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authorChristian Poessinger <christian@poessinger.com>2018-08-27 23:12:09 +0200
committerChristian Poessinger <christian@poessinger.com>2018-08-27 23:12:09 +0200
commitbe6f4cf0804fa7f865dfc5dd6d9faaba22b0e149 (patch)
tree1e484127500ed3fbf4371ff15bfaffa5392c7bac /src/conf_mode/dhcp_server.py
parent0d29db14c7ccbbd3b48a02678fb8cd4f3649fd48 (diff)
parent77c1b3457439889846380c5fd5da30cd11e253d9 (diff)
downloadvyos-1x-be6f4cf0804fa7f865dfc5dd6d9faaba22b0e149.tar.gz
vyos-1x-be6f4cf0804fa7f865dfc5dd6d9faaba22b0e149.zip
Merge branch 'dhcp-server-rewrite' into current
Diffstat (limited to 'src/conf_mode/dhcp_server.py')
-rwxr-xr-xsrc/conf_mode/dhcp_server.py773
1 files changed, 773 insertions, 0 deletions
diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py
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+++ b/src/conf_mode/dhcp_server.py
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+#!/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 socket
+import struct
+import netifaces
+
+from vyos.config import Config
+from vyos import ConfigError
+
+config_file = r'/etc/dhcp/dhcpd.conf'
+daemon_config_file = r'/etc/default/isc-dhcp-server'
+
+# Please be careful if you edit the template.
+config_tmpl = """
+### Autogenerated by dhcp_server.py ###
+
+log-facility local7;
+
+{% if hostfile_update %}
+on commit {
+ set ClientName = pick-first-value(host-decl-name, option fqdn.hostname, option host-name);
+ set ClientIp = binary-to-ascii(10, 8, ".", leased-address);
+ set ClientMac = binary-to-ascii(16, 8, ":", substring(hardware, 1, 6));
+ set ClientDomain = pick-first-value(config-option domain-name, "..YYZ!");
+ execute("/usr/libexec/vyos/system/on-dhcp-event.sh", "commit", ClientName, ClientIp, ClientMac, ClientDomain);
+}
+
+on release {
+ set ClientName = pick-first-value(host-decl-name, option fqdn.hostname, option host-name);
+ set ClientIp = binary-to-ascii(10, 8, ".",leased-address);
+ set ClientMac = binary-to-ascii(16, 8, ":",substring(hardware, 1, 6));
+ set ClientDomain = pick-first-value(config-option domain-name, "..YYZ!");
+ execute("/usr/libexec/vyos/system/on-dhcp-event.sh", "release", ClientName, ClientIp, ClientMac, ClientDomain);
+}
+
+on expiry {
+ set ClientName = pick-first-value(host-decl-name, option fqdn.hostname, option host-name);
+ set ClientIp = binary-to-ascii(10, 8, ".",leased-address);
+ set ClientMac = binary-to-ascii(16, 8, ":",substring(hardware, 1, 6));
+ set ClientDomain = pick-first-value(config-option domain-name, "..YYZ!");
+ execute("/usr/libexec/vyos/system/on-dhcp-event.sh", "release", ClientName, ClientIp, ClientMac, ClientDomain);
+}
+{% endif %}
+ddns-update-style {% if ddns_enable -%} interim {%- else -%} none {%- endif %};
+{% if static_route -%}
+option rfc3442-static-route code 121 = array of integer 8;
+option windows-static-route code 249 = array of integer 8;
+{%- endif %}
+{% if static_route -%}
+option wpad-url code 252 = text;
+{% endif %}
+
+{%- if global_parameters %}
+# The following {{ global_parameters | length }} line(s) were added as global-parameters in the CLI and have not been validated
+{%- for param in global_parameters %}
+{{ param }}
+{%- endfor -%}
+{%- endif %}
+
+# Failover configuration
+{% for network in shared_network %}
+{%- if not network.disable -%}
+{%- for subnet in network.subnet %}
+{%- if subnet.failover_name -%}
+failover peer "{{ subnet.failover_name }}" {
+{%- if subnet.failover_status == 'primary' %}
+ primary;
+ mclt 1800;
+ split 128;
+{%- elif subnet.failover_status == 'secondary' %}
+ secondary;
+{%- endif %}
+ address {{ subnet.failover_local_addr }};
+ port 520;
+ peer address {{ subnet.failover_peer_addr }};
+ peer port 520;
+ max-response-delay 30;
+ max-unacked-updates 10;
+ load balance max seconds 3;
+}
+{% endif -%}
+{% endfor -%}
+{% endif -%}
+{% endfor %}
+
+# Shared network configrations
+{% for network in shared_network %}
+{%- if not network.disable -%}
+shared-network {{ network.name }} {
+ {% if network.authoritative %}authoritative;{% endif %}
+ {%- if network.network_parameters %}
+ # The following {{ network.network_parameters | length }} line(s) were added as shared-network-parameters in the CLI and have not been validated
+ {%- for param in network.network_parameters %}
+ {{ param }}
+ {%- endfor -%}
+ {%- endif %}
+ {%- for subnet in network.subnet %}
+ subnet {{ subnet.address }} netmask {{ subnet.netmask }} {
+ {%- if subnet.dns_server %}
+ option domain-name-servers {{ subnet.dns_server | join(', ') }};
+ {%- endif %}
+ {%- if subnet.domain_search %}
+ option domain-search {{ subnet.domain_search | join(', ') }};
+ {%- endif %}
+ {%- if subnet.ntp_server %}
+ option ntp-servers {{ subnet.ntp_server | join(', ') }};
+ {%- endif %}
+ {%- if subnet.pop_server %}
+ option pop-server {{ subnet.pop_server | join(', ') }};
+ {%- endif %}
+ {%- if subnet.smtp_server %}
+ option smtp-server {{ subnet.smtp_server | join(', ') }};
+ {%- endif %}
+ {%- if subnet.time_server %}
+ option time-servers {{ subnet.time_server | join(', ') }};
+ {%- endif %}
+ {%- if subnet.wins_server %}
+ option netbios-name-servers {{ subnet.wins_server | join(', ') }};
+ {%- endif %}
+ {%- if subnet.static_route %}
+ option rfc3442-static-route {{ subnet.static_route }};
+ option windows-static-route {{ subnet.static_route }};
+ {%- endif %}
+ {%- if subnet.ip_forwarding %}
+ option ip-forwarding true;
+ {%- endif -%}
+ {%- if subnet.default_router %}
+ option routers {{ subnet.default_router }};
+ {%- endif -%}
+ {%- if subnet.server_identifier %}
+ option dhcp-server-identifier {{ subnet.server_identifier }};
+ {%- endif -%}
+ {%- if subnet.domain_name %}
+ option domain-name "{{ subnet.domain_name }}";
+ {%- endif -%}
+ {%- if subnet.tftp_server %}
+ option tftp-server-name "{{ subnet.tftp_server }}";
+ {%- endif -%}
+ {%- if subnet.bootfile_name %}
+ option bootfile-name "{{ subnet.bootfile_name }}";
+ filename "{{ subnet.bootfile_name }}";
+ {%- endif -%}
+ {%- if subnet.bootfile_server %}
+ next-server {{ subnet.bootfile_server }};
+ {%- endif -%}
+ {%- if subnet.time_offset %}
+ option time-offset {{ subnet.time_offset }};
+ {%- endif -%}
+ {%- if subnet.wpad_url %}
+ option wpad-url "{{ subnet.wpad_url }}";
+ {%- endif -%}
+ {%- if subnet.client_prefix_length %}
+ option subnet-mask {{ subnet.client_prefix_length }};
+ {%- endif -%}
+ {% if subnet.lease %}
+ default-lease-time {{ subnet.lease }};
+ max-lease-time {{ subnet.lease }};
+ {%- endif -%}
+ {%- for host in subnet.static_mapping %}
+ {% if not host.disable -%}
+ host {{ network.name }}_{{ host.name }} {
+ fixed-address {{ host.ip_address }};
+ hardware ethernet {{ host.mac_address }};
+ {%- if host.static_parameters %}
+ # The following {{ host.static_parameters | length }} line(s) were added as static-mapping-parameters in the CLI and have not been validated
+ {%- for param in host.static_parameters %}
+ {{ param }}
+ {%- endfor -%}
+ {%- endif %}
+ }
+ {%- endif %}
+ {%- endfor %}
+ {%- for range in subnet.range %}
+ range {{ range.start }} {{ range.stop }};
+ {%- endfor %}
+ }
+ {%- endfor %}
+ on commit { set shared-networkname = "{{ network.name }}"; }
+}
+{%- endif %}
+{% endfor %}
+"""
+
+daemon_tmpl = """
+### Autogenerated by dhcp_server.py ###
+
+# sourced by /etc/init.d/isc-dhcp-server
+
+# Path to dhcpd's config file (default: /etc/dhcp/dhcpd.conf).
+DHCPD_CONF=/etc/dhcp/dhcpd.conf
+
+# Path to dhcpd's PID file (default: /var/run/dhcpd.pid).
+DHCPD_PID=/var/run/dhcpd.pid
+
+# Additional options to start dhcpd with.
+# Don't use options -cf or -pf here; use DHCPD_CONF/ DHCPD_PID instead
+OPTIONS="-lf /config/dhcpd.leases"
+
+# On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
+# Separate multiple interfaces with spaces, e.g. "eth0 eth1".
+INTERFACES=""
+"""
+
+default_config_data = {
+ 'disable': False,
+ 'ddns_enable': False,
+ 'global_parameters': [],
+ 'hostfile_update': False,
+ 'static_route': False,
+ 'wpad': False,
+ 'shared_network': [],
+}
+
+def get_config():
+ dhcp = default_config_data
+ conf = Config()
+ if not conf.exists('service dhcp-server'):
+ return None
+ else:
+ conf.set_level('service dhcp-server')
+
+ # check for global disable of DHCP service
+ if conf.exists('disable'):
+ dhcp['disable'] = 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
+
+ # 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': '',
+ 'disable': 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['disable'] = 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(ipaddress.ip_network(net).network_address),
+ 'netmask': str(ipaddress.ip_network(net).netmask),
+ 'bootfile_name': '',
+ 'bootfile_server': '',
+ 'client_prefix_length': '',
+ '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'] = socket.inet_ntoa(struct.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')
+
+ # 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'):
+ # We have no need to store the exclude addresses. Exclude addresses
+ # are recalculated into several ranges
+ exclude = []
+ subnet['exclude'] = conf.return_values('exclude')
+ for addr in subnet['exclude']:
+ exclude.append(ipaddress.ip_address(addr))
+
+ # sort excluded IP addresses ascending
+ exclude = sorted(exclude)
+
+ # calculate multipe ranges based on the excluded IP addresses
+ output = []
+ for range in subnet['range']:
+ range_start = range['start']
+ range_stop = range['stop']
+
+ for i in exclude:
+ # Excluded IP address must be in out specified range
+ if (i >= ipaddress.ip_address(range_start)) and (i <= ipaddress.ip_address(range_stop)):
+ # Build up new IP address range ending one IP address before
+ # our exclude address
+ range = {
+ 'start': str(range_start),
+ 'stop': str(i - 1)
+ }
+ # Our next IP address range will start one address after
+ # our exclude address
+ range_start = i + 1
+ output.append(range)
+
+ # Take care of last IP address range spanning from the last exclude
+ # address (+1) to the end of the initial configured range
+ if i is exclude[-1]:
+ last = {
+ 'start': str(i + 1),
+ 'stop': str(range_stop)
+ }
+ output.append(last)
+ else:
+ # IP address not inside search range, take range is it is
+ output.append(range)
+
+ # We successfully build up a new list containing several IP address
+ # ranges, replace IP address range in our dictionary
+ subnet['range'] = output
+
+ # Static DHCP leases
+ if conf.exists('static-mapping'):
+ 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,
+ 'disable': False,
+ 'ip_address': '',
+ 'mac_address': '',
+ 'static_parameters': []
+ }
+
+ # This static lease is disabled
+ if conf.exists('disable'):
+ mapping['disable'] = True
+
+ # IP address used for this DHCP client
+ if conf.exists('ip-address'):
+ mapping['ip_address'] = conf.return_value('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)
+
+ # 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']:
+ # https://ercpe.de/blog/pushing-static-routes-with-isc-dhcp-server
+ # Option format is:
+ # <netmask>, <network-byte1>, <network-byte2>, <network-byte3>, <router-byte1>, <router-byte2>, <router-byte3>
+ # where bytes with the value 0 are omitted.
+ net = ipaddress.ip_network(subnet['static_subnet'])
+ # add netmask
+ string = str(net.prefixlen) + ','
+ # add network bytes
+ bytes = str(net.network_address).split('.')
+ for b in bytes:
+ if b != '0':
+ string += b + ','
+
+ # add router bytes
+ bytes = subnet['static_router'].split('.')
+ for b in bytes:
+ if b != '0':
+ string += b
+ if b is not bytes[-1]:
+ string += ','
+
+ subnet['static_route'] = string
+
+ # 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'):
+ config['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)
+
+ return dhcp
+
+def verify(dhcp):
+ if dhcp is None:
+ return None
+
+ # If DHCP is enabled we need one share-network
+ if len(dhcp['shared_network']) == 0:
+ raise ConfigError('No DHCP shared networks configured. At least one DHCP shared network must be configured.')
+
+ # 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 DHCP lease subnet must be configured for each shared network.'.format(network['name']))
+
+ # Inspect our subnet configuration
+ failover_names = []
+ listen_ok = False
+ subnets = []
+ for network in dhcp['shared_network']:
+ 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 the missing DHCP static-route parameter: 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 set one or more of the missing DHCP failover parameters: local-address | peer-address | name | status')
+
+ # Failover names must be uniquie
+ if subnet['failover_name'] in failover_names:
+ raise ConfigError('Failover names should be unique: "{0}" has already been configured.'.format(subnet['failover_name']))
+ else:
+ failover_names.append(subnet['failover_name'])
+
+ # Failover requires start/stop ranges for pool
+ if (len(subnet['range']) == 0):
+ raise ConfigError('Atleast one start-stop range must be configured for $subnet to set up DHCP failover.')
+
+ # Check if DHCP address range is inside configured subnet declaration
+ range_start = []
+ range_stop = []
+ for range in subnet['range']:
+ # DHCP stop IP required after start IP
+ if range['start'] and not range['stop']:
+ raise ConfigError('DHCP range stop IP not defined for range start IP "{0}".'.format(range['start']))
+
+ # Start address must be inside network
+ if not ipaddress.ip_address(range['start']) in ipaddress.ip_network(subnet['network']):
+ raise ConfigError('DHCP range start IP "{0}" is not in subnet "{1}" specified in network "{2}."'.format(range['start'], subnet['network'], network['name']))
+
+ # Stop address must be inside network
+ if not ipaddress.ip_address(range['stop']) in ipaddress.ip_network(subnet['network']):
+ raise ConfigError('DHCP range stop IP "{0}" is not in subnet "{1}" specified in network "{2}."'.format(range['stop'], subnet['network'], network['name']))
+
+ # Stop address must be greater or equal to start address
+ if not ipaddress.ip_address(range['stop']) >= ipaddress.ip_address(range['start']):
+ raise ConfigError('DHCP range stop IP "{0}" should be an address greater or equal to the start address "{1}".'.format(range['stop'], range['start']))
+
+ # Range start address must be unique
+ if range['start'] in range_start:
+ raise ConfigError('Conflicting DHCP lease ranges: Pool start address "{0}" defined multipe times'.format(range['start']))
+ else:
+ range_start.append(range['start'])
+
+ # Range stop address must be unique
+ if range['stop'] in range_stop:
+ raise ConfigError('Conflicting DHCP lease ranges: Pool stop address "{0}" defined multipe times'.format(range['stop']))
+ else:
+ range_stop.append(range['stop'])
+
+ # Exclude addresses must be in bound
+ for exclude in subnet['exclude']:
+ if not ipaddress.ip_address(exclude) in ipaddress.ip_network(subnet['network']):
+ raise ConfigError('Exclude IP "{0}" is outside of the DHCP lease network "{1}" under shared network "{2}".'.format(exclude, subnet['network'], network['name']))
+
+ # 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['disable']):
+ active_mapping = True
+ else:
+ active_mapping = True
+
+ if not active_mapping:
+ raise ConfigError('No DHCP address range or active static-mapping set for subnet "{0}".'.format(subnet['network']))
+
+ # Static IP address mappings require both an IP address and MAC address
+ for mapping in subnet['static_mapping']:
+ # Static IP address must be configured
+ if not mapping['ip_address']:
+ raise ConfigError('No static lease IP address specified for static mapping "{0}" under shared network name "{1}".'.format(mapping['name'], network['name']))
+
+ # Static IP address must be in bound
+ if not ipaddress.ip_address(mapping['ip_address']) in ipaddress.ip_network(subnet['network']):
+ raise ConfigError('Static DHCP lease IP "{0}" under static mapping "{1}" in shared network "{2}" is outside DHCP lease network "{3}".'.format(mapping['ip_address'], mapping['name'], network['name'], subnet['network'], ))
+
+ # Static mapping requires MAC address
+ if not mapping['mac_address']:
+ raise ConfigError('No static lease MAC address specified for static mapping "{0}" under shared network name "{1}".'.format(mapping['name'], network['name']))
+
+ #
+ # There must be one subnet connected to a real interface
+ #
+ for interface in netifaces.interfaces():
+ # Retrieve IP address of network interface
+ ip = netifaces.ifaddresses(interface)[netifaces.AF_INET][0]['addr']
+ if ipaddress.ip_address(ip) in ipaddress.ip_network(subnet['network']):
+ listen_ok = True
+
+ #
+ # Subnets must be non overlapping
+ #
+ if subnet['network'] in subnets:
+ raise ConfigError('Subnets must be unique! "{0}" defined multiple times.'.format(subnet))
+ else:
+ subnets.append(subnet['network'])
+
+ #
+ # Check for overlapping subnets
+ #
+ net = ipaddress.ip_network(subnet['network'])
+ for n in subnets:
+ net2 = ipaddress.ip_network(n)
+ if (net.compare_networks(net2) != 0):
+ if net.overlaps(net2):
+ raise ConfigError('Conflicting subnet ranges: "{0}" overlaps "{1}"'.format(net, net2))
+
+ if not listen_ok:
+ raise ConfigError('None of the DHCP lease subnets are inside any configured subnet on broadcast interfaces. At least one lease subnet must be set such that DHCP server listens on a one broadcast interface')
+
+ return None
+
+def generate(dhcp):
+ if dhcp is None:
+ return None
+
+ tmpl = jinja2.Template(config_tmpl)
+ config_text = tmpl.render(dhcp)
+ with open(config_file, 'w') as f:
+ f.write(config_text)
+
+ tmpl = jinja2.Template(daemon_tmpl)
+ config_text = tmpl.render(dhcp)
+ with open(daemon_config_file, 'w') as f:
+ f.write(config_text)
+
+ return None
+
+def apply(dhcp):
+ if dhcp is not None:
+ os.system('sudo systemctl restart isc-dhcp-server.service')
+ else:
+ # DHCP server is removed in the commit
+ os.system('sudo systemctl stop isc-dhcp-server.service')
+ os.unlink(config_file)
+ os.unlink(daemon_config_file)
+
+ return None
+
+if __name__ == '__main__':
+ try:
+ c = get_config()
+ verify(c)
+ generate(c)
+ apply(c)
+ except ConfigError as e:
+ print(e)
+ sys.exit(1)