terom@15: #!/usr/bin/env python
terom@15: 
terom@15: """
terom@15:     Monitor DHCP use.
terom@15: """
terom@15: 
terom@15: __version__ = '0.0'
terom@15: 
terom@15: import pvl.args
terom@15: import pvl.syslog.args
terom@15: 
terom@15: import pvl.verkko.db as db
terom@15: import pvl.syslog.dhcp
terom@17: import pvl.verkko.dhcp.leases
terom@15: 
terom@15: import logging, optparse
terom@15: 
terom@15: log = logging.getLogger('main')
terom@15: 
terom@15: # name of process in syslog
terom@15: DHCP_SYSLOG_PROG = 'dhcpd'
terom@15: 
terom@15: def parse_options (argv) :
terom@15:     """
terom@15:         Parse command-line arguments.
terom@15:     """
terom@15: 
terom@15:     prog = argv[0]
terom@15: 
terom@15:     parser = optparse.OptionParser(
terom@15:             prog        = prog,
terom@15:             usage       = '%prog: [options]',
terom@15:             version     = __version__,
terom@15: 
terom@15:             # module docstring
terom@15:             description = __doc__,
terom@15:     )
terom@15:     
terom@15:     # options
terom@15:     parser.add_option_group(pvl.args.parser(parser))
terom@15: 
terom@15:     ## syslog
terom@15:     parser.add_option_group(pvl.syslog.args.parser(parser, prog=DHCP_SYSLOG_PROG))
terom@15: 
terom@17:     ## leases
terom@17:     parser.add_option('--leases-file',          metavar='FILE',
terom@17:             help="Synchronize dhcpd leases from given file")
terom@17: 
terom@17:     parser.add_option('--leases-tail',          type='float', metavar='POLL',
terom@17:             help="Continuously poll leases file XXX: overrides --syslog-tail")
terom@17: 
terom@17: 
terom@15:     ## XXX: networks
terom@15:     parser.add_option('--network',              metavar='NET', action='append',
terom@15:             help="Filter leases by network prefix as plugin instance")
terom@15: 
terom@15:     parser.add_option('--gateway',              metavar='GW/IFACE', action='append',
terom@15:             help="Filter messages by gateway/interface as plugin instance")
terom@15: 
terom@15:     ## hosts
terom@15:     parser.add_option('--database',             metavar='URI',
terom@15:             help="Track hosts in given database")
terom@15: 
terom@15:     parser.add_option('--create',               action='store_true',
terom@15:             help="Initialize database")
terom@15: 
terom@15:     # defaults
terom@15:     parser.set_defaults(
terom@15: 
terom@15:     )
terom@15:     
terom@15:     # parse
terom@15:     options, args = parser.parse_args(argv[1:])
terom@15:     
terom@15:     # apply
terom@15:     pvl.args.apply(options, prog)
terom@15: 
terom@15:     if not options.database :
terom@15:         parser.error("Missing required option: --database")
terom@15: 
terom@15:     return options, args
terom@15: 
terom@17: class DHCPHostsDatabase (object) :
terom@17:     """
terom@17:         The dhcp_hosts table in our database.
terom@17:     """
terom@17: 
terom@17:     def __init__ (self, db) :
terom@17:         self.db = db
terom@15: 
terom@15:     def create (self) :
terom@15:         """
terom@15:             CREATE TABLEs
terom@15:         """
terom@15: 
terom@15:         log.info("Creating database tables: dhcp_hosts")
terom@33:         db.dhcp_hosts.create(self.db.engine, checkfirst=True)
terom@15: 
terom@15:     def insert (self, attrs) :
terom@15:         """
terom@15:             INSERT new host
terom@15:         """
terom@15: 
terom@15:         query = db.dhcp_hosts.insert().values(
terom@15:                 ip          = attrs['ip'],
terom@15:                 mac         = attrs['mac'],
terom@15:                 gw          = attrs['gw'],
terom@15: 
terom@15:                 first_seen  = attrs['timestamp'],
terom@16:                 count       = 1,
terom@15: 
terom@15:                 last_seen   = attrs['timestamp'],
terom@16:                 state       = attrs['state'],
terom@16:                 
terom@16:                 name        = attrs.get('name'),
terom@16:                 error       = attrs.get('error'),
terom@15:         )
terom@15:         
terom@17:         # -> id
terom@17:         return self.db.insert(query)
terom@15: 
terom@15:     def update (self, attrs) :
terom@15:         """
terom@15:             UPDATE existing host, or return False if not found.
terom@15:         """
terom@15: 
terom@15:         table = db.dhcp_hosts
terom@15: 
terom@16:         query = table.update()
terom@16:         query = query.where((table.c.ip == attrs['ip']) & (table.c.mac == attrs['mac']) & (table.c.gw == attrs['gw']))
terom@16:         query = query.values(
terom@16:                 count       = db.func.coalesce(table.c.count, 0) + 1,
terom@15: 
terom@15:                 # set
terom@15:                 last_seen   = attrs['timestamp'],
terom@16:                 state       = attrs['state'],
terom@15:         )
terom@16:         
terom@16:         if 'name' in attrs :
terom@16:             query = query.values(name = attrs['name'])
terom@16:         
terom@16:         if 'error' in attrs :
terom@16:             query = query.values(error = attrs['error'])
terom@16: 
terom@15:         # any matched rows?
terom@17:         return self.db.update(query)
terom@15: 
terom@15:     def process (self, item) :
terom@15:         """
terom@15:             Process given DHCP syslog message to update the hosts table.
terom@15:         """
terom@16: 
terom@16:         attrs = {}
terom@15:         
terom@15:         # ignore unless we have enough info to fully identify the client
terom@15:         # this means that we omit DHCPDISCOVER messages, but we get the OFFER/REQUEST/ACK
terom@15:         if any(name not in item for name in ('lease', 'hwaddr', 'gateway')) :
terom@15:             # ignore; we require these
terom@15:             return
terom@15: 
terom@16:         # do not override error from request on NAK; clear otherwise
terom@16:         if item.get('type') == 'DHCPNAK' :
terom@16:             pass
terom@16:         else :
terom@16:             attrs['error'] = item.get('error')
terom@16: 
terom@16:         # do not override name unless known
terom@16:         if item.get('name') :
terom@16:             attrs['name'] = item.get('name')
terom@16: 
terom@15:         # db: syslog
terom@15:         ATTR_MAP = (
terom@15:             ('ip',          'lease'),
terom@15:             ('mac',         'hwaddr'),
terom@15:             ('gw',          'gateway'),
terom@15: 
terom@15:             ('timestamp',   'timestamp'),
terom@15:             ('state',       'type'),
terom@15:         )
terom@15: 
terom@16:         # generic attrs
terom@16:         for key, name in ATTR_MAP :
terom@16:             attrs[key] = item.get(name)
terom@15: 
terom@15:         # update existing?
terom@15:         if self.update(attrs) :
terom@15:             log.info("Update: %s", attrs)
terom@15: 
terom@15:         else :
terom@15:             # new
terom@15:             log.info("Insert: %s", attrs)
terom@15:             self.insert(attrs)
terom@15: 
terom@17: class DHCPLeasesDatabase (object) :
terom@17:     def __init__ (self, db) :
terom@17:         self.db = db
terom@17: 
terom@17:     def create (self) :
terom@17:         """
terom@17:             CREATE TABLEs
terom@17:         """
terom@17: 
terom@17:         log.info("Creating database tables: dhcp_leases")
terom@33:         db.dhcp_leases.create(self.db.engine, checkfirst=True)
terom@17: 
terom@17:     def update (self, lease) :
terom@17:         """
terom@17:             Try an extend an existing lease?
terom@17:         """
terom@17: 
terom@17:         c = db.dhcp_leases.c
terom@17: 
terom@17:         ip = lease['lease']
terom@17:         mac = lease.get('hwaddr')
terom@17:         starts = lease['starts']
terom@38:         ends = lease.get('ends')
terom@17: 
terom@17:         update = db.dhcp_leases.update()
terom@17:         
terom@38:         # XXX: if ends is None?
terom@17:         if mac :
terom@17:             # renew lease..?
terom@17:             update = update.where((c.ip == ip) & (c.mac == mac) & ((starts < c.ends) | (c.ends == None)))
terom@17:         else :
terom@17:             # new state for lease..?
terom@17:             update = update.where((c.ip == ip) & ((starts < c.ends) | (c.ends == ends)))
terom@17: 
terom@17:         update = update.values(
terom@17:                 state       = lease['binding-state'],
terom@17:                 next        = lease.get('next-binding-state'),
terom@38:                 ends        = ends,
terom@17:         )
terom@17: 
terom@17:         if lease.get('client-hostname') :
terom@17:             update = update.values(hostname = lease['client-hostname'])
terom@17: 
terom@17:         return self.db.update(update) > 0
terom@17: 
terom@17:     def insert (self, lease) :
terom@17:         """
terom@17:             Record a new lease.
terom@17:         """
terom@17: 
terom@17:         c = db.dhcp_leases.c
terom@17: 
terom@17:         query = db.dhcp_leases.insert().values(
terom@17:             ip          = lease['lease'],
terom@17:             mac         = lease['hwaddr'],
terom@17:             hostname    = lease.get('client-hostname'),
terom@17: 
terom@17:             starts      = lease['starts'],
terom@38:             ends        = lease.get('ends'),
terom@17: 
terom@17:             state       = lease['binding-state'],
terom@17:             next        = lease.get('next-binding-state'),
terom@17:         )
terom@17: 
terom@17:         return self.db.insert(query)
terom@17: 
terom@17:     def process (self, lease) :
terom@17:         """
terom@17:             Process given DHCP lease to update currently active lease, or insert a new one.
terom@17:         """
terom@17: 
terom@17:         # update existing?
terom@17:         if self.update(lease) :
terom@17:             log.info("Update: %s", lease)
terom@17: 
terom@17:         elif lease.get('hwaddr') :
terom@17:             # new
terom@17:             id = self.insert(lease)
terom@17: 
terom@17:             log.info("Insert: %s -> %d", lease, id)
terom@17: 
terom@17:         else :
terom@17:             # may be a free lease
terom@17:             log.warn("Ignored lease: %s", lease)
terom@17: 
terom@34: # XXX: mainloop
terom@34: import time
terom@34: 
terom@17: class DHCPHandler (object) :
terom@15:     """
terom@15:         Process lines from syslog
terom@15:     """
terom@15: 
terom@17:     def __init__ (self, db, syslog, leases) :
terom@15:         self.db = db
terom@15: 
terom@17:         self.syslog = syslog
terom@17:         self.leases = leases
terom@17: 
terom@17:         self.hostdb = DHCPHostsDatabase(db)
terom@17:         self.leasedb = DHCPLeasesDatabase(db)
terom@17: 
terom@15:         # XXX
terom@15:         self.filter = pvl.syslog.dhcp.DHCPSyslogFilter()
terom@15: 
terom@17:     def createdb (self) :
terom@17:         """
terom@17:             Initialize database tables.
terom@17:         """
terom@17: 
terom@17:         self.hostdb.create()
terom@17:         self.leasedb.create()
terom@17: 
terom@17:     def process_syslog (self, item) :
terom@15:         """
terom@15:             Handle a single item read from syslog to DB.
terom@15:         """
terom@15: 
terom@15:         dhcp_item = self.filter.parse(item['msg'])
terom@77: 
terom@77:         log.debug("%s: %s", item, dhcp_item)
terom@15:         
terom@15:         if not dhcp_item :
terom@15:             # ignore
terom@15:             return
terom@15: 
terom@15:         dhcp_item['timestamp'] = item['timestamp'] # XXX: fixup DHCPSyslogParser?
terom@15: 
terom@16:         if item.get('error') :
terom@16:             item['error'] = self.filter.parse_error(item['error'])
terom@16: 
terom@17:         self.hostdb.process(dhcp_item)
terom@15: 
terom@17:     def process_leases (self, leases) :
terom@17:         """
terom@17:             Handle given changed lease.
terom@17:         """
terom@17:         
terom@17:         for lease in leases :
terom@17:             log.info("%s", lease['lease'])
terom@17: 
terom@17:             self.leasedb.process(lease)
terom@17: 
terom@17:     def sync_leases (self, leases) :
terom@17:         """
terom@17:             Sync the entire given set of valid leases.
terom@17:         """
terom@17:         
terom@17:         log.info("%d leases", len(leases))
terom@17: 
terom@17:         # XXX: any difference? Mostly removed leases, but... they should expire by themselves, right?
terom@17:         self.process_leases(leases)
terom@17: 
terom@17:     def main (self, poll) :
terom@15:         """
terom@15:             Read items from syslog source with given polling style.
terom@15: 
terom@15:             TODO: poll = false on SIGINT
terom@15:         """
terom@15:         
terom@15:         # mainloop
terom@15:         while True :
terom@17:             if self.syslog :
terom@17:                 # process from source
terom@64:                 for item in self.syslog :
terom@17:                     self.process_syslog(item)
terom@15:             
terom@17:             if self.leases :
terom@17:                 # process internally
terom@17:                 #sync, leases = self.leases.process()
terom@17:                 leases = self.leases.process()
terom@17: 
terom@17:                 #if sync :
terom@17:                 #    self.sync_leases(leases)
terom@17:                 if leases :
terom@17:                     self.process_leases(leases)
terom@17:                 #else :
terom@17:                 #    pass
terom@17: 
terom@64:             if not poll :
terom@15:                 # done
terom@15:                 break
terom@64: 
terom@34:             elif self.syslog :
terom@15:                 # wait
terom@115:                 self.syslog.select(poll)
terom@64: 
terom@34:             else :
terom@64:                 # XXX: for --leases-tail
terom@34:                 time.sleep(poll)
terom@15: 
terom@15:             log.debug("tick")
terom@15: 
terom@15: def main (argv) :
terom@15:     options, args = parse_options(argv)
terom@15: 
terom@16:     # db
terom@16:     if not options.database :
terom@16:         log.error("No database given")
terom@16:         return 1
terom@16: 
terom@16:     log.info("Open up database: %s", options.database)
terom@17:     database = pvl.verkko.db.Database(options.database)
terom@17:    
terom@15:     # syslog
terom@15:     log.info("Open up syslog...")
terom@64:     syslog = pvl.syslog.args.apply(options, optional=True)
terom@15: 
terom@64:     if syslog :
terom@115:         poll = syslog.poll
terom@15:     else :
terom@16:         log.warning("No syslog source given")
terom@64:         poll = None
terom@17: 
terom@17:     # leases
terom@17:     if options.leases_file :
terom@17:         log.info("Open up DHCP leases...")
terom@17:         leases = pvl.verkko.dhcp.leases.DHCPLeasesDatabase(options.leases_file)
terom@17: 
terom@17:         # force polling interval
terom@17:         if options.leases_tail :
terom@17:             # XXX: min between syslog/leases?
terom@17:             poll = options.leases_tail
terom@17: 
terom@17:     else :
terom@17:         leases = None
terom@15: 
terom@15:     # handler + main
terom@17:     handler = DHCPHandler(database, syslog, leases)
terom@15: 
terom@17:     if options.create :
terom@17:         handler.createdb()
terom@17:  
terom@15:     log.info("Enter mainloop...")
terom@17:     handler.main(poll)
terom@15:     
terom@15:     # done
terom@15:     return 0
terom@15: 
terom@15: if __name__ == '__main__':
terom@15:     import sys
terom@15: 
terom@15:     sys.exit(main(sys.argv))