214 lines
8.5 KiB
Python
214 lines
8.5 KiB
Python
# Copyright (c) 2021 China Unicom Cloud Data Co.,Ltd.
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# Copyright (c) 2019 - 2020 China Telecom Corporation
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import struct
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import netaddr
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from neutron_lib import constants
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from os_ken.lib import addrconv
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from os_ken.lib.packet import dhcp
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from os_ken.lib.packet import ethernet
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from os_ken.lib.packet import ipv4
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from os_ken.lib.packet import packet
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from os_ken.lib.packet import udp
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from oslo_config import cfg
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from oslo_log import log as logging
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from neutron.agent.l2.extensions.dhcp import base as dhcp_base
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LOG = logging.getLogger(__name__)
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DHCPV4_TYPE_MAP = {dhcp.DHCP_DISCOVER: 'DHCPDISCOVER',
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dhcp.DHCP_OFFER: 'DHCPOFFER',
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dhcp.DHCP_REQUEST: 'DHCPREQUEST',
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dhcp.DHCP_ACK: 'DHCPACK'}
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DHCPV4_MSG_TYPE_BYTES_ACK = b'\x05'
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DHCPV4_MSG_TYPE_BYTES_OFFER = b'\x02'
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# TODO(liuyulong): Move to os-ken(ryu) someday.
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# Align the name prefix with the definitions in
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# os_ken.lib.packet.dhcp.
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DHCP_BROADCAST_ADDRESS_OPT = 28
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class DHCPIPv4Responder(dhcp_base.DHCPResponderBase):
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def get_bin_routes(self, gateway=None, routes=None):
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bin_routes = b''
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# Default routes
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default_route = self.get_bin_route(constants.IPv4_ANY, gateway)
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bin_routes += default_route
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# For some VMs they may need the metadata IP's route, we move
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# the destination to gateway IP.
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if gateway:
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meta_route = self.get_bin_route(
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constants.METADATA_V4_CIDR, gateway)
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bin_routes += meta_route
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# Subnet routes
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for route in routes or []:
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bin_routes += self.get_bin_route(route['destination'],
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route['nexthop'])
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return bin_routes
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def get_dhcp_options(self, port_info, is_ack=False):
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fixed_ips = port_info['fixed_ips']
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net = netaddr.IPNetwork(fixed_ips[0]['cidr'])
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dns_nameservers = fixed_ips[0]['dns_nameservers']
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host_routes = fixed_ips[0]['host_routes']
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gateway_ip = fixed_ips[0]['gateway_ip']
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bin_server = addrconv.ipv4.text_to_bin(gateway_ip)
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option_list = []
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if is_ack:
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
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value=DHCPV4_MSG_TYPE_BYTES_ACK))
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else:
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_MESSAGE_TYPE_OPT,
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value=DHCPV4_MSG_TYPE_BYTES_OFFER))
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_SERVER_IDENTIFIER_OPT,
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value=bin_server))
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_IP_ADDR_LEASE_TIME_OPT,
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value=struct.pack(
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'!i', cfg.CONF.dhcp_lease_duration)))
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if cfg.CONF.DHCP.dhcp_renewal_time > 0:
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_RENEWAL_TIME_OPT,
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value=struct.pack(
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'!I', cfg.CONF.DHCP.dhcp_renewal_time)))
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if cfg.CONF.DHCP.dhcp_rebinding_time > 0:
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_REBINDING_TIME_OPT,
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value=struct.pack(
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'!I', cfg.CONF.DHCP.dhcp_rebinding_time)))
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_SUBNET_MASK_OPT,
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value=addrconv.ipv4.text_to_bin(str(net.netmask))))
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# Option: (28) Broadcast Address
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option_list.append(
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dhcp.option(tag=DHCP_BROADCAST_ADDRESS_OPT,
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value=addrconv.ipv4.text_to_bin(str(net.broadcast))))
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# DNS
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if dns_nameservers:
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_DNS_SERVER_ADDR_OPT,
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value=self.get_bin_dns(dns_nameservers)))
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if cfg.CONF.dns_domain:
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_DOMAIN_NAME_OPT,
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value=struct.pack(
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'!%ds' % len(cfg.CONF.dns_domain),
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str.encode(cfg.CONF.dns_domain))))
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_GATEWAY_ADDR_OPT,
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value=bin_server))
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# Static routes
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_CLASSLESS_ROUTE_OPT,
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value=self.get_bin_routes(gateway_ip,
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host_routes)))
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# MTU
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mtu = int(port_info.get('mtu', 0))
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if mtu > 0:
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mtu_bin = struct.pack('!H', mtu)
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option_list.append(
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dhcp.option(tag=dhcp.DHCP_INTERFACE_MTU_OPT,
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value=mtu_bin))
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options = dhcp.options(option_list=option_list)
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return options
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def get_ret_packet(self, packet_in, port_info, is_ack=False):
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ip_info = self.get_port_ip(port_info,
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ip_version=constants.IP_VERSION_4)
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if not ip_info:
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return
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ip_addr = ip_info['ip_address']
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gateway_ip = ip_info['gateway_ip']
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options = self.get_dhcp_options(port_info, is_ack)
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if is_ack:
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fqdn = 'host-%s' % ip_addr.replace('.', '-').replace(':', '-')
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if cfg.CONF.dns_domain:
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fqdn = '%s.%s' % (fqdn, cfg.CONF.dns_domain)
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domain_name_bin = struct.pack('!%ds' % len(fqdn),
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bytes(str(fqdn).encode()))
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options.option_list.append(
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dhcp.option(tag=dhcp.DHCP_HOST_NAME_OPT,
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value=domain_name_bin))
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header_eth = packet_in.get_protocol(ethernet.ethernet)
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header_ipv4 = packet_in.get_protocol(ipv4.ipv4)
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header_dhcp = packet_in.get_protocol(dhcp.dhcp)
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ret_pkt = packet.Packet()
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ret_pkt.add_protocol(ethernet.ethernet(
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ethertype=header_eth.ethertype,
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dst=header_eth.src,
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src=self.hw_addr))
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ret_pkt.add_protocol(
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ipv4.ipv4(dst=header_ipv4.dst,
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src=gateway_ip,
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proto=header_ipv4.proto))
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ret_pkt.add_protocol(udp.udp(src_port=constants.DHCP_RESPONSE_PORT,
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dst_port=constants.DHCP_CLIENT_PORT))
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ret_pkt.add_protocol(dhcp.dhcp(op=dhcp.DHCP_BOOT_REPLY,
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chaddr=header_eth.src,
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siaddr=gateway_ip,
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boot_file=header_dhcp.boot_file,
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yiaddr=ip_addr,
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xid=header_dhcp.xid,
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options=options))
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return ret_pkt
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def assemble_ack(self, pkt, port_info):
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ack = self.get_ret_packet(pkt, port_info, is_ack=True)
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LOG.debug("DHCP controller DHCPv4 ACK assembled: %s", ack)
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return ack
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def assemble_offer(self, pkt, port_info):
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offer = self.get_ret_packet(pkt, port_info)
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LOG.debug("DHCP controller DHCPv4 offer assemble: %s", offer)
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return offer
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def get_state(self, pkt_dhcp):
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dhcp_state = ord(
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[opt for opt in pkt_dhcp.options.option_list
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if opt.tag == dhcp.DHCP_MESSAGE_TYPE_OPT][0].value)
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return DHCPV4_TYPE_MAP.get(dhcp_state)
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def handle_dhcp(self, datapath, ofport, pkt, port_info):
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pkt_dhcp = pkt.get_protocol(dhcp.dhcp)
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dhcp_state = self.get_state(pkt_dhcp)
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LOG.debug("DHCP controller DHCPv4 packet received, "
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"state: %s, data: %s",
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dhcp_state, pkt_dhcp)
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if dhcp_state == 'DHCPDISCOVER':
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self.packet_out(datapath, ofport,
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self.assemble_offer(pkt, port_info))
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elif dhcp_state == 'DHCPREQUEST':
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self.packet_out(datapath, ofport,
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self.assemble_ack(pkt, port_info))
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