From 84b7ade286e4022e62684237246cd04b9d37b5db Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Tue, 1 Dec 2020 18:18:09 +0100 Subject: dhcp: T3100: migrate server configuration to get_config_dict() --- src/conf_mode/dhcp_server.py | 576 +++++++++---------------------------------- 1 file changed, 113 insertions(+), 463 deletions(-) (limited to 'src') diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py index fd4e2ec61..6df9d4a25 100755 --- a/src/conf_mode/dhcp_server.py +++ b/src/conf_mode/dhcp_server.py @@ -16,32 +16,22 @@ import os -from ipaddress import ip_address, ip_network -from socket import inet_ntoa -from struct import pack +from ipaddress import ip_address +from ipaddress import ip_network from sys import exit from vyos.config import Config +from vyos.configdict import dict_merge +from vyos.template import render +from vyos.util import call +from vyos.util import dict_search from vyos.validate import is_subnet_connected +from vyos.xml import defaults from vyos import ConfigError -from vyos.template import render -from vyos.util import call, chown - from vyos import airbag airbag.enable() -config_file = r'/run/dhcp-server/dhcpd.conf' - -default_config_data = { - 'disabled': False, - 'ddns_enable': False, - 'global_parameters': [], - 'hostfile_update': False, - 'host_decl_name': False, - 'static_route': False, - 'wpad': False, - 'shared_network': [], -} +config_file = '/run/dhcp-server/dhcpd.conf' def dhcp_slice_range(exclude_list, range_list): """ @@ -106,356 +96,37 @@ def dhcp_slice_range(exclude_list, range_list): return output -def dhcp_static_route(static_subnet, static_router): - # https://ercpe.de/blog/pushing-static-routes-with-isc-dhcp-server - # Option format is: - # , , , , , , - # where bytes with the value 0 are omitted. - net = ip_network(static_subnet) - # add netmask - string = str(net.prefixlen) + ',' - # add network bytes - if net.prefixlen: - width = net.prefixlen // 8 - if net.prefixlen % 8: - width += 1 - string += ','.join(map(str,tuple(net.network_address.packed)[:width])) + ',' - - # add router bytes - string += ','.join(static_router.split('.')) - - return string - def get_config(config=None): - dhcp = default_config_data if config: conf = config else: conf = Config() - if not conf.exists('service dhcp-server'): + + base = ['service', 'dhcp-server'] + if not conf.exists(base): return None - else: - conf.set_level('service dhcp-server') - - # check for global disable of DHCP service - if conf.exists('disable'): - dhcp['disabled'] = True - - # check for global dynamic DNS upste - if conf.exists('dynamic-dns-update'): - dhcp['ddns_enable'] = True - - # HACKS AND TRICKS - # - # check for global 'raw' ISC DHCP parameters configured by users - # actually this is a bad idea in general to pass raw parameters from any user - if conf.exists('global-parameters'): - dhcp['global_parameters'] = conf.return_values('global-parameters') - - # check for global DHCP server updating /etc/host per lease - if conf.exists('hostfile-update'): - dhcp['hostfile_update'] = True - - # If enabled every host declaration within that scope, the name provided - # for the host declaration will be supplied to the client as its hostname. - if conf.exists('host-decl-name'): - dhcp['host_decl_name'] = True - - # check for multiple, shared networks served with DHCP addresses - if conf.exists('shared-network-name'): - for network in conf.list_nodes('shared-network-name'): - conf.set_level('service dhcp-server shared-network-name {0}'.format(network)) - config = { - 'name': network, - 'authoritative': False, - 'description': '', - 'disabled': False, - 'network_parameters': [], - 'subnet': [] - } - # check if DHCP server should be authoritative on this network - if conf.exists('authoritative'): - config['authoritative'] = True - - # A description for this given network - if conf.exists('description'): - config['description'] = conf.return_value('description') - - # If disabled, the shared-network configuration becomes inactive in - # the running DHCP server instance - if conf.exists('disable'): - config['disabled'] = True - - # HACKS AND TRICKS - # - # check for 'raw' ISC DHCP parameters configured by users - # actually this is a bad idea in general to pass raw parameters - # from any user - # - # deprecate this and issue a warning like we do for DNS forwarding? - if conf.exists('shared-network-parameters'): - config['network_parameters'] = conf.return_values('shared-network-parameters') - - # check for multiple subnet configurations in a shared network - # config segment - if conf.exists('subnet'): - for net in conf.list_nodes('subnet'): - conf.set_level('service dhcp-server shared-network-name {0} subnet {1}'.format(network, net)) - subnet = { - 'network': net, - 'address': str(ip_network(net).network_address), - 'netmask': str(ip_network(net).netmask), - 'bootfile_name': '', - 'bootfile_server': '', - 'client_prefix_length': '', - 'default_router': '', - 'rfc3442_default_router': '', - 'dns_server': [], - 'domain_name': '', - 'domain_search': [], - 'exclude': [], - 'failover_local_addr': '', - 'failover_name': '', - 'failover_peer_addr': '', - 'failover_status': '', - 'ip_forwarding': False, - 'lease': '86400', - 'ntp_server': [], - 'pop_server': [], - 'server_identifier': '', - 'smtp_server': [], - 'range': [], - 'static_mapping': [], - 'static_subnet': '', - 'static_router': '', - 'static_route': '', - 'subnet_parameters': [], - 'tftp_server': '', - 'time_offset': '', - 'time_server': [], - 'wins_server': [], - 'wpad_url': '' - } - # Used to identify a bootstrap file - if conf.exists('bootfile-name'): - subnet['bootfile_name'] = conf.return_value('bootfile-name') - - # Specify host address of the server from which the initial boot file - # (specified above) is to be loaded. Should be a numeric IP address or - # domain name. - if conf.exists('bootfile-server'): - subnet['bootfile_server'] = conf.return_value('bootfile-server') - - # The subnet mask option specifies the client's subnet mask as per RFC 950. If no subnet - # mask option is provided anywhere in scope, as a last resort dhcpd will use the subnet - # mask from the subnet declaration for the network on which an address is being assigned. - if conf.exists('client-prefix-length'): - # snippet borrowed from https://stackoverflow.com/questions/33750233/convert-cidr-to-subnet-mask-in-python - host_bits = 32 - int(conf.return_value('client-prefix-length')) - subnet['client_prefix_length'] = inet_ntoa(pack('!I', (1 << 32) - (1 << host_bits))) - - # Default router IP address on the client's subnet - if conf.exists('default-router'): - subnet['default_router'] = conf.return_value('default-router') - subnet['rfc3442_default_router'] = dhcp_static_route("0.0.0.0/0", subnet['default_router']) - - # Specifies a list of Domain Name System (STD 13, RFC 1035) name servers available to - # the client. Servers should be listed in order of preference. - if conf.exists('dns-server'): - subnet['dns_server'] = conf.return_values('dns-server') - - # Option specifies the domain name that client should use when resolving hostnames - # via the Domain Name System. - if conf.exists('domain-name'): - subnet['domain_name'] = conf.return_value('domain-name') - - # 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 + '"') - - # IP address (local) for failover peer to connect - if conf.exists('failover local-address'): - subnet['failover_local_addr'] = conf.return_value('failover local-address') - - # DHCP failover peer name - if conf.exists('failover name'): - subnet['failover_name'] = conf.return_value('failover name') - - # IP address (remote) of failover peer - if conf.exists('failover peer-address'): - subnet['failover_peer_addr'] = conf.return_value('failover peer-address') - - # DHCP failover peer status (primary|secondary) - if conf.exists('failover status'): - subnet['failover_status'] = conf.return_value('failover status') - - # Option specifies whether the client should configure its IP layer for packet - # forwarding - if conf.exists('ip-forwarding'): - subnet['ip_forwarding'] = True - - # Time should be the length in seconds that will be assigned to a lease if the - # client requesting the lease does not ask for a specific expiration time - if conf.exists('lease'): - subnet['lease'] = conf.return_value('lease') - - # Specifies a list of IP addresses indicating NTP (RFC 5905) servers available - # to the client. - if conf.exists('ntp-server'): - subnet['ntp_server'] = conf.return_values('ntp-server') - - # POP3 server option specifies a list of POP3 servers available to the client. - # Servers should be listed in order of preference. - if conf.exists('pop-server'): - subnet['pop_server'] = conf.return_values('pop-server') - - # DHCP servers include this option in the DHCPOFFER in order to allow the client - # to distinguish between lease offers. DHCP clients use the contents of the - # 'server identifier' field as the destination address for any DHCP messages - # unicast to the DHCP server - if conf.exists('server-identifier'): - subnet['server_identifier'] = conf.return_value('server-identifier') - - # SMTP server option specifies a list of SMTP servers available to the client. - # Servers should be listed in order of preference. - if conf.exists('smtp-server'): - subnet['smtp_server'] = conf.return_values('smtp-server') - - # For any subnet on which addresses will be assigned dynamically, there must be at - # least one 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('range'): - for range in conf.list_nodes('range'): - range = { - 'start': conf.return_value('range {0} start'.format(range)), - 'stop': conf.return_value('range {0} stop'.format(range)) - } - subnet['range'].append(range) - - # IP address that needs to be excluded from DHCP lease range - if conf.exists('exclude'): - subnet['exclude'] = conf.return_values('exclude') - subnet['range'] = dhcp_slice_range(subnet['exclude'], subnet['range']) - - # Static DHCP leases - if conf.exists('static-mapping'): - addresses_for_exclude = [] - for mapping in conf.list_nodes('static-mapping'): - conf.set_level('service dhcp-server shared-network-name {0} subnet {1} static-mapping {2}'.format(network, net, mapping)) - mapping = { - 'name': mapping, - 'disabled': False, - 'ip_address': '', - 'mac_address': '', - 'static_parameters': [] - } - - # This static lease is disabled - if conf.exists('disable'): - mapping['disabled'] = True - - # IP address used for this DHCP client - if conf.exists('ip-address'): - mapping['ip_address'] = conf.return_value('ip-address') - addresses_for_exclude.append(mapping['ip_address']) - - # MAC address of requesting DHCP client - if conf.exists('mac-address'): - mapping['mac_address'] = conf.return_value('mac-address') - - # HACKS AND TRICKS - # - # check for 'raw' ISC DHCP parameters configured by users - # actually this is a bad idea in general to pass raw parameters - # from any user - # - # deprecate this and issue a warning like we do for DNS forwarding? - if conf.exists('static-mapping-parameters'): - mapping['static_parameters'] = conf.return_values('static-mapping-parameters') - - # append static-mapping configuration to subnet list - subnet['static_mapping'].append(mapping) - - # Now we have all static DHCP leases - we also need to slice them - # out of our DHCP ranges to avoid ISC DHCPd warnings as: - # dhcpd: Dynamic and static leases present for 192.0.2.51. - # dhcpd: Remove host declaration DMZ_PC1 or remove 192.0.2.51 - # dhcpd: from the dynamic address pool for DMZ - subnet['range'] = dhcp_slice_range(addresses_for_exclude, subnet['range']) - - # Reset config level to matching hirachy - conf.set_level('service dhcp-server shared-network-name {0} subnet {1}'.format(network, net)) - - # This option specifies a list of static routes that the client should install in its routing - # cache. If multiple routes to the same destination are specified, they are listed in descending - # order of priority. - if conf.exists('static-route destination-subnet'): - subnet['static_subnet'] = conf.return_value('static-route destination-subnet') - # Required for global config section - dhcp['static_route'] = True - - if conf.exists('static-route router'): - subnet['static_router'] = conf.return_value('static-route router') - - if subnet['static_router'] and subnet['static_subnet']: - subnet['static_route'] = dhcp_static_route(subnet['static_subnet'], subnet['static_router']) - - # HACKS AND TRICKS - # - # check for 'raw' ISC DHCP parameters configured by users - # actually this is a bad idea in general to pass raw parameters - # from any user - # - # deprecate this and issue a warning like we do for DNS forwarding? - if conf.exists('subnet-parameters'): - subnet['subnet_parameters'] = conf.return_values('subnet-parameters') - - # This option is used to identify a TFTP server and, if supported by the client, should have - # the same effect as the server-name declaration. BOOTP clients are unlikely to support this - # option. Some DHCP clients will support it, and others actually require it. - if conf.exists('tftp-server-name'): - subnet['tftp_server'] = conf.return_value('tftp-server-name') - - # The time-offset option specifies the offset of the client’s subnet in seconds from - # Coordinated Universal Time (UTC). - if conf.exists('time-offset'): - subnet['time_offset'] = conf.return_value('time-offset') - - # The time-server option specifies a list of RFC 868 time servers available to the client. - # Servers should be listed in order of preference. - if conf.exists('time-server'): - subnet['time_server'] = conf.return_values('time-server') - - # The NetBIOS name server (NBNS) option specifies a list of RFC 1001/1002 NBNS name servers - # listed in order of preference. NetBIOS Name Service is currently more commonly referred to - # as WINS. WINS servers can be specified using the netbios-name-servers option. - if conf.exists('wins-server'): - subnet['wins_server'] = conf.return_values('wins-server') - - # URL for Web Proxy Autodiscovery Protocol - if conf.exists('wpad-url'): - subnet['wpad_url'] = conf.return_value('wpad-url') - # Required for global config section - dhcp['wpad'] = True - - # append subnet configuration to shared network subnet list - config['subnet'].append(subnet) - - # append shared network configuration to config dictionary - dhcp['shared_network'].append(config) + dhcp = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True) + + # T2665: defaults include lease time per TAG node which need to be added to + # individual subnet definitions + default_values = defaults(base + ['shared-network-name', 'subnet']) + for network, network_config in (dict_search('shared_network_name', dhcp).items() or {}): + print(network) + for subnet, subnet_config in (dict_search('subnet', network_config).items() or {}): + if 'lease' not in subnet_config: + dhcp['shared_network_name'][network]['subnet'][subnet] = dict_merge( + default_values, dhcp['shared_network_name'][network]['subnet'][subnet]) return dhcp def verify(dhcp): - if not dhcp or dhcp['disabled']: + # bail out early - looks like removal from running config + if not dhcp or 'disable' in dhcp: return None # If DHCP is enabled we need one share-network - if len(dhcp['shared_network']) == 0: + if 'shared_network_name' not in dhcp: raise ConfigError('No DHCP shared networks configured.\n' \ 'At least one DHCP shared network must be configured.') @@ -465,139 +136,117 @@ def verify(dhcp): subnets = [] # A shared-network requires a subnet definition - for network in dhcp['shared_network']: - if len(network['subnet']) == 0: - raise ConfigError('No DHCP lease subnets configured for {0}. At least one\n' \ - 'lease subnet must be configured for each shared network.'.format(network['name'])) - - for subnet in network['subnet']: - # Subnet static route declaration requires destination and router - if subnet['static_subnet'] or subnet['static_router']: - if not (subnet['static_subnet'] and subnet['static_router']): - raise ConfigError('Please specify missing DHCP static-route parameter(s):\n' \ - 'destination-subnet | router') - - # Failover requires all 4 parameters set - if subnet['failover_local_addr'] or subnet['failover_peer_addr'] or subnet['failover_name'] or subnet['failover_status']: - if not (subnet['failover_local_addr'] and subnet['failover_peer_addr'] and subnet['failover_name'] and subnet['failover_status']): - raise ConfigError('Please specify missing DHCP failover parameter(s):\n' \ - 'local-address | peer-address | name | status') + for network, network_config in dhcp['shared_network_name'].items(): + if 'subnet' not in network_config: + raise ConfigError(f'No subnets defined for {network}. At least one\n' \ + 'lease subnet must be configured.') + + for subnet, subnet_config in network_config['subnet'].items(): + if 'static_route' in subnet_config and len(subnet_config['static_route']) != 2: + raise ConfigError('Missing DHCP static-route parameter(s):\n' \ + 'destination-subnet | router must be defined!') + + # Check if DHCP address range is inside configured subnet declaration + if 'range' in subnet_config: + range_start = [] + range_stop = [] + for range, range_config in subnet_config['range'].items(): + if not {'start', 'stop'} <= set(range_config): + raise ConfigError(f'DHCP range "{range}" start and stop address must be defined!') + + # Start/Stop address must be inside network + for key in ['start', 'stop']: + if ip_address(range_config[key]) not in ip_network(subnet): + raise ConfigError(f'DHCP range "{range}" {key} address not within shared-network "{network}, {subnet}"!') + + # Stop address must be greater or equal to start address + if ip_address(range_config['stop']) < ip_address(range_config['start']): + raise ConfigError(f'DHCP range "{range}" stop address must be greater or equal\n' \ + 'to the ranges start address!') + + # Range start address must be unique + if range_config['start'] in range_start: + raise ConfigError('Conflicting DHCP lease range: Pool start\n' \ + 'address "{start}" defined multipe times!'.format(range_config)) + + # Range stop address must be unique + if range_config['stop'] in range_start: + raise ConfigError('Conflicting DHCP lease range: Pool stop\n' \ + 'address "{stop}" defined multipe times!'.format(range_config)) + + range_start.append(range_config['start']) + range_stop.append(range_config['stop']) + + if 'failover' in subnet_config: + for key in ['local_address', 'peer_address', 'name', 'status']: + if key not in subnet_config['failover']: + raise ConfigError(f'Missing DHCP failover parameter "{key}"!') # Failover names must be uniquie - if subnet['failover_name'] in failover_names: - raise ConfigError('Failover names must be unique:\n' \ - '{0} has already been configured!'.format(subnet['failover_name'])) - else: - failover_names.append(subnet['failover_name']) + if subnet_config['failover']['name'] in failover_names: + name = subnet_config['failover']['name'] + raise ConfigError(f'DHCP failover names must be unique:\n' \ + f'{name} has already been configured!') + failover_names.append(subnet_config['failover']['name']) # Failover requires start/stop ranges for pool - if (len(subnet['range']) == 0): - raise ConfigError('At least one start-stop range must be configured for {0}\n' \ - 'to set up DHCP failover!'.format(subnet['network'])) - - # Check if DHCP address range is inside configured subnet declaration - range_start = [] - range_stop = [] - for range in subnet['range']: - start = range['start'] - stop = range['stop'] - # DHCP stop IP required after start IP - if start and not stop: - raise ConfigError('DHCP range stop address for start {0} is not defined!'.format(start)) - - # Start address must be inside network - if not ip_address(start) in ip_network(subnet['network']): - raise ConfigError('DHCP 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 ip_address(stop) in ip_network(subnet['network']): - raise ConfigError('DHCP 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 ip_address(stop) >= ip_address(start): - raise ConfigError('DHCP range stop address {0} must be greater or equal\n' \ - 'to the range start address {1}!'.format(stop, start)) - - # Range start address must be unique - if start in range_start: - raise ConfigError('Conflicting DHCP lease range:\n' \ - 'Pool start address {0} defined multipe times!'.format(start)) - else: - range_start.append(start) - - # Range stop address must be unique - if stop in range_stop: - raise ConfigError('Conflicting DHCP lease range:\n' \ - 'Pool stop address {0} defined multipe times!'.format(stop)) - else: - range_stop.append(stop) + if 'range' not in subnet_config: + raise ConfigError(f'DHCP failover requires at least one start-stop range to be configured\n'\ + f'within shared-network "{network}, {subnet}" for using failover!') # Exclude addresses must be in bound - for exclude in subnet['exclude']: - if not ip_address(exclude) in ip_network(subnet['network']): - raise ConfigError('Exclude IP address {0} is outside of the DHCP lease network {1}\n' \ - 'under shared network {2}!'.format(exclude, subnet['network'], network['name'])) + if 'exclude' in subnet_config: + for exclude in subnet_config['exclude']: + if ip_address(exclude) not in ip_network(subnet): + raise ConfigError(f'Excluded IP address "{exclude}" not within shared-network "{network}, {subnet}"!') # At least one DHCP address range or static-mapping required - active_mapping = False - if (len(subnet['range']) == 0): - for mapping in subnet['static_mapping']: - # we need at least one active mapping - if (not active_mapping) and (not mapping['disabled']): - active_mapping = True - else: - active_mapping = True - - if not active_mapping: - raise ConfigError('No DHCP address range or active static-mapping set\n' \ - 'for subnet {0}!'.format(subnet['network'])) - - # Static mappings require just a MAC address (will use an IP from the dynamic pool if IP is not set) - for mapping in subnet['static_mapping']: - - if mapping['ip_address']: - # Static IP address must be in bound - if not ip_address(mapping['ip_address']) in ip_network(subnet['network']): - raise ConfigError('DHCP static lease IP address {0} for static mapping {1}\n' \ - 'in shared network {2} is outside DHCP lease subnet {3}!' \ - .format(mapping['ip_address'], mapping['name'], network['name'], subnet['network'])) - - # Static mapping requires MAC address - if not mapping['mac_address']: - raise ConfigError('DHCP static lease MAC address not specified for static mapping\n' \ - '{0} under shared network name {1}!'.format(mapping['name'], network['name'])) + if 'range' not in subnet_config and 'static_mapping' not in subnet_config: + raise ConfigError(f'No DHCP address range or active static-mapping configured\n' \ + f'within shared-network "{network}, {subnet}"!') + + if 'static_mapping' in subnet_config: + # Static mappings require just a MAC address (will use an IP from the dynamic pool if IP is not set) + for mapping, mapping_config in subnet_config['static_mapping'].items(): + if 'ip_address' in mapping_config: + if ip_address(mapping_config['ip_address']) not in ip_network(subnet): + raise ConfigError(f'Configured static lease address for mapping "{mapping}" is\n' \ + f'not within shared-network "{network}, {subnet}"!') + + if 'mac_address' not in mapping_config: + raise ConfigError(f'MAC address required for static mapping "{mapping}"\n' \ + f'within shared-network "{network}, {subnet}"!') # There must be one subnet connected to a listen interface. # This only counts if the network itself is not disabled! - if not network['disabled']: - if is_subnet_connected(subnet['network'], primary=True): + if 'disable' not in network_config: + if is_subnet_connected(subnet, primary=True): listen_ok = True # Subnets must be non overlapping - if subnet['network'] in subnets: - raise ConfigError('DHCP subnets must be unique! Subnet {0} defined multiple times!'.format(subnet['network'])) - else: - subnets.append(subnet['network']) + if subnet in subnets: + raise ConfigError(f'Configured subnets must be unique! Subnet "{subnet}"\n' + 'defined multiple times!') + subnets.append(subnet) # Check for overlapping subnets - net = ip_network(subnet['network']) + net = ip_network(subnet) for n in subnets: net2 = ip_network(n) if (net != net2): if net.overlaps(net2): - raise ConfigError('DHCP conflicting subnet ranges: {0} overlaps {1}'.format(net, net2)) + raise ConfigError('Conflicting subnet ranges: "{net}" overlaps "{net2}"!') if not listen_ok: - raise ConfigError('DHCP server configuration error!\n' \ - 'None of configured DHCP subnets does not have appropriate\n' \ - 'primary IP address on any broadcast interface.') + raise ConfigError('DHCP server configuration error! None of the configured\n' \ + 'subnets have an appropriate primary IP address on any\n' + 'broadcast interface.') return None def generate(dhcp): - if not dhcp or dhcp['disabled']: + # bail out early - looks like removal from running config + if not dhcp or 'disable' in dhcp: return None # Please see: https://phabricator.vyos.net/T1129 for quoting of the raw parameters @@ -607,11 +256,12 @@ def generate(dhcp): return None def apply(dhcp): - if not dhcp or dhcp['disabled']: - # DHCP server is removed in the commit + # bail out early - looks like removal from running config + if not dhcp or 'disable' in dhcp: call('systemctl stop isc-dhcp-server.service') if os.path.exists(config_file): os.unlink(config_file) + return None call('systemctl restart isc-dhcp-server.service') -- cgit v1.2.3