mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-23 14:58:09 +00:00
91 lines
2.7 KiB
C
91 lines
2.7 KiB
C
/* pb_common.c: Common support functions for pb_encode.c and pb_decode.c.
|
|
*
|
|
* 2014 Petteri Aimonen <jpa@kapsi.fi>
|
|
*/
|
|
|
|
#include "pb_common.h"
|
|
|
|
bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct)
|
|
{
|
|
iter->start = fields;
|
|
iter->pos = fields;
|
|
iter->required_field_index = 0;
|
|
iter->dest_struct = dest_struct;
|
|
iter->pData = (char*)dest_struct + iter->pos->data_offset;
|
|
iter->pSize = (char*)iter->pData + iter->pos->size_offset;
|
|
|
|
return (iter->pos->tag != 0);
|
|
}
|
|
|
|
bool pb_field_iter_next(pb_field_iter_t *iter)
|
|
{
|
|
const pb_field_t *prev_field = iter->pos;
|
|
|
|
if (prev_field->tag == 0)
|
|
{
|
|
/* Handle empty message types, where the first field is already the terminator.
|
|
* In other cases, the iter->pos never points to the terminator. */
|
|
return false;
|
|
}
|
|
|
|
iter->pos++;
|
|
|
|
if (iter->pos->tag == 0)
|
|
{
|
|
/* Wrapped back to beginning, reinitialize */
|
|
(void)pb_field_iter_begin(iter, iter->start, iter->dest_struct);
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
/* Increment the pointers based on previous field size */
|
|
size_t prev_size = prev_field->data_size;
|
|
|
|
if (PB_ATYPE(prev_field->type) == PB_ATYPE_STATIC &&
|
|
PB_HTYPE(prev_field->type) == PB_HTYPE_REPEATED)
|
|
{
|
|
/* In static arrays, the data_size tells the size of a single entry and
|
|
* array_size is the number of entries */
|
|
prev_size *= prev_field->array_size;
|
|
}
|
|
else if (PB_ATYPE(prev_field->type) == PB_ATYPE_POINTER)
|
|
{
|
|
/* Pointer fields always have a constant size in the main structure.
|
|
* The data_size only applies to the dynamically allocated area. */
|
|
prev_size = sizeof(void*);
|
|
}
|
|
|
|
if (PB_HTYPE(prev_field->type) == PB_HTYPE_REQUIRED)
|
|
{
|
|
/* Count the required fields, in order to check their presence in the
|
|
* decoder. */
|
|
iter->required_field_index++;
|
|
}
|
|
|
|
iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
|
|
iter->pSize = (char*)iter->pData + iter->pos->size_offset;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag)
|
|
{
|
|
const pb_field_t *start = iter->pos;
|
|
|
|
do {
|
|
if (iter->pos->tag == tag &&
|
|
PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION)
|
|
{
|
|
/* Found the wanted field */
|
|
return true;
|
|
}
|
|
|
|
(void)pb_field_iter_next(iter);
|
|
} while (iter->pos != start);
|
|
|
|
/* Searched all the way back to start, and found nothing. */
|
|
return false;
|
|
}
|
|
|
|
|