xref: /btstack/src/mesh/mesh_upper_transport.c (revision 8661c58f369daa8ff811bb10b8e1a3e47e37be40)
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 #include <stdarg.h>
39 #include "btstack_tlv.h"
40 #include "mesh/mesh_foundation.h"
41 #include "mesh_upper_transport.h"
42 #include "mesh/mesh.h"
43 #include "mesh/mesh_proxy.h"
44 #include "mesh/mesh_node.h"
45 
46 #define BTSTACK_FILE__ "mesh_upper_transport.c"
47 
48 #include "mesh/mesh_upper_transport.h"
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 
54 #include "btstack_util.h"
55 #include "btstack_memory.h"
56 #include "btstack_debug.h"
57 #include "btstack_bool.h"
58 
59 #include "mesh/beacon.h"
60 #include "mesh/mesh_iv_index_seq_number.h"
61 #include "mesh/mesh_keys.h"
62 #include "mesh/mesh_lower_transport.h"
63 #include "mesh/mesh_peer.h"
64 #include "mesh/mesh_virtual_addresses.h"
65 
66 // TODO: extract mesh_pdu functions into lower transport or network
67 #include "mesh/mesh_access.h"
68 
69 // combined key x address iterator for upper transport decryption
70 
71 typedef struct {
72     // state
73     mesh_transport_key_iterator_t  key_it;
74     mesh_virtual_address_iterator_t address_it;
75     // elements
76     const mesh_transport_key_t *   key;
77     const mesh_virtual_address_t * address;
78     // address - might be virtual
79     uint16_t dst;
80     // key info
81 } mesh_transport_key_and_virtual_address_iterator_t;
82 
83 static void mesh_upper_transport_validate_access_message(void);
84 static void mesh_upper_transport_run(void);
85 
86 // upper transport callbacks - in access layer
87 static void (*mesh_access_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
88 static void (*mesh_control_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
89 
90 //
91 static int crypto_active;
92 static uint8_t application_nonce[13];
93 static btstack_crypto_ccm_t ccm;
94 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
95 
96 // incoming segmented (mesh_segmented_pdu_t) or unsegmented (network_pdu_t)
97 static mesh_pdu_t *          incoming_access_encrypted;
98 
99 // multi-purpose union: segmented control reassembly, decrypted access pdu
100 static union {
101     mesh_control_pdu_t    control;
102     mesh_access_pdu_t     access;
103 } incoming_pdu_singleton;
104 
105 // pointer to incoming_pdu_singleton.access
106 static mesh_access_pdu_t *   incoming_access_decrypted;
107 
108 // pointer to incoming_pdu_singleton.access
109 static mesh_control_pdu_t *  incoming_control_pdu;
110 
111 // incoming unsegmented (network) and segmented (transport) control and access messages
112 static btstack_linked_list_t upper_transport_incoming;
113 
114 // outgoing unsegmented and segmented control and access messages
115 static btstack_linked_list_t upper_transport_outgoing;
116 
117 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
118 static btstack_linked_list_t upper_transport_outgoing_active;
119 
120 // TODO: higher layer define used for assert
121 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
122 
123 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
124     printf("%-20s ", name);
125     printf_hexdump(data, len);
126 }
127 // static void mesh_print_x(const char * name, uint32_t value){
128 //     printf("%20s: 0x%x", name, (int) value);
129 // }
130 
131 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
132                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
133                                                                  uint8_t aid) {
134     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
135     // config
136     it->dst   = dst;
137     // init elements
138     it->key     = NULL;
139     it->address = NULL;
140     // init element iterators
141     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
142     // init address iterator
143     if (mesh_network_address_virtual(it->dst)){
144         mesh_virtual_address_iterator_init(&it->address_it, dst);
145         // get first key
146         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
147             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
148         }
149     }
150 }
151 
152 // cartesian product: keys x addressses
153 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
154     if (mesh_network_address_virtual(it->dst)) {
155         // find next valid entry
156         while (true){
157             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
158             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
159             // get next key
160             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
161             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
162         }
163     } else {
164         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
165     }
166 }
167 
168 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
169     if (mesh_network_address_virtual(it->dst)) {
170         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
171     } else {
172         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
173     }
174 }
175 
176 // UPPER TRANSPORT
177 
178 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
179     // assemble payload
180     btstack_linked_list_iterator_t it;
181     btstack_linked_list_iterator_init(&it, segments);
182     while (btstack_linked_list_iterator_has_next(&it)) {
183         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
184         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
185         uint8_t offset = 0;
186         while (offset < segment->len){
187             uint8_t seg_o = segment->data[offset++];
188             (void) memcpy(&buffer[seg_o * segment_len], &segment->data[offset], segment_len);
189             offset += segment_len;
190         }
191     }
192 }
193 
194 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
195     // assemble payload
196     btstack_linked_list_iterator_t it;
197     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
198     uint16_t offset = 0;
199     while (btstack_linked_list_iterator_has_next(&it)) {
200         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
201         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
202         btstack_assert((offset + segment->len) <= buffer_len);
203         (void) memcpy(&buffer[offset], segment->data, segment->len);
204         offset += segment->len;
205     }
206     return offset;
207 }
208 
209 // store payload in provided list of network pdus
210 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){
211     uint16_t payload_offset = 0;
212     uint16_t bytes_current_segment = 0;
213     mesh_network_pdu_t * network_pdu = NULL;
214     while (payload_offset < payload_len){
215         if (bytes_current_segment == 0){
216             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
217             btstack_assert(network_pdu != NULL);
218             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
219             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
220         }
221         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
222         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
223         bytes_current_segment -= bytes_to_copy;
224         network_pdu->len += bytes_to_copy;
225         payload_offset += bytes_to_copy;
226     }
227 }
228 
229 // tries allocate and add enough segments to store payload of given size
230 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
231     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
232     while (storage_size < payload_len){
233         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
234         if (network_pdu == NULL) break;
235         storage_size += MESH_NETWORK_PAYLOAD_MAX;
236         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
237     }
238     return (storage_size >= payload_len);
239 }
240 
241 // stub lower transport
242 
243 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
244     printf("List: %s:\n", name);
245     btstack_linked_list_iterator_t it;
246     btstack_linked_list_iterator_init(&it, list);
247     while (btstack_linked_list_iterator_has_next(&it)){
248         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
249         printf("- %p\n", pdu);
250         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
251     }
252 }
253 
254 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
255     while (!btstack_linked_list_empty(list)){
256         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
257     }
258 }
259 
260 void mesh_upper_transport_dump(void){
261     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
262 }
263 
264 void mesh_upper_transport_reset(void){
265     crypto_active = 0;
266     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
267 }
268 
269 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
270     // Device Key is fixed
271     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
272         return mesh_transport_key_get(appkey_index);
273     }
274 
275     // Get key refresh state from subnet
276     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
277     if (subnet == NULL) return NULL;
278 
279     // identify old and new app keys for given appkey_index
280     mesh_transport_key_t * old_key = NULL;
281     mesh_transport_key_t * new_key = NULL;
282     mesh_transport_key_iterator_t it;
283     mesh_transport_key_iterator_init(&it, netkey_index);
284     while (mesh_transport_key_iterator_has_more(&it)){
285         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
286         if (transport_key->appkey_index != appkey_index) continue;
287         if (transport_key->old_key == 0) {
288             new_key = transport_key;
289         } else {
290             old_key = transport_key;
291         }
292     }
293 
294     // if no key is marked as old, just use the current one
295     if (old_key == NULL) return new_key;
296 
297     // use new key if it exists in phase two
298     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
299         return new_key;
300     } else {
301         return old_key;
302     }
303 }
304 
305 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
306     // get IV Index and IVI
307     uint32_t iv_index = mesh_get_iv_index();
308     int ivi = ivi_nid >> 7;
309 
310     // if least significant bit differs, use previous IV Index
311     if ((iv_index & 1 ) ^ ivi){
312         iv_index--;
313     }
314     return iv_index;
315 }
316 
317 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
318     mesh_access_pdu_t * access_pdu;
319     mesh_upper_transport_pdu_t * upper_pdu;
320     switch (pdu->pdu_type){
321         case MESH_PDU_TYPE_ACCESS:
322             access_pdu = (mesh_access_pdu_t *) pdu;
323             nonce[1] = ((access_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
324             big_endian_store_24(nonce, 2, access_pdu->seq);
325             big_endian_store_16(nonce, 5, access_pdu->src);
326             big_endian_store_16(nonce, 7, access_pdu->dst);
327             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
328             break;
329         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
330         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
331             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
332             nonce[1] = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
333             // 'network header'
334             big_endian_store_24(nonce, 2, upper_pdu->seq);
335             big_endian_store_16(nonce, 5, upper_pdu->src);
336             big_endian_store_16(nonce, 7, upper_pdu->dst);
337             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
338             break;
339         default:
340             btstack_assert(0);
341             break;
342     }
343 }
344 
345 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
346     nonce[0] = 0x01;
347     transport_segmented_setup_nonce(nonce, pdu);
348     mesh_print_hex("AppNonce", nonce, 13);
349 }
350 
351 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
352     nonce[0] = 0x02;
353     transport_segmented_setup_nonce(nonce, pdu);
354     mesh_print_hex("DeviceNonce", nonce, 13);
355 }
356 
357 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
358     crypto_active = 0;
359     btstack_assert((access_pdu->ctl_ttl & 0x80) == 0);
360     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
361     incoming_access_encrypted = NULL;
362     incoming_access_decrypted = NULL;
363     mesh_upper_transport_run();
364 }
365 
366 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
367     crypto_active = 0;
368     incoming_control_pdu = NULL;
369     mesh_upper_transport_run();
370 }
371 
372 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
373     UNUSED(arg);
374 
375     uint8_t transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
376     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
377     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
378 
379     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
380 
381     // store TransMIC
382     uint8_t trans_mic[8];
383     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
384     mesh_print_hex("TransMIC", trans_mic, transmic_len);
385 
386     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transmic_len) == 0){
387         printf("TransMIC matches\n");
388 
389         // remove TransMIC from payload
390         incoming_access_decrypted->len -= transmic_len;
391 
392         // if virtual address, update dst to pseudo_dst
393         if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
394             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
395         }
396 
397         // pass to upper layer
398         btstack_assert(mesh_access_message_handler != NULL);
399         mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_access_decrypted;
400         mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
401 
402         printf("\n");
403 
404     } else {
405         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
406         if (akf){
407             printf("TransMIC does not match, try next key\n");
408             mesh_upper_transport_validate_access_message();
409         } else {
410             printf("TransMIC does not match device key, done\n");
411             // done
412             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
413         }
414     }
415 }
416 
417 static void mesh_upper_transport_validate_access_message_digest(void * arg){
418     UNUSED(arg);
419     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
420     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - transmic_len;
421     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
422 
423     mesh_network_pdu_t * unsegmented_pdu = NULL;
424     mesh_segmented_pdu_t * segmented_pdu = NULL;
425     switch (incoming_access_encrypted->pdu_type){
426         case MESH_PDU_TYPE_SEGMENTED:
427             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
428             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
429             mesh_print_hex("Encrypted Payload:", upper_transport_pdu_data_out, upper_transport_pdu_len);
430             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
431                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
432             break;
433         case MESH_PDU_TYPE_UNSEGMENTED:
434             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
435             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
436             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
437                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
438             break;
439         default:
440             btstack_assert(false);
441             break;
442     }
443 
444 }
445 
446 static void mesh_upper_transport_validate_access_message(void){
447     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
448     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
449     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - transmic_len;
450 
451     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
452         printf("No valid transport key found\n");
453         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
454         return;
455     }
456     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
457     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
458 
459     if (message_key->akf){
460         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
461     } else {
462         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
463     }
464 
465     // store application / device key index
466     mesh_print_hex("AppOrDevKey", message_key->key, 16);
467     incoming_access_decrypted->appkey_index = message_key->appkey_index;
468 
469     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
470 
471     // decrypt ccm
472     crypto_active = 1;
473     uint16_t aad_len  = 0;
474     if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
475         aad_len  = 16;
476     }
477     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transmic_len);
478 
479     if (aad_len){
480         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
481                                   &mesh_upper_transport_validate_access_message_digest, NULL);
482     } else {
483         mesh_upper_transport_validate_access_message_digest(NULL);
484     }
485 }
486 
487 static void mesh_upper_transport_process_access_message(void){
488     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
489     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
490     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
491     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
492 
493     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
494     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
495 
496     printf("AKF: %u\n",   akf);
497     printf("AID: %02x\n", aid);
498 
499     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, incoming_access_decrypted->dst,
500                                                          incoming_access_decrypted->netkey_index, akf, aid);
501     mesh_upper_transport_validate_access_message();
502 }
503 
504 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
505     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
506     mesh_upper_transport_run();
507 }
508 
509 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
510 
511     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
512     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
513 
514     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
515     btstack_linked_list_t free_segments = segmented_pdu->segments;
516     segmented_pdu->segments = NULL;
517     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
518 
519     // copy meta
520     segmented_pdu->len = upper_pdu->len;
521     segmented_pdu->netkey_index = upper_pdu->netkey_index;
522     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
523     segmented_pdu->flags = upper_pdu->flags;
524 
525     // setup segmented_pdu header
526     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
527     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
528     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
529     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
530     segmented_pdu->seq = upper_pdu->seq;
531     segmented_pdu->src = upper_pdu->src;
532     segmented_pdu->dst = upper_pdu->dst;
533 
534     // queue up
535     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
536     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
537 
538     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
539 }
540 
541 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
542 
543     // provide segment
544     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
545 
546     // setup network pdu
547     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
548     network_pdu->data[0] = upper_pdu->ivi_nid;
549     network_pdu->data[1] = upper_pdu->ctl_ttl;
550     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
551     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
552     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
553     network_pdu->netkey_index = upper_pdu->netkey_index;
554 
555     // setup access message
556     network_pdu->data[9] = upper_pdu->akf_aid_control;
557     btstack_assert(upper_pdu->len < 15);
558     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
559     network_pdu->len = 10 + upper_pdu->len;
560     network_pdu->flags = 0;
561 
562     // queue up
563     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
564 
565     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
566 }
567 
568 static void mesh_upper_transport_send_access_ccm(void * arg){
569     crypto_active = 0;
570 
571     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
572     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
573     // store TransMIC
574     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
575     uint8_t transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
576     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], transmic_len);
577     upper_pdu->len += transmic_len;
578     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
579     switch (upper_pdu->pdu_header.pdu_type){
580         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
581             mesh_upper_transport_send_access_unsegmented(upper_pdu);
582             break;
583         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
584             mesh_upper_transport_send_access_segmented(upper_pdu);
585             break;
586         default:
587             btstack_assert(false);
588     }
589 }
590 
591 static void mesh_upper_transport_send_access_digest(void *arg){
592     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
593     uint16_t  access_pdu_len  = upper_pdu->len;
594     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
595                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
596 }
597 
598 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
599 
600     // if dst is virtual address, lookup label uuid and hash
601     uint16_t aad_len = 0;
602     mesh_virtual_address_t * virtual_address = NULL;
603     if (mesh_network_address_virtual(upper_pdu->dst)){
604         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
605         if (!virtual_address){
606             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
607             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
608             return;
609         }
610         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
611         // printf_hexdump(virtual_address->label_uuid, 16);
612         aad_len = 16;
613         upper_pdu->dst = virtual_address->hash;
614     }
615 
616     // get app or device key
617     uint16_t appkey_index = upper_pdu->appkey_index;
618     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
619     if (appkey == NULL){
620         printf("AppKey %04x not found, drop message\n", appkey_index);
621         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
622         return;
623     }
624 
625     // reserve slot
626     mesh_lower_transport_reserve_slot();
627 
628     // reserve one sequence number, which is also used to encrypt access payload
629     uint32_t seq = mesh_sequence_number_next();
630     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
631     upper_pdu->seq = seq;
632 
633     // also reserves crypto_buffer
634     crypto_active = 1;
635 
636     // flatten segmented pdu into crypto buffer
637     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
638     btstack_assert(payload_len == upper_pdu->len);
639 
640     // Dump PDU
641     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
642     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
643 
644     // setup nonce - uses dst, so after pseudo address translation
645     if (appkey_index == MESH_DEVICE_KEY_INDEX){
646         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
647     } else {
648         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
649     }
650 
651     // Dump key
652     mesh_print_hex("AppOrDevKey", appkey->key, 16);
653 
654     // encrypt ccm
655     uint8_t   transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
656     uint16_t  access_pdu_len  = upper_pdu->len;
657     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
658     if (virtual_address){
659         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
660         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
661                                   &mesh_upper_transport_send_access_digest, upper_pdu);
662     } else {
663         mesh_upper_transport_send_access_digest(upper_pdu);
664     }
665 }
666 
667 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
668     // reserve slot
669     mesh_lower_transport_reserve_slot();
670     // reserve sequence number
671     uint32_t seq = mesh_sequence_number_next();
672     mesh_network_pdu_set_seq(network_pdu, seq);
673     // Dump PDU
674     uint8_t opcode = network_pdu->data[9];
675     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
676     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
677 
678     // send
679      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
680 }
681 
682 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
683     // reserve slot
684     mesh_lower_transport_reserve_slot();
685     // reserve sequence number
686     uint32_t seq = mesh_sequence_number_next();
687     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
688     upper_pdu->seq = seq;
689     // Dump PDU
690     // uint8_t opcode = upper_pdu->data[0];
691     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
692     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
693     // send
694     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
695     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
696 
697     // lend segments to lower transport pdu
698     segmented_pdu->segments = upper_pdu->segments;
699     upper_pdu->segments = NULL;
700 
701     // copy meta
702     segmented_pdu->len = upper_pdu->len;
703     segmented_pdu->netkey_index = upper_pdu->netkey_index;
704     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
705     segmented_pdu->flags = upper_pdu->flags;
706 
707     btstack_assert((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) == 0);
708 
709     // setup segmented_pdu header
710     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
711     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
712     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
713     segmented_pdu->seq = upper_pdu->seq;
714     segmented_pdu->src = upper_pdu->src;
715     segmented_pdu->dst = upper_pdu->dst;
716 
717     // queue up
718     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
719     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
720 
721     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
722 }
723 
724 static void mesh_upper_transport_run(void){
725 
726     while(!btstack_linked_list_empty(&upper_transport_incoming)){
727 
728         if (crypto_active) return;
729 
730         // get next message
731         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
732         mesh_network_pdu_t   * network_pdu;
733         mesh_segmented_pdu_t   * segmented_pdu;
734         switch (pdu->pdu_type){
735             case MESH_PDU_TYPE_UNSEGMENTED:
736                 network_pdu = (mesh_network_pdu_t *) pdu;
737                 // control?
738                 if (mesh_network_control(network_pdu)) {
739 
740                     incoming_control_pdu =  &incoming_pdu_singleton.control;
741                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
742                     incoming_control_pdu->len =  network_pdu->len;
743                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
744 
745                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
746 
747                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
748                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
749                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
750 
751                     // copy meta data into encrypted pdu buffer
752                     incoming_control_pdu->ivi_nid = network_pdu->data[0];
753                     incoming_control_pdu->ctl_ttl = network_pdu->data[1];
754                     incoming_control_pdu->seq = big_endian_read_24(network_pdu->data, 2);
755                     incoming_control_pdu->src = big_endian_read_16(network_pdu->data, 5);
756                     incoming_control_pdu->dst = big_endian_read_16(network_pdu->data, 7);
757 
758                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
759 
760                     // free mesh message
761                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
762 
763                     btstack_assert(mesh_control_message_handler != NULL);
764                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
765                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
766 
767                 } else {
768 
769                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
770 
771                     incoming_access_decrypted = &incoming_pdu_singleton.access;
772                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
773                     incoming_access_decrypted->flags = 0;
774                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
775                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
776                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
777                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
778                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
779                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
780                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
781                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
782 
783                     mesh_upper_transport_process_access_message();
784                 }
785                 break;
786             case MESH_PDU_TYPE_SEGMENTED:
787                 segmented_pdu = (mesh_segmented_pdu_t *) pdu;
788                 uint8_t ctl = segmented_pdu->ctl_ttl >> 7;
789                 if (ctl){
790                     incoming_control_pdu=  &incoming_pdu_singleton.control;
791                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
792 
793                     // flatten
794                     mesh_segmented_pdu_flatten(&segmented_pdu->segments, 8, incoming_control_pdu->data);
795 
796                     // copy meta data into encrypted pdu buffer
797                     incoming_control_pdu->flags = 0;
798                     incoming_control_pdu->len =  segmented_pdu->len;
799                     incoming_control_pdu->netkey_index =  segmented_pdu->netkey_index;
800                     incoming_control_pdu->akf_aid_control = segmented_pdu->akf_aid_control;
801                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
802                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
803                     incoming_access_decrypted->seq = segmented_pdu->seq;
804                     incoming_access_decrypted->src = segmented_pdu->src;
805                     incoming_access_decrypted->dst = segmented_pdu->dst;
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 *)segmented_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 *) segmented_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->flags = segmented_pdu->flags;
823                     incoming_access_decrypted->len =  segmented_pdu->len;
824                     incoming_access_decrypted->netkey_index = segmented_pdu->netkey_index;
825                     incoming_access_decrypted->akf_aid_control =  segmented_pdu->akf_aid_control;
826                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
827                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
828                     incoming_access_decrypted->seq = segmented_pdu->seq;
829                     incoming_access_decrypted->src = segmented_pdu->src;
830                     incoming_access_decrypted->dst = segmented_pdu->dst;
831 
832                     mesh_upper_transport_process_access_message();
833                 }
834                 break;
835             default:
836                 btstack_assert(0);
837                 break;
838         }
839     }
840 
841     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
842 
843         if (crypto_active) break;
844 
845         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
846         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
847 
848         mesh_upper_transport_pdu_t * upper_pdu;
849         mesh_segmented_pdu_t * segmented_pdu;
850         uint8_t transmic_len;
851         bool ok;
852 
853         switch (pdu->pdu_type){
854             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
855                 // control pdus can go through directly
856                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
857                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
858                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
859                 break;
860             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
861                 // control pdus can go through directly
862                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
863                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
864                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
865                 break;
866             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
867                 // segmented access pdus required a mesh-segmented-pdu
868                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
869                 if (upper_pdu->lower_pdu == NULL){
870                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
871                 }
872                 if (segmented_pdu == NULL) break;
873                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
874                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
875                 // and a mesh-network-pdu for each segment in upper pdu
876                 transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
877                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + transmic_len);
878                 if (!ok) break;
879                 // all buffers available, get started
880                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
881                 mesh_upper_transport_send_access(upper_pdu);
882                 break;
883             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
884                 // unsegmented access pdus require a single mesh-network-dpu
885                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
886                 if (upper_pdu->lower_pdu == NULL){
887                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
888                 }
889                 if (upper_pdu->lower_pdu == NULL) break;
890                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
891                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
892                 break;
893             default:
894                 btstack_assert(false);
895                 break;
896         }
897     }
898 }
899 
900 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
901     btstack_linked_list_iterator_t it;
902     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
903     mesh_upper_transport_pdu_t * upper_pdu;
904     while (btstack_linked_list_iterator_has_next(&it)){
905         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
906         switch (mesh_pdu->pdu_type){
907             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
908             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
909             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
910                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
911                 if (upper_pdu->lower_pdu == pdu_to_find){
912                     btstack_linked_list_iterator_remove(&it);
913                     return upper_pdu;
914                 }
915                 break;
916             default:
917                 break;
918         }
919     }
920     return NULL;
921 }
922 
923 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
924     mesh_upper_transport_pdu_t * upper_pdu;
925     mesh_network_pdu_t * network_pdu;
926     mesh_segmented_pdu_t * segmented_pdu;
927     switch (callback_type){
928         case MESH_TRANSPORT_PDU_RECEIVED:
929             mesh_upper_transport_message_received(pdu);
930             break;
931         case MESH_TRANSPORT_PDU_SENT:
932             switch (pdu->pdu_type){
933                 case MESH_PDU_TYPE_SEGMENTED:
934                     // try to find in outgoing active
935                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
936                     btstack_assert(upper_pdu != NULL);
937                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
938                     // free chunks
939                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
940                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
941                         mesh_network_pdu_free(network_pdu);
942                     }
943                     // free segmented pdu
944                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
945                     // TODO: free segmented_pdu
946                     upper_pdu->lower_pdu = NULL;
947                     switch (upper_pdu->pdu_header.pdu_type){
948                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
949                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
950                             break;
951                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
952                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
953                             break;
954                         default:
955                             btstack_assert(false);
956                             break;
957                     }
958                     break;
959                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
960                     // find corresponding upper transport pdu and free single segment
961                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
962                     btstack_assert(upper_pdu != NULL);
963                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
964                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
965                     upper_pdu->lower_pdu = NULL;
966                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
967                     break;
968                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
969                     mesh_access_message_handler(callback_type, status, pdu);
970                     break;
971                 default:
972                     btstack_assert(false);
973                     break;
974             }
975             mesh_upper_transport_run();
976             break;
977         default:
978             break;
979     }
980 }
981 
982 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
983     btstack_assert(pdu != NULL);
984     mesh_network_pdu_t   * network_pdu;
985     mesh_segmented_pdu_t   * message_pdu;
986     mesh_upper_transport_pdu_t * upper_pdu;
987     switch (pdu->pdu_type) {
988         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
989         case MESH_PDU_TYPE_NETWORK:
990             network_pdu = (mesh_network_pdu_t *) pdu;
991             mesh_network_pdu_free(network_pdu);
992             break;
993         case MESH_PDU_TYPE_SEGMENTED:
994             message_pdu = (mesh_segmented_pdu_t *) pdu;
995             mesh_segmented_pdu_free(message_pdu);
996         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
997         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
998         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
999             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1000             while (upper_pdu->segments) {
1001                 mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&upper_pdu->segments);
1002                 mesh_network_pdu_free(segment);
1003             }
1004             btstack_memory_mesh_upper_transport_pdu_free(upper_pdu);
1005             break;
1006         default:
1007             btstack_assert(false);
1008             break;
1009     }
1010 }
1011 
1012 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1013     crypto_active = 0;
1014     switch (pdu->pdu_type){
1015         case MESH_PDU_TYPE_ACCESS:
1016             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1017         case MESH_PDU_TYPE_CONTROL:
1018             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1019             break;
1020         default:
1021             btstack_assert(0);
1022             break;
1023     }
1024 }
1025 
1026 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1027     switch (pdu->pdu_type){
1028         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1029         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1030             break;
1031         default:
1032             btstack_assert(false);
1033             break;
1034     }
1035 
1036     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1037 
1038     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1039     mesh_upper_transport_run();
1040 }
1041 
1042 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1043     switch (pdu->pdu_type){
1044         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1045             break;
1046         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1047             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1048             break;
1049         default:
1050             btstack_assert(false);
1051             break;
1052     }
1053 
1054     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1055     mesh_upper_transport_run();
1056 }
1057 
1058 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,
1059                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1060 
1061     if (control_pdu_len > 11) 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     uint8_t transport_pdu_data[12];
1067     transport_pdu_data[0] = opcode;
1068     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1069     uint16_t transport_pdu_len = control_pdu_len + 1;
1070 
1071     // setup network_pdu
1072     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1073 
1074     return 0;
1075 }
1076 
1077 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,
1078                                                                 const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1079 
1080     if (control_pdu_len > 256) return 1;
1081 
1082     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1083     if (!network_key) return 1;
1084 
1085     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1086     upper_pdu->ctl_ttl = ttl;
1087     upper_pdu->src = src;
1088     upper_pdu->dst = dest;
1089     upper_pdu->netkey_index = netkey_index;
1090     upper_pdu->akf_aid_control = opcode;
1091 
1092     // allocate segments
1093     btstack_linked_list_t free_segments = NULL;
1094     bool ok = mesh_segmented_allocate_segments( &free_segments, control_pdu_len);
1095     if (!ok) return 1;
1096     // store control pdu
1097     mesh_segmented_store_payload(control_pdu_data, control_pdu_len, &free_segments, &upper_pdu->segments);
1098     upper_pdu->len = control_pdu_len;
1099     return 0;
1100 }
1101 
1102 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
1103                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1104     switch (pdu->pdu_type){
1105         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1106             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);
1107         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1108             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);
1109         default:
1110             btstack_assert(0);
1111             return 1;
1112     }
1113 }
1114 
1115 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_access_pdu_t * access_pdu, uint16_t netkey_index,
1116                                                                       uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1117 
1118     // get app or device key
1119     const mesh_transport_key_t *appkey;
1120     appkey = mesh_transport_key_get(appkey_index);
1121     if (appkey == NULL) {
1122         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1123         return 1;
1124     }
1125     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1126 
1127     // lookup network by netkey_index
1128     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1129     if (!network_key) return 1;
1130     if (network_key == NULL) {
1131         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1132         return 1;
1133     }
1134 
1135     const uint8_t trans_mic_len = szmic ? 8 : 4;
1136 
1137     // store in transport pdu
1138     if (szmic){
1139         access_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1140     }
1141     access_pdu->netkey_index = netkey_index;
1142     access_pdu->appkey_index = appkey_index;
1143     access_pdu->akf_aid_control = akf_aid;
1144     uint8_t iviNid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1145     access_pdu->ivi_nid = iviNid;
1146     access_pdu->src = src;
1147     access_pdu->dst = dest;
1148     access_pdu->ctl_ttl = ttl;
1149     return 0;
1150 }
1151 
1152 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1153                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1154 
1155     // get app or device key
1156     const mesh_transport_key_t *appkey;
1157     appkey = mesh_transport_key_get(appkey_index);
1158     if (appkey == NULL) {
1159         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1160         return 1;
1161     }
1162     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1163 
1164     // lookup network by netkey_index
1165     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1166     if (!network_key) return 1;
1167     if (network_key == NULL) {
1168         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1169         return 1;
1170     }
1171 
1172     // store in transport pdu
1173     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1174     upper_pdu->ctl_ttl = ttl;
1175     upper_pdu->src = src;
1176     upper_pdu->dst = dest;
1177     upper_pdu->netkey_index = netkey_index;
1178     upper_pdu->appkey_index = appkey_index;
1179     upper_pdu->akf_aid_control = akf_aid;
1180     if (szmic) {
1181         upper_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1182     }
1183     return 0;
1184 }
1185 
1186 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,
1187                                                            uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1188     int status = mesh_upper_transport_setup_upper_access_pdu_header(upper_pdu, netkey_index, appkey_index, ttl, src,
1189                                                                     dest, szmic);
1190     if (status) return status;
1191 
1192     // allocate segments
1193     btstack_linked_list_t free_segments = NULL;
1194     bool ok = mesh_segmented_allocate_segments( &free_segments, access_pdu_len);
1195     if (!ok) return 1;
1196     // store control pdu
1197     mesh_segmented_store_payload(access_pdu_data, access_pdu_len, &free_segments, &upper_pdu->segments);
1198     upper_pdu->len = access_pdu_len;
1199     return 0;
1200 }
1201 
1202 
1203 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1204                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1205     switch (pdu->pdu_type){
1206         case MESH_PDU_TYPE_ACCESS:
1207             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_access_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
1208         default:
1209             btstack_assert(false);
1210             return 1;
1211     }
1212 }
1213 
1214 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1215                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
1216                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1217     switch (pdu->pdu_type){
1218         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1219         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1220             return mesh_upper_transport_setup_upper_access_pdu((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1221                                                                appkey_index, ttl, src, dest, szmic, access_pdu_data,
1222                                                                access_pdu_len);
1223         default:
1224             btstack_assert(false);
1225             return 1;
1226     }
1227 }
1228 
1229 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)) {
1230     mesh_access_message_handler = callback;
1231 }
1232 
1233 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)){
1234     mesh_control_message_handler = callback;
1235 }
1236 
1237 void mesh_upper_transport_init(){
1238     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1239 }
1240 
1241 
1242 void mesh_upper_transport_message_init(mesh_upper_transport_builder_t * builder, mesh_pdu_type_t pdu_type) {
1243     btstack_assert(builder != NULL);
1244 
1245     builder->pdu = btstack_memory_mesh_upper_transport_pdu_get();
1246     if (!builder->pdu) return;
1247 
1248     builder->segment = NULL;
1249     builder->pdu->pdu_header.pdu_type = pdu_type;
1250     builder->pdu->ack_opcode = MESH_ACCESS_OPCODE_NOT_SET;
1251 }
1252 
1253 
1254 void mesh_upper_transport_message_add_data(mesh_upper_transport_builder_t * builder, const uint8_t * data, uint16_t data_len){
1255     btstack_assert(builder != NULL);
1256 
1257     if (builder->pdu == NULL) return;
1258 
1259     uint16_t bytes_current_segment = 0;
1260     if (builder->segment){
1261         bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX - builder->segment->len;
1262     }
1263     while (data_len > 0){
1264         if (bytes_current_segment == 0){
1265             builder->segment = (mesh_network_pdu_t *) mesh_network_pdu_get();
1266             if (builder->segment == NULL) {
1267                 mesh_upper_transport_pdu_free((mesh_pdu_t *) builder->pdu);
1268                 builder->pdu = NULL;
1269                 return;
1270             }
1271             btstack_linked_list_add_tail(&builder->pdu->segments, (btstack_linked_item_t *) builder->segment);
1272             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
1273         }
1274         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, data_len);
1275         (void) memcpy(&builder->segment->data[builder->segment->len], data, bytes_to_copy);
1276         builder->segment->len += bytes_to_copy;
1277         bytes_current_segment -= bytes_to_copy;
1278         data                  += bytes_to_copy;
1279         data_len              -= bytes_to_copy;
1280     }
1281 }
1282 
1283 void mesh_upper_transport_message_add_uint8(mesh_upper_transport_builder_t * builder, uint8_t value){
1284     mesh_upper_transport_message_add_data(builder, &value, 1);
1285 }
1286 
1287 void mesh_upper_transport_message_add_uint16(mesh_upper_transport_builder_t * builder, uint16_t value){
1288     uint8_t buffer[2];
1289     little_endian_store_16(buffer, 0, value);
1290     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1291 }
1292 
1293 void mesh_upper_transport_message_add_uint24(mesh_upper_transport_builder_t * builder, uint16_t value){
1294     uint8_t buffer[3];
1295     little_endian_store_24(buffer, 0, value);
1296     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1297 }
1298 
1299 void mesh_upper_transport_message_add_uint32(mesh_upper_transport_builder_t * builder, uint16_t value){
1300     uint8_t buffer[4];
1301     little_endian_store_32(buffer, 0, value);
1302     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1303 }
1304 
1305 mesh_upper_transport_pdu_t * mesh_upper_transport_message_finalize(mesh_upper_transport_builder_t * builder){
1306     return builder->pdu;
1307 }
1308