# domain_backup # # Copyright Andrew Bartlett # # 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 . # import datetime import os import sys import tarfile import logging import shutil import tempfile import samba import samba.getopt as options from samba.samdb import SamDB import ldb from samba import smb from samba.ntacls import backup_online, backup_restore from samba.auth import system_session from samba.join import DCJoinContext, join_clone, DCCloneAndRenameContext from samba.dcerpc.security import dom_sid from samba.netcmd import Option, CommandError from samba.dcerpc import misc from samba import Ldb from fsmo import cmd_fsmo_seize from samba.provision import make_smbconf from samba.upgradehelpers import update_krbtgt_account_password from samba.remove_dc import remove_dc from samba.provision import secretsdb_self_join from samba.dbchecker import dbcheck import re # work out a SID (based on a free RID) to use when the domain gets restored. # This ensures that the restored DC's SID won't clash with any other RIDs # already in use in the domain def get_sid_for_restore(samdb): # Find the DN of the RID set of the server res = samdb.search(base=ldb.Dn(samdb, samdb.get_serverName()), scope=ldb.SCOPE_BASE, attrs=["serverReference"]) server_ref_dn = ldb.Dn(samdb, res[0]['serverReference'][0]) res = samdb.search(base=server_ref_dn, scope=ldb.SCOPE_BASE, attrs=['rIDSetReferences']) rid_set_dn = ldb.Dn(samdb, res[0]['rIDSetReferences'][0]) # Get the alloc pools and next RID of the RID set res = samdb.search(base=rid_set_dn, scope=ldb.SCOPE_SUBTREE, expression="(rIDNextRID=*)", attrs=['rIDAllocationPool', 'rIDPreviousAllocationPool', 'rIDNextRID']) # Decode the bounds of the RID allocation pools rid = int(res[0].get('rIDNextRID')[0]) def split_val(num): high = (0xFFFFFFFF00000000 & int(num)) >> 32 low = 0x00000000FFFFFFFF & int(num) return low, high pool_l, pool_h = split_val(res[0].get('rIDPreviousAllocationPool')[0]) npool_l, npool_h = split_val(res[0].get('rIDAllocationPool')[0]) # Calculate next RID based on pool bounds if rid == npool_h: raise CommandError('Out of RIDs, finished AllocPool') if rid == pool_h: if pool_h == npool_h: raise CommandError('Out of RIDs, finished PrevAllocPool.') rid = npool_l else: rid += 1 # Construct full SID sid = dom_sid(samdb.get_domain_sid()) return str(sid) + '-' + str(rid) def get_timestamp(): return datetime.datetime.now().isoformat().replace(':', '-') def backup_filepath(targetdir, name, time_str): filename = 'samba-backup-{}-{}.tar.bz2'.format(name, time_str) return os.path.join(targetdir, filename) def create_backup_tar(logger, tmpdir, backup_filepath): # Adds everything in the tmpdir into a new tar file logger.info("Creating backup file %s..." % backup_filepath) tf = tarfile.open(backup_filepath, 'w:bz2') tf.add(tmpdir, arcname='./') tf.close() # Add a backup-specific marker to the DB with info that we'll use during # the restore process def add_backup_marker(samdb, marker, value): m = ldb.Message() m.dn = ldb.Dn(samdb, "@SAMBA_DSDB") m[marker] = ldb.MessageElement(value, ldb.FLAG_MOD_ADD, marker) samdb.modify(m) def check_online_backup_args(logger, credopts, server, targetdir): # Make sure we have all the required args. u_p = {'user': credopts.creds.get_username(), 'pass': credopts.creds.get_password()} if None in u_p.values(): raise CommandError("Creds required.") if server is None: raise CommandError('Server required') if targetdir is None: raise CommandError('Target directory required') if not os.path.exists(targetdir): logger.info('Creating targetdir %s...' % targetdir) os.makedirs(targetdir) class cmd_domain_backup_online(samba.netcmd.Command): '''Copy a running DC's current DB into a backup tar file. Takes a backup copy of the current domain from a running DC. If the domain were to undergo a catastrophic failure, then the backup file can be used to recover the domain. The backup created is similar to the DB that a new DC would receive when it joins the domain. Note that: - it's recommended to run 'samba-tool dbcheck' before taking a backup-file and fix any errors it reports. - all the domain's secrets are included in the backup file. - although the DB contents can be untarred and examined manually, you need to run 'samba-tool domain backup restore' before you can start a Samba DC from the backup file.''' synopsis = "%prog --server= --targetdir=" takes_optiongroups = { "sambaopts": options.SambaOptions, "credopts": options.CredentialsOptions, } takes_options = [ Option("--server", help="The DC to backup", type=str), Option("--targetdir", type=str, help="Directory to write the backup file to"), ] def run(self, sambaopts=None, credopts=None, server=None, targetdir=None): logger = self.get_logger() logger.setLevel(logging.DEBUG) # Make sure we have all the required args. check_online_backup_args(logger, credopts, server, targetdir) lp = sambaopts.get_loadparm() creds = credopts.get_credentials(lp) if not os.path.exists(targetdir): logger.info('Creating targetdir %s...' % targetdir) os.makedirs(targetdir) tmpdir = tempfile.mkdtemp(dir=targetdir) # Run a clone join on the remote ctx = join_clone(logger=logger, creds=creds, lp=lp, include_secrets=True, dns_backend='SAMBA_INTERNAL', server=server, targetdir=tmpdir) # get the paths used for the clone, then drop the old samdb connection paths = ctx.paths del ctx # Get a free RID to use as the new DC's SID (when it gets restored) remote_sam = SamDB(url='ldap://' + server, credentials=creds, session_info=system_session(), lp=lp) new_sid = get_sid_for_restore(remote_sam) realm = remote_sam.domain_dns_name() # Grab the remote DC's sysvol files and bundle them into a tar file sysvol_tar = os.path.join(tmpdir, 'sysvol.tar.gz') smb_conn = smb.SMB(server, "sysvol", lp=lp, creds=creds) backup_online(smb_conn, sysvol_tar, remote_sam.get_domain_sid()) # remove the default sysvol files created by the clone (we want to # make sure we restore the sysvol.tar.gz files instead) shutil.rmtree(paths.sysvol) # Edit the downloaded sam.ldb to mark it as a backup samdb = SamDB(url=paths.samdb, session_info=system_session(), lp=lp) time_str = get_timestamp() add_backup_marker(samdb, "backupDate", time_str) add_backup_marker(samdb, "sidForRestore", new_sid) # Add everything in the tmpdir to the backup tar file backup_file = backup_filepath(targetdir, realm, time_str) create_backup_tar(logger, tmpdir, backup_file) shutil.rmtree(tmpdir) class cmd_domain_backup_restore(cmd_fsmo_seize): '''Restore the domain's DB from a backup-file. This restores a previously backed up copy of the domain's DB on a new DC. Note that the restored DB will not contain the original DC that the backup was taken from (or any other DCs in the original domain). Only the new DC (specified by --newservername) will be present in the restored DB. Samba can then be started against the restored DB. Any existing DCs for the domain should be shutdown before the new DC is started. Other DCs can then be joined to the new DC to recover the network. Note that this command should be run as the root user - it will fail otherwise.''' synopsis = ("%prog --backup-file= --targetdir= " "--newservername=") takes_options = [ Option("--backup-file", help="Path to backup file", type=str), Option("--targetdir", help="Path to write to", type=str), Option("--newservername", help="Name for new server", type=str), ] takes_optiongroups = { "sambaopts": options.SambaOptions, "credopts": options.CredentialsOptions, } def run(self, sambaopts=None, credopts=None, backup_file=None, targetdir=None, newservername=None): if not (backup_file and os.path.exists(backup_file)): raise CommandError('Backup file not found.') if targetdir is None: raise CommandError('Please specify a target directory') # allow restoredc to install into a directory prepopulated by selftest if (os.path.exists(targetdir) and os.listdir(targetdir) and os.environ.get('SAMBA_SELFTEST') != '1'): raise CommandError('Target directory is not empty') if not newservername: raise CommandError('Server name required') logger = logging.getLogger() logger.setLevel(logging.DEBUG) logger.addHandler(logging.StreamHandler(sys.stdout)) # ldapcmp prefers the server's netBIOS name in upper-case newservername = newservername.upper() # extract the backup .tar to a temp directory targetdir = os.path.abspath(targetdir) tf = tarfile.open(backup_file) tf.extractall(targetdir) tf.close() # use the smb.conf that got backed up, by default (save what was # actually backed up, before we mess with it) smbconf = os.path.join(targetdir, 'etc', 'smb.conf') shutil.copyfile(smbconf, smbconf + ".orig") # if a smb.conf was specified on the cmd line, then use that instead cli_smbconf = sambaopts.get_loadparm_path() if cli_smbconf: logger.info("Using %s as restored domain's smb.conf" % cli_smbconf) shutil.copyfile(cli_smbconf, smbconf) lp = samba.param.LoadParm() lp.load(smbconf) # open a DB connection to the restored DB private_dir = os.path.join(targetdir, 'private') samdb_path = os.path.join(private_dir, 'sam.ldb') samdb = SamDB(url=samdb_path, session_info=system_session(), lp=lp) # Create account using the join_add_objects function in the join object # We need namingContexts, account control flags, and the sid saved by # the backup process. res = samdb.search(base="", scope=ldb.SCOPE_BASE, attrs=['namingContexts']) ncs = [str(r) for r in res[0].get('namingContexts')] creds = credopts.get_credentials(lp) ctx = DCJoinContext(logger, creds=creds, lp=lp, forced_local_samdb=samdb, netbios_name=newservername) ctx.nc_list = ncs ctx.full_nc_list = ncs ctx.userAccountControl = (samba.dsdb.UF_SERVER_TRUST_ACCOUNT | samba.dsdb.UF_TRUSTED_FOR_DELEGATION) # rewrite the smb.conf to make sure it uses the new targetdir settings. # (This doesn't update all filepaths in a customized config, but it # corrects the same paths that get set by a new provision) logger.info('Updating basic smb.conf settings...') make_smbconf(smbconf, newservername, ctx.domain_name, ctx.realm, targetdir, lp=lp, serverrole="active directory domain controller") # Get the SID saved by the backup process and create account res = samdb.search(base=ldb.Dn(samdb, "@SAMBA_DSDB"), scope=ldb.SCOPE_BASE, attrs=['sidForRestore']) sid = res[0].get('sidForRestore')[0] logger.info('Creating account with SID: ' + str(sid)) ctx.join_add_objects(specified_sid=dom_sid(sid)) m = ldb.Message() m.dn = ldb.Dn(samdb, '@ROOTDSE') ntds_guid = str(ctx.ntds_guid) m["dsServiceName"] = ldb.MessageElement("" % ntds_guid, ldb.FLAG_MOD_REPLACE, "dsServiceName") samdb.modify(m) secrets_path = os.path.join(private_dir, 'secrets.ldb') secrets_ldb = Ldb(secrets_path, session_info=system_session(), lp=lp) secretsdb_self_join(secrets_ldb, domain=ctx.domain_name, realm=ctx.realm, dnsdomain=ctx.dnsdomain, netbiosname=ctx.myname, domainsid=ctx.domsid, machinepass=ctx.acct_pass, key_version_number=ctx.key_version_number, secure_channel_type=misc.SEC_CHAN_BDC) # Seize DNS roles domain_dn = samdb.domain_dn() forest_dn = samba.dn_from_dns_name(samdb.forest_dns_name()) domaindns_dn = ("CN=Infrastructure,DC=DomainDnsZones,", domain_dn) forestdns_dn = ("CN=Infrastructure,DC=ForestDnsZones,", forest_dn) for dn_prefix, dns_dn in [forestdns_dn, domaindns_dn]: if dns_dn not in ncs: continue full_dn = dn_prefix + dns_dn m = ldb.Message() m.dn = ldb.Dn(samdb, full_dn) m["fSMORoleOwner"] = ldb.MessageElement(samdb.get_dsServiceName(), ldb.FLAG_MOD_REPLACE, "fSMORoleOwner") samdb.modify(m) # Seize other roles for role in ['rid', 'pdc', 'naming', 'infrastructure', 'schema']: self.seize_role(role, samdb, force=True) # Get all DCs and remove them (this ensures these DCs cannot # replicate because they will not have a password) search_expr = "(&(objectClass=Server)(serverReference=*))" res = samdb.search(samdb.get_config_basedn(), scope=ldb.SCOPE_SUBTREE, expression=search_expr) for m in res: cn = m.get('cn')[0] if cn != newservername: remove_dc(samdb, logger, cn) # Remove the repsFrom and repsTo from each NC to ensure we do # not try (and fail) to talk to the old DCs for nc in ncs: msg = ldb.Message() msg.dn = ldb.Dn(samdb, nc) msg["repsFrom"] = ldb.MessageElement([], ldb.FLAG_MOD_REPLACE, "repsFrom") msg["repsTo"] = ldb.MessageElement([], ldb.FLAG_MOD_REPLACE, "repsTo") samdb.modify(msg) # Update the krbtgt passwords twice, ensuring no tickets from # the old domain are valid update_krbtgt_account_password(samdb) update_krbtgt_account_password(samdb) # restore the sysvol directory from the backup tar file, including the # original NTACLs. Note that the backup_restore() will fail if not root sysvol_tar = os.path.join(targetdir, 'sysvol.tar.gz') dest_sysvol_dir = lp.get('path', 'sysvol') if not os.path.exists(dest_sysvol_dir): os.makedirs(dest_sysvol_dir) backup_restore(sysvol_tar, dest_sysvol_dir, samdb, smbconf) os.remove(sysvol_tar) # Remove DB markers added by the backup process m = ldb.Message() m.dn = ldb.Dn(samdb, "@SAMBA_DSDB") m["backupDate"] = ldb.MessageElement([], ldb.FLAG_MOD_DELETE, "backupDate") m["sidForRestore"] = ldb.MessageElement([], ldb.FLAG_MOD_DELETE, "sidForRestore") samdb.modify(m) logger.info("Backup file successfully restored to %s" % targetdir) logger.info("Please check the smb.conf settings are correct before " "starting samba.") class cmd_domain_backup_rename(samba.netcmd.Command): '''Copy a running DC's DB to backup file, renaming the domain in the process. Where is the new domain's NetBIOS name, and is the new domain's realm in DNS form. This is similar to 'samba-tool backup online' in that it clones the DB of a running DC. However, this option also renames all the domain entries in the DB. Renaming the domain makes it possible to restore and start a new Samba DC without it interfering with the existing Samba domain. In other words, you could use this option to clone your production samba domain and restore it to a separate pre-production environment that won't overlap or interfere with the existing production Samba domain. Note that: - it's recommended to run 'samba-tool dbcheck' before taking a backup-file and fix any errors it reports. - all the domain's secrets are included in the backup file. - although the DB contents can be untarred and examined manually, you need to run 'samba-tool domain backup restore' before you can start a Samba DC from the backup file. - GPO and sysvol information will still refer to the old realm and will need to be updated manually. - if you specify 'keep-dns-realm', then the DNS records will need updating in order to work (they will still refer to the old DC's IP instead of the new DC's address). - we recommend that you only use this option if you know what you're doing. ''' synopsis = ("%prog --server= " "--targetdir=") takes_optiongroups = { "sambaopts": options.SambaOptions, "credopts": options.CredentialsOptions, } takes_options = [ Option("--server", help="The DC to backup", type=str), Option("--targetdir", help="Directory to write the backup file", type=str), Option("--keep-dns-realm", action="store_true", default=False, help="Retain the DNS entries for the old realm in the backup"), ] takes_args = ["new_domain_name", "new_dns_realm"] def update_dns_root(self, logger, samdb, old_realm, delete_old_dns): '''Updates dnsRoot for the partition objects to reflect the rename''' # lookup the crossRef objects that hold the old realm's dnsRoot partitions_dn = samdb.get_partitions_dn() res = samdb.search(base=partitions_dn, scope=ldb.SCOPE_ONELEVEL, attrs=["dnsRoot"], expression='(&(objectClass=crossRef)(dnsRoot=*))') new_realm = samdb.domain_dns_name() # go through and add the new realm for res_msg in res: # dnsRoot can be multi-valued, so only look for the old realm for dns_root in res_msg["dnsRoot"]: dn = res_msg.dn if old_realm in dns_root: new_dns_root = re.sub('%s$' % old_realm, new_realm, dns_root) logger.info("Adding %s dnsRoot to %s" % (new_dns_root, dn)) m = ldb.Message() m.dn = dn m["dnsRoot"] = ldb.MessageElement(new_dns_root, ldb.FLAG_MOD_ADD, "dnsRoot") samdb.modify(m) # optionally remove the dnsRoot for the old realm if delete_old_dns: logger.info("Removing %s dnsRoot from %s" % (dns_root, dn)) m["dnsRoot"] = ldb.MessageElement(dns_root, ldb.FLAG_MOD_DELETE, "dnsRoot") samdb.modify(m) # Updates the CN=,CN=Partitions,CN=Configuration,... object to # reflect the domain rename def rename_domain_partition(self, logger, samdb, new_netbios_name): '''Renames the domain parition object and updates its nETBIOSName''' # lookup the crossRef object that holds the nETBIOSName (nCName has # already been updated by this point, but the netBIOS hasn't) base_dn = samdb.get_default_basedn() nc_name = ldb.binary_encode(str(base_dn)) partitions_dn = samdb.get_partitions_dn() res = samdb.search(base=partitions_dn, scope=ldb.SCOPE_ONELEVEL, attrs=["nETBIOSName"], expression='ncName=%s' % nc_name) logger.info("Changing backup domain's NetBIOS name to %s" % new_netbios_name) m = ldb.Message() m.dn = res[0].dn m["nETBIOSName"] = ldb.MessageElement(new_netbios_name, ldb.FLAG_MOD_REPLACE, "nETBIOSName") samdb.modify(m) # renames the object itself to reflect the change in domain new_dn = "CN=%s,%s" % (new_netbios_name, partitions_dn) logger.info("Renaming %s --> %s" % (res[0].dn, new_dn)) samdb.rename(res[0].dn, new_dn, controls=['relax:0']) def delete_old_dns_zones(self, logger, samdb, old_realm): # remove the top-level DNS entries for the old realm basedn = samdb.get_default_basedn() dn = "DC=%s,CN=MicrosoftDNS,DC=DomainDnsZones,%s" % (old_realm, basedn) logger.info("Deleting old DNS zone %s" % dn) samdb.delete(dn, ["tree_delete:1"]) forestdn = samdb.get_root_basedn().get_linearized() dn = "DC=_msdcs.%s,CN=MicrosoftDNS,DC=ForestDnsZones,%s" % (old_realm, forestdn) logger.info("Deleting old DNS zone %s" % dn) samdb.delete(dn, ["tree_delete:1"]) def fix_old_dn_attributes(self, samdb): '''Fixes attributes (i.e. objectCategory) that still use the old DN''' samdb.transaction_start() # Just fix any mismatches in DN detected (leave any other errors) chk = dbcheck(samdb, quiet=True, fix=True, yes=False, in_transaction=True) # fix up incorrect objectCategory/etc attributes setattr(chk, 'fix_all_old_dn_string_component_mismatch', 'ALL') cross_ncs_ctrl = 'search_options:1:2' controls = ['show_deleted:1', cross_ncs_ctrl] chk.check_database(controls=controls) samdb.transaction_commit() def run(self, new_domain_name, new_dns_realm, sambaopts=None, credopts=None, server=None, targetdir=None, keep_dns_realm=False): logger = self.get_logger() logger.setLevel(logging.INFO) # Make sure we have all the required args. check_online_backup_args(logger, credopts, server, targetdir) delete_old_dns = not keep_dns_realm new_dns_realm = new_dns_realm.lower() new_domain_name = new_domain_name.upper() new_base_dn = samba.dn_from_dns_name(new_dns_realm) logger.info("New realm for backed up domain: %s" % new_dns_realm) logger.info("New base DN for backed up domain: %s" % new_base_dn) logger.info("New domain NetBIOS name: %s" % new_domain_name) tmpdir = tempfile.mkdtemp(dir=targetdir) # Clone and rename the remote server lp = sambaopts.get_loadparm() creds = credopts.get_credentials(lp) ctx = DCCloneAndRenameContext(new_base_dn, new_domain_name, new_dns_realm, logger=logger, creds=creds, lp=lp, include_secrets=True, dns_backend='SAMBA_INTERNAL', server=server, targetdir=tmpdir) ctx.do_join() # get the paths used for the clone, then drop the old samdb connection del ctx.local_samdb paths = ctx.paths # get a free RID to use as the new DC's SID (when it gets restored) remote_sam = SamDB(url='ldap://' + server, credentials=creds, session_info=system_session(), lp=lp) new_sid = get_sid_for_restore(remote_sam) old_realm = remote_sam.domain_dns_name() # Grab the remote DC's sysvol files and bundle them into a tar file. # Note we end up with 2 sysvol dirs - the original domain's files (that # use the old realm) backed here, as well as default files generated # for the new realm as part of the clone/join. sysvol_tar = os.path.join(tmpdir, 'sysvol.tar.gz') smb_conn = smb.SMB(server, "sysvol", lp=lp, creds=creds) backup_online(smb_conn, sysvol_tar, remote_sam.get_domain_sid()) # connect to the local DB (making sure we use the new/renamed config) lp.load(paths.smbconf) samdb = SamDB(url=paths.samdb, session_info=system_session(), lp=lp) # Edit the cloned sam.ldb to mark it as a backup time_str = get_timestamp() add_backup_marker(samdb, "backupDate", time_str) add_backup_marker(samdb, "sidForRestore", new_sid) add_backup_marker(samdb, "backupRename", old_realm) # fix up the DNS objects that are using the old dnsRoot value self.update_dns_root(logger, samdb, old_realm, delete_old_dns) # update the netBIOS name and the Partition object for the domain self.rename_domain_partition(logger, samdb, new_domain_name) if delete_old_dns: self.delete_old_dns_zones(logger, samdb, old_realm) logger.info("Fixing DN attributes after rename...") self.fix_old_dn_attributes(samdb) # Add everything in the tmpdir to the backup tar file backup_file = backup_filepath(targetdir, new_dns_realm, time_str) create_backup_tar(logger, tmpdir, backup_file) shutil.rmtree(tmpdir) class cmd_domain_backup(samba.netcmd.SuperCommand): '''Create or restore a backup of the domain.''' subcommands = {'online': cmd_domain_backup_online(), 'rename': cmd_domain_backup_rename(), 'restore': cmd_domain_backup_restore()}