#!/usr/bin/python3

# Copyright (c) 2017 Leo Antunes <leo@costela.net>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


from __future__ import print_function

import os
import sys
from glob import iglob
import argparse
import logging

__version__ = '0.1.0'

OK = 0
WARNING = 1
CRITICAL = 2
UNKNOWN = 3


def main():
    argparser = argparse.ArgumentParser()
    argparser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
    argparser.add_argument('--quiet', action='store_true', help='no output if nothing found')
    argparser.add_argument('--verbose', action='store_true', help='be verbose about the search process')

    args = argparser.parse_args()

    logger = logging.getLogger(os.path.basename(sys.argv[0]))
    if args.verbose:
        logging.basicConfig(level=logging.DEBUG)
    else:
        logging.basicConfig(level=logging.WARNING)

    needs_reload = dict()
    for proc in iglob('/proc/[0-9]*'):  # numbers to avoid e.g. /proc/self
        exe = os.path.join(proc, 'exe')
        if os.path.exists(exe):
            try:
                proc_pid = os.path.basename(proc)
                proc_name = os.path.basename(os.path.realpath(exe))
                logger.debug('checking process %s', proc_name)
                os.chdir(os.path.join(proc, 'map_files'))
                for map_file in os.listdir('.'):
                    # all files in /map_files/ are absolute symlinks, so we don't need abspath()
                    real_map_file_path = os.path.realpath(map_file)
                    if not '/lib/' in real_map_file_path:
                        logger.debug('skipping non-lib path %s', real_map_file_path)
                        continue
                    else:
                        logger.debug('checking lib %s', real_map_file_path)
                    if os.stat(map_file).st_nlink == 0:
                        needs_reload.setdefault(proc_name, set()).add(proc_pid)
            except FileNotFoundError:
                pass
        else:
            logger.debug('skipping kernel process %s', os.path.basename(proc))

    if needs_reload:
        procs_with_pids = ', '.join(map(lambda x: '%s (%s)' % (x, ', '.join(needs_reload[x])), needs_reload))
        print('The following processes have libs linked that were upgraded:', procs_with_pids)
        exit(WARNING)
    elif not args.quiet:
        print('No upgraded libs linked in running processes')

    exit(OK)

if __name__ == '__main__':
    try:
        main()
    except Exception as e:
        print('Exception:', e)
        exit(UNKNOWN)
