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