#!/usr/bin/python # encoding: utf-8 # # Copyright 2018-2019 Greg Neagle. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # https://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """ appusaged Created by Greg Neagle on 2018-04-07. Much code based on and adapted from autopkgserver by Per Olofsson A privileged daemon that records app usage events and install requests to our app usage database. """ import os import sys import time import stat import logging import logging.handlers import SocketServer import socket import plistlib import struct from munkilib import app_usage from munkilib import launchd from munkilib import prefs APPNAME = 'appusaged' VERSION = '0.1' class AppUsageHandlerError(Exception): '''Exception to raise if there is any error in AppUsageHandler''' pass class AppUsageHandler(object): '''Class for working with appusage''' def __init__(self, server, request, uid): '''Arguments: request A request in plist format. uid The uid of the requestor ''' self.server = server self.log = server.log self.request = request self.uid = uid def verify_request(self): '''Make sure copy request has everything we need''' self.log.debug('Verifying request') for key in ['event']: if not key in self.request: raise AppUsageHandlerError('No %s in request' % key) if self.request['event'] in ['install', 'remove']: expected_keys = ['name', 'version'] else: expected_keys = ['app_dict'] for key in expected_keys: if not key in self.request: raise AppUsageHandlerError('No %s in request' % key) def handle(self): '''Handle our request''' self.verify_request() if self.request['event'] in ['install', 'remove']: self.log.info('App install/removal request from uid %s', self.uid) self.log.info('%s', self.request) self.server.usage.log_install_request(self.request) else: self.log.info('App usage event from uid %s', self.uid) self.log.info('%s', self.request) self.server.usage.log_application_usage( self.request['event'], self.request['app_dict']) class RunHandler(SocketServer.StreamRequestHandler): '''Handler for app_usage events''' def verify_request_syntax(self, plist): '''Verify the basic syntax of request plist.''' # pylint: disable=no-self-use # Keep a list of error messages. errors = list() # Root should be a dictionary. if not isinstance(plist, dict): errors.append('Request root is not a dictionary') # Bail out early if it's not. return False, errors syntax_ok = True # TO-DO: Actual verification! return syntax_ok, errors def getpeerid(self): ''' Get peer credentials on a UNIX domain socket. Returns uid, gids. ''' # /usr/include/sys/ucred.h # # struct xucred { # u_int cr_version; /* structure layout version */ # uid_t cr_uid; /* effective user id */ # short cr_ngroups; /* number of advisory groups */ # gid_t cr_groups[NGROUPS]; /* advisory group list */ # }; # pylint: disable=invalid-name LOCAL_PEERCRED = 0x001 XUCRED_VERSION = 0 NGROUPS = 16 # pylint: enable=invalid-name cr_version = 0 cr_uid = 1 cr_ngroups = 2 cr_groups = 3 xucred_fmt = 'IIh%dI' % NGROUPS res = struct.unpack( xucred_fmt, self.request.getsockopt( 0, LOCAL_PEERCRED, struct.calcsize(xucred_fmt))) if res[cr_version] != XUCRED_VERSION: raise OSError('Incompatible struct xucred version') return res[cr_uid], res[cr_groups:cr_groups + res[cr_ngroups]] def handle(self): '''Handle an incoming app_usage event.''' try: # Log through server parent. self.log = self.server.log self.log.debug('Handling request') # Get uid and primary gid of connecting peer. uid, gids = self.getpeerid() gid = gids[0] self.log.debug( 'Got request from uid %d gid %d' % (uid, gid)) # Receive a plist. plist_string = self.request.recv(8192) # Try to parse it. try: plist = plistlib.readPlistFromString(plist_string) except BaseException as err: self.log.error('Malformed request') self.request.send('ERROR:Malformed request\n') return self.log.debug('Parsed request plist') # Verify the plist syntax. syntax_ok, errors = self.verify_request_syntax(plist) if not syntax_ok: self.log.error('Plist syntax error') self.request.send(''.join(['ERROR:%s\n' % e for e in errors])) return self.log.debug( 'Dispatching worker to process request for user %d' % (uid)) try: appusagehandler = AppUsageHandler(self.server, plist, uid) result = appusagehandler.handle() self.request.send(u'OK:%s\n' % result) except AppUsageHandlerError as err: self.request.send(u'ERROR:%s\n' % unicode(err)) except BaseException as err: self.log.error('Run failed: %s' % unicode(err)) self.request.send(u'ERROR:%s\n' % unicode(err)) except BaseException as err: self.log.error('Caught exception: %s' % repr(err)) self.request.send('ERROR:Caught exception: %s' % repr(err)) return class AppUsageDaemonError(Exception): '''Exception to raise for AppUsageDaemon errors''' pass class AppUsageDaemon(SocketServer.UnixStreamServer): '''Daemon that runs as root, receiving app_usage events.''' allow_reuse_address = True request_queue_size = 10 timeout = 10 def __init__(self, socket_fd, RequestHandlerClass): # Avoid initialization of UnixStreamServer as we need to open the # socket from a file descriptor instead of creating our own. # pylint: disable=super-init-not-called self.socket = socket.fromfd( socket_fd, socket.AF_UNIX, socket.SOCK_STREAM) self.socket.listen(self.request_queue_size) # now do the base class's init # pylint: disable=non-parent-init-called SocketServer.BaseServer.__init__( self, self.socket.getsockname(), RequestHandlerClass) self.usage = app_usage.ApplicationUsageRecorder() self.log = logging.getLogger(APPNAME) self.timed_out = False def setup_logging(self): '''Configure logging''' try: logging_level = logging.INFO if prefs.pref('LoggingLevel') > 1: logging_level = logging.DEBUG self.log.setLevel(logging_level) log_console = logging.StreamHandler() log_console.setLevel(logging_level) # store the log in the same directory as ManagedSoftwareUpdate.log logfilepath = os.path.join( os.path.dirname(prefs.pref('LogFile')), APPNAME + '.log') log_file = logging.handlers.RotatingFileHandler( logfilepath, 'a', 100000, 9, 'utf-8') log_file.setLevel(logging_level) console_formatter = logging.Formatter('%(message)s') file_formatter = logging.Formatter( '%(asctime)s %(module)s[%(process)d]: ' '%(message)s (%(funcName)s)') log_console.setFormatter(console_formatter) log_file.setFormatter(file_formatter) self.log.addHandler(log_console) self.log.addHandler(log_file) except (OSError, IOError) as err: raise AppUsageDaemonError( 'Can\'t open log: %s' % (err.strerror)) def handle_timeout(self): self.timed_out = True def main(): '''Start our daemon, connect to socket and process events''' # Make sure we're launched as root if os.geteuid() != 0: print >> sys.stderr, '%s must be run as root.' % APPNAME # Sleep to avoid respawn. time.sleep(10) return 1 # Make sure that the executable and all containing directories are owned # by root:wheel or root:admin, and not writeable by other users. root_uid = 0 wheel_gid = 0 admin_gid = 80 exepath = os.path.realpath(os.path.abspath(__file__)) path_ok = True while True: info = os.stat(exepath) if info.st_uid != root_uid: print >> sys.stderr, '%s must be owned by root.' % exepath path_ok = False if info.st_gid not in (wheel_gid, admin_gid): print >> sys.stderr, '%s must have group wheel or admin.' % exepath path_ok = False if info.st_mode & stat.S_IWOTH: print >> sys.stderr, '%s mustn\'t be world writeable.' % exepath path_ok = False exepath = os.path.dirname(exepath) if exepath == '/': break if not path_ok: # Sleep to avoid immediate respawn. time.sleep(10) return 1 # Keep track of time for launchd. start_time = time.time() # Get socket file descriptors from launchd. socket_fd = launchd.get_socket_fd(APPNAME) if not socket_fd: print >> sys.stderr, 'No socket provided to us by launchd' time.sleep(10) return 1 # Create the daemon object. daemon = AppUsageDaemon(socket_fd, RunHandler) daemon.setup_logging() daemon.log.debug('%s v%s starting', APPNAME, VERSION) # Process incoming requests while True: daemon.handle_request() if not daemon.timed_out: continue # we timed out, so we can exit # Keep running for at least 10 seconds to make launchd happy. run_time = time.time() - start_time daemon.log.debug("run time: %fs", run_time) if run_time < 10.0: # Only sleep for a short while in case new requests pop up. sleep_time = min(1.0, 10.0 - run_time) daemon.log.debug( "sleeping for %f seconds to make launchd happy", sleep_time) time.sleep(sleep_time) else: daemon.log.debug('Nothing to do: exiting') break if __name__ == '__main__': sys.exit(main())