xref: /btstack/src/hci.c (revision 80ca58a00d3e7bba582028bd39a536fdffcf5da3)
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 
153 /**
154  * count connections
155  */
156 static int nr_hci_connections(){
157     int count = 0;
158     linked_item_t *it;
159     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next, count++);
160     return count;
161 }
162 
163 /**
164  * Dummy handler called by HCI
165  */
166 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
167 }
168 
169 uint8_t hci_number_outgoing_packets(hci_con_handle_t handle){
170     hci_connection_t * connection = connection_for_handle(handle);
171     if (!connection) {
172         log_err("hci_number_outgoing_packets connectino for handle %u does not exist!\n", handle);
173         return 0;
174     }
175     return connection->num_acl_packets_sent;
176 }
177 
178 uint8_t hci_number_free_acl_slots(){
179     uint8_t free_slots = hci_stack.total_num_acl_packets;
180     linked_item_t *it;
181     for (it = (linked_item_t *) hci_stack.connections; it ; it = it->next){
182         hci_connection_t * connection = (hci_connection_t *) it;
183         if (free_slots < connection->num_acl_packets_sent) {
184             log_err("hci_number_free_acl_slots: sum of outgoing packets > total acl packets!\n");
185             return 0;
186         }
187         free_slots -= connection->num_acl_packets_sent;
188     }
189     return free_slots;
190 }
191 
192 int hci_ready_to_send(hci_con_handle_t handle){
193     return hci_number_free_acl_slots() && hci_number_outgoing_packets(handle) < 2;
194 }
195 
196 int hci_send_acl_packet(uint8_t *packet, int size){
197 
198     // check for free places on BT module
199     if (!hci_number_free_acl_slots()) return -1;
200 
201     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
202     hci_connection_t *connection = connection_for_handle( con_handle);
203     if (!connection) return 0;
204     hci_connection_timestamp(connection);
205 
206     // count packet
207     connection->num_acl_packets_sent++;
208     // log_dbg("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
209 
210     // send packet - ignore errors
211     hci_stack.hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
212 
213     return 0;
214 }
215 
216 static void acl_handler(uint8_t *packet, int size){
217 
218     // get info
219     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
220     hci_connection_t *conn      = connection_for_handle(con_handle);
221     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
222     uint16_t acl_length         = READ_ACL_LENGTH(packet);
223 
224     // ignore non-registered handle
225     if (!conn){
226         log_err( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
227         return;
228     }
229 
230     // update idle timestamp
231     hci_connection_timestamp(conn);
232 
233     // handle different packet types
234     switch (acl_flags & 0x03) {
235 
236         case 0x01: // continuation fragment
237 
238             // sanity check
239             if (conn->acl_recombination_pos == 0) {
240                 log_err( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
241                 return;
242             }
243 
244             // append fragment payload (header already stored)
245             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
246             conn->acl_recombination_pos += acl_length;
247 
248             // log_err( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n",
249             //        acl_length, connection->acl_recombination_pos, connection->acl_recombination_length);
250 
251             // forward complete L2CAP packet if complete.
252             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
253 
254                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
255                 // reset recombination buffer
256                 conn->acl_recombination_length = 0;
257                 conn->acl_recombination_pos = 0;
258             }
259             break;
260 
261         case 0x02: { // first fragment
262 
263             // sanity check
264             if (conn->acl_recombination_pos) {
265                 log_err( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
266                 return;
267             }
268 
269             // peek into L2CAP packet!
270             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
271 
272             // compare fragment size to L2CAP packet size
273             if (acl_length >= l2cap_length + 4){
274 
275                 // forward fragment as L2CAP packet
276                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
277 
278             } else {
279                 // store first fragment and tweak acl length for complete package
280                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
281                 conn->acl_recombination_pos    = acl_length + 4;
282                 conn->acl_recombination_length = l2cap_length;
283                 bt_store_16(conn->acl_recombination_buffer, 2, acl_length +4);
284                 // log_err( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
285             }
286             break;
287 
288         }
289         default:
290             log_err( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
291             return;
292     }
293 
294     // execute main loop
295     hci_run();
296 }
297 
298 static void event_handler(uint8_t *packet, int size){
299     bd_addr_t addr;
300     hci_con_handle_t handle;
301     hci_connection_t * conn;
302     int i;
303 
304     // get num_cmd_packets
305     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
306         // Get Num_HCI_Command_Packets
307         hci_stack.num_cmd_packets = packet[2];
308     }
309 
310     switch (packet[0]) {
311 
312         case HCI_EVENT_COMMAND_COMPLETE:
313             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
314                 // from offset 5
315                 // status
316                 hci_stack.acl_data_packet_length = READ_BT_16(packet, 6);
317                 // ignore: SCO data packet len (8)
318                 hci_stack.total_num_acl_packets  = packet[9];
319                 // ignore: total num SCO packets
320                 if (hci_stack.state == HCI_STATE_INITIALIZING){
321                     log_dbg("hci_read_buffer_size: size %u, count %u\n", hci_stack.acl_data_packet_length, hci_stack.total_num_acl_packets);
322                 }
323             }
324             break;
325 
326         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
327             for (i=0; i<packet[2];i++){
328                 handle = READ_BT_16(packet, 3 + 2*i);
329                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
330                 conn = connection_for_handle(handle);
331                 if (!conn){
332                     log_err("hci_number_completed_packet lists unused con handle %u\n", handle);
333                     continue;
334                 }
335                 conn->num_acl_packets_sent -= num_packets;
336                 // log_dbg("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
337             }
338             break;
339 
340         case HCI_EVENT_CONNECTION_REQUEST:
341             bt_flip_addr(addr, &packet[2]);
342             // TODO: eval COD 8-10
343             uint8_t link_type = packet[11];
344             log_dbg("Connection_incoming: "); print_bd_addr(addr); log_dbg(", type %u\n", link_type);
345             if (link_type == 1) { // ACL
346                 conn = connection_for_address(addr);
347                 if (!conn) {
348                     conn = create_connection_for_addr(addr);
349                 }
350                 // TODO: check for malloc failure
351                 conn->state = ACCEPTED_CONNECTION_REQUEST;
352                 hci_send_cmd(&hci_accept_connection_request, addr, 1);
353             } else {
354                 // TODO: decline request
355             }
356             break;
357 
358         case HCI_EVENT_CONNECTION_COMPLETE:
359             // Connection management
360             bt_flip_addr(addr, &packet[5]);
361             log_dbg("Connection_complete (status=%u)", packet[2]); print_bd_addr(addr); log_dbg("\n");
362             conn = connection_for_address(addr);
363             if (conn) {
364                 if (!packet[2]){
365                     conn->state = OPEN;
366                     conn->con_handle = READ_BT_16(packet, 3);
367 
368                     gettimeofday(&conn->timestamp, NULL);
369                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
370                     run_loop_add_timer(&conn->timeout);
371 
372                     log_dbg("New connection: handle %u, ", conn->con_handle);
373                     print_bd_addr( conn->address );
374                     log_dbg("\n");
375 
376                     hci_emit_nr_connections_changed();
377                 } else {
378                     // connection failed, remove entry
379                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
380                     free( conn );
381                 }
382             }
383             break;
384 
385         case HCI_EVENT_LINK_KEY_REQUEST:
386             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
387             break;
388 
389         case HCI_EVENT_LINK_KEY_NOTIFICATION:
390             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_NOTIFICATION);
391             break;
392 
393         case HCI_EVENT_PIN_CODE_REQUEST:
394             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_PIN_CODE_REQUEST);
395             break;
396 
397         case HCI_EVENT_DISCONNECTION_COMPLETE:
398             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
399             if (!packet[2]){
400                 handle = READ_BT_16(packet, 3);
401                 hci_connection_t * conn = connection_for_handle(handle);
402                 if (conn) {
403                     log_dbg("Connection closed: handle %u, ", conn->con_handle);
404                     print_bd_addr( conn->address );
405                     log_dbg("\n");
406                     run_loop_remove_timer(&conn->timeout);
407                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
408                     free( conn );
409                     hci_emit_nr_connections_changed();
410                 }
411             }
412             break;
413 
414         default:
415             break;
416     }
417 
418     // handle BT initialization
419     if (hci_stack.state == HCI_STATE_INITIALIZING){
420         // handle H4 synchronization loss on restart
421         // if (hci_stack.substate == 1 && packet[0] == HCI_EVENT_HARDWARE_ERROR){
422         //    hci_stack.substate = 0;
423         // }
424         // handle normal init sequence
425         if (hci_stack.substate % 2){
426             // odd: waiting for event
427             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
428                 hci_stack.substate++;
429             }
430         }
431     }
432 
433     hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
434 
435 	// execute main loop
436 	hci_run();
437 }
438 
439 void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
440     switch (packet_type) {
441         case HCI_EVENT_PACKET:
442             event_handler(packet, size);
443             break;
444         case HCI_ACL_DATA_PACKET:
445             acl_handler(packet, size);
446             break;
447         default:
448             break;
449     }
450 }
451 
452 /** Register HCI packet handlers */
453 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
454     hci_stack.packet_handler = handler;
455 }
456 
457 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control){
458 
459     // reference to use transport layer implementation
460     hci_stack.hci_transport = transport;
461 
462     // references to used control implementation
463     hci_stack.control = control;
464 
465     // reference to used config
466     hci_stack.config = config;
467 
468     // no connections yet
469     hci_stack.connections = NULL;
470 
471     // empty cmd buffer
472     hci_stack.hci_cmd_buffer = malloc(3+255);
473 
474     // higher level handler
475     hci_stack.packet_handler = dummy_handler;
476 
477     // register packet handlers with transport
478     transport->register_packet_handler(&packet_handler);
479 }
480 
481 int hci_power_control(HCI_POWER_MODE power_mode){
482     if (power_mode == HCI_POWER_ON && hci_stack.state == HCI_STATE_OFF) {
483 
484         // power on
485         int err = 0;
486         if (hci_stack.control && hci_stack.control->on){
487             err = (*hci_stack.control->on)(hci_stack.config);
488         }
489         if (err){
490             log_err( "POWER_ON failed\n");
491             hci_emit_hci_open_failed();
492             return err;
493         }
494 
495         // open low-level device
496         err = hci_stack.hci_transport->open(hci_stack.config);
497         if (err){
498             log_err( "HCI_INIT failed, turning Bluetooth off again\n");
499             if (hci_stack.control && hci_stack.control->off){
500                 (*hci_stack.control->off)(hci_stack.config);
501             }
502             hci_emit_hci_open_failed();
503             return err;
504         }
505 
506         // set up state machine
507         hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
508         hci_stack.state = HCI_STATE_INITIALIZING;
509         hci_stack.substate = 0;
510 
511     } else if (power_mode == HCI_POWER_OFF && hci_stack.state == HCI_STATE_WORKING){
512 
513         // close low-level device
514         hci_stack.hci_transport->close(hci_stack.config);
515 
516         // power off
517         if (hci_stack.control && hci_stack.control->off){
518             (*hci_stack.control->off)(hci_stack.config);
519         }
520 
521         // we're off now
522         hci_stack.state = HCI_STATE_OFF;
523     }
524 
525     // create internal event
526 	hci_emit_state();
527 
528 	// trigger next/first action
529 	hci_run();
530 
531     return 0;
532 }
533 
534 void hci_run(){
535 
536     switch (hci_stack.state){
537         case HCI_STATE_INITIALIZING:
538             if (hci_stack.substate % 2) {
539                 // odd: waiting for command completion
540                 return;
541             }
542             if (hci_stack.num_cmd_packets == 0) {
543                 // cannot send command yet
544                 return;
545             }
546             switch (hci_stack.substate >> 1){
547                 case 0:
548                     hci_send_cmd(&hci_reset);
549                     break;
550                 case 1:
551                     // custom initialization
552                     if (hci_stack.control && hci_stack.control->next_command){
553                         uint8_t * cmd = (*hci_stack.control->next_command)(hci_stack.config);
554                         if (cmd) {
555                             int size = 3 + cmd[2];
556                             hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, cmd, size);
557                             hci_stack.substate = 0; // more init commands
558                             break;
559                         }
560                     }
561                     // otherwise continue
562 					hci_send_cmd(&hci_read_bd_addr);
563 					break;
564 				case 2:
565 					hci_send_cmd(&hci_read_buffer_size);
566 					break;
567                 case 3:
568                     // ca. 15 sec
569                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
570                     break;
571 				case 4:
572 					hci_send_cmd(&hci_write_scan_enable, 3); // 3 inq scan + page scan
573 					break;
574                 case 5:
575 #ifndef EMBEDDED
576                 {
577                     char hostname[30];
578                     gethostname(hostname, 30);
579                     hostname[29] = '\0';
580                     hci_send_cmd(&hci_write_local_name, hostname);
581                     break;
582                 }
583                 case 6:
584 #endif
585                     // done.
586                     hci_stack.state = HCI_STATE_WORKING;
587                     hci_emit_state();
588                     break;
589                 default:
590                     break;
591             }
592             hci_stack.substate++;
593             break;
594         default:
595             break;
596     }
597 }
598 
599 int hci_send_cmd_packet(uint8_t *packet, int size){
600     bd_addr_t addr;
601     hci_connection_t * conn;
602     // house-keeping
603 
604     // create_connection?
605     if (IS_COMMAND(packet, hci_create_connection)){
606         bt_flip_addr(addr, &packet[3]);
607         log_dbg("Create_connection to "); print_bd_addr(addr); log_dbg("\n");
608         conn = connection_for_address(addr);
609         if (conn) {
610             // if connection exists
611             if (conn->state == OPEN) {
612                 // if OPEN, emit connection complete command
613                 hci_emit_connection_complete(conn);
614             }
615             //    otherwise, just ignore
616             return 0; // don't sent packet to controller
617 
618         } else{
619             conn = create_connection_for_addr(addr);
620             if (conn){
621                 //    create connection struct and register, state = SENT_CREATE_CONNECTION
622                 conn->state = SENT_CREATE_CONNECTION;
623             }
624         }
625     }
626 
627     if (IS_COMMAND(packet, hci_link_key_request_reply)){
628         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
629     }
630     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
631         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
632     }
633     if (IS_COMMAND(packet, hci_pin_code_request_reply)){
634         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_REPLY);
635     }
636     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)){
637         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_NEGATIVE_REPLY);
638     }
639 
640     // accept connection
641 
642     // reject connection
643 
644     // close_connection?
645       // set state = SENT_DISCONNECT
646 
647     hci_stack.num_cmd_packets--;
648     return hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
649 }
650 
651 /**
652  * pre: numcmds >= 0 - it's allowed to send a command to the controller
653  */
654 int hci_send_cmd(const hci_cmd_t *cmd, ...){
655     va_list argptr;
656     va_start(argptr, cmd);
657     uint8_t * hci_cmd_buffer = hci_stack.hci_cmd_buffer;
658     uint16_t size = hci_create_cmd_internal(hci_stack.hci_cmd_buffer, cmd, argptr);
659     va_end(argptr);
660     return hci_send_cmd_packet(hci_cmd_buffer, size);
661 }
662 
663 // Create various non-HCI events.
664 // TODO: generalize, use table similar to hci_create_command
665 
666 void hci_emit_state(){
667     uint8_t len = 3;
668     uint8_t event[len];
669     event[0] = BTSTACK_EVENT_STATE;
670     event[1] = len - 3;
671     event[2] = hci_stack.state;
672     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
673     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
674 }
675 
676 void hci_emit_connection_complete(hci_connection_t *conn){
677     uint8_t len = 13;
678     uint8_t event[len];
679     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
680     event[1] = len - 3;
681     event[2] = 0; // status = OK
682     bt_store_16(event, 3, conn->con_handle);
683     bt_flip_addr(&event[5], conn->address);
684     event[11] = 1; // ACL connection
685     event[12] = 0; // encryption disabled
686     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
687     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
688 }
689 
690 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
691     uint8_t len = 4;
692     uint8_t event[len];
693     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
694     event[1] = len - 2;
695     bt_store_16(event, 2, conn->con_handle);
696     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
697     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
698 }
699 
700 void hci_emit_nr_connections_changed(){
701     uint8_t len = 3;
702     uint8_t event[len];
703     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
704     event[1] = len - 2;
705     event[2] = nr_hci_connections();
706     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
707     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
708 }
709 
710 void hci_emit_hci_open_failed(){
711     uint8_t len = 2;
712     uint8_t event[len];
713     event[0] = BTSTACK_EVENT_POWERON_FAILED;
714     event[1] = len - 2;
715     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
716     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
717 }
718 
719 
720 void hci_emit_btstack_version() {
721     uint8_t len = 6;
722     uint8_t event[len];
723     event[0] = BTSTACK_EVENT_VERSION;
724     event[1] = len - 2;
725     event[len++] = BTSTACK_MAJOR;
726     event[len++] = BTSTACK_MINOR;
727     bt_store_16(event, len, BTSTACK_REVISION);
728     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
729     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
730 }
731 
732 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
733     uint8_t len = 3;
734     uint8_t event[len];
735     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
736     event[1] = len - 2;
737     event[2] = enabled;
738     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
739     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
740 }
741