xref: /btstack/src/mesh/mesh_upper_transport.c (revision 274c04d6a254a935afdd1b74048c2248611abe5a)
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_access_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 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
87 
88 // incoming segmented (mesh_segmented_pdu_t) or unsegmented (network_pdu_t)
89 static mesh_pdu_t *          incoming_access_encrypted;
90 
91 // multi-purpose union: segmented control reassembly, decrypted access pdu
92 static union {
93     mesh_control_pdu_t    control;
94     mesh_access_pdu_t     access;
95 } incoming_pdu_singleton;
96 
97 // pointer to incoming_pdu_singleton.access
98 static mesh_access_pdu_t *   incoming_access_decrypted;
99 
100 // pointer to incoming_pdu_singleton.access
101 static mesh_control_pdu_t *  incoming_control_pdu;
102 
103 // incoming unsegmented (network) and segmented (transport) control and access messages
104 static btstack_linked_list_t upper_transport_incoming;
105 
106 // outgoing unsegmented and segmented control and access messages
107 static btstack_linked_list_t upper_transport_outgoing;
108 
109 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
110 static btstack_linked_list_t upper_transport_outgoing_active;
111 
112 // TODO: higher layer define used for assert
113 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
114 
115 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
116     printf("%-20s ", name);
117     printf_hexdump(data, len);
118 }
119 // static void mesh_print_x(const char * name, uint32_t value){
120 //     printf("%20s: 0x%x", name, (int) value);
121 // }
122 
123 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
124                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
125                                                                  uint8_t aid) {
126     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
127     // config
128     it->dst   = dst;
129     // init elements
130     it->key     = NULL;
131     it->address = NULL;
132     // init element iterators
133     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
134     // init address iterator
135     if (mesh_network_address_virtual(it->dst)){
136         mesh_virtual_address_iterator_init(&it->address_it, dst);
137         // get first key
138         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
139             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
140         }
141     }
142 }
143 
144 // cartesian product: keys x addressses
145 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
146     if (mesh_network_address_virtual(it->dst)) {
147         // find next valid entry
148         while (true){
149             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
150             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
151             // get next key
152             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
153             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
154         }
155     } else {
156         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
157     }
158 }
159 
160 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
161     if (mesh_network_address_virtual(it->dst)) {
162         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
163     } else {
164         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
165     }
166 }
167 
168 // UPPER TRANSPORT
169 
170 uint16_t mesh_access_dst(mesh_access_pdu_t * access_pdu){
171     return big_endian_read_16(access_pdu->network_header, 7);
172 }
173 
174 uint16_t mesh_access_ctl(mesh_access_pdu_t * access_pdu){
175     return access_pdu->network_header[1] >> 7;
176 }
177 
178 uint32_t mesh_access_seq(mesh_access_pdu_t * access_pdu){
179     return big_endian_read_24(access_pdu->network_header, 2);
180 }
181 
182 void mesh_access_set_nid_ivi(mesh_access_pdu_t * access_pdu, uint8_t nid_ivi){
183     access_pdu->network_header[0] = nid_ivi;
184 }
185 void mesh_access_set_ctl_ttl(mesh_access_pdu_t * access_pdu, uint8_t ctl_ttl){
186     access_pdu->network_header[1] = ctl_ttl;
187 }
188 void mesh_access_set_seq(mesh_access_pdu_t * access_pdu, uint32_t seq){
189     big_endian_store_24(access_pdu->network_header, 2, seq);
190 }
191 void mesh_access_set_src(mesh_access_pdu_t * access_pdu, uint16_t src){
192     big_endian_store_16(access_pdu->network_header, 5, src);
193 }
194 void mesh_access_set_dest(mesh_access_pdu_t * access_pdu, uint16_t dest){
195     big_endian_store_16(access_pdu->network_header, 7, dest);
196 }
197 
198 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
199     // assemble payload
200     btstack_linked_list_iterator_t it;
201     btstack_linked_list_iterator_init(&it, segments);
202     while (btstack_linked_list_iterator_has_next(&it)) {
203         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
204         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
205         // get segment n
206         uint8_t *lower_transport_pdu = mesh_network_pdu_data(segment);
207         uint8_t seg_o = (big_endian_read_16(lower_transport_pdu, 2) >> 5) & 0x001f;
208         uint8_t *segment_data = &lower_transport_pdu[4];
209         (void) memcpy(&buffer[seg_o * segment_len], segment_data, segment_len);
210     }
211 }
212 
213 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
214     // assemble payload
215     btstack_linked_list_iterator_t it;
216     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
217     uint16_t offset = 0;
218     while (btstack_linked_list_iterator_has_next(&it)) {
219         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
220         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
221         btstack_assert((offset + segment->len) <= buffer_len);
222         (void) memcpy(&buffer[offset], segment->data, segment->len);
223         offset += segment->len;
224     }
225     return offset;
226 }
227 
228 // store payload in provided list of network pdus
229 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){
230     uint16_t payload_offset = 0;
231     uint16_t bytes_current_segment = 0;
232     mesh_network_pdu_t * network_pdu = NULL;
233     while (payload_offset < payload_len){
234         if (bytes_current_segment == 0){
235             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
236             btstack_assert(network_pdu != NULL);
237             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
238             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
239         }
240         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
241         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
242         bytes_current_segment -= bytes_to_copy;
243         network_pdu->len += bytes_to_copy;
244         payload_offset += bytes_to_copy;
245     }
246 }
247 
248 // tries allocate and add enough segments to store payload of given size
249 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
250     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
251     while (storage_size < payload_len){
252         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
253         if (network_pdu == NULL) break;
254         storage_size += MESH_NETWORK_PAYLOAD_MAX;
255         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
256     }
257     return (storage_size >= payload_len);
258 }
259 
260 // stub lower transport
261 
262 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
263     printf("List: %s:\n", name);
264     btstack_linked_list_iterator_t it;
265     btstack_linked_list_iterator_init(&it, list);
266     while (btstack_linked_list_iterator_has_next(&it)){
267         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
268         printf("- %p\n", pdu);
269         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
270     }
271 }
272 
273 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
274     while (!btstack_linked_list_empty(list)){
275         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
276     }
277 }
278 
279 void mesh_upper_transport_dump(void){
280     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
281 }
282 
283 void mesh_upper_transport_reset(void){
284     crypto_active = 0;
285     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
286 }
287 
288 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
289     // Device Key is fixed
290     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
291         return mesh_transport_key_get(appkey_index);
292     }
293 
294     // Get key refresh state from subnet
295     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
296     if (subnet == NULL) return NULL;
297 
298     // identify old and new app keys for given appkey_index
299     mesh_transport_key_t * old_key = NULL;
300     mesh_transport_key_t * new_key = NULL;
301     mesh_transport_key_iterator_t it;
302     mesh_transport_key_iterator_init(&it, netkey_index);
303     while (mesh_transport_key_iterator_has_more(&it)){
304         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
305         if (transport_key->appkey_index != appkey_index) continue;
306         if (transport_key->old_key == 0) {
307             new_key = transport_key;
308         } else {
309             old_key = transport_key;
310         }
311     }
312 
313     // if no key is marked as old, just use the current one
314     if (old_key == NULL) return new_key;
315 
316     // use new key if it exists in phase two
317     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
318         return new_key;
319     } else {
320         return old_key;
321     }
322 }
323 
324 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
325     // get IV Index and IVI
326     uint32_t iv_index = mesh_get_iv_index();
327     int ivi = ivi_nid >> 7;
328 
329     // if least significant bit differs, use previous IV Index
330     if ((iv_index & 1 ) ^ ivi){
331         iv_index--;
332     }
333     return iv_index;
334 }
335 
336 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
337     mesh_access_pdu_t * access_pdu;
338     mesh_upper_transport_pdu_t * upper_pdu;
339     switch (pdu->pdu_type){
340         case MESH_PDU_TYPE_ACCESS:
341             access_pdu = (mesh_access_pdu_t *) pdu;
342             nonce[1] = access_pdu->transmic_len == 8 ? 0x80 : 0x00;
343             (void)memcpy(&nonce[2], &access_pdu->network_header[2], 7);
344             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->network_header[0]));
345             break;
346         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
347         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
348             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
349             nonce[1] = upper_pdu->transmic_len == 8 ? 0x80 : 0x00;
350             // 'network header'
351             big_endian_store_24(nonce, 2, upper_pdu->seq);
352             big_endian_store_16(nonce, 5, upper_pdu->src);
353             big_endian_store_16(nonce, 7, upper_pdu->dst);
354             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
355             break;
356         default:
357             btstack_assert(0);
358             break;
359     }
360 }
361 
362 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
363     nonce[0] = 0x01;
364     transport_segmented_setup_nonce(nonce, pdu);
365     mesh_print_hex("AppNonce", nonce, 13);
366 }
367 
368 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
369     nonce[0] = 0x02;
370     transport_segmented_setup_nonce(nonce, pdu);
371     mesh_print_hex("DeviceNonce", nonce, 13);
372 }
373 
374 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
375     crypto_active = 0;
376     btstack_assert(mesh_access_ctl(access_pdu) == 0);
377     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
378     incoming_access_encrypted = NULL;
379     incoming_access_decrypted = NULL;
380     mesh_upper_transport_run();
381 }
382 
383 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
384     crypto_active = 0;
385     incoming_control_pdu = NULL;
386     mesh_upper_transport_run();
387 }
388 
389 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
390     UNUSED(arg);
391 
392     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
393     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
394 
395     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
396 
397     // store TransMIC
398     uint8_t trans_mic[8];
399     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
400     mesh_print_hex("TransMIC", trans_mic, incoming_access_decrypted->transmic_len);
401 
402     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], incoming_access_decrypted->transmic_len) == 0){
403         printf("TransMIC matches\n");
404 
405         // remove TransMIC from payload
406         incoming_access_decrypted->len -= incoming_access_decrypted->transmic_len;
407 
408         // if virtual address, update dst to pseudo_dst
409         if (mesh_network_address_virtual(mesh_access_dst(incoming_access_decrypted))){
410             big_endian_store_16(incoming_access_decrypted->network_header, 7, mesh_transport_key_it.address->pseudo_dst);
411         }
412 
413         // pass to upper layer
414         btstack_assert(mesh_access_message_handler != NULL);
415         mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_access_decrypted;
416         mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
417 
418         printf("\n");
419 
420     } else {
421         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
422         if (akf){
423             printf("TransMIC does not match, try next key\n");
424             mesh_upper_transport_validate_access_message();
425         } else {
426             printf("TransMIC does not match device key, done\n");
427             // done
428             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
429         }
430     }
431 }
432 
433 static void mesh_upper_transport_validate_access_message_digest(void * arg){
434     UNUSED(arg);
435     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
436     uint8_t * upper_transport_pdu_data_in  = incoming_access_decrypted->data;
437     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
438 
439     mesh_network_pdu_t * unsegmented_pdu = NULL;
440     mesh_segmented_pdu_t * segmented_pdu = NULL;
441     switch (incoming_access_encrypted->pdu_type){
442         case MESH_PDU_TYPE_SEGMENTED:
443             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
444             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
445             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
446                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
447             break;
448         case MESH_PDU_TYPE_UNSEGMENTED:
449             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
450             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
451             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
452                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
453             break;
454         default:
455             btstack_assert(false);
456             break;
457     }
458 
459 }
460 
461 static void mesh_upper_transport_validate_access_message(void){
462     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
463     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
464 
465     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
466         printf("No valid transport key found\n");
467         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
468         return;
469     }
470     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
471     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
472 
473     if (message_key->akf){
474         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
475     } else {
476         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
477     }
478 
479     // store application / device key index
480     mesh_print_hex("AppOrDevKey", message_key->key, 16);
481     incoming_access_decrypted->appkey_index = message_key->appkey_index;
482 
483     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
484 
485     // decrypt ccm
486     crypto_active = 1;
487     uint16_t aad_len  = 0;
488     if (mesh_network_address_virtual(mesh_access_dst(incoming_access_decrypted))){
489         aad_len  = 16;
490     }
491     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, incoming_access_decrypted->transmic_len);
492 
493     if (aad_len){
494         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
495                                   &mesh_upper_transport_validate_access_message_digest, NULL);
496     } else {
497         mesh_upper_transport_validate_access_message_digest(NULL);
498     }
499 }
500 
501 static void mesh_upper_transport_process_access_message(void){
502     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
503     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
504     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
505 
506     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
507     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
508 
509     printf("AKF: %u\n",   akf);
510     printf("AID: %02x\n", aid);
511 
512     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_access_dst(incoming_access_decrypted),
513                                                          incoming_access_decrypted->netkey_index, akf, aid);
514     mesh_upper_transport_validate_access_message();
515 }
516 
517 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
518     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
519     mesh_upper_transport_run();
520 }
521 
522 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
523 
524     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
525     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
526 
527     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
528     btstack_linked_list_t free_segments = segmented_pdu->segments;
529     segmented_pdu->segments = NULL;
530     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
531 
532     // copy meta
533     segmented_pdu->len = upper_pdu->len;
534     segmented_pdu->netkey_index = upper_pdu->netkey_index;
535     segmented_pdu->transmic_len = upper_pdu->transmic_len;
536     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
537     segmented_pdu->flags = upper_pdu->flags;
538 
539     // setup segmented_pdu header
540     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
541     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
542     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
543     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
544     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
545     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
546     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
547 
548     // queue up
549     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
550     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
551 
552     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
553 }
554 
555 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
556 
557     // provide segment
558     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
559 
560     // setup network pdu
561     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
562     network_pdu->data[0] = upper_pdu->ivi_nid;
563     network_pdu->data[1] = upper_pdu->ctl_ttl;
564     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
565     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
566     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
567     network_pdu->netkey_index = upper_pdu->netkey_index;
568 
569     // setup access message
570     network_pdu->data[9] = upper_pdu->akf_aid_control;
571     btstack_assert(upper_pdu->len < 15);
572     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
573     network_pdu->len = 10 + upper_pdu->len;
574     network_pdu->flags = 0;
575 
576     // queue up
577     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
578 
579     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
580 }
581 
582 static void mesh_upper_transport_send_access_ccm(void * arg){
583     crypto_active = 0;
584 
585     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
586     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
587     // store TransMIC
588     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
589     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], upper_pdu->transmic_len);
590     upper_pdu->len += upper_pdu->transmic_len;
591     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
592     switch (upper_pdu->pdu_header.pdu_type){
593         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
594             mesh_upper_transport_send_access_unsegmented(upper_pdu);
595             break;
596         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
597             mesh_upper_transport_send_access_segmented(upper_pdu);
598             break;
599         default:
600             btstack_assert(false);
601     }
602 }
603 
604 static void mesh_upper_transport_send_access_digest(void *arg){
605     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
606     uint16_t  access_pdu_len  = upper_pdu->len;
607     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
608                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
609 }
610 
611 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
612 
613     // if dst is virtual address, lookup label uuid and hash
614     uint16_t aad_len = 0;
615     mesh_virtual_address_t * virtual_address = NULL;
616     if (mesh_network_address_virtual(upper_pdu->dst)){
617         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
618         if (!virtual_address){
619             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
620             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
621             return;
622         }
623         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
624         // printf_hexdump(virtual_address->label_uuid, 16);
625         aad_len = 16;
626         upper_pdu->dst = virtual_address->hash;
627     }
628 
629     // get app or device key
630     uint16_t appkey_index = upper_pdu->appkey_index;
631     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
632     if (appkey == NULL){
633         printf("AppKey %04x not found, drop message\n", appkey_index);
634         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
635         return;
636     }
637 
638     // reserve slot
639     mesh_lower_transport_reserve_slot();
640 
641     // reserve one sequence number, which is also used to encrypt access payload
642     uint32_t seq = mesh_sequence_number_next();
643     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
644     upper_pdu->seq = seq;
645 
646     // also reserves crypto_buffer
647     crypto_active = 1;
648 
649     // flatten segmented pdu into crypto buffer
650     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
651     btstack_assert(payload_len == upper_pdu->len);
652 
653     // Dump PDU
654     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
655     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
656 
657     // setup nonce - uses dst, so after pseudo address translation
658     if (appkey_index == MESH_DEVICE_KEY_INDEX){
659         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
660     } else {
661         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
662     }
663 
664     // Dump key
665     mesh_print_hex("AppOrDevKey", appkey->key, 16);
666 
667     // encrypt ccm
668     uint8_t   transmic_len    = upper_pdu->transmic_len;
669     uint16_t  access_pdu_len  = upper_pdu->len;
670     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
671     if (virtual_address){
672         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
673         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
674                                   &mesh_upper_transport_send_access_digest, upper_pdu);
675     } else {
676         mesh_upper_transport_send_access_digest(upper_pdu);
677     }
678 }
679 
680 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
681     // reserve slot
682     mesh_lower_transport_reserve_slot();
683     // reserve sequence number
684     uint32_t seq = mesh_sequence_number_next();
685     mesh_network_pdu_set_seq(network_pdu, seq);
686     // Dump PDU
687     uint8_t opcode = network_pdu->data[9];
688     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
689     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
690 
691     // send
692      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
693 }
694 
695 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
696     // reserve slot
697     mesh_lower_transport_reserve_slot();
698     // reserve sequence number
699     uint32_t seq = mesh_sequence_number_next();
700     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
701     upper_pdu->seq = seq;
702     // Dump PDU
703     // uint8_t opcode = upper_pdu->data[0];
704     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
705     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
706     // send
707     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
708     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
709 
710     // lend segments to lower transport pdu
711     segmented_pdu->segments = upper_pdu->segments;
712     upper_pdu->segments = NULL;
713 
714     // copy meta
715     segmented_pdu->len = upper_pdu->len;
716     segmented_pdu->netkey_index = upper_pdu->netkey_index;
717     segmented_pdu->transmic_len = 0;   // no TransMIC for control
718     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
719     segmented_pdu->flags = upper_pdu->flags;
720 
721     // setup segmented_pdu header
722     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
723     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
724     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
725     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
726     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
727     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
728 
729     // queue up
730     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
731     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
732 
733     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
734 }
735 
736 static void mesh_upper_transport_run(void){
737 
738     while(!btstack_linked_list_empty(&upper_transport_incoming)){
739 
740         if (crypto_active) return;
741 
742         // get next message
743         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
744         mesh_network_pdu_t   * network_pdu;
745         mesh_segmented_pdu_t   * message_pdu;
746         switch (pdu->pdu_type){
747             case MESH_PDU_TYPE_UNSEGMENTED:
748                 network_pdu = (mesh_network_pdu_t *) pdu;
749                 // control?
750                 if (mesh_network_control(network_pdu)) {
751 
752                     incoming_control_pdu =  &incoming_pdu_singleton.control;
753                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
754                     incoming_control_pdu->len =  network_pdu->len;
755                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
756 
757                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
758 
759                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
760                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
761                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
762 
763                     // copy meta data into encrypted pdu buffer
764                     (void)memcpy(incoming_control_pdu->network_header, network_pdu->data, 9);
765 
766                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
767 
768                     // free mesh message
769                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
770 
771                     btstack_assert(mesh_control_message_handler != NULL);
772                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
773                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
774 
775                 } else {
776 
777                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
778 
779                     incoming_access_decrypted = &incoming_pdu_singleton.access;
780                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
781                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
782                     incoming_access_decrypted->transmic_len = 4;
783                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
784                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
785                     (void)memcpy(incoming_access_decrypted->network_header, network_pdu->data, 9);
786 
787                     mesh_upper_transport_process_access_message();
788                 }
789                 break;
790             case MESH_PDU_TYPE_SEGMENTED:
791                 message_pdu = (mesh_segmented_pdu_t *) pdu;
792                 uint8_t ctl = mesh_message_ctl(message_pdu);
793                 if (ctl){
794                     incoming_control_pdu=  &incoming_pdu_singleton.control;
795                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
796 
797                     // flatten
798                     mesh_segmented_pdu_flatten(&message_pdu->segments, 8, incoming_control_pdu->data);
799 
800                     // copy meta data into encrypted pdu buffer
801                     incoming_control_pdu->len =  message_pdu->len;
802                     incoming_access_decrypted->netkey_index =  message_pdu->netkey_index;
803                     incoming_control_pdu->akf_aid_control =  message_pdu->akf_aid_control;
804                     incoming_control_pdu->flags = 0;
805                     (void)memcpy(incoming_control_pdu->network_header, message_pdu->network_header, 9);
806 
807                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
808 
809                     // free mesh message
810                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
811 
812                     btstack_assert(mesh_control_message_handler != NULL);
813                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
814                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
815 
816                 } else {
817 
818                     incoming_access_encrypted = (mesh_pdu_t *) message_pdu;
819 
820                     incoming_access_decrypted = &incoming_pdu_singleton.access;
821                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
822                     incoming_access_decrypted->len =  message_pdu->len;
823                     incoming_access_decrypted->netkey_index =  message_pdu->netkey_index;
824                     incoming_access_decrypted->transmic_len =  message_pdu->transmic_len;
825                     incoming_access_decrypted->akf_aid_control =  message_pdu->akf_aid_control;
826                     (void)memcpy(incoming_access_decrypted->network_header, message_pdu->network_header, 9);
827 
828                     mesh_upper_transport_process_access_message();
829                 }
830                 break;
831             default:
832                 btstack_assert(0);
833                 break;
834         }
835     }
836 
837     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
838 
839         if (crypto_active) break;
840 
841         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
842         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
843 
844         mesh_upper_transport_pdu_t * upper_pdu;
845         mesh_segmented_pdu_t * segmented_pdu;
846         bool ok;
847 
848         switch (pdu->pdu_type){
849             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
850                 // control pdus can go through directly
851                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
852                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
853                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
854                 break;
855             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
856                 // control pdus can go through directly
857                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
858                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
859                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
860                 break;
861             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
862                 // segmented access pdus required a mesh-segmented-pdu
863                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
864                 if (upper_pdu->lower_pdu == NULL){
865                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
866                 }
867                 if (segmented_pdu == NULL) break;
868                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
869                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
870                 // and a mesh-network-pdu for each segment in upper pdu
871                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + upper_pdu->transmic_len);
872                 if (!ok) break;
873                 // all buffers available, get started
874                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
875                 mesh_upper_transport_send_access(upper_pdu);
876                 break;
877             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
878                 // unsegmented access pdus require a single mesh-network-dpu
879                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
880                 if (upper_pdu->lower_pdu == NULL){
881                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
882                 }
883                 if (upper_pdu->lower_pdu == NULL) break;
884                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
885                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
886                 break;
887             default:
888                 btstack_assert(false);
889                 break;
890         }
891     }
892 }
893 
894 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
895     btstack_linked_list_iterator_t it;
896     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
897     mesh_upper_transport_pdu_t * upper_pdu;
898     while (btstack_linked_list_iterator_has_next(&it)){
899         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
900         switch (mesh_pdu->pdu_type){
901             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
902             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
903             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
904                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
905                 if (upper_pdu->lower_pdu == pdu_to_find){
906                     btstack_linked_list_iterator_remove(&it);
907                     return upper_pdu;
908                 }
909                 break;
910             default:
911                 break;
912         }
913     }
914     return NULL;
915 }
916 
917 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
918     mesh_upper_transport_pdu_t * upper_pdu;
919     mesh_network_pdu_t * network_pdu;
920     mesh_segmented_pdu_t * segmented_pdu;
921     switch (callback_type){
922         case MESH_TRANSPORT_PDU_RECEIVED:
923             mesh_upper_transport_message_received(pdu);
924             break;
925         case MESH_TRANSPORT_PDU_SENT:
926             switch (pdu->pdu_type){
927                 case MESH_PDU_TYPE_SEGMENTED:
928                     // try to find in outgoing active
929                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
930                     btstack_assert(upper_pdu != NULL);
931                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
932                     // free chunks
933                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
934                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
935                         mesh_network_pdu_free(network_pdu);
936                     }
937                     // free segmented pdu
938                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
939                     // TODO: free segmented_pdu
940                     upper_pdu->lower_pdu = NULL;
941                     switch (upper_pdu->pdu_header.pdu_type){
942                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
943                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
944                             break;
945                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
946                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
947                             break;
948                         default:
949                             btstack_assert(false);
950                             break;
951                     }
952                     break;
953                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
954                     // find corresponding upper transport pdu and free single segment
955                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
956                     btstack_assert(upper_pdu != NULL);
957                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
958                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
959                     upper_pdu->lower_pdu = NULL;
960                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
961                     break;
962                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
963                     mesh_access_message_handler(callback_type, status, pdu);
964                     break;
965                 default:
966                     btstack_assert(false);
967                     break;
968             }
969             mesh_upper_transport_run();
970             break;
971         default:
972             break;
973     }
974 }
975 
976 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
977     mesh_network_pdu_t   * network_pdu;
978     mesh_segmented_pdu_t   * message_pdu;
979     switch (pdu->pdu_type) {
980         case MESH_PDU_TYPE_NETWORK:
981             network_pdu = (mesh_network_pdu_t *) pdu;
982             mesh_network_pdu_free(network_pdu);
983             break;
984         case MESH_PDU_TYPE_SEGMENTED:
985             message_pdu = (mesh_segmented_pdu_t *) pdu;
986             mesh_message_pdu_free(message_pdu);
987         default:
988             btstack_assert(false);
989             break;
990     }
991 }
992 
993 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
994     crypto_active = 0;
995     switch (pdu->pdu_type){
996         case MESH_PDU_TYPE_ACCESS:
997             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
998         case MESH_PDU_TYPE_CONTROL:
999             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1000             break;
1001         default:
1002             btstack_assert(0);
1003             break;
1004     }
1005 }
1006 
1007 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1008     switch (pdu->pdu_type){
1009         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1010         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1011             break;
1012         default:
1013             btstack_assert(false);
1014             break;
1015     }
1016 
1017     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1018 
1019     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1020     mesh_upper_transport_run();
1021 }
1022 
1023 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1024     switch (pdu->pdu_type){
1025         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1026             break;
1027         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1028             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1029             break;
1030         default:
1031             btstack_assert(false);
1032             break;
1033     }
1034 
1035     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1036     mesh_upper_transport_run();
1037 }
1038 
1039 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,
1040                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1041 
1042     if (control_pdu_len > 11) return 1;
1043 
1044     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1045     if (!network_key) return 1;
1046 
1047     uint8_t transport_pdu_data[12];
1048     transport_pdu_data[0] = opcode;
1049     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1050     uint16_t transport_pdu_len = control_pdu_len + 1;
1051 
1052     // setup network_pdu
1053     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1054 
1055     return 0;
1056 }
1057 
1058 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,
1059                                                                 const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1060 
1061     if (control_pdu_len > 256) return 1;
1062 
1063     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1064     if (!network_key) return 1;
1065 
1066     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1067     upper_pdu->ctl_ttl = ttl;
1068     upper_pdu->src = src;
1069     upper_pdu->dst = dest;
1070     upper_pdu->transmic_len = 0;    // no TransMIC for control
1071     upper_pdu->netkey_index = netkey_index;
1072     upper_pdu->akf_aid_control = opcode;
1073 
1074     // allocate segments
1075     btstack_linked_list_t free_segments = NULL;
1076     bool ok = mesh_segmented_allocate_segments( &free_segments, control_pdu_len);
1077     if (!ok) return 1;
1078     // store control pdu
1079     mesh_segmented_store_payload(control_pdu_data, control_pdu_len, &free_segments, &upper_pdu->segments);
1080     upper_pdu->len = control_pdu_len;
1081     return 0;
1082 }
1083 
1084 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
1085                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1086     switch (pdu->pdu_type){
1087         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1088             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);
1089         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1090             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);
1091         default:
1092             btstack_assert(0);
1093             return 1;
1094     }
1095 }
1096 
1097 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_access_pdu_t * access_pdu, uint16_t netkey_index,
1098                                                                       uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1099 
1100     // get app or device key
1101     const mesh_transport_key_t *appkey;
1102     appkey = mesh_transport_key_get(appkey_index);
1103     if (appkey == NULL) {
1104         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1105         return 1;
1106     }
1107     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1108 
1109     // lookup network by netkey_index
1110     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1111     if (!network_key) return 1;
1112     if (network_key == NULL) {
1113         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1114         return 1;
1115     }
1116 
1117     const uint8_t trans_mic_len = szmic ? 8 : 4;
1118 
1119     // store in transport pdu
1120     access_pdu->transmic_len = trans_mic_len;
1121     access_pdu->netkey_index = netkey_index;
1122     access_pdu->appkey_index = appkey_index;
1123     access_pdu->akf_aid_control = akf_aid;
1124     mesh_access_set_nid_ivi(access_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
1125     mesh_access_set_src(access_pdu, src);
1126     mesh_access_set_dest(access_pdu, dest);
1127     mesh_access_set_ctl_ttl(access_pdu, ttl);
1128     return 0;
1129 }
1130 
1131 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1132                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1133 
1134     // get app or device key
1135     const mesh_transport_key_t *appkey;
1136     appkey = mesh_transport_key_get(appkey_index);
1137     if (appkey == NULL) {
1138         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1139         return 1;
1140     }
1141     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1142 
1143     // lookup network by netkey_index
1144     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1145     if (!network_key) return 1;
1146     if (network_key == NULL) {
1147         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1148         return 1;
1149     }
1150 
1151     const uint8_t trans_mic_len = szmic ? 8 : 4;
1152 
1153     // store in transport pdu
1154     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1155     upper_pdu->ctl_ttl = ttl;
1156     upper_pdu->src = src;
1157     upper_pdu->dst = dest;
1158     upper_pdu->transmic_len = trans_mic_len;
1159     upper_pdu->netkey_index = netkey_index;
1160     upper_pdu->appkey_index = appkey_index;
1161     upper_pdu->akf_aid_control = akf_aid;
1162     return 0;
1163 }
1164 
1165 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,
1166                                                            uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1167     int status = mesh_upper_transport_setup_upper_access_pdu_header(upper_pdu, netkey_index, appkey_index, ttl, src,
1168                                                                     dest, szmic);
1169     if (status) return status;
1170 
1171     // allocate segments
1172     btstack_linked_list_t free_segments = NULL;
1173     bool ok = mesh_segmented_allocate_segments( &free_segments, access_pdu_len);
1174     if (!ok) return 1;
1175     // store control pdu
1176     mesh_segmented_store_payload(access_pdu_data, access_pdu_len, &free_segments, &upper_pdu->segments);
1177     upper_pdu->len = access_pdu_len;
1178     return 0;
1179 }
1180 
1181 
1182 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1183                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1184     switch (pdu->pdu_type){
1185         case MESH_PDU_TYPE_ACCESS:
1186             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_access_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
1187         default:
1188             btstack_assert(false);
1189             return 1;
1190     }
1191 }
1192 
1193 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1194                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
1195                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1196     switch (pdu->pdu_type){
1197         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1198         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1199             return mesh_upper_transport_setup_upper_access_pdu((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1200                                                                appkey_index, ttl, src, dest, szmic, access_pdu_data,
1201                                                                access_pdu_len);
1202         default:
1203             btstack_assert(false);
1204             return 1;
1205     }
1206 }
1207 
1208 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)) {
1209     mesh_access_message_handler = callback;
1210 }
1211 
1212 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)){
1213     mesh_control_message_handler = callback;
1214 }
1215 
1216 void mesh_upper_transport_init(){
1217     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1218 }
1219