1674                 hci_emit_connection_complete(conn, 0);
1675                 return 0;
1676             case SEND_CREATE_CONNECTION:
1677                 // connection created by hci, e.g. dedicated bonding
1678                 break;
1679             default:
1680                 // otherwise, just ignore as it is already in the open process
1681                 return 0;
1682         }
1683         conn->state = SENT_CREATE_CONNECTION;
1684     }
1685 
1686     if (IS_COMMAND(packet, hci_link_key_request_reply)){
1687         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
1688     }
1689     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
1690         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
1691     }
1692 
1693     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
1694         if (hci_stack->remote_device_db){
1695             bt_flip_addr(addr, &packet[3]);
1696             hci_stack->remote_device_db->delete_link_key(&addr);
1697         }
1698     }
1699 
1700     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)
1701     ||  IS_COMMAND(packet, hci_pin_code_request_reply)){
1702         bt_flip_addr(addr, &packet[3]);
1703         conn = connection_for_address(addr);
1704         if (conn){
1705             connectionClearAuthenticationFlags(conn, LEGACY_PAIRING_ACTIVE);
1706         }
1707     }
1708 
1709     if (IS_COMMAND(packet, hci_user_confirmation_request_negative_reply)
1710     ||  IS_COMMAND(packet, hci_user_confirmation_request_reply)
1711     ||  IS_COMMAND(packet, hci_user_passkey_request_negative_reply)
1712     ||  IS_COMMAND(packet, hci_user_passkey_request_reply)) {
1713         bt_flip_addr(addr, &packet[3]);
1714         conn = connection_for_address(addr);
1715         if (conn){
1716             connectionClearAuthenticationFlags(conn, SSP_PAIRING_ACTIVE);
1717         }
1718     }
1719 
1720 #ifdef HAVE_BLE
1721     if (IS_COMMAND(packet, hci_le_set_advertising_parameters)){
1722         hci_stack->adv_addr_type = packet[8];
1723     }
1724     if (IS_COMMAND(packet, hci_le_set_random_address)){
1725         bt_flip_addr(hci_stack->adv_address, &packet[3]);
1726     }
1727 #endif
1728 
1729     hci_stack->num_cmd_packets--;
1730     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
1731 
1732     // free packet buffer for synchronous transport implementations
1733     if (hci_transport_synchronous() && (packet == hci_stack->hci_packet_buffer)){
1734         hci_stack->hci_packet_buffer_reserved = 0;
1735     }
1736 
1737     return err;
1738 }
1739 
1740 // disconnect because of security block
1741 void hci_disconnect_security_block(hci_con_handle_t con_handle){
1742     hci_connection_t * connection = hci_connection_for_handle(con_handle);
1743     if (!connection) return;
1744     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
1745 }
1746 
1747 
1748 // Configure Secure Simple Pairing
1749 
1750 // enable will enable SSP during init
1751 void hci_ssp_set_enable(int enable){
1752     hci_stack->ssp_enable = enable;
1753 }
1754 
1755 int hci_local_ssp_activated(){
1756     return hci_ssp_supported() && hci_stack->ssp_enable;
1757 }
1758 
1759 // if set, BTstack will respond to io capability request using authentication requirement
1760 void hci_ssp_set_io_capability(int io_capability){
1761     hci_stack->ssp_io_capability = io_capability;
1762 }
1763 void hci_ssp_set_authentication_requirement(int authentication_requirement){
1764     hci_stack->ssp_authentication_requirement = authentication_requirement;
1765 }
1766 
1767 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
1768 void hci_ssp_set_auto_accept(int auto_accept){
1769     hci_stack->ssp_auto_accept = auto_accept;
1770 }
1771 
1772 /**
1773  * pre: numcmds >= 0 - it's allowed to send a command to the controller
1774  */
1775 int hci_send_cmd(const hci_cmd_t *cmd, ...){
1776     va_list argptr;
1777     va_start(argptr, cmd);
1778     uint16_t size = hci_create_cmd_internal(hci_stack->hci_packet_buffer, cmd, argptr);
1779     va_end(argptr);
1780     return hci_send_cmd_packet(hci_stack->hci_packet_buffer, size);
1781 }
1782 
1783 // Create various non-HCI events.
1784 // TODO: generalize, use table similar to hci_create_command
1785 
1786 void hci_emit_state(){
1787     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
1788     uint8_t event[3];
1789     event[0] = BTSTACK_EVENT_STATE;
1790     event[1] = sizeof(event) - 2;
1791     event[2] = hci_stack->state;
1792     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1793     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1794 }
1795 
1796 void hci_emit_connection_complete(hci_connection_t *conn, uint8_t status){
1797     uint8_t event[13];
1798     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
1799     event[1] = sizeof(event) - 2;
1800     event[2] = status;
1801     bt_store_16(event, 3, conn->con_handle);
1802     bt_flip_addr(&event[5], conn->address);
1803     event[11] = 1; // ACL connection
1804     event[12] = 0; // encryption disabled
1805     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1806     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1807 }
1808 
1809 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
1810     uint8_t event[6];
1811     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
1812     event[1] = sizeof(event) - 2;
1813     event[2] = 0; // status = OK
1814     bt_store_16(event, 3, handle);
1815     event[5] = reason;
1816     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1817     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1818 }
1819 
1820 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
1821     if (disable_l2cap_timeouts) return;
1822     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
1823     uint8_t event[4];
1824     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
1825     event[1] = sizeof(event) - 2;
1826     bt_store_16(event, 2, conn->con_handle);
1827     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1828     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1829 }
1830 
1831 void hci_emit_nr_connections_changed(){
1832     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
1833     uint8_t event[3];
1834     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
1835     event[1] = sizeof(event) - 2;
1836     event[2] = nr_hci_connections();
1837     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1838     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1839 }
1840 
1841 void hci_emit_hci_open_failed(){
1842     log_info("BTSTACK_EVENT_POWERON_FAILED");
1843     uint8_t event[2];
1844     event[0] = BTSTACK_EVENT_POWERON_FAILED;
1845     event[1] = sizeof(event) - 2;
1846     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1847     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1848 }
1849 
1850 #ifndef EMBEDDED
1851 void hci_emit_btstack_version() {
1852     log_info("BTSTACK_EVENT_VERSION %u.%u", BTSTACK_MAJOR, BTSTACK_MINOR);
1853     uint8_t event[6];
1854     event[0] = BTSTACK_EVENT_VERSION;
1855     event[1] = sizeof(event) - 2;
1856     event[2] = BTSTACK_MAJOR;
1857     event[3] = BTSTACK_MINOR;
1858     bt_store_16(event, 4, BTSTACK_REVISION);
1859     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1860     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1861 }
1862 #endif
1863 
1864 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
1865     log_info("BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED %u", enabled);
1866     uint8_t event[3];
1867     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
1868     event[1] = sizeof(event) - 2;
1869     event[2] = enabled;
1870     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1871     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1872 }
1873 
1874 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
1875     uint8_t event[2+1+6+248+1]; // +1 for \0 in log_info
1876     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
1877     event[1] = sizeof(event) - 2 - 1;
1878     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
1879     bt_flip_addr(&event[3], *addr);
1880     memcpy(&event[9], name, 248);
1881 
1882     event[9+248] = 0;   // assert \0 for log_info
1883     log_info("BTSTACK_EVENT_REMOTE_NAME_CACHED %s = '%s'", bd_addr_to_str(*addr), &event[9]);
1884 
1885     hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)-1);
1886     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event)-1);
1887 }
1888 
1889 void hci_emit_discoverable_enabled(uint8_t enabled){
1890     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
1891     uint8_t event[3];
1892     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
1893     event[1] = sizeof(event) - 2;
1894     event[2] = enabled;
1895     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1896     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1897 }
1898 
1899 void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
1900     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
1901     uint8_t event[5];
1902     int pos = 0;
1903     event[pos++] = GAP_SECURITY_LEVEL;
1904     event[pos++] = sizeof(event) - 2;
1905     bt_store_16(event, 2, con_handle);
1906     pos += 2;
1907     event[pos++] = level;
1908     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1909     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1910 }
1911 
1912 void hci_emit_dedicated_bonding_result(hci_connection_t * connection, uint8_t status){
1913     log_info("hci_emit_dedicated_bonding_result %u ", status);
1914     uint8_t event[9];
1915     int pos = 0;
1916     event[pos++] = GAP_DEDICATED_BONDING_COMPLETED;
1917     event[pos++] = sizeof(event) - 2;
1918     event[pos++] = status;
1919     bt_flip_addr( * (bd_addr_t *) &event[pos], connection->address);
1920     pos += 6;
1921     hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event));
1922     hci_stack->packet_handler(HCI_EVENT_PACKET, event, sizeof(event));
1923 }
1924 
1925 // query if remote side supports SSP
1926 int hci_remote_ssp_supported(hci_con_handle_t con_handle){
1927     hci_connection_t * connection = hci_connection_for_handle(con_handle);
1928     if (!connection) return 0;
1929     return (connection->bonding_flags & BONDING_REMOTE_SUPPORTS_SSP) ? 1 : 0;
1930 }
1931 
1932 int hci_ssp_supported_on_both_sides(hci_con_handle_t handle){
1933     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
1934 }
1935 
1936 // GAP API
1937 /**
1938  * @bbrief enable/disable bonding. default is enabled
1939  * @praram enabled
1940  */
1941 void gap_set_bondable_mode(int enable){
1942     hci_stack->bondable = enable ? 1 : 0;
1943 }
1944 
1945 /**
1946  * @brief map link keys to security levels
1947  */
1948 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
1949     switch (link_key_type){
1950         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
1951             return LEVEL_4;
1952         case COMBINATION_KEY:
1953         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
1954             return LEVEL_3;
1955         default:
1956             return LEVEL_2;
1957     }
1958 }
1959 
1960 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
1961     if (!connection) return LEVEL_0;
1962     if ((connection->authentication_flags & CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
1963     return gap_security_level_for_link_key_type(connection->link_key_type);
1964 }
1965 
1966 
1967 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
1968     printf("gap_mitm_protection_required_for_security_level %u\n", level);
1969     return level > LEVEL_2;
1970 }
1971 
1972 /**
1973  * @brief get current security level
1974  */
1975 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
1976     hci_connection_t * connection = hci_connection_for_handle(con_handle);
1977     if (!connection) return LEVEL_0;
1978     return gap_security_level_for_connection(connection);
1979 }
1980 
1981 /**
1982  * @brief request connection to device to
1983  * @result GAP_AUTHENTICATION_RESULT
1984  */
1985 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
1986     hci_connection_t * connection = hci_connection_for_handle(con_handle);
1987     if (!connection){
1988         hci_emit_security_level(con_handle, LEVEL_0);
1989         return;
1990     }
1991     gap_security_level_t current_level = gap_security_level(con_handle);
1992     log_info("gap_request_security_level %u, current level %u", requested_level, current_level);
1993     if (current_level >= requested_level){
1994         hci_emit_security_level(con_handle, current_level);
1995         return;
1996     }
1997 
1998     connection->requested_security_level = requested_level;
1999 
2000     // would enabling ecnryption suffice (>= LEVEL_2)?
2001     if (hci_stack->remote_device_db){
2002         link_key_type_t link_key_type;
2003         link_key_t      link_key;
2004         if (hci_stack->remote_device_db->get_link_key( &connection->address, &link_key, &link_key_type)){
2005             if (gap_security_level_for_link_key_type(link_key_type) >= requested_level){
2006                 connection->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
2007                 return;
2008             }
2009         }
2010     }
2011 
2012     // try to authenticate connection
2013     connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2014     hci_run();
2015 }
2016 
2017 /**
2018  * @brief start dedicated bonding with device. disconnect after bonding
2019  * @param device
2020  * @param request MITM protection
2021  * @result GAP_DEDICATED_BONDING_COMPLETE
2022  */
2023 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
2024 
2025     // create connection state machine
2026     hci_connection_t * connection = create_connection_for_addr(device);
2027 
2028     if (!connection){
2029         return BTSTACK_MEMORY_ALLOC_FAILED;
2030     }
2031 
2032     // delete linkn key
2033     hci_drop_link_key_for_bd_addr( (bd_addr_t *) &device);
2034 
2035     // configure LEVEL_2/3, dedicated bonding
2036     connection->state = SEND_CREATE_CONNECTION;
2037     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
2038     printf("gap_dedicated_bonding, mitm %u -> level %u\n", mitm_protection_required, connection->requested_security_level);
2039     connection->bonding_flags = BONDING_DEDICATED;
2040 
2041     // wait for GAP Security Result and send GAP Dedicated Bonding complete
2042 
2043     // handle: connnection failure (connection complete != ok)
2044     // handle: authentication failure
2045     // handle: disconnect on done
2046 
2047     hci_run();
2048 
2049     return 0;
2050 }
2051 
2052 void gap_set_local_name(const char * local_name){
2053     hci_stack->local_name = local_name;
2054 }
2055 
2056 
2057