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pb_decode.c
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/* pb_decode.c -- decode a protobuf using minimal resources
*
* 2011 Petteri Aimonen <[email protected]>
*/
/* Use the GCC warn_unused_result attribute to check that all return values
* are propagated correctly. On other compilers and gcc before 3.4.0 just
* ignore the annotation.
*/
#if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
#define checkreturn
#else
#define checkreturn __attribute__((warn_unused_result))
#endif
#include "pb.h"
#include "pb_decode.h"
#include "pb_common.h"
/**************************************
* Declarations internal to this file *
**************************************/
typedef bool (*pb_decoder_t)(pb_istream_t *stream, const pb_field_t *field, void *dest) checkreturn;
static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count);
static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, pb_byte_t *buf, size_t *size);
static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter);
static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter);
static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter);
static void iter_from_extension(pb_field_iter_t *iter, pb_extension_t *extension);
static bool checkreturn default_extension_decoder(pb_istream_t *stream, pb_extension_t *extension, uint32_t tag, pb_wire_type_t wire_type);
static bool checkreturn decode_extension(pb_istream_t *stream, uint32_t tag, pb_wire_type_t wire_type, pb_field_iter_t *iter);
static bool checkreturn find_extension_field(pb_field_iter_t *iter);
static void pb_field_set_to_default(pb_field_iter_t *iter);
static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct);
static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_uvarint(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_dec_fixed_length_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
static bool checkreturn pb_skip_varint(pb_istream_t *stream);
static bool checkreturn pb_skip_string(pb_istream_t *stream);
#ifdef PB_ENABLE_MALLOC
static bool checkreturn allocate_field(pb_istream_t *stream, void *pData, size_t data_size, size_t array_size);
static bool checkreturn pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *iter);
static void pb_release_single_field(const pb_field_iter_t *iter);
#endif
/* --- Function pointers to field decoders ---
* Order in the array must match pb_action_t LTYPE numbering.
*/
static const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT] = {
&pb_dec_varint,
&pb_dec_uvarint,
&pb_dec_svarint,
&pb_dec_fixed32,
&pb_dec_fixed64,
&pb_dec_bytes,
&pb_dec_string,
&pb_dec_submessage,
NULL, /* extensions */
&pb_dec_fixed_length_bytes
};
/*******************************
* pb_istream_t implementation *
*******************************/
static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count)
{
size_t i;
const pb_byte_t *source = (const pb_byte_t*)stream->state;
stream->state = (pb_byte_t*)stream->state + count;
if (buf != NULL)
{
for (i = 0; i < count; i++)
buf[i] = source[i];
}
return true;
}
bool checkreturn pb_read(pb_istream_t *stream, pb_byte_t *buf, size_t count)
{
#ifndef PB_BUFFER_ONLY
if (buf == NULL && stream->callback != buf_read)
{
/* Skip input bytes */
pb_byte_t tmp[16];
while (count > 16)
{
if (!pb_read(stream, tmp, 16))
return false;
count -= 16;
}
return pb_read(stream, tmp, count);
}
#endif
if (stream->bytes_left < count)
PB_RETURN_ERROR(stream, "end-of-stream");
#ifndef PB_BUFFER_ONLY
if (!stream->callback(stream, buf, count))
PB_RETURN_ERROR(stream, "io error");
#else
if (!buf_read(stream, buf, count))
return false;
#endif
stream->bytes_left -= count;
return true;
}
/* Read a single byte from input stream. buf may not be NULL.
* This is an optimization for the varint decoding. */
static bool checkreturn pb_readbyte(pb_istream_t *stream, pb_byte_t *buf)
{
if (stream->bytes_left == 0)
PB_RETURN_ERROR(stream, "end-of-stream");
#ifndef PB_BUFFER_ONLY
if (!stream->callback(stream, buf, 1))
PB_RETURN_ERROR(stream, "io error");
#else
*buf = *(const pb_byte_t*)stream->state;
stream->state = (pb_byte_t*)stream->state + 1;
#endif
stream->bytes_left--;
return true;
}
pb_istream_t pb_istream_from_buffer(const pb_byte_t *buf, size_t bufsize)
{
pb_istream_t stream;
/* Cast away the const from buf without a compiler error. We are
* careful to use it only in a const manner in the callbacks.
*/
union {
void *state;
const void *c_state;
} state;
#ifdef PB_BUFFER_ONLY
stream.callback = NULL;
#else
stream.callback = &buf_read;
#endif
state.c_state = buf;
stream.state = state.state;
stream.bytes_left = bufsize;
#ifndef PB_NO_ERRMSG
stream.errmsg = NULL;
#endif
return stream;
}
/********************
* Helper functions *
********************/
bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
{
pb_byte_t byte;
uint32_t result;
if (!pb_readbyte(stream, &byte))
return false;
if ((byte & 0x80) == 0)
{
/* Quick case, 1 byte value */
result = byte;
}
else
{
/* Multibyte case */
uint_fast8_t bitpos = 7;
result = byte & 0x7F;
do
{
if (bitpos >= 32)
PB_RETURN_ERROR(stream, "varint overflow");
if (!pb_readbyte(stream, &byte))
return false;
result |= (uint32_t)(byte & 0x7F) << bitpos;
bitpos = (uint_fast8_t)(bitpos + 7);
} while (byte & 0x80);
}
*dest = result;
return true;
}
bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest)
{
pb_byte_t byte;
uint_fast8_t bitpos = 0;
uint64_t result = 0;
do
{
if (bitpos >= 64)
PB_RETURN_ERROR(stream, "varint overflow");
if (!pb_readbyte(stream, &byte))
return false;
result |= (uint64_t)(byte & 0x7F) << bitpos;
bitpos = (uint_fast8_t)(bitpos + 7);
} while (byte & 0x80);
*dest = result;
return true;
}
bool checkreturn pb_skip_varint(pb_istream_t *stream)
{
pb_byte_t byte;
do
{
if (!pb_read(stream, &byte, 1))
return false;
} while (byte & 0x80);
return true;
}
bool checkreturn pb_skip_string(pb_istream_t *stream)
{
uint32_t length;
if (!pb_decode_varint32(stream, &length))
return false;
return pb_read(stream, NULL, length);
}
bool checkreturn pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof)
{
uint32_t temp;
*eof = false;
*wire_type = (pb_wire_type_t) 0;
*tag = 0;
if (!pb_decode_varint32(stream, &temp))
{
if (stream->bytes_left == 0)
*eof = true;
return false;
}
if (temp == 0)
{
*eof = true; /* Special feature: allow 0-terminated messages. */
return false;
}
*tag = temp >> 3;
*wire_type = (pb_wire_type_t)(temp & 7);
return true;
}
bool checkreturn pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type)
{
switch (wire_type)
{
case PB_WT_VARINT: return pb_skip_varint(stream);
case PB_WT_64BIT: return pb_read(stream, NULL, 8);
case PB_WT_STRING: return pb_skip_string(stream);
case PB_WT_32BIT: return pb_read(stream, NULL, 4);
default: PB_RETURN_ERROR(stream, "invalid wire_type");
}
}
/* Read a raw value to buffer, for the purpose of passing it to callback as
* a substream. Size is maximum size on call, and actual size on return.
*/
static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, pb_byte_t *buf, size_t *size)
{
size_t max_size = *size;
switch (wire_type)
{
case PB_WT_VARINT:
*size = 0;
do
{
(*size)++;
if (*size > max_size) return false;
if (!pb_read(stream, buf, 1)) return false;
} while (*buf++ & 0x80);
return true;
case PB_WT_64BIT:
*size = 8;
return pb_read(stream, buf, 8);
case PB_WT_32BIT:
*size = 4;
return pb_read(stream, buf, 4);
default: PB_RETURN_ERROR(stream, "invalid wire_type");
}
}
/* Decode string length from stream and return a substream with limited length.
* Remember to close the substream using pb_close_string_substream().
*/
bool checkreturn pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream)
{
uint32_t size;
if (!pb_decode_varint32(stream, &size))
return false;
*substream = *stream;
if (substream->bytes_left < size)
PB_RETURN_ERROR(stream, "parent stream too short");
substream->bytes_left = size;
stream->bytes_left -= size;
return true;
}
bool checkreturn pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream)
{
if (substream->bytes_left) {
if (!pb_read(substream, NULL, substream->bytes_left))
return false;
}
stream->state = substream->state;
#ifndef PB_NO_ERRMSG
stream->errmsg = substream->errmsg;
#endif
return true;
}
/*************************
* Decode a single field *
*************************/
static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
{
pb_type_t type;
pb_decoder_t func;
type = iter->pos->type;
func = PB_DECODERS[PB_LTYPE(type)];
switch (PB_HTYPE(type))
{
case PB_HTYPE_REQUIRED:
return func(stream, iter->pos, iter->pData);
case PB_HTYPE_OPTIONAL:
if (iter->pSize != iter->pData)
*(bool*)iter->pSize = true;
return func(stream, iter->pos, iter->pData);
case PB_HTYPE_REPEATED:
if (wire_type == PB_WT_STRING
&& PB_LTYPE(type) <= PB_LTYPE_LAST_PACKABLE)
{
/* Packed array */
bool status = true;
pb_size_t *size = (pb_size_t*)iter->pSize;
pb_istream_t substream;
if (!pb_make_string_substream(stream, &substream))
return false;
while (substream.bytes_left > 0 && *size < iter->pos->array_size)
{
void *pItem = (char*)iter->pData + iter->pos->data_size * (*size);
if (!func(&substream, iter->pos, pItem))
{
status = false;
break;
}
(*size)++;
}
if (substream.bytes_left != 0)
PB_RETURN_ERROR(stream, "array overflow");
if (!pb_close_string_substream(stream, &substream))
return false;
return status;
}
else
{
/* Repeated field */
pb_size_t *size = (pb_size_t*)iter->pSize;
void *pItem = (char*)iter->pData + iter->pos->data_size * (*size);
if (*size >= iter->pos->array_size)
PB_RETURN_ERROR(stream, "array overflow");
(*size)++;
return func(stream, iter->pos, pItem);
}
case PB_HTYPE_ONEOF:
*(pb_size_t*)iter->pSize = iter->pos->tag;
if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE)
{
/* We memset to zero so that any callbacks are set to NULL.
* Then set any default values. */
memset(iter->pData, 0, iter->pos->data_size);
pb_message_set_to_defaults((const pb_field_t*)iter->pos->ptr, iter->pData);
}
return func(stream, iter->pos, iter->pData);
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
}
#ifdef PB_ENABLE_MALLOC
/* Allocate storage for the field and store the pointer at iter->pData.
* array_size is the number of entries to reserve in an array.
* Zero size is not allowed, use pb_free() for releasing.
*/
static bool checkreturn allocate_field(pb_istream_t *stream, void *pData, size_t data_size, size_t array_size)
{
void *ptr = *(void**)pData;
if (data_size == 0 || array_size == 0)
PB_RETURN_ERROR(stream, "invalid size");
/* Check for multiplication overflows.
* This code avoids the costly division if the sizes are small enough.
* Multiplication is safe as long as only half of bits are set
* in either multiplicand.
*/
{
const size_t check_limit = (size_t)1 << (sizeof(size_t) * 4);
if (data_size >= check_limit || array_size >= check_limit)
{
const size_t size_max = (size_t)-1;
if (size_max / array_size < data_size)
{
PB_RETURN_ERROR(stream, "size too large");
}
}
}
/* Allocate new or expand previous allocation */
/* Note: on failure the old pointer will remain in the structure,
* the message must be freed by caller also on error return. */
ptr = pb_realloc(ptr, array_size * data_size);
if (ptr == NULL)
PB_RETURN_ERROR(stream, "realloc failed");
*(void**)pData = ptr;
return true;
}
/* Clear a newly allocated item in case it contains a pointer, or is a submessage. */
static void initialize_pointer_field(void *pItem, pb_field_iter_t *iter)
{
if (PB_LTYPE(iter->pos->type) == PB_LTYPE_STRING ||
PB_LTYPE(iter->pos->type) == PB_LTYPE_BYTES)
{
*(void**)pItem = NULL;
}
else if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
{
pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, pItem);
}
}
#endif
static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
{
#ifndef PB_ENABLE_MALLOC
PB_UNUSED(wire_type);
PB_UNUSED(iter);
PB_RETURN_ERROR(stream, "no malloc support");
#else
pb_type_t type;
pb_decoder_t func;
type = iter->pos->type;
func = PB_DECODERS[PB_LTYPE(type)];
switch (PB_HTYPE(type))
{
case PB_HTYPE_REQUIRED:
case PB_HTYPE_OPTIONAL:
case PB_HTYPE_ONEOF:
if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE &&
*(void**)iter->pData != NULL)
{
/* Duplicate field, have to release the old allocation first. */
pb_release_single_field(iter);
}
if (PB_HTYPE(type) == PB_HTYPE_ONEOF)
{
*(pb_size_t*)iter->pSize = iter->pos->tag;
}
if (PB_LTYPE(type) == PB_LTYPE_STRING ||
PB_LTYPE(type) == PB_LTYPE_BYTES)
{
return func(stream, iter->pos, iter->pData);
}
else
{
if (!allocate_field(stream, iter->pData, iter->pos->data_size, 1))
return false;
initialize_pointer_field(*(void**)iter->pData, iter);
return func(stream, iter->pos, *(void**)iter->pData);
}
case PB_HTYPE_REPEATED:
if (wire_type == PB_WT_STRING
&& PB_LTYPE(type) <= PB_LTYPE_LAST_PACKABLE)
{
/* Packed array, multiple items come in at once. */
bool status = true;
pb_size_t *size = (pb_size_t*)iter->pSize;
size_t allocated_size = *size;
void *pItem;
pb_istream_t substream;
if (!pb_make_string_substream(stream, &substream))
return false;
while (substream.bytes_left)
{
if ((size_t)*size + 1 > allocated_size)
{
/* Allocate more storage. This tries to guess the
* number of remaining entries. Round the division
* upwards. */
allocated_size += (substream.bytes_left - 1) / iter->pos->data_size + 1;
if (!allocate_field(&substream, iter->pData, iter->pos->data_size, allocated_size))
{
status = false;
break;
}
}
/* Decode the array entry */
pItem = *(char**)iter->pData + iter->pos->data_size * (*size);
initialize_pointer_field(pItem, iter);
if (!func(&substream, iter->pos, pItem))
{
status = false;
break;
}
if (*size == PB_SIZE_MAX)
{
#ifndef PB_NO_ERRMSG
stream->errmsg = "too many array entries";
#endif
status = false;
break;
}
(*size)++;
}
if (!pb_close_string_substream(stream, &substream))
return false;
return status;
}
else
{
/* Normal repeated field, i.e. only one item at a time. */
pb_size_t *size = (pb_size_t*)iter->pSize;
void *pItem;
if (*size == PB_SIZE_MAX)
PB_RETURN_ERROR(stream, "too many array entries");
(*size)++;
if (!allocate_field(stream, iter->pData, iter->pos->data_size, *size))
return false;
pItem = *(char**)iter->pData + iter->pos->data_size * (*size - 1);
initialize_pointer_field(pItem, iter);
return func(stream, iter->pos, pItem);
}
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
#endif
}
static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
{
pb_callback_t *pCallback = (pb_callback_t*)iter->pData;
#ifdef PB_OLD_CALLBACK_STYLE
void *arg = pCallback->arg;
#else
void **arg = &(pCallback->arg);
#endif
if (pCallback->funcs.decode == NULL)
return pb_skip_field(stream, wire_type);
if (wire_type == PB_WT_STRING)
{
pb_istream_t substream;
if (!pb_make_string_substream(stream, &substream))
return false;
do
{
if (!pCallback->funcs.decode(&substream, iter->pos, arg))
PB_RETURN_ERROR(stream, "callback failed");
} while (substream.bytes_left);
if (!pb_close_string_substream(stream, &substream))
return false;
return true;
}
else
{
/* Copy the single scalar value to stack.
* This is required so that we can limit the stream length,
* which in turn allows to use same callback for packed and
* not-packed fields. */
pb_istream_t substream;
pb_byte_t buffer[10];
size_t size = sizeof(buffer);
if (!read_raw_value(stream, wire_type, buffer, &size))
return false;
substream = pb_istream_from_buffer(buffer, size);
return pCallback->funcs.decode(&substream, iter->pos, arg);
}
}
static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *iter)
{
#ifdef PB_ENABLE_MALLOC
/* When decoding an oneof field, check if there is old data that must be
* released first. */
if (PB_HTYPE(iter->pos->type) == PB_HTYPE_ONEOF)
{
if (!pb_release_union_field(stream, iter))
return false;
}
#endif
switch (PB_ATYPE(iter->pos->type))
{
case PB_ATYPE_STATIC:
return decode_static_field(stream, wire_type, iter);
case PB_ATYPE_POINTER:
return decode_pointer_field(stream, wire_type, iter);
case PB_ATYPE_CALLBACK:
return decode_callback_field(stream, wire_type, iter);
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
}
static void iter_from_extension(pb_field_iter_t *iter, pb_extension_t *extension)
{
/* Fake a field iterator for the extension field.
* It is not actually safe to advance this iterator, but decode_field
* will not even try to. */
const pb_field_t *field = (const pb_field_t*)extension->type->arg;
(void)pb_field_iter_begin(iter, field, extension->dest);
iter->pData = extension->dest;
iter->pSize = &extension->found;
if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
{
/* For pointer extensions, the pointer is stored directly
* in the extension structure. This avoids having an extra
* indirection. */
iter->pData = &extension->dest;
}
}
/* Default handler for extension fields. Expects a pb_field_t structure
* in extension->type->arg. */
static bool checkreturn default_extension_decoder(pb_istream_t *stream,
pb_extension_t *extension, uint32_t tag, pb_wire_type_t wire_type)
{
const pb_field_t *field = (const pb_field_t*)extension->type->arg;
pb_field_iter_t iter;
if (field->tag != tag)
return true;
iter_from_extension(&iter, extension);
extension->found = true;
return decode_field(stream, wire_type, &iter);
}
/* Try to decode an unknown field as an extension field. Tries each extension
* decoder in turn, until one of them handles the field or loop ends. */
static bool checkreturn decode_extension(pb_istream_t *stream,
uint32_t tag, pb_wire_type_t wire_type, pb_field_iter_t *iter)
{
pb_extension_t *extension = *(pb_extension_t* const *)iter->pData;
size_t pos = stream->bytes_left;
while (extension != NULL && pos == stream->bytes_left)
{
bool status;
if (extension->type->decode)
status = extension->type->decode(stream, extension, tag, wire_type);
else
status = default_extension_decoder(stream, extension, tag, wire_type);
if (!status)
return false;
extension = extension->next;
}
return true;
}
/* Step through the iterator until an extension field is found or until all
* entries have been checked. There can be only one extension field per
* message. Returns false if no extension field is found. */
static bool checkreturn find_extension_field(pb_field_iter_t *iter)
{
const pb_field_t *start = iter->pos;
do {
if (PB_LTYPE(iter->pos->type) == PB_LTYPE_EXTENSION)
return true;
(void)pb_field_iter_next(iter);
} while (iter->pos != start);
return false;
}
/* Initialize message fields to default values, recursively */
static void pb_field_set_to_default(pb_field_iter_t *iter)
{
pb_type_t type;
type = iter->pos->type;
if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
{
pb_extension_t *ext = *(pb_extension_t* const *)iter->pData;
while (ext != NULL)
{
pb_field_iter_t ext_iter;
ext->found = false;
iter_from_extension(&ext_iter, ext);
pb_field_set_to_default(&ext_iter);
ext = ext->next;
}
}
else if (PB_ATYPE(type) == PB_ATYPE_STATIC)
{
bool init_data = true;
if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && iter->pSize != iter->pData)
{
/* Set has_field to false. Still initialize the optional field
* itself also. */
*(bool*)iter->pSize = false;
}
else if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
PB_HTYPE(type) == PB_HTYPE_ONEOF)
{
/* REPEATED: Set array count to 0, no need to initialize contents.
ONEOF: Set which_field to 0. */
*(pb_size_t*)iter->pSize = 0;
init_data = false;
}
if (init_data)
{
if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
{
/* Initialize submessage to defaults */
pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, iter->pData);
}
else if (iter->pos->ptr != NULL)
{
/* Initialize to default value */
memcpy(iter->pData, iter->pos->ptr, iter->pos->data_size);
}
else
{
/* Initialize to zeros */
memset(iter->pData, 0, iter->pos->data_size);
}
}
}
else if (PB_ATYPE(type) == PB_ATYPE_POINTER)
{
/* Initialize the pointer to NULL. */
*(void**)iter->pData = NULL;
/* Initialize array count to 0. */
if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
PB_HTYPE(type) == PB_HTYPE_ONEOF)
{
*(pb_size_t*)iter->pSize = 0;
}
}
else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
{
/* Don't overwrite callback */
}
}
static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct)
{
pb_field_iter_t iter;
if (!pb_field_iter_begin(&iter, fields, dest_struct))
return; /* Empty message type */
do
{
pb_field_set_to_default(&iter);
} while (pb_field_iter_next(&iter));
}
/*********************
* Decode all fields *
*********************/
bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
{
uint32_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 31) / 32] = {0, 0};
const uint32_t allbits = ~(uint32_t)0;
uint32_t extension_range_start = 0;
pb_field_iter_t iter;
/* Return value ignored, as empty message types will be correctly handled by
* pb_field_iter_find() anyway. */
(void)pb_field_iter_begin(&iter, fields, dest_struct);
while (stream->bytes_left)
{
uint32_t tag;
pb_wire_type_t wire_type;
bool eof;
if (!pb_decode_tag(stream, &wire_type, &tag, &eof))
{
if (eof)
break;
else
return false;
}
if (!pb_field_iter_find(&iter, tag))
{
/* No match found, check if it matches an extension. */
if (tag >= extension_range_start)
{
if (!find_extension_field(&iter))
extension_range_start = (uint32_t)-1;
else
extension_range_start = iter.pos->tag;
if (tag >= extension_range_start)
{
size_t pos = stream->bytes_left;
if (!decode_extension(stream, tag, wire_type, &iter))
return false;
if (pos != stream->bytes_left)
{
/* The field was handled */
continue;
}
}
}
/* No match found, skip data */
if (!pb_skip_field(stream, wire_type))
return false;
continue;
}
if (PB_HTYPE(iter.pos->type) == PB_HTYPE_REQUIRED
&& iter.required_field_index < PB_MAX_REQUIRED_FIELDS)
{
uint32_t tmp = ((uint32_t)1 << (iter.required_field_index & 31));
fields_seen[iter.required_field_index >> 5] |= tmp;
}
if (!decode_field(stream, wire_type, &iter))
return false;
}
/* Check that all required fields were present. */
{
/* First figure out the number of required fields by
* seeking to the end of the field array. Usually we
* are already close to end after decoding.
*/
unsigned req_field_count;
pb_type_t last_type;
unsigned i;
do {
req_field_count = iter.required_field_index;
last_type = iter.pos->type;
} while (pb_field_iter_next(&iter));
/* Fixup if last field was also required. */
if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag != 0)
req_field_count++;
if (req_field_count > PB_MAX_REQUIRED_FIELDS)
req_field_count = PB_MAX_REQUIRED_FIELDS;
if (req_field_count > 0)
{
/* Check the whole words */
for (i = 0; i < (req_field_count >> 5); i++)
{
if (fields_seen[i] != allbits)
PB_RETURN_ERROR(stream, "missing required field");
}
/* Check the remaining bits (if any) */
if ((req_field_count & 31) != 0)
{
if (fields_seen[req_field_count >> 5] !=
(allbits >> (32 - (req_field_count & 31))))
{
PB_RETURN_ERROR(stream, "missing required field");
}
}
}
}
return true;
}
bool checkreturn pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
{
bool status;
pb_message_set_to_defaults(fields, dest_struct);
status = pb_decode_noinit(stream, fields, dest_struct);
#ifdef PB_ENABLE_MALLOC
if (!status)
pb_release(fields, dest_struct);
#endif
return status;
}
bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct)
{
pb_istream_t substream;
bool status;
if (!pb_make_string_substream(stream, &substream))
return false;
status = pb_decode(&substream, fields, dest_struct);
if (!pb_close_string_substream(stream, &substream))
return false;
return status;
}
#ifdef PB_ENABLE_MALLOC
/* Given an oneof field, if there has already been a field inside this oneof,
* release it before overwriting with a different one. */
static bool pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *iter)
{
pb_size_t old_tag = *(pb_size_t*)iter->pSize; /* Previous which_ value */
pb_size_t new_tag = iter->pos->tag; /* New which_ value */