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