import argparse
import datetime
import daemon
+import filecmp
+import functools
import ipaddress
import logging
import logging.handlers
import signal
import stat
import subprocess
+import sys
import tempfile
+import time
import inotify.adapters
LOCAL_TTL = 60
-def setup_logging(loglevel=logging.INFO):
- log = logging.getLogger("dhcp")
+log = logging.getLogger("dhcp")
+log.setLevel(logging.DEBUG)
+
+def setup_logging(daemon=True, loglevel=logging.INFO):
log.setLevel(loglevel)
+ # Log to syslog by default
handler = logging.handlers.SysLogHandler(address="/dev/log", facility="daemon")
- handler.setLevel(loglevel)
+ log.addHandler(handler)
+ # Format everything
formatter = logging.Formatter("%(name)s[%(process)d]: %(message)s")
handler.setFormatter(formatter)
- log.addHandler(handler)
+ handler.setLevel(loglevel)
- return log
+ # If we are running in foreground, we should write everything to the console, too
+ if not daemon:
+ handler = logging.StreamHandler()
+ log.addHandler(handler)
-log = logging.getLogger("dhcp")
+ handler.setLevel(loglevel)
+
+ return log
def ip_address_to_reverse_pointer(address):
parts = address.split(".")
self.fix_leases_file = fix_leases_file
self.hosts_file = hosts_file
+ self.watches = {
+ self.leases_file : inotify.constants.IN_MODIFY,
+ self.fix_leases_file : 0,
+ self.hosts_file : 0,
+ }
+
self.unbound = UnboundConfigWriter(unbound_leases_file)
self.running = False
log.info("Unbound DHCP Leases Bridge started on %s" % self.leases_file)
self.running = True
- # Initial setup
- self.hosts = self.read_static_hosts()
- self.update_dhcp_leases()
+ i = inotify.adapters.Inotify()
- i = inotify.adapters.Inotify([
- self.leases_file,
- self.fix_leases_file,
- self.hosts_file,
- ])
+ # Add watches for the directories of every relevant file
+ for f, mask in self.watches.items():
+ i.add_watch(
+ os.path.dirname(f),
+ mask | inotify.constants.IN_CLOSE_WRITE | inotify.constants.IN_MOVED_TO,
+ )
- for event in i.event_gen():
- # End if we are requested to terminate
- if not self.running:
- break
+ # Enabled so that we update hosts and leases on startup
+ update_hosts = update_leases = True
- if event is None:
- continue
+ while self.running:
+ log.debug("Wakeup of main loop")
+
+ # Process the entire inotify queue and identify what we need to do
+ for event in i.event_gen():
+ # Nothing to do
+ if event is None:
+ break
+
+ # Decode the event
+ header, type_names, path, filename = event
+
+ file = os.path.join(path, filename)
- header, type_names, watch_path, filename = event
+ log.debug("inotify event received for %s: %s", file, " ".join(type_names))
- # Update leases after leases file has been modified
- if "IN_MODIFY" in type_names:
- # Reload hosts
- if watch_path == self.hosts_file:
- self.hosts = self.read_static_hosts()
+ # Did the hosts file change?
+ if self.hosts_file == file:
+ update_hosts = True
+ # We will need to update the leases on any change
+ update_leases = True
+
+ # Update hosts (if needed)
+ if update_hosts:
+ self.hosts = self.read_static_hosts()
+
+ # Update leases (if needed)
+ if update_leases:
self.update_dhcp_leases()
- # If the file is deleted, we re-add the watcher
- if "IN_IGNORED" in type_names:
- i.add_watch(watch_path)
+ # Reset
+ update_hosts = update_leases = False
+
+ # Wait a moment before we start the next iteration
+ time.sleep(5)
log.info("Unbound DHCP Leases Bridge terminated")
if address in subnet:
return subnets[subnet]
- # Fall back to localdomain if no match could be found
- return "localdomain"
+ # Load main settings
+ settings = self.read_settings("/var/ipfire/main/settings")
+
+ # Fall back to the host domain if no match could be found
+ return settings.get("DOMAINNAME", "localdomain")
@staticmethod
+ @functools.cache
def read_settings(filename):
settings = {}
def __init__(self, path):
self.path = path
- self._cached_leases = []
-
def update_dhcp_leases(self, leases):
- # Find any leases that have expired or do not exist any more
- # but are still in the unbound local data
- removed_leases = [l for l in self._cached_leases if not l in leases]
-
- # Find any leases that have been added
- new_leases = [l for l in leases if l not in self._cached_leases]
-
- # End here if nothing has changed
- if not new_leases and not removed_leases:
- return
-
# Write out all leases
- self.write_dhcp_leases(leases)
-
- # Update unbound about changes
- for l in removed_leases:
- try:
- for name, ttl, type, content in l.rrset:
- log.debug("Removing records for %s" % name)
- self._control("local_data_remove", name)
+ if self.write_dhcp_leases(leases):
+ log.debug("Reloading Unbound...")
- # If the lease cannot be removed we will try the next one
- except:
- continue
+ # Reload the configuration without dropping the cache
+ self._control("reload_keep_cache")
- # If the removal was successful, we will remove it from the cache
- else:
- self._cached_leases.remove(l)
+ def write_dhcp_leases(self, leases):
+ log.debug("Writing DHCP leases...")
- for l in new_leases:
- try:
+ with tempfile.NamedTemporaryFile(mode="w") as f:
+ for l in sorted(leases, key=lambda x: x.ipaddr):
for rr in l.rrset:
- log.debug("Adding new record %s" % " ".join(rr))
- self._control("local_data", *rr)
+ f.write("local-data: \"%s\"\n" % " ".join(rr))
- # If the lease cannot be added we will try the next one
- except:
- continue
+ # Flush the file
+ f.flush()
- # Add lease to cache when successfully added
- else:
- self._cached_leases.append(l)
+ # Compare if the new leases file has changed from the previous version
+ try:
+ if filecmp.cmp(f.name, self.path, shallow=False):
+ log.debug("The generated leases file has not changed")
- def write_dhcp_leases(self, leases):
- with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
- filename = f.name
+ return False
- for l in leases:
- for rr in l.rrset:
- f.write("local-data: \"%s\"\n" % " ".join(rr))
+ # Remove the old file
+ os.unlink(self.path)
+
+ # If the previous file did not exist, just keep falling through
+ except FileNotFoundError:
+ pass
# Make file readable for everyone
os.fchmod(f.fileno(), stat.S_IRUSR|stat.S_IWUSR|stat.S_IRGRP|stat.S_IROTH)
- os.rename(filename, self.path)
+ # Move the file to its destination
+ os.link(f.name, self.path)
+
+ return True
def _control(self, *args):
command = ["unbound-control"]
log.critical("Could not run %s, error code: %s: %s" % (
" ".join(command), e.returncode, e.output))
- raise
+ raise e
if __name__ == "__main__":
elif args.verbose >= 2:
loglevel = logging.DEBUG
- setup_logging(loglevel)
-
bridge = UnboundDHCPLeasesBridge(args.dhcp_leases, args.fix_leases,
args.unbound_leases, args.hosts)
- ctx = daemon.DaemonContext(detach_process=args.daemon)
- ctx.signal_map = {
- signal.SIGHUP : bridge.update_dhcp_leases,
- signal.SIGTERM : bridge.terminate,
- }
+ with daemon.DaemonContext(
+ detach_process=args.daemon,
+ stderr=None if args.daemon else sys.stderr,
+ signal_map = {
+ signal.SIGHUP : bridge.update_dhcp_leases,
+ signal.SIGTERM : bridge.terminate,
+ },
+ ) as daemon:
+ setup_logging(daemon=args.daemon, loglevel=loglevel)
- with ctx:
bridge.run()
projects / ipfire-2.x.git / blobdiff