def write(self, string):
"""
Write given bytes string to socket. Loop as long as every byte in
string is written unless exception is raised.
"""
try:
self.sock.sendall(string)
except SOCKET_TIMEOUT as error:
raise ConnectionError('Socket timed out. ' + str(error))
except SOCKET_ERROR as error:
raise ConnectionError('Failed to write to socket. ' + str(error))
def read(self, length):
"""
Read as many bytes from socket as specified in length.
Loop as long as every byte is read unless exception is raised.
"""
try:
data = self.sock.recv(length)
if not data:
raise ConnectionError('Connection unexpectedly closed.')
return data
except SOCKET_TIMEOUT as error:
raise ConnectionError('Socket timed out. ' + str(error))
except SOCKET_ERROR as error:
raise ConnectionError('Failed to read from socket. ' + str(error))
def decodeLength(length):
"""
Decode length based on given bytes.
:param length: Bytes string to decode.
:return: Decoded length.
"""
bytes_length = len(length)
if bytes_length < 2:
offset = b'\x00\x00\x00'
XOR = 0
elif bytes_length < 3:
offset = b'\x00\x00'
XOR = 0x8000
elif bytes_length < 4:
offset = b'\x00'
XOR = 0xC00000
elif bytes_length < 5:
offset = b''
XOR = 0xE0000000
else:
raise ConnectionError('Unable to decode length of {}'.format(length))
decoded = unpack('!I', (offset + length))[0]
decoded ^= XOR
return decoded
def create_transport(host, **kwargs):
try:
sock = create_connection((host, kwargs['port']), kwargs['timeout'],
(kwargs['saddr'], 0))
except (SOCKET_ERROR, SOCKET_TIMEOUT) as error:
raise ConnectionError(error)
return SocketTransport(sock=sock)
def read(self, length):
"""
Read as many bytes from socket as specified in length.
Loop as long as every byte is read unless exception is raised.
"""
data = bytearray()
while len(data) != length:
data += self.sock.recv((length - len(data)))
if not data:
raise ConnectionError('Connection unexpectedly closed.')
return data
def read(self, length):
"""
Read as many bytes from socket as specified in length.
Loop as long as every byte is read unless exception is raised.
"""
try:
data = b''
while len(data) < length:
rlist, wlist, xlist = select.select([self.sock], [],
[self.sock], 5)
if rlist:
data += self.sock.recv(length - len(data))
elif xlist:
raise ConnectionError('Connection unexpectedly closed.')
else:
raise ConnectionError('Connection read timeout.')
return data
except SOCKET_TIMEOUT as error:
raise ConnectionError('Socket timed out. ' + str(error))
except SOCKET_ERROR as error:
raise ConnectionError('Failed to read from socket. ' + str(error))
def determineLength(length):
"""
Given first read byte, determine how many more bytes
needs to be known in order to get fully encoded length.
:param length: First read byte.
:return: How many bytes to read.
"""
integer = ord(length)
if integer < 128:
return 0
elif integer < 192:
return 1
elif integer < 224:
return 2
elif integer < 240:
return 3
else:
raise ConnectionError('Unknown controll byte {}'.format(length))
def encodeLength(length):
"""
Encode given length in mikrotik format.
:param length: Integer < 268435456.
:returns: Encoded length.
"""
if length < 128:
ored_length = length
offset = -1
elif length < 16384:
ored_length = length | 0x8000
offset = -2
elif length < 2097152:
ored_length = length | 0xC00000
offset = -3
elif length < 268435456:
ored_length = length | 0xE0000000
offset = -4
else:
raise ConnectionError('Unable to encode length of {}'.format(length))
return pack('!I', ored_length)[offset:]