xref: /btstack/src/mesh/mesh_upper_transport.c (revision 8fb906aa4a0866baf395e5b5461edd21684558f6)
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 #include "btstack_debug.h"
49 #include "btstack_bool.h"
50 
51 #include "mesh/beacon.h"
52 #include "mesh/mesh_iv_index_seq_number.h"
53 #include "mesh/mesh_keys.h"
54 #include "mesh/mesh_lower_transport.h"
55 #include "mesh/mesh_peer.h"
56 #include "mesh/mesh_virtual_addresses.h"
57 
58 // TODO: extract mesh_pdu functions into lower transport or network
59 #include "mesh/mesh_access.h"
60 
61 // combined key x address iterator for upper transport decryption
62 
63 typedef struct {
64     // state
65     mesh_transport_key_iterator_t  key_it;
66     mesh_virtual_address_iterator_t address_it;
67     // elements
68     const mesh_transport_key_t *   key;
69     const mesh_virtual_address_t * address;
70     // address - might be virtual
71     uint16_t dst;
72     // key info
73 } mesh_transport_key_and_virtual_address_iterator_t;
74 
75 static void mesh_upper_transport_validate_segmented_message(void);
76 static void mesh_upper_transport_run(void);
77 
78 // upper transport callbacks - in access layer
79 static void (*mesh_access_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
80 static void (*mesh_control_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
81 
82 //
83 static int crypto_active;
84 static uint8_t application_nonce[13];
85 static btstack_crypto_ccm_t ccm;
86 
87 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
88 
89 static mesh_access_pdu_t *   incoming_access_pdu_encrypted;
90 static mesh_access_pdu_t *   incoming_access_pdu_decrypted;
91 
92 static mesh_control_pdu_t *  incoming_control_pdu;
93 
94 static mesh_access_pdu_t     incoming_access_pdu_encrypted_singleton;
95 
96 static union {
97     mesh_control_pdu_t    control;
98     mesh_access_pdu_t     access;
99 } incoming_pdu_singleton;
100 
101 // incoming unsegmented (network) and segmented (transport) control and access messages
102 static btstack_linked_list_t upper_transport_incoming;
103 
104 // outgoing unsegmented and segmented control and access messages
105 static btstack_linked_list_t upper_transport_outgoing;
106 
107 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
108 static btstack_linked_list_t upper_transport_outgoing_active;
109 
110 // TODO: higher layer define used for assert
111 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
112 
113 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
114     printf("%-20s ", name);
115     printf_hexdump(data, len);
116 }
117 // static void mesh_print_x(const char * name, uint32_t value){
118 //     printf("%20s: 0x%x", name, (int) value);
119 // }
120 
121 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
122                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
123                                                                  uint8_t aid) {
124     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
125     // config
126     it->dst   = dst;
127     // init elements
128     it->key     = NULL;
129     it->address = NULL;
130     // init element iterators
131     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
132     // init address iterator
133     if (mesh_network_address_virtual(it->dst)){
134         mesh_virtual_address_iterator_init(&it->address_it, dst);
135         // get first key
136         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
137             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
138         }
139     }
140 }
141 
142 // cartesian product: keys x addressses
143 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
144     if (mesh_network_address_virtual(it->dst)) {
145         // find next valid entry
146         while (true){
147             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
148             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
149             // get next key
150             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
151             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
152         }
153     } else {
154         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
155     }
156 }
157 
158 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
159     if (mesh_network_address_virtual(it->dst)) {
160         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
161     } else {
162         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
163     }
164 }
165 
166 // UPPER TRANSPORT
167 
168 uint16_t mesh_access_dst(mesh_access_pdu_t * access_pdu){
169     return big_endian_read_16(access_pdu->network_header, 7);
170 }
171 
172 uint16_t mesh_access_ctl(mesh_access_pdu_t * access_pdu){
173     return access_pdu->network_header[1] >> 7;
174 }
175 
176 uint32_t mesh_access_seq(mesh_access_pdu_t * access_pdu){
177     return big_endian_read_24(access_pdu->network_header, 2);
178 }
179 
180 void mesh_access_set_nid_ivi(mesh_access_pdu_t * access_pdu, uint8_t nid_ivi){
181     access_pdu->network_header[0] = nid_ivi;
182 }
183 void mesh_access_set_ctl_ttl(mesh_access_pdu_t * access_pdu, uint8_t ctl_ttl){
184     access_pdu->network_header[1] = ctl_ttl;
185 }
186 void mesh_access_set_seq(mesh_access_pdu_t * access_pdu, uint32_t seq){
187     big_endian_store_24(access_pdu->network_header, 2, seq);
188 }
189 void mesh_access_set_src(mesh_access_pdu_t * access_pdu, uint16_t src){
190     big_endian_store_16(access_pdu->network_header, 5, src);
191 }
192 void mesh_access_set_dest(mesh_access_pdu_t * access_pdu, uint16_t dest){
193     big_endian_store_16(access_pdu->network_header, 7, dest);
194 }
195 
196 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
197     // assemble payload
198     btstack_linked_list_iterator_t it;
199     btstack_linked_list_iterator_init(&it, segments);
200     while (btstack_linked_list_iterator_has_next(&it)) {
201         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
202         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
203         // get segment n
204         uint8_t *lower_transport_pdu = mesh_network_pdu_data(segment);
205         uint8_t seg_o = (big_endian_read_16(lower_transport_pdu, 2) >> 5) & 0x001f;
206         uint8_t *segment_data = &lower_transport_pdu[4];
207         (void) memcpy(&buffer[seg_o * segment_len], segment_data, segment_len);
208     }
209 }
210 
211 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
212     // assemble payload
213     btstack_linked_list_iterator_t it;
214     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
215     uint16_t offset = 0;
216     while (btstack_linked_list_iterator_has_next(&it)) {
217         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
218         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
219         btstack_assert((offset + segment->len) <= buffer_len);
220         (void) memcpy(&buffer[offset], segment->data, segment->len);
221         offset += segment->len;
222     }
223     return offset;
224 }
225 
226 // store payload in provided list of network pdus
227 static void mesh_segmented_store_payload(const uint8_t * payload, uint16_t payload_len, btstack_linked_list_t * in_segments, btstack_linked_list_t * out_segments){
228     uint16_t payload_offset = 0;
229     uint16_t bytes_current_segment = 0;
230     mesh_network_pdu_t * network_pdu = NULL;
231     while (payload_offset < payload_len){
232         if (bytes_current_segment == 0){
233             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
234             btstack_assert(network_pdu != NULL);
235             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
236             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
237         }
238         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
239         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
240         bytes_current_segment -= bytes_to_copy;
241         network_pdu->len += bytes_to_copy;
242         payload_offset += bytes_to_copy;
243     }
244 }
245 
246 // tries allocate and add enough segments to store payload of given size
247 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
248     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
249     while (storage_size < payload_len){
250         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
251         if (network_pdu == NULL) break;
252         storage_size += MESH_NETWORK_PAYLOAD_MAX;
253         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
254     }
255     return (storage_size >= payload_len);
256 }
257 
258 // stub lower transport
259 
260 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
261     printf("List: %s:\n", name);
262     btstack_linked_list_iterator_t it;
263     btstack_linked_list_iterator_init(&it, list);
264     while (btstack_linked_list_iterator_has_next(&it)){
265         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
266         printf("- %p\n", pdu);
267         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
268     }
269 }
270 
271 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
272     while (!btstack_linked_list_empty(list)){
273         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
274     }
275 }
276 
277 void mesh_upper_transport_dump(void){
278     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
279 }
280 
281 void mesh_upper_transport_reset(void){
282     crypto_active = 0;
283     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
284 }
285 
286 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
287     // Device Key is fixed
288     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
289         return mesh_transport_key_get(appkey_index);
290     }
291 
292     // Get key refresh state from subnet
293     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
294     if (subnet == NULL) return NULL;
295 
296     // identify old and new app keys for given appkey_index
297     mesh_transport_key_t * old_key = NULL;
298     mesh_transport_key_t * new_key = NULL;
299     mesh_transport_key_iterator_t it;
300     mesh_transport_key_iterator_init(&it, netkey_index);
301     while (mesh_transport_key_iterator_has_more(&it)){
302         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
303         if (transport_key->appkey_index != appkey_index) continue;
304         if (transport_key->old_key == 0) {
305             new_key = transport_key;
306         } else {
307             old_key = transport_key;
308         }
309     }
310 
311     // if no key is marked as old, just use the current one
312     if (old_key == NULL) return new_key;
313 
314     // use new key if it exists in phase two
315     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
316         return new_key;
317     } else {
318         return old_key;
319     }
320 }
321 
322 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
323     // get IV Index and IVI
324     uint32_t iv_index = mesh_get_iv_index();
325     int ivi = ivi_nid >> 7;
326 
327     // if least significant bit differs, use previous IV Index
328     if ((iv_index & 1 ) ^ ivi){
329         iv_index--;
330     }
331     return iv_index;
332 }
333 
334 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
335     mesh_access_pdu_t * access_pdu;
336     mesh_upper_transport_pdu_t * upper_pdu;
337     switch (pdu->pdu_type){
338         case MESH_PDU_TYPE_ACCESS:
339             access_pdu = (mesh_access_pdu_t *) pdu;
340             nonce[1] = access_pdu->transmic_len == 8 ? 0x80 : 0x00;
341             (void)memcpy(&nonce[2], &access_pdu->network_header[2], 7);
342             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->network_header[0]));
343             break;
344         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
345         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
346             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
347             nonce[1] = upper_pdu->transmic_len == 8 ? 0x80 : 0x00;
348             // 'network header'
349             big_endian_store_24(nonce, 2, upper_pdu->seq);
350             big_endian_store_16(nonce, 5, upper_pdu->src);
351             big_endian_store_16(nonce, 7, upper_pdu->dst);
352             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
353             break;
354         default:
355             btstack_assert(0);
356             break;
357     }
358 }
359 
360 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
361     nonce[0] = 0x01;
362     transport_segmented_setup_nonce(nonce, pdu);
363     mesh_print_hex("AppNonce", nonce, 13);
364 }
365 
366 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
367     nonce[0] = 0x02;
368     transport_segmented_setup_nonce(nonce, pdu);
369     mesh_print_hex("DeviceNonce", nonce, 13);
370 }
371 
372 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
373     crypto_active = 0;
374     btstack_assert(mesh_access_ctl(access_pdu) == 0);
375     incoming_access_pdu_encrypted = NULL;
376     mesh_upper_transport_run();
377 }
378 
379 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
380     crypto_active = 0;
381     incoming_control_pdu = NULL;
382     mesh_upper_transport_run();
383 }
384 
385 static void mesh_upper_transport_validate_segmented_message_ccm(void * arg){
386     UNUSED(arg);
387 
388     uint8_t * upper_transport_pdu     = incoming_access_pdu_decrypted->data;
389     uint8_t   upper_transport_pdu_len = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
390 
391     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
392 
393     // store TransMIC
394     uint8_t trans_mic[8];
395     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
396     mesh_print_hex("TransMIC", trans_mic, incoming_access_pdu_decrypted->transmic_len);
397 
398     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], incoming_access_pdu_decrypted->transmic_len) == 0){
399         printf("TransMIC matches\n");
400 
401         // remove TransMIC from payload
402         incoming_access_pdu_decrypted->len -= incoming_access_pdu_decrypted->transmic_len;
403 
404         // if virtual address, update dst to pseudo_dst
405         if (mesh_network_address_virtual(mesh_access_dst(incoming_access_pdu_decrypted))){
406             big_endian_store_16(incoming_access_pdu_decrypted->network_header, 7, mesh_transport_key_it.address->pseudo_dst);
407         }
408 
409         // pass to upper layer
410         btstack_assert(mesh_access_message_handler != NULL);
411         mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_access_pdu_decrypted;
412         mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
413 
414         printf("\n");
415 
416     } else {
417         uint8_t akf = incoming_access_pdu_decrypted->akf_aid_control & 0x40;
418         if (akf){
419             printf("TransMIC does not match, try next key\n");
420             mesh_upper_transport_validate_segmented_message();
421         } else {
422             printf("TransMIC does not match device key, done\n");
423             // done
424             mesh_upper_transport_process_access_message_done(incoming_access_pdu_decrypted);
425         }
426     }
427 }
428 
429 static void mesh_upper_transport_validate_segmented_message_digest(void * arg){
430     UNUSED(arg);
431     uint8_t   upper_transport_pdu_len      = incoming_access_pdu_encrypted->len - incoming_access_pdu_encrypted->transmic_len;
432     uint8_t * upper_transport_pdu_data_in  = incoming_access_pdu_encrypted->data;
433     uint8_t * upper_transport_pdu_data_out = incoming_access_pdu_decrypted->data;
434     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);
435 }
436 
437 static void mesh_upper_transport_validate_segmented_message(void){
438     uint8_t * upper_transport_pdu_data =  incoming_access_pdu_decrypted->data;
439     uint8_t   upper_transport_pdu_len  = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
440 
441     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
442         printf("No valid transport key found\n");
443         mesh_upper_transport_process_access_message_done(incoming_access_pdu_decrypted);
444         return;
445     }
446     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
447     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
448 
449     if (message_key->akf){
450         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_pdu_encrypted);
451     } else {
452         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_pdu_encrypted);
453     }
454 
455     // store application / device key index
456     mesh_print_hex("AppOrDevKey", message_key->key, 16);
457     incoming_access_pdu_decrypted->appkey_index = message_key->appkey_index;
458 
459     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
460 
461     // decrypt ccm
462     crypto_active = 1;
463     uint16_t aad_len  = 0;
464     if (mesh_network_address_virtual(mesh_access_dst(incoming_access_pdu_decrypted))){
465         aad_len  = 16;
466     }
467     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, incoming_access_pdu_decrypted->transmic_len);
468 
469     if (aad_len){
470         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_segmented_message_digest, NULL);
471     } else {
472         mesh_upper_transport_validate_segmented_message_digest(NULL);
473     }
474 }
475 
476 static void mesh_upper_transport_process_segmented_message(void){
477     // copy original pdu
478     (void)memcpy(incoming_access_pdu_decrypted, incoming_access_pdu_encrypted,
479                  sizeof(mesh_access_pdu_t));
480 
481     //
482     uint8_t * upper_transport_pdu     =  incoming_access_pdu_decrypted->data;
483     uint8_t   upper_transport_pdu_len = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
484     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
485 
486     uint8_t aid = incoming_access_pdu_decrypted->akf_aid_control & 0x3f;
487     uint8_t akf = (incoming_access_pdu_decrypted->akf_aid_control & 0x40) >> 6;
488 
489     printf("AKF: %u\n",   akf);
490     printf("AID: %02x\n", aid);
491 
492     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_access_dst(incoming_access_pdu_decrypted),
493                                                          incoming_access_pdu_decrypted->netkey_index, akf, aid);
494     mesh_upper_transport_validate_segmented_message();
495 }
496 
497 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
498     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
499     mesh_upper_transport_run();
500 }
501 
502 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
503 
504     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
505     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
506 
507     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
508     btstack_linked_list_t free_segments = segmented_pdu->segments;
509     segmented_pdu->segments = NULL;
510     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
511 
512     // copy meta
513     segmented_pdu->len = upper_pdu->len;
514     segmented_pdu->netkey_index = upper_pdu->netkey_index;
515     segmented_pdu->transmic_len = upper_pdu->transmic_len;
516     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
517     segmented_pdu->flags = upper_pdu->flags;
518 
519     // setup segmented_pdu header
520     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
521     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
522     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
523     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
524     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
525     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
526     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
527 
528     // queue up
529     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
530     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
531 
532     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
533 }
534 
535 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
536 
537     // provide segment
538     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
539 
540     // setup network pdu
541     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
542     network_pdu->data[0] = upper_pdu->ivi_nid;
543     network_pdu->data[1] = upper_pdu->ctl_ttl;
544     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
545     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
546     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
547     network_pdu->netkey_index = upper_pdu->netkey_index;
548 
549     // setup access message
550     network_pdu->data[9] = upper_pdu->akf_aid_control;
551     btstack_assert(upper_pdu->len < 15);
552     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
553     network_pdu->len = 10 + upper_pdu->len;
554     network_pdu->flags = 0;
555 
556     // queue up
557     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
558 
559     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
560 }
561 
562 static void mesh_upper_transport_send_access_ccm(void * arg){
563     crypto_active = 0;
564 
565     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
566     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
567     // store TransMIC
568     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
569     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], upper_pdu->transmic_len);
570     upper_pdu->len += upper_pdu->transmic_len;
571     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
572     switch (upper_pdu->pdu_header.pdu_type){
573         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
574             mesh_upper_transport_send_access_unsegmented(upper_pdu);
575             break;
576         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
577             mesh_upper_transport_send_access_segmented(upper_pdu);
578             break;
579         default:
580             btstack_assert(false);
581     }
582 }
583 
584 static void mesh_upper_transport_send_access_digest(void *arg){
585     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
586     uint16_t  access_pdu_len  = upper_pdu->len;
587     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
588                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
589 }
590 
591 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
592 
593     // if dst is virtual address, lookup label uuid and hash
594     uint16_t aad_len = 0;
595     mesh_virtual_address_t * virtual_address = NULL;
596     if (mesh_network_address_virtual(upper_pdu->dst)){
597         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
598         if (!virtual_address){
599             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
600             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
601             return;
602         }
603         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
604         // printf_hexdump(virtual_address->label_uuid, 16);
605         aad_len = 16;
606         upper_pdu->dst = virtual_address->hash;
607     }
608 
609     // get app or device key
610     uint16_t appkey_index = upper_pdu->appkey_index;
611     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
612     if (appkey == NULL){
613         printf("AppKey %04x not found, drop message\n", appkey_index);
614         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
615         return;
616     }
617 
618     // reserve slot
619     mesh_lower_transport_reserve_slot();
620 
621     // reserve one sequence number, which is also used to encrypt access payload
622     uint32_t seq = mesh_sequence_number_next();
623     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
624     upper_pdu->seq = seq;
625 
626     // also reserves crypto_buffer
627     crypto_active = 1;
628 
629     // flatten segmented pdu into crypto buffer
630     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
631     btstack_assert(payload_len == upper_pdu->len);
632 
633     // Dump PDU
634     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
635     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
636 
637     // setup nonce - uses dst, so after pseudo address translation
638     if (appkey_index == MESH_DEVICE_KEY_INDEX){
639         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
640     } else {
641         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
642     }
643 
644     // Dump key
645     mesh_print_hex("AppOrDevKey", appkey->key, 16);
646 
647     // encrypt ccm
648     uint8_t   transmic_len    = upper_pdu->transmic_len;
649     uint16_t  access_pdu_len  = upper_pdu->len;
650     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
651     if (virtual_address){
652         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
653         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
654                                   &mesh_upper_transport_send_access_digest, upper_pdu);
655     } else {
656         mesh_upper_transport_send_access_digest(upper_pdu);
657     }
658 }
659 
660 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
661     // reserve slot
662     mesh_lower_transport_reserve_slot();
663     // reserve sequence number
664     uint32_t seq = mesh_sequence_number_next();
665     mesh_network_pdu_set_seq(network_pdu, seq);
666     // Dump PDU
667     uint8_t opcode = network_pdu->data[9];
668     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
669     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
670 
671     // send
672      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
673 }
674 
675 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
676     // reserve slot
677     mesh_lower_transport_reserve_slot();
678     // reserve sequence number
679     uint32_t seq = mesh_sequence_number_next();
680     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
681     upper_pdu->seq = seq;
682     // Dump PDU
683     // uint8_t opcode = upper_pdu->data[0];
684     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
685     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
686     // send
687     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
688     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
689 
690     // lend segments to lower transport pdu
691     segmented_pdu->segments = upper_pdu->segments;
692     upper_pdu->segments = NULL;
693 
694     // copy meta
695     segmented_pdu->len = upper_pdu->len;
696     segmented_pdu->netkey_index = upper_pdu->netkey_index;
697     segmented_pdu->transmic_len = 0;   // no TransMIC for control
698     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
699     segmented_pdu->flags = upper_pdu->flags;
700 
701     // setup segmented_pdu header
702     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
703     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
704     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
705     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
706     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
707     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
708 
709     // queue up
710     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
711     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
712 
713     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
714 }
715 
716 static void mesh_upper_transport_run(void){
717 
718     while(!btstack_linked_list_empty(&upper_transport_incoming)){
719 
720         if (crypto_active) return;
721 
722         // get next message
723         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
724         mesh_network_pdu_t   * network_pdu;
725         mesh_segmented_pdu_t   * message_pdu;
726         switch (pdu->pdu_type){
727             case MESH_PDU_TYPE_UNSEGMENTED:
728                 network_pdu = (mesh_network_pdu_t *) pdu;
729                 // control?
730                 if (mesh_network_control(network_pdu)) {
731 
732                     incoming_control_pdu =  &incoming_pdu_singleton.control;
733                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
734                     incoming_control_pdu->len =  network_pdu->len;
735                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
736 
737                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
738 
739                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
740                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
741                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
742 
743                     // copy meta data into encrypted pdu buffer
744                     (void)memcpy(incoming_control_pdu->network_header, network_pdu->data, 9);
745 
746                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
747 
748                     // free mesh message
749                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
750 
751                     btstack_assert(mesh_control_message_handler != NULL);
752                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
753                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
754 
755                 } else {
756 
757                     incoming_access_pdu_encrypted = &incoming_access_pdu_encrypted_singleton;
758                     incoming_access_pdu_encrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
759                     incoming_access_pdu_decrypted = &incoming_pdu_singleton.access;
760 
761                     incoming_access_pdu_encrypted->netkey_index = network_pdu->netkey_index;
762                     incoming_access_pdu_encrypted->transmic_len = 4;
763 
764                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
765 
766                     incoming_access_pdu_encrypted->akf_aid_control = lower_transport_pdu[0];
767                     incoming_access_pdu_encrypted->len = network_pdu->len - 10; // 9 header + 1 AID
768                     (void)memcpy(incoming_access_pdu_encrypted->data, &lower_transport_pdu[1], incoming_access_pdu_encrypted->len);
769 
770                     // copy meta data into encrypted pdu buffer
771                     (void)memcpy(incoming_access_pdu_encrypted->network_header, network_pdu->data, 9);
772 
773                     mesh_print_hex("Assembled payload", incoming_access_pdu_encrypted->data, incoming_access_pdu_encrypted->len);
774 
775                     // free mesh message
776                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
777 
778                     // get encoded transport pdu and start processing
779                     mesh_upper_transport_process_segmented_message();
780                 }
781                 break;
782             case MESH_PDU_TYPE_SEGMENTED:
783                 message_pdu = (mesh_segmented_pdu_t *) pdu;
784                 uint8_t ctl = mesh_message_ctl(message_pdu);
785                 if (ctl){
786                     incoming_control_pdu=  &incoming_pdu_singleton.control;
787                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
788 
789                     // flatten
790                     mesh_segmented_pdu_flatten(&message_pdu->segments, 8, incoming_control_pdu->data);
791 
792                     // copy meta data into encrypted pdu buffer
793                     incoming_control_pdu->len =  message_pdu->len;
794                     incoming_control_pdu->netkey_index =  message_pdu->netkey_index;
795                     incoming_control_pdu->akf_aid_control =  message_pdu->akf_aid_control;
796                     incoming_control_pdu->flags = 0;
797                     (void)memcpy(incoming_control_pdu->network_header, message_pdu->network_header, 9);
798 
799                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
800 
801                     // free mesh message
802                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
803 
804                     btstack_assert(mesh_control_message_handler != NULL);
805                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
806                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
807 
808                 } else {
809 
810                     incoming_access_pdu_encrypted = &incoming_access_pdu_encrypted_singleton;
811                     incoming_access_pdu_encrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
812                     incoming_access_pdu_decrypted = &incoming_pdu_singleton.access;
813 
814                     // flatten
815                     mesh_segmented_pdu_flatten(&message_pdu->segments, 12, incoming_access_pdu_encrypted->data);
816 
817                     // copy meta data into encrypted pdu buffer
818                     incoming_access_pdu_encrypted->len =  message_pdu->len;
819                     incoming_access_pdu_encrypted->netkey_index =  message_pdu->netkey_index;
820                     incoming_access_pdu_encrypted->transmic_len =  message_pdu->transmic_len;
821                     incoming_access_pdu_encrypted->akf_aid_control =  message_pdu->akf_aid_control;
822                     (void)memcpy(incoming_access_pdu_encrypted->network_header, message_pdu->network_header, 9);
823 
824                     mesh_print_hex("Assembled payload", incoming_access_pdu_encrypted->data, incoming_access_pdu_encrypted->len);
825 
826                     // free mesh message
827                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
828 
829                     // get encoded transport pdu and start processing
830                     mesh_upper_transport_process_segmented_message();
831                 }
832                 break;
833             default:
834                 btstack_assert(0);
835                 break;
836         }
837     }
838 
839     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
840 
841         if (crypto_active) break;
842 
843         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
844         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
845 
846         mesh_upper_transport_pdu_t * upper_pdu;
847         mesh_segmented_pdu_t * segmented_pdu;
848         bool ok;
849 
850         switch (pdu->pdu_type){
851             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
852                 // control pdus can go through directly
853                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
854                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
855                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
856                 break;
857             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
858                 // control pdus can go through directly
859                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
860                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
861                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
862                 break;
863             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
864                 // segmented access pdus required a mesh-segmented-pdu
865                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
866                 if (upper_pdu->lower_pdu == NULL){
867                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
868                 }
869                 if (segmented_pdu == NULL) break;
870                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
871                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
872                 // and a mesh-network-pdu for each segment in upper pdu
873                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + upper_pdu->transmic_len);
874                 if (!ok) break;
875                 // all buffers available, get started
876                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
877                 mesh_upper_transport_send_access(upper_pdu);
878                 break;
879             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
880                 // unsegmented access pdus require a single mesh-network-dpu
881                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
882                 if (upper_pdu->lower_pdu == NULL){
883                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
884                 }
885                 if (upper_pdu->lower_pdu == NULL) break;
886                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
887                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
888                 break;
889             default:
890                 btstack_assert(false);
891                 break;
892         }
893     }
894 }
895 
896 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
897     btstack_linked_list_iterator_t it;
898     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
899     mesh_upper_transport_pdu_t * upper_pdu;
900     while (btstack_linked_list_iterator_has_next(&it)){
901         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
902         switch (mesh_pdu->pdu_type){
903             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
904             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
905             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
906                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
907                 if (upper_pdu->lower_pdu == pdu_to_find){
908                     btstack_linked_list_iterator_remove(&it);
909                     return upper_pdu;
910                 }
911                 break;
912             default:
913                 break;
914         }
915     }
916     return NULL;
917 }
918 
919 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
920     mesh_upper_transport_pdu_t * upper_pdu;
921     mesh_network_pdu_t * network_pdu;
922     mesh_segmented_pdu_t * segmented_pdu;
923     switch (callback_type){
924         case MESH_TRANSPORT_PDU_RECEIVED:
925             mesh_upper_transport_message_received(pdu);
926             break;
927         case MESH_TRANSPORT_PDU_SENT:
928             switch (pdu->pdu_type){
929                 case MESH_PDU_TYPE_SEGMENTED:
930                     // try to find in outgoing active
931                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
932                     btstack_assert(upper_pdu != NULL);
933                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
934                     // free chunks
935                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
936                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
937                         mesh_network_pdu_free(network_pdu);
938                     }
939                     // free segmented pdu
940                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
941                     // TODO: free segmented_pdu
942                     upper_pdu->lower_pdu = NULL;
943                     switch (upper_pdu->pdu_header.pdu_type){
944                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
945                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
946                             break;
947                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
948                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
949                             break;
950                         default:
951                             btstack_assert(false);
952                             break;
953                     }
954                     break;
955                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
956                     // find corresponding upper transport pdu and free single segment
957                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
958                     btstack_assert(upper_pdu != NULL);
959                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
960                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
961                     upper_pdu->lower_pdu = NULL;
962                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
963                     break;
964                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
965                     mesh_access_message_handler(callback_type, status, pdu);
966                     break;
967                 default:
968                     btstack_assert(false);
969                     break;
970             }
971             mesh_upper_transport_run();
972             break;
973         default:
974             break;
975     }
976 }
977 
978 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
979     mesh_network_pdu_t   * network_pdu;
980     mesh_segmented_pdu_t   * message_pdu;
981     switch (pdu->pdu_type) {
982         case MESH_PDU_TYPE_NETWORK:
983             network_pdu = (mesh_network_pdu_t *) pdu;
984             mesh_network_pdu_free(network_pdu);
985             break;
986         case MESH_PDU_TYPE_SEGMENTED:
987             message_pdu = (mesh_segmented_pdu_t *) pdu;
988             mesh_message_pdu_free(message_pdu);
989         default:
990             btstack_assert(false);
991             break;
992     }
993 }
994 
995 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
996     crypto_active = 0;
997     switch (pdu->pdu_type){
998         case MESH_PDU_TYPE_ACCESS:
999             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1000         case MESH_PDU_TYPE_CONTROL:
1001             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1002             break;
1003         default:
1004             btstack_assert(0);
1005             break;
1006     }
1007 }
1008 
1009 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1010     switch (pdu->pdu_type){
1011         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1012         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1013             break;
1014         default:
1015             btstack_assert(false);
1016             break;
1017     }
1018 
1019     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1020 
1021     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1022     mesh_upper_transport_run();
1023 }
1024 
1025 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1026     switch (pdu->pdu_type){
1027         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1028             break;
1029         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1030             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1031             break;
1032         default:
1033             btstack_assert(false);
1034             break;
1035     }
1036 
1037     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1038     mesh_upper_transport_run();
1039 }
1040 
1041 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,
1042                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1043 
1044     if (control_pdu_len > 11) return 1;
1045 
1046     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1047     if (!network_key) return 1;
1048 
1049     uint8_t transport_pdu_data[12];
1050     transport_pdu_data[0] = opcode;
1051     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1052     uint16_t transport_pdu_len = control_pdu_len + 1;
1053 
1054     // setup network_pdu
1055     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1056 
1057     return 0;
1058 }
1059 
1060 static uint8_t mesh_upper_transport_setup_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
1061                                                                 const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1062 
1063     if (control_pdu_len > 256) return 1;
1064 
1065     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1066     if (!network_key) return 1;
1067 
1068     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1069     upper_pdu->ctl_ttl = ttl;
1070     upper_pdu->src = src;
1071     upper_pdu->dst = dest;
1072     upper_pdu->transmic_len = 0;    // no TransMIC for control
1073     upper_pdu->netkey_index = netkey_index;
1074     upper_pdu->akf_aid_control = opcode;
1075 
1076     // allocate segments
1077     btstack_linked_list_t free_segments = NULL;
1078     bool ok = mesh_segmented_allocate_segments( &free_segments, control_pdu_len);
1079     if (!ok) return 1;
1080     // store control pdu
1081     mesh_segmented_store_payload(control_pdu_data, control_pdu_len, &free_segments, &upper_pdu->segments);
1082     upper_pdu->len = control_pdu_len;
1083     return 0;
1084 }
1085 
1086 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
1087                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1088     switch (pdu->pdu_type){
1089         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1090             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);
1091         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1092             return mesh_upper_transport_setup_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu,  netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
1093         default:
1094             btstack_assert(0);
1095             return 1;
1096     }
1097 }
1098 
1099 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_access_pdu_t * access_pdu, uint16_t netkey_index,
1100                                                                       uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1101 
1102     // get app or device key
1103     const mesh_transport_key_t *appkey;
1104     appkey = mesh_transport_key_get(appkey_index);
1105     if (appkey == NULL) {
1106         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1107         return 1;
1108     }
1109     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1110 
1111     // lookup network by netkey_index
1112     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1113     if (!network_key) return 1;
1114     if (network_key == NULL) {
1115         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1116         return 1;
1117     }
1118 
1119     const uint8_t trans_mic_len = szmic ? 8 : 4;
1120 
1121     // store in transport pdu
1122     access_pdu->transmic_len = trans_mic_len;
1123     access_pdu->netkey_index = netkey_index;
1124     access_pdu->appkey_index = appkey_index;
1125     access_pdu->akf_aid_control = akf_aid;
1126     mesh_access_set_nid_ivi(access_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
1127     mesh_access_set_src(access_pdu, src);
1128     mesh_access_set_dest(access_pdu, dest);
1129     mesh_access_set_ctl_ttl(access_pdu, ttl);
1130     return 0;
1131 }
1132 
1133 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1134                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1135 
1136     // get app or device key
1137     const mesh_transport_key_t *appkey;
1138     appkey = mesh_transport_key_get(appkey_index);
1139     if (appkey == NULL) {
1140         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1141         return 1;
1142     }
1143     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1144 
1145     // lookup network by netkey_index
1146     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1147     if (!network_key) return 1;
1148     if (network_key == NULL) {
1149         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1150         return 1;
1151     }
1152 
1153     const uint8_t trans_mic_len = szmic ? 8 : 4;
1154 
1155     // store in transport pdu
1156     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1157     upper_pdu->ctl_ttl = ttl;
1158     upper_pdu->src = src;
1159     upper_pdu->dst = dest;
1160     upper_pdu->transmic_len = trans_mic_len;
1161     upper_pdu->netkey_index = netkey_index;
1162     upper_pdu->appkey_index = appkey_index;
1163     upper_pdu->akf_aid_control = akf_aid;
1164     return 0;
1165 }
1166 
1167 static uint8_t mesh_upper_transport_setup_upper_access_pdu(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
1168                                                            uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1169     int status = mesh_upper_transport_setup_upper_access_pdu_header(upper_pdu, netkey_index, appkey_index, ttl, src,
1170                                                                     dest, szmic);
1171     if (status) return status;
1172 
1173     // allocate segments
1174     btstack_linked_list_t free_segments = NULL;
1175     bool ok = mesh_segmented_allocate_segments( &free_segments, access_pdu_len);
1176     if (!ok) return 1;
1177     // store control pdu
1178     mesh_segmented_store_payload(access_pdu_data, access_pdu_len, &free_segments, &upper_pdu->segments);
1179     upper_pdu->len = access_pdu_len;
1180     return 0;
1181 }
1182 
1183 
1184 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1185                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1186     switch (pdu->pdu_type){
1187         case MESH_PDU_TYPE_ACCESS:
1188             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_access_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
1189         default:
1190             btstack_assert(false);
1191             return 1;
1192     }
1193 }
1194 
1195 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1196                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
1197                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1198     switch (pdu->pdu_type){
1199         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1200         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1201             return mesh_upper_transport_setup_upper_access_pdu((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1202                                                                appkey_index, ttl, src, dest, szmic, access_pdu_data,
1203                                                                access_pdu_len);
1204         default:
1205             btstack_assert(false);
1206             return 1;
1207     }
1208 }
1209 
1210 void mesh_upper_transport_register_access_message_handler(void (*callback)(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu)) {
1211     mesh_access_message_handler = callback;
1212 }
1213 
1214 void mesh_upper_transport_register_control_message_handler(void (*callback)(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu)){
1215     mesh_control_message_handler = callback;
1216 }
1217 
1218 void mesh_upper_transport_init(){
1219     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1220 }
1221