root / nfdhcpd @ d7b852fd
History | View | Annotate | Download (33.5 kB)
1 |
#!/usr/bin/env python |
---|---|
2 |
# |
3 |
|
4 |
# nfdcpd: A promiscuous, NFQUEUE-based DHCP server for virtual machine hosting |
5 |
# Copyright (c) 2010 GRNET SA |
6 |
# |
7 |
# This program is free software; you can redistribute it and/or modify |
8 |
# it under the terms of the GNU General Public License as published by |
9 |
# the Free Software Foundation; either version 2 of the License, or |
10 |
# (at your option) any later version. |
11 |
# |
12 |
# This program is distributed in the hope that it will be useful, |
13 |
# but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 |
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
15 |
# GNU General Public License for more details. |
16 |
# |
17 |
# You should have received a copy of the GNU General Public License along |
18 |
# with this program; if not, write to the Free Software Foundation, Inc., |
19 |
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
20 |
# |
21 |
|
22 |
import os |
23 |
import re |
24 |
import sys |
25 |
import glob |
26 |
import time |
27 |
import logging |
28 |
import logging.handlers |
29 |
import threading |
30 |
import traceback |
31 |
import subprocess |
32 |
|
33 |
import daemon |
34 |
import daemon.runner |
35 |
import daemon.pidlockfile |
36 |
import nfqueue |
37 |
import pyinotify |
38 |
from lockfile import LockTimeout |
39 |
|
40 |
import IPy |
41 |
import socket |
42 |
from select import select |
43 |
from socket import AF_INET, AF_INET6 |
44 |
|
45 |
from scapy.data import ETH_P_ALL |
46 |
from scapy.packet import BasePacket |
47 |
from scapy.layers.l2 import Ether |
48 |
from scapy.layers.inet import IP, UDP |
49 |
from scapy.layers.inet6 import IPv6, ICMPv6ND_RA, ICMPv6ND_NA, \ |
50 |
ICMPv6NDOptDstLLAddr, \ |
51 |
ICMPv6NDOptPrefixInfo, \ |
52 |
ICMPv6NDOptRDNSS |
53 |
from scapy.layers.dhcp import BOOTP, DHCP |
54 |
|
55 |
DEFAULT_CONFIG = "/etc/nfdhcpd/nfdhcpd.conf" |
56 |
DEFAULT_PATH = "/var/run/ganeti-dhcpd" |
57 |
DEFAULT_USER = "nobody" |
58 |
DEFAULT_LEASE_LIFETIME = 604800 # 1 week |
59 |
DEFAULT_LEASE_RENEWAL = 600 # 10 min |
60 |
DEFAULT_RA_PERIOD = 300 # seconds |
61 |
DHCP_DUMMY_SERVER_IP = "1.2.3.4" |
62 |
|
63 |
LOG_FILENAME = "nfdhcpd.log" |
64 |
|
65 |
SYSFS_NET = "/sys/class/net" |
66 |
|
67 |
LOG_FORMAT = "%(asctime)-15s %(levelname)-6s %(message)s" |
68 |
|
69 |
# Configuration file specification (see configobj documentation) |
70 |
CONFIG_SPEC = """ |
71 |
[general] |
72 |
pidfile = string() |
73 |
datapath = string() |
74 |
logdir = string() |
75 |
user = string() |
76 |
|
77 |
[dhcp] |
78 |
enable_dhcp = boolean(default=True) |
79 |
lease_lifetime = integer(min=0, max=4294967295) |
80 |
lease_renewal = integer(min=0, max=4294967295) |
81 |
server_ip = ip_addr() |
82 |
dhcp_queue = integer(min=0, max=65535) |
83 |
nameservers = ip_addr_list(family=4) |
84 |
domain = string(default=None) |
85 |
|
86 |
[ipv6] |
87 |
enable_ipv6 = boolean(default=True) |
88 |
ra_period = integer(min=1, max=4294967295) |
89 |
rs_queue = integer(min=0, max=65535) |
90 |
ns_queue = integer(min=0, max=65535) |
91 |
nameservers = ip_addr_list(family=6) |
92 |
""" |
93 |
|
94 |
|
95 |
DHCPDISCOVER = 1 |
96 |
DHCPOFFER = 2 |
97 |
DHCPREQUEST = 3 |
98 |
DHCPDECLINE = 4 |
99 |
DHCPACK = 5 |
100 |
DHCPNAK = 6 |
101 |
DHCPRELEASE = 7 |
102 |
DHCPINFORM = 8 |
103 |
|
104 |
DHCP_TYPES = { |
105 |
DHCPDISCOVER: "DHCPDISCOVER", |
106 |
DHCPOFFER: "DHCPOFFER", |
107 |
DHCPREQUEST: "DHCPREQUEST", |
108 |
DHCPDECLINE: "DHCPDECLINE", |
109 |
DHCPACK: "DHCPACK", |
110 |
DHCPNAK: "DHCPNAK", |
111 |
DHCPRELEASE: "DHCPRELEASE", |
112 |
DHCPINFORM: "DHCPINFORM", |
113 |
} |
114 |
|
115 |
DHCP_REQRESP = { |
116 |
DHCPDISCOVER: DHCPOFFER, |
117 |
DHCPREQUEST: DHCPACK, |
118 |
DHCPINFORM: DHCPACK, |
119 |
} |
120 |
|
121 |
|
122 |
def get_indev(payload): |
123 |
try: |
124 |
indev_ifindex = payload.get_physindev() |
125 |
logging.debug("get_physindev %s", indev_ifindex) |
126 |
if indev_ifindex: |
127 |
logging.debug("Incomming packet from bridge %s", indev_ifindex) |
128 |
return indev_ifindex |
129 |
except AttributeError: |
130 |
#TODO: return error value |
131 |
logging.debug("No get_physindev supported") |
132 |
return 0 |
133 |
|
134 |
indev_ifindex = payload.get_indev() |
135 |
logging.debug("Incomming packet from tap %s", indev_ifindex) |
136 |
|
137 |
return indev_ifindex |
138 |
|
139 |
def get_binding(proxy, ifindex, mac): |
140 |
try: |
141 |
if proxy.mac_indexed_clients: |
142 |
logging.debug("get_binding for mac %s", mac) |
143 |
b = proxy.clients[mac] |
144 |
else: |
145 |
logging.debug("get_binding for ifindex %s", ifindex) |
146 |
b = proxy.clients[ifindex] |
147 |
return b |
148 |
except KeyError: |
149 |
logging.debug("No client found for mac/ifindex %s/%s", mac, ifindex) |
150 |
return None |
151 |
|
152 |
def parse_binding_file(path): |
153 |
""" Read a client configuration from a tap file |
154 |
|
155 |
""" |
156 |
try: |
157 |
iffile = open(path, 'r') |
158 |
except EnvironmentError, e: |
159 |
logging.warn("Unable to open binding file %s: %s", path, str(e)) |
160 |
return None |
161 |
|
162 |
tap = os.path.basename(path) |
163 |
indev = None |
164 |
mac = None |
165 |
ip = None |
166 |
hostname = None |
167 |
subnet = None |
168 |
gateway = None |
169 |
subnet6 = None |
170 |
gateway6 = None |
171 |
eui64 = None |
172 |
|
173 |
def get_value(line): |
174 |
v = line.strip().split('=')[1] |
175 |
if v == '': |
176 |
return None |
177 |
return v |
178 |
|
179 |
for line in iffile: |
180 |
if line.startswith("IP="): |
181 |
ip = get_value(line) |
182 |
elif line.startswith("MAC="): |
183 |
mac = get_value(line) |
184 |
elif line.startswith("HOSTNAME="): |
185 |
hostname = get_value(line) |
186 |
elif line.startswith("INDEV="): |
187 |
indev = get_value(line) |
188 |
elif line.startswith("SUBNET="): |
189 |
subnet = get_value(line) |
190 |
elif line.startswith("GATEWAY="): |
191 |
gateway = get_value(line) |
192 |
elif line.startswith("SUBNET6="): |
193 |
subnet6 = get_value(line) |
194 |
elif line.startswith("GATEWAY6="): |
195 |
gateway6 = get_value(line) |
196 |
elif line.startswith("EUI64="): |
197 |
eui64 = get_value(line) |
198 |
|
199 |
try: |
200 |
client = Client(tap=tap, mac=mac, ip=ip, |
201 |
hostname=hostname, indev=indev, subnet=subnet, |
202 |
gateway=gateway, subnet6=subnet6, gateway6=gateway6, eui64=eui64 ) |
203 |
return client |
204 |
except: |
205 |
return None |
206 |
|
207 |
class ClientFileHandler(pyinotify.ProcessEvent): |
208 |
def __init__(self, server): |
209 |
pyinotify.ProcessEvent.__init__(self) |
210 |
self.server = server |
211 |
|
212 |
def process_IN_DELETE(self, event): # pylint: disable=C0103 |
213 |
""" Delete file handler |
214 |
|
215 |
Currently this removes an interface from the watch list |
216 |
|
217 |
""" |
218 |
self.server.remove_tap(event.name) |
219 |
|
220 |
def process_IN_CLOSE_WRITE(self, event): # pylint: disable=C0103 |
221 |
""" Add file handler |
222 |
|
223 |
Currently this adds an interface to the watch list |
224 |
|
225 |
""" |
226 |
self.server.add_tap(os.path.join(event.path, event.name)) |
227 |
|
228 |
|
229 |
class Client(object): |
230 |
def __init__(self, tap=None, indev=None, mac=None, ip=None, hostname=None, |
231 |
subnet=None, gateway=None, subnet6=None, gateway6=None, eui64=None ): |
232 |
self.mac = mac |
233 |
self.ip = ip |
234 |
self.hostname = hostname |
235 |
self.indev = indev |
236 |
self.tap = tap |
237 |
self.subnet = subnet |
238 |
self.gateway = gateway |
239 |
self.net = Subnet(net=subnet, gw=gateway, dev=tap) |
240 |
self.subnet6 = subnet6 |
241 |
self.gateway6 = gateway6 |
242 |
self.net6 = Subnet(net=subnet6, gw=gateway6, dev=tap) |
243 |
self.eui64 = eui64 |
244 |
|
245 |
def is_valid(self): |
246 |
return self.mac is not None and self.ip is not None\ |
247 |
and self.hostname is not None |
248 |
|
249 |
|
250 |
class Subnet(object): |
251 |
def __init__(self, net=None, gw=None, dev=None): |
252 |
if isinstance(net, str): |
253 |
try: |
254 |
self.net = IPy.IP(net) |
255 |
except: |
256 |
raise Exception |
257 |
else: |
258 |
self.net = net |
259 |
self.gw = gw |
260 |
self.dev = dev |
261 |
|
262 |
@property |
263 |
def netmask(self): |
264 |
""" Return the netmask in textual representation |
265 |
|
266 |
""" |
267 |
return str(self.net.netmask()) |
268 |
|
269 |
@property |
270 |
def broadcast(self): |
271 |
""" Return the broadcast address in textual representation |
272 |
|
273 |
""" |
274 |
return str(self.net.broadcast()) |
275 |
|
276 |
@property |
277 |
def prefix(self): |
278 |
""" Return the network as an IPy.IP |
279 |
|
280 |
""" |
281 |
return self.net.net() |
282 |
|
283 |
@property |
284 |
def prefixlen(self): |
285 |
""" Return the prefix length as an integer |
286 |
|
287 |
""" |
288 |
return self.net.prefixlen() |
289 |
|
290 |
@staticmethod |
291 |
def _make_eui64(net, mac): |
292 |
""" Compute an EUI-64 address from an EUI-48 (MAC) address |
293 |
|
294 |
""" |
295 |
if mac is None: |
296 |
return None |
297 |
comp = mac.split(":") |
298 |
prefix = IPy.IP(net).net().strFullsize().split(":")[:4] |
299 |
eui64 = comp[:3] + ["ff", "fe"] + comp[3:] |
300 |
eui64[0] = "%02x" % (int(eui64[0], 16) ^ 0x02) |
301 |
for l in range(0, len(eui64), 2): |
302 |
prefix += ["".join(eui64[l:l+2])] |
303 |
return IPy.IP(":".join(prefix)) |
304 |
|
305 |
def make_eui64(self, mac): |
306 |
""" Compute an EUI-64 address from an EUI-48 (MAC) address in this |
307 |
subnet. |
308 |
|
309 |
""" |
310 |
return self._make_eui64(self.net, mac) |
311 |
|
312 |
def make_ll64(self, mac): |
313 |
""" Compute an IPv6 Link-local address from an EUI-48 (MAC) address |
314 |
|
315 |
""" |
316 |
return self._make_eui64("fe80::", mac) |
317 |
|
318 |
|
319 |
class VMNetProxy(object): # pylint: disable=R0902 |
320 |
def __init__(self, data_path, dhcp_queue_num=None, # pylint: disable=R0913 |
321 |
rs_queue_num=None, ns_queue_num=None, |
322 |
dhcp_lease_lifetime=DEFAULT_LEASE_LIFETIME, |
323 |
dhcp_lease_renewal=DEFAULT_LEASE_RENEWAL, |
324 |
dhcp_domain='', |
325 |
dhcp_server_ip=DHCP_DUMMY_SERVER_IP, dhcp_nameservers=None, |
326 |
ra_period=DEFAULT_RA_PERIOD, ipv6_nameservers=None): |
327 |
|
328 |
try: |
329 |
getattr(nfqueue.payload, 'get_physindev') |
330 |
self.mac_indexed_clients = False |
331 |
except AttributeError: |
332 |
self.mac_indexed_clients = True |
333 |
self.data_path = data_path |
334 |
self.lease_lifetime = dhcp_lease_lifetime |
335 |
self.lease_renewal = dhcp_lease_renewal |
336 |
self.dhcp_domain = dhcp_domain |
337 |
self.dhcp_server_ip = dhcp_server_ip |
338 |
self.ra_period = ra_period |
339 |
if dhcp_nameservers is None: |
340 |
self.dhcp_nameserver = [] |
341 |
else: |
342 |
self.dhcp_nameservers = dhcp_nameservers |
343 |
|
344 |
if ipv6_nameservers is None: |
345 |
self.ipv6_nameservers = [] |
346 |
else: |
347 |
self.ipv6_nameservers = ipv6_nameservers |
348 |
|
349 |
self.ipv6_enabled = False |
350 |
|
351 |
self.clients = {} |
352 |
#self.subnets = {} |
353 |
#self.ifaces = {} |
354 |
#self.v6nets = {} |
355 |
self.nfq = {} |
356 |
self.l2socket = socket.socket(socket.AF_PACKET, |
357 |
socket.SOCK_RAW, ETH_P_ALL) |
358 |
self.l2socket.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 0) |
359 |
|
360 |
# Inotify setup |
361 |
self.wm = pyinotify.WatchManager() |
362 |
mask = pyinotify.EventsCodes.ALL_FLAGS["IN_DELETE"] |
363 |
mask |= pyinotify.EventsCodes.ALL_FLAGS["IN_CLOSE_WRITE"] |
364 |
inotify_handler = ClientFileHandler(self) |
365 |
self.notifier = pyinotify.Notifier(self.wm, inotify_handler) |
366 |
self.wm.add_watch(self.data_path, mask, rec=True) |
367 |
|
368 |
# NFQUEUE setup |
369 |
if dhcp_queue_num is not None: |
370 |
self._setup_nfqueue(dhcp_queue_num, AF_INET, self.dhcp_response) |
371 |
|
372 |
if rs_queue_num is not None: |
373 |
self._setup_nfqueue(rs_queue_num, AF_INET6, self.rs_response) |
374 |
self.ipv6_enabled = True |
375 |
|
376 |
if ns_queue_num is not None: |
377 |
self._setup_nfqueue(ns_queue_num, AF_INET6, self.ns_response) |
378 |
self.ipv6_enabled = True |
379 |
|
380 |
def _cleanup(self): |
381 |
""" Free all resources for a graceful exit |
382 |
|
383 |
""" |
384 |
logging.info("Cleaning up") |
385 |
|
386 |
logging.debug("Closing netfilter queues") |
387 |
for q in self.nfq.values(): |
388 |
q.close() |
389 |
|
390 |
logging.debug("Closing socket") |
391 |
self.l2socket.close() |
392 |
|
393 |
logging.debug("Stopping inotify watches") |
394 |
self.notifier.stop() |
395 |
|
396 |
logging.info("Cleanup finished") |
397 |
|
398 |
def _setup_nfqueue(self, queue_num, family, callback): |
399 |
logging.debug("Setting up NFQUEUE for queue %d, AF %s", |
400 |
queue_num, family) |
401 |
q = nfqueue.queue() |
402 |
q.set_callback(callback) |
403 |
q.fast_open(queue_num, family) |
404 |
q.set_queue_maxlen(5000) |
405 |
# This is mandatory for the queue to operate |
406 |
q.set_mode(nfqueue.NFQNL_COPY_PACKET) |
407 |
self.nfq[q.get_fd()] = q |
408 |
|
409 |
def sendp(self, data, dev): |
410 |
""" Send a raw packet using a layer-2 socket |
411 |
|
412 |
""" |
413 |
logging.debug("%s", data) |
414 |
if isinstance(data, BasePacket): |
415 |
data = str(data) |
416 |
|
417 |
self.l2socket.bind((dev, ETH_P_ALL)) |
418 |
count = self.l2socket.send(data) |
419 |
ldata = len(data) |
420 |
if count != ldata: |
421 |
logging.warn("Truncated send on %s (%d/%d bytes sent)", |
422 |
dev, count, ldata) |
423 |
|
424 |
def build_config(self): |
425 |
self.clients.clear() |
426 |
|
427 |
for path in glob.glob(os.path.join(self.data_path, "*")): |
428 |
self.add_tap(path) |
429 |
|
430 |
logging.debug("\n\n\n\n\n") |
431 |
logging.debug("%10s %20s %7s %15s", 'Client', 'MAC', 'TAP', 'IP') |
432 |
for b in self.clients.values(): |
433 |
logging.debug("%10s %20s %7s %15s", b.hostname, b.mac, b.tap, b.ip) |
434 |
|
435 |
def get_ifindex(self, iface): |
436 |
""" Get the interface index from sysfs |
437 |
|
438 |
""" |
439 |
path = os.path.abspath(os.path.join(SYSFS_NET, iface, "ifindex")) |
440 |
if not path.startswith(SYSFS_NET): |
441 |
return None |
442 |
|
443 |
ifindex = None |
444 |
|
445 |
try: |
446 |
f = open(path, 'r') |
447 |
except EnvironmentError: |
448 |
logging.debug("%s is probably down, removing", iface) |
449 |
self.remove_tap(iface) |
450 |
|
451 |
return ifindex |
452 |
|
453 |
try: |
454 |
ifindex = f.readline().strip() |
455 |
try: |
456 |
ifindex = int(ifindex) |
457 |
except ValueError, e: |
458 |
logging.warn("Failed to get ifindex for %s, cannot parse sysfs" |
459 |
" output '%s'", iface, ifindex) |
460 |
except EnvironmentError, e: |
461 |
logging.warn("Error reading %s's ifindex from sysfs: %s", |
462 |
iface, str(e)) |
463 |
self.remove_tap(iface) |
464 |
finally: |
465 |
f.close() |
466 |
|
467 |
return ifindex |
468 |
|
469 |
|
470 |
def get_iface_hw_addr(self, iface): |
471 |
""" Get the interface hardware address from sysfs |
472 |
|
473 |
""" |
474 |
path = os.path.abspath(os.path.join(SYSFS_NET, iface, "address")) |
475 |
if not path.startswith(SYSFS_NET): |
476 |
return None |
477 |
|
478 |
addr = None |
479 |
try: |
480 |
f = open(path, 'r') |
481 |
except EnvironmentError: |
482 |
logging.debug("%s is probably down, removing", iface) |
483 |
self.remove_tap(iface) |
484 |
return addr |
485 |
|
486 |
try: |
487 |
addr = f.readline().strip() |
488 |
except EnvironmentError, e: |
489 |
logging.warn("Failed to read hw address for %s from sysfs: %s", |
490 |
iface, str(e)) |
491 |
finally: |
492 |
f.close() |
493 |
|
494 |
return addr |
495 |
|
496 |
def add_tap(self, path): |
497 |
""" Add an interface to monitor |
498 |
|
499 |
""" |
500 |
tap = os.path.basename(path) |
501 |
|
502 |
logging.debug("Updating configuration for %s", tap) |
503 |
b = parse_binding_file(path) |
504 |
if b is None: |
505 |
return |
506 |
ifindex = self.get_ifindex(b.tap) |
507 |
|
508 |
if ifindex is None: |
509 |
logging.warn("Stale configuration for %s found", tap) |
510 |
else: |
511 |
if b.is_valid(): |
512 |
if self.mac_indexed_clients: |
513 |
self.clients[b.mac] = b |
514 |
else: |
515 |
self.clients[ifindex] = b |
516 |
logging.debug("Added client:") |
517 |
logging.debug("%5s: %10s %20s %7s %15s", |
518 |
ifindex, b.hostname, b.mac, b.tap, b.ip) |
519 |
|
520 |
def remove_tap(self, tap): |
521 |
""" Cleanup clients on a removed interface |
522 |
|
523 |
""" |
524 |
try: |
525 |
for k in self.clients.keys(): |
526 |
b = self.clients[k] |
527 |
if self.clients[k].tap == tap: |
528 |
logging.debug("Removing client on interface %s", tap) |
529 |
logging.debug("%10s %20s %7s %15s", |
530 |
b.hostname, b.mac, b.tap, b.ip) |
531 |
del self.clients[k] |
532 |
except: |
533 |
logging.debug("Client on %s disappeared!!!", tap) |
534 |
|
535 |
|
536 |
def dhcp_response(self, i, payload): # pylint: disable=W0613,R0914 |
537 |
""" Generate a reply to bnetfilter-queue-deva BOOTP/DHCP request |
538 |
|
539 |
""" |
540 |
# Decode the response - NFQUEUE relays IP packets |
541 |
pkt = IP(payload.get_data()) |
542 |
logging.debug("IN DHCP RESPONCE") |
543 |
#logging.debug(pkt.show()) |
544 |
|
545 |
# Get the client MAC address |
546 |
resp = pkt.getlayer(BOOTP).copy() |
547 |
hlen = resp.hlen |
548 |
mac = resp.chaddr[:hlen].encode("hex") |
549 |
mac, _ = re.subn(r'([0-9a-fA-F]{2})', r'\1:', mac, hlen-1) |
550 |
|
551 |
# Server responses are always BOOTREPLYs |
552 |
resp.op = "BOOTREPLY" |
553 |
del resp.payload |
554 |
|
555 |
indev = get_indev(payload) |
556 |
|
557 |
binding = get_binding(self, indev, mac) |
558 |
if binding is None: |
559 |
# We don't know anything about this interface, so accept the packet |
560 |
# and return |
561 |
logging.debug("Ignoring DHCP request on unknown iface %d", indev) |
562 |
# We don't know what to do with this packet, so let the kernel |
563 |
# handle it |
564 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
565 |
return |
566 |
|
567 |
|
568 |
# Signal the kernel that it shouldn't further process the packet |
569 |
payload.set_verdict(nfqueue.NF_DROP) |
570 |
|
571 |
if mac != binding.mac: |
572 |
logging.warn("Recieved spoofed DHCP request for mac %s from tap %s", mac, indev) |
573 |
return |
574 |
|
575 |
resp = Ether(dst=mac, src=self.get_iface_hw_addr(binding.indev))/\ |
576 |
IP(src=DHCP_DUMMY_SERVER_IP, dst=binding.ip)/\ |
577 |
UDP(sport=pkt.dport, dport=pkt.sport)/resp |
578 |
subnet = binding.net |
579 |
|
580 |
if not DHCP in pkt: |
581 |
logging.warn("Invalid request from %s on %s, no DHCP" |
582 |
" payload found", binding.mac, binding.tap) |
583 |
return |
584 |
|
585 |
dhcp_options = [] |
586 |
requested_addr = binding.ip |
587 |
for opt in pkt[DHCP].options: |
588 |
if type(opt) is tuple and opt[0] == "message-type": |
589 |
req_type = opt[1] |
590 |
if type(opt) is tuple and opt[0] == "requested_addr": |
591 |
requested_addr = opt[1] |
592 |
|
593 |
logging.info("%s from %s on %s", DHCP_TYPES.get(req_type, "UNKNOWN"), |
594 |
binding.mac, binding.tap) |
595 |
|
596 |
if self.dhcp_domain: |
597 |
domainname = self.dhcp_domain |
598 |
else: |
599 |
domainname = binding.hostname.split('.', 1)[-1] |
600 |
|
601 |
if req_type == DHCPREQUEST and requested_addr != binding.ip: |
602 |
resp_type = DHCPNAK |
603 |
logging.info("Sending DHCPNAK to %s on %s: requested %s" |
604 |
" instead of %s", binding.mac, binding.tap, |
605 |
requested_addr, binding.ip) |
606 |
|
607 |
elif req_type in (DHCPDISCOVER, DHCPREQUEST): |
608 |
resp_type = DHCP_REQRESP[req_type] |
609 |
resp.yiaddr = binding.ip |
610 |
dhcp_options += [ |
611 |
("hostname", binding.hostname), |
612 |
("domain", domainname), |
613 |
("broadcast_address", str(subnet.broadcast)), |
614 |
("subnet_mask", str(subnet.netmask)), |
615 |
("renewal_time", self.lease_renewal), |
616 |
("lease_time", self.lease_lifetime), |
617 |
] |
618 |
if subnet.gw: |
619 |
dhcp_options += [("router", subnet.gw)] |
620 |
dhcp_options += [("name_server", x) for x in self.dhcp_nameservers] |
621 |
|
622 |
elif req_type == DHCPINFORM: |
623 |
resp_type = DHCP_REQRESP[req_type] |
624 |
dhcp_options += [ |
625 |
("hostname", binding.hostname), |
626 |
("domain", domainname), |
627 |
] |
628 |
dhcp_options += [("name_server", x) for x in self.dhcp_nameservers] |
629 |
|
630 |
elif req_type == DHCPRELEASE: |
631 |
# Log and ignore |
632 |
logging.info("DHCPRELEASE from %s on %s", binding.mac, binding.tap ) |
633 |
return |
634 |
|
635 |
# Finally, always add the server identifier and end options |
636 |
dhcp_options += [ |
637 |
("message-type", resp_type), |
638 |
("server_id", DHCP_DUMMY_SERVER_IP), |
639 |
"end" |
640 |
] |
641 |
resp /= DHCP(options=dhcp_options) |
642 |
|
643 |
logging.info("%s to %s (%s) on %s", DHCP_TYPES[resp_type], mac, |
644 |
binding.ip, binding.tap) |
645 |
try: |
646 |
self.sendp(resp, binding.indev) |
647 |
except socket.error, e: |
648 |
logging.warn("DHCP response on %s failed: %s", binding.indev, str(e)) |
649 |
except Exception, e: |
650 |
logging.warn("Unkown error during DHCP response on %s: %s", |
651 |
binding.indev, str(e)) |
652 |
|
653 |
def rs_response(self, i, payload): # pylint: disable=W0613 |
654 |
""" Generate a reply to a BOOTP/DHCP request |
655 |
|
656 |
""" |
657 |
pkt = IPv6(payload.get_data()) |
658 |
logging.debug("IN RS RESPONCE") |
659 |
#logging.debug(pkt.show()) |
660 |
try: |
661 |
mac = pkt.lladdr |
662 |
except: |
663 |
logging.debug("Cannot obtain lladdr in rs") |
664 |
return |
665 |
|
666 |
logging.debug("rs for mac %s", mac) |
667 |
|
668 |
indev = get_indev(payload) |
669 |
|
670 |
binding = get_binding(self, indev, mac) |
671 |
if binding is None: |
672 |
# We don't know anything about this interface, so accept the packet |
673 |
# and return |
674 |
logging.debug("Ignoring router solicitation on for mac %s", mac) |
675 |
# We don't know what to do with this packet, so let the kernel |
676 |
# handle it |
677 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
678 |
return |
679 |
|
680 |
# Signal the kernel that it shouldn't further process the packet |
681 |
payload.set_verdict(nfqueue.NF_DROP) |
682 |
|
683 |
if mac != binding.mac: |
684 |
logging.warn("Recieved spoofed RS request for mac %s from tap %s", mac, tap) |
685 |
return |
686 |
|
687 |
subnet = binding.net6 |
688 |
|
689 |
if subnet.net is None: |
690 |
logging.debug("No IPv6 network assigned for the interface") |
691 |
return |
692 |
|
693 |
indevmac = self.get_iface_hw_addr(binding.indev) |
694 |
ifll = subnet.make_ll64(indevmac) |
695 |
if ifll is None: |
696 |
return |
697 |
|
698 |
|
699 |
resp = Ether(src=indevmac)/\ |
700 |
IPv6(src=str(ifll))/ICMPv6ND_RA(routerlifetime=14400)/\ |
701 |
ICMPv6NDOptPrefixInfo(prefix=str(subnet.prefix), |
702 |
prefixlen=subnet.prefixlen) |
703 |
|
704 |
if self.ipv6_nameservers: |
705 |
resp /= ICMPv6NDOptRDNSS(dns=self.ipv6_nameservers, |
706 |
lifetime=self.ra_period * 3) |
707 |
|
708 |
logging.info("RA on %s for %s", binding.indev, subnet.net) |
709 |
try: |
710 |
self.sendp(resp, binding.indev) |
711 |
except socket.error, e: |
712 |
logging.warn("RA on %s failed: %s", binding.indev, str(e)) |
713 |
except Exception, e: |
714 |
logging.warn("Unkown error during RA on %s: %s", |
715 |
binding.indev, str(e)) |
716 |
|
717 |
def ns_response(self, i, payload): # pylint: disable=W0613 |
718 |
""" Generate a reply to an ICMPv6 neighbor solicitation |
719 |
|
720 |
""" |
721 |
ns = IPv6(payload.get_data()) |
722 |
logging.debug("IN NS RESPONCE") |
723 |
#logging.debug(ns.show()) |
724 |
try: |
725 |
mac = ns.lladdr |
726 |
except: |
727 |
logging.debug("Cannot obtain lladdr from ns") |
728 |
return |
729 |
|
730 |
logging.debug("dst %s tgt %s" , ns.dst, ns.tgt) |
731 |
|
732 |
indev = get_indev(payload) |
733 |
|
734 |
binding = get_binding(self, indev, mac) |
735 |
if binding is None: |
736 |
# We don't know anything about this interface, so accept the packet |
737 |
# and return |
738 |
logging.debug("Ignoring neighbour solicitation for eui64 %s", ns.tgt) |
739 |
# We don't know what to do with this packet, so let the kernel |
740 |
# handle it |
741 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
742 |
return |
743 |
|
744 |
payload.set_verdict(nfqueue.NF_DROP) |
745 |
|
746 |
if mac != binding.mac: |
747 |
logging.warn("Recieved spoofed NS request for mac %s from tap %s", mac, tap) |
748 |
return |
749 |
|
750 |
subnet = binding.net6 |
751 |
if subnet.net is None: |
752 |
logging.debug("No IPv6 network assigned for the interface") |
753 |
return |
754 |
|
755 |
indevmac = self.get_iface_hw_addr(binding.indev) |
756 |
|
757 |
ifll = subnet.make_ll64(indevmac) |
758 |
if ifll is None: |
759 |
return |
760 |
|
761 |
if not (subnet.net.overlaps(ns.tgt) or str(ns.tgt) == str(ifll)): |
762 |
logging.debug("Received NS for a non-routable IP (%s)", ns.tgt) |
763 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
764 |
return 1 |
765 |
|
766 |
logging.debug("na ether %s %s", binding.mac, ns.src) |
767 |
resp = Ether(src=indevmac, dst=binding.mac)/\ |
768 |
IPv6(src=str(ifll), dst=ns.src)/\ |
769 |
ICMPv6ND_NA(R=1, O=0, S=1, tgt=ns.tgt)/\ |
770 |
ICMPv6NDOptDstLLAddr(lladdr=indevmac) |
771 |
|
772 |
logging.info("NA on %s for %s", binding.indev, ns.tgt) |
773 |
try: |
774 |
self.sendp(resp, binding.indev) |
775 |
except socket.error, e: |
776 |
logging.warn("NA on %s failed: %s", binding.indev, str(e)) |
777 |
except Exception, e: |
778 |
logging.warn("Unkown error during periodic NA on %s: %s", |
779 |
binding.indev, str(e)) |
780 |
|
781 |
def send_periodic_ra(self): |
782 |
# Use a separate thread as this may take a _long_ time with |
783 |
# many interfaces and we want to be responsive in the mean time |
784 |
threading.Thread(target=self._send_periodic_ra).start() |
785 |
|
786 |
def _send_periodic_ra(self): |
787 |
logging.debug("Sending out periodic RAs") |
788 |
start = time.time() |
789 |
i = 0 |
790 |
for binding in self.clients.values(): |
791 |
tap = binding.tap |
792 |
indev = binding.indev |
793 |
mac = binding.mac |
794 |
subnet = binding.net6 |
795 |
if subnet.net is None: |
796 |
logging.debug("Skipping periodic RA on interface %s," |
797 |
" as it is not IPv6-connected", tap) |
798 |
continue |
799 |
indevmac = self.get_iface_hw_addr(indev) |
800 |
ifll = subnet.make_ll64(indevmac) |
801 |
if ifll is None: |
802 |
continue |
803 |
resp = Ether(src=indevmac)/\ |
804 |
IPv6(src=str(ifll))/ICMPv6ND_RA(routerlifetime=14400)/\ |
805 |
ICMPv6NDOptPrefixInfo(prefix=str(subnet.prefix), |
806 |
prefixlen=subnet.prefixlen) |
807 |
if self.ipv6_nameservers: |
808 |
resp /= ICMPv6NDOptRDNSS(dns=self.ipv6_nameservers, |
809 |
lifetime=self.ra_period * 3) |
810 |
try: |
811 |
self.sendp(resp, indev) |
812 |
except socket.error, e: |
813 |
logging.warn("Periodic RA on %s failed: %s", tap, str(e)) |
814 |
except Exception, e: |
815 |
logging.warn("Unkown error during periodic RA on %s: %s", |
816 |
tap, str(e)) |
817 |
i += 1 |
818 |
logging.debug("Sent %d RAs in %.2f seconds", i, time.time() - start) |
819 |
|
820 |
def serve(self): |
821 |
""" Safely perform the main loop, freeing all resources upon exit |
822 |
|
823 |
""" |
824 |
try: |
825 |
self._serve() |
826 |
finally: |
827 |
self._cleanup() |
828 |
|
829 |
def _serve(self): |
830 |
""" Loop forever, serving DHCP requests |
831 |
|
832 |
""" |
833 |
self.build_config() |
834 |
|
835 |
# Yes, we are accessing _fd directly, but it's the only way to have a |
836 |
# single select() loop ;-) |
837 |
iwfd = self.notifier._fd # pylint: disable=W0212 |
838 |
|
839 |
start = time.time() |
840 |
if self.ipv6_enabled: |
841 |
timeout = self.ra_period |
842 |
self.send_periodic_ra() |
843 |
else: |
844 |
timeout = None |
845 |
|
846 |
while True: |
847 |
rlist, _, xlist = select(self.nfq.keys() + [iwfd], [], [], timeout) |
848 |
if xlist: |
849 |
logging.warn("Warning: Exception on %s", |
850 |
", ".join([ str(fd) for fd in xlist])) |
851 |
|
852 |
if rlist: |
853 |
if iwfd in rlist: |
854 |
# First check if there are any inotify (= configuration change) |
855 |
# events |
856 |
self.notifier.read_events() |
857 |
self.notifier.process_events() |
858 |
rlist.remove(iwfd) |
859 |
|
860 |
for fd in rlist: |
861 |
try: |
862 |
self.nfq[fd].process_pending() |
863 |
except RuntimeError, e: |
864 |
logging.warn("Error processing fd %d: %s", fd, str(e)) |
865 |
except Exception, e: |
866 |
logging.warn("Unknown error processing fd %d: %s", |
867 |
fd, str(e)) |
868 |
|
869 |
if self.ipv6_enabled: |
870 |
# Calculate the new timeout |
871 |
timeout = self.ra_period - (time.time() - start) |
872 |
|
873 |
if timeout <= 0: |
874 |
start = time.time() |
875 |
self.send_periodic_ra() |
876 |
timeout = self.ra_period - (time.time() - start) |
877 |
|
878 |
|
879 |
if __name__ == "__main__": |
880 |
import capng |
881 |
import optparse |
882 |
from cStringIO import StringIO |
883 |
from pwd import getpwnam, getpwuid |
884 |
from configobj import ConfigObj, ConfigObjError, flatten_errors |
885 |
|
886 |
import validate |
887 |
|
888 |
validator = validate.Validator() |
889 |
|
890 |
def is_ip_list(value, family=4): |
891 |
try: |
892 |
family = int(family) |
893 |
except ValueError: |
894 |
raise validate.VdtParamError(family) |
895 |
if isinstance(value, (str, unicode)): |
896 |
value = [value] |
897 |
if not isinstance(value, list): |
898 |
raise validate.VdtTypeError(value) |
899 |
|
900 |
for entry in value: |
901 |
try: |
902 |
ip = IPy.IP(entry) |
903 |
except ValueError: |
904 |
raise validate.VdtValueError(entry) |
905 |
|
906 |
if ip.version() != family: |
907 |
raise validate.VdtValueError(entry) |
908 |
return value |
909 |
|
910 |
validator.functions["ip_addr_list"] = is_ip_list |
911 |
config_spec = StringIO(CONFIG_SPEC) |
912 |
|
913 |
|
914 |
parser = optparse.OptionParser() |
915 |
parser.add_option("-c", "--config", dest="config_file", |
916 |
help="The location of the data files", metavar="FILE", |
917 |
default=DEFAULT_CONFIG) |
918 |
parser.add_option("-d", "--debug", action="store_true", dest="debug", |
919 |
help="Turn on debugging messages") |
920 |
parser.add_option("-f", "--foreground", action="store_false", |
921 |
dest="daemonize", default=True, |
922 |
help="Do not daemonize, stay in the foreground") |
923 |
|
924 |
|
925 |
opts, args = parser.parse_args() |
926 |
|
927 |
try: |
928 |
config = ConfigObj(opts.config_file, configspec=config_spec) |
929 |
except ConfigObjError, err: |
930 |
sys.stderr.write("Failed to parse config file %s: %s" % |
931 |
(opts.config_file, str(err))) |
932 |
sys.exit(1) |
933 |
|
934 |
results = config.validate(validator) |
935 |
if results != True: |
936 |
logging.fatal("Configuration file validation failed! See errors below:") |
937 |
for (section_list, key, unused) in flatten_errors(config, results): |
938 |
if key is not None: |
939 |
logging.fatal(" '%s' in section '%s' failed validation", |
940 |
key, ", ".join(section_list)) |
941 |
else: |
942 |
logging.fatal(" Section '%s' is missing", |
943 |
", ".join(section_list)) |
944 |
sys.exit(1) |
945 |
|
946 |
logger = logging.getLogger() |
947 |
if opts.debug: |
948 |
logger.setLevel(logging.DEBUG) |
949 |
else: |
950 |
logger.setLevel(logging.INFO) |
951 |
|
952 |
if opts.daemonize: |
953 |
logfile = os.path.join(config["general"]["logdir"], LOG_FILENAME) |
954 |
handler = logging.handlers.RotatingFileHandler(logfile, |
955 |
maxBytes=2097152) |
956 |
else: |
957 |
handler = logging.StreamHandler() |
958 |
|
959 |
handler.setFormatter(logging.Formatter(LOG_FORMAT)) |
960 |
logger.addHandler(handler) |
961 |
|
962 |
if opts.daemonize: |
963 |
pidfile = daemon.pidlockfile.TimeoutPIDLockFile( |
964 |
config["general"]["pidfile"], 10) |
965 |
# Remove any stale PID files, left behind by previous invocations |
966 |
if daemon.runner.is_pidfile_stale(pidfile): |
967 |
logger.warning("Removing stale PID lock file %s", pidfile.path) |
968 |
pidfile.break_lock() |
969 |
|
970 |
d = daemon.DaemonContext(pidfile=pidfile, |
971 |
umask=0022, |
972 |
stdout=handler.stream, |
973 |
stderr=handler.stream, |
974 |
files_preserve=[handler.stream]) |
975 |
try: |
976 |
d.open() |
977 |
except (daemon.pidlockfile.AlreadyLocked, LockTimeout): |
978 |
logger.critical("Failed to lock pidfile %s," |
979 |
" another instance running?", pidfile.path) |
980 |
sys.exit(1) |
981 |
|
982 |
logging.info("Starting up") |
983 |
|
984 |
proxy_opts = {} |
985 |
if config["dhcp"].as_bool("enable_dhcp"): |
986 |
proxy_opts.update({ |
987 |
"dhcp_queue_num": config["dhcp"].as_int("dhcp_queue"), |
988 |
"dhcp_lease_lifetime": config["dhcp"].as_int("lease_lifetime"), |
989 |
"dhcp_lease_renewal": config["dhcp"].as_int("lease_renewal"), |
990 |
"dhcp_server_ip": config["dhcp"]["server_ip"], |
991 |
"dhcp_nameservers": config["dhcp"]["nameservers"], |
992 |
"dhcp_domain": config["dhcp"]["domain"], |
993 |
}) |
994 |
|
995 |
if config["ipv6"].as_bool("enable_ipv6"): |
996 |
proxy_opts.update({ |
997 |
"rs_queue_num": config["ipv6"].as_int("rs_queue"), |
998 |
"ns_queue_num": config["ipv6"].as_int("ns_queue"), |
999 |
"ra_period": config["ipv6"].as_int("ra_period"), |
1000 |
"ipv6_nameservers": config["ipv6"]["nameservers"], |
1001 |
}) |
1002 |
|
1003 |
# pylint: disable=W0142 |
1004 |
proxy = VMNetProxy(data_path=config["general"]["datapath"], **proxy_opts) |
1005 |
|
1006 |
# Drop all capabilities except CAP_NET_RAW and change uid |
1007 |
try: |
1008 |
uid = getpwuid(config["general"].as_int("user")) |
1009 |
except ValueError: |
1010 |
uid = getpwnam(config["general"]["user"]) |
1011 |
|
1012 |
logging.debug("Setting capabilities and changing uid") |
1013 |
logging.debug("User: %s, uid: %d, gid: %d", |
1014 |
config["general"]["user"], uid.pw_uid, uid.pw_gid) |
1015 |
|
1016 |
# Keep only the capabilities we need |
1017 |
# CAP_NET_ADMIN: we need to send nfqueue packet verdicts to a netlinkgroup |
1018 |
capng.capng_clear(capng.CAPNG_SELECT_BOTH) |
1019 |
capng.capng_update(capng.CAPNG_ADD, |
1020 |
capng.CAPNG_EFFECTIVE|capng.CAPNG_PERMITTED, |
1021 |
capng.CAP_NET_ADMIN) |
1022 |
capng.capng_change_id(uid.pw_uid, uid.pw_gid, |
1023 |
capng.CAPNG_DROP_SUPP_GRP|capng.CAPNG_CLEAR_BOUNDING) |
1024 |
|
1025 |
logging.info("Ready to serve requests") |
1026 |
try: |
1027 |
proxy.serve() |
1028 |
except Exception: |
1029 |
if opts.daemonize: |
1030 |
exc = "".join(traceback.format_exception(*sys.exc_info())) |
1031 |
logging.critical(exc) |
1032 |
raise |
1033 |
|
1034 |
|
1035 |
# vim: set ts=4 sts=4 sw=4 et : |