xref: /btstack/src/mesh/mesh_access.c (revision 20cc5dae5d8da524ee4ed3806be134682870aab8)
1 /*
2  * Copyright (C) 2019 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 MATTHIAS
24  * RINGWALD 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__ "mesh_access.c"
39 
40 #include <string.h>
41 #include <stdio.h>
42 #include <stdarg.h>
43 
44 #include "mesh/mesh_access.h"
45 
46 #include "btstack_debug.h"
47 #include "btstack_memory.h"
48 #include "btstack_tlv.h"
49 
50 #include "mesh/beacon.h"
51 #include "mesh/mesh_foundation.h"
52 #include "mesh/mesh_iv_index_seq_number.h"
53 #include "mesh/mesh_node.h"
54 #include "mesh/mesh_proxy.h"
55 #include "mesh/mesh_upper_transport.h"
56 #include "mesh/mesh.h"
57 
58 #define MEST_TRANSACTION_TIMEOUT_MS  6000
59 
60 static void mesh_access_message_process_handler(mesh_pdu_t * pdu);
61 static void mesh_access_upper_transport_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
62 static const mesh_operation_t * mesh_model_lookup_operation_by_opcode(mesh_model_t * model, uint32_t opcode);
63 
64 // acknowledged messages
65 static btstack_linked_list_t  mesh_access_acknowledged_messages;
66 static btstack_timer_source_t mesh_access_acknowledged_timer;
67 static int                    mesh_access_acknowledged_timer_active;
68 
69 // Transitions
70 static btstack_linked_list_t  transitions;
71 static btstack_timer_source_t transitions_timer;
72 static uint32_t transition_step_min_ms;
73 static uint8_t mesh_transaction_id_counter = 0;
74 
75 void mesh_access_init(void){
76     // register with upper transport
77     mesh_upper_transport_register_access_message_handler(&mesh_access_message_process_handler);
78     mesh_upper_transport_set_higher_layer_handler(&mesh_access_upper_transport_handler);
79 }
80 
81 void mesh_access_emit_state_update_bool(btstack_packet_handler_t event_handler, uint8_t element_index, uint32_t model_identifier,
82     model_state_id_t state_identifier, model_state_update_reason_t reason, uint8_t value){
83     if (event_handler == NULL) return;
84     uint8_t event[14] = {HCI_EVENT_MESH_META, 12, MESH_SUBEVENT_STATE_UPDATE_BOOL};
85     int pos = 3;
86     event[pos++] = element_index;
87     little_endian_store_32(event, pos, model_identifier);
88     pos += 4;
89     little_endian_store_32(event, pos, (uint32_t)state_identifier);
90     pos += 4;
91     event[pos++] = (uint8_t)reason;
92     event[pos++] = value;
93     (*event_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
94 }
95 
96 void mesh_access_emit_state_update_int16(btstack_packet_handler_t event_handler, uint8_t element_index, uint32_t model_identifier,
97     model_state_id_t state_identifier, model_state_update_reason_t reason, int16_t value){
98     if (event_handler == NULL) return;
99     uint8_t event[15] = {HCI_EVENT_MESH_META, 13, MESH_SUBEVENT_STATE_UPDATE_BOOL};
100     int pos = 3;
101     event[pos++] = element_index;
102     little_endian_store_32(event, pos, model_identifier);
103     pos += 4;
104     little_endian_store_32(event, pos, (uint32_t)state_identifier);
105     pos += 4;
106     event[pos++] = (uint8_t)reason;
107     little_endian_store_16(event, pos, (uint16_t) value);
108     pos += 2;
109     (*event_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
110 }
111 
112 uint8_t mesh_access_acknowledged_message_retransmissions(void){
113     return 3;
114 }
115 
116 uint32_t mesh_access_acknowledged_message_timeout_ms(void){
117     return 30000;
118 }
119 
120 #define MESH_ACCESS_OPCODE_INVALID 0xFFFFFFFFu
121 
122 void mesh_access_send_unacknowledged_pdu(mesh_pdu_t * pdu){
123     pdu->ack_opcode = MESH_ACCESS_OPCODE_INVALID;;
124     mesh_upper_transport_send_access_pdu(pdu);
125 }
126 
127 void mesh_access_send_acknowledged_pdu(mesh_pdu_t * pdu, uint8_t retransmissions, uint32_t ack_opcode){
128     pdu->retransmit_count = retransmissions;
129     pdu->ack_opcode = ack_opcode;
130 
131     mesh_upper_transport_send_access_pdu(pdu);
132 }
133 
134 #define MESH_SUBEVENT_MESSAGE_NOT_ACKNOWLEDGED                                        0x30
135 
136 static void mesh_access_acknowledged_run(btstack_timer_source_t * ts){
137     UNUSED(ts);
138 
139     uint32_t now = btstack_run_loop_get_time_ms();
140 
141     // handle timeouts
142     btstack_linked_list_iterator_t ack_it;
143     btstack_linked_list_iterator_init(&ack_it, &mesh_access_acknowledged_messages);
144     while (btstack_linked_list_iterator_has_next(&ack_it)){
145         mesh_pdu_t * pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&ack_it);
146         if (btstack_time_delta(now, pdu->retransmit_timeout_ms) >= 0) {
147             // remove from list
148             btstack_linked_list_remove(&mesh_access_acknowledged_messages, (btstack_linked_item_t*) pdu);
149             // retransmit or report failure
150             if (pdu->retransmit_count){
151                 pdu->retransmit_count--;
152                 mesh_upper_transport_send_access_pdu(pdu);
153             } else {
154                 // find correct model and emit error
155                 uint16_t src = mesh_pdu_src(pdu);
156                 uint16_t dst = mesh_pdu_dst(pdu);
157                 mesh_element_t * element = mesh_node_element_for_unicast_address(src);
158                 if (element){
159                     // find
160                     mesh_model_iterator_t model_it;
161                     mesh_model_iterator_init(&model_it, element);
162                     while (mesh_model_iterator_has_next(&model_it)){
163                         mesh_model_t * model = mesh_model_iterator_next(&model_it);
164                         // find opcode in table
165                         const mesh_operation_t * operation = mesh_model_lookup_operation_by_opcode(model, pdu->ack_opcode);
166                         if (operation == NULL) continue;
167                         if (model->model_packet_handler == NULL) continue;
168                         // emit event
169                         uint8_t event[13];
170                         event[0] = HCI_EVENT_MESH_META;
171                         event[1] = sizeof(event) - 2;
172                         event[2] = element->element_index;
173                         little_endian_store_32(event, 3, model->model_identifier);
174                         little_endian_store_32(event, 7, pdu->ack_opcode);
175                         little_endian_store_16(event, 11, dst);
176                         (*model->model_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
177                     }
178                 }
179 
180                 // free
181                 mesh_upper_transport_pdu_free(pdu);
182             }
183         }
184     }
185 
186     if (mesh_access_acknowledged_timer_active) return;
187 
188     // find earliest timeout and set timer
189     btstack_linked_list_iterator_init(&ack_it, &mesh_access_acknowledged_messages);
190     int32_t next_timeout_ms = 0;
191     while (btstack_linked_list_iterator_has_next(&ack_it)){
192         mesh_pdu_t * pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&ack_it);
193         int32_t timeout_delta_ms = btstack_time_delta(pdu->retransmit_timeout_ms, now);
194         if (next_timeout_ms == 0 || timeout_delta_ms < next_timeout_ms){
195             next_timeout_ms = timeout_delta_ms;
196         }
197     }
198 
199     // set timer
200     if (next_timeout_ms == 0) return;
201 
202     btstack_run_loop_set_timer(&mesh_access_acknowledged_timer, next_timeout_ms);
203     btstack_run_loop_set_timer_handler(&mesh_access_acknowledged_timer, mesh_access_acknowledged_run);
204     btstack_run_loop_add_timer(&mesh_access_acknowledged_timer);
205     mesh_access_acknowledged_timer_active = 1;
206 }
207 
208 static void mesh_access_acknowledged_received(uint16_t rx_src, uint32_t opcode){
209     // check if received src matches our dest
210     // free acknowledged messages if we were waiting for this message
211 
212     btstack_linked_list_iterator_t ack_it;
213     btstack_linked_list_iterator_init(&ack_it, &mesh_access_acknowledged_messages);
214     while (btstack_linked_list_iterator_has_next(&ack_it)){
215         mesh_pdu_t * tx_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&ack_it);
216         uint16_t tx_dest = mesh_pdu_dst(tx_pdu);
217         if (tx_dest != rx_src) continue;
218         if (tx_pdu->ack_opcode != opcode) continue;
219         // got expected response from dest, remove from outgoing messages
220         mesh_upper_transport_pdu_free(tx_pdu);
221         return;
222     }
223 }
224 
225 static void mesh_access_upper_transport_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
226     UNUSED(status);
227     switch (callback_type){
228         case MESH_TRANSPORT_PDU_SENT:
229             // unacknowledged -> free
230             if (pdu->ack_opcode == MESH_ACCESS_OPCODE_INVALID){
231                 mesh_upper_transport_pdu_free(pdu);
232                 break;
233             }
234             // setup timeout
235             pdu->retransmit_timeout_ms = btstack_run_loop_get_time_ms() + mesh_access_acknowledged_message_timeout_ms();
236             // add to mesh_access_acknowledged_messages
237             btstack_linked_list_add(&mesh_access_acknowledged_messages, (btstack_linked_item_t *) pdu);
238             // update timer
239             mesh_access_acknowledged_run(NULL);
240             break;
241         default:
242             break;
243     }
244 }
245 
246 // Mesh Model Transitions
247 
248 void mesh_access_transitions_setup_transaction(mesh_transition_t * transition, uint8_t transaction_identifier, uint16_t src_address, uint16_t dst_address){
249     transition->transaction_timestamp_ms = btstack_run_loop_get_time_ms();
250     transition->transaction_identifier = transaction_identifier;
251     transition->src_address = src_address;
252     transition->dst_address = dst_address;
253 }
254 
255 void mesh_access_transitions_abort_transaction(mesh_transition_t * transition){
256     mesh_access_transitions_remove(transition);
257 }
258 
259 
260 static int mesh_access_transitions_transaction_is_expired(mesh_transition_t * transition){
261     return (btstack_run_loop_get_time_ms() - transition->transaction_timestamp_ms) > MEST_TRANSACTION_TIMEOUT_MS;
262 }
263 
264 mesh_transaction_status_t mesh_access_transitions_transaction_status(mesh_transition_t * transition, uint8_t transaction_identifier, uint16_t src_address, uint16_t dst_address){
265     if (transition->src_address != src_address || transition->dst_address != dst_address) return MESH_TRANSACTION_STATUS_DIFFERENT_DST_OR_SRC;
266 
267     if (transition->transaction_identifier == transaction_identifier && !mesh_access_transitions_transaction_is_expired(transition)){
268             return MESH_TRANSACTION_STATUS_RETRANSMISSION;
269     }
270     return MESH_TRANSACTION_STATUS_NEW;
271 }
272 
273 uint8_t mesh_access_transitions_num_steps_from_gdtt(uint8_t time_gdtt){
274     return time_gdtt & 0x3fu;
275 }
276 
277 static uint32_t mesh_access_transitions_step_ms_from_gdtt(uint8_t time_gdtt){
278     mesh_default_transition_step_resolution_t step_resolution = (mesh_default_transition_step_resolution_t) (time_gdtt >> 6);
279     switch (step_resolution){
280         case MESH_DEFAULT_TRANSITION_STEP_RESOLUTION_100ms:
281             return 100;
282         case MESH_DEFAULT_TRANSITION_STEP_RESOLUTION_1s:
283             return 1000;
284         case MESH_DEFAULT_TRANSITION_STEP_RESOLUTION_10s:
285             return 10000;
286         case MESH_DEFAULT_TRANSITION_STEP_RESOLUTION_10min:
287             return 600000;
288         default:
289             return 0;
290     }
291 }
292 
293 uint32_t mesh_access_time_gdtt2ms(uint8_t time_gdtt){
294     uint8_t num_steps  = mesh_access_transitions_num_steps_from_gdtt(time_gdtt);
295     if (num_steps > 0x3E) return 0;
296 
297     return mesh_access_transitions_step_ms_from_gdtt(time_gdtt) * num_steps;
298 }
299 
300 static void mesh_access_transitions_timeout_handler(btstack_timer_source_t * timer){
301     btstack_linked_list_iterator_t it;
302     btstack_linked_list_iterator_init(&it, &transitions);
303     while (btstack_linked_list_iterator_has_next(&it)){
304         mesh_transition_t * transition = (mesh_transition_t *)btstack_linked_list_iterator_next(&it);
305         (transition->transition_callback)(transition, TRANSITION_UPDATE, btstack_run_loop_get_time_ms());
306     }
307     if (btstack_linked_list_empty(&transitions)) return;
308 
309     btstack_run_loop_set_timer(timer, transition_step_min_ms);
310     btstack_run_loop_add_timer(timer);
311 }
312 
313 static void mesh_access_transitions_timer_start(void){
314     btstack_run_loop_remove_timer(&transitions_timer);
315     btstack_run_loop_set_timer_handler(&transitions_timer, mesh_access_transitions_timeout_handler);
316     btstack_run_loop_set_timer(&transitions_timer, transition_step_min_ms);
317     btstack_run_loop_add_timer(&transitions_timer);
318 }
319 
320 static void mesh_access_transitions_timer_stop(void){
321     btstack_run_loop_remove_timer(&transitions_timer);
322 }
323 
324 static uint32_t mesh_access_transitions_get_step_min_ms(void){
325     uint32_t min_timeout_ms = 0;
326 
327     btstack_linked_list_iterator_t it;
328     btstack_linked_list_iterator_init(&it, &transitions);
329     while (btstack_linked_list_iterator_has_next(&it)){
330         mesh_transition_t * transition = (mesh_transition_t *)btstack_linked_list_iterator_next(&it);
331         if (min_timeout_ms == 0 || transition->step_duration_ms < min_timeout_ms){
332             min_timeout_ms = transition->step_duration_ms;
333         }
334     }
335     return min_timeout_ms;
336 }
337 
338 void mesh_access_transitions_setup(mesh_transition_t * transition, mesh_model_t * mesh_model,
339     uint8_t transition_time_gdtt, uint8_t delay_gdtt,
340     void (* transition_callback)(struct mesh_transition * transition, transition_event_t event, uint32_t current_timestamp)){
341 
342     //  Only values of 0x00 through 0x3E shall be used to specify the value of the Transition Number of Steps field
343     uint8_t num_steps  = mesh_access_transitions_num_steps_from_gdtt(transition_time_gdtt);
344     if (num_steps > 0x3E) return;
345 
346     transition->state = MESH_TRANSITION_STATE_IDLE;
347     transition->phase_start_ms = 0;
348 
349     transition->mesh_model = mesh_model;
350     transition->transition_callback = transition_callback;
351     transition->step_duration_ms = mesh_access_transitions_step_ms_from_gdtt(transition_time_gdtt);
352     transition->remaining_delay_time_ms = delay_gdtt * 5;
353     transition->remaining_transition_time_ms = num_steps * transition->step_duration_ms;
354 }
355 
356 void mesh_access_transitions_add(mesh_transition_t * transition){
357     if (transition->step_duration_ms == 0) return;
358 
359     if (btstack_linked_list_empty(&transitions) || transition->step_duration_ms < transition_step_min_ms){
360         transition_step_min_ms = transition->step_duration_ms;
361     }
362     mesh_access_transitions_timer_start();
363     btstack_linked_list_add(&transitions, (btstack_linked_item_t *) transition);
364     (transition->transition_callback)(transition, TRANSITION_START, btstack_run_loop_get_time_ms());
365 }
366 
367 void mesh_access_transitions_remove(mesh_transition_t * transition){
368     mesh_access_transitions_setup(transition, NULL, 0, 0, NULL);
369     btstack_linked_list_remove(&transitions, (btstack_linked_item_t *) transition);
370 
371     if (btstack_linked_list_empty(&transitions)){
372         mesh_access_transitions_timer_stop();
373     } else {
374         transition_step_min_ms = mesh_access_transitions_get_step_min_ms();
375     }
376 }
377 
378 uint8_t mesh_access_transactions_get_next_transaction_id(void){
379     mesh_transaction_id_counter++;
380     if (mesh_transaction_id_counter == 0){
381         mesh_transaction_id_counter = 1;
382     }
383     return mesh_transaction_id_counter;
384 }
385 
386 uint16_t mesh_pdu_ttl(mesh_pdu_t * pdu){
387     switch (pdu->pdu_type){
388         case MESH_PDU_TYPE_TRANSPORT:
389             return mesh_transport_ttl((mesh_transport_pdu_t*) pdu);
390         case MESH_PDU_TYPE_NETWORK:
391             return mesh_network_ttl((mesh_network_pdu_t *) pdu);
392         default:
393             return 0;
394     }
395 }
396 
397 uint16_t mesh_pdu_src(mesh_pdu_t * pdu){
398     switch (pdu->pdu_type){
399         case MESH_PDU_TYPE_TRANSPORT:
400             return mesh_transport_src((mesh_transport_pdu_t*) pdu);
401         case MESH_PDU_TYPE_NETWORK:
402             return mesh_network_src((mesh_network_pdu_t *) pdu);
403         default:
404             return MESH_ADDRESS_UNSASSIGNED;
405     }
406 }
407 
408 uint16_t mesh_pdu_dst(mesh_pdu_t * pdu){
409     switch (pdu->pdu_type){
410         case MESH_PDU_TYPE_TRANSPORT:
411             return mesh_transport_dst((mesh_transport_pdu_t*) pdu);
412         case MESH_PDU_TYPE_NETWORK:
413             return mesh_network_dst((mesh_network_pdu_t *) pdu);
414         default:
415             return MESH_ADDRESS_UNSASSIGNED;
416     }
417 }
418 
419 uint16_t mesh_pdu_netkey_index(mesh_pdu_t * pdu){
420     switch (pdu->pdu_type){
421         case MESH_PDU_TYPE_TRANSPORT:
422             return ((mesh_transport_pdu_t*) pdu)->netkey_index;
423         case MESH_PDU_TYPE_NETWORK:
424             return ((mesh_network_pdu_t *) pdu)->netkey_index;
425         default:
426             return 0;
427     }
428 }
429 
430 uint16_t mesh_pdu_appkey_index(mesh_pdu_t * pdu){
431     switch (pdu->pdu_type){
432         case MESH_PDU_TYPE_TRANSPORT:
433             return ((mesh_transport_pdu_t*) pdu)->appkey_index;
434         case MESH_PDU_TYPE_NETWORK:
435             return ((mesh_network_pdu_t *) pdu)->appkey_index;
436         default:
437             return 0;
438     }
439 }
440 
441 uint16_t mesh_pdu_len(mesh_pdu_t * pdu){
442     switch (pdu->pdu_type){
443         case MESH_PDU_TYPE_TRANSPORT:
444             return ((mesh_transport_pdu_t*) pdu)->len;
445         case MESH_PDU_TYPE_NETWORK:
446             return ((mesh_network_pdu_t *) pdu)->len - 10;
447         default:
448             return 0;
449     }
450 }
451 
452 uint8_t * mesh_pdu_data(mesh_pdu_t * pdu){
453     switch (pdu->pdu_type){
454         case MESH_PDU_TYPE_TRANSPORT:
455             return ((mesh_transport_pdu_t*) pdu)->data;
456         case MESH_PDU_TYPE_NETWORK:
457             return &((mesh_network_pdu_t *) pdu)->data[10];
458         default:
459             return NULL;
460     }
461 }
462 
463 uint8_t mesh_pdu_control_opcode(mesh_pdu_t * pdu){
464     switch (pdu->pdu_type){
465         case MESH_PDU_TYPE_TRANSPORT:
466             return mesh_transport_control_opcode((mesh_transport_pdu_t*) pdu);
467         case MESH_PDU_TYPE_NETWORK:
468             return mesh_network_control_opcode((mesh_network_pdu_t *) pdu);
469         default:
470             return 0xff;
471     }
472 }
473 
474 // message parser
475 
476 static int mesh_access_get_opcode(uint8_t * buffer, uint16_t buffer_size, uint32_t * opcode, uint16_t * opcode_size){
477     switch (buffer[0] >> 6){
478         case 0:
479         case 1:
480             if (buffer[0] == 0x7f) return 0;
481             *opcode = buffer[0];
482             *opcode_size = 1;
483             return 1;
484         case 2:
485             if (buffer_size < 2) return 0;
486             *opcode = big_endian_read_16(buffer, 0);
487             *opcode_size = 2;
488             return 1;
489         case 3:
490             if (buffer_size < 3) return 0;
491             *opcode = (buffer[0] << 16) | little_endian_read_16(buffer, 1);
492             *opcode_size = 3;
493             return 1;
494         default:
495             return 0;
496     }
497 }
498 
499 static int mesh_access_transport_get_opcode(mesh_transport_pdu_t * transport_pdu, uint32_t * opcode, uint16_t * opcode_size){
500     return mesh_access_get_opcode(transport_pdu->data, transport_pdu->len, opcode, opcode_size);
501 }
502 
503 static int mesh_access_network_get_opcode(mesh_network_pdu_t * network_pdu, uint32_t * opcode, uint16_t * opcode_size){
504     // TransMIC already removed by mesh_upper_transport_validate_unsegmented_message_ccm
505     return mesh_access_get_opcode(&network_pdu->data[10], network_pdu->len - 10, opcode, opcode_size);
506 }
507 
508 int mesh_access_pdu_get_opcode(mesh_pdu_t * pdu, uint32_t * opcode, uint16_t * opcode_size){
509     switch (pdu->pdu_type){
510         case MESH_PDU_TYPE_TRANSPORT:
511             return mesh_access_transport_get_opcode((mesh_transport_pdu_t*) pdu, opcode, opcode_size);
512         case MESH_PDU_TYPE_NETWORK:
513             return mesh_access_network_get_opcode((mesh_network_pdu_t *) pdu, opcode, opcode_size);
514         default:
515             return 0;
516     }
517 }
518 
519 void mesh_access_parser_skip(mesh_access_parser_state_t * state, uint16_t bytes_to_skip){
520     state->data += bytes_to_skip;
521     state->len  -= bytes_to_skip;
522 }
523 
524 int mesh_access_parser_init(mesh_access_parser_state_t * state, mesh_pdu_t * pdu){
525     state->data = mesh_pdu_data(pdu);
526     state->len  = mesh_pdu_len(pdu);
527 
528     uint16_t opcode_size = 0;
529     int ok = mesh_access_get_opcode(state->data, state->len, &state->opcode, &opcode_size);
530     if (ok){
531         mesh_access_parser_skip(state, opcode_size);
532     }
533     return ok;
534 }
535 
536 uint16_t mesh_access_parser_available(mesh_access_parser_state_t * state){
537     return state->len;
538 }
539 
540 uint8_t mesh_access_parser_get_u8(mesh_access_parser_state_t * state){
541     uint8_t value = *state->data;
542     mesh_access_parser_skip(state, 1);
543     return value;
544 }
545 
546 uint16_t mesh_access_parser_get_u16(mesh_access_parser_state_t * state){
547     uint16_t value = little_endian_read_16(state->data, 0);
548     mesh_access_parser_skip(state, 2);
549     return value;
550 }
551 
552 uint32_t mesh_access_parser_get_u24(mesh_access_parser_state_t * state){
553     uint32_t value = little_endian_read_24(state->data, 0);
554     mesh_access_parser_skip(state, 3);
555     return value;
556 }
557 
558 uint32_t mesh_access_parser_get_u32(mesh_access_parser_state_t * state){
559     uint32_t value = little_endian_read_24(state->data, 0);
560     mesh_access_parser_skip(state, 4);
561     return value;
562 }
563 
564 void mesh_access_parser_get_u128(mesh_access_parser_state_t * state, uint8_t * dest){
565     reverse_128( state->data, dest);
566     mesh_access_parser_skip(state, 16);
567 }
568 
569 void mesh_access_parser_get_label_uuid(mesh_access_parser_state_t * state, uint8_t * dest){
570     memcpy( dest, state->data, 16);
571     mesh_access_parser_skip(state, 16);
572 }
573 
574 void mesh_access_parser_get_key(mesh_access_parser_state_t * state, uint8_t * dest){
575     memcpy( dest, state->data, 16);
576     mesh_access_parser_skip(state, 16);
577 }
578 
579 uint32_t mesh_access_parser_get_model_identifier(mesh_access_parser_state_t * parser){
580     if (mesh_access_parser_available(parser) == 4){
581         return mesh_access_parser_get_u32(parser);
582     } else {
583         return (BLUETOOTH_COMPANY_ID_BLUETOOTH_SIG_INC << 16) | mesh_access_parser_get_u16(parser);
584     }
585 }
586 
587 // Mesh Access Message Builder
588 
589 // message builder
590 
591 static int mesh_access_setup_opcode(uint8_t * buffer, uint32_t opcode){
592     if (opcode < 0x100){
593         buffer[0] = opcode;
594         return 1;
595     }
596     if (opcode < 0x10000){
597         big_endian_store_16(buffer, 0, opcode);
598         return 2;
599     }
600     buffer[0] = opcode >> 16;
601     little_endian_store_16(buffer, 1, opcode & 0xffff);
602     return 3;
603 }
604 
605 mesh_transport_pdu_t * mesh_access_transport_init(uint32_t opcode){
606     mesh_transport_pdu_t * pdu = mesh_transport_pdu_get();
607     if (!pdu) return NULL;
608 
609     pdu->len  = mesh_access_setup_opcode(pdu->data, opcode);
610     return pdu;
611 }
612 
613 void mesh_access_transport_add_uint8(mesh_transport_pdu_t * pdu, uint8_t value){
614     pdu->data[pdu->len++] = value;
615 }
616 
617 void mesh_access_transport_add_uint16(mesh_transport_pdu_t * pdu, uint16_t value){
618     little_endian_store_16(pdu->data, pdu->len, value);
619     pdu->len += 2;
620 }
621 
622 void mesh_access_transport_add_uint24(mesh_transport_pdu_t * pdu, uint32_t value){
623     little_endian_store_24(pdu->data, pdu->len, value);
624     pdu->len += 3;
625 }
626 
627 void mesh_access_transport_add_uint32(mesh_transport_pdu_t * pdu, uint32_t value){
628     little_endian_store_32(pdu->data, pdu->len, value);
629     pdu->len += 4;
630 }
631 void mesh_access_transport_add_model_identifier(mesh_transport_pdu_t * pdu, uint32_t model_identifier){
632     if (mesh_model_is_bluetooth_sig(model_identifier)){
633         mesh_access_transport_add_uint16( pdu, mesh_model_get_model_id(model_identifier) );
634     } else {
635         mesh_access_transport_add_uint32( pdu, model_identifier );
636     }
637 }
638 
639 mesh_network_pdu_t * mesh_access_network_init(uint32_t opcode){
640     mesh_network_pdu_t * pdu = mesh_network_pdu_get();
641     if (!pdu) return NULL;
642 
643     pdu->len  = mesh_access_setup_opcode(&pdu->data[10], opcode) + 10;
644     return pdu;
645 }
646 
647 void mesh_access_network_add_uint8(mesh_network_pdu_t * pdu, uint8_t value){
648     pdu->data[pdu->len++] = value;
649 }
650 
651 void mesh_access_network_add_uint16(mesh_network_pdu_t * pdu, uint16_t value){
652     little_endian_store_16(pdu->data, pdu->len, value);
653     pdu->len += 2;
654 }
655 
656 void mesh_access_network_add_uint24(mesh_network_pdu_t * pdu, uint16_t value){
657     little_endian_store_24(pdu->data, pdu->len, value);
658     pdu->len += 3;
659 }
660 
661 void mesh_access_network_add_uint32(mesh_network_pdu_t * pdu, uint16_t value){
662     little_endian_store_32(pdu->data, pdu->len, value);
663     pdu->len += 4;
664 }
665 
666 void mesh_access_network_add_model_identifier(mesh_network_pdu_t * pdu, uint32_t model_identifier){
667     if (mesh_model_is_bluetooth_sig(model_identifier)){
668         mesh_access_network_add_uint16( pdu, mesh_model_get_model_id(model_identifier) );
669     } else {
670         mesh_access_network_add_uint32( pdu, model_identifier );
671     }
672 }
673 
674 // access message template
675 
676 mesh_network_pdu_t * mesh_access_setup_unsegmented_message(const mesh_access_message_t *message_template, ...){
677     mesh_network_pdu_t * network_pdu = mesh_access_network_init(message_template->opcode);
678     if (!network_pdu) return NULL;
679 
680     va_list argptr;
681     va_start(argptr, message_template);
682 
683     // add params
684     const char * format = message_template->format;
685     uint16_t word;
686     uint32_t longword;
687     while (*format){
688         switch (*format){
689             case '1':
690                 word = va_arg(argptr, int);  // minimal va_arg is int: 2 bytes on 8+16 bit CPUs
691                 mesh_access_network_add_uint8( network_pdu, word);
692                 break;
693             case '2':
694                 word = va_arg(argptr, int);  // minimal va_arg is int: 2 bytes on 8+16 bit CPUs
695                 mesh_access_network_add_uint16( network_pdu, word);
696                 break;
697             case '3':
698                 longword = va_arg(argptr, uint32_t);
699                 mesh_access_network_add_uint24( network_pdu, longword);
700                 break;
701             case '4':
702                 longword = va_arg(argptr, uint32_t);
703                 mesh_access_network_add_uint32( network_pdu, longword);
704                 break;
705             case 'm':
706                 longword = va_arg(argptr, uint32_t);
707                 mesh_access_network_add_model_identifier( network_pdu, longword);
708                 break;
709             default:
710                 log_error("Unsupported mesh message format specifier '%c", *format);
711                 break;
712         }
713         format++;
714     }
715 
716     va_end(argptr);
717 
718     return network_pdu;
719 }
720 
721 mesh_transport_pdu_t * mesh_access_setup_segmented_message(const mesh_access_message_t *message_template, ...){
722     mesh_transport_pdu_t * transport_pdu = mesh_access_transport_init(message_template->opcode);
723     if (!transport_pdu) return NULL;
724 
725     va_list argptr;
726     va_start(argptr, message_template);
727 
728     // add params
729     const char * format = message_template->format;
730     uint16_t word;
731     uint32_t longword;
732     while (*format){
733         switch (*format++){
734             case '1':
735                 word = va_arg(argptr, int);  // minimal va_arg is int: 2 bytes on 8+16 bit CPUs
736                 mesh_access_transport_add_uint8( transport_pdu, word);
737                 break;
738             case '2':
739                 word = va_arg(argptr, int);  // minimal va_arg is int: 2 bytes on 8+16 bit CPUs
740                 mesh_access_transport_add_uint16( transport_pdu, word);
741                 break;
742             case '3':
743                 longword = va_arg(argptr, uint32_t);
744                 mesh_access_transport_add_uint24( transport_pdu, longword);
745                 break;
746             case '4':
747                 longword = va_arg(argptr, uint32_t);
748                 mesh_access_transport_add_uint32( transport_pdu, longword);
749                 break;
750             case 'm':
751                 longword = va_arg(argptr, uint32_t);
752                 mesh_access_transport_add_model_identifier( transport_pdu, longword);
753                 break;
754             default:
755                 break;
756         }
757     }
758 
759     va_end(argptr);
760 
761     return transport_pdu;
762 }
763 
764 static const mesh_operation_t * mesh_model_lookup_operation_by_opcode(mesh_model_t * model, uint32_t opcode){
765     // find opcode in table
766     const mesh_operation_t * operation = model->operations;
767     if (operation == NULL) return NULL;
768     for ( ; operation->handler != NULL ; operation++){
769         if (operation->opcode != opcode) continue;
770         return operation;
771     }
772     return NULL;
773 }
774 
775 static const mesh_operation_t * mesh_model_lookup_operation(mesh_model_t * model, mesh_pdu_t * pdu){
776 
777     uint32_t opcode = 0;
778     uint16_t opcode_size = 0;
779     int ok = mesh_access_pdu_get_opcode( pdu, &opcode, &opcode_size);
780     if (!ok) return NULL;
781 
782     uint16_t len = mesh_pdu_len(pdu);
783 
784     // find opcode in table
785     const mesh_operation_t * operation = model->operations;
786     if (operation == NULL) return NULL;
787     for ( ; operation->handler != NULL ; operation++){
788         if (operation->opcode != opcode) continue;
789         if ((opcode_size + operation->minimum_length) > len) continue;
790         return operation;
791     }
792     return NULL;
793 }
794 
795 static int mesh_access_validate_appkey_index(mesh_model_t * model, uint16_t appkey_index){
796     // DeviceKey is valid for all models
797     if (appkey_index == MESH_DEVICE_KEY_INDEX) return 1;
798     // check if AppKey that is bound to this particular model
799     return mesh_model_contains_appkey(model, appkey_index);
800 }
801 
802 static void mesh_access_message_process_handler(mesh_pdu_t * pdu){
803     // get opcode and size
804     uint32_t opcode = 0;
805     uint16_t opcode_size = 0;
806 
807 
808     int ok = mesh_access_pdu_get_opcode( pdu, &opcode, &opcode_size);
809     if (!ok) {
810         mesh_access_message_processed(pdu);
811         return;
812     }
813 
814     uint16_t len = mesh_pdu_len(pdu);
815     printf("MESH Access Message, Opcode = %x: ", opcode);
816     printf_hexdump(mesh_pdu_data(pdu), len);
817 
818     uint16_t src = mesh_pdu_src(pdu);
819     uint16_t dst = mesh_pdu_dst(pdu);
820     uint16_t appkey_index = mesh_pdu_appkey_index(pdu);
821     if (mesh_network_address_unicast(dst)){
822         // loookup element by unicast address
823         mesh_element_t * element = mesh_node_element_for_unicast_address(dst);
824         if (element != NULL){
825             // iterate over models, look for operation
826             mesh_model_iterator_t model_it;
827             mesh_model_iterator_init(&model_it, element);
828             while (mesh_model_iterator_has_next(&model_it)){
829                 mesh_model_t * model = mesh_model_iterator_next(&model_it);
830                 // find opcode in table
831                 const mesh_operation_t * operation = mesh_model_lookup_operation(model, pdu);
832                 if (operation == NULL) continue;
833                 if (mesh_access_validate_appkey_index(model, appkey_index) == 0) continue;
834                 mesh_access_acknowledged_received(src, opcode);
835                 operation->handler(model, pdu);
836                 return;
837             }
838         }
839     }
840     else if (mesh_network_address_group(dst)){
841 
842         // handle fixed group address
843         if (dst >= 0xff00){
844             int deliver_to_primary_element = 1;
845             switch (dst){
846                 case MESH_ADDRESS_ALL_PROXIES:
847                     if (mesh_foundation_gatt_proxy_get() == 1){
848                         deliver_to_primary_element = 1;
849                     }
850                     break;
851                 case MESH_ADDRESS_ALL_FRIENDS:
852                     // TODO: not implemented
853                     break;
854                 case MESH_ADDRESS_ALL_RELAYS:
855                     if (mesh_foundation_relay_get() == 1){
856                         deliver_to_primary_element =1;
857                     }
858                     break;
859                 case MESH_ADDRESS_ALL_NODES:
860                     deliver_to_primary_element = 1;
861                     break;
862                 default:
863                     break;
864             }
865             if (deliver_to_primary_element){
866                 mesh_model_iterator_t model_it;
867                 mesh_model_iterator_init(&model_it, mesh_node_get_primary_element());
868                 while (mesh_model_iterator_has_next(&model_it)){
869                     mesh_model_t * model = mesh_model_iterator_next(&model_it);
870                     // find opcode in table
871                     const mesh_operation_t * operation = mesh_model_lookup_operation(model, pdu);
872                     if (operation == NULL) continue;
873                     if (mesh_access_validate_appkey_index(model, appkey_index) == 0) continue;
874                     mesh_access_acknowledged_received(src, opcode);
875                     operation->handler(model, pdu);
876                     return;
877                 }
878             }
879         }
880         else {
881             // iterate over all elements / models, check subscription list
882             mesh_element_iterator_t it;
883             mesh_element_iterator_init(&it);
884             while (mesh_element_iterator_has_next(&it)){
885                 mesh_element_t * element = (mesh_element_t *) mesh_element_iterator_next(&it);
886                 mesh_model_iterator_t model_it;
887                 mesh_model_iterator_init(&model_it, element);
888                 while (mesh_model_iterator_has_next(&model_it)){
889                     mesh_model_t * model = mesh_model_iterator_next(&model_it);
890                     if (mesh_model_contains_subscription(model, dst)){
891                         // find opcode in table
892                         const mesh_operation_t * operation = mesh_model_lookup_operation(model, pdu);
893                         if (operation == NULL) continue;
894                         if (mesh_access_validate_appkey_index(model, appkey_index) == 0) continue;
895                         mesh_access_acknowledged_received(src, opcode);
896                         operation->handler(model, pdu);
897                         return;
898                     }
899                 }
900             }
901         }
902     }
903 
904     // operation not found -> done
905     printf("Message not handled\n");
906     mesh_access_message_processed(pdu);
907 }
908 
909 void mesh_access_message_processed(mesh_pdu_t * pdu){
910     mesh_upper_transport_message_processed_by_higher_layer(pdu);
911 }
912 
913 // Mesh Model Publication
914 static btstack_timer_source_t mesh_access_publication_timer;
915 
916 static uint32_t mesh_model_publication_retransmit_count(uint8_t retransmit){
917     return retransmit & 0x07u;
918 }
919 
920 static uint32_t mesh_model_publication_retransmission_period_ms(uint8_t retransmit){
921     return ((uint32_t)((retransmit >> 3) + 1)) * 50;
922 }
923 
924 static void mesh_model_publication_setup_publication(mesh_publication_model_t * publication_model, uint32_t now){
925 
926     // set retransmit counter
927     publication_model->retransmit_count = mesh_model_publication_retransmit_count(publication_model->retransmit);
928 
929     // schedule next publication or retransmission
930     uint32_t publication_period_ms = mesh_access_time_gdtt2ms(publication_model->period);
931 
932     // set next publication
933     if (publication_period_ms != 0){
934         publication_model->next_publication_ms = now + publication_period_ms;
935         publication_model->state = MESH_MODEL_PUBLICATION_STATE_W4_PUBLICATION_MS;
936     } else {
937         publication_model->state = MESH_MODEL_PUBLICATION_STATE_IDLE;
938     }
939 }
940 
941 // assumes retransmit_count is valid
942 static void mesh_model_publication_setup_retransmission(mesh_publication_model_t * publication_model, uint32_t now){
943     uint32_t publication_period_ms = mesh_access_time_gdtt2ms(publication_model->period);
944 
945     // retransmission done
946     if (publication_model->retransmit_count == 0) {
947         // wait for next main event if periodic and retransmission complete
948         if (publication_period_ms != 0){
949             publication_model->state = MESH_MODEL_PUBLICATION_STATE_W4_PUBLICATION_MS;
950         } else {
951             publication_model->state = MESH_MODEL_PUBLICATION_STATE_IDLE;
952         }
953         return;
954     }
955 
956     // calc next retransmit time
957     uint32_t retransmission_ms = now + mesh_model_publication_retransmission_period_ms(publication_model->retransmit);
958 
959     // check next publication timeout is before next retransmission
960     if (publication_period_ms != 0){
961         if (btstack_time_delta(retransmission_ms, publication_model->next_publication_ms) > 0) return;
962     }
963 
964     // schedule next retransmission
965     publication_model->next_retransmit_ms = retransmission_ms;
966     publication_model->state = MESH_MODEL_PUBLICATION_STATE_W4_RETRANSMIT_MS;
967 }
968 
969 static void mesh_model_publication_publish_now_model(mesh_model_t * mesh_model){
970     mesh_publication_model_t * publication_model = mesh_model->publication_model;
971     if (publication_model == NULL) return;
972     if (publication_model->publish_state_fn == NULL) return;
973     uint16_t dest = publication_model->address;
974     if (dest == MESH_ADDRESS_UNSASSIGNED) return;
975     uint16_t appkey_index = publication_model->appkey_index;
976     mesh_transport_key_t * app_key = mesh_transport_key_get(appkey_index);
977     if (app_key == NULL) return;
978 
979     // compose message
980     mesh_pdu_t * pdu = (*publication_model->publish_state_fn)(mesh_model);
981     if (pdu == NULL) return;
982 
983     mesh_upper_transport_setup_access_pdu_header(pdu, app_key->netkey_index, appkey_index, publication_model->ttl, mesh_access_get_element_address(mesh_model), dest, 0);
984     mesh_upper_transport_send_access_pdu(pdu);
985 }
986 
987 static void mesh_model_publication_run(btstack_timer_source_t * ts){
988 
989     uint32_t now = btstack_run_loop_get_time_ms();
990 
991     // iterate over elements and models and handle time-based transitions
992     mesh_element_iterator_t element_it;
993     mesh_element_iterator_init(&element_it);
994     while (mesh_element_iterator_has_next(&element_it)){
995         mesh_element_t * element = mesh_element_iterator_next(&element_it);
996         mesh_model_iterator_t model_it;
997         mesh_model_iterator_init(&model_it, element);
998         while (mesh_model_iterator_has_next(&model_it)){
999             mesh_model_t * mesh_model = mesh_model_iterator_next(&model_it);
1000             mesh_publication_model_t * publication_model = mesh_model->publication_model;
1001             if (publication_model == NULL) continue;
1002 
1003             // check if either timer fired
1004             switch (publication_model->state){
1005                 case MESH_MODEL_PUBLICATION_STATE_W4_PUBLICATION_MS:
1006                     if (btstack_time_delta(publication_model->next_publication_ms, now) > 0) break;
1007                     publication_model->state = MESH_MODEL_PUBLICATION_STATE_PUBLICATION_READY;
1008                     break;
1009                 case MESH_MODEL_PUBLICATION_STATE_W4_RETRANSMIT_MS:
1010                     if (btstack_time_delta(publication_model->next_retransmit_ms, now) > 0) break;
1011                     publication_model->state = MESH_MODEL_PUBLICATION_STATE_RETRANSMIT_READY;
1012                     break;
1013                 default:
1014                     break;
1015             }
1016 
1017             switch (publication_model->state){
1018                 case MESH_MODEL_PUBLICATION_STATE_PUBLICATION_READY:
1019                     // schedule next publication and retransmission
1020                     mesh_model_publication_setup_publication(publication_model, now);
1021                     mesh_model_publication_setup_retransmission(publication_model, now);
1022                     mesh_model_publication_publish_now_model(mesh_model);
1023                     break;
1024                 case MESH_MODEL_PUBLICATION_STATE_RETRANSMIT_READY:
1025                     // schedule next retransmission
1026                     publication_model->retransmit_count--;
1027                     mesh_model_publication_setup_retransmission(publication_model, now);
1028                     mesh_model_publication_publish_now_model(mesh_model);
1029                     break;
1030                 default:
1031                     break;
1032             }
1033         }
1034     }
1035 
1036     int32_t next_timeout_ms = 0;
1037     mesh_element_iterator_init(&element_it);
1038     while (mesh_element_iterator_has_next(&element_it)){
1039         mesh_element_t * element = mesh_element_iterator_next(&element_it);
1040         mesh_model_iterator_t model_it;
1041         mesh_model_iterator_init(&model_it, element);
1042         while (mesh_model_iterator_has_next(&model_it)){
1043             mesh_model_t * mesh_model = mesh_model_iterator_next(&model_it);
1044             mesh_publication_model_t * publication_model = mesh_model->publication_model;
1045             if (publication_model == NULL) continue;
1046 
1047             // schedule next
1048             int32_t timeout_delta_ms;
1049             switch (publication_model->state){
1050                 case MESH_MODEL_PUBLICATION_STATE_W4_PUBLICATION_MS:
1051                     timeout_delta_ms = btstack_time_delta(publication_model->next_publication_ms, now);
1052                     if (next_timeout_ms == 0 || timeout_delta_ms < next_timeout_ms){
1053                         next_timeout_ms = timeout_delta_ms;
1054                     }
1055                     break;
1056                 case MESH_MODEL_PUBLICATION_STATE_W4_RETRANSMIT_MS:
1057                     timeout_delta_ms = btstack_time_delta(publication_model->next_retransmit_ms, now);
1058                     if (next_timeout_ms == 0 || timeout_delta_ms < next_timeout_ms){
1059                         next_timeout_ms = timeout_delta_ms;
1060                     }
1061                     break;
1062                 default:
1063                     break;
1064             }
1065         }
1066     }
1067 
1068     // remove current timer if active
1069     if (ts == NULL){
1070         btstack_run_loop_remove_timer(&mesh_access_publication_timer);
1071 
1072     }
1073 
1074     // new timeout?
1075     if (next_timeout_ms == 0) return;
1076 
1077     // set timer
1078     btstack_run_loop_set_timer(&mesh_access_publication_timer, next_timeout_ms);
1079     btstack_run_loop_set_timer_handler(&mesh_access_publication_timer, mesh_model_publication_run);
1080     btstack_run_loop_add_timer(&mesh_access_publication_timer);
1081 }
1082 
1083 void mesh_model_publication_start(mesh_model_t * mesh_model){
1084     mesh_publication_model_t * publication_model = mesh_model->publication_model;
1085     if (publication_model == NULL) return;
1086 
1087     // publish right away
1088     publication_model->state = MESH_MODEL_PUBLICATION_STATE_PUBLICATION_READY;
1089     mesh_model_publication_run(NULL);
1090 }
1091 
1092 void mesh_model_publication_stop(mesh_model_t * mesh_model){
1093     mesh_publication_model_t * publication_model = mesh_model->publication_model;
1094     if (publication_model == NULL) return;
1095 
1096     // reset state
1097     publication_model->state = MESH_MODEL_PUBLICATION_STATE_IDLE;
1098 }
1099 
1100 void mesh_access_state_changed(mesh_model_t * mesh_model){
1101     mesh_publication_model_t * publication_model = mesh_model->publication_model;
1102     if (publication_model == NULL) return;
1103     publication_model->state = MESH_MODEL_PUBLICATION_STATE_PUBLICATION_READY;
1104     mesh_model_publication_run(NULL);
1105 }
1106 
1107