#!/usr/bin/python
#
# Raises domain and forest function levels
#
# Copyright Matthias Dieter Wallnoefer 2009
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

# Notice: At the moment we have some more checks to do here on the special
# attributes (consider attribute "msDS-Behavior-Version). This is due to the
# fact that we on s4 LDB don't implement their change policy (only certain
# values, only increments possible...) yet.

import sys

# Find right directory when running from source tree
sys.path.insert(0, "bin/python")

import samba.getopt as options
import optparse
import ldb

from samba.auth import system_session
from samba.samdb import SamDB
from samba import DS_DOMAIN_FUNCTION_2000, DS_DOMAIN_FUNCTION_2003
from samba import DS_DOMAIN_FUNCTION_2003_MIXED, DS_DOMAIN_FUNCTION_2008
from samba import DS_DOMAIN_FUNCTION_2008_R2
from samba import DS_DC_FUNCTION_2000, DS_DC_FUNCTION_2003, DS_DC_FUNCTION_2008
from samba import DS_DC_FUNCTION_2008_R2

parser = optparse.OptionParser("domainlevel (show | raise <options>)")
sambaopts = options.SambaOptions(parser)
parser.add_option_group(sambaopts)
parser.add_option_group(options.VersionOptions(parser))
credopts = options.CredentialsOptions(parser)
parser.add_option_group(credopts)
parser.add_option("-H", help="LDB URL for database or target server", type=str)
parser.add_option("--quiet", help="Be quiet", action="store_true")
parser.add_option("--forest", type="choice",
  choices=["2003", "2008", "2008_R2"],
  help="The forest function level (2003 | 2008 | 2008_R2)")
parser.add_option("--domain", type="choice",
  choices=["2003", "2008", "2008_R2"],
  help="The domain function level (2003 | 2008 | 2008_R2)")
opts, args = parser.parse_args()

#
#  print a message if quiet is not set
#
def message(text):
	if not opts.quiet:
		print text

if len(args) == 0:
	parser.print_usage()
	sys.exit(1)

lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)

if opts.H is not None:
	url = opts.H
else:
	url = lp.get("sam database")

samdb = SamDB(url=url, session_info=system_session(), credentials=creds, lp=lp)

domain_dn = SamDB.domain_dn(samdb)

res_forest = samdb.search("CN=Partitions,CN=Configuration," + domain_dn,
  scope=ldb.SCOPE_BASE, attrs=["msDS-Behavior-Version"])
assert(len(res_forest) == 1)

res_domain = samdb.search(domain_dn, scope=ldb.SCOPE_BASE,
  attrs=["msDS-Behavior-Version", "nTMixedDomain"])
assert(len(res_domain) == 1)

res_dc_s = samdb.search("CN=Sites,CN=Configuration," + domain_dn,
  scope=ldb.SCOPE_SUBTREE, expression="(objectClass=nTDSDSA)",
  attrs=["msDS-Behavior-Version"])
assert(len(res_dc_s) >= 1)

try:
	level_forest = int(res_forest[0]["msDS-Behavior-Version"][0])
	level_domain = int(res_domain[0]["msDS-Behavior-Version"][0])
	level_domain_mixed = int(res_domain[0]["nTMixedDomain"][0])

	min_level_dc = int(res_dc_s[0]["msDS-Behavior-Version"][0]) # Init value
	for msg in res_dc_s:
		if int(msg["msDS-Behavior-Version"][0]) < min_level_dc:
			min_level_dc = int(msg["msDS-Behavior-Version"][0])

	if level_forest < 0 or level_domain < 0:
		print >>sys.stderr, "ERROR: Domain and/or forest function level(s) is/are invalid. Correct them or reprovision!"
		sys.exit(1)
	if min_level_dc < 0:
		print >>sys.stderr, "ERROR: Lowest function level of a DC is invalid. Correct this or reprovision!"
		sys.exit(1)
	if level_forest > level_domain:
		print >>sys.stderr, "ERROR: Forest function level is higher than the domain level(s). Correct this or reprovision!"
		sys.exit(1)
	if level_domain > min_level_dc:
		print >>sys.stderr, "ERROR: Domain function level is higher than the lowest function level of a DC. Correct this or reprovision!"
		sys.exit(1)

except KeyError:
	print >>sys.stderr, "ERROR: Could not retrieve the actual domain, forest level and/or lowest DC function level!"
	if args[0] == "show":
		print >>sys.stderr, "So the levels can't be displayed!"
	sys.exit(1)

if args[0] == "show":
	message("Domain and forest function level for domain '" + domain_dn + "'")
	if level_forest < DS_DOMAIN_FUNCTION_2003:
		message("\nATTENTION: You run SAMBA 4 on a forest function level lower than Windows 2003 (Native). This isn't supported! Please raise!")
	if level_domain < DS_DOMAIN_FUNCTION_2003:
		message("\nATTENTION: You run SAMBA 4 on a domain function level lower than Windows 2003 (Native). This isn't supported! Please raise!")
	if min_level_dc < DS_DC_FUNCTION_2003:
		message("\nATTENTION: You run SAMBA 4 on a lowest function level of a DC lower than Windows 2003. This isn't supported! Please step-up or upgrade the concerning DC(s)!")

	message("")

	if level_forest == DS_DOMAIN_FUNCTION_2000:
		outstr = "2000"
	elif level_forest == DS_DOMAIN_FUNCTION_2003_MIXED:
		outstr = "2003 with mixed domains/interim (NT4 DC support)"
	elif level_forest == DS_DOMAIN_FUNCTION_2003:
		outstr = "2003"
	elif level_forest == DS_DOMAIN_FUNCTION_2008:
		outstr = "2008"
	elif level_forest == DS_DOMAIN_FUNCTION_2008_R2:
		outstr = "2008 R2"
	else:
		outstr = "higher than 2008 R2"
	message("Forest function level: (Windows) " + outstr)

	if level_domain == DS_DOMAIN_FUNCTION_2000 and level_domain_mixed != 0:
		outstr = "2000 mixed (NT4 DC support)"
	elif level_domain == DS_DOMAIN_FUNCTION_2000 and level_domain_mixed == 0:
		outstr = "2000"
	elif level_domain == DS_DOMAIN_FUNCTION_2003_MIXED:
		outstr = "2003 with mixed domains/interim (NT4 DC support)"
	elif level_domain == DS_DOMAIN_FUNCTION_2003:
		outstr = "2003"
	elif level_domain == DS_DOMAIN_FUNCTION_2008:
		outstr = "2008"
	elif level_domain == DS_DOMAIN_FUNCTION_2008_R2:
		outstr = "2008 R2"
	else:
		outstr = "higher than 2008 R2"
	message("Domain function level: (Windows) " + outstr)

	if min_level_dc == DS_DC_FUNCTION_2000:
		outstr = "2000"
	elif min_level_dc == DS_DC_FUNCTION_2003:
		outstr = "2003"
	elif min_level_dc == DS_DC_FUNCTION_2008:
		outstr = "2008"
	elif min_level_dc == DS_DC_FUNCTION_2008_R2:
		outstr = "2008 R2"
	else:
		outstr = "higher than 2008 R2"
	message("Lowest function level of a DC: (Windows) " + outstr)

elif args[0] == "raise":
	msgs = []

	if opts.domain is not None:
		arg = opts.domain

		if arg == "2003":
			new_level_domain = DS_DOMAIN_FUNCTION_2003
		elif arg == "2008":
			new_level_domain = DS_DOMAIN_FUNCTION_2008
		elif arg == "2008_R2":
			new_level_domain = DS_DOMAIN_FUNCTION_2008_R2

		if new_level_domain <= level_domain and level_domain_mixed == 0:
			print >>sys.stderr, "ERROR: Domain function level can't be smaller equal to the actual one!"
			sys.exit(1)

		if new_level_domain > min_level_dc:
			print >>sys.stderr, "ERROR: Domain function level can't be higher than the lowest function level of a DC!"
			sys.exit(1)

		# Deactivate mixed/interim domain support
		if level_domain_mixed != 0:
			m = ldb.Message()
			m.dn = ldb.Dn(samdb, domain_dn)
			m["nTMixedDomain"] = ldb.MessageElement("0",
			  ldb.FLAG_MOD_REPLACE, "nTMixedDomain")
			samdb.modify(m)

		m = ldb.Message()
		m.dn = ldb.Dn(samdb, domain_dn)
		m["msDS-Behavior-Version"]= ldb.MessageElement(
		  str(new_level_domain), ldb.FLAG_MOD_REPLACE,
                  "msDS-Behavior-Version")
		samdb.modify(m)

		level_domain = new_level_domain

		msgs.append("Domain function level changed!")

	if opts.forest is not None:
		arg = opts.forest

		if arg == "2003":
			new_level_forest = DS_DOMAIN_FUNCTION_2003
		elif arg == "2008":
			new_level_forest = DS_DOMAIN_FUNCTION_2008
		elif arg == "2008_R2":
			new_level_forest = DS_DOMAIN_FUNCTION_2008_R2

		if new_level_forest <= level_forest:
			print >>sys.stderr, "ERROR: Forest function level can't be smaller equal to the actual one!"
			sys.exit(1)

		if new_level_forest > level_domain:
			print >>sys.stderr, "ERROR: Forest function level can't be higher than the domain function level(s). Please raise it/them first!"
			sys.exit(1)

		m = ldb.Message()
		m.dn = ldb.Dn(samdb, "CN=Partitions,CN=Configuration,"
		  + domain_dn)
		m["msDS-Behavior-Version"]= ldb.MessageElement(
		  str(new_level_forest), ldb.FLAG_MOD_REPLACE,
                  "msDS-Behavior-Version")
		samdb.modify(m)

		msgs.append("Forest function level changed!")

	msgs.append("All changes applied successfully!")

	message("\n".join(msgs))
else:
	print >>sys.stderr, "ERROR: Wrong argument '" + args[0] + "'!"
	sys.exit(1)