xref: /btstack/src/mesh/mesh_upper_transport.c (revision 5efae9f328f83c3a42e3863d78fb4fdecf391929)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #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 // message builder buffers
128 static mesh_upper_transport_pdu_t * message_builder_reserved_upper_pdu;
129 static uint8_t message_builder_num_network_pdus_reserved;
130 static btstack_linked_list_t message_builder_reserved_network_pdus;
131 
132 // TODO: higher layer define used for assert
133 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
134 
135 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
136     printf("%-20s ", name);
137     printf_hexdump(data, len);
138 }
139 // static void mesh_print_x(const char * name, uint32_t value){
140 //     printf("%20s: 0x%x", name, (int) value);
141 // }
142 
143 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
144                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
145                                                                  uint8_t aid) {
146     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
147     // config
148     it->dst   = dst;
149     // init elements
150     it->key     = NULL;
151     it->address = NULL;
152     // init element iterators
153     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
154     // init address iterator
155     if (mesh_network_address_virtual(it->dst)){
156         mesh_virtual_address_iterator_init(&it->address_it, dst);
157         // get first key
158         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
159             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
160         }
161     }
162 }
163 
164 // cartesian product: keys x addressses
165 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
166     if (mesh_network_address_virtual(it->dst)) {
167         // find next valid entry
168         while (true){
169             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
170             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
171             // get next key
172             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
173             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
174         }
175     } else {
176         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
177     }
178 }
179 
180 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
181     if (mesh_network_address_virtual(it->dst)) {
182         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
183     } else {
184         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
185     }
186 }
187 
188 // UPPER TRANSPORT
189 
190 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
191     // assemble payload
192     btstack_linked_list_iterator_t it;
193     btstack_linked_list_iterator_init(&it, segments);
194     while (btstack_linked_list_iterator_has_next(&it)) {
195         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
196         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
197         uint8_t offset = 0;
198         while (offset < segment->len){
199             uint8_t seg_o = segment->data[offset++];
200             (void) memcpy(&buffer[seg_o * segment_len], &segment->data[offset], segment_len);
201             offset += segment_len;
202         }
203     }
204 }
205 
206 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
207     // assemble payload
208     btstack_linked_list_iterator_t it;
209     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
210     uint16_t offset = 0;
211     while (btstack_linked_list_iterator_has_next(&it)) {
212         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
213         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
214         btstack_assert((offset + segment->len) <= buffer_len);
215         (void) memcpy(&buffer[offset], segment->data, segment->len);
216         offset += segment->len;
217     }
218     return offset;
219 }
220 
221 // store payload in provided list of network pdus
222 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){
223     uint16_t payload_offset = 0;
224     uint16_t bytes_current_segment = 0;
225     mesh_network_pdu_t * network_pdu = NULL;
226     while (payload_offset < payload_len){
227         if (bytes_current_segment == 0){
228             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
229             btstack_assert(network_pdu != NULL);
230             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
231             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
232         }
233         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
234         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
235         bytes_current_segment -= bytes_to_copy;
236         network_pdu->len += bytes_to_copy;
237         payload_offset += bytes_to_copy;
238     }
239 }
240 
241 // tries allocate and add enough segments to store payload of given size
242 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
243     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
244     while (storage_size < payload_len){
245         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
246         if (network_pdu == NULL) break;
247         storage_size += MESH_NETWORK_PAYLOAD_MAX;
248         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
249     }
250     return (storage_size >= payload_len);
251 }
252 
253 // stub lower transport
254 
255 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
256     printf("List: %s:\n", name);
257     btstack_linked_list_iterator_t it;
258     btstack_linked_list_iterator_init(&it, list);
259     while (btstack_linked_list_iterator_has_next(&it)){
260         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
261         printf("- %p\n", pdu);
262         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
263     }
264 }
265 
266 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
267     while (!btstack_linked_list_empty(list)){
268         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
269     }
270 }
271 
272 void mesh_upper_transport_dump(void){
273     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
274 }
275 
276 void mesh_upper_transport_reset(void){
277     crypto_active = 0;
278     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
279 }
280 
281 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
282     // Device Key is fixed
283     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
284         return mesh_transport_key_get(appkey_index);
285     }
286 
287     // Get key refresh state from subnet
288     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
289     if (subnet == NULL) return NULL;
290 
291     // identify old and new app keys for given appkey_index
292     mesh_transport_key_t * old_key = NULL;
293     mesh_transport_key_t * new_key = NULL;
294     mesh_transport_key_iterator_t it;
295     mesh_transport_key_iterator_init(&it, netkey_index);
296     while (mesh_transport_key_iterator_has_more(&it)){
297         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
298         if (transport_key->appkey_index != appkey_index) continue;
299         if (transport_key->old_key == 0) {
300             new_key = transport_key;
301         } else {
302             old_key = transport_key;
303         }
304     }
305 
306     // if no key is marked as old, just use the current one
307     if (old_key == NULL) return new_key;
308 
309     // use new key if it exists in phase two
310     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
311         return new_key;
312     } else {
313         return old_key;
314     }
315 }
316 
317 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
318     // get IV Index and IVI
319     uint32_t iv_index = mesh_get_iv_index();
320     int ivi = ivi_nid >> 7;
321 
322     // if least significant bit differs, use previous IV Index
323     if ((iv_index & 1 ) ^ ivi){
324         iv_index--;
325     }
326     return iv_index;
327 }
328 
329 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
330     mesh_access_pdu_t * access_pdu;
331     mesh_upper_transport_pdu_t * upper_pdu;
332     switch (pdu->pdu_type){
333         case MESH_PDU_TYPE_ACCESS:
334             access_pdu = (mesh_access_pdu_t *) pdu;
335             nonce[1] = ((access_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
336             big_endian_store_24(nonce, 2, access_pdu->seq);
337             big_endian_store_16(nonce, 5, access_pdu->src);
338             big_endian_store_16(nonce, 7, access_pdu->dst);
339             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->ivi_nid));
340             break;
341         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
342         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
343             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
344             nonce[1] = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 0x80 : 0x00;
345             // 'network header'
346             big_endian_store_24(nonce, 2, upper_pdu->seq);
347             big_endian_store_16(nonce, 5, upper_pdu->src);
348             big_endian_store_16(nonce, 7, upper_pdu->dst);
349             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
350             break;
351         default:
352             btstack_assert(0);
353             break;
354     }
355 }
356 
357 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
358     nonce[0] = 0x01;
359     transport_segmented_setup_nonce(nonce, pdu);
360     mesh_print_hex("AppNonce", nonce, 13);
361 }
362 
363 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
364     nonce[0] = 0x02;
365     transport_segmented_setup_nonce(nonce, pdu);
366     mesh_print_hex("DeviceNonce", nonce, 13);
367 }
368 
369 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
370     crypto_active = 0;
371     btstack_assert((access_pdu->ctl_ttl & 0x80) == 0);
372     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
373     incoming_access_encrypted = NULL;
374     incoming_access_decrypted = NULL;
375     mesh_upper_transport_run();
376 }
377 
378 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
379     crypto_active = 0;
380     incoming_control_pdu = NULL;
381     mesh_upper_transport_run();
382 }
383 
384 static void mesh_upper_transport_deliver_access_message(void){
385     if (incoming_access_pdu_ready == false){
386         return;
387     }
388 
389     bool message_builder_ready = mesh_upper_transport_message_reserve();
390 
391     if (message_builder_ready == false){
392         // waiting for free upper pdu
393         if (message_builder_reserved_upper_pdu == false){
394             return;
395         }
396         // register for free network pdus if missing
397         mesh_network_notify_on_freed_pdu(&mesh_upper_transport_deliver_access_message);
398         return;
399     }
400 
401     // message builder ready = one outgoing pdu is guaranteed, deliver access pdu
402     incoming_access_pdu_ready = false;
403     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, (mesh_pdu_t *) incoming_access_decrypted);
404 }
405 
406 static void mesh_upper_transport_validate_access_message_ccm(void * arg){
407     UNUSED(arg);
408 
409     uint8_t transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
410     uint8_t * upper_transport_pdu     = incoming_access_decrypted->data;
411     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
412 
413     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
414 
415     // store TransMIC
416     uint8_t trans_mic[8];
417     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
418     mesh_print_hex("TransMIC", trans_mic, transmic_len);
419 
420     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transmic_len) == 0){
421         printf("TransMIC matches\n");
422 
423         // remove TransMIC from payload
424         incoming_access_decrypted->len -= transmic_len;
425 
426         // if virtual address, update dst to pseudo_dst
427         if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
428             incoming_access_decrypted->dst = mesh_transport_key_it.address->pseudo_dst;
429         }
430 
431         // pass to upper layer
432         incoming_access_pdu_ready = true;
433         mesh_upper_transport_deliver_access_message();
434 
435     } else {
436         uint8_t akf = incoming_access_decrypted->akf_aid_control & 0x40;
437         if (akf){
438             printf("TransMIC does not match, try next key\n");
439             mesh_upper_transport_validate_access_message();
440         } else {
441             printf("TransMIC does not match device key, done\n");
442             // done
443             mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
444         }
445     }
446 }
447 
448 static void mesh_upper_transport_validate_access_message_digest(void * arg){
449     UNUSED(arg);
450     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
451     uint8_t   upper_transport_pdu_len      = incoming_access_decrypted->len - transmic_len;
452     uint8_t * upper_transport_pdu_data_out = incoming_access_decrypted->data;
453 
454     mesh_network_pdu_t * unsegmented_pdu = NULL;
455     mesh_segmented_pdu_t * segmented_pdu = NULL;
456     switch (incoming_access_encrypted->pdu_type){
457         case MESH_PDU_TYPE_SEGMENTED:
458             segmented_pdu = (mesh_segmented_pdu_t *) incoming_access_encrypted;
459             mesh_segmented_pdu_flatten(&segmented_pdu->segments, 12, upper_transport_pdu_data_out);
460             mesh_print_hex("Encrypted Payload:", upper_transport_pdu_data_out, upper_transport_pdu_len);
461             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
462                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
463             break;
464         case MESH_PDU_TYPE_UNSEGMENTED:
465             unsegmented_pdu = (mesh_network_pdu_t *) incoming_access_encrypted;
466             (void)memcpy(upper_transport_pdu_data_out, &unsegmented_pdu->data[10], incoming_access_decrypted->len);
467             btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_out, upper_transport_pdu_data_out,
468                                              &mesh_upper_transport_validate_access_message_ccm, NULL);
469             break;
470         default:
471             btstack_assert(false);
472             break;
473     }
474 
475 }
476 
477 static void mesh_upper_transport_validate_access_message(void){
478     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
479     uint8_t * upper_transport_pdu_data =  incoming_access_decrypted->data;
480     uint8_t   upper_transport_pdu_len  = incoming_access_decrypted->len - transmic_len;
481 
482     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
483         printf("No valid transport key found\n");
484         mesh_upper_transport_process_access_message_done(incoming_access_decrypted);
485         return;
486     }
487     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
488     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
489 
490     if (message_key->akf){
491         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
492     } else {
493         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_decrypted);
494     }
495 
496     // store application / device key index
497     mesh_print_hex("AppOrDevKey", message_key->key, 16);
498     incoming_access_decrypted->appkey_index = message_key->appkey_index;
499 
500     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
501 
502     // decrypt ccm
503     crypto_active = 1;
504     uint16_t aad_len  = 0;
505     if (mesh_network_address_virtual(incoming_access_decrypted->dst)){
506         aad_len  = 16;
507     }
508     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transmic_len);
509 
510     if (aad_len){
511         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len,
512                                   &mesh_upper_transport_validate_access_message_digest, NULL);
513     } else {
514         mesh_upper_transport_validate_access_message_digest(NULL);
515     }
516 }
517 
518 static void mesh_upper_transport_process_access_message(void){
519     uint8_t   transmic_len = ((incoming_access_decrypted->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
520     uint8_t * upper_transport_pdu     =  incoming_access_decrypted->data;
521     uint8_t   upper_transport_pdu_len = incoming_access_decrypted->len - transmic_len;
522     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
523 
524     uint8_t aid = incoming_access_decrypted->akf_aid_control & 0x3f;
525     uint8_t akf = (incoming_access_decrypted->akf_aid_control & 0x40) >> 6;
526 
527     printf("AKF: %u\n",   akf);
528     printf("AID: %02x\n", aid);
529 
530     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, incoming_access_decrypted->dst,
531                                                          incoming_access_decrypted->netkey_index, akf, aid);
532     mesh_upper_transport_validate_access_message();
533 }
534 
535 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
536     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
537     mesh_upper_transport_run();
538 }
539 
540 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
541 
542     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
543     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
544 
545     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
546     btstack_linked_list_t free_segments = segmented_pdu->segments;
547     segmented_pdu->segments = NULL;
548     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
549 
550     // copy meta
551     segmented_pdu->len = upper_pdu->len;
552     segmented_pdu->netkey_index = upper_pdu->netkey_index;
553     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
554     segmented_pdu->flags = upper_pdu->flags;
555 
556     // setup segmented_pdu header
557     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
558     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
559     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
560     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
561     segmented_pdu->seq = upper_pdu->seq;
562     segmented_pdu->src = upper_pdu->src;
563     segmented_pdu->dst = upper_pdu->dst;
564 
565     // queue up
566     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
567     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
568 
569     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
570 }
571 
572 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
573 
574     // provide segment
575     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
576 
577     // setup network pdu
578     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
579     network_pdu->data[0] = upper_pdu->ivi_nid;
580     network_pdu->data[1] = upper_pdu->ctl_ttl;
581     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
582     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
583     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
584     network_pdu->netkey_index = upper_pdu->netkey_index;
585 
586     // setup access message
587     network_pdu->data[9] = upper_pdu->akf_aid_control;
588     btstack_assert(upper_pdu->len < 15);
589     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
590     network_pdu->len = 10 + upper_pdu->len;
591     network_pdu->flags = 0;
592 
593     // queue up
594     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
595 
596     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
597 }
598 
599 static void mesh_upper_transport_send_access_ccm(void * arg){
600     crypto_active = 0;
601 
602     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
603     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
604     // store TransMIC
605     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
606     uint8_t transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
607     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], transmic_len);
608     upper_pdu->len += transmic_len;
609     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
610     switch (upper_pdu->pdu_header.pdu_type){
611         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
612             mesh_upper_transport_send_access_unsegmented(upper_pdu);
613             break;
614         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
615             mesh_upper_transport_send_access_segmented(upper_pdu);
616             break;
617         default:
618             btstack_assert(false);
619     }
620 }
621 
622 static void mesh_upper_transport_send_access_digest(void *arg){
623     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
624     uint16_t  access_pdu_len  = upper_pdu->len;
625     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
626                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
627 }
628 
629 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
630 
631     // if dst is virtual address, lookup label uuid and hash
632     uint16_t aad_len = 0;
633     mesh_virtual_address_t * virtual_address = NULL;
634     if (mesh_network_address_virtual(upper_pdu->dst)){
635         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
636         if (!virtual_address){
637             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
638             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
639             return;
640         }
641         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
642         // printf_hexdump(virtual_address->label_uuid, 16);
643         aad_len = 16;
644         upper_pdu->dst = virtual_address->hash;
645     }
646 
647     // get app or device key
648     uint16_t appkey_index = upper_pdu->appkey_index;
649     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
650     if (appkey == NULL){
651         printf("AppKey %04x not found, drop message\n", appkey_index);
652         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
653         return;
654     }
655 
656     // reserve slot
657     mesh_lower_transport_reserve_slot();
658 
659     // reserve one sequence number, which is also used to encrypt access payload
660     uint32_t seq = mesh_sequence_number_next();
661     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
662     upper_pdu->seq = seq;
663 
664     // also reserves crypto_buffer
665     crypto_active = 1;
666 
667     // flatten segmented pdu into crypto buffer
668     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
669     btstack_assert(payload_len == upper_pdu->len);
670 
671     // Dump PDU
672     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
673     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
674 
675     // setup nonce - uses dst, so after pseudo address translation
676     if (appkey_index == MESH_DEVICE_KEY_INDEX){
677         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
678     } else {
679         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
680     }
681 
682     // Dump key
683     mesh_print_hex("AppOrDevKey", appkey->key, 16);
684 
685     // encrypt ccm
686     uint8_t   transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
687     uint16_t  access_pdu_len  = upper_pdu->len;
688     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
689     if (virtual_address){
690         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
691         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
692                                   &mesh_upper_transport_send_access_digest, upper_pdu);
693     } else {
694         mesh_upper_transport_send_access_digest(upper_pdu);
695     }
696 }
697 
698 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
699     // reserve slot
700     mesh_lower_transport_reserve_slot();
701     // reserve sequence number
702     uint32_t seq = mesh_sequence_number_next();
703     mesh_network_pdu_set_seq(network_pdu, seq);
704     // Dump PDU
705     uint8_t opcode = network_pdu->data[9];
706     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
707     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
708 
709     // send
710      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
711 }
712 
713 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
714     // reserve slot
715     mesh_lower_transport_reserve_slot();
716     // reserve sequence number
717     uint32_t seq = mesh_sequence_number_next();
718     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
719     upper_pdu->seq = seq;
720     // Dump PDU
721     // uint8_t opcode = upper_pdu->data[0];
722     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
723     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
724     // send
725     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
726     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
727 
728     // lend segments to lower transport pdu
729     segmented_pdu->segments = upper_pdu->segments;
730     upper_pdu->segments = NULL;
731 
732     // copy meta
733     segmented_pdu->len = upper_pdu->len;
734     segmented_pdu->netkey_index = upper_pdu->netkey_index;
735     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
736     segmented_pdu->flags = upper_pdu->flags;
737 
738     btstack_assert((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) == 0);
739 
740     // setup segmented_pdu header
741     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
742     segmented_pdu->ivi_nid = upper_pdu->ivi_nid;
743     segmented_pdu->ctl_ttl = upper_pdu->ctl_ttl;
744     segmented_pdu->seq = upper_pdu->seq;
745     segmented_pdu->src = upper_pdu->src;
746     segmented_pdu->dst = upper_pdu->dst;
747 
748     // queue up
749     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
750     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
751 
752     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
753 }
754 
755 static void mesh_upper_transport_run(void){
756 
757     while(!btstack_linked_list_empty(&upper_transport_incoming)){
758 
759         if (crypto_active) return;
760 
761         // get next message
762         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
763         mesh_network_pdu_t   * network_pdu;
764         mesh_segmented_pdu_t   * segmented_pdu;
765         switch (pdu->pdu_type){
766             case MESH_PDU_TYPE_UNSEGMENTED:
767                 network_pdu = (mesh_network_pdu_t *) pdu;
768                 // control?
769                 if (mesh_network_control(network_pdu)) {
770 
771                     incoming_control_pdu =  &incoming_pdu_singleton.control;
772                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
773                     incoming_control_pdu->len =  network_pdu->len;
774                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
775 
776                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
777 
778                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
779                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
780                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
781 
782                     // copy meta data into encrypted pdu buffer
783                     incoming_control_pdu->ivi_nid = network_pdu->data[0];
784                     incoming_control_pdu->ctl_ttl = network_pdu->data[1];
785                     incoming_control_pdu->seq = big_endian_read_24(network_pdu->data, 2);
786                     incoming_control_pdu->src = big_endian_read_16(network_pdu->data, 5);
787                     incoming_control_pdu->dst = big_endian_read_16(network_pdu->data, 7);
788 
789                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
790 
791                     // free mesh message
792                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
793 
794                     btstack_assert(mesh_control_message_handler != NULL);
795                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
796                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
797 
798                 } else {
799 
800                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
801 
802                     incoming_access_decrypted = &incoming_pdu_singleton.access;
803                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
804                     incoming_access_decrypted->flags = 0;
805                     incoming_access_decrypted->netkey_index = network_pdu->netkey_index;
806                     incoming_access_decrypted->akf_aid_control = network_pdu->data[9];
807                     incoming_access_decrypted->len = network_pdu->len - 10; // 9 header + 1 AID
808                     incoming_access_decrypted->ivi_nid = network_pdu->data[0];
809                     incoming_access_decrypted->ctl_ttl = network_pdu->data[1];
810                     incoming_access_decrypted->seq = big_endian_read_24(network_pdu->data, 2);
811                     incoming_access_decrypted->src = big_endian_read_16(network_pdu->data, 5);
812                     incoming_access_decrypted->dst = big_endian_read_16(network_pdu->data, 7);
813 
814                     mesh_upper_transport_process_access_message();
815                 }
816                 break;
817             case MESH_PDU_TYPE_SEGMENTED:
818                 segmented_pdu = (mesh_segmented_pdu_t *) pdu;
819                 uint8_t ctl = segmented_pdu->ctl_ttl >> 7;
820                 if (ctl){
821                     incoming_control_pdu=  &incoming_pdu_singleton.control;
822                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
823 
824                     // flatten
825                     mesh_segmented_pdu_flatten(&segmented_pdu->segments, 8, incoming_control_pdu->data);
826 
827                     // copy meta data into encrypted pdu buffer
828                     incoming_control_pdu->flags = 0;
829                     incoming_control_pdu->len =  segmented_pdu->len;
830                     incoming_control_pdu->netkey_index =  segmented_pdu->netkey_index;
831                     incoming_control_pdu->akf_aid_control = segmented_pdu->akf_aid_control;
832                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
833                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
834                     incoming_access_decrypted->seq = segmented_pdu->seq;
835                     incoming_access_decrypted->src = segmented_pdu->src;
836                     incoming_access_decrypted->dst = segmented_pdu->dst;
837 
838                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
839 
840                     // free mesh message
841                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)segmented_pdu);
842 
843                     btstack_assert(mesh_control_message_handler != NULL);
844                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
845                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
846 
847                 } else {
848 
849                     incoming_access_encrypted = (mesh_pdu_t *) segmented_pdu;
850 
851                     incoming_access_decrypted = &incoming_pdu_singleton.access;
852                     incoming_access_decrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
853                     incoming_access_decrypted->flags = segmented_pdu->flags;
854                     incoming_access_decrypted->len =  segmented_pdu->len;
855                     incoming_access_decrypted->netkey_index = segmented_pdu->netkey_index;
856                     incoming_access_decrypted->akf_aid_control =  segmented_pdu->akf_aid_control;
857                     incoming_access_decrypted->ivi_nid = segmented_pdu->ivi_nid;
858                     incoming_access_decrypted->ctl_ttl = segmented_pdu->ctl_ttl;
859                     incoming_access_decrypted->seq = segmented_pdu->seq;
860                     incoming_access_decrypted->src = segmented_pdu->src;
861                     incoming_access_decrypted->dst = segmented_pdu->dst;
862 
863                     mesh_upper_transport_process_access_message();
864                 }
865                 break;
866             default:
867                 btstack_assert(0);
868                 break;
869         }
870     }
871 
872     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
873 
874         if (crypto_active) break;
875 
876         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
877         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
878 
879         mesh_upper_transport_pdu_t * upper_pdu;
880         mesh_segmented_pdu_t * segmented_pdu;
881         uint8_t transmic_len;
882         bool ok;
883 
884         switch (pdu->pdu_type){
885             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
886                 // control pdus can go through directly
887                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
888                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
889                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
890                 break;
891             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
892                 // control pdus can go through directly
893                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
894                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
895                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
896                 break;
897             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
898                 // segmented access pdus required a mesh-segmented-pdu
899                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
900                 if (upper_pdu->lower_pdu == NULL){
901                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
902                 }
903                 if (segmented_pdu == NULL) break;
904                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
905                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
906                 // and a mesh-network-pdu for each segment in upper pdu
907                 transmic_len = ((upper_pdu->flags & MESH_TRANSPORT_FLAG_TRANSMIC_64) != 0) ? 8 : 4;
908                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + transmic_len);
909                 if (!ok) break;
910                 // all buffers available, get started
911                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
912                 mesh_upper_transport_send_access(upper_pdu);
913                 break;
914             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
915                 // unsegmented access pdus require a single mesh-network-dpu
916                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
917                 if (upper_pdu->lower_pdu == NULL){
918                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
919                 }
920                 if (upper_pdu->lower_pdu == NULL) break;
921                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
922                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
923                 break;
924             default:
925                 btstack_assert(false);
926                 break;
927         }
928     }
929 }
930 
931 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
932     btstack_linked_list_iterator_t it;
933     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
934     mesh_upper_transport_pdu_t * upper_pdu;
935     while (btstack_linked_list_iterator_has_next(&it)){
936         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
937         switch (mesh_pdu->pdu_type){
938             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
939             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
940             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
941                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
942                 if (upper_pdu->lower_pdu == pdu_to_find){
943                     btstack_linked_list_iterator_remove(&it);
944                     return upper_pdu;
945                 }
946                 break;
947             default:
948                 break;
949         }
950     }
951     return NULL;
952 }
953 
954 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
955     mesh_upper_transport_pdu_t * upper_pdu;
956     mesh_network_pdu_t * network_pdu;
957     mesh_segmented_pdu_t * segmented_pdu;
958     switch (callback_type){
959         case MESH_TRANSPORT_PDU_RECEIVED:
960             mesh_upper_transport_message_received(pdu);
961             break;
962         case MESH_TRANSPORT_PDU_SENT:
963             switch (pdu->pdu_type){
964                 case MESH_PDU_TYPE_SEGMENTED:
965                     // try to find in outgoing active
966                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
967                     btstack_assert(upper_pdu != NULL);
968                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
969                     // free chunks
970                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
971                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
972                         mesh_network_pdu_free(network_pdu);
973                     }
974                     // free segmented pdu
975                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
976                     // TODO: free segmented_pdu
977                     upper_pdu->lower_pdu = NULL;
978                     switch (upper_pdu->pdu_header.pdu_type){
979                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
980                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
981                             break;
982                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
983                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
984                             break;
985                         default:
986                             btstack_assert(false);
987                             break;
988                     }
989                     break;
990                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
991                     // find corresponding upper transport pdu and free single segment
992                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
993                     btstack_assert(upper_pdu != NULL);
994                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
995                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
996                     upper_pdu->lower_pdu = NULL;
997                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
998                     break;
999                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1000                     mesh_access_message_handler(callback_type, status, pdu);
1001                     break;
1002                 default:
1003                     btstack_assert(false);
1004                     break;
1005             }
1006             mesh_upper_transport_run();
1007             break;
1008         default:
1009             break;
1010     }
1011 }
1012 
1013 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
1014     btstack_assert(pdu != NULL);
1015     mesh_network_pdu_t   * network_pdu;
1016     mesh_segmented_pdu_t   * message_pdu;
1017     mesh_upper_transport_pdu_t * upper_pdu;
1018     switch (pdu->pdu_type) {
1019         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1020         case MESH_PDU_TYPE_NETWORK:
1021             network_pdu = (mesh_network_pdu_t *) pdu;
1022             mesh_network_pdu_free(network_pdu);
1023             break;
1024         case MESH_PDU_TYPE_SEGMENTED:
1025             message_pdu = (mesh_segmented_pdu_t *) pdu;
1026             mesh_segmented_pdu_free(message_pdu);
1027             break;
1028         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1029         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1030         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1031             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
1032             while (upper_pdu->segments) {
1033                 mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&upper_pdu->segments);
1034                 mesh_network_pdu_free(segment);
1035             }
1036             btstack_memory_mesh_upper_transport_pdu_free(upper_pdu);
1037             // check if incoming access pdu ready
1038             mesh_upper_transport_deliver_access_message();
1039             break;
1040         default:
1041             btstack_assert(false);
1042             break;
1043     }
1044 }
1045 
1046 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
1047     crypto_active = 0;
1048     switch (pdu->pdu_type){
1049         case MESH_PDU_TYPE_ACCESS:
1050             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1051         case MESH_PDU_TYPE_CONTROL:
1052             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1053             break;
1054         default:
1055             btstack_assert(0);
1056             break;
1057     }
1058 }
1059 
1060 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1061     switch (pdu->pdu_type){
1062         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1063         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1064             break;
1065         default:
1066             btstack_assert(false);
1067             break;
1068     }
1069 
1070     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1071 
1072     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1073     mesh_upper_transport_run();
1074 }
1075 
1076 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1077     switch (pdu->pdu_type){
1078         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1079             break;
1080         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1081             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1082             break;
1083         default:
1084             btstack_assert(false);
1085             break;
1086     }
1087 
1088     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1089     mesh_upper_transport_run();
1090 }
1091 
1092 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,
1093                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1094 
1095     btstack_assert(network_pdu != NULL);
1096     btstack_assert(control_pdu_len <= 11);
1097 
1098     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1099     if (!network_key) return 1;
1100 
1101     uint8_t transport_pdu_data[12];
1102     transport_pdu_data[0] = opcode;
1103     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1104     uint16_t transport_pdu_len = control_pdu_len + 1;
1105 
1106     // setup network_pdu
1107     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL;
1108     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1109 
1110     return 0;
1111 }
1112 
1113 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){
1114 
1115     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1116     if (!network_key) return 1;
1117 
1118     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1119     upper_pdu->ctl_ttl = ttl;
1120     upper_pdu->src = src;
1121     upper_pdu->dst = dest;
1122     upper_pdu->netkey_index = netkey_index;
1123     upper_pdu->akf_aid_control = opcode;
1124     return 0;
1125 }
1126 
1127 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1128                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1129 
1130     // get app or device key
1131     const mesh_transport_key_t *appkey;
1132     appkey = mesh_transport_key_get(appkey_index);
1133     if (appkey == NULL) {
1134         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1135         return 1;
1136     }
1137     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1138 
1139     // lookup network by netkey_index
1140     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1141     if (!network_key) return 1;
1142     if (network_key == NULL) {
1143         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1144         return 1;
1145     }
1146 
1147     // store in transport pdu
1148     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1149     upper_pdu->ctl_ttl = ttl;
1150     upper_pdu->src = src;
1151     upper_pdu->dst = dest;
1152     upper_pdu->netkey_index = netkey_index;
1153     upper_pdu->appkey_index = appkey_index;
1154     upper_pdu->akf_aid_control = akf_aid;
1155     if (szmic) {
1156         upper_pdu->flags |= MESH_TRANSPORT_FLAG_TRANSMIC_64;
1157     }
1158     return 0;
1159 }
1160 
1161 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1162                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1163     switch (pdu->pdu_type){
1164         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1165         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1166             return mesh_upper_transport_setup_upper_access_pdu_header((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1167                                                                appkey_index, ttl, src, dest, szmic);
1168         default:
1169             btstack_assert(false);
1170             return 1;
1171     }
1172 }
1173 
1174 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)) {
1175     mesh_access_message_handler = callback;
1176 }
1177 
1178 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)){
1179     mesh_control_message_handler = callback;
1180 }
1181 
1182 void mesh_upper_transport_init(){
1183     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1184 }
1185 
1186 bool mesh_upper_transport_message_reserve(void){
1187     if (message_builder_reserved_upper_pdu == NULL){
1188         message_builder_reserved_upper_pdu = btstack_memory_mesh_upper_transport_pdu_get();
1189     }
1190     if (message_builder_reserved_upper_pdu == NULL){
1191         return false;
1192     }
1193     while (message_builder_num_network_pdus_reserved < MESSAGE_BUILDER_MAX_NUM_NETWORK_PDUS){
1194         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
1195         if (network_pdu == NULL){
1196             return false;
1197         }
1198         btstack_linked_list_add(&message_builder_reserved_network_pdus, (btstack_linked_item_t *) network_pdu);
1199         message_builder_num_network_pdus_reserved++;
1200     }
1201     return true;
1202 }
1203 
1204 void mesh_upper_transport_message_init(mesh_upper_transport_builder_t * builder, mesh_pdu_type_t pdu_type) {
1205     btstack_assert(builder != NULL);
1206 
1207     // use reserved buffer if available
1208     if (message_builder_reserved_upper_pdu != NULL){
1209         builder->pdu = message_builder_reserved_upper_pdu;
1210         message_builder_reserved_upper_pdu = NULL;
1211     } else {
1212         builder->pdu = btstack_memory_mesh_upper_transport_pdu_get();
1213     }
1214     if (!builder->pdu) return;
1215 
1216     builder->segment = NULL;
1217     builder->pdu->pdu_header.pdu_type = pdu_type;
1218     builder->pdu->ack_opcode = MESH_ACCESS_OPCODE_NOT_SET;
1219 }
1220 
1221 
1222 void mesh_upper_transport_message_add_data(mesh_upper_transport_builder_t * builder, const uint8_t * data, uint16_t data_len){
1223     btstack_assert(builder != NULL);
1224 
1225     if (builder->pdu == NULL) return;
1226 
1227     builder->pdu->len += data_len;
1228 
1229     uint16_t bytes_current_segment = 0;
1230     if (builder->segment){
1231         bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX - builder->segment->len;
1232     }
1233     while (data_len > 0){
1234         if (bytes_current_segment == 0){
1235             // use reserved buffer if available
1236             if (message_builder_num_network_pdus_reserved > 0){
1237                 message_builder_num_network_pdus_reserved--;
1238                 builder->segment = (mesh_network_pdu_t *) btstack_linked_list_pop(&message_builder_reserved_network_pdus);
1239             } else {
1240                 builder->segment = (mesh_network_pdu_t *) mesh_network_pdu_get();
1241             }
1242             if (builder->segment == NULL) {
1243                 mesh_upper_transport_pdu_free((mesh_pdu_t *) builder->pdu);
1244                 builder->pdu = NULL;
1245                 return;
1246             }
1247             btstack_linked_list_add_tail(&builder->pdu->segments, (btstack_linked_item_t *) builder->segment);
1248             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
1249         }
1250         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, data_len);
1251         (void) memcpy(&builder->segment->data[builder->segment->len], data, bytes_to_copy);
1252         builder->segment->len += bytes_to_copy;
1253         bytes_current_segment -= bytes_to_copy;
1254         data                  += bytes_to_copy;
1255         data_len              -= bytes_to_copy;
1256     }
1257 }
1258 
1259 void mesh_upper_transport_message_add_uint8(mesh_upper_transport_builder_t * builder, uint8_t value){
1260     mesh_upper_transport_message_add_data(builder, &value, 1);
1261 }
1262 
1263 void mesh_upper_transport_message_add_uint16(mesh_upper_transport_builder_t * builder, uint16_t value){
1264     uint8_t buffer[2];
1265     little_endian_store_16(buffer, 0, value);
1266     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1267 }
1268 
1269 void mesh_upper_transport_message_add_uint24(mesh_upper_transport_builder_t * builder, uint16_t value){
1270     uint8_t buffer[3];
1271     little_endian_store_24(buffer, 0, value);
1272     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1273 }
1274 
1275 void mesh_upper_transport_message_add_uint32(mesh_upper_transport_builder_t * builder, uint16_t value){
1276     uint8_t buffer[4];
1277     little_endian_store_32(buffer, 0, value);
1278     mesh_upper_transport_message_add_data(builder, buffer, sizeof(buffer));
1279 }
1280 
1281 mesh_upper_transport_pdu_t * mesh_upper_transport_message_finalize(mesh_upper_transport_builder_t * builder){
1282     return builder->pdu;
1283 }
1284