xref: /btstack/src/mesh/mesh_network.c (revision 6f14746dcaf54c99ef5984e7a1ee17fd815acef5)
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 <stdint.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include "mesh/beacon.h"
45 #include "provisioning.h"
46 #include "provisioning_device.h"
47 #include "mesh_keys.h"
48 #include "mesh_foundation.h"
49 #include "btstack_util.h"
50 #include "btstack_debug.h"
51 #include "btstack_event.h"
52 #include "btstack_memory.h"
53 #include "mesh_iv_index_seq_number.h"
54 
55 #ifdef ENABLE_MESH_ADV_BEARER
56 #include "mesh/adv_bearer.h"
57 #endif
58 
59 #ifdef ENABLE_MESH_GATT_BEARER
60 #include "mesh/gatt_bearer.h"
61 #endif
62 
63 // configuration
64 #define MESH_NETWORK_CACHE_SIZE 2
65 // #define ENABLE_MESH_RELAY
66 
67 // debug config
68 // #define LOG_NETWORK
69 
70 // structs
71 
72 // globals
73 
74 static uint16_t mesh_network_primary_address;
75 static uint16_t mesh_network_num_elements;
76 static void (*mesh_network_higher_layer_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu);
77 static void (*mesh_network_proxy_message_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu);
78 
79 #ifdef ENABLE_MESH_GATT_BEARER
80 static hci_con_handle_t gatt_bearer_con_handle;
81 #endif
82 
83 // shared send/receive crypto
84 static int mesh_crypto_active;
85 
86 // crypto requests
87 static union {
88     btstack_crypto_ccm_t         ccm;
89     btstack_crypto_aes128_t      aes128;
90 } mesh_network_crypto_request;
91 
92 static const mesh_network_key_t *  current_network_key;
93 
94 // PECB calculation
95 static uint8_t encryption_block[16];
96 static uint8_t obfuscation_block[16];
97 
98 // Subnets
99 static btstack_linked_list_t subnets;
100 
101 // Network Nonce
102 static uint8_t network_nonce[13];
103 
104 // INCOMING //
105 
106 // unprocessed network pdu - added by mesh_network_pdus_received_message
107 static btstack_linked_list_t        network_pdus_received;
108 
109 // in validation
110 static mesh_network_pdu_t *         network_pdu_in_validation;
111 static mesh_network_key_iterator_t  validation_network_key_it;
112 
113 // OUTGOING //
114 
115 // Network PDUs queued by mesh_network_send
116 static btstack_linked_list_t network_pdus_queued;
117 
118 // Network PDUs ready to send
119 static btstack_linked_list_t network_pdus_outgoing;
120 
121 #ifdef ENABLE_MESH_ADV_BEARER
122 static mesh_network_pdu_t * adv_bearer_network_pdu;
123 #endif
124 
125 #ifdef ENABLE_MESH_GATT_BEARER
126 static mesh_network_pdu_t * gatt_bearer_network_pdu;
127 #endif
128 
129 // mesh network cache - we use 32-bit 'hashes'
130 static uint32_t mesh_network_cache[MESH_NETWORK_CACHE_SIZE];
131 static int      mesh_network_cache_index;
132 
133 // prototypes
134 
135 static void mesh_network_run(void);
136 static void process_network_pdu_validate(mesh_network_pdu_t * network_pdu);
137 
138 // network caching
139 static uint32_t mesh_network_cache_hash(mesh_network_pdu_t * network_pdu){
140     // - The SEQ field is a 24-bit integer that when combined with the IV Index,
141     // shall be a unique value for each new Network PDU originated by this node (=> SRC)
142     // - IV updates only rarely
143     // => 16 bit SRC, 1 bit IVI, 15 bit SEQ
144     uint8_t  ivi = network_pdu->data[0] >> 7;
145     uint16_t seq = big_endian_read_16(network_pdu->data, 3);
146     uint16_t src = big_endian_read_16(network_pdu->data, 5);
147     return (src << 16) | (ivi << 15) | (seq & 0x7fff);
148 }
149 
150 static int mesh_network_cache_find(uint32_t hash){
151     int i;
152     for (i = 0; i < MESH_NETWORK_CACHE_SIZE; i++) {
153         if (mesh_network_cache[i] == hash) {
154             return 1;
155         }
156     }
157     return 0;
158 }
159 
160 static void mesh_network_cache_add(uint32_t hash){
161     mesh_network_cache[mesh_network_cache_index++] = hash;
162     if (mesh_network_cache_index >= MESH_NETWORK_CACHE_SIZE){
163         mesh_network_cache_index = 0;
164     }
165 }
166 
167 // common helper
168 int mesh_network_address_unicast(uint16_t addr){
169     return addr != MESH_ADDRESS_UNSASSIGNED && (addr < 0x8000);
170 }
171 
172 int mesh_network_address_virtual(uint16_t addr){
173     return (addr & 0xC000) == 0x8000;   // 0b10xx xxxx xxxx xxxx
174 }
175 
176 int mesh_network_address_group(uint16_t addr){
177     return (addr & 0xC000) == 0xC000;   // 0b11xx xxxx xxxx xxxx
178 }
179 
180 int mesh_network_address_all_proxies(uint16_t addr){
181     return addr == MESH_ADDRESS_ALL_PROXIES;
182 }
183 
184 int mesh_network_address_all_nodes(uint16_t addr){
185     return addr == MESH_ADDRESS_ALL_NODES;
186 }
187 
188 int mesh_network_address_all_friends(uint16_t addr){
189     return addr == MESH_ADDRESS_ALL_FRIENDS;
190 }
191 
192 int mesh_network_address_all_relays(uint16_t addr){
193     return addr == MESH_ADDRESS_ALL_RELAYS;
194 }
195 
196 int mesh_network_addresses_valid(uint8_t ctl, uint16_t src, uint16_t dst){
197     // printf("CTL: %u\n", ctl);
198     // printf("SRC: %04x\n", src);
199     // printf("DST: %04x\n", dst);
200     if (src == 0){
201         // printf("SRC Unassigned Addr -> ignore\n");
202         return 0;
203     }
204     if ((src & 0xC000) == 0x8000){
205         // printf("SRC Virtual Addr -> ignore\n");
206         return 0;
207     }
208     if ((src & 0xC000) == 0xC000){
209         // printf("SRC Group Addr -> ignore\n");
210         return 0;
211     }
212     if (dst == 0){
213         // printf("DST Unassigned Addr -> ignore\n");
214         return 0;
215     }
216     if ( ((dst & 0xC000) == 0x8000) && (ctl == 1)){
217         // printf("DST Virtual Addr in CONTROL -> ignore\n");
218         return 0;
219     }
220     if ( (0xFF00 <= dst) && (dst <= 0xfffb) && (ctl == 0) ){
221         // printf("DST RFU Group Addr in MESSAGE -> ignore\n");
222         return 0;
223     }
224     // printf("SRC + DST Addr valid\n");
225     return 1;
226 }
227 
228 static void mesh_network_create_nonce(uint8_t * nonce, const mesh_network_pdu_t * pdu, uint32_t iv_index){
229     unsigned int pos = 0;
230     nonce[pos++] = 0x0;      // Network Nonce
231     memcpy(&nonce[pos], &pdu->data[1], 6);
232     pos += 6;
233     big_endian_store_16(nonce, pos, 0);
234     pos += 2;
235     big_endian_store_32(nonce, pos, iv_index);
236 }
237 
238 static void mesh_proxy_create_nonce(uint8_t * nonce, const mesh_network_pdu_t * pdu, uint32_t iv_index){
239     unsigned int pos = 0;
240     nonce[pos++] = 0x3;      // Proxy Nonce
241     nonce[pos++] = 0;
242     memcpy(&nonce[pos], &pdu->data[2], 5);
243     pos += 5;
244     big_endian_store_16(nonce, pos, 0);
245     pos += 2;
246     big_endian_store_32(nonce, pos, iv_index);
247 }
248 
249 // NID/IVI | obfuscated (CTL/TTL, SEQ (24), SRC (16) ), encrypted ( DST(16), TransportPDU), MIC(32 or 64)
250 
251 static void mesh_network_send_d(mesh_network_pdu_t * network_pdu){
252 
253 #ifdef LOG_NETWORK
254     printf("TX-D-NetworkPDU (%p): ", network_pdu);
255     printf_hexdump(network_pdu->data, network_pdu->len);
256 #endif
257 
258     // add to queue
259     btstack_linked_list_add_tail(&network_pdus_outgoing, (btstack_linked_item_t *) network_pdu);
260 
261     // go
262     mesh_network_run();
263 }
264 
265 // new
266 static void mesh_network_send_c(void *arg){
267     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
268 
269     // obfuscate
270     unsigned int i;
271     for (i=0;i<6;i++){
272         network_pdu->data[1+i] ^= obfuscation_block[i];
273     }
274 
275 #ifdef LOG_NETWORK
276     printf("TX-C-NetworkPDU (%p): ", network_pdu);
277     printf_hexdump(network_pdu->data, network_pdu->len);
278 #endif
279 
280     // crypto done
281     mesh_crypto_active = 0;
282 
283     // done
284     (network_pdu->callback)(network_pdu);
285 }
286 
287 static void mesh_network_send_b(void *arg){
288     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
289 
290     uint32_t iv_index = mesh_get_iv_index_for_tx();
291 
292     // store NetMIC
293     uint8_t net_mic[8];
294     btstack_crypto_ccm_get_authentication_value(&mesh_network_crypto_request.ccm, net_mic);
295 
296     // store MIC
297     uint8_t net_mic_len = network_pdu->data[1] & 0x80 ? 8 : 4;
298     memcpy(&network_pdu->data[network_pdu->len], net_mic, net_mic_len);
299     network_pdu->len += net_mic_len;
300 
301 #ifdef LOG_NETWORK
302     printf("TX-B-NetworkPDU (%p): ", network_pdu);
303     printf_hexdump(network_pdu->data, network_pdu->len);
304 #endif
305 
306     // calc PECB
307     memset(encryption_block, 0, 5);
308     big_endian_store_32(encryption_block, 5, iv_index);
309     memcpy(&encryption_block[9], &network_pdu->data[7], 7);
310     btstack_crypto_aes128_encrypt(&mesh_network_crypto_request.aes128, current_network_key->privacy_key, encryption_block, obfuscation_block, &mesh_network_send_c, network_pdu);
311 }
312 
313 static void mesh_network_send_a(mesh_network_pdu_t * network_pdu){
314 
315     mesh_crypto_active = 1;
316 
317     uint32_t iv_index = mesh_get_iv_index_for_tx();
318 
319     // lookup subnet by netkey_index
320     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(network_pdu->netkey_index);
321     if (!subnet) {
322         mesh_crypto_active = 0;
323         // notify upper layer
324         (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_SENT, network_pdu);
325         // run again
326         mesh_network_run();
327         return;
328     }
329 
330     // get network key to use for sending
331     current_network_key = mesh_subnet_get_outgoing_network_key(subnet);
332 
333     // get network nonce
334     if (network_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
335         mesh_proxy_create_nonce(network_nonce, network_pdu, iv_index);
336 #ifdef LOG_NETWORK
337         printf("TX-ProxyNonce:  ");
338         printf_hexdump(network_nonce, 13);
339 #endif
340     } else {
341         mesh_network_create_nonce(network_nonce, network_pdu, iv_index);
342 #ifdef LOG_NETWORK
343         printf("TX-NetworkNonce:  ");
344         printf_hexdump(network_nonce, 13);
345 #endif
346     }
347 
348 #ifdef LOG_NETWORK
349    printf("TX-EncryptionKey: ");
350     printf_hexdump(current_network_key->encryption_key, 16);
351 #endif
352 
353     // start ccm
354     uint8_t cypher_len  = network_pdu->len - 7;
355     uint8_t net_mic_len = network_pdu->data[1] & 0x80 ? 8 : 4;
356     btstack_crypto_ccm_init(&mesh_network_crypto_request.ccm, current_network_key->encryption_key, network_nonce, cypher_len, 0, net_mic_len);
357     btstack_crypto_ccm_encrypt_block(&mesh_network_crypto_request.ccm, cypher_len, &network_pdu->data[7], &network_pdu->data[7], &mesh_network_send_b, network_pdu);
358 }
359 
360 #if defined(ENABLE_MESH_RELAY) || defined (ENABLE_MESH_PROXY_SERVER)
361 static void mesh_network_relay_message(mesh_network_pdu_t * network_pdu){
362     uint8_t ctl_ttl     = network_pdu->data[1];
363     uint8_t ctl         = ctl_ttl & 0x80;
364     uint8_t ttl         = ctl_ttl & 0x7f;
365     uint8_t net_mic_len = ctl ? 8 : 4;
366 
367     // prepare pdu for resending
368     network_pdu->len    -= net_mic_len;
369     network_pdu->data[1] = (ctl << 7) | (ttl - 1);
370     network_pdu->flags |= MESH_NETWORK_PDU_FLAGS_RELAY;
371 
372     // queue up
373     network_pdu->callback = &mesh_network_send_d;
374     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
375 }
376 #endif
377 
378 void mesh_network_message_processed_by_higher_layer(mesh_network_pdu_t * network_pdu){
379 
380 #if defined(ENABLE_MESH_RELAY) || defined (ENABLE_MESH_PROXY_SERVER)
381 
382     // check if address does not matches elements on our node and TTL >= 2
383     uint16_t src     = mesh_network_src(network_pdu);
384     uint8_t  ttl     = mesh_network_ttl(network_pdu);
385     if (((src < mesh_network_primary_address) || (src > (mesh_network_primary_address + mesh_network_num_elements))) && (ttl >= 2)){
386 
387         if ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0){
388 
389             // message received via ADV bearer are relayed:
390 
391 #ifdef ENABLE_MESH_RELAY
392             if (mesh_foundation_relay_get() != 0){
393                 // - to ADV bearer, if Relay supported and enabled
394                 mesh_network_relay_message(network_pdu);
395                 mesh_network_run();
396                 return;
397             }
398 #endif
399 
400 #ifdef ENABLE_MESH_PROXY_SERVER
401             if (mesh_foundation_gatt_proxy_get() != 0){
402                 // - to GATT bearer, if Proxy supported and enabled
403                 mesh_network_relay_message(network_pdu);
404                 mesh_network_run();
405                 return;
406             }
407 #endif
408 
409         } else {
410 
411             // messages received via GATT bearer are relayed:
412 
413 #ifdef ENABLE_MESH_PROXY_SERVER
414             if (mesh_foundation_gatt_proxy_get() != 0){
415                 // - to ADV bearer, if Proxy supported and enabled
416                 mesh_network_relay_message(network_pdu);
417                 mesh_network_run();
418                 return;
419             }
420 #endif
421 
422         }
423     }
424 #endif
425 
426     // otherwise, we're done
427     btstack_memory_mesh_network_pdu_free(network_pdu);
428 }
429 
430 static void process_network_pdu_done(void){
431     btstack_memory_mesh_network_pdu_free(network_pdu_in_validation);
432     network_pdu_in_validation = NULL;
433     mesh_crypto_active = 0;
434 
435     mesh_network_run();
436 }
437 
438 static void process_network_pdu_validate_d(void * arg){
439     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
440 
441     uint8_t ctl_ttl     = network_pdu->data[1];
442     uint8_t ctl         = ctl_ttl >> 7;
443     uint8_t net_mic_len = (ctl_ttl & 0x80) ? 8 : 4;
444 
445     // store NetMIC
446     uint8_t net_mic[8];
447     btstack_crypto_ccm_get_authentication_value(&mesh_network_crypto_request.ccm, net_mic);
448 #ifdef LOG_NETWORK
449     printf("RX-NetMIC: ");
450     printf_hexdump(net_mic, net_mic_len);
451 #endif
452     // store in pdu
453     memcpy(&network_pdu->data[network_pdu->len-net_mic_len], net_mic, net_mic_len);
454 
455 #ifdef LOG_NETWORK
456     uint8_t cypher_len  = network_pdu->len - 9 - net_mic_len;
457     printf("RX-Decrypted DST/TransportPDU: ");
458     printf_hexdump(&network_pdu->data[7], 2 + cypher_len);
459 
460     printf("RX-Decrypted: ");
461     printf_hexdump(network_pdu->data, network_pdu->len);
462 #endif
463 
464     // validate network mic
465     if (memcmp(net_mic, &network_pdu_in_validation->data[network_pdu->len-net_mic_len], net_mic_len) != 0){
466         // fail
467         printf("RX-NetMIC mismatch, try next key\n");
468         process_network_pdu_validate(network_pdu);
469         return;
470     }
471 
472     // remove NetMIC from payload
473     network_pdu->len -= net_mic_len;
474 
475 #ifdef LOG_NETWORK
476     // match
477     printf("RX-NetMIC matches\n");
478     printf("RX-TTL: 0x%02x\n", network_pdu->data[1] & 0x7f);
479 #endif
480 
481     // set netkey_index
482     network_pdu->netkey_index = current_network_key->netkey_index;
483 
484     if (network_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
485 
486         // no additional checks for proxy messages
487         (*mesh_network_proxy_message_handler)(MESH_NETWORK_PDU_RECEIVED, network_pdu);
488 
489     } else {
490 
491         // validate src/dest addresses
492         uint16_t src = big_endian_read_16(network_pdu->data, 5);
493         uint16_t dst = big_endian_read_16(network_pdu->data, 7);
494         int valid = mesh_network_addresses_valid(ctl, src, dst);
495         if (!valid){
496             printf("RX Address invalid\n");
497             btstack_memory_mesh_network_pdu_free(network_pdu);
498             process_network_pdu_done();
499             return;
500         }
501 
502         // check cache
503         uint32_t hash = mesh_network_cache_hash(network_pdu);
504 #ifdef LOG_NETWORK
505         printf("RX-Hash: %08x\n", hash);
506 #endif
507         if (mesh_network_cache_find(hash)){
508             // found in cache, drop
509             printf("Found in cache -> drop packet\n");
510             btstack_memory_mesh_network_pdu_free(network_pdu);
511             process_network_pdu_done();
512             return;
513         }
514 
515         // store in network cache
516         mesh_network_cache_add(hash);
517 
518         // forward to lower transport layer. message is freed by call to mesh_network_message_processed_by_upper_layer
519         (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_RECEIVED, network_pdu);
520     }
521 
522     // done
523     process_network_pdu_done();
524 }
525 
526 static uint32_t iv_index_for_pdu(const mesh_network_pdu_t * network_pdu){
527     // get IV Index and IVI
528     uint32_t iv_index = mesh_get_iv_index();
529     int ivi = network_pdu->data[0] >> 7;
530 
531     // if least significant bit differs, use previous IV Index
532     if ((iv_index & 1 ) ^ ivi){
533         iv_index--;
534 #ifdef LOG_NETWORK
535         printf("RX-IV: IVI indicates previous IV index, using 0x%08x\n", iv_index);
536 #endif
537     }
538     return iv_index;
539 }
540 
541 static void process_network_pdu_validate_b(void * arg){
542     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
543 
544 #ifdef LOG_NETWORK
545     printf("RX-PECB: ");
546     printf_hexdump(obfuscation_block, 6);
547 #endif
548 
549     // de-obfuscate
550     unsigned int i;
551     for (i=0;i<6;i++){
552         network_pdu->data[1+i] = network_pdu_in_validation->data[1+i] ^ obfuscation_block[i];
553     }
554 
555     uint32_t iv_index = iv_index_for_pdu(network_pdu);
556 
557     if (network_pdu->flags & MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION){
558         // create network nonce
559         mesh_proxy_create_nonce(network_nonce, network_pdu, iv_index);
560 #ifdef LOG_NETWORK
561         printf("RX-Proxy Nonce: ");
562         printf_hexdump(network_nonce, 13);
563 #endif
564     } else {
565         // create network nonce
566         mesh_network_create_nonce(network_nonce, network_pdu, iv_index);
567 #ifdef LOG_NETWORK
568         printf("RX-Network Nonce: ");
569         printf_hexdump(network_nonce, 13);
570 #endif
571     }
572 
573     //
574     uint8_t ctl_ttl     = network_pdu->data[1];
575     uint8_t net_mic_len = (ctl_ttl & 0x80) ? 8 : 4;
576     uint8_t cypher_len  = network_pdu->len - 7 - net_mic_len;
577 
578 #ifdef LOG_NETWORK
579     printf("RX-Cyper len %u, mic len %u\n", cypher_len, net_mic_len);
580 
581     printf("RX-Encryption Key: ");
582     printf_hexdump(current_network_key->encryption_key, 16);
583 
584 #endif
585 
586     btstack_crypto_ccm_init(&mesh_network_crypto_request.ccm, current_network_key->encryption_key, network_nonce, cypher_len, 0, net_mic_len);
587     btstack_crypto_ccm_decrypt_block(&mesh_network_crypto_request.ccm, cypher_len, &network_pdu_in_validation->data[7], &network_pdu->data[7], &process_network_pdu_validate_d, network_pdu);
588 }
589 
590 static void process_network_pdu_validate(mesh_network_pdu_t * network_pdu){
591     if (!mesh_network_key_nid_iterator_has_more(&validation_network_key_it)){
592         printf("No valid network key found\n");
593         btstack_memory_mesh_network_pdu_free(network_pdu);
594         process_network_pdu_done();
595         return;
596     }
597 
598     current_network_key = mesh_network_key_nid_iterator_get_next(&validation_network_key_it);
599 
600     // calc PECB
601     uint32_t iv_index = iv_index_for_pdu(network_pdu);
602     memset(encryption_block, 0, 5);
603     big_endian_store_32(encryption_block, 5, iv_index);
604     memcpy(&encryption_block[9], &network_pdu_in_validation->data[7], 7);
605     btstack_crypto_aes128_encrypt(&mesh_network_crypto_request.aes128, current_network_key->privacy_key, encryption_block, obfuscation_block, &process_network_pdu_validate_b, network_pdu);
606 }
607 
608 
609 static void process_network_pdu(mesh_network_pdu_t * network_pdu){
610     //
611     uint8_t nid_ivi = network_pdu_in_validation->data[0];
612 
613     // setup pdu object
614     network_pdu->data[0] = nid_ivi;
615     network_pdu->len     = network_pdu_in_validation->len;
616     network_pdu->flags   = network_pdu_in_validation->flags;
617 
618     // init provisioning data iterator
619     uint8_t nid = nid_ivi & 0x7f;
620     // uint8_t iv_index = network_pdu_data[0] >> 7;
621     mesh_network_key_nid_iterator_init(&validation_network_key_it, nid);
622 
623     process_network_pdu_validate(network_pdu);
624 }
625 
626 // static void mesh_network_encrypt_and_obfuscate(mesh_network_pdu_t * network_pdu, void (*callback)(mesh_network_pdu_t * network_pdu)){
627 //     network_pdu->callback = callback;
628 // }
629 
630 static void mesh_network_run(void){
631     if (!btstack_linked_list_empty(&network_pdus_outgoing)){
632         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_outgoing);
633 
634 #ifdef ENABLE_MESH_GATT_BEARER
635         // request to send via gatt if:
636         // proxy active and connected
637         // packet wasn't received via gatt bearer
638         printf("mesh_network_run: pdu %p, proxy %u, con handle %4x\n", network_pdu, mesh_foundation_gatt_proxy_get(), gatt_bearer_con_handle);
639         if (network_pdu != NULL &&
640             (mesh_foundation_gatt_proxy_get() != 0) &&
641             (gatt_bearer_con_handle != HCI_CON_HANDLE_INVALID) &&
642             ((network_pdu->flags & MESH_NETWORK_PDU_FLAGS_GATT_BEARER) == 0)
643         ){
644             gatt_bearer_network_pdu = network_pdu;
645             network_pdu = NULL;
646             gatt_bearer_request_can_send_now_for_network_pdu();
647         }
648 #endif
649 #ifdef ENABLE_MESH_ADV_BEARER
650          // request to send via adv
651         if (network_pdu != NULL){
652             adv_bearer_network_pdu = network_pdu;
653             network_pdu = NULL;
654             adv_bearer_request_can_send_now_for_network_pdu();
655         }
656 #endif
657         if (network_pdu !=  NULL){
658             // notify upper layer
659             (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_SENT, network_pdu);
660         }
661     }
662 
663     if (mesh_crypto_active) return;
664 
665     if (!btstack_linked_list_empty(&network_pdus_received)){
666         mesh_network_pdu_t * decode_pdu = mesh_network_pdu_get();
667         if (!decode_pdu) return;
668         // get encoded network pdu and start processing
669         mesh_crypto_active = 1;
670         network_pdu_in_validation = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_received);
671         process_network_pdu(decode_pdu);
672         return;
673     }
674 
675     if (!btstack_linked_list_empty(&network_pdus_queued)){
676         // get queued network pdu and start processing
677         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&network_pdus_queued);
678         mesh_network_send_a(network_pdu);
679         return;
680     }
681 }
682 
683 #ifdef ENABLE_MESH_ADV_BEARER
684 static void mesh_adv_bearer_handle_network_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
685     mesh_network_pdu_t * network_pdu;
686 
687     switch (packet_type){
688         case MESH_NETWORK_PACKET:
689             // check len. minimal transport PDU len = 1, 32 bit NetMIC -> 13 bytes
690             if (size < 13) break;
691 
692 #ifdef LOG_NETWORK
693             printf("received network pdu from adv (len %u): ", size);
694             printf_hexdump(packet, size);
695 #endif
696             mesh_network_received_message(packet, size, 0);
697             break;
698 
699         case HCI_EVENT_PACKET:
700             switch(packet[0]){
701                 case HCI_EVENT_MESH_META:
702                     switch(packet[2]){
703                         case MESH_SUBEVENT_CAN_SEND_NOW:
704                             if (adv_bearer_network_pdu == NULL) break;
705 #ifdef LOG_NETWORK
706                             printf("TX-E-NetworkPDU (%p): ", adv_bearer_network_pdu);
707                             printf_hexdump(adv_bearer_network_pdu->data, adv_bearer_network_pdu->len);
708 #endif
709                             adv_bearer_send_network_pdu(adv_bearer_network_pdu->data, adv_bearer_network_pdu->len);
710                             network_pdu = adv_bearer_network_pdu;
711                             adv_bearer_network_pdu = NULL;
712 
713                             // notify upper layer
714                             (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_SENT, network_pdu);
715 
716                             // check if more to send
717                             mesh_network_run();
718                             break;
719                         default:
720                             break;
721                     }
722                     break;
723                 default:
724                     break;
725             }
726             break;
727     }
728 }
729 #endif
730 
731 #ifdef ENABLE_MESH_GATT_BEARER
732 static void mesh_network_gatt_bearer_outgoing_complete(void){
733 
734     if (gatt_bearer_network_pdu == NULL) return;
735 
736 #ifdef ENABLE_MESH_ADV_BEARER
737     // forward to adv bearer
738     adv_bearer_network_pdu = gatt_bearer_network_pdu;
739     gatt_bearer_network_pdu = NULL;
740     adv_bearer_request_can_send_now_for_network_pdu();
741     return;
742 #endif
743 
744     // done, notify upper layer
745      mesh_network_pdu_t * network_pdu = gatt_bearer_network_pdu;
746     gatt_bearer_network_pdu = NULL;
747     (*mesh_network_higher_layer_handler)(MESH_NETWORK_PDU_SENT, network_pdu);
748 }
749 
750 static void mesh_network_gatt_bearer_handle_network_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
751     switch (packet_type){
752         case MESH_PROXY_DATA_PACKET:
753             if (mesh_foundation_gatt_proxy_get() == 0) break;
754 #ifdef LOG_NETWORK
755             printf("received network pdu from gatt (len %u): ", size);
756             printf_hexdump(packet, size);
757 #endif
758             mesh_network_received_message(packet, size, MESH_NETWORK_PDU_FLAGS_GATT_BEARER);
759             break;
760         case HCI_EVENT_PACKET:
761             switch (hci_event_packet_get_type(packet)){
762                 case HCI_EVENT_MESH_META:
763                     switch (hci_event_mesh_meta_get_subevent_code(packet)){
764                         case MESH_SUBEVENT_PROXY_CONNECTED:
765                             gatt_bearer_con_handle = mesh_subevent_proxy_connected_get_con_handle(packet);
766                             break;
767                         case MESH_SUBEVENT_PROXY_DISCONNECTED:
768                             gatt_bearer_con_handle = HCI_CON_HANDLE_INVALID;
769                             mesh_network_gatt_bearer_outgoing_complete();
770                             break;
771                         case MESH_SUBEVENT_CAN_SEND_NOW:
772                             if (gatt_bearer_network_pdu == NULL) break;
773 #ifdef LOG_NETWORK
774                             printf("G-TX-E-NetworkPDU (%p): ", gatt_bearer_network_pdu);
775                             printf_hexdump(gatt_bearer_network_pdu->data, gatt_bearer_network_pdu->len);
776 #endif
777                             gatt_bearer_send_network_pdu(gatt_bearer_network_pdu->data, gatt_bearer_network_pdu->len);
778                             break;
779 
780                         case MESH_SUBEVENT_MESSAGE_SENT:
781                             mesh_network_gatt_bearer_outgoing_complete();
782                             break;
783                         default:
784                             break;
785                     }
786                     break;
787                 default:
788                     break;
789             }
790             break;
791         default:
792             break;
793     }
794 }
795 #endif
796 
797 #ifdef ENABLE_MESH_GATT_BEARER
798 static void mesh_netework_gatt_bearer_handle_proxy_configuration(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
799     switch (packet_type){
800         case MESH_PROXY_DATA_PACKET:
801             mesh_network_process_proxy_configuration_message(packet, size);
802             break;
803         case HCI_EVENT_PACKET:
804             switch (hci_event_packet_get_type(packet)){
805                 case HCI_EVENT_MESH_META:
806                     switch (hci_event_mesh_meta_get_subevent_code(packet)){
807                         case MESH_SUBEVENT_CAN_SEND_NOW:
808                             // forward to higher layer
809                             (*mesh_network_proxy_message_handler)(MESH_NETWORK_CAN_SEND_NOW, NULL);
810                             break;
811                         default:
812                             break;
813                     }
814                     break;
815                 default:
816                     break;
817             }
818             break;
819         default:
820             break;
821     }
822 }
823 #endif
824 
825 void mesh_network_init(void){
826 #ifdef ENABLE_MESH_ADV_BEARER
827     adv_bearer_register_for_network_pdu(&mesh_adv_bearer_handle_network_event);
828 #endif
829 #ifdef ENABLE_MESH_GATT_BEARER
830     gatt_bearer_con_handle = HCI_CON_HANDLE_INVALID;
831     gatt_bearer_register_for_network_pdu(&mesh_network_gatt_bearer_handle_network_event);
832     gatt_bearer_register_for_mesh_proxy_configuration(&mesh_netework_gatt_bearer_handle_proxy_configuration);
833 #endif
834 }
835 
836 void mesh_network_set_higher_layer_handler(void (*packet_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu)){
837     mesh_network_higher_layer_handler = packet_handler;
838 }
839 
840 void mesh_network_set_proxy_message_handler(void (*packet_handler)(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu)){
841     mesh_network_proxy_message_handler = packet_handler;
842 }
843 
844 void mesh_network_set_primary_element_address(uint16_t addr){
845     mesh_network_primary_address = addr;
846     mesh_network_num_elements = 1;
847 }
848 
849 void mesh_network_received_message(const uint8_t * pdu_data, uint8_t pdu_len, uint8_t flags){
850     // verify len
851     if (pdu_len > 29) return;
852 
853     // allocate network_pdu
854     mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
855     if (!network_pdu) return;
856 
857     // store data
858     memcpy(network_pdu->data, pdu_data, pdu_len);
859     network_pdu->len = pdu_len;
860     network_pdu->flags = flags;
861 
862     // add to list and go
863     btstack_linked_list_add_tail(&network_pdus_received, (btstack_linked_item_t *) network_pdu);
864     mesh_network_run();
865 
866 }
867 
868 void mesh_network_process_proxy_configuration_message(const uint8_t * pdu_data, uint8_t pdu_len){
869     // verify len
870     if (pdu_len > 29) return;
871 
872     // allocate network_pdu
873     mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
874     if (!network_pdu) return;
875 
876     // store data
877     memcpy(network_pdu->data, pdu_data, pdu_len);
878     network_pdu->len = pdu_len;
879     network_pdu->flags = MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION; // Network PDU
880 
881     // add to list and go
882     btstack_linked_list_add_tail(&network_pdus_received, (btstack_linked_item_t *) network_pdu);
883     mesh_network_run();
884 }
885 
886 void mesh_network_send_pdu(mesh_network_pdu_t * network_pdu){
887 #ifdef LOG_NETWORK
888     printf("TX-A-NetworkPDU (%p): ", network_pdu);
889     printf_hexdump(network_pdu->data, network_pdu->len);
890 #endif
891 
892     if (network_pdu->len > 29){
893         printf("too long, %u\n", network_pdu->len);
894         return;
895     }
896 
897     // setup callback
898     network_pdu->callback = &mesh_network_send_d;
899     network_pdu->flags    = 0;
900 
901     // queue up
902     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
903 
904     // go
905     mesh_network_run();
906 }
907 
908 void mesh_network_encrypt_proxy_configuration_message(mesh_network_pdu_t * network_pdu, void (* callback)(mesh_network_pdu_t * callback)){
909     printf("ProxyPDU(unencrypted): ");
910     printf_hexdump(network_pdu->data, network_pdu->len);
911 
912     // setup callback
913     network_pdu->callback = callback;
914     network_pdu->flags    = MESH_NETWORK_PDU_FLAGS_PROXY_CONFIGURATION;
915 
916     // queue up
917     btstack_linked_list_add_tail(&network_pdus_queued, (btstack_linked_item_t *) network_pdu);
918 
919     // go
920     mesh_network_run();
921 }
922 
923 /*
924  * @brief Setup network pdu header
925  * @param netkey_index
926  * @param ctl
927  * @param ttl
928  * @param seq
929  * @param dest
930  */
931 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){
932     memset(network_pdu, 0, sizeof(mesh_network_pdu_t));
933     // set netkey_index
934     network_pdu->netkey_index = netkey_index;
935     // setup header
936     network_pdu->data[network_pdu->len++] = (mesh_get_iv_index_for_tx() << 7) |  nid;
937     uint8_t ctl_ttl = (ctl << 7) | (ttl & 0x7f);
938     network_pdu->data[network_pdu->len++] = ctl_ttl;
939     big_endian_store_24(network_pdu->data, 2, seq);
940     network_pdu->len += 3;
941     big_endian_store_16(network_pdu->data, network_pdu->len, src);
942     network_pdu->len += 2;
943     big_endian_store_16(network_pdu->data, network_pdu->len, dest);
944     network_pdu->len += 2;
945     memcpy(&network_pdu->data[network_pdu->len], transport_pdu_data, transport_pdu_len);
946     network_pdu->len += transport_pdu_len;
947 }
948 
949 /*
950  * @brief Setup network pdu header
951  * @param netkey_index
952  * @param ctl
953  * @param ttl
954  * @param seq
955  * @param dest
956  */
957 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){
958     // set netkey_index
959     network_pdu->netkey_index = netkey_index;
960     // setup header
961     network_pdu->data[0] = (mesh_get_iv_index_for_tx() << 7) |  nid;
962     uint8_t ctl_ttl = (ctl << 7) | (ttl & 0x7f);
963     network_pdu->data[1] = ctl_ttl;
964     big_endian_store_24(network_pdu->data, 2, seq);
965     big_endian_store_16(network_pdu->data, 5, src);
966     big_endian_store_16(network_pdu->data, 7, dest);
967 }
968 
969 // Network PDU Getter
970 uint8_t  mesh_network_nid(mesh_network_pdu_t * network_pdu){
971     return network_pdu->data[0] & 0x7f;
972 }
973 uint16_t mesh_network_control(mesh_network_pdu_t * network_pdu){
974     return network_pdu->data[1] & 0x80;
975 }
976 uint8_t mesh_network_ttl(mesh_network_pdu_t * network_pdu){
977     return network_pdu->data[1] & 0x7f;
978 }
979 uint32_t mesh_network_seq(mesh_network_pdu_t * network_pdu){
980     return big_endian_read_24(network_pdu->data, 2);
981 }
982 uint16_t mesh_network_src(mesh_network_pdu_t * network_pdu){
983     return big_endian_read_16(network_pdu->data, 5);
984 }
985 uint16_t mesh_network_dst(mesh_network_pdu_t * network_pdu){
986     return big_endian_read_16(network_pdu->data, 7);
987 }
988 int mesh_network_segmented(mesh_network_pdu_t * network_pdu){
989     return network_pdu->data[9] & 0x80;
990 }
991 uint8_t * mesh_network_pdu_data(mesh_network_pdu_t * network_pdu){
992     return &network_pdu->data[9];
993 }
994 uint8_t   mesh_network_pdu_len(mesh_network_pdu_t * network_pdu){
995     return network_pdu->len - 9;
996 }
997 
998 static void mesh_network_dump_network_pdu(mesh_network_pdu_t * network_pdu){
999     if (network_pdu){
1000         printf("- %p: ", network_pdu); printf_hexdump(network_pdu->data, network_pdu->len);
1001     }
1002 }
1003 static void mesh_network_dump_network_pdus(const char * name, btstack_linked_list_t * list){
1004     printf("List: %s:\n", name);
1005     btstack_linked_list_iterator_t it;
1006     btstack_linked_list_iterator_init(&it, list);
1007     while (btstack_linked_list_iterator_has_next(&it)){
1008         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t*) btstack_linked_list_iterator_next(&it);
1009         mesh_network_dump_network_pdu(network_pdu);
1010     }
1011 }
1012 static void mesh_network_reset_network_pdus(btstack_linked_list_t * list){
1013     while (!btstack_linked_list_empty(list)){
1014         mesh_network_pdu_t * pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(list);
1015         btstack_memory_mesh_network_pdu_free(pdu);
1016     }
1017 }
1018 void mesh_network_dump(void){
1019     mesh_network_dump_network_pdus("network_pdus_received", &network_pdus_received);
1020     mesh_network_dump_network_pdus("network_pdus_queued", &network_pdus_queued);
1021     mesh_network_dump_network_pdus("network_pdus_outgoing", &network_pdus_outgoing);
1022     printf("network_pdu_in_validation: \n");
1023     mesh_network_dump_network_pdu(network_pdu_in_validation);
1024 }
1025 void mesh_network_reset(void){
1026     mesh_network_reset_network_pdus(&network_pdus_received);
1027     mesh_network_reset_network_pdus(&network_pdus_queued);
1028     mesh_network_reset_network_pdus(&network_pdus_outgoing);
1029 }
1030 
1031 // buffer pool
1032 mesh_network_pdu_t * mesh_network_pdu_get(void){
1033     mesh_network_pdu_t * network_pdu = btstack_memory_mesh_network_pdu_get();
1034     if (network_pdu) {
1035         memset(network_pdu, 0, sizeof(mesh_network_pdu_t));
1036         network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_NETWORK;
1037     }
1038     return network_pdu;
1039 }
1040 
1041 void mesh_network_pdu_free(mesh_network_pdu_t * network_pdu){
1042     btstack_memory_mesh_network_pdu_free(network_pdu);
1043 }
1044 
1045 // Mesh Subnet Management
1046 
1047 void mesh_subnet_add(mesh_subnet_t * subnet){
1048     btstack_linked_list_add_tail(&subnets, (btstack_linked_item_t *) subnet);
1049 }
1050 
1051 void mesh_subnet_remove(mesh_subnet_t * subnet){
1052     btstack_linked_list_remove(&subnets, (btstack_linked_item_t *) subnet);
1053 }
1054 
1055 mesh_subnet_t * mesh_subnet_get_by_netkey_index(uint16_t netkey_index){
1056     btstack_linked_list_iterator_t it;
1057     btstack_linked_list_iterator_init(&it, &subnets);
1058     while (btstack_linked_list_iterator_has_next(&it)){
1059         mesh_subnet_t * item = (mesh_subnet_t *) btstack_linked_list_iterator_next(&it);
1060         if (item->netkey_index == netkey_index) return item;
1061     }
1062     return NULL;
1063 }
1064 
1065 int mesh_subnet_list_count(void){
1066     return btstack_linked_list_count(&subnets);
1067 }
1068 
1069 // mesh network key iterator over all keys
1070 void mesh_subnet_iterator_init(mesh_subnet_iterator_t *it){
1071     btstack_linked_list_iterator_init(&it->it, &subnets);
1072 }
1073 
1074 int mesh_subnet_iterator_has_more(mesh_subnet_iterator_t *it){
1075     return btstack_linked_list_iterator_has_next(&it->it);
1076 }
1077 
1078 mesh_subnet_t * mesh_subnet_iterator_get_next(mesh_subnet_iterator_t *it){
1079     return (mesh_subnet_t *) btstack_linked_list_iterator_next(&it->it);
1080 }
1081 
1082 mesh_network_key_t * mesh_subnet_get_outgoing_network_key(mesh_subnet_t * subnet){
1083     switch (subnet->key_refresh){
1084         case MESH_KEY_REFRESH_SECOND_PHASE:
1085             return subnet->new_key;
1086         case MESH_KEY_REFRESH_NOT_ACTIVE:
1087         case MESH_KEY_REFRESH_FIRST_PHASE:
1088         default:
1089             return subnet->old_key;
1090     }
1091 }
1092 
1093 /**
1094  * @brief Setup subnet for given netkey index
1095  */
1096 void mesh_subnet_setup_for_netkey_index(uint16_t netkey_index){
1097     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
1098     if (subnet != NULL) return;
1099 
1100     // find old / new keys
1101     mesh_network_key_t * old_key = NULL;
1102     mesh_network_key_t * new_key = NULL;
1103     mesh_network_key_iterator_t it;
1104     mesh_network_key_iterator_init(&it);
1105     while (mesh_network_key_iterator_has_more(&it)){
1106         mesh_network_key_t * network_key = mesh_network_key_iterator_get_next(&it);
1107         if (network_key->netkey_index != netkey_index) continue;
1108         if (old_key == NULL){
1109             old_key = network_key;
1110             continue;
1111         }
1112         // assign current key depending on key version
1113         if (((int8_t) (network_key->version - new_key->version)) > 0) {
1114             new_key = network_key;
1115         } else {
1116             new_key = old_key;
1117             old_key = network_key;
1118         }
1119     }
1120 
1121     // create subnet for netkey index
1122     subnet = btstack_memory_mesh_subnet_get();
1123     if (subnet == NULL) return;
1124     subnet->netkey_index = netkey_index;
1125     mesh_subnet_add(subnet);
1126 
1127     // set keys
1128     subnet->old_key = old_key;
1129     subnet->new_key = new_key;
1130 
1131     // key refresh
1132     if (new_key == NULL){
1133         // single key -> key refresh not active
1134         subnet->key_refresh = MESH_KEY_REFRESH_NOT_ACTIVE;
1135     }
1136     else {
1137         // two keys -> at least phase 1
1138         subnet->key_refresh = MESH_KEY_REFRESH_FIRST_PHASE;
1139     }
1140 }
1141