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0fbd7c3c MT |
1 | #!/usr/bin/python |
2 | ############################################################################### | |
3 | # # | |
4 | # IPFire.org - A linux based firewall # | |
5 | # Copyright (C) 2016 Michael Tremer # | |
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 3 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 # | |
18 | # along with this program. If not, see <http://www.gnu.org/licenses/>. # | |
19 | # # | |
20 | ############################################################################### | |
21 | ||
22 | import argparse | |
23 | import datetime | |
24 | import daemon | |
74a5ab67 | 25 | import ipaddress |
0fbd7c3c MT |
26 | import logging |
27 | import logging.handlers | |
28 | import re | |
29 | import signal | |
30 | import subprocess | |
31 | ||
32 | import inotify.adapters | |
33 | ||
077ea717 MT |
34 | LOCAL_TTL = 60 |
35 | ||
0fbd7c3c MT |
36 | def setup_logging(loglevel=logging.INFO): |
37 | log = logging.getLogger("dhcp") | |
38 | log.setLevel(loglevel) | |
39 | ||
40 | handler = logging.handlers.SysLogHandler(address="/dev/log", facility="daemon") | |
41 | handler.setLevel(loglevel) | |
42 | ||
43 | formatter = logging.Formatter("%(name)s[%(process)d]: %(message)s") | |
44 | handler.setFormatter(formatter) | |
45 | ||
46 | log.addHandler(handler) | |
47 | ||
48 | return log | |
49 | ||
50 | log = logging.getLogger("dhcp") | |
51 | ||
e22bcd38 MT |
52 | def ip_address_to_reverse_pointer(address): |
53 | parts = address.split(".") | |
54 | parts.reverse() | |
55 | ||
56 | return "%s.in-addr.arpa" % ".".join(parts) | |
57 | ||
58 | def reverse_pointer_to_ip_address(rr): | |
59 | parts = rr.split(".") | |
60 | ||
61 | # Only take IP address part | |
62 | parts = reversed(parts[0:4]) | |
63 | ||
64 | return ".".join(parts) | |
65 | ||
0fbd7c3c | 66 | class UnboundDHCPLeasesBridge(object): |
7354d294 | 67 | def __init__(self, dhcp_leases_file, fix_leases_file, unbound_leases_file, hosts_file): |
0fbd7c3c | 68 | self.leases_file = dhcp_leases_file |
86c9deb2 | 69 | self.fix_leases_file = fix_leases_file |
7354d294 | 70 | self.hosts_file = hosts_file |
0fbd7c3c MT |
71 | |
72 | self.unbound = UnboundConfigWriter(unbound_leases_file) | |
73 | self.running = False | |
74 | ||
75 | def run(self): | |
76 | log.info("Unbound DHCP Leases Bridge started on %s" % self.leases_file) | |
77 | self.running = True | |
78 | ||
7354d294 MT |
79 | # Initial setup |
80 | self.hosts = self.read_static_hosts() | |
0fbd7c3c MT |
81 | self.update_dhcp_leases() |
82 | ||
7354d294 MT |
83 | i = inotify.adapters.Inotify([ |
84 | self.leases_file, | |
85 | self.fix_leases_file, | |
86 | self.hosts_file, | |
87 | ]) | |
0fbd7c3c MT |
88 | |
89 | for event in i.event_gen(): | |
90 | # End if we are requested to terminate | |
91 | if not self.running: | |
92 | break | |
93 | ||
94 | if event is None: | |
95 | continue | |
96 | ||
97 | header, type_names, watch_path, filename = event | |
98 | ||
99 | # Update leases after leases file has been modified | |
100 | if "IN_MODIFY" in type_names: | |
7354d294 MT |
101 | # Reload hosts |
102 | if watch_path == self.hosts_file: | |
103 | self.hosts = self.read_static_hosts() | |
104 | ||
0fbd7c3c MT |
105 | self.update_dhcp_leases() |
106 | ||
86c9deb2 MT |
107 | # If the file is deleted, we re-add the watcher |
108 | if "IN_IGNORED" in type_names: | |
109 | i.add_watch(watch_path) | |
110 | ||
0fbd7c3c MT |
111 | log.info("Unbound DHCP Leases Bridge terminated") |
112 | ||
113 | def update_dhcp_leases(self): | |
86c9deb2 MT |
114 | leases = [] |
115 | ||
116 | for lease in DHCPLeases(self.leases_file): | |
5d4f3a42 MT |
117 | # Don't bother with any leases that don't have a hostname |
118 | if not lease.fqdn: | |
119 | continue | |
120 | ||
86c9deb2 MT |
121 | leases.append(lease) |
122 | ||
123 | for lease in FixLeases(self.fix_leases_file): | |
124 | leases.append(lease) | |
0fbd7c3c | 125 | |
c7b83f9b MT |
126 | # Skip any leases that also are a static host |
127 | leases = [l for l in leases if not l.fqdn in self.hosts] | |
128 | ||
129 | # Remove any inactive or expired leases | |
130 | leases = [l for l in leases if l.active and not l.expired] | |
131 | ||
132 | # Dump leases | |
133 | if leases: | |
134 | log.debug("DHCP Leases:") | |
135 | for lease in leases: | |
136 | log.debug(" %s:" % lease.fqdn) | |
137 | log.debug(" State: %s" % lease.binding_state) | |
138 | log.debug(" Start: %s" % lease.time_starts) | |
139 | log.debug(" End : %s" % lease.time_ends) | |
140 | if lease.expired: | |
141 | log.debug(" Expired") | |
142 | ||
0fbd7c3c MT |
143 | self.unbound.update_dhcp_leases(leases) |
144 | ||
7354d294 MT |
145 | def read_static_hosts(self): |
146 | log.info("Reading static hosts from %s" % self.hosts_file) | |
147 | ||
148 | hosts = {} | |
149 | with open(self.hosts_file) as f: | |
150 | for line in f.readlines(): | |
151 | line = line.rstrip() | |
152 | ||
153 | try: | |
154 | enabled, ipaddr, hostname, domainname = line.split(",") | |
155 | except: | |
156 | log.warning("Could not parse line: %s" % line) | |
157 | continue | |
158 | ||
159 | # Skip any disabled entries | |
160 | if not enabled == "on": | |
161 | continue | |
162 | ||
163 | if hostname and domainname: | |
164 | fqdn = "%s.%s" % (hostname, domainname) | |
165 | elif hostname: | |
166 | fqdn = hostname | |
167 | elif domainname: | |
168 | fqdn = domainname | |
169 | ||
170 | try: | |
171 | hosts[fqdn].append(ipaddr) | |
172 | hosts[fqdn].sort() | |
173 | except KeyError: | |
174 | hosts[fqdn] = [ipaddr,] | |
175 | ||
176 | # Dump everything in the logs | |
177 | log.debug("Static hosts:") | |
178 | for hostname, addresses in hosts.items(): | |
179 | log.debug(" %-20s : %s" % (hostname, ", ".join(addresses))) | |
180 | ||
181 | return hosts | |
182 | ||
0fbd7c3c MT |
183 | def terminate(self): |
184 | self.running = False | |
185 | ||
186 | ||
187 | class DHCPLeases(object): | |
188 | regex_leaseblock = re.compile(r"lease (?P<ipaddr>\d+\.\d+\.\d+\.\d+) {(?P<config>[\s\S]+?)\n}") | |
189 | ||
190 | def __init__(self, path): | |
191 | self.path = path | |
192 | ||
193 | self._leases = self._parse() | |
194 | ||
195 | def __iter__(self): | |
196 | return iter(self._leases) | |
197 | ||
198 | def _parse(self): | |
86c9deb2 MT |
199 | log.info("Reading DHCP leases from %s" % self.path) |
200 | ||
0fbd7c3c MT |
201 | leases = [] |
202 | ||
203 | with open(self.path) as f: | |
204 | # Read entire leases file | |
205 | data = f.read() | |
206 | ||
207 | for match in self.regex_leaseblock.finditer(data): | |
208 | block = match.groupdict() | |
209 | ||
210 | ipaddr = block.get("ipaddr") | |
211 | config = block.get("config") | |
212 | ||
213 | properties = self._parse_block(config) | |
214 | ||
215 | # Skip any abandoned leases | |
216 | if not "hardware" in properties: | |
217 | continue | |
218 | ||
219 | lease = Lease(ipaddr, properties) | |
220 | ||
221 | # Check if a lease for this Ethernet address already | |
222 | # exists in the list of known leases. If so replace | |
223 | # if with the most recent lease | |
224 | for i, l in enumerate(leases): | |
225 | if l.hwaddr == lease.hwaddr: | |
226 | leases[i] = max(lease, l) | |
227 | break | |
228 | ||
229 | else: | |
230 | leases.append(lease) | |
231 | ||
232 | return leases | |
233 | ||
234 | def _parse_block(self, block): | |
235 | properties = {} | |
236 | ||
237 | for line in block.splitlines(): | |
238 | if not line: | |
239 | continue | |
240 | ||
241 | # Remove trailing ; from line | |
242 | if line.endswith(";"): | |
243 | line = line[:-1] | |
244 | ||
245 | # Invalid line if it doesn't end with ; | |
246 | else: | |
247 | continue | |
248 | ||
249 | # Remove any leading whitespace | |
250 | line = line.lstrip() | |
251 | ||
252 | # We skip all options and sets | |
253 | if line.startswith("option") or line.startswith("set"): | |
254 | continue | |
255 | ||
256 | # Split by first space | |
257 | key, val = line.split(" ", 1) | |
258 | properties[key] = val | |
259 | ||
260 | return properties | |
261 | ||
262 | ||
86c9deb2 MT |
263 | class FixLeases(object): |
264 | cache = {} | |
265 | ||
266 | def __init__(self, path): | |
267 | self.path = path | |
268 | ||
269 | self._leases = self.cache[self.path] = self._parse() | |
270 | ||
271 | def __iter__(self): | |
272 | return iter(self._leases) | |
273 | ||
274 | def _parse(self): | |
275 | log.info("Reading fix leases from %s" % self.path) | |
276 | ||
277 | leases = [] | |
278 | now = datetime.datetime.utcnow() | |
279 | ||
280 | with open(self.path) as f: | |
281 | for line in f.readlines(): | |
282 | line = line.rstrip() | |
283 | ||
284 | try: | |
285 | hwaddr, ipaddr, enabled, a, b, c, hostname = line.split(",") | |
286 | except ValueError: | |
287 | log.warning("Could not parse line: %s" % line) | |
288 | continue | |
289 | ||
290 | # Skip any disabled leases | |
291 | if not enabled == "on": | |
292 | continue | |
293 | ||
294 | l = Lease(ipaddr, { | |
295 | "binding" : "state active", | |
296 | "client-hostname" : hostname, | |
297 | "hardware" : "ethernet %s" % hwaddr, | |
298 | "starts" : now.strftime("%w %Y/%m/%d %H:%M:%S"), | |
299 | "ends" : "never", | |
300 | }) | |
301 | leases.append(l) | |
302 | ||
303 | # Try finding any deleted leases | |
304 | for lease in self.cache.get(self.path, []): | |
305 | if lease in leases: | |
306 | continue | |
307 | ||
308 | # Free the deleted lease | |
309 | lease.free() | |
310 | leases.append(lease) | |
311 | ||
312 | return leases | |
313 | ||
314 | ||
0fbd7c3c MT |
315 | class Lease(object): |
316 | def __init__(self, ipaddr, properties): | |
317 | self.ipaddr = ipaddr | |
318 | self._properties = properties | |
319 | ||
320 | def __repr__(self): | |
321 | return "<%s %s for %s (%s)>" % (self.__class__.__name__, | |
322 | self.ipaddr, self.hwaddr, self.hostname) | |
323 | ||
324 | def __eq__(self, other): | |
325 | return self.ipaddr == other.ipaddr and self.hwaddr == other.hwaddr | |
326 | ||
327 | def __gt__(self, other): | |
328 | if not self.ipaddr == other.ipaddr: | |
329 | return | |
330 | ||
331 | if not self.hwaddr == other.hwaddr: | |
332 | return | |
333 | ||
334 | return self.time_starts > other.time_starts | |
335 | ||
336 | @property | |
337 | def binding_state(self): | |
338 | state = self._properties.get("binding") | |
339 | ||
340 | if state: | |
341 | state = state.split(" ", 1) | |
342 | return state[1] | |
343 | ||
86c9deb2 MT |
344 | def free(self): |
345 | self._properties.update({ | |
346 | "binding" : "state free", | |
347 | }) | |
348 | ||
0fbd7c3c MT |
349 | @property |
350 | def active(self): | |
351 | return self.binding_state == "active" | |
352 | ||
353 | @property | |
354 | def hwaddr(self): | |
355 | hardware = self._properties.get("hardware") | |
356 | ||
357 | if not hardware: | |
358 | return | |
359 | ||
360 | ethernet, address = hardware.split(" ", 1) | |
361 | ||
362 | return address | |
363 | ||
364 | @property | |
365 | def hostname(self): | |
366 | hostname = self._properties.get("client-hostname") | |
367 | ||
998e880b MT |
368 | if hostname is None: |
369 | return | |
370 | ||
0fbd7c3c | 371 | # Remove any "" |
998e880b | 372 | hostname = hostname.replace("\"", "") |
0fbd7c3c | 373 | |
998e880b MT |
374 | # Only return valid hostnames |
375 | m = re.match(r"^[A-Z0-9\-]{1,63}$", hostname, re.I) | |
376 | if m: | |
377 | return hostname | |
0fbd7c3c MT |
378 | |
379 | @property | |
380 | def domain(self): | |
74a5ab67 MT |
381 | # Load ethernet settings |
382 | ethernet_settings = self.read_settings("/var/ipfire/ethernet/settings") | |
383 | ||
384 | # Load DHCP settings | |
385 | dhcp_settings = self.read_settings("/var/ipfire/dhcp/settings") | |
386 | ||
387 | subnets = {} | |
388 | for zone in ("GREEN", "BLUE"): | |
389 | if not dhcp_settings.get("ENABLE_%s" % zone) == "on": | |
390 | continue | |
391 | ||
392 | netaddr = ethernet_settings.get("%s_NETADDRESS" % zone) | |
393 | submask = ethernet_settings.get("%s_NETMASK" % zone) | |
394 | ||
395 | subnet = ipaddress.ip_network("%s/%s" % (netaddr, submask)) | |
396 | domain = dhcp_settings.get("DOMAIN_NAME_%s" % zone) | |
397 | ||
398 | subnets[subnet] = domain | |
399 | ||
400 | address = ipaddress.ip_address(self.ipaddr) | |
401 | ||
402 | for subnet, domain in subnets.items(): | |
403 | if address in subnet: | |
404 | return domain | |
405 | ||
406 | # Fall back to localdomain if no match could be found | |
407 | return "localdomain" | |
408 | ||
409 | @staticmethod | |
410 | def read_settings(filename): | |
411 | settings = {} | |
412 | ||
413 | with open(filename) as f: | |
414 | for line in f.readlines(): | |
415 | # Remove line-breaks | |
416 | line = line.rstrip() | |
417 | ||
418 | k, v = line.split("=", 1) | |
419 | settings[k] = v | |
420 | ||
421 | return settings | |
0fbd7c3c MT |
422 | |
423 | @property | |
424 | def fqdn(self): | |
998e880b MT |
425 | if self.hostname: |
426 | return "%s.%s" % (self.hostname, self.domain) | |
0fbd7c3c MT |
427 | |
428 | @staticmethod | |
429 | def _parse_time(s): | |
430 | return datetime.datetime.strptime(s, "%w %Y/%m/%d %H:%M:%S") | |
431 | ||
432 | @property | |
433 | def time_starts(self): | |
434 | starts = self._properties.get("starts") | |
435 | ||
436 | if starts: | |
437 | return self._parse_time(starts) | |
438 | ||
439 | @property | |
440 | def time_ends(self): | |
441 | ends = self._properties.get("ends") | |
442 | ||
443 | if not ends or ends == "never": | |
444 | return | |
445 | ||
446 | return self._parse_time(ends) | |
447 | ||
448 | @property | |
449 | def expired(self): | |
450 | if not self.time_ends: | |
451 | return self.time_starts > datetime.datetime.utcnow() | |
452 | ||
453 | return self.time_starts > datetime.datetime.utcnow() > self.time_ends | |
454 | ||
455 | @property | |
456 | def rrset(self): | |
998e880b MT |
457 | # If the lease does not have a valid FQDN, we cannot create any RRs |
458 | if self.fqdn is None: | |
459 | return [] | |
460 | ||
0fbd7c3c MT |
461 | return [ |
462 | # Forward record | |
b8dd42b9 | 463 | (self.fqdn, "%s" % LOCAL_TTL, "IN A", self.ipaddr), |
0fbd7c3c MT |
464 | |
465 | # Reverse record | |
e22bcd38 MT |
466 | (ip_address_to_reverse_pointer(self.ipaddr), "%s" % LOCAL_TTL, |
467 | "IN PTR", self.fqdn), | |
0fbd7c3c MT |
468 | ] |
469 | ||
470 | ||
471 | class UnboundConfigWriter(object): | |
472 | def __init__(self, path): | |
473 | self.path = path | |
474 | ||
c7b83f9b | 475 | self._cached_leases = [] |
0fbd7c3c MT |
476 | |
477 | def update_dhcp_leases(self, leases): | |
d20ef9d7 MT |
478 | # Find any leases that have expired or do not exist any more |
479 | # but are still in the unbound local data | |
c7b83f9b | 480 | removed_leases = [l for l in self._cached_leases if not l in leases] |
d20ef9d7 | 481 | |
0fbd7c3c | 482 | # Find any leases that have been added |
c7b83f9b | 483 | new_leases = [l for l in leases if l not in self._cached_leases] |
0fbd7c3c MT |
484 | |
485 | # End here if nothing has changed | |
486 | if not new_leases and not removed_leases: | |
487 | return | |
488 | ||
0fbd7c3c MT |
489 | # Write out all leases |
490 | self.write_dhcp_leases(leases) | |
491 | ||
492 | # Update unbound about changes | |
c7b83f9b | 493 | for l in removed_leases: |
3ec5ba50 MT |
494 | try: |
495 | for name, ttl, type, content in l.rrset: | |
496 | log.debug("Removing records for %s" % name) | |
497 | self._control("local_data_remove", name) | |
498 | ||
499 | # If the lease cannot be removed we will try the next one | |
500 | except: | |
501 | continue | |
502 | ||
503 | # If the removal was successful, we will remove it from the cache | |
504 | else: | |
505 | self._cached_leases.remove(l) | |
0fbd7c3c MT |
506 | |
507 | for l in new_leases: | |
3ec5ba50 MT |
508 | try: |
509 | for rr in l.rrset: | |
510 | log.debug("Adding new record %s" % " ".join(rr)) | |
511 | self._control("local_data", *rr) | |
0fbd7c3c | 512 | |
3ec5ba50 MT |
513 | # If the lease cannot be added we will try the next one |
514 | except: | |
515 | continue | |
516 | ||
517 | # Add lease to cache when successfully added | |
518 | else: | |
519 | self._cached_leases.append(l) | |
0fbd7c3c MT |
520 | |
521 | def write_dhcp_leases(self, leases): | |
522 | with open(self.path, "w") as f: | |
523 | for l in leases: | |
524 | for rr in l.rrset: | |
525 | f.write("local-data: \"%s\"\n" % " ".join(rr)) | |
526 | ||
527 | def _control(self, *args): | |
b8dd42b9 | 528 | command = ["unbound-control"] |
0fbd7c3c MT |
529 | command.extend(args) |
530 | ||
531 | try: | |
3ec5ba50 | 532 | subprocess.check_output(command) |
0fbd7c3c MT |
533 | |
534 | # Log any errors | |
535 | except subprocess.CalledProcessError as e: | |
536 | log.critical("Could not run %s, error code: %s: %s" % ( | |
537 | " ".join(command), e.returncode, e.output)) | |
538 | ||
3ec5ba50 MT |
539 | raise |
540 | ||
0fbd7c3c MT |
541 | |
542 | if __name__ == "__main__": | |
543 | parser = argparse.ArgumentParser(description="Bridge for DHCP Leases and Unbound DNS") | |
544 | ||
545 | # Daemon Stuff | |
546 | parser.add_argument("--daemon", "-d", action="store_true", | |
547 | help="Launch as daemon in background") | |
548 | parser.add_argument("--verbose", "-v", action="count", help="Be more verbose") | |
549 | ||
550 | # Paths | |
551 | parser.add_argument("--dhcp-leases", default="/var/state/dhcp/dhcpd.leases", | |
552 | metavar="PATH", help="Path to the DHCPd leases file") | |
553 | parser.add_argument("--unbound-leases", default="/etc/unbound/dhcp-leases.conf", | |
554 | metavar="PATH", help="Path to the unbound configuration file") | |
86c9deb2 MT |
555 | parser.add_argument("--fix-leases", default="/var/ipfire/dhcp/fixleases", |
556 | metavar="PATH", help="Path to the fix leases file") | |
7354d294 MT |
557 | parser.add_argument("--hosts", default="/var/ipfire/main/hosts", |
558 | metavar="PATH", help="Path to static hosts file") | |
0fbd7c3c MT |
559 | |
560 | # Parse command line arguments | |
561 | args = parser.parse_args() | |
562 | ||
563 | # Setup logging | |
564 | if args.verbose == 1: | |
565 | loglevel = logging.INFO | |
566 | elif args.verbose >= 2: | |
567 | loglevel = logging.DEBUG | |
568 | else: | |
569 | loglevel = logging.WARN | |
570 | ||
571 | setup_logging(loglevel) | |
572 | ||
7354d294 MT |
573 | bridge = UnboundDHCPLeasesBridge(args.dhcp_leases, args.fix_leases, |
574 | args.unbound_leases, args.hosts) | |
0fbd7c3c MT |
575 | |
576 | ctx = daemon.DaemonContext(detach_process=args.daemon) | |
577 | ctx.signal_map = { | |
578 | signal.SIGHUP : bridge.update_dhcp_leases, | |
579 | signal.SIGTERM : bridge.terminate, | |
580 | } | |
581 | ||
582 | with ctx: | |
583 | bridge.run() |