diff options
Diffstat (limited to 'pb_decode.c')
| -rw-r--r-- | pb_decode.c | 96 |
1 files changed, 94 insertions, 2 deletions
diff --git a/pb_decode.c b/pb_decode.c index a079556e..e3be4127 100644 --- a/pb_decode.c +++ b/pb_decode.c @@ -28,7 +28,8 @@ static const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT] = { &pb_dec_bytes, &pb_dec_string, - &pb_dec_submessage + &pb_dec_submessage, + NULL /* extensions */ }; /************** @@ -336,8 +337,11 @@ 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) + if (iter->pos->tag == tag && + PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION) + { return true; + } pb_field_next(iter); } while (iter->field_index != start); @@ -472,6 +476,70 @@ static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_t } } +/* Default handler for extension fields. Expects a pb_field_t structure + * in extension->type->arg. */ +static bool checkreturn default_extension_handler(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; + bool dummy; + + 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 = &dummy; + + 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 && pos == stream->bytes_left) + { + bool status; + if (extension->type->decode) + status = extension->type->decode(stream, extension, tag, wire_type); + else + status = default_extension_handler(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; + 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) { @@ -528,6 +596,7 @@ static void pb_message_set_to_defaults(const pb_field_t fields[], void *dest_str 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}; /* Used to check for required fields */ + uint32_t extension_range_start = 0; pb_field_iterator_t iter; pb_field_init(&iter, fields, dest_struct); @@ -548,6 +617,29 @@ bool checkreturn pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[ 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; |