xref: /btstack/src/mesh/mesh_upper_transport.c (revision a8d51f092f1b660d0f6921369ad2bc3f9368296c)
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,
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26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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33  * Please inquire about commercial licensing options at
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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     mesh_upper_transport_reset_pdus(&upper_transport_outgoing);
288     message_builder_num_network_pdus_reserved = 0;
289     mesh_upper_transport_reset_pdus(&message_builder_reserved_network_pdus);
290     if (message_builder_reserved_upper_pdu != NULL){
291         btstack_memory_mesh_upper_transport_pdu_free(message_builder_reserved_upper_pdu);
292         message_builder_reserved_upper_pdu = NULL;
293     }
294 }
295 
296 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
297     // Device Key is fixed
298     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
299         return mesh_transport_key_get(appkey_index);
300     }
301 
302     // Get key refresh state from subnet
303     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
304     if (subnet == NULL) return NULL;
305 
306     // identify old and new app keys for given appkey_index
307     mesh_transport_key_t * old_key = NULL;
308     mesh_transport_key_t * new_key = NULL;
309     mesh_transport_key_iterator_t it;
310     mesh_transport_key_iterator_init(&it, netkey_index);
311     while (mesh_transport_key_iterator_has_more(&it)){
312         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
313         if (transport_key->appkey_index != appkey_index) continue;
314         if (transport_key->old_key == 0) {
315             new_key = transport_key;
316         } else {
317             old_key = transport_key;
318         }
319     }
320 
321     // if no key is marked as old, just use the current one
322     if (old_key == NULL) return new_key;
323 
324     // use new key if it exists in phase two
325     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
326         return new_key;
327     } else {
328         return old_key;
329     }
330 }
331 
332 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
333     // get IV Index and IVI
334     uint32_t iv_index = mesh_get_iv_index();
335     int ivi = ivi_nid >> 7;
336 
337     // if least significant bit differs, use previous IV Index
338     if ((iv_index & 1 ) ^ ivi){
339         iv_index--;
340     }
341     return iv_index;
342 }
343 
344 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
345     mesh_access_pdu_t * access_pdu;
346     mesh_upper_transport_pdu_t * upper_pdu;
347     switch (pdu->pdu_type){
348         case MESH_PDU_TYPE_ACCESS:
349             access_pdu = (mesh_access_pdu_t *) pdu;
350             nonce[1] = ((access_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
351             big_endian_store_24(nonce, 2, access_pdu->seq);
352             big_endian_store_16(nonce, 5, access_pdu->src);
353             big_endian_store_16(nonce, 7, access_pdu->dst);
354             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
355             break;
356         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
357         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
358             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
359             nonce[1] = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
360             // 'network header'
361             big_endian_store_24(nonce, 2, upper_pdu->seq);
362             big_endian_store_16(nonce, 5, upper_pdu->src);
363             big_endian_store_16(nonce, 7, upper_pdu->dst);
364             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
365             break;
366         default:
367             btstack_assert(0);
368             break;
369     }
370 }
371 
372 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
373     nonce[0] = 0x01;
374     transport_segmented_setup_nonce(nonce, pdu);
375     mesh_print_hex("AppNonce", nonce, 13);
376 }
377 
378 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
379     nonce[0] = 0x02;
380     transport_segmented_setup_nonce(nonce, pdu);
381     mesh_print_hex("DeviceNonce", nonce, 13);
382 }
383 
384 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
385     crypto_active = 0;
386     btstack_assert((access_pdu->ctl_ttl & 0x80) == 0);
387     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
388     incoming_access_encrypted = NULL;
389     incoming_access_decrypted = NULL;
390     mesh_upper_transport_run();
391 }
392 
393 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
394     UNUSED(control_pdu);
395     crypto_active = 0;
396     incoming_control_pdu = NULL;
397     mesh_upper_transport_run();
398 }
399 
400 static void mesh_upper_transport_network_pdu_freed(void){
401     // call both while prioritizing run outgoing
402     // both functions will trigger request for network pdu if needed
403     if (upper_transport_need_pdu_for_run_outgoing){
404         upper_transport_need_pdu_for_run_outgoing = false;
405         mesh_upper_transport_run();
406     }
407     if (upper_transport_need_pdu_for_send_requests){
408         upper_transport_need_pdu_for_send_requests = false;
409         mesh_upper_transport_schedule_send_requests();
410     }
411 }
412 
413 static void mesh_upper_transport_need_pdu_for_send_requests(void) {
414     bool waiting = upper_transport_need_pdu_for_send_requests || upper_transport_need_pdu_for_run_outgoing;
415     upper_transport_need_pdu_for_send_requests = true;
416     if (waiting == false) {
417         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_network_pdu_freed);
418     }
419 }
420 static void mesh_upper_transport_need_pdu_for_run_outgoing(void) {
421     bool waiting = upper_transport_need_pdu_for_send_requests || upper_transport_need_pdu_for_run_outgoing;
422     upper_transport_need_pdu_for_run_outgoing = true;
423     if (waiting == false) {
424         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_network_pdu_freed);
425     }
426 }
427 
428 static void mesh_upper_transport_deliver_access_message(void) {
429     incoming_access_pdu_ready = false;
430     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t *) incoming_access_decrypted);
431 }
432 
433 static bool mesh_upper_transport_send_requests_pending(void){
434     if (incoming_access_pdu_ready) {
435         return true;
436     }
437     return btstack_linked_list_empty(&upper_transport_send_requests) == false;
438 }
439 
440 static void mesh_upper_transport_schedule_send_requests(void){
441 
442     while (mesh_upper_transport_send_requests_pending()){
443 
444         // get ready
445         bool message_builder_ready = mesh_upper_transport_message_reserve();
446 
447         if (message_builder_ready == false){
448             // waiting for free upper pdu, we will get called again on pdu free
449             if (message_builder_reserved_upper_pdu == NULL){
450                 return;
451             }
452             // request callback on network pdu free
453             mesh_upper_transport_need_pdu_for_send_requests();
454             return;
455         }
456 
457         // process send requests
458 
459         // incoming access pdu
460         if (incoming_access_pdu_ready){
461             // message builder ready = one outgoing pdu is guaranteed, deliver access pdu
462             mesh_upper_transport_deliver_access_message();
463             continue;
464         }
465 
466         // regular send request
467         btstack_context_callback_registration_t * send_request = (btstack_context_callback_registration_t *) btstack_linked_list_pop(&upper_transport_send_requests);
468         btstack_assert(send_request != NULL);
469         (*send_request->callback)(send_request->context);
470     }
471 }
472 
473 void mesh_upper_transport_request_to_send(btstack_context_callback_registration_t * request){
474     btstack_linked_list_add_tail(&upper_transport_send_requests, (btstack_linked_item_t *) request);
475     mesh_upper_transport_schedule_send_requests();
476 }
477 
478 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
479     UNUSED(arg);
480 
481     uint8_t transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
482     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
483     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
484 
485     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
486 
487     // store TransMIC
488     uint8_t trans_mic[8];
489     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
490     mesh_print_hex("TransMIC", trans_mic, transmic_len);
491 
492     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transmic_len) == 0){
493         printf("TransMIC matches\n");
494 
495         // remove TransMIC from payload
496         incoming_access_decrypted->len -= transmic_len;
497 
498         // if virtual address, update dst to pseudo_dst
499         if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
500             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
501         }
502 
503         // pass to upper layer
504         incoming_access_pdu_ready = true;
505         mesh_upper_transport_schedule_send_requests();
506 
507     } else {
508         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
509         if (akf){
510             printf("TransMIC does not match, try next key\n");
511             mesh_upper_transport_validate_access_message();
512         } else {
513             printf("TransMIC does not match device key, done\n");
514             // done
515             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
516         }
517     }
518 }
519 
520 static void mesh_upper_transport_validate_access_message_digest(void * arg){
521     UNUSED(arg);
522     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
523     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - transmic_len;
524     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
525 
526     mesh_network_pdu_t * unsegmented_pdu = NULL;
527     mesh_segmented_pdu_t * segmented_pdu = NULL;
528     switch (incoming_access_encrypted->pdu_type){
529         case MESH_PDU_TYPE_SEGMENTED:
530             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
531             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
532             mesh_print_hex("Encrypted Payload:", upper_transport_pdu_data_out, upper_transport_pdu_len);
533             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
534                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
535             break;
536         case MESH_PDU_TYPE_UNSEGMENTED:
537             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
538             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
539             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
540                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
541             break;
542         default:
543             btstack_assert(false);
544             break;
545     }
546 
547 }
548 
549 static void mesh_upper_transport_validate_access_message(void){
550     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
551     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
552     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - transmic_len;
553 
554     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
555         printf("No valid transport key found\n");
556         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
557         return;
558     }
559     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
560     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
561 
562     if (message_key->akf){
563         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
564     } else {
565         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
566     }
567 
568     // store application / device key index
569     mesh_print_hex("AppOrDevKey", message_key->key, 16);
570     incoming_access_decrypted->appkey_index = message_key->appkey_index;
571 
572     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
573 
574     // decrypt ccm
575     crypto_active = 1;
576     uint16_t aad_len  = 0;
577     if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
578         aad_len  = 16;
579     }
580     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transmic_len);
581 
582     if (aad_len){
583         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
584                                   &mesh_upper_transport_validate_access_message_digest, NULL);
585     } else {
586         mesh_upper_transport_validate_access_message_digest(NULL);
587     }
588 }
589 
590 static void mesh_upper_transport_process_access_message(void){
591     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
592     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
593     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
594     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
595 
596     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
597     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
598 
599     printf("AKF: %u\n",   akf);
600     printf("AID: %02x\n", aid);
601 
602     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, incoming_access_decrypted->dst,
603                                                          incoming_access_decrypted->netkey_index, akf, aid);
604     mesh_upper_transport_validate_access_message();
605 }
606 
607 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
608     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
609     mesh_upper_transport_run();
610 }
611 
612 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
613 
614     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
615     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
616 
617     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
618     btstack_linked_list_t free_segments = segmented_pdu->segments;
619     segmented_pdu->segments = NULL;
620     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
621 
622     // copy meta
623     segmented_pdu->len = upper_pdu->len;
624     segmented_pdu->netkey_index = upper_pdu->netkey_index;
625     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
626     segmented_pdu->flags = upper_pdu->flags;
627 
628     // setup segmented_pdu header
629     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
630     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
631     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
632     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
633     segmented_pdu->seq = upper_pdu->seq;
634     segmented_pdu->src = upper_pdu->src;
635     segmented_pdu->dst = upper_pdu->dst;
636 
637     // queue up
638     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
639     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
640 
641     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
642 }
643 
644 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
645 
646     // provide segment
647     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
648 
649     // setup network pdu
650     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
651     network_pdu->data[0] = upper_pdu->ivi_nid;
652     network_pdu->data[1] = upper_pdu->ctl_ttl;
653     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
654     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
655     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
656     network_pdu->netkey_index = upper_pdu->netkey_index;
657 
658     // setup access message
659     network_pdu->data[9] = upper_pdu->akf_aid_control;
660     btstack_assert(upper_pdu->len < 15);
661     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
662     network_pdu->len = 10 + upper_pdu->len;
663     network_pdu->flags = 0;
664 
665     // queue up
666     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
667 
668     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
669 }
670 
671 static void mesh_upper_transport_send_access_ccm(void * arg){
672     crypto_active = 0;
673 
674     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
675     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
676     // store TransMIC
677     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
678     uint8_t transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
679     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], transmic_len);
680     upper_pdu->len += transmic_len;
681     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
682     switch (upper_pdu->pdu_header.pdu_type){
683         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
684             mesh_upper_transport_send_access_unsegmented(upper_pdu);
685             break;
686         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
687             mesh_upper_transport_send_access_segmented(upper_pdu);
688             break;
689         default:
690             btstack_assert(false);
691     }
692 }
693 
694 static void mesh_upper_transport_send_access_digest(void *arg){
695     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
696     uint16_t  access_pdu_len  = upper_pdu->len;
697     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
698                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
699 }
700 
701 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
702 
703     // if dst is virtual address, lookup label uuid and hash
704     uint16_t aad_len = 0;
705     mesh_virtual_address_t * virtual_address = NULL;
706     if (mesh_network_address_virtual(upper_pdu->dst)){
707         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
708         if (!virtual_address){
709             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
710             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
711             return;
712         }
713         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
714         // printf_hexdump(virtual_address->label_uuid, 16);
715         aad_len = 16;
716         upper_pdu->dst = virtual_address->hash;
717     }
718 
719     // get app or device key
720     uint16_t appkey_index = upper_pdu->appkey_index;
721     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
722     if (appkey == NULL){
723         printf("AppKey %04x not found, drop message\n", appkey_index);
724         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
725         return;
726     }
727 
728     // reserve slot
729     mesh_lower_transport_reserve_slot();
730 
731     // reserve one sequence number, which is also used to encrypt access payload
732     uint32_t seq = mesh_sequence_number_next();
733     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
734     upper_pdu->seq = seq;
735 
736     // also reserves crypto_buffer
737     crypto_active = 1;
738 
739     // flatten segmented pdu into crypto buffer
740     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
741     btstack_assert(payload_len == upper_pdu->len);
742     UNUSED(payload_len);
743 
744     // Dump PDU
745     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
746     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
747 
748     // setup nonce - uses dst, so after pseudo address translation
749     if (appkey_index == MESH_DEVICE_KEY_INDEX){
750         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
751     } else {
752         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
753     }
754 
755     // Dump key
756     mesh_print_hex("AppOrDevKey", appkey->key, 16);
757 
758     // encrypt ccm
759     uint8_t   transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
760     uint16_t  access_pdu_len  = upper_pdu->len;
761     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
762     if (virtual_address){
763         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
764         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
765                                   &mesh_upper_transport_send_access_digest, upper_pdu);
766     } else {
767         mesh_upper_transport_send_access_digest(upper_pdu);
768     }
769 }
770 
771 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
772     // reserve slot
773     mesh_lower_transport_reserve_slot();
774     // reserve sequence number
775     uint32_t seq = mesh_sequence_number_next();
776     mesh_network_pdu_set_seq(network_pdu, seq);
777     // Dump PDU
778     uint8_t opcode = network_pdu->data[9];
779     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
780     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
781 
782     // send
783      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
784 }
785 
786 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
787     // reserve slot
788     mesh_lower_transport_reserve_slot();
789     // reserve sequence number
790     uint32_t seq = mesh_sequence_number_next();
791     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
792     upper_pdu->seq = seq;
793     // Dump PDU
794     // uint8_t opcode = upper_pdu->data[0];
795     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
796     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
797     // send
798     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
799     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
800 
801     // lend segments to lower transport pdu
802     segmented_pdu->segments = upper_pdu->segments;
803     upper_pdu->segments = NULL;
804 
805     // copy meta
806     segmented_pdu->len = upper_pdu->len;
807     segmented_pdu->netkey_index = upper_pdu->netkey_index;
808     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
809     segmented_pdu->flags = upper_pdu->flags;
810 
811     btstack_assert((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) == 0);
812 
813     // setup segmented_pdu header
814     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
815     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
816     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
817     segmented_pdu->seq = upper_pdu->seq;
818     segmented_pdu->src = upper_pdu->src;
819     segmented_pdu->dst = upper_pdu->dst;
820 
821     // queue up
822     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
823     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
824 
825     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
826 }
827 
828 static void mesh_upper_transport_run(void){
829 
830     while(!btstack_linked_list_empty(&upper_transport_incoming)){
831 
832         if (crypto_active) return;
833 
834         // get next message
835         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
836         mesh_network_pdu_t   * network_pdu;
837         mesh_segmented_pdu_t   * segmented_pdu;
838         switch (pdu->pdu_type){
839             case MESH_PDU_TYPE_UNSEGMENTED:
840                 network_pdu = (mesh_network_pdu_t *) pdu;
841                 // control?
842                 if (mesh_network_control(network_pdu)) {
843 
844                     incoming_control_pdu =  &incoming_pdu_singleton.control;
845                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
846                     incoming_control_pdu->len =  network_pdu->len;
847                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
848 
849                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
850 
851                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
852                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
853                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
854 
855                     // copy meta data into encrypted pdu buffer
856                     incoming_control_pdu->ivi_nid = network_pdu->data[0];
857                     incoming_control_pdu->ctl_ttl = network_pdu->data[1];
858                     incoming_control_pdu->seq = big_endian_read_24(network_pdu->data, 2);
859                     incoming_control_pdu->src = big_endian_read_16(network_pdu->data, 5);
860                     incoming_control_pdu->dst = big_endian_read_16(network_pdu->data, 7);
861 
862                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
863 
864                     // free mesh message
865                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
866 
867                     btstack_assert(mesh_control_message_handler != NULL);
868                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t*) incoming_control_pdu);
869 
870                 } else {
871 
872                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
873 
874                     incoming_access_decrypted = &incoming_pdu_singleton.access;
875                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
876                     incoming_access_decrypted->flags = 0;
877                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
878                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
879                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
880                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
881                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
882                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
883                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
884                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
885 
886                     mesh_upper_transport_process_access_message();
887                 }
888                 break;
889             case MESH_PDU_TYPE_SEGMENTED:
890                 segmented_pdu = (mesh_segmented_pdu_t *) pdu;
891                 uint8_t ctl = segmented_pdu->ctl_ttl >> 7;
892                 if (ctl){
893                     incoming_control_pdu=  &incoming_pdu_singleton.control;
894                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
895 
896                     // flatten
897                     mesh_segmented_pdu_flatten(&segmented_pdu->segments, 8, incoming_control_pdu->data);
898 
899                     // copy meta data into encrypted pdu buffer
900                     incoming_control_pdu->flags = 0;
901                     incoming_control_pdu->len =  segmented_pdu->len;
902                     incoming_control_pdu->netkey_index =  segmented_pdu->netkey_index;
903                     incoming_control_pdu->akf_aid_control = segmented_pdu->akf_aid_control;
904                     incoming_control_pdu->ivi_nid = segmented_pdu->ivi_nid;
905                     incoming_control_pdu->ctl_ttl = segmented_pdu->ctl_ttl;
906                     incoming_control_pdu->seq = segmented_pdu->seq;
907                     incoming_control_pdu->src = segmented_pdu->src;
908                     incoming_control_pdu->dst = segmented_pdu->dst;
909 
910                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
911 
912                     // free mesh message
913                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)segmented_pdu);
914 
915                     btstack_assert(mesh_control_message_handler != NULL);
916                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t*) incoming_control_pdu);
917 
918                 } else {
919 
920                     incoming_access_encrypted = (mesh_pdu_t *) segmented_pdu;
921 
922                     incoming_access_decrypted = &incoming_pdu_singleton.access;
923                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
924                     incoming_access_decrypted->flags = segmented_pdu->flags;
925                     incoming_access_decrypted->len =  segmented_pdu->len;
926                     incoming_access_decrypted->netkey_index = segmented_pdu->netkey_index;
927                     incoming_access_decrypted->akf_aid_control =  segmented_pdu->akf_aid_control;
928                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
929                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
930                     incoming_access_decrypted->seq = segmented_pdu->seq;
931                     incoming_access_decrypted->src = segmented_pdu->src;
932                     incoming_access_decrypted->dst = segmented_pdu->dst;
933 
934                     mesh_upper_transport_process_access_message();
935                 }
936                 break;
937             default:
938                 btstack_assert(0);
939                 break;
940         }
941     }
942 
943     btstack_linked_list_iterator_t it;
944     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing);
945     while (btstack_linked_list_iterator_has_next(&it)){
946 
947         if (crypto_active) break;
948 
949         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
950         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == false) {
951             // skip pdu for now
952             continue;
953         }
954 
955         mesh_upper_transport_pdu_t * upper_pdu;
956         mesh_segmented_pdu_t * segmented_pdu;
957         uint8_t transmic_len;
958         bool ok;
959         bool abort_outgoing_loop = false;
960 
961         switch (pdu->pdu_type){
962             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
963                 // control pdus can go through directly
964                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
965                 btstack_linked_list_iterator_remove(&it);
966                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
967                 break;
968             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
969                 // control pdus can go through directly
970                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
971                 btstack_linked_list_iterator_remove(&it);
972                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
973                 break;
974             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
975                 // segmented access pdus required a mesh-segmented-pdu
976                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
977                 if (upper_pdu->lower_pdu == NULL){
978                     upper_pdu->lower_pdu  = (mesh_pdu_t *) btstack_memory_mesh_segmented_pdu_get();
979                 }
980                 if (upper_pdu->lower_pdu == NULL){
981                     mesh_upper_transport_need_pdu_for_run_outgoing();
982                     abort_outgoing_loop = true;
983                     break;
984                 }
985                 segmented_pdu = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
986                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
987                 // and a mesh-network-pdu for each segment in upper pdu
988                 transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
989                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + transmic_len);
990                 if (!ok) {
991                     abort_outgoing_loop = true;
992                     break;
993                 }
994                 // all buffers available, get started
995                 btstack_linked_list_iterator_remove(&it);
996                 mesh_upper_transport_send_access(upper_pdu);
997                 break;
998             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
999                 // unsegmented access pdus require a single mesh-network-dpu
1000                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1001                 if (upper_pdu->lower_pdu == NULL){
1002                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
1003                 }
1004                 if (upper_pdu->lower_pdu == NULL) {
1005                     mesh_upper_transport_need_pdu_for_run_outgoing();
1006                     abort_outgoing_loop = true;
1007                     break;
1008                 }
1009                 btstack_linked_list_iterator_remove(&it);
1010                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
1011                 break;
1012             default:
1013                 btstack_assert(false);
1014                 break;
1015         }
1016         if (abort_outgoing_loop) {
1017             break;
1018         }
1019     }
1020 }
1021 
1022 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_and_remove_pdu_for_lower(mesh_pdu_t * pdu_to_find){
1023     btstack_linked_list_iterator_t it;
1024     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
1025     mesh_upper_transport_pdu_t * upper_pdu;
1026     while (btstack_linked_list_iterator_has_next(&it)){
1027         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
1028         switch (mesh_pdu->pdu_type){
1029             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1030             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1031             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1032                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
1033                 if (upper_pdu->lower_pdu == pdu_to_find){
1034                     btstack_linked_list_iterator_remove(&it);
1035                     return upper_pdu;
1036                 }
1037                 break;
1038             default:
1039                 break;
1040         }
1041     }
1042     return NULL;
1043 }
1044 
1045 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
1046     mesh_upper_transport_pdu_t * upper_pdu;
1047     mesh_segmented_pdu_t * segmented_pdu;
1048     switch (callback_type){
1049         case MESH_TRANSPORT_PDU_RECEIVED:
1050             mesh_upper_transport_message_received(pdu);
1051             break;
1052         case MESH_TRANSPORT_PDU_SENT:
1053             switch (pdu->pdu_type){
1054                 case MESH_PDU_TYPE_SEGMENTED:
1055                     // try to find in outgoing active
1056                     upper_pdu = mesh_upper_transport_find_and_remove_pdu_for_lower(pdu);
1057                     btstack_assert(upper_pdu != NULL);
1058                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
1059                     // free chunks
1060                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
1061                         mesh_network_pdu_t * chunk_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
1062                         mesh_network_pdu_free(chunk_pdu);
1063                     }
1064                     // free segmented pdu
1065                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
1066                     upper_pdu->lower_pdu = NULL;
1067                     switch (upper_pdu->pdu_header.pdu_type){
1068                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1069                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1070                             break;
1071                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1072                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1073                             break;
1074                         default:
1075                             btstack_assert(false);
1076                             break;
1077                     }
1078                     break;
1079                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1080                     // find corresponding upper transport pdu and free single segment
1081                     upper_pdu = mesh_upper_transport_find_and_remove_pdu_for_lower(pdu);
1082                     btstack_assert(upper_pdu != NULL);
1083                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
1084                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
1085                     upper_pdu->lower_pdu = NULL;
1086                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
1087                     break;
1088                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1089                     mesh_access_message_handler(callback_type, status, pdu);
1090                     break;
1091                 default:
1092                     btstack_assert(false);
1093                     break;
1094             }
1095             mesh_upper_transport_run();
1096             break;
1097         default:
1098             break;
1099     }
1100 }
1101 
1102 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
1103     btstack_assert(pdu != NULL);
1104     mesh_network_pdu_t   * network_pdu;
1105     mesh_segmented_pdu_t   * message_pdu;
1106     mesh_upper_transport_pdu_t * upper_pdu;
1107     switch (pdu->pdu_type) {
1108         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1109         case MESH_PDU_TYPE_NETWORK:
1110             network_pdu = (mesh_network_pdu_t *) pdu;
1111             mesh_network_pdu_free(network_pdu);
1112             break;
1113         case MESH_PDU_TYPE_SEGMENTED:
1114             message_pdu = (mesh_segmented_pdu_t *) pdu;
1115             mesh_segmented_pdu_free(message_pdu);
1116             break;
1117         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1118         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1119         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1120             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1121             while (upper_pdu->segments) {
1122                 mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&upper_pdu->segments);
1123                 mesh_network_pdu_free(segment);
1124             }
1125             btstack_memory_mesh_upper_transport_pdu_free(upper_pdu);
1126             // check if send request can be handled now
1127             mesh_upper_transport_schedule_send_requests();
1128             break;
1129         default:
1130             btstack_assert(false);
1131             break;
1132     }
1133 }
1134 
1135 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1136     crypto_active = 0;
1137     switch (pdu->pdu_type){
1138         case MESH_PDU_TYPE_ACCESS:
1139             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1140             break;
1141         case MESH_PDU_TYPE_CONTROL:
1142             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1143             break;
1144         default:
1145             btstack_assert(0);
1146             break;
1147     }
1148 }
1149 
1150 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1151     switch (pdu->pdu_type){
1152         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1153         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1154             break;
1155         default:
1156             btstack_assert(false);
1157             break;
1158     }
1159 
1160     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1161 
1162     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1163     mesh_upper_transport_run();
1164 }
1165 
1166 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1167     switch (pdu->pdu_type){
1168         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1169             break;
1170         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1171             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1172             break;
1173         default:
1174             btstack_assert(false);
1175             break;
1176     }
1177 
1178     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1179     mesh_upper_transport_run();
1180 }
1181 
1182 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,
1183                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1184 
1185     btstack_assert(network_pdu != NULL);
1186     btstack_assert(control_pdu_len <= 11);
1187 
1188     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1189     if (!network_key) return 1;
1190 
1191     uint8_t transport_pdu_data[12];
1192     transport_pdu_data[0] = opcode;
1193     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1194     uint16_t transport_pdu_len = control_pdu_len + 1;
1195 
1196     // setup network_pdu
1197     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL;
1198     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1199 
1200     return 0;
1201 }
1202 
1203 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){
1204 
1205     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1206     if (!network_key) return 1;
1207 
1208     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1209     upper_pdu->ctl_ttl = ttl;
1210     upper_pdu->src = src;
1211     upper_pdu->dst = dest;
1212     upper_pdu->netkey_index = netkey_index;
1213     upper_pdu->akf_aid_control = opcode;
1214     return 0;
1215 }
1216 
1217 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1218                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1219 
1220     // get app or device key
1221     const mesh_transport_key_t *appkey;
1222     appkey = mesh_transport_key_get(appkey_index);
1223     if (appkey == NULL) {
1224         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1225         return 1;
1226     }
1227     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1228 
1229     // lookup network by netkey_index
1230     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1231     if (!network_key) return 1;
1232     if (network_key == NULL) {
1233         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1234         return 1;
1235     }
1236 
1237     // store in transport pdu
1238     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1239     upper_pdu->ctl_ttl = ttl;
1240     upper_pdu->src = src;
1241     upper_pdu->dst = dest;
1242     upper_pdu->netkey_index = netkey_index;
1243     upper_pdu->appkey_index = appkey_index;
1244     upper_pdu->akf_aid_control = akf_aid;
1245     if (szmic) {
1246         upper_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1247     }
1248     return 0;
1249 }
1250 
1251 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1252                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1253     switch (pdu->pdu_type){
1254         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1255         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1256             return mesh_upper_transport_setup_upper_access_pdu_header((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1257                                                                appkey_index, ttl, src, dest, szmic);
1258         default:
1259             btstack_assert(false);
1260             return 1;
1261     }
1262 }
1263 
1264 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)) {
1265     mesh_access_message_handler = callback;
1266 }
1267 
1268 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)){
1269     mesh_control_message_handler = callback;
1270 }
1271 
1272 void mesh_upper_transport_init(){
1273     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1274 }
1275 
1276 bool mesh_upper_transport_message_reserve(void){
1277     if (message_builder_reserved_upper_pdu == NULL){
1278         message_builder_reserved_upper_pdu = btstack_memory_mesh_upper_transport_pdu_get();
1279     }
1280     if (message_builder_reserved_upper_pdu == NULL){
1281         return false;
1282     }
1283     while (message_builder_num_network_pdus_reserved < MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS){
1284         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1285         if (network_pdu == NULL){
1286             return false;
1287         }
1288         btstack_linked_list_add(&message_builder_reserved_network_pdus, (btstack_linked_item_t *) network_pdu);
1289         message_builder_num_network_pdus_reserved++;
1290     }
1291     return true;
1292 }
1293 
1294 void mesh_upper_transport_message_init(mesh_upper_transport_builder_t * builder, mesh_pdu_type_t pdu_type) {
1295     btstack_assert(builder != NULL);
1296 
1297     // use reserved buffer if available
1298     if (message_builder_reserved_upper_pdu != NULL){
1299         builder->pdu = message_builder_reserved_upper_pdu;
1300         message_builder_reserved_upper_pdu = NULL;
1301     } else {
1302         builder->pdu = btstack_memory_mesh_upper_transport_pdu_get();
1303     }
1304     if (!builder->pdu) return;
1305 
1306     builder->segment = NULL;
1307     builder->pdu->pdu_header.pdu_type = pdu_type;
1308     builder->pdu->ack_opcode = MESH_ACCESS_OPCODE_NOT_SET;
1309 }
1310 
1311 
1312 void mesh_upper_transport_message_add_data(mesh_upper_transport_builder_t * builder, const uint8_t * data, uint16_t data_len){
1313     btstack_assert(builder != NULL);
1314 
1315     if (builder->pdu == NULL) return;
1316 
1317     builder->pdu->len += data_len;
1318 
1319     uint16_t bytes_current_segment = 0;
1320     if (builder->segment){
1321         bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX - builder->segment->len;
1322     }
1323     while (data_len > 0){
1324         if (bytes_current_segment == 0){
1325             // use reserved buffer if available
1326             if (message_builder_num_network_pdus_reserved > 0){
1327                 message_builder_num_network_pdus_reserved--;
1328                 builder->segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&message_builder_reserved_network_pdus);
1329             } else {
1330                 builder->segment = (mesh_network_pdu_t *) mesh_network_pdu_get();
1331             }
1332             if (builder->segment == NULL) {
1333                 mesh_upper_transport_pdu_free((mesh_pdu_t *) builder->pdu);
1334                 builder->pdu = NULL;
1335                 return;
1336             }
1337             btstack_linked_list_add_tail(&builder->pdu->segments, (btstack_linked_item_t *) builder->segment);
1338             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
1339         }
1340         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, data_len);
1341         (void) memcpy(&builder->segment->data[builder->segment->len], data, bytes_to_copy);
1342         builder->segment->len += bytes_to_copy;
1343         bytes_current_segment -= bytes_to_copy;
1344         data                  += bytes_to_copy;
1345         data_len              -= bytes_to_copy;
1346     }
1347 }
1348 
1349 void mesh_upper_transport_message_add_uint8(mesh_upper_transport_builder_t * builder, uint8_t value){
1350     mesh_upper_transport_message_add_data(builder, &value, 1);
1351 }
1352 
1353 void mesh_upper_transport_message_add_uint16(mesh_upper_transport_builder_t * builder, uint16_t value){
1354     uint8_t buffer[2];
1355     little_endian_store_16(buffer, 0, value);
1356     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1357 }
1358 
1359 void mesh_upper_transport_message_add_uint24(mesh_upper_transport_builder_t * builder, uint32_t value){
1360     uint8_t buffer[3];
1361     little_endian_store_24(buffer, 0, value);
1362     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1363 }
1364 
1365 void mesh_upper_transport_message_add_uint32(mesh_upper_transport_builder_t * builder, uint32_t value){
1366     uint8_t buffer[4];
1367     little_endian_store_32(buffer, 0, value);
1368     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1369 }
1370 
1371 mesh_upper_transport_pdu_t * mesh_upper_transport_message_finalize(mesh_upper_transport_builder_t * builder){
1372     return builder->pdu;
1373 }
1374