source4/scripting/bin/samba_upgradedns

   1 #!/usr/bin/env python
   2 #
   3 # Unix SMB/CIFS implementation.
   4 # Copyright (C) Amitay Isaacs <amitay@gmail.com> 2012
   5 #
   6 # Upgrade DNS provision from BIND9_FLATFILE to BIND9_DLZ or SAMBA_INTERNAL
   7 #
   8 # This program is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 3 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 import sys
  22 import os
  23 import optparse
  24 import logging
  25 import grp
  26 from base64 import b64encode
  27 import shlex
  28
  29 sys.path.insert(0, "bin/python")
  30
  31 import ldb
  32 import samba
  33 from samba import param
  34 from samba.auth import system_session
  35 from samba.ndr import (
  36     ndr_pack,
  37     ndr_unpack )
  38 import samba.getopt as options
  39 from samba.upgradehelpers import (
  40     get_paths,
  41     get_ldbs )
  42 from samba.dsdb import DS_DOMAIN_FUNCTION_2003
  43 from samba.provision import (
  44     find_provision_key_parameters,
  45     interface_ips_v4,
  46     interface_ips_v6 )
  47 from samba.provision.common import (
  48     setup_path,
  49     setup_add_ldif,
  50     FILL_FULL)
  51 from samba.provision.sambadns import (
  52     ARecord,
  53     AAAARecord,
  54     CNameRecord,
  55     NSRecord,
  56     SOARecord,
  57     SRVRecord,
  58     TXTRecord,
  59     get_dnsadmins_sid,
  60     add_dns_accounts,
  61     create_dns_partitions,
  62     fill_dns_data_partitions,
  63     create_dns_dir,
  64     secretsdb_setup_dns,
  65     create_samdb_copy,
  66     create_named_conf,
  67     create_named_txt )
  68 from samba.dcerpc import security
  69
  70 samba.ensure_external_module("dns", "dnspython")
  71 import dns.zone, dns.rdatatype
  72
  73 __docformat__ = 'restructuredText'
  74
  75
  76 def find_bind_gid():
  77     """Find system group id for bind9
  78     """
  79     for name in ["bind", "named"]:
  80         try:
  81             return grp.getgrnam(name)[2]
  82         except KeyError:
  83             pass
  84     return None
  85
  86
  87 def convert_dns_rdata(rdata, serial=1):
  88     """Convert resource records in dnsRecord format
  89     """
  90     if rdata.rdtype == dns.rdatatype.A:
  91         rec = ARecord(rdata.address, serial=serial)
  92     elif rdata.rdtype == dns.rdatatype.AAAA:
  93         rec = AAAARecord(rdata.address, serial=serial)
  94     elif rdata.rdtype == dns.rdatatype.CNAME:
  95         rec = CNameRecord(rdata.target.to_text(), serial=serial)
  96     elif rdata.rdtype == dns.rdatatype.NS:
  97         rec = NSRecord(rdata.target.to_text(), serial=serial)
  98     elif rdata.rdtype == dns.rdatatype.SRV:
  99         rec = SRVRecord(rdata.target.to_text(), int(rdata.port),
 100                         priority=int(rdata.priority), weight=int(rdata.weight),
 101                         serial=serial)
 102     elif rdata.rdtype == dns.rdatatype.TXT:
 103         slist = shlex.split(rdata.to_text())
 104         rec = TXTRecord(slist, serial=serial)
 105     elif rdata.rdtype == dns.rdatatype.SOA:
 106         rec = SOARecord(rdata.mname.to_text(), rdata.rname.to_text(),
 107                         serial=int(rdata.serial),
 108                         refresh=int(rdata.refresh), retry=int(rdata.retry),
 109                         expire=int(rdata.expire), minimum=int(rdata.minimum))
 110     else:
 111         rec = None
 112     return rec
 113
 114
 115 def import_zone_data(samdb, logger, zone, serial, domaindn, forestdn,
 116                      dnsdomain, dnsforest):
 117     """Insert zone data in DNS partitions
 118     """
 119     labels = dnsdomain.split('.')
 120     labels.append('')
 121     domain_root = dns.name.Name(labels)
 122     domain_prefix = "DC=%s,CN=MicrosoftDNS,DC=DomainDnsZones,%s" % (dnsdomain,
 123                                                                     domaindn)
 124
 125     tmp = "_msdcs.%s" % dnsforest
 126     labels = tmp.split('.')
 127     labels.append('')
 128     forest_root = dns.name.Name(labels)
 129     dnsmsdcs = "_msdcs.%s" % dnsforest
 130     forest_prefix = "DC=%s,CN=MicrosoftDNS,DC=ForestDnsZones,%s" % (dnsmsdcs,
 131                                                                     forestdn)
 132
 133     # Extract @ record
 134     at_record = zone.get_node(domain_root)
 135     zone.delete_node(domain_root)
 136
 137     # SOA record
 138     rdset = at_record.get_rdataset(dns.rdataclass.IN, dns.rdatatype.SOA)
 139     soa_rec = ndr_pack(convert_dns_rdata(rdset[0]))
 140     at_record.delete_rdataset(dns.rdataclass.IN, dns.rdatatype.SOA)
 141
 142     # NS record
 143     rdset = at_record.get_rdataset(dns.rdataclass.IN, dns.rdatatype.NS)
 144     ns_rec = ndr_pack(convert_dns_rdata(rdset[0]))
 145     at_record.delete_rdataset(dns.rdataclass.IN, dns.rdatatype.NS)
 146
 147     # A/AAAA records
 148     ip_recs = []
 149     for rdset in at_record:
 150         for r in rdset:
 151             rec = convert_dns_rdata(r)
 152             ip_recs.append(ndr_pack(rec))
 153
 154     # Add @ record for domain
 155     dns_rec = [soa_rec, ns_rec] + ip_recs
 156     msg = ldb.Message(ldb.Dn(samdb, 'DC=@,%s' % domain_prefix))
 157     msg["objectClass"] = ["top", "dnsNode"]
 158     msg["dnsRecord"] = ldb.MessageElement(dns_rec, ldb.FLAG_MOD_ADD,
 159                                           "dnsRecord")
 160     try:
 161         samdb.add(msg)
 162     except Exception:
 163         logger.error("Failed to add @ record for domain")
 164         raise
 165     logger.debug("Added @ record for domain")
 166
 167     # Add @ record for forest
 168     dns_rec = [soa_rec, ns_rec]
 169     msg = ldb.Message(ldb.Dn(samdb, 'DC=@,%s' % forest_prefix))
 170     msg["objectClass"] = ["top", "dnsNode"]
 171     msg["dnsRecord"] = ldb.MessageElement(dns_rec, ldb.FLAG_MOD_ADD,
 172                                           "dnsRecord")
 173     try:
 174         samdb.add(msg)
 175     except Exception:
 176         logger.error("Failed to add @ record for forest")
 177         raise
 178     logger.debug("Added @ record for forest")
 179
 180     # Add remaining records in domain and forest
 181     for node in zone.nodes:
 182         name = node.relativize(forest_root).to_text()
 183         if name == node.to_text():
 184             name = node.relativize(domain_root).to_text()
 185             dn = "DC=%s,%s" % (name, domain_prefix)
 186             fqdn = "%s.%s" % (name, dnsdomain)
 187         else:
 188             dn = "DC=%s,%s" % (name, forest_prefix)
 189             fqdn = "%s.%s" % (name, dnsmsdcs)
 190
 191         dns_rec = []
 192         for rdataset in zone.nodes[node]:
 193             for rdata in rdataset:
 194                 rec = convert_dns_rdata(rdata, serial)
 195                 if not rec:
 196                     logger.warn("Unsupported record type (%s) for %s, ignoring" %
 197                                 dns.rdatatype.to_text(rdata.rdatatype), name)
 198                 else:
 199                     dns_rec.append(ndr_pack(rec))
 200
 201         msg = ldb.Message(ldb.Dn(samdb, dn))
 202         msg["objectClass"] = ["top", "dnsNode"]
 203         msg["dnsRecord"] = ldb.MessageElement(dns_rec, ldb.FLAG_MOD_ADD,
 204                                               "dnsRecord")
 205         try:
 206             samdb.add(msg)
 207         except Exception:
 208             logger.error("Failed to add DNS record %s" % (fqdn))
 209             raise
 210         logger.debug("Added DNS record %s" % (fqdn))
 211
 212
 213 # dnsprovision creates application partitions for AD based DNS mainly if the existing
 214 # provision was created using earlier snapshots of samba4 which did not have support
 215 # for DNS partitions
 216
 217 if __name__ == '__main__':
 218
 219     # Setup command line parser
 220     parser = optparse.OptionParser("upgradedns [options]")
 221     sambaopts = options.SambaOptions(parser)
 222     credopts = options.CredentialsOptions(parser)
 223
 224     parser.add_option_group(options.VersionOptions(parser))
 225     parser.add_option_group(sambaopts)
 226     parser.add_option_group(credopts)
 227
 228     parser.add_option("--dns-backend", type="choice", metavar="<BIND9_DLZ|SAMBA_INTERNAL>",
 229                       choices=["SAMBA_INTERNAL", "BIND9_DLZ"], default="SAMBA_INTERNAL",
 230                       help="The DNS server backend, default SAMBA_INTERNAL")
 231     parser.add_option("--migrate", type="choice", metavar="<yes|no>",
 232                       choices=["yes","no"], default="yes",
 233                       help="Migrate existing zone data, default yes")
 234     parser.add_option("--verbose", help="Be verbose", action="store_true")
 235
 236     opts = parser.parse_args()[0]
 237
 238     if opts.dns_backend is None:
 239         opts.dns_backend = 'SAMBA_INTERNAL'
 240
 241     if opts.migrate:
 242         autofill = False
 243     else:
 244         autofill = True
 245
 246     # Set up logger
 247     logger = logging.getLogger("upgradedns")
 248     logger.addHandler(logging.StreamHandler(sys.stdout))
 249     logger.setLevel(logging.INFO)
 250     if opts.verbose:
 251         logger.setLevel(logging.DEBUG)
 252
 253     lp = sambaopts.get_loadparm()
 254     lp.load(lp.configfile)
 255     creds = credopts.get_credentials(lp)
 256
 257     logger.info("Reading domain information")
 258     paths = get_paths(param, smbconf=lp.configfile)
 259     paths.bind_gid = find_bind_gid()
 260     ldbs = get_ldbs(paths, creds, system_session(), lp)
 261     names = find_provision_key_parameters(ldbs.sam, ldbs.secrets, ldbs.idmap,
 262                                            paths, lp.configfile, lp)
 263
 264     if names.domainlevel < DS_DOMAIN_FUNCTION_2003:
 265         logger.error("Cannot create AD based DNS for OS level < 2003")
 266         sys.exit(1)
 267
 268     domaindn = names.domaindn
 269     forestdn = names.rootdn
 270
 271     dnsdomain = names.dnsdomain.lower()
 272     dnsforest = dnsdomain
 273
 274     site = names.sitename
 275     hostname = names.hostname
 276     dnsname = '%s.%s' % (hostname, dnsdomain)
 277
 278     domainsid = names.domainsid
 279     domainguid = names.domainguid
 280     ntdsguid = names.ntdsguid
 281
 282     # Check for DNS accounts and create them if required
 283     try:
 284         msg = ldbs.sam.search(base=domaindn, scope=ldb.SCOPE_DEFAULT,
 285                               expression='(sAMAccountName=DnsAdmins)',
 286                               attrs=['objectSid'])
 287         dnsadmins_sid = ndr_unpack(security.dom_sid, msg[0]['objectSid'][0])
 288     except IndexError:
 289         logger.info("Adding DNS accounts")
 290         add_dns_accounts(ldbs.sam, domaindn)
 291         dnsadmins_sid = get_dnsadmins_sid(ldbs.sam, domaindn)
 292     else:
 293         logger.info("DNS accounts already exist")
 294
 295     # Import dns records from zone file
 296     if os.path.exists(paths.dns):
 297         logger.info("Reading records from zone file %s" % paths.dns)
 298         try:
 299             zone = dns.zone.from_file(paths.dns, relativize=False)
 300             rrset = zone.get_rdataset("%s." % dnsdomain, dns.rdatatype.SOA)
 301             serial = int(rrset[0].serial)
 302         except Exception, e:
 303             logger.warn("Error parsing DNS data from '%s' (%s)" % (paths.dns, str(e)))
 304             logger.warn("DNS records will be automatically created")
 305             autofill = True
 306     else:
 307         logger.info("No zone file %s" % paths.dns)
 308         logger.warn("DNS records will be automatically created")
 309         autofill = True
 310
 311     # Create DNS partitions if missing and fill DNS information
 312     try:
 313         expression = '(|(dnsRoot=DomainDnsZones.%s)(dnsRoot=ForestDnsZones.%s))' % \
 314                      (dnsdomain, dnsforest)
 315         msg = ldbs.sam.search(base=names.configdn, scope=ldb.SCOPE_DEFAULT,
 316                               expression=expression, attrs=['nCName'])
 317         ncname = msg[0]['nCName'][0]
 318     except IndexError:
 319         logger.info("Creating DNS partitions")
 320
 321         logger.info("Looking up IPv4 addresses")
 322         hostip = interface_ips_v4(lp)
 323         try:
 324             hostip.remove('127.0.0.1')
 325         except ValueError:
 326             pass
 327         if not hostip:
 328             logger.error("No IPv4 addresses found")
 329             sys.exit(1)
 330         else:
 331             hostip = hostip[0]
 332             logger.debug("IPv4 addresses: %s" % hostip)
 333
 334         logger.info("Looking up IPv6 addresses")
 335         hostip6 = interface_ips_v6(lp)
 336         if not hostip6:
 337             hostip6 = None
 338         else:
 339             hostip6 = hostip6[0]
 340         logger.debug("IPv6 addresses: %s" % hostip6)
 341
 342         create_dns_partitions(ldbs.sam, domainsid, names, domaindn, forestdn,
 343                               dnsadmins_sid, FILL_FULL)
 344
 345         logger.info("Populating DNS partitions")
 346         fill_dns_data_partitions(ldbs.sam, domainsid, site, domaindn, forestdn,
 347                              dnsdomain, dnsforest, hostname, hostip, hostip6,
 348                              domainguid, ntdsguid, dnsadmins_sid,
 349                              autofill=autofill)
 350
 351         if not autofill:
 352             logger.info("Importing records from zone file")
 353             import_zone_data(ldbs.sam, logger, zone, serial, domaindn, forestdn,
 354                              dnsdomain, dnsforest)
 355     else:
 356         logger.info("DNS partitions already exist")
 357
 358     # Mark that we are hosting DNS partitions
 359     try:
 360         dns_nclist = [ 'DC=DomainDnsZones,%s' % domaindn,
 361                        'DC=ForestDnsZones,%s' % forestdn ]
 362
 363         msgs = ldbs.sam.search(base=names.serverdn, scope=ldb.SCOPE_DEFAULT,
 364                                expression='(objectclass=nTDSDSa)',
 365                                attrs=['hasPartialReplicaNCs',
 366                                       'msDS-hasMasterNCs'])
 367         msg = msgs[0]
 368
 369         master_nclist = []
 370         ncs = msg.get("msDS-hasMasterNCs")
 371         if ncs:
 372             for nc in ncs:
 373                 master_nclist.append(nc)
 374
 375         partial_nclist = []
 376         ncs = msg.get("hasPartialReplicaNCs")
 377         if ncs:
 378             for nc in ncs:
 379                 partial_nclist.append(nc)
 380
 381         modified_master = False
 382         modified_partial = False
 383         for nc in dns_nclist:
 384             if nc not in master_nclist:
 385                 master_nclist.append(nc)
 386                 modified_master = True
 387             if nc in partial_nclist:
 388                 partial_nclist.remove(nc)
 389                 modified_partial = True
 390
 391         if modified_master or modified_partial:
 392             logger.debug("Updating msDS-hasMasterNCs and hasPartialReplicaNCs attributes")
 393             m = ldb.Message()
 394             m.dn = msg.dn
 395             if modified_master:
 396                 m["msDS-hasMasterNCs"] = ldb.MessageElement(master_nclist,
 397                                                             ldb.FLAG_MOD_REPLACE,
 398                                                             "msDS-hasMasterNCs")
 399             if modified_partial:
 400                 if partial_nclist:
 401                     m["hasPartialReplicaNCs"] = ldb.MessageElement(partial_nclist,
 402                                                                    ldb.FLAG_MOD_REPLACE,
 403                                                                    "hasPartialReplicaNCs")
 404                 else:
 405                     m["hasPartialReplicaNCs"] = ldb.MessageElement(ncs,
 406                                                                    ldb.FLAG_MOD_DELETE,
 407                                                                    "hasPartialReplicaNCs")
 408             ldbs.sam.modify(m)
 409     except Exception:
 410         raise
 411
 412     # Special stuff for DLZ backend
 413     if opts.dns_backend == "BIND9_DLZ":
 414         # Check if dns-HOSTNAME account exists and create it if required
 415         try:
 416             dn = 'samAccountName=dns-%s,CN=Principals' % hostname
 417             msg = ldbs.secrets.search(expression='(dn=%s)' % dn, attrs=['secret'])
 418             dnssecret = msg[0]['secret'][0]
 419         except IndexError:
 420
 421             logger.info("Adding dns-%s account" % hostname)
 422
 423             try:
 424                 msg = ldbs.sam.search(base=domaindn, scope=ldb.SCOPE_DEFAULT,
 425                                       expression='(sAMAccountName=dns-%s)' % (hostname),
 426                                       attrs=[])
 427                 dn = msg[0].dn
 428                 ldbs.sam.delete(dn)
 429             except IndexError:
 430                 pass
 431
 432             dnspass = samba.generate_random_password(128, 255)
 433             setup_add_ldif(ldbs.sam, setup_path("provision_dns_add_samba.ldif"), {
 434                     "DNSDOMAIN": dnsdomain,
 435                     "DOMAINDN": domaindn,
 436                     "DNSPASS_B64": b64encode(dnspass.encode('utf-16-le')),
 437                     "HOSTNAME" : hostname,
 438                     "DNSNAME" : dnsname }
 439                            )
 440
 441             res = ldbs.sam.search(base=domaindn, scope=ldb.SCOPE_DEFAULT,
 442                                   expression='(sAMAccountName=dns-%s)' % (hostname),
 443                                   attrs=["msDS-KeyVersionNumber"])
 444             if "msDS-KeyVersionNumber" in res[0]:
 445                 dns_key_version_number = int(res[0]["msDS-KeyVersionNumber"][0])
 446             else:
 447                 dns_key_version_number = None
 448
 449             secretsdb_setup_dns(ldbs.secrets, names,
 450                                 paths.private_dir, realm=names.realm,
 451                                 dnsdomain=names.dnsdomain,
 452                                 dns_keytab_path=paths.dns_keytab, dnspass=dnspass,
 453                                 key_version_number=dns_key_version_number)
 454         else:
 455             logger.info("dns-%s account already exists" % hostname)
 456
 457         # This forces a re-creation of dns directory and all the files within
 458         # It's an overkill, but it's easier to re-create a samdb copy, rather
 459         # than trying to fix a broken copy.
 460         create_dns_dir(logger, paths)
 461
 462         # Setup a copy of SAM for BIND9
 463         create_samdb_copy(ldbs.sam, logger, paths, names, domainsid,
 464                           domainguid)
 465
 466         create_named_conf(paths, names.realm, dnsdomain, opts.dns_backend, logger)
 467
 468         create_named_txt(paths.namedtxt, names.realm, dnsdomain, dnsname,
 469                          paths.private_dir, paths.dns_keytab)
 470         logger.info("See %s for an example configuration include file for BIND", paths.namedconf)
 471         logger.info("and %s for further documentation required for secure DNS "
 472                     "updates", paths.namedtxt)
 473     elif opts.dns_backend == "SAMBA_INTERNAL":
 474         # Check if dns-HOSTNAME account exists and delete it if required
 475         try:
 476             dn_str = 'samAccountName=dns-%s,CN=Principals' % hostname
 477             msg = ldbs.secrets.search(expression='(dn=%s)' % dn_str, attrs=[])
 478             dn = msg[0].dn
 479         except IndexError:
 480             dn = None
 481
 482         if dn is not None:
 483             try:
 484                 ldbs.secrets.delete(dn)
 485             except Exception:
 486                 logger.info("Failed to delete %s from secrets.ldb" % dn)
 487
 488         try:
 489             msg = ldbs.sam.search(base=domaindn, scope=ldb.SCOPE_DEFAULT,
 490                                   expression='(sAMAccountName=dns-%s)' % (hostname),
 491                                   attrs=[])
 492             dn = msg[0].dn
 493         except IndexError:
 494             dn = None
 495
 496         if dn is not None:
 497             try:
 498                 ldbs.sam.delete(dn)
 499             except Exception:
 500                 logger.info("Failed to delete %s from sam.ldb" % dn)
 501
 502     logger.info("Finished upgrading DNS")
 503
 504     services = lp.get("server services")
 505     for service in services:
 506         if service == "dns":
 507             if opts.dns_backend.startswith("BIND"):
 508                 logger.info("You have switched to using %s as your dns backend,"
 509                         " but still have the internal dns starting. Please"
 510                         " make sure you add '-dns' to your server services"
 511                         " line in your smb.conf." % opts.dns_backend)
 512             break
 513     else:
 514         if opts.dns_backend == "SAMBA_INTERNAL":
 515             logger.info("You have switched to using %s as your dns backend,"
 516                     " but you still have samba starting looking for a"
 517                     " BIND backend. Please remove the -dns from your"
 518                     " server services line." % opts.dns_backend)