Two bug fixes

[tobiasfunke1]

Hi,

first of all thank you for this great tool! I used it in one of my projects and it helps me to find a bug in a BLE smart lock.

While using your tool as a library and wrapping it with my code, I found two small bugs:

1. missing method argument
2. missing slice boundary

The first can be validated by looking at the implementation of ConnectionSniffer. In the method on_packet_received the method on_connection is called with a given timeout (packet.timeout):

btlejack/btlejack/supervisors.py

Lines 501 to 511 in c487859

	self.access_address = packet.access_address
	self.on_connection(
	packet.inita,
	packet.adva,
	packet.crc_init,
	packet.hop_interval,
	packet.hop_increment,
	packet.channel_map,
	packet.timeout
	)
	self.state = self.STATE_FOLLOWING

I know the on_connection function is a placeholder and should be overridden like in CLIConnectionSniffer anyway, but I think the interface should be the same. So I would add the timeout argument here:

btlejack/btlejack/supervisors.py

Lines 528 to 530 in c487859

	def on_connection(self, inita, adva, crc_init, interval, increment, channel_map):
	print('Got connection !')

The second is an error during unpacking. Unpacking with unpack('<H', raw[1:])[0] of more than 2 bytes leads to struct.error: unpack requires a buffer of 2 bytes:

btlejack/btlejack/dissect/att.py

Lines 205 to 210 in c487859

	@staticmethod
	def from_bytes(raw):
	handle = unpack('<H', raw[1:])[0]
	value = raw[3:]
	return WriteRequest(handle, value)

For the WriteCommand it was sliced correctly:

btlejack/btlejack/dissect/att.py

Lines 221 to 226 in c487859

	@staticmethod
	def from_bytes(raw):
	handle = unpack('<H', raw[1:3])[0]
	value = raw[3:]
	return WriteRequest(handle, value)

I assume that this behavior also occurs with other from_bytes implementations in the same module like ExchangeMtuResponse, ExchangeMtuRequest and ErrorResponse, but I am not 100% sure. Maybe some can confirm that?