#!/usr/bin/python3
#
#Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008 Olivier Sessink
#All rights reserved.
#
#Redistribution and use in source and binary forms, with or without
#modification, are permitted provided that the following conditions 
#are met:
#  * Redistributions of source code must retain the above copyright 
#    notice, this list of conditions and the following disclaimer.
#  * Redistributions in binary form must reproduce the above 
#    copyright notice, this list of conditions and the following 
#    disclaimer in the documentation and/or other materials provided 
#    with the distribution.
#  * The names of its contributors may not be used to endorse or 
#    promote products derived from this software without specific 
#    prior written permission.
#
#THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
#"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
#LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
#FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
#COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
#INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
#BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
#LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
#CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
#LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
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#POSSIBILITY OF SUCH DAMAGE.
#

from __future__ import print_function

import os.path
import grp
import pwd
import sys
import getopt
import string
import shutil

PREFIX='/usr'
INIPREFIX='/etc/jailkit'
LIBDIR='/usr/share/jailkit'
sys.path.append(LIBDIR)
import jk_lib

def striptrailingslash(dir):
	if (dir[-1] == '/'):
		return dir[:-1]
	return dir

def dirinjail(testdir, jail):
	if (testdir[-1]!= '/'):
			testdir = testdir+'/'
	return (jail == testdir[:len(jail)])
	

def addgrouptojail(jail, group_id, user, config):
	jail = striptrailingslash(jail)
	gr = grp.getgrgid(group_id)
	if (not jk_lib.test_group_exist(gr.gr_name, jail+'/etc/group')):
		file = jail+'/etc/group'
		if (config['verbose'] == 1):
			print('adding group '+gr[0]+' to '+file)
		try:
			tmp = gr[0]+':x:'+str(gr[2])+':'
			if (type(user)==str and len(user)>0):
				tmp = tmp + user
			tmp = tmp + '\n'
			fd = open(file, 'a')
			fd.write(tmp)
			fd.close()
		except IOError:
			sys.stderr.write('ERROR: failed to write group '+gr[0]+' to '+file+'\n')
			return 0
	return 1

def addusertogroupinjail(jail, group_id, user, config):
	ret = addgrouptojail(jail, group_id, user, config)
	if (ret == 0):
		return 0
	try:
		file = jail+'/etc/group'
		fd = open(file, 'r+')
		line = fd.readline()
		if sys.version_info > (3, 0) and isinstance(line, bytes):                                               #Python 3
			line = line.decode('utf-8', 'replace')
		while (len(line)>0):
			splitted = line.split(':')
			if (len(splitted)==4 and int(splitted[2]) == group_id):
				users = splitted[3][:-1].split(',')
				if (user in users):
					fd.close()
					return 1
				else :
					if (config['verbose']):
						print('Adding user '+user+' to group '+splitted[0])
					pos = fd.tell()
					buf = fd.read()
					fd.seek(pos-len(line))
					if (len(users)==1 and users[0] == ''):
						users = [user]
					else:
						users.append(user)
					tmp = splitted[0]+':x:'+splitted[2]+':'
					tmp2 = ','.join(users)
					tmp += tmp2+'\n'+buf
					fd.write(tmp)
					fd.close()
					return 1
			line = fd.readline()
			if sys.version_info > (3, 0) and isinstance(line, bytes):                                               #Python 3
				line = line.decode('utf-8', 'replace')
	except IOError:
		sys.stderr.write('ERROR: failed to add user '+user+' to group '+str(group_id)+' in '+file+'\n')
		return 0
	return 0
	
def addusertojail(jail, user, shell, config):
	jail = striptrailingslash(jail)
	if (jk_lib.test_user_exist(user, jail+'/etc/passwd')):
		if (config['verbose']):
			sys.stderr.write('user '+user+' already exists in '+jail+'/etc/passwd\n')
		return 1
	pw = pwd.getpwnam(user)
	# the next check MUST include a trailing slash! (otherwise if a user
	# has a homedir that starts with the same string as the jail directory
	# the check has the wrong result)
	if (dirinjail(pw[5], jail)):
		if (pw[5][0:len(jail)+3] == jail+'/./'):
			jailhome = pw[5][len(jail)+2:]
		else:
			jailhome = pw[5][len(jail):]
	else:
		jailhome = pw[5]
	try:
		if (sys.platform[4:7] == 'bsd'):
			file = jail+'/etc/master.passwd'
			if (config['verbose'] == 1):
				print('adding user '+user+' to '+file+' with shell '+shell)
			fd = open(file, 'a')
			fd.write(user+':x:'+str(pw[2])+':'+str(pw[3])+'::0:0:'+pw[4]+':'+jailhome+':'+shell+'\n')
			fd.close()
			# adding -u user might speed up the next command, but if the password files do not exist
			# yet (and jail/etc/spwd.db does not exist) this generates an error
			postcommand = 'pwd_mkdb -p -d '+jail+'/etc '+jail+'/etc/master.passwd && rm '+jail+'/etc/spwd.db'
		else:
		#if (sys.platform[:5] == 'linux'):
			file  = jail+'/etc/passwd'
			if (config['verbose'] == 1):
				print('adding user '+user+' to '+file+' with shell '+shell)
			fd = open(file, 'a')
			fd.write(user+':x:'+str(pw[2])+':'+str(pw[3])+':'+pw[4]+':'+jailhome+':'+shell+'\n')
			fd.close()
			postcommand = None
	except IOError:
		sys.stderr.write('failed to write to '+file+'\n')
		return 0
	if (postcommand != None):
		ret = os.system(postcommand)
		if (ret != 0):
			sys.stderr.write('failed to execute '+postcommand+'\n')
			return 0
	return 1

def moduser(user, home, shell=PREFIX+'/sbin/jk_chrootsh'):
	if (sys.platform[:7] == 'freebsd'):
		command = 'pw usermod '+user+' -d '+home+' -s '+shell
	elif (sys.platform[:5] == 'linux') or (sys.platform[:7] == 'openbsd') or (sys.platform[:6] == 'sunos5'):
		command = 'usermod -d '+home+' -s '+shell+' '+user
	else:
		sys.stderr.write('please report that user modding on platform '+sys.platform+' is not yet handled\n')
		sys.stderr.write('to the jailkit developers, and suggest which command is needed to modify users\n')
		return 0
	if (os.system(command)!=0):
		sys.stderr.write('failed to execute '+command+'\n')
		return 0
	return 1

def jailuser(jail, user, movehome, config):
	pw = pwd.getpwnam(user)
	if (jail[-1] != '/'):
		jail = jail + '/'
	# add the user in the jail
	if (not addusertojail(jail, user, config['shell'], config)):
		sys.exit(2)
	# lookup the primary group and make sure it also exists in the jail
	if not addgrouptojail(jail, pw[3], None, config):
		return 0
	# look up all other groups
	groups = grp.getgrall()
	for gr in groups:
		if (user in gr.gr_mem):
			ret = addusertogroupinjail(jail, gr.gr_gid, user, config)
			if not ret:
				return 0
	# change the shell and the homedir
	if (dirinjail(pw[5], jail)):
		# the home is within in the jail already, does it have the /./ sequence?
		if (pw[5][:len(jail)+2] == jail+'./'):
			newhome = pw[5]
			#print('no need to change home ',newhome)
		else:
			newhome = jail+'.'+pw[5][len(jail)-1:]
			#print('add jail separator, newhome=',newhome)
	else:
		newhome = jail+'.'+pw[5]
		#print('user not in jail, newhome=',newhome)
	newhome = striptrailingslash(newhome)
	oldhome = striptrailingslash(pw[5])
	if (oldhome != newhome or pw[6] != PREFIX+'/sbin/jk_chrootsh'):
		if (config['verbose'] == 1):
			print('modify user '+user+'; dir '+newhome+' and shell '+PREFIX+'/sbin/jk_chrootsh')
		if (not moduser(user,newhome,PREFIX+'/sbin/jk_chrootsh')):
			sys.stderr.write('failed to modify user '+user+'\n')
	else:
		if (config['verbose'] == 1):
			print('user '+user+' has a correct home directory and shell already')
	#move directory contents
	if (movehome == 1):
		if (oldhome == newhome):
			print('home directory '+oldhome+' is already inside the jail')
		else:
			if (not os.path.exists(oldhome)):
				sys.stderr.write('home directory '+oldhome+' does not exist, nothing moved\n')
			else:
				# test if the base directory for newhome exists
				tmp = os.path.dirname(oldhome)
				#tmp = jk_lib.nextpathup(oldhome)
				jk_lib.create_parent_path(jail,tmp, config['verbose'], copy_permissions=1, allow_suid=0, copy_ownership=0)
				if (config['verbose'] == 1):
					print('Moving files from '+oldhome+' to '+newhome)
				jk_lib.move_dir_with_permissions_and_owner(oldhome,newhome,(config['verbose']==1))

def user_exists(user):
	try:
		pw= pwd.getpwnam(user)
		return 1
	except:
		return 0
	return 0

def usage():
	print
	print('Usage: '+sys.argv[0]+' [OPTIONS] username [more usernames]')
	print()
	print(' -j | --jail= jaildir   : jail directory')
	print(' -v | --verbose        : verbose output')
	print(' -n | --noninteractive : no user interaction')
	print(' -s | --shell= shell    : set shell inside jail ('+PREFIX+'/sbin/jk_lsh default)')
	print(' -m | --move           : move home if home outside jail')
	print(' -h | --help           : this message')
	print()

def testjail(jail, shell):
	if (type(jail) != str or len(jail)==0):
		return 0
	if (jail[-1:] == '/'):
		jail = jail[:-1]
	if (not os.path.exists(jail)):
		sys.stderr.write(jail+' does not exist\n')
		return 0
	if (not os.path.exists(jail+'/etc/passwd')):
		sys.stderr.write('invalid jail, '+jail+'/etc/passwd does not exist\n')
		return 0
	if (not os.path.exists(jail+shell)):
		sys.stderr.write('invalid shell, '+jail+shell+' does not exist\n')
		return 0
	if (not os.access(jail+shell,os.X_OK)):
		sys.stderr.write('invalid shell, '+jail+shell+' is not executable\n')
		return 0
	return 1

def getjail(jail, config):
	"""returns a jail that will have a slash appended"""
	while (1):
		if (type(jail) == str and len(jail)>0 and jail[0] != '/'):
			tmp = os.getcwd()+'/'+jail
			if (os.path.exists(tmp)):
				jail = tmp
		if (type(jail) == str and len(jail)>0 and jail[-1] != '/'):
			jail=jail+'/'
		test = testjail(jail, config['shell'])
		if (test == 1):
			return jail
		else:
			if (not test):
				jail = None
			if (jail == None):
				if (config['interactive'] == 1):
					if sys.version_info > (3, 0):                                               #Python 3
						jail = input('enter jail directory: ')
					else:
						jail = raw_input('enter jail directory: ')
				else:
					sys.exit(33)

def getmovehome(jail,user,config):
	pw = pwd.getpwnam(user)
	if (pw[5][0:len(jail)] == jail): # pw[5] == pw.pw_dir
		return 0
	print('home directory '+pw.pw_dir+' is not within '+jail+', move the directory contents?')
	if sys.version_info > (3, 0):                                               #Python 3
		tmp = input('[Y]/[n]')
	else:
		tmp = raw_input('[Y]/[n]')
	if (tmp == 'Y' or tmp == 'y' or tmp == ''):
		return 1
	return 0

def main():
	try:
		opts, args = getopt.getopt(sys.argv[1:],"vs:j:nmh?",['help', 'verbose', 'shell=', 'nomove', 'move', 'jail='])
	except getopt.GetoptError:
		usage()
		sys.exit(1)
	config = {}
	config['verbose'] = 0
	config['interactive'] = 1
	config['movehome'] = -1 # -1 = interactive
	config['shell'] = PREFIX+'/sbin/jk_lsh' # default shell
	jail = None
	for o, a in opts:
		if o in ("-h", "-?", "--help"):
			usage()
			sys.exit()
		elif o in ("-v", "--verbose"):
			config['verbose'] = 1
		elif o in ('-s', '--shell'):
			config['shell'] = a
		elif o in ("-m", "--move"):
			config['movehome'] = 1
		elif o in ("-n", "--noninteractive"):
			config['interactive'] = 0
		elif o in ('-j', '--jail'):
			jail = a
	if (config['interactive'] == 0 and config['movehome'] == -1):
		config['movehome'] = 0
	if (len(args)==0):
		print
		print('aborted, no username specified')
		sys.exit(2)
	try:
		jail = getjail(jail,config)
		for username in args:
			if user_exists(username):
				if (config['movehome'] == -1):
					movehome = getmovehome(jail, username, config)
				else:
					movehome = config['movehome']
				jailuser(jail, username, movehome, config)
			else:
				print('user '+username+' does not exist')
	except KeyboardInterrupt:
		print
		print('aborted.. ')
		sys.exit(1)

if __name__ == "__main__":
	main()