def __init__(self, data):
super().__init__()
self.protocol_name = None
self.protocol_level = None
self.connect_flags = ConnHeader.ConnectionFlags()
self.keep_alive = None
cursor = 0
# Parse the protocol name: it's a UTF-8 string, prepended with a 2 bytes length
self.protocol_name, data_len = parse_utf8_prefixed_string(data[cursor:])
cursor += data_len
# The following byte is the Protocol Level. For MQTT 3.1.1 should be 0x04
self.protocol_level = data[cursor]
cursor += 1
# Connection flags
flags = Byte(data[cursor]).binary
cursor += 1
# Populate connection flags
self.connect_flags.clean_session = flags[6] == '1'
self.connect_flags.will = flags[5] == '1'
self.connect_flags.will_qos = flags[3:5]
self.connect_flags.will_retain = flags[2] == '1'
self.connect_flags.user_name = flags[0] == '1'
self.connect_flags.password = flags[1] == '1'
# Keep Alive
self.keep_alive = struct.unpack(">H", data[cursor:cursor + 2])[0]
cursor += 2
self.length = cursor
def __init__(self, data):
super().__init__(length=0)
self.topics = []
cursor = 0
while cursor < len(data):
topic, topic_len = parse_utf8_prefixed_string(data[cursor:])
self.topics.append(topic)
cursor += topic_len
# Update len
self.length = cursor
def __init__(self, variable_header, data):
super().__init__(length=0)
self.client_identifier = None
self.will_topic = None
self.will_message = None
self.user_name = None
self.password = None
cursor = 0
# The payload of the CONNECT Packet contains one or more length-prefixed fields, whose presence is
# determined by the flags in the variable header. These fields, if present, MUST appear in the order
# Client Identifier, Will Topic, Will Message, User Name, Password [MQTT-3.1.3-1].
# Client identifier
self.client_identifier, field_len = parse_utf8_prefixed_string(
data[cursor:])
cursor += field_len
if variable_header.connect_flags.will:
self.will_topic, field_len = parse_utf8_prefixed_string(
data[cursor:])
cursor += field_len
self.will_message, field_len = parse_utf8_prefixed_string(
data[cursor:])
cursor += field_len
if variable_header.connect_flags.user_name:
self.user_name, field_len = parse_utf8_prefixed_string(
data[cursor:])
cursor += field_len
if variable_header.connect_flags.password:
self.password, field_len = parse_utf8_prefixed_string(
data[cursor:])
cursor += field_len
# Update len
self.length = cursor
def __init__(self, data, qos):
super().__init__()
self.packet_identifier = -1
self.topic_name = ""
cursor = 0
self.topic_name, data_len = parse_utf8_prefixed_string(data)
cursor += data_len
# Packet identifier is present only if QoS > 0
if qos.value > 0:
self.packet_identifier = struct.unpack(">H", data[cursor:cursor + 2])[0]
cursor += 2
self.length = cursor
def __init__(self, data):
super().__init__(length=0)
self.topics = {}
cursor = 0
# The payload of a SUBSCRIBE Packet contains a list of Topic Filters indicating the Topics to which the Client
# wants to subscribe. The Topic Filters in a SUBSCRIBE packet payload MUST be UTF-8 encoded strings
# We will scan the whole data byte stream until we parse all the topics.
while cursor < len(data):
topic, topic_len = parse_utf8_prefixed_string(data[cursor:])
cursor += topic_len
# After each topic name, there is one BYTE that encodes the requested QoS for that topic subscription
requested_qos = data[cursor]
cursor += 1
self.topics[topic] = QoS(requested_qos)
# Update len
self.length = cursor