[189] | 1 | #!/usr/bin/python |
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| 2 | import pydhcplib |
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| 3 | from pydhcplib.dhcp_packet import * |
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| 4 | from pydhcplib.type_hw_addr import hwmac |
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| 5 | from pydhcplib.type_ipv4 import ipv4 |
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| 6 | |
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| 7 | from event_logger import Log |
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| 8 | |
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| 9 | import sipb_xen_database |
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| 10 | |
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| 11 | class DhcpBackend: |
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| 12 | def __init__(self, database=None): |
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| 13 | if database is not None: |
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| 14 | sipb_xen_database.connect(database) |
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| 15 | def findIP(self, mac): |
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| 16 | value = sipb_xen_database.NIC.get_by(mac_addr=mac) |
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| 17 | if value is None: |
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| 18 | return None |
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| 19 | ip = value.ip |
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| 20 | if ip is None: #Deactivated? |
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| 21 | return None |
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| 22 | return ip |
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| 23 | |
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| 24 | def Discover(self, packet): |
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| 25 | Log.Output(Log.debug,"dhcp_backend : Discover ") |
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| 26 | chaddr = hwmac(packet.GetHardwareAddress()) |
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| 27 | ip = self.findIP(str(chaddr)) |
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| 28 | if ip is not None: |
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| 29 | ip = ipv4(ip) |
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| 30 | Log.Output(Log.debug,"dhcp_backend : Discover result = "+str(ip)) |
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| 31 | packet_parameters = {} |
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| 32 | |
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| 33 | # FIXME: Other offer parameters go here |
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| 34 | packet_parameters["yiaddr"] = ip.list() |
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| 35 | |
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| 36 | packet.SetMultipleOptions(packet_parameters) |
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| 37 | return True |
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| 38 | return False |
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| 39 | |
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| 40 | def Request(self, packet): |
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| 41 | Log.Output(Log.debug, "dhcp_backend : Request") |
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| 42 | |
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| 43 | discover = self.Discover(packet) |
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| 44 | |
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| 45 | chaddr = hwmac(packet.GetHardwareAddress()) |
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| 46 | request = packet.GetOption("request_ip_address") |
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| 47 | yiaddr = packet.GetOption("yiaddr") |
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| 48 | |
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| 49 | if not discover: |
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| 50 | Log.Output(Log.info,"Unknown MAC address: "+str(chaddr)) |
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| 51 | return False |
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| 52 | |
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| 53 | if yiaddr!="0.0.0.0" and yiaddr == request : |
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| 54 | Log.Output(Log.info,"Ack ip "+str(yiaddr)+" for "+str(chaddr)) |
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| 55 | return True |
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| 56 | else: |
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| 57 | Log.Output(Log.info,"Requested ip "+str(request)+" not available for "+str(chaddr)) |
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| 58 | return False |
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| 59 | |
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| 60 | def Decline(self, packet): |
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| 61 | pass |
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| 62 | def Release(self, packet): |
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| 63 | pass |
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| 64 | |
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| 65 | |
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| 66 | class DhcpServer(pydhcplib.dhcp_network.DhcpServer): |
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| 67 | def __init__(self, backend, options = {'client_listenport':68,'server_listenport':67}): |
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| 68 | pydhcplib.dhcp_network.DhcpServer.__init__(self,"0.0.0.0",options["client_listen_port"],options["server_listen_port"],) |
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| 69 | self.backend = backend |
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| 70 | Log.Output(Log.debug, "__init__ DhcpServer") |
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| 71 | |
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| 72 | def SendPacket(self, packet): |
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| 73 | """Encode and send the packet.""" |
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| 74 | |
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| 75 | giaddr = packet.GetOption('giaddr') |
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| 76 | |
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| 77 | # in all case, if giaddr is set, send packet to relay_agent |
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| 78 | # network address defines by giaddr |
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| 79 | if giaddr!=[0,0,0,0] : |
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| 80 | agent_ip = ".".join(map(str,giaddr)) |
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| 81 | self.SendDhcpPacketTo(agent_ip,packet) |
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| 82 | Log.Output(Log.debug, "SendPacket to agent : "+agent_ip) |
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| 83 | |
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| 84 | # FIXME: This shouldn't broadcast if it has an IP address to send |
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| 85 | # it to instead. See RFC2131 part 4.1 for full details |
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| 86 | else : |
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| 87 | Log.Output(Log.debug, "No agent, broadcast packet.") |
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| 88 | self.SendDhcpPacketTo("255.255.255.255",packet) |
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| 89 | |
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| 90 | |
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| 91 | def HandleDhcpDiscover(self, packet): |
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| 92 | """Build and send DHCPOFFER packet in response to DHCPDISCOVER |
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| 93 | packet.""" |
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| 94 | |
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| 95 | logmsg = "Get DHCPDISCOVER packet from " + hwmac(packet.GetHardwareAddress()).str() |
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| 96 | |
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| 97 | Log.Output(Log.info, logmsg) |
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| 98 | offer = DhcpPacket() |
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| 99 | offer.CreateDhcpOfferPacketFrom(packet) |
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| 100 | |
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| 101 | if self.backend.Discover(offer) : |
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| 102 | self.SendPacket(offer) |
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| 103 | # FIXME : what if false ? |
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| 104 | |
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| 105 | |
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| 106 | def HandleDhcpRequest(self, packet): |
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| 107 | """Build and send DHCPACK or DHCPNACK packet in response to |
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| 108 | DHCPREQUEST packet. 4 types of DHCPREQUEST exists.""" |
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| 109 | |
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| 110 | ip = packet.GetOption("request_ip_address") |
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| 111 | sid = packet.GetOption("server_identifier") |
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| 112 | ciaddr = packet.GetOption("ciaddr") |
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| 113 | |
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| 114 | if sid != [0,0,0,0] and ciaddr == [0,0,0,0] : |
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| 115 | Log.Output(Log.info, "Get DHCPREQUEST_SELECTING_STATE packet") |
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| 116 | |
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| 117 | elif sid == [0,0,0,0] and ciaddr == [0,0,0,0] and ip : |
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| 118 | Log.Output(Log.info, "Get DHCPREQUEST_INITREBOOT_STATE packet") |
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| 119 | |
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| 120 | elif sid == [0,0,0,0] and ciaddr != [0,0,0,0] and not ip : |
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| 121 | Log.Output(Log.info,"Get DHCPREQUEST_INITREBOOT_STATE packet") |
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| 122 | |
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| 123 | else : Log.Output(Log.info,"Get DHCPREQUEST_UNKNOWN_STATE packet : not implemented") |
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| 124 | |
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| 125 | if self.backend.Request(packet) : packet.TransformToDhcpAckPacket() |
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| 126 | else : packet.TransformToDhcpNackPacket() |
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| 127 | |
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| 128 | self.SendPacket(packet) |
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| 129 | |
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| 130 | |
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| 131 | |
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| 132 | # FIXME: These are not yet implemented. |
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| 133 | def HandleDhcpDecline(self, packet): |
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| 134 | Log.Output(Log.info, "Get DHCPDECLINE packet") |
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| 135 | self.backend.Decline(packet) |
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| 136 | |
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| 137 | def HandleDhcpRelease(self, packet): |
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| 138 | Log.Output(Log.info,"Get DHCPRELEASE packet") |
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| 139 | self.backend.Release(packet) |
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| 140 | |
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| 141 | def HandleDhcpInform(self, packet): |
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| 142 | Log.Output(Log.info, "Get DHCPINFORM packet") |
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| 143 | |
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| 144 | if self.backend.Request(packet) : |
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| 145 | packet.TransformToDhcpAckPacket() |
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| 146 | # FIXME : Remove lease_time from options |
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| 147 | self.SendPacket(packet) |
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| 148 | |
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| 149 | # FIXME : what if false ? |
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| 150 | |
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| 151 | if '__main__' == __name__: |
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| 152 | event_logger.init("stdout", event_logger.INFO, {}) |
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| 153 | options = { "server_listen_port":67, |
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| 154 | "client_listen_port":68, |
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| 155 | "listen_address":"0.0.0.0"} |
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| 156 | backend = DhcpBackend('postgres://sipb-xen@sipb-xen-dev/sipb_xen') |
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| 157 | server = DhcpServer(backend, options) |
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| 158 | |
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| 159 | while True : server.GetNextDhcpPacket() |
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