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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 *
**************************************/
static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count);
static bool checkreturn pb_decode_varint32_eof(pb_istream_t *stream, uint32_t *dest, bool *eof);
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_basic_field(pb_istream_t *stream, pb_field_iter_t *field);
static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field);
static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field);
static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field);
static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field);
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 bool pb_message_set_to_defaults(pb_field_iter_t *iter);
static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_iter_t *field);
static bool checkreturn pb_dec_fixed(pb_istream_t *stream, const pb_field_iter_t *field);
static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_iter_t *field);
static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_iter_t *field);
static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_iter_t *field);
static bool checkreturn pb_dec_fixed_length_bytes(pb_istream_t *stream, const pb_field_iter_t *field);
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 void initialize_pointer_field(void *pItem, pb_field_iter_t *field);
static bool checkreturn pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *field);
static void pb_release_single_field(pb_field_iter_t *field);
#endif
#ifdef PB_WITHOUT_64BIT
#define pb_int64_t int32_t
#define pb_uint64_t uint32_t
#else
#define pb_int64_t int64_t
#define pb_uint64_t uint64_t
#endif
typedef struct {
uint32_t bitfield[(PB_MAX_REQUIRED_FIELDS + 31) / 32];
} pb_fields_seen_t;
/*******************************
* 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 *
********************/
static bool checkreturn pb_decode_varint32_eof(pb_istream_t *stream, uint32_t *dest, bool *eof)
{
pb_byte_t byte;
uint32_t result;
if (!pb_readbyte(stream, &byte))
{
if (stream->bytes_left == 0)
{
if (eof)
{
*eof = true;
}
}
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 (!pb_readbyte(stream, &byte))
return false;
if (bitpos >= 32)
{
/* Note: The varint could have trailing 0x80 bytes, or 0xFF for negative. */
uint8_t sign_extension = (bitpos < 63) ? 0xFF : 0x01;
if ((byte & 0x7F) != 0x00 && ((result >> 31) == 0 || byte != sign_extension))
{
PB_RETURN_ERROR(stream, "varint overflow");
}
}
else
{
result |= (uint32_t)(byte & 0x7F) << bitpos;
}
bitpos = (uint_fast8_t)(bitpos + 7);
} while (byte & 0x80);
if (bitpos == 35 && (byte & 0x70) != 0)
{
/* The last byte was at bitpos=28, so only bottom 4 bits fit. */
PB_RETURN_ERROR(stream, "varint overflow");
}
}
*dest = result;
return true;
}
bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest)
{
return pb_decode_varint32_eof(stream, dest, NULL);
}
#ifndef PB_WITHOUT_64BIT
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;
}
#endif
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_eof(stream, &temp, eof))
{
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)
PB_RETURN_ERROR(stream, "varint overflow");
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);
case PB_WT_STRING:
/* Calling read_raw_value with a PB_WT_STRING is an error.
* Explicitly handle this case and fallthrough to default to avoid
* compiler warnings.
*/
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_basic_field(pb_istream_t *stream, pb_field_iter_t *field)
{
switch (PB_LTYPE(field->type))
{
case PB_LTYPE_VARINT:
case PB_LTYPE_UVARINT:
case PB_LTYPE_SVARINT:
return pb_dec_varint(stream, field);
case PB_LTYPE_FIXED32:
case PB_LTYPE_FIXED64:
return pb_dec_fixed(stream, field);
case PB_LTYPE_BYTES:
return pb_dec_bytes(stream, field);
case PB_LTYPE_STRING:
return pb_dec_string(stream, field);
case PB_LTYPE_SUBMESSAGE:
return pb_dec_submessage(stream, field);
case PB_LTYPE_FIXED_LENGTH_BYTES:
return pb_dec_fixed_length_bytes(stream, field);
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
}
static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field)
{
switch (PB_HTYPE(field->type))
{
case PB_HTYPE_REQUIRED:
return decode_basic_field(stream, field);
case PB_HTYPE_OPTIONAL:
if (field->pSize != NULL)
*(bool*)field->pSize = true;
return decode_basic_field(stream, field);
case PB_HTYPE_REPEATED:
if (wire_type == PB_WT_STRING
&& PB_LTYPE(field->type) <= PB_LTYPE_LAST_PACKABLE)
{
/* Packed array */
bool status = true;
pb_istream_t substream;
pb_size_t *size = (pb_size_t*)field->pSize;
field->pData = (char*)field->pField + field->data_size * (*size);
if (!pb_make_string_substream(stream, &substream))
return false;
while (substream.bytes_left > 0 && *size < field->array_size)
{
if (!decode_basic_field(&substream, field))
{
status = false;
break;
}
(*size)++;
field->pData = (char*)field->pData + field->data_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*)field->pSize;
field->pData = (char*)field->pField + field->data_size * (*size);
if ((*size)++ >= field->array_size)
PB_RETURN_ERROR(stream, "array overflow");
return decode_basic_field(stream, field);
}
case PB_HTYPE_ONEOF:
*(pb_size_t*)field->pSize = field->tag;
if (PB_LTYPE(field->type) == PB_LTYPE_SUBMESSAGE)
{
/* We memset to zero so that any callbacks are set to NULL.
* pb_dec_submessage() will set any default values. */
memset(field->pData, 0, field->data_size);
}
return decode_basic_field(stream, field);
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 *field)
{
if (PB_LTYPE(field->type) == PB_LTYPE_STRING ||
PB_LTYPE(field->type) == PB_LTYPE_BYTES)
{
*(void**)pItem = NULL;
}
else if (PB_LTYPE(field->type) == PB_LTYPE_SUBMESSAGE)
{
/* We memset to zero so that any callbacks are set to NULL.
* Then set any default values. */
pb_field_iter_t submsg_iter;
memset(pItem, 0, field->data_size);
if (pb_field_iter_begin(&submsg_iter, field->submsg_desc, pItem))
{
(void)pb_message_set_to_defaults(&submsg_iter);
}
}
}
#endif
static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field)
{
#ifndef PB_ENABLE_MALLOC
PB_UNUSED(wire_type);
PB_UNUSED(field);
PB_RETURN_ERROR(stream, "no malloc support");
#else
switch (PB_HTYPE(field->type))
{
case PB_HTYPE_REQUIRED:
case PB_HTYPE_OPTIONAL:
case PB_HTYPE_ONEOF:
if (PB_LTYPE(field->type) == PB_LTYPE_SUBMESSAGE &&
*(void**)field->pField != NULL)
{
/* Duplicate field, have to release the old allocation first. */
/* FIXME: Does this work correctly for oneofs? */
pb_release_single_field(field);
}
if (PB_HTYPE(field->type) == PB_HTYPE_ONEOF)
{
*(pb_size_t*)field->pSize = field->tag;
}
if (PB_LTYPE(field->type) == PB_LTYPE_STRING ||
PB_LTYPE(field->type) == PB_LTYPE_BYTES)
{
/* pb_dec_string and pb_dec_bytes handle allocation themselves */
field->pData = field->pField;
return decode_basic_field(stream, field);
}
else
{
if (!allocate_field(stream, field->pField, field->data_size, 1))
return false;
field->pData = *(void**)field->pField;
initialize_pointer_field(field->pData, field);
return decode_basic_field(stream, field);
}
case PB_HTYPE_REPEATED:
if (wire_type == PB_WT_STRING
&& PB_LTYPE(field->type) <= PB_LTYPE_LAST_PACKABLE)
{
/* Packed array, multiple items come in at once. */
bool status = true;
pb_size_t *size = (pb_size_t*)field->pSize;
size_t allocated_size = *size;
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) / field->data_size + 1;
if (!allocate_field(&substream, field->pField, field->data_size, allocated_size))
{
status = false;
break;
}
}
/* Decode the array entry */
field->pData = *(char**)field->pField + field->data_size * (*size);
initialize_pointer_field(field->pData, field);
if (!decode_basic_field(&substream, field))
{
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*)field->pSize;
if (*size == PB_SIZE_MAX)
PB_RETURN_ERROR(stream, "too many array entries");
(*size)++;
if (!allocate_field(stream, field->pField, field->data_size, *size))
return false;
field->pData = *(char**)field->pField + field->data_size * (*size - 1);
initialize_pointer_field(field->pData, field);
return decode_basic_field(stream, field);
}
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 *field)
{
if (!field->descriptor->field_callback)
return pb_skip_field(stream, wire_type);
if (wire_type == PB_WT_STRING)
{
pb_istream_t substream;
size_t prev_bytes_left;
if (!pb_make_string_substream(stream, &substream))
return false;
do
{
prev_bytes_left = substream.bytes_left;
if (!field->descriptor->field_callback(&substream, NULL, field))
PB_RETURN_ERROR(stream, "callback failed");
} while (substream.bytes_left > 0 && substream.bytes_left < prev_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 field->descriptor->field_callback(&substream, NULL, field);
}
}
static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field)
{
#ifdef PB_ENABLE_MALLOC
/* When decoding an oneof field, check if there is old data that must be
* released first. */
if (PB_HTYPE(field->type) == PB_HTYPE_ONEOF)
{
if (!pb_release_union_field(stream, field))
return false;
}
#endif
switch (PB_ATYPE(field->type))
{
case PB_ATYPE_STATIC:
return decode_static_field(stream, wire_type, field);
case PB_ATYPE_POINTER:
return decode_pointer_field(stream, wire_type, field);
case PB_ATYPE_CALLBACK:
return decode_callback_field(stream, wire_type, field);
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
}
/* Default handler for extension fields. Expects to have a pb_msgdesc_t
* pointer in the extension->type->arg field, pointing to a message with
* only one field in it. */
static bool checkreturn default_extension_decoder(pb_istream_t *stream,
pb_extension_t *extension, uint32_t tag, pb_wire_type_t wire_type)
{
pb_field_iter_t iter;
if (!pb_field_iter_begin_extension(&iter, extension))
PB_RETURN_ERROR(stream, "invalid extension");
if (iter.tag != tag)
return true;
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)
{
pb_size_t start = iter->index;
do {
if (PB_LTYPE(iter->type) == PB_LTYPE_EXTENSION)
return true;
(void)pb_field_iter_next(iter);
} while (iter->index != start);
return false;
}
/* Initialize message fields to default values, recursively */
static bool pb_field_set_to_default(pb_field_iter_t *field)
{
pb_type_t type;
type = field->type;
if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
{
pb_extension_t *ext = *(pb_extension_t* const *)field->pData;
while (ext != NULL)
{
pb_field_iter_t ext_iter;
if (pb_field_iter_begin_extension(&ext_iter, ext))
{
ext->found = false;
if (!pb_message_set_to_defaults(&ext_iter))
return false;
}
ext = ext->next;
}
}
else if (PB_ATYPE(type) == PB_ATYPE_STATIC)
{
bool init_data = true;
if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && field->pSize != NULL)
{
/* Set has_field to false. Still initialize the optional field
* itself also. */
*(bool*)field->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*)field->pSize = 0;
init_data = false;
}
if (init_data)
{
if (PB_LTYPE(field->type) == PB_LTYPE_SUBMESSAGE)
{
/* Initialize submessage to defaults */
pb_field_iter_t submsg_iter;
if (pb_field_iter_begin(&submsg_iter, field->submsg_desc, field->pData))
{
if (!pb_message_set_to_defaults(&submsg_iter))
return false;
}
}
else
{
/* Initialize to zeros */
memset(field->pData, 0, field->data_size);
}
}
}
else if (PB_ATYPE(type) == PB_ATYPE_POINTER)
{
/* Initialize the pointer to NULL. */
*(void**)field->pField = NULL;
/* Initialize array count to 0. */
if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
PB_HTYPE(type) == PB_HTYPE_ONEOF)
{
*(pb_size_t*)field->pSize = 0;
}
}
else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
{
/* Don't overwrite callback */
}
return true;
}
static bool pb_message_set_to_defaults(pb_field_iter_t *iter)
{
pb_istream_t defstream = PB_ISTREAM_EMPTY;
uint32_t tag = 0;
pb_wire_type_t wire_type = PB_WT_VARINT;
bool eof;
if (iter->descriptor->default_value)
{
defstream = pb_istream_from_buffer(iter->descriptor->default_value, (size_t)-1);
if (!pb_decode_tag(&defstream, &wire_type, &tag, &eof))
return false;
}
do
{
if (!pb_field_set_to_default(iter))
return false;
if (tag != 0 && iter->tag == tag)
{
/* We have a default value for this field in the defstream */
if (!decode_field(&defstream, wire_type, iter))
return false;
if (!pb_decode_tag(&defstream, &wire_type, &tag, &eof))
return false;
if (iter->pSize)
*(bool*)iter->pSize = false;
}
} while (pb_field_iter_next(iter));
return true;
}
/*********************
* Decode all fields *
*********************/
static bool checkreturn pb_decode_inner(pb_istream_t *stream, const pb_msgdesc_t *fields, void *dest_struct, unsigned int flags)
{
uint32_t extension_range_start = 0;
/* 'fixed_count_field' and 'fixed_count_size' track position of a repeated fixed
* count field. This can only handle _one_ repeated fixed count field that
* is unpacked and unordered among other (non repeated fixed count) fields.
*/
pb_size_t fixed_count_field = PB_SIZE_MAX;
pb_size_t fixed_count_size = 0;
pb_size_t fixed_count_total_size = 0;
pb_fields_seen_t fields_seen = {{0, 0}};
const uint32_t allbits = ~(uint32_t)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 (tag == 0)
{
if (flags & PB_DECODE_NULLTERMINATED)
{
break;
}
else
{
PB_RETURN_ERROR(stream, "zero tag");
}
}
if (!pb_field_iter_find(&iter, tag) || PB_LTYPE(iter.type) == PB_LTYPE_EXTENSION)
{
/* 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.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 a repeated fixed count field was found, get size from
* 'fixed_count_field' as there is no counter contained in the struct.
*/
if (PB_HTYPE(iter.type) == PB_HTYPE_REPEATED && iter.pSize == &iter.array_size)
{
if (fixed_count_field != iter.index) {
/* If the new fixed count field does not match the previous one,
* check that the previous one is NULL or that it finished
* receiving all the expected data.
*/
if (fixed_count_field != PB_SIZE_MAX &&
fixed_count_size != fixed_count_total_size)
{
PB_RETURN_ERROR(stream, "wrong size for fixed count field");