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#!/usr/bin/env python |
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# |
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|
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# nfdcpd: A promiscuous, NFQUEUE-based DHCP server for virtual machine hosting |
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# Copyright (c) 2010 GRNET SA |
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# |
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# This program is free software; you can redistribute it and/or modify |
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# it under the terms of the GNU General Public License as published by |
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# the Free Software Foundation; either version 2 of the License, or |
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# (at your option) any later version. |
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# |
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# This program is distributed in the hope that it will be useful, |
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# but WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU General Public License for more details. |
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# |
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# You should have received a copy of the GNU General Public License along |
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# with this program; if not, write to the Free Software Foundation, Inc., |
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# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
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# |
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|
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import os |
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import re |
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import sys |
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import glob |
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import time |
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import logging |
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import logging.handlers |
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import threading |
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import traceback |
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import subprocess |
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|
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import daemon |
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import daemon.pidlockfile |
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import nfqueue |
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import pyinotify |
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|
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import IPy |
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import socket |
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from select import select |
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from socket import AF_INET, AF_INET6 |
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|
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from scapy.data import ETH_P_ALL |
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from scapy.packet import BasePacket |
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from scapy.layers.l2 import Ether |
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from scapy.layers.inet import IP, UDP |
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from scapy.layers.inet6 import IPv6, ICMPv6ND_RA, ICMPv6ND_NA, \ |
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ICMPv6NDOptDstLLAddr, \ |
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ICMPv6NDOptPrefixInfo, \ |
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ICMPv6NDOptRDNSS |
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from scapy.layers.dhcp import BOOTP, DHCP |
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|
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DEFAULT_CONFIG = "/etc/nfdhcpd/nfdhcpd.conf" |
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DEFAULT_PATH = "/var/run/ganeti-dhcpd" |
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DEFAULT_USER = "nobody" |
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DEFAULT_LEASE_LIFETIME = 604800 # 1 week |
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DEFAULT_LEASE_RENEWAL = 600 # 10 min |
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DEFAULT_RA_PERIOD = 300 # seconds |
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DHCP_DUMMY_SERVER_IP = "1.2.3.4" |
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|
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LOG_FILENAME = "nfdhcpd.log" |
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|
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SYSFS_NET = "/sys/class/net" |
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|
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LOG_FORMAT = "%(asctime)-15s %(levelname)-6s %(message)s" |
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|
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# Configuration file specification (see configobj documentation) |
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CONFIG_SPEC = """ |
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[general] |
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pidfile = string() |
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datapath = string() |
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logdir = string() |
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user = string() |
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|
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[dhcp] |
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enable_dhcp = boolean(default=True) |
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lease_lifetime = integer(min=0, max=4294967295) |
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lease_renewal = integer(min=0, max=4294967295) |
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server_ip = ip_addr() |
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dhcp_queue = integer(min=0, max=65535) |
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nameservers = ip_addr_list(family=4) |
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|
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[ipv6] |
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enable_ipv6 = boolean(default=True) |
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ra_period = integer(min=1, max=4294967295) |
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rs_queue = integer(min=0, max=65535) |
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ns_queue = integer(min=0, max=65535) |
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nameservers = ip_addr_list(family=6) |
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""" |
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|
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|
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DHCPDISCOVER = 1 |
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DHCPOFFER = 2 |
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DHCPREQUEST = 3 |
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DHCPDECLINE = 4 |
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DHCPACK = 5 |
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DHCPNAK = 6 |
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DHCPRELEASE = 7 |
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DHCPINFORM = 8 |
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|
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DHCP_TYPES = { |
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DHCPDISCOVER: "DHCPDISCOVER", |
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DHCPOFFER: "DHCPOFFER", |
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DHCPREQUEST: "DHCPREQUEST", |
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DHCPDECLINE: "DHCPDECLINE", |
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DHCPACK: "DHCPACK", |
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DHCPNAK: "DHCPNAK", |
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DHCPRELEASE: "DHCPRELEASE", |
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DHCPINFORM: "DHCPINFORM", |
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} |
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|
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DHCP_REQRESP = { |
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DHCPDISCOVER: DHCPOFFER, |
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DHCPREQUEST: DHCPACK, |
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DHCPINFORM: DHCPACK, |
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} |
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|
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|
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def parse_binding_file(path): |
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""" Read a client configuration from a tap file |
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|
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""" |
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try: |
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iffile = open(path, 'r') |
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except EnvironmentError, e: |
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logging.warn("Unable to open binding file %s: %s", path, str(e)) |
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return None |
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|
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tap = os.path.basename(path) |
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indev = None |
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mac = None |
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ips = None |
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hostname = None |
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subnet = None |
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gateway = None |
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subnet6 = None |
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gateway6 = None |
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eui64 = None |
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|
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for line in iffile: |
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if line.startswith("IP="): |
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ip = line.strip().split("=")[1] |
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ips = ip.split() |
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elif line.startswith("MAC="): |
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mac = line.strip().split("=")[1] |
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elif line.startswith("HOSTNAME="): |
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hostname = line.strip().split("=")[1] |
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elif line.startswith("INDEV="): |
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indev = line.strip().split("=")[1] |
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elif line.startswith("SUBNET="): |
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subnet = line.strip().split("=")[1] |
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elif line.startswith("GATEWAY="): |
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gateway = line.strip().split("=")[1] |
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elif line.startswith("SUBNET6="): |
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subnet6 = line.strip().split("=")[1] |
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elif line.startswith("GATEWAY6="): |
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gateway6 = line.strip().split("=")[1] |
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elif line.startswith("EUI64="): |
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eui64 = line.strip().split("=")[1] |
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|
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return Client(tap=tap, mac=mac, ips=ips, |
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hostname=hostname, indev=indev, subnet=subnet, |
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gateway=gateway, subnet6=subnet6, gateway6=gateway6, eui64=eui64 ) |
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|
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class ClientFileHandler(pyinotify.ProcessEvent): |
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def __init__(self, server): |
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pyinotify.ProcessEvent.__init__(self) |
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self.server = server |
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|
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def process_IN_DELETE(self, event): # pylint: disable=C0103 |
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""" Delete file handler |
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|
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Currently this removes an interface from the watch list |
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|
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""" |
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self.server.remove_tap(event.name) |
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|
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def process_IN_CLOSE_WRITE(self, event): # pylint: disable=C0103 |
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""" Add file handler |
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|
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Currently this adds an interface to the watch list |
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|
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""" |
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self.server.add_tap(os.path.join(event.path, event.name)) |
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|
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|
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class Client(object): |
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def __init__(self, tap=None, indev=None, mac=None, ips=None, hostname=None, |
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subnet=None, gateway=None, subnet6=None, gateway6=None, eui64=None ): |
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self.mac = mac |
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self.ips = ips |
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self.hostname = hostname |
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self.indev = indev |
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self.tap = tap |
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self.subnet = subnet |
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self.gateway = gateway |
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self.net = Subnet(net=subnet, gw=gateway, dev=tap) |
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self.subnet6 = subnet6 |
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self.gateway6 = gateway6 |
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self.net6 = Subnet(net=subnet6, gw=gateway6, dev=tap) |
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self.eui64 = eui64 |
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|
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@property |
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def ip(self): |
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return self.ips[0] |
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|
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def is_valid(self): |
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return self.mac is not None and self.ips is not None\ |
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and self.hostname is not None |
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|
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|
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class Subnet(object): |
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def __init__(self, net=None, gw=None, dev=None): |
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if isinstance(net, str): |
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self.net = IPy.IP(net) |
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else: |
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self.net = net |
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self.gw = gw |
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self.dev = dev |
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|
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@property |
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def netmask(self): |
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""" Return the netmask in textual representation |
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|
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""" |
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return str(self.net.netmask()) |
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|
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@property |
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def broadcast(self): |
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""" Return the broadcast address in textual representation |
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|
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""" |
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return str(self.net.broadcast()) |
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|
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@property |
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def prefix(self): |
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""" Return the network as an IPy.IP |
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|
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""" |
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return self.net.net() |
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|
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@property |
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def prefixlen(self): |
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""" Return the prefix length as an integer |
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|
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""" |
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return self.net.prefixlen() |
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|
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@staticmethod |
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def _make_eui64(net, mac): |
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""" Compute an EUI-64 address from an EUI-48 (MAC) address |
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|
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""" |
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comp = mac.split(":") |
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prefix = IPy.IP(net).net().strFullsize().split(":")[:4] |
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eui64 = comp[:3] + ["ff", "fe"] + comp[3:] |
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eui64[0] = "%02x" % (int(eui64[0], 16) ^ 0x02) |
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for l in range(0, len(eui64), 2): |
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prefix += ["".join(eui64[l:l+2])] |
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return IPy.IP(":".join(prefix)) |
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|
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def make_eui64(self, mac): |
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""" Compute an EUI-64 address from an EUI-48 (MAC) address in this |
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subnet. |
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|
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""" |
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return self._make_eui64(self.net, mac) |
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|
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def make_ll64(self, mac): |
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""" Compute an IPv6 Link-local address from an EUI-48 (MAC) address |
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|
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""" |
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return self._make_eui64("fe80::", mac) |
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|
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|
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class VMNetProxy(object): # pylint: disable=R0902 |
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def __init__(self, data_path, dhcp_queue_num=None, # pylint: disable=R0913 |
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rs_queue_num=None, ns_queue_num=None, |
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dhcp_lease_lifetime=DEFAULT_LEASE_LIFETIME, |
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dhcp_lease_renewal=DEFAULT_LEASE_RENEWAL, |
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dhcp_server_ip=DHCP_DUMMY_SERVER_IP, dhcp_nameservers=None, |
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ra_period=DEFAULT_RA_PERIOD, ipv6_nameservers=None): |
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|
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self.data_path = data_path |
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self.lease_lifetime = dhcp_lease_lifetime |
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self.lease_renewal = dhcp_lease_renewal |
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self.dhcp_server_ip = dhcp_server_ip |
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self.ra_period = ra_period |
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if dhcp_nameservers is None: |
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self.dhcp_nameserver = [] |
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else: |
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self.dhcp_nameservers = dhcp_nameservers |
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|
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if ipv6_nameservers is None: |
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self.ipv6_nameservers = [] |
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else: |
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self.ipv6_nameservers = ipv6_nameservers |
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|
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self.ipv6_enabled = False |
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|
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self.clients = {} |
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#self.subnets = {} |
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#self.ifaces = {} |
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#self.v6nets = {} |
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self.nfq = {} |
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self.l2socket = socket.socket(socket.AF_PACKET, |
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socket.SOCK_RAW, ETH_P_ALL) |
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self.l2socket.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 0) |
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|
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# Inotify setup |
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self.wm = pyinotify.WatchManager() |
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mask = pyinotify.EventsCodes.ALL_FLAGS["IN_DELETE"] |
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mask |= pyinotify.EventsCodes.ALL_FLAGS["IN_CLOSE_WRITE"] |
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inotify_handler = ClientFileHandler(self) |
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self.notifier = pyinotify.Notifier(self.wm, inotify_handler) |
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self.wm.add_watch(self.data_path, mask, rec=True) |
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|
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# NFQUEUE setup |
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if dhcp_queue_num is not None: |
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self._setup_nfqueue(dhcp_queue_num, AF_INET, self.dhcp_response) |
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|
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if rs_queue_num is not None: |
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self._setup_nfqueue(rs_queue_num, AF_INET6, self.rs_response) |
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self.ipv6_enabled = True |
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|
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if ns_queue_num is not None: |
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self._setup_nfqueue(ns_queue_num, AF_INET6, self.ns_response) |
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self.ipv6_enabled = True |
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|
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def _cleanup(self): |
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""" Free all resources for a graceful exit |
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|
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""" |
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logging.info("Cleaning up") |
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|
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logging.debug("Closing netfilter queues") |
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for q in self.nfq.values(): |
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q.close() |
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|
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logging.debug("Closing socket") |
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self.l2socket.close() |
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|
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logging.debug("Stopping inotify watches") |
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self.notifier.stop() |
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|
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logging.info("Cleanup finished") |
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|
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def _setup_nfqueue(self, queue_num, family, callback): |
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logging.debug("Setting up NFQUEUE for queue %d, AF %s", |
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queue_num, family) |
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q = nfqueue.queue() |
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q.set_callback(callback) |
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q.fast_open(queue_num, family) |
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q.set_queue_maxlen(5000) |
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# This is mandatory for the queue to operate |
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q.set_mode(nfqueue.NFQNL_COPY_PACKET) |
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self.nfq[q.get_fd()] = q |
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|
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def sendp(self, data, dev): |
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""" Send a raw packet using a layer-2 socket |
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|
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""" |
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logging.debug("%s", data) |
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if isinstance(data, BasePacket): |
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data = str(data) |
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|
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self.l2socket.bind((dev, ETH_P_ALL)) |
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count = self.l2socket.send(data) |
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ldata = len(data) |
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if count != ldata: |
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logging.warn("Truncated send on %s (%d/%d bytes sent)", |
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dev, count, ldata) |
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|
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def build_config(self): |
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self.clients.clear() |
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|
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for path in glob.glob(os.path.join(self.data_path, "*")): |
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self.add_tap(path) |
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|
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def get_ifindex(self, iface): |
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""" Get the interface index from sysfs |
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|
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""" |
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path = os.path.abspath(os.path.join(SYSFS_NET, iface, "ifindex")) |
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if not path.startswith(SYSFS_NET): |
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return None |
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|
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ifindex = None |
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|
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try: |
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f = open(path, 'r') |
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except EnvironmentError: |
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logging.debug("%s is probably down, removing", iface) |
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self.remove_tap(iface) |
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|
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return ifindex |
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|
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try: |
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ifindex = f.readline().strip() |
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try: |
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ifindex = int(ifindex) |
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except ValueError, e: |
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logging.warn("Failed to get ifindex for %s, cannot parse sysfs" |
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" output '%s'", iface, ifindex) |
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except EnvironmentError, e: |
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logging.warn("Error reading %s's ifindex from sysfs: %s", |
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iface, str(e)) |
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self.remove_tap(iface) |
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finally: |
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f.close() |
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|
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return ifindex |
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|
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|
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def get_iface_hw_addr(self, iface): |
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""" Get the interface hardware address from sysfs |
417 |
|
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""" |
419 |
path = os.path.abspath(os.path.join(SYSFS_NET, iface, "address")) |
420 |
if not path.startswith(SYSFS_NET): |
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return None |
422 |
|
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addr = None |
424 |
try: |
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f = open(path, 'r') |
426 |
except EnvironmentError: |
427 |
logging.debug("%s is probably down, removing", iface) |
428 |
self.remove_tap(iface) |
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return addr |
430 |
|
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try: |
432 |
addr = f.readline().strip() |
433 |
except EnvironmentError, e: |
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logging.warn("Failed to read hw address for %s from sysfs: %s", |
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iface, str(e)) |
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finally: |
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f.close() |
438 |
|
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return addr |
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|
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def add_tap(self, path): |
442 |
""" Add an interface to monitor |
443 |
|
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""" |
445 |
tap = os.path.basename(path) |
446 |
|
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logging.debug("Updating configuration for %s", tap) |
448 |
binding = parse_binding_file(path) |
449 |
if binding is None: |
450 |
return |
451 |
ifindex = self.get_ifindex(binding.indev) |
452 |
|
453 |
if ifindex is None: |
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logging.warn("Stale configuration for %s found", tap) |
455 |
else: |
456 |
if binding.is_valid(): |
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self.clients[binding.mac] = binding |
458 |
logging.debug("Added client %s on %s", binding.hostname, tap) |
459 |
logging.debug("clients %s", self.clients.keys()) |
460 |
|
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def remove_tap(self, tap): |
462 |
""" Cleanup clients on a removed interface |
463 |
|
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""" |
465 |
for b in self.clients.values(): |
466 |
if b.tap == tap: |
467 |
del b |
468 |
|
469 |
logging.debug("Removed interface %s", tap) |
470 |
|
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def dhcp_response(self, i, payload): # pylint: disable=W0613,R0914 |
472 |
""" Generate a reply to bnetfilter-queue-deva BOOTP/DHCP request |
473 |
|
474 |
""" |
475 |
# Decode the response - NFQUEUE relays IP packets |
476 |
pkt = IP(payload.get_data()) |
477 |
|
478 |
# Get the client MAC address |
479 |
resp = pkt.getlayer(BOOTP).copy() |
480 |
hlen = resp.hlen |
481 |
mac = resp.chaddr[:hlen].encode("hex") |
482 |
mac, _ = re.subn(r'([0-9a-fA-F]{2})', r'\1:', mac, hlen-1) |
483 |
|
484 |
# Server responses are always BOOTREPLYs |
485 |
resp.op = "BOOTREPLY" |
486 |
del resp.payload |
487 |
|
488 |
try: |
489 |
binding = self.clients[mac] |
490 |
except KeyError: |
491 |
logging.warn("Invalid client for mac %s ", mac) |
492 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
493 |
return |
494 |
|
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# Signal the kernel that it shouldn't further process the packet |
496 |
payload.set_verdict(nfqueue.NF_DROP) |
497 |
|
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resp = Ether(dst=mac, src=self.get_iface_hw_addr(binding.indev))/\ |
499 |
IP(src=DHCP_DUMMY_SERVER_IP, dst=binding.ip)/\ |
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UDP(sport=pkt.dport, dport=pkt.sport)/resp |
501 |
subnet = binding.net |
502 |
|
503 |
if not DHCP in pkt: |
504 |
logging.warn("Invalid request from %s on %s, no DHCP" |
505 |
" payload found", binding.mac, binding.tap) |
506 |
return |
507 |
|
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dhcp_options = [] |
509 |
requested_addr = binding.ip |
510 |
for opt in pkt[DHCP].options: |
511 |
if type(opt) is tuple and opt[0] == "message-type": |
512 |
req_type = opt[1] |
513 |
if type(opt) is tuple and opt[0] == "requested_addr": |
514 |
requested_addr = opt[1] |
515 |
|
516 |
logging.info("%s from %s on %s", DHCP_TYPES.get(req_type, "UNKNOWN"), |
517 |
binding.mac, binding.tap) |
518 |
|
519 |
if req_type == DHCPREQUEST and requested_addr != binding.ip: |
520 |
resp_type = DHCPNAK |
521 |
logging.info("Sending DHCPNAK to %s on %s: requested %s" |
522 |
" instead of %s", binding.mac, binding.tap, requested_addr, |
523 |
binding.ip) |
524 |
|
525 |
elif req_type in (DHCPDISCOVER, DHCPREQUEST): |
526 |
resp_type = DHCP_REQRESP[req_type] |
527 |
resp.yiaddr = self.clients[mac].ip |
528 |
dhcp_options += [ |
529 |
("hostname", binding.hostname), |
530 |
("domain", binding.hostname.split('.', 1)[-1]), |
531 |
("broadcast_address", str(subnet.broadcast)), |
532 |
("subnet_mask", str(subnet.netmask)), |
533 |
("renewal_time", self.lease_renewal), |
534 |
("lease_time", self.lease_lifetime), |
535 |
] |
536 |
if subnet.gw: |
537 |
dhcp_options += [("router", subnet.gw)] |
538 |
dhcp_options += [("name_server", x) for x in self.dhcp_nameservers] |
539 |
|
540 |
elif req_type == DHCPINFORM: |
541 |
resp_type = DHCP_REQRESP[req_type] |
542 |
dhcp_options += [ |
543 |
("hostname", binding.hostname), |
544 |
("domain", binding.hostname.split('.', 1)[-1]), |
545 |
] |
546 |
dhcp_options += [("name_server", x) for x in self.dhcp_nameservers] |
547 |
|
548 |
elif req_type == DHCPRELEASE: |
549 |
# Log and ignore |
550 |
logging.info("DHCPRELEASE from %s on %s", binding.mac, binding.tap ) |
551 |
return |
552 |
|
553 |
# Finally, always add the server identifier and end options |
554 |
dhcp_options += [ |
555 |
("message-type", resp_type), |
556 |
("server_id", DHCP_DUMMY_SERVER_IP), |
557 |
"end" |
558 |
] |
559 |
resp /= DHCP(options=dhcp_options) |
560 |
|
561 |
if payload.get_indev() != self.get_ifindex(binding.indev): |
562 |
logging.warn("Received spoofed DHCP request for %s from interface" |
563 |
" %s instead of %s", mac, payload.get_indev(), binding.indev) |
564 |
return |
565 |
|
566 |
logging.info("%s to %s (%s) on %s", DHCP_TYPES[resp_type], mac, |
567 |
binding.ip, binding.tap) |
568 |
self.sendp(resp, binding.indev) |
569 |
|
570 |
def rs_response(self, i, payload): # pylint: disable=W0613 |
571 |
""" Generate a reply to a BOOTP/DHCP request |
572 |
|
573 |
""" |
574 |
pkt = IPv6(payload.get_data()) |
575 |
mac = pkt.lladdr |
576 |
logging.debug("rs for mac %s", mac) |
577 |
try: |
578 |
binding = self.clients[mac] |
579 |
except KeyError: |
580 |
logging.debug("Ignoring router solicitation on" |
581 |
" for mac %s", mac) |
582 |
# We don't know what to do with this packet, so let the kernel |
583 |
# handle it |
584 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
585 |
return |
586 |
|
587 |
# Signal the kernel that it shouldn't further process the packet |
588 |
payload.set_verdict(nfqueue.NF_DROP) |
589 |
|
590 |
subnet = binding.net6 |
591 |
|
592 |
if subnet.net is None: |
593 |
logging.debug("No IPv6 network assigned for the interface") |
594 |
return |
595 |
|
596 |
ifmac = self.get_iface_hw_addr(binding.indev) |
597 |
ifll = subnet.make_ll64(ifmac) |
598 |
|
599 |
|
600 |
resp = Ether(src=ifmac)/\ |
601 |
IPv6(src=str(ifll))/ICMPv6ND_RA(routerlifetime=14400)/\ |
602 |
ICMPv6NDOptPrefixInfo(prefix=str(subnet.prefix), |
603 |
prefixlen=subnet.prefixlen) |
604 |
|
605 |
if self.ipv6_nameservers: |
606 |
resp /= ICMPv6NDOptRDNSS(dns=self.ipv6_nameservers, |
607 |
lifetime=self.ra_period * 3) |
608 |
|
609 |
logging.info("RA on %s for %s", binding.indev, subnet.net) |
610 |
self.sendp(resp, binding.indev) |
611 |
|
612 |
def ns_response(self, i, payload): # pylint: disable=W0613 |
613 |
""" Generate a reply to an ICMPv6 neighbor solicitation |
614 |
|
615 |
""" |
616 |
ns = IPv6(payload.get_data()) |
617 |
|
618 |
binding = None |
619 |
for b in self.clients.values(): |
620 |
if b.eui64 == ns.tgt: |
621 |
binding = b |
622 |
break |
623 |
|
624 |
if binding is None: |
625 |
logging.debug("Ignoring neighbour solicitation on" |
626 |
" for eui64 %s", ns.tgt) |
627 |
# We don't know what to do with this packet, so let the kernel |
628 |
# handle it |
629 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
630 |
return |
631 |
|
632 |
payload.set_verdict(nfqueue.NF_DROP) |
633 |
|
634 |
subnet = binding.net6 |
635 |
if subnet.net is None: |
636 |
logging.debug("No IPv6 network assigned for the interface") |
637 |
return |
638 |
|
639 |
indevmac = self.get_iface_hw_addr(binding.indev) |
640 |
|
641 |
ifll = subnet.make_ll64(indevmac) |
642 |
|
643 |
if not (subnet.net.overlaps(ns.tgt) or str(ns.tgt) == str(ifll)): |
644 |
logging.debug("Received NS for a non-routable IP (%s)", ns.tgt) |
645 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
646 |
return 1 |
647 |
|
648 |
logging.debug("na ether %s %s", binding.mac, ns.src) |
649 |
resp = Ether(src=indevmac, dst=binding.mac)/\ |
650 |
IPv6(src=str(ifll), dst=ns.src)/\ |
651 |
ICMPv6ND_NA(R=1, O=0, S=1, tgt=ns.tgt)/\ |
652 |
ICMPv6NDOptDstLLAddr(lladdr=indevmac) |
653 |
|
654 |
logging.info("NA on %s for %s", binding.indev, ns.tgt) |
655 |
self.sendp(resp, binding.indev) |
656 |
|
657 |
def send_periodic_ra(self): |
658 |
# Use a separate thread as this may take a _long_ time with |
659 |
# many interfaces and we want to be responsive in the mean time |
660 |
threading.Thread(target=self._send_periodic_ra).start() |
661 |
|
662 |
def _send_periodic_ra(self): |
663 |
logging.debug("Sending out periodic RAs") |
664 |
start = time.time() |
665 |
i = 0 |
666 |
for binding in self.clients.values(): |
667 |
tap = binding.tap |
668 |
indev = binding.indev |
669 |
mac = binding.mac |
670 |
subnet = binding.net6 |
671 |
if subnet.net is None: |
672 |
logging.debug("Skipping periodic RA on interface %s," |
673 |
" as it is not IPv6-connected", tap) |
674 |
continue |
675 |
indevmac = self.get_iface_hw_addr(indev) |
676 |
ifll = subnet.make_ll64(indevmac) |
677 |
resp = Ether(src=indevmac)/\ |
678 |
IPv6(src=str(ifll))/ICMPv6ND_RA(routerlifetime=14400)/\ |
679 |
ICMPv6NDOptPrefixInfo(prefix=str(subnet.prefix), |
680 |
prefixlen=subnet.prefixlen) |
681 |
if self.ipv6_nameservers: |
682 |
resp /= ICMPv6NDOptRDNSS(dns=self.ipv6_nameservers, |
683 |
lifetime=self.ra_period * 3) |
684 |
try: |
685 |
self.sendp(resp, indev) |
686 |
except socket.error, e: |
687 |
logging.warn("Periodic RA on %s failed: %s", tap, str(e)) |
688 |
except Exception, e: |
689 |
logging.warn("Unkown error during periodic RA on %s: %s", |
690 |
tap, str(e)) |
691 |
i += 1 |
692 |
logging.debug("Sent %d RAs in %.2f seconds", i, time.time() - start) |
693 |
|
694 |
def serve(self): |
695 |
""" Safely perform the main loop, freeing all resources upon exit |
696 |
|
697 |
""" |
698 |
try: |
699 |
self._serve() |
700 |
finally: |
701 |
self._cleanup() |
702 |
|
703 |
def _serve(self): |
704 |
""" Loop forever, serving DHCP requests |
705 |
|
706 |
""" |
707 |
self.build_config() |
708 |
|
709 |
# Yes, we are accessing _fd directly, but it's the only way to have a |
710 |
# single select() loop ;-) |
711 |
iwfd = self.notifier._fd # pylint: disable=W0212 |
712 |
|
713 |
start = time.time() |
714 |
if self.ipv6_enabled: |
715 |
timeout = self.ra_period |
716 |
self.send_periodic_ra() |
717 |
else: |
718 |
timeout = None |
719 |
|
720 |
while True: |
721 |
rlist, _, xlist = select(self.nfq.keys() + [iwfd], [], [], timeout) |
722 |
if xlist: |
723 |
logging.warn("Warning: Exception on %s", |
724 |
", ".join([ str(fd) for fd in xlist])) |
725 |
|
726 |
if rlist: |
727 |
if iwfd in rlist: |
728 |
# First check if there are any inotify (= configuration change) |
729 |
# events |
730 |
self.notifier.read_events() |
731 |
self.notifier.process_events() |
732 |
rlist.remove(iwfd) |
733 |
|
734 |
for fd in rlist: |
735 |
try: |
736 |
self.nfq[fd].process_pending() |
737 |
except RuntimeError, e: |
738 |
logging.warn("Error processing fd %d: %s", fd, str(e)) |
739 |
except Exception, e: |
740 |
logging.warn("Unknown error processing fd %d: %s", |
741 |
fd, str(e)) |
742 |
|
743 |
if self.ipv6_enabled: |
744 |
# Calculate the new timeout |
745 |
timeout = self.ra_period - (time.time() - start) |
746 |
|
747 |
if timeout <= 0: |
748 |
start = time.time() |
749 |
self.send_periodic_ra() |
750 |
timeout = self.ra_period - (time.time() - start) |
751 |
|
752 |
|
753 |
if __name__ == "__main__": |
754 |
import capng |
755 |
import optparse |
756 |
from cStringIO import StringIO |
757 |
from pwd import getpwnam, getpwuid |
758 |
from configobj import ConfigObj, ConfigObjError, flatten_errors |
759 |
|
760 |
import validate |
761 |
|
762 |
validator = validate.Validator() |
763 |
|
764 |
def is_ip_list(value, family=4): |
765 |
try: |
766 |
family = int(family) |
767 |
except ValueError: |
768 |
raise validate.VdtParamError(family) |
769 |
if isinstance(value, (str, unicode)): |
770 |
value = [value] |
771 |
if not isinstance(value, list): |
772 |
raise validate.VdtTypeError(value) |
773 |
|
774 |
for entry in value: |
775 |
try: |
776 |
ip = IPy.IP(entry) |
777 |
except ValueError: |
778 |
raise validate.VdtValueError(entry) |
779 |
|
780 |
if ip.version() != family: |
781 |
raise validate.VdtValueError(entry) |
782 |
return value |
783 |
|
784 |
validator.functions["ip_addr_list"] = is_ip_list |
785 |
config_spec = StringIO(CONFIG_SPEC) |
786 |
|
787 |
|
788 |
parser = optparse.OptionParser() |
789 |
parser.add_option("-c", "--config", dest="config_file", |
790 |
help="The location of the data files", metavar="FILE", |
791 |
default=DEFAULT_CONFIG) |
792 |
parser.add_option("-d", "--debug", action="store_true", dest="debug", |
793 |
help="Turn on debugging messages") |
794 |
parser.add_option("-f", "--foreground", action="store_false", |
795 |
dest="daemonize", default=True, |
796 |
help="Do not daemonize, stay in the foreground") |
797 |
|
798 |
|
799 |
opts, args = parser.parse_args() |
800 |
|
801 |
try: |
802 |
config = ConfigObj(opts.config_file, configspec=config_spec) |
803 |
except ConfigObjError, err: |
804 |
sys.stderr.write("Failed to parse config file %s: %s" % |
805 |
(opts.config_file, str(err))) |
806 |
sys.exit(1) |
807 |
|
808 |
results = config.validate(validator) |
809 |
if results != True: |
810 |
logging.fatal("Configuration file validation failed! See errors below:") |
811 |
for (section_list, key, unused) in flatten_errors(config, results): |
812 |
if key is not None: |
813 |
logging.fatal(" '%s' in section '%s' failed validation", |
814 |
key, ", ".join(section_list)) |
815 |
else: |
816 |
logging.fatal(" Section '%s' is missing", |
817 |
", ".join(section_list)) |
818 |
sys.exit(1) |
819 |
|
820 |
logger = logging.getLogger() |
821 |
if opts.debug: |
822 |
logger.setLevel(logging.DEBUG) |
823 |
else: |
824 |
logger.setLevel(logging.INFO) |
825 |
|
826 |
if opts.daemonize: |
827 |
logfile = os.path.join(config["general"]["logdir"], LOG_FILENAME) |
828 |
handler = logging.handlers.RotatingFileHandler(logfile, |
829 |
maxBytes=2097152) |
830 |
else: |
831 |
handler = logging.StreamHandler() |
832 |
|
833 |
handler.setFormatter(logging.Formatter(LOG_FORMAT)) |
834 |
logger.addHandler(handler) |
835 |
|
836 |
if opts.daemonize: |
837 |
pidfile = daemon.pidlockfile.TimeoutPIDLockFile( |
838 |
config["general"]["pidfile"], 10) |
839 |
|
840 |
d = daemon.DaemonContext(pidfile=pidfile, |
841 |
stdout=handler.stream, |
842 |
stderr=handler.stream, |
843 |
files_preserve=[handler.stream]) |
844 |
d.umask = 0022 |
845 |
d.open() |
846 |
|
847 |
logging.info("Starting up") |
848 |
|
849 |
proxy_opts = {} |
850 |
if config["dhcp"].as_bool("enable_dhcp"): |
851 |
proxy_opts.update({ |
852 |
"dhcp_queue_num": config["dhcp"].as_int("dhcp_queue"), |
853 |
"dhcp_lease_lifetime": config["dhcp"].as_int("lease_lifetime"), |
854 |
"dhcp_lease_renewal": config["dhcp"].as_int("lease_renewal"), |
855 |
"dhcp_server_ip": config["dhcp"]["server_ip"], |
856 |
"dhcp_nameservers": config["dhcp"]["nameservers"], |
857 |
}) |
858 |
|
859 |
if config["ipv6"].as_bool("enable_ipv6"): |
860 |
proxy_opts.update({ |
861 |
"rs_queue_num": config["ipv6"].as_int("rs_queue"), |
862 |
"ns_queue_num": config["ipv6"].as_int("ns_queue"), |
863 |
"ra_period": config["ipv6"].as_int("ra_period"), |
864 |
"ipv6_nameservers": config["ipv6"]["nameservers"], |
865 |
}) |
866 |
|
867 |
# pylint: disable=W0142 |
868 |
proxy = VMNetProxy(data_path=config["general"]["datapath"], **proxy_opts) |
869 |
|
870 |
# Drop all capabilities except CAP_NET_RAW and change uid |
871 |
try: |
872 |
uid = getpwuid(config["general"].as_int("user")) |
873 |
except ValueError: |
874 |
uid = getpwnam(config["general"]["user"]) |
875 |
|
876 |
logging.debug("Setting capabilities and changing uid") |
877 |
logging.debug("User: %s, uid: %d, gid: %d", |
878 |
config["general"]["user"], uid.pw_uid, uid.pw_gid) |
879 |
|
880 |
# Keep only the capabilities we need |
881 |
# CAP_NET_ADMIN: we need to send nfqueue packet verdicts to a netlinkgroup |
882 |
capng.capng_clear(capng.CAPNG_SELECT_BOTH) |
883 |
capng.capng_update(capng.CAPNG_ADD, |
884 |
capng.CAPNG_EFFECTIVE|capng.CAPNG_PERMITTED, |
885 |
capng.CAP_NET_ADMIN) |
886 |
capng.capng_change_id(uid.pw_uid, uid.pw_gid, |
887 |
capng.CAPNG_DROP_SUPP_GRP|capng.CAPNG_CLEAR_BOUNDING) |
888 |
|
889 |
logging.info("Ready to serve requests") |
890 |
try: |
891 |
proxy.serve() |
892 |
except Exception: |
893 |
if opts.daemonize: |
894 |
exc = "".join(traceback.format_exception(*sys.exc_info())) |
895 |
logging.critical(exc) |
896 |
raise |
897 |
|
898 |
|
899 |
# vim: set ts=4 sts=4 sw=4 et : |