xref: /btstack/src/mesh/mesh_upper_transport.c (revision 6f3fd12d2666a6213f4b3282f2093a091e66963a)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 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_upper_transport.c"
39 
40 #include "mesh/mesh_upper_transport.h"
41 
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "btstack_util.h"
47 #include "btstack_memory.h"
48 
49 #include "mesh/beacon.h"
50 #include "mesh/mesh_iv_index_seq_number.h"
51 #include "mesh/mesh_keys.h"
52 #include "mesh/mesh_lower_transport.h"
53 #include "mesh/mesh_peer.h"
54 #include "mesh/mesh_virtual_addresses.h"
55 
56 static void (*higher_layer_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
57 
58 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
59     printf("%-20s ", name);
60     printf_hexdump(data, len);
61 }
62 // static void mesh_print_x(const char * name, uint32_t value){
63 //     printf("%20s: 0x%x", name, (int) value);
64 // }
65 
66 
67 // combined key x address iterator for upper transport decryption
68 
69 typedef struct {
70     // state
71     mesh_transport_key_iterator_t  key_it;
72     mesh_virtual_address_iterator_t address_it;
73     // elements
74     const mesh_transport_key_t *   key;
75     const mesh_virtual_address_t * address;
76     // address - might be virtual
77     uint16_t dst;
78     // key info
79 } mesh_transport_key_and_virtual_address_iterator_t;
80 
81 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
82                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
83                                                                  uint8_t aid) {
84     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
85     // config
86     it->dst   = dst;
87     // init elements
88     it->key     = NULL;
89     it->address = NULL;
90     // init element iterators
91     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
92     // init address iterator
93     if (mesh_network_address_virtual(it->dst)){
94         mesh_virtual_address_iterator_init(&it->address_it, dst);
95         // get first key
96         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
97             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
98         }
99     }
100 }
101 
102 // cartesian product: keys x addressses
103 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
104     if (mesh_network_address_virtual(it->dst)) {
105         // find next valid entry
106         while (1){
107             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
108             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
109             // get next key
110             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
111             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
112         }
113     } else {
114         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
115     }
116 }
117 
118 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
119     if (mesh_network_address_virtual(it->dst)) {
120         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
121     } else {
122         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
123     }
124 }
125 
126 // UPPER TRANSPORT
127 
128 // stub lower transport
129 
130 static void mesh_upper_transport_validate_unsegmented_message(void);
131 static void mesh_upper_transport_validate_segmented_message(void);
132 
133 static void mesh_transport_run(void);
134 
135 static int crypto_active;
136 static mesh_network_pdu_t   * incoming_network_pdu_raw;
137 static mesh_network_pdu_t   * incoming_network_pdu_decoded;
138 static mesh_transport_pdu_t * incoming_transport_pdu_raw;
139 static mesh_transport_pdu_t * incoming_transport_pdu_decoded;
140 static uint8_t application_nonce[13];
141 static btstack_crypto_ccm_t ccm;
142 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
143 
144 // upper transport callbacks - in access layer
145 static void (*mesh_access_message_handler)(mesh_pdu_t * pdu);
146 static void (*mesh_control_message_handler)(mesh_pdu_t * pdu);
147 
148 // unsegmented (network) and segmented (transport) control and access messages
149 static btstack_linked_list_t upper_transport_incoming;
150 
151 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
152     printf("List: %s:\n", name);
153     btstack_linked_list_iterator_t it;
154     btstack_linked_list_iterator_init(&it, list);
155     while (btstack_linked_list_iterator_has_next(&it)){
156         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
157         printf("- %p\n", pdu);
158         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
159     }
160 }
161 
162 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
163     while (!btstack_linked_list_empty(list)){
164         mesh_pdu_t * pdu = (mesh_pdu_t *) btstack_linked_list_pop(list);
165         switch (pdu->pdu_type){
166             case MESH_PDU_TYPE_NETWORK:
167                 btstack_memory_mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
168                 break;
169             case MESH_PDU_TYPE_TRANSPORT:
170                 btstack_memory_mesh_transport_pdu_free((mesh_transport_pdu_t *) pdu);
171                 break;
172             default:
173                 break;
174         }
175     }
176 }
177 
178 void mesh_upper_transport_dump(void){
179     printf("incoming_network_pdu_raw: %p\n", incoming_network_pdu_raw);
180     printf("incoming_network_pdu_decoded: %p\n", incoming_network_pdu_decoded);
181     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
182 }
183 
184 void mesh_upper_transport_reset(void){
185     crypto_active = 0;
186     if (incoming_network_pdu_raw){
187         mesh_network_pdu_free(incoming_network_pdu_raw);
188         incoming_network_pdu_raw = NULL;
189     }
190     // if (incoming_network_pdu_decoded){
191     //     mesh_network_pdu_free(incoming_network_pdu_decoded);
192     //     incoming_network_pdu_decoded = NULL;
193     // }
194     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
195 }
196 
197 static void mesh_upper_unsegmented_control_message_received(mesh_network_pdu_t * network_pdu){
198     uint8_t * lower_transport_pdu     = mesh_network_pdu_data(network_pdu);
199     uint8_t  opcode = lower_transport_pdu[0];
200     if (mesh_control_message_handler){
201         mesh_control_message_handler((mesh_pdu_t*) network_pdu);
202     } else {
203         printf("[!] Unhandled Control message with opcode %02x\n", opcode);
204         // done
205         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) network_pdu);
206     }
207 }
208 
209 static void mesh_upper_transport_process_unsegmented_message_done(mesh_network_pdu_t *network_pdu){
210     crypto_active = 0;
211     if (mesh_network_control(network_pdu)) {
212         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) network_pdu);
213     } else {
214         mesh_network_pdu_free(network_pdu);
215         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) incoming_network_pdu_raw);
216         incoming_network_pdu_raw = NULL;
217     }
218     mesh_transport_run();
219 }
220 
221 static void mesh_upper_transport_process_segmented_message_done(mesh_transport_pdu_t *transport_pdu){
222     crypto_active = 0;
223     if (mesh_transport_ctl(transport_pdu)) {
224         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)transport_pdu);
225     } else {
226         mesh_transport_pdu_free(transport_pdu);
227         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)incoming_transport_pdu_raw);
228         incoming_transport_pdu_raw = NULL;
229     }
230     mesh_transport_run();
231 }
232 
233 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
234     // get IV Index and IVI
235     uint32_t iv_index = mesh_get_iv_index();
236     int ivi = ivi_nid >> 7;
237 
238     // if least significant bit differs, use previous IV Index
239     if ((iv_index & 1 ) ^ ivi){
240         iv_index--;
241     }
242     return iv_index;
243 }
244 
245 static void transport_unsegmented_setup_nonce(uint8_t * nonce, const mesh_network_pdu_t * network_pdu){
246     nonce[1] = 0x00;    // SZMIC if a Segmented Access message or 0 for all other message formats
247     memcpy(&nonce[2], &network_pdu->data[2], 7);
248     big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(network_pdu->data[0]));
249 }
250 
251 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_transport_pdu_t * transport_pdu){
252     nonce[1] = transport_pdu->transmic_len == 8 ? 0x80 : 0x00;
253     memcpy(&nonce[2], &transport_pdu->network_header[2], 7);
254     big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(transport_pdu->network_header[0]));
255 }
256 
257 static void transport_unsegmented_setup_application_nonce(uint8_t * nonce, const mesh_network_pdu_t * network_pdu){
258     nonce[0] = 0x01;
259     transport_unsegmented_setup_nonce(nonce, network_pdu);
260     mesh_print_hex("AppNonce", nonce, 13);
261 }
262 
263 static void transport_unsegmented_setup_device_nonce(uint8_t * nonce, const mesh_network_pdu_t * network_pdu){
264     nonce[0] = 0x02;
265     transport_unsegmented_setup_nonce(nonce, network_pdu);
266     mesh_print_hex("DeviceNonce", nonce, 13);
267 }
268 
269 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_transport_pdu_t * transport_pdu){
270     nonce[0] = 0x01;
271     transport_segmented_setup_nonce(nonce, transport_pdu);
272     mesh_print_hex("AppNonce", nonce, 13);
273 }
274 
275 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_transport_pdu_t * transport_pdu){
276     nonce[0] = 0x02;
277     transport_segmented_setup_nonce(nonce, transport_pdu);
278     mesh_print_hex("DeviceNonce", nonce, 13);
279 }
280 
281 static void mesh_upper_transport_validate_unsegmented_message_ccm(void * arg){
282     UNUSED(arg);
283 
284     uint8_t * lower_transport_pdu = mesh_network_pdu_data(incoming_network_pdu_decoded);
285     uint8_t trans_mic_len = 4;
286 
287     // store TransMIC
288     uint8_t trans_mic[8];
289     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
290     mesh_print_hex("TransMIC", trans_mic, trans_mic_len);
291 
292     uint8_t * upper_transport_pdu     = mesh_network_pdu_data(incoming_network_pdu_decoded) + 1;
293     uint8_t   upper_transport_pdu_len = mesh_network_pdu_len(incoming_network_pdu_decoded)  - 1;
294 
295     mesh_print_hex("Decryted PDU", upper_transport_pdu, upper_transport_pdu_len - trans_mic_len);
296 
297     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len - trans_mic_len], trans_mic_len) == 0){
298         printf("TransMIC matches\n");
299 
300         // remove TransMIC from payload
301         incoming_network_pdu_decoded->len -= trans_mic_len;
302 
303         // if virtual address, update dst to pseudo_dst
304         if (mesh_network_address_virtual(mesh_network_dst(incoming_network_pdu_decoded))){
305             big_endian_store_16(incoming_network_pdu_decoded->data, 7, mesh_transport_key_it.address->pseudo_dst);
306         }
307 
308         // pass to upper layer
309         if (mesh_access_message_handler){
310             mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_network_pdu_decoded;
311             incoming_network_pdu_decoded = NULL;
312             mesh_access_message_handler(pdu);
313         } else {
314             printf("[!] Unhandled Unsegmented Access message\n");
315             // done
316             mesh_upper_transport_process_unsegmented_message_done(incoming_network_pdu_decoded);
317         }
318 
319         printf("\n");
320     } else {
321         uint8_t afk = lower_transport_pdu[0] & 0x40;
322         if (afk){
323             printf("TransMIC does not match, try next key\n");
324             mesh_upper_transport_validate_unsegmented_message();
325         } else {
326             printf("TransMIC does not match device key, done\n");
327             // done
328             mesh_upper_transport_process_unsegmented_message_done(incoming_network_pdu_decoded);
329         }
330     }
331 }
332 
333 static void mesh_upper_transport_validate_segmented_message_ccm(void * arg){
334     UNUSED(arg);
335 
336     uint8_t * upper_transport_pdu     =  incoming_transport_pdu_decoded->data;
337     uint8_t   upper_transport_pdu_len =  incoming_transport_pdu_decoded->len - incoming_transport_pdu_decoded->transmic_len;
338 
339     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
340 
341     // store TransMIC
342     uint8_t trans_mic[8];
343     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
344     mesh_print_hex("TransMIC", trans_mic, incoming_transport_pdu_decoded->transmic_len);
345 
346     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], incoming_transport_pdu_decoded->transmic_len) == 0){
347         printf("TransMIC matches\n");
348 
349         // remove TransMIC from payload
350         incoming_transport_pdu_decoded->len -= incoming_transport_pdu_decoded->transmic_len;
351 
352         // if virtual address, update dst to pseudo_dst
353         if (mesh_network_address_virtual(mesh_transport_dst(incoming_transport_pdu_decoded))){
354             big_endian_store_16(incoming_transport_pdu_decoded->network_header, 7, mesh_transport_key_it.address->pseudo_dst);
355         }
356 
357         // pass to upper layer
358         if (mesh_access_message_handler){
359             mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_transport_pdu_decoded;
360             incoming_network_pdu_decoded = NULL;
361             mesh_access_message_handler(pdu);
362         } else {
363             printf("[!] Unhandled Segmented Access/Control message\n");
364             // done
365             mesh_upper_transport_process_segmented_message_done(incoming_transport_pdu_decoded);
366         }
367 
368         printf("\n");
369 
370     } else {
371         uint8_t akf = incoming_transport_pdu_decoded->akf_aid_control & 0x40;
372         if (akf){
373             printf("TransMIC does not match, try next key\n");
374             mesh_upper_transport_validate_segmented_message();
375         } else {
376             printf("TransMIC does not match device key, done\n");
377             // done
378             mesh_upper_transport_process_segmented_message_done(incoming_transport_pdu_decoded);
379         }
380     }
381 }
382 
383 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
384     crypto_active = 0;
385     switch (pdu->pdu_type){
386         case MESH_PDU_TYPE_NETWORK:
387             mesh_upper_transport_process_unsegmented_message_done((mesh_network_pdu_t *) pdu);
388             break;
389         case MESH_PDU_TYPE_TRANSPORT:
390             mesh_upper_transport_process_segmented_message_done((mesh_transport_pdu_t *) pdu);
391             break;
392         default:
393             break;
394     }
395 }
396 
397 static void mesh_upper_transport_validate_segmented_message_digest(void * arg){
398     UNUSED(arg);
399     uint8_t   upper_transport_pdu_len      = incoming_transport_pdu_raw->len - incoming_transport_pdu_raw->transmic_len;
400     uint8_t * upper_transport_pdu_data_in  = incoming_transport_pdu_raw->data;
401     uint8_t * upper_transport_pdu_data_out = incoming_transport_pdu_decoded->data;
402     btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_in, upper_transport_pdu_data_out, &mesh_upper_transport_validate_segmented_message_ccm, NULL);
403 }
404 
405 static void mesh_upper_transport_validate_unsegmented_message_digest(void * arg){
406     UNUSED(arg);
407     uint8_t   trans_mic_len = 4;
408     uint8_t   lower_transport_pdu_len      = incoming_network_pdu_raw->len - 9;
409     uint8_t * upper_transport_pdu_data_in  = &incoming_network_pdu_raw->data[10];
410     uint8_t * upper_transport_pdu_data_out = &incoming_network_pdu_decoded->data[10];
411     uint8_t   upper_transport_pdu_len      = lower_transport_pdu_len - 1 - trans_mic_len;
412     btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_in, upper_transport_pdu_data_out, &mesh_upper_transport_validate_unsegmented_message_ccm, NULL);
413 }
414 
415 static void mesh_upper_transport_validate_unsegmented_message(void){
416 
417     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
418         printf("No valid transport key found\n");
419         mesh_upper_transport_process_unsegmented_message_done(incoming_network_pdu_decoded);
420         return;
421     }
422     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
423     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
424 
425     if (message_key->akf){
426         transport_unsegmented_setup_application_nonce(application_nonce, incoming_network_pdu_raw);
427     } else {
428         transport_unsegmented_setup_device_nonce(application_nonce, incoming_network_pdu_raw);
429     }
430 
431     // store application / device key index
432     mesh_print_hex("AppOrDevKey", message_key->key, 16);
433     incoming_network_pdu_decoded->appkey_index = message_key->appkey_index;
434 
435     // unsegmented message have TransMIC of 32 bit
436     uint8_t trans_mic_len = 4;
437     printf("Unsegmented Access message with TransMIC len 4\n");
438 
439     uint8_t   lower_transport_pdu_len = incoming_network_pdu_raw->len - 9;
440     uint8_t * upper_transport_pdu_data = &incoming_network_pdu_raw->data[10];
441     uint8_t   upper_transport_pdu_len  = lower_transport_pdu_len - 1 - trans_mic_len;
442 
443     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
444 
445     // decrypt ccm
446     crypto_active = 1;
447     uint16_t aad_len  = 0;
448     if (mesh_network_address_virtual(mesh_network_dst(incoming_network_pdu_decoded))){
449         aad_len  = 16;
450     }
451     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, trans_mic_len);
452     if (aad_len){
453         btstack_crypto_ccm_digest(&ccm, (uint8_t*) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_unsegmented_message_digest, NULL);
454     } else {
455         mesh_upper_transport_validate_unsegmented_message_digest(incoming_network_pdu_decoded);
456     }
457 }
458 
459 static void mesh_upper_transport_validate_segmented_message(void){
460     uint8_t * upper_transport_pdu_data =  incoming_transport_pdu_decoded->data;
461     uint8_t   upper_transport_pdu_len  =  incoming_transport_pdu_decoded->len - incoming_transport_pdu_decoded->transmic_len;
462 
463     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
464         printf("No valid transport key found\n");
465         mesh_upper_transport_process_segmented_message_done(incoming_transport_pdu_decoded);
466         return;
467     }
468     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
469     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
470 
471     if (message_key->akf){
472         transport_segmented_setup_application_nonce(application_nonce, incoming_transport_pdu_raw);
473     } else {
474         transport_segmented_setup_device_nonce(application_nonce, incoming_transport_pdu_raw);
475     }
476 
477     // store application / device key index
478     mesh_print_hex("AppOrDevKey", message_key->key, 16);
479     incoming_transport_pdu_decoded->appkey_index = message_key->appkey_index;
480 
481     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
482 
483     // decrypt ccm
484     crypto_active = 1;
485     uint16_t aad_len  = 0;
486     if (mesh_network_address_virtual(mesh_transport_dst(incoming_transport_pdu_decoded))){
487         aad_len  = 16;
488     }
489     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, incoming_transport_pdu_decoded->transmic_len);
490 
491     if (aad_len){
492         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_segmented_message_digest, NULL);
493     } else {
494         mesh_upper_transport_validate_segmented_message_digest(NULL);
495     }
496 }
497 
498 static void mesh_upper_transport_process_unsegmented_access_message(void){
499     // copy original pdu
500     incoming_network_pdu_decoded->len = incoming_network_pdu_raw->len;
501     memcpy(incoming_network_pdu_decoded->data, incoming_network_pdu_raw->data, incoming_network_pdu_decoded->len);
502 
503     //
504     uint8_t * lower_transport_pdu     = &incoming_network_pdu_raw->data[9];
505     uint8_t   lower_transport_pdu_len = incoming_network_pdu_raw->len - 9;
506 
507     mesh_print_hex("Lower Transport network pdu", &incoming_network_pdu_raw->data[9], lower_transport_pdu_len);
508 
509     uint8_t aid =  lower_transport_pdu[0] & 0x3f;
510     uint8_t akf = (lower_transport_pdu[0] & 0x40) >> 6;
511     printf("AKF: %u\n",   akf);
512     printf("AID: %02x\n", aid);
513 
514     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_network_dst(incoming_network_pdu_decoded),
515             incoming_network_pdu_decoded->netkey_index, akf, aid);
516     mesh_upper_transport_validate_unsegmented_message();
517 }
518 
519 static void mesh_upper_transport_process_message(void){
520     // copy original pdu
521     memcpy(incoming_transport_pdu_decoded, incoming_transport_pdu_raw, sizeof(mesh_transport_pdu_t));
522 
523     //
524     uint8_t * upper_transport_pdu     =  incoming_transport_pdu_decoded->data;
525     uint8_t   upper_transport_pdu_len =  incoming_transport_pdu_decoded->len - incoming_transport_pdu_decoded->transmic_len;
526     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
527 
528     uint8_t aid =  incoming_transport_pdu_decoded->akf_aid_control & 0x3f;
529     uint8_t akf = (incoming_transport_pdu_decoded->akf_aid_control & 0x40) >> 6;
530 
531     printf("AKF: %u\n",   akf);
532     printf("AID: %02x\n", aid);
533 
534     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_transport_dst(incoming_transport_pdu_decoded),
535             incoming_transport_pdu_decoded->netkey_index, akf, aid);
536     mesh_upper_transport_validate_segmented_message();
537 }
538 
539 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
540     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
541     mesh_transport_run();
542 }
543 
544 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
545     mesh_network_pdu_t * network_pdu;
546     mesh_transport_pdu_t * transport_pdu;
547     switch (pdu->pdu_type) {
548         case MESH_PDU_TYPE_NETWORK:
549             network_pdu = (mesh_network_pdu_t *) pdu;
550             mesh_network_pdu_free(network_pdu);
551             break;
552         case MESH_PDU_TYPE_TRANSPORT:
553             transport_pdu = (mesh_transport_pdu_t *) pdu;
554             mesh_transport_pdu_free(transport_pdu);
555             break;
556         default:
557             break;
558     }
559 }
560 
561 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
562     switch (callback_type){
563         case MESH_TRANSPORT_PDU_RECEIVED:
564             mesh_upper_transport_message_received(pdu);
565             break;
566         case MESH_TRANSPORT_PDU_SENT:
567             // notify upper layer (or just free pdu)
568             if (higher_layer_handler){
569                 higher_layer_handler(callback_type, status, pdu);
570             } else {
571                 mesh_upper_transport_pdu_free(pdu);
572             }
573             break;
574         default:
575             break;
576     }
577 }
578 static void mesh_upper_transport_send_unsegmented_access_pdu_ccm(void * arg){
579     crypto_active = 0;
580 
581     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
582     uint8_t * upper_transport_pdu     = mesh_network_pdu_data(network_pdu) + 1;
583     uint8_t   upper_transport_pdu_len = mesh_network_pdu_len(network_pdu)  - 1;
584     mesh_print_hex("EncAccessPayload", upper_transport_pdu, upper_transport_pdu_len);
585     // store TransMIC
586     btstack_crypto_ccm_get_authentication_value(&ccm, &upper_transport_pdu[upper_transport_pdu_len]);
587     mesh_print_hex("TransMIC", &upper_transport_pdu[upper_transport_pdu_len], 4);
588     network_pdu->len += 4;
589     mesh_print_hex("UpperTransportPDU", upper_transport_pdu, network_pdu->len);
590     // send network pdu
591     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
592 }
593 
594 static void mesh_upper_transport_send_segmented_access_pdu_ccm(void * arg){
595     crypto_active = 0;
596 
597     mesh_transport_pdu_t * transport_pdu = (mesh_transport_pdu_t *) arg;
598     mesh_print_hex("EncAccessPayload", transport_pdu->data, transport_pdu->len);
599     // store TransMIC
600     btstack_crypto_ccm_get_authentication_value(&ccm, &transport_pdu->data[transport_pdu->len]);
601     mesh_print_hex("TransMIC", &transport_pdu->data[transport_pdu->len], transport_pdu->transmic_len);
602     transport_pdu->len += transport_pdu->transmic_len;
603     mesh_print_hex("UpperTransportPDU", transport_pdu->data, transport_pdu->len);
604     mesh_lower_transport_send_pdu((mesh_pdu_t*) transport_pdu);
605 }
606 
607 static uint8_t mesh_upper_transport_setup_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
608                           const uint8_t * control_pdu_data, uint16_t control_pdu_len){
609 
610     printf("[+] Upper transport, setup unsegmented Control PDU (opcode %02x): \n", opcode);
611     printf_hexdump(control_pdu_data, control_pdu_len);
612 
613     if (control_pdu_len > 11) return 1;
614 
615     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
616     if (!network_key) return 1;
617 
618     uint8_t transport_pdu_data[12];
619     transport_pdu_data[0] = opcode;
620     memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
621     uint16_t transport_pdu_len = control_pdu_len + 1;
622 
623     mesh_print_hex("LowerTransportPDU", transport_pdu_data, transport_pdu_len);
624     // setup network_pdu
625     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, mesh_sequence_number_next(), src, dest, transport_pdu_data, transport_pdu_len);
626 
627     return 0;
628 }
629 
630 static uint8_t mesh_upper_transport_setup_segmented_control_pdu(mesh_transport_pdu_t * transport_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
631                           const uint8_t * control_pdu_data, uint16_t control_pdu_len){
632 
633     printf("[+] Upper transport, setup segmented Control PDU (opcode %02x): \n", opcode);
634     printf_hexdump(control_pdu_data, control_pdu_len);
635 
636     if (control_pdu_len > 256) return 1;
637 
638     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
639     if (!network_key) return 1;
640 
641     uint32_t seq = mesh_sequence_number_next();
642 
643     memcpy(transport_pdu->data, control_pdu_data, control_pdu_len);
644     transport_pdu->len = control_pdu_len;
645     transport_pdu->netkey_index = netkey_index;
646     transport_pdu->akf_aid_control = opcode;
647     transport_pdu->transmic_len = 0;    // no TransMIC for control
648     mesh_transport_set_nid_ivi(transport_pdu, network_key->nid);
649     mesh_transport_set_seq(transport_pdu, seq);
650     mesh_transport_set_src(transport_pdu, src);
651     mesh_transport_set_dest(transport_pdu, dest);
652     mesh_transport_set_ctl_ttl(transport_pdu, 0x80 | ttl);
653 
654     return 0;
655 }
656 
657 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
658                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
659     switch (pdu->pdu_type){
660         case MESH_PDU_TYPE_NETWORK:
661             return mesh_upper_transport_setup_unsegmented_control_pdu((mesh_network_pdu_t *) pdu, netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
662         case MESH_PDU_TYPE_TRANSPORT:
663             return mesh_upper_transport_setup_segmented_control_pdu((mesh_transport_pdu_t *) pdu, netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
664         default:
665             return 1;
666     }
667 }
668 
669 static uint8_t mesh_upper_transport_setup_unsegmented_access_pdu_header(mesh_network_pdu_t * network_pdu, uint16_t netkey_index,
670         uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest){
671 
672     // get app or device key
673     const mesh_transport_key_t * appkey;
674     appkey = mesh_transport_key_get(appkey_index);
675     if (appkey == NULL){
676         printf("appkey_index %x unknown\n", appkey_index);
677         return 1;
678     }
679     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
680 
681     // lookup network by netkey_index
682     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
683     if (!network_key) return 1;
684 
685     network_pdu->data[9] = akf_aid;
686     // setup network_pdu
687     mesh_network_setup_pdu_header(network_pdu, netkey_index, network_key->nid, 0, ttl, mesh_sequence_number_next(), src, dest);
688     network_pdu->appkey_index = appkey_index;
689     return 0;
690 }
691 
692 static uint8_t mesh_upper_transport_setup_unsegmented_access_pdu(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
693                                                        const uint8_t * access_pdu_data, uint8_t access_pdu_len){
694 
695     int status = mesh_upper_transport_setup_unsegmented_access_pdu_header(network_pdu, netkey_index, appkey_index, ttl, src, dest);
696     if (status) return status;
697 
698     printf("[+] Upper transport, setup unsegmented Access PDU - seq %06x\n", mesh_network_seq(network_pdu));
699     mesh_print_hex("Access Payload", access_pdu_data, access_pdu_len);
700 
701     // store in transport pdu
702     memcpy(&network_pdu->data[10], access_pdu_data, access_pdu_len);
703     network_pdu->len = 10 + access_pdu_len;
704     return 0;
705 }
706 
707 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_transport_pdu_t * transport_pdu, uint16_t netkey_index,
708     uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
709 
710     // get app or device key
711     const mesh_transport_key_t *appkey;
712     appkey = mesh_transport_key_get(appkey_index);
713     if (appkey == NULL) {
714         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
715         return 1;
716     }
717     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
718 
719     // lookup network by netkey_index
720     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
721     if (!network_key) return 1;
722     if (network_key == NULL) {
723         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
724         return 1;
725     }
726 
727     const uint8_t trans_mic_len = szmic ? 8 : 4;
728 
729     // lower transport will call next sequence number. Only peek here to use same seq for access payload encryption as well as for first network pdu (unit test)
730     uint32_t seq = mesh_sequence_number_peek();
731 
732     // store in transport pdu
733     transport_pdu->transmic_len = trans_mic_len;
734     transport_pdu->netkey_index = netkey_index;
735     transport_pdu->appkey_index = appkey_index;
736     transport_pdu->akf_aid_control = akf_aid;
737     mesh_transport_set_nid_ivi(transport_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
738     mesh_transport_set_seq(transport_pdu, seq);
739     mesh_transport_set_src(transport_pdu, src);
740     mesh_transport_set_dest(transport_pdu, dest);
741     mesh_transport_set_ctl_ttl(transport_pdu, ttl);
742     return 0;
743 }
744 
745 
746 static uint8_t mesh_upper_transport_setup_segmented_access_pdu(mesh_transport_pdu_t * transport_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
747                           uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
748     int status = mesh_upper_transport_setup_segmented_access_pdu_header(transport_pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
749     if (status) return status;
750 
751     // store in transport pdu
752     memcpy(transport_pdu->data, access_pdu_data, access_pdu_len);
753     transport_pdu->len = access_pdu_len;
754 
755     printf("[+] Upper transport, setup segmented Access PDU - seq %06x, szmic %u, iv_index %08x\n", mesh_transport_seq(transport_pdu), szmic, mesh_get_iv_index_for_tx());
756     mesh_print_hex("Access Payload", transport_pdu->data, transport_pdu->len);
757     return 0;
758 }
759 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
760                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
761     switch (pdu->pdu_type){
762         case MESH_PDU_TYPE_NETWORK:
763             return mesh_upper_transport_setup_unsegmented_access_pdu_header((mesh_network_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest);
764         case MESH_PDU_TYPE_TRANSPORT:
765             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_transport_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
766         default:
767             return 1;
768     }
769 }
770 
771 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
772                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
773                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
774     switch (pdu->pdu_type){
775         case MESH_PDU_TYPE_NETWORK:
776             return mesh_upper_transport_setup_unsegmented_access_pdu((mesh_network_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, access_pdu_data, access_pdu_len);
777         case MESH_PDU_TYPE_TRANSPORT:
778             return mesh_upper_transport_setup_segmented_access_pdu((mesh_transport_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic, access_pdu_data, access_pdu_len);
779         default:
780             return 1;
781     }
782 }
783 
784 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
785     mesh_lower_transport_send_pdu((mesh_pdu_t*) pdu);
786 }
787 
788 static void mesh_upper_transport_send_unsegmented_access_pdu_digest(void * arg){
789     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
790     uint8_t * access_pdu_data = mesh_network_pdu_data(network_pdu) + 1;
791     uint16_t  access_pdu_len  = mesh_network_pdu_len(network_pdu)  - 1;
792     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, access_pdu_data, access_pdu_data, &mesh_upper_transport_send_unsegmented_access_pdu_ccm, network_pdu);
793 }
794 
795 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
796     // Device Key is fixed
797     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
798         return mesh_transport_key_get(appkey_index);
799     }
800 
801     // Get key refresh state from subnet
802     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
803     if (subnet == NULL) return NULL;
804 
805     // identify old and new app keys for given appkey_index
806     mesh_transport_key_t * old_key = NULL;
807     mesh_transport_key_t * new_key = NULL;
808     mesh_transport_key_iterator_t it;
809     mesh_transport_key_iterator_init(&it, netkey_index);
810     while (mesh_transport_key_iterator_has_more(&it)){
811         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
812         if (transport_key->appkey_index != appkey_index) continue;
813         if (transport_key->old_key == 0) {
814             new_key = transport_key;
815         } else {
816             old_key = transport_key;
817         }
818     }
819 
820     // if no key is marked as old, just use the current one
821     if (old_key == NULL) return new_key;
822 
823     // use new key if it exists in phase two
824     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
825         return new_key;
826     } else {
827         return old_key;
828     }
829 }
830 
831 static void mesh_upper_transport_send_unsegmented_access_pdu(mesh_network_pdu_t * network_pdu){
832 
833     // if dst is virtual address, lookup label uuid and hash
834     uint16_t aad_len = 0;
835     mesh_virtual_address_t * virtual_address = NULL;
836     uint16_t dst = mesh_network_dst(network_pdu);
837     if (mesh_network_address_virtual(dst)){
838         virtual_address = mesh_virtual_address_for_pseudo_dst(dst);
839         if (!virtual_address){
840             printf("No virtual address register for pseudo dst %4x\n", dst);
841             btstack_memory_mesh_network_pdu_free(network_pdu);
842             return;
843         }
844         aad_len = 16;
845         big_endian_store_16(network_pdu->data, 7, virtual_address->hash);
846     }
847 
848     // setup nonce
849     uint16_t appkey_index = network_pdu->appkey_index;
850     if (appkey_index == MESH_DEVICE_KEY_INDEX){
851         transport_unsegmented_setup_device_nonce(application_nonce, network_pdu);
852     } else {
853         transport_unsegmented_setup_application_nonce(application_nonce, network_pdu);
854     }
855 
856     // get app or device key
857     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(network_pdu->netkey_index, appkey_index);
858     mesh_print_hex("AppOrDevKey", appkey->key, 16);
859 
860     // encrypt ccm
861     uint8_t   trans_mic_len = 4;
862     uint16_t  access_pdu_len  = mesh_network_pdu_len(network_pdu)  - 1;
863     crypto_active = 1;
864 
865     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, trans_mic_len);
866     if (virtual_address){
867         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
868         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16, &mesh_upper_transport_send_unsegmented_access_pdu_digest, network_pdu);
869     } else {
870         mesh_upper_transport_send_unsegmented_access_pdu_digest(network_pdu);
871     }
872 }
873 
874 static void mesh_upper_transport_send_segmented_access_pdu_digest(void *arg){
875     mesh_transport_pdu_t * transport_pdu = (mesh_transport_pdu_t *) arg;
876     uint16_t  access_pdu_len  = transport_pdu->len;
877     uint8_t * access_pdu_data = transport_pdu->data;
878     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len,access_pdu_data, access_pdu_data, &mesh_upper_transport_send_segmented_access_pdu_ccm, transport_pdu);
879 }
880 
881 static void mesh_upper_transport_send_segmented_access_pdu(mesh_transport_pdu_t * transport_pdu){
882 
883     // if dst is virtual address, lookup label uuid and hash
884     uint16_t aad_len = 0;
885     mesh_virtual_address_t * virtual_address = NULL;
886     uint16_t dst = mesh_transport_dst(transport_pdu);
887     if (mesh_network_address_virtual(dst)){
888         virtual_address = mesh_virtual_address_for_pseudo_dst(dst);
889         if (!virtual_address){
890             printf("No virtual address register for pseudo dst %4x\n", dst);
891             btstack_memory_mesh_transport_pdu_free(transport_pdu);
892             return;
893         }
894         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
895         // printf_hexdump(virtual_address->label_uuid, 16);
896         aad_len = 16;
897         big_endian_store_16(transport_pdu->network_header, 7, virtual_address->hash);
898     }
899 
900     // setup nonce - uses dst, so after pseudo address translation
901     uint16_t appkey_index = transport_pdu->appkey_index;
902     if (appkey_index == MESH_DEVICE_KEY_INDEX){
903         transport_segmented_setup_device_nonce(application_nonce, transport_pdu);
904     } else {
905         transport_segmented_setup_application_nonce(application_nonce, transport_pdu);
906     }
907 
908     // get app or device key
909     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(transport_pdu->netkey_index, appkey_index);
910     mesh_print_hex("AppOrDevKey", appkey->key, 16);
911 
912     // encrypt ccm
913     uint8_t   transmic_len    = transport_pdu->transmic_len;
914     uint16_t  access_pdu_len  = transport_pdu->len;
915     crypto_active = 1;
916     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
917     if (virtual_address){
918         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
919         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16, &mesh_upper_transport_send_segmented_access_pdu_digest, transport_pdu);
920     } else {
921         mesh_upper_transport_send_segmented_access_pdu_digest(transport_pdu);
922     }
923 }
924 
925 void mesh_upper_transport_send_access_pdu(mesh_pdu_t * pdu){
926     switch (pdu->pdu_type){
927         case MESH_PDU_TYPE_NETWORK:
928             mesh_upper_transport_send_unsegmented_access_pdu((mesh_network_pdu_t *) pdu);
929             break;
930         case MESH_PDU_TYPE_TRANSPORT:
931             mesh_upper_transport_send_segmented_access_pdu((mesh_transport_pdu_t *) pdu);
932             break;
933         default:
934             break;
935     }
936 }
937 
938 void mesh_upper_transport_register_access_message_handler(void (*callback)(mesh_pdu_t *pdu)){
939     mesh_access_message_handler = callback;
940 }
941 
942 void mesh_upper_transport_register_control_message_handler(void (*callback)(mesh_pdu_t *pdu)){
943     mesh_control_message_handler = callback;
944 }
945 
946 void mesh_upper_transport_set_higher_layer_handler(void (*pdu_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu)){
947     higher_layer_handler = pdu_handler;
948 }
949 
950 void mesh_upper_transport_init(){
951     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
952 }
953 
954 static void mesh_transport_run(void){
955     while(!btstack_linked_list_empty(&upper_transport_incoming)){
956 
957         if (crypto_active) return;
958 
959         // peek at next message
960         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_incoming);
961         mesh_transport_pdu_t * transport_pdu;
962         mesh_network_pdu_t   * network_pdu;
963         switch (pdu->pdu_type){
964             case MESH_PDU_TYPE_NETWORK:
965                 network_pdu = (mesh_network_pdu_t *) pdu;
966                 // control?
967                 if (mesh_network_control(network_pdu)) {
968                     (void) btstack_linked_list_pop(&upper_transport_incoming);
969                     mesh_upper_unsegmented_control_message_received(network_pdu);
970                 } else {
971                     incoming_network_pdu_decoded = mesh_network_pdu_get();
972                     if (!incoming_network_pdu_decoded) return;
973                     // get encoded network pdu and start processing
974                     incoming_network_pdu_raw = network_pdu;
975                     (void) btstack_linked_list_pop(&upper_transport_incoming);
976                     mesh_upper_transport_process_unsegmented_access_message();
977                 }
978                 break;
979             case MESH_PDU_TYPE_TRANSPORT:
980                 transport_pdu = (mesh_transport_pdu_t *) pdu;
981                 uint8_t ctl = mesh_transport_ctl(transport_pdu);
982                 if (ctl){
983                     printf("Ignoring Segmented Control Message\n");
984                     (void) btstack_linked_list_pop(&upper_transport_incoming);
985                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) transport_pdu);
986                 } else {
987                     incoming_transport_pdu_decoded = mesh_transport_pdu_get();
988                     if (!incoming_transport_pdu_decoded) return;
989                     // get encoded transport pdu and start processing
990                     incoming_transport_pdu_raw = transport_pdu;
991                     (void) btstack_linked_list_pop(&upper_transport_incoming);
992                     mesh_upper_transport_process_message();
993                 }
994                 break;
995             default:
996                 break;
997         }
998     }
999 }
1000