diff options
Diffstat (limited to 'src/conf_mode/dhcpv6_server.py')
| -rwxr-xr-x | src/conf_mode/dhcpv6_server.py | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/src/conf_mode/dhcpv6_server.py b/src/conf_mode/dhcpv6_server.py new file mode 100755 index 000000000..bb3e6e90d --- /dev/null +++ b/src/conf_mode/dhcpv6_server.py @@ -0,0 +1,451 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2018 VyOS maintainers and contributors +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 or later as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. +# +# + +import sys +import os +import ipaddress + +import jinja2 + +import vyos.validate + +from vyos.config import Config +from vyos import ConfigError + +config_file = r'/etc/dhcp/dhcpd6.conf' +lease_file = r'/config/dhcpd6.leases' +daemon_config_file = r'/etc/default/isc-dhcpv6-server' + +# Please be careful if you edit the template. +config_tmpl = """ +### Autogenerated by dhcpv6_server.py ### + +# For options please consult the following website: +# https://www.isc.org/wp-content/uploads/2017/08/dhcp43options.html + +log-facility local7; +{%- if preference %} +option dhcp6.preference {{ preference }}; +{%- endif %} + +# Shared network configration(s) +{% for network in shared_network %} +{%- if not network.disabled -%} +shared-network {{ network.name }} { + {%- for subnet in network.subnet %} + subnet6 {{ subnet.network }} { + {%- for range in subnet.range6_prefix %} + range6 {{ range.prefix }}{{ " temporary" if range.temporary }}; + {%- endfor %} + {%- for range in subnet.range6 %} + range6 {{ range.start }} {{ range.stop }}; + {%- endfor %} + {%- if subnet.domain_search %} + option dhcp6.domain-search {{ subnet.domain_search | join(', ') }}; + {%- endif %} + {%- if subnet.lease_def %} + default-lease-time {{ subnet.lease_def }}; + {%- endif %} + {%- if subnet.lease_max %} + max-lease-time {{ subnet.lease_max }}; + {%- endif %} + {%- if subnet.lease_min %} + min-lease-time {{ subnet.lease_min }}; + {%- endif %} + {%- if subnet.dns_server %} + option dhcp6.name-servers {{ subnet.dns_server | join(', ') }}; + {%- endif %} + {%- if subnet.nis_domain %} + option dhcp6.nis-domain-name "{{ subnet.nis_domain }}"; + {%- endif %} + {%- if subnet.nis_server %} + option dhcp6.nis-servers {{ subnet.nis_server | join(', ') }}; + {%- endif %} + {%- if subnet.nisp_domain %} + option dhcp6.nisp-domain-name "{{ subnet.nisp_domain }}"; + {%- endif %} + {%- if subnet.nisp_server %} + option dhcp6.nisp-servers {{ subnet.nisp_server | join(', ') }}; + {%- endif %} + {%- if subnet.sip_address %} + option dhcp6.sip-servers-addresses {{ subnet.sip_address | join(', ') }}; + {%- endif %} + {%- if subnet.sip_hostname %} + option dhcp6.sip-servers-names {{ subnet.sip_hostname | join(', ') }}; + {%- endif %} + {%- if subnet.sntp_server %} + option dhcp6.sntp-servers {{ subnet.sntp_server | join(', ') }}; + {%- endif %} + {%- for host in subnet.static_mapping %} + {% if not host.disabled -%} + host {{ network.name }}_{{ host.name }} { + host-identifier option dhcp6.client-id "{{ host.client_identifier }}"; + fixed-address6 {{ host.ipv6_address }}; + } + {%- endif %} + {%- endfor %} + } + {%- endfor %} +} +{%- endif %} +{% endfor %} + +""" + +daemon_tmpl = """ +### Autogenerated by dhcp_server.py ### + +# sourced by /etc/init.d/isc-dhcpv6-server + +DHCPD_CONF=/etc/dhcp/dhcpd6.conf +DHCPD_PID=/var/run/dhcpd6.pid +OPTIONS="-6 -lf {{ lease_file }}" +INTERFACES="" +""" + +default_config_data = { + 'lease_file': lease_file, + 'preference': '', + 'disabled': False, + 'shared_network': [] +} + +def get_config(): + dhcpv6 = default_config_data + conf = Config() + if not conf.exists('service dhcpv6-server'): + return None + else: + conf.set_level('service dhcpv6-server') + + # Check for global disable of DHCPv6 service + if conf.exists('disable'): + dhcpv6['disabled'] = True + return dhcpv6 + + # Preference of this DHCPv6 server compared with others + if conf.exists('preference'): + dhcpv6['preference'] = conf.return_value('preference') + + # check for multiple, shared networks served with DHCPv6 addresses + if conf.exists('shared-network-name'): + for network in conf.list_nodes('shared-network-name'): + conf.set_level('service dhcpv6-server shared-network-name {0}'.format(network)) + config = { + 'name': network, + 'disabled': False, + 'subnet': [] + } + + # If disabled, the shared-network configuration becomes inactive + if conf.exists('disable'): + config['disabled'] = True + + # check for multiple subnet configurations in a shared network + if conf.exists('subnet'): + for net in conf.list_nodes('subnet'): + conf.set_level('service dhcpv6-server shared-network-name {0} subnet {1}'.format(network, net)) + subnet = { + 'network': net, + 'range6_prefix': [], + 'range6': [], + 'default_router': '', + 'dns_server': [], + 'domain_name': '', + 'domain_search': [], + 'lease_def': '', + 'lease_min': '', + 'lease_max': '', + 'nis_domain': '', + 'nis_server': [], + 'nisp_domain': '', + 'nisp_server': [], + 'sip_address': [], + 'sip_hostname': [], + 'sntp_server': [], + 'static_mapping': [] + } + + # For any subnet on which addresses will be assigned dynamically, there must be at + # least one address range statement. The range statement gives the lowest and highest + # IP addresses in a range. All IP addresses in the range should be in the subnet in + # which the range statement is declared. + if conf.exists('address-range prefix'): + for prefix in conf.list_nodes('address-range prefix'): + range = { + 'prefix': prefix, + 'temporary': False + } + + # Address range will be used for temporary addresses + if conf.exists('address-range prefix {0} temporary'.format(range['prefix'])): + range['temporary'] = True + + # Append to subnet temporary range6 list + subnet['range6_prefix'].append(range) + + if conf.exists('address-range start'): + for range in conf.list_nodes('address-range start'): + range = { + 'start': range, + 'stop': conf.return_value('address-range start {0} stop'.format(range)) + } + + # Append to subnet range6 list + subnet['range6'].append(range) + + # The domain-search option specifies a 'search list' of Domain Names to be used + # by the client to locate not-fully-qualified domain names. + if conf.exists('domain-search'): + for domain in conf.return_values('domain-search'): + subnet['domain_search'].append('"' + domain + '"') + + # IPv6 address valid lifetime + # (at the end the address is no longer usable by the client) + # (set to 30 days, the usual IPv6 default) + if conf.exists('lease-time default'): + subnet['lease_def'] = conf.return_value('lease-time default') + + # Time should be the maximum length in seconds that will be assigned to a lease. + # The only exception to this is that Dynamic BOOTP lease lengths, which are not + # specified by the client, are not limited by this maximum. + if conf.exists('lease-time maximum'): + subnet['lease_max'] = conf.return_value('lease-time maximum') + + # Time should be the minimum length in seconds that will be assigned to a lease + if conf.exists('lease-time minimum'): + subnet['lease_min'] = conf.return_value('lease-time minimum') + + # Specifies a list of Domain Name System name servers available to the client. + # Servers should be listed in order of preference. + if conf.exists('name-server'): + subnet['dns_server'] = conf.return_values('name-server') + + # Ancient NIS (Network Information Service) domain name + if conf.exists('nis-domain'): + subnet['nis_domain'] = conf.return_value('nis-domain') + + # Ancient NIS (Network Information Service) servers + if conf.exists('nis-server'): + subnet['nis_server'] = conf.return_values('nis-server') + + # Ancient NIS+ (Network Information Service) domain name + if conf.exists('nisplus-domain'): + subnet['nisp_domain'] = conf.return_value('nisplus-domain') + + # Ancient NIS+ (Network Information Service) servers + if conf.exists('nisplus-server'): + subnet['nisp_server'] = conf.return_values('nisplus-server') + + # Prefix Delegation (RFC 3633) + if conf.exists('prefix-delegation'): + print('TODO: This option is actually not implemented right now!') + + # Local SIP server that is to be used for all outbound SIP requests - IPv6 address + if conf.exists('sip-server-address'): + subnet['sip_address'] = conf.return_values('sip-server-address') + + # Local SIP server that is to be used for all outbound SIP requests - hostname + if conf.exists('sip-server-name'): + for hostname in conf.return_values('sip-server-name'): + subnet['sip_hostname'].append('"' + hostname + '"') + + # List of local SNTP servers available for the client to synchronize their clocks + if conf.exists('sntp-server'): + subnet['sntp_server'] = conf.return_values('sntp-server') + + # + # Static DHCP v6 leases + # + if conf.exists('static-mapping'): + for mapping in conf.list_nodes('static-mapping'): + conf.set_level('service dhcpv6-server shared-network-name {0} subnet {1} static-mapping {2}'.format(network, net, mapping)) + mapping = { + 'name': mapping, + 'disabled': False, + 'ipv6_address': '', + 'client_identifier': '', + } + + # This static lease is disabled + if conf.exists('disable'): + mapping['disabled'] = True + + # IPv6 address used for this DHCP client + if conf.exists('ipv6-address'): + mapping['ipv6_address'] = conf.return_value('ipv6-address') + + # This option specifies the client’s DUID identifier. DUIDs are similar but different from DHCPv4 client identifiers + if conf.exists('identifier'): + mapping['client_identifier'] = conf.return_value('identifier') + + # append static mapping configuration tu subnet list + subnet['static_mapping'].append(mapping) + + # append subnet configuration to shared network subnet list + config['subnet'].append(subnet) + + + # append shared network configuration to config dictionary + dhcpv6['shared_network'].append(config) + + return dhcpv6 + +def verify(dhcpv6): + if dhcpv6 is None: + return None + + if dhcpv6['disabled']: + return None + + # If DHCP is enabled we need one share-network + if len(dhcpv6['shared_network']) == 0: + raise ConfigError('No DHCPv6 shared networks configured.\n' \ + 'At least one DHCPv6 shared network must be configured.') + + # Inspect shared-network/subnet + subnets = [] + listen_ok = False + + for network in dhcpv6['shared_network']: + # A shared-network requires a subnet definition + if len(network['subnet']) == 0: + raise ConfigError('No DHCPv6 lease subnets configured for {0}. At least one\n' \ + 'lease subnet must be configured for each shared network.'.format(network['name'])) + + range6_start = [] + range6_stop = [] + for subnet in network['subnet']: + # Ususal range declaration with a start and stop address + for range6 in subnet['range6']: + # shorten names + start = range6['start'] + stop = range6['stop'] + + # DHCPv6 stop address is required + if start and not stop: + raise ConfigError('DHCPv6 range stop address for start {0} is not defined!'.format(start)) + + # Start address must be inside network + if not ipaddress.ip_address(start) in ipaddress.ip_network(subnet['network']): + raise ConfigError('DHCPv6 range start address {0} is not in subnet {1}\n' \ + 'specified for shared network {2}!'.format(start, subnet['network'], network['name'])) + + # Stop address must be inside network + if not ipaddress.ip_address(stop) in ipaddress.ip_network(subnet['network']): + raise ConfigError('DHCPv6 range stop address {0} is not in subnet {1}\n' \ + 'specified for shared network {2}!'.format(stop, subnet['network'], network['name'])) + + # Stop address must be greater or equal to start address + if not ipaddress.ip_address(stop) >= ipaddress.ip_address(start): + raise ConfigError('DHCPv6 range stop address {0} must be greater or equal\n' \ + 'to the range start address {1}!'.format(stop, start)) + + # DHCPv6 range start address must be unique - two ranges can't + # start with the same address - makes no sense + if start in range6_start: + raise ConfigError('Conflicting DHCPv6 lease range:\n' \ + 'Pool start address {0} defined multipe times!'.format(start)) + else: + range6_start.append(start) + + # DHCPv6 range stop address must be unique - two ranges can't + # end with the same address - makes no sense + if stop in range6_stop: + raise ConfigError('Conflicting DHCPv6 lease range:\n' \ + 'Pool stop address {0} defined multipe times!'.format(stop)) + else: + range6_stop.append(stop) + + # We also have prefixes that require checking + for prefix in subnet['range6_prefix']: + # If configured prefix does not match our subnet, we have to check that it's inside + if ipaddress.ip_network(prefix['prefix']) != ipaddress.ip_network(subnet['network']): + # Configured prefixes must be inside our network + if not ipaddress.ip_network(prefix['prefix']) in ipaddress.ip_network(subnet['network']): + raise ConfigError('DHCPv6 prefix {0} is not in subnet {1}\n' \ + 'specified for shared network {2}!'.format(prefix['prefix'], subnet['network'], network['name'])) + + # DHCPv6 requires at least one configured address range or one static mapping + if not network['disabled']: + if vyos.validate.is_subnet_connected(subnet['network']): + listen_ok = True + + # DHCPv6 subnet must not overlap. ISC DHCP also complains about overlapping + # subnets: "Warning: subnet 2001:db8::/32 overlaps subnet 2001:db8:1::/32" + net = ipaddress.ip_network(subnet['network']) + for n in subnets: + net2 = ipaddress.ip_network(n) + if (net != net2): + if net.overlaps(net2): + raise ConfigError('DHCPv6 conflicting subnet ranges: {0} overlaps {1}'.format(net, net2)) + + if not listen_ok: + raise ConfigError('None of the DHCPv6 subnets are connected to a subnet6 on\n' \ + 'this machine. At least one subnet6 must be connected such that\n' \ + 'DHCPv6 listens on an interface!') + + + return None + +def generate(dhcpv6): + if dhcpv6 is None: + return None + + if dhcpv6['disabled']: + print('Warning: DHCPv6 server will be deactivated because it is disabled') + return None + + tmpl = jinja2.Template(config_tmpl) + config_text = tmpl.render(dhcpv6) + with open(config_file, 'w') as f: + f.write(config_text) + + tmpl = jinja2.Template(daemon_tmpl) + config_text = tmpl.render(dhcpv6) + with open(daemon_config_file, 'w') as f: + f.write(config_text) + + return None + +def apply(dhcpv6): + if (dhcpv6 is None) or dhcpv6['disabled']: + # DHCP server is removed in the commit + os.system('sudo systemctl stop isc-dhcpv6-server.service') + if os.path.exists(config_file): + os.unlink(config_file) + if os.path.exists(daemon_config_file): + os.unlink(daemon_config_file) + else: + # If our file holding DHCPv6 leases does yet not exist - create it + if not os.path.exists(lease_file): + os.mknod(lease_file) + + os.system('sudo systemctl restart isc-dhcpv6-server.service') + + return None + +if __name__ == '__main__': + try: + c = get_config() + verify(c) + generate(c) + apply(c) + except ConfigError as e: + print(e) + sys.exit(1) |