bin/pvl.syslog-dhcp
changeset 150 f12e83f8c34b
parent 115 9772d43669fb
child 169 a81ca751664d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bin/pvl.syslog-dhcp	Sun Jan 20 18:19:03 2013 +0200
@@ -0,0 +1,436 @@
+#!/usr/bin/env python
+
+"""
+    Monitor DHCP use.
+"""
+
+__version__ = '0.0'
+
+import pvl.args
+import pvl.syslog.args
+
+import pvl.verkko.db as db
+import pvl.syslog.dhcp
+import pvl.verkko.dhcp.leases
+
+import logging, optparse
+
+log = logging.getLogger('main')
+
+# name of process in syslog
+DHCP_SYSLOG_PROG = 'dhcpd'
+
+def parse_options (argv) :
+    """
+        Parse command-line arguments.
+    """
+
+    prog = argv[0]
+
+    parser = optparse.OptionParser(
+            prog        = prog,
+            usage       = '%prog: [options]',
+            version     = __version__,
+
+            # module docstring
+            description = __doc__,
+    )
+    
+    # options
+    parser.add_option_group(pvl.args.parser(parser))
+
+    ## syslog
+    parser.add_option_group(pvl.syslog.args.parser(parser, prog=DHCP_SYSLOG_PROG))
+
+    ## leases
+    parser.add_option('--leases-file',          metavar='FILE',
+            help="Synchronize dhcpd leases from given file")
+
+    parser.add_option('--leases-tail',          type='float', metavar='POLL',
+            help="Continuously poll leases file XXX: overrides --syslog-tail")
+
+
+    ## XXX: networks
+    parser.add_option('--network',              metavar='NET', action='append',
+            help="Filter leases by network prefix as plugin instance")
+
+    parser.add_option('--gateway',              metavar='GW/IFACE', action='append',
+            help="Filter messages by gateway/interface as plugin instance")
+
+    ## hosts
+    parser.add_option('--database',             metavar='URI',
+            help="Track hosts in given database")
+
+    parser.add_option('--create',               action='store_true',
+            help="Initialize database")
+
+    # defaults
+    parser.set_defaults(
+
+    )
+    
+    # parse
+    options, args = parser.parse_args(argv[1:])
+    
+    # apply
+    pvl.args.apply(options, prog)
+
+    if not options.database :
+        parser.error("Missing required option: --database")
+
+    return options, args
+
+class DHCPHostsDatabase (object) :
+    """
+        The dhcp_hosts table in our database.
+    """
+
+    def __init__ (self, db) :
+        self.db = db
+
+    def create (self) :
+        """
+            CREATE TABLEs
+        """
+
+        log.info("Creating database tables: dhcp_hosts")
+        db.dhcp_hosts.create(self.db.engine, checkfirst=True)
+
+    def insert (self, attrs) :
+        """
+            INSERT new host
+        """
+
+        query = db.dhcp_hosts.insert().values(
+                ip          = attrs['ip'],
+                mac         = attrs['mac'],
+                gw          = attrs['gw'],
+
+                first_seen  = attrs['timestamp'],
+                count       = 1,
+
+                last_seen   = attrs['timestamp'],
+                state       = attrs['state'],
+                
+                name        = attrs.get('name'),
+                error       = attrs.get('error'),
+        )
+        
+        # -> id
+        return self.db.insert(query)
+
+    def update (self, attrs) :
+        """
+            UPDATE existing host, or return False if not found.
+        """
+
+        table = db.dhcp_hosts
+
+        query = table.update()
+        query = query.where((table.c.ip == attrs['ip']) & (table.c.mac == attrs['mac']) & (table.c.gw == attrs['gw']))
+        query = query.values(
+                count       = db.func.coalesce(table.c.count, 0) + 1,
+
+                # set
+                last_seen   = attrs['timestamp'],
+                state       = attrs['state'],
+        )
+        
+        if 'name' in attrs :
+            query = query.values(name = attrs['name'])
+        
+        if 'error' in attrs :
+            query = query.values(error = attrs['error'])
+
+        # any matched rows?
+        return self.db.update(query)
+
+    def process (self, item) :
+        """
+            Process given DHCP syslog message to update the hosts table.
+        """
+
+        attrs = {}
+        
+        # ignore unless we have enough info to fully identify the client
+        # this means that we omit DHCPDISCOVER messages, but we get the OFFER/REQUEST/ACK
+        if any(name not in item for name in ('lease', 'hwaddr', 'gateway')) :
+            # ignore; we require these
+            return
+
+        # do not override error from request on NAK; clear otherwise
+        if item.get('type') == 'DHCPNAK' :
+            pass
+        else :
+            attrs['error'] = item.get('error')
+
+        # do not override name unless known
+        if item.get('name') :
+            attrs['name'] = item.get('name')
+
+        # db: syslog
+        ATTR_MAP = (
+            ('ip',          'lease'),
+            ('mac',         'hwaddr'),
+            ('gw',          'gateway'),
+
+            ('timestamp',   'timestamp'),
+            ('state',       'type'),
+        )
+
+        # generic attrs
+        for key, name in ATTR_MAP :
+            attrs[key] = item.get(name)
+
+        # update existing?
+        if self.update(attrs) :
+            log.info("Update: %s", attrs)
+
+        else :
+            # new
+            log.info("Insert: %s", attrs)
+            self.insert(attrs)
+
+class DHCPLeasesDatabase (object) :
+    def __init__ (self, db) :
+        self.db = db
+
+    def create (self) :
+        """
+            CREATE TABLEs
+        """
+
+        log.info("Creating database tables: dhcp_leases")
+        db.dhcp_leases.create(self.db.engine, checkfirst=True)
+
+    def update (self, lease) :
+        """
+            Try an extend an existing lease?
+        """
+
+        c = db.dhcp_leases.c
+
+        ip = lease['lease']
+        mac = lease.get('hwaddr')
+        starts = lease['starts']
+        ends = lease.get('ends')
+
+        update = db.dhcp_leases.update()
+        
+        # XXX: if ends is None?
+        if mac :
+            # renew lease..?
+            update = update.where((c.ip == ip) & (c.mac == mac) & ((starts < c.ends) | (c.ends == None)))
+        else :
+            # new state for lease..?
+            update = update.where((c.ip == ip) & ((starts < c.ends) | (c.ends == ends)))
+
+        update = update.values(
+                state       = lease['binding-state'],
+                next        = lease.get('next-binding-state'),
+                ends        = ends,
+        )
+
+        if lease.get('client-hostname') :
+            update = update.values(hostname = lease['client-hostname'])
+
+        return self.db.update(update) > 0
+
+    def insert (self, lease) :
+        """
+            Record a new lease.
+        """
+
+        c = db.dhcp_leases.c
+
+        query = db.dhcp_leases.insert().values(
+            ip          = lease['lease'],
+            mac         = lease['hwaddr'],
+            hostname    = lease.get('client-hostname'),
+
+            starts      = lease['starts'],
+            ends        = lease.get('ends'),
+
+            state       = lease['binding-state'],
+            next        = lease.get('next-binding-state'),
+        )
+
+        return self.db.insert(query)
+
+    def process (self, lease) :
+        """
+            Process given DHCP lease to update currently active lease, or insert a new one.
+        """
+
+        # update existing?
+        if self.update(lease) :
+            log.info("Update: %s", lease)
+
+        elif lease.get('hwaddr') :
+            # new
+            id = self.insert(lease)
+
+            log.info("Insert: %s -> %d", lease, id)
+
+        else :
+            # may be a free lease
+            log.warn("Ignored lease: %s", lease)
+
+# XXX: mainloop
+import time
+
+class DHCPHandler (object) :
+    """
+        Process lines from syslog
+    """
+
+    def __init__ (self, db, syslog, leases) :
+        self.db = db
+
+        self.syslog = syslog
+        self.leases = leases
+
+        self.hostdb = DHCPHostsDatabase(db)
+        self.leasedb = DHCPLeasesDatabase(db)
+
+        # XXX
+        self.filter = pvl.syslog.dhcp.DHCPSyslogFilter()
+
+    def createdb (self) :
+        """
+            Initialize database tables.
+        """
+
+        self.hostdb.create()
+        self.leasedb.create()
+
+    def process_syslog (self, item) :
+        """
+            Handle a single item read from syslog to DB.
+        """
+
+        dhcp_item = self.filter.parse(item['msg'])
+
+        log.debug("%s: %s", item, dhcp_item)
+        
+        if not dhcp_item :
+            # ignore
+            return
+
+        dhcp_item['timestamp'] = item['timestamp'] # XXX: fixup DHCPSyslogParser?
+
+        if item.get('error') :
+            item['error'] = self.filter.parse_error(item['error'])
+
+        self.hostdb.process(dhcp_item)
+
+    def process_leases (self, leases) :
+        """
+            Handle given changed lease.
+        """
+        
+        for lease in leases :
+            log.info("%s", lease['lease'])
+
+            self.leasedb.process(lease)
+
+    def sync_leases (self, leases) :
+        """
+            Sync the entire given set of valid leases.
+        """
+        
+        log.info("%d leases", len(leases))
+
+        # XXX: any difference? Mostly removed leases, but... they should expire by themselves, right?
+        self.process_leases(leases)
+
+    def main (self, poll) :
+        """
+            Read items from syslog source with given polling style.
+
+            TODO: poll = false on SIGINT
+        """
+        
+        # mainloop
+        while True :
+            if self.syslog :
+                # process from source
+                for item in self.syslog :
+                    self.process_syslog(item)
+            
+            if self.leases :
+                # process internally
+                #sync, leases = self.leases.process()
+                leases = self.leases.process()
+
+                #if sync :
+                #    self.sync_leases(leases)
+                if leases :
+                    self.process_leases(leases)
+                #else :
+                #    pass
+
+            if not poll :
+                # done
+                break
+
+            elif self.syslog :
+                # wait
+                self.syslog.select(poll)
+
+            else :
+                # XXX: for --leases-tail
+                time.sleep(poll)
+
+            log.debug("tick")
+
+def main (argv) :
+    options, args = parse_options(argv)
+
+    # db
+    if not options.database :
+        log.error("No database given")
+        return 1
+
+    log.info("Open up database: %s", options.database)
+    database = pvl.verkko.db.Database(options.database)
+   
+    # syslog
+    log.info("Open up syslog...")
+    syslog = pvl.syslog.args.apply(options, optional=True)
+
+    if syslog :
+        poll = syslog.poll
+    else :
+        log.warning("No syslog source given")
+        poll = None
+
+    # leases
+    if options.leases_file :
+        log.info("Open up DHCP leases...")
+        leases = pvl.verkko.dhcp.leases.DHCPLeasesDatabase(options.leases_file)
+
+        # force polling interval
+        if options.leases_tail :
+            # XXX: min between syslog/leases?
+            poll = options.leases_tail
+
+    else :
+        leases = None
+
+    # handler + main
+    handler = DHCPHandler(database, syslog, leases)
+
+    if options.create :
+        handler.createdb()
+ 
+    log.info("Enter mainloop...")
+    handler.main(poll)
+    
+    # done
+    return 0
+
+if __name__ == '__main__':
+    import sys
+
+    sys.exit(main(sys.argv))