xref: /btstack/src/mesh/mesh_upper_transport.c (revision c3fc3eea4954ba223ebdf124fe9e7b5de452e5ae)
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 access_pdu->dst;
172 }
173 
174 uint16_t mesh_access_ctl(mesh_access_pdu_t * access_pdu){
175     return access_pdu->ctl_ttl >> 7;
176 }
177 
178 uint32_t mesh_access_seq(mesh_access_pdu_t * access_pdu){
179     return access_pdu->seq;
180 }
181 
182 void mesh_access_set_ivi_nid(mesh_access_pdu_t * access_pdu, uint8_t ivi_nid){
183     access_pdu->ivi_nid = ivi_nid;
184 }
185 void mesh_access_set_ctl_ttl(mesh_access_pdu_t * access_pdu, uint8_t ctl_ttl){
186     access_pdu->ctl_ttl = ctl_ttl;
187 }
188 void mesh_access_set_seq(mesh_access_pdu_t * access_pdu, uint32_t seq){
189     access_pdu->seq = seq;
190 }
191 void mesh_access_set_src(mesh_access_pdu_t * access_pdu, uint16_t src){
192     access_pdu->src = src;
193 }
194 void mesh_access_set_dest(mesh_access_pdu_t * access_pdu, uint16_t dst){
195     access_pdu->dst = dst;
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             big_endian_store_24(nonce, 2, access_pdu->seq);
344             big_endian_store_16(nonce, 5, access_pdu->src);
345             big_endian_store_16(nonce, 7, access_pdu->dst);
346             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
347             break;
348         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
349         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
350             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
351             nonce[1] = upper_pdu->transmic_len == 8 ? 0x80 : 0x00;
352             // 'network header'
353             big_endian_store_24(nonce, 2, upper_pdu->seq);
354             big_endian_store_16(nonce, 5, upper_pdu->src);
355             big_endian_store_16(nonce, 7, upper_pdu->dst);
356             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
357             break;
358         default:
359             btstack_assert(0);
360             break;
361     }
362 }
363 
364 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
365     nonce[0] = 0x01;
366     transport_segmented_setup_nonce(nonce, pdu);
367     mesh_print_hex("AppNonce", nonce, 13);
368 }
369 
370 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
371     nonce[0] = 0x02;
372     transport_segmented_setup_nonce(nonce, pdu);
373     mesh_print_hex("DeviceNonce", nonce, 13);
374 }
375 
376 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
377     crypto_active = 0;
378     btstack_assert(mesh_access_ctl(access_pdu) == 0);
379     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
380     incoming_access_encrypted = NULL;
381     incoming_access_decrypted = NULL;
382     mesh_upper_transport_run();
383 }
384 
385 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
386     crypto_active = 0;
387     incoming_control_pdu = NULL;
388     mesh_upper_transport_run();
389 }
390 
391 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
392     UNUSED(arg);
393 
394     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
395     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
396 
397     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
398 
399     // store TransMIC
400     uint8_t trans_mic[8];
401     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
402     mesh_print_hex("TransMIC", trans_mic, incoming_access_decrypted->transmic_len);
403 
404     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], incoming_access_decrypted->transmic_len) == 0){
405         printf("TransMIC matches\n");
406 
407         // remove TransMIC from payload
408         incoming_access_decrypted->len -= incoming_access_decrypted->transmic_len;
409 
410         // if virtual address, update dst to pseudo_dst
411         if (mesh_network_address_virtual(mesh_access_dst(incoming_access_decrypted))){
412             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
413         }
414 
415         // pass to upper layer
416         btstack_assert(mesh_access_message_handler != NULL);
417         mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_access_decrypted;
418         mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
419 
420         printf("\n");
421 
422     } else {
423         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
424         if (akf){
425             printf("TransMIC does not match, try next key\n");
426             mesh_upper_transport_validate_access_message();
427         } else {
428             printf("TransMIC does not match device key, done\n");
429             // done
430             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
431         }
432     }
433 }
434 
435 static void mesh_upper_transport_validate_access_message_digest(void * arg){
436     UNUSED(arg);
437     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
438     uint8_t * upper_transport_pdu_data_in  = incoming_access_decrypted->data;
439     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
440 
441     mesh_network_pdu_t * unsegmented_pdu = NULL;
442     mesh_segmented_pdu_t * segmented_pdu = NULL;
443     switch (incoming_access_encrypted->pdu_type){
444         case MESH_PDU_TYPE_SEGMENTED:
445             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
446             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
447             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
448                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
449             break;
450         case MESH_PDU_TYPE_UNSEGMENTED:
451             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
452             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
453             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
454                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
455             break;
456         default:
457             btstack_assert(false);
458             break;
459     }
460 
461 }
462 
463 static void mesh_upper_transport_validate_access_message(void){
464     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
465     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
466 
467     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
468         printf("No valid transport key found\n");
469         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
470         return;
471     }
472     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
473     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
474 
475     if (message_key->akf){
476         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
477     } else {
478         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
479     }
480 
481     // store application / device key index
482     mesh_print_hex("AppOrDevKey", message_key->key, 16);
483     incoming_access_decrypted->appkey_index = message_key->appkey_index;
484 
485     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
486 
487     // decrypt ccm
488     crypto_active = 1;
489     uint16_t aad_len  = 0;
490     if (mesh_network_address_virtual(mesh_access_dst(incoming_access_decrypted))){
491         aad_len  = 16;
492     }
493     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, incoming_access_decrypted->transmic_len);
494 
495     if (aad_len){
496         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
497                                   &mesh_upper_transport_validate_access_message_digest, NULL);
498     } else {
499         mesh_upper_transport_validate_access_message_digest(NULL);
500     }
501 }
502 
503 static void mesh_upper_transport_process_access_message(void){
504     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
505     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - incoming_access_decrypted->transmic_len;
506     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
507 
508     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
509     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
510 
511     printf("AKF: %u\n",   akf);
512     printf("AID: %02x\n", aid);
513 
514     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_access_dst(incoming_access_decrypted),
515                                                          incoming_access_decrypted->netkey_index, akf, aid);
516     mesh_upper_transport_validate_access_message();
517 }
518 
519 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
520     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
521     mesh_upper_transport_run();
522 }
523 
524 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
525 
526     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
527     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
528 
529     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
530     btstack_linked_list_t free_segments = segmented_pdu->segments;
531     segmented_pdu->segments = NULL;
532     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
533 
534     // copy meta
535     segmented_pdu->len = upper_pdu->len;
536     segmented_pdu->netkey_index = upper_pdu->netkey_index;
537     segmented_pdu->transmic_len = upper_pdu->transmic_len;
538     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
539     segmented_pdu->flags = upper_pdu->flags;
540 
541     // setup segmented_pdu header
542     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
543     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
544     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
545     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
546     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
547     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
548     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
549 
550     // queue up
551     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
552     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
553 
554     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
555 }
556 
557 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
558 
559     // provide segment
560     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
561 
562     // setup network pdu
563     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
564     network_pdu->data[0] = upper_pdu->ivi_nid;
565     network_pdu->data[1] = upper_pdu->ctl_ttl;
566     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
567     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
568     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
569     network_pdu->netkey_index = upper_pdu->netkey_index;
570 
571     // setup access message
572     network_pdu->data[9] = upper_pdu->akf_aid_control;
573     btstack_assert(upper_pdu->len < 15);
574     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
575     network_pdu->len = 10 + upper_pdu->len;
576     network_pdu->flags = 0;
577 
578     // queue up
579     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
580 
581     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
582 }
583 
584 static void mesh_upper_transport_send_access_ccm(void * arg){
585     crypto_active = 0;
586 
587     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
588     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
589     // store TransMIC
590     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
591     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], upper_pdu->transmic_len);
592     upper_pdu->len += upper_pdu->transmic_len;
593     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
594     switch (upper_pdu->pdu_header.pdu_type){
595         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
596             mesh_upper_transport_send_access_unsegmented(upper_pdu);
597             break;
598         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
599             mesh_upper_transport_send_access_segmented(upper_pdu);
600             break;
601         default:
602             btstack_assert(false);
603     }
604 }
605 
606 static void mesh_upper_transport_send_access_digest(void *arg){
607     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
608     uint16_t  access_pdu_len  = upper_pdu->len;
609     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
610                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
611 }
612 
613 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
614 
615     // if dst is virtual address, lookup label uuid and hash
616     uint16_t aad_len = 0;
617     mesh_virtual_address_t * virtual_address = NULL;
618     if (mesh_network_address_virtual(upper_pdu->dst)){
619         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
620         if (!virtual_address){
621             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
622             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
623             return;
624         }
625         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
626         // printf_hexdump(virtual_address->label_uuid, 16);
627         aad_len = 16;
628         upper_pdu->dst = virtual_address->hash;
629     }
630 
631     // get app or device key
632     uint16_t appkey_index = upper_pdu->appkey_index;
633     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
634     if (appkey == NULL){
635         printf("AppKey %04x not found, drop message\n", appkey_index);
636         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
637         return;
638     }
639 
640     // reserve slot
641     mesh_lower_transport_reserve_slot();
642 
643     // reserve one sequence number, which is also used to encrypt access payload
644     uint32_t seq = mesh_sequence_number_next();
645     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
646     upper_pdu->seq = seq;
647 
648     // also reserves crypto_buffer
649     crypto_active = 1;
650 
651     // flatten segmented pdu into crypto buffer
652     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
653     btstack_assert(payload_len == upper_pdu->len);
654 
655     // Dump PDU
656     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
657     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
658 
659     // setup nonce - uses dst, so after pseudo address translation
660     if (appkey_index == MESH_DEVICE_KEY_INDEX){
661         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
662     } else {
663         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
664     }
665 
666     // Dump key
667     mesh_print_hex("AppOrDevKey", appkey->key, 16);
668 
669     // encrypt ccm
670     uint8_t   transmic_len    = upper_pdu->transmic_len;
671     uint16_t  access_pdu_len  = upper_pdu->len;
672     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
673     if (virtual_address){
674         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
675         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
676                                   &mesh_upper_transport_send_access_digest, upper_pdu);
677     } else {
678         mesh_upper_transport_send_access_digest(upper_pdu);
679     }
680 }
681 
682 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
683     // reserve slot
684     mesh_lower_transport_reserve_slot();
685     // reserve sequence number
686     uint32_t seq = mesh_sequence_number_next();
687     mesh_network_pdu_set_seq(network_pdu, seq);
688     // Dump PDU
689     uint8_t opcode = network_pdu->data[9];
690     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
691     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
692 
693     // send
694      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
695 }
696 
697 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
698     // reserve slot
699     mesh_lower_transport_reserve_slot();
700     // reserve sequence number
701     uint32_t seq = mesh_sequence_number_next();
702     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
703     upper_pdu->seq = seq;
704     // Dump PDU
705     // uint8_t opcode = upper_pdu->data[0];
706     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
707     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
708     // send
709     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
710     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
711 
712     // lend segments to lower transport pdu
713     segmented_pdu->segments = upper_pdu->segments;
714     upper_pdu->segments = NULL;
715 
716     // copy meta
717     segmented_pdu->len = upper_pdu->len;
718     segmented_pdu->netkey_index = upper_pdu->netkey_index;
719     segmented_pdu->transmic_len = 0;   // no TransMIC for control
720     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
721     segmented_pdu->flags = upper_pdu->flags;
722 
723     // setup segmented_pdu header
724     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
725     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
726     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
727     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
728     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
729     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
730 
731     // queue up
732     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
733     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
734 
735     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
736 }
737 
738 static void mesh_upper_transport_run(void){
739 
740     while(!btstack_linked_list_empty(&upper_transport_incoming)){
741 
742         if (crypto_active) return;
743 
744         // get next message
745         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
746         mesh_network_pdu_t   * network_pdu;
747         mesh_segmented_pdu_t   * message_pdu;
748         switch (pdu->pdu_type){
749             case MESH_PDU_TYPE_UNSEGMENTED:
750                 network_pdu = (mesh_network_pdu_t *) pdu;
751                 // control?
752                 if (mesh_network_control(network_pdu)) {
753 
754                     incoming_control_pdu =  &incoming_pdu_singleton.control;
755                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
756                     incoming_control_pdu->len =  network_pdu->len;
757                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
758 
759                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
760 
761                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
762                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
763                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
764 
765                     // copy meta data into encrypted pdu buffer
766                     (void)memcpy(incoming_control_pdu->network_header, network_pdu->data, 9);
767 
768                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
769 
770                     // free mesh message
771                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
772 
773                     btstack_assert(mesh_control_message_handler != NULL);
774                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
775                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
776 
777                 } else {
778 
779                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
780 
781                     incoming_access_decrypted = &incoming_pdu_singleton.access;
782                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
783                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
784                     incoming_access_decrypted->transmic_len = 4;
785                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
786                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
787                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
788                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
789                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
790                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
791                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
792                     //  (void)memcpy(incoming_access_decrypted->network_header, network_pdu->data, 9);
793 
794                     mesh_upper_transport_process_access_message();
795                 }
796                 break;
797             case MESH_PDU_TYPE_SEGMENTED:
798                 message_pdu = (mesh_segmented_pdu_t *) pdu;
799                 uint8_t ctl = mesh_message_ctl(message_pdu);
800                 if (ctl){
801                     incoming_control_pdu=  &incoming_pdu_singleton.control;
802                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
803 
804                     // flatten
805                     mesh_segmented_pdu_flatten(&message_pdu->segments, 8, incoming_control_pdu->data);
806 
807                     // copy meta data into encrypted pdu buffer
808                     incoming_control_pdu->len =  message_pdu->len;
809                     incoming_access_decrypted->netkey_index =  message_pdu->netkey_index;
810                     incoming_control_pdu->akf_aid_control =  message_pdu->akf_aid_control;
811                     incoming_control_pdu->flags = 0;
812                     (void)memcpy(incoming_control_pdu->network_header, message_pdu->network_header, 9);
813 
814                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
815 
816                     // free mesh message
817                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
818 
819                     btstack_assert(mesh_control_message_handler != NULL);
820                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
821                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
822 
823                 } else {
824 
825                     incoming_access_encrypted = (mesh_pdu_t *) message_pdu;
826 
827                     incoming_access_decrypted = &incoming_pdu_singleton.access;
828                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
829                     incoming_access_decrypted->len =  message_pdu->len;
830                     incoming_access_decrypted->netkey_index =  message_pdu->netkey_index;
831                     incoming_access_decrypted->transmic_len =  message_pdu->transmic_len;
832                     incoming_access_decrypted->akf_aid_control =  message_pdu->akf_aid_control;
833                     incoming_access_decrypted->ivi_nid = message_pdu->network_header[0];
834                     incoming_access_decrypted->ctl_ttl = message_pdu->network_header[1];
835                     incoming_access_decrypted->seq = big_endian_read_24(message_pdu->network_header, 2);
836                     incoming_access_decrypted->src = big_endian_read_16(message_pdu->network_header, 5);
837                     incoming_access_decrypted->dst = big_endian_read_16(message_pdu->network_header, 7);
838 //                    (void)memcpy(incoming_access_decrypted->network_header, message_pdu->network_header, 9);
839 
840                     mesh_upper_transport_process_access_message();
841                 }
842                 break;
843             default:
844                 btstack_assert(0);
845                 break;
846         }
847     }
848 
849     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
850 
851         if (crypto_active) break;
852 
853         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
854         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
855 
856         mesh_upper_transport_pdu_t * upper_pdu;
857         mesh_segmented_pdu_t * segmented_pdu;
858         bool ok;
859 
860         switch (pdu->pdu_type){
861             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
862                 // control pdus can go through directly
863                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
864                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
865                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
866                 break;
867             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
868                 // control pdus can go through directly
869                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
870                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
871                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
872                 break;
873             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
874                 // segmented access pdus required a mesh-segmented-pdu
875                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
876                 if (upper_pdu->lower_pdu == NULL){
877                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
878                 }
879                 if (segmented_pdu == NULL) break;
880                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
881                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
882                 // and a mesh-network-pdu for each segment in upper pdu
883                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + upper_pdu->transmic_len);
884                 if (!ok) break;
885                 // all buffers available, get started
886                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
887                 mesh_upper_transport_send_access(upper_pdu);
888                 break;
889             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
890                 // unsegmented access pdus require a single mesh-network-dpu
891                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
892                 if (upper_pdu->lower_pdu == NULL){
893                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
894                 }
895                 if (upper_pdu->lower_pdu == NULL) break;
896                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
897                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
898                 break;
899             default:
900                 btstack_assert(false);
901                 break;
902         }
903     }
904 }
905 
906 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
907     btstack_linked_list_iterator_t it;
908     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
909     mesh_upper_transport_pdu_t * upper_pdu;
910     while (btstack_linked_list_iterator_has_next(&it)){
911         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
912         switch (mesh_pdu->pdu_type){
913             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
914             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
915             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
916                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
917                 if (upper_pdu->lower_pdu == pdu_to_find){
918                     btstack_linked_list_iterator_remove(&it);
919                     return upper_pdu;
920                 }
921                 break;
922             default:
923                 break;
924         }
925     }
926     return NULL;
927 }
928 
929 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
930     mesh_upper_transport_pdu_t * upper_pdu;
931     mesh_network_pdu_t * network_pdu;
932     mesh_segmented_pdu_t * segmented_pdu;
933     switch (callback_type){
934         case MESH_TRANSPORT_PDU_RECEIVED:
935             mesh_upper_transport_message_received(pdu);
936             break;
937         case MESH_TRANSPORT_PDU_SENT:
938             switch (pdu->pdu_type){
939                 case MESH_PDU_TYPE_SEGMENTED:
940                     // try to find in outgoing active
941                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
942                     btstack_assert(upper_pdu != NULL);
943                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
944                     // free chunks
945                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
946                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
947                         mesh_network_pdu_free(network_pdu);
948                     }
949                     // free segmented pdu
950                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
951                     // TODO: free segmented_pdu
952                     upper_pdu->lower_pdu = NULL;
953                     switch (upper_pdu->pdu_header.pdu_type){
954                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
955                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
956                             break;
957                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
958                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
959                             break;
960                         default:
961                             btstack_assert(false);
962                             break;
963                     }
964                     break;
965                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
966                     // find corresponding upper transport pdu and free single segment
967                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
968                     btstack_assert(upper_pdu != NULL);
969                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
970                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
971                     upper_pdu->lower_pdu = NULL;
972                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
973                     break;
974                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
975                     mesh_access_message_handler(callback_type, status, pdu);
976                     break;
977                 default:
978                     btstack_assert(false);
979                     break;
980             }
981             mesh_upper_transport_run();
982             break;
983         default:
984             break;
985     }
986 }
987 
988 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
989     mesh_network_pdu_t   * network_pdu;
990     mesh_segmented_pdu_t   * message_pdu;
991     switch (pdu->pdu_type) {
992         case MESH_PDU_TYPE_NETWORK:
993             network_pdu = (mesh_network_pdu_t *) pdu;
994             mesh_network_pdu_free(network_pdu);
995             break;
996         case MESH_PDU_TYPE_SEGMENTED:
997             message_pdu = (mesh_segmented_pdu_t *) pdu;
998             mesh_message_pdu_free(message_pdu);
999         default:
1000             btstack_assert(false);
1001             break;
1002     }
1003 }
1004 
1005 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1006     crypto_active = 0;
1007     switch (pdu->pdu_type){
1008         case MESH_PDU_TYPE_ACCESS:
1009             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1010         case MESH_PDU_TYPE_CONTROL:
1011             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1012             break;
1013         default:
1014             btstack_assert(0);
1015             break;
1016     }
1017 }
1018 
1019 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1020     switch (pdu->pdu_type){
1021         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1022         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1023             break;
1024         default:
1025             btstack_assert(false);
1026             break;
1027     }
1028 
1029     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1030 
1031     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1032     mesh_upper_transport_run();
1033 }
1034 
1035 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1036     switch (pdu->pdu_type){
1037         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1038             break;
1039         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1040             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1041             break;
1042         default:
1043             btstack_assert(false);
1044             break;
1045     }
1046 
1047     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1048     mesh_upper_transport_run();
1049 }
1050 
1051 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,
1052                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1053 
1054     if (control_pdu_len > 11) return 1;
1055 
1056     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1057     if (!network_key) return 1;
1058 
1059     uint8_t transport_pdu_data[12];
1060     transport_pdu_data[0] = opcode;
1061     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1062     uint16_t transport_pdu_len = control_pdu_len + 1;
1063 
1064     // setup network_pdu
1065     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1066 
1067     return 0;
1068 }
1069 
1070 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,
1071                                                                 const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1072 
1073     if (control_pdu_len > 256) return 1;
1074 
1075     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1076     if (!network_key) return 1;
1077 
1078     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1079     upper_pdu->ctl_ttl = ttl;
1080     upper_pdu->src = src;
1081     upper_pdu->dst = dest;
1082     upper_pdu->transmic_len = 0;    // no TransMIC for control
1083     upper_pdu->netkey_index = netkey_index;
1084     upper_pdu->akf_aid_control = opcode;
1085 
1086     // allocate segments
1087     btstack_linked_list_t free_segments = NULL;
1088     bool ok = mesh_segmented_allocate_segments( &free_segments, control_pdu_len);
1089     if (!ok) return 1;
1090     // store control pdu
1091     mesh_segmented_store_payload(control_pdu_data, control_pdu_len, &free_segments, &upper_pdu->segments);
1092     upper_pdu->len = control_pdu_len;
1093     return 0;
1094 }
1095 
1096 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
1097                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1098     switch (pdu->pdu_type){
1099         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1100             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);
1101         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1102             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);
1103         default:
1104             btstack_assert(0);
1105             return 1;
1106     }
1107 }
1108 
1109 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_access_pdu_t * access_pdu, uint16_t netkey_index,
1110                                                                       uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1111 
1112     // get app or device key
1113     const mesh_transport_key_t *appkey;
1114     appkey = mesh_transport_key_get(appkey_index);
1115     if (appkey == NULL) {
1116         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1117         return 1;
1118     }
1119     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1120 
1121     // lookup network by netkey_index
1122     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1123     if (!network_key) return 1;
1124     if (network_key == NULL) {
1125         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1126         return 1;
1127     }
1128 
1129     const uint8_t trans_mic_len = szmic ? 8 : 4;
1130 
1131     // store in transport pdu
1132     access_pdu->transmic_len = trans_mic_len;
1133     access_pdu->netkey_index = netkey_index;
1134     access_pdu->appkey_index = appkey_index;
1135     access_pdu->akf_aid_control = akf_aid;
1136     mesh_access_set_ivi_nid(access_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
1137     mesh_access_set_src(access_pdu, src);
1138     mesh_access_set_dest(access_pdu, dest);
1139     mesh_access_set_ctl_ttl(access_pdu, ttl);
1140     return 0;
1141 }
1142 
1143 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1144                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1145 
1146     // get app or device key
1147     const mesh_transport_key_t *appkey;
1148     appkey = mesh_transport_key_get(appkey_index);
1149     if (appkey == NULL) {
1150         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1151         return 1;
1152     }
1153     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1154 
1155     // lookup network by netkey_index
1156     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1157     if (!network_key) return 1;
1158     if (network_key == NULL) {
1159         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1160         return 1;
1161     }
1162 
1163     const uint8_t trans_mic_len = szmic ? 8 : 4;
1164 
1165     // store in transport pdu
1166     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1167     upper_pdu->ctl_ttl = ttl;
1168     upper_pdu->src = src;
1169     upper_pdu->dst = dest;
1170     upper_pdu->transmic_len = trans_mic_len;
1171     upper_pdu->netkey_index = netkey_index;
1172     upper_pdu->appkey_index = appkey_index;
1173     upper_pdu->akf_aid_control = akf_aid;
1174     return 0;
1175 }
1176 
1177 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,
1178                                                            uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1179     int status = mesh_upper_transport_setup_upper_access_pdu_header(upper_pdu, netkey_index, appkey_index, ttl, src,
1180                                                                     dest, szmic);
1181     if (status) return status;
1182 
1183     // allocate segments
1184     btstack_linked_list_t free_segments = NULL;
1185     bool ok = mesh_segmented_allocate_segments( &free_segments, access_pdu_len);
1186     if (!ok) return 1;
1187     // store control pdu
1188     mesh_segmented_store_payload(access_pdu_data, access_pdu_len, &free_segments, &upper_pdu->segments);
1189     upper_pdu->len = access_pdu_len;
1190     return 0;
1191 }
1192 
1193 
1194 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1195                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1196     switch (pdu->pdu_type){
1197         case MESH_PDU_TYPE_ACCESS:
1198             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_access_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
1199         default:
1200             btstack_assert(false);
1201             return 1;
1202     }
1203 }
1204 
1205 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1206                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
1207                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1208     switch (pdu->pdu_type){
1209         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1210         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1211             return mesh_upper_transport_setup_upper_access_pdu((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1212                                                                appkey_index, ttl, src, dest, szmic, access_pdu_data,
1213                                                                access_pdu_len);
1214         default:
1215             btstack_assert(false);
1216             return 1;
1217     }
1218 }
1219 
1220 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)) {
1221     mesh_access_message_handler = callback;
1222 }
1223 
1224 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)){
1225     mesh_control_message_handler = callback;
1226 }
1227 
1228 void mesh_upper_transport_init(){
1229     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1230 }
1231