ret_code_t nfc_t4t_file_control_tlv_parse(nfc_t4t_tlv_block_t * p_file_control_tlv,
uint8_t * p_raw_data,
uint16_t * p_len)
{
ret_code_t err_code;
uint8_t * p_offset = p_raw_data;
if (*p_len < TLV_MIN_TL_FIELD_LEN)
{
return NRF_ERROR_INVALID_LENGTH;
}
memset(p_file_control_tlv, 0, sizeof(nfc_t4t_tlv_block_t));
// Handle type field of TLV block.
p_file_control_tlv->type = *p_offset;
p_offset += TLV_TYPE_FIELD_LEN;
// Handle length field of TLV block.
if (*p_offset == TLV_LEN_LONG_FORMAT_TOKEN)
{
if (*p_len < TLV_MIN_LONG_FORMAT_TL_FIELD_LEN)
{
return NRF_ERROR_INVALID_LENGTH;
}
p_file_control_tlv->length = uint16_big_decode(p_offset + TLV_LEN_LONG_FORMAT_TOKEN_SIZE);
p_offset += TLV_LEN_LONG_FIELD_LEN;
if (p_file_control_tlv->length < TLV_LEN_LONG_FORMAT_MIN_VALUE)
{
return NRF_ERROR_INVALID_DATA;
}
}
else
{
p_file_control_tlv->length = *p_offset;
p_offset += TLV_LEN_SHORT_FIELD_LEN;
}
// Calculate the total TLV block size.
uint16_t tlv_block_len = (p_offset - p_raw_data) + p_file_control_tlv->length;
if (*p_len < tlv_block_len)
{
return NRF_ERROR_INVALID_LENGTH;
}
*p_len = tlv_block_len;
// Validate if type and length fields contain values supported by Type 4 Tag.
err_code = nfc_t4t_file_control_tl_validate(p_file_control_tlv);
VERIFY_SUCCESS(err_code);
// Handle value field of TLV block.
err_code = nfc_t4t_file_control_value_parse(p_file_control_tlv, p_offset);
return err_code;
}
/**
* @brief Function for reading the length field of a TLV block from the p_raw_data buffer.
*
* This function reads the length field of a TLV block and inserts its value into a structure
* pointed by the p_tlv_buf pointer.
*
* @param[in] p_type_2_tag Pointer to the structure that contains Type 2 Tag data parsed so far.
* @param[in] p_raw_data Pointer to the buffer with a raw data from the tag.
* @param[in,out] p_l_offset As input: offset of the length field to read. As output: offset of
* the first byte after the length field.
* @param[out] p_tlv_buf Pointer to a @ref tlv_block_t structure where the length will be
* inserted.
*
* @retval NRF_SUCCESS If the length field at specified offset is correct.
* @retval NRF_ERROR_INVALID_DATA If the length field at specified offset exceeds the data
* area specified in the Capability Container or has
* incorrect format.
*
*/
static ret_code_t type_2_tag_length_extract(type_2_tag_t * p_type_2_tag,
uint8_t * p_raw_data,
uint16_t * p_l_offset,
tlv_block_t * p_tlv_buf)
{
uint16_t length;
if (!type_2_tag_is_field_within_data_range(p_type_2_tag, *p_l_offset, TLV_L_SHORT_LENGTH))
{
return NRF_ERROR_INVALID_DATA;
}
length = p_raw_data[*p_l_offset];
if (length == TLV_L_FORMAT_FLAG)
{
// Check another two bytes.
if (!type_2_tag_is_field_within_data_range(p_type_2_tag, *p_l_offset, TLV_L_LONG_LENGTH))
{
return NRF_ERROR_INVALID_DATA;
}
length = uint16_big_decode(&p_raw_data[*p_l_offset + 1]);
// Long length value cannot be lower than 0xFF.
if (length < 0xFF)
{
return NRF_ERROR_INVALID_DATA;
}
p_tlv_buf->length = length;
*p_l_offset += TLV_L_LONG_LENGTH;
}
else
{
p_tlv_buf->length = length;
*p_l_offset += TLV_L_SHORT_LENGTH;
}
return NRF_SUCCESS;
}
/**
* @brief Function for parsing value field of File Control TLV.
*/
static ret_code_t nfc_t4t_file_control_value_parse(nfc_t4t_tlv_block_t * p_file_control_tlv,
uint8_t * p_value_buff)
{
nfc_t4t_file_control_val_t * p_control_tlv_val;
// Handle File Identifier field.
p_control_tlv_val = &p_file_control_tlv->value;
p_control_tlv_val->file_id = uint16_big_decode(p_value_buff);
p_value_buff += FILE_CONTROL_FILE_ID_FIELD_SIZE;
switch (p_control_tlv_val->file_id)
{
case FILE_ID_INVALID_VALUE_0:
case FILE_ID_INVALID_VALUE_1:
case FILE_ID_INVALID_VALUE_2:
case FILE_ID_INVALID_VALUE_3:
case FILE_ID_INVALID_VALUE_4:
case FILE_ID_INVALID_VALUE_5:
return NRF_ERROR_INVALID_DATA;
default:
break;
}
// Handle Max file size field.
switch (p_file_control_tlv->type)
{
case NDEF_FILE_CONTROL_TLV:
p_control_tlv_val->max_file_size = uint16_big_decode(p_value_buff);
p_value_buff += NDEF_FILE_MAX_SIZE_FIELD_SIZE;
NFC_T4T_FILE_CONTROL_MAX_SIZE_FIELD_RANGE_VERIFY(p_control_tlv_val->max_file_size,
NDEF_FILE_MAX_SIZE_MIN_VAL,
NDEF_FILE_MAX_SIZE_MAX_VAL);
break;
case PROPRIETARY_FILE_CONTROL_TLV:
p_control_tlv_val->max_file_size = uint16_big_decode(p_value_buff);
p_value_buff += PROPRIETARY_FILE_MAX_SIZE_FIELD_SIZE;
NFC_T4T_FILE_CONTROL_MAX_SIZE_FIELD_RANGE_VERIFY(p_control_tlv_val->max_file_size,
PROPRIETARY_FILE_MAX_SIZE_MIN_VAL,
PROPRIETARY_FILE_MAX_SIZE_MAX_VAL);
break;
case EXTENDED_NDEF_FILE_CONTROL_TLV:
p_control_tlv_val->max_file_size = uint32_big_decode(p_value_buff);
p_value_buff += EXTENDED_NDEF_FILE_MAX_SIZE_FIELD_SIZE;
NFC_T4T_FILE_CONTROL_MAX_SIZE_FIELD_RANGE_VERIFY(p_control_tlv_val->max_file_size,
EXTENDED_NDEF_FILE_MAX_SIZE_MIN_VAL,
EXTENDED_NDEF_FILE_MAX_SIZE_MAX_VAL);
break;
}
// Handle read access condition field.
p_control_tlv_val->read_access = *p_value_buff;
p_value_buff += FILE_CONTROL_READ_ACCESS_FIELD_SIZE;
// Handle write access condition field.
p_control_tlv_val->write_access = *p_value_buff;
return NRF_SUCCESS;
}
