xref: /btstack/src/mesh/mesh_upper_transport.c (revision 37225d6f594bb56b83c81c5f699af95b7afaf2d0)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
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33  * Please inquire about commercial licensing options at
34  * [email protected]
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36  */
37 
38 #include <stdarg.h>
39 #include "btstack_tlv.h"
40 #include "mesh/mesh_foundation.h"
41 #include "mesh_upper_transport.h"
42 #include "mesh/mesh.h"
43 #include "mesh/mesh_proxy.h"
44 #include "mesh/mesh_node.h"
45 
46 #define BTSTACK_FILE__ "mesh_upper_transport.c"
47 
48 #include "mesh/mesh_upper_transport.h"
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 
54 #include "btstack_util.h"
55 #include "btstack_memory.h"
56 #include "btstack_debug.h"
57 #include "btstack_bool.h"
58 
59 #include "mesh/beacon.h"
60 #include "mesh/mesh_iv_index_seq_number.h"
61 #include "mesh/mesh_keys.h"
62 #include "mesh/mesh_lower_transport.h"
63 #include "mesh/mesh_peer.h"
64 #include "mesh/mesh_virtual_addresses.h"
65 
66 // TODO: extract mesh_pdu functions into lower transport or network
67 #include "mesh/mesh_access.h"
68 
69 // MESH_ACCESS_MESH_NETWORK_PAYLOAD_MAX (384) / MESH_NETWORK_PAYLOAD_MAX (29) = 13.24.. < 14
70 #define MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS (14)
71 
72 // combined key x address iterator for upper transport decryption
73 
74 typedef struct {
75     // state
76     mesh_transport_key_iterator_t  key_it;
77     mesh_virtual_address_iterator_t address_it;
78     // elements
79     const mesh_transport_key_t *   key;
80     const mesh_virtual_address_t * address;
81     // address - might be virtual
82     uint16_t dst;
83     // key info
84 } mesh_transport_key_and_virtual_address_iterator_t;
85 
86 static void mesh_upper_transport_validate_access_message(void);
87 static void mesh_upper_transport_run(void);
88 
89 // upper transport callbacks - in access layer
90 static void (*mesh_access_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
91 static void (*mesh_control_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
92 
93 //
94 static int crypto_active;
95 static uint8_t application_nonce[13];
96 static btstack_crypto_ccm_t ccm;
97 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
98 
99 // incoming segmented (mesh_segmented_pdu_t) or unsegmented (network_pdu_t)
100 static mesh_pdu_t *          incoming_access_encrypted;
101 
102 // multi-purpose union: segmented control reassembly, decrypted access pdu
103 static union {
104     mesh_control_pdu_t    control;
105     mesh_access_pdu_t     access;
106 } incoming_pdu_singleton;
107 
108 // pointer to incoming_pdu_singleton.access
109 static mesh_access_pdu_t *   incoming_access_decrypted;
110 
111 // pointer to incoming_pdu_singleton.access
112 static mesh_control_pdu_t *  incoming_control_pdu;
113 
114 // incoming incoming_access_decrypted ready to be deliverd
115 static bool incoming_access_pdu_ready;
116 
117 // incoming unsegmented (network) and segmented (transport) control and access messages
118 static btstack_linked_list_t upper_transport_incoming;
119 
120 
121 // outgoing unsegmented and segmented control and access messages
122 static btstack_linked_list_t upper_transport_outgoing;
123 
124 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
125 static btstack_linked_list_t upper_transport_outgoing_active;
126 
127 // outgoing send requests
128 static btstack_linked_list_t upper_transport_send_requests;
129 
130 // message builder buffers
131 static mesh_upper_transport_pdu_t * message_builder_reserved_upper_pdu;
132 static uint8_t message_builder_num_network_pdus_reserved;
133 static btstack_linked_list_t message_builder_reserved_network_pdus;
134 
135 // TODO: higher layer define used for assert
136 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
137 
138 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
139     printf("%-20s ", name);
140     printf_hexdump(data, len);
141 }
142 // static void mesh_print_x(const char * name, uint32_t value){
143 //     printf("%20s: 0x%x", name, (int) value);
144 // }
145 
146 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
147                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
148                                                                  uint8_t aid) {
149     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
150     // config
151     it->dst   = dst;
152     // init elements
153     it->key     = NULL;
154     it->address = NULL;
155     // init element iterators
156     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
157     // init address iterator
158     if (mesh_network_address_virtual(it->dst)){
159         mesh_virtual_address_iterator_init(&it->address_it, dst);
160         // get first key
161         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
162             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
163         }
164     }
165 }
166 
167 // cartesian product: keys x addressses
168 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
169     if (mesh_network_address_virtual(it->dst)) {
170         // find next valid entry
171         while (true){
172             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
173             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
174             // get next key
175             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
176             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
177         }
178     } else {
179         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
180     }
181 }
182 
183 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
184     if (mesh_network_address_virtual(it->dst)) {
185         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
186     } else {
187         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
188     }
189 }
190 
191 // UPPER TRANSPORT
192 
193 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
194     // assemble payload
195     btstack_linked_list_iterator_t it;
196     btstack_linked_list_iterator_init(&it, segments);
197     while (btstack_linked_list_iterator_has_next(&it)) {
198         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
199         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
200         uint8_t offset = 0;
201         while (offset < segment->len){
202             uint8_t seg_o = segment->data[offset++];
203             (void) memcpy(&buffer[seg_o * segment_len], &segment->data[offset], segment_len);
204             offset += segment_len;
205         }
206     }
207 }
208 
209 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
210     // assemble payload
211     btstack_linked_list_iterator_t it;
212     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
213     uint16_t offset = 0;
214     while (btstack_linked_list_iterator_has_next(&it)) {
215         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
216         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
217         btstack_assert((offset + segment->len) <= buffer_len);
218         (void) memcpy(&buffer[offset], segment->data, segment->len);
219         offset += segment->len;
220     }
221     return offset;
222 }
223 
224 // store payload in provided list of network pdus
225 static void mesh_segmented_store_payload(const uint8_t * payload, uint16_t payload_len, btstack_linked_list_t * in_segments, btstack_linked_list_t * out_segments){
226     uint16_t payload_offset = 0;
227     uint16_t bytes_current_segment = 0;
228     mesh_network_pdu_t * network_pdu = NULL;
229     while (payload_offset < payload_len){
230         if (bytes_current_segment == 0){
231             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
232             btstack_assert(network_pdu != NULL);
233             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
234             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
235         }
236         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
237         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
238         bytes_current_segment -= bytes_to_copy;
239         network_pdu->len += bytes_to_copy;
240         payload_offset += bytes_to_copy;
241     }
242 }
243 
244 // tries allocate and add enough segments to store payload of given size
245 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
246     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
247     while (storage_size < payload_len){
248         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
249         if (network_pdu == NULL) break;
250         storage_size += MESH_NETWORK_PAYLOAD_MAX;
251         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
252     }
253     return (storage_size >= payload_len);
254 }
255 
256 // stub lower transport
257 
258 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
259     printf("List: %s:\n", name);
260     btstack_linked_list_iterator_t it;
261     btstack_linked_list_iterator_init(&it, list);
262     while (btstack_linked_list_iterator_has_next(&it)){
263         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
264         printf("- %p\n", pdu);
265         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
266     }
267 }
268 
269 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
270     while (!btstack_linked_list_empty(list)){
271         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
272     }
273 }
274 
275 void mesh_upper_transport_dump(void){
276     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
277 }
278 
279 void mesh_upper_transport_reset(void){
280     crypto_active = 0;
281     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
282 }
283 
284 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
285     // Device Key is fixed
286     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
287         return mesh_transport_key_get(appkey_index);
288     }
289 
290     // Get key refresh state from subnet
291     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
292     if (subnet == NULL) return NULL;
293 
294     // identify old and new app keys for given appkey_index
295     mesh_transport_key_t * old_key = NULL;
296     mesh_transport_key_t * new_key = NULL;
297     mesh_transport_key_iterator_t it;
298     mesh_transport_key_iterator_init(&it, netkey_index);
299     while (mesh_transport_key_iterator_has_more(&it)){
300         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
301         if (transport_key->appkey_index != appkey_index) continue;
302         if (transport_key->old_key == 0) {
303             new_key = transport_key;
304         } else {
305             old_key = transport_key;
306         }
307     }
308 
309     // if no key is marked as old, just use the current one
310     if (old_key == NULL) return new_key;
311 
312     // use new key if it exists in phase two
313     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
314         return new_key;
315     } else {
316         return old_key;
317     }
318 }
319 
320 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
321     // get IV Index and IVI
322     uint32_t iv_index = mesh_get_iv_index();
323     int ivi = ivi_nid >> 7;
324 
325     // if least significant bit differs, use previous IV Index
326     if ((iv_index & 1 ) ^ ivi){
327         iv_index--;
328     }
329     return iv_index;
330 }
331 
332 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
333     mesh_access_pdu_t * access_pdu;
334     mesh_upper_transport_pdu_t * upper_pdu;
335     switch (pdu->pdu_type){
336         case MESH_PDU_TYPE_ACCESS:
337             access_pdu = (mesh_access_pdu_t *) pdu;
338             nonce[1] = ((access_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
339             big_endian_store_24(nonce, 2, access_pdu->seq);
340             big_endian_store_16(nonce, 5, access_pdu->src);
341             big_endian_store_16(nonce, 7, access_pdu->dst);
342             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
343             break;
344         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
345         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
346             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
347             nonce[1] = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
348             // 'network header'
349             big_endian_store_24(nonce, 2, upper_pdu->seq);
350             big_endian_store_16(nonce, 5, upper_pdu->src);
351             big_endian_store_16(nonce, 7, upper_pdu->dst);
352             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
353             break;
354         default:
355             btstack_assert(0);
356             break;
357     }
358 }
359 
360 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
361     nonce[0] = 0x01;
362     transport_segmented_setup_nonce(nonce, pdu);
363     mesh_print_hex("AppNonce", nonce, 13);
364 }
365 
366 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
367     nonce[0] = 0x02;
368     transport_segmented_setup_nonce(nonce, pdu);
369     mesh_print_hex("DeviceNonce", nonce, 13);
370 }
371 
372 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
373     crypto_active = 0;
374     btstack_assert((access_pdu->ctl_ttl & 0x80) == 0);
375     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
376     incoming_access_encrypted = NULL;
377     incoming_access_decrypted = NULL;
378     mesh_upper_transport_run();
379 }
380 
381 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
382     crypto_active = 0;
383     incoming_control_pdu = NULL;
384     mesh_upper_transport_run();
385 }
386 
387 static void mesh_upper_transport_deliver_access_message(void) {
388     incoming_access_pdu_ready = false;
389     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t *) incoming_access_decrypted);
390 }
391 
392 static bool mesh_upper_transport_send_requests_pending(void){
393     if (incoming_access_pdu_ready) {
394         return true;
395     }
396     return btstack_linked_list_empty(&upper_transport_send_requests) == false;
397 }
398 
399 static void mesh_upper_transport_schedule_send_requests(void){
400 
401     while (mesh_upper_transport_send_requests_pending()){
402 
403         // get ready
404         bool message_builder_ready = mesh_upper_transport_message_reserve();
405 
406         if (message_builder_ready == false){
407             // waiting for free upper pdu, we will get called again on pdu free
408             if (message_builder_reserved_upper_pdu == false){
409                 return;
410             }
411             // request callback on network pdu free
412             mesh_network_notify_on_freed_pdu(&mesh_upper_transport_schedule_send_requests);
413             return;
414         }
415 
416         // process send requests
417 
418         // incoming access pdu
419         if (incoming_access_pdu_ready){
420             // message builder ready = one outgoing pdu is guaranteed, deliver access pdu
421             mesh_upper_transport_deliver_access_message();
422             continue;
423         }
424 
425         // regular send request
426         btstack_context_callback_registration_t * send_request = (btstack_context_callback_registration_t *) btstack_linked_list_pop(&upper_transport_send_requests);
427         btstack_assert(send_request != NULL);
428         (*send_request->callback)(send_request->context);
429     }
430 }
431 
432 void mesh_upper_transport_request_to_send(btstack_context_callback_registration_t * request){
433     btstack_linked_list_add_tail(&upper_transport_send_requests, (btstack_linked_item_t *) request);
434     mesh_upper_transport_schedule_send_requests();
435 }
436 
437 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
438     UNUSED(arg);
439 
440     uint8_t transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
441     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
442     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
443 
444     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
445 
446     // store TransMIC
447     uint8_t trans_mic[8];
448     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
449     mesh_print_hex("TransMIC", trans_mic, transmic_len);
450 
451     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transmic_len) == 0){
452         printf("TransMIC matches\n");
453 
454         // remove TransMIC from payload
455         incoming_access_decrypted->len -= transmic_len;
456 
457         // if virtual address, update dst to pseudo_dst
458         if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
459             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
460         }
461 
462         // pass to upper layer
463         incoming_access_pdu_ready = true;
464         mesh_upper_transport_schedule_send_requests();
465 
466     } else {
467         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
468         if (akf){
469             printf("TransMIC does not match, try next key\n");
470             mesh_upper_transport_validate_access_message();
471         } else {
472             printf("TransMIC does not match device key, done\n");
473             // done
474             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
475         }
476     }
477 }
478 
479 static void mesh_upper_transport_validate_access_message_digest(void * arg){
480     UNUSED(arg);
481     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
482     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - transmic_len;
483     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
484 
485     mesh_network_pdu_t * unsegmented_pdu = NULL;
486     mesh_segmented_pdu_t * segmented_pdu = NULL;
487     switch (incoming_access_encrypted->pdu_type){
488         case MESH_PDU_TYPE_SEGMENTED:
489             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
490             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
491             mesh_print_hex("Encrypted Payload:", upper_transport_pdu_data_out, upper_transport_pdu_len);
492             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
493                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
494             break;
495         case MESH_PDU_TYPE_UNSEGMENTED:
496             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
497             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
498             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
499                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
500             break;
501         default:
502             btstack_assert(false);
503             break;
504     }
505 
506 }
507 
508 static void mesh_upper_transport_validate_access_message(void){
509     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
510     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
511     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - transmic_len;
512 
513     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
514         printf("No valid transport key found\n");
515         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
516         return;
517     }
518     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
519     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
520 
521     if (message_key->akf){
522         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
523     } else {
524         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
525     }
526 
527     // store application / device key index
528     mesh_print_hex("AppOrDevKey", message_key->key, 16);
529     incoming_access_decrypted->appkey_index = message_key->appkey_index;
530 
531     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
532 
533     // decrypt ccm
534     crypto_active = 1;
535     uint16_t aad_len  = 0;
536     if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
537         aad_len  = 16;
538     }
539     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transmic_len);
540 
541     if (aad_len){
542         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
543                                   &mesh_upper_transport_validate_access_message_digest, NULL);
544     } else {
545         mesh_upper_transport_validate_access_message_digest(NULL);
546     }
547 }
548 
549 static void mesh_upper_transport_process_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     =  incoming_access_decrypted->data;
552     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
553     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
554 
555     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
556     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
557 
558     printf("AKF: %u\n",   akf);
559     printf("AID: %02x\n", aid);
560 
561     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, incoming_access_decrypted->dst,
562                                                          incoming_access_decrypted->netkey_index, akf, aid);
563     mesh_upper_transport_validate_access_message();
564 }
565 
566 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
567     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
568     mesh_upper_transport_run();
569 }
570 
571 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
572 
573     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
574     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
575 
576     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
577     btstack_linked_list_t free_segments = segmented_pdu->segments;
578     segmented_pdu->segments = NULL;
579     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
580 
581     // copy meta
582     segmented_pdu->len = upper_pdu->len;
583     segmented_pdu->netkey_index = upper_pdu->netkey_index;
584     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
585     segmented_pdu->flags = upper_pdu->flags;
586 
587     // setup segmented_pdu header
588     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
589     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
590     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
591     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
592     segmented_pdu->seq = upper_pdu->seq;
593     segmented_pdu->src = upper_pdu->src;
594     segmented_pdu->dst = upper_pdu->dst;
595 
596     // queue up
597     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
598     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
599 
600     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
601 }
602 
603 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
604 
605     // provide segment
606     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
607 
608     // setup network pdu
609     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
610     network_pdu->data[0] = upper_pdu->ivi_nid;
611     network_pdu->data[1] = upper_pdu->ctl_ttl;
612     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
613     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
614     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
615     network_pdu->netkey_index = upper_pdu->netkey_index;
616 
617     // setup access message
618     network_pdu->data[9] = upper_pdu->akf_aid_control;
619     btstack_assert(upper_pdu->len < 15);
620     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
621     network_pdu->len = 10 + upper_pdu->len;
622     network_pdu->flags = 0;
623 
624     // queue up
625     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
626 
627     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
628 }
629 
630 static void mesh_upper_transport_send_access_ccm(void * arg){
631     crypto_active = 0;
632 
633     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
634     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
635     // store TransMIC
636     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
637     uint8_t transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
638     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], transmic_len);
639     upper_pdu->len += transmic_len;
640     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
641     switch (upper_pdu->pdu_header.pdu_type){
642         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
643             mesh_upper_transport_send_access_unsegmented(upper_pdu);
644             break;
645         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
646             mesh_upper_transport_send_access_segmented(upper_pdu);
647             break;
648         default:
649             btstack_assert(false);
650     }
651 }
652 
653 static void mesh_upper_transport_send_access_digest(void *arg){
654     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
655     uint16_t  access_pdu_len  = upper_pdu->len;
656     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
657                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
658 }
659 
660 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
661 
662     // if dst is virtual address, lookup label uuid and hash
663     uint16_t aad_len = 0;
664     mesh_virtual_address_t * virtual_address = NULL;
665     if (mesh_network_address_virtual(upper_pdu->dst)){
666         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
667         if (!virtual_address){
668             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
669             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
670             return;
671         }
672         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
673         // printf_hexdump(virtual_address->label_uuid, 16);
674         aad_len = 16;
675         upper_pdu->dst = virtual_address->hash;
676     }
677 
678     // get app or device key
679     uint16_t appkey_index = upper_pdu->appkey_index;
680     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
681     if (appkey == NULL){
682         printf("AppKey %04x not found, drop message\n", appkey_index);
683         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
684         return;
685     }
686 
687     // reserve slot
688     mesh_lower_transport_reserve_slot();
689 
690     // reserve one sequence number, which is also used to encrypt access payload
691     uint32_t seq = mesh_sequence_number_next();
692     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
693     upper_pdu->seq = seq;
694 
695     // also reserves crypto_buffer
696     crypto_active = 1;
697 
698     // flatten segmented pdu into crypto buffer
699     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
700     btstack_assert(payload_len == upper_pdu->len);
701 
702     // Dump PDU
703     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
704     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
705 
706     // setup nonce - uses dst, so after pseudo address translation
707     if (appkey_index == MESH_DEVICE_KEY_INDEX){
708         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
709     } else {
710         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
711     }
712 
713     // Dump key
714     mesh_print_hex("AppOrDevKey", appkey->key, 16);
715 
716     // encrypt ccm
717     uint8_t   transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
718     uint16_t  access_pdu_len  = upper_pdu->len;
719     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
720     if (virtual_address){
721         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
722         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
723                                   &mesh_upper_transport_send_access_digest, upper_pdu);
724     } else {
725         mesh_upper_transport_send_access_digest(upper_pdu);
726     }
727 }
728 
729 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
730     // reserve slot
731     mesh_lower_transport_reserve_slot();
732     // reserve sequence number
733     uint32_t seq = mesh_sequence_number_next();
734     mesh_network_pdu_set_seq(network_pdu, seq);
735     // Dump PDU
736     uint8_t opcode = network_pdu->data[9];
737     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
738     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
739 
740     // send
741      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
742 }
743 
744 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
745     // reserve slot
746     mesh_lower_transport_reserve_slot();
747     // reserve sequence number
748     uint32_t seq = mesh_sequence_number_next();
749     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
750     upper_pdu->seq = seq;
751     // Dump PDU
752     // uint8_t opcode = upper_pdu->data[0];
753     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
754     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
755     // send
756     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
757     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
758 
759     // lend segments to lower transport pdu
760     segmented_pdu->segments = upper_pdu->segments;
761     upper_pdu->segments = NULL;
762 
763     // copy meta
764     segmented_pdu->len = upper_pdu->len;
765     segmented_pdu->netkey_index = upper_pdu->netkey_index;
766     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
767     segmented_pdu->flags = upper_pdu->flags;
768 
769     btstack_assert((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) == 0);
770 
771     // setup segmented_pdu header
772     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
773     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
774     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
775     segmented_pdu->seq = upper_pdu->seq;
776     segmented_pdu->src = upper_pdu->src;
777     segmented_pdu->dst = upper_pdu->dst;
778 
779     // queue up
780     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
781     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
782 
783     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
784 }
785 
786 static void mesh_upper_transport_run(void){
787 
788     while(!btstack_linked_list_empty(&upper_transport_incoming)){
789 
790         if (crypto_active) return;
791 
792         // get next message
793         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
794         mesh_network_pdu_t   * network_pdu;
795         mesh_segmented_pdu_t   * segmented_pdu;
796         switch (pdu->pdu_type){
797             case MESH_PDU_TYPE_UNSEGMENTED:
798                 network_pdu = (mesh_network_pdu_t *) pdu;
799                 // control?
800                 if (mesh_network_control(network_pdu)) {
801 
802                     incoming_control_pdu =  &incoming_pdu_singleton.control;
803                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
804                     incoming_control_pdu->len =  network_pdu->len;
805                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
806 
807                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
808 
809                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
810                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
811                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
812 
813                     // copy meta data into encrypted pdu buffer
814                     incoming_control_pdu->ivi_nid = network_pdu->data[0];
815                     incoming_control_pdu->ctl_ttl = network_pdu->data[1];
816                     incoming_control_pdu->seq = big_endian_read_24(network_pdu->data, 2);
817                     incoming_control_pdu->src = big_endian_read_16(network_pdu->data, 5);
818                     incoming_control_pdu->dst = big_endian_read_16(network_pdu->data, 7);
819 
820                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
821 
822                     // free mesh message
823                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
824 
825                     btstack_assert(mesh_control_message_handler != NULL);
826                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
827                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
828 
829                 } else {
830 
831                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
832 
833                     incoming_access_decrypted = &incoming_pdu_singleton.access;
834                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
835                     incoming_access_decrypted->flags = 0;
836                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
837                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
838                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
839                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
840                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
841                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
842                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
843                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
844 
845                     mesh_upper_transport_process_access_message();
846                 }
847                 break;
848             case MESH_PDU_TYPE_SEGMENTED:
849                 segmented_pdu = (mesh_segmented_pdu_t *) pdu;
850                 uint8_t ctl = segmented_pdu->ctl_ttl >> 7;
851                 if (ctl){
852                     incoming_control_pdu=  &incoming_pdu_singleton.control;
853                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
854 
855                     // flatten
856                     mesh_segmented_pdu_flatten(&segmented_pdu->segments, 8, incoming_control_pdu->data);
857 
858                     // copy meta data into encrypted pdu buffer
859                     incoming_control_pdu->flags = 0;
860                     incoming_control_pdu->len =  segmented_pdu->len;
861                     incoming_control_pdu->netkey_index =  segmented_pdu->netkey_index;
862                     incoming_control_pdu->akf_aid_control = segmented_pdu->akf_aid_control;
863                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
864                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
865                     incoming_access_decrypted->seq = segmented_pdu->seq;
866                     incoming_access_decrypted->src = segmented_pdu->src;
867                     incoming_access_decrypted->dst = segmented_pdu->dst;
868 
869                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
870 
871                     // free mesh message
872                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)segmented_pdu);
873 
874                     btstack_assert(mesh_control_message_handler != NULL);
875                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
876                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
877 
878                 } else {
879 
880                     incoming_access_encrypted = (mesh_pdu_t *) segmented_pdu;
881 
882                     incoming_access_decrypted = &incoming_pdu_singleton.access;
883                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
884                     incoming_access_decrypted->flags = segmented_pdu->flags;
885                     incoming_access_decrypted->len =  segmented_pdu->len;
886                     incoming_access_decrypted->netkey_index = segmented_pdu->netkey_index;
887                     incoming_access_decrypted->akf_aid_control =  segmented_pdu->akf_aid_control;
888                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
889                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
890                     incoming_access_decrypted->seq = segmented_pdu->seq;
891                     incoming_access_decrypted->src = segmented_pdu->src;
892                     incoming_access_decrypted->dst = segmented_pdu->dst;
893 
894                     mesh_upper_transport_process_access_message();
895                 }
896                 break;
897             default:
898                 btstack_assert(0);
899                 break;
900         }
901     }
902 
903     btstack_linked_list_iterator_t it;
904     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing);
905     while (btstack_linked_list_iterator_has_next(&it)){
906 
907         if (crypto_active) break;
908 
909         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
910         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == false) {
911             // skip pdu for now
912             continue;
913         }
914 
915         mesh_upper_transport_pdu_t * upper_pdu;
916         mesh_segmented_pdu_t * segmented_pdu;
917         uint8_t transmic_len;
918         bool ok;
919         bool abort_outgoing_loop = false;
920 
921         switch (pdu->pdu_type){
922             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
923                 // control pdus can go through directly
924                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
925                 btstack_linked_list_iterator_remove(&it);
926                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
927                 break;
928             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
929                 // control pdus can go through directly
930                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
931                 btstack_linked_list_iterator_remove(&it);
932                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
933                 break;
934             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
935                 // segmented access pdus required a mesh-segmented-pdu
936                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
937                 if (upper_pdu->lower_pdu == NULL){
938                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
939                 }
940                 if (segmented_pdu == NULL) {
941                     abort_outgoing_loop = true;
942                     break;
943                 }
944                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
945                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
946                 // and a mesh-network-pdu for each segment in upper pdu
947                 transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
948                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + transmic_len);
949                 if (!ok) {
950                     abort_outgoing_loop = true;
951                     break;
952                 }
953                 // all buffers available, get started
954                 btstack_linked_list_iterator_remove(&it);
955                 mesh_upper_transport_send_access(upper_pdu);
956                 break;
957             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
958                 // unsegmented access pdus require a single mesh-network-dpu
959                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
960                 if (upper_pdu->lower_pdu == NULL){
961                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
962                 }
963                 if (upper_pdu->lower_pdu == NULL) {
964                     abort_outgoing_loop = true;
965                     break;
966                 }
967                 btstack_linked_list_iterator_remove(&it);
968                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
969                 break;
970             default:
971                 btstack_assert(false);
972                 break;
973         }
974         if (abort_outgoing_loop) {
975             break;
976         }
977     }
978 }
979 
980 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
981     btstack_linked_list_iterator_t it;
982     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
983     mesh_upper_transport_pdu_t * upper_pdu;
984     while (btstack_linked_list_iterator_has_next(&it)){
985         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
986         switch (mesh_pdu->pdu_type){
987             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
988             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
989             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
990                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
991                 if (upper_pdu->lower_pdu == pdu_to_find){
992                     btstack_linked_list_iterator_remove(&it);
993                     return upper_pdu;
994                 }
995                 break;
996             default:
997                 break;
998         }
999     }
1000     return NULL;
1001 }
1002 
1003 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
1004     mesh_upper_transport_pdu_t * upper_pdu;
1005     mesh_network_pdu_t * network_pdu;
1006     mesh_segmented_pdu_t * segmented_pdu;
1007     switch (callback_type){
1008         case MESH_TRANSPORT_PDU_RECEIVED:
1009             mesh_upper_transport_message_received(pdu);
1010             break;
1011         case MESH_TRANSPORT_PDU_SENT:
1012             switch (pdu->pdu_type){
1013                 case MESH_PDU_TYPE_SEGMENTED:
1014                     // try to find in outgoing active
1015                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
1016                     btstack_assert(upper_pdu != NULL);
1017                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
1018                     // free chunks
1019                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
1020                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
1021                         mesh_network_pdu_free(network_pdu);
1022                     }
1023                     // free segmented pdu
1024                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
1025                     // TODO: free segmented_pdu
1026                     upper_pdu->lower_pdu = NULL;
1027                     switch (upper_pdu->pdu_header.pdu_type){
1028                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1029                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1030                             break;
1031                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1032                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
1033                             break;
1034                         default:
1035                             btstack_assert(false);
1036                             break;
1037                     }
1038                     break;
1039                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1040                     // find corresponding upper transport pdu and free single segment
1041                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
1042                     btstack_assert(upper_pdu != NULL);
1043                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
1044                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
1045                     upper_pdu->lower_pdu = NULL;
1046                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
1047                     break;
1048                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1049                     mesh_access_message_handler(callback_type, status, pdu);
1050                     break;
1051                 default:
1052                     btstack_assert(false);
1053                     break;
1054             }
1055             mesh_upper_transport_run();
1056             break;
1057         default:
1058             break;
1059     }
1060 }
1061 
1062 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
1063     btstack_assert(pdu != NULL);
1064     mesh_network_pdu_t   * network_pdu;
1065     mesh_segmented_pdu_t   * message_pdu;
1066     mesh_upper_transport_pdu_t * upper_pdu;
1067     switch (pdu->pdu_type) {
1068         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1069         case MESH_PDU_TYPE_NETWORK:
1070             network_pdu = (mesh_network_pdu_t *) pdu;
1071             mesh_network_pdu_free(network_pdu);
1072             break;
1073         case MESH_PDU_TYPE_SEGMENTED:
1074             message_pdu = (mesh_segmented_pdu_t *) pdu;
1075             mesh_segmented_pdu_free(message_pdu);
1076             break;
1077         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1078         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1079         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1080             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1081             while (upper_pdu->segments) {
1082                 mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&upper_pdu->segments);
1083                 mesh_network_pdu_free(segment);
1084             }
1085             btstack_memory_mesh_upper_transport_pdu_free(upper_pdu);
1086             // check if send request can be handled now
1087             mesh_upper_transport_schedule_send_requests();
1088             break;
1089         default:
1090             btstack_assert(false);
1091             break;
1092     }
1093 }
1094 
1095 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1096     crypto_active = 0;
1097     switch (pdu->pdu_type){
1098         case MESH_PDU_TYPE_ACCESS:
1099             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1100         case MESH_PDU_TYPE_CONTROL:
1101             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1102             break;
1103         default:
1104             btstack_assert(0);
1105             break;
1106     }
1107 }
1108 
1109 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1110     switch (pdu->pdu_type){
1111         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1112         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1113             break;
1114         default:
1115             btstack_assert(false);
1116             break;
1117     }
1118 
1119     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1120 
1121     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1122     mesh_upper_transport_run();
1123 }
1124 
1125 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1126     switch (pdu->pdu_type){
1127         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1128             break;
1129         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1130             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1131             break;
1132         default:
1133             btstack_assert(false);
1134             break;
1135     }
1136 
1137     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1138     mesh_upper_transport_run();
1139 }
1140 
1141 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,
1142                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1143 
1144     btstack_assert(network_pdu != NULL);
1145     btstack_assert(control_pdu_len <= 11);
1146 
1147     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1148     if (!network_key) return 1;
1149 
1150     uint8_t transport_pdu_data[12];
1151     transport_pdu_data[0] = opcode;
1152     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1153     uint16_t transport_pdu_len = control_pdu_len + 1;
1154 
1155     // setup network_pdu
1156     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL;
1157     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1158 
1159     return 0;
1160 }
1161 
1162 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){
1163 
1164     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1165     if (!network_key) return 1;
1166 
1167     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1168     upper_pdu->ctl_ttl = ttl;
1169     upper_pdu->src = src;
1170     upper_pdu->dst = dest;
1171     upper_pdu->netkey_index = netkey_index;
1172     upper_pdu->akf_aid_control = opcode;
1173     return 0;
1174 }
1175 
1176 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1177                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1178 
1179     // get app or device key
1180     const mesh_transport_key_t *appkey;
1181     appkey = mesh_transport_key_get(appkey_index);
1182     if (appkey == NULL) {
1183         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1184         return 1;
1185     }
1186     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1187 
1188     // lookup network by netkey_index
1189     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1190     if (!network_key) return 1;
1191     if (network_key == NULL) {
1192         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1193         return 1;
1194     }
1195 
1196     // store in transport pdu
1197     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1198     upper_pdu->ctl_ttl = ttl;
1199     upper_pdu->src = src;
1200     upper_pdu->dst = dest;
1201     upper_pdu->netkey_index = netkey_index;
1202     upper_pdu->appkey_index = appkey_index;
1203     upper_pdu->akf_aid_control = akf_aid;
1204     if (szmic) {
1205         upper_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1206     }
1207     return 0;
1208 }
1209 
1210 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1211                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1212     switch (pdu->pdu_type){
1213         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1214         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1215             return mesh_upper_transport_setup_upper_access_pdu_header((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1216                                                                appkey_index, ttl, src, dest, szmic);
1217         default:
1218             btstack_assert(false);
1219             return 1;
1220     }
1221 }
1222 
1223 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)) {
1224     mesh_access_message_handler = callback;
1225 }
1226 
1227 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)){
1228     mesh_control_message_handler = callback;
1229 }
1230 
1231 void mesh_upper_transport_init(){
1232     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1233 }
1234 
1235 bool mesh_upper_transport_message_reserve(void){
1236     if (message_builder_reserved_upper_pdu == NULL){
1237         message_builder_reserved_upper_pdu = btstack_memory_mesh_upper_transport_pdu_get();
1238     }
1239     if (message_builder_reserved_upper_pdu == NULL){
1240         return false;
1241     }
1242     while (message_builder_num_network_pdus_reserved < MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS){
1243         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1244         if (network_pdu == NULL){
1245             return false;
1246         }
1247         btstack_linked_list_add(&message_builder_reserved_network_pdus, (btstack_linked_item_t *) network_pdu);
1248         message_builder_num_network_pdus_reserved++;
1249     }
1250     return true;
1251 }
1252 
1253 void mesh_upper_transport_message_init(mesh_upper_transport_builder_t * builder, mesh_pdu_type_t pdu_type) {
1254     btstack_assert(builder != NULL);
1255 
1256     // use reserved buffer if available
1257     if (message_builder_reserved_upper_pdu != NULL){
1258         builder->pdu = message_builder_reserved_upper_pdu;
1259         message_builder_reserved_upper_pdu = NULL;
1260     } else {
1261         builder->pdu = btstack_memory_mesh_upper_transport_pdu_get();
1262     }
1263     if (!builder->pdu) return;
1264 
1265     builder->segment = NULL;
1266     builder->pdu->pdu_header.pdu_type = pdu_type;
1267     builder->pdu->ack_opcode = MESH_ACCESS_OPCODE_NOT_SET;
1268 }
1269 
1270 
1271 void mesh_upper_transport_message_add_data(mesh_upper_transport_builder_t * builder, const uint8_t * data, uint16_t data_len){
1272     btstack_assert(builder != NULL);
1273 
1274     if (builder->pdu == NULL) return;
1275 
1276     builder->pdu->len += data_len;
1277 
1278     uint16_t bytes_current_segment = 0;
1279     if (builder->segment){
1280         bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX - builder->segment->len;
1281     }
1282     while (data_len > 0){
1283         if (bytes_current_segment == 0){
1284             // use reserved buffer if available
1285             if (message_builder_num_network_pdus_reserved > 0){
1286                 message_builder_num_network_pdus_reserved--;
1287                 builder->segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&message_builder_reserved_network_pdus);
1288             } else {
1289                 builder->segment = (mesh_network_pdu_t *) mesh_network_pdu_get();
1290             }
1291             if (builder->segment == NULL) {
1292                 mesh_upper_transport_pdu_free((mesh_pdu_t *) builder->pdu);
1293                 builder->pdu = NULL;
1294                 return;
1295             }
1296             btstack_linked_list_add_tail(&builder->pdu->segments, (btstack_linked_item_t *) builder->segment);
1297             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
1298         }
1299         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, data_len);
1300         (void) memcpy(&builder->segment->data[builder->segment->len], data, bytes_to_copy);
1301         builder->segment->len += bytes_to_copy;
1302         bytes_current_segment -= bytes_to_copy;
1303         data                  += bytes_to_copy;
1304         data_len              -= bytes_to_copy;
1305     }
1306 }
1307 
1308 void mesh_upper_transport_message_add_uint8(mesh_upper_transport_builder_t * builder, uint8_t value){
1309     mesh_upper_transport_message_add_data(builder, &value, 1);
1310 }
1311 
1312 void mesh_upper_transport_message_add_uint16(mesh_upper_transport_builder_t * builder, uint16_t value){
1313     uint8_t buffer[2];
1314     little_endian_store_16(buffer, 0, value);
1315     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1316 }
1317 
1318 void mesh_upper_transport_message_add_uint24(mesh_upper_transport_builder_t * builder, uint16_t value){
1319     uint8_t buffer[3];
1320     little_endian_store_24(buffer, 0, value);
1321     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1322 }
1323 
1324 void mesh_upper_transport_message_add_uint32(mesh_upper_transport_builder_t * builder, uint16_t value){
1325     uint8_t buffer[4];
1326     little_endian_store_32(buffer, 0, value);
1327     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1328 }
1329 
1330 mesh_upper_transport_pdu_t * mesh_upper_transport_message_finalize(mesh_upper_transport_builder_t * builder){
1331     return builder->pdu;
1332 }
1333