python/samba/drs_utils.py

   1 # DRS utility code
   2 #
   3 # Copyright Andrew Tridgell 2010
   4 # Copyright Andrew Bartlett 2017
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 #
  19
  20 from samba.dcerpc import drsuapi, misc, drsblobs
  21 from samba.net import Net
  22 from samba.ndr import ndr_unpack
  23 from samba import dsdb
  24 from samba import werror
  25 from samba import WERRORError
  26 import samba
  27 import ldb
  28 from samba.dcerpc.drsuapi import (DRSUAPI_ATTID_name,
  29                                   DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V8,
  30                                   DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V10)
  31 import re
  32
  33
  34 class drsException(Exception):
  35     """Base element for drs errors"""
  36
  37     def __init__(self, value):
  38         self.value = value
  39
  40     def __str__(self):
  41         return "drsException: " + self.value
  42
  43
  44 def drsuapi_connect(server, lp, creds):
  45     """Make a DRSUAPI connection to the server.
  46
  47     :param server: the name of the server to connect to
  48     :param lp: a samba line parameter object
  49     :param creds: credential used for the connection
  50     :return: A tuple with the drsuapi bind object, the drsuapi handle
  51                 and the supported extensions.
  52     :raise drsException: if the connection fails
  53     """
  54
  55     binding_options = "seal"
  56     if lp.log_level() >= 9:
  57         binding_options += ",print"
  58     binding_string = "ncacn_ip_tcp:%s[%s]" % (server, binding_options)
  59     try:
  60         drsuapiBind = drsuapi.drsuapi(binding_string, lp, creds)
  61         (drsuapiHandle, bindSupportedExtensions) = drs_DsBind(drsuapiBind)
  62     except Exception as e:
  63         raise drsException("DRS connection to %s failed: %s" % (server, e))
  64
  65     return (drsuapiBind, drsuapiHandle, bindSupportedExtensions)
  66
  67
  68 def sendDsReplicaSync(drsuapiBind, drsuapi_handle, source_dsa_guid,
  69                       naming_context, req_option):
  70     """Send DS replica sync request.
  71
  72     :param drsuapiBind: a drsuapi Bind object
  73     :param drsuapi_handle: a drsuapi handle on the drsuapi connection
  74     :param source_dsa_guid: the guid of the source dsa for the replication
  75     :param naming_context: the DN of the naming context to replicate
  76     :param req_options: replication options for the DsReplicaSync call
  77     :raise drsException: if any error occur while sending and receiving the
  78         reply for the dsReplicaSync
  79     """
  80
  81     nc = drsuapi.DsReplicaObjectIdentifier()
  82     nc.dn = naming_context
  83
  84     req1 = drsuapi.DsReplicaSyncRequest1()
  85     req1.naming_context = nc
  86     req1.options = req_option
  87     req1.source_dsa_guid = misc.GUID(source_dsa_guid)
  88
  89     try:
  90         drsuapiBind.DsReplicaSync(drsuapi_handle, 1, req1)
  91     except Exception as estr:
  92         raise drsException("DsReplicaSync failed %s" % estr)
  93
  94
  95 def sendRemoveDsServer(drsuapiBind, drsuapi_handle, server_dsa_dn, domain):
  96     """Send RemoveDSServer request.
  97
  98     :param drsuapiBind: a drsuapi Bind object
  99     :param drsuapi_handle: a drsuapi handle on the drsuapi connection
 100     :param server_dsa_dn: a DN object of the server's dsa that we want to
 101         demote
 102     :param domain: a DN object of the server's domain
 103     :raise drsException: if any error occur while sending and receiving the
 104         reply for the DsRemoveDSServer
 105     """
 106
 107     try:
 108         req1 = drsuapi.DsRemoveDSServerRequest1()
 109         req1.server_dn = str(server_dsa_dn)
 110         req1.domain_dn = str(domain)
 111         req1.commit = 1
 112
 113         drsuapiBind.DsRemoveDSServer(drsuapi_handle, 1, req1)
 114     except Exception as estr:
 115         raise drsException("DsRemoveDSServer failed %s" % estr)
 116
 117
 118 def drs_DsBind(drs):
 119     '''make a DsBind call, returning the binding handle'''
 120     bind_info = drsuapi.DsBindInfoCtr()
 121     bind_info.length = 28
 122     bind_info.info = drsuapi.DsBindInfo28()
 123     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_BASE
 124     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ASYNC_REPLICATION
 125     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_REMOVEAPI
 126     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_MOVEREQ_V2
 127     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHG_COMPRESS
 128     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_DCINFO_V1
 129     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_RESTORE_USN_OPTIMIZATION
 130     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_KCC_EXECUTE
 131     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ADDENTRY_V2
 132     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_LINKED_VALUE_REPLICATION
 133     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_DCINFO_V2
 134     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_INSTANCE_TYPE_NOT_REQ_ON_MOD
 135     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_CRYPTO_BIND
 136     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GET_REPL_INFO
 137     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_STRONG_ENCRYPTION
 138     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_DCINFO_V01
 139     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_TRANSITIVE_MEMBERSHIP
 140     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ADD_SID_HISTORY
 141     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_POST_BETA3
 142     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GET_MEMBERSHIPS2
 143     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V6
 144     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_NONDOMAIN_NCS
 145     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V8
 146     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREPLY_V5
 147     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREPLY_V6
 148     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ADDENTRYREPLY_V3
 149     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREPLY_V7
 150     bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_VERIFY_OBJECT
 151     (info, handle) = drs.DsBind(misc.GUID(drsuapi.DRSUAPI_DS_BIND_GUID), bind_info)
 152
 153     return (handle, info.info.supported_extensions)
 154
 155
 156 def drs_get_rodc_partial_attribute_set(samdb):
 157     '''get a list of attributes for RODC replication'''
 158     partial_attribute_set = drsuapi.DsPartialAttributeSet()
 159     partial_attribute_set.version = 1
 160
 161     attids = []
 162
 163     # the exact list of attids we send is quite critical. Note that
 164     # we do ask for the secret attributes, but set SPECIAL_SECRET_PROCESSING
 165     # to zero them out
 166     schema_dn = samdb.get_schema_basedn()
 167     res = samdb.search(base=schema_dn, scope=ldb.SCOPE_SUBTREE,
 168                        expression="objectClass=attributeSchema",
 169                        attrs=["lDAPDisplayName", "systemFlags",
 170                               "searchFlags"])
 171
 172     for r in res:
 173         ldap_display_name = str(r["lDAPDisplayName"][0])
 174         if "systemFlags" in r:
 175             system_flags      = r["systemFlags"][0]
 176             if (int(system_flags) & (samba.dsdb.DS_FLAG_ATTR_NOT_REPLICATED |
 177                                      samba.dsdb.DS_FLAG_ATTR_IS_CONSTRUCTED)):
 178                 continue
 179         if "searchFlags" in r:
 180             search_flags = r["searchFlags"][0]
 181             if (int(search_flags) & samba.dsdb.SEARCH_FLAG_RODC_ATTRIBUTE):
 182                 continue
 183         attid = samdb.get_attid_from_lDAPDisplayName(ldap_display_name)
 184         attids.append(int(attid))
 185
 186     # the attids do need to be sorted, or windows doesn't return
 187     # all the attributes we need
 188     attids.sort()
 189     partial_attribute_set.attids         = attids
 190     partial_attribute_set.num_attids = len(attids)
 191     return partial_attribute_set
 192
 193
 194 def drs_copy_highwater_mark(hwm, new_hwm):
 195     """
 196     Copies the highwater mark by value, rather than by object reference. (This
 197     avoids lingering talloc references to old GetNCChanges reply messages).
 198     """
 199     hwm.tmp_highest_usn = new_hwm.tmp_highest_usn
 200     hwm.reserved_usn = new_hwm.reserved_usn
 201     hwm.highest_usn = new_hwm.highest_usn
 202
 203
 204 class drs_Replicate(object):
 205     '''DRS replication calls'''
 206
 207     def __init__(self, binding_string, lp, creds, samdb, invocation_id):
 208         self.drs = drsuapi.drsuapi(binding_string, lp, creds)
 209         (self.drs_handle, self.supports_ext) = drs_DsBind(self.drs)
 210         self.net = Net(creds=creds, lp=lp)
 211         self.samdb = samdb
 212         if not isinstance(invocation_id, misc.GUID):
 213             raise RuntimeError("Must supply GUID for invocation_id")
 214         if invocation_id == misc.GUID("00000000-0000-0000-0000-000000000000"):
 215             raise RuntimeError("Must not set GUID 00000000-0000-0000-0000-000000000000 as invocation_id")
 216         self.replication_state = self.net.replicate_init(self.samdb, lp, self.drs, invocation_id)
 217         self.more_flags = 0
 218
 219     def _should_retry_with_get_tgt(self, error_code, req):
 220
 221         # If the error indicates we fail to resolve a target object for a
 222         # linked attribute, then we should retry the request with GET_TGT
 223         # (if we support it and haven't already tried that)
 224         supports_ext = self.supports_ext
 225
 226         # TODO fix up the below line when we next update werror_err_table.txt
 227         # and pull in the new error-code
 228         # return (error_code == werror.WERR_DS_DRA_RECYCLED_TARGET and
 229         return (error_code == 0x21bf and
 230                 supports_ext & DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V10 and
 231                 (req.more_flags & drsuapi.DRSUAPI_DRS_GET_TGT) == 0)
 232
 233     def process_chunk(self, level, ctr, schema, req_level, req, first_chunk):
 234         '''Processes a single chunk of received replication data'''
 235         # pass the replication into the py_net.c python bindings for processing
 236         self.net.replicate_chunk(self.replication_state, level, ctr,
 237                                  schema=schema, req_level=req_level, req=req)
 238
 239     def replicate(self, dn, source_dsa_invocation_id, destination_dsa_guid,
 240                   schema=False, exop=drsuapi.DRSUAPI_EXOP_NONE, rodc=False,
 241                   replica_flags=None, full_sync=True, sync_forced=False, more_flags=0):
 242         '''replicate a single DN'''
 243
 244         # setup for a GetNCChanges call
 245         if self.supports_ext & DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V10:
 246             req = drsuapi.DsGetNCChangesRequest10()
 247             req.more_flags = (more_flags | self.more_flags)
 248             req_level = 10
 249         else:
 250             req_level = 8
 251             req = drsuapi.DsGetNCChangesRequest8()
 252
 253         req.destination_dsa_guid = destination_dsa_guid
 254         req.source_dsa_invocation_id = source_dsa_invocation_id
 255         req.naming_context = drsuapi.DsReplicaObjectIdentifier()
 256         req.naming_context.dn = dn
 257
 258         # Default to a full replication if we don't find an upToDatenessVector
 259         udv = None
 260         hwm = drsuapi.DsReplicaHighWaterMark()
 261         hwm.tmp_highest_usn = 0
 262         hwm.reserved_usn = 0
 263         hwm.highest_usn = 0
 264
 265         if not full_sync:
 266             res = self.samdb.search(base=dn, scope=ldb.SCOPE_BASE,
 267                                     attrs=["repsFrom"])
 268             if "repsFrom" in res[0]:
 269                 for reps_from_packed in res[0]["repsFrom"]:
 270                     reps_from_obj = ndr_unpack(drsblobs.repsFromToBlob, reps_from_packed)
 271                     if reps_from_obj.ctr.source_dsa_invocation_id == source_dsa_invocation_id:
 272                         hwm = reps_from_obj.ctr.highwatermark
 273
 274             udv = drsuapi.DsReplicaCursorCtrEx()
 275             udv.version = 1
 276             udv.reserved1 = 0
 277             udv.reserved2 = 0
 278
 279             cursors_v1 = []
 280             cursors_v2 = dsdb._dsdb_load_udv_v2(self.samdb,
 281                                                 self.samdb.get_default_basedn())
 282             for cursor_v2 in cursors_v2:
 283                 cursor_v1 = drsuapi.DsReplicaCursor()
 284                 cursor_v1.source_dsa_invocation_id = cursor_v2.source_dsa_invocation_id
 285                 cursor_v1.highest_usn = cursor_v2.highest_usn
 286                 cursors_v1.append(cursor_v1)
 287
 288             udv.cursors = cursors_v1
 289             udv.count = len(cursors_v1)
 290
 291         req.highwatermark = hwm
 292         req.uptodateness_vector = udv
 293
 294         if replica_flags is not None:
 295             req.replica_flags = replica_flags
 296         elif exop == drsuapi.DRSUAPI_EXOP_REPL_SECRET:
 297             req.replica_flags = 0
 298         else:
 299             req.replica_flags = (drsuapi.DRSUAPI_DRS_INIT_SYNC |
 300                                  drsuapi.DRSUAPI_DRS_PER_SYNC |
 301                                  drsuapi.DRSUAPI_DRS_GET_ANC |
 302                                  drsuapi.DRSUAPI_DRS_NEVER_SYNCED |
 303                                  drsuapi.DRSUAPI_DRS_GET_ALL_GROUP_MEMBERSHIP)
 304             if rodc:
 305                 req.replica_flags |= (
 306                      drsuapi.DRSUAPI_DRS_SPECIAL_SECRET_PROCESSING)
 307             else:
 308                 req.replica_flags |= drsuapi.DRSUAPI_DRS_WRIT_REP
 309
 310         if sync_forced:
 311             req.replica_flags |= drsuapi.DRSUAPI_DRS_SYNC_FORCED
 312
 313         req.max_object_count = 402
 314         req.max_ndr_size = 402116
 315         req.extended_op = exop
 316         req.fsmo_info = 0
 317         req.partial_attribute_set = None
 318         req.partial_attribute_set_ex = None
 319         req.mapping_ctr.num_mappings = 0
 320         req.mapping_ctr.mappings = None
 321
 322         if not schema and rodc:
 323             req.partial_attribute_set = drs_get_rodc_partial_attribute_set(self.samdb)
 324
 325         if not self.supports_ext & DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V8:
 326             req_level = 5
 327             req5 = drsuapi.DsGetNCChangesRequest5()
 328             for a in dir(req5):
 329                 if a[0] != '_':
 330                     setattr(req5, a, getattr(req, a))
 331             req = req5
 332
 333         num_objects = 0
 334         num_links = 0
 335         first_chunk = True
 336
 337         while True:
 338             (level, ctr) = self.drs.DsGetNCChanges(self.drs_handle, req_level, req)
 339             if ctr.first_object is None and ctr.object_count != 0:
 340                 raise RuntimeError("DsGetNCChanges: NULL first_object with object_count=%u" % (ctr.object_count))
 341
 342             try:
 343                 self.process_chunk(level, ctr, schema, req_level, req, first_chunk)
 344             except WERRORError as e:
 345                 # Check if retrying with the GET_TGT flag set might resolve this error
 346                 if self._should_retry_with_get_tgt(e.args[0], req):
 347
 348                     print("Missing target object - retrying with DRS_GET_TGT")
 349                     req.more_flags |= drsuapi.DRSUAPI_DRS_GET_TGT
 350
 351                     # try sending the request again (this has the side-effect
 352                     # of causing the DC to restart the replication from scratch)
 353                     first_chunk = True
 354                     continue
 355                 else:
 356                     raise e
 357
 358             first_chunk = False
 359             num_objects += ctr.object_count
 360
 361             # Cope with servers that do not return level 6, so do not return any links
 362             try:
 363                 num_links += ctr.linked_attributes_count
 364             except AttributeError:
 365                 pass
 366
 367             if ctr.more_data == 0:
 368                 break
 369
 370             # update the request's HWM so we get the next chunk
 371             drs_copy_highwater_mark(req.highwatermark, ctr.new_highwatermark)
 372
 373         return (num_objects, num_links)
 374
 375
 376 # Handles the special case of creating a new clone of a DB, while also renaming
 377 # the entire DB's objects on the way through
 378 class drs_ReplicateRenamer(drs_Replicate):
 379     '''Uses DRS replication to rename the entire DB'''
 380
 381     def __init__(self, binding_string, lp, creds, samdb, invocation_id,
 382                  old_base_dn, new_base_dn):
 383         super(drs_ReplicateRenamer, self).__init__(binding_string, lp, creds,
 384                                                    samdb, invocation_id)
 385         self.old_base_dn = old_base_dn
 386         self.new_base_dn = new_base_dn
 387
 388         # because we're renaming the DNs, we know we're going to have trouble
 389         # resolving link targets. Normally we'd get to the end of replication
 390         # only to find we need to retry the whole replication with the GET_TGT
 391         # flag set. Always setting the GET_TGT flag avoids this extra work.
 392         self.more_flags = drsuapi.DRSUAPI_DRS_GET_TGT
 393
 394     def rename_dn(self, dn_str):
 395         '''Uses string substitution to replace the base DN'''
 396         return re.sub('%s$' % self.old_base_dn, self.new_base_dn, dn_str)
 397
 398     def update_name_attr(self, base_obj):
 399         '''Updates the 'name' attribute for the base DN object'''
 400         for attr in base_obj.attribute_ctr.attributes:
 401             if attr.attid == DRSUAPI_ATTID_name:
 402                 base_dn = ldb.Dn(self.samdb, base_obj.identifier.dn)
 403                 new_name = base_dn.get_rdn_value()
 404                 attr.value_ctr.values[0].blob = new_name.encode('utf-16-le')
 405
 406     def rename_top_level_object(self, first_obj):
 407         '''Renames the first/top-level object in a partition'''
 408         old_dn = first_obj.identifier.dn
 409         first_obj.identifier.dn = self.rename_dn(first_obj.identifier.dn)
 410         print("Renaming partition %s --> %s" % (old_dn,
 411                                                 first_obj.identifier.dn))
 412
 413         # we also need to fix up the 'name' attribute for the base DN,
 414         # otherwise the RDNs won't match
 415         if first_obj.identifier.dn == self.new_base_dn:
 416             self.update_name_attr(first_obj)
 417
 418     def process_chunk(self, level, ctr, schema, req_level, req, first_chunk):
 419         '''Processes a single chunk of received replication data'''
 420
 421         # we need to rename the NC in every chunk - this gets used in searches
 422         # when applying the chunk
 423         if ctr.naming_context:
 424             ctr.naming_context.dn = self.rename_dn(ctr.naming_context.dn)
 425
 426         # rename the first object in each partition. This will cause every
 427         # subsequent object in the partiton to be renamed as a side-effect
 428         if first_chunk and ctr.object_count != 0:
 429             self.rename_top_level_object(ctr.first_object.object)
 430
 431         # then do the normal repl processing to apply this chunk to our DB
 432         super(drs_ReplicateRenamer, self).process_chunk(level, ctr, schema,
 433                                                         req_level, req,
 434                                                         first_chunk)