xref: /btstack/src/hci.c (revision b2f09bc060014aabaaf7daecd3898362e62785d0)
1 /*
2  * Copyright (C) 2009 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  *
17  * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
21  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
24  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
27  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  */
31 
32 /*
33  *  hci.c
34  *
35  *  Created by Matthias Ringwald on 4/29/09.
36  *
37  */
38 
39 #include "hci.h"
40 
41 #include <stdarg.h>
42 #include <string.h>
43 #include <stdio.h>
44 
45 #ifndef EMBEDDED
46 #include <unistd.h> // gethostbyname
47 #endif
48 
49 #include "debug.h"
50 #include "hci_dump.h"
51 
52 #include "../include/btstack/hci_cmds.h"
53 #include "../include/btstack/version.h"
54 
55 // temp
56 #include "l2cap.h"
57 
58 #define HCI_CONNECTION_TIMEOUT_MS 10000
59 
60 // the STACK is here
61 static hci_stack_t       hci_stack;
62 
63 /**
64  * get connection for a given handle
65  *
66  * @return connection OR NULL, if not found
67  */
68 hci_connection_t * connection_for_handle(hci_con_handle_t con_handle){
69     linked_item_t *it;
70     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
71         if ( ((hci_connection_t *) it)->con_handle == con_handle){
72             return (hci_connection_t *) it;
73         }
74     }
75     return NULL;
76 }
77 
78 static void hci_connection_timeout_handler(timer_source_t *timer){
79 #ifdef HAVE_TIME
80     hci_connection_t * connection = linked_item_get_user(&timer->item);
81     struct timeval tv;
82     gettimeofday(&tv, NULL);
83     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
84         // connections might be timed out
85         hci_emit_l2cap_check_timeout(connection);
86         run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
87     } else {
88         // next timeout check at
89         timer->timeout.tv_sec = connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000;
90     }
91     run_loop_add_timer(timer);
92 #endif
93 }
94 
95 static void hci_connection_timestamp(hci_connection_t *connection){
96 #ifdef HAVE_TIME
97     gettimeofday(&connection->timestamp, NULL);
98 #endif
99 }
100 
101 /**
102  * create connection for given address
103  *
104  * @return connection OR NULL, if not found
105  */
106 static hci_connection_t * create_connection_for_addr(bd_addr_t addr){
107     hci_connection_t * conn = malloc( sizeof(hci_connection_t) );
108     if (!conn) return NULL;
109     BD_ADDR_COPY(conn->address, addr);
110     conn->con_handle = 0xffff;
111     conn->authentication_flags = 0;
112 #ifdef HAVE_TIME
113     linked_item_set_user(&conn->timeout.item, conn);
114     conn->timeout.process = hci_connection_timeout_handler;
115     hci_connection_timestamp(conn);
116 #endif
117     conn->acl_recombination_length = 0;
118     conn->acl_recombination_pos = 0;
119     conn->num_acl_packets_sent = 0;
120     linked_list_add(&hci_stack.connections, (linked_item_t *) conn);
121     return conn;
122 }
123 
124 /**
125  * get connection for given address
126  *
127  * @return connection OR NULL, if not found
128  */
129 static hci_connection_t * connection_for_address(bd_addr_t address){
130     linked_item_t *it;
131     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
132         if ( ! BD_ADDR_CMP( ((hci_connection_t *) it)->address, address) ){
133             return (hci_connection_t *) it;
134         }
135     }
136     return NULL;
137 }
138 
139 /**
140  * add authentication flags and reset timer
141  */
142 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
143     bd_addr_t addr;
144     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
145     hci_connection_t * conn = connection_for_address(addr);
146     if (conn) {
147         conn->authentication_flags |= flags;
148         hci_connection_timestamp(conn);
149     }
150 }
151 
152 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
153     hci_connection_t * conn = connection_for_handle(handle);
154     if (!conn) return 0;
155     if (!conn->authentication_flags) return 0;
156     if (conn->authentication_flags & SENT_LINK_KEY_REPLY) return 0;
157     if (conn->authentication_flags & RECV_LINK_KEY_NOTIFICATION) return 0;
158     return 1;
159 }
160 
161 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
162     if (hci_stack.remote_device_db) {
163         hci_stack.remote_device_db->delete_link_key(addr);
164     }
165 }
166 
167 
168 /**
169  * count connections
170  */
171 static int nr_hci_connections(void){
172     int count = 0;
173     linked_item_t *it;
174     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next, count++);
175     return count;
176 }
177 
178 /**
179  * Dummy handler called by HCI
180  */
181 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
182 }
183 
184 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
185     hci_connection_t * connection = connection_for_handle(handle);
186     if (!connection) {
187         log_err("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
188         return 0;
189     }
190     return connection->num_acl_packets_sent;
191 }
192 
193 uint8_t hci_number_free_acl_slots(){
194     uint8_t free_slots = hci_stack.total_num_acl_packets;
195     linked_item_t *it;
196     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
197         hci_connection_t * connection = (hci_connection_t *) it;
198         if (free_slots < connection->num_acl_packets_sent) {
199             log_err("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
200             return 0;
201         }
202         free_slots -= connection->num_acl_packets_sent;
203     }
204     return free_slots;
205 }
206 
207 uint16_t hci_max_acl_data_packet_length(){
208     return hci_stack.acl_data_packet_length;
209 }
210 
211 int hci_send_acl_packet(uint8_t *packet, int size){
212 
213     // check for free places on BT module
214     if (!hci_number_free_acl_slots()) return BTSTACK_ACL_BUFFERS_FULL;
215 
216     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
217     hci_connection_t *connection = connection_for_handle( con_handle);
218     if (!connection) return 0;
219     hci_connection_timestamp(connection);
220 
221     // count packet
222     connection->num_acl_packets_sent++;
223     // log_dbg("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
224 
225     // send packet - ignore errors
226     hci_stack.hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
227 
228     return 0;
229 }
230 
231 static void acl_handler(uint8_t *packet, int size){
232 
233     // get info
234     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
235     hci_connection_t *conn      = connection_for_handle(con_handle);
236     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
237     uint16_t acl_length         = READ_ACL_LENGTH(packet);
238 
239     // ignore non-registered handle
240     if (!conn){
241         log_err( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
242         return;
243     }
244 
245     // update idle timestamp
246     hci_connection_timestamp(conn);
247 
248     // handle different packet types
249     switch (acl_flags & 0x03) {
250 
251         case 0x01: // continuation fragment
252 
253             // sanity check
254             if (conn->acl_recombination_pos == 0) {
255                 log_err( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
256                 return;
257             }
258 
259             // append fragment payload (header already stored)
260             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
261             conn->acl_recombination_pos += acl_length;
262 
263             // log_err( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n",
264             //        acl_length, connection->acl_recombination_pos, connection->acl_recombination_length);
265 
266             // forward complete L2CAP packet if complete.
267             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
268 
269                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
270                 // reset recombination buffer
271                 conn->acl_recombination_length = 0;
272                 conn->acl_recombination_pos = 0;
273             }
274             break;
275 
276         case 0x02: { // first fragment
277 
278             // sanity check
279             if (conn->acl_recombination_pos) {
280                 log_err( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
281                 return;
282             }
283 
284             // peek into L2CAP packet!
285             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
286 
287             // compare fragment size to L2CAP packet size
288             if (acl_length >= l2cap_length + 4){
289 
290                 // forward fragment as L2CAP packet
291                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
292 
293             } else {
294                 // store first fragment and tweak acl length for complete package
295                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
296                 conn->acl_recombination_pos    = acl_length + 4;
297                 conn->acl_recombination_length = l2cap_length;
298                 bt_store_16(conn->acl_recombination_buffer, 2, acl_length +4);
299                 // log_err( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
300             }
301             break;
302 
303         }
304         default:
305             log_err( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
306             return;
307     }
308 
309     // execute main loop
310     hci_run();
311 }
312 
313 static void hci_shutdown_connection(hci_connection_t *conn){
314     log_dbg("Connection closed: handle %u, ", conn->con_handle);
315     print_bd_addr( conn->address );
316     log_dbg("\n");
317 
318     // cancel all l2cap connections
319     hci_emit_disconnection_complete(conn->con_handle, 0x16);    // terminated by local host
320 
321 #ifdef HAVE_TIME
322     run_loop_remove_timer(&conn->timeout);
323 #endif
324     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
325     free( conn );
326 
327     // now it's gone
328     hci_emit_nr_connections_changed();
329 }
330 
331 // avoid huge local variables
332 static device_name_t device_name;
333 static void event_handler(uint8_t *packet, int size){
334     bd_addr_t addr;
335     hci_con_handle_t handle;
336     hci_connection_t * conn;
337     int i;
338     link_key_t link_key;
339 
340     switch (packet[0]) {
341 
342         case HCI_EVENT_COMMAND_COMPLETE:
343             // get num cmd packets
344             // log_dbg("HCI_EVENT_COMMAND_COMPLETE cmds old %u - new %u\n", hci_stack.num_cmd_packets, packet[2]);
345             hci_stack.num_cmd_packets = packet[2];
346 
347             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
348                 // from offset 5
349                 // status
350                 // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
351                 hci_stack.acl_data_packet_length = READ_BT_16(packet, 6);
352                 // ignore: SCO data packet len (8)
353                 hci_stack.total_num_acl_packets  = packet[9];
354                 // ignore: total num SCO packets
355                 if (hci_stack.state == HCI_STATE_INITIALIZING){
356                     log_dbg("hci_read_buffer_size: size %u, count %u\n", hci_stack.acl_data_packet_length, hci_stack.total_num_acl_packets);
357                 }
358             }
359             if (COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
360                 hci_emit_discoverable_enabled(hci_stack.discoverable);
361             }
362             break;
363 
364         case HCI_EVENT_COMMAND_STATUS:
365             // get num cmd packets
366             // log_dbg("HCI_EVENT_COMMAND_STATUS cmds - old %u - new %u\n", hci_stack.num_cmd_packets, packet[3]);
367             hci_stack.num_cmd_packets = packet[3];
368             break;
369 
370         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
371             for (i=0; i<packet[2];i++){
372                 handle = READ_BT_16(packet, 3 + 2*i);
373                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
374                 conn = connection_for_handle(handle);
375                 if (!conn){
376                     log_err("hci_number_completed_packet lists unused con handle %u\n", handle);
377                     continue;
378                 }
379                 conn->num_acl_packets_sent -= num_packets;
380                 // log_dbg("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
381             }
382             break;
383 
384         case HCI_EVENT_CONNECTION_REQUEST:
385             bt_flip_addr(addr, &packet[2]);
386             // TODO: eval COD 8-10
387             uint8_t link_type = packet[11];
388             log_dbg("Connection_incoming: "); print_bd_addr(addr); log_dbg(", type %u\n", link_type);
389             if (link_type == 1) { // ACL
390                 conn = connection_for_address(addr);
391                 if (!conn) {
392                     conn = create_connection_for_addr(addr);
393                 }
394                 // TODO: check for malloc failure
395                 conn->state = ACCEPTED_CONNECTION_REQUEST;
396                 hci_send_cmd(&hci_accept_connection_request, addr, 1);
397             } else {
398                 // TODO: decline request
399             }
400             break;
401 
402         case HCI_EVENT_CONNECTION_COMPLETE:
403             // Connection management
404             bt_flip_addr(addr, &packet[5]);
405             log_dbg("Connection_complete (status=%u)", packet[2]); print_bd_addr(addr); log_dbg("\n");
406             conn = connection_for_address(addr);
407             if (conn) {
408                 if (!packet[2]){
409                     conn->state = OPEN;
410                     conn->con_handle = READ_BT_16(packet, 3);
411 
412 #ifdef HAVE_TIME
413                     gettimeofday(&conn->timestamp, NULL);
414                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
415                     run_loop_add_timer(&conn->timeout);
416 #endif
417                     log_dbg("New connection: handle %u, ", conn->con_handle);
418                     print_bd_addr( conn->address );
419                     log_dbg("\n");
420 
421                     hci_emit_nr_connections_changed();
422                 } else {
423                     // connection failed, remove entry
424                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
425                     free( conn );
426 
427                     // if authentication error, also delete link key
428                     if (packet[2] == 0x05) {
429                         hci_drop_link_key_for_bd_addr(&addr);
430                     }
431                 }
432             }
433             break;
434 
435         case HCI_EVENT_LINK_KEY_REQUEST:
436             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
437             if (!hci_stack.remote_device_db) break;
438             bt_flip_addr(addr, &packet[2]);
439             if ( hci_stack.remote_device_db->get_link_key( &addr, &link_key)){
440                 hci_send_cmd(&hci_link_key_request_reply, &addr, &link_key);
441             } else {
442                 hci_send_cmd(&hci_link_key_request_negative_reply, &addr);
443             }
444             // request already answered
445             return;
446 
447         case HCI_EVENT_LINK_KEY_NOTIFICATION:
448             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_NOTIFICATION);
449             if (!hci_stack.remote_device_db) break;
450             bt_flip_addr(addr, &packet[2]);
451             hci_stack.remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8]);
452             // still forward event to allow dismiss of pairing dialog
453             break;
454 
455         case HCI_EVENT_PIN_CODE_REQUEST:
456             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_PIN_CODE_REQUEST);
457             break;
458 
459         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
460             if (!hci_stack.remote_device_db) break;
461             if (packet[2]) break; // status not ok
462             bt_flip_addr(addr, &packet[3]);
463             // fix for invalid remote names - terminate on 0xff
464             for (i=0; i<248;i++){
465                 if (packet[9+i] == 0xff){
466                     packet[9+i] = 0;
467                     break;
468                 }
469             }
470             bzero(&device_name, sizeof(device_name_t));
471             strncpy((char*) device_name, (char*) &packet[9], 248);
472             hci_stack.remote_device_db->put_name(&addr, &device_name);
473             break;
474 
475         case HCI_EVENT_INQUIRY_RESULT:
476         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
477             if (!hci_stack.remote_device_db) break;
478             // first send inq result packet
479             hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
480             // then send cached remote names
481             for (i=0; i<packet[2];i++){
482                 bt_flip_addr(addr, &packet[3+i*6]);
483                 if (hci_stack.remote_device_db->get_name(&addr, &device_name)){
484                     hci_emit_remote_name_cached(&addr, &device_name);
485                 }
486             }
487             return;
488 
489         case HCI_EVENT_DISCONNECTION_COMPLETE:
490             if (!packet[2]){
491                 handle = READ_BT_16(packet, 3);
492                 hci_connection_t * conn = connection_for_handle(handle);
493                 if (conn) {
494                     hci_shutdown_connection(conn);
495                 }
496             }
497             break;
498 
499         case HCI_EVENT_HARDWARE_ERROR:
500             if(hci_stack.control->hw_error){
501                 (*hci_stack.control->hw_error)();
502             }
503             break;
504 
505         default:
506             break;
507     }
508 
509     // handle BT initialization
510     if (hci_stack.state == HCI_STATE_INITIALIZING){
511         // handle H4 synchronization loss on restart
512         // if (hci_stack.substate == 1 && packet[0] == HCI_EVENT_HARDWARE_ERROR){
513         //    hci_stack.substate = 0;
514         // }
515         // handle normal init sequence
516         if (hci_stack.substate % 2){
517             // odd: waiting for event
518             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
519                 hci_stack.substate++;
520             }
521         }
522     }
523 
524     // help with BT sleep
525     if (hci_stack.state == HCI_STATE_FALLING_ASLEEP
526         && hci_stack.substate == 1
527         && COMMAND_COMPLETE_EVENT(packet, hci_write_scan_enable)){
528         hci_stack.substate++;
529     }
530 
531     hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
532 
533 	// execute main loop
534 	hci_run();
535 }
536 
537 void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
538     switch (packet_type) {
539         case HCI_EVENT_PACKET:
540             event_handler(packet, size);
541             break;
542         case HCI_ACL_DATA_PACKET:
543             acl_handler(packet, size);
544             break;
545         default:
546             break;
547     }
548 }
549 
550 /** Register HCI packet handlers */
551 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
552     hci_stack.packet_handler = handler;
553 }
554 
555 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t * remote_device_db){
556 
557     // reference to use transport layer implementation
558     hci_stack.hci_transport = transport;
559 
560     // references to used control implementation
561     hci_stack.control = control;
562 
563     // reference to used config
564     hci_stack.config = config;
565 
566     // no connections yet
567     hci_stack.connections = NULL;
568     hci_stack.discoverable = 0;
569 
570     // empty cmd buffer
571     hci_stack.hci_cmd_buffer = malloc(3+255);
572 
573     // higher level handler
574     hci_stack.packet_handler = dummy_handler;
575 
576     // store and open remote device db
577     hci_stack.remote_device_db = remote_device_db;
578     if (hci_stack.remote_device_db) {
579         hci_stack.remote_device_db->open();
580     }
581 
582     // register packet handlers with transport
583     transport->register_packet_handler(&packet_handler);
584 }
585 
586 void hci_close(){
587     // close remote device db
588     if (hci_stack.remote_device_db) {
589         hci_stack.remote_device_db->close();
590     }
591 }
592 
593 // State-Module-Driver overview
594 // state                    module  low-level
595 // HCI_STATE_OFF             off      close
596 // HCI_STATE_INITIALIZING,   on       open
597 // HCI_STATE_WORKING,        on       open
598 // HCI_STATE_HALTING,        on       open
599 // HCI_STATE_SLEEPING,    off/sleep   close
600 // HCI_STATE_FALLING_ASLEEP  on       open
601 
602 static int hci_power_control_on(void){
603 
604     // power on
605     int err = 0;
606     if (hci_stack.control && hci_stack.control->on){
607         err = (*hci_stack.control->on)(hci_stack.config);
608     }
609     if (err){
610         log_err( "POWER_ON failed\n");
611         hci_emit_hci_open_failed();
612         return err;
613     }
614 
615     // open low-level device
616     err = hci_stack.hci_transport->open(hci_stack.config);
617     if (err){
618         log_err( "HCI_INIT failed, turning Bluetooth off again\n");
619         if (hci_stack.control && hci_stack.control->off){
620             (*hci_stack.control->off)(hci_stack.config);
621         }
622         hci_emit_hci_open_failed();
623         return err;
624     }
625     return 0;
626 }
627 
628 static void hci_power_control_off(void){
629 
630     log_dbg("hci_power_control_off\n");
631 
632     // close low-level device
633     hci_stack.hci_transport->close(hci_stack.config);
634 
635     log_dbg("hci_power_control_off - hci_transport closed\n");
636 
637     // power off
638     if (hci_stack.control && hci_stack.control->off){
639         (*hci_stack.control->off)(hci_stack.config);
640     }
641 
642     log_dbg("hci_power_control_off - control closed\n");
643 
644     hci_stack.state = HCI_STATE_OFF;
645 }
646 
647 static void hci_power_control_sleep(void){
648 
649     log_dbg("hci_power_control_sleep\n");
650 
651 #if 0
652     // don't close serial port during sleep
653 
654     // close low-level device
655     hci_stack.hci_transport->close(hci_stack.config);
656 #endif
657 
658     // sleep mode
659     if (hci_stack.control && hci_stack.control->sleep){
660         (*hci_stack.control->sleep)(hci_stack.config);
661     }
662 
663     hci_stack.state = HCI_STATE_SLEEPING;
664 }
665 
666 static int hci_power_control_wake(void){
667 
668     log_dbg("hci_power_control_wake\n");
669 
670     // wake on
671     if (hci_stack.control && hci_stack.control->wake){
672         (*hci_stack.control->wake)(hci_stack.config);
673     }
674 
675 #if 0
676     // open low-level device
677     int err = hci_stack.hci_transport->open(hci_stack.config);
678     if (err){
679         log_err( "HCI_INIT failed, turning Bluetooth off again\n");
680         if (hci_stack.control && hci_stack.control->off){
681             (*hci_stack.control->off)(hci_stack.config);
682         }
683         hci_emit_hci_open_failed();
684         return err;
685     }
686 #endif
687 
688     return 0;
689 }
690 
691 
692 int hci_power_control(HCI_POWER_MODE power_mode){
693 
694     log_dbg("hci_power_control: %u, current mode %u\n", power_mode, hci_stack.state);
695 
696     int err = 0;
697     switch (hci_stack.state){
698 
699         case HCI_STATE_OFF:
700             switch (power_mode){
701                 case HCI_POWER_ON:
702                     err = hci_power_control_on();
703                     if (err) return err;
704                     // set up state machine
705                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
706                     hci_stack.state = HCI_STATE_INITIALIZING;
707                     hci_stack.substate = 0;
708                     break;
709                 case HCI_POWER_OFF:
710                     // do nothing
711                     break;
712                 case HCI_POWER_SLEEP:
713                     // do nothing (with SLEEP == OFF)
714                     break;
715             }
716             break;
717 
718         case HCI_STATE_INITIALIZING:
719             switch (power_mode){
720                 case HCI_POWER_ON:
721                     // do nothing
722                     break;
723                 case HCI_POWER_OFF:
724                     // no connections yet, just turn it off
725                     hci_power_control_off();
726                     break;
727                 case HCI_POWER_SLEEP:
728                     // no connections yet, just turn it off
729                     hci_power_control_sleep();
730                     break;
731             }
732             break;
733 
734         case HCI_STATE_WORKING:
735             switch (power_mode){
736                 case HCI_POWER_ON:
737                     // do nothing
738                     break;
739                 case HCI_POWER_OFF:
740                     // see hci_run
741                     hci_stack.state = HCI_STATE_HALTING;
742                     break;
743                 case HCI_POWER_SLEEP:
744                     // see hci_run
745                     hci_stack.state = HCI_STATE_FALLING_ASLEEP;
746                     hci_stack.substate = 0;
747                     break;
748             }
749             break;
750 
751         case HCI_STATE_HALTING:
752             switch (power_mode){
753                 case HCI_POWER_ON:
754                     // set up state machine
755                     hci_stack.state = HCI_STATE_INITIALIZING;
756                     hci_stack.substate = 0;
757                     break;
758                 case HCI_POWER_OFF:
759                     // do nothing
760                     break;
761                 case HCI_POWER_SLEEP:
762                     // see hci_run
763                     hci_stack.state = HCI_STATE_FALLING_ASLEEP;
764                     hci_stack.substate = 0;
765                     break;
766             }
767             break;
768 
769         case HCI_STATE_FALLING_ASLEEP:
770             switch (power_mode){
771                 case HCI_POWER_ON:
772                     // set up state machine
773                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
774                     hci_stack.state = HCI_STATE_INITIALIZING;
775                     hci_stack.substate = 0;
776                     break;
777                 case HCI_POWER_OFF:
778                     // see hci_run
779                     hci_stack.state = HCI_STATE_HALTING;
780                     break;
781                 case HCI_POWER_SLEEP:
782                     // do nothing
783                     break;
784             }
785             break;
786 
787         case HCI_STATE_SLEEPING:
788             switch (power_mode){
789                 case HCI_POWER_ON:
790                     err = hci_power_control_wake();
791                     if (err) return err;
792                     // set up state machine
793                     hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
794                     hci_stack.state = HCI_STATE_INITIALIZING;
795                     hci_stack.substate = 0;
796                     break;
797                 case HCI_POWER_OFF:
798                     hci_stack.state = HCI_STATE_HALTING;
799                     break;
800                 case HCI_POWER_SLEEP:
801                     // do nothing
802                     break;
803             }
804             break;
805     }
806 
807     // create internal event
808 	hci_emit_state();
809 
810 	// trigger next/first action
811 	hci_run();
812 
813     return 0;
814 }
815 
816 void hci_discoverable_control(uint8_t enable){
817     if (enable) enable = 1; // normalize argument
818 
819     if (hci_stack.discoverable == enable){
820         hci_emit_discoverable_enabled(hci_stack.discoverable);
821         return;
822     }
823 
824     hci_send_cmd(&hci_write_scan_enable, 2 | enable); // 1 = inq scan, 2 = page scan
825     hci_stack.discoverable = enable;
826 }
827 
828 void hci_run(){
829 
830     if (hci_stack.num_cmd_packets == 0) {
831         // cannot send command yet
832         return;
833     }
834 
835     hci_connection_t * connection;
836 
837     switch (hci_stack.state){
838         case HCI_STATE_INITIALIZING:
839             if (hci_stack.substate % 2) {
840                 // odd: waiting for command completion
841                 return;
842             }
843             switch (hci_stack.substate >> 1){
844                 case 0: // RESET
845                     hci_send_cmd(&hci_reset);
846                     if (hci_stack.config == 0 || ((hci_uart_config_t *)hci_stack.config)->baudrate_main == 0){
847                         // skip baud change
848                         hci_stack.substate = 4; // >> 1 = 2
849                     }
850                     break;
851                 case 1: // SEND BAUD CHANGE
852                     hci_stack.control->baudrate_cmd(hci_stack.config, ((hci_uart_config_t *)hci_stack.config)->baudrate_main, hci_stack.hci_cmd_buffer);
853                     hci_send_cmd_packet(hci_stack.hci_cmd_buffer, 3 + hci_stack.hci_cmd_buffer[2]);
854                     break;
855                 case 2: // LOCAL BAUD CHANGE
856                     hci_stack.hci_transport->set_baudrate(((hci_uart_config_t *)hci_stack.config)->baudrate_main);
857                     hci_stack.substate += 2;
858                     // break missing here for fall through
859 
860                 case 3:
861                     // custom initialization
862                     if (hci_stack.control && hci_stack.control->next_command){
863                         uint8_t * cmd = (*hci_stack.control->next_command)(hci_stack.config);
864                         if (cmd) {
865                             int size = 3 + cmd[2];
866                             hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, cmd, size);
867                             hci_stack.substate = 4; // more init commands
868                             break;
869                         }
870                         printf("hci_run: init script done\n\r");
871                     }
872                     // otherwise continue
873 					hci_send_cmd(&hci_read_bd_addr);
874 					break;
875 				case 4:
876 					hci_send_cmd(&hci_read_buffer_size);
877 					break;
878                 case 5:
879                     // ca. 15 sec
880                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
881                     break;
882 				case 6:
883 					hci_send_cmd(&hci_write_scan_enable, 2 | hci_stack.discoverable); // page scan
884 					break;
885                 case 7:
886 #ifndef EMBEDDED
887                 {
888                     char hostname[30];
889                     gethostname(hostname, 30);
890                     hostname[29] = '\0';
891                     hci_send_cmd(&hci_write_local_name, hostname);
892                     break;
893                 }
894                 case 8:
895 #ifdef USE_BLUETOOL
896                     hci_send_cmd(&hci_write_class_of_device, 0x007a020c); // Smartphone
897                     break;
898 
899                 case 9:
900 #endif
901 #endif
902                     // done.
903                     hci_stack.state = HCI_STATE_WORKING;
904                     hci_emit_state();
905                     break;
906                 default:
907                     break;
908             }
909             hci_stack.substate++;
910             break;
911 
912         case HCI_STATE_HALTING:
913 
914             log_dbg("HCI_STATE_HALTING\n");
915             // close all open connections
916             connection =  (hci_connection_t *) hci_stack.connections;
917             if (connection){
918                 log_dbg("HCI_STATE_HALTING, connection %lu, handle %u\n", (uintptr_t) connection, connection->con_handle);
919                 // send disconnect
920                 hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
921 
922                 // send disconnected event right away - causes higher layer connections to get closed, too.
923                 hci_shutdown_connection(connection);
924                 return;
925             }
926             log_dbg("HCI_STATE_HALTING, calling off\n");
927 
928             // switch mode
929             hci_power_control_off();
930 
931             log_dbg("HCI_STATE_HALTING, emitting state\n");
932             hci_emit_state();
933             log_dbg("HCI_STATE_HALTING, done\n");
934             break;
935 
936         case HCI_STATE_FALLING_ASLEEP:
937             switch(hci_stack.substate) {
938                 case 0:
939                     log_dbg("HCI_STATE_FALLING_ASLEEP\n");
940                     // close all open connections
941                     connection =  (hci_connection_t *) hci_stack.connections;
942                     if (connection){
943                         log_dbg("HCI_STATE_FALLING_ASLEEP, connection %lu, handle %u\n", (uintptr_t) connection, connection->con_handle);
944                         // send disconnect
945                         hci_send_cmd(&hci_disconnect, connection->con_handle, 0x13);  // remote closed connection
946 
947                         // send disconnected event right away - causes higher layer connections to get closed, too.
948                         hci_shutdown_connection(connection);
949                         return;
950                     }
951 
952                     log_dbg("HCI_STATE_HALTING, disabling inq & page scans\n");
953 
954                     // disable page and inquiry scan
955                     hci_send_cmd(&hci_write_scan_enable, 0); // none
956 
957                     // continue in next sub state
958                     hci_stack.substate++;
959                     break;
960                 case 1:
961                     // wait for command complete "hci_write_scan_enable" in event_handler();
962                     break;
963                 case 2:
964                     log_dbg("HCI_STATE_HALTING, calling sleep\n");
965                     // switch mode
966                     hci_power_control_sleep();  // changes hci_stack.state to SLEEP
967                     hci_emit_state();
968                 default:
969                     break;
970             }
971             break;
972 
973         default:
974             break;
975     }
976 }
977 
978 int hci_send_cmd_packet(uint8_t *packet, int size){
979     bd_addr_t addr;
980     hci_connection_t * conn;
981     // house-keeping
982 
983     // create_connection?
984     if (IS_COMMAND(packet, hci_create_connection)){
985         bt_flip_addr(addr, &packet[3]);
986         log_dbg("Create_connection to "); print_bd_addr(addr); log_dbg("\n");
987         conn = connection_for_address(addr);
988         if (conn) {
989             // if connection exists
990             if (conn->state == OPEN) {
991                 // if OPEN, emit connection complete command
992                 hci_emit_connection_complete(conn);
993             }
994             //    otherwise, just ignore
995             return 0; // don't sent packet to controller
996 
997         } else{
998             conn = create_connection_for_addr(addr);
999             if (conn){
1000                 //    create connection struct and register, state = SENT_CREATE_CONNECTION
1001                 conn->state = SENT_CREATE_CONNECTION;
1002             }
1003         }
1004     }
1005 
1006     if (IS_COMMAND(packet, hci_link_key_request_reply)){
1007         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
1008     }
1009     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
1010         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
1011     }
1012     if (IS_COMMAND(packet, hci_pin_code_request_reply)){
1013         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_REPLY);
1014     }
1015     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)){
1016         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_NEGATIVE_REPLY);
1017     }
1018 
1019     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
1020         if (hci_stack.remote_device_db){
1021             bt_flip_addr(addr, &packet[3]);
1022             hci_stack.remote_device_db->delete_link_key(&addr);
1023         }
1024     }
1025 
1026     hci_stack.num_cmd_packets--;
1027     return hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
1028 }
1029 
1030 /**
1031  * pre: numcmds >= 0 - it's allowed to send a command to the controller
1032  */
1033 int hci_send_cmd(const hci_cmd_t *cmd, ...){
1034     va_list argptr;
1035     va_start(argptr, cmd);
1036     uint8_t * hci_cmd_buffer = hci_stack.hci_cmd_buffer;
1037     uint16_t size = hci_create_cmd_internal(hci_stack.hci_cmd_buffer, cmd, argptr);
1038     va_end(argptr);
1039     return hci_send_cmd_packet(hci_cmd_buffer, size);
1040 }
1041 
1042 // Create various non-HCI events.
1043 // TODO: generalize, use table similar to hci_create_command
1044 
1045 void hci_emit_state(){
1046     uint8_t len = 3;
1047     uint8_t event[len];
1048     event[0] = BTSTACK_EVENT_STATE;
1049     event[1] = len - 3;
1050     event[2] = hci_stack.state;
1051     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1052     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1053 }
1054 
1055 void hci_emit_connection_complete(hci_connection_t *conn){
1056     uint8_t len = 13;
1057     uint8_t event[len];
1058     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
1059     event[1] = len - 3;
1060     event[2] = 0; // status = OK
1061     bt_store_16(event, 3, conn->con_handle);
1062     bt_flip_addr(&event[5], conn->address);
1063     event[11] = 1; // ACL connection
1064     event[12] = 0; // encryption disabled
1065     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1066     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1067 }
1068 
1069 void hci_emit_disconnection_complete(uint16_t handle, uint8_t reason){
1070     uint8_t len = 6;
1071     uint8_t event[len];
1072     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
1073     event[1] = len - 3;
1074     event[2] = 0; // status = OK
1075     bt_store_16(event, 3, handle);
1076     event[5] = reason;
1077     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1078     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1079 }
1080 
1081 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
1082     uint8_t len = 4;
1083     uint8_t event[len];
1084     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
1085     event[1] = len - 2;
1086     bt_store_16(event, 2, conn->con_handle);
1087     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1088     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1089 }
1090 
1091 void hci_emit_nr_connections_changed(){
1092     uint8_t len = 3;
1093     uint8_t event[len];
1094     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
1095     event[1] = len - 2;
1096     event[2] = nr_hci_connections();
1097     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1098     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1099 }
1100 
1101 void hci_emit_hci_open_failed(){
1102     uint8_t len = 2;
1103     uint8_t event[len];
1104     event[0] = BTSTACK_EVENT_POWERON_FAILED;
1105     event[1] = len - 2;
1106     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1107     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1108 }
1109 
1110 
1111 void hci_emit_btstack_version() {
1112     uint8_t len = 6;
1113     uint8_t event[len];
1114     event[0] = BTSTACK_EVENT_VERSION;
1115     event[1] = len - 2;
1116     event[len++] = BTSTACK_MAJOR;
1117     event[len++] = BTSTACK_MINOR;
1118     bt_store_16(event, len, BTSTACK_REVISION);
1119     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1120     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1121 }
1122 
1123 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
1124     uint8_t len = 3;
1125     uint8_t event[len];
1126     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
1127     event[1] = len - 2;
1128     event[2] = enabled;
1129     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1130     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1131 }
1132 
1133 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
1134     uint16_t len = 2+1+6+248;
1135     uint8_t event[len];
1136     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
1137     event[1] = len - 2;
1138     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
1139     bt_flip_addr(&event[3], *addr);
1140     memcpy(&event[9], name, 248);
1141     hci_dump_packet(HCI_EVENT_PACKET, 0, event, len);
1142     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1143 }
1144 
1145 void hci_emit_discoverable_enabled(uint8_t enabled){
1146     uint8_t len = 3;
1147     uint8_t event[len];
1148     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
1149     event[1] = len - 2;
1150     event[2] = enabled;
1151     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
1152     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
1153 }
1154