xref: /btstack/src/mesh/mesh_upper_transport.c (revision 5368239bb9c5d6ef90a19e605021a8fc465f9987)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "mesh_upper_transport.c"
39 
40 #include "mesh/mesh_upper_transport.h"
41 
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "btstack_util.h"
47 #include "btstack_memory.h"
48 #include "btstack_debug.h"
49 #include "btstack_bool.h"
50 
51 #include "mesh/beacon.h"
52 #include "mesh/mesh_iv_index_seq_number.h"
53 #include "mesh/mesh_keys.h"
54 #include "mesh/mesh_lower_transport.h"
55 #include "mesh/mesh_peer.h"
56 #include "mesh/mesh_virtual_addresses.h"
57 
58 // TODO: extract mesh_pdu functions into lower transport or network
59 #include "mesh/mesh_access.h"
60 
61 // combined key x address iterator for upper transport decryption
62 
63 typedef struct {
64     // state
65     mesh_transport_key_iterator_t  key_it;
66     mesh_virtual_address_iterator_t address_it;
67     // elements
68     const mesh_transport_key_t *   key;
69     const mesh_virtual_address_t * address;
70     // address - might be virtual
71     uint16_t dst;
72     // key info
73 } mesh_transport_key_and_virtual_address_iterator_t;
74 
75 static void mesh_upper_transport_validate_segmented_message(void);
76 static void mesh_upper_transport_run(void);
77 
78 // upper transport callbacks - in access layer
79 static void (*mesh_access_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
80 static void (*mesh_control_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
81 
82 //
83 static int crypto_active;
84 static uint8_t application_nonce[13];
85 static btstack_crypto_ccm_t ccm;
86 static uint8_t crypto_buffer[MESH_ACCESS_PAYLOAD_MAX];
87 
88 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
89 
90 static mesh_access_pdu_t *   incoming_access_pdu_encrypted;
91 static mesh_access_pdu_t *   incoming_access_pdu_decrypted;
92 
93 static mesh_access_pdu_t     incoming_access_pdu_encrypted_singleton;
94 static mesh_access_pdu_t     incoming_access_pdu_decrypted_singleton;
95 
96 static mesh_control_pdu_t    incoming_control_pdu_singleton;
97 static mesh_control_pdu_t *  incoming_control_pdu;
98 
99 // incoming unsegmented (network) and segmented (transport) control and access messages
100 static btstack_linked_list_t upper_transport_incoming;
101 
102 // outgoing unsegmented and segmented control and access messages
103 static btstack_linked_list_t upper_transport_outgoing;
104 
105 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
106 static btstack_linked_list_t upper_transport_outgoing_active;
107 
108 // TODO: higher layer define used for assert
109 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
110 
111 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
112     printf("%-20s ", name);
113     printf_hexdump(data, len);
114 }
115 // static void mesh_print_x(const char * name, uint32_t value){
116 //     printf("%20s: 0x%x", name, (int) value);
117 // }
118 
119 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
120                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
121                                                                  uint8_t aid) {
122     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
123     // config
124     it->dst   = dst;
125     // init elements
126     it->key     = NULL;
127     it->address = NULL;
128     // init element iterators
129     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
130     // init address iterator
131     if (mesh_network_address_virtual(it->dst)){
132         mesh_virtual_address_iterator_init(&it->address_it, dst);
133         // get first key
134         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
135             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
136         }
137     }
138 }
139 
140 // cartesian product: keys x addressses
141 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
142     if (mesh_network_address_virtual(it->dst)) {
143         // find next valid entry
144         while (true){
145             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
146             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
147             // get next key
148             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
149             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
150         }
151     } else {
152         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
153     }
154 }
155 
156 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
157     if (mesh_network_address_virtual(it->dst)) {
158         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
159     } else {
160         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
161     }
162 }
163 
164 // UPPER TRANSPORT
165 
166 uint16_t mesh_access_dst(mesh_access_pdu_t * access_pdu){
167     return big_endian_read_16(access_pdu->network_header, 7);
168 }
169 
170 uint16_t mesh_access_ctl(mesh_access_pdu_t * access_pdu){
171     return access_pdu->network_header[1] >> 7;
172 }
173 
174 uint32_t mesh_access_seq(mesh_access_pdu_t * access_pdu){
175     return big_endian_read_24(access_pdu->network_header, 2);
176 }
177 
178 void mesh_access_set_nid_ivi(mesh_access_pdu_t * access_pdu, uint8_t nid_ivi){
179     access_pdu->network_header[0] = nid_ivi;
180 }
181 void mesh_access_set_ctl_ttl(mesh_access_pdu_t * access_pdu, uint8_t ctl_ttl){
182     access_pdu->network_header[1] = ctl_ttl;
183 }
184 void mesh_access_set_seq(mesh_access_pdu_t * access_pdu, uint32_t seq){
185     big_endian_store_24(access_pdu->network_header, 2, seq);
186 }
187 void mesh_access_set_src(mesh_access_pdu_t * access_pdu, uint16_t src){
188     big_endian_store_16(access_pdu->network_header, 5, src);
189 }
190 void mesh_access_set_dest(mesh_access_pdu_t * access_pdu, uint16_t dest){
191     big_endian_store_16(access_pdu->network_header, 7, dest);
192 }
193 
194 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
195     // assemble payload
196     btstack_linked_list_iterator_t it;
197     btstack_linked_list_iterator_init(&it, segments);
198     while (btstack_linked_list_iterator_has_next(&it)) {
199         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
200         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
201         // get segment n
202         uint8_t *lower_transport_pdu = mesh_network_pdu_data(segment);
203         uint8_t seg_o = (big_endian_read_16(lower_transport_pdu, 2) >> 5) & 0x001f;
204         uint8_t *segment_data = &lower_transport_pdu[4];
205         (void) memcpy(&buffer[seg_o * segment_len], segment_data, segment_len);
206     }
207 }
208 
209 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
210     // assemble payload
211     btstack_linked_list_iterator_t it;
212     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
213     uint16_t offset = 0;
214     while (btstack_linked_list_iterator_has_next(&it)) {
215         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
216         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
217         btstack_assert((offset + segment->len) <= buffer_len);
218         (void) memcpy(&buffer[offset], segment->data, segment->len);
219         offset += segment->len;
220     }
221     return offset;
222 }
223 
224 // store payload in provided list of network pdus
225 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){
226     uint16_t payload_offset = 0;
227     uint16_t bytes_current_segment = 0;
228     mesh_network_pdu_t * network_pdu = NULL;
229     while (payload_offset < payload_len){
230         if (bytes_current_segment == 0){
231             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
232             btstack_assert(network_pdu != NULL);
233             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
234             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
235         }
236         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
237         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
238         bytes_current_segment -= bytes_to_copy;
239         network_pdu->len += bytes_to_copy;
240         payload_offset += bytes_to_copy;
241     }
242 }
243 
244 // tries allocate and add enough segments to store payload of given size
245 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
246     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
247     while (storage_size < payload_len){
248         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
249         if (network_pdu == NULL) break;
250         storage_size += MESH_NETWORK_PAYLOAD_MAX;
251         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
252     }
253     return (storage_size >= payload_len);
254 }
255 
256 // stub lower transport
257 
258 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
259     printf("List: %s:\n", name);
260     btstack_linked_list_iterator_t it;
261     btstack_linked_list_iterator_init(&it, list);
262     while (btstack_linked_list_iterator_has_next(&it)){
263         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
264         printf("- %p\n", pdu);
265         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
266     }
267 }
268 
269 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
270     while (!btstack_linked_list_empty(list)){
271         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
272     }
273 }
274 
275 void mesh_upper_transport_dump(void){
276     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
277 }
278 
279 void mesh_upper_transport_reset(void){
280     crypto_active = 0;
281     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
282 }
283 
284 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
285     // Device Key is fixed
286     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
287         return mesh_transport_key_get(appkey_index);
288     }
289 
290     // Get key refresh state from subnet
291     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
292     if (subnet == NULL) return NULL;
293 
294     // identify old and new app keys for given appkey_index
295     mesh_transport_key_t * old_key = NULL;
296     mesh_transport_key_t * new_key = NULL;
297     mesh_transport_key_iterator_t it;
298     mesh_transport_key_iterator_init(&it, netkey_index);
299     while (mesh_transport_key_iterator_has_more(&it)){
300         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
301         if (transport_key->appkey_index != appkey_index) continue;
302         if (transport_key->old_key == 0) {
303             new_key = transport_key;
304         } else {
305             old_key = transport_key;
306         }
307     }
308 
309     // if no key is marked as old, just use the current one
310     if (old_key == NULL) return new_key;
311 
312     // use new key if it exists in phase two
313     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
314         return new_key;
315     } else {
316         return old_key;
317     }
318 }
319 
320 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
321     // get IV Index and IVI
322     uint32_t iv_index = mesh_get_iv_index();
323     int ivi = ivi_nid >> 7;
324 
325     // if least significant bit differs, use previous IV Index
326     if ((iv_index & 1 ) ^ ivi){
327         iv_index--;
328     }
329     return iv_index;
330 }
331 
332 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
333     mesh_access_pdu_t * access_pdu;
334     mesh_upper_transport_pdu_t * upper_pdu;
335     switch (pdu->pdu_type){
336         case MESH_PDU_TYPE_ACCESS:
337             access_pdu = (mesh_access_pdu_t *) pdu;
338             nonce[1] = access_pdu->transmic_len == 8 ? 0x80 : 0x00;
339             (void)memcpy(&nonce[2], &access_pdu->network_header[2], 7);
340             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->network_header[0]));
341             break;
342         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
343         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
344             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
345             nonce[1] = upper_pdu->transmic_len == 8 ? 0x80 : 0x00;
346             // 'network header'
347             big_endian_store_24(nonce, 2, upper_pdu->seq);
348             big_endian_store_16(nonce, 5, upper_pdu->src);
349             big_endian_store_16(nonce, 7, upper_pdu->dst);
350             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
351             break;
352         default:
353             btstack_assert(0);
354             break;
355     }
356 }
357 
358 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
359     nonce[0] = 0x01;
360     transport_segmented_setup_nonce(nonce, pdu);
361     mesh_print_hex("AppNonce", nonce, 13);
362 }
363 
364 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
365     nonce[0] = 0x02;
366     transport_segmented_setup_nonce(nonce, pdu);
367     mesh_print_hex("DeviceNonce", nonce, 13);
368 }
369 
370 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
371     crypto_active = 0;
372     btstack_assert(mesh_access_ctl(access_pdu) == 0);
373     incoming_access_pdu_encrypted = NULL;
374     mesh_upper_transport_run();
375 }
376 
377 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
378     crypto_active = 0;
379     incoming_control_pdu = NULL;
380     mesh_upper_transport_run();
381 }
382 
383 static void mesh_upper_transport_validate_segmented_message_ccm(void * arg){
384     UNUSED(arg);
385 
386     uint8_t * upper_transport_pdu     = incoming_access_pdu_decrypted->data;
387     uint8_t   upper_transport_pdu_len = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
388 
389     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
390 
391     // store TransMIC
392     uint8_t trans_mic[8];
393     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
394     mesh_print_hex("TransMIC", trans_mic, incoming_access_pdu_decrypted->transmic_len);
395 
396     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], incoming_access_pdu_decrypted->transmic_len) == 0){
397         printf("TransMIC matches\n");
398 
399         // remove TransMIC from payload
400         incoming_access_pdu_decrypted->len -= incoming_access_pdu_decrypted->transmic_len;
401 
402         // if virtual address, update dst to pseudo_dst
403         if (mesh_network_address_virtual(mesh_access_dst(incoming_access_pdu_decrypted))){
404             big_endian_store_16(incoming_access_pdu_decrypted->network_header, 7, mesh_transport_key_it.address->pseudo_dst);
405         }
406 
407         // pass to upper layer
408         btstack_assert(mesh_access_message_handler != NULL);
409         mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_access_pdu_decrypted;
410         mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
411 
412         printf("\n");
413 
414     } else {
415         uint8_t akf = incoming_access_pdu_decrypted->akf_aid_control & 0x40;
416         if (akf){
417             printf("TransMIC does not match, try next key\n");
418             mesh_upper_transport_validate_segmented_message();
419         } else {
420             printf("TransMIC does not match device key, done\n");
421             // done
422             mesh_upper_transport_process_access_message_done(incoming_access_pdu_decrypted);
423         }
424     }
425 }
426 
427 static void mesh_upper_transport_validate_segmented_message_digest(void * arg){
428     UNUSED(arg);
429     uint8_t   upper_transport_pdu_len      = incoming_access_pdu_encrypted->len - incoming_access_pdu_encrypted->transmic_len;
430     uint8_t * upper_transport_pdu_data_in  = incoming_access_pdu_encrypted->data;
431     uint8_t * upper_transport_pdu_data_out = incoming_access_pdu_decrypted->data;
432     btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_in, upper_transport_pdu_data_out, &mesh_upper_transport_validate_segmented_message_ccm, NULL);
433 }
434 
435 static void mesh_upper_transport_validate_segmented_message(void){
436     uint8_t * upper_transport_pdu_data =  incoming_access_pdu_decrypted->data;
437     uint8_t   upper_transport_pdu_len  = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
438 
439     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
440         printf("No valid transport key found\n");
441         mesh_upper_transport_process_access_message_done(incoming_access_pdu_decrypted);
442         return;
443     }
444     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
445     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
446 
447     if (message_key->akf){
448         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_pdu_encrypted);
449     } else {
450         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_pdu_encrypted);
451     }
452 
453     // store application / device key index
454     mesh_print_hex("AppOrDevKey", message_key->key, 16);
455     incoming_access_pdu_decrypted->appkey_index = message_key->appkey_index;
456 
457     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
458 
459     // decrypt ccm
460     crypto_active = 1;
461     uint16_t aad_len  = 0;
462     if (mesh_network_address_virtual(mesh_access_dst(incoming_access_pdu_decrypted))){
463         aad_len  = 16;
464     }
465     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, incoming_access_pdu_decrypted->transmic_len);
466 
467     if (aad_len){
468         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_segmented_message_digest, NULL);
469     } else {
470         mesh_upper_transport_validate_segmented_message_digest(NULL);
471     }
472 }
473 
474 static void mesh_upper_transport_process_segmented_message(void){
475     // copy original pdu
476     (void)memcpy(incoming_access_pdu_decrypted, incoming_access_pdu_encrypted,
477                  sizeof(mesh_access_pdu_t));
478 
479     //
480     uint8_t * upper_transport_pdu     =  incoming_access_pdu_decrypted->data;
481     uint8_t   upper_transport_pdu_len = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
482     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
483 
484     uint8_t aid = incoming_access_pdu_decrypted->akf_aid_control & 0x3f;
485     uint8_t akf = (incoming_access_pdu_decrypted->akf_aid_control & 0x40) >> 6;
486 
487     printf("AKF: %u\n",   akf);
488     printf("AID: %02x\n", aid);
489 
490     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_access_dst(incoming_access_pdu_decrypted),
491                                                          incoming_access_pdu_decrypted->netkey_index, akf, aid);
492     mesh_upper_transport_validate_segmented_message();
493 }
494 
495 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
496     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
497     mesh_upper_transport_run();
498 }
499 
500 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
501 
502     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
503     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
504 
505     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
506     btstack_linked_list_t free_segments = segmented_pdu->segments;
507     segmented_pdu->segments = NULL;
508     mesh_segmented_store_payload(crypto_buffer, upper_pdu->len, &free_segments, &segmented_pdu->segments);
509 
510     // copy meta
511     segmented_pdu->len = upper_pdu->len;
512     segmented_pdu->netkey_index = upper_pdu->netkey_index;
513     segmented_pdu->transmic_len = upper_pdu->transmic_len;
514     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
515     segmented_pdu->flags = upper_pdu->flags;
516 
517     // setup segmented_pdu header
518     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
519     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
520     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
521     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
522     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
523     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
524     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
525 
526     // queue up
527     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
528     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
529 
530     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
531 }
532 
533 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
534 
535     // provide segment
536     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
537 
538     // setup network pdu
539     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
540     network_pdu->data[0] = upper_pdu->ivi_nid;
541     network_pdu->data[1] = upper_pdu->ctl_ttl;
542     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
543     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
544     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
545     network_pdu->netkey_index = upper_pdu->netkey_index;
546 
547     // setup access message
548     network_pdu->data[9] = upper_pdu->akf_aid_control;
549     btstack_assert(upper_pdu->len < 15);
550     (void)memcpy(&network_pdu->data[10], crypto_buffer, upper_pdu->len);
551     network_pdu->len = 10 + upper_pdu->len;
552     network_pdu->flags = 0;
553 
554     // queue up
555     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
556 
557     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
558 }
559 
560 static void mesh_upper_transport_send_access_ccm(void * arg){
561     crypto_active = 0;
562 
563     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
564     mesh_print_hex("EncAccessPayload", crypto_buffer, upper_pdu->len);
565     // store TransMIC
566     btstack_crypto_ccm_get_authentication_value(&ccm, &crypto_buffer[upper_pdu->len]);
567     mesh_print_hex("TransMIC", &crypto_buffer[upper_pdu->len], upper_pdu->transmic_len);
568     upper_pdu->len += upper_pdu->transmic_len;
569     mesh_print_hex("UpperTransportPDU", crypto_buffer, upper_pdu->len);
570     switch (upper_pdu->pdu_header.pdu_type){
571         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
572             mesh_upper_transport_send_access_unsegmented(upper_pdu);
573             break;
574         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
575             mesh_upper_transport_send_access_segmented(upper_pdu);
576             break;
577         default:
578             btstack_assert(false);
579     }
580 }
581 
582 static void mesh_upper_transport_send_access_digest(void *arg){
583     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
584     uint16_t  access_pdu_len  = upper_pdu->len;
585     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, crypto_buffer, crypto_buffer,
586                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
587 }
588 
589 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
590 
591     // if dst is virtual address, lookup label uuid and hash
592     uint16_t aad_len = 0;
593     mesh_virtual_address_t * virtual_address = NULL;
594     if (mesh_network_address_virtual(upper_pdu->dst)){
595         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
596         if (!virtual_address){
597             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
598             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
599             return;
600         }
601         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
602         // printf_hexdump(virtual_address->label_uuid, 16);
603         aad_len = 16;
604         upper_pdu->dst = virtual_address->hash;
605     }
606 
607     // get app or device key
608     uint16_t appkey_index = upper_pdu->appkey_index;
609     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
610     if (appkey == NULL){
611         printf("AppKey %04x not found, drop message\n", appkey_index);
612         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
613         return;
614     }
615 
616     // reserve slot
617     mesh_lower_transport_reserve_slot();
618 
619     // reserve one sequence number, which is also used to encrypt access payload
620     uint32_t seq = mesh_sequence_number_next();
621     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
622     upper_pdu->seq = seq;
623 
624     // also reserves crypto_buffer
625     crypto_active = 1;
626 
627     // flatten segmented pdu into crypto buffer
628     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, crypto_buffer, sizeof(crypto_buffer));
629     btstack_assert(payload_len == upper_pdu->len);
630 
631     // Dump PDU
632     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
633     mesh_print_hex("Access Payload", crypto_buffer, upper_pdu->len);
634 
635     // setup nonce - uses dst, so after pseudo address translation
636     if (appkey_index == MESH_DEVICE_KEY_INDEX){
637         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
638     } else {
639         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
640     }
641 
642     // Dump key
643     mesh_print_hex("AppOrDevKey", appkey->key, 16);
644 
645     // encrypt ccm
646     uint8_t   transmic_len    = upper_pdu->transmic_len;
647     uint16_t  access_pdu_len  = upper_pdu->len;
648     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
649     if (virtual_address){
650         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
651         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
652                                   &mesh_upper_transport_send_access_digest, upper_pdu);
653     } else {
654         mesh_upper_transport_send_access_digest(upper_pdu);
655     }
656 }
657 
658 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
659     // reserve slot
660     mesh_lower_transport_reserve_slot();
661     // reserve sequence number
662     uint32_t seq = mesh_sequence_number_next();
663     mesh_network_pdu_set_seq(network_pdu, seq);
664     // Dump PDU
665     uint8_t opcode = network_pdu->data[9];
666     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
667     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
668 
669     // send
670      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
671 }
672 
673 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
674     // reserve slot
675     mesh_lower_transport_reserve_slot();
676     // reserve sequence number
677     uint32_t seq = mesh_sequence_number_next();
678     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
679     upper_pdu->seq = seq;
680     // Dump PDU
681     // uint8_t opcode = upper_pdu->data[0];
682     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
683     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
684     // send
685     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
686     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
687 
688     // lend segments to lower transport pdu
689     segmented_pdu->segments = upper_pdu->segments;
690     upper_pdu->segments = NULL;
691 
692     // copy meta
693     segmented_pdu->len = upper_pdu->len;
694     segmented_pdu->netkey_index = upper_pdu->netkey_index;
695     segmented_pdu->transmic_len = 0;   // no TransMIC for control
696     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
697     segmented_pdu->flags = upper_pdu->flags;
698 
699     // setup segmented_pdu header
700     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
701     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
702     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
703     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
704     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
705     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
706 
707     // queue up
708     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
709     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
710 
711     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
712 }
713 
714 static void mesh_upper_transport_run(void){
715 
716     while(!btstack_linked_list_empty(&upper_transport_incoming)){
717 
718         if (crypto_active) return;
719 
720         // get next message
721         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
722         mesh_network_pdu_t   * network_pdu;
723         mesh_segmented_pdu_t   * message_pdu;
724         switch (pdu->pdu_type){
725             case MESH_PDU_TYPE_UNSEGMENTED:
726                 network_pdu = (mesh_network_pdu_t *) pdu;
727                 // control?
728                 if (mesh_network_control(network_pdu)) {
729 
730                     incoming_control_pdu =  &incoming_control_pdu_singleton;
731                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
732                     incoming_control_pdu->len =  network_pdu->len;
733                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
734 
735                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
736 
737                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
738                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
739                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
740 
741                     // copy meta data into encrypted pdu buffer
742                     (void)memcpy(incoming_control_pdu->network_header, network_pdu->data, 9);
743 
744                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
745 
746                     // free mesh message
747                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
748 
749                     btstack_assert(mesh_control_message_handler != NULL);
750                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
751                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
752 
753                 } else {
754 
755                     incoming_access_pdu_encrypted = &incoming_access_pdu_encrypted_singleton;
756                     incoming_access_pdu_encrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
757                     incoming_access_pdu_decrypted = &incoming_access_pdu_decrypted_singleton;
758 
759                     incoming_access_pdu_encrypted->netkey_index = network_pdu->netkey_index;
760                     incoming_access_pdu_encrypted->transmic_len = 4;
761 
762                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
763 
764                     incoming_access_pdu_encrypted->akf_aid_control = lower_transport_pdu[0];
765                     incoming_access_pdu_encrypted->len = network_pdu->len - 10; // 9 header + 1 AID
766                     (void)memcpy(incoming_access_pdu_encrypted->data, &lower_transport_pdu[1], incoming_access_pdu_encrypted->len);
767 
768                     // copy meta data into encrypted pdu buffer
769                     (void)memcpy(incoming_access_pdu_encrypted->network_header, network_pdu->data, 9);
770 
771                     mesh_print_hex("Assembled payload", incoming_access_pdu_encrypted->data, incoming_access_pdu_encrypted->len);
772 
773                     // free mesh message
774                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
775 
776                     // get encoded transport pdu and start processing
777                     mesh_upper_transport_process_segmented_message();
778                 }
779                 break;
780             case MESH_PDU_TYPE_SEGMENTED:
781                 message_pdu = (mesh_segmented_pdu_t *) pdu;
782                 uint8_t ctl = mesh_message_ctl(message_pdu);
783                 if (ctl){
784                     incoming_control_pdu=  &incoming_control_pdu_singleton;
785                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
786 
787                     // flatten
788                     mesh_segmented_pdu_flatten(&message_pdu->segments, 8, incoming_control_pdu->data);
789 
790                     // copy meta data into encrypted pdu buffer
791                     incoming_control_pdu->len =  message_pdu->len;
792                     incoming_control_pdu->netkey_index =  message_pdu->netkey_index;
793                     incoming_control_pdu->akf_aid_control =  message_pdu->akf_aid_control;
794                     incoming_control_pdu->flags = 0;
795                     (void)memcpy(incoming_control_pdu->network_header, message_pdu->network_header, 9);
796 
797                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
798 
799                     // free mesh message
800                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
801 
802                     btstack_assert(mesh_control_message_handler != NULL);
803                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
804                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
805 
806                 } else {
807 
808                     incoming_access_pdu_encrypted = &incoming_access_pdu_encrypted_singleton;
809                     incoming_access_pdu_encrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
810                     incoming_access_pdu_decrypted = &incoming_access_pdu_decrypted_singleton;
811 
812                     // flatten
813                     mesh_segmented_pdu_flatten(&message_pdu->segments, 12, incoming_access_pdu_encrypted->data);
814 
815                     // copy meta data into encrypted pdu buffer
816                     incoming_access_pdu_encrypted->len =  message_pdu->len;
817                     incoming_access_pdu_encrypted->netkey_index =  message_pdu->netkey_index;
818                     incoming_access_pdu_encrypted->transmic_len =  message_pdu->transmic_len;
819                     incoming_access_pdu_encrypted->akf_aid_control =  message_pdu->akf_aid_control;
820                     (void)memcpy(incoming_access_pdu_encrypted->network_header, message_pdu->network_header, 9);
821 
822                     mesh_print_hex("Assembled payload", incoming_access_pdu_encrypted->data, incoming_access_pdu_encrypted->len);
823 
824                     // free mesh message
825                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
826 
827                     // get encoded transport pdu and start processing
828                     mesh_upper_transport_process_segmented_message();
829                 }
830                 break;
831             default:
832                 btstack_assert(0);
833                 break;
834         }
835     }
836 
837     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
838 
839         if (crypto_active) break;
840 
841         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
842         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
843 
844         mesh_upper_transport_pdu_t * upper_pdu;
845         mesh_segmented_pdu_t * segmented_pdu;
846         bool ok;
847 
848         switch (pdu->pdu_type){
849             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
850                 // control pdus can go through directly
851                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
852                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
853                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
854                 break;
855             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
856                 // control pdus can go through directly
857                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
858                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
859                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
860                 break;
861             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
862                 // segmented access pdus required a mesh-segmented-pdu
863                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
864                 if (upper_pdu->lower_pdu == NULL){
865                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
866                 }
867                 if (segmented_pdu == NULL) break;
868                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
869                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
870                 // and a mesh-network-pdu for each segment in upper pdu
871                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + upper_pdu->transmic_len);
872                 if (!ok) break;
873                 // all buffers available, get started
874                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
875                 mesh_upper_transport_send_access(upper_pdu);
876                 break;
877             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
878                 // unsegmented access pdus require a single mesh-network-dpu
879                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
880                 if (upper_pdu->lower_pdu == NULL){
881                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
882                 }
883                 if (upper_pdu->lower_pdu == NULL) break;
884                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
885                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
886                 break;
887             default:
888                 btstack_assert(false);
889                 break;
890         }
891     }
892 }
893 
894 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
895     btstack_linked_list_iterator_t it;
896     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
897     mesh_upper_transport_pdu_t * upper_pdu;
898     while (btstack_linked_list_iterator_has_next(&it)){
899         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
900         switch (mesh_pdu->pdu_type){
901             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
902             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
903             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
904                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
905                 if (upper_pdu->lower_pdu == pdu_to_find){
906                     btstack_linked_list_iterator_remove(&it);
907                     return upper_pdu;
908                 }
909                 break;
910             default:
911                 break;
912         }
913     }
914     return NULL;
915 }
916 
917 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
918     mesh_upper_transport_pdu_t * upper_pdu;
919     mesh_network_pdu_t * network_pdu;
920     mesh_segmented_pdu_t * segmented_pdu;
921     switch (callback_type){
922         case MESH_TRANSPORT_PDU_RECEIVED:
923             mesh_upper_transport_message_received(pdu);
924             break;
925         case MESH_TRANSPORT_PDU_SENT:
926             switch (pdu->pdu_type){
927                 case MESH_PDU_TYPE_SEGMENTED:
928                     // try to find in outgoing active
929                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
930                     btstack_assert(upper_pdu != NULL);
931                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
932                     // free chunks
933                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
934                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
935                         mesh_network_pdu_free(network_pdu);
936                     }
937                     // free segmented pdu
938                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
939                     // TODO: free segmented_pdu
940                     upper_pdu->lower_pdu = NULL;
941                     switch (upper_pdu->pdu_header.pdu_type){
942                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
943                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
944                             break;
945                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
946                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
947                             break;
948                         default:
949                             btstack_assert(false);
950                             break;
951                     }
952                     break;
953                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
954                     // find corresponding upper transport pdu and free single segment
955                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
956                     btstack_assert(upper_pdu != NULL);
957                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
958                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
959                     upper_pdu->lower_pdu = NULL;
960                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
961                     break;
962                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
963                     mesh_access_message_handler(callback_type, status, pdu);
964                     break;
965                 default:
966                     btstack_assert(false);
967                     break;
968             }
969             mesh_upper_transport_run();
970             break;
971         default:
972             break;
973     }
974 }
975 
976 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
977     mesh_network_pdu_t   * network_pdu;
978     mesh_segmented_pdu_t   * message_pdu;
979     switch (pdu->pdu_type) {
980         case MESH_PDU_TYPE_NETWORK:
981             network_pdu = (mesh_network_pdu_t *) pdu;
982             mesh_network_pdu_free(network_pdu);
983             break;
984         case MESH_PDU_TYPE_SEGMENTED:
985             message_pdu = (mesh_segmented_pdu_t *) pdu;
986             mesh_message_pdu_free(message_pdu);
987         default:
988             btstack_assert(false);
989             break;
990     }
991 }
992 
993 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
994     crypto_active = 0;
995     switch (pdu->pdu_type){
996         case MESH_PDU_TYPE_ACCESS:
997             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
998         case MESH_PDU_TYPE_CONTROL:
999             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1000             break;
1001         default:
1002             btstack_assert(0);
1003             break;
1004     }
1005 }
1006 
1007 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1008     switch (pdu->pdu_type){
1009         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1010         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1011             break;
1012         default:
1013             btstack_assert(false);
1014             break;
1015     }
1016 
1017     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1018 
1019     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1020     mesh_upper_transport_run();
1021 }
1022 
1023 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1024     switch (pdu->pdu_type){
1025         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1026             break;
1027         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1028             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1029             break;
1030         default:
1031             btstack_assert(false);
1032             break;
1033     }
1034 
1035     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1036     mesh_upper_transport_run();
1037 }
1038 
1039 static uint8_t mesh_upper_transport_setup_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
1040                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1041 
1042     if (control_pdu_len > 11) return 1;
1043 
1044     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1045     if (!network_key) return 1;
1046 
1047     uint8_t transport_pdu_data[12];
1048     transport_pdu_data[0] = opcode;
1049     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1050     uint16_t transport_pdu_len = control_pdu_len + 1;
1051 
1052     // setup network_pdu
1053     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1054 
1055     return 0;
1056 }
1057 
1058 static uint8_t mesh_upper_transport_setup_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
1059                                                                 const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1060 
1061     if (control_pdu_len > 256) return 1;
1062 
1063     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1064     if (!network_key) return 1;
1065 
1066     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1067     upper_pdu->ctl_ttl = ttl;
1068     upper_pdu->src = src;
1069     upper_pdu->dst = dest;
1070     upper_pdu->transmic_len = 0;    // no TransMIC for control
1071     upper_pdu->netkey_index = netkey_index;
1072     upper_pdu->akf_aid_control = opcode;
1073 
1074     // allocate segments
1075     btstack_linked_list_t free_segments = NULL;
1076     bool ok = mesh_segmented_allocate_segments( &free_segments, control_pdu_len);
1077     if (!ok) return 1;
1078     // store control pdu
1079     mesh_segmented_store_payload(control_pdu_data, control_pdu_len, &free_segments, &upper_pdu->segments);
1080     upper_pdu->len = control_pdu_len;
1081     return 0;
1082 }
1083 
1084 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
1085                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1086     switch (pdu->pdu_type){
1087         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1088             return mesh_upper_transport_setup_unsegmented_control_pdu((mesh_network_pdu_t *) pdu, netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
1089         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1090             return mesh_upper_transport_setup_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu,  netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
1091         default:
1092             btstack_assert(0);
1093             return 1;
1094     }
1095 }
1096 
1097 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_access_pdu_t * access_pdu, uint16_t netkey_index,
1098                                                                       uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1099 
1100     // get app or device key
1101     const mesh_transport_key_t *appkey;
1102     appkey = mesh_transport_key_get(appkey_index);
1103     if (appkey == NULL) {
1104         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1105         return 1;
1106     }
1107     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1108 
1109     // lookup network by netkey_index
1110     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1111     if (!network_key) return 1;
1112     if (network_key == NULL) {
1113         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1114         return 1;
1115     }
1116 
1117     const uint8_t trans_mic_len = szmic ? 8 : 4;
1118 
1119     // store in transport pdu
1120     access_pdu->transmic_len = trans_mic_len;
1121     access_pdu->netkey_index = netkey_index;
1122     access_pdu->appkey_index = appkey_index;
1123     access_pdu->akf_aid_control = akf_aid;
1124     mesh_access_set_nid_ivi(access_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
1125     mesh_access_set_src(access_pdu, src);
1126     mesh_access_set_dest(access_pdu, dest);
1127     mesh_access_set_ctl_ttl(access_pdu, ttl);
1128     return 0;
1129 }
1130 
1131 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1132                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1133 
1134     // get app or device key
1135     const mesh_transport_key_t *appkey;
1136     appkey = mesh_transport_key_get(appkey_index);
1137     if (appkey == NULL) {
1138         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1139         return 1;
1140     }
1141     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1142 
1143     // lookup network by netkey_index
1144     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1145     if (!network_key) return 1;
1146     if (network_key == NULL) {
1147         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1148         return 1;
1149     }
1150 
1151     const uint8_t trans_mic_len = szmic ? 8 : 4;
1152 
1153     // store in transport pdu
1154     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1155     upper_pdu->ctl_ttl = ttl;
1156     upper_pdu->src = src;
1157     upper_pdu->dst = dest;
1158     upper_pdu->transmic_len = trans_mic_len;
1159     upper_pdu->netkey_index = netkey_index;
1160     upper_pdu->appkey_index = appkey_index;
1161     upper_pdu->akf_aid_control = akf_aid;
1162     return 0;
1163 }
1164 
1165 static uint8_t mesh_upper_transport_setup_upper_access_pdu(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
1166                                                            uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1167     int status = mesh_upper_transport_setup_upper_access_pdu_header(upper_pdu, netkey_index, appkey_index, ttl, src,
1168                                                                     dest, szmic);
1169     if (status) return status;
1170 
1171     // allocate segments
1172     btstack_linked_list_t free_segments = NULL;
1173     bool ok = mesh_segmented_allocate_segments( &free_segments, access_pdu_len);
1174     if (!ok) return 1;
1175     // store control pdu
1176     mesh_segmented_store_payload(access_pdu_data, access_pdu_len, &free_segments, &upper_pdu->segments);
1177     upper_pdu->len = access_pdu_len;
1178     return 0;
1179 }
1180 
1181 
1182 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1183                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1184     switch (pdu->pdu_type){
1185         case MESH_PDU_TYPE_ACCESS:
1186             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_access_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
1187         default:
1188             btstack_assert(false);
1189             return 1;
1190     }
1191 }
1192 
1193 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1194                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
1195                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1196     switch (pdu->pdu_type){
1197         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1198         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1199             return mesh_upper_transport_setup_upper_access_pdu((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1200                                                                appkey_index, ttl, src, dest, szmic, access_pdu_data,
1201                                                                access_pdu_len);
1202         default:
1203             btstack_assert(false);
1204             return 1;
1205     }
1206 }
1207 
1208 void mesh_upper_transport_register_access_message_handler(void (*callback)(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu)) {
1209     mesh_access_message_handler = callback;
1210 }
1211 
1212 void mesh_upper_transport_register_control_message_handler(void (*callback)(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu)){
1213     mesh_control_message_handler = callback;
1214 }
1215 
1216 void mesh_upper_transport_init(){
1217     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1218 }
1219