xref: /btstack/src/classic/hfp_ag.c (revision cf7250aa3d6090314187d303f46421dd69a5eef4)
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 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
554     if (hfp_supports_codec(HFP_CODEC_LC3_SWB, hfp_ag_codecs_nr, hfp_ag_codecs)){
555         if (hfp_supports_codec(HFP_CODEC_LC3_SWB, hfp_connection->remote_codecs_nr, hfp_connection->remote_codecs)){
556             return HFP_CODEC_LC3_SWB;
557         }
558     }
559 #endif
560 
561 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
562     if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_ag_codecs_nr, hfp_ag_codecs)){
563         if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_connection->remote_codecs_nr, hfp_connection->remote_codecs)){
564             return HFP_CODEC_MSBC;
565         }
566     }
567 #endif
568 
569     return HFP_CODEC_CVSD;
570 }
571 
572 /* state machines */
573 
574 static uint8_t hfp_ag_esco_s4_supported(hfp_connection_t * hfp_connection){
575     return (hfp_connection->remote_supported_features & (1<<HFP_HFSF_ESCO_S4)) &&  (hfp_ag_supported_features & (1 << HFP_AGSF_ESCO_S4));
576 }
577 
578 static int codecs_exchange_state_machine(hfp_connection_t * hfp_connection){
579     /* events ( == commands):
580         HFP_CMD_AVAILABLE_CODECS == received AT+BAC with list of codecs
581         HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
582             hf_trigger_codec_connection_setup == received BCC
583             ag_trigger_codec_connection_setup == received from AG to send BCS
584         HFP_CMD_HF_CONFIRMED_CODEC == received AT+BCS
585     */
586     switch (hfp_connection->codecs_state){
587         case HFP_CODECS_EXCHANGED:
588             if (hfp_connection->command == HFP_CMD_AVAILABLE_CODECS){
589                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
590                 return 1;
591             }
592             break;
593 
594         case HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE:
595         case HFP_CODECS_AG_RESEND_COMMON_CODEC:
596             hfp_connection->ag_send_common_codec = true;
597             break;
598         default:
599             break;
600     }
601 
602     if (hfp_connection->ag_send_common_codec){
603         hfp_connection->ag_send_common_codec = false;
604         hfp_connection->codecs_state = HFP_CODECS_AG_SENT_COMMON_CODEC;
605         hfp_connection->suggested_codec = hfp_ag_suggest_codec(hfp_connection);
606         hfp_ag_send_suggest_codec_cmd(hfp_connection->rfcomm_cid, hfp_connection->suggested_codec);
607         return 1;
608     }
609 
610     switch (hfp_connection->command){
611         case HFP_CMD_AVAILABLE_CODECS:
612             if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED){
613                 hfp_connection->codecs_state = HFP_CODECS_RECEIVED_LIST;
614                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
615                 return 1;
616             }
617 
618             switch (hfp_connection->codecs_state){
619                 case HFP_CODECS_AG_SENT_COMMON_CODEC:
620                     hfp_connection->codecs_state = HFP_CODECS_AG_RESEND_COMMON_CODEC;
621                     break;
622                 default:
623                     break;
624             }
625             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
626             return 1;
627 
628         case HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
629             hfp_connection->codecs_state = HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE;
630             hfp_connection->establish_audio_connection = 1;
631             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
632             return 1;
633 
634         case HFP_CMD_HF_CONFIRMED_CODEC:
635             if (hfp_connection->codec_confirmed != hfp_connection->suggested_codec){
636                 hfp_connection->codecs_state = HFP_CODECS_ERROR;
637                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
638                 return 1;
639             }
640             hfp_connection->negotiated_codec = hfp_connection->codec_confirmed;
641             hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
642             log_info("hfp: codec confirmed: %s", (hfp_connection->negotiated_codec == HFP_CODEC_MSBC) ? "mSBC" : "CVSD");
643             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
644             // now, pick link settings
645             hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
646 #ifdef ENABLE_CC256X_ASSISTED_HFP
647             hfp_cc256x_prepare_for_sco(hfp_connection);
648 #endif
649 #ifdef ENABLE_RTK_PCM_WBS
650             hfp_connection->rtk_send_sco_config = true;
651 #endif
652             return 1;
653         default:
654             break;
655     }
656     return 0;
657 }
658 
659 static void hfp_ag_slc_established(hfp_connection_t * hfp_connection){
660     hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
661     hfp_emit_slc_connection_event(hfp_connection->local_role, 0, hfp_connection->acl_handle, hfp_connection->remote_addr);
662 
663     // HFP 4.35: "When [...] a new Service Level Connection is established all indicators are activated by default."
664     uint16_t i;
665     for (i=0;i<hfp_connection->ag_indicators_nr;i++){
666         hfp_connection->ag_indicators[i].enabled = 1;
667     }
668 
669     // if active call exist, set per-hfp_connection state active, too (when audio is on)
670     if (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT){
671         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
672     }
673     // if AG is ringing, also start ringing on the HF
674     if (hfp_gsm_call_status() == HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS){
675         switch (hfp_gsm_callsetup_status()){
676             case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
677                 hfp_ag_hf_start_ringing_incoming(hfp_connection);
678                 break;
679             case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
680                 hfp_ag_hf_start_ringing_outgoing(hfp_connection);
681                 break;
682             default:
683                 break;
684         }
685     }
686 }
687 
688 static int hfp_ag_run_for_context_service_level_connection(hfp_connection_t * hfp_connection){
689     // log_info("hfp_ag_run_for_context_service_level_connection state %u, command %u", hfp_connection->state, hfp_connection->command);
690     if (hfp_connection->state >= HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) return 0;
691     int sent = 0;
692     switch(hfp_connection->command){
693         case HFP_CMD_SUPPORTED_FEATURES:
694             switch(hfp_connection->state){
695                 case HFP_W4_EXCHANGE_SUPPORTED_FEATURES:
696                 case HFP_EXCHANGE_SUPPORTED_FEATURES:
697                     hfp_hf_drop_mSBC_if_eSCO_not_supported(hfp_ag_codecs, &hfp_ag_codecs_nr);
698                     if (has_codec_negotiation_feature(hfp_connection)){
699                         hfp_connection->state = HFP_W4_NOTIFY_ON_CODECS;
700                     } else {
701                         hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
702                     }
703                     hfp_ag_exchange_supported_features_cmd(hfp_connection->rfcomm_cid);
704                     return 1;
705                 default:
706                     break;
707             }
708             break;
709         case HFP_CMD_AVAILABLE_CODECS:
710             sent = codecs_exchange_state_machine(hfp_connection);
711             if (hfp_connection->codecs_state == HFP_CODECS_RECEIVED_LIST){
712                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
713             }
714             return sent;
715 
716         case HFP_CMD_RETRIEVE_AG_INDICATORS:
717             if (hfp_connection->state == HFP_W4_RETRIEVE_INDICATORS) {
718                 // HF requested AG Indicators and we did expect it
719                 hfp_connection->send_ag_indicators_segment = 0;
720                 hfp_connection->state = HFP_RETRIEVE_INDICATORS;
721                 // continue below in state switch
722             }
723             break;
724 
725         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
726             if (hfp_connection->state != HFP_W4_RETRIEVE_INDICATORS_STATUS) break;
727             hfp_connection->state = HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE;
728             hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
729             return 1;
730 
731         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
732             if (hfp_connection->state != HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE) break;
733             if (has_call_waiting_and_3way_calling_feature(hfp_connection)){
734                 hfp_connection->state = HFP_W4_RETRIEVE_CAN_HOLD_CALL;
735             } else if (has_hf_indicators_feature(hfp_connection)){
736                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
737             } else {
738                 hfp_ag_slc_established(hfp_connection);
739             }
740             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
741             return 1;
742 
743         case HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES:
744             if (hfp_connection->state != HFP_W4_RETRIEVE_CAN_HOLD_CALL) break;
745             if (has_hf_indicators_feature(hfp_connection)){
746                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
747             }
748             hfp_ag_send_retrieve_can_hold_call_cmd(hfp_connection->rfcomm_cid);
749             if (!has_hf_indicators_feature(hfp_connection)){
750                 hfp_ag_slc_established(hfp_connection);
751             }
752             return 1;
753 
754         case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
755             if (hfp_connection->state != HFP_W4_LIST_GENERIC_STATUS_INDICATORS) break;
756             hfp_connection->state = HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS;
757             hfp_ag_send_list_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
758             return 1;
759 
760         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
761             if (hfp_connection->state != HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS) break;
762             hfp_connection->state = HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS;
763             hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
764             return 1;
765 
766         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
767             if (hfp_connection->state != HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS) break;
768             hfp_ag_slc_established(hfp_connection);
769             hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
770             return 1;
771         default:
772             break;
773     }
774 
775     switch (hfp_connection->state){
776         case HFP_RETRIEVE_INDICATORS: {
777             int next_segment = hfp_ag_send_retrieve_indicators_cmd_via_generator(hfp_connection->rfcomm_cid, hfp_connection, hfp_connection->send_ag_indicators_segment);
778             int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
779             log_info("HFP_CMD_RETRIEVE_AG_INDICATORS next segment %u, num_segments %u", next_segment, num_segments);
780             if (next_segment < num_segments){
781                 // prepare sending of next segment
782                 hfp_connection->send_ag_indicators_segment = next_segment;
783                 log_info("HFP_CMD_RETRIEVE_AG_INDICATORS more. command %u, next seg %u", hfp_connection->command, next_segment);
784             } else {
785                 // done, go to next state
786                 hfp_connection->send_ag_indicators_segment = 0;
787                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS_STATUS;
788             }
789             return 1;
790         }
791         default:
792             break;
793     }
794     return 0;
795 }
796 
797 static bool hfp_ag_vra_flag_supported(hfp_connection_t * hfp_connection){
798     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION);
799     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION);
800     return hf && ag;
801 }
802 
803 static bool hfp_ag_enhanced_vra_flag_supported(hfp_connection_t * hfp_connection){
804     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS);
805     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_ENHANCED_VOICE_RECOGNITION_STATUS);
806     return hf && ag;
807 }
808 
809 static bool hfp_ag_can_send_enhanced_vra_message_flag_supported(hfp_connection_t * hfp_connection){
810     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_VOICE_RECOGNITION_TEXT);
811     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_TEXT);
812     return hf && ag;
813 }
814 
815 static bool hfp_ag_can_activate_voice_recognition(hfp_connection_t * hfp_connection){
816     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED || hfp_connection->state > HFP_AUDIO_CONNECTION_ESTABLISHED){
817         return false;
818     }
819     if (hfp_connection->vra_state != HFP_VRA_VOICE_RECOGNITION_OFF){
820         return false;
821     }
822     if (hfp_connection->ag_vra_send_command){
823         return false;
824     }
825     return true;
826 }
827 
828 static bool hfp_ag_voice_recognition_session_active(hfp_connection_t * hfp_connection){
829     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED || hfp_connection->state > HFP_AUDIO_CONNECTION_ESTABLISHED){
830         return false;
831     }
832     if (hfp_connection->vra_state != HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
833         if (hfp_connection->vra_state == HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
834             return true;
835         }
836         return false;
837     }
838     return true;
839 }
840 
841 static bool hfp_ag_is_audio_connection_active(hfp_connection_t * hfp_connection){
842     switch (hfp_connection->state){
843         case HFP_W2_CONNECT_SCO:
844         case HFP_W4_SCO_CONNECTED:
845         case HFP_AUDIO_CONNECTION_ESTABLISHED:
846             return true;
847         default:
848             return false;
849     }
850 }
851 
852 static void hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection_t * hfp_connection, uint8_t status){
853     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
854 
855     uint8_t event[6];
856     event[0] = HCI_EVENT_HFP_META;
857     event[1] = sizeof(event) - 2;
858     event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_AG_MESSAGE_SENT;
859     little_endian_store_16(event, 3, acl_handle);
860     event[5] = status;
861     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
862 }
863 
864 
865 static void hfp_ag_emit_hf_indicator_value(hfp_connection_t * hfp_connection, uint16_t uuid, uint8_t value){
866     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
867 
868     uint8_t event[8];
869     event[0] = HCI_EVENT_HFP_META;
870     event[1] = sizeof(event) - 2;
871     event[2] = HFP_SUBEVENT_HF_INDICATOR;
872     little_endian_store_16(event, 3, acl_handle);
873     little_endian_store_16(event, 5, uuid);
874     event[7] = value;
875     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
876 }
877 
878 static void hfp_ag_emit_general_simple_event(uint8_t event_subtype){
879     if (!hfp_ag_callback) return;
880 
881     uint8_t event[5];
882     event[0] = HCI_EVENT_HFP_META;
883     event[1] = sizeof(event) - 2;
884     event[2] = event_subtype;
885     little_endian_store_16(event, 3, HCI_CON_HANDLE_INVALID);
886     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
887 }
888 
889 static void hfp_ag_emit_custom_command_event(hfp_connection_t * hfp_connection){
890     btstack_assert(sizeof(hfp_connection->line_buffer) < (255-5));
891 
892     uint16_t line_len = strlen((const char*)hfp_connection->line_buffer) + 1;
893     uint8_t event[7 + sizeof(hfp_connection->line_buffer)];
894     event[0] = HCI_EVENT_HFP_META;
895     event[1] = 5 + line_len;
896     event[2] = HFP_SUBEVENT_CUSTOM_AT_COMMAND;
897     little_endian_store_16(event, 3, hfp_connection->acl_handle);
898     little_endian_store_16(event, 5, hfp_connection->ag_custom_at_command_id);
899     memcpy(&event[7], hfp_connection->line_buffer, line_len);
900     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, 7 + line_len);
901 }
902 
903 // @return status
904 static uint8_t hfp_ag_vra_state_machine_two(hfp_connection_t * hfp_connection){
905     uint8_t status = ERROR_CODE_SUCCESS;
906     switch (hfp_connection->vra_state_requested){
907         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO:
908             if (!hfp_ag_is_audio_connection_active(hfp_connection)){
909                 status = hfp_ag_setup_audio_connection(hfp_connection);
910                 if (status != ERROR_CODE_SUCCESS){
911                     hfp_connection->vra_state_requested = hfp_connection->vra_state;
912                     hfp_emit_voice_recognition_enabled(hfp_connection, status);
913                     break;
914                 }
915             }
916             hfp_connection->enhanced_voice_recognition_enabled = true;
917             hfp_connection->vra_state = HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO;
918             hfp_connection->vra_state_requested = hfp_connection->vra_state;
919             hfp_emit_enhanced_voice_recognition_hf_ready_for_audio_event(hfp_connection, ERROR_CODE_SUCCESS);
920             break;
921 
922         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF:
923             hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_OFF;
924             hfp_connection->vra_state_requested = hfp_connection->vra_state;
925 
926             // release audio connection only if it was opened after audio VR activated
927             if (hfp_ag_is_audio_connection_active(hfp_connection) && !hfp_connection->ag_audio_connection_opened_before_vra){
928                 hfp_trigger_release_audio_connection(hfp_connection);
929             }
930 
931             hfp_emit_voice_recognition_disabled(hfp_connection, ERROR_CODE_SUCCESS);
932             break;
933 
934         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED:
935             // open only if audio connection does not already exist
936             if (!hfp_ag_is_audio_connection_active(hfp_connection)){
937                 status = hfp_ag_setup_audio_connection(hfp_connection);
938                 if (status != ERROR_CODE_SUCCESS){
939                     hfp_connection->vra_state_requested = hfp_connection->vra_state;
940                     hfp_emit_voice_recognition_enabled(hfp_connection, status);
941                     break;
942                 }
943             }
944 
945             hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_ACTIVATED;
946             hfp_connection->vra_state_requested = hfp_connection->vra_state;
947             hfp_connection->enhanced_voice_recognition_enabled = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
948 
949             if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
950                 hfp_emit_voice_recognition_enabled(hfp_connection, ERROR_CODE_SUCCESS);
951             } else {
952                 hfp_connection->emit_vra_enabled_after_audio_established = true;
953             }
954             break;
955 
956         default:
957             break;
958     }
959     return status;
960 }
961 
962 static uint8_t hfp_ag_vra_send_command(hfp_connection_t * hfp_connection){
963     uint8_t done = 0;
964     uint8_t status;
965 
966     switch (hfp_connection->vra_state_requested){
967         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_MSG:
968             done = hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection);
969             if (done == 0){
970                 hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection, ERROR_CODE_UNSPECIFIED_ERROR);
971             } else {
972                 hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection, ERROR_CODE_SUCCESS);
973             }
974             hfp_connection->vra_state_requested = hfp_connection->vra_state;
975             return done;
976 
977         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_STATUS:
978             done = hfp_ag_send_enhanced_voice_recognition_state_cmd(hfp_connection);
979             if (done == 0){
980                 hfp_emit_enhanced_voice_recognition_state_event(hfp_connection, ERROR_CODE_UNSPECIFIED_ERROR);
981             } else {
982                 hfp_emit_enhanced_voice_recognition_state_event(hfp_connection, ERROR_CODE_SUCCESS);
983             }
984             hfp_connection->vra_state_requested = hfp_connection->vra_state;
985             return done;
986 
987         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED:
988         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF:
989             done = hfp_ag_send_voice_recognition_cmd(hfp_connection, hfp_connection->ag_activate_voice_recognition_value);
990             if (done == 0){
991                 hfp_connection->vra_state_requested = hfp_connection->vra_state;
992 
993                 if (hfp_connection->ag_activate_voice_recognition_value == 1){
994                     hfp_emit_voice_recognition_enabled(hfp_connection, done);
995                 } else {
996                     hfp_emit_voice_recognition_disabled(hfp_connection, done);
997                 }
998                 return 0;
999             }
1000             status = hfp_ag_vra_state_machine_two(hfp_connection);
1001             return (status == ERROR_CODE_SUCCESS) ? 1 : 0;
1002 
1003         default:
1004             log_error("state %u", hfp_connection->vra_state_requested);
1005             btstack_assert(false);
1006             return 0;
1007     }
1008 }
1009 
1010 static int hfp_ag_voice_recognition_state_machine(hfp_connection_t * hfp_connection){
1011     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) {
1012         return 0;
1013     }
1014     int done = 0;
1015     uint8_t status;
1016 
1017     // VRA action initiated by AG
1018     if (hfp_connection->ag_vra_send_command){
1019         hfp_connection->ag_vra_send_command = false;
1020         return hfp_ag_vra_send_command(hfp_connection);
1021     }
1022 
1023     if (hfp_connection->ag_vra_requested_by_hf){
1024         hfp_connection->ag_vra_requested_by_hf = false;
1025 
1026         // HF initiatied voice recognition, parser extracted activation value
1027         switch (hfp_connection->ag_activate_voice_recognition_value){
1028             case 0:
1029                 if (hfp_ag_voice_recognition_session_active(hfp_connection)){
1030                     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF;
1031                     done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1032                 }
1033                 break;
1034 
1035                 case 1:
1036                     if (hfp_ag_can_activate_voice_recognition(hfp_connection)){
1037                         hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED;
1038                         done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1039                     }
1040                     break;
1041 
1042                     case 2:
1043                         if (hfp_ag_voice_recognition_session_active(hfp_connection)){
1044                             hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO;
1045                             done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1046                         }
1047                         break;
1048                         default:
1049                             break;
1050         }
1051         if (done == 0){
1052             hfp_connection->vra_state_requested = hfp_connection->vra_state;
1053             done = hfp_ag_send_error(hfp_connection->rfcomm_cid);
1054             return 1;
1055         }
1056 
1057         status = hfp_ag_vra_state_machine_two(hfp_connection);
1058         return (status == ERROR_CODE_SUCCESS) ? 1 : 0;
1059     }
1060 
1061     return 0;
1062 }
1063 
1064 static int hfp_ag_run_for_context_service_level_connection_queries(hfp_connection_t * hfp_connection){
1065     int sent = codecs_exchange_state_machine(hfp_connection);
1066     if (sent) return 1;
1067 
1068     if (hfp_connection->ag_send_in_band_ring_tone_setting){
1069         hfp_connection->ag_send_in_band_ring_tone_setting = false;
1070         hfp_ag_send_change_in_band_ring_tone_setting_cmd(hfp_connection->rfcomm_cid);
1071         return 1;
1072     }
1073 
1074     switch(hfp_connection->command){
1075         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1076             hfp_ag_send_report_network_operator_name_cmd(hfp_connection->rfcomm_cid, hfp_connection->network_operator);
1077             return 1;
1078         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
1079             if (hfp_connection->network_operator.format != 0){
1080                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
1081             } else {
1082                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1083             }
1084             return 1;
1085         case HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE:
1086             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1087             return 1;
1088         case HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR:
1089             if (hfp_connection->extended_audio_gateway_error){
1090                 hfp_connection->extended_audio_gateway_error = 0;
1091                 hfp_ag_send_report_extended_audio_gateway_error(hfp_connection->rfcomm_cid, hfp_connection->extended_audio_gateway_error_value);
1092                 return 1;
1093             }
1094             break;
1095         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
1096             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1097             return 1;
1098         default:
1099             break;
1100     }
1101     return 0;
1102 }
1103 
1104 static int hfp_ag_run_for_audio_connection(hfp_connection_t * hfp_connection){
1105     if ((hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) ||
1106         (hfp_connection->state > HFP_W2_DISCONNECT_SCO)) return 0;
1107 
1108     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1109 
1110     if (hfp_connection->release_audio_connection){
1111         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
1112         hfp_connection->release_audio_connection = 0;
1113         gap_disconnect(hfp_connection->sco_handle);
1114         return 1;
1115     }
1116 
1117     // accept incoming audio connection (codec negotiation is not used)
1118     if (hfp_connection->accept_sco){
1119         // notify about codec selection if not done already
1120         if (hfp_connection->negotiated_codec == 0){
1121             hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
1122         }
1123         //
1124         bool incoming_eSCO = hfp_connection->accept_sco == 2;
1125         hfp_connection->accept_sco = 0;
1126         hfp_connection->state = HFP_W4_SCO_CONNECTED;
1127         hfp_accept_synchronous_connection(hfp_connection, incoming_eSCO);
1128         return 1;
1129     }
1130 
1131     // run codecs exchange
1132     int sent = codecs_exchange_state_machine(hfp_connection);
1133     if (sent) return 1;
1134 
1135     if (hfp_connection->codecs_state != HFP_CODECS_EXCHANGED) return 0;
1136     if (hfp_connection->establish_audio_connection){
1137         hfp_connection->state = HFP_W4_SCO_CONNECTED;
1138         hfp_connection->establish_audio_connection = 0;
1139         hfp_setup_synchronous_connection(hfp_connection);
1140         return 1;
1141     }
1142     return 0;
1143 }
1144 
1145 static void hfp_ag_set_callsetup_indicator(void){
1146     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callsetup");
1147     if (!indicator){
1148         log_error("hfp_ag_set_callsetup_indicator: callsetup indicator is missing");
1149         return;
1150     };
1151     indicator->status = hfp_gsm_callsetup_status();
1152 }
1153 
1154 static void hfp_ag_set_callheld_indicator(void){
1155     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callheld");
1156     if (!indicator){
1157         log_error("hfp_ag_set_callheld_state: callheld indicator is missing");
1158         return;
1159     };
1160     indicator->status = hfp_gsm_callheld_status();
1161 }
1162 
1163 //
1164 // transition implementations for hfp_ag_call_state_machine
1165 //
1166 
1167 static void hfp_ag_hf_start_ringing_incoming(hfp_connection_t * hfp_connection){
1168     if (use_in_band_tone()){
1169         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING;
1170         hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1171     } else {
1172         hfp_connection->call_state = HFP_CALL_INCOMING_RINGING;
1173     }
1174 }
1175 
1176 static void hfp_ag_hf_start_ringing_outgoing(hfp_connection_t * hfp_connection){
1177     hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1178 }
1179 
1180 static void hfp_ag_hf_stop_ringing(hfp_connection_t * hfp_connection){
1181     hfp_connection->ag_ring = 0;
1182     hfp_connection->ag_send_clip = 0;
1183 }
1184 
1185 
1186 static void hfp_ag_trigger_incoming_call_during_active_one(void){
1187     btstack_linked_list_iterator_t it;
1188     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1189     while (btstack_linked_list_iterator_has_next(&it)){
1190         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1191         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1192         if (hfp_connection->call_state != HFP_CALL_ACTIVE) continue;
1193 
1194         hfp_connection->call_state = HFP_CALL_W2_SEND_CALL_WAITING;
1195         hfp_ag_run_for_context(hfp_connection);
1196     }
1197 }
1198 
1199 static void hfp_ag_trigger_ring_and_clip(void) {
1200     btstack_linked_list_iterator_t it;
1201     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1202     while (btstack_linked_list_iterator_has_next(&it)){
1203         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1204         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1205         switch (hfp_connection->call_state){
1206             case HFP_CALL_INCOMING_RINGING:
1207             case HFP_CALL_OUTGOING_RINGING:
1208             case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1209                 // Queue RING on this connection
1210                 hfp_connection->ag_ring = 1;
1211 
1212                 // HFP v1.8, 4.23 Calling Line Identification (CLI) Notification
1213                 // "If the calling subscriber number information is available from the network, the AG shall issue the
1214                 // +CLIP unsolicited result code just after every RING indication when the HF is alerted in an incoming call."
1215                 hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
1216 
1217                 // trigger next message
1218                 rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1219                 break;
1220             default:
1221                 break;
1222         }
1223     }
1224 }
1225 
1226 // trigger RING and CLIP messages on connections that are ringing
1227 static void hfp_ag_ring_timeout_handler(btstack_timer_source_t * timer){
1228     hfp_ag_trigger_ring_and_clip();
1229 
1230     btstack_run_loop_set_timer(timer, HFP_RING_PERIOD_MS); // 2 seconds timeout
1231     btstack_run_loop_add_timer(timer);
1232 }
1233 
1234 static void hfp_ag_ring_timeout_stop(void){
1235     btstack_run_loop_remove_timer(&hfp_ag_ring_timeout);
1236 }
1237 
1238 static void hfp_ag_start_ringing(void){
1239     // setup ring timer
1240     btstack_run_loop_remove_timer(&hfp_ag_ring_timeout);
1241     btstack_run_loop_set_timer_handler(&hfp_ag_ring_timeout, hfp_ag_ring_timeout_handler);
1242     btstack_run_loop_set_timer(&hfp_ag_ring_timeout, HFP_RING_PERIOD_MS); // 2 seconds timeout
1243     btstack_run_loop_add_timer(&hfp_ag_ring_timeout);
1244 
1245     // emit start ringing
1246     hfp_ag_emit_general_simple_event(HFP_SUBEVENT_START_RINGING);
1247 
1248     // send initial RING + CLIP
1249     hfp_ag_trigger_ring_and_clip();
1250 }
1251 
1252 static void hfp_ag_stop_ringing(void){
1253     hfp_ag_ring_timeout_stop();
1254     hfp_ag_emit_general_simple_event(HFP_SUBEVENT_STOP_RINGING);
1255 
1256     btstack_linked_list_iterator_t it;
1257     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1258     while (btstack_linked_list_iterator_has_next(&it)){
1259         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1260         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1261         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1262             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1263         hfp_ag_hf_stop_ringing(hfp_connection);
1264     }
1265 }
1266 
1267 static void hfp_ag_trigger_incoming_call_idle(void){
1268     int indicator_index = get_ag_indicator_index_for_name("callsetup");
1269     if (indicator_index < 0) return;
1270 
1271     // update callsetup state in connections
1272     btstack_linked_list_iterator_t it;
1273     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1274     while (btstack_linked_list_iterator_has_next(&it)){
1275         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1276         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1277         if (hfp_connection->call_state != HFP_CALL_IDLE) continue;
1278 
1279         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1280 
1281         hfp_ag_hf_start_ringing_incoming(hfp_connection);
1282 
1283         hfp_ag_run_for_context(hfp_connection);
1284     }
1285 
1286     // start local ringing - started after connection state has been updated
1287     hfp_ag_start_ringing();
1288 }
1289 
1290 static void hfp_ag_trigger_outgoing_call(void){
1291     btstack_linked_list_iterator_t it;
1292     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1293     while (btstack_linked_list_iterator_has_next(&it)){
1294         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1295         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1296         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1297         if (hfp_connection->call_state == HFP_CALL_IDLE){
1298             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1299         }
1300     }
1301 }
1302 
1303 static void hfp_ag_handle_outgoing_call_accepted(hfp_connection_t * hfp_connection){
1304     hfp_connection->call_state = HFP_CALL_OUTGOING_DIALING;
1305 
1306     // trigger callsetup to be
1307     int put_call_on_hold = hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT;
1308     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ACCEPTED, 0, 0, NULL);
1309 
1310     int indicator_index ;
1311 
1312     hfp_ag_set_callsetup_indicator();
1313     indicator_index = get_ag_indicator_index_for_name("callsetup");
1314     hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1315 
1316     // put current call on hold if active
1317     if (put_call_on_hold){
1318         log_info("AG putting current call on hold for new outgoing call");
1319         hfp_ag_set_callheld_indicator();
1320         indicator_index = get_ag_indicator_index_for_name("callheld");
1321         hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[indicator_index]);
1322     }
1323 
1324     // start audio if needed
1325     hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1326 }
1327 
1328 static void hfp_ag_transfer_indicator(const char * name){
1329     int indicator_index = get_ag_indicator_index_for_name(name);
1330     if (indicator_index < 0) return;
1331 
1332     btstack_linked_list_iterator_t it;
1333     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1334     while (btstack_linked_list_iterator_has_next(&it)){
1335         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1336         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1337         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1338         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1339         hfp_ag_run_for_context(hfp_connection);
1340     }
1341 }
1342 
1343 static void hfp_ag_transfer_callsetup_state(void){
1344     hfp_ag_transfer_indicator("callsetup");
1345 }
1346 
1347 static void hfp_ag_transfer_call_state(void){
1348     hfp_ag_transfer_indicator("call");
1349 }
1350 
1351 static void hfp_ag_transfer_callheld_state(void){
1352     hfp_ag_transfer_indicator("callheld");
1353 }
1354 
1355 static void hfp_ag_hf_accept_call(hfp_connection_t * source){
1356     int call_indicator_index = get_ag_indicator_index_for_name("call");
1357     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1358 
1359     hfp_ag_stop_ringing();
1360 
1361     btstack_linked_list_iterator_t it;
1362     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1363     while (btstack_linked_list_iterator_has_next(&it)){
1364         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1365         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1366         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1367             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1368 
1369         if (hfp_connection == source){
1370 
1371             if (use_in_band_tone()){
1372                 hfp_connection->call_state = HFP_CALL_ACTIVE;
1373             } else {
1374                 hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
1375                 hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1376             }
1377 
1378             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1379             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1380 
1381         } else {
1382             hfp_connection->call_state = HFP_CALL_IDLE;
1383         }
1384         hfp_ag_run_for_context(hfp_connection);
1385     }
1386 }
1387 
1388 static void hfp_ag_ag_accept_call(void){
1389     int call_indicator_index = get_ag_indicator_index_for_name("call");
1390     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1391 
1392     hfp_ag_stop_ringing();
1393 
1394     btstack_linked_list_iterator_t it;
1395     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1396     while (btstack_linked_list_iterator_has_next(&it)){
1397         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1398         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1399         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1400             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1401 
1402         hfp_connection->call_state = HFP_CALL_TRIGGER_AUDIO_CONNECTION;
1403 
1404         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1405         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1406 
1407         hfp_ag_run_for_context(hfp_connection);
1408         break;  // only single
1409     }
1410 }
1411 
1412 static void hfp_ag_trigger_reject_call(void){
1413     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1414 
1415     hfp_ag_stop_ringing();
1416 
1417     btstack_linked_list_iterator_t it;
1418     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1419     while (btstack_linked_list_iterator_has_next(&it)){
1420         hfp_connection_t * connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1421         if (connection->local_role != HFP_ROLE_AG) continue;
1422 
1423         switch (connection->call_state){
1424             case HFP_CALL_INCOMING_RINGING:
1425             case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1426             case HFP_CALL_OUTGOING_RINGING:
1427             case HFP_CALL_OUTGOING_INITIATED:
1428             case HFP_CALL_OUTGOING_DIALING:
1429                 break;
1430             default:
1431                 continue;
1432         }
1433 
1434         connection->call_state = HFP_CALL_IDLE;
1435         connection->ag_indicators_status_update_bitmap = store_bit(connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1436 
1437         if (connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1438             connection->release_audio_connection = 1;
1439         }
1440         hfp_emit_simple_event(connection, HFP_SUBEVENT_CALL_TERMINATED);
1441         hfp_ag_run_for_context(connection);
1442         rfcomm_request_can_send_now_event(connection->rfcomm_cid);
1443     }
1444 }
1445 
1446 static void hfp_ag_trigger_terminate_call(void){
1447     int call_indicator_index = get_ag_indicator_index_for_name("call");
1448 
1449     // no ringing during call
1450 
1451     btstack_linked_list_iterator_t it;
1452     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1453     while (btstack_linked_list_iterator_has_next(&it)){
1454         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1455         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1456         if (hfp_connection->call_state == HFP_CALL_IDLE) continue;
1457 
1458         hfp_connection->call_state = HFP_CALL_IDLE;
1459         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1460 
1461         if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1462             hfp_connection->release_audio_connection = 1;
1463         }
1464 
1465         hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_TERMINATED);
1466         hfp_ag_run_for_context(hfp_connection);
1467         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1468     }
1469 }
1470 
1471 static void hfp_ag_set_call_indicator(void){
1472     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("call");
1473     if (!indicator){
1474         log_error("hfp_ag_set_call_state: call indicator is missing");
1475         return;
1476     };
1477     indicator->status = hfp_gsm_call_status();
1478 }
1479 
1480 static hfp_connection_t * hfp_ag_connection_for_call_state(hfp_call_state_t call_state){
1481     btstack_linked_list_iterator_t it;
1482     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1483     while (btstack_linked_list_iterator_has_next(&it)){
1484         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1485         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1486         if (hfp_connection->call_state == call_state) return hfp_connection;
1487     }
1488     return NULL;
1489 }
1490 
1491 static void hfp_ag_send_response_and_hold_state(hfp_response_and_hold_state_t state){
1492     btstack_linked_list_iterator_t it;
1493     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1494     while (btstack_linked_list_iterator_has_next(&it)){
1495         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1496         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1497         hfp_connection->send_response_and_hold_status = state + 1;
1498     }
1499 }
1500 
1501 static int call_setup_state_machine(hfp_connection_t * hfp_connection){
1502     int indicator_index;
1503     switch (hfp_connection->call_state){
1504         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1505             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1506             // we got event: audio hfp_connection established
1507             hfp_connection->call_state = HFP_CALL_INCOMING_RINGING;
1508             break;
1509         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE:
1510             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1511             // we got event: audio hfp_connection established
1512             hfp_connection->call_state = HFP_CALL_ACTIVE;
1513             break;
1514         case HFP_CALL_W2_SEND_CALL_WAITING:
1515             hfp_connection->call_state = HFP_CALL_W4_CHLD;
1516             hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1517             indicator_index = get_ag_indicator_index_for_name("callsetup");
1518             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1519             break;
1520         default:
1521             break;
1522     }
1523     return 0;
1524 }
1525 
1526 // functions extracted from hfp_ag_call_sm below
1527 static void hfp_ag_handle_reject_outgoing_call(void){
1528     hfp_connection_t * hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1529     if (!hfp_connection){
1530         log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1531         return;
1532     }
1533 
1534     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_REJECTED, 0, 0, NULL);
1535     hfp_connection->call_state = HFP_CALL_IDLE;
1536     hfp_connection->send_error = 1;
1537     hfp_ag_run_for_context(hfp_connection);
1538 }
1539 
1540 // hfp_connection is used to identify originating HF
1541 static void hfp_ag_call_sm(hfp_ag_call_event_t event, hfp_connection_t * hfp_connection){
1542 
1543     // allow to intercept call statemachine events
1544     if (hfp_ag_custom_call_sm_handler != NULL){
1545         bool handle_event = (*hfp_ag_custom_call_sm_handler)(event);
1546         if (!handle_event) return;
1547     }
1548 
1549     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1550     int callheld_indicator_index = get_ag_indicator_index_for_name("callheld");
1551     int call_indicator_index = get_ag_indicator_index_for_name("call");
1552 
1553     switch (event){
1554         case HFP_AG_INCOMING_CALL:
1555             switch (hfp_gsm_call_status()){
1556                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1557                     switch (hfp_gsm_callsetup_status()){
1558                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1559                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1560                             hfp_ag_set_callsetup_indicator();
1561                             hfp_ag_trigger_incoming_call_idle();
1562                             log_info("AG rings");
1563                             break;
1564                         default:
1565                             break;
1566                     }
1567                     break;
1568                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1569                     switch (hfp_gsm_callsetup_status()){
1570                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1571                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1572                             hfp_ag_set_callsetup_indicator();
1573                             hfp_ag_trigger_incoming_call_during_active_one();
1574                             log_info("AG call waiting");
1575                             break;
1576                         default:
1577                             break;
1578                     }
1579                     break;
1580                 default:
1581                     break;
1582             }
1583             break;
1584         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG:
1585             switch (hfp_gsm_call_status()){
1586                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1587                     switch (hfp_gsm_callsetup_status()){
1588                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1589                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1590                             hfp_ag_set_call_indicator();
1591                             hfp_ag_set_callsetup_indicator();
1592                             hfp_ag_ag_accept_call();
1593                             log_info("AG answers call, accept call by GSM");
1594                             break;
1595                         default:
1596                             break;
1597                     }
1598                     break;
1599                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1600                     switch (hfp_gsm_callsetup_status()){
1601                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1602                             log_info("AG: current call is placed on hold, incoming call gets active");
1603                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1604                             hfp_ag_set_callsetup_indicator();
1605                             hfp_ag_set_callheld_indicator();
1606                             hfp_ag_transfer_callsetup_state();
1607                             hfp_ag_transfer_callheld_state();
1608                             break;
1609                         default:
1610                             break;
1611                     }
1612                     break;
1613                 default:
1614                     break;
1615             }
1616             break;
1617 
1618         case HFP_AG_HELD_CALL_JOINED_BY_AG:
1619             switch (hfp_gsm_call_status()){
1620                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1621                     switch (hfp_gsm_callheld_status()){
1622                         case HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED:
1623                             log_info("AG: joining held call with active call");
1624                             hfp_gsm_handler(HFP_AG_HELD_CALL_JOINED_BY_AG, 0, 0, NULL);
1625                             hfp_ag_set_callheld_indicator();
1626                             hfp_ag_transfer_callheld_state();
1627                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1628                             break;
1629                         default:
1630                             break;
1631                     }
1632                     break;
1633                 default:
1634                     break;
1635             }
1636             break;
1637 
1638         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF:
1639             switch (hfp_gsm_call_status()){
1640                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1641                     switch (hfp_gsm_callsetup_status()){
1642                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1643                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, 0, 0, NULL);
1644                             hfp_ag_set_callsetup_indicator();
1645                             hfp_ag_set_call_indicator();
1646                             hfp_ag_hf_accept_call(hfp_connection);
1647                             hfp_connection->ok_pending = 1;
1648                             log_info("HF answers call, accept call by GSM");
1649                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1650                             break;
1651                         default:
1652                             break;
1653                     }
1654                     break;
1655                 default:
1656                     break;
1657             }
1658             break;
1659 
1660         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG:
1661             switch (hfp_gsm_call_status()){
1662                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1663                     switch (hfp_gsm_callsetup_status()){
1664                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1665                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, 0, 0, NULL);
1666                             hfp_ag_response_and_hold_active = true;
1667                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1668                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1669                             // as with regular call
1670                             hfp_ag_set_call_indicator();
1671                             hfp_ag_set_callsetup_indicator();
1672                             hfp_ag_ag_accept_call();
1673                             log_info("AG response and hold - hold by AG");
1674                             break;
1675                         default:
1676                             break;
1677                     }
1678                     break;
1679                 default:
1680                     break;
1681             }
1682             break;
1683 
1684         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF:
1685             switch (hfp_gsm_call_status()){
1686                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1687                     switch (hfp_gsm_callsetup_status()){
1688                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1689                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, 0, 0, NULL);
1690                             hfp_ag_response_and_hold_active = true;
1691                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1692                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1693                             // as with regular call
1694                             hfp_ag_set_call_indicator();
1695                             hfp_ag_set_callsetup_indicator();
1696                             hfp_ag_hf_accept_call(hfp_connection);
1697                             log_info("AG response and hold - hold by HF");
1698                             break;
1699                         default:
1700                             break;
1701                     }
1702                     break;
1703                 default:
1704                     break;
1705             }
1706             break;
1707 
1708         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG:
1709         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF:
1710             if (!hfp_ag_response_and_hold_active) break;
1711             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1712             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, 0, 0, NULL);
1713             hfp_ag_response_and_hold_active = false;
1714             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED;
1715             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1716             log_info("Held Call accepted and active");
1717             break;
1718 
1719         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG:
1720         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF:
1721             if (!hfp_ag_response_and_hold_active) break;
1722             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1723             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, 0, 0, NULL);
1724             hfp_ag_response_and_hold_active = false;
1725             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1726             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1727             // from terminate by ag
1728             hfp_ag_set_call_indicator();
1729             hfp_ag_trigger_terminate_call();
1730             break;
1731 
1732         case HFP_AG_TERMINATE_CALL_BY_HF:
1733             switch (hfp_gsm_call_status()){
1734                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1735                     switch (hfp_gsm_callsetup_status()){
1736                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1737                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1738                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1739                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1740                             hfp_ag_set_callsetup_indicator();
1741                             hfp_ag_transfer_callsetup_state();
1742                             hfp_ag_trigger_reject_call();
1743                             log_info("HF Rejected Incoming call, AG terminate call");
1744                             break;
1745                         default:
1746                             break;
1747                     }
1748                     break;
1749                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1750                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1751                     hfp_ag_set_callsetup_indicator();
1752                     hfp_ag_set_call_indicator();
1753                     hfp_ag_trigger_terminate_call();
1754                     log_info("AG terminate call");
1755                     break;
1756                 default:
1757                     break;
1758             }
1759             break;
1760 
1761         case HFP_AG_TERMINATE_CALL_BY_AG:
1762             switch (hfp_gsm_call_status()){
1763                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1764                     switch (hfp_gsm_callsetup_status()){
1765                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1766                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1767                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1768                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1769                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1770                             hfp_ag_set_callsetup_indicator();
1771                             hfp_ag_trigger_reject_call();
1772                             log_info("AG Rejected Incoming call, AG terminate call");
1773                             break;
1774                         default:
1775                             break;
1776                     }
1777                     break;
1778                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1779                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1780                     hfp_ag_set_callsetup_indicator();
1781                     hfp_ag_set_call_indicator();
1782                     hfp_ag_trigger_terminate_call();
1783                     log_info("AG terminate call");
1784                     break;
1785                 default:
1786                     break;
1787             }
1788             break;
1789         case HFP_AG_CALL_DROPPED:
1790             switch (hfp_gsm_call_status()){
1791                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1792                     switch (hfp_gsm_callsetup_status()){
1793                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1794                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1795                             hfp_ag_stop_ringing();
1796                             break;
1797                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1798                             log_info("Outgoing call interrupted\n");
1799                             break;
1800                         default:
1801                             break;
1802                     }
1803                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1804                     hfp_ag_set_callsetup_indicator();
1805                     hfp_ag_transfer_callsetup_state();
1806                     hfp_ag_trigger_terminate_call();
1807                     break;
1808                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1809                     if (hfp_ag_response_and_hold_active) {
1810                         hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1811                         hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1812                         hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1813                     }
1814                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1815                     hfp_ag_set_callsetup_indicator();
1816                     hfp_ag_set_call_indicator();
1817                     hfp_ag_trigger_terminate_call();
1818                     log_info("AG notify call dropped");
1819                     break;
1820                 default:
1821                     break;
1822             }
1823             break;
1824 
1825         case HFP_AG_OUTGOING_CALL_INITIATED_BY_HF:
1826             // directly reject call if number of free slots is exceeded
1827             if (!hfp_gsm_call_possible()){
1828                 hfp_connection->send_error = 1;
1829                 hfp_ag_run_for_context(hfp_connection);
1830                 break;
1831             }
1832 
1833             // note: number not used currently
1834             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, 0, 0, (const char *) &hfp_connection->line_buffer[3]);
1835 
1836             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1837 
1838             hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, (const char *) &hfp_connection->line_buffer[3]);
1839             break;
1840 
1841         case HFP_AG_OUTGOING_CALL_INITIATED_BY_AG:
1842             // directly reject call if number of free slots is exceeded
1843             if (!hfp_gsm_call_possible()) {
1844                 // TODO: no error for user
1845                 break;
1846             }
1847             switch (hfp_gsm_call_status()) {
1848                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1849                     switch (hfp_gsm_callsetup_status()) {
1850                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1851                             // note: number not used currently
1852                             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, 0, 0, "1234567");
1853                             // init call state for all connections
1854                             hfp_ag_trigger_outgoing_call();
1855                             // get first one and accept call
1856                             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1857                             if (hfp_connection) {
1858                                 hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1859                             }
1860                             break;
1861                         default:
1862                             // TODO: no error for user
1863                             break;
1864                     }
1865                     break;
1866                 default:
1867                     // TODO: no error for user
1868                     break;
1869             }
1870             break;
1871         case HFP_AG_OUTGOING_REDIAL_INITIATED:{
1872             // directly reject call if number of free slots is exceeded
1873             if (!hfp_gsm_call_possible()){
1874                 hfp_connection->send_error = 1;
1875                 hfp_ag_run_for_context(hfp_connection);
1876                 break;
1877             }
1878 
1879             hfp_gsm_handler(HFP_AG_OUTGOING_REDIAL_INITIATED, 0, 0, NULL);
1880             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1881 
1882             log_info("Redial last number");
1883             char * last_dialed_number = hfp_gsm_last_dialed_number();
1884 
1885             if (strlen(last_dialed_number) > 0){
1886                 log_info("Last number exists: accept call");
1887                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, last_dialed_number);
1888             } else {
1889                 log_info("log_infoLast number missing: reject call");
1890                 hfp_ag_handle_reject_outgoing_call();
1891             }
1892             break;
1893         }
1894         case HFP_AG_OUTGOING_CALL_REJECTED:
1895             hfp_ag_handle_reject_outgoing_call();
1896             break;
1897 
1898         case HFP_AG_OUTGOING_CALL_ACCEPTED:{
1899             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1900             if (!hfp_connection){
1901                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1902                 break;
1903             }
1904 
1905             hfp_connection->ok_pending = 1;
1906             hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1907             break;
1908         }
1909         case HFP_AG_OUTGOING_CALL_RINGING:
1910             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1911             if (!hfp_connection){
1912                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in dialing state");
1913                 break;
1914             }
1915 
1916             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_RINGING, 0, 0, NULL);
1917             hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1918             hfp_ag_set_callsetup_indicator();
1919             hfp_ag_transfer_callsetup_state();
1920             hfp_ag_hf_start_ringing_outgoing(hfp_connection);
1921             break;
1922 
1923         case HFP_AG_OUTGOING_CALL_ESTABLISHED:{
1924             // get outgoing call
1925             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_RINGING);
1926             if (!hfp_connection){
1927                 hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1928             }
1929             if (!hfp_connection){
1930                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection");
1931                 break;
1932             }
1933 
1934             bool callheld_status_call_on_hold_and_no_active_calls = hfp_gsm_callheld_status() == HFP_CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS;
1935             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ESTABLISHED, 0, 0, NULL);
1936             hfp_connection->call_state = HFP_CALL_ACTIVE;
1937             hfp_ag_set_callsetup_indicator();
1938             hfp_ag_set_call_indicator();
1939             hfp_ag_transfer_call_state();
1940             hfp_ag_transfer_callsetup_state();
1941             if (callheld_status_call_on_hold_and_no_active_calls){
1942                 hfp_ag_set_callheld_indicator();
1943                 hfp_ag_transfer_callheld_state();
1944             }
1945             hfp_ag_hf_stop_ringing(hfp_connection);
1946             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1947             break;
1948         }
1949 
1950         case HFP_AG_CALL_HOLD_USER_BUSY:
1951             hfp_gsm_handler(HFP_AG_CALL_HOLD_USER_BUSY, 0, 0, NULL);
1952             hfp_ag_set_callsetup_indicator();
1953             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1954             hfp_connection->call_state = HFP_CALL_ACTIVE;
1955             log_info("AG: Call Waiting, User Busy");
1956             break;
1957 
1958         case HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1959             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1960             int call_held = hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD;
1961 
1962             // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
1963             if (call_held || call_setup_in_progress){
1964                 hfp_gsm_handler(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index,
1965                                 0, NULL);
1966 
1967             }
1968 
1969             if (call_setup_in_progress){
1970                 log_info("AG: Call Dropped, Accept new call");
1971                 hfp_ag_set_callsetup_indicator();
1972                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1973             } else {
1974                 log_info("AG: Call Dropped, Resume held call");
1975             }
1976             if (call_held){
1977                 hfp_ag_set_callheld_indicator();
1978                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1979             }
1980 
1981             hfp_connection->call_state = HFP_CALL_ACTIVE;
1982             break;
1983         }
1984 
1985         case HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1986             // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
1987             // only update if callsetup changed
1988             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1989             hfp_gsm_handler(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index, 0,
1990                             NULL);
1991 
1992             if (call_setup_in_progress){
1993                 log_info("AG: Call on Hold, Accept new call");
1994                 hfp_ag_set_callsetup_indicator();
1995                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1996             } else {
1997                 log_info("AG: Swap calls");
1998             }
1999 
2000             hfp_ag_set_callheld_indicator();
2001             // hfp_ag_set_callheld_state(HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED);
2002             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
2003             hfp_connection->call_state = HFP_CALL_ACTIVE;
2004             break;
2005         }
2006 
2007         case HFP_AG_CALL_HOLD_ADD_HELD_CALL:
2008             // Adds a held call to the conversation.
2009             if (hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD){
2010                 log_info("AG: Join 3-way-call");
2011                 hfp_gsm_handler(HFP_AG_CALL_HOLD_ADD_HELD_CALL, 0, 0, NULL);
2012                 hfp_ag_set_callheld_indicator();
2013                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
2014                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
2015             }
2016             hfp_connection->call_state = HFP_CALL_ACTIVE;
2017             break;
2018         case HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS:
2019             // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer)
2020             hfp_gsm_handler(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, 0, 0, NULL);
2021             log_info("AG: Transfer call -> Connect two calls and disconnect");
2022             hfp_ag_set_call_indicator();
2023             hfp_ag_set_callheld_indicator();
2024             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
2025             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
2026             hfp_connection->call_state = HFP_CALL_IDLE;
2027             break;
2028 
2029         default:
2030             break;
2031     }
2032 
2033 
2034 }
2035 
2036 
2037 static void hfp_ag_send_call_status(hfp_connection_t * hfp_connection, int call_index){
2038     hfp_gsm_call_t * active_call = hfp_gsm_call(call_index);
2039     if (!active_call) return;
2040 
2041     int idx = active_call->index;
2042     hfp_enhanced_call_dir_t dir = active_call->direction;
2043     hfp_enhanced_call_status_t status = active_call->enhanced_status;
2044     hfp_enhanced_call_mode_t mode = active_call->mode;
2045     hfp_enhanced_call_mpty_t mpty = active_call->mpty;
2046     uint8_t type = active_call->clip_type;
2047     char * number = active_call->clip_number;
2048 
2049     char buffer[100];
2050     // TODO: check length of a buffer, to fit the MTU
2051     int offset = snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d,%d,%d,%d", HFP_LIST_CURRENT_CALLS, idx, dir, status, mode, mpty);
2052     if (number){
2053         offset += snprintf(buffer+offset, sizeof(buffer)-offset-3, ", \"%s\",%u", number, type);
2054     }
2055     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n");
2056     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,
2057        mode, mpty, type, number);
2058     send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
2059 }
2060 
2061 // sends pending command, returns if command was sent
2062 static int hfp_ag_send_commands(hfp_connection_t *hfp_connection){
2063     if (hfp_connection->send_status_of_current_calls){
2064         hfp_connection->ok_pending = 0;
2065         if (hfp_connection->next_call_index < hfp_gsm_get_number_of_calls()){
2066             hfp_connection->next_call_index++;
2067             hfp_ag_send_call_status(hfp_connection, hfp_connection->next_call_index);
2068             return 1;
2069         } else {
2070             // 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
2071             hfp_connection->next_call_index = 0;
2072             hfp_connection->ok_pending = 1;
2073             hfp_connection->send_status_of_current_calls = 0;
2074         }
2075     }
2076 
2077     if (hfp_connection->ag_notify_incoming_call_waiting){
2078         hfp_connection->ag_notify_incoming_call_waiting = 0;
2079         hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
2080         return 1;
2081     }
2082 
2083     if (hfp_connection->send_error){
2084         hfp_connection->send_error = 0;
2085         hfp_connection->command = HFP_CMD_NONE;
2086         hfp_ag_send_error(hfp_connection->rfcomm_cid);
2087         return 1;
2088     }
2089 
2090     // note: before update AG indicators and ok_pending
2091     if (hfp_connection->send_response_and_hold_status){
2092         int status = hfp_connection->send_response_and_hold_status - 1;
2093         hfp_connection->send_response_and_hold_status = 0;
2094         hfp_ag_send_set_response_and_hold(hfp_connection->rfcomm_cid, status);
2095         return 1;
2096     }
2097 
2098     // note: before ok_pending and send_error to allow for unsolicited result on custom command
2099     if (hfp_connection->send_custom_message != NULL){
2100         const char * message = hfp_connection->send_custom_message;
2101         hfp_connection->send_custom_message = NULL;
2102         send_str_over_rfcomm(hfp_connection->rfcomm_cid, message);
2103         hfp_emit_event(hfp_connection, HFP_SUBEVENT_COMPLETE, ERROR_CODE_SUCCESS);
2104         return 1;
2105     }
2106 
2107     if (hfp_connection->ok_pending){
2108         hfp_connection->ok_pending = 0;
2109         hfp_connection->command = HFP_CMD_NONE;
2110         hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2111         return 1;
2112     }
2113 
2114     // update AG indicators only if enabled by AT+CMER=3,0,0,1
2115     if ((hfp_connection->enable_status_update_for_ag_indicators == 1) && (hfp_connection->ag_indicators_status_update_bitmap != 0)){
2116         uint16_t i;
2117         for (i=0;i<hfp_connection->ag_indicators_nr;i++){
2118             if (get_bit(hfp_connection->ag_indicators_status_update_bitmap, i)){
2119                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, i, 0);
2120                 hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[i]);
2121                 return 1;
2122             }
2123         }
2124     }
2125 
2126     if (hfp_connection->ag_send_no_carrier){
2127         hfp_connection->ag_send_no_carrier = false;
2128         hfp_ag_send_no_carrier(hfp_connection->rfcomm_cid);
2129         return 1;
2130     }
2131 
2132     if (hfp_connection->send_phone_number_for_voice_tag){
2133         hfp_connection->send_phone_number_for_voice_tag = 0;
2134         hfp_connection->command = HFP_CMD_NONE;
2135         hfp_connection->ok_pending = 1;
2136         hfp_ag_send_phone_number_for_voice_tag_cmd(hfp_connection->rfcomm_cid);
2137         return 1;
2138     }
2139 
2140     if (hfp_connection->send_subscriber_number){
2141         if (hfp_connection->next_subscriber_number_to_send < hfp_ag_subscriber_numbers_count){
2142             hfp_phone_number_t phone = hfp_ag_subscriber_numbers[hfp_connection->next_subscriber_number_to_send++];
2143             hfp_send_subscriber_number_cmd(hfp_connection->rfcomm_cid, phone.type, phone.number);
2144         } else {
2145             hfp_connection->send_subscriber_number = 0;
2146             hfp_connection->next_subscriber_number_to_send = 0;
2147             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2148         }
2149         hfp_connection->command = HFP_CMD_NONE;
2150         return 1;
2151     }
2152 
2153     if (hfp_connection->send_microphone_gain){
2154         hfp_connection->send_microphone_gain = 0;
2155         hfp_connection->command = HFP_CMD_NONE;
2156         hfp_ag_send_set_microphone_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->microphone_gain);
2157         return 1;
2158     }
2159 
2160     if (hfp_connection->send_speaker_gain){
2161         hfp_connection->send_speaker_gain = 0;
2162         hfp_connection->command = HFP_CMD_NONE;
2163         hfp_ag_send_set_speaker_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->speaker_gain);
2164         return 1;
2165     }
2166 
2167     if (hfp_connection->send_ag_status_indicators){
2168         hfp_connection->send_ag_status_indicators = 0;
2169         hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
2170         return 1;
2171     }
2172 
2173     return 0;
2174 }
2175 
2176 // sends pending command, returns if command was sent
2177 static int hfp_ag_run_ring_and_clip(hfp_connection_t *hfp_connection){
2178     // delay RING/CLIP until audio connection has been established for incoming calls
2179     // hfp_ag_hf_trigger_ring_and_clip is called in call_setup_state_machine
2180     if (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING){
2181         if (hfp_connection->ag_ring){
2182             hfp_connection->ag_ring = 0;
2183             hfp_connection->command = HFP_CMD_NONE;
2184             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_RING);
2185             hfp_ag_send_ring(hfp_connection->rfcomm_cid);
2186             return 1;
2187         }
2188 
2189         if (hfp_connection->ag_send_clip){
2190             hfp_connection->ag_send_clip = 0;
2191             hfp_connection->command = HFP_CMD_NONE;
2192             hfp_ag_send_clip(hfp_connection->rfcomm_cid);
2193             return 1;
2194         }
2195     }
2196     return 0;
2197 }
2198 
2199 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection){
2200 
2201 	btstack_assert(hfp_connection != NULL);
2202 	btstack_assert(hfp_connection->local_role == HFP_ROLE_AG);
2203 
2204 	// during SDP query, RFCOMM CID is not set
2205 	if (hfp_connection->rfcomm_cid == 0) return;
2206 
2207     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED && hfp_connection->emit_vra_enabled_after_audio_established){
2208         hfp_connection->emit_vra_enabled_after_audio_established = false;
2209         hfp_emit_voice_recognition_enabled(hfp_connection, ERROR_CODE_SUCCESS);
2210     }
2211 
2212     if ((hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) && hfp_connection->release_audio_connection){
2213         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
2214         hfp_connection->release_audio_connection = 0;
2215         gap_disconnect(hfp_connection->sco_handle);
2216         return;
2217     }
2218 
2219     // configure NBS/WBS if needed using vendor-specific HCI commands
2220     if (hci_can_send_command_packet_now()) {
2221 #ifdef ENABLE_CC256X_ASSISTED_HFP
2222         // WBS Disassociate
2223         if (hfp_connection->cc256x_send_wbs_disassociate){
2224             hfp_connection->cc256x_send_wbs_disassociate = false;
2225             hci_send_cmd(&hci_ti_wbs_disassociate);
2226             return;
2227         }
2228         // Write Codec Config
2229         if (hfp_connection->cc256x_send_write_codec_config){
2230             hfp_connection->cc256x_send_write_codec_config = false;
2231             hfp_cc256x_write_codec_config(hfp_connection);
2232             return;
2233         }
2234         // WBS Associate
2235         if (hfp_connection->cc256x_send_wbs_associate){
2236             hfp_connection->cc256x_send_wbs_associate = false;
2237             hci_send_cmd(&hci_ti_wbs_associate, hfp_connection->acl_handle);
2238             return;
2239         }
2240 #endif
2241 #ifdef ENABLE_BCM_PCM_WBS
2242         // Enable WBS
2243         if (hfp_connection->bcm_send_enable_wbs){
2244             hfp_connection->bcm_send_enable_wbs = false;
2245             hci_send_cmd(&hci_bcm_enable_wbs, 1, 2);
2246             return;
2247         }
2248         // Write I2S/PCM params
2249         if (hfp_connection->bcm_send_write_i2spcm_interface_param){
2250             hfp_connection->bcm_send_write_i2spcm_interface_param = false;
2251             hfp_bcm_write_i2spcm_interface_param(hfp_connection);
2252             return;
2253         }
2254         // Disable WBS
2255         if (hfp_connection->bcm_send_disable_wbs){
2256             hfp_connection->bcm_send_disable_wbs = false;
2257             hci_send_cmd(&hci_bcm_enable_wbs, 0, 2);
2258             return;
2259         }
2260 #endif
2261 #ifdef ENABLE_RTK_PCM_WBS
2262         // Configure CVSD vs. mSBC
2263         if (hfp_connection->rtk_send_sco_config){
2264             hfp_connection->rtk_send_sco_config = false;
2265             if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
2266                 log_info("RTK SCO: 16k + mSBC");
2267                 hci_send_cmd(&hci_rtk_configure_sco_routing, 0x81, 0x90, 0x00, 0x00, 0x1a, 0x0c, 0x00, 0x00, 0x41);
2268             } else {
2269                 log_info("RTK SCO: 16k + CVSD");
2270                 hci_send_cmd(&hci_rtk_configure_sco_routing, 0x81, 0x90, 0x00, 0x00, 0x1a, 0x0c, 0x0c, 0x00, 0x01);
2271             }
2272             return;
2273         }
2274 #endif
2275     }
2276 
2277 #if defined (ENABLE_CC256X_ASSISTED_HFP) || defined (ENABLE_BCM_PCM_WBS)
2278     if (hfp_connection->state == HFP_W4_WBS_SHUTDOWN){
2279         hfp_finalize_connection_context(hfp_connection);
2280         return;
2281     }
2282 #endif
2283 
2284     if (!rfcomm_can_send_packet_now(hfp_connection->rfcomm_cid)) {
2285         log_info("hfp_ag_run_for_context: request can send for 0x%02x", hfp_connection->rfcomm_cid);
2286         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2287         return;
2288     }
2289 
2290     int cmd_sent = hfp_ag_send_commands(hfp_connection);
2291 
2292     if (!cmd_sent){
2293         cmd_sent = hfp_ag_run_for_context_service_level_connection(hfp_connection);
2294     }
2295 
2296     if (!cmd_sent){
2297         cmd_sent = hfp_ag_run_for_context_service_level_connection_queries(hfp_connection);
2298     }
2299 
2300     if (!cmd_sent){
2301         cmd_sent = call_setup_state_machine(hfp_connection);
2302     }
2303 
2304     if (!cmd_sent){
2305         cmd_sent = hfp_ag_run_for_audio_connection(hfp_connection);
2306     }
2307 
2308     if (!cmd_sent){
2309         cmd_sent = hfp_ag_run_ring_and_clip(hfp_connection);
2310     }
2311 
2312     if (!cmd_sent){
2313         cmd_sent = hfp_ag_voice_recognition_state_machine(hfp_connection);
2314     }
2315 
2316     // disconnect
2317     if (!cmd_sent && (hfp_connection->command == HFP_CMD_NONE) && (hfp_connection->state == HFP_W2_DISCONNECT_RFCOMM)){
2318         hfp_connection->state = HFP_W4_RFCOMM_DISCONNECTED;
2319         rfcomm_disconnect(hfp_connection->rfcomm_cid);
2320     }
2321 
2322     if (cmd_sent){
2323         hfp_connection->command = HFP_CMD_NONE;
2324         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2325     }
2326 }
2327 
2328 static int hfp_parser_is_end_of_line(uint8_t byte){
2329     return (byte == '\n') || (byte == '\r');
2330 }
2331 
2332 static void hfp_ag_handle_rfcomm_data(hfp_connection_t * hfp_connection, uint8_t *packet, uint16_t size){
2333     // assertion: size >= 1 as rfcomm.c does not deliver empty packets
2334     if (size < 1) return;
2335     uint8_t status = ERROR_CODE_SUCCESS;
2336 
2337     hfp_log_rfcomm_message("HFP_AG_RX", packet, size);
2338 #ifdef ENABLE_HFP_AT_MESSAGES
2339     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_RECEIVED, (char *) packet);
2340 #endif
2341 
2342     // process messages byte-wise
2343     int pos;
2344     for (pos = 0; pos < size ; pos++){
2345         hfp_parse(hfp_connection, packet[pos], 0);
2346 
2347         // parse until end of line
2348         if (!hfp_parser_is_end_of_line(packet[pos])) continue;
2349 
2350         hfp_generic_status_indicator_t * indicator;
2351         switch(hfp_connection->command){
2352             case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
2353                 hfp_connection->command = HFP_CMD_NONE;
2354                 hfp_connection->ag_vra_requested_by_hf = true;
2355                 break;
2356             case HFP_CMD_RESPONSE_AND_HOLD_QUERY:
2357                 hfp_connection->command = HFP_CMD_NONE;
2358                 if (hfp_ag_response_and_hold_active){
2359                     hfp_connection->send_response_and_hold_status = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD + 1;
2360                 }
2361                 hfp_connection->ok_pending = 1;
2362                 break;
2363             case HFP_CMD_RESPONSE_AND_HOLD_COMMAND:
2364                 hfp_connection->command = HFP_CMD_NONE;
2365                 switch(hfp_connection->ag_response_and_hold_action){
2366                     case HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD:
2367                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, hfp_connection);
2368                         break;
2369                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED:
2370                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF, hfp_connection);
2371                         break;
2372                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED:
2373                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF, hfp_connection);
2374                         break;
2375                     default:
2376                         break;
2377                 }
2378                 hfp_connection->ok_pending = 1;
2379                 break;
2380             case HFP_CMD_HF_INDICATOR_STATUS:
2381                 hfp_connection->command = HFP_CMD_NONE;
2382 
2383                 if (hfp_connection->parser_indicator_index < hfp_ag_generic_status_indicators_nr){
2384                     indicator = &hfp_ag_generic_status_indicators[hfp_connection->parser_indicator_index];
2385                     switch (indicator->uuid){
2386                         case HFP_HF_INDICATOR_UUID_ENHANCED_SAFETY:
2387                             if (hfp_connection->parser_indicator_value > 1) {
2388                                 hfp_connection->send_error = 1;
2389                                 break;
2390                             }
2391                             hfp_connection->ok_pending = 1;
2392                             hfp_ag_emit_hf_indicator_value(hfp_connection, indicator->uuid, hfp_connection->parser_indicator_value);
2393                             break;
2394                         case HFP_HF_INDICATOR_UUID_BATTERY_LEVEL:
2395                             if (hfp_connection->parser_indicator_value > 100){
2396                                 hfp_connection->send_error = 1;
2397                                 break;
2398                             }
2399                             hfp_connection->ok_pending = 1;
2400                             hfp_ag_emit_hf_indicator_value(hfp_connection, indicator->uuid, hfp_connection->parser_indicator_value);
2401                             break;
2402                         default:
2403                             hfp_connection->send_error = 1;
2404                             break;
2405                     }
2406                 } else {
2407                     hfp_connection->send_error = 1;
2408                 }
2409                 break;
2410             case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
2411                 // expected by SLC state machine
2412                 if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) break;
2413                 hfp_connection->send_ag_indicators_segment = 0;
2414                 hfp_connection->send_ag_status_indicators = 1;
2415                 break;
2416             case HFP_CMD_LIST_CURRENT_CALLS:
2417                 hfp_connection->command = HFP_CMD_NONE;
2418                 hfp_connection->next_call_index = 0;
2419                 hfp_connection->send_status_of_current_calls = 1;
2420                 break;
2421             case HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION:
2422                 hfp_connection->command = HFP_CMD_NONE;
2423                 if (hfp_ag_subscriber_numbers_count == 0){
2424                     hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2425                     break;
2426                 }
2427                 hfp_connection->next_subscriber_number_to_send = 0;
2428                 hfp_connection->send_subscriber_number = 1;
2429                 break;
2430             case HFP_CMD_TRANSMIT_DTMF_CODES:
2431             {
2432                 hfp_connection->command = HFP_CMD_NONE;
2433                 char buffer[2];
2434                 buffer[0] = (char) hfp_connection->ag_dtmf_code;
2435                 buffer[1] = 0;
2436                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_TRANSMIT_DTMF_CODES, buffer);
2437                 break;
2438             }
2439             case HFP_CMD_HF_REQUEST_PHONE_NUMBER:
2440                 hfp_connection->command = HFP_CMD_NONE;
2441                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_ATTACH_NUMBER_TO_VOICE_TAG);
2442                 break;
2443             case HFP_CMD_TURN_OFF_EC_AND_NR:
2444                 hfp_connection->command = HFP_CMD_NONE;
2445 
2446                 if (get_bit(hfp_ag_supported_features, HFP_AGSF_EC_NR_FUNCTION)){
2447                     hfp_connection->ok_pending = 1;
2448                     hfp_ag_supported_features = store_bit(hfp_ag_supported_features, HFP_AGSF_EC_NR_FUNCTION, hfp_connection->ag_echo_and_noise_reduction);
2449                     status = ERROR_CODE_SUCCESS;
2450                 } else {
2451                     hfp_connection->send_error = 1;
2452                     status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2453                 }
2454                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_ECHO_CANCELING_AND_NOISE_REDUCTION_DEACTIVATE, status);
2455                 break;
2456             case HFP_CMD_CALL_ANSWERED:
2457                 hfp_connection->command = HFP_CMD_NONE;
2458                 log_info("HFP: ATA");
2459                 hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, hfp_connection);
2460                 break;
2461             case HFP_CMD_HANG_UP_CALL:
2462                 hfp_connection->command = HFP_CMD_NONE;
2463                 hfp_connection->ok_pending = 1;
2464                 hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_HF, hfp_connection);
2465                 break;
2466             case HFP_CMD_CALL_HOLD: {
2467                 hfp_connection->command = HFP_CMD_NONE;
2468                 hfp_connection->ok_pending = 1;
2469 
2470                 switch (hfp_connection->ag_call_hold_action){
2471                     case 0:
2472                         // Releases all held calls or sets User Determined User Busy (UDUB) for a waiting call.
2473                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_USER_BUSY, hfp_connection);
2474                         break;
2475                     case 1:
2476                         // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
2477                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2478                         // waiting call (i.e., not to the held call) in conflicting situation.
2479                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2480                         break;
2481                     case 2:
2482                         // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
2483                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2484                         // waiting call (i.e., not to the held call) in conflicting situation.
2485                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2486                         break;
2487                     case 3:
2488                         // Adds a held call to the conversation.
2489                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_ADD_HELD_CALL, hfp_connection);
2490                         break;
2491                     case 4:
2492                         // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer).
2493                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, hfp_connection);
2494                         break;
2495                     default:
2496                         break;
2497                 }
2498 				hfp_connection->call_index = 0;
2499                 break;
2500             }
2501             case HFP_CMD_CALL_PHONE_NUMBER:
2502                 hfp_connection->command = HFP_CMD_NONE;
2503                 hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, hfp_connection);
2504                 break;
2505             case HFP_CMD_REDIAL_LAST_NUMBER:
2506                 hfp_connection->command = HFP_CMD_NONE;
2507                 hfp_ag_call_sm(HFP_AG_OUTGOING_REDIAL_INITIATED, hfp_connection);
2508                 break;
2509             case HFP_CMD_ENABLE_CLIP:
2510                 hfp_connection->command = HFP_CMD_NONE;
2511                 log_info("hfp: clip set, now: %u", hfp_connection->clip_enabled);
2512                 hfp_connection->ok_pending = 1;
2513                 break;
2514             case HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION:
2515                 hfp_connection->command = HFP_CMD_NONE;
2516                 log_info("hfp: call waiting notification set, now: %u", hfp_connection->call_waiting_notification_enabled);
2517                 hfp_connection->ok_pending = 1;
2518                 break;
2519             case HFP_CMD_SET_SPEAKER_GAIN:
2520                 hfp_connection->command = HFP_CMD_NONE;
2521                 hfp_connection->ok_pending = 1;
2522                 log_info("HF speaker gain = %u", hfp_connection->speaker_gain);
2523                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_SPEAKER_VOLUME, hfp_connection->speaker_gain);
2524                 break;
2525             case HFP_CMD_SET_MICROPHONE_GAIN:
2526                 hfp_connection->command = HFP_CMD_NONE;
2527                 hfp_connection->ok_pending = 1;
2528                 log_info("HF microphone gain = %u", hfp_connection->microphone_gain);
2529                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_MICROPHONE_VOLUME, hfp_connection->microphone_gain);
2530                 break;
2531             case HFP_CMD_CUSTOM_MESSAGE:
2532                 hfp_connection->command = HFP_CMD_NONE;
2533                 hfp_parser_reset_line_buffer(hfp_connection);
2534                 log_info("Custom AT Command ID 0x%04x", hfp_connection->ag_custom_at_command_id);
2535                 hfp_ag_emit_custom_command_event(hfp_connection);
2536                 break;
2537             case HFP_CMD_UNKNOWN:
2538                 hfp_connection->command = HFP_CMD_NONE;
2539                 hfp_connection->send_error = 1;
2540                 break;
2541             default:
2542                 break;
2543         }
2544     }
2545 }
2546 
2547 static void hfp_ag_run(void){
2548     btstack_linked_list_iterator_t it;
2549     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2550     while (btstack_linked_list_iterator_has_next(&it)){
2551         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2552         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2553         hfp_ag_run_for_context(hfp_connection);
2554     }
2555 }
2556 
2557 static void hfp_ag_rfcomm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2558     hfp_connection_t * hfp_connection = NULL;
2559     switch (packet_type){
2560         case RFCOMM_DATA_PACKET:
2561             hfp_connection = get_hfp_connection_context_for_rfcomm_cid(channel);
2562             btstack_assert(hfp_connection != NULL);
2563 
2564             hfp_ag_handle_rfcomm_data(hfp_connection, packet, size);
2565             hfp_ag_run_for_context(hfp_connection);
2566             return;
2567         case HCI_EVENT_PACKET:
2568             if (packet[0] == RFCOMM_EVENT_CAN_SEND_NOW){
2569                 uint16_t rfcomm_cid = rfcomm_event_can_send_now_get_rfcomm_cid(packet);
2570                 hfp_connection = get_hfp_connection_context_for_rfcomm_cid(rfcomm_cid);
2571                 btstack_assert(hfp_connection != NULL);
2572 
2573                 hfp_ag_run_for_context(hfp_connection);
2574                 return;
2575             }
2576             hfp_handle_rfcomm_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2577             break;
2578         default:
2579             break;
2580     }
2581 
2582     hfp_ag_run();
2583 }
2584 
2585 static void hfp_ag_hci_event_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2586     hfp_handle_hci_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2587     hfp_ag_run();
2588 }
2589 
2590 void hfp_ag_init_codecs(int codecs_nr, const uint8_t * codecs){
2591     if (codecs_nr > HFP_MAX_NUM_CODECS){
2592         log_error("hfp_init: codecs_nr (%d) > HFP_MAX_NUM_CODECS (%d)", codecs_nr, HFP_MAX_NUM_CODECS);
2593         return;
2594     }
2595     int i;
2596     hfp_ag_codecs_nr = codecs_nr;
2597     for (i=0; i < codecs_nr; i++){
2598         hfp_ag_codecs[i] = codecs[i];
2599     }
2600 }
2601 
2602 void hfp_ag_init_supported_features(uint32_t supported_features){
2603     hfp_ag_supported_features = supported_features;
2604 }
2605 
2606 void hfp_ag_init_ag_indicators(int ag_indicators_nr, const hfp_ag_indicator_t * ag_indicators){
2607     hfp_ag_indicators_nr = ag_indicators_nr;
2608     (void)memcpy(hfp_ag_indicators, ag_indicators,
2609                  ag_indicators_nr * sizeof(hfp_ag_indicator_t));
2610 }
2611 
2612 void hfp_ag_init_hf_indicators(int hf_indicators_nr, const hfp_generic_status_indicator_t * hf_indicators){
2613     if (hf_indicators_nr > HFP_MAX_NUM_INDICATORS) return;
2614     hfp_ag_generic_status_indicators_nr = hf_indicators_nr;
2615     (void)memcpy(hfp_ag_generic_status_indicators, hf_indicators,
2616                  hf_indicators_nr * sizeof(hfp_generic_status_indicator_t));
2617 }
2618 
2619 void hfp_ag_init_call_hold_services(int call_hold_services_nr, const char * call_hold_services[]){
2620     hfp_ag_call_hold_services_nr = call_hold_services_nr;
2621     (void)memcpy(hfp_ag_call_hold_services, call_hold_services,
2622                  call_hold_services_nr * sizeof(char *));
2623 }
2624 
2625 
2626 void hfp_ag_init(uint8_t rfcomm_channel_nr){
2627 
2628     hfp_init();
2629     hfp_ag_call_hold_services_nr = 0;
2630     hfp_ag_response_and_hold_active = false;
2631     hfp_ag_indicators_nr = 0;
2632     hfp_ag_codecs_nr = 0;
2633     hfp_ag_supported_features = HFP_DEFAULT_AG_SUPPORTED_FEATURES;
2634     hfp_ag_subscriber_numbers = NULL;
2635     hfp_ag_subscriber_numbers_count = 0;
2636 
2637     hfp_ag_hci_event_callback_registration.callback = &hfp_ag_hci_event_packet_handler;
2638     hci_add_event_handler(&hfp_ag_hci_event_callback_registration);
2639 
2640     rfcomm_register_service(&hfp_ag_rfcomm_packet_handler, rfcomm_channel_nr, 0xffff);
2641 
2642     // used to set packet handler for outgoing rfcomm connections - could be handled by emitting an event to us
2643     hfp_set_ag_rfcomm_packet_handler(&hfp_ag_rfcomm_packet_handler);
2644 
2645     hfp_gsm_init();
2646 }
2647 
2648 void hfp_ag_deinit(void){
2649     hfp_deinit();
2650     hfp_gsm_deinit();
2651 
2652     hfp_ag_callback = NULL;
2653     hfp_ag_supported_features = 0;
2654     hfp_ag_codecs_nr = 0;
2655     hfp_ag_indicators_nr = 0;
2656     hfp_ag_call_hold_services_nr = 0;
2657     (void) memset(&hfp_ag_call_hold_services, 0, sizeof(hfp_ag_call_hold_services));
2658     hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
2659     (void) memset(&hfp_ag_response_and_hold_state, 0, sizeof(hfp_response_and_hold_state_t));
2660     hfp_ag_subscriber_numbers = NULL;
2661     (void) memset(&hfp_ag_hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
2662     hfp_ag_custom_call_sm_handler = NULL;
2663 }
2664 
2665 uint8_t hfp_ag_establish_service_level_connection(bd_addr_t bd_addr){
2666     return hfp_establish_service_level_connection(bd_addr, BLUETOOTH_SERVICE_CLASS_HANDSFREE, HFP_ROLE_AG);
2667 }
2668 
2669 uint8_t hfp_ag_release_service_level_connection(hci_con_handle_t acl_handle){
2670     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2671     if (!hfp_connection){
2672         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2673     }
2674 
2675     hfp_trigger_release_service_level_connection(hfp_connection);
2676     hfp_ag_run_for_context(hfp_connection);
2677     return ERROR_CODE_SUCCESS;
2678 }
2679 
2680 uint8_t hfp_ag_report_extended_audio_gateway_error_result_code(hci_con_handle_t acl_handle, hfp_cme_error_t error){
2681     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2682     if (!hfp_connection){
2683         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2684     }
2685 
2686     hfp_connection->extended_audio_gateway_error = 0;
2687     if (!hfp_connection->enable_extended_audio_gateway_error_report){
2688         return ERROR_CODE_COMMAND_DISALLOWED;
2689     }
2690 
2691     hfp_connection->extended_audio_gateway_error = error;
2692     hfp_ag_run_for_context(hfp_connection);
2693     return ERROR_CODE_SUCCESS;
2694 }
2695 
2696 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection){
2697     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
2698         return ERROR_CODE_COMMAND_DISALLOWED;
2699     }
2700     if (hfp_connection->state >= HFP_W2_DISCONNECT_SCO){
2701         return ERROR_CODE_COMMAND_DISALLOWED;
2702     }
2703 
2704     hfp_connection->establish_audio_connection = 1;
2705     if (!has_codec_negotiation_feature(hfp_connection)){
2706         log_info("hfp_ag_establish_audio_connection - no codec negotiation feature, using CVSD");
2707         hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
2708         hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
2709         // now, pick link settings
2710         hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
2711 #ifdef ENABLE_CC256X_ASSISTED_HFP
2712         hfp_cc256x_prepare_for_sco(hfp_connection);
2713 #endif
2714         return ERROR_CODE_SUCCESS;
2715     }
2716 
2717     uint8_t i;
2718     bool codec_was_in_use = false;
2719     bool better_codec_can_be_used = false;
2720 
2721     for (i = 0; i<hfp_connection->remote_codecs_nr; i++){
2722         if (hfp_connection->negotiated_codec == hfp_connection->remote_codecs[i]){
2723             codec_was_in_use = true;
2724         } else if (hfp_connection->negotiated_codec < hfp_connection->remote_codecs[i]){
2725             better_codec_can_be_used = true;
2726         }
2727     }
2728 
2729     if (!codec_was_in_use || better_codec_can_be_used){
2730         hfp_connection->ag_send_common_codec = true;
2731         hfp_connection->codecs_state = HFP_CODECS_IDLE;
2732     }
2733     return ERROR_CODE_SUCCESS;
2734 }
2735 
2736 uint8_t hfp_ag_establish_audio_connection(hci_con_handle_t acl_handle){
2737     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2738     if (!hfp_connection){
2739         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2740     }
2741     uint8_t status = hfp_ag_setup_audio_connection(hfp_connection);
2742     if (status != ERROR_CODE_SUCCESS){
2743         return status;
2744     }
2745     hfp_ag_run_for_context(hfp_connection);
2746     return ERROR_CODE_SUCCESS;
2747 }
2748 
2749 uint8_t hfp_ag_release_audio_connection(hci_con_handle_t acl_handle){
2750     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2751     if (!hfp_connection){
2752         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2753     }
2754 
2755     if (hfp_connection->vra_state == HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
2756         return ERROR_CODE_COMMAND_DISALLOWED;
2757     }
2758 
2759     uint8_t status = hfp_trigger_release_audio_connection(hfp_connection);
2760     if (status == ERROR_CODE_SUCCESS){
2761         hfp_ag_run_for_context(hfp_connection);
2762     }
2763     return status;
2764 }
2765 
2766 /**
2767  * @brief Enable in-band ring tone
2768  */
2769 void hfp_ag_set_use_in_band_ring_tone(int use_in_band_ring_tone){
2770     if (get_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE) == use_in_band_ring_tone){
2771         return;
2772     }
2773 
2774     hfp_ag_supported_features = store_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE, use_in_band_ring_tone);
2775 
2776     btstack_linked_list_iterator_t it;
2777     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2778     while (btstack_linked_list_iterator_has_next(&it)){
2779         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2780         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2781         hfp_connection->ag_send_in_band_ring_tone_setting = true;
2782         hfp_ag_run_for_context(hfp_connection);
2783     }
2784 }
2785 
2786 /**
2787  * @brief Called from GSM
2788  */
2789 void hfp_ag_incoming_call(void){
2790     hfp_ag_call_sm(HFP_AG_INCOMING_CALL, NULL);
2791 }
2792 
2793 void hfp_ag_outgoing_call_initiated(void) {
2794     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, NULL);
2795 }
2796 
2797 /**
2798  * @brief number is stored.
2799  */
2800 void hfp_ag_set_clip(uint8_t type, const char * number){
2801     hfp_gsm_handler(HFP_AG_SET_CLIP, 0, type, number);
2802 }
2803 
2804 void hfp_ag_call_dropped(void){
2805     hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2806 }
2807 
2808 // call from AG UI
2809 void hfp_ag_answer_incoming_call(void){
2810     hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, NULL);
2811 }
2812 
2813 void hfp_ag_join_held_call(void){
2814     hfp_ag_call_sm(HFP_AG_HELD_CALL_JOINED_BY_AG, NULL);
2815 }
2816 
2817 void hfp_ag_terminate_call(void){
2818     hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_AG, NULL);
2819 }
2820 
2821 void hfp_ag_outgoing_call_ringing(void){
2822     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_RINGING, NULL);
2823 }
2824 
2825 void hfp_ag_outgoing_call_established(void){
2826     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ESTABLISHED, NULL);
2827 }
2828 
2829 void hfp_ag_outgoing_call_rejected(void){
2830     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_REJECTED, NULL);
2831 }
2832 
2833 void hfp_ag_outgoing_call_accepted(void){
2834     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ACCEPTED, NULL);
2835 }
2836 
2837 void hfp_ag_hold_incoming_call(void){
2838     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, NULL);
2839 }
2840 
2841 void hfp_ag_accept_held_incoming_call(void) {
2842     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, NULL);
2843 }
2844 
2845 void hfp_ag_reject_held_incoming_call(void){
2846     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, NULL);
2847 }
2848 
2849 static void hfp_ag_set_ag_indicator(const char * name, int value){
2850     int indicator_index = get_ag_indicator_index_for_name(name);
2851     if (indicator_index < 0) return;
2852     hfp_ag_indicators[indicator_index].status = value;
2853 
2854     btstack_linked_list_iterator_t it;
2855     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2856     while (btstack_linked_list_iterator_has_next(&it)){
2857         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2858         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2859         if (!hfp_connection->ag_indicators[indicator_index].enabled) {
2860             log_info("Requested AG indicator '%s' update to %u, but it is not enabled", hfp_ag_indicators[indicator_index].name, value);
2861             continue;
2862         }
2863         log_info("AG indicator '%s' changed to %u, request transfer status", hfp_ag_indicators[indicator_index].name, value);
2864         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
2865         hfp_ag_run_for_context(hfp_connection);
2866     }
2867 }
2868 
2869 uint8_t hfp_ag_set_registration_status(int registration_status){
2870     if ((registration_status < 0) || (registration_status > 1)){
2871         return ERROR_CODE_COMMAND_DISALLOWED;
2872     }
2873 
2874     if ( (registration_status == 0) && (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT)){
2875 
2876         // if network goes away wihle a call is active:
2877         // - the  call gets dropped
2878         // - we send NO CARRIER
2879         // NOTE: the CALL=0 has to be sent before NO CARRIER
2880 
2881         hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2882 
2883         btstack_linked_list_iterator_t it;
2884         btstack_linked_list_iterator_init(&it, hfp_get_connections());
2885         while (btstack_linked_list_iterator_has_next(&it)){
2886             hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2887             hfp_connection->ag_send_no_carrier = true;
2888         }
2889     }
2890     hfp_ag_set_ag_indicator("service", registration_status);
2891     return ERROR_CODE_SUCCESS;
2892 }
2893 
2894 uint8_t hfp_ag_set_signal_strength(int signal_strength){
2895     if ((signal_strength < 0) || (signal_strength > 5)){
2896         return ERROR_CODE_COMMAND_DISALLOWED;
2897     }
2898 
2899     hfp_ag_set_ag_indicator("signal", signal_strength);
2900     return ERROR_CODE_SUCCESS;
2901 }
2902 
2903 uint8_t hfp_ag_set_roaming_status(int roaming_status){
2904     if ((roaming_status < 0) || (roaming_status > 1)){
2905         return ERROR_CODE_COMMAND_DISALLOWED;
2906     }
2907 
2908     hfp_ag_set_ag_indicator("roam", roaming_status);
2909     return ERROR_CODE_SUCCESS;
2910 }
2911 
2912 uint8_t hfp_ag_set_battery_level(int battery_level){
2913     if ((battery_level < 0) || (battery_level > 5)){
2914         return ERROR_CODE_COMMAND_DISALLOWED;
2915     }
2916     hfp_ag_set_ag_indicator("battchg", battery_level);
2917     return ERROR_CODE_SUCCESS;
2918 }
2919 
2920 uint8_t hfp_ag_activate_voice_recognition(hci_con_handle_t acl_handle){
2921     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2922     if (!hfp_connection){
2923         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2924     }
2925 
2926     if (hfp_connection->emit_vra_enabled_after_audio_established){
2927         return ERROR_CODE_COMMAND_DISALLOWED;
2928     }
2929 
2930     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2931     bool legacy_vra_supported   = hfp_ag_vra_flag_supported(hfp_connection);
2932     if (!enhanced_vra_supported && !legacy_vra_supported){
2933         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2934     }
2935 
2936     if (!hfp_ag_can_activate_voice_recognition(hfp_connection)){
2937         return ERROR_CODE_COMMAND_DISALLOWED;
2938     }
2939 
2940     hfp_connection->ag_activate_voice_recognition_value = 1;
2941     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED;
2942     hfp_connection->enhanced_voice_recognition_enabled = enhanced_vra_supported;
2943     hfp_connection->ag_audio_connection_opened_before_vra = hfp_ag_is_audio_connection_active(hfp_connection);
2944     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2945     hfp_connection->ag_vra_send_command = true;
2946     hfp_ag_run_for_context(hfp_connection);
2947     return ERROR_CODE_SUCCESS;
2948 }
2949 
2950 uint8_t hfp_ag_deactivate_voice_recognition(hci_con_handle_t acl_handle){
2951     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2952     if (!hfp_connection){
2953         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2954     }
2955 
2956     if (hfp_connection->emit_vra_enabled_after_audio_established){
2957         return ERROR_CODE_COMMAND_DISALLOWED;
2958     }
2959 
2960     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2961     bool legacy_vra_supported = hfp_ag_vra_flag_supported(hfp_connection);
2962 
2963     if (!enhanced_vra_supported && !legacy_vra_supported){
2964         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2965     }
2966 
2967     if (!hfp_ag_voice_recognition_session_active(hfp_connection)){
2968         return ERROR_CODE_COMMAND_DISALLOWED;
2969     }
2970 
2971     hfp_connection->ag_activate_voice_recognition_value = 0;
2972     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF;
2973     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2974     hfp_connection->ag_vra_send_command = true;
2975     hfp_ag_run_for_context(hfp_connection);
2976     return ERROR_CODE_SUCCESS;
2977 }
2978 
2979 static uint8_t hfp_ag_enhanced_voice_recognition_send_state(hci_con_handle_t acl_handle, hfp_voice_recognition_state_t state){
2980     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2981     if (!hfp_connection){
2982         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2983     }
2984 
2985     if (hfp_connection->emit_vra_enabled_after_audio_established){
2986         return ERROR_CODE_COMMAND_DISALLOWED;
2987     }
2988 
2989     if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED){
2990         return ERROR_CODE_COMMAND_DISALLOWED;
2991     }
2992 
2993     if (hfp_connection->vra_state != HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
2994         return ERROR_CODE_COMMAND_DISALLOWED;
2995     }
2996 
2997     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2998     if (!enhanced_vra_supported ){
2999         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3000     }
3001 
3002 
3003     hfp_connection->ag_vra_state = state;
3004     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_STATUS;
3005     hfp_connection->ag_vra_send_command = true;
3006     hfp_ag_run_for_context(hfp_connection);
3007     return ERROR_CODE_SUCCESS;
3008 }
3009 
3010 uint8_t hfp_ag_enhanced_voice_recognition_report_sending_audio(hci_con_handle_t acl_handle){
3011     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_STARTING_SOUND);
3012 }
3013 uint8_t hfp_ag_enhanced_voice_recognition_report_ready_for_audio(hci_con_handle_t acl_handle){
3014     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_READY_TO_ACCEPT_AUDIO_INPUT);
3015 }
3016 uint8_t hfp_ag_enhanced_voice_recognition_report_processing_input(hci_con_handle_t acl_handle){
3017     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_PROCESSING_AUDIO_INPUT);
3018 }
3019 
3020 
3021 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){
3022     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3023     if (!hfp_connection){
3024         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3025     }
3026 
3027     if (hfp_connection->emit_vra_enabled_after_audio_established){
3028         return ERROR_CODE_COMMAND_DISALLOWED;
3029     }
3030 
3031     if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED){
3032         return ERROR_CODE_COMMAND_DISALLOWED;
3033     }
3034 
3035     if (hfp_connection->vra_state != HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
3036         return ERROR_CODE_COMMAND_DISALLOWED;
3037     }
3038 
3039     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
3040     if (!enhanced_vra_supported ){
3041         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3042     }
3043 
3044     bool enhanced_vra_msg_supported = hfp_ag_can_send_enhanced_vra_message_flag_supported(hfp_connection);
3045     if (!enhanced_vra_msg_supported ){
3046         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3047     }
3048 
3049     uint16_t message_len = (uint16_t) strlen(msg.text);
3050 
3051     if (message_len > HFP_MAX_VR_TEXT_SIZE){
3052         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3053     }
3054 
3055     if ((HFP_VR_TEXT_HEADER_SIZE + message_len) > hfp_connection->rfcomm_mtu){
3056         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3057     }
3058 
3059     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_MSG;
3060     hfp_connection->ag_msg = msg;
3061     hfp_connection->ag_vra_state = state;
3062     hfp_connection->ag_vra_send_command = true;
3063     hfp_ag_run_for_context(hfp_connection);
3064 
3065     return ERROR_CODE_SUCCESS;
3066 }
3067 
3068 
3069 uint8_t hfp_ag_set_microphone_gain(hci_con_handle_t acl_handle, int gain){
3070     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3071     if (!hfp_connection){
3072         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3073     }
3074 
3075     if ((gain < 0) || (gain > 15)){
3076         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
3077         return ERROR_CODE_COMMAND_DISALLOWED;
3078     }
3079 
3080     if (hfp_connection->microphone_gain != gain){
3081         hfp_connection->microphone_gain = gain;
3082         hfp_connection->send_microphone_gain = 1;
3083     }
3084     hfp_ag_run_for_context(hfp_connection);
3085     return ERROR_CODE_SUCCESS;
3086 }
3087 
3088 uint8_t hfp_ag_set_speaker_gain(hci_con_handle_t acl_handle, int gain){
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     if ((gain < 0) || (gain > 15)){
3095         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
3096         return ERROR_CODE_COMMAND_DISALLOWED;
3097     }
3098 
3099     if (hfp_connection->speaker_gain != gain){
3100         hfp_connection->speaker_gain = gain;
3101         hfp_connection->send_speaker_gain = 1;
3102     }
3103     hfp_ag_run_for_context(hfp_connection);
3104     return ERROR_CODE_SUCCESS;
3105 }
3106 
3107 uint8_t hfp_ag_send_phone_number_for_voice_tag(hci_con_handle_t acl_handle, const char * number){
3108     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3109     if (!hfp_connection){
3110         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3111     }
3112 
3113     hfp_ag_set_clip(0, number);
3114     hfp_connection->send_phone_number_for_voice_tag = 1;
3115     return ERROR_CODE_SUCCESS;
3116 }
3117 
3118 uint8_t hfp_ag_reject_phone_number_for_voice_tag(hci_con_handle_t acl_handle){
3119     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3120     if (!hfp_connection){
3121         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3122     }
3123 
3124     hfp_connection->send_error = 1;
3125     return ERROR_CODE_SUCCESS;
3126 }
3127 
3128 uint8_t hfp_ag_send_dtmf_code_done(hci_con_handle_t acl_handle){
3129     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3130     if (!hfp_connection){
3131         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3132     }
3133 
3134     hfp_connection->ok_pending = 1;
3135     return ERROR_CODE_SUCCESS;
3136 }
3137 
3138 uint8_t hfp_ag_send_unsolicited_result_code(hci_con_handle_t acl_handle, const char * unsolicited_result_code){
3139     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3140     if (!hfp_connection){
3141         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3142     }
3143     if (hfp_connection->send_custom_message != NULL){
3144         return ERROR_CODE_COMMAND_DISALLOWED;
3145     }
3146     hfp_connection->send_custom_message = unsolicited_result_code;
3147     hfp_ag_run_for_context(hfp_connection);
3148     return ERROR_CODE_SUCCESS;
3149 }
3150 
3151 uint8_t hfp_ag_send_command_result_code(hci_con_handle_t acl_handle, bool ok){
3152     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3153     if (!hfp_connection){
3154         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3155     }
3156     if (ok){
3157         hfp_connection->ok_pending = 1;
3158     } else {
3159         hfp_connection->send_error = 1;
3160     }
3161     hfp_ag_run_for_context(hfp_connection);
3162     return ERROR_CODE_SUCCESS;
3163 }
3164 
3165 void hfp_ag_set_subcriber_number_information(hfp_phone_number_t * numbers, int numbers_count){
3166     hfp_ag_subscriber_numbers = numbers;
3167     hfp_ag_subscriber_numbers_count = numbers_count;
3168 }
3169 
3170 void hfp_ag_clear_last_dialed_number(void){
3171     hfp_gsm_clear_last_dialed_number();
3172 }
3173 
3174 void hfp_ag_set_last_dialed_number(const char * number){
3175     hfp_gsm_set_last_dialed_number(number);
3176 }
3177 
3178 uint8_t hfp_ag_notify_incoming_call_waiting(hci_con_handle_t acl_handle){
3179     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3180     if (!hfp_connection){
3181         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3182     }
3183 
3184     if (!hfp_connection->call_waiting_notification_enabled){
3185         return ERROR_CODE_COMMAND_DISALLOWED;
3186     }
3187 
3188     hfp_connection->ag_notify_incoming_call_waiting = 1;
3189     hfp_ag_run_for_context(hfp_connection);
3190     return ERROR_CODE_SUCCESS;
3191 }
3192 
3193 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){
3194 	if (!name){
3195 		name = hfp_ag_default_service_name;
3196 	}
3197 	hfp_create_sdp_record(service, service_record_handle, BLUETOOTH_SERVICE_CLASS_HANDSFREE_AUDIO_GATEWAY, rfcomm_channel_nr, name);
3198 
3199 	/*
3200 	 * 0x01 – Ability to reject a call
3201 	 * 0x00 – No ability to reject a call
3202 	 */
3203 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0301);    // Hands-Free Profile - Network
3204 	de_add_number(service, DE_UINT, DE_SIZE_8, ability_to_reject_call);
3205 
3206 	// Construct SupportedFeatures for SDP bitmap:
3207 	//
3208 	// "The values of the “SupportedFeatures” bitmap given in Table 5.4 shall be the same as the values
3209 	//  of the Bits 0 to 4 of the unsolicited result code +BRSF"
3210 	//
3211 	// Wide band speech (bit 5) requires Codec negotiation
3212 	//
3213 	uint16_t sdp_features = supported_features & 0x1f;
3214 	if ( (wide_band_speech == 1) && (supported_features & (1 << HFP_AGSF_CODEC_NEGOTIATION))){
3215 		sdp_features |= 1 << 5;
3216 	}
3217 
3218     if (supported_features & (1 << HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS)){
3219         sdp_features |= 1 << 6;
3220     }
3221 
3222     if (supported_features & (1 << HFP_AGSF_VOICE_RECOGNITION_TEXT)){
3223         sdp_features |= 1 << 7;
3224     }
3225 
3226 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);    // Hands-Free Profile - SupportedFeatures
3227 	de_add_number(service, DE_UINT, DE_SIZE_16, sdp_features);
3228 }
3229 
3230 void hfp_ag_register_packet_handler(btstack_packet_handler_t callback){
3231 	btstack_assert(callback != NULL);
3232 
3233 	hfp_ag_callback = callback;
3234 	hfp_set_ag_callback(callback);
3235 }
3236 
3237 void hfp_ag_register_custom_call_sm_handler(bool (*handler)(hfp_ag_call_event_t event)){
3238     hfp_ag_custom_call_sm_handler = handler;
3239 }
3240 
3241 void hfp_ag_register_custom_at_command(hfp_custom_at_command_t * custom_at_command){
3242     hfp_register_custom_ag_command(custom_at_command);
3243 }
3244