def handle_dhcp_discover(self, dhcp_pkt, datapath, port):
try:
# Choose a IP form IP pool list
client_ip_addr = str(self.ip_pool_list.pop())
self.mac_to_client_ip[dhcp_pkt.chaddr] = client_ip_addr
except IndexError:
self.logger.info("EMPTY IP POOL")
return
# send dhcp_offer message.
dhcp_offer_msg_type = '\x02'
self.logger.info("Send DHCP message type %s" %
(self.dhcp_msg_type_code[ord(dhcp_offer_msg_type)]))
msg_option = dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
value=dhcp_offer_msg_type)
options = dhcp.options(option_list=[msg_option])
hlen = len(addrconv.mac.text_to_bin(dhcp_pkt.chaddr))
dhcp_pkt = dhcp.dhcp(hlen=hlen,
op=dhcp.DHCP_BOOT_REPLY,
chaddr=dhcp_pkt.chaddr,
yiaddr=client_ip_addr,
giaddr=dhcp_pkt.giaddr,
xid=dhcp_pkt.xid,
options=options)
self._send_dhcp_packet(datapath, dhcp_pkt, port)
def handle_dhcp_discover(self, dhcp_pkt, datapath, port):
try:
# Choose a IP form IP pool list
client_ip_addr = str(self.ip_pool_list.pop())
self.mac_to_client_ip[dhcp_pkt.chaddr] = client_ip_addr
except IndexError:
self.logger.info("EMPTY IP POOL")
return
# send dhcp_offer message.
dhcp_offer_msg_type = '\x02'
self.logger.info("Send DHCP message type %s" %
(self.dhcp_msg_type_code[ord(dhcp_offer_msg_type)]))
msg_option = dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
value=dhcp_offer_msg_type)
options = dhcp.options(option_list=[msg_option])
hlen = len(addrconv.mac.text_to_bin(dhcp_pkt.chaddr))
dhcp_pkt = dhcp.dhcp(hlen=hlen,
op=dhcp.DHCP_BOOT_REPLY,
chaddr=dhcp_pkt.chaddr,
yiaddr=client_ip_addr,
giaddr=dhcp_pkt.giaddr,
xid=dhcp_pkt.xid,
options=options)
self._send_dhcp_packet(datapath, dhcp_pkt, port)
def create_dhcp_ack(self, dhcp_packet, dp, port, dst_ip="255.255.255.255"):
if self.temp_offered.get(dhcp_packet.xid) is None:
return
subnet_mask = self.space[dp.id].netmask
yiaddr = self.temp_offered[dhcp_packet.xid]["yiaddr"]
chaddr = self.temp_offered[dhcp_packet.xid]["chaddr"]
# add new or update existing dhcp bindings
# we remember only last used ip address
self.database[chaddr] = yiaddr
pkt = packet.Packet()
dhcp_ack_msg_type = b"\x05"
subnet_option = dhcp.option(
tag=dhcp.DHCP_SUBNET_MASK_OPT,
value=addrconv.ipv4.text_to_bin(subnet_mask),
)
time_option = dhcp.option(tag=dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
value=bytearray(self.LEASE_TIME_ACK))
msg_option = dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
value=dhcp_ack_msg_type)
dhcp_server_option = dhcp.option(tag=dhcp.DHCP_SERVER_IDENTIFIER_OPT,
value=bytearray(self._ip_to_int()))
options = dhcp.options(option_list=[
msg_option,
time_option,
subnet_option,
dhcp_server_option,
])
hlen = dhcp_packet.hlen
dhcp_pkt = dhcp.dhcp(
op=dhcp.DHCP_BOOT_REPLY,
hlen=hlen,
chaddr=dhcp_packet.chaddr,
yiaddr=yiaddr,
siaddr=self.DHCP_SERVER_IP,
giaddr=dhcp_packet.giaddr,
xid=dhcp_packet.xid,
options=options,
)
pkt.add_protocol(
ethernet.ethernet(ethertype=ether.ETH_TYPE_IP,
dst=chaddr,
src=self.DHCP_SERVER_MAC))
pkt.add_protocol(
ipv4.ipv4(dst=dst_ip, src=self.DHCP_SERVER_IP, proto=17))
pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
pkt.add_protocol(dhcp_pkt)
pkt.serialize()
self.inject_packet(pkt, dp, port)
def _send_dhcp_req_to_app(self, lport, options=None):
req = dhcp.dhcp(op=dhcp.DHCP_DISCOVER,
chaddr='aa:aa:aa:aa:aa:aa',
options=dhcp.options(options))
pkt = self._create_fake_empty_packet()
dhcp_response_pkt = self.app._create_dhcp_response(
pkt, req, dhcp.DHCP_OFFER, lport)
return dhcp_response_pkt
def create_dhcp_offer(self,
dhcp_packet,
dp,
port,
dst_ip="255.255.255.255"):
xid = dhcp_packet.xid # transaction id
chaddr = dhcp_packet.chaddr
yiaddr = None
previous_ip = self.database.get(chaddr)
if previous_ip:
if previous_ip in self.pools[dp.id]:
self.pools[dp.id].remove(previous_ip)
yiaddr = previous_ip
else:
yiaddr = self.pools[dp.id].pop(-1)
else:
yiaddr = self.pools[dp.id].pop(-1)
self.temp_offered[xid] = {"chaddr": chaddr, "yiaddr": yiaddr}
pkt = packet.Packet()
dhcp_offer_msg_type = b"\x02"
hlen = dhcp_packet.hlen
msg_option = dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
value=dhcp_offer_msg_type)
dhcp_server_option = dhcp.option(tag=dhcp.DHCP_SERVER_IDENTIFIER_OPT,
value=bytearray(self._ip_to_int()))
options = dhcp.options(option_list=[msg_option, dhcp_server_option])
pkt.add_protocol(
ethernet.ethernet(ethertype=ether.ETH_TYPE_IP,
dst=chaddr,
src=self.DHCP_SERVER_MAC))
pkt.add_protocol(
ipv4.ipv4(dst=dst_ip, src=self.DHCP_SERVER_IP, proto=17))
pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
pkt.add_protocol(
dhcp.dhcp(
hlen=hlen,
op=dhcp.DHCP_BOOT_REPLY,
yiaddr=yiaddr,
siaddr=self.DHCP_SERVER_IP,
xid=dhcp_packet.xid,
giaddr=dhcp_packet.giaddr,
chaddr=chaddr,
options=options,
))
pkt.serialize()
self.inject_packet(pkt, dp, port)
def _create_dhcp_ack(self, pkt, dhcp_packet, lport):
pkt_ipv4 = pkt.get_protocol(ipv4.ipv4)
pkt_ethernet = pkt.get_protocol(ethernet.ethernet)
subnet = self._get_subnet_by_port(lport)
if subnet is None:
LOG.error(_LE("No subnet found for port <%s>") %
lport.get_id())
return
dns = self._get_dns_address_list_bin(subnet)
host_routes = self._get_host_routes_list_bin(subnet, lport)
dhcp_server_address = str(self._get_dhcp_server_address(subnet))
gateway_address = self._get_port_gateway_address(subnet)
netmask_bin = self._get_port_netmask(subnet).packed
domain_name_bin = struct.pack('!256s', self.domain_name)
lease_time_bin = struct.pack('!I', self.lease_time)
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, b'\x05', 1),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, netmask_bin, 4),
dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT, gateway_address.packed, 4),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
lease_time_bin, 4),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, dns, len(dns)),
dhcp.option(DHCP_DOMAIN_NAME_OPT,
domain_name_bin,
len(self.domain_name)),
dhcp.option(DHCP_CLASSLESS_ROUTE, host_routes, len(host_routes))]
if self.advertise_mtu:
intreface_mtu = self._get_port_mtu(lport)
mtu_bin = struct.pack('!H', intreface_mtu)
option_list.append(dhcp.option(
DHCP_INTERFACE_MTU_OPT,
mtu_bin,
len(mtu_bin)))
options = dhcp.options(option_list=option_list)
dhcp_ack_pkt = ryu_packet.Packet()
dhcp_ack_pkt.add_protocol(ethernet.ethernet(
ethertype=ether.ETH_TYPE_IP,
dst=pkt_ethernet.src,
src=pkt_ethernet.dst))
dhcp_ack_pkt.add_protocol(ipv4.ipv4(dst=pkt_ipv4.src,
src=dhcp_server_address,
proto=pkt_ipv4.proto))
dhcp_ack_pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
dhcp_ack_pkt.add_protocol(dhcp.dhcp(op=2, chaddr=pkt_ethernet.src,
siaddr=dhcp_server_address,
boot_file=dhcp_packet.boot_file,
yiaddr=lport.get_ip(),
xid=dhcp_packet.xid,
options=options))
return dhcp_ack_pkt
def _create_dhcp_ack(self, pkt, dhcp_packet, lport):
pkt_ipv4 = pkt.get_protocol(ipv4.ipv4)
pkt_ethernet = pkt.get_protocol(ethernet.ethernet)
subnet = self._get_subnet_by_port(lport)
if subnet is None:
LOG.error(_LE("No subnet found for port <%s>") %
lport.get_id())
return
dns = self._get_dns_address_list_bin(subnet)
host_routes = self._get_host_routes_list_bin(subnet)
dhcp_server_address = str(self._get_dhcp_server_address(subnet))
gateway_address = self._get_port_gateway_address(subnet)
netmask_bin = self._get_port_netmask(subnet).packed
domain_name_bin = struct.pack('!256s', self.domain_name)
lease_time_bin = struct.pack('!I', self.lease_time)
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, b'\x05', 1),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, netmask_bin, 4),
dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT, gateway_address.packed, 4),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
lease_time_bin, 4),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, dns, len(dns)),
dhcp.option(DHCP_DOMAIN_NAME_OPT,
domain_name_bin,
len(self.domain_name)),
dhcp.option(DHCP_CLASSLESS_ROUTE, host_routes, len(host_routes))]
if self.advertise_mtu:
intreface_mtu = self._get_port_mtu(lport)
mtu_bin = struct.pack('!H', intreface_mtu)
option_list.append(dhcp.option(
DHCP_INTERFACE_MTU_OPT,
mtu_bin,
len(mtu_bin)))
options = dhcp.options(option_list=option_list)
dhcp_ack_pkt = ryu_packet.Packet()
dhcp_ack_pkt.add_protocol(ethernet.ethernet(
ethertype=ether.ETH_TYPE_IP,
dst=pkt_ethernet.src,
src=pkt_ethernet.dst))
dhcp_ack_pkt.add_protocol(ipv4.ipv4(dst=pkt_ipv4.src,
src=dhcp_server_address,
proto=pkt_ipv4.proto))
dhcp_ack_pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
dhcp_ack_pkt.add_protocol(dhcp.dhcp(op=2, chaddr=pkt_ethernet.src,
siaddr=dhcp_server_address,
boot_file=dhcp_packet.boot_file,
yiaddr=lport.get_ip(),
xid=dhcp_packet.xid,
options=options))
return dhcp_ack_pkt
def _create_dhcp_offer(self, pkt, dhcp_packet, lport):
pkt_ipv4 = pkt.get_protocol(ipv4.ipv4)
pkt_ethernet = pkt.get_protocol(ethernet.ethernet)
subnet = self._get_subnet_by_port(lport)
if subnet is None:
LOG.error(_LE("No subnet found for port <%s>") % lport.get_id())
return
dns = self._get_dns_address_list_bin(subnet)
dhcp_server_address = self._get_dhcp_server_address(subnet)
netmask_bin = self._get_port_netmask(subnet).packed
lease_time_bin = struct.pack('!I', self.lease_time)
gateway_address = self._get_port_gateway_address(subnet)
domain_name_bin = struct.pack('!256s', self.domain_name)
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, b'\x02', 1),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, netmask_bin, 4),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, dns, len(dns)),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT, lease_time_bin, 4),
dhcp.option(dhcp.DHCP_SERVER_IDENTIFIER_OPT,
dhcp_server_address.packed, 4),
dhcp.option(15, domain_name_bin, len(self.domain_name))
]
if gateway_address:
option_list.append(
dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT, gateway_address.packed,
4))
options = dhcp.options(option_list=option_list)
dhcp_offer_pkt = ryu_packet.Packet()
dhcp_offer_pkt.add_protocol(
ethernet.ethernet(ethertype=ether.ETH_TYPE_IP,
dst=pkt_ethernet.src,
src=pkt_ethernet.dst))
dhcp_offer_pkt.add_protocol(
ipv4.ipv4(dst=pkt_ipv4.src,
src=str(dhcp_server_address),
proto=pkt_ipv4.proto))
dhcp_offer_pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
dhcp_offer_pkt.add_protocol(
dhcp.dhcp(op=2,
chaddr=pkt_ethernet.src,
siaddr=str(dhcp_server_address),
boot_file=dhcp_packet.boot_file,
yiaddr=lport.get_ip(),
xid=dhcp_packet.xid,
options=options))
return dhcp_offer_pkt
def _create_dhcp_offer(self, pkt, dhcp_packet, lport):
pkt_ipv4 = pkt.get_protocol(ipv4.ipv4)
pkt_ethernet = pkt.get_protocol(ethernet.ethernet)
subnet = self._get_subnet_by_port(lport)
if subnet is None:
LOG.error(_LE("No subnet found for port <%s>") %
lport.get_id())
return
dns = self._get_dns_address_list_bin(subnet)
dhcp_server_address = self._get_dhcp_server_address(subnet)
netmask_bin = self._get_port_netmask(subnet).packed
lease_time_bin = struct.pack('!I', self.lease_time)
gateway_address = self._get_port_gateway_address(subnet)
domain_name_bin = struct.pack('!256s', self.domain_name)
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, b'\x02', 1),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, netmask_bin, 4),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, dns, len(dns)),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
lease_time_bin, 4),
dhcp.option(dhcp.DHCP_SERVER_IDENTIFIER_OPT,
dhcp_server_address.packed, 4),
dhcp.option(15, domain_name_bin, len(self.domain_name))]
if gateway_address:
option_list.append(dhcp.option(
dhcp.DHCP_GATEWAY_ADDR_OPT,
gateway_address.packed,
4))
options = dhcp.options(option_list=option_list)
dhcp_offer_pkt = ryu_packet.Packet()
dhcp_offer_pkt.add_protocol(ethernet.ethernet(
ethertype=ether.ETH_TYPE_IP,
dst=pkt_ethernet.src,
src=pkt_ethernet.dst))
dhcp_offer_pkt.add_protocol(ipv4.ipv4(dst=pkt_ipv4.src,
src=str(dhcp_server_address),
proto=pkt_ipv4.proto))
dhcp_offer_pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
dhcp_offer_pkt.add_protocol(dhcp.dhcp(op=2, chaddr=pkt_ethernet.src,
siaddr=str(dhcp_server_address),
boot_file=dhcp_packet.boot_file,
yiaddr=lport.get_ip(),
xid=dhcp_packet.xid,
options=options))
return dhcp_offer_pkt
def _create_dhcp_response(self, packet, dhcp_request, response_type,
lport):
pkt_ipv4 = packet.get_protocol(ipv4.ipv4)
pkt_ethernet = packet.get_protocol(ethernet.ethernet)
try:
subnet = lport.subnets[0]
except IndexError:
LOG.warning("No subnet found for port %s", lport.id)
return
dhcp_server_address = subnet.dhcp_ip
if not dhcp_server_address:
LOG.warning("Could not find DHCP server address for subnet %s",
subnet.id)
return
option_list = self._build_dhcp_options(dhcp_request, response_type,
lport, subnet,
dhcp_server_address)
options = dhcp.options(option_list=option_list)
dhcp_server_address = subnet.dhcp_ip
dhcp_response = ryu_packet.Packet()
dhcp_response.add_protocol(
ethernet.ethernet(ethertype=ether.ETH_TYPE_IP,
dst=pkt_ethernet.src,
src=pkt_ethernet.dst))
dhcp_response.add_protocol(
ipv4.ipv4(dst=pkt_ipv4.src,
src=dhcp_server_address,
proto=pkt_ipv4.proto))
dhcp_response.add_protocol(
udp.udp(src_port=const.DHCP_SERVER_PORT,
dst_port=const.DHCP_CLIENT_PORT))
siaddr = lport.dhcp_params.siaddr or dhcp_server_address
dhcp_response.add_protocol(
dhcp.dhcp(op=dhcp.DHCP_BOOT_REPLY,
chaddr=pkt_ethernet.src,
siaddr=siaddr,
boot_file=dhcp_request.boot_file,
yiaddr=lport.ip,
xid=dhcp_request.xid,
options=options))
return dhcp_response
def handle_dhcp_request(self, dhcp_pkt, datapath, port):
# send dhcp_ack message.
dhcp_ack_msg_type = '\x05'
self.logger.info("Send DHCP message type %s" %
(self.dhcp_msg_type_code[ord(dhcp_ack_msg_type)]))
subnet_option = dhcp.option(tag=dhcp.DHCP_SUBNET_MASK_OPT,
value=addrconv.ipv4.text_to_bin(
self.ip_network.netmask))
gw_option = dhcp.option(tag=dhcp.DHCP_GATEWAY_ADDR_OPT,
value=addrconv.ipv4.text_to_bin(self.gw_addr))
dns_option = dhcp.option(tag=dhcp.DHCP_DNS_SERVER_ADDR_OPT,
value=addrconv.ipv4.text_to_bin(
self.dns_addr))
time_option = dhcp.option(tag=dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
value='\xFF\xFF\xFF\xFF')
msg_option = dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
value=dhcp_ack_msg_type)
id_option = dhcp.option(tag=dhcp.DHCP_SERVER_IDENTIFIER_OPT,
value=addrconv.ipv4.text_to_bin(
self.dhcp_addr))
options = dhcp.options(option_list=[
msg_option, id_option, time_option, subnet_option, gw_option,
dns_option
])
hlen = len(addrconv.mac.text_to_bin(dhcp_pkt.chaddr))
# Look up IP by using client mac address
client_ip_addr = self.mac_to_client_ip[dhcp_pkt.chaddr]
dhcp_pkt = dhcp.dhcp(op=dhcp.DHCP_BOOT_REPLY,
hlen=hlen,
chaddr=dhcp_pkt.chaddr,
yiaddr=client_ip_addr,
giaddr=dhcp_pkt.giaddr,
xid=dhcp_pkt.xid,
options=options)
self._send_dhcp_packet(datapath, dhcp_pkt, port)
def handle_dhcp_request(self, dhcp_pkt, datapath, port):
# send dhcp_ack message.
dhcp_ack_msg_type = '\x05'
self.logger.info("Send DHCP message type %s" %
(self.dhcp_msg_type_code[ord(dhcp_ack_msg_type)]))
subnet_option = dhcp.option(tag=dhcp.DHCP_SUBNET_MASK_OPT,
value=addrconv.ipv4.text_to_bin(self.ip_network.netmask))
gw_option = dhcp.option(tag=dhcp.DHCP_GATEWAY_ADDR_OPT,
value=addrconv.ipv4.text_to_bin(self.gw_addr))
dns_option = dhcp.option(tag=dhcp.DHCP_DNS_SERVER_ADDR_OPT,
value=addrconv.ipv4.text_to_bin(self.dns_addr))
time_option = dhcp.option(tag=dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
value='\xFF\xFF\xFF\xFF')
msg_option = dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
value=dhcp_ack_msg_type)
id_option = dhcp.option(tag=dhcp.DHCP_SERVER_IDENTIFIER_OPT,
value=addrconv.ipv4.text_to_bin(self.dhcp_addr))
options = dhcp.options(option_list=[msg_option, id_option,
time_option, subnet_option,
gw_option, dns_option])
hlen = len(addrconv.mac.text_to_bin(dhcp_pkt.chaddr))
# Look up IP by using client mac address
client_ip_addr = self.mac_to_client_ip[dhcp_pkt.chaddr]
dhcp_pkt = dhcp.dhcp(op=dhcp.DHCP_BOOT_REPLY,
hlen=hlen,
chaddr=dhcp_pkt.chaddr,
yiaddr=client_ip_addr,
giaddr=dhcp_pkt.giaddr,
xid=dhcp_pkt.xid,
options=options)
self._send_dhcp_packet(datapath, dhcp_pkt, port)
def _handle_dhcp(self, pkt_dhcp, datapath, in_port):
dhcp_type = ord(pkt_dhcp.options.option_list[0].value)
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
# the message is DHCP_ DISCOVERY
if dhcp_type == 1:
self.logger.info("Recieve DHCP_DISCOVERY")
dhcp_offer = '\x02'
self.logger.info("Send DHCP_OFFER")
msg_option = dhcp.option(tag=53, value=dhcp_offer)
options = dhcp.options(option_list=[msg_option])
# allocate ip to host
yiaddr = self.ip_pool[0]
# generate the DHCP_OFFER packet
pkt_dhcp = dhcp.dhcp(op=2,
chaddr=pkt_dhcp.chaddr,
options=options,
hlen=6,
htype=1,
xid=pkt_dhcp.xid,
ciaddr=pkt_dhcp.ciaddr,
yiaddr=yiaddr)
pkt = packet.Packet()
pkt.add_protocol(
ethernet.ethernet(src=self.hw_addr, dst="ff:ff:ff:ff:ff:ff"))
pkt.add_protocol(
ipv4.ipv4(src=self.ip, dst="255.255.255.255", proto=17))
pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
pkt.add_protocol(pkt_dhcp)
self._send_packet(datapath, in_port, pkt)
# the message is DHCP_REQUEST
if dhcp_type == 3:
self.logger.info("Recieve DHCP_REQUEST")
dhcp_ack = '\x05'
self.logger.info("Send DHCP_ACK")
# set packet type
msg_option = dhcp.option(tag=53, value=dhcp_ack)
# set dhcp valid time
time_option = dhcp.option(tag=51, value='\x00\xFF\xFF\xFF')
# set net mask
mask_option = dhcp.option(tag=1, value=self.netmask)
options = dhcp.options(
option_list=[msg_option, time_option, mask_option])
yiaddr = self.ip_pool[0]
# delete the used ip
self.ip_pool.pop(0)
# generate the DHCP_ACK
pkt_dhcp = dhcp.dhcp(op=5,
chaddr=pkt_dhcp.chaddr,
options=options,
hlen=6,
htype=1,
xid=pkt_dhcp.xid,
ciaddr=pkt_dhcp.ciaddr,
yiaddr=yiaddr)
pkt = packet.Packet()
pkt.add_protocol(
ethernet.ethernet(src=self.hw_addr, dst="ff:ff:ff:ff:ff:ff"))
pkt.add_protocol(
ipv4.ipv4(src=self.ip, dst="255.255.255.255", proto=17))
pkt.add_protocol(udp.udp(src_port=67, dst_port=68))
pkt.add_protocol(pkt_dhcp)
self._send_packet(datapath, in_port, pkt)
# install flow table 0
cookie = 0
cookie_mask = 0
table_id = 0
next_table_id = 3
priority = 2000
buffer_id = ofproto.OFP_NO_BUFFER
print(pkt_dhcp.chaddr)
match = parser.OFPMatch(eth_type=0x800,
eth_src=pkt_dhcp.chaddr,
ip_proto=17,
udp_src=68)
instruction = [parser.OFPInstructionGotoTable(next_table_id)]
req = parser.OFPFlowMod(datapath=datapath,
command=ofproto.OFPFC_ADD,
cookie=cookie,
cookie_mask=cookie_mask,
table_id=table_id,
priority=priority,
match=match,
instructions=instruction)
datapath.send_msg(req)
# insatll flow table 3
table_id = 3
priority = 3000
instruction = [
parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS, [])
]
req = parser.OFPFlowMod(datapath=datapath,
command=ofproto.OFPFC_ADD,
cookie=cookie,
cookie_mask=cookie_mask,
table_id=table_id,
priority=priority,
out_port=ofproto.OFPP_ANY,
match=match,
instructions=instruction)
datapath.send_msg(req)
class Test_dhcp_offer_with_hlen_zero(unittest.TestCase):
op = dhcp.DHCP_BOOT_REPLY
chaddr = 'aa:aa:aa:aa:aa:aa'
htype = 1
hlen = 6
hops = 0
xid = 1
secs = 0
flags = 1
ciaddr = '192.168.10.10'
yiaddr = '192.168.20.20'
siaddr = '192.168.30.30'
giaddr = '192.168.40.40'
sname = 'abc'
boot_file = ''
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, b'\x02', 1),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, b'\xff\xff\xff\x00', 4),
dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT, b'\xc0\xa8\x0a\x09', 4),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, b'\xc0\xa8\x0a\x09', 4),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT, b'\x00\x03\xf4\x80', 4),
dhcp.option(dhcp.DHCP_RENEWAL_TIME_OPT, b'\x00\x01\xfa\x40', 4),
dhcp.option(dhcp.DHCP_REBINDING_TIME_OPT, b'\x00\x03\x75\xf0', 4),
dhcp.option(dhcp.DHCP_SERVER_IDENTIFIER_OPT, b'\xc0\xa8\x0a\x09', 4)
]
magic_cookie = '99.130.83.99'
options = dhcp.options(option_list=option_list,
options_len=50,
magic_cookie=magic_cookie)
dh = dhcp.dhcp(op,
chaddr,
options,
htype=htype,
hlen=0,
hops=hops,
xid=xid,
secs=secs,
flags=flags,
ciaddr=ciaddr,
yiaddr=yiaddr,
siaddr=siaddr,
giaddr=giaddr,
sname=sname,
boot_file=boot_file)
def test_init(self):
eq_(self.op, self.dh.op)
eq_(self.htype, self.dh.htype)
eq_(self.hlen, self.dh.hlen)
eq_(self.hops, self.dh.hops)
eq_(self.xid, self.dh.xid)
eq_(self.secs, self.dh.secs)
eq_(self.flags, self.dh.flags)
eq_(self.ciaddr, self.dh.ciaddr)
eq_(self.yiaddr, self.dh.yiaddr)
eq_(self.siaddr, self.dh.siaddr)
eq_(self.giaddr, self.dh.giaddr)
eq_(self.chaddr, self.dh.chaddr)
eq_(self.sname, self.dh.sname)
eq_(self.boot_file, self.dh.boot_file)
eq_(str(self.options), str(self.dh.options))
def _respond_dhcp(self, datapath, port, pool,
pkt_ethernet, pkt_vlan, pkt_ip, pkt_udp, pkt_dhcp):
# DHCP message type code
options = dict()
for option in pkt_dhcp.options.option_list:
options[option.tag] = option.value
src = pkt_dhcp.chaddr
# RESPONSE MSG
pkt = packet.Packet()
pkt.add_protocol(ethernet.ethernet(ethertype=pkt_ethernet.ethertype,
dst=pkt_ethernet.src,
src='00:00:00:00:00:00'))
if pkt_vlan:
pkt.add_protocol(vlan.vlan(cfi=pkt_vlan.cfi,
ethertype=pkt_vlan.ethertype,
pcp=pkt_vlan.pcp,
vid=pkt_vlan.vid))
pkt.add_protocol(ipv4.ipv4(src=pkt_ip.dst, dst=pkt_ip.src, proto=in_proto.IPPROTO_UDP))
pkt.add_protocol(udp.udp(src_port=pkt_udp.dst_port, dst_port=pkt_udp.src_port))
# DISCOVER MSG
dhcp_msg_type = ord(options[dhcp.DHCP_MESSAGE_TYPE_OPT])
if dhcp_msg_type == dhcp.DHCP_DISCOVER:
msg_type = dhcp.DHCP_OFFER
if src in self.leases:
offer = self.leases[src]
del self.leases[src]
self.offers[src] = offer
else:
offer = self.offers.get(src)
if offer is None:
if len(pool) == 0:
LOG.error("Out of IP addresses")
msg_type = dhcp.DHCP_NAK
offer = pool[0]
if dhcp.DHCP_REQUESTED_IP_ADDR_OPT in options:
wanted_ip = IPAddr(addrconv.ipv4.bin_to_text(options[dhcp.DHCP_REQUESTED_IP_ADDR_OPT].value))
if wanted_ip in pool:
offer = wanted_ip
pool.remove(offer)
self.offers[src] = offer
wanted_opts = list()
if dhcp.DHCP_PARAMETER_REQUEST_LIST_OPT in options:
fmt = "s" * len(options[dhcp.DHCP_PARAMETER_REQUEST_LIST_OPT])
wanted_opt_set = struct.unpack(fmt, options[dhcp.DHCP_PARAMETER_REQUEST_LIST_OPT])
for i in wanted_opt_set:
wanted_opts.append(ord(i))
option_list = list()
option_list.append(dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, chr(msg_type), length=1))
if msg_type is not dhcp.DHCP_NAK:
if dhcp.DHCP_SUBNET_MASK_OPT in wanted_opts:
option_list.append(dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT,
addrconv.ipv4.text_to_bin(self.subnet.toStr()),
length=4))
if dhcp.DHCP_GATEWAY_ADDR_OPT in wanted_opts and self.router_addr is not None:
option_list.append(dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT,
addrconv.ipv4.text_to_bin(self.router_addr.toStr()),
length=4))
if dhcp.DHCP_DNS_SERVER_ADDR_OPT in wanted_opts and self.dns_addr is not None:
option_list.append(dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT,
addrconv.ipv4.text_to_bin(self.dns_addr.toStr()),
length=4))
option_list.append(dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
chr(self.lease_time),
length=4))
option_list.append(dhcp.option(dhcp.DHCP_RENEWAL_TIME_OPT, chr(self.lease_time / 2), length=4))
option_list.append(dhcp.option(dhcp.DHCP_REBINDING_TIME_OPT, chr(self.lease_time * 7 / 8), length=4))
resp_options = dhcp.options(option_list=option_list)
pkt.add_protocol(dhcp.dhcp(op=self._MSG_TYPE_BOOT_REPLY, chaddr=pkt_dhcp.chaddr, options=resp_options,
xid=pkt_dhcp.xid, ciaddr=pkt_dhcp.ciaddr, yiaddr=offer.toStr(),
siaddr=self.ip_addr.toStr(), giaddr='0.0.0.0', sname='', boot_file=''))
# REQUEST MSG
if dhcp_msg_type == dhcp.DHCP_REQUEST:
msg_type = dhcp.DHCP_ACK
if dhcp.DHCP_REQUESTED_IP_ADDR_OPT not in options:
return
wanted_ip = IPAddr(addrconv.ipv4.bin_to_text(options[dhcp.DHCP_REQUESTED_IP_ADDR_OPT]))
got_ip = None
if src in self.leases:
if wanted_ip != self.leases[src]:
pool.append(self.leases[src])
del self.leases[src]
else:
got_ip = self.leases[src]
if got_ip is None:
if src in self.offers:
if wanted_ip != self.offers[src]:
pool.append(self.offers[src])
del self.offers[src]
else:
got_ip = self.offers[src]
if got_ip is None:
if wanted_ip in pool:
pool.remove(wanted_ip)
got_ip = wanted_ip
if got_ip is None:
LOG.warn("%s asked for un-offered %s", src, wanted_ip.toStr())
msg_type = dhcp.DHCP_NAK
wanted_opts = list()
if dhcp.DHCP_PARAMETER_REQUEST_LIST_OPT in options:
fmt = "s" * len(options[dhcp.DHCP_PARAMETER_REQUEST_LIST_OPT])
wanted_opt_set = struct.unpack(fmt, options[dhcp.DHCP_PARAMETER_REQUEST_LIST_OPT])
for i in wanted_opt_set:
wanted_opts.append(ord(i))
# DHCP options tag code
option_list = list()
option_list.append(dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, chr(msg_type), length=1))
if msg_type is not dhcp.DHCP_NAK:
if dhcp.DHCP_SUBNET_MASK_OPT in wanted_opts:
option_list.append(dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT,
addrconv.ipv4.text_to_bin(self.subnet.toStr()),
length=4))
if dhcp.DHCP_GATEWAY_ADDR_OPT in wanted_opts and self.router_addr is not None:
option_list.append(dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT,
addrconv.ipv4.text_to_bin(self.router_addr.toStr()),
length=4))
if dhcp.DHCP_DNS_SERVER_ADDR_OPT in wanted_opts and self.dns_addr is not None:
option_list.append(dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT,
addrconv.ipv4.text_to_bin(self.dns_addr.toStr()),
length=4))
option_list.append(dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
chr(self.lease_time),
length=4))
option_list.append(dhcp.option(dhcp.DHCP_RENEWAL_TIME_OPT, chr(self.lease_time / 2), length=4))
option_list.append(dhcp.option(dhcp.DHCP_REBINDING_TIME_OPT, chr(self.lease_time * 7 / 8), length=4))
resp_options = dhcp.options(option_list=option_list)
pkt.add_protocol(dhcp.dhcp(op=self._MSG_TYPE_BOOT_REPLY, chaddr=pkt_dhcp.chaddr, options=resp_options,
xid=pkt_dhcp.xid, ciaddr=pkt_dhcp.ciaddr, yiaddr=wanted_ip.toStr(),
siaddr=self.ip_addr.toStr(), giaddr='0.0.0.0', sname='', boot_file=''))
# RELEASE MSG
if dhcp_msg_type == dhcp.DHCP_RELEASE:
if self.leases.get(src).toStr() != pkt_dhcp.ciaddr:
LOG.warn("%s tried to release unleased %s" % (src, pkt_dhcp.ciaddr))
return
del self.leases[src]
pool.append(pkt_dhcp.ciaddr)
LOG.info("%s released %s" % (src, pkt_dhcp.ciaddr))
self._send_dhcp_reply(datapath, port, pkt)
return True
class Test_dhcp_offer(unittest.TestCase):
op = dhcp.DHCP_BOOT_REPLY
chaddr = 'aa:aa:aa:aa:aa:aa'
htype = 1
hlen = 6
hops = 0
xid = 1
secs = 0
flags = 1
ciaddr = '192.168.10.10'
yiaddr = '192.168.20.20'
siaddr = '192.168.30.30'
giaddr = '192.168.40.40'
sname = 'abc'
boot_file = b''
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, b'\x02', 1),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, b'\xff\xff\xff\x00', 4),
dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT, b'\xc0\xa8\x0a\x09', 4),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, b'\xc0\xa8\x0a\x09', 4),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT, b'\x00\x03\xf4\x80', 4),
dhcp.option(dhcp.DHCP_RENEWAL_TIME_OPT, b'\x00\x01\xfa\x40', 4),
dhcp.option(dhcp.DHCP_REBINDING_TIME_OPT, b'\x00\x03\x75\xf0', 4),
dhcp.option(dhcp.DHCP_SERVER_IDENTIFIER_OPT, b'\xc0\xa8\x0a\x09', 4)
]
magic_cookie = '99.130.83.99'
options = dhcp.options(option_list=option_list,
options_len=50,
magic_cookie=magic_cookie)
dh = dhcp.dhcp(op,
chaddr,
options,
htype=htype,
hlen=hlen,
hops=hops,
xid=xid,
secs=secs,
flags=flags,
ciaddr=ciaddr,
yiaddr=yiaddr,
siaddr=siaddr,
giaddr=giaddr,
sname=sname,
boot_file=boot_file)
buf = b"\x02\x01\x06\x00\x00\x00\x00\x01\x00\x00\x00\x01\xc0\xa8\x0a\x0a"\
+ b"\xc0\xa8\x14\x14\xc0\xa8\x1e\x1e\xc0\xa8\x28\x28\xaa\xaa\xaa\xaa"\
+ b"\xaa\xaa\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x61\x62\x63\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"\
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x63\x82\x53\x63"\
+ b"\x35\x01\x02\x01\x04\xff\xff\xff\x00\x03\x04\xc0\xa8\x0a\x09\x06"\
+ b"\x04\xc0\xa8\x0a\x09\x33\x04\x00\x03\xf4\x80\x3a\x04\x00\x01\xfa"\
+ b"\x40\x3b\x04\x00\x03\x75\xf0\x36\x04\xc0\xa8\x0a\x09\xff"
def setUp(self):
pass
def tearDown(self):
pass
def test_init(self):
eq_(self.op, self.dh.op)
eq_(self.htype, self.dh.htype)
eq_(self.hlen, self.dh.hlen)
eq_(self.hops, self.dh.hops)
eq_(self.xid, self.dh.xid)
eq_(self.secs, self.dh.secs)
eq_(self.flags, self.dh.flags)
eq_(self.ciaddr, self.dh.ciaddr)
eq_(self.yiaddr, self.dh.yiaddr)
eq_(self.siaddr, self.dh.siaddr)
eq_(self.giaddr, self.dh.giaddr)
eq_(self.chaddr, self.dh.chaddr)
eq_(self.sname, self.dh.sname)
eq_(self.boot_file, self.dh.boot_file)
eq_(str(self.options), str(self.dh.options))
def test_parser(self):
_res = self.dh.parser(self.buf)
if type(_res) is tuple:
res = _res[0]
else:
res = _res
eq_(self.op, res.op)
eq_(self.htype, res.htype)
eq_(self.hlen, res.hlen)
eq_(self.hops, res.hops)
eq_(self.xid, res.xid)
eq_(self.secs, res.secs)
eq_(self.flags, res.flags)
eq_(self.ciaddr, res.ciaddr)
eq_(self.yiaddr, res.yiaddr)
eq_(self.siaddr, res.siaddr)
eq_(self.giaddr, res.giaddr)
eq_(self.chaddr, res.chaddr)
# sname is 64 byte length. rest of data is filled by '\x00'.
eq_(self.sname.ljust(64, '\x00'), res.sname)
# boof_file is 128 byte length. rest of data is filled by '\x00'.
eq_(self.boot_file.ljust(128, b'\x00'), res.boot_file)
eq_(str(self.options), str(res.options))
def test_parser_corrupted(self):
buf = self.buf[:128 - (14 + 20 + 8)]
_res = self.dh.parser(buf)
def test_serialize(self):
data = bytearray()
prev = None
buf = self.dh.serialize(data, prev)
res = struct.unpack_from(dhcp.dhcp._DHCP_PACK_STR,
six.binary_type(buf))
eq_(self.op, res[0])
eq_(self.htype, res[1])
eq_(self.hlen, res[2])
eq_(self.hops, res[3])
eq_(self.xid, res[4])
eq_(self.secs, res[5])
eq_(self.flags, res[6])
eq_(self.ciaddr, addrconv.ipv4.bin_to_text(res[7]))
eq_(self.yiaddr, addrconv.ipv4.bin_to_text(res[8]))
eq_(self.siaddr, addrconv.ipv4.bin_to_text(res[9]))
eq_(self.giaddr, addrconv.ipv4.bin_to_text(res[10]))
eq_(self.chaddr, addrconv.mac.bin_to_text(res[11][:6]))
# sname is 64 byte length. rest of data is filled by '\x00'.
eq_(self.sname.ljust(64, '\x00'), res[12].decode('ascii'))
# boof_file is 128 byte length. rest of data is filled by '\x00'.
eq_(self.boot_file.ljust(128, b'\x00'), res[13])
options = dhcp.options.parser(
buf[struct.calcsize(dhcp.dhcp._DHCP_PACK_STR):])
eq_(str(self.options), str(options))
def test_to_string(self):
option_values = ['tag', 'length', 'value']
opt_str_list = []
for option in self.option_list:
_opt_str = ','.join([
'%s=%s' % (k, repr(getattr(option, k)))
for k, v in inspect.getmembers(option) if k in option_values
])
opt_str = '%s(%s)' % (dhcp.option.__name__, _opt_str)
opt_str_list.append(opt_str)
option_str = '[%s]' % ', '.join(opt_str_list)
opts_vals = {
'magic_cookie': repr(self.magic_cookie),
'option_list': option_str,
'options_len': repr(self.options.options_len)
}
_options_str = ','.join([
'%s=%s' % (k, opts_vals[k])
for k, v in inspect.getmembers(self.options) if k in opts_vals
])
options_str = '%s(%s)' % (dhcp.options.__name__, _options_str)
dhcp_values = {
'op': repr(self.op),
'htype': repr(self.htype),
'hlen': repr(self.hlen),
'hops': repr(self.hops),
'xid': repr(self.xid),
'secs': repr(self.secs),
'flags': repr(self.flags),
'ciaddr': repr(self.ciaddr),
'yiaddr': repr(self.yiaddr),
'siaddr': repr(self.siaddr),
'giaddr': repr(self.giaddr),
'chaddr': repr(self.chaddr),
'sname': repr(self.sname),
'boot_file': repr(self.boot_file),
'options': options_str
}
_dh_str = ','.join([
'%s=%s' % (k, dhcp_values[k])
for k, v in inspect.getmembers(self.dh) if k in dhcp_values
])
dh_str = '%s(%s)' % (dhcp.dhcp.__name__, _dh_str)
eq_(str(self.dh), dh_str)
eq_(repr(self.dh), dh_str)
def test_json(self):
jsondict = self.dh.to_jsondict()
dh = dhcp.dhcp.from_jsondict(jsondict['dhcp'])
eq_(str(self.dh), str(dh))
def _create_dhcp_packet(self, packet, dhcp_packet, pkt_type, lport):
pkt_ipv4 = packet.get_protocol(ipv4.ipv4)
pkt_ethernet = packet.get_protocol(ethernet.ethernet)
try:
subnet = lport.subnets[0]
except IndexError:
LOG.warning("No subnet found for port %s", lport.id)
return
pkt_type_packed = struct.pack('!B', pkt_type)
dns = self._get_dns_address_list_bin(subnet)
host_routes = self._get_host_routes_list_bin(subnet, lport)
dhcp_server_address = subnet.dhcp_ip
if not dhcp_server_address:
LOG.warning("Could not find DHCP server address for subnet %s",
subnet.id)
return
netmask_bin = subnet.cidr.netmask.packed
domain_name_bin = struct.pack('!%ss' % len(self.domain_name),
self.domain_name)
lease_time_bin = struct.pack('!I', self.lease_time)
option_list = [
dhcp.option(dhcp.DHCP_MESSAGE_TYPE_OPT, pkt_type_packed),
dhcp.option(dhcp.DHCP_SUBNET_MASK_OPT, netmask_bin),
dhcp.option(dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT, lease_time_bin),
dhcp.option(dhcp.DHCP_SERVER_IDENTIFIER_OPT,
dhcp_server_address.packed),
dhcp.option(dhcp.DHCP_DNS_SERVER_ADDR_OPT, dns),
dhcp.option(dhcp.DHCP_DOMAIN_NAME_OPT, domain_name_bin),
dhcp.option(dhcp.DHCP_CLASSLESS_ROUTE_OPT, host_routes),
]
gw_ip = self._get_port_gateway_address(subnet, lport)
if gw_ip:
option_list.append(
dhcp.option(dhcp.DHCP_GATEWAY_ADDR_OPT,
netaddr.IPAddress(gw_ip).packed))
if pkt_type == dhcp.DHCP_ACK:
intreface_mtu = self._get_port_mtu(lport)
mtu_bin = struct.pack('!H', intreface_mtu)
option_list.append(
dhcp.option(dhcp.DHCP_INTERFACE_MTU_OPT, mtu_bin))
options = dhcp.options(option_list=option_list)
dhcp_pkt = ryu_packet.Packet()
dhcp_pkt.add_protocol(
ethernet.ethernet(ethertype=ether.ETH_TYPE_IP,
dst=pkt_ethernet.src,
src=pkt_ethernet.dst))
dhcp_pkt.add_protocol(
ipv4.ipv4(dst=pkt_ipv4.src,
src=dhcp_server_address,
proto=pkt_ipv4.proto))
dhcp_pkt.add_protocol(
udp.udp(src_port=const.DHCP_SERVER_PORT,
dst_port=const.DHCP_CLIENT_PORT))
dhcp_pkt.add_protocol(
dhcp.dhcp(op=dhcp.DHCP_BOOT_REPLY,
chaddr=pkt_ethernet.src,
siaddr=dhcp_server_address,
boot_file=dhcp_packet.boot_file,
yiaddr=lport.ip,
xid=dhcp_packet.xid,
options=options))
return dhcp_pkt