xref: /btstack/src/mesh/mesh_upper_transport.c (revision c9921182ab4b1f83e3e5c671446dca5ffdf45b90)
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.
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33  * Please inquire about commercial licensing options at
34  * [email protected]
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36  */
37 
38 #include <stdarg.h>
39 #include "btstack_tlv.h"
40 #include "mesh/mesh_foundation.h"
41 #include "mesh_upper_transport.h"
42 #include "mesh/mesh.h"
43 #include "mesh/mesh_proxy.h"
44 #include "mesh/mesh_node.h"
45 
46 #define BTSTACK_FILE__ "mesh_upper_transport.c"
47 
48 #include "mesh/mesh_upper_transport.h"
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 
54 #include "btstack_util.h"
55 #include "btstack_memory.h"
56 #include "btstack_debug.h"
57 #include "btstack_bool.h"
58 
59 #include "mesh/beacon.h"
60 #include "mesh/mesh_iv_index_seq_number.h"
61 #include "mesh/mesh_keys.h"
62 #include "mesh/mesh_lower_transport.h"
63 #include "mesh/mesh_peer.h"
64 #include "mesh/mesh_virtual_addresses.h"
65 
66 // TODO: extract mesh_pdu functions into lower transport or network
67 #include "mesh/mesh_access.h"
68 
69 // MESH_ACCESS_MESH_NETWORK_PAYLOAD_MAX (384) / MESH_NETWORK_PAYLOAD_MAX (29) = 13.24.. < 14
70 #define MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS (14)
71 
72 // combined key x address iterator for upper transport decryption
73 
74 typedef struct {
75     // state
76     mesh_transport_key_iterator_t  key_it;
77     mesh_virtual_address_iterator_t address_it;
78     // elements
79     const mesh_transport_key_t *   key;
80     const mesh_virtual_address_t * address;
81     // address - might be virtual
82     uint16_t dst;
83     // key info
84 } mesh_transport_key_and_virtual_address_iterator_t;
85 
86 static void mesh_upper_transport_run(void);
87 static void mesh_upper_transport_schedule_send_requests(void);
88 static void mesh_upper_transport_validate_access_message(void);
89 
90 // upper transport callbacks - in access layer
91 static void (*mesh_access_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
92 static void (*mesh_control_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
93 
94 //
95 static int crypto_active;
96 static uint8_t application_nonce[13];
97 static btstack_crypto_ccm_t ccm;
98 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
99 
100 // incoming segmented (mesh_segmented_pdu_t) or unsegmented (network_pdu_t)
101 static mesh_pdu_t *          incoming_access_encrypted;
102 
103 // multi-purpose union: segmented control reassembly, decrypted access pdu
104 static union {
105     mesh_control_pdu_t    control;
106     mesh_access_pdu_t     access;
107 } incoming_pdu_singleton;
108 
109 // pointer to incoming_pdu_singleton.access
110 static mesh_access_pdu_t *   incoming_access_decrypted;
111 
112 // pointer to incoming_pdu_singleton.access
113 static mesh_control_pdu_t *  incoming_control_pdu;
114 
115 // incoming incoming_access_decrypted ready to be deliverd
116 static bool incoming_access_pdu_ready;
117 
118 // incoming unsegmented (network) and segmented (transport) control and access messages
119 static btstack_linked_list_t upper_transport_incoming;
120 
121 
122 // outgoing unsegmented and segmented control and access messages
123 static btstack_linked_list_t upper_transport_outgoing;
124 
125 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
126 static btstack_linked_list_t upper_transport_outgoing_active;
127 
128 // outgoing send requests
129 static btstack_linked_list_t upper_transport_send_requests;
130 
131 // message builder buffers
132 static mesh_upper_transport_pdu_t * message_builder_reserved_upper_pdu;
133 static uint8_t message_builder_num_network_pdus_reserved;
134 static btstack_linked_list_t message_builder_reserved_network_pdus;
135 
136 // requets network pdus for outgoing send requests and outgoing run
137 static bool upper_transport_need_pdu_for_send_requests;
138 static bool upper_transport_need_pdu_for_run_outgoing;
139 
140 // TODO: higher layer define used for assert
141 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
142 
143 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
144     printf("%-20s ", name);
145     printf_hexdump(data, len);
146 }
147 // static void mesh_print_x(const char * name, uint32_t value){
148 //     printf("%20s: 0x%x", name, (int) value);
149 // }
150 
151 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
152                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
153                                                                  uint8_t aid) {
154     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
155     // config
156     it->dst   = dst;
157     // init elements
158     it->key     = NULL;
159     it->address = NULL;
160     // init element iterators
161     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
162     // init address iterator
163     if (mesh_network_address_virtual(it->dst)){
164         mesh_virtual_address_iterator_init(&it->address_it, dst);
165         // get first key
166         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
167             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
168         }
169     }
170 }
171 
172 // cartesian product: keys x addressses
173 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
174     if (mesh_network_address_virtual(it->dst)) {
175         // find next valid entry
176         while (true){
177             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
178             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
179             // get next key
180             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
181             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
182         }
183     } else {
184         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
185     }
186 }
187 
188 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
189     if (mesh_network_address_virtual(it->dst)) {
190         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
191     } else {
192         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
193     }
194 }
195 
196 // UPPER TRANSPORT
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         uint8_t offset = 0;
206         while (offset < segment->len){
207             uint8_t seg_o = segment->data[offset++];
208             (void) memcpy(&buffer[seg_o * segment_len], &segment->data[offset], segment_len);
209             offset += segment_len;
210         }
211     }
212 }
213 
214 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
215     // assemble payload
216     btstack_linked_list_iterator_t it;
217     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
218     uint16_t offset = 0;
219     while (btstack_linked_list_iterator_has_next(&it)) {
220         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
221         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
222         btstack_assert((offset + segment->len) <= buffer_len);
223         (void) memcpy(&buffer[offset], segment->data, segment->len);
224         offset += segment->len;
225     }
226     return offset;
227 }
228 
229 // store payload in provided list of network pdus
230 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){
231     uint16_t payload_offset = 0;
232     uint16_t bytes_current_segment = 0;
233     mesh_network_pdu_t * network_pdu = NULL;
234     while (payload_offset < payload_len){
235         if (bytes_current_segment == 0){
236             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
237             btstack_assert(network_pdu != NULL);
238             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
239             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
240         }
241         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
242         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
243         bytes_current_segment -= bytes_to_copy;
244         network_pdu->len += bytes_to_copy;
245         payload_offset += bytes_to_copy;
246     }
247 }
248 
249 // tries allocate and add enough segments to store payload of given size
250 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
251     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
252     while (storage_size < payload_len){
253         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
254         if (network_pdu == NULL) break;
255         storage_size += MESH_NETWORK_PAYLOAD_MAX;
256         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
257     }
258     return (storage_size >= payload_len);
259 }
260 
261 // stub lower transport
262 
263 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
264     printf("List: %s:\n", name);
265     btstack_linked_list_iterator_t it;
266     btstack_linked_list_iterator_init(&it, list);
267     while (btstack_linked_list_iterator_has_next(&it)){
268         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
269         printf("- %p\n", pdu);
270         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
271     }
272 }
273 
274 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
275     while (!btstack_linked_list_empty(list)){
276         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
277     }
278 }
279 
280 void mesh_upper_transport_dump(void){
281     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
282 }
283 
284 void mesh_upper_transport_reset(void){
285     crypto_active = 0;
286     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
287 }
288 
289 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
290     // Device Key is fixed
291     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
292         return mesh_transport_key_get(appkey_index);
293     }
294 
295     // Get key refresh state from subnet
296     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
297     if (subnet == NULL) return NULL;
298 
299     // identify old and new app keys for given appkey_index
300     mesh_transport_key_t * old_key = NULL;
301     mesh_transport_key_t * new_key = NULL;
302     mesh_transport_key_iterator_t it;
303     mesh_transport_key_iterator_init(&it, netkey_index);
304     while (mesh_transport_key_iterator_has_more(&it)){
305         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
306         if (transport_key->appkey_index != appkey_index) continue;
307         if (transport_key->old_key == 0) {
308             new_key = transport_key;
309         } else {
310             old_key = transport_key;
311         }
312     }
313 
314     // if no key is marked as old, just use the current one
315     if (old_key == NULL) return new_key;
316 
317     // use new key if it exists in phase two
318     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
319         return new_key;
320     } else {
321         return old_key;
322     }
323 }
324 
325 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
326     // get IV Index and IVI
327     uint32_t iv_index = mesh_get_iv_index();
328     int ivi = ivi_nid >> 7;
329 
330     // if least significant bit differs, use previous IV Index
331     if ((iv_index & 1 ) ^ ivi){
332         iv_index--;
333     }
334     return iv_index;
335 }
336 
337 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
338     mesh_access_pdu_t * access_pdu;
339     mesh_upper_transport_pdu_t * upper_pdu;
340     switch (pdu->pdu_type){
341         case MESH_PDU_TYPE_ACCESS:
342             access_pdu = (mesh_access_pdu_t *) pdu;
343             nonce[1] = ((access_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
344             big_endian_store_24(nonce, 2, access_pdu->seq);
345             big_endian_store_16(nonce, 5, access_pdu->src);
346             big_endian_store_16(nonce, 7, access_pdu->dst);
347             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
348             break;
349         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
350         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
351             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
352             nonce[1] = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
353             // 'network header'
354             big_endian_store_24(nonce, 2, upper_pdu->seq);
355             big_endian_store_16(nonce, 5, upper_pdu->src);
356             big_endian_store_16(nonce, 7, upper_pdu->dst);
357             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
358             break;
359         default:
360             btstack_assert(0);
361             break;
362     }
363 }
364 
365 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
366     nonce[0] = 0x01;
367     transport_segmented_setup_nonce(nonce, pdu);
368     mesh_print_hex("AppNonce", nonce, 13);
369 }
370 
371 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
372     nonce[0] = 0x02;
373     transport_segmented_setup_nonce(nonce, pdu);
374     mesh_print_hex("DeviceNonce", nonce, 13);
375 }
376 
377 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
378     crypto_active = 0;
379     btstack_assert((access_pdu->ctl_ttl & 0x80) == 0);
380     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
381     incoming_access_encrypted = NULL;
382     incoming_access_decrypted = NULL;
383     mesh_upper_transport_run();
384 }
385 
386 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
387     UNUSED(control_pdu);
388     crypto_active = 0;
389     incoming_control_pdu = NULL;
390     mesh_upper_transport_run();
391 }
392 
393 static void mesh_upper_transport_network_pdu_freed(void){
394     // call both while prioritizing run outgoing
395     // both functions will trigger request for network pdu if needed
396     if (upper_transport_need_pdu_for_run_outgoing){
397         upper_transport_need_pdu_for_run_outgoing = false;
398         mesh_upper_transport_run();
399     }
400     if (upper_transport_need_pdu_for_send_requests){
401         upper_transport_need_pdu_for_send_requests = false;
402         mesh_upper_transport_schedule_send_requests();
403     }
404 }
405 
406 static void mesh_upper_transport_need_pdu_for_send_requests(void) {
407     bool waiting = upper_transport_need_pdu_for_send_requests || upper_transport_need_pdu_for_run_outgoing;
408     upper_transport_need_pdu_for_send_requests = true;
409     if (waiting == false) {
410         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_network_pdu_freed);
411     }
412 }
413 static void mesh_upper_transport_need_pdu_for_run_outgoing(void) {
414     bool waiting = upper_transport_need_pdu_for_send_requests || upper_transport_need_pdu_for_run_outgoing;
415     upper_transport_need_pdu_for_run_outgoing = true;
416     if (waiting == false) {
417         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_network_pdu_freed);
418     }
419 }
420 
421 static void mesh_upper_transport_deliver_access_message(void) {
422     incoming_access_pdu_ready = false;
423     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t *) incoming_access_decrypted);
424 }
425 
426 static bool mesh_upper_transport_send_requests_pending(void){
427     if (incoming_access_pdu_ready) {
428         return true;
429     }
430     return btstack_linked_list_empty(&upper_transport_send_requests) == false;
431 }
432 
433 static void mesh_upper_transport_schedule_send_requests(void){
434 
435     while (mesh_upper_transport_send_requests_pending()){
436 
437         // get ready
438         bool message_builder_ready = mesh_upper_transport_message_reserve();
439 
440         if (message_builder_ready == false){
441             // waiting for free upper pdu, we will get called again on pdu free
442             if (message_builder_reserved_upper_pdu == false){
443                 return;
444             }
445             // request callback on network pdu free
446             mesh_upper_transport_need_pdu_for_send_requests();
447             return;
448         }
449 
450         // process send requests
451 
452         // incoming access pdu
453         if (incoming_access_pdu_ready){
454             // message builder ready = one outgoing pdu is guaranteed, deliver access pdu
455             mesh_upper_transport_deliver_access_message();
456             continue;
457         }
458 
459         // regular send request
460         btstack_context_callback_registration_t * send_request = (btstack_context_callback_registration_t *) btstack_linked_list_pop(&upper_transport_send_requests);
461         btstack_assert(send_request != NULL);
462         (*send_request->callback)(send_request->context);
463     }
464 }
465 
466 void mesh_upper_transport_request_to_send(btstack_context_callback_registration_t * request){
467     btstack_linked_list_add_tail(&upper_transport_send_requests, (btstack_linked_item_t *) request);
468     mesh_upper_transport_schedule_send_requests();
469 }
470 
471 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
472     UNUSED(arg);
473 
474     uint8_t transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
475     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
476     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
477 
478     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
479 
480     // store TransMIC
481     uint8_t trans_mic[8];
482     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
483     mesh_print_hex("TransMIC", trans_mic, transmic_len);
484 
485     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transmic_len) == 0){
486         printf("TransMIC matches\n");
487 
488         // remove TransMIC from payload
489         incoming_access_decrypted->len -= transmic_len;
490 
491         // if virtual address, update dst to pseudo_dst
492         if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
493             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
494         }
495 
496         // pass to upper layer
497         incoming_access_pdu_ready = true;
498         mesh_upper_transport_schedule_send_requests();
499 
500     } else {
501         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
502         if (akf){
503             printf("TransMIC does not match, try next key\n");
504             mesh_upper_transport_validate_access_message();
505         } else {
506             printf("TransMIC does not match device key, done\n");
507             // done
508             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
509         }
510     }
511 }
512 
513 static void mesh_upper_transport_validate_access_message_digest(void * arg){
514     UNUSED(arg);
515     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
516     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - transmic_len;
517     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
518 
519     mesh_network_pdu_t * unsegmented_pdu = NULL;
520     mesh_segmented_pdu_t * segmented_pdu = NULL;
521     switch (incoming_access_encrypted->pdu_type){
522         case MESH_PDU_TYPE_SEGMENTED:
523             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
524             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
525             mesh_print_hex("Encrypted Payload:", upper_transport_pdu_data_out, upper_transport_pdu_len);
526             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
527                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
528             break;
529         case MESH_PDU_TYPE_UNSEGMENTED:
530             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
531             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
532             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
533                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
534             break;
535         default:
536             btstack_assert(false);
537             break;
538     }
539 
540 }
541 
542 static void mesh_upper_transport_validate_access_message(void){
543     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
544     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
545     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - transmic_len;
546 
547     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
548         printf("No valid transport key found\n");
549         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
550         return;
551     }
552     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
553     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
554 
555     if (message_key->akf){
556         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
557     } else {
558         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
559     }
560 
561     // store application / device key index
562     mesh_print_hex("AppOrDevKey", message_key->key, 16);
563     incoming_access_decrypted->appkey_index = message_key->appkey_index;
564 
565     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
566 
567     // decrypt ccm
568     crypto_active = 1;
569     uint16_t aad_len  = 0;
570     if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
571         aad_len  = 16;
572     }
573     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transmic_len);
574 
575     if (aad_len){
576         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
577                                   &mesh_upper_transport_validate_access_message_digest, NULL);
578     } else {
579         mesh_upper_transport_validate_access_message_digest(NULL);
580     }
581 }
582 
583 static void mesh_upper_transport_process_access_message(void){
584     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
585     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
586     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
587     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
588 
589     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
590     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
591 
592     printf("AKF: %u\n",   akf);
593     printf("AID: %02x\n", aid);
594 
595     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, incoming_access_decrypted->dst,
596                                                          incoming_access_decrypted->netkey_index, akf, aid);
597     mesh_upper_transport_validate_access_message();
598 }
599 
600 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
601     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
602     mesh_upper_transport_run();
603 }
604 
605 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
606 
607     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
608     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
609 
610     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
611     btstack_linked_list_t free_segments = segmented_pdu->segments;
612     segmented_pdu->segments = NULL;
613     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
614 
615     // copy meta
616     segmented_pdu->len = upper_pdu->len;
617     segmented_pdu->netkey_index = upper_pdu->netkey_index;
618     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
619     segmented_pdu->flags = upper_pdu->flags;
620 
621     // setup segmented_pdu header
622     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
623     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
624     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
625     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
626     segmented_pdu->seq = upper_pdu->seq;
627     segmented_pdu->src = upper_pdu->src;
628     segmented_pdu->dst = upper_pdu->dst;
629 
630     // queue up
631     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
632     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
633 
634     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
635 }
636 
637 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
638 
639     // provide segment
640     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
641 
642     // setup network pdu
643     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
644     network_pdu->data[0] = upper_pdu->ivi_nid;
645     network_pdu->data[1] = upper_pdu->ctl_ttl;
646     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
647     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
648     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
649     network_pdu->netkey_index = upper_pdu->netkey_index;
650 
651     // setup access message
652     network_pdu->data[9] = upper_pdu->akf_aid_control;
653     btstack_assert(upper_pdu->len < 15);
654     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
655     network_pdu->len = 10 + upper_pdu->len;
656     network_pdu->flags = 0;
657 
658     // queue up
659     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
660 
661     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
662 }
663 
664 static void mesh_upper_transport_send_access_ccm(void * arg){
665     crypto_active = 0;
666 
667     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
668     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
669     // store TransMIC
670     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
671     uint8_t transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
672     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], transmic_len);
673     upper_pdu->len += transmic_len;
674     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
675     switch (upper_pdu->pdu_header.pdu_type){
676         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
677             mesh_upper_transport_send_access_unsegmented(upper_pdu);
678             break;
679         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
680             mesh_upper_transport_send_access_segmented(upper_pdu);
681             break;
682         default:
683             btstack_assert(false);
684     }
685 }
686 
687 static void mesh_upper_transport_send_access_digest(void *arg){
688     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
689     uint16_t  access_pdu_len  = upper_pdu->len;
690     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
691                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
692 }
693 
694 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
695 
696     // if dst is virtual address, lookup label uuid and hash
697     uint16_t aad_len = 0;
698     mesh_virtual_address_t * virtual_address = NULL;
699     if (mesh_network_address_virtual(upper_pdu->dst)){
700         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
701         if (!virtual_address){
702             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
703             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
704             return;
705         }
706         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
707         // printf_hexdump(virtual_address->label_uuid, 16);
708         aad_len = 16;
709         upper_pdu->dst = virtual_address->hash;
710     }
711 
712     // get app or device key
713     uint16_t appkey_index = upper_pdu->appkey_index;
714     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
715     if (appkey == NULL){
716         printf("AppKey %04x not found, drop message\n", appkey_index);
717         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
718         return;
719     }
720 
721     // reserve slot
722     mesh_lower_transport_reserve_slot();
723 
724     // reserve one sequence number, which is also used to encrypt access payload
725     uint32_t seq = mesh_sequence_number_next();
726     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
727     upper_pdu->seq = seq;
728 
729     // also reserves crypto_buffer
730     crypto_active = 1;
731 
732     // flatten segmented pdu into crypto buffer
733     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
734     btstack_assert(payload_len == upper_pdu->len);
735     UNUSED(payload_len);
736 
737     // Dump PDU
738     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
739     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
740 
741     // setup nonce - uses dst, so after pseudo address translation
742     if (appkey_index == MESH_DEVICE_KEY_INDEX){
743         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
744     } else {
745         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
746     }
747 
748     // Dump key
749     mesh_print_hex("AppOrDevKey", appkey->key, 16);
750 
751     // encrypt ccm
752     uint8_t   transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
753     uint16_t  access_pdu_len  = upper_pdu->len;
754     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
755     if (virtual_address){
756         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
757         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
758                                   &mesh_upper_transport_send_access_digest, upper_pdu);
759     } else {
760         mesh_upper_transport_send_access_digest(upper_pdu);
761     }
762 }
763 
764 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
765     // reserve slot
766     mesh_lower_transport_reserve_slot();
767     // reserve sequence number
768     uint32_t seq = mesh_sequence_number_next();
769     mesh_network_pdu_set_seq(network_pdu, seq);
770     // Dump PDU
771     uint8_t opcode = network_pdu->data[9];
772     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
773     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
774 
775     // send
776      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
777 }
778 
779 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
780     // reserve slot
781     mesh_lower_transport_reserve_slot();
782     // reserve sequence number
783     uint32_t seq = mesh_sequence_number_next();
784     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
785     upper_pdu->seq = seq;
786     // Dump PDU
787     // uint8_t opcode = upper_pdu->data[0];
788     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
789     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
790     // send
791     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
792     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
793 
794     // lend segments to lower transport pdu
795     segmented_pdu->segments = upper_pdu->segments;
796     upper_pdu->segments = NULL;
797 
798     // copy meta
799     segmented_pdu->len = upper_pdu->len;
800     segmented_pdu->netkey_index = upper_pdu->netkey_index;
801     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
802     segmented_pdu->flags = upper_pdu->flags;
803 
804     btstack_assert((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) == 0);
805 
806     // setup segmented_pdu header
807     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
808     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
809     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
810     segmented_pdu->seq = upper_pdu->seq;
811     segmented_pdu->src = upper_pdu->src;
812     segmented_pdu->dst = upper_pdu->dst;
813 
814     // queue up
815     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
816     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
817 
818     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
819 }
820 
821 static void mesh_upper_transport_run(void){
822 
823     while(!btstack_linked_list_empty(&upper_transport_incoming)){
824 
825         if (crypto_active) return;
826 
827         // get next message
828         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
829         mesh_network_pdu_t   * network_pdu;
830         mesh_segmented_pdu_t   * segmented_pdu;
831         switch (pdu->pdu_type){
832             case MESH_PDU_TYPE_UNSEGMENTED:
833                 network_pdu = (mesh_network_pdu_t *) pdu;
834                 // control?
835                 if (mesh_network_control(network_pdu)) {
836 
837                     incoming_control_pdu =  &incoming_pdu_singleton.control;
838                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
839                     incoming_control_pdu->len =  network_pdu->len;
840                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
841 
842                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
843 
844                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
845                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
846                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
847 
848                     // copy meta data into encrypted pdu buffer
849                     incoming_control_pdu->ivi_nid = network_pdu->data[0];
850                     incoming_control_pdu->ctl_ttl = network_pdu->data[1];
851                     incoming_control_pdu->seq = big_endian_read_24(network_pdu->data, 2);
852                     incoming_control_pdu->src = big_endian_read_16(network_pdu->data, 5);
853                     incoming_control_pdu->dst = big_endian_read_16(network_pdu->data, 7);
854 
855                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
856 
857                     // free mesh message
858                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
859 
860                     btstack_assert(mesh_control_message_handler != NULL);
861                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t*) incoming_control_pdu);
862 
863                 } else {
864 
865                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
866 
867                     incoming_access_decrypted = &incoming_pdu_singleton.access;
868                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
869                     incoming_access_decrypted->flags = 0;
870                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
871                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
872                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
873                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
874                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
875                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
876                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
877                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
878 
879                     mesh_upper_transport_process_access_message();
880                 }
881                 break;
882             case MESH_PDU_TYPE_SEGMENTED:
883                 segmented_pdu = (mesh_segmented_pdu_t *) pdu;
884                 uint8_t ctl = segmented_pdu->ctl_ttl >> 7;
885                 if (ctl){
886                     incoming_control_pdu=  &incoming_pdu_singleton.control;
887                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
888 
889                     // flatten
890                     mesh_segmented_pdu_flatten(&segmented_pdu->segments, 8, incoming_control_pdu->data);
891 
892                     // copy meta data into encrypted pdu buffer
893                     incoming_control_pdu->flags = 0;
894                     incoming_control_pdu->len =  segmented_pdu->len;
895                     incoming_control_pdu->netkey_index =  segmented_pdu->netkey_index;
896                     incoming_control_pdu->akf_aid_control = segmented_pdu->akf_aid_control;
897                     incoming_control_pdu->ivi_nid = segmented_pdu->ivi_nid;
898                     incoming_control_pdu->ctl_ttl = segmented_pdu->ctl_ttl;
899                     incoming_control_pdu->seq = segmented_pdu->seq;
900                     incoming_control_pdu->src = segmented_pdu->src;
901                     incoming_control_pdu->dst = segmented_pdu->dst;
902 
903                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
904 
905                     // free mesh message
906                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)segmented_pdu);
907 
908                     btstack_assert(mesh_control_message_handler != NULL);
909                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t*) incoming_control_pdu);
910 
911                 } else {
912 
913                     incoming_access_encrypted = (mesh_pdu_t *) segmented_pdu;
914 
915                     incoming_access_decrypted = &incoming_pdu_singleton.access;
916                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
917                     incoming_access_decrypted->flags = segmented_pdu->flags;
918                     incoming_access_decrypted->len =  segmented_pdu->len;
919                     incoming_access_decrypted->netkey_index = segmented_pdu->netkey_index;
920                     incoming_access_decrypted->akf_aid_control =  segmented_pdu->akf_aid_control;
921                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
922                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
923                     incoming_access_decrypted->seq = segmented_pdu->seq;
924                     incoming_access_decrypted->src = segmented_pdu->src;
925                     incoming_access_decrypted->dst = segmented_pdu->dst;
926 
927                     mesh_upper_transport_process_access_message();
928                 }
929                 break;
930             default:
931                 btstack_assert(0);
932                 break;
933         }
934     }
935 
936     btstack_linked_list_iterator_t it;
937     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing);
938     while (btstack_linked_list_iterator_has_next(&it)){
939 
940         if (crypto_active) break;
941 
942         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
943         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == false) {
944             // skip pdu for now
945             continue;
946         }
947 
948         mesh_upper_transport_pdu_t * upper_pdu;
949         mesh_segmented_pdu_t * segmented_pdu;
950         uint8_t transmic_len;
951         bool ok;
952         bool abort_outgoing_loop = false;
953 
954         switch (pdu->pdu_type){
955             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
956                 // control pdus can go through directly
957                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
958                 btstack_linked_list_iterator_remove(&it);
959                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
960                 break;
961             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
962                 // control pdus can go through directly
963                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
964                 btstack_linked_list_iterator_remove(&it);
965                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
966                 break;
967             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
968                 // segmented access pdus required a mesh-segmented-pdu
969                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
970                 if (upper_pdu->lower_pdu == NULL){
971                     upper_pdu->lower_pdu  = (mesh_pdu_t *) btstack_memory_mesh_segmented_pdu_get();
972                 }
973                 if (upper_pdu->lower_pdu == NULL){
974                     mesh_upper_transport_need_pdu_for_run_outgoing();
975                     abort_outgoing_loop = true;
976                     break;
977                 }
978                 segmented_pdu = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
979                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
980                 // and a mesh-network-pdu for each segment in upper pdu
981                 transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
982                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + transmic_len);
983                 if (!ok) {
984                     abort_outgoing_loop = true;
985                     break;
986                 }
987                 // all buffers available, get started
988                 btstack_linked_list_iterator_remove(&it);
989                 mesh_upper_transport_send_access(upper_pdu);
990                 break;
991             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
992                 // unsegmented access pdus require a single mesh-network-dpu
993                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
994                 if (upper_pdu->lower_pdu == NULL){
995                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
996                 }
997                 if (upper_pdu->lower_pdu == NULL) {
998                     mesh_upper_transport_need_pdu_for_run_outgoing();
999                     abort_outgoing_loop = true;
1000                     break;
1001                 }
1002                 btstack_linked_list_iterator_remove(&it);
1003                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
1004                 break;
1005             default:
1006                 btstack_assert(false);
1007                 break;
1008         }
1009         if (abort_outgoing_loop) {
1010             break;
1011         }
1012     }
1013 }
1014 
1015 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_and_remove_pdu_for_lower(mesh_pdu_t * pdu_to_find){
1016     btstack_linked_list_iterator_t it;
1017     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
1018     mesh_upper_transport_pdu_t * upper_pdu;
1019     while (btstack_linked_list_iterator_has_next(&it)){
1020         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
1021         switch (mesh_pdu->pdu_type){
1022             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1023             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1024             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1025                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
1026                 if (upper_pdu->lower_pdu == pdu_to_find){
1027                     btstack_linked_list_iterator_remove(&it);
1028                     return upper_pdu;
1029                 }
1030                 break;
1031             default:
1032                 break;
1033         }
1034     }
1035     return NULL;
1036 }
1037 
1038 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
1039     mesh_upper_transport_pdu_t * upper_pdu;
1040     mesh_segmented_pdu_t * segmented_pdu;
1041     switch (callback_type){
1042         case MESH_TRANSPORT_PDU_RECEIVED:
1043             mesh_upper_transport_message_received(pdu);
1044             break;
1045         case MESH_TRANSPORT_PDU_SENT:
1046             switch (pdu->pdu_type){
1047                 case MESH_PDU_TYPE_SEGMENTED:
1048                     // try to find in outgoing active
1049                     upper_pdu = mesh_upper_transport_find_and_remove_pdu_for_lower(pdu);
1050                     btstack_assert(upper_pdu != NULL);
1051                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
1052                     // free chunks
1053                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
1054                         mesh_network_pdu_t * chunk_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
1055                         mesh_network_pdu_free(chunk_pdu);
1056                     }
1057                     // free segmented pdu
1058                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
1059                     upper_pdu->lower_pdu = NULL;
1060                     switch (upper_pdu->pdu_header.pdu_type){
1061                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1062                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1063                             break;
1064                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1065                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1066                             break;
1067                         default:
1068                             btstack_assert(false);
1069                             break;
1070                     }
1071                     break;
1072                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1073                     // find corresponding upper transport pdu and free single segment
1074                     upper_pdu = mesh_upper_transport_find_and_remove_pdu_for_lower(pdu);
1075                     btstack_assert(upper_pdu != NULL);
1076                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
1077                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
1078                     upper_pdu->lower_pdu = NULL;
1079                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
1080                     break;
1081                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1082                     mesh_access_message_handler(callback_type, status, pdu);
1083                     break;
1084                 default:
1085                     btstack_assert(false);
1086                     break;
1087             }
1088             mesh_upper_transport_run();
1089             break;
1090         default:
1091             break;
1092     }
1093 }
1094 
1095 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
1096     btstack_assert(pdu != NULL);
1097     mesh_network_pdu_t   * network_pdu;
1098     mesh_segmented_pdu_t   * message_pdu;
1099     mesh_upper_transport_pdu_t * upper_pdu;
1100     switch (pdu->pdu_type) {
1101         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1102         case MESH_PDU_TYPE_NETWORK:
1103             network_pdu = (mesh_network_pdu_t *) pdu;
1104             mesh_network_pdu_free(network_pdu);
1105             break;
1106         case MESH_PDU_TYPE_SEGMENTED:
1107             message_pdu = (mesh_segmented_pdu_t *) pdu;
1108             mesh_segmented_pdu_free(message_pdu);
1109             break;
1110         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1111         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1112         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1113             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1114             while (upper_pdu->segments) {
1115                 mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&upper_pdu->segments);
1116                 mesh_network_pdu_free(segment);
1117             }
1118             btstack_memory_mesh_upper_transport_pdu_free(upper_pdu);
1119             // check if send request can be handled now
1120             mesh_upper_transport_schedule_send_requests();
1121             break;
1122         default:
1123             btstack_assert(false);
1124             break;
1125     }
1126 }
1127 
1128 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1129     crypto_active = 0;
1130     switch (pdu->pdu_type){
1131         case MESH_PDU_TYPE_ACCESS:
1132             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1133         case MESH_PDU_TYPE_CONTROL:
1134             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1135             break;
1136         default:
1137             btstack_assert(0);
1138             break;
1139     }
1140 }
1141 
1142 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1143     switch (pdu->pdu_type){
1144         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1145         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1146             break;
1147         default:
1148             btstack_assert(false);
1149             break;
1150     }
1151 
1152     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1153 
1154     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1155     mesh_upper_transport_run();
1156 }
1157 
1158 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1159     switch (pdu->pdu_type){
1160         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1161             break;
1162         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1163             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1164             break;
1165         default:
1166             btstack_assert(false);
1167             break;
1168     }
1169 
1170     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1171     mesh_upper_transport_run();
1172 }
1173 
1174 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,
1175                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1176 
1177     btstack_assert(network_pdu != NULL);
1178     btstack_assert(control_pdu_len <= 11);
1179 
1180     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1181     if (!network_key) return 1;
1182 
1183     uint8_t transport_pdu_data[12];
1184     transport_pdu_data[0] = opcode;
1185     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1186     uint16_t transport_pdu_len = control_pdu_len + 1;
1187 
1188     // setup network_pdu
1189     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL;
1190     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1191 
1192     return 0;
1193 }
1194 
1195 uint8_t mesh_upper_transport_setup_segmented_control_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode){
1196 
1197     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1198     if (!network_key) return 1;
1199 
1200     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1201     upper_pdu->ctl_ttl = ttl;
1202     upper_pdu->src = src;
1203     upper_pdu->dst = dest;
1204     upper_pdu->netkey_index = netkey_index;
1205     upper_pdu->akf_aid_control = opcode;
1206     return 0;
1207 }
1208 
1209 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1210                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1211 
1212     // get app or device key
1213     const mesh_transport_key_t *appkey;
1214     appkey = mesh_transport_key_get(appkey_index);
1215     if (appkey == NULL) {
1216         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1217         return 1;
1218     }
1219     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1220 
1221     // lookup network by netkey_index
1222     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1223     if (!network_key) return 1;
1224     if (network_key == NULL) {
1225         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1226         return 1;
1227     }
1228 
1229     // store in transport pdu
1230     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1231     upper_pdu->ctl_ttl = ttl;
1232     upper_pdu->src = src;
1233     upper_pdu->dst = dest;
1234     upper_pdu->netkey_index = netkey_index;
1235     upper_pdu->appkey_index = appkey_index;
1236     upper_pdu->akf_aid_control = akf_aid;
1237     if (szmic) {
1238         upper_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1239     }
1240     return 0;
1241 }
1242 
1243 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1244                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1245     switch (pdu->pdu_type){
1246         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1247         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1248             return mesh_upper_transport_setup_upper_access_pdu_header((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1249                                                                appkey_index, ttl, src, dest, szmic);
1250         default:
1251             btstack_assert(false);
1252             return 1;
1253     }
1254 }
1255 
1256 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)) {
1257     mesh_access_message_handler = callback;
1258 }
1259 
1260 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)){
1261     mesh_control_message_handler = callback;
1262 }
1263 
1264 void mesh_upper_transport_init(){
1265     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1266 }
1267 
1268 bool mesh_upper_transport_message_reserve(void){
1269     if (message_builder_reserved_upper_pdu == NULL){
1270         message_builder_reserved_upper_pdu = btstack_memory_mesh_upper_transport_pdu_get();
1271     }
1272     if (message_builder_reserved_upper_pdu == NULL){
1273         return false;
1274     }
1275     while (message_builder_num_network_pdus_reserved < MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS){
1276         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1277         if (network_pdu == NULL){
1278             return false;
1279         }
1280         btstack_linked_list_add(&message_builder_reserved_network_pdus, (btstack_linked_item_t *) network_pdu);
1281         message_builder_num_network_pdus_reserved++;
1282     }
1283     return true;
1284 }
1285 
1286 void mesh_upper_transport_message_init(mesh_upper_transport_builder_t * builder, mesh_pdu_type_t pdu_type) {
1287     btstack_assert(builder != NULL);
1288 
1289     // use reserved buffer if available
1290     if (message_builder_reserved_upper_pdu != NULL){
1291         builder->pdu = message_builder_reserved_upper_pdu;
1292         message_builder_reserved_upper_pdu = NULL;
1293     } else {
1294         builder->pdu = btstack_memory_mesh_upper_transport_pdu_get();
1295     }
1296     if (!builder->pdu) return;
1297 
1298     builder->segment = NULL;
1299     builder->pdu->pdu_header.pdu_type = pdu_type;
1300     builder->pdu->ack_opcode = MESH_ACCESS_OPCODE_NOT_SET;
1301 }
1302 
1303 
1304 void mesh_upper_transport_message_add_data(mesh_upper_transport_builder_t * builder, const uint8_t * data, uint16_t data_len){
1305     btstack_assert(builder != NULL);
1306 
1307     if (builder->pdu == NULL) return;
1308 
1309     builder->pdu->len += data_len;
1310 
1311     uint16_t bytes_current_segment = 0;
1312     if (builder->segment){
1313         bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX - builder->segment->len;
1314     }
1315     while (data_len > 0){
1316         if (bytes_current_segment == 0){
1317             // use reserved buffer if available
1318             if (message_builder_num_network_pdus_reserved > 0){
1319                 message_builder_num_network_pdus_reserved--;
1320                 builder->segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&message_builder_reserved_network_pdus);
1321             } else {
1322                 builder->segment = (mesh_network_pdu_t *) mesh_network_pdu_get();
1323             }
1324             if (builder->segment == NULL) {
1325                 mesh_upper_transport_pdu_free((mesh_pdu_t *) builder->pdu);
1326                 builder->pdu = NULL;
1327                 return;
1328             }
1329             btstack_linked_list_add_tail(&builder->pdu->segments, (btstack_linked_item_t *) builder->segment);
1330             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
1331         }
1332         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, data_len);
1333         (void) memcpy(&builder->segment->data[builder->segment->len], data, bytes_to_copy);
1334         builder->segment->len += bytes_to_copy;
1335         bytes_current_segment -= bytes_to_copy;
1336         data                  += bytes_to_copy;
1337         data_len              -= bytes_to_copy;
1338     }
1339 }
1340 
1341 void mesh_upper_transport_message_add_uint8(mesh_upper_transport_builder_t * builder, uint8_t value){
1342     mesh_upper_transport_message_add_data(builder, &value, 1);
1343 }
1344 
1345 void mesh_upper_transport_message_add_uint16(mesh_upper_transport_builder_t * builder, uint16_t value){
1346     uint8_t buffer[2];
1347     little_endian_store_16(buffer, 0, value);
1348     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1349 }
1350 
1351 void mesh_upper_transport_message_add_uint24(mesh_upper_transport_builder_t * builder, uint32_t value){
1352     uint8_t buffer[3];
1353     little_endian_store_24(buffer, 0, value);
1354     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1355 }
1356 
1357 void mesh_upper_transport_message_add_uint32(mesh_upper_transport_builder_t * builder, uint32_t value){
1358     uint8_t buffer[4];
1359     little_endian_store_32(buffer, 0, value);
1360     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1361 }
1362 
1363 mesh_upper_transport_pdu_t * mesh_upper_transport_message_finalize(mesh_upper_transport_builder_t * builder){
1364     return builder->pdu;
1365 }
1366