#!/usr/bin/env python # pynslcd.py - main daemon module # # Copyright (C) 2010, 2011 Arthur de Jong # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA # 02110-1301 USA import os import sys import daemon import mypidfile import threading import logging import logging.handlers import signal import ldap import constants # from nslcd.h import config # from configure import cfg # from nslcd.conf import common from tio import TIOStream # configure logging class MyFormatter(logging.Formatter): def format(self, record): msg = logging.Formatter.format(self, record) if record.levelno == logging.DEBUG: msg = 'DEBUG: %s' % msg return msg #logging.basicConfig(level=logging.INFO) # , format='%(message)s' formatter = MyFormatter('%(message)s') stderrhandler = logging.StreamHandler(sys.stderr) stderrhandler.setFormatter(formatter) ##sysloghandler = logging.handlers.SysLogHandler(address='/dev/log') ##sysloghandler.setFormatter(formatter) #logging.getLogger().setFormatter(MyFormatter()) logging.getLogger().addHandler(stderrhandler) #logger = logging.getLogger() #logger.setLevel(logging.INFO) #syslog = logging.handlers.SysLogHandler(address='/dev/log') #formatter = logging.Formatter('%(name)s: %(levelname)s %(message)s') #syslog.setFormatter(formatter) #logger.addHandler(syslog) def display_version(fp): fp.write('%(PACKAGE_STRING)s\n' 'Written by Arthur de Jong.\n' '\n' 'Copyright (C) 2010, 2011 Arthur de Jong\n' 'This is free software; see the source for copying conditions. There is NO\n' 'warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n' % { 'PACKAGE_STRING': config.PACKAGE_STRING, } ); def display_usage(fp): fp.write("Usage: %(program_name)s [OPTION]...\n" "Name Service LDAP connection daemon.\n" " -c, --check check if the daemon already is running\n" " -d, --debug don't fork and print debugging to stderr\n" " --help display this help and exit\n" " --version output version information and exit\n" "\n" "Report bugs to <%(PACKAGE_BUGREPORT)s>.\n" % { 'program_name': cfg.program_name, 'PACKAGE_BUGREPORT': config.PACKAGE_BUGREPORT, } ) def parse_cmdline(): """Parse command-line arguments.""" import getopt cfg.program_name = sys.argv[0] or 'pynslcd' try: optlist, args = getopt.gnu_getopt(sys.argv[1:], 'cdhV', ('check', 'debug', 'help', 'version', )) for flag, arg in optlist: if flag in ('-c', '--check'): cfg.check = True elif flag in ('-d', '--debug'): cfg.debug += 1 elif flag in ('-h', '--help'): display_usage(sys.stdout) sys.exit(0) elif flag in ('-V', '--version'): display_version(sys.stdout) sys.exit(0) if len(args): raise getopt.GetoptError('unrecognized option \'%s\'' % args[0], args[0]) except getopt.GetoptError, reason: sys.stderr.write("%(program_name)s: %(reason)s\n" "Try '%(program_name)s --help' for more information.\n" % { 'program_name': cfg.program_name, 'reason': reason, }) sys.exit(1) def create_socket(): """Returns a socket ready to answer requests from the client.""" import socket import fcntl sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) # remove existing named socket try: os.unlink(config.NSLCD_SOCKET) except OSError: pass # ignore any problems # bind to named socket sock.bind((config.NSLCD_SOCKET)) # close the file descriptor on exit fcntl.fcntl(sock, fcntl.F_SETFD, fcntl.FD_CLOEXEC) # set permissions of socket so anybody can do requests os.chmod(config.NSLCD_SOCKET, 0666) # start listening for connections sock.listen(socket.SOMAXCONN) return sock def log_newsession(): pass # FIXME: implement def getpeercred(fd): return (None, None, None) # FIXME: implement and return uid, gid, pid handlers = {} handlers.update(common.get_handlers('alias')) handlers.update(common.get_handlers('ether')) handlers.update(common.get_handlers('group')) handlers.update(common.get_handlers('host')) handlers.update(common.get_handlers('netgroup')) handlers.update(common.get_handlers('network')) handlers.update(common.get_handlers('pam')) handlers.update(common.get_handlers('passwd')) handlers.update(common.get_handlers('shadow')) def acceptconnection(session): # accept a new connection conn, addr = nslcd_serversocket.accept() # See: http://docs.python.org/library/socket.html#socket.socket.settimeout fp = None try: # probably use finally # indicate new connection to logging module (genrates unique id) log_newsession() # log connection try: uid, gid, pid = getpeercred(conn) logging.debug('connection from pid=%r uid=%r gid=%r', pid, uid, gid) except: raise # FIXME: handle exception gracefully # create a stream object fp = TIOStream(conn) # read request version = fp.read_int32() if version != constants.NSLCD_VERSION: logging.debug('wrong nslcd version id (%r)', version) return action = fp.read_int32() try: handler = handlers[action] except KeyError: logging.warn('invalid action id: %r', action) return handler(fp, session, uid)() finally: if fp: fp.close() def disable_nss_ldap(): """Disable the nss_ldap module to avoid lookup loops.""" import ctypes lib = ctypes.CDLL(config.NSS_LDAP_SONAME) ctypes.c_int.in_dll(lib, '_nss_ldap_enablelookups').value = 0 def worker(): # create a new LDAP session #session = myldap_create_session() session = ldap.initialize(cfg.ldap_uri) # start waiting for incoming connections while True: # wait for a new connection acceptconnection(session) # FIXME: handle exceptions if __name__ == '__main__': # parse options parse_cmdline() # clean the environment os.environ.clear() os.putenv('HOME', '/') os.putenv('TMPDIR', '/tmp') os.putenv('LDAPNOINIT', '1') # disable ldap lookups of host names to avoid lookup loop disable_nss_ldap() # set log level if cfg.debug: logging.getLogger().setLevel(logging.DEBUG) # FIXME: implement #if myldap_set_debuglevel(cfg.debug) != LDAP_SUCCESS: # sys.exit(1) # read configuration file cfg.read(config.NSLCD_CONF_PATH) # set a default umask for the pidfile and socket os.umask(0022) # see if someone already locked the pidfile pidfile = mypidfile.MyPIDLockFile(config.NSLCD_PIDFILE) # see if --check option was given if cfg.check: if pidfile.is_locked(): logging.debug('pidfile (%s) is locked', config.NSLCD_PIDFILE) sys.exit(0) else: logging.debug('pidfile (%s) is not locked', config.NSLCD_PIDFILE) sys.exit(1) # normal check for pidfile locked if pidfile.is_locked(): logging.error('daemon may already be active, cannot acquire lock (%s)', config.NSLCD_PIDFILE) sys.exit(1) # daemonize if cfg.debug: daemon = pidfile else: daemon = daemon.DaemonContext( pidfile=pidfile, signal_map={ signal.SIGTERM: 'terminate', signal.SIGINT: 'terminate', signal.SIGPIPE: None, }) # start daemon with daemon: # start normal logging if not cfg.debug: log_startlogging(); logging.info('version %s starting', config.VERSION) # create socket nslcd_serversocket = create_socket(); # drop all supplemental groups try: os.setgroups(()) except OSError, e: logging.warn('cannot setgroups(()) (ignored): %s', e) # change to nslcd gid if cfg.gid is not None: import grp os.setgid(grp.getgrnam(cfg.gid).gr_gid) # change to nslcd uid if cfg.uid is not None: import pwd u = pwd.getpwnam(cfg.uid) os.setuid(u.pw_uid) os.environ['HOME'] = u.pw_dir logging.info('accepting connections') # start worker threads threads = [] for i in range(cfg.threads): thread = threading.Thread(target=worker, name='thread%d' % i) thread.setDaemon(True) thread.start() logging.debug('started thread %s' % thread.getName()) threads.append(thread) # wait for all threads to die for thread in threads: thread.join(10000)