class Node(Listener):
"""
:param :class:`can.Bus` bus:
Bus that the node is on
:param int address:
Address of the node
"""
def __init__(self, bus, address):
self.bus = bus
self.id_table = IDTable()
self.address = address
self.key = self.generate_key()
def generate_key(self):
"""
This should be randomly generated, but I don't have time to implement key exchange;
it is simply be a hash of the address for now.
"""
addr = str(self.address)
h = SHA.new()
h.update(b''+addr)
return h
def on_message_received(self, msg):
m = msg.MACs[:2]
m = [str(hex(x)) for x in m]
string_mac = ""
for x in m:
to_add = x[-2:]
if 'x' in to_add:
to_add = '0' + to_add[1:]
string_mac += to_add
h = HMAC.new(b''+self.key.hexdigest(), msg.binary_data_string).hexdigest()[-4:]
log.debug("MACs at receiving node: %s", string_mac)
log.debug("MACs computed at node: %s", h)
if string_mac == h:
msg_entry = self.id_table.get_entry(msg.source, msg.destinations)
if not msg_entry:
count_at_node = 0
else:
count_at_node = msg_entry['count']
log.debug("source: %d, destination: %d", msg.source, msg.destinations[0])
log.debug("count at node: %d, count from msg: %d", count_at_node, msg.data[5])
if count_at_node <= msg.data[5]:
msg.accepted = True
self.id_table.set_count(msg.source, msg.destinations, msg.data[5])
def __init__(self, bus, address):
self.bus = bus
self.id_table = IDTable()
self.address = address
self.key = self.generate_key()
def __init__(self, bus, address):
self.bus = bus
self.id_table = IDTable()
self.address = address
self.key = self.generate_key()
