1 /******************************************************************************
2 *
3 * Copyright (C) 2010-2014 Broadcom Corporation
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 ******************************************************************************/
18
19 /******************************************************************************
20 *
21 * This file contains source code for some utility functions to help parse
22 * and build NFC Data Exchange Format (NDEF) messages
23 *
24 ******************************************************************************/
25 #include "ndef_utils.h"
26
27 #include <log/log.h>
28 #include <string.h>
29
30 /*******************************************************************************
31 **
32 ** Static Local Functions
33 **
34 *******************************************************************************/
35
36 /*******************************************************************************
37 **
38 ** Function shiftdown
39 **
40 ** Description shift memory down (to make space to insert a record)
41 **
42 *******************************************************************************/
shiftdown(uint8_t * p_mem,uint32_t len,uint32_t shift_amount)43 static void shiftdown(uint8_t* p_mem, uint32_t len, uint32_t shift_amount) {
44 uint8_t* ps = p_mem + len - 1;
45 uint8_t* pd = ps + shift_amount;
46 uint32_t xx;
47
48 for (xx = 0; xx < len; xx++) *pd-- = *ps--;
49 }
50
51 /*******************************************************************************
52 **
53 ** Function shiftup
54 **
55 ** Description shift memory up (to delete a record)
56 **
57 *******************************************************************************/
shiftup(uint8_t * p_dest,uint8_t * p_src,uint32_t len)58 static void shiftup(uint8_t* p_dest, uint8_t* p_src, uint32_t len) {
59 uint8_t* ps = p_src;
60 uint8_t* pd = p_dest;
61 uint32_t xx;
62
63 for (xx = 0; xx < len; xx++) *pd++ = *ps++;
64 }
65
66 /*******************************************************************************
67 **
68 ** Function NDEF_MsgValidate
69 **
70 ** Description This function validates an NDEF message.
71 **
72 ** Returns TRUE if all OK, or FALSE if the message is invalid.
73 **
74 *******************************************************************************/
NDEF_MsgValidate(uint8_t * p_msg,uint32_t msg_len,bool b_allow_chunks)75 tNDEF_STATUS NDEF_MsgValidate(uint8_t* p_msg, uint32_t msg_len,
76 bool b_allow_chunks) {
77 uint8_t* p_rec = p_msg;
78 uint8_t* p_end = p_msg + msg_len;
79 uint8_t* p_new;
80 uint8_t rec_hdr = 0, type_len, id_len;
81 int count;
82 uint32_t payload_len;
83 bool bInChunk = false;
84
85 if ((p_msg == nullptr) || (msg_len < 3)) return (NDEF_MSG_TOO_SHORT);
86
87 /* The first record must have the MB bit set */
88 if ((*p_msg & NDEF_MB_MASK) == 0) return (NDEF_MSG_NO_MSG_BEGIN);
89
90 /* The first record cannot be a chunk */
91 if ((*p_msg & NDEF_TNF_MASK) == NDEF_TNF_UNCHANGED)
92 return (NDEF_MSG_UNEXPECTED_CHUNK);
93
94 for (count = 0; p_rec < p_end; count++) {
95 /* if less than short record header */
96 if (p_rec + 3 > p_end) return (NDEF_MSG_TOO_SHORT);
97
98 rec_hdr = *p_rec++;
99
100 /* header should have a valid TNF */
101 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_MASK)
102 return NDEF_MSG_INVALID_CHUNK;
103
104 /* The second and all subsequent records must NOT have the MB bit set */
105 if ((count > 0) && (rec_hdr & NDEF_MB_MASK))
106 return (NDEF_MSG_EXTRA_MSG_BEGIN);
107
108 /* Type field length */
109 type_len = *p_rec++;
110
111 /* If the record is chunked, first record must contain the type unless
112 * it's Type Name Format is Unknown */
113 if ((rec_hdr & NDEF_CF_MASK) && (rec_hdr & NDEF_MB_MASK) && type_len == 0 &&
114 (rec_hdr & NDEF_TNF_MASK) != NDEF_TNF_UNKNOWN)
115 return (NDEF_MSG_INVALID_CHUNK);
116
117 /* Payload length - can be 1 or 4 bytes */
118 if (rec_hdr & NDEF_SR_MASK)
119 payload_len = *p_rec++;
120 else {
121 /* if less than 4 bytes payload length */
122 if (p_rec + 4 > p_end) return (NDEF_MSG_TOO_SHORT);
123
124 BE_STREAM_TO_UINT32(payload_len, p_rec);
125 }
126
127 /* ID field Length */
128 if (rec_hdr & NDEF_IL_MASK) {
129 /* if less than 1 byte ID field length */
130 if (p_rec + 1 > p_end) return (NDEF_MSG_TOO_SHORT);
131
132 id_len = *p_rec++;
133 } else {
134 id_len = 0;
135 /* Empty record must have the id_len */
136 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_EMPTY)
137 return (NDEF_MSG_INVALID_EMPTY_REC);
138 }
139
140 /* A chunk must have type "unchanged", and no type or ID fields */
141 if (rec_hdr & NDEF_CF_MASK) {
142 if (!b_allow_chunks) return (NDEF_MSG_UNEXPECTED_CHUNK);
143
144 /* Inside a chunk, the type must be unchanged and no type or ID field i
145 * sallowed */
146 if (bInChunk) {
147 if ((type_len != 0) || (id_len != 0) ||
148 ((rec_hdr & NDEF_TNF_MASK) != NDEF_TNF_UNCHANGED))
149 return (NDEF_MSG_INVALID_CHUNK);
150 } else {
151 /* First record of a chunk must NOT have type "unchanged" */
152 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_UNCHANGED)
153 return (NDEF_MSG_INVALID_CHUNK);
154
155 bInChunk = true;
156 }
157 } else {
158 /* This may be the last guy in a chunk. */
159 if (bInChunk) {
160 if ((type_len != 0) || (id_len != 0) ||
161 ((rec_hdr & NDEF_TNF_MASK) != NDEF_TNF_UNCHANGED))
162 return (NDEF_MSG_INVALID_CHUNK);
163
164 bInChunk = false;
165 } else {
166 /* If not in a chunk, the record must NOT have type "unchanged" */
167 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_UNCHANGED)
168 return (NDEF_MSG_INVALID_CHUNK);
169 }
170 }
171
172 /* An empty record must NOT have a type, ID or payload */
173 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_EMPTY) {
174 if ((type_len != 0) || (id_len != 0) || (payload_len != 0))
175 return (NDEF_MSG_INVALID_EMPTY_REC);
176 }
177
178 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_UNKNOWN) {
179 if (type_len != 0) return (NDEF_MSG_LENGTH_MISMATCH);
180 }
181
182 /* External type should have non-zero type length */
183 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_EXT) {
184 if (type_len == 0) return (NDEF_MSG_LENGTH_MISMATCH);
185 }
186
187 /* External type and Well Known types should have valid characters
188 in the TYPE field */
189 if ((rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_EXT ||
190 (rec_hdr & NDEF_TNF_MASK) == NDEF_TNF_WKT) {
191 uint8_t* p_rec_type = p_rec;
192 if ((p_rec_type + type_len) > p_end) return (NDEF_MSG_TOO_SHORT);
193
194 for (int type_index = 0; type_index < type_len; type_index++) {
195 if (p_rec_type[type_index] < NDEF_RTD_VALID_START ||
196 p_rec_type[type_index] > NDEF_RTD_VALID_END)
197 return (NDEF_MSG_INVALID_TYPE);
198 }
199 }
200
201 /* Check for OOB */
202 if (payload_len + type_len + id_len < payload_len ||
203 payload_len + type_len + id_len > msg_len) {
204 return (NDEF_MSG_LENGTH_MISMATCH);
205 }
206 p_new = p_rec + (payload_len + type_len + id_len);
207 if (p_rec > p_new || p_end < p_new) {
208 android_errorWriteLog(0x534e4554, "126200054");
209 return (NDEF_MSG_LENGTH_MISMATCH);
210 }
211
212 /* Point to next record */
213 p_rec += (payload_len + type_len + id_len);
214
215 if (rec_hdr & NDEF_ME_MASK) break;
216
217 rec_hdr = 0;
218 }
219
220 /* The last record should have the ME bit set */
221 if ((rec_hdr & NDEF_ME_MASK) == 0) return (NDEF_MSG_NO_MSG_END);
222
223 /* p_rec should equal p_end if all the length fields were correct */
224 if (p_rec != p_end) return (NDEF_MSG_LENGTH_MISMATCH);
225
226 return (NDEF_OK);
227 }
228
229 /*******************************************************************************
230 **
231 ** Function NDEF_MsgGetNumRecs
232 **
233 ** Description This function gets the number of records in the given NDEF
234 ** message.
235 **
236 ** Returns The record count, or 0 if the message is invalid.
237 **
238 *******************************************************************************/
NDEF_MsgGetNumRecs(uint8_t * p_msg)239 int32_t NDEF_MsgGetNumRecs(uint8_t* p_msg) {
240 uint8_t* p_rec = p_msg;
241 uint8_t rec_hdr, type_len, id_len;
242 int count;
243 uint32_t payload_len;
244
245 for (count = 0;;) {
246 count++;
247
248 rec_hdr = *p_rec++;
249
250 if (rec_hdr & NDEF_ME_MASK) break;
251
252 /* Type field length */
253 type_len = *p_rec++;
254
255 /* Payload length - can be 1 or 4 bytes */
256 if (rec_hdr & NDEF_SR_MASK)
257 payload_len = *p_rec++;
258 else
259 BE_STREAM_TO_UINT32(payload_len, p_rec);
260
261 /* ID field Length */
262 if (rec_hdr & NDEF_IL_MASK)
263 id_len = *p_rec++;
264 else
265 id_len = 0;
266
267 /* Point to next record */
268 p_rec += (payload_len + type_len + id_len);
269 }
270
271 /* Return the number of records found */
272 return (count);
273 }
274
275 /*******************************************************************************
276 **
277 ** Function NDEF_MsgGetRecLength
278 **
279 ** Description This function returns length of the current record in the
280 ** given NDEF message.
281 **
282 ** Returns Length of record
283 **
284 *******************************************************************************/
NDEF_MsgGetRecLength(uint8_t * p_cur_rec)285 uint32_t NDEF_MsgGetRecLength(uint8_t* p_cur_rec) {
286 uint8_t rec_hdr, type_len, id_len;
287 uint32_t rec_len = 0;
288 uint32_t payload_len;
289
290 /* Get the current record's header */
291 rec_hdr = *p_cur_rec++;
292 rec_len++;
293
294 /* Type field length */
295 type_len = *p_cur_rec++;
296 rec_len++;
297
298 /* Payload length - can be 1 or 4 bytes */
299 if (rec_hdr & NDEF_SR_MASK) {
300 payload_len = *p_cur_rec++;
301 rec_len++;
302 } else {
303 BE_STREAM_TO_UINT32(payload_len, p_cur_rec);
304 rec_len += 4;
305 }
306
307 /* ID field Length */
308 if (rec_hdr & NDEF_IL_MASK) {
309 id_len = *p_cur_rec++;
310 rec_len++;
311 } else
312 id_len = 0;
313
314 /* Total length of record */
315 rec_len += (payload_len + type_len + id_len);
316
317 return (rec_len);
318 }
319
320 /*******************************************************************************
321 **
322 ** Function NDEF_MsgGetNextRec
323 **
324 ** Description This function gets a pointer to the next record in the given
325 ** NDEF message. If the current record pointer is NULL, a
326 ** pointer to the first record is returned.
327 **
328 ** Returns Pointer to the start of the record, or NULL if no more
329 **
330 *******************************************************************************/
NDEF_MsgGetNextRec(uint8_t * p_cur_rec)331 uint8_t* NDEF_MsgGetNextRec(uint8_t* p_cur_rec) {
332 uint8_t rec_hdr, type_len, id_len;
333 uint32_t payload_len;
334
335 /* Get the current record's header */
336 rec_hdr = *p_cur_rec++;
337
338 /* If this is the last record, return NULL */
339 if (rec_hdr & NDEF_ME_MASK) return (nullptr);
340
341 /* Type field length */
342 type_len = *p_cur_rec++;
343
344 /* Payload length - can be 1 or 4 bytes */
345 if (rec_hdr & NDEF_SR_MASK)
346 payload_len = *p_cur_rec++;
347 else
348 BE_STREAM_TO_UINT32(payload_len, p_cur_rec);
349
350 /* ID field Length */
351 if (rec_hdr & NDEF_IL_MASK)
352 id_len = *p_cur_rec++;
353 else
354 id_len = 0;
355
356 /* Point to next record */
357 p_cur_rec += (payload_len + type_len + id_len);
358
359 return (p_cur_rec);
360 }
361
362 /*******************************************************************************
363 **
364 ** Function NDEF_MsgGetRecByIndex
365 **
366 ** Description This function gets a pointer to the record with the given
367 ** index (0-based index) in the given NDEF message.
368 **
369 ** Returns Pointer to the start of the record, or NULL
370 **
371 *******************************************************************************/
NDEF_MsgGetRecByIndex(uint8_t * p_msg,int32_t index)372 uint8_t* NDEF_MsgGetRecByIndex(uint8_t* p_msg, int32_t index) {
373 uint8_t* p_rec = p_msg;
374 uint8_t rec_hdr, type_len, id_len;
375 int32_t count;
376 uint32_t payload_len;
377
378 for (count = 0;; count++) {
379 if (count == index) return (p_rec);
380
381 rec_hdr = *p_rec++;
382
383 if (rec_hdr & NDEF_ME_MASK) return (nullptr);
384
385 /* Type field length */
386 type_len = *p_rec++;
387
388 /* Payload length - can be 1 or 4 bytes */
389 if (rec_hdr & NDEF_SR_MASK)
390 payload_len = *p_rec++;
391 else
392 BE_STREAM_TO_UINT32(payload_len, p_rec);
393
394 /* ID field Length */
395 if (rec_hdr & NDEF_IL_MASK)
396 id_len = *p_rec++;
397 else
398 id_len = 0;
399
400 /* Point to next record */
401 p_rec += (payload_len + type_len + id_len);
402 }
403
404 /* If here, there is no record of that index */
405 return (nullptr);
406 }
407
408 /*******************************************************************************
409 **
410 ** Function NDEF_MsgGetLastRecInMsg
411 **
412 ** Description This function gets a pointer to the last record in the
413 ** given NDEF message.
414 **
415 ** Returns Pointer to the start of the last record, or NULL if some
416 ** problem
417 **
418 *******************************************************************************/
NDEF_MsgGetLastRecInMsg(uint8_t * p_msg)419 uint8_t* NDEF_MsgGetLastRecInMsg(uint8_t* p_msg) {
420 uint8_t* p_rec = p_msg;
421 uint8_t* pRecStart;
422 uint8_t rec_hdr, type_len, id_len;
423 uint32_t payload_len;
424
425 for (;;) {
426 pRecStart = p_rec;
427 rec_hdr = *p_rec++;
428
429 if (rec_hdr & NDEF_ME_MASK) break;
430
431 /* Type field length */
432 type_len = *p_rec++;
433
434 /* Payload length - can be 1 or 4 bytes */
435 if (rec_hdr & NDEF_SR_MASK)
436 payload_len = *p_rec++;
437 else
438 BE_STREAM_TO_UINT32(payload_len, p_rec);
439
440 /* ID field Length */
441 if (rec_hdr & NDEF_IL_MASK)
442 id_len = *p_rec++;
443 else
444 id_len = 0;
445
446 /* Point to next record */
447 p_rec += (payload_len + type_len + id_len);
448 }
449
450 return (pRecStart);
451 }
452
453 /*******************************************************************************
454 **
455 ** Function NDEF_MsgGetFirstRecByType
456 **
457 ** Description This function gets a pointer to the first record with the
458 ** given record type in the given NDEF message.
459 **
460 ** Returns Pointer to the start of the record, or NULL
461 **
462 *******************************************************************************/
NDEF_MsgGetFirstRecByType(uint8_t * p_msg,uint8_t tnf,uint8_t * p_type,uint8_t tlen)463 uint8_t* NDEF_MsgGetFirstRecByType(uint8_t* p_msg, uint8_t tnf, uint8_t* p_type,
464 uint8_t tlen) {
465 uint8_t* p_rec = p_msg;
466 uint8_t* pRecStart;
467 uint8_t rec_hdr, type_len, id_len;
468 uint32_t payload_len;
469
470 for (;;) {
471 pRecStart = p_rec;
472
473 rec_hdr = *p_rec++;
474
475 /* Type field length */
476 type_len = *p_rec++;
477
478 /* Payload length - can be 1 or 4 bytes */
479 if (rec_hdr & NDEF_SR_MASK)
480 payload_len = *p_rec++;
481 else
482 BE_STREAM_TO_UINT32(payload_len, p_rec);
483
484 /* ID field Length */
485 if (rec_hdr & NDEF_IL_MASK)
486 id_len = *p_rec++;
487 else
488 id_len = 0;
489
490 /* At this point, p_rec points to the start of the type field. We need to */
491 /* compare the type of the type, the length of the type and the data */
492 if (((rec_hdr & NDEF_TNF_MASK) == tnf) && (type_len == tlen) &&
493 (!memcmp(p_rec, p_type, tlen)))
494 return (pRecStart);
495
496 /* If this was the last record, return NULL */
497 if (rec_hdr & NDEF_ME_MASK) return (nullptr);
498
499 /* Point to next record */
500 p_rec += (payload_len + type_len + id_len);
501 }
502
503 /* If here, there is no record of that type */
504 return (nullptr);
505 }
506
507 /*******************************************************************************
508 **
509 ** Function NDEF_MsgGetNextRecByType
510 **
511 ** Description This function gets a pointer to the next record with the
512 ** given record type in the given NDEF message.
513 **
514 ** Returns Pointer to the start of the record, or NULL
515 **
516 *******************************************************************************/
NDEF_MsgGetNextRecByType(uint8_t * p_cur_rec,uint8_t tnf,uint8_t * p_type,uint8_t tlen)517 uint8_t* NDEF_MsgGetNextRecByType(uint8_t* p_cur_rec, uint8_t tnf,
518 uint8_t* p_type, uint8_t tlen) {
519 uint8_t* p_rec;
520 uint8_t* pRecStart;
521 uint8_t rec_hdr, type_len, id_len;
522 uint32_t payload_len;
523
524 /* If this is the last record in the message, return NULL */
525 p_rec = NDEF_MsgGetNextRec(p_cur_rec);
526 if (p_rec == nullptr) return (nullptr);
527
528 for (;;) {
529 pRecStart = p_rec;
530
531 rec_hdr = *p_rec++;
532
533 /* Type field length */
534 type_len = *p_rec++;
535
536 /* Payload length - can be 1 or 4 bytes */
537 if (rec_hdr & NDEF_SR_MASK)
538 payload_len = *p_rec++;
539 else
540 BE_STREAM_TO_UINT32(payload_len, p_rec);
541
542 /* ID field Length */
543 if (rec_hdr & NDEF_IL_MASK)
544 id_len = *p_rec++;
545 else
546 id_len = 0;
547
548 /* At this point, p_rec points to the start of the type field. We need to */
549 /* compare the type of the type, the length of the type and the data */
550 if (((rec_hdr & NDEF_TNF_MASK) == tnf) && (type_len == tlen) &&
551 (!memcmp(p_rec, p_type, tlen)))
552 return (pRecStart);
553
554 /* If this was the last record, return NULL */
555 if (rec_hdr & NDEF_ME_MASK) break;
556
557 /* Point to next record */
558 p_rec += (payload_len + type_len + id_len);
559 }
560
561 /* If here, there is no record of that type */
562 return (nullptr);
563 }
564
565 /*******************************************************************************
566 **
567 ** Function NDEF_MsgGetFirstRecById
568 **
569 ** Description This function gets a pointer to the first record with the
570 ** given record id in the given NDEF message.
571 **
572 ** Returns Pointer to the start of the record, or NULL
573 **
574 *******************************************************************************/
NDEF_MsgGetFirstRecById(uint8_t * p_msg,uint8_t * p_id,uint8_t ilen)575 uint8_t* NDEF_MsgGetFirstRecById(uint8_t* p_msg, uint8_t* p_id, uint8_t ilen) {
576 uint8_t* p_rec = p_msg;
577 uint8_t* pRecStart;
578 uint8_t rec_hdr, type_len, id_len;
579 uint32_t payload_len;
580
581 for (;;) {
582 pRecStart = p_rec;
583
584 rec_hdr = *p_rec++;
585
586 /* Type field length */
587 type_len = *p_rec++;
588
589 /* Payload length - can be 1 or 4 bytes */
590 if (rec_hdr & NDEF_SR_MASK)
591 payload_len = *p_rec++;
592 else
593 BE_STREAM_TO_UINT32(payload_len, p_rec);
594
595 /* ID field Length */
596 if (rec_hdr & NDEF_IL_MASK)
597 id_len = *p_rec++;
598 else
599 id_len = 0;
600
601 /* At this point, p_rec points to the start of the type field. Skip it */
602 p_rec += type_len;
603
604 /* At this point, p_rec points to the start of the ID field. Compare length
605 * and data */
606 if ((id_len == ilen) && (!memcmp(p_rec, p_id, ilen))) return (pRecStart);
607
608 /* If this was the last record, return NULL */
609 if (rec_hdr & NDEF_ME_MASK) return (nullptr);
610
611 /* Point to next record */
612 p_rec += (id_len + payload_len);
613 }
614
615 /* If here, there is no record of that ID */
616 return (nullptr);
617 }
618
619 /*******************************************************************************
620 **
621 ** Function NDEF_MsgGetNextRecById
622 **
623 ** Description This function gets a pointer to the next record with the
624 ** given record id in the given NDEF message.
625 **
626 ** Returns Pointer to the start of the record, or NULL
627 **
628 *******************************************************************************/
NDEF_MsgGetNextRecById(uint8_t * p_cur_rec,uint8_t * p_id,uint8_t ilen)629 uint8_t* NDEF_MsgGetNextRecById(uint8_t* p_cur_rec, uint8_t* p_id,
630 uint8_t ilen) {
631 uint8_t* p_rec;
632 uint8_t* pRecStart;
633 uint8_t rec_hdr, type_len, id_len;
634 uint32_t payload_len;
635
636 /* If this is the last record in the message, return NULL */
637 p_rec = NDEF_MsgGetNextRec(p_cur_rec);
638 if (p_rec == nullptr) return (nullptr);
639
640 for (;;) {
641 pRecStart = p_rec;
642
643 rec_hdr = *p_rec++;
644
645 /* Type field length */
646 type_len = *p_rec++;
647
648 /* Payload length - can be 1 or 4 bytes */
649 if (rec_hdr & NDEF_SR_MASK)
650 payload_len = *p_rec++;
651 else
652 BE_STREAM_TO_UINT32(payload_len, p_rec);
653
654 /* ID field Length */
655 if (rec_hdr & NDEF_IL_MASK)
656 id_len = *p_rec++;
657 else
658 id_len = 0;
659
660 /* At this point, p_rec points to the start of the type field. Skip it */
661 p_rec += type_len;
662
663 /* At this point, p_rec points to the start of the ID field. Compare length
664 * and data */
665 if ((id_len == ilen) && (!memcmp(p_rec, p_id, ilen))) return (pRecStart);
666
667 /* If this was the last record, return NULL */
668 if (rec_hdr & NDEF_ME_MASK) break;
669
670 /* Point to next record */
671 p_rec += (id_len + payload_len);
672 }
673
674 /* If here, there is no record of that ID */
675 return (nullptr);
676 }
677
678 /*******************************************************************************
679 **
680 ** Function NDEF_RecGetType
681 **
682 ** Description This function gets a pointer to the record type for the
683 ** given NDEF record.
684 **
685 ** Returns Pointer to Type (NULL if none). TNF and len are filled in.
686 **
687 *******************************************************************************/
NDEF_RecGetType(uint8_t * p_rec,uint8_t * p_tnf,uint8_t * p_type_len)688 uint8_t* NDEF_RecGetType(uint8_t* p_rec, uint8_t* p_tnf, uint8_t* p_type_len) {
689 uint8_t rec_hdr, type_len;
690
691 /* First byte is the record header */
692 rec_hdr = *p_rec++;
693
694 /* Next byte is the type field length */
695 type_len = *p_rec++;
696
697 /* Skip the payload length */
698 if (rec_hdr & NDEF_SR_MASK)
699 p_rec += 1;
700 else
701 p_rec += 4;
702
703 /* Skip ID field Length, if present */
704 if (rec_hdr & NDEF_IL_MASK) p_rec++;
705
706 /* At this point, p_rec points to the start of the type field. */
707 *p_type_len = type_len;
708 *p_tnf = rec_hdr & NDEF_TNF_MASK;
709
710 if (type_len == 0)
711 return (nullptr);
712 else
713 return (p_rec);
714 }
715
716 /*******************************************************************************
717 **
718 ** Function NDEF_RecGetId
719 **
720 ** Description This function gets a pointer to the record id for the given
721 ** NDEF record.
722 **
723 ** Returns Pointer to Id (NULL if none). ID Len is filled in.
724 **
725 *******************************************************************************/
NDEF_RecGetId(uint8_t * p_rec,uint8_t * p_id_len)726 uint8_t* NDEF_RecGetId(uint8_t* p_rec, uint8_t* p_id_len) {
727 uint8_t rec_hdr, type_len;
728
729 /* First byte is the record header */
730 rec_hdr = *p_rec++;
731
732 /* Next byte is the type field length */
733 type_len = *p_rec++;
734
735 /* Skip the payload length */
736 if (rec_hdr & NDEF_SR_MASK)
737 p_rec++;
738 else
739 p_rec += 4;
740
741 /* ID field Length */
742 if (rec_hdr & NDEF_IL_MASK)
743 *p_id_len = *p_rec++;
744 else
745 *p_id_len = 0;
746
747 /* p_rec now points to the start of the type field. The ID field follows it */
748 if (*p_id_len == 0)
749 return (nullptr);
750 else
751 return (p_rec + type_len);
752 }
753
754 /*******************************************************************************
755 **
756 ** Function NDEF_RecGetPayload
757 **
758 ** Description This function gets a pointer to the payload for the given
759 ** NDEF record.
760 **
761 ** Returns a pointer to the payload (or NULL none). Payload len filled
762 ** in.
763 **
764 *******************************************************************************/
NDEF_RecGetPayload(uint8_t * p_rec,uint32_t * p_payload_len)765 uint8_t* NDEF_RecGetPayload(uint8_t* p_rec, uint32_t* p_payload_len) {
766 uint8_t rec_hdr, type_len, id_len;
767 uint32_t payload_len;
768
769 /* First byte is the record header */
770 rec_hdr = *p_rec++;
771
772 /* Next byte is the type field length */
773 type_len = *p_rec++;
774
775 /* Next is the payload length (1 or 4 bytes) */
776 if (rec_hdr & NDEF_SR_MASK)
777 payload_len = *p_rec++;
778 else
779 BE_STREAM_TO_UINT32(payload_len, p_rec);
780
781 *p_payload_len = payload_len;
782
783 /* ID field Length */
784 if (rec_hdr & NDEF_IL_MASK)
785 id_len = *p_rec++;
786 else
787 id_len = 0;
788
789 /* p_rec now points to the start of the type field. The ID field follows it,
790 * then the payload */
791 if (payload_len == 0)
792 return (nullptr);
793 else
794 return (p_rec + type_len + id_len);
795 }
796
797 /*******************************************************************************
798 **
799 ** Function NDEF_MsgInit
800 **
801 ** Description This function initializes an NDEF message.
802 **
803 ** Returns void
804 ** *p_cur_size is initialized to 0
805 **
806 *******************************************************************************/
NDEF_MsgInit(uint8_t * p_msg,uint32_t max_size,uint32_t * p_cur_size)807 void NDEF_MsgInit(uint8_t* p_msg, uint32_t max_size, uint32_t* p_cur_size) {
808 *p_cur_size = 0;
809 memset(p_msg, 0, max_size);
810 }
811
812 /*******************************************************************************
813 **
814 ** Function NDEF_MsgAddRec
815 **
816 ** Description This function adds an NDEF record to the end of an NDEF
817 ** message.
818 **
819 ** Returns OK, or error if the record did not fit
820 ** *p_cur_size is updated
821 **
822 *******************************************************************************/
NDEF_MsgAddRec(uint8_t * p_msg,uint32_t max_size,uint32_t * p_cur_size,uint8_t tnf,uint8_t * p_type,uint8_t type_len,uint8_t * p_id,uint8_t id_len,uint8_t * p_payload,uint32_t payload_len)823 extern tNDEF_STATUS NDEF_MsgAddRec(uint8_t* p_msg, uint32_t max_size,
824 uint32_t* p_cur_size, uint8_t tnf,
825 uint8_t* p_type, uint8_t type_len,
826 uint8_t* p_id, uint8_t id_len,
827 uint8_t* p_payload, uint32_t payload_len) {
828 uint8_t* p_rec = p_msg + *p_cur_size;
829 uint32_t recSize;
830 int plen = (payload_len < 256) ? 1 : 4;
831 int ilen = (id_len == 0) ? 0 : 1;
832
833 if (tnf > NDEF_TNF_RESERVED) {
834 tnf = NDEF_TNF_UNKNOWN;
835 type_len = 0;
836 }
837
838 /* First, make sure the record will fit. we need at least 2 bytes for header
839 * and type length */
840 recSize = payload_len + 2 + type_len + plen + ilen + id_len;
841
842 if ((*p_cur_size + recSize) > max_size) return (NDEF_MSG_INSUFFICIENT_MEM);
843
844 /* Construct the record header. For the first record, set both begin and end
845 * bits */
846 if (*p_cur_size == 0)
847 *p_rec = tnf | NDEF_MB_MASK | NDEF_ME_MASK;
848 else {
849 /* Find the previous last and clear his 'Message End' bit */
850 uint8_t* pLast = NDEF_MsgGetLastRecInMsg(p_msg);
851
852 if (!pLast) return (NDEF_MSG_NO_MSG_END);
853
854 *pLast &= ~NDEF_ME_MASK;
855 *p_rec = tnf | NDEF_ME_MASK;
856 }
857
858 if (plen == 1) *p_rec |= NDEF_SR_MASK;
859
860 if (ilen != 0) *p_rec |= NDEF_IL_MASK;
861
862 p_rec++;
863
864 /* The next byte is the type field length */
865 *p_rec++ = type_len;
866
867 /* Payload length - can be 1 or 4 bytes */
868 if (plen == 1)
869 *p_rec++ = (uint8_t)payload_len;
870 else
871 UINT32_TO_BE_STREAM(p_rec, payload_len);
872
873 /* ID field Length (optional) */
874 if (ilen > 0) *p_rec++ = id_len;
875
876 /* Next comes the type */
877 if (type_len) {
878 if (p_type) memcpy(p_rec, p_type, type_len);
879
880 p_rec += type_len;
881 }
882
883 /* Next comes the ID */
884 if (id_len) {
885 if (p_id) memcpy(p_rec, p_id, id_len);
886
887 p_rec += id_len;
888 }
889
890 /* And lastly the payload. If NULL, the app just wants to reserve memory */
891 if (p_payload) memcpy(p_rec, p_payload, payload_len);
892
893 *p_cur_size += recSize;
894
895 return (NDEF_OK);
896 }
897
898 /*******************************************************************************
899 **
900 ** Function NDEF_MsgAppendPayload
901 **
902 ** Description This function appends extra payload to a specific record in
903 ** the given NDEF message
904 **
905 ** Returns OK, or error if the extra payload did not fit
906 ** *p_cur_size is updated
907 **
908 *******************************************************************************/
NDEF_MsgAppendPayload(uint8_t * p_msg,uint32_t max_size,uint32_t * p_cur_size,uint8_t * p_rec,uint8_t * p_add_pl,uint32_t add_pl_len)909 tNDEF_STATUS NDEF_MsgAppendPayload(uint8_t* p_msg, uint32_t max_size,
910 uint32_t* p_cur_size, uint8_t* p_rec,
911 uint8_t* p_add_pl, uint32_t add_pl_len) {
912 uint32_t prev_paylen, new_paylen;
913 uint8_t *p_prev_pl, *pp;
914 uint8_t incr_lenfld = 0;
915 uint8_t type_len, id_len;
916
917 /* Skip header */
918 pp = p_rec + 1;
919
920 /* Next byte is the type field length */
921 type_len = *pp++;
922
923 /* Next is the payload length (1 or 4 bytes) */
924 if (*p_rec & NDEF_SR_MASK)
925 prev_paylen = *pp++;
926 else
927 BE_STREAM_TO_UINT32(prev_paylen, pp);
928
929 /* ID field Length */
930 if (*p_rec & NDEF_IL_MASK)
931 id_len = *pp++;
932 else
933 id_len = 0;
934
935 p_prev_pl = pp + type_len + id_len;
936
937 new_paylen = prev_paylen + add_pl_len;
938
939 /* Previous payload may be < 256, and this addition may make it larger than
940 * 256 */
941 /* If that were to happen, the payload length field goes from 1 byte to 4
942 * bytes */
943 if ((prev_paylen < 256) && (new_paylen > 255)) incr_lenfld = 3;
944
945 /* Check that it all fits */
946 if ((*p_cur_size + add_pl_len + incr_lenfld) > max_size)
947 return (NDEF_MSG_INSUFFICIENT_MEM);
948
949 /* Point to payload length field */
950 pp = p_rec + 2;
951
952 /* If we need to increase the length field from 1 to 4 bytes, do it first */
953 if (incr_lenfld) {
954 shiftdown(pp + 1, (uint32_t)(*p_cur_size - (pp - p_msg) - 1), 3);
955 p_prev_pl += 3;
956 }
957
958 /* Store in the new length */
959 if (new_paylen > 255) {
960 *p_rec &= ~NDEF_SR_MASK;
961 UINT32_TO_BE_STREAM(pp, new_paylen);
962 } else
963 *pp = (uint8_t)new_paylen;
964
965 /* Point to the end of the previous payload */
966 pp = p_prev_pl + prev_paylen;
967
968 /* If we are not the last record, make space for the extra payload */
969 if ((*p_rec & NDEF_ME_MASK) == 0)
970 shiftdown(pp, (uint32_t)(*p_cur_size - (pp - p_msg)), add_pl_len);
971
972 /* Now copy in the additional payload data */
973 memcpy(pp, p_add_pl, add_pl_len);
974
975 *p_cur_size += add_pl_len + incr_lenfld;
976
977 return (NDEF_OK);
978 }
979
980 /*******************************************************************************
981 **
982 ** Function NDEF_MsgReplacePayload
983 **
984 ** Description This function replaces the payload of a specific record in
985 ** the given NDEF message
986 **
987 ** Returns OK, or error if the new payload did not fit
988 ** *p_cur_size is updated
989 **
990 *******************************************************************************/
NDEF_MsgReplacePayload(uint8_t * p_msg,uint32_t max_size,uint32_t * p_cur_size,uint8_t * p_rec,uint8_t * p_new_pl,uint32_t new_pl_len)991 tNDEF_STATUS NDEF_MsgReplacePayload(uint8_t* p_msg, uint32_t max_size,
992 uint32_t* p_cur_size, uint8_t* p_rec,
993 uint8_t* p_new_pl, uint32_t new_pl_len) {
994 uint32_t prev_paylen;
995 uint8_t *p_prev_pl, *pp;
996 uint32_t paylen_delta;
997 uint8_t type_len, id_len;
998
999 /* Skip header */
1000 pp = p_rec + 1;
1001
1002 /* Next byte is the type field length */
1003 type_len = *pp++;
1004
1005 /* Next is the payload length (1 or 4 bytes) */
1006 if (*p_rec & NDEF_SR_MASK)
1007 prev_paylen = *pp++;
1008 else
1009 BE_STREAM_TO_UINT32(prev_paylen, pp);
1010
1011 /* ID field Length */
1012 if (*p_rec & NDEF_IL_MASK)
1013 id_len = *pp++;
1014 else
1015 id_len = 0;
1016
1017 p_prev_pl = pp + type_len + id_len;
1018
1019 /* Point to payload length field again */
1020 pp = p_rec + 2;
1021
1022 if (new_pl_len > prev_paylen) {
1023 /* New payload is larger than the previous */
1024 paylen_delta = new_pl_len - prev_paylen;
1025
1026 /* If the previous payload length was < 256, and new is > 255 */
1027 /* the payload length field goes from 1 byte to 4 bytes */
1028 if ((prev_paylen < 256) && (new_pl_len > 255)) {
1029 if ((*p_cur_size + paylen_delta + 3) > max_size)
1030 return (NDEF_MSG_INSUFFICIENT_MEM);
1031
1032 shiftdown(pp + 1, (uint32_t)(*p_cur_size - (pp - p_msg) - 1), 3);
1033 p_prev_pl += 3;
1034 *p_cur_size += 3;
1035 *p_rec &= ~NDEF_SR_MASK;
1036 } else if ((*p_cur_size + paylen_delta) > max_size)
1037 return (NDEF_MSG_INSUFFICIENT_MEM);
1038
1039 /* Store in the new length */
1040 if (new_pl_len > 255) {
1041 UINT32_TO_BE_STREAM(pp, new_pl_len);
1042 } else
1043 *pp = (uint8_t)new_pl_len;
1044
1045 /* Point to the end of the previous payload */
1046 pp = p_prev_pl + prev_paylen;
1047
1048 /* If we are not the last record, make space for the extra payload */
1049 if ((*p_rec & NDEF_ME_MASK) == 0)
1050 shiftdown(pp, (uint32_t)(*p_cur_size - (pp - p_msg)), paylen_delta);
1051
1052 *p_cur_size += paylen_delta;
1053 } else if (new_pl_len < prev_paylen) {
1054 /* New payload is smaller than the previous */
1055 paylen_delta = prev_paylen - new_pl_len;
1056
1057 /* If the previous payload was > 256, and new is less than 256 */
1058 /* the payload length field goes from 4 bytes to 1 byte */
1059 if ((prev_paylen > 255) && (new_pl_len < 256)) {
1060 shiftup(pp + 1, pp + 4, (uint32_t)(*p_cur_size - (pp - p_msg) - 3));
1061 p_prev_pl -= 3;
1062 *p_cur_size -= 3;
1063 *p_rec |= NDEF_SR_MASK;
1064 }
1065
1066 /* Store in the new length */
1067 if (new_pl_len > 255) {
1068 UINT32_TO_BE_STREAM(pp, new_pl_len);
1069 } else
1070 *pp = (uint8_t)new_pl_len;
1071
1072 /* Point to the end of the previous payload */
1073 pp = p_prev_pl + prev_paylen;
1074
1075 /* If we are not the last record, remove the extra space from the previous
1076 * payload */
1077 if ((*p_rec & NDEF_ME_MASK) == 0)
1078 shiftup(pp - paylen_delta, pp, (uint32_t)(*p_cur_size - (pp - p_msg)));
1079
1080 *p_cur_size -= paylen_delta;
1081 }
1082
1083 /* Now copy in the new payload data */
1084 if (p_new_pl) memcpy(p_prev_pl, p_new_pl, new_pl_len);
1085
1086 return (NDEF_OK);
1087 }
1088
1089 /*******************************************************************************
1090 **
1091 ** Function NDEF_MsgReplaceType
1092 **
1093 ** Description This function replaces the type field of a specific record
1094 ** in the given NDEF message
1095 **
1096 ** Returns OK, or error if the new type field did not fit
1097 ** *p_cur_size is updated
1098 **
1099 *******************************************************************************/
NDEF_MsgReplaceType(uint8_t * p_msg,uint32_t max_size,uint32_t * p_cur_size,uint8_t * p_rec,uint8_t * p_new_type,uint8_t new_type_len)1100 tNDEF_STATUS NDEF_MsgReplaceType(uint8_t* p_msg, uint32_t max_size,
1101 uint32_t* p_cur_size, uint8_t* p_rec,
1102 uint8_t* p_new_type, uint8_t new_type_len) {
1103 uint8_t typelen_delta;
1104 uint8_t *p_prev_type, prev_type_len;
1105 uint8_t* pp;
1106
1107 /* Skip header */
1108 pp = p_rec + 1;
1109
1110 /* Next byte is the type field length */
1111 prev_type_len = *pp++;
1112
1113 /* Skip the payload length */
1114 if (*p_rec & NDEF_SR_MASK)
1115 pp += 1;
1116 else
1117 pp += 4;
1118
1119 if (*p_rec & NDEF_IL_MASK) pp++;
1120
1121 /* Save pointer to the start of the type field */
1122 p_prev_type = pp;
1123
1124 if (new_type_len > prev_type_len) {
1125 /* New type is larger than the previous */
1126 typelen_delta = new_type_len - prev_type_len;
1127
1128 if ((*p_cur_size + typelen_delta) > max_size)
1129 return (NDEF_MSG_INSUFFICIENT_MEM);
1130
1131 /* Point to the end of the previous type, and make space for the extra data
1132 */
1133 pp = p_prev_type + prev_type_len;
1134 shiftdown(pp, (uint32_t)(*p_cur_size - (pp - p_msg)), typelen_delta);
1135
1136 *p_cur_size += typelen_delta;
1137 } else if (new_type_len < prev_type_len) {
1138 /* New type field is smaller than the previous */
1139 typelen_delta = prev_type_len - new_type_len;
1140
1141 /* Point to the end of the previous type, and shift up to fill the the
1142 * unused space */
1143 pp = p_prev_type + prev_type_len;
1144 shiftup(pp - typelen_delta, pp, (uint32_t)(*p_cur_size - (pp - p_msg)));
1145
1146 *p_cur_size -= typelen_delta;
1147 }
1148
1149 /* Save in new type length */
1150 p_rec[1] = new_type_len;
1151
1152 /* Now copy in the new type field data */
1153 if (p_new_type) memcpy(p_prev_type, p_new_type, new_type_len);
1154
1155 return (NDEF_OK);
1156 }
1157
1158 /*******************************************************************************
1159 **
1160 ** Function NDEF_MsgReplaceId
1161 **
1162 ** Description This function replaces the ID field of a specific record in
1163 ** the given NDEF message
1164 **
1165 ** Returns OK, or error if the new ID field did not fit
1166 ** *p_cur_size is updated
1167 **
1168 *******************************************************************************/
NDEF_MsgReplaceId(uint8_t * p_msg,uint32_t max_size,uint32_t * p_cur_size,uint8_t * p_rec,uint8_t * p_new_id,uint8_t new_id_len)1169 tNDEF_STATUS NDEF_MsgReplaceId(uint8_t* p_msg, uint32_t max_size,
1170 uint32_t* p_cur_size, uint8_t* p_rec,
1171 uint8_t* p_new_id, uint8_t new_id_len) {
1172 uint8_t idlen_delta;
1173 uint8_t *p_prev_id, *p_idlen_field;
1174 uint8_t prev_id_len, type_len;
1175 uint8_t* pp;
1176
1177 /* Skip header */
1178 pp = p_rec + 1;
1179
1180 /* Next byte is the type field length */
1181 type_len = *pp++;
1182
1183 /* Skip the payload length */
1184 if (*p_rec & NDEF_SR_MASK)
1185 pp += 1;
1186 else
1187 pp += 4;
1188
1189 p_idlen_field = pp;
1190
1191 if (*p_rec & NDEF_IL_MASK)
1192 prev_id_len = *pp++;
1193 else
1194 prev_id_len = 0;
1195
1196 /* Save pointer to the start of the ID field (right after the type field) */
1197 p_prev_id = pp + type_len;
1198
1199 if (new_id_len > prev_id_len) {
1200 /* New ID field is larger than the previous */
1201 idlen_delta = new_id_len - prev_id_len;
1202
1203 /* If the previous ID length was 0, we need to add a 1-byte ID length */
1204 if (prev_id_len == 0) {
1205 if ((*p_cur_size + idlen_delta + 1) > max_size)
1206 return (NDEF_MSG_INSUFFICIENT_MEM);
1207
1208 shiftdown(p_idlen_field,
1209 (uint32_t)(*p_cur_size - (p_idlen_field - p_msg)), 1);
1210 p_prev_id += 1;
1211 *p_cur_size += 1;
1212 *p_rec |= NDEF_IL_MASK;
1213 } else if ((*p_cur_size + idlen_delta) > max_size)
1214 return (NDEF_MSG_INSUFFICIENT_MEM);
1215
1216 /* Point to the end of the previous ID field, and make space for the extra
1217 * data */
1218 pp = p_prev_id + prev_id_len;
1219 shiftdown(pp, (uint32_t)(*p_cur_size - (pp - p_msg)), idlen_delta);
1220
1221 *p_cur_size += idlen_delta;
1222 } else if (new_id_len < prev_id_len) {
1223 /* New ID field is smaller than the previous */
1224 idlen_delta = prev_id_len - new_id_len;
1225
1226 /* Point to the end of the previous ID, and shift up to fill the the unused
1227 * space */
1228 pp = p_prev_id + prev_id_len;
1229 shiftup(pp - idlen_delta, pp, (uint32_t)(*p_cur_size - (pp - p_msg)));
1230
1231 *p_cur_size -= idlen_delta;
1232
1233 /* If removing the ID, make sure that length field is also removed */
1234 if (new_id_len == 0) {
1235 shiftup(p_idlen_field, p_idlen_field + 1,
1236 (uint32_t)(*p_cur_size - (p_idlen_field - p_msg - (uint32_t)1)));
1237 *p_rec &= ~NDEF_IL_MASK;
1238 *p_cur_size -= 1;
1239 }
1240 }
1241
1242 /* Save in new ID length and data */
1243 if (new_id_len) {
1244 *p_idlen_field = new_id_len;
1245
1246 if (p_new_id) memcpy(p_prev_id, p_new_id, new_id_len);
1247 }
1248
1249 return (NDEF_OK);
1250 }
1251
1252 /*******************************************************************************
1253 **
1254 ** Function NDEF_MsgRemoveRec
1255 **
1256 ** Description This function removes the record at the given
1257 ** index in the given NDEF message.
1258 **
1259 ** Returns TRUE if OK, FALSE if the index was invalid
1260 ** *p_cur_size is updated
1261 **
1262 *******************************************************************************/
NDEF_MsgRemoveRec(uint8_t * p_msg,uint32_t * p_cur_size,int32_t index)1263 tNDEF_STATUS NDEF_MsgRemoveRec(uint8_t* p_msg, uint32_t* p_cur_size,
1264 int32_t index) {
1265 uint8_t* p_rec = NDEF_MsgGetRecByIndex(p_msg, index);
1266 uint8_t *pNext, *pPrev;
1267
1268 if (!p_rec) return (NDEF_REC_NOT_FOUND);
1269
1270 /* If this is the first record in the message... */
1271 if (*p_rec & NDEF_MB_MASK) {
1272 /* Find the second record (if any) and set his 'Message Begin' bit */
1273 pNext = NDEF_MsgGetRecByIndex(p_msg, 1);
1274 if (pNext != nullptr) {
1275 *pNext |= NDEF_MB_MASK;
1276
1277 *p_cur_size -= (uint32_t)(pNext - p_msg);
1278
1279 shiftup(p_msg, pNext, *p_cur_size);
1280 } else
1281 *p_cur_size = 0; /* No more records, lenght must be zero */
1282
1283 return (NDEF_OK);
1284 }
1285
1286 /* If this is the last record in the message... */
1287 if (*p_rec & NDEF_ME_MASK) {
1288 if (index > 0) {
1289 /* Find the previous record and set his 'Message End' bit */
1290 pPrev = NDEF_MsgGetRecByIndex(p_msg, index - 1);
1291 if (pPrev == nullptr) return false;
1292
1293 *pPrev |= NDEF_ME_MASK;
1294 }
1295 *p_cur_size = (uint32_t)(p_rec - p_msg);
1296
1297 return (NDEF_OK);
1298 }
1299
1300 /* Not the first or the last... get the address of the next record */
1301 pNext = NDEF_MsgGetNextRec(p_rec);
1302 if (pNext == nullptr) return false;
1303
1304 /* We are removing p_rec, so shift from pNext to the end */
1305 shiftup(p_rec, pNext, (uint32_t)(*p_cur_size - (pNext - p_msg)));
1306
1307 *p_cur_size -= (uint32_t)(pNext - p_rec);
1308
1309 return (NDEF_OK);
1310 }
1311
1312 /*******************************************************************************
1313 **
1314 ** Function NDEF_MsgCopyAndDechunk
1315 **
1316 ** Description This function copies and de-chunks an NDEF message.
1317 ** It is assumed that the destination is at least as large
1318 ** as the source, since the source may not actually contain
1319 ** any chunks.
1320 **
1321 ** Returns The output byte count
1322 **
1323 *******************************************************************************/
NDEF_MsgCopyAndDechunk(uint8_t * p_src,uint32_t src_len,uint8_t * p_dest,uint32_t * p_out_len)1324 tNDEF_STATUS NDEF_MsgCopyAndDechunk(uint8_t* p_src, uint32_t src_len,
1325 uint8_t* p_dest, uint32_t* p_out_len) {
1326 uint32_t out_len, max_out_len;
1327 uint8_t* p_rec;
1328 uint8_t* p_prev_rec = p_dest;
1329 uint8_t *p_type, *p_id, *p_pay;
1330 uint8_t type_len, id_len, tnf;
1331 uint32_t pay_len;
1332 tNDEF_STATUS status;
1333
1334 /* First, validate the source */
1335 status = NDEF_MsgValidate(p_src, src_len, true);
1336 if (status != NDEF_OK) return (status);
1337
1338 /* The output buffer must be at least as large as the input buffer */
1339 max_out_len = src_len;
1340
1341 /* Initialize output */
1342 NDEF_MsgInit(p_dest, max_out_len, &out_len);
1343
1344 p_rec = p_src;
1345
1346 /* Now, copy record by record */
1347 while ((p_rec != nullptr) && (status == NDEF_OK)) {
1348 p_type = NDEF_RecGetType(p_rec, &tnf, &type_len);
1349 p_id = NDEF_RecGetId(p_rec, &id_len);
1350 p_pay = NDEF_RecGetPayload(p_rec, &pay_len);
1351
1352 /* If this is the continuation of a chunk, append the payload to the
1353 * previous */
1354 if (tnf == NDEF_TNF_UNCHANGED) {
1355 if (p_pay) {
1356 status = NDEF_MsgAppendPayload(p_dest, max_out_len, &out_len,
1357 p_prev_rec, p_pay, pay_len);
1358 }
1359 } else {
1360 p_prev_rec = p_dest + out_len;
1361
1362 status = NDEF_MsgAddRec(p_dest, max_out_len, &out_len, tnf, p_type,
1363 type_len, p_id, id_len, p_pay, pay_len);
1364 }
1365
1366 p_rec = NDEF_MsgGetNextRec(p_rec);
1367 }
1368
1369 *p_out_len = out_len;
1370
1371 return (status);
1372 }
1373