X-Git-Url: http://xvm.mit.edu/gitweb/invirt/packages/invirt-dhcp.git/blobdiff_plain/377cd6bb3cdbf4b23e7cf6b8ca5d0a9f21fb36bb..f850bd4f861c148b655ea57e66920e4107d5cdca:/dhcpserver.py diff --git a/dhcpserver.py b/dhcpserver.py index 5c7721c..6171843 100644 --- a/dhcpserver.py +++ b/dhcpserver.py @@ -1,34 +1,121 @@ #!/usr/bin/python +import sys +sys.path.append('pydhcplib/') import pydhcplib +import pydhcplib.dhcp_network from pydhcplib.dhcp_packet import * from pydhcplib.type_hw_addr import hwmac from pydhcplib.type_ipv4 import ipv4 +from pydhcplib.type_strlist import strlist +import socket +import IN +import event_logger +if '__main__' == __name__: + event_logger.init("stdout", 'DEBUG', {}) from event_logger import Log +import psycopg2 +import time import sipb_xen_database +from sqlalchemy import create_engine + +dhcp_options = {'subnet_mask': '255.255.0.0', + 'router': '18.181.0.1', + 'domain_name_server': '18.70.0.160,18.71.0.151,18.72.0.3', + 'domain_name': 'mit.edu', + 'ip_address_lease_time': 60*60*24} class DhcpBackend: def __init__(self, database=None): if database is not None: - sipb_xen_database.connect(database) - def findIP(self, mac): - value = sipb_xen_database.NIC.get_by(mac_addr=mac) - if value is None: - return None - ip = value.ip - if ip is None: #Deactivated? - return None - return ip + self.database = database + sipb_xen_database.connect(create_engine(database)) + def findNIC(self, mac): + for i in range(3): + try: + value = sipb_xen_database.NIC.get_by(mac_addr=mac) + except psycopg2.OperationalError: + time.sleep(0.5) + if i == 2: #Try twice to reconnect. + raise + #Sigh. SQLAlchemy should do this itself. + sipb_xen_database.connect(create_engine(self.database)) + else: + break + return value + def find_interface(self, packet): + chaddr = hwmac(packet.GetHardwareAddress()) + nic = self.findNIC(str(chaddr)) + if nic is None or nic.ip is None: + return ("18.181.0.60", None) + ipstr = ''.join(reversed(['%02X' % i for i in ipv4(nic.ip).list()])) + for line in open('/proc/net/route'): + parts = line.split() + if parts[1] == ipstr: + Log.Output(Log.debug, "find_interface found "+str(nic.ip)+" on "+parts[0]) + return ("18.181.0.60", parts[0]) + return ("18.181.0.60", None) + + def getParameters(self, **extra): + all_options=dict(dhcp_options) + all_options.update(extra) + options = {} + for parameter, value in all_options.iteritems(): + if value is None: + continue + option_type = DhcpOptionsTypes[DhcpOptions[parameter]] + + if option_type == "ipv4" : + # this is a single ip address + options[parameter] = map(int,value.split(".")) + elif option_type == "ipv4+" : + # this is multiple ip address + iplist = value.split(",") + opt = [] + for single in iplist : + opt.extend(ipv4(single).list()) + options[parameter] = opt + elif option_type == "32-bits" : + # This is probably a number... + digit = int(value) + options[parameter] = [digit>>24&0xFF,(digit>>16)&0xFF,(digit>>8)&0xFF,digit&0xFF] + elif option_type == "16-bits" : + digit = int(value) + options[parameter] = [(digit>>8)&0xFF,digit&0xFF] + + elif option_type == "char" : + digit = int(value) + options[parameter] = [digit&0xFF] + + elif option_type == "bool" : + if value=="False" or value=="false" or value==0 : + options[parameter] = [0] + else : options[parameter] = [1] + + elif option_type == "string" : + options[parameter] = strlist(value).list() + + else : + options[parameter] = strlist(value).list() + return options def Discover(self, packet): Log.Output(Log.debug,"dhcp_backend : Discover ") chaddr = hwmac(packet.GetHardwareAddress()) - ip = self.findIP(str(chaddr)) + nic = self.findNIC(str(chaddr)) + if nic is None: + return False + ip = nic.ip + if ip is None: #Deactivated? + return False + hostname = nic.hostname + if hostname is not None: + hostname += ".servers.csail.mit.edu" if ip is not None: ip = ipv4(ip) Log.Output(Log.debug,"dhcp_backend : Discover result = "+str(ip)) - packet_parameters = {} + packet_parameters = self.getParameters(host_name=hostname) # FIXME: Other offer parameters go here packet_parameters["yiaddr"] = ip.list() @@ -44,6 +131,8 @@ class DhcpBackend: chaddr = hwmac(packet.GetHardwareAddress()) request = packet.GetOption("request_ip_address") + if not request: + request = packet.GetOption("ciaddr") yiaddr = packet.GetOption("yiaddr") if not discover: @@ -69,8 +158,21 @@ class DhcpServer(pydhcplib.dhcp_network.DhcpServer): self.backend = backend Log.Output(Log.debug, "__init__ DhcpServer") + def SendDhcpPacketTo(self, To, packet): + (ip, intf) = self.backend.find_interface(packet) + if intf: + out_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) + out_socket.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST,1) + out_socket.setsockopt(socket.SOL_SOCKET, IN.SO_BINDTODEVICE, intf) + #out_socket.bind((ip, self.listen_port)) + ret = out_socket.sendto(packet.EncodePacket(), (To,self.emit_port)) + out_socket.close() + return ret + else: + return self.dhcp_socket.sendto(packet.EncodePacket(),(To,self.emit_port)) + def SendPacket(self, packet): - """Encode and send the packet.""" + """Encode and send the packet.""" giaddr = packet.GetOption('giaddr') @@ -98,7 +200,7 @@ class DhcpServer(pydhcplib.dhcp_network.DhcpServer): offer = DhcpPacket() offer.CreateDhcpOfferPacketFrom(packet) - if self.backend.Discover(offer) : + if self.backend.Discover(offer): self.SendPacket(offer) # FIXME : what if false ? @@ -110,6 +212,8 @@ class DhcpServer(pydhcplib.dhcp_network.DhcpServer): ip = packet.GetOption("request_ip_address") sid = packet.GetOption("server_identifier") ciaddr = packet.GetOption("ciaddr") + #packet.PrintHeaders() + #packet.PrintOptions() if sid != [0,0,0,0] and ciaddr == [0,0,0,0] : Log.Output(Log.info, "Get DHCPREQUEST_SELECTING_STATE packet") @@ -149,7 +253,6 @@ class DhcpServer(pydhcplib.dhcp_network.DhcpServer): # FIXME : what if false ? if '__main__' == __name__: - event_logger.init("stdout", event_logger.INFO, {}) options = { "server_listen_port":67, "client_listen_port":68, "listen_address":"0.0.0.0"}