xref: /btstack/src/hci.c (revision 2f89d309d853a98107fc1cd9d86c824425e3ce90)
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 uint16_t hci_max_acl_data_packet_length(){
199     return hci_stack.acl_data_packet_length;
200 }
201 
202 int hci_ready_to_send(hci_con_handle_t handle){
203     return hci_number_free_acl_slots() && hci_number_outgoing_packets(handle) < 2;
204 }
205 
206 int hci_send_acl_packet(uint8_t *packet, int size){
207 
208     // check for free places on BT module
209     if (!hci_number_free_acl_slots()) return -1;
210 
211     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
212     hci_connection_t *connection = connection_for_handle( con_handle);
213     if (!connection) return 0;
214     hci_connection_timestamp(connection);
215 
216     // count packet
217     connection->num_acl_packets_sent++;
218     // log_dbg("hci_send_acl_packet - handle %u, sent %u\n", connection->con_handle, connection->num_acl_packets_sent);
219 
220     // send packet - ignore errors
221     hci_stack.hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
222 
223     return 0;
224 }
225 
226 static void acl_handler(uint8_t *packet, int size){
227 
228     // get info
229     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
230     hci_connection_t *conn      = connection_for_handle(con_handle);
231     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
232     uint16_t acl_length         = READ_ACL_LENGTH(packet);
233 
234     // ignore non-registered handle
235     if (!conn){
236         log_err( "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
237         return;
238     }
239 
240     // update idle timestamp
241     hci_connection_timestamp(conn);
242 
243     // handle different packet types
244     switch (acl_flags & 0x03) {
245 
246         case 0x01: // continuation fragment
247 
248             // sanity check
249             if (conn->acl_recombination_pos == 0) {
250                 log_err( "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
251                 return;
252             }
253 
254             // append fragment payload (header already stored)
255             memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
256             conn->acl_recombination_pos += acl_length;
257 
258             // log_err( "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n",
259             //        acl_length, connection->acl_recombination_pos, connection->acl_recombination_length);
260 
261             // forward complete L2CAP packet if complete.
262             if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
263 
264                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, conn->acl_recombination_buffer, conn->acl_recombination_pos);
265                 // reset recombination buffer
266                 conn->acl_recombination_length = 0;
267                 conn->acl_recombination_pos = 0;
268             }
269             break;
270 
271         case 0x02: { // first fragment
272 
273             // sanity check
274             if (conn->acl_recombination_pos) {
275                 log_err( "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
276                 return;
277             }
278 
279             // peek into L2CAP packet!
280             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
281 
282             // compare fragment size to L2CAP packet size
283             if (acl_length >= l2cap_length + 4){
284 
285                 // forward fragment as L2CAP packet
286                 hci_stack.packet_handler(HCI_ACL_DATA_PACKET, packet, acl_length + 4);
287 
288             } else {
289                 // store first fragment and tweak acl length for complete package
290                 memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
291                 conn->acl_recombination_pos    = acl_length + 4;
292                 conn->acl_recombination_length = l2cap_length;
293                 bt_store_16(conn->acl_recombination_buffer, 2, acl_length +4);
294                 // log_err( "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
295             }
296             break;
297 
298         }
299         default:
300             log_err( "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
301             return;
302     }
303 
304     // execute main loop
305     hci_run();
306 }
307 
308 // avoid huge local variables
309 static device_name_t device_name;
310 static void event_handler(uint8_t *packet, int size){
311     bd_addr_t addr;
312     hci_con_handle_t handle;
313     hci_connection_t * conn;
314     int i;
315     link_key_t link_key;
316 
317     // get num_cmd_packets
318     if (packet[0] == HCI_EVENT_COMMAND_COMPLETE || packet[0] == HCI_EVENT_COMMAND_STATUS){
319         // Get Num_HCI_Command_Packets
320         hci_stack.num_cmd_packets = packet[2];
321     }
322 
323     switch (packet[0]) {
324 
325         case HCI_EVENT_COMMAND_COMPLETE:
326             if (COMMAND_COMPLETE_EVENT(packet, hci_read_buffer_size)){
327                 // from offset 5
328                 // status
329                 hci_stack.acl_data_packet_length = READ_BT_16(packet, 6);
330                 // ignore: SCO data packet len (8)
331                 hci_stack.total_num_acl_packets  = packet[9];
332                 // ignore: total num SCO packets
333                 if (hci_stack.state == HCI_STATE_INITIALIZING){
334                     log_dbg("hci_read_buffer_size: size %u, count %u\n", hci_stack.acl_data_packet_length, hci_stack.total_num_acl_packets);
335                 }
336             }
337             break;
338 
339         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:
340             for (i=0; i<packet[2];i++){
341                 handle = READ_BT_16(packet, 3 + 2*i);
342                 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i);
343                 conn = connection_for_handle(handle);
344                 if (!conn){
345                     log_err("hci_number_completed_packet lists unused con handle %u\n", handle);
346                     continue;
347                 }
348                 conn->num_acl_packets_sent -= num_packets;
349                 // log_dbg("hci_number_completed_packet %u processed for handle %u, outstanding %u\n", num_packets, handle, conn->num_acl_packets_sent);
350             }
351             break;
352 
353         case HCI_EVENT_CONNECTION_REQUEST:
354             bt_flip_addr(addr, &packet[2]);
355             // TODO: eval COD 8-10
356             uint8_t link_type = packet[11];
357             log_dbg("Connection_incoming: "); print_bd_addr(addr); log_dbg(", type %u\n", link_type);
358             if (link_type == 1) { // ACL
359                 conn = connection_for_address(addr);
360                 if (!conn) {
361                     conn = create_connection_for_addr(addr);
362                 }
363                 // TODO: check for malloc failure
364                 conn->state = ACCEPTED_CONNECTION_REQUEST;
365                 hci_send_cmd(&hci_accept_connection_request, addr, 1);
366             } else {
367                 // TODO: decline request
368             }
369             break;
370 
371         case HCI_EVENT_CONNECTION_COMPLETE:
372             // Connection management
373             bt_flip_addr(addr, &packet[5]);
374             log_dbg("Connection_complete (status=%u)", packet[2]); print_bd_addr(addr); log_dbg("\n");
375             conn = connection_for_address(addr);
376             if (conn) {
377                 if (!packet[2]){
378                     conn->state = OPEN;
379                     conn->con_handle = READ_BT_16(packet, 3);
380 
381                     gettimeofday(&conn->timestamp, NULL);
382                     run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
383                     run_loop_add_timer(&conn->timeout);
384 
385                     log_dbg("New connection: handle %u, ", conn->con_handle);
386                     print_bd_addr( conn->address );
387                     log_dbg("\n");
388 
389                     hci_emit_nr_connections_changed();
390                 } else {
391                     // connection failed, remove entry
392                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
393                     free( conn );
394 
395                     // if authentication error, also delete link key
396                     if (packet[2] == 0x05) {
397                         hci_drop_link_key_for_bd_addr(&addr);
398                     }
399                 }
400             }
401             break;
402 
403         case HCI_EVENT_LINK_KEY_REQUEST:
404             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_REQUEST);
405             if (!hci_stack.remote_device_db) break;
406             bt_flip_addr(addr, &packet[2]);
407             if ( hci_stack.remote_device_db->get_link_key( &addr, &link_key)){
408                 hci_send_cmd(&hci_link_key_request_reply, &addr, &link_key);
409             } else {
410                 hci_send_cmd(&hci_link_key_request_negative_reply, &addr);
411             }
412             // request already answered
413             return;
414 
415         case HCI_EVENT_LINK_KEY_NOTIFICATION:
416             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_LINK_KEY_NOTIFICATION);
417             if (!hci_stack.remote_device_db) break;
418             bt_flip_addr(addr, &packet[2]);
419             hci_stack.remote_device_db->put_link_key(&addr, (link_key_t *) &packet[8]);
420             // still forward event to allow dismiss of pairing dialog
421             break;
422 
423         case HCI_EVENT_PIN_CODE_REQUEST:
424             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], RECV_PIN_CODE_REQUEST);
425             break;
426 
427         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
428             if (!hci_stack.remote_device_db) break;
429             if (packet[2]) break; // status not ok
430             bt_flip_addr(addr, &packet[3]);
431             bzero(&device_name, sizeof(device_name_t));
432             strncpy((char*) device_name, (char*) &packet[9], 248);
433             hci_stack.remote_device_db->put_name(&addr, &device_name);
434             break;
435 
436         case HCI_EVENT_INQUIRY_RESULT:
437         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
438             if (!hci_stack.remote_device_db) break;
439             // first send inq result packet
440             hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
441             // then send cached remote names
442             for (i=0; i<packet[2];i++){
443                 bt_flip_addr(addr, &packet[3+i*6]);
444                 if (hci_stack.remote_device_db->get_name(&addr, &device_name)){
445                     hci_emit_remote_name_cached(&addr, &device_name);
446                 }
447             }
448             return;
449 
450         case HCI_EVENT_DISCONNECTION_COMPLETE:
451             if (!packet[2]){
452                 handle = READ_BT_16(packet, 3);
453                 hci_connection_t * conn = connection_for_handle(handle);
454                 if (conn) {
455                     log_dbg("Connection closed: handle %u, ", conn->con_handle);
456                     print_bd_addr( conn->address );
457                     log_dbg("\n");
458                     run_loop_remove_timer(&conn->timeout);
459                     linked_list_remove(&hci_stack.connections, (linked_item_t *) conn);
460                     free( conn );
461                     hci_emit_nr_connections_changed();
462                 }
463             }
464             break;
465 
466         default:
467             break;
468     }
469 
470     // handle BT initialization
471     if (hci_stack.state == HCI_STATE_INITIALIZING){
472         // handle H4 synchronization loss on restart
473         // if (hci_stack.substate == 1 && packet[0] == HCI_EVENT_HARDWARE_ERROR){
474         //    hci_stack.substate = 0;
475         // }
476         // handle normal init sequence
477         if (hci_stack.substate % 2){
478             // odd: waiting for event
479             if (packet[0] == HCI_EVENT_COMMAND_COMPLETE){
480                 hci_stack.substate++;
481             }
482         }
483     }
484 
485     hci_stack.packet_handler(HCI_EVENT_PACKET, packet, size);
486 
487 	// execute main loop
488 	hci_run();
489 }
490 
491 void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
492     switch (packet_type) {
493         case HCI_EVENT_PACKET:
494             event_handler(packet, size);
495             break;
496         case HCI_ACL_DATA_PACKET:
497             acl_handler(packet, size);
498             break;
499         default:
500             break;
501     }
502 }
503 
504 /** Register HCI packet handlers */
505 void hci_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
506     hci_stack.packet_handler = handler;
507 }
508 
509 void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, remote_device_db_t * remote_device_db){
510 
511     // reference to use transport layer implementation
512     hci_stack.hci_transport = transport;
513 
514     // references to used control implementation
515     hci_stack.control = control;
516 
517     // reference to used config
518     hci_stack.config = config;
519 
520     // no connections yet
521     hci_stack.connections = NULL;
522 
523     // empty cmd buffer
524     hci_stack.hci_cmd_buffer = malloc(3+255);
525 
526     // higher level handler
527     hci_stack.packet_handler = dummy_handler;
528 
529     // store and open remote device db
530     hci_stack.remote_device_db = remote_device_db;
531     if (hci_stack.remote_device_db) {
532         hci_stack.remote_device_db->open();
533     }
534 
535     // register packet handlers with transport
536     transport->register_packet_handler(&packet_handler);
537 }
538 
539 void hci_close(){
540     // close remote device db
541     if (hci_stack.remote_device_db) {
542         hci_stack.remote_device_db->close();
543     }
544 }
545 
546 int hci_power_control(HCI_POWER_MODE power_mode){
547     if (power_mode == HCI_POWER_ON && hci_stack.state == HCI_STATE_OFF) {
548 
549         // power on
550         int err = 0;
551         if (hci_stack.control && hci_stack.control->on){
552             err = (*hci_stack.control->on)(hci_stack.config);
553         }
554         if (err){
555             log_err( "POWER_ON failed\n");
556             hci_emit_hci_open_failed();
557             return err;
558         }
559 
560         // open low-level device
561         err = hci_stack.hci_transport->open(hci_stack.config);
562         if (err){
563             log_err( "HCI_INIT failed, turning Bluetooth off again\n");
564             if (hci_stack.control && hci_stack.control->off){
565                 (*hci_stack.control->off)(hci_stack.config);
566             }
567             hci_emit_hci_open_failed();
568             return err;
569         }
570 
571         // set up state machine
572         hci_stack.num_cmd_packets = 1; // assume that one cmd can be sent
573         hci_stack.state = HCI_STATE_INITIALIZING;
574         hci_stack.substate = 0;
575 
576     } else if (power_mode == HCI_POWER_OFF && hci_stack.state == HCI_STATE_WORKING){
577 
578         // close low-level device
579         hci_stack.hci_transport->close(hci_stack.config);
580 
581         // power off
582         if (hci_stack.control && hci_stack.control->off){
583             (*hci_stack.control->off)(hci_stack.config);
584         }
585 
586         // we're off now
587         hci_stack.state = HCI_STATE_OFF;
588     }
589 
590     // create internal event
591 	hci_emit_state();
592 
593 	// trigger next/first action
594 	hci_run();
595 
596     return 0;
597 }
598 
599 void hci_run(){
600 
601     switch (hci_stack.state){
602         case HCI_STATE_INITIALIZING:
603             if (hci_stack.substate % 2) {
604                 // odd: waiting for command completion
605                 return;
606             }
607             if (hci_stack.num_cmd_packets == 0) {
608                 // cannot send command yet
609                 return;
610             }
611             switch (hci_stack.substate >> 1){
612                 case 0:
613                     hci_send_cmd(&hci_reset);
614                     break;
615                 case 1:
616                     // custom initialization
617                     if (hci_stack.control && hci_stack.control->next_command){
618                         uint8_t * cmd = (*hci_stack.control->next_command)(hci_stack.config);
619                         if (cmd) {
620                             int size = 3 + cmd[2];
621                             hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, cmd, size);
622                             hci_stack.substate = 0; // more init commands
623                             break;
624                         }
625                     }
626                     // otherwise continue
627 					hci_send_cmd(&hci_read_bd_addr);
628 					break;
629 				case 2:
630 					hci_send_cmd(&hci_read_buffer_size);
631 					break;
632                 case 3:
633                     // ca. 15 sec
634                     hci_send_cmd(&hci_write_page_timeout, 0x6000);
635                     break;
636 				case 4:
637 					hci_send_cmd(&hci_write_scan_enable, 3); // 3 inq scan + page scan
638 					break;
639                 case 5:
640 #ifndef EMBEDDED
641                 {
642                     char hostname[30];
643                     gethostname(hostname, 30);
644                     hostname[29] = '\0';
645                     hci_send_cmd(&hci_write_local_name, hostname);
646                     break;
647                 }
648                 case 6:
649 #endif
650                     // done.
651                     hci_stack.state = HCI_STATE_WORKING;
652                     hci_emit_state();
653                     break;
654                 default:
655                     break;
656             }
657             hci_stack.substate++;
658             break;
659         default:
660             break;
661     }
662 }
663 
664 int hci_send_cmd_packet(uint8_t *packet, int size){
665     bd_addr_t addr;
666     hci_connection_t * conn;
667     // house-keeping
668 
669     // create_connection?
670     if (IS_COMMAND(packet, hci_create_connection)){
671         bt_flip_addr(addr, &packet[3]);
672         log_dbg("Create_connection to "); print_bd_addr(addr); log_dbg("\n");
673         conn = connection_for_address(addr);
674         if (conn) {
675             // if connection exists
676             if (conn->state == OPEN) {
677                 // if OPEN, emit connection complete command
678                 hci_emit_connection_complete(conn);
679             }
680             //    otherwise, just ignore
681             return 0; // don't sent packet to controller
682 
683         } else{
684             conn = create_connection_for_addr(addr);
685             if (conn){
686                 //    create connection struct and register, state = SENT_CREATE_CONNECTION
687                 conn->state = SENT_CREATE_CONNECTION;
688             }
689         }
690     }
691 
692     if (IS_COMMAND(packet, hci_link_key_request_reply)){
693         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_REPLY);
694     }
695     if (IS_COMMAND(packet, hci_link_key_request_negative_reply)){
696         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_LINK_KEY_NEGATIVE_REQUEST);
697     }
698     if (IS_COMMAND(packet, hci_pin_code_request_reply)){
699         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_REPLY);
700     }
701     if (IS_COMMAND(packet, hci_pin_code_request_negative_reply)){
702         hci_add_connection_flags_for_flipped_bd_addr(&packet[3], SENT_PIN_CODE_NEGATIVE_REPLY);
703     }
704 
705     if (IS_COMMAND(packet, hci_delete_stored_link_key)){
706         if (hci_stack.remote_device_db){
707             bt_flip_addr(addr, &packet[3]);
708             hci_stack.remote_device_db->delete_link_key(&addr);
709         }
710     }
711 
712     hci_stack.num_cmd_packets--;
713     return hci_stack.hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
714 }
715 
716 /**
717  * pre: numcmds >= 0 - it's allowed to send a command to the controller
718  */
719 int hci_send_cmd(const hci_cmd_t *cmd, ...){
720     va_list argptr;
721     va_start(argptr, cmd);
722     uint8_t * hci_cmd_buffer = hci_stack.hci_cmd_buffer;
723     uint16_t size = hci_create_cmd_internal(hci_stack.hci_cmd_buffer, cmd, argptr);
724     va_end(argptr);
725     return hci_send_cmd_packet(hci_cmd_buffer, size);
726 }
727 
728 // Create various non-HCI events.
729 // TODO: generalize, use table similar to hci_create_command
730 
731 void hci_emit_state(){
732     uint8_t len = 3;
733     uint8_t event[len];
734     event[0] = BTSTACK_EVENT_STATE;
735     event[1] = len - 3;
736     event[2] = hci_stack.state;
737     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
738     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
739 }
740 
741 void hci_emit_connection_complete(hci_connection_t *conn){
742     uint8_t len = 13;
743     uint8_t event[len];
744     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
745     event[1] = len - 3;
746     event[2] = 0; // status = OK
747     bt_store_16(event, 3, conn->con_handle);
748     bt_flip_addr(&event[5], conn->address);
749     event[11] = 1; // ACL connection
750     event[12] = 0; // encryption disabled
751     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
752     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
753 }
754 
755 void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
756     uint8_t len = 4;
757     uint8_t event[len];
758     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
759     event[1] = len - 2;
760     bt_store_16(event, 2, conn->con_handle);
761     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
762     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
763 }
764 
765 void hci_emit_nr_connections_changed(){
766     uint8_t len = 3;
767     uint8_t event[len];
768     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
769     event[1] = len - 2;
770     event[2] = nr_hci_connections();
771     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
772     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
773 }
774 
775 void hci_emit_hci_open_failed(){
776     uint8_t len = 2;
777     uint8_t event[len];
778     event[0] = BTSTACK_EVENT_POWERON_FAILED;
779     event[1] = len - 2;
780     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
781     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
782 }
783 
784 
785 void hci_emit_btstack_version() {
786     uint8_t len = 6;
787     uint8_t event[len];
788     event[0] = BTSTACK_EVENT_VERSION;
789     event[1] = len - 2;
790     event[len++] = BTSTACK_MAJOR;
791     event[len++] = BTSTACK_MINOR;
792     bt_store_16(event, len, BTSTACK_REVISION);
793     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
794     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
795 }
796 
797 void hci_emit_system_bluetooth_enabled(uint8_t enabled){
798     uint8_t len = 3;
799     uint8_t event[len];
800     event[0] = BTSTACK_EVENT_SYSTEM_BLUETOOTH_ENABLED;
801     event[1] = len - 2;
802     event[2] = enabled;
803     hci_dump_packet( HCI_EVENT_PACKET, 0, event, len);
804     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
805 }
806 
807 void hci_emit_remote_name_cached(bd_addr_t *addr, device_name_t *name){
808     uint16_t len = 2+1+6+248;
809     uint8_t event[len];
810     event[0] = BTSTACK_EVENT_REMOTE_NAME_CACHED;
811     event[1] = len - 2;
812     event[2] = 0;   // just to be compatible with HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
813     bt_flip_addr(&event[3], *addr);
814     memcpy(&event[9], name, 248);
815     hci_dump_packet(HCI_EVENT_PACKET, 0, event, len);
816     hci_stack.packet_handler(HCI_EVENT_PACKET, event, len);
817 }
818