#!/usr/bin/python
# -*- coding: utf-8 -*-

"""Script for restarting services that refer to old/deleted libs."""

from __future__ import print_function

import argparse
import glob
import os
import signal
import sys
import time


# Set of paths that are "OK" and safe to ignore.
IGNORE_PATHS = set((
	'/dev/zero',
	'/etc/ld.so.cache',
	'/usr/share/icons/Adwaita/icon-theme.cache',
	'/usr/share/icons/gnome/icon-theme.cache',
	'/usr/share/icons/hicolor/icon-theme.cache',
	'/usr/share/mime/mime.cache',
))


def find_svcs():
	"""Find all programs w/deleted paths."""
	svcs = {}
	for pid in os.listdir('/proc'):
		try:
			pid_nr = int(pid)
		except ValueError:
			continue

		map = '/proc/%s/maps' % pid
		if not os.path.exists(map):
			print('skipping %s' % pid)
			continue

		old_paths = set()
		for line in open(map):
			if not line.endswith(' (deleted)\n'):
				continue
			# b71c7000-b7307000 rw-s 00000000 00:04 17024337   /dev/zero (deleted)
			addr, perm, offset, dev, inode, path = line.split(' ', 5)
			# Handle paths with spaces.
			path = path.lstrip().rsplit(' ', 2)[0]
			if (path == '/[aio]' or
			    path.startswith('/memfd:') or
			    path.startswith('/SYSV') or
			    path.startswith('/dev/shm/') or
			    path.startswith('/tmp/')):
				continue
			old_paths.add(path)

		old_paths -= IGNORE_PATHS
		if not old_paths:
			continue

		cmdline = open('/proc/%s/cmdline' % pid).read().split('\0')
		try:
			while True:
				cmdline.remove('')
		except ValueError:
			pass
		svcs[pid_nr] = {
			'cmdline': cmdline,
			'old_paths': old_paths,
		}
	return svcs


# Mapping of known programs to their init.d scripts.
SERVICES = {
	'/usr/sbin/acpid': 'acpid',
	'/usr/sbin/apache2': 'apache2',
	'/usr/sbin/atd': 'atd',
	'/usr/sbin/bacula-fd': 'bacula-fd',
	'/usr/sbin/cron': 'vixie-cron',
	'/usr/sbin/crond': 'dcron',
	'/usr/sbin/ntpd': 'ntpd',
	'/usr/sbin/snmpd': 'snmpd',
	'/usr/sbin/sshd': 'sshd',
	'/usr/sbin/syslog-ng': 'syslog-ng',
	'/usr/sbin/xinetd': 'xinetd',
	'/usr/bin/daisydog': 'daisydog',
	'/usr/bin/distccd': 'distccd',
	'/usr/bin/monit': 'monit',
	'/usr/bin/rsync': 'rsyncd',
	'/usr/sbin/smbd': 'samba',
	'/usr/bin/stunnel': 'stunnel',
	'/usr/bin/tor': 'tor',
	'/usr/bin/transmission-daemon': 'transmission-daemon',
	'/usr/bin/mediatomb': 'mediatomb',
	'/lib/systemd/systemd-udevd': 'udev',
	'/usr/libexec/nrpe': 'nrpe',
	'//usr/libexec/postfix/master': 'postfix',
	'denyhosts.py': 'denyhosts',
	'dropbear': 'dropbear',
	'galileo': 'galileo',
	'tlsdated': 'tlsdated',
}
def auto_restart(opts, svcs):
	kill = set()
	restart = set()
	for pid, svc in svcs.items():
		if svc['cmdline'][0] == '/sbin/agetty':
			kill.add(pid)
		elif 'postgres:' in svc['cmdline'][0]:
			p = os.path.basename(glob.glob('/etc/runlevels/default/postgresql-*')[0])
			restart.add(p)
		elif svc['cmdline'][0].startswith('metalog'):
			restart.add('metalog')
		else:
			prog = svc['cmdline'][0]
			if prog.startswith('/usr/bin/python'):
				prog = os.path.basename(svc['cmdline'][1])

			init = SERVICES.get(prog)
			if init:
				restart.add(init)

	if kill or restart:
		for pid in kill:
			print('killing %s (%s)' % (pid, svcs[pid]['cmdline'][0]))
			if not opts.dryrun:
				os.kill(pid, signal.SIGTERM)
		for init in restart:
			print('restarting %s' % init)
			if not opts.dryrun:
				os.system('/etc/init.d/%s -q restart' % init)

		if not opts.dryrun:
			time.sleep(1)
			svcs = find_svcs()

	return svcs


def summarize(svcs):
	print()
	sslh = False
	for pid in svcs.keys():
		if svcs[pid]['cmdline'][0] == '/usr/sbin/sslh':
			del svcs[pid]
			sslh = True
	if sslh:
		print('sslh needs restart')

	print()
	for pid, svc in svcs.items():
		print(pid, svc['cmdline'])
		print('\t%s' % '\n\t'.join(svc['old_paths']))


def get_parser():
	parser = argparse.ArgumentParser(description=__doc__)
	parser.add_argument('-n', '--dry-run', dest='dryrun', action='store_true',
	                    help='Show what would be restarted (and why)')
	return parser


def main(argv):
	parser = get_parser()
	opts = parser.parse_args(argv)

	svcs = find_svcs()
	svcs = auto_restart(opts, svcs)
	summarize(svcs)


if __name__ == '__main__':
	exit(main(sys.argv[1:]))