xref: /btstack/src/classic/hfp_ag.c (revision c824d78c0a34df89b57d535abafcc7dacf30bb06)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hfp_ag.c"
39 
40 // *****************************************************************************
41 //
42 // HFP Audio Gateway (AG) unit
43 //
44 // *****************************************************************************
45 
46 #include "btstack_config.h"
47 
48 #include <stdint.h>
49 #include <stdio.h>
50 #include <string.h>
51 
52 #include "hci_cmd.h"
53 #include "btstack_run_loop.h"
54 
55 #include "bluetooth_sdp.h"
56 #include "hci.h"
57 #include "btstack_memory.h"
58 #include "hci_dump.h"
59 #include "l2cap.h"
60 #include "btstack_debug.h"
61 #include "btstack_event.h"
62 #include "classic/core.h"
63 #include "classic/hfp.h"
64 #include "classic/hfp_ag.h"
65 #include "classic/hfp_gsm_model.h"
66 #include "classic/sdp_client_rfcomm.h"
67 #include "classic/sdp_server.h"
68 #include "classic/sdp_util.h"
69 
70 // private prototypes
71 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection);
72 static void hfp_ag_hf_start_ringing_incoming(hfp_connection_t * hfp_connection);
73 static void hfp_ag_hf_start_ringing_outgoing(hfp_connection_t * hfp_connection);
74 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection);
75 
76 // public prototypes
77 hfp_generic_status_indicator_t * get_hfp_generic_status_indicators(void);
78 int get_hfp_generic_status_indicators_nr(void);
79 void set_hfp_generic_status_indicators(hfp_generic_status_indicator_t * indicators, int indicator_nr);
80 void set_hfp_ag_indicators(hfp_ag_indicator_t * indicators, int indicator_nr);
81 int get_hfp_ag_indicators_nr(hfp_connection_t * context);
82 hfp_ag_indicator_t * get_hfp_ag_indicators(hfp_connection_t * context);
83 
84 #define HFP_SUBEVENT_INVALID 0xFFFF
85 
86 // const
87 static const char hfp_ag_default_service_name[] = "Voice gateway";
88 
89 // globals
90 
91 // higher layer callbacks
92 static btstack_packet_handler_t hfp_ag_callback;
93 
94 static bool (*hfp_ag_custom_call_sm_handler)(hfp_ag_call_event_t event);
95 
96 static btstack_packet_callback_registration_t hfp_ag_hci_event_callback_registration;
97 
98 static uint16_t hfp_ag_supported_features;
99 
100 // codecs
101 static uint8_t hfp_ag_codecs_nr;
102 static uint8_t hfp_ag_codecs[HFP_MAX_NUM_CODECS];
103 
104 // AG indicators
105 static int                hfp_ag_indicators_nr;
106 static hfp_ag_indicator_t hfp_ag_indicators[HFP_MAX_NUM_INDICATORS];
107 
108 // generic status indicators
109 static int                            hfp_ag_generic_status_indicators_nr;
110 static hfp_generic_status_indicator_t hfp_ag_generic_status_indicators[HFP_MAX_NUM_INDICATORS];
111 
112 static int    hfp_ag_call_hold_services_nr;
113 static char * hfp_ag_call_hold_services[6];
114 
115 static hfp_response_and_hold_state_t hfp_ag_response_and_hold_state;
116 static bool hfp_ag_response_and_hold_active = false;
117 
118 // Subscriber information entries
119 static hfp_phone_number_t * hfp_ag_subscriber_numbers;
120 static int                  hfp_ag_subscriber_numbers_count;
121 
122 // call state
123 static btstack_timer_source_t hfp_ag_ring_timeout;
124 
125 // code
126 static int hfp_ag_get_ag_indicators_nr(hfp_connection_t * hfp_connection){
127     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
128         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
129         (void)memcpy(hfp_connection->ag_indicators, hfp_ag_indicators,
130                      hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
131     }
132     return hfp_connection->ag_indicators_nr;
133 }
134 
135 hfp_ag_indicator_t * hfp_ag_get_ag_indicators(hfp_connection_t * hfp_connection){
136     // TODO: save only value, and value changed in the hfp_connection?
137     if (hfp_connection->ag_indicators_nr != hfp_ag_indicators_nr){
138         hfp_connection->ag_indicators_nr = hfp_ag_indicators_nr;
139         (void)memcpy(hfp_connection->ag_indicators, hfp_ag_indicators,
140                      hfp_ag_indicators_nr * sizeof(hfp_ag_indicator_t));
141     }
142     return (hfp_ag_indicator_t *)&(hfp_connection->ag_indicators);
143 }
144 
145 static hfp_ag_indicator_t * get_ag_indicator_for_name(const char * name){
146     int i;
147     for (i = 0; i < hfp_ag_indicators_nr; i++){
148         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
149             return &hfp_ag_indicators[i];
150         }
151     }
152     return NULL;
153 }
154 
155 static int get_ag_indicator_index_for_name(const char * name){
156     int i;
157     for (i = 0; i < hfp_ag_indicators_nr; i++){
158         if (strcmp(hfp_ag_indicators[i].name, name) == 0){
159             return i;
160         }
161     }
162     return -1;
163 }
164 
165 static hfp_connection_t * get_hfp_ag_connection_context_for_acl_handle(uint16_t handle){
166     btstack_linked_list_iterator_t it;
167     btstack_linked_list_iterator_init(&it, hfp_get_connections());
168     while (btstack_linked_list_iterator_has_next(&it)){
169         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
170         if (hfp_connection->acl_handle != handle)      continue;
171         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
172         return hfp_connection;
173     }
174     return NULL;
175 }
176 
177 static int use_in_band_tone(void){
178     return get_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE);
179 }
180 
181 static int has_codec_negotiation_feature(hfp_connection_t * hfp_connection){
182     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_CODEC_NEGOTIATION);
183     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_CODEC_NEGOTIATION);
184     return hf && ag;
185 }
186 
187 static int has_call_waiting_and_3way_calling_feature(hfp_connection_t * hfp_connection){
188     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_THREE_WAY_CALLING);
189     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_THREE_WAY_CALLING);
190     return hf && ag;
191 }
192 
193 static int has_hf_indicators_feature(hfp_connection_t * hfp_connection){
194     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_HF_INDICATORS);
195     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_HF_INDICATORS);
196     return hf && ag;
197 }
198 
199 /* unsolicited responses */
200 
201 static int hfp_ag_send_change_in_band_ring_tone_setting_cmd(uint16_t cid){
202     char buffer[20];
203     snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n",
204              HFP_CHANGE_IN_BAND_RING_TONE_SETTING, use_in_band_tone());
205     buffer[sizeof(buffer) - 1] = 0;
206     return send_str_over_rfcomm(cid, buffer);
207 }
208 
209 static int hfp_ag_exchange_supported_features_cmd(uint16_t cid){
210     char buffer[40];
211     snprintf(buffer, sizeof(buffer), "\r\n%s:%d\r\n\r\nOK\r\n",
212              HFP_SUPPORTED_FEATURES, hfp_ag_supported_features);
213     buffer[sizeof(buffer) - 1] = 0;
214     return send_str_over_rfcomm(cid, buffer);
215 }
216 
217 static int hfp_ag_send_ok(uint16_t cid){
218     char buffer[10];
219     snprintf(buffer, sizeof(buffer), "\r\nOK\r\n");
220     buffer[sizeof(buffer) - 1] = 0;
221     return send_str_over_rfcomm(cid, buffer);
222 }
223 
224 static int hfp_ag_send_ring(uint16_t cid){
225     return send_str_over_rfcomm(cid, (char *) "\r\nRING\r\n");
226 }
227 
228 static int hfp_ag_send_no_carrier(uint16_t cid){
229     char buffer[15];
230     snprintf(buffer, sizeof(buffer), "\r\nNO CARRIER\r\n");
231     buffer[sizeof(buffer) - 1] = 0;
232     return send_str_over_rfcomm(cid, buffer);
233 }
234 
235 static int hfp_ag_send_clip(uint16_t cid){
236     char buffer[50];
237     snprintf(buffer, sizeof(buffer), "\r\n%s: \"%s\",%u\r\n", HFP_ENABLE_CLIP,
238              hfp_gsm_clip_number(), hfp_gsm_clip_type());
239     buffer[sizeof(buffer) - 1] = 0;
240     return send_str_over_rfcomm(cid, buffer);
241 }
242 
243 static int hfp_send_subscriber_number_cmd(uint16_t cid, uint8_t type, const char * number){
244     char buffer[50];
245     snprintf(buffer, sizeof(buffer), "\r\n%s: ,\"%s\",%u, , \r\n",
246              HFP_SUBSCRIBER_NUMBER_INFORMATION, number, type);
247     buffer[sizeof(buffer) - 1] = 0;
248     return send_str_over_rfcomm(cid, buffer);
249 }
250 
251 static int hfp_ag_send_phone_number_for_voice_tag_cmd(uint16_t cid){
252     char buffer[50];
253     snprintf(buffer, sizeof(buffer), "\r\n%s: %s\r\n",
254              HFP_PHONE_NUMBER_FOR_VOICE_TAG, hfp_gsm_clip_number());
255     buffer[sizeof(buffer) - 1] = 0;
256     return send_str_over_rfcomm(cid, buffer);
257 }
258 
259 static int hfp_ag_send_call_waiting_notification(uint16_t cid){
260     char buffer[50];
261     snprintf(buffer, sizeof(buffer), "\r\n%s: \"%s\",%u\r\n",
262              HFP_ENABLE_CALL_WAITING_NOTIFICATION, hfp_gsm_clip_number(),
263              hfp_gsm_clip_type());
264     buffer[sizeof(buffer) - 1] = 0;
265     return send_str_over_rfcomm(cid, buffer);
266 }
267 
268 static int hfp_ag_send_error(uint16_t cid){
269     char buffer[10];
270     snprintf(buffer, sizeof(buffer), "\r\nERROR\r\n");
271     buffer[sizeof(buffer) - 1] = 0;
272     return send_str_over_rfcomm(cid, buffer);
273 }
274 
275 static int hfp_ag_send_report_extended_audio_gateway_error(uint16_t cid, uint8_t error){
276     char buffer[20];
277     snprintf(buffer, sizeof(buffer), "\r\n%s=%d\r\n",
278              HFP_EXTENDED_AUDIO_GATEWAY_ERROR, error);
279     buffer[sizeof(buffer) - 1] = 0;
280     return send_str_over_rfcomm(cid, buffer);
281 }
282 
283 // get size for indicator string
284 static int hfp_ag_indicators_string_size(hfp_connection_t * hfp_connection, int i){
285     // template: ("$NAME",($MIN,$MAX))
286     return 8 + (int) strlen(hfp_ag_get_ag_indicators(hfp_connection)[i].name)
287          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range)
288          + string_len_for_uint32(hfp_ag_get_ag_indicators(hfp_connection)[i].min_range);
289 }
290 
291 // store indicator
292 static void hfp_ag_indicators_string_store(hfp_connection_t * hfp_connection, int i, uint8_t * buffer, uint16_t buffer_size){
293     snprintf((char *)buffer, buffer_size, "(\"%s\",(%d,%d)),",
294              hfp_ag_get_ag_indicators(hfp_connection)[i].name,
295              hfp_ag_get_ag_indicators(hfp_connection)[i].min_range,
296              hfp_ag_get_ag_indicators(hfp_connection)[i].max_range);
297     ((char *)buffer)[buffer_size - 1] = 0;
298 }
299 
300 // structure: header [indicator [comma indicator]] footer
301 static int hfp_ag_indicators_cmd_generator_num_segments(hfp_connection_t * hfp_connection){
302     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
303     if (!num_indicators) return 2;
304     return 3 + ((num_indicators-1) * 2);
305 }
306 
307 // get size of individual segment for hfp_ag_retrieve_indicators_cmd
308 static int hfp_ag_indicators_cmd_generator_get_segment_len(hfp_connection_t * hfp_connection, int index){
309     if (index == 0) {
310         return (uint16_t) strlen(HFP_INDICATOR) + 3;   // "\n\r%s:""
311     }
312     index--;
313     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
314     int indicator_index = index >> 1;
315     if ((index & 1) == 0){
316         return hfp_ag_indicators_string_size(hfp_connection, indicator_index);
317     }
318     if (indicator_index == (num_indicators - 1)){
319         return 8; // "\r\n\r\nOK\r\n"
320     }
321     return 1; // comma
322 }
323 
324 static void hfp_ag_indicators_cmd_generator_store_segment(hfp_connection_t * hfp_connection, int index, uint8_t * buffer, uint16_t buffer_size){
325     if (index == 0){
326         *buffer++ = '\r';
327         *buffer++ = '\n';
328         int len = (uint16_t) strlen(HFP_INDICATOR);
329         (void)memcpy(buffer, HFP_INDICATOR, len);
330         buffer += len;
331         *buffer++ = ':';
332         return;
333     }
334     index--;
335     int num_indicators = hfp_ag_get_ag_indicators_nr(hfp_connection);
336     int indicator_index = index >> 1;
337     if ((index & 1) == 0){
338         hfp_ag_indicators_string_store(hfp_connection, indicator_index, buffer, buffer_size);
339         return;
340     }
341     if (indicator_index == (num_indicators-1)){
342         (void)memcpy(buffer, "\r\n\r\nOK\r\n", 8);
343         return;
344     }
345     *buffer = ',';
346 }
347 
348 static int hfp_ag_generic_indicators_join(char * buffer, int buffer_size){
349     if (buffer_size < (hfp_ag_indicators_nr * 3)) return 0;
350     int i;
351     int offset = 0;
352     for (i = 0; i < (hfp_ag_generic_status_indicators_nr - 1); i++) {
353         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_ag_generic_status_indicators[i].uuid);
354     }
355     if (i < hfp_ag_generic_status_indicators_nr){
356         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_ag_generic_status_indicators[i].uuid);
357     }
358     return offset;
359 }
360 
361 static int hfp_ag_generic_indicators_initial_status_join(char * buffer, int buffer_size){
362     if (buffer_size < (hfp_ag_generic_status_indicators_nr * 3)) return 0;
363     int i;
364     int offset = 0;
365     for (i = 0; i < hfp_ag_generic_status_indicators_nr; i++) {
366         offset += snprintf(buffer+offset, buffer_size-offset, "\r\n%s:%d,%d\r\n", HFP_GENERIC_STATUS_INDICATOR, hfp_ag_generic_status_indicators[i].uuid, hfp_ag_generic_status_indicators[i].state);
367     }
368     return offset;
369 }
370 
371 static int hfp_ag_indicators_status_join(char * buffer, int buffer_size){
372     if (buffer_size < (hfp_ag_indicators_nr * 3)) return 0;
373     int i;
374     int offset = 0;
375     for (i = 0; i < (hfp_ag_indicators_nr-1); i++) {
376         offset += snprintf(buffer+offset, buffer_size-offset, "%d,", hfp_ag_indicators[i].status);
377     }
378     if (i<hfp_ag_indicators_nr){
379         offset += snprintf(buffer+offset, buffer_size-offset, "%d", hfp_ag_indicators[i].status);
380     }
381     return offset;
382 }
383 
384 static int hfp_ag_call_services_join(char * buffer, int buffer_size){
385     if (buffer_size < (hfp_ag_call_hold_services_nr * 3)) return 0;
386     int i;
387     int offset = snprintf(buffer, buffer_size, "(");
388     for (i = 0; i < (hfp_ag_call_hold_services_nr-1); i++) {
389         offset += snprintf(buffer+offset, buffer_size-offset, "%s,", hfp_ag_call_hold_services[i]);
390     }
391     if (i<hfp_ag_call_hold_services_nr){
392         offset += snprintf(buffer+offset, buffer_size-offset, "%s)", hfp_ag_call_hold_services[i]);
393     }
394     return offset;
395 }
396 
397 static int hfp_ag_send_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection,
398     int start_segment, int num_segments,
399     int (*get_segment_len)(hfp_connection_t * hfp_connection, int segment),
400     void (*store_segment) (hfp_connection_t * hfp_connection, int segment, uint8_t * buffer, uint16_t buffer_size)){
401 
402     // assumes: can send now == true
403     // assumes: num segments > 0
404     // assumes: individual segments are smaller than MTU
405     rfcomm_reserve_packet_buffer();
406     int mtu = rfcomm_get_max_frame_size(cid);
407     uint8_t * data = rfcomm_get_outgoing_buffer();
408     int offset = 0;
409     int segment = start_segment;
410     while (segment < num_segments){
411         int segment_len = get_segment_len(hfp_connection, segment);
412         if ((offset + segment_len + 1) > mtu) break;
413         // append segment. As it appends a '\0', we provide a buffer one byte larger
414         store_segment(hfp_connection, segment, data+offset, segment_len + 1);
415         offset += segment_len;
416         segment++;
417     }
418     rfcomm_send_prepared(cid, offset);
419 #ifdef ENABLE_HFP_AT_MESSAGES
420     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_SENT, (char *) data);
421 #endif
422     return segment;
423 }
424 
425 // returns next segment to store
426 static int hfp_ag_send_retrieve_indicators_cmd_via_generator(uint16_t cid, hfp_connection_t * hfp_connection, int start_segment){
427     int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
428     return hfp_ag_send_cmd_via_generator(cid, hfp_connection, start_segment, num_segments,
429                                          hfp_ag_indicators_cmd_generator_get_segment_len,
430                                          hfp_ag_indicators_cmd_generator_store_segment);
431 }
432 
433 static int hfp_ag_send_retrieve_indicators_status_cmd(uint16_t cid){
434     char buffer[40];
435     const int size = sizeof(buffer);
436     int offset = snprintf(buffer, size, "\r\n%s:", HFP_INDICATOR);
437     offset += hfp_ag_indicators_status_join(buffer+offset, size-offset-9);
438     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
439     return send_str_over_rfcomm(cid, buffer);
440 }
441 
442 static int hfp_ag_send_retrieve_can_hold_call_cmd(uint16_t cid){
443     char buffer[40];
444     const int size = sizeof(buffer);
445     int offset = snprintf(buffer, size, "\r\n%s:", HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES);
446     offset += hfp_ag_call_services_join(buffer+offset, size-offset-9);
447     offset += snprintf(buffer+offset, size-offset, "\r\n\r\nOK\r\n");
448     return send_str_over_rfcomm(cid, buffer);
449 }
450 
451 
452 static int hfp_ag_send_list_supported_generic_status_indicators_cmd(uint16_t cid){
453     return hfp_ag_send_ok(cid);
454 }
455 
456 static int hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(uint16_t cid){
457     char buffer[40];
458     const int size = sizeof(buffer);
459     int offset = snprintf(buffer, size, "\r\n%s:(", HFP_GENERIC_STATUS_INDICATOR);
460     offset += hfp_ag_generic_indicators_join(buffer + offset, size - offset - 10);
461     offset += snprintf(buffer+offset, size-offset, ")\r\n\r\nOK\r\n");
462     return send_str_over_rfcomm(cid, buffer);
463 }
464 
465 static int hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(uint16_t cid){
466     char buffer[40];
467     int offset = hfp_ag_generic_indicators_initial_status_join(buffer, sizeof(buffer) - 7);
468     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\nOK\r\n");
469     return send_str_over_rfcomm(cid, buffer);
470 }
471 
472 static int hfp_ag_send_transfer_ag_indicators_status_cmd(uint16_t cid, hfp_ag_indicator_t * indicator){
473     char buffer[20];
474     snprintf(buffer, sizeof(buffer), "\r\n%s:%d,%d\r\n",
475              HFP_TRANSFER_AG_INDICATOR_STATUS, indicator->index,
476              indicator->status);
477     buffer[sizeof(buffer) - 1] = 0;
478     return send_str_over_rfcomm(cid, buffer);
479 }
480 
481 static int hfp_ag_send_report_network_operator_name_cmd(uint16_t cid, hfp_network_opearator_t op){
482     char buffer[41];
483     if (strlen(op.name) == 0){
484         snprintf(buffer, sizeof(buffer), "\r\n%s:%d,,\r\n\r\nOK\r\n", HFP_QUERY_OPERATOR_SELECTION, op.mode);
485     } else {
486         int offset = snprintf(buffer,  sizeof(buffer), "\r\n%s:%d,%d,", HFP_QUERY_OPERATOR_SELECTION, op.mode, op.format);
487         offset += snprintf(buffer+offset, 16, "%s", op.name);
488         snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n\r\nOK\r\n");
489     }
490     return send_str_over_rfcomm(cid, buffer);
491 }
492 
493 static inline int hfp_ag_send_cmd_with_space_and_int(uint16_t cid, const char * cmd, uint8_t value){
494     char buffer[30];
495     snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n", cmd, value);
496     return send_str_over_rfcomm(cid, buffer);
497 }
498 
499 
500 static inline int hfp_ag_send_cmd_with_int(uint16_t cid, const char * cmd, uint8_t value){
501     char buffer[30];
502     snprintf(buffer, sizeof(buffer), "\r\n%s:%d\r\n", cmd, value);
503     return send_str_over_rfcomm(cid, buffer);
504 }
505 
506 static int hfp_ag_send_suggest_codec_cmd(uint16_t cid, uint8_t codec){
507     return hfp_ag_send_cmd_with_int(cid, HFP_CONFIRM_COMMON_CODEC, codec);
508 }
509 
510 static int hfp_ag_send_set_speaker_gain_cmd(uint16_t cid, uint8_t gain){
511     return hfp_ag_send_cmd_with_int(cid, HFP_SET_SPEAKER_GAIN, gain);
512 }
513 
514 static int hfp_ag_send_set_microphone_gain_cmd(uint16_t cid, uint8_t gain){
515     return hfp_ag_send_cmd_with_int(cid, HFP_SET_MICROPHONE_GAIN, gain);
516 }
517 
518 static int hfp_ag_send_set_response_and_hold(uint16_t cid, int state){
519     return hfp_ag_send_cmd_with_space_and_int(cid, HFP_RESPONSE_AND_HOLD, state);
520 }
521 
522 static int hfp_ag_send_enhanced_voice_recognition_state_cmd(hfp_connection_t * hfp_connection){
523     char buffer[30];
524     uint8_t evra_enabled = hfp_connection->enhanced_voice_recognition_enabled ? 1 : 0;
525     snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, evra_enabled, hfp_connection->ag_vra_state);
526     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
527 }
528 
529 static int hfp_ag_send_voice_recognition_cmd(hfp_connection_t * hfp_connection, uint8_t activate_voice_recognition){
530     char buffer[30];
531     if (hfp_connection->enhanced_voice_recognition_enabled){
532         snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, activate_voice_recognition, hfp_connection->ag_vra_state);
533     } else {
534         snprintf(buffer, sizeof(buffer), "\r\n%s: %d\r\n", HFP_ACTIVATE_VOICE_RECOGNITION, activate_voice_recognition);
535     }
536     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
537 }
538 
539 static int hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection_t * hfp_connection){
540     char buffer[HFP_VR_TEXT_HEADER_SIZE + HFP_MAX_VR_TEXT_SIZE];
541     snprintf(buffer, sizeof(buffer), "\r\n%s: 1,%d,%X,%d,%d,\"%s\"\r\n", HFP_ACTIVATE_VOICE_RECOGNITION,
542         hfp_connection->ag_vra_state,
543         hfp_connection->ag_msg.text_id,
544         hfp_connection->ag_msg.text_type,
545         hfp_connection->ag_msg.text_operation,
546         hfp_connection->ag_msg.text);
547     return send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
548 }
549 
550 static uint8_t hfp_ag_suggest_codec(hfp_connection_t *hfp_connection){
551     if (hfp_connection->sco_for_msbc_failed) return HFP_CODEC_CVSD;
552 
553     if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_ag_codecs_nr, hfp_ag_codecs)){
554         if (hfp_supports_codec(HFP_CODEC_MSBC, hfp_connection->remote_codecs_nr, hfp_connection->remote_codecs)){
555             return HFP_CODEC_MSBC;
556         }
557     }
558     return HFP_CODEC_CVSD;
559 }
560 
561 /* state machines */
562 
563 static uint8_t hfp_ag_esco_s4_supported(hfp_connection_t * hfp_connection){
564     return (hfp_connection->remote_supported_features & (1<<HFP_HFSF_ESCO_S4)) &&  (hfp_ag_supported_features & (1 << HFP_AGSF_ESCO_S4));
565 }
566 
567 static int codecs_exchange_state_machine(hfp_connection_t * hfp_connection){
568     /* events ( == commands):
569         HFP_CMD_AVAILABLE_CODECS == received AT+BAC with list of codecs
570         HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
571             hf_trigger_codec_connection_setup == received BCC
572             ag_trigger_codec_connection_setup == received from AG to send BCS
573         HFP_CMD_HF_CONFIRMED_CODEC == received AT+BCS
574     */
575     switch (hfp_connection->codecs_state){
576         case HFP_CODECS_EXCHANGED:
577             if (hfp_connection->command == HFP_CMD_AVAILABLE_CODECS){
578                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
579                 return 1;
580             }
581             break;
582 
583         case HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE:
584         case HFP_CODECS_AG_RESEND_COMMON_CODEC:
585             hfp_connection->ag_send_common_codec = true;
586             break;
587         default:
588             break;
589     }
590 
591     if (hfp_connection->ag_send_common_codec){
592         hfp_connection->ag_send_common_codec = false;
593         hfp_connection->codecs_state = HFP_CODECS_AG_SENT_COMMON_CODEC;
594         hfp_connection->suggested_codec = hfp_ag_suggest_codec(hfp_connection);
595         hfp_ag_send_suggest_codec_cmd(hfp_connection->rfcomm_cid, hfp_connection->suggested_codec);
596         return 1;
597     }
598 
599     switch (hfp_connection->command){
600         case HFP_CMD_AVAILABLE_CODECS:
601             if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED){
602                 hfp_connection->codecs_state = HFP_CODECS_RECEIVED_LIST;
603                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
604                 return 1;
605             }
606 
607             switch (hfp_connection->codecs_state){
608                 case HFP_CODECS_AG_SENT_COMMON_CODEC:
609                     hfp_connection->codecs_state = HFP_CODECS_AG_RESEND_COMMON_CODEC;
610                     break;
611                 default:
612                     break;
613             }
614             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
615             return 1;
616 
617         case HFP_CMD_TRIGGER_CODEC_CONNECTION_SETUP:
618             hfp_connection->codecs_state = HFP_CODECS_RECEIVED_TRIGGER_CODEC_EXCHANGE;
619             hfp_connection->establish_audio_connection = 1;
620             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
621             return 1;
622 
623         case HFP_CMD_HF_CONFIRMED_CODEC:
624             if (hfp_connection->codec_confirmed != hfp_connection->suggested_codec){
625                 hfp_connection->codecs_state = HFP_CODECS_ERROR;
626                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
627                 return 1;
628             }
629             hfp_connection->negotiated_codec = hfp_connection->codec_confirmed;
630             hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
631             log_info("hfp: codec confirmed: %s", (hfp_connection->negotiated_codec == HFP_CODEC_MSBC) ? "mSBC" : "CVSD");
632             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
633             // now, pick link settings
634             hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
635 #ifdef ENABLE_CC256X_ASSISTED_HFP
636             hfp_cc256x_prepare_for_sco(hfp_connection);
637 #endif
638 #ifdef ENABLE_RTK_PCM_WBS
639             hfp_connection->rtk_send_sco_config = true;
640 #endif
641             return 1;
642         default:
643             break;
644     }
645     return 0;
646 }
647 
648 static void hfp_ag_slc_established(hfp_connection_t * hfp_connection){
649     hfp_connection->state = HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED;
650     hfp_emit_slc_connection_event(hfp_connection->local_role, 0, hfp_connection->acl_handle, hfp_connection->remote_addr);
651 
652     // HFP 4.35: "When [...] a new Service Level Connection is established all indicators are activated by default."
653     uint16_t i;
654     for (i=0;i<hfp_connection->ag_indicators_nr;i++){
655         hfp_connection->ag_indicators[i].enabled = 1;
656     }
657 
658     // if active call exist, set per-hfp_connection state active, too (when audio is on)
659     if (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT){
660         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
661     }
662     // if AG is ringing, also start ringing on the HF
663     if (hfp_gsm_call_status() == HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS){
664         switch (hfp_gsm_callsetup_status()){
665             case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
666                 hfp_ag_hf_start_ringing_incoming(hfp_connection);
667                 break;
668             case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
669                 hfp_ag_hf_start_ringing_outgoing(hfp_connection);
670                 break;
671             default:
672                 break;
673         }
674     }
675 }
676 
677 static int hfp_ag_run_for_context_service_level_connection(hfp_connection_t * hfp_connection){
678     // log_info("hfp_ag_run_for_context_service_level_connection state %u, command %u", hfp_connection->state, hfp_connection->command);
679     if (hfp_connection->state >= HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) return 0;
680     int sent = 0;
681     switch(hfp_connection->command){
682         case HFP_CMD_SUPPORTED_FEATURES:
683             switch(hfp_connection->state){
684                 case HFP_W4_EXCHANGE_SUPPORTED_FEATURES:
685                 case HFP_EXCHANGE_SUPPORTED_FEATURES:
686                     hfp_hf_drop_mSBC_if_eSCO_not_supported(hfp_ag_codecs, &hfp_ag_codecs_nr);
687                     if (has_codec_negotiation_feature(hfp_connection)){
688                         hfp_connection->state = HFP_W4_NOTIFY_ON_CODECS;
689                     } else {
690                         hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
691                     }
692                     hfp_ag_exchange_supported_features_cmd(hfp_connection->rfcomm_cid);
693                     return 1;
694                 default:
695                     break;
696             }
697             break;
698         case HFP_CMD_AVAILABLE_CODECS:
699             sent = codecs_exchange_state_machine(hfp_connection);
700             if (hfp_connection->codecs_state == HFP_CODECS_RECEIVED_LIST){
701                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS;
702             }
703             return sent;
704 
705         case HFP_CMD_RETRIEVE_AG_INDICATORS:
706             if (hfp_connection->state == HFP_W4_RETRIEVE_INDICATORS) {
707                 // HF requested AG Indicators and we did expect it
708                 hfp_connection->send_ag_indicators_segment = 0;
709                 hfp_connection->state = HFP_RETRIEVE_INDICATORS;
710                 // continue below in state switch
711             }
712             break;
713 
714         case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
715             if (hfp_connection->state != HFP_W4_RETRIEVE_INDICATORS_STATUS) break;
716             hfp_connection->state = HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE;
717             hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
718             return 1;
719 
720         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
721             if (hfp_connection->state != HFP_W4_ENABLE_INDICATORS_STATUS_UPDATE) break;
722             if (has_call_waiting_and_3way_calling_feature(hfp_connection)){
723                 hfp_connection->state = HFP_W4_RETRIEVE_CAN_HOLD_CALL;
724             } else if (has_hf_indicators_feature(hfp_connection)){
725                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
726             } else {
727                 hfp_ag_slc_established(hfp_connection);
728             }
729             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
730             return 1;
731 
732         case HFP_CMD_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES:
733             if (hfp_connection->state != HFP_W4_RETRIEVE_CAN_HOLD_CALL) break;
734             if (has_hf_indicators_feature(hfp_connection)){
735                 hfp_connection->state = HFP_W4_LIST_GENERIC_STATUS_INDICATORS;
736             }
737             hfp_ag_send_retrieve_can_hold_call_cmd(hfp_connection->rfcomm_cid);
738             if (!has_hf_indicators_feature(hfp_connection)){
739                 hfp_ag_slc_established(hfp_connection);
740             }
741             return 1;
742 
743         case HFP_CMD_LIST_GENERIC_STATUS_INDICATORS:
744             if (hfp_connection->state != HFP_W4_LIST_GENERIC_STATUS_INDICATORS) break;
745             hfp_connection->state = HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS;
746             hfp_ag_send_list_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
747             return 1;
748 
749         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS:
750             if (hfp_connection->state != HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS) break;
751             hfp_connection->state = HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS;
752             hfp_ag_send_retrieve_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
753             return 1;
754 
755         case HFP_CMD_RETRIEVE_GENERIC_STATUS_INDICATORS_STATE:
756             if (hfp_connection->state != HFP_W4_RETRIEVE_INITITAL_STATE_GENERIC_STATUS_INDICATORS) break;
757             hfp_ag_slc_established(hfp_connection);
758             hfp_ag_send_retrieve_initital_supported_generic_status_indicators_cmd(hfp_connection->rfcomm_cid);
759             return 1;
760         default:
761             break;
762     }
763 
764     switch (hfp_connection->state){
765         case HFP_RETRIEVE_INDICATORS: {
766             int next_segment = hfp_ag_send_retrieve_indicators_cmd_via_generator(hfp_connection->rfcomm_cid, hfp_connection, hfp_connection->send_ag_indicators_segment);
767             int num_segments = hfp_ag_indicators_cmd_generator_num_segments(hfp_connection);
768             log_info("HFP_CMD_RETRIEVE_AG_INDICATORS next segment %u, num_segments %u", next_segment, num_segments);
769             if (next_segment < num_segments){
770                 // prepare sending of next segment
771                 hfp_connection->send_ag_indicators_segment = next_segment;
772                 log_info("HFP_CMD_RETRIEVE_AG_INDICATORS more. command %u, next seg %u", hfp_connection->command, next_segment);
773             } else {
774                 // done, go to next state
775                 hfp_connection->send_ag_indicators_segment = 0;
776                 hfp_connection->state = HFP_W4_RETRIEVE_INDICATORS_STATUS;
777             }
778             return 1;
779         }
780         default:
781             break;
782     }
783     return 0;
784 }
785 
786 static bool hfp_ag_vra_flag_supported(hfp_connection_t * hfp_connection){
787     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_VOICE_RECOGNITION_FUNCTION);
788     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_FUNCTION);
789     return hf && ag;
790 }
791 
792 static bool hfp_ag_enhanced_vra_flag_supported(hfp_connection_t * hfp_connection){
793     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS);
794     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_ENHANCED_VOICE_RECOGNITION_STATUS);
795     return hf && ag;
796 }
797 
798 static bool hfp_ag_can_send_enhanced_vra_message_flag_supported(hfp_connection_t * hfp_connection){
799     int ag = get_bit(hfp_ag_supported_features, HFP_AGSF_VOICE_RECOGNITION_TEXT);
800     int hf = get_bit(hfp_connection->remote_supported_features, HFP_HFSF_VOICE_RECOGNITION_TEXT);
801     return hf && ag;
802 }
803 
804 static bool hfp_ag_can_activate_voice_recognition(hfp_connection_t * hfp_connection){
805     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED || hfp_connection->state > HFP_AUDIO_CONNECTION_ESTABLISHED){
806         return false;
807     }
808     if (hfp_connection->vra_state != HFP_VRA_VOICE_RECOGNITION_OFF){
809         return false;
810     }
811     if (hfp_connection->ag_vra_send_command){
812         return false;
813     }
814     return true;
815 }
816 
817 static bool hfp_ag_voice_recognition_session_active(hfp_connection_t * hfp_connection){
818     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED || hfp_connection->state > HFP_AUDIO_CONNECTION_ESTABLISHED){
819         return false;
820     }
821     if (hfp_connection->vra_state != HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
822         if (hfp_connection->vra_state == HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
823             return true;
824         }
825         return false;
826     }
827     return true;
828 }
829 
830 static bool hfp_ag_is_audio_connection_active(hfp_connection_t * hfp_connection){
831     switch (hfp_connection->state){
832         case HFP_W2_CONNECT_SCO:
833         case HFP_W4_SCO_CONNECTED:
834         case HFP_AUDIO_CONNECTION_ESTABLISHED:
835             return true;
836         default:
837             return false;
838     }
839 }
840 
841 static void hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection_t * hfp_connection, uint8_t status){
842     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
843 
844     uint8_t event[6];
845     event[0] = HCI_EVENT_HFP_META;
846     event[1] = sizeof(event) - 2;
847     event[2] = HFP_SUBEVENT_ENHANCED_VOICE_RECOGNITION_AG_MESSAGE_SENT;
848     little_endian_store_16(event, 3, acl_handle);
849     event[5] = status;
850     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
851 }
852 
853 
854 static void hfp_ag_emit_hf_indicator_value(hfp_connection_t * hfp_connection, uint16_t uuid, uint8_t value){
855     hci_con_handle_t acl_handle = (hfp_connection != NULL) ? hfp_connection->acl_handle : HCI_CON_HANDLE_INVALID;
856 
857     uint8_t event[8];
858     event[0] = HCI_EVENT_HFP_META;
859     event[1] = sizeof(event) - 2;
860     event[2] = HFP_SUBEVENT_HF_INDICATOR;
861     little_endian_store_16(event, 3, acl_handle);
862     little_endian_store_16(event, 5, uuid);
863     event[7] = value;
864     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
865 }
866 
867 static void hfp_ag_emit_general_simple_event(uint8_t event_subtype){
868     if (!hfp_ag_callback) return;
869 
870     uint8_t event[5];
871     event[0] = HCI_EVENT_HFP_META;
872     event[1] = sizeof(event) - 2;
873     event[2] = event_subtype;
874     little_endian_store_16(event, 3, HCI_CON_HANDLE_INVALID);
875     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
876 }
877 
878 static void hfp_ag_emit_custom_command_event(hfp_connection_t * hfp_connection){
879     btstack_assert(sizeof(hfp_connection->line_buffer) < (255-5));
880 
881     uint16_t line_len = strlen((const char*)hfp_connection->line_buffer) + 1;
882     uint8_t event[7 + sizeof(hfp_connection->line_buffer)];
883     event[0] = HCI_EVENT_HFP_META;
884     event[1] = 5 + line_len;
885     event[2] = HFP_SUBEVENT_CUSTOM_AT_COMMAND;
886     little_endian_store_16(event, 3, hfp_connection->acl_handle);
887     little_endian_store_16(event, 5, hfp_connection->ag_custom_at_command_id);
888     memcpy(&event[7], hfp_connection->line_buffer, line_len);
889     (*hfp_ag_callback)(HCI_EVENT_PACKET, 0, event, 7 + line_len);
890 }
891 
892 // @return status
893 static uint8_t hfp_ag_vra_state_machine_two(hfp_connection_t * hfp_connection){
894     uint8_t status = ERROR_CODE_SUCCESS;
895     switch (hfp_connection->vra_state_requested){
896         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO:
897             if (!hfp_ag_is_audio_connection_active(hfp_connection)){
898                 status = hfp_ag_setup_audio_connection(hfp_connection);
899                 if (status != ERROR_CODE_SUCCESS){
900                     hfp_connection->vra_state_requested = hfp_connection->vra_state;
901                     hfp_emit_voice_recognition_enabled(hfp_connection, status);
902                     break;
903                 }
904             }
905             hfp_connection->enhanced_voice_recognition_enabled = true;
906             hfp_connection->vra_state = HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO;
907             hfp_connection->vra_state_requested = hfp_connection->vra_state;
908             hfp_emit_enhanced_voice_recognition_hf_ready_for_audio_event(hfp_connection, ERROR_CODE_SUCCESS);
909             break;
910 
911         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF:
912             hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_OFF;
913             hfp_connection->vra_state_requested = hfp_connection->vra_state;
914 
915             // release audio connection only if it was opened after audio VR activated
916             if (hfp_ag_is_audio_connection_active(hfp_connection) && !hfp_connection->ag_audio_connection_opened_before_vra){
917                 hfp_trigger_release_audio_connection(hfp_connection);
918             }
919 
920             hfp_emit_voice_recognition_disabled(hfp_connection, ERROR_CODE_SUCCESS);
921             break;
922 
923         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED:
924             // open only if audio connection does not already exist
925             if (!hfp_ag_is_audio_connection_active(hfp_connection)){
926                 status = hfp_ag_setup_audio_connection(hfp_connection);
927                 if (status != ERROR_CODE_SUCCESS){
928                     hfp_connection->vra_state_requested = hfp_connection->vra_state;
929                     hfp_emit_voice_recognition_enabled(hfp_connection, status);
930                     break;
931                 }
932             }
933 
934             hfp_connection->vra_state = HFP_VRA_VOICE_RECOGNITION_ACTIVATED;
935             hfp_connection->vra_state_requested = hfp_connection->vra_state;
936             hfp_connection->enhanced_voice_recognition_enabled = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
937 
938             if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
939                 hfp_emit_voice_recognition_enabled(hfp_connection, ERROR_CODE_SUCCESS);
940             } else {
941                 hfp_connection->emit_vra_enabled_after_audio_established = true;
942             }
943             break;
944 
945         default:
946             break;
947     }
948     return status;
949 }
950 
951 static uint8_t hfp_ag_vra_send_command(hfp_connection_t * hfp_connection){
952     uint8_t done = 0;
953     uint8_t status;
954 
955     switch (hfp_connection->vra_state_requested){
956         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_MSG:
957             done = hfp_ag_send_enhanced_voice_recognition_msg_cmd(hfp_connection);
958             if (done == 0){
959                 hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection, ERROR_CODE_UNSPECIFIED_ERROR);
960             } else {
961                 hfp_ag_emit_enhanced_voice_recognition_msg_sent_event(hfp_connection, ERROR_CODE_SUCCESS);
962             }
963             hfp_connection->vra_state_requested = hfp_connection->vra_state;
964             return done;
965 
966         case HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_STATUS:
967             done = hfp_ag_send_enhanced_voice_recognition_state_cmd(hfp_connection);
968             if (done == 0){
969                 hfp_emit_enhanced_voice_recognition_state_event(hfp_connection, ERROR_CODE_UNSPECIFIED_ERROR);
970             } else {
971                 hfp_emit_enhanced_voice_recognition_state_event(hfp_connection, ERROR_CODE_SUCCESS);
972             }
973             hfp_connection->vra_state_requested = hfp_connection->vra_state;
974             return done;
975 
976         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED:
977         case HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF:
978             done = hfp_ag_send_voice_recognition_cmd(hfp_connection, hfp_connection->ag_activate_voice_recognition_value);
979             if (done == 0){
980                 hfp_connection->vra_state_requested = hfp_connection->vra_state;
981 
982                 if (hfp_connection->ag_activate_voice_recognition_value == 1){
983                     hfp_emit_voice_recognition_enabled(hfp_connection, done);
984                 } else {
985                     hfp_emit_voice_recognition_disabled(hfp_connection, done);
986                 }
987                 return 0;
988             }
989             status = hfp_ag_vra_state_machine_two(hfp_connection);
990             return (status == ERROR_CODE_SUCCESS) ? 1 : 0;
991 
992         default:
993             log_error("state %u", hfp_connection->vra_state_requested);
994             btstack_assert(false);
995             return 0;
996     }
997 }
998 
999 static int hfp_ag_voice_recognition_state_machine(hfp_connection_t * hfp_connection){
1000     if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) {
1001         return 0;
1002     }
1003     int done = 0;
1004     uint8_t status;
1005 
1006     // VRA action initiated by AG
1007     if (hfp_connection->ag_vra_send_command){
1008         hfp_connection->ag_vra_send_command = false;
1009         return hfp_ag_vra_send_command(hfp_connection);
1010     }
1011 
1012     if (hfp_connection->ag_vra_requested_by_hf){
1013         hfp_connection->ag_vra_requested_by_hf = false;
1014 
1015         // HF initiatied voice recognition, parser extracted activation value
1016         switch (hfp_connection->ag_activate_voice_recognition_value){
1017             case 0:
1018                 if (hfp_ag_voice_recognition_session_active(hfp_connection)){
1019                     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF;
1020                     done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1021                 }
1022                 break;
1023 
1024                 case 1:
1025                     if (hfp_ag_can_activate_voice_recognition(hfp_connection)){
1026                         hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED;
1027                         done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1028                     }
1029                     break;
1030 
1031                     case 2:
1032                         if (hfp_ag_voice_recognition_session_active(hfp_connection)){
1033                             hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO;
1034                             done = hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1035                         }
1036                         break;
1037                         default:
1038                             break;
1039         }
1040         if (done == 0){
1041             hfp_connection->vra_state_requested = hfp_connection->vra_state;
1042             done = hfp_ag_send_error(hfp_connection->rfcomm_cid);
1043             return 1;
1044         }
1045 
1046         status = hfp_ag_vra_state_machine_two(hfp_connection);
1047         return (status == ERROR_CODE_SUCCESS) ? 1 : 0;
1048     }
1049 
1050     return 0;
1051 }
1052 
1053 static int hfp_ag_run_for_context_service_level_connection_queries(hfp_connection_t * hfp_connection){
1054     int sent = codecs_exchange_state_machine(hfp_connection);
1055     if (sent) return 1;
1056 
1057     if (hfp_connection->ag_send_in_band_ring_tone_setting){
1058         hfp_connection->ag_send_in_band_ring_tone_setting = false;
1059         hfp_ag_send_change_in_band_ring_tone_setting_cmd(hfp_connection->rfcomm_cid);
1060         return 1;
1061     }
1062 
1063     switch(hfp_connection->command){
1064         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME:
1065             hfp_ag_send_report_network_operator_name_cmd(hfp_connection->rfcomm_cid, hfp_connection->network_operator);
1066             return 1;
1067         case HFP_CMD_QUERY_OPERATOR_SELECTION_NAME_FORMAT:
1068             if (hfp_connection->network_operator.format != 0){
1069                 hfp_ag_send_error(hfp_connection->rfcomm_cid);
1070             } else {
1071                 hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1072             }
1073             return 1;
1074         case HFP_CMD_ENABLE_INDIVIDUAL_AG_INDICATOR_STATUS_UPDATE:
1075             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1076             return 1;
1077         case HFP_CMD_ENABLE_EXTENDED_AUDIO_GATEWAY_ERROR:
1078             if (hfp_connection->extended_audio_gateway_error){
1079                 hfp_connection->extended_audio_gateway_error = 0;
1080                 hfp_ag_send_report_extended_audio_gateway_error(hfp_connection->rfcomm_cid, hfp_connection->extended_audio_gateway_error_value);
1081                 return 1;
1082             }
1083             break;
1084         case HFP_CMD_ENABLE_INDICATOR_STATUS_UPDATE:
1085             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
1086             return 1;
1087         default:
1088             break;
1089     }
1090     return 0;
1091 }
1092 
1093 static int hfp_ag_run_for_audio_connection(hfp_connection_t * hfp_connection){
1094     if ((hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) ||
1095         (hfp_connection->state > HFP_W2_DISCONNECT_SCO)) return 0;
1096 
1097     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1098 
1099     if (hfp_connection->release_audio_connection){
1100         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
1101         hfp_connection->release_audio_connection = 0;
1102         gap_disconnect(hfp_connection->sco_handle);
1103         return 1;
1104     }
1105 
1106     // accept incoming audio connection (codec negotiation is not used)
1107     if (hfp_connection->accept_sco){
1108         // notify about codec selection if not done already
1109         if (hfp_connection->negotiated_codec == 0){
1110             hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
1111         }
1112         //
1113         bool incoming_eSCO = hfp_connection->accept_sco == 2;
1114         hfp_connection->accept_sco = 0;
1115         hfp_connection->state = HFP_W4_SCO_CONNECTED;
1116         hfp_accept_synchronous_connection(hfp_connection, incoming_eSCO);
1117         return 1;
1118     }
1119 
1120     // run codecs exchange
1121     int sent = codecs_exchange_state_machine(hfp_connection);
1122     if (sent) return 1;
1123 
1124     if (hfp_connection->codecs_state != HFP_CODECS_EXCHANGED) return 0;
1125     if (hfp_connection->establish_audio_connection){
1126         hfp_connection->state = HFP_W4_SCO_CONNECTED;
1127         hfp_connection->establish_audio_connection = 0;
1128         hfp_setup_synchronous_connection(hfp_connection);
1129         return 1;
1130     }
1131     return 0;
1132 }
1133 
1134 static void hfp_ag_set_callsetup_indicator(void){
1135     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callsetup");
1136     if (!indicator){
1137         log_error("hfp_ag_set_callsetup_indicator: callsetup indicator is missing");
1138         return;
1139     };
1140     indicator->status = hfp_gsm_callsetup_status();
1141 }
1142 
1143 static void hfp_ag_set_callheld_indicator(void){
1144     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("callheld");
1145     if (!indicator){
1146         log_error("hfp_ag_set_callheld_state: callheld indicator is missing");
1147         return;
1148     };
1149     indicator->status = hfp_gsm_callheld_status();
1150 }
1151 
1152 //
1153 // transition implementations for hfp_ag_call_state_machine
1154 //
1155 
1156 static void hfp_ag_hf_start_ringing_incoming(hfp_connection_t * hfp_connection){
1157     if (use_in_band_tone()){
1158         hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING;
1159         hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1160     } else {
1161         hfp_connection->call_state = HFP_CALL_INCOMING_RINGING;
1162     }
1163 }
1164 
1165 static void hfp_ag_hf_start_ringing_outgoing(hfp_connection_t * hfp_connection){
1166     hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1167 }
1168 
1169 static void hfp_ag_hf_stop_ringing(hfp_connection_t * hfp_connection){
1170     hfp_connection->ag_ring = 0;
1171     hfp_connection->ag_send_clip = 0;
1172 }
1173 
1174 
1175 static void hfp_ag_trigger_incoming_call_during_active_one(void){
1176     btstack_linked_list_iterator_t it;
1177     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1178     while (btstack_linked_list_iterator_has_next(&it)){
1179         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1180         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1181         if (hfp_connection->call_state != HFP_CALL_ACTIVE) continue;
1182 
1183         hfp_connection->call_state = HFP_CALL_W2_SEND_CALL_WAITING;
1184         hfp_ag_run_for_context(hfp_connection);
1185     }
1186 }
1187 
1188 static void hfp_ag_trigger_ring_and_clip(void) {
1189     btstack_linked_list_iterator_t it;
1190     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1191     while (btstack_linked_list_iterator_has_next(&it)){
1192         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1193         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1194         switch (hfp_connection->call_state){
1195             case HFP_CALL_INCOMING_RINGING:
1196             case HFP_CALL_OUTGOING_RINGING:
1197             case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1198                 // Queue RING on this connection
1199                 hfp_connection->ag_ring = 1;
1200 
1201                 // HFP v1.8, 4.23 Calling Line Identification (CLI) Notification
1202                 // "If the calling subscriber number information is available from the network, the AG shall issue the
1203                 // +CLIP unsolicited result code just after every RING indication when the HF is alerted in an incoming call."
1204                 hfp_connection->ag_send_clip = hfp_gsm_clip_type() && hfp_connection->clip_enabled;
1205 
1206                 // trigger next message
1207                 rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1208                 break;
1209             default:
1210                 break;
1211         }
1212     }
1213 }
1214 
1215 // trigger RING and CLIP messages on connections that are ringing
1216 static void hfp_ag_ring_timeout_handler(btstack_timer_source_t * timer){
1217     hfp_ag_trigger_ring_and_clip();
1218 
1219     btstack_run_loop_set_timer(timer, HFP_RING_PERIOD_MS); // 2 seconds timeout
1220     btstack_run_loop_add_timer(timer);
1221 }
1222 
1223 static void hfp_ag_ring_timeout_stop(void){
1224     btstack_run_loop_remove_timer(&hfp_ag_ring_timeout);
1225 }
1226 
1227 static void hfp_ag_start_ringing(void){
1228     // setup ring timer
1229     btstack_run_loop_remove_timer(&hfp_ag_ring_timeout);
1230     btstack_run_loop_set_timer_handler(&hfp_ag_ring_timeout, hfp_ag_ring_timeout_handler);
1231     btstack_run_loop_set_timer(&hfp_ag_ring_timeout, HFP_RING_PERIOD_MS); // 2 seconds timeout
1232     btstack_run_loop_add_timer(&hfp_ag_ring_timeout);
1233 
1234     // emit start ringing
1235     hfp_ag_emit_general_simple_event(HFP_SUBEVENT_START_RINGING);
1236 
1237     // send initial RING + CLIP
1238     hfp_ag_trigger_ring_and_clip();
1239 }
1240 
1241 static void hfp_ag_stop_ringing(void){
1242     hfp_ag_ring_timeout_stop();
1243     hfp_ag_emit_general_simple_event(HFP_SUBEVENT_STOP_RINGING);
1244 
1245     btstack_linked_list_iterator_t it;
1246     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1247     while (btstack_linked_list_iterator_has_next(&it)){
1248         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1249         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1250         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1251             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1252         hfp_ag_hf_stop_ringing(hfp_connection);
1253     }
1254 }
1255 
1256 static void hfp_ag_trigger_incoming_call_idle(void){
1257     int indicator_index = get_ag_indicator_index_for_name("callsetup");
1258     if (indicator_index < 0) return;
1259 
1260     // update callsetup state in connections
1261     btstack_linked_list_iterator_t it;
1262     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1263     while (btstack_linked_list_iterator_has_next(&it)){
1264         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1265         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1266         if (hfp_connection->call_state != HFP_CALL_IDLE) continue;
1267 
1268         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1269 
1270         hfp_ag_hf_start_ringing_incoming(hfp_connection);
1271 
1272         hfp_ag_run_for_context(hfp_connection);
1273     }
1274 
1275     // start local ringing - started after connection state has been updated
1276     hfp_ag_start_ringing();
1277 }
1278 
1279 static void hfp_ag_trigger_outgoing_call(void){
1280     btstack_linked_list_iterator_t it;
1281     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1282     while (btstack_linked_list_iterator_has_next(&it)){
1283         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1284         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1285         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1286         if (hfp_connection->call_state == HFP_CALL_IDLE){
1287             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1288         }
1289     }
1290 }
1291 
1292 static void hfp_ag_handle_outgoing_call_accepted(hfp_connection_t * hfp_connection){
1293     hfp_connection->call_state = HFP_CALL_OUTGOING_DIALING;
1294 
1295     // trigger callsetup to be
1296     int put_call_on_hold = hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT;
1297     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ACCEPTED, 0, 0, NULL);
1298 
1299     int indicator_index ;
1300 
1301     hfp_ag_set_callsetup_indicator();
1302     indicator_index = get_ag_indicator_index_for_name("callsetup");
1303     hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1304 
1305     // put current call on hold if active
1306     if (put_call_on_hold){
1307         log_info("AG putting current call on hold for new outgoing call");
1308         hfp_ag_set_callheld_indicator();
1309         indicator_index = get_ag_indicator_index_for_name("callheld");
1310         hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[indicator_index]);
1311     }
1312 
1313     // start audio if needed
1314     hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1315 }
1316 
1317 static void hfp_ag_transfer_indicator(const char * name){
1318     int indicator_index = get_ag_indicator_index_for_name(name);
1319     if (indicator_index < 0) return;
1320 
1321     btstack_linked_list_iterator_t it;
1322     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1323     while (btstack_linked_list_iterator_has_next(&it)){
1324         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1325         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1326         hfp_ag_establish_service_level_connection(hfp_connection->remote_addr);
1327         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1328         hfp_ag_run_for_context(hfp_connection);
1329     }
1330 }
1331 
1332 static void hfp_ag_transfer_callsetup_state(void){
1333     hfp_ag_transfer_indicator("callsetup");
1334 }
1335 
1336 static void hfp_ag_transfer_call_state(void){
1337     hfp_ag_transfer_indicator("call");
1338 }
1339 
1340 static void hfp_ag_transfer_callheld_state(void){
1341     hfp_ag_transfer_indicator("callheld");
1342 }
1343 
1344 static void hfp_ag_hf_accept_call(hfp_connection_t * source){
1345     int call_indicator_index = get_ag_indicator_index_for_name("call");
1346     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1347 
1348     hfp_ag_stop_ringing();
1349 
1350     btstack_linked_list_iterator_t it;
1351     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1352     while (btstack_linked_list_iterator_has_next(&it)){
1353         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1354         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1355         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1356             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1357 
1358         if (hfp_connection == source){
1359 
1360             if (use_in_band_tone()){
1361                 hfp_connection->call_state = HFP_CALL_ACTIVE;
1362             } else {
1363                 hfp_connection->call_state = HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE;
1364                 hfp_ag_establish_audio_connection(hfp_connection->acl_handle);
1365             }
1366 
1367             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1368             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1369 
1370         } else {
1371             hfp_connection->call_state = HFP_CALL_IDLE;
1372         }
1373         hfp_ag_run_for_context(hfp_connection);
1374     }
1375 }
1376 
1377 static void hfp_ag_ag_accept_call(void){
1378     int call_indicator_index = get_ag_indicator_index_for_name("call");
1379     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1380 
1381     hfp_ag_stop_ringing();
1382 
1383     btstack_linked_list_iterator_t it;
1384     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1385     while (btstack_linked_list_iterator_has_next(&it)){
1386         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1387         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1388         if ((hfp_connection->call_state != HFP_CALL_INCOMING_RINGING) &&
1389             (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING)) continue;
1390 
1391         hfp_connection->call_state = HFP_CALL_TRIGGER_AUDIO_CONNECTION;
1392 
1393         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1394         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1395 
1396         hfp_ag_run_for_context(hfp_connection);
1397         break;  // only single
1398     }
1399 }
1400 
1401 static void hfp_ag_trigger_reject_call(void){
1402     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1403 
1404     hfp_ag_stop_ringing();
1405 
1406     btstack_linked_list_iterator_t it;
1407     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1408     while (btstack_linked_list_iterator_has_next(&it)){
1409         hfp_connection_t * connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1410         if (connection->local_role != HFP_ROLE_AG) continue;
1411 
1412         switch (connection->call_state){
1413             case HFP_CALL_INCOMING_RINGING:
1414             case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1415             case HFP_CALL_OUTGOING_RINGING:
1416             case HFP_CALL_OUTGOING_INITIATED:
1417             case HFP_CALL_OUTGOING_DIALING:
1418                 break;
1419             default:
1420                 continue;
1421         }
1422 
1423         connection->call_state = HFP_CALL_IDLE;
1424         connection->ag_indicators_status_update_bitmap = store_bit(connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1425 
1426         if (connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1427             connection->release_audio_connection = 1;
1428         }
1429         hfp_emit_simple_event(connection, HFP_SUBEVENT_CALL_TERMINATED);
1430         hfp_ag_run_for_context(connection);
1431         rfcomm_request_can_send_now_event(connection->rfcomm_cid);
1432     }
1433 }
1434 
1435 static void hfp_ag_trigger_terminate_call(void){
1436     int call_indicator_index = get_ag_indicator_index_for_name("call");
1437 
1438     // no ringing during call
1439 
1440     btstack_linked_list_iterator_t it;
1441     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1442     while (btstack_linked_list_iterator_has_next(&it)){
1443         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1444         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1445         if (hfp_connection->call_state == HFP_CALL_IDLE) continue;
1446 
1447         hfp_connection->call_state = HFP_CALL_IDLE;
1448         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
1449 
1450         if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
1451             hfp_connection->release_audio_connection = 1;
1452         }
1453 
1454         hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_TERMINATED);
1455         hfp_ag_run_for_context(hfp_connection);
1456         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
1457     }
1458 }
1459 
1460 static void hfp_ag_set_call_indicator(void){
1461     hfp_ag_indicator_t * indicator = get_ag_indicator_for_name("call");
1462     if (!indicator){
1463         log_error("hfp_ag_set_call_state: call indicator is missing");
1464         return;
1465     };
1466     indicator->status = hfp_gsm_call_status();
1467 }
1468 
1469 static hfp_connection_t * hfp_ag_connection_for_call_state(hfp_call_state_t call_state){
1470     btstack_linked_list_iterator_t it;
1471     btstack_linked_list_iterator_init(&it, hfp_get_connections());
1472     while (btstack_linked_list_iterator_has_next(&it)){
1473         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
1474         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
1475         if (hfp_connection->call_state == call_state) return hfp_connection;
1476     }
1477     return NULL;
1478 }
1479 
1480 static void hfp_ag_send_response_and_hold_state(hfp_response_and_hold_state_t 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         hfp_connection->send_response_and_hold_status = state + 1;
1487     }
1488 }
1489 
1490 static int call_setup_state_machine(hfp_connection_t * hfp_connection){
1491     int indicator_index;
1492     switch (hfp_connection->call_state){
1493         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING:
1494             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1495             // we got event: audio hfp_connection established
1496             hfp_connection->call_state = HFP_CALL_INCOMING_RINGING;
1497             break;
1498         case HFP_CALL_W4_AUDIO_CONNECTION_FOR_ACTIVE:
1499             if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED) return 0;
1500             // we got event: audio hfp_connection established
1501             hfp_connection->call_state = HFP_CALL_ACTIVE;
1502             break;
1503         case HFP_CALL_W2_SEND_CALL_WAITING:
1504             hfp_connection->call_state = HFP_CALL_W4_CHLD;
1505             hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
1506             indicator_index = get_ag_indicator_index_for_name("callsetup");
1507             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
1508             break;
1509         default:
1510             break;
1511     }
1512     return 0;
1513 }
1514 
1515 // functions extracted from hfp_ag_call_sm below
1516 static void hfp_ag_handle_reject_outgoing_call(void){
1517     hfp_connection_t * hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1518     if (!hfp_connection){
1519         log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1520         return;
1521     }
1522 
1523     hfp_gsm_handler(HFP_AG_OUTGOING_CALL_REJECTED, 0, 0, NULL);
1524     hfp_connection->call_state = HFP_CALL_IDLE;
1525     hfp_connection->send_error = 1;
1526     hfp_ag_run_for_context(hfp_connection);
1527 }
1528 
1529 // hfp_connection is used to identify originating HF
1530 static void hfp_ag_call_sm(hfp_ag_call_event_t event, hfp_connection_t * hfp_connection){
1531 
1532     // allow to intercept call statemachine events
1533     if (hfp_ag_custom_call_sm_handler != NULL){
1534         bool handle_event = (*hfp_ag_custom_call_sm_handler)(event);
1535         if (!handle_event) return;
1536     }
1537 
1538     int callsetup_indicator_index = get_ag_indicator_index_for_name("callsetup");
1539     int callheld_indicator_index = get_ag_indicator_index_for_name("callheld");
1540     int call_indicator_index = get_ag_indicator_index_for_name("call");
1541 
1542     switch (event){
1543         case HFP_AG_INCOMING_CALL:
1544             switch (hfp_gsm_call_status()){
1545                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1546                     switch (hfp_gsm_callsetup_status()){
1547                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1548                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1549                             hfp_ag_set_callsetup_indicator();
1550                             hfp_ag_trigger_incoming_call_idle();
1551                             log_info("AG rings");
1552                             break;
1553                         default:
1554                             break;
1555                     }
1556                     break;
1557                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1558                     switch (hfp_gsm_callsetup_status()){
1559                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1560                             hfp_gsm_handler(HFP_AG_INCOMING_CALL, 0, 0, NULL);
1561                             hfp_ag_set_callsetup_indicator();
1562                             hfp_ag_trigger_incoming_call_during_active_one();
1563                             log_info("AG call waiting");
1564                             break;
1565                         default:
1566                             break;
1567                     }
1568                     break;
1569                 default:
1570                     break;
1571             }
1572             break;
1573         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG:
1574             switch (hfp_gsm_call_status()){
1575                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1576                     switch (hfp_gsm_callsetup_status()){
1577                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1578                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1579                             hfp_ag_set_call_indicator();
1580                             hfp_ag_set_callsetup_indicator();
1581                             hfp_ag_ag_accept_call();
1582                             log_info("AG answers call, accept call by GSM");
1583                             break;
1584                         default:
1585                             break;
1586                     }
1587                     break;
1588                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1589                     switch (hfp_gsm_callsetup_status()){
1590                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1591                             log_info("AG: current call is placed on hold, incoming call gets active");
1592                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, 0, 0, NULL);
1593                             hfp_ag_set_callsetup_indicator();
1594                             hfp_ag_set_callheld_indicator();
1595                             hfp_ag_transfer_callsetup_state();
1596                             hfp_ag_transfer_callheld_state();
1597                             break;
1598                         default:
1599                             break;
1600                     }
1601                     break;
1602                 default:
1603                     break;
1604             }
1605             break;
1606 
1607         case HFP_AG_HELD_CALL_JOINED_BY_AG:
1608             switch (hfp_gsm_call_status()){
1609                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1610                     switch (hfp_gsm_callheld_status()){
1611                         case HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED:
1612                             log_info("AG: joining held call with active call");
1613                             hfp_gsm_handler(HFP_AG_HELD_CALL_JOINED_BY_AG, 0, 0, NULL);
1614                             hfp_ag_set_callheld_indicator();
1615                             hfp_ag_transfer_callheld_state();
1616                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
1617                             break;
1618                         default:
1619                             break;
1620                     }
1621                     break;
1622                 default:
1623                     break;
1624             }
1625             break;
1626 
1627         case HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF:
1628             switch (hfp_gsm_call_status()){
1629                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1630                     switch (hfp_gsm_callsetup_status()){
1631                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1632                             hfp_gsm_handler(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, 0, 0, NULL);
1633                             hfp_ag_set_callsetup_indicator();
1634                             hfp_ag_set_call_indicator();
1635                             hfp_ag_hf_accept_call(hfp_connection);
1636                             hfp_connection->ok_pending = 1;
1637                             log_info("HF answers call, accept call by GSM");
1638                             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1639                             break;
1640                         default:
1641                             break;
1642                     }
1643                     break;
1644                 default:
1645                     break;
1646             }
1647             break;
1648 
1649         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG:
1650             switch (hfp_gsm_call_status()){
1651                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1652                     switch (hfp_gsm_callsetup_status()){
1653                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1654                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, 0, 0, NULL);
1655                             hfp_ag_response_and_hold_active = true;
1656                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1657                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1658                             // as with regular call
1659                             hfp_ag_set_call_indicator();
1660                             hfp_ag_set_callsetup_indicator();
1661                             hfp_ag_ag_accept_call();
1662                             log_info("AG response and hold - hold by AG");
1663                             break;
1664                         default:
1665                             break;
1666                     }
1667                     break;
1668                 default:
1669                     break;
1670             }
1671             break;
1672 
1673         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF:
1674             switch (hfp_gsm_call_status()){
1675                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1676                     switch (hfp_gsm_callsetup_status()){
1677                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1678                             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, 0, 0, NULL);
1679                             hfp_ag_response_and_hold_active = true;
1680                             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
1681                             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1682                             // as with regular call
1683                             hfp_ag_set_call_indicator();
1684                             hfp_ag_set_callsetup_indicator();
1685                             hfp_ag_hf_accept_call(hfp_connection);
1686                             log_info("AG response and hold - hold by HF");
1687                             break;
1688                         default:
1689                             break;
1690                     }
1691                     break;
1692                 default:
1693                     break;
1694             }
1695             break;
1696 
1697         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG:
1698         case HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF:
1699             if (!hfp_ag_response_and_hold_active) break;
1700             if (hfp_ag_response_and_hold_state != HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD) break;
1701             hfp_gsm_handler(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, 0, 0, NULL);
1702             hfp_ag_response_and_hold_active = false;
1703             hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED;
1704             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1705             log_info("Held Call accepted and active");
1706             break;
1707 
1708         case HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG:
1709         case HFP_AG_RESPONSE_AND_HOLD_REJECT_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_REJECT_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_REJECTED;
1715             hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1716             // from terminate by ag
1717             hfp_ag_set_call_indicator();
1718             hfp_ag_trigger_terminate_call();
1719             break;
1720 
1721         case HFP_AG_TERMINATE_CALL_BY_HF:
1722             switch (hfp_gsm_call_status()){
1723                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1724                     switch (hfp_gsm_callsetup_status()){
1725                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1726                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1727                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1728                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1729                             hfp_ag_set_callsetup_indicator();
1730                             hfp_ag_transfer_callsetup_state();
1731                             hfp_ag_trigger_reject_call();
1732                             log_info("HF Rejected Incoming call, AG terminate call");
1733                             break;
1734                         default:
1735                             break;
1736                     }
1737                     break;
1738                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1739                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_HF, 0, 0, NULL);
1740                     hfp_ag_set_callsetup_indicator();
1741                     hfp_ag_set_call_indicator();
1742                     hfp_ag_trigger_terminate_call();
1743                     log_info("AG terminate call");
1744                     break;
1745                 default:
1746                     break;
1747             }
1748             break;
1749 
1750         case HFP_AG_TERMINATE_CALL_BY_AG:
1751             switch (hfp_gsm_call_status()){
1752                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1753                     switch (hfp_gsm_callsetup_status()){
1754                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1755                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1756                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1757                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1758                             hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1759                             hfp_ag_set_callsetup_indicator();
1760                             hfp_ag_trigger_reject_call();
1761                             log_info("AG Rejected Incoming call, AG terminate call");
1762                             break;
1763                         default:
1764                             break;
1765                     }
1766                     break;
1767                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1768                     hfp_gsm_handler(HFP_AG_TERMINATE_CALL_BY_AG, 0, 0, NULL);
1769                     hfp_ag_set_callsetup_indicator();
1770                     hfp_ag_set_call_indicator();
1771                     hfp_ag_trigger_terminate_call();
1772                     log_info("AG terminate call");
1773                     break;
1774                 default:
1775                     break;
1776             }
1777             break;
1778         case HFP_AG_CALL_DROPPED:
1779             switch (hfp_gsm_call_status()){
1780                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1781                     switch (hfp_gsm_callsetup_status()){
1782                         case HFP_CALLSETUP_STATUS_INCOMING_CALL_SETUP_IN_PROGRESS:
1783                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_ALERTING_STATE:
1784                             hfp_ag_stop_ringing();
1785                             break;
1786                         case HFP_CALLSETUP_STATUS_OUTGOING_CALL_SETUP_IN_DIALING_STATE:
1787                             log_info("Outgoing call interrupted\n");
1788                             break;
1789                         default:
1790                             break;
1791                     }
1792                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1793                     hfp_ag_set_callsetup_indicator();
1794                     hfp_ag_transfer_callsetup_state();
1795                     hfp_ag_trigger_terminate_call();
1796                     break;
1797                 case HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT:
1798                     if (hfp_ag_response_and_hold_active) {
1799                         hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1800                         hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED;
1801                         hfp_ag_send_response_and_hold_state(hfp_ag_response_and_hold_state);
1802                     }
1803                     hfp_gsm_handler(HFP_AG_CALL_DROPPED, 0, 0, NULL);
1804                     hfp_ag_set_callsetup_indicator();
1805                     hfp_ag_set_call_indicator();
1806                     hfp_ag_trigger_terminate_call();
1807                     log_info("AG notify call dropped");
1808                     break;
1809                 default:
1810                     break;
1811             }
1812             break;
1813 
1814         case HFP_AG_OUTGOING_CALL_INITIATED_BY_HF:
1815             // directly reject call if number of free slots is exceeded
1816             if (!hfp_gsm_call_possible()){
1817                 hfp_connection->send_error = 1;
1818                 hfp_ag_run_for_context(hfp_connection);
1819                 break;
1820             }
1821 
1822             // note: number not used currently
1823             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, 0, 0, (const char *) &hfp_connection->line_buffer[3]);
1824 
1825             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1826 
1827             hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, (const char *) &hfp_connection->line_buffer[3]);
1828             break;
1829 
1830         case HFP_AG_OUTGOING_CALL_INITIATED_BY_AG:
1831             // directly reject call if number of free slots is exceeded
1832             if (!hfp_gsm_call_possible()) {
1833                 // TODO: no error for user
1834                 break;
1835             }
1836             switch (hfp_gsm_call_status()) {
1837                 case HFP_CALL_STATUS_NO_HELD_OR_ACTIVE_CALLS:
1838                     switch (hfp_gsm_callsetup_status()) {
1839                         case HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS:
1840                             // note: number not used currently
1841                             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, 0, 0, "1234567");
1842                             // init call state for all connections
1843                             hfp_ag_trigger_outgoing_call();
1844                             // get first one and accept call
1845                             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1846                             if (hfp_connection) {
1847                                 hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1848                             }
1849                             break;
1850                         default:
1851                             // TODO: no error for user
1852                             break;
1853                     }
1854                     break;
1855                 default:
1856                     // TODO: no error for user
1857                     break;
1858             }
1859             break;
1860         case HFP_AG_OUTGOING_REDIAL_INITIATED:{
1861             // directly reject call if number of free slots is exceeded
1862             if (!hfp_gsm_call_possible()){
1863                 hfp_connection->send_error = 1;
1864                 hfp_ag_run_for_context(hfp_connection);
1865                 break;
1866             }
1867 
1868             hfp_gsm_handler(HFP_AG_OUTGOING_REDIAL_INITIATED, 0, 0, NULL);
1869             hfp_connection->call_state = HFP_CALL_OUTGOING_INITIATED;
1870 
1871             log_info("Redial last number");
1872             char * last_dialed_number = hfp_gsm_last_dialed_number();
1873 
1874             if (strlen(last_dialed_number) > 0){
1875                 log_info("Last number exists: accept call");
1876                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER, last_dialed_number);
1877             } else {
1878                 log_info("log_infoLast number missing: reject call");
1879                 hfp_ag_handle_reject_outgoing_call();
1880             }
1881             break;
1882         }
1883         case HFP_AG_OUTGOING_CALL_REJECTED:
1884             hfp_ag_handle_reject_outgoing_call();
1885             break;
1886 
1887         case HFP_AG_OUTGOING_CALL_ACCEPTED:{
1888             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_INITIATED);
1889             if (!hfp_connection){
1890                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in initiated state");
1891                 break;
1892             }
1893 
1894             hfp_connection->ok_pending = 1;
1895             hfp_ag_handle_outgoing_call_accepted(hfp_connection);
1896             break;
1897         }
1898         case HFP_AG_OUTGOING_CALL_RINGING:
1899             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1900             if (!hfp_connection){
1901                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection in dialing state");
1902                 break;
1903             }
1904 
1905             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_RINGING, 0, 0, NULL);
1906             hfp_connection->call_state = HFP_CALL_OUTGOING_RINGING;
1907             hfp_ag_set_callsetup_indicator();
1908             hfp_ag_transfer_callsetup_state();
1909             hfp_ag_hf_start_ringing_outgoing(hfp_connection);
1910             break;
1911 
1912         case HFP_AG_OUTGOING_CALL_ESTABLISHED:{
1913             // get outgoing call
1914             hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_RINGING);
1915             if (!hfp_connection){
1916                 hfp_connection = hfp_ag_connection_for_call_state(HFP_CALL_OUTGOING_DIALING);
1917             }
1918             if (!hfp_connection){
1919                 log_info("hfp_ag_call_sm: did not find outgoing hfp_connection");
1920                 break;
1921             }
1922 
1923             bool callheld_status_call_on_hold_and_no_active_calls = hfp_gsm_callheld_status() == HFP_CALLHELD_STATUS_CALL_ON_HOLD_AND_NO_ACTIVE_CALLS;
1924             hfp_gsm_handler(HFP_AG_OUTGOING_CALL_ESTABLISHED, 0, 0, NULL);
1925             hfp_connection->call_state = HFP_CALL_ACTIVE;
1926             hfp_ag_set_callsetup_indicator();
1927             hfp_ag_set_call_indicator();
1928             hfp_ag_transfer_call_state();
1929             hfp_ag_transfer_callsetup_state();
1930             if (callheld_status_call_on_hold_and_no_active_calls){
1931                 hfp_ag_set_callheld_indicator();
1932                 hfp_ag_transfer_callheld_state();
1933             }
1934             hfp_ag_hf_stop_ringing(hfp_connection);
1935             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CALL_ANSWERED);
1936             break;
1937         }
1938 
1939         case HFP_AG_CALL_HOLD_USER_BUSY:
1940             hfp_gsm_handler(HFP_AG_CALL_HOLD_USER_BUSY, 0, 0, NULL);
1941             hfp_ag_set_callsetup_indicator();
1942             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1943             hfp_connection->call_state = HFP_CALL_ACTIVE;
1944             log_info("AG: Call Waiting, User Busy");
1945             break;
1946 
1947         case HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1948             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1949             int call_held = hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD;
1950 
1951             // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
1952             if (call_held || call_setup_in_progress){
1953                 hfp_gsm_handler(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index,
1954                                 0, NULL);
1955 
1956             }
1957 
1958             if (call_setup_in_progress){
1959                 log_info("AG: Call Dropped, Accept new call");
1960                 hfp_ag_set_callsetup_indicator();
1961                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1962             } else {
1963                 log_info("AG: Call Dropped, Resume held call");
1964             }
1965             if (call_held){
1966                 hfp_ag_set_callheld_indicator();
1967                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1968             }
1969 
1970             hfp_connection->call_state = HFP_CALL_ACTIVE;
1971             break;
1972         }
1973 
1974         case HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL:{
1975             // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
1976             // only update if callsetup changed
1977             int call_setup_in_progress = hfp_gsm_callsetup_status() != HFP_CALLSETUP_STATUS_NO_CALL_SETUP_IN_PROGRESS;
1978             hfp_gsm_handler(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection->call_index, 0,
1979                             NULL);
1980 
1981             if (call_setup_in_progress){
1982                 log_info("AG: Call on Hold, Accept new call");
1983                 hfp_ag_set_callsetup_indicator();
1984                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callsetup_indicator_index, 1);
1985             } else {
1986                 log_info("AG: Swap calls");
1987             }
1988 
1989             hfp_ag_set_callheld_indicator();
1990             // hfp_ag_set_callheld_state(HFP_CALLHELD_STATUS_CALL_ON_HOLD_OR_SWAPPED);
1991             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
1992             hfp_connection->call_state = HFP_CALL_ACTIVE;
1993             break;
1994         }
1995 
1996         case HFP_AG_CALL_HOLD_ADD_HELD_CALL:
1997             // Adds a held call to the conversation.
1998             if (hfp_gsm_callheld_status() != HFP_CALLHELD_STATUS_NO_CALLS_HELD){
1999                 log_info("AG: Join 3-way-call");
2000                 hfp_gsm_handler(HFP_AG_CALL_HOLD_ADD_HELD_CALL, 0, 0, NULL);
2001                 hfp_ag_set_callheld_indicator();
2002                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
2003                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_CONFERENCE_CALL);
2004             }
2005             hfp_connection->call_state = HFP_CALL_ACTIVE;
2006             break;
2007         case HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS:
2008             // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer)
2009             hfp_gsm_handler(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, 0, 0, NULL);
2010             log_info("AG: Transfer call -> Connect two calls and disconnect");
2011             hfp_ag_set_call_indicator();
2012             hfp_ag_set_callheld_indicator();
2013             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, call_indicator_index, 1);
2014             hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, callheld_indicator_index, 1);
2015             hfp_connection->call_state = HFP_CALL_IDLE;
2016             break;
2017 
2018         default:
2019             break;
2020     }
2021 
2022 
2023 }
2024 
2025 
2026 static void hfp_ag_send_call_status(hfp_connection_t * hfp_connection, int call_index){
2027     hfp_gsm_call_t * active_call = hfp_gsm_call(call_index);
2028     if (!active_call) return;
2029 
2030     int idx = active_call->index;
2031     hfp_enhanced_call_dir_t dir = active_call->direction;
2032     hfp_enhanced_call_status_t status = active_call->enhanced_status;
2033     hfp_enhanced_call_mode_t mode = active_call->mode;
2034     hfp_enhanced_call_mpty_t mpty = active_call->mpty;
2035     uint8_t type = active_call->clip_type;
2036     char * number = active_call->clip_number;
2037 
2038     char buffer[100];
2039     // TODO: check length of a buffer, to fit the MTU
2040     int offset = snprintf(buffer, sizeof(buffer), "\r\n%s: %d,%d,%d,%d,%d", HFP_LIST_CURRENT_CALLS, idx, dir, status, mode, mpty);
2041     if (number){
2042         offset += snprintf(buffer+offset, sizeof(buffer)-offset-3, ", \"%s\",%u", number, type);
2043     }
2044     snprintf(buffer+offset, sizeof(buffer)-offset, "\r\n");
2045     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,
2046        mode, mpty, type, number);
2047     send_str_over_rfcomm(hfp_connection->rfcomm_cid, buffer);
2048 }
2049 
2050 // sends pending command, returns if command was sent
2051 static int hfp_ag_send_commands(hfp_connection_t *hfp_connection){
2052     if (hfp_connection->send_status_of_current_calls){
2053         hfp_connection->ok_pending = 0;
2054         if (hfp_connection->next_call_index < hfp_gsm_get_number_of_calls()){
2055             hfp_connection->next_call_index++;
2056             hfp_ag_send_call_status(hfp_connection, hfp_connection->next_call_index);
2057             return 1;
2058         } else {
2059             // 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
2060             hfp_connection->next_call_index = 0;
2061             hfp_connection->ok_pending = 1;
2062             hfp_connection->send_status_of_current_calls = 0;
2063         }
2064     }
2065 
2066     if (hfp_connection->ag_notify_incoming_call_waiting){
2067         hfp_connection->ag_notify_incoming_call_waiting = 0;
2068         hfp_ag_send_call_waiting_notification(hfp_connection->rfcomm_cid);
2069         return 1;
2070     }
2071 
2072     if (hfp_connection->send_error){
2073         hfp_connection->send_error = 0;
2074         hfp_connection->command = HFP_CMD_NONE;
2075         hfp_ag_send_error(hfp_connection->rfcomm_cid);
2076         return 1;
2077     }
2078 
2079     // note: before update AG indicators and ok_pending
2080     if (hfp_connection->send_response_and_hold_status){
2081         int status = hfp_connection->send_response_and_hold_status - 1;
2082         hfp_connection->send_response_and_hold_status = 0;
2083         hfp_ag_send_set_response_and_hold(hfp_connection->rfcomm_cid, status);
2084         return 1;
2085     }
2086 
2087     // note: before ok_pending and send_error to allow for unsolicited result on custom command
2088     if (hfp_connection->send_custom_message != NULL){
2089         const char * message = hfp_connection->send_custom_message;
2090         hfp_connection->send_custom_message = NULL;
2091         send_str_over_rfcomm(hfp_connection->rfcomm_cid, message);
2092         hfp_emit_event(hfp_connection, HFP_SUBEVENT_COMPLETE, ERROR_CODE_SUCCESS);
2093         return 1;
2094     }
2095 
2096     if (hfp_connection->ok_pending){
2097         hfp_connection->ok_pending = 0;
2098         hfp_connection->command = HFP_CMD_NONE;
2099         hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2100         return 1;
2101     }
2102 
2103     // update AG indicators only if enabled by AT+CMER=3,0,0,1
2104     if ((hfp_connection->enable_status_update_for_ag_indicators == 1) && (hfp_connection->ag_indicators_status_update_bitmap != 0)){
2105         uint16_t i;
2106         for (i=0;i<hfp_connection->ag_indicators_nr;i++){
2107             if (get_bit(hfp_connection->ag_indicators_status_update_bitmap, i)){
2108                 hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, i, 0);
2109                 hfp_ag_send_transfer_ag_indicators_status_cmd(hfp_connection->rfcomm_cid, &hfp_ag_indicators[i]);
2110                 return 1;
2111             }
2112         }
2113     }
2114 
2115     if (hfp_connection->ag_send_no_carrier){
2116         hfp_connection->ag_send_no_carrier = false;
2117         hfp_ag_send_no_carrier(hfp_connection->rfcomm_cid);
2118         return 1;
2119     }
2120 
2121     if (hfp_connection->send_phone_number_for_voice_tag){
2122         hfp_connection->send_phone_number_for_voice_tag = 0;
2123         hfp_connection->command = HFP_CMD_NONE;
2124         hfp_connection->ok_pending = 1;
2125         hfp_ag_send_phone_number_for_voice_tag_cmd(hfp_connection->rfcomm_cid);
2126         return 1;
2127     }
2128 
2129     if (hfp_connection->send_subscriber_number){
2130         if (hfp_connection->next_subscriber_number_to_send < hfp_ag_subscriber_numbers_count){
2131             hfp_phone_number_t phone = hfp_ag_subscriber_numbers[hfp_connection->next_subscriber_number_to_send++];
2132             hfp_send_subscriber_number_cmd(hfp_connection->rfcomm_cid, phone.type, phone.number);
2133         } else {
2134             hfp_connection->send_subscriber_number = 0;
2135             hfp_connection->next_subscriber_number_to_send = 0;
2136             hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2137         }
2138         hfp_connection->command = HFP_CMD_NONE;
2139         return 1;
2140     }
2141 
2142     if (hfp_connection->send_microphone_gain){
2143         hfp_connection->send_microphone_gain = 0;
2144         hfp_connection->command = HFP_CMD_NONE;
2145         hfp_ag_send_set_microphone_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->microphone_gain);
2146         return 1;
2147     }
2148 
2149     if (hfp_connection->send_speaker_gain){
2150         hfp_connection->send_speaker_gain = 0;
2151         hfp_connection->command = HFP_CMD_NONE;
2152         hfp_ag_send_set_speaker_gain_cmd(hfp_connection->rfcomm_cid, hfp_connection->speaker_gain);
2153         return 1;
2154     }
2155 
2156     if (hfp_connection->send_ag_status_indicators){
2157         hfp_connection->send_ag_status_indicators = 0;
2158         hfp_ag_send_retrieve_indicators_status_cmd(hfp_connection->rfcomm_cid);
2159         return 1;
2160     }
2161 
2162     return 0;
2163 }
2164 
2165 // sends pending command, returns if command was sent
2166 static int hfp_ag_run_ring_and_clip(hfp_connection_t *hfp_connection){
2167     // delay RING/CLIP until audio connection has been established for incoming calls
2168     // hfp_ag_hf_trigger_ring_and_clip is called in call_setup_state_machine
2169     if (hfp_connection->call_state != HFP_CALL_W4_AUDIO_CONNECTION_FOR_IN_BAND_RING){
2170         if (hfp_connection->ag_ring){
2171             hfp_connection->ag_ring = 0;
2172             hfp_connection->command = HFP_CMD_NONE;
2173             hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_RING);
2174             hfp_ag_send_ring(hfp_connection->rfcomm_cid);
2175             return 1;
2176         }
2177 
2178         if (hfp_connection->ag_send_clip){
2179             hfp_connection->ag_send_clip = 0;
2180             hfp_connection->command = HFP_CMD_NONE;
2181             hfp_ag_send_clip(hfp_connection->rfcomm_cid);
2182             return 1;
2183         }
2184     }
2185     return 0;
2186 }
2187 
2188 static void hfp_ag_run_for_context(hfp_connection_t *hfp_connection){
2189 
2190 	btstack_assert(hfp_connection != NULL);
2191 	btstack_assert(hfp_connection->local_role == HFP_ROLE_AG);
2192 
2193 	// during SDP query, RFCOMM CID is not set
2194 	if (hfp_connection->rfcomm_cid == 0) return;
2195 
2196     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED && hfp_connection->emit_vra_enabled_after_audio_established){
2197         hfp_connection->emit_vra_enabled_after_audio_established = false;
2198         hfp_emit_voice_recognition_enabled(hfp_connection, ERROR_CODE_SUCCESS);
2199     }
2200 
2201     if ((hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED) && hfp_connection->release_audio_connection){
2202         hfp_connection->state = HFP_W4_SCO_DISCONNECTED;
2203         hfp_connection->release_audio_connection = 0;
2204         gap_disconnect(hfp_connection->sco_handle);
2205         return;
2206     }
2207 
2208     // configure NBS/WBS if needed using vendor-specific HCI commands
2209     if (hci_can_send_command_packet_now()) {
2210 #ifdef ENABLE_CC256X_ASSISTED_HFP
2211         // WBS Disassociate
2212         if (hfp_connection->cc256x_send_wbs_disassociate){
2213             hfp_connection->cc256x_send_wbs_disassociate = false;
2214             hci_send_cmd(&hci_ti_wbs_disassociate);
2215             return;
2216         }
2217         // Write Codec Config
2218         if (hfp_connection->cc256x_send_write_codec_config){
2219             hfp_connection->cc256x_send_write_codec_config = false;
2220             hfp_cc256x_write_codec_config(hfp_connection);
2221             return;
2222         }
2223         // WBS Associate
2224         if (hfp_connection->cc256x_send_wbs_associate){
2225             hfp_connection->cc256x_send_wbs_associate = false;
2226             hci_send_cmd(&hci_ti_wbs_associate, hfp_connection->acl_handle);
2227             return;
2228         }
2229 #endif
2230 #ifdef ENABLE_BCM_PCM_WBS
2231         // Enable WBS
2232         if (hfp_connection->bcm_send_enable_wbs){
2233             hfp_connection->bcm_send_enable_wbs = false;
2234             hci_send_cmd(&hci_bcm_enable_wbs, 1, 2);
2235             return;
2236         }
2237         // Write I2S/PCM params
2238         if (hfp_connection->bcm_send_write_i2spcm_interface_param){
2239             hfp_connection->bcm_send_write_i2spcm_interface_param = false;
2240             hfp_bcm_write_i2spcm_interface_param(hfp_connection);
2241             return;
2242         }
2243         // Disable WBS
2244         if (hfp_connection->bcm_send_disable_wbs){
2245             hfp_connection->bcm_send_disable_wbs = false;
2246             hci_send_cmd(&hci_bcm_enable_wbs, 0, 2);
2247             return;
2248         }
2249 #endif
2250 #ifdef ENABLE_RTK_PCM_WBS
2251         // Configure CVSD vs. mSBC
2252         if (hfp_connection->rtk_send_sco_config){
2253             hfp_connection->rtk_send_sco_config = false;
2254             if (hfp_connection->negotiated_codec == HFP_CODEC_MSBC){
2255                 log_info("RTK SCO: 16k + mSBC");
2256                 hci_send_cmd(&hci_rtk_configure_sco_routing, 0x81, 0x90, 0x00, 0x00, 0x1a, 0x0c, 0x00, 0x00, 0x41);
2257             } else {
2258                 log_info("RTK SCO: 16k + CVSD");
2259                 hci_send_cmd(&hci_rtk_configure_sco_routing, 0x81, 0x90, 0x00, 0x00, 0x1a, 0x0c, 0x0c, 0x00, 0x01);
2260             }
2261             return;
2262         }
2263 #endif
2264     }
2265 
2266 #if defined (ENABLE_CC256X_ASSISTED_HFP) || defined (ENABLE_BCM_PCM_WBS)
2267     if (hfp_connection->state == HFP_W4_WBS_SHUTDOWN){
2268         hfp_finalize_connection_context(hfp_connection);
2269         return;
2270     }
2271 #endif
2272 
2273     if (!rfcomm_can_send_packet_now(hfp_connection->rfcomm_cid)) {
2274         log_info("hfp_ag_run_for_context: request can send for 0x%02x", hfp_connection->rfcomm_cid);
2275         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2276         return;
2277     }
2278 
2279     int cmd_sent = hfp_ag_send_commands(hfp_connection);
2280 
2281     if (!cmd_sent){
2282         cmd_sent = hfp_ag_run_for_context_service_level_connection(hfp_connection);
2283     }
2284 
2285     if (!cmd_sent){
2286         cmd_sent = hfp_ag_run_for_context_service_level_connection_queries(hfp_connection);
2287     }
2288 
2289     if (!cmd_sent){
2290         cmd_sent = call_setup_state_machine(hfp_connection);
2291     }
2292 
2293     if (!cmd_sent){
2294         cmd_sent = hfp_ag_run_for_audio_connection(hfp_connection);
2295     }
2296 
2297     if (!cmd_sent){
2298         cmd_sent = hfp_ag_run_ring_and_clip(hfp_connection);
2299     }
2300 
2301     if (!cmd_sent){
2302         cmd_sent = hfp_ag_voice_recognition_state_machine(hfp_connection);
2303     }
2304 
2305     // disconnect
2306     if (!cmd_sent && (hfp_connection->command == HFP_CMD_NONE) && (hfp_connection->state == HFP_W2_DISCONNECT_RFCOMM)){
2307         hfp_connection->state = HFP_W4_RFCOMM_DISCONNECTED;
2308         rfcomm_disconnect(hfp_connection->rfcomm_cid);
2309     }
2310 
2311     if (cmd_sent){
2312         hfp_connection->command = HFP_CMD_NONE;
2313         rfcomm_request_can_send_now_event(hfp_connection->rfcomm_cid);
2314     }
2315 }
2316 
2317 static int hfp_parser_is_end_of_line(uint8_t byte){
2318     return (byte == '\n') || (byte == '\r');
2319 }
2320 
2321 static void hfp_ag_handle_rfcomm_data(hfp_connection_t * hfp_connection, uint8_t *packet, uint16_t size){
2322     // assertion: size >= 1 as rfcomm.c does not deliver empty packets
2323     if (size < 1) return;
2324     uint8_t status = ERROR_CODE_SUCCESS;
2325 
2326     hfp_log_rfcomm_message("HFP_AG_RX", packet, size);
2327 #ifdef ENABLE_HFP_AT_MESSAGES
2328     hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_AT_MESSAGE_RECEIVED, (char *) packet);
2329 #endif
2330 
2331     // process messages byte-wise
2332     int pos;
2333     for (pos = 0; pos < size ; pos++){
2334         hfp_parse(hfp_connection, packet[pos], 0);
2335 
2336         // parse until end of line
2337         if (!hfp_parser_is_end_of_line(packet[pos])) continue;
2338 
2339         hfp_generic_status_indicator_t * indicator;
2340         switch(hfp_connection->command){
2341             case HFP_CMD_HF_ACTIVATE_VOICE_RECOGNITION:
2342                 hfp_connection->command = HFP_CMD_NONE;
2343                 hfp_connection->ag_vra_requested_by_hf = true;
2344                 break;
2345             case HFP_CMD_RESPONSE_AND_HOLD_QUERY:
2346                 hfp_connection->command = HFP_CMD_NONE;
2347                 if (hfp_ag_response_and_hold_active){
2348                     hfp_connection->send_response_and_hold_status = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD + 1;
2349                 }
2350                 hfp_connection->ok_pending = 1;
2351                 break;
2352             case HFP_CMD_RESPONSE_AND_HOLD_COMMAND:
2353                 hfp_connection->command = HFP_CMD_NONE;
2354                 switch(hfp_connection->ag_response_and_hold_action){
2355                     case HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD:
2356                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_HF, hfp_connection);
2357                         break;
2358                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_ACCEPTED:
2359                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_HF, hfp_connection);
2360                         break;
2361                     case HFP_RESPONSE_AND_HOLD_HELD_INCOMING_REJECTED:
2362                         hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_HF, hfp_connection);
2363                         break;
2364                     default:
2365                         break;
2366                 }
2367                 hfp_connection->ok_pending = 1;
2368                 break;
2369             case HFP_CMD_HF_INDICATOR_STATUS:
2370                 hfp_connection->command = HFP_CMD_NONE;
2371 
2372                 if (hfp_connection->parser_indicator_index < hfp_ag_generic_status_indicators_nr){
2373                     indicator = &hfp_ag_generic_status_indicators[hfp_connection->parser_indicator_index];
2374                     switch (indicator->uuid){
2375                         case HFP_HF_INDICATOR_UUID_ENHANCED_SAFETY:
2376                             if (hfp_connection->parser_indicator_value > 1) {
2377                                 hfp_connection->send_error = 1;
2378                                 break;
2379                             }
2380                             hfp_connection->ok_pending = 1;
2381                             hfp_ag_emit_hf_indicator_value(hfp_connection, indicator->uuid, hfp_connection->parser_indicator_value);
2382                             break;
2383                         case HFP_HF_INDICATOR_UUID_BATTERY_LEVEL:
2384                             if (hfp_connection->parser_indicator_value > 100){
2385                                 hfp_connection->send_error = 1;
2386                                 break;
2387                             }
2388                             hfp_connection->ok_pending = 1;
2389                             hfp_ag_emit_hf_indicator_value(hfp_connection, indicator->uuid, hfp_connection->parser_indicator_value);
2390                             break;
2391                         default:
2392                             hfp_connection->send_error = 1;
2393                             break;
2394                     }
2395                 } else {
2396                     hfp_connection->send_error = 1;
2397                 }
2398                 break;
2399             case HFP_CMD_RETRIEVE_AG_INDICATORS_STATUS:
2400                 // expected by SLC state machine
2401                 if (hfp_connection->state < HFP_SERVICE_LEVEL_CONNECTION_ESTABLISHED) break;
2402                 hfp_connection->send_ag_indicators_segment = 0;
2403                 hfp_connection->send_ag_status_indicators = 1;
2404                 break;
2405             case HFP_CMD_LIST_CURRENT_CALLS:
2406                 hfp_connection->command = HFP_CMD_NONE;
2407                 hfp_connection->next_call_index = 0;
2408                 hfp_connection->send_status_of_current_calls = 1;
2409                 break;
2410             case HFP_CMD_GET_SUBSCRIBER_NUMBER_INFORMATION:
2411                 hfp_connection->command = HFP_CMD_NONE;
2412                 if (hfp_ag_subscriber_numbers_count == 0){
2413                     hfp_ag_send_ok(hfp_connection->rfcomm_cid);
2414                     break;
2415                 }
2416                 hfp_connection->next_subscriber_number_to_send = 0;
2417                 hfp_connection->send_subscriber_number = 1;
2418                 break;
2419             case HFP_CMD_TRANSMIT_DTMF_CODES:
2420             {
2421                 hfp_connection->command = HFP_CMD_NONE;
2422                 char buffer[2];
2423                 buffer[0] = (char) hfp_connection->ag_dtmf_code;
2424                 buffer[1] = 0;
2425                 hfp_emit_string_event(hfp_connection, HFP_SUBEVENT_TRANSMIT_DTMF_CODES, buffer);
2426                 break;
2427             }
2428             case HFP_CMD_HF_REQUEST_PHONE_NUMBER:
2429                 hfp_connection->command = HFP_CMD_NONE;
2430                 hfp_emit_simple_event(hfp_connection, HFP_SUBEVENT_ATTACH_NUMBER_TO_VOICE_TAG);
2431                 break;
2432             case HFP_CMD_TURN_OFF_EC_AND_NR:
2433                 hfp_connection->command = HFP_CMD_NONE;
2434 
2435                 if (get_bit(hfp_ag_supported_features, HFP_AGSF_EC_NR_FUNCTION)){
2436                     hfp_connection->ok_pending = 1;
2437                     hfp_ag_supported_features = store_bit(hfp_ag_supported_features, HFP_AGSF_EC_NR_FUNCTION, hfp_connection->ag_echo_and_noise_reduction);
2438                     status = ERROR_CODE_SUCCESS;
2439                 } else {
2440                     hfp_connection->send_error = 1;
2441                     status = ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2442                 }
2443                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_ECHO_CANCELING_AND_NOISE_REDUCTION_DEACTIVATE, status);
2444                 break;
2445             case HFP_CMD_CALL_ANSWERED:
2446                 hfp_connection->command = HFP_CMD_NONE;
2447                 log_info("HFP: ATA");
2448                 hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_HF, hfp_connection);
2449                 break;
2450             case HFP_CMD_HANG_UP_CALL:
2451                 hfp_connection->command = HFP_CMD_NONE;
2452                 hfp_connection->ok_pending = 1;
2453                 hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_HF, hfp_connection);
2454                 break;
2455             case HFP_CMD_CALL_HOLD: {
2456                 hfp_connection->command = HFP_CMD_NONE;
2457                 hfp_connection->ok_pending = 1;
2458 
2459                 switch (hfp_connection->ag_call_hold_action){
2460                     case 0:
2461                         // Releases all held calls or sets User Determined User Busy (UDUB) for a waiting call.
2462                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_USER_BUSY, hfp_connection);
2463                         break;
2464                     case 1:
2465                         // Releases all active calls (if any exist) and accepts the other (held or waiting) call.
2466                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2467                         // waiting call (i.e., not to the held call) in conflicting situation.
2468                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_RELEASE_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2469                         break;
2470                     case 2:
2471                         // Places all active calls (if any exist) on hold and accepts the other (held or waiting) call.
2472                         // Where both a held and a waiting call exist, the above procedures shall apply to the
2473                         // waiting call (i.e., not to the held call) in conflicting situation.
2474                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_PARK_ACTIVE_ACCEPT_HELD_OR_WAITING_CALL, hfp_connection);
2475                         break;
2476                     case 3:
2477                         // Adds a held call to the conversation.
2478                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_ADD_HELD_CALL, hfp_connection);
2479                         break;
2480                     case 4:
2481                         // Connects the two calls and disconnects the subscriber from both calls (Explicit Call Transfer).
2482                         hfp_ag_call_sm(HFP_AG_CALL_HOLD_EXIT_AND_JOIN_CALLS, hfp_connection);
2483                         break;
2484                     default:
2485                         break;
2486                 }
2487 				hfp_connection->call_index = 0;
2488                 break;
2489             }
2490             case HFP_CMD_CALL_PHONE_NUMBER:
2491                 hfp_connection->command = HFP_CMD_NONE;
2492                 hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_HF, hfp_connection);
2493                 break;
2494             case HFP_CMD_REDIAL_LAST_NUMBER:
2495                 hfp_connection->command = HFP_CMD_NONE;
2496                 hfp_ag_call_sm(HFP_AG_OUTGOING_REDIAL_INITIATED, hfp_connection);
2497                 break;
2498             case HFP_CMD_ENABLE_CLIP:
2499                 hfp_connection->command = HFP_CMD_NONE;
2500                 log_info("hfp: clip set, now: %u", hfp_connection->clip_enabled);
2501                 hfp_connection->ok_pending = 1;
2502                 break;
2503             case HFP_CMD_ENABLE_CALL_WAITING_NOTIFICATION:
2504                 hfp_connection->command = HFP_CMD_NONE;
2505                 log_info("hfp: call waiting notification set, now: %u", hfp_connection->call_waiting_notification_enabled);
2506                 hfp_connection->ok_pending = 1;
2507                 break;
2508             case HFP_CMD_SET_SPEAKER_GAIN:
2509                 hfp_connection->command = HFP_CMD_NONE;
2510                 hfp_connection->ok_pending = 1;
2511                 log_info("HF speaker gain = %u", hfp_connection->speaker_gain);
2512                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_SPEAKER_VOLUME, hfp_connection->speaker_gain);
2513                 break;
2514             case HFP_CMD_SET_MICROPHONE_GAIN:
2515                 hfp_connection->command = HFP_CMD_NONE;
2516                 hfp_connection->ok_pending = 1;
2517                 log_info("HF microphone gain = %u", hfp_connection->microphone_gain);
2518                 hfp_emit_event(hfp_connection, HFP_SUBEVENT_MICROPHONE_VOLUME, hfp_connection->microphone_gain);
2519                 break;
2520             case HFP_CMD_CUSTOM_MESSAGE:
2521                 hfp_connection->command = HFP_CMD_NONE;
2522                 hfp_parser_reset_line_buffer(hfp_connection);
2523                 log_info("Custom AT Command ID 0x%04x", hfp_connection->ag_custom_at_command_id);
2524                 hfp_ag_emit_custom_command_event(hfp_connection);
2525                 break;
2526             case HFP_CMD_UNKNOWN:
2527                 hfp_connection->command = HFP_CMD_NONE;
2528                 hfp_connection->send_error = 1;
2529                 break;
2530             default:
2531                 break;
2532         }
2533     }
2534 }
2535 
2536 static void hfp_ag_run(void){
2537     btstack_linked_list_iterator_t it;
2538     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2539     while (btstack_linked_list_iterator_has_next(&it)){
2540         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2541         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2542         hfp_ag_run_for_context(hfp_connection);
2543     }
2544 }
2545 
2546 static void hfp_ag_rfcomm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2547     hfp_connection_t * hfp_connection = NULL;
2548     switch (packet_type){
2549         case RFCOMM_DATA_PACKET:
2550             hfp_connection = get_hfp_connection_context_for_rfcomm_cid(channel);
2551             btstack_assert(hfp_connection != NULL);
2552 
2553             hfp_ag_handle_rfcomm_data(hfp_connection, packet, size);
2554             hfp_ag_run_for_context(hfp_connection);
2555             return;
2556         case HCI_EVENT_PACKET:
2557             if (packet[0] == RFCOMM_EVENT_CAN_SEND_NOW){
2558                 uint16_t rfcomm_cid = rfcomm_event_can_send_now_get_rfcomm_cid(packet);
2559                 hfp_connection = get_hfp_connection_context_for_rfcomm_cid(rfcomm_cid);
2560                 btstack_assert(hfp_connection != NULL);
2561 
2562                 hfp_ag_run_for_context(hfp_connection);
2563                 return;
2564             }
2565             hfp_handle_rfcomm_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2566             break;
2567         default:
2568             break;
2569     }
2570 
2571     hfp_ag_run();
2572 }
2573 
2574 static void hfp_ag_hci_event_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
2575     hfp_handle_hci_event(packet_type, channel, packet, size, HFP_ROLE_AG);
2576     hfp_ag_run();
2577 }
2578 
2579 void hfp_ag_init_codecs(int codecs_nr, const uint8_t * codecs){
2580     if (codecs_nr > HFP_MAX_NUM_CODECS){
2581         log_error("hfp_init: codecs_nr (%d) > HFP_MAX_NUM_CODECS (%d)", codecs_nr, HFP_MAX_NUM_CODECS);
2582         return;
2583     }
2584     int i;
2585     hfp_ag_codecs_nr = codecs_nr;
2586     for (i=0; i < codecs_nr; i++){
2587         hfp_ag_codecs[i] = codecs[i];
2588     }
2589 }
2590 
2591 void hfp_ag_init_supported_features(uint32_t supported_features){
2592     hfp_ag_supported_features = supported_features;
2593 }
2594 
2595 void hfp_ag_init_ag_indicators(int ag_indicators_nr, const hfp_ag_indicator_t * ag_indicators){
2596     hfp_ag_indicators_nr = ag_indicators_nr;
2597     (void)memcpy(hfp_ag_indicators, ag_indicators,
2598                  ag_indicators_nr * sizeof(hfp_ag_indicator_t));
2599 }
2600 
2601 void hfp_ag_init_hf_indicators(int hf_indicators_nr, const hfp_generic_status_indicator_t * hf_indicators){
2602     if (hf_indicators_nr > HFP_MAX_NUM_INDICATORS) return;
2603     hfp_ag_generic_status_indicators_nr = hf_indicators_nr;
2604     (void)memcpy(hfp_ag_generic_status_indicators, hf_indicators,
2605                  hf_indicators_nr * sizeof(hfp_generic_status_indicator_t));
2606 }
2607 
2608 void hfp_ag_init_call_hold_services(int call_hold_services_nr, const char * call_hold_services[]){
2609     hfp_ag_call_hold_services_nr = call_hold_services_nr;
2610     (void)memcpy(hfp_ag_call_hold_services, call_hold_services,
2611                  call_hold_services_nr * sizeof(char *));
2612 }
2613 
2614 
2615 void hfp_ag_init(uint8_t rfcomm_channel_nr){
2616 
2617     hfp_init();
2618     hfp_ag_call_hold_services_nr = 0;
2619     hfp_ag_response_and_hold_active = false;
2620     hfp_ag_indicators_nr = 0;
2621     hfp_ag_codecs_nr = 0;
2622     hfp_ag_supported_features = HFP_DEFAULT_AG_SUPPORTED_FEATURES;
2623     hfp_ag_subscriber_numbers = NULL;
2624     hfp_ag_subscriber_numbers_count = 0;
2625 
2626     hfp_ag_hci_event_callback_registration.callback = &hfp_ag_hci_event_packet_handler;
2627     hci_add_event_handler(&hfp_ag_hci_event_callback_registration);
2628 
2629     rfcomm_register_service(&hfp_ag_rfcomm_packet_handler, rfcomm_channel_nr, 0xffff);
2630 
2631     // used to set packet handler for outgoing rfcomm connections - could be handled by emitting an event to us
2632     hfp_set_ag_rfcomm_packet_handler(&hfp_ag_rfcomm_packet_handler);
2633 
2634     hfp_gsm_init();
2635 }
2636 
2637 void hfp_ag_deinit(void){
2638     hfp_deinit();
2639     hfp_gsm_deinit();
2640 
2641     hfp_ag_callback = NULL;
2642     hfp_ag_supported_features = 0;
2643     hfp_ag_codecs_nr = 0;
2644     hfp_ag_indicators_nr = 0;
2645     hfp_ag_call_hold_services_nr = 0;
2646     (void) memset(&hfp_ag_call_hold_services, 0, sizeof(hfp_ag_call_hold_services));
2647     hfp_ag_response_and_hold_state = HFP_RESPONSE_AND_HOLD_INCOMING_ON_HOLD;
2648     (void) memset(&hfp_ag_response_and_hold_state, 0, sizeof(hfp_response_and_hold_state_t));
2649     hfp_ag_subscriber_numbers = NULL;
2650     (void) memset(&hfp_ag_hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
2651     hfp_ag_custom_call_sm_handler = NULL;
2652 }
2653 
2654 uint8_t hfp_ag_establish_service_level_connection(bd_addr_t bd_addr){
2655     return hfp_establish_service_level_connection(bd_addr, BLUETOOTH_SERVICE_CLASS_HANDSFREE, HFP_ROLE_AG);
2656 }
2657 
2658 uint8_t hfp_ag_release_service_level_connection(hci_con_handle_t acl_handle){
2659     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2660     if (!hfp_connection){
2661         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2662     }
2663 
2664     hfp_trigger_release_service_level_connection(hfp_connection);
2665     hfp_ag_run_for_context(hfp_connection);
2666     return ERROR_CODE_SUCCESS;
2667 }
2668 
2669 uint8_t hfp_ag_report_extended_audio_gateway_error_result_code(hci_con_handle_t acl_handle, hfp_cme_error_t error){
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_connection->extended_audio_gateway_error = 0;
2676     if (!hfp_connection->enable_extended_audio_gateway_error_report){
2677         return ERROR_CODE_COMMAND_DISALLOWED;
2678     }
2679 
2680     hfp_connection->extended_audio_gateway_error = error;
2681     hfp_ag_run_for_context(hfp_connection);
2682     return ERROR_CODE_SUCCESS;
2683 }
2684 
2685 static uint8_t hfp_ag_setup_audio_connection(hfp_connection_t * hfp_connection){
2686     if (hfp_connection->state == HFP_AUDIO_CONNECTION_ESTABLISHED){
2687         return ERROR_CODE_COMMAND_DISALLOWED;
2688     }
2689     if (hfp_connection->state >= HFP_W2_DISCONNECT_SCO){
2690         return ERROR_CODE_COMMAND_DISALLOWED;
2691     }
2692 
2693     hfp_connection->establish_audio_connection = 1;
2694     if (!has_codec_negotiation_feature(hfp_connection)){
2695         log_info("hfp_ag_establish_audio_connection - no codec negotiation feature, using CVSD");
2696         hfp_connection->negotiated_codec = HFP_CODEC_CVSD;
2697         hfp_connection->codecs_state = HFP_CODECS_EXCHANGED;
2698         // now, pick link settings
2699         hfp_init_link_settings(hfp_connection, hfp_ag_esco_s4_supported(hfp_connection));
2700 #ifdef ENABLE_CC256X_ASSISTED_HFP
2701         hfp_cc256x_prepare_for_sco(hfp_connection);
2702 #endif
2703         return ERROR_CODE_SUCCESS;
2704     }
2705 
2706     uint8_t i;
2707     bool codec_was_in_use = false;
2708     bool better_codec_can_be_used = false;
2709 
2710     for (i = 0; i<hfp_connection->remote_codecs_nr; i++){
2711         if (hfp_connection->negotiated_codec == hfp_connection->remote_codecs[i]){
2712             codec_was_in_use = true;
2713         } else if (hfp_connection->negotiated_codec < hfp_connection->remote_codecs[i]){
2714             better_codec_can_be_used = true;
2715         }
2716     }
2717 
2718     if (!codec_was_in_use || better_codec_can_be_used){
2719         hfp_connection->ag_send_common_codec = true;
2720         hfp_connection->codecs_state = HFP_CODECS_IDLE;
2721     }
2722     return ERROR_CODE_SUCCESS;
2723 }
2724 
2725 uint8_t hfp_ag_establish_audio_connection(hci_con_handle_t acl_handle){
2726     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2727     if (!hfp_connection){
2728         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2729     }
2730     uint8_t status = hfp_ag_setup_audio_connection(hfp_connection);
2731     if (status != ERROR_CODE_SUCCESS){
2732         return status;
2733     }
2734     hfp_ag_run_for_context(hfp_connection);
2735     return ERROR_CODE_SUCCESS;
2736 }
2737 
2738 uint8_t hfp_ag_release_audio_connection(hci_con_handle_t acl_handle){
2739     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2740     if (!hfp_connection){
2741         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2742     }
2743 
2744     if (hfp_connection->vra_state == HFP_VRA_VOICE_RECOGNITION_ACTIVATED){
2745         return ERROR_CODE_COMMAND_DISALLOWED;
2746     }
2747 
2748     uint8_t status = hfp_trigger_release_audio_connection(hfp_connection);
2749     if (status == ERROR_CODE_SUCCESS){
2750         hfp_ag_run_for_context(hfp_connection);
2751     }
2752     return status;
2753 }
2754 
2755 /**
2756  * @brief Enable in-band ring tone
2757  */
2758 void hfp_ag_set_use_in_band_ring_tone(int use_in_band_ring_tone){
2759     if (get_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE) == use_in_band_ring_tone){
2760         return;
2761     }
2762 
2763     hfp_ag_supported_features = store_bit(hfp_ag_supported_features, HFP_AGSF_IN_BAND_RING_TONE, use_in_band_ring_tone);
2764 
2765     btstack_linked_list_iterator_t it;
2766     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2767     while (btstack_linked_list_iterator_has_next(&it)){
2768         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2769         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2770         hfp_connection->ag_send_in_band_ring_tone_setting = true;
2771         hfp_ag_run_for_context(hfp_connection);
2772     }
2773 }
2774 
2775 /**
2776  * @brief Called from GSM
2777  */
2778 void hfp_ag_incoming_call(void){
2779     hfp_ag_call_sm(HFP_AG_INCOMING_CALL, NULL);
2780 }
2781 
2782 void hfp_ag_outgoing_call_initiated(void) {
2783     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_INITIATED_BY_AG, NULL);
2784 }
2785 
2786 /**
2787  * @brief number is stored.
2788  */
2789 void hfp_ag_set_clip(uint8_t type, const char * number){
2790     hfp_gsm_handler(HFP_AG_SET_CLIP, 0, type, number);
2791 }
2792 
2793 void hfp_ag_call_dropped(void){
2794     hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2795 }
2796 
2797 // call from AG UI
2798 void hfp_ag_answer_incoming_call(void){
2799     hfp_ag_call_sm(HFP_AG_INCOMING_CALL_ACCEPTED_BY_AG, NULL);
2800 }
2801 
2802 void hfp_ag_join_held_call(void){
2803     hfp_ag_call_sm(HFP_AG_HELD_CALL_JOINED_BY_AG, NULL);
2804 }
2805 
2806 void hfp_ag_terminate_call(void){
2807     hfp_ag_call_sm(HFP_AG_TERMINATE_CALL_BY_AG, NULL);
2808 }
2809 
2810 void hfp_ag_outgoing_call_ringing(void){
2811     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_RINGING, NULL);
2812 }
2813 
2814 void hfp_ag_outgoing_call_established(void){
2815     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ESTABLISHED, NULL);
2816 }
2817 
2818 void hfp_ag_outgoing_call_rejected(void){
2819     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_REJECTED, NULL);
2820 }
2821 
2822 void hfp_ag_outgoing_call_accepted(void){
2823     hfp_ag_call_sm(HFP_AG_OUTGOING_CALL_ACCEPTED, NULL);
2824 }
2825 
2826 void hfp_ag_hold_incoming_call(void){
2827     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_INCOMING_CALL_BY_AG, NULL);
2828 }
2829 
2830 void hfp_ag_accept_held_incoming_call(void) {
2831     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_ACCEPT_HELD_CALL_BY_AG, NULL);
2832 }
2833 
2834 void hfp_ag_reject_held_incoming_call(void){
2835     hfp_ag_call_sm(HFP_AG_RESPONSE_AND_HOLD_REJECT_HELD_CALL_BY_AG, NULL);
2836 }
2837 
2838 static void hfp_ag_set_ag_indicator(const char * name, int value){
2839     int indicator_index = get_ag_indicator_index_for_name(name);
2840     if (indicator_index < 0) return;
2841     hfp_ag_indicators[indicator_index].status = value;
2842 
2843     btstack_linked_list_iterator_t it;
2844     btstack_linked_list_iterator_init(&it, hfp_get_connections());
2845     while (btstack_linked_list_iterator_has_next(&it)){
2846         hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2847         if (hfp_connection->local_role != HFP_ROLE_AG) continue;
2848         if (!hfp_connection->ag_indicators[indicator_index].enabled) {
2849             log_info("Requested AG indicator '%s' update to %u, but it is not enabled", hfp_ag_indicators[indicator_index].name, value);
2850             continue;
2851         }
2852         log_info("AG indicator '%s' changed to %u, request transfer status", hfp_ag_indicators[indicator_index].name, value);
2853         hfp_connection->ag_indicators_status_update_bitmap = store_bit(hfp_connection->ag_indicators_status_update_bitmap, indicator_index, 1);
2854         hfp_ag_run_for_context(hfp_connection);
2855     }
2856 }
2857 
2858 uint8_t hfp_ag_set_registration_status(int registration_status){
2859     if ((registration_status < 0) || (registration_status > 1)){
2860         return ERROR_CODE_COMMAND_DISALLOWED;
2861     }
2862 
2863     if ( (registration_status == 0) && (hfp_gsm_call_status() == HFP_CALL_STATUS_ACTIVE_OR_HELD_CALL_IS_PRESENT)){
2864 
2865         // if network goes away wihle a call is active:
2866         // - the  call gets dropped
2867         // - we send NO CARRIER
2868         // NOTE: the CALL=0 has to be sent before NO CARRIER
2869 
2870         hfp_ag_call_sm(HFP_AG_CALL_DROPPED, NULL);
2871 
2872         btstack_linked_list_iterator_t it;
2873         btstack_linked_list_iterator_init(&it, hfp_get_connections());
2874         while (btstack_linked_list_iterator_has_next(&it)){
2875             hfp_connection_t * hfp_connection = (hfp_connection_t *)btstack_linked_list_iterator_next(&it);
2876             hfp_connection->ag_send_no_carrier = true;
2877         }
2878     }
2879     hfp_ag_set_ag_indicator("service", registration_status);
2880     return ERROR_CODE_SUCCESS;
2881 }
2882 
2883 uint8_t hfp_ag_set_signal_strength(int signal_strength){
2884     if ((signal_strength < 0) || (signal_strength > 5)){
2885         return ERROR_CODE_COMMAND_DISALLOWED;
2886     }
2887 
2888     hfp_ag_set_ag_indicator("signal", signal_strength);
2889     return ERROR_CODE_SUCCESS;
2890 }
2891 
2892 uint8_t hfp_ag_set_roaming_status(int roaming_status){
2893     if ((roaming_status < 0) || (roaming_status > 1)){
2894         return ERROR_CODE_COMMAND_DISALLOWED;
2895     }
2896 
2897     hfp_ag_set_ag_indicator("roam", roaming_status);
2898     return ERROR_CODE_SUCCESS;
2899 }
2900 
2901 uint8_t hfp_ag_set_battery_level(int battery_level){
2902     if ((battery_level < 0) || (battery_level > 5)){
2903         return ERROR_CODE_COMMAND_DISALLOWED;
2904     }
2905     hfp_ag_set_ag_indicator("battchg", battery_level);
2906     return ERROR_CODE_SUCCESS;
2907 }
2908 
2909 uint8_t hfp_ag_activate_voice_recognition(hci_con_handle_t acl_handle){
2910     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2911     if (!hfp_connection){
2912         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2913     }
2914 
2915     if (hfp_connection->emit_vra_enabled_after_audio_established){
2916         return ERROR_CODE_COMMAND_DISALLOWED;
2917     }
2918 
2919     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2920     bool legacy_vra_supported   = hfp_ag_vra_flag_supported(hfp_connection);
2921     if (!enhanced_vra_supported && !legacy_vra_supported){
2922         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2923     }
2924 
2925     if (!hfp_ag_can_activate_voice_recognition(hfp_connection)){
2926         return ERROR_CODE_COMMAND_DISALLOWED;
2927     }
2928 
2929     hfp_connection->ag_activate_voice_recognition_value = 1;
2930     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_ACTIVATED;
2931     hfp_connection->enhanced_voice_recognition_enabled = enhanced_vra_supported;
2932     hfp_connection->ag_audio_connection_opened_before_vra = hfp_ag_is_audio_connection_active(hfp_connection);
2933     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2934     hfp_connection->ag_vra_send_command = true;
2935     hfp_ag_run_for_context(hfp_connection);
2936     return ERROR_CODE_SUCCESS;
2937 }
2938 
2939 uint8_t hfp_ag_deactivate_voice_recognition(hci_con_handle_t acl_handle){
2940     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2941     if (!hfp_connection){
2942         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2943     }
2944 
2945     if (hfp_connection->emit_vra_enabled_after_audio_established){
2946         return ERROR_CODE_COMMAND_DISALLOWED;
2947     }
2948 
2949     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2950     bool legacy_vra_supported = hfp_ag_vra_flag_supported(hfp_connection);
2951 
2952     if (!enhanced_vra_supported && !legacy_vra_supported){
2953         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2954     }
2955 
2956     if (!hfp_ag_voice_recognition_session_active(hfp_connection)){
2957         return ERROR_CODE_COMMAND_DISALLOWED;
2958     }
2959 
2960     hfp_connection->ag_activate_voice_recognition_value = 0;
2961     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_VOICE_RECOGNITION_OFF;
2962     hfp_connection->ag_vra_state = HFP_VOICE_RECOGNITION_STATE_AG_READY;
2963     hfp_connection->ag_vra_send_command = true;
2964     hfp_ag_run_for_context(hfp_connection);
2965     return ERROR_CODE_SUCCESS;
2966 }
2967 
2968 static uint8_t hfp_ag_enhanced_voice_recognition_send_state(hci_con_handle_t acl_handle, hfp_voice_recognition_state_t state){
2969     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
2970     if (!hfp_connection){
2971         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
2972     }
2973 
2974     if (hfp_connection->emit_vra_enabled_after_audio_established){
2975         return ERROR_CODE_COMMAND_DISALLOWED;
2976     }
2977 
2978     if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED){
2979         return ERROR_CODE_COMMAND_DISALLOWED;
2980     }
2981 
2982     if (hfp_connection->vra_state != HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
2983         return ERROR_CODE_COMMAND_DISALLOWED;
2984     }
2985 
2986     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
2987     if (!enhanced_vra_supported ){
2988         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
2989     }
2990 
2991 
2992     hfp_connection->ag_vra_state = state;
2993     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_STATUS;
2994     hfp_connection->ag_vra_send_command = true;
2995     hfp_ag_run_for_context(hfp_connection);
2996     return ERROR_CODE_SUCCESS;
2997 }
2998 
2999 uint8_t hfp_ag_enhanced_voice_recognition_report_sending_audio(hci_con_handle_t acl_handle){
3000     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_STARTING_SOUND);
3001 }
3002 uint8_t hfp_ag_enhanced_voice_recognition_report_ready_for_audio(hci_con_handle_t acl_handle){
3003     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_READY_TO_ACCEPT_AUDIO_INPUT);
3004 }
3005 uint8_t hfp_ag_enhanced_voice_recognition_report_processing_input(hci_con_handle_t acl_handle){
3006     return hfp_ag_enhanced_voice_recognition_send_state(acl_handle, HFP_VOICE_RECOGNITION_STATE_AG_IS_PROCESSING_AUDIO_INPUT);
3007 }
3008 
3009 
3010 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){
3011     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3012     if (!hfp_connection){
3013         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3014     }
3015 
3016     if (hfp_connection->emit_vra_enabled_after_audio_established){
3017         return ERROR_CODE_COMMAND_DISALLOWED;
3018     }
3019 
3020     if (hfp_connection->state != HFP_AUDIO_CONNECTION_ESTABLISHED){
3021         return ERROR_CODE_COMMAND_DISALLOWED;
3022     }
3023 
3024     if (hfp_connection->vra_state != HFP_VRA_ENHANCED_VOICE_RECOGNITION_READY_FOR_AUDIO){
3025         return ERROR_CODE_COMMAND_DISALLOWED;
3026     }
3027 
3028     bool enhanced_vra_supported = hfp_ag_enhanced_vra_flag_supported(hfp_connection);
3029     if (!enhanced_vra_supported ){
3030         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3031     }
3032 
3033     bool enhanced_vra_msg_supported = hfp_ag_can_send_enhanced_vra_message_flag_supported(hfp_connection);
3034     if (!enhanced_vra_msg_supported ){
3035         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3036     }
3037 
3038     uint16_t message_len = (uint16_t) strlen(msg.text);
3039 
3040     if (message_len > HFP_MAX_VR_TEXT_SIZE){
3041         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3042     }
3043 
3044     if ((HFP_VR_TEXT_HEADER_SIZE + message_len) > hfp_connection->rfcomm_mtu){
3045         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3046     }
3047 
3048     hfp_connection->vra_state_requested = HFP_VRA_W2_SEND_ENHANCED_VOICE_RECOGNITION_MSG;
3049     hfp_connection->ag_msg = msg;
3050     hfp_connection->ag_vra_state = state;
3051     hfp_connection->ag_vra_send_command = true;
3052     hfp_ag_run_for_context(hfp_connection);
3053 
3054     return ERROR_CODE_SUCCESS;
3055 }
3056 
3057 
3058 uint8_t hfp_ag_set_microphone_gain(hci_con_handle_t acl_handle, int gain){
3059     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3060     if (!hfp_connection){
3061         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3062     }
3063 
3064     if ((gain < 0) || (gain > 15)){
3065         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
3066         return ERROR_CODE_COMMAND_DISALLOWED;
3067     }
3068 
3069     if (hfp_connection->microphone_gain != gain){
3070         hfp_connection->microphone_gain = gain;
3071         hfp_connection->send_microphone_gain = 1;
3072     }
3073     hfp_ag_run_for_context(hfp_connection);
3074     return ERROR_CODE_SUCCESS;
3075 }
3076 
3077 uint8_t hfp_ag_set_speaker_gain(hci_con_handle_t acl_handle, int gain){
3078     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3079     if (!hfp_connection){
3080         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3081     }
3082 
3083     if ((gain < 0) || (gain > 15)){
3084         log_info("Valid range for a gain is [0..15]. Currently sent: %d", gain);
3085         return ERROR_CODE_COMMAND_DISALLOWED;
3086     }
3087 
3088     if (hfp_connection->speaker_gain != gain){
3089         hfp_connection->speaker_gain = gain;
3090         hfp_connection->send_speaker_gain = 1;
3091     }
3092     hfp_ag_run_for_context(hfp_connection);
3093     return ERROR_CODE_SUCCESS;
3094 }
3095 
3096 uint8_t hfp_ag_send_phone_number_for_voice_tag(hci_con_handle_t acl_handle, const char * number){
3097     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3098     if (!hfp_connection){
3099         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3100     }
3101 
3102     hfp_ag_set_clip(0, number);
3103     hfp_connection->send_phone_number_for_voice_tag = 1;
3104     return ERROR_CODE_SUCCESS;
3105 }
3106 
3107 uint8_t hfp_ag_reject_phone_number_for_voice_tag(hci_con_handle_t acl_handle){
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_connection->send_error = 1;
3114     return ERROR_CODE_SUCCESS;
3115 }
3116 
3117 uint8_t hfp_ag_send_dtmf_code_done(hci_con_handle_t acl_handle){
3118     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3119     if (!hfp_connection){
3120         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3121     }
3122 
3123     hfp_connection->ok_pending = 1;
3124     return ERROR_CODE_SUCCESS;
3125 }
3126 
3127 uint8_t hfp_ag_send_unsolicited_result_code(hci_con_handle_t acl_handle, const char * unsolicited_result_code){
3128     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3129     if (!hfp_connection){
3130         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3131     }
3132     if (hfp_connection->send_custom_message != NULL){
3133         return ERROR_CODE_COMMAND_DISALLOWED;
3134     }
3135     hfp_connection->send_custom_message = unsolicited_result_code;
3136     hfp_ag_run_for_context(hfp_connection);
3137     return ERROR_CODE_SUCCESS;
3138 }
3139 
3140 uint8_t hfp_ag_send_command_result_code(hci_con_handle_t acl_handle, bool ok){
3141     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3142     if (!hfp_connection){
3143         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3144     }
3145     if (ok){
3146         hfp_connection->ok_pending = 1;
3147     } else {
3148         hfp_connection->send_error = 1;
3149     }
3150     hfp_ag_run_for_context(hfp_connection);
3151     return ERROR_CODE_SUCCESS;
3152 }
3153 
3154 void hfp_ag_set_subcriber_number_information(hfp_phone_number_t * numbers, int numbers_count){
3155     hfp_ag_subscriber_numbers = numbers;
3156     hfp_ag_subscriber_numbers_count = numbers_count;
3157 }
3158 
3159 void hfp_ag_clear_last_dialed_number(void){
3160     hfp_gsm_clear_last_dialed_number();
3161 }
3162 
3163 void hfp_ag_set_last_dialed_number(const char * number){
3164     hfp_gsm_set_last_dialed_number(number);
3165 }
3166 
3167 uint8_t hfp_ag_notify_incoming_call_waiting(hci_con_handle_t acl_handle){
3168     hfp_connection_t * hfp_connection = get_hfp_ag_connection_context_for_acl_handle(acl_handle);
3169     if (!hfp_connection){
3170         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
3171     }
3172 
3173     if (!hfp_connection->call_waiting_notification_enabled){
3174         return ERROR_CODE_COMMAND_DISALLOWED;
3175     }
3176 
3177     hfp_connection->ag_notify_incoming_call_waiting = 1;
3178     hfp_ag_run_for_context(hfp_connection);
3179     return ERROR_CODE_SUCCESS;
3180 }
3181 
3182 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){
3183 	if (!name){
3184 		name = hfp_ag_default_service_name;
3185 	}
3186 	hfp_create_sdp_record(service, service_record_handle, BLUETOOTH_SERVICE_CLASS_HANDSFREE_AUDIO_GATEWAY, rfcomm_channel_nr, name);
3187 
3188 	/*
3189 	 * 0x01 – Ability to reject a call
3190 	 * 0x00 – No ability to reject a call
3191 	 */
3192 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0301);    // Hands-Free Profile - Network
3193 	de_add_number(service, DE_UINT, DE_SIZE_8, ability_to_reject_call);
3194 
3195 	// Construct SupportedFeatures for SDP bitmap:
3196 	//
3197 	// "The values of the “SupportedFeatures” bitmap given in Table 5.4 shall be the same as the values
3198 	//  of the Bits 0 to 4 of the unsolicited result code +BRSF"
3199 	//
3200 	// Wide band speech (bit 5) requires Codec negotiation
3201 	//
3202 	uint16_t sdp_features = supported_features & 0x1f;
3203 	if ( (wide_band_speech == 1) && (supported_features & (1 << HFP_AGSF_CODEC_NEGOTIATION))){
3204 		sdp_features |= 1 << 5;
3205 	}
3206 
3207     if (supported_features & (1 << HFP_AGSF_ENHANCED_VOICE_RECOGNITION_STATUS)){
3208         sdp_features |= 1 << 6;
3209     }
3210 
3211     if (supported_features & (1 << HFP_AGSF_VOICE_RECOGNITION_TEXT)){
3212         sdp_features |= 1 << 7;
3213     }
3214 
3215 	de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);    // Hands-Free Profile - SupportedFeatures
3216 	de_add_number(service, DE_UINT, DE_SIZE_16, sdp_features);
3217 }
3218 
3219 void hfp_ag_register_packet_handler(btstack_packet_handler_t callback){
3220 	btstack_assert(callback != NULL);
3221 
3222 	hfp_ag_callback = callback;
3223 	hfp_set_ag_callback(callback);
3224 }
3225 
3226 void hfp_ag_register_custom_call_sm_handler(bool (*handler)(hfp_ag_call_event_t event)){
3227     hfp_ag_custom_call_sm_handler = handler;
3228 }
3229 
3230 void hfp_ag_register_custom_at_command(hfp_custom_at_command_t * custom_at_command){
3231     hfp_register_custom_ag_command(custom_at_command);
3232 }
3233