X-Git-Url: http://xvm.mit.edu/gitweb/invirt/packages/invirt-dhcp.git/blobdiff_plain/ae56a450592fdfe3645985146e18e55689df00be..fd213377362505a504e1d100e497949b84d5ead7:/invirt-dhcpserver diff --git a/invirt-dhcpserver b/invirt-dhcpserver index ffbf839..e049f15 100755 --- a/invirt-dhcpserver +++ b/invirt-dhcpserver @@ -8,6 +8,10 @@ from pydhcplib.type_ipv4 import ipv4 from pydhcplib.type_strlist import strlist import socket import IN +from Queue import Queue +from threading import Thread +from subprocess import PIPE, Popen +import netifaces as ni import syslog as s @@ -15,23 +19,24 @@ import time from invirt import database from invirt.config import structs as config -dhcp_options = {'subnet_mask': config.dhcp.netmask, - 'router': config.dhcp.gateway, - 'domain_name_server': ','.join(config.dhcp.dns), - 'ip_address_lease_time': 60*60*24} +dhcp_options = {'domain_name_server': ','.join(config.dhcp.dns), + 'ip_address_lease_time': config.dhcp.get('leasetime', 60*60*24)} class DhcpBackend: - def __init__(self): + def __init__(self, queue): database.connect() + self.queue = queue def findNIC(self, mac): database.clear_cache() - return database.NIC.query().filter_by(mac_addr=mac).first() + return database.NIC.query.filter_by(mac_addr=mac).first() def find_interface(self, packet): chaddr = hwmac(packet.GetHardwareAddress()) nic = self.findNIC(str(chaddr)) + return self.find_interface_by_nic(nic) + def find_interface_by_nic(self, nic): if nic is None or nic.ip is None: return None - ipstr = ''.join(reversed(['%02X' % i for i in ipv4(nic.ip).list()])) + ipstr = ''.join(reversed(['%02X' % i for i in ipv4(nic.ip.encode("utf-8")).list()])) for line in open('/proc/net/route'): parts = line.split() if parts[1] == ipstr: @@ -97,15 +102,17 @@ class DhcpBackend: nic = self.findNIC(str(chaddr)) if nic is None or nic.machine is None: return False - ip = nic.ip + ip = nic.ip.encode("utf-8") if ip is None: #Deactivated? return False options = {} + options['subnet_mask'] = nic.netmask.encode("utf-8") + options['router'] = nic.gateway.encode("utf-8") if nic.hostname and '.' in nic.hostname: - options['host_name'], options['domain_name'] = nic.hostname.split('.', 1) + options['host_name'], options['domain_name'] = nic.hostname.encode('utf-8').split('.', 1) elif nic.machine.name: - options['host_name'] = nic.machine.name + options['host_name'] = nic.machine.name.encode('utf-8') options['domain_name'] = config.dns.domains[0] else: hostname = None @@ -113,17 +120,15 @@ class DhcpBackend: options['host_name'] += '.' + options['domain_name'] del options['domain_name'] options['domain_search'] = [config.dhcp.search_domain] - if ip is not None: - ip = ipv4(ip) - s.syslog(s.LOG_DEBUG,"dhcp_backend : Discover result = "+str(ip)) - packet_parameters = self.getParameters(**options) + ip = ipv4(ip) + s.syslog(s.LOG_DEBUG,"dhcp_backend : Discover result = "+str(ip)) + packet_parameters = self.getParameters(**options) - # FIXME: Other offer parameters go here - packet_parameters["yiaddr"] = ip.list() - - packet.SetMultipleOptions(packet_parameters) - return True - return False + # FIXME: Other offer parameters go here + packet_parameters["yiaddr"] = ip.list() + + packet.SetMultipleOptions(packet_parameters) + return True def Request(self, packet): s.syslog(s.LOG_DEBUG, "dhcp_backend : Request") @@ -142,6 +147,94 @@ class DhcpBackend: if yiaddr!="0.0.0.0" and yiaddr == request : s.syslog(s.LOG_INFO,"Ack ip "+str(yiaddr)+" for "+str(chaddr)) + n = self.findNIC(str(chaddr)) + intf = self.find_interface_by_nic(n) + main_ip = ni.ifaddresses(config.xen.iface)[ni.AF_INET][0]['addr'] + s.syslog(s.LOG_ERR, "Interface is %s" % (intf)) + # Don't perform "other" actions if the machine isn't running + other_action = n.other_action if n.other_action and intf else '' + if other_action in ('renumber', 'renumber_dhcp'): + (n.ip, n.netmask, n.gateway, n.other_ip, n.other_netmask, + n.other_gateway) = ( + n.other_ip, n.other_netmask, n.other_gateway, n.ip, + n.netmask, n.gateway) + other_action = n.other_action = 'dnat' + database.session.add(n) + database.session.flush() + if other_action == 'dnat': + # If the machine was booted in 'dnat' mode, then both + # routes were already added by the invirt-database script. + # If the machine was already on and has just been set to + # 'dnat' mode, we need to add the route for the 'other' IP. + # If the machine has just been 'renumbered' by us above, + # the IPs will be swapped and only the route for the main + # IP needs to be added. Just try adding both of them, and + # arp for whichever of them turns out to be new. + for parms in [(n.ip, n.gateway), (n.other_ip, n.other_gateway)]: + try: + p = Popen(['ip', 'route', 'add', parms[0], 'dev', intf, 'src', main_ip, 'metric', '2' if intf.startswith('vif') else '1'], stdout=PIPE, stderr=PIPE) + (out, err) = p.communicate() + if p.returncode == 0: + s.syslog(s.LOG_INFO, "Added route for IP %s to interface %s" % (parms[0], intf)) + self.queue.put(parms) + sys.stderr.write(err) + sys.stdout.write(out) + except Exception as e: + s.syslog(s.LOG_ERR, "Could not add route for IP %s: %s" % (parms[0], e)) + try: + # iptables will let you add the same rule again and again; + # let's not do that. + p = Popen(['iptables', '-t', 'nat', '-C', 'PREROUTING', '-d', n.other_ip, '-j', 'DNAT', '--to-destination', n.ip], stdout=PIPE, stderr=PIPE) + (out, err) = p.communicate() + sys.stderr.write(err) + sys.stdout.write(out) + if p.returncode != 0: + p2 = Popen(['iptables', '-t', 'nat', '-A', 'PREROUTING', '-d', n.other_ip, '-j', 'DNAT', '--to-destination', n.ip], stdout=PIPE, stderr=PIPE) + (out, err) = p2.communicate() + sys.stderr.write(err) + sys.stdout.write(out) + if p2.returncode == 0: + s.syslog(s.LOG_INFO, "Added DNAT for IP %s to %s" % (n.other_ip, n.ip)) + else: + s.syslog(s.LOG_ERR, "Could not add DNAT for IP %s to %s" % (n.other_ip, n.ip)) + except Exception as e: + s.syslog(s.LOG_ERR, "Could not check and/or add DNAT for IP %s to %s: %s" % (n.other_ip, n.ip, e)) + if other_action == 'remove': + try: + p = Popen(['ip', 'route', 'del', n.other_ip, 'dev', intf, 'src', main_ip], stdout=PIPE, stderr=PIPE) + (out, err) = p.communicate() + sys.stderr.write(err) + sys.stderr.write(out) + if p.returncode == 0: + s.syslog(s.LOG_INFO, "Removed route for IP %s" % (n.other_ip)) + else: + s.syslog(s.LOG_ERR, "Could not remove route for IP %s" % (n.other_ip)) + except Exception as e: + s.syslog(s.LOG_ERR, "Could not run ip to remove route for IP %s: %s" % (n.other_ip, e)) + try: + p = Popen(['iptables', '-t', 'nat', '-D', 'PREROUTING', '-d', n.other_ip, '-j', 'DNAT', '--to-destination', n.ip], stdout=PIPE, stderr=PIPE) + (out, err) = p.communicate() + sys.stderr.write(err) + sys.stdout.write(out) + if p.returncode == 0: + s.syslog(s.LOG_INFO, "Removed DNAT for IP %s" % (n.other_ip)) + else: + s.syslog(s.LOG_ERR, "Could not remove DNAT for IP %s" % (n.other_ip)) + except Exception as e: + s.syslog(s.LOG_ERR, "Could not run iptables to remove DNAT for IP %s: %s" % (n.other_ip, e)) + n.other_ip = n.other_netmask = n.other_gateway = n.other_action = None + database.session.add(n) + database.session.flush() + # We went through the DISCOVER codepath already to populate some + # of the packet's parameters. If we renumbered the VM just above, + # the packet is set to offer them what they asked for - the old + # address. So, we'll send then a DHCPNACK and they'll come right + # back and be offered the new address. The code above won't be + # able to add duplicate routes, won't insert a duplicate DNAT, + # and won't ARP again because the routes will exist, so this won't + # incur much extra work. + if request != map(int, n.ip.split('.')): + return False return True else: s.syslog(s.LOG_INFO,"Requested ip "+str(request)+" not available for "+str(chaddr)) @@ -252,6 +345,28 @@ class DhcpServer(pydhcplib.dhcp_network.DhcpServer): # FIXME : what if false ? +class ArpspoofWorker(Thread): + def __init__(self, queue): + Thread.__init__(self) + self.queue = queue + self.iface = config.xen.iface + + def run(self): + while True: + (ip, gw) = self.queue.get() + try: + p = Popen(['timeout', '5', 'arpspoof', '-i', self.iface, '-t', gw, ip], stdout=PIPE, stderr=PIPE) + (out, err) = p.communicate() + if p.returncode != 124: + s.syslog(s.LOG_ERR, "arpspoof returned %s for IP %s gateway %s" % (p.returncode, ip, gw)) + else: + s.syslog(s.LOG_INFO, "aprspoof'd for IP %s gateway %s" % (ip, gw)) + sys.stderr.write(err) + sys.stdout.write(out) + except Exception as e: + s.syslog(s.LOG_ERR, "Could not run arpspoof for IP %s gateway %s: %s" % (ip, gw, e)) + self.queue.task_done() + if '__main__' == __name__: options = { "server_listen_port":67, "client_listen_port":68, @@ -262,9 +377,16 @@ if '__main__' == __name__: print "invirt-dhcpserver: cannot determine local IP address by looking up %s" % socket.gethostname() sys.exit(1) - dhcp_options['server_identifier'] = myip + dhcp_options['server_identifier'] = ipv4(myip).int() + + queue = Queue() - backend = DhcpBackend() + backend = DhcpBackend(queue) server = DhcpServer(backend, options) + for x in range(2): + worker = ArpspoofWorker(queue) + worker.daemon = True + worker.start() + while True : server.GetNextDhcpPacket()