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Copy pathmqtt5_props.py
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236 lines (214 loc) · 7.86 KB
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import struct
PAYLOAD_FORMAT_INDICATOR = 1
MESSAGE_EXPIRY_INTERVAL = 2
CONTENT_TYPE = 3
RESPONSE_TOPIC = 8
CORRELATION_DATA = 9
SUBSCRIPTION_IDENTIFIER = 11
SESSION_EXPIRY_INTERVAL = 17
ASSIGNED_CLIENT_IDENTIFIER = 18
SERVER_KEEP_ALIVE = 19
AUTHENTICATION_METHOD = 21
AUTHENTICATION_DATA = 22
REQUEST_PROBLEM_INFO = 23
WILL_DELAY_INTERVAL = 24
REQUEST_RESPONSE_INFO = 25
RESPONSE_INFO = 26
SERVER_REFERENCE = 28
REASON_STRING = 31
RECEIVE_MAXIMUM = 33
TOPIC_ALIAS_MAXIMUM = 34
TOPIC_ALIAS = 35
MAXIMUM_QOS = 36
RETAIN_AVAILABLE = 37
USER_PROPERTY = 38
MAXIMUM_PACKET_SIZE = 39
WILDCARD_SUB_AVAILABLE = 40
SUBSCRIPTION_ID_AVAILABLE = 41
SHARED_SUB_AVAILABLE = 42
def gen_byte_prop(identifier, byte):
prop = struct.pack('BB', identifier, byte)
return prop
def gen_uint16_prop(identifier, word):
prop = struct.pack('!BH', identifier, word)
return prop
def gen_uint32_prop(identifier, word):
prop = struct.pack('!BI', identifier, word)
return prop
def gen_string_prop(identifier, s):
s = s.encode("utf-8")
prop = struct.pack('!BH%ds'%(len(s)), identifier, len(s), s)
return prop
def gen_string_pair_prop(identifier, s1, s2):
s1 = s1.encode("utf-8")
s2 = s2.encode("utf-8")
prop = struct.pack('!BH%dsH%ds'%(len(s1), len(s2)), identifier, len(s1), s1, len(s2), s2)
return prop
def gen_varint_prop(identifier, val):
v = pack_varint(val)
return struct.pack("!B"+str(len(v))+"s", identifier, v)
def pack_varint(varint):
s = b""
while True:
byte = varint % 128
varint = varint // 128
# If there are more digits to encode, set the top bit of this digit
if varint > 0:
byte = byte | 0x80
s = s + struct.pack("!B", byte)
if varint == 0:
return s
def prop_finalise(props):
return pack_varint(len(props)) + props
def gen_properties(properties_dict: dict) -> bytes:
props = b""
if properties_dict is None:
return props
for prop in properties_dict:
id = prop.get("identifier")
value = prop.get("value")
if id in (
PAYLOAD_FORMAT_INDICATOR,
REQUEST_PROBLEM_INFO,
REQUEST_RESPONSE_INFO,
MAXIMUM_QOS,
RETAIN_AVAILABLE,
WILDCARD_SUB_AVAILABLE,
SUBSCRIPTION_ID_AVAILABLE,
SHARED_SUB_AVAILABLE,
):
props += gen_byte_prop(id, value)
elif id in (
MESSAGE_EXPIRY_INTERVAL,
SESSION_EXPIRY_INTERVAL,
WILL_DELAY_INTERVAL,
MAXIMUM_PACKET_SIZE,
):
props += gen_uint32_prop(id, value)
elif id in (
CONTENT_TYPE,
RESPONSE_TOPIC,
CORRELATION_DATA,
ASSIGNED_CLIENT_IDENTIFIER,
AUTHENTICATION_METHOD,
AUTHENTICATION_DATA,
RESPONSE_INFO,
SERVER_REFERENCE,
REASON_STRING,
):
props += gen_string_prop(id, value)
elif id == SUBSCRIPTION_IDENTIFIER:
props += gen_varint_prop(id, value)
elif id in (
SERVER_KEEP_ALIVE,
RECEIVE_MAXIMUM,
TOPIC_ALIAS_MAXIMUM,
TOPIC_ALIAS,
):
props += gen_uint16_prop(id, value)
elif id == USER_PROPERTY:
props += gen_string_pair_prop(id, prop["name"], value)
return props
def unpack_varint(b: bytes):
def decode_len(b: bytes):
for i in range(len(b)):
if b[i] & 0x80 == 0:
return i + 1
return 0
var_len = decode_len(b)
variant = 0
for i in range(var_len - 1, -1, -1):
variant = 0x80 * variant + (struct.unpack("!B", b[i : i + 1])[0] & 0x7F)
return variant, var_len
def unpack_string(b: bytes):
str_len = struct.unpack("!B", b[0:1])[0]
str_value = struct.unpack(f"!{str_len}s", b[1 : str_len + 1])[0]
return str_value, str_len + 1
def unpack_property(b: bytes):
id = struct.unpack("!B", b[0:1])[0]
if id == PAYLOAD_FORMAT_INDICATOR:
return "PAYLOAD_FORMAT_INDICATOR", struct.unpack("!B", b[1:2])[0], 2
elif id == PAYLOAD_FORMAT_INDICATOR:
return "PAYLOAD_FORMAT_INDICATOR", struct.unpack("!B", b[1:2])[0], 2
elif id == REQUEST_PROBLEM_INFO:
return "REQUEST_PROBLEM_INFO", struct.unpack("!B", b[1:2])[0], 2
elif id == REQUEST_RESPONSE_INFO:
return "REQUEST_RESPONSE_INFO", struct.unpack("!B", b[1:2])[0], 2
elif id == MAXIMUM_QOS:
return "MAXIMUM_QOS", struct.unpack("!B", b[1:2])[0], 2
elif id == RETAIN_AVAILABLE:
return "RETAIN_AVAILABLE", struct.unpack("!B", b[1:2])[0], 2
elif id == WILDCARD_SUB_AVAILABLE:
return "WILDCARD_SUB_AVAILABLE", struct.unpack("!B", b[1:2])[0], 2
elif id == SUBSCRIPTION_ID_AVAILABLE:
return "SUBSCRIPTION_ID_AVAILABLE", struct.unpack("!B", b[1:2])[0], 2
elif id == SHARED_SUB_AVAILABLE:
return "SHARED_SUB_AVAILABLE", struct.unpack("!B", b[1:2])[0], 2
elif id == SERVER_KEEP_ALIVE:
return "SERVER_KEEP_ALIVE", struct.unpack("!H", b[1:3])[0], 3
elif id == RECEIVE_MAXIMUM:
return "RECEIVE_MAXIMUM", struct.unpack("!H", b[1:3])[0], 3
elif id == TOPIC_ALIAS_MAXIMUM:
return "TOPIC_ALIAS_MAXIMUM", struct.unpack("!H", b[1:3])[0], 3
elif id == TOPIC_ALIAS:
return "TOPIC_ALIAS", struct.unpack("!H", b[1:3])[0], 3
elif id == MESSAGE_EXPIRY_INTERVAL:
return "MESSAGE_EXPIRY_INTERVAL", struct.unpack("!B", b[1:5])[0], 5
elif id == SESSION_EXPIRY_INTERVAL:
return "SESSION_EXPIRY_INTERVAL", struct.unpack("!B", b[1:5])[0], 5
elif id == WILL_DELAY_INTERVAL:
return "WILL_DELAY_INTERVAL", struct.unpack("!B", b[1:5])[0], 5
elif id == MAXIMUM_PACKET_SIZE:
return "MAXIMUM_PACKET_SIZE", struct.unpack("!B", b[1:5])[0], 5
elif id == CONTENT_TYPE:
value, pack_len = unpack_string(b[1:])
return "CONTENT_TYPE", value, pack_len + 1
elif id == RESPONSE_TOPIC:
value, pack_len = unpack_string(b[1:])
return "RESPONSE_TOPIC", value, pack_len + 1
elif id == CORRELATION_DATA:
value, pack_len = unpack_string(b[1:])
return "CORRELATION_DATA", value, pack_len + 1
elif id == ASSIGNED_CLIENT_IDENTIFIER:
value, pack_len = unpack_string(b[1:])
return "ASSIGNED_CLIENT_IDENTIFIER", value, pack_len + 1
elif id == AUTHENTICATION_METHOD:
value, pack_len = unpack_string(b[1:])
return "AUTHENTICATION_METHOD", value, pack_len + 1
elif id == AUTHENTICATION_DATA:
value, pack_len = unpack_string(b[1:])
return "AUTHENTICATION_DATA", value, pack_len + 1
elif id == RESPONSE_INFO:
value, pack_len = unpack_string(b[1:])
return "RESPONSE_INFO", value, pack_len + 1
elif id == SERVER_REFERENCE:
value, pack_len = unpack_string(b[1:])
return "SERVER_REFERENCE", value, pack_len + 1
elif id == REASON_STRING:
value, pack_len = unpack_string(b[1:])
return "REASON_STRING", value, pack_len + 1
elif id == SUBSCRIPTION_IDENTIFIER:
value, pack_len = unpack_varint(b[1:])
return "SUBSCRIPTION_IDENTIFIER", value, pack_len + 1
elif id == USER_PROPERTY:
name, pack_name_len = unpack_string(b[1:])
value, pack_value_len = unpack_varint(b[1 + pack_name_len :])
return (
f"USER_PROPERTY:{name}",
value,
1 + pack_name_len + pack_value_len + pack_len,
)
else:
return f"<Unknown property ID={id}>", f"not decoded (len<={len(b)-1})", len(b)
def print_properties(b: bytes):
_, offset = unpack_varint(b)
props = []
while offset < len(b):
try:
key, value, prop_len = unpack_property(b[offset:])
offset += prop_len
props.append(f"{key}:{value}")
except struct.error:
props.append(f"decode error at offset {offset}: {b}")
break
return f"[{','.join(props)}]"