xref: /btstack/src/classic/hfp_ag.c (revision cbf509016daa1295a6a8b22d7314db50b88c6c9a)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hfp_ag.c"
39 
40 // *****************************************************************************
41 //
42 // HFP Audio Gateway (AG) unit
43 //
44 // *****************************************************************************
45 
46 #include "btstack_config.h"
47 
48 #include <stdint.h>
49 #include <stdio.h>
50 #include <string.h>
51 
52 #include "hci_cmd.h"
53 #include "btstack_run_loop.h"
54 
55 #include "bluetooth_sdp.h"
56 #include "hci.h"
57 #include "btstack_memory.h"
58 #include "hci_dump.h"
59 #include "l2cap.h"
60 #include "btstack_debug.h"
61 #include "btstack_event.h"
62 #include "classic/core.h"
63 #include "classic/hfp.h"
64 #include "classic/hfp_ag.h"
65 #include "classic/hfp_gsm_model.h"
66 #include "classic/sdp_client_rfcomm.h"
67 #include "classic/sdp_server.h"
68 #include "classic/sdp_util.h"
69 
70 // private prototypes
71 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection);
72 static void hfp_ag_hf_start_ringing_incoming(hfp_connection_t * hfp_connection);
73 static void hfp_ag_hf_start_ringing_outgoing(hfp_connection_t * hfp_connection);
74 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection);
75 
76 // public prototypes
77 hfp_generic_status_indicator_t * get_hfp_generic_status_indicators(void);
78 int get_hfp_generic_status_indicators_nr(void);
79 void set_hfp_generic_status_indicators(hfp_generic_status_indicator_t * indicators, int indicator_nr);
80 void set_hfp_ag_indicators(hfp_ag_indicator_t * indicators, int indicator_nr);
81 int get_hfp_ag_indicators_nr(hfp_connection_t * context);
82 hfp_ag_indicator_t * get_hfp_ag_indicators(hfp_connection_t * context);
83 
84 #define HFP_SUBEVENT_INVALID 0xFFFF
85 
86 // const
87 static const char hfp_ag_default_service_name[] = "Voice gateway";
88 
89 // globals
90 
91 // higher layer callbacks
92 static btstack_packet_handler_t hfp_ag_callback;
93 
94 static bool (*hfp_ag_custom_call_sm_handler)(hfp_ag_call_event_t event);
95 
96 static btstack_packet_callback_registration_t hfp_ag_hci_event_callback_registration;
97 
98 static uint16_t hfp_ag_supported_features;
99 
100 // codecs
101 static uint8_t hfp_ag_codecs_nr;
102 static uint8_t hfp_ag_codecs[HFP_MAX_NUM_CODECS];
103 
104 // AG indicators
105 static int                hfp_ag_indicators_nr;
106 static hfp_ag_indicator_t hfp_ag_indicators[HFP_MAX_NUM_INDICATORS];
107 
108 // generic status indicators
109 static int                            hfp_ag_generic_status_indicators_nr;
110 static hfp_generic_status_indicator_t hfp_ag_generic_status_indicators[HFP_MAX_NUM_INDICATORS];
111 
112 static int    hfp_ag_call_hold_services_nr;
113 static char * hfp_ag_call_hold_services[6];
114 
115 static hfp_response_and_hold_state_t hfp_ag_response_and_hold_state;
116 static bool hfp_ag_response_and_hold_active = false;
117 
118 // Subscriber information entries
119 static hfp_phone_number_t * hfp_ag_subscriber_numbers;
120 static int                  hfp_ag_subscriber_numbers_count;
121 
122 // call state
123 static btstack_timer_source_t hfp_ag_ring_timeout;
124 
125 // code
126 static int hfp_ag_get_ag_indicators_nr(hfp_connection_t * hfp_connection){
127     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
128         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
129         (void)memcpy(hfp_connection->ag_indicators, hfp_ag_indicators,
130                      hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
131     }
132     return hfp_connection->ag_indicators_nr;
133 }
134 
135 hfp_ag_indicator_t * hfp_ag_get_ag_indicators(hfp_connection_t * hfp_connection){
136     // TODO: save only value, and value changed in the hfp_connection?
137     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
138         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
139         (void)memcpy(hfp_connection->ag_indicators, hfp_ag_indicators,
140                      hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
141     }
142     return (hfp_ag_indicator_t *)&(hfp_connection->ag_indicators);
143 }
144 
145 static hfp_ag_indicator_t * get_ag_indicator_for_name(const char * name){
146     int i;
147     for (i = 0; i < hfp_ag_indicators_nr; i++){
148         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
149             return &hfp_ag_indicators[i];
150         }
151     }
152     return NULL;
153 }
154 
155 static int get_ag_indicator_index_for_name(const char * name){
156     int i;
157     for (i = 0; i < hfp_ag_indicators_nr; i++){
158         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
159             return i;
160         }
161     }
162     return -1;
163 }
164 
165 static hfp_connection_t * get_hfp_ag_connection_context_for_acl_handle(uint16_t handle){
166     btstack_linked_list_iterator_t it;
167     btstack_linked_list_iterator_init(&it, hfp_get_connections());
168     while (btstack_linked_list_iterator_has_next(&it)){
169         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
170         if (hfp_connection->acl_handle != handle)      continue;
171         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
172         return hfp_connection;
173     }
174     return NULL;
175 }
176 
177 static int use_in_band_tone(void){
178     return get_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE);
179 }
180 
181 static int has_codec_negotiation_feature(hfp_connection_t * hfp_connection){
182     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_CODEC_NEGOTIATION);
183     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_CODEC_NEGOTIATION);
184     return hf && ag;
185 }
186 
187 static int has_call_waiting_and_3way_calling_feature(hfp_connection_t * hfp_connection){
188     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_THREE_WAY_CALLING);
189     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_THREE_WAY_CALLING);
190     return hf && ag;
191 }
192 
193 static int has_hf_indicators_feature(hfp_connection_t * hfp_connection){
194     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_HF_INDICATORS);
195     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_HF_INDICATORS);
196     return hf && ag;
197 }
198 
199 /* unsolicited responses */
200 
201 static int hfp_ag_send_change_in_band_ring_tone_setting_cmd(uint16_t cid){
202     char buffer[20];
203     snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n",
204              HFP_CHANGE_IN_BAND_RING_TONE_SETTING, use_in_band_tone());
205     buffer[sizeof(buffer) - 1] = 0;
206     return send_str_over_rfcomm(cid, buffer);
207 }
208 
209 static int hfp_ag_exchange_supported_features_cmd(uint16_t cid){
210     char buffer[40];
211     snprintf(buffer, sizeof(buffer), "\r\n%s:%d\r\n\r\nOK\r\n",
212              HFP_SUPPORTED_FEATURES, hfp_ag_supported_features);
213     buffer[sizeof(buffer) - 1] = 0;
214     return send_str_over_rfcomm(cid, buffer);
215 }
216 
217 static int hfp_ag_send_ok(uint16_t cid){
218     char buffer[10];
219     snprintf(buffer, sizeof(buffer), "\r\nOK\r\n");
220     buffer[sizeof(buffer) - 1] = 0;
221     return send_str_over_rfcomm(cid, buffer);
222 }
223 
224 static int hfp_ag_send_ring(uint16_t cid){
225     return send_str_over_rfcomm(cid, (char *) "\r\nRING\r\n");
226 }
227 
228 static int hfp_ag_send_no_carrier(uint16_t cid){
229     char buffer[15];
230     snprintf(buffer, sizeof(buffer), "\r\nNO CARRIER\r\n");
231     buffer[sizeof(buffer) - 1] = 0;
232     return send_str_over_rfcomm(cid, buffer);
233 }
234 
235 static int hfp_ag_send_clip(uint16_t cid){
236     char buffer[50];
237     snprintf(buffer, sizeof(buffer), "\r\n%s: \"%s\",%u\r\n", HFP_ENABLE_CLIP,
238              hfp_gsm_clip_number(), hfp_gsm_clip_type());
239     buffer[sizeof(buffer) - 1] = 0;
240     return send_str_over_rfcomm(cid, buffer);
241 }
242 
243 static int hfp_send_subscriber_number_cmd(uint16_t cid, uint8_t type, const char * number){
244     char buffer[50];
245     snprintf(buffer, sizeof(buffer), "\r\n%s: ,\"%s\",%u, , \r\n",
246              HFP_SUBSCRIBER_NUMBER_INFORMATION, number, type);
247     buffer[sizeof(buffer) - 1] = 0;
248     return send_str_over_rfcomm(cid, buffer);
249 }
250 
251 static int hfp_ag_send_phone_number_for_voice_tag_cmd(uint16_t cid){
252     char buffer[50];
253     snprintf(buffer, sizeof(buffer), "\r\n%s: %s\r\n",
254              HFP_PHONE_NUMBER_FOR_VOICE_TAG, hfp_gsm_clip_number());
255     buffer[sizeof(buffer) - 1] = 0;
256     return send_str_over_rfcomm(cid, buffer);
257 }
258 
259 static int hfp_ag_send_call_waiting_notification(uint16_t cid){
260     char buffer[50];
261     snprintf(buffer, sizeof(buffer), "\r\n%s: \"%s\",%u\r\n",
262              HFP_ENABLE_CALL_WAITING_NOTIFICATION, hfp_gsm_clip_number(),
263              hfp_gsm_clip_type());
264     buffer[sizeof(buffer) - 1] = 0;
265     return send_str_over_rfcomm(cid, buffer);
266 }
267 
268 static int hfp_ag_send_error(uint16_t cid){
269     char buffer[10];
270     snprintf(buffer, sizeof(buffer), "\r\nERROR\r\n");
271     buffer[sizeof(buffer) - 1] = 0;
272     return send_str_over_rfcomm(cid, buffer);
273 }
274 
275 static int hfp_ag_send_report_extended_audio_gateway_error(uint16_t cid, uint8_t error){
276     char buffer[20];
277     snprintf(buffer, sizeof(buffer), "\r\n%s=%d\r\n",
278              HFP_EXTENDED_AUDIO_GATEWAY_ERROR, error);
279     buffer[sizeof(buffer) - 1] = 0;
280     return send_str_over_rfcomm(cid, buffer);
281 }
282 
283 // get size for indicator string
284 static int hfp_ag_indicators_string_size(hfp_connection_t * hfp_connection, int i){
285     // template: ("$NAME",($MIN,$MAX))
286     return 8 + (int) strlen(hfp_ag_get_ag_indicators(hfp_connection)[i].name)
287          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range)
288          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range);
289 }
290 
291 // store indicator
292 static void hfp_ag_indicators_string_store(hfp_connection_t * hfp_connection, int i, uint8_t * buffer, uint16_t buffer_size){
293     snprintf((char *)buffer, buffer_size, "(\"%s\",(%d,%d)),",
294              hfp_ag_get_ag_indicators(hfp_connection)[i].name,
295              hfp_ag_get_ag_indicators(hfp_connection)[i].min_range,
296              hfp_ag_get_ag_indicators(hfp_connection)[i].max_range);
297     ((char *)buffer)[buffer_size - 1] = 0;
298 }
299 
300 // structure: header [indicator [comma indicator]] footer
301 static int hfp_ag_indicators_cmd_generator_num_segments(hfp_connection_t * hfp_connection){
302     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
303     if (!num_indicators) return 2;
304     return 3 + ((num_indicators-1) * 2);
305 }
306 
307 // get size of individual segment for hfp_ag_retrieve_indicators_cmd
308 static int hfp_ag_indicators_cmd_generator_get_segment_len(hfp_connection_t * hfp_connection, int index){
309     if (index == 0) {
310         return (uint16_t) strlen(HFP_INDICATOR) + 3;   // "\n\r%s:""
311     }
312     index--;
313     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
314     int indicator_index = index >> 1;
315     if ((index & 1) == 0){
316         return hfp_ag_indicators_string_size(hfp_connection, indicator_index);
317     }
318     if (indicator_index == (num_indicators - 1)){
319         return 8; // "\r\n\r\nOK\r\n"
320     }
321     return 1; // comma
322 }
323 
324 static void hfp_ag_indicators_cmd_generator_store_segment(hfp_connection_t * hfp_connection, int index, uint8_t * buffer, uint16_t buffer_size){
325     if (index == 0){
326         *buffer++ = '\r';
327         *buffer++ = '\n';
328         int len = (uint16_t) strlen(HFP_INDICATOR);
329         (void)memcpy(buffer, HFP_INDICATOR, len);
330         buffer += len;
331         *buffer++ = ':';
332         return;
333     }
334     index--;
335     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
336     int indicator_index = index >> 1;
337     if ((index & 1) == 0){
338         hfp_ag_indicators_string_store(hfp_connection, indicator_index, buffer, buffer_size);
339         return;
340     }
341     if (indicator_index == (num_indicators-1)){
342         (void)memcpy(buffer, "\r\n\r\nOK\r\n", 8);
343         return;
344     }
345     *buffer = ',';
346 }
347 
348 static int hfp_ag_generic_indicators_join(char * buffer, int buffer_size){
349     if (buffer_size < (hfp_ag_indicators_nr * 3)) return 0;
350     int i;
351     int offset = 0;
352     for (i = 0; i < (hfp_ag_generic_status_indicators_nr - 1); i++) {
353         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_ag_generic_status_indicators[i].uuid);
354     }
355     if (i < hfp_ag_generic_status_indicators_nr){
356         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_ag_generic_status_indicators[i].uuid);
357     }
358     return offset;
359 }
360 
361 static int hfp_ag_generic_indicators_initial_status_join(char * buffer, int buffer_size){
362     if (buffer_size < (hfp_ag_generic_status_indicators_nr * 3)) return 0;
363     int i;
364     int offset = 0;
365     for (i = 0; i < hfp_ag_generic_status_indicators_nr; i++) {
366         offset += snprintf(buffer+offset, buffer_size-offset, "\r\n%s:%d,%d\r\n", HFP_GENERIC_STATUS_INDICATOR, hfp_ag_generic_status_indicators[i].uuid, hfp_ag_generic_status_indicators[i].state);
367     }
368     return offset;
369 }
370 
371 static int hfp_ag_indicators_status_join(char * buffer, int buffer_size){
372     if (buffer_size < (hfp_ag_indicators_nr * 3)) return 0;
373     int i;
374     int offset = 0;
375     for (i = 0; i < (hfp_ag_indicators_nr-1); i++) {
376         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_ag_indicators[i].status);
377     }
378     if (i<hfp_ag_indicators_nr){
379         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_ag_indicators[i].status);
380     }
381     return offset;
382 }
383 
384 static int hfp_ag_call_services_join(char * buffer, int buffer_size){
385     if (buffer_size < (hfp_ag_call_hold_services_nr * 3)) return 0;
386     int i;
387     int offset = snprintf(buffer, buffer_size, "(");
388     for (i = 0; i < (hfp_ag_call_hold_services_nr-1); i++) {
389         offset += snprintf(buffer+offset, buffer_size-offset, "%s,", hfp_ag_call_hold_services[i]);
390     }
391     if (i<hfp_ag_call_hold_services_nr){
392         offset += snprintf(buffer+offset, buffer_size-offset, "%s)", hfp_ag_call_hold_services[i]);
393     }
394     return offset;
395 }
396 
397 static int hfp_ag_send_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection,
398     int start_segment, int num_segments,
399     int (*get_segment_len)(hfp_connection_t * hfp_connection, int segment),
400     void (*store_segment) (hfp_connection_t * hfp_connection, int segment, uint8_t * buffer, uint16_t buffer_size)){
401 
402     // assumes: can send now == true
403     // assumes: num segments > 0
404     // assumes: individual segments are smaller than MTU
405     rfcomm_reserve_packet_buffer();
406     int mtu = rfcomm_get_max_frame_size(cid);
407     uint8_t * data = rfcomm_get_outgoing_buffer();
408     int offset = 0;
409     int segment = start_segment;
410     while (segment < num_segments){
411         int segment_len = get_segment_len(hfp_connection, segment);
412         if ((offset + segment_len + 1) > mtu) break;
413         // append segment. As it appends a '\0', we provide a buffer one byte larger
414         store_segment(hfp_connection, segment, data+offset, segment_len + 1);
415         offset += segment_len;
416         segment++;
417     }
418     rfcomm_send_prepared(cid, offset);
419 #ifdef ENABLE_HFP_AT_MESSAGES
420     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_SENT, (char *) data);
421 #endif
422     return segment;
423 }
424 
425 // returns next segment to store
426 static int hfp_ag_send_retrieve_indicators_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection, int start_segment){
427     int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
428     return hfp_ag_send_cmd_via_generator(cid, hfp_connection, start_segment, num_segments,
429                                          hfp_ag_indicators_cmd_generator_get_segment_len,
430                                          hfp_ag_indicators_cmd_generator_store_segment);
431 }
432 
433 static int hfp_ag_send_retrieve_indicators_status_cmd(uint16_t cid){
434     char buffer[40];
435     const int size = sizeof(buffer);
436     int offset = snprintf(buffer, size, "\r\n%s:", HFP_INDICATOR);
437     offset += hfp_ag_indicators_status_join(buffer+offset, size-offset-9);
438     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
439     return send_str_over_rfcomm(cid, buffer);
440 }
441 
442 static int hfp_ag_send_retrieve_can_hold_call_cmd(uint16_t cid){
443     char buffer[40];
444     const int size = sizeof(buffer);
445     int offset = snprintf(buffer, size, "\r\n%s:", HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES);
446     offset += hfp_ag_call_services_join(buffer+offset, size-offset-9);
447     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
448     return send_str_over_rfcomm(cid, buffer);
449 }
450 
451 
452 static int hfp_ag_send_list_supported_generic_status_indicators_cmd(uint16_t cid){
453     return hfp_ag_send_ok(cid);
454 }
455 
456 static int hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(uint16_t cid){
457     char buffer[40];
458     const int size = sizeof(buffer);
459     int offset = snprintf(buffer, size, "\r\n%s:(", HFP_GENERIC_STATUS_INDICATOR);
460     offset += hfp_ag_generic_indicators_join(buffer + offset, size - offset - 10);
461     offset += snprintf(buffer+offset, size-offset, ")\r\n\r\nOK\r\n");
462     return send_str_over_rfcomm(cid, buffer);
463 }
464 
465 static int hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(uint16_t cid){
466     char buffer[40];
467     int offset = hfp_ag_generic_indicators_initial_status_join(buffer, sizeof(buffer) - 7);
468     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\nOK\r\n");
469     return send_str_over_rfcomm(cid, buffer);
470 }
471 
472 static int hfp_ag_send_transfer_ag_indicators_status_cmd(uint16_t cid, hfp_ag_indicator_t * indicator){
473     char buffer[20];
474     snprintf(buffer, sizeof(buffer), "\r\n%s:%d,%d\r\n",
475              HFP_TRANSFER_AG_INDICATOR_STATUS, indicator->index,
476              indicator->status);
477     buffer[sizeof(buffer) - 1] = 0;
478     return send_str_over_rfcomm(cid, buffer);
479 }
480 
481 static int hfp_ag_send_report_network_operator_name_cmd(uint16_t cid, hfp_network_opearator_t op){
482     char buffer[41];
483     if (strlen(op.name) == 0){
484         snprintf(buffer, sizeof(buffer), "\r\n%s:%d,,\r\n\r\nOK\r\n", HFP_QUERY_OPERATOR_SELECTION, op.mode);
485     } else {
486         int offset = snprintf(buffer,  sizeof(buffer), "\r\n%s:%d,%d,", HFP_QUERY_OPERATOR_SELECTION, op.mode, op.format);
487         offset += snprintf(buffer+offset, 16, "%s", op.name);
488         snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n\r\nOK\r\n");
489     }
490     return send_str_over_rfcomm(cid, buffer);
491 }
492 
493 static inline int hfp_ag_send_cmd_with_space_and_int(uint16_t cid, const char * cmd, uint8_t value){
494     char buffer[30];
495     snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n", cmd, value);
496     return send_str_over_rfcomm(cid, buffer);
497 }
498 
499 
500 static inline int hfp_ag_send_cmd_with_int(uint16_t cid, const char * cmd, uint8_t value){
501     char buffer[30];
502     snprintf(buffer, sizeof(buffer), "\r\n%s:%d\r\n", cmd, value);
503     return send_str_over_rfcomm(cid, buffer);
504 }
505 
506 static int hfp_ag_send_suggest_codec_cmd(uint16_t cid, uint8_t codec){
507     return hfp_ag_send_cmd_with_int(cid, HFP_CONFIRM_COMMON_CODEC, codec);
508 }
509 
510 static int hfp_ag_send_set_speaker_gain_cmd(uint16_t cid, uint8_t gain){
511     return hfp_ag_send_cmd_with_int(cid, HFP_SET_SPEAKER_GAIN, gain);
512 }
513 
514 static int hfp_ag_send_set_microphone_gain_cmd(uint16_t cid, uint8_t gain){
515     return hfp_ag_send_cmd_with_int(cid, HFP_SET_MICROPHONE_GAIN, gain);
516 }
517 
518 static int hfp_ag_send_set_response_and_hold(uint16_t cid, int state){
519     return hfp_ag_send_cmd_with_space_and_int(cid, HFP_RESPONSE_AND_HOLD, state);
520 }
521 
522 static int hfp_ag_send_enhanced_voice_recognition_state_cmd(hfp_connection_t * hfp_connection){
523     char buffer[30];
524     uint8_t evra_enabled = hfp_connection->enhanced_voice_recognition_enabled ? 1 : 0;
525     snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, evra_enabled, hfp_connection->ag_vra_state);
526     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
527 }
528 
529 static int hfp_ag_send_voice_recognition_cmd(hfp_connection_t * hfp_connection, uint8_t activate_voice_recognition){
530     char buffer[30];
531     if (hfp_connection->enhanced_voice_recognition_enabled){
532         snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, activate_voice_recognition, hfp_connection->ag_vra_state);
533     } else {
534         snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, activate_voice_recognition);
535     }
536     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
537 }
538 
539 static int hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection_t * hfp_connection){
540     char buffer[HFP_VR_TEXT_HEADER_SIZE + HFP_MAX_VR_TEXT_SIZE];
541     snprintf(buffer, sizeof(buffer), "\r\n%s: 1,%d,%X,%d,%d,\"%s\"\r\n", HFP_ACTIVATE_VOICE_RECOGNITION,
542         hfp_connection->ag_vra_state,
543         hfp_connection->ag_msg.text_id,
544         hfp_connection->ag_msg.text_type,
545         hfp_connection->ag_msg.text_operation,
546         hfp_connection->ag_msg.text);
547     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
548 }
549 
550 static uint8_t hfp_ag_suggest_codec(hfp_connection_t *hfp_connection){
551     if (hfp_connection->sco_for_msbc_failed) return HFP_CODEC_CVSD;
552 
553     if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_ag_codecs_nr, hfp_ag_codecs)){
554         if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_connection->remote_codecs_nr, hfp_connection->remote_codecs)){
555             return HFP_CODEC_MSBC;
556         }
557     }
558     return HFP_CODEC_CVSD;
559 }
560 
561 /* state machines */
562 
563 static uint8_t hfp_ag_esco_s4_supported(hfp_connection_t * hfp_connection){
564     return (hfp_connection->remote_supported_features & (1<<HFP_HFSF_ESCO_S4)) &&  (hfp_ag_supported_features & (1 << HFP_AGSF_ESCO_S4));
565 }
566 
567 static int codecs_exchange_state_machine(hfp_connection_t * hfp_connection){
568     /* events ( == commands):
569         HFP_CMD_AVAILABLE_CODECS == received AT+BAC with list of codecs
570         HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
571             hf_trigger_codec_connection_setup == received BCC
572             ag_trigger_codec_connection_setup == received from AG to send BCS
573         HFP_CMD_HF_CONFIRMED_CODEC == received AT+BCS
574     */
575     switch (hfp_connection->codecs_state){
576         case HFP_CODECS_EXCHANGED:
577             if (hfp_connection->command == HFP_CMD_AVAILABLE_CODECS){
578                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
579                 return 1;
580             }
581             break;
582 
583         case HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE:
584         case HFP_CODECS_AG_RESEND_COMMON_CODEC:
585             hfp_connection->ag_send_common_codec = true;
586             break;
587         default:
588             break;
589     }
590 
591     if (hfp_connection->ag_send_common_codec){
592         hfp_connection->ag_send_common_codec = false;
593         hfp_connection->codecs_state = HFP_CODECS_AG_SENT_COMMON_CODEC;
594         hfp_connection->suggested_codec = hfp_ag_suggest_codec(hfp_connection);
595         hfp_ag_send_suggest_codec_cmd(hfp_connection->rfcomm_cid, hfp_connection->suggested_codec);
596         return 1;
597     }
598 
599     switch (hfp_connection->command){
600         case HFP_CMD_AVAILABLE_CODECS:
601             if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED){
602                 hfp_connection->codecs_state = HFP_CODECS_RECEIVED_LIST;
603                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
604                 return 1;
605             }
606 
607             switch (hfp_connection->codecs_state){
608                 case HFP_CODECS_AG_SENT_COMMON_CODEC:
609                     hfp_connection->codecs_state = HFP_CODECS_AG_RESEND_COMMON_CODEC;
610                     break;
611                 default:
612                     break;
613             }
614             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
615             return 1;
616 
617         case HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
618             hfp_connection->codecs_state = HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE;
619             hfp_connection->establish_audio_connection = 1;
620             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
621             return 1;
622 
623         case HFP_CMD_HF_CONFIRMED_CODEC:
624             if (hfp_connection->codec_confirmed != hfp_connection->suggested_codec){
625                 hfp_connection->codecs_state = HFP_CODECS_ERROR;
626                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
627                 return 1;
628             }
629             hfp_connection->negotiated_codec = hfp_connection->codec_confirmed;
630             hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
631             log_info("hfp: codec confirmed: %s", (hfp_connection->negotiated_codec == HFP_CODEC_MSBC) ? "mSBC" : "CVSD");
632             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
633             // now, pick link settings
634             hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
635 #ifdef ENABLE_CC256X_ASSISTED_HFP
636             hfp_cc256x_prepare_for_sco(hfp_connection);
637 #endif
638 #ifdef ENABLE_RTK_PCM_WBS
639             hfp_connection->rtk_send_sco_config = true;
640 #endif
641             return 1;
642         default:
643             break;
644     }
645     return 0;
646 }
647 
648 static void hfp_ag_slc_established(hfp_connection_t * hfp_connection){
649     hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
650     hfp_emit_slc_connection_event(hfp_connection->local_role, 0, hfp_connection->acl_handle, hfp_connection->remote_addr);
651 
652     // HFP 4.35: "When [...] a new Service Level Connection is established all indicators are activated by default."
653     uint16_t i;
654     for (i=0;i<hfp_connection->ag_indicators_nr;i++){
655         hfp_connection->ag_indicators[i].enabled = 1;
656     }
657 
658     // if active call exist, set per-hfp_connection state active, too (when audio is on)
659     if (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT){
660         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
661     }
662     // if AG is ringing, also start ringing on the HF
663     if (hfp_gsm_call_status() == HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS){
664         switch (hfp_gsm_callsetup_status()){
665             case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
666                 hfp_ag_hf_start_ringing_incoming(hfp_connection);
667                 break;
668             case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
669                 hfp_ag_hf_start_ringing_outgoing(hfp_connection);
670                 break;
671             default:
672                 break;
673         }
674     }
675 }
676 
677 static int hfp_ag_run_for_context_service_level_connection(hfp_connection_t * hfp_connection){
678     // log_info("hfp_ag_run_for_context_service_level_connection state %u, command %u", hfp_connection->state, hfp_connection->command);
679     if (hfp_connection->state >= HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) return 0;
680     int sent = 0;
681     switch(hfp_connection->command){
682         case HFP_CMD_SUPPORTED_FEATURES:
683             switch(hfp_connection->state){
684                 case HFP_W4_EXCHANGE_SUPPORTED_FEATURES:
685                 case HFP_EXCHANGE_SUPPORTED_FEATURES:
686                     hfp_hf_drop_mSBC_if_eSCO_not_supported(hfp_ag_codecs, &hfp_ag_codecs_nr);
687                     if (has_codec_negotiation_feature(hfp_connection)){
688                         hfp_connection->state = HFP_W4_NOTIFY_ON_CODECS;
689                     } else {
690                         hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
691                     }
692                     hfp_ag_exchange_supported_features_cmd(hfp_connection->rfcomm_cid);
693                     return 1;
694                 default:
695                     break;
696             }
697             break;
698         case HFP_CMD_AVAILABLE_CODECS:
699             sent = codecs_exchange_state_machine(hfp_connection);
700             if (hfp_connection->codecs_state == HFP_CODECS_RECEIVED_LIST){
701                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
702             }
703             return sent;
704 
705         case HFP_CMD_RETRIEVE_AG_INDICATORS:
706             if (hfp_connection->state == HFP_W4_RETRIEVE_INDICATORS) {
707                 // HF requested AG Indicators and we did expect it
708                 hfp_connection->send_ag_indicators_segment = 0;
709                 hfp_connection->state = HFP_RETRIEVE_INDICATORS;
710                 // continue below in state switch
711             }
712             break;
713 
714         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
715             if (hfp_connection->state != HFP_W4_RETRIEVE_INDICATORS_STATUS) break;
716             hfp_connection->state = HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE;
717             hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
718             return 1;
719 
720         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
721             if (hfp_connection->state != HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE) break;
722             if (has_call_waiting_and_3way_calling_feature(hfp_connection)){
723                 hfp_connection->state = HFP_W4_RETRIEVE_CAN_HOLD_CALL;
724             } else if (has_hf_indicators_feature(hfp_connection)){
725                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
726             } else {
727                 hfp_ag_slc_established(hfp_connection);
728             }
729             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
730             return 1;
731 
732         case HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES:
733             if (hfp_connection->state != HFP_W4_RETRIEVE_CAN_HOLD_CALL) break;
734             if (has_hf_indicators_feature(hfp_connection)){
735                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
736             }
737             hfp_ag_send_retrieve_can_hold_call_cmd(hfp_connection->rfcomm_cid);
738             if (!has_hf_indicators_feature(hfp_connection)){
739                 hfp_ag_slc_established(hfp_connection);
740             }
741             return 1;
742 
743         case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
744             if (hfp_connection->state != HFP_W4_LIST_GENERIC_STATUS_INDICATORS) break;
745             hfp_connection->state = HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS;
746             hfp_ag_send_list_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
747             return 1;
748 
749         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
750             if (hfp_connection->state != HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS) break;
751             hfp_connection->state = HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS;
752             hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
753             return 1;
754 
755         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
756             if (hfp_connection->state != HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS) break;
757             hfp_ag_slc_established(hfp_connection);
758             hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
759             return 1;
760         default:
761             break;
762     }
763 
764     switch (hfp_connection->state){
765         case HFP_RETRIEVE_INDICATORS: {
766             int next_segment = hfp_ag_send_retrieve_indicators_cmd_via_generator(hfp_connection->rfcomm_cid, hfp_connection, hfp_connection->send_ag_indicators_segment);
767             int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
768             log_info("HFP_CMD_RETRIEVE_AG_INDICATORS next segment %u, num_segments %u", next_segment, num_segments);
769             if (next_segment < num_segments){
770                 // prepare sending of next segment
771                 hfp_connection->send_ag_indicators_segment = next_segment;
772                 log_info("HFP_CMD_RETRIEVE_AG_INDICATORS more. command %u, next seg %u", hfp_connection->command, next_segment);
773             } else {
774                 // done, go to next state
775                 hfp_connection->send_ag_indicators_segment = 0;
776                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS_STATUS;
777             }
778             return 1;
779         }
780         default:
781             break;
782     }
783     return 0;
784 }
785 
786 static bool hfp_ag_vra_flag_supported(hfp_connection_t * hfp_connection){
787     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION);
788     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION);
789     return hf && ag;
790 }
791 
792 static bool hfp_ag_enhanced_vra_flag_supported(hfp_connection_t * hfp_connection){
793     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS);
794     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_ENHANCED_VOICE_RECOGNITION_STATUS);
795     return hf && ag;
796 }
797 
798 static bool hfp_ag_can_send_enhanced_vra_message_flag_supported(hfp_connection_t * hfp_connection){
799     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_VOICE_RECOGNITION_TEXT);
800     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_TEXT);
801     return hf && ag;
802 }
803 
804 static bool hfp_ag_can_activate_voice_recognition(hfp_connection_t * hfp_connection){
805     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED || hfp_connection->state > HFP_AUDIO_CONNECTION_ESTABLISHED){
806         return false;
807     }
808     if (hfp_connection->vra_state != HFP_VRA_VOICE_RECOGNITION_OFF){
809         return false;
810     }
811     if (hfp_connection->ag_vra_send_command){
812         return false;
813     }
814     return true;
815 }
816 
817 static bool hfp_ag_voice_recognition_session_active(hfp_connection_t * hfp_connection){
818     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED || hfp_connection->state > HFP_AUDIO_CONNECTION_ESTABLISHED){
819         return false;
820     }
821     if (hfp_connection->vra_state != HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
822         if (hfp_connection->vra_state == HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
823             return true;
824         }
825         return false;
826     }
827     return true;
828 }
829 
830 static bool hfp_ag_is_audio_connection_active(hfp_connection_t * hfp_connection){
831     switch (hfp_connection->state){
832         case HFP_W2_CONNECT_SCO:
833         case HFP_W4_SCO_CONNECTED:
834         case HFP_AUDIO_CONNECTION_ESTABLISHED:
835             return true;
836         default:
837             return false;
838     }
839 }
840 
841 static void hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection_t * hfp_connection, uint8_t status){
842     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
843 
844     uint8_t event[6];
845     event[0] = HCI_EVENT_HFP_META;
846     event[1] = sizeof(event) - 2;
847     event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_AG_MESSAGE_SENT;
848     little_endian_store_16(event, 3, acl_handle);
849     event[5] = status;
850     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
851 }
852 
853 
854 static void hfp_ag_emit_hf_indicator_value(hfp_connection_t * hfp_connection, uint16_t uuid, uint8_t value){
855     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
856 
857     uint8_t event[8];
858     event[0] = HCI_EVENT_HFP_META;
859     event[1] = sizeof(event) - 2;
860     event[2] = HFP_SUBEVENT_HF_INDICATOR;
861     little_endian_store_16(event, 3, acl_handle);
862     little_endian_store_16(event, 5, uuid);
863     event[7] = value;
864     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
865 }
866 
867 static void hfp_ag_emit_general_simple_event(uint8_t event_subtype){
868     if (!hfp_ag_callback) return;
869 
870     uint8_t event[5];
871     event[0] = HCI_EVENT_HFP_META;
872     event[1] = sizeof(event) - 2;
873     event[2] = event_subtype;
874     little_endian_store_16(event, 3, HCI_CON_HANDLE_INVALID);
875     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
876 }
877 
878 // @return status
879 static uint8_t hfp_ag_vra_state_machine_two(hfp_connection_t * hfp_connection){
880     uint8_t status = ERROR_CODE_SUCCESS;
881     switch (hfp_connection->vra_state_requested){
882         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO:
883             if (!hfp_ag_is_audio_connection_active(hfp_connection)){
884                 status = hfp_ag_setup_audio_connection(hfp_connection);
885                 if (status != ERROR_CODE_SUCCESS){
886                     hfp_connection->vra_state_requested = hfp_connection->vra_state;
887                     hfp_emit_voice_recognition_enabled(hfp_connection, status);
888                     break;
889                 }
890             }
891             hfp_connection->enhanced_voice_recognition_enabled = true;
892             hfp_connection->vra_state = HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO;
893             hfp_connection->vra_state_requested = hfp_connection->vra_state;
894             hfp_emit_enhanced_voice_recognition_hf_ready_for_audio_event(hfp_connection, ERROR_CODE_SUCCESS);
895             break;
896 
897         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF:
898             hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_OFF;
899             hfp_connection->vra_state_requested = hfp_connection->vra_state;
900 
901             // release audio connection only if it was opened after audio VR activated
902             if (hfp_ag_is_audio_connection_active(hfp_connection) && !hfp_connection->ag_audio_connection_opened_before_vra){
903                 hfp_trigger_release_audio_connection(hfp_connection);
904             }
905 
906             hfp_emit_voice_recognition_disabled(hfp_connection, ERROR_CODE_SUCCESS);
907             break;
908 
909         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED:
910             // open only if audio connection does not already exist
911             if (!hfp_ag_is_audio_connection_active(hfp_connection)){
912                 status = hfp_ag_setup_audio_connection(hfp_connection);
913                 if (status != ERROR_CODE_SUCCESS){
914                     hfp_connection->vra_state_requested = hfp_connection->vra_state;
915                     hfp_emit_voice_recognition_enabled(hfp_connection, status);
916                     break;
917                 }
918             }
919 
920             hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_ACTIVATED;
921             hfp_connection->vra_state_requested = hfp_connection->vra_state;
922             hfp_connection->enhanced_voice_recognition_enabled = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
923 
924             if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
925                 hfp_emit_voice_recognition_enabled(hfp_connection, ERROR_CODE_SUCCESS);
926             } else {
927                 hfp_connection->emit_vra_enabled_after_audio_established = true;
928             }
929             break;
930 
931         default:
932             break;
933     }
934     return status;
935 }
936 
937 static uint8_t hfp_ag_vra_send_command(hfp_connection_t * hfp_connection){
938     uint8_t done = 0;
939     uint8_t status;
940 
941     switch (hfp_connection->vra_state_requested){
942         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_MSG:
943             done = hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection);
944             if (done == 0){
945                 hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection, ERROR_CODE_UNSPECIFIED_ERROR);
946             } else {
947                 hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection, ERROR_CODE_SUCCESS);
948             }
949             hfp_connection->vra_state_requested = hfp_connection->vra_state;
950             return done;
951 
952         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_STATUS:
953             done = hfp_ag_send_enhanced_voice_recognition_state_cmd(hfp_connection);
954             if (done == 0){
955                 hfp_emit_enhanced_voice_recognition_state_event(hfp_connection, ERROR_CODE_UNSPECIFIED_ERROR);
956             } else {
957                 hfp_emit_enhanced_voice_recognition_state_event(hfp_connection, ERROR_CODE_SUCCESS);
958             }
959             hfp_connection->vra_state_requested = hfp_connection->vra_state;
960             return done;
961 
962         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED:
963         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF:
964             done = hfp_ag_send_voice_recognition_cmd(hfp_connection, hfp_connection->ag_activate_voice_recognition_value);
965             if (done == 0){
966                 hfp_connection->vra_state_requested = hfp_connection->vra_state;
967 
968                 if (hfp_connection->ag_activate_voice_recognition_value == 1){
969                     hfp_emit_voice_recognition_enabled(hfp_connection, done);
970                 } else {
971                     hfp_emit_voice_recognition_disabled(hfp_connection, done);
972                 }
973                 return 0;
974             }
975             status = hfp_ag_vra_state_machine_two(hfp_connection);
976             return (status == ERROR_CODE_SUCCESS) ? 1 : 0;
977 
978         default:
979             log_error("state %u", hfp_connection->vra_state_requested);
980             btstack_assert(false);
981             return 0;
982     }
983 }
984 
985 static int hfp_ag_voice_recognition_state_machine(hfp_connection_t * hfp_connection){
986     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) {
987         return 0;
988     }
989     int done = 0;
990     uint8_t status;
991 
992     // VRA action initiated by AG
993     if (hfp_connection->ag_vra_send_command){
994         hfp_connection->ag_vra_send_command = false;
995         return hfp_ag_vra_send_command(hfp_connection);
996     }
997 
998     if (hfp_connection->ag_vra_requested_by_hf){
999         hfp_connection->ag_vra_requested_by_hf = false;
1000 
1001         // HF initiatied voice recognition, parser extracted activation value
1002         switch (hfp_connection->ag_activate_voice_recognition_value){
1003             case 0:
1004                 if (hfp_ag_voice_recognition_session_active(hfp_connection)){
1005                     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF;
1006                     done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1007                 }
1008                 break;
1009 
1010                 case 1:
1011                     if (hfp_ag_can_activate_voice_recognition(hfp_connection)){
1012                         hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED;
1013                         done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1014                     }
1015                     break;
1016 
1017                     case 2:
1018                         if (hfp_ag_voice_recognition_session_active(hfp_connection)){
1019                             hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO;
1020                             done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1021                         }
1022                         break;
1023                         default:
1024                             break;
1025         }
1026         if (done == 0){
1027             hfp_connection->vra_state_requested = hfp_connection->vra_state;
1028             done = hfp_ag_send_error(hfp_connection->rfcomm_cid);
1029             return 1;
1030         }
1031 
1032         status = hfp_ag_vra_state_machine_two(hfp_connection);
1033         return (status == ERROR_CODE_SUCCESS) ? 1 : 0;
1034     }
1035 
1036     return 0;
1037 }
1038 
1039 static int hfp_ag_run_for_context_service_level_connection_queries(hfp_connection_t * hfp_connection){
1040     int sent = codecs_exchange_state_machine(hfp_connection);
1041     if (sent) return 1;
1042 
1043     if (hfp_connection->ag_send_in_band_ring_tone_setting){
1044         hfp_connection->ag_send_in_band_ring_tone_setting = false;
1045         hfp_ag_send_change_in_band_ring_tone_setting_cmd(hfp_connection->rfcomm_cid);
1046         return 1;
1047     }
1048 
1049     switch(hfp_connection->command){
1050         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1051             hfp_ag_send_report_network_operator_name_cmd(hfp_connection->rfcomm_cid, hfp_connection->network_operator);
1052             return 1;
1053         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
1054             if (hfp_connection->network_operator.format != 0){
1055                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
1056             } else {
1057                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1058             }
1059             return 1;
1060         case HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE:
1061             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1062             return 1;
1063         case HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR:
1064             if (hfp_connection->extended_audio_gateway_error){
1065                 hfp_connection->extended_audio_gateway_error = 0;
1066                 hfp_ag_send_report_extended_audio_gateway_error(hfp_connection->rfcomm_cid, hfp_connection->extended_audio_gateway_error_value);
1067                 return 1;
1068             }
1069             break;
1070         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
1071             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1072             return 1;
1073         default:
1074             break;
1075     }
1076     return 0;
1077 }
1078 
1079 static int hfp_ag_run_for_audio_connection(hfp_connection_t * hfp_connection){
1080     if ((hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) ||
1081         (hfp_connection->state > HFP_W2_DISCONNECT_SCO)) return 0;
1082 
1083     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1084 
1085     if (hfp_connection->release_audio_connection){
1086         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
1087         hfp_connection->release_audio_connection = 0;
1088         gap_disconnect(hfp_connection->sco_handle);
1089         return 1;
1090     }
1091 
1092     // accept incoming audio connection (codec negotiation is not used)
1093     if (hfp_connection->accept_sco){
1094         // notify about codec selection if not done already
1095         if (hfp_connection->negotiated_codec == 0){
1096             hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
1097         }
1098         //
1099         bool incoming_eSCO = hfp_connection->accept_sco == 2;
1100         hfp_connection->accept_sco = 0;
1101         hfp_connection->state = HFP_W4_SCO_CONNECTED;
1102         hfp_accept_synchronous_connection(hfp_connection, incoming_eSCO);
1103         return 1;
1104     }
1105 
1106     // run codecs exchange
1107     int sent = codecs_exchange_state_machine(hfp_connection);
1108     if (sent) return 1;
1109 
1110     if (hfp_connection->codecs_state != HFP_CODECS_EXCHANGED) return 0;
1111     if (hfp_connection->establish_audio_connection){
1112         hfp_connection->state = HFP_W4_SCO_CONNECTED;
1113         hfp_connection->establish_audio_connection = 0;
1114         hfp_setup_synchronous_connection(hfp_connection);
1115         return 1;
1116     }
1117     return 0;
1118 }
1119 
1120 static void hfp_ag_set_callsetup_indicator(void){
1121     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callsetup");
1122     if (!indicator){
1123         log_error("hfp_ag_set_callsetup_indicator: callsetup indicator is missing");
1124         return;
1125     };
1126     indicator->status = hfp_gsm_callsetup_status();
1127 }
1128 
1129 static void hfp_ag_set_callheld_indicator(void){
1130     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callheld");
1131     if (!indicator){
1132         log_error("hfp_ag_set_callheld_state: callheld indicator is missing");
1133         return;
1134     };
1135     indicator->status = hfp_gsm_callheld_status();
1136 }
1137 
1138 //
1139 // transition implementations for hfp_ag_call_state_machine
1140 //
1141 
1142 static void hfp_ag_hf_start_ringing_incoming(hfp_connection_t * hfp_connection){
1143     if (use_in_band_tone()){
1144         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING;
1145         hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1146     } else {
1147         hfp_connection->call_state = HFP_CALL_INCOMING_RINGING;
1148     }
1149 }
1150 
1151 static void hfp_ag_hf_start_ringing_outgoing(hfp_connection_t * hfp_connection){
1152     hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1153 }
1154 
1155 static void hfp_ag_hf_stop_ringing(hfp_connection_t * hfp_connection){
1156     hfp_connection->ag_ring = 0;
1157     hfp_connection->ag_send_clip = 0;
1158 }
1159 
1160 
1161 static void hfp_ag_trigger_incoming_call_during_active_one(void){
1162     btstack_linked_list_iterator_t it;
1163     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1164     while (btstack_linked_list_iterator_has_next(&it)){
1165         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1166         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1167         if (hfp_connection->call_state != HFP_CALL_ACTIVE) continue;
1168 
1169         hfp_connection->call_state = HFP_CALL_W2_SEND_CALL_WAITING;
1170         hfp_ag_run_for_context(hfp_connection);
1171     }
1172 }
1173 
1174 static void hfp_ag_trigger_ring_and_clip(void) {
1175     btstack_linked_list_iterator_t it;
1176     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1177     while (btstack_linked_list_iterator_has_next(&it)){
1178         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1179         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1180         switch (hfp_connection->call_state){
1181             case HFP_CALL_INCOMING_RINGING:
1182             case HFP_CALL_OUTGOING_RINGING:
1183             case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1184                 // Queue RING on this connection
1185                 hfp_connection->ag_ring = 1;
1186 
1187                 // HFP v1.8, 4.23 Calling Line Identification (CLI) Notification
1188                 // "If the calling subscriber number information is available from the network, the AG shall issue the
1189                 // +CLIP unsolicited result code just after every RING indication when the HF is alerted in an incoming call."
1190                 hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
1191 
1192                 // trigger next message
1193                 rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1194                 break;
1195             default:
1196                 break;
1197         }
1198     }
1199 }
1200 
1201 // trigger RING and CLIP messages on connections that are ringing
1202 static void hfp_ag_ring_timeout_handler(btstack_timer_source_t * timer){
1203     hfp_ag_trigger_ring_and_clip();
1204 
1205     btstack_run_loop_set_timer(timer, HFP_RING_PERIOD_MS); // 2 seconds timeout
1206     btstack_run_loop_add_timer(timer);
1207 }
1208 
1209 static void hfp_ag_ring_timeout_stop(void){
1210     btstack_run_loop_remove_timer(&hfp_ag_ring_timeout);
1211 }
1212 
1213 static void hfp_ag_start_ringing(void){
1214     // setup ring timer
1215     btstack_run_loop_remove_timer(&hfp_ag_ring_timeout);
1216     btstack_run_loop_set_timer_handler(&hfp_ag_ring_timeout, hfp_ag_ring_timeout_handler);
1217     btstack_run_loop_set_timer(&hfp_ag_ring_timeout, HFP_RING_PERIOD_MS); // 2 seconds timeout
1218     btstack_run_loop_add_timer(&hfp_ag_ring_timeout);
1219 
1220     // emit start ringing
1221     hfp_ag_emit_general_simple_event(HFP_SUBEVENT_START_RINGING);
1222 
1223     // send initial RING + CLIP
1224     hfp_ag_trigger_ring_and_clip();
1225 }
1226 
1227 static void hfp_ag_stop_ringing(void){
1228     hfp_ag_ring_timeout_stop();
1229     hfp_ag_emit_general_simple_event(HFP_SUBEVENT_STOP_RINGING);
1230 
1231     btstack_linked_list_iterator_t it;
1232     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1233     while (btstack_linked_list_iterator_has_next(&it)){
1234         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1235         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1236         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1237             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1238         hfp_ag_hf_stop_ringing(hfp_connection);
1239     }
1240 }
1241 
1242 static void hfp_ag_trigger_incoming_call_idle(void){
1243     int indicator_index = get_ag_indicator_index_for_name("callsetup");
1244     if (indicator_index < 0) return;
1245 
1246     // update callsetup state in connections
1247     btstack_linked_list_iterator_t it;
1248     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1249     while (btstack_linked_list_iterator_has_next(&it)){
1250         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1251         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1252         if (hfp_connection->call_state != HFP_CALL_IDLE) continue;
1253 
1254         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1255 
1256         hfp_ag_hf_start_ringing_incoming(hfp_connection);
1257 
1258         hfp_ag_run_for_context(hfp_connection);
1259     }
1260 
1261     // start local ringing - started after connection state has been updated
1262     hfp_ag_start_ringing();
1263 }
1264 
1265 static void hfp_ag_trigger_outgoing_call(void){
1266     btstack_linked_list_iterator_t it;
1267     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1268     while (btstack_linked_list_iterator_has_next(&it)){
1269         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1270         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1271         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1272         if (hfp_connection->call_state == HFP_CALL_IDLE){
1273             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1274         }
1275     }
1276 }
1277 
1278 static void hfp_ag_handle_outgoing_call_accepted(hfp_connection_t * hfp_connection){
1279     hfp_connection->call_state = HFP_CALL_OUTGOING_DIALING;
1280 
1281     // trigger callsetup to be
1282     int put_call_on_hold = hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT;
1283     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ACCEPTED, 0, 0, NULL);
1284 
1285     int indicator_index ;
1286 
1287     hfp_ag_set_callsetup_indicator();
1288     indicator_index = get_ag_indicator_index_for_name("callsetup");
1289     hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1290 
1291     // put current call on hold if active
1292     if (put_call_on_hold){
1293         log_info("AG putting current call on hold for new outgoing call");
1294         hfp_ag_set_callheld_indicator();
1295         indicator_index = get_ag_indicator_index_for_name("callheld");
1296         hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[indicator_index]);
1297     }
1298 
1299     // start audio if needed
1300     hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1301 }
1302 
1303 static void hfp_ag_transfer_indicator(const char * name){
1304     int indicator_index = get_ag_indicator_index_for_name(name);
1305     if (indicator_index < 0) return;
1306 
1307     btstack_linked_list_iterator_t it;
1308     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1309     while (btstack_linked_list_iterator_has_next(&it)){
1310         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1311         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1312         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1313         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1314         hfp_ag_run_for_context(hfp_connection);
1315     }
1316 }
1317 
1318 static void hfp_ag_transfer_callsetup_state(void){
1319     hfp_ag_transfer_indicator("callsetup");
1320 }
1321 
1322 static void hfp_ag_transfer_call_state(void){
1323     hfp_ag_transfer_indicator("call");
1324 }
1325 
1326 static void hfp_ag_transfer_callheld_state(void){
1327     hfp_ag_transfer_indicator("callheld");
1328 }
1329 
1330 static void hfp_ag_hf_accept_call(hfp_connection_t * source){
1331     int call_indicator_index = get_ag_indicator_index_for_name("call");
1332     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1333 
1334     hfp_ag_stop_ringing();
1335 
1336     btstack_linked_list_iterator_t it;
1337     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1338     while (btstack_linked_list_iterator_has_next(&it)){
1339         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1340         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1341         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1342             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1343 
1344         if (hfp_connection == source){
1345 
1346             if (use_in_band_tone()){
1347                 hfp_connection->call_state = HFP_CALL_ACTIVE;
1348             } else {
1349                 hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
1350                 hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1351             }
1352 
1353             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1354             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1355 
1356         } else {
1357             hfp_connection->call_state = HFP_CALL_IDLE;
1358         }
1359         hfp_ag_run_for_context(hfp_connection);
1360     }
1361 }
1362 
1363 static void hfp_ag_ag_accept_call(void){
1364     int call_indicator_index = get_ag_indicator_index_for_name("call");
1365     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1366 
1367     hfp_ag_stop_ringing();
1368 
1369     btstack_linked_list_iterator_t it;
1370     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1371     while (btstack_linked_list_iterator_has_next(&it)){
1372         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1373         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1374         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1375             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1376 
1377         hfp_connection->call_state = HFP_CALL_TRIGGER_AUDIO_CONNECTION;
1378 
1379         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1380         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1381 
1382         hfp_ag_run_for_context(hfp_connection);
1383         break;  // only single
1384     }
1385 }
1386 
1387 static void hfp_ag_trigger_reject_call(void){
1388     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1389 
1390     hfp_ag_stop_ringing();
1391 
1392     btstack_linked_list_iterator_t it;
1393     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1394     while (btstack_linked_list_iterator_has_next(&it)){
1395         hfp_connection_t * connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1396         if (connection->local_role != HFP_ROLE_AG) continue;
1397 
1398         switch (connection->call_state){
1399             case HFP_CALL_INCOMING_RINGING:
1400             case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1401             case HFP_CALL_OUTGOING_RINGING:
1402             case HFP_CALL_OUTGOING_INITIATED:
1403             case HFP_CALL_OUTGOING_DIALING:
1404                 break;
1405             default:
1406                 continue;
1407         }
1408 
1409         connection->call_state = HFP_CALL_IDLE;
1410         connection->ag_indicators_status_update_bitmap = store_bit(connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1411 
1412         if (connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1413             connection->release_audio_connection = 1;
1414         }
1415         hfp_emit_simple_event(connection, HFP_SUBEVENT_CALL_TERMINATED);
1416         hfp_ag_run_for_context(connection);
1417         rfcomm_request_can_send_now_event(connection->rfcomm_cid);
1418     }
1419 }
1420 
1421 static void hfp_ag_trigger_terminate_call(void){
1422     int call_indicator_index = get_ag_indicator_index_for_name("call");
1423 
1424     // no ringing during call
1425 
1426     btstack_linked_list_iterator_t it;
1427     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1428     while (btstack_linked_list_iterator_has_next(&it)){
1429         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1430         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1431         if (hfp_connection->call_state == HFP_CALL_IDLE) continue;
1432 
1433         hfp_connection->call_state = HFP_CALL_IDLE;
1434         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1435 
1436         if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1437             hfp_connection->release_audio_connection = 1;
1438         }
1439 
1440         hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_TERMINATED);
1441         hfp_ag_run_for_context(hfp_connection);
1442         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1443     }
1444 }
1445 
1446 static void hfp_ag_set_call_indicator(void){
1447     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("call");
1448     if (!indicator){
1449         log_error("hfp_ag_set_call_state: call indicator is missing");
1450         return;
1451     };
1452     indicator->status = hfp_gsm_call_status();
1453 }
1454 
1455 static hfp_connection_t * hfp_ag_connection_for_call_state(hfp_call_state_t call_state){
1456     btstack_linked_list_iterator_t it;
1457     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1458     while (btstack_linked_list_iterator_has_next(&it)){
1459         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1460         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1461         if (hfp_connection->call_state == call_state) return hfp_connection;
1462     }
1463     return NULL;
1464 }
1465 
1466 static void hfp_ag_send_response_and_hold_state(hfp_response_and_hold_state_t state){
1467     btstack_linked_list_iterator_t it;
1468     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1469     while (btstack_linked_list_iterator_has_next(&it)){
1470         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1471         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1472         hfp_connection->send_response_and_hold_status = state + 1;
1473     }
1474 }
1475 
1476 static int call_setup_state_machine(hfp_connection_t * hfp_connection){
1477     int indicator_index;
1478     switch (hfp_connection->call_state){
1479         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1480             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1481             // we got event: audio hfp_connection established
1482             hfp_connection->call_state = HFP_CALL_INCOMING_RINGING;
1483             break;
1484         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE:
1485             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1486             // we got event: audio hfp_connection established
1487             hfp_connection->call_state = HFP_CALL_ACTIVE;
1488             break;
1489         case HFP_CALL_W2_SEND_CALL_WAITING:
1490             hfp_connection->call_state = HFP_CALL_W4_CHLD;
1491             hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1492             indicator_index = get_ag_indicator_index_for_name("callsetup");
1493             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1494             break;
1495         default:
1496             break;
1497     }
1498     return 0;
1499 }
1500 
1501 // functions extracted from hfp_ag_call_sm below
1502 static void hfp_ag_handle_reject_outgoing_call(void){
1503     hfp_connection_t * hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1504     if (!hfp_connection){
1505         log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1506         return;
1507     }
1508 
1509     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_REJECTED, 0, 0, NULL);
1510     hfp_connection->call_state = HFP_CALL_IDLE;
1511     hfp_connection->send_error = 1;
1512     hfp_ag_run_for_context(hfp_connection);
1513 }
1514 
1515 // hfp_connection is used to identify originating HF
1516 static void hfp_ag_call_sm(hfp_ag_call_event_t event, hfp_connection_t * hfp_connection){
1517 
1518     // allow to intercept call statemachine events
1519     if (hfp_ag_custom_call_sm_handler != NULL){
1520         bool handle_event = (*hfp_ag_custom_call_sm_handler)(event);
1521         if (!handle_event) return;
1522     }
1523 
1524     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1525     int callheld_indicator_index = get_ag_indicator_index_for_name("callheld");
1526     int call_indicator_index = get_ag_indicator_index_for_name("call");
1527 
1528     switch (event){
1529         case HFP_AG_INCOMING_CALL:
1530             switch (hfp_gsm_call_status()){
1531                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1532                     switch (hfp_gsm_callsetup_status()){
1533                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1534                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1535                             hfp_ag_set_callsetup_indicator();
1536                             hfp_ag_trigger_incoming_call_idle();
1537                             log_info("AG rings");
1538                             break;
1539                         default:
1540                             break;
1541                     }
1542                     break;
1543                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1544                     switch (hfp_gsm_callsetup_status()){
1545                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1546                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1547                             hfp_ag_set_callsetup_indicator();
1548                             hfp_ag_trigger_incoming_call_during_active_one();
1549                             log_info("AG call waiting");
1550                             break;
1551                         default:
1552                             break;
1553                     }
1554                     break;
1555                 default:
1556                     break;
1557             }
1558             break;
1559         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG:
1560             switch (hfp_gsm_call_status()){
1561                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1562                     switch (hfp_gsm_callsetup_status()){
1563                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1564                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1565                             hfp_ag_set_call_indicator();
1566                             hfp_ag_set_callsetup_indicator();
1567                             hfp_ag_ag_accept_call();
1568                             log_info("AG answers call, accept call by GSM");
1569                             break;
1570                         default:
1571                             break;
1572                     }
1573                     break;
1574                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1575                     switch (hfp_gsm_callsetup_status()){
1576                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1577                             log_info("AG: current call is placed on hold, incoming call gets active");
1578                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1579                             hfp_ag_set_callsetup_indicator();
1580                             hfp_ag_set_callheld_indicator();
1581                             hfp_ag_transfer_callsetup_state();
1582                             hfp_ag_transfer_callheld_state();
1583                             break;
1584                         default:
1585                             break;
1586                     }
1587                     break;
1588                 default:
1589                     break;
1590             }
1591             break;
1592 
1593         case HFP_AG_HELD_CALL_JOINED_BY_AG:
1594             switch (hfp_gsm_call_status()){
1595                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1596                     switch (hfp_gsm_callheld_status()){
1597                         case HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED:
1598                             log_info("AG: joining held call with active call");
1599                             hfp_gsm_handler(HFP_AG_HELD_CALL_JOINED_BY_AG, 0, 0, NULL);
1600                             hfp_ag_set_callheld_indicator();
1601                             hfp_ag_transfer_callheld_state();
1602                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1603                             break;
1604                         default:
1605                             break;
1606                     }
1607                     break;
1608                 default:
1609                     break;
1610             }
1611             break;
1612 
1613         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF:
1614             switch (hfp_gsm_call_status()){
1615                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1616                     switch (hfp_gsm_callsetup_status()){
1617                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1618                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, 0, 0, NULL);
1619                             hfp_ag_set_callsetup_indicator();
1620                             hfp_ag_set_call_indicator();
1621                             hfp_ag_hf_accept_call(hfp_connection);
1622                             hfp_connection->ok_pending = 1;
1623                             log_info("HF answers call, accept call by GSM");
1624                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1625                             break;
1626                         default:
1627                             break;
1628                     }
1629                     break;
1630                 default:
1631                     break;
1632             }
1633             break;
1634 
1635         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG:
1636             switch (hfp_gsm_call_status()){
1637                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1638                     switch (hfp_gsm_callsetup_status()){
1639                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1640                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, 0, 0, NULL);
1641                             hfp_ag_response_and_hold_active = true;
1642                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1643                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1644                             // as with regular call
1645                             hfp_ag_set_call_indicator();
1646                             hfp_ag_set_callsetup_indicator();
1647                             hfp_ag_ag_accept_call();
1648                             log_info("AG response and hold - hold by AG");
1649                             break;
1650                         default:
1651                             break;
1652                     }
1653                     break;
1654                 default:
1655                     break;
1656             }
1657             break;
1658 
1659         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF:
1660             switch (hfp_gsm_call_status()){
1661                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1662                     switch (hfp_gsm_callsetup_status()){
1663                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1664                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, 0, 0, NULL);
1665                             hfp_ag_response_and_hold_active = true;
1666                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1667                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1668                             // as with regular call
1669                             hfp_ag_set_call_indicator();
1670                             hfp_ag_set_callsetup_indicator();
1671                             hfp_ag_hf_accept_call(hfp_connection);
1672                             log_info("AG response and hold - hold by HF");
1673                             break;
1674                         default:
1675                             break;
1676                     }
1677                     break;
1678                 default:
1679                     break;
1680             }
1681             break;
1682 
1683         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG:
1684         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF:
1685             if (!hfp_ag_response_and_hold_active) break;
1686             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1687             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, 0, 0, NULL);
1688             hfp_ag_response_and_hold_active = false;
1689             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED;
1690             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1691             log_info("Held Call accepted and active");
1692             break;
1693 
1694         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG:
1695         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF:
1696             if (!hfp_ag_response_and_hold_active) break;
1697             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1698             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, 0, 0, NULL);
1699             hfp_ag_response_and_hold_active = false;
1700             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1701             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1702             // from terminate by ag
1703             hfp_ag_set_call_indicator();
1704             hfp_ag_trigger_terminate_call();
1705             break;
1706 
1707         case HFP_AG_TERMINATE_CALL_BY_HF:
1708             switch (hfp_gsm_call_status()){
1709                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1710                     switch (hfp_gsm_callsetup_status()){
1711                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1712                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1713                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1714                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1715                             hfp_ag_set_callsetup_indicator();
1716                             hfp_ag_transfer_callsetup_state();
1717                             hfp_ag_trigger_reject_call();
1718                             log_info("HF Rejected Incoming call, AG terminate call");
1719                             break;
1720                         default:
1721                             break;
1722                     }
1723                     break;
1724                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1725                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1726                     hfp_ag_set_callsetup_indicator();
1727                     hfp_ag_set_call_indicator();
1728                     hfp_ag_trigger_terminate_call();
1729                     log_info("AG terminate call");
1730                     break;
1731                 default:
1732                     break;
1733             }
1734             break;
1735 
1736         case HFP_AG_TERMINATE_CALL_BY_AG:
1737             switch (hfp_gsm_call_status()){
1738                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1739                     switch (hfp_gsm_callsetup_status()){
1740                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1741                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1742                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1743                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1744                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1745                             hfp_ag_set_callsetup_indicator();
1746                             hfp_ag_trigger_reject_call();
1747                             log_info("AG Rejected Incoming call, AG terminate call");
1748                             break;
1749                         default:
1750                             break;
1751                     }
1752                     break;
1753                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1754                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1755                     hfp_ag_set_callsetup_indicator();
1756                     hfp_ag_set_call_indicator();
1757                     hfp_ag_trigger_terminate_call();
1758                     log_info("AG terminate call");
1759                     break;
1760                 default:
1761                     break;
1762             }
1763             break;
1764         case HFP_AG_CALL_DROPPED:
1765             switch (hfp_gsm_call_status()){
1766                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1767                     switch (hfp_gsm_callsetup_status()){
1768                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1769                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1770                             hfp_ag_stop_ringing();
1771                             break;
1772                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1773                             log_info("Outgoing call interrupted\n");
1774                             break;
1775                         default:
1776                             break;
1777                     }
1778                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1779                     hfp_ag_set_callsetup_indicator();
1780                     hfp_ag_transfer_callsetup_state();
1781                     hfp_ag_trigger_terminate_call();
1782                     break;
1783                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1784                     if (hfp_ag_response_and_hold_active) {
1785                         hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1786                         hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1787                         hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1788                     }
1789                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1790                     hfp_ag_set_callsetup_indicator();
1791                     hfp_ag_set_call_indicator();
1792                     hfp_ag_trigger_terminate_call();
1793                     log_info("AG notify call dropped");
1794                     break;
1795                 default:
1796                     break;
1797             }
1798             break;
1799 
1800         case HFP_AG_OUTGOING_CALL_INITIATED_BY_HF:
1801             // directly reject call if number of free slots is exceeded
1802             if (!hfp_gsm_call_possible()){
1803                 hfp_connection->send_error = 1;
1804                 hfp_ag_run_for_context(hfp_connection);
1805                 break;
1806             }
1807 
1808             // note: number not used currently
1809             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, 0, 0, (const char *) &hfp_connection->line_buffer[3]);
1810 
1811             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1812 
1813             hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, (const char *) &hfp_connection->line_buffer[3]);
1814             break;
1815 
1816         case HFP_AG_OUTGOING_CALL_INITIATED_BY_AG:
1817             // directly reject call if number of free slots is exceeded
1818             if (!hfp_gsm_call_possible()) {
1819                 // TODO: no error for user
1820                 break;
1821             }
1822             switch (hfp_gsm_call_status()) {
1823                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1824                     switch (hfp_gsm_callsetup_status()) {
1825                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1826                             // note: number not used currently
1827                             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, 0, 0, "1234567");
1828                             // init call state for all connections
1829                             hfp_ag_trigger_outgoing_call();
1830                             // get first one and accept call
1831                             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1832                             if (hfp_connection) {
1833                                 hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1834                             }
1835                             break;
1836                         default:
1837                             // TODO: no error for user
1838                             break;
1839                     }
1840                     break;
1841                 default:
1842                     // TODO: no error for user
1843                     break;
1844             }
1845             break;
1846         case HFP_AG_OUTGOING_REDIAL_INITIATED:{
1847             // directly reject call if number of free slots is exceeded
1848             if (!hfp_gsm_call_possible()){
1849                 hfp_connection->send_error = 1;
1850                 hfp_ag_run_for_context(hfp_connection);
1851                 break;
1852             }
1853 
1854             hfp_gsm_handler(HFP_AG_OUTGOING_REDIAL_INITIATED, 0, 0, NULL);
1855             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1856 
1857             log_info("Redial last number");
1858             char * last_dialed_number = hfp_gsm_last_dialed_number();
1859 
1860             if (strlen(last_dialed_number) > 0){
1861                 log_info("Last number exists: accept call");
1862                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, last_dialed_number);
1863             } else {
1864                 log_info("log_infoLast number missing: reject call");
1865                 hfp_ag_handle_reject_outgoing_call();
1866             }
1867             break;
1868         }
1869         case HFP_AG_OUTGOING_CALL_REJECTED:
1870             hfp_ag_handle_reject_outgoing_call();
1871             break;
1872 
1873         case HFP_AG_OUTGOING_CALL_ACCEPTED:{
1874             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1875             if (!hfp_connection){
1876                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1877                 break;
1878             }
1879 
1880             hfp_connection->ok_pending = 1;
1881             hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1882             break;
1883         }
1884         case HFP_AG_OUTGOING_CALL_RINGING:
1885             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1886             if (!hfp_connection){
1887                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in dialing state");
1888                 break;
1889             }
1890 
1891             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_RINGING, 0, 0, NULL);
1892             hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1893             hfp_ag_set_callsetup_indicator();
1894             hfp_ag_transfer_callsetup_state();
1895             hfp_ag_hf_start_ringing_outgoing(hfp_connection);
1896             break;
1897 
1898         case HFP_AG_OUTGOING_CALL_ESTABLISHED:{
1899             // get outgoing call
1900             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_RINGING);
1901             if (!hfp_connection){
1902                 hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1903             }
1904             if (!hfp_connection){
1905                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection");
1906                 break;
1907             }
1908 
1909             bool callheld_status_call_on_hold_and_no_active_calls = hfp_gsm_callheld_status() == HFP_CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS;
1910             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ESTABLISHED, 0, 0, NULL);
1911             hfp_connection->call_state = HFP_CALL_ACTIVE;
1912             hfp_ag_set_callsetup_indicator();
1913             hfp_ag_set_call_indicator();
1914             hfp_ag_transfer_call_state();
1915             hfp_ag_transfer_callsetup_state();
1916             if (callheld_status_call_on_hold_and_no_active_calls){
1917                 hfp_ag_set_callheld_indicator();
1918                 hfp_ag_transfer_callheld_state();
1919             }
1920             hfp_ag_hf_stop_ringing(hfp_connection);
1921             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1922             break;
1923         }
1924 
1925         case HFP_AG_CALL_HOLD_USER_BUSY:
1926             hfp_gsm_handler(HFP_AG_CALL_HOLD_USER_BUSY, 0, 0, NULL);
1927             hfp_ag_set_callsetup_indicator();
1928             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1929             hfp_connection->call_state = HFP_CALL_ACTIVE;
1930             log_info("AG: Call Waiting, User Busy");
1931             break;
1932 
1933         case HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1934             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1935             int call_held = hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD;
1936 
1937             // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
1938             if (call_held || call_setup_in_progress){
1939                 hfp_gsm_handler(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index,
1940                                 0, NULL);
1941 
1942             }
1943 
1944             if (call_setup_in_progress){
1945                 log_info("AG: Call Dropped, Accept new call");
1946                 hfp_ag_set_callsetup_indicator();
1947                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1948             } else {
1949                 log_info("AG: Call Dropped, Resume held call");
1950             }
1951             if (call_held){
1952                 hfp_ag_set_callheld_indicator();
1953                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1954             }
1955 
1956             hfp_connection->call_state = HFP_CALL_ACTIVE;
1957             break;
1958         }
1959 
1960         case HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1961             // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
1962             // only update if callsetup changed
1963             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1964             hfp_gsm_handler(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index, 0,
1965                             NULL);
1966 
1967             if (call_setup_in_progress){
1968                 log_info("AG: Call on Hold, Accept new call");
1969                 hfp_ag_set_callsetup_indicator();
1970                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1971             } else {
1972                 log_info("AG: Swap calls");
1973             }
1974 
1975             hfp_ag_set_callheld_indicator();
1976             // hfp_ag_set_callheld_state(HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED);
1977             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1978             hfp_connection->call_state = HFP_CALL_ACTIVE;
1979             break;
1980         }
1981 
1982         case HFP_AG_CALL_HOLD_ADD_HELD_CALL:
1983             // Adds a held call to the conversation.
1984             if (hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD){
1985                 log_info("AG: Join 3-way-call");
1986                 hfp_gsm_handler(HFP_AG_CALL_HOLD_ADD_HELD_CALL, 0, 0, NULL);
1987                 hfp_ag_set_callheld_indicator();
1988                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1989                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1990             }
1991             hfp_connection->call_state = HFP_CALL_ACTIVE;
1992             break;
1993         case HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS:
1994             // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer)
1995             hfp_gsm_handler(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, 0, 0, NULL);
1996             log_info("AG: Transfer call -> Connect two calls and disconnect");
1997             hfp_ag_set_call_indicator();
1998             hfp_ag_set_callheld_indicator();
1999             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
2000             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
2001             hfp_connection->call_state = HFP_CALL_IDLE;
2002             break;
2003 
2004         default:
2005             break;
2006     }
2007 
2008 
2009 }
2010 
2011 
2012 static void hfp_ag_send_call_status(hfp_connection_t * hfp_connection, int call_index){
2013     hfp_gsm_call_t * active_call = hfp_gsm_call(call_index);
2014     if (!active_call) return;
2015 
2016     int idx = active_call->index;
2017     hfp_enhanced_call_dir_t dir = active_call->direction;
2018     hfp_enhanced_call_status_t status = active_call->enhanced_status;
2019     hfp_enhanced_call_mode_t mode = active_call->mode;
2020     hfp_enhanced_call_mpty_t mpty = active_call->mpty;
2021     uint8_t type = active_call->clip_type;
2022     char * number = active_call->clip_number;
2023 
2024     char buffer[100];
2025     // TODO: check length of a buffer, to fit the MTU
2026     int offset = snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d,%d,%d,%d", HFP_LIST_CURRENT_CALLS, idx, dir, status, mode, mpty);
2027     if (number){
2028         offset += snprintf(buffer+offset, sizeof(buffer)-offset-3, ", \"%s\",%u", number, type);
2029     }
2030     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n");
2031     log_info("hfp_ag_send_current_call_status 000 index %d, dir %d, status %d, mode %d, mpty %d, type %d, number %s", idx, dir, status,
2032        mode, mpty, type, number);
2033     send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
2034 }
2035 
2036 // sends pending command, returns if command was sent
2037 static int hfp_ag_send_commands(hfp_connection_t *hfp_connection){
2038     if (hfp_connection->send_status_of_current_calls){
2039         hfp_connection->ok_pending = 0;
2040         if (hfp_connection->next_call_index < hfp_gsm_get_number_of_calls()){
2041             hfp_connection->next_call_index++;
2042             hfp_ag_send_call_status(hfp_connection, hfp_connection->next_call_index);
2043             return 1;
2044         } else {
2045             // TODO: this code should be removed. check a) before setting send_status_of_current_calls, or b) right before hfp_ag_send_call_status above
2046             hfp_connection->next_call_index = 0;
2047             hfp_connection->ok_pending = 1;
2048             hfp_connection->send_status_of_current_calls = 0;
2049         }
2050     }
2051 
2052     if (hfp_connection->ag_notify_incoming_call_waiting){
2053         hfp_connection->ag_notify_incoming_call_waiting = 0;
2054         hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
2055         return 1;
2056     }
2057 
2058     if (hfp_connection->send_error){
2059         hfp_connection->send_error = 0;
2060         hfp_connection->command = HFP_CMD_NONE;
2061         hfp_ag_send_error(hfp_connection->rfcomm_cid);
2062         return 1;
2063     }
2064 
2065     // note: before update AG indicators and ok_pending
2066     if (hfp_connection->send_response_and_hold_status){
2067         int status = hfp_connection->send_response_and_hold_status - 1;
2068         hfp_connection->send_response_and_hold_status = 0;
2069         hfp_ag_send_set_response_and_hold(hfp_connection->rfcomm_cid, status);
2070         return 1;
2071     }
2072 
2073     if (hfp_connection->ok_pending){
2074         hfp_connection->ok_pending = 0;
2075         hfp_connection->command = HFP_CMD_NONE;
2076         hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2077         return 1;
2078     }
2079 
2080     // update AG indicators only if enabled by AT+CMER=3,0,0,1
2081     if ((hfp_connection->enable_status_update_for_ag_indicators == 1) && (hfp_connection->ag_indicators_status_update_bitmap != 0)){
2082         uint16_t i;
2083         for (i=0;i<hfp_connection->ag_indicators_nr;i++){
2084             if (get_bit(hfp_connection->ag_indicators_status_update_bitmap, i)){
2085                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, i, 0);
2086                 hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[i]);
2087                 return 1;
2088             }
2089         }
2090     }
2091 
2092     if (hfp_connection->ag_send_no_carrier){
2093         hfp_connection->ag_send_no_carrier = false;
2094         hfp_ag_send_no_carrier(hfp_connection->rfcomm_cid);
2095         return 1;
2096     }
2097 
2098     if (hfp_connection->send_phone_number_for_voice_tag){
2099         hfp_connection->send_phone_number_for_voice_tag = 0;
2100         hfp_connection->command = HFP_CMD_NONE;
2101         hfp_connection->ok_pending = 1;
2102         hfp_ag_send_phone_number_for_voice_tag_cmd(hfp_connection->rfcomm_cid);
2103         return 1;
2104     }
2105 
2106     if (hfp_connection->send_subscriber_number){
2107         if (hfp_connection->next_subscriber_number_to_send < hfp_ag_subscriber_numbers_count){
2108             hfp_phone_number_t phone = hfp_ag_subscriber_numbers[hfp_connection->next_subscriber_number_to_send++];
2109             hfp_send_subscriber_number_cmd(hfp_connection->rfcomm_cid, phone.type, phone.number);
2110         } else {
2111             hfp_connection->send_subscriber_number = 0;
2112             hfp_connection->next_subscriber_number_to_send = 0;
2113             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2114         }
2115         hfp_connection->command = HFP_CMD_NONE;
2116         return 1;
2117     }
2118 
2119     if (hfp_connection->send_microphone_gain){
2120         hfp_connection->send_microphone_gain = 0;
2121         hfp_connection->command = HFP_CMD_NONE;
2122         hfp_ag_send_set_microphone_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->microphone_gain);
2123         return 1;
2124     }
2125 
2126     if (hfp_connection->send_speaker_gain){
2127         hfp_connection->send_speaker_gain = 0;
2128         hfp_connection->command = HFP_CMD_NONE;
2129         hfp_ag_send_set_speaker_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->speaker_gain);
2130         return 1;
2131     }
2132 
2133     if (hfp_connection->send_ag_status_indicators){
2134         hfp_connection->send_ag_status_indicators = 0;
2135         hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
2136         return 1;
2137     }
2138 
2139     return 0;
2140 }
2141 
2142 // sends pending command, returns if command was sent
2143 static int hfp_ag_run_ring_and_clip(hfp_connection_t *hfp_connection){
2144     // delay RING/CLIP until audio connection has been established for incoming calls
2145     // hfp_ag_hf_trigger_ring_and_clip is called in call_setup_state_machine
2146     if (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING){
2147         if (hfp_connection->ag_ring){
2148             hfp_connection->ag_ring = 0;
2149             hfp_connection->command = HFP_CMD_NONE;
2150             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_RING);
2151             hfp_ag_send_ring(hfp_connection->rfcomm_cid);
2152             return 1;
2153         }
2154 
2155         if (hfp_connection->ag_send_clip){
2156             hfp_connection->ag_send_clip = 0;
2157             hfp_connection->command = HFP_CMD_NONE;
2158             hfp_ag_send_clip(hfp_connection->rfcomm_cid);
2159             return 1;
2160         }
2161     }
2162     return 0;
2163 }
2164 
2165 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection){
2166 
2167 	btstack_assert(hfp_connection != NULL);
2168 	btstack_assert(hfp_connection->local_role == HFP_ROLE_AG);
2169 
2170 	// during SDP query, RFCOMM CID is not set
2171 	if (hfp_connection->rfcomm_cid == 0) return;
2172 
2173     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED && hfp_connection->emit_vra_enabled_after_audio_established){
2174         hfp_connection->emit_vra_enabled_after_audio_established = false;
2175         hfp_emit_voice_recognition_enabled(hfp_connection, ERROR_CODE_SUCCESS);
2176     }
2177 
2178     if ((hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) && hfp_connection->release_audio_connection){
2179         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
2180         hfp_connection->release_audio_connection = 0;
2181         gap_disconnect(hfp_connection->sco_handle);
2182         return;
2183     }
2184 
2185     // configure NBS/WBS if needed using vendor-specific HCI commands
2186     if (hci_can_send_command_packet_now()) {
2187 #ifdef ENABLE_CC256X_ASSISTED_HFP
2188         // WBS Disassociate
2189         if (hfp_connection->cc256x_send_wbs_disassociate){
2190             hfp_connection->cc256x_send_wbs_disassociate = false;
2191             hci_send_cmd(&hci_ti_wbs_disassociate);
2192             return;
2193         }
2194         // Write Codec Config
2195         if (hfp_connection->cc256x_send_write_codec_config){
2196             hfp_connection->cc256x_send_write_codec_config = false;
2197             hfp_cc256x_write_codec_config(hfp_connection);
2198             return;
2199         }
2200         // WBS Associate
2201         if (hfp_connection->cc256x_send_wbs_associate){
2202             hfp_connection->cc256x_send_wbs_associate = false;
2203             hci_send_cmd(&hci_ti_wbs_associate, hfp_connection->acl_handle);
2204             return;
2205         }
2206 #endif
2207 #ifdef ENABLE_BCM_PCM_WBS
2208         // Enable WBS
2209         if (hfp_connection->bcm_send_enable_wbs){
2210             hfp_connection->bcm_send_enable_wbs = false;
2211             hci_send_cmd(&hci_bcm_enable_wbs, 1, 2);
2212             return;
2213         }
2214         // Write I2S/PCM params
2215         if (hfp_connection->bcm_send_write_i2spcm_interface_param){
2216             hfp_connection->bcm_send_write_i2spcm_interface_param = false;
2217             hfp_bcm_write_i2spcm_interface_param(hfp_connection);
2218             return;
2219         }
2220         // Disable WBS
2221         if (hfp_connection->bcm_send_disable_wbs){
2222             hfp_connection->bcm_send_disable_wbs = false;
2223             hci_send_cmd(&hci_bcm_enable_wbs, 0, 2);
2224             return;
2225         }
2226 #endif
2227 #ifdef ENABLE_RTK_PCM_WBS
2228         // Configure CVSD vs. mSBC
2229         if (hfp_connection->rtk_send_sco_config){
2230             hfp_connection->rtk_send_sco_config = false;
2231             if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
2232                 log_info("RTK SCO: 16k + mSBC");
2233                 hci_send_cmd(&hci_rtk_configure_sco_routing, 0x81, 0x90, 0x00, 0x00, 0x1a, 0x0c, 0x00, 0x00, 0x41);
2234             } else {
2235                 log_info("RTK SCO: 16k + CVSD");
2236                 hci_send_cmd(&hci_rtk_configure_sco_routing, 0x81, 0x90, 0x00, 0x00, 0x1a, 0x0c, 0x0c, 0x00, 0x01);
2237             }
2238             return;
2239         }
2240 #endif
2241     }
2242 
2243 #if defined (ENABLE_CC256X_ASSISTED_HFP) || defined (ENABLE_BCM_PCM_WBS)
2244     if (hfp_connection->state == HFP_W4_WBS_SHUTDOWN){
2245         hfp_finalize_connection_context(hfp_connection);
2246         return;
2247     }
2248 #endif
2249 
2250     if (!rfcomm_can_send_packet_now(hfp_connection->rfcomm_cid)) {
2251         log_info("hfp_ag_run_for_context: request can send for 0x%02x", hfp_connection->rfcomm_cid);
2252         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2253         return;
2254     }
2255 
2256     int cmd_sent = hfp_ag_send_commands(hfp_connection);
2257 
2258     if (!cmd_sent){
2259         cmd_sent = hfp_ag_run_for_context_service_level_connection(hfp_connection);
2260     }
2261 
2262     if (!cmd_sent){
2263         cmd_sent = hfp_ag_run_for_context_service_level_connection_queries(hfp_connection);
2264     }
2265 
2266     if (!cmd_sent){
2267         cmd_sent = call_setup_state_machine(hfp_connection);
2268     }
2269 
2270     if (!cmd_sent){
2271         cmd_sent = hfp_ag_run_for_audio_connection(hfp_connection);
2272     }
2273 
2274     if (!cmd_sent){
2275         cmd_sent = hfp_ag_run_ring_and_clip(hfp_connection);
2276     }
2277 
2278     if (!cmd_sent){
2279         cmd_sent = hfp_ag_voice_recognition_state_machine(hfp_connection);
2280     }
2281 
2282     // disconnect
2283     if (!cmd_sent && (hfp_connection->command == HFP_CMD_NONE) && (hfp_connection->state == HFP_W2_DISCONNECT_RFCOMM)){
2284         hfp_connection->state = HFP_W4_RFCOMM_DISCONNECTED;
2285         rfcomm_disconnect(hfp_connection->rfcomm_cid);
2286     }
2287 
2288     if (cmd_sent){
2289         hfp_connection->command = HFP_CMD_NONE;
2290         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2291     }
2292 }
2293 
2294 static int hfp_parser_is_end_of_line(uint8_t byte){
2295     return (byte == '\n') || (byte == '\r');
2296 }
2297 
2298 static void hfp_ag_handle_rfcomm_data(hfp_connection_t * hfp_connection, uint8_t *packet, uint16_t size){
2299     // assertion: size >= 1 as rfcomm.c does not deliver empty packets
2300     if (size < 1) return;
2301     uint8_t status = ERROR_CODE_SUCCESS;
2302 
2303     hfp_log_rfcomm_message("HFP_AG_RX", packet, size);
2304 #ifdef ENABLE_HFP_AT_MESSAGES
2305     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_RECEIVED, (char *) packet);
2306 #endif
2307 
2308     // process messages byte-wise
2309     int pos;
2310     for (pos = 0; pos < size ; pos++){
2311         hfp_parse(hfp_connection, packet[pos], 0);
2312 
2313         // parse until end of line
2314         if (!hfp_parser_is_end_of_line(packet[pos])) continue;
2315 
2316         hfp_generic_status_indicator_t * indicator;
2317         switch(hfp_connection->command){
2318             case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
2319                 hfp_connection->command = HFP_CMD_NONE;
2320                 hfp_connection->ag_vra_requested_by_hf = true;
2321                 break;
2322             case HFP_CMD_RESPONSE_AND_HOLD_QUERY:
2323                 hfp_connection->command = HFP_CMD_NONE;
2324                 if (hfp_ag_response_and_hold_active){
2325                     hfp_connection->send_response_and_hold_status = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD + 1;
2326                 }
2327                 hfp_connection->ok_pending = 1;
2328                 break;
2329             case HFP_CMD_RESPONSE_AND_HOLD_COMMAND:
2330                 hfp_connection->command = HFP_CMD_NONE;
2331                 switch(hfp_connection->ag_response_and_hold_action){
2332                     case HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD:
2333                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, hfp_connection);
2334                         break;
2335                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED:
2336                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF, hfp_connection);
2337                         break;
2338                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED:
2339                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF, hfp_connection);
2340                         break;
2341                     default:
2342                         break;
2343                 }
2344                 hfp_connection->ok_pending = 1;
2345                 break;
2346             case HFP_CMD_HF_INDICATOR_STATUS:
2347                 hfp_connection->command = HFP_CMD_NONE;
2348 
2349                 if (hfp_connection->parser_indicator_index < hfp_ag_generic_status_indicators_nr){
2350                     indicator = &hfp_ag_generic_status_indicators[hfp_connection->parser_indicator_index];
2351                     switch (indicator->uuid){
2352                         case HFP_HF_INDICATOR_UUID_ENHANCED_SAFETY:
2353                             if (hfp_connection->parser_indicator_value > 1) {
2354                                 hfp_connection->send_error = 1;
2355                                 break;
2356                             }
2357                             hfp_connection->ok_pending = 1;
2358                             hfp_ag_emit_hf_indicator_value(hfp_connection, indicator->uuid, hfp_connection->parser_indicator_value);
2359                             break;
2360                         case HFP_HF_INDICATOR_UUID_BATTERY_LEVEL:
2361                             if (hfp_connection->parser_indicator_value > 100){
2362                                 hfp_connection->send_error = 1;
2363                                 break;
2364                             }
2365                             hfp_connection->ok_pending = 1;
2366                             hfp_ag_emit_hf_indicator_value(hfp_connection, indicator->uuid, hfp_connection->parser_indicator_value);
2367                             break;
2368                         default:
2369                             hfp_connection->send_error = 1;
2370                             break;
2371                     }
2372                 } else {
2373                     hfp_connection->send_error = 1;
2374                 }
2375                 break;
2376             case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
2377                 // expected by SLC state machine
2378                 if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) break;
2379                 hfp_connection->send_ag_indicators_segment = 0;
2380                 hfp_connection->send_ag_status_indicators = 1;
2381                 break;
2382             case HFP_CMD_LIST_CURRENT_CALLS:
2383                 hfp_connection->command = HFP_CMD_NONE;
2384                 hfp_connection->next_call_index = 0;
2385                 hfp_connection->send_status_of_current_calls = 1;
2386                 break;
2387             case HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION:
2388                 hfp_connection->command = HFP_CMD_NONE;
2389                 if (hfp_ag_subscriber_numbers_count == 0){
2390                     hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2391                     break;
2392                 }
2393                 hfp_connection->next_subscriber_number_to_send = 0;
2394                 hfp_connection->send_subscriber_number = 1;
2395                 break;
2396             case HFP_CMD_TRANSMIT_DTMF_CODES:
2397             {
2398                 hfp_connection->command = HFP_CMD_NONE;
2399                 char buffer[2];
2400                 buffer[0] = (char) hfp_connection->ag_dtmf_code;
2401                 buffer[1] = 0;
2402                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_TRANSMIT_DTMF_CODES, buffer);
2403                 break;
2404             }
2405             case HFP_CMD_HF_REQUEST_PHONE_NUMBER:
2406                 hfp_connection->command = HFP_CMD_NONE;
2407                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_ATTACH_NUMBER_TO_VOICE_TAG);
2408                 break;
2409             case HFP_CMD_TURN_OFF_EC_AND_NR:
2410                 hfp_connection->command = HFP_CMD_NONE;
2411 
2412                 if (get_bit(hfp_ag_supported_features, HFP_AGSF_EC_NR_FUNCTION)){
2413                     hfp_connection->ok_pending = 1;
2414                     hfp_ag_supported_features = store_bit(hfp_ag_supported_features, HFP_AGSF_EC_NR_FUNCTION, hfp_connection->ag_echo_and_noise_reduction);
2415                     status = ERROR_CODE_SUCCESS;
2416                 } else {
2417                     hfp_connection->send_error = 1;
2418                     status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2419                 }
2420                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_ECHO_CANCELING_AND_NOISE_REDUCTION_DEACTIVATE, status);
2421                 break;
2422             case HFP_CMD_CALL_ANSWERED:
2423                 hfp_connection->command = HFP_CMD_NONE;
2424                 log_info("HFP: ATA");
2425                 hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, hfp_connection);
2426                 break;
2427             case HFP_CMD_HANG_UP_CALL:
2428                 hfp_connection->command = HFP_CMD_NONE;
2429                 hfp_connection->ok_pending = 1;
2430                 hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_HF, hfp_connection);
2431                 break;
2432             case HFP_CMD_CALL_HOLD: {
2433                 hfp_connection->command = HFP_CMD_NONE;
2434                 hfp_connection->ok_pending = 1;
2435 
2436                 switch (hfp_connection->ag_call_hold_action){
2437                     case 0:
2438                         // Releases all held calls or sets User Determined User Busy (UDUB) for a waiting call.
2439                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_USER_BUSY, hfp_connection);
2440                         break;
2441                     case 1:
2442                         // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
2443                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2444                         // waiting call (i.e., not to the held call) in conflicting situation.
2445                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2446                         break;
2447                     case 2:
2448                         // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
2449                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2450                         // waiting call (i.e., not to the held call) in conflicting situation.
2451                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2452                         break;
2453                     case 3:
2454                         // Adds a held call to the conversation.
2455                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_ADD_HELD_CALL, hfp_connection);
2456                         break;
2457                     case 4:
2458                         // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer).
2459                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, hfp_connection);
2460                         break;
2461                     default:
2462                         break;
2463                 }
2464 				hfp_connection->call_index = 0;
2465                 break;
2466             }
2467             case HFP_CMD_CALL_PHONE_NUMBER:
2468                 hfp_connection->command = HFP_CMD_NONE;
2469                 hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, hfp_connection);
2470                 break;
2471             case HFP_CMD_REDIAL_LAST_NUMBER:
2472                 hfp_connection->command = HFP_CMD_NONE;
2473                 hfp_ag_call_sm(HFP_AG_OUTGOING_REDIAL_INITIATED, hfp_connection);
2474                 break;
2475             case HFP_CMD_ENABLE_CLIP:
2476                 hfp_connection->command = HFP_CMD_NONE;
2477                 log_info("hfp: clip set, now: %u", hfp_connection->clip_enabled);
2478                 hfp_connection->ok_pending = 1;
2479                 break;
2480             case HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION:
2481                 hfp_connection->command = HFP_CMD_NONE;
2482                 log_info("hfp: call waiting notification set, now: %u", hfp_connection->call_waiting_notification_enabled);
2483                 hfp_connection->ok_pending = 1;
2484                 break;
2485             case HFP_CMD_SET_SPEAKER_GAIN:
2486                 hfp_connection->command = HFP_CMD_NONE;
2487                 hfp_connection->ok_pending = 1;
2488                 log_info("HF speaker gain = %u", hfp_connection->speaker_gain);
2489                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_SPEAKER_VOLUME, hfp_connection->speaker_gain);
2490                 break;
2491             case HFP_CMD_SET_MICROPHONE_GAIN:
2492                 hfp_connection->command = HFP_CMD_NONE;
2493                 hfp_connection->ok_pending = 1;
2494                 log_info("HF microphone gain = %u", hfp_connection->microphone_gain);
2495                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_MICROPHONE_VOLUME, hfp_connection->microphone_gain);
2496                 break;
2497             case HFP_CMD_UNKNOWN:
2498                 hfp_connection->command = HFP_CMD_NONE;
2499                 hfp_connection->send_error = 1;
2500                 break;
2501             default:
2502                 break;
2503         }
2504     }
2505 }
2506 
2507 static void hfp_ag_run(void){
2508     btstack_linked_list_iterator_t it;
2509     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2510     while (btstack_linked_list_iterator_has_next(&it)){
2511         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2512         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2513         hfp_ag_run_for_context(hfp_connection);
2514     }
2515 }
2516 
2517 static void hfp_ag_rfcomm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2518     hfp_connection_t * hfp_connection = NULL;
2519     switch (packet_type){
2520         case RFCOMM_DATA_PACKET:
2521             hfp_connection = get_hfp_connection_context_for_rfcomm_cid(channel);
2522             btstack_assert(hfp_connection != NULL);
2523 
2524             hfp_ag_handle_rfcomm_data(hfp_connection, packet, size);
2525             hfp_ag_run_for_context(hfp_connection);
2526             return;
2527         case HCI_EVENT_PACKET:
2528             if (packet[0] == RFCOMM_EVENT_CAN_SEND_NOW){
2529                 uint16_t rfcomm_cid = rfcomm_event_can_send_now_get_rfcomm_cid(packet);
2530                 hfp_connection = get_hfp_connection_context_for_rfcomm_cid(rfcomm_cid);
2531                 btstack_assert(hfp_connection != NULL);
2532 
2533                 hfp_ag_run_for_context(hfp_connection);
2534                 return;
2535             }
2536             hfp_handle_rfcomm_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2537             break;
2538         default:
2539             break;
2540     }
2541 
2542     hfp_ag_run();
2543 }
2544 
2545 static void hfp_ag_hci_event_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2546     hfp_handle_hci_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2547     hfp_ag_run();
2548 }
2549 
2550 void hfp_ag_init_codecs(int codecs_nr, const uint8_t * codecs){
2551     if (codecs_nr > HFP_MAX_NUM_CODECS){
2552         log_error("hfp_init: codecs_nr (%d) > HFP_MAX_NUM_CODECS (%d)", codecs_nr, HFP_MAX_NUM_CODECS);
2553         return;
2554     }
2555     int i;
2556     hfp_ag_codecs_nr = codecs_nr;
2557     for (i=0; i < codecs_nr; i++){
2558         hfp_ag_codecs[i] = codecs[i];
2559     }
2560 }
2561 
2562 void hfp_ag_init_supported_features(uint32_t supported_features){
2563     hfp_ag_supported_features = supported_features;
2564 }
2565 
2566 void hfp_ag_init_ag_indicators(int ag_indicators_nr, const hfp_ag_indicator_t * ag_indicators){
2567     hfp_ag_indicators_nr = ag_indicators_nr;
2568     (void)memcpy(hfp_ag_indicators, ag_indicators,
2569                  ag_indicators_nr * sizeof(hfp_ag_indicator_t));
2570 }
2571 
2572 void hfp_ag_init_hf_indicators(int hf_indicators_nr, const hfp_generic_status_indicator_t * hf_indicators){
2573     if (hf_indicators_nr > HFP_MAX_NUM_INDICATORS) return;
2574     hfp_ag_generic_status_indicators_nr = hf_indicators_nr;
2575     (void)memcpy(hfp_ag_generic_status_indicators, hf_indicators,
2576                  hf_indicators_nr * sizeof(hfp_generic_status_indicator_t));
2577 }
2578 
2579 void hfp_ag_init_call_hold_services(int call_hold_services_nr, const char * call_hold_services[]){
2580     hfp_ag_call_hold_services_nr = call_hold_services_nr;
2581     (void)memcpy(hfp_ag_call_hold_services, call_hold_services,
2582                  call_hold_services_nr * sizeof(char *));
2583 }
2584 
2585 
2586 void hfp_ag_init(uint8_t rfcomm_channel_nr){
2587 
2588     hfp_init();
2589     hfp_ag_call_hold_services_nr = 0;
2590     hfp_ag_response_and_hold_active = false;
2591     hfp_ag_indicators_nr = 0;
2592     hfp_ag_codecs_nr = 0;
2593     hfp_ag_supported_features = HFP_DEFAULT_AG_SUPPORTED_FEATURES;
2594     hfp_ag_subscriber_numbers = NULL;
2595     hfp_ag_subscriber_numbers_count = 0;
2596 
2597     hfp_ag_hci_event_callback_registration.callback = &hfp_ag_hci_event_packet_handler;
2598     hci_add_event_handler(&hfp_ag_hci_event_callback_registration);
2599 
2600     rfcomm_register_service(&hfp_ag_rfcomm_packet_handler, rfcomm_channel_nr, 0xffff);
2601 
2602     // used to set packet handler for outgoing rfcomm connections - could be handled by emitting an event to us
2603     hfp_set_ag_rfcomm_packet_handler(&hfp_ag_rfcomm_packet_handler);
2604 
2605     hfp_gsm_init();
2606 }
2607 
2608 void hfp_ag_deinit(void){
2609     hfp_deinit();
2610     hfp_gsm_deinit();
2611 
2612     hfp_ag_callback = NULL;
2613     hfp_ag_supported_features = 0;
2614     hfp_ag_codecs_nr = 0;
2615     hfp_ag_indicators_nr = 0;
2616     hfp_ag_call_hold_services_nr = 0;
2617     (void) memset(&hfp_ag_call_hold_services, 0, sizeof(hfp_ag_call_hold_services));
2618     hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
2619     (void) memset(&hfp_ag_response_and_hold_state, 0, sizeof(hfp_response_and_hold_state_t));
2620     hfp_ag_subscriber_numbers = NULL;
2621     (void) memset(&hfp_ag_hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
2622     hfp_ag_custom_call_sm_handler = NULL;
2623 }
2624 
2625 uint8_t hfp_ag_establish_service_level_connection(bd_addr_t bd_addr){
2626     return hfp_establish_service_level_connection(bd_addr, BLUETOOTH_SERVICE_CLASS_HANDSFREE, HFP_ROLE_AG);
2627 }
2628 
2629 uint8_t hfp_ag_release_service_level_connection(hci_con_handle_t acl_handle){
2630     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2631     if (!hfp_connection){
2632         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2633     }
2634 
2635     hfp_trigger_release_service_level_connection(hfp_connection);
2636     hfp_ag_run_for_context(hfp_connection);
2637     return ERROR_CODE_SUCCESS;
2638 }
2639 
2640 uint8_t hfp_ag_report_extended_audio_gateway_error_result_code(hci_con_handle_t acl_handle, hfp_cme_error_t error){
2641     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2642     if (!hfp_connection){
2643         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2644     }
2645 
2646     hfp_connection->extended_audio_gateway_error = 0;
2647     if (!hfp_connection->enable_extended_audio_gateway_error_report){
2648         return ERROR_CODE_COMMAND_DISALLOWED;
2649     }
2650 
2651     hfp_connection->extended_audio_gateway_error = error;
2652     hfp_ag_run_for_context(hfp_connection);
2653     return ERROR_CODE_SUCCESS;
2654 }
2655 
2656 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection){
2657     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
2658         return ERROR_CODE_COMMAND_DISALLOWED;
2659     }
2660     if (hfp_connection->state >= HFP_W2_DISCONNECT_SCO){
2661         return ERROR_CODE_COMMAND_DISALLOWED;
2662     }
2663 
2664     hfp_connection->establish_audio_connection = 1;
2665     if (!has_codec_negotiation_feature(hfp_connection)){
2666         log_info("hfp_ag_establish_audio_connection - no codec negotiation feature, using CVSD");
2667         hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
2668         hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
2669         // now, pick link settings
2670         hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
2671 #ifdef ENABLE_CC256X_ASSISTED_HFP
2672         hfp_cc256x_prepare_for_sco(hfp_connection);
2673 #endif
2674         return ERROR_CODE_SUCCESS;
2675     }
2676 
2677     uint8_t i;
2678     bool codec_was_in_use = false;
2679     bool better_codec_can_be_used = false;
2680 
2681     for (i = 0; i<hfp_connection->remote_codecs_nr; i++){
2682         if (hfp_connection->negotiated_codec == hfp_connection->remote_codecs[i]){
2683             codec_was_in_use = true;
2684         } else if (hfp_connection->negotiated_codec < hfp_connection->remote_codecs[i]){
2685             better_codec_can_be_used = true;
2686         }
2687     }
2688 
2689     if (!codec_was_in_use || better_codec_can_be_used){
2690         hfp_connection->ag_send_common_codec = true;
2691         hfp_connection->codecs_state = HFP_CODECS_IDLE;
2692     }
2693     return ERROR_CODE_SUCCESS;
2694 }
2695 
2696 uint8_t hfp_ag_establish_audio_connection(hci_con_handle_t acl_handle){
2697     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2698     if (!hfp_connection){
2699         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2700     }
2701     uint8_t status = hfp_ag_setup_audio_connection(hfp_connection);
2702     if (status != ERROR_CODE_SUCCESS){
2703         return status;
2704     }
2705     hfp_ag_run_for_context(hfp_connection);
2706     return ERROR_CODE_SUCCESS;
2707 }
2708 
2709 uint8_t hfp_ag_release_audio_connection(hci_con_handle_t acl_handle){
2710     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2711     if (!hfp_connection){
2712         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2713     }
2714 
2715     if (hfp_connection->vra_state == HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
2716         return ERROR_CODE_COMMAND_DISALLOWED;
2717     }
2718 
2719     uint8_t status = hfp_trigger_release_audio_connection(hfp_connection);
2720     if (status == ERROR_CODE_SUCCESS){
2721         hfp_ag_run_for_context(hfp_connection);
2722     }
2723     return status;
2724 }
2725 
2726 /**
2727  * @brief Enable in-band ring tone
2728  */
2729 void hfp_ag_set_use_in_band_ring_tone(int use_in_band_ring_tone){
2730     if (get_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE) == use_in_band_ring_tone){
2731         return;
2732     }
2733 
2734     hfp_ag_supported_features = store_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE, use_in_band_ring_tone);
2735 
2736     btstack_linked_list_iterator_t it;
2737     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2738     while (btstack_linked_list_iterator_has_next(&it)){
2739         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2740         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2741         hfp_connection->ag_send_in_band_ring_tone_setting = true;
2742         hfp_ag_run_for_context(hfp_connection);
2743     }
2744 }
2745 
2746 /**
2747  * @brief Called from GSM
2748  */
2749 void hfp_ag_incoming_call(void){
2750     hfp_ag_call_sm(HFP_AG_INCOMING_CALL, NULL);
2751 }
2752 
2753 void hfp_ag_outgoing_call_initiated(void) {
2754     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, NULL);
2755 }
2756 
2757 /**
2758  * @brief number is stored.
2759  */
2760 void hfp_ag_set_clip(uint8_t type, const char * number){
2761     hfp_gsm_handler(HFP_AG_SET_CLIP, 0, type, number);
2762 }
2763 
2764 void hfp_ag_call_dropped(void){
2765     hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2766 }
2767 
2768 // call from AG UI
2769 void hfp_ag_answer_incoming_call(void){
2770     hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, NULL);
2771 }
2772 
2773 void hfp_ag_join_held_call(void){
2774     hfp_ag_call_sm(HFP_AG_HELD_CALL_JOINED_BY_AG, NULL);
2775 }
2776 
2777 void hfp_ag_terminate_call(void){
2778     hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_AG, NULL);
2779 }
2780 
2781 void hfp_ag_outgoing_call_ringing(void){
2782     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_RINGING, NULL);
2783 }
2784 
2785 void hfp_ag_outgoing_call_established(void){
2786     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ESTABLISHED, NULL);
2787 }
2788 
2789 void hfp_ag_outgoing_call_rejected(void){
2790     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_REJECTED, NULL);
2791 }
2792 
2793 void hfp_ag_outgoing_call_accepted(void){
2794     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ACCEPTED, NULL);
2795 }
2796 
2797 void hfp_ag_hold_incoming_call(void){
2798     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, NULL);
2799 }
2800 
2801 void hfp_ag_accept_held_incoming_call(void) {
2802     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, NULL);
2803 }
2804 
2805 void hfp_ag_reject_held_incoming_call(void){
2806     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, NULL);
2807 }
2808 
2809 static void hfp_ag_set_ag_indicator(const char * name, int value){
2810     int indicator_index = get_ag_indicator_index_for_name(name);
2811     if (indicator_index < 0) return;
2812     hfp_ag_indicators[indicator_index].status = value;
2813 
2814     btstack_linked_list_iterator_t it;
2815     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2816     while (btstack_linked_list_iterator_has_next(&it)){
2817         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2818         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2819         if (!hfp_connection->ag_indicators[indicator_index].enabled) {
2820             log_info("Requested AG indicator '%s' update to %u, but it is not enabled", hfp_ag_indicators[indicator_index].name, value);
2821             continue;
2822         }
2823         log_info("AG indicator '%s' changed to %u, request transfer status", hfp_ag_indicators[indicator_index].name, value);
2824         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
2825         hfp_ag_run_for_context(hfp_connection);
2826     }
2827 }
2828 
2829 uint8_t hfp_ag_set_registration_status(int registration_status){
2830     if ((registration_status < 0) || (registration_status > 1)){
2831         return ERROR_CODE_COMMAND_DISALLOWED;
2832     }
2833 
2834     if ( (registration_status == 0) && (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT)){
2835 
2836         // if network goes away wihle a call is active:
2837         // - the  call gets dropped
2838         // - we send NO CARRIER
2839         // NOTE: the CALL=0 has to be sent before NO CARRIER
2840 
2841         hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2842 
2843         btstack_linked_list_iterator_t it;
2844         btstack_linked_list_iterator_init(&it, hfp_get_connections());
2845         while (btstack_linked_list_iterator_has_next(&it)){
2846             hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2847             hfp_connection->ag_send_no_carrier = true;
2848         }
2849     }
2850     hfp_ag_set_ag_indicator("service", registration_status);
2851     return ERROR_CODE_SUCCESS;
2852 }
2853 
2854 uint8_t hfp_ag_set_signal_strength(int signal_strength){
2855     if ((signal_strength < 0) || (signal_strength > 5)){
2856         return ERROR_CODE_COMMAND_DISALLOWED;
2857     }
2858 
2859     hfp_ag_set_ag_indicator("signal", signal_strength);
2860     return ERROR_CODE_SUCCESS;
2861 }
2862 
2863 uint8_t hfp_ag_set_roaming_status(int roaming_status){
2864     if ((roaming_status < 0) || (roaming_status > 1)){
2865         return ERROR_CODE_COMMAND_DISALLOWED;
2866     }
2867 
2868     hfp_ag_set_ag_indicator("roam", roaming_status);
2869     return ERROR_CODE_SUCCESS;
2870 }
2871 
2872 uint8_t hfp_ag_set_battery_level(int battery_level){
2873     if ((battery_level < 0) || (battery_level > 5)){
2874         return ERROR_CODE_COMMAND_DISALLOWED;
2875     }
2876     hfp_ag_set_ag_indicator("battchg", battery_level);
2877     return ERROR_CODE_SUCCESS;
2878 }
2879 
2880 uint8_t hfp_ag_activate_voice_recognition(hci_con_handle_t acl_handle){
2881     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2882     if (!hfp_connection){
2883         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2884     }
2885 
2886     if (hfp_connection->emit_vra_enabled_after_audio_established){
2887         return ERROR_CODE_COMMAND_DISALLOWED;
2888     }
2889 
2890     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2891     bool legacy_vra_supported   = hfp_ag_vra_flag_supported(hfp_connection);
2892     if (!enhanced_vra_supported && !legacy_vra_supported){
2893         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2894     }
2895 
2896     if (!hfp_ag_can_activate_voice_recognition(hfp_connection)){
2897         return ERROR_CODE_COMMAND_DISALLOWED;
2898     }
2899 
2900     hfp_connection->ag_activate_voice_recognition_value = 1;
2901     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED;
2902     hfp_connection->enhanced_voice_recognition_enabled = enhanced_vra_supported;
2903     hfp_connection->ag_audio_connection_opened_before_vra = hfp_ag_is_audio_connection_active(hfp_connection);
2904     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2905     hfp_connection->ag_vra_send_command = true;
2906     hfp_ag_run_for_context(hfp_connection);
2907     return ERROR_CODE_SUCCESS;
2908 }
2909 
2910 uint8_t hfp_ag_deactivate_voice_recognition(hci_con_handle_t acl_handle){
2911     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2912     if (!hfp_connection){
2913         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2914     }
2915 
2916     if (hfp_connection->emit_vra_enabled_after_audio_established){
2917         return ERROR_CODE_COMMAND_DISALLOWED;
2918     }
2919 
2920     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2921     bool legacy_vra_supported = hfp_ag_vra_flag_supported(hfp_connection);
2922 
2923     if (!enhanced_vra_supported && !legacy_vra_supported){
2924         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2925     }
2926 
2927     if (!hfp_ag_voice_recognition_session_active(hfp_connection)){
2928         return ERROR_CODE_COMMAND_DISALLOWED;
2929     }
2930 
2931     hfp_connection->ag_activate_voice_recognition_value = 0;
2932     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF;
2933     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2934     hfp_connection->ag_vra_send_command = true;
2935     hfp_ag_run_for_context(hfp_connection);
2936     return ERROR_CODE_SUCCESS;
2937 }
2938 
2939 static uint8_t hfp_ag_enhanced_voice_recognition_send_state(hci_con_handle_t acl_handle, hfp_voice_recognition_state_t state){
2940     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2941     if (!hfp_connection){
2942         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2943     }
2944 
2945     if (hfp_connection->emit_vra_enabled_after_audio_established){
2946         return ERROR_CODE_COMMAND_DISALLOWED;
2947     }
2948 
2949     if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED){
2950         return ERROR_CODE_COMMAND_DISALLOWED;
2951     }
2952 
2953     if (hfp_connection->vra_state != HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
2954         return ERROR_CODE_COMMAND_DISALLOWED;
2955     }
2956 
2957     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2958     if (!enhanced_vra_supported ){
2959         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2960     }
2961 
2962 
2963     hfp_connection->ag_vra_state = state;
2964     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_STATUS;
2965     hfp_connection->ag_vra_send_command = true;
2966     hfp_ag_run_for_context(hfp_connection);
2967     return ERROR_CODE_SUCCESS;
2968 }
2969 
2970 uint8_t hfp_ag_enhanced_voice_recognition_report_sending_audio(hci_con_handle_t acl_handle){
2971     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_STARTING_SOUND);
2972 }
2973 uint8_t hfp_ag_enhanced_voice_recognition_report_ready_for_audio(hci_con_handle_t acl_handle){
2974     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_READY_TO_ACCEPT_AUDIO_INPUT);
2975 }
2976 uint8_t hfp_ag_enhanced_voice_recognition_report_processing_input(hci_con_handle_t acl_handle){
2977     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_PROCESSING_AUDIO_INPUT);
2978 }
2979 
2980 
2981 uint8_t hfp_ag_enhanced_voice_recognition_send_message(hci_con_handle_t acl_handle, hfp_voice_recognition_state_t state, hfp_voice_recognition_message_t msg){
2982     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2983     if (!hfp_connection){
2984         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2985     }
2986 
2987     if (hfp_connection->emit_vra_enabled_after_audio_established){
2988         return ERROR_CODE_COMMAND_DISALLOWED;
2989     }
2990 
2991     if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED){
2992         return ERROR_CODE_COMMAND_DISALLOWED;
2993     }
2994 
2995     if (hfp_connection->vra_state != HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
2996         return ERROR_CODE_COMMAND_DISALLOWED;
2997     }
2998 
2999     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
3000     if (!enhanced_vra_supported ){
3001         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3002     }
3003 
3004     bool enhanced_vra_msg_supported = hfp_ag_can_send_enhanced_vra_message_flag_supported(hfp_connection);
3005     if (!enhanced_vra_msg_supported ){
3006         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3007     }
3008 
3009     uint16_t message_len = (uint16_t) strlen(msg.text);
3010 
3011     if (message_len > HFP_MAX_VR_TEXT_SIZE){
3012         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3013     }
3014 
3015     if ((HFP_VR_TEXT_HEADER_SIZE + message_len) > hfp_connection->rfcomm_mtu){
3016         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3017     }
3018 
3019     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_MSG;
3020     hfp_connection->ag_msg = msg;
3021     hfp_connection->ag_vra_state = state;
3022     hfp_connection->ag_vra_send_command = true;
3023     hfp_ag_run_for_context(hfp_connection);
3024 
3025     return ERROR_CODE_SUCCESS;
3026 }
3027 
3028 
3029 uint8_t hfp_ag_set_microphone_gain(hci_con_handle_t acl_handle, int gain){
3030     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3031     if (!hfp_connection){
3032         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3033     }
3034 
3035     if ((gain < 0) || (gain > 15)){
3036         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
3037         return ERROR_CODE_COMMAND_DISALLOWED;
3038     }
3039 
3040     if (hfp_connection->microphone_gain != gain){
3041         hfp_connection->microphone_gain = gain;
3042         hfp_connection->send_microphone_gain = 1;
3043     }
3044     hfp_ag_run_for_context(hfp_connection);
3045     return ERROR_CODE_SUCCESS;
3046 }
3047 
3048 uint8_t hfp_ag_set_speaker_gain(hci_con_handle_t acl_handle, int gain){
3049     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3050     if (!hfp_connection){
3051         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3052     }
3053 
3054     if ((gain < 0) || (gain > 15)){
3055         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
3056         return ERROR_CODE_COMMAND_DISALLOWED;
3057     }
3058 
3059     if (hfp_connection->speaker_gain != gain){
3060         hfp_connection->speaker_gain = gain;
3061         hfp_connection->send_speaker_gain = 1;
3062     }
3063     hfp_ag_run_for_context(hfp_connection);
3064     return ERROR_CODE_SUCCESS;
3065 }
3066 
3067 uint8_t hfp_ag_send_phone_number_for_voice_tag(hci_con_handle_t acl_handle, const char * number){
3068     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3069     if (!hfp_connection){
3070         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3071     }
3072 
3073     hfp_ag_set_clip(0, number);
3074     hfp_connection->send_phone_number_for_voice_tag = 1;
3075     return ERROR_CODE_SUCCESS;
3076 }
3077 
3078 uint8_t hfp_ag_reject_phone_number_for_voice_tag(hci_con_handle_t acl_handle){
3079     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3080     if (!hfp_connection){
3081         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3082     }
3083 
3084     hfp_connection->send_error = 1;
3085     return ERROR_CODE_SUCCESS;
3086 }
3087 
3088 uint8_t hfp_ag_send_dtmf_code_done(hci_con_handle_t acl_handle){
3089     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3090     if (!hfp_connection){
3091         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3092     }
3093 
3094     hfp_connection->ok_pending = 1;
3095     return ERROR_CODE_SUCCESS;
3096 }
3097 
3098 void hfp_ag_set_subcriber_number_information(hfp_phone_number_t * numbers, int numbers_count){
3099     hfp_ag_subscriber_numbers = numbers;
3100     hfp_ag_subscriber_numbers_count = numbers_count;
3101 }
3102 
3103 void hfp_ag_clear_last_dialed_number(void){
3104     hfp_gsm_clear_last_dialed_number();
3105 }
3106 
3107 void hfp_ag_set_last_dialed_number(const char * number){
3108     hfp_gsm_set_last_dialed_number(number);
3109 }
3110 
3111 uint8_t hfp_ag_notify_incoming_call_waiting(hci_con_handle_t acl_handle){
3112     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3113     if (!hfp_connection){
3114         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3115     }
3116 
3117     if (!hfp_connection->call_waiting_notification_enabled){
3118         return ERROR_CODE_COMMAND_DISALLOWED;
3119     }
3120 
3121     hfp_connection->ag_notify_incoming_call_waiting = 1;
3122     hfp_ag_run_for_context(hfp_connection);
3123     return ERROR_CODE_SUCCESS;
3124 }
3125 
3126 void hfp_ag_create_sdp_record(uint8_t * service, uint32_t service_record_handle, int rfcomm_channel_nr, const char * name, uint8_t ability_to_reject_call, uint16_t supported_features, int wide_band_speech){
3127 	if (!name){
3128 		name = hfp_ag_default_service_name;
3129 	}
3130 	hfp_create_sdp_record(service, service_record_handle, BLUETOOTH_SERVICE_CLASS_HANDSFREE_AUDIO_GATEWAY, rfcomm_channel_nr, name);
3131 
3132 	/*
3133 	 * 0x01 – Ability to reject a call
3134 	 * 0x00 – No ability to reject a call
3135 	 */
3136 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0301);    // Hands-Free Profile - Network
3137 	de_add_number(service, DE_UINT, DE_SIZE_8, ability_to_reject_call);
3138 
3139 	// Construct SupportedFeatures for SDP bitmap:
3140 	//
3141 	// "The values of the “SupportedFeatures” bitmap given in Table 5.4 shall be the same as the values
3142 	//  of the Bits 0 to 4 of the unsolicited result code +BRSF"
3143 	//
3144 	// Wide band speech (bit 5) requires Codec negotiation
3145 	//
3146 	uint16_t sdp_features = supported_features & 0x1f;
3147 	if ( (wide_band_speech == 1) && (supported_features & (1 << HFP_AGSF_CODEC_NEGOTIATION))){
3148 		sdp_features |= 1 << 5;
3149 	}
3150 
3151     if (supported_features & (1 << HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS)){
3152         sdp_features |= 1 << 6;
3153     }
3154 
3155     if (supported_features & (1 << HFP_AGSF_VOICE_RECOGNITION_TEXT)){
3156         sdp_features |= 1 << 7;
3157     }
3158 
3159 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);    // Hands-Free Profile - SupportedFeatures
3160 	de_add_number(service, DE_UINT, DE_SIZE_16, sdp_features);
3161 }
3162 
3163 void hfp_ag_register_packet_handler(btstack_packet_handler_t callback){
3164 	btstack_assert(callback != NULL);
3165 
3166 	hfp_ag_callback = callback;
3167 	hfp_set_ag_callback(callback);
3168 }
3169 
3170 void hfp_ag_register_custom_call_sm_handler(bool (*handler)(hfp_ag_call_event_t event)){
3171     hfp_ag_custom_call_sm_handler = handler;
3172 }
3173