xref: /btstack/src/mesh/mesh_network.c (revision 42c5c5581b83a00e2c1de42e4fe687a30b9efa5a)
1 /*
2  * Copyright (C) 2018 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__ "mesh_network.c"
39 
40 #include <inttypes.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include "btstack_debug.h"
46 #include "btstack_event.h"
47 #include "btstack_memory.h"
48 #include "btstack_util.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_keys.h"
54 #include "mesh/mesh_node.h"
55 #include "mesh/provisioning.h"
56 #include "mesh/provisioning_device.h"
57 
58 #ifdef ENABLE_MESH_ADV_BEARER
59 #include "mesh/adv_bearer.h"
60 #endif
61 
62 #ifdef ENABLE_MESH_GATT_BEARER
63 #include "mesh/gatt_bearer.h"
64 #endif
65 
66 // configuration
67 #define MESH_NETWORK_CACHE_SIZE 2
68 
69 // debug config
70 #define LOG_NETWORK
71 
72 static void mesh_network_dump_network_pdus(const char * name, btstack_linked_list_t * list);
73 
74 // structs
75 
76 // globals
77 
78 static void (*mesh_network_higher_layer_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu);
79 static void (*mesh_network_proxy_message_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu);
80 
81 #ifdef ENABLE_MESH_GATT_BEARER
82 static hci_con_handle_t gatt_bearer_con_handle;
83 #endif
84 
85 // shared send/receive crypto
86 static int mesh_crypto_active;
87 
88 // crypto requests
89 static union {
90     btstack_crypto_ccm_t         ccm;
91     btstack_crypto_aes128_t      aes128;
92 } mesh_network_crypto_request;
93 
94 static const mesh_network_key_t *  current_network_key;
95 
96 // PECB calculation
97 static uint8_t encryption_block[16];
98 static uint8_t obfuscation_block[16];
99 
100 // Subnets
101 static btstack_linked_list_t subnets;
102 
103 // Network Nonce
104 static uint8_t network_nonce[13];
105 
106 // INCOMING //
107 
108 // unprocessed network pdu - added by mesh_network_pdus_received_message
109 static btstack_linked_list_t        network_pdus_received;
110 
111 // in validation
112 static mesh_network_pdu_t *         incoming_pdu_raw;
113 static mesh_network_pdu_t *         incoming_pdu_decoded;
114 static mesh_network_key_iterator_t  validation_network_key_it;
115 
116 // OUTGOING //
117 
118 // Network PDUs queued by mesh_network_send
119 static btstack_linked_list_t network_pdus_queued;
120 
121 // Network PDU about to get send via all bearers when encrypted
122 static mesh_network_pdu_t * outgoing_pdu;
123 
124 // Network PDUs ready to send via GATT Bearer
125 static btstack_linked_list_t network_pdus_outgoing_gatt;
126 
127 #ifdef ENABLE_MESH_GATT_BEARER
128 static mesh_network_pdu_t * gatt_bearer_network_pdu;
129 #endif
130 
131 // Network PDUs ready to send via ADV Bearer
132 static btstack_linked_list_t network_pdus_outgoing_adv;
133 
134 #ifdef ENABLE_MESH_ADV_BEARER
135 static mesh_network_pdu_t * adv_bearer_network_pdu;
136 #endif
137 
138 
139 // mesh network cache - we use 32-bit 'hashes'
140 static uint32_t mesh_network_cache[MESH_NETWORK_CACHE_SIZE];
141 static int      mesh_network_cache_index;
142 
143 // register for freed network pdu
144 void (*mesh_network_free_pdu_callback)(void);
145 
146 // prototypes
147 
148 static void mesh_network_run(void);
149 static void process_network_pdu_validate(void);
150 
151 // network caching
152 static uint32_t mesh_network_cache_hash(mesh_network_pdu_t * network_pdu){
153     // - The SEQ field is a 24-bit integer that when combined with the IV Index,
154     // shall be a unique value for each new Network PDU originated by this node (=> SRC)
155     // - IV updates only rarely
156     // => 16 bit SRC, 1 bit IVI, 15 bit SEQ
157     uint8_t  ivi = network_pdu->data[0] >> 7;
158     uint16_t seq = big_endian_read_16(network_pdu->data, 3);
159     uint16_t src = big_endian_read_16(network_pdu->data, 5);
160     return (src << 16) | (ivi << 15) | (seq & 0x7fff);
161 }
162 
163 static int mesh_network_cache_find(uint32_t hash){
164     int i;
165     for (i = 0; i < MESH_NETWORK_CACHE_SIZE; i++) {
166         if (mesh_network_cache[i] == hash) {
167             return 1;
168         }
169     }
170     return 0;
171 }
172 
173 static void mesh_network_cache_add(uint32_t hash){
174     mesh_network_cache[mesh_network_cache_index++] = hash;
175     if (mesh_network_cache_index >= MESH_NETWORK_CACHE_SIZE){
176         mesh_network_cache_index = 0;
177     }
178 }
179 
180 // common helper
181 int mesh_network_address_unicast(uint16_t addr){
182     return addr != MESH_ADDRESS_UNSASSIGNED && (addr < 0x8000);
183 }
184 
185 int mesh_network_address_virtual(uint16_t addr){
186     return (addr & 0xC000) == 0x8000;   // 0b10xx xxxx xxxx xxxx
187 }
188 
189 int mesh_network_address_group(uint16_t addr){
190     return (addr & 0xC000) == 0xC000;   // 0b11xx xxxx xxxx xxxx
191 }
192 
193 int mesh_network_address_all_proxies(uint16_t addr){
194     return addr == MESH_ADDRESS_ALL_PROXIES;
195 }
196 
197 int mesh_network_address_all_nodes(uint16_t addr){
198     return addr == MESH_ADDRESS_ALL_NODES;
199 }
200 
201 int mesh_network_address_all_friends(uint16_t addr){
202     return addr == MESH_ADDRESS_ALL_FRIENDS;
203 }
204 
205 int mesh_network_address_all_relays(uint16_t addr){
206     return addr == MESH_ADDRESS_ALL_RELAYS;
207 }
208 
209 int mesh_network_addresses_valid(uint8_t ctl, uint16_t src, uint16_t dst){
210     // printf("CTL: %u\n", ctl);
211     // printf("SRC: %04x\n", src);
212     // printf("DST: %04x\n", dst);
213     if (src == 0){
214         // printf("SRC Unassigned Addr -> ignore\n");
215         return 0;
216     }
217     if ((src & 0xC000) == 0x8000){
218         // printf("SRC Virtual Addr -> ignore\n");
219         return 0;
220     }
221     if ((src & 0xC000) == 0xC000){
222         // printf("SRC Group Addr -> ignore\n");
223         return 0;
224     }
225     if (dst == 0){
226         // printf("DST Unassigned Addr -> ignore\n");
227         return 0;
228     }
229     if ( ((dst & 0xC000) == 0x8000) && (ctl == 1)){
230         // printf("DST Virtual Addr in CONTROL -> ignore\n");
231         return 0;
232     }
233     if ( (0xFF00 <= dst) && (dst <= 0xfffb) && (ctl == 0) ){
234         // printf("DST RFU Group Addr in MESSAGE -> ignore\n");
235         return 0;
236     }
237     // printf("SRC + DST Addr valid\n");
238     return 1;
239 }
240 
241 static void mesh_network_create_nonce(uint8_t * nonce, const mesh_network_pdu_t * pdu, uint32_t iv_index){
242     unsigned int pos = 0;
243     nonce[pos++] = 0x0;      // Network Nonce
244     (void)memcpy(&nonce[pos], &pdu->data[1], 6);
245     pos += 6;
246     big_endian_store_16(nonce, pos, 0);
247     pos += 2;
248     big_endian_store_32(nonce, pos, iv_index);
249 }
250 
251 static void mesh_proxy_create_nonce(uint8_t * nonce, const mesh_network_pdu_t * pdu, uint32_t iv_index){
252     unsigned int pos = 0;
253     nonce[pos++] = 0x3;      // Proxy Nonce
254     nonce[pos++] = 0;
255     (void)memcpy(&nonce[pos], &pdu->data[2], 5);
256     pos += 5;
257     big_endian_store_16(nonce, pos, 0);
258     pos += 2;
259     big_endian_store_32(nonce, pos, iv_index);
260 }
261 
262 // NID/IVI | obfuscated (CTL/TTL, SEQ (24), SRC (16) ), encrypted ( DST(16), TransportPDU), MIC(32 or 64)
263 
264 static void mesh_network_send_complete(mesh_network_pdu_t * network_pdu){
265     if (network_pdu->flags & MESH_NETWORK_PDU_FLAGS_RELAY){
266 #ifdef LOG_NETWORK
267         printf("TX-F-NetworkPDU (%p): relay -> free packet\n", network_pdu);
268 #endif
269         mesh_network_pdu_free(network_pdu);
270     } else {
271 #ifdef LOG_NETWORK
272         printf("TX-F-NetworkPDU (%p): notify lower transport\n", network_pdu);
273 #endif
274         // notify higher layer
275         (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_SENT, network_pdu);
276     }
277 }
278 
279 // new
280 static void mesh_network_send_c(void *arg){
281     UNUSED(arg);
282 
283     // obfuscate
284     unsigned int i;
285     for (i=0;i<6;i++){
286         outgoing_pdu->data[1+i] ^= obfuscation_block[i];
287     }
288 
289 #ifdef LOG_NETWORK
290     printf("TX-C-NetworkPDU (%p): ", outgoing_pdu);
291     printf_hexdump(outgoing_pdu->data, outgoing_pdu->len);
292 #endif
293 
294     // crypto done
295     mesh_crypto_active = 0;
296 
297     // done
298     mesh_network_pdu_t * network_pdu = outgoing_pdu;
299     outgoing_pdu = NULL;
300 
301     if ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION) != 0){
302         // encryption requested by mesh_network_encrypt_proxy_configuration_message
303         (*mesh_network_proxy_message_handler)(MESH_NETWORK_PDU_ENCRYPTED, network_pdu);
304         return;
305     }
306 
307 #ifdef LOG_NETWORK
308     printf("TX-D-NetworkPDU (%p): ", network_pdu);
309     printf_hexdump(network_pdu->data, network_pdu->len);
310 #endif
311 
312     // add to queue
313     btstack_linked_list_add_tail(&network_pdus_outgoing_gatt, (btstack_linked_item_t *) network_pdu);
314 
315     // go
316     mesh_network_run();
317 }
318 
319 static void mesh_network_send_b(void *arg){
320     UNUSED(arg);
321 
322     uint32_t iv_index = mesh_get_iv_index_for_tx();
323 
324     // store NetMIC
325     uint8_t net_mic[8];
326     btstack_crypto_ccm_get_authentication_value(&mesh_network_crypto_request.ccm, net_mic);
327 
328     // store MIC
329     uint8_t net_mic_len = outgoing_pdu->data[1] & 0x80 ? 8 : 4;
330     (void)memcpy(&outgoing_pdu->data[outgoing_pdu->len], net_mic, net_mic_len);
331     outgoing_pdu->len += net_mic_len;
332 
333     btstack_assert(outgoing_pdu->len <= 29);
334 
335 #ifdef LOG_NETWORK
336     printf("TX-B-NetworkPDU (%p): ", outgoing_pdu);
337     printf_hexdump(outgoing_pdu->data, outgoing_pdu->len);
338 #endif
339 
340     // calc PECB
341     memset(encryption_block, 0, 5);
342     big_endian_store_32(encryption_block, 5, iv_index);
343     (void)memcpy(&encryption_block[9], &outgoing_pdu->data[7], 7);
344     btstack_crypto_aes128_encrypt(&mesh_network_crypto_request.aes128, current_network_key->privacy_key, encryption_block, obfuscation_block, &mesh_network_send_c, NULL);
345 }
346 
347 static void mesh_network_send_a(void){
348 
349     mesh_crypto_active = 1;
350 
351     uint32_t iv_index = mesh_get_iv_index_for_tx();
352 
353     // lookup subnet by netkey_index
354     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(outgoing_pdu->netkey_index);
355     if (!subnet) {
356         mesh_crypto_active = 0;
357         mesh_network_pdu_t * network_pdu = outgoing_pdu;
358         outgoing_pdu = NULL;
359         // notify upper layer
360         mesh_network_send_complete(network_pdu);
361         // run again
362         mesh_network_run();
363         return;
364     }
365 
366     // get network key to use for sending
367     current_network_key = mesh_subnet_get_outgoing_network_key(subnet);
368 
369 #ifdef LOG_NETWORK
370     printf("TX-A-NetworkPDU (%p): ", outgoing_pdu);
371     printf_hexdump(outgoing_pdu->data, outgoing_pdu->len);
372 #endif
373 
374     // get network nonce
375     if (outgoing_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
376         mesh_proxy_create_nonce(network_nonce, outgoing_pdu, iv_index);
377 #ifdef LOG_NETWORK
378         printf("TX-ProxyNonce:  ");
379         printf_hexdump(network_nonce, 13);
380 #endif
381     } else {
382         mesh_network_create_nonce(network_nonce, outgoing_pdu, iv_index);
383 #ifdef LOG_NETWORK
384         printf("TX-NetworkNonce:  ");
385         printf_hexdump(network_nonce, 13);
386 #endif
387     }
388 
389 #ifdef LOG_NETWORK
390    printf("TX-EncryptionKey: ");
391     printf_hexdump(current_network_key->encryption_key, 16);
392 #endif
393 
394     // start ccm
395     uint8_t cypher_len  = outgoing_pdu->len - 7;
396     uint8_t net_mic_len = outgoing_pdu->data[1] & 0x80 ? 8 : 4;
397     btstack_crypto_ccm_init(&mesh_network_crypto_request.ccm, current_network_key->encryption_key, network_nonce, cypher_len, 0, net_mic_len);
398     btstack_crypto_ccm_encrypt_block(&mesh_network_crypto_request.ccm, cypher_len, &outgoing_pdu->data[7], &outgoing_pdu->data[7], &mesh_network_send_b, NULL);
399 }
400 
401 #if defined(ENABLE_MESH_RELAY) || defined (ENABLE_MESH_PROXY_SERVER)
402 static void mesh_network_relay_message(mesh_network_pdu_t * network_pdu){
403 
404     uint8_t ctl_ttl      = network_pdu->data[1];
405     uint8_t ctl_in_bit_7 = ctl_ttl & 0x80;
406     uint8_t ttl          = ctl_ttl & 0x7f;
407 
408     // prepare pdu for resending
409     network_pdu->data[1] = ctl_in_bit_7 | (ttl - 1);
410     network_pdu->flags |= MESH_NETWORK_PDU_FLAGS_RELAY;
411 
412 #ifdef LOG_NETWORK
413     printf("TX-Relay-NetworkPDU (%p): ", network_pdu);
414     printf_hexdump(network_pdu->data, network_pdu->len);
415     printf("^^ into network_pdus_queued\n");
416 #endif
417 
418     uint8_t net_mic_len = ctl_in_bit_7 ? 8 : 4;
419     btstack_assert((network_pdu->len + net_mic_len) <= 29);
420     UNUSED(net_mic_len);
421 
422     // queue up
423     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
424 }
425 #endif
426 
427 void mesh_network_message_processed_by_higher_layer(mesh_network_pdu_t * network_pdu){
428 
429 #if defined(ENABLE_MESH_RELAY) || defined (ENABLE_MESH_PROXY_SERVER)
430 
431     // check if address does not matches elements on our node and TTL >= 2
432     uint16_t src     = mesh_network_src(network_pdu);
433     uint8_t  ttl     = mesh_network_ttl(network_pdu);
434 
435     uint16_t mesh_network_primary_address = mesh_node_get_primary_element_address();
436 
437     if (((src < mesh_network_primary_address) || (src > (mesh_network_primary_address + mesh_node_element_count()))) && (ttl >= 2)){
438 
439         if ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0){
440 
441             // message received via ADV bearer are relayed:
442 
443 #ifdef ENABLE_MESH_RELAY
444             if (mesh_foundation_relay_get() != 0){
445                 // - to ADV bearer, if Relay supported and enabledx
446                 mesh_network_relay_message(network_pdu);
447                 mesh_network_run();
448                 return;
449             }
450 #endif
451 
452 #ifdef ENABLE_MESH_PROXY_SERVER
453             if (mesh_foundation_gatt_proxy_get() != 0){
454                 // - to GATT bearer, if Proxy supported and enabled
455                 mesh_network_relay_message(network_pdu);
456                 mesh_network_run();
457                 return;
458             }
459 #endif
460 
461         } else {
462 
463             // messages received via GATT bearer are relayed:
464 
465 #ifdef ENABLE_MESH_PROXY_SERVER
466             if (mesh_foundation_gatt_proxy_get() != 0){
467                 // - to ADV bearer, if Proxy supported and enabled
468                 mesh_network_relay_message(network_pdu);
469                 mesh_network_run();
470                 return;
471             }
472 #endif
473 
474         }
475     }
476 #endif
477 
478     // otherwise, we're done
479     btstack_memory_mesh_network_pdu_free(network_pdu);
480 }
481 
482 static void process_network_pdu_done(void){
483     btstack_memory_mesh_network_pdu_free(incoming_pdu_raw);
484     incoming_pdu_raw = NULL;
485     mesh_crypto_active = 0;
486 
487     mesh_network_run();
488 }
489 
490 static void process_network_pdu_validate_d(void * arg){
491     UNUSED(arg);
492     // mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
493 
494     uint8_t ctl_ttl     = incoming_pdu_decoded->data[1];
495     uint8_t ctl         = ctl_ttl >> 7;
496     uint8_t net_mic_len = (ctl_ttl & 0x80) ? 8 : 4;
497 
498     // store NetMIC
499     uint8_t net_mic[8];
500     btstack_crypto_ccm_get_authentication_value(&mesh_network_crypto_request.ccm, net_mic);
501 #ifdef LOG_NETWORK
502     printf("RX-NetMIC (%p): ", incoming_pdu_decoded);
503     printf_hexdump(net_mic, net_mic_len);
504 #endif
505     // store in decoded pdu
506     (void)memcpy(&incoming_pdu_decoded->data[incoming_pdu_decoded->len - net_mic_len],
507                  net_mic, net_mic_len);
508 
509 #ifdef LOG_NETWORK
510     uint8_t cypher_len  = incoming_pdu_decoded->len - 9 - net_mic_len;
511     printf("RX-Decrypted DST/TransportPDU (%p): ", incoming_pdu_decoded);
512     printf_hexdump(&incoming_pdu_decoded->data[7], 2 + cypher_len);
513 
514     printf("RX-Decrypted: ");
515     printf_hexdump(incoming_pdu_decoded->data, incoming_pdu_decoded->len);
516 #endif
517 
518     // validate network mic
519     if (memcmp(net_mic, &incoming_pdu_raw->data[incoming_pdu_decoded->len-net_mic_len], net_mic_len) != 0){
520         // fail
521         printf("RX-NetMIC mismatch, try next key (%p)\n", incoming_pdu_decoded);
522         process_network_pdu_validate();
523         return;
524     }
525 
526     // remove NetMIC from payload
527     incoming_pdu_decoded->len -= net_mic_len;
528 
529 #ifdef LOG_NETWORK
530     // match
531     printf("RX-NetMIC matches (%p)\n", incoming_pdu_decoded);
532     printf("RX-TTL (%p): 0x%02x\n", incoming_pdu_decoded, incoming_pdu_decoded->data[1] & 0x7f);
533 #endif
534 
535     // set netkey_index
536     incoming_pdu_decoded->netkey_index = current_network_key->netkey_index;
537 
538     if (incoming_pdu_decoded->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
539 
540         mesh_network_pdu_t * decoded_pdu = incoming_pdu_decoded;
541         incoming_pdu_decoded = NULL;
542 
543         // no additional checks for proxy messages
544         (*mesh_network_proxy_message_handler)(MESH_NETWORK_PDU_RECEIVED, decoded_pdu);
545 
546     } else {
547 
548         // validate src/dest addresses
549         uint16_t src = big_endian_read_16(incoming_pdu_decoded->data, 5);
550         uint16_t dst = big_endian_read_16(incoming_pdu_decoded->data, 7);
551         int valid = mesh_network_addresses_valid(ctl, src, dst);
552         if (!valid){
553 #ifdef LOG_NETWORK
554             printf("RX Address invalid (%p)\n", incoming_pdu_decoded);
555 #endif
556             btstack_memory_mesh_network_pdu_free(incoming_pdu_decoded);
557             incoming_pdu_decoded = NULL;
558             process_network_pdu_done();
559             return;
560         }
561 
562         // check cache
563         uint32_t hash = mesh_network_cache_hash(incoming_pdu_decoded);
564 #ifdef LOG_NETWORK
565         printf("RX-Hash (%p): %08" PRIx32 "\n", incoming_pdu_decoded, hash);
566 #endif
567         if (mesh_network_cache_find(hash)){
568             // found in cache, drop
569 #ifdef LOG_NETWORK
570             printf("Found in cache -> drop packet (%p)\n", incoming_pdu_decoded);
571 #endif
572             btstack_memory_mesh_network_pdu_free(incoming_pdu_decoded);
573             incoming_pdu_decoded = NULL;
574             process_network_pdu_done();
575             return;
576         }
577 
578         // store in network cache
579         mesh_network_cache_add(hash);
580 
581 #ifdef LOG_NETWORK
582             printf("RX-Validated (%p) - forward to lower transport\n", incoming_pdu_decoded);
583 #endif
584 
585         // forward to lower transport layer. message is freed by call to mesh_network_message_processed_by_upper_layer
586         mesh_network_pdu_t * decoded_pdu = incoming_pdu_decoded;
587         incoming_pdu_decoded = NULL;
588         (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_RECEIVED, decoded_pdu);
589     }
590 
591     // done
592     process_network_pdu_done();
593 }
594 
595 static uint32_t iv_index_for_pdu(const mesh_network_pdu_t * network_pdu){
596     // get IV Index and IVI
597     uint32_t iv_index = mesh_get_iv_index();
598     int ivi = network_pdu->data[0] >> 7;
599 
600     // if least significant bit differs, use previous IV Index
601     if ((iv_index & 1 ) ^ ivi){
602         iv_index--;
603 #ifdef LOG_NETWORK
604         printf("RX-IV: IVI indicates previous IV index, using 0x%08" PRIx32 "\n", iv_index);
605 #endif
606     }
607     return iv_index;
608 }
609 
610 static void process_network_pdu_validate_b(void * arg){
611     UNUSED(arg);
612 
613 #ifdef LOG_NETWORK
614     printf("RX-PECB: ");
615     printf_hexdump(obfuscation_block, 6);
616 #endif
617 
618     // de-obfuscate
619     unsigned int i;
620     for (i=0;i<6;i++){
621         incoming_pdu_decoded->data[1+i] = incoming_pdu_raw->data[1+i] ^ obfuscation_block[i];
622     }
623 
624     uint32_t iv_index = iv_index_for_pdu(incoming_pdu_raw);
625 
626     if (incoming_pdu_decoded->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
627         // create network nonce
628         mesh_proxy_create_nonce(network_nonce, incoming_pdu_decoded, iv_index);
629 #ifdef LOG_NETWORK
630         printf("RX-Proxy Nonce: ");
631         printf_hexdump(network_nonce, 13);
632 #endif
633     } else {
634         // create network nonce
635         mesh_network_create_nonce(network_nonce, incoming_pdu_decoded, iv_index);
636 #ifdef LOG_NETWORK
637         printf("RX-Network Nonce: ");
638         printf_hexdump(network_nonce, 13);
639 #endif
640     }
641 
642     //
643     uint8_t ctl_ttl     = incoming_pdu_decoded->data[1];
644     uint8_t net_mic_len = (ctl_ttl & 0x80) ? 8 : 4;
645     uint8_t cypher_len  = incoming_pdu_decoded->len - 7 - net_mic_len;
646 
647 #ifdef LOG_NETWORK
648     printf("RX-Cyper len %u, mic len %u\n", cypher_len, net_mic_len);
649 
650     printf("RX-Encryption Key: ");
651     printf_hexdump(current_network_key->encryption_key, 16);
652 
653 #endif
654 
655     btstack_crypto_ccm_init(&mesh_network_crypto_request.ccm, current_network_key->encryption_key, network_nonce, cypher_len, 0, net_mic_len);
656     btstack_crypto_ccm_decrypt_block(&mesh_network_crypto_request.ccm, cypher_len, &incoming_pdu_raw->data[7], &incoming_pdu_decoded->data[7], &process_network_pdu_validate_d, incoming_pdu_decoded);
657 }
658 
659 static void process_network_pdu_validate(void){
660     if (!mesh_network_key_nid_iterator_has_more(&validation_network_key_it)){
661         printf("No valid network key found\n");
662         btstack_memory_mesh_network_pdu_free(incoming_pdu_decoded);
663         incoming_pdu_decoded = NULL;
664         process_network_pdu_done();
665         return;
666     }
667 
668     current_network_key = mesh_network_key_nid_iterator_get_next(&validation_network_key_it);
669 
670     // calc PECB
671     uint32_t iv_index = iv_index_for_pdu(incoming_pdu_raw);
672     memset(encryption_block, 0, 5);
673     big_endian_store_32(encryption_block, 5, iv_index);
674     (void)memcpy(&encryption_block[9], &incoming_pdu_raw->data[7], 7);
675     btstack_crypto_aes128_encrypt(&mesh_network_crypto_request.aes128, current_network_key->privacy_key, encryption_block, obfuscation_block, &process_network_pdu_validate_b, NULL);
676 }
677 
678 
679 static void process_network_pdu(void){
680     //
681     uint8_t nid_ivi = incoming_pdu_raw->data[0];
682 
683     // setup pdu object
684     incoming_pdu_decoded->data[0] = nid_ivi;
685     incoming_pdu_decoded->len     = incoming_pdu_raw->len;
686     incoming_pdu_decoded->flags   = incoming_pdu_raw->flags;
687 
688     // init provisioning data iterator
689     uint8_t nid = nid_ivi & 0x7f;
690     // uint8_t iv_index = network_pdu_data[0] >> 7;
691     mesh_network_key_nid_iterator_init(&validation_network_key_it, nid);
692 
693     process_network_pdu_validate();
694 }
695 
696 // returns true if done
697 static bool mesh_network_run_gatt(void){
698     if (btstack_linked_list_empty(&network_pdus_outgoing_gatt)){
699         return true;
700     }
701 
702 #ifdef ENABLE_MESH_GATT_BEARER
703     if (gatt_bearer_network_pdu != NULL){
704         return true;
705     }
706 
707     // move to 'gatt bearer queue'
708     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_gatt);
709 
710 #ifdef LOG_NETWORK
711     printf("network run 1: pop %p from network_pdus_outgoing_gatt\n", network_pdu);
712 #endif
713     // request to send via gatt if:
714     // proxy active and connected
715     // packet wasn't received via gatt bearer
716     int send_via_gatt = ((mesh_foundation_gatt_proxy_get() != 0) &&
717                         (gatt_bearer_con_handle != HCI_CON_HANDLE_INVALID) &&
718                         ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0));
719     if (send_via_gatt){
720 
721 #ifdef LOG_NETWORK
722         printf("network run 2: set %p as gatt_bearer_network_pdu\n", network_pdu);
723 #endif
724         gatt_bearer_network_pdu = network_pdu;
725         gatt_bearer_request_can_send_now_for_network_pdu();
726 
727     } else {
728 
729 #ifdef LOG_NETWORK
730         printf("network run 3: push %p to network_pdus_outgoing_adv\n", network_pdu);
731 #endif
732         btstack_linked_list_add_tail(&network_pdus_outgoing_adv, (btstack_linked_item_t *) network_pdu);
733 
734 #ifdef LOG_NETWORK
735         mesh_network_dump_network_pdus("network_pdus_outgoing_adv (1)", &network_pdus_outgoing_adv);
736 #endif
737     }
738 #else
739     // directly move to 'outgoing adv bearer queue'
740     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_gatt);
741     btstack_linked_list_add_tail(&network_pdus_outgoing_adv, (btstack_linked_item_t *) network_pdu);
742 #endif
743     return false;
744 }
745 
746 // returns true if done
747 static bool mesh_network_run_adv(void){
748 
749     if (btstack_linked_list_empty(&network_pdus_outgoing_adv)){
750         return true;
751     }
752 
753 #ifdef ENABLE_MESH_ADV_BEARER
754     if (adv_bearer_network_pdu != NULL){
755         return true;
756     }
757 
758     // move to 'adv bearer queue'
759     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_adv);
760 
761 #ifdef LOG_NETWORK
762     printf("network run 4: pop %p from network_pdus_outgoing_adv\n", network_pdu);
763     mesh_network_dump_network_pdus("network_pdus_outgoing_adv (3)", &network_pdus_outgoing_adv);
764     printf("network run 5: %p -> flags 0x%02x, gatt_proxy %u, relay %u\n", network_pdu, network_pdu->flags, mesh_foundation_gatt_proxy_get(), mesh_foundation_relay_get());
765 #endif
766 
767     // send via adv if:
768     // packet was received via gatt bearer and proxy active, or,
769     // packet originated locally (== not relayed), or,
770     // packet was received via ADV bearer and relay is active, or,
771     int send_via_adv = (((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) != 0) && (mesh_foundation_gatt_proxy_get() == 1)) ||
772                        (((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0) && (mesh_foundation_relay_get() == 1)) ||
773                         ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_RELAY) == 0);
774 
775     if (send_via_adv){
776 #ifdef LOG_NETWORK
777         printf("network run 6: set %p as to adv_bearer_network_pdu\n", network_pdu);
778 #endif
779         adv_bearer_network_pdu = network_pdu;
780         adv_bearer_request_can_send_now_for_network_pdu();
781     } else {
782 #ifdef LOG_NETWORK
783         printf("network run 7: skip sending %p via adv bearer\n", network_pdu);
784         #endif
785         // directly notify upper layer
786         mesh_network_send_complete(network_pdu);
787     }
788 #else
789     // done
790     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_adv);
791     // directly notify upper layer
792     mesh_network_send_complete(network_pdu);
793 #endif
794     return false;
795 }
796 
797 // returns true if done
798 static bool mesh_network_run_received(void){
799     if (mesh_crypto_active) {
800         return true;
801     }
802 
803     if (btstack_linked_list_empty(&network_pdus_received)) {
804         return true;
805     }
806 
807     incoming_pdu_decoded = mesh_network_pdu_get();
808     if (incoming_pdu_decoded == NULL) return true;
809 
810     // get encoded network pdu and start processing
811     mesh_crypto_active = 1;
812     incoming_pdu_raw = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_received);
813     process_network_pdu();
814     return true;
815 }
816 
817 // returns true if done
818 static bool mesh_network_run_queued(void){
819     if (mesh_crypto_active) {
820         return true;
821     }
822 
823     if (btstack_linked_list_empty(&network_pdus_queued)){
824         return true;
825     }
826 
827     // get queued network pdu and start processing
828     outgoing_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_queued);
829 
830 #ifdef LOG_NETWORK
831     printf("network run 5: pop %p from network_pdus_queued\n", outgoing_pdu);
832     mesh_network_dump_network_pdus("network_pdus_queued (2)", &network_pdus_queued);
833 #endif
834     mesh_network_send_a();
835     return true;
836 }
837 
838 static void mesh_network_run(void){
839     while (true){
840         bool done = true;
841         done &= mesh_network_run_gatt();
842         done &= mesh_network_run_adv();
843         done &= mesh_network_run_received();
844         done &= mesh_network_run_queued();
845         if (done) break;
846     }
847 }
848 
849 #ifdef ENABLE_MESH_ADV_BEARER
850 static void mesh_adv_bearer_handle_network_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
851     UNUSED(channel);
852     mesh_network_pdu_t * network_pdu;
853     uint8_t  transmission_count;
854     uint16_t transmission_interval;
855     uint8_t  transmit_config;
856 
857     switch (packet_type){
858         case MESH_NETWORK_PACKET:
859             // check len. minimal transport PDU len = 1, 32 bit NetMIC -> 13 bytes
860             if (size < 13) break;
861 
862 #ifdef LOG_NETWORK
863             printf("received network pdu from adv (len %u): ", size);
864             printf_hexdump(packet, size);
865 #endif
866             mesh_network_received_message(packet, size, 0);
867             break;
868 
869         case HCI_EVENT_PACKET:
870             if (hci_event_packet_get_type(packet) != HCI_EVENT_MESH_META) break;
871 
872             switch(hci_event_mesh_meta_get_subevent_code(packet)){
873                 case MESH_SUBEVENT_CAN_SEND_NOW:
874                     if (adv_bearer_network_pdu == NULL) break;
875 
876                     // Get Transmission config depending on relay flag
877                     if (adv_bearer_network_pdu->flags & MESH_NETWORK_PDU_FLAGS_RELAY){
878                         transmit_config = mesh_foundation_relay_get();
879                     } else {
880                         transmit_config = mesh_foundation_network_transmit_get();
881                     }
882                     transmission_count     = (transmit_config & 0x07) + 1;
883                     transmission_interval = (transmit_config >> 3) * 10;
884 
885 #ifdef LOG_NETWORK
886                     printf("TX-E-NetworkPDU (%p) count %u, interval %u ms: ", adv_bearer_network_pdu, transmission_count, transmission_interval);
887                     printf_hexdump(adv_bearer_network_pdu->data, adv_bearer_network_pdu->len);
888 #endif
889 
890                     adv_bearer_send_network_pdu(adv_bearer_network_pdu->data, adv_bearer_network_pdu->len, transmission_count, transmission_interval);
891                     network_pdu = adv_bearer_network_pdu;
892                     adv_bearer_network_pdu = NULL;
893 
894                     // notify upper layer
895                     mesh_network_send_complete(network_pdu);
896 
897                     // check if more to send
898                     mesh_network_run();
899                     break;
900                 default:
901                     break;
902             }
903             break;
904         default:
905             break;
906     }
907 }
908 #endif
909 
910 #ifdef ENABLE_MESH_GATT_BEARER
911 static void mesh_network_gatt_bearer_outgoing_complete(void){
912 
913     if (gatt_bearer_network_pdu == NULL) return;
914 
915     // forward to adv bearer
916     btstack_linked_list_add_tail(&network_pdus_outgoing_adv, (btstack_linked_item_t*) gatt_bearer_network_pdu);
917     gatt_bearer_network_pdu = NULL;
918 
919     mesh_network_run();
920     return;
921 }
922 
923 static void mesh_network_gatt_bearer_handle_network_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
924     UNUSED(channel);
925     switch (packet_type){
926         case MESH_PROXY_DATA_PACKET:
927             if (mesh_foundation_gatt_proxy_get() == 0) break;
928 #ifdef LOG_NETWORK
929             printf("received network pdu from gatt (len %u): ", size);
930             printf_hexdump(packet, size);
931 #endif
932             mesh_network_received_message(packet, size, MESH_NETWORK_PDU_FLAGS_GATT_BEARER);
933             break;
934         case HCI_EVENT_PACKET:
935             switch (hci_event_packet_get_type(packet)){
936                 case HCI_EVENT_MESH_META:
937                     switch (hci_event_mesh_meta_get_subevent_code(packet)){
938                         case MESH_SUBEVENT_PROXY_CONNECTED:
939                             gatt_bearer_con_handle = mesh_subevent_proxy_connected_get_con_handle(packet);
940                             break;
941                         case MESH_SUBEVENT_PROXY_DISCONNECTED:
942                             gatt_bearer_con_handle = HCI_CON_HANDLE_INVALID;
943                             mesh_network_gatt_bearer_outgoing_complete();
944                             break;
945                         case MESH_SUBEVENT_CAN_SEND_NOW:
946                             if (gatt_bearer_network_pdu == NULL) break;
947 #ifdef LOG_NETWORK
948                             printf("G-TX-E-NetworkPDU (%p): ", gatt_bearer_network_pdu);
949                             printf_hexdump(gatt_bearer_network_pdu->data, gatt_bearer_network_pdu->len);
950 #endif
951                             gatt_bearer_send_network_pdu(gatt_bearer_network_pdu->data, gatt_bearer_network_pdu->len);
952                             break;
953 
954                         case MESH_SUBEVENT_MESSAGE_SENT:
955                             mesh_network_gatt_bearer_outgoing_complete();
956                             break;
957                         default:
958                             break;
959                     }
960                     break;
961                 default:
962                     break;
963             }
964             break;
965         default:
966             break;
967     }
968 }
969 #endif
970 
971 #ifdef ENABLE_MESH_GATT_BEARER
972 static void mesh_netework_gatt_bearer_handle_proxy_configuration(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
973     UNUSED(channel);
974     switch (packet_type){
975         case MESH_PROXY_DATA_PACKET:
976             mesh_network_process_proxy_configuration_message(packet, size);
977             break;
978         case HCI_EVENT_PACKET:
979             switch (hci_event_packet_get_type(packet)){
980                 case HCI_EVENT_MESH_META:
981                     switch (hci_event_mesh_meta_get_subevent_code(packet)){
982                         case MESH_SUBEVENT_CAN_SEND_NOW:
983                             // forward to higher layer
984                             (*mesh_network_proxy_message_handler)(MESH_NETWORK_CAN_SEND_NOW, NULL);
985                             break;
986                         default:
987                             break;
988                     }
989                     break;
990                 default:
991                     break;
992             }
993             break;
994         default:
995             break;
996     }
997 }
998 #endif
999 
1000 void mesh_network_init(void){
1001 #ifdef ENABLE_MESH_ADV_BEARER
1002     adv_bearer_register_for_network_pdu(&mesh_adv_bearer_handle_network_event);
1003 #endif
1004 #ifdef ENABLE_MESH_GATT_BEARER
1005     gatt_bearer_con_handle = HCI_CON_HANDLE_INVALID;
1006     gatt_bearer_register_for_network_pdu(&mesh_network_gatt_bearer_handle_network_event);
1007     gatt_bearer_register_for_mesh_proxy_configuration(&mesh_netework_gatt_bearer_handle_proxy_configuration);
1008 #endif
1009 }
1010 
1011 void mesh_network_set_higher_layer_handler(void (*packet_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu)){
1012     mesh_network_higher_layer_handler = packet_handler;
1013 }
1014 
1015 void mesh_network_set_proxy_message_handler(void (*packet_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu)){
1016     mesh_network_proxy_message_handler = packet_handler;
1017 }
1018 
1019 void mesh_network_received_message(const uint8_t * pdu_data, uint8_t pdu_len, uint8_t flags){
1020     // verify len
1021     if (pdu_len > 29) return;
1022 
1023     // allocate network_pdu
1024     mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1025     if (!network_pdu) return;
1026 
1027     // store data
1028     (void)memcpy(network_pdu->data, pdu_data, pdu_len);
1029     network_pdu->len = pdu_len;
1030     network_pdu->flags = flags;
1031 
1032     // add to list and go
1033     btstack_linked_list_add_tail(&network_pdus_received, (btstack_linked_item_t *) network_pdu);
1034     mesh_network_run();
1035 
1036 }
1037 
1038 void mesh_network_process_proxy_configuration_message(const uint8_t * pdu_data, uint8_t pdu_len){
1039     // verify len
1040     if (pdu_len > 29) return;
1041 
1042     // allocate network_pdu
1043     mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1044     if (!network_pdu) return;
1045 
1046     // store data
1047     (void)memcpy(network_pdu->data, pdu_data, pdu_len);
1048     network_pdu->len = pdu_len;
1049     network_pdu->flags = MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION; // Network PDU
1050 
1051     // add to list and go
1052     btstack_linked_list_add_tail(&network_pdus_received, (btstack_linked_item_t *) network_pdu);
1053     mesh_network_run();
1054 }
1055 
1056 void mesh_network_send_pdu(mesh_network_pdu_t * network_pdu){
1057 #ifdef LOG_NETWORK
1058     printf("TX-NetworkPDU (%p):   ", network_pdu);
1059     printf_hexdump(network_pdu->data, network_pdu->len);
1060     printf("^^ into network_pdus_queued\n");
1061 #endif
1062 
1063     btstack_assert((network_pdu->len + (network_pdu->data[1] & 0x80 ? 8 : 4)) <= 29);
1064     btstack_assert(network_pdu->len >= 9);
1065 
1066     // setup callback
1067     network_pdu->flags    = 0;
1068 
1069     // queue up
1070     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
1071 #ifdef LOG_NETWORK
1072     mesh_network_dump_network_pdus("network_pdus_queued", &network_pdus_queued);
1073 #endif
1074 
1075     // go
1076     mesh_network_run();
1077 }
1078 
1079 void mesh_network_encrypt_proxy_configuration_message(mesh_network_pdu_t * network_pdu){
1080     printf("ProxyPDU(unencrypted): ");
1081     printf_hexdump(network_pdu->data, network_pdu->len);
1082 
1083     // setup callback
1084     network_pdu->flags    = MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION;
1085 
1086     // queue up
1087     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
1088 
1089     // go
1090     mesh_network_run();
1091 }
1092 
1093 /*
1094  * @brief Setup network pdu header
1095  * @param netkey_index
1096  * @param ctl
1097  * @param ttl
1098  * @param seq
1099  * @param dest
1100  */
1101 void mesh_network_setup_pdu(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint8_t nid, uint8_t ctl, uint8_t ttl, uint32_t seq, uint16_t src, uint16_t dest, const uint8_t * transport_pdu_data, uint8_t transport_pdu_len){
1102     // set netkey_index
1103     network_pdu->netkey_index = netkey_index;
1104     // setup header
1105     network_pdu->len = 0;
1106     network_pdu->data[network_pdu->len++] = (mesh_get_iv_index_for_tx() << 7) |  nid;
1107     uint8_t ctl_ttl = (ctl << 7) | (ttl & 0x7f);
1108     network_pdu->data[network_pdu->len++] = ctl_ttl;
1109     big_endian_store_24(network_pdu->data, 2, seq);
1110     network_pdu->len += 3;
1111     big_endian_store_16(network_pdu->data, network_pdu->len, src);
1112     network_pdu->len += 2;
1113     big_endian_store_16(network_pdu->data, network_pdu->len, dest);
1114     network_pdu->len += 2;
1115     btstack_assert((network_pdu->len + transport_pdu_len) <= MESH_NETWORK_PAYLOAD_MAX);
1116     (void)memcpy(&network_pdu->data[network_pdu->len], transport_pdu_data,
1117                  transport_pdu_len);
1118     network_pdu->len += transport_pdu_len;
1119     // zero rest of packet
1120     memset(&network_pdu->data[network_pdu->len], 0, MESH_NETWORK_PAYLOAD_MAX - network_pdu->len);
1121 }
1122 
1123 /*
1124  * @brief Setup network pdu header
1125  * @param netkey_index
1126  * @param ctl
1127  * @param ttl
1128  * @param seq
1129  * @param dest
1130  */
1131 void mesh_network_setup_pdu_header(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint8_t nid, uint8_t ctl, uint8_t ttl, uint32_t seq, uint16_t src, uint16_t dest){
1132     // set netkey_index
1133     network_pdu->netkey_index = netkey_index;
1134     // setup header
1135     network_pdu->data[0] = (mesh_get_iv_index_for_tx() << 7) |  nid;
1136     uint8_t ctl_ttl = (ctl << 7) | (ttl & 0x7f);
1137     network_pdu->data[1] = ctl_ttl;
1138     big_endian_store_24(network_pdu->data, 2, seq);
1139     big_endian_store_16(network_pdu->data, 5, src);
1140     big_endian_store_16(network_pdu->data, 7, dest);
1141 }
1142 
1143 // Network PDU Getter
1144 uint8_t  mesh_network_nid(mesh_network_pdu_t * network_pdu){
1145     return network_pdu->data[0] & 0x7f;
1146 }
1147 uint16_t mesh_network_control(mesh_network_pdu_t * network_pdu){
1148     return network_pdu->data[1] & 0x80;
1149 }
1150 uint8_t mesh_network_ttl(mesh_network_pdu_t * network_pdu){
1151     return network_pdu->data[1] & 0x7f;
1152 }
1153 uint32_t mesh_network_seq(mesh_network_pdu_t * network_pdu){
1154     return big_endian_read_24(network_pdu->data, 2);
1155 }
1156 uint16_t mesh_network_src(mesh_network_pdu_t * network_pdu){
1157     return big_endian_read_16(network_pdu->data, 5);
1158 }
1159 uint16_t mesh_network_dst(mesh_network_pdu_t * network_pdu){
1160     return big_endian_read_16(network_pdu->data, 7);
1161 }
1162 int mesh_network_segmented(mesh_network_pdu_t * network_pdu){
1163     return network_pdu->data[9] & 0x80;
1164 }
1165 uint8_t mesh_network_control_opcode(mesh_network_pdu_t * network_pdu){
1166     return network_pdu->data[9] & 0x7f;
1167 }
1168 uint8_t * mesh_network_pdu_data(mesh_network_pdu_t * network_pdu){
1169     return &network_pdu->data[9];
1170 }
1171 uint8_t   mesh_network_pdu_len(mesh_network_pdu_t * network_pdu){
1172     return network_pdu->len - 9;
1173 }
1174 
1175 void mesh_network_pdu_set_seq(mesh_network_pdu_t * network_pdu, uint32_t seq){
1176     big_endian_store_24(network_pdu->data, 2, seq);
1177 }
1178 
1179 static void mesh_network_dump_network_pdu(mesh_network_pdu_t * network_pdu){
1180     if (network_pdu){
1181         printf("- %p: ", network_pdu); printf_hexdump(network_pdu->data, network_pdu->len);
1182     }
1183 }
1184 static void mesh_network_dump_network_pdus(const char * name, btstack_linked_list_t * list){
1185     printf("List: %s:\n", name);
1186     btstack_linked_list_iterator_t it;
1187     btstack_linked_list_iterator_init(&it, list);
1188     while (btstack_linked_list_iterator_has_next(&it)){
1189         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t*) btstack_linked_list_iterator_next(&it);
1190         mesh_network_dump_network_pdu(network_pdu);
1191     }
1192 }
1193 static void mesh_network_reset_network_pdus(btstack_linked_list_t * list){
1194     while (!btstack_linked_list_empty(list)){
1195         mesh_network_pdu_t * pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(list);
1196         btstack_memory_mesh_network_pdu_free(pdu);
1197     }
1198 }
1199 void mesh_network_dump(void){
1200     mesh_network_dump_network_pdus("network_pdus_received", &network_pdus_received);
1201     mesh_network_dump_network_pdus("network_pdus_queued", &network_pdus_queued);
1202     mesh_network_dump_network_pdus("network_pdus_outgoing_gatt", &network_pdus_outgoing_gatt);
1203     mesh_network_dump_network_pdus("network_pdus_outgoing_adv", &network_pdus_outgoing_adv);
1204     printf("outgoing_pdu: \n");
1205     mesh_network_dump_network_pdu(outgoing_pdu);
1206     printf("incoming_pdu_raw: \n");
1207     mesh_network_dump_network_pdu(incoming_pdu_raw);
1208 #ifdef ENABLE_MESH_GATT_BEARER
1209     printf("gatt_bearer_network_pdu: \n");
1210     mesh_network_dump_network_pdu(gatt_bearer_network_pdu);
1211 #endif
1212 #ifdef ENABLE_MESH_ADV_BEARER
1213     printf("adv_bearer_network_pdu: \n");
1214     mesh_network_dump_network_pdu(adv_bearer_network_pdu);
1215 #endif
1216 
1217 }
1218 void mesh_network_reset(void){
1219     mesh_network_reset_network_pdus(&network_pdus_received);
1220     mesh_network_reset_network_pdus(&network_pdus_queued);
1221     mesh_network_reset_network_pdus(&network_pdus_outgoing_gatt);
1222     mesh_network_reset_network_pdus(&network_pdus_outgoing_adv);
1223 
1224     // outgoing network pdus are owned by higher layer, so we don't free:
1225     // - adv_bearer_network_pdu
1226     // - gatt_bearer_network_pdu
1227     // - outoing_pdu
1228     // unless they are SEG ACK messages
1229 #ifdef ENABLE_MESH_ADV_BEARER
1230     if ((adv_bearer_network_pdu != NULL) && (adv_bearer_network_pdu->pdu_header.pdu_type == MESH_PDU_TYPE_SEGMENT_ACKNOWLEDGMENT)){
1231         btstack_memory_mesh_network_pdu_free(adv_bearer_network_pdu);
1232     }
1233     adv_bearer_network_pdu = NULL;
1234 #endif
1235 #ifdef ENABLE_MESH_GATT_BEARER
1236     if ((gatt_bearer_network_pdu != NULL) && (gatt_bearer_network_pdu->pdu_header.pdu_type == MESH_PDU_TYPE_SEGMENT_ACKNOWLEDGMENT)){
1237         btstack_memory_mesh_network_pdu_free(gatt_bearer_network_pdu);
1238     }
1239     gatt_bearer_network_pdu = NULL;
1240 #endif
1241     if ((outgoing_pdu != NULL) && (outgoing_pdu->pdu_header.pdu_type == MESH_PDU_TYPE_SEGMENT_ACKNOWLEDGMENT)){
1242         btstack_memory_mesh_network_pdu_free(outgoing_pdu);
1243     }
1244     outgoing_pdu = NULL;
1245 
1246     if (incoming_pdu_raw){
1247         mesh_network_pdu_free(incoming_pdu_raw);
1248         incoming_pdu_raw = NULL;
1249     }
1250     if (incoming_pdu_decoded){
1251         mesh_network_pdu_free(incoming_pdu_decoded);
1252         incoming_pdu_decoded = NULL;
1253     }
1254     mesh_crypto_active = 0;
1255 }
1256 
1257 // buffer pool
1258 mesh_network_pdu_t * mesh_network_pdu_get(void){
1259     mesh_network_pdu_t * network_pdu = btstack_memory_mesh_network_pdu_get();
1260     if (network_pdu) {
1261         memset(network_pdu, 0, sizeof(mesh_network_pdu_t));
1262         network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_NETWORK;
1263     }
1264     return network_pdu;
1265 }
1266 
1267 void mesh_network_pdu_free(mesh_network_pdu_t * network_pdu){
1268     btstack_memory_mesh_network_pdu_free(network_pdu);
1269     if (mesh_network_free_pdu_callback!=NULL){
1270         void (*callback)(void) = mesh_network_free_pdu_callback;
1271         mesh_network_free_pdu_callback= NULL;
1272         (*callback)();
1273     }
1274 }
1275 
1276 void mesh_network_notify_on_freed_pdu(void (*callback)(void)){
1277     btstack_assert(mesh_network_free_pdu_callback == NULL);
1278     mesh_network_free_pdu_callback = callback;
1279 }
1280 
1281 
1282 // Mesh Subnet Management
1283 
1284 void mesh_subnet_add(mesh_subnet_t * subnet){
1285     btstack_linked_list_add_tail(&subnets, (btstack_linked_item_t *) subnet);
1286 }
1287 
1288 void mesh_subnet_remove(mesh_subnet_t * subnet){
1289     btstack_linked_list_remove(&subnets, (btstack_linked_item_t *) subnet);
1290 }
1291 
1292 mesh_subnet_t * mesh_subnet_get_by_netkey_index(uint16_t netkey_index){
1293     btstack_linked_list_iterator_t it;
1294     btstack_linked_list_iterator_init(&it, &subnets);
1295     while (btstack_linked_list_iterator_has_next(&it)){
1296         mesh_subnet_t * item = (mesh_subnet_t *) btstack_linked_list_iterator_next(&it);
1297         if (item->netkey_index == netkey_index) return item;
1298     }
1299     return NULL;
1300 }
1301 
1302 int mesh_subnet_list_count(void){
1303     return btstack_linked_list_count(&subnets);
1304 }
1305 
1306 // mesh network key iterator over all keys
1307 void mesh_subnet_iterator_init(mesh_subnet_iterator_t *it){
1308     btstack_linked_list_iterator_init(&it->it, &subnets);
1309 }
1310 
1311 int mesh_subnet_iterator_has_more(mesh_subnet_iterator_t *it){
1312     return btstack_linked_list_iterator_has_next(&it->it);
1313 }
1314 
1315 mesh_subnet_t * mesh_subnet_iterator_get_next(mesh_subnet_iterator_t *it){
1316     return (mesh_subnet_t *) btstack_linked_list_iterator_next(&it->it);
1317 }
1318 
1319 mesh_network_key_t * mesh_subnet_get_outgoing_network_key(mesh_subnet_t * subnet){
1320     switch (subnet->key_refresh){
1321         case MESH_KEY_REFRESH_SECOND_PHASE:
1322             return subnet->new_key;
1323         case MESH_KEY_REFRESH_NOT_ACTIVE:
1324         case MESH_KEY_REFRESH_FIRST_PHASE:
1325         default:
1326             return subnet->old_key;
1327     }
1328 }
1329 
1330 /**
1331  * @brief Setup subnet for given netkey index
1332  */
1333 void mesh_subnet_setup_for_netkey_index(uint16_t netkey_index){
1334     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
1335     if (subnet != NULL) return;
1336 
1337     // find old / new keys
1338     mesh_network_key_t * old_key = NULL;
1339     mesh_network_key_t * new_key = NULL;
1340     mesh_network_key_iterator_t it;
1341     mesh_network_key_iterator_init(&it);
1342     while (mesh_network_key_iterator_has_more(&it)){
1343         mesh_network_key_t * network_key = mesh_network_key_iterator_get_next(&it);
1344         if (network_key->netkey_index != netkey_index) continue;
1345         if (old_key == NULL){
1346             old_key = network_key;
1347             continue;
1348         }
1349         // assign current key depending on key version
1350         if (((int8_t) (network_key->version - new_key->version)) > 0) {
1351             new_key = network_key;
1352         } else {
1353             new_key = old_key;
1354             old_key = network_key;
1355         }
1356     }
1357 
1358     // create subnet for netkey index
1359     subnet = btstack_memory_mesh_subnet_get();
1360     if (subnet == NULL) return;
1361     subnet->netkey_index = netkey_index;
1362     mesh_subnet_add(subnet);
1363 
1364     // set keys
1365     subnet->old_key = old_key;
1366     subnet->new_key = new_key;
1367 
1368     // key refresh
1369     if (new_key == NULL){
1370         // single key -> key refresh not active
1371         subnet->key_refresh = MESH_KEY_REFRESH_NOT_ACTIVE;
1372     }
1373     else {
1374         // two keys -> at least phase 1
1375         subnet->key_refresh = MESH_KEY_REFRESH_FIRST_PHASE;
1376     }
1377 }
1378