def get_packet(in_data):
valid_packet = False
packet = None
if in_data != b'':
header = get_header(in_data)
checksum = header[1]
pac_type = header[2]
seq_no = header[3]
data_len = header[4]
if data_len >= len(in_data) - 20:
data = get_data(in_data, data_len)
packet = Packet(pac_type, seq_no, data_len, data, checksum)
valid_packet = packet.checksum == packet.calculate_checksum()
return packet, valid_packet
