1 /*
2 * This file has been copied from the zcbor library.
3 * Commit zcbor 0.8.1
4 */
5
6 /*
7 * Copyright (c) 2020 Nordic Semiconductor ASA
8 *
9 * SPDX-License-Identifier: Apache-2.0
10 */
11
12 #ifndef ZCBOR_COMMON_H__
13 #define ZCBOR_COMMON_H__
14
15 #include <stdint.h>
16 #include <stdbool.h>
17 #include <stddef.h>
18 #include <string.h>
19 #include "zcbor_tags.h"
20
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24
25 #define ZCBOR_STRINGIFY_PRE(x) #x
26 #define ZCBOR_STRINGIFY(s) ZCBOR_STRINGIFY_PRE(s)
27
28 #define ZCBOR_VERSION_MAJOR 0
29 #define ZCBOR_VERSION_MINOR 8
30 #define ZCBOR_VERSION_BUGFIX 1
31
32 /** The version string with dots and not prefix. */
33 #define ZCBOR_VERSION_STR ZCBOR_STRINGIFY(ZCBOR_VERSION_MAJOR) \
34 "." ZCBOR_STRINGIFY(ZCBOR_VERSION_MINOR) \
35 "." ZCBOR_STRINGIFY(ZCBOR_VERSION_BUGFIX)
36
37 /** Monotonically increasing integer representing the version. */
38 #define ZCBOR_VERSION ((ZCBOR_VERSION_MAJOR << 24) \
39 + (ZCBOR_VERSION_MINOR << 16) \
40 + (ZCBOR_VERSION_BUGFIX << 8))
41
42 /** Convenience type that allows pointing to strings directly inside the payload
43 * without the need to copy out.
44 */
45 struct zcbor_string {
46 const uint8_t *value;
47 size_t len;
48 };
49
50
51 /** Type representing a string fragment.
52 *
53 * Don't modify any member variables, or subsequent calls may fail.
54 **/
55 struct zcbor_string_fragment {
56 struct zcbor_string fragment; ///! Location and length of the fragment.
57 size_t offset; ///! The offset in the full string at which this fragment belongs.
58 size_t total_len; ///! The total length of the string this fragment is a part of.
59 };
60
61
62 /** Size to use in struct zcbor_string_fragment when the real size is unknown. */
63 #define ZCBOR_STRING_FRAGMENT_UNKNOWN_LENGTH SIZE_MAX
64
65 #ifndef MIN
66 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
67 #endif
68
69 #ifndef MAX
70 #define MAX(a, b) (((a) < (b)) ? (b) : (a))
71 #endif
72
73 #ifndef ZCBOR_ARRAY_SIZE
74 #define ZCBOR_ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
75 #endif
76
77 /* Endian-dependent offset of smaller integer in a bigger one. */
78 #ifdef ZCBOR_BIG_ENDIAN
79 #define ZCBOR_ECPY_OFFS(dst_len, src_len) ((dst_len) - (src_len))
80 #else
81 #define ZCBOR_ECPY_OFFS(dst_len, src_len) (0)
82 #endif /* ZCBOR_BIG_ENDIAN */
83
84 #if SIZE_MAX <= UINT64_MAX
85 /** The ZCBOR_SUPPORTS_SIZE_T will be defined if processing of size_t type variables directly
86 * with zcbor_size_ functions is supported.
87 **/
88 #define ZCBOR_SUPPORTS_SIZE_T
89 #else
90 #warning "zcbor: Unsupported size_t encoding size"
91 #endif
92
93 struct zcbor_state_constant;
94
95 /** The zcbor_state_t structure is used for both encoding and decoding. */
96 typedef struct {
97 union {
98 uint8_t *payload_mut;
99 uint8_t const *payload; /**< The current place in the payload. Will be
100 updated when an element is correctly
101 processed. */
102 };
103 uint8_t const *payload_bak; /**< Temporary backup of payload. */
104 size_t elem_count; /**< The current element is part of a LIST or a MAP,
105 and this keeps count of how many elements are
106 expected. This will be checked before processing
107 and decremented if the element is correctly
108 processed. */
109 uint8_t const *payload_end; /**< The end of the payload. This will be
110 checked against payload before
111 processing each element. */
112 bool payload_moved; /**< Is set to true while the state is stored as a backup
113 if @ref zcbor_update_state is called, since that function
114 updates the payload_end of all backed-up states. */
115
116 /* This is the "decode state", the part of zcbor_state_t that is only used by zcbor_decode.c. */
117 struct {
118 bool indefinite_length_array; /**< Is set to true if the decoder is currently
119 decoding the contents of an indefinite-
120 length array. */
121 bool counting_map_elems; /**< Is set to true while the number of elements of the
122 current map are being counted. */
123 #ifdef ZCBOR_MAP_SMART_SEARCH
124 uint8_t *map_search_elem_state; /**< Optional flags to use when searching unordered
125 maps. If this is not NULL and map_elem_count
126 is non-zero, this consists of one flag per element
127 in the current map. The n-th bit can be set to 0
128 to indicate that the n-th element in the
129 map should not be searched. These are manipulated
130 via zcbor_elem_processed() or
131 zcbor_unordered_map_search(), and should not be
132 manipulated directly. */
133 #else
134 size_t map_elems_processed; /**< The number of elements of an unordered map
135 that have been processed. */
136 #endif
137 size_t map_elem_count; /**< Number of elements in the current unordered map.
138 This also serves as the number of bits (not bytes)
139 in the map_search_elem_state array (when applicable). */
140 } decode_state;
141 struct zcbor_state_constant *constant_state; /**< The part of the state that is
142 not backed up and duplicated. */
143 } zcbor_state_t;
144
145 struct zcbor_state_constant {
146 zcbor_state_t *backup_list;
147 size_t current_backup;
148 size_t num_backups;
149 int error;
150 #ifdef ZCBOR_STOP_ON_ERROR
151 bool stop_on_error;
152 #endif
153 bool manually_process_elem; /**< Whether an (unordered map) element should be automatically
154 marked as processed when found via @ref zcbor_search_map_key. */
155 #ifdef ZCBOR_MAP_SMART_SEARCH
156 uint8_t *map_search_elem_state_end; /**< The end of the @ref map_search_elem_state buffer. */
157 #endif
158 };
159
160 /** Function pointer type used with zcbor_multi_decode.
161 *
162 * This type is compatible with all decoding functions here and in the generated
163 * code, except for zcbor_multi_decode.
164 */
165 typedef bool(zcbor_encoder_t)(zcbor_state_t *, const void *);
166 typedef bool(zcbor_decoder_t)(zcbor_state_t *, void *);
167
168 /** Enumeration representing the major types available in CBOR.
169 *
170 * The major type is represented in the 3 first bits of the header byte.
171 */
172 typedef enum
173 {
174 ZCBOR_MAJOR_TYPE_PINT = 0, ///! Positive Integer
175 ZCBOR_MAJOR_TYPE_NINT = 1, ///! Negative Integer
176 ZCBOR_MAJOR_TYPE_BSTR = 2, ///! Byte String
177 ZCBOR_MAJOR_TYPE_TSTR = 3, ///! Text String
178 ZCBOR_MAJOR_TYPE_LIST = 4, ///! List
179 ZCBOR_MAJOR_TYPE_MAP = 5, ///! Map
180 ZCBOR_MAJOR_TYPE_TAG = 6, ///! Semantic Tag
181 ZCBOR_MAJOR_TYPE_SIMPLE = 7, ///! Simple values and floats
182 } zcbor_major_type_t;
183
184 /** Extract the major type, i.e. the first 3 bits of the header byte. */
185 #define ZCBOR_MAJOR_TYPE(header_byte) ((zcbor_major_type_t)(((header_byte) >> 5) & 0x7))
186
187 /** Extract the additional info, i.e. the last 5 bits of the header byte. */
188 #define ZCBOR_ADDITIONAL(header_byte) ((header_byte) & 0x1F)
189
190 /** Convenience macro for failing out of a decoding/encoding function.
191 */
192 #define ZCBOR_FAIL() \
193 do {\
194 zcbor_log("ZCBOR_FAIL "); \
195 zcbor_trace_file(state); \
196 return false; \
197 } while(0)
198
199 #define ZCBOR_FAIL_IF(expr) \
200 do {\
201 if (expr) { \
202 zcbor_log("ZCBOR_FAIL_IF(" #expr ") "); \
203 ZCBOR_FAIL(); \
204 } \
205 } while(0)
206
207 #define ZCBOR_ERR(err) \
208 do { \
209 zcbor_log("ZCBOR_ERR(%d) ", err); \
210 zcbor_error(state, err); \
211 ZCBOR_FAIL(); \
212 } while(0)
213
214 #define ZCBOR_ERR_IF(expr, err) \
215 do {\
216 if (expr) { \
217 zcbor_log("ZCBOR_ERR_IF(" #expr ", %d) ", err); \
218 ZCBOR_ERR(err); \
219 } \
220 } while(0)
221
222 #define ZCBOR_CHECK_PAYLOAD() \
223 ZCBOR_ERR_IF(state->payload >= state->payload_end, ZCBOR_ERR_NO_PAYLOAD)
224
225 #ifdef ZCBOR_STOP_ON_ERROR
226 #define ZCBOR_CHECK_ERROR() \
227 do { \
228 if (!zcbor_check_error(state)) { \
229 ZCBOR_FAIL(); \
230 } \
231 } while(0)
232 #else
233 #define ZCBOR_CHECK_ERROR()
234 #endif
235
236 #define ZCBOR_VALUE_IN_HEADER 23 ///! Values below this are encoded directly in the header.
237 #define ZCBOR_VALUE_IS_1_BYTE 24 ///! The next 1 byte contains the value.
238 #define ZCBOR_VALUE_IS_2_BYTES 25 ///! The next 2 bytes contain the value.
239 #define ZCBOR_VALUE_IS_4_BYTES 26 ///! The next 4 bytes contain the value.
240 #define ZCBOR_VALUE_IS_8_BYTES 27 ///! The next 8 bytes contain the value.
241 #define ZCBOR_VALUE_IS_INDEFINITE_LENGTH 31 ///! The list or map has indefinite length, and will instead be terminated by a 0xFF token.
242
243 #define ZCBOR_BOOL_TO_SIMPLE ((uint8_t)20) ///! In CBOR, false/true have the values 20/21
244
245 #define ZCBOR_FLAG_RESTORE 1UL ///! Restore from the backup. Overwrite the current state with the state from the backup.
246 #define ZCBOR_FLAG_CONSUME 2UL ///! Consume the backup. Remove the backup from the stack of backups.
247 #define ZCBOR_FLAG_KEEP_PAYLOAD 4UL ///! Keep the pre-restore payload after restoring.
248 #define ZCBOR_FLAG_KEEP_DECODE_STATE 8UL ///! Keep the pre-restore decode state (everything only used for decoding)
249
250 #define ZCBOR_SUCCESS 0
251 #define ZCBOR_ERR_NO_BACKUP_MEM 1
252 #define ZCBOR_ERR_NO_BACKUP_ACTIVE 2
253 #define ZCBOR_ERR_LOW_ELEM_COUNT 3
254 #define ZCBOR_ERR_HIGH_ELEM_COUNT 4
255 #define ZCBOR_ERR_INT_SIZE 5
256 #define ZCBOR_ERR_FLOAT_SIZE 6
257 #define ZCBOR_ERR_ADDITIONAL_INVAL 7 ///! > 27
258 #define ZCBOR_ERR_NO_PAYLOAD 8
259 #define ZCBOR_ERR_PAYLOAD_NOT_CONSUMED 9
260 #define ZCBOR_ERR_WRONG_TYPE 10
261 #define ZCBOR_ERR_WRONG_VALUE 11
262 #define ZCBOR_ERR_WRONG_RANGE 12
263 #define ZCBOR_ERR_ITERATIONS 13
264 #define ZCBOR_ERR_ASSERTION 14
265 #define ZCBOR_ERR_PAYLOAD_OUTDATED 15 ///! Because of a call to @ref zcbor_update_state
266 #define ZCBOR_ERR_ELEM_NOT_FOUND 16
267 #define ZCBOR_ERR_MAP_MISALIGNED 17
268 #define ZCBOR_ERR_ELEMS_NOT_PROCESSED 18
269 #define ZCBOR_ERR_NOT_AT_END 19
270 #define ZCBOR_ERR_MAP_FLAGS_NOT_AVAILABLE 20
271 #define ZCBOR_ERR_INVALID_VALUE_ENCODING 21 ///! When ZCBOR_CANONICAL is defined, and the incoming data is not encoded with minimal length.
272 #define ZCBOR_ERR_UNKNOWN 31
273
274 /** The largest possible elem_count. */
275 #define ZCBOR_MAX_ELEM_COUNT SIZE_MAX
276
277 /** Initial value for elem_count for when it just needs to be large. */
278 #define ZCBOR_LARGE_ELEM_COUNT (ZCBOR_MAX_ELEM_COUNT - 15)
279
280
281 /** Take a backup of the current state. Overwrite the current elem_count. */
282 bool zcbor_new_backup(zcbor_state_t *state, size_t new_elem_count);
283
284 /** Consult the most recent backup. In doing so, check whether elem_count is
285 * less than or equal to max_elem_count.
286 * Also, take action based on the flags (See ZCBOR_FLAG_*).
287 */
288 bool zcbor_process_backup(zcbor_state_t *state, uint32_t flags, size_t max_elem_count);
289
290 /** Convenience function for starting encoding/decoding of a union.
291 *
292 * That is, for attempting to encode, or especially decode, multiple options.
293 * Makes a new backup.
294 */
295 bool zcbor_union_start_code(zcbor_state_t *state);
296
297 /** Convenience function before encoding/decoding one element of a union.
298 *
299 * Call this before attempting each option.
300 * Restores the backup, without consuming it.
301 */
302 bool zcbor_union_elem_code(zcbor_state_t *state);
303
304 /** Convenience function before encoding/decoding one element of a union.
305 *
306 * Consumes the backup without restoring it.
307 */
308 bool zcbor_union_end_code(zcbor_state_t *state);
309
310 /** Initialize a state with backups.
311 * As long as n_states is more than 1, one of the states in the array is used
312 * as a struct zcbor_state_constant object.
313 * If there is no struct zcbor_state_constant (n_states == 1), error codes are
314 * not available.
315 * This means that you get a state with (n_states - 2) backups.
316 * payload, payload_len, elem_count, and elem_state are used to initialize the first state.
317 * The elem_state is only needed for unordered maps, when ZCBOR_MAP_SMART_SEARCH is enabled.
318 * It is ignored otherwise.
319 */
320 void zcbor_new_state(zcbor_state_t *state_array, size_t n_states,
321 const uint8_t *payload, size_t payload_len, size_t elem_count,
322 uint8_t *elem_state, size_t elem_state_bytes);
323
324 /** Do boilerplate entry function procedure.
325 * Initialize states, call function, and check the result.
326 */
327 int zcbor_entry_function(const uint8_t *payload, size_t payload_len,
328 void *result, size_t *payload_len_out, zcbor_state_t *state, zcbor_decoder_t func,
329 size_t n_states, size_t elem_count);
330
331 #ifdef ZCBOR_STOP_ON_ERROR
332 /** Check stored error and fail if present, but only if stop_on_error is true.
333 *
334 * @retval true No error found
335 * @retval false An error was found
336 */
zcbor_check_error(const zcbor_state_t * state)337 static inline bool zcbor_check_error(const zcbor_state_t *state)
338 {
339 struct zcbor_state_constant *cs = state->constant_state;
340 return !(cs && cs->stop_on_error && cs->error);
341 }
342 #endif
343
344 /** Return the current error state, replacing it with SUCCESS. */
zcbor_pop_error(zcbor_state_t * state)345 static inline int zcbor_pop_error(zcbor_state_t *state)
346 {
347 if (!state->constant_state) {
348 return ZCBOR_SUCCESS;
349 }
350 int err = state->constant_state->error;
351
352 state->constant_state->error = ZCBOR_SUCCESS;
353 return err;
354 }
355
356 /** Look at current error state without altering it */
zcbor_peek_error(const zcbor_state_t * state)357 static inline int zcbor_peek_error(const zcbor_state_t *state)
358 {
359 if (!state->constant_state) {
360 return ZCBOR_SUCCESS;
361 } else {
362 return state->constant_state->error;
363 }
364 }
365
366 /** Write the provided error to the error state. */
zcbor_error(zcbor_state_t * state,int err)367 static inline void zcbor_error(zcbor_state_t *state, int err)
368 {
369 #ifdef ZCBOR_STOP_ON_ERROR
370 if (zcbor_check_error(state))
371 #endif
372 {
373 if (state->constant_state) {
374 state->constant_state->error = err;
375 }
376 }
377 }
378
379 /** Whether the current payload is exhausted. */
zcbor_payload_at_end(const zcbor_state_t * state)380 static inline bool zcbor_payload_at_end(const zcbor_state_t *state)
381 {
382 return (state->payload == state->payload_end);
383 }
384
385 /** Update the current payload pointer (and payload_end).
386 *
387 * For use when the payload is divided into multiple chunks.
388 *
389 * This function also updates all backups to the new payload_end.
390 * This sets a flag so that @ref zcbor_process_backup fails if a backup is
391 * processed with the flag @ref ZCBOR_FLAG_RESTORE, but without the flag
392 * @ref ZCBOR_FLAG_KEEP_PAYLOAD since this would cause an invalid state.
393 *
394 * @param[inout] state The current state, will be updated with
395 * the new payload pointer.
396 * @param[in] payload The new payload chunk.
397 * @param[in] payload_len The length of the new payload chunk.
398 */
399 void zcbor_update_state(zcbor_state_t *state,
400 const uint8_t *payload, size_t payload_len);
401
402 /** Check that the provided fragments are complete and in the right order.
403 *
404 * If the total length is not known, the total_len can have the value
405 * @ref ZCBOR_STRING_FRAGMENT_UNKNOWN_LENGTH. If so, all fragments will be
406 * updated with the actual total length.
407 *
408 * @param[in] fragments An array of string fragments. Cannot be NULL.
409 * @param[in] num_fragments The number of fragments in @p fragments.
410 *
411 * @retval true If the fragments are in the right order, and there are no
412 * fragments missing.
413 * @retval false If not all fragments have the same total_len, or gaps are
414 * found, or if any fragment value is NULL.
415 */
416 bool zcbor_validate_string_fragments(struct zcbor_string_fragment *fragments,
417 size_t num_fragments);
418
419 /** Assemble the fragments into a single string.
420 *
421 * The fragments are copied in the order they appear, without regard for
422 * offset or total_len. To ensure that the fragments are correct, first
423 * validate with @ref zcbor_validate_string_fragments.
424 *
425 * @param[in] fragments An array of string fragments. Cannot be NULL.
426 * @param[in] num_fragments The number of fragments in @p fragments.
427 * @param[out] result The buffer to place the assembled string into.
428 * @param[inout] result_len In: The length of the @p result.
429 * Out: The length of the assembled string.
430 *
431 * @retval true On success.
432 * @retval false If the assembled string would be larger than the buffer.
433 * The buffer might still be written to.
434 */
435 bool zcbor_splice_string_fragments(struct zcbor_string_fragment *fragments,
436 size_t num_fragments, uint8_t *result, size_t *result_len);
437
438 /** Compare two struct zcbor_string instances.
439 *
440 * @param[in] str1 A string
441 * @param[in] str2 A string to compare to @p str1
442 *
443 * @retval true if the strings are identical
444 * @retval false if length or contents don't match, or one one or both strings is NULL.
445 */
446 bool zcbor_compare_strings(const struct zcbor_string *str1,
447 const struct zcbor_string *str2);
448
449 /** Calculate the length of a CBOR string, list, or map header.
450 *
451 * This can be used to find the start of the CBOR object when you have a
452 * pointer to the start of the contents. The function assumes that the header
453 * will be the shortest it can be.
454 *
455 * @param[in] num_elems The number of elements in the string, list, or map.
456 *
457 * @return The length of the header in bytes (1-9).
458 */
459 size_t zcbor_header_len(uint64_t value);
460
461 /** Like @ref zcbor_header_len but for integer of any size <= 8. */
462 size_t zcbor_header_len_ptr(const void *const value, size_t value_len);
463
464 /** Convert a float16 value to float32.
465 *
466 * @param[in] input The float16 value stored in a uint16_t.
467 *
468 * @return The resulting float32 value.
469 */
470 float zcbor_float16_to_32(uint16_t input);
471
472 /** Convert a float32 value to float16.
473 *
474 * @param[in] input The float32 value.
475 *
476 * @return The resulting float16 value as a uint16_t.
477 */
478 uint16_t zcbor_float32_to_16(float input);
479
480 #ifdef ZCBOR_MAP_SMART_SEARCH
zcbor_round_up(size_t x,size_t align)481 static inline size_t zcbor_round_up(size_t x, size_t align)
482 {
483 return (((x) + (align) - 1) / (align) * (align));
484 }
485
486 #define ZCBOR_BITS_PER_BYTE 8
487 /** Calculate the number of bytes needed to hold @p num_flags 1 bit flags
488 */
zcbor_flags_to_bytes(size_t num_flags)489 static inline size_t zcbor_flags_to_bytes(size_t num_flags)
490 {
491 return zcbor_round_up(num_flags, ZCBOR_BITS_PER_BYTE) / ZCBOR_BITS_PER_BYTE;
492 }
493
494 /** Calculate the number of zcbor_state_t instances needed to hold @p num_flags 1 bit flags
495 */
zcbor_flags_to_states(size_t num_flags)496 static inline size_t zcbor_flags_to_states(size_t num_flags)
497 {
498 return zcbor_round_up(num_flags, sizeof(zcbor_state_t) * ZCBOR_BITS_PER_BYTE)
499 / (sizeof(zcbor_state_t) * ZCBOR_BITS_PER_BYTE);
500 }
501
502 #define ZCBOR_FLAG_STATES(n_flags) zcbor_flags_to_states(n_flags)
503
504 #else
505 #define ZCBOR_FLAG_STATES(n_flags) 0
506 #endif
507
508 size_t strnlen(const char *, size_t);
509
510 #ifdef __cplusplus
511 }
512 #endif
513
514 #endif /* ZCBOR_COMMON_H__ */
515
