def parse_ipv4_range(range_str):
# 1.2.3.4 - 5.6.7.8
if range_str.count(".") == 6 and range_str.count("-") == 1:
start_ip_str, end_ip_str = map(lambda s: s.strip(), range_str.split("-", 1))
start_ip = IPv4.from_str(start_ip_str)
end_ip = IPv4.from_str(end_ip_str)
high_ip = IPv4(int(end_ip) - int(start_ip))
return AddressRange(start_ip, high_ip)
if range_str.count(".") == 3:
start_ip = IPv4(0)
high_ip = IPv4(0)
range_str_list = range_str.split(".", 3)
for i in xrange(len(range_str_list)):
if not range_str_list[i].count("-"):
start_ip[i] = high_ip[i] = int(range_str_list[i])
else:
start_no, end_no = range_str_list[i].split("-",1)
start_ip[i], high_ip[i] = map(int, (start_no, end_no))
return AddressRange(start_ip, high_ip)
def parse_dhcp_option(option_name, _value):
option_name = dhcp_option_name_by_alias.get(option_name, option_name)
option_type = dhcp_option_type_by_name.get(option_name, OPTION_TYPE_STRING)
if option_type == OPTION_TYPE_IP:
value = list(IPv4.from_str(_value))
elif option_type == OPTION_TYPE_MULTIPLE_IP:
byte_list = list()
for ip_str in shlex.split(_value):
ipv4 = IPv4.from_str(ip_str)
byte_list.extend(ipv4)
value = byte_list
elif option_type == OPTION_TYPE_MAC:
value = list(MAC(_value))
elif option_type == OPTION_TYPE_STRING:
value = list(ByteObject.from_ascii(_value))
elif option_type == OPTION_TYPE_INT:
value = list(ByteObject(4, _value))
else:
raise Exception("UNKNOWN OPTION TYPE")
return (option_name, value)
def HandleDhcpInform(self, packet):
mac = MAC.from_list(packet.GetHardwareAddress())
logging.debug("GOT: INFORM from " + str(mac))
entry_options = self._calculate_entry_options(str(mac))
ipv4_range_collection = self._get_ipv4_range_collection(entry_options)
self._set_packet_options(packet, entry_options)
client_lease = self.ip_lease_manager.get_lease(mac=mac)
if not client_lease:
return None
ip = IPv4.from_str(client_lease.ip_str)
packet.SetOption('yiaddr', list(ip))
packet.TransformToDhcpAckPacket()
dest_relay_or_gateway = None
if sum(packet.GetOption('giaddr')):
dest_relay_or_gateway = str(IP.from_list(packet.GetOption('giaddr')))
else:
dest_relay_or_gateway = "255.255.255.255"
logging.debug("SENT: ACK")
self.SendDhcpPacketTo(packet, dest_relay_or_gateway, 68)
def HandleDhcpDiscover(self, packet):
mac = MAC.from_list(packet.GetHardwareAddress())
logging.debug("DISCOVER: %s", str(mac))
entry_options = self._calculate_entry_options(str(mac))
ipv4_range_collection = self._get_ipv4_range_collection(entry_options)
self._set_packet_options(packet, entry_options)
backend_ip = entry_options.get('yiaddr', None)
requested_ip = self._get_requested_ip_from_packet(packet)
ip = None
if backend_ip:
ip = IPv4.from_list(backend_ip)
self.ip_lease_manager.reallocate_ip_address(ip)
logging.debug("DISCOVER: %s gets static ip: %s", str(mac), str(ip))
else:
ip = self.ip_lease_manager.allocate_ip_address(ipv4_range_collection, mac, requested_ip=requested_ip)
logging.debug("DISCOVER: %s requested ip %s, giving %s", str(mac), str(requested_ip), str(ip))
packet.SetOption('yiaddr', list(ip))
packet.TransformToDhcpOfferPacket()
logging.debug("DISCOVER: Sent OFFER to %s", str(mac))
self.SendDhcpPacketTo(packet, "255.255.255.255", 68)
def allocate_ip_address(self, address_range_collection, mac, requested_ip=None, use_existing_if_able=True):
"""
"""
ip = None
old_lease_ip = None
old_mac_lease = self.get_lease(mac=mac)
if old_mac_lease:
old_lease_ip = IPv4.from_str(old_mac_lease.ip_str)
# If the host requested a specific IP and it is available and within the network range,
# allow it
if requested_ip and requested_ip in address_range_collection and \
(not self._is_active_lease(requested_ip) or self.was_last_leased_to(requested_ip, mac)):
ip = requested_ip
# If this MAC had a lease, and the lease is allowed within the given range, give that ip
elif use_existing_if_able and old_lease_ip and old_lease_ip in address_range_collection:
ip = old_lease_ip
# If all else fails, allocate a new IP
else:
ip = self._find_available_ip(address_range_collection,)
# We temporarily lease the IP, so we're sure not to give it to anyone else
self._lease_ip_address(ip, mac, self.wait_ack_lease_time)
return ip
def _get_requested_ip_from_packet(self, packet):
for attr in ('ciaddr', 'request_ip_address'):
if sum(packet.GetOption(attr)):
requested_ip = IPv4.from_list(packet.GetOption(attr))
return requested_ip
return None
