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trezor-firmware/embed/bootloader/nanopb/pb_encode.c
Jan Pochyla 55bd4a0806 rename /micropython to /embed
2017-07-28 16:23:45 +02:00

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/* pb_encode.c -- encode a protobuf using minimal resources
*
* 2011 Petteri Aimonen <jpa@kapsi.fi>
*/
#include "pb.h"
#include "pb_encode.h"
#include "pb_common.h"
/* 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
/**************************************
* Declarations internal to this file *
**************************************/
typedef bool (*pb_encoder_t)(pb_ostream_t *stream, const pb_field_t *field, const void *src) checkreturn;
static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count);
static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field, const void *pData, size_t count, pb_encoder_t func);
static bool checkreturn encode_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData);
static bool checkreturn default_extension_encoder(pb_ostream_t *stream, const pb_extension_t *extension);
static bool checkreturn encode_extension_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData);
static void *pb_const_cast(const void *p);
static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src);
static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
/* --- Function pointers to field encoders ---
* Order in the array must match pb_action_t LTYPE numbering.
*/
static const pb_encoder_t PB_ENCODERS[PB_LTYPES_COUNT] = {
&pb_enc_varint,
&pb_enc_uvarint,
&pb_enc_svarint,
&pb_enc_fixed32,
&pb_enc_fixed64,
&pb_enc_bytes,
&pb_enc_string,
&pb_enc_submessage,
NULL, /* extensions */
&pb_enc_fixed_length_bytes
};
/*******************************
* pb_ostream_t implementation *
*******************************/
static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
{
size_t i;
pb_byte_t *dest = (pb_byte_t*)stream->state;
stream->state = dest + count;
for (i = 0; i < count; i++)
dest[i] = buf[i];
return true;
}
pb_ostream_t pb_ostream_from_buffer(pb_byte_t *buf, size_t bufsize)
{
pb_ostream_t stream;
#ifdef PB_BUFFER_ONLY
stream.callback = (void*)1; /* Just a marker value */
#else
stream.callback = &buf_write;
#endif
stream.state = buf;
stream.max_size = bufsize;
stream.bytes_written = 0;
#ifndef PB_NO_ERRMSG
stream.errmsg = NULL;
#endif
return stream;
}
bool checkreturn pb_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
{
if (stream->callback != NULL)
{
if (stream->bytes_written + count > stream->max_size)
PB_RETURN_ERROR(stream, "stream full");
#ifdef PB_BUFFER_ONLY
if (!buf_write(stream, buf, count))
PB_RETURN_ERROR(stream, "io error");
#else
if (!stream->callback(stream, buf, count))
PB_RETURN_ERROR(stream, "io error");
#endif
}
stream->bytes_written += count;
return true;
}
/*************************
* Encode a single field *
*************************/
/* Encode a static array. Handles the size calculations and possible packing. */
static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field,
const void *pData, size_t count, pb_encoder_t func)
{
size_t i;
const void *p;
size_t size;
if (count == 0)
return true;
if (PB_ATYPE(field->type) != PB_ATYPE_POINTER && count > field->array_size)
PB_RETURN_ERROR(stream, "array max size exceeded");
/* We always pack arrays if the datatype allows it. */
if (PB_LTYPE(field->type) <= PB_LTYPE_LAST_PACKABLE)
{
if (!pb_encode_tag(stream, PB_WT_STRING, field->tag))
return false;
/* Determine the total size of packed array. */
if (PB_LTYPE(field->type) == PB_LTYPE_FIXED32)
{
size = 4 * count;
}
else if (PB_LTYPE(field->type) == PB_LTYPE_FIXED64)
{
size = 8 * count;
}
else
{
pb_ostream_t sizestream = PB_OSTREAM_SIZING;
p = pData;
for (i = 0; i < count; i++)
{
if (!func(&sizestream, field, p))
return false;
p = (const char*)p + field->data_size;
}
size = sizestream.bytes_written;
}
if (!pb_encode_varint(stream, (uint64_t)size))
return false;
if (stream->callback == NULL)
return pb_write(stream, NULL, size); /* Just sizing.. */
/* Write the data */
p = pData;
for (i = 0; i < count; i++)
{
if (!func(stream, field, p))
return false;
p = (const char*)p + field->data_size;
}
}
else
{
p = pData;
for (i = 0; i < count; i++)
{
if (!pb_encode_tag_for_field(stream, field))
return false;
/* Normally the data is stored directly in the array entries, but
* for pointer-type string and bytes fields, the array entries are
* actually pointers themselves also. So we have to dereference once
* more to get to the actual data. */
if (PB_ATYPE(field->type) == PB_ATYPE_POINTER &&
(PB_LTYPE(field->type) == PB_LTYPE_STRING ||
PB_LTYPE(field->type) == PB_LTYPE_BYTES))
{
if (!func(stream, field, *(const void* const*)p))
return false;
}
else
{
if (!func(stream, field, p))
return false;
}
p = (const char*)p + field->data_size;
}
}
return true;
}
/* In proto3, all fields are optional and are only encoded if their value is "non-zero".
* This function implements the check for the zero value. */
static bool pb_check_proto3_default_value(const pb_field_t *field, const void *pData)
{
if (PB_ATYPE(field->type) == PB_ATYPE_STATIC)
{
if (PB_LTYPE(field->type) == PB_LTYPE_BYTES)
{
const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData;
return bytes->size == 0;
}
else if (PB_LTYPE(field->type) == PB_LTYPE_STRING)
{
return *(const char*)pData == '\0';
}
else if (PB_LTYPE(field->type) == PB_LTYPE_FIXED_LENGTH_BYTES)
{
/* Fixed length bytes is only empty if its length is fixed
* as 0. Which would be pretty strange, but we can check
* it anyway. */
return field->data_size == 0;
}
else if (PB_LTYPE(field->type) == PB_LTYPE_SUBMESSAGE)
{
/* Check all fields in the submessage to find if any of them
* are non-zero. The comparison cannot be done byte-per-byte
* because the C struct may contain padding bytes that must
* be skipped.
*/
pb_field_iter_t iter;
if (pb_field_iter_begin(&iter, (const pb_field_t*)field->ptr, pb_const_cast(pData)))
{
do
{
if (!pb_check_proto3_default_value(iter.pos, iter.pData))
{
return false;
}
} while (pb_field_iter_next(&iter));
}
return true;
}
}
{
/* Catch-all branch that does byte-per-byte comparison for zero value.
*
* This is for all pointer fields, and for static PB_LTYPE_VARINT,
* UVARINT, SVARINT, FIXED32, FIXED64, EXTENSION fields, and also
* callback fields. These all have integer or pointer value which
* can be compared with 0.
*/
pb_size_t i;
const char *p = (const char*)pData;
for (i = 0; i < field->data_size; i++)
{
if (p[i] != 0)
{
return false;
}
}
return true;
}
}
/* Encode a field with static or pointer allocation, i.e. one whose data
* is available to the encoder directly. */
static bool checkreturn encode_basic_field(pb_ostream_t *stream,
const pb_field_t *field, const void *pData)
{
pb_encoder_t func;
bool implicit_has;
const void *pSize = &implicit_has;
func = PB_ENCODERS[PB_LTYPE(field->type)];
if (field->size_offset)
{
/* Static optional, repeated or oneof field */
pSize = (const char*)pData + field->size_offset;
}
else if (PB_HTYPE(field->type) == PB_HTYPE_OPTIONAL)
{
/* Proto3 style field, optional but without explicit has_ field. */
implicit_has = !pb_check_proto3_default_value(field, pData);
}
else
{
/* Required field, always present */
implicit_has = true;
}
if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
{
/* pData is a pointer to the field, which contains pointer to
* the data. If the 2nd pointer is NULL, it is interpreted as if
* the has_field was false.
*/
pData = *(const void* const*)pData;
implicit_has = (pData != NULL);
}
switch (PB_HTYPE(field->type))
{
case PB_HTYPE_REQUIRED:
if (!pData)
PB_RETURN_ERROR(stream, "missing required field");
if (!pb_encode_tag_for_field(stream, field))
return false;
if (!func(stream, field, pData))
return false;
break;
case PB_HTYPE_OPTIONAL:
if (*(const bool*)pSize)
{
if (!pb_encode_tag_for_field(stream, field))
return false;
if (!func(stream, field, pData))
return false;
}
break;
case PB_HTYPE_REPEATED:
if (!encode_array(stream, field, pData, *(const pb_size_t*)pSize, func))
return false;
break;
case PB_HTYPE_ONEOF:
if (*(const pb_size_t*)pSize == field->tag)
{
if (!pb_encode_tag_for_field(stream, field))
return false;
if (!func(stream, field, pData))
return false;
}
break;
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
return true;
}
/* Encode a field with callback semantics. This means that a user function is
* called to provide and encode the actual data. */
static bool checkreturn encode_callback_field(pb_ostream_t *stream,
const pb_field_t *field, const void *pData)
{
const pb_callback_t *callback = (const pb_callback_t*)pData;
#ifdef PB_OLD_CALLBACK_STYLE
const void *arg = callback->arg;
#else
void * const *arg = &(callback->arg);
#endif
if (callback->funcs.encode != NULL)
{
if (!callback->funcs.encode(stream, field, arg))
PB_RETURN_ERROR(stream, "callback error");
}
return true;
}
/* Encode a single field of any callback or static type. */
static bool checkreturn encode_field(pb_ostream_t *stream,
const pb_field_t *field, const void *pData)
{
switch (PB_ATYPE(field->type))
{
case PB_ATYPE_STATIC:
case PB_ATYPE_POINTER:
return encode_basic_field(stream, field, pData);
case PB_ATYPE_CALLBACK:
return encode_callback_field(stream, field, pData);
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
}
/* Default handler for extension fields. Expects to have a pb_field_t
* pointer in the extension->type->arg field. */
static bool checkreturn default_extension_encoder(pb_ostream_t *stream,
const pb_extension_t *extension)
{
const pb_field_t *field = (const pb_field_t*)extension->type->arg;
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. */
return encode_field(stream, field, &extension->dest);
}
else
{
return encode_field(stream, field, extension->dest);
}
}
/* Walk through all the registered extensions and give them a chance
* to encode themselves. */
static bool checkreturn encode_extension_field(pb_ostream_t *stream,
const pb_field_t *field, const void *pData)
{
const pb_extension_t *extension = *(const pb_extension_t* const *)pData;
PB_UNUSED(field);
while (extension)
{
bool status;
if (extension->type->encode)
status = extension->type->encode(stream, extension);
else
status = default_extension_encoder(stream, extension);
if (!status)
return false;
extension = extension->next;
}
return true;
}
/*********************
* Encode all fields *
*********************/
static void *pb_const_cast(const void *p)
{
/* Note: this casts away const, in order to use the common field iterator
* logic for both encoding and decoding. */
union {
void *p1;
const void *p2;
} t;
t.p2 = p;
return t.p1;
}
bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
{
pb_field_iter_t iter;
if (!pb_field_iter_begin(&iter, fields, pb_const_cast(src_struct)))
return true; /* Empty message type */
do {
if (PB_LTYPE(iter.pos->type) == PB_LTYPE_EXTENSION)
{
/* Special case for the extension field placeholder */
if (!encode_extension_field(stream, iter.pos, iter.pData))
return false;
}
else
{
/* Regular field */
if (!encode_field(stream, iter.pos, iter.pData))
return false;
}
} while (pb_field_iter_next(&iter));
return true;
}
bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
{
return pb_encode_submessage(stream, fields, src_struct);
}
bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct)
{
pb_ostream_t stream = PB_OSTREAM_SIZING;
if (!pb_encode(&stream, fields, src_struct))
return false;
*size = stream.bytes_written;
return true;
}
/********************
* Helper functions *
********************/
bool checkreturn pb_encode_varint(pb_ostream_t *stream, uint64_t value)
{
pb_byte_t buffer[10];
size_t i = 0;
if (value <= 0x7F)
{
pb_byte_t v = (pb_byte_t)value;
return pb_write(stream, &v, 1);
}
while (value)
{
buffer[i] = (pb_byte_t)((value & 0x7F) | 0x80);
value >>= 7;
i++;
}
buffer[i-1] &= 0x7F; /* Unset top bit on last byte */
return pb_write(stream, buffer, i);
}
bool checkreturn pb_encode_svarint(pb_ostream_t *stream, int64_t value)
{
uint64_t zigzagged;
if (value < 0)
zigzagged = ~((uint64_t)value << 1);
else
zigzagged = (uint64_t)value << 1;
return pb_encode_varint(stream, zigzagged);
}
bool checkreturn pb_encode_fixed32(pb_ostream_t *stream, const void *value)
{
uint32_t val = *(const uint32_t*)value;
pb_byte_t bytes[4];
bytes[0] = (pb_byte_t)(val & 0xFF);
bytes[1] = (pb_byte_t)((val >> 8) & 0xFF);
bytes[2] = (pb_byte_t)((val >> 16) & 0xFF);
bytes[3] = (pb_byte_t)((val >> 24) & 0xFF);
return pb_write(stream, bytes, 4);
}
bool checkreturn pb_encode_fixed64(pb_ostream_t *stream, const void *value)
{
uint64_t val = *(const uint64_t*)value;
pb_byte_t bytes[8];
bytes[0] = (pb_byte_t)(val & 0xFF);
bytes[1] = (pb_byte_t)((val >> 8) & 0xFF);
bytes[2] = (pb_byte_t)((val >> 16) & 0xFF);
bytes[3] = (pb_byte_t)((val >> 24) & 0xFF);
bytes[4] = (pb_byte_t)((val >> 32) & 0xFF);
bytes[5] = (pb_byte_t)((val >> 40) & 0xFF);
bytes[6] = (pb_byte_t)((val >> 48) & 0xFF);
bytes[7] = (pb_byte_t)((val >> 56) & 0xFF);
return pb_write(stream, bytes, 8);
}
bool checkreturn pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number)
{
uint64_t tag = ((uint64_t)field_number << 3) | wiretype;
return pb_encode_varint(stream, tag);
}
bool checkreturn pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t *field)
{
pb_wire_type_t wiretype;
switch (PB_LTYPE(field->type))
{
case PB_LTYPE_VARINT:
case PB_LTYPE_UVARINT:
case PB_LTYPE_SVARINT:
wiretype = PB_WT_VARINT;
break;
case PB_LTYPE_FIXED32:
wiretype = PB_WT_32BIT;
break;
case PB_LTYPE_FIXED64:
wiretype = PB_WT_64BIT;
break;
case PB_LTYPE_BYTES:
case PB_LTYPE_STRING:
case PB_LTYPE_SUBMESSAGE:
case PB_LTYPE_FIXED_LENGTH_BYTES:
wiretype = PB_WT_STRING;
break;
default:
PB_RETURN_ERROR(stream, "invalid field type");
}
return pb_encode_tag(stream, wiretype, field->tag);
}
bool checkreturn pb_encode_string(pb_ostream_t *stream, const pb_byte_t *buffer, size_t size)
{
if (!pb_encode_varint(stream, (uint64_t)size))
return false;
return pb_write(stream, buffer, size);
}
bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct)
{
/* First calculate the message size using a non-writing substream. */
pb_ostream_t substream = PB_OSTREAM_SIZING;
size_t size;
bool status;
if (!pb_encode(&substream, fields, src_struct))
{
#ifndef PB_NO_ERRMSG
stream->errmsg = substream.errmsg;
#endif
return false;
}
size = substream.bytes_written;
if (!pb_encode_varint(stream, (uint64_t)size))
return false;
if (stream->callback == NULL)
return pb_write(stream, NULL, size); /* Just sizing */
if (stream->bytes_written + size > stream->max_size)
PB_RETURN_ERROR(stream, "stream full");
/* Use a substream to verify that a callback doesn't write more than
* what it did the first time. */
substream.callback = stream->callback;
substream.state = stream->state;
substream.max_size = size;
substream.bytes_written = 0;
#ifndef PB_NO_ERRMSG
substream.errmsg = NULL;
#endif
status = pb_encode(&substream, fields, src_struct);
stream->bytes_written += substream.bytes_written;
stream->state = substream.state;
#ifndef PB_NO_ERRMSG
stream->errmsg = substream.errmsg;
#endif
if (substream.bytes_written != size)
PB_RETURN_ERROR(stream, "submsg size changed");
return status;
}
/* Field encoders */
static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
int64_t value = 0;
if (field->data_size == sizeof(int_least8_t))
value = *(const int_least8_t*)src;
else if (field->data_size == sizeof(int_least16_t))
value = *(const int_least16_t*)src;
else if (field->data_size == sizeof(int32_t))
value = *(const int32_t*)src;
else if (field->data_size == sizeof(int64_t))
value = *(const int64_t*)src;
else
PB_RETURN_ERROR(stream, "invalid data_size");
return pb_encode_varint(stream, (uint64_t)value);
}
static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
uint64_t value = 0;
if (field->data_size == sizeof(uint_least8_t))
value = *(const uint_least8_t*)src;
else if (field->data_size == sizeof(uint_least16_t))
value = *(const uint_least16_t*)src;
else if (field->data_size == sizeof(uint32_t))
value = *(const uint32_t*)src;
else if (field->data_size == sizeof(uint64_t))
value = *(const uint64_t*)src;
else
PB_RETURN_ERROR(stream, "invalid data_size");
return pb_encode_varint(stream, value);
}
static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
int64_t value = 0;
if (field->data_size == sizeof(int_least8_t))
value = *(const int_least8_t*)src;
else if (field->data_size == sizeof(int_least16_t))
value = *(const int_least16_t*)src;
else if (field->data_size == sizeof(int32_t))
value = *(const int32_t*)src;
else if (field->data_size == sizeof(int64_t))
value = *(const int64_t*)src;
else
PB_RETURN_ERROR(stream, "invalid data_size");
return pb_encode_svarint(stream, value);
}
static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
PB_UNUSED(field);
return pb_encode_fixed64(stream, src);
}
static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
PB_UNUSED(field);
return pb_encode_fixed32(stream, src);
}
static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
const pb_bytes_array_t *bytes = NULL;
bytes = (const pb_bytes_array_t*)src;
if (src == NULL)
{
/* Treat null pointer as an empty bytes field */
return pb_encode_string(stream, NULL, 0);
}
if (PB_ATYPE(field->type) == PB_ATYPE_STATIC &&
PB_BYTES_ARRAY_T_ALLOCSIZE(bytes->size) > field->data_size)
{
PB_RETURN_ERROR(stream, "bytes size exceeded");
}
return pb_encode_string(stream, bytes->bytes, bytes->size);
}
static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
size_t size = 0;
size_t max_size = field->data_size;
const char *p = (const char*)src;
if (PB_ATYPE(field->type) == PB_ATYPE_POINTER)
max_size = (size_t)-1;
if (src == NULL)
{
size = 0; /* Treat null pointer as an empty string */
}
else
{
/* strnlen() is not always available, so just use a loop */
while (size < max_size && *p != '\0')
{
size++;
p++;
}
}
return pb_encode_string(stream, (const pb_byte_t*)src, size);
}
static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
if (field->ptr == NULL)
PB_RETURN_ERROR(stream, "invalid field descriptor");
return pb_encode_submessage(stream, (const pb_field_t*)field->ptr, src);
}
static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src)
{
return pb_encode_string(stream, (const pb_byte_t*)src, field->data_size);
}
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