asyncua.ua.ua_binary.extensionobject_to_binary() - Code Metrics - FreeOpcUa/opcua-asyncio - Measure and Improve Code Quality continuously with Scrutinizer

asyncua.ua.ua_binary.extensionobject_to_binary() A
last analyzed 2020-12-22 17:52 UTC

↳ Parent: asyncua.ua.ua_binary

Complexity

Conditions

Size

Total Lines	23
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	4
eloc	16
nop	1
dl	0
loc	23
rs	9.6
c	0
b	0
f	0

"""
Binary protocol specific functions and constants
"""

import struct
import logging
import uuid
from enum import IntEnum, Enum

from .uaerrors import UaError
from ..common.utils import Buffer
from asyncua import ua

logger = logging.getLogger('__name__')


def test_bit(data, offset):
    mask = 1 << offset
    return data & mask


def set_bit(data, offset):
    mask = 1 << offset
    return data | mask


def unset_bit(data, offset):
    mask = 1 << offset
    return data & ~mask


class _DateTime(object):
    @staticmethod
    def pack(dt):
        epch = ua.datetime_to_win_epoch(dt)
        return Primitives.Int64.pack(epch)

    @staticmethod
    def unpack(data):
        epch = Primitives.Int64.unpack(data)
        return ua.win_epoch_to_datetime(epch)


class _Bytes(object):
    @staticmethod
    def pack(data):
        if data is None:
            return Primitives.Int32.pack(-1)
        length = len(data)
        return Primitives.Int32.pack(length) + data

    @staticmethod
    def unpack(data):
        length = Primitives.Int32.unpack(data)
        if length == -1:
            return None
        return data.read(length)


class _String(object):
    @staticmethod
    def pack(string):
        if string is not None:
            string = string.encode('utf-8')
        return _Bytes.pack(string)

    @staticmethod
    def unpack(data):
        b = _Bytes.unpack(data)
        if b is None:
            return b
        return b.decode('utf-8')


class _Null(object):
    @staticmethod
    def pack(data):
        return b''

    @staticmethod
    def unpack(data):
        return None


class _Guid(object):
    @staticmethod
    def pack(guid):
        # convert python UUID 6 field format to OPC UA 4 field format
        f1 = Primitives.UInt32.pack(guid.time_low)
        f2 = Primitives.UInt16.pack(guid.time_mid)
        f3 = Primitives.UInt16.pack(guid.time_hi_version)
        f4a = Primitives.Byte.pack(guid.clock_seq_hi_variant)
        f4b = Primitives.Byte.pack(guid.clock_seq_low)
        f4c = struct.pack('>Q', guid.node)[2:8]  # no primitive .pack available for 6 byte int
        f4 = f4a + f4b + f4c
        # concat byte fields
        b = f1 + f2 + f3 + f4

        return b

    @staticmethod
    def unpack(data):
        # convert OPC UA 4 field format to python UUID bytes
        f1 = struct.pack('>I', Primitives.UInt32.unpack(data))
        f2 = struct.pack('>H', Primitives.UInt16.unpack(data))
        f3 = struct.pack('>H', Primitives.UInt16.unpack(data))
        f4 = data.read(8)
        # concat byte fields
        b = f1 + f2 + f3 + f4

        return uuid.UUID(bytes=b)


class _Primitive1(object):
    def __init__(self, fmt):
        self._fmt = fmt
        st = struct.Struct(fmt.format(1))
        self.size = st.size
        self.format = st.format

    def pack(self, data):
        return struct.pack(self.format, data)

    def unpack(self, data):
        return struct.unpack(self.format, data.read(self.size))[0]

    def pack_array(self, data):
        if data is None:
            return Primitives.Int32.pack(-1)
        if not isinstance(data, list):
            logger.warning(f'ua_binary.py > _Primitive1 > pack_array > data: {data} is not a instance of "list"!')
            return Primitives.Int32.pack(-1) # to prevent crashing while runtime
        size_data = Primitives.Int32.pack(len(data))
        return size_data + struct.pack(self._fmt.format(len(data)), *data)

    def unpack_array(self, data, length):
        if length == -1:
            return None
        if length == 0:
            return ()
        return struct.unpack(self._fmt.format(length), data.read(self.size * length))


class Primitives1(object):
    SByte = _Primitive1('<{:d}b')
    Int16 = _Primitive1('<{:d}h')
    Int32 = _Primitive1('<{:d}i')
    Int64 = _Primitive1('<{:d}q')
    Byte = _Primitive1('<{:d}B')
    Char = Byte
    UInt16 = _Primitive1('<{:d}H')
    UInt32 = _Primitive1('<{:d}I')
    UInt64 = _Primitive1('<{:d}Q')
    Boolean = _Primitive1('<{:d}?')
    Double = _Primitive1('<{:d}d')
    Float = _Primitive1('<{:d}f')


class Primitives(Primitives1):
    Null = _Null()
    String = _String()
    Bytes = _Bytes()
    ByteString = _Bytes()
    CharArray = _String()
    DateTime = _DateTime()
    Guid = _Guid()


def pack_uatype(vtype, value):
    if hasattr(Primitives, vtype.name):
        return getattr(Primitives, vtype.name).pack(value)
    elif vtype.value > 25:
        return Primitives.Bytes.pack(value)
    elif vtype == ua.VariantType.ExtensionObject:
        return extensionobject_to_binary(value)
    elif vtype in (ua.VariantType.NodeId, ua.VariantType.ExpandedNodeId):
        return nodeid_to_binary(value)
    elif vtype == ua.VariantType.Variant:
        return variant_to_binary(value)
    else:
        return struct_to_binary(value)


def unpack_uatype(vtype, data):
    if hasattr(Primitives, vtype.name):
        st = getattr(Primitives, vtype.name)
        return st.unpack(data)
    elif vtype.value > 25:
        return Primitives.Bytes.unpack(data)
    elif vtype == ua.VariantType.ExtensionObject:
        return extensionobject_from_binary(data)
    elif vtype in (ua.VariantType.NodeId, ua.VariantType.ExpandedNodeId):
        return nodeid_from_binary(data)
    elif vtype == ua.VariantType.Variant:
        return variant_from_binary(data)
    else:
        if hasattr(ua, vtype.name):
            cls = getattr(ua, vtype.name)
            return struct_from_binary(cls, data)
        else:
            raise UaError(f'Cannot unpack unknown variant type {vtype}')


def pack_uatype_array(vtype, array):
    if hasattr(Primitives1, vtype.name):
        data_type = getattr(Primitives1, vtype.name)
        return data_type.pack_array(array)
    if array is None:
        return b'\xff\xff\xff\xff'
    length = len(array)
    b = [pack_uatype(vtype, val) for val in array]
    b.insert(0, Primitives.Int32.pack(length))
    return b"".join(b)


def unpack_uatype_array(vtype, data):
    length = Primitives.Int32.unpack(data)
    if length == -1:
        return None
    elif hasattr(Primitives1, vtype.name):
        data_type = getattr(Primitives1, vtype.name)
        # Remark: works without tuple conversion to list.
        return list(data_type.unpack_array(data, length))
    else:
        # Revert to slow serial unpacking.
        return [unpack_uatype(vtype, data) for _ in range(length)]


def struct_to_binary(obj):
    packet = []
    has_switch = hasattr(obj, 'ua_switches')
    if has_switch:
        for name, switch in obj.ua_switches.items():
            member = getattr(obj, name)
            container_name, idx = switch
            if member is not None:
                container_val = getattr(obj, container_name)
                container_val = container_val | 1 << idx
                setattr(obj, container_name, container_val)
    for name, uatype in obj.ua_types:
        val = getattr(obj, name)
        if uatype.startswith('ListOf'):
            packet.append(list_to_binary(uatype[6:], val))
        else:
            if has_switch and val is None and name in obj.ua_switches:
                pass
            else:
                packet.append(to_binary(uatype, val))
    return b''.join(packet)


def to_binary(uatype, val):
    """
    Pack a python object to binary given a string defining its type
    """
    if uatype.startswith('ListOf'):
        # if isinstance(val, (list, tuple)):
        return list_to_binary(uatype[6:], val)
    elif type(uatype) is str and hasattr(ua.VariantType, uatype):
        vtype = getattr(ua.VariantType, uatype)
        return pack_uatype(vtype, val)
    elif type(uatype) is str and hasattr(Primitives, uatype):
        return getattr(Primitives, uatype).pack(val)
    elif isinstance(val, (IntEnum, Enum)):
        return Primitives.UInt32.pack(val.value)
    elif isinstance(val, ua.NodeId):
        return nodeid_to_binary(val)
    elif isinstance(val, ua.Variant):
        return variant_to_binary(val)
    elif hasattr(val, 'ua_types'):
        return struct_to_binary(val)
    else:
        raise UaError(f'No known way to pack {val} of type {uatype} to ua binary')


def list_to_binary(uatype, val):
    if val is None:
        return Primitives.Int32.pack(-1)
    if hasattr(Primitives1, uatype):
        data_type = getattr(Primitives1, uatype)
        return data_type.pack_array(val)
    data_size = Primitives.Int32.pack(len(val))
    pack = [to_binary(uatype, el) for el in val]
    pack.insert(0, data_size)
    return b''.join(pack)


def nodeid_to_binary(nodeid):
    if nodeid.NodeIdType == ua.NodeIdType.TwoByte:
        return struct.pack('<BB', nodeid.NodeIdType.value, nodeid.Identifier)
    elif nodeid.NodeIdType == ua.NodeIdType.FourByte:
        return struct.pack('<BBH', nodeid.NodeIdType.value, nodeid.NamespaceIndex, nodeid.Identifier)
    elif nodeid.NodeIdType == ua.NodeIdType.Numeric:
        data = struct.pack('<BHI', nodeid.NodeIdType.value, nodeid.NamespaceIndex, nodeid.Identifier)
    elif nodeid.NodeIdType == ua.NodeIdType.String:
        data = struct.pack('<BH', nodeid.NodeIdType.value, nodeid.NamespaceIndex) + \
            Primitives.String.pack(nodeid.Identifier)
    elif nodeid.NodeIdType == ua.NodeIdType.ByteString:
        data = struct.pack('<BH', nodeid.NodeIdType.value, nodeid.NamespaceIndex) + \
            Primitives.Bytes.pack(nodeid.Identifier)
    elif nodeid.NodeIdType == ua.NodeIdType.Guid:
        data = struct.pack('<BH', nodeid.NodeIdType.value, nodeid.NamespaceIndex) + \
               Primitives.Guid.pack(nodeid.Identifier)
    else:
        raise UaError(f'Unknown NodeIdType: {nodeid.NodeIdType} for NodeId: {nodeid}')
    # Add NamespaceUri and ServerIndex in case we have an ExpandedNodeId
    if nodeid.NamespaceUri:
        data = bytearray(data)
        data[0] = set_bit(data[0], 7)
        data.extend(Primitives.String.pack(nodeid.NamespaceUri))
    if nodeid.ServerIndex:
        if not isinstance(data, bytearray):
            data = bytearray(data)
        data[0] = set_bit(data[0], 6)
        data.extend(Primitives.UInt32.pack(nodeid.ServerIndex))
    return data


def nodeid_from_binary(data):
    nid = ua.NodeId()
    encoding = ord(data.read(1))
    nid.NodeIdType = ua.NodeIdType(encoding & 0b00111111)

    if nid.NodeIdType == ua.NodeIdType.TwoByte:
        nid.Identifier = ord(data.read(1))
    elif nid.NodeIdType == ua.NodeIdType.FourByte:
        nid.NamespaceIndex, nid.Identifier = struct.unpack("<BH", data.read(3))
    elif nid.NodeIdType == ua.NodeIdType.Numeric:
        nid.NamespaceIndex, nid.Identifier = struct.unpack("<HI", data.read(6))
    elif nid.NodeIdType == ua.NodeIdType.String:
        nid.NamespaceIndex = Primitives.UInt16.unpack(data)
        nid.Identifier = Primitives.String.unpack(data)
    elif nid.NodeIdType == ua.NodeIdType.ByteString:
        nid.NamespaceIndex = Primitives.UInt16.unpack(data)
        nid.Identifier = Primitives.Bytes.unpack(data)
    elif nid.NodeIdType == ua.NodeIdType.Guid:
        nid.NamespaceIndex = Primitives.UInt16.unpack(data)
        nid.Identifier = Primitives.Guid.unpack(data)
    else:
        raise UaError(f'Unknown NodeId encoding: {nid.NodeIdType}')

    if test_bit(encoding, 7):
        nid.NamespaceUri = Primitives.String.unpack(data)
    if test_bit(encoding, 6):
        nid.ServerIndex = Primitives.UInt32.unpack(data)

    return nid


def variant_to_binary(var):
    b = []
    encoding = var.VariantType.value & 0b111111
    if var.is_array or isinstance(var.Value, (list, tuple)):
        var.is_array = True
        encoding = set_bit(encoding, 7)
        if var.Dimensions is not None:
            encoding = set_bit(encoding, 6)
        b.append(Primitives.Byte.pack(encoding))
        b.append(pack_uatype_array(var.VariantType, ua.flatten(var.Value)))
        if var.Dimensions is not None:
            b.append(pack_uatype_array(ua.VariantType.Int32, var.Dimensions))
    else:
        b.append(Primitives.Byte.pack(encoding))
        b.append(pack_uatype(var.VariantType, var.Value))

    return b"".join(b)


def variant_from_binary(data):
    dimensions = None
    array = False
    encoding = ord(data.read(1))
    int_type = encoding & 0b00111111
    vtype = ua.datatype_to_varianttype(int_type)
    if test_bit(encoding, 7):
        value = unpack_uatype_array(vtype, data)
        array = True
    else:
        value = unpack_uatype(vtype, data)
    if test_bit(encoding, 6):
        dimensions = unpack_uatype_array(ua.VariantType.Int32, data)
        value = _reshape(value, dimensions)
    return ua.Variant(value, vtype, dimensions, is_array=array)


def _reshape(flat, dims):
    subdims = dims[1:]
    subsize = 1
    for i in subdims:
        if i == 0:
            i = 1
        subsize *= i
    while dims[0] * subsize > len(flat):
        flat.append([])
    if not subdims or subdims == [0]:
        return flat
    return [_reshape(flat[i:i + subsize], subdims) for i in range(0, len(flat), subsize)]


def extensionobject_from_binary(data):
    """
    Convert binary-coded ExtensionObject to a Python object.
    Returns an object, or None if TypeId is zero
    """
    typeid = nodeid_from_binary(data)
    encoding = ord(data.read(1))
    body = None
    if encoding & (1 << 0):
        length = Primitives.Int32.unpack(data)
        if length < 1:
            body = Buffer(b"")
        else:
            body = data.copy(length)
            data.skip(length)
    if typeid.Identifier == 0:
        return None
    elif typeid in ua.extension_objects_by_typeid:
        cls = ua.extension_objects_by_typeid[typeid]
        if body is None:
            raise UaError(f'parsing ExtensionObject {cls.__name__} without data')
        return from_binary(cls, body)
    else:
        e = ua.ExtensionObject()
        e.TypeId = typeid
        e.Encoding = encoding
        if body is not None:
            e.Body = body.read(len(body))
        return e


def extensionobject_to_binary(obj):
    """
    Convert Python object to binary-coded ExtensionObject.
    If obj is None, convert to empty ExtensionObject (TypeId=0, no Body).
    Returns a binary string
    """
    if isinstance(obj, ua.ExtensionObject):
        return struct_to_binary(obj)
    if obj is None:
        type_id = ua.NodeId()
        encoding = 0
        body = None
    else:
        type_id = ua.extension_object_typeids[obj.__class__.__name__]
        encoding = 0x01
        body = struct_to_binary(obj)
    packet = [
        nodeid_to_binary(type_id),
        Primitives.Byte.pack(encoding),
    ]
    if body:
        packet.append(Primitives.Bytes.pack(body))
    return b''.join(packet)


def from_binary(uatype, data):
    """
    unpack data given an uatype as a string or a python class having a ua_types member
    """
    if isinstance(uatype, str) and uatype.startswith("ListOf"):
        utype = uatype[6:]
        if hasattr(ua.VariantType, utype):
            vtype = getattr(ua.VariantType, utype)
            return unpack_uatype_array(vtype, data)
        size = Primitives.Int32.unpack(data)
        return [from_binary(utype, data) for _ in range(size)]
    elif isinstance(uatype, str) and hasattr(ua.VariantType, uatype):
        vtype = getattr(ua.VariantType, uatype)
        return unpack_uatype(vtype, data)
    elif isinstance(uatype, str) and hasattr(Primitives, uatype):
        return getattr(Primitives, uatype).unpack(data)
    else:
        return struct_from_binary(uatype, data)


def struct_from_binary(objtype, data):
    """
    unpack an ua struct. Arguments are an objtype as Python class or string
    """
    if isinstance(objtype, str):
        objtype = getattr(ua, objtype)
    if issubclass(objtype, Enum):
        return objtype(Primitives.UInt32.unpack(data))
    obj = objtype()
    for name, uatype in obj.ua_types:
        # if our member has a switch and it is not set we skip it
        if hasattr(obj, "ua_switches") and name in obj.ua_switches:
            container_name, idx = obj.ua_switches[name]
            val = getattr(obj, container_name)
            if not test_bit(val, idx):
                continue
        val = from_binary(uatype, data)
        setattr(obj, name, val)
    return obj


def header_to_binary(hdr):
    b = [struct.pack("<3ss", hdr.MessageType, hdr.ChunkType)]
    size = hdr.body_size + 8
    if hdr.MessageType in (ua.MessageType.SecureOpen, ua.MessageType.SecureClose, ua.MessageType.SecureMessage):
        size += 4
    b.append(Primitives.UInt32.pack(size))
    if hdr.MessageType in (ua.MessageType.SecureOpen, ua.MessageType.SecureClose, ua.MessageType.SecureMessage):
        b.append(Primitives.UInt32.pack(hdr.ChannelId))
    return b"".join(b)


def header_from_binary(data):
    hdr = ua.Header()
    hdr.MessageType, hdr.ChunkType, hdr.packet_size = struct.unpack("<3scI", data.read(8))
    hdr.body_size = hdr.packet_size - 8
    if hdr.MessageType in (ua.MessageType.SecureOpen, ua.MessageType.SecureClose, ua.MessageType.SecureMessage):
        hdr.body_size -= 4
        hdr.ChannelId = Primitives.UInt32.unpack(data)
        hdr.header_size = 12
    return hdr


def uatcp_to_binary(message_type, message):
    """
    Convert OPC UA TCP message (see OPC UA specs Part 6, 7.1) to binary.
    The only supported types are Hello, Acknowledge and ErrorMessage
    """
    header = ua.Header(message_type, ua.ChunkType.Single)
    binmsg = struct_to_binary(message)
    header.body_size = len(binmsg)
    return header_to_binary(header) + binmsg


1			"""
2			Binary protocol specific functions and constants
3			"""
4
5			import struct
6			import logging
7			import uuid
8			from enum import IntEnum, Enum
9
10			from .uaerrors import UaError
11			from ..common.utils import Buffer
12			from asyncua import ua
13
14			logger = logging.getLogger('__name__')
15
16
17			def test_bit(data, offset):
18			mask = 1 << offset
19			return data & mask
20
21
22			def set_bit(data, offset):
23			mask = 1 << offset
24			return data \| mask
25
26
27			def unset_bit(data, offset):
28			mask = 1 << offset
29			return data & ~mask
30
31
32			class _DateTime(object):
33			@staticmethod
34			def pack(dt):
35			epch = ua.datetime_to_win_epoch(dt)
36			return Primitives.Int64.pack(epch)
37
38			@staticmethod
39			def unpack(data):
40			epch = Primitives.Int64.unpack(data)
41			return ua.win_epoch_to_datetime(epch)
42
43
44			class _Bytes(object):
45			@staticmethod
46			def pack(data):
47			if data is None:
48			return Primitives.Int32.pack(-1)
49			length = len(data)
50			return Primitives.Int32.pack(length) + data
51
52			@staticmethod
53			def unpack(data):
54			length = Primitives.Int32.unpack(data)
55			if length == -1:
56			return None
57			return data.read(length)
58
59
60			class _String(object):
61			@staticmethod
62			def pack(string):
63			if string is not None:
64			string = string.encode('utf-8')
65			return _Bytes.pack(string)
66
67			@staticmethod
68			def unpack(data):
69			b = _Bytes.unpack(data)
70			if b is None:
71			return b
72			return b.decode('utf-8')
73
74
75			class _Null(object):
76			@staticmethod
77			def pack(data):
78			return b''
79
80			@staticmethod
81			def unpack(data):
82			return None
83
84
85			class _Guid(object):
86			@staticmethod
87			def pack(guid):
88			# convert python UUID 6 field format to OPC UA 4 field format
89			f1 = Primitives.UInt32.pack(guid.time_low)
90			f2 = Primitives.UInt16.pack(guid.time_mid)
91			f3 = Primitives.UInt16.pack(guid.time_hi_version)
92			f4a = Primitives.Byte.pack(guid.clock_seq_hi_variant)
93			f4b = Primitives.Byte.pack(guid.clock_seq_low)
94			f4c = struct.pack('>Q', guid.node)[2:8] # no primitive .pack available for 6 byte int
95			f4 = f4a + f4b + f4c
96			# concat byte fields
97			b = f1 + f2 + f3 + f4
98
99			return b
100
101			@staticmethod
102			def unpack(data):
103			# convert OPC UA 4 field format to python UUID bytes
104			f1 = struct.pack('>I', Primitives.UInt32.unpack(data))
105			f2 = struct.pack('>H', Primitives.UInt16.unpack(data))
106			f3 = struct.pack('>H', Primitives.UInt16.unpack(data))
107			f4 = data.read(8)
108			# concat byte fields
109			b = f1 + f2 + f3 + f4
110
111			return uuid.UUID(bytes=b)
112
113
114			class _Primitive1(object):
115			def __init__(self, fmt):
116			self._fmt = fmt
117			st = struct.Struct(fmt.format(1))
118			self.size = st.size
119			self.format = st.format
120
121			def pack(self, data):
122			return struct.pack(self.format, data)
123
124			def unpack(self, data):
125			return struct.unpack(self.format, data.read(self.size))[0]
126
127			def pack_array(self, data):
128			if data is None:
129			return Primitives.Int32.pack(-1)
130			if not isinstance(data, list):
131			logger.warning(f'ua_binary.py > _Primitive1 > pack_array > data: {data} is not a instance of "list"!')
132			return Primitives.Int32.pack(-1) # to prevent crashing while runtime
133			size_data = Primitives.Int32.pack(len(data))
134			return size_data + struct.pack(self._fmt.format(len(data)), *data)
135
136			def unpack_array(self, data, length):
137			if length == -1:
138			return None
139			if length == 0:
140			return ()
141			return struct.unpack(self._fmt.format(length), data.read(self.size * length))
142
143
144			class Primitives1(object):
145			SByte = _Primitive1('<{:d}b')
146			Int16 = _Primitive1('<{:d}h')
147			Int32 = _Primitive1('<{:d}i')
148			Int64 = _Primitive1('<{:d}q')
149			Byte = _Primitive1('<{:d}B')
150			Char = Byte
151			UInt16 = _Primitive1('<{:d}H')
152			UInt32 = _Primitive1('<{:d}I')
153			UInt64 = _Primitive1('<{:d}Q')
154			Boolean = _Primitive1('<{:d}?')
155			Double = _Primitive1('<{:d}d')
156			Float = _Primitive1('<{:d}f')
157
158
159			class Primitives(Primitives1):
160			Null = _Null()
161			String = _String()
162			Bytes = _Bytes()
163			ByteString = _Bytes()
164			CharArray = _String()
165			DateTime = _DateTime()
166			Guid = _Guid()
167
168
169			def pack_uatype(vtype, value):
170			if hasattr(Primitives, vtype.name):
171			return getattr(Primitives, vtype.name).pack(value)
172			elif vtype.value > 25:
173			return Primitives.Bytes.pack(value)
174			elif vtype == ua.VariantType.ExtensionObject:
175			return extensionobject_to_binary(value)
176			elif vtype in (ua.VariantType.NodeId, ua.VariantType.ExpandedNodeId):
177			return nodeid_to_binary(value)
178			elif vtype == ua.VariantType.Variant:
179			return variant_to_binary(value)
180			else:
181			return struct_to_binary(value)
182
183
184			def unpack_uatype(vtype, data):
185			if hasattr(Primitives, vtype.name):
186			st = getattr(Primitives, vtype.name)
187			return st.unpack(data)
188			elif vtype.value > 25:
189			return Primitives.Bytes.unpack(data)
190			elif vtype == ua.VariantType.ExtensionObject:
191			return extensionobject_from_binary(data)
192			elif vtype in (ua.VariantType.NodeId, ua.VariantType.ExpandedNodeId):
193			return nodeid_from_binary(data)
194			elif vtype == ua.VariantType.Variant:
195			return variant_from_binary(data)
196			else:
197			if hasattr(ua, vtype.name):
198			cls = getattr(ua, vtype.name)
199			return struct_from_binary(cls, data)
200			else:
201			raise UaError(f'Cannot unpack unknown variant type {vtype}')
202
203
204			def pack_uatype_array(vtype, array):
205			if hasattr(Primitives1, vtype.name):
206			data_type = getattr(Primitives1, vtype.name)
207			return data_type.pack_array(array)
208			if array is None:
209			return b'\xff\xff\xff\xff'
210			length = len(array)
211			b = [pack_uatype(vtype, val) for val in array]
212			b.insert(0, Primitives.Int32.pack(length))
213			return b"".join(b)
214
215
216			def unpack_uatype_array(vtype, data):
217			length = Primitives.Int32.unpack(data)
218			if length == -1:
219			return None
220			elif hasattr(Primitives1, vtype.name):
221			data_type = getattr(Primitives1, vtype.name)
222			# Remark: works without tuple conversion to list.
223			return list(data_type.unpack_array(data, length))
224			else:
225			# Revert to slow serial unpacking.
226			return [unpack_uatype(vtype, data) for _ in range(length)]
227
228
229			def struct_to_binary(obj):
230			packet = []
231			has_switch = hasattr(obj, 'ua_switches')
232			if has_switch:
233			for name, switch in obj.ua_switches.items():
234			member = getattr(obj, name)
235			container_name, idx = switch
236			if member is not None:
237			container_val = getattr(obj, container_name)
238			container_val = container_val \| 1 << idx
239			setattr(obj, container_name, container_val)
240			for name, uatype in obj.ua_types:
241			val = getattr(obj, name)
242			if uatype.startswith('ListOf'):
243			packet.append(list_to_binary(uatype[6:], val))
244			else:
245			if has_switch and val is None and name in obj.ua_switches:
246			pass
247			else:
248			packet.append(to_binary(uatype, val))
249			return b''.join(packet)
250
251
252			def to_binary(uatype, val):
253			"""
254			Pack a python object to binary given a string defining its type
255			"""
256			if uatype.startswith('ListOf'):
257			# if isinstance(val, (list, tuple)):
258			return list_to_binary(uatype[6:], val)
259			elif type(uatype) is str and hasattr(ua.VariantType, uatype):
260			vtype = getattr(ua.VariantType, uatype)
261			return pack_uatype(vtype, val)
262			elif type(uatype) is str and hasattr(Primitives, uatype):
263			return getattr(Primitives, uatype).pack(val)
264			elif isinstance(val, (IntEnum, Enum)):
265			return Primitives.UInt32.pack(val.value)
266			elif isinstance(val, ua.NodeId):
267			return nodeid_to_binary(val)
268			elif isinstance(val, ua.Variant):
269			return variant_to_binary(val)
270			elif hasattr(val, 'ua_types'):
271			return struct_to_binary(val)
272			else:
273			raise UaError(f'No known way to pack {val} of type {uatype} to ua binary')
274
275
276			def list_to_binary(uatype, val):
277			if val is None:
278			return Primitives.Int32.pack(-1)
279			if hasattr(Primitives1, uatype):
280			data_type = getattr(Primitives1, uatype)
281			return data_type.pack_array(val)
282			data_size = Primitives.Int32.pack(len(val))
283			pack = [to_binary(uatype, el) for el in val]
284			pack.insert(0, data_size)
285			return b''.join(pack)
286
287
288			def nodeid_to_binary(nodeid):
289			if nodeid.NodeIdType == ua.NodeIdType.TwoByte:
290			return struct.pack('<BB', nodeid.NodeIdType.value, nodeid.Identifier)
291			elif nodeid.NodeIdType == ua.NodeIdType.FourByte:
292			return struct.pack('<BBH', nodeid.NodeIdType.value, nodeid.NamespaceIndex, nodeid.Identifier)
293			elif nodeid.NodeIdType == ua.NodeIdType.Numeric:
294			data = struct.pack('<BHI', nodeid.NodeIdType.value, nodeid.NamespaceIndex, nodeid.Identifier)
295			elif nodeid.NodeIdType == ua.NodeIdType.String:
296			data = struct.pack('<BH', nodeid.NodeIdType.value, nodeid.NamespaceIndex) + \
297			Primitives.String.pack(nodeid.Identifier)
298			elif nodeid.NodeIdType == ua.NodeIdType.ByteString:
299			data = struct.pack('<BH', nodeid.NodeIdType.value, nodeid.NamespaceIndex) + \
300			Primitives.Bytes.pack(nodeid.Identifier)
301			elif nodeid.NodeIdType == ua.NodeIdType.Guid:
302			data = struct.pack('<BH', nodeid.NodeIdType.value, nodeid.NamespaceIndex) + \
303			Primitives.Guid.pack(nodeid.Identifier)
304			else:
305			raise UaError(f'Unknown NodeIdType: {nodeid.NodeIdType} for NodeId: {nodeid}')
306			# Add NamespaceUri and ServerIndex in case we have an ExpandedNodeId
307			if nodeid.NamespaceUri:
308			data = bytearray(data)
309			data[0] = set_bit(data[0], 7)
310			data.extend(Primitives.String.pack(nodeid.NamespaceUri))
311			if nodeid.ServerIndex:
312			if not isinstance(data, bytearray):
313			data = bytearray(data)
314			data[0] = set_bit(data[0], 6)
315			data.extend(Primitives.UInt32.pack(nodeid.ServerIndex))
316			return data
317
318
319			def nodeid_from_binary(data):
320			nid = ua.NodeId()
321			encoding = ord(data.read(1))
322			nid.NodeIdType = ua.NodeIdType(encoding & 0b00111111)
323
324			if nid.NodeIdType == ua.NodeIdType.TwoByte:
325			nid.Identifier = ord(data.read(1))
326			elif nid.NodeIdType == ua.NodeIdType.FourByte:
327			nid.NamespaceIndex, nid.Identifier = struct.unpack("<BH", data.read(3))
328			elif nid.NodeIdType == ua.NodeIdType.Numeric:
329			nid.NamespaceIndex, nid.Identifier = struct.unpack("<HI", data.read(6))
330			elif nid.NodeIdType == ua.NodeIdType.String:
331			nid.NamespaceIndex = Primitives.UInt16.unpack(data)
332			nid.Identifier = Primitives.String.unpack(data)
333			elif nid.NodeIdType == ua.NodeIdType.ByteString:
334			nid.NamespaceIndex = Primitives.UInt16.unpack(data)
335			nid.Identifier = Primitives.Bytes.unpack(data)
336			elif nid.NodeIdType == ua.NodeIdType.Guid:
337			nid.NamespaceIndex = Primitives.UInt16.unpack(data)
338			nid.Identifier = Primitives.Guid.unpack(data)
339			else:
340			raise UaError(f'Unknown NodeId encoding: {nid.NodeIdType}')
341
342			if test_bit(encoding, 7):
343			nid.NamespaceUri = Primitives.String.unpack(data)
344			if test_bit(encoding, 6):
345			nid.ServerIndex = Primitives.UInt32.unpack(data)
346
347			return nid
348
349
350			def variant_to_binary(var):
351			b = []
352			encoding = var.VariantType.value & 0b111111
353			if var.is_array or isinstance(var.Value, (list, tuple)):
354			var.is_array = True
355			encoding = set_bit(encoding, 7)
356			if var.Dimensions is not None:
357			encoding = set_bit(encoding, 6)
358			b.append(Primitives.Byte.pack(encoding))
359			b.append(pack_uatype_array(var.VariantType, ua.flatten(var.Value)))
360			if var.Dimensions is not None:
361			b.append(pack_uatype_array(ua.VariantType.Int32, var.Dimensions))
362			else:
363			b.append(Primitives.Byte.pack(encoding))
364			b.append(pack_uatype(var.VariantType, var.Value))
365
366			return b"".join(b)
367
368
369			def variant_from_binary(data):
370			dimensions = None
371			array = False
372			encoding = ord(data.read(1))
373			int_type = encoding & 0b00111111
374			vtype = ua.datatype_to_varianttype(int_type)
375			if test_bit(encoding, 7):
376			value = unpack_uatype_array(vtype, data)
377			array = True
378			else:
379			value = unpack_uatype(vtype, data)
380			if test_bit(encoding, 6):
381			dimensions = unpack_uatype_array(ua.VariantType.Int32, data)
382			value = _reshape(value, dimensions)
383			return ua.Variant(value, vtype, dimensions, is_array=array)
384
385
386			def _reshape(flat, dims):
387			subdims = dims[1:]
388			subsize = 1
389			for i in subdims:
390			if i == 0:
391			i = 1
392			subsize *= i
393			while dims[0] * subsize > len(flat):
394			flat.append([])
395			if not subdims or subdims == [0]:
396			return flat
397			return [_reshape(flat[i:i + subsize], subdims) for i in range(0, len(flat), subsize)]
398
399
400			def extensionobject_from_binary(data):
401			"""
402			Convert binary-coded ExtensionObject to a Python object.
403			Returns an object, or None if TypeId is zero
404			"""
405			typeid = nodeid_from_binary(data)
406			encoding = ord(data.read(1))
407			body = None
408			if encoding & (1 << 0):
409			length = Primitives.Int32.unpack(data)
410			if length < 1:
411			body = Buffer(b"")
412			else:
413			body = data.copy(length)
414			data.skip(length)
415			if typeid.Identifier == 0:
416			return None
417			elif typeid in ua.extension_objects_by_typeid:
418			cls = ua.extension_objects_by_typeid[typeid]
419			if body is None:
420			raise UaError(f'parsing ExtensionObject {cls.__name__} without data')
421			return from_binary(cls, body)
422			else:
423			e = ua.ExtensionObject()
424			e.TypeId = typeid
425			e.Encoding = encoding
426			if body is not None:
427			e.Body = body.read(len(body))
428			return e
429
430
431			def extensionobject_to_binary(obj):
432			"""
433			Convert Python object to binary-coded ExtensionObject.
434			If obj is None, convert to empty ExtensionObject (TypeId=0, no Body).
435			Returns a binary string
436			"""
437			if isinstance(obj, ua.ExtensionObject):
438			return struct_to_binary(obj)
439			if obj is None:
440			type_id = ua.NodeId()
441			encoding = 0
442			body = None
443			else:
444			type_id = ua.extension_object_typeids[obj.__class__.__name__]
445			encoding = 0x01
446			body = struct_to_binary(obj)
447			packet = [
448			nodeid_to_binary(type_id),
449			Primitives.Byte.pack(encoding),
450			]
451			if body:
452			packet.append(Primitives.Bytes.pack(body))
453			return b''.join(packet)
454
455
456			def from_binary(uatype, data):
457			"""
458			unpack data given an uatype as a string or a python class having a ua_types member
459			"""
460			if isinstance(uatype, str) and uatype.startswith("ListOf"):
461			utype = uatype[6:]
462			if hasattr(ua.VariantType, utype):
463			vtype = getattr(ua.VariantType, utype)
464			return unpack_uatype_array(vtype, data)
465			size = Primitives.Int32.unpack(data)
466			return [from_binary(utype, data) for _ in range(size)]
467			elif isinstance(uatype, str) and hasattr(ua.VariantType, uatype):
468			vtype = getattr(ua.VariantType, uatype)
469			return unpack_uatype(vtype, data)
470			elif isinstance(uatype, str) and hasattr(Primitives, uatype):
471			return getattr(Primitives, uatype).unpack(data)
472			else:
473			return struct_from_binary(uatype, data)
474
475
476			def struct_from_binary(objtype, data):
477			"""
478			unpack an ua struct. Arguments are an objtype as Python class or string
479			"""
480			if isinstance(objtype, str):
481			objtype = getattr(ua, objtype)
482			if issubclass(objtype, Enum):
483			return objtype(Primitives.UInt32.unpack(data))
484			obj = objtype()
485			for name, uatype in obj.ua_types:
486			# if our member has a switch and it is not set we skip it
487			if hasattr(obj, "ua_switches") and name in obj.ua_switches:
488			container_name, idx = obj.ua_switches[name]
489			val = getattr(obj, container_name)
490			if not test_bit(val, idx):
491			continue
492			val = from_binary(uatype, data)
493			setattr(obj, name, val)
494			return obj
495
496
497			def header_to_binary(hdr):
498			b = [struct.pack("<3ss", hdr.MessageType, hdr.ChunkType)]
499			size = hdr.body_size + 8
500			if hdr.MessageType in (ua.MessageType.SecureOpen, ua.MessageType.SecureClose, ua.MessageType.SecureMessage):
501			size += 4
502			b.append(Primitives.UInt32.pack(size))
503			if hdr.MessageType in (ua.MessageType.SecureOpen, ua.MessageType.SecureClose, ua.MessageType.SecureMessage):
504			b.append(Primitives.UInt32.pack(hdr.ChannelId))
505			return b"".join(b)
506
507
508			def header_from_binary(data):
509			hdr = ua.Header()
510			hdr.MessageType, hdr.ChunkType, hdr.packet_size = struct.unpack("<3scI", data.read(8))
511			hdr.body_size = hdr.packet_size - 8
512			if hdr.MessageType in (ua.MessageType.SecureOpen, ua.MessageType.SecureClose, ua.MessageType.SecureMessage):
513			hdr.body_size -= 4
514			hdr.ChannelId = Primitives.UInt32.unpack(data)
515			hdr.header_size = 12
516			return hdr
517
518
519			def uatcp_to_binary(message_type, message):
520			"""
521			Convert OPC UA TCP message (see OPC UA specs Part 6, 7.1) to binary.
522			The only supported types are Hello, Acknowledge and ErrorMessage
523			"""
524			header = ua.Header(message_type, ua.ChunkType.Single)
525			binmsg = struct_to_binary(message)
526			header.body_size = len(binmsg)
527			return header_to_binary(header) + binmsg
528

FreeOpcUa / opcua-asyncio

asyncua.ua.ua_binary.extensionobject_to_binary() A last analyzed 2020-12-22 17:52 UTC

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asyncua.ua.ua_binary.extensionobject_to_binary() A
last analyzed 2020-12-22 17:52 UTC