def _active_get_mapping(self):
# Anly working on A record now
if ((self._active_timer != None) and
(self._active_timer.is_alive())):
return
try:
results = resolver.query(self.rule, 'A')
ttl = results.ttl
self._active_timer = Timer(ttl, self._active_get_mapping_expired)
self._active_timer.start()
new_active_results = []
# These two reduce churn: only adds things that weren't there from the
# previous pass, only deletes things that aren't there from this pass.
# Add new addresses
for addr in results:
new_active_results.append(addr)
if addr not in self._active_results:
print "adding addr: " + str(addr)
self.add_rule_cb(ipv4_src=str(addr), eth_type=ether.ETH_TYPE_IP)
self.add_rule_cb(ipv4_dst=str(addr), eth_type=ether.ETH_TYPE_IP)
# Remove old addresses
for addr in self._active_results:
if addr not in results:
self.remove_rule_cb(ipv4_src=str(addr), eth_type=ether.ETH_TYPE_IP)
self.remove_rule_cb(ipv4_dst=str(addr), eth_type=ether.ETH_TYPE_IP)
self._active_results = new_active_results
except (resolver.NoAnswer, exception.Timeout, resolver.NXDOMAIN):
self.logger.info("Could not query for " + self.rule + ". Trying again in 30 seconds.")
self._active_timer = Timer(30, self._active_get_mapping_expired)
self._active_timer.start()
self._active_results = []
class DNSMetadataEntry(MetadataEntry):
def __init__(self, data_source, engine, rule, add_rule_cb, remove_rule_cb):
super(DNSMetadataEntry, self).__init__(data_source, engine, rule)
self.register_callbacks(add_rule_cb, remove_rule_cb)
self.data_source.set_new_callback(self.handle_new_entry_callback)
if ACTIVE_MAPPING == True:
self._active_timer = None
self._active_results = []
self._active_get_mapping()
def handle_expiration_callback(self, addr, entry):
self.logger.info("DNSMetadataEntry.handle_expiration_callback(): called with " + addr)
#need to remove the rules that was generated by the particular DNSEntry
#TODO
self.remove_rule_cb(ipv4_src=str(addr), eth_type=ether.ETH_TYPE_IP)
self.remove_rule_cb(ipv4_dst=str(addr), eth_type=ether.ETH_TYPE_IP)
def handle_new_entry_callback(self, addr, entry):
self.logger.info("DNSMetadataEntry.handle_new_entry_callback(): called with " + addr)
for name in entry.names:
if name == self.rule:
self.add_rule_cb(ipv4_src=str(addr), eth_type=ether.ETH_TYPE_IP)
self.add_rule_cb(ipv4_dst=str(addr), eth_type=ether.ETH_TYPE_IP)
self.logger.debug(" New rule for " + name)
entry.register_timeout_callback(self.handle_expiration_callback)
def _active_get_mapping_expired(self):
#self.logger.debug("_active_get_mapping_expired() called " + str(self._active_timer.is_alive()))
self._active_timer.cancel()
self._active_get_mapping()
def _active_get_mapping(self):
# Anly working on A record now
if ((self._active_timer != None) and
(self._active_timer.is_alive())):
return
try:
results = resolver.query(self.rule, 'A')
ttl = results.ttl
self._active_timer = Timer(ttl, self._active_get_mapping_expired)
self._active_timer.start()
new_active_results = []
# These two reduce churn: only adds things that weren't there from the
# previous pass, only deletes things that aren't there from this pass.
# Add new addresses
for addr in results:
new_active_results.append(addr)
if addr not in self._active_results:
print "adding addr: " + str(addr)
self.add_rule_cb(ipv4_src=str(addr), eth_type=ether.ETH_TYPE_IP)
self.add_rule_cb(ipv4_dst=str(addr), eth_type=ether.ETH_TYPE_IP)
# Remove old addresses
for addr in self._active_results:
if addr not in results:
self.remove_rule_cb(ipv4_src=str(addr), eth_type=ether.ETH_TYPE_IP)
self.remove_rule_cb(ipv4_dst=str(addr), eth_type=ether.ETH_TYPE_IP)
self._active_results = new_active_results
except (resolver.NoAnswer, exception.Timeout, resolver.NXDOMAIN):
self.logger.info("Could not query for " + self.rule + ". Trying again in 30 seconds.")
self._active_timer = Timer(30, self._active_get_mapping_expired)
self._active_timer.start()
self._active_results = []
def _set_and_start_timer(self):
time_to_go = self.expiry - datetime.now()
self.timer = Timer(time_to_go.total_seconds(), self._call_callbacks)
self.timer.start()
class DNSClassifierEntry:
def __init__(self, IP, names, classification, ttl, expiry=None):
self.IP = IP
self.names = names
self.classification = classification
self.ttl = ttl
if expiry is datetime:
self.expiry = expiry
else:
self.expiry = datetime.now() + timedelta(seconds=ttl)
# callbacks!
self.timeout_callbacks = []
self.timer = None
def __del__(self):
if self.timer is not None:
self.timer.cancel()
def print_entry(self, offset=""):
names_str = ""
for name in self.names:
names_str = names_str + name + " "
if (self.is_expired()):
expired = "Expired"
else:
expired = "Not expired"
print offset + self.IP
print offset + names_str
print offset + str(self.ttl)
print offset + self.classification
print offset + str(self.expiry)
print offset + expired
def is_expired(self, expiry=None):
if expiry is datetime:
expiration_time = expiry
else:
expiration_time = datetime.now()
return self.expiry < expiration_time
def update_expiry(self, ttl):
self.ttl = ttl
self.expiry = datetime.now() + timedelta(seconds=ttl)
if self.timer is not None:
self.timer.cancel()
self._set_and_start_timer()
def register_timeout_callback(self, func):
if func not in self.timeout_callbacks:
self.timeout_callbacks.append(func)
if self.timer is None and not self.is_expired():
self._set_and_start_timer()
def _call_callbacks(self):
# This is called when it expires.
for cb in self.timeout_callbacks:
cb(self.IP, self)
def _set_and_start_timer(self):
time_to_go = self.expiry - datetime.now()
self.timer = Timer(time_to_go.total_seconds(), self._call_callbacks)
self.timer.start()
