diff options
Diffstat (limited to 'pb_decode.c')
| -rw-r--r-- | pb_decode.c | 1178 |
1 files changed, 1178 insertions, 0 deletions
diff --git a/pb_decode.c b/pb_decode.c new file mode 100644 index 0000000..9a48c60 --- /dev/null +++ b/pb_decode.c @@ -0,0 +1,1178 @@ +/* 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" + +/************************************** + * Declarations internal to this file * + **************************************/ + +/* Iterator for pb_field_t list */ +typedef struct { + const pb_field_t *start; /* Start of the pb_field_t array */ + const pb_field_t *pos; /* Current position of the iterator */ + unsigned field_index; /* Zero-based index of the field. */ + unsigned required_field_index; /* Zero-based index that counts only the required fields */ + void *dest_struct; /* Pointer to the destination structure to decode to */ + void *pData; /* Pointer where to store current field value */ + void *pSize; /* Pointer where to store the size of current array field */ +} pb_field_iterator_t; + +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, uint8_t *buf, size_t count); +static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest); +static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, uint8_t *buf, size_t *size); +static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct); +static bool pb_field_next(pb_field_iterator_t *iter); +static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag); +static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter); +static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter); +static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_t *iter); +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_iterator_t *iter); +static bool checkreturn find_extension_field(pb_field_iterator_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_skip_varint(pb_istream_t *stream); +static bool checkreturn pb_skip_string(pb_istream_t *stream); + +/* --- 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_istream_t implementation * + *******************************/ + +static bool checkreturn buf_read(pb_istream_t *stream, uint8_t *buf, size_t count) +{ + uint8_t *source = (uint8_t*)stream->state; + stream->state = source + count; + + if (buf != NULL) + { + while (count--) + *buf++ = *source++; + } + + return true; +} + +bool checkreturn pb_read(pb_istream_t *stream, uint8_t *buf, size_t count) +{ +#ifndef PB_BUFFER_ONLY + if (buf == NULL && stream->callback != buf_read) + { + /* Skip input bytes */ + uint8_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, uint8_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 = *(uint8_t*)stream->state; + stream->state = (uint8_t*)stream->state + 1; +#endif + + stream->bytes_left--; + + return true; +} + +pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize) +{ + pb_istream_t stream; +#ifdef PB_BUFFER_ONLY + stream.callback = NULL; +#else + stream.callback = &buf_read; +#endif + stream.state = buf; + stream.bytes_left = bufsize; +#ifndef PB_NO_ERRMSG + stream.errmsg = NULL; +#endif + return stream; +} + +/******************** + * Helper functions * + ********************/ + +static bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest) +{ + uint8_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 */ + uint8_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 = (uint8_t)(bitpos + 7); + } while (byte & 0x80); + } + + *dest = result; + return true; +} + +bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest) +{ + uint8_t byte; + uint8_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 = (uint8_t)(bitpos + 7); + } while (byte & 0x80); + + *dest = result; + return true; +} + +bool checkreturn pb_skip_varint(pb_istream_t *stream) +{ + uint8_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, uint8_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; +} + +void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream) +{ + stream->state = substream->state; + +#ifndef PB_NO_ERRMSG + stream->errmsg = substream->errmsg; +#endif +} + +static void pb_field_init(pb_field_iterator_t *iter, const pb_field_t *fields, void *dest_struct) +{ + iter->start = iter->pos = fields; + iter->field_index = 0; + iter->required_field_index = 0; + iter->pData = (char*)dest_struct + iter->pos->data_offset; + iter->pSize = (char*)iter->pData + iter->pos->size_offset; + iter->dest_struct = dest_struct; +} + +static bool pb_field_next(pb_field_iterator_t *iter) +{ + bool notwrapped = true; + size_t prev_size = iter->pos->data_size; + + if (PB_ATYPE(iter->pos->type) == PB_ATYPE_STATIC && + PB_HTYPE(iter->pos->type) == PB_HTYPE_REPEATED) + { + prev_size *= iter->pos->array_size; + } + else if (PB_ATYPE(iter->pos->type) == PB_ATYPE_POINTER) + { + prev_size = sizeof(void*); + } + + if (iter->pos->tag == 0) + return false; /* Only happens with empty message types */ + + if (PB_HTYPE(iter->pos->type) == PB_HTYPE_REQUIRED) + iter->required_field_index++; + + iter->pos++; + iter->field_index++; + if (iter->pos->tag == 0) + { + iter->pos = iter->start; + iter->field_index = 0; + iter->required_field_index = 0; + iter->pData = iter->dest_struct; + prev_size = 0; + notwrapped = false; + } + + iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset; + iter->pSize = (char*)iter->pData + iter->pos->size_offset; + return notwrapped; +} + +static bool checkreturn pb_field_find(pb_field_iterator_t *iter, uint32_t tag) +{ + unsigned start = iter->field_index; + + do { + if (iter->pos->tag == tag && + PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION) + { + return true; + } + (void)pb_field_next(iter); + } while (iter->field_index != start); + + return false; +} + +/************************* + * Decode a single field * + *************************/ + +static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iterator_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: + *(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; + size_t *size = (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 = (uint8_t*)iter->pData + iter->pos->data_size * (*size); + if (!func(&substream, iter->pos, pItem)) + { + status = false; + break; + } + (*size)++; + } + pb_close_string_substream(stream, &substream); + + if (substream.bytes_left != 0) + PB_RETURN_ERROR(stream, "array overflow"); + + return status; + } + else + { + /* Repeated field */ + size_t *size = (size_t*)iter->pSize; + void *pItem = (uint8_t*)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); + } + + 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. */ +static bool checkreturn allocate_field(pb_istream_t *stream, void *pData, size_t data_size, size_t array_size) +{ + void *ptr = *(void**)pData; + size_t size = array_size * data_size; + + /* 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, 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_iterator_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_iterator_t *iter) +{ +#ifndef PB_ENABLE_MALLOC + UNUSED(wire_type); + 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: + 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; + size_t *size = (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 + 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 = *(uint8_t**)iter->pData + iter->pos->data_size * (*size); + initialize_pointer_field(pItem, iter); + if (!func(&substream, iter->pos, pItem)) + { + status = false; + break; + } + (*size)++; + } + pb_close_string_substream(stream, &substream); + + return status; + } + else + { + /* Normal repeated field, i.e. only one item at a time. */ + size_t *size = (size_t*)iter->pSize; + void *pItem; + + (*size)++; + if (!allocate_field(stream, iter->pData, iter->pos->data_size, *size)) + return false; + + pItem = *(uint8_t**)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_iterator_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); + + pb_close_string_substream(stream, &substream); + 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; + uint8_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_iterator_t *iter) +{ + 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"); + } +} + +/* 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_iterator_t iter; + + if (field->tag != tag) + return true; + + iter.start = field; + iter.pos = field; + iter.field_index = 0; + iter.required_field_index = 0; + iter.dest_struct = extension->dest; + iter.pData = extension->dest; + iter.pSize = &extension->found; + + 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_iterator_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_iterator_t *iter) +{ + unsigned start = iter->field_index; + + do { + if (PB_LTYPE(iter->pos->type) == PB_LTYPE_EXTENSION) + return true; + (void)pb_field_next(iter); + } while (iter->field_index != start); + + return false; +} + +/* Initialize message fields to default values, recursively */ +static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_struct) +{ + pb_field_iterator_t iter; + pb_field_init(&iter, fields, dest_struct); + + do + { + pb_type_t type; + type = iter.pos->type; + + /* Avoid crash on empty message types (zero fields) */ + if (iter.pos->tag == 0) + continue; + + if (PB_ATYPE(type) == PB_ATYPE_STATIC) + { + if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL) + { + /* Set has_field to false. Still initialize the optional field + * itself also. */ + *(bool*)iter.pSize = false; + } + else if (PB_HTYPE(type) == PB_HTYPE_REPEATED) + { + /* Set array count to 0, no need to initialize contents. */ + *(size_t*)iter.pSize = 0; + continue; + } + + 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) + { + *(size_t*)iter.pSize = 0; + } + } + else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK) + { + /* Don't overwrite callback */ + } + } while (pb_field_next(&iter)); +} + +/********************* + * Decode all fields * + *********************/ + +bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct) +{ + uint8_t fields_seen[(PB_MAX_REQUIRED_FIELDS + 7) / 8] = {0, 0, 0, 0, 0, 0, 0, 0}; + uint32_t extension_range_start = 0; + pb_field_iterator_t iter; + + pb_field_init(&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_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) + { + fields_seen[iter.required_field_index >> 3] |= (uint8_t)(1 << (iter.required_field_index & 7)); + } + + 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_next(&iter)); + + /* Fixup if last field was also required. */ + if (PB_HTYPE(last_type) == PB_HTYPE_REQUIRED && iter.pos->tag != 0) + req_field_count++; + + /* Check the whole bytes */ + for (i = 0; i < (req_field_count >> 3); i++) + { + if (fields_seen[i] != 0xFF) + PB_RETURN_ERROR(stream, "missing required field"); + } + + /* Check the remaining bits */ + if (fields_seen[req_field_count >> 3] != (0xFF >> (8 - (req_field_count & 7)))) + 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); + pb_close_string_substream(stream, &substream); + return status; +} + +#ifdef PB_ENABLE_MALLOC +void pb_release(const pb_field_t fields[], void *dest_struct) +{ + pb_field_iterator_t iter; + pb_field_init(&iter, fields, dest_struct); + + do + { + pb_type_t type; + type = iter.pos->type; + + /* Avoid crash on empty message types (zero fields) */ + if (iter.pos->tag == 0) + continue; + + 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***)iter.pData; + size_t count = *(size_t*)iter.pSize; + while (count--) + { + pb_free(*pItem); + *pItem++ = NULL; + } + } + else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE) + { + /* Release fields in submessages */ + void *pItem = *(void**)iter.pData; + size_t count = (pItem ? 1 : 0); + + if (PB_HTYPE(type) == PB_HTYPE_REPEATED) + { + count = *(size_t*)iter.pSize; + } + + while (count--) + { + pb_release((const pb_field_t*)iter.pos->ptr, pItem); + pItem = (uint8_t*)pItem + iter.pos->data_size; + } + } + + /* Release main item */ + pb_free(*(void**)iter.pData); + *(void**)iter.pData = NULL; + } + } while (pb_field_next(&iter)); +} +#endif + +/* Field decoders */ + +bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest) +{ + uint64_t value; + if (!pb_decode_varint(stream, &value)) + return false; + + if (value & 1) + *dest = (int64_t)(~(value >> 1)); + else + *dest = (int64_t)(value >> 1); + + return true; +} + +bool pb_decode_fixed32(pb_istream_t *stream, void *dest) +{ + #ifdef __BIG_ENDIAN__ + uint8_t *bytes = (uint8_t*)dest; + uint8_t lebytes[4]; + + if (!pb_read(stream, lebytes, 4)) + return false; + + bytes[0] = lebytes[3]; + bytes[1] = lebytes[2]; + bytes[2] = lebytes[1]; + bytes[3] = lebytes[0]; + return true; + #else + return pb_read(stream, (uint8_t*)dest, 4); + #endif +} + +bool pb_decode_fixed64(pb_istream_t *stream, void *dest) +{ + #ifdef __BIG_ENDIAN__ + uint8_t *bytes = (uint8_t*)dest; + uint8_t lebytes[8]; + + if (!pb_read(stream, lebytes, 8)) + return false; + + bytes[0] = lebytes[7]; + bytes[1] = lebytes[6]; + bytes[2] = lebytes[5]; + bytes[3] = lebytes[4]; + bytes[4] = lebytes[3]; + bytes[5] = lebytes[2]; + bytes[6] = lebytes[1]; + bytes[7] = lebytes[0]; + return true; + #else + return pb_read(stream, (uint8_t*)dest, 8); + #endif +} + +static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + uint64_t value; + if (!pb_decode_varint(stream, &value)) + return false; + + switch (field->data_size) + { + case 1: *(int8_t*)dest = (int8_t)value; break; + case 2: *(int16_t*)dest = (int16_t)value; break; + case 4: *(int32_t*)dest = (int32_t)value; break; + case 8: *(int64_t*)dest = (int64_t)value; break; + default: PB_RETURN_ERROR(stream, "invalid data_size"); + } + + return true; +} + +static bool checkreturn pb_dec_uvarint(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + uint64_t value; + if (!pb_decode_varint(stream, &value)) + return false; + + switch (field->data_size) + { + case 4: *(uint32_t*)dest = (uint32_t)value; break; + case 8: *(uint64_t*)dest = value; break; + default: PB_RETURN_ERROR(stream, "invalid data_size"); + } + + return true; +} + +static bool checkreturn pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + int64_t value; + if (!pb_decode_svarint(stream, &value)) + return false; + + switch (field->data_size) + { + case 4: *(int32_t*)dest = (int32_t)value; break; + case 8: *(int64_t*)dest = value; break; + default: PB_RETURN_ERROR(stream, "invalid data_size"); + } + + return true; +} + +static bool checkreturn pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + UNUSED(field); + return pb_decode_fixed32(stream, dest); +} + +static bool checkreturn pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + UNUSED(field); + return pb_decode_fixed64(stream, dest); +} + +static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + uint32_t size; + pb_bytes_array_t *bdest; + + if (!pb_decode_varint32(stream, &size)) + return false; + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { +#ifndef PB_ENABLE_MALLOC + PB_RETURN_ERROR(stream, "no malloc support"); +#else + if (!allocate_field(stream, dest, PB_BYTES_ARRAY_T_ALLOCSIZE(size), 1)) + return false; + bdest = *(pb_bytes_array_t**)dest; +#endif + } + else + { + if (PB_BYTES_ARRAY_T_ALLOCSIZE(size) > field->data_size) + PB_RETURN_ERROR(stream, "bytes overflow"); + bdest = (pb_bytes_array_t*)dest; + } + + bdest->size = size; + return pb_read(stream, bdest->bytes, size); +} + +static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + uint32_t size; + size_t alloc_size; + bool status; + if (!pb_decode_varint32(stream, &size)) + return false; + + /* Space for null terminator */ + alloc_size = size + 1; + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { +#ifndef PB_ENABLE_MALLOC + PB_RETURN_ERROR(stream, "no malloc support"); +#else + if (!allocate_field(stream, dest, alloc_size, 1)) + return false; + dest = *(void**)dest; +#endif + } + else + { + if (alloc_size > field->data_size) + PB_RETURN_ERROR(stream, "string overflow"); + } + + status = pb_read(stream, (uint8_t*)dest, size); + *((uint8_t*)dest + size) = 0; + return status; +} + +static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest) +{ + bool status; + pb_istream_t substream; + const pb_field_t* submsg_fields = (const pb_field_t*)field->ptr; + + if (!pb_make_string_substream(stream, &substream)) + return false; + + if (field->ptr == NULL) + PB_RETURN_ERROR(stream, "invalid field descriptor"); + + /* New array entries need to be initialized, while required and optional + * submessages have already been initialized in the top-level pb_decode. */ + if (PB_HTYPE(field->type) == PB_HTYPE_REPEATED) + status = pb_decode(&substream, submsg_fields, dest); + else + status = pb_decode_noinit(&substream, submsg_fields, dest); + + pb_close_string_substream(stream, &substream); + return status; +} |