mirror of
https://github.com/PiBrewing/craftbeerpi4.git
synced 2024-12-23 22:14:56 +01:00
409 lines
16 KiB
Python
409 lines
16 KiB
Python
"""
|
|
*******************************************************************
|
|
Copyright (c) 2017, 2019 IBM Corp.
|
|
|
|
All rights reserved. This program and the accompanying materials
|
|
are made available under the terms of the Eclipse Public License v1.0
|
|
and Eclipse Distribution License v1.0 which accompany this distribution.
|
|
|
|
The Eclipse Public License is available at
|
|
http://www.eclipse.org/legal/epl-v10.html
|
|
and the Eclipse Distribution License is available at
|
|
http://www.eclipse.org/org/documents/edl-v10.php.
|
|
|
|
Contributors:
|
|
Ian Craggs - initial implementation and/or documentation
|
|
*******************************************************************
|
|
"""
|
|
|
|
import sys, struct
|
|
|
|
from .packettypes import PacketTypes
|
|
|
|
|
|
class MQTTException(Exception):
|
|
pass
|
|
|
|
|
|
class MalformedPacket(MQTTException):
|
|
pass
|
|
|
|
|
|
def writeInt16(length):
|
|
# serialize a 16 bit integer to network format
|
|
return bytearray(struct.pack("!H", length))
|
|
|
|
|
|
def readInt16(buf):
|
|
# deserialize a 16 bit integer from network format
|
|
return struct.unpack("!H", buf[:2])[0]
|
|
|
|
|
|
def writeInt32(length):
|
|
# serialize a 32 bit integer to network format
|
|
return bytearray(struct.pack("!L", length))
|
|
|
|
|
|
def readInt32(buf):
|
|
# deserialize a 32 bit integer from network format
|
|
return struct.unpack("!L", buf[:4])[0]
|
|
|
|
|
|
def writeUTF(data):
|
|
# data could be a string, or bytes. If string, encode into bytes with utf-8
|
|
if sys.version_info[0] < 3:
|
|
data = bytearray(data, 'utf-8')
|
|
else:
|
|
data = data if type(data) == type(b"") else bytes(data, "utf-8")
|
|
return writeInt16(len(data)) + data
|
|
|
|
|
|
def readUTF(buffer, maxlen):
|
|
if maxlen >= 2:
|
|
length = readInt16(buffer)
|
|
else:
|
|
raise MalformedPacket("Not enough data to read string length")
|
|
maxlen -= 2
|
|
if length > maxlen:
|
|
raise MalformedPacket("Length delimited string too long")
|
|
buf = buffer[2:2+length].decode("utf-8")
|
|
# look for chars which are invalid for MQTT
|
|
for c in buf: # look for D800-DFFF in the UTF string
|
|
ord_c = ord(c)
|
|
if ord_c >= 0xD800 and ord_c <= 0xDFFF:
|
|
raise MalformedPacket("[MQTT-1.5.4-1] D800-DFFF found in UTF-8 data")
|
|
if ord_c == 0x00: # look for null in the UTF string
|
|
raise MalformedPacket("[MQTT-1.5.4-2] Null found in UTF-8 data")
|
|
if ord_c == 0xFEFF:
|
|
raise MalformedPacket("[MQTT-1.5.4-3] U+FEFF in UTF-8 data")
|
|
return buf, length+2
|
|
|
|
|
|
def writeBytes(buffer):
|
|
return writeInt16(len(buffer)) + buffer
|
|
|
|
|
|
def readBytes(buffer):
|
|
length = readInt16(buffer)
|
|
return buffer[2:2+length], length+2
|
|
|
|
|
|
class VariableByteIntegers: # Variable Byte Integer
|
|
"""
|
|
MQTT variable byte integer helper class. Used
|
|
in several places in MQTT v5.0 properties.
|
|
|
|
"""
|
|
|
|
@staticmethod
|
|
def encode(x):
|
|
"""
|
|
Convert an integer 0 <= x <= 268435455 into multi-byte format.
|
|
Returns the buffer convered from the integer.
|
|
"""
|
|
assert 0 <= x <= 268435455
|
|
buffer = b''
|
|
while 1:
|
|
digit = x % 128
|
|
x //= 128
|
|
if x > 0:
|
|
digit |= 0x80
|
|
if sys.version_info[0] >= 3:
|
|
buffer += bytes([digit])
|
|
else:
|
|
buffer += bytes(chr(digit))
|
|
if x == 0:
|
|
break
|
|
return buffer
|
|
|
|
@staticmethod
|
|
def decode(buffer):
|
|
"""
|
|
Get the value of a multi-byte integer from a buffer
|
|
Return the value, and the number of bytes used.
|
|
|
|
[MQTT-1.5.5-1] the encoded value MUST use the minimum number of bytes necessary to represent the value
|
|
"""
|
|
multiplier = 1
|
|
value = 0
|
|
bytes = 0
|
|
while 1:
|
|
bytes += 1
|
|
digit = buffer[0]
|
|
buffer = buffer[1:]
|
|
value += (digit & 127) * multiplier
|
|
if digit & 128 == 0:
|
|
break
|
|
multiplier *= 128
|
|
return (value, bytes)
|
|
|
|
|
|
class Properties(object):
|
|
"""MQTT v5.0 properties class.
|
|
|
|
See Properties.names for a list of accepted property names along with their numeric values.
|
|
|
|
See Properties.properties for the data type of each property.
|
|
|
|
Example of use:
|
|
|
|
publish_properties = Properties(PacketTypes.PUBLISH)
|
|
publish_properties.UserProperty = ("a", "2")
|
|
publish_properties.UserProperty = ("c", "3")
|
|
|
|
First the object is created with packet type as argument, no properties will be present at
|
|
this point. Then properties are added as attributes, the name of which is the string property
|
|
name without the spaces.
|
|
|
|
"""
|
|
|
|
def __init__(self, packetType):
|
|
self.packetType = packetType
|
|
self.types = ["Byte", "Two Byte Integer", "Four Byte Integer", "Variable Byte Integer",
|
|
"Binary Data", "UTF-8 Encoded String", "UTF-8 String Pair"]
|
|
|
|
self.names = {
|
|
"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 Information": 23,
|
|
"Will Delay Interval": 24,
|
|
"Request Response Information": 25,
|
|
"Response Information": 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 Subscription Available": 40,
|
|
"Subscription Identifier Available": 41,
|
|
"Shared Subscription Available": 42
|
|
}
|
|
|
|
self.properties = {
|
|
# id: type, packets
|
|
# payload format indicator
|
|
1: (self.types.index("Byte"), [PacketTypes.PUBLISH, PacketTypes.WILLMESSAGE]),
|
|
2: (self.types.index("Four Byte Integer"), [PacketTypes.PUBLISH, PacketTypes.WILLMESSAGE]),
|
|
3: (self.types.index("UTF-8 Encoded String"), [PacketTypes.PUBLISH, PacketTypes.WILLMESSAGE]),
|
|
8: (self.types.index("UTF-8 Encoded String"), [PacketTypes.PUBLISH, PacketTypes.WILLMESSAGE]),
|
|
9: (self.types.index("Binary Data"), [PacketTypes.PUBLISH, PacketTypes.WILLMESSAGE]),
|
|
11: (self.types.index("Variable Byte Integer"),
|
|
[PacketTypes.PUBLISH, PacketTypes.SUBSCRIBE]),
|
|
17: (self.types.index("Four Byte Integer"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK, PacketTypes.DISCONNECT]),
|
|
18: (self.types.index("UTF-8 Encoded String"), [PacketTypes.CONNACK]),
|
|
19: (self.types.index("Two Byte Integer"), [PacketTypes.CONNACK]),
|
|
21: (self.types.index("UTF-8 Encoded String"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK, PacketTypes.AUTH]),
|
|
22: (self.types.index("Binary Data"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK, PacketTypes.AUTH]),
|
|
23: (self.types.index("Byte"),
|
|
[PacketTypes.CONNECT]),
|
|
24: (self.types.index("Four Byte Integer"), [PacketTypes.WILLMESSAGE]),
|
|
25: (self.types.index("Byte"), [PacketTypes.CONNECT]),
|
|
26: (self.types.index("UTF-8 Encoded String"), [PacketTypes.CONNACK]),
|
|
28: (self.types.index("UTF-8 Encoded String"),
|
|
[PacketTypes.CONNACK, PacketTypes.DISCONNECT]),
|
|
31: (self.types.index("UTF-8 Encoded String"),
|
|
[PacketTypes.CONNACK, PacketTypes.PUBACK, PacketTypes.PUBREC,
|
|
PacketTypes.PUBREL, PacketTypes.PUBCOMP, PacketTypes.SUBACK,
|
|
PacketTypes.UNSUBACK, PacketTypes.DISCONNECT, PacketTypes.AUTH]),
|
|
33: (self.types.index("Two Byte Integer"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK]),
|
|
34: (self.types.index("Two Byte Integer"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK]),
|
|
35: (self.types.index("Two Byte Integer"), [PacketTypes.PUBLISH]),
|
|
36: (self.types.index("Byte"), [PacketTypes.CONNACK]),
|
|
37: (self.types.index("Byte"), [PacketTypes.CONNACK]),
|
|
38: (self.types.index("UTF-8 String Pair"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK,
|
|
PacketTypes.PUBLISH, PacketTypes.PUBACK,
|
|
PacketTypes.PUBREC, PacketTypes.PUBREL, PacketTypes.PUBCOMP,
|
|
PacketTypes.SUBSCRIBE, PacketTypes.SUBACK,
|
|
PacketTypes.UNSUBSCRIBE, PacketTypes.UNSUBACK,
|
|
PacketTypes.DISCONNECT, PacketTypes.AUTH, PacketTypes.WILLMESSAGE]),
|
|
39: (self.types.index("Four Byte Integer"),
|
|
[PacketTypes.CONNECT, PacketTypes.CONNACK]),
|
|
40: (self.types.index("Byte"), [PacketTypes.CONNACK]),
|
|
41: (self.types.index("Byte"), [PacketTypes.CONNACK]),
|
|
42: (self.types.index("Byte"), [PacketTypes.CONNACK]),
|
|
}
|
|
|
|
def allowsMultiple(self, compressedName):
|
|
return self.getIdentFromName(compressedName) in [11, 38]
|
|
|
|
def getIdentFromName(self, compressedName):
|
|
# return the identifier corresponding to the property name
|
|
result = -1
|
|
for name in self.names.keys():
|
|
if compressedName == name.replace(' ', ''):
|
|
result = self.names[name]
|
|
break
|
|
return result
|
|
|
|
def __setattr__(self, name, value):
|
|
name = name.replace(' ', '')
|
|
privateVars = ["packetType", "types", "names", "properties"]
|
|
if name in privateVars:
|
|
object.__setattr__(self, name, value)
|
|
else:
|
|
# the name could have spaces in, or not. Remove spaces before assignment
|
|
if name not in [aname.replace(' ', '') for aname in self.names.keys()]:
|
|
raise MQTTException(
|
|
"Property name must be one of "+str(self.names.keys()))
|
|
# check that this attribute applies to the packet type
|
|
if self.packetType not in self.properties[self.getIdentFromName(name)][1]:
|
|
raise MQTTException("Property %s does not apply to packet type %s"
|
|
% (name, PacketTypes.Names[self.packetType]))
|
|
if self.allowsMultiple(name):
|
|
if type(value) != type([]):
|
|
value = [value]
|
|
if hasattr(self, name):
|
|
value = object.__getattribute__(self, name) + value
|
|
object.__setattr__(self, name, value)
|
|
|
|
def __str__(self):
|
|
buffer = "["
|
|
first = True
|
|
for name in self.names.keys():
|
|
compressedName = name.replace(' ', '')
|
|
if hasattr(self, compressedName):
|
|
if not first:
|
|
buffer += ", "
|
|
buffer += compressedName + " : " + \
|
|
str(getattr(self, compressedName))
|
|
first = False
|
|
buffer += "]"
|
|
return buffer
|
|
|
|
def json(self):
|
|
data = {}
|
|
for name in self.names.keys():
|
|
compressedName = name.replace(' ', '')
|
|
if hasattr(self, compressedName):
|
|
data[compressedName] = getattr(self, compressedName)
|
|
return data
|
|
|
|
def isEmpty(self):
|
|
rc = True
|
|
for name in self.names.keys():
|
|
compressedName = name.replace(' ', '')
|
|
if hasattr(self, compressedName):
|
|
rc = False
|
|
break
|
|
return rc
|
|
|
|
def clear(self):
|
|
for name in self.names.keys():
|
|
compressedName = name.replace(' ', '')
|
|
if hasattr(self, compressedName):
|
|
delattr(self, compressedName)
|
|
|
|
def writeProperty(self, identifier, type, value):
|
|
buffer = b""
|
|
buffer += VariableByteIntegers.encode(identifier) # identifier
|
|
if type == self.types.index("Byte"): # value
|
|
if sys.version_info[0] < 3:
|
|
buffer += chr(value)
|
|
else:
|
|
buffer += bytes([value])
|
|
elif type == self.types.index("Two Byte Integer"):
|
|
buffer += writeInt16(value)
|
|
elif type == self.types.index("Four Byte Integer"):
|
|
buffer += writeInt32(value)
|
|
elif type == self.types.index("Variable Byte Integer"):
|
|
buffer += VariableByteIntegers.encode(value)
|
|
elif type == self.types.index("Binary Data"):
|
|
buffer += writeBytes(value)
|
|
elif type == self.types.index("UTF-8 Encoded String"):
|
|
buffer += writeUTF(value)
|
|
elif type == self.types.index("UTF-8 String Pair"):
|
|
buffer += writeUTF(value[0]) + writeUTF(value[1])
|
|
return buffer
|
|
|
|
def pack(self):
|
|
# serialize properties into buffer for sending over network
|
|
buffer = b""
|
|
for name in self.names.keys():
|
|
compressedName = name.replace(' ', '')
|
|
if hasattr(self, compressedName):
|
|
identifier = self.getIdentFromName(compressedName)
|
|
attr_type = self.properties[identifier][0]
|
|
if self.allowsMultiple(compressedName):
|
|
for prop in getattr(self, compressedName):
|
|
buffer += self.writeProperty(identifier,
|
|
attr_type, prop)
|
|
else:
|
|
buffer += self.writeProperty(identifier, attr_type,
|
|
getattr(self, compressedName))
|
|
return VariableByteIntegers.encode(len(buffer)) + buffer
|
|
|
|
def readProperty(self, buffer, type, propslen):
|
|
if type == self.types.index("Byte"):
|
|
value = buffer[0]
|
|
valuelen = 1
|
|
elif type == self.types.index("Two Byte Integer"):
|
|
value = readInt16(buffer)
|
|
valuelen = 2
|
|
elif type == self.types.index("Four Byte Integer"):
|
|
value = readInt32(buffer)
|
|
valuelen = 4
|
|
elif type == self.types.index("Variable Byte Integer"):
|
|
value, valuelen = VariableByteIntegers.decode(buffer)
|
|
elif type == self.types.index("Binary Data"):
|
|
value, valuelen = readBytes(buffer)
|
|
elif type == self.types.index("UTF-8 Encoded String"):
|
|
value, valuelen = readUTF(buffer, propslen)
|
|
elif type == self.types.index("UTF-8 String Pair"):
|
|
value, valuelen = readUTF(buffer, propslen)
|
|
buffer = buffer[valuelen:] # strip the bytes used by the value
|
|
value1, valuelen1 = readUTF(buffer, propslen - valuelen)
|
|
value = (value, value1)
|
|
valuelen += valuelen1
|
|
return value, valuelen
|
|
|
|
def getNameFromIdent(self, identifier):
|
|
rc = None
|
|
for name in self.names:
|
|
if self.names[name] == identifier:
|
|
rc = name
|
|
return rc
|
|
|
|
def unpack(self, buffer):
|
|
if sys.version_info[0] < 3:
|
|
buffer = bytearray(buffer)
|
|
self.clear()
|
|
# deserialize properties into attributes from buffer received from network
|
|
propslen, VBIlen = VariableByteIntegers.decode(buffer)
|
|
buffer = buffer[VBIlen:] # strip the bytes used by the VBI
|
|
propslenleft = propslen
|
|
while propslenleft > 0: # properties length is 0 if there are none
|
|
identifier, VBIlen = VariableByteIntegers.decode(
|
|
buffer) # property identifier
|
|
buffer = buffer[VBIlen:] # strip the bytes used by the VBI
|
|
propslenleft -= VBIlen
|
|
attr_type = self.properties[identifier][0]
|
|
value, valuelen = self.readProperty(
|
|
buffer, attr_type, propslenleft)
|
|
buffer = buffer[valuelen:] # strip the bytes used by the value
|
|
propslenleft -= valuelen
|
|
propname = self.getNameFromIdent(identifier)
|
|
compressedName = propname.replace(' ', '')
|
|
if not self.allowsMultiple(compressedName) and hasattr(self, compressedName):
|
|
raise MQTTException(
|
|
"Property '%s' must not exist more than once" % property)
|
|
setattr(self, propname, value)
|
|
return self, propslen + VBIlen
|