xref: /btstack/src/mesh/mesh_upper_transport.c (revision cd5f23a3250874824c01a2b3326a9522fea3f99f)
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,
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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
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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 
245         // on enter, bytes_current_segment = 0 => network_pdu = pop (in segements) + assert (network != NULL)
246         // cppcheck-suppress nullPointer
247         network_pdu->len += bytes_to_copy;
248         payload_offset += bytes_to_copy;
249     }
250 }
251 
252 // tries allocate and add enough segments to store payload of given size
253 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
254     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
255     while (storage_size < payload_len){
256         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
257         if (network_pdu == NULL) break;
258         storage_size += MESH_NETWORK_PAYLOAD_MAX;
259         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
260     }
261     return (storage_size >= payload_len);
262 }
263 
264 // stub lower transport
265 
266 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
267     printf("List: %s:\n", name);
268     btstack_linked_list_iterator_t it;
269     btstack_linked_list_iterator_init(&it, list);
270     while (btstack_linked_list_iterator_has_next(&it)){
271         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
272         printf("- %p\n", pdu);
273         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
274     }
275 }
276 
277 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
278     while (!btstack_linked_list_empty(list)){
279         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
280     }
281 }
282 
283 void mesh_upper_transport_dump(void){
284     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
285 }
286 
287 void mesh_upper_transport_reset(void){
288     crypto_active = 0;
289     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
290     mesh_upper_transport_reset_pdus(&upper_transport_outgoing);
291     message_builder_num_network_pdus_reserved = 0;
292     mesh_upper_transport_reset_pdus(&message_builder_reserved_network_pdus);
293     if (message_builder_reserved_upper_pdu != NULL){
294         btstack_memory_mesh_upper_transport_pdu_free(message_builder_reserved_upper_pdu);
295         message_builder_reserved_upper_pdu = NULL;
296     }
297 }
298 
299 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
300     // Device Key is fixed
301     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
302         return mesh_transport_key_get(appkey_index);
303     }
304 
305     // Get key refresh state from subnet
306     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
307     if (subnet == NULL) return NULL;
308 
309     // identify old and new app keys for given appkey_index
310     mesh_transport_key_t * old_key = NULL;
311     mesh_transport_key_t * new_key = NULL;
312     mesh_transport_key_iterator_t it;
313     mesh_transport_key_iterator_init(&it, netkey_index);
314     while (mesh_transport_key_iterator_has_more(&it)){
315         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
316         if (transport_key->appkey_index != appkey_index) continue;
317         if (transport_key->old_key == 0) {
318             new_key = transport_key;
319         } else {
320             old_key = transport_key;
321         }
322     }
323 
324     // if no key is marked as old, just use the current one
325     if (old_key == NULL) return new_key;
326 
327     // use new key if it exists in phase two
328     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
329         return new_key;
330     } else {
331         return old_key;
332     }
333 }
334 
335 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
336     // get IV Index and IVI
337     uint32_t iv_index = mesh_get_iv_index();
338     int ivi = ivi_nid >> 7;
339 
340     // if least significant bit differs, use previous IV Index
341     if ((iv_index & 1 ) ^ ivi){
342         iv_index--;
343     }
344     return iv_index;
345 }
346 
347 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
348     mesh_access_pdu_t * access_pdu;
349     mesh_upper_transport_pdu_t * upper_pdu;
350     switch (pdu->pdu_type){
351         case MESH_PDU_TYPE_ACCESS:
352             access_pdu = (mesh_access_pdu_t *) pdu;
353             nonce[1] = ((access_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
354             big_endian_store_24(nonce, 2, access_pdu->seq);
355             big_endian_store_16(nonce, 5, access_pdu->src);
356             big_endian_store_16(nonce, 7, access_pdu->dst);
357             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
358             break;
359         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
360         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
361             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
362             nonce[1] = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
363             // 'network header'
364             big_endian_store_24(nonce, 2, upper_pdu->seq);
365             big_endian_store_16(nonce, 5, upper_pdu->src);
366             big_endian_store_16(nonce, 7, upper_pdu->dst);
367             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
368             break;
369         default:
370             btstack_assert(0);
371             break;
372     }
373 }
374 
375 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
376     nonce[0] = 0x01;
377     transport_segmented_setup_nonce(nonce, pdu);
378     mesh_print_hex("AppNonce", nonce, 13);
379 }
380 
381 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
382     nonce[0] = 0x02;
383     transport_segmented_setup_nonce(nonce, pdu);
384     mesh_print_hex("DeviceNonce", nonce, 13);
385 }
386 
387 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
388     crypto_active = 0;
389     btstack_assert((access_pdu->ctl_ttl & 0x80) == 0);
390     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
391     incoming_access_encrypted = NULL;
392     incoming_access_decrypted = NULL;
393     mesh_upper_transport_run();
394 }
395 
396 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
397     UNUSED(control_pdu);
398     crypto_active = 0;
399     incoming_control_pdu = NULL;
400     mesh_upper_transport_run();
401 }
402 
403 static void mesh_upper_transport_network_pdu_freed(void){
404     // call both while prioritizing run outgoing
405     // both functions will trigger request for network pdu if needed
406     if (upper_transport_need_pdu_for_run_outgoing){
407         upper_transport_need_pdu_for_run_outgoing = false;
408         mesh_upper_transport_run();
409     }
410     if (upper_transport_need_pdu_for_send_requests){
411         upper_transport_need_pdu_for_send_requests = false;
412         mesh_upper_transport_schedule_send_requests();
413     }
414 }
415 
416 static void mesh_upper_transport_need_pdu_for_send_requests(void) {
417     bool waiting = upper_transport_need_pdu_for_send_requests || upper_transport_need_pdu_for_run_outgoing;
418     upper_transport_need_pdu_for_send_requests = true;
419     if (waiting == false) {
420         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_network_pdu_freed);
421     }
422 }
423 static void mesh_upper_transport_need_pdu_for_run_outgoing(void) {
424     bool waiting = upper_transport_need_pdu_for_send_requests || upper_transport_need_pdu_for_run_outgoing;
425     upper_transport_need_pdu_for_run_outgoing = true;
426     if (waiting == false) {
427         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_network_pdu_freed);
428     }
429 }
430 
431 static void mesh_upper_transport_deliver_access_message(void) {
432     incoming_access_pdu_ready = false;
433     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t *) incoming_access_decrypted);
434 }
435 
436 static bool mesh_upper_transport_send_requests_pending(void){
437     if (incoming_access_pdu_ready) {
438         return true;
439     }
440     return btstack_linked_list_empty(&upper_transport_send_requests) == false;
441 }
442 
443 static void mesh_upper_transport_schedule_send_requests(void){
444 
445     while (mesh_upper_transport_send_requests_pending()){
446 
447         // get ready
448         bool message_builder_ready = mesh_upper_transport_message_reserve();
449 
450         if (message_builder_ready == false){
451             // waiting for free upper pdu, we will get called again on pdu free
452             if (message_builder_reserved_upper_pdu == NULL){
453                 return;
454             }
455             // request callback on network pdu free
456             mesh_upper_transport_need_pdu_for_send_requests();
457             return;
458         }
459 
460         // process send requests
461 
462         // incoming access pdu
463         if (incoming_access_pdu_ready){
464             // message builder ready = one outgoing pdu is guaranteed, deliver access pdu
465             mesh_upper_transport_deliver_access_message();
466             continue;
467         }
468 
469         // regular send request
470         btstack_context_callback_registration_t * send_request = (btstack_context_callback_registration_t *) btstack_linked_list_pop(&upper_transport_send_requests);
471         btstack_assert(send_request != NULL);
472         (*send_request->callback)(send_request->context);
473     }
474 }
475 
476 void mesh_upper_transport_request_to_send(btstack_context_callback_registration_t * request){
477     btstack_linked_list_add_tail(&upper_transport_send_requests, (btstack_linked_item_t *) request);
478     mesh_upper_transport_schedule_send_requests();
479 }
480 
481 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
482     UNUSED(arg);
483 
484     uint8_t transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
485     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
486     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
487 
488     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
489 
490     // store TransMIC
491     uint8_t trans_mic[8];
492     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
493     mesh_print_hex("TransMIC", trans_mic, transmic_len);
494 
495     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transmic_len) == 0){
496         printf("TransMIC matches\n");
497 
498         // remove TransMIC from payload
499         incoming_access_decrypted->len -= transmic_len;
500 
501         // if virtual address, update dst to pseudo_dst
502         if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
503             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
504         }
505 
506         // pass to upper layer
507         incoming_access_pdu_ready = true;
508         mesh_upper_transport_schedule_send_requests();
509 
510     } else {
511         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
512         if (akf){
513             printf("TransMIC does not match, try next key\n");
514             mesh_upper_transport_validate_access_message();
515         } else {
516             printf("TransMIC does not match device key, done\n");
517             // done
518             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
519         }
520     }
521 }
522 
523 static void mesh_upper_transport_validate_access_message_digest(void * arg){
524     UNUSED(arg);
525     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
526     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - transmic_len;
527     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
528 
529     mesh_network_pdu_t * unsegmented_pdu = NULL;
530     mesh_segmented_pdu_t * segmented_pdu = NULL;
531     switch (incoming_access_encrypted->pdu_type){
532         case MESH_PDU_TYPE_SEGMENTED:
533             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
534             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
535             mesh_print_hex("Encrypted Payload:", upper_transport_pdu_data_out, upper_transport_pdu_len);
536             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
537                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
538             break;
539         case MESH_PDU_TYPE_UNSEGMENTED:
540             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
541             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
542             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
543                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
544             break;
545         default:
546             btstack_assert(false);
547             break;
548     }
549 
550 }
551 
552 static void mesh_upper_transport_validate_access_message(void){
553     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
554     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
555     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - transmic_len;
556 
557     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
558         printf("No valid transport key found\n");
559         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
560         return;
561     }
562     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
563     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
564 
565     if (message_key->akf){
566         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
567     } else {
568         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
569     }
570 
571     // store application / device key index
572     mesh_print_hex("AppOrDevKey", message_key->key, 16);
573     incoming_access_decrypted->appkey_index = message_key->appkey_index;
574 
575     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
576 
577     // decrypt ccm
578     crypto_active = 1;
579     uint16_t aad_len  = 0;
580     if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
581         aad_len  = 16;
582     }
583     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transmic_len);
584 
585     if (aad_len){
586         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
587                                   &mesh_upper_transport_validate_access_message_digest, NULL);
588     } else {
589         mesh_upper_transport_validate_access_message_digest(NULL);
590     }
591 }
592 
593 static void mesh_upper_transport_process_access_message(void){
594     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
595     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
596     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
597     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
598 
599     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
600     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
601 
602     printf("AKF: %u\n",   akf);
603     printf("AID: %02x\n", aid);
604 
605     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, incoming_access_decrypted->dst,
606                                                          incoming_access_decrypted->netkey_index, akf, aid);
607     mesh_upper_transport_validate_access_message();
608 }
609 
610 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
611     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
612     mesh_upper_transport_run();
613 }
614 
615 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
616 
617     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
618     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
619 
620     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
621     btstack_linked_list_t free_segments = segmented_pdu->segments;
622     segmented_pdu->segments = NULL;
623     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
624 
625     // copy meta
626     segmented_pdu->len = upper_pdu->len;
627     segmented_pdu->netkey_index = upper_pdu->netkey_index;
628     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
629     segmented_pdu->flags = upper_pdu->flags;
630 
631     // setup segmented_pdu header
632     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
633     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
634     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
635     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
636     segmented_pdu->seq = upper_pdu->seq;
637     segmented_pdu->src = upper_pdu->src;
638     segmented_pdu->dst = upper_pdu->dst;
639 
640     // queue up
641     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
642     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
643 
644     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
645 }
646 
647 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
648 
649     // provide segment
650     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
651 
652     // setup network pdu
653     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
654     network_pdu->data[0] = upper_pdu->ivi_nid;
655     network_pdu->data[1] = upper_pdu->ctl_ttl;
656     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
657     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
658     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
659     network_pdu->netkey_index = upper_pdu->netkey_index;
660 
661     // setup access message
662     network_pdu->data[9] = upper_pdu->akf_aid_control;
663     btstack_assert(upper_pdu->len < 15);
664     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
665     network_pdu->len = 10 + upper_pdu->len;
666     network_pdu->flags = 0;
667 
668     // queue up
669     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
670 
671     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
672 }
673 
674 static void mesh_upper_transport_send_access_ccm(void * arg){
675     crypto_active = 0;
676 
677     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
678     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
679     // store TransMIC
680     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
681     uint8_t transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
682     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], transmic_len);
683     upper_pdu->len += transmic_len;
684     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
685     switch (upper_pdu->pdu_header.pdu_type){
686         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
687             mesh_upper_transport_send_access_unsegmented(upper_pdu);
688             break;
689         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
690             mesh_upper_transport_send_access_segmented(upper_pdu);
691             break;
692         default:
693             btstack_assert(false);
694     }
695 }
696 
697 static void mesh_upper_transport_send_access_digest(void *arg){
698     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
699     uint16_t  access_pdu_len  = upper_pdu->len;
700     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
701                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
702 }
703 
704 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
705 
706     // if dst is virtual address, lookup label uuid and hash
707     uint16_t aad_len = 0;
708     mesh_virtual_address_t * virtual_address = NULL;
709     if (mesh_network_address_virtual(upper_pdu->dst)){
710         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
711         if (!virtual_address){
712             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
713             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
714             return;
715         }
716         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
717         // printf_hexdump(virtual_address->label_uuid, 16);
718         aad_len = 16;
719         upper_pdu->dst = virtual_address->hash;
720     }
721 
722     // get app or device key
723     uint16_t appkey_index = upper_pdu->appkey_index;
724     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
725     if (appkey == NULL){
726         printf("AppKey %04x not found, drop message\n", appkey_index);
727         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
728         return;
729     }
730 
731     // reserve slot
732     mesh_lower_transport_reserve_slot();
733 
734     // reserve one sequence number, which is also used to encrypt access payload
735     uint32_t seq = mesh_sequence_number_next();
736     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
737     upper_pdu->seq = seq;
738 
739     // also reserves crypto_buffer
740     crypto_active = 1;
741 
742     // flatten segmented pdu into crypto buffer
743     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
744     btstack_assert(payload_len == upper_pdu->len);
745     UNUSED(payload_len);
746 
747     // Dump PDU
748     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
749     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
750 
751     // setup nonce - uses dst, so after pseudo address translation
752     if (appkey_index == MESH_DEVICE_KEY_INDEX){
753         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
754     } else {
755         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
756     }
757 
758     // Dump key
759     mesh_print_hex("AppOrDevKey", appkey->key, 16);
760 
761     // encrypt ccm
762     uint8_t   transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
763     uint16_t  access_pdu_len  = upper_pdu->len;
764     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
765     if (virtual_address){
766         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
767         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
768                                   &mesh_upper_transport_send_access_digest, upper_pdu);
769     } else {
770         mesh_upper_transport_send_access_digest(upper_pdu);
771     }
772 }
773 
774 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
775     // reserve slot
776     mesh_lower_transport_reserve_slot();
777     // reserve sequence number
778     uint32_t seq = mesh_sequence_number_next();
779     mesh_network_pdu_set_seq(network_pdu, seq);
780     // Dump PDU
781     uint8_t opcode = network_pdu->data[9];
782     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
783     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
784 
785     // send
786      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
787 }
788 
789 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
790     // reserve slot
791     mesh_lower_transport_reserve_slot();
792     // reserve sequence number
793     uint32_t seq = mesh_sequence_number_next();
794     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
795     upper_pdu->seq = seq;
796     // Dump PDU
797     // uint8_t opcode = upper_pdu->data[0];
798     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
799     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
800     // send
801     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
802     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
803 
804     // lend segments to lower transport pdu
805     segmented_pdu->segments = upper_pdu->segments;
806     upper_pdu->segments = NULL;
807 
808     // copy meta
809     segmented_pdu->len = upper_pdu->len;
810     segmented_pdu->netkey_index = upper_pdu->netkey_index;
811     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
812     segmented_pdu->flags = upper_pdu->flags;
813 
814     btstack_assert((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) == 0);
815 
816     // setup segmented_pdu header
817     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
818     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
819     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
820     segmented_pdu->seq = upper_pdu->seq;
821     segmented_pdu->src = upper_pdu->src;
822     segmented_pdu->dst = upper_pdu->dst;
823 
824     // queue up
825     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
826     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
827 
828     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
829 }
830 
831 static void mesh_upper_transport_run(void){
832 
833     while(!btstack_linked_list_empty(&upper_transport_incoming)){
834 
835         if (crypto_active) return;
836 
837         // get next message
838         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
839         mesh_network_pdu_t   * network_pdu;
840         mesh_segmented_pdu_t   * segmented_pdu;
841         switch (pdu->pdu_type){
842             case MESH_PDU_TYPE_UNSEGMENTED:
843                 network_pdu = (mesh_network_pdu_t *) pdu;
844                 // control?
845                 if (mesh_network_control(network_pdu)) {
846 
847                     incoming_control_pdu =  &incoming_pdu_singleton.control;
848                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
849                     incoming_control_pdu->len =  network_pdu->len;
850                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
851 
852                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
853 
854                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
855                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
856                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
857 
858                     // copy meta data into encrypted pdu buffer
859                     incoming_control_pdu->ivi_nid = network_pdu->data[0];
860                     incoming_control_pdu->ctl_ttl = network_pdu->data[1];
861                     incoming_control_pdu->seq = big_endian_read_24(network_pdu->data, 2);
862                     incoming_control_pdu->src = big_endian_read_16(network_pdu->data, 5);
863                     incoming_control_pdu->dst = big_endian_read_16(network_pdu->data, 7);
864 
865                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
866 
867                     // free mesh message
868                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
869 
870                     btstack_assert(mesh_control_message_handler != NULL);
871                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t*) incoming_control_pdu);
872 
873                 } else {
874 
875                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
876 
877                     incoming_access_decrypted = &incoming_pdu_singleton.access;
878                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
879                     incoming_access_decrypted->flags = 0;
880                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
881                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
882                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
883                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
884                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
885                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
886                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
887                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
888 
889                     mesh_upper_transport_process_access_message();
890                 }
891                 break;
892             case MESH_PDU_TYPE_SEGMENTED:
893                 segmented_pdu = (mesh_segmented_pdu_t *) pdu;
894                 uint8_t ctl = segmented_pdu->ctl_ttl >> 7;
895                 if (ctl){
896                     incoming_control_pdu=  &incoming_pdu_singleton.control;
897                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
898 
899                     // flatten
900                     mesh_segmented_pdu_flatten(&segmented_pdu->segments, 8, incoming_control_pdu->data);
901 
902                     // copy meta data into encrypted pdu buffer
903                     incoming_control_pdu->flags = 0;
904                     incoming_control_pdu->len =  segmented_pdu->len;
905                     incoming_control_pdu->netkey_index =  segmented_pdu->netkey_index;
906                     incoming_control_pdu->akf_aid_control = segmented_pdu->akf_aid_control;
907                     incoming_control_pdu->ivi_nid = segmented_pdu->ivi_nid;
908                     incoming_control_pdu->ctl_ttl = segmented_pdu->ctl_ttl;
909                     incoming_control_pdu->seq = segmented_pdu->seq;
910                     incoming_control_pdu->src = segmented_pdu->src;
911                     incoming_control_pdu->dst = segmented_pdu->dst;
912 
913                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
914 
915                     // free mesh message
916                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)segmented_pdu);
917 
918                     btstack_assert(mesh_control_message_handler != NULL);
919                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t*) incoming_control_pdu);
920 
921                 } else {
922 
923                     incoming_access_encrypted = (mesh_pdu_t *) segmented_pdu;
924 
925                     incoming_access_decrypted = &incoming_pdu_singleton.access;
926                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
927                     incoming_access_decrypted->flags = segmented_pdu->flags;
928                     incoming_access_decrypted->len =  segmented_pdu->len;
929                     incoming_access_decrypted->netkey_index = segmented_pdu->netkey_index;
930                     incoming_access_decrypted->akf_aid_control =  segmented_pdu->akf_aid_control;
931                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
932                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
933                     incoming_access_decrypted->seq = segmented_pdu->seq;
934                     incoming_access_decrypted->src = segmented_pdu->src;
935                     incoming_access_decrypted->dst = segmented_pdu->dst;
936 
937                     mesh_upper_transport_process_access_message();
938                 }
939                 break;
940             default:
941                 btstack_assert(0);
942                 break;
943         }
944     }
945 
946     btstack_linked_list_iterator_t it;
947     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing);
948     while (btstack_linked_list_iterator_has_next(&it)){
949 
950         if (crypto_active) break;
951 
952         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
953         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == false) {
954             // skip pdu for now
955             continue;
956         }
957 
958         mesh_upper_transport_pdu_t * upper_pdu;
959         mesh_segmented_pdu_t * segmented_pdu;
960         uint8_t transmic_len;
961         bool ok;
962         bool abort_outgoing_loop = false;
963 
964         switch (pdu->pdu_type){
965             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
966                 // control pdus can go through directly
967                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
968                 btstack_linked_list_iterator_remove(&it);
969                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
970                 break;
971             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
972                 // control pdus can go through directly
973                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
974                 btstack_linked_list_iterator_remove(&it);
975                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
976                 break;
977             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
978                 // segmented access pdus required a mesh-segmented-pdu
979                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
980                 if (upper_pdu->lower_pdu == NULL){
981                     upper_pdu->lower_pdu  = (mesh_pdu_t *) btstack_memory_mesh_segmented_pdu_get();
982                 }
983                 if (upper_pdu->lower_pdu == NULL){
984                     mesh_upper_transport_need_pdu_for_run_outgoing();
985                     abort_outgoing_loop = true;
986                     break;
987                 }
988                 segmented_pdu = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
989                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
990                 // and a mesh-network-pdu for each segment in upper pdu
991                 transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
992                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + transmic_len);
993                 if (!ok) {
994                     abort_outgoing_loop = true;
995                     break;
996                 }
997                 // all buffers available, get started
998                 btstack_linked_list_iterator_remove(&it);
999                 mesh_upper_transport_send_access(upper_pdu);
1000                 break;
1001             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1002                 // unsegmented access pdus require a single mesh-network-dpu
1003                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1004                 if (upper_pdu->lower_pdu == NULL){
1005                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
1006                 }
1007                 if (upper_pdu->lower_pdu == NULL) {
1008                     mesh_upper_transport_need_pdu_for_run_outgoing();
1009                     abort_outgoing_loop = true;
1010                     break;
1011                 }
1012                 btstack_linked_list_iterator_remove(&it);
1013                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
1014                 break;
1015             default:
1016                 btstack_assert(false);
1017                 break;
1018         }
1019         if (abort_outgoing_loop) {
1020             break;
1021         }
1022     }
1023 }
1024 
1025 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_and_remove_pdu_for_lower(mesh_pdu_t * pdu_to_find){
1026     btstack_linked_list_iterator_t it;
1027     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
1028     mesh_upper_transport_pdu_t * upper_pdu;
1029     while (btstack_linked_list_iterator_has_next(&it)){
1030         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
1031         switch (mesh_pdu->pdu_type){
1032             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1033             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1034             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1035                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
1036                 if (upper_pdu->lower_pdu == pdu_to_find){
1037                     btstack_linked_list_iterator_remove(&it);
1038                     return upper_pdu;
1039                 }
1040                 break;
1041             default:
1042                 break;
1043         }
1044     }
1045     return NULL;
1046 }
1047 
1048 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
1049     mesh_upper_transport_pdu_t * upper_pdu;
1050     mesh_segmented_pdu_t * segmented_pdu;
1051     switch (callback_type){
1052         case MESH_TRANSPORT_PDU_RECEIVED:
1053             mesh_upper_transport_message_received(pdu);
1054             break;
1055         case MESH_TRANSPORT_PDU_SENT:
1056             switch (pdu->pdu_type){
1057                 case MESH_PDU_TYPE_SEGMENTED:
1058                     // try to find in outgoing active
1059                     upper_pdu = mesh_upper_transport_find_and_remove_pdu_for_lower(pdu);
1060                     btstack_assert(upper_pdu != NULL);
1061                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
1062                     // free chunks
1063                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
1064                         mesh_network_pdu_t * chunk_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
1065                         mesh_network_pdu_free(chunk_pdu);
1066                     }
1067                     // free segmented pdu
1068                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
1069                     upper_pdu->lower_pdu = NULL;
1070                     switch (upper_pdu->pdu_header.pdu_type){
1071                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1072                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1073                             break;
1074                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1075                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1076                             break;
1077                         default:
1078                             btstack_assert(false);
1079                             break;
1080                     }
1081                     break;
1082                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1083                     // find corresponding upper transport pdu and free single segment
1084                     upper_pdu = mesh_upper_transport_find_and_remove_pdu_for_lower(pdu);
1085                     btstack_assert(upper_pdu != NULL);
1086                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
1087                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
1088                     upper_pdu->lower_pdu = NULL;
1089                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
1090                     break;
1091                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1092                     mesh_access_message_handler(callback_type, status, pdu);
1093                     break;
1094                 default:
1095                     btstack_assert(false);
1096                     break;
1097             }
1098             mesh_upper_transport_run();
1099             break;
1100         default:
1101             break;
1102     }
1103 }
1104 
1105 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
1106     btstack_assert(pdu != NULL);
1107     mesh_network_pdu_t   * network_pdu;
1108     mesh_segmented_pdu_t   * message_pdu;
1109     mesh_upper_transport_pdu_t * upper_pdu;
1110     switch (pdu->pdu_type) {
1111         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1112         case MESH_PDU_TYPE_NETWORK:
1113             network_pdu = (mesh_network_pdu_t *) pdu;
1114             mesh_network_pdu_free(network_pdu);
1115             break;
1116         case MESH_PDU_TYPE_SEGMENTED:
1117             message_pdu = (mesh_segmented_pdu_t *) pdu;
1118             mesh_segmented_pdu_free(message_pdu);
1119             break;
1120         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1121         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1122         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1123             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1124             while (upper_pdu->segments) {
1125                 mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&upper_pdu->segments);
1126                 mesh_network_pdu_free(segment);
1127             }
1128             btstack_memory_mesh_upper_transport_pdu_free(upper_pdu);
1129             // check if send request can be handled now
1130             mesh_upper_transport_schedule_send_requests();
1131             break;
1132         default:
1133             btstack_assert(false);
1134             break;
1135     }
1136 }
1137 
1138 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1139     crypto_active = 0;
1140     switch (pdu->pdu_type){
1141         case MESH_PDU_TYPE_ACCESS:
1142             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1143             break;
1144         case MESH_PDU_TYPE_CONTROL:
1145             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1146             break;
1147         default:
1148             btstack_assert(0);
1149             break;
1150     }
1151 }
1152 
1153 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1154     switch (pdu->pdu_type){
1155         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1156         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1157             break;
1158         default:
1159             btstack_assert(false);
1160             break;
1161     }
1162 
1163     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1164 
1165     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1166     mesh_upper_transport_run();
1167 }
1168 
1169 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1170     switch (pdu->pdu_type){
1171         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1172             break;
1173         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1174             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1175             break;
1176         default:
1177             btstack_assert(false);
1178             break;
1179     }
1180 
1181     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1182     mesh_upper_transport_run();
1183 }
1184 
1185 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,
1186                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1187 
1188     btstack_assert(network_pdu != NULL);
1189     btstack_assert(control_pdu_len <= 11);
1190 
1191     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1192     if (!network_key) return 1;
1193 
1194     uint8_t transport_pdu_data[12];
1195     transport_pdu_data[0] = opcode;
1196     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1197     uint16_t transport_pdu_len = control_pdu_len + 1;
1198 
1199     // setup network_pdu
1200     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL;
1201     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1202 
1203     return 0;
1204 }
1205 
1206 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){
1207 
1208     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1209     if (!network_key) return 1;
1210 
1211     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1212     upper_pdu->ctl_ttl = ttl;
1213     upper_pdu->src = src;
1214     upper_pdu->dst = dest;
1215     upper_pdu->netkey_index = netkey_index;
1216     upper_pdu->akf_aid_control = opcode;
1217     return 0;
1218 }
1219 
1220 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1221                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1222 
1223     // get app or device key
1224     const mesh_transport_key_t *appkey;
1225     appkey = mesh_transport_key_get(appkey_index);
1226     if (appkey == NULL) {
1227         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1228         return 1;
1229     }
1230     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1231 
1232     // lookup network by netkey_index
1233     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1234     if (!network_key) return 1;
1235     if (network_key == NULL) {
1236         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1237         return 1;
1238     }
1239 
1240     // store in transport pdu
1241     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1242     upper_pdu->ctl_ttl = ttl;
1243     upper_pdu->src = src;
1244     upper_pdu->dst = dest;
1245     upper_pdu->netkey_index = netkey_index;
1246     upper_pdu->appkey_index = appkey_index;
1247     upper_pdu->akf_aid_control = akf_aid;
1248     if (szmic) {
1249         upper_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1250     }
1251     return 0;
1252 }
1253 
1254 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1255                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1256     switch (pdu->pdu_type){
1257         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1258         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1259             return mesh_upper_transport_setup_upper_access_pdu_header((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1260                                                                appkey_index, ttl, src, dest, szmic);
1261         default:
1262             btstack_assert(false);
1263             return 1;
1264     }
1265 }
1266 
1267 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)) {
1268     mesh_access_message_handler = callback;
1269 }
1270 
1271 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)){
1272     mesh_control_message_handler = callback;
1273 }
1274 
1275 void mesh_upper_transport_init(){
1276     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1277 }
1278 
1279 bool mesh_upper_transport_message_reserve(void){
1280     if (message_builder_reserved_upper_pdu == NULL){
1281         message_builder_reserved_upper_pdu = btstack_memory_mesh_upper_transport_pdu_get();
1282     }
1283     if (message_builder_reserved_upper_pdu == NULL){
1284         return false;
1285     }
1286     while (message_builder_num_network_pdus_reserved < MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS){
1287         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1288         if (network_pdu == NULL){
1289             return false;
1290         }
1291         btstack_linked_list_add(&message_builder_reserved_network_pdus, (btstack_linked_item_t *) network_pdu);
1292         message_builder_num_network_pdus_reserved++;
1293     }
1294     return true;
1295 }
1296 
1297 void mesh_upper_transport_message_init(mesh_upper_transport_builder_t * builder, mesh_pdu_type_t pdu_type) {
1298     btstack_assert(builder != NULL);
1299 
1300     // use reserved buffer if available
1301     if (message_builder_reserved_upper_pdu != NULL){
1302         builder->pdu = message_builder_reserved_upper_pdu;
1303         message_builder_reserved_upper_pdu = NULL;
1304     } else {
1305         builder->pdu = btstack_memory_mesh_upper_transport_pdu_get();
1306     }
1307     if (!builder->pdu) return;
1308 
1309     builder->segment = NULL;
1310     builder->pdu->pdu_header.pdu_type = pdu_type;
1311     builder->pdu->ack_opcode = MESH_ACCESS_OPCODE_NOT_SET;
1312 }
1313 
1314 
1315 void mesh_upper_transport_message_add_data(mesh_upper_transport_builder_t * builder, const uint8_t * data, uint16_t data_len){
1316     btstack_assert(builder != NULL);
1317 
1318     if (builder->pdu == NULL) return;
1319 
1320     builder->pdu->len += data_len;
1321 
1322     uint16_t bytes_current_segment = 0;
1323     if (builder->segment){
1324         bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX - builder->segment->len;
1325     }
1326     while (data_len > 0){
1327         if (bytes_current_segment == 0){
1328             // use reserved buffer if available
1329             if (message_builder_num_network_pdus_reserved > 0){
1330                 message_builder_num_network_pdus_reserved--;
1331                 builder->segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&message_builder_reserved_network_pdus);
1332             } else {
1333                 builder->segment = (mesh_network_pdu_t *) mesh_network_pdu_get();
1334             }
1335             if (builder->segment == NULL) {
1336                 mesh_upper_transport_pdu_free((mesh_pdu_t *) builder->pdu);
1337                 builder->pdu = NULL;
1338                 return;
1339             }
1340             btstack_linked_list_add_tail(&builder->pdu->segments, (btstack_linked_item_t *) builder->segment);
1341             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
1342         }
1343         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, data_len);
1344         (void) memcpy(&builder->segment->data[builder->segment->len], data, bytes_to_copy);
1345         builder->segment->len += bytes_to_copy;
1346         bytes_current_segment -= bytes_to_copy;
1347         data                  += bytes_to_copy;
1348         data_len              -= bytes_to_copy;
1349     }
1350 }
1351 
1352 void mesh_upper_transport_message_add_uint8(mesh_upper_transport_builder_t * builder, uint8_t value){
1353     mesh_upper_transport_message_add_data(builder, &value, 1);
1354 }
1355 
1356 void mesh_upper_transport_message_add_uint16(mesh_upper_transport_builder_t * builder, uint16_t value){
1357     uint8_t buffer[2];
1358     little_endian_store_16(buffer, 0, value);
1359     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1360 }
1361 
1362 void mesh_upper_transport_message_add_uint24(mesh_upper_transport_builder_t * builder, uint32_t value){
1363     uint8_t buffer[3];
1364     little_endian_store_24(buffer, 0, value);
1365     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1366 }
1367 
1368 void mesh_upper_transport_message_add_uint32(mesh_upper_transport_builder_t * builder, uint32_t value){
1369     uint8_t buffer[4];
1370     little_endian_store_32(buffer, 0, value);
1371     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1372 }
1373 
1374 mesh_upper_transport_pdu_t * mesh_upper_transport_message_finalize(mesh_upper_transport_builder_t * builder){
1375     return builder->pdu;
1376 }
1377