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1 /* Common parts of the nanopb library. Most of these are quite low-level
2  * stuff. For the high-level interface, see pb_encode.h and pb_decode.h.
3  */
4 
5 #ifndef _PB_H_
6 #define _PB_H_
7 
8 /*****************************************************************
9  * Nanopb compilation time options. You can change these here by *
10  * uncommenting the lines, or on the compiler command line.      *
11  *****************************************************************/
12 
13 /* Enable support for dynamically allocated fields */
14 /* #define PB_ENABLE_MALLOC 1 */
15 
16 /* Define this if your CPU architecture is big endian, i.e. it
17  * stores the most-significant byte first. */
18 /* #define __BIG_ENDIAN__ 1 */
19 
20 /* Increase the number of required fields that are tracked.
21  * A compiler warning will tell if you need this. */
22 /* #define PB_MAX_REQUIRED_FIELDS 256 */
23 
24 /* Add support for tag numbers > 255 and fields larger than 255 bytes. */
25 /* #define PB_FIELD_16BIT 1 */
26 
27 /* Add support for tag numbers > 65536 and fields larger than 65536 bytes. */
28 /* #define PB_FIELD_32BIT 1 */
29 
30 /* Disable support for error messages in order to save some code space. */
31 /* #define PB_NO_ERRMSG 1 */
32 
33 /* Disable support for custom streams (support only memory buffers). */
34 /* #define PB_BUFFER_ONLY 1 */
35 
36 /* Switch back to the old-style callback function signature.
37  * This was the default until nanopb-0.2.1. */
38 /* #define PB_OLD_CALLBACK_STYLE */
39 
40 
41 /******************************************************************
42  * You usually don't need to change anything below this line.     *
43  * Feel free to look around and use the defined macros, though.   *
44  ******************************************************************/
45 
46 
47 /* Version of the nanopb library. Just in case you want to check it in
48  * your own program. */
49 #define NANOPB_VERSION nanopb-0.2.8-dev
50 
51 /* Include all the system headers needed by nanopb. You will need the
52  * definitions of the following:
53  * - strlen, memcpy, memset functions
54  * - [u]int8_t, [u]int16_t, [u]int32_t, [u]int64_t
55  * - size_t
56  * - bool
57  *
58  * If you don't have the standard header files, you can instead provide
59  * a custom header that defines or includes all this. In that case,
60  * define PB_SYSTEM_HEADER to the path of this file.
61  */
62 #ifdef PB_SYSTEM_HEADER
63 #include PB_SYSTEM_HEADER
64 #else
65 #include <stdint.h>
66 #include <stddef.h>
67 #include <stdbool.h>
68 #include <string.h>
69 
70 #ifdef PB_ENABLE_MALLOC
71 #include <stdlib.h>
72 #endif
73 #endif
74 
75 /* Macro for defining packed structures (compiler dependent).
76  * This just reduces memory requirements, but is not required.
77  */
78 #if defined(__GNUC__) || defined(__clang__)
79     /* For GCC and clang */
80 #   define PB_PACKED_STRUCT_START
81 #   define PB_PACKED_STRUCT_END
82 #   define pb_packed __attribute__((packed))
83 #elif defined(__ICCARM__)
84     /* For IAR ARM compiler */
85 #   define PB_PACKED_STRUCT_START _Pragma("pack(push, 1)")
86 #   define PB_PACKED_STRUCT_END _Pragma("pack(pop)")
87 #   define pb_packed
88 #elif defined(_MSC_VER) && (_MSC_VER >= 1500)
89     /* For Microsoft Visual C++ */
90 #   define PB_PACKED_STRUCT_START __pragma(pack(push, 1))
91 #   define PB_PACKED_STRUCT_END __pragma(pack(pop))
92 #   define pb_packed
93 #else
94     /* Unknown compiler */
95 #   define PB_PACKED_STRUCT_START
96 #   define PB_PACKED_STRUCT_END
97 #   define pb_packed
98 #endif
99 
100 /* Handly macro for suppressing unreferenced-parameter compiler warnings. */
101 #ifndef UNUSED
102 #define UNUSED(x) (void)(x)
103 #endif
104 
105 /* Compile-time assertion, used for checking compatible compilation options.
106  * If this does not work properly on your compiler, use #define STATIC_ASSERT
107  * to disable it.
108  *
109  * But before doing that, check carefully the error message / place where it
110  * comes from to see if the error has a real cause. Unfortunately the error
111  * message is not always very clear to read, but you can see the reason better
112  * in the place where the STATIC_ASSERT macro was called.
113  */
114 #ifndef STATIC_ASSERT
115 #define STATIC_ASSERT(COND,MSG) typedef char STATIC_ASSERT_MSG(MSG, __LINE__, __COUNTER__)[(COND)?1:-1];
116 #define STATIC_ASSERT_MSG(MSG, LINE, COUNTER) STATIC_ASSERT_MSG_(MSG, LINE, COUNTER)
117 #define STATIC_ASSERT_MSG_(MSG, LINE, COUNTER) static_assertion_##MSG##LINE##COUNTER
118 #endif
119 
120 /* Number of required fields to keep track of. */
121 #ifndef PB_MAX_REQUIRED_FIELDS
122 #define PB_MAX_REQUIRED_FIELDS 64
123 #endif
124 
125 #if PB_MAX_REQUIRED_FIELDS < 64
126 #error You should not lower PB_MAX_REQUIRED_FIELDS from the default value (64).
127 #endif
128 
129 /* List of possible field types. These are used in the autogenerated code.
130  * Least-significant 4 bits tell the scalar type
131  * Most-significant 4 bits specify repeated/required/packed etc.
132  */
133 
134 typedef uint8_t pb_type_t;
135 
136 /**** Field data types ****/
137 
138 /* Numeric types */
139 #define PB_LTYPE_VARINT  0x00 /* int32, int64, enum, bool */
140 #define PB_LTYPE_UVARINT 0x01 /* uint32, uint64 */
141 #define PB_LTYPE_SVARINT 0x02 /* sint32, sint64 */
142 #define PB_LTYPE_FIXED32 0x03 /* fixed32, sfixed32, float */
143 #define PB_LTYPE_FIXED64 0x04 /* fixed64, sfixed64, double */
144 
145 /* Marker for last packable field type. */
146 #define PB_LTYPE_LAST_PACKABLE 0x04
147 
148 /* Byte array with pre-allocated buffer.
149  * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
150 #define PB_LTYPE_BYTES 0x05
151 
152 /* String with pre-allocated buffer.
153  * data_size is the maximum length. */
154 #define PB_LTYPE_STRING 0x06
155 
156 /* Submessage
157  * submsg_fields is pointer to field descriptions */
158 #define PB_LTYPE_SUBMESSAGE 0x07
159 
160 /* Extension pseudo-field
161  * The field contains a pointer to pb_extension_t */
162 #define PB_LTYPE_EXTENSION 0x08
163 
164 /* Number of declared LTYPES */
165 #define PB_LTYPES_COUNT 9
166 #define PB_LTYPE_MASK 0x0F
167 
168 /**** Field repetition rules ****/
169 
170 #define PB_HTYPE_REQUIRED 0x00
171 #define PB_HTYPE_OPTIONAL 0x10
172 #define PB_HTYPE_REPEATED 0x20
173 #define PB_HTYPE_MASK     0x30
174 
175 /**** Field allocation types ****/
176 
177 #define PB_ATYPE_STATIC   0x00
178 #define PB_ATYPE_POINTER  0x80
179 #define PB_ATYPE_CALLBACK 0x40
180 #define PB_ATYPE_MASK     0xC0
181 
182 #define PB_ATYPE(x) ((x) & PB_ATYPE_MASK)
183 #define PB_HTYPE(x) ((x) & PB_HTYPE_MASK)
184 #define PB_LTYPE(x) ((x) & PB_LTYPE_MASK)
185 
186 /* Data type used for storing sizes of struct fields
187  * and array counts.
188  */
189 #if defined(PB_FIELD_32BIT)
190     typedef uint32_t pb_size_t;
191     typedef int32_t pb_ssize_t;
192 #elif defined(PB_FIELD_16BIT)
193     typedef uint16_t pb_size_t;
194     typedef int16_t pb_ssize_t;
195 #else
196     typedef uint8_t pb_size_t;
197     typedef int8_t pb_ssize_t;
198 #endif
199 
200 /* This structure is used in auto-generated constants
201  * to specify struct fields.
202  * You can change field sizes if you need structures
203  * larger than 256 bytes or field tags larger than 256.
204  * The compiler should complain if your .proto has such
205  * structures. Fix that by defining PB_FIELD_16BIT or
206  * PB_FIELD_32BIT.
207  */
208 PB_PACKED_STRUCT_START
209 typedef struct _pb_field_t pb_field_t;
210 struct _pb_field_t {
211     pb_size_t tag;
212     pb_type_t type;
213     pb_size_t data_offset; /* Offset of field data, relative to previous field. */
214     pb_ssize_t size_offset; /* Offset of array size or has-boolean, relative to data */
215     pb_size_t data_size; /* Data size in bytes for a single item */
216     pb_size_t array_size; /* Maximum number of entries in array */
217 
218     /* Field definitions for submessage
219      * OR default value for all other non-array, non-callback types
220      * If null, then field will zeroed. */
221     const void *ptr;
222 } pb_packed;
223 PB_PACKED_STRUCT_END
224 
225 /* Make sure that the standard integer types are of the expected sizes.
226  * All kinds of things may break otherwise.. atleast all fixed* types.
227  *
228  * If you get errors here, it probably means that your stdint.h is not
229  * correct for your platform.
230  */
231 STATIC_ASSERT(sizeof(int8_t) == 1, INT8_T_WRONG_SIZE)
232 STATIC_ASSERT(sizeof(uint8_t) == 1, UINT8_T_WRONG_SIZE)
233 STATIC_ASSERT(sizeof(int16_t) == 2, INT16_T_WRONG_SIZE)
234 STATIC_ASSERT(sizeof(uint16_t) == 2, UINT16_T_WRONG_SIZE)
235 STATIC_ASSERT(sizeof(int32_t) == 4, INT32_T_WRONG_SIZE)
236 STATIC_ASSERT(sizeof(uint32_t) == 4, UINT32_T_WRONG_SIZE)
237 STATIC_ASSERT(sizeof(int64_t) == 8, INT64_T_WRONG_SIZE)
238 STATIC_ASSERT(sizeof(uint64_t) == 8, UINT64_T_WRONG_SIZE)
239 
240 /* This structure is used for 'bytes' arrays.
241  * It has the number of bytes in the beginning, and after that an array.
242  * Note that actual structs used will have a different length of bytes array.
243  */
244 #define PB_BYTES_ARRAY_T(n) struct { size_t size; uint8_t bytes[n]; }
245 #define PB_BYTES_ARRAY_T_ALLOCSIZE(n) ((size_t)n + offsetof(pb_bytes_array_t, bytes))
246 
247 struct _pb_bytes_array_t {
248     size_t size;
249     uint8_t bytes[1];
250 };
251 typedef struct _pb_bytes_array_t pb_bytes_array_t;
252 
253 /* This structure is used for giving the callback function.
254  * It is stored in the message structure and filled in by the method that
255  * calls pb_decode.
256  *
257  * The decoding callback will be given a limited-length stream
258  * If the wire type was string, the length is the length of the string.
259  * If the wire type was a varint/fixed32/fixed64, the length is the length
260  * of the actual value.
261  * The function may be called multiple times (especially for repeated types,
262  * but also otherwise if the message happens to contain the field multiple
263  * times.)
264  *
265  * The encoding callback will receive the actual output stream.
266  * It should write all the data in one call, including the field tag and
267  * wire type. It can write multiple fields.
268  *
269  * The callback can be null if you want to skip a field.
270  */
271 typedef struct _pb_istream_t pb_istream_t;
272 typedef struct _pb_ostream_t pb_ostream_t;
273 typedef struct _pb_callback_t pb_callback_t;
274 struct _pb_callback_t {
275 #ifdef PB_OLD_CALLBACK_STYLE
276     /* Deprecated since nanopb-0.2.1 */
277     union {
278         bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
279         bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
280     } funcs;
281 #else
282     /* New function signature, which allows modifying arg contents in callback. */
283     union {
284         bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void **arg);
285         bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
286     } funcs;
287 #endif
288 
289     /* Free arg for use by callback */
290     void *arg;
291 };
292 
293 /* Wire types. Library user needs these only in encoder callbacks. */
294 typedef enum {
295     PB_WT_VARINT = 0,
296     PB_WT_64BIT  = 1,
297     PB_WT_STRING = 2,
298     PB_WT_32BIT  = 5
299 } pb_wire_type_t;
300 
301 /* Structure for defining the handling of unknown/extension fields.
302  * Usually the pb_extension_type_t structure is automatically generated,
303  * while the pb_extension_t structure is created by the user. However,
304  * if you want to catch all unknown fields, you can also create a custom
305  * pb_extension_type_t with your own callback.
306  */
307 typedef struct _pb_extension_type_t pb_extension_type_t;
308 typedef struct _pb_extension_t pb_extension_t;
309 struct _pb_extension_type_t {
310     /* Called for each unknown field in the message.
311      * If you handle the field, read off all of its data and return true.
312      * If you do not handle the field, do not read anything and return true.
313      * If you run into an error, return false.
314      * Set to NULL for default handler.
315      */
316     bool (*decode)(pb_istream_t *stream, pb_extension_t *extension,
317                    uint32_t tag, pb_wire_type_t wire_type);
318 
319     /* Called once after all regular fields have been encoded.
320      * If you have something to write, do so and return true.
321      * If you do not have anything to write, just return true.
322      * If you run into an error, return false.
323      * Set to NULL for default handler.
324      */
325     bool (*encode)(pb_ostream_t *stream, const pb_extension_t *extension);
326 
327     /* Free field for use by the callback. */
328     const void *arg;
329 };
330 
331 struct _pb_extension_t {
332     /* Type describing the extension field. Usually you'll initialize
333      * this to a pointer to the automatically generated structure. */
334     const pb_extension_type_t *type;
335 
336     /* Destination for the decoded data. This must match the datatype
337      * of the extension field. */
338     void *dest;
339 
340     /* Pointer to the next extension handler, or NULL.
341      * If this extension does not match a field, the next handler is
342      * automatically called. */
343     pb_extension_t *next;
344 
345     /* The decoder sets this to true if the extension was found.
346      * Ignored for encoding. */
347     bool found;
348 };
349 
350 /* Memory allocation functions to use. You can define pb_realloc and
351  * pb_free to custom functions if you want. */
352 #ifdef PB_ENABLE_MALLOC
353 #   ifndef pb_realloc
354 #       define pb_realloc(ptr, size) realloc(ptr, size)
355 #   endif
356 #   ifndef pb_free
357 #       define pb_free(ptr) free(ptr)
358 #   endif
359 #endif
360 
361 /* These macros are used to declare pb_field_t's in the constant array. */
362 /* Size of a structure member, in bytes. */
363 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
364 /* Number of entries in an array. */
365 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
366 /* Delta from start of one member to the start of another member. */
367 #define pb_delta(st, m1, m2) ((int)offsetof(st, m1) - (int)offsetof(st, m2))
368 /* Marks the end of the field list */
369 #define PB_LAST_FIELD {0,(pb_type_t) 0,0,0,0,0,0}
370 
371 /* Macros for filling in the data_offset field */
372 /* data_offset for first field in a message */
373 #define PB_DATAOFFSET_FIRST(st, m1, m2) (offsetof(st, m1))
374 /* data_offset for subsequent fields */
375 #define PB_DATAOFFSET_OTHER(st, m1, m2) (offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
376 /* Choose first/other based on m1 == m2 (deprecated, remains for backwards compatibility) */
377 #define PB_DATAOFFSET_CHOOSE(st, m1, m2) (int)(offsetof(st, m1) == offsetof(st, m2) \
378                                   ? PB_DATAOFFSET_FIRST(st, m1, m2) \
379                                   : PB_DATAOFFSET_OTHER(st, m1, m2))
380 
381 /* Required fields are the simplest. They just have delta (padding) from
382  * previous field end, and the size of the field. Pointer is used for
383  * submessages and default values.
384  */
385 #define PB_REQUIRED_STATIC(tag, st, m, fd, ltype, ptr) \
386     {tag, PB_ATYPE_STATIC | PB_HTYPE_REQUIRED | ltype, \
387     fd, 0, pb_membersize(st, m), 0, ptr}
388 
389 /* Optional fields add the delta to the has_ variable. */
390 #define PB_OPTIONAL_STATIC(tag, st, m, fd, ltype, ptr) \
391     {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
392     fd, \
393     pb_delta(st, has_ ## m, m), \
394     pb_membersize(st, m), 0, ptr}
395 
396 /* Repeated fields have a _count field and also the maximum number of entries. */
397 #define PB_REPEATED_STATIC(tag, st, m, fd, ltype, ptr) \
398     {tag, PB_ATYPE_STATIC | PB_HTYPE_REPEATED | ltype, \
399     fd, \
400     pb_delta(st, m ## _count, m), \
401     pb_membersize(st, m[0]), \
402     pb_arraysize(st, m), ptr}
403 
404 /* Allocated fields carry the size of the actual data, not the pointer */
405 #define PB_REQUIRED_POINTER(tag, st, m, fd, ltype, ptr) \
406     {tag, PB_ATYPE_POINTER | PB_HTYPE_REQUIRED | ltype, \
407     fd, 0, pb_membersize(st, m[0]), 0, ptr}
408 
409 /* Optional fields don't need a has_ variable, as information would be redundant */
410 #define PB_OPTIONAL_POINTER(tag, st, m, fd, ltype, ptr) \
411     {tag, PB_ATYPE_POINTER | PB_HTYPE_OPTIONAL | ltype, \
412     fd, 0, pb_membersize(st, m[0]), 0, ptr}
413 
414 /* Repeated fields have a _count field and a pointer to array of pointers */
415 #define PB_REPEATED_POINTER(tag, st, m, fd, ltype, ptr) \
416     {tag, PB_ATYPE_POINTER | PB_HTYPE_REPEATED | ltype, \
417     fd, pb_delta(st, m ## _count, m), \
418     pb_membersize(st, m[0]), 0, ptr}
419 
420 /* Callbacks are much like required fields except with special datatype. */
421 #define PB_REQUIRED_CALLBACK(tag, st, m, fd, ltype, ptr) \
422     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REQUIRED | ltype, \
423     fd, 0, pb_membersize(st, m), 0, ptr}
424 
425 #define PB_OPTIONAL_CALLBACK(tag, st, m, fd, ltype, ptr) \
426     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
427     fd, 0, pb_membersize(st, m), 0, ptr}
428 
429 #define PB_REPEATED_CALLBACK(tag, st, m, fd, ltype, ptr) \
430     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_REPEATED | ltype, \
431     fd, 0, pb_membersize(st, m), 0, ptr}
432 
433 /* Optional extensions don't have the has_ field, as that would be redundant. */
434 #define PB_OPTEXT_STATIC(tag, st, m, fd, ltype, ptr) \
435     {tag, PB_ATYPE_STATIC | PB_HTYPE_OPTIONAL | ltype, \
436     0, \
437     0, \
438     pb_membersize(st, m), 0, ptr}
439 
440 #define PB_OPTEXT_CALLBACK(tag, st, m, fd, ltype, ptr) \
441     {tag, PB_ATYPE_CALLBACK | PB_HTYPE_OPTIONAL | ltype, \
442     0, 0, pb_membersize(st, m), 0, ptr}
443 
444 /* The mapping from protobuf types to LTYPEs is done using these macros. */
445 #define PB_LTYPE_MAP_BOOL       PB_LTYPE_VARINT
446 #define PB_LTYPE_MAP_BYTES      PB_LTYPE_BYTES
447 #define PB_LTYPE_MAP_DOUBLE     PB_LTYPE_FIXED64
448 #define PB_LTYPE_MAP_ENUM       PB_LTYPE_VARINT
449 #define PB_LTYPE_MAP_FIXED32    PB_LTYPE_FIXED32
450 #define PB_LTYPE_MAP_FIXED64    PB_LTYPE_FIXED64
451 #define PB_LTYPE_MAP_FLOAT      PB_LTYPE_FIXED32
452 #define PB_LTYPE_MAP_INT32      PB_LTYPE_VARINT
453 #define PB_LTYPE_MAP_INT64      PB_LTYPE_VARINT
454 #define PB_LTYPE_MAP_MESSAGE    PB_LTYPE_SUBMESSAGE
455 #define PB_LTYPE_MAP_SFIXED32   PB_LTYPE_FIXED32
456 #define PB_LTYPE_MAP_SFIXED64   PB_LTYPE_FIXED64
457 #define PB_LTYPE_MAP_SINT32     PB_LTYPE_SVARINT
458 #define PB_LTYPE_MAP_SINT64     PB_LTYPE_SVARINT
459 #define PB_LTYPE_MAP_STRING     PB_LTYPE_STRING
460 #define PB_LTYPE_MAP_UINT32     PB_LTYPE_UVARINT
461 #define PB_LTYPE_MAP_UINT64     PB_LTYPE_UVARINT
462 #define PB_LTYPE_MAP_EXTENSION  PB_LTYPE_EXTENSION
463 
464 /* This is the actual macro used in field descriptions.
465  * It takes these arguments:
466  * - Field tag number
467  * - Field type:   BOOL, BYTES, DOUBLE, ENUM, FIXED32, FIXED64,
468  *                 FLOAT, INT32, INT64, MESSAGE, SFIXED32, SFIXED64
469  *                 SINT32, SINT64, STRING, UINT32, UINT64 or EXTENSION
470  * - Field rules:  REQUIRED, OPTIONAL or REPEATED
471  * - Allocation:   STATIC or CALLBACK
472  * - Message name
473  * - Field name
474  * - Previous field name (or field name again for first field)
475  * - Pointer to default value or submsg fields.
476  */
477 
478 #define PB_FIELD(tag, type, rules, allocation, message, field, prevfield, ptr) \
479     PB_ ## rules ## _ ## allocation(tag, message, field, \
480         PB_DATAOFFSET_CHOOSE(message, field, prevfield), \
481         PB_LTYPE_MAP_ ## type, ptr)
482 
483 /* This is a new version of the macro used by nanopb generator from
484  * version 0.2.3 onwards. It avoids the use of a ternary expression in
485  * the initialization, which confused some compilers.
486  *
487  * - Placement: FIRST or OTHER, depending on if this is the first field in structure.
488  *
489  */
490 #define PB_FIELD2(tag, type, rules, allocation, placement, message, field, prevfield, ptr) \
491     PB_ ## rules ## _ ## allocation(tag, message, field, \
492         PB_DATAOFFSET_ ## placement(message, field, prevfield), \
493         PB_LTYPE_MAP_ ## type, ptr)
494 
495 
496 /* These macros are used for giving out error messages.
497  * They are mostly a debugging aid; the main error information
498  * is the true/false return value from functions.
499  * Some code space can be saved by disabling the error
500  * messages if not used.
501  */
502 #ifdef PB_NO_ERRMSG
503 #define PB_RETURN_ERROR(stream,msg) \
504     do {\
505         UNUSED(stream); \
506         return false; \
507     } while(0)
508 #define PB_GET_ERROR(stream) "(errmsg disabled)"
509 #else
510 #define PB_RETURN_ERROR(stream,msg) \
511     do {\
512         if ((stream)->errmsg == NULL) \
513             (stream)->errmsg = (msg); \
514         return false; \
515     } while(0)
516 #define PB_GET_ERROR(stream) ((stream)->errmsg ? (stream)->errmsg : "(none)")
517 #endif
518 
519 #endif
520