path: root/source4/scripting/bin/upgradeprovision

#!/usr/bin/env python
# vim: expandtab
#
# Copyright (C) Matthieu Patou <mat@matws.net> 2009
#
# Based on provision a Samba4 server by
# Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2007-2008
# Copyright (C) Andrew Bartlett <abartlet@samba.org> 2008
#
#
# 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/>.


import logging
import optparse
import os
import shutil
import sys
import tempfile
import re
import traceback
# Allow to run from s4 source directory (without installing samba)
sys.path.insert(0, "bin/python")

import samba
import samba.getopt as options
from samba.credentials import DONT_USE_KERBEROS
from samba.auth import system_session, admin_session
from samba import Ldb, version
from ldb import SCOPE_ONELEVEL, SCOPE_SUBTREE, SCOPE_BASE,\
                FLAG_MOD_REPLACE, FLAG_MOD_ADD, FLAG_MOD_DELETE,\
                MessageElement, Message, Dn
from samba import param
from samba.misc import messageEltFlagToString
from samba.provision import find_setup_dir, get_domain_descriptor,\
                            get_config_descriptor, secretsdb_self_join,\
                            set_gpo_acl, getpolicypath,create_gpo_struct,\
                            ProvisioningError, getLastProvisionUSN,\
                            get_max_usn, updateProvisionUSN
from samba.schema import get_linked_attributes, Schema, get_schema_descriptor
from samba.dcerpc import security, drsblobs
from samba.ndr import ndr_unpack
from samba.dcerpc.misc import SEC_CHAN_BDC
from samba.upgradehelpers import dn_sort, get_paths, newprovision,\
                                 find_provision_key_parameters, get_ldbs,\
                                 usn_in_range, identic_rename, get_diff_sddls

replace=2**FLAG_MOD_REPLACE
add=2**FLAG_MOD_ADD
delete=2**FLAG_MOD_DELETE
never=0


# Will be modified during provision to tell if default sd has been modified
# somehow ...

#Errors are always logged
ERROR =     -1
SIMPLE =     0x00
CHANGE =     0x01
CHANGESD =     0x02
GUESS =     0x04
PROVISION =    0x08
CHANGEALL =    0xff

__docformat__ = "restructuredText"

# Attributes that are never copied from the reference provision (even if they
# do not exist in the destination object).
# This is most probably because they are populated automatcally when object is
# created
# This also apply to imported object from reference provision
hashAttrNotCopied = {   "dn": 1, "whenCreated": 1, "whenChanged": 1,
                        "objectGUID": 1, "uSNCreated": 1,
                        "replPropertyMetaData": 1, "uSNChanged": 1,
                        "parentGUID": 1, "objectCategory": 1,
                        "distinguishedName": 1, "nTMixedDomain": 1,
                        "showInAdvancedViewOnly": 1, "instanceType": 1,
                        "msDS-Behavior-Version":1, "nextRid":1, "cn": 1,
                        "versionNumber":1, "lmPwdHistory":1, "pwdLastSet": 1,
                        "ntPwdHistory":1, "unicodePwd":1,"dBCSPwd":1,
                        "supplementalCredentials":1, "gPCUserExtensionNames":1,
                        "gPCMachineExtensionNames":1,"maxPwdAge":1, "secret":1,
                        "possibleInferiors":1, "privilege":1,
                        "sAMAccountType":1 }

# Usually for an object that already exists we do not overwrite attributes as
# they might have been changed for good reasons. Anyway for a few of them it's
# mandatory to replace them otherwise the provision will be broken somehow.
# But for attribute that are just missing we do not have to specify them as the default
# behavior is to add missing attribute
hashOverwrittenAtt = {  "prefixMap": replace, "systemMayContain": replace,
                        "systemOnly":replace, "searchFlags":replace,
                        "mayContain":replace, "systemFlags":replace+add,
                        "description":replace, "operatingSystemVersion":replace,
                        "adminPropertyPages":replace, "groupType":replace,
                        "wellKnownObjects":replace, "privilege":never,
                        "defaultSecurityDescriptor": replace,
                        "rIDAvailablePool": never,
                        "defaultSecurityDescriptor": replace + add }


backlinked = []
forwardlinked = {}
dn_syntax_att = []
def define_what_to_log(opts):
    what = 0
    if opts.debugchange:
        what = what | CHANGE
    if opts.debugchangesd:
        what = what | CHANGESD
    if opts.debugguess:
        what = what | GUESS
    if opts.debugprovision:
        what = what | PROVISION
    if opts.debugall:
        what = what | CHANGEALL
    return what


parser = optparse.OptionParser("provision [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("--setupdir", type="string", metavar="DIR",
                  help="directory with setup files")
parser.add_option("--debugprovision", help="Debug provision", action="store_true")
parser.add_option("--debugguess", action="store_true",
                  help="Print information on what is different but won't be changed")
parser.add_option("--debugchange", action="store_true",
                  help="Print information on what is different but won't be changed")
parser.add_option("--debugchangesd", action="store_true",
                  help="Print information security descriptors differences")
parser.add_option("--debugall", action="store_true",
                  help="Print all available information (very verbose)")
parser.add_option("--full", action="store_true",
                  help="Perform full upgrade of the samdb (schema, configuration, new objects, ...")

opts = parser.parse_args()[0]

handler = logging.StreamHandler(sys.stdout)
upgrade_logger = logging.getLogger("upgradeprovision")
upgrade_logger.addHandler(handler)

provision_logger = logging.getLogger("provision")
provision_logger.addHandler(handler)

whatToLog = define_what_to_log(opts)

def message(what, text):
    """Print a message if this message type has been selected to be printed

    :param what: Category of the message
    :param text: Message to print """
    if (whatToLog & what) or what <= 0:
        upgrade_logger.info("%s", text)

if len(sys.argv) == 1:
    opts.interactive = True
lp = sambaopts.get_loadparm()
smbconf = lp.configfile

creds = credopts.get_credentials(lp)
creds.set_kerberos_state(DONT_USE_KERBEROS)
setup_dir = opts.setupdir
if setup_dir is None:
    setup_dir = find_setup_dir()



def check_for_DNS(refprivate, private):
    """Check if the provision has already the requirement for dynamic dns

    :param refprivate: The path to the private directory of the reference
                       provision
    :param private: The path to the private directory of the upgraded
                    provision"""

    spnfile = "%s/spn_update_list" % private
    namedfile = lp.get("dnsupdate:path")

    if not namedfile:
       namedfile = "%s/named.conf.update" % private

    if not os.path.exists(spnfile):
        shutil.copy("%s/spn_update_list" % refprivate, "%s" % spnfile)

    destdir = "%s/new_dns" % private
    dnsdir = "%s/dns" % private

    if not os.path.exists(namedfile):
        if not os.path.exists(destdir):
            os.mkdir(destdir)
        if not os.path.exists(dnsdir):
            os.mkdir(dnsdir)
        shutil.copy("%s/named.conf" % refprivate, "%s/named.conf" % destdir)
        shutil.copy("%s/named.txt" % refprivate, "%s/named.txt" % destdir)
        message(SIMPLE, "It seems that you provision didn't integrate new rules "
                "for dynamic dns update of domain related entries")
        message(SIMPLE, "A copy of the new bind configuration files and "
                "template as been put in %s, you should read them and configure dynamic "
                " dns update" % destdir)


def populate_links(samdb, schemadn):
    """Populate an array with all the back linked attributes

    This attributes that are modified automaticaly when
    front attibutes are changed

    :param samdb: A LDB object for sam.ldb file
    :param schemadn: DN of the schema for the partition"""
    linkedAttHash = get_linked_attributes(Dn(samdb, str(schemadn)), samdb)
    backlinked.extend(linkedAttHash.values())
    for t in linkedAttHash.keys():
        forwardlinked[t] = 1

def populate_dnsyntax(samdb, schemadn):
    """Populate an array with all the attributes that have DN synthax
       (oid 2.5.5.1)

    :param samdb: A LDB object for sam.ldb file
    :param schemadn: DN of the schema for the partition"""
    res = samdb.search(expression="(attributeSyntax=2.5.5.1)", base=Dn(samdb,
                        str(schemadn)), scope=SCOPE_SUBTREE,
                        attrs=["lDAPDisplayName"])
    for elem in res:
        dn_syntax_att.append(elem["lDAPDisplayName"])


def sanitychecks(samdb, names):
    """Make some checks before trying to update

    :param samdb: An LDB object opened on sam.ldb
    :param names: list of key provision parameters
    :return: Status of check (1 for Ok, 0 for not Ok) """
    res = samdb.search(expression="objectClass=ntdsdsa", base=str(names.configdn),
                         scope=SCOPE_SUBTREE, attrs=["dn"],
                         controls=["search_options:1:2"])
    if len(res) == 0:
        print "No DC found, your provision is most probably hardly broken !"
        return False
    elif len(res) != 1:
        print "Found %d domain controllers, for the moment upgradeprovision" \
              "is not able to handle upgrade on domain with more than one DC, please demote" \
              " the other(s) DC(s) before upgrading" % len(res)
        return False
    else:
        return True


def print_provision_key_parameters(names):
    """Do a a pretty print of provision parameters

    :param names: list of key provision parameters """
    message(GUESS, "rootdn      :" + str(names.rootdn))
    message(GUESS, "configdn    :" + str(names.configdn))
    message(GUESS, "schemadn    :" + str(names.schemadn))
    message(GUESS, "serverdn    :" + str(names.serverdn))
    message(GUESS, "netbiosname :" + names.netbiosname)
    message(GUESS, "defaultsite :" + names.sitename)
    message(GUESS, "dnsdomain   :" + names.dnsdomain)
    message(GUESS, "hostname    :" + names.hostname)
    message(GUESS, "domain      :" + names.domain)
    message(GUESS, "realm       :" + names.realm)
    message(GUESS, "invocationid:" + names.invocation)
    message(GUESS, "policyguid  :" + names.policyid)
    message(GUESS, "policyguiddc:" + str(names.policyid_dc))
    message(GUESS, "domainsid   :" + str(names.domainsid))
    message(GUESS, "domainguid  :" + names.domainguid)
    message(GUESS, "ntdsguid    :" + names.ntdsguid)
    message(GUESS, "domainlevel :" + str(names.domainlevel))


def handle_special_case(att, delta, new, old, usn):
    """Define more complicate update rules for some attributes

    :param att: The attribute to be updated
    :param delta: A messageElement object that correspond to the difference
                  between the updated object and the reference one
    :param new: The reference object
    :param old: The Updated object
    :param usn: The highest usn modified by a previous (upgrade)provision
    :return: True to indicate that the attribute should be kept, False for
             discarding it"""

    flag = delta.get(att).flags()
    # We do most of the special case handle if we do not have the
    # highest usn as otherwise the replPropertyMetaData will guide us more
    # correctly
    if usn == None:
        if (att == "member" and flag == FLAG_MOD_REPLACE):
            hash = {}
            newval = []
            changeDelta=0
            for elem in old[0][att]:
                hash[str(elem)]=1
                newval.append(str(elem))

            for elem in new[0][att]:
                if not hash.has_key(str(elem)):
                    changeDelta=1
                    newval.append(str(elem))
            if changeDelta == 1:
                delta[att] = MessageElement(newval, FLAG_MOD_REPLACE, att)
            else:
                delta.remove(att)
            return True

        if (att == "gPLink" or att == "gPCFileSysPath") and \
            flag == FLAG_MOD_REPLACE and\
            str(new[0].dn).lower() == str(old[0].dn).lower():
            delta.remove(att)
            return True

        if att == "forceLogoff":
            ref=0x8000000000000000
            oldval=int(old[0][att][0])
            newval=int(new[0][att][0])
            ref == old and ref == abs(new)
            return True

        if (att == "adminDisplayName" or att == "adminDescription"):
            return True

        if (str(old[0].dn) == "CN=Samba4-Local-Domain, %s" % (str(names.schemadn))\
            and att == "defaultObjectCategory" and flag == FLAG_MOD_REPLACE):
            return True

        if (str(old[0].dn) == "CN=Title, %s" % (str(names.schemadn)) and
                att == "rangeUpper" and flag == FLAG_MOD_REPLACE):
            return True

        if (str(old[0].dn) == "%s" % (str(names.rootdn))
                and att == "subRefs" and flag == FLAG_MOD_REPLACE):
            return True

        if str(delta.dn).endswith("CN=DisplaySpecifiers, %s" % names.configdn):
            return True

    # This is a bit of special animal as we might have added
    # already SPN entries to the list that has to be modified
    # So we go in detail to try to find out what has to be added ...
    if ( att == "servicePrincipalName" and flag == FLAG_MOD_REPLACE):
        hash = {}
        newval = []
        changeDelta=0
        for elem in old[0][att]:
            hash[str(elem)]=1
            newval.append(str(elem))

        for elem in new[0][att]:
            if not hash.has_key(str(elem)):
                changeDelta=1
                newval.append(str(elem))
        if changeDelta == 1:
            delta[att] = MessageElement(newval, FLAG_MOD_REPLACE, att)
        else:
            delta.remove(att)
        return True

    return False

def update_secrets(newsecrets_ldb, secrets_ldb):
    """Update secrets.ldb

    :param newsecrets_ldb: An LDB object that is connected to the secrets.ldb
                            of the reference provision
    :param secrets_ldb: An LDB object that is connected to the secrets.ldb
                            of the updated provision"""

    message(SIMPLE, "update secrets.ldb")
    reference = newsecrets_ldb.search(expression="dn=@MODULES", base="",
                                        scope=SCOPE_SUBTREE)
    current = secrets_ldb.search(expression="dn=@MODULES", base="",
                                        scope=SCOPE_SUBTREE)
    delta = secrets_ldb.msg_diff(current[0], reference[0])
    delta.dn = current[0].dn
    secrets_ldb.modify(delta)

    reference = newsecrets_ldb.search(expression="objectClass=top", base="",
                                        scope=SCOPE_SUBTREE, attrs=["dn"])
    current = secrets_ldb.search(expression="objectClass=top", base="",
                                        scope=SCOPE_SUBTREE, attrs=["dn"])
    hash_new = {}
    hash = {}
    listMissing = []
    listPresent = []

    empty = Message()
    for i in range(0, len(reference)):
        hash_new[str(reference[i]["dn"]).lower()] = reference[i]["dn"]

    # Create a hash for speeding the search of existing object in the
    # current provision
    for i in range(0, len(current)):
        hash[str(current[i]["dn"]).lower()] = current[i]["dn"]

    for k in hash_new.keys():
        if not hash.has_key(k):
            listMissing.append(hash_new[k])
        else:
            listPresent.append(hash_new[k])

    for entry in listMissing:
        reference = newsecrets_ldb.search(expression="dn=%s"%entry,base="", scope=SCOPE_SUBTREE)
        current = secrets_ldb.search(expression="dn=%s"%entry,base="", scope=SCOPE_SUBTREE)
        delta = secrets_ldb.msg_diff(empty,reference[0])
        for att in hashAttrNotCopied.keys():
            delta.remove(att)
        message(CHANGE, "Entry %s is missing from secrets.ldb"%reference[0].dn)
        for att in delta:
            message(CHANGE, " Adding attribute %s"%att)
        delta.dn = reference[0].dn
        secrets_ldb.add(delta)

    for entry in listPresent:
        reference = newsecrets_ldb.search(expression="dn=%s"%entry,base="", scope=SCOPE_SUBTREE)
        current = secrets_ldb.search(expression="dn=%s"%entry,base="", scope=SCOPE_SUBTREE)
        delta = secrets_ldb.msg_diff(current[0],reference[0])
        for att in hashAttrNotCopied.keys():
            delta.remove(att)
        for att in delta:
            if att == "name":
                message(CHANGE, "Found attribute name on  %s, must rename the DN "%(current[0].dn))
                identic_rename(secrets_ldb,reference[0].dn)
            else:
                delta.remove(att)

    for entry in listPresent:
        reference = newsecrets_ldb.search(expression="dn=%s"%entry,base="", scope=SCOPE_SUBTREE)
        current = secrets_ldb.search(expression="dn=%s"%entry,base="", scope=SCOPE_SUBTREE)
        delta = secrets_ldb.msg_diff(current[0],reference[0])
        for att in hashAttrNotCopied.keys():
            delta.remove(att)
        for att in delta:
            if att != "dn":
                message(CHANGE, " Adding/Changing attribute %s to %s"%(att,current[0].dn))

        delta.dn = current[0].dn
        secrets_ldb.modify(delta)


def dump_denied_change(dn, att, flagtxt, current, reference):
    """Print detailed information about why a changed is denied

    :param dn: DN of the object which attribute is denied
    :param att: Attribute that was supposed to be upgraded
    :param flagtxt: Type of the update that should be performed
                    (add, change, remove, ...)
    :param current: Value(s) of the current attribute
    :param reference: Value(s) of the reference attribute"""

    message(CHANGE, "dn= " + str(dn)+" " + att+" with flag " + flagtxt
                +" is not allowed to be changed/removed, I discard this change")
    if att != "objectSid" :
        i = 0
        for e in range(0, len(current)):
            message(CHANGE, "old %d : %s" % (i, str(current[e])))
            i+=1
        if reference != None:
            i = 0
            for e in range(0, len(reference)):
                message(CHANGE, "new %d : %s" % (i, str(reference[e])))
                i+=1
    else:
        message(CHANGE, "old : %s" % str(ndr_unpack( security.dom_sid, current[0])))
        message(CHANGE, "new : %s" % str(ndr_unpack( security.dom_sid, reference[0])))


def handle_special_add(samdb, dn, names):
    """Handle special operation (like remove) on some object needed during
       upgrade

    This is mostly due to wrong creation of the object in previous provision.
    :param samdb: An Ldb object representing the SAM database
    :param dn: DN of the object to inspect
    :param names: list of key provision parameters"""

    dntoremove = None
    if str(dn).lower() == ("CN=IIS_IUSRS, CN=Builtin, %s" % names.rootdn).lower():
        #This entry was misplaced lets remove it if it exists
        dntoremove = "CN=IIS_IUSRS, CN=Users, %s" % names.rootdn

    objname = "CN=Certificate Service DCOM Access, CN=Builtin, %s" % names.rootdn
    if str(dn).lower() == objname.lower():
        #This entry was misplaced lets remove it if it exists
        dntoremove = "CN=Certificate Service DCOM Access,"\
                     "CN=Users, %s" % names.rootdn

    objname = "CN=Cryptographic Operators, CN=Builtin, %s" % names.rootdn
    if str(dn).lower() == objname.lower():
        #This entry was misplaced lets remove it if it exists
        dntoremove = "CN=Cryptographic Operators, CN=Users, %s" % names.rootdn

    objname = "CN=Event Log Readers, CN=Builtin, %s" % names.rootdn
    if str(dn).lower() == objname.lower():
        #This entry was misplaced lets remove it if it exists
        dntoremove = "CN=Event Log Readers, CN=Users, %s" % names.rootdn

    if dntoremove != None:
        res = samdb.search(expression="(dn=%s)" % dntoremove,
                            base=str(names.rootdn),
                            scope=SCOPE_SUBTREE, attrs=["dn"],
                            controls=["search_options:1:2"])
        if len(res) > 0:
            message(CHANGE, "Existing object %s must be replaced by %s,"\
                            "removing old object" % (dntoremove, str(dn)))
            samdb.delete(res[0]["dn"])


def check_dn_nottobecreated(hash, index, listdn):
    """Check if one of the DN present in the list has a creation order
       greater than the current.

    Hash is indexed by dn to be created, with each key
    is associated the creation order.

    First dn to be created has the creation order 0, second has 1, ...
    Index contain the current creation order

    :param hash: Hash holding the different DN of the object to be
                  created as key
    :param index: Current creation order
    :param listdn: List of DNs on which the current DN depends on
    :return: None if the current object do not depend on other
              object or if all object have been created before."""
    if listdn == None:
        return None
    for dn in listdn:
        key = str(dn).lower()
        if hash.has_key(key) and hash[key] > index:
            return str(dn)
    return None



def add_missing_object(ref_samdb, samdb, dn, names, basedn, hash, index):
    """Add a new object if the dependencies are satisfied

    The function add the object if the object on which it depends are already
    created

    :param ref_samdb: Ldb object representing the SAM db of the reference
                       provision
    :param samdb: Ldb object representing the SAM db of the upgraded
                   provision
    :param dn: DN of the object to be added
    :param names: List of key provision parameters
    :param basedn: DN of the partition to be updated
    :param hash: Hash holding the different DN of the object to be
                  created as key
    :param index: Current creation order
    :return: True if the object was created False otherwise"""

    handle_special_add(samdb, dn, names)
    reference = ref_samdb.search(expression="dn=%s" % (str(dn)), base=basedn,
                    scope=SCOPE_SUBTREE, controls=["search_options:1:2"])
    empty = Message()
    delta = samdb.msg_diff(empty, reference[0])
    delta.dn
    for att in hashAttrNotCopied.keys():
        delta.remove(att)
    for att in backlinked:
        delta.remove(att)
    depend_on_yettobecreated = None
    for att in dn_syntax_att:
        depend_on_yet_tobecreated = check_dn_nottobecreated(hash, index,
                                                            delta.get(str(att)))
        if depend_on_yet_tobecreated != None:
            message(CHANGE, "Object %s depends on %s in attribute %s," \
                            "delaying the creation" % (str(dn), \
                                      depend_on_yet_tobecreated, str(att)))
            return False

    delta.dn = dn
    message(CHANGE,"Object %s will be added" % dn)
    samdb.add(delta, ["relax:0"])
    return True

def gen_dn_index_hash(listMissing):
    """Generate a hash associating the DN to its creation order

    :param listMissing: List of DN
    :return: Hash with DN as keys and creation order as values"""
    hash = {}
    for i in range(0, len(listMissing)):
        hash[str(listMissing[i]).lower()] = i
    return hash

def add_deletedobj_containers(ref_samdb, samdb, names):
    """Add the object containter: CN=Deleted Objects

    This function create the container for each partition that need one and
    then reference the object into the root of the partition

    :param ref_samdb: Ldb object representing the SAM db of the reference
                       provision
    :param samdb: Ldb object representing the SAM db of the upgraded provision
    :param names: List of key provision parameters"""


    wkoPrefix = "B:32:18E2EA80684F11D2B9AA00C04F79F805"
    partitions = [str(names.rootdn), str(names.configdn)]
    for part in partitions:
        ref_delObjCnt = ref_samdb.search(expression="(cn=Deleted Objects)",
                                            base=part, scope=SCOPE_SUBTREE,
                                            attrs=["dn"],
                                            controls=["show_deleted:0"])
        delObjCnt = samdb.search(expression="(cn=Deleted Objects)",
                                    base=part, scope=SCOPE_SUBTREE,
                                    attrs=["dn"],
                                    controls=["show_deleted:0"])
        if len(ref_delObjCnt) > len(delObjCnt):
            reference = ref_samdb.search(expression="cn=Deleted Objects",
                                            base=part, scope=SCOPE_SUBTREE,
                                            controls=["show_deleted:0"])
            empty = Message()
            delta = samdb.msg_diff(empty, reference[0])

            delta.dn = Dn(samdb, str(reference[0]["dn"]))
            for att in hashAttrNotCopied.keys():
                delta.remove(att)
            samdb.add(delta)

            listwko = []
            res = samdb.search(expression="(objectClass=*)", base=part,
                               scope=SCOPE_BASE,
                               attrs=["dn", "wellKnownObjects"])

            targetWKO = "%s:%s" % (wkoPrefix, str(reference[0]["dn"]))
            found = 0

            if len(res[0]) > 0:
                wko = res[0]["wellKnownObjects"]

                # The wellKnownObject that we want to add.
                for o in wko:
                    if str(o) == targetWKO:
                        found = 1
                    listwko.append(str(o))

            if not found:
                listwko.append(targetWKO)

                delta = Message()
                delta.dn = Dn(samdb, str(res[0]["dn"]))
                delta["wellKnownObjects"] = MessageElement(listwko,
                                                FLAG_MOD_REPLACE,
                                                "wellKnownObjects" )
                samdb.modify(delta)

def add_missing_entries(ref_samdb, samdb, names, basedn, list):
    """Add the missing object whose DN is the list

    The function add the object if the objects on which it depends are
    already created.

    :param ref_samdb: Ldb object representing the SAM db of the reference
                      provision
    :param samdb: Ldb object representing the SAM db of the upgraded
                  provision
    :param dn: DN of the object to be added
    :param names: List of key provision parameters
    :param basedn: DN of the partition to be updated
    :param list: List of DN to be added in the upgraded provision"""

    listMissing = []
    listDefered = list

    while(len(listDefered) != len(listMissing) and len(listDefered) > 0):
        index = 0
        listMissing = listDefered
        listDefered = []
        hashMissing = gen_dn_index_hash(listMissing)
        for dn in listMissing:
            ret = add_missing_object(ref_samdb, samdb, dn, names, basedn,
                                        hashMissing, index)
            index = index + 1
            if ret == 0:
                # DN can't be created because it depends on some
                # other DN in the list
                listDefered.append(dn)
    if len(listDefered) != 0:
        raise ProvisioningError("Unable to insert missing elements:" \
                                "circular references")

def handle_links(samdb, att, basedn, dn, value, ref_value, delta):
    """This function handle updates on links

    :param samdb: An LDB object pointing to the updated provision
    :param att: Attribute to update
    :param basedn: The root DN of the provision
    :param dn: The DN of the inspected object
    :param value: The value of the attribute
    :param ref_value: The value of this attribute in the reference provision
    :param delta: The MessageElement object that will be applied for
                   transforming the current provision"""

    res = samdb.search(expression="dn=%s" % dn, base=basedn,
                        controls=["search_options:1:2", "reveal:1"],
                        attrs=[att])

    blacklist = {}
    hash = {}
    newlinklist = []
    changed = 0

    newlinklist.extend(value)

    for e in value:
        hash[e] = 1
    # for w2k domain level the reveal won't reveal anything ...
    # it means that we can readd links that were removed on purpose ...
    # Also this function in fact just accept add not removal

    for e in res[0][att]:
        if not hash.has_key(e):
            # We put in the blacklist all the element that are in the "revealed"
            # result and not in the "standard" result
            # This element are links that were removed before and so that
            # we don't wan't to readd
            blacklist[e] = 1

    for e in ref_value:
        if not blacklist.has_key(e) and not hash.has_key(e):
            newlinklist.append(str(e))
            changed = 1
    if changed:
        delta[att] = MessageElement(newlinklist, FLAG_MOD_REPLACE, att)
    else:
        delta.remove(att)

def update_present(ref_samdb, samdb, basedn, listPresent, usns, invocationid):
    """ This function updates the object that are already present in the
        provision

    :param ref_samdb: An LDB object pointing to the reference provision
    :param samdb: An LDB object pointing to the updated provision
    :param basedn: A string with the value of the base DN for the provision
                   (ie. DC=foo, DC=bar)
    :param listPresent: A list of object that is present in the provision
    :param usns: A list of USN range modified by previous provision and
                 upgradeprovision
    :param invocationid: The value of the invocationid for the current DC"""

    global defSDmodified
    # This hash is meant to speedup lookup of attribute name from an oid,
    # it's for the replPropertyMetaData handling
    hash_oid_name = {}
    res = samdb.search(expression="objectClass=attributeSchema", base=basedn,
                        controls=["search_options:1:2"], attrs=["attributeID",
                        "lDAPDisplayName"])
    if len(res) > 0:
        for e in res:
            strDisplay = str(e.get("lDAPDisplayName"))
            hash_oid_name[str(e.get("attributeID"))] = strDisplay
    else:
        msg = "Unable to insert missing elements: circular references"
        raise ProvisioningError(msg)

    changed = 0
    controls = ["search_options:1:2", "sd_flags:1:2"]
    for dn in listPresent:
        reference = ref_samdb.search(expression="dn=%s" % (str(dn)), base=basedn,
                                        scope=SCOPE_SUBTREE,
                                        controls=controls)
        current = samdb.search(expression="dn=%s" % (str(dn)), base=basedn,
                                scope=SCOPE_SUBTREE, controls=controls)

        if (
             (str(current[0].dn) != str(reference[0].dn)) and
             (str(current[0].dn).upper() == str(reference[0].dn).upper())
           ):
            message(CHANGE, "Name are the same but case change,"\
                            "let's rename %s to %s" % (str(current[0].dn),
                                                       str(reference[0].dn)))
            identic_rename(samdb, reference[0].dn)
            current = samdb.search(expression="dn=%s" % (str(dn)), base=basedn,
                                    scope=SCOPE_SUBTREE,
                                    controls=["search_options:1:2"])

        delta = samdb.msg_diff(current[0], reference[0])

        for att in hashAttrNotCopied.keys():
            delta.remove(att)

        for att in backlinked:
            delta.remove(att)

        delta.remove("name")

        if len(delta.items()) > 1 and usns != None:
            # Fetch the replPropertyMetaData
            res = samdb.search(expression="dn=%s" % (str(dn)), base=basedn,
                                scope=SCOPE_SUBTREE, controls=controls,
                                attrs=["replPropertyMetaData"])
            ctr = ndr_unpack(drsblobs.replPropertyMetaDataBlob,
                                str(res[0]["replPropertyMetaData"])).ctr

            hash_attr_usn = {}
            for o in ctr.array:
                # We put in this hash only modification
                # made on the current host
                att = hash_oid_name[samdb.get_oid_from_attid(o.attid)]
                if str(o.originating_invocation_id) == str(invocationid):
                # Note we could just use 1 here
                    hash_attr_usn[att] = o.originating_usn
                else:
                    hash_attr_usn[att] = -1

        isFirst = 0
        txt = ""

        for att in delta:
            if usns != None:
                # We have updated by provision usn information so let's exploit
                # replMetadataProperties
                if forwardlinked.has_key(att):
                    handle_links(samdb, att, basedn, current[0]["dn"],
                                    current[0][att], reference[0][att], delta)

                if isFirst == 0 and len(delta.items())>1:
                    isFirst = 1
                    txt = "%s\n" % (str(dn))
                if att == "dn":
                    # There is always a dn attribute after a msg_diff
                    continue
                if att == "rIDAvailablePool":
                    delta.remove(att)
                    continue
                if att == "objectSid":
                    delta.remove(att)
                    continue
                if att == "creationTime":
                    delta.remove(att)
                    continue
                if att == "oEMInformation":
                    delta.remove(att)
                    continue
                if att == "msDs-KeyVersionNumber":
                # This is the kvno of the computer/user it's a very bad
                # idea to change it
                    delta.remove(att)
                    continue
                if handle_special_case(att, delta, reference, current, usns):
                    # This attribute is "complicated" to handle and handling
                    # was done in handle_special_case
                    continue
                attrUSN = hash_attr_usn.get(att)
                if att == "forceLogoff" and attrUSN == None:
                    continue
                if  attrUSN == None:
                    delta.remove(att)
                    continue

                if attrUSN == -1:
                    # This attribute was last modified by another DC forget
                    # about it
                    message(CHANGE, "%sAttribute: %s has been" \
                            "created/modified/deleted  by another DC,"
                            " do nothing" % (txt, att ))
                    txt = ""
                    delta.remove(att)
                    continue
                elif usn_in_range(int(attrUSN), usns) == 0:
                    message(CHANGE, "%sAttribute: %s has been" \
                                    "created/modified/deleted not during a" \
                                    " provision or upgradeprovision: current" \
                                    " usn %d , do nothing" % (txt, att, attrUSN))
                    txt = ""
                    delta.remove(att)
                    continue
                else:
                    if att == "defaultSecurityDescriptor":
                        defSDmodified = 1
                    if attrUSN:
                        message(CHANGE, "%sAttribute: %s will be modified" \
                                        "/deleted it was last modified" \
                                        "during a provision, current usn:" \
                                        "%d" % (txt, att,  attrUSN))
                        txt = ""
                    else:
                        message(CHANGE, "%sAttribute: %s will be added because" \
                                        " it hasn't existed before " % (txt, att))
                        txt = ""
                    continue

            else:
            # Old school way of handling things for pre alpha12 upgrade
                defSDmodified = 1
                msgElt = delta.get(att)

                if att == "nTSecurityDescriptor":
                    delta.remove(att)
                    continue

                if att == "dn":
                    continue

                if not hashOverwrittenAtt.has_key(att):
                    if msgElt.flags() != FLAG_MOD_ADD:
                        if not handle_special_case(att, delta, reference, current,
                                                    usns):
                            if opts.debugchange or opts.debugall:
                                try:
                                    dump_denied_change(dn, att,
                                        messageEltFlagToString(msgElt.flags()),
                                        current[0][att], reference[0][att])
                                except KeyError:
                                    dump_denied_change(dn, att,
                                        messageEltFlagToString(msgElt.flags()),
                                        current[0][att], None)
                            delta.remove(att)
                        continue
                else:
                    if hashOverwrittenAtt.get(att)&2**msgElt.flags() :
                        continue
                    elif  hashOverwrittenAtt.get(att)==never:
                        delta.remove(att)
                        continue

        delta.dn = dn
        if len(delta.items()) >1:
            attributes=", ".join(delta.keys())
            message(CHANGE, "%s is different from the reference one, changed" \
                            " attributes: %s\n" % (dn, attributes))
            changed = changed + 1
            samdb.modify(delta)
    return changed

def update_partition(ref_samdb, samdb, basedn, names, schema, provisionUSNs):
    """Check differences between the reference provision and the upgraded one.

    It looks for all objects which base DN is name.

    This function will also add the missing object and update existing object
    to add or remove attributes that were missing.

    :param ref_sambdb: An LDB object conntected to the sam.ldb of the
                       reference provision
    :param samdb: An LDB object connected to the sam.ldb of the update
                  provision
    :param basedn: String value of the DN of the partition
    :param names: List of key provision parameters
    :param schema: A Schema object
    :param provisionUSNs:  The USNs modified by provision/upgradeprovision
                           last time"""

    hash_new = {}
    hash = {}
    listMissing = []
    listPresent = []
    reference = []
    current = []

    # Connect to the reference provision and get all the attribute in the
    # partition referred by name
    reference = ref_samdb.search(expression="objectClass=*", base=basedn,
                                    scope=SCOPE_SUBTREE, attrs=["dn"],
                                    controls=["search_options:1:2"])

    current = samdb.search(expression="objectClass=*", base=basedn,
                                scope=SCOPE_SUBTREE, attrs=["dn"],
                                controls=["search_options:1:2"])
    # Create a hash for speeding the search of new object
    for i in range(0, len(reference)):
        hash_new[str(reference[i]["dn"]).lower()] = reference[i]["dn"]

    # Create a hash for speeding the search of existing object in the
    # current provision
    for i in range(0, len(current)):
        hash[str(current[i]["dn"]).lower()] = current[i]["dn"]


    for k in hash_new.keys():
        if not hash.has_key(k):
            if not str(hash_new[k]) == "CN=Deleted Objects, %s" % names.rootdn:
                listMissing.append(hash_new[k])
        else:
            listPresent.append(hash_new[k])

    # Sort the missing object in order to have object of the lowest level
    # first (which can be containers for higher level objects)
    listMissing.sort(dn_sort)
    listPresent.sort(dn_sort)

    # The following lines is to load the up to
    # date schema into our current LDB
    # a complete schema is needed as the insertion of attributes
    # and class is done against it
    # and the schema is self validated
    samdb.set_schema_from_ldb(schema.ldb)
    try:
        message(SIMPLE, "There are %d missing objects" % (len(listMissing)))
        add_deletedobj_containers(ref_samdb, samdb, names)

        add_missing_entries(ref_samdb, samdb, names, basedn, listMissing)
        changed = update_present(ref_samdb, samdb, basedn, listPresent,
                                    provisionUSNs, names.invocation)
        message(SIMPLE, "There are %d changed objects" % (changed))
        return 1

    except StandardError, err:
        message(ERROR, "Exception during upgrade of samdb:")
        (typ, val, tb) = sys.exc_info()
        traceback.print_exception(typ, val, tb)
        return 0



def check_updated_sd(ref_sam, cur_sam, names):
    """Check if the security descriptor in the upgraded provision are the same
       as the reference

    :param ref_sam: A LDB object connected to the sam.ldb file used as
                    the reference provision
    :param cur_sam: A LDB object connected to the sam.ldb file used as
                    upgraded provision
    :param names: List of key provision parameters"""
    reference = ref_sam.search(expression="objectClass=*", base=str(names.rootdn),
                                scope=SCOPE_SUBTREE,
                                attrs=["dn", "nTSecurityDescriptor"],
                                controls=["search_options:1:2"])
    current = cur_sam.search(expression="objectClass=*", base=str(names.rootdn),
                                scope=SCOPE_SUBTREE,
                                attrs=["dn", "nTSecurityDescriptor"],
                                controls=["search_options:1:2"])
    hash = {}
    for i in range(0, len(reference)):
        refsd = ndr_unpack(security.descriptor,
                    str(reference[i]["nTSecurityDescriptor"]))
        hash[str(reference[i]["dn"]).lower()] = refsd.as_sddl(names.domainsid)

    for i in range(0, len(current)):
        key = str(current[i]["dn"]).lower()
        if hash.has_key(key):
            cursd = ndr_unpack(security.descriptor,
                        str(current[i]["nTSecurityDescriptor"]))
            sddl = cursd.as_sddl(names.domainsid)
            if sddl != hash[key]:
                txt = get_diff_sddls(hash[key], sddl)
                if txt != "":
                    message(CHANGESD, "On object %s ACL is different"\
                                      " \n%s" % (current[i]["dn"], txt))



def fix_partition_sd(samdb, names):
    """This function fix the SD for partition containers (basedn, configdn, ...)
    This is needed because some provision use to have broken SD on containers

    :param samdb: An LDB object pointing to the sam of the current provision
    :param names: A list of key provision parameters
    """
    # First update the SD for the rootdn
    res = samdb.search(expression="objectClass=*", base=str(names.rootdn),
                         scope=SCOPE_BASE, attrs=["dn", "whenCreated"],
                         controls=["search_options:1:2"])
    delta = Message()
    delta.dn = Dn(samdb, str(res[0]["dn"]))
    descr = get_domain_descriptor(names.domainsid)
    delta["nTSecurityDescriptor"] = MessageElement(descr, FLAG_MOD_REPLACE,
                                                    "nTSecurityDescriptor")
    samdb.modify(delta, ["recalculate_sd:0"])
    # Then the config dn
    res = samdb.search(expression="objectClass=*", base=str(names.configdn),
                        scope=SCOPE_BASE, attrs=["dn", "whenCreated"],
                        controls=["search_options:1:2"])
    delta = Message()
    delta.dn = Dn(samdb, str(res[0]["dn"]))
    descr = get_config_descriptor(names.domainsid)
    delta["nTSecurityDescriptor"] = MessageElement(descr, FLAG_MOD_REPLACE,
                                                    "nTSecurityDescriptor" )
    samdb.modify(delta, ["recalculate_sd:0"])
    # Then the schema dn
    res = samdb.search(expression="objectClass=*", base=str(names.schemadn),
                        scope=SCOPE_BASE, attrs=["dn", "whenCreated"],
                        controls=["search_options:1:2"])

    delta = Message()
    delta.dn = Dn(samdb, str(res[0]["dn"]))
    descr = get_schema_descriptor(names.domainsid)
    delta["nTSecurityDescriptor"] = MessageElement(descr, FLAG_MOD_REPLACE,
                                                    "nTSecurityDescriptor" )
    samdb.modify(delta, ["recalculate_sd:0"])

def rebuild_sd(samdb, names):
    """Rebuild security descriptor of the current provision from scratch

    During the different pre release of samba4 security descriptors (SD)
    were notarly broken (up to alpha11 included)
    This function allow to get them back in order, this function make the
    assumption that nobody has modified manualy an SD
    and so SD can be safely recalculated from scratch to get them right.

    :param names: List of key provision parameters"""


    hash = {}
    res = samdb.search(expression="objectClass=*", base=str(names.rootdn),
                        scope=SCOPE_SUBTREE, attrs=["dn", "whenCreated"],
                        controls=["search_options:1:2"])
    for obj in res:
        if not (str(obj["dn"]) == str(names.rootdn) or
            str(obj["dn"]) == str(names.configdn) or \
            str(obj["dn"]) == str(names.schemadn)):
            hash[str(obj["dn"])] = obj["whenCreated"]

    listkeys = hash.keys()
    listkeys.sort(dn_sort)

    for key in listkeys:
        try:
            delta = Message()
            delta.dn = Dn(samdb, key)
            delta["whenCreated"] = MessageElement(hash[key], FLAG_MOD_REPLACE,
                                                    "whenCreated" )
            samdb.modify(delta, ["recalculate_sd:0"])
        except:
            # XXX: We should always catch an explicit exception.
            # What could go wrong here?
            samdb.transaction_cancel()
            res = samdb.search(expression="objectClass=*", base=str(names.rootdn),
                                scope=SCOPE_SUBTREE,
                                attrs=["dn", "nTSecurityDescriptor"],
                                controls=["search_options:1:2"])
            badsd = ndr_unpack(security.descriptor,
                        str(res[0]["nTSecurityDescriptor"]))
            print "bad stuff %s"%badsd.as_sddl(names.domainsid)
            return

def removeProvisionUSN(samdb):
        attrs = [samba.provision.LAST_PROVISION_USN_ATTRIBUTE, "dn"]
        entry = samdb.search(expression="dn=@PROVISION", base = "",
                                scope=SCOPE_SUBTREE,
                                controls=["search_options:1:2"],
                                attrs=attrs)
        empty = Message()
        empty.dn = entry[0].dn
        delta = samdb.msg_diff(entry[0], empty)
        delta.remove("dn")
        delta.dn = entry[0].dn
        samdb.modify(delta)

def delta_update_basesamdb(refpaths, paths, creds, session, lp):
    """Update the provision container db: sam.ldb
    This function is aimed for alpha9 and newer;

    :param refpaths: An object holding the different importants paths for
                     reference provision object
    :param paths: An object holding the different importants paths for
                  upgraded provision object
    :param creds: Credential used for openning LDB files
    :param session: Session to use for openning LDB files
    :param lp: A loadparam object"""

    message(SIMPLE,
            "Update base samdb by searching difference with reference one")
    refsam = Ldb(refpaths.samdb, session_info=session, credentials=creds,
                    lp=lp, options=["modules:"])
    sam = Ldb(paths.samdb, session_info=session, credentials=creds, lp=lp,
                options=["modules:"])

    empty = Message()

    reference = refsam.search(expression="")

    for refentry in reference:
        entry = sam.search(expression="dn=%s" % refentry["dn"],
                            scope=SCOPE_SUBTREE)
        if not len(entry):
            message(CHANGE, "Adding %s to sam db" % str(delta.dn))
            delta = sam.msg_diff(empty, refentry)
            if str(refentry.dn) == "@PROVISION" and\
                delta.get(samba.provision.LAST_PROVISION_USN_ATTRIBUTE):
                delta.remove(samba.provision.LAST_PROVISION_USN_ATTRIBUTE)
            delta.dn = refentry.dn
            sam.add(delta)
        else:
            delta = sam.msg_diff(entry[0], refentry)
            if str(refentry.dn) == "@PROVISION" and\
                delta.get(samba.provision.LAST_PROVISION_USN_ATTRIBUTE):
                delta.remove(samba.provision.LAST_PROVISION_USN_ATTRIBUTE)
            if len(delta.items()) > 1:
                delta.dn = refentry.dn
                sam.modify(delta)


def simple_update_basesamdb(newpaths, paths, names):
    """Update the provision container db: sam.ldb
    This function is aimed at very old provision (before alpha9)

    :param newpaths: List of paths for different provision objects
                        from the reference provision
    :param paths: List of paths for different provision objects
                        from the upgraded provision
    :param names: List of key provision parameters"""

    message(SIMPLE, "Copy samdb")
    shutil.copy(newpaths.samdb, paths.samdb)

    message(SIMPLE, "Update partitions filename if needed")
    schemaldb = os.path.join(paths.private_dir, "schema.ldb")
    configldb = os.path.join(paths.private_dir, "configuration.ldb")
    usersldb = os.path.join(paths.private_dir, "users.ldb")
    samldbdir = os.path.join(paths.private_dir, "sam.ldb.d")

    if not os.path.isdir(samldbdir):
        os.mkdir(samldbdir)
        os.chmod(samldbdir, 0700)
    if os.path.isfile(schemaldb):
        shutil.copy(schemaldb, os.path.join(samldbdir,
                                            "%s.ldb"%str(names.schemadn).upper()))
        os.remove(schemaldb)
    if os.path.isfile(usersldb):
        shutil.copy(usersldb, os.path.join(samldbdir,
                                            "%s.ldb"%str(names.rootdn).upper()))
        os.remove(usersldb)
    if os.path.isfile(configldb):
        shutil.copy(configldb, os.path.join(samldbdir,
                                            "%s.ldb"%str(names.configdn).upper()))
        os.remove(configldb)


def update_privilege(ref_private_path, cur_private_path):
    """Update the privilege database

    :param ref_private_path: Path to the private directory of the reference
                             provision.
    :param cur_private_path: Path to the private directory of the current
                             (and to be updated) provision."""
    message(SIMPLE, "Copy privilege")
    shutil.copy(os.path.join(ref_private_path, "privilege.ldb"),
                os.path.join(cur_private_path, "privilege.ldb"))


def update_samdb(ref_samdb, samdb, names, highestUSN, schema):
    """Upgrade the SAM DB contents for all the provision partitions

    :param ref_sambdb: An LDB object conntected to the sam.ldb of the reference
                       provision
    :param samdb: An LDB object connected to the sam.ldb of the update
                  provision
    :param names: List of key provision parameters
    :param highestUSN:  The highest USN modified by provision/upgradeprovision
                        last time
    :param schema: A Schema object that represent the schema of the provision"""

    message(SIMPLE, "Starting update of samdb")
    ret = update_partition(ref_samdb, samdb, str(names.rootdn), names,
                            schema, highestUSN)
    if ret:
        message(SIMPLE, "Update of samdb finished")
        return 1
    else:
        message(SIMPLE, "Update failed")
        return 0


def update_machine_account_password(samdb, secrets_ldb, names):
    """Update (change) the password of the current DC both in the SAM db and in
       secret one

    :param samdb: An LDB object related to the sam.ldb file of a given provision
    :param secrets_ldb: An LDB object related to the secrets.ldb file of a given
                        provision
    :param names: List of key provision parameters"""

    message(SIMPLE, "Update machine account")
    expression = "samAccountName=%s$" % names.netbiosname
    secrets_msg = secrets_ldb.search(expression=expression,
                                        attrs=["secureChannelType"])
    if int(secrets_msg[0]["secureChannelType"][0]) == SEC_CHAN_BDC:
        res = samdb.search(expression=expression, attrs=[])
        assert(len(res) == 1)

        msg = Message(res[0].dn)
        machinepass = samba.generate_random_password(128, 255)
        msg["userPassword"] = MessageElement(machinepass, FLAG_MOD_REPLACE,
                                                "userPassword")
        samdb.modify(msg)

        res = samdb.search(expression=("samAccountName=%s$" % names.netbiosname),
                     attrs=["msDs-keyVersionNumber"])
        assert(len(res) == 1)
        kvno = int(str(res[0]["msDs-keyVersionNumber"]))
        secChanType = int(secrets_msg[0]["secureChannelType"][0])

        secretsdb_self_join(secrets_ldb, domain=names.domain,
                    realm=names.realm or sambaopts._lp.get('realm'),
                    domainsid=names.domainsid,
                    dnsdomain=names.dnsdomain,
                    netbiosname=names.netbiosname,
                    machinepass=machinepass,
                    key_version_number=kvno,
                    secure_channel_type=secChanType)
    else:
        raise ProvisioningError("Unable to find a Secure Channel" \
                                "of type SEC_CHAN_BDC")


def update_gpo(paths, creds, session, names):
    """Create missing GPO file object if needed

    Set ACL correctly also.
    """
    dir = getpolicypath(paths.sysvol, names.dnsdomain, names.policyid)
    if not os.path.isdir(dir):
        create_gpo_struct(dir)

    dir = getpolicypath(paths.sysvol, names.dnsdomain, names.policyid_dc)
    if not os.path.isdir(dir):
        create_gpo_struct(dir)
    samdb = Ldb(paths.samdb, session_info=session, credentials=creds, lp=lp)
    set_gpo_acl(paths.sysvol, names.dnsdomain, names.domainsid,
        names.domaindn, samdb, lp)


def getOEMInfo(samdb, rootdn):
    """Return OEM Information on the top level
    Samba4 use to store version info in this field

    :param samdb: An LDB object connect to sam.ldb
    :param rootdn: Root DN of the domain
    :return: The content of the field oEMInformation (if any)"""
    res = samdb.search(expression="(objectClass=*)", base=str(rootdn),
                            scope=SCOPE_BASE, attrs=["dn", "oEMInformation"])
    if len(res) > 0:
        info = res[0]["oEMInformation"]
        return info
    else:
        return ""

def updateOEMInfo(samdb, names):
    res = samdb.search(expression="(objectClass=*)", base=str(names.rootdn),
                            scope=SCOPE_BASE, attrs=["dn", "oEMInformation"])
    if len(res) > 0:
        info = res[0]["oEMInformation"]
        info = "%s, upgrade to %s" % (info, version)
        delta = Message()
        delta.dn = Dn(samdb, str(res[0]["dn"]))
        delta["oEMInformation"] = MessageElement(info, FLAG_MOD_REPLACE,
            "oEMInformation" )
        samdb.modify(delta)


def setup_path(file):
    return os.path.join(setup_dir, file)

# Synopsis for updateprovision
# 1) get path related to provision to be update (called current)
# 2) open current provision ldbs
# 3) fetch the key provision parameter (domain sid, domain guid, invocationid
#    of the DC ....)
# 4) research of lastProvisionUSN in order to get ranges of USN modified
#    by either upgradeprovision or provision
# 5) creation of a new provision the latest version of provision script
#    (called reference)
# 6) get reference provision paths
# 7) open reference provision ldbs
# 8) setup helpers data that will help the update process
# 9) update the privilege ldb by copying the one of referecence provision to
#    the current provision
# 10)get the oemInfo field, this field contains information about the different
#    provision that have been done
# 11)Depending  on whether oemInfo has the string "alpha9" or alphaxx (x as an
#    integer) or none of this the following things are done
#    A) When alpha9 or alphaxx is present
#       The base sam.ldb file is updated by looking at the difference between
#       referrence one and the current one. Everything is copied with the
#       exception of lastProvisionUSN attributes. The highest used USN
#       is fetched so that changed by upgradeprovision usn can be tracked
#    B) Other case (it reflect that that provision was done before alpha9)
#       The base sam.ldb of the reference provision is copied over
#       the current one, if necessary ldb related to partitions are moved
#       and renamed
# 12)A Schema object is created, it will be used to provide a complete
#    schema to current provision during update (as the schema of the
#    current provision might not be complete and so won't allow some
#    object to be created)
# 13)Proceed to full update of sam DB (see the separate paragraph about i)
# 14)The secrets db is updated by pull all the difference from the reference
#    provision into the current provision
# 15)As the previous step has most probably modified the password stored in
#    in secret for the current DC, a new password is generated,
#    the kvno is bumped and the entry in samdb is also updated
# 16)For current provision older than alpha9, we must fix the SD a little bit
#    administrator to update them because SD used to be generated with the
#    system account before alpha9.
# 17)The highest usn modified so far is searched in the database it will be
#    the upper limit for usn modified during provision.
#    This is done before potential SD recalculation because we do not want
#    SD modified during recalculation to be marked as modified during provision
#    (and so possibly remplaced at next upgradeprovision)
# 18)Rebuilt SD if the flag indicate to do so
# 19)Check difference between SD of reference provision and those of the
#    current provision. The check is done by getting the sddl representation
#    of the SD. Each sddl in chuncked into parts (user,group,dacl,sacl)
#    Each part is verified separetly, for dacl and sacl ACL is splited into
#    ACEs and each ACE is verified separately (so that a permutation in ACE
#    didn't raise as an error).
# 20)The oemInfo field is updated to add information about the fact that the
#    provision has been updated by the upgradeprovision version xxx
#    (the version is the one obtained when starting samba with the --version
#    parameter)
# 21)Check if the current provision has all the settings needed for dynamic
#    DNS update to work (that is to say the provision is newer than
#    january 2010). If not dns configuration file from reference provision
#    are copied in a sub folder and the administrator is invited to
#    do what is needed.
# 22)If the lastProvisionUSN attribute was present it is updated to add
#    the range of usns modified by the current upgradeprovision


# About updating the sam DB
# The update takes place in update_partition function
# This function read both current and reference provision and list all
# the available DN of objects
# If the string representation of a DN in reference provision is
# equal to the string representation of a DN in current provision
# (without taking care of case) then the object is flaged as being
# present. If the object is not present in current provision the object
# is being flaged as missing in current provision. Object present in current
# provision but not in reference provision are ignored.
# Once the list of objects present and missing is done, the deleted object
# containers are created in the differents partitions (if missing)
#
# Then the function add_missing_entries is called
# This function will go through the list of missing entries by calling
# add_missing_object for the given object. If this function returns 0
# it means that the object needs some other object in order to be created
# The object is reappended at the end of the list to be created later
# (and preferably after all the needed object have been created)
# The function keeps on looping on the list of object to be created until
# it's empty or that the number of defered creation is equal to the number
# of object that still needs to be created.

# The function add_missing_object will first check if the object can be created.
# That is to say that it didn't depends other not yet created objects
# If requisit can't be fullfilled it exists with 0
# Then it will try to create the missing entry by creating doing
# an ldb_message_diff between the object in the reference provision and
# an empty object.
# This resulting object is filtered to remove all the back link attribute
# (ie. memberOf) as they will be created by the other linked object (ie.
# the one with the member attribute)
# All attributes specified in the hashAttrNotCopied associative array are
# also removed it's most of the time generated attributes

# After missing entries have been added the update_partition function will
# take care of object that exist but that need some update.
# In order to do so the function update_present is called with the list
# of object that are present in both provision and that might need an update.

# This function handle first case mismatch so that the DN in the current
# provision have the same case as in reference provision

# It will then construct an associative array consiting of attributes as
# key and invocationid as value( if the originating invocation id is
# different from the invocation id of the current DC the value is -1 instead).

# If the range of provision modified attributes is present, the function will
# use the replMetadataProperty update method which is the following:
#  Removing attributes that should not be updated: rIDAvailablePool, objectSid,
#   creationTime, msDs-KeyVersionNumber, oEMInformation
#  Check for each attribute if its usn is within one of the modified by
#   provision range and if its originating id is the invocation id of the
#   current DC, then validate the update from reference to current.
#   If not or if there is no replMetatdataProperty for this attribute then we
#   do not update it.
# Otherwise (case the range of provision modified attribute is not present) it
# use the following process:
#  All attributes that need to be added are accepted at the exeption of those
#   listed in hashOverwrittenAtt, in this case the attribute needs to have the
#   correct flags specified.
#  For attributes that need to be modified or removed, a check is performed
#  in OverwrittenAtt, if the attribute is present and the modification flag
#  (remove, delete) is one of those listed for this attribute then modification
#  is accepted. For complicated handling of attribute update, the control is passed
#  to handle_special_case



if __name__ == '__main__':
    global defSDmodified
    defSDmodified = 0
    # From here start the big steps of the program
    # 1) First get files paths
    paths = get_paths(param, smbconf=smbconf)
    paths.setup = setup_dir
    # Get ldbs with the system session, it is needed for searching
    # provision parameters
    session = system_session()

    # This variable will hold the last provision USN once if it exists.
    minUSN = 0
    # 2)
    ldbs = get_ldbs(paths, creds, session, lp)
    ldbs.startTransactions()

    # 3) Guess all the needed names (variables in fact) from the current
    # provision.
    names = find_provision_key_parameters(ldbs.sam, ldbs.secrets, paths,
                                            smbconf, lp)
    # 4)
    lastProvisionUSNs = getLastProvisionUSN(ldbs.sam)
    if lastProvisionUSNs != None:
        message(CHANGE,
            "Find a last provision USN, %d range(s)" % len(lastProvisionUSNs))

    # Objects will be created with the admin session
    # (not anymore system session)
    adm_session = admin_session(lp, str(names.domainsid))
    # So we reget handle on objects
    # ldbs = get_ldbs(paths, creds, adm_session, lp)

    if not sanitychecks(ldbs.sam, names):
        message(SIMPLE, "Sanity checks for the upgrade fails, checks messages" \
                        " and correct them before rerunning upgradeprovision")
        sys.exit(1)

    # Let's see provision parameters
    print_provision_key_parameters(names)

    # 5) With all this information let's create a fresh new provision used as
    # reference
    message(SIMPLE, "Creating a reference provision")
    provisiondir = tempfile.mkdtemp(dir=paths.private_dir,
                                    prefix="referenceprovision")
    newprovision(names, setup_dir, creds, session, smbconf, provisiondir,
                    provision_logger)

    # TODO
    # 6) and 7)
    # We need to get a list of object which SD is directly computed from
    # defaultSecurityDescriptor.
    # This will allow us to know which object we can rebuild the SD in case
    # of change of the parent's SD or of the defaultSD.
    # Get file paths of this new provision
    newpaths = get_paths(param, targetdir=provisiondir)
    new_ldbs = get_ldbs(newpaths, creds, session, lp)
    new_ldbs.startTransactions()

    # 8) Populate some associative array to ease the update process
    # List of attribute which are link and backlink
    populate_links(new_ldbs.sam, names.schemadn)
    # List of attribute with ASN DN synthax)
    populate_dnsyntax(new_ldbs.sam, names.schemadn)
    # 9)
    update_privilege(newpaths.private_dir, paths.private_dir)
    # 10)
    oem = getOEMInfo(ldbs.sam, names.rootdn)
    # Do some modification on sam.ldb
    ldbs.groupedCommit()
    # 11)
    if re.match(".*alpha((9)|(\d\d+)).*", str(oem)):
        # 11) A
        # Starting from alpha9 we can consider that the structure is quite ok
        # and that we should do only dela
        new_ldbs.groupedCommit()
        delta_update_basesamdb(newpaths, paths, creds, session, lp)
        ldbs.startTransactions()
        minUSN = get_max_usn(ldbs.sam, str(names.rootdn)) + 1
        new_ldbs.startTransactions()
    else:
        # 11) B
        simple_update_basesamdb(newpaths, paths, names)
        ldbs = get_ldbs(paths, creds, session, lp)
        ldbs.startTransactions()
        removeProvisionUSN(ldbs.sam)

    # 12)
    schema = Schema(setup_path, names.domainsid, schemadn=str(names.schemadn),
                    serverdn=str(names.serverdn))
    # 13)
    if opts.full:
        if not update_samdb(new_ldbs.sam, ldbs.sam, names, lastProvisionUSNs,
                            schema):
            message(SIMPLE, "Rollbacking every changes. Check the reason" \
                            " of the problem")
            message(SIMPLE, "In any case your system as it was before" \
                            " the upgrade")
            ldbs.groupedRollback()
            new_ldbs.groupedRollback()
            shutil.rmtree(provisiondir)
            sys.exit(1)
    # 14)
    update_secrets(new_ldbs.secrets, ldbs.secrets)
    # 15)
    update_machine_account_password(ldbs.sam, ldbs.secrets, names)

    # 16) SD should be created with admin but as some previous acl were so wrong
    # that admin can't modify them we have first to recreate them with the good
    # form but with system account and then give the ownership to admin ...
    if not re.match(r'.*alpha(9|\d\d+)', str(oem)):
        message(SIMPLE, "Fixing old povision SD")
        fix_partition_sd(ldbs.sam, names)
        rebuild_sd(ldbs.sam, names)

    # We calculate the max USN before recalculating the SD because we might
    # touch object that have been modified after a provision and we do not
    # want that the next upgradeprovision thinks that it has a green light
    # to modify them

    # 17)
    maxUSN = get_max_usn(ldbs.sam, str(names.rootdn))

    # 18) We rebuild SD only if defaultSecurityDescriptor is modified
    # But in fact we should do it also if one object has its SD modified as
    # child might need rebuild
    if defSDmodified == 1:
        message(SIMPLE, "Updating SD")
        ldbs.sam.set_session_info(adm_session)
        # Alpha10 was a bit broken still
        if re.match(r'.*alpha(\d|10)', str(oem)):
            fix_partition_sd(ldbs.sam, names)
        rebuild_sd(ldbs.sam, names)

    # 19)
    # Now we are quite confident in the recalculate process of the SD, we make
    # it optional.
    # Also the check must be done in a clever way as for the moment we just
    # compare SDDL
    if opts.debugchangesd:
        check_updated_sd(new_ldbs.sam, ldbs.sam, names)

    # 20)
    updateOEMInfo(ldbs.sam, names)
    # 21)
    check_for_DNS(newpaths.private_dir, paths.private_dir)
    # 22)
    if lastProvisionUSNs != None:
        updateProvisionUSN(ldbs.sam, minUSN, maxUSN)
    ldbs.groupedCommit()
    new_ldbs.groupedCommit()
    message(SIMPLE, "Upgrade finished !")
    # remove reference provision now that everything is done !
    shutil.rmtree(provisiondir)