root / nfdhcpd @ fac9f928
History | View | Annotate | Download (37.8 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 signal |
24 |
import errno |
25 |
import re |
26 |
import sys |
27 |
import glob |
28 |
import time |
29 |
import logging |
30 |
import logging.handlers |
31 |
import threading |
32 |
import traceback |
33 |
|
34 |
import daemon |
35 |
import daemon.runner |
36 |
import daemon.pidlockfile |
37 |
import nfqueue |
38 |
import pyinotify |
39 |
import setproctitle |
40 |
from lockfile import LockTimeout |
41 |
|
42 |
import IPy |
43 |
import socket |
44 |
import select |
45 |
from socket import AF_INET, AF_INET6 |
46 |
|
47 |
from scapy.data import ETH_P_ALL |
48 |
from scapy.packet import BasePacket |
49 |
from scapy.layers.l2 import Ether |
50 |
from scapy.layers.inet import IP, UDP |
51 |
from scapy.layers.inet6 import IPv6, ICMPv6ND_RA, ICMPv6ND_NA, \ |
52 |
ICMPv6NDOptDstLLAddr, \ |
53 |
ICMPv6NDOptPrefixInfo, \ |
54 |
ICMPv6NDOptRDNSS |
55 |
from scapy.layers.dhcp import BOOTP, DHCP |
56 |
|
57 |
|
58 |
DEFAULT_CONFIG = "/etc/nfdhcpd/nfdhcpd.conf" |
59 |
DEFAULT_PATH = "/var/run/ganeti-dhcpd" |
60 |
DEFAULT_USER = "nobody" |
61 |
DEFAULT_LEASE_LIFETIME = 604800 # 1 week |
62 |
DEFAULT_LEASE_RENEWAL = 600 # 10 min |
63 |
DEFAULT_RA_PERIOD = 300 # seconds |
64 |
DHCP_DUMMY_SERVER_IP = "1.2.3.4" |
65 |
|
66 |
LOG_FILENAME = "nfdhcpd.log" |
67 |
|
68 |
SYSFS_NET = "/sys/class/net" |
69 |
|
70 |
LOG_FORMAT = "%(asctime)-15s %(levelname)-8s %(message)s" |
71 |
|
72 |
# Configuration file specification (see configobj documentation) |
73 |
CONFIG_SPEC = """ |
74 |
[general] |
75 |
pidfile = string() |
76 |
datapath = string() |
77 |
logdir = string() |
78 |
user = string() |
79 |
|
80 |
[dhcp] |
81 |
enable_dhcp = boolean(default=True) |
82 |
lease_lifetime = integer(min=0, max=4294967295) |
83 |
lease_renewal = integer(min=0, max=4294967295) |
84 |
server_ip = ip_addr() |
85 |
dhcp_queue = integer(min=0, max=65535) |
86 |
nameservers = ip_addr_list(family=4) |
87 |
domain = string(default=None) |
88 |
|
89 |
[ipv6] |
90 |
enable_ipv6 = boolean(default=True) |
91 |
ra_period = integer(min=1, max=4294967295) |
92 |
rs_queue = integer(min=0, max=65535) |
93 |
ns_queue = integer(min=0, max=65535) |
94 |
nameservers = ip_addr_list(family=6) |
95 |
""" |
96 |
|
97 |
|
98 |
DHCPDISCOVER = 1 |
99 |
DHCPOFFER = 2 |
100 |
DHCPREQUEST = 3 |
101 |
DHCPDECLINE = 4 |
102 |
DHCPACK = 5 |
103 |
DHCPNAK = 6 |
104 |
DHCPRELEASE = 7 |
105 |
DHCPINFORM = 8 |
106 |
|
107 |
DHCP_TYPES = { |
108 |
DHCPDISCOVER: "DHCPDISCOVER", |
109 |
DHCPOFFER: "DHCPOFFER", |
110 |
DHCPREQUEST: "DHCPREQUEST", |
111 |
DHCPDECLINE: "DHCPDECLINE", |
112 |
DHCPACK: "DHCPACK", |
113 |
DHCPNAK: "DHCPNAK", |
114 |
DHCPRELEASE: "DHCPRELEASE", |
115 |
DHCPINFORM: "DHCPINFORM", |
116 |
} |
117 |
|
118 |
DHCP_REQRESP = { |
119 |
DHCPDISCOVER: DHCPOFFER, |
120 |
DHCPREQUEST: DHCPACK, |
121 |
DHCPINFORM: DHCPACK, |
122 |
} |
123 |
|
124 |
|
125 |
def get_indev(payload): |
126 |
try: |
127 |
indev_ifindex = payload.get_physindev() |
128 |
if indev_ifindex: |
129 |
logging.debug(" - Incoming packet from bridge with ifindex %s", |
130 |
indev_ifindex) |
131 |
return indev_ifindex |
132 |
except AttributeError: |
133 |
#TODO: return error value |
134 |
logging.debug("No get_physindev() supported") |
135 |
return 0 |
136 |
|
137 |
indev_ifindex = payload.get_indev() |
138 |
logging.debug(" - Incoming packet from tap with ifindex %s", indev_ifindex) |
139 |
|
140 |
return indev_ifindex |
141 |
|
142 |
|
143 |
def parse_binding_file(path): |
144 |
""" Read a client configuration from a tap file |
145 |
|
146 |
""" |
147 |
logging.info("Parsing binding file %s", path) |
148 |
try: |
149 |
iffile = open(path, 'r') |
150 |
except EnvironmentError, e: |
151 |
logging.warn(" - Unable to open binding file %s: %s", path, str(e)) |
152 |
return None |
153 |
|
154 |
tap = os.path.basename(path) |
155 |
indev = None |
156 |
mac = None |
157 |
ip = None |
158 |
hostname = None |
159 |
subnet = None |
160 |
gateway = None |
161 |
subnet6 = None |
162 |
gateway6 = None |
163 |
eui64 = None |
164 |
|
165 |
def get_value(line): |
166 |
v = line.strip().split('=')[1] |
167 |
if v == '': |
168 |
return None |
169 |
return v |
170 |
|
171 |
for line in iffile: |
172 |
if line.startswith("IP="): |
173 |
ip = get_value(line) |
174 |
elif line.startswith("MAC="): |
175 |
mac = get_value(line) |
176 |
elif line.startswith("HOSTNAME="): |
177 |
hostname = get_value(line) |
178 |
elif line.startswith("INDEV="): |
179 |
indev = get_value(line) |
180 |
elif line.startswith("SUBNET="): |
181 |
subnet = get_value(line) |
182 |
elif line.startswith("GATEWAY="): |
183 |
gateway = get_value(line) |
184 |
elif line.startswith("SUBNET6="): |
185 |
subnet6 = get_value(line) |
186 |
elif line.startswith("GATEWAY6="): |
187 |
gateway6 = get_value(line) |
188 |
elif line.startswith("EUI64="): |
189 |
eui64 = get_value(line) |
190 |
|
191 |
try: |
192 |
return Client(tap=tap, mac=mac, ip=ip, hostname=hostname, |
193 |
indev=indev, subnet=subnet, gateway=gateway, |
194 |
subnet6=subnet6, gateway6=gateway6, eui64=eui64 ) |
195 |
except ValueError: |
196 |
logging.warning(" - Cannot add client for host %s and IP %s on tap %s", |
197 |
hostname, ip, tap) |
198 |
return None |
199 |
|
200 |
|
201 |
class ClientFileHandler(pyinotify.ProcessEvent): |
202 |
def __init__(self, server): |
203 |
pyinotify.ProcessEvent.__init__(self) |
204 |
self.server = server |
205 |
|
206 |
def process_IN_DELETE(self, event): # pylint: disable=C0103 |
207 |
""" Delete file handler |
208 |
|
209 |
Currently this removes an interface from the watch list |
210 |
|
211 |
""" |
212 |
self.server.remove_tap(event.name) |
213 |
|
214 |
def process_IN_CLOSE_WRITE(self, event): # pylint: disable=C0103 |
215 |
""" Add file handler |
216 |
|
217 |
Currently this adds an interface to the watch list |
218 |
|
219 |
""" |
220 |
self.server.add_tap(os.path.join(event.path, event.name)) |
221 |
|
222 |
|
223 |
class Client(object): |
224 |
def __init__(self, tap=None, indev=None, |
225 |
mac=None, ip=None, hostname=None, |
226 |
subnet=None, gateway=None, |
227 |
subnet6=None, gateway6=None, eui64=None): |
228 |
self.mac = mac |
229 |
self.ip = ip |
230 |
self.hostname = hostname |
231 |
self.indev = indev |
232 |
self.tap = tap |
233 |
self.subnet = subnet |
234 |
self.gateway = gateway |
235 |
self.net = Subnet(net=subnet, gw=gateway, dev=tap) |
236 |
self.subnet6 = subnet6 |
237 |
self.gateway6 = gateway6 |
238 |
self.net6 = Subnet(net=subnet6, gw=gateway6, dev=tap) |
239 |
self.eui64 = eui64 |
240 |
self.open_socket() |
241 |
|
242 |
def is_valid(self): |
243 |
return self.mac is not None and self.hostname is not None |
244 |
|
245 |
|
246 |
def open_socket(self): |
247 |
|
248 |
logging.info(" - Opening L2 socket and binding to %s", self.tap) |
249 |
try: |
250 |
s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, ETH_P_ALL) |
251 |
s.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 0) |
252 |
s.bind((self.tap, ETH_P_ALL)) |
253 |
self.socket = s |
254 |
except socket.error, e: |
255 |
logging.warning(" - Cannot open socket %s", e) |
256 |
|
257 |
|
258 |
def sendp(self, data): |
259 |
|
260 |
if isinstance(data, BasePacket): |
261 |
data = str(data) |
262 |
|
263 |
logging.debug(" - Sending raw packet %r", data) |
264 |
|
265 |
try: |
266 |
count = self.socket.send(data, socket.MSG_DONTWAIT) |
267 |
except socket.error, e: |
268 |
logging.warn(" - Send with MSG_DONTWAIT failed: %s", str(e)) |
269 |
self.socket.close() |
270 |
self.open_socket() |
271 |
raise e |
272 |
|
273 |
ldata = len(data) |
274 |
logging.debug(" - Sent %d bytes on %s", count, self.tap) |
275 |
if count != ldata: |
276 |
logging.warn(" - Truncated msg: %d/%d bytes sent", |
277 |
count, ldata) |
278 |
|
279 |
|
280 |
class Subnet(object): |
281 |
def __init__(self, net=None, gw=None, dev=None): |
282 |
if isinstance(net, str): |
283 |
try: |
284 |
self.net = IPy.IP(net) |
285 |
except ValueError, e: |
286 |
logging.warning(" - IPy error: %s", e) |
287 |
raise e |
288 |
else: |
289 |
self.net = net |
290 |
self.gw = gw |
291 |
self.dev = dev |
292 |
|
293 |
@property |
294 |
def netmask(self): |
295 |
""" Return the netmask in textual representation |
296 |
|
297 |
""" |
298 |
return str(self.net.netmask()) |
299 |
|
300 |
@property |
301 |
def broadcast(self): |
302 |
""" Return the broadcast address in textual representation |
303 |
|
304 |
""" |
305 |
return str(self.net.broadcast()) |
306 |
|
307 |
@property |
308 |
def prefix(self): |
309 |
""" Return the network as an IPy.IP |
310 |
|
311 |
""" |
312 |
return self.net.net() |
313 |
|
314 |
@property |
315 |
def prefixlen(self): |
316 |
""" Return the prefix length as an integer |
317 |
|
318 |
""" |
319 |
return self.net.prefixlen() |
320 |
|
321 |
@staticmethod |
322 |
def _make_eui64(net, mac): |
323 |
""" Compute an EUI-64 address from an EUI-48 (MAC) address |
324 |
|
325 |
""" |
326 |
if mac is None: |
327 |
return None |
328 |
comp = mac.split(":") |
329 |
prefix = IPy.IP(net).net().strFullsize().split(":")[:4] |
330 |
eui64 = comp[:3] + ["ff", "fe"] + comp[3:] |
331 |
eui64[0] = "%02x" % (int(eui64[0], 16) ^ 0x02) |
332 |
for l in range(0, len(eui64), 2): |
333 |
prefix += ["".join(eui64[l:l+2])] |
334 |
return IPy.IP(":".join(prefix)) |
335 |
|
336 |
def make_eui64(self, mac): |
337 |
""" Compute an EUI-64 address from an EUI-48 (MAC) address in this |
338 |
subnet. |
339 |
|
340 |
""" |
341 |
return self._make_eui64(self.net, mac) |
342 |
|
343 |
def make_ll64(self, mac): |
344 |
""" Compute an IPv6 Link-local address from an EUI-48 (MAC) address |
345 |
|
346 |
""" |
347 |
return self._make_eui64("fe80::", mac) |
348 |
|
349 |
|
350 |
class VMNetProxy(object): # pylint: disable=R0902 |
351 |
def __init__(self, data_path, dhcp_queue_num=None, # pylint: disable=R0913 |
352 |
rs_queue_num=None, ns_queue_num=None, |
353 |
dhcp_lease_lifetime=DEFAULT_LEASE_LIFETIME, |
354 |
dhcp_lease_renewal=DEFAULT_LEASE_RENEWAL, |
355 |
dhcp_domain='', |
356 |
dhcp_server_ip=DHCP_DUMMY_SERVER_IP, dhcp_nameservers=None, |
357 |
ra_period=DEFAULT_RA_PERIOD, ipv6_nameservers=None): |
358 |
|
359 |
try: |
360 |
getattr(nfqueue.payload, 'get_physindev') |
361 |
self.mac_indexed_clients = False |
362 |
except AttributeError: |
363 |
self.mac_indexed_clients = True |
364 |
self.data_path = data_path |
365 |
self.lease_lifetime = dhcp_lease_lifetime |
366 |
self.lease_renewal = dhcp_lease_renewal |
367 |
self.dhcp_domain = dhcp_domain |
368 |
self.dhcp_server_ip = dhcp_server_ip |
369 |
self.ra_period = ra_period |
370 |
if dhcp_nameservers is None: |
371 |
self.dhcp_nameserver = [] |
372 |
else: |
373 |
self.dhcp_nameservers = dhcp_nameservers |
374 |
|
375 |
if ipv6_nameservers is None: |
376 |
self.ipv6_nameservers = [] |
377 |
else: |
378 |
self.ipv6_nameservers = ipv6_nameservers |
379 |
|
380 |
self.ipv6_enabled = False |
381 |
|
382 |
self.clients = {} |
383 |
#self.subnets = {} |
384 |
#self.ifaces = {} |
385 |
#self.v6nets = {} |
386 |
self.nfq = {} |
387 |
|
388 |
# Inotify setup |
389 |
self.wm = pyinotify.WatchManager() |
390 |
mask = pyinotify.EventsCodes.ALL_FLAGS["IN_DELETE"] |
391 |
mask |= pyinotify.EventsCodes.ALL_FLAGS["IN_CLOSE_WRITE"] |
392 |
inotify_handler = ClientFileHandler(self) |
393 |
self.notifier = pyinotify.Notifier(self.wm, inotify_handler) |
394 |
self.wm.add_watch(self.data_path, mask, rec=True) |
395 |
|
396 |
# NFQUEUE setup |
397 |
if dhcp_queue_num is not None: |
398 |
self._setup_nfqueue(dhcp_queue_num, AF_INET, self.dhcp_response, 0) |
399 |
|
400 |
if rs_queue_num is not None: |
401 |
self._setup_nfqueue(rs_queue_num, AF_INET6, self.rs_response, 10) |
402 |
self.ipv6_enabled = True |
403 |
|
404 |
if ns_queue_num is not None: |
405 |
self._setup_nfqueue(ns_queue_num, AF_INET6, self.ns_response, 10) |
406 |
self.ipv6_enabled = True |
407 |
|
408 |
def get_binding(self, ifindex, mac): |
409 |
try: |
410 |
if self.mac_indexed_clients: |
411 |
logging.debug(" - Getting binding for mac %s", mac) |
412 |
b = self.clients[mac] |
413 |
else: |
414 |
logging.debug(" - Getting binding for ifindex %s", ifindex) |
415 |
b = self.clients[ifindex] |
416 |
return b |
417 |
except KeyError: |
418 |
logging.debug(" - No client found for mac / ifindex %s / %s", |
419 |
mac, ifindex) |
420 |
return None |
421 |
|
422 |
def _cleanup(self): |
423 |
""" Free all resources for a graceful exit |
424 |
|
425 |
""" |
426 |
logging.info("Cleaning up") |
427 |
|
428 |
logging.debug(" - Closing netfilter queues") |
429 |
for q, _ in self.nfq.values(): |
430 |
q.close() |
431 |
|
432 |
logging.debug(" - Stopping inotify watches") |
433 |
self.notifier.stop() |
434 |
|
435 |
logging.info(" - Cleanup finished") |
436 |
|
437 |
def _setup_nfqueue(self, queue_num, family, callback, pending): |
438 |
logging.info("Setting up NFQUEUE for queue %d, AF %s", |
439 |
queue_num, family) |
440 |
q = nfqueue.queue() |
441 |
q.set_callback(callback) |
442 |
q.fast_open(queue_num, family) |
443 |
q.set_queue_maxlen(5000) |
444 |
# This is mandatory for the queue to operate |
445 |
q.set_mode(nfqueue.NFQNL_COPY_PACKET) |
446 |
self.nfq[q.get_fd()] = (q, pending) |
447 |
logging.debug(" - Successfully set up NFQUEUE %d", queue_num) |
448 |
|
449 |
def build_config(self): |
450 |
self.clients.clear() |
451 |
|
452 |
for path in glob.glob(os.path.join(self.data_path, "*")): |
453 |
self.add_tap(path) |
454 |
|
455 |
self.print_clients() |
456 |
|
457 |
def get_ifindex(self, iface): |
458 |
""" Get the interface index from sysfs |
459 |
|
460 |
""" |
461 |
logging.debug(" - Getting ifindex for interface %s from sysfs", iface) |
462 |
|
463 |
path = os.path.abspath(os.path.join(SYSFS_NET, iface, "ifindex")) |
464 |
if not path.startswith(SYSFS_NET): |
465 |
return None |
466 |
|
467 |
ifindex = None |
468 |
|
469 |
try: |
470 |
f = open(path, 'r') |
471 |
except EnvironmentError: |
472 |
logging.debug(" - %s is probably down, removing", iface) |
473 |
self.remove_tap(iface) |
474 |
|
475 |
return ifindex |
476 |
|
477 |
try: |
478 |
ifindex = f.readline().strip() |
479 |
try: |
480 |
ifindex = int(ifindex) |
481 |
except ValueError, e: |
482 |
logging.warn(" - Failed to get ifindex for %s, cannot parse" |
483 |
" sysfs output '%s'", iface, ifindex) |
484 |
except EnvironmentError, e: |
485 |
logging.warn(" - Error reading %s's ifindex from sysfs: %s", |
486 |
iface, str(e)) |
487 |
self.remove_tap(iface) |
488 |
finally: |
489 |
f.close() |
490 |
|
491 |
return ifindex |
492 |
|
493 |
def get_iface_hw_addr(self, iface): |
494 |
""" Get the interface hardware address from sysfs |
495 |
|
496 |
""" |
497 |
logging.debug(" - Getting mac for iface %s", iface) |
498 |
path = os.path.abspath(os.path.join(SYSFS_NET, iface, "address")) |
499 |
if not path.startswith(SYSFS_NET): |
500 |
return None |
501 |
|
502 |
addr = None |
503 |
try: |
504 |
f = open(path, 'r') |
505 |
except EnvironmentError: |
506 |
logging.debug(" - %s is probably down, removing", iface) |
507 |
self.remove_tap(iface) |
508 |
return addr |
509 |
|
510 |
try: |
511 |
addr = f.readline().strip() |
512 |
except EnvironmentError, e: |
513 |
logging.warn(" - Failed to read hw address for %s from sysfs: %s", |
514 |
iface, str(e)) |
515 |
finally: |
516 |
f.close() |
517 |
|
518 |
return addr |
519 |
|
520 |
def add_tap(self, path): |
521 |
""" Add an interface to monitor |
522 |
|
523 |
""" |
524 |
tap = os.path.basename(path) |
525 |
|
526 |
logging.info("Updating configuration for %s", tap) |
527 |
b = parse_binding_file(path) |
528 |
if b is None: |
529 |
return |
530 |
ifindex = self.get_ifindex(b.tap) |
531 |
|
532 |
if ifindex is None: |
533 |
logging.warn(" - Stale configuration for %s found", tap) |
534 |
else: |
535 |
if b.is_valid(): |
536 |
if self.mac_indexed_clients: |
537 |
self.clients[b.mac] = b |
538 |
else: |
539 |
self.clients[ifindex] = b |
540 |
logging.debug(" - Added client:") |
541 |
logging.debug(" + %5s: %10s %20s %7s %15s", |
542 |
ifindex, b.hostname, b.mac, b.tap, b.ip) |
543 |
|
544 |
def remove_tap(self, tap): |
545 |
""" Cleanup clients on a removed interface |
546 |
|
547 |
""" |
548 |
try: |
549 |
for k, cl in self.clients.items(): |
550 |
if cl.tap == tap: |
551 |
logging.info("Removing client %s and closing socket on %s", |
552 |
cl.hostname, cl.tap) |
553 |
logging.debug(" - %10s | %10s %20s %10s %20s", |
554 |
k, cl.hostname, cl.mac, cl.tap, cl.ip) |
555 |
cl.socket.close() |
556 |
del self.clients[k] |
557 |
except: |
558 |
logging.debug("Client on %s disappeared!!!", tap) |
559 |
|
560 |
|
561 |
def dhcp_response(self, arg1, arg2=None): # pylint: disable=W0613,R0914 |
562 |
""" Generate a reply to bnetfilter-queue-deva BOOTP/DHCP request |
563 |
|
564 |
""" |
565 |
logging.info(" * Processing pending DHCP request") |
566 |
# Workaround for supporting both squeezy's nfqueue-bindings-python |
567 |
# and wheezy's python-nfqueue because for some reason the function's |
568 |
# signature has changed and has broken compatibility |
569 |
# See bug http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=718894 |
570 |
if arg2: |
571 |
payload = arg2 |
572 |
else: |
573 |
payload = arg1 |
574 |
# Decode the response - NFQUEUE relays IP packets |
575 |
pkt = IP(payload.get_data()) |
576 |
#logging.debug(pkt.show()) |
577 |
|
578 |
# Get the client MAC address |
579 |
resp = pkt.getlayer(BOOTP).copy() |
580 |
hlen = resp.hlen |
581 |
mac = resp.chaddr[:hlen].encode("hex") |
582 |
mac, _ = re.subn(r'([0-9a-fA-F]{2})', r'\1:', mac, hlen - 1) |
583 |
|
584 |
# Server responses are always BOOTREPLYs |
585 |
resp.op = "BOOTREPLY" |
586 |
del resp.payload |
587 |
|
588 |
indev = get_indev(payload) |
589 |
|
590 |
binding = self.get_binding(indev, mac) |
591 |
if binding is None: |
592 |
# We don't know anything about this interface, so accept the packet |
593 |
# and return |
594 |
logging.debug(" - Ignoring DHCP request on unknown iface %s", indev) |
595 |
# We don't know what to do with this packet, so let the kernel |
596 |
# handle it |
597 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
598 |
return |
599 |
|
600 |
# Signal the kernel that it shouldn't further process the packet |
601 |
payload.set_verdict(nfqueue.NF_DROP) |
602 |
|
603 |
if mac != binding.mac: |
604 |
logging.warn(" - Recieved spoofed DHCP request: mac %s, indev %s", |
605 |
mac, indev) |
606 |
return |
607 |
|
608 |
if not binding.ip: |
609 |
logging.info(" - No IP found in binding file.") |
610 |
return |
611 |
|
612 |
logging.info(" - Generating DHCP response:" |
613 |
" host %s, mac %s, tap %s, indev %s", |
614 |
binding.hostname, mac, binding.tap, indev) |
615 |
|
616 |
|
617 |
resp = Ether(dst=mac, src=self.get_iface_hw_addr(binding.indev))/\ |
618 |
IP(src=DHCP_DUMMY_SERVER_IP, dst=binding.ip)/\ |
619 |
UDP(sport=pkt.dport, dport=pkt.sport)/resp |
620 |
subnet = binding.net |
621 |
|
622 |
if not DHCP in pkt: |
623 |
logging.warn(" - Invalid request from %s on %s, no DHCP" |
624 |
" payload found", binding.mac, binding.tap) |
625 |
return |
626 |
|
627 |
dhcp_options = [] |
628 |
requested_addr = binding.ip |
629 |
for opt in pkt[DHCP].options: |
630 |
if type(opt) is tuple and opt[0] == "message-type": |
631 |
req_type = opt[1] |
632 |
if type(opt) is tuple and opt[0] == "requested_addr": |
633 |
requested_addr = opt[1] |
634 |
|
635 |
logging.info(" - %s from %s on %s", DHCP_TYPES.get(req_type, "UNKNOWN"), |
636 |
binding.mac, binding.tap) |
637 |
|
638 |
if self.dhcp_domain: |
639 |
domainname = self.dhcp_domain |
640 |
else: |
641 |
domainname = binding.hostname.split('.', 1)[-1] |
642 |
|
643 |
if req_type == DHCPREQUEST and requested_addr != binding.ip: |
644 |
resp_type = DHCPNAK |
645 |
logging.info(" - Sending DHCPNAK to %s on %s: requested %s" |
646 |
" instead of %s", binding.mac, binding.tap, |
647 |
requested_addr, binding.ip) |
648 |
|
649 |
elif req_type in (DHCPDISCOVER, DHCPREQUEST): |
650 |
resp_type = DHCP_REQRESP[req_type] |
651 |
resp.yiaddr = binding.ip |
652 |
dhcp_options += [ |
653 |
("hostname", binding.hostname), |
654 |
("domain", domainname), |
655 |
("broadcast_address", str(subnet.broadcast)), |
656 |
("subnet_mask", str(subnet.netmask)), |
657 |
("renewal_time", self.lease_renewal), |
658 |
("lease_time", self.lease_lifetime), |
659 |
] |
660 |
if subnet.gw: |
661 |
dhcp_options += [("router", subnet.gw)] |
662 |
dhcp_options += [("name_server", x) for x in self.dhcp_nameservers] |
663 |
|
664 |
elif req_type == DHCPINFORM: |
665 |
resp_type = DHCP_REQRESP[req_type] |
666 |
dhcp_options += [ |
667 |
("hostname", binding.hostname), |
668 |
("domain", domainname), |
669 |
] |
670 |
dhcp_options += [("name_server", x) for x in self.dhcp_nameservers] |
671 |
|
672 |
elif req_type == DHCPRELEASE: |
673 |
# Log and ignore |
674 |
logging.info(" - DHCPRELEASE from %s on %s", |
675 |
binding.hostname, binding.tap) |
676 |
return |
677 |
|
678 |
# Finally, always add the server identifier and end options |
679 |
dhcp_options += [ |
680 |
("message-type", resp_type), |
681 |
("server_id", DHCP_DUMMY_SERVER_IP), |
682 |
"end" |
683 |
] |
684 |
resp /= DHCP(options=dhcp_options) |
685 |
|
686 |
logging.info(" - %s to %s (%s) on %s", DHCP_TYPES[resp_type], mac, |
687 |
binding.ip, binding.tap) |
688 |
try: |
689 |
binding.sendp(resp) |
690 |
except socket.error, e: |
691 |
logging.warn(" - DHCP response on %s (%s) failed: %s", |
692 |
binding.tap, binding.hostname, str(e)) |
693 |
except Exception, e: |
694 |
logging.warn(" - Unkown error during DHCP response on %s (%s): %s", |
695 |
binding.tap, binding.hostname, str(e)) |
696 |
|
697 |
def rs_response(self, arg1, arg2=None): # pylint: disable=W0613 |
698 |
""" Generate a reply to a BOOTP/DHCP request |
699 |
|
700 |
""" |
701 |
logging.info(" * Processing pending RS request") |
702 |
# Workaround for supporting both squeezy's nfqueue-bindings-python |
703 |
# and wheezy's python-nfqueue because for some reason the function's |
704 |
# signature has changed and has broken compatibility |
705 |
# See bug http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=718894 |
706 |
if arg2: |
707 |
payload = arg2 |
708 |
else: |
709 |
payload = arg1 |
710 |
pkt = IPv6(payload.get_data()) |
711 |
#logging.debug(pkt.show()) |
712 |
try: |
713 |
mac = pkt.lladdr |
714 |
except: |
715 |
logging.debug(" - Cannot obtain lladdr in rs") |
716 |
return |
717 |
|
718 |
indev = get_indev(payload) |
719 |
|
720 |
binding = self.get_binding(indev, mac) |
721 |
if binding is None: |
722 |
# We don't know anything about this interface, so accept the packet |
723 |
# and return |
724 |
logging.debug(" - Ignoring router solicitation on for mac %s", mac) |
725 |
# We don't know what to do with this packet, so let the kernel |
726 |
# handle it |
727 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
728 |
return |
729 |
|
730 |
# Signal the kernel that it shouldn't further process the packet |
731 |
payload.set_verdict(nfqueue.NF_DROP) |
732 |
|
733 |
if mac != binding.mac: |
734 |
logging.warn(" - Received spoofed RS request: mac %s, tap %s", |
735 |
mac, binding.tap) |
736 |
return |
737 |
|
738 |
subnet = binding.net6 |
739 |
|
740 |
if subnet.net is None: |
741 |
logging.debug(" - No IPv6 network assigned for tap %s", binding.tap) |
742 |
return |
743 |
|
744 |
indevmac = self.get_iface_hw_addr(binding.indev) |
745 |
ifll = subnet.make_ll64(indevmac) |
746 |
if ifll is None: |
747 |
return |
748 |
|
749 |
logging.info(" - Generating RA for host %s (mac %s) on tap %s", |
750 |
binding.hostname, mac, binding.tap) |
751 |
|
752 |
resp = Ether(src=indevmac)/\ |
753 |
IPv6(src=str(ifll))/ICMPv6ND_RA(routerlifetime=14400)/\ |
754 |
ICMPv6NDOptPrefixInfo(prefix=str(subnet.prefix), |
755 |
prefixlen=subnet.prefixlen) |
756 |
|
757 |
if self.ipv6_nameservers: |
758 |
resp /= ICMPv6NDOptRDNSS(dns=self.ipv6_nameservers, |
759 |
lifetime=self.ra_period * 3) |
760 |
|
761 |
try: |
762 |
binding.sendp(resp) |
763 |
except socket.error, e: |
764 |
logging.warn(" - RA on %s (%s) failed: %s", |
765 |
binding.tap, binding.hostname, str(e)) |
766 |
except Exception, e: |
767 |
logging.warn(" - Unkown error during RA on %s (%s): %s", |
768 |
binding.tap, binding.hostname, str(e)) |
769 |
|
770 |
def ns_response(self, arg1, arg2=None): # pylint: disable=W0613 |
771 |
""" Generate a reply to an ICMPv6 neighbor solicitation |
772 |
|
773 |
""" |
774 |
|
775 |
logging.info(" * Processing pending NS request") |
776 |
# Workaround for supporting both squeezy's nfqueue-bindings-python |
777 |
# and wheezy's python-nfqueue because for some reason the function's |
778 |
# signature has changed and has broken compatibility |
779 |
# See bug http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=718894 |
780 |
if arg2: |
781 |
payload = arg2 |
782 |
else: |
783 |
payload = arg1 |
784 |
|
785 |
ns = IPv6(payload.get_data()) |
786 |
#logging.debug(ns.show()) |
787 |
try: |
788 |
mac = ns.lladdr |
789 |
except: |
790 |
logging.debug(" - Cannot obtain lladdr from ns") |
791 |
return |
792 |
|
793 |
|
794 |
indev = get_indev(payload) |
795 |
|
796 |
binding = self.get_binding(indev, mac) |
797 |
if binding is None: |
798 |
# We don't know anything about this interface, so accept the packet |
799 |
# and return |
800 |
logging.debug(" - Ignoring neighbour solicitation for eui64 %s", |
801 |
ns.tgt) |
802 |
# We don't know what to do with this packet, so let the kernel |
803 |
# handle it |
804 |
payload.set_verdict(nfqueue.NF_ACCEPT) |
805 |
return |
806 |
|
807 |
payload.set_verdict(nfqueue.NF_DROP) |
808 |
|
809 |
if mac != binding.mac: |
810 |
logging.warn(" - Received spoofed NS request" |
811 |
" for mac %s from tap %s", mac, binding.tap) |
812 |
return |
813 |
|
814 |
subnet = binding.net6 |
815 |
if subnet.net is None: |
816 |
logging.debug(" - No IPv6 network assigned for the interface") |
817 |
return |
818 |
|
819 |
indevmac = self.get_iface_hw_addr(binding.indev) |
820 |
|
821 |
ifll = subnet.make_ll64(indevmac) |
822 |
if ifll is None: |
823 |
return |
824 |
|
825 |
if not (subnet.net.overlaps(ns.tgt) or str(ns.tgt) == str(ifll)): |
826 |
logging.debug(" - Received NS for a non-routable IP (%s)", ns.tgt) |
827 |
return 1 |
828 |
|
829 |
logging.info(" - Generating NA for host %s (mac %s) on tap %s", |
830 |
binding.hostname, mac, binding.tap) |
831 |
|
832 |
resp = Ether(src=indevmac, dst=binding.mac)/\ |
833 |
IPv6(src=str(ifll), dst=ns.src)/\ |
834 |
ICMPv6ND_NA(R=1, O=0, S=1, tgt=ns.tgt)/\ |
835 |
ICMPv6NDOptDstLLAddr(lladdr=indevmac) |
836 |
|
837 |
try: |
838 |
binding.sendp(resp) |
839 |
except socket.error, e: |
840 |
logging.warn(" - NA on %s (%s) failed: %s", |
841 |
binding.tap, binding.hostname, str(e)) |
842 |
except Exception, e: |
843 |
logging.warn(" - Unkown error during periodic NA to %s (%s): %s", |
844 |
binding.tap, binding.hostname, str(e)) |
845 |
|
846 |
def send_periodic_ra(self): |
847 |
# Use a separate thread as this may take a _long_ time with |
848 |
# many interfaces and we want to be responsive in the mean time |
849 |
threading.Thread(target=self._send_periodic_ra).start() |
850 |
|
851 |
def _send_periodic_ra(self): |
852 |
logging.info("Sending out periodic RAs") |
853 |
start = time.time() |
854 |
i = 0 |
855 |
for binding in self.clients.values(): |
856 |
tap = binding.tap |
857 |
indev = binding.indev |
858 |
# mac = binding.mac |
859 |
subnet = binding.net6 |
860 |
if subnet.net is None: |
861 |
logging.debug(" - Skipping periodic RA on interface %s," |
862 |
" as it is not IPv6-connected", tap) |
863 |
continue |
864 |
indevmac = self.get_iface_hw_addr(indev) |
865 |
ifll = subnet.make_ll64(indevmac) |
866 |
if ifll is None: |
867 |
continue |
868 |
resp = Ether(src=indevmac)/\ |
869 |
IPv6(src=str(ifll))/ICMPv6ND_RA(routerlifetime=14400)/\ |
870 |
ICMPv6NDOptPrefixInfo(prefix=str(subnet.prefix), |
871 |
prefixlen=subnet.prefixlen) |
872 |
if self.ipv6_nameservers: |
873 |
resp /= ICMPv6NDOptRDNSS(dns=self.ipv6_nameservers, |
874 |
lifetime=self.ra_period * 3) |
875 |
try: |
876 |
binding.sendp(resp) |
877 |
except socket.error, e: |
878 |
logging.warn(" - Periodic RA on %s (%s) failed: %s", |
879 |
tap, binding.hostname, str(e)) |
880 |
except Exception, e: |
881 |
logging.warn(" - Unkown error during periodic RA on %s (%s):" |
882 |
" %s", tap, binding.hostname, str(e)) |
883 |
i += 1 |
884 |
logging.info(" - Sent %d RAs in %.2f seconds", i, time.time() - start) |
885 |
|
886 |
def serve(self): |
887 |
""" Safely perform the main loop, freeing all resources upon exit |
888 |
|
889 |
""" |
890 |
try: |
891 |
self._serve() |
892 |
finally: |
893 |
self._cleanup() |
894 |
|
895 |
def _serve(self): |
896 |
""" Loop forever, serving DHCP requests |
897 |
|
898 |
""" |
899 |
self.build_config() |
900 |
|
901 |
# Yes, we are accessing _fd directly, but it's the only way to have a |
902 |
# single select() loop ;-) |
903 |
iwfd = self.notifier._fd # pylint: disable=W0212 |
904 |
|
905 |
start = time.time() |
906 |
if self.ipv6_enabled: |
907 |
timeout = self.ra_period |
908 |
self.send_periodic_ra() |
909 |
else: |
910 |
timeout = None |
911 |
|
912 |
while True: |
913 |
try: |
914 |
rlist, _, xlist = select.select(self.nfq.keys() + [iwfd], |
915 |
[], [], timeout) |
916 |
except select.error, e: |
917 |
if e[0] == errno.EINTR: |
918 |
logging.debug("select() got interrupted") |
919 |
continue |
920 |
|
921 |
if xlist: |
922 |
logging.warn("Warning: Exception on %s", |
923 |
", ".join([str(fd) for fd in xlist])) |
924 |
|
925 |
if rlist: |
926 |
if iwfd in rlist: |
927 |
# First check if there are any inotify (= configuration change) |
928 |
# events |
929 |
self.notifier.read_events() |
930 |
self.notifier.process_events() |
931 |
rlist.remove(iwfd) |
932 |
|
933 |
logging.debug("Pending requests on fds %s", rlist) |
934 |
|
935 |
for fd in rlist: |
936 |
try: |
937 |
q, num = self.nfq[fd] |
938 |
cnt = q.process_pending(num) |
939 |
logging.debug(" * Processed %d requests on NFQUEUE" |
940 |
" with fd %d", cnt, fd) |
941 |
except RuntimeError, e: |
942 |
logging.warn("Error processing fd %d: %s", fd, str(e)) |
943 |
except Exception, e: |
944 |
logging.warn("Unknown error processing fd %d: %s", |
945 |
fd, str(e)) |
946 |
|
947 |
if self.ipv6_enabled: |
948 |
# Calculate the new timeout |
949 |
timeout = self.ra_period - (time.time() - start) |
950 |
|
951 |
if timeout <= 0: |
952 |
start = time.time() |
953 |
self.send_periodic_ra() |
954 |
timeout = self.ra_period - (time.time() - start) |
955 |
|
956 |
def print_clients(self): |
957 |
logging.info("%10s %20s %20s %10s %20s", |
958 |
'Key', 'Client', 'MAC', 'TAP', 'IP') |
959 |
for k, cl in self.clients.items(): |
960 |
logging.info("%10s | %20s %20s %10s %20s", |
961 |
k, cl.hostname, cl.mac, cl.tap, cl.ip) |
962 |
|
963 |
|
964 |
|
965 |
if __name__ == "__main__": |
966 |
import capng |
967 |
import optparse |
968 |
from cStringIO import StringIO |
969 |
from pwd import getpwnam, getpwuid |
970 |
from configobj import ConfigObj, ConfigObjError, flatten_errors |
971 |
|
972 |
import validate |
973 |
|
974 |
validator = validate.Validator() |
975 |
|
976 |
def is_ip_list(value, family=4): |
977 |
try: |
978 |
family = int(family) |
979 |
except ValueError: |
980 |
raise validate.VdtParamError(family) |
981 |
if isinstance(value, (str, unicode)): |
982 |
value = [value] |
983 |
if not isinstance(value, list): |
984 |
raise validate.VdtTypeError(value) |
985 |
|
986 |
for entry in value: |
987 |
try: |
988 |
ip = IPy.IP(entry) |
989 |
except ValueError: |
990 |
raise validate.VdtValueError(entry) |
991 |
|
992 |
if ip.version() != family: |
993 |
raise validate.VdtValueError(entry) |
994 |
return value |
995 |
|
996 |
validator.functions["ip_addr_list"] = is_ip_list |
997 |
config_spec = StringIO(CONFIG_SPEC) |
998 |
|
999 |
parser = optparse.OptionParser() |
1000 |
parser.add_option("-c", "--config", dest="config_file", |
1001 |
help="The location of the data files", metavar="FILE", |
1002 |
default=DEFAULT_CONFIG) |
1003 |
parser.add_option("-d", "--debug", action="store_true", dest="debug", |
1004 |
help="Turn on debugging messages") |
1005 |
parser.add_option("-f", "--foreground", action="store_false", |
1006 |
dest="daemonize", default=True, |
1007 |
help="Do not daemonize, stay in the foreground") |
1008 |
|
1009 |
opts, args = parser.parse_args() |
1010 |
|
1011 |
try: |
1012 |
config = ConfigObj(opts.config_file, configspec=config_spec) |
1013 |
except ConfigObjError, err: |
1014 |
sys.stderr.write("Failed to parse config file %s: %s" % |
1015 |
(opts.config_file, str(err))) |
1016 |
sys.exit(1) |
1017 |
|
1018 |
results = config.validate(validator) |
1019 |
if results != True: |
1020 |
logging.fatal("Configuration file validation failed! See errors below:") |
1021 |
for (section_list, key, unused) in flatten_errors(config, results): |
1022 |
if key is not None: |
1023 |
logging.fatal(" '%s' in section '%s' failed validation", |
1024 |
key, ", ".join(section_list)) |
1025 |
else: |
1026 |
logging.fatal(" Section '%s' is missing", |
1027 |
", ".join(section_list)) |
1028 |
sys.exit(1) |
1029 |
|
1030 |
try: |
1031 |
uid = getpwuid(config["general"].as_int("user")) |
1032 |
except ValueError: |
1033 |
uid = getpwnam(config["general"]["user"]) |
1034 |
|
1035 |
# Keep only the capabilities we need |
1036 |
# CAP_NET_ADMIN: we need to send nfqueue packet verdicts to a netlinkgroup |
1037 |
# CAP_NET_RAW: we need to reopen socket in case the buffer gets full |
1038 |
# CAP_SETPCAP: needed by capng_change_id() |
1039 |
capng.capng_clear(capng.CAPNG_SELECT_BOTH) |
1040 |
capng.capng_update(capng.CAPNG_ADD, |
1041 |
capng.CAPNG_EFFECTIVE | capng.CAPNG_PERMITTED, |
1042 |
capng.CAP_NET_ADMIN) |
1043 |
capng.capng_update(capng.CAPNG_ADD, |
1044 |
capng.CAPNG_EFFECTIVE | capng.CAPNG_PERMITTED, |
1045 |
capng.CAP_NET_RAW) |
1046 |
capng.capng_update(capng.CAPNG_ADD, |
1047 |
capng.CAPNG_EFFECTIVE | capng.CAPNG_PERMITTED, |
1048 |
capng.CAP_SETPCAP) |
1049 |
# change uid |
1050 |
capng.capng_change_id(uid.pw_uid, uid.pw_gid, |
1051 |
capng.CAPNG_DROP_SUPP_GRP | \ |
1052 |
capng.CAPNG_CLEAR_BOUNDING) |
1053 |
|
1054 |
logger = logging.getLogger() |
1055 |
if opts.debug: |
1056 |
logger.setLevel(logging.DEBUG) |
1057 |
else: |
1058 |
logger.setLevel(logging.INFO) |
1059 |
|
1060 |
if opts.daemonize: |
1061 |
logfile = os.path.join(config["general"]["logdir"], LOG_FILENAME) |
1062 |
handler = logging.handlers.WatchedFileHandler(logfile) |
1063 |
else: |
1064 |
handler = logging.StreamHandler() |
1065 |
|
1066 |
handler.setFormatter(logging.Formatter(LOG_FORMAT)) |
1067 |
logger.addHandler(handler) |
1068 |
|
1069 |
# Rename this process so 'ps' output looks like |
1070 |
# this is a native executable. |
1071 |
# NOTE: due to a bug in python-setproctitle, one cannot yet |
1072 |
# set individual values for command-line arguments, so only show |
1073 |
# the name of the executable instead. |
1074 |
# setproctitle.setproctitle("\x00".join(sys.argv)) |
1075 |
setproctitle.setproctitle(sys.argv[0]) |
1076 |
|
1077 |
if opts.daemonize: |
1078 |
pidfile = daemon.pidlockfile.TimeoutPIDLockFile( |
1079 |
config["general"]["pidfile"], 10) |
1080 |
# Remove any stale PID files, left behind by previous invocations |
1081 |
if daemon.runner.is_pidfile_stale(pidfile): |
1082 |
logger.warning("Removing stale PID lock file %s", pidfile.path) |
1083 |
pidfile.break_lock() |
1084 |
|
1085 |
d = daemon.DaemonContext(pidfile=pidfile, |
1086 |
umask=0022, |
1087 |
stdout=handler.stream, |
1088 |
stderr=handler.stream, |
1089 |
files_preserve=[handler.stream]) |
1090 |
try: |
1091 |
d.open() |
1092 |
except (daemon.pidlockfile.AlreadyLocked, LockTimeout): |
1093 |
logger.critical("Failed to lock pidfile %s," |
1094 |
" another instance running?", pidfile.path) |
1095 |
sys.exit(1) |
1096 |
|
1097 |
logging.info("Starting up") |
1098 |
logging.info("Running as %s (uid:%d, gid: %d)", |
1099 |
config["general"]["user"], uid.pw_uid, uid.pw_gid) |
1100 |
|
1101 |
proxy_opts = {} |
1102 |
if config["dhcp"].as_bool("enable_dhcp"): |
1103 |
proxy_opts.update({ |
1104 |
"dhcp_queue_num": config["dhcp"].as_int("dhcp_queue"), |
1105 |
"dhcp_lease_lifetime": config["dhcp"].as_int("lease_lifetime"), |
1106 |
"dhcp_lease_renewal": config["dhcp"].as_int("lease_renewal"), |
1107 |
"dhcp_server_ip": config["dhcp"]["server_ip"], |
1108 |
"dhcp_nameservers": config["dhcp"]["nameservers"], |
1109 |
"dhcp_domain": config["dhcp"]["domain"], |
1110 |
}) |
1111 |
|
1112 |
if config["ipv6"].as_bool("enable_ipv6"): |
1113 |
proxy_opts.update({ |
1114 |
"rs_queue_num": config["ipv6"].as_int("rs_queue"), |
1115 |
"ns_queue_num": config["ipv6"].as_int("ns_queue"), |
1116 |
"ra_period": config["ipv6"].as_int("ra_period"), |
1117 |
"ipv6_nameservers": config["ipv6"]["nameservers"], |
1118 |
}) |
1119 |
|
1120 |
# pylint: disable=W0142 |
1121 |
proxy = VMNetProxy(data_path=config["general"]["datapath"], **proxy_opts) |
1122 |
|
1123 |
logging.info("Ready to serve requests") |
1124 |
|
1125 |
|
1126 |
def debug_handler(signum, _): |
1127 |
logging.debug('Received signal %d. Printing proxy state...', signum) |
1128 |
proxy.print_clients() |
1129 |
|
1130 |
# Set the signal handler for debuging clients |
1131 |
signal.signal(signal.SIGUSR1, debug_handler) |
1132 |
signal.siginterrupt(signal.SIGUSR1, False) |
1133 |
|
1134 |
try: |
1135 |
proxy.serve() |
1136 |
except Exception: |
1137 |
if opts.daemonize: |
1138 |
exc = "".join(traceback.format_exception(*sys.exc_info())) |
1139 |
logging.critical(exc) |
1140 |
raise |
1141 |
|
1142 |
|
1143 |
# vim: set ts=4 sts=4 sw=4 et : |