xref: /btstack/src/hci.c (revision 74ec757acc3e17bddba7406252194eba225bfd67)
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 <unistd.h>
42 #include <stdarg.h>
43 #include <string.h>
44 #include <stdio.h>
45 
46 #include "debug.h"
47 #include "hci_dump.h"
48 
49 #include "../include/btstack/hci_cmds.h"
50 #include "../include/btstack/version.h"
51 
52 // temp
53 #include "l2cap.h"
54 
55 #define HCI_CONNECTION_TIMEOUT_MS 10000
56 
57 // the STACK is here
58 static hci_stack_t       hci_stack;
59 
60 /**
61  * get connection for a given handle
62  *
63  * @return connection OR NULL, if not found
64  */
65 hci_connection_t * connection_for_handle(hci_con_handle_t con_handle){
66     linked_item_t *it;
67     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
68         if ( ((hci_connection_t *) it)->con_handle == con_handle){
69             return (hci_connection_t *) it;
70         }
71     }
72     return NULL;
73 }
74 
75 static void hci_connection_timeout_handler(timer_source_t *timer){
76     hci_connection_t * connection = linked_item_get_user(&timer->item);
77     struct timeval tv;
78     gettimeofday(&tv, NULL);
79     if (tv.tv_sec >= connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000) {
80         // connections might be timed out
81         hci_emit_l2cap_check_timeout(connection);
82         run_loop_set_timer(timer, HCI_CONNECTION_TIMEOUT_MS);
83     } else {
84         // next timeout check at
85         timer->timeout.tv_sec = connection->timestamp.tv_sec + HCI_CONNECTION_TIMEOUT_MS/1000;
86     }
87     run_loop_add_timer(timer);
88 }
89 
90 static void hci_connection_timestamp(hci_connection_t *connection){
91     gettimeofday(&connection->timestamp, NULL);
92 }
93 
94 /**
95  * create connection for given address
96  *
97  * @return connection OR NULL, if not found
98  */
99 static hci_connection_t * create_connection_for_addr(bd_addr_t addr){
100     hci_connection_t * conn = malloc( sizeof(hci_connection_t) );
101     if (!conn) return NULL;
102     BD_ADDR_COPY(conn->address, addr);
103     conn->con_handle = 0xffff;
104     conn->authentication_flags = 0;
105     linked_item_set_user(&conn->timeout.item, conn);
106     conn->timeout.process = hci_connection_timeout_handler;
107     hci_connection_timestamp(conn);
108     conn->acl_recombination_length = 0;
109     conn->acl_recombination_pos = 0;
110     conn->num_acl_packets_sent = 0;
111     linked_list_add(&hci_stack.connections, (linked_item_t *) conn);
112     return conn;
113 }
114 
115 /**
116  * get connection for given address
117  *
118  * @return connection OR NULL, if not found
119  */
120 static hci_connection_t * connection_for_address(bd_addr_t address){
121     linked_item_t *it;
122     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
123         if ( ! BD_ADDR_CMP( ((hci_connection_t *) it)->address, address) ){
124             return (hci_connection_t *) it;
125         }
126     }
127     return NULL;
128 }
129 
130 /**
131  * add authentication flags and reset timer
132  */
133 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
134     bd_addr_t addr;
135     bt_flip_addr(addr, *(bd_addr_t *) bd_addr);
136     hci_connection_t * conn = connection_for_address(addr);
137     if (conn) {
138         conn->authentication_flags |= flags;
139         hci_connection_timestamp(conn);
140     }
141 }
142 
143 int  hci_authentication_active_for_handle(hci_con_handle_t handle){
144     hci_connection_t * conn = connection_for_handle(handle);
145     if (!conn) return 0;
146     if (!conn->authentication_flags) return 0;
147     if (conn->authentication_flags & SENT_LINK_KEY_REPLY) return 0;
148     if (conn->authentication_flags & RECV_LINK_KEY_NOTIFICATION) return 0;
149     return 1;
150 }
151 
152 void hci_drop_link_key_for_bd_addr(bd_addr_t *addr){
153     if (hci_stack.remote_device_db) {
154         hci_stack.remote_device_db->delete_link_key(addr);
155     }
156 }
157 
158 
159 /**
160  * count connections
161  */
162 static int nr_hci_connections(){
163     int count = 0;
164     linked_item_t *it;
165     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next, count++);
166     return count;
167 }
168 
169 /**
170  * Dummy handler called by HCI
171  */
172 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
173 }
174 
175 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
176     hci_connection_t * connection = connection_for_handle(handle);
177     if (!connection) {
178         log_err("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
179         return 0;
180     }
181     return connection->num_acl_packets_sent;
182 }
183 
184 uint8_t hci_number_free_acl_slots(){
185     uint8_t free_slots = hci_stack.total_num_acl_packets;
186     linked_item_t *it;
187     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
188         hci_connection_t * connection = (hci_connection_t *) it;
189         if (free_slots < connection->num_acl_packets_sent) {
190             log_err("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
191             return 0;
192         }
193         free_slots -= connection->num_acl_packets_sent;
194     }
195     return free_slots;
196 }
197 
198 int hci_ready_to_send(hci_con_handle_t handle){
199     return hci_number_free_acl_slots() && hci_number_outgoing_packets(handle) < 2;
200 }
201 
202 int hci_send_acl_packet(uint8_t *packet, int size){
203 
204     // check for free places on BT module
205     if (!hci_number_free_acl_slots()) return -1;
206 
207     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
208     hci_connection_t *connection = connection_for_handle( con_handle);
209     if (!connection) return 0;
210     hci_connection_timestamp(connection);
211 
212     // count packet
213     connection->num_acl_packets_sent++;
214     // log_dbg("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
215 
216     // send packet - ignore errors
217     hci_stack.hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
218 
219     return 0;
220 }
221 
222 static void acl_handler(uint8_t *packet, int size){
223 
224     // get info
225     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
226     hci_connection_t *conn      = connection_for_handle(con_handle);
227     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
228     uint16_t acl_length         = READ_ACL_LENGTH(packet);
229 
230     // ignore non-registered handle
231     if (!conn){
232         log_err( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
233         return;
234     }
235 
236     // update idle timestamp
237     hci_connection_timestamp(conn);
238 
239     // handle different packet types
240     switch (acl_flags & 0x03) {
241 
242         case 0x01: // continuation fragment
243 
244             // sanity check
245             if (conn->acl_recombination_pos == 0) {
246                 log_err( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
247                 return;
248             }
249 
250             // append fragment payload (header already stored)
251             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
252             conn->acl_recombination_pos += acl_length;
253 
254             // log_err( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n",
255             //        acl_length, connection->acl_recombination_pos, connection->acl_recombination_length);
256 
257             // forward complete L2CAP packet if complete.
258             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
259 
260                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
261                 // reset recombination buffer
262                 conn->acl_recombination_length = 0;
263                 conn->acl_recombination_pos = 0;
264             }
265             break;
266 
267         case 0x02: { // first fragment
268 
269             // sanity check
270             if (conn->acl_recombination_pos) {
271                 log_err( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
272                 return;
273             }
274 
275             // peek into L2CAP packet!
276             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
277 
278             // compare fragment size to L2CAP packet size
279             if (acl_length >= l2cap_length + 4){
280 
281                 // forward fragment as L2CAP packet
282                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
283 
284             } else {
285                 // store first fragment and tweak acl length for complete package
286                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
287                 conn->acl_recombination_pos    = acl_length + 4;
288                 conn->acl_recombination_length = l2cap_length;
289                 bt_store_16(conn->acl_recombination_buffer, 2, acl_length +4);
290                 // log_err( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
291             }
292             break;
293 
294         }
295         default:
296             log_err( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
297             return;
298     }
299 
300     // execute main loop
301     hci_run();
302 }
303 
304 // avoid huge local variables
305 static device_name_t device_name;
306 static void event_handler(uint8_t *packet, int size){
307     bd_addr_t addr;
308     hci_con_handle_t handle;
309     hci_connection_t * conn;
310     int i;
311     link_key_t link_key;
312 
313     // get num_cmd_packets
314     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
315         // Get Num_HCI_Command_Packets
316         hci_stack.num_cmd_packets = packet[2];
317     }
318 
319     switch (packet[0]) {
320 
321         case HCI_EVENT_COMMAND_COMPLETE:
322             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
323                 // from offset 5
324                 // status
325                 hci_stack.acl_data_packet_length = READ_BT_16(packet, 6);
326                 // ignore: SCO data packet len (8)
327                 hci_stack.total_num_acl_packets  = packet[9];
328                 // ignore: total num SCO packets
329                 if (hci_stack.state == HCI_STATE_INITIALIZING){
330                     log_dbg("hci_read_buffer_size: size %u, count %u\n", hci_stack.acl_data_packet_length, hci_stack.total_num_acl_packets);
331                 }
332             }
333             break;
334 
335         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
336             for (i=0; i<packet[2];i++){
337                 handle = READ_BT_16(packet, 3 + 2*i);
338                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
339                 conn = connection_for_handle(handle);
340                 if (!conn){
341                     log_err("hci_number_completed_packet lists unused con handle %u\n", handle);
342                     continue;
343                 }
344                 conn->num_acl_packets_sent -= num_packets;
345                 // log_dbg("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
346             }
347             break;
348 
349         case HCI_EVENT_CONNECTION_REQUEST:
350             bt_flip_addr(addr, &packet[2]);
351             // TODO: eval COD 8-10
352             uint8_t link_type = packet[11];
353             log_dbg("Connection_incoming: "); print_bd_addr(addr); log_dbg(", type %u\n", link_type);
354             if (link_type == 1) { // ACL
355                 conn = connection_for_address(addr);
356                 if (!conn) {
357                     conn = create_connection_for_addr(addr);
358                 }
359                 // TODO: check for malloc failure
360                 conn->state = ACCEPTED_CONNECTION_REQUEST;
361                 hci_send_cmd(&hci_accept_connection_request, addr, 1);
362             } else {
363                 // TODO: decline request
364             }
365             break;
366 
367         case HCI_EVENT_CONNECTION_COMPLETE:
368             // Connection management
369             bt_flip_addr(addr, &packet[5]);
370             log_dbg("Connection_complete (status=%u)", packet[2]); print_bd_addr(addr); log_dbg("\n");
371             conn = connection_for_address(addr);
372             if (conn) {
373                 if (!packet[2]){
374                     conn->state = OPEN;
375                     conn->con_handle = READ_BT_16(packet, 3);
376 
377                     gettimeofday(&conn->timestamp, NULL);
378                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
379                     run_loop_add_timer(&conn->timeout);
380 
381                     log_dbg("New connection: handle %u, ", conn->con_handle);
382                     print_bd_addr( conn->address );
383                     log_dbg("\n");
384 
385                     hci_emit_nr_connections_changed();
386                 } else {
387                     // connection failed, remove entry
388                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
389                     free( conn );
390 
391                     // if authentication error, also delete link key
392                     if (packet[2] == 0x05) {
393                         hci_drop_link_key_for_bd_addr(&addr);
394                     }
395                 }
396             }
397             break;
398 
399         case HCI_EVENT_LINK_KEY_REQUEST:
400             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
401             if (!hci_stack.remote_device_db) break;
402             bt_flip_addr(addr, &packet[2]);
403             if ( hci_stack.remote_device_db->get_link_key( &addr, &link_key)){
404                 hci_send_cmd(&hci_link_key_request_reply, &addr, &link_key);
405             } else {
406                 hci_send_cmd(&hci_link_key_request_negative_reply, &addr);
407             }
408             // request already answered
409             return;
410 
411         case HCI_EVENT_LINK_KEY_NOTIFICATION:
412             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_NOTIFICATION);
413             if (!hci_stack.remote_device_db) break;
414             bt_flip_addr(addr, &packet[2]);
415             hci_stack.remote_device_db->put_link_key(&addr, &link_key);
416             // still forward event to allow dismiss of pairing dialog
417             break;
418 
419         case HCI_EVENT_PIN_CODE_REQUEST:
420             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_PIN_CODE_REQUEST);
421             break;
422 
423         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
424             if (!hci_stack.remote_device_db) break;
425             if (packet[2]) break; // status not ok
426             bt_flip_addr(addr, &packet[3]);
427             bzero(&device_name, sizeof(device_name_t));
428             strncpy((char*) device_name, (char*) &packet[9], 248);
429             hci_stack.remote_device_db->put_name(&addr, &device_name);
430             break;
431 
432         case HCI_EVENT_INQUIRY_RESULT:
433         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
434             if (!hci_stack.remote_device_db) break;
435             // first send inq result packet
436             hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
437             // then send cached remote names
438             for (i=0; i<packet[2];i++){
439                 bt_flip_addr(addr, &packet[3+i*6]);
440                 if (hci_stack.remote_device_db->get_name(&addr, &device_name)){
441                     hci_emit_remote_name_cached(&addr, &device_name);
442                 }
443             }
444             return;
445 
446         case HCI_EVENT_DISCONNECTION_COMPLETE:
447             if (!packet[2]){
448                 handle = READ_BT_16(packet, 3);
449                 hci_connection_t * conn = connection_for_handle(handle);
450                 if (conn) {
451                     log_dbg("Connection closed: handle %u, ", conn->con_handle);
452                     print_bd_addr( conn->address );
453                     log_dbg("\n");
454                     run_loop_remove_timer(&conn->timeout);
455                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
456                     free( conn );
457                     hci_emit_nr_connections_changed();
458                 }
459             }
460             break;
461 
462         default:
463             break;
464     }
465 
466     // handle BT initialization
467     if (hci_stack.state == HCI_STATE_INITIALIZING){
468         // handle H4 synchronization loss on restart
469         // if (hci_stack.substate == 1 && packet[0] == HCI_EVENT_HARDWARE_ERROR){
470         //    hci_stack.substate = 0;
471         // }
472         // handle normal init sequence
473         if (hci_stack.substate % 2){
474             // odd: waiting for event
475             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
476                 hci_stack.substate++;
477             }
478         }
479     }
480 
481     hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
482 
483 	// execute main loop
484 	hci_run();
485 }
486 
487 void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
488     switch (packet_type) {
489         case HCI_EVENT_PACKET:
490             event_handler(packet, size);
491             break;
492         case HCI_ACL_DATA_PACKET:
493             acl_handler(packet, size);
494             break;
495         default:
496             break;
497     }
498 }
499 
500 /** Register HCI packet handlers */
501 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
502     hci_stack.packet_handler = handler;
503 }
504 
505 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t * remote_device_db){
506 
507     // reference to use transport layer implementation
508     hci_stack.hci_transport = transport;
509 
510     // references to used control implementation
511     hci_stack.control = control;
512 
513     // reference to used config
514     hci_stack.config = config;
515 
516     // no connections yet
517     hci_stack.connections = NULL;
518 
519     // empty cmd buffer
520     hci_stack.hci_cmd_buffer = malloc(3+255);
521 
522     // higher level handler
523     hci_stack.packet_handler = dummy_handler;
524 
525     // store and open remote device db
526     hci_stack.remote_device_db = remote_device_db;
527     if (hci_stack.remote_device_db) {
528         hci_stack.remote_device_db->open();
529     }
530 
531     // register packet handlers with transport
532     transport->register_packet_handler(&packet_handler);
533 }
534 
535 void hci_close(){
536     // close remote device db
537     if (hci_stack.remote_device_db) {
538         hci_stack.remote_device_db->close();
539     }
540 }
541 
542 int hci_power_control(HCI_POWER_MODE power_mode){
543     if (power_mode == HCI_POWER_ON && hci_stack.state == HCI_STATE_OFF) {
544 
545         // power on
546         int err = 0;
547         if (hci_stack.control && hci_stack.control->on){
548             err = (*hci_stack.control->on)(hci_stack.config);
549         }
550         if (err){
551             log_err( "POWER_ON failed\n");
552             hci_emit_hci_open_failed();
553             return err;
554         }
555 
556         // open low-level device
557         err = hci_stack.hci_transport->open(hci_stack.config);
558         if (err){
559             log_err( "HCI_INIT failed, turning Bluetooth off again\n");
560             if (hci_stack.control && hci_stack.control->off){
561                 (*hci_stack.control->off)(hci_stack.config);
562             }
563             hci_emit_hci_open_failed();
564             return err;
565         }
566 
567         // set up state machine
568         hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
569         hci_stack.state = HCI_STATE_INITIALIZING;
570         hci_stack.substate = 0;
571 
572     } else if (power_mode == HCI_POWER_OFF && hci_stack.state == HCI_STATE_WORKING){
573 
574         // close low-level device
575         hci_stack.hci_transport->close(hci_stack.config);
576 
577         // power off
578         if (hci_stack.control && hci_stack.control->off){
579             (*hci_stack.control->off)(hci_stack.config);
580         }
581 
582         // we're off now
583         hci_stack.state = HCI_STATE_OFF;
584     }
585 
586     // create internal event
587 	hci_emit_state();
588 
589 	// trigger next/first action
590 	hci_run();
591 
592     return 0;
593 }
594 
595 void hci_run(){
596 
597     switch (hci_stack.state){
598         case HCI_STATE_INITIALIZING:
599             if (hci_stack.substate % 2) {
600                 // odd: waiting for command completion
601                 return;
602             }
603             if (hci_stack.num_cmd_packets == 0) {
604                 // cannot send command yet
605                 return;
606             }
607             switch (hci_stack.substate >> 1){
608                 case 0:
609                     hci_send_cmd(&hci_reset);
610                     break;
611                 case 1:
612                     // custom initialization
613                     if (hci_stack.control && hci_stack.control->next_command){
614                         uint8_t * cmd = (*hci_stack.control->next_command)(hci_stack.config);
615                         if (cmd) {
616                             int size = 3 + cmd[2];
617                             hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, cmd, size);
618                             hci_stack.substate = 0; // more init commands
619                             break;
620                         }
621                     }
622                     // otherwise continue
623 					hci_send_cmd(&hci_read_bd_addr);
624 					break;
625 				case 2:
626 					hci_send_cmd(&hci_read_buffer_size);
627 					break;
628                 case 3:
629                     // ca. 15 sec
630                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
631                     break;
632 				case 4:
633 					hci_send_cmd(&hci_write_scan_enable, 3); // 3 inq scan + page scan
634 					break;
635                 case 5:
636 #ifndef EMBEDDED
637                 {
638                     char hostname[30];
639                     gethostname(hostname, 30);
640                     hostname[29] = '\0';
641                     hci_send_cmd(&hci_write_local_name, hostname);
642                     break;
643                 }
644                 case 6:
645 #endif
646                     // done.
647                     hci_stack.state = HCI_STATE_WORKING;
648                     hci_emit_state();
649                     break;
650                 default:
651                     break;
652             }
653             hci_stack.substate++;
654             break;
655         default:
656             break;
657     }
658 }
659 
660 int hci_send_cmd_packet(uint8_t *packet, int size){
661     bd_addr_t addr;
662     hci_connection_t * conn;
663     // house-keeping
664 
665     // create_connection?
666     if (IS_COMMAND(packet, hci_create_connection)){
667         bt_flip_addr(addr, &packet[3]);
668         log_dbg("Create_connection to "); print_bd_addr(addr); log_dbg("\n");
669         conn = connection_for_address(addr);
670         if (conn) {
671             // if connection exists
672             if (conn->state == OPEN) {
673                 // if OPEN, emit connection complete command
674                 hci_emit_connection_complete(conn);
675             }
676             //    otherwise, just ignore
677             return 0; // don't sent packet to controller
678 
679         } else{
680             conn = create_connection_for_addr(addr);
681             if (conn){
682                 //    create connection struct and register, state = SENT_CREATE_CONNECTION
683                 conn->state = SENT_CREATE_CONNECTION;
684             }
685         }
686     }
687 
688     if (IS_COMMAND(packet, hci_link_key_request_reply)){
689         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
690     }
691     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
692         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
693     }
694     if (IS_COMMAND(packet, hci_pin_code_request_reply)){
695         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_REPLY);
696     }
697     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)){
698         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_NEGATIVE_REPLY);
699     }
700 
701     // accept connection
702 
703     // reject connection
704 
705     // close_connection?
706       // set state = SENT_DISCONNECT
707 
708     hci_stack.num_cmd_packets--;
709     return hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
710 }
711 
712 /**
713  * pre: numcmds >= 0 - it's allowed to send a command to the controller
714  */
715 int hci_send_cmd(const hci_cmd_t *cmd, ...){
716     va_list argptr;
717     va_start(argptr, cmd);
718     uint8_t * hci_cmd_buffer = hci_stack.hci_cmd_buffer;
719     uint16_t size = hci_create_cmd_internal(hci_stack.hci_cmd_buffer, cmd, argptr);
720     va_end(argptr);
721     return hci_send_cmd_packet(hci_cmd_buffer, size);
722 }
723 
724 // Create various non-HCI events.
725 // TODO: generalize, use table similar to hci_create_command
726 
727 void hci_emit_state(){
728     uint8_t len = 3;
729     uint8_t event[len];
730     event[0] = BTSTACK_EVENT_STATE;
731     event[1] = len - 3;
732     event[2] = hci_stack.state;
733     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
734     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
735 }
736 
737 void hci_emit_connection_complete(hci_connection_t *conn){
738     uint8_t len = 13;
739     uint8_t event[len];
740     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
741     event[1] = len - 3;
742     event[2] = 0; // status = OK
743     bt_store_16(event, 3, conn->con_handle);
744     bt_flip_addr(&event[5], conn->address);
745     event[11] = 1; // ACL connection
746     event[12] = 0; // encryption disabled
747     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
748     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
749 }
750 
751 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
752     uint8_t len = 4;
753     uint8_t event[len];
754     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
755     event[1] = len - 2;
756     bt_store_16(event, 2, conn->con_handle);
757     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
758     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
759 }
760 
761 void hci_emit_nr_connections_changed(){
762     uint8_t len = 3;
763     uint8_t event[len];
764     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
765     event[1] = len - 2;
766     event[2] = nr_hci_connections();
767     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
768     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
769 }
770 
771 void hci_emit_hci_open_failed(){
772     uint8_t len = 2;
773     uint8_t event[len];
774     event[0] = BTSTACK_EVENT_POWERON_FAILED;
775     event[1] = len - 2;
776     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
777     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
778 }
779 
780 
781 void hci_emit_btstack_version() {
782     uint8_t len = 6;
783     uint8_t event[len];
784     event[0] = BTSTACK_EVENT_VERSION;
785     event[1] = len - 2;
786     event[len++] = BTSTACK_MAJOR;
787     event[len++] = BTSTACK_MINOR;
788     bt_store_16(event, len, BTSTACK_REVISION);
789     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
790     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
791 }
792 
793 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
794     uint8_t len = 3;
795     uint8_t event[len];
796     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
797     event[1] = len - 2;
798     event[2] = enabled;
799     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
800     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
801 }
802 
803 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
804     uint16_t len = 2+6+248;
805     uint8_t event[len];
806     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
807     event[1] = len - 2;
808     BD_ADDR_COPY(&event[2], addr);
809     memcpy(&event[8], name, 248);
810     hci_dump_packet(HCI_EVENT_PACKET, 0, event, len);
811     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
812 }
813