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