xref: /btstack/src/mesh/mesh_network.c (revision 6f6f8b16b187b6f853cd67c766447d952356c78d)
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 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_network.c"
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "btstack_debug.h"
45 #include "btstack_event.h"
46 #include "btstack_memory.h"
47 #include "btstack_util.h"
48 
49 #include "mesh/beacon.h"
50 #include "mesh/mesh_foundation.h"
51 #include "mesh/mesh_iv_index_seq_number.h"
52 #include "mesh/mesh_keys.h"
53 #include "mesh/mesh_node.h"
54 #include "mesh/provisioning.h"
55 #include "mesh/provisioning_device.h"
56 
57 #ifdef ENABLE_MESH_ADV_BEARER
58 #include "mesh/adv_bearer.h"
59 #endif
60 
61 #ifdef ENABLE_MESH_GATT_BEARER
62 #include "mesh/gatt_bearer.h"
63 #endif
64 
65 // configuration
66 #define MESH_NETWORK_CACHE_SIZE 2
67 
68 // debug config
69 #define LOG_NETWORK
70 
71 static void mesh_network_dump_network_pdus(const char * name, btstack_linked_list_t * list);
72 
73 // structs
74 
75 // globals
76 
77 static void (*mesh_network_higher_layer_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu);
78 static void (*mesh_network_proxy_message_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu);
79 
80 #ifdef ENABLE_MESH_GATT_BEARER
81 static hci_con_handle_t gatt_bearer_con_handle;
82 #endif
83 
84 // shared send/receive crypto
85 static int mesh_crypto_active;
86 
87 // crypto requests
88 static union {
89     btstack_crypto_ccm_t         ccm;
90     btstack_crypto_aes128_t      aes128;
91 } mesh_network_crypto_request;
92 
93 static const mesh_network_key_t *  current_network_key;
94 
95 // PECB calculation
96 static uint8_t encryption_block[16];
97 static uint8_t obfuscation_block[16];
98 
99 // Subnets
100 static btstack_linked_list_t subnets;
101 
102 // Network Nonce
103 static uint8_t network_nonce[13];
104 
105 // INCOMING //
106 
107 // unprocessed network pdu - added by mesh_network_pdus_received_message
108 static btstack_linked_list_t        network_pdus_received;
109 
110 // in validation
111 static mesh_network_pdu_t *         incoming_pdu_raw;
112 static mesh_network_pdu_t *         incoming_pdu_decoded;
113 static mesh_network_key_iterator_t  validation_network_key_it;
114 
115 // OUTGOING //
116 
117 // Network PDUs queued by mesh_network_send
118 static btstack_linked_list_t network_pdus_queued;
119 
120 // Network PDU about to get send via all bearers when encrypted
121 static mesh_network_pdu_t * outgoing_pdu;
122 
123 // Network PDUs ready to send via GATT Bearer
124 static btstack_linked_list_t network_pdus_outgoing_gatt;
125 
126 #ifdef ENABLE_MESH_GATT_BEARER
127 static mesh_network_pdu_t * gatt_bearer_network_pdu;
128 #endif
129 
130 // Network PDUs ready to send via ADV Bearer
131 static btstack_linked_list_t network_pdus_outgoing_adv;
132 
133 #ifdef ENABLE_MESH_ADV_BEARER
134 static mesh_network_pdu_t * adv_bearer_network_pdu;
135 #endif
136 
137 
138 // mesh network cache - we use 32-bit 'hashes'
139 static uint32_t mesh_network_cache[MESH_NETWORK_CACHE_SIZE];
140 static int      mesh_network_cache_index;
141 
142 // register for freed network pdu
143 void (*mesh_network_free_pdu_callback)(void);
144 
145 // prototypes
146 
147 static void mesh_network_run(void);
148 static void process_network_pdu_validate(void);
149 
150 // network caching
151 static uint32_t mesh_network_cache_hash(mesh_network_pdu_t * network_pdu){
152     // - The SEQ field is a 24-bit integer that when combined with the IV Index,
153     // shall be a unique value for each new Network PDU originated by this node (=> SRC)
154     // - IV updates only rarely
155     // => 16 bit SRC, 1 bit IVI, 15 bit SEQ
156     uint8_t  ivi = network_pdu->data[0] >> 7;
157     uint16_t seq = big_endian_read_16(network_pdu->data, 3);
158     uint16_t src = big_endian_read_16(network_pdu->data, 5);
159     return (src << 16) | (ivi << 15) | (seq & 0x7fff);
160 }
161 
162 static int mesh_network_cache_find(uint32_t hash){
163     int i;
164     for (i = 0; i < MESH_NETWORK_CACHE_SIZE; i++) {
165         if (mesh_network_cache[i] == hash) {
166             return 1;
167         }
168     }
169     return 0;
170 }
171 
172 static void mesh_network_cache_add(uint32_t hash){
173     mesh_network_cache[mesh_network_cache_index++] = hash;
174     if (mesh_network_cache_index >= MESH_NETWORK_CACHE_SIZE){
175         mesh_network_cache_index = 0;
176     }
177 }
178 
179 // common helper
180 int mesh_network_address_unicast(uint16_t addr){
181     return addr != MESH_ADDRESS_UNSASSIGNED && (addr < 0x8000);
182 }
183 
184 int mesh_network_address_virtual(uint16_t addr){
185     return (addr & 0xC000) == 0x8000;   // 0b10xx xxxx xxxx xxxx
186 }
187 
188 int mesh_network_address_group(uint16_t addr){
189     return (addr & 0xC000) == 0xC000;   // 0b11xx xxxx xxxx xxxx
190 }
191 
192 int mesh_network_address_all_proxies(uint16_t addr){
193     return addr == MESH_ADDRESS_ALL_PROXIES;
194 }
195 
196 int mesh_network_address_all_nodes(uint16_t addr){
197     return addr == MESH_ADDRESS_ALL_NODES;
198 }
199 
200 int mesh_network_address_all_friends(uint16_t addr){
201     return addr == MESH_ADDRESS_ALL_FRIENDS;
202 }
203 
204 int mesh_network_address_all_relays(uint16_t addr){
205     return addr == MESH_ADDRESS_ALL_RELAYS;
206 }
207 
208 int mesh_network_addresses_valid(uint8_t ctl, uint16_t src, uint16_t dst){
209     // printf("CTL: %u\n", ctl);
210     // printf("SRC: %04x\n", src);
211     // printf("DST: %04x\n", dst);
212     if (src == 0){
213         // printf("SRC Unassigned Addr -> ignore\n");
214         return 0;
215     }
216     if ((src & 0xC000) == 0x8000){
217         // printf("SRC Virtual Addr -> ignore\n");
218         return 0;
219     }
220     if ((src & 0xC000) == 0xC000){
221         // printf("SRC Group Addr -> ignore\n");
222         return 0;
223     }
224     if (dst == 0){
225         // printf("DST Unassigned Addr -> ignore\n");
226         return 0;
227     }
228     if ( ((dst & 0xC000) == 0x8000) && (ctl == 1)){
229         // printf("DST Virtual Addr in CONTROL -> ignore\n");
230         return 0;
231     }
232     if ( (0xFF00 <= dst) && (dst <= 0xfffb) && (ctl == 0) ){
233         // printf("DST RFU Group Addr in MESSAGE -> ignore\n");
234         return 0;
235     }
236     // printf("SRC + DST Addr valid\n");
237     return 1;
238 }
239 
240 static void mesh_network_create_nonce(uint8_t * nonce, const mesh_network_pdu_t * pdu, uint32_t iv_index){
241     unsigned int pos = 0;
242     nonce[pos++] = 0x0;      // Network Nonce
243     (void)memcpy(&nonce[pos], &pdu->data[1], 6);
244     pos += 6;
245     big_endian_store_16(nonce, pos, 0);
246     pos += 2;
247     big_endian_store_32(nonce, pos, iv_index);
248 }
249 
250 static void mesh_proxy_create_nonce(uint8_t * nonce, const mesh_network_pdu_t * pdu, uint32_t iv_index){
251     unsigned int pos = 0;
252     nonce[pos++] = 0x3;      // Proxy Nonce
253     nonce[pos++] = 0;
254     (void)memcpy(&nonce[pos], &pdu->data[2], 5);
255     pos += 5;
256     big_endian_store_16(nonce, pos, 0);
257     pos += 2;
258     big_endian_store_32(nonce, pos, iv_index);
259 }
260 
261 // NID/IVI | obfuscated (CTL/TTL, SEQ (24), SRC (16) ), encrypted ( DST(16), TransportPDU), MIC(32 or 64)
262 
263 static void mesh_network_send_complete(mesh_network_pdu_t * network_pdu){
264     if (network_pdu->flags & MESH_NETWORK_PDU_FLAGS_RELAY){
265 #ifdef LOG_NETWORK
266         printf("TX-F-NetworkPDU (%p): relay -> free packet\n", network_pdu);
267 #endif
268         mesh_network_pdu_free(network_pdu);
269     } else {
270 #ifdef LOG_NETWORK
271         printf("TX-F-NetworkPDU (%p): notify lower transport\n", network_pdu);
272 #endif
273         // notify higher layer
274         (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_SENT, network_pdu);
275     }
276 }
277 
278 // new
279 static void mesh_network_send_c(void *arg){
280     UNUSED(arg);
281 
282     // obfuscate
283     unsigned int i;
284     for (i=0;i<6;i++){
285         outgoing_pdu->data[1+i] ^= obfuscation_block[i];
286     }
287 
288 #ifdef LOG_NETWORK
289     printf("TX-C-NetworkPDU (%p): ", outgoing_pdu);
290     printf_hexdump(outgoing_pdu->data, outgoing_pdu->len);
291 #endif
292 
293     // crypto done
294     mesh_crypto_active = 0;
295 
296     // done
297     mesh_network_pdu_t * network_pdu = outgoing_pdu;
298     outgoing_pdu = NULL;
299 
300     if ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION) != 0){
301         // encryption requested by mesh_network_encrypt_proxy_configuration_message
302         (*mesh_network_proxy_message_handler)(MESH_NETWORK_PDU_ENCRYPTED, network_pdu);
303         return;
304     }
305 
306 #ifdef LOG_NETWORK
307     printf("TX-D-NetworkPDU (%p): ", network_pdu);
308     printf_hexdump(network_pdu->data, network_pdu->len);
309 #endif
310 
311     // add to queue
312     btstack_linked_list_add_tail(&network_pdus_outgoing_gatt, (btstack_linked_item_t *) network_pdu);
313 
314     // go
315     mesh_network_run();
316 }
317 
318 static void mesh_network_send_b(void *arg){
319     UNUSED(arg);
320 
321     uint32_t iv_index = mesh_get_iv_index_for_tx();
322 
323     // store NetMIC
324     uint8_t net_mic[8];
325     btstack_crypto_ccm_get_authentication_value(&mesh_network_crypto_request.ccm, net_mic);
326 
327     // store MIC
328     uint8_t net_mic_len = outgoing_pdu->data[1] & 0x80 ? 8 : 4;
329     (void)memcpy(&outgoing_pdu->data[outgoing_pdu->len], net_mic, net_mic_len);
330     outgoing_pdu->len += net_mic_len;
331 
332     btstack_assert(outgoing_pdu->len <= 29);
333 
334 #ifdef LOG_NETWORK
335     printf("TX-B-NetworkPDU (%p): ", outgoing_pdu);
336     printf_hexdump(outgoing_pdu->data, outgoing_pdu->len);
337 #endif
338 
339     // calc PECB
340     memset(encryption_block, 0, 5);
341     big_endian_store_32(encryption_block, 5, iv_index);
342     (void)memcpy(&encryption_block[9], &outgoing_pdu->data[7], 7);
343     btstack_crypto_aes128_encrypt(&mesh_network_crypto_request.aes128, current_network_key->privacy_key, encryption_block, obfuscation_block, &mesh_network_send_c, NULL);
344 }
345 
346 static void mesh_network_send_a(void){
347 
348     mesh_crypto_active = 1;
349 
350     uint32_t iv_index = mesh_get_iv_index_for_tx();
351 
352     // lookup subnet by netkey_index
353     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(outgoing_pdu->netkey_index);
354     if (!subnet) {
355         mesh_crypto_active = 0;
356         mesh_network_pdu_t * network_pdu = outgoing_pdu;
357         outgoing_pdu = NULL;
358         // notify upper layer
359         mesh_network_send_complete(network_pdu);
360         // run again
361         mesh_network_run();
362         return;
363     }
364 
365     // get network key to use for sending
366     current_network_key = mesh_subnet_get_outgoing_network_key(subnet);
367 
368 #ifdef LOG_NETWORK
369     printf("TX-A-NetworkPDU (%p): ", outgoing_pdu);
370     printf_hexdump(outgoing_pdu->data, outgoing_pdu->len);
371 #endif
372 
373     // get network nonce
374     if (outgoing_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
375         mesh_proxy_create_nonce(network_nonce, outgoing_pdu, iv_index);
376 #ifdef LOG_NETWORK
377         printf("TX-ProxyNonce:  ");
378         printf_hexdump(network_nonce, 13);
379 #endif
380     } else {
381         mesh_network_create_nonce(network_nonce, outgoing_pdu, iv_index);
382 #ifdef LOG_NETWORK
383         printf("TX-NetworkNonce:  ");
384         printf_hexdump(network_nonce, 13);
385 #endif
386     }
387 
388 #ifdef LOG_NETWORK
389    printf("TX-EncryptionKey: ");
390     printf_hexdump(current_network_key->encryption_key, 16);
391 #endif
392 
393     // start ccm
394     uint8_t cypher_len  = outgoing_pdu->len - 7;
395     uint8_t net_mic_len = outgoing_pdu->data[1] & 0x80 ? 8 : 4;
396     btstack_crypto_ccm_init(&mesh_network_crypto_request.ccm, current_network_key->encryption_key, network_nonce, cypher_len, 0, net_mic_len);
397     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);
398 }
399 
400 #if defined(ENABLE_MESH_RELAY) || defined (ENABLE_MESH_PROXY_SERVER)
401 static void mesh_network_relay_message(mesh_network_pdu_t * network_pdu){
402 
403     uint8_t ctl_ttl      = network_pdu->data[1];
404     uint8_t ctl_in_bit_7 = ctl_ttl & 0x80;
405     uint8_t ttl          = ctl_ttl & 0x7f;
406 
407     // prepare pdu for resending
408     network_pdu->data[1] = ctl_in_bit_7 | (ttl - 1);
409     network_pdu->flags |= MESH_NETWORK_PDU_FLAGS_RELAY;
410 
411 #ifdef LOG_NETWORK
412     printf("TX-Relay-NetworkPDU (%p): ", network_pdu);
413     printf_hexdump(network_pdu->data, network_pdu->len);
414     printf("^^ into network_pdus_queued\n");
415 #endif
416 
417     uint8_t net_mic_len = ctl_in_bit_7 ? 8 : 4;
418     btstack_assert((network_pdu->len + net_mic_len) <= 29);
419 
420     // queue up
421     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
422 }
423 #endif
424 
425 void mesh_network_message_processed_by_higher_layer(mesh_network_pdu_t * network_pdu){
426 
427 #if defined(ENABLE_MESH_RELAY) || defined (ENABLE_MESH_PROXY_SERVER)
428 
429     // check if address does not matches elements on our node and TTL >= 2
430     uint16_t src     = mesh_network_src(network_pdu);
431     uint8_t  ttl     = mesh_network_ttl(network_pdu);
432 
433     uint16_t mesh_network_primary_address = mesh_node_get_primary_element_address();
434 
435     if (((src < mesh_network_primary_address) || (src > (mesh_network_primary_address + mesh_node_element_count()))) && (ttl >= 2)){
436 
437         if ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0){
438 
439             // message received via ADV bearer are relayed:
440 
441 #ifdef ENABLE_MESH_RELAY
442             if (mesh_foundation_relay_get() != 0){
443                 // - to ADV bearer, if Relay supported and enabledx
444                 mesh_network_relay_message(network_pdu);
445                 mesh_network_run();
446                 return;
447             }
448 #endif
449 
450 #ifdef ENABLE_MESH_PROXY_SERVER
451             if (mesh_foundation_gatt_proxy_get() != 0){
452                 // - to GATT bearer, if Proxy supported and enabled
453                 mesh_network_relay_message(network_pdu);
454                 mesh_network_run();
455                 return;
456             }
457 #endif
458 
459         } else {
460 
461             // messages received via GATT bearer are relayed:
462 
463 #ifdef ENABLE_MESH_PROXY_SERVER
464             if (mesh_foundation_gatt_proxy_get() != 0){
465                 // - to ADV bearer, if Proxy supported and enabled
466                 mesh_network_relay_message(network_pdu);
467                 mesh_network_run();
468                 return;
469             }
470 #endif
471 
472         }
473     }
474 #endif
475 
476     // otherwise, we're done
477     btstack_memory_mesh_network_pdu_free(network_pdu);
478 }
479 
480 static void process_network_pdu_done(void){
481     btstack_memory_mesh_network_pdu_free(incoming_pdu_raw);
482     incoming_pdu_raw = NULL;
483     mesh_crypto_active = 0;
484 
485     mesh_network_run();
486 }
487 
488 static void process_network_pdu_validate_d(void * arg){
489     UNUSED(arg);
490     // mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
491 
492     uint8_t ctl_ttl     = incoming_pdu_decoded->data[1];
493     uint8_t ctl         = ctl_ttl >> 7;
494     uint8_t net_mic_len = (ctl_ttl & 0x80) ? 8 : 4;
495 
496     // store NetMIC
497     uint8_t net_mic[8];
498     btstack_crypto_ccm_get_authentication_value(&mesh_network_crypto_request.ccm, net_mic);
499 #ifdef LOG_NETWORK
500     printf("RX-NetMIC (%p): ", incoming_pdu_decoded);
501     printf_hexdump(net_mic, net_mic_len);
502 #endif
503     // store in decoded pdu
504     (void)memcpy(&incoming_pdu_decoded->data[incoming_pdu_decoded->len - net_mic_len],
505                  net_mic, net_mic_len);
506 
507 #ifdef LOG_NETWORK
508     uint8_t cypher_len  = incoming_pdu_decoded->len - 9 - net_mic_len;
509     printf("RX-Decrypted DST/TransportPDU (%p): ", incoming_pdu_decoded);
510     printf_hexdump(&incoming_pdu_decoded->data[7], 2 + cypher_len);
511 
512     printf("RX-Decrypted: ");
513     printf_hexdump(incoming_pdu_decoded->data, incoming_pdu_decoded->len);
514 #endif
515 
516     // validate network mic
517     if (memcmp(net_mic, &incoming_pdu_raw->data[incoming_pdu_decoded->len-net_mic_len], net_mic_len) != 0){
518         // fail
519         printf("RX-NetMIC mismatch, try next key (%p)\n", incoming_pdu_decoded);
520         process_network_pdu_validate();
521         return;
522     }
523 
524     // remove NetMIC from payload
525     incoming_pdu_decoded->len -= net_mic_len;
526 
527 #ifdef LOG_NETWORK
528     // match
529     printf("RX-NetMIC matches (%p)\n", incoming_pdu_decoded);
530     printf("RX-TTL (%p): 0x%02x\n", incoming_pdu_decoded, incoming_pdu_decoded->data[1] & 0x7f);
531 #endif
532 
533     // set netkey_index
534     incoming_pdu_decoded->netkey_index = current_network_key->netkey_index;
535 
536     if (incoming_pdu_decoded->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
537 
538         mesh_network_pdu_t * decoded_pdu = incoming_pdu_decoded;
539         incoming_pdu_decoded = NULL;
540 
541         // no additional checks for proxy messages
542         (*mesh_network_proxy_message_handler)(MESH_NETWORK_PDU_RECEIVED, decoded_pdu);
543 
544     } else {
545 
546         // validate src/dest addresses
547         uint16_t src = big_endian_read_16(incoming_pdu_decoded->data, 5);
548         uint16_t dst = big_endian_read_16(incoming_pdu_decoded->data, 7);
549         int valid = mesh_network_addresses_valid(ctl, src, dst);
550         if (!valid){
551 #ifdef LOG_NETWORK
552             printf("RX Address invalid (%p)\n", incoming_pdu_decoded);
553 #endif
554             btstack_memory_mesh_network_pdu_free(incoming_pdu_decoded);
555             incoming_pdu_decoded = NULL;
556             process_network_pdu_done();
557             return;
558         }
559 
560         // check cache
561         uint32_t hash = mesh_network_cache_hash(incoming_pdu_decoded);
562 #ifdef LOG_NETWORK
563         printf("RX-Hash (%p): %08x\n", incoming_pdu_decoded, hash);
564 #endif
565         if (mesh_network_cache_find(hash)){
566             // found in cache, drop
567 #ifdef LOG_NETWORK
568             printf("Found in cache -> drop packet (%p)\n", incoming_pdu_decoded);
569 #endif
570             btstack_memory_mesh_network_pdu_free(incoming_pdu_decoded);
571             incoming_pdu_decoded = NULL;
572             process_network_pdu_done();
573             return;
574         }
575 
576         // store in network cache
577         mesh_network_cache_add(hash);
578 
579 #ifdef LOG_NETWORK
580             printf("RX-Validated (%p) - forward to lower transport\n", incoming_pdu_decoded);
581 #endif
582 
583         // forward to lower transport layer. message is freed by call to mesh_network_message_processed_by_upper_layer
584         mesh_network_pdu_t * decoded_pdu = incoming_pdu_decoded;
585         incoming_pdu_decoded = NULL;
586         (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_RECEIVED, decoded_pdu);
587     }
588 
589     // done
590     process_network_pdu_done();
591 }
592 
593 static uint32_t iv_index_for_pdu(const mesh_network_pdu_t * network_pdu){
594     // get IV Index and IVI
595     uint32_t iv_index = mesh_get_iv_index();
596     int ivi = network_pdu->data[0] >> 7;
597 
598     // if least significant bit differs, use previous IV Index
599     if ((iv_index & 1 ) ^ ivi){
600         iv_index--;
601 #ifdef LOG_NETWORK
602         printf("RX-IV: IVI indicates previous IV index, using 0x%08x\n", iv_index);
603 #endif
604     }
605     return iv_index;
606 }
607 
608 static void process_network_pdu_validate_b(void * arg){
609     UNUSED(arg);
610 
611 #ifdef LOG_NETWORK
612     printf("RX-PECB: ");
613     printf_hexdump(obfuscation_block, 6);
614 #endif
615 
616     // de-obfuscate
617     unsigned int i;
618     for (i=0;i<6;i++){
619         incoming_pdu_decoded->data[1+i] = incoming_pdu_raw->data[1+i] ^ obfuscation_block[i];
620     }
621 
622     uint32_t iv_index = iv_index_for_pdu(incoming_pdu_raw);
623 
624     if (incoming_pdu_decoded->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
625         // create network nonce
626         mesh_proxy_create_nonce(network_nonce, incoming_pdu_decoded, iv_index);
627 #ifdef LOG_NETWORK
628         printf("RX-Proxy Nonce: ");
629         printf_hexdump(network_nonce, 13);
630 #endif
631     } else {
632         // create network nonce
633         mesh_network_create_nonce(network_nonce, incoming_pdu_decoded, iv_index);
634 #ifdef LOG_NETWORK
635         printf("RX-Network Nonce: ");
636         printf_hexdump(network_nonce, 13);
637 #endif
638     }
639 
640     //
641     uint8_t ctl_ttl     = incoming_pdu_decoded->data[1];
642     uint8_t net_mic_len = (ctl_ttl & 0x80) ? 8 : 4;
643     uint8_t cypher_len  = incoming_pdu_decoded->len - 7 - net_mic_len;
644 
645 #ifdef LOG_NETWORK
646     printf("RX-Cyper len %u, mic len %u\n", cypher_len, net_mic_len);
647 
648     printf("RX-Encryption Key: ");
649     printf_hexdump(current_network_key->encryption_key, 16);
650 
651 #endif
652 
653     btstack_crypto_ccm_init(&mesh_network_crypto_request.ccm, current_network_key->encryption_key, network_nonce, cypher_len, 0, net_mic_len);
654     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);
655 }
656 
657 static void process_network_pdu_validate(void){
658     if (!mesh_network_key_nid_iterator_has_more(&validation_network_key_it)){
659         printf("No valid network key found\n");
660         btstack_memory_mesh_network_pdu_free(incoming_pdu_decoded);
661         incoming_pdu_decoded = NULL;
662         process_network_pdu_done();
663         return;
664     }
665 
666     current_network_key = mesh_network_key_nid_iterator_get_next(&validation_network_key_it);
667 
668     // calc PECB
669     uint32_t iv_index = iv_index_for_pdu(incoming_pdu_raw);
670     memset(encryption_block, 0, 5);
671     big_endian_store_32(encryption_block, 5, iv_index);
672     (void)memcpy(&encryption_block[9], &incoming_pdu_raw->data[7], 7);
673     btstack_crypto_aes128_encrypt(&mesh_network_crypto_request.aes128, current_network_key->privacy_key, encryption_block, obfuscation_block, &process_network_pdu_validate_b, NULL);
674 }
675 
676 
677 static void process_network_pdu(void){
678     //
679     uint8_t nid_ivi = incoming_pdu_raw->data[0];
680 
681     // setup pdu object
682     incoming_pdu_decoded->data[0] = nid_ivi;
683     incoming_pdu_decoded->len     = incoming_pdu_raw->len;
684     incoming_pdu_decoded->flags   = incoming_pdu_raw->flags;
685 
686     // init provisioning data iterator
687     uint8_t nid = nid_ivi & 0x7f;
688     // uint8_t iv_index = network_pdu_data[0] >> 7;
689     mesh_network_key_nid_iterator_init(&validation_network_key_it, nid);
690 
691     process_network_pdu_validate();
692 }
693 
694 // returns true if done
695 static bool mesh_network_run_gatt(void){
696     if (btstack_linked_list_empty(&network_pdus_outgoing_gatt)){
697         return true;
698     }
699 
700 #ifdef ENABLE_MESH_GATT_BEARER
701     if (gatt_bearer_network_pdu != NULL){
702         return true;
703     }
704 
705     // move to 'gatt bearer queue'
706     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_gatt);
707 
708 #ifdef LOG_NETWORK
709     printf("network run 1: pop %p from network_pdus_outgoing_gatt\n", network_pdu);
710 #endif
711     // request to send via gatt if:
712     // proxy active and connected
713     // packet wasn't received via gatt bearer
714     int send_via_gatt = ((mesh_foundation_gatt_proxy_get() != 0) &&
715                         (gatt_bearer_con_handle != HCI_CON_HANDLE_INVALID) &&
716                         ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0));
717     if (send_via_gatt){
718 
719 #ifdef LOG_NETWORK
720         printf("network run 2: set %p as gatt_bearer_network_pdu\n", network_pdu);
721 #endif
722         gatt_bearer_network_pdu = network_pdu;
723         gatt_bearer_request_can_send_now_for_network_pdu();
724 
725     } else {
726 
727 #ifdef LOG_NETWORK
728         printf("network run 3: push %p to network_pdus_outgoing_adv\n", network_pdu);
729 #endif
730         btstack_linked_list_add_tail(&network_pdus_outgoing_adv, (btstack_linked_item_t *) network_pdu);
731 
732 #ifdef LOG_NETWORK
733         mesh_network_dump_network_pdus("network_pdus_outgoing_adv (1)", &network_pdus_outgoing_adv);
734 #endif
735     }
736 #else
737     // directly move to 'outgoing adv bearer queue'
738     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_gatt);
739     btstack_linked_list_add_tail(&network_pdus_outgoing_adv, (btstack_linked_item_t *) network_pdu);
740 #endif
741     return false;
742 }
743 
744 // returns true if done
745 static bool mesh_network_run_adv(void){
746 
747     if (btstack_linked_list_empty(&network_pdus_outgoing_adv)){
748         return true;
749     }
750 
751 #ifdef ENABLE_MESH_ADV_BEARER
752     if (adv_bearer_network_pdu != NULL){
753         return true;
754     }
755 
756     // move to 'adv bearer queue'
757     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_adv);
758 
759 #ifdef LOG_NETWORK
760     printf("network run 4: pop %p from network_pdus_outgoing_adv\n", network_pdu);
761     mesh_network_dump_network_pdus("network_pdus_outgoing_adv (3)", &network_pdus_outgoing_adv);
762     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());
763 #endif
764 
765     // send via adv if:
766     // packet was received via gatt bearer and proxy active, or,
767     // packet originated locally (== not relayed), or,
768     // packet was received via ADV bearer and relay is active, or,
769     int send_via_adv = (((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) != 0) && (mesh_foundation_gatt_proxy_get() == 1)) ||
770                        (((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0) && (mesh_foundation_relay_get() == 1)) ||
771                         ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_RELAY) == 0);
772 
773     if (send_via_adv){
774 #ifdef LOG_NETWORK
775         printf("network run 6: set %p as to adv_bearer_network_pdu\n", network_pdu);
776 #endif
777         adv_bearer_network_pdu = network_pdu;
778         adv_bearer_request_can_send_now_for_network_pdu();
779     } else {
780 #ifdef LOG_NETWORK
781         printf("network run 7: skip sending %p via adv bearer\n", network_pdu);
782         #endif
783         // directly notify upper layer
784         mesh_network_send_complete(network_pdu);
785     }
786 #else
787     // done
788     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing_adv);
789     // directly notify upper layer
790     mesh_network_send_complete(network_pdu);
791 #endif
792     return false;
793 }
794 
795 // returns true if done
796 static bool mesh_network_run_received(void){
797     if (mesh_crypto_active) {
798         return true;
799     }
800 
801     if (btstack_linked_list_empty(&network_pdus_received)) {
802         return true;
803     }
804 
805     incoming_pdu_decoded = mesh_network_pdu_get();
806     if (incoming_pdu_decoded == NULL) return true;
807 
808     // get encoded network pdu and start processing
809     mesh_crypto_active = 1;
810     incoming_pdu_raw = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_received);
811     process_network_pdu();
812     return true;
813 }
814 
815 // returns true if done
816 static bool mesh_network_run_queued(void){
817     if (mesh_crypto_active) {
818         return true;
819     }
820 
821     if (btstack_linked_list_empty(&network_pdus_queued)){
822         return true;
823     }
824 
825     // get queued network pdu and start processing
826     outgoing_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_queued);
827 
828 #ifdef LOG_NETWORK
829     printf("network run 5: pop %p from network_pdus_queued\n", outgoing_pdu);
830     mesh_network_dump_network_pdus("network_pdus_queued (2)", &network_pdus_queued);
831 #endif
832     mesh_network_send_a();
833     return true;
834 }
835 
836 static void mesh_network_run(void){
837     while (true){
838         bool done = true;
839         done &= mesh_network_run_gatt();
840         done &= mesh_network_run_adv();
841         done &= mesh_network_run_received();
842         done &= mesh_network_run_queued();
843         if (done) break;
844     }
845 }
846 
847 #ifdef ENABLE_MESH_ADV_BEARER
848 static void mesh_adv_bearer_handle_network_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
849     UNUSED(channel);
850     mesh_network_pdu_t * network_pdu;
851     uint8_t  transmission_count;
852     uint16_t transmission_interval;
853     uint8_t  transmit_config;
854 
855     switch (packet_type){
856         case MESH_NETWORK_PACKET:
857             // check len. minimal transport PDU len = 1, 32 bit NetMIC -> 13 bytes
858             if (size < 13) break;
859 
860 #ifdef LOG_NETWORK
861             printf("received network pdu from adv (len %u): ", size);
862             printf_hexdump(packet, size);
863 #endif
864             mesh_network_received_message(packet, size, 0);
865             break;
866 
867         case HCI_EVENT_PACKET:
868             switch(packet[0]){
869                 case HCI_EVENT_MESH_META:
870                     switch(packet[2]){
871                         case MESH_SUBEVENT_CAN_SEND_NOW:
872                             if (adv_bearer_network_pdu == NULL) break;
873 
874                             // Get Transmission config depending on relay flag
875                             if (adv_bearer_network_pdu->flags & MESH_NETWORK_PDU_FLAGS_RELAY){
876                                 transmit_config = mesh_foundation_relay_get();
877                             } else {
878                                 transmit_config = mesh_foundation_network_transmit_get();
879                             }
880                             transmission_count     = (transmit_config & 0x07) + 1;
881                             transmission_interval = (transmit_config >> 3) * 10;
882 
883 #ifdef LOG_NETWORK
884                             printf("TX-E-NetworkPDU (%p) count %u, interval %u ms: ", adv_bearer_network_pdu, transmission_count, transmission_interval);
885                             printf_hexdump(adv_bearer_network_pdu->data, adv_bearer_network_pdu->len);
886 #endif
887 
888                             adv_bearer_send_network_pdu(adv_bearer_network_pdu->data, adv_bearer_network_pdu->len, transmission_count, transmission_interval);
889                             network_pdu = adv_bearer_network_pdu;
890                             adv_bearer_network_pdu = NULL;
891 
892                             // notify upper layer
893                             mesh_network_send_complete(network_pdu);
894 
895                             // check if more to send
896                             mesh_network_run();
897                             break;
898                         default:
899                             break;
900                     }
901                     break;
902                 default:
903                     break;
904             }
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 #ifdef ENABLE_MESH_ADV_BEARER
1229     adv_bearer_network_pdu = NULL;
1230 #endif
1231 #ifdef ENABLE_MESH_GATT_BEARER
1232     gatt_bearer_network_pdu = NULL;
1233 #endif
1234     outgoing_pdu = NULL;
1235 
1236     if (incoming_pdu_raw){
1237         mesh_network_pdu_free(incoming_pdu_raw);
1238         incoming_pdu_raw = NULL;
1239     }
1240     if (incoming_pdu_decoded){
1241         mesh_network_pdu_free(incoming_pdu_decoded);
1242         incoming_pdu_decoded = NULL;
1243     }
1244     mesh_crypto_active = 0;
1245 }
1246 
1247 // buffer pool
1248 mesh_network_pdu_t * mesh_network_pdu_get(void){
1249     mesh_network_pdu_t * network_pdu = btstack_memory_mesh_network_pdu_get();
1250     if (network_pdu) {
1251         memset(network_pdu, 0, sizeof(mesh_network_pdu_t));
1252         network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_NETWORK;
1253     }
1254     return network_pdu;
1255 }
1256 
1257 void mesh_network_pdu_free(mesh_network_pdu_t * network_pdu){
1258     btstack_memory_mesh_network_pdu_free(network_pdu);
1259     if (mesh_network_free_pdu_callback!=NULL){
1260         void (*callback)(void) = mesh_network_free_pdu_callback;
1261         mesh_network_free_pdu_callback= NULL;
1262         (*callback)();
1263     }
1264 }
1265 
1266 void mesh_network_notify_on_freed_pdu(void (*callback)(void)){
1267     btstack_assert(mesh_network_free_pdu_callback == NULL);
1268     mesh_network_free_pdu_callback = callback;
1269 }
1270 
1271 
1272 // Mesh Subnet Management
1273 
1274 void mesh_subnet_add(mesh_subnet_t * subnet){
1275     btstack_linked_list_add_tail(&subnets, (btstack_linked_item_t *) subnet);
1276 }
1277 
1278 void mesh_subnet_remove(mesh_subnet_t * subnet){
1279     btstack_linked_list_remove(&subnets, (btstack_linked_item_t *) subnet);
1280 }
1281 
1282 mesh_subnet_t * mesh_subnet_get_by_netkey_index(uint16_t netkey_index){
1283     btstack_linked_list_iterator_t it;
1284     btstack_linked_list_iterator_init(&it, &subnets);
1285     while (btstack_linked_list_iterator_has_next(&it)){
1286         mesh_subnet_t * item = (mesh_subnet_t *) btstack_linked_list_iterator_next(&it);
1287         if (item->netkey_index == netkey_index) return item;
1288     }
1289     return NULL;
1290 }
1291 
1292 int mesh_subnet_list_count(void){
1293     return btstack_linked_list_count(&subnets);
1294 }
1295 
1296 // mesh network key iterator over all keys
1297 void mesh_subnet_iterator_init(mesh_subnet_iterator_t *it){
1298     btstack_linked_list_iterator_init(&it->it, &subnets);
1299 }
1300 
1301 int mesh_subnet_iterator_has_more(mesh_subnet_iterator_t *it){
1302     return btstack_linked_list_iterator_has_next(&it->it);
1303 }
1304 
1305 mesh_subnet_t * mesh_subnet_iterator_get_next(mesh_subnet_iterator_t *it){
1306     return (mesh_subnet_t *) btstack_linked_list_iterator_next(&it->it);
1307 }
1308 
1309 mesh_network_key_t * mesh_subnet_get_outgoing_network_key(mesh_subnet_t * subnet){
1310     switch (subnet->key_refresh){
1311         case MESH_KEY_REFRESH_SECOND_PHASE:
1312             return subnet->new_key;
1313         case MESH_KEY_REFRESH_NOT_ACTIVE:
1314         case MESH_KEY_REFRESH_FIRST_PHASE:
1315         default:
1316             return subnet->old_key;
1317     }
1318 }
1319 
1320 /**
1321  * @brief Setup subnet for given netkey index
1322  */
1323 void mesh_subnet_setup_for_netkey_index(uint16_t netkey_index){
1324     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
1325     if (subnet != NULL) return;
1326 
1327     // find old / new keys
1328     mesh_network_key_t * old_key = NULL;
1329     mesh_network_key_t * new_key = NULL;
1330     mesh_network_key_iterator_t it;
1331     mesh_network_key_iterator_init(&it);
1332     while (mesh_network_key_iterator_has_more(&it)){
1333         mesh_network_key_t * network_key = mesh_network_key_iterator_get_next(&it);
1334         if (network_key->netkey_index != netkey_index) continue;
1335         if (old_key == NULL){
1336             old_key = network_key;
1337             continue;
1338         }
1339         // assign current key depending on key version
1340         if (((int8_t) (network_key->version - new_key->version)) > 0) {
1341             new_key = network_key;
1342         } else {
1343             new_key = old_key;
1344             old_key = network_key;
1345         }
1346     }
1347 
1348     // create subnet for netkey index
1349     subnet = btstack_memory_mesh_subnet_get();
1350     if (subnet == NULL) return;
1351     subnet->netkey_index = netkey_index;
1352     mesh_subnet_add(subnet);
1353 
1354     // set keys
1355     subnet->old_key = old_key;
1356     subnet->new_key = new_key;
1357 
1358     // key refresh
1359     if (new_key == NULL){
1360         // single key -> key refresh not active
1361         subnet->key_refresh = MESH_KEY_REFRESH_NOT_ACTIVE;
1362     }
1363     else {
1364         // two keys -> at least phase 1
1365         subnet->key_refresh = MESH_KEY_REFRESH_FIRST_PHASE;
1366     }
1367 }
1368