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