xref: /btstack/src/mesh/mesh_upper_transport.c (revision da49152527be5afac137a4f3ef202404831eea3a)
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 #define BTSTACK_FILE__ "mesh_upper_transport.c"
39 
40 #include "mesh/mesh_upper_transport.h"
41 
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "btstack_util.h"
47 #include "btstack_memory.h"
48 #include "btstack_debug.h"
49 #include "btstack_bool.h"
50 
51 #include "mesh/beacon.h"
52 #include "mesh/mesh_iv_index_seq_number.h"
53 #include "mesh/mesh_keys.h"
54 #include "mesh/mesh_lower_transport.h"
55 #include "mesh/mesh_peer.h"
56 #include "mesh/mesh_virtual_addresses.h"
57 
58 // TODO: extract mesh_pdu functions into lower transport or network
59 #include "mesh/mesh_access.h"
60 
61 // combined key x address iterator for upper transport decryption
62 
63 typedef struct {
64     // state
65     mesh_transport_key_iterator_t  key_it;
66     mesh_virtual_address_iterator_t address_it;
67     // elements
68     const mesh_transport_key_t *   key;
69     const mesh_virtual_address_t * address;
70     // address - might be virtual
71     uint16_t dst;
72     // key info
73 } mesh_transport_key_and_virtual_address_iterator_t;
74 
75 static void mesh_upper_transport_validate_segmented_message(void);
76 static void mesh_upper_transport_run(void);
77 
78 // upper transport callbacks - in access layer
79 static void (*mesh_access_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
80 static void (*mesh_control_message_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
81 
82 //
83 static int crypto_active;
84 static uint8_t application_nonce[13];
85 static btstack_crypto_ccm_t ccm;
86 
87 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
88 
89 static mesh_access_pdu_t *   incoming_access_pdu_encrypted;
90 static mesh_access_pdu_t *   incoming_access_pdu_decrypted;
91 
92 static mesh_control_pdu_t *  incoming_control_pdu;
93 
94 static mesh_access_pdu_t     incoming_access_pdu_encrypted_singleton;
95 
96 static mesh_pdu_t *          incoming_access_encrypted;
97 
98 static union {
99     mesh_control_pdu_t    control;
100     mesh_access_pdu_t     access;
101 } incoming_pdu_singleton;
102 
103 // incoming unsegmented (network) and segmented (transport) control and access messages
104 static btstack_linked_list_t upper_transport_incoming;
105 
106 // outgoing unsegmented and segmented control and access messages
107 static btstack_linked_list_t upper_transport_outgoing;
108 
109 // outgoing upper transport messages that have been sent to lower transport and wait for sent event
110 static btstack_linked_list_t upper_transport_outgoing_active;
111 
112 // TODO: higher layer define used for assert
113 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
114 
115 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
116     printf("%-20s ", name);
117     printf_hexdump(data, len);
118 }
119 // static void mesh_print_x(const char * name, uint32_t value){
120 //     printf("%20s: 0x%x", name, (int) value);
121 // }
122 
123 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
124                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
125                                                                  uint8_t aid) {
126     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
127     // config
128     it->dst   = dst;
129     // init elements
130     it->key     = NULL;
131     it->address = NULL;
132     // init element iterators
133     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
134     // init address iterator
135     if (mesh_network_address_virtual(it->dst)){
136         mesh_virtual_address_iterator_init(&it->address_it, dst);
137         // get first key
138         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
139             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
140         }
141     }
142 }
143 
144 // cartesian product: keys x addressses
145 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
146     if (mesh_network_address_virtual(it->dst)) {
147         // find next valid entry
148         while (true){
149             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
150             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
151             // get next key
152             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
153             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
154         }
155     } else {
156         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
157     }
158 }
159 
160 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
161     if (mesh_network_address_virtual(it->dst)) {
162         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
163     } else {
164         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
165     }
166 }
167 
168 // UPPER TRANSPORT
169 
170 uint16_t mesh_access_dst(mesh_access_pdu_t * access_pdu){
171     return big_endian_read_16(access_pdu->network_header, 7);
172 }
173 
174 uint16_t mesh_access_ctl(mesh_access_pdu_t * access_pdu){
175     return access_pdu->network_header[1] >> 7;
176 }
177 
178 uint32_t mesh_access_seq(mesh_access_pdu_t * access_pdu){
179     return big_endian_read_24(access_pdu->network_header, 2);
180 }
181 
182 void mesh_access_set_nid_ivi(mesh_access_pdu_t * access_pdu, uint8_t nid_ivi){
183     access_pdu->network_header[0] = nid_ivi;
184 }
185 void mesh_access_set_ctl_ttl(mesh_access_pdu_t * access_pdu, uint8_t ctl_ttl){
186     access_pdu->network_header[1] = ctl_ttl;
187 }
188 void mesh_access_set_seq(mesh_access_pdu_t * access_pdu, uint32_t seq){
189     big_endian_store_24(access_pdu->network_header, 2, seq);
190 }
191 void mesh_access_set_src(mesh_access_pdu_t * access_pdu, uint16_t src){
192     big_endian_store_16(access_pdu->network_header, 5, src);
193 }
194 void mesh_access_set_dest(mesh_access_pdu_t * access_pdu, uint16_t dest){
195     big_endian_store_16(access_pdu->network_header, 7, dest);
196 }
197 
198 static void mesh_segmented_pdu_flatten(btstack_linked_list_t * segments, uint8_t segment_len, uint8_t * buffer) {
199     // assemble payload
200     btstack_linked_list_iterator_t it;
201     btstack_linked_list_iterator_init(&it, segments);
202     while (btstack_linked_list_iterator_has_next(&it)) {
203         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
204         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
205         // get segment n
206         uint8_t *lower_transport_pdu = mesh_network_pdu_data(segment);
207         uint8_t seg_o = (big_endian_read_16(lower_transport_pdu, 2) >> 5) & 0x001f;
208         uint8_t *segment_data = &lower_transport_pdu[4];
209         (void) memcpy(&buffer[seg_o * segment_len], segment_data, segment_len);
210     }
211 }
212 
213 static uint16_t mesh_upper_pdu_flatten(mesh_upper_transport_pdu_t * upper_pdu, uint8_t * buffer, uint16_t buffer_len) {
214     // assemble payload
215     btstack_linked_list_iterator_t it;
216     btstack_linked_list_iterator_init(&it, &upper_pdu->segments);
217     uint16_t offset = 0;
218     while (btstack_linked_list_iterator_has_next(&it)) {
219         mesh_network_pdu_t *segment = (mesh_network_pdu_t *) btstack_linked_list_iterator_next(&it);
220         btstack_assert(segment->pdu_header.pdu_type == MESH_PDU_TYPE_NETWORK);
221         btstack_assert((offset + segment->len) <= buffer_len);
222         (void) memcpy(&buffer[offset], segment->data, segment->len);
223         offset += segment->len;
224     }
225     return offset;
226 }
227 
228 // store payload in provided list of network pdus
229 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){
230     uint16_t payload_offset = 0;
231     uint16_t bytes_current_segment = 0;
232     mesh_network_pdu_t * network_pdu = NULL;
233     while (payload_offset < payload_len){
234         if (bytes_current_segment == 0){
235             network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(in_segments);
236             btstack_assert(network_pdu != NULL);
237             btstack_linked_list_add_tail(out_segments, (btstack_linked_item_t *) network_pdu);
238             bytes_current_segment = MESH_NETWORK_PAYLOAD_MAX;
239         }
240         uint16_t bytes_to_copy = btstack_min(bytes_current_segment, payload_len - payload_offset);
241         (void) memcpy(&network_pdu->data[network_pdu->len], &payload[payload_offset], bytes_to_copy);
242         bytes_current_segment -= bytes_to_copy;
243         network_pdu->len += bytes_to_copy;
244         payload_offset += bytes_to_copy;
245     }
246 }
247 
248 // tries allocate and add enough segments to store payload of given size
249 static bool mesh_segmented_allocate_segments(btstack_linked_list_t * segments, uint16_t payload_len){
250     uint16_t storage_size = btstack_linked_list_count(segments) * MESH_NETWORK_PAYLOAD_MAX;
251     while (storage_size < payload_len){
252         mesh_network_pdu_t * network_pdu = mesh_network_pdu_get();
253         if (network_pdu == NULL) break;
254         storage_size += MESH_NETWORK_PAYLOAD_MAX;
255         btstack_linked_list_add(segments, (btstack_linked_item_t *) network_pdu);
256     }
257     return (storage_size >= payload_len);
258 }
259 
260 // stub lower transport
261 
262 static void mesh_upper_transport_dump_pdus(const char *name, btstack_linked_list_t *list){
263     printf("List: %s:\n", name);
264     btstack_linked_list_iterator_t it;
265     btstack_linked_list_iterator_init(&it, list);
266     while (btstack_linked_list_iterator_has_next(&it)){
267         mesh_pdu_t * pdu = (mesh_pdu_t*) btstack_linked_list_iterator_next(&it);
268         printf("- %p\n", pdu);
269         // printf_hexdump( mesh_pdu_data(pdu), mesh_pdu_len(pdu));
270     }
271 }
272 
273 static void mesh_upper_transport_reset_pdus(btstack_linked_list_t *list){
274     while (!btstack_linked_list_empty(list)){
275         mesh_upper_transport_pdu_free((mesh_pdu_t *) btstack_linked_list_pop(list));
276     }
277 }
278 
279 void mesh_upper_transport_dump(void){
280     mesh_upper_transport_dump_pdus("upper_transport_incoming", &upper_transport_incoming);
281 }
282 
283 void mesh_upper_transport_reset(void){
284     crypto_active = 0;
285     mesh_upper_transport_reset_pdus(&upper_transport_incoming);
286 }
287 
288 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
289     // Device Key is fixed
290     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
291         return mesh_transport_key_get(appkey_index);
292     }
293 
294     // Get key refresh state from subnet
295     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
296     if (subnet == NULL) return NULL;
297 
298     // identify old and new app keys for given appkey_index
299     mesh_transport_key_t * old_key = NULL;
300     mesh_transport_key_t * new_key = NULL;
301     mesh_transport_key_iterator_t it;
302     mesh_transport_key_iterator_init(&it, netkey_index);
303     while (mesh_transport_key_iterator_has_more(&it)){
304         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
305         if (transport_key->appkey_index != appkey_index) continue;
306         if (transport_key->old_key == 0) {
307             new_key = transport_key;
308         } else {
309             old_key = transport_key;
310         }
311     }
312 
313     // if no key is marked as old, just use the current one
314     if (old_key == NULL) return new_key;
315 
316     // use new key if it exists in phase two
317     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
318         return new_key;
319     } else {
320         return old_key;
321     }
322 }
323 
324 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
325     // get IV Index and IVI
326     uint32_t iv_index = mesh_get_iv_index();
327     int ivi = ivi_nid >> 7;
328 
329     // if least significant bit differs, use previous IV Index
330     if ((iv_index & 1 ) ^ ivi){
331         iv_index--;
332     }
333     return iv_index;
334 }
335 
336 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
337     mesh_access_pdu_t * access_pdu;
338     mesh_upper_transport_pdu_t * upper_pdu;
339     switch (pdu->pdu_type){
340         case MESH_PDU_TYPE_ACCESS:
341             access_pdu = (mesh_access_pdu_t *) pdu;
342             nonce[1] = access_pdu->transmic_len == 8 ? 0x80 : 0x00;
343             (void)memcpy(&nonce[2], &access_pdu->network_header[2], 7);
344             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(access_pdu->network_header[0]));
345             break;
346         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
347         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
348             upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
349             nonce[1] = upper_pdu->transmic_len == 8 ? 0x80 : 0x00;
350             // 'network header'
351             big_endian_store_24(nonce, 2, upper_pdu->seq);
352             big_endian_store_16(nonce, 5, upper_pdu->src);
353             big_endian_store_16(nonce, 7, upper_pdu->dst);
354             big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(upper_pdu->ivi_nid));
355             break;
356         default:
357             btstack_assert(0);
358             break;
359     }
360 }
361 
362 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
363     nonce[0] = 0x01;
364     transport_segmented_setup_nonce(nonce, pdu);
365     mesh_print_hex("AppNonce", nonce, 13);
366 }
367 
368 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_pdu_t * pdu){
369     nonce[0] = 0x02;
370     transport_segmented_setup_nonce(nonce, pdu);
371     mesh_print_hex("DeviceNonce", nonce, 13);
372 }
373 
374 static void mesh_upper_transport_process_access_message_done(mesh_access_pdu_t *access_pdu){
375     crypto_active = 0;
376     btstack_assert(mesh_access_ctl(access_pdu) == 0);
377     mesh_lower_transport_message_processed_by_higher_layer(incoming_access_encrypted);
378     incoming_access_encrypted = NULL;
379     incoming_access_pdu_encrypted = NULL;
380     mesh_upper_transport_run();
381 }
382 
383 static void mesh_upper_transport_process_control_message_done(mesh_control_pdu_t * control_pdu){
384     crypto_active = 0;
385     incoming_control_pdu = NULL;
386     mesh_upper_transport_run();
387 }
388 
389 static void mesh_upper_transport_validate_segmented_message_ccm(void * arg){
390     UNUSED(arg);
391 
392     uint8_t * upper_transport_pdu     = incoming_access_pdu_decrypted->data;
393     uint8_t   upper_transport_pdu_len = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
394 
395     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
396 
397     // store TransMIC
398     uint8_t trans_mic[8];
399     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
400     mesh_print_hex("TransMIC", trans_mic, incoming_access_pdu_decrypted->transmic_len);
401 
402     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], incoming_access_pdu_decrypted->transmic_len) == 0){
403         printf("TransMIC matches\n");
404 
405         // remove TransMIC from payload
406         incoming_access_pdu_decrypted->len -= incoming_access_pdu_decrypted->transmic_len;
407 
408         // if virtual address, update dst to pseudo_dst
409         if (mesh_network_address_virtual(mesh_access_dst(incoming_access_pdu_decrypted))){
410             big_endian_store_16(incoming_access_pdu_decrypted->network_header, 7, mesh_transport_key_it.address->pseudo_dst);
411         }
412 
413         // pass to upper layer
414         btstack_assert(mesh_access_message_handler != NULL);
415         mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_access_pdu_decrypted;
416         mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
417 
418         printf("\n");
419 
420     } else {
421         uint8_t akf = incoming_access_pdu_decrypted->akf_aid_control & 0x40;
422         if (akf){
423             printf("TransMIC does not match, try next key\n");
424             mesh_upper_transport_validate_segmented_message();
425         } else {
426             printf("TransMIC does not match device key, done\n");
427             // done
428             mesh_upper_transport_process_access_message_done(incoming_access_pdu_decrypted);
429         }
430     }
431 }
432 
433 static void mesh_upper_transport_validate_segmented_message_digest(void * arg){
434     UNUSED(arg);
435     uint8_t   upper_transport_pdu_len      = incoming_access_pdu_encrypted->len - incoming_access_pdu_encrypted->transmic_len;
436     uint8_t * upper_transport_pdu_data_in  = incoming_access_pdu_encrypted->data;
437     uint8_t * upper_transport_pdu_data_out = incoming_access_pdu_decrypted->data;
438     btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_in, upper_transport_pdu_data_out, &mesh_upper_transport_validate_segmented_message_ccm, NULL);
439 }
440 
441 static void mesh_upper_transport_validate_segmented_message(void){
442     uint8_t * upper_transport_pdu_data =  incoming_access_pdu_decrypted->data;
443     uint8_t   upper_transport_pdu_len  = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
444 
445     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
446         printf("No valid transport key found\n");
447         mesh_upper_transport_process_access_message_done(incoming_access_pdu_decrypted);
448         return;
449     }
450     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
451     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
452 
453     if (message_key->akf){
454         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) incoming_access_pdu_encrypted);
455     } else {
456         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) incoming_access_pdu_encrypted);
457     }
458 
459     // store application / device key index
460     mesh_print_hex("AppOrDevKey", message_key->key, 16);
461     incoming_access_pdu_decrypted->appkey_index = message_key->appkey_index;
462 
463     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
464 
465     // decrypt ccm
466     crypto_active = 1;
467     uint16_t aad_len  = 0;
468     if (mesh_network_address_virtual(mesh_access_dst(incoming_access_pdu_decrypted))){
469         aad_len  = 16;
470     }
471     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, incoming_access_pdu_decrypted->transmic_len);
472 
473     if (aad_len){
474         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_segmented_message_digest, NULL);
475     } else {
476         mesh_upper_transport_validate_segmented_message_digest(NULL);
477     }
478 }
479 
480 static void mesh_upper_transport_process_segmented_message(void){
481     // copy original pdu
482     (void)memcpy(incoming_access_pdu_decrypted, incoming_access_pdu_encrypted,
483                  sizeof(mesh_access_pdu_t));
484 
485     //
486     uint8_t * upper_transport_pdu     =  incoming_access_pdu_decrypted->data;
487     uint8_t   upper_transport_pdu_len = incoming_access_pdu_decrypted->len - incoming_access_pdu_decrypted->transmic_len;
488     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
489 
490     uint8_t aid = incoming_access_pdu_decrypted->akf_aid_control & 0x3f;
491     uint8_t akf = (incoming_access_pdu_decrypted->akf_aid_control & 0x40) >> 6;
492 
493     printf("AKF: %u\n",   akf);
494     printf("AID: %02x\n", aid);
495 
496     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_access_dst(incoming_access_pdu_decrypted),
497                                                          incoming_access_pdu_decrypted->netkey_index, akf, aid);
498     mesh_upper_transport_validate_segmented_message();
499 }
500 
501 static void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
502     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
503     mesh_upper_transport_run();
504 }
505 
506 static void mesh_upper_transport_send_access_segmented(mesh_upper_transport_pdu_t * upper_pdu){
507 
508     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
509     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
510 
511     // convert mesh_access_pdu_t into mesh_segmented_pdu_t
512     btstack_linked_list_t free_segments = segmented_pdu->segments;
513     segmented_pdu->segments = NULL;
514     mesh_segmented_store_payload(incoming_pdu_singleton.access.data, upper_pdu->len, &free_segments, &segmented_pdu->segments);
515 
516     // copy meta
517     segmented_pdu->len = upper_pdu->len;
518     segmented_pdu->netkey_index = upper_pdu->netkey_index;
519     segmented_pdu->transmic_len = upper_pdu->transmic_len;
520     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
521     segmented_pdu->flags = upper_pdu->flags;
522 
523     // setup segmented_pdu header
524     // (void)memcpy(segmented_pdu->network_header, upper_pdu->network_header, 9);
525     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
526     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
527     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
528     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
529     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
530     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
531 
532     // queue up
533     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
534     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
535 
536     mesh_lower_transport_send_pdu((mesh_pdu_t*) segmented_pdu);
537 }
538 
539 static void mesh_upper_transport_send_access_unsegmented(mesh_upper_transport_pdu_t * upper_pdu){
540 
541     // provide segment
542     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) upper_pdu->lower_pdu;
543 
544     // setup network pdu
545     network_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS;
546     network_pdu->data[0] = upper_pdu->ivi_nid;
547     network_pdu->data[1] = upper_pdu->ctl_ttl;
548     big_endian_store_24(network_pdu->data, 2, upper_pdu->seq);
549     big_endian_store_16(network_pdu->data, 5, upper_pdu->src);
550     big_endian_store_16(network_pdu->data, 7, upper_pdu->dst);
551     network_pdu->netkey_index = upper_pdu->netkey_index;
552 
553     // setup access message
554     network_pdu->data[9] = upper_pdu->akf_aid_control;
555     btstack_assert(upper_pdu->len < 15);
556     (void)memcpy(&network_pdu->data[10], &incoming_pdu_singleton.access.data, upper_pdu->len);
557     network_pdu->len = 10 + upper_pdu->len;
558     network_pdu->flags = 0;
559 
560     // queue up
561     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
562 
563     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
564 }
565 
566 static void mesh_upper_transport_send_access_ccm(void * arg){
567     crypto_active = 0;
568 
569     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
570     mesh_print_hex("EncAccessPayload", incoming_pdu_singleton.access.data, upper_pdu->len);
571     // store TransMIC
572     btstack_crypto_ccm_get_authentication_value(&ccm, &incoming_pdu_singleton.access.data[upper_pdu->len]);
573     mesh_print_hex("TransMIC", &incoming_pdu_singleton.access.data[upper_pdu->len], upper_pdu->transmic_len);
574     upper_pdu->len += upper_pdu->transmic_len;
575     mesh_print_hex("UpperTransportPDU", incoming_pdu_singleton.access.data, upper_pdu->len);
576     switch (upper_pdu->pdu_header.pdu_type){
577         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
578             mesh_upper_transport_send_access_unsegmented(upper_pdu);
579             break;
580         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
581             mesh_upper_transport_send_access_segmented(upper_pdu);
582             break;
583         default:
584             btstack_assert(false);
585     }
586 }
587 
588 static void mesh_upper_transport_send_access_digest(void *arg){
589     mesh_upper_transport_pdu_t * upper_pdu = (mesh_upper_transport_pdu_t *) arg;
590     uint16_t  access_pdu_len  = upper_pdu->len;
591     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, incoming_pdu_singleton.access.data, incoming_pdu_singleton.access.data,
592                                      &mesh_upper_transport_send_access_ccm, upper_pdu);
593 }
594 
595 static void mesh_upper_transport_send_access(mesh_upper_transport_pdu_t * upper_pdu){
596 
597     // if dst is virtual address, lookup label uuid and hash
598     uint16_t aad_len = 0;
599     mesh_virtual_address_t * virtual_address = NULL;
600     if (mesh_network_address_virtual(upper_pdu->dst)){
601         virtual_address = mesh_virtual_address_for_pseudo_dst(upper_pdu->dst);
602         if (!virtual_address){
603             printf("No virtual address register for pseudo dst %4x\n", upper_pdu->dst);
604             mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
605             return;
606         }
607         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
608         // printf_hexdump(virtual_address->label_uuid, 16);
609         aad_len = 16;
610         upper_pdu->dst = virtual_address->hash;
611     }
612 
613     // get app or device key
614     uint16_t appkey_index = upper_pdu->appkey_index;
615     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(upper_pdu->netkey_index, appkey_index);
616     if (appkey == NULL){
617         printf("AppKey %04x not found, drop message\n", appkey_index);
618         mesh_access_message_handler(MESH_TRANSPORT_PDU_SENT, MESH_TRANSPORT_STATUS_SEND_FAILED, (mesh_pdu_t *) upper_pdu);
619         return;
620     }
621 
622     // reserve slot
623     mesh_lower_transport_reserve_slot();
624 
625     // reserve one sequence number, which is also used to encrypt access payload
626     uint32_t seq = mesh_sequence_number_next();
627     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
628     upper_pdu->seq = seq;
629 
630     // also reserves crypto_buffer
631     crypto_active = 1;
632 
633     // flatten segmented pdu into crypto buffer
634     uint16_t payload_len = mesh_upper_pdu_flatten(upper_pdu, incoming_pdu_singleton.access.data, sizeof(incoming_pdu_singleton.access.data));
635     btstack_assert(payload_len == upper_pdu->len);
636 
637     // Dump PDU
638     printf("[+] Upper transport, send upper (un)segmented Access PDU - dest %04x, seq %06x\n", upper_pdu->dst, upper_pdu->seq);
639     mesh_print_hex("Access Payload", incoming_pdu_singleton.access.data, upper_pdu->len);
640 
641     // setup nonce - uses dst, so after pseudo address translation
642     if (appkey_index == MESH_DEVICE_KEY_INDEX){
643         transport_segmented_setup_device_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
644     } else {
645         transport_segmented_setup_application_nonce(application_nonce, (mesh_pdu_t *) upper_pdu);
646     }
647 
648     // Dump key
649     mesh_print_hex("AppOrDevKey", appkey->key, 16);
650 
651     // encrypt ccm
652     uint8_t   transmic_len    = upper_pdu->transmic_len;
653     uint16_t  access_pdu_len  = upper_pdu->len;
654     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
655     if (virtual_address){
656         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
657         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16,
658                                   &mesh_upper_transport_send_access_digest, upper_pdu);
659     } else {
660         mesh_upper_transport_send_access_digest(upper_pdu);
661     }
662 }
663 
664 static void mesh_upper_transport_send_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu){
665     // reserve slot
666     mesh_lower_transport_reserve_slot();
667     // reserve sequence number
668     uint32_t seq = mesh_sequence_number_next();
669     mesh_network_pdu_set_seq(network_pdu, seq);
670     // Dump PDU
671     uint8_t opcode = network_pdu->data[9];
672     printf("[+] Upper transport, send unsegmented Control PDU %p - seq %06x opcode %02x\n", network_pdu, seq, opcode);
673     mesh_print_hex("Access Payload", &network_pdu->data[10], network_pdu->len - 10);
674 
675     // send
676      mesh_lower_transport_send_pdu((mesh_pdu_t *) network_pdu);
677 }
678 
679 static void mesh_upper_transport_send_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu){
680     // reserve slot
681     mesh_lower_transport_reserve_slot();
682     // reserve sequence number
683     uint32_t seq = mesh_sequence_number_next();
684     upper_pdu->flags |= MESH_TRANSPORT_FLAG_SEQ_RESERVED;
685     upper_pdu->seq = seq;
686     // Dump PDU
687     // uint8_t opcode = upper_pdu->data[0];
688     // printf("[+] Upper transport, send segmented Control PDU %p - seq %06x opcode %02x\n", upper_pdu, seq, opcode);
689     // mesh_print_hex("Access Payload", &upper_pdu->data[1], upper_pdu->len - 1);
690     // send
691     mesh_segmented_pdu_t * segmented_pdu   = (mesh_segmented_pdu_t *) upper_pdu->lower_pdu;
692     segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
693 
694     // lend segments to lower transport pdu
695     segmented_pdu->segments = upper_pdu->segments;
696     upper_pdu->segments = NULL;
697 
698     // copy meta
699     segmented_pdu->len = upper_pdu->len;
700     segmented_pdu->netkey_index = upper_pdu->netkey_index;
701     segmented_pdu->transmic_len = 0;   // no TransMIC for control
702     segmented_pdu->akf_aid_control = upper_pdu->akf_aid_control;
703     segmented_pdu->flags = upper_pdu->flags;
704 
705     // setup segmented_pdu header
706     // TODO: use fields in mesh_segmented_pdu_t and setup network header in lower transport
707     segmented_pdu->network_header[0] = upper_pdu->ivi_nid;
708     segmented_pdu->network_header[1] = upper_pdu->ctl_ttl;
709     big_endian_store_24(segmented_pdu->network_header, 2, upper_pdu->seq);
710     big_endian_store_16(segmented_pdu->network_header, 5, upper_pdu->src);
711     big_endian_store_16(segmented_pdu->network_header, 7, upper_pdu->dst);
712 
713     // queue up
714     upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
715     btstack_linked_list_add(&upper_transport_outgoing_active, (btstack_linked_item_t *) upper_pdu);
716 
717     mesh_lower_transport_send_pdu((mesh_pdu_t *) segmented_pdu);
718 }
719 
720 static void mesh_upper_transport_run(void){
721 
722     while(!btstack_linked_list_empty(&upper_transport_incoming)){
723 
724         if (crypto_active) return;
725 
726         // get next message
727         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_pop(&upper_transport_incoming);
728         mesh_network_pdu_t   * network_pdu;
729         mesh_segmented_pdu_t   * message_pdu;
730         switch (pdu->pdu_type){
731             case MESH_PDU_TYPE_UNSEGMENTED:
732                 network_pdu = (mesh_network_pdu_t *) pdu;
733                 // control?
734                 if (mesh_network_control(network_pdu)) {
735 
736                     incoming_control_pdu =  &incoming_pdu_singleton.control;
737                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
738                     incoming_control_pdu->len =  network_pdu->len;
739                     incoming_control_pdu->netkey_index =  network_pdu->netkey_index;
740 
741                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
742 
743                     incoming_control_pdu->akf_aid_control = lower_transport_pdu[0];
744                     incoming_control_pdu->len = network_pdu->len - 10; // 9 header + 1 opcode
745                     (void)memcpy(incoming_control_pdu->data, &lower_transport_pdu[1], incoming_control_pdu->len);
746 
747                     // copy meta data into encrypted pdu buffer
748                     (void)memcpy(incoming_control_pdu->network_header, network_pdu->data, 9);
749 
750                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
751 
752                     // free mesh message
753                     mesh_lower_transport_message_processed_by_higher_layer(pdu);
754 
755                     btstack_assert(mesh_control_message_handler != NULL);
756                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
757                     mesh_control_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
758 
759                 } else {
760 
761                     incoming_access_encrypted = (mesh_pdu_t *) network_pdu;
762 
763                     incoming_access_pdu_encrypted = &incoming_access_pdu_encrypted_singleton;
764                     incoming_access_pdu_encrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
765                     incoming_access_pdu_decrypted = &incoming_pdu_singleton.access;
766 
767                     incoming_access_pdu_encrypted->netkey_index = network_pdu->netkey_index;
768                     incoming_access_pdu_encrypted->transmic_len = 4;
769 
770                     uint8_t * lower_transport_pdu = mesh_network_pdu_data(network_pdu);
771 
772                     incoming_access_pdu_encrypted->akf_aid_control = lower_transport_pdu[0];
773                     incoming_access_pdu_encrypted->len = network_pdu->len - 10; // 9 header + 1 AID
774                     (void)memcpy(incoming_access_pdu_encrypted->data, &lower_transport_pdu[1], incoming_access_pdu_encrypted->len);
775 
776                     // copy meta data into encrypted pdu buffer
777                     (void)memcpy(incoming_access_pdu_encrypted->network_header, network_pdu->data, 9);
778 
779                     mesh_print_hex("Assembled payload", incoming_access_pdu_encrypted->data, incoming_access_pdu_encrypted->len);
780 
781                     // get encoded transport pdu and start processing
782                     mesh_upper_transport_process_segmented_message();
783                 }
784                 break;
785             case MESH_PDU_TYPE_SEGMENTED:
786                 message_pdu = (mesh_segmented_pdu_t *) pdu;
787                 uint8_t ctl = mesh_message_ctl(message_pdu);
788                 if (ctl){
789                     incoming_control_pdu=  &incoming_pdu_singleton.control;
790                     incoming_control_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_CONTROL;
791 
792                     // flatten
793                     mesh_segmented_pdu_flatten(&message_pdu->segments, 8, incoming_control_pdu->data);
794 
795                     // copy meta data into encrypted pdu buffer
796                     incoming_control_pdu->len =  message_pdu->len;
797                     incoming_control_pdu->netkey_index =  message_pdu->netkey_index;
798                     incoming_control_pdu->akf_aid_control =  message_pdu->akf_aid_control;
799                     incoming_control_pdu->flags = 0;
800                     (void)memcpy(incoming_control_pdu->network_header, message_pdu->network_header, 9);
801 
802                     mesh_print_hex("Assembled payload", incoming_control_pdu->data, incoming_control_pdu->len);
803 
804                     // free mesh message
805                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)message_pdu);
806 
807                     btstack_assert(mesh_control_message_handler != NULL);
808                     mesh_pdu_t * pdu = (mesh_pdu_t*) incoming_control_pdu;
809                     mesh_access_message_handler(MESH_TRANSPORT_PDU_RECEIVED, MESH_TRANSPORT_STATUS_SUCCESS, pdu);
810 
811                 } else {
812 
813                     incoming_access_encrypted = (mesh_pdu_t *) message_pdu;
814 
815                     incoming_access_pdu_encrypted = &incoming_access_pdu_encrypted_singleton;
816                     incoming_access_pdu_encrypted->pdu_header.pdu_type = MESH_PDU_TYPE_ACCESS;
817                     incoming_access_pdu_decrypted = &incoming_pdu_singleton.access;
818 
819                     // flatten
820                     mesh_segmented_pdu_flatten(&message_pdu->segments, 12, incoming_access_pdu_encrypted->data);
821 
822                     // copy meta data into encrypted pdu buffer
823                     incoming_access_pdu_encrypted->len =  message_pdu->len;
824                     incoming_access_pdu_encrypted->netkey_index =  message_pdu->netkey_index;
825                     incoming_access_pdu_encrypted->transmic_len =  message_pdu->transmic_len;
826                     incoming_access_pdu_encrypted->akf_aid_control =  message_pdu->akf_aid_control;
827                     (void)memcpy(incoming_access_pdu_encrypted->network_header, message_pdu->network_header, 9);
828 
829                     mesh_print_hex("Assembled payload", incoming_access_pdu_encrypted->data, incoming_access_pdu_encrypted->len);
830 
831                     // get encoded transport pdu and start processing
832                     mesh_upper_transport_process_segmented_message();
833                 }
834                 break;
835             default:
836                 btstack_assert(0);
837                 break;
838         }
839     }
840 
841     while (!btstack_linked_list_empty(&upper_transport_outgoing)){
842 
843         if (crypto_active) break;
844 
845         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_outgoing);
846         if (mesh_lower_transport_can_send_to_dest(mesh_pdu_dst(pdu)) == 0) break;
847 
848         mesh_upper_transport_pdu_t * upper_pdu;
849         mesh_segmented_pdu_t * segmented_pdu;
850         bool ok;
851 
852         switch (pdu->pdu_type){
853             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
854                 // control pdus can go through directly
855                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
856                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
857                 mesh_upper_transport_send_unsegmented_control_pdu((mesh_network_pdu_t *) pdu);
858                 break;
859             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
860                 // control pdus can go through directly
861                 btstack_assert(mesh_pdu_ctl(pdu) != 0);
862                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
863                 mesh_upper_transport_send_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu);
864                 break;
865             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
866                 // segmented access pdus required a mesh-segmented-pdu
867                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
868                 if (upper_pdu->lower_pdu == NULL){
869                     segmented_pdu = btstack_memory_mesh_segmented_pdu_get();
870                 }
871                 if (segmented_pdu == NULL) break;
872                 upper_pdu->lower_pdu = (mesh_pdu_t *) segmented_pdu;
873                 segmented_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_SEGMENTED;
874                 // and a mesh-network-pdu for each segment in upper pdu
875                 ok = mesh_segmented_allocate_segments(&segmented_pdu->segments, upper_pdu->len + upper_pdu->transmic_len);
876                 if (!ok) break;
877                 // all buffers available, get started
878                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
879                 mesh_upper_transport_send_access(upper_pdu);
880                 break;
881             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
882                 // unsegmented access pdus require a single mesh-network-dpu
883                 upper_pdu = (mesh_upper_transport_pdu_t *) pdu;
884                 if (upper_pdu->lower_pdu == NULL){
885                     upper_pdu->lower_pdu = (mesh_pdu_t *) mesh_network_pdu_get();
886                 }
887                 if (upper_pdu->lower_pdu == NULL) break;
888                 (void) btstack_linked_list_pop(&upper_transport_outgoing);
889                 mesh_upper_transport_send_access((mesh_upper_transport_pdu_t *) pdu);
890                 break;
891             default:
892                 btstack_assert(false);
893                 break;
894         }
895     }
896 }
897 
898 static mesh_upper_transport_pdu_t * mesh_upper_transport_find_pdu_for_lower(mesh_pdu_t * pdu_to_find){
899     btstack_linked_list_iterator_t it;
900     btstack_linked_list_iterator_init(&it, &upper_transport_outgoing_active);
901     mesh_upper_transport_pdu_t * upper_pdu;
902     while (btstack_linked_list_iterator_has_next(&it)){
903         mesh_pdu_t * mesh_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&it);
904         switch (mesh_pdu->pdu_type){
905             case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
906             case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
907             case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
908                 upper_pdu = (mesh_upper_transport_pdu_t *) mesh_pdu;
909                 if (upper_pdu->lower_pdu == pdu_to_find){
910                     btstack_linked_list_iterator_remove(&it);
911                     return upper_pdu;
912                 }
913                 break;
914             default:
915                 break;
916         }
917     }
918     return NULL;
919 }
920 
921 static void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
922     mesh_upper_transport_pdu_t * upper_pdu;
923     mesh_network_pdu_t * network_pdu;
924     mesh_segmented_pdu_t * segmented_pdu;
925     switch (callback_type){
926         case MESH_TRANSPORT_PDU_RECEIVED:
927             mesh_upper_transport_message_received(pdu);
928             break;
929         case MESH_TRANSPORT_PDU_SENT:
930             switch (pdu->pdu_type){
931                 case MESH_PDU_TYPE_SEGMENTED:
932                     // try to find in outgoing active
933                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
934                     btstack_assert(upper_pdu != NULL);
935                     segmented_pdu = (mesh_segmented_pdu_t *) pdu;
936                     // free chunks
937                     while (!btstack_linked_list_empty(&segmented_pdu->segments)){
938                         mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) btstack_linked_list_pop(&segmented_pdu->segments);
939                         mesh_network_pdu_free(network_pdu);
940                     }
941                     // free segmented pdu
942                     btstack_memory_mesh_segmented_pdu_free(segmented_pdu);
943                     // TODO: free segmented_pdu
944                     upper_pdu->lower_pdu = NULL;
945                     switch (upper_pdu->pdu_header.pdu_type){
946                         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
947                             mesh_control_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
948                             break;
949                         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
950                             mesh_access_message_handler(callback_type, status, (mesh_pdu_t *) upper_pdu);
951                             break;
952                         default:
953                             btstack_assert(false);
954                             break;
955                     }
956                     break;
957                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
958                     // find corresponding upper transport pdu and free single segment
959                     upper_pdu = mesh_upper_transport_find_pdu_for_lower(pdu);
960                     btstack_assert(upper_pdu != NULL);
961                     btstack_assert(upper_pdu->lower_pdu == (mesh_pdu_t *) pdu);
962                     mesh_network_pdu_free((mesh_network_pdu_t *) pdu);
963                     upper_pdu->lower_pdu = NULL;
964                     mesh_access_message_handler(callback_type, status, (mesh_pdu_t*) upper_pdu);
965                     break;
966                 case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
967                     mesh_access_message_handler(callback_type, status, pdu);
968                     break;
969                 default:
970                     btstack_assert(false);
971                     break;
972             }
973             mesh_upper_transport_run();
974             break;
975         default:
976             break;
977     }
978 }
979 
980 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
981     mesh_network_pdu_t   * network_pdu;
982     mesh_segmented_pdu_t   * message_pdu;
983     switch (pdu->pdu_type) {
984         case MESH_PDU_TYPE_NETWORK:
985             network_pdu = (mesh_network_pdu_t *) pdu;
986             mesh_network_pdu_free(network_pdu);
987             break;
988         case MESH_PDU_TYPE_SEGMENTED:
989             message_pdu = (mesh_segmented_pdu_t *) pdu;
990             mesh_message_pdu_free(message_pdu);
991         default:
992             btstack_assert(false);
993             break;
994     }
995 }
996 
997 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
998     crypto_active = 0;
999     switch (pdu->pdu_type){
1000         case MESH_PDU_TYPE_ACCESS:
1001             mesh_upper_transport_process_access_message_done((mesh_access_pdu_t *) pdu);
1002         case MESH_PDU_TYPE_CONTROL:
1003             mesh_upper_transport_process_control_message_done((mesh_control_pdu_t *) pdu);
1004             break;
1005         default:
1006             btstack_assert(0);
1007             break;
1008     }
1009 }
1010 
1011 void mesh_upper_transport_send_access_pdu(mesh_pdu_t *pdu){
1012     switch (pdu->pdu_type){
1013         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1014         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1015             break;
1016         default:
1017             btstack_assert(false);
1018             break;
1019     }
1020 
1021     btstack_assert(((mesh_upper_transport_pdu_t *) pdu)->lower_pdu == NULL);
1022 
1023     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1024     mesh_upper_transport_run();
1025 }
1026 
1027 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
1028     switch (pdu->pdu_type){
1029         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1030             break;
1031         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1032             btstack_assert( ((mesh_network_pdu_t *) pdu)->len >= 9);
1033             break;
1034         default:
1035             btstack_assert(false);
1036             break;
1037     }
1038 
1039     btstack_linked_list_add_tail(&upper_transport_outgoing, (btstack_linked_item_t*) pdu);
1040     mesh_upper_transport_run();
1041 }
1042 
1043 static 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,
1044                                                                   const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1045 
1046     if (control_pdu_len > 11) return 1;
1047 
1048     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1049     if (!network_key) return 1;
1050 
1051     uint8_t transport_pdu_data[12];
1052     transport_pdu_data[0] = opcode;
1053     (void)memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
1054     uint16_t transport_pdu_len = control_pdu_len + 1;
1055 
1056     // setup network_pdu
1057     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, 0, src, dest, transport_pdu_data, transport_pdu_len);
1058 
1059     return 0;
1060 }
1061 
1062 static uint8_t mesh_upper_transport_setup_segmented_control_pdu(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
1063                                                                 const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1064 
1065     if (control_pdu_len > 256) return 1;
1066 
1067     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
1068     if (!network_key) return 1;
1069 
1070     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1071     upper_pdu->ctl_ttl = ttl;
1072     upper_pdu->src = src;
1073     upper_pdu->dst = dest;
1074     upper_pdu->transmic_len = 0;    // no TransMIC for control
1075     upper_pdu->netkey_index = netkey_index;
1076     upper_pdu->akf_aid_control = opcode;
1077 
1078     // allocate segments
1079     btstack_linked_list_t free_segments = NULL;
1080     bool ok = mesh_segmented_allocate_segments( &free_segments, control_pdu_len);
1081     if (!ok) return 1;
1082     // store control pdu
1083     mesh_segmented_store_payload(control_pdu_data, control_pdu_len, &free_segments, &upper_pdu->segments);
1084     upper_pdu->len = control_pdu_len;
1085     return 0;
1086 }
1087 
1088 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
1089                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
1090     switch (pdu->pdu_type){
1091         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_CONTROL:
1092             return mesh_upper_transport_setup_unsegmented_control_pdu((mesh_network_pdu_t *) pdu, netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
1093         case MESH_PDU_TYPE_UPPER_SEGMENTED_CONTROL:
1094             return mesh_upper_transport_setup_segmented_control_pdu((mesh_upper_transport_pdu_t *) pdu,  netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
1095         default:
1096             btstack_assert(0);
1097             return 1;
1098     }
1099 }
1100 
1101 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_access_pdu_t * access_pdu, uint16_t netkey_index,
1102                                                                       uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1103 
1104     // get app or device key
1105     const mesh_transport_key_t *appkey;
1106     appkey = mesh_transport_key_get(appkey_index);
1107     if (appkey == NULL) {
1108         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1109         return 1;
1110     }
1111     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1112 
1113     // lookup network by netkey_index
1114     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1115     if (!network_key) return 1;
1116     if (network_key == NULL) {
1117         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1118         return 1;
1119     }
1120 
1121     const uint8_t trans_mic_len = szmic ? 8 : 4;
1122 
1123     // store in transport pdu
1124     access_pdu->transmic_len = trans_mic_len;
1125     access_pdu->netkey_index = netkey_index;
1126     access_pdu->appkey_index = appkey_index;
1127     access_pdu->akf_aid_control = akf_aid;
1128     mesh_access_set_nid_ivi(access_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
1129     mesh_access_set_src(access_pdu, src);
1130     mesh_access_set_dest(access_pdu, dest);
1131     mesh_access_set_ctl_ttl(access_pdu, ttl);
1132     return 0;
1133 }
1134 
1135 static uint8_t mesh_upper_transport_setup_upper_access_pdu_header(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index,
1136                                                                   uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1137 
1138     // get app or device key
1139     const mesh_transport_key_t *appkey;
1140     appkey = mesh_transport_key_get(appkey_index);
1141     if (appkey == NULL) {
1142         printf("[!] Upper transport, setup segmented Access PDU - appkey_index %x unknown\n", appkey_index);
1143         return 1;
1144     }
1145     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
1146 
1147     // lookup network by netkey_index
1148     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
1149     if (!network_key) return 1;
1150     if (network_key == NULL) {
1151         printf("[!] Upper transport, setup segmented Access PDU - netkey_index %x unknown\n", appkey_index);
1152         return 1;
1153     }
1154 
1155     const uint8_t trans_mic_len = szmic ? 8 : 4;
1156 
1157     // store in transport pdu
1158     upper_pdu->ivi_nid = network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7);
1159     upper_pdu->ctl_ttl = ttl;
1160     upper_pdu->src = src;
1161     upper_pdu->dst = dest;
1162     upper_pdu->transmic_len = trans_mic_len;
1163     upper_pdu->netkey_index = netkey_index;
1164     upper_pdu->appkey_index = appkey_index;
1165     upper_pdu->akf_aid_control = akf_aid;
1166     return 0;
1167 }
1168 
1169 static uint8_t mesh_upper_transport_setup_upper_access_pdu(mesh_upper_transport_pdu_t * upper_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
1170                                                            uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1171     int status = mesh_upper_transport_setup_upper_access_pdu_header(upper_pdu, netkey_index, appkey_index, ttl, src,
1172                                                                     dest, szmic);
1173     if (status) return status;
1174 
1175     // allocate segments
1176     btstack_linked_list_t free_segments = NULL;
1177     bool ok = mesh_segmented_allocate_segments( &free_segments, access_pdu_len);
1178     if (!ok) return 1;
1179     // store control pdu
1180     mesh_segmented_store_payload(access_pdu_data, access_pdu_len, &free_segments, &upper_pdu->segments);
1181     upper_pdu->len = access_pdu_len;
1182     return 0;
1183 }
1184 
1185 
1186 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1187                                                      uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
1188     switch (pdu->pdu_type){
1189         case MESH_PDU_TYPE_ACCESS:
1190             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_access_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
1191         default:
1192             btstack_assert(false);
1193             return 1;
1194     }
1195 }
1196 
1197 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
1198                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
1199                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
1200     switch (pdu->pdu_type){
1201         case MESH_PDU_TYPE_UPPER_SEGMENTED_ACCESS:
1202         case MESH_PDU_TYPE_UPPER_UNSEGMENTED_ACCESS:
1203             return mesh_upper_transport_setup_upper_access_pdu((mesh_upper_transport_pdu_t *) pdu, netkey_index,
1204                                                                appkey_index, ttl, src, dest, szmic, access_pdu_data,
1205                                                                access_pdu_len);
1206         default:
1207             btstack_assert(false);
1208             return 1;
1209     }
1210 }
1211 
1212 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)) {
1213     mesh_access_message_handler = callback;
1214 }
1215 
1216 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)){
1217     mesh_control_message_handler = callback;
1218 }
1219 
1220 void mesh_upper_transport_init(){
1221     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
1222 }
1223