Add DHCP server component based on python_dhcp_server

LICENSE

@@ -677,3 +677,9 @@ Public License instead of this License.  But first, please read
 
 Logo contains elements Copyright Anjara Begue via <http://www.vecteezy.com>
 which are released under a Creative Commons Attribution license.
+
+----
+
+PVC contains code based on the python_dhcp_server Copyright Nicco Kunzmann
+via <https://github.com/niccokunzmann/python_dhcp_server> which is released
+under an MIT license.

router-daemon/pvcrd/DHCPServer.py

@@ -0,0 +1,817 @@
+#!/usr/bin/python3
+
+# DHCPServer.py - PVC router DHCP server with Zookeeper database
+# Part of the Parallel Virtual Cluster (PVC) system
+#
+#    Copyright (C) 2018  Joshua M. Boniface <joshua@boniface.me>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    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 <https://www.gnu.org/licenses/>.
+#
+###############################################################################
+# 
+# Modified from python_dhcp_server
+# Source: https://github.com/niccokunzmann/python_dhcp_server
+#
+#    Copyright (c) 2015 Nicco Kunzmann and released under the MIT license
+#
+###############################################################################
+
+import time
+import threading
+import struct
+import queue
+import collections
+import traceback
+import random
+import base64
+import select
+import ipaddress
+from socket import *
+
+# see https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
+# section DHCP options
+
+def inet_ntoaX(data):
+    return ['.'.join(map(str, data[i:i + 4])) for i in range(0, len(data), 4)]
+
+def inet_atonX(ips):
+    return b''.join(map(inet_aton, ips))
+
+dhcp_message_types = {
+    1 : 'DHCPDISCOVER',
+    2 : 'DHCPOFFER',
+    3 : 'DHCPREQUEST',
+    4 : 'DHCPDECLINE',
+    5 : 'DHCPACK',
+    6 : 'DHCPNAK',
+    7 : 'DHCPRELEASE',
+    8 : 'DHCPINFORM',
+}
+reversed_dhcp_message_types = dict()
+for i, v in dhcp_message_types.items():
+    reversed_dhcp_message_types[v] = i
+
+shortunpack = lambda data: (data[0] << 8) + data[1]
+shortpack = lambda i: bytes([i >> 8, i & 255])
+
+
+def macunpack(data):
+    s = base64.b16encode(data)
+    return ':'.join([s[i:i+2].decode('ascii') for i in range(0, 12, 2)])
+
+def macpack(mac):
+    return base64.b16decode(mac.replace(':', '').replace('-', '').encode('ascii'))
+
+def unpackbool(data):
+    return data[0]
+
+def packbool(bool):
+    return bytes([bool])
+
+options = [
+# RFC1497 vendor extensions
+    ('pad', None, None),
+    ('subnet_mask', inet_ntoa, inet_aton),
+    ('time_offset', None, None),
+    ('router', inet_ntoaX, inet_atonX),
+    ('time_server', inet_ntoaX, inet_atonX),
+    ('name_server', inet_ntoaX, inet_atonX),
+    ('domain_name_server', inet_ntoaX, inet_atonX),
+    ('log_server', inet_ntoaX, inet_atonX),
+    ('cookie_server', inet_ntoaX, inet_atonX),
+    ('lpr_server', inet_ntoaX, inet_atonX),
+    ('impress_server', inet_ntoaX, inet_atonX),
+    ('resource_location_server', inet_ntoaX, inet_atonX),
+    ('host_name', lambda d: d.decode('ASCII'), lambda d: d.encode('ASCII')),
+    ('boot_file_size', None, None),
+    ('merit_dump_file', None, None),
+    ('domain_name', None, None),
+    ('swap_server', inet_ntoa, inet_aton),
+    ('root_path', None, None),
+    ('extensions_path', None, None),
+# IP Layer Parameters per Host
+    ('ip_forwarding_enabled', unpackbool, packbool),
+    ('non_local_source_routing_enabled', unpackbool, packbool),
+    ('policy_filer', None, None),
+    ('maximum_datagram_reassembly_size', shortunpack, shortpack),
+    ('default_ip_time_to_live', lambda data: data[0], lambda i: bytes([i])),
+    ('path_mtu_aging_timeout', None, None),
+    ('path_mtu_plateau_table', None, None),
+# IP Layer Parameters per Interface
+    ('interface_mtu', None, None),
+    ('all_subnets_are_local', unpackbool, packbool),
+    ('broadcast_address', inet_ntoa, inet_aton),
+    ('perform_mask_discovery', unpackbool, packbool),
+    ('mask_supplier', None, None),
+    ('perform_router_discovery', None, None),
+    ('router_solicitation_address', inet_ntoa, inet_aton),
+    ('static_route', None, None),
+# Link Layer Parameters per Interface
+    ('trailer_encapsulation_option', None, None),
+    ('arp_cache_timeout', None, None),
+    ('ethernet_encapsulation', None, None),
+# TCP Parameters
+    ('tcp_default_ttl', None, None),
+    ('tcp_keep_alive_interval', None, None),
+    ('tcp_keep_alive_garbage', None, None),
+# Application and Service Parameters Part 1
+    ('network_information_service_domain', None, None),
+    ('network_informtaion_servers', inet_ntoaX, inet_atonX),
+    ('network_time_protocol_servers', inet_ntoaX, inet_atonX),
+    ('vendor_specific_information', None, None),
+    ('netbios_over_tcp_ip_name_server', inet_ntoaX, inet_atonX),
+    ('netbios_over_tcp_ip_datagram_distribution_server', inet_ntoaX, inet_atonX),
+    ('netbios_over_tcp_ip_node_type', None, None),
+    ('netbios_over_tcp_ip_scope', None, None),
+    ('x_window_system_font_server', inet_ntoaX, inet_atonX),
+    ('x_window_system_display_manager', inet_ntoaX, inet_atonX),
+# DHCP Extensions
+    ('requested_ip_address', inet_ntoa, inet_aton),
+    ('ip_address_lease_time', lambda d: struct.unpack('>I', d)[0], lambda i: struct.pack('>I', i)),
+    ('option_overload', None, None),
+    ('dhcp_message_type', lambda data: dhcp_message_types.get(data[0], data[0]), (lambda name: bytes([reversed_dhcp_message_types.get(name, name)]))),
+    ('server_identifier', inet_ntoa, inet_aton),
+    ('parameter_request_list', list, bytes),
+    ('message', None, None),
+    ('maximum_dhcp_message_size', shortunpack, shortpack),
+    ('renewal_time_value', None, None),
+    ('rebinding_time_value', None, None),
+    ('vendor_class_identifier', None, None),
+    ('client_identifier', macunpack, macpack),
+    ('tftp_server_name', None, None),
+    ('boot_file_name', None, None),
+# Application and Service Parameters Part 2
+    ('network_information_service_domain', None, None),
+    ('network_information_servers', inet_ntoaX, inet_atonX),
+    ('', None, None),
+    ('', None, None),
+    ('mobile_ip_home_agent', inet_ntoaX, inet_atonX),
+    ('smtp_server', inet_ntoaX, inet_atonX),
+    ('pop_servers', inet_ntoaX, inet_atonX),
+    ('nntp_server', inet_ntoaX, inet_atonX),
+    ('default_www_server', inet_ntoaX, inet_atonX),
+    ('default_finger_server', inet_ntoaX, inet_atonX),
+    ('default_irc_server', inet_ntoaX, inet_atonX),
+    ('streettalk_server', inet_ntoaX, inet_atonX),
+    ('stda_server', inet_ntoaX, inet_atonX),
+    ]
+
+assert options[18][0] == 'extensions_path', options[18][0]
+assert options[25][0] == 'path_mtu_plateau_table', options[25][0]
+assert options[33][0] == 'static_route', options[33][0]
+assert options[50][0] == 'requested_ip_address', options[50][0]
+assert options[64][0] == 'network_information_service_domain', options[64][0]
+assert options[76][0] == 'stda_server', options[76][0]
+
+
+class ReadBootProtocolPacket(object):
+
+    for i, o in enumerate(options):
+        locals()[o[0]] = None
+        locals()['option_{0}'.format(i)] = None
+
+    del i, o
+
+    def __init__(self, data, address = ('0.0.0.0', 0)):
+        self.data = data
+        self.address = address
+        self.host = address[0]
+        self.port = address[1]
+
+        # wireshark = wikipedia = data[...]
+        
+        self.message_type = self.OP =                data[0]
+        self.hardware_type = self.HTYPE =            data[1]
+        self.hardware_address_length = self.HLEN =   data[2]
+        self.hops = self.HOPS =                      data[3]
+
+        self.XID = self.transaction_id = struct.unpack('>I', data[4:8])[0]
+
+        self.seconds_elapsed = self.SECS = shortunpack(data[8:10])
+        self.bootp_flags = self.FLAGS =    shortunpack(data[8:10])
+
+        self.client_ip_address = self.CIADDR = inet_ntoa(data[12:16])
+        self.your_ip_address   = self.YIADDR = inet_ntoa(data[16:20])
+        self.next_server_ip_address = self.SIADDR = inet_ntoa(data[20:24])
+        self.relay_agent_ip_address = self.GIADDR = inet_ntoa(data[24:28])
+
+        self.client_mac_address = self.CHADDR = macunpack(data[28: 28 + self.hardware_address_length])
+        index = 236
+        self.magic_cookie = self.magic_cookie = inet_ntoa(data[index:index + 4]); index += 4
+        self.options = dict()
+        self.named_options = dict()
+        while index < len(data):
+            option = data[index]; index += 1
+            if option == 0:
+                # padding
+                # Can be used to pad other options so that they are aligned to the word boundary; is not followed by length byte
+                continue
+            if option == 255:
+                # end
+                break
+            option_length = data[index]; index += 1
+            option_data = data[index: index + option_length]; index += option_length
+            self.options[option] = option_data
+            if option < len(options):
+                option_name, function, _ = options[option]
+                if function:
+                    option_data = function(option_data)
+                if option_name:
+                    setattr(self, option_name, option_data)
+                    self.named_options[option_name] = option_data
+            setattr(self, 'option_{}'.format(option), option_data)
+
+    def __getitem__(self, key):
+        print(key, dir(self))
+        return getattr(self, key, None)
+
+    def __contains__(self, key):
+        return key in self.__dict__
+
+    @property
+    def formatted_named_options(self):
+        return "\n".join("{}:\t{}".format(name.replace('_', ' '), value) for name, value in sorted(self.named_options.items()))
+
+    def __str__(self):
+        return """Message Type: {self.message_type}
+client MAC address: {self.client_mac_address}
+client IP address: {self.client_ip_address}
+your IP address: {self.your_ip_address}
+next server IP address: {self.next_server_ip_address}
+{self.formatted_named_options}
+""".format(self = self)
+
+    def __gt__(self, other):
+        return id(self) < id(other)
+
+data = base64.b16decode(b'02010600f7b41ad100000000c0a800640000000000000000000000007c7a914bca6c00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000638253633501053604c0a800010104ffffff000304c0a800010604c0a80001ff00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000'.upper())
+assert data[0] == 2
+p = ReadBootProtocolPacket(data)
+assert p.message_type == 2
+assert p.hardware_type == 1
+assert p.hardware_address_length == 6
+assert p.hops == 0
+assert p.transaction_id == 4155775697
+assert p.seconds_elapsed == 0
+assert p.bootp_flags == 0
+assert p.client_ip_address == '192.168.0.100'
+assert p.your_ip_address == '0.0.0.0'
+assert p.next_server_ip_address == '0.0.0.0'
+assert p.relay_agent_ip_address == '0.0.0.0'
+assert p.client_mac_address.lower() == '7c:7a:91:4b:ca:6c'
+assert p.magic_cookie == '99.130.83.99'
+assert p.dhcp_message_type == 'DHCPACK'
+assert p.options[53] == b'\x05'
+assert p.server_identifier == '192.168.0.1'
+assert p.subnet_mask == '255.255.255.0'
+assert p.router == ['192.168.0.1']
+assert p.domain_name_server == ['192.168.0.1']
+str(p)
+
+if __name__ == '__main__':
+    s1 = socket(type = SOCK_DGRAM)
+    s1.setsockopt(SOL_IP, SO_REUSEADDR, 1)
+    s1.bind(('', 67))
+    #s2 = socket(type = SOCK_DGRAM)
+    #s2.setsockopt(SOL_IP, SO_REUSEADDR, 1)
+    #s2.bind(('', 68))
+    while 1:
+        reads = select.select([s1], [], [], 1)[0]
+        for s in reads:
+            packet = ReadBootProtocolPacket(*s.recvfrom(4096))
+            print(packet)
+
+
+def get_host_ip_addresses():
+    return gethostbyname_ex(gethostname())[2]
+
+
+class WriteBootProtocolPacket(object):
+
+    message_type = 2 # 1 for client -> server 2 for server -> client
+    hardware_type = 1
+    hardware_address_length = 6
+    hops = 0
+
+    transaction_id = None
+
+    seconds_elapsed = 0
+    bootp_flags = 0 # unicast
+
+    client_ip_address = '0.0.0.0'
+    your_ip_address = '0.0.0.0'
+    next_server_ip_address = '0.0.0.0'
+    relay_agent_ip_address = '0.0.0.0'
+
+    client_mac_address = None
+    magic_cookie = '99.130.83.99'
+
+    parameter_order = []
+    
+    def __init__(self, configuration):
+        for i in range(256):
+            names = ['option_{}'.format(i)]
+            if i < len(options) and hasattr(configuration, options[i][0]):
+                names.append(options[i][0])
+            for name in names:
+                if hasattr(configuration, name):
+                    setattr(self, name, getattr(configuration, name))
+
+    def to_bytes(self):
+        result = bytearray(236)
+        
+        result[0] = self.message_type
+        result[1] = self.hardware_type
+        result[2] = self.hardware_address_length
+        result[3] = self.hops
+
+        result[4:8] = struct.pack('>I', self.transaction_id)
+
+        result[ 8:10] = shortpack(self.seconds_elapsed)
+        result[10:12] = shortpack(self.bootp_flags)
+
+        result[12:16] = inet_aton(self.client_ip_address)
+        result[16:20] = inet_aton(self.your_ip_address)
+        result[20:24] = inet_aton(self.next_server_ip_address)
+        result[24:28] = inet_aton(self.relay_agent_ip_address)
+
+        result[28:28 + self.hardware_address_length] = macpack(self.client_mac_address)
+        
+        result += inet_aton(self.magic_cookie)
+
+        for option in self.options:
+            value = self.get_option(option)
+            #print(option, value)
+            if value is None:
+                continue
+            result += bytes([option, len(value)]) + value
+        result += bytes([255])
+        return bytes(result)
+
+    def get_option(self, option):
+        if option < len(options) and hasattr(self, options[option][0]):
+            value = getattr(self, options[option][0])
+        elif hasattr(self, 'option_{}'.format(option)):
+            value = getattr(self, 'option_{}'.format(option))
+        else:
+            return None
+        function = options[option][2]
+        if function and value is not None:
+            value = function(value)
+        return value
+    
+    @property
+    def options(self):
+        done = list()
+        # fulfill wishes
+        for option in self.parameter_order:
+            if option < len(options) and hasattr(self, options[option][0]) or hasattr(self, 'option_{}'.format(option)):
+                # this may break with the specification because we must try to fulfill the wishes
+                if option not in done:
+                    done.append(option)
+        # add my stuff
+        for option, o in enumerate(options):
+            if o[0] and hasattr(self, o[0]):
+                if option not in done:
+                    done.append(option)
+        for option in range(256):
+            if hasattr(self, 'option_{}'.format(option)):
+                if option not in done:
+                    done.append(option)
+        return done
+
+    def __str__(self):
+        return str(ReadBootProtocolPacket(self.to_bytes()))
+
+class DelayWorker(object):
+
+    def __init__(self):
+        self.closed = False
+        self.queue = queue.PriorityQueue()
+        self.thread = threading.Thread(target = self._delay_response_thread)
+        self.thread.daemon = True
+        self.thread.start()
+
+    def _delay_response_thread(self):
+        while not self.closed:
+            p = self.queue.get()
+            if self.closed:
+                break
+            t, func, args, kw = p
+            now = time.time()
+            if now < t:
+                time.sleep(0.01)
+                self.queue.put(p)
+            else:
+                func(*args, **kw)
+
+    def do_after(self, seconds, func, args = (), kw = {}):
+        self.queue.put((time.time() + seconds, func, args, kw))
+
+    def close(self):
+        self.closed = True
+
+class Transaction(object):
+
+    def __init__(self, server):
+        self.server = server
+        self.configuration = server.configuration
+        self.packets = []
+        self.done_time = time.time() + self.configuration.length_of_transaction
+        self.done = False
+        self.do_after = self.server.delay_worker.do_after
+
+    def is_done(self):
+        return self.done or self.done_time < time.time()
+
+    def close(self):
+        self.done = True
+
+    def receive(self, packet):
+        # packet from client <-> packet.message_type == 1
+        if packet.message_type == 1 and packet.dhcp_message_type == 'DHCPDISCOVER':
+            self.do_after(self.configuration.dhcp_offer_after_seconds,
+                          self.received_dhcp_discover, (packet,), )
+        elif packet.message_type == 1 and packet.dhcp_message_type == 'DHCPREQUEST':
+            self.do_after(self.configuration.dhcp_acknowledge_after_seconds,
+                          self.received_dhcp_request, (packet,), )
+        elif packet.message_type == 1 and packet.dhcp_message_type == 'DHCPINFORM':
+            self.received_dhcp_inform(packet)
+        else:
+            return False
+        return True
+
+    def received_dhcp_discover(self, discovery):
+        if self.is_done(): return
+        self.configuration.debug('discover:\n {}'.format(str(discovery).replace('\n', '\n\t')))
+        self.send_offer(discovery)
+
+    def send_offer(self, discovery):
+        # https://tools.ietf.org/html/rfc2131
+        offer = WriteBootProtocolPacket(self.configuration)
+        offer.parameter_order = discovery.parameter_request_list
+        mac = discovery.client_mac_address
+        ip = offer.your_ip_address = self.server.get_ip_address(discovery)
+        # offer.client_ip_address = 
+        offer.transaction_id = discovery.transaction_id
+        # offer.next_server_ip_address =
+        offer.relay_agent_ip_address = discovery.relay_agent_ip_address
+        offer.client_mac_address = mac
+        offer.client_ip_address = discovery.client_ip_address or '0.0.0.0'
+        offer.bootp_flags = discovery.bootp_flags
+        offer.dhcp_message_type = 'DHCPOFFER'
+        offer.client_identifier = mac
+        self.server.broadcast(offer)
+    
+    def received_dhcp_request(self, request):
+        if self.is_done(): return 
+        self.server.client_has_chosen(request)
+        self.acknowledge(request)
+        self.close()
+
+    def acknowledge(self, request):
+        ack = WriteBootProtocolPacket(self.configuration)
+        ack.parameter_order = request.parameter_request_list
+        ack.transaction_id = request.transaction_id
+        # ack.next_server_ip_address =
+        ack.bootp_flags = request.bootp_flags
+        ack.relay_agent_ip_address = request.relay_agent_ip_address
+        mac = request.client_mac_address
+        ack.client_mac_address = mac
+        requested_ip_address = request.requested_ip_address
+        ack.client_ip_address = request.client_ip_address or '0.0.0.0'
+        ack.your_ip_address = self.server.get_ip_address(request)
+        ack.dhcp_message_type = 'DHCPACK'
+        self.server.broadcast(ack)
+
+    def received_dhcp_inform(self, inform):
+        self.close()
+        self.server.client_has_chosen(inform)
+
+class DHCPServerConfiguration(object):
+    def __init__(self, configuration):
+        self.dhcp_offer_after_seconds = 1
+        self.dhcp_acknowledge_after_seconds = 1
+        self.length_of_transaction = 60
+
+        print(configuration)
+        if not configuration:
+            print('ERROR: Invalid DHCP configuration!')
+            exit(1)
+
+        self.ipaddr = configuration['ipaddr']
+        self.iface = configuration['iface']
+
+        network_cidr = ipaddress.IPv4Network(configuration['network'], False)
+        self.network = network_cidr.network_address
+        self.broadcast_address = network_cidr.broadcast_address
+        self.subnet_mask = network_cidr.netmask
+
+        self.router = configuration['router']
+        self.domain_name_server = configuration['dns_servers']
+
+        # 1 day is 86400
+        self.ip_address_lease_time = 300 # seconds
+
+        self.host_file = 'hosts.csv'
+
+        self.debug = lambda *args, **kw: None
+
+    def all_ip_addresses(self):
+        ips = ip_addresses(self.network, self.subnet_mask)
+        for i in range(5):
+            next(ips)
+        return ips
+
+    def network_filter(self):
+        return NETWORK(self.network, self.subnet_mask)
+
+def ip_addresses(network, subnet_mask):
+    subnet_mask = struct.unpack('>I', inet_aton(subnet_mask))[0]
+    network = struct.unpack('>I', inet_aton(network))[0]
+    network = network & subnet_mask
+    start = network + 1
+    end = (network | (~subnet_mask & 0xffffffff))
+    return (inet_ntoa(struct.pack('>I', i)) for i in range(start, end))
+
+class ALL(object):
+    def __eq__(self, other):
+        return True
+    def __repr__(self):
+        return self.__class__.__name__
+ALL = ALL()
+
+class GREATER(object):
+    def __init__(self, value):
+        self.value = value
+    def __eq__(self, other):
+        return type(self.value)(other) > self.value
+
+class NETWORK(object):
+    def __init__(self, network, subnet_mask):
+        self.subnet_mask = struct.unpack('>I', inet_aton(subnet_mask))[0]
+        print(self.subnet_mask)
+        self.network = struct.unpack('>I', inet_aton(network))[0]
+    def __eq__(self, other):
+        ip = struct.unpack('>I', inet_aton(other))[0]
+        return ip & self.subnet_mask == self.network and \
+               ip - self.network and \
+               ip - self.network != ~self.subnet_mask & 0xffffffff
+        
+class CASEINSENSITIVE(object):
+    def __init__(self, s):
+        self.s = s.lower()
+    def __eq__(self, other):
+        return self.s == other.lower()
+
+class CSVDatabase(object):
+
+    delimiter = ';'
+
+    def __init__(self, file_name):
+        self.file_name = file_name
+        self.file('a').close() # create file
+
+    def file(self, mode = 'r'):
+        return open(self.file_name, mode)
+
+    def get(self, pattern):
+        pattern = list(pattern)
+        return [line for line in self.all() if pattern == line]
+
+    def add(self, line):
+        with self.file('a') as f:
+            f.write(self.delimiter.join(line) + '\n')
+
+    def delete(self, pattern):
+        lines = self.all()
+        lines_to_delete = self.get(pattern)
+        self.file('w').close() # empty file
+        for line in lines:
+            if line not in lines_to_delete:
+                self.add(line)
+
+    def all(self):
+        with self.file() as f:
+            return [list(line.strip().split(self.delimiter)) for line in f]
+
+class Host(object):
+
+    def __init__(self, mac, ip, hostname, last_used):
+        self.mac = mac.upper()
+        self.ip = ip
+        self.hostname = hostname
+        self.last_used = int(last_used)
+
+    @classmethod
+    def from_tuple(cls, line):
+        mac, ip, hostname, last_used = line
+        last_used = int(last_used)
+        return cls(mac, ip, hostname, last_used)
+
+    @classmethod
+    def from_packet(cls, packet):
+        return cls(packet.client_mac_address,
+                   packet.requested_ip_address or packet.client_ip_address,
+                   packet.host_name or '',
+                   int(time.time()))
+
+    @staticmethod
+    def get_pattern(mac = ALL, ip = ALL, hostname = ALL, last_used = ALL):
+        return [mac, ip, hostname, last_used]
+
+    def to_tuple(self):
+        return [self.mac, self.ip, self.hostname, str(int(self.last_used))]
+
+    def to_pattern(self):
+        return self.get_pattern(ip = self.ip, mac = self.mac)
+
+    def __hash__(self):
+        return hash(self.key)
+
+    def __eq__(self, other):
+        return self.to_tuple() == other.to_tuple()
+
+    def has_valid_ip(self):
+        return self.ip and self.ip != '0.0.0.0'
+        
+
+class HostDatabase(object):
+    def __init__(self, file_name):
+        self.db = CSVDatabase(file_name)
+
+    def get(self, **kw):
+        pattern = Host.get_pattern(**kw)
+        return list(map(Host.from_tuple, self.db.get(pattern)))
+
+    def add(self, host):
+        self.db.add(host.to_tuple())
+
+    def delete(self, host = None, **kw):
+        if host is None:
+            pattern = Host.get_pattern(**kw)
+        else:
+            pattern = host.to_pattern()
+        self.db.delete(pattern)
+
+    def all(self):
+        return list(map(Host.from_tuple, self.db.all()))
+
+    def replace(self, host):
+        self.delete(host)
+        self.add(host)
+        
+def sorted_hosts(hosts):
+    hosts = list(hosts)
+    hosts.sort(key = lambda host: (host.hostname.lower(), host.mac.lower(), host.ip.lower()))
+    return hosts
+
+class DHCPServer(object):
+
+    def __init__(self, configuration):
+        self.configuration = configuration
+        self.socket = socket(type=SOCK_DGRAM)
+        self.socket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
+        self.socket.setsockopt(SOL_SOCKET, 25, self.configuration.iface.encode('ascii'))
+        self.socket.bind(('<broadcast>', 67))
+        print(self.socket)
+        self.delay_worker = DelayWorker()
+        self.closed = False
+        self.transactions = collections.defaultdict(lambda: Transaction(self)) # id: transaction
+        self.hosts = HostDatabase(self.configuration.host_file)
+        self.time_started = time.time()
+
+    def close(self):
+        self.socket.close()
+        self.closed = True
+        self.delay_worker.close()
+        for transaction in list(self.transactions.values()):
+            transaction.close()
+
+    def update(self, timeout = 0):
+        try:
+            reads = select.select([self.socket], [], [], timeout)[0]
+        except ValueError:
+            # ValueError: file descriptor cannot be a negative integer (-1)
+            return
+        for socket in reads:
+            try:
+                packet = ReadBootProtocolPacket(*socket.recvfrom(4096))
+            except OSError:
+                # OSError: [WinError 10038] An operation was attempted on something that is not a socket
+                pass
+            else:
+                self.received(packet)
+        for transaction_id, transaction in list(self.transactions.items()):
+            if transaction.is_done():
+                transaction.close()
+                self.transactions.pop(transaction_id)
+
+    def received(self, packet):
+        if not self.transactions[packet.transaction_id].receive(packet):
+            self.configuration.debug('received:\n {}'.format(str(packet).replace('\n', '\n\t')))
+            
+    def client_has_chosen(self, packet):
+        self.configuration.debug('client_has_chosen:\n {}'.format(str(packet).replace('\n', '\n\t')))
+        host = Host.from_packet(packet)
+        if not host.has_valid_ip():
+            return
+        self.hosts.replace(host)
+
+    def is_valid_client_address(self, address):
+        if address is None:
+            return False
+        a = address.split('.')
+        s = self.configuration.subnet_mask.split('.')
+        n = self.configuration.network.split('.')
+        return all(s[i] == '0' or a[i] == n[i] for i in range(4))
+
+    def get_ip_address(self, packet):
+        mac_address = packet.client_mac_address
+        requested_ip_address = packet.requested_ip_address
+        known_hosts = self.hosts.get(mac = CASEINSENSITIVE(mac_address))
+        ip = None
+        if known_hosts:
+            # 1. choose known ip address
+            for host in known_hosts:
+                if self.is_valid_client_address(host.ip):
+                    ip = host.ip
+            print('known ip:', ip)
+        if ip is None and self.is_valid_client_address(requested_ip_address):
+            # 2. choose valid requested ip address
+            ip = requested_ip_address
+            print('valid ip:', ip)
+        if ip is None:
+            # 3. choose new, free ip address
+            chosen = False
+            network_hosts = self.hosts.get(ip = self.configuration.network_filter())
+            for ip in self.configuration.all_ip_addresses():
+                if not any(host.ip == ip for host in network_hosts):
+                    chosen = True
+                    break
+            if not chosen:
+                # 4. reuse old valid ip address
+                network_hosts.sort(key = lambda host: host.last_used)
+                ip = network_hosts[0].ip
+                assert self.is_valid_client_address(ip)
+            print('new ip:', ip)
+        if not any([host.ip == ip for host in known_hosts]):
+            print('add', mac_address, ip, packet.host_name)
+            self.hosts.replace(Host(mac_address, ip, packet.host_name or '', time.time()))
+        return ip
+
+    @property
+    def server_identifiers(self):
+        return get_host_ip_addresses()
+
+    def broadcast(self, packet):
+        self.configuration.debug('broadcasting:\n {}'.format(str(packet).replace('\n', '\n\t')))
+        for addr in self.server_identifiers:
+            broadcast_socket = socket(type = SOCK_DGRAM)
+            broadcast_socket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
+            broadcast_socket.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)
+            packet.server_identifier = addr
+            broadcast_socket.bind((self.configuration.ipaddr, 67))
+            try:
+                data = packet.to_bytes()
+                broadcast_socket.sendto(data, ('255.255.255.255', 68))
+                broadcast_socket.sendto(data, (addr, 68))
+            finally:
+                broadcast_socket.close()
+
+    def run(self):
+        while not self.closed:
+            try:
+                self.update(1)
+            except KeyboardInterrupt:
+                break
+            except:
+                traceback.print_exc()
+
+    def start(self):
+        self.thread = threading.Thread(target = self.run)
+        self.thread.daemon = True
+        self.thread.start()
+
+    def debug_clients(self):
+        for line in self.ips.all():
+            line = '\t'.join(line)
+            if line:
+                self.configuration.debug(line)
+
+    def get_all_hosts(self):
+        return sorted_hosts(self.hosts.get())
+
+    def get_current_hosts(self):
+        return sorted_hosts(self.hosts.get(last_used = GREATER(self.time_started)))

router-daemon/pvcrd/RouterInstance.py

@@ -104,7 +104,8 @@ class RouterInstance():
                     zkhandler.writedata(self.zk_conn, { '/routers/{}/networkstate'.format(self.t_router[router].getname()): 'primary' })
         time.sleep(2)
         for network in self.s_network:
-            self.s_network[network].removeAddress()
+            self.s_network[network].removeGatewayAddress()
+            self.s_network[network].stopDHCPServer()
 
     def set_secondary(self):
         result = zkhandler.writedata(self.zk_conn, {
@@ -117,7 +118,8 @@ class RouterInstance():
         ansiiprint.echo('Setting router {} to primary state.'.format(self.name), '', 'i')
         ansiiprint.echo('Network list: {}'.format(', '.join(self.network_list)), '', 'c')
         for network in self.s_network:
-            self.s_network[network].createAddress()
+            self.s_network[network].createGatewayAddress()
+            self.s_network[network].startDHCPServer()
         for router in self.t_router:
             if self.t_router[router].getname() != self.this_router:
                 if self.t_router[router].getnetworkstate() != 'secondary':

router-daemon/pvcrd/VXNetworkInstance.py

@@ -27,6 +27,8 @@ import daemon_lib.ansiiprint as ansiiprint
 import daemon_lib.zkhandler as zkhandler
 import daemon_lib.common as common
 
+import pvcrd.DHCPServer as DHCPServer
+
 class VXNetworkInstance():
     # Initialization function
     def __init__ (self, vni, zk_conn, config, this_router):
@@ -37,6 +39,7 @@ class VXNetworkInstance():
 
         self.old_description = zkhandler.readdata(self.zk_conn, '/networks/{}'.format(self.vni))
         self.description = zkhandler.readdata(self.zk_conn, '/networks/{}'.format(self.vni))
+        self.domain = zkhandler.readdata(self.zk_conn, '/networks/{}/domain'.format(self.vni))
         self.ip_gateway = zkhandler.readdata(self.zk_conn, '/networks/{}/ip_gateway'.format(self.vni))
         self.ip_network = zkhandler.readdata(self.zk_conn, '/networks/{}/ip_network'.format(self.vni))
         self.ip_cidrnetmask = self.ip_network.split('/')[-1]
@@ -45,6 +48,9 @@ class VXNetworkInstance():
         self.vxlan_nic = 'vxlan{}'.format(self.vni)
         self.bridge_nic = 'br{}'.format(self.vni)
 
+        self.dhcp_reservations = {}
+        self.firewall_rules = {}
+
         self.createNetwork()
 
         # Zookeper handlers for changed states
@@ -72,32 +78,159 @@ class VXNetworkInstance():
         def watch_network_dhcp_status(data, stat, event=''):
             if data != None and self.dhcp_flag != data.decode('ascii'):
                 self.dhcp_flag = ( data.decode('ascii') == 'True' )
+                if self.dhcp_flag:
+                    self.dhcp_instance = DHCPInstance.DHCPInstance(self.vni, self.config)
+                else:
+                    self.dhcp_instance.remove()
+                    self.dhcp_instance = None
+
+
+        @zk_conn.ChildrenWatch('/networks/{}/dhcp_reservations'.format(self.vni))
+        def watch_network_dhcp_reservations(data, event=''):
+            print(data)
 
     def getvni(self):
         return self.vni
 
     def createNetwork(self):
-        ansiiprint.echo('Creating VNI {} device on interface {}'.format(self.vni, self.vni_dev), '', 'o')
+        ansiiprint.echo(
-        common.run_os_command('ip link add {} type vxlan id {} dstport 4789 dev {}'.format(self.vxlan_nic, self.vni, self.vni_dev))
+            'Creating VNI {} device on interface {}'.format(
-        common.run_os_command('brctl addbr {}'.format(self.bridge_nic))
+                self.vni,
-        common.run_os_command('brctl addif {} {}'.format(self.bridge_nic, self.vxlan_nic))
+                self.vni_dev
-        common.run_os_command('ip link set {} up'.format(self.vxlan_nic))
+            ),
-        common.run_os_command('ip link set {} up'.format(self.bridge_nic))
+            '',
+            'o'
+        )
+        common.run_os_command(
+            'ip link add {} type vxlan id {} dstport 4789 dev {}'.format(
+                self.vxlan_nic,
+                self.vni,
+                self.vni_dev
+            )
+        )
+        common.run_os_command(
+            'brctl addbr {}'.format(
+                self.bridge_nic
+            )
+        )
+        common.run_os_command(
+            'brctl addif {} {}'.format(
+                self.bridge_nic,
+                self.vxlan_nic
+            )
+        )
+        common.run_os_command(
+            'ip link set {} up'.format(
+                self.vxlan_nic
+            )
+        )
+        common.run_os_command(
+            'ip link set {} up'.format(
+                self.bridge_nic
+            )
+        )
 
-    def createAddress(self):
+    def createGatewayAddress(self):
         if self.this_router.getnetworkstate() == 'primary':
-            ansiiprint.echo('Creating gateway {} on interface {} (VNI {})'.format(self.ip_gateway, self.bridge_nic, self.vni), '', 'o')
+            ansiiprint.echo(
-            common.run_os_command('ip address add {}/{} dev {}'.format(self.ip_gateway, self.ip_cidrnetmask, self.bridge_nic))
+                'Creating gateway {} on interface {} (VNI {})'.format(
-            common.run_os_command('arping -A -c2 -I {} {}'.format(self.bridge_nic, self.ip_gateway), background=True)
+                    self.ip_gateway,
+                    self.bridge_nic,
+                    self.vni
+                ),
+                '',
+                'o'
+            )
+            common.run_os_command(
+                'ip address add {}/{} dev {}'.format(
+                    self.ip_gateway,
+                    self.ip_cidrnetmask,
+                    self.bridge_nic
+                )
+            )
+            common.run_os_command(
+                'arping -A -c2 -I {} {}'.format(
+                    self.bridge_nic,
+                    self.ip_gateway
+                ),
+                background=True
+            )
+
+    def startDHCPServer(self):
+        if self.this_router.getnetworkstate() == 'primary':
+            ansiiprint.echo(
+                'Starting DHCP server on interface {} (VNI {})'.format(
+                    self.bridge_nic,
+                    self.vni
+                ),
+                '',
+                'o'
+            )
+            config = {
+                'ipaddr': self.ip_gateway,
+                'iface': self.bridge_nic,
+                'network': self.ip_network,
+                'router': [self.ip_gateway],
+                'dns_servers': [self.ip_gateway]
+            }
+            dhcp_configuration = DHCPServerConfiguration(config)
+            dhcp_configuration.debug = print
+            self.dhcp_server = DHCPServer.DHCPServer(dhcp_configuration)
+            self.dhcp_server.start()
 
     def removeNetwork(self):
-        ansiiprint.echo('Removing VNI {} device on interface {}'.format(self.vni, self.vni_dev), '', 'o')
+        ansiiprint.echo(
-        common.run_os_command('ip link set {} down'.format(self.bridge_nic))
+            'Removing VNI {} device on interface {}'.format(
-        common.run_os_command('ip link set {} down'.format(self.vxlan_nic))
+                self.vni,
-        common.run_os_command('brctl delif {} {}'.format(self.bridge_nic, self.vxlan_nic))
+                self.vni_dev
-        common.run_os_command('brctl delbr {}'.format(self.bridge_nic))
+            ),
-        common.run_os_command('ip link delete {}'.format(self.vxlan_nic))
+            '',
+            'o'
+        )
+        common.run_os_command(
+            'ip link set {} down'.format(
+                self.bridge_nic
+            )
+        )
+        common.run_os_command(
+            'ip link set {} down'.format(
+                self.vxlan_nic
+            )
+        )
+        common.run_os_command(
+            'brctl delif {} {}'.format(
+                self.bridge_nic,
+                self.vxlan_nic
+            )
+        )
+        common.run_os_command(
+            'brctl delbr {}'.format(
+                self.bridge_nic
+            )
+        )
+        common.run_os_command(
+            'ip link delete {}'.format(
+                self.vxlan_nic
+            )
+        )
 
-    def removeAddress(self):
+    def removeGatewayAddress(self):
-        ansiiprint.echo('Removing gateway {} from interface {} (VNI {})'.format(self.ip_gateway, self.bridge_nic, self.vni), '', 'o')
+        ansiiprint.echo(
-        common.run_os_command('ip address delete {}/{} dev {}'.format(self.ip_gateway, self.ip_cidrnetmask, self.bridge_nic))
+            'Removing gateway {} from interface {} (VNI {})'.format(
+                self.ip_gateway,
+                self.bridge_nic,
+                self.vni
+            ),
+            '',
+            'o'
+        )
+        common.run_os_command(
+            'ip address delete {}/{} dev {}'.format(
+                self.ip_gateway,
+                self.ip_cidrnetmask,
+                self.bridge_nic
+            )
+        )
+
+    def stopDHCPServer(self):
+        self.dhcp_server.close()