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Diffstat (limited to 'src/lib/nanopb/pb_decode.cc')
| -rw-r--r-- | src/lib/nanopb/pb_decode.cc | 1709 |
1 files changed, 1709 insertions, 0 deletions
diff --git a/src/lib/nanopb/pb_decode.cc b/src/lib/nanopb/pb_decode.cc new file mode 100644 index 0000000..b194825 --- /dev/null +++ b/src/lib/nanopb/pb_decode.cc @@ -0,0 +1,1709 @@ +/* pb_decode.c -- decode a protobuf using minimal resources + * + * 2011 Petteri Aimonen <jpa@kapsi.fi> + */ + +/* 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_wire_type_t wire_type, 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_extension_t *extension); +static bool pb_field_set_to_default(pb_field_iter_t *field); +static bool pb_message_set_to_defaults(pb_field_iter_t *iter); +static bool checkreturn pb_dec_bool(pb_istream_t *stream, const pb_field_iter_t *field); +static bool checkreturn pb_dec_varint(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 + +#define PB_WT_PACKED ((pb_wire_type_t)0xFF) + +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) +{ + if (count == 0) + return true; + +#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 msglen) +{ + 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 = msglen; +#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. */ + pb_byte_t sign_extension = (bitpos < 63) ? 0xFF : 0x01; + bool valid_extension = ((byte & 0x7F) == 0x00 || + ((result >> 31) != 0 && byte == sign_extension)); + + if (bitpos >= 64 || !valid_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; + + if ((size_t)length != length) + { + PB_RETURN_ERROR(stream, "size too large"); + } + + return pb_read(stream, NULL, (size_t)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_t)size; + stream->bytes_left -= (size_t)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_wire_type_t wire_type, pb_field_iter_t *field) +{ + switch (PB_LTYPE(field->type)) + { + case PB_LTYPE_BOOL: + if (wire_type != PB_WT_VARINT && wire_type != PB_WT_PACKED) + PB_RETURN_ERROR(stream, "wrong wire type"); + + return pb_dec_bool(stream, field); + + case PB_LTYPE_VARINT: + case PB_LTYPE_UVARINT: + case PB_LTYPE_SVARINT: + if (wire_type != PB_WT_VARINT && wire_type != PB_WT_PACKED) + PB_RETURN_ERROR(stream, "wrong wire type"); + + return pb_dec_varint(stream, field); + + case PB_LTYPE_FIXED32: + if (wire_type != PB_WT_32BIT && wire_type != PB_WT_PACKED) + PB_RETURN_ERROR(stream, "wrong wire type"); + + return pb_decode_fixed32(stream, field->pData); + + case PB_LTYPE_FIXED64: + if (wire_type != PB_WT_64BIT && wire_type != PB_WT_PACKED) + PB_RETURN_ERROR(stream, "wrong wire type"); + +#ifdef PB_CONVERT_DOUBLE_FLOAT + if (field->data_size == sizeof(float)) + { + return pb_decode_double_as_float(stream, (float*)field->pData); + } +#endif + +#ifdef PB_WITHOUT_64BIT + PB_RETURN_ERROR(stream, "invalid data_size"); +#else + return pb_decode_fixed64(stream, field->pData); +#endif + + case PB_LTYPE_BYTES: + if (wire_type != PB_WT_STRING) + PB_RETURN_ERROR(stream, "wrong wire type"); + + return pb_dec_bytes(stream, field); + + case PB_LTYPE_STRING: + if (wire_type != PB_WT_STRING) + PB_RETURN_ERROR(stream, "wrong wire type"); + + return pb_dec_string(stream, field); + + case PB_LTYPE_SUBMESSAGE: + case PB_LTYPE_SUBMSG_W_CB: + if (wire_type != PB_WT_STRING) + PB_RETURN_ERROR(stream, "wrong wire type"); + + return pb_dec_submessage(stream, field); + + case PB_LTYPE_FIXED_LENGTH_BYTES: + if (wire_type != PB_WT_STRING) + PB_RETURN_ERROR(stream, "wrong wire type"); + + 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, wire_type, field); + + case PB_HTYPE_OPTIONAL: + if (field->pSize != NULL) + *(bool*)field->pSize = true; + return decode_basic_field(stream, wire_type, 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, PB_WT_PACKED, 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, wire_type, field); + } + + case PB_HTYPE_ONEOF: + if (PB_LTYPE_IS_SUBMSG(field->type) && + *(pb_size_t*)field->pSize != field->tag) + { + /* We memset to zero so that any callbacks are set to NULL. + * This is because the callbacks might otherwise have values + * from some other union field. + * If callbacks are needed inside oneof field, use .proto + * option submsg_callback to have a separate callback function + * that can set the fields before submessage is decoded. + * pb_dec_submessage() will set any default values. */ + memset(field->pData, 0, (size_t)field->data_size); + + /* Set default values for the submessage fields. */ + if (field->submsg_desc->default_value != NULL || + field->submsg_desc->field_callback != NULL || + field->submsg_desc->submsg_info[0] != NULL) + { + 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)) + PB_RETURN_ERROR(stream, "failed to set defaults"); + } + } + } + *(pb_size_t*)field->pSize = field->tag; + + return decode_basic_field(stream, wire_type, 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"); + +#ifdef __AVR__ + /* Workaround for AVR libc bug 53284: http://savannah.nongnu.org/bugs/?53284 + * Realloc to size of 1 byte can cause corruption of the malloc structures. + */ + if (data_size == 1 && array_size == 1) + { + data_size = 2; + } +#endif + + /* 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_IS_SUBMSG(field->type)) + { + /* We memset to zero so that any callbacks are set to NULL. + * Default values will be set by pb_dec_submessage(). */ + memset(pItem, 0, field->data_size); + } +} +#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_IS_SUBMSG(field->type) && *(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, wire_type, 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, wire_type, 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 == PB_SIZE_MAX) + { +#ifndef PB_NO_ERRMSG + stream->errmsg = "too many array entries"; +#endif + status = false; + break; + } + + if ((size_t)*size + 1 > allocated_size) + { + /* Allocate more storage. This tries to guess the + * number of remaining entries. Round the division + * upwards. */ + size_t remain = (substream.bytes_left - 1) / field->data_size + 1; + if (remain < PB_SIZE_MAX - allocated_size) + allocated_size += remain; + else + allocated_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, PB_WT_PACKED, field)) + { + 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"); + + if (!allocate_field(stream, field->pField, field->data_size, (size_t)(*size + 1))) + return false; + + field->pData = *(char**)field->pField + field->data_size * (*size); + (*size)++; + initialize_pointer_field(field->pData, field); + return decode_basic_field(stream, wire_type, 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 || !iter.message) + 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_extension_t *extension) +{ + 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; +} + +/* 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_IS_SUBMSG(field->type) && + (field->submsg_desc->default_value != NULL || + field->submsg_desc->field_callback != NULL || + field->submsg_desc->submsg_info[0] != NULL)) + { + /* Initialize submessage to defaults. + * Only needed if it has default values + * or callback/submessage fields. */ + 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, (size_t)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; + pb_extension_t *extensions = NULL; + + /* '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; + + if (pb_field_iter_begin(&iter, fields, dest_struct)) + { + if ((flags & PB_DECODE_NOINIT) == 0) + { + if (!pb_message_set_to_defaults(&iter)) + PB_RETURN_ERROR(stream, "failed to set defaults"); + } + } + + 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 (extension_range_start == 0) + { + if (pb_field_iter_find_extension(&iter)) + { + extensions = *(pb_extension_t* const *)iter.pData; + extension_range_start = iter.tag; + } + + if (!extensions) + { + extension_range_start = (uint32_t)-1; + } + } + + if (tag >= extension_range_start) + { + size_t pos = stream->bytes_left; + + if (!decode_extension(stream, tag, wire_type, extensions)) + 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"); + } + + fixed_count_field = iter.index; + fixed_count_size = 0; + fixed_count_total_size = iter.array_size; + } + + iter.pSize = &fixed_count_size; + } + + if (PB_HTYPE(iter.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.bitfield[iter.required_field_index >> 5] |= tmp; + } + + if (!decode_field(stream, wire_type, &iter)) + return false; + } + + /* Check that all elements of the last decoded fixed count field were present. */ + if (fixed_count_field != PB_SIZE_MAX && + fixed_count_size != fixed_count_total_size) + { + PB_RETURN_ERROR(stream, "wrong size for fixed count field"); + } + + /* Check that all required fields were present. */ + { + pb_size_t req_field_count = iter.descriptor->required_field_count; + + if (req_field_count > 0) + { + pb_size_t i; + + if (req_field_count > PB_MAX_REQUIRED_FIELDS) + req_field_count = PB_MAX_REQUIRED_FIELDS; + + /* Check the whole words */ + for (i = 0; i < (req_field_count >> 5); i++) + { + if (fields_seen.bitfield[i] != allbits) + PB_RETURN_ERROR(stream, "missing required field"); + } + + /* Check the remaining bits (if any) */ + if ((req_field_count & 31) != 0) + { + if (fields_seen.bitfield[req_field_count >> 5] != + (allbits >> (uint_least8_t)(32 - (req_field_count & 31)))) + { + PB_RETURN_ERROR(stream, "missing required field"); + } + } + } + } + + return true; +} + +bool checkreturn pb_decode_ex(pb_istream_t *stream, const pb_msgdesc_t *fields, void *dest_struct, unsigned int flags) +{ + bool status; + + if ((flags & PB_DECODE_DELIMITED) == 0) + { + status = pb_decode_inner(stream, fields, dest_struct, flags); + } + else + { + pb_istream_t substream; + if (!pb_make_string_substream(stream, &substream)) + return false; + + status = pb_decode_inner(&substream, fields, dest_struct, flags); + + if (!pb_close_string_substream(stream, &substream)) + return false; + } + +#ifdef PB_ENABLE_MALLOC + if (!status) + pb_release(fields, dest_struct); +#endif + + return status; +} + +bool checkreturn pb_decode(pb_istream_t *stream, const pb_msgdesc_t *fields, void *dest_struct) +{ + bool status; + + status = pb_decode_inner(stream, fields, dest_struct, 0); + +#ifdef PB_ENABLE_MALLOC + if (!status) + pb_release(fields, dest_struct); +#endif + + 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 *field) +{ + pb_field_iter_t old_field = *field; + pb_size_t old_tag = *(pb_size_t*)field->pSize; /* Previous which_ value */ + pb_size_t new_tag = field->tag; /* New which_ value */ + + if (old_tag == 0) + return true; /* Ok, no old data in union */ + + if (old_tag == new_tag) + return true; /* Ok, old data is of same type => merge */ + + /* Release old data. The find can fail if the message struct contains + * invalid data. */ + if (!pb_field_iter_find(&old_field, old_tag)) + PB_RETURN_ERROR(stream, "invalid union tag"); + + pb_release_single_field(&old_field); + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { + /* Initialize the pointer to NULL to make sure it is valid + * even in case of error return. */ + *(void**)field->pField = NULL; + field->pData = NULL; + } + + return true; +} + +static void pb_release_single_field(pb_field_iter_t *field) +{ + pb_type_t type; + type = field->type; + + if (PB_HTYPE(type) == PB_HTYPE_ONEOF) + { + if (*(pb_size_t*)field->pSize != field->tag) + return; /* This is not the current field in the union */ + } + + /* Release anything contained inside an extension or submsg. + * This has to be done even if the submsg itself is statically + * allocated. */ + if (PB_LTYPE(type) == PB_LTYPE_EXTENSION) + { + /* Release fields from all extensions in the linked list */ + pb_extension_t *ext = *(pb_extension_t**)field->pData; + while (ext != NULL) + { + pb_field_iter_t ext_iter; + if (pb_field_iter_begin_extension(&ext_iter, ext)) + { + pb_release_single_field(&ext_iter); + } + ext = ext->next; + } + } + else if (PB_LTYPE_IS_SUBMSG(type) && PB_ATYPE(type) != PB_ATYPE_CALLBACK) + { + /* Release fields in submessage or submsg array */ + pb_size_t count = 1; + + if (PB_ATYPE(type) == PB_ATYPE_POINTER) + { + field->pData = *(void**)field->pField; + } + else + { + field->pData = field->pField; + } + + if (PB_HTYPE(type) == PB_HTYPE_REPEATED) + { + count = *(pb_size_t*)field->pSize; + + if (PB_ATYPE(type) == PB_ATYPE_STATIC && count > field->array_size) + { + /* Protect against corrupted _count fields */ + count = field->array_size; + } + } + + if (field->pData) + { + for (; count > 0; count--) + { + pb_release(field->submsg_desc, field->pData); + field->pData = (char*)field->pData + field->data_size; + } + } + } + + if (PB_ATYPE(type) == PB_ATYPE_POINTER) + { + if (PB_HTYPE(type) == PB_HTYPE_REPEATED && + (PB_LTYPE(type) == PB_LTYPE_STRING || + PB_LTYPE(type) == PB_LTYPE_BYTES)) + { + /* Release entries in repeated string or bytes array */ + void **pItem = *(void***)field->pField; + pb_size_t count = *(pb_size_t*)field->pSize; + for (; count > 0; count--) + { + pb_free(*pItem); + *pItem++ = NULL; + } + } + + if (PB_HTYPE(type) == PB_HTYPE_REPEATED) + { + /* We are going to release the array, so set the size to 0 */ + *(pb_size_t*)field->pSize = 0; + } + + /* Release main pointer */ + pb_free(*(void**)field->pField); + *(void**)field->pField = NULL; + } +} + +void pb_release(const pb_msgdesc_t *fields, void *dest_struct) +{ + pb_field_iter_t iter; + + if (!dest_struct) + return; /* Ignore NULL pointers, similar to free() */ + + if (!pb_field_iter_begin(&iter, fields, dest_struct)) + return; /* Empty message type */ + + do + { + pb_release_single_field(&iter); + } while (pb_field_iter_next(&iter)); +} +#endif + +/* Field decoders */ + +bool pb_decode_bool(pb_istream_t *stream, bool *dest) +{ + uint32_t value; + if (!pb_decode_varint32(stream, &value)) + return false; + + *(bool*)dest = (value != 0); + return true; +} + +bool pb_decode_svarint(pb_istream_t *stream, pb_int64_t *dest) +{ + pb_uint64_t value; + if (!pb_decode_varint(stream, &value)) + return false; + + if (value & 1) + *dest = (pb_int64_t)(~(value >> 1)); + else + *dest = (pb_int64_t)(value >> 1); + + return true; +} + +bool pb_decode_fixed32(pb_istream_t *stream, void *dest) +{ + union { + uint32_t fixed32; + pb_byte_t bytes[4]; + } u; + + if (!pb_read(stream, u.bytes, 4)) + return false; + +#if defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN && CHAR_BIT == 8 + /* fast path - if we know that we're on little endian, assign directly */ + *(uint32_t*)dest = u.fixed32; +#else + *(uint32_t*)dest = ((uint32_t)u.bytes[0] << 0) | + ((uint32_t)u.bytes[1] << 8) | + ((uint32_t)u.bytes[2] << 16) | + ((uint32_t)u.bytes[3] << 24); +#endif + return true; +} + +#ifndef PB_WITHOUT_64BIT +bool pb_decode_fixed64(pb_istream_t *stream, void *dest) +{ + union { + uint64_t fixed64; + pb_byte_t bytes[8]; + } u; + + if (!pb_read(stream, u.bytes, 8)) + return false; + +#if defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN && CHAR_BIT == 8 + /* fast path - if we know that we're on little endian, assign directly */ + *(uint64_t*)dest = u.fixed64; +#else + *(uint64_t*)dest = ((uint64_t)u.bytes[0] << 0) | + ((uint64_t)u.bytes[1] << 8) | + ((uint64_t)u.bytes[2] << 16) | + ((uint64_t)u.bytes[3] << 24) | + ((uint64_t)u.bytes[4] << 32) | + ((uint64_t)u.bytes[5] << 40) | + ((uint64_t)u.bytes[6] << 48) | + ((uint64_t)u.bytes[7] << 56); +#endif + return true; +} +#endif + +static bool checkreturn pb_dec_bool(pb_istream_t *stream, const pb_field_iter_t *field) +{ + return pb_decode_bool(stream, (bool*)field->pData); +} + +static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_iter_t *field) +{ + if (PB_LTYPE(field->type) == PB_LTYPE_UVARINT) + { + pb_uint64_t value, clamped; + if (!pb_decode_varint(stream, &value)) + return false; + + /* Cast to the proper field size, while checking for overflows */ + if (field->data_size == sizeof(pb_uint64_t)) + clamped = *(pb_uint64_t*)field->pData = value; + else if (field->data_size == sizeof(uint32_t)) + clamped = *(uint32_t*)field->pData = (uint32_t)value; + else if (field->data_size == sizeof(uint_least16_t)) + clamped = *(uint_least16_t*)field->pData = (uint_least16_t)value; + else if (field->data_size == sizeof(uint_least8_t)) + clamped = *(uint_least8_t*)field->pData = (uint_least8_t)value; + else + PB_RETURN_ERROR(stream, "invalid data_size"); + + if (clamped != value) + PB_RETURN_ERROR(stream, "integer too large"); + + return true; + } + else + { + pb_uint64_t value; + pb_int64_t svalue; + pb_int64_t clamped; + + if (PB_LTYPE(field->type) == PB_LTYPE_SVARINT) + { + if (!pb_decode_svarint(stream, &svalue)) + return false; + } + else + { + if (!pb_decode_varint(stream, &value)) + return false; + + /* See issue 97: Google's C++ protobuf allows negative varint values to + * be cast as int32_t, instead of the int64_t that should be used when + * encoding. Nanopb versions before 0.2.5 had a bug in encoding. In order to + * not break decoding of such messages, we cast <=32 bit fields to + * int32_t first to get the sign correct. + */ + if (field->data_size == sizeof(pb_int64_t)) + svalue = (pb_int64_t)value; + else + svalue = (int32_t)value; + } + + /* Cast to the proper field size, while checking for overflows */ + if (field->data_size == sizeof(pb_int64_t)) + clamped = *(pb_int64_t*)field->pData = svalue; + else if (field->data_size == sizeof(int32_t)) + clamped = *(int32_t*)field->pData = (int32_t)svalue; + else if (field->data_size == sizeof(int_least16_t)) + clamped = *(int_least16_t*)field->pData = (int_least16_t)svalue; + else if (field->data_size == sizeof(int_least8_t)) + clamped = *(int_least8_t*)field->pData = (int_least8_t)svalue; + else + PB_RETURN_ERROR(stream, "invalid data_size"); + + if (clamped != svalue) + PB_RETURN_ERROR(stream, "integer too large"); + + return true; + } +} + +static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_iter_t *field) +{ + uint32_t size; + size_t alloc_size; + pb_bytes_array_t *dest; + + if (!pb_decode_varint32(stream, &size)) + return false; + + if (size > PB_SIZE_MAX) + PB_RETURN_ERROR(stream, "bytes overflow"); + + alloc_size = PB_BYTES_ARRAY_T_ALLOCSIZE(size); + if (size > alloc_size) + PB_RETURN_ERROR(stream, "size too large"); + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { +#ifndef PB_ENABLE_MALLOC + PB_RETURN_ERROR(stream, "no malloc support"); +#else + if (stream->bytes_left < size) + PB_RETURN_ERROR(stream, "end-of-stream"); + + if (!allocate_field(stream, field->pData, alloc_size, 1)) + return false; + dest = *(pb_bytes_array_t**)field->pData; +#endif + } + else + { + if (alloc_size > field->data_size) + PB_RETURN_ERROR(stream, "bytes overflow"); + dest = (pb_bytes_array_t*)field->pData; + } + + dest->size = (pb_size_t)size; + return pb_read(stream, dest->bytes, (size_t)size); +} + +static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_iter_t *field) +{ + uint32_t size; + size_t alloc_size; + pb_byte_t *dest = (pb_byte_t*)field->pData; + + if (!pb_decode_varint32(stream, &size)) + return false; + + if (size == (uint32_t)-1) + PB_RETURN_ERROR(stream, "size too large"); + + /* Space for null terminator */ + alloc_size = (size_t)(size + 1); + + if (alloc_size < size) + PB_RETURN_ERROR(stream, "size too large"); + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { +#ifndef PB_ENABLE_MALLOC + PB_RETURN_ERROR(stream, "no malloc support"); +#else + if (stream->bytes_left < size) + PB_RETURN_ERROR(stream, "end-of-stream"); + + if (!allocate_field(stream, field->pData, alloc_size, 1)) + return false; + dest = *(pb_byte_t**)field->pData; +#endif + } + else + { + if (alloc_size > field->data_size) + PB_RETURN_ERROR(stream, "string overflow"); + } + + dest[size] = 0; + + if (!pb_read(stream, dest, (size_t)size)) + return false; + +#ifdef PB_VALIDATE_UTF8 + if (!pb_validate_utf8((const char*)dest)) + PB_RETURN_ERROR(stream, "invalid utf8"); +#endif + + return true; +} + +static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_iter_t *field) +{ + bool status = true; + bool submsg_consumed = false; + pb_istream_t substream; + + if (!pb_make_string_substream(stream, &substream)) + return false; + + if (field->submsg_desc == NULL) + PB_RETURN_ERROR(stream, "invalid field descriptor"); + + /* Submessages can have a separate message-level callback that is called + * before decoding the message. Typically it is used to set callback fields + * inside oneofs. */ + if (PB_LTYPE(field->type) == PB_LTYPE_SUBMSG_W_CB && field->pSize != NULL) + { + /* Message callback is stored right before pSize. */ + pb_callback_t *callback = (pb_callback_t*)field->pSize - 1; + if (callback->funcs.decode) + { + status = callback->funcs.decode(&substream, field, &callback->arg); + + if (substream.bytes_left == 0) + { + submsg_consumed = true; + } + } + } + + /* Now decode the submessage contents */ + if (status && !submsg_consumed) + { + unsigned int flags = 0; + + /* Static required/optional fields are already initialized by top-level + * pb_decode(), no need to initialize them again. */ + if (PB_ATYPE(field->type) == PB_ATYPE_STATIC && + PB_HTYPE(field->type) != PB_HTYPE_REPEATED) + { + flags = PB_DECODE_NOINIT; + } + + status = pb_decode_inner(&substream, field->submsg_desc, field->pData, flags); + } + + if (!pb_close_string_substream(stream, &substream)) + return false; + + return status; +} + +static bool checkreturn pb_dec_fixed_length_bytes(pb_istream_t *stream, const pb_field_iter_t *field) +{ + uint32_t size; + + if (!pb_decode_varint32(stream, &size)) + return false; + + if (size > PB_SIZE_MAX) + PB_RETURN_ERROR(stream, "bytes overflow"); + + if (size == 0) + { + /* As a special case, treat empty bytes string as all zeros for fixed_length_bytes. */ + memset(field->pData, 0, (size_t)field->data_size); + return true; + } + + if (size != field->data_size) + PB_RETURN_ERROR(stream, "incorrect fixed length bytes size"); + + return pb_read(stream, (pb_byte_t*)field->pData, (size_t)field->data_size); +} + +#ifdef PB_CONVERT_DOUBLE_FLOAT +bool pb_decode_double_as_float(pb_istream_t *stream, float *dest) +{ + uint_least8_t sign; + int exponent; + uint32_t mantissa; + uint64_t value; + union { float f; uint32_t i; } out; + + if (!pb_decode_fixed64(stream, &value)) + return false; + + /* Decompose input value */ + sign = (uint_least8_t)((value >> 63) & 1); + exponent = (int)((value >> 52) & 0x7FF) - 1023; + mantissa = (value >> 28) & 0xFFFFFF; /* Highest 24 bits */ + + /* Figure if value is in range representable by floats. */ + if (exponent == 1024) + { + /* Special value */ + exponent = 128; + mantissa >>= 1; + } + else + { + if (exponent > 127) + { + /* Too large, convert to infinity */ + exponent = 128; + mantissa = 0; + } + else if (exponent < -150) + { + /* Too small, convert to zero */ + exponent = -127; + mantissa = 0; + } + else if (exponent < -126) + { + /* Denormalized */ + mantissa |= 0x1000000; + mantissa >>= (-126 - exponent); + exponent = -127; + } + + /* Round off mantissa */ + mantissa = (mantissa + 1) >> 1; + + /* Check if mantissa went over 2.0 */ + if (mantissa & 0x800000) + { + exponent += 1; + mantissa &= 0x7FFFFF; + mantissa >>= 1; + } + } + + /* Combine fields */ + out.i = mantissa; + out.i |= (uint32_t)(exponent + 127) << 23; + out.i |= (uint32_t)sign << 31; + + *dest = out.f; + return true; +} +#endif |