383 lines
16 KiB
Python
383 lines
16 KiB
Python
# Copyright 2012, Nachi Ueno, NTT MCL, Inc.
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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 netaddr
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from oslo.config import cfg
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from neutron.agent import firewall
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from neutron.agent.linux import iptables_manager
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from neutron.common import constants
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from neutron.common import ipv6_utils
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from neutron.openstack.common import log as logging
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LOG = logging.getLogger(__name__)
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SG_CHAIN = 'sg-chain'
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INGRESS_DIRECTION = 'ingress'
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EGRESS_DIRECTION = 'egress'
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SPOOF_FILTER = 'spoof-filter'
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CHAIN_NAME_PREFIX = {INGRESS_DIRECTION: 'i',
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EGRESS_DIRECTION: 'o',
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SPOOF_FILTER: 's'}
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LINUX_DEV_LEN = 14
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class IptablesFirewallDriver(firewall.FirewallDriver):
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"""Driver which enforces security groups through iptables rules."""
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IPTABLES_DIRECTION = {INGRESS_DIRECTION: 'physdev-out',
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EGRESS_DIRECTION: 'physdev-in'}
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def __init__(self):
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self.iptables = iptables_manager.IptablesManager(
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root_helper=cfg.CONF.AGENT.root_helper,
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use_ipv6=ipv6_utils.is_enabled())
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# list of port which has security group
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self.filtered_ports = {}
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self._add_fallback_chain_v4v6()
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self._defer_apply = False
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self._pre_defer_filtered_ports = None
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@property
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def ports(self):
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return self.filtered_ports
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def prepare_port_filter(self, port):
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LOG.debug(_("Preparing device (%s) filter"), port['device'])
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self._remove_chains()
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self.filtered_ports[port['device']] = port
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# each security group has it own chains
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self._setup_chains()
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self.iptables.apply()
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def update_port_filter(self, port):
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LOG.debug(_("Updating device (%s) filter"), port['device'])
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if port['device'] not in self.filtered_ports:
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LOG.info(_('Attempted to update port filter which is not '
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'filtered %s'), port['device'])
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return
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self._remove_chains()
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self.filtered_ports[port['device']] = port
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self._setup_chains()
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self.iptables.apply()
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def remove_port_filter(self, port):
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LOG.debug(_("Removing device (%s) filter"), port['device'])
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if not self.filtered_ports.get(port['device']):
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LOG.info(_('Attempted to remove port filter which is not '
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'filtered %r'), port)
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return
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self._remove_chains()
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self.filtered_ports.pop(port['device'], None)
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self._setup_chains()
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self.iptables.apply()
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def _setup_chains(self):
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"""Setup ingress and egress chain for a port."""
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if not self._defer_apply:
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self._setup_chains_apply(self.filtered_ports)
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def _setup_chains_apply(self, ports):
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self._add_chain_by_name_v4v6(SG_CHAIN)
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for port in ports.values():
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self._setup_chain(port, INGRESS_DIRECTION)
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self._setup_chain(port, EGRESS_DIRECTION)
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self.iptables.ipv4['filter'].add_rule(SG_CHAIN, '-j ACCEPT')
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self.iptables.ipv6['filter'].add_rule(SG_CHAIN, '-j ACCEPT')
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def _remove_chains(self):
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"""Remove ingress and egress chain for a port."""
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if not self._defer_apply:
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self._remove_chains_apply(self.filtered_ports)
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def _remove_chains_apply(self, ports):
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for port in ports.values():
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self._remove_chain(port, INGRESS_DIRECTION)
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self._remove_chain(port, EGRESS_DIRECTION)
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self._remove_chain(port, SPOOF_FILTER)
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self._remove_chain_by_name_v4v6(SG_CHAIN)
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def _setup_chain(self, port, DIRECTION):
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self._add_chain(port, DIRECTION)
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self._add_rule_by_security_group(port, DIRECTION)
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def _remove_chain(self, port, DIRECTION):
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chain_name = self._port_chain_name(port, DIRECTION)
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self._remove_chain_by_name_v4v6(chain_name)
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def _add_fallback_chain_v4v6(self):
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self.iptables.ipv4['filter'].add_chain('sg-fallback')
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self.iptables.ipv4['filter'].add_rule('sg-fallback', '-j DROP')
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self.iptables.ipv6['filter'].add_chain('sg-fallback')
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self.iptables.ipv6['filter'].add_rule('sg-fallback', '-j DROP')
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def _add_chain_by_name_v4v6(self, chain_name):
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self.iptables.ipv6['filter'].add_chain(chain_name)
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self.iptables.ipv4['filter'].add_chain(chain_name)
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def _remove_chain_by_name_v4v6(self, chain_name):
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self.iptables.ipv4['filter'].ensure_remove_chain(chain_name)
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self.iptables.ipv6['filter'].ensure_remove_chain(chain_name)
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def _add_rule_to_chain_v4v6(self, chain_name, ipv4_rules, ipv6_rules):
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for rule in ipv4_rules:
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self.iptables.ipv4['filter'].add_rule(chain_name, rule)
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for rule in ipv6_rules:
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self.iptables.ipv6['filter'].add_rule(chain_name, rule)
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def _get_device_name(self, port):
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return port['device']
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def _add_chain(self, port, direction):
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chain_name = self._port_chain_name(port, direction)
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self._add_chain_by_name_v4v6(chain_name)
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# Note(nati) jump to the security group chain (SG_CHAIN)
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# This is needed because the packet may much two rule in port
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# if the two port is in the same host
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# We accept the packet at the end of SG_CHAIN.
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# jump to the security group chain
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device = self._get_device_name(port)
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jump_rule = ['-m physdev --%s %s --physdev-is-bridged '
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'-j $%s' % (self.IPTABLES_DIRECTION[direction],
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device,
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SG_CHAIN)]
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self._add_rule_to_chain_v4v6('FORWARD', jump_rule, jump_rule)
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# jump to the chain based on the device
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jump_rule = ['-m physdev --%s %s --physdev-is-bridged '
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'-j $%s' % (self.IPTABLES_DIRECTION[direction],
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device,
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chain_name)]
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self._add_rule_to_chain_v4v6(SG_CHAIN, jump_rule, jump_rule)
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if direction == EGRESS_DIRECTION:
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self._add_rule_to_chain_v4v6('INPUT', jump_rule, jump_rule)
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def _split_sgr_by_ethertype(self, security_group_rules):
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ipv4_sg_rules = []
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ipv6_sg_rules = []
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for rule in security_group_rules:
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if rule.get('ethertype') == constants.IPv4:
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ipv4_sg_rules.append(rule)
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elif rule.get('ethertype') == constants.IPv6:
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if rule.get('protocol') == 'icmp':
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rule['protocol'] = 'icmpv6'
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ipv6_sg_rules.append(rule)
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return ipv4_sg_rules, ipv6_sg_rules
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def _select_sgr_by_direction(self, port, direction):
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return [rule
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for rule in port.get('security_group_rules', [])
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if rule['direction'] == direction]
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def _setup_spoof_filter_chain(self, port, table, mac_ip_pairs, rules):
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if mac_ip_pairs:
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chain_name = self._port_chain_name(port, SPOOF_FILTER)
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table.add_chain(chain_name)
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for mac, ip in mac_ip_pairs:
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if ip is None:
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# If fixed_ips is [] this rule will be added to the end
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# of the list after the allowed_address_pair rules.
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table.add_rule(chain_name,
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'-m mac --mac-source %s -j RETURN'
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% mac)
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else:
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table.add_rule(chain_name,
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'-m mac --mac-source %s -s %s -j RETURN'
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% (mac, ip))
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table.add_rule(chain_name, '-j DROP')
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rules.append('-j $%s' % chain_name)
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def _build_ipv4v6_mac_ip_list(self, mac, ip_address, mac_ipv4_pairs,
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mac_ipv6_pairs):
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if netaddr.IPNetwork(ip_address).version == 4:
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mac_ipv4_pairs.append((mac, ip_address))
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else:
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mac_ipv6_pairs.append((mac, ip_address))
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def _spoofing_rule(self, port, ipv4_rules, ipv6_rules):
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#Note(nati) allow dhcp or RA packet
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ipv4_rules += ['-p udp -m udp --sport 68 --dport 67 -j RETURN']
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ipv6_rules += ['-p icmpv6 -j RETURN']
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ipv6_rules += ['-p udp -m udp --sport 546 --dport 547 -j RETURN']
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mac_ipv4_pairs = []
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mac_ipv6_pairs = []
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if isinstance(port.get('allowed_address_pairs'), list):
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for address_pair in port['allowed_address_pairs']:
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self._build_ipv4v6_mac_ip_list(address_pair['mac_address'],
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address_pair['ip_address'],
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mac_ipv4_pairs,
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mac_ipv6_pairs)
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for ip in port['fixed_ips']:
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self._build_ipv4v6_mac_ip_list(port['mac_address'], ip,
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mac_ipv4_pairs, mac_ipv6_pairs)
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if not port['fixed_ips']:
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mac_ipv4_pairs.append((port['mac_address'], None))
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mac_ipv6_pairs.append((port['mac_address'], None))
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self._setup_spoof_filter_chain(port, self.iptables.ipv4['filter'],
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mac_ipv4_pairs, ipv4_rules)
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self._setup_spoof_filter_chain(port, self.iptables.ipv6['filter'],
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mac_ipv6_pairs, ipv6_rules)
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def _drop_dhcp_rule(self, ipv4_rules, ipv6_rules):
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#Note(nati) Drop dhcp packet from VM
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ipv4_rules += ['-p udp -m udp --sport 67 --dport 68 -j DROP']
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ipv6_rules += ['-p udp -m udp --sport 547 --dport 546 -j DROP']
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def _accept_inbound_icmpv6(self):
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# Allow multicast listener, neighbor solicitation and
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# neighbor advertisement into the instance
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icmpv6_rules = []
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for icmp6_type in constants.ICMPV6_ALLOWED_TYPES:
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icmpv6_rules += ['-p icmpv6 --icmpv6-type %s -j RETURN' %
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icmp6_type]
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return icmpv6_rules
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def _add_rule_by_security_group(self, port, direction):
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chain_name = self._port_chain_name(port, direction)
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# select rules for current direction
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security_group_rules = self._select_sgr_by_direction(port, direction)
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# split groups by ip version
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# for ipv4, iptables command is used
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# for ipv6, iptables6 command is used
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ipv4_sg_rules, ipv6_sg_rules = self._split_sgr_by_ethertype(
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security_group_rules)
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ipv4_iptables_rule = []
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ipv6_iptables_rule = []
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if direction == EGRESS_DIRECTION:
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self._spoofing_rule(port,
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ipv4_iptables_rule,
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ipv6_iptables_rule)
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self._drop_dhcp_rule(ipv4_iptables_rule, ipv6_iptables_rule)
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if direction == INGRESS_DIRECTION:
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ipv6_iptables_rule += self._accept_inbound_icmpv6()
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ipv4_iptables_rule += self._convert_sgr_to_iptables_rules(
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ipv4_sg_rules)
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ipv6_iptables_rule += self._convert_sgr_to_iptables_rules(
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ipv6_sg_rules)
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self._add_rule_to_chain_v4v6(chain_name,
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ipv4_iptables_rule,
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ipv6_iptables_rule)
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def _convert_sgr_to_iptables_rules(self, security_group_rules):
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iptables_rules = []
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self._drop_invalid_packets(iptables_rules)
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self._allow_established(iptables_rules)
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for rule in security_group_rules:
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# These arguments MUST be in the format iptables-save will
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# display them: source/dest, protocol, sport, dport, target
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# Otherwise the iptables_manager code won't be able to find
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# them to preserve their [packet:byte] counts.
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args = self._ip_prefix_arg('s',
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rule.get('source_ip_prefix'))
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args += self._ip_prefix_arg('d',
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rule.get('dest_ip_prefix'))
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args += self._protocol_arg(rule.get('protocol'))
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args += self._port_arg('sport',
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rule.get('protocol'),
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rule.get('source_port_range_min'),
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rule.get('source_port_range_max'))
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args += self._port_arg('dport',
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rule.get('protocol'),
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rule.get('port_range_min'),
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rule.get('port_range_max'))
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args += ['-j RETURN']
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iptables_rules += [' '.join(args)]
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iptables_rules += ['-j $sg-fallback']
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return iptables_rules
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def _drop_invalid_packets(self, iptables_rules):
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# Always drop invalid packets
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iptables_rules += ['-m state --state ' 'INVALID -j DROP']
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return iptables_rules
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def _allow_established(self, iptables_rules):
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# Allow established connections
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iptables_rules += ['-m state --state RELATED,ESTABLISHED -j RETURN']
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return iptables_rules
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def _protocol_arg(self, protocol):
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if not protocol:
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return []
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iptables_rule = ['-p', protocol]
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# iptables always adds '-m protocol' for udp and tcp
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if protocol in ['udp', 'tcp']:
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iptables_rule += ['-m', protocol]
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return iptables_rule
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def _port_arg(self, direction, protocol, port_range_min, port_range_max):
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if (protocol not in ['udp', 'tcp', 'icmp', 'icmpv6']
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or not port_range_min):
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return []
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if protocol in ['icmp', 'icmpv6']:
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# Note(xuhanp): port_range_min/port_range_max represent
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# icmp type/code when protocol is icmp or icmpv6
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# icmp code can be 0 so we cannot use "if port_range_max" here
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if port_range_max is not None:
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return ['--%s-type' % protocol,
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'%s/%s' % (port_range_min, port_range_max)]
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return ['--%s-type' % protocol, '%s' % port_range_min]
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elif port_range_min == port_range_max:
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return ['--%s' % direction, '%s' % (port_range_min,)]
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else:
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return ['-m', 'multiport',
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'--%ss' % direction,
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'%s:%s' % (port_range_min, port_range_max)]
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def _ip_prefix_arg(self, direction, ip_prefix):
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#NOTE (nati) : source_group_id is converted to list of source_
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# ip_prefix in server side
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if ip_prefix:
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return ['-%s' % direction, ip_prefix]
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return []
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def _port_chain_name(self, port, direction):
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return iptables_manager.get_chain_name(
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'%s%s' % (CHAIN_NAME_PREFIX[direction], port['device'][3:]))
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def filter_defer_apply_on(self):
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if not self._defer_apply:
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self.iptables.defer_apply_on()
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self._pre_defer_filtered_ports = dict(self.filtered_ports)
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self._defer_apply = True
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def filter_defer_apply_off(self):
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if self._defer_apply:
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self._defer_apply = False
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self._remove_chains_apply(self._pre_defer_filtered_ports)
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self._pre_defer_filtered_ports = None
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self._setup_chains_apply(self.filtered_ports)
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self.iptables.defer_apply_off()
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class OVSHybridIptablesFirewallDriver(IptablesFirewallDriver):
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OVS_HYBRID_TAP_PREFIX = 'tap'
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def _port_chain_name(self, port, direction):
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return iptables_manager.get_chain_name(
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'%s%s' % (CHAIN_NAME_PREFIX[direction], port['device']))
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def _get_device_name(self, port):
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return (self.OVS_HYBRID_TAP_PREFIX + port['device'])[:LINUX_DEV_LEN]
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